Search PubMed⌕ Search

Biomedical subjects

G Jean

Publications and source records attributed to G Jean.

At least 73 records · Page 4Linked to original sources
PubMed1985

Altered oxidative metabolism, motility, and adherence in phagocytic cells from cystinotic children.

The present study investigates whether the metabolic abnormalities in cystinotic cells could affect nonspecific immune responses. Lymphocytes showed normal antibody-dependent cellular cytotoxicity and natural killer activity. However, cystinotic polymorphonuclear and mononuclear phagocytes exhibited altered oxidative responses as monitored by a luminol dependent chemiluminescence (CL) assay. Both isolated polymorphonuclear and mononuclear phagocytes in the absence of stimuli showed significantly increased CL production which was not found when cells were tested directly within whole blood. CL responses to a panel of stimuli differed markedly according to the type of cells and agents tested. Indeed, isolated polymorphonuclear demonstrated increased CL responses to soluble but not particulate agents, whereas isolated mononuclear phagocytes and overall cell CL responses in whole blood were found to be within the normal range regardless of the type of stimulus used. We also studied some membrane related properties of phagocytic cells. Fc and C3b receptors were normally expressed as tested by erythrocyte-antibody and erythrocyte-antibody-complement rosette-forming cells. Nevertheless, cystinotic polymorphonuclear and mononuclear phagocytes presented decreased random and directed migrations in an under-agarose chemotaxis assay. Finally, cystinotic granulocytes showed an impaired adhesiveness in a nylon fiber assay.

Cell Adhesion↗
PubMed1984

Cirrhosis associated with multiple transfusions in thalassaemia.

The study of surgical liver biopsy specimens obtained during splenectomy in 86 children with thalassaemia indicated that such patients may develop liver disease that evolves into cirrhosis. Histological characteristics suggest that it is post-necrotic cirrhosis. Onset of cirrhosis in some patients may occur as early as 7-8 years old, and at age about 15-16 years most children with thalassaemia show features of cirrhosis. In addition to fibrosis, hepatitis, or even aggressive hepatitis may develop as has also been observed in patients without thalassaemia who have undergone multiple transfusions. This study presents the current probable evolution of liver disease in patients with thalassaemia and may thus serve as a reference from which to evaluate any future progress in the treatment and care of patients with Cooley's disease.

Adolescent↗
PubMed1984

Hepatitis B or non-A, non-B virus infection in multitransfused thalassaemic patients.

We undertook a four year study of 128 thalassaemic patients who had undergone several transfusions, to determine the incidence of hepatitis B virus markers and the activities of transaminases in their sera each month. The results showed that the possibility of these patients contracting hepatitis B virus infection is still high, although on only one occasion was a transient antigenaemia found, indicating low viral replication. Furthermore, the probability of contact with hepatitis B virus increases with the number of transfusions and, therefore, with age. About 25% of these patients were positive for hepatitis B markers and 80% for other hepatitis markers including the case of cytomegalovirus hepatitis.

Adolescent↗
PubMed1984

Adriamycin and adriamycin-DNA nephrotoxicity in rats.

The early nephrotoxicity of free and DNA-bound adriamycin (ADR) was compared in left nephrectomized rats. Free ADR induced progressive renal failure within 3 weeks, in association with renal changes characterized by severe tubular distention and vacuolization of podocytes in glomeruli. On the contrary, renal function remained normal and renal lesions were discrete in animals treated with ADR bound to DNA. Thus, the binding of ADR to DNA seems to reduce the early nephrotoxicity of free ADR.

Acute Kidney Injury↗
PubMed1983

Chronic liver disease in children with leukemia in long-term remission.

