Objective To study the clinical characteristics of healthcare-associated pneumonia (HCAP).Methods A retrospective cohort study was conducted on consecutive hospitalized pneumonia cases from January 2007 through April 2008.Results HCAP group of 75 patients was compared with 133 patients of community-acquired pneumonia (CAP) and 76 patients of hospital-acquired pneumonia (HAP). Most of HCAP patients had a history of recent hospitalization (47 cases), clinical IV infusion (27 cases), and prior chemotherapy or antibiotic therapy (27 cases). Underlying diseases were identified in 71 (94.7%) of HCAP patients, significantly higher than that in CAP group (37.6%, P<0.01). Positive sputum culture in CAP, HCAP and HAP was 22.6%, 56.9%, 77.6% respectively. Antibiotic resistance of bacteria in HCAP (71.43%) and HAP (80%) was comparable (P>0.05). Initial antibiotic therapy was effective in 47 (62.6%) cases of HCAP. Only 52.9% of the identified pathogens were sensitive to initial antibiotic therapies. The mortality of HCAP (12%) was similar to HAP (23%, P>0.05), but significantly higher than CAP (3%, P<0.05).Conclusions HCAP is a common type of pneumonia, which is characterized by more resistant pathogens, higher mortality, more comorbidities and poor outcomes. Antibiotic therapy should cover the hospital acquired bacterial pathogens.

ObjectiveTo investigate the role of lymphocyte apoptosis and endoplasmic reticulum stress (ERS) on the development of sepsis and their association with the prognosis of sepsis patients.Methods A prospective cohort study was conducted. Seventy septic patients admitted to intensive care unit (ICU) of Shanghai East Hospital of Tongji University were enrolled. Blood samples were collected on days 1, 3 and 7 to measure percentage of circulating apoptotic lymphocyte with flow cytometry analysis. The relative expressions of endoplasmic reticulum specific glucose regulated protein 78 (GRP78) mRNA and transcription factor CHOP mRNA were measured by real-time reverse transcription-polymerase chain reaction (RT-PCR). The correlation between CHOP mRNA expression and percentage of circulating apoptotic lymphocyte was analyzed by Spearman relative analysis. The patients were divided into death (n = 23) and survival subgroups (n = 47). Twenty healthy volunteers during the same period were selected as the healthy control group.Results① Rate of lymphocyte apoptosis: compared with healthy control group [(2.86±0.66)%], septic patients, either survival or death subgroup, exhibited higher rate of lymphocyte apoptosis on days 1, 3 and 7 [survival subgroup: (12.44±4.43)%, (8.57±3.38)%, (6.78±3.35)%; death subgroup: (14.42±2.01)%, (11.32±2.53)%, (8.87±3.62)%, allP< 0.01], and it was obvious on day 1, and the phenomenon became less marked gradually. The rate of circulating apoptotic lymphocytes did not differ between the death and survival subgroups on day 1, but there was a significant difference in the rate on day 3 and day 7 (bothP< 0.05).② The expression of CHOP mRNA (2-ΔΔCt):compared with that in healthy controls [(2.56±1.09)×10-3], CHOP mRNA expression was increased on days 1, 3 and 7 in septic patients [survival subgroup: (5.83±1.96)×10-3, (4.24±1.60)×10-3, (4.15±1.64)×10-3, death subgroup:(37.20±20.70)×10-3, (18.80±13.90)×10-3, (9.28±7.78)×10-3, allP< 0.01], and it was more obvious in the death subgroup, as it was increased by 6.38, 4.43, and 2.24 folds (P values was 0.000, 0.000, and 0.001), but it decreased rapidly in death subgroup.③ The expression of GRP78 mRNA (2-ΔΔCt): compared with healthy controls [(3.31±2.04 )×10-3], the expression of GRP78 mRNA in both survival and death subgroups increased in septic patients on day 1 [(5.83±2.00)×10-3, (11.30±6.48)×10-3, bothP< 0.01], and they decreased subsequently. The expression of GRP78 mRNA in the survival subgroup declined to the levels of the healthy control group on day 3 and day 7 [3 days: (3.99±1.60)×10-3, 7 days: (3.30±1.35)×10-3, bothP> 0.05], and GRP78 mRNA expression in the death subgroup was gradually lowered, but it was still higher than that in the healthy control group [3 days: (7.27± 3.64)×10-3, 7 days: (5.23±1.94)×10-3, bothP< 0.01].④ Spearman relative analysis showed that the expression of CHOP mRNA was positively correlated with the rate of lymphocyte apoptosis (r = 0.414,P = 0.000 ).Conclusion The increase in the rate of lymphocyte apoptosis and activation of ERS play an important role in the development of sepsis, and it is associated with worse outcome in the septic patients.

For multicellular organisms, cell-cell communication is essential to numerous biological processes. Drawing upon the latest development of single-cell RNA-sequencing (scRNA-seq), high-resolution transcriptomic data have deepened our understanding of cellular phenotype heterogeneity and composition of complex tissues, which enables systematic cell-cell communication studies at a single-cell level. We first summarize a common workflow of cell-cell communication study using scRNA-seq data, which often includes data preparation, construction of communication networks, and result validation. Two common strategies taken to uncover cell-cell communications are reviewed, e.g., physically vicinal structure-based and ligand-receptor interaction-based one. To conclude, challenges and current applications of cell-cell communication studies at a single-cell resolution are discussed in details and future perspectives are proposed.
Animals ; Cell Communication ; Humans ; RNA-Seq ; Single-Cell Analysis ; Transcriptome