Larvicidal and mosquito repellent activities of Pine (Pinus longifolia, family: Pinaceae) oil

BACKGROUND AND OBJECTIVES

Various plant-based products are safe and biodegradable alternatives to synthetic chemicals for use against mosquitoes. Oil of Pinus longifolia is traditionally used for protection against mosquitoes in some rural areas but there is no documented report of its use against mosquitoes. The present study was undertaken to scientifically evaluate the activity of Pine oil against mosquitoes.

METHODS

The oil was procured from the market and its contents were chemically analysed. Larvicidal activity of oil was tested in laboratory bioassays, while repellent action was studied during whole night bait collections in field by direct application on the skin and after its impregnation on mats.

RESULTS

Results showed varying degree of larvicidal activity of Pine oil against mosquitoes with LC50 values ranging between 82 and 112 ppm. The Pine oil had strong repellent action against mosquitoes as it provided 100% protection against Anopheles culicifacies for 11 h and 97% protection against Culex quinquefasciatus for nine hours respectively. Electrically heated mats prepared from Pine oil provided, 94 and 88% protection against An. culicifacies and Cx. quinquefasciatus for 10 and seven hours respectively. INTERPRETAION AND CONCLUSION: Pine oil is effective against mosquito larvae at very higher doses which are not of any practical utility. However, Pine oil showed strong repellent action against An. culicifacies (malaria vector) and Cx. quinquefasciatus (pest mosquito). Thus its use could be popularised as mosquito repellent.

Efficacy of IGR compound Starycide 480 SC (Triflumuron) against mosquito larvae in clear and polluted water

BACKGROUND AND OBJECTIVES

An environmental friendly formulation Starycide 480 SC (Triflumuron-OMS-2015 ), a new insect growth regulator with chitin synthesis inhibitor type mode of action was evaluated against mosquito larvae in laboratory and small-scale field trials carried out in and around Delhi.

METHODS

The formulation was tested in laboratory for its bio-efficacy against late III instar mosquito larvae of different species using WHO bioassay procedure. In the field formulation was sprayed at doses of 0.3, 0.5 and 1 ppm (g/m3) in the natural breeding habitats of Anopheles and Culex mosquitoes. The impact was assessed by monitoring densities of larvae by dipper and observing the reduction in larval density and inhibition of adult emergence.

RESULTS

In the laboratory, formulation was more effective against larvae of Anopheles stephensi and Aedes aegypti than Culex quinquefasciatus, but it produced 100% inhibition of adult emergence for all mosquito species at a concentration of 0.02 ppm. In the field trials, formulation did not produce 100% reduction in the density of late stage larvae even at 1 ppm (g/m3), the highest dose tested, but it resulted in 100% inhibition of pupal formation of both Anopheles and Culex spp in different types of habitats for 3-7 weeks even at a lower dose of 0.5 ppm.

INTERPRETATION AND CONCLUSION

Application of triflumuron in the natural breeding habitats in both clean and polluted water @ 0.5 ppm (g/m3) resulted in complete inhibition of adult emergence of both Anopheles and Culex spp for 3-7 weeks. This formulation may be tested in large-scale field trials for further use in the vector control programme.

Therapeutic efficacy of antimalarial drugs along the eastern Indo-Nepal border: a cross-border collaborative study

This collaborative cross-border study was performed to determine the therapeutic efficacy of antimalarial drugs used by the National Programmes for falciparum malaria along the eastern Indo-Nepal border where there is unregulated population movement across the border. The study was conducted at sites in Jhapa District, Nepal and Darjeeling District, India. The study was conducted from August 2003 to February 2004, following the WHO 28 day treatment protocol. The efficacy of chloroquine was tested in India among 91 subjects and of sulfadoxine-pyrimethamine in Nepal among 107 subjects with laboratory-confirmed Plasmodium falciparum malaria. Of the 102 subjects who completed the study in Nepal, there were 21 (20.6%) treatment failures comprising 7 (6.9%) early treatment failures (ETF) and 14 (14.7%) late treatment failures (LTF) (5 late clinical failures [LCF] and 9 late parasitological failures [LPF]). Of the 89 subjects who completed the study in India, there were 46 (51.7%) treatment failures comprising 7 (7.9%) ETFs and 39 (43.8%) LTFs (13 LCFs and 26 LPFs). Based on WHO guidelines both countries need to review their drug policy urgently and make appropriate changes, taking into account aspects of cross-border collaboration in the control of drug-resistant malaria.

Impact of residual spraying of Reldan against Anopheles culicifacies in selected villages of District Ghaziabad (Uttar pradesh), India

BACKGROUND & OBJECTIVES

Indoor residual spraying of Reldan 40% EC @ 0.5 and 1 g/m2 was done in Tatarpur and Chauna villages, respectively in Dhaulana PHC, Distt. Ghaziabad (U.P.) to evaluate its impact against Anopheles culicifacies and malaria incidence. Results were compared with that of Piyawali village which was taken as control area.

METHODS

Four rounds of spray were done from 1999--2000 in human dwellings and cattlesheds in experimental villages. Entomological parameters--man hour density, parity rate, sporozoite rate, etc. were monitored using standard procedures. Epidemiological indicators such as SPR, SFR, cases/000, Pf/000 were also calculated. Cone bioassays as per WHO method were also carried out to assess the persistence of the insecticide on different surfaces.

RESULTS

Entomological results revealed that spraying of reldan @ 0.5 g/m2 resulted in significant reduction in adult densities of An. culicifacies in sprayed villages over the control village. Spraying also resulted in reduction of percent parous females, reduction in malaria incidence (p < 0.05).

INTERPRETATION & CONCLUSION

Reldan showed high efficacy @ 0.5 g/m2 in controlling the densities of An. culicifacies and malaria incidence. However, double dosage of reldan @ 1 g/m2 can be used for comprehensive vector control provided > 95% spray coverage is achieved.

