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Biomedical subjects

D Durand

Publications and source records attributed to D Durand.

At least 145 records · Page 8Linked to original sources

Plasma lipoproteins in preruminant calves fed diets containing tallow or soybean oil with and without cholesterol.

Five-week-old, preruminant male calves were fed milk replacer containing tallow or soybean oil (230 g/ kg of dietary DM) with and without cholesterol (10 g/ kg of dietary DM) for 17 d in order to study changes in plasma lipids and lipoproteins. Dietary soybean oil induced higher cholesterolemia than did tallow because of a specific increase in plasma concentrations of large high density lipoproteins of type 1 (1.026 to 1.060 g/ml), but plasma concentrations of low and very low density lipoproteins were not modified. Addition of cholesterol to diets containing either tallow or soybean oil markedly increased plasma concentrations of intermediate and low density lipoproteins, suggesting partial inhibition of the low density lipoprotein receptor activity in tissue. By contrast, dietary cholesterol added to the diet containing soybean oil led to an increase in plasma concentrations of type 1 high density lipoproteins and of light high density (1.060 to 1.091 g/ml) lipoproteins. These data indicated that the soybean oil diet, which was rich in linoleic acid, did not reduce the effects of dietary cholesterol on the metabolism of low and high density lipoproteins in the preruminant calf.

Aging↗

Effects of diets containing tallow and soybean oil with and without cholesterol on hepatic metabolism of lipids and lipoproteins in the preruminant calf.

The effects of long-chain fatty acids (230 g/kg of dietary DM) from tallow and from soybean oil, with or without cholesterol (10 g/kg of dietary DM), on hepatic lipid contents and on in vivo hepatic production rates of lipids and lipoproteins were investigated in 22 preruminant male calves fitted with chronic catheters and with electromagnetic blood flow probes implanted in the hepatic vessels. Diets containing soybean oil and soybean oil with cholesterol led to the development of triglyceride infiltration in the liver and to higher apparent hepatic secretion of very low density lipoproteins than did diets containing tallow or tallow with cholesterol. Addition of cholesterol to diets favored accumulation of low density lipoproteins in plasma and the net apparent secretion of these particles by the liver, especially for the diet containing soybean oil with cholesterol. Regardless of the diet, calf liver clearly removed large high density lipoproteins of type 1 that were rich in cholesteryl esters but secreted heavy high density lipoproteins that were rich in proteins. The intensity of removal of high density lipoproteins of type 1 by the liver depended on the plasma concentration of these particles, probably by mass action. This removal did not prevent the accumulation of high density lipoproteins of type 1 in plasma, such as it did in calves fed soybean oil.

Animals↗

[Acute renal insufficiency in renal transplants treated with interferon-alpha for chronic hepatitis C].

Sixteen renal transplant (RT) patients (10 men, 6 women, aged 49 +/- 10 years) with chronic hepatitis C received alpha interferon (IFN alpha) therapy (Intron A, Schering Plough) at a dose of 3 x 10(6) units s.c. 3 times a week, scheduled for 24 consecutive weeks. At the beginning of the study all had a stable renal function since at least 12 months (mean serum creatinine -SCr- 121 +/- 38 mmol/l). Fourteen patients were receiving cyclosporin A (CsA) either alone (1) or in combination with steroids and/or azathioprine -AZA- (double therapy: 8; triple therapy: 5); two patients were on conventional therapy. The mean daily doses of CsA were 2.6 mg/kd i.e. a mean whole blood trough level of 104 ng/ml. Six patients experienced renal failure either acute (5) or subacute (1) within 7 to 24 weeks after the start of IFN alpha therapy. Their mean SCr increased from 105 +/- 31 mmol/l to 207 +/- 63 mmol/l (p = 0.02) with de-novo proteinuria in one case (1 g/d) and an increase in pre-existing proteinuria in 2; 3 remained without proteinuria. The histological study showed in all cases a diffuse interstitial edema associated with dilatation of peritubular capillaries; mild inflammatory infiltrates were present in only 3 cases; mild glomerular lesions were not always found (glomerular ischemia, mesangial hypertrophy). There was no vascular lesions IFN alpha was withdrawn in these 6 patients, associated with methylprednisolone pulses in 5 cases. Renal function improved in two cases, stabilized in one and progressed to end stage renal failure in 3 within 4 to 12 months. Four patients had iterative renal biopsies showing in all cases diffuse interstitial fibrosis. This subgroup of patients did not statistically differ at the start of the study from those who did not develop renal failure according to baseline immunosuppression, HLA matching, total peripheral blood lymphocyte (PBL) count. PBL subtypes. INF alpha therapy was associated with acute or subacute renal failure in 37% of patients. The most prominent histological finding was a diffuse interstitial edema of rapid onset, without signs of cellular or vascular rejection. Thus we do not recommend to use IFN alpha therapy in RT patients with chronic hepatitis C, until the mechanisms of the subsequent renal failure be more understood.

