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Biomedical subjects

M Fischbach

Publications and source records attributed to M Fischbach.

142 records · Page 8Linked to original sources
PubMed1978

Lipopolysaccharide induction of IgM antibodies to polyadenylic acid in normal mice.

Lipopolysaccharide (LPS) is able to induce autoantibodies reversibly in normal mice. Single or multiple doses of LPS induced a rapid and dose-dependent rise in antibodies to Poly A from 113 ng to 590 ng/ml serum as determined by Millipore filter radioimmunoassay. The response peaked at day 3 and was over by day 21. No response was seen if the LPS was chemically inactivated or injected into genetically nonresponsive mice. Antibodies were specific for Poly A and were not induced by T cell mitogens. Sucrose gradient ultracentrifugation demonstrated only IgM antibody. Neonatal thymectomy altered neither the immunoglobulin class nor quantity of antibody. Neonatal splenectomy did not affect antibody class but reduced the amount produced. No free Poly A could be detected in circulation after LPS stimulation. These findings suggest that normal mice have B lymphocytes capable of limited and reversible autoantibody production.

Animals↗
PubMedDate not supplied

Induction of the human growth hormone gene placed under human hsp70 promoter control in mouse cells: a quantitative indicator of metal toxicity.

An in vitro test method for general metal toxicity screening was designed, based on the cellular response to stress. The expression of a transfected human growth hormone gene sequence driven by the human heat-shock protein 70 promoter in NIH/3T3 cells was used as marker of noxious contact with metal compounds. Out of a series of 31 metals, 17 were competent for inducing this stress response system. According to the effective concentration and to the intensity of the response, three different clusters of positive compounds emerged and were ranked as strong, intermediate strength and weak inducers. These results correlated well with data from other in vivo and in vitro metal toxicity studies, including LD50 in mice. Apparently the positive/negative compounds also fitted well with data from genotoxicity and carcinogenesis studies on metal salts.

3T3 Cells↗
PubMedDate not supplied

Cellular immunology in the baboon (Papio cynocephalus): examination of structural and functional characteristics of adult and fetal lymphoid cells.

We studied structural and functional characteristics of lymphocytes from adult and fetal baboons (Papio cynocephalus). Flow cytometry with monoclonal antibodies to human lymphocyte antigens and plant lectins was used to define expression of surface antigens on lymphocytes from adult and 140 day fetal baboons (term = 180 days). Major T cell antigenic determinants on adult and fetal baboon lymphocytes were the Tp50, Tp32-45, and p45 glycoproteins detected by monoclonal reagents T11, OKT8, and OKT10 respectively. Baboon T lymphocytes did not react with the OKT3/anti-Leu4 or OKT4/anti-Leu3a reagents which detect, respectively, Tp19-29 and Tp55, major surface glycoproteins on human T lymphocytes. OKT6, which identifies the human TL antigen equivalent on thymocytes, did not react with baboon thymocytes. These data demonstrate major evolutionary divergence between human and baboon T lymphocytes. By contrast, baboon lymphocytes resembled human peripheral lymphocytes in reactivities with several non-T cell reagents. Lectin binding studies revealed substantially fewer peanut agglutinin-and wheat germ agglutinin-binding cells in suspensions of baboon fetal splenocytes and adult peripheral lymphocytes compared with fetal thymocytes. Therefore, maturation of baboon T lymphocytes is associated with loss of surface carbohydrate structures that bind these lectins. Adult and fetal baboon lymphocytes resembled human and murine lymphocytes in their capabilities to respond to mitogens and to produce interleukin-2. As in other species, adult, but not fetal baboon lymphocytes, mediated NK activity against a variety of nucleated target cells. Despite divergence in lymphocyte antigen expression, baboon lymphocyte functional development closely parallels that seen in humans.

Animals↗
PubMedDate not supplied

Haemodialysis adequacy in children: urea kinetic modelling.

The delivered dialysis dose is quantified by KT/V, the normalized whole body urea clearance. Calculations of KT/V are most often performed in single pool urea kinetic modelling, from the post and predialysis serum values. Although the exact levels of KT/V required is a matter of some debate, a minimum KT/V level of 1.2-1.4 is now thought to be necessary.

Age Factors↗
PubMedDate not supplied

The French version of the Childhood Health Assessment Questionnaire (CHAQ) and the Child Health Questionnaire (CHQ).

