Parametric and Nonparametric Analyses of Repeated Ordinal Categorical Data

We compare two models for the analysis of repeated ordinal categorical data: the classical parametric model for means of scores assigned to the categories of the response variable and a nonparametric model based on relative effects derived from the marginal distribution functions of the response. An example in the field of Dentistry is used to illustrate and to compare the models. We also consider a simulation study to evaluate the type‐I error rates and the power of tests under both models in a balanced design setup. The simulation results suggest that both approaches behave similarly for equally spaced scores but may perform differently otherwise. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Effect of various supplies of vitamin B2 in the rat body on the activity of enzymes participating in the metabolism of xenobiotics

Studies on the effect of different content of vitamin B2 (alimentary deficiency, additional administration) in the rat organism on the activity of enzymes participating in the metabolism of foreign substances and on the inducing effect of phenobarbital have shown that vitamin B2 to a considerable extent controls the activity of flavin-containing enzymes participating in the metabolism of xenobiotics (D-amino acid oxidase, xanthine and aldehyde oxidases, NADH- and NADPH-reductase activity of neotetrazolium) and a number of enzymes for which flavins do not play the role of prosthetic group (esterases aldehyde and formaldehyde dehydrogenases, demethylase and hydroxylase). Different content of vitamin B2 in animal organism also influences the action of phenobarbital, an inductor of xenobiotics metabolism, and the acetanilide biotransformation rate.     

Dynamics of immunoglobulins and immunocompetent lymphocytes in guinea pigs with experimental ascariasis

The paper presents data on variations in the level of serous immunoglobulins (Ig M and Ig G classes), immunocompetent T- and B-lymphocytes in lymphoid organs (spleen, mesenteric, portal and mediastinal lymph nodes) and specific antiparasitic antibodies in guinea pigs during the dynamics of experimental ascariasis.     

Effect of the cytoplasm of irradiated cells on chromatin degradation in mouse thymocytes and hepatocytes

The addition of a cytoplasmic fraction, isolated from cells 3h after irradiation of mice, to exposed or intact thymocyte nuclei causes a 2- or 3-fold acceleration of chromatin degradation in the nuclei incubated in conditions optimum for activity of Ca2+,Mg2+-dependent endonuclease to be manifest. In contrast to thymocytes, no chromatin degradation products are found in liver cells of irradiated mice. The cytoplasmic fraction isolated from hepatocytes of irradiated animals fails to activate chromatin degradation in thymocyte nuclei.     

The effect of repeated administration of insulin on pain threshold and gamma-aminobutyric acid level in mouse brain

In experiments on male Albino-Swiss mice weighing 18-22 g insulin given in doses of 2 i.u./kg caused no change in the time of reaction to pain, while the same dose administered daily for 7 days potentiated the analgesic action of morphine (3 mg/kg s.c.). Glucose caused no change in this effect of insulin. After 14 days of insulin treatment the time of reaction to pain in the animals subjected to the action of morphine returned to its initial value. Twenty-four hours after the last administration of morphine the level of gamma-aminobutyric acid (GABA) was found to be decreased in the animals receiving insulin with glucose. These results suggest that the central action of insulin is dependent not only on hypoglycaemia produced by it, but may be due also to its direct action on the central structures and an indirect action mediated by its effect on other neurotransmitter systems.     

Role of motor activity in the development of hypothyroid rat pups

Studies have been made on the role of the thyroid in the development of rats. In the first group of experiments, newborn rat received within a month mercazolyl which inhibits the activity of the thyroid; in animals of the second group, mercazolyl injections were combined with cold exposures which stimulated motor activity in animals. It was found that hypothyroid rats in both groups exhibit retardation of growth as compared to normal animals. However, retardation is less significant in animals of the second group, as it is indicated by smaller changes in the protein content and total mass of skeletal muscles.     

Selective regeneration ofBacillus subtilis protoplasts transformed to kanamycin resistance

An HTY medium osmotically stabilized with 0.5 M D-glucitol was used for regeneration ofBacillus subtilis protoplasts. The application of glucitol as osmotic stabilizer allows simultaneous selection of cells resistant to kanamycin to be made since this antibiotic is not inactivated by glucitol when added to the regeneration medium.     

Spontaneous mutation of the H-2b-haplotype in C57BL/10SnY mice

A new spontaneous mutation of the H-2b haplotype was found in skin graft tests with BC3 mice derived from B10.R111 (71NS) and C57BL/10SnY outcrossing. The mutation site localized in the F1 test in the H-2Kb gene is nonidentical to and noncomplementary with bm1, bm3, bm4 mutations. The novel mutation is maintained as B10.R111-H-2bm25 strain.     

Retrospective evaluation of gynecologic cytodiagnosis. II. Interlaboratory reproducibility as shown in rescreening large consecutive samples of reported cases

Two laboratories exchanged and rescreened a large sample of cases with cervicovaginal smears they had consecutively accessioned to examine the reproducibility of gynecologic cytodiagnosis under optimum conditions. At least a "working agreement" (diagnoses within +/- 1 category on a ten-category scale) was achieved in diagnoses of normal, benign reaction and squamous abnormality (from minimal dysplasia though invasive cancer) in 18,859 cases (96.8%), of endometrial abnormality in 21 cases (42%) and of "unsatisfactory" in 99 cases (20.7%). Larger differences occurred in greater than or equal to 30% of cases except in the categories of "normal" and "benign reaction," reaching a maximum of 82% for moderate dysplasia. Reexamining 382 cases decreased disagreement by category to the 20% to 65% range only in the five categories of dysplasia plus carcinoma in situ. Agreement was not predicated on the presence of endocervical cells or squamous metaplasia; the basis for "unsatisfactory" calls was not uniform. Comparison of the laboratories' diagnoses with referee diagnoses or, on 178 cases, with tissue diagnoses also demonstrated differences in diagnostic criteria.