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Cephalic arch stenosis is a common complication in maintenance hemodialysis (MHD) patients with brachial artery-cephalic vein fistulas and frequently leads to loss of the functioning brachial artery-cephalic vein fistula. There is paucity of conclusive data to guide appropriate management. We examined the risk of recurrence of cephalic arch stenosis after angioplasty compared to angioplasty after stent placement determined by angiography of the involved upper extremity over time in a contemporary cohort of MHD patients treated in two interventional nephrology practices from March 2008 through May 2011. We retrospectively identified 45 MHD patients with evidence of cephalic arch stenosis (age 60 ± 30 years, 45% men) on elective angiograms. The median number of days until another angioplasty was required decreased, starting with a median of 91.5 days after the first, 70.5 days after the second, 85 days after the third, and 56 days after the fourth. Angioplasty is associated with a faster rate of recurrence of cephalic arch stenosis. The placement of intravascular stent seems to prolong the patency compared to angioplasty alone. Clinical trials with a larger sample size will better elucidate the value and timing of angioplasty versus stent placement in cephalic arch stenosis.

Pyrrolidinolysis and piperidinolysis of O-aryl oximes show third order dependence on amine with no uncatalytic route. The effect of temperature on separate routes and overall rate is reported and explained. [ABSTRACT FROM AUTHOR]

Abstract Background Obesity is a growing health issue in the Western world. Obesity, as part of the metabolic syndrome adds to the morbidity and mortality. The incidence of diabetes and hypertension, two primary etiological factors for chronic renal failure, is significantly higher with obesity. We report a case with morbid obesity whose renal function was stabilized with aggressive management of his obesity. Case report A 43-year old morbidly obese Caucasian male was referred for evaluation of his chronic renal failure. He had been hypertensive with well controlled blood pressure with a body mass index of 46 and a baseline serum creatinine of 4.3 mg/dl (estimated glomerular filtration rate of 16 ml/min). He had failed all conservative attempts at weight reduction and hence was referred for a gastric by-pass surgery. Following the bariatric surgery he had approximately 90 lbs. weight loss over 8-months and his serum creatinine stabilized to 4.0 mg/dl. Conclusion Obesity appears to be an independent risk factor for renal failure. Targeting obesity is beneficial not only for better control of hypertension and diabetes, but also possibly helps stabilization of chronic kidney failure.

Terminally ill patients requiring dialysis present complex ethical and medical dilemma to the nephrologists. With the rising health care costs and futility of care in such cases, the financial burden is a lingering concern. We describe a 77-year-old male with lymphoma and prostate cancer admitted for abdominal pain and weight loss. He was found to have metastatic pancreatic adenocarcinoma on laparotomy. His malignancy was deemed inoperable and was offered palliative care. Subsequent hospital course was complicated by sepsis with multiple organ failure resulting in acute renal failure requiring dialysis support. Being aware of his poor prognosis, patient initially declined interventions including dialysis. He was later convinced by his family and agreed to aggressive therapeutic intervention. Anticipating a complicated course, hemodialysis was initiated through cuffed tunneled catheter (CTC). Subsequently, he had multiple episodes of sepsis resulting in removal of CTC, necessitating insertion of 9 temporary dialysis catheters and 3 CTC over a 9-month period; further complicated by thrombosis of both femoral veins. Eventually, patient's condition progressively deteriorated and dialysis was withdrawn with family's consent 9 months following surgery. Patient was put on comfort care and died 2 days later. He spent a total of 7½ months in ICU, 1 month in skilled care facility, and 2 weeks on regular hospital floor. Total VAMC expenditure was $373,964, which in a private setting would be approximately $1.0 million. This case highlights the futility of aggressive management of renal failure in terminally ill elderly patients. Besides its inability to improve quality of life, it adds as a financial burden to the society. [ABSTRACT FROM AUTHOR]

Renal failure in elderly patients often generates an ethical question “should dialysis be initiated?” The nephrologists are faced with the dilemma of conveying the prognosis of renal failure in elderly patients and also explain the pros and cons of offering a renal replacement therapy (RRT). We report a retrospective study conducted between 6/2001 and 6/2003 to evaluate the clinical situations where initiating RRT was considered inappropriate. All patients who opted for not initiating/withdrawal of RRT were included in the study. Twenty-four patients were included in the study. All patients were males with average age 70.7 years. 17/24 were in the intensive care unit. Complex medical illnesses with poor quality of life were the major reasons for opting out of RRT. 20/24 patients opted for not initiating RRT and 3/24 patients opted for withdrawal. 1/24 opted for a trial of RRT before taking long-term decisions. 3/20 who opted against initiating RRT had advanced directives. 18/20 who opted for not initiating RRT died within 3 days of the need for RRT, 2/20 are alive without RRT after 6 and 4 months with estimated GFR of 14 and 12 mL/min, respectively. Patient who opted for a trial of RRT died eventually, 4 months after a prolonged bedridden stay in a nursing home. 3/3 ESRD patients died within a week after withdrawing dialysis. The decision to initiate RRT should be made considering the overall prognosis. A decision to not initiate or withdraw RRT is possible in critically ill patients and if taken judiciously can reduce physical and mental stress of both patient and their family members. [ABSTRACT FROM AUTHOR]

