[Clinical efficacy of intraarticular vancomycin in preventing early periprosthetic joint infection after primary knee arthroplasty]

Objective: To investigate the clinical effect of intraarticular vancomycin on early periprosthetic joint infection (PJI) in knee arthroplasty and the incidence of postoperative complications. Methods: This is a retrospective cohort study. The clinical data of 1 867 patients who underwent primary knee arthroplasty at Department of Joint Surgery, the Affiliated Hospital of Qingdao University from April 2022 to June 2023 were retrospectively analysed, including total knee arthroplasty (TKA), robotic-assisted total knee arthroplasty (RA-TKA) and unicondylar knee arthroplasty (UKA). There were 687 males and 1180 females, aged (68.0±11.2)years(range:45 to 87 years). Patients were divided into the vancomycin group and the control group according to whether or not intra-articular injection of 1 g of vancomycin powder dissolved in 30 ml of saline was performed after intraoperative joint capsule closure. In the vancomycin group, 925 patients were included, including 782 TKA, 27 RA-TKA and 116 UKA.In the control group, 942 patients were included, including 767 TKA, 99 RA-TKA and 76 UKA. Early PJI, wound complications, and vancomycin-related toxicity including acute renal collapse, ototoxicity, and allergic reactions were assessed within 3 months postoperatively. Results: No PJI was found in all patients in the vancomycin group.Five cases (0.7%,5/767) of early PJI were found in TKA patients in the control group, with a statistically significant difference (P=0.030); 1 case of early PJI was found in each RA-TKA and UKA patients, with non-significant difference compared with vancomycin group (all P>0.05). Two cases (0.3%,2/782) of incisional complications were found in TKA patients in the vancomycin group, and 4 cases (0.5%, 4/767) of incisional complications were found in TKA patients in the control group, with non-significant difference(P=0.449); no incisional complications were found in RA-TKA patients in the vancomycin group, and 1 case (1.0%,1/99) of incisional complications were found in RA-TKA patients in the control group, the difference was not statistically significant (P>0.05); no incisional complications were found in both groups of UKA patients.No vancomycin-related acute kidney injury, ototoxicity, or allergic reactions was observed in all patients. Conclusion: Intra-articular injection of 1 g of vancomycin suspension after arthrotomy closure during TKA maybe lower the risk of early PJI without increasing the risk of wound complication and vancomycin-associated systemic toxicity.

α-Mangostin suppresses ethanol-induced gastric ulceration by regulating the Nrf2/HO-1 and NF-κB/NLRP3/caspase-1 signaling pathways and gut microbiota

α-Mangostin is a natural xanthone derivative isolated from Camellia atrophy (CA), commonly known as Lichuan black tea (LBT). The present study investigated the ameliorating effect and mechanism of α-mangostin on alcoholic gastric ulcers (GU) in rats. In vivo, α-mangostin relieved pathological symptoms. Moreover, α-mangostin regulated the activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase 1 (HO-1) and nuclear factor κB (NF-κB)/NLR family pyrin domain containing 3 (NLRP3)/caspase-1 pathways. Reactive oxygen species (ROS), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) were significantly decreased and IL-10 were increased, the microtubule-associated protein light chain 3 (LC3)-II/LC3-I ratio was increased, p62 protein expression was decreased, and inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) protein expression was down-regulated. The relevant mechanisms were validated using GSE-1 and RAW264.7 cells in an in vitro model. Furthermore, α-mangostin increased Ligilactobacillus and Muribaculum abundance as well as propionic acid and butyric acid contents. Therefore, α-mangostin possesses antioxidant and anti-inflammatory properties, and remodels intestinal flora dysbiosis through mechanisms that may involve regulation of the Nrf2/HO-1 pathway and NF-κB/NLRP3/caspase-1 pathway. It also increases propionic acid and butyric acid contents. This study provides novel evidence regarding the use of α-mangostin for treating GU.

Hugan Qingzhi tablets attenuates endoplasmic reticulum stress in nonalcoholic fatty liver disease rats by regulating PERK and ATF6 pathways

BACKGROUND

Endoplasmic reticulum (ER) stress, promoting lipid metabolism disorders and steatohepatitis, contributes significantly to the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Hugan Qingzhi tablets (HQT) has a definite effect in the clinical treatment of NAFLD patients, but its mechanism is still unclear. This study aims to investigate the effects of HQT on ER stress in the liver tissues of NAFLD rats and explore the underlying mechanism.

METHODS

The NAFLD rat model was managed with high-fat diet (HFD) for 12weeks. HQT was administrated in a daily basis to the HFD groups. Biochemical markers, pro-inflammatory cytokines, liver histology were assayed to evaluate HQT effects in HFD-induced NAFLD rats. Furthermore, the expression of ER stress-related signal molecules including glucose regulating protein 78 (GRP78), protein kinase RNA-like endoplasmic reticulum kinase (PERK), p-PERK, eukaryotic translation initiation factor 2α (EIF2α), p-EIF2α, activating transcription factor 4 (ATF4), acetyl-coenzyme A-carboxylase (ACC), activating transcription factor (ATF6), and nuclear factor-kappa B-p65 (NF-κB-p65) were detected by western blot and/or qRT-PCR.

RESULTS

The histopathological characteristics and biochemical data indicated that HQT exhibited protective effects on HFD-induced NAFLD rats. Furthermore, it caused significant reduction in the expression of ERS markers, such as GRP78, PERK, p-PERK, and ATF6, and subsequently downregulated the expression of EIF2α, p-EIF2α ATF4, ACC, and NF-κB-p65.

CONCLUSIONS

The results suggested that HQT has protective effect against hepatic steatosis and inflammation in NAFLD rats by attenuating ER stress, and the potential mechanism is through inhibition of PERK and ATF6 pathways.

Isoliquiritigenin suppresses the progression of malignant melanoma via targeting H2A.Z.1-E2F1 pathway

Cutaneous melanoma is one of the most prevalent tumors, and it is still a huge challenge in the current clinical treatment. Isoliquiritigenin (ISL), which is isolated from Glycyrrhiza uralensis Fisch., has been reported for its anti-tumor effect. However, the underlying mechanism and targets of ISL are still not be revealed clearly. In this study, differentiallyexpressedproteins were identified bylabel-free quantitative mass spectrometry. Two isoforms of the histone variant H2A.Z, including H2A.Z.1 and H2A.Z.2, were significantly down regulated after administration of ISL in melanoma. H2A.Z.1 was highly expressed in melanoma and correlated with poor prognosis of melanoma. The expression of H2A.Z was inhibited by ISL in a concentration-dependent manner. Overexpression of H2A.Z.1 in melanoma cell lines partly restored the repressed cell proliferation and cell cycle by ISL. Moreover, E2F1 was identified as one downstream target of H2A.Z.1, which was also highly expressed in melanoma and correlated with poor prognosis of melanoma. Furthermore, in vivo assays validated the inhibitory role of ISL in melanoma proliferation and the expression of H2A.Z.1 and E2F1.Aboveall,it is indicated that ISL inhibit melanoma proliferation via targeting H2A.Z.1-E2F1 pathway. These findings explain the anti-tumor mechanism of ISL and provide potential therapeutic targets for melanoma.

