Showing papers by "University of Peradeniya published in 2003"

Dynamic modeling of doubly fed induction generator wind turbines

Abstract: It is now recognized that many large wind farms will employ doubly fed induction generator (DFIG) variable speed wind turbines. A number of such wind farms are already in operation and more are planned or under construction. With the rising penetration of wind power into electricity networks, increasingly comprehensive studies are required to identify the interaction between the wind farm(s) and the power system. These require accurate models of doubly fed induction generator wind turbines and their associated control and protection circuits. A dynamic model has been derived, which can be used to simulate the DFIG wind turbine using a single-cage and double-cage representation of the generator rotor, as well as a representation of its control and protection circuits. The model is suitable for use in transient stability programs that can be used to investigate large power systems. The behavior of a wind farm and the network under various system disturbances was studied using this dynamic model. The influence of the DFIG control on the stability of the wind farm was also investigated by considering different control gains and by applying network voltage control through both stator side and rotor side converters.

Chronic Hyperplastic Candidosis/Candidiasis (Candidal Leukoplakia)

Abstract: Chronic hyperplastic candidosis/candidiasis (CHC; syn. candidal leukoplakia) is a variant of oral candidosis that typically presents as a white patch on the commissures of the oral mucosa. The major etiologic agent of the disease is the oral fungal pathogen Candida predominantly belonging to Candida albicans, although other systemic co-factors, such as vitamin deficiency and generalized immune suppression, may play a contributory role. Clinically, the lesions are symptomless and regress after appropriate antifungal therapy and correction of underlying nutritional or other deficiencies. If the lesions are untreated, a minor proportion may demonstrate dysplasia and develop into carcinomas. This review outlines the demographic features, etiopathogenesis, immunological features, histopathology, and the role of Candida in the disease process. In the final part of the review, newer molecular biological aspects of the disease are considered together with the management protocols that are currently available, and directions for future research.

Preparation and characterization of vanadyl complexes with bidentate maltol-type ligands; in vivo comparisons of anti-diabetic therapeutic potential.

Abstract: A series of 2-alkyl-3-hydroxy-4-pyrone oxovanadium(IV) compounds has been synthesized, characterized, and tested for bioactivity as potential insulin-enhancing agents. The vanadyl complexes, bis(maltolato)oxovanadium(IV), BMOV, bis(ethylmaltolato)oxovanadium(IV), BEOV, and bis(isopropylmaltolato)oxovanadium(IV), BIOV, were compared against vanadyl sulfate for glucose-lowering ability, when administered i.p. to STZ-diabetic rats, at a one-time dose of 0.1 mmol kg–1 body weight. Blood levels of vanadium were determined at regular intervals, to 72 h, following i.p. injection. All complexes tested exceeded vanadyl sulfate in glucose-lowering ability; this effect was not correlated, however, with blood vanadium levels. Analysis of the pharmacokinetics of the disappearance of [ethyl-1-14C]BEOV after an oral gavage dose (50 mg kg–1, 0.144 mmol kg–1, in a 10 mL kg–1 volume of 1% CMC solution) indicated clearly that metal ion-ligand dissociation took place relatively soon after oral ingestion of the complex. Half-lives of fast phase uptake and slow phase disappearance for 14C and V were calculated from a two-compartment model for whole blood, plasma, liver, kidney, bone, small intestine, and lung, ranging from 17 min (t 1/2α for 14C, liver) to 30 days (t 1/2β for V, bone). Curves of disappearance of plasma and whole blood 14C and V diverged dramatically within the first hour after administration of the vanadium complex.

Control of DFIG wind turbines

Abstract: The generation of electrical power using sustainable sources of energy is developing rapidly. The authors describe how the security and quality of electricity supply might be maintained. They discuss the control of variable speed using doubly fed induction generators (DFIG) in wind turbines. The DFIG is constructed from a wound rotor asynchronous machine. Variable speed operation is obtained by injecting a variable voltage into the rotor at slip frequency The injected rotor voltage is obtained using two AC/DC insulated gate bipolar transistor based voltage source converters (VSC), linked by a DC bus. The converter ratings determine the variable speed range. Speed control for optimum power, system frequency control, and machine inertia are also discussed.

