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M Vernet

Publications and source records attributed to M Vernet.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Erythrocyte ferritin].

Red cell ferritin is a residue of erythroblast ferritin. It reflects the balance between the iron supply to the erythroid marrow and the need for haemoglobin synthesis. Erythrocyte ferritin can be measured in haemolysates after discarding plasma and leucocytes by different methods. The decrease in erythrocyte ferritin content indicates manifest iron deficiency anaemia. Ferritin levels do not appear to be influenced by inflammation, infection, tissue necrosis or tumors and may be a reliable indicator of iron status in inflammatory diseases. Erythrocyte ferritin is markedly increased in patients with iron overload allowing early diagnosis of hereditary haemochromatosis and the monitoring of phlebotomy therapy. Finally, in some pathologies erythrocyte assay is a more reliable indicator of the iron status than serum ferritin.

Anemia↗
PubMed1992

Expression of microinjected DNA and RNA in early rabbit embryos: changes in permissiveness for expression and transcriptional selectivity.

Gene expression in rabbit early development was investigated by microinjecting LacZ DNA and LacZ RNA in 1-cell and 2-cell embryos. Expression of LacZ DNA could not be obtained before 30-36 hpf, although synthetic LacZ RNA was translated from 12 hpf at the least. The onset of expression of microinjected DNA correlated with the 8- to 16-cell stage. This suggests that before this stage, there is a general negative control of gene expression. The arrest of in vitro development at the 2- to 8-cell stages did not inhibit LacZ expression, which still occurred at 33 hpf. In addition the inhibition of the first cleavage by nocodazole resulted in LacZ expression in 1-cell embryos. Expression of microinjected DNA thus occurs at a fixed time after fertilization and is independent of cleavages and of the second and subsequent DNA replications. Therefore, the changes in permissiveness for the expression of microinjected DNA in rabbit embryos are reminiscent of those in mouse embryos. Transcriptional selectivity in rabbit embryos was compared to that in early mouse embryos. In both species, Sp1-sensitive promoters were active and the promoter of simian virus 40 did not require far upstream enhancers before late cleavage stages; genes driven by the -447, +563 region of murine leukemia virus were repressed. In rabbit, however, the H-2Kb promoter active in mouse was silent. Altogether, the results illustrate a remarkable conservation of the characteristics of the transcription in early rabbit and mouse embryos and the independence of its resumption from the pattern of cleavage.

Animals↗
PubMed1992

Changes in permissiveness for the expression of microinjected DNA during the first cleavages of mouse embryos.

LacZ DNA and LacZ RNA were microinjected during the first cleavages of embryos. LacZ DNA was not expressed before 18-19 h post insemination (hpi) but LacZ RNA was translated. Before 22 hpi LacZ DNA was expressed in the pronuclei of the one-cell embryos and the polypeptides of the minor, but not the major activation period of the genome were synthesized. This suggests a negative control of transcription before 18-19 hpi and demonstrates that its resumption is independent of the first cleavage and of the major activation of the genome. At the time of the minor activation the eggs contain the trans-acting elements to express a variety of genes that they do not express. It may indicate that, the minor and the major activation of the genome are differently controlled.

Animals↗
PubMed1992

[Sialic acid deficiency transferrin: a very promising biological marker, sensitive to chronic alcoholism].

Chronical alcohol ingestion may induce conformational molecular modifications of plasma transferrin: alcohol modifies the content of its carbohydrates. The abnormal transferrin contains reduced amounts of carbohydrates, especially sialic acid, constituting its terminal trisaccharides biantennary chains. Plasma levels of partly deficient or asialotransferrin increase in chronically drinkers. In English speaking countries, it is called carbohydrate deficient transferrin or CDT. A positive correlation is obtained between the plasmatic concentration of CDT and the amount of ingested alcohol. Positivity and sensitivity of CDT are superior to those other usual biological parameters. The CDT quantitation may be proposed for the detection and the follow-up of alcohol drinkers, in order to evaluate the degree of intoxication, and during the period of withdrawal.

Alcoholism↗
PubMed1992

Modification of the selected method for the determination of serum iron. Substitution of bathophenanthroline by ferene S.

The previously selected method (1977) for the measurement of iron in human serum has been modified by the working group on Iron and Iron-Transport Proteins (Sociéte Française de Biologie Clinique). Ferene S is used as the chromogen, it is more sensitive and cheaper than bathophenanthroline. The sample size has been reduced from 2 to 0.5 ml. No interference could be shown with high concentrations of bilirubin, copper or hemoglobin.

