R K Sharma

Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India

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Publications (101)70.28 Total impact

  • Anita Saxena, R K Sharma
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    ABSTRACT: Post-transplant hypertension is a major risk factor for graft loss and patient survival; therefore, hypertension following renal transplantation must be treated strictly. There seems to be a strong association between hypertension, total body water (TBW) and dry weight. In this study, we report the relationship of body water and body composition with hypertension in post-renal transplant patients. Forty-five post-transplant patients were enrolled in the study. Blood pressure (BP) was labeled as controlled if BP was 120/80 mm Hg and not under good control if BP was above 120/80 mm Hg. Based on the number of antihypertensive medications a patient was taking, patients were divided into two groups: Group 1 patients on one antihypertensive drug and Group 2 patients on more than one antihypertensive drug. Nutritional status of the patients was assessed. Body composition (water compartments, body fat and lean mass) was assessed using bioelectrical impedance analysis (BIA). Patient data were compared with 30 healthy volunteers. In patients, systolic BP was associated with TBW (P = 0.016), extracellular water (ECW Lt; r = 0.99), ECW% (r = 0.78) and diastolic BP with TBW% (P = 0.003), dry weight (r = 0.76) ECW% (r = 0.95) and percent intracellular water (ICW%) (r = 0.79). Compared with controls, ECW and ECW% was higher in patients, and the ICW% was less in patients. There was significant difference in the actual weight of the patients and BIA-derived dry weight, although patients were clinically not edematous. The study showed a significant increase in diastolic BP with increase in dry weight. Significant difference in TBW was observed when the patients were grouped on the basis of the antihypertensive medication a patient was taking (one antihypertensive drug versus more than one antihypertensive drug). This study also showed an association between hypertension and overhydration. BIA may be a useful tool for the clinical assessment of overhydration in non-edematous patients.
    Saudi journal of kidney diseases and transplantation: an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia 01/2014; 25(1):22-8.
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    ABSTRACT: Malnutrition inflammation syndrome (MIS) is common among ESRD patients. In the present study, we have investigated the association of genetic markers associated with appetite and energy regulation with malnutrition inflammation syndrome among end-stage renal disease (ESRD) patients. Two hundred and fifty-seven patients on maintenance hemodialysis and 200 normal healthy controls were included in the study. Nutritional assessment was done by subjective global assessment scores (SGA). Genotyping of leptin-2548 G/A (rs7799039), ghrelin Leu72Met (rs696217-408 C/A), Arg51Gln (rs34911341-346 G/A) and uncoupling protein 2 (UCP2) 45 bp insertion deletion was done using PCR-RFLP. Levels of leptin and acyl ghrelin were assessed using ELISA. Leptin-2548 AA genotype was associated with twofold higher risk of disease susceptibility while UCP2 insertion-deletion heterozygotes showed protective effect. Ghrelin Gln51Gln and Met72Met genotype were associated with 3.4- and 2.5-fold higher disease susceptibility. The Met72 and Gln51 allele showed 3.3- and 2.1-fold higher susceptibility to malnutrition in severe SGA group. Further, the levels of acyl ghrelin were significantly less in severe category of malnutrition and in poor appetite group. On combined analysis, the group 2 (presence of 3-4 risk alleles) showed 1.5- and twofold higher susceptibility to disease and malnutrition, respectively. On docking analysis, it was observed that higher receptor binding energy was associated with the mutant form of ghrelin (Gln51). Moderate and severe SGA were associated with 2.2- and 4.1-fold higher death hazard. Our study suggests that ghrelin may be major marker contributing to susceptibility to MIS among ESRD patients.
    Genes & Nutrition 08/2013; · 3.33 Impact Factor
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    ABSTRACT: During end stage renal disease (ESRD) inflammatory pathways are activated which may lead to malnutrition inflammation syndrome (MIS). In the present study, 257 ESRD patients and 200 controls were included. Cytokine levels and genotyping was done by polymerase chain reaction-restriction fragment length polymorphism and enzyme-linked immunosorbent assay (ELISA). Risk was estimated through binary logistic regression. Cox proportional hazards regression and Kaplan-Meier were used for survival analysis. Tumor necrosis factor TNF-α-308 AA conferred 3.6-fold higher susceptibility (P=0.001) and higher TNF-α levels (P=0.05). TNF-α-238 AA was associated with 3.3-fold higher susceptibility to ESRD (P=0.002). IL-6-174 CC genotype conferred 3-fold risk to disease (P=0.001) along with higher IL-6 levels (P=0.001). IL-10-1082 GG genotype exhibited 2.2-fold higher susceptibility to disease (P=0.013). IL-10-592 AA/-819 TT genotypes were associated with high C reactive protein (P=0.02) and low IL-10 (P=0.03) levels. TNF-α-308 A allele was significantly associated with 2.3-fold higher risk of malnutrition. TNF-α-GAC, AGC and IL-6-CC were risk haplotypes associated with higher disease susceptibility. Combined analysis revealed 1.6-fold higher susceptibility to disease (P=0.02), there was 2-fold higher susceptibility to malnutrition (P=0.02) in high inflammation group. TNF-α-238 AA genotype was associated with 2.5-fold higher death hazard risk (P=0.02). Our study suggests that TNF-α and its genetic variants are major contributors to susceptibility to MIS in ESRD patients.
