The Essential Role of Proteoglycans and Glycosaminoglycans in Odontogenesis

Tooth development and regeneration are regulated through a complex signaling network. Previous studies have focused on the exploration of intracellular signaling regulatory networks, but the regulatory roles of extracellular networks have only been revealed recently. Proteoglycans, which are essential components of the extracellular matrix (ECM) and pivotal signaling molecules, are extensively involved in the process of odontogenesis. Proteoglycans are composed of core proteins and covalently attached glycosaminoglycan chains (GAGs). The core proteins exhibit spatiotemporal expression patterns during odontogenesis and are pivotal for dental tissue formation and periodontium development. Knockout of core protein genes Biglycan, Decorin, Perlecan, and Fibromodulin has been shown to result in structural defects in enamel and dentin mineralization. They are also closely involved in the development and homeostasis of periodontium by regulating signaling transduction. As the functional component of proteoglycans, GAGs are negatively charged unbranched polysaccharides that consist of repeating disaccharides with various sulfation groups; they provide binding sites for cytokines and growth factors in regulating various cellular processes. In mice, GAG deficiency in dental epithelium leads to the reinitiation of tooth germ development and the formation of supernumerary incisors. Furthermore, GAGs are critical for the differentiation of dental stem cells. Inhibition of GAGs assembly hinders the differentiation of ameloblasts and odontoblasts. In summary, core proteins and GAGs are expressed distinctly and exert different functions at various stages of odontogenesis. Given their unique contributions in odontogenesis, this review summarizes the roles of proteoglycans and GAGs throughout the process of odontogenesis to provide a comprehensive understanding of tooth development.

[Incidence of postoperative complications in Chinese patients with gastric or colorectal cancer based on a national, multicenter, prospective, cohort study]

Objective: To investigate the incidence of postoperative complications in Chinese patients with gastric or colorectal cancer, and to evaluate the risk factors for postoperative complications. Methods: This was a national, multicenter, prospective, registry-based, cohort study of data obtained from the database of the Prevalence of Abdominal Complications After Gastro- enterological Surgery (PACAGE) study sponsored by the China Gastrointestinal Cancer Surgical Union. The PACAGE database prospectively collected general demographic characteristics, protocols for perioperative treatment, and variables associated with postoperative complications in patients treated for gastric or colorectal cancer in 20 medical centers from December 2018 to December 2020. The patients were grouped according to the presence or absence of postoperative complications. Postoperative complications were categorized and graded in accordance with the expert consensus on postoperative complications in gastrointestinal oncology surgery and Clavien-Dindo grading criteria. The incidence of postoperative complications of different grades are presented as bar charts. Independent risk factors for occurrence of postoperative complications were identified by multifactorial unconditional logistic regression. Results: The study cohort comprised 3926 patients with gastric or colorectal cancer, 657 (16.7%) of whom had a total of 876 postoperative complications. Serious complications (Grade III and above) occurred in 4.0% of patients (156/3926). The rate of Grade V complications was 0.2% (7/3926). The cohort included 2271 patients with gastric cancer with a postoperative complication rate of 18.1% (412/2271) and serious complication rate of 4.7% (106/2271); and 1655 with colorectal cancer, with a postoperative complication rate of 14.8% (245/1655) and serious complication rate of 3.0% (50/1655). The incidences of anastomotic leakage in patients with gastric and colorectal cancer were 3.3% (74/2271) and 3.4% (56/1655), respectively. Abdominal infection was the most frequently occurring complication, accounting for 28.7% (164/572) and 39.5% (120/304) of postoperative complications in patients with gastric and colorectal cancer, respectively. The most frequently occurring grade of postoperative complication was Grade II, accounting for 65.4% (374/572) and 56.6% (172/304) of complications in patients with gastric and colorectal cancers, respectively. Multifactorial analysis identified (1) the following independent risk factors for postoperative complications in patients in the gastric cancer group: preoperative comorbidities (OR=2.54, 95%CI: 1.51-4.28, P<0.001), neoadjuvant therapy (OR=1.42, 95%CI:1.06-1.89, P=0.020), high American Society of Anesthesiologists (ASA) scores (ASA score 2 points:OR=1.60, 95% CI: 1.23-2.07, P<0.001, ASA score ≥3 points:OR=0.43, 95% CI: 0.25-0.73, P=0.002), operative time >180 minutes (OR=1.81, 95% CI: 1.42-2.31, P<0.001), intraoperative bleeding >50 mL (OR=1.29,95%CI: 1.01-1.63, P=0.038), and distal gastrectomy compared with total gastrectomy (OR=0.65,95%CI: 0.51-0.83, P<0.001); and (2) the following independent risk factors for postoperative complications in patients in the colorectal cancer group: female (OR=0.60, 95%CI: 0.44-0.80, P<0.001), preoperative comorbidities (OR=2.73, 95%CI: 1.25-5.99, P=0.030), neoadjuvant therapy (OR=1.83, 95%CI:1.23-2.72, P=0.008), laparoscopic surgery (OR=0.47, 95%CI: 0.30-0.72, P=0.022), and abdominoperineal resection compared with low anterior resection (OR=2.74, 95%CI: 1.71-4.41, P<0.001). Conclusion: Postoperative complications associated with various types of infection were the most frequent complications in patients with gastric or colorectal cancer. Although the risk factors for postoperative complications differed between patients with gastric cancer and those with colorectal cancer, the presence of preoperative comorbidities, administration of neoadjuvant therapy, and extent of surgical resection, were the commonest factors associated with postoperative complications in patients of both categories.

Response-guided neoadjuvant sacituzumab govitecan for localized triple-negative breast cancer: results from the NeoSTAR trial

BACKGROUND

Sacituzumab govitecan (SG), a novel antibody-drug conjugate (ADC) targeting TROP2, is approved for pre-treated metastatic triple-negative breast cancer (mTNBC). We conducted an investigator-initiated clinical trial evaluating neoadjuvant (NA) SG (NCT04230109), and report primary results.

PATIENTS AND METHODS

Participants with early-stage TNBC received NA SG for four cycles. The primary objective was to assess pathological complete response (pCR) rate in breast and lymph nodes (ypT0/isN0) to SG. Secondary objectives included overall response rate (ORR), safety, event-free survival (EFS), and predictive biomarkers. A response-guided approach was utilized, and subsequent systemic therapy decisions were at the discretion of the treating physician.

RESULTS

From July 2020 to August 2021, 50 participants were enrolled (median age = 48.5 years; 13 clinical stage I disease, 26 stage II, 11 stage III). Forty-nine (98%) completed four cycles of SG. Overall, the pCR rate with SG alone was 30% [n = 15, 95% confidence interval (CI) 18% to 45%]. The ORR per RECIST V1.1 after SG alone was 64% (n = 32/50, 95% CI 77% to 98%). Higher Ki-67 and tumor-infiltrating lymphocytes (TILs) were predictive of pCR to SG (P = 0.007 for Ki-67 and 0.002 for TILs), while baseline TROP2 expression was not (P = 0.440). Common adverse events were nausea (82%), fatigue (76%), alopecia (76%), neutropenia (44%), and rash (48%). With a median follow-up time of 18.9 months (95% CI 16.3-21.9 months), the 2-year EFS for all participants was 95%. Among participants with a pCR with SG (n = 15), the 2-year EFS was 100%.

CONCLUSIONS

In the first NA trial with an ADC in localized TNBC, SG demonstrated single-agent efficacy and feasibility of response-guided escalation/de-escalation. Further research on optimal duration of SG as well as NA combination strategies, including immunotherapy, are needed.

Fludarabine Enhances Radiosensitivity by Promoting Ferroptosis in B-Cell Lymphoma

The objective of this study is to investigate the impact of fludarabine, a signal transducer and activator of transcription-1 (STAT1) inhibitor, on the radiosensitivity of B-cell lymphoma (BCL) and to explore the underlying mechanisms. Radiotherapy is one of the primary treatments for BCL, and STAT1 plays a critical role in the transcription of cell proliferation-related genes, which are associated with radiotherapy and ferroptosis. This study aims to determine whether fludarabine can enhance the radiosensitivity of BCL and to elucidate the molecular pathways involved. Various in vitro methodologies, including CCK-8 assays, clonogenic formation assays, immunohistochemistry, immunofluorescence, flow cytometry, qRT-PCR, and Western blot analyses, were employed in B-cell lymphoma cell models to thoroughly investigate the effects of fludarabine on radiosensitivity. Subsequently, the obtained results were further validated through in vivo animal models and by examining human diffuse large B-cell lymphoma (DLBCL) cancer samples. Our findings demonstrate that the combination of fludarabine and irradiation synergistically inhibits cell viability and colony formation, while inducing apoptosis and ferroptosis in B-cell lymphoma cell lines Raji and Su-DHL-10. Moreover, fludarabine was found to enhance the ferroptosis induced by radiation, thereby synergistically impeding the growth of BCL. In vivo experiments confirmed these findings, revealing that the intraperitoneal injection of fludarabine significantly enhanced the inhibitory effects of radiation on Raji cell xenograft models, leading to an increased percentage of ferroptosis compared to models without fludarabine. Additionally, the administration of liproxstatin-1, a ferroptosis inhibitor, attenuated the inhibition of xenograft growth caused by the combination of fludarabine and irradiation. Furthermore, our analysis of clinical data revealed that increased co-expression of STAT1 and GPX4 is associated with poor overall survival in patients with diffuse large B-cell lymphoma. These results highlight the potential of fludarabine to enhance radiosensitivity and ferroptosis induction as a promising therapeutic strategy for BCL. Our results demonstrated that fludarabine promoted radiation-induced BCL death through the ferroptosis pathway. We have identified a previously unrecognized mechanism in the fludarabine and radiation combination, indicating that it is necessary to conduct prospective clinical trials to verify this new treatment regimen in BCL.

[Association of urinary cadmium level with body mass index and body circumferences among older adults over 65 years old in 9 longevity areas of China]

Objective: To investigate the association of urinary cadmium level with body mass index (BMI) and body circumferences among the older adults over 65 years old in 9 longevity areas of China. Methods: Subjects were older adults over 65 years old from the Healthy Aging and Biomarkers Cohort Study (HABCS) between 2017 and 2018 conducted in 9 longevity areas in China. A total of 1 968 older adults were included in this study. Information including socio-demographic characteristics, lifestyles, diet intake, and health status was collected by using questionnaires and physical examinations. Urine samples were collected to detect urinary cadmium and creatinine levels. Body circumferences included waist circumference, hip circumference and calf circumference. Subjects were divided into three groups (low:<0.77 μg/g·creatinine, middle:0.77-1.69 μg/g·creatinine, high:≥1.69 μg/g·creatinine) by tertiles of creatinine-adjusted urinary cadmium concentration. Multiple linear regression models were used to analyze the association of creatinine-adjusted urinary cadmium level with BMI and body circumferences. The dose-response relationship of creatinine-adjusted urinary cadmium concentration with BMI and body circumferences was analyzed by using restrictive cubic splines fitting multiple linear regression model. Results: The mean age of subjects was (83.34±11.14) years old. The median (Q1, Q3) concentration of creatinine-adjusted urinary cadmium was 1.13 (0.63, 2.09) μg/g·creatinine, and the BMI was (22.70±3.82) kg/m2. The mean values of waist circumference, hip circumference, and calf circumference were (85.42±10.68) cm, (92.67±8.90) cm, and (31.08±4.76) cm, respectively. After controlling confounding factors, the results of the multiple linear regression model showed that for each increment of 1 μg/g·creatinine in creatinine-adjusted urinary cadmium, the change of BMI, waist circumference, hip circumference, and calf circumference in the high-level group was -0.28 (-0.37, -0.19) kg/m2, -0.74 (-0.96, -0.52) cm, -0.78 (-0.96, -0.61) cm, and -0.20 (-0.30, -0.11) cm, respectively. The restrictive cubic splines curve showed a negative nonlinear association of creatinine-adjusted urinary cadmium with BMI (Pnonlinear<0.001) and negative linear associations of creatinine-adjusted urinary cadmium with waist circumference (Plinear<0.001), hip circumference (Plinear<0.001), and calf circumference (Plinear<0.001). Conclusion: Urinary cadmium level is significantly associated with decreased BMI, waist circumference, hip circumference and calf circumference among older adults over 65 years old in 9 longevity areas of China.

