Search PubMed⌕ Search

Biomedical subjects

M Mansour

Publications and source records attributed to M Mansour.

At least 91 records · Page 5Linked to original sources
PubMed1992

The importance of acute luminal diameter in determining restenosis after coronary atherectomy or stenting.

BACKGROUND: We evaluated native coronary arteries treated by directional coronary atherectomy or balloon-expandable stent placement in an effort to derive a quantitative geometric model relating the luminal diameter immediately after intervention to that present 6 months later. The minimal luminal diameter of each lesion was measured before and immediately after intervention in 102 single Palmaz-Schatz stents and 134 directional atherectomies, 192 (81%) of which had repeat angiographic measurement of minimal luminal diameter 6 months after the intervention. The immediate enlargement in luminal diameter produced by the intervention (acute gain) and the subsequent reduction in luminal diameter from the time of intervention to 6 months of follow-up (late loss) were calculated. METHODS AND RESULTS: Luminal diameter increased from 0.69 +/- 0.40 mm to 3.11 +/- 0.64 mm (acute gain, 2.41 +/- 0.64 mm) after intervention, providing an immediate postprocedure residual stenosis of 1 +/- 14% relative to a reference diameter of 3.13 +/- 0.65 mm. At 6-month follow-up, the late luminal diameter was 1.97 +/- 0.92 mm (late loss, 1.13 +/- 0.89 mm), yielding a late diameter stenosis of 36 +/- 26%. The restenosis rate (according to the traditional definition of diameter stenosis > or = 50%) was 30%. Multivariable analysis demonstrated that late luminal diameter (p = 0.02), late percent stenosis (p = 0.04), and restenosis (according to a > 50% definition, p = 0.04) were each strongly associated with the luminal diameter present immediately after the procedure. Whereas late luminal diameter was also influenced by reference artery size and the vessel treated (left anterior descending versus right coronary artery), reference vessel size was rejected by the multivariable models of late percent stenosis and binary restenosis after they were adjusted for the effect of postprocedure luminal diameter. Once adjusted for postprocedure luminal diameter, neither late luminal diameter nor late loss was found to be independently determined by which device was used (atherectomy versus stents). Rather, late loss was determined independently by the immediate postprocedure luminal diameter (p = 0.005) and the postprocedure percent stenosis (p = 0.02). Although late loss thus increased with acute gain, the net beneficial effect of increased acute gain was maintained: Late loss was only a fraction (0.47) of acute gain, so the ability of a larger postprocedure luminal diameter to reduce the probability of subsequent restenosis was preserved. CONCLUSIONS: This quantitative model demonstrates that the late coronary lumen diameter and the probability of restenosis after Palmaz-Schatz stenting or directional atherectomy are influenced strongly by the lumen diameter present immediately after the procedure rather than by the specific device used. Although the influence of a larger acute result on reduced restenosis appears to be well established in this treatment population, the interplay among the multiple other biological influences on restenosis limits the ability to predict the probability of restenosis for the individual patient based on a large acute result alone. Future studies of restenosis, however, can further refine this multivariable quantitative model by adjusting for the effects of other clinical variables, mechanical interventions, or drug therapies in addition to the clear effect of postprocedure luminal diameter.

Atherectomy, Coronary↗
PubMed1992

Antiphospholipid antibodies require beta 2-glycoprotein I (apolipoprotein H) as cofactor.

IgG was isolated from 9 patients with high levels of anticardiolipin antibodies (aCL). The standard ELISA was modified, using gelatin to postcoat ELISA plates and as diluent. Under these conditions, 8/9 samples of IgG bound to cardiolipin only in the presence of a cofactor, found in fetal calf serum and normal human serum (NHS). beta 2-glycoprotein I (apolipoprotein H) was at least as effective as NHS as a cofactor for 7/9 IgG samples. Our studies confirm that for some aCL detected in conventional assays, the antibody will react with cardiolipin only if beta 2-glycoprotein I is present.