[Radiomics-based prediction of microsatellite instability in stage Ⅱ and Ⅲ rectal cancer patients based on T2WI MRI and diffusion-weighted imaging]

Objective: To examine the radiomics model based on high-resolution T2WI and diffusion weighted imaging (DWI) in predicting microsatellite stability in patients with stage Ⅱ and Ⅲ rectal cancer. Methods: From February 2016 to October 2020, 175 patients with stage Ⅱ and Ⅲ rectal cancer who met the inclusion criteria were retrospectively collected. There were 119 males and 56 females, aged (63.9±9.4) years (range: 37 to 85 years), including 152 patients with microsatellite stability and 23 patients with microsatellite instability. All patients were randomly divided into the training group (n=123) and the validation group (n=52) with a ratio of 7∶3. The region of interest was labeled on the T2WI and DWI images of each patient using the ITK-SNAP software, and PyRadiomics was used to extract seven kinds of radiomics features. After removing redundant features and normalizing features, the least absolute shrinkage and selection operation were used for feature selection. One clinical model, three radiomics models and one clinical-radiomics model were constructed in the training group based on a support vector machine. The area under receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy were used to evaluate the performance of the models in the verification group. Results: Three clinical features (age, degree of tumor differentiation, and distance from the lower edge of the tumor to the anal edge) and six radiomics features (two DWI-related features and four T2WI-related features) most related to microsatellite status of rectal cancer patients were selected. The AUC of the clinical-radiomics model in the training group was 0.95. In the validation group, the AUC was 0.81, better than the clinical model (0.68, Z=0.71, P=0.04), and equivalent to the T2WI+DWI model (0.82, Z=0.21, P=0.83). Conclusions: Radiomic features based on preoperative T2WI and DWI were related to microsatellite stability in patients with stage Ⅱ and Ⅲ rectal cancer and showed a high classification efficiency. The model based on the features provided a noninvasive and convenient tool for preoperative determination of microsatellite stability in rectal cancer patients.

Increased Dietary Niacin Intake Improves Muscle Strength, Quality, and Glucose Homeostasis in Adults over 40 Years of Age

BACKGROUND AND AIMS

Age-related loss of skeletal muscle mass and strength begins at 40 years of age, and limited evidence suggests that niacin supplementation increases levels of nicotinamide adenine dinucleotide in mouse muscle tissue. In addition, skeletal muscle has a key role in the body's processing of glucose. Therefore, this study aimed to investigate the relationship between dietary niacin and skeletal muscle mass, strength, and glucose homeostasis in people aged 40 years and older.

METHODS

This study was an American population-based cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES). Considering that some outcomes are only measured in specific survey cycles and subsamples, we established three data sets: a grip strength dataset (2011-2014, n=3772), a body mass components dataset (2011-2018, n=3279), and a glucose homeostasis dataset (1999-2018, n=9189). Dietary niacin and covariates were measured in all survey cycles. Linear regression or logistic regression models that adjusted for several main covariates, such as physical activity and diet, was used to evaluate the relationship between dietary niacin and grip strength, total lean mass, appendicular lean mass, total fat, trunk fat, total bone mineral content, homeostasis model assessment of insulin resistance (HOMA-IR), fasting blood glycose, fasting insulin and sarcopenia risk. Subgroup analyses, a trend test, an interaction test, and a restricted cubic spline were used for further exploration.

RESULTS

Higher dietary niacin intake was significantly correlated with higher grip strength (β 0.275, 95% confidence intervals [CI] 0.192-0.357), higher total lean mass (β 0.060, 95% CI 0.045-0.074), higher appendicular lean mass (β 0.025, 95% CI 0.018-0.033), and higher total bone mineral content (β 0.005, 95% CI 0.004-0.007). By contrast, higher dietary niacin intake was significantly associated with lower total fat (β -0.061, 95% CI -0.076 to -0.046), lower trunk fat (β -0.041, 95% CI -0.050 to -0.032) and lower sarcopenia risk (OR 0.460, 95% CI 0.233 to 0.907). In addition, dietary niacin significantly reduced HOMA-IR, fasting blood glucose (in participants without diabetes), and fasting insulin (p <0.05).

CONCLUSION

Niacin is associated with improved body composition (characterized by increased muscle mass and decreased fat content) and improved glucose homeostasis in dietary doses. Dietary niacin supplementation is a feasible way to alleviate age-related muscular loss.

Late-Night Overeating and All-Cause and Cardiovascular Disease Mortality in Adults Aged ≥ 50: A Cohort Study

BACKGROUND

Late-night overeating (LNOE) is closely associated with many health risk factors, but whether LNOE can increase the risk of death remains unknown. Thus, the prospective cohort study aimed to investigate the relationship between LNOE and mortality using data from the National Health and Nutrition Examination Survey.

METHODS

11,893 participants aged 50 years and older were included in the study. Dietary information was obtained through 24-h dietary recall interviews. Cox regression, subgroup, sensitivity, and restricted cubic spline analyses were used to assess the association between LNOE and mortality.

RESULTS

During a median follow-up of 8.3 years, 2,498 deaths occurred. After adjusting for major confounders, compared to the non-late-night eating (NLNE) group, the LNOE group was associated with higher risks of all-cause (HR = 1.47, 95% CI = 1.06-2.04) and cardiovascular disease (CVD) mortality (HR = 2.02, 95% CI = 1.13-3.60). No significant association was found between late-night eating (LNE) and mortality. Subgroup analyses showed that the LNOE group had a greater risk of all-cause and CVD mortality in participants older than 70 years, with alcohol consumption and hypertension and demonstrated an increased risk of all-cause mortality in males and higher CVD mortality in females.

CONCLUSION

The habit of LNOE was an independent risk factor for all-cause and CVD mortality in US adults aged 50 years and older, which was also influenced by age, sex, alcohol consumption, and hypertension.

Learning Curve for Flow Diversion of Posterior Circulation Aneurysms: A Long-Term International Multicenter Cohort Study

BACKGROUND AND PURPOSE

Flow diversion has gradually become a standard treatment for intracranial aneurysms of the anterior circulation. Recently, the off-label use of the flow diverters to treat posterior circulation aneurysms has also increased despite initial concerns of rupture and the suboptimal results. This study aimed to explore the change in complication rates and treatment outcomes across time for posterior circulation aneurysms treated using flow diversion and to further evaluate the mechanisms and variables that could potentially explain the change and outcomes.

MATERIALS AND METHODS

A retrospective review using a standardized data set at multiple international academic institutions was performed to identify patients with ruptured and unruptured posterior circulation aneurysms treated with flow diversion during a decade spanning January 2011 to January 2020. This period was then categorized into 4 intervals.

RESULTS

A total of 378 procedures were performed during the study period. Across time, there was an increasing tendency to treat more vertebral artery and fewer large vertebrobasilar aneurysms (P = .05). Moreover, interventionalists have been increasingly using fewer overlapping flow diverters per aneurysm (P = .07). There was a trend toward a decrease in the rate of thromboembolic complications from 15.8% in 2011-13 to 8.9% in 2018-19 (P = .34).

CONCLUSIONS

This multicenter experience revealed a trend toward treating fewer basilar aneurysms, smaller aneurysms, and increased usage of a single flow diverter, leading to a decrease in the rate of thromboembolic and hemorrhagic complications.

Alisol B 23-Acetate Ameliorates Lipopolysaccharide-Induced Intestinal Barrier Dysfunction by Inhibiting TLR4-NOX1/ROS Signaling Pathway in Caco-2 Cells

Alisol B 23-Acetate (AB23A) is a naturally occurring triterpenoid, which can be indicated in the rhizome of medicinal and dietary plants from Alisma species. Previous studies have demonstrated that AB23A could inhibit intestinal permeability by regulating tight junction (TJ)-related proteins. Even so, the AB23A protective mechanism against intestinal barrier dysfunction remains poorly understood. This investigation seeks to evaluate the AB23A protective effects on intestinal barrier dysfunction and determine the mechanisms for restoring intestinal barrier dysfunction in LPS-stimulated Caco-2 monolayers. According to our findings, AB23A attenuated the inflammation by reducing pro-inflammatory cytokines production like IL-6, TNF-α, IL-1β, and prevented the paracellular permeability by inhibiting the disruption of TJ in LPS-induced Caco-2 monolayers after treated with LPS. AB23A also inhibited LPS-induced TLR4, NOX1 overexpression and subsequent ROS generation in Caco-2 monolayers. Transfected with NOX1-specific shRNA diminished the up-regulating AB23A effect on ZO-1 and occludin expression. Moreover, transfected with shRNA of TLR4 not only enhanced ZO-1 and occludin expression but attenuated NOX1 expression and ROS generation. Therefore, AB23A ameliorates LPS-induced intestinal barrier dysfunction by inhibiting TLR4-NOX1/ROS signaling pathway in Caco-2 monolayers, suggesting that AB23A may have positive impact on maintaining the intestinal barrier’s integrity.

