OBJECTIVE To find out the imipenem-resistan metallo-?-lactamase in P.aeruginosa to provide the proof of treatment for clinic.METHODS A multi-disk was used to detect the metallo-?-lactamase of P.aeruginosa and the K-B disk method was used for monitoring of the antibiotic-resistance to 15 antibiotics.RESULTS Fifteen strains producing metallo-?-lactamase were isolated from 93 imipenem-resistant P.aeruginosa strains.The positive rate with metallo-?-lactamase was 16.1%(15/93).The susceptibility tests showed the lower resistance was to cefoperazone sulbactam(Sulperazone),amikacin and piperacillinl tazobactam(Tazocin).their resistance rate respectively was 16.8%,24.8% and 26.6%.The resistance rate to ciprofloxacin and ceftazidime was 43.7% and 33.6%.The resistance rate over 90.0% was to ampicillin,ampicilillin/sulbactam,cefazolin,cefpodoxime,cefuroxime and so on.CONCLUSIONS P.aeruginosa with imipenem-resistance shows seriou multidrug-resistance.The metallo-?-lactamase is the main reason for P.aeruginosa resistance to imipenem and cephalosporins.The doctors should choose antibiotics reasonably according to the susceptibility test when taking effective treatment to P.aeruginosa infection.

OBJECTIVE To investigate the distribution and resistance of clinical isolates to antimicrobial agents commonly used.Antimicrobial agents should be used rationally based on the results of susceptibility testing.METHODS The clinical isolates were identified with W/A-40 or VITEK-32.The results were analyzed by WHONET 5.3 software according to CLSI 2005.RESULTS A total of 2892 clinical isolates were collected in 2007.Gram-negative bacilli accounted for 68.2% and Gram-positive cocci accounted for 31.8%.The top eight pathogens were Pseudomonas aeruginosa,Escherichia coli,Klebsiella spp,Acinetobacter spp,coagulase-negative Staphylococcus,Enterobacter spp,Serratia spp and S.aureus.About 76.4% of S.aureus isolates were MRSA,81.6% of coagulase-negative Staphylococcus isolates were meticillin-resistant.Under 20.0% of Enterobacteriaceae strains were resistant to cefoperazone/sulbactam,imipenem and piperacillin/tazobactam.About 16.3% and 32.5% of P.aeruginosa isolates were resistant to cefoperazone/sulbactam and imipenem.CONCLUSIONS Gram-negative bacilli were dominant isolates in our hospital during 2007.P.aeruginosa is the most frequent pathogenwith severe antibiotic resistance.Enterobacteriaceae are susceptible to cefoperazone/sulbactam and imipenem.

OBJECTIVE To study the distributive properties and susceptibility of yeasts to six antifungal agents. METHODS To analyze the distributive properties of 264 clinical Candida spp isolates and study the susceptibility to amphotericin B,nystatin,fluconazole,ketoconazole,miconazole and clotrimazole.The susceptibility of yeasts was tested according to the National Committee for Clinical Laboratory Standards guideline(NCCLS M27-A2). RESULTS Strains of Candida albicans were the most frequent organism isolated accounted for 62.5% of all the isolates.C.tropicalis,C.glabrata,and C.parapsilosis accounted for 20.8%,12.5%,and 1.9%,the others accounted for only 2.3%.The main infected organs were lungs,urinary tract,and digestive tract;the susceptibility tests showed strains of Candida spp to nystatin,amphotericin B,and fluconazole were more active than to the other antifungal agents.The resistance to triazole antifugal agents could be shown. CONCLUSIONS We should strengthen the diagnosis of Candida spp and strengthen the surveillance on susceptibility of clinical isolates Candida spp so as to help the doctors choose the antifungal agents reasonably.

OBJECTIVE To develop a macroarray method to detect pathogens in cerebrospinal fluid.METHODS According to the bacterial 16S rRNA genes,designed 10 kinds of specific probes and a pair of universal primers that can amplify rRNA gene of all bacteria.The tailed probes were spotted onto a nylon membrane.DNA was isolated from each pathogen,and subjected to UP-PCR to amplify target fragments,which were labeled with bio-16-dUTP at the same time.All those denatured fragments were hybridized to the probes on nylon membrane and visualized by AKP labeled avidin.The sensitivity and specificity of the system were detected.A total of 32 CSF samples,which were verified the bacterial infection by the routine method,were tested by this method.RESULTS It was sensitive to 10 CFU/ml when detecting Escherichia coli.Every kind of pathogens only reacted to its corresponding probes fixed on nylon membranes,which showed high specificity.The result of identifying 32 CSF clinical specimens accorded with that of routine method.CONCLUSIONS The method can screen out common pathogens in CSF sensitively and exactly.