Liver disease during chemotherapy and after its completion was studied in 103 leukemic children in long-term remission. Seventy developed chronic liver disease during therapy; 22 out of 56 with adequate follow-up showed persisting abnormality or deterioration of liver function after stopping therapy. In 38 studied prospectively, biopsies were obtained at treatment withdrawal. Five showed chronic lobular, 17 chronic persistent, 9 chronic active hepatitis whereas 7 had minimal changes. These children had transiently detectable serum hepatitis-B virus (HBV) markers during (44.4%), at completion of (7.8%) and subsequent to (48.3%) chemotherapy. Serum HBV markers correlated significantly with both severity of histologic changes (P less than 0.05) and persistent biochemical abnormalities for over 6 months after treatment suspension (P less than 0.001). No direct relationship was found between drug administration and liver damage. The data from the study suggest that in leukemic children viral infections contribute to chronic liver damage, which can jeopardize the long-term prognosis of acute leukemia.

Acute Disease↗
PubMed1983

Nutritional and metabolic studies in children on continuous ambulatory peritoneal dialysis.

A study was done of 15 children and adolescents, aged 2.5 to 17.5 years, who were treated by continuous ambulatory peritoneal dialysis (CAPD) for 6 to 24 months. Plasma albumin concentration decreased from 34.4 +/- 4.8 g/liter at the onset of therapy to 31.3 +/- 5.3 g/liter after 19 to 24 months. Children less than 6 years old had lower albumin levels (29.4 +/- 1.7 g/liter) than did the older group (36.3 +/- 4.2 g/liter). The lower plasma albumin was related to peritoneal protein loss but not to protein intake. Plasma free amino acid concentrations were not significantly modified. No changes occurred in the oral glucose tolerance test during the course of CAPD. Plasma cholesterol and triglycerides were abnormally high for age, with a correlation seen between cholesterolemia and peritoneal protein loss.

Adolescent↗
PubMed1983

Beneficial effects of methylprednisolone on urinary excretion of lysosomal enzymes in acute renal ischemia.

An experimental model of canine normothermic renal ischemia was used to determine whether lysosomal urinary enzyme excretion reflects the extent of ischemic cellular injury, as assessed by subsequent renal function (serum creatinine level) and morphologic changes. The value of a lysosomal membrane-stabilizing agent (methylprednisolone) in protecting kidneys from ischemic damage by preventing lysosomal enzyme release was assessed. Results showed conclusively that urinary enzyme activities of beta-galactosidase and N-acetyl-beta-glucosaminidase are valuable indicators of renal cellular damage and functional outcome after ischemic injury, and that methylprednisolone at a dose of 30 mg/kg, given intravenously 1 hour before a 1-hour period of normothermic ischemia, protects the kidney both biologically and morphologically, by reducing the excretion of lysosomal enzymes after revascularization.

Acetylglucosaminidase↗
PubMed1983

Comparison of three low-nitrogen diets containing essential amino acids and their alpha analogues for severely uremic children.

Six infants, 4.5 to 19 months old, whose creatinine clearance was less than 6 ml/min/1.73 m2 received, successively, three low-nitrogen diets. Diet A contained 9.3 g of human milk protein; and diet B, 4.2 g of human milk protein plus synthetic essential amino acids. Diet C was the same as B except that five essential amino acids were replaced by alpha-keto and hydroxy analogs. Serum urea decreased as the infants were transferred from diet A to diets B and C, and the serum urea/creatinine ratio decreased from diet A to diet B and from diet B to diet C. Urea appearance was 14.8 +/- 4.5, 9.1 +/- 4.3, and 6.9 +/- 1.7 mmoles/day, with diets A, B, and C, respectively. Weight gain was also lowest with diet C, as was the difference between nitrogen intake and urea nitrogen appearance, an indicator of nitrogen balance. Plasma free amino acids were not modified by diets A and B, but valine, leucine, and the plasma free essential amino acid pool decreased significantly with diet C.

Amino Acids, Essential↗
PubMed1983

Comparative toxicity of adriamycin and adriamycin-DNA in rats.

Adriamycin (ADR) can be linked to DNA without loss of its antitumoral activity while reducing the acute toxicity of free ADR (Deprez--DeCampeneere et al., 1979, 1980). However, the potential chronic toxic effects of both forms of ADR are poorly documented. For such a study, it is necessary to establish the sequence of treatment allowing the administration of a sufficient amount of drugs to induce chronic toxicity and a schedule leading to prolonged survival of animals. In this study, 24 Lewis rats were injected twice a week during four weeks with either free or DNA-linked ADR, and three dose levels were tested: 4, 2 and 1 mg/kg. Our results indicated that the total cumulative dose of ADR should not exceed 8 mg/kg over one month, if prolonged survival is desired. The binding of ADR to DNA seemed also to reduce the acute toxic effects induced by free ADR, in rats. However, such a beneficial effect was not observed when the chronic nephrotoxicity was considered since characteristic renal lesions were observed in all long-term survivors, whatever the dose and the form of ADR received.

