[Interpretation of the reporting specifications for mixed methods systematic reviews]

The number of mixed methods systematic reviews (MMSRs) published internationally is increasing day by day, thanks to the continuous development and improvement of MMSRs methodological guidelines and reporting specification, which effectively promote the depth and breadth of evidence synthesis and integration results. However, the application of this method has yet to be popularized in China. With the continuous development of mixed methods research and evidence-based medicine in our country, the number of MMSRs will gradually increase. This paper aims to analyze the reporting specifications for MMSRs with cases to improve the quality of evidence integration and reporting standardization of domestic relevant researchers in MMSRs.

[Association between sleep status in the first trimester and preterm birth]

Objective: To investigate the relationship between sleep status in the first trimester and preterm birth. Methods: Clinical data of pregnant women who received regular prenatal examination and delivered in Peking University Third Hospital from September 1, 2019 to June 10, 2020 were collected. The Pittsburgh sleep quality index (PSQI) was used to investigate their sleep status during 8-12 weeks of gestation, and the delivery outcomes were followed up. According to the gestational age at delivery and the cause of preterm birth, they were divided into full-term delivery group (204 cases), preterm birth group (13 cases) and spontaneous preterm birth group (9 cases). The correlation between the sleep status in the first trimester and preterm birth or spontaneous preterm birth was analyzed. Results: The median PSQI score of full-term delivery group was 4.0 points (3.0, 6.0 points), which was lower than those of preterm delivery group [6.0 points (4.0, 8.0 points)] and spontaneous preterm delivery group [7.0 points (4.0, 8.0 points)], and the differences were statistically significant (all P<0.05). The proportion of pregnant women with poor sleep quality (PSQI score>7 points) in full-term delivery group [14.2% (29/204)] was lower than those in preterm delivery group (5/13) and spontaneous preterm delivery group (4/9), and the differences were statistically significant (all P<0.05). Compared with the full-term delivery group [8.0 hours (7.0, 9.0 hours)], the preterm birth group [7.0 hours (7.0, 8.0 hours)] and spontaneous preterm birth group [7.0 hours (7.0, 8.0 hours)] had significantly shorter sleep duration at night (all P<0.05). Multivariate analysis showed that PSQI score in the first trimester was an independent risk factor for preterm birth (aOR=1.22, 95%CI: 1.02-1.45; P=0.026). Pregnancy with assisted reproductive technology (aOR=5.55, 95%CI: 1.22-25.31; P=0.027), gestational diabetes mellitus (aOR=9.27, 95%CI: 1.96-43.82; P=0.005), PSQI score in the first trimester (aOR=1.27, 95%CI: 1.01-1.58; P=0.039) were independent risk factors for spontaneous preterm birth. Conclusion: Attention should be paid to the decreased sleep quality in the first trimester, which might significantly increase the risk of preterm birth and spontaneous preterm birth.

Structural mechanisms of Tad pilus assembly and its interaction with an RNA virus

Caulobacter crescentus Tad (tight adherence) pili, part of the type IV pili family, are crucial for mechanosensing, surface adherence, bacteriophage (phage) adsorption, and cell-cycle regulation. Unlike other type IV pilins, Tad pilins lack the typical globular β sheet domain responsible for pilus assembly and phage binding. The mechanisms of Tad pilus assembly and its interaction with phage ΦCb5 have been elusive. Using cryo-electron microscopy, we unveiled the Tad pilus assembly mechanism, featuring a unique network of hydrogen bonds at its core. We then identified the Tad pilus binding to the ΦCb5 maturation protein (Mat) through its β region. Notably, the amino terminus of ΦCb5 Mat is exposed outside the capsid and phage/pilus interface, enabling the attachment of fluorescent and affinity tags. These engineered ΦCb5 virions can be efficiently assembled and purified in Escherichia coli, maintaining infectivity against C. crescentus, which presents promising applications, including RNA delivery and phage display.

Removal of Pseudomonas type IV pili by a small RNA virus

The retractile type IV pilus (T4P) is important for virulence of the opportunistic human pathogen Pseudomonas aeruginosa. The single-stranded RNA (ssRNA) phage PP7 binds to T4P and is brought to the cell surface through pilus retraction. Using fluorescence microscopy, we discovered that PP7 detaches T4P, which impairs cell motility and restricts the pathogen's virulence. Using cryo-electron microscopy, mutagenesis, optical trapping, and Langevin dynamics simulation, we resolved the structure of PP7, T4P, and the PP7/T4P complex and showed that T4P detachment is driven by the affinity between the phage maturation protein and its bound pilin, plus the pilus retraction force and speed, and pilus bending. Pilus detachment may be widespread among other ssRNA phages and their retractile pilus systems and offers new prospects for antibacterial prophylaxis and therapeutics.