The probiotic effects of AB23A on high-fat-diet-induced non-alcoholic fatty liver disease in mice may be associated with suppressing the serum levels of lipopolysaccharides and branched-chain amino acids

Alisol B 23-acetate (AB23A) is a natural triterpenoid isolated from Rhizoma alisamatis that has been widely used as a traditional Chinese medicine (TCM). Previous studies have documented the beneficial effect of AB23A on non-alcoholic fatty liver disease (NAFLD), but the functional interactions between gut microbiota and the anti-NAFLD effect of AB23A remain unclear. In this study, we investigated the benefits of experimental treatment with AB23A on gut microbiota dysbiosis in NAFLD with an obesity model. C57BL/6J mice were administrated a high-fat diet (HFD) with or without AB23A for 12 weeks. AB23A significantly improved metabolic phenotype in the HFD-fed mice. Moreover, results of 16S rRNA gene-based amplicon sequencing in each group reveled that AB23A not only reduced the abundance of the Firmicutes/Bacteroidaeota ratio and Actinobacteriota/Bacteroidaeota ratio, but regulated the abundance of the top 10 genera, including norank_f__Muribaculaceae, Lactobacillus, Ileibacterium, Turicibacter, Faecalibaculum, the Lachnospiraceae_NK4A136_group, unclassified_f__Lachnospiraceae, and norank_f__Lachnospiraceae. AB23A significantly reduced the serum levels of lipopolysaccharide and branched-chain amino acids, which are positively correlated with the abundances of Ileibacterium and Turicibacter. Moreover, AB23A led to remarkable reductions in the activation of TLR4, NF-κB, and mTOR, and upregulated the expression of tight junction proteins, including ZO-1 and occludin. These results revealed that AB23A displayed a prebiotic capacity in HFD-fed NAFLD mice.

New Prognostic Biomarkers and Drug Targets for Skin Cutaneous Melanoma via Comprehensive Bioinformatic Analysis and Validation

Skin cutaneous melanoma (SKCM) is the most aggressive and fatal type of skin cancer. Its highly heterogeneous features make personalized treatments difficult, so there is an urgent need to identify markers for early diagnosis and therapy. Detailed profiles are useful for assessing malignancy potential and treatment in various cancers. In this study, we constructed a co-expression module using expression data for cutaneous melanoma. A weighted gene co-expression network analysis was used to discover a co-expression gene module for the pathogenesis of this disease, followed by a comprehensive bioinformatics analysis of selected hub genes. A connectivity map (CMap) was used to predict drugs for the treatment of SKCM based on hub genes, and immunohistochemical (IHC) staining was performed to validate the protein levels. After discovering a co-expression gene module for the pathogenesis of this disease, we combined GWAS validation and DEG analysis to identify 10 hub genes in the most relevant module. Survival curves indicated that eight hub genes were significantly and negatively associated with overall survival. A total of eight hub genes were positively correlated with SKCM tumor purity, and 10 hub genes were negatively correlated with the infiltration level of CD4+ T cells and B cells. Methylation levels of seven hub genes in stage 2 SKCM were significantly lower than those in stage 3. We also analyzed the isomer expression levels of 10 hub genes to explore the therapeutic target value of 10 hub genes in terms of alternative splicing (AS). All 10 hub genes had mutations in skin tissue. Furthermore, CMap analysis identified cefamandole, ursolic acid, podophyllotoxin, and Gly-His-Lys as four targeted therapy drugs that may be effective treatments for SKCM. Finally, IHC staining results showed that all 10 molecules were highly expressed in melanoma specimens compared to normal samples. These findings provide new insights into SKCM pathogenesis based on multi-omics profiles of key prognostic biomarkers and drug targets. GPR143 and SLC45A2 may serve as drug targets for immunotherapy and prognostic biomarkers for SKCM. This study identified four drugs with significant potential in treating SKCM patients.

[Diagnostic value of platelet associated biomarkers in chronic periprosthetic joint infection]

Objective: To evaluate the diagnostic value of platelet count(PC),PC to mean platelet volume(MPV) ratio(PC/MPV) and plateletcrit(PCT) in chronic periprosthetic joint infection(PJI). Method: The medical records of 159 patients who underwent hip or knee revisions at Department of Joint Surgery,Affiliated Hospital of Qingdao University from August 2013 to June 2019 were retrospectively reviewed. There were 51 patients(26 knees and 25 hips) in the PJI group,which included 28 males and 23 females,aged (68.0±11.8)years (range:32 to 84 years)with a body mass index(BMI)of (26.1±3.6) kg/m².There were 116 patients(19 knees and 97 hips) in the aseptic loosening(AL) group,including 67 males and 49 females,aged (70.3±8.9)years(range:49 to 89 years)with a BMI of (25.0±3.6)kg/m².The plasma C-reactive protein(CRP),erythrocyte sedimentation rate(ESR),PC,MPV,PC/MPV and PCT levels of the two groups were recorded and analyzed. Receiver operating characteristic curve was used to calculate the sensitivity and specificity of each biomarker,expect for MPV,and the diagnostic value of each biomarker was compared according to the area under the curve(AUC).Independent-sample t test or Mann-Whitney U test were used for comparison between groups. Result: Compared with AL group,AJI group had significantly higher levels of CRP,ESR,PC,PC/MPV and PCT(all P<0.05),but lower level of MPV (P<0.05).The AUCs for CRP,ESR,PC,PC/MPV and PCT were 0.820, 0.829, 0.689, 0.668 and 0.676,respectively. Based on the Youden index,the optimal predictive cutoff for CRP was 11.12 mg/L,with a sensitivity of 74.4% and a specificity of 87.1%.The optimal predictive cutoff for ESR was 17.60 mm/1 h,with a sensitivity of 81.4% and a specificity of 75.3%.The optimal predictive cutoff for PC was 243.00×109/L,with a sensitivity of 60.6% and a specificity of 71.8%.The optimal predictive cutoff for PC/MPV was 24.95,the sensitivity was 58.1% and the specificity was 74.1%.And the optimal predictive cutoff for PCT was 0.24%,with a sensitivity of 69.8% and a specificity of 63.5%. Conclusion: PC,PC to MPV ratio and PCT were of limited value to diagnose PJI.

SIRT6 Promotes Osteogenic Differentiation of Adipose-Derived Mesenchymal Stem Cells Through Antagonizing DNMT1

Background

Adipose-derived stem cells (ADSCs) are increasingly used in regenerative medicine because of their potential to differentiate into multiple cell types, including osteogenic lineages. Sirtuin protein 6 (SIRT6) is a nicotinamide adenine dinucleotide (NAD)-dependent deacetylase that plays important roles in cell differentiation. NOTCH signaling has also been reported to involve in osteogenic differentiation. However, the function of SIRT6 in osteogenic differentiation of ADSCs and its relation to the NOTCH signaling pathways are yet to be explored.

Methods

The in vitro study with human ADSCs (hADSCs) and in vivo experiments with nude mice have been performed. Alkaline phosphatase (ALP) assays and ALP staining were used to detect osteogenic activity. Alizarin Red staining was performed to detect calcium deposition induced by osteogenic differentiation of ADSCs. Western blot, RT-qPCR, luciferase reporter assay, and co-immunoprecipitation assay were applied to explore the relationship between of SIRT6, DNA methyltransferases (DNMTs) and NOTCHs.

Results

SIRT6 promoted ALP activity, enhanced mineralization and upregulated expression of osteogenic-related genes of hADSCs in vitro and in vivo. Further mechanistic studies showed that SIRT6 deacetylated DNMT1, leading to its unstability at protein level. The decreased expression of DNMT1 prevented the abnormal DNA methylation of NOTCH1 and NOTCH2, resulting in the upregulation of their transcription. SIRT6 overexpression partially suppressed the abnormal DNA methylation of NOTCH1 and NOTCH2 by antagonizing DNMT1, leading to an increased capacity of ADSCs for their osteogenic differentiation.

