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N Balakrishnan

Publications and source records attributed to N Balakrishnan.

29 records · Page 2Linked to original sources
PubMed2004

Two-sample scale tests for comparison of metabolic rates for styrene in previously exposed and unexposed groups.

Statistical analysis procedure in two-sample treatment difference, as well as alternative hypothesis, may play a central role in statistical inference, especially in small sample size case. In this paper, simple non-parametric two-sample permutation tests for scale difference based on the Hodges-Lehmann estimator are reformulated, and are applied to a study examining whether previous styrene exposure increases (thus a one-sided alternative hypothesis rather than a two-sided one) the human liver's metabolic ability to convert styrene into styrene oxide, in which a three-compartment physiologically based pharmacokinetic (PBPK) model was used to compare the estimated metabolic constant kappaamong the previously exposed and unexposed groups. Contrary to the previous conclusion, the proposed tests for scale difference identified from a mixed-effects model showed a significant result.

Humans↗
PubMed2000

Silent spread of dengue and dengue haemorrhagic fever to Coimbatore and Erode districts in Tamil Nadu, India, 1998: need for effective surveillance to monitor and control the disease.

Dengue fever (DF) or dengue haemorrhagic fever (DHF) has not previously been reported in Coimbatore and Erode districts in Tamil Nadu in India. In 1998, 20 hospitalized cases of fever tested positive for dengue virus IgM and/or IgG antibodies. All of them had dengue-compatible illness, and at least four had DHF. Two of them died. Sixteen cases were below 10 years of age. The cases were scattered in 15 distantly located villages and 5 urban localities that had a high Aedes aegypti population. Although the incidence of dengue-like illness has not increased recently, almost 89% (95/107) of samples from healthy persons in the community tested positive for dengue IgG antibodies. The study showed that dengue has been endemic in the area, but was not suspected earlier. A strong laboratory-based surveillance system is essential to monitor and control DF/DHF.

Adolescent↗
PubMed1992

Tc-99m albumin scintigraphy in the localization of protein loss in the gut.

Scintigraphic localization of gastrointestinal protein loss has been recently reported. A noninvasive method for the localization of protein loss in the gut using Tc-99m labeled albumin seems encouraging and is described here. In six patients studied for protein-losing enteropathy, scintigraphic results of four were positive.

Adolescent↗
PubMed1992

Efficacy of bi-annual administration of DEC in the control of bancroftian filariasis.

The efficacy of bi-annual administration of DEC at the dose of 6 mg/kg body weight was evaluated on the microfilaraemia prevalence, density and vector filarial infection rates. Administration of four doses (4 x 6 mg/kg) of DEC significantly (P < 0.05) reduced the microfilaria rate of the community from 6.02 per cent to 2.31 per cent, microfilaria density from 0.66 to 0.17 and infectivity rate of the vector population from 0.8 per cent to 0.39 per cent.

Animals↗
PubMed1989

Prevalence of bancroftian filariasis & its control by single course of diethyl carbamazine in a rural area in Tamil Nadu.

The prevalence of microfilaraemia, clinical spectrum of bancroftian filariasis and vector potential were studied in Vettavalam village in North Arcot district of Tamil Nadu. The effectiveness of selective therapy with diethyl carbamazine (DEC) in controlling filariasis in rural areas was also evaluated. The prevalence of microfilaraemia (mf rate) and disease (disease rate) was found to be 11.7 and 11.09 per cent respectively. Hydrocele was the dominant clinical sign in males and lymphoedema in females. The density of the vector Culex quinquefasciatus was 25.44 females/man-hour, and the infection and infectivity rates were 18.16 and 1.09 per cent respectively. All mf carriers detected after the mass blood survey were given a single course of DEC at the dosage of 6 mg/kg of body wt/day for 12 days. Only 61.6 per cent of them took the full course of DEC treatment. DEC therapy brought down the mf rate from 11.7 to 5.84 per cent after one month. In the absence of further treatment, there was no significant change in mf prevalence after one year.

Adolescent↗
PubMedDate not supplied

Clinical epidemiology of bancroftian filariasis: effect of age and gender.

A cross-sectional survey was used to determine the prevalence of disease (n = 6493) and microfilaraemia (n = 24,946) due to Wuchereria bancrofti in Pondicherry, south India. The total disease attributable to filariasis was significantly higher in males (13.67%) than females (2.26%), due to the occurrence of hydrocele in males. While the prevalence of chronic signs was clearly age-dependent in both sexes, that of acute signs was independent of age. Thus the age and gender structure of the survey sample will crucially influence apparent prevalence. Examination of the gender differences in the point prevalence of disease in 12 areas of India showed a significant relationship between occurrence of disease and gender, but this relationship did not significantly differ between northern and southern Indian populations. The study suggested that the failure to appreciate the importance of age and gender in disease prevalence has led to misconception about disease patterns in India.

Age Factors↗
PubMedDate not supplied

A FAST pattern matching algorithm.

The advent of digital computers has made the routine use of pattern-matching possible in various applications. This has also stimulated the development of many algorithms. In this paper, we propose a new algorithm that offers improved performance compared to those reported in the literature so far. The new algorithm has been evolved after analyzing the well-known algorithms such as Boyer-Moore, Quick-search, Raita, and Horspool. The overall performance of the proposed algorithm has been improved using the shift provided by the Quick-search bad-character and by defining a fixed order of comparison. These result in the reduction of the character comparison effort at each attempt. The best- and the worst- case time complexities are also presented in this paper. Most importantly, the proposed method has been compared with the other widely used algorithms. It is interesting to note that the new algorithm works consistently better for any alphabet size.

Algorithms↗
PubMedDate not supplied

Spectrum of severe chronic kidney disease in India: a clinicopathological study.

BACKGROUND: The healthcare burden due to chronic kidney disease has increased worldwide in the past decade. Elucidating the aetiology of chronic kidney disease may help in identifying strategies for prevention, both in the population and the Individual patient. Only a clinicopathological study can define the exact spectrum of chronic kidney disease since epidemiological studies have not shown a consistent aetiological profile. The histological evidence used to support the diagnosis varies with the degree to which renal biopsy is done. Renal biopsy is the gold standard in making an aetiological diagnosis in renal failure, but as a diagnostic tool in chronic kidney disease it is underutilized. METHODS: This prospective study done at Christian Medical College, Vellore in southern India from 1998 to 2003 aimed to determine the aetiological profile of severe chronic kidney disease by analysing renal biopsies. The value of pre-renal biopsy clinical Judgement in predicting the histological diagnosis was also assessed. Patients with diabetic nephropathy were excluded from the study. RESULTS: Four hundred and fifty-seven patients had evidence of chronic kidney disease as evidenced on biopsy as well as on clinical parameters. Three hundred and twenty-two of these patients (70.5%) had glomerulonephritis as the histological diagnosis. Fifty-five (12%) had Interstitial nephritis, 30 (6.6%) had hypertensive arteriosclerosis and 28 (6.1%) had metabolic nephropathies. The positive predictive value of a pre-biopsy clinical diagnosis in predicting interstitial nephritis was very low (33%). A large number of patients clinically diagnosed to have chronic interstitial nephritis had other aetiologies of chronic kidney disease. CONCLUSION: Glomerulonephritis was the most common cause of chronic kidney disease, not including diabetic nephropathy, followed by interstitial disease and benign arterionephrosclerosis. In patients with unidentified severe chronic kidney disease, renal biopsy provided an aetiological diagnosis.

Adult↗