A Mouse Amidase Specific for N-terminal Asparagine: the gene, the enzyme, and their function in the N-end rule pathway

The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal residue. In both fungi and mammals, the tertiary destabilizing N-terminal residues asparagine and glutamine function through their conversion, by enzymatic deamidation, into the secondary destabilizing residues aspartate and glutamate, whose destabilizing activity requires their enzymatic conjugation to arginine, one of the primary destabilizing residues. We report the isolation and analysis of a mouse cDNA and the corresponding gene (termed Ntan1) that encode a 310-residue amidohydrolase (termed NtN-amidase) specific for N-terminal asparagine. The ~17-kilobase pair Ntan1 gene is located in the proximal region of mouse chromosome 16 and contains 10 exons ranging from 54 to 177 base pairs in length. The ~1.4-kilobase pair Ntan1 mRNA is expressed in all of the tested mouse tissues and cell lines and is down-regulated upon the conversion of myoblasts into myotubes. The Ntan1 promoter is located ~500 base pairs upstream of the Ntan1 start codon. The deduced amino acid sequence of mouse NtN-amidase is 88% identical to the sequence of its porcine counterpart, but bears no significant similarity to the sequence of the NTA1-encoded N-terminal amidohydrolase of the yeast Saccharomyces cerevisiae, which can deamidate either N-terminal asparagine or glutamine. The expression of mouse NtN-amidase in S. cerevisiae nta1Delta was used to verify that NtN-amidase retains its asparagine selectivity in vivo and can implement the asparagine-specific subset of the N-end rule. Further dissection of mouse Ntan1, including its null phenotype analysis, should illuminate the functions of the N-end rule, most of which are still unknown

The Polarized H and D Atomic Beam Source for ANKE at COSY-J\"ulich

A polarized atomic beam source was developed for the polarized internal storage-cell gas target at the magnet spectrometer ANKE of COSY-J\"ulich. The intensities of the beams injected into the storage cell, measured with a compression tube, are $7.5\cdot 10^{16}$ hydrogen atoms/s (two hyperfine states) and $3.9\cdot 10^{16}$ deuterium atoms/s (three hyperfine states). For the hydrogen beam the achieved vector polarizations are $p_{\rm z}\approx\pm0.92$. For the deuterium beam, the obtained combinations of vector and tensor ($p_{\rm zz}$) polarizations are $p_{\rm z}\approx\pm 0.90$ (with a constant $p_{\rm zz}\approx +0.86$), and $p_{\rm zz}=+0.90$ or $p_{\rm zz}=-1.71$ (both with vanishing $p_{\rm z}$). The paper includes a detailed technical description of the apparatus and of the investigations performed during the development.Comment: 18 pages, 26 figures, 4 table

Восстановление оттока желчи при повреждении гепатикохоледоха и несостоятельности билиобилиарного анастомоза после лапароскопической холецистэктомии

The aspect of injuring bile ducts during laparoscopic cholecystectomy is still of current concern. Causes of this complication include insufficient experience of surgical team, poor knowledge of topographic anatomy of subhepatic space, particularly when perivesical inflammatory infiltrate presents, inadequate approach conversion and so on. Most of patients with bile duct injuries undergo repeated operation in the same surgical unit where cholecystectomy was performed. In many cases, this results in a shortening of the segment of the common hepatic duct, which is favorable for restoration. Subsequent reconstructive surgery is usually performed in the worse conditions with a high risk of complications such as failure of sutures, biliary fistula, anastomotic stricture, etc. Most specialists recommend to abstain from primary reconstruction of the biliary tree in hospitals with no proper experience in hepatobiliary surgery and to perform only the external drainage of subhepatic space with subsequent admission of patient to a specialized clinic. We report a case of a young woman who suffered an excision of hepaticocholedochus fragment during laparoscopic cholecystectomy. A primary reconstructive surgery (hepatico-hepaticoanastomosis) was performed in the same clinic and resulted in external fistula of the common hepatic duct. The subsequent operation (hepaticoejunostomy) was performed in a specialized department of the regional clinical hospital. The woman underwent right-sided hypochondrium laparotomy with debridement of postoperative scar tissues. The stumps of common bile duct were mobilized in compact inflammatory infiltrate. The operation ended with distal stump closure and hepaticoenteroanastomosis formation. The patient was discharged with recovery. Six months later, her condition was satisfactory, and she was engaged in occupational activity.Проблема повреждений желчных протоков во время лапароскопической холецистэктомии не теряет свою актуальность. Причины осложнений: недостаточный опыт хирургической бригады, ограниченные знания топографической анатомии подпеченочного пространства, особенно в условиях перивезикального воспалительного инфильтрата, несвоевременная конверсия доступа и прочее.Большую часть больных с травмой желчных протоков повторно оперируют в хирургических отделениях, где выполняют холецистэктомию. Нередко это заканчивается несостоятельностью билиобилиарного анастомоза и приводит к укорочению перспективного для восстановления сегмента общего печеночного протока.Последующую реконструктивную операцию выполняют в худших условиях с высокой вероят­ностью различного рода осложнений (несостоятельность швов, желчный свищ, стриктура анастомоза и прочее). Большинство авторов рекомендуют воздержаться от первичных реконструкций билиарного дерева в стационарах без должного опыта гепатобилиарной хирургии и ограничиться санацией и наружным дренированием подпеченочного пространства с последующим направлением пациента в специализированные клиники. Представлено клиническое наблюдение лечения молодой женщины, которой во время лапароскопической холецистэктомии иссечен фрагмент гепатикохоледоха.В этой же клинике выполнена первичная реконструктивная операция (гепатикогепатикоанастомоз), после которой сформировался наружный свищ общего печеночного протока. Очередная операция проведена в специализированном отделении областной клинической больницы. Выполнена комбинированная правосторонняя подреберная лапаротомия с иссечением после­операционного рубца. В плотном воспалительном инфильтрате с напластованием фибрина мобилизованы культи общего печеночного протока. Дистальная культя ушита. Сформирован гепатикоэнтероанастомоз. Пациентка выписана с выздоровлением. При осмотре через 6 месяцев состояние удовлетворительное, работает по специальности

