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Biomedical subjects

M Rolland

Publications and source records attributed to M Rolland.

At least 55 records · Page 3Linked to original sources
PubMed1992

N-acetyl oxyntomodulin30-37: pharmacokinetics and activity on gastric acid secretion.

Oxyntomodulin, an intestinal hormone which inhibits gastric acid secretion, is composed of glucagon and a C-terminal octapeptide. This octapeptide mimics the biological activity of the hormone. We have studied the activity of the N-acetyl octapeptide, partially protected against enzymatic degradation, on pentagastrin-, histamine- and milk meal-stimulated secretion in conscious rats and compared it to that of oxyntomodulin and its derivatives. The N-acetylated octapeptide had a 3-fold higher potency than the octapeptide on pentagastrin-stimulated secretion. On histamine-stimulated secretion, the differences between the acetylated and the free octapeptides were that the former displayed a dose-response curve parallel to that of oxyntomodulin and a 4-fold higher potency. The increase in potency appears to be related in part to a decrease in the metabolic clearance rate in vivo (6-fold) and, in vitro, to an increase in half-life (3-fold) when incubated with rat liver plasma membranes. Similarly to the free octapeptide, the acetylated form decreased acid secretion stimulated by a milk meal, when infused before the meal. Acetylation of the Lysine side chains resulted in a totally inactive molecule. The results indicate that acetylating the N-terminus of the octapeptide of oxyntomodulin increases the similarities with the natural hormone.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylation↗
PubMed1992

[Predictive value of non-specific signs of fetal infection in congenital toxoplasmosis].

AIMS: To study the predictive value of 9 non-specific signs for congenital toxoplasmosis. METHOD: The work was carried out as a prospective study comparing non-specific signs in 22 fetuses infected with toxoplasmosis and 59 fetuses free of the disease. RESULTS: Four of the nine parameters were found to be statistically higher in the group of infected fetuses. These are the level of leucocytes (p < 0.05) gamma glutamyl transferase (p < 0.001) total M immunoglobulin (p < 0.0001) and C4 fraction of complement (p < 0.0001). This last sign which is non-specific for infection has never been looked at until now in congenital toxoplasmosis but is seems to be of great importance because its sensitivity is much greater than of all the other parameters that have been used up till now (81%) and the positive predictive value is excellent (72%). On the other hand the value of a raised leucocyte count is a matter for discussion. CONCLUSION: The presence of even one abnormally raised feature in the fetal blood of these non-specific signs is enough to screen for a population which is of high risk for congenital toxoplasmosis and sufficient to change our attitude to treating the condition.

Complement C4↗
PubMed1992

[Biological reference values in the human fetus. 106 cord blood sampling in utero].

The authors give biological reference figures obtained from 106 fetuses that were sampled in utero between the 20th and 34th week of amenorrhoea. These fetuses were considered to be normal because there was no clinical or ultrasound evidence of an abnormality. Furthermore the biological values sought in antenatal testing and the absence of all pathology in the first year of life, confirmed that these were normal fetuses. The result has been expressed as a global figure for all 106 fetuses; then they have been divided up according to the gestational age groups (20-23, 24-27, and 28-34 weeks of amenorrhoea). These biological reference values and their changes as the age of the fetuses advanced are discussed and compared with the figures reported in the literature.

Age Factors↗
PubMed1991

Astomia-agnathia-holoprosencephaly association. Prenatal diagnosis of a new case.

A case of agnathia-astomia-holoprosencephaly with prenatal ultrasound diagnosis at 23 weeks is reported and discussed. This lethal neurocristopathy, well known in mammalians, is rarely observed in humans. Prenatal diagnosis features are intrauterine growth retardation, mandibular absence or major hypoplasia, holoprosencephaly, cyclopia or hypotelorism, and in some instances frontal proboscis. This malformation is usually sporadic, but may be genetically determined as an autosomal recessive trait, since two cases in the same sibship have been reported.

