[Study of epidemiological clinical and pathological characteristics of gastric adenocarcinoma in a Moroccan population]. / Étude des caractéristiques épidémiologiques cliniques et anatomopathologiques de l'adénocarcinome gastrique chez une population Marocaine.

Stomach cancer is essentially represented by gastric adenocarcinomas. It remains one of the world's top ten causes of death with a poor prognosis. The aim of our work is to describe the epidemiological characteristics of gastric adenocarcinoma through a retrospective, observational study over a period of one year. One hundred and twenty one cases were sent to the Pathology Laboratory of the IPM-Casablanca, 98 were selected for this study. There was a male predominance. Patients aged over 50 years represented the predominant age group (62%) (P-value=0.03). The average tumor size was 5,17±2,16cm, and most patients were diagnosed in the advanced TNM stage with a rate of 72.44%. In the absence of specific symptoms, gastric adenocarcinoma is a cancer of elderly, frequently diagnosed at a late stage, minimizing the chances of any curable treatment. The adoption of a screening policy in our area would probably be beneficial. Indeed, the benefit of annual screening at least among people aged over 50 years should be assessed.

[Helicobacter pylori infection in 755 patients with digestive complaints: Pasteur Institute, Morocco, 1998-2007]. / L'infection a Helicobacter pylori chez 755 patients présentant des symptômes digestifs: Institut Pasteur du Maroc, 1998-2007.

We determined the prevalence of Helicobacter pylori infection in 755 patients with digestive complaints identified from laboratory records at the Pasteur Institute, Morocco from 1998 to 2007. Epidemiological factors and gastrointestinal conditions associated with this infection were also studied. All patients underwent endoscopy and diagnosis was by histology examination. The prevalence of H. pylori infection was 69%. The difference in prevalence between the age group 40-50 years and other age groups was statistically significant; gender had no significant association. H. pylori infection was found in 92% of chronic gastritis cases. The prevalence of H. pylori was significantly higher in the antrum (73%) than in the corpus (21%) and the pylorus (6%).

Study of the RET gene and his implication in thyroid cancer: Morocco case family.

BACKGROUND: Multiple endocrine neoplasia type 2A (MEN 2A) is an autosomal dominant inherited cancer syndrome that affects multiple tissues derived from the neural crest. Inheritance of MTC is related to the presence of specific mutations in the RET proto-oncogene. Almost all mutations in MEN 2A involve one of the cysteines in the extracellular domain of the RET receptor. AIMS: The objective of the present study was the biochemical and molecular characterization of the first Moroccan clinically established MEN 2A patient and at-risk family members. SETTINGS AND DESIGN: This is a study on a family presented with MTC referred to our institute in 2004. MATERIALS AND METHODS: Peripheral blood leukocyte DNA samples were isolated and amplified by polymerase chain reaction followed by restriction enzyme analysis and DNA sequencing. RESULTS: We identified a heterozygous germ line missense mutation at codon 634 of exon 11 in the RET gene that causes a cysteine to arginine amino acid substitution in the DNA of the proband; this mutation was not found in the DNA of the parents or relatives. CONCLUSIONS: The detection of mutated MEN 2A gene carriers enables us to differentiate high-risk members from those who bear the wild-type gene. Occasionally, application of RET proto-oncogene testing may lead to the detection of unexpected de novo mutation that could be transmitted to children.

A hypothesis regarding possible interactions between the pressure-induced disorders in dopaminergic and amino-acidergic transmission.

When human divers or experimental animals are exposed to high pressure they develop the high pressure neurological syndrome (HPNS). The main symptoms include electroencephalographic changes and behavioral disturbances such as tremor, myoclonia, and hyperlocomotor activity. Recently, pressure-induced disorders in dopaminergic and amino-acidergic neurotransmission have been reported. In the present theoretical study, we review in vitro and in vivo neurochemical, electrophysiological, and pharmacobehavioral evidence concerning alterations in dopaminergic, glutamatergic, and GABAergic transmission occurring at high pressure, and their possible relationship to the symptoms of HPNS. Moreover, we also examine data concerning interactions, at normal pressure, between dopaminergic, glutamatergic, and GABAergic transmission that we suggest they could apply equally under high pressure between the pressure-induced disorders in dopaminergic and amino-acidergic transmission.

Pressure-induced disorders in neurotransmission and spontaneous behavior in rats: an animal model of psychosis.

