PubMed Health⌕ Search

Biomedical subjects

C Hay

Publications and source records attributed to C Hay.

23 records · Page 2Linked to original sources

Arthroscopic removal of a fragment from an intercondylar eminence fracture of the tibia in a two-year-old horse.

A 2-year-old Standardbred colt was admitted because of lameness of the left hind limb. Physical examination revealed marked effusion of the left femoropatellar and femorotibial joints and grade IV/V lameness of the left hind limb. Radiography of the left stifle revealed a complete fracture of the medial tubercle of the intercondylar eminence of the tibia. Arthroscopy was used to provide diagnostic, therapeutic, and prognostic information. A cranial approach to the medial compartment of the femorotibial joint was performed. Manipulation of the medial tubercle revealed it to be unstable, but a direct view of the fracture was obscured by the cranial cruciate ligament. The fracture fragment was removed, and visual inspection revealed approximately half of the cranial cruciate ligament at its insertion on the intercondylar eminence to be compromised. Fourteen months after surgery, the horse had trained and had raced without lameness. Accurate evaluation of the intra-articular soft-tissue structures of the stifle is important because ligamentous and/or meniscal injuries often are the limiting factors in determining the potential for a successful outcome and future athletic performance.

Animals↗

Temperature effect on the human dive response in relation to cold water near-drowning.

To facilitate analysis of mechanisms involved in cold water near-drowning, maximum breath-hold duration (BHD) and diving bradycardia were measured in 160 humans who were submerged in water temperatures from 0 to 35 degrees C at 5 degrees C intervals. For sudden submersion BHD was dependent on water temperature (Tw) according to the equation BHD = 15.01 + 0.92Tw. In cold water (0-15 degrees C), BHD was greatly reduced, being 25-50% of the presubmersion duration. BHD after brief habituation to water temperature and mild, voluntary hyperventilation was more than double that of sudden submersion and was also dependent on water temperature according to the equation BHD = 38.90 + 1.70Tw. Minimum heart rate during both types of submersions (diving bradycardia) was independent of water temperature. The results are pertinent to accidental submersion in cold water and show that decreased breath-holding capacity caused by peripheral cold stimulation reduces the effectiveness of the dive response and facilitates drowning. These findings do not support the postulate that the dive response has an important role in the enhanced resuscitatibility associated with cold water near-drowning, thereby shifting emphasis to hypothermia as the mechanism for this phenomenon.

Adult↗

Separation of beta-N-acetylglucosaminidase isoenzymes from liver and plasma of six mammalian species by DEAE-cellulose chromatography.

1. The beta-N-acetylglucosaminidase (EC 3.2.1.30) activities of human, pig, calf, lamb, rat and rabbit liver and plasma have been investigated. 2. All preparations had maximum activity between pH 4.0 and 4.5 and Km values with the substrate 4-methylumbelliferyl-2-acetamido-2-deoxy-beta-D-glucopyranoside ranged from 0.54 to 2.54 mM. 3. The isoenzyme profiles of liver and plasma beta-N-acetylglucosaminidase activity were compared using DEAE-cellulose chromatography. In all species the major anionic component of liver (beta-N-acetylglucsaminidase A) was eluted at a higher salt concentration than the most anionic plasma isoenzyme. 4. The plasma beta-N-acetylglucosaminidase A isoenzyme of all species contained sialic acid residues whereas only the rabbit, pig and calf liver isoenzymes were sialylated.

Acetylglucosaminidase↗