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Biomedical subjects

A Zaidi

Publications and source records attributed to A Zaidi.

69 records · Page 4Linked to original sources
PubMed1982

Hepatitis B in homosexual men: prevalence of infection and factors related to transmission.

Of 3,816 homosexual men examined in five sexually transmitted disease clinics in the United States, 6.1% had hepatitis B surface antigen, 52.4% had antibody to hepatitis B surface antigen, and 3.0% of the men who had no other indicator of infection with hepatitis B virus (HBV) had antibody to hepatitis B core antigen. The rate of seropositivity for HBV indicated by the presence of one or more of these serologic markers was 61.5%; seropositivity was significantly related to the duration of regular homosexual activity and to the number of nonsteady male sexual contacts in the four months before the patients were interviewed. Anal-genital intercourse, oral-anal intercourse, and rectal douching were significantly related to evidence of HBV infection, but oral-oral contact and oral-genital contact were not. Trauma to the rectal mucosa is a feature common to the practices that were significantly related to seropositivity for HBV.

Adolescent↗
PubMed1982

Improved radioassay for human antithyroglobulin.

Human antithyroglobulin (anti-HTg) in serum and tissue cultures can be assayed by coprecipitation with 125I-labelled human thyroglobulin (HTg). Co-precipitation of the antibody from different sera gives roughly parallel curves, so that a standard serum can be used for quantitiation of other sera. By assessing the binding of 125I-labelled HTg in antigen excess we estimate the antibody content of the standard serum to be 0.14 ng anti-HTg per ml. Shortened incubation minimizes non-specific binding of HTg to serum globulins and obviates pre-assay absorption of HTg. Radioassay for thyroglobulin antibodies in serum correlated with values obtained by solid-phase competitive-binding assay (SPCB). One unit in our assay corresponds to 0.014 unit by the latter assay and to 0.12 units of MRC. Research Standard A. We confirm that serum thyroglobulin seriously interferes with SPCB assay, giving what appears to be positive results for anti-HTg where none is detected with our assay. Values for anti-HTg are depressed by serum HTg but only in the presence of very high concentrations in serum.

Antibodies↗
PubMed1981

Urethritis in women attending an STD clinic.

Of an unselected group of 159 women attending a sexually transmitted diseases (STD) clinic 20% (32) had symptoms of urethritis. A positive correlation existed between the finding of more than 10 polymorphonuclear leucocytes (PMNL) per high-power field in the Gram-stained urethral smear and the presence of Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis. Conversely, these organisms were rarely isolated if no PMNL were present. Fewer cultures gave positive results for these organisms if micturition had occurred less than four hours before examination. C trachomatis was recovered from the urethra or endocervix in 29/150 (19 . 3%) and from the urethra alone in six women. In contrast, N gonorrhoea was never recovered from the urethra in the absence of endocervical infection. Of the 159 women 10% had bacteriuria due to non-sexually transmissible agents; 50% had asymptomatic bacteriuria. All, however, had other urethral pathogens isolated as well. Thus, sexually transmitted disease agents are highly prevalent in women attending an STD clinic who have signs and symptoms of urethritis. As in non-gonococcal urethritis in men, C trachomatis may be an important cause of urethritis in women.

Adolescent↗
PubMed1978

Cohort study of venereal disease. I: the risk of gonorrhea transmission from infected women to men.

Reliable data on the risk of transmission of N. gonorrhoeae would enhance our understanding of the importance of host defenses against gonorrhea and would aid in the evaluation of prophylactic measures. This paper examines the risk of transmission of gonorrhea from infected female to male and the role that variables such as race, prophylaxis and amount of exposure play in the development of gonococcal urethritis. Volunteer crew members of a large naval vessel were followed prospectively as a cohort to study their risk of acquiring gonococcal infection during a four-day liberty period in the Far East. At the same time the prevalence of N. gonorrhoeae was determined in a population of females to whom the sailors were exposed. The calculated risk of transmission per exposure with an infected partner was .19 for whites and .53 for blacks. A statistically significant relationship was noted between the risk of transmission of gonorrhea and both the number of partners and the frequency of sexual intercourse. Further, the increasing infection rate with increasing numbers of exposures in men who had a single sex partner suggests that the majority of men are in fact susceptible to gonorrhea if the quantity of exposure is sufficient.

Adult↗
PubMedDate not supplied

Age-related decrease in brain synaptic membrane Ca2+-ATPase in F344/BNF1 rats.

We used Fisher 344/Brown Norway hybrid rats (F344/BNF1) to determine whether previously reported decreases in brain synaptic plasma membrane (SPM) Ca2+-ATPase activity in inbred F344 rats also occurred in the hybrids. Plasma membrane Ca2+-ATPase (PMCA) activity in SPMs from F344/BNF1 rat brains showed a progressive age-dependent decrease in Vmax from 60.9 +/- 3.7 nmol Pi/mg/min (n = 6) in 5-month rats to 32.4 +/- 3.6 nmol Pi/mg/min (n = 6) in 34-month animals, with no change in K (act) for Ca2+. Immunoreactive PMCA in SPMs also decreased by approximately 20% at 34 months, and the calmodulin (CaM) bound to membranes following extraction with EDTA also declined progressively with age. The effectiveness of CaM in stimulating PMCA activity was significantly lower when CaM was purified from the brains of old vs. young F344 rats and when CaM from 5-month rats was oxidized in vitro. These results indicate: 1) that PMCA activity in SPMs from longer lived F344/BNF1 hybrids also decreases with age; 2) that part of the reduction in PMCA activity is due to loss of PMCA from the membranes; and 3) that age-related structural changes in CaM may decrease its interaction with proteins in SPMs.