Selection of a highly virulent fungal isolate, Metarhizium anisopliae CLO 53, for controlling Hoplia philanthus

The June beetle, Hoplia philanthus Füessly (Coleoptera: Scarabaeidae), has become a widespread and destructive insect pest of lawns, sport turf, pastures, and horticultural crops in Belgium. The virulence of 34 entomopathogenic fungal isolates from the genera Metarhizium, Beauveria, and Paecilomyces to third-instar H. philanthus was tested in bioassays by dipping larvae in 10(7)conidia/ml suspensions. Two isolates of Metarhizium anisopliae (CLO 53 and CLO 54) caused maximally 90% mortality 10 weeks post-inoculation while other isolates only caused mortalities between 10 and 62%. The virulence of M. anisopliae CLO 53 was further tested by exposing H. philanthus larvae to conidial serial concentrations of 10(4)-10(9)conidia/g sandy soil for up to 11 weeks at 15, 20 or 25 degrees C. Mortality was dependant on the fungal concentration, exposure time, and temperature. Eleven weeks after inoculation, the LC50 values for this isolate ranged from 1.3 to 4.0 x 10(6), 1.0 to 3.2 x 10(5), and 2.5 x 10(4) to 10(5)conidia/g soil at 15, 20, and 25 degrees C, respectively. The LT50 values for this isolate ranged from 3.5 to 21.7, 2.4 to 18.7, and 2.9 to 16.1 weeks at concentrations of 10(9) and 10(4)conidia/g soil at 15, 20, and 25 degrees C, respectively. In glasshouse pot experiment with perennial ryegrass (Lolium perenne L.), the isolate CLO 53 caused mortalities of 50 and 88% of H. philanthus larvae 10 weeks after application of 10(4) and 10(6)conidia/cm(2) soil surface, respectively. The present results suggest that the Belgian isolate CLO 53 has excellent potential for biological control of H. philanthus.

Evaluation of pirimiphos-methyl (50% EC) against the immatures of Anopheles stephensi/An. culicifacies (malaria vectors) and Culex quinquefasciatus (vector of bancroftian filariasis)

BACKGROUND & OBJECTIVES

In India, temephos and fenthion are used as larvicides in fresh and polluted waters. Since use of same insecticide may precipitate resistant, as an alternative bioefficacy of pirimiphos-methyl--an organophosphorus insecticide was evaluated against immatures of Anopheles and Culex species in different breeding habitats in District Ghaziabad (U.P.) and Goa.

METHODS

Laboratory bioassays were carried out using standard WHO procedure. LC50 and LC90 were calculated using Probit analysis. Abbott's formula was used to calculate per cent corrected mortality in laboratory exposures while, Mulla's formula was applied for calculating per cent reduction in mosquito immatures under field conditions.

RESULTS

Pirimiphos-methyl was found to be most effective against larvae of An. stephensi followed by An. culicifacies and Cx. quinquefasciatus. The LC50 and LC90 values against three species were 0.023, 0.032 and 0.04 ppm; and 0.045, 0.057 and 0.114 ppm respectively. In field, pirimiphos-methyl @ 200 g a.i./ha against Anopheles species and @ 300 g a.i./ha against Culex species can produce > 80% reduction in density of immatures up to one week in different habitats. Pirimiphos-methyl < 0.25 ppm is not toxic to fish.

INTERPRETATION & CONCLUSION

Pirimiphos-methyl is more effective against anophelines in clean water than culicines in polluted water. This larvicide should not be used at a concentration above 0.25 ppm in habitats harbouring the larvivorous fish.

Evaluation of repellent action of Cymbopogan martinii martinii Stapf var sofia oil against Anopheles sundaicus in tribal villages of Car Nicobar Island, Andaman & Nicobar Islands, India

A field study was carried out to evaluate the mosquito repellent action of Cymbopogan martinii martinii Stapf var sofia oil in tribal village of Car Nicobar Island. Results revealed that application of 1 ml of the oil provided 98.7% protection in indoor and 96.52% in outdoor conditions during 12 h period of observation from the bites of An. sundaicus. Cymbopogan martinii martinii Stapf var sofia oil is an indigenous product, its application is safe and can be widely used for protection from malaria.

Prevalence of the K76T mutation in the pfcrt gene of Plasmodium falciparum among chloroquine responders in India

Chloroquine-resistant Plasmodium falciparum needs to be monitored in the field for effective malaria control strategies. A point mutation K76T in the P. falciparum chloroquine resistance transporter (Pfcrt) protein has recently been proposed as a molecular marker for the faster detection of chloroquine-resistant falciparum malaria in field. We describe here the evaluation of this marker in Indian P. falciparum isolates. A total of 274 Indian P. falciparum isolates were analyzed for the K76T mutation. This mutation was detected in all the clinical isolates obtained from the in vivo chloroquine non-responders. But majority of the clinical isolates from chloroquine responders (71 of 74 patients, i.e. 96%) also harbored this mutation. The K76T mutation was indeed highly prevalent (91%) among 213 clinical isolates. There was a significant association between K76T mutation and the in vitro chloroquine response (P<0.05) but six isolates showed discordant results. In conclusion, the K76T mutation fails to differentiate majority of the chloroquine responders from that of the non-responders and thus will be of limited use in the field in India.

Bio-efficacy and operational feasibility of alphacypermethrin (Fendona) impregnated mosquito nets to control rural malaria in northern India

Bio-efficacy and operational feasibility of alphacypermethrin treated nets was evaluated in certain villages of District Ghaziabad (U.P.). Results revealed that poly-filament nylon nets treated with alphacypermethrin suspension concentrate (g/l) formulation @ 25 mg/m2 has shown repellent action (26.5 +/- 8.1), excito repellent action (93.7 +/- 8.1) and killing action (100%) against An. culicifacies landed on treated nets. Significant reduction in indoor resting density of An. culicifacies in human dwellings was also observed in treated nets village (p < 0.05). Instant killing action of treated nets did provide complete protection to inhabitants sleeping inside the net from An. culicifacies bites. The persistent use of nets by the inhabitants has also resulted significant reduction in malaria cases (p < 0.05). It was interesting to note that not even a single case of falciparum malaria was observed after distribution of treated nets in spite of the fact that at no point of time cent per cent compliance of net usage was observed during the study period. Bio-assay tests revealed that treated nets can produce up to 70% mortality in An. culicifacies for about 22 weeks and as such only one treatment with insecticide is required in a year in seasonal transmission area to protect from malaria. The study also revealed that treated nets can be stored at room temperature for about 10 months without loosing their efficacy suggesting thereby that malaria outbreaks can be tackled by the nets if adequate treated nets are stored in core problem districts. It was also revealed that An. culicifacies is a late night biter and as such treated nets can be used successfully against this species.

