Search PubMed⌕ Search

Biomedical subjects

C Dubois

Publications and source records attributed to C Dubois.

At least 55 records · Page 3Linked to original sources
PubMed1998

Postprandial studies on dietary cholesterol in human subjects using stable isotopes and gas chromatography-mass spectrometry analysis.

We hypothesized that intestinal absorption and postprandial re-secretion of dietary cholesterol may be a particularly complex process in humans. To test this hypothesis, we used deuterium-enriched cholesterol to specifically label meal cholesterol and developed an improved method for quantitative measurement of traces of deuterated cholesterol as well as cholesterol with reference to two different internal standards by gas chromatography-mass spectrometry (GC-MS) measurement. In the first study, a group of healthy subjects ingested a single test meal containing deuterated cholesterol with a 7 h postprandial follow-up. In the second one, a group of healthy subjects ingested a first test meal containing deuterated cholesterol and a follow-up was performed during three consecutive test meals and later until 72 h. The most striking observations were that the occurrence of dietary cholesterol in chylomicrons is not concomitant to triglycerides and is very low after a single meal while most dietary cholesterol is re-secreted in chylomicrons after a second, and even a third, fat test meal. The data obtained show that the re-secretion of dietary cholesterol from the small intestine is a slow and complex process in humans.

Adult↗
PubMed1998

Effects of graded amounts (0-50 g) of dietary fat on postprandial lipemia and lipoproteins in normolipidemic adults.

Eight normolipidemic males ingested on separate days and in a random order five mixed meals containing 0, 15, 30, 40, or 50 g fat. Fasting and postprandial blood samples were obtained for 7 h and chylomicrons and lipoproteins were isolated. The nonfat and 15-g fat meals did not generate noticeable postprandial variations except for HDL phospholipids (P < 0.05). The serum and chylomicron triacylglycerol responses obtained after the meals correlated positively with the amount of fat ingested and peaked after 2-3 h. Serum free cholesterol and phospholipids increased and esterified cholesterol decreased postprandially in a dose-response manner. At the same time, triacylglycerol-rich-lipoprotein triacylglycerols, esterified cholesterol, LDL free cholesterol, HDL triacylglycerols, phospholipids, and free cholesterol increased whereas LDL and HDL esterified cholesterol decreased when the amount of ingested fat increased. The data showed that increasing the amount of fat in the usual range of ingestion (0-50 g) led to stepwise increases in the postprandial rise of chylomicron and serum triacylglycerols and induced marked changes in serum lipoproteins postprandially. The existence of a no-effect level of dietary fat (15 g) on postprandial lipemia and lipoproteins in healthy adults was shown.

Adult↗
PubMed1998

Up-regulation of insulin-like growth factor binding protein-5 is independent of muscle cell differentiation, sensitive to rapamycin, but insensitive to wortmannin and LY294002.

Skeletal myoblast differentiation is stimulated by insulin-like growth factors (IGFs). The autocrine action of IGFs is mediated through the type-1 IGF receptor (IGFR-1) and modulated by IGF binding proteins (IGFBPs) secreted by the cells. The mouse C2 myoblast cell line stably transfected with a vector producing IGF-II antisense RNA was used to show that specific IGFBP expression changes with the state of the cells: high levels of IGFBP-2 messenger RNA (mRNA) were found only in proliferating myoblasts, whereas IGFBP-3 mRNA was induced in quiescent cells. Secretion of IGFBP5 was strongly stimulated during differentiation. Insulin and IGF dose-response experiments showed that up-regulation of IGFBP-5 resulted from IGFR-1 activation. Drugs interfering with IGFR-1 signaling and inhibiting myoblast differentiation had different effects on IGFBP-5 up-regulation. Two phosphatidylinositol 3-kinase (PI 3-kinase) inhibitors, wortmaninn and LY294002 [2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one], failed to alter IGFBP-5 up-regulation, which persisted in the absence of differentiation. Rapamycin which indirectly prevents activation of the p70 ribosomal protein-S6 kinase (p70S6k), suppressed IGFBP-5 induction. Because the PI3-kinase inhibitors block p70S6k, neither kinase would be required for IGFR-1-dependent IGFBP-5 induction. In C2 anti-IGF-II myoblasts, IGFBP-5 induction is therefore rapamycin-sensitive and independent of differentiation.

