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Biomedical subjects

K N Panicker

Publications and source records attributed to K N Panicker.

At least 19 recordsLinked to original sources
PubMed1998

Susceptibility status of Mansonia annulifera to Brugia malayi parasites in Cherthala, Alappuzha district, Kerala.

Laboratory studies conducted on Ma. annulifera collected from Cherthala region, Kerala, endemic for Brugian filariasis indicated that this species is highly susceptible to B. malayi parasites. The experimental infection index of this species was relatively higher (2.74). No significant loss of larvae during development was recorded. The extrinsic incubation period was estimated to be 8 days.

Animals↗
PubMed1997

Current status of filariasis in Chavakad taluk, Trichur district, Kerala.

A sample survey using parasitological, clinical and entomological indicators was carried out in all the 18 administrative units of Chavakad taluk, Trichur district, Kerala, India to assess the current filariasis situation. Cluster sampling procedure was followed to screen individuals. Both Wuchereria bancrofti and Brugia malayi species were found to be prevalent in this taluk. Microfilaria (mf) carriers with W. bancrofti were detected in eight areas while B. malayi was recorded only from one area. The two species were found to co-exist in another area. The highest infection rate registered for W. bancrofti was 1.51 while it was 0.3 for B. malayi. Infection due to W. bancrofti constituted 87.88% of the total 33 microfilaria cases. Prevalence of B. malayi was very low. Cases with clinical manifestation of filariasis were recorded in all the four areas surveyed. The present trend in the prevalence of infection (mf) and disease showed a decline in both the species when compared to earlier surveys of 1960s. At least 11 areas are still endemic for filariasis in this taluk. Although prevalence of mf was recorded for the first time in one of the areas viz., Elavalli, the rate was only 0.16%. Entomological surveys revealed the presence of 14 mosquito species, of which Culex quinquefasciatus contributed 84.85% and Mansonia 0.77%. While C. quinquefasciatus was recorded in all the 18 areas, Mansonia spp were found only in 8 areas. Only C. quinquefasciatus was found to harbour different developmental stages of W. bancrofti, with overall infection and infectivity rates of 1.94 and 0.97 respectively. The possible reason for the decline in vector density and infection in man are postulated.

Adolescent↗
PubMed1996

Mattancherry urban agglomeration, a diminishing focus of lymphatic filariasis in Kerala.

Parasitological survey conducted recently in Mattancherry, Kerala showed a low prevalence of microfilariae (mf), with a mf rate of 1.81%, compared to that of 1956 when the mf rate was 14.7%. No brugian infection was encountered in the present investigation, though both bancroftian and brugian infections were reported earlier. Culex quinquefasciatus, the vector of bancroftian filariasis was the most predominant (93.3%) mosquito species, and its infection and infectivity rates were 0.76% and 0.54% respectively. Mansonioides spp., the vectors of brugian filariasis constituted only 0.2% of the total mosquitoes and with no infection. The overall reduction in the prevalence of mf cases and vector infection rates over the years is attributed to the continued activities of the National Filaria Control Programme. The disappearance of brugian filariasis could mainly be due to the drastic reduction in the Mansonioides breeding habitats, as a result of rapid urbanization coupled with improved socio economic conditions.

Animals↗
PubMed1996

Brackish water mosquito problem of Vypeen Island, Cochin, Kerala.

A preliminary study has shown that the marshy terrain and brackish water bodies associated with mangrove forests contributed profuse breeding of mosquitos in Vypeen island, causing a severe menace to the island population. A total of 14 species belonging to four genera viz, Aedes, Anopheles, Armigeres and Culex was recorded from different habitats. Culex sitiens was found to be the predominant mosquito in all the perennial breeding habitats. The extent of different habitats in the production of mosquitos, and its possible abatement, using environmental and/or biocontrol methods are discussed.

Animals↗
PubMed1995

Emblica officinalis: a novel therapy for acute pancreatitis--an experimental study.

Acute necrotising pancreatitis is associated with an unacceptably high mortality for which no satisfactory remedy exists. Emblica officinalis (E.o.) is a plant prescribed in Ayurveda, the Indian traditional system of medicine, for pancreas-related disorders. This study was carried out to evaluate the protective effect of E.o. against acute necrotising pancreatitis in dogs. Pancreatitis was induced by injecting a mixture of trypsin, bile and blood into the duodenal opening of the pancreatic duct. Twenty eight dogs were divided into 4 groups (n = 6-8 each): GpI--control, GpII--acute pancreatitis, GpIII--sham-operated, GpIV--pretreatment with 28 mg E.o./kg/day for 15 days before inducing pancreatitis. Serum amylase increased from 541.99 +/- 129.13 IU/ml to 1592.63 +/- 327.83 IU (p <0.02) 2 hrs after the induction of pancreatitis in GpII. The rise in serum amylase in both GpIII and GpIV was not significant. On light microscopic examination, acinar cell damage was less and the total inflammatory score was significantly lower in the E.o. treated group as compared to GpII. Electron microscopy confirmed this and showed an increased amount of smooth endoplasmic reticulum and small, condensed granules embedded in a vacuole. More studies are needed to explore the clinical potential of E.o. and its mechanism of action.