Toripalimab plus axitinib versus sunitinib as first-line treatment for advanced renal cell carcinoma: RENOTORCH, a randomized, open-label, phase III study

BACKGROUND

Immune checkpoint inhibitors in combination with tyrosine kinase inhibitors are standard treatments for advanced clear cell renal cell carcinoma (RCC). This phase III RENOTORCH study compared the efficacy and safety of toripalimab plus axitinib versus sunitinib for the first-line treatment of patients with intermediate-/poor-risk advanced RCC.

PATIENTS AND METHODS

Patients with intermediate-/poor-risk unresectable or metastatic RCC were randomized in a ratio of 1 : 1 to receive toripalimab (240 mg intravenously once every 3 weeks) plus axitinib (5 mg orally twice daily) or sunitinib [50 mg orally once daily for 4 weeks (6-week cycle) or 2 weeks (3-week cycle)]. The primary endpoint was progression-free survival (PFS) assessed by an independent review committee (IRC). The secondary endpoints were investigator-assessed PFS, overall response rate (ORR), overall survival (OS), and safety.

RESULTS

A total of 421 patients were randomized to receive toripalimab plus axitinib (n = 210) or sunitinib (n = 211). With a median follow-up of 14.6 months, toripalimab plus axitinib significantly reduced the risk of disease progression or death by 35% compared with sunitinib as assessed by an IRC [hazard ratio (HR) 0.65, 95% confidence interval (CI) 0.49-0.86; P = 0.0028]. The median PFS was 18.0 months in the toripalimab-axitinib group, whereas it was 9.8 months in the sunitinib group. The IRC-assessed ORR was significantly higher in the toripalimab-axitinib group compared with the sunitinib group (56.7% versus 30.8%; P < 0.0001). An OS trend favoring toripalimab plus axitinib was also observed (HR 0.61, 95% CI 0.40-0.92). Treatment-related grade ≥3 adverse events occurred in 61.5% of patients in the toripalimab-axitinib group and 58.6% of patients in the sunitinib group.

CONCLUSION

In patients with previously untreated intermediate-/poor-risk advanced RCC, toripalimab plus axitinib provided significantly longer PFS and higher ORR than sunitinib and had a manageable safety profile TRIAL REGISTRATION: ClinicalTrials.gov NCT04394975.

AI's Role in Improving Social Connection and Oral Health for Older Adults: A Synergistic Approach

KNOWLEDGE TRANSFER STATEMENT

This study explored how artificial intelligence (AI) can revolutionize geriatric care by improving oral health and alleviating social disconnection among isolated older adults. The findings can guide clinicians in integrating AI tools into practices, assist policymakers in developing AI-inclusive health policies, and inform patients about the potential benefits of AI in enhancing their health outcomes and social connection.

[Association of sleep duration and physical exercise with dyslipidemia in older adults aged 80 years and over in China]

Objective: To explore the impact of sleep duration, physical exercise, and their interactions on the risk of dyslipidemia in older adults aged ≥80 (the oldest old) in China. Methods: The study subjects were the oldest old from four rounds of Healthy Aging and Biomarkers Cohort Study (2008-2009, 2011-2012, 2014 and 2017-2018). The information about their demographic characteristics, lifestyles, physical examination results and others were collected, and fasting venous blood samples were collected from them for blood lipid testing. Competing risk model was used to analyze the causal associations of sleep duration and physical exercise with the risk for dyslipidemia. Restricted cubic spline (RCS) function was used to explore the dose-response relationship between sleep duration and the risk for dyslipidemia. Additive and multiplicative interaction model were used to explore the interaction of sleep duration and physical exercise on the risk for dyslipidemia. Results: The average age of 1 809 subjects was (93.1±7.7) years, 65.1% of them were women. The average sleep duration of the subjects was (8.0±2.5) hours/day, 28.1% of them had sleep duration for less than 7 hours/day, and 27.2% had sleep for duration more than 9 hours/day at baseline survey. During the 9-year cumulative follow-up of 6 150.6 person years (follow-up of average 3.4 years for one person), there were 304 new cases of dyslipidemia, with an incidence density of 4 942.6/100 000 person years. The results of competitive risk model analysis showed that compared with those who slept for 7-9 hours/day, the risk for dyslipidemia in oldest old with sleep duration >9 hours/day increased by 22% (HR=1.22, 95%CI: 1.07-1.39). Compared with the oldest old having no physical exercise, the risk for dyslipidemia in the oldest old having physical exercise decreased by 33% (HR=0.67, 95%CI: 0.57-0.78). The RCS function showed a linear positive dose-response relationship between sleep duration and the risk for hyperlipidemia. The interaction analysis showed that physical exercise and sleep duration had an antagonistic effect on the risk for hyperlipidemia. Conclusion: Physical exercise could reduce the adverse effects of prolonged sleep on blood lipids in the oldest old.

Effect of modified gastrointestinal decompression under abdominal CT in patients with intestinal obstruction

INTRODUCTION

We aimed to evaluate the effect of continuous quality improvement on modified gastrointestinal decompression under abdominal computed tomography (CT) in patients with intestinal obstruction.

METHODS

The CT images of 74 patients with intestinal obstruction who underwent gastrointestinal decompression in our hospital from 1 January 2018 to 31 December 2019 were analysed retrospectively (Control group). Factors influencing unsatisfactory decompression effects were analysed, and corresponding improvement measures were formulated and implemented. A total of 77 patients from 1 January 2020 to 31 March 2022 were enrolled prospectively (Study group). The position of the nasogastric tube end, the amount of gastric drainage within 24h and the degree of abdominal distension relief were compared before and after the improvement.

RESULTS

After implementation of continuous quality improvement, the proportion of the end of the nasogastric tube reaching the antrum, the amount of gastric fluid drainage within 24h and the degree of abdominal distension relief were better than those before improvement (p<0.001, respectively). The execution rate and accuracy rate of CT interpretations by nurses reached 100% and 82%, respectively.

CONCLUSIONS

Modified gastrointestinal decompression based on abdominal CT scans can increase the success of gastrointestinal decompression and effectively reduce the discomfort of patients.

Geroscience: Aging and Oral Health Research

Research in aging has significantly advanced; scientists are now able to identify interventions that slow the biologic aging processes (i.e., the "hallmarks of aging"), thus delaying the onset and progression of multiple diseases, including oral conditions. Presentations given during the 3-part session "Geroscience: Aging and Oral Health Research," held during the 2023 American Association for Dental, Oral, and Craniofacial Research meeting, are summarized in this publication. Speakers' topics spanned the translational research spectrum. Session 1 provided an overview of the geroscience and health span (disease-free and functional health throughout life) concepts. The common molecular mechanisms between oral cancer and aging were discussed, and research was presented that showed periodontal microflora as a potential factor in Alzheimer's disease progression. Session 2 focused on behavioral and social science aspects of aging and their oral health significance. The keynote provided evidence that loneliness and isolation can have major health effects. These social conditions, along with poor oral health, tooth loss, and cognitive decline, could potentially affect healthy eating ability and systemic health in older adults. Research could help elucidate the directions and pathways connecting these seemingly disparate conditions. Session 3 focused on the delivery of oral care in different settings and the many barriers to access care faced by older adults. Research is needed to identify and implement effective technology and strategies to improve access to dental care, including new delivery and financing mechanisms, workforce models, interprofessional provider education and practice, and use of big data from medical-dental integration of electronic health records. Research to improve the "oral health span," reduce oral health disparities, and increase health equity must be tackled at all levels from biologic pathways to social determinants of health and health policies.

Oncologic Outcomes and Safety after Spinal Re-Irradiation with Stereotactic Body Radiation Therapy

PURPOSE/OBJECTIVE(S)

Management of spinal metastases that fail radiation therapy is a challenge, presenting a fine balance between the risk of pain and neurologic deficits if the tumor is not controlled and the increased risks associated with exceeding the tolerance of the spinal cord and other adjacent critical structures. Data regarding SBRT in the re-irradiation setting is limited. The purpose of this study was to report oncologic outcomes and toxicities for patients that received re-irradiation using SBRT.

MATERIALS/METHODS

Patients treated with spine SBRT for re-irradiation at a target which overlapped or abutted a previous conventional RT or SBRT field at a single institution between 2010 and 2021 were retrospectively reviewed. The cumulative constraint to the neural avoidance structures were a BED3 ≤75 Gy (above the conus) or ≤106 Gy (below the conus) accounting for 25% repair at 6 months and 50% repair at 1 year following the first course of RT. Radiographic local recurrence was defined as progressive disease on CT and/or MRI in the treatment volume or at the margin of the treatment field compared with imaging studies before SBRT. Cumulative incidence of local recurrence was reported with death as a competing event, and overall survival was estimated with Kaplan-Meier. Toxicity grades were determined according to NCI CTCAE version 4.0.

RESULTS

Ninety patients (225 vertebrae) with a median age of 56.5 years (range: 27-84 years) were included in the analyses. The most common histologies were NSCLC (17.7%), kidney (15.6%), prostate (14.4%), and breast (7.8%). The majority (51.1%) of metastases were in the T-spine, while 31.1% were in the L-spine and 13.3% in the C-spine. The median prescription dose was 27 Gy (range: 14-40 Gy) in a median of 3 fractions (range: 1-5). The median prescription isodose line was 59% (range: 48%-97%). The median time to re-irradiation with SBRT was 14 months (range: 1-89 months), and the most common prior spinal radiation dose was 30 Gy (range: 8-50 Gy) in a median of 5 fractions (range: 1-15). The median maximal BED3 of the spinal cord from prior radiation and re-irradiation were 52.6 Gy and 31.8 Gy, respectively. The median follow-up was 8.7 months (range: 0.4-43.9 months). The 6-month, 1-year, and 2-year local control rates were 88.9%, 83.4%, and 78.9%, respectively. Only 6.7% of patients underwent salvage surgery, at a median of 9 months after SBRT. The median overall survival was 14.0 months, and overall survival was 54.4% at 1 year and 27.8% at 2 years post-SBRT. All toxicities were grade < 2 and no patients developed spinal cord myelopathy.

CONCLUSION

These data suggest excellent local control and low toxicity following SBRT for re-irradiation of spinal metastases. Future prospective and multi-institutional studies are needed to explore the optimal dose fractionation regimen and cumulative normal tissue constraints to maximize local control and minimize toxicity.

Standard Therapy vs. Individualized Therapy in Elderly Locally Advanced Nasopharyngeal Carcinoma: A Real-World Study

PURPOSE/OBJECTIVE(S)

Concurrent chemoradiotherapy (CRT) with/without induction chemotherapy has been the standard therapy (ST) for locally advanced nasopharyngeal carcinoma (LA-NPC). However, most patients supporting these clinical trials were younger than 65 years of age. For the toxicity of CRT and the poor tolerance of elderly patients, it is still controversial whether ST could bring the most promising survival benefits for elderly NPC compared with individualized therapy (IT). Thus, in this real-world study we compared the survival and safety of ST with IT in elderly LA-NPC to explore an effective and tolerable treatment strategy for elderly LA-NPC.

MATERIALS/METHODS

A total of 109 newly diagnosed elderly LA-NPC (>65 years old) from Jan. 2013-Jul. 2020 were retrospectively enrolled and divided into the ST group and IT group according to the original treatment tendency. ST refers to CRT with/without induction chemotherapy. IT group included patients not suitable for CRT and were given individualized treatment fully discussed by at least two oncologists from our head and neck team. A 1:1 propensity score matching (PSM) generated a matched cohort of ST and IT. The survivals and treatment related toxicities were compared between the two groups.

RESULTS

There were 46 cases in the ST group and 63 cases in the IT group. The 5-year overall survival (OS) rate, cancer-specific survival (CSS) rate, progression- free survival (PFS) rate, local recurrence-free survival (LRFS) rate and distant metastasis-free survival (DMFS) rate were 68.64%, 76.42%, 73.69%, 85.67% and 86.82%, respectively. By 1:1PSM, 35 cases in each group were matched. No significant differences of OS, CSS, PFS, LRFS and DMFS were found between ST and IT groups in the PSM-matched cohorts (P = 0.87, P = 0.79, P = 0.51, P = 0.81 and P = 0.24, respectively). Compared with patients in the ST group, cases received IT were associated with less severe acute toxicities including anemia, leucopenia, neutropenia, and thrombocytopenia.

CONCLUSION

For elderly LA-NPC, IT had similar survivals while less severe toxicities compared with ST, which revolutionarily challenged the role of ST for elderly LA-NPC. In the future, more studies are need to explore a less toxic treatment modality with noninferior efficacy for elderly LA-NPC.

Rates of Radiosurgical Decompression for High Grade Epidural Spinal Disease Due to Solid Tumor Metastases

PURPOSE/OBJECTIVE(S)

A recent phase 2 study reported a significant difference in Bilsky grading of treated lesions before and after SBRT. This study reports rates of epidural downgrading following spine SBRT in a larger cohort of patients with high grade epidural disease.

