Catalytic mechanism and substrate specificity of HIF prolyl hydroxylases

This review describes the catalytic mechanism, substrate specificity, and structural peculiarities of alpha-ketoglutarate dependent nonheme iron dioxygenases catalyzing prolyl hydroxylation of hypoxia-inducible factor (HIF). Distinct localization and regulation of three isoforms of HIF prolyl hydroxylases suggest their different roles in cells. The recent identification of novel substrates other than HIF, namely β2-adrenergic receptor and the large subunit of RNA polymerase II, places these enzymes in the focus of drug development efforts aimed at development of isoform-specific inhibitors. The challenges and prospects of designing isoform-specific inhibitors are discussed.

[Diagnostics of sepsis in the patients presenting with pyo-inflammatory ENT pathology]

The objective of the present study was to develop the algorithm for early clinical, laboratory, and instrumental diagnostics of sepsis in the patients presenting with pyo-inflammatory ENT diseases. The study included 50 patients with pyo-inflammatory ENT diseases complicated by generalization of infection. The scheme (algorithm) developed for their examination allowed to diagnose sepsis at the early stages of hospitalization in the patients presenting with pyo-inflammatory ENT pathology. The diagnostic algorithm included the criteria for syndrome of systemic inflammatory reaction (SSIR), the Kalf-Kalif leukocytic intoxication index (LII), the procalcitonin test (PKT), the integral severity of illness scale (APACHE-II) and the organ failure assessment score (SOFA). Timely preoperative diagnostics of septic complications and sanation of the primary infection site in the combination with early intensive therapy under conditions of a resuscitation department made it possible to avoid further progress of generalization of the infection and thereby to reduce the number of secondary interventions, to improve prognosis of the disease, and lower the mortality rate down to 12% in the study group (compared with 44% in the control one).

[Laboratory diagnosis of infected pancreonecrosis]

The results of treatment and examination were analyzed in 175 patients admitted to a clinic for sterile pancreonecrosis (PN). The significance of routinely available (clinical, biochemical, and microbiological) laboratory tests in the diagnosis of purulent complications was analyzed in patients with varying severity of pancreatic autolysis. Complex laboratory monitoring was found to be of importance in predicting and detecting infected PN with obligatory fine-needle punctures under ultrasound guidance and further microscopic studies of puncture specimens.

[Evaluation of axillary lymph nodes from the results of radioisotopic study]

The purpose of the investigation was to study the pattern of 99mTc (MIBI) technitrile uptake in the metastatically involved lymph nodes in breast cancer, by applying the plain scintigraphic technique. The scintigraphic study of the breast and regional metastatic areas by means of the radionuclide 99mTc (MIBI) technitrile was made on a Millennium GE tomographic gamma chamber. The radiotracer 550 (MBq) dissolved in 10-20 ml of saline solution was intravenously injected into the arm cubital vein contralaterally to the lesion. Following 20 minutes of injection of the agent, plain scintigraphy was carried out in three standard projections: frontal and two oblique ones. The scintigraphy was performed using a high-resolution collimator recording a 128 x 128 matrix image. The detector was maximally approximated to the organ being examined. A plain scintigraphic scan was recorded on each side for 10 minutes. By the degree of axillary lymph nodal involvement, the patients were divided into 3 groups in accordance with the international TNM classification: N0 (n = 55), N1 (n = 13), N2 (n = 4). Among 72 patients, axillary lymph nodes could be detected in 6, in 2 of them changes were not diagnosed by X-ray and ultrasound studies. The final pathomorphological study of intraoperative materials revealed axillary lymph nodal metastatic involvement in 17 patients. A micrometastasis in one lymph node was found in 1 patient. None of the radionuclide studies showed tumor spread in 5 cases. The sensitivity, specificity, and precision of the technique were 35.3, 100, and 84.7%, respectively. Thus, a combination of the high cost of the procedure, its radiation load on a patient, and its low sensitivity make the use of plain scintigraphy of axillary regions inexpedient in the complex of studies of the extent of breast cancer in the present development of technology.

