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Biomedical subjects

H Korhonen

Publications and source records attributed to H Korhonen.

At least 55 records · Page 3Linked to original sources

Significance of sleeping plate as a thermal protection for farmed raccoon dogs (Nyctereutes procyonoides).

1. Both living and model animals were used to evaluate the significance of a sleeping plate as a thermal protection for the farmed raccoon dog (Nyctereutes procyonoides, Gray, 1834), its use by the animals and its cleanliness while used. 2. A dry sleeping plate effectively prevented heat loss from the model animal while a wet plate was less effective. The degree of heat transfer was highest when the plate was ice-covered. Heat loss in windy conditions was significantly higher than in calm conditions. 3. The use of a sleeping plate did not depend on ambient air temperature; in spite of the cold weather (about -25 degrees C) only one in four animals preferred to lie on plate. Animals which did not prefer to use sleeping plates most eagerly messed them up.

Animals↗

Seasonal changes in hepatic activity of G-6-phosphate and alpha-glycerophosphate dehydrogenase in farmed polecats and raccoon dogs.

Liver weight of both male and female polecats was significantly higher in winter than in summer. There were no seasonal or sex differences in the liver weight of raccoon dogs. Body weight of male polecats was highest in winter. No marked seasonal changes in body weight of female polecats, or raccoon dogs of both sexes were found. Total hepatic glucose-6-phosphate dehydrogenase activity of polecats and raccoon dogs was higher in winter than in summer. Specific activity of alpha-glycerophosphate dehydrogenase was highest in summer, but total hepatic activity did not show any seasonal changes.

Adipose Tissue↗

Seasonal changes in energy economy of farmed polecat as evaluated by body weight, food intake and behavioural strategy.

An analysis of seasonal changes in energy budget of the farmed polecat (Mustela putorius) was performed in subarctic climate. Cyclical variations were found in the body weight of male polecats from maximum values in February (2.1 kg) to minimum values in June-July (1.5 kg). There were only minor seasonal changes in the body weight of females. There was a direct relationship between body weight and voluntary energy intake on one hand (r = 0.89) and an inverse relationship between body weight and locomotor activity (r = -0.88) on the other hand. Energy intake was significantly (p less than 0.05) higher during winter (224 kcal/animal/day) than during summer (142 kcal/animal/day). Total time spent outside the nest was at its maximum during the winter months (60 min/day). The results suggest that in male polecats, changes in absolute food intake induce seasonal changes in body weight. Seasonal changes in locomotor activity seem to be less important in energy balance regulation. The fact that the body weight of females showed only minor seasonal variation supports the role of sexual hormones in the control of the body weight.

Animals↗

Ammonia levels in the whelping nests of farmed raccoon dogs and polecats.

Ammonia concentrations were measured in the nests of farmed raccoon dogs (Nyctereutes-procyonoides Gray, 1834) and polecats (Mustela putorius) at weaning time. Ammonia levels in the nests of raccoon dogs and polecats varied from 1 to 43 ppm and from 0 to 5 ppm, respectively. In the raccoon dog, with increasing litter size, the ammonia concentrations tended to increase exponentially. In the polecat, no marked relationship between litter size and ammonia levels were found. The results show that no special adaptations are required in farm life because even the highest ammonia concentrations measured were below the harmful level.

Ammonia↗

Heat loss of farmed raccoon dogs and blue foxes as evaluated by infrared thermography and body cooling.

Infrared thermographs showed that heat loss of the raccoon dog (Nyctereutes procyonoides Gray 1834) is greatest from the chest, the head, the abdomen and the feet. The blue fox (Alopex lagopus) seems to be somewhat better insulated. Mass-0.75 specific heat transfer coefficients (W/kg 0.75 per degrees C) in both species were similar. The wooden nest was able to decrease it significantly. The results support the conclusion that heat loss, and thus the energy costs, of studied species could be reduced by providing them with either a winter nest or a rest-shelf in the cage.

Animals↗

Effects of social competition for feed on growth of farmed raccoon dogs.

