Recurrence networks to study dynamical transitions in a turbulent combustor.

Thermoacoustic instability and lean blowout are the major challenges faced when a gas turbine combustor is operated under fuel lean conditions. The dynamics of thermoacoustic system is the result of complex nonlinear interactions between the subsystems-turbulent reactive flow and the acoustic field of the combustor. In order to study the transitions between the dynamical regimes in such a complex system, the time series corresponding to one of the dynamic variables is transformed to an ε-recurrence network. The topology of the recurrence network resembles the structure of the attractor representing the dynamics of the system. The transitions in the thermoacoustic system are then captured as the variation in the topological characteristics of the network. We show the presence of power law degree distribution in the recurrence networks constructed from time series acquired during the occurrence of combustion noise and during the low amplitude aperiodic oscillations prior to lean blowout. We also show the absence of power law degree distribution in the recurrence networks constructed from time series acquired during the occurrence of thermoacoustic instability and during the occurrence of intermittency. We demonstrate that the measures derived from recurrence network can be used as tools to capture the transitions in the turbulent combustor and also as early warning measures for predicting impending thermoacoustic instability and blowout.

A Study of Estimated Glomerular Filtration Rate in Patients Undergoing Diagnostic or Interventional Coronary Contrast Procedures.

Introduction: Angiographic procedures are underused in patients with chronic kidney disease (CKD), who present with acute coronary syndromes, due to risk of contrast-induced acute kidney injury (CI-AKI). In this study, we assessed the change in estimated glomerular filtration rate (eGFR) over 3 months following coronary procedures in CKD patients. Methods: This observational study was done from July 2017 to January 2019 in patients undergoing elective coronary procedures with an eGFR <60 mL/min/1.73 m2. CKD-EPI equation was used to calculate eGFR pre and post coronary procedure at 24, 48, and 72 hours as well as 30, 90 days. AKI was diagnosed and patients were given prophylaxis for CI-AKI as per KDIGO recommendation (intravenous normal saline and oral N-acetyl cysteine). Results: Patients studied were 282 (225 males, 57 females) of which 68.1% were diabetics. Mean eGFR was 42.91 ± 10.51 mL/min/1.73 m2 and mean hemoglobin was 12.08 ± 1.51 gm/dL. Coronary angiogram (CAG) was done in 174; percutaneous transluminal coronary angioplasty (PTCA) was done in 108. Mean contrast volume in CAG was 55.17 ± 34.45 mL and in PTCA was 156.94±±47.99 mL. CI-AKI was seen in 66 (23.4%) patients. The incidence of CI-AKI increased with severity of underlying CKD. The variability of eGFR at 1 and 3 months after coronary procedures showed no significant change from baseline, even in the patients who developed CI-AKI. Conclusions: CI-AKI is self-limiting and has no major detrimental effects on eGFR at 1 and 3 months after contrast exposure.

Physical exercise for cancer patients with advanced disease: a randomized controlled trial.

BACKGROUND: Physical exercise can improve cancer patients' functioning and reduce their symptom levels. A randomized, controlled trial was launched to test the hypothesis that physical exercise reduces fatigue and improves physical performance in cancer patients with advanced and incurable disease. METHODS: Cancer patients (n = 231) with a life expectancy ≤2 years were randomized to a physical exercise group (PEG, n = 121) or a control usual care group (UCG, n = 110). The PEG exercised under supervision 60 minutes twice a week for 8 weeks. Assessments were performed before and after the intervention. The primary outcome was physical fatigue (PF) measured by the Fatigue Questionnaire. Physical performance was a secondary outcome measured by the Shuttle Walk Test (SWT) and hand grip strength (HGS) test. Analyses were performed after multiple imputations for missing data. The trial is registered with ClinicalTrials.gov (identifier, NCT00397774). FINDINGS: Thirty-six percent of the PEG were lost to follow-up compared with 23% of the UCG, primarily as a result of disease progression. Seventy-eight PEG and 85 UCG patients completed the intervention. Analyses showed no significant between-group effects in PF. However, clinically and statistically significant between-group effects were found for the SWT and HGS test. INTERPRETATION: Fatigue was not reduced but physical performance (SWT and HGS test) was significantly improved after 8 weeks of physical exercise. Physical exercise might therefore be a suitable approach for maintaining physical capacity in cancer patients with incurable and advanced disease.

Colistin Nephrotoxicity-Age and Baseline kidney Functions Hold the Key.

