Effects of diet and antibiotics on anastomotic healing: A mouse model study with varied dietary fiber and fat, and pre-operative antibiotics

INTRODUCTION

This study investigated the separate impacts of diet and pre-operative antibiotics on gut microbiome and colonic anastomotic healing using a mouse model.

METHODS

Male C57BL/6J mice were fed either low-fat-high-fibre (SD) or high-fat-low-fiber (WD) groups for 6 weeks, then further received either pre-operative antibiotics or a control sham before a colonic anastomotic procedure was performed. After 7 days, the anastomosis was assessed and microbiota composition and biodiversity were analyzed in anastomotic tissue and stool.

RESULTS

WD-fed mice had shorter survival (5.2 ​± ​2.3 vs. 6.9 ​± ​2.3 days, p ​= ​0.022), increased weight loss (5.55 ​± ​3.80g vs. 2.65 ​± ​2.36g, p ​= ​0.03), and reduced biodiversity compared to SD-fed mice. Pre-operative antibiotics improved anastomotic healing scores (1.33 ​± ​0.65 vs. 2.08 ​± ​0.79, p ​= ​0.02) and reduced Enterococcus faecalis growth in tissue and stool (p ​= ​0.02, p ​= ​0.02). Improved anastomotic healing correlated with lower Enterococcus abundance (p ​= ​0.04) and higher collagen III and IV levels (p ​= ​0.01, 0.04) in anastomotic tissue.

CONCLUSION

SD promotes enhanced post-operative recovery and increased microbiome biodiversity, while pre-operative antibiotics enhance anastomotic healing by suppressing Enterococcus faecalis growth, mitigating collagen III/IV degradation.

[Molecular epidemiological characterization of hypervirulent carbapenem-resistant Klebsiella pneumoniae in a hospital in Henan Province from 2020 to 2022]

Objective: The study investigated the clinical distribution, antimicrobial resistance and epidemiologic characteristics of hypervirulent Carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) in a hospital in Henan Province to provide a scientific basis for antibiotic use and nosocomial infection prevention and control. Methods: A retrospective analysis of the clinical data from the cases was carried out in this study. Clinical data of patients infected with the CRKP strain isolated from the clinical microbiology laboratory of Henan Provincial Hospital of Traditional Chinese Medicine from January 2020 to December 2022 were retrospectively analyzed. A string test, virulence gene screening, serum killing, and a G. mellonella infection model were used to screen hv-CRKP isolates. The clinical characteristics of hv-CRKP and the drug resistance rate of hv-CRKP to twenty-five antibiotics were analyzed using WHONET 5.6. Carbapenemase phenotypic characterization of the hv-CRKP was performed by colloidal gold immunochromatographic assay, and Carbapenemase genotyping, multi-locus sequence typing (MLST) and capsular serotyping of hv-CRKP isolates were performed by PCR and Sanger sequencing. Results: A total of non-duplicate 264 CRKP clinical isolates were detected in the hospital from 2020 to 2022, and 23 hv-CRKP isolates were detected, so the corresponding detection rate of hv-CRKP was 8.71% (23/264). The hv-CRKP isolates in this study were mainly from the intensive care unit (10/23) and neurosurgery department (8/23), and the main sources of hv-CRKP isolates were sputum (10/23) and bronchoalveolar lavage fluid (6/23). The hv-CRKP isolates in this study were highly resistant to β-lactam antibiotics, fluoroquinolones and aminoglycosides, and were only susceptible to colistin, tigecycline and ceftazidime/avibactam. The detection rate of the blaKPC-2 among 23 hv-CRKP isolates was 91.30% (21/23) and none of the class B and class D carbapenemases were detected. Results of MLST and capsular serotypes showed that ST11 type hv-CRKP was the dominant strain in the hospital, accounting for 56.52% (13/23), and K64 (9/13) and KL47 (4/13) were the major capsular serotypes. Conclusion: The hv-CRKP isolates from the hospital are mainly from lower respiratory tract specimens from patients admitted to the intensive care department and the drug resistance is relatively severe. The predominant strains with certain polymorphisms are mainly composed of the KPC-2-producing ST11-K64 and ST11-KL47 hv-CRKP isolates in the hospital.