Structural basis of Acinetobacter type IV pili targeting by an RNA virus

Acinetobacters pose a significant threat to human health, especially those with weakened immune systems. Type IV pili of acinetobacters play crucial roles in virulence and antibiotic resistance. Single-stranded RNA bacteriophages target the bacterial retractile pili, including type IV. Our study delves into the interaction between Acinetobacter phage AP205 and type IV pili. Using cryo-electron microscopy, we solve structures of the AP205 virion with an asymmetric dimer of maturation proteins, the native Acinetobacter type IV pili bearing a distinct post-translational pilin cleavage, and the pili-bound AP205 showing its maturation proteins adapted to pilin modifications, allowing each phage to bind to one or two pili. Leveraging these results, we develop a 20-kilodalton AP205-derived protein scaffold targeting type IV pili in situ, with potential for research and diagnostics.

Spatial propagation of temperate phages within and among biofilms

Bacteria form groups comprised of cells and secreted adhesive matrix that controls their spatial organization. These groups - termed biofilms - can act as refuges from environmental disturbance and from biotic threats, including phages. Despite the ubiquity of temperate phages and bacterial biofilms, temperate phage propagation within biofilms has never been characterized on multicellular spatial scales. Here, we leverage several approaches to track temperate phages and distinguish between lytic and lysogenic infections. We determine that lysogeny within E. coli biofilms most often occurs within a predictable region of cell group architecture. Because lysogens are generally found on the periphery of large groups, where lytic viral activity also reduces local structural integrity, lysogens are predisposed to disperse and are over-represented in biofilms formed downstream of the original biofilm-phage system. Comparing our results with those for virulent phages reveals that the temperate phages possess previously unknown advantages for propagation in architecturally heterogeneous biofilm communities.

[The interpretation of the updated American Urological Association guideline of interstitial cystitis/bladder pain syndrome in 2022]

In 2022, American Urological Association updated the guideline for the diagnosis and treatment of interstitial cystitis/bladder pain syndrome (IC/BPS). A significant change has been made in treatment recommendations. The updated guideline no longer divided treatments into first-line through sixth-line tiers. Instead, treatment is categorized into behavioral/non-pharmacologic, oral medicines, bladder instillations, procedures, and major surgery. This change emphasizes the heterogeneity of IC/BPS patients and the importance of individualized treatment, overturns traditional unreasonable ideas about hierarchical and progressive treatment, and encourages patients and physicians to make treatment decisions together. At the same time, the panel emphasized the importance of early implementation of cystoscopy in patients suspected of Hunner lesions and warned against the possibility of pentosan polysulfate causing a unique retinal pigmentary maculopathy. Urinary reconstruction surgery was considered to only be used as a last resort for the treatment of IC/BPS, and there is uncertainty about the overall balance between benefits and risks/burdens. The updated guideline provides a new understanding and decision-making basis for the diagnosis and treatment of IC/BPS. However, it should be noted that the clinical characteristics of Chinese patients should be considered in practice and the application of the guideline should be localized.

Vegetation-fire feedbacks increase subtropical wildfire risk in scrubland and reduce it in forests

Climate dictates wildfire activity around the world. But East and Southeast Asia are an apparent exception as fire-activity variation there is unrelated to climatic variables. In subtropical China, fire activity decreased by 80% between 2003 and 2020 amid increased fire risks globally. Here, we assessed the fire regime, vegetation structure, fuel flammability and their interactions across subtropical Hubei, China. We show that tree basal area (TBA) and fuel flammability explained 60% of fire-frequency variance. Fire frequency and fuel flammability, in turn, explained 90% of TBA variance. These results reveal a novel system of scrubland-forest stabilized by vegetation-fire feedbacks. Frequent fires promote the persistence of derelict scrubland through positive vegetation-fire feedbacks; in forest, vegetation-fire feedbacks are negative and suppress fire. Thus, we attribute the decrease in wildfire activity to reforestation programs that concurrently increase forest coverage and foster negative vegetation-fire feedbacks that suppress wildfire.

[Comparison of efficacy and safety between domestic immune checkpoint inhibitors and pembrolizumab in the treatment of driver gene-negative advanced non-small cell lung cancer]

