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Biomedical subjects

J Delorme

Publications and source records attributed to J Delorme.

36 records · Page 2Linked to original sources

Developmental patterns of levels of corticosterone and of corticosterone binding in the serum of female rats: effects of ovariectomy and adrenalectomy.

Corticosterone concentrations and corticosterone binding in the serum were studied in immature female rats, using radioimmunoassay and batchwise gel equilibrium techniques. A parallel developmental pattern was found for corticosterone levels and its serum binding with a neonatal drop, followed by low levels until 12 days of age and a rise between 12 and 28 days of age. Effects of adrenalectomy, of ovariectomy, of the combined operation and of sham-operations, performed at various ages, were also studied. Adrenalectomy performed at 5 days of age did not decrease serum corticosterone concentrations within a 6-day period whereas it did in older rats. Complete disappearance of corticosterone from the blood occurred only in adult rats after combined adrenalectomy/ovariectomy. Ovariectomy and sham-operations in the younger age groups (5-15 days) caused a gradual increase in corticosterone concentration with maximal values 6 days after operation or later. The response of corticosterone secretion to these operations became more moderate and quicker, i.e. more adult-like, at 28 days of age, the age where corticosterone concentrations in intact rats also seemed to reach a plateau at an adult-like level. Corticosterone binding changed only marginally after ovariectomy or sham-operations until 28 days of age, when an increase was induced by these operations. After adrenalectomy or combined adrenalectomy/ovariectomy, however, marked increases in serum binding of corticosterone were always seen. In summary: though a parallel developmental pattern of serum corticosterone levels and corticosterone binding was seen in the maturing rat, interference with the normal condition causes divergent responses in these two parameters. Moreover, the responses vary with maturational age.

Adrenalectomy↗

The serum competitor of oestrogen--rat alpha 1-foetoprotein interactions. Identification as a mixture of non-esterified fatty acids.

The novel endogenous serum ligands of rat alpha 1-foetoprotein previously demonstrated in different mammalian sera were identified by g.l.c.--mass-spectrometric methods as a mixture of non-esterified long-chain and predominantly unsaturated fatty acids. Detailed comparative analyses of these ligands extracted from foetal- and pregnant-rat sera, rat amniotic fluid and foetal human sera are presented. We also show that an important fraction of these ligands remains associated with the rat alpha 1-foetoprotein after purification; analyses are given for the composition of this lipid moiety of the foetoprotein. The physiological relevance of these results is discussed.

Aging↗

Computer system for a hospital microbiology laboratory.

An online computer system has been developed for a university hospital laboratory in microbiology that processes more than 125,000 specimens yearly. The system performs activities such as the printing of reports, fiscal and administrative tasks, quality control of data and technics, epidemiologic assistance, germ identification, and teaching and research in the different subspecialties of microbiology. Features of interest are smooth sequential transmission of clinical microbiologic test results from the laboratory to medical records, instantaneous display of all results for as long as 16 months, and updating of patient status, room number, and attending physician before the printing of reports. All data stored in the computer-file can be retrieved by any data item or combination of such. The reports are normally produced in the laboratory area by a teleprinter or by batch at night in case of mechanical failure of the terminal. If the system breaks down, the manually completed request forms can be sent to medical records. Programs were written in COBOL and ASSEMBLY languages.

Computers↗

[Free polyunsaturated fatty acids, estrogens and fetoproteins].

In the course of the foetal development of numerous animal species elevated serum concentrations of alpha-1-foetoprotein (AFP) are observed. The level of this foetal protein decreases after birth, but reappears in several pathological cases characterized by a cellular proliferation, in particular in neoplasia such as hepatoma and teratoblastoma. Little was known until 1971 on the biological role of this carcino-embryonic antigen. It has been since evidenced [Nunez and al., 1971, C.R. Acad. Sci., Paris, 273, 834-841]. That rat and mouse AFPs bind oestrogens with high affinity (Ka = 10(8) M-1) [Savu and al., 1972, F.E.B.S. Let., 22, 113-116]. Human AFP does not possess this property. We have recently shown [Benassayag and al., 1977, Steroids, 30, 771-785] that the sera from pregnant rats, rat and human foetuses contain compounds which behave as competitive inhibitors of the estrogen binding on rat or mouse AFP. We have subsequently identified this substances as a mixture of non-esterified fatty acids (NEFA) [Vallette and al., XXVII Colloquium "Protides of the biological fluids", Bruxelles, H. Peeters Ed., Pergamon Presse, 1979]. We have measured [BENASSAYAG and al., Oncodevelopmental biology and medicine, in press] the association constants of each NEFA of the serum mixture with rat AFP, the polyunsaturated fatty acids (PUFA) (C 20:4, C 22:4, C 22:6) show the highest association constants (Ka = 10(5)-10(6) M-1). We have also confirmed that human AFP binds the PUFA with high affinity. The biological perspectives opened up by these novel data will be discussed.

