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Biomedical subjects

K Behbehani

Publications and source records attributed to K Behbehani.

At least 37 records · Page 2Linked to original sources
PubMed1990

Association between HLA-DR antigens and rheumatoid arthritis in Arabs.

Eighty five Arab patients with classical and definite rheumatoid arthritis were typed to determine the prevalence of HLA A, B, C, and DR antigens. A significant increase in the prevalence of HLA-A10, B8, B21, and DR3 was found in comparison with a control population matched for age and sex. HLA-DR5 was significantly decreased in the patient group. The classical association of HLA-DR4 with rheumatoid arthritis could not be confirmed in the Arab patients resident in Kuwait, supporting reported observations in different ethnic groups of associations with HLA antigens other than HLA-DR4 and indicating a heterogeneous genetic susceptibility to rheumatoid arthritis.

Adult↗
PubMed1990

Agalactosyl IgG, antibodies to heat shock proteins, and acute rheumatic fever.

In rheumatoid arthritis an increased proportion of the N-linked oligosaccharides on serum IgG terminate with N-acetylglucosamine (agalactosyl IgG). It has recently been shown that group A streptococcal cell wall peptidoglycan/polysaccharide complex may be used to raise monoclonal antibodies which bind to this glycoform of IgG. Patients with rheumatoid arthritis also have increased levels of antibody to the 65 kD and 70 kD families of heat shock proteins, particularly to a bacterial (Mycobacterium bovis) homologue of heat shock protein hsp65. Streptococci must contain similar heat shock proteins. Acute rheumatic fever follows infection with group A streptococci, and these organisms might theoretically evoke antibody to heat shock proteins or changes in the levels of agalactosyl IgG, which is antigenically cross reactive with their cell walls. It is shown here that serum samples from patients with acute rheumatic fever do not differ from those from normal children by these criteria.

Acetylglucosamine↗
PubMed1990

Infectivity, reproductive capacity and distribution of Trichinella spiralis and T. pseudospiralis larvae in experimentally infected sheep.

Twelve Merino sheep were experimentally shown to be susceptible to infection with Trichinella spiralis or T. pseudospiralis by feeding on infected carcasses of mice or by oral intubation with recovered muscle larvae. The larvae recovered from the sheep showed variable tissue distribution. The diaphragm and tongue were most affected. The viability of the recovered larvae was confirmed by successful passage in mice. The reproductive capacity of T. spiralis in sheep was higher than that of T. pseudospiralis, and also higher than its reproductive capacity in C57BL/6J mice. The reproductive capacity of T. pseudospiralis in sheep at a lower dose was higher than that observed in mice. However at higher doses, it was significantly lower than that in mice. Therefore, it may be concluded that the sheep may be considered a suitable host for both species of Trichinella.

Animals↗
PubMed1990

Evaluation of quantitative measures of upper extremity speed and coordination in healthy persons and in three patient populations.

Upper extremity tracking tests have been used extensively in clinical studies in patients with neurologic disorders. We evaluated several new measures of upper extremity performance derived from step-response and phase-plane analysis techniques; both techniques are founded in automatic control theory. Using a computer-based tracking test, a visual step function stimulus was applied in 15 healthy subjects and 45 patients from multiple sclerosis, myasthenia gravis, and Parkinson disease populations. The upper extremity response of the subject was analyzed to find the reliability and discriminating power measures that quantify speed, coordination, and steadiness of the upper extremity response during the tracking task. Results show that reliability of the measures, although variable across the populations tested, is generally high (greater than 0.7). The speed and coordination measures derived from phase-plane analysis are more discriminating than the measures of step-response analysis for the populations tested. Some of the measures may be useful for monitoring patient performance, the other measures can be potentially helpful in diagnosis of the disorders.

Arm↗
PubMed1989

Echinococcus multilocularis: inhibition of murine neutrophil and macrophage chemotaxis.

