Changes in the digestibility of constituents of the diet in the rabbit]

Fiber digestibility of two diets (the first based on alfalfa dried, the second based on beet-pulp dried) with the same level of crude fiber and crude protein was measured on rabbits of 6, 7, 11, 13 and 17 weeks old. The age has no significative effect on digestibility (dry matter, organic matter, crude fiber) of the two experimental diets. The quantity of cellulose and hemicellulose digested was greater in rabbits on the pulp diet. Independantly of the diet hemicellulose is more digestible than cellulose. Expediency of use other analytical test than crude fiber in the nutritional requirements of rabbits is discussed.     

Potentiation of the gastro-protective effect of sulglicotide in the presence of cimetidine in the rat

The effects of sulglicotide, alone or combined with cimetidine, have been investigated on mucosal lesions induced in rats by pylorus ligation. In the same animals, the measurement of acid and pepsin output and of soluble and barrier mucus has been performed. Dose-dependent sulglicotide prevented the development of mucosal lesions and its protective effect was achieved without significant modifications in gastric acid secretion. The secretion of pepsin and of mucus was markedly inhibited at every dosage of the compound. Neither the damage to gastric mucosa nor the secretion of acid, pepsin and mucus were affected by cimetidine. The combination of the highest doses of both compounds resulted in a synergistic gastro-protective effect, not dependent on a synergistic effect on the reduction in acid secretion.     

Veins in the area of the mesencephalon

The veins on the surface of the mesencephalon were measured on 100 brain halves. The results of this measurements are discussed with issues of earlier authors.     

Changes in the sorption of the antigens of the causative agent of typhoid on erythrocytes in the dynamic immune response

The study of the adsorption capacity of erythrocytes in 4 strains of mice was made. According to the results of the determination of the background capacity of erythrocytes, the strains of mice, opposite with respect to the sorption of S. typhi Vi- and O-antigens, were selected. After the immunization of these mice with the killed culture of S. typhi, the process of the sorption of the antigen on erythrocytes showed a characteristic kinetics. The course of immune response was characterized by specific changes in the adsorption capacity of erythrocytes in all strains of mice: the increase of this capacity on week 1 was followed by its sharp drop on weeks 3-4 and its subsequent restoration to the initial level by weeks 7-8. The non-specific stimulation of the host had no essential influence on the kinetics of the fixation of S. typhi antigens on erythrocytes. Experiments with the passive immunization of the animals revealed that different receptors take part in the process of the sorption of Vi-antigen on erythrocytes, some of these receptors being related to antibodies.     

Role of neutrophils in the regulation of the reproductive tract microbiocenosis in women

The influence of neutrophils and their secretory products on the microflora of the vaginal contents in healthy women and in women having dysbiotic processes in the vagina was studied. The secretory products of neutrophils were found to produce a bactericidal effect on the representatives of the opportunistic bacteria, this effect being less pronounced with respect to lactic-acid bacteria. The established effect of neutrophils on bacteria is regarded as one of the mechanisms of microbiocenosis formation, ensuring colonization resistance.     

Participation of the estradiol receptor in the hormonal inhibition of cyclic nucleotide phosphodiesterase in the uterus

The role of estradiol receptor was studied in the inhibitory effect of hormone on the cyclic nucleotide phosphodiesterase from immature Wistar rat uterus. It was shown that the preparative separation of the enzyme and hormone receptor by ultracentrifugation in isokinetic sucrose density gradient results in a 2.5-3-fold decrease of the estradiol effect on phosphodiesterase. This effect is completely restored after adding the separated estradiol receptor to the phosphodiesterase devoid of it. The effect of estradiol on the phosphodiesterase activity depends on a degree of receptor component aggregation: the action of estradiol on the enzyme intensities after transformation of receptor into the dissociated form (4S) and removes in the presence of the receptor component associated form (8S).     