Small molecule drug screening technology is continuously evolving and expanding along with drug discovery,and the innovation in drug screening technology can improve the research and development efficiency and success rate,shorten the cycle time,and reduce the cost.From traditional screening technologies based on known active compounds and high-throughput screening(HTS)to new technologies such as structure-based drug discovery(SBDD),fragment-based drug discovery(FBDD),DNA encoded compound library(DEL)and proteolysis targeting chimeras(PROTAC),small molecule drug screening technologies are continuously broadening the market potential for small molecule drugs.This article will provide an overview of the current status of small molecule drug screening technology,systematically review each technique along with their advantages and disadvantages,and offer essential insights for the development of new small molecule drug screening technologies.

Objective:To compare the therapeutic effects of modified plantar skin grafting and thigh skin grafting on the deep burn wounds of the back and buttocks.Methods:A retrospective cohort study was conducted to analyze the clinical data of 30 patients with deep burn wounds on their back and buttocks who were admitted to the 910th Hospital of Joint Logistic Support Force of PLA from January 2021 to April 2023, including 26 males and 4 females, aged 21-72 years [(49.9±14.0)years]. The total burn size was 50%-97% of the total body surface area (TBSA), with the third-degree burn on the back and buttocks 6%-16% TBSA. The burn wounds on the back and buttocks were repaired using plantar skin grafts alone, thigh skin grafts alone or plantar skin grafts combined with the grafts from other body parts. The patients were grouped according to the skin graft donor sites and the times of harvesting skin grafts: there were 20 patients undergone plantar skin grafting including 10 patient with plantar skin graft harvested once (group of plantar skin graft harvested once) and 10 patients with plantar skin graft harvested twice or three times (group of plantar skin graft harvested more than once), and 10 patients undergone thigh skin grafting harvested once (group of thigh skin graft harvested once). The areas of plantar skin grafts harvested at the last time and the wound areas on the back and butts that could be repaired each time were calculated. After the last harvest, the thickness of the stratum corneum, 7-day survival rate of the skin grafts, proportion of 3-month residual wound area in the skin graft area, healing time of the donor sites, and 6-month Vancouver Scar Scale (VSS) scores of the donor sites in the group of plantar skin graft harvested once were compared with those in the group of thigh skin graft harvested once and the group of plantar skin graft harvested more than once. The appearance and texture of the skin graft, patients′ walking patterns and complications were observed at 6 months after the last skin harvest.Results:All the patients were followed up for 6-18 months [(7.8±1.6)months]. In the 20 patients with plantar skin grafts harvested, the areas of skin grafts harvested at the last time were 2.5%-4.5% TBSA [(3.4±0.6)% TBSA] and the wound areas that could be repaired each time were 3%-8% TBSA [(5.5±1.5)% TBSA]. After the last harvest, the thickness of the stratum corneum in the group of plantar skin graft harvested once was (190.4±8.9)μm, which was significantly thicker than that in the group of thigh skin graft harvested once [(50.0±6.6)μm] and that in the group of plantar skin graft harvested more than once [(166.8±21.9)μm] ( P<0.01); the 7-day survival rate of the skin grafts, proportion of 3-month residual wound area in the skin graft area, healing time of the donor sites, and 6-month VSS scores of the donor sites were (93.6±2.3)%, 2.0 (0.1, 3.5)%, (9.9±1.8)days and (1.7±0.7)points in the group of plantar skin graft harvested once, (78.0±6.6)%, 5.3 (4.0, 5.8)%, (14.0±1.4)days and (4.9±2.3)points in the group of thigh skin graft harvested once, and (93.4±2.6) %, 2.0 (0.1, 3.8)%, (10.0±1.2)days and (1.8±0.8)points in the group of plantar skin graft harvested more than once. The group of plantar skin graft harvested once showed a significant increase in the 7-day survival rate and a significant decrease in the proportion of 3-month residual wound area in the skin graft area, healing time of the donor sites, and 6-month VSS scores of the donor sites in comparison with the group of thigh skin graft harvested once ( P<0.05 or 0.01), while there were no significant differences in above mentioned indices between the group of plantar skin graft harvested once and the group of plantar skin graft harvested more than once ( P>0.05). At 6 months after the last skin harvest, the skin graft areas on the back and buttocks were flat, hard and firm and all the patients in the three groups could walk normally, with no complications such as severe itching, pain or folliculitis in the skin graft area. Conclusions:In the treatment of burn wounds on the back and buttocks, compared with thigh skin grafting, modified plantar skin grafting has advantages of thicker stratum corneum, better wear resistance and pressure resistance in the skin graft areas, a higher survival rate of skin grafts, rapid healing, mild scar, and undisturbed walking pattern after surgery and no common complications. Moreover, skin grafts can be harvested repeatedly from the donor sites, with no impact on the therapeutic effects.