Abnormalities, Multiple↗
PubMed1991

Synthesis and biological activity of 2-phenylethyl ester analogues of C-terminal heptapeptide of cholecystokinin modified in Trp 30 region.

We have tried to evaluate the significance of the tryptophan side chain residue and of the surrounding peptide bonds in the antagonist activity of cholecystokinin analogues lacking the C-terminal amide function and having a D-tryptophan. In order to perform this study, analogues of the C-terminal heptapeptide of cholecystokinin were synthesized by replacing the C-terminal phenylalanine residue with 2-phenylethyl alcohol and by either replacing the tryptophan residue with an alanine, a norleucine and a phenylalanine residue, or introducing a "reduced peptide bond" in the tryptophan 30 region. Most of these compounds were able to reproduce only part of the response of cholecystokinin in stimulating amylase release from rat pancreatic acini, as was already observed for 2-phenylethyl ester analogues of CCK. These results point out the key role of tryptophan 30 in the biological response of cholecystokinin.

Amino Acid Sequence↗
PubMed1991

[Maternofetal infection with human parvovirus B19. Apropos of 2 cases].

Two cases of maternal-fetal human parvovirus B19 infection are reported. The first case involved a feto-placental anasarca occurring during the third trimester and complicated by in-utero death with expulsion of a fetus with multiple malformations. The second case involved meconial peritonitis during the second trimester with favourable outcome after cesarean section and resolution of the digestive syndrome. Proof of PV B19 infection was obtained by identifying M specific immunoglobulins and viral DNA. After a review of the clinical situations most often encountered and the particular features of these two cases, therapeutic attitudes are proposed for this infection of major gravity during pregnancy.

Adult↗
PubMed1989

Synthesis and biological activities of some cholecystokinin analogues substituted in position 29 by a beta-alanine.

Syntheses of analogues of the C-terminal heptapeptide of cholecystokinin are described. These analogues were obtained by replacing glycine 29 by a beta-alanine. The C-terminal phenylalanine amide was in some cases substituted by 2-phenylethyl alcohol and/or residues of the C-terminal tetrapeptide by their D-enantiomers. These compounds were tested for their action on stimulation of amylase release from rat pancreatic acini and for their ability to inhibit binding of labeled CCK to rat pancreatic acini and guinea pig brain membranes. Some of these derivatives behaved as CCK receptor antagonists.

Alanine↗
PubMed1989

Placental taurine and low birth weight infants.

In order to determine whether the decrease in taurine concentration in the placenta during pregnancy could affect fetal development, as has been observed in animals, we measured the concentration of taurine in placentas obtained after vaginal expulsion. 31 placentas from women with normal pregnancies of over 37 weeks who have given birth to infants of normal weight (3,200 +/- 310 g) were included in the study. In addition, 26 placentas of infants considered to be hypotrophic were also included (gestation over 37 weeks, birth weight: 2,260 +/- 230 g). The taurine was assayed using gaz-liquid chromatography. The concentration of taurine in the placenta was 2.80 +/- 0.56 mumol/g for the placentas of normal birth weight infants and 2.40 +/- 0.64 mumol/g for the placentas of hypotrophic infants (p less than 0.02). There is no significant correlation in normal and hypotrophic newborns between the gestation period, the weight and height at birth, the weight of the placenta, and the taurine concentration in the placenta. The taurine concentration in placentas of hypotrophic born infants is significantly reduced compared to the placentas from normal infants.

Female↗
PubMed1989

Taurine in developing brain, liver and muscle in infants.

In order to evaluate tissue taurine storage during pregnancy, we determined the taurine concentration of a skeletal muscle (abdominal wall), the brain (left parietal lobe), and the liver (right lobe) in 41 children aged 1-10 days, born after 24-41 weeks gestation. Samples were obtained during autopsy. Taurine dosage was carried out by gas chromatography. Muscle and liver taurine concentrations decreased with the duration of gestation. For a given duration of pregnancy, there was no correlation between birth weight and these three tissue concentrations. From these results, we estimate that the fetus accumulates 35-40 mumol/24 h of taurine during the last 3 months of gestation.

