Development of an automated turbidimetric immunoassay for quantification of bovine serum immunoglobulin G

OBJECTIVE: To develop an automated turbidimetric immunoassay (TIA) for measurement of bovine IgG. SAMPLE POPULATION: 24 bovine serum samples. PROCEDURE: IgG concentration was determined by use of the TIA, and results were compared with those of the radial immunodiffusion (RID) method. Variables were determined, using commercially available reagents and a clinical biochemical analyzer. For the TIA, polyclonal goat anti-bovine IgG (Fc specific) serum, bovine IgG calibrator serum, and polyethylene glycol reaction buffer were used. Sample concentrations were determined by the instrument, using the linear regression method of least squares. The accuracy of this assay was validated by referencing to a purified bovine IgG standard and by recovery of control standards. Parallelism was documented by assay linearity and serial sample dilution linearity. Interference resulting from hemolyzed samples was examined. RESULTS: The TIA method correlated positively (r = 0.9957) and significantly (P < 0.05) with the RID method, yielding a regression equation with slope of 0.78708 and y-intercept of 1.02102. Bias attributable to hemolysis was not observed. CONCLUSIONS: The TIA method is automated, accurate, and precise for bovine serum IgG quantification. CLINICAL RELEVANCE: This assay provides sample results in approximately 10 minutes and may be used as an alternative to the manual RID method.     

Basal cell adenocarcinoma of the salivary gland. Diagnosis by fine-needle aspiration cytology

Basal cell adenocarcinoma of salivary gland is a relatively recently described neoplasm. Histopathologic features of these tumors have been published in the literature mainly in the form of case reports. This paper elaborates and describes the diagnostic fine-needle aspiration cytomorphology of two cases of basal cell adenocarcinoma of parotid gland, which, to the author's knowledge, has not been previously reported in the English literature. Fine-needle aspiration specimens in both cases contained cohesive, focally papillary, and filiform groups of neoplastic cells, which were highly reminiscent of basal cell adenoma on low power examination. Higher power, however, revealed significant cytologic atypia and mitotic activity. Differential diagnoses included basal cell adenoma, epithelial rich pleomorphic adenoma, myoepithelial lesions, small cell undifferentiated carcinoma, and metastatic carcinoma among others.     

Thirteen-year evolution of azole resistance in yeast isolates and prevalence of resistant strains carried by cancer patients at a large medical center

Drug resistance is emerging in many important microbial pathogens, including Candida albicans. We performed fungal susceptibility tests with archived isolates obtained from 1984 through 1993 and fresh clinical isolates obtained from 1994 through 1997 by testing their susceptibilities to fluconazole, ketoconazole, and miconazole and compared the results to the rate of fluconazole use. All isolates recovered prior to 1993 were susceptible to fluconazole. Within 3 years of widespread azole use, we detected resistance to all agents in this class. In order to assess the current prevalence of resistant isolates in our hematologic malignancy and transplant patients, we obtained rectal swabs from hospitalized, non-AIDS, immunocompromised patients between June 1995 and January 1996. The swabs were inoculated onto sheep's blood agar plates containing 10 microg of vancomycin and 20 microg of gentamicin/ml of agar. One hundred one yeasts were recovered from 97 patients and were tested for their susceptibilities to amphotericin B, fluconazole, flucytosine, ketoconazole, and miconazole. The susceptibility pattern was then compared to those for all clinical isolates obtained throughout the medical center. The antifungal drug histories for each patient were also assessed. The yeasts from this surveillance study were at least as susceptible as the overall hospital strains. There did not appear to be a direct linkage between prior receipt of antifungal agent therapy and carriage of a new, drug-resistant isolate. Increased resistance to newer antifungal agents has occurred at our medical center, but it is not focal to any high-risk patient population that we studied. Monitoring of susceptibility to antifungal agents appears to be necessary for optimizing clinical therapeutic decision making.     

Acculturation, alcohol consumption and AIDS-related risky sexual behavior among African American women

The present study examined the relationship between acculturation, alcohol consumption and AIDS-related risky sexual behavior in a national probability sample of 533 African American women. Results indicated that women who were the heaviest drinkers were also the least acculturated. However, women most likely to engage in risky sexual behavior, including having multiple partners, being nonmonogamous or in a nonmonogamous relationship, and being nonmonogamous or in a nonmonogamous relationship and not using a condom consistently, were high in acculturation rather than low. Alcohol use proved related to risky sexual behavior when considered in conjunction with respondents' level of acculturation. Women at risk for contracting AIDS were not low acculturated African American women who drank heavily, but high acculturated African American women. Findings from this study extend our understanding of risk and contain implications for research and prevention efforts in the area of alcohol use and AIDS-related sexual behavior among African American women.     

Effects of hypoxia on urinary organic acid and hypoxanthine excretion in fetal sheep

Severe birth asphyxia leads to a transient organic aciduria and increased hypoxanthine excretion. To investigate its origin and timing, we analyzed urine from 12 late gestation fetal sheep in utero subjected to moderately severe isocapnic hypoxia for 1 h. In six fetuses the carotid sinus nerves were cut to determine whether reflex peripheral vasoconstriction contributed to the changes in excretion. After a control period of 1 h, maternal inspired oxygen was reduced for 1 h so that fetal arterial oxygen tension fell significantly from 2.86 +/- 0.12 kPa (mean +/- SEM) to 1.55 +/- 0.04 kPa. The ewes were returned to normoxia, and monitoring was continued for 1 h. Fetal heart rate, arterial blood pressure, and femoral arterial blood flow (intact fetuses only) were recorded, and arterial pH, blood gases, and lactate were measured. Urine collected via a bladder catheter was analyzed for organic acids and hypoxanthine with gas chromatography-mass spectrometry. In intact fetuses, hypoxia increased excretion of hypoxanthine and several organic acids, notably lactic acid and intermediates of valine catabolism. Changes were apparent by 15 min, significant by 45 min, and maximal after reoxygenation. In denervated fetuses, there were small, significant, increases in organic acids and hypoxanthine by 45 min of hypoxia, but there was no surge in excretion posthypoxia. Hypoxia caused a large, significant, fall in femoral arterial blood flow in intact fetuses. We conclude that the extent of the reflex peripheral vasoconstriction, particularly in skeletal muscle, determines the amount of organic acid and hypoxanthine excretion and may explain similar biochemical disturbances after birth asphyxia. Urinary lactic acid measurement has a potential value for grading birth asphyxia.