Objective: To compare the efficacy and safety of domestic immune checkpoint inhibitors and pembrolizumab in the treatment of driver gene-negative advanced non-small cell lung cancer. Methods: A retrospective analysis was conducted on the data of 1 241 patients with driver gene-negative, unresectable stage ⅢB to Ⅳ non-small cell lung cancer who were treated at the Hunan Cancer Hospital from January 1, 2017 to October 1, 2022. All patients received monotherapy or combination therapy with domestic immune checkpoint inhibitors or pembrolizumab. Among the 1 241 patients, there were 1 066 males and 175 females, with an age range of 14 to 84 years and a median age of 62 years. Among them, 67 patients received monotherapy with domestic immune checkpoint inhibitors, 695 patients received combination therapy with domestic immune checkpoint inhibitors, 102 patients received monotherapy with pembrolizumab, and 377 patients received combination therapy with pembrolizumab. The efficacy and safety of domestic immune checkpoint inhibitors and pembrolizumab monotherapy or combination therapy were compared. Results: In the immune checkpoint inhibitor monotherapy group, the objective response rate (ORR) using domestic immune checkpoint inhibitors and pembrolizumab was 43.3%(29/67) and 44.1%(45/102), respectively, and the disease control rate (DCR) was 79.1%(53/67) and 84.3%(86/102), respectively, with no statistically significant differences (both P>0.05). In the immune combination therapy group, the ORR using domestic immune checkpoint inhibitors and pembrolizumab was 60.9%(423/695) and 62.9%(237/377), respectively, and the DCR was 92.9%(646/695) and 91.0%(343/377), respectively, with no statistically significant differences (both P>0.05). In the immune checkpoint inhibitor monotherapy group, the median progression-free survival (PFS) using domestic immune checkpoint inhibitors and pembrolizumab was 9.0 (95%CI: 3.0-15.0) months and 7.4 (95%CI: 4.8-9.8) months, respectively, with no statistically significant differences (P=0.660). The median overall survival (OS) was 27.0 (95%CI: 25.0-29.0) months and 22.0 (95%CI: 17.1-26.9) months, respectively, with no statistically significant differences (P=0.673). In the immune combination therapy group, the median PFS using domestic immune checkpoint inhibitors and pembrolizumab was 9.0 (95%CI: 8.2-9.8) months and 10.5 (95%CI: 9.0-12.0) months, respectively, with no statistically significant differences (P=0.186). The median OS was 24.0 (95%CI: 19.1-28.9) months and 26.0 (95%CI: 21.3-30.7) months, respectively, with no statistically significant differences (P=0.359). The incidence of grade 1-2 reactive capillary proliferation of the skin in the domestic immune checkpoint inhibitor group and pembrolizumab group was 14.0% (107/762) and 0, respectively. The incidence of grade≥3 reactive capillary proliferation of the skin was 1.0% (7/762) and 0, respectively, with statistically significant differences (both P<0.05). No statistically significant differences were observed in other adverse reactions (all P>0.05). Conclusions: The efficacy of domestically produced immune checkpoint inhibitors is comparable to that of pembrolizumab in the treatment of driver gene-negative advanced non-small cell lung cancer. There is little difference in safety, except for the specific difference in domestically produced immune checkpoint inhibitor, which has a unique risk of reactive cutaneous capillary endothelial proliferation.

[Preliminary analysis of seasonal pollen allergens of allergic rhinitis in a hospital of Nanchang City]

The study was aimed to analyze the seasonal pollen allergen spectrum of patients with allergic rhinitis (AR) in Nanchang city, and to provide evidence for improving the clinical diagnosis, treatment, prevention and epidemiology of seasonal AR. A retrospective analysis was conducted on the results of skin prick test (SPT) among 1 752 patients with AR in outpatient at Department of Otolaryngology, the First Affiliated Hospital of Nanchang University from September 2020 to August 2021 (a total of 1 069 males and 683 females, age ranged from 2 to 84 years old). SPSS 22.0 software was used to analyze the positive rates of main allergens and their differences in gender, age, and month of visit. Differences among groups were compared by student t test, Wilcox rank sum test, or χ2 test. The results showed that among 1 752 SPT-positive patients, the number of simple seasonal AR and the number of perennial combined seasonal AR were 102 (5.82%) and 281 (16.04%), respectively. There was no significant difference between male and female patients in positive seasonal pollen allergens (χ2=2.181, P>0.05), but the positive rate of indoor seasonal pollen allergens in males was higher than that in females (χ2=7.901, P<0.05). The seasonal pollen allergens ranking top 5 of the positive rates were willow (6.62%, 116/1 752), humulus scandens (5.71%, 100/1 752), rape (5.54%, 97/1 752), grey pigweed (4.62%, 81/1 752) and birch (3.60%, 63/1 752). The positive rates of indoor and seasonal pollen allergens increased first and then decreased in different age groups, and the highest positive rates of seasonal pollen allergens were in the age group of 31-40 years old, with statistical significance compared with other groups (χ2=61.269, P<0.05). The seasonal allergen positive rate showed two peaks in time: March to May and September to November. The positive rate of pollen in spring was 60.27% (132/219), which was significantly higher than that in autumn (39.73%,87/219) (χ2=9.247, P<0.05). The positive rate of pollen combination in spring and autumn was 68.29% (112/164), which was significantly higher than that in spring and autumn alone (18.9%,31/164) and (12.8%, 21/164) (χ2=14.731, P<0.05). In summary, pollen allergy in Nanchang City cannot be ignored, accounting for more than 20% of the total number of AR. The incidence of seasonal AR in Nanchang City showed two peaks (March to May and September to November). The common allergens for seasonal AR in Nanchang City were willow, humulus scandens, rape, grey chenopods and birch.

