PubMed Health⌕ Search

Biomedical subjects

S Hussein

Publications and source records attributed to S Hussein.

At least 19 recordsLinked to original sources
PubMed1991

Increased tumorigenicity of fibronectin receptor deficient Chinese hamster ovary cell variants.

We have developed a series of variant clonal Chinese hamster ovary cell sublines which are deficient in the expression of the alpha 5/beta 1 integrin fibronectin receptor. When these clonal sublines were injected s.c. into nude mice, there were marked differences in the rate of tumor growth. Tumors from clones expressing very low levels of fibronectin receptor grew most rapidly, clones expressing levels of fibronectin receptor comparable to wild type cells grew at an intermediate rate, while a clone expressing elevated levels of fibronectin receptor grew slowly. Cells recovered from the tumors maintained their original phenotypes in terms of levels of fibronectin receptor expression. These results suggest that there is an inverse correlation between the level of expression of the alpha 5/beta 1 fibronectin receptor and the rate of tumor growth.

Animals↗
PubMed1991

The anterior inferior cerebellar artery (AICA): clinical and radiological significance.

It is well known that the anterior inferior cerebellar artery (AICA) is difficult to visualize radiologically. As the analysis of 50 clinical cases shows, although the main branches of the AICA at the level of the basilar artery can be analyzed angiographically, the peripheral course is only vaguely visible. We examined 26 brains (postmortem) after selective resin-injection and preparation under an operation-microscope. Our results: 1. There is a reciprocal relationship between the development of the AICA and the PICA. 2. We can draw no conclusions concerning the pattern of the AICA of one side to the pattern on the other side. 3. The size of the AICA at the level of the basilar artery gives an indirect indication of the peripheral course. 4. The AICA and the cranial nerves are in a constant relationship to each other. Consideration of these relationships can help in the interpretation of angiograms done before microsurgical operations in the area of the cerebello-pontine angle.

Arteries↗
PubMed1991

An evaluation of the Sysmex NE-8000 hematology analyzer.

The Sysmex NE-8000 is a new, fully automated hematology analyzer capable of providing a five-part white blood cell differential count and identifying abnormal specimens. This instrument was evaluated on 5,000 consecutive blood specimens and compared to the Coulter S Plus-IV analyzer and manual differential cell counts to determine the efficacy of its five-cell differential and screening capabilities. There was a high correlation between the commercial counters for the standard parameters, white blood cell count, red blood cell count, hemoglobin level, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration, and platelet count (r greater than 0.95), except for the mean corpuscular hemoglobin concentration (r = 0.51), for which the NE-8000 was considered the more accurate measurement. Precision and linearity studies were excellent. The white blood cell count, red blood cell count, hemoglobin level, and platelet count were reproducible on specimens stored at 4 degrees C or room temperature for 72 hours and the differential counts were reproducible for 12 hours. The correlations between automated and manual counts for neutrophils, eosinophils, basophils, and lymphocytes were excellent: r = 0.912, 0.945, 0.332, and 0.964, respectively. The monocyte correlation improved with software modification from 0.306 to 0.801. The NE-8000 gave accurate and reproducible differential counts for neutrophils, lymphocytes, and monocytes on specimens with white blood cell counts as low as 0.6 x 10(9)/1. The ability of the instrument to 'flag' abnormal specimens was excellent. The false-positive rate on normal samples was 1.8%, and the false-negative rate on known abnormal samples was 0.3%, due only to nonrecognition of a mild left shift. The identification of specific abnormalities was less precise. The NE-8000 is a powerful hematology analyzer that can perform a five-part white blood cell differential count accurately for a wide range of WBCs and reliably indicate abnormal specimens. It is an excellent screening tool for distinguishing between normal and abnormal specimens and identifying those that require microscopy. Its reliability significantly reduces the need for manual film examination.

Blood Cell Count↗
PubMed1991

Four cases of IgD multiple myeloma.

The pathological and clinical findings in 4 cases of IgD multiple myeloma are presented. Two patients presented with renal failure and 2 with bone pain and weight loss. Three had IgD lambda paraproteins and 1 an IgD kappa paraprotein. One patient also developed hypercalcemia and extraosseous spread of tumor to pleura, skin, and palate. There were no distinctive bone marrow or histological findings which suggested this unusual type of myeloma.

Aged↗
PubMed1990

[The topography of the atrium ventriculi and its microsurgical importance].