Aging↗
PubMedDate not supplied

Auxotypes and antibiotic susceptibility patterns of Neisseria gonorrhoeae from disseminated and local infections.

The arginine-hypoxanthine-uracil auxotype has been linked with the propensity of gonococci to cause disseminated infections. Gonococci recovered from 25 patients with disseminated gonococcal infections were compared with gonococci recovered from matched controls, patients with uncomplicated gonorrhea selected during the same month. Minimal inhibitory concentrations of penicillin, tetracycline, erythromycin, and ampicillin, and the nutritional requirements (auxotypes) for proline alone, arginine alone, arginine, hypoxanthine and uracil together, serine alone and cysteine-cystine (wild type) were analyzed by discriminant analysis. Significant susceptibility to penicillin characterized strains causing disseminated infection, and a proline requirement was the most common auxotype (48%) among strains isolated in Atlanta. Together the minimal inhibitory concentration of penicillin and the proline auxotype best separated the strains causing gonorrhea. The arginine-hypoxanthine-uracil auxotype was was found in only 24% of strains causing disseminated infections. A trait other than auxotype must determine the capacity of the organisms to disseminate.

Adult↗
PubMedDate not supplied

Sensitivity and specificity of diagnostic tests for genital infection with herpesvirus hominis.

Three smear techniques for diagnosis of Herpesvirus hominis infection were evaluated by study of 168 unselected patients with genital lesions attending a venereal disease clinic. A tissue culture and results of three smear techniques were obtained for each patient in random order. H. hominis was recovered from 101 patients (60%). All three smear tests (immunofluorescence, Papanicolaou, and crystal violet) were highly specific, but the sensitivity of each was smaller than or equal to 40% among patients who had ulcerative lesions. Because H. hominis is a common cause of genital lesions and the clinical manifestations of disease are highly variable, future research must identify accurate diagnostic aids that are suitable for clinic use.

Blister↗
PubMedDate not supplied

Cefoxitin vs. penicillin in the treatment of uncomplicated gonorrhea.

Four hundred six men and women with gonorrhea were randomly assigned to receive either 2 g of cefoxitin or 4.8 X 10(6) units of aqueous procaine penicillin G intramuscularly. All patients also received 1 g of probenecid orally. There was no statistically significant difference in the failure rate between patients treated with penicillin (4.3%) and those treated with cefoxitin (5.1%). Twelve (92%) of 13 homosexual men with gonococcal proctitis who received penicillin and 19 (95%) of 20 who received cefoxitin were cured. Adverse reactions were infrequent and mild in the cefoxitin-treated group. Three patients who received penicillin developed reactions consistent with procaine toxicity. It is concluded that cefoxitin is a safe and effective alternative to penicillin for treating uncomplicated anogenital gonorrhea in men and women.

Adult↗
PubMedDate not supplied

Factors contributing to the emergence of Escherichia coli O157 in Africa.

In 1992, a large outbreak of bloody diarrhea caused by Escherichia coli O157 infections occurred in southern Africa. In Swaziland, 40,912 physician visits for diarrhea in persons ages >5 years were reported during October through November 1992. This was a sevenfold increase over the same period during 1990-91. The attack rate was 42% among 778 residents we surveyed. Female gender and consuming beef and untreated water were significant risks for illness. E. coli O157:NM was recovered from seven affected foci in Swaziland and South Africa; 27 of 31 patient and environmental isolates had indistinguishable pulsed-field gel electrophoresis patterns. Compared with previous years, a fivefold increase in cattle deaths occurred in October 1992. The first heavy rains fell that same month (36 mm), following 3 months of drought. Drought, carriage of E. coli O157 by cattle, and heavy rains with contamination of surface water appear to be important factors contributing to this outbreak.

Africa, Southern↗
PubMedDate not supplied

Survival analyses of breast cancer patients--the Shaukat Khanum Memorial experience.

Seven hundred subjects with breast cancer malignancies were followed up in time from December 1994 to December 2002 to determine survival distributions between sub-groups of breast cancer patients who had undergone surgical resection of the tumor followed by adjuvant treatment. Tumor size, nodal status, and Estrogen Receptor (ER) status at the time of presentation were ascertained. Tumors were classified according to the TNM system of the American Joint Committee on Cancer (AJCC), sixth edition, and grouped into T1/T2 and T3/T4; lymph nodes were categorized as N0 (node-negative) and N1, N2, and N3 combined (node-positive). The endpoint of interest for disease-free survival was relapse, and for overall survival, it was death. The Wilcoxon statistics for testing the equality of disease-free survival distributions between groups of patients with tumor size greater than 5 versus less than or equal to 5 cm, node-positive versus node-negative, and ER-positive versus ER-negative were found to be statistically significant (p < 0.05). For overall survival, substantial differences were found between groups of patients stratified according to tumor diameter and nodal involvement, but none for ER status.

Adult↗