MATERIALS/METHODS

Patients with high grade epidural disease from solid spinal metastases treated with SBRT from 2009-2021 were retrospectively reviewed. High grade epidural disease was defined as Bilsky grade 1c-3 for lesions above the conus. A modified Bilsky grading was developed and used for lesions below the conus; grade 0 is spinal bone involvement only; grade 1 is epidural involvement without contact of cauda equina; grade 2 is contact of cauda equina with visible cerebrospinal fluid (CSF); grade 3 is compression of cauda equina with no visible CSF. High grade epidural disease below the conus was defined as a modified Bilsky grade 1-3. Patients who received upfront surgery were included in the current study if post-surgical grading met inclusion criteria. The first post-SBRT MRI was compared to the SBRT simulation imaging to evaluate the extent of epidural downgrading. Epidural disease grading pre- and post-SBRT were compared using the Wilcoxon signed-rank test.

RESULTS

A total of 460 vertebral segments from 201 patients were included. The most common histologies were GI (19.3%), breast (16.0%), renal cell carcinoma (13.9%), and prostate (12.6%). Metastases were most often in the T-spine (45.8%), L-spine (34.8%), C-spine (11.8%), and Sacrum (7.6%). Most cases were treated with 3 (37.4%) or 5 (44.5%) fractions with a median prescription dose of 27 Gy or 30 Gy, respectively. 43.3% of cases were treated in the postoperative setting, while 18.5% of cases had prior radiation therapy at the same vertebral level. Median time to first post-SBRT MRI was 3.0 months (IQR 1.8-3.6). Among those with disease above the conus, 98 of the 139 cases (70.5%) had a pre-SBRT Bilsky grade of 2. For those with disease below the conus, 70 of the 99 cases (70.7%) had a pre-SBRT modified Bilsky grade of 1. Epidural downgrading was seen in 32.3% of all cases, 24.3% of postoperative cases, and 25.0% of reirradiation cases. The change in epidural grading was statistically different between pre- and post-SBRT evaluation for all cases (p<0.001), postoperative cases (p<0.001), and reirradiation cases (p = 0.01).

CONCLUSION

We report the largest study to date exploring epidural downgrading following spine SBRT. Although surgery is typically deemed essential for decompression of neural elements, this study suggests that SBRT results in epidural downgrading in as many as one quarter to one third of patients, depending on the clinical scenario.

Stereotactic Body Radiation Therapy for Large Volume Solid Tumor Spinal Metastases Involving Three or More Contiguous Vertebral Levels

PURPOSE/OBJECTIVE(S)

Data for treating 3 or more contiguous vertebral bodies with SBRT is limited. The purpose of this study was to explore oncologic outcomes and toxicity of spine SBRT delivered to large volume solid tumor metastases involving 3 or more contiguous vertebral levels.

MATERIALS/METHODS

Patients treated with spine SBRT for vertebral metastases involving 3 or more contiguous levels between 2009 and 2021 were retrospectively reviewed. Data on demographics, dosimetry, toxicity, and outcomes were collected. Radiographic local failure was defined as progressive disease on CT and/or MRI in the treatment volume compared to the pre-SBRT baseline. Local control (LC) and overall survival (OS) were calculated from end of SBRT using the Kaplan-Meier and log-rank test.

RESULTS

A total of 141 patients were included with a median follow-up of 9.7 months. The majority of patients had either 3 (74%) or 4 (16%) involved contiguous vertebral levels. Twenty-two percent, 57%, 14%, and 7% of treated lesion began in the cervical, thoracic, lumbar, and sacral vertebral levels, respectively. The most common primary sites were NSCLC (15.6%), kidney (14.9%), and breast (13.5%). Thirty-two percent of patients had prior external beam radiation to the same vertebral level, 63% had prior surgery, and 43% had prior vertebral fracture. Paraspinal extension was identified in 26% at time of SBRT. Median pre-SBRT Bilsky grade was 2 (range 0-3). The median total prescription dose was 27 Gy (range: 12-43 Gy) with the most common dose (Gy)/fractionation schedules of 27/5 (32%), 30/5 (25%), and 25/5 (18%). The median Dmax was 4727 cGy (range 2070-7857) with a median prescription isodose of 58% (range 48-97). The median OS was 12.4 months (95% CI 9.6-15.3). 1- and 2- year OS were 51% and 35%, respectively. Local progression occurred across all histologies, most commonly in colon and NSCLC (16.7%). 1- and 2-year LC were 70% and 57%, respectively. In the radiation-naïve cohort, 1- and 2-year LC were 75% and 63%, respectively and 52% and 34% in the prior radiation group with no statistically significant difference in time to local progression (p = 0.075). There was no statistically significant difference in LC when comparing 3 versus 4 or more contiguous lesions (p = 0.66). Forty percent of patients that progressed underwent salvage treatment (58% surgery, 33% SBRT, 8% systemic therapy). Post-SBRT vertebral compression fracture rate was 11.6%.

CONCLUSION

We present the largest series to date of patients treated with SBRT for large volume spinal metastases involving 3 or more contiguous levels. These data suggest reasonable local control and low toxicity with SBRT; therefore, SBRT should be considered a practical modality to offer this cohort.

[A clinical cohort study of split and whole liver transplantations]

Objective: To investigate the surgical efficacy of split liver transplantation. Methods: Patients who underwent liver transplantation at the Affiliated Hospital of Qingdao University between January 2015 and December 2022 were retrospectively analyzed. They were divided into split liver transplantation group (n=60) and whole liver transplantation group (n=765)according to graft types.In the split liver transplantation group, there were 23 males and 37 females, aged (52.5±10.2) years, and the body mass index was (22.4±3.3) kg/m2. In the whole liver transplantation group, there were 630 males and 135 females, aged (51.2±9.6) years, and body mass index was (24.5±3.7) kg/m2.The basic data of the two groups were matched 1∶1 using the propensity score matching method. The independent sample t test and χ2 test were used to compare the intraoperative and postoperative recovery of the two groups of donors and recipients. The overall survival rate and the graft survival rate of the two groups were analyzed by Kaplan-Meier method and the cumulative survival rate was compared by the Log-rank test. Results: Fifty-one well-matched pairs of data with similar baseline characteristics were obtained. The ratio of graft mass to recipient body weight in the matched split liver transplantation group was (1.78±0.55)%. Operation time(M(IQR))(10.8(1.5)hours vs. 8.0(1.9)hours,U=6.608,P<0.01) and cold ischaemia time(5.4(1.3)hours vs. 4.6(2.2)hours,U=2.825,P=0.005) were significantly longer in the split liver transplantation group than those in the whole liver transplantation group. Intra-operative anhepatic phase(53.0(15.0)minutes vs. 57.0(24.0)minutes,U=1.048,P=0.295),bleeding volume(1 000(1 400)ml vs. 1 200(1 200)ml,U=0.966,P=0.334) and intraoperative instillation of red blood cells(9.0(6.5)U vs. 11.0(11.0)U,U=1.732,P=0.083) were not significantly different between the two groups. However,the split liver transplantation group showed significantly longer postoperative intensive care unit stay(5.0(3.0)days vs. 4.0(4.0)days,U=2.677,P=0.007) and postoperative hospital stay(30.0(15.0)days vs. 26.0(15.0)days,U=2.237,P=0.025) and significantly higher incidence of postoperative complications(56.8%(29/51) vs. 36.6%(19/51),χ2=3.935,P=0.047) than the whole liver transplantation group. Furthermore,levels of alanine transaminase and aspartate aminotransferase were significantly higher on postoperative days 1,4 and 7 in the split liver transplantation group(all P<0.05) than in the whole liver transplantation group;however,there were no significant differences in these levels on postoperative days 14 and 28. The time to restoration of normal liver function in both groups(12.5(13.7)days vs. 9.0(12.5)days,U=1.607,P=0.108) was not statistically significant. Furthermore,the median follow-up time after surgery was 25.6 months in both groups. In postoperative years 1,2,3 and 5, the graft survival rates were 88.1%,80.8%,77.8% and 66.7% in the whole liver transplantation group and 80.3%,70.3%,67.3% and 60.5% in the split liver transplantation group(P=0.171),respectively. The patient survival rates in post-operative years 1,2,3 and 5 were 88.1%,80.8%,77.8% and 66.7% in the whole liver transplantation group and 80.3%,75.9%,70.3% and 63.3% in the split liver transplantation group,respectively(P=0.252). However,the differences of graft survival rates and patient survival rates between the two groups were not significant. Conclusion: Although it affects the early recovery of patients after liver transplantation,split liver transplantation has no effect on long-term survival rates and demonstrates surgical efficacy similar to that of whole liver transplantation.

[Development and validation of a prognostic prediction model for patients with stage Ⅰ to Ⅲ colon cancer incorporating high-risk pathological features]

Objective: To examine a predictive model that incorporating high risk pathological factors for the prognosis of stage Ⅰ to Ⅲ colon cancer. Methods: This study retrospectively collected clinicopathological information and survival outcomes of stage Ⅰ~Ⅲ colon cancer patients who underwent curative surgery in 7 tertiary hospitals in China from January 1, 2016 to December 31, 2017. A total of 1 650 patients were enrolled, aged (M(IQR)) 62 (18) years (range: 14 to 100). There were 963 males and 687 females. The median follow-up period was 51 months. The Cox proportional hazardous regression model was utilized to select high-risk pathological factors, establish the nomogram and scoring system. The Bootstrap resampling method was utilized for internal validation of the model, the concordance index (C-index) was used to assess discrimination and calibration curves were presented to assess model calibration. The Kaplan-Meier method was used to plot survival curves after risk grouping, and Cox regression was used to compare disease-free survival between subgroups. Results: Age (HR=1.020, 95%CI: 1.008 to 1.033, P=0.001), T stage (T3:HR=1.995,95%CI:1.062 to 3.750,P=0.032;T4:HR=4.196, 95%CI: 2.188 to 8.045, P<0.01), N stage (N1: HR=1.834, 95%CI: 1.307 to 2.574, P<0.01; N2: HR=3.970, 95%CI: 2.724 to 5.787, P<0.01) and number of lymph nodes examined (≥36: HR=0.438, 95%CI: 0.242 to 0.790, P=0.006) were independently associated with disease-free survival. The C-index of the scoring model (model 1) based on age, T stage, N stage, and dichotomous variables of the lymph nodes examined (<12 and ≥12) was 0.723, and the C-index of the scoring model (model 2) based on age, T stage, N stage, and multi-categorical variables of the lymph nodes examined (<12, 12 to <24, 24 to <36, and ≥36) was 0.726. A scoring system was established based on age, T stage, N stage, and multi-categorical variables of lymph nodes examined, the 3-year DFS of the low-risk (≤1), middle-risk (2 to 4) and high-risk (≥5) group were 96.3% (n=711), 89.0% (n=626) and 71.4% (n=313), respectively. Statistically significant difference was observed among groups (P<0.01). Conclusions: The number of lymph nodes examined was an independent prognostic factor for disease-free survival after curative surgery in patients with stage Ⅰ to Ⅲ colon cancer. Incorporating the number of lymph nodes examined as a multi-categorical variable into the T and N staging system could improve prognostic predictive validity.

Turbulent burning velocity and thermodiffusive instability of premixed flames

Reported in the paper are results of unsteady three-dimensional direct numerical simulations of laminar and turbulent, lean hydrogen-air, complex-chemistry flames propagating in forced turbulence in a box. To explore the eventual influence of thermodiffusive instability of laminar flames on turbulent burning velocity, (i) a critical length scale Λ_{n} that bounds regimes of unstable and stable laminar combustion is numerically determined by gradually decreasing the width Λ of computational domain until a stable laminar flame is obtained, and (ii) simulations of turbulent flames are performed by varying the width from Λ<Λ_{n} (in this case, the instability is suppressed) to Λ>Λ_{n} (in this case, the instability may grow). Moreover, simulations are performed either using mixture-averaged transport properties (low Lewis number flames) or setting diffusivities of all species equal to heat diffusivity of the mixture (equidiffusive flames), with all other things being equal. Obtained results show a significant increase in turbulent burning velocity U_{T} when the boundary Λ=Λ_{n} is crossed in weak turbulence, but almost equal values of U_{T} are computed at Λ<Λ_{n} and Λ>Λ_{n} in moderately turbulent flames characterized by a Karlovitz number equal to 3.4 or larger. These results imply that thermodiffusive instability of laminar premixed flames substantially affects burning velocity in weak turbulence only, in line with a simple criterion proposed by Chomiak and Lipatnikov (Phys. Rev. E 107, 015102, (2023)10.1103/PhysRevE.107.015102).