Application study of a STATCOM with energy storage

Abstract: With advances in energy storage technology the application of STATCOMs with energy storage for utility applications, such as active- and reactive-power compensation of loads, network-voltage control and mitigation of power system disturbances, is increasingly feasible. As it is more expensive to produce active power than reactive power, it is important to consider methods which can be adopted to minimise the use of the energy store. An application study of a STATCOM with energy storage giving special emphasis to control strategies which minimise the use of the stored energy is reported. Calculation techniques to determine the current rating of the IGBTs, diodes and connecting transformer as well as the losses associated with the switches when the compensator is operated under space-vector modulation are demonstrated. Application studies of the compensator with energy storage for load compensation, steady-state voltage control, mitigation of voltage sags and elimination of power oscillations are described. The analytical studies of each of these applications are supplemented by simulation results carried out in PSCAD/EMTDC and by experimental results obtained from a laboratory prototype.

Epidemiology and clinical picture of the Russell's viper (Daboia russelii russelii) bite in Anuradhapura, Sri Lanka: a prospective study of 336 patients.

Abstract: Russell's viper (russelii russelii) bite is associated with a high incidence of mor- bidity and mortality in Sri Lanka. Hence, this study enrolled all consecutive Russell's viper bite admissions to the 'Unit A' of General Hospital, Anuradhapura, over a two year period from January 1996, to describe the epidemiology, clinical picture, treatment and outcome. There were 336 cases which showed the following results. The male: female ratio was 5:1; 75% of patients were below the age of 40 years. Biting occurred mainly in paddy fields 41%, and on footpaths 29% at dusk or dawn. Envenoming manifested in 310 (92%) of patients as follows: local swelling 92%, local necrosis 8.9%, coagulopathy 77%, neurotoxicity 78%, nephrotoxicity 18%, cardiac effects 3-12% and myotoxicity 14%. Coagulopathy appeared within 30 minutes to 12 hours after the bite and was corrected within 1 hour to 48 hours (mode 20 hours). Neurotoxicity recovered spontaneously in 1 to 5 days (mode 3 days); however, eight patients needed mechanical ventilation. Thirteen (4%) of patients were man- aged with peritoneal dialysis because of hyperkalemia caused by a hypercatabolic state (7) and acute renal failure (6). The mortality rate of the series was 2.6% (9 patients). Rural dry zone paddy farmers are the common victims of Russell's viper bite in Sri Lanka and its' envenoming leads to diverse clinical manifestations. Therefore, practically feasible preventive measures should be developed to minimize the incidence of bite and an evidence based management guideline should be developed for hospital practice.

Emerging rickettsial infections in Sri Lanka: the pattern in the hilly Central Province

Abstract: OBJECTIVES To identify different rickettsial infections using a specific immunofluorescent technique in patients clinically diagnosed as 'typhus fever' in the Central Province of Sri Lanka, and to define the clinical picture, assess the severity of infection and to determine the pattern of geographical distribution of the infections of the hospital-based patients. METHODS A specific indirect immunofluorescent antibody technique was used on the sera of two groups of patients in laboratories in Japan and Thailand. RESULTS We serodiagnosed infections with Orientia tsutsugamushi, Rickettsia typhi and spotted fever group in 56 of 118 clinically investigated patients. There were eight infections with O. tsutsugamushi, two with R. typhi and 10 spotted fever group patients with IgM antibodies suggestive of acute infection. Nineteen patients had antibodies against these three rickettsial species, suggestive of past exposure, co-infection or cross-reactivity of antigens. Discrete, erythematous maculopapular rash was common to all three types of infection except for five patients who had no rash. Five patients positive for spotted fever antibodies developed fern-leaf type skin necrosis with severe illness. Duration of the febrile period ranged from 4 to 23 days with defervescence occurring after specific antibiotic treatment. CONCLUSIONS The study has shown the presence of different types of rickettsial infections in the Central Province of Sri Lanka. The characterization of the clinical picture and the severity of infection provide useful information for the proper management of the patients in the future.

Validation of a Sinhalese translation of the Oral Health Impact Profile-14 for use with older adults.