Disorders in neurotransmission and spontaneous behavior in rats exposed to a high pressure helium-oxygen mixture that shows interesting parallels with the dopaminergic hypothesis of schizophrenia at both the biochemical and the therapeutic responding levels are reviewed. Furthermore, as human subjects exposed to a very high pressure have shown psychotic episodes, we conclude that the pressure-induced disorders in neurotransmission and spontaneous behavior in rats could constitute a valid animal model of schizophreniform psychosis and a useful tool for both the investigation of the biological mechanisms underlying schizophrenia and the development of new antipsychotic drugs.

Pressure reversed extracellular striatal dopamine decrease produced by D1 receptor agonist SKF 38393, and D2 receptor agonist LY 171555, but failed to change the effect of the activation of both D1 and D2 receptors.

When human divers or experimental animals are exposed to high pressure, they develop the high-pressure neurological syndrome which is characterized by electroencephalographic changes, and behavioral disturbances. Recently, neurochemical disorders such as a pressure-induced increase in dopamine release have been demonstrated. In the present study, pharmacological experiments, using dopamine receptor agonists such as D1 receptor agonist SKF 38393, D2 receptor agonist LY 171555, and D1/D2 receptor agonist apomorphine, were performed to investigate dopamine receptor function at the neurochemical level. Only apomorphine and mixed SKF 38393 + LY 171555 prevented the pressure-induced increase in dopamine release while SKF 38393 or LY 171555 administered alone failed to do so. The results suggest that the D1-D2 link would be reduced under high pressure because of an abnormal function of D1 receptors which would allow high-affinity D2 states for dopamine. If so, such a preponderance of high-affinity states in D2 postsynaptic receptors could be associated with hyperbaric hyperlocomotor activity. Elsewhere, results also suggested that the pressure-induced disorders in dopamine receptor function could be involved in the pressure-induced elevation in dopamine release.

Pressure increases de novo synthesized striatal dopamine release in free-moving rats.

When human divers or experimental animals are exposed to high pressure, they develop brain and biobehavioural disorders. Since it has been demonstrated that pressure exposure increased striatal DA release, the present experiments were intended to investigate whether it resulted from a release in de novo synthesized DA or from a release of DA stores. Free-moving rats implanted with multi-fibre carbon electrodes sensitive to DA were pretreated with reserpine, a depleter of catecholamine stores, and compressed to 8 MPa. Results show that pretreatment with reserpine had no ability to block the pressure-induced DA release. In the light of previous relevant studies, we suggested that the elevation of DA release under high pressure would be the consequence of a release in de novo synthesized DA.

D1 receptors modulate striatal dopamine release induced by the stimulation of both D1 and D2 receptors: in vivo voltammetric data revisited.

Here we re-examine previous data that demonstrated lasting effects of the selective D1 receptor agonist SKF 38393, the selective D2 receptor agonist LY 171555, and of mixed SKF 39383 + LY 171555 upon striatal DA release. We demonstrate that the administration of mixed SKF 38393 + LY 171555 and of SKF 38393 administered alone induced similar time-course effects upon striatal DA release that showed significant parallel developments. We discuss these data in the light of the current literature and we suggest that D1 receptors could play a modulating role on the striatal DA activity and the release of DA in the caudate-putamen.

Lasting effects of dopamine receptor agonists upon striatal dopamine release in free-moving rats: an in vivo voltammetric study.

It is now well known that dopamine (DA) receptors agonists can reduce striatal DA release. These compounds are generally thought to produce short-term effects. However, in a recent in vivo study we have reported that the D1/D2 receptor agonist apomorphine might induce decrements in striatal DA release that lasted several hours. In order to establish whether the effect of apomorphine was idiosyncratic or extended to other DA receptor agonists, we have investigated the effects of the selective D1 receptor agonist SKF 38393 and of the selective D2 receptor agonist LY 171555 upon striatal DA release using differential pulse voltammetry and multi-fibre carbon electrodes selective for DA. Results support that these DA receptor agonists can reduce DA release for several hours. The effects of SKF 38393 and of LY 171555 would be DA receptor-mediated since they can be blocked by the selective D1 receptor antagonist SCH 23390 and the selective D2 receptor antagonist sulpiride respectively. These findings are discussed at the light of current literature including methodological and biological data.

