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At least 19 recordsLinked to original sources

Prevalence of HTLV-I in Arctic regions.

Sera of native inhabitants of Arctic regions were assayed for antibodies to HTLV-I by the ELISA technique followed by competition experiments to confirm antibody specificity. Residents of 7 widely separated Alaskan villages exhibited prevalence rates of 0 to 12% for HTLV-I antibodies. Less than 1% of Greenland Eskimos were HTLV-I antibody-positive. Residents of 3 northern Swedish regions ranged in HTLV-I antibody prevalence from 0 to 5%. Sera of healthy native inhabitants of Alaska and northern Sweden were similarly assayed for antibodies to HTLV-II. No additional sera were shown to be positive for HTLV-II antibodies. While some of the HTLV-I antibody-positive sera exhibited cross-reactivity with HTLV-II antigens, competition experiments using disrupted HTLV-II or purified HTLV-I p24 as test antigens indicated that the primary antibody response in all cases tested was elicited by HTLV-I. Our results show that HTLV-I distribution is not restricted to endemic areas in warm, humid climates, but extends to Arctic regions. Within these regions, HTLV-I exhibits the same restricted distribution seen in other areas where virus infection is prevalent. The Arctic does not seem to be a reservoir for HTLV-II infection. The origin of HTLV-I in Arctic areas is not known. One may speculate that foreign visitors introduced the virus into Aleut and Lapp populations, and that it has been maintained there and restricted in its distribution as a result of close familial relationships.

Adolescent↗

Auditory evoked responses in tropical men during sojourn over the arctic region.

The influence of an arctic environment on auditory evoked responses, both brainstem and cognitive, were evaluated in 10 Indian soldiers. They were first tested in Delhi and then flown to an arctic region where they were tested in the first week and again in the eighth week of their stay. Two migrants from Moscow, their usual place of residence, and six natives, born and brought up in the arctic, were also tested for comparison. The Indians, on their return to India, were tested again. The auditory evoked responses were recorded using the Nicolet (USA) Compact 4 Instrument. The Indians showed a delay in all the waves of the auditory brainstem response (ABR) during their induction in the arctic and these persisted even on their return to India whereas the migrants and the natives had relatively higher ABR latency values.

Acclimatization↗

Alterations in serum melatonin and sleep in individuals in a sub-arctic region from winter to spring.

METHODS: In a sub-arctic region at 69 degrees N, seven individuals with self-reported insomnia during the 'dark period' and seven without, were followed with repeated measures of melatonin and questioned on ten different sleep variables, from the beginning of January to the vernal equinox in March. RESULTS: The distribution of melatonin over a 24-hour period (five time points) indicated an increase in melatonin levels in both groups in the middle of January and a decrease at the time of year when the sun first rises over the horizon (23rd-24th of January). Moreover, an indication of a delayed phase shift of melatonin secretion was found during the dark period, which returned to "normal" secretion during the night at the equinox in March. Individuals with sleep problems had a slower return to "normal" melatonin secretion than those without sleep problems. A positive correlation between morning tiredness and morning levels of melatonin was found among individuals with sleep disturbances, but not in controls. CONCLUSION: This study indicates changes in the internal circadian rhythm in humans at the end of the annual dark period of winter when there is a rapid increase in the number of hours of sunlight. For vulnerable individuals, the disturbance in sleep, and in particlar morning tiredness, lasts at least until the vernal equinox in March.

Adult↗

[Effects of prophylactic vitamin administration of physical fitness of schoolchildren in the Arctic Regions].

The effectiveness of prophylactic vitamin administration to schoolchildren in the Arctic region was evaluated in the biochemical investigation of schoolchildren by the assay of vitamins C, A, E, B1, B2, B6, B12 and folic acid in their blood serum before and after "Undevitum" intake. Deficiency of a number of vitamins was detected. It was shown that regular consumption of multivitamin "Undevitum" produced a positive effect on the parameters of their physical activity, the highest effect was observed in children with the normotensive reaction to loading, and it was less expressed in those with pathological hemodynamic reactions to the loading.

Arctic Regions↗

Clinical observations on tropical men during their sojourn over the Arctic region.

In the present study, besides a detailed clinical evaluation, roentgenographic changes in cardio-respiratory system in Indian soldiers (IS) during their 60 days stay at the arctic have been observed. These results have been compared with the responses at Delhi (before cold acclimatisation) and on return to Delhi (deacclimatisation). An attempt has also been made to compare the same physiological variables with those of Russian Migrants (RM) and Russian Natives (RN) in the arctic region to review significant differences if any. Heart Rate (HR) did not show much change; there was a tendency to increase in both systolic and diastolic blood pressure; and Kerdo's index inclined towards increased sympathetic activity in IS. X-ray chest (PA View) did not show any appreciable change in the lungs in the three groups. One subject amongst IS showed cardiac enlargement and RN subjects showed prominence of pulmonary artery and pulmonary vascular markings. All these physiological changes aim at increasing the cardiac output to overcome the ill effects of cold. Pneumopathy, a clinical condition of increased pulmonary haemodynamics could have resulted in the prominence of pulmonary artery and pulmonary blood flow in the RN. Most of the physiological changes reverted to the baseline value on return to Delhi thus proving that there were no permanent changes during short stay at extreme cold conditions.

Acclimatization↗

[New data on the spread of P-41-positive strains of the rabies virus in arctic and extra-arctic regions].

271 strains of rabies virus, isolated in different regions of the former USSR, were studied with the use of monoclonal antibodies P-41 (Germany). All strains isolated in the arctic regions, as well as some of the strains isolated in nonarctic regions situated 300-1700 km south of the polar circle (the Baltic countries, Central Yakutia, the eastern part of the Transbaikal region), gave positive reaction with these antibodies. Cases of hydrophobia caused by virus with the 41 (+) marker were described. Information on the spread such strains in other parts of the world is presented.

Animals↗