Sequential changes in lactate,isocitrate, and malate dehydrogenases in mice exposed to technical grade hexachlorocyclohexane (BHC) and their possible relationship to liver tumors

Hexachlorocyclohexane (BHC) was fed at a 500-ppm-dose level in diet to pure inbred Swiss mice for 2, 4, 6, and 8 months. Later BHC was discontinued for 4 months and subsequently the animals were refed BHC for 1 month. The protein, lactate dehydrogenase (E.C.1.1.1.27), isocitrate dehydrogenase (E.C.1.1.1.42), and malate dehydrogenase (E.C.1.1.1.37) were studied from liver. The liver weight as percentage of body weight was also determined. The results showed an increase in the liver weight/body weight ratio and a decrease in protein and all three enzymes after BHC feeding for the different time intervals. The discontinuation of BHC in the diet resulted in the reversion of values of the above parameters toward the normal and after refeeding BHC for 1 month, the decreased values, as seen after initial BHC feeding, were again observed. This indicates that the changes in the values of lactate dehydrogenase, isocitrate dehydrogenase, and malate dehydrogenase are associated with hexachlorocyclohexane feeding in the diet. The significance of these changes is discussed.     

Content, composition, and bioactivity of the essential oils of three basil genotypes as a function of harvesting

A study was conducted to evaluate the effect of cut on biomass productivity, oil content, composition, and bioactivity of Ocimum basilicum L. (cvs. German and Mesten) and Ocimum sanctum L. (syn. O. tenuiflorum L.) (cv. Local) in Mississippi. Yields of basil herbage and essential oil were high and comparable to those reported in the literature. Essential oil content of O. basilicum cv. German varied from 0.40 to 0.75%, the oil content of cv. Mesten varied from 0.50 to 0.72%, and the oil content of cv. Local (of O. sanctum) ranged from 0.17 to 0.50% in air-dried basil. Herbage and essential oil yields of cvs. German and Mesten of O. basilicum increased with the second and then again with the third cut, whereas herbage and oil yields of cv. Local of O. sanctum increased with the third cut relative to the previous cuts. Overall, essential oil yields were 115, 123, and 51 kg/ha for the cvs. German, Mesten, and Local, respectively. The major oil constituents of cvs. German and Mesten (of O. basilicum) were (-)-linalool (30-40%) and eugenol (8-30%), whereas the major oil constituents of cv. Local (of O. sanctum) were eugenol (8-43%) and methylchavicol (15-27%). Essential oils from both species grown in Mississippi showed in vitro activity against Leishmania donovani (IC50 = 37.3-49.6 microg/mL), which was comparable to the activity of commercial oil (IC50 = 40-50 microg/mL). Minor basil oil constituents (+)-delta-cadinene, 3-carene, alpha-humulene, citral, and (-)- trans-caryophyllene had antileishmanial activity, whereas other constituents were ineffective. None of the oil was cytotoxic to mammalian cells.     

Development of a simple and rapid monoclonal antibody-based flow through immunogold assay (FIA) for detection of <Emphasis Type="Italic">Aeromonas hydrophila</Emphasis>

In this study, we developed a simple, low-cost, and rapid flow through immunogold assay (FIA) for detection of Aeromonas hydrophila in fish tissues and validated. The developed assay relied on colloidal gold conjugated highly specific monoclonal antibody (B8E3) against 20 kDa protein of A. hydrophila. The assay can be completed within 5 min including antigen (sample) preparation and exhibited no cross-reaction with other major aquatic pathogens such as Vibrio anguillarum, V. parahaemolyticus, V. harveyi, white spot syndrome virus (WSSV), and Aphanomyces invadans. A wider range of Aeromonas species were tested including A. caviae, A. dhakensis, A. sobria, A. veronii, A. culicicola, A. sharmana, and A. schubertii and no cross-reactivity could be observed. The developed technique FIA could detect 10³ CFU/ml of aeromonad cells. In addition, the FIA is as sensitive as the first-step polymerase chain reaction (PCR) and 1000 times sensitive than the immunodot blot method. The validation study revealed the accuracy of FIA by comparing with the standard first-step PCR. The proposed FIA is low-cost, easy-to-use, and compatible for field-level analysis of A. hydrophila in fish tissues. Our developed FIA could successfully detect A. hydrophila at early stage of the infection and could be easily availed by farmers, fish producers, non-technicians, and technicians in the aquaculture industry.     

Survey of the plant-available silicon status of agricultural soils in Louisiana

Adequate silicon nutrition in plants has shown positive effects on the growth and yield of the crop and physico-chemical properties of the soil. Hence, this study was initiated to survey the plant-available silicon in the agricultural soils of different parishes of Louisiana. Soil samples were collected from 212 representative agricultural fields of 27 agrarian parishes of Louisiana. Poor correlations between deionized water, calcium chloride, and other extractants suggest that the unbuffered calcium chloride extraction may reflect only a transient status of soil soluble silicon similar to deionized water extraction procedure. Also, acetic acid-2 extraction procedure may reflect the net effects of the sorption/desorption reactions by extracting the readily as well as the slowly releasable silicon that control solubility, thus giving a true measure of current availability. Compared to the previously established critical soil silicon levels, several agricultural fields of Louisiana were deemed to be low in plant-available silicon.     

