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Biomedical subjects

T Rebai

Publications and source records attributed to T Rebai.

At least 19 recordsLinked to original sources

Does cadmium pollution affect reproduction in the clam Ruditapes decussatus? A one-year case study.

The effect of cadmium (Cd) on the reproduction of Ruditapes decussatus was monitored over a period of 12 months, from June 2001 to June 2002. Two sites "Bordj d'Ungha" and "El Hofra" differing by their degree of cadmium contamination were chosen in the Gulf of Gabès area (Tunisia). Annual mean concentrations of Cd in the whole soft tissues of clams from the site El Hofra were more than 4 times higher than those from the site Bordj d'Ungha (reference site). The gametogenic cycle of the clam R. decussatus was also investigated by histological examination and monthly observations of gonadal sections in a population of clams from both sites. The results show that gametogenesis occurred from March to December in clams from both sites. Nevertheless, spawning and emission of gametes were synchronized in both sexes from only the clams of the reference site. Although this species is considered as gonochoristic, 6.6% of hermaphroditic cases were observed in clams from both sites in which gametes of both males and females were in ripe stage. Moreover, the period of ripening of sexual products led to an increase of condition index and to a decrease of Cd concentrations in the whole soft tissues of clams from both sites, hence reflecting the phenomenon of "biological dilution".

Animals↗

[Hemodynamics and microcirculation in a rat poisoned by scorpion venom]].

The clinic table of serious scorpionic envenimation is dominated by cardiovascular and pulmonary perturbations. The physiopathology of cardiac failure in man as well as at animal is again badly elucidated. The aim of our study has consisted in evaluating the hemodynamic variations of the Rat poisoned by the venom of the Buthus occitanus scorpion and to contribute through the analyse of plasmatic concentrations of catecholamines and by an histomorphometric study of muscular microcirculation to explain the mechanism of the hemodynamic perturbations and cardiac failure. 51 rats corresponding to 9 groups (witness and poisoned) have been used. The venom of the scorpion Buthus occitanus has been administrated at 850 micrograms/kg. Two groups have been served for hemodynamic study, three groups for the dosage of catecholamines and four groups for histomorphometric study. It has been observed a biphasic variation of arterial pressure and cardiac frequency after venom injection. Four minutes after envenimation, the plasmatic level of catecholamines was strongly higher in the poisoned according to the witness one. Histomorphometric study of muscular skeletal microcirculation has shown a decrease of relative vascular volume contemporary with the increase of plasmatic catecholamines concentration and the peak of arteriel pressure appeared just after envenimation. 10 and 20 minutes after envenimation, the relative vascular volume has significantly increased as well as that interstitium according to witness lot. These hemodynamic perturbations can be attributed to the important dump in catecholamines. This hyperadrenergy was contemporary with decrease of relative muscular vascular volume. This decrease would be explained by a constriction of vessels. On the other hand, the second increase of the vascular relative volume suggests the possibility of development of venous stasis at the muscular microcirculation. It would be induced by a cardiac failure and/or the effect of vasoplegic mediators being able to entail an interstitial oedema in the muscular skeletal that would led to increase the relative interstitial volume observed in this study.

Animals↗

[Thyrotoxicosis hepatitis: a case report].

Abnormal liver function in thyroid disorders may be secondary to thyrotoxicosis or to autoimmune injury to the liver. We report the case of a 36-year-old female who developed jaundice and pruritus with mild cholestasis and moderately elevated transaminase levels. The diagnosis of Graves' disease was made shortly thereafter. Laboratory findings were: alanine and aspartate aminotransferase 219 (IU/I (N: 9-50) and 102 IU/I (N: 10-15) respectively, alkaline phosphatase 336 IU/I (N: 40-135), bilirubin 24 micromol/I (N: 2-23), and gamma-glutamyl transpeptidase 232 IU/I (N: 9-43). Abdominal ultrasonography showed normal bile ducts; echocardiography ruled out heart failure; viral and autoimmune markers for hepatitis and cirrhosis were negative. Percutaneous liver biopsy showed moderate intrahepatic steatosis, anisokaryosis, lymphocyte infiltration in the portal areas, and Kupffer cell hyperplasia. Outcome was favorable after seven months of iodine therapy, confirming the diagnosis of thyrotoxicosis hepatitis.