Developmental programming: Impact of preconceptional and gestational exposure to a real-life environmental chemical mixture on maternal steroid, cytokine and oxidative stress milieus in sheep

BACKGROUND

Gestational exposure to environmental chemicals (ECs) is associated with adverse, sex-specific offspring health effects of global concern. As the maternal steroid, cytokine and oxidative stress milieus can have critical effects on pregnancy outcomes and the programming of diseases in offspring, it is important to study the impact of real-life EC exposure, i.e., chronic low levels of mixtures of ECs on these milieus. Sheep exposed to biosolids, derived from human waste, is an impactful model representing the ECs humans are exposed to in real-life. Offspring of sheep grazed on biosolids-treated pasture are characterized by reproductive and metabolic disruptions.

OBJECTIVE

To determine if biosolids exposure disrupts the maternal steroid, cytokine and oxidative stress milieus, in a fetal sex-specific manner.

METHODS

Ewes were maintained before mating and through gestation on pastures fertilized with biosolids (BTP), or inorganic fertilizer (Control). From maternal plasma collected mid-gestation, 19 steroids, 14 cytokines, 6 oxidative stress markers were quantified. Unpaired t-test and ANOVA were used to test for differences between control and BTP groups (n = 15/group) and between groups based on fetal sex, respectively. Correlation between the different markers was assessed by Spearman correlation.

RESULTS

Concentrations of the mineralocorticoids - deoxycorticosterone, corticosterone, the glucocorticoids - deoxycortisol, cortisol, cortisone, the sex steroids - androstenedione, dehydroepiandrosterone, 16-OH-progesterone and reactive oxygen metabolites were higher in the BTP ewes compared to Controls, while the proinflammatory cytokines IL-1β and IL-17A and anti-inflammatory IL-36RA were decreased in the BTP group. BTP ewes with a female fetus had lower levels of IP-10.

DISCUSSION

These findings suggest that pre-conceptional and gestational exposure to ECs in biosolids increases steroids, reactive oxygen metabolites and disrupts cytokines in maternal circulation, likely contributors to the aberrant phenotypic outcomes seen in offspring of BTP sheep - a translationally relevant precocial model.

Stereotactic Body Radiotherapy (SBRT) for Breast Cancer Spinal Metastases is Associated with Low Rates of Long-Term Local Failure (LF) and Vertebral Compression Fracture (VCF) Independent of Molecular Status

PURPOSE/OBJECTIVE(S)

There is limited outcome data specific to breast cancer spinal metastases following spine SBRT. This study aims to report outcomes specific to breast cancer spinal metastases receiving spine SBRT and determine the implication of biomarker status.

MATERIALS/METHODS

We have been maintaining a prospective database since the inception of the spine SBRT program. A retrospective review identified 168 breast cancer patients with 409 spinal segments treated with spine SBRT between January 2008 and January 2023. Molecular subtypes were grouped based on luminal A, luminal B, basal, and HER2 enriched. Patients were followed with q3-monthly full-spine MRI and a clinical assessment. The primary endpoint was MRI-based local failure (LF), and secondary endpoints were overall survival (OS) and vertebral compression fracture (VCF).

RESULTS

The median follow-up was 33 months (range, 3.3-123 months). Amongst the 168 patients, the majority were ECOG 0 or 1 (95%), neurologically intact (94%), polymetastatic (74%), and either luminal A (71%) or luminal B (8%). A total of 17% of patients were HER2+ve versus 83% HER2-ve. Of 409 treated segments the majority (76%) had no prior radiation or surgery (de novo), were SINS stable (60%), had either no or low-grade epidural disease (86%) and treated with 24-28 Gy in 2 fractions (73%). The LF and OS rates at 1, 3, and 5 years were 5%, 11%, and 14%, respectively, and 91%, 65%, and 45%, respectively, independent of molecular subtype on univariate analyses. The cumulative risk of VCF at 2 and 5 years was 7% and 10%, respectively.

CONCLUSION

We observe, in the largest breast cancer spine cohort to date, excellent long-term local control rates independent of molecular sub-group, and acceptable VCF rates.

Anaemia prevalence and risk factors among children aged 6 to 23 months in rural China

INTRODUCTION

Anaemia is a global public health problem among children. However, few studies have examined anaemia prevalence and risk factors among Chinese children of different ages, particularly in poor rural areas. This study investigated these two aspects among children aged 6 to 23 months in poor rural areas of China.

METHODS

This cross-sectional study included 1132 children aged 6 to 23 months in three prefectures of the Qinba Mountains area. A finger prick blood test for haemoglobin and anaemia was conducted, along with household surveys of socio-demographic characteristics, illness characteristics, and feeding practices. Multiple linear and logistic regression analyses were used to determine predictors of anaemia.

RESULTS

Overall, 42.6% of children in the study displayed anaemia. Children aged 6 to 11 months had the highest anaemia prevalence (53.6%). Anaemia risk factors differed among age-groups and throughout the overall sample. Bivariate and multivariable regression results showed that continued breastfeeding, any history of formula feeding, and consumption of iron-rich or iron-fortified foods were prominent risk factors for anaemia. However, continued breastfeeding and any history of formula feeding had the greatest impact across age-groups (both P<0.05).

