Mitochondrial DNA evolution in the genus Equus

Employing mitochondrial DNA (mtDNA) restriction-endonuclease maps as the basis of comparison, we have investigated the evolutionary affinities of the seven species generally recognized as the genus Equus. Individual species' cleavage maps contained an average of 60 cleavage sites for 16 enzymes, of which 29 were invariant for all species. Based on an average divergence rate of 2%/Myr, the variation between species supports a divergence of extant lineages from a common ancestor approximately 3.9 Myr before the present. Comparisons of cleavage maps between Equus przewalskii (Mongolian wild horse) and E. caballus (domestic horse) yielded estimates of nucleotide sequence divergence ranging from 0.27% to 0.41%. This range was due to intraspecific variation, which was noted only for E. caballus. For pairwise comparisons within this family, estimates of sequence divergence ranged from 0% (E. hemionus onager vs. E. h. kulan) to 7.8% (E. przewalskii vs. E. h. onager). Trees constructed according to the parsimony principle, on the basis of 31 phylogenetically informative restriction sites, indicate that the three extant zebra species represent a monophyletic group with E. grevyi and E. burchelli antiquorum diverging most recently. The phylogenetic relationships of E. africanus and E. hemionus remain enigmatic on the basis of the mtDNA analysis, although a recent divergence is unsupported.      

Cassava leaf harvesting as vegetables; a cause of vulnerability of cassava plant to cassava mosaic disease and eventual yield reduction: Ernte von cassavablättern als gemüse; eine ursache für die anfälligkeit der cassavapflanze für die cassava-mosaikkrankheit und für spätere ertragseinbußen

The consequence of harvesting young leaves of cassava as vegetable on the vulnerability of the crop to cassava mosaic disease (CMD) and on storage root yield was investigated using 30 cassava genotypes planted in IITA fields located in the humid forest (Port Harcourt?:?Onne), forest-savannah transition (Ibadan), southern guinea savannah (Mokwa) and northern guinea savannah (Zaria) agroecologies in Nigeria. Tender apical leaves and shoots of the cassava genotypes were removed from forty plants per cassava genotype with the same number of plants considered as control. Whitefly infestation, disease incidence (DI) and symptom severity (ISS) of the disease were assessed at monthly interval for six months and also at the ninth month after planting (MAP). Yield reduction due to this treatment was calculated as percentage harvest index (HI). Whitefly population fluctuated throughout the period of observation at all locations with higher population obtained generally for treated plants compared to control plants. Sprouting leaves of some treated genotypes were observed with severe mosaic symptoms, while corresponding control showed no mosaic symptoms. Contrarily, no remarkable difference was observed in Zaria between the mean ISS of treated and control cassava genotypes. There was a highly significant difference (P?<?0.01) in DI and ISS among cassava genotypes across all locations. Also, there was a highly significant interaction (P?<?0.01) in symptom severity between location (loc) and genotype, genotype and treatment (trt), loc and trt. Interaction between loc, genotypes and trt with regard to DI was highly significant at 2, 3 and 4 MAP, while with ISS, the interaction was highly significant all through the counting period. There was a positive relationship between DI and ISS on plants of genotypes 96/1039 and ISU. The percentage HI (27.4) of treated plants of genotype 95/0166 in Ibadan was remarkably lower than the value obtained for corresponding control (41.9) plants. Also, sharp distinction in% HI of treated (39.5) and control (43.8) ISU was observed in Onne with their respective ISS values as 3.7 and 3.2. Therefore, harvesting tender apical leaves and shoots of cassava as vegetables should be discouraged as it increases the severity of CMD infection in the regenerating shoots of cassava with attendant storage root yield reduction.     

Prevention and treatment of pregnancy-induced hypertension (preeclampsia) with progestogens

Available data indicate that progesterone is able to treat pregnancy-induced hypertension (preeclampsia). Dydrogesterone and 17alpha-hydroxyprogesterone caproate might also be used for this purpose. Prevention of hypertensive disorders in preeclampsia also seems possible, but studies are needed to confirm this.     