Abstract: Objective: To test the psychometric properties of a Sinhalese translation of the OHIP-14 scale for use among older adults in Sri Lanka. Design: A cross-sectional survey. The English version of the OHIP-14 was translated in to Sinhalese, pre-tested and subsequently administered to the subjects by a trained interviewer. Setting: Moratuwa — a densely populated urban area in the Western province of Sri Lanka. Subjects: 585 individuals aged 60 years and above. Main outcome measures: Reliability of the translated scale was assessed in terms of internal consistency using Cronbach's alpha. Construct validity was evaluated by examining the associations between perceived oral health status, perceived need for dental care and the OHIP scores. Results: Cronbach's alpha of the translated scale was 0.93. Corrected item-total correlation coefficients ranged from 0.53–0.80. The highly significant associations between perceived oral health status, perceived need for dental care and the OHIP scores support the construct validity of the translated scale. Conclusion: The Sinhalese translation of the OHIP-14 is a valid and reliable instrument to measure oral health related quality of life in older adults of Sri Lanka.

Protection against diethylnitrosoamine-induced hepatocarcinogenesis by an indigenous medicine comprised of Nigella sativa, Hemidesmus indicus and Smilax glabra: a preliminary study

Abstract: A decoction comprised of Nigella sativa seeds, Hemidesmus indicus root and Smilax glabra rhizome is used to treat cancer patients in Sri Lanka. However, the anti-carcinogenic properties of this decoction have not been experimentally confirmed. The purpose of this study was to determine whether the above decoction could protect against chemically induce hepatocarcinogenesis.

Resolving conflicts in water sharing: A systemic approach

Abstract: [1] With industrial development and economic growth, conflicts over use and allocation of water have been increasing. Though diverse efforts have been made toward resolving conflicts through computer-based models, its clear understanding is prerequisite for models to be effective. A systems view illuminates how people think and consequences of their thoughts and actions on results and thus helps to achieve sustainable solutions. This paper presents a systemic approach to assist stakeholders in two different jurisdictions in a hypothetical water resource system to resolve a potential water-sharing conflict. A causal loop diagram developed provides an understanding of the conflict dynamics and feedback nature. A system dynamics simulation model developed fitting the causal diagram offers a significant opportunity to explore conflict's behavior and resolution with respect to final water allocations and time necessary to reach an agreement. The impact of initial aspiration, influence on system and struggle of stakeholders is discussed in detail.

Stability analysis based on instantaneous driving behavior using car following data

Abstract: This paper attempts to analyze the stability of a platoon using experimental data measured by RTK GPS receivers. Car following experiments were conducted in a test track using ten passenger cars and tested various speed patterns for lead car, including random constant and sinusoidal speed patterns, giving different driving conditions. The response of following drivers was measured by RTK GPS receivers equipped in each car. The stimulus-response based car following concept was examined assuming that the reaction time might vary over time. A graphical method was modified to estimate time variant reaction time more efficiently. A new algorithm was proposed to estimate sensitivity factor using Glissandos diagram between relative speed and acceleration. The statistical analysis showed that intrapersonal variability was higher than interpersonal variability for both reaction time and sensitivity factor. However, the influence of driver position in the platoon and speed patterns was low. It was found that the reaction time was distributed in lognormal function for most of the drivers. The variations in the estimated values for the sensitivity factor were relatively high. The stability analysis showed that the average response of drivers was unstable both locally and asymptotically. The influence of speed fluctuations on the stability of the platoon was found insignificant

Stability Analysis Based on Instantaneous Driving Behavior Using Car-Following Data

Abstract: An attempt is made to analyze the stability of a platoon using experimental data measured by real-time kinematic (RTK) Global Positioning System (GPS) receivers. Car-following experiments were conducted on a test track using 10 passenger cars. Various speed patterns were tested for the lead car, including random, constant, and sinusoidal, giving different driving conditions. The responses of the following drivers were measured by RTK GPS receivers in each car. The stimulus-response car-following concept was examined, assuming that the reaction time might vary over time. A graphical method was modified to estimate the time-variant reaction time more efficiently. A new algorithm was proposed to estimate the sensitivity factor using Lissajou's diagram between relative speed and acceleration. The statistical analysis showed that intrapersonal variability was higher than interpersonal variability for both reaction time and sensitivity factor. However, the influence of the driver's position in the platoon and speed patterns was low. It was found that the reaction time was distributed in a lognormal function for most of the drivers. The variations in the estimated values for the sensitivity factor were relatively high. The stability analysis showed that the average responses of drivers were unstable both locally and asymptotically. The influence of speed fluctuation frequency was found insignificant for the stability of the platoon.