Androstadienes↗
PubMed1998

[Breech presentation: management (304 cases)].

UNLABELLED: BUT: Try to precise the optimal management in 1997 face a breech presentation. METHOD: Between January 1991 and December 1995, 304 cases of breech presentations were listed at the maternity of Pavillon Victor Olivier (Lille). From these 304 breech presentations, all parities blended, the authors have analysed the mode of delivery of these patients, distinguishing the para one from the multiparous women and the preterm babies from the other babies. From this study and a review of the literature, were discussed the criterions which can help the practitioner to determine the mode of delivery of these fetus. RESULTS: The results show a cesarean section (cs) rate of 51% (41% of first intention cs and 10% of second intention cs were realized only for primiparity + breech presentation and 67% of the para one women benefited from a first intention cs 8.72% of vaginal deliveries were complicated, and 5 fetal injuries were noted without sequel. On 296 live new-borns, only 2 cases of fetal death were perhaps due to the vaginal delivery. Fetal mortality is principally reliable at the prematurity and the congenital malformations, but finally, not due to mode of delivery. CONCLUSION: The difficulty is to determine rigorous criterions of selection to authorize a vaginal delivery without spoil the fetal pronostic. The major criterions are a perfect radiopelvimetry, an estimated fetal weight < 3800 g for the para one women and < 4300 g for the multiparous woman, a well flexed fetal head, favorable obstetric conditions ond the absence of maternal or fetal complications. The primiparity is not an indication of systematic cesariean section.

Breech Presentation↗
PubMed1998

[A prospective comparative study of coronary angiography and endocoronary ultrasonography in the detection of coronary lesions after cardiac transplantation].

Coronary angiography is the reference method for the detection of coronary disease of the cardiac grafts which threatens the long-term prognosis of cardiac transplantation. The primary results of treatment for slowing, stabilising or even improving coronary transplant disease are encouraging and make necessary the development and evaluation of reliable diagnostic methods. The authors undertook a prospective study of 48 asymptomatic patients with normal graft wall motion between January 1995 and March 1997 to compare the results of coronary angiography and endocoronary ultrasonography. The patients had been transplanted in the 10 years preceding the study. The results of the two methods were concordant in 33 cases (69%) (NS), for the confirmation (9 cases) or the information of coronary transplant disease (24 cases). The results were contradictory in 15 cases (31%): in 12 cases, endocoronary ultrasonography showed signs of coronary disease whereas the coronary angiography was estimated to be normal: in the remaining 3 cases, coronary angiography was abnormal but no signs of coronary disease were found on endocoronary ultrasonography. The specificity of coronary angiographic detection was 89% and therefore very satisfactory, but its sensitivity (43%) was poor. In addition, endocoronary ultrasonography allows analysis of the extension of coronary lesions to unstenosed segments, the quantification of intimal thickening. Therefore, endocoronary ultrasonography should become the reference investigation for coronary disease of cardiac transplants.

Adult↗
PubMed1998

[Polysialylated NCAM in CSF, a marker for invasive medulloblastoma].

