The breeding structure for the small ruminant resources in India.

Intense selection for a few desired traits has resulted in reduction of the effective population size (Ne) in most of the plant and livestock populations across the world. The objective of the research was to assess the impact of Ne on the genetic architecture of the population in a simulated data with variable Ne for general population under selection. Along with this, the estimate of Ne and its ratio to adult breeding population (NB) in the census data of small ruminants of India were also investigated. Results indicated that the average inbreeding ([Formula: see text]) decreases with increase in Ne; similarly, increase in [Formula: see text] per generation was highest in population with lowest Ne. Correlation of estimated breeding value (EBV) with true breeding value (TBV) was not much affected with effective population size. An effective number of chromosome segments (Me) in the populations under selection were significantly affected by magnitude of Ne, with linear positive relation between Ne and Me. Results on livestock census data revealed that all the sheep and goat breeds have sufficiently large Ne based on derived and actual census data. The median for ratio of effective population size to adult census size in sheep breeds was 0.120 and for goat breeds was 0.131. Karnah and Poonchi sheep shares the status of endangered breeds due to a smaller number of breeding female population and hence need attention for conservation. The Ne was large in sheep and goat due to less selection pressure as a result of low coverage of breed improvement programs, availability of large number of breeding males, and absence of artificial insemination (AI) in the field flocks. The estimates of Ne and its ratio to the adult census size (NB) excluded several factors such as fluctuating population size and overlapping generations. Study revealed introspection from most of the industrial breeding programs on the issue of Ne for populations under selection. Similarly, in small ruminants, large Ne indicates huge genetic diversity and scope of improvement in the productivity in near future.

Laser induced fluorescence of biochemical for UV LIDAR application.

Laser induced fluorescence spectroscopy in the ultraviolet regime has been used for the detection of biochemical through a fiber coupled CCD detector from a distance of 2 m. The effect of concentration and laser excitation energy on the fluorescence spectra of nicotinamide adenine dinucleotide (NADH) has been investigated. The signature fluorescence peak of NADH was centred about 460 nm. At lower concentration Raman peak centred at 405 nm was also observed. The origin of this peak has been discussed. Detection limit with the proposed set up is found to be 1 ppm.

Virulence Characterization of International Collections of the Wheat Stripe Rust Pathogen, Puccinia striiformis f. sp. tritici.

