Larvicidal activity of Artemisia annua L. callus culture against Anopheles stephensi larvae.

The emergence of resistance by both Plasmodium falciparum and Anopheles stephensi made the search for an alternative environmentally safe plant based insecticide inevitable. Artemisia annua is a well known antimalarial. Present study is an attempt to induce callus production from young leaves of Artemisia annua plant and study its larvicidal activity against larvae of Anopheles stephensi. Callus was initiated by using different concentrations of auxins and cytokinins. A suitable culture media was standardized for optimal growth of callus. Healthy callus cultures were obtained in the slightly modified Murashige and Skoog's medium +NAA and BAP (0.03 and 0.2 mg l(-1) respectively) + Sucrose 20 gm l(-1) +Agar 8 gm l(-1) within 28 days of inoculation. Callus was successively extracted in order of increasing polarity of solvents. Larvicidal activity, in terms of lethal concentration (LC50) of the callus extract in chloroform was calculated to be 18.45 +/- 0.75 ppm after72 hr against third instar larvae of A. stephensi.

Larvicidal activity of an indigenous plant, Centratherum anthelminticum.

Crude extracts of fruits and leaves of Centratherum anthelminticum in different solvents were tested for larvicidal activity against Anopheles stephensi, the vector of malaria. The petroleum ether crude extract of both fruits and leaves exhibited significant larvicidal activity against III instar larvae with LC50 values of 162.60 ppm and 522.94 ppm, respectively after 24 hr. The petroleum ether extract of fruit was 11.66, 2.15 and 1.32 times more toxic than that of leaf extract after 24, 48 and 72 hr, respectively at LC90 level. However at LC50 level the corresponding values were 3.22, 1.83 and 1.19, respectively. The petroleum ether extract of C. anthelminticum fruits is a promising source for the control of Anopheles larvae.

Effective method for extraction of larvicidal component from leaves of Azadirachta indica and Artemisia annua Linn.

Leaves of Artemisia annua linn. and Azadirachta indica were extracted in petroleum ether and hexane respectively by different methods of extraction i.e. cold extraction, reflux extraction and soxhlet extraction. The crude extract obtained was tested against third instar larvae of Anopheles stephensi. On comparison of larval mortality of crude extract obtained by these three methods, both soxhlet and reflux extraction method showed 100% mortality at 200 ppm after 48 hr in case of A. annua. However LC50 (20 ppm) value of crude extract obtained by soxhlet extraction showed better results than reflux extraction (35 ppm) method after 72 hr. In case of A. indica, crude obtained by soxhlet showed 100% mortality (after 48 hr) at 250 ppm and LC50 of 69 ppm at 72 hr. Reflux extraction does not show any appreciable mortality even at 250 ppm concentration.

Field measurements of aerosol particle dry deposition on tropical foliage at an urban site.

This paper presents dry deposition of major ions on tropical foliage (leaves of Ashok (Polyalthia longifolia) and Cassia (Cassia siamea)) at St. John's, Agra, an urban site of tropical India on nonrainy, nondewy, and nonfoggy days. The deposition flux was higher on Cassia leaf than Ashok leaf probably due to a rougher surface as shown by scanning electron microscopy. Dry deposition of cations varies from 0.46 to 12.16 mg m(-2) day(-1) while anions vary from 0.04 to 3.24 mg m(-2) day(-1). The percentage contribution of alkaline components is greater than that of acidic components, indicating the alkaline nature of dry deposition. Two-way analysis of variance results reveal significant seasonal variation only for K+, SO4(2-), and F-; however, values varied season to season for Na+, Ca2+, Mg2+, Cl-, NO3-, and NH4+ also. The large seasonal variation in deposition flux may be due to meteorological conditions, diameter of particles, and variation in atmospheric level. SO42- and NO3- show significant correlation, indicating their origin from similar sources while significant correlation between Ca2+ and Mg2+ implies their origin from soil. Poor correlation between Ca2+ and SO4(2-), Ca2+ and NO3-, and Mg2+ and SO4(2-) indicates that in addition to soil other sources also contribute to dry deposition. Low dry deposition fluxes of SO2- and NO3- compared to Ca2+ and Mg2+ may be due to low mass medium diameters of SO4(2-) and NO3- and may be due to uptake through the stomatal pores abundant on leaf surfaces. Factor analysis was employed to identify the sources. F-, Cl, SO4(2-), NO3-, and K+ are grouped together in the first factor, indicating their probable contribution from combustion, Ca2+, Mg2+, and NH4+ are grouped in factor II, which may be attributed to road dust and soil, and factor III includes mainly Na+ and F-, probably contributed from brick-kiln industries. Atmospheric concentrations of F-, Cl-, NOs-, SO4(2-), Na+, K+, Ca2+, Mg2+, and NH4+ were found to be 0.38, 2.28, 1.31, 2.74, 0.44, 0.59, 1.21, 1.2, and 2.29 microg m(-3), respectively.