We described a double-site enzyme-linked immunosorbent assay (ELISA) to measure polysialic acid neural cell adhesion molecule (PSA-NCAM) level in CSF. Immunocapture of PSA-bearing molecules is first effected by means of a monoclonal antibody (anti-MenB), directed against sialic acid polymers and adsorbed into plastic wells. Linked PSA-NCAM is then revealed by means of a second antibody, directed against an aminoacid sequence of NCAM and labelled with peroxydase. The lowest amount of PSA-NCAM detectable was estimated to be 0.11 microgram/l. This value was considered as the threshold for positivity. PSA-NCAM level was measured using this method in CSF from 29 patients with medulloblastoma. CSF had been collected at different times following tumor excision and stored at--80 degrees C. At the same times, cytological examination in CSF (medulloblastoma metastatic cells) and craniospinal imaging (tomographic scan or MRI) had been performed. PSA-NCAM was never detected in control CSF. For patients in remission, beyond the post-operative period of 1 or 2 months, 18 on 21 exhibited a PSA-NCAM level below the threshold value. For refractory patients, so classified according to the positivity of cytology and/or imaging, whatever the time after the tumor excision, PSA-NCAM was always positive (23/23), while either cytology or imaging were positive less frequently (16/23 for both). For relapses, PSA-NCAM was more frequently positive (6/7) than cytology and imaging (1/7 and 5/7, respectively). We concluded that PSA-NCAM positivity in CSF may be a reliable marker to detect the invasive or metastatic feature of medulloblastoma.

Biomarkers, Tumor↗
PubMed1998

[Giant cell myocarditis. Report of a case].

The authors report a case of giant cell myocarditis leading to rapidly progressive cardiac failure despite immuno-suppressor treatment in a 20 year old woman. The cardiac failure was successfully managed by implantation of a left ventricular assist device and then cardiac transplantation. The problems encountered underline the importance of accurate diagnosis by endomyocardial biopsy before undertaking treatment and the difficulties in the choice of appropriate method of assistance in this indication. Giant cell myocarditis is a rare cause of cardiac failure and should be considered in the differential diagnosis in view of its clinical features and risk of progression. The literature and the therapeutic implications are discussed.

Adult↗
PubMed1997

[Renal fibromuscular dysplasia and cerebral aneurysm in a hypertensive patient with a familial history of cerebral vascular complications].

BACKGROUND: The possibility of an association between two vascular anomalies, renal artery dysplasia and cerebral artery aneurysm, merits recognition. CASE REPORT: We report the case of a 63 year old woman who was found to have fibromuscular dysplasia affecting the right renal artery while being investigated for systemic hypertension. Given a family history of cerebrovascular accident occurring before the age of 50, a cerebral angiogram was performed which demonstrated a saccular aneurysm of the middle cerebral artery measuring 6 mm in diameter. DISCUSSION: The association of these two anomalies could result from a familial arterial fibromuscular dysplasia. There are practical implications, notably the risk of aneurysm rupture and the role of hypertension.

Cerebrovascular Disorders↗
PubMed1997

Super-acute aseptic spondylitis as the first manifestation of round calcifying nucleopathy in a 77-year-old man. A case report.

STUDY DESIGN: This is a report of an unusual case of very late onset, symptomatic, round calcifying nucleopathy. OBJECTIVE: To describe this unusual case of calcifying nucleopathy in a 77-year-old man who had no previous back problems, but had a history of diffuse skeletal hyperostosis. SUMMARY OF BACKGROUND DATA: The resorption of calcifying nucleopathy associated with reactional spondylitis is a classic occurrence in children but is rare in adults. METHODS AND RESULTS: Spondylitis was diagnosed on the basis of pain, a transient Babinski's sign, and systemic inflammation. Radiographs, a bone scan, and magnetic resonance imaging revealed a large calcified nucleopathy of the T12-L1 disc associated with spondylitis of T12. The calcification disappeared within 3 weeks, and recovery was clinically and biologically complete after treatment consisting of only rest and analgesics. CONCLUSION: A diagnosis of resorption of a round calcifying nucleopathy is not to be excluded in the elderly patient. This event can mimic an infectious spondylitis clinically and biologically.

Aged↗
PubMed1997

Non-Hodgkin's lymphoma of the heart in patients infected with human immunodeficiency virus.