Wheat stripe rust (yellow rust [Yr]), caused by Puccinia striiformis f. sp. tritici, is an economically important disease of wheat worldwide. Virulence information on P. striiformis f. sp. tritici populations is important to implement effective disease control with resistant cultivars. In total, 235 P. striiformis f. sp. tritici isolates from Algeria, Australia, Canada, Chile, China, Hungary, Kenya, Nepal, Pakistan, Russia, Spain, Turkey, and Uzbekistan were tested on 20 single Yr-gene lines and the 20 wheat genotypes that are used to differentiate P. striiformis f. sp. tritici races in the United States. The 235 isolates were identified as 129 virulence patterns on the single-gene lines and 169 virulence patterns on the U.S. differentials. Virulences to YrA, Yr2, Yr6, Yr7, Yr8, Yr9, Yr17, Yr25, YrUkn, Yr28, Yr31, YrExp2, Lemhi (Yr21), Paha (YrPa1, YrPa2, YrPa3), Druchamp (Yr3a, YrD, YrDru), Produra (YrPr1, YrPr2), Stephens (Yr3a, YrS, YrSte), Lee (Yr7, Yr22, Yr23), Fielder (Yr6, Yr20), Tyee (YrTye), Tres (YrTr1, YrTr2), Express (YrExp1, YrExp2), Clement (Yr9, YrCle), and Compair (Yr8, Yr19) were detected in all countries. At least 80% of the isolates were virulent on YrA, Yr2, Yr6, Yr7, Yr8, Yr17, YrUkn, Yr31, YrExp2, Yr21, Stephens (Yr3a, YrS, YrSte), Lee (Yr7, Yr22, Yr23), and Fielder (Yr6, Yr20). Virulences to Yr1, Yr9, Yr25, Yr27, Yr28, Heines VII (Yr2, YrHVII), Paha (YrPa1, YrPa2, YrPa3), Druchamp (Yr3a, YrD, YrDru), Produra (YrPr1, YrPr2), Yamhill (Yr2, Yr4a, YrYam), Tyee (YrTye), Tres (YrTr1, YrTr2), Hyak (Yr17, YrTye), Express (YrExp1, YrExp2), Clement (Yr9, YrCle), and Compair (Yr8, Yr19) were moderately frequent (>20 to <80%). Virulence to Yr10, Yr24, Yr32, YrSP, and Moro (Yr10, YrMor) was low (≤20%). Virulence to Moro was absent in Algeria, Australia, Canada, Kenya, Russia, Spain, Turkey, and China, but 5% of the Chinese isolates were virulent to Yr10. None of the isolates from Algeria, Canada, China, Kenya, Russia, and Spain was virulent to Yr24; none of the isolates from Algeria, Australia, Canada, Nepal, Russia, and Spain was virulent to Yr32; none of the isolates from Australia, Canada, Chile, Hungary, Kenya, Kenya, Nepal, Pakistan, Russia, and Spain was virulent to YrSP; and none of the isolates from any country was virulent to Yr5 and Yr15. Although the frequencies of virulence factors were different, most of the P. striiformis f. sp. tritici isolates from these countries shared common virulence factors. The virulences and their frequencies and distributions should be useful in breeding stripe-rust-resistant wheat cultivars and understanding the pathogen migration and evolution.

Studies on the Cl + C2H5I reaction; site specific abstraction reactions and thermodynamics of adduct formation studied by observation of HCL product.

The reaction of chlorine atoms with alkyl iodides can play a role in the chemistry of the marine boundary layer. Previous studies have shown that at room temperature the reaction takes place via a complex mechanism including adduct formation. For the Cl + ethyl iodide reaction results on the thermodynamics of adduct formation and on the product yields are inconsistent. The kinetics of the reaction Cl + C(2)H(5)I have been studied by the direct observation of the HCl product in real time flash photolysis/IR absorption experiments as a function of temperature from 273 to 450 K. At temperatures above 375 K kinetic measurements confirm a direct process and the rate coefficient determined (4.85 +/- 0.55) x 10(-11) exp((-363 +/- 51)/T) cm(3) molecule(-1) s(-1) is in good agreement with previous direct determinations. Product yield studies have also been undertaken by comparing the HCl signal from Cl + C(2)H(5)I with that from a calibration reaction which shows that HCl is the sole product of the reaction at these temperatures. Yield studies with selectively deuterated ethyl iodide demonstrate that abstraction occurs predominantly from the alpha site, with the selectivity decreasing with temperature. Extrapolation of the yield data to 298 K predicts an alpha:beta ratio of 0.68:0.32. At temperatures between 273 and 325 K a biexponential growth was observed for the HCl signal consistent with adduct formation. Analysis of the HCl time profiles allowed the extractions of the forward and reverse rate coefficients for adduct formation and hence the calculations of the thermodynamic properties of adduct formation. A third law analysis yields a value of Delta(r)H = (-54 +/- 4) kJ mol(-1). The value of Delta(r)H is in good agreement with a previous third law determination (J. J. Orlando, C. A. Piety, J. M. Nicovich, M. L. McKee, P. H. Wine, J. Phys. Chem. A, 2005, 109, 6659).

Major Gene Controls of Field Resistance to Spot Blotch in Wheat Genotypes 'Milan/Shanghai #7' and 'Chirya.3'.

