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R Siboo

Publications and source records attributed to R Siboo.

At least 37 records · Page 2Linked to original sources
PubMed1987

Counterimmunoelectrophoresis using an arc 5 antigen for the rapid diagnosis of hydatidosis and comparison with the indirect hemagglutination test.

A modified counterimmunoelectrophoresis and a conventional indirect hemagglutination test were compared for routine diagnosis of human hydatid disease in an endemic area in the Middle East. Counterimmunoelectrophoresis was performed on a cellulose acetate membrane with dilutions of a commercially available antigen which interacts with sera of patients with confirmed hydatid disease to produce the arc 5 precipitin line. The test was performed with unconcentrated human sera and the lines stained in an aqueous solution of Ponceau red. Sensitivity (95.5% vs. 93.2%) and specificity (99.2% vs. 89.9%) were higher with counterimmunoelectrophoresis than with indirect hemagglutination. Cross-reactivity with sera of patients with other parasitic infections was noted with indirect hemagglutination but not with counterimmunoelectrophoresis. There was no cross-reactivity with sera of patients with autoimmune disorders by either test.

Antibodies↗
PubMed1987

HLA associations in an Arab type 1 diabetic population.

We have studied HLA-A, -B, -C, -DR, and -DQ antigen frequencies in 63 Type 1 diabetic Arab patients resident in Kuwait. Both HLA-DR3 (relative risk (RR) = 5.80) and -DR4 (RR = 2.87) showed positive associations with Type I diabetes mellitus in these patients whilst -DR2 (RR 0.16) and -DR5 (RR = 0.15) were negatively associated. The strong positive association with both HLA-DR3 and -DR4 was confirmed in Non-Gulf Arabs (RR = 12.55 and 4.29, respectively) whereas the Gulf Arabs had a significant positive association with HLA-DR3 (RR = 4.41) only. The disease was negatively associated with HLA-DR2 (RR = 0.05) in Gulf Arab patients only and with HLA-DR5 (RR = 0.10) in Non-Gulf Arabs only. HLA-DRw52 and -DRw53 were increased in Non-Gulf Arabs only (RR = 3.14 and 4.63, respectively). In both groups there was strong association with HLA-DQ3 (Gulf, RR = 28.11; Non-Gulf, RR = 6.25). Amongst HLA-A, -B, and -C loci, there was a positive association with HLA-B8 (RR = 19.06).

Diabetes Mellitus, Type 1↗
PubMed1986

Association between HLA-D region epitopes and multiple sclerosis in Arabs.

We have studied the HLA associations of MS patients in Arab patients from two regions. Those patients from the Mediterranean area showed an association of MS with HLA-DR2 (p less than 0.001) and -DQw1 (p less than 0.05), whilst in those from the Gulf there was an association with -DRw53 (p less than 0.02). In the Mediterranean patients -DRw52 was negatively associated with MS (p less than 0.05). In the control populations from the two regions there was a considerable variation in the incidence of HLA antigens. Thus, Gulf Arabs had an increased incidence of -DR1 (p less than 0.05), -DR2 (p less than 0.02), -DR6 (p less than 0.05) and decreased incidence of -DR5 (p less than 0.05), -DRw52 (p less than 0.02) and -DQw3 (p less than 0.01) compared to the Mediterranean control population. These findings are discussed in relation to the aetiology of the disease.

Alleles↗
PubMed1983

Cystolytic events and the possible role of germinal cells in metastasis in chronic alveolar hydatidosis.

Two and six week old alveolar cysts of Echinococcus multilocularis were isolated from C57BL/6J and Balb/cJ mice and used to study the cystolytic events mediated by resident inflammatory cells. Ultramicroscopic degenerative changes in these cysts were compared with the ultrastructure of in vitro grown cysts (free of inflammatory cells). Macrophages, eosinophils and neutrophils were found to bind to the laminated layer of plasma membrane of the germinal layer of cysts. Hydrolytic enzymes and eosinophil granules released extracellularly from inflammatory cells at the cyst surface appear to dissolve the laminated layer and produce gaps in the plasma membrane. Macrophages actively phagocytose the granular ground substance of the disintegrated laminated layer. Cystolysis results in the release of germinal cells which measure 6-17 microns, possess nuclei with prominent nucleoli, sparse endoplasmic reticulum, Golgi complexes and oval mitochondria. Based on histologic evidence we believe that germinal cells may be the progenitors of cysts. The possibility that germinal cells may give rise to distant metastatic foci of alveolar cysts, in immunocompromised hosts, is discussed.

Animals↗
PubMed1983

Immune complexes in experimental alveolar hydatidosis.

Increasing amounts of immune complexes (IC) accumulated in the blood of C57BL/6J (H-2b) mice infected for 16 weeks with alveolar hydatid cysts. The circulating IC were detected both quantitatively (precipitation with 3.75% polyethylene glycol) and qualitatively (Raji cell binding assay) in the sera of hydatid-mice. The levels of serum IC roughly parallel the increase in weight of the larval cyst masses (LCM) and were inversely reacted to serum compliment activity; the latter was markedly reduced at 14 weeks postinfection. The solubilized serum IC was reacted with appropriate antisera in gel precipitation test; it consisted of E. multilocularis antigens, IgGl, IgG2b, IgM and C3. Mouse IgG, IgM, complement and hydatid antigens were also detected by the indirect immunofluorescent technique in kidney sections of hydatid-mice infected 14 weeks before. The role of IC is discussed with reference to immunodepression and growth of the LCM in hydatid mice.

