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Biomedical subjects

J Proust

Publications and source records attributed to J Proust.

At least 37 records · Page 2Linked to original sources
PubMed1985

Plasma ferritin in old age. Influence of biological and pathological factors in a large elderly population.

The effects of biological (age, sex, weight) and pathological factors on plasma ferritin concentrations were documented in 776 unselected elderly patients aged 80.9 +/- 9.7 yr. A marked shift towards high values (159 +/- 142 micrograms/l) was observed in this elderly population together with the persistence of the well-known sex-related difference in ferritin levels (higher levels in men). Twenty-five percent of the population had high levels of ferritin (greater than or equal to 220 micrograms/l) but 75% of these high values (i.e. 18.5% of the population) could be readily explained by their known association with a particular pathology (inflammatory syndrome, renal failure, cardiovascular diseases, alcoholism). Only 6% of the population had unexplained high ferritin concentrations. Therefore, our data strongly suggest that the repeatedly reported increase of ferritin in the aged population is merely related to an age-associated pathology and may not be a normal physiological event occurring during the process of aging.

Aged↗
PubMed1985

Biological and pathological factors affecting plasma gamma-glutamyl transpeptidase and alkaline phosphatase activity in the elderly.

A high percentage of abnormally elevated plasma alkaline phosphatase (AP) and gamma-glutamyltranspeptidase (GGT) was found in a homogeneous population of 741 elderly subjects. The respective role of pathological and biological factors (age, sex, weight) upon the two plasma enzymatic activities has been analyzed. In disagreement with previous reports, it was observed that abnormal AP and GGT values could be readily explained by their association with specific diseases. The apparent relationship between abnormal levels of plasma AP and GGT activities and age, sex or weight reflected merely a different distribution of the pathology according to these biological parameters. In the absence of non-specific elevations of plasma AP and GGT activities with age, the usual reference values for these tests, although established on younger populations, still apply to the aged.

Age Factors↗
PubMed1985

Lymphopenia induced by acute bacterial infections in the elderly: a sign of age-related immune dysfunction of major prognostic significance.

These studies were undertaken to investigate the effect of acute bacterial infections on the absolute number of peripheral blood lymphocytes (PBL) in an elderly population and to evaluate the prognostic significance of a decreased number of PBL in critically ill aged patients. The results show that a significant lymphopenia develops in elderly patients during the course of an acute bacterial infection whereas the same type of acute illness has no effect on the PBL count of younger subjects. The lymphopenia is not related to a particular localization of the infection nor to the type of bacterial pathogen. The prognosis of the bacterial infection is closely linked to the severity of the lymphocyte depletion and its outcome can nearly be predicted by monitoring the variation of the number of circulating lymphocytes during the early course of the disease.

Acute Disease↗
PubMed1985

Age- and sex-associated modification of plasma melatonin concentrations in man. Relationship to pathology, malignant or not, and autopsy findings.

Plasma melatonin concentrations were determined in 757 unselected elderly patients aged 80.9 +/- 9.7 years. The daytime (8-9.30 h) plasma levels of melatonin were in the so-called normal range in only one third of the population whereas 65% of the subjects had abnormal levels of the hormone, most often decreased i.e. less than 0.17 nmol/l (53%) and sometimes increased i.e. 0.43 nmol/l or higher (12%). A control group of healthy elderly subjects showed the same distribution as the entire population. A sex-difference with significantly higher levels of plasma melatonin in elderly women was observed. With respect to pathology and autopsy findings high levels of the hormone correlated with cancer, chronic renal failure, cardiovascular disease, biological inflammatory syndrome and diabetes. Low levels correlated with neurologic disease, tobacco or alcohol addiction. However, some of these relations were found to be sex-related as they were observed in women but not in men. Our data indicate that pineal function seems to be often altered in elderly human subjects and suggest potential diagnostic applications of melatonin determination.

Age Factors↗
PubMed1984

Lethal mutations induced in Drosophila melanogaster by direct or indirect action of pteridines.

The experiments described in this paper show that synthetic pteridines, especially biopterin and pterin, injected directly into Drosophila melanogaster induce recessive lethals. On the contrary, D-neopterin seems to have little effect. A mutagenic effect has previously been shown for an extract of Pieris brassicae in diapause, treated with these pteridines and tetrahydrofolic acid (FH4). It appears that chromosome II is more sensitive to these mutagenic treatments than chromosome X.

Animals↗
PubMed1984

Cumulative effects of age and pathology on plasma carcinoembryonic antigen in an unselected elderly population.

