Response perseveration in rats exposed to alcohol prenatally.

Pregnant female rats consumed liquid diets containing either 35, 17, or 0% of the total calories as ethanol. Offspring of these females were tested for spontaneous alternation at 21 days of age and for reversal learning in a T-maze shock-escape paradigm at 20--21 days of age. In the spontaneous alternation test, rats exposed to alcohol prenatally took more trials than controls to enter the goal compartment opposite to that initially entered.

[Standardization of the cytological conclusions in the diagnosis of cancer of the lung, stomach, breast and thyroid gland].

Based on a correlation of the results of cytological and histological assays in 1213 patients, the authors have analysed the correct and erroneous verifications of the cancer pattern according to cytological preparations. Under consideration are the possibilities and limitations of the cytological verification of different histological patterns and degree of differentiation of cancer of the lung, stomach, breast and thyroid. Standard cytological conclusions in accordance with the suggested cytological classifications of cancer of these organs are discussed.

[Stimulation of nonspecific resistance in mice with high- and low-molecular fractions of endotoxin on 2 models of Shigella infection].

The capacity of S. paratyphi B endotoxin and its high molecular (HMF) and low molecular (LMF) fractions to stimulate the resistance of mice to shigella infection in intraperitoneal and intranasal challenge was investigated. The HMF developed high activity after the intraperitoneal injection (efficiency index--EI = 2.

Conservation, choice, and the concurrent fixed-ratio schedule.

Five rats got all of their water in daily 60-minute sessions. Two levers and a water spout were freely available throughout baseline sessions. Contingency sessions offered a choice between two alternative fixed-ratio components, in the form of a choice between the two levers.

Choledochoduodenostomy as an adjunct to choledocholithotomy.

Choledochoduodenostomy was performed in 100 patients for calculus related disease of the common bile duct. There were no significant early or late complications of the anastomotic procedure. The 3 per cent mortality was related to antecedent advanced liver disease in two instances and, in one instance, to intra-abdominal sepsis.

[Study of the structure and function of endotoxins with the aid of enzymes. 2. Modification of Salmonella paratyphi B endotoxin with lysozyme and lipase].

Endotoxin preparations from the S. paratyphi B cultures, isolated by various methods, were treated with lysozyme (splitting of beta-1,4-glycoside links of lipid A) and lipase of the pancreas (splitting of complex ester links of glycerophosphatides). Lysozyme and, to a lesser extent, lipase, were capable of partial depression of the toxic endotoxin function.

Epinephrine absorption from retraction cord: a study in dogs.

This report re-opens the question of epinephrine absorption from gingival retraction cord during fixed prosthodontic impression procedures. The conflicting evidence exposed by this and other studies is probably related to the experimental models utilized. Some suggestions for further investigation are given.

Administrative receivership and troika management.

The authors describe the use of troika management and administrative receivership to upgrade a unit in a state mental hospital. The experiment included a three person unit chief, transitional leadership, and collective decision making.

[Rate of spontaneous chromosome aberration occurrence in cultured Chinese hamster cells].

The spontaneous chromosome mutation rate was studied in cultured aneuploid Chinese hamster cells (clone 237(1)) using the method of slowing down the rate of cell division in a limiting medium containing 0.1% of serum. It was shown that during one cell generation (which lasted 14 days in limiting medium) the accumulation of chromosome aberrations with time took place.

[Hybridization of Chinese hamster cells sensitive to ultraviolet irradiation].

Resistance to UV-light was studied in two UV-sensitive aneuploid Chinese hamster cell clones to different origin and degree of sensitivity, their respective polyploids and somatic cell hybrids. The karyotype of the parental clones, cell hybrids and polyploids was analyzed in parallel. A great variability of karyotypes was detected in hybrid cells.

[Use of Soviet semipermeable acetate-cellulose membranes for concentration and purification of typhoid antigens].

A study was made of a possibility of using Soviet made membranes "Vladipor" with a pore diameter of 16--17 nm for the purpose of concentration and purification of antigenic extracts from stab cultures of S. typhi obtained by the action of typsin, hydrogen peroxide and detergents. Preparations, complete by antigenic structure, were obtained by ultrafiltration, with a good yield.

[New principles for obtaining protective antigens from deep cutlures of enterobacteria].

A model of S. typhi submerged culture was used; application of the principle of sparing extraction of surface protective antigens by the action of sublethal concentrations of two damaging agents differing by the mechanism of inhibition of the processes of vital activity of the microorganisms was founded. The principle is based on regularities characteristic of cells of bacterial pupulations: a) nonhomogeneity of individual cells of the population by the resistance to the damaging agents, and b) independence of distribution in the population cells of resistance to different damaging agents.

[Development of spontaneous mutations in somatic mamalian cells and DNA replication. II. Expression of gene mutations in cultured cells].

The dependence of spontaneous rate and phenotypic expression of 6-mercaptopurine resistance mutations of DNA replication synthesis was studied in cultured Chinese hamster cells. Spontaneous mutations arising with a constant rate per cell per time unit independently on DNA replication rate were shown to be expressed only in the course of subsequent cell divisions. The frequency of N-nitrosomethylurea induced mutations in cells with reduced and normal DNA replication rate is approximately the same.

[Rate of the spontaneous mutation process in mammalian somatic cells and several related questions].

Various criteria are considered according to which newly arising hereditary changes in somatic mammalian cells can be classified as mutations. The analysis of experimental data reveals that the similarity of spontaneous mutation rates in somatic and germinal cells per generation, implies drastic differences in the probability of their arising per time unit: the mutation rate per time unit is considerably higher in somatic than in germ cells. This phenomenon is discussed from the viewpoint of the spontaneous mutation rate level as an adaptive character of species.