CONCLUSION

Anaemia remains a severe public health problem among children aged 6 to 23 months in rural China. Healthy feeding practices, nutritional health knowledge, and nutrition improvement projects are needed to reduce the burden of anaemia among children in rural areas of China.

Outcomes Specific to Spinal Metastases with Paraspinal Disease Extension Following Spine Stereotactic Body Radiotherapy

PURPOSE/OBJECTIVE(S)

Spinal metastases with paraspinal disease (PD) extension are known to have worse outcomes following stereotactic body radiotherapy (SBRT). Characteristics of the PD itself have not been investigated to determine the impact on outcomes such as local control, which is the purpose of this study.

MATERIALS/METHODS

We retrospectively reviewed those patients who had SBRT for spinal metastases with PD disease, identified from a prospectively maintained database. Spinal metastases previously irradiated or surgical resected were excluded. The extent of PD was classified as involving the rib, neuroforamina, and muscle invasion. The gross tumor volume of PD (GTV_PD) and the clinical target volume of PD (CTV_PD) were segregated from the bony compartments based on the treatment plan contours. The outcomes of interest included the cumulative risk of local failure (LF), re-irradiation rates (ReRT), and overall survival (OS). LF and ReRT were estimated for each treated sites using the competing risk model (death as the competing risk), while OS was evaluated per patient using the Kaplan Meier method.

RESULTS

A total of 86 patients with 96 spinal metastases sites with PD were included. Of the 96 treated sites, 65% (62/96), 29% (28/96) and 6% (6/96) of PD spanned 1, 2, and 3 vertebral levels respectively. The median follow-up was 12.4months (range: 0.6-100months). The 6- and 12-month OS for the cohort was 81% and 51%, respectively. 33/86 (38%) patients had radioresistant cancer (gastrointestinal, renal cell carcinoma, thyroid, sarcoma, or melanoma). Involvement of rib, neuroforamina and muscle invasion were observed in 39% (37/96), 65% (62/96) and 21% (20/96) of the treated sites, respectively. Epidural disease was present in 57% (55/96) of treated sites. The median GTV_PD volume was 7cc (range: 0.3-114cc), and the median CTV_PD volume was 24cc (range: 0.4-248cc). The prescribed doses were 24 Gy/2 fractions (fx) (80%), 28 Gy/2 fx (10%) and 30 Gy/4 fx (10%). There were 84 treated sites with at least one post-treatment MRI available for LF assessment. The crude LF risk was 32% (27/84), and the 6- and 12-month cumulative LF rates were 12% and 28%, respectively. There was a trend towards an increased risk of LF when PD involved the rib (35% vs 24% at 1 year respectively, P = 0.07) and muscle (67% vs 20% at 1 year respectively; P = 0.06), but no difference in LF for neuroforamina involvement (26% vs 34% at 1 year respectively, P = 0.5). There were no differences in LF based on cancer radioresistance (P = 0.6), GTV_PD volume (P = 0.3) or CTV_PD volume (P = 0.4). Of the 96 treated sites, 14% (14/96) were re-irradiated (9 with repeat SBRT and 5 with conventional EBRT) at a median of 15 months (range: 4.7-59 months) post initial SBRT. The cumulative incidence of ReRT at 6- and 12-months were 1.2% and 7.3%, respectively.

CONCLUSION

PD involving adjacent rib and muscle may be associated with worse LF following SBRT. Further expansion of the cohort and dosimetric analyses are ongoing.

Stereotactic Body Radiotherapy for Posterior Element Only Spinal Metastases: Outcomes and Validation of Recommended Clinical Target Volume Delineation Practice

PURPOSE/OBJECTIVE(S)

Spine stereotactic body radiotherapy (SBRT) results in improved local control and pain response compared to conventional external beam radiotherapy. Consensus stipulates MRI-based delineation of the clinical target volume (CTV) is critical and is based on spine segment sector involvement. The applicability of these contouring guidelines to metastases confined to the posterior elements is unknown. The purpose of this study was to determine the patterns of failure, as well as the safety of treating posterior element metastases when the vertebral body was intentionally excluded from the CTV.

MATERIALS/METHODS

A retrospective review of a prospectively maintained database of 605 patients and 1412 spine segments treated with spine SBRT was performed. Only treated segments involving the posterior elements alone were included for the analyses. The primary outcome was local failure, as per SPINO recommendations, and secondary outcomes included patterns of failure, toxicities. Clinical and tumor factors were reported with descriptive statistics. The cumulative risk of local failure was estimated using the Fine-Gray method, accounting for death before local failure as a competing risk.