Adult↗

[Propythiouracil and perchlorate effects on thyroid function in young and lactating mice].

We have studied the effects of propythiouracil (PTU) or perchlorate (CIO(4)(-)), given to the mothers' drink from the 15(th) day of pregnancy until the day of sacrifice, on thyroid function of suckling mice. Antihyroid drugs (PTU or CIO(4)(-)) provoked growth perturbations of young mice during studied ages from 6 to 18 days. A decrease of body weight was respectively as follows: 14 and 22% in 6 day-old mice; 16 and 23% in 10 day-old mice; 18 and 18% in 14 day-old mice; 19 and 11% in 18 day-old mice. We have noticed an hypertrophy of thyroid glands of pups and their mothers caused by an increase of pituitary TSH. Thyroid follicles presented the aspect of hypothyroid animals with an increase of follicular number and vascularisation. Structural modifications confirmed biochemical results. In fact thyroid iodine contents decreased strongly in young as follow: 40 and 43% in 6 day-old mice; 51 and 50% in 10 day-old mice; 66 and 84% in 14 day-old mice; 54 and 89% at 18 day-old mice and in their mothers (50, 37%; 59, 54%; 75, 65% and 85, 72%) respectively after PTU or CIO(4)(-) treatment. A decrease of iodine thyroid gland was accompanied by an important fall of free thyroid hormones levels (FT3 and FT4) in young and adult mice. A decrease of thyroid hormonemia could explain the pups' growth perturbations.

Aging↗

[Multifocal tubulopapillary tumors of the kidney. Morphologic features and prognosis. Three cases].

Tubulopapillary tumors of the kidney represent a particular group of renal tumors characterized by their less aggressive behavior. These tumors are distinguished from non papillary tumors by their morphologic, cytochemical and genotypic features. They correspond to a continuous spectrum of tumors ranging from papillary renal cell adenoma to papillary renal cell carcinoma. These TTPR show multifocal, bilateral development and chronic lesions of the kidney parenchyma in nearly all cases. The authors report three cases of multifocal TTPR, including one bilateral case. Based on analysis of these cases and a review of the literature, they discuss the histogenetic features and prognosis of TTPR.

Adenocarcinoma, Papillary↗

Expression of the endothelin-1 gene in the rat thyroid gland and changes in its peptide and mRNA levels in goiter formation and iodide-induced involution.

Endothelin-1 (ET-1) is a major vasoconstrictor peptide, first found in endothelial cells, and later in many other tissues, including the thyroid gland. We analysed the expression of the ET-1 gene in the rat thyroid gland and changes in ET-1 mRNA and peptide levels in goiter development and involution, two circumstances characterised by vascular changes. Thyroid hyperplasia was induced in adult Wistar rats by feeding a low iodine diet (LID) supplemented with 0.25% thiouracil for 10 days, and LID alone for 2 further days (H.12 group). Involution was induced by injecting 100 micrograms iodide and refeeding a normal diet during 6 h, 12 h, and 24 h (I.6h, I.12h, I.24h groups). Rats fed a normal iodine diet were used as controls. A specific 488 bp cDNA corresponding to the known sequence of pre-pro ET-1 was found by RT-PCR from RNA extracts in all thyroid experimental groups, as well as in lung and kidney which were used as positive controls. RP-HPLC analysis showed that ET-1 immunoreactivity eluted similarly as mature ET-1. During hyperplasia, ET-1 mRNA and peptide levels were increased 3.5- and 5-fold respectively. The relative volume of the vascular bed was more than doubled. During iodide-induced involution, the glandular ET-1 mRNA level remained elevated. The concentration of ET-1 peptide increased and was significantly greater at 12 h involution than in the H.12 group. At this time, the capillary reticulum reverted to individual capillaries and the vascular bed was significantly reduced. These data demonstrate that the ET-1 gene is expressed in the rat thyroid gland and that the ET-1 mRNA and peptide levels are increased during thyroid hyperplasia and remain elevated during a phase of rapid iodide-induced involution. These data suggest that changes in ET-1 production may play a role in control of thyroid gland trophic regulation and vascularity.

