Use of kerosene lamp containing synthetic pyrethroids to repel mosquitoes

An indigenous and appropriate method of personal protection was developed and tested in rural areas. It consists of an ordinary kerosene lamp made of tin with a regulator to adjust the wick. Different concentrations of esbiothrin, a synthetic pyrethroid, were mixed in kerosene and allowed to burn in living rooms and cattlesheds from dusk to dawn to observe hourly entry of mosquitoes. The tin lamp (100 ml capacity) without chimney provided the most efficient protection from mosquito bites. The protection varied from 84.2 +/- 8.2 to 97.8 +/- 2.8. Maximum protection was observed against An. culicifacies. Esbiothrin kerosene lamp (0.01%) lighted in living room provided 99.7% protection to exposed human baits seated at a distance of 1 m from the lamp. The technique is simple, cost-effective and does not require electricity and can be used both for illumination and repelling mosquitoes in remote and inaccesible areas.

In vitro effect of testosterone propionate on lactate dehydrogenase and malate dehydrogenase in brain and gonads of Channa punctatus

The activities of lactate dehydrogenase (LDH), malate dehydrogenase (MDH), and protein levels were measured in vitro incubation of tissue homogenate of brain and gonads with testosterone propionate (TP) in Channa punctatus (teleost). The activities of LDH and MDH were found to be highest in the ovarian tissues in comparison to the testis and the brain in control fish. TP (2 micrograms-4 micrograms/ml) stimulated testicular tissue with increases in LDH by 10-fold and MDH by 15-fold approximately, the ovary with significant increase in LDH and a decrease in MDH and the brain showed only an increase in MDH.

Esbiothrin-impregnated ropes as mosquito repellent

Esbiothrin [(+/-)-3-allyl-2-methyl-4-oxocylopent-2-enyl-(+)-trans- chrysanthemate] is an improved isomeric composition of allethrin series and consists essentially of esters of chrysanthemic acid and allethrolone. Jute rope was impregnated with esbiothrin and the smoke from smouldering ropes was evaluated as mosquito repellent in human dwellings and cattlesheds with open doors and windows at different dosages. Esbiothrin-impregranted (500 ppm) ropes prevented the entry of more than 95% An. culicifacles and other anophelines, 90.9-88.8% Culex quinquefasciatus and 96-95.1% total mosquitoes in open rooms of houses and cattlesheds respectively. The impact of ropes was more pronounced on the biting rate of mosquitoes. Indoors and outdoors human baits seated at a distance of about 3 m from smouldering esbiothrin ropes experienced no bite at all from An. culicifacies. An iron mesh around the rope prevents fire hazards.

Genetic markers in refractory and susceptible malaria patients in village Bhanera, Distt. Ghaziabad, U.P

Malaria 'susceptible' and 'refractory' subjects from village Bhanera in District Ghaziabad (Uttar Pradesh) were examined for various genetic markers, viz., ABO, haptoglobin, haemoglobin and glucose-6-phosphate dehydrogenase polymorphism. One hundred and nine susceptible and 36 refractory subjects were studied. No significant differences with respect to distribution patterns of the genetic markers were observed in the two groups except for AB blood group. In general, a high incidence of ahaptoglobinaemia was observed in this population and incidence increased with the increase in malaria attacks, suggesting that repeated malaria attacks cause ahaptoglobinaemia.

Role of Azolla in controlling mosquito breeding in Ghaziabad district villages (U.P.)

A survey was carried out during post-monsoon period (1988-89) in villages of Dhaulana Primary Health Centre, Distt. Ghaziabad (U.P.) to evaluate the utility of Azolla pinnata for the control of mosquito breeding in different habitats. Results of the survey revealed that pools, ponds, wells, rice fields and drains were infested with Azolla. Infestation rate and intensity of infestation varied from habitat to habitat. Maximum infestation (36.5%) was observed in pools and minimum (3.7%) in rice fields. Anopheline breeding was almost completely suppressed (0-1.6/dip) in pools, wells and ponds completely covered with Azolla. The breeding of Culex spp. was not completely inhibited in any habitat, though reduction in immature density was observed in comparison to control. The role of Azolla in controlling mosquito breeding and its association with the blue green algae which fixes nitrogen is discussed.

