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Biomedical subjects

J Leger

Publications and source records attributed to J Leger.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Prophylaxis of vitamin D deficiency in hypothyroidism in the newborn infant].

This study deals with the relationship between the occurrence of hypercalcemia and the administration of prophylactic doses of vitamin D in children with hypothyroidism, before and during L-thyroxine (LT4) treatment. The goal of the study was to determine the dosage of vitamin D necessary to prevent rickets without inducing hypercalcemia. There was a 23% prevalence of hypercalcemia at the time of the diagnosis of hypothyroidism by screening whereas it was 21% in the children who were not given vitamin D during the first 3 months of LT4 treatment. This figure was significantly higher in those who were given vitamin D during the first 3 months of treatment and reached 70%. However, one of the 19 children not given vitamin D presented with biological signs evoking vitamin D deficiency. In conclusion, in hypothyroid infants, vitamin D should be administered carefully during the first 6 months of treatment and restricted to children at risk for developing vitamin D deficiency.

Calcifediol↗
PubMed1988

[Fasting].

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Fasting↗
PubMed1988

[Raw vegetables].

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Cellulose↗
PubMed1988

[Fruits].

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Fruit↗
PubMed1988

Ventricular myosin of the shrew Crocidura russula, correlation with contractile properties.

The present study demonstrates that in the shrew ventricular muscle the speed of tension development and relaxation, as well as twitch duration, are much shorter than in the guinea-pig. It also shows that ventricular myosin of the shrew has a high Ca2+-activated ATPase activity and that it is composed of alpha-type heavy chains. Namely, the native molecule is a V1 variety of myosin. These findings advance our knowledge on an as yet uncharacterized mammalian heart and further demonstrate the correlation between mechanical properties and myosin type in heart muscle.

Animals↗
PubMed1988

Control of thyroglobulin secretion in patients with ectopic thyroid gland.

Serum thyroglobulin (Tg) measurements were performed in 17 children with congenital hypothyroidism due to an ectopic thyroid gland before therapy and during follow-up. Data were analysed in four periods according to duration of therapy and compared to results obtained in a group of 51 normal children aged 1 month to 6 yr. At diagnosis serum Tg was higher than the mean normal value measured at a similar age. We observed a rapid and parallel decrease of both Tg and thyroid-stimulating hormone during the early weeks of therapy. However, Tg was always detectable in the serum of treated (euthyroid) patients. After 34 months of therapy serum Tg was 11.4 +/- 1 ng/ml, a value significantly different (p less than 0.001) from that obtained in normal controls of similar age (23.5 +/- 3 ng/ml). In nine treated children aged more than 2 yr, thyroid-stimulating hormone and Tg were increased after a brief period of decreased L-thyroxine dosage. These data indicate that ectopic thyroid tissue does not involute during thyroxine therapy and, in response to elevations of serum thyroid-stimulating hormone, can be stimulated to secrete Tg.

Child↗
PubMed1988

[Transient neonatal hyperthyrotropinemia].

The systematic screening for congenital hypothyroidism allowed to better precise the transient abnormalities of thyroid function and to interpret their mechanisms and frequency. This study analysed the transient TSH increase observed in 74 children between 1982 and 1987. Eighteen children presented with an obvious disorder, most often iodine intoxication. In 31 cases, iodine poisoning, was likely, according to history. No precise etiology could be found in 25 cases. In 7 children, L-thyroxine treatment was necessary, for various durations.

Congenital Hypothyroidism↗
PubMed1988

[In vitro bacteriostatic and bactericidal effect of ciprofloxacin and others quinolone derivatives on Campylobacter jejuni].

The in vitro bacteriostatic (MIC) and bactericidal (MBC) activities of ciprofloxacin and seven other quinolone derivatives on Campylobacter jejuni from human origin were determined. Ciprofloxacin, pefloxacin and rosoxacin exhibited the best bacteriostatic and bactericidal activities. For the three compounds the MIC90 was less than or equal to 0.33 microgram/ml while the MBC90 was resp. 0.36, 0.56 and 0.56 microgram/ml. The MBC values were always significantly higher than the MIC values (P less than 0.001). An attempt was made to select strains with an induced resistance against the quinolone derivatives.

Anti-Bacterial Agents↗
PubMed1987

Hypothyroidism in children with filter paper TSH of 30 to 50 microU/ml at initial screening. Implication of the TSH cut-off point for recalling of infants at risk.

In a systematic screening of newborns in France during the period from 1979 to 1983, 959 infants with hypothyroidism were detected. In 16 cases of confirmed hypothyroidism the initial filter paper TSH (FP-TSH) was between 30 and 50 microU/ml. These cases emphasize the necessity of keeping a "security zone" for FP-TSH value between 30 and 50 microU/ml and of recalling these patients for a second test filter paper TSH.

Child, Preschool↗
PubMed1987

[Myelofibrosis. Pathology of the microenvironment].

