No abstract

Blood samples were collected simultaneously from the pulmonary artery, jugular vein, cephalic vein, and carotid artery in awake dogs. Blood-gas and acid-base values were measured from these blood samples in normal dogs and in dogs after production of metabolic acidosis and metabolic alkalosis. The values obtained from each of the venous sites were compared with those obtained from arterial blood to determine if venous blood from various sites accurately reflected acid-base balance and could therefore be used in the clinical patient. The results of this study demonstrated significant differences between the blood from various venous sites and the arterial site for Pco2 and pH in all acid-base states. Significant differences for standard bicarbonate (SHCO,) were found only when jugular and cephalic venous blood were compared with arterial blood in dogs with a metabolic acidosis. No significant differences were found for BE when blood from the venous sites was compared with arterial blood. The values for pH, HCO,, TC02, BE, and SHCO, measured on blood collected at the various venous sites were found to correlate well with those obtained from arterial blood, with a correlation coefficient of 0.99 for HCO,, TC02, BE, and SHCO,. These correlation coefficients, together with similar values in BE at all collection sites, indicate that, in the dog with normal circulatory status, blood from any venous site will accurately reflect the acid-base status of the patient. (Journal of Veterinary Internal Medicine 1991; 5:294-298) BLOOD-GAS and acid-base status are usually determined on blood collected from an artery, although it has been suggested that mixed venous blood may better reflect the changes in the tissues and therefore may be a better indicator of acid-base changes.' In some small animals, arterial or mixed venous blood samples are not easily obtained; therefore, several workers have compared blood collected from venous sites with arterial blood to determine if it could be used to reliably indicate blood-gas and acid-base b a l a n~e .~-~ Most of these studies have compared arterial blood and blood collected from one peripheral venous site. In some cases, the samples were not collected simultaneously.This study determined if the measurement of bloodgas and acid-base values from venous blood accurately reflected values obtained from arterial blood in dogs with normal and abnormal acid-base states. A number of different venous sites were sampled to determine if more accurate values were obtained by sampling from any one site. Materials and MethodsFive crossbred dogs were prepared by implantation of catheters in the carotid artery, jugular vein, and pulmonary artery and trained to lie quietly for the collection of blood samples. Arterial, jugular venous, and mixed venous blood samples were collected from the implanted catheters, and in all cases, collections were from free-294

An unusual giant‐cell granulomatous inflammatory oral lesion is characterised by the presence of hyaline rings and by a lack of agreement on their nature, opinions ranging from their being hyaline degenerative blood‐vessels to remains of leguminous cells. Ten such lesions and a variety of vegetables have been examined in the present investigation. Light‐microscopical examination of the lesions revealed the hyaline rings surrounded by inflamed granulation tissue with associated multinuclear giant cells. Electron‐microscopical examination showed them to consist of a material similar to that of vegetable cell walls, sometimes with an associated superficial layer of collagen. The observations indicate that the lesions consist of vegetable remains with an associated foreign‐body type of inflammatory response.

Gonadal development in fowls aged from 1 day to more than 4.5 years was studied in 63 ZZW and 16 ZZZ triploid crossbreds and compared with normal diploid males (ZZ) and females (ZW). In the ZZW fowl, the right gonad developed into a testis (although this occurred earlier in the ZZ genotype), and a structurally-abnormal excurrent duct system containing some malformed spermatids and spermatozoa was associated with the gonad of young adults. The left gonad was an ovotestes at hatching and no excurrent ducts were associated with it. The ovarian component was much less developed than that in the ZW genotype-it started to degenerate by 1 week of age, and most of the oocytes had disappeared by about 3 weeks of age. The seminiferous tubules developed in the medullary region, but only abnormal spermatozoa were produced. Leukocytes infiltrated both gonads at about 9 months of age and the seminiferous epithelium had degenerated in most fowls over 1 year old. In ZZZ fowl, gonadal and excurrent duct development was normal, but occurred earlier than in the ZZ genotype. However, meiosis and spermiogenesis were abnormal and malformed spermatozoa were produced. The heads of spermatozoa from the ducts deferens were about 1.4-times longer in the ZZZ genotype than in the ZZ genotype, indicating that the former may be producing some diploid spermatozoa.

Marker-quantitative trait locus (QTL) linkage was evaluated in F2 intercross and backcross mouse populations derived from stocks differing dramatically in prolificacy and mature weight. A highly prolific outbred Quackenbush-Swiss mouse line, or an inbred line derived from it (16.62 +/- 0.22 and 14.64 +/- 0.27 pups per litter, respectively) were used as one of the grandparents in these populations. The less prolific C57BL/6J inbred mouse line (6.67 +/- 0.37 pups per litter) was used as the other grandparent. Linkage was evaluated in a three-step process that involved selective genotyping of F2 intercross progeny representing extremes for prolificacy, genotyping of the full F2 for chromosomal regions potentially associated with prolificacy, and genotyping of the backcross for genomic regions significantly associated with prolificacy in the F2. Segments of Chromosomes (Chrs) 2 and 4 were significantly (P < 0.05, experiment-wise error rate) associated with prolificacy, and LOD scores suggestive of linkage were observed for litter size on Chr 9 and growth on Chrs 4 and 11. Existence of growth QTL was also supported by marker effects that were significant (P < 0.05) or approaching significance (P < 0.10) in the backcross. Additive litter size QTL effects ranged from 0.56 to 0.79 pups per litter, and dominance deviations ranged from -0.56 to 1.19 pups per litter, suggesting overdominance as a possible mode of gene action in some cases. The observation of pleiotropic or linked QTL for growth and prolificacy corresponds well with results from many selection experiments identifying positively correlated responses to selection for these two traits.