Microsurgical anatomy of the atrial region of the side cerebral ventricles was studied on 100 brain hemispheres. The variations in the form of the atrial walls, especially the structures comprising the anterior atrial wall were analysed in respect to the microsurgical possibilities. According to the anatomical results a microsurgical approach was described: the interhemispheric transatrial approach for lesions of the trigonal atrial region. Advantages and disadvantages, possibilities and limits of this approach in comparison to alternative approaches are discussed.

Adult↗
PubMed1990

[Misinterpretation of the adhesio interthalamica and the commissura epithalamica (posterior) in occlusive hydrocephalus in the computed tomogram].

As a cause of an occlusive hydrocephalus, sometimes by CT a cystic malformation of the third ventricle is falsely assumed. This misinterpretation is based on the enlargement of the ventricular system, which leads to an unusual visualization of the interthalamic adhesion and the epithalamic (posterior) commissure. We show these structures to be the reason for the misleading diagnosis by comparing anatomical sections, ventriculography and magnetic resonance imaging (MR) with each other. Finally we discuss the clinical significance by presenting cases, in which an operative treatment of the so called "cyst" already had been planned. For the definite diagnosis we favor MR.

Cerebral Ventriculography↗
PubMed1989

Isolation and characterization of Chinese hamster ovary cell variants deficient in the expression of fibronectin receptor.

Chinese hamster ovary cell populations were enriched for cells displaying low surface expression of the 140-kD integrin fibronectin receptor (FnR) by means of fluorescence-activated cell sorting using monoclonal anti-FnR antibodies. Selected cells were cloned by limiting dilution, and the resulting clones were screened for low cell surface FnR expression by ELISA. Two multiply sorted populations gave rise to variant clones possessing approximately 20 or 2% FnR expression, respectively, compared with wild-type cells. Growth rates of the "20%" and "2%" clones on serum-coated plastic dishes were similar to that of wild-type cells. Variant cells expressing 20% FnR could attach and spread on substrata coated with purified fibronectin, although somewhat more slowly than wild-type cells, while cells expressing 2% FnR could not attach or spread. Cells from all variant clones attached normally to vitronectin substrata, but some of the 2% clones displayed altered morphology on this type of substratum. Motility assays in blind well chambers showed a correlation of movement with level of expression of FnR. The number of cells migrating in response to fibronectin was greatly reduced compared with wild-type cells for the 20% FnR variant clones, while variant clones with 2% FnR showed virtually no migratory activity. Surface labeling with 125I and immunoaffinity purification of FnR showed reduced levels of intact FnR on the plasma membranes of variants with 20% FnR, while none was detected in variants expressing 2% FnR. Nevertheless, beta subunits were detected on the surfaces of all variant clones. Immunoblots of cell lysates from wild-type cells and from both types of variant clones showed substantial amounts of FnR beta chain as well as enhanced amounts of a pre-beta moiety in the variants. alpha chain was markedly reduced in the 20% variants and essentially absent in the 2% variants, indicating that failure to assemble intact FnR in these variants was due to deficiencies of alpha chain production. Dot blots of total mRNA from a representative clone expressing 20% FnR showed reduced levels of material hybridizing to an 0.97-kb hamster FnR alpha chain cDNA probe as compared with wild type, while mRNA from a representative clone expressing 2% FnR had no detectable hybridizable RNA; this seems to agree well with the results obtained by immunoblotting. Thus, the defect in the variant clones seems to be due to reduced levels of alpha chain mRNA leading to a deficit of mature FnR and consequent alterations in cell adhesion and motility on fibronectin substrata.

Animals↗
PubMed1989

Single dose kinetic study of the triple combination mefloquine/sulphadoxine/pyrimethamine (Fansimef) in healthy male volunteers.

A single dose pharmacokinetic study of a combined antimalarial formulation of mefloquine, sulphadoxine and pyrimethamine (Fansimef) has been performed in 10 healthy adult male Malaysian volunteers. The dose consisted of two tablets containing 250 mg mefloquine base, 500 mg sulphadoxine base and 25 mg pyrimethamine base each. Plasma concentrations of mefloquine and pyrimethamine were measured by GC-ECD, those of sulphadoxine by h.p.l.c. Time to peak concentrations (mean +/- s.d. for mefloquine (5.70 +/- 0.95 h), sulphadoxine (3.75 +/- 2.03 h) and pyrimethamine (3.30 +/- 1.98 h) were similar to those observed by others after administration of the single compounds. This was also true for elimination half-lives (t1/2). The t1/2s for mefloquine, sulphadoxine and pyrimethamine were 387 +/- 98 h, 255 +/- 61 h and 114 +/- 42 h, respectively.

Adult↗
PubMed1989

[The postoperative treatment of hypertension with urapidil in patients with cerebrovascular aneurysms].

