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Nitrogen metabolism in bears: urea metabolism in summer starvation and in winter sleep and role of urinary bladder in water and nitrogen conservation.

Three bears were studied under conditions of (1) no food but access to water for 2 weeks and (2) no food or water for 3 weeks. During starvation in summer, the bears could not inhibit the net production of urea but used lean body mass; when denied access to water as well, the bears became dehydrated and azotemic. Urea was continuously formed and degraded in the winter. Arginase activity in liver increased in winter sleep; hepatic steatosis and inflammatory reactions were also noted. The urinary bladder readsorbed labeled urea and D20 in winter; the rate of absorption of urea was equal to the rate of excretion of it into the bladder. The ability to preserve lean body mass during winter sleep apparently is a special mechanism associated with the induction of winter sleep. Bears cannot duplicate this feat during summertime starvation. In winter sleep, urea is formed and degraded but the nitrogen produced is conserved in some manner that maintains the total nitrogen pool constant. The urinary bladder plays a central role in maintaining the state of winter sleep by absorbing water and solute at a rate equal to their entry into the urinary bladder.

Animals

Comparison between the thyrotropin response to thyrotropin-releasing hormone in summer and that in winter in normal subjects.

A comparison was made between the thyrotropin (TSH) response to 500 microgram thyrotropin-releasing hormone (TRH) in summer and that in winter in ten healthy normal adults living in Supporo. The serum resin triiodothyronine (T3) uptake (RT3U), thyroxine (T4) and T3 levels were also measured. While the TSH response to TRH in summer was similar to that in winter, serum T3 concentration and free T3 index were significantly higher in winter than in summer, associated with the similar values in RT3U and T4 levels in serum. Independently measured 86 specimens (43 in summer and 43 in winter) from normal adults living in the same district also showed a significant increase in serum free T3 index as well as a slight elevation of serum T3 concentration in winter but not in serum T4 level. These results indicate that the primary change in cold winter would be the stimulation of peripheral conversion of T4 to T3 rather than the activation of hypothalamo-pituitary-thyroid axis. The relevance of this interpretation was discussed.

Adult

The range of antistreptolysin-O titer among 3129 healthy individuals in winter and summer in Tehran, Iran.

A rise in ASO titre can be demonstrated in 75-80% of patients following untreated streptococcal upper respiratory infection. The difficulty, however, is that there is no such thing as normal ASO titre. The levels encountered in a given population depend upon age, geographical location, season, etc. It was, therefore, on this basis that sera were taken from 3129 healthy individuals during winter and summer in Tehran for the determination of ASO titres. Sixty-three individuals were treated both during summer and winter. During summer only 4 (6%) had titres above 250 T.U. and 59 (94%) below 250 T.U. The same individuals, when tested during the winter, showed that 7 (11%) had ASO titres above 250 T.U. and 56 (89%) below 250 T.U. This seasonal difference is statistically significant. In another study 320 individuals were tested during summer and another 394 individuals during winter. Among the summer group 31 (10%) were above 250 T.U. and 289 (90%) were below 250 T.U. In the winter group 55 (14%) were above 250 T.U. and 339 (86%) were below 250 T.U. This difference is again statistically significant. Further, 35 samples of pooled sera representing 2289 individuals were treated during the winter. Here 563 (24%) were above and 1723 (76%) were below 250 T.U. The possible sources of error in this group, in comparison with the other, are discussed.

Adolescent

Effect of winter sleep on pituitary-thyroid axis in American black bear.

During winter sleep the black bear has decreased levels of serum total and free thyroxine (T4) and triiodothyronine (T3) and a prolonged, delayed response of serum thyrotropin (TSH) (bioassay) to thyrotropin-releasing hormone (TRH). Four weeks after the end of winter sleep, levels of serum thyroid hormones increase, and TSH response to TRH is short and brisk. Serum T4 and T3 rise after TRH administration both during and after winter sleep; however, the maximum increment in serum T3 is greater during winter sleep when the TSH rise is also prolonged and exaggerated. These observations suggest that transient hypothyroidism of possible hypothalamic origin occurs in bears during winter sleep.

Animals

Antarctic wintering--over, suggestion and transient olfactory stimulation: EEG evoked potential and electrodermal responses.