Acute Disease↗
PubMed1995

Response of gravid Phlebotmus papatasi females to an oviposition attractant/stimulant associated with conspecific eggs.

Oviposition response of gravid P. papatasi females to conspecific eggs was studied in laboratory colonized sandflies. It was observed that significantly higher number of eggs were laid in the vicinity of conspecific eggs. However, a certain minimum number of eggs were required to be placed on the substratum to influence the rate of oviposition. The fecundity of females (mean = 56.5 +/- 4.9 eggs) exposed to conspecific eggs was significantly higher (P < 0.05) than that of blank control group. Perhaps, the chemical substances/pheromone of egg origin stimulated the oviposition rate. In an attempt to isolate the active ingredient, solvent washing of the conspecific eggs were tested. No increase in the rate of oviposition was noticed when the test site was treated with distilled water extract, whereas, significantly larger number of eggs were laid at the site treated with di-ethyl ether extract. This indicated that the oviposition attractant associated with the eggs dissolved in the organic solvent, but not in water. The possible application of this attractant for wild sandflies in nature and for regulating the site of oviposition on the substratum in the laboratory colonized sandflies needs to be explored.

Animals↗
PubMed1994

Relative potency of DEPA as a repellent against the sandfly Phlebotomus papatasi.

The insect repellent N,N-diethylphenylacetamide (DEPA) was compared with two commercial repellents, N,N-diethyl-m-toluamide (DEET) and dimethyl phthalate (DMP), for protection against 3-day-old unfed females of the sandfly Phlebotomus papatasi (Scopoli) under laboratory conditions, using host rabbits. Both DEPA and DEET were found to be more effective than DMP, but there was no significant difference between the efficacy of DEPA and DEET.

Acetamides↗
PubMed1994

Aquatic vegetation and their natural hospitability to the immatures of Mansonia mosquitos, the vectors of Brugia malayi in Shertallai, Kerala, India.

Prevalence of various aquatic vegetation and their role in supporting vector breeding were studied by drawing plant samples from natural fresh water habitats in Shertallai region which is endemic for Brugia malayi. As many as 30 aquatic plant species were identified in addition to the most abundant and preferred host plants such as Pistia stratiotes, Salvinia molesta and Eichhornia crassipes which are of major concern due to their contribution for vector proliferation. Fallow lands and paddy fields recorded relatively a higher number of plant species. Natural breeding of Mansonia, the vector mosquitos was observed in 16 of them. Using the data on the prevalence, proportion of samples positive for Mansonia breeding and immature density, two indices viz, natural hospitability Index (NH) and Mansonia host plant Index (MHI) were developed for each plant species. Ranking of these plants in relation to Mansonia breeding was done based on these indices. Monochoria vaginalis has been identified to be one of the most important auxiliary host plant. Three grasses viz, Hygrorhiza aristata, Sacciolepis interrupta and Leersia hexandra were found to support all the three species of Mansonia viz, Ma. annulifera, Ma. uniformis and Ma. indiana with considerable immature density. The inclusion of these plants for weed/vector control is emphasized.

Animals↗
PubMed1994

Ultrastructural changes in mild gastroesophageal reflux disease: results of a pilot study.

Few studies have examined the ultrastructural changes in mild reflux esophagitis. Endoscopic esophageal biopsies were obtained from 10 patients with reflux symptoms and mild endoscopic esophagitis (grade 0:3 patients, grade I: 7 patients) and 9 patients with erosive esophagitis (grade II-IV), at least 5 cm above the Z line. The biopsies were evaluated by light and transmission electron microscopy. Ultrastructural changes were present in one patient with grade 0, 7 with grade I and 9 with grade II-IV esophagitis. Four of the 10 patients with grade 0-I esophagitis and 6 of 9 with grade II-IV esophagitis had light microscopic abnormalities. The ultrastructural abnormalities in patients with mild esophagitis were seen in the cell membrane, cytoplasmic organelles, desmosomes, and nuclei of all the three layers of esophageal mucosa and the basal lamina. Ultrastructural studies by transmission electron microscopy on endoscopic pinch biopsies may be a sensitive research tool to study the pathogenesis of mild reflux esophagitis.

Adult↗
PubMed1993

Population dynamics of Phlebotomus papatasi (Diptera:Phlebotomidae) in Pondicherry, India.

