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Biomedical subjects

R R King

Publications and source records attributed to R R King.

At least 19 recordsLinked to original sources
PubMed1994

Induction of serum tumor necrosis factor-alpha and interleukin-6 activity by liposome-encapsulated muramyl tripeptide-phosphatidylethanolamine (L-MTP-PE) in normal cats.

Tumor necrosis factor-alpha (TNF alpha) and interleukin-6 (IL-6) are products of activated monocytes/macrophages with anti-tumor activity. Liposome-encapsulated muramyl tripeptide-phosphatidylethanolamine (L-MTP-PE) is a potent monocyte/macrophage activator. Sera from cats after intravenous L-MTP-PE administration showed TNF alpha activity using a WEHI-164 cell cytotoxicity assay and IL-6 activity using an IL-6 dependent mouse 7TD1 hybridoma cell proliferation assay. Serum TNF alpha activity peaked at 2 hours after L-MTP-PE administration. Significant differences from lipid-equivalent controls were observed at 2 and 3 hours (P < 0.05). Neutralization of serum TNF alpha activity was accomplished with serial dilutions of rhTNF alpha monoclonal antibody. Serum IL-6 activity peaked at 3 hours after L-MTP-PE administration. Significant differences from lipid-equivalent controls were observed at 2, 3, and 4 hours (P < 0.05). Neutralization of serum IL-6 activity was not achieved with goat anti-rhIL-6 polyclonal antibody. Intravenous L-MTP-PE, but not lipid-equivalent, induces serum TNF alpha and IL-6 activity in normal cats.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1991

Cytotoxic tumor necrosis factor activity produced by equine alveolar macrophages: preliminary characterization.

Blood monocytes and alveolar macrophages (AM) were harvested from foals (aged 46 days to 6 months) and cultured in either medium alone or medium containing 10 micrograms/ml bacterial lipopolysaccharide (LPS). After 24 h, culture supernates were collected and analyzed for cytotoxic activity on sensitized L929 cells. Both monocytes and AM that had been treated with LPS produced significantly more cytotoxic activity than the same cell type exposed to medium lacking LPS. LPS-treated macrophages secreted significantly more cytotoxic activity (120 +/- 17.8 U/ml) than did LPS-treated monocytes (47.3 +/- 17.0 U/ml); however, constitutive production of cytotoxin by monocytes was higher (16.7 +/- 4.1 versus 1.2 +/- 1.2 U/ml). The identification of the cytotoxin as tumor necrosis factor (TNF) was strongly suggested by its reactivity with a rabbit antiserum directed against the N-terminal 15 amino acids of human TNF. TNF secretion by AM increased in a dose-dependent manner between LPS concentrations of 0.0001 and 1 microgram/ml, then leveled off. Most of the cytotoxic TNF activity produced by AM was secreted within the first 8 h after initial contact with LPS. Macrophage supernatant TNF was stable over a pH range of 6-11, but lost activity when kept at a pH less than 6. Equine TNF also was destroyed by exposure for 1 h to temperatures more than 60 degrees C. TNF bioactivity was recovered as a single peak after crude macrophage supernate was subjected to analysis by either anion exchange or gel filtration chromatography (molecular weight approximately 56,000).

Animals↗
PubMed1991

Use of pulsed-wave Doppler echocardiography to determine aortic and pulmonary velocity and flow variables in clinically normal dogs.

Transcutaneous pulsed-wave Doppler echocardiography was used to obtain velocity signals from the aortic and pulmonary roots of clinically normal adult dogs tranquilized with acepromazine. Doppler-derived variables included peak ejection velocity, ejection time, and velocity-time integral. The cross-sectional areas of the left and right ventricular outflow tracts were estimated from diameters of the respective orifices measured from two-dimensional echocardiographic images. These data were used to calculate stroke volume and cardiac output for each ventricle. Linear, single variable regressions of ejection time, velocity-time integral, and peak velocity with body weight showed no significant correlations. Significant correlations existed between body weight and estimated left and right ventricular stroke volume and cardiac output. A close correspondence existed between pulmonary and aortic determinations of velocity-time integral, stroke volume, and cardiac output. These results provide an initial framework for interpretation of clinical data by veterinary cardiologists.

Animals↗
PubMed1989

Pulmonic stenosis and right-to-left atrial shunt in three dogs.

Using cardiac catheterization, pulmonic stenosis and right-to-left atrial shunt were diagnosed in 3 young dogs that were evaluated because of weakness, cyanosis, and polycythemia. Injection of contrast material into the caudal vena cava or crossing the atrial septal defect with the catheter tip from the right atrium into the left atrium confirmed the diagnosis. Tetralogy of Fallot, with right-to-left shunt through a ventricular septal defect, is a more common congenital malformation associated with the aforementioned clinical signs. Differentiation between the 2 defects is important, because surgical decompression of the right ventricle will lead to reduction of right atrial pressure and diminishment of the shunt.

Animals↗
PubMed1988

Medical and surgical management of multiple organ infarctions secondary to bacterial endocarditis in a dog.