Animals↗
PubMed1982

Amyloidosis in experimental murine alveolar hydatidosis.

Male mice (eight to ten weeks old, C57BL/6J, H-2b strain) were inoculated intraperitoneally with 50 Echinococcus multilocularis cysts each and killed 12 and 17 weeks later. The alveolar cyst masses were weighed and the spleens and kidneys fixed for light and electron microscopy of sections. Amorphous eosinophilic deposits in both were extensive and there were apple-green birefringent deposits visible under polarized light in all the glomeruli. The presence of amyloid was confirmed by electron microscopy.

Amyloid↗
PubMed1981

Cysticercus racemosus in an eosinophilic phlegmon in the brain.

Cysticercus racemosus in a tumour-like mass from the brain of a 30-year-old Canadian was identified by histological and specific immunofluorescent techniques. The patient possibly acquired the infection during her stay in India. She had a mild peripheral eosinophilia and complained of pounding headaches and convulsions. Examination of tissue sections revealed the larva enclosed in an eosinophilic phlegmon and the surrounding brain tissue infiltrated by histiocytes and eosinophils. Loss of microtriches and degenerative changes in the larva were apparent in areas with adherent eosinophils. With the appropriate reagents, both intracellular and interstitial specific immune complexes were detected in the biopsied tissue. The course of infection in the cystic and racemosus types of cysticercosis and the role of tissue eosinophilia in neurocysticercosis have been discussed.

Adult↗
PubMed1980

Pathogenesis and host response in subcutaneous alveolar hydatidosis. I. Histogenesis of alveolar cyst and a qualitative analysis of the inflammatory infiltrates.

C57L/J male mice were infected subcutaneously in their left flank with 10 cysts of Echinococcus multilocularis. The dimensions and histologic features of the larval cyst mass (LCM) were determined at three days, at weekly intervals for 12 weeks, and at 22 weeks postinfection. The LCM doubled its size between 3 and 12 weeks, and at 22 weeks it was five times larger than at three weeks. During the proliferative phase, the LCM was infiltrated massively by neutrophils, macrophages, and progenitors of the plasma cell series. The first two cell types were found firmly bound to the laminated layer of both intact and degenerating cysts, whereas plasma cells colonized the fibrohistocytic corona and the interlacunar stroma harboring individual cysts. By 22 weeks, the proliferation of the cysts had ceased and histologically the LCM consisted of fibrous and fibrohistiocytic stroma, thick-walled fertile and sterile brood capsules, and predominantly plasmacytic and histiocytic infiltrates. In addition to exogenous budding evidence has been presented also suggesting the role of free germinal cells in the histogenesis of LCM. Regulation of cyst proliferation in susceptible hosts is discussed with reference to antibody-dependent cell mediated cytotoxicity with nonlymphoid inflammatory cells.

Animals↗
PubMed1980

Pathogenesis and host response in subcutaneous alveolar hydatidosis. II. Intense plasmacellular infiltration in the paracortex of draining lymph nodes.

Male C57L/J mice were infected subcutaneously in the left flank with 10 cysts of Echinococcus multilocularis. The draining and contralateral nodes were excised at weekly intervals, weighed, and examined histologically. Lymphoproliferation occurred in both the follicles and the paracortex (PCA) of the draining lymph nodes at one week postinfection (p.i.). Disorganization in the PCA of the draining nodes, was characterized by replacement of lymphocytes by plasma cells and the flattening of the endothelial cells lining the postcapillary venules. This began at three weeks p.i. and was completed by 12 weeks p.i. No comparable alterations occurred in the contralateral nodes during this period, but at 22 weeks p.i. these nodes were disorganized and histologically identical to the draining nodes. The growth and histogenesis of the subcutaneous alveolar cysts correlated with the expansion and disorganization of the PCA. The regulation of subcutaneous murine alveolar hydatidosis is discussed with reference to immune-deviation which is brought about by the antigenic load and plasmacellular infiltration in the draining lymph nodes.

Animals↗
PubMed1978

A fluorescent immunoassay for the quantification of C-reactive protein.

A sensitive fluorescent binding immunoassay (FBIA) was developed for measuring C-reactive protein (CRP), at a level of 20 ng/ml, in human and mouse sera. The advantages of the FBIA over radioimmunoassays are the long shelf-life of the FITC-labelled antibody, the re-use of the antibody bound microbeads, the short assay time and the use of inexpensive instruments.

Animals↗
PubMed1977

Characterization of L5178Y leukemic cells by phagocytosis, cytochemical methods, and membrane marker techniques.

Membrane marker techniques, endocytosis, and cytochemical methods were used to characterize L5178Y cells. L5178Y cells were found to have surface membrane immunoglobulin that typifies B-cells, and membrane receptors that are common to both B-cells and monocytes. L5178Y cells also have endocytic and enzymatic activities that are characteristic of monocytes. Thus L5178Y cells have the dual characteristics of B-cells and monocytes.

Animals↗
PubMed1977

Isolation of mouse C-reactive protein from liver and serum.

Purified proteins have been isolated from the sera and livers of mice. These proteins are antigenically identical but share antigenic determinants in common with human C-reactive protein and do not share antigenic determinants in common with mouse or human immunoglobulins. The proteins interact with C-polysaccharide, are precipitated by calcium ions, migrate electrophoretically with gamma mobilities, and have isoelectric points of 4.8 and 5.62. Since these properties are characteristic of C-reactive protein of man, monkey, rabbit and dog, the pure proteins isolated from mice are designated mouse C-reactive protein.

Animals↗