Biomedical subjects

J Bismuth

Publications and source records attributed to J Bismuth.

At least 19 recordsLinked to original sources

PubMed2004

[Nocardiosis--is it frequently observed after the introduction of new immunosuppressive agents in renal transplantation?].

In our series of 1374 renal transplantations performed between February 1970 and December 2002, we observed 6 cases of infection due to Nocardia asteroides. There were 4 males and 2 females, aged 49.8 +/- 12 years (29 to 63 years). One patient received his first transplantation and the 5 others retransplants. Three patients had PRA > 80%, one 28% and one 40%. One patient was diabetic and two had HCV infection. Two of 6 patients experienced acute rejection episodes. Nocardiosis localisation was pulmonary in 5 cases, cerebral in two and mediastinal in one. All patients recovered after reduction of immunosuppression and appropriate antibiotherapy with trimethoprim-sulfamethoxasole (TMP-SMX). When we analyzed the role of immunosuppression, we observed that only two cases were observed in the 933 recipients transplanted between 1985 and 2002 and receiving cyclosporin, contrasting with 4 cases among 174 recipients transplanted between 1996 and 2002 and receiving tacrolimus. Our data suggest that high immunologic risk patients, heavy immunosuppression, and perhaps tacrolimus-based immunosuppression are risk factors of nocardial infection. Early diagnosis of this severe infection, reduction of immunosuppression and appropriate therapy with TMP-SMX resulted in complete recovery in all our patients.

Adrenal Cortex Hormones↗

PubMed2004

[Sequential protocols with thymoglobuline and delayed introduction of calcineurin: effects on renal function in renal transplant recipients with non immunological risk and low risk of delayed graft function].

Induction therapy with thymoglobuline significantly decreases the risk of acute rejection, particularly in high immunological risk patients, in combined transplantations and in pediatric renal transplantation. After the introduction of cyclosporin in the 1980's and the recognition of its potential nephrotoxicity, induction therapy with delayed introduction of cyclosporin (sequential protocols) have became very popular in many transplant centers and are now used even in low-immunological risk patients. The aim of the present study was to assess the recovery of renal function in low-immunological risk patients receiving a sequential protocol versus those receiving a calcineurin inhibitor at day 1. Among patients receiving their first transplant in our center between January 1999 and June 2000, we selected 72 recipients with no immunological risk and no risk of delayed graft function (DGF). 35 patients (group I) have received a sequential protocol whereas 37 patients (group II) have received a calcineurin inhibitor (Neoral or prograf) at day 1. We analysed creatinine reduction ratio, 24-hour creatinine excretion on post-transplant day 2, and serum creatinine and creatinine clearance at day 15, 30, 45, 60 and 90 post-transplant. There was no difference between groups concerning demographic, immunological or surgical parameters. The percentage of patients with immediate graft function was similar between the two groups (10 versus 9). The number of patients requiring dialysis in the first post-transplant week was also similar (8/35 versus 6/37). The day serum creatinine reached 200 micromol/l was 15 +/- 11 versus 14 +/- 12 in groups I and II respectively. Serum creatinine and creatinine clearance were similar at all time intervals. CMV disease was significantly higher in the group 1 (42% versus 18.5%; p < 0.005). Our data suggest that in patients with low immunological risk and low-risk of DGF, introduction of calcineurin inhibitors as early as the post-transplant day 1 is not deleterious for renal function recovery. These data should be confirmed by a prospective randomised trial.

Adult↗

PubMed2003

[Thyreotoxic periodic paralysis. A cause of pseudo-paralysing hypokalemia that should not be ignored in Caucasians].

INTRODUCTION: Despite its rare occurrence in Caucasians, thyreotoxic periodic paralysis should be evoked in young male Caucasians presenting with episodes of pseudo-paralytic hypokalemia. OBSERVATION: A 37 year-old Caucasian was admitted in intensive care for an acute episode of hypotonic tetraplegia and hypokalemia during which laboratory tests revealed hyperthyroidism due to Basedow's disease. The clinical course was rapidly favourable after a small dose of intravenous potassium. Antithyroid treatment avoided any new occurrence of similar episodes. DISCUSSION: In Caucasians, sporadic acute paralysis with hypokalemia requires testing for hyperthyroidism. Though it is well know that hypokalemia results from potassium intracellular shift, the underlying mechanism remains poorly elucidated. Treatment includes potassium administration with caution and/or beta blockers but the specific treatment is that of hyperthyroidism.