Atmospheric dry deposition to leaf surfaces at a rural site of India.

Dry deposition flux of major ions (Na+, K+, Ca2+, Mg2+, NH4+, F-, Cl-, NO3- and SO4(2-) to natural surfaces [guava (Psidium guyava) and peepal (Ficus religiosa) leaves] are determined at Rampur, a rural site of semi-arid region of India. Dry deposition flux is the highest for Ca2+ on guava leaves and for NH4+ on peepal leaves. Overall dry deposition flux is higher on guava leaves than of peepal leaves. The variation in deposition flux may be due to surface characteristics (surface roughness) and arrangement of leaves. Peepal leaves are arranged along the axis of the stem, whereas guava leaves are at right angles to the stem. The deposition flux of cations contributes 66% and 76% of dry deposition of all major ions on guava and peepal leaves, respectively as soil is major contributor towards dry deposition flux in tropical regions. ANOVA revealed no significant seasonal difference in deposition, although there is a trend for higher in winter. Deposition velocities of NH4+, NO3- and SO4(2-) are greater on guava leaves than peepal leaves, which can be attributed to the rougher surface of the guava leaf.

Measurements of major ion concentration in settled coarse particles and aerosols at a semiarid rural site in India.

Deposition rates and deposition velocities of water-soluble ions (F, Cl, NO3, SO4, NH4, Ca, Mg, Na and K) were measured at a rural site (Gopalpura, Agra). Dry deposition samples were collected throughout the year from December 1995 to August 1997, while the aerosol samples were collected only during the winter season of 1996. Surrogate technique was used to collect the dry deposition samples, while aerosol samples were collected on PTFE membrane filter. Deposition velocities (Vd) of SO4 and NO3 are < or = 0.01 m s(-1) while Ca, Mg, Na, K, NH4, F and Cl exhibit greater than 0.01 m s(-1) Equivalent concentration ratios of K/Na, Ca/Na and Mg/Na conform with the corresponding ratios of local soil, indicating the dominant contribution of local sources. Deposition rates are maximum in winter, followed by summer and monsoon. No significant differences are found in dry deposition rates of all ions or in atmospheric concentrations of soil-derived elements with respect to wind direction. However, in aerosols, concentrations of F, Cl, NO3 and SO4 are higher with winds from southwesterly and westerly directions corresponding to pollution sources located in these directions. Deposition data have been used to calculate the critical load of S and N for soil with respect to Triticum vulgaris. The critical load of actual acidity was found to be 622.4 eq ha(-1) year(-1) within the range of 500-1,000 eq ha(-1) year(-1) as assessed by the RAINS-Asia model for this region. The present load of S and N (77.4 and 86.4 eq ha(-1) year(-1)) was much lower than the critical load of S and N (622.4 and 2,000 eq ha(-1) year(-1)), indicating that at present there is no harmful effect on ecosystem structure and function.

Identification of the nature and source of atmospheric aerosols near the Taj Mahal (India).

The chemical composition of aerosol samples collected at Agra near the Taj Mahal during April 1991-June 1992 was identified by wet chemical analysis. The average concentration of suspended particulate matter (SPM) was 368.5 µg m(-3), ranging between 83 and 1305 µg m(-3), depending upon the season. Elevated levels of Na, SO4, Mg, NO3 and Cl compared to levels reported worldwide were attributed to the suspension of soil particles, as well as industrial emissions. Geometric mean enrichment factors of elements indicated two groups; one having enrichment factors less than 7 which were comprised of Na, K, Ca, Mg, Fe, Al, Mn and Si (crustal) and the other having enrichment factors greater than 13 and which were comprised of Ni, Cu, Zn, Pb, and Cd (non-crustal). Principal component analysis revealed the association of the first principal component with soil-derived elements while the second, third and fourth principal components were associated with industrial processes, wood combustion and brick kilns respectively. The study indicates that near the Taj Mahal the dominance of natural sources may enhance the degree of deterioration of the marble surface if micro-climatological conditions favour its wetting.

