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Biomedical subjects

V Fournier

Publications and source records attributed to V Fournier.

At least 19 recordsLinked to original sources
PubMed2003

[Clinical forms of the cutaneous tuberculosis].

Since Laennec's description of the "prosector's wart" in 1826, science has made great strides forward. The cutaneous forms of the infection with Mycobacterium tuberculosis are various. The most common clinical forms of cutaneous tuberculosis are lupus vulgaris and scrofuloderma. The clinical forms of cutaneous tuberculosis are usually classified according to the patient's immune status, and the way through which the skin has been infected. Nonetheless, as in leprosy, a classification based on the importance of the bacterial inoculum in situ is possible. Subsequently the diagnosis should be considered as easy in the multibacillary forms and much more difficult in the paucibacillary forms. In the former, the diagnosis should rely on bacteriological data. In the latter, the diagnosis will rely on the association of epidemiological, clinical and histological data whereas genomic amplification with PCR may be of potential interest.

Humans↗
PubMed2002

Dietary arginine degradation is a major pathway in ureagenesis in juvenile turbot (Psetta maxima).

Recent studies indicate that urea excretion is responsive to protein intake and that turbot, Psetta maxima, appear to differ from other species by their urea excretion pattern and levels. This study was undertaken to evaluate the influence of dietary nitrogen and arginine on ureagenesis and excretion in turbot. Juvenile turbot (29 g) were fed semi-purified diets containing graded levels of nitrogen (0-8% dry matter) and arginine (0-3% dry matter) for 6 weeks. Growth data showed that turbot have high dietary nitrogen (123 mg/kg metabolic body weight/day) and very low dietary arginine (9.3 mg/kg metabolic body weight/day) requirements for maintenance. Requirements for unit body protein accretion were 0.31 g and 0.15 g for nitrogen and arginine respectively. Post-prandial plasma urea levels and urea excretion rates showed that urea production was significantly (P<0.05) influenced by dietary arginine levels. While hepatic arginase (EC 3.5.3.1) activity increased significantly (P<0.05) with increasing dietary arginine levels, activities of other enzymes of the ornithine urea cycle were very low. Our data strongly suggest that the ornithine urea cycle is not active in the turbot liver and that dietary arginine degradation is a major pathway of ureagenesis in turbot.

Ammonia↗
PubMed2002

Protein and arginine requirements for maintenance and nitrogen gain in four teleosts.

Besides being an indispensable amino acid for protein synthesis, arginine (Arg) is also involved in a number of other physiological functions. Available data on the quantitative requirement for Arg in different teleosts appear to show much variability. So far, there are very limited data on the maintenance requirements of indispensable amino acids (IAA) in fish. In the present study, we compared N and Arg requirements for maintenance and growth of four finfish species: rainbow trout (Oncorhynchus mykiss), turbot (Psetta maxima), gilthead seabream (Sparus aurata) and European seabass (Dicentrarchus labrax). Groups of fish having an initial body weight close to 5-7 g were fed semi-purified diets containing graded levels of N (0 to 8 % DM) and Arg (0 to 3 % DM) over 4 to 6 weeks. For each species, N and Arg requirements for maintenance and for growth were calculated regressing daily N gain against daily N or Arg intakes. N requirement for maintenance was estimated to be 37.8, 127.3, 84.7 and 45.1 mg/kg metabolic body weight per d and 2.3, 2.2, 2.6 and 2.5 g for 1 g N accretion, in rainbow trout, turbot, gilthead seabream and European seabass respectively. The four species studied appear to have very low or no dietary Arg requirements for maintenance. Arg requirement for g N accretion was calculated to be 0.86 g in rainbow trout and between 1.04-1.11 g in the three marine species. Turbot required more N for maintenance than the other three species, possibly explaining its reputedly high overall dietary protein requirement. Data suggest a small but sufficient endogenous Arg synthesis to maintain whole body N balance and differences between freshwater and marine species as regards Arg requirement. It is worth verifying this tendency with other IAA.

Amino Acids↗
PubMed2001

The effect of heparin on motility parameters and protein phosphorylation during bovine sperm capacitation.