In the present study, the effect of irradiance on growth performance of Scenedesmus obliquus was investigated, and various non-linear growth models were evaluated to predict its temporal evolution. This microalga was cultured in a LED-illuminated flat-panel gas-lift photobioreactor operated in batch mode at varying irradiance ranging from 50 to 200 µmol/m 2 /s keeping all the other physico-chemical parameters constant. When growth data in terms of optical density were fitted in sigmoidal growth models, three non-linear models, namely, Richards model, Gompertz model, and logistic model, were found to be the best fit. Comparing these models based on statistical information, the logistic model could more appropriately and precisely describe algal growth under varying light intensity. Finally, the parameters of the logistic model were determined using regression analysis and were incorporated in the logistic equation to investigate the kinetic characteristics of S. obliquus. The optimum light intensity (I opt ) for growth was found to be 150 µmol/m 2 /s, at which a maximum specific growth rate (µ opt ) of 0.35/day was obtained. The model developed was validated experimentally and could successfully explain the photo-inhibition phenomenon occurring at light intensity above 150 µmol/m 2 /s.

A decade since the availability of Mycobacterium tuberculosis (Mtb) genome sequence, no promising drug has seen the light of the day. This not only indicates the challenges in discovering new drugs but also suggests a gap in our current understanding of Mtb biology. We attempt to bridge this gap by carrying out extensive re-annotation and constructing a systems level protein interaction map of Mtb with an objective of finding novel drug target candidates. Towards this, we synergized crowd sourcing and social networking methods through an initiative 'Connect to Decode' (C2D) to generate the first and largest manually curated interactome of Mtb termed 'interactome pathway' (IPW), encompassing a total of 1434 proteins connected through 2575 functional relationships. Interactions leading to gene regulation, signal transduction, metabolism, structural complex formation have been catalogued. In the process, we have functionally annotated 87% of the Mtb genome in context of gene products. We further combine IPW with STRING based network to report central proteins, which may be assessed as potential drug targets for development of drugs with least possible side effects. The fact that five of the 17 predicted drug targets are already experimentally validated either genetically or biochemically lends credence to our unique approach.

Accidental loss of tunneled hemodialysis catheters has been observed in chronic hemodialysis patients. Although a new catheter could be inserted using a fresh site, catheter insertion can also be accomplished by utilizing the existing exit site. In this analysis, we report 10 cases of an extruded tunneled hemodialysis catheter. The catheters had been in place for 2-6 months. The time elapsed after catheter extrusion ranged from 6 to 72 hours. None of the patients demonstrated any evidence of exit site or tunnel infection. Patient age ranged from 45 to 77 years. Diabetes mellitus was the cause of renal failure in 40% of the cases. Catheter insertion was accomplished by inserting a guidewire into the exit site and navigating it through the tunnel to the central venous system and into the right atrium. A diagnostic catheter was then navigated over the wire and contrast study performed to confirm the position. The wire was reinserted and a new tunneled hemodialysis catheter fed over the wire and into the atrium. Nine catheters were successfully placed using this technique. One patient had nausea and hiccups upon wire insertion into the atrium. There were no hemodynamic consequences. The wire was removed and a new catheter inserted on the other side using the left internal jugular vein. All of the catheters inserted using this technique functioned appropriately. There were no exit site or tunnel infections for up to 4 weeks' follow-up. We conclude that patients with catheter extrusion can receive a new catheter through the existing exit site, tunnel, and venotomy.

Calculation of dose of haemodialysis using blood-based modelling is subject to controversies as it is based on unrealistic assumptions. This paper proposes the use of dialysate-based modelling by SVMs to calculate the delivered dose of dialysis. The authors use the solute removal index (SRI), which is correlated to the amount of urea removed, for calculating the dose. The SVM model was trained to recognise the evolution of weight, blood urea nitrogen concentration and solute removal index with respect to time and then used to predict the solute removal index. When the estimated SRI values were compared to the actual SRI values determined by the standard method, the prediction errors were small. This paper is the first demonstration that SVM regression can predict delivered dose of haemodialysis with a clinically acceptable accuracy. The result is an effective technique that will offer the physician a better guide to the monitoring and prescription of haemodialysis therapy thereby reducing the mortality rate among patients.