[Analysis of influencing factors and clinical value of anterior peritoneal reflection for patients with rectal cancer]

Objectives: To investigate the factors influencing the height of anterior peritoneal reflection (APR) for patients with rectal cancer, and to analyze the relationship between the APR and the lateral lymph node metastasis. Methods: Clinical data of 432 patients with tumor located within and below APR were retrospectively collected from the rectal cancer database at the Department of General Surgery, Peking Union Medical College Hospital from August 2020 to September 2022. Ninty-eight non-rectal cancer patients were also enrolled as a control group. There were 308 males and 124 females in the tumor group, aged (M(IQR)) 62 (16) years (range: 24 to 85 years) and 53 males and 45 females in the control group, aged 60 (22) years (range: 27 to 87 years). The APR height, pelvis, and tumor-related parameters were measured by MRI. A multifactor linear regression model was established to analyze the dependent correlation factors of APR height. These factors of the two groups were matched by propensity score matching and their APR heights were compared after matching. An ordinal Logistic regression model was established to explore the relationship between APR-related parameters and radiographic lateral lymph node metastasis. Results: The APR height of the tumor group was (98.7±14.4) mm (range: 43.3 to 154.0 mm) and the control group was (95.1±12.7) mm (range: 68.0 to 137.9 mm). Multivariable linear regression revealed that the greater the weight (B=0.519, 95%CI: 0.399 to 0.640, P<0.01), the anterior pelvic depth (B=0.109, 95%CI: 0.005 to 0.213, P=0.039) and the smaller the bi-ischial diameter (B=-0.172, 95%CI:-0.294 to -0.049, P=0.006), the higher the APR height. The tumor group had a higher APR height than the control group after propensity score matching ((98.3±14.2) mm vs. (95.1±12.7) mm, t=-1.992, P=0.047). Ordinal Logistic regression indicated that the longer segment of the tumor invade the nonperitoneal rectum was an independent influencing factor of radiographic lateral lymph node metastasis (OR=1.016, 95%CI: 1.002 to 1.030, P=0.021), while the distance between the anal verge and the tumor was not (OR=0.986, 95%CI: 0.972 to 1.000, P=0.058). Conclusions: The higher the weight, the deeper and narrower the pelvis, the higher the APR height. There is a certain relationship between APR and lateral lymph node metastasis on imaging.

LncRNA SATB2-AS1 promotes tumor growth and metastasis and affects the tumor immune microenvironment in osteosarcoma by regulating SATB2

Our previous report has identified a lncRNA SATB2-AS1, which was significantly up-regulated in osteosarcoma tissue and promotes the proliferation of osteosarcoma cells in vitro. However, the mechanisms of SATB2-AS1 regulating the growth and metastasis of osteosarcoma cells in vivo and its role in the prognosis of osteosarcoma patients are still unclear. In this study, the transcriptome sequencing data of 87 patients with osteosarcoma from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database and 7 patients from our clinical center (GZFPH) was used to evaluate the importance of SATB2-AS1 and SATB2 on the prognosis. The effect of SATB2-AS1 on the growth and metastasis of osteosarcoma cells in vivo was verified by a mouse tumor model. The potential mechanisms of SATB2-AS1 regulating SATB2 were further explored by dual-luciferase reporter gene assay, RNA pull-down assay, and bioinformatics analysis. The results suggested that increased co-expression of SATB2-AS1 and SATB2 was significantly associated with poor overall survival (OS) and relapse-free survival (RFS), and was a biomarker for risk stratification in patients with osteosarcoma. Mechanistically, SATB2-AS1 promotes tumor growth and lung metastasis by regulating SATB2 in vivo. SATB2-AS1 directly binds to POU3F1 for mediating SATB2 expression in MNNG/HOS cells. In addition, SATB2-AS1 and SATB2 might be potential immunomodulators for negatively affecting immune cell infiltration by the IL-17 signaling pathway. In summary, SATB2-AS1 promoted tumor cell growth and lung metastasis by activating SATB2, thereby associated with poor prognosis in patients with osteosarcoma, which indicated that SATB2-AS1 and SATB2 might be novel biomarkers for risk stratification and promising therapeutic targets for osteosarcoma.

Aging and Oral Health: Biological and Sociobehavioral Perspectives

As the life expectancy and growth of the aging population increase globally, efforts to promote healthy longevity become more important. Holistic policy guidelines and actions have been designed to advocate and fortify healthy aging at multiple levels. Oral health, a fundamental contributor of overall health and well-being, forms a core part of the noncommunicable disease agenda within the sustainable development goals set by the World Health Organization. Aging significantly heightens the risk of myriad oral disorders and other noncommunicable diseases. As of 2019, oral disorders accounted for 8.9 million disability-adjusted life-years in individuals older than 60 y. In addition to the development of multidisciplinary aging-friendly policies to promote healthy aging, basic biology and translational research has been encouraged that focuses on deciphering the underlying mechanisms involved in age-related physical and cognitive decline or dysregulation of oral tissues. Given the relevance of oral health aging as a critical component of the One Health Initiative, this special issue encompasses a collection of articles dedicated to recent advances in the behavioral and social implications of age-related oral diseases and tooth loss on several aspects of the quality of life of adults as they age. Furthermore, it includes articles detailing molecular mechanisms associated with cellular aging and their implications for oral tissue health, periodontal disease severity, and the regenerative potential of stem cells.

[Notch signaling pathway inhibitor DAPT improves alcohol-induced neuronal differentiation impairment in zebrafish]

OBJECTIVE

To explore the role of the Notch signaling pathway in regulating neuronal differentiation and sensorimotor ability in a zebrafish model of fetal alcohol spectrum disorder.

METHODS

Zebrafish embryos treated with DMSO or 50 μmol/L DAPT (a Notch signaling pathway inhibitor) were examined for mortality rate, hatching rate, malformation rate, and body length at 15 days post fertilization (dpf). The mRNA expression levels of sox2, neurogenin1 and huc in the treated zebrafish embryos were detected using in situ hybridization and qRT-PCR, and their behavioral responses to strong light and vibration stimulation were observed. The zebrafish embryos were then exposed to DMSO, 1.5% ethanol, DAPT, or both ethanol and DAPT, and the changes in mRNA expression levels of sox2, neurogenin1, huc, and the Notch signaling pathway genes as well as behavioral responses were evaluated.

RESULTS

Exposure to 50 μmol/L DAPT significantly increased the mortality rate of 1 dpf zebrafish embryos (P < 0.01), decreased the hatching rate of 2 dpf embryos (P < 0.01), increased the malformation rate of 3 dpf embryos (P < 0.001), and reduced the body length of 15 dpf embryos (P < 0.05). DAPT treatment significantly downregulated sox2 mRNA expression (P < 0.01) and increased neurogenin1 (P < 0.05) and huc (P < 0.01) mRNA expressions in zebrafish embryos. The zebrafish with DAPT treatment exhibited significantly shortened movement distance (P < 0.001) and lowered movement speed (P < 0.05) in response to all the stimulation conditions. Compared with treatment with 1.5% ethanol alone, which obviously upregulated notch1a, her8a and NICD mRNA expressions in zebrafish embryos (P < 0.05), the combined treatment with ethanol and DAPT significantly increased neurogenin1 and huc mRNA expression, decreased sox2 mRNA expression (P < 0.01), and increased the moving distance and moving speed of zebrafish embryos in response to strong light stimulation (P < 0.05).

CONCLUSION

Ethanol exposure causes upregulation of the Notch signaling pathway and impairs neuronal differentiation and sensorimotor ability of zebrafish embryos, and these detrimental effects can be lessened by inhibiting the Notch signaling pathway.

[Distribution characteristics of body mass index among Chinese oldest-old aged 80 years and above]

Objective: To investigate body mass index (BMI) level, identify the main type of nutritional problem, and describe the population distribution characteristics of BMI among Chinese people aged 80 years or above. Methods: The data of 9 481 oldest-old individuals were obtained from the 2017-2018 Chinese Longitudinal Healthy Longevity Survey. The Lambda-Mu-Sigma method, weighted estimates of BMI, and comparisons by BMI quintiles were used to describe the BMI level and distribution characteristics among the oldest-old. Results: The average age of the participants was (91.9±7.7) years, with P₅₀ of the weighted BMI at 21.9 (95%CI: 21.8-22.0) kg/m². The result of BMI level showed a decreasing trend with age, with a rapid decline before age 100, and then the trend became slower. There are about 30% of the oldest-old classified as undernutrition, but the prevalence of overnutrition is only about 10%. The population distribution characteristics by BMI quintiles showed the oldest-old with lower BMI levels were likely to have the following characteristics: sociodemographically, to be older, female, ethnic minority, unmarried/divorced/widowed, rural residents, illiterate, with inadequate living expenses, located in Central, South, or Southwest China; regarding lifestyles, lower BMI levels were observed for participants who were smoking, not exercising, lack of leisure activities, or with poor dietary diversity; considering functional status, participants with lower BMI levels were those who have poor chewing ability, disability in activities of daily living, cognitive impairment, hearing loss, visual impairment, or poor self-rated health status. The oldest-old with higher BMI levels were likely to have heart disease, hypertension, cerebrovascular disease, and diabetes. Conclusions: The overall BMI level was low among the Chinese oldest-old and it showed a downward trend with age. Currently, the main nutritional problem among the Chinese oldest-old was undernutrition rather than overweight or obesity. Management of healthy lifestyles, functional status, and diseases would be helpful to reduce the risk of undernutrition among the oldest-old.

[Association between cognitive impairment and main metals among oldest old aged 80 years and over in China]

Objective: To identify the main metals involved in cognitive impairment in the Chinese oldest old, and explore the association between these metal exposures and cognitive impairment. Methods: A cross-sectional study was conducted on 1 568 participants aged 80 years and older from Healthy Aging and Biomarkers Cohort Study (2017 to 2018). Fasting venous blood was collected to measure the levels of nine metals (selenium, lead, cadmium, arsenic, antimony, chromium, manganese, mercury, and nickel). The cognitive function of these participants was evaluated by using the Chinese version of the Mini-Mental State Examination (CMMSE). The random forest (RF) was applied to independently identify the main metals that affected cognitive impairment. The multivariate logistic regression model and restricted cubic splines (RCS) model were used to further verify the association of the main metals with cognitive impairment. Results: The age of 1 568 study subjects was (91.8±7.6) years old, including 912 females (58.2%) and 465 individuals (29.7%) with cognitive function impairment. Based on the RF model (the out-of-bag error rate was 22.9%), the importance ranking of variables was conducted and the feature screening of five times ten-fold cross-validation was carried out. It was found that selenium was the metal that affected cognitive function impairment, and the other eight metals were not included in the model. After adjusting for covariates, the multivariate logistic regression model showed that with every increase of 10 μg/L of blood selenium levels, the risk of cognitive impairment decreased (OR=0.921, 95%CI: 0.889-0.954). Compared with the lowest quartile(Q₁) of blood selenium, the ORs (95%CI) of Q₃ and Q₄ blood selenium were 0.452 (0.304-0.669) and 0.419 (0.281-0.622) respectively. The RCS showed a linear dose-response relationship between blood selenium and cognitive impairment (P_nonlinear>0.05). Conclusion: Blood selenium is negatively associated with cognitive impairment in the Chinese oldest old.

Factors of Dental Care Utilization in Foreign-Born Older Chinese Americans

Good oral health is essential for healthy aging. Regular dental care utilization is instrumental to good oral health. Older immigrants tend to experience poorer oral health and less dental care use as compared with their native-born counterparts in the host country. Older immigrants are particularly vulnerable to interrupted or lost social ties and acculturation challenges after immigration to a new country. This study examined whether and to what extent social relations, acculturation, and perceived oral health needs are associated with dental care utilization in foreign-born older Chinese Americans. Data came from the Population Study of Chinese Elderly in Chicago, which were collected between 2017 and 2019 (N = 3,000). Dental care utilization was dichotomized into "yes" versus "no" in the past 2 y. Social relations were measured by positive and negative relations with spouse, family, and friends. Acculturation was measured by length of stay, behavioral acculturation, and residence in Chinatown. Perceived oral health needs were measured by the presence of problems related to teeth, gums, or bleeding. As guided by the Andersen model, separate logistic regression models were used to investigate factors of dental care utilization. An overall 23.1% reported dental care utilization. Individuals with no negative relations with spouse, family, and friends were 31%, 36%, and 38% less likely to visit a dentist, respectively. Individuals with higher levels of behavioral acculturation were 4% more likely to visit a dentist; individuals living in Chinatown were 45% less likely; and individuals with perceived oral health needs were 2.5 times more likely. Findings illustrate the importance of understanding social relations, immigration-related factors, and perceived oral health needs in dental care utilization in older immigrants.

