Directional coronary atherectomy in intermediate sized vessels: final results of the intermediate vessel atherectomy trial (IVAT).

Revascularization options for intermediate sized vessels (2.5-2.9 mm) have historically been limited. IVAT is a pilot study to assess the efficacy and safety of debulking intermediate sized vessels using directional coronary atherectomy (DCA). Between March 1996 and June 1997, 50 patients were enrolled at seven hospitals in the United States. Of those patients, 70% presented with unstable angina and 52% had single vessel disease. Of the lesions treated, 96% were de novo. Adjunctive PTCA after DCA was performed in 90% of cases at the discretion of the investigator to maximize luminal diameter. The GTO DCA device was used in 90% of cases. Procedural success (residual stenosis <50% without major complications) was 94%. Stents were placed in 12% of patients. The only complications were three non-Q wave MIs. Mean reference vessel diameter increased from 2.49 mm pre-procedure to 2.57 mm after DCA and 2.61 post-procedure; mean MLD increased from 0.76 mm to 2.03 mm to 2.31 mm; and mean stenosis decreased from 70% to 21% post DCA and to 11% post procedure. At six months follow-up, 18.0% of target lesions required revascularization. Total revascularization, including non-target vessels, was 32%. These results suggest that DCA has a high procedural success rate and a low target lesion revascularization rate in intermediate sized vessels.

Renal haemangioma in a dog.

A three-and-a-half-year-old, spayed female, crossbred dog was presented with chronic haematuria. Diagnostic tests included abdominal ultrasonography, intravenous urography, cystoscopy and nephrectomy. Renal haemangioma was identified as the cause of the haematuria, which resolved postoperatively. A subcutaneous mass developed one month after the nephrectomy, which was diagnosed by biopsy as a cutaneous cavernous haemangioma. No other masses were reported one year later.

Electrohydraulic and extracorporeal shock-wave lithotripsy.

The literal meaning of lithotripsy is the "act of breaking stones." There are two forms of lithotripsy available for use in veterinary medicine: electrohydraulic shock-wave lithotripsy (EHL) and extracorporeal shock-wave lithotripsy (ESWL). With EHL, a shock-wave is generated immediately adjacent to a urolith within the urinary bladder. In dogs, nephroliths or ureteroliths can be successfully treated with ESWL. With ESWL, the shock-waves are generated outside the body and directed toward the urolith.

Anastomotic complications in minimally invasive coronary bypass grafting.

BACKGROUND: Anterior wall myocardial revascularization through a left anterior minithoracotomy is an increasingly accepted procedure. Technical failure at the anastomotic site, promoting persistent or recurrent angina, is known to occur and may be underrecognized. This report summarizes the incidence of technical failure in an initial clinical experience and describes potential causes of early postoperative complications. METHODS: Between December 1995 and May 1996, 15 patients underwent left internal mammary artery-to-left anterior descending artery revascularization without extracorporeal circulation. The surgical indication was single-vessel coronary disease in all patients. We exposed the left anterior descending artery target site through a 10-cm left anterior fourth space thoracotomy. The fourth costal cartilage was resected and the left internal mammary artery was harvested under direct visualization. Two 4-0 polypropylene sutures snared in tourniquets proximal and distal to the anastomotic site were used to obtain a bloodless field and stabilization of the left anterior descending artery. RESULTS: All patients had procedures initially deemed successful based on disappearance of angina or postoperative transthoracic Doppler examination of the internal mammary artery 3 to 5 days postoperatively. However, 3 patients presented with recurrent angina at 2, 6, and 8 weeks. Angiography or direct visualization at operation demonstrated the technical complication (stenosis at the anastomotic site in 2 and snare injury in the native vessel in 1). Two patients required reoperation. CONCLUSIONS: Initial results with minimally invasive coronary bypass grafting have generated great enthusiasm worldwide, but there is no consensus on how the procedure should be performed. These results suggest that a nonstabilized anastomosis results in an unacceptable failure rate. Furthermore, sutures encircling the left anterior descending artery should not be used for vessel stabilization as injury of the artery may occur.

Use of ursodeoxycholic acids in a dog with chronic hepatitis: effects on serum hepatic tests and endogenous bile acid composition.

A dog with severe cholestasis secondary to chronic hepatitis was treated with ursodeoxycholic acid (UDCA) PO. After 2 weeks of daily treatment, the dog was more active and had an improved appetite. Monthly serum biochemical determinations and analysis of individual bile acid profiles documented improvement in hepatobiliary tests and a marked reduction in the concentrations of potentially hepatotoxic endogenous bile acids. These effects were maintained for approximately 6 months. The findings in this dog are similar to those reported for human patients treated with UDCA and provide preliminary evidence in support of its continued evaluation in the treatment of cholestatic liver disease in the dog.

Effect of acute induced metabolic alkalosis on the acid/base responses to sprint exercise of six racing greyhounds.