Evaluation of juvenile hormone analogue JHM/S-31183 against immature stages of mosquitoes in natural habitats

A study was carried out to evaluate the potentiality of Juvenile hormone compound JHM/S-31183 against immatures of mosquitoes in natural habitats. Of two formulations tested 1% emulsifiable formulation was marginally superior than the granule formulation. Adult emergence of An. stephensi was completely inhibited upto 12 weeks when 0.5% granule formulation was applied at 0.04 ppm in wells as against 50% inhibition upto 8 weeks in pools. However, in Culex quinquefasciatus the per cent inhibition of adult emergence varied from 52 to 90 per cent. 100% inhibition in pools upto one week at 0.04 ppm in An. stephensi was also obtained with 1% emulsifiable formulation but the effect was diluted in successive weeks. The impact of this formulation was not much pronounced against Culex quinquefasciatus.

Evaluation of certain mosquito repellents marketed in India

A study was carried out in certain villages of Distt. Ghaziabad (U.P.) to evaluate the efficacy of commercially available mosquito repellent preparations and devices. Results revealed that none of the repellents tested provided absolute protection against mosquito bites. The protection varied from 38 to 98% with different species of mosquitoes. In general, better protection was provided against Anopheles bite than against Culex. Of ten repellents evaluated. Mylol oil and Tortoise coils were marginally superior to Odomos cream and Rooster coils. Among electrical devices, Good Bye and Casper were marginally superior to Good Knight and Knight Queen.

Field evaluation of deltamethrin against resistant Anopheles culicifacies in Distt. Ghaziabad (U.P.) India

A field study to evaluate the impact of deltamethrin spraying on DDT and HCH resistant A. culicifacies population was carried out in Razapur primary health centre (PHC), Distt. Ghaziabad (U.P.) India. The PHC comprising of about 0.14 million population was divided into 3 sections of equal size and sprayed with (i) 3 rounds at 12.5 mg/sq m at 6 weeks interval, and (ii) 2 rounds each at 20 mg/sq m and 25 mg/sq m at 8 weeks interval. One section in Dadri PHC located at a distance of about 22 kms was held as control. In this area 3 rounds of HCH were sprayed by the NMEP as was done to control malaria in this district. Deltamethrin spraying was carried out for 3 years. Results revealed that spraying at 12.5, 20 and 25 mg/sq m resulted in drastic reduction of DDT and HCH resistant A. culicifacies population and in the interruption of malaria transmission. In control area high vector densities and malaria transmission was encountered throughout the period of study. Spraying of deltamethrin resulted in build-up of Culex quinquefasciatus population due to resistance.

Atrial natriuretic peptide, arginine vasopressin, aldosterone and plasma renin activity in carbon tetrachloride-induced cirrhosis in rats

The concentrations of atrial natriuretic peptide, arginine vasopressin, aldosterone and the plasma renin activity were studied in male rats with carbon tetrachloride-induced compensated cirrhosis, and the results were compared to those of normal control animals. The rats with cirrhosis exhibited significantly higher plasma renin activity values when compared with the control group. However, plasma concentrations of atrial natriuretic peptide and arginine vasopressin were not significantly different in the two groups. Plasma aldosterone concentrations were significantly higher than those found in the normal control group in approximately 50% of the cirrhotic animals, and were equal to or less than the control values in the rest. This dissociation between plasma renin activity and aldosterone values in some of the cirrhotic animals is interesting and parallels observations made in humans with alcoholic cirrhosis. The results suggest that experimentally induced, apparently compensated cirrhosis may be associated with a perceived decrease in effective circulating volume, and that there is no absolute deficiency of atrial natriuretic peptide in this model of cirrhosis.

Insecticide impregnated ropes as mosquito repellent

Ropes were impregnated with different dosages of deltamethrin and burnt throughout the night in human dwellings and cattlesheds. Smoke from smouldering ropes treated with various dose levels gradually saturated rooms and prevented the entry of mosquitoes. This method provided very good protection from mosquito bites including the principal vector of malaria, A. culicifacies. Results of ropes impregnated with 80 ppm deltamethrin were more consistent than at the lower dosage. The technique is indigenous, cost-effective, simple and appropriate for rural areas and does not require any special skills in its application.