Dissymmetry of the origins of the roots of the spinal cord in the dog

The spinal cord in 25 non-inbred dogs has been studied macro-microscopically. The dissymmetry in the arrangement level in the right and left root bases on the dorsal surface of the spinal cord is much greater than on the ventral surface. The same as in the human being, the dissymmetry is the greatest in the thoracic part (as compared to other spinal parts). On the ventral surface of the spinal cord both along the anterior and posterior margin of the root bases, there is a right-sided dissymmetry (with cranial shift); on the dorsal surface it is present only at the roots along the posterior margin. The dissymmetry of the dog spinal cord is quantitatively estimated along its whole extension.     

The role of the aggregation of microbial cells in the development of salmonellosis in mice

The dependence of the invasive action of Salmonella typhimurium in mice on the aggregation of microbial cells has been studied in vivo, as well as in vitro on explanted intestinal tissue. The aggregation of salmonellae on kaolin grains has been found to lead to an increase in the level of adhesion of salmonellae to the intestinal mucosa of mice in vitro, to the accelerated course of infection in mice and their death and to the increased contamination of the spleen. The data obtained in these experiments age indicative of the possibility of the adverse influence of some sorbents on the course of the infectious process and confirm the concept advanced by the authors on the major importance of the surface concentration of salmonellae on the mucous membrane for the effectiveness of contamination.     

Mechanism of strengthening of the contractile activity in the duodenum and in the jejunum in psychogenic stress in rabbits

In experiments on unanaesthetized rabbits myoelectric activity (contractile activity index) of proximal (postpyloric) and distal sites of duodenum, and proximal part of jejunum was studied under stress induced by fastening a rabbit to a table in supine position. In both sites of duodenum, the stress impact induced a short-time decrease of contractile activity which was followed by its increase that exceeded the initial level. In the proximal part ofjejunum, the increase of contractile activity took place only during the second part of stress response. The strengthening of the contractile activity of the proximal part of duodenum was preserved after muscarinic or nicotinic cholinoceptor blockage, and after beta-receptor blockage. It was concluded that the contractile response of the proximal part of duodenum did not result from the contribution of central or local neurogenic mechanism, including excitatory cholinergic one, but was humoral in origin. The strengthening of the contractile activity of the distal part of duodenum and proximal part ofjejunum was abolished by muscarinic cholinoceptor and beta-receptor blockage, and resulted from the action of circulating catecholamines on the excitatory beta-adrenoceptor, localized on the cholinergic neurones of the enteric nervous system.     

Immunohistochemical localization of the transferrin receptor in the seminiferous epithelium of the rat

The transferrin receptor has been immunohistochemically localized in the seminiferous epithelium of the rat with a monoclonal antibody, MRC OX26, which recognizes the transferrin receptor glycoprotein. The receptor was detectable on mitotically and meiotically dividing germ cells and, less abundantly, on round spermatids. It was lost from germ cells during spermatid elongation and was undetectable on immature spermatozoa. The transferrin receptor was also present on Sertoli cells in the testes of immature animals and on Sertoli cells in the testes of aspermatogenic animals that had been irradiated in utero. It was not detectable on Sertoli cells in the testes of cryptorchid animals. These studies demonstrate that the transferrin receptor is abundant on dividing germ cells as well as dividing somatic cells.     

Recapitulation in the development of the components of the counterflow system in the vertebrate metanephros

The investigation has been performed on 107 renal preparations obtained from persons of various age (from 5-month-old fetuses up to 45 years of age), certain representatives of other classes of the Vertebrata are also included: fish, amphibia, reptile and mammalia at various stages of pre- and postnatal periods of ontogenesis by means of preparing graphic and plastic reconstructive models, histological investigation and microdissection. The complexity of the intrarenal branching of derivatives of the mesonephric duct diverticulum, development and structure of the canalicular part in nephrons directly depend on the phylogenetic position of the animal. Complexity of the nephron architectonics occurs along the progressive line of taxonomic groups of higher Vertebrata. The nephron loop becomes longer, thin segment of the nephron canalicular part increases in its length and, at last, in mammalia a cone-shaped fasciculus appears as a structural-functional unit of the osmoregulating apparatus of the constant kidney. In the comparative anatomical and comparative embryological aspects recapitulation is observed concerning certain morphological signs of derivatives of the metanephric duct and nephron.     