It is generally accepted that incubation with heparin is required to induce capacitation of ejaculated bovine spermatozoa in vitro. The capacitation process implicates many biochemical events, and is correlated with modified sperm motility and the phosphorylation of specific proteins on tyrosine residues. To better understand the molecular basis of heparin-induced capacitation, bovine spermatozoa were incorporated with a radioactive substrate of protein kinases [gamma32P]-ATP, to observe protein phosphorylation dynamics over time. Sperm motion parameters including the percentage of motile spermatozoa, amplitude of lateral head displacement (ALH) and flagellar beat cross frequency (BCF) were assessed to determine whether the protein phosphorylation patterns induced by heparin also promote changes in motility. Capacitation was confirmed using the chlortetracycline fluorescence assay and the appearance of 'pattern B' stained spermatozoa. Evaluation of the different motility parameters during capacitation reveal that heparin has a marked negative effect, over time, on the percentage of motile spermatozoa, consistent with hyperactivation. Indeed, the presence of heparin greatly increases the BCF of bull spermatozoa and induces a significant increase in the ALH compared to spermatozoa incubated without heparin. We detected several sperm proteins that are phosphorylated over time. A 45 kDa protein is the most intensely phosphorylated of the sperm proteins. However, it is visible regardless of the presence of heparin. Interestingly, a second phosphorylated protein of approximately 50 kDa undergoes more intense phosphorylation with heparin than without. In summary, the present study demonstrated that heparin induces physiological changes in several sperm motility parameters including ALH, BCF and the percentage of motile spermatozoa. Heparin also increases the intensity of phosphorylation of a 50 kDa sperm protein. These results suggest that capacitation of bovine spermatozoa and capacitation-associated motility changes may be regulated by a mechanism that includes protein phosphorylation, and that a presently unknown protein kinase is involved.

Adenosine Triphosphate↗
PubMed2000

Hepatic ascorbic acid saturation is the most stringent response criterion for determining the vitamin C requirement of juvenile European sea bass (Dicentrarchus labrax).

Our main objective was to verify whether the dietary ascorbic acid (AA) requirement of juvenile European sea bass (Dicentrarchus labrax) varies as a function of different physiological needs. Practical diets with eight (0, 5, 10, 20, 40, 80, 160, 320 mg AA/kg diet) levels of ascorbic acid polyphosphate were fed to sea bass (mean weight: 0.7 g) for 15 wk. At the beginning and at the end of the feeding trial, tissues were sampled for vitamin C and hydroxyproline (HyPro) analysis. Dose-dependent responses of skin and whole body HyPro concentrations and hepatic AA concentration to dietary vitamin C levels were observed. Skin and whole body HyPro concentrations were low in sea bass fed AA-deficient diet, 217 and 15 nmol/g tissue, respectively. HyPro levels increased with increasing dietary levels, reaching plateaus of 297 and 45 nmol/g tissue in the skin and whole body at dietary vitamin C levels of at least 5 and 31 mg AA/kg. Hepatic AA level increased with increasing dietary levels, reaching a plateau of 474 pmol/g tissue in juveniles fed at least 121 mg of AA/kg. We concluded that hepatic AA saturation is the most stringent response criterion for determination of the vitamin C requirement in juvenile European sea bass.

Analysis of Variance↗
PubMed2000

Effects of liver transplantation on long-chain polyunsaturated fatty acid status in infants with biliary atresia.

BACKGROUND: The long-chain polyunsaturated fatty acid (LC-PUFA) status of infants with untreated biliary atresia (BA) is known to be poor and is correlated to the severity of the liver disease. Liver transplantation (LT) markedly increases survival of patients with BA but the extent to which this reverses poor LC-PUFA status is not known. METHODS: To explore this question, the erythrocyte (red blood cell, RBC) phospholipid content of eight infants with BA who underwent LT was determined 2 months after an initial portoenterostomy, immediately before LT, and 6 and 12 months after LT. Before LT, all infants were fed a protein hydrolysate formula containing medium-chain triglycerides and essential fatty acids. Afterward, they were fed a normal diet for age. The RBC phospholipid content at each time point was compared with that of 28 age-matched control infants. RESULTS: Just before LT, median RBC phospholipid content of C20:4n-6, C20:5n-3, and C22:6n-3 was 25%, 48%, and 30% lower, respectively, than that observed in age-matched control infants. After LT, the RBC phospholipid content of most fatty acids reached normal values by 6 months. However, that of C20:4n-6 and C22:6n-3 contents remained 5% and 15% lower, respectively, than in normal control infants. Twelve months after LT, C20:4n-6 content remained lower than in normal children, but that of C22:6n-3 did not differ. The ratio of C20:3n-6/C20:4n-6, a reflection of delta-5 desaturase activity, was abnormal compared with normal children before LT (0.17 vs. 0.10, P < 0.009) but normalized by 6 months after LT (0.11 vs. 0.10, not significant). CONCLUSIONS: These data show that the abnormal LC-PUFA status of children with BA improves after LT but is not entirely reversed within a year after surgery. They suggest that the abnormal status before LT may be secondary, in part, to low delta-5 desaturase activity. The extent to which a different pre- and/or post-LT diet can prevent PUFA deficiency and/or hasten recovery of PUFA status remains to be determined.

