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Biomedical subjects

P R Fox

Publications and source records attributed to P R Fox.

34 records · Page 2Linked to original sources
PubMed1984

Hypertropic cardiomyopathy and hyperthyroidism in the cat.

In a 21/2-year period, hypertrophic cardiomyopathy was found at necropsy of 23 cats that died (13 cats) or were euthanatized (10) because of problems associated with hyperthyroidism. Of these, 4 (17%) also had evidence of cardiac failure (pulmonary edema or pleural effusion). The mean body weight of the cats with hyperthyroidism and hypertrophic cardiomyopathy was significantly less (P less than 0.001) than that of clinically normal cats and cats with primary cardiomyopathy (congestive or restrictive) or excessive moderator band cardiomyopathy. In addition, the ratio of heart weight to body weight was significantly greater (P less than 0.001) in the 23 hyperthyroid cats than in the normal cats and cats with primary cardiomyopathy. Twenty (87%) of the cats had symmetric hypertrophy of the ventricular septum and left ventricular free wall, whereas the remaining 3 cats had disproportionate thickening of the ventricular septum, compared with the free wall, similar to what is found in cats with asymmetric hypertrophic cardiomyopathy. Histologic cardiac abnormalities included large, hyperchromatic nuclei, interstitial fibrosis, endocardial fibroplasia, fibrosis of the atrioventricular node, and marked disorganization of cardiac muscle cells. The study showed that hypertrophic cardiomyopathy develops in most hyperthyroid cats, some of which also develop congestive heart failure. Although the signs of heart disease in primary myocardial disease and thyrotoxic disease are similar, the characteristic signalment and clinical signs of hyperthyroidism should lead one to suspect the association of hypertrophic cardiomyopathy with the hyperthyroidism.

Animals↗
PubMed1984

Thread and sewing needles as gastrointestinal foreign bodies in the cat: a review of 64 cases.

Sixty-four cases of gastrointestinal linear foreign body in the cat were reviewed. Most of the cats were less than 4 years old. The most common clinical signs were persistent vomiting, partial to complete anorexia, and depression. Abdominal palpation by itself was rarely diagnostic. Diagnosis in approximately 75% of the cases was possible, however, by using a combination of oral examination and abdominal palpation. Survey radiography contributed to the diagnosis in 86% of the cases in which it was used, based on evidence of bowel plication, presence of tapered, enteric gas bubbles, gathering of the small intestine, peritonitis, intestinal needles, or bowel obstruction. Surgery (gastrotomy and multiple enterotomies) was necessary in 96.9% of the cases, and most of the cats so treated did well (83.9%). Approximately 50% of the cats with linear foreign body-induced bowel lacerations recovered.

Animals↗
PubMed1983

Feline hyperthyroidism: pretreatment clinical and laboratory evaluation of 131 cases.

Hyperthyroidism was diagnosed in 131 cats during a 3 1/2-year period. The cats ranged in age from 6 to 20 years; there was no breed or sex predilection. The most frequent clinical signs included weight loss, polyphagia, increased activity, polydipsia, polyuria, and vomiting. Common serum biochemical abnormalities included high values for alkaline phosphatase activity (75%), lactate dehydrogenase activity (66%), aspartate transaminase activity (66%), and alanine transaminase activity (54%). Electrocardiographic changes included tachycardia (greater than or equal to 240 beats/min) and increased R-wave amplitude in lead II (greater than or equal to 0.9 mV) in 66% and 29% of the 131 cats, respectively. Thoracic radiography in 82 cats revealed cardiomegaly in 40 (49%) of these cats; 16 cats with congestive heart failure also had pulmonary edema or pleural effusion. In 5 cats with markedly increased fecal volume, mean 48-hour fecal fat content was significantly greater than normal, with daily fat excretion 2 to 15 times the upper limit of normal. Base-line serum thyroxine concentrations were increased above normal range in all cats, whereas triiodothyronine concentrations were increased in 127 (97%) of the 131 cats. In 11 cats tested, mean thyroxine concentration did not increase significantly after thyroid-stimulating hormone administration. Mean 24-hour percentage of thyroid radioiodine uptake in 32 hyperthyroid cats was significantly higher (39.1%) than normal (9.2%). Thyroid scans, performed on 126 cats, showed enlargement and increased radionuclide accumulation in 1 thyroid lobe in 36 (29%) and both lobes in 90 (71%) of the cats.

Adenocarcinoma↗
PubMed1982

Excessive moderator bands in the left ventricle of 21 cats.