INTRODUCTION: With the emergence of multidrug-resistant gram-negative bacterial infections, there has been a surge in the use of Colistin in recent times. The most important side effect of Colistin use is its nephrotoxicity. The study was designed to assess the effect on kidney function and the risk factors for nephrotoxicity in patients treated with Colistin. METHODS: The study is a retrospective one, which included patients who received Colistin for more than 48 hours. The estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) four-variable equation and acute kidney injury (AKI) was diagnosed as per the Kidney Disease Improving Global Outcome (KDIGO) criteria. RESULTS: Of the 150 patients studied, 59 patients (39.2%) developed AKI within a median period of 4 days (Range 2-20 days) of initiation of Colistin. Age, eGFR at the start of therapy and requirement of vasopressor support for treatment of septic shock were the most important risk factors associated with nephrotoxicity. Among patients with AKI, nearly half had only mild worsening of renal functions to KDIGO AKI stage 1. Nearly 75% of patients with AKI had complete or partial recovery of renal functions after stopping Colistin. CONCLUSION: Colistin has significant nephrotoxicity, the risk being higher with older age and baseline renal dysfunction. It is important to monitor renal functions early and at regular intervals after initiating therapy.

Robotic assisted kidney transplantation in grafts with multiple vessels: single center experience.

INTRODUCTION: The aim of this study was to assess the feasibility of robotic assisted kidney transplantation in graft with multiple vessels. MATERIALS AND METHODS: Eighteen patients underwent RAKT with grafts with multiple vessels (GMVs) from living donor performed by a single surgeon in single institution. The retrospective data obtained were compared to patients who underwent robotic assisted kidney transplant (RAKT) with single vessel and also open kidney transplant with GMVs. RESULTS: There were no significant differences in graft function outcome and perioperative parameters in all three groups. In comparison with OKT in GMVs we found that RAKT with GMVs had less pain score on post op 4th day. There was also a significant difference in mean analgesic requirement and incision length. CONCLUSION: With increasing experience, grafts with challenging vascular anatomy can be taken up for RAKT and GMVs should not be considered as a contraindication for RAKT.

Naproxen Induced Acute Interstitial Nephritis with Renal Cortical Necrosis.

Drug induced acute interstitial nephritis is an idiosyncratic reaction following a drug exposure. The commonest drugs implicated are nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics and proton pump inhibitors. Renal cortical necrosis is a rare cause of acute kidney injury caused by severe and sustained vasoconstriction of small renal vessels. There is a change in the epidemiology of acute kidney injury especially in developing countries where drug induced acute kidney injury is becoming increasingly common. Naproxen is known to cause renal failure by renal papillary necrosis, tubular damage and acute interstitial nephritis. We present a case of Naproxen induced acute interstitial nephritis with acute cortical necrosis. To the best of our knowledge this is the first documented case of Naproxen induced renal cortical necrosis.

Ileal Tuberculosis Causing Hypercalcemia and Renal Failure.

Hypercalcemia rarely causes acute pancreatitis due to secretory block in the pancreas and damage by accumulated proteases. Hypercalcemia, though described in granulomatous disorders, is uncommon in tuberculosis. Acute kidney injury is known to occur with acute pancreatitis, secondary to sepsis and septic shock; however, acute pancreatitis resulting in acute cortical necrosis is very rare. We report a 22-year-old woman, who presented with pain abdomen and vomiting. She was found to have features of acute pancreatitis, both biochemically and radiologically. She had hypercalcemia on presentation and this was attributed to be the cause for pancreatitis as other causes were ruled out. 1, 25-dihydroxyvitamin D level was high with normal parathyroid hormone level. Whole-body positron emission tomography-computed tomography showed increased fluorodeoxyglucose uptake in the terminal ileum and histology from that area showed noncaseating granuloma with acid-fast bacilli in the tissue. She was treated with antituberculosis therapy; hypercalcemia improved over a period of time and pancreatitis resolved. She developed anuric renal failure, and kidney biopsy showed patchy acute cortical necrosis. She is dialysis dependent at the end of 6 months. To the best of our knowledge, this is the first case report of a patient with ileal tuberculosis presenting with hypercalcemia and acute pancreatitis. This case is reported due to the rarity of extrapulmonary tuberculosis presenting with symptomatic hypercalcemia, acute pancreatitis, and acute renal cortical necrosis.

Networks of coactive neurons in developing layer 1.