Relationship between beta-endorphin/beta-lipotropin, hyperglycemia, and hyperinsulinemia in obese male Zucker rats

The relationship between beta-endorphin(beta-EP)/beta-lipotropin(beta-LP) and insulin secretion in the basal state and after glucose challenge was studied in obese male Zucker rats and their lean littermates. Baseline plasma beta-EP/beta-LP concentrations were similar in the two groups of animals. Baseline plasma insulin and serum glucose concentrations were significantly higher in the obese animals. Following glucose challenge, the increase in plasma beta-EP/beta-LP concentrations was significantly lower in the obese animals than in their lean littermates. Opioid blockade with naloxone failed to alter the baseline hyperinsulinemia and hyperglycemia seen in the obese animals. The data suggest that the hyperinsulinemia in the obese Zucker rat is not due to endogenous hyperendorphinemia as shown in humans with polycystic ovary syndrome. The obese rats showed dissociation between glucose-stimulated plasma levels of beta-EP/beta-LP and insulin levels which may contribute to the hyperinsulinemia and insulin resistance in these animals.

Evaluation of Bacillus sphaericus to control breeding of malaria vectors

Bacillus sphaericus formulations (Solvay liquid 2362 and Abbott granules 2297) were tested in the laboratory and field for the control of mosquito breeding. Results of laboratory evaluation revealed that both formulations had good larvicidal activity against Culex quinquefasciatus, at 0.04 ml and 1 gm/sq m dosages respectively. Higher dosages at 5 ml liquid or 5 gm/sq m granules were required to control A. stephensi and A. subpictus. A. culicifacies required still higher dosages of Solvay (25 ml/sq m) to achieve same levels of control whereas Abbott granules were not effective even at 20 gm/sq m.

Urinary enzyme output during detoxification of chronic alcoholic patients

The urinary excretion of N-acetylglucosaminidase, gamma-glutamyl transferase and lactate dehydrogenase was elevated by two to three fold in chronic alcoholic patients when compared to normal controls. After 4 weeks of alcohol abstention, the urinary excretion of these enzymes returned to control values. Increased urinary enzyme excretion was not related to malnutrition or pathological glomerular filtration and is due most probably to a direct effect of alcohol on the renal proximal tubule.

Atrial natriuretic peptide, arginine vasopressin, and the renin-angiotensin system in carbon tetrachloride-induced hepatitis in rats

The concentrations of atrial natriuretic peptide (ANP), arginine vasopressin (AVP) and hormones of the renin-angiotensin axis were studied in male rats with carbon tetrachloride-induced hepatitis and the results compared to normal control animals. The rats with hepatitis exhibited lower concentrations of ANP, plasma renin activity (PRA), and angiotensin I (AI) than did the control animals. Plasma concentrations of AVP and aldosterone were not significantly different in the two groups. The results suggest that experimental hepatitis is associated with renal hyperperfusion together with reduction in atrial pressures.

Endogenous opioids and TSH secretion in azotemic male rats

The role of endogenous opioids in the control of thyroid-stimulating hormone (TSH) secretion in uremic male rats was investigated using the narcotic antagonist naloxone. In order to eliminate the effect of weight loss due to uremia-induced anorexia as a cause of altered TSH secretion in uremia, we also studied a group of normal control animals who were pair-fed with the uremic animals, so that their weights were comparable to that of the uremic animals. Naloxone administration produced a significant increase in the basal concentration of TSH response to TRH (5 micrograms i.v.) was significantly blunted in the uremic animals compared to the normal controls and the starved animals. Naloxone administration did not alter the peak thyrotropin-releasing hormone (TRH) stimulated TSH response in any of the experimental groups of rats. Because of the possibility that the effects of naloxone on TSH secretion in the uremic rats were related to impaired clearance of the naloxone in those animals, an additional group of normal rats was given twice the dose of naloxone administered to the uremic animals. The higher dose of naloxone was similarly without effect on the basal or TRH-stimulated TSH secretion in this group. The data suggest that experimental renal failure is associated with diminished sensitivity of the thyrotroph to TRH stimulation and that this blunted sensitivity cannot be abolished by blockade of endogenous opioids by naloxone. Opioid blockade does, however, increase basal TSH secretion in uremic animals, suggesting an increase in endogenous opioidergic tone in uremia.(ABSTRACT TRUNCATED AT 250 WORDS)