[Constructions and advances of animal models of Pseudomonas aeruginosa infection]

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogenic bacterium with complex pathogenesis and drug resistance mechanisms. It has high morbidity and mortality and can cause acute and chronic infections in immunocompromised individuals, with lung infections, wound infections, and bloodstream infections being the most common. The animal infection model of P. aeruginosa is of great value for in-depth research on the pathogenicity, drug resistance, and therapeutic measures of P. aeruginosa by simulating the pathways of human bacterial infections. This article firstly summarizes the selection, anesthesia, and disposal of experimental animals in the construction of animal models of P. aeruginosa infection, and then reviews the methods of construction, model evaluation, and applications of animal models of P. aeruginosa pulmonary infection, wound infection, and bloodstream infection, in order to provide a reference for scientific research related to P. aeruginosa infectious diseases.

[Sensitization characteristics of Juniperus chinensis pollen in Beijing area]

Objective: To investigate the sensitization characteristics of Juniperus chinensis pollen in patients with allergic rhinitis and/or allergic asthma in Beijing area, and to explore the characteristics of Juniper chinensis pollen sensitized population. Methods: Patients with suspected allergic rhinitis and/or asthma from January 2017 to December 2019 in the outpatient department of Allergy Department of Beijing Shijitan Hospital were selected in this study. Skin prick test (SPT) was performed with Juniper chinensis pollen allergen reagent to compare different age and disease allergen distribution, and to observe the sensitization characteristics of its population. All of the analyses were performed using SAS software version 9.4. Results: A total of 8 380 patients were enrolled in the end. The total positive rate of Juniper chinensis pollen SPT reached 49.92% (4 183/8 380). The positive rate of Juniper chinensis pollen SPT was highest in the 10-14 age group, reaching 60.99% (283/464). Compared with other age groups, there was a statistical difference (χ²=266.77, P<0.01). The SPT positive rate of patients aged less than 10 years increased with the increase of age, while the SPT positive rate of patients aged over 40 years decreased with the increase of age. Single Juniper chinensis pollen was less allergenic, accounting for about 25.05% (1 048/4 183), and the patients' age was (35.21±12.39) years. Regardless of single Juniper chinensis pollen or other pollen allergies, allergic rhinitis was the main disease. Among the patients with SPT positive Juniper chinensis pollen combined with other inhaled pollen allergens, willow pollen accounted for the first (74.99%). The positive rate of Juniper chinensis pollen was the highest in patients with single allergic rhinitis, accounting for 52.05% (3 797/7 295), and the rate in patients with single allergic asthma was the lowest, accounting for 17.49% (53/303), with statistically difference (χ²=138.99, P<0.01). Conclusions: Juniper chinensis pollen is highly sensitized in patients with allergic rhinitis and/or allergic asthma in Beijing . The positive rate of SPT is highest among 10-14 age group, most of which showed strong positive reaction, and allergic rhinitis is more common in Juniper chinensis pollen sensitization diseases.

Prioritization and surgical wait lists: A cross-sectional survey of patient's health-related quality of life

INTRODUCTION

In many countries, there are waits for elective (planned) surgery. In these settings, processes for triaging patients are applied to determine how long patients wait for their surgery. There are very few instances that evaluate the effectiveness of surgical triage processes.

METHODS

A sample of patients from four acute care hospitals in Vancouver, Canada, completed a number of patient-reported outcomes shortly after being registered on the surgical wait list. Patients' diagnosis was used to triage and determine their expected wait for surgery. The associations between patient-reported outcomes with surgical triage were measured.