    Journal of interferon & cytokine research: the official journal of the International Society for Interferon and Cytokine Research 06/2013; · 1.63 Impact Factor
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    ABSTRACT: Renovascular hypertension is the most common cause of secondary hypertension. Imaging plays an important role in establishing the diagnosis in these cases. Digital subtraction angiography (DSA) is the gold standard investigation in suspected cases. Colour Doppler Ultrasound (CDUS) is a very effective and cheap screening tool. CT angiography and MR angiography are effective and comparable alternatives to DSA. Captopril scintigraphy and renal vein renin sampling are used in selected patients in whom the functional significance of the renal artery stenosis is to be determined.
    Clinical Queries: Nephrology. 01/2013; 2(1):29–32.
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    ABSTRACT: CdTe thin films of 500 A ° thickness prepared by a thermal evaporation technique were analyzed for leakage current and conduction mechanisms. Metal–insulator–metal (MIM) capacitors were fabricated using these films as a dielectric. These films have many possible applications, such as passivation for infrared diodes that operate at low temperatures (80 K). Direct-current (DC) current–voltage (I–V) and capacitance–voltage (C–V) measurements were performed on these films. Furthermore, the films were subjected to thermal cycling from 300 K to 80 K and back to 300 K. Typical minimum leakage currents near zero bias at room temperature varied between 0.9 nA and 0.1 lA, while low-temperature leakage currents were in the range of 9.5 pA to 0.5 nA, corresponding to resistivity values on the order of 108 X-cm and 1010 X-cm, respectively. Well-known conduction mechanisms from the literature were utilized for fitting of measured I–V data. Our analysis indicates that the conduction mechanism in general is Ohmic for low fields <5 9 104 V cm�1, while the conduction mechanism for fields>6 9 104 V cm�1 is modified Poole–Frenkel (MPF) and Fowler–Nordheim (FN) tunneling at room temperature. At 80 K, Schottky-type conduction dominates. A significant observation is that the film did not show any appreciable degradation in leakage current characteristics due to the thermal cycling.
    Journal of Electronic Materials 01/2013; · 1.64 Impact Factor
  • R.K. Sharma, Harsh Vardhan
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    ABSTRACT: Renal transplantation has become the modality of choice for patients with end stage renal disease. Though it has led to improvement in survival and quality of life mortality still remains high. Cardiovascular disease is the most common cause of mortality in post-renal transplant patients. Hypertension (HTN) being the major traditional risk factor for atherosclerotic cardiovascular disease develops in up to 60–80% of renal allograft recipients. Risk factor for hypertension includes both patient and donor related factor. The major patient related factor includes the use of corticosteroids, calcineurin inhibitors (CNI) and transplant renal artery stenosis (TRAS). In this review we analyze the risk factors, pathogenesis and management of post-renal hypertension.
    Clinical Queries: Nephrology. 01/2013; 2(3):131–135.
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    ABSTRACT: Financial crunch in the present recession results in the non-availability of the right materials at the right time in large hospitals. However due to insufficient impetus towards systems development, situation remains dismal even when funds are galore. Cost incurred on materials account for approximately one-third of the total recurring expenditures in hospitals. Systems development for effective and efficient materials management is thus tantamount to cost-containment and sustainability. This scientific paper describes an innovative model, Hospital Revolving Fund (HRF), developed at a tertiary care research institute in Asia. The main idea behind inception of HRF was to ensure availability of all supplies in the hospital so that the quality of healthcare delivery was not affected. The model was conceptualized in the background of non-availability of consumables in the hospital leading to patient as well as staff dissatisfaction. Hospital supplies have been divided into two parts, approximately 3250 unit items and 1750 miscellaneous items. This division is based on cost, relative-utility and case-specific utilization. 0.1 Million USD, separated from non-planned budget, was initially used as seed money in 1998. HRF procures supplies from reputed firms on concessional rates (8-25%) and make them available to patients at much lesser rates vis-à-vis market rates, levying minimal maintenance charges. In 2009-10, total annual purchases of 14 Million USD were made. The balance sheet reflected 1.4 Million USD as fixed deposit investment. The minimal maintenance charges levied on the patients along with the interest income were sufficient to pay for all recurring expenses related to HRF. Even after these expenses, HRF boosted of 0.2 Million USD as cash-in-hand in financial year 2009-10. In-depth analysis of 'balance sheet' and 'Income and Expenditure' statement of the fund for last five financial years affirms that HRF is a self-sustainable and viable supply chain mechanism to ensure availability of the right materials at the right time at a reasonable cost. Thus innovations like HRF will prove robust in rendering quality healthcare at an affordable cost.