Formulation and optimization of mouth dissolve tablets containing rofecoxib solid dispersion

The purpose of the present investigation was to increase the solubility and dissolution rate of rofecoxib by the preparation of its solid dispersion with polyvinyl pyrrolidone K30 (PVP K30) using solvent evaporation method. Drug-polymer interactions were investigated using differential scanning calorimetry (DSC), x-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). For the preparation of rofecoxib mouth dissolve tablets, its 1∶9 solid dispersion with PVP K30 was used with various disintegrants and sublimable materials. In an attempt to construct a statistical model for the prediction of disintegration time and percentage friability, a 3² randomized full and reduced factorial design was used to optimize the influence of the amounts of superdisintegrant and subliming agent. The obtained results showed that dispersion of the drug in the polymer considerably enhanced the dissolution rate. The drug-to-carrier ratio was the controlling factor for dissolution improvement. FTIR spectra revealed no chemical incompatibility between the drug and PVP K30. As indicated from XRD and DSC data, rofecoxib was in the amorphous form, which explains the better dissolution rate of the drug from its solid dispersions. Concerning the optimization study, the multiple regression analysis revealed that an optimum concentration of camphor and a higher percentage of crospovidone are required for obtaining rapidly disintegrating tablets. In conclusion, this investigation demonstrated the potential of experimental design in understanding the effect of the formulation variables on the quality of mouth dissolve tablets containing solid dispersion of a hydrophobic drug.     

Biomarkers of toxicity in Clarias gariepinus exposed to sublethal concentrations of polycyclic aromatic hydrocarbons

Physiological, biochemical and histological indices in Clarias gariepinus broodstock, and teratogenic indices in embryos exposed to sublethal concentrations of naphthalene, phenanthrene and pyrene were investigated in 2014 using a static-renewal bioassay protocol. Phenanthrene (1.41 mg l^?1) was the most toxic, followed by pyrene (1.53 mg l^?1) and naphthalene (7.21 mg l^?1), based on 96 h LC50 values. Hepatosomatic indices were significantly higher in naphthalene- and pyrene-treated males compared with solvent controls, whereas fecundity in females was significantly lower by factors of 2.4 (naphthalene), 2.8 (phenanthrene) and 2.4 (pyrene), compared with controls. Catalase levels were lower in female phenanthrene-treated fish compared with controls. Histological alterations observed in PAH-treated fish include oedema, inflammatory cells, epithelial lifting and hyperplasia in the gills, vacuolation, haemosiderin pigments and sinusoidal congestion in the liver, and degenerated zona radiata in the ovary. Teratogenic effects were not observed, as evidenced by the lack of histological alterations in embryos spawned from pre-exposed broodstock. Sex-specific responses and the utility of biomarkers at cellular and individual levels of organisation are therefore demonstrated for holistic evaluations of polycyclic aromatic hydrocarbons in ecotoxicological studies.     

Formulation of anastrozole microparticles as biodegradable anticancer drug carriers

The purpose of this study was to develop poly(d,1-lactic-coglycolic acid) (PLGA)-based anastrozole microparticles for treatment of breast cancer. An emulsion/extraction method was used to prepare anastrozole sustained-release PLGA-based biodegradable microspheres. Gas chromatography with mass spectroscopy detection was used for the quantitation of the drug throughout the studies. Microparticles were formulated and characterized in terms of encapsulation efficiency, particle size distribution, surface morphology, and drug release profile. Preparative variables such as concentrations of stabilizer, drug-polymer ratio polymer viscosity, stirring rate, and ratio of internal to external phases were found to be important factors for the preparation of anastrozole-loaded PLGA microparticles. Fourier transform infrared with attenuated total reflectance (FTIR-ATR) analysis and differential scanning calorimetry (DSC) were employed to determine any interactions between drug and polymer. An attempt was made to fit the data to various dissolution kinetics models for multiparticulate systems, including the zero order, first order, square root of time kinetics, and biphasic models. The FTIR-ATR studies revealed no chemical interaction between the drug and the polymer. DSC results indicated that the anastrozole trapped in the microspheres existed in an amorphous or disordered-crystalline status in the polymer matrix. The highest correlation coefficients were obtained for the Higuchi model, suggesting a diffusion mechanism for the drug release. The results demonstrated that anastrozole microparticles with PLGA could be an alternative delivery method for the long-term treatment of breast cancer. Published: July 21, 2006     

Engineering two mutants of cDNA-encoding G2 subunit of soybean glycinin capable of self-assembly <Emphasis Type="Italic">in vitro</Emphasis> and rich in methionine

The main goal of this work was to make the cDNA-encoding subunit G2 of soybean glycinin, capable of self-assembly in vitro and rich in methionine residues. Two mutants (pSP65/G4SacG2 and pSP65/G4SacG2HG4) were therefore constructed. The constructed mutants were successfully assembled in vitro into oligomers similar to those occurred in the seed. The successful self-assembly was due to the introduction of Sac fragment of Gy4 (the codons of the first 21 amino acid residues), which reported to be the key element in self-assembly into trimers. The mutant pSP65/G4SacG2HG4 included the acidic chain of Gy4 (HG4), which was previously molecularly modified to have three methionine residues. This mutant will be useful in the efforts to improve the seed quality.     