Association between smoking, betel chewing and gingival bleeding in rural Sri Lanka.

Abstract: Objective: To ascertain the association between tobacco use and gingival bleeding in a rural community in Sri Lanka. Material and methods: A cross-sectional field-based study was carried out in 2178 rural males aged 20–60 years, employing a multistage cluster sampling technique. The levels of plaque and gingivitis were recorded on four sites of all teeth present excluding third molars, using the plaque index (PLI) and gingival index (GI). Information pertaining to sociodemographic variables, oral hygiene practices and tobacco consumption habits was obtained from all subjects. Results: One-way anova combined with the Bonferroni test disclosed that betel chewers had a significantly higher mean number of sites with gingival bleeding (22.6±21.8) than smokers (10.8±11.2) and nontobacco users (8.7±6.8) (p<0.0001). A higher proportion of betel chewers (55.1%) showed ≥12 bleeding sites compared to smokers (27.6%). Logistic regression analysis revealed that the association between betel chewing and gingival bleeding was positive (OR=2.41; p<0.0001) whereas that of smoking and gingival bleeding was negative (OR=0.75; p<0.05). Oral hygiene had the strongest relationship with gingival bleeding (OR=18.11). Conclusion: While confirming the masking effect of smoking on gingival bleeding, these findings indicate that betel chewing might significantly enhance gingival bleeding in the population studied.

Dental anxiety in patients seeking care at the University Dental Hospital in Sri Lanka.

Abstract: Objective The purpose of the study was to determine the prevalence and factors affecting dental anxiety in patients seeking dental care. Design A cross sectional study. Participants 503 first visit patients attending the University Dental Hospital in Peradeniya, Sri Lanka. Outcome measures Corah's dental anxiety scale was used to assess the dental anxiety in these patients. Results The prevalence of dental anxiety was 32% (DAS score > or = 12) while 12% were considered to be extremely anxious (DAS score > or = 15). Females were found to be more dentally anxious than males. Level of education was associated with dental anxiety. Problem oriented attenders had a significantly higher mean DAS score than regular attenders. Those who had an extraction at the last dental visit were significantly more dentally anxious than those who had a restoration/scaling. Negative dental experience was not associated with dental anxiety. The logistic regression model revealed that gender, level of education and 'fear' which was cited as the reason for the delay in seeking care for the presenting complaint were significant predictors of dental anxiety. However, only 4% of the variation in dental anxiety could be explained by these independent variables. Conclusion Socio-demographic factors and variables related to past dental experiences had a limited influence in explaining dental anxiety in this sample of dental patients.

Geochemical and petrological characteristics of Eppawala phosphate deposits, Sri Lanka

Abstract: The apatite-bearing carbonate rocks at Eppawala, Sri Lanka occur as massive, discontinuous bodies in a Precambrian, high-grade metamorphic terrain, which weather to form economically important phosphate deposits The ore bodies at Eppawala contain ≤42% P2O5, and citric acid solubility of different components varies from 4 to 6% The parent rocks are mainly made up of calcite, dolomite and apatite, with lesser amounts of ilmenite, magnetite, pyrite, forsterite, phlogopite, enstatite, magnesite, diopside, tremolite and spinel Most of minerals show an euhedral habit, with a wide range of crystal sizes (from a few millimetres to several decimetres) The Eppawala rocks are characterised by low silica (≤041%), high phosphorous (≤1058%) and high strontium content (2,960–6,819 ppm) Concentrations of light rare-earth elements in these rocks are comparably higher than those of marbles The REE fractionation of these rocks is pronounced, and La/Yb ratios vary between 14 and 43 Both apatite and calcite show markedly elevated strontium levels (≤06%) The δ 13CPDB and δ 18OSMOW values of the carbonates are in the range of –34 to –22 and 77 to 164‰ respectively The euhedral habit, as well as the presence of major quantities of apatite and considerable amounts of iron-bearing minerals suggest that the ore host rock has genetic links to an igneous source rather than to an intensely metamorphosed limestone The higher light REE contents of the rocks, compared to marbles, also argue against a metamorphic or sedimentary origin The Sr/Mn and Ce/La ratios in the apatite are ~40 and ~2 respectively, suggesting that they were formed in a carbonatite magma The markedly increased REE concentrations in the bulk chemistry of the rocks have been shown to be mainly controlled by the content of phosphate minerals Compared to most carbonatites, the Eppawala rocks are generally depleted in selected trace elements, particularly Ba, Nb, Th, V, U and Zr This depletion may be due to either a primary infertility of the parent magma with regard to such trace elements, or it is a result of fractional crystallisation during the rock formation The stable isotope ratios do not plot within the defined "mantle carbonatite box", but still lie within the broader range of carbonatitic rocks With these data at hand, it can be readily argued that the mode of occurrence, petrography and geochemistry of the Eppawala apatite-bearing carbonates provide conclusive evidence of their carbonatitic origin

