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Biomedical subjects

M Wassef

Publications and source records attributed to M Wassef.

At least 145 records · Page 8Linked to original sources

Alpha-chain disease without qualitative serum IgA abnormality. Report of two cases, including a "nonsecretory" form.

Two cases of alpha-chain disease (alpha-CD) without detectable amounts of alpha-CD protein in serum are reported. Both patients presented with the usual epidemiologic, clinical and pathologic features of alpha-CD, including a predominantly plasmacytic infiltration of the whole small intestine, alpha-CD Protein was found in the jejunal fluid in one case but not in the other, the latter presenting as a "nonsecretory" form of alpha-CD. In both cases, immunofluorescence study of the small bowel mucosa showed that most of the infiltrating cells were positive for alpha chains and negative for other isotypes, and kappa and lambda light chains. These findings warrant a reevaluation of the prevalence of alpha-CD protein synthesis in immunoproliferative small intestinal disease (IPSID) (including lymphomas previously described as Mediterranean lymphoma) by performing an adequate search for alpha-CD protein in the jejunal juice, and at the cellular level in patients without detectable amounts of this protein in serum.

Adult↗

Light- and electron-microscopic immunocytochemistry of glutamic acid decarboxylase (GAD) in the basal hypothalamus: morphological evidence for neuroendocrine gamma-aminobutyrate (GABA).

GABAergic cells and axon terminals were localized in the basal hypothalamus of differnet species (rat, mouse and cat), by means of an immunocytochemical approach using a specific and well-characterized antiserum to the GABA biosynthetic enzyme, glutamate decarboxylase. Light-microscopic visualization was performed with an indirect immunofluorescence method and electron-microscopic observations were made on material with pre-embedding staining and use of the peroxidase-antiperoxidase procedure. At the light-microscopic level, a dense immunofluorescent plexus was observed over both the medial and lateral parts of the external layer of the median eminence. The labelling extended from the rostal part of the median eminence up to the pituitary stalk. Over the subependymal and internal layers only a few immunoreactive dots were visible, except around the blood vessels where they appeared more concentrated. Immunoreactive varicosities could be found following the outlines of the capillary loops and lining tanycyte processes, especially in the median eminance midportion. At the electron-microscopic level, the immunolabelling was exclusively found over neuronal profiles in the median eminence. The latter represented a small fraction of the total number of varicosities visible on the same section. Labelled profiles typically contained numerous small clear synaptic vesicles and only a few or no dense-core vesicles. In the subependymal and internal layers, rare labelled endings were found close to ependymal cells or among transversally cut fibers, respectively. In the palisadic zone, elongated positive boutons were visible intermingled with bundles of unlabelled axons and glial or ependymal processes. In the neurohemal contact zone, immunoreactive endings were observed among unlabelled neurosecretory endings in close vicinity to fenestrated capillary perivascular space. Small moderately intense immunofluorescent varicosities were observed all over the hypothalamus. The density of the glutamate decarboxylase-positive network was higher than in most diencephalic regions. Intraventricular or topical injection of colchicine allowed the visualization of small lightly immunoreactive cells in the diffusion area of colchicine. In the arcuate nucleus labelled axonal endings containing small pleomorphic synaptic vesicles and sometimes a few dense-core vesicles were observed at the electron-microscopic level. Typical synaptic junctions were commonly found between positive endings and unlabelled perikarya, or more frequently, unlabelled dendrites. These findings show that glutamate decarboxylase-containing endings are localized ed in several strategic sites for potential GABAergic neuroendocrine regulations. The GABAergic endings found among neurosecretory endings in the neurohemal contact zone may provide the morphological support for the release of gamma-aminobutyrate into the portal blood flow as an hypothalamic hypophysiotropic hormone.

Animals↗

Ethacrynic acid facilitates gentamicin entry into endolymph of the rat.