Adult↗

PubMed2001

[Lipid lowering treatment of patients with atherosclerotic disease of the lower extremities].

Patients with critical peripheral ischaemia have a significant mortality rate of up to 50% within 4-5 years of surgical vascular reconstruction. This poor survival rate is due to concomitant coronary and cerebrovascular atherosclerotic disease. Large randomised trials have shown that dyslipidaemia is easily modifiable in patients both with and without established coronary artery disease, with significant reductions in cardiovascular morbidity and mortality. Although none of these trials directly measured peripheral vascular status, there is every indication that conclusions submitted for patients with ischaemic heart disease can be translated to patients with peripheral arterial disease (PAD). The object of this review was therefore to divulge the current evidence available, which supports active treatment of dyslipidaemia in patients with PAD.

Arteriosclerosis↗

PubMed2001

Angioplasty for the treatment of buttock claudication caused by internal iliac artery stenoses.

A case of buttock claudication due to isolated internal iliac artery stenoses is presented. Although ankle systolic pressure at rest was within normal limits and distal pulses were palpable, an angiogram demonstrated severe stenoses. A computed tomography scan showed no spinal stenosis. The patient was successfully treated with angioplasty. This diagnosis may be elusive if ankle pressure or distal pulses are normal, thereby directing the clinician's suspicion away from vascular pathology.

Aged↗

PubMed2001

Real-time spatial compound imaging improves reproducibility in the evaluation of atherosclerotic carotid plaques.

Compound imaging has the ability of reducing speckle and clutter artifacts demonstrated in in vitro studies compared to conventional, single-angle imaging. We investigated intra- and interobserver agreement of 38 outlines of carotid artery plaque images acquired by these techniques, by measuring the overlapping area after repeated outlines. In general, both techniques showed good agreement. When considering the images with poorest overlap, compound imaging had a significant advantage over conventional imaging regarding both intra- and interobserver agreement. The interobserver variation for the overlapping area after two outlines was 20% for conventional technique and 10% for compound. The interobserver variation of the gray scale median value (GSM) for conventional technique ranged from -32 to +20 and from -6 to +6 for compound. Likewise, the coefficient of repeatability for the GSM value was 13 for conventional imaging and three for compound imaging, and interobserver variation for the GSM value for the overlapping area was 34% and 9% for conventional and compound technique. In conclusion, compound imaging improves intra- and interobserver agreement and reduces interobserver variation in the GSM value in a clinical setting.

Aged↗

PubMed2001

The lack of cardiovascular risk factor management in patients with critical limb ischaemia.

AIM: to define the level of management of cardiovascular risk factors in patients treated for critical limb ischaemia in a vascular surgical setting. MATERIALS AND METHODS: retrospective review of all (n =147) patients operated on for critical lower extremity ischaemia in 1998. We included pre- and postoperative cardiac events. RESULTS: only eight (5%) (95% CI; 2-9) were on lipid lowering treatment and 58 (39%) (95% CI; 31-47) using acetylsalicylic acid. CONCLUSIONS: only a minority of patients operated on for CLI were receiving adequate cardiovascular risk factor modification.

Aged↗

PubMed2000

Intraluminal calcification of the abdominal aorta.

A patient who had no evidence of atherosclerotic disease and had never been hypertensive, presented with symptoms usually associated with gallstone disease. A large intraluminal calcification in the juxtarenal aorta was found to be the probable cause of these symptoms. The aorta was otherwise free of atherosclerotic changes. Although it could not be identified with certainty, this calcification could have developed secondary to a single ulcerated atheroma.

Aorta, Abdominal↗

PubMed1998

Effects of adrenal steroid hormones on mitochondrial maturation during the late fetal period.

