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A simple membrane immunoassay assay system, Quik Pack, for the detection of hepatitis C virus antibody was compared with two enzyme-linked immunosorbent assays (ELISAs) in a study of 600 serum samples. Quik Pack exhibited excellent sensitivity and specificity: 96.0 and 99.7%, respectively, versus the ELISA-2 and 99.7 and 99.4%, respectively, versus the ELISA-3.

We developed a new method for determining the anti-streptolysin O (ASO) titer on the basis of a passive agglutination reaction. This new method uses Toraysphere particles sensitized with streptolysin O. This method was used to measure the ASO titer in 130 serum samples (from 31 patients with post-streptococcal glomerulonephritis, 26 patients with group A streptococcal pharyngitis, 5 patients with scarlet fever, 29 patients with non-group A streptococcal pharyngitis, 20 healthy children, and 19 healthy adults). The results were compared with those obtained simultaneously by two conventional methods, the Rantz-Randall and the NA-Latex-ASL methods. The results obtained by the Toraysphere method showed an excellent correlation with those obtained by each conventional method (correlation coefficients, 0.932 for the Rantz-Randall method and 0.913 for the NA-Latex-ASL method). The performance of each method was evaluated with respect to the clinical and microbiological diagnoses for each patient. The sensitivity, specificity, positive predictive value, and negative predictive value for the Toraysphere method were 76, 84, 81, and 79%, respectively. The corresponding values for the Rantz-Randall method were 48, 78, 67, and 62%, respectively, while those for the NA-Latex-ASL method were 60, 82, 76, and 69%, respectively. Because the Toraysphere method is simple and reproducible, has a short reaction time, and has a clear-cut endpoint for the analysis, we recommend it for routine use in determining the ASO titer in the clinical microbiology laboratory.

We evaluated the clinical utility of an rRNA amplification-based Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (AMTD) system and a PCR-based Roche AMPLICOR MYCOBACTERIUM system for direct detection of Mycobacterium tuberculosis, M. avium, and M. intracellulare. Of the 422 sputum samples from 170 patients, 137 (121 of M. tuberculosis, 14 of M. avium-M. intracellulare complex [MAC], 2 of mycobacterium other than M. tuberculosis or MAC) were culture positive with the Septi-Chek AFB system. One sample of a contaminated culture results was excluded for further analyses. The AMTD system detected all of the 121 samples which grew M. tuberculosis (sensitivity, 100%). Of the 284 culture negative samples, 28 were positive by this system (specificity, 90.1%). After resolution of the discrepant samples, based on a positive history for culture of the patient, the specificity of this system increased to 99.3%. On the other hand, the AMPLICOR system gave a positive result for 132 out of the 135 culture positive samples for M. tuberculosis or MAC (sensitivity, 97.8%). Of the 284 culture-negative samples, 37 were positive by this system (specificity, 87.0%). The specificity for this system after resolution of the discrepant samples increased to 98.9%. The agreement between the results from the AMTD system and the AMPLICOR system was 98.7%. Both of the systems are highly sensitive and specific for detecting M. tuberculosis and/or MAC directly from sputum samples within hours, and they should be recommended for routine use in the clinical microbiology laboratory.

Clinicohistopathologic and immunohistochemical studies of intrapancreatic development of duct cell carcinoma of the head of the pancreas to the body and tail were done in 34 cases in which total pancreatectomy accompanied by portal vein resection were performed from July 1981 to June 1987. In studies of hematoxylin and eosin (HE) staining, intrapancreatic development from the head to the body or tail was observed in 14 cases of 34 cases (41.1%). Multicentricity or skip development was observed in two of 14 cases. However, by using immunostaining of carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and DUPAN2, small cancer nests surrounded by dense fibrous connective tissues could be easily and accurately diagnosed, and finally, in 25 of 34 cases (73.5%), intrapancreatic continuous development from the head to body or tail was observed. The intrapancreatic development correlated with portal invasion and perineural invasion of carcinoma, hardness of body and tail, obstruction of the main pancreatic duct, and irregular pancreaticogram. The intraoperative quick immunostaining on the cryostat sections, together with HE staining, is useful to determine the intrapancreatic development of the carcinoma. The indication of total pancreatectomy or pancreatoduodenectomy for carcinoma of the head of the pancreas can be determined by these results.