Influence of ethacrynic acid (EA) upon gentamicin kinetics in perilymph and endolymph was studied in rats that were given a constant-infusion of gentamicin (150 micrograms/min) and EA (140 micrograms/min). Inner ear fluids and plasma were sampled up to 5 h. The purity of the endolymph was ensured by measurement of sodium and potassium concentrations. Gentamicin assay was done with a modified radioimmunoassay. Results show that EA facilitates the entry of gentamicin into endolymph, while it does not affect the kinetics of the drug in perilymph. Although the mechanism of this facilitation remains unclear, this result may account for the ototoxic potentiation reported between EA and aminoglycoside antibiotics.

Animals↗

A double-blind controlled trial of two dose levels of factor VIII in the treatment of high risk haemarthroses in haemophilia A.

One hundred and thirteen haemarthroses involving the knees, ankles and elbows of 29 severe haemophiliacs presenting with at least two of the risk factors, pain, tenderness, loss of more than 50% of movement and a delay of more than 3 h in treatment were studied. Each was given either a 20% or 40% dose of factor VIII and progress was then reviewed by medical staff unaware of the initial dosage. There was no significant effect on the retransfusion rate nor on the time to complete resolution. However, the difference between the percentage of patients showing residual movement restriction was significantly in favour of the high dose at 24, 36 and 48 h when all the bleeds were pooled and at 48 h for elbow bleeds.

Blood Transfusion↗

Gentamicin persistence in rat endolymph and perilymph after a two-day constant infusion.

The kinetics of gentamicin in the inner ear fluids of rats were studied up to 15 days after cessation of a 2-day constant infusion of 10 micrograms/min. In endolymph, the concentration of gentamicin persisted at about 1 microgram/ml for up to 15 days, precluding the determination of the half-life of the drug in this fluid. In perilymph, gentamicin cleared more slowly than after a shorter period of infusion. These results suggest that the tissues of the inner ear could bind the aminoglycoside and then slowly release it into the surrounding fluids.

Animals↗

The clinical features of early bleeding into the muscles of the lower limb in severe haemophiliacs.

The clinical features, management and outcome of 178 early bleeding episodes into the musculature of the thigh and lower limb of 37 severe haemophiliacs are reported. Ninety-five per cent of all bleeds were treated in under three hours from onset of symptoms and the mean time to complete restoration of function was 3.5 days. The most frequent site of bleeding was the quadriceps (44 per cent) followed by the calf (35 per cent), anterior tibial compartment (seven per cent), adductors of the thigh (seven per cent), hamstrings (six per cent) and sartorius (one per cent). Bleeds of the quadriceps took longest to resolve (mean, four days), significantly longer than bleeds of the calf muscle (3.1 days). The first symptom in 66 per cent of bleeds was pain on movement. When the quadriceps was involved, this rapidly progressed to pain at rest. There was a significant prolongation of recovery time when bleeds of this muscle group were treated more than two hours after the onset of symptoms. Bleeds of the calf muscle required less transfusions and no prolongation in recovery time occurred in bleeds treated up to three hours from the onset of symptoms. The results of this study contrast markedly with earlier reports based on later presentations.

Blood Transfusion↗

[The parotid fascia].

The parotid fascia is not the superficial layer of the investing layer of the cervical fascia. The dissection of 21 cadavers, the histological studies and the compared anatomy of 3 apes show that the parotid gland lies between the platysma muscle on the lateral side and the superficial layer of the cervical fascia on the medial side. The upper part of the platysma, large muscle in apes, has regressed as a fibrosis layer in man.

Adult↗

[Gonococcal endocarditis. A new case].

The authors report the case of a 35 year old female hospitalised for gonococcal endocarditis with mitral valve vegetations infecting pre-existing asymptomatic rheumatic mitral incompetence. Apyrexia was rapidly obtained with antibiotic therapy; the valvulopathy was well tolerated from the hemodynamic viewpoint; the echocardiographic appearances of the vegetations were stable. However, the patient died during the third week of a cerebral haemorrhage, probably due to rupture of a mycotic arterial aneurysm. The authors suggest that the difficulties encountered in the fight against sexually transmitted diseases may result in a recrudescence of this type of disseminated gonococcal infection.