Animals↗

Involvement of T cell immunity in the transient thyroid inflammation induced by iodide in goitrous BALB/C and nude mice.

To evaluate the involvement of T cell immunity in the thyroiditis induced in goitrous mice by iodide administration, we analyzed the immunological changes happening in the thyroid glands and lymph nodes during goiter involution in balb/c and athymic nude mice of similar background. In both balb/c and nude mice, goiter involution was characterized by thyroid cell necrosis and inflammation. In balb/c mice, the inflammatory infiltrate was made of numerous Ia+ cells. Their number was unchanged during goiter development, but was significantly increased after 2 days of involution and remained high after 8 days. CD4+ and CD8+ T cells were also observed, some of which were clearly activated since they expressed the receptor for Interleukin-2 (IL-2R). The numbers of CD4+, CD8+ and IL-2R+ T cells were increased during goiter as compared to control mice, and they reached a maximum at day 1 of involution. In nude mice, unexpectedly, CD4+ and CD8+ T cells were also found in the thyroid. Their numbers, as well as the number of Ia+ cells, were significantly increased at the onset of involution, but they remained systematically lower than in the corresponding groups of balb/c mice. Iodide treatment of goitrous mice also induced modifications of the lymph nodes draining the thyroid: enlargement of the paracortical T zone, presence of germinal centers in cortical follicles, and increase of the density of IL-2R+ cells. Mesenteric lymph nodes taken as controls were unchanged. Thus, three observations suggest the involvement of T cell immunity in iodine-induced thyroid inflammation: 1. Infiltration of Ia+, CD4+, CD8+ and IL-2R+ cells. 2. Signs of stimulation in thyroid lymph nodes, 3. Significant differences between balb/c and nude mice, in which the inflammatory reaction is weaker.

Animals↗

[Perineo-scrotal liposarcoma. Apropos of 3 cases].

The authors report 3 rare cases of liposarcoma occurring in the perineal or paratesticular regions. They review literature data concerning this particular form of soft tissue sarcoma and emphasize on prognosis which depends mainly on its histopathological type.

Adolescent↗

[Perineo-scrotal liposarcoma. Apropos of 3 cases].

The authors report 3 rare cases of liposarcoma occurring in the perineal or paratesticular regions. They review literature data concerning this particular form of soft tissue sarcoma and emphasize on prognosis which depends mainly on its histo-pathologic type.

Adolescent↗

[Encrusted pyelo-ureteritis].

The authors report a case of right encrusted pyelo-ureteritis with no other sites, either in the bladder or on the other side. They discuss possible theories of pathogenesis of the encrusted plaques, and question how far corynebacterium, group D2, could be concerned in the genesis of such lesions.

Adult↗

[Pseudo-oligodendrogliomatous meningioma. Report of 2 cases and review of the literature].

We report two cases of oligodendroglioma-like meningioma revealed by symptoms of increased intracranial pressure, progressive hemiparesia and partial epileptic seizures. Brain CT-scan or scintigraphy and carotid arteriography were suggestive of a convexity meningioma. One patient had received radiation treatment for scalp tinea capitis 25 years previously. In spite of complete surgical removal, the tumor recurred in both cases respectively 17 years and 18 months later. The two patients were operated again, and one underwent a complementary radiotherapy. Pathologic diagnosis was particularly difficult in the first case where the pattern at conventional histologic technics was that of oligodendroglioma. On the occasion of recurrence, immuno-histochemistry and ultrastructural studies were performed. The tumor was positive for epithelial membrane antigen (E.M.A) and cytokeratin, but was negative for glial fibrillary acidic (G.F.A.) protein, S 100 protein (S 100), neuron-specific enolase (N.S.E.), vimentin, anti-LEU-7 (N.H.K.1), and neurofilaments (N.F.). Electron microscopy showed closely adjacent cells with tonofilaments and numerous desmosomes. These findings permitted to establish the diagnosis of oligodendroglioma-like meningioma instead of oligodendroglioma. In the second case, the histologic pattern was also reminiscent of oligodendroglioma, but presence of few cellular whorls in some part of the tumor permitted the correct diagnosis. The pathogenesis of this atypical form of meningioma, its tendency for recurrence, and usefulness of radiotherapy are discussed and literature is reviewed.