In the present work, we described the perinatal changes in mitochondrial maturation that contribute to metabolic development in the rat kidney. We focused on cytochrome-c oxidase activity and gene expression from the last three days of gestation to one day after birth. The role of adrenal steroids in the development of cytochrome-c oxidase expression and of mitochondrial DNA content was also investigated by studying the effects of fetal adrenalectomy. During the perinatal period, the developmental pattern of the cytochrome-c oxidase enzymatic complex exhibited parallel increases in transcript levels, protein content and enzyme activity, suggesting a transcriptional regulation of this enzyme. Adrenalectomy led to a decrease in fetal kidney cytochrome-c oxidase messengers and mtDNA content while administration of dexamethasone restored normal levels. In contrast, mtDNA content was unchanged in liver and heart after adrenalectomy whereas levels of cytochrome-c oxidase transcripts were controlled by adrenal steroids in liver but not in heart. These results indicate that adrenal steroid hormones contribute to the regulation of perinatal maturation of mitochondria in rat kidney and that these hormones are involved in the fetal mitochondrial biogenesis in a tissue-specific manner.

Adrenal Cortex Hormones↗

PubMed1996

Effect of hyperglycemia on the polyol pathway in rat kidney during the perinatal period.

The activity of the polyol pathway was studied in developing rat kidney. For this purpose, sorbitol content, aldose-reductase activity and sorbitol-dehydrogenase activity were determined in papilla from fetuses and 24-h-old neonates. After birth, no significant difference was observed in sorbitol content, whereas sorbitol-dehydrogenase activity decreased and aldose-reductase activity doubled. Changes in aldose-reductase activity were due to an increased number of enzymatic sites but not with a change in affinity. Low levels of sorbitol were found in fetal and neonatal medulla together with low levels of urine osmolarity. In neonates, sorbitol contents were tenfold lower than in the adult, probably as a result of a lower affinity and a lower number of enzymatic aldose-reductase sites. Attempts to increase the activity of polyol pathway in fetal kidney were made by means of hyperglycemic animals; this approach resulted in an increase of aldose-reductase activity without any change in sorbitol content. Our results indicate that, in fetal and neonatal kidneys, aldose-reductase activity is probably not the limiting factor for sorbitol synthesis; another parameter, such as the availability of NADPH, might explain the low efficiency of the polyol pathway during the perinatal period.

Aldehyde Reductase↗

PubMed1995

Perinatal maturation of rat kidney mitochondria.

In the rat kidney, NaK-ATPase activity increased between days 19 and 20 of gestation (+50%) and between 1 and 24 h after birth (+20%), requiring an increased energy supply. In order to determine whether mitochondrial changes were involved, renal mitochondrial development was investigated from day 19 of gestation to 1 day after birth. Slot-blot analyses of mitochondrial-DNA/nuclear-DNA ratio and determination of citrate synthase activity showed a doubling in the mitochondrial pool between days 19 and 20 of gestation. In isolated mitochondria, oxygen consumption remained unchanged between days 19 and 20 of gestation, and then it was enhanced between days 20 and 21 of gestation (+70%) and between 1 and 24 h after birth (+50%). We also focused on one of the respiratory-chain complexes, ATP synthase, and measured its activity and content during the perinatal period. We demonstrated increases in both activity and content of ATP synthase between days 20 and 21 of gestation and between 1 and 24 h after birth, thus suggesting that changes in ATP synthase activity are ascribed to an increase in the mitochondrial density of ATP synthase complexes. Moreover, the mitochondrial ATP/ADP ratio only increased between 1 and 24 h (+90%), indicating a critical step in the renal respiratory-chain maturation at that time. We therefore conclude that the postnatal enhancement of renal mitochondrial oxidative capacity might depend on protein synthesis de novo and on changes in the adenine nucleotide concentrations.

Adenine Nucleotides↗

PubMed1995

Antibodies against restricted sequences in human c-ErbA hinge domain recognize differentially natural mammalian alpha- or beta-type triiodothyronine receptors and interfere differently with hormone binding.