To investigate the effect of acute induced metabolic alkalosis on the haematological, biochemical and metabolic responses to sprint exercise, six greyhound dogs with previously placed carotid arterial catheters were raced four times over a distance of 400 metres. Each dog was raced twice after receiving oral sodium bicarbonate solution (NaHCO3) (400 mg kg-1) or lactated Ringer's solution (LRS). Before, and for intervals of up to one hour after, the exercise arterial blood samples were collected for the measurement of blood gases, packed cell volume, total protein, serum biochemistry and plasma lactate. The time to complete the 400 metre sprint ranged from 32.7 seconds to 36.9 seconds. There was no significant difference in racing times between the dogs treated with NaHCO3 and LRS, and there was no significant difference between the plasma lactate measurements after the treatments with NaHCO3 or LRS. Serum chloride concentrations were significantly lower after NaHCO3 than after LRS, and there was a trend towards a lower serum potassium concentration after NaHCO3 treatment. Plasma lactate concentrations showed a similar increase and time course of disappearance after both LRS and NaHCO3 treatments. There were significant changes in all the parameters measured after the exercise, but there were large variations between individual dogs and between races when the dogs were receiving the same treatment.

The role of Mycoplasma species and Ureaplasma species in feline lower urinary tract disease.

The cause of feline lower urinary tract disease (FLUTD) is frequently difficult to determine and may be multifactorial. A controlled cohort study was performed to examine the role of Mycoplasma species and Ureaplasma species in FLUTD. Based on culture and serologic criteria, these microorganisms did not appear to be involved in the group of cats studied. At this time, there is no evidence to implicate Mycoplasma species and Ureaplasma species in FLUTD.

Hemolytic uremic syndrome in dogs.

A disease syndrome similar to the hemolytic uremic syndrome of people is described in three dogs with acute renal failure. In each dog, hemorrhagic gastroenteritis preceded the onset of anuric acute renal failure. Evidence of microangiopathic hemolytic anemia (schizocytes, thrombocytopenia, and increased concentrations of fibrin split products) was present in the three dogs. Serum chemistry results showed increased concentrations of blood urea nitrogen, creatinine, and phosphorus. Ultrasound examination performed in one dog revealed increased echogenicity of the renal cortices. Treatment for anuric acute renal failure using a continuous dopamine and furosemide infusion established urine production in one of three dogs. Microscopic examination of tissue from the two dogs that underwent necropsy showed occlusion of the renal vasculature by fibrin thrombi consistent with microangiopathic arteriolar thrombosis. The pathophysiology and current knowledge of human hemolytic uremic syndrome is compared with hemolytic uremic syndrome in these dogs.

Dystrophin deficiency causes lethal muscle hypertrophy in cats.

Two 5-month-old male Domestic Shorthair littermates showed general skeletal muscle hypertrophy, multifocal submucosal lingual calcification with lingual enlargement, and excessive salivation. Both cats had a reduced level of activity, walked with a stiff gait, and tended to "bunny hop" when they ran. These clinical features were similar to those of previously reported dystrophin-deficient cats. Using multiple dystrophin antibodies, we found that the cats described in this report also showed marked dystrophin deficiency. The histopathology was remarkable for hypertrophy and splitting of fibers, and progressive accumulation of calcium deposits within the muscle. There was little or no endomysial fibrosis at 2 years of age. The natural history of dystrophin-deficiency in cats has not been described: both previous cats had been euthanized at 2 years of age prior to experiencing any life-threatening problems. At 6 months of age, one of the new cats developed megaesophagus because of severe progressive hypertrophy of the diaphragmatic muscles. The diaphragm completely occluded the esophagus, and the cat was euthanized for humane reasons. The second cat remained in good condition until age 18 months when it developed acute renal failure attributed to severe prolonged dehydration and hyperosmolality. The cat recovered after receiving supportive treatment but was unable to maintain fluid homeostasis. The insufficient water intake was attributed to glossal hypertrophy and dysfunction. At age 2 years, the cat received regular subcutaneous injections of low-sodium fluids to maintain proper hydration. The clinical consequence of dystrophin deficiency in cats is lethal muscle hypertrophy. We have called the feline disease "hypertrophic feline muscular dystrophy" (HFMD).

Serotype, hemolysin production, and adherence characteristics of strains of Escherichia coli causing urinary tract infection in dogs.

