Overexpression, purification and crystallization of a thermostable DNA ligase from the archaeon Thermococcus sp. 1519.

DNA ligases catalyze the sealing of 5'-phosphate and 3'-hydroxyl termini at single-strand breaks in double-stranded DNA and their function is essential to maintain the integrity of the genome in DNA metabolism. An ATP-dependent DNA ligase from the archaeon Thermococcus sp. 1519 was overexpressed, purified and crystallized.

[Isolation and characteristics of new thermostable DNA ligase from archaea of the genus Thermococcus].

The DNA ligase gene from thermophilic archaea of the genus Thermococcus (strain 1519) was identified and sequenced in the polymerase chain reaction. The recombinant enzyme LigTh1519 was expressed in Escherichia coli, purified, and characterized. LigTh1519 was capable of ligating the cohesive ends and single-strand breaks in double-stranded DNA (ATP as a cofactor).

Tightly regulated, high-level expression from controlled copy number vectors based on the replicon of temperate phage N15.

A new Escherichia coli host/vector system has been developed to allow a dual regulation of both the plasmid copy number and gene expression. The new pN15E vectors are low copy number plasmids based on the replicon of temperate phage N15, comprising the repA replicase gene and cB repressor gene, controlling the plasmid copy number. Regulation of pN15E copy number is achieved through arabinose-inducible expression of phage N15 antirepressor protein, AntA, whose gene was integrated into the chromosome of the host strain under control of the PBAD promoter.

[Suprapyloric resection of stomach in patients with ulcer disease].

Suprapyloric transversal resection of the stomach is one of relatively sparing methods of surgical treatment for ulcerative disease. In Medical Centre of "VAZ", suprapyloric resection of the stomach was carried out as a method of treatment of gastric ulcer in 181 patients (study group) and 139 patients underwent resection 2/3 of the stomach by Billroth-1 (control group). The ulcer located in cardial and mediogastric regions (1 type by Johnson).

[Chronic constipation and its treatment].

Altogether 850 patients suffering from chronic constipation were examined. Of these, 80% only showed functional changes in the intestine, 5% lost the defecation reflex, and 15% manifested inflammation-induced lesions in the intestine. 80% of the patients demonstrated symptoms of dysbacteriosis.

[The synthetic peptide preparation dalargin in the treatment of peptic ulcer].

The paper is concerned with the results of clinical assessment of a new peptide drug dalargin in therapy of duodenal peptic ulcer. Assessment of the efficacy of dalargin was compared to that of tagamet and placebo using double "blind" control. A total of 180 males with exacerbation of duodenal ulcer were examined, of them 90 received dalargin only, 70 received tagamet and 20 persons participated in an experiment based on a method of double "blind" control.

[Gastrin, gamma-endorphin and somatostatin cells of the stomach and duodenum in patients with duodenal ulcer treated with dalargin].

The distribution of gastrin-, gamma-endorphin and somatostatin-producing cells in antral and duodenal mucosa was studied in biopsies from 26 patients with duodenal ulcer and from 13 controls by the immunohistochemical (PAP) method. The number of antral somatostatin-producing cells after dalargin treatment was significantly higher in comparison with controls and patients treated with antacids plus atropine. These changes may be connected with the antiulcer activity of dalargin, a new opioid peptide drug.

[Effect of testosterone, its 5 alpha-reduced metabolites, estradiol and progesterone on the formation of an experimental duodenal ulcer in male rats].

The influence of different doses (0.01, 0.1, 1.

[Experience with the treatment of duodenal ulcer using H2-histamine receptor blockers].

The authors compared the efficacy of the blockers of H2-histamine receptors with the conventional multimodality treatment in patients with peptic ulcer of the duodenum and explored the effect of cimetidine on the secretory and motor functions of the stomach and on the endocrine status of the patients. It was established that cimetidine made the healing of duodenal ulcers more rapid as compared with the use of the multimodality therapy. It was also found that the drug efficacy was mainly related to the suppression of hydrochloric acid secretion in the stomach and to the recovery of motor activity of the stomach and duodenum.