Antibodies, Antiphospholipid↗
PubMed1991

Formation and proliferative effects of lipoxins in human bone marrow.

Lipoxins A4 and B4 together with the all-trans lipoxin (LX) isomers were produced by normal human bone marrow cell suspensions after incubation with ionophore A23187. Both LXA4 and LXB4 enhanced the growth of myeloid progenitor cells in semisolid agar in the presence of suboptimal concentrations of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF). Lipoxin A4 at 10(-10) M stimulated the colony formation in 13 out of 15 tested human bone marrows with a mean (+/- SEM) increase of 47 +/- 11% (p = 0.001). A similar stimulatory effect was observed after addition of LXB4 (10(-10) M). The monohydroxyeicosatetraenoic acids 5-, 12- and 15-HETE did not affect colony growth. In addition, LXA4 (10(-8) M) efficiently counteracted the increased colony formation induced by leukotriene C4 (10(-10) M), suggesting an antagonistic relationship between these lipoxygenase products. The results support a role for lipoxins in the regulation of human myelopoiesis.

Bone Marrow↗
PubMed1991

Immunoglobulins of the snake Psammophis sibilans. Studies using a monoclonal antibody.

A mouse monoclonal antibody (mAb) raised against serum immunoglobulins (Ig) of the snake. Psammophis sibilans stained in indirect immunofluorescence a proportion of snake splenic and peripheral blood lymphocytes, whereas it did not react with thymocytes, erythrocytes, brain, heart, lung, liver or kidney cells. The mAb, designated SR-2, combined in enzyme-linked immunosorbent assay (ELISA) with serum proteins of each of 20 individual P. sibilans tested. On Western blots of P. sibilans reduced whole serum proteins, purified Ig, or anti-rat erythrocyte (RRBC) antibodies eluted from glutaraldehyde-fixed RRBC, mAb SR-2 identified two bands of apparent molecular weight (m.w.) of 60,000 and 51,000 daltons. These bands were due to distinct polypeptides and not resulting from heterogeneous glycosylation of a single polypeptide, as they both were readily detected after periodate oxidation or endoglycosidase-F treatment of serum proteins and isolated Ig. MAb SR-2 bound to CNBr-activated Sepharose 4B precipitated from P. sibilans 125I-labeled serum proteins under non-reducing conditions a band that did not enter 7.5 or 9-16% gel and one of about 150,000 daltons. Under reducing conditions, two heavy bands of approximately 63,000 and 50,000 daltons and two light chains of apparent mass 23,000 and 20,000 bands were precipitated. The data presented provide, for the first time, substantial information on the molecular characteristics of snake Ig.

Animals↗
PubMed1991

Multiple mentoring strategy in the academic preparation of quality assurance directors.

Availability of adequately educated and trained nursing quality assurance directors is a must for the survival of health care institutions. Educators meet many challenges in preparing masters students for this role. Issues pertaining to definition of a relevant course of study in theoretical and practical content areas, and faculty's lack of personal experience with the role are situations that must be resolved. This article describes a model of multiple mentoring through collaboration that was implemented at a large urban nursing department with satisfactory solutions.

Education, Nursing, Graduate↗
PubMed1990

[Acute respiratory distress syndrome in the initial phase of myocardial infarction in adults].

Four patients developed an acute respiratory distress syndrome characterised by clinical and radiological signs of pulmonary oedema, a protein-rich oedema, severe hypoxemia refractory to oxygen therapy, contrasting with normal left ventricular filling pressures and indicating increased permeability of the alveolo-capillary membrane, 24 to 72 hours after the onset of acute myocardial infarction. After having excluded the usual causes of the acute respiratory distress syndrome, the authors suggest that acute myocardial infarction, especially when extensive, may cause a lesion of the alveolo-capillary membrane by an unknown mechanism. Treatment consisted in mechanical ventilation with positive expiratory pressures in 3 cases and with continuous positive pressure during spontaneous respiration in the third patient and in relay with controlled ventilation in the other two. These techniques of ventilation improved the hypoxemia and led to complete cure in all cases without evolution to pulmonary fibrosis. In addition to mechanical ventilation, all patients were given systematic antibiotic therapy because of the possibility of an infectious etiology while waiting for the results of microbiological and serological testing and because of the high risk of superinfection which plays an essential part in the outcome of the condition. The immediate response to treatment was favourable in all cases. One patient died suddenly of cardiogenic shock two weeks after this episode. The other patients are still alive 39, 38 and 20 months after infarction. The importance of the diagnosis of the acute respiratory distress syndrome in the acute phase of myocardial infarction resides in its therapeutic implications which are quite different to those of cardiogenic shock.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

