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Biomedical subjects

J Etienne

Publications and source records attributed to J Etienne.

At least 271 records · Page 15Linked to original sources
PubMed1987

[Prognosis of surgically treated infectious endocarditis].

The prognostic factors in infective endocarditis patients who underwent surgery in the acute stage were evaluated from the records of 189 cases of native valve endocarditis operated upon between 1970 and 1986. Surgery had been performed before June 30, 1982 in 105 patients (group 1) and since July 1, 1982 in 84 patients (group 2). Group 2 only differed from group 1 in that the proportion of negative blood cultures was lower (13.7% vs 35%; p less than 0.01) and that of subjects older than 70 was higher (11.6% vs 5.7%; p less than 0.01). 105 patients (66 in group 1, 39 in group 2) had been operated upon during the first 6 weeks of antibiotic therapy ("early surgery"), while 84 patients (57 in group 1, 27 in group 2) had been operated upon between 7 and 24 weeks from the beginning of antibiotic therapy ("semi-early surgery"). Hospital mortality was 23.6% in group 1 (29/123) as against 10.6% in group 2 (7/66; p less than 0.05). The difference in mortality between the two groups was significant only in early surgery patients (33.3% vs 7.7%; p less than 0.01) and in patients operated upon while the infection was active with presence of pathogens in valve cultures (47.4% vs 7.7%; p less than 0.05). A study of mortality factors showed that the operative prognosis did not depend on the type of valve replacement performed or on the pathogen involved, but solely on the degree of cardiac failure before surgery. The post-hospital course was evaluated in group 1 patients followed up during 61.8 months on average.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Differentiation of human adipocyte precursors in a chemically defined serum-free medium.

Stromal-vascular cells from the inguinal fat tissue of human (age range 1.5 month-27 years), were able to undergo adipose conversion when cultured in a medium containing insulin, transferrin and triiodothyronine. Between 10 and 20 per cent of the cells changed their morphology and accumulated lipid droplets within 10 to 15 days. In most cultures, differentiated cells were present in clusters. These clustered cells were shown by indirect immunofluorescence to contain lipoprotein lipase (located in the Golgi region) and by histochemistry to contain glycerol-3-phosphate dehydrogenase. The occurrence of both enzymes was assessed directly by determining enzyme activities and the synthesis of triacylglycerol was demonstrated by incorporation of [U-14C]glucose into lipids. Foreskin fibroblasts did not display any of these phenotypes. The development of a serum-free, chemically defined medium for the differentiation of diploid adipocyte precursors from human should be of interest for the characterization of factors involved in the stimulation or inhibition of the differentiation process.

Adipose Tissue↗
PubMed1986

[Infectious endocarditis in France. Epidemiological characteristics].

The epidemiological characteristics of infective endocarditis in France were established in a one-year survey of strictly defined cases. The incidence of the disease is 18 cases per year and per million inhabitants, i.e. 970 cases annually. Patients are generally treated in Teaching Hospitals (80% of the cases were at the end of the hospitalization period). The predominant pathogens are the streptococci non groupable in 40.4% of the cases (group D in 21.9%) and the staphylococci (20.8%). Patients with group D streptococci endocarditis are the older ones (mean age: 60 years). Staphylococcal endocarditis occurs in younger patients (mean age: 43 years), especially after cardiac valve prosthesis or unrecognized cardiac valve disease, and it is the most serious form, with a 45% mortality rate (overall mortality rate: 21%). One quarter of the patients undergo a surgical operation.

Adolescent↗
PubMed1986

Adipose cell differentiation: evidence for a two-step process in the polyamine-dependent Ob1754 clonal line.

A subclone of preadipocyte Ob17 cells has been isolated (Ob1754 clonal line). Confluent Ob1754 cells treated with an inhibitor of spermidine and spermine synthesis, methylglyoxal bis(guanylhydrazone), were totally dependent upon putrescine addition for the expression of glycerol-3-phosphate dehydrogenase which behaved as a late marker of adipose conversion. Under these conditions, the early expression of lipoprotein lipase during growth arrest remained unchanged. Studies at the mRNA level showed that the expression of unidentified pOb24 and pGH3 mRNAs, which was parallel to that of lipoprotein lipase, is independent of polyamine addition whereas the late emergence of glycerol-3-phosphate dehydrogenase mRNA was putrescine-dependent and co-ordinated with the expression of pAL422 mRNA encoding for a myelin-P2 homologue [Bernlohr, Angus, Lane, Bolanowski & Kelly (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 5468-5472]. The appearance of lipoprotein lipase preceded DNA synthesis and post-confluent mitoses which were both putrescine-dependent and which took place before the appearance of glycerol-3-phosphate dehydrogenase. Thus the adipose conversion of Ob1754 cells involves the expression of at least two separate sets of markers which are differently regulated.

Adipose Tissue↗
PubMed1986

Beta-adrenergic stimulation enhances translocation, processing and synthesis of lipoprotein lipase in rat heart cells.