Conclusion

This study demonstrates that SIRT6 physical interacts with the DNMT1 protein, deacetylating and destabilizing DNMT1 protein, leading to the activation of NOTCH1 and NOTCH2, Which in turn promotes the osteogenic differentiation of ADSCs.

Long non‑coding RNA MIR4713HG aggravates malignant behaviors in oral tongue squamous cell carcinoma via binding with microRNA let‑7c‑5p

Oral tongue squamous cell carcinoma (OTSCC) is one of the most aggressive pathological types of head and neck squamous cell carcinoma, and presents with rapid local invasion and metastasis. The present study confirmed that the long non‑coding (lnc) RNA MIR4713HG was markedly upregulated in both OTSCC tissues and cell lines and associated with poor survival. The present study performed a series of experiments to investigate the impact of MIR4713HG on OTSCC and revealed that upregulation of MIR4713HG had a crucial role in promoting cell proliferation and metastasis of OTSCC cell lines both in vitro and in vivo. By applying bioinformatics analyses, micro RNA let‑7c‑5p was observed to physically bind with MIR4713HG, and the knockdown of let‑7c‑5p could counteract the influence of MIR4713HG on OTSCC. Furthermore, the present study demonstrated that let‑7c‑5p performed its regulating role in OTSCC via affecting the expression level of transmembrane channel like 7 (TMC7). In conclusion, the present study demonstrated that lncRNA MIR4713HG acted as a pro‑tumor factor facilitating cell proliferation and metastasis of OTSCC via affecting the let‑7c‑5p/TMC7 signaling pathway, which presents as a promising therapeutic target in OTSCC.

LINC00958 promotes the proliferation of TSCC via miR-211-5p/CENPK axis and activating the JAK/STAT3 signaling pathway

Background

Tongue squamous cell carcinoma (TSCC) is one of the most common oral tumors. Recently, long intergenic noncoding RNA 00958 (LINC00958) has been identified as an oncogene in human cancers. Nevertheless, the role of LINC00958 and its downstream mechanisms in TSCC is still unknown.

Methods

The effect of LINC00958 on TSCC cells proliferation and growth were assessed by CCK-8, colony formation, 5-Ethynyl-2′-deoxyuridline (EdU) assay and flow cytometry assays in vitro and tumor xenograft model in vivo. Bioinformatics analysis was used to predict the target of LINC00958 in TSCC, which was verified by RNA immunoprecipitation and luciferase reporter assays.

Results

LINC00958 was increased in TSCC tissues, and patients with high LINC00958 expression had a shorter overall survival. LINC00958 knockdown significantly decreased the growth rate of TSCC cells both in vitro and in vivo. In mechanism, LINC00958 acted as a ceRNA by competitively sponging miR-211-5p. In addition, we identified CENPK as a direct target gene of miR-211-5p, which was higher in TSCC tissues than that in adjacent normal tissues. Up-regulated miR-211-5p or down-regulated CENPK could abolish LINC00958-induced proliferation promotion in TSCC cells. Furthermore, The overexpression of CENPK promoted the expression of oncogenic cell cycle regulators and activated the JAK/STAT3 signaling.

Conclusions

Our findings suggested that LINC00958 is a potential prognostic biomarker in TSCC.

UTRN inhibits melanoma growth by suppressing p38 and JNK/c-Jun signaling pathways

Background

Utrophin (UTRN), as a tumor suppressor gene, is involved in various cancer progression. The function of UTRN in the melanoma process and the related molecular mechanisms are still unclear. Herein, we studied the function of UTRN in melanoma growth and the relevant molecular mechanisms.

Methods

Using the GEO database and UCSC Xena project, we compared the expression of UTRN in non-cancerous and melanoma tissues. Immunohistochemistry (IHC) staining, qRT-PCR and Western Blot (WB) were performed to evaluate UTRN expression in clinical samples. A total of 447 cases with UTRN expression data, patient characteristics and survival data were extracted from TCGA database and analyzed. After stable transduction and single cell cloning, the proliferation ability of A375 human melanoma cells was analyzed by Cell Counting Kit‑8 (CCK) and 5‑ethynyl‑2′‑deoxyuridine (EdU) incorporation assays. GSEA was performed to predict the mechanism by which UTRN regulated melanoma growth. Then WB analysis was used to assess the protein expression levels of pathway signaling in overexpression (EXP) melanoma cells. Epac activator 8-pCPT-2′-O-Me-cAMP was then used to evaluate the proliferation ability by activation of p38 and JNK/c-Jun signaling pathways.

Results

Data from GEO and UCSC Xena project indicated that UTRN expression was decreased in melanoma. Experiment on clinical samples further confirmed our finding. TCGA results showed that a reduced expression of UTRN in 447 melanoma samples was associated with advanced clinical characteristics (T stage, Clark level, ulceration), shorter survival time and poorer prognosis. In addition, up-regulated UTRN expression inhibited melanoma cell proliferation when compared to control group. MAPK signaling pathway was presented in both KEGG and BioCarta databases by using GSEA tool. WB results confirmed the down-regulated expression of p38, JNK1 and c-Jun in EXP group when compared to control group. Epac activator 8-pCPT-2′-O-Me-cAMP treatment could partially rescue proliferation of tumor cells.

Conclusion

We have demonstrated that reduced UTRN predicted poorer prognosis and UTRN inhibited melanoma growth via p38 and JNK1/c-Jun pathways. Therefore, UTRN could serve as a tumor suppressor and novel prognostic biomarker for melanoma patients.

Hugan Qingzhi medication ameliorates free fatty acid-induced L02 hepatocyte endoplasmic reticulum stress by regulating the activation of PKC-δ

Background

Previous studies have found that Hugan Qingzhi tablet (HQT) has significant lipid-lowering and antioxidant effects on non-alcoholic fatty liver disease (NAFLD). Moreover, the results of proteomic analysis confirmed that various proteins in endoplasmic reticulum stress (ERS) pathway were activated and recovered by HQT. However, its mechanism remains confused. The purpose of this study was to explore the effects of HQT-medicated serum on hepatic ERS and its relevant mechanisms.

Methods

L02 cells were induced by Free Fatty Acid (FFA) for 24 h to establish a model of hepatic ERS and pretreated with the drug-medicated rat serum for 24 h. Accumulation of intracellular lipid was evaluated using Oil Red O staining and Triglyceride detection kit. The morphological changes of ER were observed by TEM. PKC-δ was silenced by specific siRNA. Western blot and RT-qPCR were applied to detect the expression of markers related to ERS, calcium disorder, steatosis and insulin resistance. The fluorescence of Ca²⁺ influx was recorded using fluorescence spectrophotometer.

Results

HQT-medicated serum significantly decreased the intracellular TG content. Furthermore, it caused significant reduction in the expression of ERS markers and an improvement in ER structure of L02 cells. PKC-δ was activated into phosphorylated PKC-δ in FFA-induced L02 hepatocytes while these changes can be reversed by HQT-medicated serum. Silencing PKC-δ in L02 cells can restore the expression and activity of SERCA2 in ER and down-regulate the expression of IP3R protein to maintain intracellular calcium homeostasis, so as to relieve FFA-induced ERS and its lipid accumulation and insulin resistance.

Conclusions

The results concluded that HQT-medicated serum exerts protective effects against hepatic ERS, steatosis and insulin resistance in FFA-induced L02 hepatocyte. And its potential mechanism might be down-regulating the activation of PKC-δ and stabilization of intracellular calcium.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-020-03164-3.

The dietary flavonoid isoliquiritigenin induced apoptosis and suppressed metastasis in melanoma cells: An in vitro and in vivo study

AIMS

This study aimed to explore the role of Isoliquiritigenin (ISL) in the proliferation and invasion of melanoma cells and investigate the mechanism of action of this compound.

MAIN METHODS

The functional roles of ISL in melanoma cells were determined by CCK8 assay, colony formation assay, flow cytometry and wound healing assay. The antitumor activity of ISL was assessed in vivo in a mouse xenograft model using A2058 cells. Quantitative real-time PCR analysis (RT-qPCR) and western blot assays were used to evaluate the gene and protein expression in cell lines or tumor tissue samples. Bioinformatic analysis, luciferase reporter assay, and gene set enrichment analysis (GSEA) were performed to confirm the mechanism of ISL effect on cell growth and metastasis of melanoma.