Animals↗
PubMed1981

Urea synthesis in moderate experimental uremia.

Urea synthesis rates (USR) were examined in relation to individual variations in energy and nitrogen intakes. Rats made uremic by 7/8 nephrectomy (N = 12) were pairfed with sham-operated controls (N = 11) and divided into two diet groups: diet 1 (4 kcal/g, 18% protein) and diet 2 (4 kcal/g, 42% protein). Nitrogen intake (NI) and energy intake (EI) were varied according to the quantity of feed given and the addition of a nonprotein gavage supplement. The USR was determined by 14C-urea excretion during four periods when EI ranged from 20 to 50 kcal/day and NI ranged from 150 to 675 mg/day. Although USR did not correlate directly with either dietary protein or energy, the percent of protein-derived calories allowed the prediction of USR from NI. Fractional urea synthesis was not related to NI but rather to total EI. The nonlinear regression described a critical EI of 30 kcal/day below which USR increased to 75% of the NI. USR was not different between control and uremic animals. These data suggest an advantage in maintaining an appropriate protein: energy ratio (2.5 g per 100 kcal) to minimize the fractional urea synthesis. The utilization of nitrogen at different levels of protein and energy intake was not altered by the state of experimental uremia.

Animals↗
PubMed1981

Effectiveness of the adriamycin-DNA complex in kidney allograft immunosuppression.

The chemotherapeutic effectiveness of the lysosomotropic Adriamycin-DNA complex has been demonstrated experimentally. This study evaluated the immunosuppressive activity of the complex on renal allografts in rats of the Buffalo-Lewis strain. Six rats receiving no treatment served as a control. Five rats received DNA along (at a dose equivalent to that in the complex), seven received the Adriamycin-DNA complex (molar ratio of DNA mononucleotide to Adriamycin, 20:1) and five were given free Adriamycin. Adriamycin, free or linked to DNA, was injected as follows: 2 mg/kg on days 2, 6 and 9 and 1 mg/kg on day 13 after transplantation. The Adriamycin-DNA complex prevented renal allograft rejection in the early postoperative period, by delaying for more than a week, the increase in serum creatinine levels in animals receiving transplants. Histologic examination of renal grafts in these rats confirmed the reduced severity of acute cellular rejection. There was also functional and morphologic evidence of reduced toxicity of Adriamycin when linked to DNA. The beneficial effect of such a drug should be attributed to its lysosomotropic mechanism of activity.

Animals↗
PubMed1980

Plasma and muscle free amino acids in children at the early stages of renal failure.

Plasma and muscle free amino acid analyses have been performed on four groups of children with different levels of renal failure. Mean plasma creatinine of the groups 1 to 4 was respectively 1.3, 2.3, 3.3, and 4.9 mg/100 ml. Significant but different alterations of plasma and muscle amino acid pattern were found in the four groups of patients. In plasma, aspartic acid, citrulline, OH-proline, 1- and 3-methyl histidine were regularly increased, while threonine, valine, phenylalanine, isoleucine, leucine, tryptophane, tyrosine, and tyrosine/phenylalanine ratio were generally decreased. In muscle, glutamine was usually increased and alanine, valine and valine/glycine ratio decreased; significant increase of total amino acid content was only noted in group 4. Some amino acid alterations became worse with renal failure such as 3-methylhistidine increase or tyrosine/phenylalanine decrease, but group 3 patients had the greatest number of individual amino acid alternations. This group of patients also had the highest protein intake. Relationship between growth velocity and muscle amino acid pattern was found, a poor growth rate was associated with an increase of nonessential and essential amino acids with the exception of valine.

Adolescent↗