A case of HIV-associated cardiac non-Hodgkin's lymphoma (NHL) is described, and the epidemiologic and clinicopathologic features of 21 cases previously reported in the literature are analyzed. All patients were homosexual males, and the cardiac NHL was the first acquired immune deficiency syndrome-defining condition in the majority. Patients were referred with nonspecific clinical findings including dyspnea and tachycardia, but rapid progression of cardiac dysfunction was frequent after symptoms appeared. Echocardiography constitutes the most useful noninvasive procedure in the diagnosis of cardiac NHL. Most of the patients had disseminated diseased at initial presentation; pathologically, the lymphomas were of B lymphocyte origin and of high-grade subtypes. Prognosis of HIV-associated cardiac NHL is generally poor, although clinical remission has been observed with combination chemotherapy. Cardiac lymphomas in HIV-associated patients are typically high-grade and often disseminate early. Although the prognosis is poor, patients in whom dissemination has not occurred could have longer survival under systemic chemotherapy.

Adult↗
PubMed1997

Risk factors for cirrhosis in patients with chronic hepatitis C virus infection: results of a case-control study.

The role of the viral genotype, especially genotype 1b, in the severity of liver injury induced by chronic hepatitis C virus (HCV) infection is unclear, probably because of confounding factors such as the date and mode of contamination. Host genetic or environmental factors such as heterozygous MZ alpha1-antitrypsin deficiency or alcoholism, could also be potential risk factors for the development of cirrhosis. The aim of this study was to compare the prevalence of genotypes, alpha1-antitrypsin phenotype, past hepatitis B virus infection, and alcohol consumption in cirrhotic and noncirrhotic patients with chronic hepatitis C. We conducted a case-control study comparing 84 consecutive cirrhotic patients with chronic hepatitis C (cases) with 84 noncirrhotic patients with chronic hepatitis C (controls) selected from a cohort of 464 patients hospitalized during the same period. Controls were paired with cases according to age, sex, risk factors, and date of infection. HCV genotypes were determined using the InnoLiPA technique (Innogenetics, Zwijnaarde, Belgium) and classified according to the method of Simmonds. Patients were divided in three groups according to alcohol consumption: <30 g/d (light), 30 to 80 g/d (moderate), and >80 g/d (heavy). Cirrhotic and noncirrhotic patients were not significantly different in terms of genotype distribution (1a/1b/2a/3a/others/undetermined: 10/48/7/17/0/2 versus 11/43/10/10/5/5), alpha1-antitrypsin phenotype distribution (MM/MS/MZ: 84%/14%/2% vs. 87%/11%/2%, respectively), and prevalence of antibody to hepatitis B core antigen positivity (29% vs. 23%). Alcohol consumption was significantly different between cases and controls (L/M/H: 58%/27%/16% vs. 76%/15%/9%, respectively; P < .05). Two conclusions regarding patients with chronic hepatitis C virus infection can be drawn from this study: 1) viral genotype, especially 1b, past hepatitis B virus infection, and heterozygous MZ alpha1-antitrypsin deficiency are not risk factors for cirrhosis; and 2) alcohol consumption, even moderate, is a risk factor for cirrhosis.

Adult↗
PubMed1997

Wortmannin inhibits IGF-dependent differentiation in the mouse myogenic cell line C2.

Evidence has accumulated that suggests that insulin-like growth factors (IGFs) exert a positive influence on myoblast differentiation. We have undertaken to study the signalling events required for differentiation resulting from type-1 IGF receptor stimulation in C2 myoblasts, where autocrine production of IGF-II was abolished by means of antisense RNA. Exposure of the cells to IGFs leads to a rapid and sustained activation of phosphatidyl-inositol 3-kinase followed by the expression of Myod, myogenin and differentiation. The fungal metabolite, wortmannin, inhibits both PI 3-kinase and muscle differentiation with an IC 50 in the nanomolar range. IGFs are also known to cause a rapid activation of MAP kinase. However, the synthetic inhibitor of MEK, PD098059, which prevents MAP kinase activation, does not affect myoblast differentiation. These results provide evidence that PI 3-kinase, but not MAP kinase, is required for insulin-like growth factor receptor-dependent differentiation of muscle cells.

Androstadienes↗
PubMed1997

Digestive and metabolic effects of potato and maize fibres in human subjects.