    Journal of health and human services administration 01/2013; 36(1):3-23.
  • Anita Saxena, R.K. Sharma, Amit Gupta
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    ABSTRACT: Bioelectrical Impedance Analysis (BIA) is a noninvasive and bedside tool for assessment of nutritional status. It is expected that patients who have undergone successful renal transplant will have good nutritional intake and steadily the patient will return to normal health and have good nutritional status. Objective The aim of the study was to evaluate effect of graft function on nutritional status in post renal transplant patients with borderline to good allograft function using BIA. Material and methods For this study, 45 post-renal transplant patients with mean serum creatinine 1.42 ± 0.42 mg% and glomerular filtration rate (GFR) 45.1 ± 14.1 ml/min were subjected to bioimpedance analysis. Several parameters were evaluated. Based on BIA derived GFR, patients were divided into two groups (group 1: borderline graft function GFR < 40 ml/min, X = 27.34 ± 9.1 ml/min and group 2: good graft function GFR ≥ 40 ml/min, X = 51.60 ± 9.16 ml/min). Patient data were compared with 30 healthy individuals. Results There was significant difference between healthy controls and the post transplant patients. Based on GFR, there was significant difference in patient groups in body weight (p = 0.01), serum creatinine (p = 0.005), BMI (p = 0.000), fat free mass (p = 0.003), fat mass (p = 0.003), body cell mass (p = 0.000), dry weight (p = 0.001). Patients with borderline GFR had higher serum creatinine but significantly lower body weight, BMI, FFM, FM, and dry weight, indicating poorer nutritional status as compared to those with good graft function. Based on phase angle, there was significant difference between groups A and B in GFR (p = 0.000), extracellular water (p = 0.015), intracellular water (p = 0.002), plasma fluid (p= 0.016), interstitial fluid (p = 0.016), body cell mass (p = 0.024). SGA scores showed that transplant patients had normal nutritional status, but when compared with healthy individuals, there was significant difference in the fat mass, fat free mass and body cell mass as assessed by BIA. Conclusion Compared to patients with good graft function, patients with borderline GFR showed evidence of early nutritional depletion as picked up by BIA implying nutritional deficiency sets in with reduction in GFR (<40 ml/min) which may not be picked up by subjective global assessment but is objectively detected by BIA.
    Clinical Queries: Nephrology. 01/2013;
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    ABSTRACT: a b s t r a c t A review of high operating temperature (HOT) infrared (IR) photon detector technology vis-a-vis material requirements, device design and state of the art achieved is presented in this article. The HOT photon detector concept offers the promise of operation at temperatures above 120 K to near room temperature. Advantages are reduction in system size, weight, cost and increase in system reliability. A theoretical study of the thermal generation–recombination (g–r) processes such as Auger and defect related Shock-ley Read Hall (SRH) recombination responsible for increasing dark current in HgCdTe detectors is pre-sented. Results of theoretical analysis are used to evaluate performance of long wavelength (LW) and mid wavelength (MW) IR detectors at high operating temperatures.
    Infrared Physics & Technology 01/2013; 61:290-298. · 1.36 Impact Factor
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    ABSTRACT: A novel geometry of a multi-stage depressed collector with four stages has been designed for Ka-band space traveling wave tube. The inner structure of each electrode of the collector has been provided with a single-step corrugation of a positive slope followed by a negative slope. The performed simulation predicts that the proposed collector has 7 % more efficiency, less back streaming of electrons and lower weight as compared to the collector with conventional geometry. Additional features of this collector include inherent secondary electron trapping mechanism and better power handling capabilities. Above properties of the proposed collector makes it suitable for space applications.
