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Biomedical subjects

J B Taylor

Publications and source records attributed to J B Taylor.

At least 73 records · Page 4Linked to original sources

Biochemical and haematological effects of a revised dosage schedule of phenylbutazone in horses.

Five pairs of matched horses were used to study the biochemical and haematological effects of a revised dosage schedule of phenylbutazone. One group of five horses received a phenylbutazone paste formulation daily for 12 days and a second group of five animals received a placebo preparation for a similar time. Some statistically significant differences were recorded from pretreatment levels in both groups of horses. These changes represented instability in baseline levels and could not be ascribed to phenylbutazone administration.

Animals↗

Patterns of Asian and non-Asian morbidity in hospitals.

On the basis of surname, 6418 Asians were identified out of a total of 109 187 deaths and discharges of Leicestershire residents who had been treated in hospitals in the Trent Regional Health Authority over two years. After linkage to Hospital Activity Analysis computerised records, hospital morbidity in Asians and non-Asians was compared. Asian patients in certain age groups were more likely than non-Asian patients to be diagnosed as having asthma; leukaemia; diabetes mellitus; blood, thyroid, and eye disorders; certain forms of heart disease; and spontaneous and other types of abortion (excluding therapeutic abortion). The well recognised excess of cases of tuberculosis among Asians was also confirmed. Conversely, for some age groups, Asians were less likely than non-Asians to fall into particular diagnostic categories. Exploring such apparent differences can serve as the basis for aetiological inquiry and service planning. The patient's name is now probably the most reliable indicator of Asian ethnic origin in health records.

Adolescent↗

Biochemical and haematological effects of phenylbutazone in horses.

Five matched pairs of horses were used to investigate the effects of phenylbutazone on a range of physiological, biochemical and haematological variables. The drug was given by mouth daily for 15 consecutive days at the manufacturer's recommended dose rates to one group of horses (Group A); the second group (Group B) received equivalent doses of a placebo. For some of the measured parameters, significant changes were recorded in both groups, indicating background instability. Significant decreases in serum total protein, albumin, plasma pH, viscosity and magnesium, and an increase in albumin: globulin ratio occurred in Group A, but not in Group B. These changes were, therefore, attributed to phenylbutazone or its metabolites. Toxicologically, the change in pH is probably unimportant but the decrease in protein concentration may have resulted from a protein losing enteropathy and/or from decreased synthesis in the liver. In one animal which received phenylbutazone, clinical signs of toxicity (lethargy, inappetence, oedema) were observed and evidence of hepatotoxicity and haematological changes were also noted in this horse. It is concluded that recommended dose rates of phenylbutazone should never be exceeded and that the period for which the highest dose (4.4 mg/kg body weight twice daily for four days) is administered should be reduced. In clinical cases, where phenylbutazone toxicity is suspected, measurement of serum or plasma protein concentration might provide an indication of the need to reduce dose levels or stop therapy.

Animals↗

Evidence that the Ya and Yc subunits of glutathione transferase B (ligandin) are the products of separate genes.

A study of the structure of glutathione transferase B (ligandin) has been made with a view to understanding the relationship between the structures of the subunits of which it is composed. It consists of a mixture of a homodimer (YaYa) and a heterodimer (YaYc) in which the monomers are defined by their apparent molecular weights, that of Ya being 22000 and Yc 25000. Soluble tryptic peptides from the native homodimer YaYa have been compared with those from an artificial homodimer YcYc produced by rehybridization of native YaYc. Approximately 10 peptides specific to YaYa, 12 specific to YcYc and 21 common to both have been detected. Some of the above peptides are derived from variants of the monomers themselves. YaYa and YcYc have two C termini which are the same in both dimers, namely phenylalanine and lysine. Also there are four cysteinyl peptides, of which three are common to YaYa and YcYc and one specific to each. These results suggest that Ya and Yc are derived from at least two different but related genes.

Chemical Phenomena↗

Pharmacokinetics of phenylbutazone and its metabolites in the horse.

Phenylbutazone was given orally to 2 groups of horses and the plasma levels of the drug and its 2 principal metabolites oxyphenbutazone and gamma-hydroxyphenylbutazone measured by high performance liquid chromatography. Animals in Group 1 received single oral doses in a range from 1.1 to 13.2 mg/kg and were sampled over the succeeding 24 h. Considerable individual variation was observed both in timing and magnitude of the plasma drug responses between horses, but 24 h after dosing a clear dose response relation was recorded. Group 2 horses were given the recommended therapeutic dosage regimen and sampled over 24 h periods twice weekly. After 4 days at 8.8 mg/kg in 2 divided doses mean peak plasma levels of phenylbutazone reached 24 micrograms/ml and showed evidence of cumulation. After 4 days at 4.4 micrograms/kg, peak plasma concentrations had fallen to 10 micrograms/ml and mean peak levels just failed to reach 4 micrograms/ml 3 days after reducing dosage to 2.2 mg/kg once daily. Plasma concentrations of oxyphenbutazone did not exceed 25 per cent of the parent drug and the gamma-hydroxy metabolite was only just detectable and never exceeded 1 microgram/ml.

