Activity of cyclooxygenase-2 and nitric oxide in milk leucocytes following intramammary inoculation of a bio-response modifier during bovine Staphylococcus aureus subclinical mastitis

The objective of the study was to evaluate the effects of intramammary infusion of a bio-response modifier (BRM) prepared from Nocardia globerula on certain inflammatory markers and percentage of neutrophil/lymphocyte in mammary secretions during bovine Staphylococcus aureus subclinical mastitis (SCM). The somatic cell count (SCC), total bacterial count (TBC) in milk, cyclooxygenase-2 (COX-2) activity, production of nitrite and nitrate (NOx) in milk leukocytes and neutrophil % and lymphocyte % in milk were evaluated before and after intramammary infusion of BRM in healthy and quarters inflicted with S. aureus SCM. Intramammary infusion of BRM significantly enhanced the SCC in earlier phase with subsequent reduction on day 7 after initiation of treatment. Whereas, the reduction of TBC was observed from day 3 onwards. The COX-2 activity and NOx production in milk cell increased initially on day 3 of post treatment but reduced on day 5 in SCM infected quarters following BRM infusion. The neutrophil % and lymphocyte % in milk also enhanced significantly on day 3 but reduced on day 5 in SCM infected quarters in response to BRM infusion. Initial influx of SCC, increased neutrophil%, lymphocyte % and enhanced COX-2 and NOx activity indicate the immunomodulatory potential of BRM in S. aureus SCM. Reduction of TBC could be due to increased leukocytosis or direct microbicidal activity of the activated milk cells. The beneficial effect of the BRM could be used as alternative therapy in the control of S. aureus SCM in cows, either alone or in conjunction with antibiotic therapy.     

A single blastomere sexing of caprine embryos by simultaneous amplification of sex chromosome-specific sequence of SRY and amelogenin genes

The primary objective of this study was to develop a simplified, rapid and authenticated protocol for sexing of caprine embryos. Polymerase chain reaction (PCR) is a powerful tool in preimplantation sex diagnosis, using embryo biopsy at the early developmental stage. Based on the amelogenin gene located on the conserved region of the sex chromosome, a primer pair was used and PCR was established to amplify a 262-bp fragment from the Xchromosome in female goat embryos and 262-bp fragments from the X chromosome and 202-bp fragments from the Y chromosome in male embryos. To validate the reliability of PCR, using the sex-determining region Y (SRY) gene located on the conserved region of Y chromosome, a primer pair was used and PCR was established to amplify a 122-bp fragment specific to the Y chromosome in male embryos. The in vitro-produced goat in vitro fertilisation (IVF)-embryos were made zona free by treating with pronase. The cell number in each embryo was counted before sexing. A single blastomere taken from these embryos was directly used as a template in PCR containing SRY and amelogenin gene-specific primers separately. Of 75 pronase-treated and 60 micromanipulated goat IVF embryos, 33 (44%) and 26 (43.33%) were confirmed as male and 42 (56%) and 34 (56.66%) as female, respectively. The sex-diagnosed embryos were kept in research vitro cleavage (RVCL) medium, and developed into 42.66% and 61.66% morulae and 13.33% and 23.33% blastocysts among pronase-treated and micromanipulated embryos, respectively. The AMELX gene-specific primer served as the internal control and did not interfere with amplification of the Y-specific sequence. In conclusion, a single blastomere sexing protocol based on the SRY and the amelogenin gene is simple, rapid, sensitive and efficient for sex determination in caprine early stage embryos.     

Fiber composite alloys: preparation by controlled dissociation of metallic solid solutions

Fiber-reinforced alloys have been prepared by the controlled dissociation of gold-nickel and aluminum-zinc solid solutions. To cause the dissociation, the alloys were taken from a one-phase field to a two-phase field by lowering the temperature. The new two-phase structure was in each case formed by diffusion controlled processes, and under certain conditions one of the new equilibrium phases appeared in the form of fibers, a few tenths of a micron in diameter, embedded in a matrix of the other. The precipitated phase first appeared in the form of spherical particles, but these aligned and then coalesced to form the fibers.     

Surface properties of lunar samples

Fine-grained samples disrupted after exposure to oxygen and oxygen with 3.5 percent water above 2 torr. Chemical etching revealed plastic deformation in some samples, adhesion due to impact melting in others, dislocations in crystalline phases and evidence that some glasses were partially devitrified. Specimens of rock that were fractured in ultrahigh vacuum exhibited a time-dependent adhesion and a network of localized electrostatically charged areas.