Bioecology of An. philippinensis in Andaman group of islands

Studies on bioecology of An. philippinensis a vector of malaria was carried out in eight islands of the Andaman group. It was found that An. philippinensis preferred to rest and bite outdoors. Maximum biting was observed during 1800 to 2100 hrs on both cattle and human bait. The maximum breeding of An. philippinensis was recorded in slow moving stream followed by ponds with vegetation. The breeding sites infested with Chara and Spirogyra algae were most favourable whereas, with Lemna and Oscillatoria were unfavourable for the proliferation of this species. The breeding association of An. philippinensis was found with other seven anopheline species in different breeding habitats.

Operational feasibility and bio-efficacy of alphacypermethrin (Fendona) treated jute curtains to control urban malaria in a slum settlement of Delhi, India

Operational feasibility and bio-efficacy of alphacypermethrin treated curtains was evaluated in slum settlements of Andrews Ganj, New Delhi. Jute curtains treated with alphacypermethrin @ 100 mg/m2 were fixed on windows, doors and eves before on set of transmission and evaluations were carried out for two years. Entomological evaluation revealed that jute curtains treated with alphacypermethrin in Slum-I resulted drastic reduction in daytime indoor resting mosquitoes such as An. stephensi, Ae. aegypti and Cx. quinquefasciatus. Similarly, malaria incidence also reduced in the treated curtain used area when compared to that of in untreated curtain and without curtain areas. Bioassay tests on An. stephensi and Cx. quinquefasciatus showed that alphacypermethrin could produce > 70 per cent mortality up to six months in case of An. stephensi--a principal urban malaria vector and hence two rounds of treatment are sufficient in an year to protect inhabitants from malaria. The study indicates alphacypermethrin treated curtains could curtail malaria transmission in slum settlements and is operationally feasible in small houses and is also cost-effective.

Mosquito fauna and breeding habitats of anophelines in Little Andaman Island, Andaman and Nicobar Islands, India

A total of 37 species of mosquitoes belonging to nine genera--Anopheles, Aedes, Armigeres, Culex, Harpagomyia, Mansonia, Orthopodomyia, Toxorhynchites and Uranotaenia were collected from Little Andaman Island. Mosquitoes of nine Anopheles group of species--An. barbirostris, An. barbumbrosus, An. balabacensis, An. insulaeflorum, An. kochi, An. philippinensis, An. roperi, An. sundaicus and An. vagus were recorded. An. philippinensis was found to be the most predominant species. Species-specific breeding preference and association in various types of acquatic habitats have been reported. This is the first record of mosquito fauna of Little Andaman Island.

Allelic variation in the cg2 gene does not correlate with chloroquine resistance among Indian Plasmodium falciparum isolates

The cg2 gene of Plasmodium falciparum has been proposed to be associated with chloroquine resistance. Here we describe PCR amplification and sequencing of all the four repeat regions (kappa (kappa), gamma (gamma), psi (psi) and omega (omega)) of this gene, from Indian isolates. There were variant forms for each of these repeat regions (two for kappa and gamma, and three for psi and omega) among the 123 Indian isolates of P. falciparum. Among these isolates certain forms of psi and omega repeats were uniquely present while some of the reported forms of the kappa and omega repeats were absent. The pattern of combination of all four repeat regions of cg2 gene (genotype) was analysed from 52 isolates. A total of 11 different genotypes were observed among these cases, of which 10 were unique to Indian isolates. Certain genotypes were more common than others. The nucleotide sequencing of all the four repeat regions revealed that Indian isolates have some unique repeating units within the gamma and omega domains. Altogether, the PCR and sequencing results showed that there was an unrelatedness between cg2 repeats and chloroquine resistance.

Epidemiologic investigations of a malaria outbreak in northern Delhi area

Epidemiologic investigations revealed a 56.7 and 13.32% slide positivity rate in febrile and afebrile malaria cases, respectively. In both cases, Plasmodium falciparum was predominant. Anopheles culicifacies resistant to dichlorodiphenyltrichloroethane and benzene hexachloride (hexachlorocyclohexane) was found breeding profusely in pools and ponds created by excavation of earth around brick kiln in the region. Furthermore, children were not found to be producing significant levels of antibodies and a large percentage of patients harbored chloroquine-resistant parasites. Also, more than 1 P. falciparum strain was present in the population. We detected 2 strains, VI and VII, of which type VI was predominant.

Correlation between AgNOR count and subjective AgNOR pattern assessment score in cytology and histology of breast lumps

OBJECTIVE

To find the correlation of argyrophilic nucleolar organizer region (AgNOR) count and subjective AgNOR pattern assessment (SAPA) score in cytology and histology of breast lumps.

STUDY DESIGN

The study group consisted of 73 patients (46 malignant, 27 benign) with breast lumps. In all cases, fine needle aspiration cytology (FNAC) samples and histologic specimens were studied by conventional and silver staining for AgNORs.

RESULTS

AgNOR count and SAPA score were helpful in differentiating benign from malignant tumors in both the cytologic smear and histologic specimen. AgNOR count was 6.94+/-2.74 in FNAC and 6.57+/-2.73 in histology of malignant tumors, while in benign tumors it was 2.75+/-0.74 in FNAC and 2.68+/-0.77 in histology. SAPA score was 9.02+/-4.60 in FNAC and 8.76+/-2.34 in histology in malignant tumors and 5.87+/-0.93 in FNAC and 5.82+/- 0.83 in histology in benign tumors.

CONCLUSION

Both AgNOR count and SAPA score gave similar results, but SAPA score is a more convenient, reproducible and rapid method of AgNOR evaluation.

