T cell antigens and MHC determinants on rabbit granulocytes

A cell preparation, consisting of 90% granulocytes (polymorphonuclear leukocytes), can be obtained from the rabbit peritoneal cavity. These cells have some membrane antigens, similar to those characteristic of thymus cells (T1, T2), but they do not have the thymus antigen, RTLA. Unlike thymus cells, many polymorphonuclear leukocytes have Ia antigen, in their membranes. Heterogeneity of the cell population is indicated by differences in the number of cells affected by complement-mediated cytotoxic cell-kill with monoclonal antibodies, directed against T1 and T2 and with polyclonal antibodies directed against Ia.

Serologic diagnosis of nasopharyngeal carcinoma. A double-blind study of four EB virus antibodies with evaluation by sequential discrimination

It is generally known that a close relationship exists between Epstein-Barr Virus (EBV) and nasopharyngeal carcinoma (NPC). Recently, patients with early lesions of NPC have been detected in the general population by use of serologic mass survey. Using the double-blind method, we have studied the diagnostic value of the four EBV antibody titers, VCA-IgA, VCA-IgG, EA-IgA and EA-IgG, in four groups of subjects, each consisting of 50 persons: patients with nasopharyngeal carcinoma (NPC group), patients with cancers other than NPC in the head and neck regions (HNC group), patients with cancers outside of head and neck regions (OC group) and normal individuals (NS group). The results of these four antibodies were evaluated both singularly and together by multivariate sequential discrimination. Taking 1:10 as the criterion of being positive, in the NPC group, the positive rate of VCA-IgA is 88%, the VCA-IgG rate is 100%, the EA-IgA rate is 48% and the EA-IgG rate is 74%. In the non-NPC group, the positive rates of VCA-IgA are as high as 86%-92%, but those of the other antibodies are as low as 0-42%. The positive rates and the geometric mean titers of these four antibodies were all elevated as compared with those in the three non-NPC groups. These differences are statistically significant. VCA-IgG is unimportant in the diagnosis of NPC because of its low specificity. By treating the antibody titers of VCA-IgA, VCA-IgG, EA-IgA and EA-IgG with sequential discrimination, the correlation rate between the serology and pathology of NPC is 88% and the false positive rate is 7.3%.

Relation between geographical distribution of liver cancer and climate-aflatoxin B1 in China

This paper analyses, for the first time in China, the relationship between the data on climate (temperature and humidity) in the country, aflatoxin, hepatitis B and primary liver cancer mortality, by using the methods of geographical epidemiology and generalized factor analysis, and also approaches the characteristics of the geographical distribution of liver cancer in China from a climate-mould viewpoint. The authors come to the conclusion that climate is an important environmental condition that determines the differences in the distributions of liver cancer in different areas, and that aflatoxin B1 is one of the main carcinogenic factors of liver cancer.

[Comparative study of 3 portasystemic shunts following 65% hepatectomy in the dog. Evaluation of 2 specific functions of the liver]

Three types of porto-systemic shunt were performed in the dog following 65% hepatectomy with the aim of determining the best porto-systemic shunt for the maintenance of hepatic function during regeneration of the liver: terminolateral portocaval shunt, mesenterico-caval shunt and spleno-pancreatico-caval shunt. The hepatic functions studied were the hydroxylation of vitamin D and proaccelerin synthesis. These functions were unaffected by the mesenterico-caval shunt whilst they were depressed to the same extent by both other types of shunt.

Work in progress: treatment planning system for conformation radiotherapy

Conformation radiotherapy is a treatment technique that allows the high-dose region in the treatment field to be shaped to the prescribed treatment volume. The algorithms and software for obtaining a complete dose distribution needed to plan conformation radiotherapy for patients have been developed and implemented on the Modulex RTP system, manufactured by Computerized Medical Systems, Inc. Standard beam data, i.e., tissue-phantom ratios and off-center ratios, were used to calculate asymmetric dose profiles for the irregular field at any gantry angle. Computed dose distributions were compared with measured dose distributions and agreement was within 5% in the high-dose region.

Radioimmunoassay and plasma concentrations of the anti-allergenic agent, 2-methoxy-11-oxo-11-H-pyrido[2,1-b]quinazoline-8-carboxylic acid in man

A specific radioimmunoassay (RIA) for the determination of the antiallergenic agent, 2-methoxy-11-oxo-11H-pyrido[2,1-b]quinazoline-8-carboxylic acid (I), directly in plasma has been developed employing a rabbit antiserum to an albumin conjugate of I. The RIA has a limit of sensitivity of 0.4 ng/ml of I using a 0.1 ml sample of plasma. The intra- and interassay coefficients of variation did not exceed 6 and 9%, respectively. The specificity of the RIA was established by comparison with a less sensitive high-performance liquid chromatographic procedure and excellent agreement (r = 0.98) was observed when plasma samples were assayed by both methods. The RIA was used to determine plasma concentrations of I in man, for the first time, following oral administration of single 2, 10 and 50 mg doses of the drug.

Application of stepwise cluster analysis in medical research

A stepwise clustering algorithm, a method of multivariate statistical analysis, is suggested in this paper. The algorithm is designed for solving problems connected with stepwise regression. It is efficient not only in handling both continuous and discrete variables, but also in the nonlinear relationships between the variables. The above procedure was used in an attempt to find out the causal association of esophageal cancer with its precursors, i.e. nitrates and nitrites of nitrosamines, some of which are known to be carcinogenic. An analysis has been made of the correlation between esophageal cancer as well as severe epithelial hyperplasia of the esophagus and the concentrations of NO3- and NO2- in the drinking water. The samples used were collected from 495 wells in 49 production brigades of the Yaocun Commune in Linxian County, Honan Province. The result indicates that esophageal cancer is definitely connected with the levels of NO3- (summer) and NO2- (spring) in the drinking water. Severe epithelial hyperplasia is defintely connected with the contents of NO2- and NO3- in the drinking water collected in spring, autumn and winter. Our preliminary analysis shows that the stepwise clustering algorithm is a useful statistical method to be used for medical research.