Microarray analysis of differentially expressed genes after exposure of normal human fibroblasts to ionizing radiation from an external source and from DNA-incorporated iodine-125 radionuclide

Exposure of cells to ionizing radiation (IR) produces changes in the expression level of a large number of genes. However, less is known of gene-expression changes caused by local radiation exposure from radionuclides within cells. We studied changes in the genome-wide gene expression induced by decay of 125I incorporated into DNA as [125I]-iododeoxyuridine (125I-IUdR) in normal IMR-90 human lung fibroblasts and compared them with the changes produced by external gamma-radiation delivered at high (HDR) or low (LDR) dose rate. We found that more than 2000 genes were consistently up- or down-regulated following HDR and LDR gamma-radiation. The profiles of differentially expressed genes following HDR and LDR shared about 64% (up) and 74% (down) genes in common, with many genes identified as radiation-responsive for the first time. In contrast, in all only 206 genes changed their expression level in the 125I-IUdR-treated cells, even though the total number of DNA double-strand breaks (DSB) produced by 125I-IUdR exceeded that produced by the gamma-radiation. With few exceptions, the expression levels of 125I-IUdR-responsive genes were also altered following gamma-irradiation. Therefore, nuclear DNA-localized decays of 125I produce 10 times fewer differentially expressed genes than whole-cell exposure to gamma-radiation of comparable dose. These results suggest that the effect of IR on the changes in global gene expression depends on the distribution of energy depositions within the cell. In contrast to cell survival, DNA DSB may not be the major factor modulating changes in gene expression following irradiation.

Unambiguous identification of three beta-decaying isomers in 70Cu

Using resonant laser ionization, beta-decay studies, and for the first time mass measurements, three beta-decaying states have been unambiguously identified in 70Cu. A mass excess of -62 976.1(1.6) keV and a half-life of 44.5(2) s for the (6-) ground state have been determined. The level energies of the (3-) isomer at 101.1(3) keV with T(1/2)=33(2) s and the 1+ isomer at 242.4(3) keV with T(1/2)=6.6(2) s are confirmed by high-precision mass measurements. The low-lying levels of 70Cu populated in the decay of 70Ni and in transfer reactions compare well with large-scale shell-model calculations, and the wave functions appear to be dominated by one proton-one neutron configurations outside the closed Z=28 shell and N=40 subshell. This does not apply to the 1+ state at 1980 keV which exhibits a particular feeding and deexcitation pattern not reproduced by the shell-model calculations.

[Zenker's diverticulum]

An experience with treatment of 14 women and 15 men aged from 41 to 83 years with Zenker's diverticulum was analyzed. Most liable to the disease were people at the age from 50 to 70 years. The average duration of the disease was 3-4 years. All the patients were subjected to improved surgical interventions: resection of the diverticulum (11 patients), operations under the control of the endoscopic technique (18 patients). Resections of the diverticulum were combined with cryopharyngeal myotomy. No complications were noted. There were no lethal outcomes. So, wider indications to operative treatment in patients with Zenker's diverticulum, endoscopic methods used at all stages of treatment as well as improved methods of performing the operation enabled the authors to obtain good immediate and long-term results.

[Functional state of the hypothalamo-hypophyseal-ovarian system in female patients with tuberculosis of the genital organs]

Blood concentrations of LH, FSH, estradiol, prolactin, growth hormone, cortisol, testosterone and progesterone have been examined in 76 patients with active tuberculosis of the internal genitalia (group 1), 18 patients with longterm sequelae of clinically asymptomatic tuberculosis (group 2) and 41 patients with nontuberculous diseases of the internal genitalia. Abnormalities were identified in 56.5% of group 1 patients, 33% of group 2 and 46.4% of group 3 patients. The patients with active tuberculosis characteristically had a low gonadotropin and estradiol secretion. High prolactin levels were related to pituitary adenoma or tuberculous infection; polycystic ovaries were a cause of testosterone and stress of examination of cortisol elevation.