Spontaneous neuronal activity plays an important role in the development of cortical circuitry, yet its spatio-temporal dynamics are poorly understood. Cajal-Retzius (CR) neurons in developing layer 1 are necessary for correct cortical lamination and are strategically located to coordinate early circuit activity. To characterize the spontaneous activity of CR and other layer 1 neurons during cortical development, we imaged calcium transients in populations of layer 1 neurons in hemispheres and slices from postnatal rat somato-sensory neocortex. The spontaneous activity in layer 1 had complex spatio-temporal patterns. Groups of non-CR cells showed synchronous activations and formed networks of correlated neurons superimposed in the same territory. Correlated activity among non-CR cells was mediated by a depolarizing effect of GABA and was modulated by glutamate, probably released by CR cells. Our findings demonstrate that developing layer 1 can sustain complex patterns of correlated activity and reveal a circuit mechanism that can mediate this patterned activity.

Essential roles in synaptic plasticity for synaptogyrin I and synaptophysin I.

We have generated mice lacking synaptogyrin I and synaptophysin I to explore the functions of these abundant tyrosine-phosphorylated proteins of synaptic vesicles. Single and double knockout mice were alive and fertile without significant morphological or biochemical changes. Electrophysiological recordings in the hippocampal CA1 region revealed that short-term and long-term synaptic plasticity were severely reduced in the synaptophysin/synaptogyrin double knockout mice. LTP was decreased independent of the induction protocol, suggesting that the defect in LTP was not caused by insufficient induction. Our data show that synaptogyrin I and synaptophysin I perform redundant and essential functions in synaptic plasticity without being required for neurotransmitter release itself.

Hemodialysis outcomes and practice patterns in end-stage renal disease: Experience from a Tertiary Care Hospital in Kerala.

This study was planned to analyze the hemodialysis practice patterns from a tertiary care referral centre as there is very limited data from India. All patients of ESRD on maintenance hemodialysis (MHD) in dialysis unit at AIMS, Kochi, Kerala for a minimum period of 3 months were included. A total of 134 patients (M: F 2:1) with age of 20 to 84 years (Mean: 59.83; SD: 11.98) were studied. The most common causes of ESRD in study population were diabetic nephropathy (DN) (59.7%) followed by unclassified group (19.4%), chronic glomerulonephritis (CGN) (11.9%). Majority (81%) were initiated on MHD through temporary vascular access on emergency basis. Majority (79%) of the patients were on twice weekly MHD. The range of eGFR (ml/min/1.73 m2) at the time of initiation of MHD was 1.26-11.78 by CG formula and 2.18-16.4 by MDRD equation. The mean duration on hemodialysis was 37.16 months and 50.7% patients had died during the follow-up period (3-108 months). The mean survival time on hemodialysis was 40.31 months (SD = 26.69). The mean survival time was lower in diabetic nephropathy (35.93 months) than in non-diabetic renal disease (47.46 months). The most common causes of deaths were cardiovascular events (51.5%), and infections (26.5%). In conclusion, males outnumbered females, among those on hemodialysis. There was no significant difference in eGFR at initiation of MHD based on etiologies. Initiation of MHD via temporary access, presence of LVH, acute coronary syndrome, use of acetate dialysate, need for parenteral iron therapy had impact on mortality. Survival rates while on hemodialysis at end 1st, 3rd, 5th and 7th years were 87.31, 45.52, 21.64 and 7.46 percentages respectively.

Progression to end stage renal disease in post-streptococcal glomerulonephritis (PSGN)---Chandigarh Study.

193 patients (142 adults and 51 children) with acute PSGN were followed long term. Sixty percent had elevated serum creatinine and 14% had nephrotic range proteinuria at the onset. By two years 28 patients (14%) had died from uremia, and 19 were lost to follow up. Amongst the remainder, 8 patients (4%) had developed mild to moderate renal insufficiency, 12% were hypertensive, and 22% had urinary abnormalities. Of the 146 patients alive at 2 years, 107 were followed up to 10 years (mean 4.8 years). In addition to the 8 patients with renal insufficiency at 2 years, another 7 developed renal failure subsequently. Four out of these 15 patients progressed to uremia within 4 to 10 years after the onset of disease. Hypertension and persistent urinary abnormalities were present in 15% and 24% respectively. Progression to uremia occurred in 6% of children and 20% of adults. Nephrotic range proteinuria, renal insufficiency at the onset, and crescents in more than one third of glomeruli indicated a poor prognosis.