A number of exotic wheat (Triticum aestivum) genotypes resistant to spot blotch caused by Cochliobolus sativus are being used to improve the resistance of commercial cultivars in the warm regions of South Asia. The objective of the present study was to determine the inheritance of field resistance to spot blotch in two resistant (R) wheat genotypes, 'Chirya.3' and 'Milan/Shanghai #7' (MS#7), which were crossed to a susceptible (S) commercial cultivar, 'BL1473.' The two resistant genotypes also were crossed to determine allelic relationships for resistance between them. Spot blotch severity was recorded on the parents and on F1, F2, and F3 progenies. The F1 plants from the two crosses between susceptible and resistant genotypes had low disease severity like the resistant parents, indicating that resistance in Chirya.3 and MS#7 is conditioned by dominant gene action. The F2 plants segregated in 3R:1S ratios, and the F2:3 families showed the ratio of 1R:1S:2S, segregating for R and S, suggesting that resistance in the two resistant parents is conditioned by a single, dominant gene. The F1 plants from the cross between the two resistant genotypes were resistant, whereas their F2 progenies segregated in 15R:1S, suggesting that the resistance genes in MS#7 and Chirya.3 are nonallelic. These simply inherited sources of resistance could be useful for improving spot blotch resistance in the warm regions of South Asia and also may offer useful diversity to breeding programs for developing spot-blotch-resistant wheat cultivars in other regions.

Sociocultural factors and malaria in the desert part of Rajasthan, India.

BACKGROUND & OBJECTIVES: Malaria is a new emerging problem of Indian Thar Desert. The study was attempted to find out some sociocultural factors associated with malaria transmission in this region and to supplement social solutions to ongoing malaria control efforts in the desert part of Rajasthan. METHODS: Interview technique was used for data collection on pre-tested schedules. In all 30 households (15 from low socioeconomic group and the same number of households from the high socioeconomic group) in a village were selected following systematic random sampling technique. A total of 450 respondents were selected randomly in 15 villages of Jaisalmer district, Rajasthan. RESULTS: One-third of the respondents had neither taken treatment for malaria nor took part in the vector control operations because they did not consider mosquito bites to be harmful and took malaria as a mild disease. Outdoor sleeping habits, sharing bed with children, uneasy and suffocation feeling in using mosquito bednets or any other protective device also contributed to the spread of malaria in the study villages. INTERPRETATION & CONCLUSION: Community should be educated as a whole particularly the low socioeconomic group of people to bring changes in their beliefs, sociocultural and health practices to protect themselves from mosquito bites by using bednets, repellents and other devices, such as wire mesh screening of house doors and windows.

Treatment seeking behaviour of malaria patients in desert part of Rajasthan, India.

Malaria remains to be the most important cause of morbidity and mortality in India and in many other tropical countries with approximately 2 to 3 million new cases arising every year. In spite of arid conditions prevailing in desert part of Rajasthan, malaria is a major public health problem. A longitudinal study on social determinants of malaria has been undertaken in different villages of Ramgarh PHC of Jaisalmer district, Rajasthan. The study aims to know treatment seeking behabiour of malaria patients in the desert communities which is significantly different than the non-desert part of India. Out of 60 villages, 12 villages and 573 malaria patients were selected randomly. Interview technique was used for data collection. Information was recorded on pre-tested schedules. Self diagnosis 423 (73.8%) was more common among the respondents and 443 (77.3%) had taken treatment at home with local herbal remedies as the first treatment action. Desert population was not used to laboratory test for the malaria diagnosis. Symptoms based treatment was practised. They used private and government health facilities for the treatment of malaria. Self diagnosis for malaria was common but practised more by the poorer households. A large part of the population did not complete the full course of malaria treatment as a result drug resistance was more common. They did not use the government health facility as a first step of malaria treatment. There is need for health education with campaign emphasizing the role of mosquitoes in malaria transmission and the need for prompt medical intervention. The use of Government health services for the diagnosis and treatment of malaria by the poor should be encouraged through appropriate information, education and communication (IEC) which on the long run will be more cost effective for desert population under the national malaria control programme.

Xanthelasma Palpebrarum-clinical and biochemical profile in a tertiary care hospital of Delhi.

