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Biomedical subjects

A Hodgson

Publications and source records attributed to A Hodgson.

70 records · Page 4Linked to original sources
PubMed1986

Efficacies of LICAM(C) and DTPA for the decorporation of inhaled transportable forms of plutonium and americium from the rat.

The efficacies of N1, N5, N10, N14-tetrakis (2,3-dihydroxy-4-carboxybenzoyl)-tetra-azatetradecane [LICAM(C)] and diethylenetriaminepenta-acetic acid (DTPA) (30 mumol/kg body wt.) have been investigated for plutonium (Pu) decorporation after inhalation as the nitrate or tributyl phosphate (TBP) complexes and the data compared with those obtained after its intravenous injection as the citrate. The efficacy of removal of americium (Am) inhaled as the nitrate has also been examined. The results show that: whereas LICAM(C) and DTPA were similarly effective for removing Pu from the blood, LICAM(C) was considerably inferior to DTPA when transportable forms of Pu were inhaled; LICAM(C) is ineffective for the decorporation of Am; the optimum treatment regimen for both Pu and Am involved the prompt and repeated administration of DTPA.

Aerosols↗
PubMed1985

Metabolism of an industrial uranium trioxide dust after deposition in the rat lung.

UNLABELLED: Uranium trioxide, produced industrially, was administered to rats either by inhalation or direct injection of an aqueous suspension into the lungs. THE RESULTS: show that uranium was cleared rapidly from the lungs, mainly to the blood; show that distribution of uranium among body tissues, and the fraction of the systemic content excreted in urine, was similar to that obtained for other transportable hexavalent uranium compounds; suggest that urine monitoring data would be of more value than lung radioactivity counting measurements for assessing occupational human exposure; indicate that for setting exposure limits by inhalation the uranium trioxide should be considered a highly transportable compound. Thus intakes by workers should be restricted to those recommended for short-term exposures and not those based on an annual limit.

Aerosols↗
PubMed1985

Use of DTPA for increasing the rate of elimination of plutonium-238 and americium-241 from rodents after their inhalation as the nitrates.

This study has shown that: both inhaled (2 mumol/kg) and injected (30 mumol/kg) diethylenetriaminepenta-acetic acid (DTPA) can reduce the lung deposit of 238 Pu and 241 Am inhaled as nitrate to about 1% of that in untreated controls; injection of DTPA is more effective than aerosolized DTPA for reducing deposits of 238Pu and 241Am in the liver and skeleton; combined treatment involving early inhalation of DTPA followed by repeated intravenous injections is likely to be the most effective treatment for workers who have accidentally inhaled plutonium and americium nitrates.

Aerosols↗
PubMed1984

A microcomputer based system for quantifying the spatial distribution of inhaled particles in histological lung sections.

A system is described for quantifying the spatial distribution of inhaled particles in complete lobar histological sections of rodent lung. It is based on a semi-automatic image analyser, linked to a readily available microcomputer. Application of the system to quantify the aggregation of particles, and their distances from airways and lung periphery is described. The observed distributions are compared with the expected distributions from a random set of particles, and the significance of the difference is calculated. Each statistical test is illustrated by an example.

Aerosols↗
PubMed1982

Differential retention of 212Pb ions and insoluble particles in nasal mucosa of the rat.

The time course of retention of 212Pb ions in ciliated nasal epithelium and of tagged insoluble particles, which served both as a deposition vector and marker for mucus, was measured in 13 rats by counting the head externally at 2 min intervals up to 100 min after deposition. On average, 70-75% of insoluble particles introduced onto ciliated epithelium in 3 microliters of distilled water were cleared to the gut with a half-time of approximately 15 min (range 6-35 min). A smaller fraction of lead ions (averaging about 60%) introduced in the same water sample was cleared to the gut with a half-time in each rat similar to that of particle clearance. Rapid uptake of about 8% of deposited 212Pb into blood was also observed. A compartment model consistent with the observed nasal retention and appearance of 212Pb in blood showed that, on average, 8% of deposited lead ions were transferred to the blood with a half-time of 15 min. For about 35% of the deposited lead ions and 25% of the particles, no clearance was detected up to 60-100 min after deposition. It is probable that a fraction of the lead ions are retained by epithelial tissue.

Absorption↗
PubMedDate not supplied

The IL-6 G-174C polymorphism may be associated with ischaemic stroke in patients without a history of hypertension.

BACKGROUND: Recent data suggest that inflammatory reactions are involved in the pathogenesis of cerebral ischaemia. AIM: To investigate whether certain inflammatory genetic polymorphisms are associated with the occurrence of ischaemic stroke. METHODS: We investigated the prevalence of six polymorphisms in cytokine genes (IL-6, TNF-alpha, TNF-beta, IL-1beta, IL-10, and IL-1Ralpha) in a group of ischaemic stroke patients (n = 105) and in a control population (n = 389). We analysed the prevalence of these polymorphisms in different stroke subtypes and in relation to outcome six months post-stroke. RESULTS: There was no significant variation in cytokine gene polymorphism frequencies between control and stroke populations or for different stroke subtypes. Subgroup analysis demonstrated that the prevalence of the IL-6 -174 CC genotype was significantly lower in stroke patients without a history of hypertension compared to controls. CONCLUSION: The IL6 -174 CC genotype may be protective against stroke in those patients who have no history of hypertension. Further studies are required to verify these findings.

Adolescent↗
PubMedDate not supplied

Risk factors for meningococcal meningitis in northern Ghana.

Meningococcal meningitis is a major cause of morbidity and mortality in the meningitis belt of sub-Saharan Africa where it occurs in epidemics every 8-12 years. Risk factors for the disease in this setting remain largely unknown. We carried out a case-control study to investigate possible risk factors among survivors of a meningitis epidemic occurring in 1997 in northern Ghana. A structured questionnaire on socio-economic factors, housing and household overcrowding, smoking and exposure to smoke and close contact with a case was administered to 505 of the survivors and 505 of age-, sex- and location-matched controls. Cooking in kitchens with firewood stoves (OR 9.00, CI 1.25-395) and sharing a bedroom with a case (OR 2.18 CI 1.43-3.4) were found to be risk factors for disease. Socio-economic factors, overcrowding, smoking and passive exposure to tobacco smoke were not found to be risk factors. Exposure to smoke from cooking fires or close contact with a case puts people at risk of contracting meningococcal meningitis. In the hot dry months, exposure to smoke from cooking fires should be minimized by encouraging alternatives to cooking over wood fires, or cooking outside. If wood-burning stoves cannot be avoided, kitchens should be made larger with improved ventilation. Meningitis cases should be nursed in well-ventilated rooms and the number of people sharing a room with a case kept at a minimum.

Adolescent↗
PubMedDate not supplied

Mortality in a seven-and-a-half-year follow-up of a trial of insecticide-treated mosquito nets in Ghana.

A 17% efficacy in preventing all-cause mortality in children aged 6-59 months was previously reported from a cluster-randomized controlled trial of insecticide-treated mosquito nets (ITNs) carried out in the Kassena-Nankana District of northern Ghana from July 1993-June 1995. A follow-up until the end of 2000 found no indication in any age group of increased mortality in the ITN group after the end of the randomized intervention. These results should further encourage the use of ITNs as a malaria control tool in areas of high endemicity of Plasmodium falciparum.

Bedding and Linens↗