Holism and life manifestations: molecular and space-time biology.

Appeals of philosophers to look for new concepts in sciences are being met with a weak response. Limited attention is paid to the relation between synthetic and analytic approach in solving problems of biology. An attempt is presented to open a discussion on a possible role of holism. The term "life manifestations" is used in accordance with phenomenology. Multicellular creatures maintain milieu intérieur to keep an aqueous milieu intracellulair in order to transform the energy of nutrients into the form utilizable for driving cellular life manifestations. Milieu intérieur enables to integrate this kind of manifestations into life manifestations of the whole multicellular creatures. The integration depends on a uniqueness and uniformity of the genome of cells, on their mutual recognition and adherence. The processes of ontogenetic development represent the natural mode of integration of cellular life manifestations. Functional systems of multicellular creatures are being established by organization of integrable cells using a wide range of developmental processes. Starting from the zygote division the new being displays all properties of a whole creature, although its life manifestations vary. Therefore, the whole organism is not only more than its parts, as supposed by holism, but also more than developmental stages of its life manifestations. Implicitly, the units of whole multicellular creature are rather molecular and developmental events than the cells per se. Holism, taking in mind the existence of molecular and space-time biology, could become a guide in looking for a new mode of the combination of analytical and synthetic reasoning in biology.

Age-dependent salt hypertension in Brattleboro rats: a hemodynamic analysis.

The hemodynamic effects of 0.6% saline, consumed either from youth (4th week of age) or from adulthood (12th week of age), were studied in unanesthetized, unoperated, and uninephrectomized homozygous female Brattleboro rats. Long-term saline drinking induced a general decrease of blood pressure in unoperated rats which was more pronounced in rats drinking it from youth. The relation of low systemic resistance and high cardiac output (observed at the age of 10-15 weeks) to the high mortality of these rats was discussed. Two phases were recognized in the development of salt hypertension in uninephrectomized rats drinking saline from youth. The increased systemic resistance played a major role during the early phase (13-15 weeks), while changes of body fluids as well as altered arterial compliance contributed to the elevation of systolic blood pressure in the late phase of salt hypertension (20-30 weeks of age). In uninephrectomized rats drinking saline from adulthood, the late blood pressure response was only slightly attenuated in comparison with uninephrectomized rats drinking saline from youth. The absence of increased arterial rigidity in the former group was the only major hemodynamic difference between these two groups of uninephrectomized rats aged 20-30 weeks.

Age-dependent differences in the effect of atrial natriuretic factor.

Replacement of drinking water by 1.8% NaCl solution produces a severe hypernatremia in prepubertal rats and only a moderate elevation of the plasma sodium concentration (pNa) in adults. Hypernatremia in prepubertal rats was reduced by infusion of blood from adult rats, whereas blood from young rats was without this effect. The aim of this study was to find out if the natriuretic factor containing atrial extracts from prepubertal (AEP) and adult (AEA) rats also differ in their ability to reduce hypernatremia in prepubertal rats. A decrease of pNa was observed 10 min after the administration of AEA (delta = -5.43 mmol/l). AEP failed to show this effect (delta = +0.92 mmol/l). No significant effect of AEA on pNa was observed in adult rats with moderate hypernatremia (delta = -1.88 mmol/l). Natriuretic and diuretic effects of AEP were also significantly lower than those of AEA if they were tested in prepubertal recipients, whereas no difference in activities of AEP and AEA was found in adult recipients. Possible mechanisms of the hypernatremia suppressing activity of AEA, causes of the differences in activities between AEA and AEP, and consequences of the low AEP activity for prepubertal rats are discussed.

Endogenous vasopressin and the weaning period in Brattleboro rats.

Vasopressin, which is important for behavior and brain development, begins to influence osmoregulation with the onset of weaning. We studied the role of vasopressin in the development of feeding behavior since its mechanisms might be essential for the age determination of the suckling and weaning periods. Radionuclide methods were employed to follow maternal milk, solid food and water consumption in developing Brattleboro rats. The appearance of solid food intake and the spontaneous extinction of maternal milk intake indicated the onset and the end of weaning. The absence of endogenous vasopressin did not influence the onset and/or the duration of the weaning period. Both vasopressin-deficient homozygous Brattleboro rats and their heterozygous littermates (with preserved vasopressin synthesis) began to consume solid food and water at the age of 16 days and their intake of maternal milk was terminated about the 27th day of age. Thus, the maturation of feeding behavior in the suckling and weaning periods is vasopressin-independent.