    Journal of infrared, millimeter and terahertz waves 11/2012; · 1.12 Impact Factor
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    ABSTRACT: A four-beam electron gun has been designed using OPerating environment for Electromagnetic Research and Analysis (OPERA) 3-D to demonstrate the dependence of beam focusing on the thickness and the radial position of anode aperture in a pole piece with reference to the gun axis. The study is important in the sense that focusing the off-axis electron beamlets are a bit difficult with a common focusing system. The OPERA simulated results have been also compared with computer simulation technique simulated results. An example of four-beam electron gun to deliver a total of 428-mA (107×4) current at 6-kV beam voltage has been considered for carrying out the aforementioned study. The four electron beamlets are generated through four individual cathodes, surrounded by electrically isolated four beam focusing electrode and corresponding four individual anodes and a common focusing system.
    IEEE Transactions on Plasma Science 06/2012; vol. 40, no. 6(6-6):1672-1677. · 0.87 Impact Factor
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    ABSTRACT: �������� ��������� �������� � ��� �� �� � ���� ��� ��� �� �� ��Multi-stage depressed collector plays a major role in determining the overall efficiency of high efficiency space TWTs particularly for space applications. This paper presents the dependency of collector efficiency on the radial dimensions of the multi-stage depressed collector. In addition, an approach to reduce the radial dimensions of the collector without significantly compromising the collector efficiency using external magnetic field in the collector region would also be presented. ����� ������������� � �� �� � ����� � �� � � ���� � � ��������� �� ��������� � �� �� � � � � ���� ���� �� � � ! � � �� "#$%&�'(� � � �� ��! � � �� �� �� � � � ����� � ������ �� )� )�! � �� ���� � *�� ������ � �+� � ���� ��� � ���� �� ��� � � ���,� � ��������� ��� � �� � � � �� ��,� �� ����� ����� ��� ���� ����� � � ����� � ����� �� ��� � ����-� ��+� ��� � )����� ����� � ���� ������ ��! � � �� ����� �� �,� ������������ �� � � ������ �� � ������./0� ��� �� ��� � �� ��� � � 1� ��,.� � �� '2340 � ( � �� ��,� �� � ��� ���� �� � ��� ���� � �� � ������� �)������������ �����-� ���������� �� ������� � �
    IVEC 2012; 04/2012
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    ABSTRACT: Glomerular filtration rate (GFR) prediction equations are widely used in clinical practice for quick assessment of kidney function. Gates method using radionuclide technique is an alternative to prediction equations for quick assessment of GFR. Aim of the study was to compare Gates method and modification of diet in renal disease (MDRD) equation in a sizeable patient population with wide range of renal function to evaluate their clinical utility. GFR was estimated in 897 subjects with wide range of renal function by gates method, and MDRD equation and results were compared against measured GFR. Subjects were divided in to 4 groups (0-30 ml, 31-60 ml, 61-90 ml, >90 ml) on the basis of measured GFR and comparison between two methods done through linear regression analysis. Analysis of R(2) indicated that 56% of the interindividual variability for Gates GFR was in accordance to variation in measured GFR, in the GFR range of (0-30 ml), this value dropped to 39% in the GFR range of 31-60 ml, 40% in the GFR range of 61-90 ml, 26.4% in the GFR range of >90 ml, the corresponding figure for MDRD GFR were 47.9%, 31.1%, 17.6% and 16.1%, respectively. Gates method is more precise for GFR estimation at all levels of renal function.
    Indian Journal of Nephrology 03/2012; 22(2):103-7.
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    ABSTRACT: A four beam electron gun has been designed for multi-beam klystron using commercially available software OPERA 3D and the optimized beam focusing has been again examined through CST particle studio. This paper represents the effect of radial position of aperture in a pole piece in focusing of multi-beam electron gun. The operating voltage of electron gun is 4 kV with total beam current of 256 (64x4) mA and beam perveance of 1.01 micro Perv which is equally divided among all the beamlets.
    Journal of Physics Conference Series 03/2012; 365(365 (2012) 012047).
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    ABSTRACT: Renal impairment in patients with coronary artery disease (CAD) is common and increases morbidity and mortality. Estimation of glomerular filtration rate (GFR) by measuring serum creatinine (Cr) or Cr clearance has limitations. Cystatin C is a novel marker for renal function that is very sensitive and specific for GFR estimation. The utility of plasma cystatin C (PCyC) in patients with CAD needs further study, especially in the developing world, where CAD is rising exponentially. In a prospective study of 150 patients undergoing coronary angiography, median PCyC was 1.45 mg/L; patients with levels ≥1.45 mg/L were older, had higher mean number of diseased coronary vessels, more frequently had triple vessel disease (TVD), and diffuse CAD on angiography. This association of higher PCyC levels with CAD remained robust even after excluding patients with eGFR<60 ml/min/1.73 m(2). The relative risk (RR) of having TVD or diffuse CAD in the overall cohort was 1.7 and 1.9, while it was 1.91 and 2.3 respectively in those with eGFR≥60 ml/min/1.73 m(2), with PCyC levels more than median. Categorization of the entire cohort and those with eGFR≥60, into tertiles based on 33rd and 66th percentiles of PCyC maintained the association of cystatin C with more severe CAD. In Indian patients with CAD, higher PCyC levels are associated with more severe CAD. The association of PCyC with severe CAD remains robust even in patients with normal or mildly impaired renal function. Cystatin C may have potential clinical usefulness as a marker for identification of high risk CAD patients.