HIV infection surveillance in Mogadishu, Somalia.

A group of 89 prostitutes and 45 patients attending sexually transmitted disease clinics in Mogadishu, Somalia were examined for evidence of HIV infection. Both groups reported more than 1 sexual partner routinely and had sexual contacts with prostitutes. There was a significant amount of sexually transmitted diseases (STDs) in these two groups, with 11.2% and 6.7% respectively being culture positive for N. gonorrhoea. Among the prostitutes, 28.1% were positive for antibodies to T. pallidum while only 4.4% of the STD patients were positive. One isolate of N. gonorrhoea was resistant to penicillin. All study participants were negative for antibodies to HIV suggesting an extremely low prevalence of HIV in high risk behaviour groups in the capital city of Somalia.

Adult↗
PubMed1990

[In Tunisia: description of a health education program based on socio-cultural realities].

Structured within the framework of the National Programme for the Fight Against Diarrhoea in Tunisia, (PNLAD) the goal of the LAD Project is to improve the understanding and in-home treatment of diarrhoea by mothers. The programme consists of three elements: education of the mothers through health centers and preschool institutions, training of health care and social workers, and a mass media campaign. This article discusses the education programme for mothers through preschool institutions. Before embarking on its education programme, the project team conducted a preliminary study in order to establish what level of knowledge of diarrhoea existed among the general population and what current treatment methods were used. The study consisted of small discussion groups composed of mothers, grandmothers, and fathers. In evaluating current notions regarding diarrhoea, the study noted the various vocabulary used and its meaning for both diarrhoea and dehydration. It also examined the general beliefs of what caused diarrhoea and what people believed would cure and/or prevent the disease. As far as treatment methods were concerned, it was important to understand the origins of the various remedies, the level of awareness of the formal and informal health channels that existed and the different kinds of treatment based on diet, mother's milk, liquids, saline/sugar solutions and medication. The second key aspect of the programme concerned the kind of educational materials and teaching methods used. Both had to be geared towards the teaching of adults while insuring a real exchange of knowledge and experience between the population and the development personnel.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Annulo-aortic ectasia].

On the basis of a literature review and the study of 18 cases, the authors examine annuloaortic ectasia, which involves dilatation of the fibrous ring of the heart at the aortic orifice, marked by aortic regurgitation and dystrophic aneurysm of the ascending aorta. The authors noted a predominantly muscular disorder (14 males, 4 females) often detected from an assessment of aortic regurgitation without clinical, radiologic or specific electrical features. The value of echocardiography and Doppler echocardiography is clearly apparent from the diagnosis of the disease, monitoring of progress, selection of patients for invasive pre-operative explorations and post-operative surveillance. The developing gravity of this disease is stressed, rapid repercussions in the left ventricle intervening more than complications due to ectasia itself. This indicates the urgency of complete replacement of the whole ascending aorta and of the aortic valve with reimplantation of coronary arteries as in the Bentall or Bentall-Cabrol surgical intervention, seven cases of which have been reported with satisfactory results.

Adult↗
PubMed1990

The use of the bromine partition test in the diagnosis and prognosis of tuberculous meningitis.