EEG evoked potential and electrodermal responses to real and suggested olfactory stimulation were recorded on a team of nine men who wintered-over at Scott Base, Antarctica. Multi-variate analysis of variance findings indicated some consistent trends despite adverse conditions and marked inter-individual differences. Consistent with studies of secondary afferentation olfaction-related EEGs were evidenced in the occipital area (O1 and O2) as well as the temporal area (T3 and T4). Skin conductance (SC) showed significant responses for real and suggested odorants pre and post wintering-over. Suppression of EEG amplitudes for real and suggested stimuli was evidenced prior to wintering-over. Following wintering-over experience suppression of EEG amplitudes for real stimuli showed a decrease while suppression increased for suggested stimuli. The implications of the suggestion findings are discussed in possible explanation of the apparent conflict between different sources of information about human responses to isolation in the Antarctic environment.

Alpha Rhythm

Museum genomics links MC1R alleles to adaptive winter coat color polymorphism in the long-tailed weasel.

Understanding the architecture of biological adaptations is a major endeavor of evolutionary biology. Using Natural History collections, we study the genetic basis and evolution of white/brown winter coat color variation in the long-tailed weasel (Neogale frenata), a crucial phenological adaptation for camouflage in habitats with seasonal snow. We produced whole-genome sequencing data for museum specimens, along two winter color morph transition areas in North America, at the West and East coasts. Genome-wide association scans identified a single genomic region linked to color variation polymorphism with approximately 300 kb and 200 kb in the West and East regions, respectively, which included the pigmentation gene MC1R. We identified three MC1R alleles, two of which with deletions of nine or eight amino acids, alternatively associated with the winter brown morphs in the West and East, respectively. These deletions affect the second transmembrane domain, and in one case also the first extracellular loop, which in silico analyses predicted to impact the protein's function. Our findings show alternative intraspecific evolutionary solutions for environmental adaptation in long-tailed weasels, building on the evidence that major genes of the melanin production pathway are hotspots for recurrent and independent evolution of winter camouflage adaptation. This adaptive variation may be crucial to anchor adaptive responses facing future environmental change.

Receptor, Melanocortin, Type 1

The Spitzbergen reindeer--a winter-dormant ungulate?

Seasonal changes in serum levels of growth hormone, cortisol and thyroxine in calves and adult Spitzbergen reindeer (Rangifer tarandus platyrynchus) were measured and compared to those previously found in Norwegian reindeer (R.t. tarandus). Cortisol did not differ significantly between summer and winter, or between the subspecies. Growth hormone and thyroxine exhibited highly significant seasonal changes and subspecific differences: winter levels of growth hormone were much higher than summer levels in the Spitzbergen reindeer, while Norwegian reindeer differed very little from season to season. Both Spitzbergen and Norwegian reindeer had markedly reduced thyroxine levels during winter, but the values from the former were much lower than those from the latter. In summer, however, the levels were equal. The high levels of growth hormone and low levels of thyroxine in the Spitzbergen reindeer during winter are indicative of high lipolytic activity and a reduced metabolic rate, respectively.

Animals

The presence of gastric parasites in winter-slaughtered reindeer.

The presence of gastric parasites in winter-slaughtered calves and adult animals, was investigated. The number of parasites found was low in case of the calves indicating that gastric worms are of low significance concerning the winter losses. In case of adult animals was found a higher infestation indicating that gastric nematodes maybe of importance concerning the winter losses of 1,5 years old animals, Ostertagia leptospicularis was the only found species except for one animal in which was also present a few spiculopteragia alcis. The total dominance of Ostertagia leptospicularis means a marked difference from the findings of autumn-slaughtered reindeer bulls where Ostertagia leptospicularis was not found to be such a frequent finding but in addition several other species were found. In view of that is discussed a seasonal varation, winter ostertagiosis seems not to be a problem in reindeer calves.

Abattoirs

[Effect of plant residues on the parasitic activity of soilborne pathogens and the saprophytic microflora of the soil. III. Influence of rye and rape grown as winter catch crop on the incidence of Cercosporella herpotrichoides Fron (author's transl)].