СРАВНИТЕЛЬНАЯ ОЦЕНКА ПРОГНОСТИЧЕСКОЙ ЗНАЧИМОСТИ ИСХОДНЫХ ЗНАЧЕНИЙ СЫВОРОТОЧНОГО ТЕСТОСТЕРОНА И ПРОСТАТСПЕЦИФИЧЕСКОГО АНТИГЕНА У БОЛЬНЫХ С ПОДОЗРЕНИЕМ НА РАК ПРЕДСТАТЕЛЬНОЙ ЖЕЛЕЗЫ

Prostate cancer (PC) is now one of the most common malignancies in elderly men. The level of prostate-specific antigen (PSA) as the most valuable prognostic tumor marker is estimated for the early detection of PC in practical health care. However, it has no strict specificity for PC and its low and threshold values do not allow prostate neoplasm to be ruled out.The objective of the investigation was to search for correlations between the level of testosterone, that of PSA, and prostate tissue morphological changes in patients with PC.Рак предстательной железы (РПЖ) в настоящее время является одним из наиболее широко распространенных злокачественных новообразований у мужчин пожилого возраста. Для раннего выявления РПЖ в практическом здравоохранении исследуется уровень простатспецифического антигена (ПСА) как наиболее ценного опухолевого маркера, имеющего прогностическую значимость. Однако он не обладает строгой специфичностью для РПЖ, и его низкие и пороговые значения не позволяют полностью исключить новообразование предстательной железы (ПЖ).Цель исследования — поиск корреляционных связей между уровнем сывороточного тестостерона, уровнем ПСА и морфологическими изменениями в ткани ПЖ у пациентов с РПЖ

Hospital epidemiology of abdominal adhesions

The purpose of the research was to establish main causes of development and outcomes of adhesive obstruction. We analyzed the outcomes of treatment of 154 patients with acute intestinal obstruction. The following data were taken into consideration: age, gender, surgeries in past medical history, terms of adhesions manifestations, clinical symptoms, findings of additional examinations, methods of treatment, outcome. It has been established, that the most frequent causes of adhesions were appendectomy (23 %), stomach operations (21 %) and gynecological interventions (14 %). After surgeries performed in conditions of regional hospitals, adhesions developed after appendectomy, gynecological operations and interventions on the intestine. In patients operated in city hospitals intestinal obstruction more often occurred after extensive operations on the stomach, appendix, and after gynecological interventions. Urgent surgical interventions more often led to adhesive process in the abdominal cavity (63 %). Mortality made 5.8 %. Causes of death were intestinal fistulas and abdominal sepsis. Thus, acute adhesive intestinal obstruction as an extreme form of abdominal adhesions continues to be an urgent medical issue

Circular resection of the trachea for cicatricial stenosis

The primary interventions for trachea in the thoracic surgery units are performed for the treatment of cicatricial stenosis of the trachea. Circular resection of the trachea is one of the treatment procedures in this pathology. The benefit of this method as compared to the others is that the resection with tracheo-tracheal anastomosis allows a one-stage recovery of patient with this pathology. The first successful resection of the trachea was performed in the late 19th century, and since then this surgery technique is constantly being improved. Several methods of suture placing in anastomosis surgery are proposed, different suture materials are used, special devices are developed to facilitate the anastomosis performing. There are several tactics depending on the presence or absence of tracheostome in the patient. Different methods are worked out to approximate the trachea ends with different diameters. Prevention of anastomosis leakage is achieved by strengthening the anastomosis area to reduce the suture tension. In addition, there are studies dealing with the improvement of trachea regeneration by physiotherapy impact on the anastomosis area. Laser therapy and hyperbaric oxygenation are also put forward for use. Nevertheless, a number of items remain to be solved: indications for circular resection of the trachea are not clearly formulated, the size of trachea fragment to be resect is the subject of active discussion

Joint PDF modelling of turbulent flow and dispersion in an urban street canyon

The joint probability density function (PDF) of turbulent velocity and concentration of a passive scalar in an urban street canyon is computed using a newly developed particle-in-cell Monte Carlo method. Compared to moment closures, the PDF methodology provides the full one-point one-time PDF of the underlying fields containing all higher moments and correlations. The small-scale mixing of the scalar released from a concentrated source at the street level is modelled by the interaction by exchange with the conditional mean (IECM) model, with a micro-mixing time scale designed for geometrically complex settings. The boundary layer along no-slip walls (building sides and tops) is fully resolved using an elliptic relaxation technique, which captures the high anisotropy and inhomogeneity of the Reynolds stress tensor in these regions. A less computationally intensive technique based on wall functions to represent boundary layers and its effect on the solution are also explored. The calculated statistics are compared to experimental data and large-eddy simulation. The present work can be considered as the first example of computation of the full joint PDF of velocity and a transported passive scalar in an urban setting. The methodology proves successful in providing high level statistical information on the turbulence and pollutant concentration fields in complex urban scenarios.Comment: Accepted in Boundary-Layer Meteorology, Feb. 19, 200

On bi-integrable natural Hamiltonian systems on the Riemannian manifolds

We introduce the concept of natural Poisson bivectors, which generalizes the Benenti approach to construction of natural integrable systems on the Riemannian manifolds and allows us to consider almost the whole known zoo of integrable systems in framework of bi-hamiltonian geometry.Comment: 24 pages, LaTeX with AMSfonts (some new references were added