Adult↗

Diffuse follicular lymphoid hyperplasia of the small intestine without primary immunoglobulin deficiency.

Three cases of follicular lymphoid hyperplasia extending to the whole length of small intestine are reported in three young adult patients of low economic status. The disease was revealed by chronic diarrhea with malabsorption and/or protein-losing enteropathy. In one patient, all transitional patterns were found between the hyperplastic follicles and a small intestinal multicentric centrocytic-centroblastic lymphoma. No abnormalities in humoral or cellular immunity were found in the three patients. In particular, serum immunoglobulins (except IgG in one case) and plasma cell populations of small intestinal lamina propria were normal. Diffuse follicular lymphoid hyperplasia of the small intestine in the absence of primary immunoglobulin deficiency appears to be a rare condition associated with (or leading to) intestinal malignant lymphoma in most cases. Patients usually belong to the same populations as those suffering from alpha-chain disease.

Adolescent↗

The identification of high risk knee bleeds in adolescents with severe haemophilia A.

One hundred and thirty-seven knee bleeds treated with an initial dose of 11-16 units of factor VIII/kg have been reviewed in an attempt to find the predictive factors for bleeds requiring retransfusion. Thirty-two bleeds (23.4%) were retransfused within 48 hours because of extension of bleeding or poor progress. Fifty-nine per cent of bleeds which were retransfused presented with pain and 72% were tender at presentation. These figures contrasted with those for bleeds which were not retransfused of 30% and 45%. The difference in each case is significant. Forty-seven per cent of retransfused bleeds presented with less than 50% of normal movement against 12% who were not retransfused. This difference was also highly significant. It is suggested that knee bleeds presenting with pain, tenderness and/or more than 50% restriction of movement should be considered for higher initial doses of factor VIII.

Adolescent↗

The use of an activated factor IX complex (Autoplex) in the management of haemarthroses in haemophiliacs with antibodies to factor VIII.

A new activated factor IX product (Autoplex) has been used for the treatment of 18 haemarthroses in three haemophiliac patients with antibodies to factor VIII and a history of high anamnestic response to challenge with factor VIII. Results were evaluated by assessing pain, tenderness, range of movement and girth at 8 and 24 hours. A score of 2 was given for improvement at 8 hours and 1 for improvement at 24 hours. The result was expressed as a percentage of the possible score. Nine episodes treated with less than 35 units of Autoplex/kg had a mean score of 52% and nine episodes treated with more than 35 units/kg had a mean score of 73%. When only the more severe group of bleeds was considered, an even more marked dose related response emerged. When the ratio of the percentage fall in the PT to the percentage fall in the KCCT was plotted against the outcome, a significant correlation emerged (r = 0.43; P = 0.02).

Adolescent↗

Effect of height and weight on the in vivo recovery of transfused factor VIII C.

The in vivo recovery of factor VIII has been estimated on 84 occasions in 53 severely affected adolescent haemophiliacs. There was wide individual variation in recovery, which was not affected by differences in the administered dose. Recovery increased steadily with increasing surface area, and it was only over a surface area of 1.7 m2 that a recovery of 2% of factor VIII per unit per kg became the norm. It is suggested that the only safe assumption to make below that surface area in an in vivo recovery of 1.5%.

Adolescent↗

[Undifferentiated carcinoma with lymphoid stroma (undifferentiated carcinoma nasopharyngeal type?). Optical, electron microscopical and immunofluorescence study (author's transl)].

A case of undifferentiated carcinoma with lymphoid stroma of the paired gland is reported in a chinese woman with positive Epstein-Barr virus serology. The histologic appearance of the tumor is very similar to undifferentiated carcinomas nasopharyngeal type (UCNT). Ultrastructural study reveals features of epidermoid differentiation. Immunofluorescence study shows numerous and predominant IgA plasma cells in the stroma. The relationship between this tumor and the benign lymphoepithelial lesions of the salivary glands are discussed. The present case and the review of the literature emphasize the morphological and epidemiological similarities between UCNT and undifferentiated carcinoma with lymphoid stroma of the salivary glands.

Adult↗