Larvicidal Activity of Tephrosia purpurea, (L) Against the Larvae of Culex quinquefasiciatus.

The aim of this work was to study the larvicidal activity of Tephrosia purpurea (L) Pers. against the larvae of culex quinquefasiciatus. The preliminary laboratory trail was undertaken to determine the efficacy of petroleum ether and ethyl acetate extract of dried whole plant of Tephrosia purpurea belonging to the family Papilionaceae at various concentrations against the late third or early fourth instar larvae of culex quinquefasiciatus by following the WHO guidelines. The results suggest that 100% mortality. Petroleum ether and ethyl acetate extract of Tephrosia purpurea (L) Pers. was observed at 250ppm and 300ppm respectively. The results suggested that use of plants in insect control as an alternative method for minimizing the noxious effect of some pesticide compound on the environment. Thus the extract of Tephrosia purpurea delivers promising more selective and biodegradable agent.

Epidemiology of animal bites and rabies cases in India. A multicentric study.

Rabies, a disease of antiquity continues to be a major public health problem in India. Multiple factors contribute to high mortality and morbidity due to animal bites. An effective strategy for control of rabies takes into account the epidemiology of animal bites, rabies and factors influencing post exposure treatment. The study was carried out as a part of Agreement for Performance of Work (APW) from World Health Organization (WHO) during the period April 2001 to September 2002. Two sets of proformae were developed and used after field testing to interview cases of animal bites and get retrospective information about rabies cases. The study was carried out at six selected centres across the country viz. Delhi, Hyderabad, Raipur, Jamnagar, Coonoor and Rajahmundry and was co-ordinated by National Institute of Communicable Diseases (NICD), Delhi. The officials engaged in the study work were thoroughly trained in the study methodology before the start of the study itself. To maintain quality and uniformity supervisory checks were done during the survey. A total of 1357 fresh animal bite victims were interviewed (exit interview) from the anti-rabies centres (ARCs). Dog bites caused maximum morbidity (92%). Second most common biting animal was monkey (3.2%), followed by cat (1.8%), fox (0.4%) etc. Most bites (64.3%) were unprovoked bites by stray (64.7%) animals. In this study 72.4% animal bite victims were males and 47.5% were children in age group of 2-18 years. 63% had Category III exposure as per the WHO classification. Before coming to ARCs 58.5% people had washed the wound with water/soap or water alone. Some of the bite victims (10.8%) had also applied chillies, salt, turmeric powder, lime, snuff powder, paste of leaves, acid, ash given by Peer Baba (magician) etc. These practices varied from one region to another. The practice of wound washing at the ARC which is an important component of animal bite management was being practiced at only one of the six centres. Of the six centres, Rabies Immunoglobulin (RIG) was available and was being used at only two centres. The study was conducted in public sector ARCs where Nervous Tissue Vaccine (NTV) was available free of cost. All the centres were using NTV except Coonoor, which is using indigenously produced Tissue Culture Vaccine along with NTV. Analysis of 192 case records of rabies cases, from two centres, revealed that dog bites caused maximum mortality (96.9%). Nearly 40% were children below 15 years of age and 78.6% were males indicating that it is an exposure related disease. In all cases, failure to seek timely and appropriate treatment led to development of disease. This paper provides an overview of epidemiology of animal bites and retrospective information about rabies patients. There is a need to strengthen Information, Education and Communication (IEC) programme regarding merits of local wound management including "do's and don'ts". ARCs should be strengthened in terms of facilities and availability of safe and effective anti rabies immunobiologicals. There is a need to create awareness regarding epidemiology and at-home and hospital management of animal bites among the service providers and general community.

Present susceptibility status of rat flea Xenopsylla cheopis (Siphonaptera: Pulicidae), vector of plague against organochlorine, organophosphate and synthetic pyrethroids 1. The Nilgiris District, Tamil Nadu, India.

The susceptibility status of Xenopsylla cheopis, the efficient vector of human plague in India was assessed in erstwhile plague endemic areas of Nilgiris district, Tamil Nadu following standard WHO techniques. The studies revealed the development of resistance in rat fleas to DDT--4.0%, Malathion--5.0%, Deltamethrin--0.05% and tolerance to Permethrin--0.75% in all the four blocks of Nilgiris hill district. Development of resistance may be due to the extensive use of insecticides in tea plantations and agricultural sectors where the domestic/peri-domestic rodents find their natural habitats and intermingle with each other.

Cytoview: development of a cell modelling framework.

The biological cell, a natural self-contained unit of prime biological importance, is an enormously complex machine that can be understood at many levels. A higher-level perspective of the entire cell requires integration of various features into coherent, biologically meaningful descriptions. There are some efforts to model cells based on their genome, proteome or metabolome descriptions. However, there are no established methods as yet to describe cell morphologies, capture similarities and differences between different cells or between healthy and disease states. Here we report a framework to model various aspects of a cell and integrate knowledge encoded at different levels of abstraction, with cell morphologies at one end to atomic structures at the other. The different issues that have been addressed are ontologies, feature description and model building. The framework describes dotted representations and tree data structures to integrate diverse pieces of data and parametric models enabling size, shape and location descriptions. The framework serves as a first step in integrating different levels of data available for a biological cell and has the potential to lead to development of computational models in our pursuit to model cell structure and function, from which several applications can flow out.

Evolutionary insights from suffix array-based genome sequence analysis.

Gene and protein sequence analyses, central components of studies in modern biology are easily amenable to string matching and pattern recognition algorithms. The growing need of analysing whole genome sequences more efficiently and thoroughly, has led to the emergence of new computational methods. Suffix trees and suffix arrays are data structures, well known in many other areas and are highly suited for sequence analysis too. Here we report an improvement to the design of construction of suffix arrays. Enhancement in versatility and scalability, enabled by this approach, is demonstrated through the use of real-life examples. The scalability of the algorithm to whole genomes renders it suitable to address many biologically interesting problems. One example is the evolutionary insight gained by analysing unigrams, bi-grams and higher n-grams, indicating that the genetic code has a direct influence on the overall composition of the genome. Further, different proteomes have been analysed for the coverage of the possible peptide space, which indicate that as much as a quarter of the total space at the tetra-peptide level is left un-sampled in prokaryotic organisms, although almost all tri-peptides can be seen in one protein or another in a proteome. Besides, distinct patterns begin to emerge for the counts of particular tetra and higher peptides, indicative of a 'meaning' for tetra and higher n-grams. The toolkit has also been used to demonstrate the usefulness of identifying repeats in whole proteomes efficiently. As an example, 16 members of one COG,coded by the genome of Mycobacterium tuberculosis H37Rv have been found to contain a repeating sequence of 300 amino acids.

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.

An entomological study on the dengue vectors during outbreak of dengue in Tiruppur town and its surroundings, Tamil Nadu, India.

Tiruppur town and its surroundings of Tamil Nadu state had reported the rise in dengue cases and some deaths during July, 2005. A team from NICD branch, Coonoor investigated the outbreak of dengue during August, 2005. Due to acute scarcity of water, people in Tiruppur town and surrounding rural areas store water in cement tanks and other containers which facilitated the prolific breeding of the dengue vector mosquitoes. The Aedes aegypti adult and larval survey conducted in randomly selected areas and the larval breeding indices and adult mosquito density were found to be above the critical levels. The state health and municipal authorities had initiated the control measures in urban areas. However in rural areas, these measures needed to be sustained and surveillance for dengue cases to be strengthened for timely control and prevention of the future outbreaks of this disease.

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.

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.