[Association of plasma vitamin B12 level with plasma uric acid level among the elderly over 65 years old in 9 longevity areas of China]

Objective: To investigate the association of plasma vitamin B₁₂ level with plasma uric acid level among the elderly over 65 in 9 longevity areas of China. Methods: The elderly over 65 years old with complete information on plasma vitamin B₁₂ and plasma uric acid from Healthy Aging and Biomarkers Cohort Study (2017 to 2018) were recruited in this study. Information on socio-demographic characteristics, life styles, diet intake, and health status were collected by questionnaire and physical examination; and fasting venous blood was collected to detect the levels of plasma vitamin B₁₂, uric acid and other indicators. Multiple linear regression models were used to analyze the association of plasma vitamin B₁₂ level per interquartile range increase with plasma uric acid level. The association trend of plasma vitamin B₁₂ level with plasma uric acid level was described by restrictive cubic splines fitting multiple linear regression model. Multiple logistic regression models were used to analyze the association of plasma vitamin B₁₂ level stratified by quartiles with hyperuricemia. Results: A total of 2 471 participants were finally included in the study, the age was (84.88±19.76) years old, of which 1 291 (52.25%) were female. The M (Q₁, Q₃) level of plasma vitamin B₁₂ was 294 (203, 440) pg/ml and the plasma uric acid level was (341.01±90.46) μmol/L. A total of 422 participants (17.08%) were defined with hyperuricemia. The results of multiple linear regression model showed that there was a positive association of plasma vitamin B₁₂ level with plasma uric acid level after adjustment for covariates (P<0.05). An IQR increase in plasma vitamin B₁₂ (237 pg/ml) was associated with a 6.36 (95%CI: 2.00-10.72) μmol/L increase in the plasma uric acid level. The restrictive cubic splines curve showed a positive linear association of log-transformed plasma vitamin B₁₂ with uric acid level (P<0.001). Conclusion: There is a positive association of plasma vitamin B₁₂ level with plasma uric acid level among the elderly over 65 years old in 9 longevity areas of China.

[Association of greenness, nitrogen dioxide with the prevalence of hypertension among the elderly over 65 years old in China]

Objective: To investigate the association of mixed exposure to greenness and nitrogen dioxide(NO₂) and hypertension among the older adults aged 65 years and over in China. Methods: The study subjects were from the Chinese Longitudinal Healthy Longevity Survey from 2017 to 2018. A total of 15 423 older adults aged 65 years and over meeting the criteria were finally included in the study. A questionnaire survey was used to collect information on demographic characteristics, lifestyle habits and self-reported prevalence of hypertension. Blood pressure values were obtained through physical examination. The level of normalized difference vegetation index(NDVI) was measured by the Medium-resolution Imaging Spectral Radiator(MODIS) of the National Aeronautics and Space Administration(NASA). The concentration of NO₂ was from China's surface air pollutant data set. Meteorological data was from NASA MERRA-2. The exposure to NDVI and NO₂ for each study subject was calculated based on the area within a 1 km radius around their residence. The association between mixed exposure of NDVI and NO₂ as well as their interaction and hypertension in older adults was analyzed by using the multivariate logistic regression model. The restrictive cubic spline(RCS) function was used to explore the exposure-response relationship between greenness and NO₂ and the risk of hypertension in study subjects. Results: The mean age of 15 423 older adults were (85.6±11.6). Women accounted for 56.3%(8 685/15 423) and 55.6%(8 578/15 423) lived in urban areas. The mean time of residence was (60.9±28.5) years. 59.8% of participants were with hypertension. The mean NDVI level was 0.41±0.13, and the mean NO₂ concentration was (32.18±10.36) μg/cm³. The results of multivariate logistic regression analysis showed that NDVI was inversely and linearly associated with the hypertension in older adults, with the OR(95%CI) value of 0.959(0.928-0.992). Compared with the T₁ group of NDVI, the risk of hypertension was lower in the T₃ group, with the OR(95%CI) value of 0.852(0.769-0.944), and the trend test was statistically significant(P<0.05). Compared with the T₁ group of NO₂, the risk of hypertension was higher in the T₂ and T₃ groups, with OR(95%CI) values of 1.160(1.055-1.275) and 1.244(1.111-1.393), and the trend test was statistically significant (P<0.05). The result of the RCS showed that NDVI was inversely and linearly associated with hypertension in older adults. NO₂ was nonlinearly associated with hypertension in older adults. The interaction analysis showed that NDVI and NO₂ had a negative multiplicative interaction on the risk of hypertension, with OR(95%CI) value of 0.995(0.992-0.997). Conclusion: Exposure to greenness and NO₂ are associated with hypertension in older adults.

Neurological complications of COVID-19

Corona Virus Disease 2019 (COVID-19) has caused several pandemic peaks worldwide due to its high variability and infectiousness, and COVID-19 has become a long-standing global public health problem. There is growing evidence that severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) frequently causes multi-organ injuries and more severe neurological manifestations. Therefore, increased awareness of possible neurological complications is beneficial in preventing and mitigating the impact of long-term sequelae and improving the prognostic outcome of critically ill patients with COVID-19. Here, we review the main pathways of SARS-CoV-2 neuroinvasion and the potential mechanisms causing neurological damage. We also discuss in detail neurological complications, aiming to provide cutting-edge basis for subsequent related basic research and clinical studies of diagnosis and treatment.

[Hepatitis B virus down-regulates the expression of inhibin and promotes the proliferation and survival of hepatocellular carcinoma cells]

Objective: To investigate the effect and role of the hepatitis B virus (HBV) on the expression of inhibin (PHB) in the proliferation and survival of hepatocellular carcinoma (HCC) cells. Methods: The expression of PHB in 13 pairs of HBV-infected livers, normal livers and HepG2.2.15 and HepG2 cells was detected by real-time fluorescent quantitative PCR and Western blot. Liver tissues were collected from seven patients with chronic hepatitis B before and after antiviral (tenofovir) treatment, and the expression of PHB was detected by RT-PCR and Western blot. HepG2.2.15 cells were transfected with Pcmv6-AC-GFP-PHB, and control vectors were collected. DNA content was analyzed by flow cytometry. The proliferation level of each cell group was detected using the EdU cell proliferation assay. HepG2.2.15 cells transfected with Pcmv6-AC-GFP-PHB and the control vector were cultured in serum-free medium for 6 days. Apoptosis was measured at the indicated time points using fluorescence-activated cell sorting (FACS)-based Annexin-V/PI double staining. Results: Compared with normal liver tissue, the expression of PHB in HBV-infected liver tissue was down-regulated (P < 0.01). Compared with HepG2 cells, the expression of PHB in HepG2.2.15 cells was significantly decreased (P < 0.01). The expression level of PHB in liver tissue after antiviral treatment (tenofovir) was significantly higher than that before treatment (P < 0.01). Compared with the control vector, the proliferation rate of HepG2.2.15 cells transfected with Pcmv6-AC-GFP-PHB was significantly lower than that of the control vector, and the apoptosis rate of HepG2.2.15 cells transfected with the Pcmv6-AC-GFP-PHB vector was significantly higher than the control vector (P < 0.01). Conclusion: HBV down-regulates the expression of inhibin to promote the proliferation and survival of hepatocellular carcinoma cells.

Diabetes, Edentulism, and Cognitive Decline: A 12-Year Prospective Analysis

Diabetes mellitus (DM) is a recognized risk factor for dementia, and increasing evidence shows that tooth loss is associated with cognitive impairment and dementia. However, the effect of the co-occurrence of DM and edentulism on cognitive decline is understudied. This 12-y cohort study aimed to assess the effect of the co-occurrence of DM and edentulism on cognitive decline and examine whether the effect differs by age group. Data were drawn from the 2006 to 2018 Health and Retirement Study. The study sample included 5,440 older adults aged 65 to 74 y, 3,300 aged 75 to 84 y, and 1,208 aged 85 y or older. Linear mixed-effect regression was employed to model the rates of cognitive decline stratified by age cohorts. Compared with their counterparts with neither DM nor edentulism at baseline, older adults aged 65 to 74 y (β = -1.12; 95% confidence interval [CI], -1.56 to -0.65; P < 0.001) and those aged 75 to 84 y with both conditions (β = -1.35; 95% CI, -2.09 to -0.61; P < 0.001) had a worse cognitive function. For the rate of cognitive decline, compared to those with neither condition from the same age cohort, older adults aged 65 to 74 y with both conditions declined at a higher rate (β = -0.15; 95% CI, -0.20 to -0.10; P < 0.001). Having DM alone led to an accelerated cognitive decline in older adults aged 65 to 74 y (β = -0.09; 95% CI, -0.13 to -0.05; P < 0.001); having edentulism alone led to an accelerated decline in older adults aged 65 to 74 y (β = -0.13; 95% CI, -0.17 to -0.08; P < 0.001) and older adults aged 75 to 84 (β = -0.10; 95% CI, -0.17 to -0.03; P < 0.01). Our study finds the co-occurrence of DM and edentulism led to a worse cognitive function and a faster cognitive decline in older adults aged 65 to 74 y.

Serum CCL28 as a biomarker for diagnosis and evaluation of Sjögren's syndrome

OBJECTIVE

The aim of this study was to explore the significance of serum CCL28 in Sjögren's syndrome (SS) diagnosis and evaluation.

METHOD

The expression of CCL28 mRNA in salivary glands of SS patients from the GEO database was analysed. Serum levels of CCL28 of SS patients, rheumatoid arthritis (RA) patients, systemic lupus erythematosus (SLE) patients, and healthy controls (HCs) were measured by enzyme-linked immunosorbent assay. The serum immunoglobulin A (IgA) levels and the focus score of labial salivary gland (LSG) in patients with SS were also measured, and the correlation between serum IgA levels and serum CCL28 was explored. In addition, the level of serum CCL28 was compared between two subsets of SS patients who were classified by clinical symptoms and laboratory tests.

RESULTS

SS patients displayed decreased expression of CCL28 mRNA in salivary glands, accompanying more severe pathological injury. Serum levels of CCL28 in both primary and secondary SS patients were significantly lower than those in the HC group, whereas no significant differences were observed between RA patients or SLE patients and HCs. Compared with RA and SLE patients alone, serum levels of CCL28 were dramatically lower in patients with SS secondary to RA or SLE. No remarkable correlation between serum IgA and CCL28 levels was observed, while the focus score of LSG negatively correlated with serum CCL28 levels. Serum levels of CCL28 were lower in SS patients who had dental caries and thrombocytopenia.

CONCLUSION

Serum CCL28 is a useful biomarker in the diagnosis and evaluation of SS.

[Establishment and preliminary application of quantitative real-time PCR assay for the detection of SARS-CoV-2 subgenomic nucleocapsid RNA]

Objective: To establish a rapid and specific quantitative real-time PCR (qPCR) method for the detection of SARS-CoV-2 subgenomic nucleocapsid RNA (SgN) in patients with COVID-19 or environmental samples. Methods: The qPCR assay was established by designing specific primers and TaqMan probe based on the SARS-CoV-2 genomic sequence in Global Initiative of Sharing All Influenza Data (GISAID) database. The reaction conditions were optimized by using different annealing temperature, different primers and probe concentrations and the standard curve was established. Further, the specificity, sensitivity and repeatability were also assessed. The established SgN and genomic RNA (gRNA) qPCR assays were both applied to detect 21 environmental samples and 351 clinical samples containing 48 recovered patients. In the specimens with both positive gRNA and positive SgN, 25 specimens were inoculated on cells. Results: The primers and probes of SgN had good specificity for SARS-CoV-2. The minimum detection limit of the preliminarily established qPCR detection method for SgN was 1.5×10² copies/ml, with a coefficient of variation less than 1%. The positive rate of gRNA in 372 samples was 97.04% (361/372). The positive rates of SgN in positive environmental samples and positive clinical samples were 36.84% (7/19) and 49.42% (169/342), respectively. The positive rate and copy number of SgN in Wild strain were lower than those of SARS-CoV-2 Delta strain. Among the 25 SgN positive samples, 12 samples within 5 days of sampling time were all isolated with virus; 13 samples sampled for more than 12 days had no cytopathic effect. Conclusion: A qPCR method for the detection of SARS-CoV-2 SgN has been successfully established. The sensitivity, specificity and repeatability of this method are good.