KEY FINDINGS

ISL suppressed proliferation and migration of melanoma cells via downregulation of miR-27a expression. The inhibitory effect of ISL on growth and metastasis of melanoma cells was reversed by ectopic expression of miR-27a. Bioinformatic analysis showed that miR-27a targets POU class 2 homeobox 3 (POU2F3); this result was verified by the luciferase reporter assay and by a decrease in the expression of POU2F3 by miR-27a intervention. GSEA demonstrated that POU2F3 is associated with the c-MYC/p53 signaling pathway and metastasis. POU2F3 knockdown reversed the inhibitory effect of ISL on the growth and metastasis of melanoma. Additionally, POU2F3 was found to be downregulated in melanoma tissue samples and was negatively correlated with miR-27a.

SIGNIFICANCE

ISL inhibits proliferation and metastasis of melanoma via the miR-27a/POU2F3/c-MYC/p53 axis; these results may provide a new thought for the treatment of melanoma.

Formulation and Characterization of a 3D-Printed Cryptotanshinone-Loaded Niosomal Hydrogel for Topical Therapy of Acne

Cryptotanshinone (CPT) is an efficacious acne treatment, while niosomal hydrogel is a known effective topical drug delivery system that produces a minimal amount of irritation. Three-dimensional (3D) printing technologies have the potential to improve the field of personalized acne treatment. Therefore, this study endeavored to develop a 3D-printed niosomal hydrogel (3DP-NH) containing CPT as a topical delivery system for acne therapy. Specifically, CPT-loaded niosomes were prepared using a reverse phase evaporation method, and the formulation was optimized using a response surface methodology. In vitro characterization showed that optimized CPT-loaded niosomes were below 150 nm in size with an entrapment efficiency of between 67 and 71%. The CPT-loaded niosomes were added in a dropwise manner into the hydrogel to formulate CPT-loaded niosomal hydrogel (CPT-NH), which was then printed as 3DP-CPT-NH with specific drug dose, shape, and size using an extrusion-based 3D printer. The in vitro release behavior of 3DP-CPT-NH was found to follow the Korsmeyer-Peppas model. Permeation and deposition experiments showed significantly higher rates of transdermal flux, Q₂₄, and CPT deposition (p < 0.05) compared with 3D-printed CPT-loaded conventional hydrogel (3DP-CPT-CH), which did not contain niosomes. In vivo anti-acne activity evaluated through an acne rat model revealed that 3DP-CPT-NH exhibited a greater anti-acne effect with no skin irritation. Enhanced skin hydration, wide inter-corneocyte gaps in the stratum corneum and a disturbed lipid arrangement may contribute towards the enhanced penetration properties of CPT. Collectively, this study demonstrated that 3DP-CPT-NH is a promising topical drug delivery system for personalized acne treatments.

Risk factors of perioperative complications and transfusion following total hip arthroplasty in systemic lupus erythematosus patients

BACKGROUND

In recent years, hip arthroplasty rates in systemic lupus erythematosus (SLE) patients have been increasing rapidly. Although patients with SLE generally show beneficial or desirable functional outcomes following total hip arthroplasty (THA), it has been reported that SLE patients after THA have increased risk of postoperative complications, especially during the period of hospitalization.

OBJECTIVES

In the present study, we aimed to identify possible factors associated with complications or transfusion of THA in SLE patients during hospitalization.

METHODS

The present study was a retrospective study conducted in Peking Union Medical College Hospital. Data were collected from medical records of patients who underwent THA from January 2012 to June 2018. The primary outcome variable was perioperative complications, which was defined as having one or more of the following conditions: high fever, infection, impaired wound healing, venous thrombosis of the lower extremities, hematoma, arrhythmia, implant complications. The secondary outcome was perioperative transfusion.

RESULTS

During January 2012 to June 2018, 100 patients had taken the surgery of THA. After multivariate analysis, independent risk factors for perioperative complications were: age ≥ 45 years (p = 0.001), SLE with other connective tissue diseases (p = 0.029), high temperature (p = 0.030), positive anti-dsDNA antibody (p = 0.043), and Systemic Lupus International Collaborative Clinics/American College of Rheumatology (SLICC/ACR) Damage Index ≥ 3 (p = 0.008). Independent risk factors for perioperative transfusion were bilateral THA (p = 0.029), low hemoglobin (p = 0.021) and abnormal renal function (p = 0.021).

CONCLUSION

For SLE patients following THA, age > 45 years, SLE with other connective tissue disease, high temperature, positive anti-dsDNA antibody and SLICC/ACR Damage Index ≥ 3 were the risk factors of complications during hospitalization and bilateral THA, low hemoglobin and abnormal renal function were the risk factors of transfusion.

All-optical inhibitory dynamics in photonic neuron based on polarization mode competition in a VCSEL with an embedded saturable absorber

An all-optical spike inhibition scheme based on polarization-mode competition (PMC) in a vertical-cavity surface-emitting laser (VCSEL) with an embedded saturable absorber is proposed and investigated numerically. The inhibitory dynamics is characterized by spike amplitude and first-spike latency (FSL) for the first time, to the best of our knowledge. The effects of time differences between inhibitory and excitatory inputs, inputs strengths, bias current, as well as noise on the spike amplitude and FSL are examined. The results show that a spike can be triggered in the y-polarization mode by excitatory input and can be inhibited in the presence of inhibitory input due to PMC.

Isoliquiritigenin suppresses human melanoma growth by targeting miR-301b/LRIG1 signaling

BACKGROUND

Isoliquiritigenin (ISL), a natural flavonoid isolated from the root of licorice (Glycyrrhiza uralensis), has shown various pharmacological properties including anti-oxidant, anti-inflammatory and anti-cancer activities. MicroRNAs (miRNAs), a class of small non-coding RNAs, have been reported as post-transcriptional regulators with altered expression levels in melanoma. This study aims to investigate the anti-melanoma effect of ISL and its potential mechanism.

METHODS

We investigated the effect of ISL on the proliferation and apoptosis of melanoma cell lines with functional assays, such as CCK-8 assay, colony formation assay and flow cytometry. The protein level of apoptosis related genes were measured by western blotting. High-throughput genome sequencing was used for screening differentially expressed miRNAs of melanoma cell lines after the treatment of ISL. We performed functional assays to determine the oncogenic role of miR-301b, the most differentially expressed miRNA, and its target gene leucine rich repeats and immunoglobulin like domains 1 (LRIG1), confirmed by bioinformatic analysis, luciferase reporter assay, western blotting and immunohistochemical assay in melanoma. Immunocompromised mouse models were used to determine the role of miR-301b and its target gene in melanoma tumorigenesis in vivo. The relationship between miR-301b and LRIG1 was further verified in GEO data set and tissue specimens.

RESULTS

Functional assays indicated that ISL exerted significant growth inhibition and apoptosis induction on melanoma cells. MiR-301b is the most differentially expressed miRNA after the treatment of ISL and significantly downregulated. The suppressive effect of ISL on cell growth is reversed by ectopic expression of miR-301b. Intratumorally administration of miR-301b angomir enhances the inhibitory effect of ISL on tumor growth in vivo. Bioinformatic analysis showed that miR-301b may target LRIG1, miR-301b suppresses the luciferase activity of reporter constructs containing 3'UTR of LRIG1 as well as the expression level of LRIG1. And the anti-cancer effect of ISL is mitigated when LRIG1 is silenced in vivo and in vitro. Analysis of the melanoma samples obtained from patients shows that LRIG1 is negatively correlated with miR-301b.

CONCLUSIONS

ISL may inhibit the proliferation of melanoma cells by suppressing miR-301b and inducing its target LRIG1.

