A Comparative study of Glomerular Filtration Rate Calculation by Cockcroft-Gault, MDRD, CKD-EPI Formula and DTPA Renal Scan among live related Kidney Donors

INTRODUCTION: CKD progresses into end stage renal disease (ESRD) inspite of our strategies to slow the progression of the disease. ESRD occurs when kidney function is not able to cope up with the body’s excretory load and hemodialysis, peritoneal dialysis, or kidney transplantation has to be substituted for native kidney function. Among them, kidney transplantation by far imparts a better quality of life in ESRD patients. The shortage of donor organs is a global issue, that restrict kidney transplantation. Hence patients and transplant surgeons are increasingly dependent on live kidney donors. Although kidney transplantation offers a favourable outcome for the recipient, it may be associated with some risk for the donor. To minimize the risks a strict pre-operative donor evaluation is essential. Renal function assessment of the donor is the most important part of donor evaluation. Glomerular filtration rate (GFR) is considered to be optimal test for overall assessment of renal function but serum creatinine is not considered as appropriate and only measurement of renal function, especially for detection of early stages of CKD due to its tubular secretion and also its variability with body mass , age, sex and race. It is well known that GFR can be precisely measured by specific filtration markers such as Inulin, I125 Iothalamate, Cr 51 EDTA,Tc99-diethylene triamino penta acetic acid (DTPA). These standard methods cannot be used in daily clinical practice unfortunately as they are expensive, time consuming and cumbersome and require specialized equipments and skills. So a non invasive and accurate estimation of GFR is the need of the hour in Nephrology. Here comes the GFR prediction equations which are easy to apply, cost effective and less cumbersome. The new K/DOQI Guidelines also recommend estimating GFR by MDRD and COCKCROFT-GAULT equations. Hence, it sounds worthy for me to take up this comparative study of GFR calculation by COCKCROFT-GAULT formula, MDRD formula, CKD-EPI formula and DTPA renal scan among live related kidney donors. AIMS AND OBJECTIVES: 1. To estimate GFR by 3 different methods namely COCKCROFT-GAULT formula, MDRD formula and CKD-EPI formula, among live related kidney donors. 2. To analyse how closely the GFR calculated by these formulae correlate with that of DTPA renal scan in them. MATERIALS AND METHODS: Study Design: observational study. Study Place: Department of Nephrology, Government Stanley Hospital Chennai. Study Period: 6 months from April 2011 to September 2011. Study Population: Individuals attending Nephrology OPD for undergoing evaluation for kidney transplantation. Samle Size : 50 individuals. Sampling : Simple random sampling. Inclusion Criteria: Normal individuals who are willing for kidney donation and undergoing evaluation for the same. Exclusion Criteria: 1. Age 55 years, 2. ABO incompatibility, 3. Donors with h/o HT, DM, 4. Donors with newly detected HT, DM, 5. Females with h/o gestational diabetes and gestational hypertension, 6. Donors with family h/o renal disease. RESULTS: This study included 50 individuals who underwent renal donor workup at the Department of Nephrology, Government Stanley Hospital. Their GFR was calculated by 3 different methods namely COCKCROFT-GAULT formula, MDRD formula and CKI-EPI formula and they were compared with the DTPA renal scan reports. SUMMARY AND CONCLUSIONS: The prediction equations namely Cockcroft-Gault, MDRD and CKD-EPI were found to correlate with the DTPA scan values. • However they underestimated GFR by 27.65%, 27.17% and 22.42% respectively, the possible reasons could be - lack of standardization in calibration of serum creatinine. - study population predominantly being females. - sample size was small. - African–Americans were not included in the study. - MDRD and Cockcroft-Gault were devised in the CKD setting and not in the normal population, our study group belonged to normal and healthy adults. • These prediction equations were not validated in our population and our clinical set up. • DTPA scan gives split GFR of each kidney, renal tubular function, details about renal blood supply, renal tubular obstruction or damage. • DTPA scan cannot be substituted by the prediction equations in special situations like renal transplantation. • However extensive research work are under process, which may bring out newer, more accurate, less invasive and cheaper ways of estimating GFR which can be applicable in all the clinical settings. • Let us hope we achieve that in the near future

Microbial Biotransformation for the Production of Steroid Medicament

Androstenedione (AD) is a steroid intermediate valuable for the production of steroid medicaments. Microbial biotransformation of phytosterol to produce AD is a well-researched area. However, low substrate solubility of phytosterol in aqueous media and nucleus degradation of AD to androstadienedione (ADD) or 9-hydroxy-AD are the major obstacles for AD production leading to detailed research for optimization of biotransformation process. In this review, microbial transformation of AD with respect to the existing methods of chemical or biochemical synthesis of AD are extensively discussed. This review examines the microbial biotransformation process and limitations for enhanced AD production. Factors affecting the effective biotransformation process to obtain AD are discussed and limitations are highlighted. The main content of this review focuses on the recent and futuristic biotechnological advances and strategies in techniques to enhance AD bioprocess

A Study of the Contact of an Elastic Layer-Substrate System Indented by a Long Rigid Cylinder Incorporating Surface Effects