Acute Kidney Injury↗

Treatment of chronic hepatitis C with recombinant interferon alpha in kidney transplant recipients.

Chronic hepatitis C is a common cause of viral liver disease in kidney transplant (KT) recipients. To assess the efficacy and safety of therapy with interferon alpha we conducted a prospective study where 14 cadaveric KT recipients with chronic hepatitis C received recombinant interferon alpha-2b (IFNa) 3 million units three times weekly (scheduled) for 6 months (group A). 14 KT recipients with chronic hepatitis C were not treated and served as controls for the study period (group B). All the patients in both groups had had stable renal function for at least one year. All patients in both groups had a positive HCV viremia at the beginning of the study. Patients of group A were treated for 142 +/- 34.8 days (range 65-168); elevated serum aminotransferase (ALT) levels decreased rapidly and significantly from 100.3 +/- 48.9 to 37.7 +/- 13.9 IU/L (P = 0.001); 10 patients (77%) were "responders," whereas the others experienced a decrease in ALT values but without reaching the normal ranges. With a mean follow-up of twelve months after discontinuation of IFNa therapy, 8 responders--i.e., 80%--relapsed within 1-20 weeks. Only 4 patients had no detectable HCV viremia at the end of the IFNa; two of them already have abnormal values of ALT. Moreover HCV viremia was present in all patients one month after the cessation of IFNa treatment. Side effects of IFNa (fatigue, anorexia, weight loss) were frequent, and 3 patients decided to drop out of the treatment. The hematological tolerance was good although there was a significant decrease in hemoglobin (11.9 +/- 1.7 vs. 13.4 +/- 1.7 g/dl; P = 0.0044). In group B, serum ALT levels did not significantly decrease (84.2 +/- 47.6 vs. 105.2 +/- 68.8 IU/L). At the end of the study period serum ALT levels were significantly lower in group A than in group B (37.7 +/- 13.9 vs. 84.2 +/- 47.6 IU/L, P = 0.013). The major concern in group A was the occurrence of 5 renal failures. Kidney transplant biopsies showed edema, no significant tubulitis, scarcely scattered interstitial inflammatory cellular infiltration, and mesangial thickening. Four patients received methylprednisolone pulses but renal function improved in only two cases. We were not able to discover predictive factors of renal failure. We conclude that IFNa therapy is effective in controlling disease activity--i.e., reducing amino-transferase levels in KT patients with chronic hepatitis C, although relapse and detection of HCV RNA after the cessation of treatment were observed, respectively, in 80% and 100% of patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

Effects of dietary fat and L-methionine on the hepatic metabolism of very low density lipoproteins in the preruminant calf, Bos spp.

The effects of triglycerides (TG) from tallow (1.21 and 2.13 g TG/kg of body weight (BW) per meal, diets R and B respectively) and from tallow plus cream (2.50 g TG/kg of BW per meal, diet L) with or without L-methionine (2.6 g/kg dry matter) on hepatic apparent secretion of very low density lipoproteins (VLDL) were investigated in 3 groups of 4 preruminant calves fitted with chronic catheters and with electromagnetic blood-flow probes implanted in their hepatic vessels. Increasing TG concentrations stimulated the apparent VLDL secretion by the liver (1.02, -0.36 and -1.51 mg VLDL mass/min per kg of BW in diets L, B and R, respectively). L-Methionine increased this secretion when associated with the lipid-restricted (diet R; 0.25 and -1.51 mg VLDL/min per kg of BW) and basal (diet B; 0.35 and -0.36 mg VLDL/min per kg of BW) diets (non-significant). However, the VLDL apparent secretion decreased with the lipid-enriched diet (diet L), which suggests an insufficient dose of L-methionine compared with the level of TG intake, and a possible competition between liver and intestine for utilization of L-methionine for the synthesis of TG-rich lipoproteins.

Animals↗

Adaptation of energy metabolism to undernutrition in ewes. Contribution of portal-drained viscera, liver and hindquarters.