Efficacy of probiotics and their effects on performance, carcase characteristics, intestinal microflora and Salmonella incidence in broilers

Abstract: measurement may over-estimate phytase FCReff improvement. The latter varies with cereal type and ration content and improves using anticoccidial, but not with type of fat or oil supplement or phytase product. These observations suggest the need (i) to re-evaluate P, Ca, energy, crude protein, lysine, methionine plus cystine, etc. nutrient-sparing claims for phytase, when based on linear deficiency-dose models (BASF, 2000) and (ii) to apply phytase posology to specified target levels of broiler performance and to specific feed formulations. Further studies, in progress, are now required to (a) revaluate phytase pronutrient equivalencies for feed conversion ratio effects, using curvilinear dosage functions; and (b) investigate potential phytase interactions with (i) individual animal, plant and mineral phosphorus sources and (ii) other side-active and/or admixed exogenous enzymes.

Tumor necrosis factor alpha in the bovine oviduct during the estrous cycle: messenger RNA expression and effect on secretion of prostaglandins, endothelin-1, and angiotensin II.

Abstract: Tumor necrosis factor (TNF) α is an important physiological mediator of cell-to-cell communication. Recent observations suggest that TNFα is involved in the control of reproductive functions. The present study examined the role of TNFα in the secretion of factors involved in regulating smooth muscle contraction, such as prostaglandin E2 (PGE2), prostaglandin F2α (PGF2α), endothelin-1 (ET-1), and angiotensin II (Ang II), as it was in the original by the cow oviduct at different stages of the estrous cycle using an in vitro microdialysis system. Expression of mRNA for TNFα and its receptors (TNFα-R) was also evaluated. For microdialysis, the lumen of a portion (length, 10 cm) of the each oviductal segment was implanted with a dialysis capillary membrane, and TNFα (100 ng/ml) was infused for 4–8 h during a 16-h incubation period. The microdialysis system maintains cell-to-cell integrity and cell-to-cell communication, and it enables real-time observation of physiological changes in the luminal relea...

Comparison of cell proliferation in the centre and advancing fronts of oral squamous cell carcinomas using Ki-67 index.

Abstract: The cell proliferation status of 60 oral squamous cell carcinomas from Sri Lankan subjects was examined by immunohistochemistry using the Ki-67 index. A comparison was made between the indices derived from the centre of the tumours and those derived from the invasive fronts of the same tumours. There was a positive correlation between the two indices suggesting a clonal expansion of malignant cells, but the mean index derived for the invasive fronts (29.75 11.64) was significantly higher than the mean index for the body of these tumours (25.65 11.64). Thus, at a given time, more peripheral cells at the invasive front are proliferating and this compartment is likely to be more informative in prognostic and other behavioural studies involving the cell cycle. In squamous carcinomas, increased and uncontrolled cell proliferation at the invasive front may be one feature contributory to the invasion.

Changing Role of Non-Timber Forest Products (NTFP) in Rural Household Economy: The Case of Sinharaja World Heritage Site in Sri Lanka

Abstract: This paper examines the modified patterns of utilizing non-timber forest products (NTFP) and associated behavioral changes around tropical forest areas in the context of conservation-related objectives and other commercially driven objectives. Our study introduces a conceptual framework based on the household production theory and tests empirically the hypotheses drawn at Sinharaja World Heritage in Sri Lanka. The results show that conditions introduced by forest conservation programs and the spread of small-scale commercial tea cultivation are transforming the economy around Sinharaja. The process is an economically rational one where resident communities decide upon their actions based on the opportunity cost of time involved with NTFP in the absence of observable prices. Although the process, overall, has led to a decline in the role of NTFP in the household economy, its impact over different NTFP are not uniform, leaving sustained demand for certain NTFP. This situation calls for a multifaceted approach in forest management programs to address the various household needs fulfilled by NTFP-based activities.