Excessive numbers of moderator bands bridging the left ventricular septum and free wall and entangling papillary muscles were associated with heart failure and death in 21 cats. Clinical findings included dyspnea, anorexia, hypothermia, cardiomegaly, pleural effusion, plumonary edema, heart murmurs, gallop rhythm, electrocardiographic abnormalities (especially conduction disturbances), increased left ventricular end-diastolic pressure, angiocardiographic evidence of left ventricular restriction, and aortic thromboembolism. Pathologic changes included a morphologically distinct network of abnormal numbers of moderator bands in the left ventricle, left ventricular hypertrophy (younger cats--mean age, 4 years) or dilatation (older cats--mean age, 8.7 years), left atrial enlargement and hypertrophy, and pulmonary edema with heart failure cells in the alveoli. Heart weights of affected cats were significantly less than those of cats with congestive, hypertrophic, and restrictive cardiomyopathy (endocardial fibrosis), but were not significantly less than heart weights of clinically normal cats. Pathologic changes were characteristic of the syndrome grossly and histologically, but clinical findings were not clearly definable.

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PubMedDate not supplied

Molecular screening by polymerase chain reaction detects panleukopenia virus DNA in formalin-fixed hearts from cats with idiopathic cardiomyopathy and myocarditis.

Viral myocarditis has been suggested as an etiology for cardiomyopathy in several mammalian species. Myocarditis and idiopathic cardiomyopathy have been reported in the domestic cat, although a viral etiology has not been demonstrated. Because of the continuing interest in the potential relationship between viral myocarditis and cardiomyopathy, we evaluated hearts from cats with spontaneous, idiopathic cardiomyopathy for viral genomic material within myocytes by polymerase chain reaction, and for the presence of myocarditis by light microscopy. Thirty-one (31) formalin-fixed hearts from domestic cats who died of idiopathic cardiomyopathy were randomly selected from pathology archives. Seventeen (17) formalin-fixed hearts from healthy cats were similarly selected as normal controls. The polymerase chain reaction (PCR) was used to evaluate myocardial tissue for the presence of viral genome from feline panleukopenia virus, herpes virus, calici virus, and corona virus. Hearts were examined using light microscopy for histologic evidence of myocarditis according to the Dallas criteria. Panleukopenia virus was identified by PCR in 10 of 31 cats with cardiomyopathy but in none of the controls. Neither cardiomyopathic or control cats tested positive by PCR for herpes virus, calici virus, and corona virus. Myocarditis was detected by histologic examination in 18 of 31 cardiomyopathic cats and in none of 17 control cats. Myocarditis and or feline panleukopenia virus genome was detected in felines with idiopathic hypertrophic, dilated, and restrictive cardiomyopathy, suggesting a possible role of viral infection and inflammation in the pathogenesis of cardiomyopathy in this species.

Animals↗
PubMedDate not supplied

Ventricular arrhythmias in dogs undergoing splenectomy: a prospective study.

Fifty dogs undergoing splenectomy for splenic masses (n = 40), torsion of the splenic pedicle (n = 5), and immune-mediated disease (n = 5) were evaluated preoperatively and and postoperatively for ventricular arrhythmias and the relationship between ventricular arrhythmia splenic disease. The ability of 1-minute electrocardiograms recorded every 6 hours (ECGs/q6hr) to detect ventricular arrhythmia was compared with continuous 48-hour Holter monitoring. Based on continuous Holter monitoring, splenectomized dogs had a high incidence (22 of 50) of rapid ventricular tachycardia. The incidence of rapid ventricular tachycardia was significantly higher in dogs with ruptured splenic masses (16 of 23) than without rupture (1 of 17) (P < .001). When the results of ECG/q6hr were compared with the results of continuous Holter monitoring ECG/q6hr was normal in 29% (4 of 14) of dogs with rapid ventricular tachycardia at > 3,000 ventricular extrasystoles (VE)/hr; 50% (4 of 8) of dogs with rapid ventricular tachycardia at 1,000 to 3,000 VE/hr and 100% (6 of 6) of dogs with 10 to 300 VE/hr without rapid ventricular tachycardia. Although dogs undergoing splenectomy had a high incidence of ventricular arrhythmias, one-minute ECGs/q6h were unreliable for detection of ventricular arrhythmias even when high-frequency extrasystoles occurred.

Animals↗
PubMedDate not supplied

Plasma taurine concentrations and M-mode echocardiographic measures in healthy cats and in cats with dilated cardiomyopathy.

