Laboratory rivers adjust their shape to sediment transport.

An alluvial river builds its own bed with the sediment it transports; its shape thus depends not only on its water discharge but also on the sediment supply. Here we investigate the influence of the latter in laboratory experiments. We find that, as their natural counterpart, laboratory rivers widen to accommodate an increase of sediment supply. By tracking individual particles as they travel downstream, we show that, at equilibrium, the river shapes its channel so that the intensity of sediment transport follows a Boltzmann distribution. This mechanism selects a well-defined width over which the river transports sediment, while the sediment remains virtually idle on its banks. For lack of a comprehensive theory, we represent this behavior with a single-parameter empirical model which accords with our observations.

Boltzmann Distribution of Sediment Transport.

The coupling of sediment transport with the flow that drives it allows rivers to shape their own bed. Cross-stream fluxes of sediment play a crucial, yet poorly understood, role in this process. Here, we track particles in a laboratory flume to relate their statistical behavior to the self-organization of the granular bed they make up. As they travel downstream, the transported grains wander randomly across the bed's surface, thus inducing cross-stream diffusion. The balance of diffusion and gravity results in a peculiar Boltzmann distribution, in which the bed's roughness plays the role of thermal fluctuations, while its surface forms the potential well that confines the sediment flux.

Integrated care in ovarian cancer "IgV Ovar": results of a German pilot for higher quality in treatment of ovarian cancer.

INTRODUCTION: Late-stage ovarian cancer patient's survival depends on complete cytoreduction and chemotherapy. Complete cytoreduction is more often achieved in institutions with a case volume of >20 cases per year. The Integrated care program Ovar (IgV Ovar) was founded in 2005 and started recruiting in 2006 with 21 health insurances and six expert centers of ovarian cancer treatment as a quality initiative. Results of the pilot and outcomes of patients of three participating centers will be presented here. METHODS: Data of 1038 patients with ovarian cancer were collected. Adjuvant patients (n = 505) stage FIGO IIB-IV (n = 307) were analyzed for cytoreduction and survival. FIGO IIIC patients were analyzed separately. RESULTS: Median follow-up was 32.7 months. Progression-free survival (PFS) was 23.1 months and overall survival (OS) was 53.6 months for stage IIB-IV. Patients with FIGO IIIC were completely cytoreduced in 48 %. PFS was 21, 29 months if completely cytoreduced. OS was 47.4, 64.9 months if completely cytoreduced.D ISCUSSION: Although the IgV Ovar Rhineland proved to have some structural problems with recruitment and prospective data collection, cytoreduction rates and outcome of patients prove treatment of patients in expert centers is superior to the national and international mean. Therefore, a new quality initiative will be started to bring more awareness to women and to their gynecologists and general practitioners of just how important a good referral strategy is.

[Assessment of efficacy of reconstructive operations on carotid arteries in combination of stenosis and pathological tortuosity]. / Otsenka éffektivnosti rekonstruktivnykh operatsii na sonnykh arteriiakh v sochetanii stenoza i patologicheskoi izvitosti.

OBJECTIVE: The purpose of this study was to assess efficacy of reconstructive operations on carotid arteries in patients presenting with stenosis of the internal carotid artery (ICA) combined with its pathological tortuosity. MATERIAL AND METHODS: We analysed our experience in surgical treatment of 84 patients with pathological tortuosity of the ICA combined with atherosclerotic stenosis. The study included patients with ICA stenosis ≥60% (any type of the atherosclerotic plaque) and with any degree of cerebrovascular insufficiency (CVI), or with ICA stenosis <60% (type I-III atherosclerotic plaque) with degree II-IV CVI in a combination with either S- or C-shaped tortuosity of the ICA, kinking or coiling, with the linear blood flow rate ≥110 cm/s and turbulence of blood flow. Only six (7.1%) patients of the 84 (100%) presented with no clinical signs of CVI and were found to have a past medical history free from episodes of cerebral circulation impairments. The ratio of asymptomatic/symptomatic patients was as follows: in group 1 - 12 (58.7%)/19 (61.3%), in group 2 - 27 (81.8%)/6 (18.2%), and in group 3 - 10 (50%)/10 (50%). RESULTS: Six months after surgery, the asymptomatic/symptomatic patients ratio was as follows: in group 1 - 22 (70.9%)/9 (29.1%), in group 2 - 28 (84.8%)/5 (15.2%), p=0.045, and in group 3 - 9 (45%)/11 (55%), p=0.024. In group 3, one (5%) patient developed thrombosis of the reconstruction zone with the development of ischaemic-type acute cerebral circulation impairment. Twelve months after surgery the ratio in the groups did not change. Of twelve patients with degree IV chronic CVI, four (33.3%) were found to have partial regression of the focal neurological symptomatology. CONCLUSION: Surgical method of treatment of patients with ICA stenos combined with pathological tortuosity proved efficient and safe both for asymptomatic patients and patients with clinical manifestations of CVI. Significantly better results were observed in the group subjected to eversion carotid endarterectomy with resection of the excessive ICA, with brining down and reimplantation into the ostium as compared with carotid endarterectomy with a patch and as compared with ICA resection with prosthetic repair.