In our first report, rabbit antibodies directed to recombinant polypeptides of human alpha-type c-ErbA sequences recognized natural triiodothyronine (T3) receptors (TR) in adipocytes (mouse Ob 17 cell line) but not in liver (mouse, rat). Moreover, some of them, directed to the sequence 150-228, markedly interfered with hormone binding to adipocyte T3 receptors. We now raised antibodies against shorter synthetic peptides within this alpha-type 150-228 c-ErbA sequence, which encompasses part of the hinge (D) domain and N-terminus of the E domain (alpha-150-166 and alpha 172-191) and against a beta-type c-ErbA sequence (beta 204-220 aligned on alpha 150-166, and differing by eight amino acids). Our present antibodies, which bear the expected c-ErbA alpha- or beta-type specificity, immunoprecipitated the TR in nuclear extracts, with a different pattern between tissues: exclusive precipitation by anti-c-ErbA alpha antibodies in Ob 17 adipocytes; large but non-exclusive precipitation by anti-cErbA beta antibodies in rat or mouse liver, which also expresses some alpha-type TR. This pattern of discriminative immunoprecipitation, also obtained in parallel analysis using our previously described antibodies to other c-ErbA alpha or beta sequences (anti-alpha 144-162, anti-alpha 1 403-410 and anti-beta 62-82), roughly verifies results of c-erbA mRNA expression in these tissues. Slight differences appeared in the extent of alpha-type TR recognition by antibodies directed to alpha 172-191, whether TR were liganded or not to T3 before antibody addition. This evokes a different conformation of this region after hormone binding. Most interestingly, these anti-alpha 172-191 antibodies lowered the Ka for T3 and extensively dissociated the adipocyte T3-TR complexes; they interfered poorly with the binding of T3 in liver nuclear extracts. This strongly supports the concept that internal sequences in c-ErbA alpha, more precisely in a restricted C-terminal part of the D domain, are necessary for efficient T3 binding, which also need the C-terminal part of domain E.

Amino Acid Sequence↗

PubMed1993

Increase of adipose differentiation by hypolipidemic fibrate drugs in Ob 17 preadipocytes: requirement for thyroid hormones.

The action of hypolipidemic fibrate drugs (HFD) (clofibrate, bezafibrate, fenofibrate) was studied in relation to thyroid hormone (TH) action in the TH-sensitive Ob 17 preadipocyte cells which require an early presence of TH for terminal differentiation. HFD markedly amplified the adipose differentiation and the development of several lipogenic enzymes, thus accelerating their appearance after cell growth arrest. This amplifying action could be obtained whatever the time of drug addition to the cells and required the continuous presence of the drug. HFD action was strictly dependent on the presence of TH. Within the active concentration range (0.01-0.25 mM) in serum-containing medium, HFD moderately down-modulated the nuclear TH receptor level (and c-erb alpha mRNA abundance), this being additive to the known maximal but partial down-regulation provoked by TH. The results strengthen the TH obligatory role for Ob 17 cell differentiation and give arguments against a TH-like role of HFD. In this cell line, HFD mainly behave as amplifiers for the expression of lipogenic phenotypes in already committed cells.

Adipose Tissue↗

PubMed1993

Effect of maternal hyperglycemia on NaK ATPase activity in fetal rat kidney.

The effect of moderate hyperglycemia on renal ATP production and ATPase activity of rat fetus was investigated using the experimental procedure of maternal continuous infusion of glucose during the last 5 days of gestation. Glucose-infused mothers and their fetuses showed a high level of glycemia (8.8 and 5.5 mM, respectively) and a high level of insulinemia (3 times higher than in controls). No change in either ATP or ADP concentration was detectable but an increase in NaK ATPase activity occurred without any change in Mg ATPase activity. These modifications should be the result of an enhanced Na/glucose cotransport leading to an enhanced extrusion of Na at the basolateral membrane. These results indicate that immature kidney is able to increase NaK ATPase activity to maintain Na homeostasis.

Adenosine Triphosphatases↗

PubMed1992

Retinoic acid decreases nuclear triiodothyronine receptor expression and impairs an early step of adipose differentiation in the thyroid hormone-sensitive mouse Ob 17 preadipocyte cell line.

In the murine preadipocyte cell line Ob 17, T3 is known to be necessary at an early step of adipose differentiation for the expression of late phenotypes [lipogenic enzymes such as malic enzyme, glycerol-3-phosphate dehydrogenase (GPDH), etc.] and not necessary for the expression of lipoprotein lipase (LPL), which emerges earlier, at growth arrest. These cells contain nuclear T3 receptors, which mainly belong to products of the c-erbA alpha gene and are down-regulated by T3. In this work, retinoic acid (RA) added to Ob 17 cells at growth arrest impaired morphological differentiation and the development of both late (malic enzyme and GPDH) and early (LPL) phenotypes regardless of whether T3 was added. T3 sensitized the cells to the inhibitory action of RA; the ED50 for GPDH activity was shifted from 0.5 microM to 3 nM in cells cultured with 1.5 nM T3. Later addition of RA (6 days after growth arrest) did not inhibit the differentiation. RA also brought out a marked and fast decrease in nuclear T3 receptors. This was observed whatever the stage of cell development and related to both a rapid decrease in the relative abundance of c-erbA alpha-related mRNA species and an increased disappearance rate, suggesting the involvement of pre- and posttranslational events. RA and T3 acted additively in decreasing the T3 receptor and c-erbA alpha mRNA levels. The effects of RA on T3 receptors were rapidly reversed after RA withdrawal; the reversal was large (75%) when RA was introduced at growth arrest and total when introduced later. The cell sensitivity to RA, considering the T3 receptors, was higher at growth arrest (ED50 for RA, 0.2 and 1.5 microM in assays with RA added at growth arrest and 5 days later, respectively). The results suggest intricated regulatory pathways between RA and T3 at an early step of adipose differentiation and also suggest that among different mechanisms through which RA may impair this differentiation, a decreased level of nuclear T3 receptors at an early period should play a role.

