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S Zaher

Publications and source records attributed to S Zaher.

9 recordsLinked to original sources
PubMed1999

HLA class II associations with rheumatic heart disease are more evident and consistent among clinically homogeneous patients.

BACKGROUND: Discrepancies in reported HLA class II associations with rheumatic heart disease (RHD) may have been due to inaccuracies of serological typing reagents and/or lack of defined clinical classification of patients analyzed. The molecular association between HLA and RHD was investigated in patients with defined clinical outcome. METHODS AND RESULTS: Class II allele/haplotype distribution was determined in 2 groups of RHD patients (n=88) and a control group (n=59). Patients were divided into the mitral valve disease (MVD) category (ie, those with mitral regurgitation with or without mitral stenosis) and the multivalvular lesions (MVL) category, with impairment of aortic and/or tricuspid valves in addition to mitral valve damage. The MVD category (n=65) accounted for 74% of patients and included significantly fewer recurrent RF episodes compared with MVL patients (P=0.002). CONCLUSIONS: Significant increases in DRB1*0701 and DQA1*0201 alleles and DRB1*0701-DQA1*0201 haplotypes were found in patients. Removal of the MVL patients from analysis increased the strength of HLA associations among the MVD sample. The frequency of DQA1*0103 allele was decreased and the DQB1*0603 allele was absent from the patient group, suggesting that these alleles may confer protective effects against RHD. DQ alleles in linkage disequilibrium with DR alleles appear to influence risk/protection effect: whereas the DRB1*13-DQA1*0501-3-DQB1*0301 haplotype showed a trend toward risk, the DRB1*13-DQA1*0103-DQB1*0603 haplotype was absent in the RHD sample. Our data indicate that certain class II alleles/haplotypes are associated with risk or protection from RHD and that these associations appear to be stronger and more consistent when analyzed in patients with relatively more homogeneous clinical manifestations.

Adolescent↗
PubMed1993

Radiotherapeutic effect on oropharyngeal flora in patients with head and neck cancer.

The affect of radiotherapy on oropharyngeal bacterial flora was studied in the hope that this might help in controlling post-operative infections in previously irradiated patients. Eighty patients were included from whom swabs were taken before and at the end of irradiation, Swabs were also taken two weeks after treatment in the last 40 patients. Thirty healty controls were included. It was found that coagulase positive Staphylococcus aureus, beta-haemolytic streptococci, Candida albicans, B. proteus, and Pseudomonas aeruginosa, were significantly increased at the end of irradiation, while Klebsiella was increased significantly in the period after irradiation. Culture and sensitivity was performed for the organisms isolated in the last 40 patients. From this study it is evident that irradiation has a significant effect on oropharyngeal flora.

Adolescent↗
PubMed1992

Allergic aspergillus sinusitis with proptosis.

Allergic aspergillus sinusitis has recently been increasingly recognized. Five cases are discussed. All presented with proptosis, signs and symptoms of allergic rhinitis and radiological evidence of expansile masses with calcification and bony erosions involving multiple sinuses. Greenish cheesy material was seen at surgery. Histologically the lesions contained eosinophils, Charcot-Lyden crystals and fungal septate hyphae. Aspergillus fumigatus was grown from all cases. Surgical removal with drainage and aeration were performed. The follow-up period ranged between three to 18 months. Recurrence occurred in one patient. Allergic aspergillus sinusitis can mimic malignant disease and should be considered in the differential diagnosis of lesions involving multiple sinuses. It should also be considered in all cases of proptosis.

Adolescent↗
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↗
PubMed1988

Augmentation of cytotoxic activity by mitogens in rheumatic heart disease.

Natural killer cell activity and alterations in cytotoxicity after culture with streptococcal blastogen A and phytohemagglutinin (PHA) were examined in patients with inactive rheumatic heart disease (RHD) and control patients. Natural cytotoxic activity of mononuclear cells (MNC) did not differ between RHD and control patients with either peripheral blood or tonsils. In cultured blood MNC the level of cytotoxic activity stimulated by blastogen A was significantly greater in patients with RHD at all effector:target cell ratios. These differences in cytotoxic activity were not observed with cultured tonsillar MNC. In similar experiments with a different group of patients, culture with PHA or blastogen A both produced a significantly greater increase in cytotoxic activity in blood MNC from patients with RHD. The increase was significantly lower with PHA than with blastogen A. The ability of mitogens to differentially augment cytotoxic activity in cells from the blood of patients with RHD implies that a population of cells exists in these patients that could be activated during acute rheumatic fever to play a role in pathogenesis.

Adolescent↗
PubMed1987

Compartmentalization of cells bearing "rheumatic" cell surface antigens in peripheral blood and tonsils in rheumatic heart disease.

Monoclonal antibodies that recognize "rheumatic" antigens of peripheral blood non-T cells were used to study the compartmentalization of such cells in peripheral blood and tonsils of individuals with rheumatic heart disease (RHD) and suitable control subjects. The peripheral blood of most (71%) of the 42 individuals with RHD contained cells reacting with monoclonal antibody 83S19.23 or 256S.10, whereas these cells were present in only 17% of the 41 control subjects (P less than .02). However, none of 21 individuals with RHD had such cells in their tonsils, although they were present in the tonsils of 50% of the 40 control subjects (P less than .03). These results may reflect a failure in RHD or organ-specific homing of cells with the epitopes recognized by the antibodies. The presence of these cells in tonsils may be important in the immune response to streptococcal pharyngeal infection, and their absence in RHD may be involved in the unusual immune responses characteristic of this disease.

Adolescent↗
PubMed1980

Serum immunoglobulins in patients with chronic tonsillitis.

In this work, the serum immunoglobulin (IgG, IgA, IgM and IgD) levels were determined in ten patients with chronic tonsillitis. The serum immunoglobulins were estimated before and two months after tonsillectomy, using the radial immuno-diffusion method. Ten normal individuals with intact tonsils were chosen as a control group. The patients had elevated serum levels of IgG and IgA. These high levels may be due to repeated antigenic stimulation. The IgM and IgD were not significantly higher than in the normal controls. The serum IgG level did decrease significantly following tonsillectomy; the other three immunoglobulins were reduced, but insignificantly. The fall in immunoglobulins may be due to a reduction in the antigenic load, to the removal of immunoglobulin-producing tissue, or to alteration in the oropharyngeal pathogenic bacteria. Tonsillectomy does not seem to compromise immunological integrity or the immunoglobulin-producting apparatus. Estimations of the serum immunoglobulin, or simply of IgA, may help us to select those candidates for adeno-tonsillectomy who will have a good prognosis, or at least to exclude those with an underlying sub-clinical immunodeficiency disease.

Adolescent↗