Biliary Atresia↗
PubMed1999

Prevalence and clinical significance of antiphospholipid antibodies in renal transplant recipients.

BACKGROUND: The prevalence and clinical significance of antiphospholipid antibodies (APAs) have not been extensively studied in non-systemic lupus erythematosus (non-SLE) renal transplant recipients. METHODS: To further define the prevalence and clinical significance of APAs in non-SLE renal transplant recipients and the appearance of dialysis-related APAs after renal transplantation, we conducted a retrospective study on 178 renal transplant recipients. Documentation of anticardiolipin antibodies (ACAs) and lupus anticoagulant in non-SLE renal transplant recipients, retrospective documentation of ACAs on pretransplant frozen plasma and standardized collection of demographic characteristics and posttransplant history of thrombosis were assessed. RESULTS: Fifty of 178 patients (28.1%) had APAs. Transplant duration was shorter and hemodialysis duration was longer in patients with APAs. A posttransplant history of both venous and arterial thrombosis was more frequent in patients with posttransplant APAs (respectively, 18% vs. 6.2% [P<0.001] and 8% vs. 2.3% [P<0.001]). Pretransplant sera were available from 55 patients. Most of patients with posttransplant ACAs had ACAs in the pretransplant period (85%). Pretransplant ACAs were associated with a posttransplant history of venous thrombosis (P<0.001). CONCLUSIONS: Our study demonstrates a high prevalence of APAs in non-SLE renal transplant recipients. Most of them have been acquired in the pretransplant period. Both pretransplant ACAs and posttransplant APAs are associated with posttransplant episodes of thrombosis. Further studies are required to determine the interest of prophylactic measures.

Adult↗
PubMed1998

Mycophenolate mofetil in renal transplant recipients with cyclosporine-associated nephrotoxicity: a preliminary report.

BACKGROUND: There is a great concern over cyclosporine (CsA) nephrotoxicity in renal transplant recipients, and the effects of conversion from CsA to azathioprine (AZA) remain controversial. Large studies have demonstrated that mycophenolate mofetil (MMF), the morpholinoethyl ester of mycophenolic acid, is superior to AZA as a posttransplant immunosuppressant. METHODS: Six patients with isolated biopsy-proven CsA nephrotoxicity were converted from CsA-AZA to MMF. RESULTS: Mean follow-up was 12+/-2 months. No patient experienced acute rejection. The mean serum creatinine concentration decreased from 225+/-58 to 159+/-66 micromol/L (P<0.0005). Hyperlipidemia and blood pressure improved after CsA withdrawal. CONCLUSION: In a selected transplant population with biopsy-proven CsA nephrotoxicity, CsA withdrawal with a concomitant switch from AZA to MMF seems to be safe and allows a significant improvement of renal function.

Aged↗
PubMed1998

Recurrence of hemolytic-uremic syndrome in renal transplant recipients: a meta-analysis.

BACKGROUND: Recurrence of hemolytic-uremic syndrome (HUS) in the allograft is associated with a very poor renal prognosis. Meta-analysis of previous trials may allow us to better estimate its real frequency, to identify risk factors for recurrence, and to predict the outcome of patients with definite recurrence. METHODS: An exhaustive search was conducted of HUS recurrence in renal transplantation from January 1977 to June 1997 using MEDLINE. RESULTS: Ten studies comprising 159 grafts in 127 patients were identified. The rate of recurrence was 27.8%. One-year graft survival was 76.6% in patients without recurrence and 33.3% in patients with recurrence (P<0.001). Older age at onset of HUS (16.96+/-7.6 years vs. 9.95+/-6.55 years; P<0.02), shorter mean interval between HUS and transplantation (2.51+/-2.7 years vs. 6.03+/-6.4 years; P<0.01), shorter mean interval between HUS and end-stage renal disease (0.79+/-0.39 years vs. 2.78+/-2.47 years; P<0.01), living-related donors, and the use of calcineurin inhibitors were associated with recurrence. CONCLUSION: Risk factors for HUS recurrence in renal transplantation could be identified through this meta-analysis.

Age Distribution↗
PubMed1998

CD4 lymphocytopenia as a risk factor for skin cancers in renal transplant recipients.