ATP Citrate (pro-S)-Lyase↗

PubMed1991

Developmental and thyroidal regulation of the nuclear T3 receptors/c-erb A oncogene products in the Ob 17 preadipocyte cell line.

In a thyroid hormone-sensitive mouse preadipocyte cell line (Ob 17), the concentration of nuclear T3 receptors increases during differentiation in an insulin-independent manner and decreases by 50-60 p.cent after medium supplementation with physiological concentrations of T3. The down-regulation of T3 receptors implies both quantitative and qualitative changes. The preadipocyte T3 receptors were previously reported to be heterogeneous in gel filtration and in their reactivity towards rabbit antibodies raised against large erb A alpha peptides. This report shows that the receptor heterogeneity is not modified during cell development, whereas T3 mainly depletes the receptor species that are both the most retarded in gel filtration and preferentially recognized by c-erb A alpha-specific antisera. The c-erb A alpha-related T3 receptors which predominate in preadipocytes, are thus probably mainly involved in receptor depletion by T3. A similar T3 receptor half-life of 12-13 h was estimated after cycloheximide addition to cells at confluence or later in the differentiation phase with or without T3. This suggested that development, or T3, might have mainly affected the production of T3 receptors. In Northern hybridization studies, using alpha- or beta-type c-erb A cDNA probes containing the entire coding sequence, only alpha-type mRNAs were detected with a predominant band of 2.8 kbases and two fainter bands of about 5.5 and 6.0 kbases. The alpha-type mRNA abundance relative to beta-actin significantly increased during differentiation and decreased after T3 addition.

Adipose Tissue↗

PubMed1991

Effect of lipid diet on mitochondrial palmitoyl-l-carnitine oxidation in kidney at postnatal development.

Oxygen consumption (VO2) and beta-hydroxyacyl-CoA dehydrogenase (beta OAC) activity were measured in isolated mitochondria of developing rat kidney from late fetal to adult age. In the presence of palmitoyl-L-carnitine, VO2 consumption was higher in suckling than in adult rats while beta OAC activity rose during the postnatal period and declined after weaning. During postnatal development, the high level of mitochondrial fatty acid oxidation was linked to the high level of fatty acid supply and any change in lipid diet altered mitochondrial fatty acid oxidation. By contrast at adult age, a high fat diet did not change either mitochondrial fatty acid oxidation or beta OAC activity measured in two nephron structures (PCT and mTAL). Dietary lipids seem to play an important role in the evolution of mitochondrial fatty acid oxidation in developing rat kidney.

3-Hydroxyacyl CoA Dehydrogenases↗

PubMed1991

[Retinoic acid reduces the expression of nuclear receptors of triiodothyronin and inhibits an early stage of the differentiation in the Ob 17 preadipocytic strains].

In the murine preadipocyte cell line Ob 17, T3 is known as being necessary at an early step of adipose differentiation for the expression of late markers, but not necessary for the expression of early markers. These cells contain nuclear T3 receptors (RT3) which are products of c-erb A alpha proto oncogenes, and are down-regulated by T3. In these cells, retinoic acid (AR) inhibits the adipose differentiation and the expression of early and late markers, and T3 sensitizes the cells to the inhibitory action of AR. We also show that AR down-regulates the expression of RT3 at both pre- and post-translational levels. This inhibition is dependent on AR concentration, a peculiar sensitivity to AR being observed at an early step of development.

Adipose Tissue↗