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Biomedical subjects

A Rafi

Publications and source records attributed to A Rafi.

11 recordsLinked to original sources
PubMed2003

Prevalence of vancomycin and high level aminoglycoside resistant enterococci among high-risk patients.

Enterococci have been recognized as clinically important pathogens in high-risk populations of hospitalized patients. The role of enterococci in nosocomial infections is being recognized with increasing frequency. The main source of these infections is usually fecal carriage of the microorganisms. In this study, gastrointestinal colonization with vancomycin resistant enterococci (VRE) and high-level aminoglycoside resistant enterococci among 316 high-risk hospitalized patients were investigated. One hundred and ninety-eight enterococci strains were isolated from stool specimens. All strains were identified to species level and 90 of the isolates were identified as Enterococcus faecalis (45%), 85 as E. faecium (21.5%), 14 as E. avium (7%), 7 as E. raffinosus (3.5%), 1 as E. durans (0.5%) and 1 as E. hirae (0.5%). Eleven of 198 strains were found to be moderately sensitive to vancomycin (MIC: 8-16 microg/ml) by the agar dilution method according to the National Committee for Clinical Laboratory Standards (NCCLS) recommendations, and the rest of these strains were found to be sensitive (MIC < or = 4 microg/ml). Twenty-eight strains showed high-level resistance to streptomycin (2,000 microg/ml) and 26 strains were found to have high-level resistance to gentamicin (500 microg/ml). Twelve of these strains had high-level resistance to both aminoglycosides. By the disk diffusion tests, 53 of 198 strains were found to be resistant to erythromycin, 51 to penicillin, 37 to ampicillin, 18 to ciprofloxacin, 14 to norfloxacin and 3 to nitrofurantoin. No beta-lactamase production was detected in 198 studied strains.

Aminoglycosides↗
PubMed1998

IgG response to some mycobacterial antigens in selected leprosy patients.

Serum samples from selected leprosy patients with putative tuberculosis were tested by indirect ELISA to determine the level of IgG antibody against six mycobacterial antigen preparations. PCR-positive leprosy patients were confirmed with PGL-I ELISA. A ratio of antibodies to antigens of tuberculosis and leprosy was found to be a valuable serological marker for tuberculosis in long-treated leprosy patients.

Adult↗
PubMed1997

Hyaluronate-CD44 interactions can induce murine B-cell activation.

CD44 is a widely distributed cell surface glycoprotein whose principal ligand has been identified as hyaluronic acid (HA), a major component of the extracellular matrix (ECM). Recent studies have demonstrated that activation through CD44 leads to induction of effector function in T cells and macrophages. In the current study, we investigated whether HA or monoclonal antibodies (MoAbs) against CD44 would induce a proliferative response in mouse lymphocytes. Spleen cells from normal and nude, but not severe combined immunodeficient mice, exhibited strong proliferative responsiveness to stimulation with soluble HA or anti-CD44 MoAbs. Furthermore, purified B cells, but not T cells, were found to respond to HA. HA was unable to stimulate T cells even in the presence of antigen presenting cells (APC) and was unable to act as a costimulus in the presence of mitogenic or submitogenic concentrations of anti-CD3 MoAbs. In contrast, stimulation of B cells with HA in vitro, led to B-cell differentiation as measured by production of IgM antibodies in addition to increased expression of CD44 and decreased levels of CD45R. The fact that the B cells were responding directly to HA through its binding to CD44 and not to any contaminants or endotoxins was demonstrated by the fact that F(ab)2 fragments of anti-CD44 MoAbs or soluble CD44 fusion proteins could significantly inhibit the HA-induced proliferation of B cells. Also, HA-induced proliferation of B cells was not affected by the addition of polymixin B, and B cells from lipopolysaccharide (LPS)-unresponsive C3H/HeJ strain responded strongly to stimulation with HA. Furthermore, HA, but not chondroitin-sulfate, another major component of the ECM, induced B-cell activation. It was also noted that injection of HA intraperitoneally, triggered splenic B cell proliferation in vivo. Together, the current study demonstrates that interaction between HA and CD44 can regulate murine B-cell effector functions and that such interactions may play a critical role during normal or autoimmune responsiveness of B cells.

Animals↗
PubMed1995

Application of polymerase chain reaction for the detection of Mycobacterium leprae DNA in specimens from treated leprosy patients.

In this study of leprosy patients apparently cured by dapsone monotherapy, the polymerase chain reaction (PCR), one of the most reliable and sensitive DNA-based assays, was used for the specific detection of Mycobacterium leprae DNA. Sputum and slit-skin samples from 44 such patients at Baba Baghi Leprosy Sanatorium in Iran were examined. Primers for a 530-base-pair fragment of the gene encoding the 36-kDa antigen of M. leprae were used for the study. The PCR results were compared with microscopy for acid-fast bacilli. Of the 44 sputum samples, 2 were positive by PCR (4.5%) and of the 44 slit-skin swabs taken from the same patients, 10 were PCR positive (22.7%). Only one patient was PCR positive for both sputum and slit-skin specimens (2.3%). No positive results were found by acid-fast microscopy. In total, 11 of 44 (25%) patients in this study were found to be PCR positive for M. leprae, and it was thought probable that this indicated the presence of live organisms. Particularly interesting was the statistically significant association of positive results from slit-skin swabs with paucibacillary rather than multibacillary leprosy. It is suggested that whereas relapse or immunological reaction in paucibacillary disease may result from surviving organisms, in multibacillary leprosy this may be due to re-infection.