Lessons to be learned: a case study approach. Paraganglioma of the urinary bladder

Primary paraganglioma arises infrequently in the urinary bladder. We present here the clinicopathological, immunohistochemical and ultrastructural findings in a 23-year-old Saudi female. She was hospitalised because of gross haematuria over the previous seven days. The intravenous urogram revealed a filling defect in the urinary bladder. Cystoscopy disclosed a non-papillary tumour arising from the roof of the bladder neck. Transurethral resection was, accordingly, performed--but marked fluctuation in blood pressure was observed during the procedure. The histopathological findings of trabeculae and small nests of plump oval to spindle cells with a clear to acidophilic cytoplasm, forming an organoid pattern and demonstrating inconspicuous mitotic activity, were diagnostic of paraganglioma of the urinary bladder, the diagnosis was confirmed by means of immunohistochemical and ultrastructural studies. The endocrine markers chromogranin A and neuron-specific enolase were positive in chief cells; sustentacular cells at the periphery of neoplastic cell clusters were positive for S-100 protein. Neurosecretory granules were identified by electron microscopic examination. It is emphasised that, currently, there are no anatomico-pathological criteria to distinguish benign and malignant forms of the disease. Post-surgical recovery was uneventful in this case. Recurrence and metastases, though infrequent, have been reported in the literature; therefore, radiation therapy may be an important adjunct--and long-term follow-up is mandatory.

Concurrent control of mosquitoes and domestic pests by use of deltamethrin-treated curtains in the New Delhi Municipal Committee, India

A field trial was conducted in Block F of the Moti Bagh area of New Delhi Municipal Committee to demonstrate composite control of Anopheles stephensi and Aedes aegypti by spraying deltamethrin at 100 mg/m2 on window and door curtains of habitations. Results revealed drastic reduction (87.9-93.7%, P < 0.05) of target species in the experimental area. The impact of deltamethrin-treated curtains was also evident against nontarget species (67.9-85.7%. P < 0.05). Treated curtains provided 100% kill of An. stephensi and Ae. aegypti for 3-4 months, followed by a gradual decline in successive months. Use of deltamethrin-treated curtains resulted in 92.0 reduction in slide positivity rate and 95.4% reduction in malaria cases per thousand population. The cost of deltamethrin treatment was Rs 41.15 (<$1 U.S.) per house per annum. Insecticide-treated mosquito window and door curtains, along with legislative measures, may provide cost-effective concurrent control of mosquitoes and other domestic pests.

An outbreak of Plasmodium falciparum malaria due to Anopheles minimus in central Assam, India

Epidemiological investigations were conducted in Nellie subcentre, PHC Jhargaon, under Morigaon district (Assam). The results of fever cases revealed 68 per cent slide positivity rate (SPR) and 40 per cent slide falciparum rate (SfR). The Pf proportion was > 87 per cent and remaining cases were P. vivax infections. An. minimus was incriminated as a malaria vector during the study period. The sporozoite rate was 3.08 per cent. The indoor man mosquito contact was 35 per bait/night as against 23 in outdoors. Results of susceptibility test revealed that the vector was still susceptible to both DDT and malathion at discriminating dosages. The study revealed that inadequate surveillance and vector control measures were contributing factors for malaria outbreak. In view of this, insecticide treated nets may be introduced to provide cost-effective control of malaria.

Synthesis of arene-soluble mixed-metal Zr/Ce, Zr/Y, and related [[Zr2(OiPr)9]LnX2]n complexes using the dizirconium nonaisopropoxide ligand

The utility of polydentate monoanionic [Zr2(OiPr)9]- in generating arene-soluble, unsolvated, mixed-metal Zr/Ce and Zr/Y complexes is described. The synthesis of other mixed-metal zirconium lanthanide complexes was also studied to explore the relationship of metal size to structure. Lanthanide trihalides react in THF with KZr2(OiPr)9 to form unsolvated dimers, [[Zr2(OiPr)9]LnCl2]2, with the larger metals, Ln = Ce (1), Ho (2), Y (3), and unsolvated monomers, [Zr2(OiPr)9]LnCl2, with the smaller elements, Ln = Er (4), Yb (5). The synthesis of a monomeric iodide analogue, [Zr2(OiPr)9]TmI2, 6, by reduction of Zr2(OiPr)8(iPrOH)2 with TmI2(DME)3 is also reported. In all of these complexes, the [Zr2(OiPr)9]- subunit is tetradentate. 1-6 are compared with related cyclopentadienyl halide complexes to evaluate the special features of the dizirconium nonaisopropoxide ligand versus cyclopentadienide.

Effect of prenatal glucocorticoid on fetal lung ultrastructural maturation in hyt/hyt mice with primary hypothyroidism

Glucocorticoids (GC) and thyroid hormones (TH) accelerate fetal lung maturation. Though GC are used clinically, the mechanisms of GC-induced fetal lung maturity remain unclear. Prenatal GC increase fetal TH activity in humans and in animals. Thus, it is possible that increased fetal TH activity after prenatal GC plays a role in accelerating fetal lung maturation. However, this hypothesis has remained untested due to the lack of a suitable animal model. In the hyt/hyt mouse primary hypothyroidism occurs due to a point mutation in the beta subunit of the thyroid-stimulating hormone receptor of the thyroid gland, and it is transmitted in an autosomal recessive manner. We studied the effect of maternal betamethasone on fetal lung ultrastructure in hyt/hyt (hypothyroid) and Balb-c (euthyroid) mice. Hypothyroid mice were made euthyroid by T3 supplementation and mated to carry hypothyroid pups. Vehicle (n = 6) or betamethasone (n = 6) was injected intraperitoneally twice daily into the doe on days 16 and 17 of gestation. Fetal lungs on 18 days of gestation were subjected to ultrastructural morphometric analysis. The number of lamellar bodies per type II cell increased after betamethasone in Balb-c (2.10+/-0.31 vs. 3.43+/-0.37) and hyt/hyt (0.77+/-0.28 vs. 3.85+/-0.26) mice. The alveolar-to-parenchymal ratio was less in the vehicle-treated hyt/hyt (0.082+/-0.024) as compared with the vehicle-treated Balb-c (0.30+/-0.05) mice, while prenatal betamethasone increased the alveolar-to-parenchymal ratio in the hyt/hyt (0.227+/-0.034) but not in the Balb-c (0.26+/-0.04) mice. The glycogen-to-nucleus ratio was higher in betamethasone-treated hyt/hyt mice (1.46+/-0.20) when compared to vehicle-treated hyt/hyt (0.89+/-0.14) or Balb-c (1.01+/-0.17) or betamethasone-treated Balb-c (0.81+/-0.13) mice. Though tubular myelin was readily apparent in the airspace lumen of betamethasone-treated Balb-c mice, it was absent in betamethasone-treated hyt/hyt fetal lungs. We conclude that fetal thyroid plays an important role in accelerating some aspects of fetal lung ultrastructural maturation from GC stimulation.