Xanthelasma Palpebrarum is the most common of the xanthomas with asymptomatic, symmetrical, bilateral, soft, yellow, velvety, polygonal papules around the eyelids. Xanthelasmas may be associated with hyperlipidemia. This prospective study included 66 clinically diagnosed patients with Xanthelasma Palpebrarum and 50 controls with non-inflammatory skin disorders. Serum triglyceride, cholesterol, HDL, LDL and VLDL estimated in all cases indicated that patients with Xanthelasma Palpebrarum have underlying lipid abnormalities.

Importance of socioeconomic status and tree holes in distribution of Aedes mosquitoes (Diptera: Culicidae) in Jodhpur, Rajasthan, India.

Immature Aedes mosquitoes were found in domestic, peridomestic, and tree hole habitats within three socioeconomic strata of Jodhpur, a city within an arid area of Rajasthan, India, endemic for dengue. Peridomestic habitats served as a persistent source of Aedes vectors, especially those used for watering cows for religious reasons that were located within high socioeconomic areas. Domestic (indoor) containers within low socioeconomic strata showed a higher container index (27.0%) than periurban areas with cattle sheds (14.3%) or high socioeconomic areas (18.1%). Mosquitoes were collected in tree holes at zoos and gardens supporting several species of monkeys. Six of 67 Aedes albopictus Skuse reared from immatures collected in tree holes tested positive for dengue antigen acquired through vertical transmission, possibly indicating a persistence mechanism for dengue virus within an urban environment.

Enhancement of the frequency of methotrexate resistance by gamma-radiation in Chinese hamster ovary and mouse 3T6 cells.

We have studied the effects of gamma-radiation on the frequency of methotrexate resistance and dihydrofolate reductase gene amplification. gamma-Irradiation of Chinese hamster ovary cells resulted in enhancement of the frequency of methotrexate resistant colonies (maximum enhancement: 2000-fold after 1000 rads). The enhancement of methotrexate resistance was dependent on the dose of gamma-radiation and increased with time after irradiation; a maximum enhancement was observed when methotrexate was added 18 h after irradiation. Methotrexate resistant clones of Chinese hamster ovary cells showed no increase in dihydrofolate reductase gene copy number but were found to be defective in methotrexate transport. However, when these experiments were extended to 3T6 murine cells, 54% of nonirradiated and 44% of gamma-radiation induced methotrexate resistant clones showed an increase in dihydrofolate reductase gene copy number. These results suggest that the cells that survive irradiation have a very high probability of becoming methotrexate resistant and may explain why some malignant tumors (e.g., head and neck cancer) either do not respond or respond poorly to chemotherapy if the patient had prior radiotherapy.

A phenotype conferring selective resistance to lipophilic antifolates in Chinese hamster ovary cells.

Trimetrexate, a lipid-soluble analogue of methotrexate, appears to enter mammalian cells by passive diffusion, thus circumventing the methotrexate transport system which is frequently a subject for alterations leading to methotrexate resistance. Using a single-step selection protocol with trimetrexate, we have isolated 45 clonal variants and found the majority of them to be selectively resistant to lipophilic antifolates while retaining their sensitivity to methotrexate and drugs involved in multidrug resistance. The majority of spontaneously induced trimetrexate-resistant clones showed a change in neither the mRNA levels of dihydrofolate reductase (24 of 30) and P-glycoprotein (26 of 30) nor their gene copy numbers, whereas a small fraction of clones (4 of 30) showed multidrug resistance gene amplification and P-glycoprotein mRNA overexpression. gamma-Irradiation prior to selection markedly enhanced the frequency of trimetrexate resistance (100-fold after 1000 rads). None of the gamma-ray-induced trimetrexate-resistant clones (0 of 15) had evidence of dihydrofolate reductase and multidrug resistance gene amplification and/or overexpression. Flow cytometry data on trimetrexate-resistant clones showed no defect in the transport of trimetrexate. Verapamil, a modulator of the multidrug resistance phenotype, had no cytotoxic effect on parental and trimetrexate-resistant clones. However, when present with trimetrexate, verapamil (0.3-0.6 microM) reversed the lipophilic antifolate-resistant phenotype in clones that had invariant levels of P-glycoprotein and dihydrofolate reductase. This selective resistance to lipid-soluble antifolates was initially unstable but became stable after continued drug-selective growth. Two-dimensional gel electrophoresis showed some differences in protein(s) that may potentially be associated with this phenotype of selective resistance to lipophilic antifolates. We conclude that a gamma-radiation-enhanceable, verapamil-reversible, stable phenotype of selective resistance to lipid-soluble antifolates frequently emerges which requires neither the amplification nor the overexpression of dihydrofolate reductase or multidrug resistance genes.

