Characteristics of the "no-reflow" phenomenon in reperfusion of the myocardium depending upon the duration of ischemia

The dynamics of changing dimensions of "no reflow" area following reperfusion after 30 min-1 h-long ischemia is characterized by three basic phases. The reperfusion following and hour-long ischemia altered considerably the character of phases of "no reflow" phenomenon. The data obtained suggest that the therapy of transitory ischemia must be directed not only to ischemia itself, but also to postischemia reperfusion-induced "no reflow" phenomenon.     

The influence of the testis on the fertilizing life of spermatozoa in the ligated vas deferens of the golden hamster

Spermatozoa in the vas deferens of the hamster lose their fertilizing capacity 3 days after ligation of the initial part of the duct and after 2 days if the testes are removed at the time of ligation. Sham-ligation had no effect on the fertilizing life of vasal spermatozoa on the contralateral side even 3 days after bilateral castration. Unilateral castration for 3 days had no effect on the fertilizing capacity of spermatozoa from the ipsilateral unobstructed duct, whereas no eggs were fertilized by spermatozoa from the contralateral ligated duct associated with the remaining testis. Unlike testosterone, 5alpha-dihydrotestosterone injected daily or implanted subcutaneously in Silastic tubes maintained normal fertilizing capacity for 2 days in castrates and for 3 days in intact males. Within each group, ligation had no effect on the level of fructose in the seminal vesicle on that side compared with the level in the gland on the other side.     

Comparison of the effects of chemical and isotopic dilution on the dissociation of bound labeled ligands

The dissociation of a labeled ligand from a binding structure to which it is reversibly attached can be promoted either by dilution or by chase. The kinetics of the dissociation brought up by dilution can be modified or not by the presence of various concentrations of cold ligand, according to the molecular mechanism of interaction. Analog computer simulation leads to the following results: (i) no cooperativity, monomolecular dissociation: no modification; (ii) positive or negative cooperativity (sequential models): acceleration, no modification, or slowing down (according to the kinetic constants); (iii) positive cooperativity (concerted model): no modification; (iv) two-step interaction: no modification if both interaction steps take place in the same phase, otherwise acceleration; and, (v) bimolecular association and dissociation: acceleration. This methodology could be used in order to characterize the molecular properties of various binding structures in the field of drug and hormone receptors as well as in enzymology.     

Gnathostome vertebrae and the classification of the Amphibia

Four pairs of arcualia were primitively present in each segment of gnathostomes. The individual vertebral ossifications of early temnospondyls are most economically interpreted as the endochondral ossifications of these cartilaginous arcualia. Centra have formed independently on at least two occasions within the tetrapods and arcualia play little or no part in the formation of true centra in any living form. The so called pleuro- and intercentra of the temnospondyls can in no way be homologized with the centra of either lissamphibians or amniotes. The Nectridea are considered to be the sister group of the Lissamphibia and the Aistopoda the sister group of these two. The anthracosaurs, seymourians and microsaurs are regarded as amniotes. There is no evidence for resegmentation in the vertebral column.     

The hypothalamo-hypophysial system of the lemming Dicrostonyx torquatus Pallas. IV. Influence of experimental animal cooling on the ultrastructure of the hypothalamo-posthypophysial neurosecretory system

The reaction of the hypothalamo-hypophysial neurosecretory system (HHNS) of lemmings to cold (+4 degrees C) was studied by the method of electron microscopy. The animals were kept in cages with nest, but with no wheel to allow running; in cages with a wheel, but with no nest; in cages with no nest and no wheel. No changes in the HHNS reaction were revealed under cold stimulation, if the animals were not deprived of motor activity (running in a wheel), or could hide in a nest. In case of no nest and restricted motor activity exposition to low temperature led to a progressive activation of neurosecretory cells of the supraoptic and paraventricular nuclei, and finally to their exhaustion and degeneration. The intensity of the HHNS reaction to cold is shown to depend on the initial state of the system which varies according to the stages of population cycle. The present study gives grounds to put forward the hypothesis that the adaptation of the Dicrostonyx torquatus Pallas to cold is made possible due to maximal utilization of ecological conditions and behavioral reactions.     