RESULTS

The mean wait times for participants were similar across wait times categories. Participants whose expected waits for surgery were the longest reported successively lower levels of self-rated health (p < 0.01) and successively higher levels of pain (p < 0.01.) There was no difference in symptoms of anxiety among participants expected to wait the longest.

DISCUSSION

The diagnosis-based system for prioritizing patients found higher levels of pain and lower health status among those expected to wait the longest for their surgery. Screening waiting patients for treatable mental health conditions should be implemented and the process of surgical triage could be redesigned to allow for a broader set of attributes of health to determine how long a patient waits for their elective surgery.

[Research progress on virulence factors of hypervirulent Klebsiella pneumoniae]

Hypervirulent Klebsiella pneumoniae, short for hvKP, is a hypervirulent variant of classical Klebsiella pneumoniae, which accounts for serious infection in healthy people, exhibits strong pathogenicity, high mortality and poor prognosis. At present, hvkp is of high prevalence all over the world, and the infection rate shows a continuous upward trend, which brings great challenges to public health security and clinical treatment. This paper summarized the research progress on virulence factors of hvkp, such as capsular polysaccharides, siderophore, lipopolysaccharide, adhesins and recently discovered Type Ⅵ secreting system, and aimed to deepen the understanding and recognition of hvKP.

[Reoperation rate and related factors in patients with Crohn's disease]

Objective: To analyze the cumulative reoperation rate of postoperative Crohn's disease (CD) patients and investigate the operation reasons and the effects of drugs on surgical recurrence. Method: Patients with Crohn's disease who had undergone intestinal resection from January 2000 to March 2020 in Peking Union Medical College Hospital were enrolled. Patients were divided into reoperation and non-reoperation group according to whether they had a second operation. And the basic characteristics and the reasons for the primary and second operation were retrospectively analyzed. Meanwhile, patients were divided into low-risk reoperation group and high-risk group based on risk stratification. Kaplan-Meier methods were performed to analyze the cumulative surgical recurrence rate and to compare the recurrence rate in different risk stratification and chi-square tests was used to analyze the effects of different maintenance drugs on reoperation. Result: A total of 160 patients were enrolled in the study. There were 110 males and 50 females, and the age at first operation was (35.6±14.1) years old. There were 40 patients in the reoperation group and 120 patients in the non-reoperation group. According to univariate analysis, the proportion of male gender(P=0.030), penetrating phenotype(P<0.001), history of appendectomy before the primary surgery(P=0.035) and no postoperative maintenance therapy (P<0.001) were higher in surgical recurrence group. In terms of the operation reasons, intestinal obstruction accounted for the highest proportion in the primary operation (26.9%, 43/160), while the intestinal fistula was the most common reason for reoperation (42.5%, 17/40). After the primary surgery, the cumulative reoperation rates at 1, 3, 5 and 10 years were 5.9% (9 cases), 12.3% (17 cases), 21.8% (25 cases) and 37.6% (34 cases), respectively. The ten years cumulative reoperation rate of the high-risk group was 42.8% (31 cases), which was much higher than that of low-risk group (19.8%, 3 cases), and the difference was statistically significant (P=0.006). There was no statistically significant difference in the surgical recurrence rate of low-risk group patients(P=0.076)whether maintenance therapies were added or not, while the recurrence rate of high-risk group patients who did not receive maintenance therapy was higher than those who received immunosuppressant with or without (±) 5-aminosalicylic acid (ASA) (P=0.001) and biological agent±5-ASA (P=0.001), and the difference was statistically significant. Conclusion: Patients with CD are still at risk of reoperation after surgery. Immunosuppressive agents and biologics can prevent patients from reoperation in high-risk groups.