Heterogeneity in the mitotic checkpoint control of BALB/3T3 cells and a correlation with gene amplification propensity.

Chinese hamster ovary (and many rodent cell lines) transiently delay mitosis and progress into a second cell cycle without undergoing cytokinesis when treated with Colcemid, whereas HeLaS3 (and most human cell lines) arrest permanently in mitosis. We have discussed these differences and their consequences for cell survival under cell cycle-perturbing conditions within the context of mitotic checkpoint control (Schimke et al., Cold Spring Harbor Symp. Quant. Biol., 56: 417-425, 1991). Here, we report studies with mouse BALB/3T3 cell populations which, by the criterion of response to Colcemid, constitute a heterogeneous population with respect to mitotic checkpoint control. Clonal and subclonal populations retain population heterogeneity but with a bias for enrichment of cell populations that respond as do HeLaS3 cells. We have analyzed clones for their propensity for gene amplification as assessed by a stepwise increment selection protocol in methotrexate and report that there are significant differences in amplification propensities that correlate with differences in mitotic checkpoint control properties.

Epidemiology of foliar blights (spot blotch and tan spot) of wheat in the plains bordering the himalayas.

ABSTRACT Helminthosporium leaf blight (HLB), a complex of spot blotch caused by Cochliobolus sativus and of tan spot caused by Pyrenophora tritici-repentis, is a major wheat disease in South Asia. This 2-year study elucidated HLB development and its impact on yield. Symptoms caused by C. sativus and P. tritici-repentis were first observed at the seedling and tillering stages, respectively. The number of airborne conidia and leaves infected by the two pathogens remained low for several weeks under lower temperatures, followed by a sharp rise as temperatures increased. The number of airborne conidia of C. sativus and incidence of infection by C. sativus were higher compared with P. tritici-repentis. The disease complex caused an average 30% reduction in yield, with greater losses under delayed seeding. Delayed seeding increased disease severity even in resistant genotypes and caused higher yield losses. 'Milan/Shanghai-7' was the most resistant among six genotypes evaluated. Despite higher disease severity, 'BL 1473' showed relatively lower yield losses, indicating its tolerance to foliar blight. The findings of this study bear implications for integrated foliar blight management in the warmer areas of South Asia by combining optimum seeding date, seed treatment and foliar spray of fungicides, and resistant wheat genotypes.

Study of social determinants of malaria in desert part of Rajasthan, India.

BACKGROUND & OBJECTIVES: A longitudinal study on social determinants of malaria has been undertaken in different villages of Ramgarh PHC of Jaisalmer district, Rajasthan. The study aims to determine social determinants of malaria as applicable to existing cast groups of desert part of Rajasthan. METHODS: Out of 940 households in five villages, 150 households of Rajput community (forward community) and Meghwal community (backward community) were selected at random to study whether due to different behaviour of existing caste groups, transmission of malaria and its intensity also vary or not. RESULTS: It was found that magnitude of malaria was three times more in the Meghwal community as compared to Rajput community. In-migration of natives importing malaria was found to be prominent cause of more malaria incidence in the backward community. INTERPRETATION & CONCLUSION: An intervention policy aiming to study existing status of knowledge among different caste groups of desert areas could lead to a substantial control over in-migration as well as further transmission of disease in the desert part of Rajasthan.