Anti-abortion and Fertility Vaccine Potential of Defined Double Deletion (ΔaroAΔhtrA) Mutant (S30) of Salmonella Abortusequi in Equids

The present study on defined double deletion (ΔaroAΔhtrA) mutant (S30) of Salmonella enterica serovar Abortusequi evaluated it for safety, immunogenicity, and efficacy as a vaccine candidate in equids. The candidate strain was found safe in equids (foals, male and female horses and donkeys, and pregnant and nonpregnant mares) and induced good humoral and cell-mediated immunity on administration through oral route. The strain was not excreted in feces of vaccinated animals. The vaccine candidate administered orally (1 × 10¹¹ cfu per animal) protected mares even after 180 days of inoculation against abortion on challenge with wild-type S. Abortusequi strain whereas in nonvaccinated control, all mares aborted. The vaccination in infertile mares resulted in regaining of fertility in 67%–80% thoroughbred mares at two different breeding farms. Further, the humoral immunity was transferred to foals from vaccinated mothers through colostrum, but no placental transfer was evident. Thus, the vaccine under study may be recommended for use in equids to control S. Abortusequi infection–associated abortions and also to enhance fertility of temporarily infertile mares in endemic areas.     

Ovipositional responses of Chilo partellus (Swinhoe) (Lepidoptera: pyralidae) to natural products from leaves of two maize (Zea mays L.) Cultivars

Ovipositional responses of Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) to hexane extracts of leaves of two maize (Zea mays L.) cultivars, one resistant (Kisan) and one susceptible (Basilocal), were studied in two-choice bioassays. Gravid females laid a significantly higher percentage of eggs on substrates smeared with extract of Basilocal leaves (HEBL) (69%) than on those smeared with extracts of Kisan leaves (HEKL) (31%). Several chemicals were isolated from HEKL, three of which were characterized as dotriacontanol, heptadecanol, and nonadecanol. These chemicals were either absent or were present in very small amounts in HEBL, but in HEKL they were detected in much larger amounts. Each isolated chemical was tested for its effect on C. partellus oviposition in two-choice bioassays. Maximum ovipositional deterrence (90%) was observed for the compound MR-22a, followed in decreasing order by nonadecanol, MR-7, and heptadecanol. The identity of the remaining compounds is being investigated. The results indicate that the relative resistance of Kisan maize compared to Basilocal is partly due to the presence of certain ovipositional deterrents in its leaves.     

Molecular basis for the influence of muscle length on myocardial performance

According to Starling's law of the heart, the force of contraction during the ejection of blood is a function of the end-diastolic volume. To seek the molecular explanation of this effect, a study was made of the effects of length on Ca2+ sensitivity during tension development by isolated demembranated cardiac muscle in which the cardiac form of troponin C was substituted with skeletal troponin C. The results of troponin C exchange were compared at sarcomere lengths of 1.9 and 2.4 micrometers. Enhancement of the myocardial performance at the stretched length was greatly suppressed with the skeletal troponin C compared with the cardiac troponin C. Thus the troponin C subunit of the troponin complex that regulates the activation of actin filaments has intrinsic molecular properties that influence the length-induced autoregulation of myocardial performance and may be a basis for Starling's law of the heart.     

Host range of Alternaria alternata—a potential fungal biocontrol agents for waterhyacinth in India

The host ranges of Alternaria alternata and fungi native to India and pathogen of waterhyacinth (Eichhornia crassipes) were evaluated using 29 plant species (some with several cultivars tested) representing 18 families of economic and ecological importance. The results showed that only waterlettuce (Pistia stratiotes), another common weed in India, was infected by A. alternata. The use of these pathogens in the biological control of waterhyacinth would not be expected to affect plants of economic and ecological importance in India.     

Ration restriction,compensatory growth and pituitary growth hormone gene expression in Labeo rohita

An experiment to investigate the compensatory growth (CG) response of Labeo rohita was conducted in two phases: a first phase (6 weeks) in which triplicate groups of fish were subjected to feed restriction (5, 25, 50 and 75 % of satiation) or satiation feeding (control) and a second phase (6 weeks) of satiation feeding for all treatment groups. CG in body weight occurred in groups which were under moderate feed restriction (50–75 % of satiation) under phase 1, but more severe feed restrictions resulted in lower weight gain. Improved feed conversion ratio (FCR) (1.6 ± 0.05 and 1.9 ± 0.03) relative to control (2.1 ± 0.06) was observed in the fish that displayed CG following moderate feed restriction (50–75 % of satiation). At the end of the experiment, body moisture, lipid and protein content were not significantly different between moderately restricted fish and the control. After the first phase, there was no significant difference in the expression of pituitary growth hormone (GH) gene between groups, but at the end of the experiment, significantly lower GH expression was observed in the fish subjected to a restriction of 25 and 50 % of satiation during phase 1. Exploiting the ability of fishes to undergo CG in terms of weight gain and improved FCR without major changes in body composition can be considered as an effective management practice.     

Identification of Physiological Traits Underlying Cultivar Differences in Drought Tolerance in Rice and Wheat

Rice is used as a model cereal to study drought response at the molecular level, with the goal of applying results to other cereals. To assess the relevance of results from rice to other species, the kinetics of drought development and plant response of tolerant and susceptible tropical rice ( Oryza sativa L.) and subtropical wheat ( Triticum aestivum L.) cultivars were compared under vegetative and reproductive stage drought in pot experiments. Water was withheld during reproductive stage until plant available soil moisture content was 30 % of field capacity (FC) or leaf wilting was observed, and then reapplied. Rice reached 30 % FC 9 days after withholding water and wheat after 13 days. Before rewatering, both species reached leaf water potentials of −12 bars and similarly low transpiration rates. Stress reduced leaf relative water content, leaf elongation and membrane stability. When water stress was imposed during reproductive stage, pollen fertility was most affected in wheat, while panicle exsertion and anther dehiscence were severely affected in rice. When water stress was imposed during vegetative stage, wheat was less affected to vegetative stage drought than rice. The nature of differences between tolerant and susceptible cultivars was similar for the two species. However, the differential growth habitats and growth rate of plants needs to be considered in these kinds of experiments.