Plasma CEA was measured in 776 institutionalized elderly patients, 593 women and 183 men, whose mean age was 80.8 +/- 9.7 yr. Of these subjects 39 were found to be free of any pathology and were considered as a control group. All the other subjects had a variety of diseases, malignant or not, known or not known to be associated with elevated CEA. This study showed that elderly people in their 80s, in apparent good health, had higher levels of CEA (3.0 +/- 1.4 ng/ml) than younger people. These levels were shown to be significantly increased in a large number of non-malignant diseases. No correlation could be found between elevated CEA values and autopsy finding or drug administration. Using the chi square test, the number of patients with CEA levels greater than 5 ng/ml was found to be significantly higher in chronic renal failure and cancer. Mortality was also found to be higher in patients with CEA levels greater than 5 ng/ml during a 25-month follow-up. Higher levels of CEA in elderly subjects in apparent good health, as well as increase of these levels in a large set of non-malignant pathology, must thus be kept in mind when interpreting data arising from old people because of both the false-positive (healthy elderly subjects) and the cumulative effects of polypathology on plasma CEA.

Aged↗
PubMed1983

Some results of the effect of space flight factors on Drosophila melanogaster.

Two experiments with Drosophila melanogaster males were performed aboard the Salyut 6 orbital station. Mutagenic effects of a 8 day space flight on sex chromosome nondisjunction and intergene recombination in chromosome II were studied. The space flight factors (SFF) increased the frequency of chromosome nondisjunction and recombination. The model experiments showed that the combined effects of vibration and acceleration do not cover the whole spectrum of space flight mutagenic factors. These data suggest that heavy space ions are mainly responsible for the observed effect.

Acceleration↗
PubMed1982

Mutations induced by a hormonal imbalance in Drosophila melanogaster.

Pterin treatment of chrysalids in diapause modified the juvenile hormone- ecdysone ratio. The treatment of Drosophila donor mutant with a mixture of reduced folic acid, pterins and extract of Pierides chrysalids in diapause induced the formation of short sequences, by the intermediary of variations in hormonal balance. The effect of this variation was seen in the germinal lines especially at the gonial stage, where recessive, visible or lethal mutations were induced in the form of clusters. Genetically active fractions were found in the 4S-8S and 18S-28S sedimentation zones after saccharose gradient ultracentrifugation. The short DNA sequences coded for tRNA and rRNA. Consequently, it is there DNA sequences from the Drosophila donor mutant that altered the genetic information of the host. 2 types of recessive visible mutation appeared: those affecting the differentiation of the imaginal discs and those affecting the pigment biosynthetic chain. Recessive lethals were induced by treatment. 3 hypothesis are proposed: the first suggests the formation of a short DNA sequence complexing at a specific locus in the acceptor. The second involves transposable factors belonging to the acceptor itself, behaving as a particular transposable factor. The third supposes the induction of alterations at loci of rRNA and tRNA synthesis at the origin of perturbations in protein synthesis. The present data do not allow us to choose between the 3 hypotheses. In conclusion, it seems that a "hormonal imbalance" can have grave consequences not only for the individual itself but also for its descendants.

Animals↗
PubMed1982

Hybrid dysgenesis in Drosophila melanogaster. I. Further evidence for and characterization of the mutator effect of the inducer-reactive interaction.

1. Several experiments were carried out to study, in the I-R hybrid dysgenesis system, the induction of recessive sex-linked lethal mutations in the progeny of SF females (obtained from crosses of female R by male I) or of RSF females (obtained from crosses of female I by male R). 2. Induced lethals were found in the progenies of SF females but not in those of RSF females. 3. The frequency of induced lethals decreased as SF females grew older. 4. A difference in the frequency of the induced lethals according to the reactive or inducer chromosome origin seemed apparent. Such frequency systematically appeared to be higher for the chromosomes of reactive origin. 5. The correlation between the rate of induced lethals and the intensity of the I-R interaction, as well as the characteristics of the lethals obtained and their non-random distribution, are in agreement with the hypothesis that the mutations are the consequence of the transposition of the I factor.

Animals↗
PubMed1982

HLA and longevity.

One hundred fifty-five healthy nonagenarians, 45 men and 100 women, all French Caucasians, were phenotyped for alleles of the A, B, C, DR loci of the HLA complex. The observed HLA antigen frequencies were compared to those of a control series of 133 males and 179 females whose ages ranged from 10 to 50 years. When comparing the total young and elderly series, no significant differences were observed with respect to HLA antigen distribution or heterozygosity at any of the loci. When taking sex difference into account, however, an excess of the Cw1 antigen was found in the group of elderly females (p less than 0.001) and an excess of the Cw7 antigen in the group of elderly males (p less than 0.001). Of particular significance was the fact that Cw7 belonged in this instance to a phenotypic combination (and most probably to the corresponding haplotype) A1/Cw7/B8/DR3 which was found significantly increased in male nonagenarians (p less than 0.001). These results support the hypothesis that certain HLA haplotypes are associated with survival advantage.

Adolescent↗
PubMed1980

Variations in the recombination rate of Drosophila melanogaster induced by balloon flight.

Drosophila males, heterozygous for b, pr, cn and en genes, were submitted to balloon flights, ceiling time ranging from about 8 hours (flights performed in France) to 22 hours (transmediterranean flight). Effects on recombination were investigated on progeny after breeding with females homozygous for the same genes. The transmediterranean flight and one flight performed in France resulted in a significantly higher recombination rate.

Animals↗