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PubMed1991

[Functional differentiation of thermoregulation, with particular references to seasonal variation of whole body sweat rate of exercising man].

We investigated the seasonal variation of sweating response during exercise. Four adult healthy men repeated a moderate bicycle exercise (60 watts) in a climatic chamber of an ambient temperature of 30 degrees C (relative humidity, 45%) in winter, spring, summer, and fall. In summer, sweat rate immediately increased as soon as the exercise started, whereas in winter in a few minutes. The mean sweat rate during exercise was significantly different between winter and summer. The transient reduction of the Tsk was observed at the beginning of the exercise in winter. The Tsk decreased in proportion to increasing of sweat rate in each season. Significantly negative correlations were found between sweat rate and the rate of change of Tsk during exercise in each season. The slope and intercept of regression line were significantly different between winter and summer. The index of sweating was made available for the relative value, changing rate against annual mean value of total sweat loss (delta SR, %). The relative value rather than the absolute value (i.e., expressed as g.m-2.h-1) corrected well with skin temperature. It is suggested that the present results may reflect adapted changes in the thermoregulatory mechanisms to seasonal acclimatization. Moreover, the fall in skin temperature during exercise may be not due to increased evaporative cooling, but may be the result of vasoconstriction probably caused by non-thermal factors.

Acclimatization↗
PubMed1986

Differential functioning on the Illingworth by home- vs institution-reared 3-month-old infants.

The performance on the Illingworth of 32 3-mo.-old home-reared Greek infants was compared to that of 22 infants reared in a modern institution. Home-reared infants were superior to institutional infants in every aspect of development except on Manipulations (fine motor coordination). It is speculated that the superiority of the home infants is attributed to the quality of the mother/caretaker-infant relationship.

Achievement↗
PubMedDate not supplied

Effects of hormones on functional differentiation of mouse respiratory epithelium.

The effects of corticosteroids and thyroxine on morphogenesis and differentiation of fetal respiratory epithelium were tested in serum-free culture. Strips from the margins of 16-day fetal mouse lungs, containing future respiratory branches, were cultured in medium containing growth factors plus different concentrations of dexamethasone and/or thyroxine. After 5 days, some of the cultures were processed for electron microscopy and the rest were used to quantitate unsaturated and saturated phosphatidylcholine. In the absence of thyroxine and dexamethasone, the lung tissue developed the equivalent of one more day in utero during the 5 days of culture, perhaps because of residual hormone in the tissue. Thyroxine and dexamethasone in concentrations compatible with normal physiological conditions permitted normal development from the pseudoglandular stage to the saccular stage, differentiation of respiratory cell types, and normal surfactant accumulation. Thyroxine alone gave essentially the same lack of morphological maturation and accumulation of disaturated phosphatidylcholine as culture in the absence of all hormone, but columnar epithelial cells held increased numbers of lamellar bodies. Dexamethasone alone at 10(-6) M gave essentially normal development. Dexamethasone at 10(-9) M was sufficient to permit almost normal development when combined with 10(-7) M thyroxine. We conclude that dexamethasone is required for normal maturation of the fetal lung and that thyroxine acts synergistically to lower the dexamethasone requirement. The presence of apparently authentic lamellar bodies under some conditions of low disaturated phosphatidylcholine accumulation make this morphological criterion suspect as a test for differentiation of type II cells.

Animals↗
PubMed1975

The morphological and functional differentiation of the alimentary canal of the pig during ontogeny. I. Development and differentiation of the fundic portion of the stomach.

Several periods of intensive growth are observed in the development of the fundus of pig's stomach: at the end of the 2nd and the beginning of the 3rd month of embryogenesis, the periods shortly prior to and after birth, and between the 10th and 20th day following birth. The gastric pits are formed at about the 45th day of embriogenesis. At the beginning of the third month the fundic glands are formed. The parietal cells first differentiate and are found in 60-day old embryos. The mucous neck cells are differentiated at the beginning of the 3rd month but secretion of mucoid substance starts on about the 45th to 50th day of the prenatal development. With increasing age of the pigs the quantity of PAS-positive substances in the surface epithelium, as well as in the mucous neck cells gradually increases. The differentiation of the chief cells rich in RNA occurs approximately on the 90th day of the prenatal development.

Age Factors↗
PubMed1975

The morphological and functional differentiation of the alimentary canal of the pig during ontogeny. II. Development and differentiation of the jejunum.

Morphological development and differentiation of the pig's jejunum during ontogenesis were studied. It was found that villi intestinalis are formed on about the 40th day of embryogenesis. The differentiation of absorptive epithelium, goblet cells and argentaffine cells as well as the formation of the Lieberkühn's crypts, and muscularis mucosae, occur by the end of the 2nd and at the beginning of the 3rd month of the prenatal development. The Paneth cells are found in the period around birth. After birth there is an adaptive rearrangement of the mucosa of jejunum affecting both the epithelium and the propria: the rearrangement is conditionally divided into two periods - from birth to the 3rd day, and from the 10th to the 20th day.

