Clinical and functional aspects of adverse effects of toxic substance complexes in firefighters

The study covered influence of combined toxic chemicals on fire extinguishers. Acute exposure of respiratory and peripheral nervous systems was demonstrated. Consequences of the exposure were proved to include polyneuropathies, neuroses and other health disorders.     

Restriction polymorphism of the APOB locus in residents of the city of Tomsk

Restriction fragment length polymorphism (RFLP) of the apolipoprotein B locus was investigated in the population of Tomsk. The frequencies of alleles and haplotypes of polymorphic restriction sites XbaI, MspI, and EcoRI were determined. The parameters of linkage disequilibrium and polymorphism information content (PIC) were estimated. Comparative data on various regions of the world are shown.     

The effect of an original analog of the C-terminal fragment of vasopressin on the behavior of white rats

Ethinylestradiol (EE) has evident paradoxical effects on cancer risk for human breast and hepatic cancer which parallel in some respects its effects on estrogen-induced neoplasms in the hamster kidney and liver. EE has been shown to be only weakly carcinogenic in the hamster kidney, but the most potent carcinogenic estrogen in the hamster liver following prolonged treatment. Unexpectedly, when EE and potent carcinogenic estrogens, such as diethylstilbestrol (DES), 17beta-estradiol (E2) and Moxestrol (MOX), are administered concomitantly, estrogen-induced carcinogenesis in the kidney is completely prevented. In studying this novel finding, we found that, compared with E2 exposure alone, EE at 0.05 and 1.0 nM significantly (P < 0.001) inhibited the rise in proliferation of cultured primary hamster proximal renal tubular (PRT) cells in the presence of E2 (1.0 nM). Consistent with these findings, combined EE + DES treatment for 5.0 months reduced hamster kidney c-myc, c-fos and c-jun RNA expression to 43, 37 and 52%, respectively, compared with levels observed after DES treatment alone. Interestingly, TAM + DES treatment for the same period also resulted in the same low level of RNA expression of these proto-oncogenes. c-MYC, c-FOS and c-JUN protein products were comparably reduced after either EE + DES or TAM + DES treatment. It appears that c-fos expression and c-FOS protein levels in the hamster kidney were more responsive to TAM inhibition. These data demonstrate that EE possesses unique anti-tumorigenic properties in vivo in the hamster kidney. Additionally, the observed anti-estrogen-like effect of EE on cell proliferation of cultured PRT cells suggests that EE may interfere critically with estrogen receptor (ER)-mediated mitogenic pathway(s) affected by potent carcinogenic estrogens, thus preventing subsequent gene dysregulation and, hence, tumor development. Based on competition studies, the differential binding of EE to hamster kidney ER relative to that of the other estrogens (E2, DES, MOX) appears not to contribute to the prevention of estrogen carcinogenesis at this organ site by EE.     

A comparison of the hypolipidemic action of probucol at doses of 500 and 1000 mg/day in moderate hyperlipoproteinemia

AIM: Evaluation of effectiveness of hypolipidemic action of probucol in doses 500 and 1000 mg/day and comparison of probucol blood concentrations on the treatment month 3 and 6. MATERIALS AND METHODS: Probucol (Akrikhin, Russia) was given to 41 patients with primary hypercholesterolemia in a dose 500 mg/day. 3 months later the patients were divided into two groups. Group 1 patients exhibited a > 10% decrease in cholesterol levels and continued to take probucol in the dose 500 mg/day. Group 2 patients were crossed over to higher cholesterol dose--up to 1000 mg/day. Lipids levels were measured by enzyme tests, apoproteins--by immunoturbidimetry and immunodiffusion, probucol concentrations--by high-performance liquid chromatography. RESULTS: After 3 months of treatment, cholesterol lowered by 14.3 and 9.2% in groups 1 and 2, respectively. After 6 months, by 19.7 and 12.9%, respectively. Probucol concentrations in blood were higher after 6 months of treatment than after 3 months in both groups. No significant differences existed between the groups by probucol concentrations in 3 and 6 months. CONCLUSION: Hypolipidemic effect of probucol depended on the individual features of lipoproteins metabolic disorders rather than the drug blood concentration. Larger probucol doses fail to reduce cholesterol further.     

Identification of a novel endogenous memory facilitating cyclic dipeptide cyclo-prolylglycine in rat brain

Using high-performance liquid chromatography, gas-chromatography and chromato-mass spectrometry methods a novel endogenous cyclic dipeptide cyclo-prolylglycine was identified in rat brain. Its content according to gas chromatography is 2.8 +/- 0.3 nmol/g wet brain. Synthetic cyclo-prolylglycine has demonstrated antiamnesic activity in the passive avoidance test in rats at a dose of 0.1 mg/kg i.p. Cyclic dipeptide cyclo-prolylglycine seems to be a memory facilitating substance and its presence in rat brain suggests the existence of a new mechanism of memory regulation.     