Current surgical treatment of intermediate risk differentiated thyroid cancer: a systematic review

Introduction: Surgical treatment of thyroid cancer has become less aggressive but for many patients, the threshold for performing total thyroidectomy (TT), as opposed to thyroid lobectomy (TL), has remained unclear. Current American Thyroid Association (ATA) guidelines encourage more individualization of treatment options, which necessitates explicit review of the pros and cons of the different options with patients.Areas covered: This review focuses on the extent of surgery for treatment of intermediate-risk differentiated thyroid cancer, restricted to relevant literature available after publication of the 2015 ATA guidelines.Expert opinion: Dynamic risk-stratification facilitates a tailored approach when deciding on the extent of surgery for thyroid cancer. Treatment with TT allows for a lower recurrence risk, a simpler follow-up regimen, and treatment with adjuvant post-operative radioactive iodine. Treatment with TL has a lower associated risk of complications and avoidance of lifelong thyroid hormone replacement but has a significant risk of requiring a completion thyroid lobectomy (CT). Overall, treatment with TL and TT have comparable survival outcomes, but TL is the more cost-effective option. Larger cancer size is correlated with worse clinical outcomes, and numerous subgroup analyses have shown poorer outcomes for cancers with a diameter that is 2-4 cm compared to 1-2 cm.

[Research progress on the regulation mechanism of Pseudomonas aeruginosa biofilm]

Pseudomonas aeruginosa is one of the common multidrug-resistant bacteria in the clinic. Because it can produce a "protective" biofilm, it can affect the penetration and killing efficacy of antibacterial drugs, leading to the formation of a persistent and persistent chronic infection in the host. Biofilms make Pseudomonas aeruginosa resistant to antibacterials and evasive to the host's immune system. Therefore, traditional conventional antibacterials are difficult to achieve effective bactericidal treatment. Understanding the process of P. aeruginosa biofilm formation and the regulatory mechanisms that affect biofilms can provide ideas and methods for our future research on new antibacterial drugs.

Risk of sexual dysfunction with progestin-based contraceptives in women of child-bearing age

PURPOSE

To examine whether there is a positive association between sexual dysfunction (SD) and different types of progestin-based contraceptives.

METHODS

Nested case-control study in women of child-bearing age (15-45 years) from the IQVIA® Ambulatory electronic medical record database from 2008 to 2018. Cases defined by diagnosis of sexual dysfunction identified by international classification for disease clinical modification code 9th and 10th. Each case was matched to four controls and rates of prescriptions of the following were compared: levonorgestrel intra-uterine device (IUD), progestin, and ethinyl estradiol (EE) combined oral contraceptive (COC) formulations including levonorgestrel, norgestimate, drospirenone, desogestrel, norethindrone, and norgestrel; etonogestrel vaginal ring; and medroxyprogesterone injection.

RESULTS

Overall, 6689 cases of patients with SD were matched to 26,756 matched controls. Compared with matched controls, more subjects with SD used levonorgestrel IUD (OR 1.24, 95% CI 1.08-1.44), EE-levonorgestrel COC (OR 1.18, 95% CI 1.00-1.41), EE-drospirenone (OR 1.28, 95% CI 1.00-1.67), and medroxyprogesterone (OR 1.38, 95% CI 1.12-1.70). The use of norgestrel exhibited a protective effect (OR 0.83, 95% CI 0.73-0.95). When using the EE-levonorgestrel COC as a comparator, norgestrel users exhibited a protective effect (OR 0.70, 95% CI 0.57-0.87) while no other contraceptives showed a statistically significant difference in association with SD.

CONCLUSION

Our study found an increase in the use of levonorgestrel (COC and IUD), drospirenone, and medroxyprogesterone in subjects with SD. The risk of contraceptives did not differ when compared with oral levonorgestrel. The small association size and lack of difference between drug formulations suggest a minimal impact of progestin-based contraceptives on sexual dysfunction.

