The antioxidant properties of tumor cell subpopulations]

A study was made of the antioxidative activity (AOA), of the activity of glytathionreductase and catalase, and of SH-group concentration in suspensions of intact cells from eight fractions of the rat ascitic ovary tumor. A correlative bond was detected between AOA, the activity of antioxidative enzymes, and SH-group concentration. It was shown that antioxidative properties of the fractions containing resting (G0) and polyploid cells were higher than those of proliferating diploid cells.     

The open-field behavior of neuroticized rats]

A detailed study has been carried out of the behaviour in the open field of the lines of rats with different functional state of the nervous system after prolonged neurotization in dependence on the phase of circadian rhythm and terms after the end of the influence. Significant changes have been shown by the amplitude of circadian rhythms of emotionality and motor activity. It is established that the reaction of the rats lines to prolonged neuroticizing action depends on the phase of the circadian rhythm, the time after its termination and on genetically determined level of excitability of the nervous system.     

Tumor spectrum, tumor latency and tumor incidence of the Pten-deficient mice

Background

Pten functionally acts as a tumor suppressor gene. Lately, tissue-specific ablation of Pten gene in mice has elucidated the role of Pten in different tumor progression models. However, a temporally controlled Pten loss in all adult tissues to examine susceptibility of various tissues to Pten-deficient tumorigenesis has not been addressed yet. Our goal was to explore the genesis of Pten-deficient malignancies in multiple tissue lineages of the adult mouse.

Methods and Findings

We utilized an inducible Cre/loxP system to delete Pten exon 5 in the systemic organs of ROSA26 (R26)-CreER^T;Pten^fx/fx mice. On reaching 45 weeks 4OHT-induced Pten loss, we found that the R26-CreER^T;Pten^fx/fx mice developed a variety of malignancies. Overall tumor mean latency was 17 weeks in the Pten-deficient mice. Interestingly, mutant females developed malignancies more quickly at 10∼11 weeks compared with a tumor latency of 21 weeks for mutant males. Lymphoma incidence (76.9% in females; 40.0% in males) was higher than the other malignancies found in the mutant mice. Mutant males developed prostate (20.0%), intestinal cancer (35.0%) and squamous cell carcinoma (10.0%), whereas the mutant females developed squamous cell carcinoma (15.4%) and endometrial cancer (46.1%) in addition to lymphomas. Furthermore, we tested the pharmacological inhibition of the PTEN downstream effectors using {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 on Pten-deficient prostate hyperplasia. Our data revealed that, indeed, the prostate hyperplasia resulting from the induced Pten loss was significantly suppressed by {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 (p = 0.007).

Conclusions

Through monitoring a variety of Pten-deficient tumor formation, our results revealed that the lymphoid lineages and the epithelium of the prostate, endometrium, intestine and epidermis are highly susceptible to tumorigenesis after the Pten gene is excised. Therefore, this R26-CreER^T; Pten^fx/fx mouse model may provide an entry point for understanding the role of Pten in the tumorigenesis of different organs and extend the search for potential therapeutic approaches to prevent Pten-deficient malignancies.     

The inhibition by the tumor necrosis factor of the death and DNA fragmentation of lymphoid cells in irradiated rats]

The influence of a tumor necrosis factor, administered 16 h before irradiation of rats, on the radiation response of thymus and bone marrow cells has been investigated. Three and 6 h after irradiation the following indices were analyzed: the number of apoptotic cells in the thymus; the accumulation of polydeoxyribonucleotides and the appearance of single-strand breaks in DNA of bone marrow and thymus cells; and the electrophoretic properties of thymocyte DNA. The injection of a tumor necrosis factor reduced the number of polydeoxyribonucleotides, inhibited internucleosome DNA fragmentation, and did not influence the formation of single-strand breaks in DNA.     