To test whether or not social competition influences food consumption and growth in farmed raccoon dogs (Nyctereutes procyonoides, Gray 1834), animals were placed singly, in pairs and by threes in standard cages and fed ad libitum or restricted feed portions. Daily feed intake of single, ad libitum freely fed animals, 930 +/- 150 g, was significantly more than that of animals caged in pairs (750 +/- 45 g) or by threes (730 +/- 210 g). Animals on restricted feeding consumed all the feed supplied, i.e. 550 g per animal daily. Higher feed intake was associated with a poorer apparent digestibility of protein, fat, carbohydrates and energy during the period of maximal growth rate in August. Approximately the same final body weights were achieved despite of the number of animals per cage. Animals on ad libitum feeding tended to be heavier than those of restricted feeding. However, the interindividual variation in body size was large even in single animals fed ad libitum. No significant interactions between social status and feed availability were found, i.e. the shortage of feed affected equally all social classes. No marked differences in foot length or skin quality between experimental groups were found.

Animals↗

Organ scaling in the raccoon dog Nyctereutes procyonoides gray 1834, as monitored by influences of internal and external factors.

1. Animals fed a high energy ration had bigger body weight, and bigger heart, brain and genitals then animals fed a normal diet, but they had substantially smaller liver, kidneys, adrenals and thyroid glands than the otherwise smaller animals. Restricted feeding did not necessarily produce smaller organ sizes than normal. 2. The yearly variation in organ sizes was astonishingly large whereas the sex differences were rather rare. 3. For organs like liver, kidneys and thyroid glands the conclusion from the results was independent of the method of expressing the organ mass. The organ sizes seemed to be influenced by many coexisting factors like yearly differences, sex and age of animals, feed and farm.

Animals↗

Response to cold in the blue fox and raccoon dog as evaluated by metabolism, heart rate and muscular shivering: a re-evaluation.

Oxygen consumption (ml kg-0.75/min) in relation to ambient air temperature at or below the lower critical temperature (Tlc) of the winter-furred raccoon dog (+10 degrees C) and the blue fox (-6 degrees C) is described by the equations y = 14.8-0.28x and y = 7.5-0.20x, respectively. Muscular shivering activity (integrated EMG) of both species increased below thermoneutrality parallel with increasing oxygen uptake and heart rate. Seasonal changes in measured metabolic parameters were evident for both species. The results suggest that the overall body insulation or the metabolic response to cold are not essentially worse in the raccoon dog as compared with the blue fox. It is concluded that earlier speculations of surprisingly wide thermoneutral zone and very low Tlc of the Arctic fox are not evident for the blue fox.

Animals↗

Lipogenic hepatic enzyme activity of raccoon dogs (Nyctereutes procyonoides) fed various diets.

Body weight, obesity and liver weights of male raccoon dogs fed diets of various energy content were higher than those of females. With increasing body weight and obesity the liver weight and glucose-6-phosphate dehydrogenase (G-6-PD) decreased significantly in both sexes. The liver weight correlated very positively with the G-6-PD activity. The alpha-glycerophosphate dehydrogenase (alpha-GPD) correlated with the liver weight only in females.

Animals↗

Growth and fur parameter variations of farmed raccoon dogs.

Growth, body composition and hair coat parameter variations were evaluated in farmed raccoon dogs (Nyctereutes procyonoides) reared in a conventional two animals -in-cage-system. Daily rate of body weight gain (BWG) of litters very significantly (p less than 0.001) correlated with their time of birth (r = 0.879); the later in spring they were born the faster they gained weight. Final body weight (FBW) of the whelps was to be predicted from their body weight (BW) in early August (r = 0.689). There was no significant correlation between litter size and FBW, BWG or daily rate of BWG. Social competition for food produced great variation in FBW of the animals; the difference between the heavier and lighter raccoon dogs within a cage averaged 1.2 kg (p less than 0.001). Except in FBW and obesity index, there was no significant differences in other parameters between these social groups. Social status within a cage explained only 3.6% of the pelt quality variation while it could explain 52% of the BW variation. Litter explained 36% of the pelt quality, whereas it could explain 4.9% of the BW variation only. Social status and litter did not show any significant two-way interactions. Pelt weight very significantly (p less than 0.001) correlated with pelt quality (r = 0.48) and mass (r = 0.55). Also mass very positively (p less than 0.001) correlated with pelt quality (r = 0.82), indicating that the subjectively estimated pelt quality, in fact, can be derived directly from its weight. We conclude that differences in growth parameters and fur characteristics are mainly produced by social and hereditary factors, respectively.

