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Biomedical subjects

H R Rezai

Publications and source records attributed to H R Rezai.

At least 19 recordsLinked to original sources
PubMed1988

Effect of levamisole on the course of experimental leishmaniasis in guinea-pigs and mice: haematological and immunological findings.

The effects of levamisole on the course of Leishmania enriettii infection in guinea-pigs and L. major in mice were investigated. It was demonstrated that levamisole-treated guinea-pigs either did not develop an ulcerative lesion or developed a much smaller lesion than untreated animals. Moreover, metastases which are commonly produced in approximately 50% of animals receiving 2 x 10(6) L. enriettii did not occur in levamisole-treated guinea-pigs. Leishmania enriettii infection usually causes leukopenia and eosinophilia in guinea-pigs approximately two to three weeks after infection. These haematological changes did not occur in animals receiving levamisole. The percentage of rosette T-cells which diminished in the L. enriettii infection was normalized in the group of levamisole-treated and infected guinea-pigs. The severity of Leishmania infection in mice receiving levamisole was lower in comparison to a control group of the animals.

Animals↗
PubMed1987

Detection of Leishmania donovani soluble antigen and antibody in the urine of visceral leishmaniasis patients.

Urine samples from 21 patients with visceral leishmaniasis were examined for the presence of Leishmania donovani soluble antigen and antibody by double counter-current immunoelectrophoresis. 19 samples revealed both antigen and antibody (IgM in 5 and IgG in all samples). 2 urine samples collected 10 and 13 days after Glucantime treatment revealed only antibody (IgG), not soluble antigen.

Animals↗
PubMed1987

Effect of levamisole on binding of immune complex to mouse peritoneal macrophages.

Levamisole at the concentrations of 240 and 500 micrograms/ml increased DNA-anti-DNA immune complex (IC) binding to thioglycollate-stimulated mouse (CBA) peritoneal macrophages. Reduced IC binding by macrophages of (NZB/NZW)F1 a mouse model for systemic lupus erythematosus occurs as a consequence of disease and was partially corrected after inclusion of levamisole into the reaction mixture in vitro. However, in vivo administration of 2.5 mg/kg of levamisole, the therapeutic dose, did not alter IC binding to CBA macrophages.

Animals↗
PubMed1984

Application of electroimmunodiffusion and crossed electroimmunodiffusion tests for the diagnosis of visceral leishmaniasis (kala-azar).

Techniques of electroimmunodiffusion (EID) and crossed electroimmunodiffusion (CEID) were applied and compared with the indirect fluorescent antibody (IFA) test for the diagnosis of visceral leishmaniasis. Results obtained by EID on 28 serum samples of proven cases of kala-azar correlated well with IFA. False-positive reactions were encountered by IFA assay among healthy controls and non-kala-azar patients. Using EID technique, species-specific antibody to L. donovani was demonstrated in all sera of kala-azar patients. CEID was less sensitive than EID as a few false-negative results were obtained with this technique. It is concluded that the EID test which is specific, sensitive and more economical could be applied for diagnosis of systemic leishmaniasis.

Antibodies↗
PubMed1983

Immunological findings in kala-azar, Iran.

Quantitation of immunoglobulins in patients with systemic leishmaniasis show a rise in IgM and IgG. Complement C3 levels in severely ill patients were very low, whereas generally within normal range in patients with uncomplicated recoveries. The cell mediated immune response of those kala-azar patients examined appeared to be depressed as measured by PHA skin tests. This depression was rapidly reversed following chemotherapy with Glucantim.

Adolescent↗
PubMed1982

Evidence for the presence of circulating immune complexes in serum and C3b and C3d on red cells of kala-azar patients.

The presence of immune complexes in serum, and the existence of immunoglobulin and complement on the surface of red blood cells of kala-azar patients was studied. IgG, C3b and C3d were detected on the surface of red cells of some of the patients by a direct anti-globulin test. PEG precipitation and platelet aggregation techniques demonstrated the existence of immune complexes in the sera of all nine patients examined. Both Leishmania antigen and anti-Leishmania antibody were detected in the PEG-precipitated immune complexes.

Antigen-Antibody Complex↗
PubMed1980

Immunity to Toxoplasma and Listeria induced by homologous and heterologous organisms.