Investigations on the population dynamics of Phlebotomus papatasi were carried out. The average indoor resting density fluctuated between 16.70 and 2.25/man-hour in different seasons with a maximum density during monsoon season. There was a significant positive correlation between density and rainfall. Probability of daily survival of adult population was high in monsoon and low in summer. Both relative humidity and temperature influenced the survival. The finite rate of natural increase of the field population was maximum in October and minimum in April. The monsoon season, with moderate temperature and relative humidity was found to be favourable for the growth of P. papatasi population.

Animals↗
PubMed1993

Laboratory observations on the biology of the phlebotomid sandfly, Phlebotomus papatasi (Scopoli, 1786).

Investigations on the biology of Phlebotomus papatasi were carried out under laboratory conditions at 28 +/- 2 degrees C and 80 +/- 1% RH. Fecundity of the female varied between 61 and 48 (mean 56.2 +/- 5.46) and the incubation period of eggs ranged from 7-9 (mean 7.81 +/- 0.61) days. The developmental duration of larvae and pupae varied from 24 to 31 (mean 28.57 +/- 2.71) and 9 to 11 (mean 10.38 +/- 1.51) days, respectively. The rate of insemination, determined from the females that laid fertile eggs, was found to be maximum when the females were three days old. Autogeny was observed from female sandflies, emerged from the larvae fed on animal liver powder. The duration of first and second gonotrophic cycles under ambient conditions was shortest in summer and longest in winter. Studies on adult longevity showed that the females fed on mouse blood survived for 6 to 27 days (mean 14 +/- 12.5 days).

Age Factors↗
PubMed1992

Biting rhythm & biting activity of phlebotomid sandflies.

The biting behaviour of Phlebotomid sandflies was studied in a rural village of Pondicherry through all night collections for a period of one year, using human volunteers and cattle as baits. Phlebotomus papatasi was caught only on human bait, showing anthropophily while Ph. argentipes was caught on cattle baits, showing zoophily. The biting activity was seen throughout the night, reaching a peak of 0100 h in Ph. papatasi and 0200 h in Ph. argentipes.

Animals↗
PubMed1992

An improvised method of laboratory colonization of Phlebotomus papatasi, the vector of cutaneous leishmaniasis.

A cyclic colony of P. papatasi was successfully established, using wild caught females. The major obstacle in the colonization was infestation of fungus, which was solved when bentonite, a dehydrant was mixed in the larval diet i.e., powdered and sterilized faecal pellets of rabbit. The average duration of development from egg to adult was 46.41 +/- 3.26 days. Females readily engorged on mouse, which was kept immobilized inside restrainer cages Majority of the fed females laid viable eggs, when confined in improvised styro-foam humidity chambers and survived after oviposition. In this process a stable, cyclic colony was established and it is now in F39 generation.

Animals↗
PubMed1992

Occurrence of entomophilic nematode infestation among phlebotomid sandfly, Phlebotomus papatasi--a preliminary report.

Infestation of a nematode parasite was observed in the natural population of Phlebotomus papatasi in Pondicherry, India. Of the 877 males and 959 females sandflies examined for the natural infection, 11 females were found infested with nematodes (0.59%). The number of juveniles and/or eggs of nematodes per infected fly ranged from 1 to 192 (mean 51.36 +/- S.D 55.95). The presence of a stylet at the opening of the dorsal oesophageal duct suggests that the parasite belongs to the super family Tylenchoidea.

Animals↗
PubMed1992

Effectiveness of slow release formulations of fenthion (Baytex) in the control of Mansonia breeding in polluted pond habitats.

Effectiveness of two types of granular formulations of fenthion (Baytex) was evaluated in controlling the breeding of Mansonia mosquitos in polluted pond habitats. Calcium carbonate and sand granular formulations, when applied at 2.50 g/m2 surface area with an average depth of 0.5 m were found to be effective in keeping the habitats completely free from Mansonia breeding for 14 days and 18 days respectively. Release of insecticide was slow and the effective duration of control after a single application was relatively longer in the sand formulation when compared to the calcium carbonate formulation. Single application of calcium carbonate and sand granular formulations of fenthion could effectively prevent Mansonia adult emergence for 23 and 30 days, respectively in polluted pond habitats, without causing any adverse effect on non-target insects.

Animals↗
PubMed1992

Larvivorous potential of some indigenous fishes of Sherthallai region with special reference to their efficacy in control of mansonioides.

Larvivorous potential of some indigenous fishes collected from natural habitats of Sherthallai region in Kerala state, India, was studied under laboratory as well as controlled field conditions. Ophiocephalus striatus was observed to consume significantly higher number of mansonioides larvae (354/g body wt/day), followed by Macropodus cupanus (231/g body wt/day). The proportion of adult vector mosquito emergence was significantly (P less than 0.05) lower in cages with fish species studied, as compared to that of control group of cages without fishes. Natural food preference of the selected fish species was also studied indirectly through gut content analysis.

Animals↗