Early diagnosis of typhoid fever by the detection of salivary IgA

Abstract: Background/Aims: Current diagnostic methods for typhoid fever have low sensitivity and specificity. This study aimed to develop an enzyme linked immunosorbent assay (ELISA) with greater sensitivity and specificity. Methods: The ELISA was developed and evaluated on patients with acute typhoid infection, febrile controls, and healthy controls. A sequential study on patients with culture confirmed typhoid was also carried out to determine the time period of maximum sensitivity. Results: The ELISA detected anti-Salmonella typhi lipopolysaccharide (LPS) salivary IgA antibodies. A six month follow up study of patients with culture confirmed typhoid fever showed that the test shows maximum efficiency during the second and third weeks of fever and enables detection of the acute infection during the early phase. Conclusions: This ELISA can detect typhoid fever during the early phase of infection and is most efficient during the second and third weeks of fever, the time at which patients normally present for treatment. Because the sensitivity of the assay is subsequently greatly reduced, it will be useful for the diagnosis of acute infection.

Intra-oral Dirofilaria repens infection: report of seven cases.

Abstract: Cutaneous dirofilariasis usually affects animals such as cats and dogs which are known to be the natural host of Dirofilaria. Dirofilariasis displays a worldwide distribution. Certain geographic regions account for the majority of reported cases. South-eastern United States, Australia and Europe have been identified as endemic regions (1, 2). However, new endemic areas are arising with increased awareness in African and Asian regions. Out of about 40 different species of Dirofilaria only a few species are commonly known to infect man, namely Dirofilaria immitus, D. tenices and D. repens. Human infection occurs when a human becomes a blood meal of an infected arthropod vector and on accidental entering of the worm. Rarely this zoonotic infection affects the oral mucosa (3). Man is the dead end of this parasite. Since the human body is an abnormal environment for the parasite, the development of the larvae is inhibited by means of retardation of sexual maturity. Lesions are presented as single non-tender subcutaneous nodules, and most patients are asymptomatic. Diagnosis is established by H&E sections prepared from excised nodules. In a majority of the cases, only a single worm either a male or a female could be identified. The worm is usually dead and degenerated with a massive inflammatory cell infiltration. Seven new cases presented as intra-oral nodules with their clinicopathological correlation are discussed.

Sources of Competitive Advantage and Firm Performance: The Case of Sri Lankan Value-Added Tea Producers

Abstract: Given the greater importance of firm-effects as opposed to industry-effects in explaining firm performance, this study incorporated the resource and strategy-based views of the competitive advantage paradigm in explaining the performance of value-added tea producers in Sri Lanka. The study revealed the existence of three significantly different strategic groups and justified the assertion that there is significant intra-industry heterogeneity. Only one strategic group, which comprised four dominant firms, revealed strong mobility barriers and higher performance differences. However, no performance differences were evident between the other two strategic groups.

Vesicoureteric reflux and reflux nephropathy.

Abstract: Reflux nephropathy i.e. renal scarring associated with vesico-ureteric reflux (VUR) and urinary tract infection (UTI) was originally considered an acquired disease. The renal scarring seems to get worse with recurrent urine infections especially in the young. Therefore, in the past much effort was undertaken to correct the VUR surgically and minimize the number of recurrent urinary tract infections by antibiotic prophylaxis with the hope of reducing if not arresting the onset of complications that follow i.e. hypertension and renal failure. However, it is now becoming clear that reflux nephropathy encompass at least two major categories of disease; "acquired" renal scarring secondary to UTI and VUR predominantly affecting females and "congenital" scarring with dysplastic features associated with prenatal VUR but with no infection and predominantly affecting boys. The latter is much less common but is disproportionately represented in the group of patients with reflux nephropathy that go on to develop renal failure. Unfortunately, the susceptibility to renal scarring, the onset of hypertension and progression to renal failure seems to be significantly influenced by genetic factors and hence measures undertaken to prevent recurrence of UTI may not change the ultimate outcome although it will certainly improve the comfort of the individual. Therefore, the extensive investigation and management routines adopted today in these children may not be cost-effective in preventing end stage renal disease in VUR. The progression to renal failure, however, can be delayed but not halted with adequate control of high blood pressure and hence the need for life long follow-up.