RESULTS

A total of 24/605 patients and 31/1412 segments within the database were treated to the posterior elements only. Local failure occurred in 11/31 segments. The cumulative rate of local recurrence was 9.7% at 12 months and 30.8% at 24 months. Amongst local failures, the most common histologies were renal cell carcinoma (36.4%) and non-small cell lung cancer (36.4%). At baseline, 4/11 (36.4%) segments with local failure (36.4%) had epidural disease and 8/11 (72.7%) had paraspinal disease. Most local failures were treated in the de novo setting (8/11, 72.7%). 6/11 (54.5%) failed exclusively within treated CTV sectors and 5/11 (45.5%) with both treated and adjacent untreated sectors. Of these five, four had disease progression within the untreated vertebral body. No failures occurred exclusively within the untreated vertebral body. One patient (4.2%) experienced a grade 4 skin toxicity and one patient (4.2%) developed an iatrogenic Grade 1 vertebral compression fracture.

CONCLUSION

Posterior element alone metastases are rare. Our analyses support SBRT consensus contouring guidelines such that the vertebral body can be excluded from CTV in spinal metastases confined to the posterior elements.

A photo-controlled, all-solid, and frequency-tunable ultra-wideband pulse generator

With the continuous exploration of the bioelectric effect, nanosecond and picosecond pulsed electric fields used in cancer therapy and drug introduction have attracted great attention. In this paper, an ultrashort pulsed electric field generator is proposed, which connects two photoconductive semiconductor switches in parallel to generate unipolar and bipolar pulses. We described the experimental scheme of the generator and the simulation of the radio frequency combiner. A 532 nm laser with pulse widths of 1 ns and 500 ps is used to trigger the photoconductive semiconductor switches. The experimental results show that the scheme can achieve adjustments of 357 and 720 MHz for the center frequency and the 3 dB bandwidth, respectively. The results confirm that this proposed scheme can be used for unipolar/bipolar frequency-adjustable ultra-wideband pulse generation.

Staged Stereotactic Radiosurgery as a Novel Adaptive Approach to Salvage Previously Irradiated Brain Metastases

PURPOSE/OBJECTIVE(S)

We report outcomes specific to a novel 3 fraction (frx) staged stereotactic radiosurgery (St-SRS) regimen designed to salvage metastases previously irradiated and considered to be at high risk of radiation necrosis (RN).

MATERIALS/METHODS

A total of 24 patients with 55 metastases treated with our 3 frx St-SRS approach were reviewed. Prior to each frx, patients were re-simulated and planned with a new MRI to allow for treatment adaption. The primary endpoint was the cumulative incidence of local failure (LF) and secondary endpoints included tumor dynamics and RN rates.

RESULTS

The median follow up was 9.0 months (range: 2.7-40.1 months) and median age was 59-years (range: 32-84). Primary cancers were of breast (44%), lung (33%), melanoma (22%), and gastro-intestinal (1%) origin. Individual metastases treated with St-SRS had initially failed surgery and post-op cavity hypofractionated SRS (HSRS) for 2/55 (4%), SRS alone for 19/55 (34%), whole brain radiation (WBRT) alone for 6/55 (11%), HSRS for 2/55 (4%), and prior SRS and WBRT exposure for 28/55 (51%). 46/55 (84%) were prescribed 8 Gy, 8 Gy, 4 Gy; 8/55 (14%) had 6 Gy, 6 Gy, 4 Gy and 1/55 (2%) had 8 Gy, 8 Gy, 6 Gy. The median number of weeks between frx was 2.6 (range: 1.0-6.8). The median of the mean and maximum target doses were 9.7 Gy (range: 5.4-11.7 Gy) and 12.4 Gy (range, 7.5-16.0 Gy) respectively. The median prescription isodose line was 62% (range: 50-85%). The mean lesion volume and diameter was 3.8cc (range: 0.05-24.8cc) and 1.6cm (range: 0.2-4.4cm), respectively. The mean percent target volume coverage, Paddick Conformality Index and Gradient Index were 100% (range: 97-100%), 0.7 (range: 0.1-0.9), and 3.2 (range: 2.5-6.7), respectively. The mean volume change between staged frxs was -4.2% (range: -69.3 to +63.1%), and based on the first and last St-SRS MRI was -10.8% (range: -86.6% to +68.7%). The crude LF rate was 27%. The median time to LF was 3.4 months (range: 1.2-7.4 months). Amongst those with a LF, 7/15 (46%) were melanoma, 6/15 (40%) HER2 positive breast cancer, 1/15 (7%) gastrointestinal and 1/15 (7%) non-small cell lung carcinoma. 8/15 (53%) had prior WBRT and SRS exposure, 1/16 (7%) surgery and cavity HSRS, 5/15 (33%) SRS alone and 1/15 (7%) WBRT alone. Only asymptomatic RN events were observed in 4/55 (7%).

CONCLUSION

St-SRS is a promising approach to salvage previously irradiated brain metastases, including prior SRS, with a favorable rate of RN. Tumor volume dynamics between stages can be significant warranting adaptive replanning.