A Novel Rodent Orthotopic Forelimb Transplantation Model That Allows for Reliable Assessment of Functional Recovery Resulting From Nerve Regeneration

Improved nerve regeneration and functional outcomes would greatly enhance the utility of vascularized composite allotransplantation (VCA) such as hand and upper extremity transplantation. However, research aimed at achieving this goal has been limited by the lack of a functional VCA animal model. We have developed a novel rat midhumeral forelimb transplant model that allows for the characterization of upper extremity functional recovery following transplantation. At the final end point of 12 weeks, we found that animals with forelimb transplantation including median, ulnar and radial nerve coaptation demonstrated significantly improved grip strength and forelimb function as compared to forelimb transplantation without nerve approximation (grip strength: 1.71N ± 0.57 vs. no appreciable recovery; IBB scale: 2.6 ± 0.7? vs. 0.8 ± 0.40; p = 0.0005), and similar recovery to nerve transection-and-repair only (grip strength: 1.71N ± 0.57 vs. 2.03 ± 0.42.6; IBB scale: 2.6 ± 0.7 vs. 2.8 ± 0.8; p = ns). Moreover, all forelimb transplant animals with nerve coaptation displayed robust axonal regeneration with myelination and reduced flexor muscle atrophy when compared to forelimb transplant animals without nerve coaptation. In conclusion, this is the first VCA small-animal model that allows for reliable and reproducible measurement of behavioral functional recovery in addition to histologic evaluation of nerve regeneration and graft reinnervation.

Cryptotanshinone-Loaded Cerasomes Formulation: In Vitro Drug Release, in Vivo Pharmacokinetics, and in Vivo Efficacy for Topical Therapy of Acne

Cerasomes (CS), evolved from liposomes, are novel drug-delivery systems that have potential medical application as carriers for drugs or active ingredients. Although many studies have been conducted on the pharmaceutical and physicochemical properties of CS, the role of CS in influencing the in vivo plasma and topical pharmacokinetics and efficacy of topical drug delivery remain unclear. In this context, we chose cryptotanshinone (CTS) as a model drug for the preparation of CTS-CS by means of the ethanol injection method to investigate their in vitro/in vivo drug-release behavior and in vivo efficacy. (1) In in vitro studies, CTS-CS gel was proven to be capable of achieving a higher permeation rate and significant accumulation in the dermis of isolated rat skin using Franz diffusion cells. (2) In in vivo studies, microdialysis experiments used to measure the plasma and topical pharmacokinetics demonstrated that the CS had a high drug concentration, short peak time, and slow elimination. Meanwhile, the plasma area under the concentration-time curve of CTS-CS gel was less than half that for the CTS gel in 12 h, which indicates that the drug bioavailability dramatically increased in the experiments. (3) In in vivo efficacy studies, we duplicated a rat acne model and performed antiacne efficacy experiments. The CTS-CS gel improved the antiacne efficacy compared to that of ordinary CTS gel. Moreover, it inhibited the expression of interleukin-1α and androgen receptors effectively. All of these results show that CTS-CS gel has significant potential for the treatment of acne induced by inflammation and excessive secretion of androgen, suggesting that CS formulations were designed as a good therapeutic option for skin disease.

Similar enhancement of BK(Ca) channel function despite different aerobic exercise frequency in aging cerebrovascular myocytes

Aerobic exercise showed beneficial influence on cardiovascular systems in aging, and mechanisms underlying vascular adaption remain unclear. Large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels play critical roles in regulating cellular excitability and vascular tone. This study determined the effects of aerobic exercise on aging-associated functional changes in BK(Ca) channels in cerebrovascular myocytes, Male Wistar rats aged 20-22 months were randomly assigned to sedentary (O-SED), low training frequency (O-EXL), and high training frequency group (O-EXH). Young rats were used as control. Compared to young rats, whole-cell BK(Ca) current was decreased, and amplitude of spontaneous transient outward currents were reduced. The open probability and Ca(2+)/voltage sensitivity of single BK(Ca) channel were declined in O-SED, accompanied with a reduction of tamoxifen-induced BK(Ca) activation; the mean open time of BK(Ca) channels was shortened whereas close time was prolonged. Aerobic exercise training markedly alleviated the aging-associated decline independent of training frequency. Exercise three times rather than five times weekly may be a time and cost-saving training volume required to offer beneficial effects to offset the functional declines of BK(Ca) during aging.

Metal-insulator transition in the quasi-one-dimensional transport of fractional quantum Hall states

We investigate edge state transmission in quantum point contacts (QPCs) in the fractional quantum-Hall regime, finding behavior reminiscent of a metal-insulator transition. The transition is suggested by an unusual behavior of the differential conductance in the fractional-quantum-Hall regime, and by the presence of a fixed point and universal scaling in the temperature dependence of the linear conductance. Noting that the 0.7 feature evolves continuously into a last fractional plateau at high magnetic fields, we suggest that this still unresolved feature may itself be viewed as a manifestation of a local, microscopic, metal-insulator transition.

Sensory processing differences and urinary incontinence in school-aged children

OBJECTIVE

Urinary Incontinence (UI) is a common problem among school-aged children (5-11 years). Symptoms such as urgency, diminished awareness of wetting, or apparent apathy may represent differences in sensory processing (SP). This study aims to describe the SP abilities of incontinent school-aged children with typical development to determine if they differ from established norms for continent children.

MATERIALS AND METHODS

The SP abilities of 209 school-aged children with UI were evaluated using the short sensory profile (SSP), a judgment-based caregiver questionnaire, then compared with established norms using descriptive and inferential statistics.

RESULTS

Forty-four percent of children showed significant differences in global SP with the greatest differences noted in tactile sensitivity. Higher section subscores were also noted in "seeks sensation/under responsive" and "auditory sensitivity". Children with dysfunctional voiding (DV) were more likely to show global differences (p = 0.015), differences in "seeks sensation" (p = 0.006), and auditory sensitivity (p = 0.041). The odds for low tactile sensitivity scores were five times greater for children with UI and DV (p = 0.006).

CONCLUSION

These results suggest that differences in SP may be found among typical school aged children with UI. Continued research is indicated to understand the significance of the study results.

On the zero-bias anomaly and Kondo physics in quantum point contacts near pinch-off

We investigate the linear and non-linear conductance of quantum point contacts (QPCs), in the region near pinch-off where Kondo physics has previously been connected to the appearance of the 0.7 feature. In studies of seven different QPCs, fabricated in the same high-mobility GaAs/AlGaAs heterojunction, the linear conductance is widely found to show the presence of the 0.7 feature. The differential conductance, on the other hand, does not generally exhibit the zero-bias anomaly (ZBA) that has been proposed to indicate the Kondo effect. Indeed, even in the small subset of QPCs found to exhibit such an anomaly, the linear conductance does not always follow the universal temperature-dependent scaling behavior expected for the Kondo effect. Taken collectively, our observations demonstrate that, unlike the 0.7 feature, the ZBA is not a generic feature of low-temperature QPC conduction. We furthermore conclude that the mere observation of the ZBA alone is insufficient evidence for concluding that Kondo physics is active. While we do not rule out the possibility that the Kondo effect may occur in QPCs, our results appear to indicate that its observation requires a very strict set of conditions to be satisfied. This should be contrasted with the case of the 0.7 feature, which has been apparent since the earliest experimental investigations of QPC transport.