Preservation of left ventricular function during coronary artery bypass graft surgery.

Effects of hypothermic potassium cardioplegia on left ventricular performance and myocardial damage were assessed in 35 patients undergoing coronary artery bypass surgery. Hemodynamic data and enzymatic evidence of left ventricular ischemic damage were examined and compared in the immediate postoperative period. Left ventricular stroke work index showed a significant depression during the first hour with gradual recovery and a significant increase after 24 h. Myocardial specific isoenzyme creatine kinase (CK-MB) showed a very good nonlinear relationship with stroke work index within the whole range, whereas lactate dehydrogenase isoenzyme (LDH-I) had no relationship with the stroke work index. There was a high incidence of transient postoperative arrhythmias and electrical activity took a long time to stabilize. Left ventricular ultrastructure was generally well preserved. The results of this study demonstrate adequate structural and functional preservation of left ventricle by hypothermic potassium cardioplegia.

Traditions of Czech and Slovak developmental physiology.

Since the beginning of the 19th century, the comparative and ontogenetic branches of developmental physiology were cultivated in our country. Evidence was given that development of the gastrointestinal tract in tadpoles is dependent on the quality of proteins in their food. A complete metamorphosis of Amblystoma mexicanum, was entirely accomplished by feeding with powderized thyroid gland. The definition and chronological delimitation of both the suckling and weaning period in experimental animals opened the investigation of the effect of disturbance of the natural environment caused by premature weaning on the ensuing development of an individual. A new term was coined "late effects of early adaptations". Analysis was provided by impressive research of the development of energetic metabolism and development of gastrointestinal tract functions, water and electrolyte exchange and endocrine functions including the role of the pineal gland in control of circadian rhythms (12 references).

Late effects of early nutritional manipulations.

Effects of early neonatal interventions on metabolic parameters later in life (s.c. late effects) were studied in rats using two models; namely, (a) the effects of premature weaning and (b) the effects of "dietary" manipulations during the suckling period (s.c. small vs. large litters). (a) Premature weaning of rats caused an earlier degeneration of spermiogenesis and elevated plasma cholesterol levels in adult animals when compared to levels found in animals weaned 12 days later (on day 30 after birth). In adult rats, radioiodine uptake in thyroid glands was lower in the group weaned prematurely. Premature weaning was followed by a decrease of corticosterone production in adrenal glands in adult animals; in female adult prematurely weaned rats, an elevated response of adrenal cortex to stressors was observed. Several other studies explored the "immediate" effects of early, premature weaning. (b) Early exposure to high fat diet evoked a hypercholesterolaemic response in adulthood following brief exposure to HF diet. Rats from litters reduced to 3 or 4 pups per mother on postnatal day 3 exhibited 2 days later plasma levels of cholesterol higher than in rats raised in large litters of 8 or 14. The difference between small and large litters was preserved for the whole lifespan of the animals. In adulthood, rats from small litters were fatter and had higher levels of plasma cholesterol and insulin. Other studies suggester that early dietary experience may regulate the pattern of drug metabolism in adult life. An inhibition of diurnal plasma corticosterone variation was found in rats overfed during the neonatal period and an increased stimulation of lipolysis by norepinephrine and lipogenesis by insulin was demonstrated in neonatally underfed rats. Interesting studies were reported in longitudinally studies in children: at the age of 9-12 year breast-fed children (for more than 6 months) had the highest cholesterol levels; on the other hand significantly increased levels of APO B, Apo A1, ATH index and Apo/B Apo A1 quotient (p < 0.05) were found in the nonbreast-fed group (27 references).

Chemical prevention of colony foundation by Cryptotermes brevis (Isoptera: Kalotermitidae) in attic modules.