[Analysis on clinical features of patients with ulcerative colitis associated colorectal cancer]

Objective: To analyze the clinical features of ulcerative colitis associated colorectal cancer (UC-CRC). Methods: A total of 869 inpatients with Ulcerative Colitis (UC) in Peking Union Medical Hospital from January 1998 to January 2018 were continuously enrolled. Clinical data and the outcome of colorectal cancer (CRC) were collected via medical records and telephone follow-up. Chi-square test and logistic regression model were used to analyze the data. Results: There were 16 patients in 869 UC inpatients who were diagnosed with CRC during a period of 7 548 person years and the incidence rate of UC-CRC was 1.84%. Compared to UC inpatients without CRC, a longer course of disease (OR=1.087, 95% CI:1.046-1.129) , a lower usage rate of 5-Aminosalicylic Acid(5-ASA) (OR=0.218, 95% CI:0.052-0.915) and a higher incidence rate of intestinal stenosis (OR=16.533, 95% CI:3.824-71.478) were found in UC inpatients with CRC. Conclusions: A long disease course is a risk factor for UC patients developing CRC, while 5-ASA therapy can reduce the risk of suffering from CRC. For UC patients with intestinal stenosis, CRC should be warned for occurring.

Characterization of microbial community profiles associated with quality of Chinese strong-aromatic liquor through metagenomics

AIMS

Microorganisms in fermentation pits (FPs) play key roles for Chinese-strong-aromatic-liquor (CSAL) production. However, the microbial community in the FPs is still poorly understood. Here, the aim of this study was to reveal the diversity and potential functions of microbiota in FPs.

METHODS AND RESULTS

Sequencing-by-synthesis-based metagenomic sequencing and annotation results revealed that the microbiota of FPs was primarily composed of Firmicutes (54·6%), Euryarchaeota (15·3%), Bacteroidetes (10·1%), Gammaproteobacteria (5·8%), Opisthokonta (5·7%) and Unclassified_Bacteria (2·3%). And 133 genera were identified as the dominant genera of this fermentative food. Lactobacillus, Sedimentibacter, Syntrophomonas, Methanoculleus, Methanobacterium, Bacillus, Clostridium, Galactomyces, Candida, Pichia, Penicillium and Aspergillus were defined as active populations for biosynthesizing the characteristic volatile compounds of CSAL. The study also revealed that the microbial community structures changed significantly with different cellar ages and over different geographical regions. (i) The presence of Bacteroidetes was the most distinctive feature that characterized the different FPs ages. (ii) Distinct contents of Gammaproteobacteria and Euryarchaeota were observed at different positions in the FPs. (iii) Euryarchaeota markedly contributed to the generation of the character of the liquors with distinct geographical associations.

CONCLUSIONS

This study demonstrated that the changes of microbial communities determined the different quality characteristics of CSAL.

SIGNIFICANCE AND IMPACT OF THE STUDY

This research contributes to a deeper understanding of the FPs microbial composition and shows a new microbial resource for biotechnological applications.

One year effectiveness study of intravitreal aflibercept in neovascular age-related macular degeneration: a meta-analysis

The current body of evidence on the efficacy and safety of aflibercept for age-related macular degeneration (AMD) is steadily growing as large clinical trials and observational studies are continually completed. Our aim was to analyse 1-year visual acuity (VA) outcomes in response to aflibercept therapy and identify factors affecting treatment response using evidence generated from a pooled analysis of current studies. A literature review of multiple electronic databases (EMBASE, MEDLINE, MedMEME) revealed 12 studies meeting inclusion and exclusion criteria for statistical analysis. Treatment posology, baseline patient characteristics, study type, sample size and 12-month change in VA were pooled in a meta-analysis with VA change as the main outcome. Data were then stratified by study design and posology in subgroup analyses. A meta-regression was conducted to regress 12-month VA change against posology, baseline VA and age. Users of aflibercept experienced an overall increase of 7.37 letters (95% confidence interval: 6.27-8.48, p heterogeneity: <0.001) in VA at 12 months of follow-up. In subgroup analyses, mean VA change was higher for randomized control trials and cohorts following regular posology (>7 injections/year) compared to observational studies and irregular posology. The meta-regression showed larger VA gains with regular posology compared to an irregular posology, and decreased effect size as age increased. This meta-analysis strongly suggests improved VA outcomes at 12 months in patients with wet AMD for 2.0 mg aflibercept, comparable to but slightly lower than landmark trials. Increased injection frequency and younger age demonstrates a trend with improved outcomes.