Cells isolated from newborn rat hearts were cultured for 10-14 days, and lipoprotein lipase activity was present in an intracellular and heparin-releasable pool. Treatment of the cultures with 10(-7) M isoproterenol for 3 min resulted in a 3-fold increase in heparin-releasable lipoprotein lipase and a concomitant decrease in residual cellular enzyme activity. Similar results were obtained by treatment with dibutyryl cAMP. Treatment with isoproterenol or dibutyryl cAMP for 2 h affected glycosylation of immunoadsorbable lipoprotein lipase, so that the ratio of [3H]galactose to [14C]mannose in the heparin-releasable enzyme increased from 3.8 (control) to 13.0 (isoproterenol-treated). The change in the ratio of the sugars in the cellular fraction of the enzyme was from 3.1 to 9.9. 2 h treatment with isoproterenol did not enhance new enzyme synthesis, as determined by incorporation of [3H]leucine into immunoadsorbable lipoprotein lipase. 24 h after addition of either isoproterenol or dibutyryl cAMP to the culture medium, stimulation of enzyme synthesis was demonstrated. The present results permit three effects of isoproterenol on lipoprotein lipase to be distinguished: stimulation of translocation from a cellular to heparin-releasable pool; enhanced processing of mannose residues and terminal glycosylation; stimulation of synthesis of enzyme protein.

Animals↗
PubMed1986

Characterization of rat adipose tissue lipoprotein lipase using a monospecific antibody.

An antibody to a highly pure enzyme preparation was developed to facilitate detailed studies of rat adipose tissue lipoprotein lipase regulation. Lipoprotein lipase was purified by heparin-Sepharose affinity chromatography followed by preparative isoelectric focusing. The enzyme migrated as a single broad band on SDS disc gel and two-dimensional gel electrophoresis with an apparent molecular mass of 67 000 and 62 000 Da, respectively. The amino acid composition of the purified rat enzyme was virtually identical to that of bovine milk. A major protein component with no lipase activity co-eluted with the enzyme from the affinity column, but was separated by the isoelectric focusing step. The molecular mass was slightly lower (58 000 Da) but the amino acid composition of this protein was similar to that of the enzyme. An antibody raised against the purified rat enzyme was highly potent and was effective in inhibiting rat heart lipoprotein lipase, but not the salt-resistant hepatic lipase. Analysis of crude acetone-ether adipose tissue preparation on SDS slab polyacrylamide gel coupled to Western blotting revealed five protein bands = (62 000, 56 000, 41 700, 22 500, 20 000 Da). Similarly, following affinity purification by immunoadsorption, the purified antibody reacted with five equivalent protein bands. Fluorescent concanavalin A binding data indicated that the 56 kDa band is a glycosylated form of lipoprotein lipase. Pretreatment of adipose tissue with proteinase inhibitors revealed that the lower molecular mass proteins (41 700 and 20 000 Da) were degradation products of lipoprotein lipase, and the 22 500 Da band could be accounted for by non-specific binding.

Adipose Tissue↗
PubMed1986

Maturation and secretion of lipoprotein lipase in cultured adipose cells. II. Effects of tunicamycin on activation and secretion of the enzyme.

The effects of N-linked glycosylation on the activation and secretion of lipoprotein lipase were studied in Ob17 cells. The cells were first depleted of any activity and enzyme content by cycloheximide treatment and of precursors of oligosaccharide chains by tunicamycin. The repletion of lipoprotein lipase content was studied in these cells maintained in the presence of tunicamycin after cycloheximide removal. During the repletion phase, the EC50 values of inhibition by tunicamycin (approx. 0.2 microgram/ml) of the incorporation of labeled glucose, mannose or galactose into trichloroacetic acid-insoluble material were found to be identical. Under these conditions, the rate of protein synthesis was maximally decreased by 30%. The results showed clearly that the recovery in lipoprotein lipase activity was parallel to the recovery in hexose incorporation, no activity being recovered in the absence of glycosylation. An inactive form of lipoprotein lipase from tunicamycin-treated cells was detected by competition experiments with mature active lipoprotein lipase for the binding to immobilized antilipoprotein lipase antibodies, as well as by immunofluorescence staining. SDS-polyacrylamide gel electrophoresis and Western blots of cellular extracts and of extracellular media, obtained after tunicamycin-treated cells were exposed to heparin, revealed a single immunodetectable Mr 52 000 protein, whereas a single Mr 57 000 protein was detected in control cells. Therefore, the results indicate that the acquisition by lipoprotein lipase of a catalytically active conformation is linked directly or indirectly to glycosylation. Despite this lack of activation, the lipoprotein lipase molecule was able to migrate intracellularily and to undergo secretion after heparin stimulation of the tunicamycin-treated cells.

Adipose Tissue↗
PubMed1986

Intracellular localization of lipoprotein lipase in adipose cells.