Disodium octaborate tetrahydrate (DOT) dust, DOT aqueous solution, imidacloprid dust, and amorphous silica gel dust with synergized 1% pyrethrins were applied on wood surfaces to simulated attic modules. Modules (30 by 30 cm) with and without fiberglass insulation were exposed to dispersal flights of Cryptotermes brevis (Walker) in May and June of 1998 and 1999. Six months after flights, modules were disassembled and inspected for nuptial chamber location and contents. During both years, air and water control treatments contained 22.2+/-9.94 (mean +/- SD) nuptial chambers, 7.5+/-5.7 live imagos, and 2.0+/-1.4 chambers with brood. This survivorship indicated that the attic modules performed well as a colonizing platform for C. brevis. C. brevis dealates preferred constructing nuptial chambers in the crevices at the bases or tops of the modules instead of internal crevices. Modules treated in 1998 and 1999 with DOT or silica dusts contained no live termites, whereas zero of five modules treated with imidacloprid dust in 1998 and two of 20 modules treated with imidacloprid dust in 1999 contained single live incipient colonies. In 1998, 15% DOT solution, applied as a postconstruction treatment, yielded significantly fewer chambers and live termites than controls, but was not as effective as dusts in preventing successful colonization. In 1999, the DOT solution, applied as a construction-phase treatment, was equally as effective in preventing colonization as the dust treatments during that year. Results indicate that dust formulations of DOT, silica gel, and imidacloprid can be used to prevent drywood termite colonization in existing building voids and attics. Where the entire wood framing is exposed to treatment, such as during building construction, aqueous DOT solution can be equally effective as dusts in preventing colonization by C. brevis.

[Possibility of affecting the regulation of salt and water uptake in the critical periods of development in rats]. / O vozmozhnosti vliianiia na reguliatsiiu priema soli i vody v kriticheskie periody razvitiia krys

Peculiarities in water and salt (NaCl) appetite were studied in rats under various experimental influences during critical periods of development. When sexual maturation is going on, females consume more salt than males. These sex depending differences may be altered by experimental influences but only during critical periods of development, for instance by injection of androgens into neonatal females or by gonadectomy of males, by premature cessation of rearing, etc. The effects of those early interventions manifest themselves after the termination of sexual maturation.

The pineal gland and the development of salt intake patterns in male rats.

The effect of gonadectomy, sham-gonadectomy, pinealectomy, and sham-pinealectomy on the concentration of NaCl in the total volume of fluid drunk per day ([NaCl]) in male rats offered a free choice between water and 3% saline was measured. Neonatal gonadectomy increased [NaCl] I in adult males but had no effect on immature rats. If the rats, however, were neonatally pinealectomized as well as gonadectomized, the increase of [NaCl] I also appeared in the immatures. Neonatal sham-pinealectomy decreased [NaCl] I in immature and adult rats, both gonadectomized and sham-gonadectomized. In adult neonatally gonadectomized males the effects of sham-pinealectomy did not occur in those animals actually pinealectomized. The role of the pineal gland in the regulation of water and salt intake is discussed in relation to the function of hypothalamus, neonatal stress, and sexual maturation.

Effect of ovarectomy of females and oestrogen administration to males during the neonatal critical period on salt intake in adulthood in rats.

The effect of interference in the neonatal critical period on water and salt solution (3% NaCl) intake by adult rats given a free choice of these fluids was studied. Consumption was expressed per animal, per 100 g body weight and as the NaCl concentration in the total daily fluid intake volume [NaCl]I. Newborn female rats were ovarectomized or sham-ovarectomized. Ovarectomy markedly reduces consumption and [NaCl]I in adulthood and brought these values close to the values in normal males. Newborn male rats were injected with 1 mg oestradiol propionate dissolved in oil or just with oil. Oestradiol propionate severely inhibited growth, but produced no changes in fluid intake per animal. The [NaCl]I values were likewise unaltered, but owing to the lower body weight comsumption values per 100 g b.w. were higher in rats given oestradiol propionate than in those given oil. The relationship of the given growth changes to the regulation of salt intake and to hypothalamic function and its sexual correlates is discussed.