Prognostic value of PaO2/FiO2, SOFA and D-dimer in elderly patients with sepsis.

OBJECTIVE: To investigate the prognostic value for predicting mortality of partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2), the Sequential Organ Failure Assessment (SOFA) score and D-dimer in elderly patients with sepsis. METHODS: This retrospective cohort study enrolled elderly patients with sepsis admitted to the intensive care unit (ICU) between January 2019 and October 2020. Patients were divided into a survival group and a non-survival group. Biomarkers, SOFA, Acute Physiology and Chronic Health Evaluation II and Glasgow Coma Scale scores were recorded within 24 h after admission to the ICU. RESULTS: A total of 135 elderly patients with sepsis were enrolled in the study: 89 were in the survival group and 46 were in the non-survival group at 28 days. Univariate and multivariate regression analyses demonstrated that PaO2/FiO2, SOFA and D-dimer were independently associated with 28-day mortality. The predictive performance for mortality of the combination of PaO2/FiO2, SOFA score and D-dimer (area under the receiver operating characteristic curve of 0.926) was higher than the values for the individual factors (0.761, 0.745 and 0.878, respectively). CONCLUSION: The combination of PaO2/FiO2, SOFA score and D-dimer represents a promising tool and biomarker for predicting 28-day mortality of the elderly patients with sepsis.

Protection of guinea pigs against Leptospira interrogans serovar Lai by LipL21 DNA vaccine.

In this study, the full lipL21 gene fragment encoding outer membrane protein LipL21 was cloned from L. interrogans serovar Lai and inserted into eukaryotic expression vector pcDNA3.1(+). The guinea pigs were immunized with pcDNA3.1(+)-lipL21, pcDNA3.1(+) or PBS. Six weeks after the second immunization, the splenocytes were isolated to detect their proliferative ability by lymphocyte transformation experiments. In addition, microscopic agglutination test was used for quantitative detection of specific antibodies. The rest guinea pigs were challenged intraperitoneally with L. interogans sorevar Lai. Then, protective effect was evaluated on the basis of survival and histopathological lesions in the kidneys, lungs, and liver. The lipL21 gene was successfully expressed in COS-7 cells through recombinant pcDNA3.1(+)-lipL21. The titer of specific antibodies substantially increased, and the stimulation index of splenocytes increased significantly. Hence, the pcDNA3.1(+)-lipL21 could protect the immunized guinea pigs from homotypic Leptospira infection. Furthermore, no obvious pathologic changes were observed in the pcDNA3.1(+)-lipL21 immunized guinea pigs. The results showed that the protective effect with pathogenic strains of Leptospira was shared by LipL21 mediated through a plasmid vector. Consequently, these results indicated that the lipL21 DNA vaccine was a promising candidate for the prevention of leptospirosis.

Activation of nuclear factor kappaB and induction of inducible nitric oxide synthase by lipid-associated membrane proteins isolated from Mycoplasma penetrans.

BACKGROUND: This study was designed to investigate the potential pathogenicity of Mycoplasma penetrans (M. penetrans) and its molecular mechanisms responsible for the induction of iNOS gene expression in mouse macrophages stimulated by lipid-associated membrane proteins (LAMPs) prepared from M. penetrans. METHODS: Mouse macrophages were stimulated with M. penetrans LAMPs to assay the production of nitric oxide (NO). The expression of inducible nitric oxide synthase (iNOS) was detected by RT-PCR and Western blotting. The activity of nuclear factor kappaB (NF-kappaB) and the effects of pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-kappaB, on the production of nitric oxide and the expression of iNOS were also assessed in mouse macrophages treated with M. penetrans LAMPs by indirect immunofluorescence and Western blotting. RESULTS: M. penetrans LAMPs stimulated mouse macrophages to produce nitric oxide in a dose- and time-dependent manner. The mRNA and protein levels of iNOS were also upregulated in response to LAMP stimulation and inhibited by PDTC treatment. M. penetrans LAMPs were found to trigger NF-kappaB activation, a possible mechanism for the induction of iNOS expression. CONCLUSION: This study demonstrated that M. penetrans may be an important etiological factor of certain diseases due to the ability of M. penetrans LAMPs to stimulate the expression of iNOS, which is probably mediated through the activation of NF-kappaB.