Adult↗
PubMed1995

PCR to detect Mycobacterium tuberculosis DNA in sputum samples from treated leprosy patients with putative tuberculosis.

In this study of leprosy patients with putative tuberculosis, the polymerase chain reaction (PCR), one of the most reliable and sensitive molecular diagnostic methods, was carried out for the specific detection of Mycobacterium tuberculosis DNA. Sputum samples from 43 patients at Baba Baghi Leprosarium in Iran were tested. The DNA extraction method was based on the lysing and nuclease-inactivating properties of guanidinium thiocyanate (GuSCN) together with the nucleic acid binding properties of diatoms or silica particles. Primers for a 123-base pair (bp) fragment of the repetitive DNA sequence of M. tuberculosis were used for the PCR assay. The results of PCR were compared with direct microscopy and culture. In total, 14% of the patients in this study were found to be PCR positive for M. tuberculosis. No positive results were found by direct microscopy for acid fast bacilli (AFB) and culture. It was thought probable that the positive PCR results indicated the tuberculosis (TB) in such treated leprosy patients.

Adult↗
PubMed1990

On the origin of the elevated 17-hydroxyprogesterone levels after adrenal stimulation in hyperandrogenism.

Hyperandrogenic women appear to demonstrate an exaggerated 17-hydroxyprogesterone (17-HP) response to adrenal stimulation which is not due to the marked 21-hydroxylase deficiency of late-onset adrenal hyperplasia (LOAH). Furthermore, in hyperandrogenism the ovary also appears to secrete excessive amounts of 17-HP. It is not clear to what extent the elevated 17-HP levels after ACTH stimulation are due to extraadrenal production of the steroid. This investigation was undertaken to assess the adrenal contribution to the elevated 17-HP levels after ACTH stimulation observed in non-LOAH hyperandrogenism. One hundred and sixty consecutive unselected women with hirsutism and/or hyperandrogenic oligomenorrhea formed the clinical population. Excluded were 4 women with LOAH and all patients with hyperprolactinemia. For the purpose of investigating the relationship between adrenal response and clinical symptoms, hyperandrogenic patients were divided into 3 subgroups: hirsute only (n = 23), hirsute oligomenorrheic (n = 84), and oligomenorrheic only (n = 24). Subclassification for an additional 29 patients (18%) with hyperandrogenemia was not possible, since their symptomatology was not clearly stated in the record. However, these individuals were included in the patient group as a whole. Controls consisted of 21 healthy, regularly menstruating, nonhirsute female volunteers. Both patients and controls underwent acute adrenal stimulation with 1 mg ACTH-(1-24), and serum was obtained before and 30 min after ACTH administration. Hyperandrogenic patients had higher mean basal total testosterone (T), androstenedione (A), dehydroepiandrosterone sulfate (DHS), 17-HP, and LH/FSH levels, but not cortisol (F), compared to normal subjects (P less than 0.02). Oligomenorrheic only women had higher mean A and progesterone (P) levels than other hyperandrogenic patients (P less than 0.02). No correlation was noted between body mass index (BMI) and the levels of DHS, P, or A, while a weak positive association was noted between the BMI and the mean T (r = 0.31; P less than 0.002) and a weak negative correlation between the mean F and BMI (r = -0.21; P less than 0.05). The mean 17-HP level 30 min after ACTH administration (17-HP30) was significantly higher in hyperandrogenic women than in normal subjects whether analyzed in separate subgroups or together and was due to the higher basal 17-HP levels. Basal 17-HP correlated with the circulating levels of T, A, and P, steroids largely of ovarian origin. Alternatively, the net increment in 17-HP from 0-30 min after ACTH (delta 17-HP30) was not significantly higher in hyperandrogenic women than normal subjects and did not correlate with the basal levels of T, A, and P. Neither the basal level of 17-HP nor its response to ACTH correlated with circulating DHS levels.(ABSTRACT TRUNCATED AT 400 WORDS)

17-alpha-Hydroxyprogesterone↗
PubMed1976

[ Perfecting a simple method of organotypic thyroid gland culture in Xenopus laevis (Amphibia, Anoura)].

The larval thyroid of Xenopus cultured in an adequate medium, keeps its morphological differentiations at an ultrastructural scale and reacts against TSH added to the culture medium, through the development of apical microvilli, which is a sign of an active pinocytosis of the colloid, and also of ergastoplasmic lamellar and vesicular structures suggesting an active protein synthesis.

Animals↗
PubMedDate not supplied

Non tuberculous mycobacterium peritonitis in continuous ambulatory peritoneal dialysis.

A forty-five-year old Saudi lady who had been on Continuous Ambulatory Peritoneal Dialysis (CAPD) for three years, was admitted with a clinical picture of night fever, sweating, weight loss and turbid peritoneal fluid (PF). The PF had a high cell count, predominantly neutrophils. This condition failed to respond to a standard vancomycin-gentamycin treatment, and acid fast bacilli (AFBs) were stained from the PF. The patient was commenced on antituberculous treatment and the Tenckhoff catheter was removed. She was shifted to haemodialysis and recovered fully. Later, the AFBs were identified as a strain of mycobacterium fortuitum.

Antitubercular Agents↗