Regeneration of the endothelium in the canine and feline thoracic duct.

Recent improvements in microsurgical techniques on lymphatic vessels facilitated the treatment of lymphoedema. But it is becoming clear that a successful treatment of lymphatic disease has to be based on knowledge of ongoing processes. Particularly, one of the important and unclear issue is cellular mechanisms of lymphatic regeneration.

Interhelical contacts determining the architecture of alpha-helical globular proteins.

An approach based on a presentation of alpha-helical protein topology as a graph is presented. The approach allows to estimate a role of each interhelical contact in the whole protein topology and to classify the contacts. It is shown that a consideration of only about a half of the whole pool of interhelical contacts exposed in the protein is enough for a determination of protein architecture.

Reduced smooth muscle cell regeneration in Yoshida (YOS) spontaneously hypercholesterolemic rats.

Hypercholesterolemia is a predisposing factor for atherosclerosis. We studied the response to damage of vascular smooth muscle cells (SMC) from normocholesterolemic Brown Norway (BN) and from spontaneously hyper-cholesterolemic Yoshida (YOS) rats (16-24 month old). The regrowth rate of SMC from BN and YOS rats after freeze-induced damage was similar in the presence of fetal calf serum and of serum derived from normocholesterolemic rats, while it was reduced in the presence of serum from hypercholesterolemic rats.

[Decrease in the level of DeoR-dependent repression of the deo operon as a result of integration of foreign DNA fragments into the interoperator deoO1-deoO2 region of the Escherichia coli chromosome].

Two heterologous DNA fragments encoding the genes Kanr and cat were integrated into the regulatory region of the deo operon of Escherichia coli, located in a recombinant plasmid. As a result, plasmids pD5K and pD5C were obtained, in which the distance between the deoO1 and deoO2 operators increased from 599 bp in the deo operon of the wild type to 2019 and 1398 bp in case of integration of Kanr and cat, respectively. Then, linearized DNA of plasmids pD5K and pD5C was incorporated into the deo locus of the chromosome of E.

Three-dimensional organization of biological tissues: a new method for investigation using scanning electron microscopy.

A new method is described which enables the visualization of hidden cellular surfaces of biological tissues. The method does not depend on the kind of fixative solution, the duration of the fixation, or the quantity of extracellular matrix. The samples are chemically dissociated with potassium ethoxide until the first individual cells appear in the solution.

[An optimized variant of plastic repair in a total-cavity rehabilitative hearing-preserving operation on the middle ear].

Therapeutic policy proposed by the authors in chronic otitis media purulenta (COMP) provides stable hearing-improving results. The procedure implies fixation of low T-shaped graft without catgut suture. Special tamponade of the postoperative cavity prevents damage to sound conduction system while dressing and improves the conditions of the trepanation cavity healing.

Neutrophil derived cathepsin G induces potentially thrombogenic changes in human endothelial cells: a scanning electron microscopy study in static and dynamic conditions.

Activated neutrophils may promote thrombus formation by releasing proteases which may activate platelets, impair the fibrinolytic balance and injure the endothelial monolayer. We have investigated the morphological correlates of damage induced by activated neutrophils on the vascular wall, in particular the vascular injury induced by released cathepsin G in both static and dynamic conditions. Human umbilical vein endothelial cells were studied both in a cell culture system and in a model of perfused umbilical veins.

[Measurement of distances between DNA segments for increasing the effectiveness of sequencing using hybridization on an oligonucleotide matrix].

DNA sequencing by hybridization on oligonucleotide matrix (SHOM) makes use of a matrix of immobilized oligonucleotides. Yet the method is not directly applicable for sequencing of fragments with long monotonous repeats. Measurement of the distances between certain segments within the DNA fragment analyzed provide additional information for sequencing.

Tn10-mediated inversions fuse uridine phosphorylase (udp) and rRNA genes of Escherichia coli.

Two strains carrying metE::Tn10 insertions (upstream of the udp gene) were used to isolate mutants of Escherichia coli overexpressing udp. These strains differ in their gene order; one contains an inversion between the rrnD and rrnE rRNA operons. Selection was based on the ability of overexpressed Udp to complement thymine auxotrophy.

Selective modification of putative uridine-binding site of uridine phosphorylase from E. coli with fluorescein 5'-isothiocyanate.

A putative uridine-binding site of uridine phosphorylase (EC 2.4.2.

Effect of cholesterol-supplemented diet in heritable hyperlipidemic Yoshida rats: functional and morphological characterization of thoracic aorta.

In this study we have considered the possibility of inducing vascular damage in Yoshida Pittsburg (YOS) rat, an inbred strain which has endogenous hyperlipidemia without vascular atherosclerotic damage. Cholesterol-enriched diet (4% cholesterol plus 1% cholic acid and 0.5% thiouracil) was administered to YOS rats, in order to induce atherogenesis.

[A compressed form for presenting data to banks on the primary and spatial structure of biopolymers. Means for accessing compressed data banks].

Description of open CAN format (Compressed Amino acids and Nucleotides) is presented for storing genetic information in compressed form in data banks (DB). Data compression principles are demonstrated in detail on examples of EMBL DB (sequences of nucleotides), SWISSPROT DB (sequences of amino acids) and PDB DB (3D structures). A unified compressed data format provides a possibility to integrate EMBL, SWISSPROT, and PDB DB in one data bank.

The influence of radiotherapy and chemotherapy on regeneration at arterial microanastomoses: an experimental and clinical study.