Contact problem of a layer-substrate system comprising of an elastic layer and an elastic substrate perfectly bonded to each other with surface effects based on Gurtin-Murdoch (GM) model indented by a long rigid cylinder is solved. The requisite Green's function relating surface displacement to surface load is obtained semi-analytically through the combination of the Airy stress function and Fourier transforms under the plane-strain condition. The contact solution is analyzed to study the influence of layer thickness, modulus mismatch between the layer and substrate, and surface parameters on contact size and contact pressure during indentation of a layer-substrate system. A map is presented which indicates whether during indentation by a rigid cylinder, a layer-substrate system is required or a homogeneous system based on layer properties is enough for a given shear modulus mismatch ratio and layer thickness. The map and the related analysis clearly indicate that whenever the contact size or layer thickness approaches intrinsic length scale based on the ratio of surface parameter and bulk elastic properties, surface effects should be considered

In Vitro Biotransformation in Drug Discovery

In vitro Biotransformation studies play a crucial role in drug discovery program that determine the fate of the new chemical entities (NCE’s). Enzyme rich matrices such as microsomes, hepatocytes, liver fractions and S9 fractions transform the new chemical entities to different metabolites. Metabolites could be pharmacologically important or toxic. Newly formed metabolites are identified using liquid chromatography interfaced with mass spectrometry. Identification of the biotransformation sites in the new chemical entity helps the medicinal chemists to optimize its structure and develop the NCE as a pharmaceutical drug. Screening pharmaceutical drugs using in vitro biotransformation studies assist in selecting the right new chemical entity for further in vivo studies in animal systems and later in human clinical trials

Impact of Magnetic Field on Convective Flow of a Micropolar Fluid with two Parallel Heat Source

A numerical study is performed to analysis the buoyancy convection induced by the parallel heated baffles in an inclined square cavity. The two side walls of the cavity are maintained at a constant temperature. A uniformly thin heated plate is placed at the centre of the cavity. The horizontal top and bottom walls are adiabatic. Numerical solutions of governing equations are obtained using the finite volume method coupled with the upwind and central difference technique. Numerical results of the two-dimensional flow field governed by the Navier-Stokes equations are obtained over a wide range of physical parameters, namely the Rayleigh number, the Hartmann number, the inclined angle of the magnetic parameter and the vortex viscosity parameter. It is observed from the results, the heat transfer rate is reduced when increasing Hartmann number, inclination angle and vortex viscosity parameter. The higher heat transfer rate is obtained based on the Newtonian fluid compared to the micropolar fluid

The liquidity impact on bond calculation on credit losses : a Malaysian banks’ perspective

Purpose: The aim of this paper is to empirically determine the stance of the Nigerian financial sector in absorbing or intensifying trade shocks. Design/Methodology/Approach: Towards achieving this objective, the study uses Auto-Regressive Distributed Lag (ARDL) technique to analyse annual data from 1981 to 2017. Data used in this study were sourced from Central Bank of Nigeria Statistical Bulletin and Statista. Findings: Major finding from the long-run result shows that financial development intensifies trade-led shocks, there by yielding to output volatility. Practical implication: Based on findings, the study recommends the Nigerian government to focus on the achievement of greater and more inclusive financial development. This can be achieved through; increasing the availability and affordability of financial services, easing access to loans, improving soundness of banks and fostering legal traditions that protect creditors and investors. Originality/Value: In addition to the lack of available literature with focus on this subject in the Nigerian sphere, understanding the role of Nigerian financial sector in absorbing trade-led shocks is fundamental in optimizing Nigeria’s benefits from trade. This is of utmost importance, particularly in a time where the nation just signed the Africa Continental Free Trade Agreement.peer-reviewe

Effects of metal implants and validation of four treatment planning methods used for radiotherapy dose calculation

Background: The radiotherapy treatment planning process involves target delineation and dose calculation, both of which directly depend on image quality and Hounsfield unit (HU) accuracy of computed tomography (CT) images. CT images of patients having metal implants undergo image quality deterioration and show inaccurate HU values due to various artifacts. Metal artifact reduction (MAR) is used to improve the image quality. In this study, four treatment planning methods with and without MAR, in combination with actual and assigned HU values, were analyzed for dose calculation accuracy. The aim was to study the effects of metal implants on planning CT and to evaluate the dose calculation accuracy of four treatment planning methods for radiotherapy. Materials and methods: Two phantoms with six different metal inserts were scanned in the extended HU mode, with and without MAR. Geometry verification and HU analysis of the metals and the surrounding region were carried out. Water equivalent distance (WED) measurements and dose calculation for each metal insert were done in the treatment planning system (TPS) using the anisotropic analytical algorithm (AAA). Point dose and two-dimensional dose distribution were studied. Percentage variation analysis between calculated and measured doses and gamma evaluation were conducted to determine the most suitable method for treatment planning. Conclusion: This study concludes that an MARCT image with an assigned HU similar to that of the metal implant is better for contouring and high dose calculation accuracy. If MAR is not available, the actual HU value from the extended HU CT for the metal should be used for dose calculation