A 6-year-old male Doberman Pinscher developed multiple organ infarctions secondary to vegetative endocarditis. Clinical signs included fever, nystagmus, head-tilt, inappetence, dehydration, hematuria, and dysuria. The dog was azotemic and anemic and had a high WBC count and high liver enzyme activities. Disseminated intravascular coagulation was diagnosed on the basis of thrombocytopenia and prolonged activated clotting times. Vegetative mitral valvular lesions were evident on M-mode echocardiography. The dog underwent diuresis with physiologic saline solution and was treated parenterally with antibacterial and anticoagulant agents. Surgery was performed to remove an infarcted kidney and an infarcted spleen and to relieve urethral obstruction caused by a large blood clot. Gram-positive cocci were noticed in the biopsy specimens. Mortality associated with organ infarctions secondary to bacterial endocarditis is high, and combined medical and surgical therapy is rarely reported. This dog survived and was alive 38 months after surgery.

Animals↗
PubMed1988

Echocardiographic evaluation of cardiac tamponade in dogs before and after pericardiocentesis: four cases (1984-1986).

The echocardiographic (M-mode and 2-dimensional) features (before and after pericardiocentesis) of 4 dogs with pericardial effusion and clinical evidence of cardiac tamponade were reviewed. M-Mode echocardiography revealed pericardial effusion, with exaggerated swinging motion of the heart and abnormal septal motion in all 4 dogs. In each case, 2-dimensional echocardiography demonstrated right ventricular diastolic free-wall collapse. Three dogs had right atrial diastolic collapse as well. Clinical signs improved, and right ventricular and right atrial diastolic collapse subsided after pericardiocentesis. Two-dimensional echocardiographic features of right atrial and ventricular collapse were used as indicators for determining the presence of cardiac tamponade.

Animals↗
PubMed1984

Exercise performance with added dead space in chronic airflow obstruction.

Individuals with chronic airflow obstruction (CAO) are thought to have limited exercise tolerance primarily because of impaired ventilatory mechanics. We studied the effects of added external dead space (DS) on exercise capacity [maximum O2 consumption (VO2max)], maximum exercise ventilation (VEmax), and blood gases (arterial PO2, PCO2, pH) in 22 patients with CAO [forced expired volume at 1 s (FEV1) = 0.96 +/- 0.41 liter]. Maximum exercise testing (Emax) was performed by incremental cycle ergometry. Patients exercised at base line (BL) and with DS (0.25 liter if FEV1 less than 0.8, and 0.50 liter if FEV1 greater than 0.8 liter), in random-order single-blind fashion. DS resulted in a 12.2% increase in VEmax (P less than 0.001); tidal volume increased (P less than 0.025) while respiratory frequency was unchanged. The VO2max and maximum CO2 production decreased (P less than 0.001) with DS. Arterial PCO2 at rest and at exhaustion increased with DS (P less than 0.001). The pH and arterial PO2 showed small declines at rest and at Emax. Thus, at the lower maximum work load achieved with DS, the patients ventilated more and tolerated a higher arterial PCO2 and a lower arterial PO2 and pH before stopping from dyspnea as compared with the BL exercise run. In contrast, the VO2max of nine normal control subjects was unaffected by the addition of DS. Although VEmax can be increased in CAO patients with DS, this increase is not sufficient to prevent further CO2 retention or a decrease in exercise capacity. We conclude that exercise performance is limited primarily by impaired ventilatory mechanics in CAO.

Aged↗
PubMed1984

Pulmonary profiling in exercise.

The role of the lungs during exercise, the effect of physical training on lung function, and the attributes of lung function that are important for superior athletic performance are discussed. Also considered is the role of exercise in two common lung disorders, asthma and chronic obstructive pulmonary disease.

Asthma, Exercise-Induced↗
PubMed1983

Effects of verapamil on pulmonary haemodynamics during hypoxaemia, at rest, and during exercise in patients with chronic obstructive pulmonary disease.

The haemodynamic effects of intravenous verapamil at rest, during hypoxaemia, and during progressive exercise were evaluated in 10 patients with chronic obstructive lung disease. Verapamil produced significant decreases in the peak heart rate and systemic blood pressure during exercise but exercise capacity and pulmonary gas exchange at exhaustion were unaffected. There were no significant changes in pulmonary artery pressure or total pulmonary vascular resistance during exercise or during the breathing of either air or a hypoxic gas mixture at rest. No clinically useful benefit was found with verapamil in the dosage used in this group of patients and the value of calcium antagonists in the treatment of patients with chronic obstructive lung disease requires further clarification.

Aged↗
PubMed1983

Gas chromatographic determination of maleic hydrazide residues in potato tubers.

A gas chromatographic (GC) method is described for the determination of maleic hydrazide residues in potato tubers by oxidation of maleic hydrazide with aqueous lead dioxide to 3,6-pyridazinedione in the presence of cyclopentadiene. The reaction product, a volatile Diels-Alder adduct, could be detected in potatoes at levels in excess of 0.05 ppm with an electron capture detector. Recoveries of maleic hydrazide (as the Diels-Alder adduct) from potatoes at fortification levels of 0.1 to 10 ppm averaged 91.7%.

