Enzyme-Substrate Reporters for Evaluation of Substrate Specificity of HIF Prolyl Hydroxylase Isoforms.

An organism naturally responds to hypoxia via stabilization of hypoxia-inducible factor (HIF). There are three isoforms of HIFα subunits whose stability is regulated by three isozymes of HIF prolyl hydroxylase (PHD1-3). Despite intense studies on recombinant enzyme isoforms using homogeneous activity assay, there is no consensus on the PHD isoform preference for the HIF isoform as a substrate. This work provides a new approach to the problem of substrate specificity using cell-based reporters expressing the enzyme and luciferase-labeled substrate pair encoded in the same expression vector. The cell is used as a microbioreactor for running the reaction between the overexpressed enzyme and substrate. Using this novel approach, no PHD3 activity toward HIF3 was demonstrated, indirectly pointing to the hydroxylation of the second proline in 564PYIP567 (HIF1) catalyzed by this isozyme. The use of "paired" enzyme-substrate reporters to evaluate the potency of "branched tail" oxyquinoline inhibitors of HIF PHD allows higher precision in revealing the optimal structural motif for each enzyme isoform.

Structure-activity relationship for branched oxyquinoline HIF activators: Effect of modifications to phenylacetamide "tail".

HIF prolyl hydroxylase is a major regulator of HIF stability. Branched tail oxyquinolines have been identified as specific inhibitors of HIF prolyl hydroxylase and recently demonstrated clear benefits in various scenarios of neuronal failure. The structural optimization for branched tail oxyquinolines containing an acetamide bond has been performed in the present study using HIF1 ODD-luc reporter assay. The special attention has been paid to the length of a linker between acetamide group and phenyl ring, as well as substitutions in the phenyl ring in the other branch of the tail. The optimized version of branched tail oxyquinolines is 3-fold more potent than the original one identified before and shows a submicromolar EC50 in the reporter assay. The compounds have been studied in a "liver-on-a-chip" device to question their hepatotoxicity towards differentiated human HepaRG "hepatocytes": the absence of hepatotoxicity is observed up to 200 µM concentrations for all studied derivatives of branched tail oxyquinolines.

[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).

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 ß2-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.

[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]. / Divertikul Tsenkera.

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.

[The significance of haptoglobin in the differential diagnosis of tuberculosis of the female genital organs]. / Znachenie gaptoglobina v differentsial'noi diagnostike tuberkuleza zhenskikh polovykh organov.

Study included 115 women with suspicion of genital tuberculosis. Combined clinical, X-ray and laboratory examination made it possible to classify patients into 3 groups: group 1 included 44 patients with active genital tuberculosis, group 2 32 women with clinically cured tuberculosis of internal genitalia and group 3 39 women with nonspecific genital diseases. The haptoglobin-tuberculin test was given to all patients. High haptoglobin parameters before or 72 h after tuberculin administration were found only in the group of patients with active genital tuberculosis. In groups 2 and 3 the haptoglobin level did not exceed normal values both before and after tuberculin administration in a dose of 50 TU. The informative value of serum haptoglobin parameters in patients with active tuberculosis of internal genitalia constituted 88.6%.

[Biochemical mechanisms of neurotoxic reactions to antibacterial preparations in patients with pulmonary tuberculosis]. / Biokhimicheskie mekhanizmy neirotoksicheskikh reaktsii na antibakterial'nye preparaty u bol'nykh tuberkulezom legkikh.

Examination comprising the electrophysiologic method and study of the biochemical parameters of the antioxidant/lipid peroxidation system and metabolism of biologic amines in 163 patients with infiltrative pulmonary tuberculosis has revealed a clear interaction existing between the functional changes of the CNS state, the state of antioxidative defense (alpha-tocopherol) and serotonin. This allows an assumption that the antioxidant/lipid peroxidation system and serotoninergic system actively participate in the pathogenesis of development of neurotoxic reactions to antibacterial preparations in the clinical picture of tuberculosis.