Acute renal failure amongst children in a tropical environment.

The pathogenetic factors leading to acute renal failure (ARF) in 223 children between the ages of 20 days and 14 years were studied. Diarrhoeal diseases were responsible for ARF in 49.8%, acute glomerulonephritis in 34.1%, drug induced intravascular hemolysis in glucose -6-phosphate dehydrogenase deficiency in 4.5%, snake bite in 4%, hemolytic uremic syndrome in 2.2%, and miscellaneous causes in 5.4%. Dialysis was instituted in 178 children and the others were treated conservatively. Renal histology in 39 out of 76 children who presented with an acute nephritic illness revealed acute endocapillary proliferative glomerulonephritis in 27 and crescentic glomerulonephritis in 12. The histology in 79 out of 147 remaining patients showed acute tubular necrosis in 64, acute cortical necrosis in 13, and acute interstitial nephritis in 2. Overall mortality was 27.4%. This high incidence of ARF due to infective diarrhoeas and dysentery reflects poor socio-economic and hygienic conditions, inadequate facilities in rural areas, delays in seeking medical advice, and lack of knowledge about fluid and electrolyte therapy amongst the staff.

Thyrocervical artery - jugular fistula following internal jugular venous catheterization.

Arteriovenous fistula (AVF) is an anomalous communication between an artery and a vein, caused by an iatrogenic or traumatic etiology. Surgically created upper limb AVF remains the preferred vascular access for patients on maintenance hemodialysis. Nonetheless central vein cannulation for hemodialysis is a common procedure done in patients who need hemodialysis. We incidentally detected a thyrocervical artery - jugular fistula in a patient on maintenance hemodialysis. He underwent a successful intra arterial coil embolization of the feeding vessel. Review of literature has shown that, a thyrocervical artery - internal jugular vein arteriovenous fistula following a central venous catheterization has not been reported so far.

Takayasu arteritis in an infant.

Takayasu arteritis (TA), a chronic inflammatory arteritis affecting the aorta and its main branches, is a rare condition mainly affecting young women in the second and third decades of life. Occurrence of TA in infants is extremely rare, with only less than 10 cases reported all over the world until date. We report a case of a 2-year-old girl who presented with hypertension and was diagnosed to have TA with bilateral renal artery stenosis and this is probably the youngest case reported from India.

Plasmablastic myeloma presenting as rapidly progressive renal failure in a young adult.

Multiple myeloma (MM) is a condition where there is malignant proliferation of plasma cells. There is a strong correlation with age, peaking at 60-70 years. The clinical course in adolescents and young individuals is generally indolent and the survival is longer. We report a case of a 28-year-old male, who was diagnosed to have plasmablastic myeloma, an atypical variant of MM with a poor prognosis, presenting as rapidly progressive renal failure. He was given induction chemotherapy and then underwent autologous peripheral blood stem cell transplantation.

Nephrotic syndrome associated with meningioma.

A 58-year-old man presented with recurrent frontal meningioma and nephrotic syndrome. Renal biopsy could not be done in view of the rapid neurological deterioration. The patient underwent surgical resection of the tumor. Within 4 weeks, the edema decreased, serum albumin improved, and proteinuria decreased spontaneously. At three months of followup, the patient had attained complete remission of nephrotic state.

The Churg-Strauss syndrome: An unusual presentation.

The Churg-strauss syndrome (CSS), also referred to as allergic angiitis and granulomatosis is characterized by asthma, peripheral and tissue eosinophilia, extravascular granuloma formation, and vasculitis of multiple organ systems. It is an uncommon disease with an estimated annual incidence of 1-3 per million. Here, we report a case of CSS with glomerulocentric granulomatous reaction with interstitial eosinophils and involvement of retinal vessels.

Acute oxalate nephropathy due to 'Averrhoa bilimbi' fruit juice ingestion.

Irumban puli (Averrhoa bilimbi) is commonly used as a traditional remedy in the state of Kerala. Freshly made concentrated juice has a very high oxalic acid content and consumption carries a high risk of developing acute renal failure (ARF) by deposition of calcium oxalate crystals in renal tubules. Acute oxalate nephropathy (AON) due to secondary oxalosis after consumption of Irumban puli juice is uncommon. AON due to A. bilimbi has not been reported before. We present a series of ten patients from five hospitals in the State of Kerala who developed ARF after intake of I. puli fruit juice. Seven patients needed hemodialysis whereas the other three improved with conservative management.