Adaptation of energy metabolism to undernutrition and to the duration of undernutrition was studied in adult, non-pregnant, non-lactating ewes at the whole-animal, portal-drained viscera, liver and hindquarters levels. Arterio-venous and indirect calorimetry techniques were used. Animals were successively fed at 1 times (3 weeks) and at 0.5 times (7 weeks) their metabolizable energy requirements for maintenance (MEm). Portal, hepatic and hindquarters blood flows in quietly standing ewes decreased by 22, 19 and 11% respectively within the first week of undernutrition and remained at that level thereafter. Standardizing hindquarters blood flow to that in a given posture (quietly standing) reduced blood flow by 9.8%. In the portal-drained viscera and liver, O2 extraction rates decreased, leading to 34 and 38% drops in O2 consumption with underfeeding respectively. In the hindquarters, O2 extraction rate increased, partly counterbalancing the drop in blood flow. Thus O2 consumption of hindquarters tended to decrease but the effect was not significant. All changes appeared to be completed from day 5 of underfeeding. Consequently, the portal-drained viscera, liver and carcass were responsible for 39, 32 and 5% respectively of the drop in whole-animal O2 consumption with underfeeding. At the end of the 0.5 x MEm period, in vivo metabolic rates averaged 1.65, 4.89 and 0.38 mmol O2 consumed/d per g fresh weight of adipose-tissue-free portal-drained viscera, liver and boneless hindquarters respectively. Undernutrition imposed a much greater nutritional challenge to splanchnic tissues than to hindquarters. The former reduced their energy expenditure whereas hindquarters metabolism adapted by counteracting the slight drop in nutrient supply.

Adaptation, Physiological↗

Renal functional reserve in calcium channel blocker-treated hypertensive recipients of kidney transplant.

Renal functional reserve during infusion of an amino acid solution was examined in 12 cyclosporin-treated kidney recipients at 1 (T1) and 8 months (T2) after transplantation. Patients were retrospectively divided into six normotensive (NT) and six hypertensive recipients (HT) maintained on monotherapy with a calcium channel blocker. Baseline glomerular filtration rates (GFR) were similar in NT and HT at T1 and T2. Renal functional reserve was identical in NT and HT at T1 (15 +/- 7 vs 18 +/- 13 ml/min/1.73 m2) but significantly greater in HT at T2 (11 +/- 5 vs 23 +/- 10 ml/min/1.73 m2; P < 0.05). At T2, baseline proximal tubule outflow (lithium clearance) was greater in HT (26 +/- 8 vs 16 +/- 3 ml/min/1.73 m2; P < 0.05), whereas fractional proximal reabsorption was less (54 +/- 11% vs 67 +/- 5%; P < 0.05). These results indicate that: (i) hypertensive recipients on calcium channel blocker therapy do not exhibit permanent glomerular hyperfiltration until 8 months after transplantation, and have a reduced proximal reabsorption; (ii) measurement of amino acid-stimulated GFR and renal functional reserve is a more sensitive method than that of baseline GFR for evaluating renal function and the effects of therapy in kidney recipients.

Adult↗

Preliminary results of treatment of chronic hepatitis C with recombinant interferon alpha in renal transplant patients.

Chronic hepatitis C is a common cause of viral liver disease in kidney transplant recipients. To assess the efficacy and the safety of therapy with interferon alpha (IFN alpha) in such a population we conducted a prospective study where 16 kidney transplant recipients with chronic hepatitis C received recombinant IFN alpha 3 million units three times weekly scheduled for 24 consecutive weeks. All the patients had stable renal function for at least 1 year (mean serum creatinine 125.4 +/- 41 mumol/l). Fifteen patients had a positive HCV viraemia at the beginning of the study. In 15 patients serum alanine aminotransferase (ALT) levels decreased rapidly and normalized (48 +/- 44 vs 98.5 +/- 46 IU/l; P = 0.0044). ALT remained in the normal range as long as IFN alpha was continued. Serum levels of gamma glutamyl transpeptidase decreased from 129.75 +/- 111.2 to 88 +/- 85 IU/l; P = 0.012). After discontinuation of IFN alpha therapy seven responders relapsed within 1-9 weeks. HCV viraemia assessed 1 month after the end of IFN alpha therapy remained positive in all the patients who scored positive at the beginning, i.e. 15. Side effects of IFN alpha (fatigue, anorexia, weight loss) were frequent leading to four patients dropping out of the study. The haematological tolerance was moderate. The major concern was the increase in serum creatinine (162.5 +/- 57.6 vs 125.4 +/- 41 mumol/l; P < 0.05). In fact only six patients experienced renal failure occurring 45-168 days after the beginning of IFN alpha. Kidney transplant biopsies showed oedema, scarce scattered interstitial inflammatory cellular infiltration and moderate mesangial hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Calciphylaxis in a chronic hemodialysis patient with protein S deficiency.