Entomological studies on malaria in irrigated and non-irrigated areas of Thar desert, Rajasthan, India.

BACKGROUND & OBJECTIVES: Malaria is the major health problem in western Rajasthan yet its vector fauna and transmission dynamics thereof is not understood properly. The present investigations report complete profile of qualitative and quantitative aspects of anopheline species occurring in different settings of desert ecosystem. METHODS: Area with irrigation through canal for more than 20 years (setting I), area with irrigation through canal for 10 years (setting II) and area without any irrigation (setting III) have been selected for studies. Species identification and their densities (per man hour) was made as per standard methods. RESULTS: In village of setting I, during rainy season, An. subpictus and An. stephensi were present while during winter season four species--An. subpictus, An. stephensi, An. culicifacies and An. annularis were collected. In all the villages of setting I, II and III no Anopheles mosquito was observed during summer season. In the villages of desert region without any irrigation facilities through any canal, the anopheline species were present only during rainy season. INTERPRETATION & CONCLUSION: An. stephensi is the major malaria vector of desert irrespective of whether the area is canal irrigated or not. During summer season absence of vector species in all the villages require further studies on micro-ecology of the species under desert conditions.

Relationship of arterial wall uptake of radiolabeled liposomes to the presence of monocyte/macrophage cells in the hypertensive and atherosclerotic arterial wall.

In vivo radiolabeled liposome uptake in 5 sham-operated, 7 coarctation-induced hypertensive, and 8 atherosclerotic arterial walls from New Zealand White rabbits was compared to determine the mechanism of arterial wall uptake of liposomes. Uptake between the three groups was significantly different (P less than 0.001) with a 3-fold difference in uptake between the sham-operated and hypertensive groups and the hypertensive and atherosclerotic groups. Liposome uptake was significantly higher in the atherosclerotic group of animals (P less than 0.05). Avidin-biotin immunoperoxidase staining for monocyte/macrophage cells revealed that liposome uptake increased concomitantly with arterial wall monocyte/macrophage cellular invasion and that liposome localization, determined by autoradiography, paralleled the monocyte/macrophage cellular distribution in both hypertensive and atherosclerotic arterial walls. This study provides the first direct evidence that liposomes can escape from the circulation and enter the diseased arterial wall. Furthermore, it suggests that one possible mechanism of arterial wall uptake of liposomes is via the monocyte/macrophage cell which avidly and preferentially engulfs liposomes and then passively carries them into the arterial wall during hypertensive and atherosclerotic lesion development. Liposomes could potentially be used to carry agents into the arterial wall in the study of arterial wall lesion development.

An epidemiological study of 177 cases of human rabies.

Of the 177 rabies patients admitted to various hospitals in Amritsar city, 80.8% were males and 31.1% were children under the age of 15 years. Incidence was found to be gradually increasing in urban areas, although 68.2% were still found in rural areas. History of second or third degree bites existed in all the cases. Dogs were the source of exposure in 97.3% of cases and they were all suspected of having rabies. 49.1% of cases had bites on the lower extremities and 70.8% were on uncovered parts of the body. The incubation period was observed to be between 30 and 120 days in 61.8% of cases; 90.0% of the patients developed the disease within six months of exposure. Short incubation periods were observed in a majority of the patients bitten on more than one part of the body, head, neck and face or bitten on uncovered parts. Hydrophobia and death occurred in 100% of cases and 93.4% of patients died within five days. Post-exposure injections were reported in 10.2% of cases and these showed no definite incubation period pattern.

Probucol suppresses oxidant stress in hypertensive arteries. Immunohistochemical evidence.