Aging increases the risk of various diseases. The main goal of aging research is to find therapies that attenuate aging and alleviate aging-related diseases. In this study, we screened a natural product library for geroprotective compounds using Werner syndrome (WS) human mesenchymal stem cells (hMSCs), a premature aging model that we recently established. Ten candidate compounds were identified and quercetin was investigated in detail due to its leading effects. Mechanistic studies revealed that quercetin alleviated senescence via the enhancement of cell proliferation and restoration of heterochromatin architecture in WS hMSCs. RNA-sequencing analysis revealed the transcriptional commonalities and differences in the geroprotective effects by quercetin and Vitamin C. Besides WS hMSCs, quercetin also attenuated cellular senescence in Hutchinson-Gilford progeria syndrome (HGPS) and physiological-aging hMSCs. Taken together, our study identifies quercetin as a geroprotective agent against accelerated and natural aging in hMSCs, providing a potential therapeutic intervention for treating age-associated disorders.

Aging-induced changes in the immune system are associated with a higher incidence of infection and vaccination failure. Lymph nodes, which filter the lymph to identify and fight infections, play a central role in this process. However, careful characterization of the impact of aging on lymph nodes and associated autoimmune diseases is lacking. We combined single-cell RNA sequencing (scRNA-seq) with flow cytometry to delineate the immune cell atlas of cervical draining lymph nodes (CDLNs) of both young and old mice with or without experimental autoimmune uveitis (EAU). We found extensive and complicated changes in the cellular constituents of CDLNs during aging. When confronted with autoimmune challenges, old mice developed milder EAU compared to young mice. Within this EAU process, we highlighted that the pathogenicity of T helper 17 cells (Th17) was dampened, as shown by reduced GM-CSF secretion in old mice. The mitigated secretion of GM-CSF contributed to alleviation of IL-23 secretion by antigen-presenting cells (APCs) and may, in turn, weaken APCs' effects on facilitating the pathogenicity of Th17 cells. Meanwhile, our study further unveiled that aging downregulated GM-CSF secretion through reducing both the transcript and protein levels of IL-23R in Th17 cells from CDLNs. Overall, aging altered immune cell responses, especially through toning down Th17 cells, counteracting EAU challenge in old mice.
Aging ; Animals ; Autoimmune Diseases ; Disease Models, Animal ; Granulocyte-Macrophage Colony-Stimulating Factor/metabolism* ; Mice ; Mice, Inbred C57BL ; Th17 Cells/metabolism* ; Uveitis/pathology* ; Virulence

Age-associated changes in immune cells have been linked to an increased risk for infection. However, a global and detailed characterization of the changes that human circulating immune cells undergo with age is lacking. Here, we combined scRNA-seq, mass cytometry and scATAC-seq to compare immune cell types in peripheral blood collected from young and old subjects and patients with COVID-19. We found that the immune cell landscape was reprogrammed with age and was characterized by T cell polarization from naive and memory cells to effector, cytotoxic, exhausted and regulatory cells, along with increased late natural killer cells, age-associated B cells, inflammatory monocytes and age-associated dendritic cells. In addition, the expression of genes, which were implicated in coronavirus susceptibility, was upregulated in a cell subtype-specific manner with age. Notably, COVID-19 promoted age-induced immune cell polarization and gene expression related to inflammation and cellular senescence. Therefore, these findings suggest that a dysregulated immune system and increased gene expression associated with SARS-CoV-2 susceptibility may at least partially account for COVID-19 vulnerability in the elderly.
Adult ; Aged ; Aged, 80 and over ; Aging ; genetics ; immunology ; Betacoronavirus ; CD4-Positive T-Lymphocytes ; metabolism ; Cell Lineage ; Chromatin Assembly and Disassembly ; Coronavirus Infections ; immunology ; Cytokine Release Syndrome ; etiology ; immunology ; Cytokines ; biosynthesis ; genetics ; Disease Susceptibility ; Flow Cytometry ; methods ; Gene Expression Profiling ; Gene Expression Regulation, Developmental ; Gene Rearrangement ; Humans ; Immune System ; cytology ; growth & development ; immunology ; Immunocompetence ; genetics ; Inflammation ; genetics ; immunology ; Mass Spectrometry ; methods ; Middle Aged ; Pandemics ; Pneumonia, Viral ; immunology ; Sequence Analysis, RNA ; Single-Cell Analysis ; Transcriptome ; Young Adult