Experience in the use of electrified stands in the teaching of anatomy courses]

The paper reports the principles of arrangement and the estimation of efficiency of electrified training stands elaborated at the department. The work of the stand "Conducting pathways" is based on utilization of a distributing device which, due to different length of plates on the rotating disc, switches on a successive chain of lamps imitating conducting pathways. The stand "Human skeleton" is based on the principle of direct searching with use of a decade step-by-step switch (D55-100). The most complex in arrangement and efficient in use is the stand "Muscular system". The ruling diode matrix of this stand consisting of 450 diodes makes the electric impulse travel in the given strictly restricted direction. A special device permits controlling and estimating the process of learning the material.     

Changes in the electromechanical activity in the course of tetanic contraction

The functioning of excitation-contraction coupling during tetanic contraction was investigated on frog skeletal muscle. The effect of the calcium release blocker dantrolene was tested on electrically evoked twitches and tetanic contractions. It was shown that the first: developmental stage of tetanus is inhibited by dantrolene as well as a twitch contraction, and does not influenced by calcium-free medium. This substantiates it as based on "voltage dependent Ca-release" (VDCR) mechanism of activation, when depolarization directly opens the rhyanodin receptor calcium channels. The next stage: the long lasting plateau of tetanic contraction, is directly dependent on external Ca2+ entry and also inhibited by dantrolene, and therefore may be described as "calcium-induced Ca-release" (CICR) activation mechanism. It is proposed that such change in ECC mechanism taking place during tetanic contraction, can occur also in conditions of natural muscle activity, because of its rhythmical nature.     

Changes in the level of lectins in the mantle of the mussel Mytilus trossulus in response to anthropogenic contaminants

The lectin activity in an extract from the mantle of the mussel Mytilus trossulus was tested for the first time. Using the method of the hemagglutination inhibition assay, it was shown that lectins were Gal/GalNAc-specific and best agglutinated with rabbit erythrocytes. The influence of foreign compounds on the lectin level in the M. trossulus mantle was examined. Upon cadmium acetate exposure, the level of lectin activity exhibited phasic alterations and depended on the contaminant concentration or the time of exposure. During exposure of mussels to a synthetic detergent or diesel fuel, changes in lectin contents were dependent on the time of exposure.     

Changes in the blood-air barrier of the lungs in hyperthermia

The influence of hyperthermia on the ultrastructure of lung air-blood barrier (ABB) was studied in experiments on dogs. It was shown that in hyperthermia both mean arithmetic and mean harmonic thickness of ABB were increased. The lung capillary endothelial layer was the most thick ABB layer, in which severe micropinocytosis could be observed. Marked destructive changes were noted in lung alveolar epithelial ABB layer up to the appearance of cell content in alveolar space and denudation of the epithelial basal membrane.     

Cost-effectiveness of the modifications in the quality assurance system in radiotherapy in the example of in-vivo dosimetry

PurposeTo present the methodology for the evaluation of cost-effectiveness of the quality assurance protocol modifications associated with increasing demands on accuracy and reliability in radiotherapy and to present results on cost-effectiveness of in-vivo dosimetry as the chosen example of a technical procedure.Material and methodsIn-vivo dosimetry was used as an example of a quality assurance procedure, whose modifications have an impact on several procedures in the QA system and thus on the cost of radiotherapy. An analysis of 6864 patients, treated between 2001 and 2005 for tumours in the head and neck, breast, pelvis, or lung, was performed. The quality of radiotherapy was expressed as the accuracy of dose delivery and the cost was estimated from labour, equipment and materials.ResultsModifications implemented in the quality assurance protocol have gradually improved the quality of irradiation. Mean deviations between measured and calculated doses, recorded for several groups of treatment sites, were reduced from ?1.5% to 0.5%, 3.4% to 1.4%, 3.9% to 0.1% and ?2.1% to 1.8% for head and neck, breast, pelvis and lung respectively. The standard deviations of the measured values decreased also consistently. Total monthly cost in radiotherapy (related to in-vivo dosimetry) increased from € 4376 to € 10,696 while the unitary cost of radiotherapy procedures remained at the same level. The predominant cost component of in-vivo dosimetry was labour, limited at first to physics staff and later extended to quality assurance personnel and technicians.ConclusionThe application of the presented methodology revealed cost-effectiveness relationships in tested technical procedures.     