Animals↗

Physiological hypertrophic subaortic stenosis and subendocardial infarction in a patient with a pheochromocytoma.

This report describes the occurrence of a pheochromocytoma in a middle-aged, black female with a 12-year history of hypertension, and a strong family history of hypertension. In this case, the pheochromocytoma was associated with a subendocardial myocardial infarction and congestive heart failure which occurred in the presence of large, dilated coronary arteries without intraluminal obstructions. The patient also had the murmur and echocardiographic and ventriculographic signs typical of idiopathic hypertrophic subaortic stenosis, which resolved following removal of the tumor and return of the blood pressure to normal. The authors believe this to represent a form of transient physiological hypertrophic subaortic stenosis secondary to a hypercatecholamine state.

Adrenal Gland Neoplasms↗

Studies on the absorption, distribution and elimination of 6-o-chlorophenyl-2,4-dihydro-2(N-methyl-piperazin-1-yl)-methylene-8-nitro-1H-imidazo[1,2-a] [1,4]benzodiazepin-1-one methanesulphonate in the male rat and rabbit.

The fate of a novel imidazo-benzodiazepine (I) was studied in male rats and rabbits using 14C and 3H-labelled I. In both species the compound was rapidly and widely absorbed after an oral dose of 5 mg/kg to give peak tissue and plasma levels after 1 hour in the rat and 4 hours in the rabbit. The highest concentrations of radioactivity were present in the liver (rat) and liver, kidney and subcutaneous fat (rabbit). Plasma levels of radioactivity fell to 3% of the maximum value in 24 hours in the rat but 48 hours were required for a similar fall in the rabbit. The main route of elimination of radioactivity was via the bile followed by excretion in the faeces. For the rat the rate of biliary elimination was 16.6% of the administered dose/hour; for the rabbit this rate was 5.6%/hour. Recovery of administered radioactivity during 0-24 hours for urine and faeces respectively was 4.8% and 69% for the rat and 23.2% and 10.9% for the rabbit. Up to 97% of the radioactivity administered to rats could be recovered in the excreta in the 7 days following dosing. Up to 90% of the dose administered to rabbits appeared in the excreta during 10 days. No unchanged (I) could be detected in the urine or bile. The radioactive metabolites were polar products, some of which were in the form of glucuronide conjugates.

Animals↗

Mineralization of the stylohyoid-stylomandibular ligament complex. A radiographic incidence study.

In this Veterans Administration-based study, 1,771 oral panoramic radiographs were reviewed to detect abnormalities in the styloid process, stylohyoid-stylomandibular ligament complex. Three hundred twenty-three (18.2 percent) of the radiographs revealed mineralization in these areas which varied from an apparent elongation of the styloid process to extensive involvement of the entire ligament complex with segmentation, nodularity, and the development of jointlike structures. Mineralization was unilateral in 12.4 percent of patients and was observed more commonly in patients 50 to 59 years of age. No relationship could be established between the extent of mineralization and increasing patient age. This study suggests that mineralization of the stylohyoid complex is not uncommon and probably only rarely causes symptoms.

Adult↗

Pharmacologically active sulfoximides: 5-hexyl-7-)S-methylsulfonimidoly) xanthone-2-carboxylic acid, a potent antiallergic agent.

The antiallergic activity of some xanthone derivatives containing a sulfoximide substitutent has been investigated. While 2-(S-methylsulfonimidoyl)xanthone itself was found to be inactive, a series of 7-(S-methylsulfonimidoly)-xanthone-2-carboxylic acids showed good levels of activity in the passive cutaneous anaphylaxis screen. N-Substituted sulfoximide derivatives were, without exception, less active than the corresponding unsubstituted compounds. The activity of the 7-(S-methylsulfonimidoyl)xanthone-2-carboxylic acids could be enhanced by the introduction of an alkyl or alkoxy substituent at C-5. As a result of these studies, 5-hexyl-7(S-methylsulfonimidoyl)xanthone-2-carboxylic acid has been selected for further investigation as an antipasthmatic agent.

Animals↗