OBJECTIVETo investigate α-toxin-induced apoptosis of umbilical vein endothelial cells and explore its role in vertical infection of Staphylococcus aureus L-form.

METHODSHUV-EC-C cells exposed to different concentrations (0, 10, 30, 90, and 270 ng/ml) of α-toxin for different time lengths (0, 2, 4, 6, and 8 h) were examined for apoptosis using flow cytometry with Annexin V-PI staining. The levels of tumor necrosis factor-α (TNF-α) and the activities of, caspase-3 and caspase-8 in the cell culture were detected by ELISA and colorimetric method, respectively. α-Toxin-induced cell apoptosis was also analyzed in HUV-EC-C cells treated with a neutralizing antibody of TNF-α or with the inhibitory peptides of caspase-3 (zDEVD-FMK) and caspase-8 (zIETD-fmk).

RESULTSα-Toxin induced apoptosis of HUV-EC-C cells in a dose- and time-dependent manner and caused significantly enhanced expression of TNF-α and the activation of both caspase-3 and caspase-8. Inhibition of TNF-α with its neutralizing antibody and the inhibitory peptides of caspase-3 or -8 all significantly decreased α-toxin-induced cell apoptosis, and the caspase-3 inhibitor completely blocked α-toxin-induced cell apoptosis.

CONCLUSIONα-Toxin-induced apoptosis is partially mediated by the extrinsic cell death pathway of TNF-α and caspase-8 and plays an important role in the vertical infection of S. aureus L-form to affect fetal growth and development.

Apoptosis ; Bacterial Toxins ; toxicity ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; L Forms ; Staphylococcal Infections ; Staphylococcus aureus ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the influence of maternal staphylococcal enterotoxin B (SEB) administration during pregnancy on CD3⁺ TCR Vβ8⁺T cells of adult offspring rats.

METHODSPregnant maternal rats at gestational day (GD) 16 were injected intravenously with 15 µg SEB in 0.2 ml PBS (SEB group), and the control rats receive the same volume of PBS. Flow cytometry was used to determine the levels of CD3⁺ TCR Vβ8⁺T cells in both the thymus and peripheral blood of adult offspring rats and the response of these cells to a secondary SEB administration.

RESULTSMaternal SEB administration during pregnancy significantly decreased the percentages of CD3⁺TCR Vβ8⁺T cells in the thymus in adult female (1.760-2.714) and male (1.098-2.088) offspring rats (P<0.05). The change of CD3⁺TCR Vβ8⁺T cells in the peripheral blood was similar to that in the thymus. In the control adult offspring rats, SEB administration at adulthood significantly reduced the percentages of CD3⁺TCR Vβ8⁺T cells in both the thymus and peripheral blood (P<0.05). But in SEB group, a secondary SEB administration in adult offspring rats significantly increased the percentage of CD3⁺TCR Vβ8⁺T cells in the peripheral blood (P<0.05) but not in the thymus (P>0.05).

CONCLUSIONMaternal SEB administration during pregnancy can change the response of CD3⁺ TCR Vβ8⁺T cells of adult offspring rats to a secondary SEB administration.

Animals ; Enterotoxins ; adverse effects ; Female ; Male ; Maternal Exposure ; adverse effects ; Pregnancy ; Rats ; Rats, Sprague-Dawley ; T-Lymphocyte Subsets ; drug effects

Objective To identify the differences inneuropsychological characteristics between amnestic(AMCI)and vascular mild cognitive impairment(VMCI).Methods Totally 297 old community residents with mild cognitive impairment(MCI)were divided into amnestic MCI(AMCI)and vascular MCI(VMCI)subgroup from Guangzhou MCI prevalence survey.The elderly with MCI were interviewed and tested with the Chinese version of Montreal Cognitive Assessment(MoCA),the Mini-Mental state examination(MMSE),Auditory Verbal Learning Test(AVLT),the Clinical Dementia Rating scale(CDR),Functional Activity Questionnaire(FAQ),the Modified Hachinski Ischemic Scale(M-HIS),Center for Epidemiologic Studies(CES-DC)to evaluate neuropsychological characteristics.Results AMCI versus VMCI group showed that the total scores of MoCA were(9.63±5.17 vs.9.98±6.02),total scores of MMSE were(16.90±4.84 vs.16.90±6.19),AVLT immediate memory was(2.35±1.39 vs.2.91±1.84),AVLT delayed recall was(2.23±2.09 vs.2.47±2.20),AVLT delayed recognition was(7.33±3.98 vs.6.85±4.02)and total scores of CDR(0.5 vs.0.5),with no differences between the 2 groups(all P>0.05).Based on MoCA survey,AMCI versus VMCI group showed statistically significant differences(all P<0.05)in parameters of visual space and execution(0.71±1.02 vs.0.92±1.26),language function(0.34±0.56 vs.0.50±0.80)and abstract thinking(0.25±0.49 vs.0.15±0.43),but based on MMSE survey,no difference was found in the various cognitive domains between the two groups.The AMCI versus VMCI group showed statistically significant differences(all P<0.05)in parameters of CES-DC scale(1.75±4.27 vs.2.76±6.72),FAQ scale(4.42±4.66 vs.8.71±7.03),M-HIS scale(0.40±0.64 vs.7.59±3.53).Conclusions There is no significant difference in general cognitive impairment between AMCI and VMCI,but the visual space and execution,language function are more impaired in AMCI than VMCI,and the abstract thinking,social function are more impaired with more depressive symptoms in VMCI than in AMCI.

Objective: To evaluate response to public health emergencies in colleges and universities and associated factors, and to provide references for emergency response mechanisms in colleges. Methods: Using stratified random sampling, recruited 7 719 students in 6 universities in Shandong Province during April May 2020, and analyzed the data with SPSS 25.0 software. Results: About 65.5% of college students reported response to public health emergencies in their college, 67.7% of the students reported that colleges have emergency plans, 53.9% of the students reported that colleges have carried out simulated emergency training, and 64.7% of the students reported that colleges have carried out health education. Evaluation from students for responding to public health emergencies in colleges and universities scored(24.15±4.59), of which measures and policies related to epidemic control were highest(4.05±0.81), while mental health education or counselling services were lowest (3.95±0.85). Gender, grade, major, type of household registration, emergency response measures, emergency response plan, emergency simulation training, health education were associated with the evaluation of the measures by college students(t/F=5.04，43.83，79.92，-3.40，26.86，34.83，29.35，35.01，P<0.01). Conclusion While recognizing the overall performance on public health responses in universities, college students believe certain limitations still exist; colleges and universities should continuously improve the emergency prevention and control system of public health emergencies in response to the effectiveness and deficiencies in the prevention and control process.