Routine culture of stool specimens for Yersinia enterocolitica is not a cost-effective procedure.

Cefsulodin-Irgasin-novobiocin (CIN) agar was used to isolate Yersinia enterocolitica from 3,622 stool specimens received in our laboratory during a 1-year period. Seven specimens (0.2%) yielded Y. enterocolitica strains from a total of five patients. The low frequency of Y. enterocolitica isolation observed, coupled with the isolation of this pathogen from three of the five patients by our standard stool examination protocol, leads us to conclude that routine culture of stool specimens on CIN agar is not a cost-effective procedure.

Comparison of a new, rapid enzyme immunoassay with a latex agglutination test for qualitative detection of rubella antibodies.

A total of 450 sera were tested for rubella virus antibodies by using a new, rapid enzyme immunoassay, SUDS Rubella. The results were compared with those obtained by using the Rubascan test, a well-established latex agglutination method. The sensitivity of the SUDS Rubella was 99.5%, and the specificity was 100%, when compared with Rubascan. The SUDS Rubella test can be performed in 10 min and provides an accurate screening test for the detection of rubella antibodies.

Thyroid function and chronic hepatosplenic schistosomiasis: peripheral conversion of thyroxine to 3,5,3'-triiodothyronine and pituitary-thyroid relationship.

The relationship between chronic hepatosplenic schistosomiaisis (CHES) and circulating thyroid hormones as well as the TSH response to TRH were investigated in 41 hospitalized CHES patients and compared to those in 11 patients with non-CHES cirrhosis with severe hepatic failure. CHES patients were subdivided into 3 groups depending on the severity of parenchymal dysfunction, based upon a composite clinical and laboratory index. Angiographic and hemodynamic studies of CHES patients revealed altered hepatic arteriograms, suggesting a decreased arterial blood flow associated with an increased venous blood flow from the portal system. A significantly reduced serum concentration of total T4 (but not free T4) was only found in the cirrhotic patients. Compared to CHES groups I and II, CHES group III patients and the non-CHES cirrhotics had significantly lower mean serum T3 levels of 80 +/- 12 and 52 +/- 8 ng/dl, respectively. The serum rT3 concentration was elevated (69 +/- 6.2 ng/dl) only in the cirrhotic patients. Both basal and peak TSH levels after TRH were within the normal range for all 4 groups of patients. The basal (40.7 +/- 8.3 ng/ml) and peak (85.5 +/- 13.7 ng/ml) serum PRL levels T4-binding globulin after TRH administration were only elevated in the cirrhotic group. Although the mean T4-binding globulin values were lower in CHES group III (17.5 +/- 3.2 micrograms/ml) and in the non-CHES cirrhotic group (18.3 +/- 2.1 micrograms/ml) compared to those in groups I (21.8 +/- 2.2 micrograms/ml) and II (20.4 +/- 2.3 micrograms/ml), the differences between groups were not statistically significant. It was concluded that hemodynamic changes without parenchymal failure have little, if any, effect on the hepatic T4 5'-monodeiodination to T3, and that the low T3 and high rT3 state does not modify the pituitary secretion of TSH, presumably by a local (at the thyrotroph level) normal conversion of T4 to T3, even at very low peripheral T3 concentrations.

Triac (3,5,3'-triiodothyroacetic acid) partially inhibits the thyrotropin response to synthetic thyrotropin-releasing hormone in normal and thyroidectomized hypothyroid patients.

The effects of a daily oral dose (1.4 mg) of 3,5,3'-Triiodothyroacetic acid (Triac) on thyroid hormone levels (T4, T3 and rT3) and on the TSH and PRL responses to TRH were studied in 15 normal subjects and 5 hypothyroid patients. There were no significant changes in weight, heart rate, reflex time, or serum concentration of either cholesterol or triglycerides after 6 weeks of Triac administration. However, T4 was significantly reduced to a lower mean level (mean +/- SEM, 7.3 +/- 0.7 to 4.3 +/- 0.6 microgram/dl) in the control group. T3 and rT3 concentrations increased, possibly due to a cross-reaction with Triac in their respective RIAs. The peak TSH response to TRH in the normal subjects was 17.6 +/- 3.4 muU/ml and fell significantly to 2.0 +/- 0.8 muU/ml after Triac administration. In the hypothyroid subjects the mean serum TSH level was significantly reduced from 136 +/- 66 to 12.6, 10.5, and 11.6 muU/ml in the weeks after Triac administration. The mean peak response of both TSH and PRL after TRH (206 muU and 44.8 ng/ml, respectively) declined significantly to 63.4 muU/ml and 24 ng/ml. It was concluded that this dose of Triac partially inhibits the synthesis and secretion of TSH and PRL without any major peripheral metabolic effects.