Animal Feed↗

Seasonal changes in thermoregulation of the raccoon dog (Nyctereutes procyonoides Gray 1834).

Oxygen consumption (ml X kg-0.75/min) in relation to ambient temperature (Ta) in the raccoon dog whelps at the ages of 7-9 weeks and 17-19 weeks is described by equations y = 32.9-0.69x and y = 26.2-0.49x, respectively. The corresponding equations to adults in summer and winter pelages are y = 19.6-0.46x and y = 14.5-0.32x, respectively. The cooling constant (min-1) of deceased raccoon dogs decreased exponentially with increasing body mass, while M-0.75 specific heat transfer coefficient (W X kg-0.75/degrees C) regressed linearly on body mass, y = 0.124-0.00066x. Cooling rate of deceased animals were more dependent on body mass than on pelage quality.

Animals↗

Completeness of occupational history and occurrences of work-related diseases.

The lack of complete occupational histories causes underestimates or overestimates of occupational mortality and morbidity. The problem is emphasized in cohorts with high turnover and in cross-sectional study designs. In the study of the effect of selective turnover on occupational mortality and morbidity complete occupational histories were acquired via questionnaire. The sample comprised 1 200 current and 1 800 alive former workers and the closest relatives of 450 deceased workers and was formed from three exposure-level cohorts (defined primarily according to the physical demands of the work) of 15 714 metal workers hired in 1950-1976. The occupational histories reported in the questionnaires were compared with those collected from employers' personnel records. The coverage of occupational histories was the most accurate for current and former workers with the longest duration of exposure and the least accurate for dead workers and the oldest age groups. The use of complete occupational histories and the combining of the similar levels of exposure through the lifetime produced clear differences in the occurrences of musculoskeletal, respiratory, and cardiovascular diseases between the three levels of exposure. The errors in person-years were smaller than the errors in the duration of exposure; the coverage varied from 51 to 94%. However, misclassification clearly caused cancer cases to be located in classes with too short a period of latency. About 30% of the deceased workers had reportedly entered the industry before the first follow-up year.

Adult↗

Different stages of disease, changes in heaviness of work and life cycle.

The aim of this study was to determine which age and exposure categories are the most prone to health selection. Mortality and morbidity were studied on three different exposure levels defined primarily according to the physical demands of the work, heavy (iron foundries), medium (manufacture of metal products), and light (manufacture of electrical devices). The population comprised 15 714 men hired in 1950-1976 to work in the three branches of the metal industry. A questionnaire on occupational history, morbidity, and the causes of turnover was sent to 3 450 current and former workers. The occupational histories of current and former workers were compared for changes in heaviness throughout their complete occupational histories. Occupations during a lifetime were also classified into three levels of exposure on the basis of physical demand (heavy, medium, and light). The three levels of exposure showed different patterns of changes in heaviness of the work according to age throughout the workers' complete occupational histories. Selection into and out of jobs within and between different levels of exposure seemed to be some kind of continuous process, a chain of selection. Similarly as changes in the heaviness of the work formed a chain of selection during lifetime, the workers' health also changed to form a chain through their life cycle. Hard and soft measures formed a continuum (dissatisfaction - death), and they followed each other as explanations for termination of employment. The points of inflection in age, where the measures of different stages of disease turned from soft to hard, varied according to the level of exposure. The life-table technique was used to show the turning of the measures.

Actuarial Analysis↗

Change in risk factors for coronary heart disease during 10 years of a community intervention programme (North Karelia project).