Virulence factors were studied in 82 strains of Escherichia coli isolated from the urine of dogs with urinary tract infections. The most frequently expressed O antigens were 2, 4, 6, 25, and 22/83. Most strains were K nontypeable. Mannose-sensitive hemagglutination (MSH) with canine erythrocytes was observed in 71 strains and mannose-resistant hemagglutination (MRH) was observed in 32 strains. Strains that caused MSH of erythrocytes from dogs also caused MSH of erythrocytes from guinea pigs. Most strains that caused MRH of human A1P1 erythrocytes also reacted with erythrocytes of dogs. Of 22 strains (27%) that agglutinated human A1P1 erythrocytes, but not A1p erythrocytes, 17 (77%) had specificity for globo A, but did not react with the galactose alpha 1----4galactose beta disaccharide receptor. The remaining 5 strains and 2 others that simultaneously expressed an X adhesin agglutinated galactose alpha 1----4galactose beta-coated latex beads. Bacterial adherence to canine uroepithelial cells from the bladder was most often observed in strains expressing MSH, less often observed in strains expressing MRH, and least often observed in strains that failed to induce hemagglutination. Adherence of MSH strains to canine uroepithelial cells was inhibited by alpha-methyl-D-mannoside. As a group, MRH strains expressing globo-A- and galactose alpha 1----4galactose beta-specific adhesins did not have strong adherence. Strains of E coli isolated from dogs with urinary tract infections most commonly expressed type-1 fimbriae, and the main mechanism of in vitro adherence to canine uroepithelial cells involved a mannose-sensitive mechanism. Overrepresentation of globo-A-specific adhesins did not appear to be related to adherence of canine uroepithelial cells.

Accordion effect in tortuous right coronary arteries during percutaneous transluminal coronary angioplasty.

Coronary spasm and intimal dissection are well-known complications of coronary angioplasty with potentially serious consequences. Their treatments are different and need to be instituted quickly to prevent vessel closure. We report two cases of mechanical deformation caused by the angioplasty hardware masquerading as dissection or spasm during coronary angioplasty of tortuous native right coronary arteries.

Survival of feline mycoplasmas in urine.

The effects of length of incubation and urine osmolality on the survival of feline mycoplasmas and ureaplasmas and representative gram-positive and gram-negative bacteria in synthetic urine which approximated the osmolality of normal cat urine were investigated. Both Escherichia coli and Staphylococcus aureus withstood the effects of increasing osmotic pressure. In the most concentrated urine, significant decreases (P less than 0.001) in CFU were observed for E. coli at exposure times of 30 min and longer. S. aureus was not affected by longer exposure or increased osmotic strength. Both Mycoplasma felis and Mycoplasma gateae were affected adversely by longer exposure times and high osmotic strength (P less than 0.001). A Ureaplasma sp. was not adversely affected except at very high (greater than or equal to 2,980 mosM) osmotic strengths or after prolonged incubation (120 min) at relatively high (1,976 mosM) osmotic strengths (P less than 0.001). The failure of both M. felis and M. gateae to survive under osmotic conditions present in normal feline urine suggests that it is unlikely that these mycoplasmas are involved in urinary disorders in cats.

Chemical studies of high-Km aldehyde dehydrogenase from rat liver mitochondria.

Studies of pH-dependent kinetics implicate two ionizable groups in the dehydrogenase and esterase reactions catalysed by high-Km aldehyde dehydrogenase from rat liver mitochondria. Sensitized photooxidation completely arrests the bifunctional activities of the dehydrogenase. Carboxamidomethylation abolishes the dehydrogenase activity, whereas acetimidination eliminates the esterase activity. These results suggest that histidine (pKa near 6) and cysteine (pKa near 10) are likely the catalytic residues for the dehydrogenase activity, while the esterase activity is functionally related to histidine (pKa near 7) and a residue with the pKa value of 10-11. The two residues, a carboxyl group and an arginine, that discriminate between NAD+ and NADP+ are present at the coenzyme binding site of the mitochondrial high-Km aldehyde dehydrogenase from rat liver.

The interaction of xylanases with commercial pulps.

When purified xylanases from Trichoderma harzianum E58 or from a clone of Bacillus circulans were incubated with various low-yield wood pulps, little of the original enzyme activity could be detected in the filtrate at the end of the reaction. Partial bleaching of the pulps prior to enzymatic treatment generally resulted in an increased recovery of the xylanase activity. It appears that both nonspecific adsorption and soluble inhibitors may be responsible for the loss of much of the xylanase activity. However, xylanases from Aureobasidium pullulans and Schizophyllum commune were not as inhibited by the pulps, and the activity of the latter enzyme actually increased after incubation with several high-yield pulps. Although a lignin preparation from spent sulfite liquor at a concentration of 0.06 mg/mL could inhibit the xylanase activity of T. harzianum and B. circulans by 65% and 50%, respectively, xylanases from Thermoascus aurantiacus, S. commune, and A. pullulans were activated at similar lignin concentrations. At higher concentrations these latter xylanases were also inhibited. Water-soluble lignins extracted from a variety of pulps and used at a lignin concentration of 2.5 mug/mL resulted in inhibition of more than 65% of the original activity of the xylanase from T. harzianum. Kinetic studies showed that lignin from spent sulfite liquor resulted in noncompetitive inhibition of this enzyme.