The bromine partition test was successfully used to differentiate cases of proven tuberculous meningitis from patients with aseptic and non-tuberculous meningitis. Forty patients, 22 males and 18 females aged 5 to 30 years (mean 13.5 +/- 6.2), were included in the study. Nineteen patients were confirmed to have tuberculous meningitis, 12 had aseptic meningitis, and 9 bacterial meningitis. All patients received 0.6 mci/kg of bromine 82 administered through a nasogastric tube as ammonium bromide dissolved in 5 ml of isotonic sodium chloride. The serum to CSF bromine ratio was then calculated 48 hours after the dose. The test was then repeated 8 days later in patients with bacterial meningitis and 8, 90, and 180 day later in patients with tuberculous meningitis. The test was very useful in quickly differentiating cases of aseptic from bacterial and tuberculous meningitis and was also a useful prognosticator in patients with severe tuberculous meningitis.

Adolescent↗
PubMed1990

Correction of reentrant atrioventricular tachycardia by surgical ablation of accessory pathways.

Patients with reentrant atrioventricular (AV) tachycardia have an accessory connection in addition to the normal conduction pathway, AV node and His-Purkinje system. This pathway predisposes some patients to recurrent, disabling supraventricular tachyarrhythmias. Although it is found with other associated cardiac conditions, most patients are healthy with no underlying structural heart disease. Interest has developed in surgically dividing the accessory pathway in patients with arrhythmias poorly controlled with medications or at risk for potentially fatal tachyarrhythmias. Surgery is safe and effective and should be considered for patients with rapid AV conduction during atrial fibrillation, those refractory to pharmacologic therapy, and young patients who otherwise would require lifelong antiarrhythmic therapy. This report describes surgical correction of reentrant AV tachycardia in five patients ranging in age from six months to 23 years.

Adolescent↗
PubMed1990

Effect of gamma irradiation on the rate of cyst development of E. granulosus larvae in Swiss albino mice.

White albino mice Mus Musculus albinus were intraperitoneally inoculated with aseptical normal and gamma irradiated protoscolices of E. granulosus at dose level of 40, 60, 80 and 100 Kr. Mice, either normaly infected or infected with irradiated protoscolices and sacrificed at intervals of 4, 6, 8, 10, 12, 14 and 16 weeks, showed a marked increase in the percentage of cyst number in the liver than in the peritoneal cavity or around spleen, although by increasing the dose level to 100 Kr. no cyst were developed around the spleen. Meanwhile the % of developing cyst in the peritoneal cavity was time and dose level dependent. The mean cyst diameter showed a progressive increase with the increase of infection time and a successive decrease by increasing the dose level of gamma irradiation. An increase in the number of cyst was observed particularly in normal mice where a marked increase was noted on the 8th week post infection while a successive decrease in the mean number of cyst was observed by increasing the dose level of gamma irradiation.

Animals↗
PubMed1989

A substrate amplification system for enzyme-linked immunoassays. II. Demonstration of its applicability for measuring anti-DNA antibodies.

We have recently described a substrate amplification system, based on the method of Self, which increases the sensitivity of alkaline phosphatase (AP)-dependent enzyme-linked immunosorbent assays (ELISA) by a factor of 30-50. This increase is achieved by having AP, the primary enzyme, produce an activator for a secondary enzyme-substrate system, within which marked amplification occurs. We have now demonstrated that this amplification method can be applied to the measurement of human antibodies to DNA. The sensitivity is greater by a factor of 10 than the conventional method, which uses p-nitrophenyl phosphate (p-NPP) as substrate. On replicate assays the method is reproducible, with a coefficient of variation of less than 0.1. This great increase in sensitivity should be of value in conserving specimens of serum and in screening monoclonal antibodies.

Alkaline Phosphatase↗
PubMed1989

Antibody to carbohydrate and polypeptide epitopes on the surface of schistosomula of Schistosoma mansoni in Egyptian patients with acute and chronic schistosomiasis.