Animals↗
PubMed1992

[Hemodialysis and ferritinemia].

Iron-deficiency is a common phenomenon in chronic renal diseases and haemodialysis patients, a treatment with iron or transfusions is always provided in an early preventive way; yet, an overload may appear. Serum ferritin, in spite of analytic variability, remains at the present time a good witness to appreciate patients' iron stores. Authors report the results obtained with four commercial reagents in healthy population and in haemodialysed children or adults. The comparison of results for this parameter shows that haemodialysed sera, with or without treatment, have the same behaviour with reagents as those of healthy subjects.

Adult↗
PubMed1991

Transcriptional selectivity in early mouse embryos: a qualitative study.

The mouse zygotic genome is activated at the 2-cell stage. At this stage, microinjected DNA can be expressed and its transcription, analysed qualitatively with LacZ reporter genes, has the following characteristics (i) Sp1-sensitive promoters are active; (ii) the SV40 early promoter does not require upstream enhancers; (iii) genes driven by the -447, +563 region of murine leukemia virus (M-MuLV) are repressed and; (iv) activation of promoters is possible as shown for the promoter of acetylcholine receptor alpha-subunit by MyoD. This transactivation can occur before the formation of the zygotic genome. The transcriptional selectivity of 2-cell embryos also characterizes oocytes and 4-cell embryos. Therefore the elements involved are present in the oocytes and they persist after fertilization. This transcriptional selectivity has numerous common characteristics with that in EC cells, and may be indicative of a genetic control program specific for multipotential cells.

Animals↗
PubMed1990

[T lymphoblastic leukemia with leukemoid reaction or the extramedullary blast crisis of Philadelphia chromosome-negative chronic myeloid leukemia? Comments apropos 2 cases].

Reactive leukocytosis has been reported in patients with non-Hodgkin's lymphoma of different histologic types. On the other hand, the blastic crisis of chronic myelocytic leukemia (CML) can sometimes be localized outside the bone marrow and simulate lymphoma, particularly when the blasts are of lymphoid lineage and the blastic crisis is the presenting feature of the disease. We report two patients in whom the differential diagnosis between lymphoblastic lymphoma with reactive leukocytosis and blastic crisis of CML outside the bone marrow was raised. They were two males aged 32 and 22 years, respectively, with lymphadenopathy (and one with splenomegaly), who were initially diagnosed of T lymphoblastic lymphoma. In both cases, leukocytosis was detected with myelemia and dysgranulopoiesis in the onset in one of them and when lymphadenopathy reappeared after remission in the other one. In addition, one patient had marked eosinophilia. In the bone marrow there was marked granulopoietic hyperplasia, with a reduction of fatty cells, and the granulocyte alkaline phosphatase index was reduced. However, the cytogenetic study did not disclose the existence of Philadelphia (Ph) chromosome, and bcr/abl molecular rearrangement was also not observed in the molecular study of both cases. We discuss the basic aspects of differential diagnosis between T lymphoblastic lymphoma with leukemoid reaction and T lymphoid lymphadenopathic blastic crisis of Ph-negative, bcr/abl-negative CML.

Adult↗
PubMed1990

[Hypothyroid myopathy. A clinical and histologic prospective study of 19 patients].

Nineteen patients with primary hypothyroidism were prospectively studied before starting replacement therapy with thyroid hormones. Most patients had mild to moderate muscle symptoms: generalized muscle weakness, myalgia and cramps, and increased serum levels of muscle enzymes. In two patients these features were the motive for consulting the physician. The patients with muscular features had significantly higher plasma levels of lactic dehydrogenase and aldolase than asymptomatic patients. The major histological muscle findings were atrophy of type II fibers, abnormalities in the oxydative pattern of muscle cells, and glycogen deposition. In the biochemical investigations an increased muscle glycogen with reduced activity of the glycolysis and glucogenolysis enzymes were found. The patients with more marked histological abnormalities had lower levels of thyroid hormones, but the differences did not reach significant values. Five patients in euthyroid status after 12 months of therapy underwent a new biopsy. Although the remaining clinical and laboratory parameters had returned to normal, some of the histological muscle abnormalities persisted. This finding leads to the suspicion that the lack of thyroid hormones may induce irreversible structural damage in skeletal muscle.

Adult↗
PubMed1990

Biochemical and histochemical adaptation to sprint training in young athletes.