The ECoG of rats with genetic catalepsy]

Electrographic study was carried out in Wistar rats and the rats of genetical catalepsy (GC) strain. In contrast to Wistar rats epileptiform activity was observed in ECoG of GC rats being enhanced at the transition to a cataleptic state. Analysis of spectra and coherence of EEG revealed the presence of interhemispheric brain asymmetry in all the rats. In some frequency bands in GC rats inversion of interhemispheric asymmetry was found, which had been characteristic for Wistar strain. The highest interhemispheric synchronization of biopotentials was observed in the frontal cortical areas in GC rats and in the occipital areas in those of Wistar strain.     

The vasomotor action of carragenine in rats]

In the rat, carrageenan injected intravenously lowers the systemic blood pressure. This activity depends on kininogen-kinin system activation, on prostaglandin release by these kinins and on mechanic pulmonary vascular blockade. Neither histamine nor 5-hydroxytryptamine releases are observed.     

Cytomorphologic spectrum of giant cell tumor of tendon sheath

OBJECTIVE: To correlate the cytomorphologic spectrum of giant cell tumor of tendon sheath (GCTTS) with clinical and histologic findings and determine key features helpful in preoperative diagnosis. STUDY DESIGN: Retrospective analysis was done on 48 cases diagnosed cytologically over 9 years. Cases were divided into 2 groups: in group 1 cytology and histology were available (12), and in group 2 cytology alone was available (36). Cytomorphologic features were correlated with clinical and histologic findings. RESULTS: Patients ranged in age from 11 to 60 years, with more women. Small joint involvement was seen in all cases except 1, with upper limb involvement in most cases. Recurrence occurred in 3 cases. Aspiration smears in all cases showed high cellularity, multinucleated osteoclastic type of giant cells and stromal cells. Other features seen less frequently were cytoplasmic granules and vacuoles, nuclear grooves, inclusions, budding, focal mild pleomorphism, hemosiderin-laden macrophages and foam cells. Mitosis and necrosis were absent. Cytologic features were classified as constant when present in all cases and variable when present occasionally. CONCLUSION: The constant cytologic features when combined with clinical and radiologic details are sufficiently distinctive of GCTTS. Fine needle aspiration cytology can be used in early, accurate preoperative diagnosis.     

The spectrum analysis of the electromyogram: the adaptation of autoregressive models to the interference electromyogram]

Power-density spectra of interference electromyograms of M. biceps brach. and triceps brach. from two subjects were estimated by the Tukey spectral window and by autoregressive series. By fitting autoregressive models parametric represeentations of spectra are obtained. The models for the electromyograms obtained from biceps (agonist) and triceps (antagonist) differed in the length of the autoregressive series. The intra-individual variation of the spectra from three time intervals of the same contraction was relatively small.     

Importance of the role of dose rate on tumor induction in rats after radon inhalation]

Lung cancer can be induced in rats, by radon daughter products, after exposure as low as 25 WLM (80 mJ.h.m-3) protracted over 4 to 6 months with a dose rate of 100 to 150 WL (2 to 3 mJ.m-3). The incidence of lung cancer is not increased and is equal to that of controls when the same cumulated dose is protracted over 18 months at 2 WL (0.042 mJ.m-3).     

The learning characteristics of rats under free-choice conditions]

The ability to organize a four-link operant food-procuring habit in a multiple alternative maze using the free-choice method was studied in albino rats. Three types of animals were observed which were different in the character of learning. The learning curve of 20% of rats had of exponential character (type I). Some animals (37%) acquired the skill through "insight" and the process of learning in these cases could be described by a logistic regression function (type II). The remaining rats (43%) refused from solving the intricate task and were able to acquire only the simplest form of a response, i.e., running to feeders. It is suggested that learning differences between the I and II types of animals may be associated with different strategies of problem solving: "procedural" (algorithmic) and "conceptual" (semantic).     