Cross protection of animals against various organisms have been shown for many years. This type of resistance to phylogenetically unrelated organisms might be attributed to certain immunological phenomena such as non-specific macrophage activation. In this report the cross-protective effect of some organisms against Toxoplasma gondii RH strain and Listeria monocytogenes is described. Groups of mice were immunized with BCG, Toxoplasma lysate antigen, viable cysts of T. gondii Tehran strain and heat killed L. monocytogenes. Seventeen days after initial immunization, the animals were tested for delayed hypersensitivity by a skin test. The hypersensitive animals in each group were challenged with either lethal doses of T. gondii RH strain or 5 x 10(5) viable L. monocytogenes. Among the animals challenged with T. gondii, it was observed that complete protection was achieved only in those mice immunized with viable cysts of T. gondii Tehran strain. Although all other immunized mice eventually died after infection, they did show some degree of resistance as their deaths were delayed considerably as compared to non-immunized animals. In animals which were infected with 5 x 10(5) L. monocytogenes, complete resistance was observed only in BCG immunized mice. The other antigens including L. monocytogenes induced partial resistance as evidenced by their survival times and the multiplication of the bacteria in various internal organs.

Animals↗
PubMed1980

Immunological responses of L. donovani infection in mice and significance of T cell in resistance to experimental leishmaniasis.

The parasite burdens of livers and spleens of several strains of mice following infection with L. donovani were determined for a period of over 120 days. The parasite loads of the spleens and livers were correlated with the development of immunity to reinfection, footpad sensitivity and antibody titres. The strains of mice studied could be divided into two groups--those highly susceptible and those relatively non-susceptible. The antibody in the susceptible strains appeared 12 days after infection and increased thereafter. The antibody in the less susceptible strains appeared some time later and remained at the same level throughout the test period. In strains CAFl, C57B1/6 and BALB/c skin reactivity to Leishmania antigen developed at the time when the parasite burden had decreased from its peak. Skin reactivity never developed in DBA!l mice, the most highly susceptible strain, and in A/j the least susceptible strain. The development of resistance to reinfection with L. donovani following i.v. and i.p. infection was observed in C57Bl mice. Upon cell transfer from these immune animals, it was found that protective immunity was mediated through the thymus-dependent lymphocytes. Serum from immune mice was not able to confer immunity to the recipient animals.

Animals↗
PubMed1979

Studies on the effect of the anti-phagocytic agent cytochalasin B on Leishmania-macrophage interaction.

Mouse peritoneal exudate cells were cultured on coverslips in Eagle's Basal Essential Medium. The adhering cells were infected with promastigotes of three different species of Leishmania. After 8 h incubation, the macrophages were fixed and stained, and a total of one hundred cells were counted. The rates of infection of macrophages were respectively 53.5 +/- 5% for L. enriettii, 52.3 +/- 5% for L. donovani and 11.7 +/- 2% for L. tropica. When cytochalasin B at concentrations of 2.5, 5 and 10 microgram/ml and Leishmania promastigotes were added to the adhering cells at the same time, the drug did not have any effect on the uptake of the organisms by the macrophages. However, when the cells were treated for a 2-h period with the drug and then were infected with the promastigotes, only 1-2% of the cells were infected. On the other hand, when cytochalasin B-treated cells which had lost their phagocytic ability were washed and then were infected with the promastigotes, some degree of cellular infection was observed. It was concluded that infection of mouse p.e.c. by three different species of Leishmania which were used in our study was by phagocytosis rather than active penetration of the organisms into the cells. It was also of interest to note that although our outbred strain of mice gets infected easily with L. tropica, the p.e.c. of these animals phagocytosed L. tropica with least efficiency in comparison with L. donovani and L. enriettii.

Animals↗
PubMed1978

Immunological features of kala-azar.

Serum immunoglobulins, complement C3c, percentage of T and B cells, and skin reactivity to Leishmania were studied in ten cases of kala-azar. Immunoglobulin G was increased in a majority of these patients. The C3c level in two out of six patients tested was lower than normal. The percentage of T cells in peripheral blood of nine patients tested was reduced and in seven of these patients the percentage of B cells was elevated. After a full course of anti-kala-azar therapy the percentage of T and B cells remained the same in five patients studied. All the patients showed a negative skin reaction when they were tested with Leishmania antigen.

Adult↗
PubMed1977

Immunofluorescence and counter immunoelectrophoresis in the diagnosis of kala-azar.