BACKGROUND: Renal transplant recipients are at increased risk of developing skin cancer. It remains difficult to establish the actual influence of overimmunosuppression in the development of skin cancers. We investigated whether lymphocyte subset count may predict the risk of developing skin cancer in long-term renal transplant recipients. METHODS: One hundred fifty long-term renal transplant recipients were followed for a mean period of 26 months. Each patient was examined at least annually by a dermatologist. Lymphocyte subsets were measured annually. RESULTS: Fifteen patients exhibited skin cancers. Patients with and without skin cancer did not differ in age, gender, transplant duration, hemodialysis duration before transplantation, immunosuppressive regimen, and serum creatinine concentration. CD4 cell counts were significantly lower in patients with skin cancers (330+/-179/mm3 vs. 503+/-338/mm3; P<0.01), whereas total lymphocyte and CD8 and CD19 cell counts were similar between the two groups. CONCLUSIONS: CD4 cell depletion is associated with skin cancer in long-term renal transplant recipients.

Adult↗
PubMed1998

Long-term follow-up of renal transplant recipients treated with losartan for post-transplant erythrosis.

Post-transplant erythrosis (PTE) develops in 9%-22% of all renal transplant recipients. Defined as a persistently elevated hematocrit (> 0.51), it occurs most commonly during the first 2 years post-transplantation in hypertensive males with excellent allograft function. Several studies have focused on a major role for angiotensin II in PTE pathogenesis, and some case reports have suggested that losartan is an effective treatment for PTE. Nevertheless, its long-term safety and efficiency have not been reported in renal transplant recipients suffering from PTE. We describe four patients successfully treated with losartan for PTE. Hematocrit remained normal for 21, 18, 15, and 15 months, respectively, after the beginning of losartan therapy. Mean erythropoietin concentration was not modified by treatment (17 +/- 3.7 mU/ml vs 17 +/- 3.8 mU/ml) and serum creatinine concentration remained stable. We conclude that losartan is a safe and effective long-term treatment for PTE.

Adult↗
PubMed1998

Fibrinogen A alpha chain mutation (Arg554 Leu) associated with hereditary renal amyloidosis in a French family.

A French family with hereditary renal amyloidosis (HRA) was studied. The disease presented in 7 of the 8 affected individuals with proteinuria or the nephrotic syndrome. The age of onset was in the fifth decade of life. There is currently no sign of extrarenal involvement in any affected individual. However, the nephropathy in this family is progressive and led to terminal renal failure in 4 patients. Immunohistochemistry studies of glomerular amyloid deposits suggested that the amyloid protein was the fibrinogen A alpha chain. Direct DNA sequencing revealed a G 4993 T transversion and subsequently Arg 554 Leu mutation in the fibrinogen A alpha chain. This is the first description of this fibrinogen A alpha chain mutation in Europe. This family is of French descent and cannot be related to the previously reported Peruvian/Mexican and African-American kindreds.

Adult↗
PubMed1998

Hyperhomocyst(e)inemia in renal transplant recipients with and without cyclosporine.

Studies have demonstrated that hyperhomocyst(e)inemia is present in renal transplant recipients and is correlated with cardiovascular disease. It is still unclear whether hyperhomocyst(e)inemia observed in renal transplant recipients solely depends on the moderate reduction of renal function in these patients or if additional mechanisms are operative in this patient category. A recent study suggested that cyclosporine (CsA) increased plasma homocyst(e)ine concentration in interfering with folate-assisted remethylation of homocysteine. To confirm this hypothesis, we studied plasma homocyst(e)ine folic acid and cobalamin concentrations in 122 renal transplant recipients (104 on CsA and 18 not receiving CsA). After adjusting for age, gender, transplant duration and serum creatinine concentration, patients with and without CsA had similar plasma homocyst(e)ine concentrations (17.9 +/- 6.1 mumol/l in CsA(+)patients vs 17.1 +/- 5.6 mumol/l in CsA(-)patients; p = 0.3). Moreover, we found a significant inverse relationship between plasma homocyst(e)ine and folic acid concentrations in both CsA(+) (r = 0.218; p < 0.01) and CsA(-) (r = -0.678; p < 0.05) patients. Patients with a past history of cardiovascular incidents had higher plasma homocyst(e)ine concentrations than those without cardiovascular antecedent (20.5 +/- 7.8 mumol/l vs. 18.01 +/- 9.9 mumol/l; p < 0.05. To conclude: 1, We did not find any influence of CsA on plasma homocyst(e)ine concentrations. 2. We demonstrated that as in other patient category, plasma folic acid and homocyst(e)ine concentrations are significantly correlated in CsA(+) patients. 3. Homocyst(e)ine-lowering therapy would be prescribed in CsA(+) patients to allow correction of hyperhomocyst(e)inemia.

Arteriosclerosis↗