[Immunomorphological methods for identifying cells of the APUD system of the digestive organs].

Possibilities of application of immunomorphologic methods to gastrointestinal apud cells study were evaluated. These are: immunofluorescent, immunoenzyme, immune-peroxidase, peroxidase-antiperoxidase, avidinbiotin. Causes of immunologic and non-immunologic non-specific background staining and the means of its elimination are discussed, as well as problems of fixation and embedding of the material.

[Effect of dalargin on the content of endorphins, leucine-enkephalin ACTH and corticosterone of the blood of stressed rats].

Stress caused by acute cysteamine duodenal ulcer was induced in Wistar male rats. All the endogenous opioides under study were involved in the stress-reaction mechanism. Protective dalargin (synthetic enkephalin analogue) administration revealed a tendency towards normalization of endorphin, L-enkephalin and ACTH blood levels.

[Dynamics of the basal gastrin concentration of duodenal ulcer patients during the development of remission of the disease].

The authors describe the results of studying basal gastrin secretion in patients with peptic ulcer of the duodenum at different phases of disease treated in 3 stages. It was revealed that basal secretion of gastrin experienced substantial changes in the course of transition from the phase of exacerbation to the phase of disease remission. It was noted that the onset of the clinico-endoscopic remission of peptic ulcer did not correlate in all the cases with normalization of basal gastrin level.

[Interrelation between the analgesic and ulcerogenic action of cysteamine].

Interrelationship was studied between the influence of cysteamine on pain threshold and ulcerogenic effect on the duodenum. Cysteamine (350 mg/kg) induced analgesia in mice which was prevented by naloxone (1.5 mg/kg).

[Evaluation of current preparations and local application in treating peptic ulcer exacerbation].

The effects of modern antiulcerous drugs and local action on the gastric mucosa by endoscopy were studied and compared. The endocrine characteristics of the blood serum were analysed in patients with duodenal ulcer after acute and prolonged use of antiulcerous drugs. The treatment with high doses of phosphalugel and cimetidine was shown to compare very favourably with conventional therapy.

[Clinical evaluation of hexapeptide dalargine used in the treatment of duodenal ulcer].

Experiments on rats were made to study antiulcerous activity of the majority of endogenous opioid-like peptides and 22 synthetic analogs. Duodenal ulcers were induced in animals by cysteamine hydrochloride. A hexapeptide called dalargin demonstrated the maximal antiulcerous activity in experimental duodenal ulcer.

[Effect of beta-endorphin on G-cells in rats with experimental duodenal ulcer].

Immunohistochemistry was used to study the changes in the number of G cells in the antral part of the stomach of rats (40 animals) with cystamine-induced duodenal ulcer treated with beta-endorphine. In the stomach of rats with cystamine-induced ulcer the number of G cells was discovered to be significantly increased, which was removed by an opioid peptide. Naloxone did not block the action of beta-endorphine.

[Endorphin-containing cells in the gastric antral mucosa in duodenal ulcer].

Immunohistochemical staining with the use of peroxidase-antiperoxidase was applied to study cells producing gamma- and alpha-endorphines in the gastric antral mucosa in duodenal ulcer. The cells producing gamma-endorphines were discovered to be mainly located in the epithelium of the cervical and upper third of the pyloric glands and to be alike G-cells producing gastrin. The cells producing alpha-endorphine were found both in the epithelium of the upper third of the gastric pyloric glands and in the gastric mucosa lamina proper.

[Morphometric evaluation of the effect of opioid peptides on cysteamine-induced ulcer in rats].

Morphometry was used to study the action of an enkephalin analog and beta-endorphine on the duodenal mucosa in rats with an experimental ulcer induced by cysteamine. Enkephalin produced a more powerful protective action than endorphine. The antiulcerous action was manifested in the diminution of dystrophic changes, redistribution of inflamed cells with an increase in the lymphocyte and monocyte counts, and in the reduction of the number of tissue macrophages and histocytes.