The physiological effects of dietary fibres in humans are due to their physico-chemical properties. However, it is difficult to predict these effects simply by measuring certain characteristics in vitro. Studies in human subjects are still required to assess the effectiveness of new substrates. The aim of the present study in healthy human subjects was to evaluate the effects of two novel fibres, potato (PF) and maize (MF), on fasting and postprandial blood concentrations of carbohydrate and lipid metabolites as well as on stool output and transit time. The chemical composition, water-binding capacity (WBC) and fermentative properties of the fibres were also characterized in order to determine their possible involvement in digestive and metabolic effects. Stools, as well as breath and blood samples, were collected after consumption for 1 month of either a basal diet (control) or a basal diet supplemented with fibre (15 g/d). MF resisted fermentation better than PF and had lower digestibility. However, both fibres increased faecal output of dry matter, neutral sugars and water. There was an inverse relationship between stool weight and orofaecal transit time, although only MF significantly reduced transit time. Orocaecal transit was lengthened by PF, probably because of its high WBC. PF ingestion also decreased postprandial plasma levels of total and esterified cholesterol but had no effect on fasting concentrations. In contrast, MF lowered fasting cholesterolaemia and increased free:esterified cholesterol. These particular physiological and fermentative properties suggest that PF and MF would be suitable ingredients in a healthy diet.

Adult↗
PubMed1997

Dietary triglycerides, up to 40 g/meal, do not affect preformed vitamin A bioavailability in humans.

OBJECTIVE: Assessing the effect of the dose of dietary triglycerides on preformed vitamin A (retinyl esters) bioavailability in humans. DESIGN: Four test meals containing 15,000 RE retinyl-palmitate and either 0, 15, 30 or 40 g added triglycerides were ingested by eight healthy volunteers, at different days and in a randomized order. SETTING: The study was done in the Hospital Sainte Marguerite, Marseille, France. SUBJECTS: Eight healthy male volunteers were recruited by advertisement. INTERVENTION: Blood samples were collected every hour for seven hours after the test meals intake. Serum and chylomicron (Svedberg flotation unit > 1000) were prepared by centrifugation and retinyl esters were measured by HPLC. RESULTS: The serum retinyl ester response was not significantly lower after the intake of the meal without added triglycerides (7944 +/- 3262 nmol/L h) than after the intake of the fat meals (10012 +/- 2182, 7869 +/- 3157 and 10777 +/- 2067 nmol/L h for the 15, 30 and 40 g-fat meal, respectively), indicating that the serum retinyl ester response was not related to the amount of meal triglycerides. Chylomicron retinyl linoleate response stepwise increased when the amount of meal triglycerides increased while retinyl palmitate and retinyl stearate responses reached a maximum since 15 g triglycerides. Postprandial serum retinol concentration did not change whatever the meal ingested. CONCLUSIONS: (i) a significant amount of preformed vitamin A is apparently absorbed when ingested with trace amount of meal triglycerides only; (ii) meal triglycerides, up to 40 g/meal, do not increase preformed vitamin A bioavailability; (iii) the retinyl ester pattern recovered in the chylomicrons, and probably the esterification process of retinol, is affected by the amount of meal triglycerides; (iv) postprandial retinol homeostasis is not affected by dietary triglycerides.

Adult↗
PubMed1997

Postprandial lipaemia is exacerbated in fat-cholesterol-fed rabbits: relationship to atheroma deposition.