Myelofibrosis is the most representative model of the association between the hemopoiesis failure end the abnormalities of the myeloid microenvironment. Long term culture in Dexter's liquid system is a good model for the in vitro study of myeloid differentiation. An experimental in vitro system using an irradiated under layer and aplastic patients plasma has yielded some preliminary results allowing the production of megakaryocytic colonies. Close contact between these colonies and the fibroblasts or stromal cells in the adherent layer could probably be used for the study of the interrelation between the stromal abnormalities and myeloid pathology.

Hematopoietic Stem Cells↗
PubMed1986

Purification and characterization of myosins from human and rabbit skeletal muscles by using specific monoclonal antibodies.

By using immunoaffinity column chromatography slow (I) and fast (IIA, IIB) myosins were isolated from human (vastus lateralis) and rabbit (tibialis anterior, psoas and conoidal bundle) skeletal muscles. The peptide pattern revealed that slow (I) and fast (IIA, IIB) myosin heavy chains are quite distinct, as are those from pure slow (conoidal bundle) and fast (psoas) rabbit skeletal muscles. Unlike Billeter et al. (1981) the authors observed that fast human myosins were always associated with a small amount of slow myosin light chains. The fast myosins (IIA, IIB) from rabbit tibialis anterior muscle did not appear very distinct and contained only fast myosin light chains. These myosins were different from the IIB myosin from the psoas muscle. Ten per cent of the fibres revealed histochemically as fast IIA also reacted with an anti-slow myosin antibody. The classical histochemical techniques appear inadequate to demonstrate the existing differences among fibre types, but the monoclonal antibodies hold promise.

Animals↗
PubMed1986

Myosin detection in human myometrium with a monoclonal antibody.

A monoclonal antibody was prepared from a mouse immunized with human gravid uterine myosin. This monoclonal antibody is specific for the myosin heavy chains of human smooth muscle as determined by radioimmunoassay and immunoblotting experiments. Frozen cryostat sections isolated from different uterine regions were studied by immunofluorescence in order to detect myosin distribution within cells of nongravid, gravid, and pathologic human uteri. Myosin was detectable in the cytoplasm of all uterine muscle cells. No fiber heterogeneity with regard to myosin distribution was detected among or within the different uterine regions, regardless of which physiologic or pathophysiologic situation was studied. A large increase in the cell size was observed during pregnancy. These preliminary observations suggest the value of further production of monoclonal antibodies specific for the different putative molecular variants of uterine myosin and their potential use in identifying individual cells containing different myosin variants.

Antibodies, Monoclonal↗
PubMed1986

Long-term expression of isomyosins and myoendocrine functions in ectopic grafts of atrial tissue.

Tissue fragments of newborn rat atria were transplanted under the dorsal skin or into the bed of the anterior tibial muscle of nude mice. After 5-11 weeks, the grafts, which had reorganized into beating atrium-like structures, were analyzed and compared to ventricular tissue transplanted the same way. As revealed by monoclonal antibodies against alpha- and beta-type myosin heavy chains, atrial grafts retained a typical pattern of myosin expression distinct from that of ventricular grafts. The majority of ectopic atrial myocytes contained specific atrial granules in which cardiodilatin-immunoreactive material has been localized. Specific granules and cardiodilatin immunoreactivity were not found in myocytes of ventricular grafts. We conclude that the long-term maintenance of isomyosin expression and of the myoendocrine function of atrial tissue is largely independent of the anatomical environment.

Animals↗
PubMed1985

Fractionation and characterization of two molecular variants of myosin from adult human atrium.

Monoclonal antibodies (MAb) to myosin heavy chains were prepared from one adult human ventricular myocardium. Several of these MAb reacted by indirect immunofluorescence in a heterogenous way on cryostat transverse sections of fibers from human atrial myocardium, suggesting the presence of different forms of myosin within the human atrium and prompting the further use of the MAb to attempt to fractionate preparations of native atrial myosins. Two molecular variants of human atrial myosins or myosin fragments were thus separated by immunoaffinity chromatography performed with one antiventricular myosin MAb. Seven MAb located at different positions along the myosin heavy chains, as deduced from blotting and immuno-electron microscopy experiments, were used to characterize the structural relationships between the separated human atrial isomyosins and between each of them and the main human ventricular myosin. As deduced from competitive radioimmunoassay measurements, the primary structures of the two atrial myosins differ in at least five antigenic determinants and share at least two of them; similarly located structural differences were observed between one of the atrial myosins and the ventricular myosin. Conversely, the primary structures of the other atrial myosin and of the ventricular myosin differ in at least two antigenic determinants and share at least five of them. Differences in the primary structures of the human cardiac myosins were confirmed by analysis of the peptides produced by limited enzymatic digestion of the heavy chains; a few peptide differences were consistently found. To summarize the two separated forms of atrial myosin have different heavy chains, but they have similar if not identical in vitro ATPase activities and the same light chains. One of the atrial myosins is immunologically close to the ventricular myosin, but they each differ with respect to their heavy chains, light chains, and enzymatic activities.

Adenosine Triphosphatases↗