Quantification and persistence of recombinant DNA of Roundup Ready corn and soybean in rotation

The presence of the recombinant cp4 epsps gene from Roundup Ready (RR) corn and RR soybean was quantified using real-time PCR in soil samples from a field experiment growing RR and conventional corn and soybean in rotation. RR corn and RR soybean cp4 epsps persisted in soil for up to 1 year after seeding. The concentration of recombinant DNA in soil peaked in July and August in RR corn and RR soybean plots, respectively. A small fraction of soil samples from plots seeded with conventional crops contained recombinant DNA, suggesting transgene dispersal by means of natural process or agricultural practices. This research will aid in the understanding of the persistence of recombinant DNA in agricultural cropping systems.     

Use of Contrast‐Enhanced Ultrasonography in Chronic Pathologic Canine Testes

Contrast‐enhanced ultrasound with sulphur hexafluoride microbubbles was performed in seven healthy dogs without a history of reproductive pathology and with histologically confirmed normal testes and in 42 dogs with chronic scrotal anomalies. All dogs underwent orchiectomy and histological examination. Enhancement patterns and perfusion parameters (peak intensity and regional blood flow) of testes of healthy dogs and testes with chronic lesions were compared. Fourteen non‐pathologic and 60 pathologic testes were considered. Forty testes were neoplastic (24 interstitial cell tumours, 9 seminomas, 7 Sertoli cell tumours), 20 were non‐neoplastic (16 testicular degenerations, 2 chronic orchitis, 1 testicular atrophy, 1 interstitial cell hyperplasia). In healthy dogs, the contrast medium flow had a rapid homogeneous wash‐in and wash‐out, with a short peak phase. With contrast ultrasound, testes that were inhomogeneous with a hyperenhancing pattern were associated with neoplasia (sensitivity: 87.5%, specificity: 100%). Lesions with persistent inner vessels and a hypo‐to‐isoechoic background were significantly associated with seminomas (sensitivity: 77.8%, specificity: 100%). Testes with non‐neoplastic lesions were characterized by a scant/moderate homogeneous enhancement. Perfusion parameters were higher in neoplastic lesions. Contrast ultrasound was a feasible diagnostic tool in the assessment of testicular lesions, with hyperenhancement being an important feature in the diagnosis of malignancy.     

Effect of the synthetic androgen mesterolone upon seminal characteristics of dogs

The synthetic androgen mesterolone given at 1–5 mg/kg daily in divided doses significantly increased the total sperm output of normal dogs. A dose of 3-0 mg/kg daily in divided doses significantly improved sperm morphology of an oligoasthenoteratozoospermic dog. The effects upon plasma testosterone concentration were not conclusive.     

Recombinant Bone Morphogenetic Proteins: Novel Substances for Enhancing Bone Healing

Bone morphogenetic proteins (BMPs) are differentiative factors whose principal function is to induce transformation of undifferentiated mesenchymal cells into chondroblasts and osteoblasts in a dose-dependent manner. Bone morphogenetic proteins have been isolated postnatally in mammals from bone matrix, periosteal cells, mesenchymal cells of marrow stroma, tooth anlagen, and cells of osteosarcoma and chondrosarcoma. Distribution in additional embryonic tissues implies a broader organogenic function. Bone morphogenetic proteins are the only differentiative factors able to singularly induce de novo bone formation in vitro and in vivo. Recombinant DNA technology allows their production in large and highly purified quantities. The BMPs' osteoinductive ability has been shown with a variety of carriers including collagens and polymers at heterotopic and orthotopic sites in a wide range of species. They are presently being readied for clinical use as alternatives to bone grafts. Other potential applications include use as pulp capping agents, promoters of implant osteointegration and soft tissue reunion with bone, treatments for nonadaptive bone disease, and implants for use with mitotically expanded skeletal stem cell populations. Errors in the genetic coding of BMPs may manifest as clinical disease entities.     

Biosecurity: safeguarding your veterinarian: client: patient relationship.

Biosecurity is the management practice that reduces the opportunities for infectious agents to gain access to, or spread within, a food animal production unit. As the public's concern for food safety continues to be directed toward the producer, a well-defined and well-documented biosecurity plan will be a significant factor in ensuring that animal products are safe, wholesome, and acceptable. Veterinarians are the initial control point for biosecurity and therefore are expected by their clientele and the general public to assist in establishing, defining, refining, and practicing biosecurity programs.     

Follow-up of mercury levels in fish,human hair and urine in the Madeira and Tapajós basins,Amazon, Brazil

Informal economy of gold mining has contaminated some important river basins in Amazon. Follow-up studies on critical compartments showed some areas with high Hg levels in fish as well as in human hair samples. Average Hg in piscivorous fish in the Madeira river itself was 846 ppb (N=284) with a maximum of 3921 ppb. Mercury in fish from non polluted areas in this basin shows high variability, even for single species. A seasonal variation in Hg content was observed, with higher values at the end of the dry season. In the upper Tapajós basin comparable values were found for fish but with a definite decreasing trend downstream. Average value for piscivorous fish in the whole Tapajós basin is 482 ppb (N=122) with a maximum value of 3770 ppb. Hair Hg was higher in fishing villages in the Tapajós (average: 17 ppm; with N=432 and maximum value of 176 ppm) than in the Madeira (average: 9 ppm; N=169; maximum 71 ppm), and data from some areas of the Tapajós suggest a decrease with time. Mercury was much higher in urine of goldshop workers in Santarém (low Tapajós) than in Alta Floresta (high Tapajbs) and show a decreasing trend in both cases, probably related to the significant decline in gold mining activities during the study period (1986–1994).     

RENAL AND HEPATIC ULTRASONOGRAPHY IN THE NEONATAL DOG

The ultrasonographic appearance and size of the liver and kidneys of a litter of five pups was examined from birth until six months of age, and compared with a group of five adults of the same breed. Increased renal cortical echogenicity was evident for the first two weeks of life. Up to 12 weeks of age renal size was relatively large in comparison with body size parameters. After 12 weeks measures of renal size were proportionate with body size and were not significantly different from adult dogs. The neonatal liver had a similar ultrasonographic appearance to the adult, although in the first eight weeks parenchymal echogenic stippling was less coarse and portal veins were less well delineated. Measures of hepatic length were inaccurate during the first four weeks after birth due to changes in body conformation. From eight weeks to six months of age these measures were proportionate with body size, although the ratios differed from adult dogs.     

Clinical cytogenetics in equine stud practice: Consideration of the present situation and future application

The situation in Thoroughbred breeding in relation to cytogenetics is considered and it is indicated where screening of horses will be useful in practice. The techniques involved are explained and karyotypes are illustrated. The present state of knowledge in horse cytogenetics is reviewed. The types of abnormality are described in relation to phenotype. Future promise is discussed in relation to the human field, concluding that with the refined methods now available a wider rangeof meaningful aberrations will be uncovered.