[Clinico-endoscopic evaluation of the effectiveness of the treatment of uncomplicated gastroduodenal ulcers after local administration of solcoseryl and aevit]

The complex of conservative measures for noncomplicated peptic ulcers included curative endoscopy in 105 patients, in 61 of them Aevitum was used as an application with additional injections of Solcoseryl around the ulcers. In 44 patients Aevitum was used along with Solcoseryl which was injected into the submucous layer around the pathological focus of the stomach and duodenum. The results obtained gave a convincing evidence of advantages of interstitial administration of Aevitum allowing to considerably shorten time of treatment (up to 10-12 days) of noncomplicated ulcers of the stomach and duodenum.

[Experimental measles infection in rodents]

The sensitivity of newborn hamsters to inoculation with the vaccine L-16 strain of measles virus and the Lec strain isolated from a patient with subacute sclerosing panencephalitis as well as the possibility of persistence of these viruses in the animals were studied. Intracerebral inoculation of the L-15 strain was shown to produce in hamsters acute meningoencephalitis leading to death in 85%-100% of cases. Over 30 days after inoculation, the infectious virus, the virus-specific antigen and virus genome were found in the brain. In the brains of the sick animals, all the structural proteins of measles virus with the exception of hemagglutinin were expressed. After inoculation with the Lec strain, the clinical signs of the disease were less manifest, and mortality was 40%. The infectious virus could be detected in the brain up to 20 days postinoculation, the genome, up to 31 days. All the structural proteins of measles virus were expressed in the brains of the inoculated animals. No persistence of L-16 and Lec strains of measles virus could be demonstrated at langer intervals after inoculation (90-180 days) in the brains of hamsters.

[Mutations in the alpha-amylase gene of Bacillus amyloliquefaciens, leading to a decrease in the temperature of protein inactivation]

Alpha-amylase genes of Bacillus amyloliquefaciens, coding proteins with reduced thermostability, had been obtained as a result of hydroxylamine mutagenesis. Temperature, pH and starch concentration dependences of two mutant alpha-amylases were investigated. The synthesis of the alpha-amylases by several B. subtilis strains with different levels of extracellular proteases was also studied. The mutation containing fragments were localized and the structures of the mutations were determined. It was found that the decrease of thermostability of mutant No 141 was due to Asp to Asn change at the position No 194 of the mature protein, and for mutant No 191--due to Glu to Lys change at the position No 185.

[Mechanism of stimulation of duodenal contractions by the greater splanchnic nerve]

The mechanism of duodenal motor activity stimulation has been studied in dogs during irritation of the chest area of the greater splanchnic nerve. It has been established that a stimulating effect of the splanchnic nerve was not removed either by bilateral vagotomy or by separate and combined injections of bretylium tosylate and benzohexamethonium, but was removed by the blockade of M-serotoninergic receptors of the autonomic ganglia with atropine or by the blockade of D-serotoninergic receptors of the smooth muscles with promethazine hydrochloride. The data obtained demonstrate the presence of noncholinergic and nonadrenergic fibers in the chest area of the greater splanchnic nerve, having a potent stimulating effect on duodenal contractions. According to our functional and biochemical tests, they are mediated by serotonin.

[Distribution of enzymes of nucleic acid biosynthesis and their precursors during fractionation of Escherichia coli MRE-600 extract]

Distribution of the enzymes of template-dependent and template-independent polynucleotide syntheses (DNA-polymerase I, RNA-polymerase, polynucleotide phosphorylase) as well as those of the biosynthesis of nucleic acids precursors (nucleotide kinases, acetokinase and nucleoside deoxyribosyltransferases) during fractionation of Escherichia coli MRE-600 cell extract was studied. On the basis of the results obtained a technological scheme was developed that enabled to combine routine procedures of purification of the above mentioned enzymes.

[Use of oil preparations for hemostasis in gastroduodenal hemorrhage]

The authors report on using oil preparations in endoscopic surgery for arrest of bleedings from vessels of the stomach and duodenum. Persistent hemostasis was obtained in 60 out of 64 patients.

[Open lavage of the abdominal cavity in diffuse suppurative peritonitis]

Experimental investigations (240 rats) and clinical observations (30 patients) have shown repeated open lavages to be effective in the postoperative period for the treatment of purulent peritonitis.