In a five-years field trial, the influence of two winter catchcrops, rye and rape, upon the incidence of Cercosporella herpotrichoides has been studied. The winter catch-crops had been repeated three times, followed either by stubble-crop or without in fall of the fourth year. The variants (blocks) had been completed by two variants without catch-crop, either carefully cultivated or overgrown with weeds. Each of the four blocks had been divided three times to be grown with three different crop sequences containing 80%, 60% (with the insusceptible corn), or 40% haulm fruit, respectively. Each of the 12 variants had been divided into two parts by continuous fallow stripe, one part being artificially infested with the pathogen in the beginning (1st winter wheat). In the 2nd, 3rd, and 4th year, only spring crops were grown, followed by winter wheat in the 5th year. The final exploration resulted in a medium to heavy degree of infection, being significantly higher in the 80% cereal crop sequence than in the 60% and 40% sequences. Concerning the catch-crops, infection in the rye variants was equal or significantly lower than in the carefully cultivated variants without catch-crop. On the other hand, infection of the rape variants had become significantly higher than that of the catch-crop-free ones, about as heavily as in the weed-infested variants. From fall 1966 to summer 1969, the development of the saprophytic soil microflora and several other edaphic parameters had been investigated. Remarkable differences in intensity of disintegration have been observed under the influence of the main crops, cereals or potatoes, respectively, but no differences could be stated resulting from the matter of disintegration--residues of rye or rape--, which might interpret the contrasting effects on the pathogen. Too, no indication for antagonistic activity of bacteria or actinomycetes has been noted. The results are compared with known facts of Cercosporella and of other soil borne pathogens. The difference in biology of Cercosporella on the one hand, and of root infecting fungi on the other hand seems to be most important to explain the results obtained.

Actinomycetales

[The supply of wild ruminants with major and trace elements. 2. The manganese content of winter grazing and the manganese status of red deer, fallow deer, roes and mouflons].

The winter grazing of wild ruminants on mantles of slate waste in the Harz mountains and in Gera county were richest in Mn whereas those on mantles of granite waste in the Erzgebirge were poorest. The flora of the shell-limestone, keuper and loess areas contains much less Mn than that of those acid habitats. The Mn-requirement of the wild ruminants grazing in the forests is met however, since bilberry plants (2,080 mg/kg), spruce twigs (984 mg/kg), spruce bark (827 mg/kg), oak twigs (791 mg/kg) and heather (754 mg/kg dry matter) in addition to many other plant species store extremely high amounts of Mn. Solely sallow twigs were poor in Mn (28 mg/kg). Based on 601 samples examined, the Mn supply of wild ruminants is extensively described. The rumen content reflected the plentiful Mn-supply of the wild ruminants living in forests (greater than 400 mg/kg) and the far worse one of field roes, particularly in Mn-deficiency areas for domesticated ruminants (mantle of shell-limestone waste 37 mg Mn/kg dry matter of rumen content). The indicator organs of the Mn-status (liver, covering hair, kidneys) verify the statements made concerning red deer, fallow deer and mouflons, of which a total of 170 head from 14 biotopes were examined. An Mn-deficit of field roes in Mn-deficiency habitats in winter cannot completely be excluded. Mouflons have not yet been able to adapt themselves to the excessive Mn-supply of the acid forest habitats in Central Europe. They stored significantly higher amounts of Mn in liver, covering hair, kidneys, cerebrum and ribs than the other wild ruminants and sheep and cattle. The normal Mn-content of the liver and the cerebrum of red deer, fallow deer and roes corresponds to that of sheep and cattle. Roes and fallow deer have winter covering hair poor in Mn (less than 4.0 mg/kg) in comparison to sheep and cattle.

Animal Nutritional Physiological Phenomena

Winter diarrhoea and rotaviruses in Rhodesia.

In the winter fewer bacterial pathogens are isolated from patients with gastro-enteritis than in the summer. The incidence of rotavirus infection is, however, at its greatest during the winter months and the virus is rarely found in cases of gastro-enteritis which occur during the warm season. The clinical pattern in winter diarrhoea is characteristically severe and acute but there has been no mortality or cross-infection.

Bacteria

[Winter sports injuries of the urogenital tract (author's transl)].

During 1964-1974 112 injuries of the urogenital tract caused by winter sports were treated at the University Hospital Innsbruck, Department of Urology. Eighty-eight patients suffered skiing injuries, 20 tobogganing injuries, and one injury each was caused by ski jumping and bobsleighing accidents, two traumas resulted from a fall from a chair lift. On the basis of typical case reports the most common types of trauma of the urogenital tract are demonstrated and the basic mechanisms of the accidents are discussed. Particular attention is paid to the obvious increase of lesions of the external genitalia and the urethra in the last few years caused by the so-called spinning ski, as well as the frequency of kidney traumas, especially in winters with little snow. Tobogganing accidents caused injuries to the kidneys as well as to bladder and urethra. In contrast to traumas caused by skiing, tobogganing injuries were mostly multiple. Analysis of patients records shows an increase of these injuries, which were really not typical for winter sports. The possible reasons as well as their prevention are discussed.

