Prediction of intensive care unit mortality: Interest of serum lactates.

INTRODUCTION: Many prognostic indices have been developed to assess clinical status and predict the probability of death in the intensive care unit (ICU) but none have perfect sensitivity or specificity. AIM: To evaluate the prognostic value of admission lactate in patients admitted to ICU. METHODS: A cohort, observational, prospective study was carried out in the intensive care unit (ICU) of Mongi Slim Hospital, la Marsa, over 12 months period. Arterial blood lactate (ABL) was measured in ICU admission (H0), then 6 hours (H6), 12 hours (H12), 24 hours (H24) and 48hours (H48) after admission. Prognostic scores were calculated 24 hours after the admission. We also recorded biological data, hemodynamic parameters, and the evolution during the stay in intensive care. Primary endpoint was ICU mortality. RESULTS: We included 135 patients. The average age was 47.22 ± 16.88 years with a sex-ratio of 1.75. ICU mortality was 48%. The mean ABL at admission was 3.05 ± 2.63 mmol/l, higher in the dead group with a statistically significant difference. Prognostic value of lactate at admission was less powerful than severity indices in this study but remains excellent with an AUC >0, 7 defining « cut-off ¼ values with a good sensitivity and specificity. In multivariate analysis, initial lactate > 2 mmol/l was found to be an independent predictive factor of ICU mortality with an Odd Ratio [IC 95%] =1.16 [1.07 - 3.6]; p=0.04. CONCLUSIONS: Monitoring lactatemia in ICU could allow better identification of patients at high risk of death and the reassessment of therapeutic efficacy.

High-Dimensional Single-Cell Analysis Identifies Organ-Specific Signatures and Conserved NK Cell Subsets in Humans and Mice.

Natural killer (NK) cells are innate lymphoid cells (ILCs) involved in antimicrobial and antitumoral responses. Several NK cell subsets have been reported in humans and mice, but their heterogeneity across organs and species remains poorly characterized. We assessed the diversity of human and mouse NK cells by single-cell RNA sequencing on thousands of individual cells isolated from spleen and blood. Unbiased transcriptional clustering revealed two distinct signatures differentiating between splenic and blood NK cells. This analysis at single-cell resolution identified three subpopulations in mouse spleen and four in human spleen, and two subsets each in mouse and human blood. A comparison of transcriptomic profiles within and between species highlighted the similarity of the two major subsets, NK1 and NK2, across organs and species. This unbiased approach provides insight into the biology of NK cells and establishes a rationale for the translation of mouse studies to human physiology and disease.

Histopathological and ultrastructural changes experimentally induced by bee venom in seminiferous epithelium via structural-functional alteration of Sertoli cells.

We tested here the ability of bee venom (BV) to interfere with spermatogenesis in rats in two experimental conditions. The histopathological changes were assessed with brightfield microscopy using a novel staining technique, based on methylene blue, orange G and ponceau xylidine. Transmission electron microscopy was also used to identify fine subcellular changes. BV injection for 30days in daily doses of 700µg BV/kg resulted in reducing testicular weight, along with significant larger diameters of seminiferous tubules and reduced number of Sertoli cells (SCs). SCs were vacuolated, detached from the basement membrane, many necrosed, leading to the basement membrane denudation. Germ cells layers were separated by empty spaces conferring a rarefied aspect to the tissue, and spermatids were detached into lumen. Thus, the seminiferous epithelium was significantly thinned. Many Leydig cells (LCs) were in a necrotic state, with disrupted plasma membrane and without smooth endoplasmic reticulum. The acute treatment with a single LD50 of 62mgBV/kg, was followed by focal disruptions of the basement membrane and localized areas of necrosis, mainly affecting the SCs. Most of the observed SCs as well as some spermatogonia were highly vacuoled, empty spaces being observed within the epithelium. The SCs count was significantly decreased. Spermatids had also the tendency of separation from the SCs, and the significant larger diameter of the tubules found was associated with a thicker epithelium. Many LCs were necrosed, with disrupted plasma membrane, swollen mitochondria, no endoplasmic reticulum and implicitly showing rarefied cytoplasm. We concluded that BV was a testicular toxicant affecting both the LCs and the seminiferous tubules. The SCs cells represented the primary target site of BV whose effects were next extended upon the germ cells. In all cells, BV triggered unspecific degenerative changes that could impaire spermatogenesis. The present study also proposes an alternative staining technique very useful in assessing the histopathological aspects of spermatogenesis.

[Factors associated to maternal mortality among preeclamptic parturients. About 55 cases]. / Facteurs associees a la mortalite maternelle chez les preeclamptiques: a propos de 55 cas.

Retrospective study about 55 preeclamptic parturients. Data was collected from the medical files of the patients hospitalized during two consecutive years. Admittance of preeclamptic women in the intensive care unit was 6,37 % (55/689). Mortality rate was 11% (6 deaths). Complications associated with the maternal death were renal failure, disseminated intravascular coagulopathy and Hemorrhagic shock after subcupsular liver hematoma. Advanced maternal age is a factor associated to maternal mortality. All these risk factors of death may be avoided if adequate management was performed.