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Biomedical subjects

J Rey

Publications and source records attributed to J Rey.

At least 127 records · Page 7Linked to original sources
PubMed1985

[Decrease of the cytotoxicity of gliadin fractions in the development of celiac disease. Organotypic culture study].

Observation up to adulthood of children with coeliac disease given again a normal diet had shown a clinical as well as histologic reduction in their sensitivity to gluten. From this fact a retrospective study was undertaken to appreciate whether this decreased sensitivity was also observed in vitro in a model of organotypic culture of intestinal mucosa obtained by biopsy, in the presence of gliadin toxic peptides. Twelve children had 2 cultures with a several year interval under normal diet. In 10 of them a decreased cytotoxic effect was observed. However, the explanation of this decrease remains difficult. It seems related neither to the age of the children, nor with the status of the mucosa at the time of in vitro testing, or to the duration of the gluten-containing diet. This study finally confirms that it is impossible to use organotypic cultures as an in vitro test for the diagnosis of coeliac disease.

Celiac Disease↗
PubMed1984

Hudson memorial lecture. Neonatal management of organic acidurias. Clinical update.

Therapeutic guidelines have been obtained from a retrospective review of 41 patients affected with organic acidaemias, 16 patients with neonatal maple syrup urine disease (MSUD), 11 methylmalonic acidaemia, (MMA) seven propionic acidaemias (PA) and seven isovaleric acidaemias (IVA), and by comparing this personal series with similar reported cases. The emergency treatment of these organic acidurias in the neonate has to main goals: toxin removal and anabolism. Anabolism is always promoted by early diet therapy. The best method of toxin removal depends on the nature of the defect; peritoneal dialysis with exchange transfusions or multiple or prolonged exchange transfusions in MSUD and in PA, diuresis and exchange transfusions in MMA and glycine supplementation in IVA. Vitamin supplementation (thiamine 20 mg, biotin 10 mg, B12 2 mg and riboflavin 100 mg) should be tried in all cases although the neonatal forms of these defects are very rarely vitamin responsive. Additional treatments such as carnitine or insulin may prove to be useful.

Acids↗
PubMed1984

Single unit activity in the nucleus of the basal optic root (nBOR) during optokinetic, vestibular and visuo-vestibular stimulations in the alert pigeon (Columbia livia).

Extracellular recordings were performed in the nucleus of the basal optic root (nBOR) of alert pigeons during optokinetic nystagmus (OKN), vestibulo-ocular reflex (VOR) and combined visuo-vestibular stimulation. Cell identification was assessed either by histological control or by electrophysiological testing (antidromic response to vestibulo-cerebellar or oculomotor complex stimulation). 1) OKN was induced in 8 directions by a binocular stimulation. During the fast phase of OKN, optokinetic after nystagmus (OKAN) or reversed OKAN, most cells showed an inhibition which varied in magnitude independent of the direction of stimulation. A few cells however showed a phasic discharge for some OKN directions. 2) During the slow phase of OKN induced by a binocular stimulation, cells displayed either a tonic activation or a more or less strong inhibition according to the direction of the OKN. Cells were classified in 4 groups, according to their degree of directional specificity. The best OKN direction (slow phase) for maximal cell activation was upwards and naso-upwards, and next to best, naso-temporal and downwards. Maximal cell inhibition occurred during downward, and for some cells during upward, directions. 3) During OKN induced by stimulating the eye contralateral to the recorded nBOR, cell responses resembled those obtained during binocular stimulation, but, during ipsilaterally induced OKN, the cells lost their directional specificity. As a result of binocular integration, neuronal activation seems to originate from contralateral input whereas cell inhibition would mainly come from ipsilateral input. 4) During sinusoidal optokinetic stimulation induced in the temporo downward-naso upward axis, cells showed a more or less marked modulation (according to their directional selectivity) that was closely in phase with the stimulation velocity, and therefore probably with retinal slip. 5) nBOR cells appeared generally unaffected during both the slow phase and the fast phase of the VOR. However, some cells showed a slight but irregular modulation which might imply a weak vestibular input. During visuo-vestibular stimulation, the response resembled that obtained with sinusoidal optokinetic stimulation but the fast phase inhibition was often strengthened in the downwards direction (fast phase).

Animals↗
PubMed1983

Optokinetic nystagmus in the pigeon (Columba livia). II. Role of the pretectal nucleus of the accessory optic system (AOS).

