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Biomedical subjects

M B Mahaffey

Publications and source records attributed to M B Mahaffey.

25 records · Page 2Linked to original sources

Effect of staphylococcal alpha-toxin pancreatitis on glucose tolerance in the dog.

Acute pancreatitis was experimentally produced in dogs to study the effect of the disease on glucose tolerance. The k value (glucose disappearance coefficient measured in percentage decrease of glucose/min) calculated from the high-dose intravenous glucose-tolerance test was used to evaluate the glucose tolerance of each dog. Thirty dogs were allotted to 3 groups of 10 dogs each as follows: group I--nonsurgical control dogs; group II--surgical control dogs; and group III--pancreatitis-affected dogs. To increase their susceptibility to diabetes, 50% partial pancreatectomies and ductal catheterizations were performed on group II and III dogs. Saline solution was infused into the ductal systems of group II dogs, and staphylococcal alphatoxin was infused into the ductal systems of group III dogs to produce pancreatitis. The results indicated that (1) high-dose intravenous glucose-tolerance test was an effective tool for determining decreased glucose tolerance in dogs; (2) glucose tolerance of group III dogs was markedly decreased compared with that of group I and II dogs; (3) staphylococcal alpha-toxin produced signs of moderately severe pancreatitis; and (4) 50% partial pancreatectomy and saline solution infusion produced clinical and clinicopathologic signs of mild pancreatitis. To determine if a simplified k value (calculated using 2 or 3 blood samples) could closely approximate the standard k value (calculated using 6 blood samples), simplified k values were derived from the 5- and 60-minute blood sample values. These values closely approximated the standard k values, indicating the simplified value may be used in the clinical situation. The standard k value, however, is preferred for investigative work.

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Echocardiographic detection of flail left atrioventricular valve cusp from ruptured chordae tendineae in 4 dogs.

Echocardiography was used to identify a flail left atrioventricular valve cusp caused by ruptured chordae tendineae in each of 4 dogs; two-dimensional echocardiography was superior to M-mode echocardiography in identifying the flail cusps. The following findings on two-dimensional imaging were characteristic: the tip of the flail cusp extended beyond the line of left atrioventricular valve cusp closure and pointed toward the left atrium in systole; the tip was thrust into the left ventricle, and then toward the left ventricular outflow tract in diastole, forming a convex surface to the cusp, which faced toward the left ventricle. The flail motion of the left atrioventricular valve cusp was best observed in the right parasternal long axis or left apical four-chamber views, in a plane parallel to the long axis of the left ventricle and left atrium. Rupture of chordae tendineae leading to flail cusp was attributed to chronic valve degeneration (endocardiosis) in all 4 dogs. Echocardiographic or clinical diagnoses were confirmed by postmortem gross and microscopic studies in all dogs.

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Fluoroscopically guided percutaneous disk aspiration in 10 dogs with diskospondylitis.

Fluoroscopically guided percutaneous fine-needle aspiration of the intervertebral disk space was performed in 10 dogs with diskospondylitis. Positive bacterial cultures were obtained from 9 of 12 aspirated disk spaces, 1 of 6 blood cultures, and 6 of 10 urine cultures. Positive disk cultures were obtained from 2 dogs with negative blood and urine cultures and from 2 additional dogs with low numbers of Staphylococcus in urine cultures. Adverse clinical sequelae of the procedure were not noted. Percutaneous fine-needle aspiration of the intervertebral disk space is an alternative technique to surgical biopsy to obtain positive bacterial cultures from dogs with diskospondylitis.

Animals↗

Gallbladder mucocele causing biliary obstruction in two dogs: ultrasonographic, scintigraphic, and pathological findings.

Two dogs were found to have intraluminal gallbladder masses which caused partial or complete extrahepatic biliary obstruction. On histological examination, the gallbladder masses were confirmed to be mucoceles. Gallbladder mucoceles are rare in humans and previously have been described only after gallbladder rupture in two dogs. In the dogs of this report, the biliary obstruction was relieved by cholecystectomy. Each dog also had histological evidence of chronic liver disease with intrahepatic cholestasis. The clinical diagnosis of biliary obstruction was based on scintigraphic and sonographic findings which will be discussed and compared with other hepatobiliary diseases.

Animals↗

Accessory lung lobe torsion and chylothorax in an Afghan hound.

Torsion of the accessory lung lobe is extremely rare and has been reported only in one human. Accessory lung lobe torsion (LLT) and chylothorax occurred in a 3.5-year-old, male Afghan hound. An exploratory thoracotomy was used to remove the torsed lung lobe. When medical management of the chylous effusion failed, thoracic duct ligation was performed, resulting in resolution of the effusion. The dog remains clinically healthy 29 months postoperatively.

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Contrast radiographic findings in canine bacterial discospondylitis: a multicenter, retrospective study of 27 cases.

A multicenter, retrospective study was undertaken to evaluate contrast radiographic findings in canine bacterial discospondylitis. Records and myelograms or epidurograms of 27 patients were obtained from five colleges of veterinary medicine. Fifteen cases (56%) were evaluated as having some degree of spinal cord compression. The majority (73.3%) of the cases had only soft tissue as the compressive mass. The median compression for all cases was 5% of the vertebral canal. No difference was noted for compression based on anatomical site (i.e., cervical versus thoracolumbar versus lumbosacral). No significant correlation between degree of lesion compression and clinical outcome was noted, but there was a trend toward increased mortality with greater compression. There was no correlation between the ambulatory status and the ultimate outcome. Three of the 15 (20%) cases showed vertebral subluxation. Results of this study indicate that static spinal cord compression is not a significant component of the neurological dysfunction associated with bacterial discospondylitis. Identification of vertebral subluxation in some patients may indicate a dynamic lesion that should be evaluated with stress radiography.

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