Gonadotropin secretion in azotemic male rats--effect of opioid blockade

The role of endogenous opioids in the control of gonadotropin secretion in uremic male rats was investigated using the narcotic antagonist, naloxone. In order to eliminate the effect of weight loss due to uremia-induced anorexia as a cause of previously described altered gonadotropin secretion in uremia, we also studied a group of normal pair-fed control animals who exhibited a weight loss comparable to that of the uremic animals. Naloxone administration had no effect on the basal or LRH-stimulated peak concentrations of LH and FSH in the normal or the uremic rats. Basal and LRH-stimulated gonadotropin responses in the pair-fed rats were comparable to those seen in the normal rats. Similarly, opioid blockade produced no change in the basal or LRH-stimulated gonadotropin responses in the pair-fed animals. Testosterone concentrations were significantly lower in the uremic and pair-fed animals compared to the normal rats. The data suggest that experimental renal failure is not associated with altered opioidergic tone, as it relates to gonadotropin secretion, or to diminished sensitivity of the gonadotroph to LRH stimulation. The decreased testosterone concentration seen in the uremic and pair-fed rats may reflect abnormalities in gonadal hormone secretion due to primary pathology occurring at the level of the gonad. These abnormalities may be reflected as diminished Leydig cell sensitivity to LH. The inappropriately low concentrations of LH in the presence of low testosterone together with normal gonadotropin response to exogenous LRH also suggest an abnormal secretion of endogenous LRH. It is not clear whether this presumed abnormality in LRH secretion is a primary event or is related to decreased testosterone production by the testes in the uremic and pair-fed rats.

Gamma-aminobutyric acid and dysregulation of TSH secretion in uremic male rats

The role of gamma-aminobutyric acid (GABA) in the abnormal secretion of thyrotropic hormone (TSH) in uremia was studied in male Sprague-Dawley rats rendered renally insufficient by subtotal nephrectomy. Baseline TSH concentrations in normal control animals and in the uremic animals were similar. The peak TSH response to thyrotropin-releasing hormone (TRH; 5 micrograms i.v.) was significantly blunted in the uremic animals compared to the controls. Pretreatment of the uremic animals with the specific GABA antagonist, bicuculline (1.5 mumol i.v.) resulted in normalization of the peak TSH response to TRH. Bicuculline pretreatment, however, did not alter the basal secretion of TSH in either the normal or the uremic animals, and it also did not augment the TRH-stimulated TSH response in the normal animals. Sham-operated animals demonstrated basal and TRH-stimulated TSH responses comparable to the control group. In order to assess whether the weight loss associated with uremia could have accounted for the blunted TRH-stimulated TSH secretion in the uremic animals, a group of rats were starved so that their weights were comparable to those of the uremic animals. Basal and TRH-stimulated TSH responses in this group were not significantly different from the controls. Bicuculline pretreatment of the starved animals also failed to alter the basal and TRH-stimulated TSH responses. These data indicate that an increase in central gabaergic tone may be partly responsible for the blunted TSH response to TRH seen in uremia, but that GABA is not an important modulator of TSH secretion in the normal rat.

Dopamine and TSH secretion in uremic male rats

The role of dopamine in the dysregulation of TSH secretion in uremic male rats was investigated using the dopamine antagonist, pimozide. In order to obviate the effect of weight loss due to uremia-induced anorexia as a cause of altered TSH secretion in uremia, we also studied a group of normal animals whose food intake was restricted and who demonstrated weight loss comparable to that of the uremic animals. Baseline TSH concentrations were not significantly different in the normal, uremic or starved animals. Pimozide administration produced no change in the baseline TSH concentrations in any of the groups of rats. The peak TSH response to TRH (5 micrograms IV) was significantly blunted in the uremic animals compared to the normal controls and the starved animals. Pimozide administration did not alter the peak TRH-stimulated TSH response in either the normal animals or the starved animals. However, the peak TRH-stimulated TSH response was significantly increased in the uremic animals and was comparable to the peak TSH response seen in the pimozide-untreated control animals. The data suggest that experimental renal failure in rats is associated with diminished sensitivity of the thyrotroph to TRH stimulation, and that this blunted sensitivity may be dopamine-dependent since it can be abolished by pharmacologic dopamine blockade.