Age-related adiposity and beta-cell function: impact on prediabetes and diabetes prevalence in middle-aged and older Han Chinese adults

PURPOSE

To investigate the effect of aging on the prevalence of prediabetes and diabetes, and the influence of aging on the associations among adipose mass, redistribution, β cell function, and the prevalence of hyperglycaemia.

METHOD

This urban-based cross-sectional study included 1033 Chinese Han people, aged 40-65 years. The abdominal subcutaneous fat area (SFA) and visceral fat area (VFA) were determined by magnetic resonance imaging. The prevalence rates of prediabetes and diabetes were analyzed according to age group (40-49, 50-59, and 60-65 years). The effects of aging on abdominal fat mass, adipose distribution, insulin action indexes were also assessed.

RESULTS

Prediabetes and diabetes prevalence gradually increased with age. Both SFA and VFA increased, while SFA/VFA decreased, in the 50-59 and 60-65 years age groups compared to the 40-49 years group. Homeostatic model assessment of insulin resistance (HOMA-IR) increased with fat mass. Homeostatic model assessment of beta-cell function (HOMA-β) and early-phase insulin secretion (∆I30/∆G30) were decreased in the 60-65 years group compared to the younger age groups. Increased age, VFA, and HOMA-IR, as well as decreased HOMA-β, were risk factors for the development of prediabetes and diabetes. The associations between central obesity and the development of prediabetes and diabetes, but not the associations of SFA/VFA, HOMA-IR, and HOMA-β with hyperglycaemia prevalence, weakened with age.

CONCLUSIONS

The prevalence of prediabetes and diabetes increased with age. Central obesity may be related stronger to the development of hyperglycaemia in younger people.

[Predictive value of MRI pelvic measurements for "difficult pelvis" during total mesorectal excision]

Objective: Total mesorectal resection (TME) is difficult to perform for rectal cancer patients with anatomical confines of the pelvis or thick mesorectal fat. This study aimed to evaluate the ability of pelvic dimensions to predict the difficulty of TME, and establish a nomogram for predicting its difficulty. Methods: The inclusion criteria for this retrospective study were as follows: (1) tumor within 15 cm of the anal verge; (2) rectal cancer confirmed by preoperative pathological examination; (3) adequate preoperative MRI data; (4) depth of tumor invasion T1-4a; and (5) grade of surgical difficulty available. Patients who had undergone non-TME surgery were excluded. A total of 88 patients with rectal cancer who underwent TME between March 2019 and November 2021 were eligible for this study. The system for scaling difficulty was as follows: Grade I, easy procedure, no difficulties; Grade II, difficult procedure, but no impact on specimen quality (complete TME); Grade III, difficult procedure, with a slight impact on specimen quality (near-complete TME); Grade IV: very difficult procedure, with remarkable impact on specimen quality (incomplete TME). We classified Grades I-II as no surgical difficulty and grades III-IV as surgical difficulty. Pelvic parameters included pelvic inlet length, anteroposterior length of the mid-pelvis, pelvic outlet length, pubic tubercle height, sacral length, sacral depth, distance from the pubis to the pelvic floor, anterior pelvic depth, interspinous distance, and inter-tuberosity distance. Univariate and multivariate logistic regression analyses were performed to identify the factors associated with the difficulty of TME, and a nomogram predicting the difficulty of the procedure was established. Results: The study cohort comprised 88 patients, 30 (34.1%) of whom were classified as having undergone difficult procedures and 58 (65.9%) non-difficult procedures. The median age was 64 years (56-70), 51 patients were male and 64 received neoadjuvant therapy. The median pelvic inlet length, anteroposterior length of the mid-pelvis, pelvic outlet length, pubic tubercle height, sacral length, sacral depth, distance from the pubis to the pelvic floor, anterior pelvic depth, interspinous distance, and inter-tuberosity distance were 12.0 cm, 11.0 cm, 8.6 cm, 4.9 cm, 12.6 cm, 3.7 cm, 3.0 cm, 13.3 cm, 10.2 cm, and 12.2 cm, respectively. Multivariable analyses showed that preoperative chemoradiotherapy (OR=4.97,95% CI: 1.25-19.71, P=0.023), distance between the tumor and the anal verge (OR=1.31, 95% CI: 1.02-1.67, P=0.035) and pubic tubercle height (OR=3.36, 95% CI: 1.56-7.25, P=0.002) were associated with surgical difficulty. We then built and validated a predictive nomogram based on the above three variables (AUC = 0.795, 95%CI: 0.696-0.895). Conclusion: Our research demonstrated that our system for scaling surgical difficulty of TME is useful and practical. Preoperative chemoradiotherapy, distance between tumor and anal verge, and pubic tubercle height are risk factors for surgical difficulty. These data may aid surgeons in planning appropriate surgical procedures.

Sleep patterns correlates with the efficacy of tDCS on post-stroke patients with prolonged disorders of consciousness

BACKGROUND

The subclassification of prolonged disorders of consciousness (DoC) based on sleep patterns is important for the evaluation and treatment of the disease. This study evaluates the correlation between polysomnographic patterns and the efficacy of transcranial direct current stimulation (tDCS) in patients with prolonged DoC due to stroke.

METHODS

In total, 33 patients in the vegetative state (VS) with sleep cycles or without sleep cycles were randomly assigned to either active or sham tDCS groups. Polysomnography was used to monitor sleep changes before and after intervention. Additionally, clinical scale scores and electroencephalogram (EEG) analysis were performed before and after intervention to evaluate the efficacy of tDCS on the patients subclassified according to their sleep patterns.

RESULTS

The results suggest that tDCS improved the sleep structure, significantly prolonged total sleep time (TST) (95%CI: 14.387-283.527, P = 0.013) and NREM sleep stage 2 (95%CI: 3.157-246.165, P = 0.040) of the VS patients with sleep cycles. It also significantly enhanced brain function of patients with sleep cycles, which were reflected by the increased clinical scores (95%CI: 0.340-3.440, P < 0.001), the EEG powers and functional connectivity in the brain and the 6-month prognosis. Moreover, the changes in NREM sleep stage 2 had a significant positive correlation with each index of the β band.

CONCLUSION

This study reveals the importance of sleep patterns in the prognosis and treatment of prolonged DoC and provides new evidence for the efficacy of tDCS in post-stroke patients with VS patients subclassified by sleep pattern. Trial registration URL: https://www.

CLINICALTRIALS

gov . Unique identifier: NCT03809936. Registered 18 January 2019.

[Prevalence of mountain-zoonotic type visceral leishmaniasis in Yangquan City of Shanxi Province from 2015 to 2020]

OBJECTIVE

To investigate the prevalence of mountain-type zoonotic visceral leishmaniasis (MT-ZVL) in Yangquan City, Shanxi Province from 2015 to 2020, so as to provide the scientific evidence for formulating the MT-ZVL control strategy.

METHODS

The epidemiological data pertaining to MT-ZVL cases in Yangquan City from 2015 to 2020 were collected and descriptively analyzed. A Joinpoint regression model was created to analyze the trend in the MT-ZVL incidence in Yangquan City from 2015 to 2020 using annual percent change (APC). The sandflies surveillance data and the prevalence of Leishmania infections in dogs were collected in Yangquan City in 2020, and the regional distribution of sandflies density and sero-prevalence of Leishmania infections in dogs were calculated. In addition, the associations of sandflies density and sero-prevalence of Leishmania infections in dogs with the incidence of human MT-ZVL were examined using the linear correlation analysis.

RESULTS

A total of 162 MT-ZVL cases were reported in Yangquan City, Shanxi Province from 2015 to 2020, with annual mean incidence of 1.9/10⁵, and there were 4, 7, 16, 27, 33 cases and 75 cases with MT-ZVL reported from 2015 to 2020, appearing a tendency towards a rapid rise (APC = 72.79%, t = 11.10, P < 0.01). MT-ZVL cases were reported across the five counties (districts) of Yangquan City, and the cases predominantly occurred in Jiaoqu District (35.2%, 57/162) and Pingding County (33.3%, 54/162). MT-ZVL cases were predominantly detected in residents at ages of 15 years and older (71.6%, 116/162) and at ages of 0 to 2 years (22.2%, 36/162), with farmers (37.4%, 61/162) and diaspora children (24.5%, 40/162) as predominant occupations. The mean density of Phlebotomus chinensis was 6.3 sandflies per trap per night in Yangquan City from during the period from May to September, 2020, with the highest density observed in Jiaoqu District (12.6 sandflies per trap per night) and the lowest in Yuxian County (1.1 sandflies per trap per night), and there was a region-specific mean density of Ph. chinensis in Yangquan City (H = 17.282, P < 0.01). The sero-prevalence of serum anti-Leishmania antibody was 7.4% (2 996/40 573) in domestic dogs in Yangquan City, with the highest sero-prevalence seen in Jiaoqu District (16.6%, 1 444/8 677), and the lowest in Yuxian County (2.3%, 266/11 501), and there was a region-specific sero-prevalence rate of anti-Leishmania antibody in domestic dogs in Yangquan City (χ² = 1 753.74, P < 0.01). The sero-prevalence of anti-Leishmania antibody was significantly higher in stray dogs (20.0%, 159/794) than in domestic dogs (χ² = 176.63, P < 0.01). In addition, there were significant associations among the sandflies density, sero-prevalence of anti-Leishmania antibody in domestic dogs and the incidence of human MT-ZVL (r = 0.832 to 0.870, all P values < 0.05).

CONCLUSIONS

The prevalence of MT-ZVL appeared a tendency towards a rapid rise in Yangquan City from 2015 to 2020, and systematic interventions are urgently needed for MT-ZVL control.

[Association of lead exposure with stunting and underweight among children aged 3-5 years in China]

Objective: To evaluate the association of lead exposure with stunting and underweight among children aged 3-5 years in China. Methods: Data was collected from China National Human Biomonitoring (CNHBM) between January 2017 and December 2018. A total of 3 554 children aged 3-5 years were included. Demographic characteristic, lifestyle and nutritional status were collected through questionnaires. Height and weight were measured by standardized method. Stunting and underweight status were determined by calculating height for age Z-score and weight for age Z-score. Blood and urine samples were collected to detect the concentrations of blood lead, urinary lead and urinary creatinine. Children were stratified into 4 groups (Q₁ to Q₄) by quartiles of blood lead level and corrected urinary lead level, respectively. Complex sampling logistic regression models were applied to evaluate the association of the blood lead level, urinary lead level with stunting and underweight. Results: Among 3 554 children, the age was (4.09±1.06) years, of which 1 779 (80.64%) were female and 1 948 (55.84%) were urban residents. The prevalence of stunting and wasting was 7.34% and 2.96%, respectively. The M (Q₁, Q₃) for blood lead levels and urinary lead levels in children was 17.49 (12.80, 24.71) μg/L, 1.20 (0.61, 2.14) μg/g Cr, respectively. After adjusting for confounding factors, compared with the lowest blood lead concentration group Q₁, the risk of stunting gradually increased in the Q₃ and Q₄ group (P_trend=0.010), with OR (95%CI) values of 1.40 (0.80-2.46) and 1.80 (1.07-3.04), respectively. Compared with the lowest urinary lead concentration group Q₁, the risk of stunting still increased in the Q₃ and Q₄ group (P_trend=0.012), with OR (95%CI) values of 1.69 (1.01-2.84) and 1.79 (1.05-3.06), respectively. The correlation between the lead exposure and underweight was not statistically significant (P>0.05). Conclusion: Lead exposure is positively associated with the risk of stunting among children aged 3-5 years in China.