Oxy-free radicals may be involved in the pathogenesis of accelerated atherosclerosis in hypertension. We evaluated the direct antioxidant potential of probucol in hypertensive arteries by studying the spatial immunohistochemical distribution of three primary antioxidant enzymes (AEs). Nineteen normocholesterolemic New Zealand White rabbits were divided into two groups: normotensive controls (NT; n = 6) and 13 animals rendered hypertensive by surgical coarctation of abdominal aorta. The hypertensive group was subdivided into hypertensive alone (HT; n = 8) and hypertensive treated with 1% probucol (PO) for 9 weeks (HT-P; n = 5). Blood pressure rose significantly in both hypertensive groups (P < .005). At autopsy, both hypertensive groups showed similarly significant increases in mean arterial intima-media thickness (IMT) whether or not they were treated with probucol. However, only HT rabbits revealed significant increases in the intima-media depth penetration of glutathione peroxidase, superoxide dismutase, and catalase AEs. By contrast, in HT-P animals probucol produced significant reductions of immunostaining of all three AEs compared to the HT group (P < .05). Additionally, specific macrophage immunostaining revealed that the arterial wall of HT rabbits had numerous (10 to 12 per high power field) subintimal and medial macrophages as compared to the HT-P animals (1 to 2 per high power field). The blood pressure level correlated significantly with IMT in all three groups, but with depth penetration of the three AEs only in the NT and HT groups. Probucol, therefore, appears to act in concert with the native arterial antioxidant enzymes as a potent free radical scavenger to reduce oxidative stress and thus attenuate the macrophage invasive response in hypertensive arteries.

Persistence of dengue-3 virus through transovarial transmission passage in successive generations of Aedes aegypti mosquitoes.

Progeny of Aedes aegypti mosquitoes infected intrathoracically with dengue-3 virus was reared to subsequent generations. In each generation, blood-fed females were confined individually and the eggs obtained from the transovarially infected females were pooled. The seventh generation obtained from the infected parental mosquitoes showed that virus could persist in mosquitoes in successive generations through transovarial passage. The rate of vertical transmission initially increased in the few generations (F1-F2), but in subsequent generations it was found to be steady. Parental mosquitoes inoculated with virus showed higher mortality than the diluent-inoculated controls. There was an increase in the larval duration of transovarially infected batches at the seventh generation when compared with uninfected control mosquitoes. The fecundity and fertility of the transovarially infected batches of mosquitoes was also affected when compared with the controls. This is the first report demonstrating persistence of dengue virus in the successive generations of mosquitoes infected through vertical transmission. These observations, which have great epidemiologic importance, suggest that vector mosquitoes may play an important role in the maintenance of virus in nature, and that mosquitoes may act as reservoirs of these viruses.

Limits of lipid-lowering therapy: the benefits of amlodipine as an anti-atherosclerotic agent.

Treatment of atherosclerosis has mainly focused on decreasing low-density lipoprotein cholesterol (LDL-C). However, recent coronary angiographic trials revealed that aggressive lowering of LDL-C below 100 mg/dl arrests atherosclerosis progression in only 50-60% of patients. Furthermore, quantitative coronary angiography in these trials showed significant regression only in advanced fibrous-fatty plaques (> or = 50% stenosis) and not in the younger, more cell-proliferative lesions (< 50% stenosis). It is clear that lipid-lowering therapy has limited efficacy and there is therefore a need for other drugs, especially anti-proliferative agents, for secondary and primary prevention. To test this hypothesis, a new calcium antagonist, amlodipine, was studied for its anti-atherogenicity in non-human primates because of its known in vitro anti-cell proliferant, cell membrane stabilising and anti-oxidant properties. Amlodipine was found to normalise elevated plasma levels of oxidised LDL without reducing elevated total LDL-C levels in monkeys fed an atherogenic diet which, however, significantly suppressed atherosclerosis progression. These data suggest that amlodipine may be an excellent candidate, in combination with lipid-lowering drugs, for dual therapy of atherosclerotic vascular disease and may also be effective as monotherapy even when LDL-C is not lowered satisfactorily.