In birds, the accessory optic system (AOS) includes two nuclei: the nucleus ectomamillaris (nEM) and the pretectal nucleus superficialis synencephali (nSS). The role of the nSS in the production of a horizontal optokinetic nystagmus (OKN) was studied in the pigeon, by comparing the OKN before and after a unilateral lesion of this nucleus. The lesions were performed either by electrolysis or by local application of kainic acid (KA); the KA lesions gave more stable modifications of the OKN than the electrolytic lesions. A quantitative analysis of the slow-phase velocity (V) of the OKN was carried out on the animals receiving KA lesions. Lesion of the nSS provokes the almost total disappearance of the OKN for stimulation of the contralateral eye in the temporo-nasal direction, and a reduction of the OKN for stimulation in the naso-temporal direction. Thus, the nSS is essential for the production of the OKN in the temporo-nasal direction, but it also participates in the production of the OKN in the naso-temporal direction (slow-phase direction). The same lesion produces a large increase of the OKN (V) when the ipsilateral eye is stimulated in the temporo-nasal direction, and a smaller increase following stimulation in the naso-temporal direction. These increases suggest some kind of inhibitory (or disfacilitatory) interactions between the nSS (or the associated system) on one side, and the contralateral optokinetic centers. The lesion of one nSS does not provoke a deficit when the stimulation is binocular. This result probably reflects the combined effect of both monocular inputs. After a pretectal KA injection, a spontaneous nystagmus of the contralateral eye, in the naso-temporal direction, can be seen for several hours. The mechanism is still unknown, but it might be related to a reverse optokinetic after nystagmus (R-OKAN). The anatomical and physiological data so far available consistently support the hypothesis of a functional equivalence between the nSS in birds and the nucleus of the optic tract in mammals.

Animals↗
PubMed1983

Optokinetic nystagmus in the pigeon (Columba livia). III. Role of the nucleus ectomamillaris (nEM): interactions in the accessory optic system (AOS).

The accessory optic system (AOS) in birds is composed of two structures: the nucleus Superficialis Synencephali (nSS), essential for the production of an optokinetic nystagmus (OKN) in the temporo-nasal direction (slow phase) for the eye contralateral to the nucleus, and the nucleus Ectomamillaris (nEM), or nucleus of the basal optic root (nBOR). The objectives of the present work were: (1) to study the importance of the nEM for the horizontal OKN, (2) to study the interactions between the nSS and the nEM. Experiments were realized by combining different kinds of lesion. (1) Results show that the nEM is essential for the production of an OKN in the naso-temporal direction (direction of the slow-phase), but it also participates in the temporo-nasal response. (2) After bilateral lesion of the nEM or the nSS, only a residual nystagmic response remains. (3) Synergic effects exist between (I) the homolateral nEM and nSS, or between the systems related to them; we call this relation "homolateral synergy", (II) a nEM and the contralateral nSS (or systems related to these nuclei). The synergic effect exerted by one nEM upon the contralateral nSS appears to be stronger than the reciprocal effect. (4) The effects obtained after combined lesions, either homolateral (nEM and nSS on the same side) or heterolateral (nEM and nSS on opposite sides) confirm the previous results and show that heterolateral interactions are stronger than homolateral interactions. (5) For all the lesions studied, the results obtained from binocular stimulation are compatible with a model of convergence of monocular inputs. The role of the nuclei of the AOS in birds is discussed in terms of existing anatomical and physiological data.

Animals↗
PubMed1983

Portacaval shunt in patients with familial hypercholesterolemia.

Portacaval shunt was performed in ten patients with homozygous and two with heterozygous familial hypercholesterolemia (FH). Total serum cholesterol was lowered by 20% to 55.4% during follow-up periods of 14 months to almost 9 years, with commensurate decreases in LDL cholesterol. The effect on HDL cholesterol and triglyceride levels was variable. Tendinocutaneous xanthomas diminished or disappeared. Growth and development in children proceeded or accelerated. There was no detectable emotional or intellectual deterioration. Hepatic failure did not occur, although blood ammonia concentrations and serum alkaline phosphatase levels increased relative to preoperative values. Cardiac symptoms were often improved, but evidence of reversal of cardiovascular lesions was inconclusive. Three patients with pre-existing heart disease died of cardiac complications after 4 months, 18 1/2 months, and 30 months. Portacaval shunt has been effective therapy for patients with FH who were refractory or intolerant to medical treatment; it should be performed before the development of irreversible cardiovascular damage.