Subcellular localization of lipoprotein lipase has been examined in differentiated Ob17 adipose cells. No patent activity is detectable in carefully homogenized cells. All latent activity can be unmasked by disrupting membrane structures with neutral detergents. The sequestration of lipoprotein lipase in closed membrane structures is supported by experiments of immunotitration with anti-lipoprotein lipase antibodies and by experiments showing a full protection of the masked activity against proteolytic attack by trypsin. The intracellular distribution of lipoprotein lipase investigated by immunofluorescence staining and by isopycnic centrifugation indicates that a large proportion of the enzyme is located in the Golgi apparatus, in which the activation of the enzyme is likely to take place (C. Vannier et al. (1985) J. Biol. Chem. 260, 4424-4431). Altogether, the results are in favor of a localization of lipoprotein lipase in adipose cells as being typical of that of a secretory protein and underline the absence of lipoprotein lipase in the cell cytoplasm.

Adipose Tissue↗
PubMed1986

Characterization of the lipoprotein lipase in the functional pool of rat heart by immunoblotting.

Rat hearts were perfused with heparin for 2 min at 4 degrees C. The lipoprotein lipase activity in the perfusate was inhibited by antiserum to rat adipose tissue lipoprotein lipase. By immunoblotting, the lipoprotein lipase derived from the functional pool of the heart was found to be a protein with an apparent Mr of 69 000. After incubation of the perfusate at 37 degrees C for 24 h an immunologically reactive protein with an apparent Mr of 28 000 was found. This protein is not a physiological derivative of the enzyme but a degradation product.

Animals↗
PubMed1986

[Brain toxoplasmosis: from a case disclosing AIDS. Recall of diagnostic, developmental and therapeutic elements].

The authors are studying from a personal case revealing an AIDS, and from bibliographical cases, the treated evolution of toxoplasmic encephalitis in immuno-depressed patients and the elements of the diagnosis. They are insisting on the interest of the brain biopsy, and on the importance of the inflammatory brain oedema. The therapy consists on sulfamides and anti-oedematous drugs. They are thinking that the corticosteroids must be avoided. The evolution of cerebral lesions, seen on the repeated computed tomographies is often good but the prognosis remains bad according to the immuno-deficiency.

Acquired Immunodeficiency Syndrome↗
PubMed1986

[Lumbar osteomyelitis of actinomycotic or atypical mycobacterial origin?].

A case of lumbar epiduro-vertebral actinomycosis is related, in a 45 years old man, who was immuno depressed by an evolutive pulmonary sarcoidosis. 72 similar cases are reported in the literature. 50 of them are autopsied++. Clinically our patient looked like a Pott disease. The infection began probably in the kidney. The smear's diagnosis was actinomycosis, confirmed by the routine examination. An atypical mycobacteria, Mycobacterium xenopi was bacteriologically isolated twice in the pus. It was considered as the pathogen agent for 14 months. Actinomycosis was never identified bacteriologically. The patient responded to surgery and penicillin therapy. In view of the pathologic constatations and the therapeutic response, the final diagnostic was epiduro-vertebral actinomycosis. Mycobacterium xenopi acted probably as an "accompaning " germ in this case.

Actinomycosis↗
PubMed1985

Endogenous plasma lipoprotein lipase activity in fed and fasting rats may reflect the functional pool of endothelial lipoprotein lipase.

In this study, a correlation was sought between the circulating lipoprotein lipase activity and nutritional state in the rat. In fed rats, the plasma lipoprotein lipase activity was between 30 and 120 munits/ml, whereas after an overnight fast in restraining cages, the lipoprotein lipase plasma levels were between 280 and 500 munits/ml. The plasma lipoprotein lipase activity was inhibited by a specific high titre goat antiserum to rat lipoprotein lipase. No effect of fasting was seen on the plasma hepatic triacylglycerol lipase. 6 h after fasting, adipose tissue lipoprotein lipase decreased maximally, but plasma lipoprotein lipase was not changed and rose only after 16 h. Thus, it seems that most of the lipoprotein lipase activity in the fasting plasma was related to the 3-fold rise in lipoprotein lipase activity in the heart, which may represent total muscle lipoprotein lipase. The increase in heart lipoprotein lipase was due in part to an increase in the t1/2 of the enzyme from 1.2 to 2.9 h. To determine whether the high plasma levels in the fasting rats might result from impaired clearance of the enzyme by the liver, functional hepatectomy was carried out. 15 min after hepatectomy, plasma lipoprotein lipase rose up to 20-fold in fed and about 6-fold in fasting rats. Lipoprotein lipase activity extracted by the liver was calculated to be 30-60 munits/ml in the fed and 171-247 munits/ml plasma per min in fasting rats. An increase in lipoprotein lipase activity in extrahepatic tissues (heart, lung, kidney, diaphragm and adrenal) occurred 30 min after hepatectomy in fed rats. The increase in heart lipoprotein lipase was due to an increase in heparin-releasable fraction. Since no impairment of hepatic clearance of circulating plasma lipoprotein lipase was found, the high fasting plasma lipoprotein lipase activity may be related to an increase in enzyme synthesis, decreased enzyme turnover and an expansion of the functional pool in tissues such as the heart and probably muscle. The present findings indicate that measurement of endogenous plasma lipoprotein lipase can provide information with respect to the size of the functional pool under normal and pathological conditions.

Animals↗