Anthropometry↗
PubMed1989

[Nosocomial infection at a neonatal care unit].

The incidence of nosocomial infections in a neonatal intensive care unit was evaluated to be 11.5% over a 2 year-survey period (1984-1985) in 451 artificially ventilated newborns. Staphylococcus, Enterobacter and Pseudomonas were the most frequently identified germs. Low birth weight, gestational age, mode of delivery and type of the initial pathology were not found to be responsible for the superinfection. The duration of hospitalization was 3 times longer and the cost per infant largely increased in cases with infection. Antibiotic treatment at admittance seemed to delay the onset of nosocomial infection by 8 to 12 days in this population.

Anti-Bacterial Agents↗
PubMed1989

[Predictive value of skull hypodensities in x-ray computed tomography in perinatal asphyxia in full-term newborn infants].

Prediction of risk of sequelae in 78 asphyxiated full-term newborns was evaluated during the 15 first days of life by clinical, electroencephalographic and cranial tomodensitometric (CT) data. The predictive value of CT hypodensity is poor (sensitivity: 87.7%; specificity: 63%), while its negative predictive value appears more interesting (97%). Combined evaluation of clinical, electroencephalographic and CT data allows the most accurate prognosis. These findings agree with other studies in the literature.

Asphyxia Neonatorum↗
PubMed1989

[Ultrasonic prenatal diagnosis of the Jarcho-Levin syndrome].

The Jarcho-Levin syndrome is an autosomal recessive disease characterized by spinal and rib malformations (spondylocostal dysplasia). The case reported concerns a fetus with a dorsal spine angulation noted at the 15th week of gestation. A more accurate ultrasound study performed at 20 weeks revealed shortness of the neck and thorax, irregular ribs and vertebrae and absence of other visceral abnormalities. The karyotype was normal. Therapeutic abortion proposed was finally accepted by both parents at 27 weeks. The diagnosis was confirmed by post mortem radiography. No parental consanguinity was noted.

Abortion, Therapeutic↗
PubMed1988

[Relations of iodination, hormonosynthesis and proteolytic cleavage in human thyroglobulin].

Normally iodinated thyroglobulin (Tg) contains low molecular weight hormone-rich peptides associated to the bulk of the molecule by disulfide bridges. It is shown, with the assistance of in vitro iodination experiments using different iodine concentrations and various incubation times, that the proteolytic cleavage giving rise to the 26 K hormonopeptide in human Tg is part of a coupling reaction rather than iodination. This cleavage may be a preliminary event related to a facilitation in the release of thyroid hormones.

Electrophoresis, Polyacrylamide Gel↗
PubMed1988

[Neonatal spinal cord injuries and magnetic resonance imaging].

Two cases of spinal cord injury involving the lower cervical region are reported. In both, the delivery of a breech presentation was difficult. Severe hypotonia, areflexia and autonomic nervous system disturbances suggested a spinal cord injury. The evidence, type, and location of the cord lesion were given by nuclear magnetic resonance (NMR).

Birth Injuries↗
PubMed1986

Characterization of a hormonogenic domain from human thyroglobulin.

A polypeptide domain of molecular mass near 22 kDa was purified from CNBr-digest of iodine poor human thyroglobulin (hTgb). This fragment represents the N-terminal part of the hTgb molecule and consequently contains the preferential hormonogenic tyrosine 'acceptor' of the protein. This fragment could correspond to the non-iodinated and unreduced form of the thyroxinyl-containing 26 kDa peptide previously purified from reduced and iodinated hTgb. This 22 kDa fragment is capable by itself, i.e. independently of the remaining hTgb molecule, of synthesizing thyroxine with a high efficiency after in vitro iodination. Its study should constitute a valuable way to identify at least one of the hormonogenic tyrosine 'donor' residues of hTgb.

Amino Acid Sequence↗