Adolescent↗
PubMed1983

Intestinal malignant lymphoma in a child with familial celiac disease.

A case of intestinal malignant lymphoma occurring in a 10-year-old North African girl with celiac disease is reported. Celiac disease was diagnosed at age 4. A gluten-free diet was started and was maintained for the next 6 years. Seven months after the patient returned to a normal diet, clinical symptoms and subtotal villous atrophy relapsed. Within the next month an abdominal malignant lymphoma was diagnosed. After chemotherapy the tumor disappeared but recurred 6 months later, involving the colon and the liver. Death occurred shortly thereafter. A brother, two years older, also with proven celiac disease, is presently on a strict gluten-free diet. Both children shared the same histocompatibility antigens (HLA A2-B17/A29-B12, identity at the D locus). Whether or not relapse of celiac disease played a role in the appearance of the tumor remains highly speculative; however, the case of our patient suggests that familial involvement and, in some instances, ethnic origin may constitute risk factors predisposing to malignancy.

Celiac Disease↗
PubMed1983

[Ileo-cecal tuberculosis. A difficult diagnosis].

An ileocaecal tuberculosis suspected in an Algerian girl was confirmed only by operative findings and by the presence of caseum at histological examination. Mycobacterium tuberculosis could not be cultured from the lesions. Diagnostic problems between tuberculous enteritis and Crohn's disease are discussed.

Adolescent↗
PubMed1982

[Single unit activity in the nucleus ectomamillaris (nem) during optokinetic nystagmus, in the pigeon].

Extra-cellular recordings of single units were obtained in the nucleus ectomamillaris (nEM) in waking Pigeons, during optokinetic nystagmus (OKN). OKN was obtained for 8 directions of stimulation (horizontal, vertical and oblique) in monocular and binocular vision. For half of the units the responses were synchronized, showing activation during the slow-phase and inhibition during the fast phase of the OKN. This response pattern was more common for the horizontal OKN, both in the Nasal to Temporal (N-T) and in the Temporal-to-Nasal (T-N) directions. With contralateral stimulations, most cells showed directional selective responses for upwards and backwards directions, the activity being inhibited for the other directions. Some units showed a less marked directional selectivity or were unaffected by the stimulations. Ipsilateral stimulations provoked no directional selectivity, but rather a reduction of the firing level. With binocular stimulation, responses were very close to those obtained with contralateral stimulation, with an increase of the directional selectivity. The nEM seems to be involved in the control of OKN, specially for the N-T and upwards directions, and less significantly for the T-N direction.

Animals↗
PubMed1982

The toxic fraction of gliadin digests in coeliac disease. Isolation by chromatography on Biogel P-10.

Improvement in the fractionation of gliadin digests and in the isolation of toxic fractions was achieved using chromatography on Biogel P-10. Fraction V, one of the 11 fractions eluted from a peptic-tryptic digest of crude gliadin extracted from Cappelle wheat, significantly affected coeliac jejunal mucosa in organ culture. BV, gamma V, omega V, the corresponding fractions V from beta-, gamma- and omega-gliadins, displayed similar toxic effects. Fraction VI containing peptides with a lower molecular mass did not show any significant cytotoxic activity and, moreover, inhibited the toxicity of fraction V. Analysis of the toxic fractions V showed that they contained peptides of 7-8,000 molecular mass, rich in proline and glutamine and poor in aromatic amino acids and carbohydrates. Among the various fractions, V, beta V from beta-gliadin appeared the less heterogeneous.

Amino Acids↗
PubMed1982

Fat absorption in low birthweight infants.

Studies on the incomplete fat absorption in newborns, particularly preterm ones, are reviewed. In the first week term breastfed newborns have a fat absorption coefficient of 91%. Lyophilization or pasteurigation reduces this figure in term as well as in preterm newborns. Excess Ca++ lowers fat absorption. So far, there is no evidence of immaturity of intracellular fat transport through the enterocyte. In the newborn low pancreatic lipase activity and low intraluminal bile salt concentrations appear to limit fat absorption. The most effective method to improve fat absorption in preterm babies seems to substitute part of the milk fat by medium-chain triglycerides.

Animals↗