[Mediation effect of inflammatory biomarkers on the association between blood lead levels and blood pressure changes in Chinese adults]

Objective: To investigate the role of inflammatory biomarkers in the relationship between blood lead levels and blood pressure changes. Methods: A total of 9 910 people aged 18-79 years who participated in the China National Human Biomonitoring in 2017-2018 were included in this study. A self-made questionnaire was used to collect demographic characteristics, lifestyle and other information, and the data including height, weight and blood pressure were determined through physical examination. Blood and urinary samples were collected for the detection of blood lead and cadmium levels, urinary arsenic levels, white blood cells, neutrophils, lymphocytes, and hypersensitive C-reactive protein (hs-CRP). Weighted linear regression models were used to evaluate the associations between blood lead, inflammatory biomarkers and blood pressure. Mediation analysis was performed to investigate the role of inflammation in the relationship between blood lead levels and blood pressure changes. Results: The median (Q₁, Q₃) age of all participants was 45.4 (33.8, 58.4)years, including 4 984 males accounting for 50.3%. Multivariate logistic regression model analysis showed that after adjusting for age, gender, residence area, BMI, education level, smoking and drinking status, family history of hypertension, consumption frequency of rice, vegetables, and red meat, fasting blood glucose, total cholesterol, triglycerides, blood cadmium and urinary arsenic levels, there was a positive association between blood lead levels, inflammatory biomarkers and blood pressure (P<0.05). Each 2.71 μg/L (log-transformed) increase of the lead was associated with a 2.05 (95%CI: 0.58, 3.53) mmHg elevation in systolic blood pressure (SBP), 2.24 (95%CI: 1.34, 3.14) mmHg elevation in diastolic blood pressure (DBP), 0.25 (95%CI: 0.05, 0.46) mg/L elevation in hs-CRP, 0.16 (95%CI: 0.03, 0.29)×10⁹/L elevation in white blood cells, and 0.11 (95%CI: 0.02, 0.21)×10⁹/L elevation in lymphocytes, respectively. Mediation analysis showed that the levels of hs-CRP significantly mediated the association of blood lead with SBP, with a proportion about 3.88% (95%CI: 0.45%, 7.32%). The analysis also found that the levels of hs-CRP and neutrophils significantly mediated the association of blood lead with SBP, with a proportion about 4.10% (95%CI: 1.11%, 7.10%) and 2.42% (95%CI: 0.07%, 4.76%), respectively. Conclusion: This study suggests that inflammatory biomarkers could significantly mediate the association of blood lead levels and blood pressure changes.

Change in REVEAL Lite 2 and COMPERA 2.0 risk status in patients with pulmonary arterial hypertension initiating oral treprostinil on dual background therapy: a retrospective chart review

Background

Post-hoc analyses of the FREEDOM-EV study demonstrated that addition of oral treprostinil (ORE) to background monotherapy improves risk in patients with pulmonary arterial hypertension (PAH). Evidence is needed to understand the incremental effect of ORE added to dual background therapy with an endothelin receptor antagonist (ERA) and phosphodiesterase-5 inhibitor (PDE5)/soluble guanylate cyclase stimulator (sGC).

Purpose

To describe longitudinal changes in REVEAL Lite 2 and COMPERA 2.0 risk status in patients initiating ORE on dual background therapy.

Methods

A multisite, double-blind retrospective chart review of PAH patients was conducted by US PAH-treating physicians and included patients meeting prior diagnostic PAH criteria (mPAP ≥25 mmHg/PAWP ≤15 mmHg/PVR &gt;3 WU), age ≥18 at diagnosis, began a PAH treatment 01/2014–03/2017, and had NT-proBNP/BNP, WHO functional class (FC), and 6-minute walk distance (6MWD) at baseline visit. Baseline was most recent assessment prior to ORE initiation. This analysis included a subset of patients on dual background therapy at time of ORE initiation without prior prostacyclin use. Follow-up was evaluated in 0–6 and 6–12 months after ORE initiation.

Results

30 (61.2%) of 49 ORE patients were on dual background therapy at time of ORE start; 23 had baseline assessments while on dual background therapy and were included in this analysis. At baseline, mean (SD) 6MWD was 140.9 (49.8) m and 21 (91.3%) patients were FC III. Prior to ORE, median (IQR) time on ERA was 6.6 (5.5–7.6) months and PDE5/sGC was 3.7 (3.3–5.7) months. After ORE start, median (IQR) time to follow-up was 4.3 (3.4–5.6) months in 0–6 months and 10.9 (9.6–11.6) months in 6–12 months. Using REVEAL Lite 2, baseline mean (SD) REVEAL Lite 2 risk score was 7.9 (0.8); 1 (4.4%), 2 (8.7%), and 20 (87%) patients were in the low, intermediate, and high risk strata, respectively. In 0–6 months (n=22), 13 (59.1%) patients improved and 9 (40.9%) stabilized REVEAL Lite 2 risk strata from baseline. In 6–12 months (n=22), mean (SD) REVEAL Lite 2 risk score was 6.5 (1.1); 15 patients (68.2%) improved, 6 (27.3%) stabilized, and 1 (4.6%) worsened REVEAL Lite 2 risk strata from baseline. Using COMPERA 2.0, at baseline, 1 (4.4%) patient was in the intermediate-low and 22 (95.7%) patients were in the intermediate-high risk strata. In 0–6 months (n=15), 10 (66.7%) patients improved and 5 (33.3%) patients stabilized COMPERA 2.0 risk strata from baseline. In 6–12 months (n=17), 15 (88.2%) patients improved and 2 (11.8%) stabilized COMPERA 2.0 risk strata from baseline.

Conclusion

Of patients initiating oral treprostinil in this study, most were on dual background therapy and at high risk by REVEAL Lite 2 or intermediate-high risk by COMPERA 2.0. This analysis suggests adding ORE to dual background therapy can improve risk status in patients, with clinical benefit attained within 6 months and continued incremental improvement through first year of therapy.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): United Therapeutics Corporation

[Role of type 2 innate lymphoid cells in helminth infections: a review]

Helminth infections may trigger host innate and adaptive immune responses. Group 2 innate lymphoid cells (ILC2) are an important factor involved in type 2 immune responses, and produce a large number of T helper 2 cell (Th2) cytokines following stimulation by interleukin (IL)-25, IL-33 and thymic stromal lymphopoietin (TSLP), which play a critical role in parasite clearance and tissue repair. Following helminth infections, autocrine factors, mast cells, enteric nervous system and Th2 cells have been recently found to be involved in regulation of ILC2. Unraveling the role of ILC2 in immune response against helminth infections is of great value for basic research and drug development. This review summarizes the research progress on ILC2 and its role in helminth infections.

Use of a urinary catheter as a guidewire to facilitate safe nasotracheal intubation following iatrogenic retropharyngeal perforation

Nasotracheal intubation facilitates adequate access for surgical procedures in the oral cavity, is not limited by mouth opening and can be better tolerated by patients in intensive care. Complications of nasotracheal intubation can include epistaxis, turbinate injury and sinusitis. Retropharyngeal submucosal perforation by the tracheal tube has also been infrequently reported. Here, we report a case of difficult nasotracheal intubation resulting in retropharyngeal submucosal perforation in a patient with a history of obstructive sleep apnoea listed for uvulopalatopharyngoplasty. To facilitate successful tracheal re-intubation, we used a soft urinary catheter via the other nostril. In this report, we discuss the reasons why this complication may have occurred, how submucosal perforation could be avoided, and reflect on our management of this rare complication. Difficult nasotracheal intubation can present unique challenges, and airway management plans should be made accordingly.

[Deletion of Aldh4a1 Leads to Impaired Sperm Maturation in Mice]

ALDH4A1, a member of the aldehyde dehydrogenase superfamily, is a key enzyme in the mitochondrial proline metabolism pathway. Recent studies have shown that mutations in aldh4a1 lead to reduced fertility and reproductive premature aging of male nematodes. However, the effect of ALDH4A1 on fertility of male mice has not been studied. In this study, we used CRISPR-Cas9 technology to construct a knockout mouse model of Aldh4a1 for the first time to explore the effect of this gene on the reproduction of male mice. The results showed that compared with WT male mice, Aldh4a1^(-/-) male mice were fertile, had normal spermatogenesis but defect in sperm maturation in the epididymis documented by impaired motility, increased morphological abnormalities and increased spontaneous acrosome reaction. In addition, transmission electron microscopy showed vacuoles in the sperm mitochondria, and fracture in the neck of sperms and vacuoles in these mice. These results revealed that ALDH4A1 plays a vital role in the structure of sperm flagellum and the process of sperm maturation in mice.

Effects of Selenium Supplementation on the Ion Homeostasis in the Reproductive Organs and Eggs of Laying Hens Fed With the Diet Contaminated With Cadmium, Lead, Mercury, and Chromium

The objective of this study was to explore the toxic effects of different heavy metals in combination with their deposition and ion homeostasis in the reproductive organs and eggs of laying hens, as well as the alleviating action of selenized yeast. A total of 160 Lohmann pink-shell laying hens (63-week-old) were randomly allocated into four treatments with 10 replicates of four hens each. The four dietary treatments were the corn-soybean meal basal dietary (control; CON); the CON dietary supplemented with 0.4 mg/kg selenium from selenized yeast (Se); the CON dietary supplemented with 5 mg/kg Cd + 50 mg/kg Pb +3 mg/kg Hg + 5 mg/kg Cr (HEM), and the HEM dietary supplemented with 0.4 mg/kg selenium from selenized yeast (HEM+Se). The dietary HEM significantly increased Cd, Pb, and Hg deposition in the egg yolk and ovary, and Cd and Hg deposition in the oviduct and in the follicular wall (p < 0.05). The HEM elevated Fe concentration in the egg yolk, ovary, and oviduct (p < 0.05). The HEM decreased Mn concentration in the egg yolk, Fe, Mn, and Zn concentrations in the egg white, Cu concentration in the ovary, Mg concentration in the oviduct, as well as Ca, Cu, Zn, and Mg concentrations in the follicular walls (p < 0.05). Dietary Se addition elevated Se concentration in the egg yolk, oviduct, and follicular walls and Mg concentration (p < 0.05) in the oviduct, whereas it reduced Fe concentration in the oviduct compared with the HEM-treated hens. Some positive or negative correlations among these elements were observed. Canonical Correlation Analysis showed that the concentrations of Pb and Hg in the egg yolk were positively correlated with those in the ovary. The concentration of Cd in the egg white was positively correlated with that in the oviduct. In summary, dietary Cd, Pb, Hg, and Cr in combination caused ion loss and deposition of HEM in reproductive organs of laying hens. Dietary Se addition at 0.4 mg/kg from selenized yeast alleviated the negative effects of HEM on Fe and Mg ion disorder in the oviduct and follicle wall of hens.

[Analysis of prognosis factors of postoperative cardiac complications in colorectal cancer patients with comorbid coronary artery disease]

Objective: To examine the prognosis factors of postoperative cardiac complications in colorectal cancer patients co-morbidated with coronary artery disease. Methods: Clinical data of 449 patients colorectal cancer patients co-morbidated with coronary artery disease accepted redical surgery from April 2013 to April 2020 at Department of General Surgery, Peking Union Medical College Hospital were analyzed retrospectively. There were 306 males and 143 females, aging (68.7±8.9) years (range: 44 to 89 years). Postoperative acute coronary syndrome, new-onset arrhythmia and heart failure that causes clinical symptoms were recorded as cardiac complications. t test, χ2 test and Fisher exact test were used for univariate analysis of prognosis factors of postoperative cardiac events. The variables with P<0.05 were included in the multivariate Logistic regression was used to determine the independent prognosis factors. Results: After surgery, 44 patients (9.8%) suffered from at least one cardiac event, including 30 patients with acute coronary syndrome, 19 patients with new-onset arrhythmia and 9 patients with heart failure. There were 3 deaths in the cohort within 30 days after surgery. Two patients died from cardiac-related complications, and one from septic shock due to postoperative anastomotic leaks. On Univariate analysis showed that cardiac complications were associated with age ≥80 years, co-morbidated diabetes, emergency surgery, re-operation, anastomotic leakage, intestinal flora disorder and elevation of preoperative neutrophil-lymphocyte ratio (χ2: 4.308 to 12.219, all P<0.05). Multivariate Logistic regression analysis identified age ≥80 years(OR=3.195, 95%CI: 1.379 to 7.407, P=0.007), co-morbidated diabetes (OR=2.551, 95%CI: 1.294 to 5.025, P=0.007), emergency surgery (OR=4.717, 95%CI: 1.052 to 20.833, P=0.043), and elevated preoperative neutrophil-lymphocyte ratio (OR=1.114, 95%CI: 1.018 to 1.218, P=0.018) as independent prognosis factors for cardiac complications. Conclusions: Emergency surgery, advanced age, co-morbidated type 2 diabetes and elevated preoperative neutrophil-lymphocyte ratio may increase the risk of postoperative cardiac complications in colorectal cancer patients with coronary artery disease. Surgeons should strictly master surgical indications, pay attention to preoperative assessment, perioperative monitoring, and diagnosis and treatment of postoperative complications in order to reduce the risk of complications.