Operational feasibility and efficacy of deltamethrin impregnated hessian curtains in comparison to HCH indoor residual spraying to control malaria in selected villages of District Ghaziabad (U.P.), India

A study was carried out in selected villages of District Ghaziabad to evaluate the operational feasibility and efficacy of hessian curtains impregnated with deltamethrin@100 mg/m2 in comparison to indoor residual spraying of HCH@0.2 g/m2. The impregnation was carried out before onset of transmission and observations were continued up to two transmission periods. District Health Authorities have carried out HCH indoor residual spraying (IRS) as per schedule in the control village. Entomological evaluation revealed 87 per cent reduction of An. culicifacies up to six months in comparison to HCH indoor residual spraying. However, the reduction in densities of total mosquitoes was only 61.6 per cent. Follow-up studies revealed that the impact of deltamethrin impregnated curtains was diluted after 6-7 months. The results of bioassay tests revealed 100 per cent mortality up to 6-7 months. Epidemiological evaluation revealed 81.9 per cent reduction in total malaria cases as against 88.5 per cent with P. falciparum cases. Similar reduction was also observed when slide positivity rate (SPR), slide falciparum rate (SfR), cases/000 and Pf/000 were compared to corresponding village. Pilot studies are indicated to evaluate the relative efficacy of impregnated curtains, which is quite cheaper than conventional residual insecticide spraying (IRS).

Relative efficacy of insecticide treated mosquito nets (Diptera: Culicidae) under field conditions

The relative efficacy of insecticide treated mosquito nets was evaluated under field conditions in Dehra village of Dhaulana PHC, District Ghaziabad, U.P., India, during 1996. Nylon nets were impregnated with deltamethrin, cyfluthrin, lambdacyhalothrin, and etofenprox at 25 mg/m2 by standard methods. Repellent, excito-repellency, killing, and airborne actions were monitored from dusk to dawn by hourly collection of mosquitoes that entered and rested in rooms and also females that landed on treated and untreated mosquito nets. Results revealed 15.3-22.9% repellent action, 98.3-99.3% excito-repellency action, and 100% mortality of females that landed on treated fabrics. No significant differences were observed in the efficacy of different synthetic pyrethroids against anophelines. However, against Culex quinquefasciatus Say there was a significant difference between deltamethrin and etofenprox. Control of anophelines was more pronounced than Cx. quinquefasciatus. There was no pronounced airborne action with any insecticide tested. Synthetic pyrethroids with strong airborne action may be more appropriate for impregnation of mosquito nets.

Gonadotropin-releasing hormone increases CD4 T-lymphocyte numbers in an animal model of immunodeficiency

BACKGROUND

Gonadotropin-releasing hormone (GnRH) possesses immunostimulatory properties. We have previously demonstrated that GnRH antagonists decrease lymphocyte numbers in an animal model of autoimmune disease. We speculated that the converse might be true, that GnRH administration would increase lymphocyte numbers or alter lymphocyte subsets in an immunodeficiency state.

OBJECTIVE

Our purpose was to test the hypothesis that GnRH agonist would increase IgG and CD4 counts in a rat model of immunodeficiency independently of gonadal steroids.

METHODS

We used diabetes-prone (DP) BB rats. This model has been characterized to have an AIDS-like lymphocyte profile, with lymphopenia and depressed CD4 counts. Ovariectomized female DP rats were randomized to receive subcutaneous injections with GnRH or vehicle 6 times weekly. DR rats were ovariectomized and treated with vehicle as controls. We performed flow cytometric analysis and complete blood cell counts at baseline, 3.5 weeks, and 7 weeks of treatment. We also measured total serum IgG and luteinizing hormone levels.

RESULTS

GnRH administration significantly increased total serum IgG levels in DP rats compared with vehicle. The percentages of CD4(+) cells in blood were also significantly increased in the GnRH-treated group compared with the vehicle-treated group and compared with baseline. Similarly, the absolute numbers of CD4(+) positive T cells were increased over controls at 7 weeks. The effects of GnRH were specific for the CD4 subset because there were no significant differences in numbers of CD8(+) positive cells between the 2 treatment groups.

CONCLUSION

GnRH shows potential utility as an immunostimulatory agent in immunodeficient states manifesting diminished numbers of immunocompetent CD4(+) T lymphocytes.

Gender-specific exacerbation of murine lupus by gonadotropin-releasing hormone: potential role of G alpha(q/11)

We have previously demonstrated that GnRH and its analogues modulate the severity of murine systemic lupus erythematosus. In the present study, we demonstrate that GnRH alters disease severity in a sexually dimorphic fashion, even in gonadectomized mice. GnRH administration leads to an exacerbation of lupus in ovariectomized females, whereas it exerts no effect in castrated males. We initially hypothesized that gender differences in lymphocytic expression of GnRH receptor might explain these observations. Using competitive RT-PCR and binding studies to quantitate GnRH receptor expression in lymphoid organs, we found that GnRH administration led to decreased expression of GnRH receptor messenger RNA (mRNA) and GnRH binding, compared with vehicle, in spleens of ovariectomized females after 2 weeks of treatment. These decreases occurred concurrently with increased expression of interleukin-2 receptor mRNA and protein in females. GnRH administration did not alter GnRH receptor or interleukin-2 receptor mRNA or protein in castrated males. GnRH exerts actions on the pituitary through G protein signal transduction, specifically through G alpha(q/11). Competitive RT-PCR revealed that GnRH administration was associated with increases in the expression of G alpha(q/11) mRNA, compared with vehicle, in spleens in ovariectomized females but not in castrated males. Immunoblot analysis revealed a similar pattern. We conclude that gender differences in expression of G alpha(q/11) may contribute to gender differences in immunity and/or autoimmune disease.