One-Year Effectiveness Study of Intravitreous Ranibizumab in Wet (Neovascular) Age-Related Macular Degeneration: A Meta-Analysis

PURPOSE

The clinical efficacy of ranibizumab has been examined by a large number of prospective and retrospective studies to date. This meta-analysis was conducted to summarize the current body of evidence on visual acuity (VA) changes with use of ranibizumab in the treatment of wet (neovascular) age-related macular degeneration (wAMD).

METHODS

A literature review of multiple electronic databases (EMBASE, MEDLINE, MedMEME) was conducted to find randomized controlled trials (RCTs) and observational studies that reported changes in VA while patients with wAMD were on ranibizumab. Study factors analyzed were baseline patient characteristics, study type, sample size, and 12-month change in VA. Data were pooled in a meta-analysis with VA change as the main outcome. Data were then stratified by study design and a meta-regression was conducted to assess 12-month VA change against baseline VA and age.

RESULTS

A total of 42 studies were included for analysis. An overall increase of 5.58 letters (95% confidence interval [CI]: 4.42-6.75; p heterogeneity, < 0.001) was shown with use of ranibizumab compared to baseline. Improvements in VA were larger for RCTs, at 7.71 letters (95% CI: 6.66-8.76; p heterogeneity, 0.013), compared to observational studies, at 4.85 letters (95% CI: 3.32-6.38; p heterogeneity, < 0.001). The meta-regression showed a significant decrease in effect size between baseline VA and 12-month VA change.

CONCLUSION

This meta-analysis suggests visual improvements at 12 months of 0.5-mg ranibizumab use in patients with wAMD. A higher gain in VA was observed when pooling results from RCTs compared to those in observational studies.

[Immunometabolism and systemic lupus erythematosus]

Systemic lupus erythematosus (SLE) is a highly heterogeneous autoimmune disease, characterized by production of pathogenic autoantibodies and wide involvement of multiple systems. Damageofimmune tolerance and imbalance of immune homeostasis lead to the production of autoantibodies and the injuries of multiple organs and systems. In recent years, plenty of studies have identified that immunometabolism affects survival status of certain cells, also cell activation, differentiation and effector functions. Conversely, immune cells with different functions or differentiational status upregulate specific metabolic pathways to maintain their identities. In response to outer stimulations, naive immune cells differentiate into activated cells, accompanied with a series of immunometabolism changes. Therefore, abnormal immunometabolism can induce global imbalance of immune homeostasis, which further results in the initiation and development of autoimmune diseases, including SLE. Multiple abnormalities of immunometabolism have been found in patients with SLE or mouse models of lupus. Immune cells involved in the development of SLE, such as T cells, B cells, dendritic cells and macrophages present various metabolic abnormalities and pathological phenotypes. Among these cells, CD4+ T cells play predominant roles in the pathogenesis of SLE. Lots of studies demonstrated that CD4+ T cells and their subsets were in abnormal immunometabolic status,which further resulted in the development of SLE. In CD4+ T cells from patients with SLE or mouse models of lupus, both levels of glycolysis and oxidative phosphorylation are significantly higher compared with healthy controls. However,mitochondrial abnormalities, decreased ATP production and increased level of oxidative stress also have been found in these cells, which play important roles in the production of reactive oxygen intermediates and autoantibodies. Aggregated lipids rafts and increased synthesis of glycosphingolipid and cholesterol also have been observed in the CD4+ T cells from patients with SLE, leading to the abnormally elevated TCR signaling. Moreover, mechanistic target of rapamycin (mTOR) signaling is activated in the CD4+ T cells from both patients with SLE or mouse models of lupus and participate in the metabolic abnormalities of pathological CD4+ T cells. Progressive understanding of immunometabolism give us new insights of the pathogenesis of SLE and provide us with more therapeutic targets in the treatment of SLE.