Resident peritoneal neutrophils and macrophages from mice infected with 50 +/- 5 cysts of Echinococcus multilocularis were collected at 2, 4, 6, 8, 10, and 16 weeks postinfection. Their ability to respond and migrate to purified parasite larval antigens or endotoxin-activated mouse serum (EAMS) in comparison to normal peritoneal cells from uninfected mice was tested in vitro using Boyden chambers. Early in the infection, both cell types responded to the specific and nonspecific chemoattractants as the control group. However, at 8 and 10 weeks postinfection, the neutrophils and macrophages lost their response to parasite antigens but retained their ability to migrate to EAMS. Toward the 12th and 16th week postinfection, both cell types lost their ability to migrate to the specific as well as the nonspecific factors. The data presented suggest that the cellular mechanisms of recognition and chemotaxis in mice infected with alveolar hydatid cysts are impaired.

Animals↗
PubMed1989

Antibodies to a streptococcal cell wall adjuvant structure persist in patient with chronic rheumatic heart disease.

Sera from 50 patients with chronic rheumatic heart disease were analysed by an enzyme linked immunosorbent assay for the presence of antibodies to the streptococcal minimal adjuvant moiety, muramyl dipeptide (MDP). The T-cell responsiveness to this structure was also studied in vitro, using the lymphocyte transformation test. Fifty four percent of the patients possessed anti-MDP antibodies in their sera when examined 5 to 25 years after the initial rheumatic attack. Such antibodies were found only in 5 to 6% of sera from healthy controls or from patients with cardiac disease of non-rheumatic origin. There was neither antigenic nor mitogenic stimulation by MDP of the T-cells from peripheral blood of chronic rheumatic heart disease patients or controls. The results point to a lifetime persistence of anti-MDP antibodies in rheumatic fever and rheumatic heart disease. Possible mechanisms by which detectable levels of such antibodies are maintained in rheumatic heart disease are discussed.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1989

Elevated IgG antibody levels to the mycobacterial 65-kDa heat shock protein are characteristic of patients with rheumatoid arthritis.

We have previously demonstrated raised levels of IgG and IgA antibody to the mycobacterial 65-kDa heat shock protein (hsp) in the sera of patients with rheumatoid arthritis (RA). We have now attempted to determine whether this phenomenon is specific for RA, and whether it is seen only with the mycobacterial homologue of this particular hsp gene family. We therefore screened antibody levels to the mycobacterial and Escherichia coli hsp 65, and the mycobacterial, E. coli, and human hsp70, in sera from RA, systemic lupus erythematosus (SLE), tuberculosis (TB), ankylosing spondylitis (AS), Crohn's disease, and control donors. RA sera show the greatest increase in IgA binding to the mycobacterial hsp65, but no increase in IgA binding to the E. coli homologue. Similarly, only RA and TB sera show increased IgG binding to the mycobacterial hsp65, and we have shown previously that the titre is greater in RA. In contrast, the use of mycobacterial and E. coli hsp70 preparations as control bacterial hsp gene products has shown that RA patients do not differ from TB or SLE patients in their antibody binding to these proteins. Moreover, neither IgA nor IgG antibody to the human hsp70 in RA sera were higher than in TB, and the IgA binding was not higher than in SLE. These findings suggest that elevated IgG antibody levels to the mycobacterial hsp65 shows some disease specificity, and further studies with the human homologue and at the T-cell level are required.

Adult↗
PubMed1989

Performance characterization of human pitch control system: an acoustic approach.

The performance of the human pitch control system was characterized by measurement of the speed of pitch shift and pitch shift response speed (inverse of reaction time) at various initial pitch and loudness levels. Data from three nonsinger adult male subjects and one professional singer suggest a strong inverse correlation (r greater than 0.78) between initial pitch and rate of pitch rise. This study showed no significant relation between initial loudness and rate of pitch rise. Also, vocal response speed showed no significant relation with either initial pitch or loudness. However, it is suggested that pitch shift response speed might be related to the second formant frequency of the target vowel. A composite index of pitch control performance capacity was defined as the product of response speed and vocal fold contractile velocity. From experimental data, the composite index was able to reflect a distinct 74% superior performance by the professional singer (relative to the average maximum performance capacity of nonsingers). It is suggested that the product-based composite index of performance capacity can serve as a sensitive means for vocal proficiency determination.