The Incidence and Prognosis Value of Perineural Invasion in Rectal Carcinoma: From Meta-Analyses and Real-World Clinical Pathological Features

AIMS

Perineural invasion (PNI) is a special type of metastasis of several cancers and has been reported as being a factor for poor prognosis in colorectal carcinoma. However, investigations of PNI in only rectal cancer and a comprehensive analysis combining meta-analyses with real-world case studies remain lacking.

MATERIALS AND METHODS

First, articles from 2000 to 2020 concerning the relationship between PNI and rectal cancer prognoses and clinical features were meta-analysed. Subsequently, we carried out a retrospective analysis of 312 rectal cancer cases that underwent radical surgery in the real world. The incidence of PNI and the relationship between PNI and prognosis, as well as clinicopathological factors, were investigated.

RESULTS

The incidence of PNI was 23.09% and 33.01% in the meta-analysis and clinical cases, respectively. PNI occurred as early as stage I (2.94%). Moreover, neoadjuvant therapy significantly reduced the PNI-positive rate (20.34% versus 26.54%). Both meta-analysis and real-world clinical case studies suggested that PNI-positive patients had poorer prognoses than PNI-negative patients. We established an effective risk model consisting of T stage, differentiation and lymphovascular invasion to predict PNI in rectal cancer.

CONCLUSION

PNI is a poor prognostic factor for rectal cancer and could occur even in stage I. Additionally, neoadjuvant therapy could sufficiently reduce the PNI-positive rate. T stage, lymphovascular invasion and differentiation grade were independent risk factors for PNI and the risk model that included these factors could predict the probability of PNI.

Risk factors for bloodstream infection in paediatric haematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Haematopoietic stem cell transplantation (HSCT), a standard treatment for paediatric haematological diseases, is highly associated with bloodstream infection (BSI), which may increase mortality.

AIM

To explore the risk factors for BSI in paediatric HSCT recipients.

METHODS

Three English databases and four Chinese databases were searched from inception to March 17th, 2022. Eligible studies included randomized controlled trials, cohort studies, and case-control studies that enrolled HSCT recipients aged ≤18 years and reported BSI risk factors. Two reviewers independently screened studies, extracted data, and assessed the risk of bias. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE), certainty of body of evidence was assessed.

FINDINGS

Fourteen studies involving 4602 persons were included. The incidences of BSI and associated mortality in paediatric HSCT recipients were approximately 10-50% and 5-15%, respectively. Meta-analysis of all studies revealed that previous BSI before HSCT (relative effect (RE): 2.28; 95% confidence interval (CI) 1.19-4.34, moderate certainty) and receiving an umbilical cord blood transplant (RE: 1.55; 95% CI: 1.22-1.97, moderate certainty) were probably associated with an increased risk of BSI. Meta-analysis of studies with low risk of bias reassured that previous BSI before HSCT probably increased the risk of BSI (RE: 2.28; 95% CI: 1.19-4.34, moderate certainty), and revealed that steroid use (RE: 2.72; 95% CI: 1.31-5.64, moderate certainty) was likely a risk factor whereas autologous HSCT was probably a protective factor of BSI (RE: 0.65; 95% CI: 0.45-0.94, moderate certainty).

CONCLUSION

These findings could inform the management of paediatric HSCT recipients, helping identify who may benefit from prophylactic antibiotics.

[Results analysis of mNGS applied to infectious diseases]

The application of metagenomic second-generation sequencing (mNGS) is shifting from research to clinical laboratories due to rapid technological advances and significant cost reductions. Although many studies and case reports have confirmed that the success of mNGS in improving the prevention, diagnosis, treatment and tracking of infectious diseases, there are still some obstacles that must be overcome. The results of mNGS show all the possible pathogens in the sample, however, in the face of thousands of microbes that can infect humans, it remains challenging to accurately identify the key pathogens. So far, there is no unified interpretation standard for mNGS in clinical practice. This article reviews the interpretation of mNGS results for pathogen infection in different systems, the clinical interpretation and application regulations of mNGS results, and the challenges of mNGS interpretation in pathogen diagnosis.

A novel Doppler backscattering (DBS) system to simultaneously measure radio frequency plasma fluctuations and low frequency turbulence

A novel quadrature Doppler Backscattering (DBS) system has been developed and optimized for the E-band (60-90 GHz) frequency range using either O-mode or X-mode polarization in DIII-D plasmas. In general, DBS measures the amplitude of density fluctuations and their velocity in the lab frame. The system can simultaneously monitor both low-frequency turbulence (f < 10 MHz) and radiofrequency plasma density fluctuations over a selectable frequency range (20-500 MHz). Detection of high-frequency fluctuations has been demonstrated for low harmonics of the ion cyclotron frequency (e.g., 2fci ∼ 23 MHz) and externally driven high-frequency helicon waves (f = 476 MHz) using an adjustable frequency down conversion system. Importantly, this extends the application of DBS to a high-frequency spectral domain while maintaining important turbulence and flow measurement capabilities. This unique system has low phase noise, good temporal resolution (sub-millisecond), and excellent wavenumber coverage (kθ ∼ 1-20 cm-1 and kr ≲ 30 cm-1). As a demonstration, localized internal DIII-D plasma measurements are presented from turbulence (f ≤ 5 MHz), Alfvenic waves (f ∼ 6.5 MHz), ion cyclotron waves (f ≥ 20 MHz), as well as fluctuations around 476 MHz driven by an external high-power 476 MHz helicon wave antenna. In the future, helicon measurements will be used to validate GENRAY and AORSA modeling tools for prediction of helicon wave propagation, absorption, and current drive location for the newly installed helicon current drive system on DIII-D.