Transcriptome analysis of potential simple sequence repeat markers in Ammopiptanthus mongolicus

Ammopiptanthus mongolicus, an evergreen broadleaf legume shrub, can survive under conditions of high and low temperature, extreme salinity, and drought. This attribute makes it an ideal model for studying mechanisms of stress tolerance in plants. However, simple sequence repeat (SSR) resources for this species are insufficient in public databases. In this study, a total of 44,959 unigenes identified from the A. mongolicus transcriptome were used for SSR analysis by MIcroSAtellite (MISA). A total of 13,859 SSRs were found to be distributed within 10,409 unigenes, with an average length of 15 bp and an average density of one SSR per 4.4 kb. There were 222 different motif types in the A. mongolicus transcriptome, and mononucleotide repeats represented the main type, accounting for 44.2% of all SSRs. The (A/T)n repeat was the most frequent motif, accounting for 42.37% of all SSRs. We also performed Gene Ontology functional analysis, Kyoto Encyclopedia of Genes and Genomes database pathway analysis, and eggNOG analysis, and identified 6157, 2301, and 9845 unigenes containing SSRs in these three databases, respectively. The functional categorization of A. mongolicus unigenes containing SSRs revealed that these unigenes represent many transcribed genes with different functions. These data provide sequence information that may be used to improve molecular-assisted markers for the study A. mongolicus genetic diversity.

Antibacterial activity of ZnO nanoparticles with a modified surface under ambient illumination

In various practical applications, nanomaterials typically have functionalized surfaces. Yet, the studies of toxicity and antibacterial activity of functionalized nanoparticles are scarce. We investigated the effect of surface modifications on antibacterial activity of ZnO under ambient illumination, and we found that nanoparticles coated with different surface modifying reagents could exhibit higher or lower toxicity compared to bare ZnO, depending on the surface modifying reagent used. Different surface modifying reagent molecules resulted in differences in the release of Zn(2+) ions and the production of reactive oxygen species (ROS). However, the antibacterial activity did not correlate with the ROS levels or the Zn(2+) ion release. One of the surface-modified ZnO samples exhibited significantly lower Zn(2+) ion release while at the same time exhibiting improved antibacterial activity. In all cases, damage of the cell wall membranes and/or changes in the membrane permeability have been observed, together with the changes in ATR-FTIR spectra indicating differences in protein conformation. Mechanisms of antibacterial activity are discussed.

Effect of suppression of TGF-beta1 expression on cell-cycle and gene expression of beta-1,4-galactosyltransferase 1 in human hepatocarcinoma cells

beta-1,4-galactosyltransferase 1 (beta1,4-GT 1) is localized both in the Golgi complex where it catalyzes the transfer of galactose from UDP-galactose to terminal N-acetylglucosamine forming Galbeta1 --> 4GlcNAc structure, and on the cell surface where it serves as an adhesion molecule. It has previously been reported that the expression of beta1,4-GT 1 was cell-cycle-specific, regulated by cell growth. Transforming growth factor-beta1 (TGF-beta1) could regulate cell G1/S phase transition and modulate cell growth in many types of cells. In this study, we introduced the antisense-TGF-beta1 into SMMC-7721 cell, a human hepatocarcinoma cell line, for blocking its intrinsic TGF-beta1 expression, and changing its cell-cycle, and then analyzed the gene expression of beta1,4-GT 1 together with the beta1,4-GT activity. The result showed that the antisense-TGF-beta1 transfected SMMC-7721 cells (AST/7721) were growth enhanced, with more cells in S phase and less cells in G2/M phase compared with the mock transfected cells (pcDNA3/7721). At the same time, it was found that the gene expression of beta1,4-GT 1 in AST/7721 was decreased to one fifth that of pcDNA3/7721, and the cell surface beta1,4-GT activity was reduced to one fifth of the control, while the total activity of beta1,4-GT was decreased to one half that of the control. The results indicate that suppression of TGF-beta1 expression resulted in change of cell-cycle together with the decreased gene expression of beta1,4-GT 1 and beta1,4-GT activity in human hepatocarcinoma cells.