Athletic Injuries

Retinotectal projection of the adult winter flounder (Pseudopleuronectes americanus).

The winter flounder shifts the orinetation of its body 90 degrees at metamorphosis so that its left side is functionally ventral and its right side functionally dorsal. Concomitantly the left eye migrates onto the right side. The net result of these complex metamorphic changes is that the dorsoventral axes of the visual fields are perpendicular to the body rather than parallel as in most other teleosts. The developing flatfish may provide a resource for studying the formation of neural connections, for the change in orientation may necessitate some shift in connections in visuomotor pathways. As a baseline for developmental studies, we have established the retinotectal projection in adult winter flounder by means of anatomical tracing techniques (autoradiography and degeneration staining) and electrophysiological mapping techniques. The histological pattern of retinal afferents to the tectum is similar to that of other teleosts; afferents are confined to the superficial white and gray zone, with a few fibers coursing in the deep white zone. Electrophysiological mapping shows that the visuotectal projection is complete over the entire extent of the tectum, symmetrical for right and left fields and patterned normally.

Animals

Urinary oxalate in summer and winter in normal subjects and in stone-forming patients with idiopathic hypercalciuria, both untreated and treated with thiazide and/or cellulose phosphate.

Urinary oxalate excretion has been measured by a specific enzymatic method in normal subjects and stone formers with idiopathic hypercalciuria. In every group studied urinary oxalate was higher in the summer than in the winter. These differences were slight and not significant in normal subjects but were considerable and statistically significant in the stone formers both untreated and when treated with thiazide. Thiazides raise urinary oxalate only very slightly but cellulose phosphate leads to large rises in urinary oxalate both in the summer and the winter. The highest values of urinary oxalate were seen in the summer in patients treated with cellulose phosphate. The mean rise in this group was 70% above normal and this must be viewed with some anxiety.

Benzothiadiazines

Epidemiology of influenza in Lower Saxony during the period 1968-1978 with particular emphasis on subtypes A(H3N2) and A(H1N1) in winter 1977-78.

The influenza surveillance in Lower Saxony is based mainly on laboratory investigations, and especially those which involve the isolation of influenza viruses throughout the year. These investigations have provided information on the circulation of influenza viruses and of the antigenic drift during the Hong Kong period which resulted in many different variants. Since the advent of the Hong Kong virus subtype, a high excess mortality was observed only in the winter of 1969-70. In most of the other years there was a low excess mortality which coincided with the circulation of the influenza A viruses in the population. During the last winter 1978, influenza A viruses were not isolated before February. In February and March, the two distinct subtypes H3N2 and H1N1 circulated simultaneously. The influenza A(H1N1) virus attacked only children and young adults whereas the patients infected with influenza A(H3N2) virus ranged over all age groups.

Adolescent

Seasonal patterns in the transmission of Schistosoma haematobium in Rhodesia, and its control by winter application of molluscicide.

Surveys of snails occurring at water contact points used by rural people in Rhodesia show that transmission of Schistosoma haematobium is very high during the spring and early summer seasons. Although infected snails are found in all seasons, fewest occur in winter and during the heavy rains. It is suggested that the bionomics of this parasite depends on pre-rain transmission because destruction of infected snails during winter reduces the reservoir of infection in the area and also the level of parasitaemia in local schoolchildren.

Adolescent

A volumetric study of winter fungus prevalence in the air of midwestern homes.

Volumetric recoveries of airborne, mesophilic microfungi were made during winter months at three specific points in 150 single-family dwellings in southeastern Michigan. Mean levels of total isolates/m3 comprised a range of from less than 10 to over 20,000, although concurrent outdoor levels never exceeded 230/m3. Form species of Penicillium, Aspergillus, Cladosporium, and Rhodotorula as well as non-pigmented yeasts were the types encountered most widely indoors. Certain homes showed high recoveries of other types, including Cephalosporium, Sporobolomyces, Verticillium, and Sporothrix form species. A positive association between indoor fungus prevalence and bedroom relative humidity was strongly suggested, and high levels were observed in well-humidified homes despite the presence of electrostatic air cleaners. The data indicate characteristic patterns of (winter) air spora in specific homes and suggest that humidifying devices may serve as dispersion sources in addition to their permissive role in facilitating fungus growth.

Animals