[Results of surgical treatment of patients with internal carotid artery kinking depending on methods of its reconstruction].

It was analyzed the results of surgical treatment of 60 patients with internal carotid artery kinking operated in the department of vascular surgery of acad. B.V. Petrovsky Russian Scientific Center of Surgery of RAN. Indications for surgery included symptoms of cerebrovascular insufficiency (CVI) and instrumentally confirmed hemodynamically significant kinking of ICA. Criteria for surgical treatment were linear flow velocity gradient more than 2 and turbulent blood flow in the kinking segment diagnosed by ultrasonic scanning. All patients were divided into 2 groups depending on methods of surgery. The first group included 36 (60%) patients who underwent resection of ICA with orifice bringing down. The second group included 8 (13%) patients after ICA replacement and 16 (27%) cases with eversion endarterectomy, resection of ICA and orifice bringing down. The analysis of immediate surgery results did not reveal significant differences in dynamics of CVI and velocity parameters in reconstructed ICA (p>0.05). The index "stroke+mortality from stroke" was higher in the second group (p<0.05). Thrombosis of ICA reconstruction area has been developing more frequent (p<0.05) after ICA replacement (8%) in comparison with resection of ICA with orifice bringing down (0) and eversion endarterectomy, resection of ICA and orifice bringing down (0). Our data show that resection of ICA with orifice bringing down is preferable for surgical treatment of ICA kinking. ICA replacement is associated with significantly more frequent complications. Eversion endarterectomy with resection of ICA is optimal in case of combination of kinking with stenosis of ICA.

[Immediate and remote results of surgical treatment of patients presenting with pathological tortuosity of internal carotid arteries and accompanying ocular ischaemic syndrome].

The article deals with the data concerning the efficacy of reconstructive operations and conservative treatment in patients presenting with pathological tortuosity of internal carotid arteries. The study included a total of 63 patients. The diagnostic algorithm was as follows: studying the haemodynamics of the internal carotid arteries, assessing the neurological status, and the methods of examining the eye. The patients were subdivided into two groups: Group One consisted of operated on patients (n=37) and Group Two comprising patients treated conservatively (n=26). The patients according to the neurological status were subdivided as follows: an asymptomatic course in 25 (39.7%) patients, transitory ischaemic attacks in 18 (28.6%) patients, dyscirculatory encephalopathy in 12 (19 %) patients, and stroke in 8 (12.7%) patients. Ophthalmological symptomatology was predominantly manifested by fits of amaurosis fugax in 19 (30.2%) patients and processes of maculodystrophy in 49 (77.8 %) patients. We assessed the immediate (day 30) and remote (1 year) results of conservative and surgical treatment. Group One patients demonstrated cessation of the amaurosis fugax attacks, improvement of the acuity of vision by 0.1 and more, enlargement of the borders of the field of vision, disappearance of scotomas, as well as arrest of the processes of maculodystrophy. Patients with transitory ischaemic attacks and dyscirculatory encephalopathy changed to the category of asymptomatic patients. In Group Two patients the dynamics of the neurological status was negative and the patients continued to experience fits of amaurosis fugas. The dynamics of the opthalmological symptomatology was weakly pronounced.

[Comparative analysis of the outcomes of surgical and conservative treatment of patients with pathological kinking of carotid arteries].