[Functional state of the hypothalamo-hypophyseal-ovarian system in female patients with tuberculosis of the genital organs]. / Funktsiia gipotalamo-gipofizarno-iaichnikovoi sistemy u bol'nykh tuberkulezom zhenskikh polovykh organov.

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.

[The effect of sodium oxybutyrate on various regulatory mechanisms of pulmonary hemodynamics in experimental tuberculosis in dogs]. / Vliianie natriia oksibutirata na nekotorye reguliatornye mekhanizmy legochnoi gemodinamiki pri éksperimental'nom tuberkuleze u sobak.

The role of cyclic nucleotides and prostaglandins E1 and F2 alpha in pulmonary hypertension formation was elucidated in experimental tuberculosis in dogs and the mechanism of a hypotensive action of sodium oxybutyrate specified with consideration of its influence on the non-gas exchange pulmonary function. The level of the above compounds was studied in the blood taken from the pulmonary artery and aorta in comparison with pulmonary artery pressure prior to and after intravenous injection of sodium oxybutyrate, an antihypoxant. Pulmonary vessel tone was found to depend on the cGMP content and synthesis in the lungs both in health and in tuberculosis and pulmonary hypertension in tuberculosis was associated with a deranged level and correlation of cAMP, cGMP and prostaglandins E1 and F2 alpha in pulmonary circulation. It has been demonstrated that the hypotensive effect of sodium oxybutyrate is associated with its influence on these biochemical parameters in plasma.

[Dynamics of biochemical indices in a favorable course of sarcoidosis of the respiratory organs]. / Dinamika nekotorykh biokhimicheskikh pokazatelei pri blagopriiatnom techenii sarkoidoza organov dykhaniia.

Sarcoidosis ran a favourable course in 166 out of 179 patients. The active phase of sarcoidosis was characterized by dysproteinemia, high content of histamine, STH and beta-lipoproteins together with a decrease of HPI and total protein. More remarkable shifts were observed in patients afflicted with sarcoidosis of the intrathoracic lymph nodes and of the lungs. In the phase of regression, there was a unidirectional change in the majority of the parameters, which correlated with the process liability to the reverse development. It may be recommended that the content of histamine, HPI and beta-lipoproteins should be measured along with other parameters to estimate the process activity in patients with respiratory sarcoidosis.

[The pro-fibrotic and pro-oxidant action of isoniazid]. / Profibroticheskoe i prooksidantnoe deistvie izoniazida.

As a result of experimental research on rats with destructive pulmonary tuberculosis, oxidative action of isoniazid in a dose of 50 mg per kg body weight, corresponding to the mean therapeutic dose of 10 mg/kg in man, was clearly defined. Fibrotic action of the drug was also shown. It manifested itself by a sharp rise of insoluble collagen levels in the lung tissue tuberculous lesion focus of the treated animals and in the formation of mature connective tissue. Two mechanisms of isoniazid's pro-fibrotic action are presented.

[Congenital absence of a kidney in a patient with the basal cell nevus syndrome]. / Vrozhdennoe otsutstvie pochki u bol'nogo s sindromom bazal'no-kletochnogo nevusa.

Basal-cell nevus was diagnosed in a 60-year-old patient who suffered for 20 years from multiple basal-cell carcinomas. Autopsy has revealed congenital absence of the right kidney and ureter after his death at the age of 61.

[Clinico-endoscopic evaluation of the effectiveness of the treatment of uncomplicated gastroduodenal ulcers after local administration of solcoseryl and aevit]. / Kliniko-endoskopicheskaia otsenka éffektivnosti lecheniia neoslozhnennykh iazv zheludka i dvenadtsatiperstnoi kishki pri mestnom primenenii solkoserila i aevita.

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]. / Eksperimental'naia korevaia infektsiia u gryzunov.

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.