Animals↗

High affinity of nonesterified polyunsaturated fatty acids for rat alpha-fetoprotein (AFP).

We have recently demonstrated that a mixture of nonesterified long chain fatty acids, mainly polyunsaturated, which are extracted under certain conditions from either whole mammalian sera or from pure rat alpha 1-fetoprotein (AFP), interfere with rat AFP-estrogen interaction. We present here a quantitative study of the association constants for the binding to AFP of these different fatty acids. We show important differences among them, the polyunsaturated ones displaying higher association constants (Ka approximately 10(7) -- 10(8) M-1) than the monounsaturated (Ka approximately 10(6) M-1) or the saturated (Ka approximately 10(4) -- 10(5) M-1) compounds. Moreover, though all the fatty acids identified in rat serum or rat AFP extract are more or less tightly bound by rodent AFP, only some of them can compete for exogeneous estrogens complexed to this highly estrophilic macromolecule.

Animals↗

Relations between fatty acids and oestrogen binding properties of pure rat alpha 1-foetoprotein.

A delipidation procedure based on treatment with charcoal at pH 3 has been applied to highly purified rat alpha 1-foetoprotein preparations. The oestrogen binding properties of the delipidated proteins have been studied with an equilibrium dialysis technique, and compared with the properties of the untreated foetal protein, as well as those of preparations reconstituted from the defatted alpha 1-foetoprotein and the removed lipids. An important increase has been evidenced for the binding levels of oestrone, oestradiol-17 beta and diethylstilboestrol by the delipidated alpha 1-foetoprotein. A reversal of this effect has been obtained by incubating the delipidated protein either with the lipids extracted from the purified alpha 1-foetoprotein or with a potent competitor of the rat alpha 1-foetoprotein-oestrogen interaction, designated as 'L', previously demonstrated and isolated from whole rat sera, and tentatively characterized as a mixture of fatty acids. Scatchard analysis of the oestrone and oestradiol-17 beta binding parameters show that the enhanced fixation of the hormones after defatting is primarily due to a two-fold increase of the apparent number of binding sites/mol alpha 1-foetoprotein. The results are interpreted in terms of the probable, at least partial, identity between the lipids closely associated with the pure alpha 1-foetoprotein and the fatty acid mixture 'L' isolated from whole sera. The possible biological role of complex interplay between oestrophilic alpha 1-foetoproteins, phenolsteroids and fatty acids in the control of oestrogen levels during development is discussed briefly.

Animals↗

Anaerobic mediastinitis and septic shock secondary to esophageal perforation.

The authors report unusual complications arising from the ingestion of a small fish bone by a 68-year-old man. These included mediastinitis, empyema, pericarditis and septic shock, probably secondary to a small perforation of the esophagus. After appropriate surgical drainage, antibiotic therapy and supportive therapy the patient made a good recovery.

Aged↗

Rat and human embryo and post-natal sera contain a potent endogenous competitor of estrogen-rat alpha-fetoprotein interactions.

A highly active inhibitor of the binding of estrone and estradiol-17beta to rat alpha-fetoprotein is demonstrated for the first time in embryo, immature and adult rat sera as well as in fetal and adult human sera. The competitive character and the narrow specificity of this inhibition effect is shown. The major compound responsible for this activity is isolated by successive column Sephadex LH20 and thin layer chromatography: it is characterized as a nonpolar, nonphenolic, dialysable and thermostable substance, unreactive towards anti-estrone and anti-estradiol-17beta antibodies. The possible biological role of an endogenous non-estrogen ligand of rodent fetoproteins is discussed.

Adrenalectomy↗

Yersiniosis in children.

Sixty-five strains of Yersinia enterocolitica were isolated from stool specimens obtained from 35 patients over a 12-month period. The microbiologic characteristics and drug sensitivities are reported and the clinical patterns of disease associated with the organism are described. Gastroenteritis affecting infants and young children is the most frequent manifestation. The data for 1972 show the same epidemiological trend as in preceding years.

Adolescent↗