Segmental Aneuploidy and the Genetic Gross Structure of the Drosophila Genome

By combining elements of two Y-autosome translocations with displaced autosomal breakpoints, it is possible to produce zygotes heterozygous for a deficiency for the region between the breakpoints, and also, as a complementary product, zygotes carrying a duplication for precisely the same region. A set of Y-autosome translocations with appropriately positioned breakpoints, therefore, can in principle be used to generate a non-overlapping set of deficiencies and duplications for the entire autosomal complement.-Using this method, we have succeeded in examining segmental aneuploids for 85% of chromosomes 2 and 3 in order to assess the effects of aneuploidy and to determine the number and location of dosage-sensitive loci in the Drosophila genome (Figure 5). Combining our data with previously reported results on the synthesis of Drosophila aneuploids (see Lindsley and Grell 1968), the following generalities emerge.-1. The X chromosome contains no triplo-lethal loci, few or no haplo-lethal loci, at least seven Minute loci, one hyperploid-sensitive locus, and one locus that is both triplo-abnormal and haplo-abnormal. 2. Chromosome 2 contains no triplo-lethal loci, few or no haplo-lethal loci, at least 17 Minute loci, and at least four other haplo-abnormal loci. 3. Chromosome 3 contains one triplo-lethal locus that is also haplo-lethal, few or no other haplo-lethal loci, at least 16 Minute loci, and at least six other haplo-abnormal loci. 4. Chromosome 4 contains no triplo-lethal loci, no haplo-lethal loci, one Minute locus, and no other haplo-abnormal loci.-Thus, the Drosophila genome contains 57 loci, aneuploidy for which leads to a recognizable effect on the organism: one of these is triplo-lethal and haplo-lethal, one is triplo-abnormal and haplo-abnormal, one is hyperploid-sensitive, ten are haplo-abnormal, 41 are Minutes, and three are either haplo-lethals or Minutes. Because of the paucity of aneuploid-lethal loci, it may be concluded that the deleterious effects of aneuploidy are mostly the consequence of the additive effects of genes that are slightly sensitive to abnormal dosage. Moreover, except for the single triplo-lethal locus, the effects of hyperploidy are much less pronounced than those of the corresponding hypoploidy.     

The nonspecific changes in the immune system to the administration of the membrane-ribosomal fraction of the causative agent of pseudotuberculosis

Nonspecific changes in different elements of the immune system of animals under the action of Y. pseudotuberculosis membrane-ribosomal fraction (MRF) with high protective potency have been studied for the purpose of the analysis of the preparation for immunological safety. MRF has been shown to produce no changes in humoral immune response to antigens of different nature or to enhance this response, to produce no essential effect on the intensity of the reaction of delayed hypersensitivity to sheep red blood cells and to stimulate phagocytic processes in peritoneal macrophages and polymorphonuclear leukocytes.     

The Effect of the Addition of Copper Sulphate to the Diet on the Bacterial Flora of the Alimentary Tract of the Pig

S ummary : The use of copper sulphate as a dietary supplement had no observable effect on the bacterial content of the alimentary tract of the pig.     

Evaluation of the effectiveness of antibacterial therapy

It is recommended to estimate the clinical effect of antibacterial therapy in patients with different purulent inflammatory complications with an account of the data on both the clinical and bacteriological examinations. The full affect consisted in disappearance of the clinical signs and complete bacteriological sanation of the purulent inflammatory foci. The partial effect was shown by a marked decrease in the clinical manifestations without complete bacteriological sanation of the foci. The ill effect was evidenced by clinical picture having no time course and no favourable time course in bacteriological tests. No effect was indicated by deterioration of the clinical picture and no favourable time course in the bacteriological tests.     

Comparative histochemical and electron microscopic studies of the sinus and venous walls of the human spleen with special reference to the sinus-venous connections

Sinus and venous walls of normal human spleens were studied with enzyme histochemical and electron microscopic methods. Particular attention was paid to the connections between sinuses and veins. Histochemically the sinus lining cells revealed a distinct naphthol-AS-acetate-esterase activity but no reaction for alkaline phosphatase. Venous endothelial cells were positive for the latter but negative for the former enzyme. In the sinus-venous junctional area there were no endothelial cells with reactivity for both enzymes. Electron microscopically both the sinus lining cells and the venous endothelial cells could be clearly characterized and therefore easily distinguished from one another on morphological grounds. There were no clear ultrastrural indications of transitional forms between sinus lining cells and venous endothelial cells in the sinus-venous area. According to these findings, sinus lining cells represent a specialized endothelium, but one with practically no morphological similarities to the venous endothelium.     

Effect of heparin on the activation of the anticoagulation system by alpha-thrombin

Heparin-regulated alpha-thrombin ability to activate the response of the anticoagulation system has been studied by the perfusion of sinocarotid area of rabbits with DIP-alpha-thrombin-heparin complex. In a series of experiments the area was perfused with 1.8 micron DIP-alpha-thrombin and significant changes in anticoagulation parameters have been registered in systemic circulation. During perfusion of sinocarotid area by DIP-alpha-thrombin-heparin complex (2 microns) no activation of anticoagulation system was noted. DIP-alpha-thrombin-heparin perfusates contained no endogenic heparin, unlike DIP-alpha-thrombin perfusates. This confirms the absence of anticoagulation system response to DIP-alpha-thrombin. Control perfusion by heparin alone in equimolar concentrations revealed no changes in anticoagulation system. It is assumed that heparin, blocking cation subcentre of the recognition centre for high molecular compounds in the enzyme molecule, prevents the response of anticoagulation system, disturbing the enzyme ability to bind to specific receptors of the vascular walls.     