Renal lesions associated with AIDS--an autopsy study

Kidneys from 55 cases (20 with HIV infection and 35 with AIDS) were studied by routine Haematoxylin and Eosin stains and special stains (PAS, PASM GMS, ZN, Mucicarmine and Congo red) to evaluate, glomerular, interstitial and vascular pathology. Twenty-four of the 35 (68.6%) cases of AIDS showed infective aetiology which included 17 cases (48.5%) of tuberculosis, 5 cases (14.4%) of fungal infection (3 cryptococcus neoformans and 2 candida species) and 2 cases (5.7%) of CMV infection. Other lesions noted were amyloidosis and tubular calcinosis. HIV associated nephropathy (HIVAN) was not detected in any of the cases. Intravenous drug abuse was not a risk factor in our cases which probably explains the absence of HIV associated nephropathy in the present study.

Relative efficacy of synthetic pyrethroid-impregnated fabrics against mosquitoes under laboratory conditions

The efficacy of synthetic pyrethroid-impregnated fabrics was evaluated against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus, under laboratory conditions. Results revealed that delta-methrin was significantly superior in comparison to lambdacyhalothrin and cyfluthrin. Results of bioassay tests revealed that deltamethrin was 1.5 and 1.9 times more effective than lambdacyhalothrin and cyfluthrin, respectively, against An. stephensi exposed to cotton fabric treated at 100 g/m2. Deltamethrin was 3.9 and 4.6 times more effective against Ae. aegypti and 3.53 and 4.0 times more effective against Cx. quinquefasciatus. Of cotton, nylon, polyethylene, and jute fabrics, the cotton was the best on the basis of median lethal dose (LD50) and 95% lethal dose (LD90) values and persistence of insecticide.

A longitudinal study of sero-reactivity to Plasmodium falciparum antigen in children and adult living in an endemic area of U.P

Antibody levels of Pf RESA derived peptide R1 (EENVEHDA-C) from individuals living in malaria endemic areas correlated well with levels of endemicity. Serological and parasitological investigations were done in 32 adults (> 20 yrs) and 35 children (2-5 yrs) for three years; i.e. from 1992-95 periodically in village Piyawoli, U.P. Antibody levels against R1 peptide was estimated by ELISA, and blood smear for P. falciparum and P. vivax were screened using Jaswant Singh-Bhattacharya (JSB) staining. It appeared from our investigations that anti-R1 antibodies had a short span of life, i.e. 6-9 months. The longevity of these antibodies do not differ much in adults and children. The studies do not indicate any protective role for these antibodies. However, the levels of anti-R1 antibodies in a population living under malariogenic condition are related to Pf malaria endemicity.

Thyrotropin-releasing hormone accelerates fetal mouse lung ultrastructural maturation via stimulation of extra thyroidal pathway

Maternal administration of TSH-releasing hormone (TRH) in the euthyroid mouse accelerates fetal lung ultrastructural maturation. However, the mechanism(s) of TRH in fetal lung development remains unclear; it could be due to its neuroendocrine and/or neurotransmitter effects. Although the neuroendocrine effect of TRH is mediated via stimulation of the fetal pituitary-thyroid axis, the neurotransmitter effect is mediated via stimulation of fetal autonomic nervous system activity. In the hyt/hyt mouse there is a point mutation in the beta subunit of the TSH receptor in the thyroid gland of the Balb-c mouse. In these mice TSH does not bind to its receptors, leading ultimately to the development of primary hypothyroidism, which is transmitted as an autosomal recessive trait. A maturational delay in the lung ultrastructure of the hyt/hyt mouse fetus has been observed. This investigation was undertaken to study the effect of maternal TRH treatment on lung ultrastructural maturation in the hyt/hyt mouse fetus. If the effect of TRH is mediated via stimulation of fetal pituitary-thyroid axis, TRH treatment should not enhance lung maturity in the hyt/hyt fetus and vice versa. Adult hyt/hyt mice made euthyroid by triiodothyronine supplementation were mated to carry hyt/hyt pups. Saline or TRH (0.4 or 0.6 mg/kg/dose) was administered to the mother (i.p.) on d 16 and 17 (b.i.d.) and on d 18 of pregnancy 1 h before killing (term, approximately 20 d). The fetal lung electron micrographs were subjected to ultrastructural morphometric analysis of the number of lamellar bodies and glycogen/nuclear ratio in type II cells, and the alveolar/parenchymal ratio by Chalkley point counting with an interactive computerized image analyzer (Optimas, Bioscan). Fetal lungs exposed to the lower dose of TRH (n = 7) showed no significant difference in their ultrastructural maturation when compared with saline-treated controls (n = 5). However, fetal lungs exposed to a higher dose of TRH (n = 6) showed increased numbers of lamellar bodies per type II cell, an increase in the alveolar/parenchymal ratio, larger air spaces, thinner alveolar septa, presence of tubular myelin, and increased numbers of air-blood barriers. We conclude that the effect of TRH in accelerating fetal mouse lung maturation is at least in part mediated via stimulation of extra thyroidal pathways.

Residual efficacy of deltamethrin 2.5 wp (K-othrin) sprayed on different types of surfaces against malaria vector Anopheles culicifacies

Residual efficacy of deltamethrin 2.5 wp on various types of surfaces was tested against Anopheles culicifacies under field conditions using WHO standard procedure. Deltamethrin was most effective on the thatched surface and produced 100% mortality of An. culicifacies adults up to 12 weeks, even when exposed at the lowest dose /12.5 mg/m2. It was least effective on brick surface and 100% mortality was observed only for three weeks. The efficacy was observed for 8 and 7 weeks on mud and cement surfaces, respectively. However, at the higher rate of application, i.e. 25 mg/m2, 100% mortality of this species was obtained for 12, 10, 9 and 12 weeks on mud, cement, brick and thatch surfaces, respectively.