Chromatography, Gas↗
PubMed1980

Analysis of potato glycoalkaloids by gas-liquid chromatography of alkaloid components.

A gas-liquid chromatographic (GLC) method has been developed for the analysis of potato glycoalkaloids by direct determination of the alkaloid components isolated by hydrolysis with 1N ethanolic HCl. Recoveries of solanidine from potato tubers and foliage fortified with solanine over a range approximately 0.5 to 5 times the glycoalkaloid originally present averaged greater than 95%, and the lower limit of sensitivity was 0.25 mg/100 g using a nitrogen--phosphorus detector. A means of distinguishing solanidine and demissidine by formation of their respective 3 beta-trifluoroacetates with trifluoroacetic anhydride (TFAA) is demonstrated.

Alkaloids↗
PubMed1978

Synthesis and biological activity of 15-arylprostaglandins.

Prostaglandin analogues in which the alkyl chain attached to C-15 in the natural compounds is replaced by an aryl group have been synthesised. Some of these compounds are potent luteolytic agents and comparisons are drawn between this series and 16-aryloxyprostaglandins.

Animals↗
PubMed1977

The preparation of carbohydrate-protein conjugates: cyanuric trichloride coupling of 2-aminoethyl glycosides, and mixed-anhydride coupling of 8-carboxyoctyl glycosides to bovine serum albumin.

Preparation of the following glycosides is described: 2-aminoethyl beta-D-glycosides of (A) 2-acetamido-3,4,6-trio-O-acetyl-2-deoxy-D-glucopyranose, (B) 2-acetamido-4-O-(2-acetamido-3,4,6-trio-O-acetyl-2-deoxy-beta-D-glucopyranosyl)-3,6-di-O-acetyl-2-deoxy-beta-D-glucopyranose (N,N'-diacetylchitobiose pentaacetate), (C) 4-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-2,3,6-trio-O-acetyl-beta-D-glucopyranose (cellobiose heptaacetate); 8-carboxyoctyl glycosides of (D) cellobiose, and (E) N,N'-diacetylchitobiose. Conjugates were prepared from (A), (B), and (C) by coupling to bovine serum albumin by cyanuric trichloride and subsequent deacetylation; (D) and (E) were coupled to bovine serum albumin by the mixed-anhydride reaction. Conjugates (A) and (B) were insoluble; conjugates (C), (D), and (E) functioned as artificial antigens and gave rise to precipitating antibodies in rabbits. Specificities of the antisera were determined by inhibition studies.

Antibodies↗
PubMed1976

Milk transfer of pyrrolizidine alkoloids in cattle.

A study was conducted to determine if pyrrolizidine alkaloids from Senecio jacobaea (tansy ragwort) are passed into milk of lactating cows. Four cows were given dried tansy ragwort via rumen cannula at a dosage of 10 g/kg/day for 2 weeks. Chemical assay of pyrrolizidine alkaloid content in the dried plants averaged 0.16% by weight. By use of thin-layer chromatography, 5 alkaloids were isolated from the plant materials. The only alkaloid isolated from the milk was jacoline. Condition of the cows and nursing calves was monitored via measurement of blood leukocyte count, and serum protein, albumin, and globulin content. Sorbitol dehydrogenase values and liver biopsy specimens were used to assess liver function. In the cows, marked changes were observed in blood leukocyte count, sorbitol dehydrogenase values, and liver biopsy findings. No changes of any type were observed in the calves. Pyrrolizidine alkaloid content of the milk ranged from 9.4 to 16.7 mug/100 ml of milk.

Animals↗
PubMed1976

The 13C-N.M.R. spectra of disaccharides of D-glucose, D-galactose, and L-rhamnose as models for immunological polysaccharides.

Complete assignments of the 13C-n.m.r. spectra of disaccharides having beta-glycosidic linkages are presented and discussed. The disaccharides of D-glucose, D-galactose, L-rhamnose, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-2-deoxy-D-galactose are model compounds for 13C-n.m.r. studies of immunological polysaccharides. Changing the nature of the reducing glucopyranose rings (D-glucose to L-rhamnose) has no important influence on the chemical shifts of the carbons of the non-reducing glucopyranose ring (D-glucose). The converse is also true: the chemical shifts of the carbons of the reducing glucopyranose ring (L-rhamnose) are not noticeably affected by a change of the non-reducing unit (D-glucose to D-galactose or 2-acetamido-2-deoxy-D-glucose).

Disaccharides↗
PubMed1975

Self and mutual speech comprehension by deviant- and normal-speaking children.

This study was conducted to determine whether deviant-speaking children can understand their own speech productions when these productions are presented to them from an external source (tape recorder). Two groups of children with normal and deviant speech attempted to comprehend their own and one another's recorded repetitions of two matched lists of imperative sentences. Although there was a significant main effect for comprehension of high- and low-intelligibility sentences, a significant main effect for the groups' comprehension performances was not found. The results suggested that the deviant-speaking children were perceptually oriented to the standard code of the speech community rather than to their own deviant speech codes. Deficits in speech production are discussed in terms of a reduction theory of telegraphic speech. Deviant-speaking children may reduce complexity of speech output through the application of phonetic reduction rules.

Auditory Perception↗