M-mode echocardiography was completed and plasma taurine concentrations were determined in 79 healthy cats and 77 cats with dilated cardiomyopathy (DCM). In healthy cats, a relationship was not observed between plasma taurine concentrations and any M-mode echocardiographic measurement. End-systolic and end-diastolic cardiac chamber dimensions were larger; wall thickness measures were smaller; and calculations of fractional shortening were less in cats with DCM than in healthy cats. Plasma taurine concentrations less than 30 nmol/mL were detected in 7/79 healthy cats and in 52/77 cats with DCM. Of the 52 cats with DCM and an initial plasma taurine concentration less than 30 nmol/mL, 23 died or were euthanized during the first post-treatment week, 7 were lost to further study, and 22 improved after taurine supplementation. Of the 25 cats with DCM and an initial plasma taurine concentration greater than or equal to 30 nmol/mL, 9 died or were euthanatized during the first post-treatment week, and 9 were lost to further study. Two cats did not improve, of which one died and one was euthanatized 4 to 8 weeks after initiation of taurine supplementation. Five cats with a plasma taurine concentration greater than or equal to 30 nmol/mL improved after taurine supplementation. Myocardial function subsequently deteriorated in three of these cats. Two of the three cats had signs of congestive heart failure redevelop.

Animals↗
PubMedDate not supplied

Doxorubicin-induced cardiotoxicosis. Clinical features in 32 dogs.

Clinical cardiac abnormalities developed in 32 of 175 dogs that had various malignancies and were treated with doxorubicin: 31 dogs had electrocardiographic abnormalities including arrhythmias and nonspecific alterations in the R wave, ST segment, or QRS duration and 7 dogs had congestive heart failure. All seven dogs that had congestive heart failure died within 90 days. At necropsy, 13 of 32 affected dogs had noninflammatory myocardial degeneration, myocytolysis, vacuolation, and/or fibrosis and there was intramural coronary arteriosclerosis in all 13. Five dogs with lymphosarcoma were in complete clinical remission when they died of doxorubicin-induced cardiomyopathy, but the overall survival times of the lymphosarcoma subset was nevertheless longer than in previous studies. The clinical use of doxorubicin in the dog can cause cardiotoxicosis but the therapeutic benefit appears to outweigh risks in most dogs.

Animals↗
PubMedDate not supplied

Plasma taurine concentrations in normal dogs and in dogs with heart disease.

Plasma taurine concentrations were determined in 76 dogs with dilated cardiomyopathy (DCM), 28 dogs with acquired valvular disease (AVD), and 47 normal (control) dogs. The data were collected at 2 referral centers, The Animal Medical Center, New York, NY (AMC), and the University of California, Davis (UCD), and the studies were conducted independently. Different anticoagulants (sodium citrate at AMC and lithium heparin at UCD) were used to collect the plasma samples. Paired analysis of samples showed a significant difference in plasma taurine concentrations, depending on the anticoagulant used. Consequently, results from each clinic were analyzed separately. Plasma taurine concentrations were significantly higher in dogs with AVD (median, 133 nmol/mL; range, 25 to 229 nmol/mL) than in control dogs (median, 63 nmol/mL; range 44 to 224 nmol/mL) and dogs with DCM (median, 72 nmol/mL; range, 1 to 247 nmol/mL) at AMC (P < .001). The number of dogs with AVD at UCD was too small to draw meaningful conclusions. At UCD, the median plasma taurine concentration was 98 nmol/mL (range, 28-169 nmol/mL) in dogs with AVD, 75 nmol/mL (range, 0.1-184 nmol/mL) in dogs with DCM, and 88 nmol/mL (range 52-180 nmol/mL) in control dogs. There were no significant differences in plasma taurine concentrations between dogs with DCM and the control dogs at either hospital. Congestive heart failure and administration of cardiac medication had no significant effect on plasma taurine concentrations. Plasma taurine concentration was low (< 25 nmol/mL) in 17% (13/76) of the dogs with DCM. Seven of the 13 dogs with low plasma taurine concentrations were Cocker Spaniels or Golden Retrievers.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Electrocardiographic and radiographic changes in cats with hyperthyroidism: comparison of populations evaluated during 1992-1993 vs. 1979-1982.

Cardiovascular manifestations of feline hyperthyroidism were compared in two populations of cats diagnosed at The Animal Medical Center from 1992 to 1993 (n=202) and 1979 to 1982 (n = 131). The prevalence of sinus tachycardia and increased R-wave voltage in lead II were both lower in the 1993 population compared with the 1982 population (p less than 0.001). A low frequency of atrial and ventricular arrhythmias and intraventricular conduction abnormalities were recorded in both populations. No significant differences between populations were recorded in the number of cats with mild, moderate, and severe cardiomegaly seen on thoracic radiographs. The percentage of cats in which radiographs were deemed clinically necessary based upon history and clinical examination was 25% of the 1993 population, compared with 63% of the 1982 population. The number of cats with radiographic evidence of congestive heart failure was 8% in 1993 compared with 20% in 1982, although this difference was not statistically significant. In conclusion, the incidence and severity of certain thyrotoxic cardiovascular manifestations were reduced in cats diagnosed between 1992 and 1993 compared with those diagnosed between 1979 and 1982.

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