We report the results of the cross-cultural adaptation and validation into the French language of two health status instruments. The Childhood Health Assessment Questionnaire (CHAQ) is a disease specific instrument that measures functional ability in daily living activities in children with juvenile idiopathic arthritis (JIA). The Child Health Questionnaire (CHQ) is a generic health related quality of life instrument designed to capture the physical and psychosocial well-being of children independently from the underlying disease. Five hundred children were enrolled including 306 patients with JIA classified into systemic (23%), polyarticular (22%), extended oligoarticular (25%), and persistent oligoarticular (30%) subtypes, and 194 healthy children. Both instruments were reliable with intra-class correlation (ICC) coefficients for the test-retest procedure of 0.91 for the CHAQ, and 0.87 and 0.89 for the physical and psychosocial summary scores of CHQ, respectively. Agreement between parents and children evaluated for the CHAQ was high with an ICC of 0.89 for the disability index; weighted kappa coefficients for the 8 domains ranged from 0.61 to 0.72. Convergent validity was demonstrated by significant correlations with the JIA core set of variables (physician and parent global assessment, scores for active joints and joints with limited range of motion, erythrocyte sedimentation rate) for both instruments. Both CHAQ and CHQ discriminated between healthy and JIA children, but only the disease specific CHAQ questionnaire discriminated clearly between the 4 JIA subtypes. In conclusion, the French versions of the CHAQ and the CHQ are reliable, and valid health assessment questionnaires to be used in children suffering from JIA.

Adolescent↗
PubMedDate not supplied

[Williams and Beuren's syndrome with hypertension and associated renal abnormalities (author's transl)].

The authors presented a case of the Williams and Beuren's syndrome, special by the existence of aorta coarctation, high blood pressure, nephrotic syndrome and renal dysplasia. The Williams-Beuren's syndrome is characterised by the association of facial anomalies, mental retardation and supra-valvular aortic stenosis. The case presented in this study demonstrates: -- the symptomatic diversity of the Williams and Beuren's syndrome; -- and the relationship of this syndrome and severe idiopathic hypercalcemia of the infant. The etiopathogenesis is also discussed.

Abnormalities, Multiple↗
PubMedDate not supplied

Biochemical study of whole saliva from children with chronic renal failure.

The biochemical composition of unstimulated whole saliva was studied on ten children suffering from chronic renal failure and who, at the same time, displayed a very low caries activity. Various salivary components were studied before (T) and after (To) dialysis and were compared with similar elements of a control group, as well as with blood values. A mean salivary urea concentration of 513 +/- 210 mg/100 ml was found prior to dialysis, whereas after treatment this value dropped to 241 +/- 82 mg/100 ml, about twice as much as in the control group, 110 +/- 48 mg/100 ml. The mean urea concentrations in blood at T and To were respectively 196 +/- 38 mg/100 ml and 53 +/- 22 mg/100 ml. The various free amino acids in the whole saliva of these patients showed different changes in their concentrations as a result of dialysis, with the basic amino acids being considerably increased. Blood electrolytes remained close to the normal range, although calcium was depleted and magnesium lowered by a factor of 10 when compared before and after dialysis, as well as versus the control group.

Adolescent↗
PubMedDate not supplied

Efficiency of high permeable membranes in hemodiafiltration in children: an optimal method of purification.

Hemodiafiltration (HDF) combines hemodialysis (HD) and hemofiltration (HF) and so allows an optimal purification by combining diffusive process (low molecular weight compounds) with convective mass transport (middle molecular weight compounds). A high permeable membrane is analysed (clearance, extraction coefficient, sieving coefficient) at 30 min and 150 min session time in HD, HF and HDF conditions. There is not a better elimination of urea in HDF versus HD while HDF allows an optimal elimination of uremic toxins in the range of low and middle molecular weight compounds. A high (optimal?) filtrate flow, with a minimal risk, is given by the formula: QUF = 1/3 QB. Sieving coefficient in HF condition of the other membranes generally employed in pediatric HDF demonstrated a great variability for the cut off.

Blood Flow Velocity↗
PubMedDate not supplied

[Sensibility to insulin in obese children (author's transl)].

The glucose and immuno-reactive insulin blood levels of 46 obese children and nineteen controls were measured during the intra-venous glucose tolerance test. The glucose tolerance of the obese children was normal, whereas their blood insulin curves demonstrated hyperinsulinmeia. The sensibility to exogenous insulin in 29 of these children was within normal limits during the hypoglycemic tolerance test induced by injection of intravenous insulin. The factors explaining endogenous insulin resistance have not yet been elucidated.

Adolescent↗