In 10 patients with subarachnoidal haemorrhage and an identified aneurysm the blood pressure was reduced intraoperatively by means of sodium nitroprusside. Arterial and intracranial pressures were continuously recorded in all patients. In 9 patients a rebound phenomenon occurred as manifested by an increase in blood pressure during the postoperative phase after sodium nitroprusside infusion. Rapid reduction of blood pressure was achieved in all patients by a bolus injection of initially 25 mg Urapidil. Undesirably low blood pressure values were seen in a patient. The continuously recorded intracranial pressure remained in the normal range in all patients. Blood pressure reduction by means of Urapidil does not exercise any influence on intracranial pressure, in contrast to blood pressure reduction via nitroglycerin, sodium nitroprusside, dihydroalacin and diazoxide.

Adult↗
PubMed1988

Microsurgical anatomy of the anterior choroidal artery.

The anterior choroidal artery (A.ch.a.) was studied in 140 hemispheres of the human brain. In 50 specimens the artery was cannulated and perfused with acrylic resin, in 20 specimens the A.ch.a., was selectively cannulated and perfused with dye. The artery then was microsurgically dissected and photographically documented. The site of origin of the A.ch.a., its length, outer diameter, course, branching patterns, anastomoses, and areas of supply was recorded. The surgical and diagnostic significance of the A.ch.a. and its importance during surgical procedures are discussed.

Autopsy↗
PubMed1988

Hyperprolactinemia and impotence.

One hundred impotent men and 15 sexually active male volunteers served as the source for this study. Serum prolactin was estimated in all cases using radioimmunoassay technique. Cases with hyperprolactinemia were treated with bromocriptine for 3 months. Hyperprolactinemia was detected in three patients only (3%), with no findings of pituitary tumors. Treatment with bromocriptine markedly reduced the level of serum prolactin together with improvement of sexual libido and potency. The mere presence of 3 cases only with hyperprolactinemia among 100 impotent subjects suggested that hyperprolactinemia is not one of the main causes of impotence.

Adolescent↗
PubMed1987

Study of DTH and resistance in Mycobacterium lepraemurium infection using a T-cell line isolated from mice infected with Mycobacterium bovis (BCG).

A T-cell line of mixed phenotype (60% L3T4+, 40% Lyt-2+) was isolated from mice infected with Mycobacterium bovis (BCG). This line responded to M. lepraemurium and BCG but not to M. leprae and produced TCGF spontaneously. It also produced factors which stimulated macrophages to secrete hydrogen peroxide and superoxide anion. In vivo studies showed that only L3T4+ cells were required to transfer DTH responses and that Lyt-2+ cells suppressed this response. Both L3T4+ and Lyt-2+ cells were required to inhibit M. lepraemurium multiplication in vivo.

Animals↗
PubMed1987

Cloning of human thymic subcapsular cortex epithelial cells with T-lymphocyte binding sites and hemopoietic growth factor activity.

The thymic microenvironment involves complex cell interactions among different types of epithelial cells, macrophages, tissue histiocytes, and immature and maturing T cells. We describe the isolation of a subset of thymic epithelial cells by selective primary culture followed by cotransfection with a simian virus 40 replication-origin-defective mutant and pSV2neo plasmid. The cloned cells have the composite immunophenotype that is unique to thymic subcapsular epithelial cells, suggesting that they may provide a model system in vitro for analyzing the earliest steps in T-cell differentiation. This possibility is supported by the finding that these epithelial cells express LFA-3-associated binding sites for T cells, secrete a macrophage hemopoietic growth factor, and synergize with macrophages in the production of interleukin 1.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1987

Platelets in idiopathic thrombocytopenic purpura are increased in size but are of normal density.

To determine whether platelet size and volume are related to one another or to platelet age, subpopulations of platelets from patients with idiopathic thrombocytopenic purpura (ITP) have been produced on the basis of density using Percoll gradients. The density distribution of platelets from patients with ITP and from patients with other forms of thrombocytopenia (thought to be nonimmune in nature) was the same as in normal controls. However, the platelets in each density subpopulation from ITP patients were increased in size. beta-thromboglobulin (beta TG) content of platelets from each patient group and the normals increased with density and tended to be higher in ITP than in normal controls. beta TG concentration per unit platelet volume and its level in plasma were similar in ITP patients and in normal controls. This suggests that the apparently normal density of ITP platelets was not a result of degranulation of large, dense platelets. Thus platelet size and density are independently determined and the increased size of platelets in immune thrombocytopenia may be the result of abnormalities in their production.

Blood Platelets↗