Adult↗
PubMed1989

An association between Gc (vitamin D-binding protein) alleles and susceptibility to rheumatic fever.

Rheumatic fever is associated with exaggerated activity of B cells with massive production of antibody to the Group A streptococcus. Gc (vitamin D-binding protein) is constitutively expressed on B-cell membranes in association with membrane immunoglobulin, and could be involved in cell activation. We therefore looked for associations between the three major Gc alleles and susceptibility to rheumatic fever in a homogeneous Arab population. Patients with tuberculosis or rheumatoid arthritis and control donors, were studied in parallel. Allele frequencies in the controls, rheumatoid and tuberculosis patients were identical to those found in a previous study of normal Arab donors. However, there was a striking association between Gc2 and rheumatic fever. This allele was twice as common in these patients as in controls (p = 0.0024), and was present in 56.4% of all rheumatic fever patients.

Alleles↗
PubMed1989

Human cryptosporidiosis in the Arabian Gulf: first report of infections in children in Kuwait.

During a 3-month pilot study, we identified ten children with cryptosporidiosis; they all presented with diarrhoea, most also with fever, vomiting and dehydration. For diagnosis, the formalin-acetate concentrate of the stool, and direct smears were stained for oocysts in safranin-methylene blue (S-MB). The negative staining of oocysts in trichrome-stained specimens was indicative and was confirmed by destaining and restaining in S-MB. Constraints contributing to the absence of reports from the Arabian Gulf were the lack of awareness of Cryptosporidium sp. as a cause of diarrhoea in children, inappropriate laboratory diagnostic techniques and, possibly, the initial referral of patients to polyclinics where mild cases may go undetected. Contaminated drinking water and close contact with domestic animals are possible modes of transmission of Cryptosporidium sp. but further studies are recommended to confirm this.

Animals↗
PubMed1989

Human gnathostomiasis: infection with an immature male Gnathostoma spinigerum.

Gnathostomiasis, usually caused by larvae of Gnathostoma spinigerum, is a significant cause of morbidity in the Far East. We report a case of gnathostomiasis involving a male Thai residing in Kuwait who presented with acute pain in the right iliac fossa. A resection of the terminal ileum and cecum was performed. Microscopic examination showed a parasite in an eosinophilic abscess. The nematode was identified as an immature male G. spinigerum based on size, morphology, and distribution of cuticular spines.

Adult↗
PubMed1989

Echinococcus multilocularis: characterization of an alveolar hydatid cyst-induced amyloid enhancing factor.

Alveolar hydatid cysts, the larvae of Echinococcus multilocularis, were shown to induce the formation of an amyloid enhancing-like factor (AEF) called alveolar hydatid cyst-AEF (AHC-AEF) in the spleens of infected animals, 5 to 6 weeks post-infection. The adoptive transfer of AHC-AEF results in rapid induction and deposition of amyloid fibrils in the spleens following AgNO3 injection within 24 h. When injected concomitantly with alveolar hydatid cysts, it shortens the induction phase from 5 or 12 weeks to 1 week in C57BL/6J and A/JAX mice respectively. Preliminary characterization of this factor indicates that its bioactivity may be detected in the non-lipid moiety of spleen cell extracts and the sediment of ultracentrifugation. The factor is resistant to trypsin, pepsin, DNA-ase and RNA-ase treatments. It is sensitive to low or high pH (pH 3.0 and 9.5) and boiling. It resists freeze drying, dialysis, and storage at 4 degrees C for 2 weeks or -70 degrees C for more than a year. It may be fractionated using borate buffered saline, pH 7.4, on Sephacryl S-300 gel column. The active moiety eluted mainly in the first peak.