CO-INFECTING PHAGES IMPEDE EACH OTHER'S ENTRY INTO THE CELL

Bacteriophage lambda tunes its propensity to lysogenize based on the number of viral genome copies inside the infected cell. Viral self-counting is believed to serve as a way of inferring the abundance of available hosts in the environment. This interpretation is premised on an accurate mapping between the extracellular phage-to-bacteria ratio and the intracellular multiplicity of infection (MOI). However, here we show this premise to be untrue. By simultaneously labeling phage capsids and genomes, we find that, while the number of phages landing on each cell reliably samples the population ratio, the number of phages entering the cell does not. Single-cell infections, followed in a microfluidic device and interpreted using a stochastic model, reveal that the probability and rate of individual phage entries decrease with MOI. This decrease reflects an MOI-dependent perturbation to host physiology caused by phage landing, evidenced by compromised membrane integrity and loss of membrane potential. The dependence of phage entry dynamics on the surrounding medium is found to result in a strong impact of environmental conditions on the infection outcome, while the protracted entry of co-infecting phages increases the cell-to-cell variability in infection outcome at a given MOI. Our findings demonstrate the previously unappreciated role played by entry dynamics in determining the outcome of bacteriophage infection.

Targeting the post-synaptic proteome has therapeutic potential for psychosis in Alzheimer Disease

Individuals with Alzheimer Disease who develop psychotic symptoms (AD + P) experience more rapid cognitive decline and have reduced indices of synaptic integrity relative to those without psychosis (AD-P). We sought to determine whether the postsynaptic density (PSD) proteome is altered in AD + P relative to AD-P, analyzing PSDs from dorsolateral prefrontal cortex of AD + P, AD-P, and a reference group of cognitively normal elderly subjects. The PSD proteome of AD + P showed a global shift towards lower levels of all proteins relative to AD-P, enriched for kinases, proteins regulating Rho GTPases, and other regulators of the actin cytoskeleton. We computationally identified potential novel therapies predicted to reverse the PSD protein signature of AD + P. Five days of administration of one of these drugs, the C-C Motif Chemokine Receptor 5 inhibitor, maraviroc, led to a net reversal of the PSD protein signature in adult mice, nominating it as a novel potential treatment for AD + P.

Comparative effectiveness and safety of antibiotic prophylaxis during induction chemotherapy in children with acute leukaemia: a systematic review and meta-analysis

BACKGROUND

Bacterial infections are common during induction therapy in children and adolescents with acute leukaemia and may cause infection-related mortality.

AIM

To determine the efficacy and safety of prophylactic antibiotics in paediatric patients with acute leukaemia receiving induction chemotherapy.

METHODS

From three English databases and four Chinese databases, we searched for randomized controlled trials (RCTs) and cohort studies that compared prophylactic antibiotics to placebo, no prophylaxis, or that compared one antibiotic versus another in paediatric patients with acute leukaemia undergoing induction chemotherapy. Two reviewers independently screened the studies, extracted data, and assessed the risk of bias using Cochrane Risk of Bias 2 tool and Newcastle-Ottawa Scale, and the certainty of evidence using Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

FINDINGS

Two RCTs and ten cohort studies were finally included. For children with acute lymphoblastic leukaemia, antibiotic prophylaxis, including levofloxacin, sulfamethoxazole-trimethoprim, or other antibiotics, probably reduced bacteraemia (risk ratio (RR): 0.44; 95% confidence interval (CI): 0.33-0.60; moderate certainty) without significantly increasing Clostridioides difficile infection (CDI) or invasive fungal infection. Levofloxacin reduced the CDI rate (RR: 0.08; 95% CI: 0.01-0.62; high certainty). Ciprofloxacin prophylaxis probably reduced infection-related mortality (RR: 0.12; 95% CI: 0.01-0.97; moderate certainty). In children with acute myeloid leukaemia, ciprofloxacin plus vancomycin may reduce febrile neutropenia (RR: 0.79; 95% CI: 0.66-0.94; low certainty). Individual studies indicated that prophylaxis increased antibiotic exposure but reduced non-preventive antibiotic exposure.

CONCLUSION

In children with acute leukaemia undergoing induction therapy, antibiotic prophylaxis may improve the bacterial infection and mortality.