125I-Schistosoma mansoni schistosomulum surface antigens were immunoprecipitated with human antibodies from individual Egyptian patients diagnosed as being either acutely or chronically infected with S. mansoni. Both sets of patients were found to have IgG antibodies in their sera capable of immunoprecipitating the major Mr greater than 200, 38 and 32K antigens. However, the immunoprecipitation of the Mr greater than 200K antigen was found to constitute a significantly greater proportion of the total precipitate achieved with acute sera than with chronic sera. The Mr 38 and 32K antigens were more variably precipitated by the acute sera than the chronic sera but the proportion of the total precipitation that these two antigens constituted was not found to be significantly different between the two sets of sera. Immunoprecipitation with pooled antibodies absorbed with egg and adult worm homogenates which had been treated to remove either carbohydrate or polypeptide epitopes demonstrated that the Mr greater than 200K antigen was the principal target of egg-cross-reactive anti-carbohydrate antibody amongst the antigens detected. The Mr 38 and 32K antigens were found to be precipitated by antibodies to protease-sensitive and periodate-insensitive polypeptide epitopes. These results are consistent with egg-cross-reactive anti-carbohydrate IgG antibody making a greater contribution to schistosomulum surface recognition in acute infection than in chronic infection. Indeed the presence of a higher level of egg-cross-reactive and anti-carbohydrate antibody directed against schistosomulum surface epitopes in an acute serum pool than in a chronic serum pool was confirmed by measurement of antibody binding to whole schistosomula.

Acute Disease↗
PubMed1989

Optimization of symptomatic therapy in Parkinson's disease.

A third-order nonlinear mathematical model of the dose-effect relationship of levodopa, one of the most common drugs used for the symptomatic therapy of Parkinson's disease, is derived with the aid of a visual tracking based method which allows the measurement of some Parkinsonian symptoms quantitatively and objectively. The parameters of this model are identified for each subject separately due to the large interpatient variability in response to treatment. The model is then used to optimize the dosage regimen for each patient individually (according to the clinical particularities and needs of each patient) with respect to an objective function which includes the symptoms dynamically and the total amount of levodopa which is to be administered. Encouraging clinical results of this control engineering approach to therapy optimization are presented. The advantages and drawbacks of this approach are discussed and further research directions are indicated.

Benserazide↗
PubMed1989

Cytokines and immunoglobulin in rheumatic heart disease: production by blood and tonsillar mononuclear cells.

Rheumatic fever and rheumatic heart disease are considered to result from abnormal immune responses after Group A streptococcal pharyngitis. Production of interleukin 1 (IL-1), tumor necrosis factor-alpha (TNF), interleukin 2 (IL-2) and immunoglobulin (Ig) by blood and tonsillar mononuclear cells from rheumatic or healthy children was measured after stimulation in vitro by pokeweed mitogen (PWM) or the streptococcal extracellular product, blastogen A (BLA). Tonsillar cells from patients with rheumatic heart disease produced significantly less IL-1, TNF, IL-2, and Ig than control tonsillar cells. In contrast, blood mononuclear cell cultures from rheumatic children produced more TNF and IL-2 than controls. Our findings suggest that abnormal regulation of cytokine and Ig production may contribute to the pathogenesis of acute rheumatic fever and rheumatic heart disease.

Cells, Cultured↗
PubMed1989

New approaches to management of arrhythmias after myocardial infarction.

More effective modalities for the evaluation and management of arrhythmias in the postinfarction patient continue to evolve. They offer the hope of significantly ameliorating the morbidity and mortality associated with these arrhythmias. Although arrhythmias and disturbances of conduction are among the most important and potentially lethal consequences of myocardial infarction, advances in evaluation and management of these problems have helped to improve prognosis for these patients. Greater long-term arrhythmia-free survival can be achieved when therapy is guided by programmed electrical stimulation. Pacemakers, newer antiarrhythmic drugs, the automatic implantable cardioverter-defibrillator, catheter ablation, and surgery are all important tools in the management of ventricular arrhythmias and the prevention of sudden death.

Anti-Arrhythmia Agents↗