The aim of the present study was to evaluate the links between chronic fat-cholesterol intake, postprandial lipaemia and atherogenesis in New Zealand White rabbits. Adult rabbits were fed on either a low-fat control diet (LF) or a high-fat, high-cholesterol diet (HF). Rabbits received a test meal containing [3H]cholesterol and [14C]triolein on days 0 and 63 for the LF group and days 14, 28, 42, 63 and 84 for the HF group. Blood was collected 24 h post-absorptively and 10, 24, 34 and 48 h after test-meal intake. Post-absorptive as well as postprandial lipoproteins and lipaemia were not modified in the LF rabbits, who did not show any atheroma deposition on day 119. In HF rabbits, postprandial plasma triacylglycerols peaked 24-34 h after meal intake. The 0-48 h areas under the curves of triacylglycerol and triacylglycerol-rich lipoproteins (TRL) steadily increased with time of chronic lipid feeding with values significantly higher than those in the LF rabbits. The postprandial plasma and TRL concentrations of dietary radiolabelled lipids were significantly higher in HF than LF rabbits. Post-heparin lipoprotein lipase (EC 3.1.1.34) and hepatic lipase (EC 3.1.1.3) activities were twofold higher in HF rabbits than in LF rabbits at day 105. In HF rabbits, a marked atheroma plaque deposition in the aorta was observed (30.9 (SE 3.9) % of total surface). The extent of atheroma deposition was positively correlated to the postprandial responses of plasma total triacylglycerols and dietary-derived lipids as well as total cholesterol and dietary-derived cholesterol in HF rabbits. In conclusion, chronic ingestion of a HF diet led to marked increases in postprandial lipaemia and TRL particles, and atheroma deposition.

Animals↗
PubMed1997

Effects of lowering fat and increasing dietary fiber on fasting and postprandial plasma lipids in hypercholesterolemic subjects consuming a mixed Mediterranean-Western diet.

The aim of this study was to evaluate the cholesterol-lowering effects of reducing fat and increasing or not increasing dietary fiber in subjects consuming a mixed Mediterranean-Western diet. Thirty-one free-living, mildly hypercholesterolemic subjects were randomly allocated to two groups. Subjects in both groups first shifted for 4 wk to a low-fat, low-fiber diet (LFLFD). For an additional 4-wk period, subjects in group 1 continued consuming the LFLFD whereas subjects in group 2 consumed a low-fat, high-fiber diet (LFHFD). Most dietary fatty acids were monounsaturated (38-41%) and fibers, when provided (up to 35 g/d), came from unrefined cereals, legumes, and soluble-fiber-enriched ready-to-eat cereals. After period 1 of the LFLFD, mean serum and low-density-lipoprotein (LDL)-cholesterol concentrations of subjects in groups 1 (-12.5% and -15.5%, respectively) and 2 (-10.5% and -15.5%, respectively) decreased significantly from baseline (P < 0.05). After period 2, mean serum and LDL-cholesterol concentrations of subjects consuming the LFLFD (group 1) were still lower (by 8.8% and 9.2%, respectively, from baseline) whereas in subjects consuming the LFHFD (group 2) these values decreased further to significantly lower values (14.2% and 17.6% from baseline, respectively). Fasting high-density-lipoprotein (HDL) cholesterol, apolipoprotein A-I, glycemia, and insulinemia did not change significantly. In seven men, postprandial lipemia transiently increased more after a breakfast test meal at the completion of the LFHFD period than after the LFLFD period. In conclusion, an LFHFD more comparable with the traditional Mediterranean diet may improve the dietary management of moderate hypercholesterolemia.

Adult↗
PubMed1997

In-vivo activity and tolerance of conventional formulation versus fat emulsion formulation of amphotericin B in experimental disseminated candidiasis in neutropenic rabbits.

Amphotericin B can cause significant toxicity but this can be reduced by direct dilution into a fat emulsion (Intralipid). To investigate the potential use of amphotericin B diluted in Intralipid, a study was made of its activity in the treatment of subacute disseminated candidiasis in persistently granulocytopenic rabbits, compared with the same dose of amphotericin B diluted in dextrose. Amphotericin-B-fat emulsion was at least as effective as amphotericin-B-dextrose. Amphotericin-B-fat emulsion was significantly more effective than amphotericin-B-dextrose therapy in reducing candida colony counts in both kidney and liver tissues (P < 0.05). Furthermore, amphotericin-B-fat emulsion was found less toxic on the renal function than conventional amphotericin B (P < 0.05). From these experimental results, we conclude that amphotericin-B-fat emulsion (Intralipid) was at least as effective and less toxic than conventional amphotericin B.

Amphotericin B↗