OBJECTIVE: The study was aimed at comparatively analysing the results of surgical and conservative treatment of patients with pathological kinking of carotid arteries in order to determine the indications for operative treatment of patients presenting with the pathology concerned. PATIENTS AND METHODS: Analysed herein are the outcomes of managing a total of 75 patients presenting with pathological kinking of the internal carotid artery. Of these, 43 (57,4%) patients were operated on, with a total of 48 interventions performed. A further 32 (42,6%) patients underwent conservative treatment. In the group of operated patients (Group I), an asymptomatic course of pathological tortuosity was encountered in 19 (44,2%) patients, and 24 (35,8%) patients were found to have various-degree cerebrovascular insufficiency. The group of non-operated patients (Group II) consisted of 15 (46,8%) asymptomatic and 17 (53,2%) symptomatic patients. Also discussed are variants of reconstruction of the deformed carotid arteries. RESULTS: The immediate outcomes were studied within the terms of 30 days. Positive dynamics of the neurological status was observed in both groups. In Group One, 38 (88,3%) patients (p < 0,05) of the 43 followed-up patients became symptom-free, and in Group Two, out of the 32 patients, twenty-four (75%) were found to have an asymptomatic course. However, in the remote period (the follow-up term varying from 12 months, 3 and 5 years), positive dynamics of the neurological status was observed in 33 (80,4%) of 41 patients within the follow-up terms up to 5 years), whereas in the Group of non-operated patients it was seen only in 11 (42,3%) of 26 patients (within the follow-up terms up to 5 years) (p < 0,05). CONCLUSION: Surgical management of patients for pathological kinking of the internal carotid artery is an effective method of preventing progression of cerebrovascular insufficiency in the carotid basin in initially asymptomatic and symptomatic patients, which has been confirmed by the obtained short- and long-term outcomes of the operations in patients with the pathology concerned.

Ebstein's anomaly of the tricuspid valve in association with tetralogy of fallot and absent pulmonary valve syndrome.

Ebstein's anomaly and absent pulmonary valve syndrome belong to the rarest congenital heart defects. Their association has never been reported so far. We present the unusual case of a fetus at 23 weeks of gestation with Ebstein's anomaly, tetralogy of Fallot, absent pulmonary valve and agenesis of the arterial duct. The main diagnostic features were apical displacement of the septal leaflet of the tricuspid valve with an offset from the mitral valve of 8 mm, a pronounced atrialization of the right ventricle, a large malalignment ventricular septal defect with overriding aorta in combination with absence of the pulmonary valve leaflets, to and fro flow pattern over the stenotic pulmonary valve annulus, turbulent flow in the pulmonary trunk, massive dilatation of the pulmonary trunk plus the pulmonary arteries and a right aortic arch with retroesophageal course of an aberrant left subclavian artery. The arterial duct and the thymus were absent. The remaining fetal anatomy was unremarkable. Amniocentesis revealed a normal male karyotype; 22q11 microdeletion was ruled out. After being counseled on the unfavorable prognosis, the parents opted for termination of pregnancy. The prenatal cardiac findings were confirmed at autopsy; however, a severely hypoplastic thymus was found instead of the suspected aplasia.

Detection of oxygen isotopic anomaly in terrestrial atmospheric carbonates and its implications to Mars.

The debate of life on Mars centers around the source of the globular, micrometer-sized mineral carbonates in the ALH84001 meteorite; consequently, the identification of Martian processes that form carbonates is critical. This paper reports a previously undescribed carbonate formation process that occurs on Earth and, likely, on Mars. We identified micrometer-sized carbonates in terrestrial aerosols that possess excess (17)O (0.4-3.9‰). The unique O-isotopic composition mechanistically describes the atmospheric heterogeneous chemical reaction on aerosol surfaces. Concomitant laboratory experiments define the transfer of ozone isotopic anomaly to carbonates via hydrogen peroxide formation when O(3) reacts with surface adsorbed water. This previously unidentified chemical reaction scenario provides an explanation for production of the isotopically anomalous carbonates found in the SNC (shergottites, nakhlaites, chassignites) Martian meteorites and terrestrial atmospheric carbonates. The anomalous hydrogen peroxide formed on the aerosol surfaces may transfer its O-isotopic signature to the water reservoir, thus producing mass independently fractionated secondary mineral evaporites. The formation of peroxide via heterogeneous chemistry on aerosol surfaces also reveals a previously undescribed oxidative process of utility in understanding ozone and oxygen chemistry, both on Mars and Earth.

[On the occasion of the 20th anniversary of the accident on the Chernobyl NPP: medical consequences in Armenia].

The aim of this work is the analysis of the indices of the health and of the structure of the sicknesses of the inhabitants of Armenia who took part in the liquidation of the consequences of the Chernobyl accident. Also it is the determination of possible dependence of the frequency of diseases for the most widespread classes of sicknesses on the received dose of the irradiation, according to the data of the clinical examination and dispensarysation; and also it is the revelation of the role of other factors influenced on the health indexes.

[Lumbar sympathectomy in treatment of obliterating diseases of lower limbs: state of the art]. / Primenenie poiasnichnoi simpatéktomii v lechenii obliteriruiushchikh zabolevanii arterii nizhnikh konechnostei -- sovremennyi vzgliad na problemu.