Amyloid↗
PubMed1988

Diagnosis of cystic hydatid disease: role of aspiration cytology.

Fine needle aspiration of mass lesions is reported in eleven patients in whom cystic hydatid disease (CHD) was not a differential diagnosis or whose serological results were negative. Aspiration was continued until no more fluid could be obtained. In five patients aspiration was done under ultrasound guidance. No sequelae were observed that could be attributed to aspiration per se. Aspirated fluid was stained with haematoxylin and eosin and giemsa or was passed through 5 micron polycarbonate filters which were then stained in the same way. The aspirated material and polycarbonate filters were also stained with trichrome which proved the best stain to demonstrate the acid-fast hooklets. Such filtration of the total volume of the aspirated material or that evacuated at operation is simple, quick, and accurate.

Adult↗
PubMed1988

Aspects of imported malaria at a district general hospital in non-endemic Kuwait, Arabian Gulf.

There is no indigenous mosquito-borne transmission of malaria in Kuwait. However, in a five year period at a district general hospital, the number of laboratory-diagnosed cases of malaria increased annually from 25 to 84, a rise of 336%. Except for two induced infections, all were imported, mainly from the Indian subcontinent. Plasmodium vivax was responsible for 87.29% of the cases; P.falciparum (12.05%), a mixed infection of P.vivax and P.falciparum (0.33%) and a case of P.ovale (0.33%) were also identified. Rapid preparation of acetone-fixed, Giemsa-stained thick blood films, a heightened awareness of the infection, examination of multiple samples of blood from patients and the general resurgence of malaria in endemic areas were some of the factors responsible for the high number of cases diagnosed. Most patients were young males and presented with clinical malaria due to P.vivax between May and October each year, an apparent seasonal peak. However, many were already resident in the country for a variable period. Patients with P.falciparum though, presented clinically within two weeks of arrival in the country. Parasite densities were calculated to monitor the progress of treatment and identify quickly any possible chloroquine-resistant P.falciparum strains. A policy of active prophylaxis is suggested to stem the tide of imported malaria.

Adolescent↗
PubMed1988

In vitro regulation by muramyl dipeptide of interferon production from peripheral blood mononuclear cells of healthy volunteers.

We investigated the effect of N-acetyl-muramyl-L-alanyl-D-isoglutamine (MDP) on interferon (IFN)-alpha and -gamma production by peripheral blood mononuclear cells from healthy subjects. MDP, on its own, was found to lack the ability to induce IFN production. However, this synthetic adjuvant was able to modulate IFN production induced by other stimuli. In cultures from a considerable number of tested donors, MDP enhanced IFN-gamma levels induced by phytohaemagglutinin. This effect was further potentiated after depleting the PBMNC cultures of their adherent cells. In contrast, MDP significantly suppressed the Sendai virus-induced IFN-alpha and this effect was reversed following adherent cell depletion. Identical regulatory effects on IFN production were exerted by the adjuvant active analogue of MDP, namely murabutide. The adjuvant inactive stereoisomer, MDP (DD) exhibited a similar enhancing effect on IFN-gamma but had a significantly lower inhibitory activity on IFN-alpha production. The potential value of this generation of immunomodulators in the treatment of viral infections and in models for studying the regulation of IFN at the molecular level is discussed.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1988

Hydatid liver disease: problems in diagnosis in the Middle East endemic area.

Imaging techniques such as ultrasound (US), liver scan and computerized tomography (CT) localize mass lesions in the liver and abdomen, and are valuable tools in the differential diagnosis of hydatid disease. However, we present two cases from Kuwait in the Middle East which demonstrate that these techniques alone are not as accurate as claimed in this geographical area. A sensitive and specific serological test is essential for a pre-operative diagnosis of hydatid disease. Discrepancies between radiological imaging and serological diagnosis are best resolved by cytology of the drained fluid and/or histopathological examination of the excised cyst. Negative serology would indicate ultrasound-guided aspiration of cyst fluid for cytological verification or enzyme immunoassay.

Aged↗