Hierarchical Bayesian modeling of heterogeneous variances in average daily weight gain of commercial feedlot cattle

Variability in ADG of feedlot cattle can affect profits, thus making overall returns more unstable. Hence, knowledge of the factors that contribute to heterogeneity of variances in animal performance can help feedlot managers evaluate risks and minimize profit volatility when making managerial and economic decisions in commercial feedlots. The objectives of the present study were to evaluate heteroskedasticity, defined as heterogeneity of variances, in ADG of cohorts of commercial feedlot cattle, and to identify cattle demographic factors at feedlot arrival as potential sources of variance heterogeneity, accounting for cohort- and feedlot-level information in the data structure. An operational dataset compiled from 24,050 cohorts from 25 U. S. commercial feedlots in 2005 and 2006 was used for this study. Inference was based on a hierarchical Bayesian model implemented with Markov chain Monte Carlo, whereby cohorts were modeled at the residual level and feedlot-year clusters were modeled as random effects. Forward model selection based on deviance information criteria was used to screen potentially important explanatory variables for heteroskedasticity at cohort- and feedlot-year levels. The Bayesian modeling framework was preferred as it naturally accommodates the inherently hierarchical structure of feedlot data whereby cohorts are nested within feedlot-year clusters. Evidence for heterogeneity of variance components of ADG was substantial and primarily concentrated at the cohort level. Feedlot-year specific effects were, by far, the greatest contributors to ADG heteroskedasticity among cohorts, with an estimated ∼12-fold change in dispersion between most and least extreme feedlot-year clusters. In addition, identifiable demographic factors associated with greater heterogeneity of cohort-level variance included smaller cohort sizes, fewer days on feed, and greater arrival BW, as well as feedlot arrival during summer months. These results support that heterogeneity of variances in ADG is prevalent in feedlot performance and indicate potential sources of heteroskedasticity. Further investigation of factors associated with heteroskedasticity in feedlot performance is warranted to increase consistency and uniformity in commercial beef cattle production and subsequent profitability.

Oscillation of clock and clock controlled genes induced by serum shock in human breast epithelial and breast cancer cells: regulation by melatonin

This study investigates differences in expression of clock and clock-controlled genes (CCGs) between human breast epithelial and breast cancer cells and breast tumor xenografts in circadian intact rats and examines if the pineal hormone melatonin influences clock gene and CCG expression. Oscillation of clock gene expression was not observed under standard growth conditions in vitro, however, serum shock (50% horse serum for 2 h) induced oscillation of clock gene and CCG expression in MCF-10A cells, which was repressed or disrupted in MCF-7 cells. Melatonin administration following serum shock differentially suppressed or induced clock gene (Bmal1 and Per2) and CCG expression in MCF10A and MCF-7 cells. These studies demonstrate the lack of rhythmic expression of clock genes and CCGs of cells in vitro and that transplantation of breast cancer cells as xenografts into circadian competent hosts re-establishes a circadian rhythm in the peripheral clock genes of tumor cells.

Combined hepatocellular cholangiocarcinoma originating from hepatic progenitor cells: immunohistochemical and double-fluorescence immunostaining evidence

AIMS

Combined hepatocellular cholangiocarcinoma (CHC) is a rare form of primary liver cancer, showing a mixture of hepatocellular and biliary features. Data suggest that most CHC arise from hepatic progenitor cells (HPCs). The aim was to investigate the origin of CHC.

METHODS AND RESULTS

Twelve cases of CHC were studied by immunohistochemistry for hepatocytic (hepPar1, alpha-fetoprotein), cholangiocytic cytokeratin [(CK) 7, CK19], hepatic progenitor cell (OV-6), haematopoietic stem cell (c-kit, CD34), as well as CD45 and chromogranin-A markers. The combination of double-fluorescence immunostaining consisted of HepPar1 with CK19, and c-kit with OV-6. All 12 cases demonstrated more or less transitional areas, with strands/trabeculae of small, uniform, oval-shaped cells including scant cytoplasm and hyperchromatic nuclei embedded within a thick, desmoplastic stroma; however, two cases were found to consist entirely of such transitional areas. Simultaneous co-expression of hepPar1 and CK7, or CK19, was demonstrated in 10/12 (83.3%) cases of CHC. c-kit expression was noted in 10/12 (83.3%) cases, of which 7/10 (70%) showed co-expression of OV-6.

CONCLUSIONS

The results suggest that CHC are of HPC origin, supporting the concept that human hepatocarcinogenesis may originate from the transformation of HPCs.

Entropy maximization constrained by solvent flatness: a new method for macromolecular phase extension and map improvement

A practical generally applicable procedure for exponential modeling to maximum likelihood of macromolecular data sets constrained by a moderately large basis set of reliable phases and a molecular envelope is described, based on the computer program MICE [Bricogne & Gilmore (1990). Acta Cryst. A46, 284-297]. Procedures were first tested with simulated data sets. Exact and randomly perturbed amplitudes and phases were generated, together with a known envelope for solvent-free protein and for protein in an electron-dense crystal mother liquor typical of many real protein crystals. These experiments established useful guidelines and values for various parameters. Tests with basis sets chosen from the largest amplitudes indicate that exponential models with considerable correct extrapolated phase and amplitude information can be constructed from as few as 16% of the total number of reflections, with mean phase errors of about 30 degrees, at resolution limits of either 5 or 3 A. When the shape of the solvent channels in macromolecular crystals is known, it offers an important additional source of information. MICE was, therefore, adapted to average the density outside the molecular boundary defined by an input envelope. This flattening process imposes a uniform density distribution in solvent-filled channels as an additional constraint on the exponential model and is analogous to the treatment of solvent in conventional solvent flattening. Experimental data for cytidine deaminase, a structure recently solved by making extensive use of conventional solvent flattening, provides an example of the performance of maximum-entropy methods in a real situation and a compelling comparison of this method to standard procedures. Exponential models of the electron density constrained by the most reliable phases obtained by multiple isomorphous replacement with anomalous scattering (MIRAS) (figure of merit > 0.7, representing 34% of the total number of reflections) and by the envelope give rise to centroid electron-density maps which are quantitatively superior by numerous statistical criteria to conventionally solvent-flattened density. Similarity of these maps to the 2F(obs) - F(calc) map calculated with phases obtained after crystallographic refinement of the model implies that maximum-entropy extrapolation provides better phases for the remaining 66% of the reflections than the original centroid MIRAS distributions. Importantly, the solvent-flattened electron density, although it did permit interpretation of the map which was not readily accomplished with the MIRAS map, contains substantial errors. It is proposed that errors of this sort may account for previously noted deficiencies of the solvent-flattening method [Fenderson, Herriott & Adman (1990). J. Appl. Cryst. 23, 115-131] and for the occasional tendency of incorrect interpretations to be 'locked in' by crystallographic refinement [Brändén & Jones (1990). Nature (London), 343, 687-689, and references cited therein]. Solvent flattening with combined maximization of entropy and likelihood represents a phase-refinement path independent of atomic models, using the experimental amplitudes and the most reliable phases. It should, therefore, become a valuable and generally useful procedure in macromolecular crystal structure determination.

MR Quantification of Flow in Children with Vein of Galen Malformations

SUMMARY

Vein of Galen vascular malformations are either Vein of Galen Aneurysmal malformations (VGAMs) or Vein of Galen Aneurysmal Dilatations (VGADs). VGAMs may be of the choroidal or mural type and are fistulas associated with the precursor of the vein of Galen. The treatment of VGAMs is aimed at controlling the size of the vascular shunt since it is believed that the shunt is responsible for venous hypertension, cardiac stress, delayed development and may be so large as to damage the brain. In VGAMs as noted by Berenstein and Lasjaunias. Absolute measures of flow may contribute to our understanding of CNS disease and permit objective measures of the success or failure of therapeutic interventions (5). MR phase contrast cine angiographic techniques can be employed to measure bulk flow in intracranial vessels. Vein of Galen vascular malformations are an ideal model to measure venous flow as the draining vein is large and angiographic evaluation is limited. Thus our goal was to develop an objective non-invasive method of measuring vascular flow in VGAMs and VGADs (6) . Herein we report our experience using this technique in a group of patients with Vein of Galen vascular malformations. We also hypothesized that the degree of shunting would correlate to the degree of cardiac stress and be an indicator of optimal timing for intervention. We believe that we have succeeded in our goal to develop an objective, non-invasive method of shunt quantification using velocity encoded MR sequences. This promises new insight into the hemodynamics, natural history and treatment response of vascular malformations.