The article deals with analysing examination and surgical treatment of 80 patients with predominant lesions to the distal arterial bed of the lower extremities, who were operated on at the RRSC from 1996 to 2003 with various degree on the background of chronic obliterating diseases of lower limbs arteries. All the patients were subdivided into two groups according to the outcomes of the epidural block: Group I -- with positive outcomes consisted of 36 (45 %) patients, and Group II -- with a negative outcome -- included 44 (55 %) patients. The patients from the both groups underwent the following operations: lumbar sympathectomy combined with direct and indirect methods of revascularisation, as well as lumbar sympathectomy as an independent therapeutic method. To solve the problem concerning feasibility of either done, or concomitant lumbar sympathectomy, we devised assessment of microcirculation state (alterations in volumetric blood flow indices in epidural block in relation to the indices at rest, as well as in the immediate or remote postoperative period) and peripheral haemocirculation (dynamics of the onkle brachial index values on the background of epidural block test, nitroglycerine test in relation to the ARI at rest both in the short-, and long-term postoperative period) by data of scintigraphy and dopplerography of the lower limbs.

[A present-day variant of intermitttent replacement renal therapy in patients with multiple organ failure after cardiovascular surgery]. / Sovremennyi variant intermittiruiushchei zamestitel'noi pochechnoi terapii u bol'nykh s sindromom poliorgannoi nedostatochnosti posle operatsii na serdtse i sosudakh.

The efficiency of "semi-prolonged" replacement renal therapy (RRT) was assessed in patients with multiple organ dysfunction (MOD) after cardiovascular surgery. The results of semiprolonged RRT are analyzed in 65 patients (36-69 years, mean age 52.4 +/- 15.7 years, body weight 57-105 kg, mean 79.4 +/- 21.6 kg) operated on at A. N. Bakulev Cardiovascular Surgery Center, Russian Academy of Medical Sciences. Bicarbonate hemodialysis (BHD) was carried out in 50 patients, on-line hemodiafiltration (HDF) in the rest patients. Interventions on the heart and vessels of different complexity were carried out. The results indicate that semiprolonged SRT in complex with intensive care measures notably reduced the mortality of patients with MOD and improved the survival rate in this category of patients. Semiprolonged RRT is an effective method, which can and should be used in critical patients. This method meets all the requirements to modern RRT and ensures adequate filtration of nitrous metabolism products, corrects water-electrolyte and acid base balance, allows infusion/transfusion therapy and parenteral nutrition, and has no negative impact on the hemodynamic values, which is particularly important after cardiovascular interventions.

Tumor suppressor gene Smad4/DPC4, its downstream target genes, and regulation of cell cycle.

The tumor suppressor gene deleted in pancreatic cancer locus 4 (Smad4/DPC4) is inactivated in about 50% of pancreatic adenocarcinomas. The role of DPC4 in the transforming growth factor-beta (TGF-beta) receptor-mediated signal transduction cascade in human pancreatic, colon, and breast carcinoma cell lines has been investigated by a number of laboratories. The results demonstrate that Smad4/DPC4 protein functions as a key transcription factor required in regulation of TGF-beta inducible gene expression and subsequent growth inhibition. Many transcription regulators that are involved in cell growth, differentiation, and oncogenesis have been identified and cloned. Yet paradoxically, it is much more difficult to identify the important downstream target genes responsible for the biological effects elicited by these transcription factors. Although numerous attempts have been made and different approaches have been used to identify the target genes, only limited success has been achieved. Our data show that p21waf1 is one of the Smad4/DPC4-regulated downstream target genes and suggest that overexpression of the Smad4/DPC4 gene can bypass TGF-beta receptor activation and reestablish one of the key regulatory controls of cell proliferation. Identification of the Smad-regulated downstream target genes responsible for diverse biological processes that they control will extend our understanding of the mechanism for cell cycle regulation and cell differentiation.

Overexpression of the tumor suppressor gene Smad4/DPC4 induces p21waf1 expression and growth inhibition in human carcinoma cells.

The Smad4/DPC4 protein functions as a key transcription factor in transforming growth factor beta (TGF-beta) signaling pathways. However, the downstream target genes regulated by Smad4/DPC4 have not been identified until now. We previously demonstrated that the loss of TGF-beta-induced p21waf1 expression and growth inhibition correlates with inactivation of the Smad4/DPC4 gene. Now we show that transient overexpression of Smad4/DPC4 can induce p21waf1 expression, specific Smad4 DNA binding activity, SBE4-luc reporter gene activity, and subsequent growth inhibition in Smad4/DPC4-null cells and other carcinoma cells in the presence or absence of TGF-beta. Taken together, these data show that p21waf1 is one of the Smad4/DPC4-regulated downstream target genes and suggest that overexpression of the Smad4/DPC4 gene can bypass TGF-beta receptor activation and reestablish one of the key regulatory controls of cell proliferation.