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Biomedical subjects

T J Haley

Publications and source records attributed to T J Haley.

At least 19 recordsLinked to original sources

The mortality of men in the Rhondda Fach, 1950--1970.

A more detailed analysis of material from the 20-year follow-up of men in the Rhondda Fach confirms the similarity between the Standardised Mortality Ratios (SMRs) of miners and exminers with radiological categories 0, 1, 2, 3 and A (120.3, 116.5, 119.0, 115.7, and 120.1 respectively) as well as the difference between these SMRs and that of the non-moners (98.7). The specific death rates show a raised SMR for bronchitis and other respiratory diseases excluding pneumoconiosis for all categories including category 0, but little difference between those for category 0 and those for simple pneumoconiosis. The SMRs for ischaemic heart disease and other circulatory diseases for categories A, B and C combined are lower than those for simple pneumoconiosis and category 0 (84.2 and 85.0, compared with 109.8 and 121.8 for simple pneumoconiosis, and 117.5 and 114.6 for category 0). Fortunately the SMR for leukaemia is low. A comparison between the survival rates of men aged 55-64 in Leigh, Lancashire and those in the Rhondda Fach suggests that nonminers in the two areas have similar survival rates while the survival rates for category 0 and simple pneumoconiosis are lower in the Rhondda Fach.

Accidents

A pharmacokinetic study of pentachlorophenol poisoning and the effect of forced diuresis.

A pharmacokinetic study of an intentional pentachlorophenol ingestion by an elderly human has been undertaken. Information on the presence or absence of forced diuresis either continuously or for a short restricted period indicates that such treatment would materially reduce the body burden of pentachlorophenol. It is suggested that forced diuresis is the treatment of preference for such intoxication at this time.

Chlorophenols

Human poisoning with pentachlorophenol and its treatment.

A case of intentional intoxication with pentachlorophenol has been described. Salient features observed included pyrexia, diaphoresis, hyperkinesis, muscle twitching, tremors, epigastric tenderness, leg pain, tachypnea, and tachycardia. The patient's restlessness and agitation were controlled with phenytoin and phenobarbital. Forced diuresis with furosemide and mannitol resulted in a large increase in urinary excretion of pentachlorophenol. It is suggested that such therapy may be life saving in such intoxications.

Aged

Maleic hydrazide: should the Delaney amendment apply to its use?

The chemistry, metabolism, toxicology, mutagenicity, and carcinogenicity of maleic hydrazide have been reviewed. There is little doubt that this chemical is a mutagen and a carcinogen in cell cultures and animals, but no evidence is available on human carcinogenicity regardless of population exposure in manufacturing, agriculture, and the food chain (i.e., potato chips). An epidemiology survey should be conducted to ascertain possible human carcinogenicity in these populations. A long-term ingestion experiment should be conducted in several animal species to establish whether maleic hydrazide is carcinogenic by this route. Biotransformation studies should be undertaken along with pharmacokinetic studies to obtain a better understanding of the chemical's metabolism and excretion. Such investigations would firmly establish whether the tolerance formaleic hydrazide should remain or whether the use of the compound should be banned under the Delaney Amendment.

Animals

Pharmacological comparison of R(+), S(-) and racemic thiopentone in mice.

The i.p. LD50's of the enantiomorphs of thiopentone have the following increasing order of lethality R(+), racemate and S(-). Whereas the racemate and the S(-) compound have similar therapeutic indices, the R(+) compound has the highest value. The S(-) isomer is the most potent anesthetic agent, followed by the R(+) and the racemate. In the ability to block pentylenetetrazol- and strychnine-induced seizures, the compounds are ranked in the following order of decreased potency: S(-), racemate and R(+). The differences in potency between antipodes have been related to absolute steric configuration of the molecules. Differences in potency of the stereoisomers have been discussed in relationship to known metabolic conversions of thiopentone and its rapid penetration into body fat depots.

Animals

Strain differences in histopathologic, hematologic, and blood chemistry changes induced in mice by a technical and a purified preparation of 2,4,5-trichlorphenoxyacetic acid.

Including controls, 978 mice were studied. On days corresponding to days 6 through 14 of pregnancy, groups of pregnant and nonpregnant CD-1 mice and male and nonpregnant female dihybrid cross F2 mice received by gavage 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) ranging in dosage from 30 to 140 mg/kg. Some groups received a technical preparation containing 97.9 +/- 0.4% 2,4,5-T and some a purified preparation containing 99 +/- 0.3% 2,4,5-T. Mice were sacrificed when they became moribund and at 1, 2, 4, 6, 8, and 11 days after beginning treatment. Sick or moribund mice sacrificed after 2-9 doses of 2,4,5-T often showed severe myocardial lesions, hypocellularlity of the bone marrow, and depletion of lymphocytes in the thymus, spleen or lymph nodes. They also showed marked hematologic and blood chemistry changes. Treated mice remaining healthy showed few or no lesions or blood chemistry changes, but often developed a mild anemia attributable to a hemolytic effect of 2,4,5-T. The incidence of animals becoming moribund was less than 1% in the CD-1 mice, including those given 140 mg/kg, and 53-82% in groups of male and female F2 mice receiving 120 mg/kg 2,4,5-T. The incidence of moribund mice tended to be higher in male than in female F2 mice and in those given the purified compound. These findings indicate that impairment of maternal health by severe lesions early in gestation is not the primary cause of an increase in incidence of fetal abnormalities observed in mice given 2,4,5-t. they also indicate that the lesions are due primarily to 2,4,5-T, rather than contaminants in the technical preparation, and illustrate the importance of using more than one strain of mouse in a toxicologic or teratologic study.

2,4,5-Trichlorophenoxyacetic Acid