Biomedical subjects

R A Martin

Publications and source records attributed to R A Martin.

150 records · Page 9Linked to original sources

PubMedDate not supplied

Endoscopic diagnosis of chronic hypertrophic pyloric gastropathy in dogs.

The endoscopic appearance of chronic hypertrophic pyloric gastropathy (CHPG) in five dogs is described. Several patterns of enlarged mucosal folds that surrounded and obstructed the pyloric canal were observed. Initially, endoscopically obtained biopsy samples of mucosa were judged to be histologically normal. Diagnosis of CHPG was confirmed and relief of pyloric obstruction accomplished at exploratory laparotomy (in four dogs). Retrospective evaluation of pyloric tissue samples, obtained during endoscopy, identified subtle histological characteristics of CHPG. Gastric and duodenal neoplasia or antral polyps can mimic the endoscopic appearance of CHPG but can be differentiated based on their endoscopic and histological appearance. These cases show that endoscopic examination is a valuable procedure for the diagnosis of CHPG in dogs that chronically vomit.

Animals↗

PubMedDate not supplied

Sacral fractures in dogs: a review of 32 cases.

Sacral fractures have not been described well in dogs. The records of 32 dogs diagnosed with sacral fractures were evaluated for neurologic deficits at presentation and discharge. Follow-up was in the form of telephone survey or physical examination at recheck. A score was assigned for each dog at presentation, discharge, and follow-up (0 for normal, 1 for minor deficits, and 2 for major deficits). Fractures located lateral to the sacral foramina were called abaxial, and those medial to the sacral foramina were called axial. Axial fractures had significantly more severe deficits at presentation (p = 0.00017) and discharge (p = 0.03063), but not at follow-up. Neurologic status did not improve significantly during hospitalization in either fracture group, but had improved significantly at follow-up.

Accidents, Traffic↗

PubMedDate not supplied

Extrahepatic biliary tract obstruction: a retrospective study of 45 cases (1983-1993).

The medical records of 41 dogs and four cats with either surgical or postmortem confirmation of extrahepatic biliary tract obstruction were reviewed. Clinical signs of icterus, vomiting, anorexia, or a combination of these signs were exhibited by 100% of cases. Elevated serum bilirubin was documented in 37 of 41 dogs and two of four cats (86.6%). The predominant, underlying, pathological process was extraluminal obstruction of the biliary tract due to pancreatitis (19 of 45 cases; 42.2%) or neoplasia (11 of 45 cases; 24.4%). Biliary tract surgery was performed in 29 cases, of which 12 (41.3%) recovered. Animals diagnosed with extrahepatic biliary tract obstruction had a relatively good long-term prognosis, provided they were not compromised substantially due to severe necrotizing pancreatitis or neoplasia.

Animals↗

PubMedDate not supplied

Randomization of animals by computer program for toxicity studies.

Evaluations of toxic potential of drugs and chemicals often involve statistical comparisons of effects between treatment groups. Such comparisons are valid and permit elucidation of spontaneous versus treatment effects only if the sampling population is obtained without selection bias. Selection bias is routinely minimized or controlled by random sampling or unbiased allocation of animals to treatment groups. A systematic approach using a computerized procedure is described that fulfills these requirements in a simple and efficient fashion.

Animals↗

PubMedDate not supplied

Nonaqueous reverse phase liquid chromatographic analysis for cholesterol in milk chocolate.

A method using liquid chromatography was developed for the analysis of cholesterol in milk chocolate products. The method involves saponification of the sample with methanolic KOH followed by extraction with ether. Potentially interfering components are eliminated through the use of a silica Sep-Pak cleanup step before injection. The nonaqueous reverse phase LC system consists of a C18 column and an isopropanol-hexane mobile phase with direct detection at 205 nm. Recoveries of 1, 3, and 5 mg cholesterol added to 1 g sample of milk chocolate were 88.6, 102.8, and 110.1%, respectively. Studies conducted with [4-14C]-cholesterol were undertaken to further document the accuracy of the method.

Animals↗

PubMedDate not supplied

Metabolism of mouse growth hormone-releasing factor, mGRF(1-42)OH, and selected analogs from the bovine GRF series in mouse and bovine plasma in vitro.

The presence of Val2 in mGRF(1-42)OH is unique and, as shown in this study, renders this GRF resistant to plasma DPP-IV, the main enzyme responsible for rapid hydrolysis and inactivation of Ala2-containing GRFs from other species via cleavages between Ala2-Asp3. The presence of DPP-IV activity in mouse serum, and mouse and bovine plasma has been demonstrated with Gly-Pro-p-nitroanilide and/or with two DPP-IV-sensitive bGRF analogs, [Leu27]bGRF(1-29)NH2 and [Ala15,Leu27]bGRF(1-29)NH2, which were effectively converted to their respective (3-29) fragments. During incubations of mGRF(1-42)OH in mouse serum or plasma, as well as in bovine plasma in vitro, no major fragments were detectable, except for small amounts of metabolites with HPLC retention times corresponding to those of mGRF(12-42)OH and mGRF(21-42)OH, indicative of possible trypsin-like cleavages between Arg11-Lys12 and Arg20-Lys21. Both mGRF(1-42)OH (t1/2 52-78.5 min) and [Val2,Ala15,Leu27]-bGRF(1-29)NH2 (t1/2 78.5 min) disappeared 5 to 7 times faster in mouse than in bovine plasma, indicating much higher activity of various degrading enzymes in mouse plasma. In summary, our data provide evidence that mGRF(1-42)OH, despite its resistance to plasma DPP-IV, is degraded relatively fast in mouse plasma or serum because of trypsin-like and other, non-DPP-IV-related, proteolytic cleavages.

Amino Acid Sequence↗