    Journal of Cardiology 03/2012; 59(2):182-9. · 2.30 Impact Factor
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    ABSTRACT: Isolated renal zygomycosis is a life-threatening infection and difficult to diagnose ante mortem due to varied presentations. Most reports in the literature are case reports. We are presenting our experience of 10 patients. Retrospective data of 10 consecutive patients with primary renal zygomycosis, including 2 post-transplant patients, in our tertiary care center was analyzed. Epidemiological characteristics, predisposing conditions, clinical presentation, diagnostic findings and treatment outcomes were recorded. Characteristic radiological findings were recorded. Localized disease was managed by supportive treatment or percutaneous drainage and extensive disease with unilateral or bilateral nephrectomy. Renal involvement was confirmed in all patients by histopathology. The mean age of presentation was 35 years. Five patients who had bilateral renal involvement presented with oliguric acute renal failure, hematuria and abdominal pain. Three had unilateral renal disease and presented with flank pain and fever. The two post-transplant patients presented with fever and graft dysfunction. Even after aggressive treatment 5 patients died, accounting for a mortality rate of 50%. Isolated renal zygomycosis can be diagnosed with typical radiological findings, combined with clinical, laboratory and histopathological features. This study describes the newer ante mortem radiological diagnostic criteria and prognostic predictors of the disease.
    Urologia Internationalis 02/2012; 88(3):282-8. · 1.07 Impact Factor
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    ABSTRACT: This paper represents the design of multi-beam (sixty-beam) electron gun and focusing system for high power, compact klystron. The beam voltage is 4 kV with a total beam current of 513 (8.55 × 60) mA which is equally divided among sixty-beam. Each beam has a perveance of 0.033 μP making a total gun perveance of 2.02 μP corresponding to a total beam power of more than 2 kW. The cathode radius is7 mm and individual emitter radius is 0.2 mm having current density 6.7 A/cm2. The design has been accomplished using OPERA 3D code. All beamlets have individual anode as well as BFE and a common focusing system. Potential difference between cathode and anode is 4 kV. A magnetic field of 1200 Gauss is applied along the beam axis. A major challenge for the development of multi-beam klystron is design and technology for the focusing of off-axis beamlets because off-axis beams are at various azimuths.
    Proceedings of International Symposium on Vacuum Science & Technology and its application for accelerators,(IVS-2012); 02/2012
  • Indian Journal of Transplantation. 01/2012; 6(2):61–63.
  • Sudeendra S. Gupta, R.K. Sharma
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    ABSTRACT: Diabetes is a significant contributor for end-stage renal disease (ESRD). Apart from hemodialysis and peritoneal dialysis various forms of transplantation like renal transplantation, simultaneous pancreas kidney (SPK) transplantation and pancreas after kidney transplantation (PAK) are offered in eligible diabetic ESRD patients. Cardiovascular status determines survival outcomes predominantly. Any corrective cardiovascular intervention should be undertaken prior to transplantation. Survival outcomes are the best with transplantation in eligible diabetic ESRD patients when compared to their waitlisted counterparts. Microvascular and to some extent macrovascular complications are benefited by successful SPK or PAK although though benefited is appreciable after 5 years post transplantation.
    Clinical Queries: Nephrology. 01/2012; 1(2):159–162.
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    ABSTRACT: In this paper we present a method of analyzing the performance non-uniformity of HgCdTe photodiode arrays for infrared imaging applications. For quantifying the characteristic behavior of various photodiodes, we have parametrized the dynamic resistance verses voltage signatures in such a way that the obtained signature parameters have some relevance with different physical parameters. We also estimated the sensitivity of the proposed signatures on physical parameters using statistical technique.These characteristics signatures may be used to quantify the non-uniformity of the HgCdTe photodiodes in IR imaging arrays and its analysis. The method presented here is based on theoretical calculation of MWIR HgCdTe photodiodes. However, the method is generic and may be implemented on any other type of diode arrays for theoretical or experimental analysis of their non-uniformity.
    Infrared Physics & Technology 01/2012; · 1.36 Impact Factor