Biomedical subjects

Jean-Marc Olivot

Publications and source records attributed to Jean-Marc Olivot.

3 recordsLinked to original sources

PubMed2006

Ischemia-modified albumin in acute stroke.

BACKGROUND: Ischemia-modified albumin (IMA)is a new biological marker of ischemia. Previous studies have found increased serum IMA levels after myocardial ischemia, but no study has investigated the possibility that stroke modifies IMA blood levels. MATERIALS AND METHODS: We studied 118 consecutive patients presenting within 3 h of the onset of an acute neurological deficit [84 brain infarctions (BI), 18 brain hemorrhages (ICH) and 16 transient ischemic attacks lasting less than 1 h or epileptic seizures]. Serum samples were obtained for all patients at initial presentation and repeated only in patients with stroke at 6, 12 and 24 h. IMA was measured by the albumin-cobalt-binding test (Ischemia Technologies, Denver, Colo., USA). RESULTS: The initial median IMA (bootstrap 95% confidence interval, CI) was 83 U/ml (79-86) and 86 U/ml (75-90) in patients with BI and ICH, respectively (p = 0.76), and was 73 U/ml (58-79) in others (p = 0.003 compared with BI, and p = 0.017 with ICH). Baseline IMA levels correlated with the National Institutes of Health Stroke Scale [Spearman correlation coefficient: 0.34 (p = 0.002) in BI, 0.61 (p = 0.008) in ICH]. During the first 24 h, IMA levels increased in BI patients (median, 9.1%; bootstrap 95% CI, 5.2-11.5), whereas no change was observed in ICH patients (median, 1.2%; bootstrap 95% CI, -7.8 to 6.8). CONCLUSIONS: IMA blood levels may be a biomarker for early identification of acute stroke. Further studies are required to investigate the role of IMA in the early detection of acute stroke.

Acute Disease↗

PubMed2004

Soluble thrombomodulin and brain infarction: case-control and prospective study.

BACKGROUND AND PURPOSE: Increased soluble thrombomodulin (sTM) concentration has been associated with recurrent coronary events, whereas in one prospective study it predicted fewer first-ever coronary events. One study found no relationship between brain infarction (BI) and sTM levels. Among all subjects of the Etude du Profil Génétique de l'Infarctus Cérébral (GENIC) cohort and those free of previous vascular history, we investigated the relationship between sTM level and BI risk, and among cases, its relationship with BI prognosis. METHODS: Patients with BI (n=492) were consecutively recruited from 12 centers. Hospital controls without a history of stroke (n=492) were individually matched for age, sex, and center. Blood samples were collected after hospitalization. Determination of sTM levels was centralized in a single laboratory. RESULTS: Soluble TM concentration significantly increased with age and hypertensive status, but was similar in cases and controls. With analyses restricted to 278 pairs of subjects with no previous vascular history, sTM concentration >59.6 microg/L (second and third tertiles compared with the first) was associated with fewer first-ever BI (adjusted odds ratio of 0.56 (95% CI, 0.35 to 0.89; P=0.014). Among the cases, increased sTM concentration was associated with a higher death rate after a median follow-up of 5.2 (1.4 to 6.4) years. The adjusted hazard ratio per 1 SD of sTM concentration increase (34.2 microg/L) was 1.19 (95% CI, 1.02 to 1.39; P=0.028). CONCLUSIONS: Increased sTM concentration may be protective against BI in subjects with no previous vascular disease, whereas it may predict a fatal outcome in patients who have already had a BI. Consequently, sTM levels should be interpreted according to vascular history.

Adult↗

PubMed2002

Human endothelial cells selectively express large amounts of pancreatic-type ribonuclease (RNase 1).

Pyrimidine-specific ribonucleases are a superfamily of structurally related enzymes with distinct catalytic and biological properties. We used a combination of enzymatic and non-enzymatic assays to investigate the release of such enzymes by isolated cells in serum-free and serum-containing media. We found that human endothelial cells typically expressed large amounts of a pancreatic-type RNase that is related to, if not identical to, human pancreatic RNase. This enzyme exhibits pyrimidine-specific catalytic activity, with a marked preference for poly(C) substrate over poly(U) substrate. It was potently inhibited by placental RNase inhibitor, the selective pancreatic-type RNase inhibitor Inhibit-Ace, and a polyclonal antibody against human pancreatic RNase. The enzyme isolated from medium conditioned by immortalized umbilical vein endothelial cells (EA.hy926) possesses an amino-terminal sequence identical to that of pancreatic RNase, and shows molecular heterogeneity (molecular weights 18,000-26,000) due to different degrees of N-glycosylation. Endothelial cells from arteries, veins, and capillaries secreted up to 100 ng of this RNase daily per million cells, whereas levels were low or undetectable in media conditioned by other cell types examined. The corresponding messenger RNA was detected by RT-PCR in most cell types tested so far, and level of its expression was in keeping with the amounts of protein. The selective strong release of pancreatic-type RNase by endothelial cells suggests that it is endowed with non-digestive functions and involved in vascular homeostasis.

Amino Acid Sequence↗