The role of sex in the determining the variability of the autoantibody levels in humans

Dependence of human antibody levels determined by immunoenzyme method on sex of an individual was studied. No significant impact of sex differences on phenotypic dispersion of the levels analysed both in healthy individuals and in those suffering from rheumatic diseases was shown. The data obtained point to the necessity of accounting sex in interpretation of the results of clinical observations.     

Histogenesis of the taste buds of the vallate papilla in the in the rat in the postnatal stages of development

The developing taste buds of vallate papillae were studied with electron microscope in rats during the first 7 days after birth. Two types of cells--light and dark--are identified in the taste buds of a one day old animal. The apical parts of dark cells are characterized by numerous dark granules. A distinguishing feature of light cells is the presence of synaptic contacts with afferent intragemmal nerves. On the 4th day of development on the top of the apical parts of the cell, a microvillar apparatus is seen to form, which does not yet communicate with the oral cavity. On the 7th day, basal cells appear in the taste buds. Some of these cells are seen mitotically dividing. The differentiated microvillar apparatus now communicates with oral cavity. The structure of the taste buds is getting similar to that in the adults. The structural and functional peculiarities of the developing taste buds are discussed in association with the period of ontogenesis under consideration.     

Examination of the role of follicle stimulating hormone in estrogen biosynthesis in vivo and in vitro in the ovary of the cyclic hamster

The effect of neutralizing endogenous follicle stimulating hormone (FSH) or luteinizing hormone (LH) with specific antisera on the in vivo and in vitro synthesis of estrogen in the ovary of cycling hamster was studied. Neutralization of FSH or LH on proestrus resulted in a reduction in the estradiol concentration of the ovary on diestrus-2 and next proestrus, suggesting an impairment in follicular development. Injection of FSH antiserum at 0900 h of diestrus-2 significantly reduced the ovarian estradiol concentration within 6--7 h. Further, these ovaries on incubation with testosterone (T) in vitro at 1600 h of the same day or the next day synthesized significantly lower amounts of estradiol, compared to corresponding control ovaries. Although testosterone itself, in the absence of endogenous FSH, could stimulate estrogen synthesis to some extent, FSH had to be supplemented with T to restore estrogen synthesis to the level seen in control ovaries incubated with T. Lack of FSH thus appeared to affect the aromatization step in the estrogen biosynthetic pathway in the ovary of hamster on diestrus-2. In contrast to this, FSH antiserum given on the morning of proestrus had no effect on the in vivo and in vitro synthesis of estrogen, when examined 6--7 h later. The results suggest that there could be a difference in the need for FSH at different times of the cycle. Neutralization of LH either on diestrus-2 or proestrus resulted in a drastic reduction in estradiol concentration of the ovary. This block was at the level of androgen synthesis, since supplementing testerone alone in vitro could stimulate estrogen synthesis to a more or less similar extent as in the ovaries of control hamsters.     

Changes in the glycosylation of IgG in the collagen-induced model of arthritis

It is now well established that rheumatoid arthritis patients have reduced levels of galactose on their immunoglobulin G (IgG) molecules compared with normal individuals. We have investigated whether, in an experimentally induced model of arthritis, similar glycosylation changes on IgG are to be found. Serum IgG was isolated from collagen-induced arthritic DBA/1 mice and a control group, and the glycosylation of the IgG in these preparations was compared using lectin blotting. The glycosylation of IgG in immune complexes was also analysed. Arthritic mice exhibited similar glycosylation changes on their IgG as observed for rheumatoid arthritis patients. On average, there was less galactose on the IgG from arthritic mice than from the control group, but this difference was of borderline significance. However, theN-acetylglucosamine content of IgG was significatly elevated in arthritic mice. There was no difference in the sialic acid content of IgG in the two groups. The results for immune complexes were similar to those obtained for serum IgG, but the data were limited by insufficient numbers. The similarity in glycosylation changes in collagen-induced arthritis and in patients with rheumatoid arthritis suggests that common pathogenic mechanisms may be involved.