In situ hybridization of hepatitis B DNA in hepatitis B-associated glomerulonephritis

Renal tissues from 43 of 49 children with hepatitis B virus-associated glomerulonephritis (HBV-GN) were examined for HBV DNA by in situ hybridization (ISH) assay within the last 10 years. HBV DNA was identified in 41 of the 43 cases (95.3%). HBV DNA was distributed generally in the nucleus and cytoplasm of epithelial cells and mesangial cells of glomeruli, and epithelial cells of renal tubules. HBV DNA also existed simultaneously in renal interstitial tissues in some of these cases. The positive results from HBV DNA ISH correlated well with HBV antigen assays. The analyses implied that the more extensive the existence of HBV DNA in the nephron unit and interstitial tissue, the more severe the clinical manifestation. The duration of proteinuria in cases with HBV DNA in renal tubules was much longer than in those with no HBV DNA in renal tubules. The persistence of the HBV genome or genes in the kidney could lead to the expression of viral antigens in renal tissues and might cause cellular pathological alteration. This would support utilization of antiviral therapy, such as cytokines, in the treatment of HBV-GN.

[Further study on the immunopathology of hepatitis B virus associated glomerulonephritis]

By using immunohistochemical techniques the deposition of HBV associated immune complexes was studied in 845 consecutive cases of renal biopsy. In 665 cases of primary glomerulonephritis the frequencies of HBsAg, HBeAg and HBcAg detection in glomeruli were 11.9%, 8.3% and 3.2% respectively with a total HBV antigen positive frequency of 12.2%. High positive rates were found in membranous glomerulonephritis (MGN, 37.1%), mesangioproliferative GN (MPGN, 26%) and IgA nephropathy (IgA-NP, 18.9%). The detection of HBV infection markers in serum were simultaneously performed in 213 cases; 31.7% of the patients with primary GN were found to be positive. In patients with positive HBV infectious markers in the serum, deposits of HBV antigens in glomeruli were found in 49.1% of the cases. The incidence was significantly different in the serum negative group (10.6%). Meanwhile, about 68.3% of the cases with HBV antigen deposits in the kidney was found to have positive HBV markers in the serum. Also the incidence was significantly different in the group without HBV antigen deposits in the kidney (20.9%). It was again confirmed that the pathogenesis of hepatitis B virus associated glomerulonephritis (HBV-GN) was related to the deposition of HBV immune complexes in kidney tissue. It was noticed that the deposition of three different types of HBV antigens was somewhat associated with the development of specific forms of HBV GN. The diagnostic criteria of HBV-GN were discussed in detail.

[Immunohistochemical study of the expression of major histocompatibility complex (MHC)-determined antigens in renal tissue of MRL/lpr mice]

Expression of MHC antigens in renal tissue of MRL/lpr(H-2K) mice were demonstrated by monoclonal antibodies against class I(KK) and class II(IAK) antigens and ABC immunoperoxidase method. The expression of KK antigen in glomeruli, tubules and vessels of kidney and IAK antigen in glomeruli tubules was stronger in mice fed with beef tallow diet after gamma-interferon treatment than in the control group. This result suggests that using of gamma-interferon may enhance the presentation of MHC antigens in renal tissue of MRL/lpr mice. In mice raised with Menhaden fish oil diet after gamma-interferon treatment, however, the enhancement of expression of IAK antigen was detected only in renal tubules. In comparing with mice fed with beef tallow after gamma-interferon injection, the expression of KK antigen in glomeruli, vessels and IAK in the dendritic cells of renal interstitium was weaker in mice fed with fish oil. This result indicates that fish oil can more or less inhibit the expression of MHC antigens in renal tissue of mice. The mechanism of the inhibitory action of fish oil remains to be elucidated.