Vascular calcifications are common in uremic patients whereas calciphylaxis is rare. We report the case of a 45-year-old woman on chronic hemodialysis since 1977. She had a subtotal parathyroidectomy in 1985, aortic and mitral valve replacement in 1986, and has been treated since then with nicoumalone. In June 1991, she presented with repeated, painful cutaneous necrosis suggesting panniculitis. A skin biopsy showed lobular panniculitis and evidence of calciphylaxis. There was an obvious biological hyperparathyroidism. Protein C functional level was in the normal range whereas protein S functional level was low, i.e. 42%. The patient underwent cervical surgery to remove two parathyroid glands, and daily hemodialysis sessions. Despite this treatment, cutaneous necrosis progressed with superinfection. A few weeks later, the patient died from a septic shock after a myocardic infarction. Necropsy was not performed.

Calciphylaxis↗

Circadian changes in energy expenditure in the preruminant calf: whole animal and tissue level.

A study was conducted using four preruminant calves to determine the contribution of portal-drained viscera, liver, and hindquarters to circadian changes in total energy expenditure, after removing variations due to behavioral patterns. Indirect calorimetry and in vivo arterio-venous techniques were used. Standing time was longer (P < .01) after the meals and shorter (P < .01) at night. These variations were associated with higher (P < .01) energy cost of standing immediately after the meals and lower (P < .01) ones at night. When these behavioral effects were removed, total energy expenditure of lying calves was shown to be stable between the morning and evening meal, to increase by 11.5% and remained elevated during the 6 h after the evening meal, and to reach the lowest values at night. Portal-drained viscera and liver contributed 32.8 to 53.7% and 29.1 to 32.2%, respectively, to the circadian variations calculated for calves that were always standing. Changes in splanchnic tissue energy expenditure resulted from combined modifications in blood flow and O2 extraction rate. The contribution of hindquarters could not be clearly established. Overall, portal-drained viscera, liver, and hindquarters contributed 17.2, 12.8, and 18.0%, respectively, to total energy expenditure of standing calves. Their respective in vivo metabolic activities averaged 1.08, 2.10, and .25 mumol of O2 consumed.min-1.g-1 of fresh tissue.

Animals↗

Correction of post-renal transplant erythrocytosis by enalapril.

We studied whether post-renal transplant erythrocytosis (PRTE) could be corrected by enalapril with minimal side-effects, thus avoiding iterative phlebotomies or bilateral nephrectomy of native kidneys. From our renal transplant patients, 12 presented a true PRTE as defined by a 51-Cr red blood cell mass (RBCM) above 32 ml/kg for women and above 36 ml/kg for men. Secondary polycythemia was ruled out: all the patients had a normal renal artery pulsed ultrasonography; in all cases the blood arterial 02 saturation was above 96%. Bone marrow aspiration and histology were performed for each patient: none of them showed evidence of Vaquez disease. All of them had stable renal function i.e. the mean serum creatinine was 112.8 +/- 26.3 mumol/l. They all received the same immunosuppression: azathioprine; ciclosporine A; methylprednisolone. PRTE occurred within the first year post transplant (median 7.5 months; range: 2-34). Their mean RBCM was 37.38 +/- 2.7 ml/kg. Their mean serum value of Epo was 17.41 +/- 13.5 mU/ml (range: 9.1-54). After informed consent, all patients received enalapril starting with 5 mg/day, progressively increased to 20 mg/day, if necessary, in order to maintain the hematocrit below 45%. The mean daily dosage of enalapril was 13.75 +/- 6.1 mg (range: 5-20). The mean follow-up was 14.8 months (range: 3.5-29.5). There was no change in renal function (mean serum creatinine: 126.3 +/- 35 mumol/l). A successful response to enalapril was obtained with a median of 40 days (range: 20-120). 11 patients out of 12 responded to enalapril with a decrease of Hb (14 +/- 2 g/dl vs 16.8 +/- 1.04 g/dl; p = 0.0006) and Ht (41.9 +/- 6.17% vs 51.14 +/- 2%; p = 0.0002) without a significant decrease of Epo (8.1 +/- 3.87; p = 0.1). One patient did not respond to enalapril nor to captopril, but did respond to a combined treatment of enalapril and theophilline. Moreover, all PRTE patients but two did not have Epo levels, before enalapril, above the normal range, suggesting mechanisms other than Epo overproduction by native kidneys i.e. erythropoiesis dysregulation. In conclusion, all patients but one were successfully treated by enalapril without side effects. The treatment was effective as early as 3 weeks from the start and avoided the need for iterative phlebotomies and nephrectomy of native kidneys.

Adult↗