Adult↗

[Xanthogranulomatous pyelonephritis. Apropos of 42 cases].

The authors report their experience of forty-two cases of xanthogranulomatous pyelonephritis. They point out the various difficulties of preoperative identification of such diseases by the imaging modalities. They also discuss the main pathogenic hypotheses proposed in the literature.

Adolescent↗

[Gougerot-Sjögren syndrome associated with dysthyroidism].

The occurrence of Gougerot-Sjögren syndrome in a context of dysthyroidism is not a chance happening, as is reflected by the 37% rate of incidence. Routine labial biopsy, carried out in 59 cases of primary hypothyroidism due to atrophic thyroiditis, 20 of Basedow's disease and 4 of Hashimoto thyroiditis identified Gougerot-Sjögren syndrome (3-4 Chisholm grade) in 3 of the 59 cases of hypothyroidism i.e. in 5 percent, and in one Basedow case out of 20, i.e. 5 percent. Using Kaplan's criteria, the incidence of Gougerot-Sjögren syndrome rises to 22 percent in hypothyroidism and 30 percent in Basedow's disease. Consequently, the incidence of Gougerot-Sjögren syndrome is higher in Basedow disease than in primary hypothyroidism. Gougerot-Sjögren syndrome is seen particularly in dysthyroidism involving manifest and all-round clinical signs. This association does not seem to result from one disease being caused by the other, but the outcome of the onset of entities to which a genetically determined context predisposes the subject, as is shown by the prevalence of HLA DRW3 and HLA B8 groupings in Gougerot-Sjögren syndrome, in primary hypothyroidism, in Basedow's disease and in Hashimoto's thyroiditis.

Adult↗

[Xanthogranulomatous pyelonephritis in children. Apropos of 8 cases].

Eight pediatric cases of the diffuse form of xanthogranulomatous pyelonephritis are reported. These patients were selected among 17 with destruction of one kidney. Clinical symptoms were suggestive of a tumor in some instances. However, an infectious etiology was strongly suggested by the presence of a renal lithiasis in seven cases (including five staghorn stones) and of a urinary tract infection in six cases (usually caused by a Proteus). Nephrectomy was performed in every case.

Child↗

Focal myelin thickenings in a peripheral neuropathy associated with IgM monoclonal gammopathy.

Nerve biopsy in peripheral neuropathies associated with an IgM monoclonal gammopathy may occasionally display focal myelin thickenings. In a patient with such an IgM neuropathy, in whom an anti-myelin-associated glycoprotein (MAG) antibody activity was present in the serum, single-fiber preparations revealed 34% of internodes bearing myelin swellings. The morphometric, morphological and ultrastructural findings were reminiscent but not identical to those of the hereditary tomaculous neuropathy with liability to pressure palsies. Atypical features for tomacula included lack of spiralization of the redundant loops of myelin around the axons and their predominant external situation with regard to the myelin sheath. The frequent colocalization of myelin thickenings and the widening of myelin lamellae typical of IgM neuropathies, are highly suggestive of some pathogenetic link between the two abnormalities. The redundant loops of myelin in IgM neuropathies possibly result from a defect in the axon-myelin adhesion secondary to the binding of IgM on an epitope of MAG directly involved in cell-cell adhesion.

Aged↗