The regeneration of anastomosed aortas after radiotherapy and chemotherapy was studied by light, scanning, and transmission electron microscopy in a rat model. At the ultrastructural level, it was observed that sublethal doses of these methods of cancer treatment did not severely block endothelial proliferation in the region of the microanastomosis. Based on the experimental results, myocutaneous free flap transfers were completed in patients with malignant tumors who had been undergoing radiotherapy and chemotherapy to cover defects resulting from their excision.

[Preliminaries to a study of epidemiology of occupational cancer among workers of shoe factories].

Data presented in literature proves frequent malignancies of various localizations in workers engaged into footwear production, which could result from exposure to leather, rubber dust and some chemicals (polyvinylchloride, chloroprene and others). Hygienic studies of air at footwear production demonstrate that the workers at their workplaces are exposed to such occupational hazards as dust, chemicals. Epidemiologic research to reveal possible correlation between work conditions and the workers' health are expedient.

The tunica media of the thoracic duct contains a heterogeneous population of muscle cells.

The three-dimensional cyto-architecture and ultrastructure of cells composing the different regions of the tunica media of canine and feline thoracic ducts (ThD) were investigated by scanning and transmission electron microscopy. The tunica media of the intervalvular regions consists of 2-4 layers of circulatory oriented ribbon-like smooth muscle cells (SMCs) of the contractile phenotype. Spot-like membrane contacts similar to gap junctions were observed between SMCs.

[Physiologic and hygienic evaluation of the job and health status in workers of shoe factory].

The article contains materials on complex physiologic and hygienic evaluation of work performed by various shoe-making occupations. The main occupational hazards are air pollution with chemicals, noise, vibration, considerable physical and psychophysiologic strain, visual exertion, inadequate working posture. The workers demonstrated fatigue of the main body functions during the shift.

Pathogenetical consideration of spontaneous dural arteriovenous fistulas (DAVFs).

Sinus thrombosis has been regarded as an aetiological factor in DAVFs. However, this claim has been disputed in the literature; because it is not possible to prove that DAVFs arise as a result of sinus thrombosis in all cases, and there is evidence that venous thrombosis can be acquired from a DAVF. The purpose of this study is to examine the hypothesis that the different angiomorphologies of DAVFs depend on the location of their venous outflow, and that a territorial classification of spontaneous DAVFs can be created which is based on their acquired development as a consequence of the breakdown of autoregulation of dural microvascularisation after venous thrombosis.

[Current status of laboratory diagnosis of infections caused by nonspore-forming anaerobes and ways of its improvement].

Nonspore-anaerobic bacteria are the most common pathogens of purulent opportunistic infection. However, this group of infections is not recorded in our country due to the lack of national culture media and special laboratory equipment for anaerobic bacteriology. The laboratory diagnosis of infections caused by nonspore-forming anaerobes are analyzed and urgent measures to solve this topical problem are defined.

Endothelialized myointimal thickening in the rat aorta as a result of extensive freeze injury.

The regeneration of rat aorta intima and medial layer was examined after extensive freeze injury that caused the death of both endothelial and smooth muscle cells. After 1 month complete re-endothelialization of the denuded area was observed. In parallel, myointimal thickening was formed by the smooth muscle cells (SMC) from the uninjured edges and its thickness increased with time.

[The regional morphological characteristics of the endothelium of the human thoracic aorta in perfusion fixation].

The ultramicroscopic organization and the endotheliocyte surface relief in ventral portions of the thoracic part of human aorta and in zones of division of blood flow were studied under conditions of early post mortem examinations and perfusion fixation of corpses of 14 humans dead from accidental causes. Zones of entrance into the intercostal aortas are compared with the straight portions of the aorta and are found to be characterized, as compared with the latters, by polymorphism of the endothelium, higher adhesiveness of its surface to blood elements, as well as by the presence of intravitally de-endothelialized portions localized on the ridge of the intimal valve.

[The distribution of hematoporphyrin derivatives in the animal body].

The pharmacokinetic distribution of haematoporphyrin derivative (HPD) and synthetic oligomeric haematoporphyrin (OG) which showed various lipophilicity was studied in animal tumor and normal tissues. The accumulation of dyes in tissue and their tumor-seeking capacity depended on the degree of polymerization, lipophilicity, and ratio of dye components. The difference in the absolute concentrations of HPD and OG (6.

Evidence for the presence of early vascular lesions in newborn Watanabe heritable hyperlipidemic (WHHL) rabbits.

We have investigated the morphology of the aortic wall of newborn New Zealand White (NZW) (n = 10) and newborn Watanabe heritable hyperlipidemic (WHHL) (n = 10) rabbits. In both strains, lipid levels (cholesterol and triglycerides) were elevated above the concentrations expected. This was particularly evident in WHHL.

[The morphogenesis of the tunica elastica interna of the rat aorta in the early periods after birth].

The ultrastructural and three-dimensional spatial arrangement of the internal elastic membrane (IEM) of the rat's aorta was studied by transmissive electron microscopy, native and scanning electron microscopy of chemically extracted specimens. Changes in the passage of different levels of organization of IEM is shown in the process of its maturation in postnatal ontogenesis. The first--fibrillar--step of morphogenesis of IEM is characterized by the formation of microfibril fascicles in 10-day-old animals.

[The application of a periarterial synthetic tube results in the formation of rhythmic structures in the intima].

Structure of rabbit carotid artery and aorta after their wrapping with synthetic tube was investigated using light and scanning electron microscopy. Periarterial manipulations lead to the development of myointimal thickening covered with endothelium. Surface of the thickening consisted of rhythmically intermitted elevations and pits situated across the long axis of the vessel.