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Biomedical subjects

A Alaoui

Publications and source records attributed to A Alaoui.

At least 19 recordsLinked to original sources

Immunocytochemical detection of cholecystokinin and corticotrophin-releasing hormone neuropeptides in the hypothalamic paraventricular nucleus of the jerboa (Jaculus orientalis): modulation by immobilisation stress.

The hypothalamic response to an environmental stress implicates the corticotrophin-releasing hormone (CRH) neuroendocrine system of the hypothalamic parvicellular paraventricular nucleus (PVN) in addition to other neuropeptides coexpressed within CRH neurones and controlling the hypothalamo-pituitary-adrenal (HPA) axis activity as well. Such neuropeptides are vasopressin, neurotensin and cholecystokinin (CCK). It has previously been demonstrated that the majority of the CRH neuronal population coexpresses CCK after a peripheral stress in rats. In the present study, we explored such neuroendocrine plasticity in the jerboa in captivity as another animal model. In particular, we studied CCK and CRH expression within the hypothalamic PVN by immunocytochemistry in control versus acute immobilisation stress-submitted jerboas. The results show that CCK- and CRH-immunoreactive neuronal systems are located in the hypothalamic parvicellular PVN. The number of CCK-immunoreactive neurones within the PVN was significantly increased (138% increase) in stressed animals compared to controls. Similarly, the number of CRH-containing neurones was higher in stressed jerboas (128%) compared to controls. These results suggest that the neurogenic stress caused by immobilisation stimulates CCK as well as CRH expression in jerboas, which correlates well with previous data obtained in rats using other stressors. The data obtained also suggest that, in addition to CRH, CCK is another neuropeptide involved in the response to stress in jerboa, acting by controlling HPA axis activity. Because CCK is involved in the phenotypical plasticity of CRH-containing neurones in response to an environmental stress, we also explored their coexpression by double immunocytochemistry within the PVN and the median eminence (i.e. the site of CRH and CCK corelease in the rat) following jerboa immobilisation. The results show that CCK is not coexpressed within CRH neurones in either control or stressed jerboa, suggesting differences between jerboas and rats in the neuroendocrine regulatory mechanisms of the stress response involving CRH and CCK. The adaptative physiological mechanisms to environmental conditions might vary from one mammal species to another.

Animals↗

Biochemical characterisation and immunohistochemical localisation of the secretogranin II-derived peptide EM66 in the hypothalamus of the jerboa (Jaculus orientalis): modulation by food deprivation.

The neuroendocrine protein secretogranin II is the precursor of several neuropeptides, including secretoneurin and a novel 66-amino acid peptide, EM66, the sequence of which has been highly conserved across the vertebrae phylum. The presence of EM66 has been detected in the adult and fetal human adrenal gland, as well as the rat pituitary and adrenal glands. The present study aimed to explore a possible neuroendocrine role of EM66 by analysing its occurrence and distribution within the jerboa hypothalamus, and its potential implication in the control of feeding behaviour. High-performance liquid chromatography analysis of jerboa hypothalamic extracts combined with a radioimmunoassay of EM66 revealed a single peak of immunoreactive material exhibiting the same retention time as recombinant EM66. Immunocytochemical labelling showed that EM66-producing neurones are widely distributed in several hypothalamic regions, including the preoptic area, the suprachiasmatic, supraoptic, parvocellular paraventricular and arcuate nuclei, and the lateral hypothalamus. Food deprivation for 5 days induced a significant increase in the number of EM66-containing neurones within the arcuate nucleus (105% increase) and the parvocellular aspect of the paraventricular nucleus (115% increase), suggesting that EM66 could be involved in the control of feeding behaviour and/or the response to stress associated with fasting. Altogether, these data reveal the physiological plasticity of the EM66 system in the hypothalamus and implicate this novel peptide in the regulation of neuroendocrine functions.

Amino Acid Sequence↗

[Lateral dislocation of the elbow: pathophysiological and therapeutic analysis].

Lateral dislocation of the elbow is exceptional, and its pure form even more so. We report a case of lateral dislocation of the elbow observed in a 65-year-old woman following a fall on the medial aspect of the elbow in the flexion position. Reduction could not be achieved because of the anconeus muscle interposition. Analysis of the mechanism involved and the displacements observed enabled to propose a reduction manoeuvre using gentle traction on the elbow with extension and progressive supination of the forearm, pushing the olecranon backward then pulling it medialy. This enabled avoiding incarceration of the nerve bundle or capsulo-ligamentary structures.

Accidental Falls↗

[Trachoma in Ouarzazate: clinical and biological study].

A conjunctival sample for the research of chlamydiae was made on 87 persons (44 patients and 43 control persons). Clinical examination shows that 27 patients (61.4%) were suffering from a Trachoma. Direct examination with IF was positive for 9 patients (20.4%) and negative for all control people (P 0.001). A link between the positivity of the direct examination and the serology was found for 9 patients. The antibody anti-chlamydiae rate was higher or equal to 1/256 for 12 patients (44.4%).

Adolescent↗

[A case of an adult triatrial heart, associated with partial abnormal venous return from the left lung].

The authors underline the value of echocardiography in the diagnosis and postoperative management of a case of cor triatrium. The patient was a 22 year old male who presented with dyspnoea of effort (stage III of the NYHA classification) and clinical signs of an infundibulo-pulmonary syndrome with tricuspid regurgitation. Chest X-ray revealed cardiomegaly (CTI = 61%) and filling-in of the aorto-pulmonary window. The electrocardiogram showed left atrial and right ventricular hypertrophy. The echocardiogram, the key to diagnosis, showed an abnormal echogenic structure within the left atrium. Cardiac catheterisation demonstrated pulmonary hypertension and a difference of pressure between the two lungs. The membrane dividing the left atrium and partial anomalous pulmonary venous drainage from the left lung into the superior vena cava were visualised on late stage pulmonary angiography. Surgical excision of the membrane in the left atrium and ligation of the anomalous venous drainage provided a radical cure to all these malformations.

Adult↗