Comparative study on the efficacy of neemix and basil oil formulations on the cowpea aphid Aphis craccivora Koch

Both neemix and basil oil had an insecticidal effect against Aphis craccivora Koch when the plant was treated systematically or by contact. The tested compounds caused a significant reduction in fecundity, longevity and the natal period. In addition, neemix and basil oil had a toxic effect on the adult stage of the pest, which was more clear for basil oil than neemix, since the cumulative percent morality reached 100% in all tested concentrations after 7 days for basil treatment and after 8 days for neemix oil treatment, while the mortality did not exceed 36% for the control. The two tested oils also had an antifeedant and aphicidal effect on the nymphal stage, since they caused prolongation of the nymphal duration, high percentage of mortality and only a few young ones can be succeeded to reach to the adult stage. The correlation between the biological effects of the tested compounds and the impairment of the activity of some enzymes (acid phosphatase and alkaline phosphatase) and (aspartate aminotranferase and alanine aminotransferase) as well as protein contents had also been investigated. The results clarified a significant reduction in all the tested enzymes and were more pronounced for basil oil treatment than neemix. This explained the reduction in the reproductive potency of A. craccivora Koch. Concerning the side effect of the tested compounds on faba bean plants, the results indicated that the treatment induced promising effect on the antioxidant enzymes activity (superoxide dismutase, catalase, peroxidase and polyphenol oxidase) of the plants which were treated with basil oil and neemix.     

Molecular Manipulation and Modification of the <Emphasis Type="Italic">Gy2</Emphasis> and <Emphasis Type="Italic">Gy4</Emphasis> Genes Encoding Glycinin Subunits in Soybean Seeds

The Gy2 and Gy4 genes encoding glycinin subunits were molecularly manipulated and modified to test the possibility of increasing the nutritional value of soybean seed proteins. With the respective recombinant DNAs (pSP65/G2HG4, pSP65/G4HG2, pSP65/248Metl, pSP65/248Met2,3, and pSP65/248Metl,2,3), the in vitro translation was used to produce (i) chimeric proteins consisting of reciprocally exchanged acidic and basic domains of the G2 and G4 subunits, and (ii) G4 point mutants with increased number of methionine residues. The ability of the recombinant proteins to assemble into proper quaternary structures was inspected by sucrose gradient fractionation. The produced data could provide valuable clues for the potential improvement of the genetically modified crops.__________From Fiziologiya Rastenii, Vol. 52, No. 3, 2005, pp. 412–420.Original English Text Copyright © 2005 by Sammour.This article was submitted by the author in English.     

<i>Streptomyces</i> PRIO41 as plant growth promoter of jalapeño pepper plants and as biocontrol agent of <i>Fusarium</i>

Chili pepper is one of the main crops of economic importance in Mexico, and Fusarium wilting is a disease that limits its production. In addition, the inappropriate use of agrochemicals in farming activities generate environmental and health problems. Therefore, in this study the effectiveness of Streptomyces sp PRIO41 was evaluated as a (1) biocontrol agent of Fusarium spp and (2) plant growth promoter bacteria. Assays of pathogenicity and virulence of Fusarium spp. in jalapeño pepper seeds, and interactions of these pathogens with Streptomyces PRIO41 were evaluated under two nutritional conditions. In the greenhouse, the effectiveness of Streptomyces sp. PRIO41 was determined as a (1) biocontrol of Fusarium, and (2) plant growth promoter of wilt of pepper plants. The results showed that all fungal isolates caused symptoms in pepper seeds and seedlings with different degrees of virulence. Interactions in vitro showed that Streptomyces showed the most effective range of virulence against Fusarium isolates in the poor medium (37.6%-100%), with fungicidal effects in some cases. In the greenhouse, Streptomyces PRIO41 reduced Fusarium wilting up to a 40%, and positively affected all vegetative growth parameters, particularly plant height, leaf area, root length, and leaf and root dry biomasses. This study showed the potential of Streptomyces PRIO41 as a biocontrol agent of Fusarium spp., and as a biofertilizer of pepper plants.