On the relationship between protein stability and folding kinetics: a comparative study of the N-terminal domains of RNase HI, E. coli and Bacillus stearothermophilus L9

There is currently a great deal of interest in proteins that fold in a single highly cooperative step. Particular attention has been focused on elucidating the factors that govern folding rates of simple proteins. Recently, the topology of the native state has been proposed to be the most important determinant of their folding rates. Here we report a comparative study of the folding of three topologically equivalent proteins that adapt a particularly simple alpha/beta fold. The folding kinetics of the N-terminal domain of RNase HI and the N-terminal domain of the ribosomal protein L9 from Escherichia coli (eNTL9) were compared to the previously characterized N-terminal domain of L9 from Bacillus stearothermophilus (bNTL9). This 6.2 kDa protein, which is one of simplest examples of the ABCalphaD motif, folds via a two-state mechanism on the millisecond to submillisecond time scale. The RNase HI domain and bNTL9 have very similar tertiary structures but there is little similarity in primary sequence. bNTL9 and eNTL9 share the same biological function and a similar primary sequence but differ significantly in stability. Fluorescence-detected stopped-flow experiments showed that the three proteins fold in a two-state fashion. The folding rates in the absence of denaturant were found to be very different, ranging form 21 s(-1) to 790 s(-1) at 10 degrees C. The diverse folding rates appear to reflect large differences in the stability of the proteins. When compared at an isostability point, the folding rates converged to a similar value and there is a strong linear correlation between the log of the folding rate and stability for this set of proteins. These observations are consistent with the idea that stability can play an important role in dictating relative folding rates among topologically equivalent proteins.

Binding of low density lipoproteins to lipoprotein lipase is dependent on lipids but not on apolipoprotein B

Lipoprotein lipase (LPL) efficiently mediates the binding of lipoprotein particles to lipoprotein receptors and to proteoglycans at cell surfaces and in the extracellular matrix. It has been proposed that LPL increases the retention of atherogenic lipoproteins in the vessel wall and mediates the uptake of lipoproteins in cells, thereby promoting lipid accumulation and plaque formation. We investigated the interaction between LPL and low density lipoproteins (LDLs) with special reference to the protein-protein interaction between LPL and apolipoprotein B (apoB). Chemical modification of lysines and arginines in apoB or mutation of its main proteoglycan binding site did not abolish the interaction of LDL with LPL as shown by surface plasmon resonance (SPR) and by experiments with THP-I macrophages. Recombinant LDL with either apoB100 or apoB48 bound with similar affinity. In contrast, partial delipidation of LDL markedly decreased binding to LPL. In cell culture experiments, phosphatidylcholine-containing liposomes competed efficiently with LDL for binding to LPL. Each LDL particle bound several (up to 15) LPL dimers as determined by SPR and by experiments with THP-I macrophages. A recombinant NH(2)-terminal fragment of apoB (apoB17) bound with low affinity to LPL as shown by SPR, but this interaction was completely abolished by partial delipidation of apoB17. We conclude that the LPL-apoB interaction is not significant in bridging LDL to cell surfaces and matrix components; the main interaction is between LPL and the LDL lipids.

The distinct roles of T cell-derived cytokines and a novel follicular dendritic cell-signaling molecule 8D6 in germinal center-B cell differentiation

Germinal center-B (GC-B) cells differentiate into memory B cells and plasma cells (PC) through interaction with T cells and follicular dendritic cells (FDC). Activated T cell and FDC play distinct roles in this process. The detailed kinetic experiments revealed that cytokines secreted by activated T cells determined the pathway of GC-B cell differentiation. IL-4 directs GC-B cells to differentiate into memory B cells, whereas IL-10 steers them into PC. FDC/HK cells do not direct either pathway, but provide signals for proliferation of GC-B cells. A novel FDC-signaling molecule 8D6 (FDC-SM-8D6) produced by FDC augments PC generation in the GC. FDC-SM-8D6-specific mAb blocked PC generation and IgG secretion but not memory B cell proliferation. COS cells expressing FDC-SM-8D6 enhanced GC-B cell proliferation and Ab secretion, which was blocked by mAb 8D6. In the cultures with B cell subsets, PC generation was inhibited by mAb 8D6 in the cultures with CD27(+) B cells but not in the culture with CD27(-) B cells, suggesting that CD27(+) PC precursor is the specific target of FDC-SM-8D6 stimulation.

The crystal structure of Escherichia coli MoeA and its relationship to the multifunctional protein gephyrin

BACKGROUND

Molybdenum cofactor (Moco) biosynthesis is an evolutionarily conserved pathway present in archaea, eubacteria, and eukaryotes. In humans, genetic abnormalities in the biosynthetic pathway result in Moco deficiency, which is accompanied by severe neurological symptoms and death shortly after birth. The Escherichia coli MoeA and MogA proteins are involved in the final step of Moco biosynthesis: the incorporation of molybdenum into molybdopterin (MPT), the organic pyranopterin moiety of Moco.

RESULTS

The crystal structure of E. coli MoeA has been refined at 2 A resolution and reveals that the highly elongated MoeA monomer consists of four clearly separated domains, one of which is structurally related to MogA, indicating a divergent evolutionary relationship between both proteins. The active form of MoeA is a dimer, and a putative active site appears to be localized to a cleft formed between domain II of the first monomer and domains III and IV of the second monomer.

CONCLUSIONS

In eukaryotes, MogA and MoeA are fused into a single polypeptide chain. The corresponding mammalian protein gephyrin has also been implicated in the anchoring of glycinergic receptors to the cytoskeleton at inhibitory synapses. Based on the structures of MoeA and MogA, gephyrin is surmised to be a highly organized molecule containing at least five domains. This multidomain arrangement could provide a structural basis for its functional diversity. The oligomeric states of MoeA and MogA suggest how gephyrin could assemble into a hexagonal scaffold at inhibitory synapses.

Non-Hodgkin Lymphomas of Mice

Studies of lymphoid neoplasms occurring in normal or genetically engineered mice have revealed parallels and differences to non-Hodgkin lymphomas (NHL) of humans. Some mouse lymphomas have strong histologic similarities to the human NHL subsets including precursor B- and T-cell lymphoblastic, small lymphocytic, splenic marginal zone, and diffuse large-cell B-cell lymphomas (DLCL); whether molecular parallels also exist is under study. Others mouse types such as sIg+ lymphoblastic B-cell lymphoma have no histologic equivalent in human NHL even though they share molecular deregulation of BCL6 with human DLCL. Finally, Burkitt lymphoma does not appear to occur naturally in mice, but it can be induced with appropriately engineered transgenes.

Doppler standard deviation imaging for clinical monitoring of in vivo human skin blood flow

We used a novel phase-resolved optical Doppler tomographic (ODT) technique with very high flow-velocity sensitivity (10microm/s) and high spatial resolution (10microm) to image blood flow in port-wine stain (PWS) birthmarks in human skin. In addition to the regular ODT velocity and structural images, we use the variance of blood flow velocity to map the PWS vessels. Our device combines ODT and therapeutic systems such that PWS blood flow can be monitored in situ before and after laser treatment. To the authors' knowledge this is the first clinical application of ODT to provide a fast semiquantitative evaluation of the efficacy of PWS laser therapy in situ and in real time.

Effects of hepatic artery chemotherapeutic embolization combined with perfusing LAK cells into hepatic artery after radical operation of liver cancer

OBJECTIVE

To evaluate the effects of hepatic artery chemotherapeutic embolization combined with perfusing LAK cells/interleukin 2 into hepatic artery after radical operation of liver cancer.

METHODS

Random divide 42 cases into two groups who had accepted radical operation of liver cancer: 21 cases who accepted hepatic artery chemotherapeutic embolization combined with perfusing LAK cells/interleukin 2 into hepatic artery as observing group, 21 cases accepted simply hepatic artery chemotherapeutic embolization as control group.

RESULTS

The intrahepatic recurrence rates of 1, 2, and 3 years were 0, 19.05%, 57.14% in observing group, lower than 28.57%, 47.62%, 85.71% of control group (chi(2)=4.86, 3. 86 and 4.20 respectively, P<0.05). The survival rates of 2 and 3 years were 85.71%, 61.90% in observing group, higher than 57.14%, 28. 57% of control group (chi(2)=4.20 and 4.71, P<0.05).

CONCLUSION

Hepatic artery chemotherapeutic embolization combined with perfusing LAK cells/interleukin 2 into hepatic artery is an effective therapeutic method to control intrahepatic recurrence rates and raise the survival rates of the patients.