Observation of lipid profile and lipoproteins in viral hepatitis and hepatic coma.

Lipid profile and lipoprotein levels were estimated in 35 patients of viral hepatitis, 15 patients of viral hepatitis with coma and in age and sex match 35 healthy controls. The values were compared in different groups. Levels of triglycerides were significantly raised (145.00 +/- 30.70 mg/dl) in viral hepatitis as compared to viral hepatitis with coma (111.40 +/- 16.80 mg/dl) which were similar to controls (110.8 +/- 20.6 mg/dl). Patients who recovered had higher levels of triglycerides (136.0 +/- 30.8 mg/dl) as compared to those who expired (110 +/- 15.72 mg/dl). Total serum cholesterol remained statistically unaltered in both groups. HDLc was significantly decreased in both groups, viral hepatitis (2.23 +/- 6.7 mg/dl) and viral hepatitis with coma (16.52 +/- 2.27 mg/dl) in comparison to controls (62.21 +/- 18.04 mg/dl). The levels were much lower in patients with coma than without coma. Furthermore the values were still lower in patients who expired (15.82 +/- 2.27 mg/dl) than in patients who recovered (24.13 +/- 7 mg/dl). The levels of LDLc were significantly raised in both groups, as compared with each other and in relation to mortality. VLDLc levels were significantly decreased in patients of viral hepatitis (22.13 +/- 5.8 mg/dl) as well as on viral hepatitis with coma (21.89 +/- 4.3 mg/dl). However, no significant difference was observed when compared with each other and in relation to mortality. Thus it may be concluded that isolated low value of HDLc in viral hepatitis may be used as a prognostic indicator.

A study of nerve conduction velocity in patients on diphenylhydantoin therapy.

Peripheral nerve conduction studies were performed in 30 epileptics, treated with DPH and results were compared with age and sex matched controls. There was significant reduction in the amplitude of sensory nerve action potential of median (26.65 +/- 14.71 mu v) and superficial radial nerve (25.65 +/- 10.08 mu v) (p < 0.001) in DPH treated group as compared to controls, (median nerve 42.64 +/- 15.93 uv and superficial radial nerve 40.72 +/- 24.74 mu v). The results suggest that DPH causes a subclinical distal axonal neuropathy in therapeutic dosage.

Factors affecting alkaline nature of rain water in Agra (India).

Rain water was collected and analysed from a reference site, Dayalbagh and Taj Ganj, near the Taj Mahal in Agra. The ionic components Ca, Mg, Na, K, NH(4), Pb, Fe, Zn, SO(4), HCO(3), Cl and F were analysed along with pH, alkalinity and conductance. The average pH of rain water at both sites is 7.05. There is a dominance of alkaline components, particularly Ca. The rain water chemistry shows the importance of calcareous soil-derived materials in controlling the pH of rain water.

A study of aluminum phosphide (AlP) poisoning with special reference to electrocardiographic changes.

Ninety patients with aluminum phosphide poisoning have been studied over a period of 3 years. Epigastric pain and vomiting were the common initial clinical features, followed 12 to 24 hours later by cardiogenic shock, oliguria, altered mental state and respiratory distress. Death occurred within 24 to 72 hours presumably due to poison-induced toxic chemical myocarditis as reflected by electrocardiographic changes. The overall mortality was 63.3%. Intravenous magnesium sulphate, probably due to its membrane stabilizing action, appears to be related to the reduction in mortality from 90% to 52% in the latter 62 cases.

Differentiation of the sexually dimorphic nucleus in the preoptic area of the rat brain is inhibited by postnatal treatment with an estrogen antagonist.

The volume of the sexually dimorphic nucleus in the preoptic area (SDN-POA) of the rat brain is several fold larger in adult male rats that in adult females. This sex difference in brain structure was previously shown to develop under the influence of androgenic and estrogenic hormones during the perinatal period. We here report that treatment of newborn male and female rats with the estrogen antagonist tamoxifen significantly inhibited growth and differentiation of the SDN-POA in both sexes and it resulted in permanent anovulatory sterility in females. The findings suggest (a) that testicular androgens exert their growth promoting activity on SDN-POA development only after being converted into estrogens, and (b) that also in the female rat structural and possibly functional brain differentiation is under estrogenic control.