Relationship between emotional status and spontaneous behavior in rats exposed to high pressure.

When humans and experimental animals are exposed to increased environmental pressure, they develop the high pressure neurological syndrome. In the present study, we have investigated the relationship between the emotional status and the development of pressure-induced behavioral disorders, such as locomotor and motor activity (LMA) and myoclonia, in two genetically selected lines of rats (Roman low-(RLA/verh) and high-(RLA/verh) avoidance), which differ drastically in their level of emotionality. RLA/verh rats presented a greater level of LMA than RHA/Verh rats; RLA/Verh rats also showed myoclonia while RHA/Verh rats did not. These results are discussed in the light of recent experiments in rats exposed to stressful situations or pressure environment. It is concluded that the use of both RLA/Verh and RHA/Verh rats would be of particular interest to better understand the neurochemical and neurological processes underlying the development of LMA and myoclonia in rats exposed to high pressure.

Role of glucagon in the control of heat production in ducklings.

Glucagon is known to be a central modulator of neural activity and a peripheral thermogenic effect. The purpose of this study was to better understand the role of glucagon in the control of heat production, shivering and particularly as a mediator of nonshivering thermogenesis (NST) in ducklings. In order to study the mechanism of NST, an intracerebroventricular (i.c.v.) injection of glucagon (10(-7) M) in to thermoneutral (TN), chronically glucagon treated (GT) and cold acclimatized (CA) ducklings exposed to acute cold (4 degrees C) or a thermoneutrality (25 degrees C), was performed. At 25 degrees C ambient temperature (Ta), the metabolic rate (MR) remained unchanged after glucagon injection. At 4 degrees C Ta i.c.v. glucagon injection, no significant change in MR was observed in GT and CA ducklings during 160 min of cold exposure, whereas there was 63% decrease in MR in (TN) ducklings (5.02 +/- 0.1 2 vs 7.91 +/- 0.1 4 W/kg(-1) p < 0.05). Shivering activity was completely suppressed in TN and GT ducklings after glucagon administration. The NST was estimated to be 3.26 W/kg. This findings suggest that glucagon administered into the brain has no thermogenic effect but could be involved in the central control of somatic motricity, and here we demonstrated for the first time, of our knowledge, that central glucagon have a role in the development of nonshivering thermogenesis during prolonged cold via an inhibition of shivering in birds.

Effects of intracerebroventricular injections of des-His1 (Glu9) glucagon amide on the regulatory thermogenesis in muscovy ducklings.

Recent investigations have demonstrated a modulatory action of glucagon on shivering via the central nervous system in ducklings. Such an action could be mediated by glucagon receptors that have been recently detected in several brain areas involved in the central control of the involuntary motricity in this avian species. The present study using des-His1 (Glu9) glucagon amide, was performed to investigate the central mechanisms of glucagon on shivering. This glucagon analog was found to be an antagonist of glucagon devoid of adenylate cyclase activity (GR2) by triggering the breakdown of inositol phosphate (GR1) in mammals hepatocytes. The intracerebroventricular administration of des-His1 (Glu9) glucagon amide or glucagon induced a marked inhibition of shivering in ducklings exposed to cold. It seems likely that GR1 receptors contribute to decreased shivering in ducklings exposed to cold. Central glucagon or des-His1 (Glu9) glucagon amide were devoid of thermogenic effect at thermoneutrality.

Responsiveness of plasma catecholamines to intracerebroventricular injection of glucagon in Muscovy ducklings.

Recent investigations have demonstrated a modulatory action of glucagon on shivering via the central nervous system in ducklings. The aim of this study was to investigate the effects of intracerebroventricular injection (i.c.v.) of glucagon on metabolic rates (MR) and plasma catecholamines in control ducklings (TN) and in ducklings exhibiting nonshivering thermogenesis after chronic glucagon treatment: (GT). At thermoneutrality (25 degrees C, Ta), i.c.v. injection of glucagon had no thermogenic effects in TN and GT ducklings. At cold (+4 degrees C, Ta), i.c.v. glucagon injection elicited a concomitant decrease of plasma norepinephrine (NE) and MR in TN ducklings, whereas in GT ducklings, the plasma catecholamines and the MR remained unchanged. These results indicate that glucagon treatment rendered the catecholaminergic system of GT ducklings insensitive to cold or i.c.v. glucagon injection.