The purpose of the present study was to investigate the effects of 8 months of a specific and controlled sprint training programme on three groups of young athletes (two groups of males and one of females). Biopsies of vastus lateralis were taken before and after the period of training. The type percentage and diameter of the fibres, as well as the glycogen content and the activities of the enzymes of glycogen metabolism (glycogen synthase and glycogen phosphorylase), glycolysis (phosphofructokinase, pyruvate kinase, aldolase and lactate dehydrogenase), oxidative metabolism (succinate dehydrogenase) and creatine kinase and aminotransferases were studied. The results show an increase in the percentage of type I fibres and an increase in the diameter of both fibre types. A significant increase was also observed in glycogen content, and in the activities of glycogen synthase, glycogen phosphorylase, phosphofructokinase, pyruvate kinase, succinate dehydrogenase, aspartate aminotransferase and alanine aminotransferase. We conclude that a long period of sprint training induces a biochemical muscle adaptation to anaerobic exercise. This metabolic adaptation is followed by a morphological adaptation, although this is probably not as specific as the biochemical one.

Adaptation, Physiological↗
PubMed1990

In vivo activation by ultraviolet rays of the human immunodeficiency virus type 1 long terminal repeat.

It has been previously shown in vitro that the human immunodeficiency virus type 1 long terminal repeat (LTR) is activated by ultraviolet irradiation. In order to analyze if a similar effect could occur in vivo, transgenic mice carrying the lacZ gene under the control of the viral LTR were irradiated at 280-300 and 254 nm. These mice spontaneously expressed the transgene in the epidermis and the lens of both adults and embryos. Irradiations caused a significant increase in skin beta-galactosidase activity. This phenomenon might be involved in viral activation and could be of interest in regard to the skin pathology observed during an HIV infection.

Animals↗
PubMed1989

Effects of ethanol and acetaldehyde on the enzymes of glycogen metabolism.

This report concerns a study of the effect of ethanol and acetaldehyde on the regulatory enzymes of glycogen metabolism. It demonstrates an inhibition of glycogen phosphorylase kinase at pH 6.8 at a very low concentration of ethanol. There was no effect of acetaldehyde on this enzyme. Neither ethanol not acetaldehyde has been shown to have any effect on glycogen synthase, glycogen phosphorylase, protein phosphatase or independent and cAMP-dependent protein kinases. This inhibition could explain the high concentration of glycogen in the muscle tissue of chronic alcoholics that is found when ethanol is present in skeletal muscle.

Acetaldehyde↗
PubMed1989

[Reference values of erythrocyte ferritin in children and adults].

The erythrocyte ferritin content was measured in 183 healthy subjects in age from 4 to 68 years; 80 were male and 103 were female. In children between the ages of 4 and 12 years there is no significant difference in the mean value between boys and girls. In females the erythrocyte ferritin concentration is independent of age. After 12 years of age the erythrocyte ferritin content is higher in men. Reference intervals were determined by the two quantiles 0.05 and 0.95. The reference interval is 3-24 age by cell in boys between 4 and 12 and females between 4 and 63; the reference interval is 5-38 age by cell in males between 13 and 68 years of age.

Adolescent↗
PubMed1988

[Lactoferrin: biochemistry, physiological roles, and value in human biology].

Lactoferrin and transferrin exhibit very similar structure and biochemical properties but they behave as two distinct antigens and their affinity for ferric ions is not of the same magnitude. The biological functions of lactoferrin are not all well understood. It has strong bacteriostatic properties, it plays a role as a regulator of human granulopoiesis and it is probably involved in the hyposideremia of acute inflammation. Measurement of lactoferrin was first applied in pancreatic juice or duodenal fluid as a diagnostic tool for pancreatic diseases. More recently plasma lactoferrin has been used as an index of total circulating neutrophil pool in hematological disorders and in uremic patients during hemodialysis. Its clinical usefulness is still discussed for the early diagnostic of infectious diseases.

Anti-Infective Agents↗
PubMed1988

[Determination of plasma lactoferrin by the "double sandwich" immunoenzymatic method in heterogeneous phase].

For the determination of lactoferrin in human plasma we describe a double-sandwich immunoenzymatic assay in 3 steps using tubes as the solid phase. The analytical performances are acceptable. Within-run and between-run CVs are respectively 4% and 13%, the lower limit of detection is 8 micrograms/l. Sensitivity and specificity are good. The influence on lactoferrin concentration of time elapsing from blood sampling to separation of plasma from cells was studied in order to define the optimal conditions of storage and centrifugation. The range of concentration obtained on 22 healthy adults lies between 59 and 345 micrograms/l.

Female↗