High prevalence of chloroquine resistant Plasmodium falciparum infection in Rajasthan epidemic

Plasmodium falciparum is the main killer among all human malaria parasites. In 1994, there was a falciparum malaria epidemic in Rajasthan, India, with many deaths. We have investigated active falciparum malaria cases from this epidemic and found that most of the parasite isolates (95%) were resistant to chloroquine. Nevertheless, all the tested isolates from the epidemic, were sensitive to mefloquine and quinine and ninety percent were also susceptible to sulfadoxine/pyrimethamine. Most individuals had moderate levels of TNF-alpha (20-220 pg/ml) and anti-parasite IgM antibodies compared to IgG levels which were relatively lower. In conclusion, the high transmission rate of the chloroquine resistant P. falciparum parasite could be the probable cause of the disease epidemic in Rajasthan. The timely drug sensitivity test and availability of appropriate antimalarial drugs are, therefore, warranted.

Upper airway obstruction secondary to acinic cell carcinoma of the trachea. Use of Nd:YAG laser

Comprising 1 to 4% of all tumors and 7 to 15% of malignant neoplasms of the major salivary glands, acinic cell carcinoma (ACC) rarely occurs in the respiratory tract. There has been only one case of ACC of the trachea previously reported in the medical literature. A second case of ACC of the trachea associated with upper airway obstruction and its management by Nd: YAG laser and surgical resection is reported.

Study on the feasibility of delineating mosquitogenic conditions in and around Delhi using Indian Remote Sensing Satellite data

A feasibility study to identify mosquitogenic conditions in six study sites in and around Delhi (Bhalaswa lake, Nazafgarh drain, Seelampur lake, Sanjay lake, Okhla barrage and Hindon barrage) using Indian Remote Sensing Satellites was carried out. The water bodies with marshy areas, vegetation and human settlements were considered as environmental variables responsible for mosquitogenic conditions. Multidate IRS 1A and B, LISS-II satellite data were collected and analysed on Vax 11/780 computers. False colour composite (FCC) images were generated and land cover assessed using supervised classification based on ground truth training sets. Ground truth validation of satellite data was done on satellite pass dates. Concurrent monitoring of larval and adult mosquito density was performed by selecting sub-sites in each study site. The results indicate that mosquitogenic conditions can be identified (with limitation of resolution, i.e. 36.5 m) using FCC images and these images can be used as base maps of study sites. Characterization of study sites based on land cover was done from the view point of mosquitogenic conditions. Spatial changes in mosquito density vis-a-vis changes in environmental variables revealed positive correlation with water bodies and vegetation in some study sites.

Major differences in the spectrum of gastrointestinal infections associated with AIDS in India versus the west: an autopsy study

The spectrum of bowel infections in patients with AIDS in India is not well characterized. To examine this spectrum of infections, an autopsy study of 49 subjects was carried out. Multiple sections were obtained from the gastrointestinal tract. A pathogenic organism was detected in 25 (71%) of 35 patients with diarrhea vs. 4 (29%) of 14 patients without diarrhea (P < .01). The most frequent pathogen was cytomegalovirus (in 13; 27%), followed by parasites (9; 18%), fungi (8; 16%) and Mycobacterium tuberculosis (7; 14%). This is the first autopsy study of patients with AIDS in the Indian subcontinent and shows important differences in the profile of their opportunistic infections compared with those of such patients in the West. These findings will help define the optimal diagnostic and therapeutic approaches to patients with AIDS, which, in view of the considerable budgetary restrictions in developing countries, should be targeted toward the pathogens most frequently identified in such areas.

Preliminary evaluation of safety aspects of neem oil in kerosene lamp

Kerosene lamps containing one per cent neem oil were used for mosquito repellent action in a village near Delhi. The safety aspects of this personal protection method developed by Malaria Research Centre were evaluated by animal studies and clinical examination of population before and after exposure. Single application of neem oil (1%) did not produce skin irritation in rabbits and adverse effect on guinea pigs after exposure to aerosol. Clinical examination of 156 adults and 110 children did not reveal any major adverse effects after one year of exposure to 1% neem oil.

Operational feasibility of malaria control by burning neem oil in kerosene lamp in Beel Akbarpur village, District Ghaziabad, India

A field trial in Beel Akbarpur village, Dadri PHC, District Ghaziabad (U.P.) was carried out to test the impact of burning neem oil in kerosene lamp from dusk-to-dawn in living rooms on vector populations and incidence of malaria. Results revealed that burning 1% neem oil in kerosene lamps resulted in the deviation of An. culicifacies from living rooms to cattlesheds. This was also reflected when malaria incidence was compared in experimental and control villages. Cases/000 and Pf/000 were 1.03 and 0.0 in experimental village as against 9.6 and 4.3 in control village. Discontinuation of burning 1% neem oil in kerosene lamp resulted in recurrence of An. culicifacies in living rooms and increase in malaria incidence in experimental village.

Solitary thyroid nodule: a study of 100 cases

One hundred cases of solitary thyroid nodules attending the thyroid clinic, Institute of Postgraduate Medicine & Research, Dhaka (IPGMR) and the Institute of Nuclear Medicine (INM) were included in a prospective study. Thyroid ultrasonography (USG), scintiscanning, radioactive iodine (I131) uptake (RAIU), estimation of serum total T3, T4 & TSH and Fine Needle Aspiration Cytology (FNAC) were performed in all cases. Surgical resection with histopathologic study was performed in selected cases. Extra-nodular part of the thyroid gland was normal in 68 and diffusely enlarged in 32, RAIU was normal in 62, high in 36 and very low in two subjects. Nodules were solid at USG in 67 subjects, cystic in 16 subjects and of mixed consistency in 17 subjects. Goitrous subjects had significantly lower T4 (p < 0.001) and higher T3 (p < 0.01) and TSH (p < 0.001) than non-goitrous ones. Colloid nodule was the commonest pathology occurring in 41 cases, followed by thyroid cysts (26), follicular adenoma (23), adenoma with cystic change (7), subacute thyroiditis (2) and papillary carcinoma (1). Colloid nodules were more common in goitrous subjects which could hint at iodine deficiency as the major cause of such nodules. Hyperfunctioning follicular adenomas occurred exclusively in non-goitrous subjects. Carcinoma appeared to be uncommon in patients with solitary nodules. It gives an opportunity to our physicians to be more conservative in selecting patients with solitary thyroid nodules for surgical treatment.