Agreement between rectal and tympanic membrane temperatures in marathon runners

STUDY OBJECTIVE: To determine the agreement between rectal temperature and infrared tympanic membrane temperatures in marathon runners presenting to a field hospital at the finish line. METHODS: The subjects of this prospective, blinded, controlled study were runners 18 years or older who were triaged to the acute care medical area at the finish line for suspected hypothermia, hyperthermia, dehydration, or altered mental status. Rectal and tympanic temperatures were measured simultaneously in all subjects for whom rectal temperature measurement had been deemed necessary and recorded on separate data cards. RESULTS: Of the 239 runners treated in the acute care medical area, 37 required rectal temperature measurement and were enrolled in the study. The mean rectal temperature was 38.45 degrees +/- 1.20 degrees C (range, 35.9 degrees to 41.5 degrees C). The mean tympanic membrane temperature was 37.81 degrees +/- 95 degrees C (range, 36.3 degrees to 40.4 degrees C). Pearson's correlation coefficient revealed a moderate correlation (r = .6902, P = .00023). The mean temperature difference between the two thermometers, mean rectal minus mean tympanic membrane, was .64 degrees C (95% confidence interval, .35 degrees to .93 degrees C). Sixty-Two percent of the tympanic membrane readings were within 1 degree C of their rectal counterparts. Agreement ranged from 1.16 degrees (+2 SD) to -2.95 degrees (-2 SD). The 95% confidence interval was 1.67 degrees to -2.95 degrees C. CONCLUSION: We were able to demonstrate only a moderate correlation between the two thermometer readings, with a wide spread between the limits of agreement. This spread could be clinically significant and therefore limits the usefulness of tympanic temperature in the marathon race setting. Because of the potentially large and clinically significant differences in rectal and tympanic temperatures and the limitations inherent in our study, we cannot endorse the use of tympanic temperature in the setting of a marathon event.     

The use of alisat for correction of level of lipids and their peroxidation products in blood of patients with atherosclerosis

A simple and easy assay for plasma heparin measurement (international units/ml) is described. The method is based upon the heparin neutralization and titration by polybrene. Heparin biological activity is measured first by activated partial thromboplastin time prolongment and then by means of polybrene titration: plasma heparin concentration was evaluated in international units/ml (IU/ml). The design and properties of this method are reported. Application in clinical practice of monitoring heparinization during hemodialysis is evaluated.     

Olfaction and the homing ability of pigeons in the southeastern United States

The importance of atmospheric odors for homing pigeon navigation was tested using birds from a loft located in Savannah, GA, in the southeastern United States. When released from a familiar training site, control pigeons and pigeons given intranasal injections of zinc sulfate to produce anosmia both displayed good homeward orientation and homed quickly. When released from three unfamiliar release sites, in contrast, control birds tended to orient southeast, while zinc sulfate-treated birds were more likely to fly northwest. More importantly, while the majority of control pigeons returned to the home loft, few of the zinc sulfate-treated birds returned. The good performance of both groups from the familiar site indicates that zinc sulfate treatment does not impair the general motor ability or motivation of homing pigeons. Therefore, the observed impairment in homing success of the zinc sulfate-treated pigeons from the unfamiliar locations presumably reflects an impaired ability to use atmospheric odors to navigate home. As such, the data support the hypothesis that successful homing pigeon navigation is based on the perception of atmospheric odors and that olfactory navigation is the primary mechanism used by pigeons over a broad range of geographic areas to approximate their relative position with respect to home from unfamiliar locations.     

Hypermutability of mouse chromosome 2 during the development of x-ray-induced murine myeloid leukemia

In an effort to identify the precise role of a deletion at regions D-E of mouse chromosome 2 [del2(D-E)] during the development of radiation-induced myeloid leukemia, we conducted a serial sacrifice study in which metaphase chromosomes were examined by the G-banding technique. Such metaphase cells were collected from x-irradiated mice during the period of transformation of some of the normal hematopoietic cells to the fully developed leukemic phenotype. A group of 250 CBA/Ca male mice (10-12 weeks old) were exposed to a single dose of 2 Gy of 250-kilovolt-peak x-rays; 42 age-matched male mice served as controls. Groups of randomly selected mice were sacrificed at 20 hr, 1 week, and then at intervals of 3 months up to 24 months after x-irradiation. Slides for cytogenetic, hematological, and histological examination were prepared for each animal at each sacrifice time. An expansion of cells with lesions on one copy of chromosome 2 was evident in 20-25% of treated mice at each sacrifice time. The majority of such lesions were translocations at 2F or 2H, strongly suggesting hypermutability of these sites on mouse chromosome 2. No lesions were found in control mice. The finding leads to the possibility that genomic lesions close to 2D and 2E are aberrants associated with radiation leukemogenesis, whereas a single clone of cells with a del2(D-E) may lead directly to overt leukemia. The data also indicate that leukemic transformation arises from the cumulative effects of multiple genetic events on chromosome 2, reinforcing the thesis that multiple steps of mutation occur in the pathogenesis of cancer.