A comprehensive community based programme to control cardiovascular diseases was started in North Karelia, Finland, in 1972. Reductions in smoking, serum cholesterol concentrations, and blood pressure were among the central intermediate objectives. The effect of the programme during the 10 year period 1972-82 was evaluated by examining independent random population samples at the outset (1972) and five (1977) and 10 (1982) years later both in the programme and in a matched reference area. Over 10 000 subjects were studied in 1972 and 1977 (participation rate about 90%) and roughly 8000 subjects in 1982 (participation rate about 80%). Analyses were conducted of the estimated effect of the programme on the risk factor population means by comparing the baseline and five year and 10 year follow up results in the age range 30-59 years. The effect of the programme (net reduction in North Karelia) at 10 years among the middle aged male population was estimated to be a 28% reduction in smoking (p less than 0.001), a 3% reduction in mean serum cholesterol concentration (p less than 0.001), a 3% fall in mean systolic blood pressure (p less than 0.001), and a 1% fall in mean diastolic blood pressure (p less than 0.05). Among the female population the reductions were respectively, 14% (NS), 1% (NS), 5% (p less than 0.001), and 2% (p less than 0.05). During the first five years of the project (1972-7) the programme effectively reduced the population mean values of the major coronary risk factors. At 10 years the effects had persisted for serum cholesterol concentrations and blood pressure and were increased for smoking.

Adult↗

Thermoregulation of polecat and raccoon dog: a comparative study with stoat, mink and blue fox.

1. Oxygen consumption (ml X kg0.75 per min) in relation to ambient temperature (Ta) in the raccoon dog (Nyctereutes procyonoides), polecat (Mustela putorius), mink (Mustela vison) and stoat (Mustela erminea) is described by equations y = 14.2 - 0.23x, y = 26.3 - 0.47x, y = 26.9 - 0.33x and y = 39.0 - 1.06x, respectively. Resting metabolic rate (RMR) of blue fox (Alopex lagopus) could be measured only at thermoneutrality. 2. In polecats, calorigenic response to noradrenaline was about 40% above the RMR, while in raccoon dogs it was absent. 3. The cooling constant (per min) of deceased raccoon dogs was similar to that measured for blue fox (0.0008), but considerably higher than that measured for dog (beagle 0.0016) or polecats (0.0023-0.0031).

Animals↗

Combination of trimethoprim and methenamine hippurate in the treatment of acute urinary tract infections.

A new antimicrobial drug combination of trimethoprim and methenamine hippurate (TMP + MH) at 2 different dosages (100 + 500 mg and 200 + 1000 mg b.i.d.) was compared by a random double-blind technique with plain TMP (200 mg b.i.d.) and TMP-sulfamethoxazole combination (160 mg + 800 mg b.i.d.). Each of the 4 test groups of 40-47 patients with acute UTI was treated for 2 weeks. The successful response in the test groups varied from 91 to 98% and no statistical difference could be found between the groups. The side-effects were least common in the group treated with the lower dose of TMP-MH combination.

Acute Disease↗

Health selection among metal workers.

The objective of the present study was to determine which age and exposure categories are the most prone to health selection. Mortality and morbidity were studied on three different exposure levels, defined primarily according to the physical demands of the work: heavy level (iron foundries), medium level (manufacture of metal products), and light level (manufacture of electrical devices). The population comprised about 15,700 men employed in 1950--1976 in the three branches of the metal industry. The number of person-years of follow-up was about 215, 800. During the period 1950--1978, 1,407 deaths occurred. Occupational history, morbidity, and turnover causes were studied by means of a questionnaire sent to 3,500 current and former workers. The survival curves showed no great differences between the three exposure levels. However the heavy level had the highest degree of mortality, and the medium level the lowest. Foundry workers had the highest overall rates of disability. But, in the older age groups, the disability rates of the metal product workers were the highest. Less social selection was suggested for foundry workers than for the two other cohorts. Metal product workers seemed to be selected by both social and health factors. Young electrical workers were occupationally trained. On the other hand older workers with poor health were selected to this light level (negative health selection).

Adult↗

Health problems in a newly established fur farming area in Eastern Finland.

Health problems of newly established fur farms were defined in Kuopio Province. Three methods of data collection were used: 1) interviews with local farmers 2) authors' personal observations and 3) determination of endoparasitic infestation. Sanitation on farms were found to be rather good. The most commonly occurring diseases were urinary tract inflammations, intestinal infections and ectoparasites. However, health conditions were found to be satisfactory and most problems were of economic nature.

Animal Husbandry↗