Techniques of indirect immunofluorescence (IF) and counter current immunoelectrophoresis (CIEP) were employed and compared for the diagnosis of kala-azar among children in Fars Province of Iran. It is suggested that the diagnostic titre for kala-azar by immuno fluorescence is over 1 in 64. In fact a majority of the cases had a titre of more than 1 in 256. CIEP using soluble antigens prepared form the promastigote form of Leishmania donovani, was also applied to sera from patients with systemic leishmaniasis and other diseases. The CIEP test correlated well with the indirect immunofluorescent test. It is therefore suggested that CIEP, which is a rapid and less sophisticated test, can be applied for the diagnosis of kala-azar cases and epidemiological surveys.

Child↗
PubMed1977

Evaluation of counter immuno-electrophoresis crossed electro-immunodiffusion and agar gel diffusion for immunodiagnosis of human hydatid disease.

Techniques of counter immuno-electrophoresis (CIEP), crossed electro-immunodiffusion (CEID) and agar gel diffusion (AGD) were used for diagnosis of hydatid disease. Sera were obtained from suspected patients before surgery and the antigens used were either human hydatid fluid (HHF) or sheep hydatid fluid (SHF). Out of the 29 suspected cases, 21 were confirmed by recovering the cysts from lung (ten), liver (nine), liver and spleen (two). The experimental results showed that precipitin line(s) with CIEP were obtained with the sera of all 21 confirmed patients using HHF and of 13 using SHF. With CEID, all 19 sera tested demonstrated precipitin patterns with HHF. In the AGD test precipitin lines were obtained in the sera of 15 patients using HHF and of six using SHF. None of the sera from 22 patients suffering from illnesses other than hydatidosis or of the sera from 34 apparently normal individuals gave positive results with CIEP when either HHF or SHF was used as the source of antigen. The CIEP test correlated well with CEID. It is, therefore, suggested that CIEP, which is a rapid and less sophisticated test, can be applied for the diagnosis of hydatid disease and in epidemiological surveys.

Counterimmunoelectrophoresis↗
PubMed1976

Application of immunofluorescence to detection of antibody in Leishmania infections.

Indirect immunofluorescence was used for determination of antibody in human cases of cutaneous leishmaniasis, mice infected with Leishmania tropica and guinea pigs infected with L. enriettii. Results indicated that antibody in mice is detectable 23 days after infection with L. tropica. The antibody titre correlates well with the extent of infection. In guinea pigs infected with L. enriettii, antibody appears much faster and is detectable 12 days after infection. Here also the antibody titre increased during the course of infection until about 76 days at which time the leishmanial lesion was at its height. Guinea pigs having metastatic lesions consistently showed a high titre of antibody. In several cases of human cutaneous leishmaniasis antibody was detectable at the titre of not more than 1/128. In five cases of suspected systemic leishmaniasis antibody titre was much greater than in cutaneous leishmanial infection. Upon characterization of anti-leishmanial serum of guinea pig with DEAE-cellulose chromatography and analysis of the fractions by immunoelectrophoresis, it was found that the antibody activity detected by the indirect immunofluorescence resided in the gamma2 portion of guinea pig globulin.

Animals↗
PubMed1976

Alpha-chain disease and its association with intestinal lymphoma.

Twenty-seven intestinal lymphoma patients were studied. Abnormal alpha-chain immunoglobulin was detected in the sera of seven of these patients. The alpha-chain disease patients were from the rural areas of Southern Iran. They were of low socio-economic status and their age ranged from 15-44 years. Predominant clinical features were malabsorption, diarrhoea , abdominal pain, vomiting, and weight loss. Infiltration of mucosa of the small intestine with plasma cells and also distortion and flattening of the villi were common histopathologic characteristics of these patients. Involvement of mesenteric lymph nodes with infiltration of tumour cells was observed in a number of cases. Protein studies revealed no significant differences between the serum immunoglobulin levels of these patients and normal values. Immunoelectrophoresis using monospecific antiserum against H-chain of human IgA demonstrated the abnormal precipitin band of alpha-chain disease protein.

Adolescent↗
PubMed1975

Anti-leishmania activity of normal animal sera.

The growth inhibition activity of normal human, dog, rabbit, guinea pig, rat, sheep, cat, mouse and chicken sera was quantified against Leishmania enriettii and Leishmania tropica. The pattern of anti-L. enriettii activity of various animal sera was somewhat different from that observed in L. tropica. Against L. enriettii, mouse serum was inactive, and against L. tropica rat and mouse sera were inactive. All the other animal sera tested had growth inhibition activity on both leishmanias. This growth-inhibiting factor was found to be heat-labile, complement dependent, adsorbable by the specific organism and non-dialyzable. Only the first few subcultures of leishmania were affected by the active sera.

Adsorption↗