Relative efficacy of various oils in repelling mosquitoes

Field studies were carried out to determine the relative efficacy of repellant action of vegetable, essential and chemical base oils against vector mosquitoes. Results revealed that essential oils viz. Cymbopogan martinii martinii var. Sofia (palmarosa), Cymbopogan citratus (lemon grass) and Cymbopogan nardus (citronella) oils are as effective as chemical base oil namely mylol. These oils provide almost complete protection against Anopheles culicifacies and other anopheline species. Per cent protection against Culex quinquefasciatus ranged between 95-96%. Camphor (C. camphora) oil also showed repellent action and provided 97.6% protection against An. culicifacies and 80.7% against Cx. quinquefasciatus. Vegetable oils namely mustard (B. compestris) and coconut (C. nucisera) showed repellent action, however the efficacy of these oils was not much pronounced against Cx. quinquefasciatus. Results of statistical analysis revealed significant difference between vegetable and essential oils (p < 0.01) against tested species of mosquitoes. Essential oils were found marginally superior in repellancy than camphor and mylol (p < 0.01) against An. culicifacies and Cx. quinquefasciatus.

Efficacy of two flowable formulations of Bacillus sphaericus against larvae of mosquitoes

Laboratory evaluation revealed that the Spherimos and Vectolex formulations of Bacillus sphaericus produced 97 and 100% larval mortality respectively in Culex quinquefasciatus at a dose as low as 0.008 ml/sq m as against 93 and 97% mortality respectively at 1 ml/sq m in Anopheles stephensi. However, in An. culicifacies similar level of mortality was not observed even at 10 ml/sq m of these formulations. Field evaluation revealed 100% reduction of Cx. quinquefasciatus larvae for 2-3 weeks in pools and wells with single application of Spherimos @ 2 ml/sq m as against 95.4% reduction @ 10 ml/sq m in irrigation channel for one week. Vectolex @ 10 ml/sq m provided 99-100% reduction of Cx. quinquefasciatus larvae up to 9 weeks in wells and 1 week in channels.

Plasmodium vivax: immune responses in a cross-section of the population in the Delhi area of India

The immune status of the individuals living in the Delhi area of northern India where Plasmodium vivax is predominant is described. The majority of the individuals who were acutely infected with P. vivax had antibodies against crude blood-stage antigen and the recombinant antigen, PV9. In contrast, the peripheral blood mononuclear cells of the majority of these individuals did not show proliferation in the presence of either of these antigens. There was no correlation between antibody levels and T cell proliferation. Such an immune status of individuals living in endemic areas should be taken into account in the future in developing P. vivax malaria vaccines.

Repellent action of Cymbopogan martinii martinii Stapf var. sofia oil against mosquitoes

Studies were carried out to evaluate the repellent action of Cymbopogan martinii martinii Stapf var. sofia (F. Gramineae) against mosquitoes under field conditions. Results revealed that the oil has strong repellent action and provided absolute protection for 12 h against Anopheles culicifacies, a principal vector of malaria in the country. Similar degree of protection was evident against An. annularis and An. subpictus. The protection against Culex quinquefasciatus, a pest mosquito was 96.3% for 12 h. Results of evaluation in captivity revealed complete protection against this species for 5 h.

Field trial of esbiothrin-impregnated rope in Ramgarh village, Dadri PHC, District Ghaziabad (U.P.)

A village-scale field trial was carried out to assess the operational feasibility and efficacy of smouldering 250 ppm esbiothrin-impregnated rope in repelling mosquitoes and its impact on transmission of malaria. Entomological monitoring revealed that smoke from smouldering rope resulted in 67.2-97.9% reduction of An. culicifacies densities in human and mixed dwellings. The reduction was obviously due to diversion of An. culicifacies population to cattlesheds where ropes were not burnt. The impact was more pronounced when indoor mosquito landing rate on human bait was compared with that of experimental and control areas. This was also reflected in reduced anthropophilic index and curtailment of malaria transmission in experimental area.

Personal protection from mosquitoes (Diptera: Culicidae) by burning neem oil in kerosene

The repellent action of neem oil (extracted from the seeds of Azadirachta indica A. Juss) was evaluated on mosquitoes at two villages near Delhi, India. Kerosene lamps containing neem oil were burned in the living rooms, and mosquitoes resting walls or attracted to human bait were collected inside rooms from 1800 to 0600 h. Neem oil (0.01-1%) mixed in kerosene reduced biting of human volunteers and catches of mosquitoes resting on walls in the rooms. Protection was more pronounced against Anopheles than against Culex. A 1% neem oil-kerosene mixture may provide economical personal protection from mosquito bites.

Beta-adrenergic modulation of rat brain insulin receptor activity in normal and hyperglycaemic conditions

The [125I]Insulin binding and receptor kinase activity were assessed in rat brain in the presence of 10 microM concentrations of the beta agonist isoproterenol. While insulin binding remained unaltered, beta agonist treatment enhanced significantly receptor kinase activity in control and hyperglycaemic conditions. Antihyperglycaemic effects of isoproterenol were discussed in relation to adrenergic effects on insulin action in brain.

Ageing erythrocytes and alloxan diabetes: I. A possible role of catalase, GSH, GSSG, and GSH-enzymes in decreasing defence system

The erythrocytes from control (C), diabetic (D) and insulin-treated diabetic (D+I) rats were separated into three ageing groups (TAG) i.e., light dense (young cells), intermediate-dense (middle-aged cells) and heavy-dense (old aged cells) samples. The activities of enzymes and metabolites changed from young to old cells in the following manner: (1) Increase of CAT in TAG and a lower level in D and D+I (2) Decrease of GPx in TAG but a low level in D (3) Increase of GR in TAG but a higher level in D, (4) Increase of GST in C and a decrease in D with a higher level in young cells and a lower level in middle-aged and old cells. The reversal of enzyme was more in young cells of D+I (5) Increase of GSH in TAG, a low level in D and a high level in D+I (6) Increase of GSSG in TAG, a high level found only in young cells of D. The results show that young red cells are affected more significantly in diabetes than other age cell types.

Mosquito repellent action of neem (Azadirachta indica) oil

Two percent neem oil mixed in coconut oil, when applied to the exposed body parts of human volunteers, provided complete protection for 12 h from the bites of all anopheline species. Application of neem oil is safe and can be used for protection from malaria in endemic countries.