[Safety and prognosis analysis of transanal total mesorectal excision versus laparoscopic mesorectal excision for mid-low rectal cancer]

Objective: To compare the short-term and long-term outcomes between transanal total mesorectal excision (taTME) and laparoscopic total mesorectal excision (laTME) for mid-to-low rectal cancer and to evaluate the learning curve of taTME. Methods: This study was a retrospective cohort study. Firstly, consecutive patients undergoing total mesorectal excision who were registered in the prospective established database of Division of Colorectal Diseases, Department of General Surgery, Peking Union Medical College Hospital during July 2014 to June 2020 were recruited. The enrolled patients were divided into taTME and laTME group. The demographic data, clinical characteristics, neoadjuvant treatment, intraoperative and postoperative complications, pathological results and follow-up data were extracted from the database. The primary endpoint was the incidence of anastomotic leakage and the secondary endpoints included the 3-year disease-free survival (DFS) and the 3-year local recurrence rate. Independent t-test for comparison between groups of normally distributed measures; skewed measures were expressed as M (range). Categorical variables were expressed as examples (%) and the χ(2) or Fisher exact probability was used for comparison between groups. When comparing the incidence of anastomotic leakage, 5 variables including sex, BMI, clinical stage evaluated by MRI, distance from tumor to anal margin evaluated by MRI, and whether receiving neoadjuvant treatment were balanced by propensity score matching (PSM) to adjust confounders. Kaplan-Meier curve and Log-rank test were used to compare the DFS of two groups. Cox proportional hazard model was used to analyze and determine the independent risk factors affecting the DFS of patients with mid-low rectal cancer. Secondly, the data of consecutive patients undergoing taTME performed by the same surgical team (the trananal procedures were performed by the same main surgeon) from February 2017 to March 2021 were separately extracted and analyzed. The multidimensional cumulative sum (CUSUM) control chart was used to draw the learning curve of taTME. The outcomes of 'mature' taTME cases through learning curve were compared with laTME cases and the independent risk factors of DFS of 'mature' cases were also analyzed. Results: Two hundred and forty-three patients were eventually enrolled, including 182 undergoing laTME and 61 undergoing taTME. After PSM, both fifty-two patients were in laTME group and taTME group respectively, and patients of these two groups had comparable characteristics in sex, age, BMI, clinical tumor stage, distance from tumor to anal margin by MRI, mesorectal fasciae (MRF) and extramural vascular invasion (EMVI) by MRI and proportion of receiving neoadjuvant treatment. After PSM, as compared to laTME group, taTME group showed significantly longer operation time [(198.4±58.3) min vs. (147.9±47.3) min, t=-4.321, P<0.001], higher ratio of blood loss >100 ml during surgery [17.3% (9/52) vs. 0, P=0.003], higher incidence of anastomotic leakage [26.9% (14/52) vs. 3.8% (2/52), χ(2)=10.636, P=0.001] and higher morbidity of overall postoperative complications [55.8%(29/52) vs. 19.2% (10/52), χ(2)=14.810, P<0.001]. Total harvested lymph nodes and circumferential resection margin involvement were comparable between two groups (both P>0.05). The median follow-up for the whole group was 24 (1 to 72) months, with 4 cases lost, giving a follow-up rate of 98.4% (239/243). The laTME group had significantly better 3-year DFS than taTME group (83.9% vs. 73.0%, P=0.019), while the 3-year local recurrence rate was similar in two groups (1.7% vs. 3.6%, P=0.420). Multivariate analysis showed that and taTME surgery (HR=3.202, 95%CI: 1.592-6.441, P=0.001) the postoperative pathological staging of UICC stage II (HR=13.862, 95%CI:1.810-106.150, P=0.011), stage III (HR=8.705, 95%CI: 1.104-68.670, P=0.040) were independent risk factors for 3-year DFS. Analysis of taTME learning curve revealed that surgeons would cross over the learning stage after performing 28 cases. To compare the two groups excluding the cases within the learning stage, there was no significant difference between two groups after PSM no matter in the incidence of anastomotic leakage [taTME: 6.7%(1/15); laTME: 5.3% (2/38), P=1.000] or overall complications [taTME: 33.3%(5/15), laTME: 26.3%(10/38), P=0.737]. The taTME was still an independent risk factor of 3-year DFS only analyzing patients crossing over the learning stage (HR=5.351, 95%CI:1.666-17.192, P=0.005), and whether crossing over the learning stage was not the independent risk factor of 3-year DFS for mid-low rectal cancer patients undergoing taTME (HR=0.954, 95%CI:0.227-4.017, P=0.949). Conclusions: Compared with conventional laTME, taTME may increase the risk of anastomotic leakage and compromise the oncological outcomes. Performing taTME within the learning stage may significantly increase the risk of postoperative anastomotic leakage.

The efficacy and safety of different doses of calcitriol combined with neutral phosphate in X-linked hypophosphatemia: a prospective study

The present study was the first prospective cohort evaluated the efficacy and safety of different doses of calcitriol in XLH children. The results suggested that a dose of 40 ng/kg/day calcitriol, compared with 20 ng/kg/day, was more effective in relieving the rickets, with similar safety outcomes. Further investigations were expected to set more dose groups.

INTRODUCTION

Dose recommended for calcitriol in X-linked hypophosphatemia (XLH) varies in different studies. Therefore, we aimed to compare the efficacy as well as the safety of 20 ng/kg/d and 40 ng/kg/d calcitriol in Chinese XLH pediatrics population.

METHODS

A 2-year, randomized, open-label, prospective study recruited 68 XLH children, which were randomized to receive either 40 ng/kg/day or 20 ng/kg/day calcitriol. Efficacy endpoints were the total Thacher ricket severity score (RSS) change from baseline to month 12 and 24, the difference in serum TALP level, fasting serum phosphate level, body height Z-score, and frequency of dental abscess. Safety assessments were done using renal ultrasound nephrocalcinosis grades (0-4), fasting serum and 24 h urine calcium level, and the occurrence of hyperparathyroidism.

RESULTS

The decrease in the total RSS from baseline was more significant in the high-dose group at 12 (difference 0.87, p = 0.049) and 24 month (difference 1.23, p = 0.011). The serum TALP level was significantly lower in the high-dose group at 6 months. Pi level, height Z-score change, frequency of dental abscess and ratio of de novo nephrocalcinosis were comparable. A lower incidence of secondary hyperparathyroidism was seen in the high-dose group (p < 0.0001).

CONCLUSION

For the first time in this prospective cohort, 40 ng/kg/d calcitriol was shown to be the more effective therapy in XLH children than the 20 ng/kg/d. Moreover, 40 ng/kg/d calcitriol was not associated with increasing adverse events.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT 03,820,518.

POS0136 COMPLEMENT C1q PROMOTES MITOCHONDRIA RESPIRATION AND SECRETION OF IL-6 and IL-1β BUT NOT TNF-α BY SYNOVIAL MACROPHAGE IN RHEUMATOID ARTHRITIS

Background

Complement C1q (C1q), predominantly synthesized by myeloid cells such as macrophages, has elusive functions in the pathogenesis of rheumatic arthritis (RA). Binding to its receptor gC1qR, C1q can activate mitochondria, the dysfunction of which may result in tissue inflammatory disease [1]. Bone marrow derived macrophages in RA patients have elevated OXPHOS activity [2], while the reason remains to be discovered.

Objectives

The objectives of the study were to explore the expression of C1q and its receptor gC1qR in synovial macrophages in RA and whether C1q contributes to tissue inflammation via affecting pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) and mitochondria respiration in synovial macrophages.

Methods

Tissue transcriptome analysis for C1q(C1qA, C1qB and C1qC), C1q receptors (including gC1qR) in rheumatoid synovium and and pro-inflammatory cytokines (IL-6, IL-1β and TNF-α) in rheumatoid synovium and synovium macrophages were quantified by RT-PCR. Concentrations of C1q in the plasma of RA and healthy controls (HC) were analyzed by ELISA and the correlation between plasma C1q and disease activty measured by DAS28 were calculated. gC1qR protein expression was detected by flow cytometric analysis and immunoblotting. Synovial macrophages were isolated and stimulated with or without C1q for 24 h. Function of gC1qR was analysed by knockdown experiment using siRNA. Transcripts for inflammatory cytokines were quantified by RT-PCR. Mitochondrial respirometer was evaluated with Seahorse Bioscience XF96 analyzer after C1q treatment or gC1qR knockdown.

Results

C1qA, C1qB,C1qC and gC1qR were all upregulated in both rheumatoid synovium and synovial macrophages compared to healthy controls. Meanwhile, RA patients had a higher level of C1q concentration in plasma, which positively correlated with DAS28. Moreover, an increased expression of gC1qR protein was confirmed by flow cytometric analysis and immunoblotting. Besides, C1q could increase the expression of IL-6 and IL-1β but not TNF-α in synovial macrophages. We also found that C1q could increase basal OCR, ATP-coupled OCR, max respiration and reserve capacity of healthy macrophages. Comparatively, gC1qR knockout could down-regulate mitochondria respiration of RA macrophages.

Conclusion

Synovial macrophages in RA patients have significantly elevated expression of C1q and its receptor gC1qR. C1q could promote mitochondria respiration through gC1qR, thus leading to hyper-metabolism in macrophages from RA patients. C1q could promote synovitis through enhanced pro-inflammatory cytokines IL-6 and IL-1β but not TNF-α secreted by synovial macrophages, which represents a novel therapeutic target in RA.

References

[1]Weyand CM, Goronzy JJ. A Mitochondrial Checkpoint in Autoimmune Disease. Cell Metab 2018; 28: 185-186.

[2]M. Zeisbrich, R.E. Yanes, H. Zhang, R. Watanabe, Y. Li, L. Brosig, et al., Hypermetabolic macrophages in rheumatoid arthritis and coronary artery disease due to glycogen synthase kinase 3b inactivation. Ann Rheum Dis 2018; 77: 1053-1062.

Figure 1.

The expression and function of C1q in RA macrophage. A.Transcripts for gC1qR, C1qA, C1qB and C1qC and pro-inflammatory cytokines were quantified by RT-PCR in synovial macrophage of RA and healthy control (HC), n=6; B. Concentrations of C1q in the plasma of RA and HC were measured by ELISA, n=8; C-D. Transcripts for pro-inflammatory cytokines were quantified by RT-PCR after C1q treatment, n=9; E-I. Mitochondrial respirometer was evaluated with Seahorse Bioscience XF96 analyzer by adding test agents in order of 1, oligomycin; 2, FCCP; 3, anti-mycin A/rotenone. Total trend and each segmentation of oxygen consumption rates (OCR) were shown after treated with C1q, n=6. *P < 0.05; **P < 0.01; ***P < 0.001.

Disclosure of Interests

Yutong Jiang Grant/research support from: Basic and Applied Basic Research Fund Project of Guandong Province [2021A1515111172]., Bowen Wu: None declared, Tao Huang: None declared, Yan Liu: None declared, Zhaolan Hu: None declared, Tuantuan Zhao: None declared, Yunfeng Pan: None declared, Weyand Cornelia: None declared

Fertilizer P-derived uranium continues to accumulate at Rothamsted long-term experiments

The application of phosphorus (P) fertilizers inevitably contributes to the accumulation of trace elements, such as uranium (U), in agricultural soils. The fertilizer-derived U accumulation was first reported in Rothamsted Research in 1979. In the present study, we expand this early key research by evaluating the fertilizer-derived U accumulation in topsoil (0-23 cm) from 1876 to the 2010s. We found that total U accumulation rates ranged from 2.8 to 6.1 μg U kg^-1 yr^-1 at the Broadbalk and Park Grass, respectively, being similar to those observed 40 years ago. This highlights that U accumulation is still an ongoing process in Rothamsted. Fortunately, the proportion of fertilizer-derived U did not significantly increase in the ammonium acetate extractable ('proxy' of plant-available) fraction over 130 years. In addition, we compiled an overview of the global rate of mineral P fertilizer-derived U accumulation in agricultural systems using existing literature (36 experimental trials, from 11 countries). The resulting dataset predicts an estimated mean U accumulation of 0.85 μg U kg^-1 soil for an annual application of 1 kg P ha^-1 in the topsoil of agricultural systems (0.26 μg U kg^-1 per kg P ha^-1 for arable land and 1.34 μg U kg^-1 per kg P ha^-1 for grassland). The annual U accumulation per applied kg P ha^-1 being 0.08 (Broadbalk) and 0.17 μg U (Park Grass) corresponds to around one-third and one-eighth of the worldwide mean U accumulation for their respective agricultural systems, suggesting 'relatively' low U contents of the applied P fertilizers. Our study underscores that fertilizer-derived U accumulation is a persistent problem on the global scale, even if at different rates, and therewith suggests an evaluation of current regulatory limits and acceptable U input levels from P fertilization.