Age Factors↗
PubMed2001

[Potential functional differentiation of genome in the course of evolution and approaches to its study. I. Neontological annals of evolution and its analysis].

It is shown that the division of phylogenetical branches descends anisotomically. One new branch becomes evolutionary not active. Another one continues actively to develop. It allows to consider a system of present-day organisms as neonatological annals of evolution. A question arises on distinctions in the constitution of genomes of organisms belonging to active and inactive phylogenetic branches.

Evolution, Molecular↗
PubMed2001

[Potential functional differentiation of genome in the course of evolution and approaches to its study. II. Elucidation of diversity of phylogenetic lines].

It has been shown elsewhere (Chupov, 2001) that the branching of phylogenetical trunks goes by anisotomical way. Thus, in one of newly formed branches a possibility remains of a further evolutionary transformation, while taxa belonging to another branch sink into a prolonged evolutionary stasis. In the author's opinion, such a phenomenon is to be accompanied by distinctions in constitution of genetical cell devices of the taxa belonging to the branches with evolutionary contrasting potencies. In the article, an attempt is done to consider some other approaches relevant to this problem.

Evolution, Molecular↗
PubMed1975

Functional differentiation of the transmembrane sodium and calcium channels in mammalian cardiac fibers by use of specific inhibitors.

During excitation of the mammalian ventricular myocardium two transmembrane inward currents occur: a fast Na current and a slow current carried mainly by Ca. The Ca current is strongly reduced by some organic compounds like verapamil and compound D 600 which are known to be very effective inhibitors of excitation contraction coupling. A similar decrease in the Ca conductivity of the membrane is produced by the bivalent cations, Ni, Co, and Mn. The blocking action of these organic and inorganic inhibitors is reversed by increasing the extracellular Ca concentration. The slow inward current can also be restored by Sr and Ba ions. The reduction of the slow Ca current produced by verapamil, D 600, Ni, Co, or Mn occurs selectively since the fast Na current remains practically unchanged. This demonstrates the existence of two separate membrane channels for Na and Ca which can be blocked independently. Thus it is possible to modify the contractility of the myocardial cell via the magnitude of the Ca current without disturbance of the transmembrane Na current which is intimately connected with excitability.

Animals↗
PubMed2002

Regulation of APP-dependent transcription complexes by Mint/X11s: differential functions of Mint isoforms.

Mints/X11s are neuron-specific (Mints 1 and 2) and ubiquitous (Mint 3) adaptor proteins composed of isoform-specific N-terminal sequences and common C-terminal phosphotyrosine-binding (PTB) and PDZ domains. We now show that all three Mints bind to the cytoplasmic tail of amyloid-beta precursor protein (APP) and presenilins and strongly increase the levels of cellular APP in transfected cells. Immunocytochemistry revealed that in neurons, Mints 1 and 2 were colocalized with APP in the trans-Golgi network, with lower levels throughout the cell body and neurites. Using an APP-dependent transactivation assay that uses a fusion protein of APP coupled to the potent transcription factor Gal4/VP16, we examined the effects of Mints on the proteolytic processing and putative transcriptional function of APP. Although all Mints were biochemically similar, only Mints 1 and 2 but not Mint 3 strongly inhibited transactivation by APP-Gal4/VP16. Inhibition was enhanced by a mutation of the first PDZ domain and by deletion of the PDZ domains or the N-terminal sequences but abolished by inactivation of the PTB- and PDZ domains. Mint 1 also inhibited transactivation by the "precleaved" cytoplasmic tail of APP fused to Gal4/VP16, whereas Fe65 (which binds to APP as strongly as Mints) enhanced transactivation. Our data suggest that Mints 1 and 2 but not Mint 3 have a specific effect on APP function that cannot be explained simply by their interaction with presenilins and occurs at least partly after cleavage of APP. In view of their biochemical similarity, the functional differences among Mints are unexpected, suggesting that Mints 1 and 2 have a brain-specific function related to APP that is not executed by the ubiquitous Mint 3.

Adaptor Proteins, Signal Transducing↗
PubMed2002

The differential functions of imagery and verbal thought in insomnia.

Individuals with insomnia were exposed to a stressor (speech threat) prior to getting into bed and were instructed to think about the speech and its implications in either images (Image group, n = 14) or verbal thought (Verbal group, n = 17). Participants completed questionnaires about speech anxiety, arousal, and sense of resolution. Measures were taken of subjective (sleep diary estimates) and objective (actigraphy) sleep-onset latency. In the short term, the Image group reported more distress and arousal relative to those in the Verbal group. In the longer term, the Image group estimated that they fell asleep more quickly and, the following morning, reported less anxiety and more comfort about giving the speech compared with the Verbal group.

Adult↗