Combinatorial relations in the EEG spectrum]

The geometric mean frequency of any EEG wave divides its frequency band B into sub-bands b and s. For the wave beta the values s, b and B are the subsequent elements of the geometric progression with denominator equals to the invariant of the gold section. A hypothesis was proposed that all the EEG waves were described by the system SG of the recurrence equations. This system was derived by the generalization of the Fibonacci generating function. Theoretical invariants Ilambda of the system and experimental ratios b/s were found to coincide with the quadratic mean error equals to 1%. The system SG predicts the existence of the EEG waves, rho and sigma (55-118, 118-225 cycles per sec.), which have not yet been discovered experimentally.     

gamma-Glutamyltranspeptidase in dimethylbenz[a]anthracene-induced mammary adenocarcinomas and in livers of tumor bearing rats

A single dose of dimethylbenz[a]anthracene (DMBA) at 20 mg/kg resulted in 100% incidence of intraductal mammary adenocarcinomas in Wistar rats, the large tumors averaging 1.87 +/- 0.45 g. gamma-Glutamyltranspeptidase activities were elevated in DMBA-induced mammary adenocarcinomas relative to lactating mammary tissue in all fractions examined: 18.8-fold in homogenates; 22.1-fold in particulate fractions; and 5.7-fold in supernatant fractions. In DMBA-induced mammary adenocarcinomas, gamma-glutamyltranspeptidase was 95% particulate, 5% supernatant, whereas in lactating mammary tissue, gamma-glutamyltranspeptidase was equally distributed between particulate and supernatant fractions. Particulate gamma-glutamyltranspeptidase from DMBA-induced mammary adenocarcinomas as well as lactating mammary tissue displayed classical Michaelis-Menten characteristics: for the adenocarcinoma enzyme Km was 2.5 nM and Vmax 200 nmol mg-1 min-1; for mammary tissue enzyme Km was 2.5 nM and Vmax 11.1 nmol X mg-1 X min-1. Both particulate enzymes were activated at 50 degrees C relative to 37 degrees C to the same extent: 1.37-fold. The activities of gamma-glutamyltranspeptidase were increased 1.8-fold in the livers of rats bearing DMBA-induced mammary adenocarcinomas relative to age-matched controls. Plasma levels of gamma-glutamyltranspeptidase were also increased 1.6-fold in tumor bearing rats. There was no observable sign of liver damage in tumor bearing rats; plasma glutamic pyruvic transaminase levels were normal in these animals. Blood glucose levels were elevated 17% in rats bearing DMBA-induced mammary adenocarcinomas compared to age-matched controls, although plasma insulin levels were the same in both groups: 35.4 +/- 3.5 microIU/ml for the former; 31.9 +/- 3.1 microIU/ml for the latter.     

The organization of instrumental food-procuring movements in rats]

The roles of the lateral hypothalamus, basolateral nucleus of the amygdalar complex, the second field of the frontal cortex, and ventromedial thalamic nucleus in organization of the fast ballistic food-procuring movements were studied in albino rats. Sequences of uni- and bilateral destruction of the brain structures were assessed by photorecording. Movement-related neuronal activity in these structures was recorded in freely moving animals. A specific involvement of each of the above listed structures in organization of food-procuring movements was shown. The lateral hypothalamus seems to participate in initiation of the motor program and its efficient realization, the basolateral amygdala appears to produce activatory, training, and stabilizing effects. The second field of the motor cortex leads in movement acquisition (i.e., in memorizing) and decision making about triggering the program. The idea about the relay role of the thalamic motor nucleus is supplemented by understanding of its more complex integrative function.     

Pancreatic enzyme spectrum in chronic stress]

In acute experiments on white male rats the enzyme spectrum of pancreas homogenate was studied in the process of 30-day adaptation after 3-hour exposure to the muscular loading (compulsory swimming in the water at a temperature of 32 +/- 1 degree C), the heat (overheating at 40-41 degrees C) and the cold (cooling at -3-4 degrees C). It was shown that the initial periods of adaptation to the factors mentioned (2d-12th day) were characterized by a considerable decrease in the activity of all the enzymes under study. With subsequent adaptation of the animal body to these stresses the enzyme activity level recovered to the initial value (18-24th day) and remained more or less stable up to the end of the experiment (30th day). It is suggested that the alteration of the pancreatic enzyme spectrum proceeds with the participation of the hypothalamic-hypophyseal-adrenal systems as a general adaptation syndrome.