The renal response to the ingestion of fluid by the fetal sheep

To see if the variability in fetal urine flow and sodium excretion was related to fetal drinking activity, renal function was investigated in two groups of oesophageally-ligated fetuses and one group of non-ligated fetuses. There was no significant difference in urine flow, sodium excretion or glomerular filtration rate in the ligated fetuses compared with the non-ligated fetuses. Furthermore, oesophageal ligation had no effect on the variability in urine flow and sodium excretion rate. The response of fetal kidney to ingestion of fluid was investigaeed in 2 groups of oesophageally-ligated fetuses. In one group it was shown that ingestion of 20 ml/kg of amniotic fluid by the fetus had no consistent effect on fetal renal function. In the other group it was shown that the ingestion of 200 ml water also had no consistent effect on fetal renal function. The water load caused a rise in fetal blood pressure and a fall in plasma osmolality. Since there was no significant increase in free water clearance and fetal plasma osmolality decreased then rose towards control levels, it is concluded that the oral water load was absorbed from the fetal gastrointestinal tract and diffused out of the fetal compartment across the placenta. These experiments show that fetal drinking is probably not responsible for the variability often seen in fetal urine flow and sodium excretion rate.     

Relationship of conceptus number to the action of luteinizing hormone-antiserum in the pregnant rat

Treatment of pregnant rats on Day 12 of pregnancy with luteinizing hormone-antiserum (LH-AS) (equine anti-bovine LH) had no effect on the maintenance of pregnancy or serum progesterone levels in rats bearing either 2 or more than 8 conceptuses. In rats with only 1 conceptus, LH-AS administration resulted in a significant decline in serum progesterone to basal levels within 24 h and all animals (n = 6) failed to maintain pregnancy. All rats with either 1, 2 or greater than 8 implantations showed no effect of normal horse serum (NHS) administration. There was no effect of LH-AS administration on serum testosterone levels, compared to NHS-treated controls.     

Ultrastructure of the Peritrich Ciliate Ambiphrya ameiuri and Its Attachment to the Gills of the Catfish Ictalurus punctatus1

Ambiphrya ameiuri is an ectocommensal peritrich that attaches to the gills of warm-water fishes and filters bacteria from the water. The ultrastructure of this protozoon, its attachment to the fish gills, and its effect on the gill tissue were investigated by scanning and transmission electron microscopy. The peritrich attached to the gills by fibers extending from the scopula. A microtubular array, apparently a barren kinetosome, was present in each lobular projection, but no scopular cilia were observed. At low densities Ambiphrya had no apparent harmful effects on the fish; however, at high densities respiration may be impeded. Ultrastructural studies indicate that this organism receives no nourishment from the host tissue.     

Effect of temperature and photoperiod on the growth of the embryonic dogfish, Scyliorhinus canicula

Photoperiod has no effect on the growth of embryonic dogfish. Conversely, developmental rates are highly susceptible to temperature variation. Embryos maintained at 16°C grew faster and ecloded earlier than those maintained at 10°C. Increased temperature had no effect on size at eclosion.     

The properties of the lining membrane of the insect tracheal system

In the surface layer of the lining cuticle of the tracheae of adult Calliphora there is no sign of any waterproofing layer of cuticulin (sclerotin + lipid) as seen in the surface of the general body cuticle. In a few insects: Calliphora adult thorax, Rhodnius adult tracheae serving the ovary, Periplaneta abdominal tracheae, it has been possible to introduce silver hydroxide solution into the lumen of tracheae in the living insect. In each case the silver hydroxide reacted at room temperature with the argentaffin structures in the cuticle, as happens in the soft surface cuticle of Rhodnius larva before moulting or after gentle abrasion. In the thorax of Calliphora the taenidia of the tracheae are stiffened by argentaffin cuticulin. but immediately upon entering the cleft in the flight muscle the taenidia disappear and are replaced by simple folds, so that no stiff taenidia enter the muscle and there is no argentffin material deeper in the flight muscle system.     

Situation of brucellosis in the regions of Stavropol Territory affected by the flood of 2002

The emergency situation caused by inundations and high floods on the rivers in the affected regions exerts no direct influence on brucellosis morbidity among humans. Still the urgent evacuation of agricultural animals in connection with the natural calamity, their displacement and regrouping give grounds to prognosticate the deterioration of the epizootic situation in this infection in a number of regions of the territory where no sufficient veterinary surveillance has been ensured.     

Evolution: revenge of the clones!

Recent work on ants shows both extraordinary patterns of reproduction and a new type of sexual conflict, leading to the remarkable scenario where females have no father and males have no mother.     

On the nature of the granules of the genus spirillum

Summary Chemical analyses of centrifugal fractions of cell-free extracts of three spirilla and Sacch. cerevisiae showed that the granular inclusions accumulated by these organisms do not contain significant amounts (if any) of polyphosphates. Further, no trichloroacetic acid extractable-barium precipitable polyphosphates could be isolated from the spirilla. Thus, the granules of spirilla, heretofore called volutin, are not identifiable with polyphosphates.The phase opaque bodies present in members of this genus are composed primarily of poly--hydroxybutyrate. It is recommended that the term volutin no longer be used to describe granules showing a metachromatic reaction.