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Biomedical subjects

R D Jones

Publications and source records attributed to R D Jones.

At least 145 records · Page 8Linked to original sources
PubMed1990

A mortality follow-up study of pottery workers: preliminary findings on lung cancer.

The possible association between exposure to low levels of silica and lung cancer was investigated by following up pottery workers included in a survey conducted in 1970-71 of respiratory disease among such workers. The initial results show that, among men under the age of 60 at the time of the original survey, mortality has been similar to that expected, but that there was an excess of lung cancer of over 30% even after allowance had been made for cigarette smoking and place of residence. There were no particular excesses of lung cancer by product group or job group. However, there was some indication that lung cancer risk increased with estimated cumulative exposure to respirable quartz. These findings do suggest an association between lung cancer and the low levels of silica found in potteries, and the follow-up will therefore be continued and a more detailed analysis of the data carried out.

Adult↗
PubMed1990

Xylene/amitraz: a pharmacologic review and profile.

There are no reports of xylene/amitraz ingestion in children. Studies have characterized the adverse reactions caused by dermal applications in dogs, but the mechanisms involved were undetermined Accidental ingestion of the product by a child prompted a retrospective search of the medical records of the Georgia Animal Poison Information Center to profile the signalment, clinical signs, route of exposure and target sites of the suspected toxicosis in dogs. Clinical signs of depression, ataxia, stupor, and coma were most attributable to the xylene and propylene oxide components. Hyperglycemia, hypotension, and bradycardia were probably attributable to the alpha-2 adrenoceptor agonist action of amitraz. Most reports were initiated by owners, using the prescription product at home.

Animals↗
PubMed1990

A low cost ECG central station for intensive care.

A electrocardiogram (ECG) central station has been developed for the Intensive Care Unit at Christchurch Hospital. The system allows the selection and display of four ECGs selected from seven bedside monitors in the Unit. It also provides for automatic display, hard copy and audio alarm of ECG from any monitor which has detected an alarm condition--irrespective of whether that channel was being displayed prior to alarm detection. The system comprises a control unit (based on an 8085 microprocessor) and a mobile ECG station (4-channel ECG monitor, ECG recorder and computer terminal). Over the three years since its installation, the central station has been used 24 hours a day by medical and nursing staff and has proven to be a valued and reliable instrument in an intensive care environment.

Electrocardiography↗
PubMed1989

Expert system approach to detection of epileptiform activity in the EEG.

An expert system for the automated detection of spikes and sharp waves in the EEG has been developed. The system consists of two distinct stages. The first is a feature extractor, written in the conventional procedural language Fortran, which uses parts of previously published spike-detection algorithms to produce a list of all spike-like occurrences in the EEG. The second stage, written in the production system language OPS5, reads the list and uses rules incorporating knowledge elicited from an electroencephalographer (EEGer) to confirm or exclude each of the possible spikes. Information such as the time of occurrence, polarity and channel relationship are used in this process. A summary of the detected epileptiform events is produced which is available to the EEGer in interpreting the EEG. The performance of the expert system is compared with an EEGer using a 320s segment from an EEG containing epileptiform activity. The system detected 19 events and missed seven (false negative) which the EEGer considered epileptiform. There were no false positive detections.

Biomedical Engineering↗
PubMed1989

Effect of exposure of Pieris brassicae larvae to 2,4,5-trichlorophenoxyacetic acid on the natural antibacterial activity of serum.

Larvae of the cabbage white butterfly, Pieris brassicae, were reared on a semisynthetic diet with or without 20 ppm of the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and using three assays the sera were subsequently tested for natural antibacterial activity against Bacillus cereus, Escherichia coli K12, and Micrococcus luteus. These assays showed that exposure of larvae to 2,4,5-T lowered the antibacterial activity of the serum against E. coli and M. luteus compared with control animals. Spectrophotometric tests for the presence of a lysozyme-like principle in the serum also revealed similar trends with a significant loss of enzyme activity in 2,4,5-T-treated insects. Overall total serum protein levels of control and 2,4,5-T-treated insects were similar, suggesting a specific effect of the herbicide on certain serum components such as lysozyme. The possible mode of action of the herbicide on production of antibacterial factors is discussed.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1989

Impairment and recovery of ipsilateral sensory-motor function following unilateral cerebral infarction.

After unilateral cerebral hemisphere stroke, resulting in contralateral arm symptoms but largely sparing higher cerebral function, ipsilateral arm function is generally considered to be unaffected. In this study, 8 subjects with acute unilateral cerebral infarction (confirmed by CT scan) and primarily motor deficits underwent 11 computerized and 6 clinical assessments between 11 days and 12 months poststroke, and were compared with 12 normal subjects. Computerized tests comprised 3 pursuit tracking tasks (preview-random, step and a combination of these), designed to measure different aspects of integrated sensory-motor (S-M) function, and 12 tasks aimed at breaking tracking into various sensory, perceptual and motor components (joint movement sense, visual resolution, object perception, static and dynamic visuospatial perception, range of movement, grip and arm strength, reaction time, speed, static and dynamic steadiness). The asymptomatic arm was impaired on all but one of the computerized tests throughout the 12-month period, although to a lesser degree than the symptomatic arm. Grip strength was marginally impaired initially. Incomplete neurological recovery was seen in the asymptomatic arm for all functions except strength, speed and steadiness, possibly indicating their resistance to improvement. Clinical assessment detected no asymptomatic arm impairment and only a mild transient deficit of higher mental function. Our data suggest that (1) all cerebral hemisphere areas involved in S-M functions can exert some degree of bilateral motor control; (2) ipsilateral influence is never greater than contralateral influence, and is usually considerably less; and (3) the proportion of ipsilateral to contralateral control is closely related to the degree of continuous sensory feedback required by the particular task. The mechanism and degree of ipsilateral dysfunction can be explained by a 3-tier cerebral model of S-M integration comprising a lower level of functions with high contralateral specificity (somatosensory and motor), a middle level of non-limb-specific partially lateralized functions (ideomotor praxis and visuospatial perception) and an upper level of global mental activities (intellect, alertness, etc.).

Adult↗
PubMed1989

Character structure and performance on the MMPI.

In a sample of 74 normal adults, a typology of character structure based on the developmental theory of Piaget was used to predict performance on the MMPI. The typology's validity was assessed by examining its empirical relationship to 11 clinical scales of the MMPI. Significant differences among the character types were noted for 5 of the 11 scales examined (Hypochondriasis, Depression, Masculinity/femininity, Psychasthenia, and Ego strength). There were significant differences on three additional scales (Hysteria, Psychopathic deviate, and Hypomania) between subtypes of the most numerous character type, which included two-thirds of the subjects studied. Differences among the character types and subtypes were generally consistent with expectations.

Adult↗
PubMed1988

Effects of Light and CO on the Survival of a Marine Ammonium-Oxidizing Bacterium during Energy Source Deprivation.

The chemolithotrophic ammonium-oxidizing bacterium Nitrosomonas cryotolerans responds uniquely to nutrient deprivation by lowering its endogenous respiration and anabolic processes to undetectable levels during starvation, thus appearing to enter a dormant state. To ascertain whether this state protects the cells from further stresses (as seen with endospore-forming bacteria), the starved cells were subjected to two known inhibitors, CO and light. It was found that long-term-starved cells were less resistant than freshly starved cells to light inhibition. Both long-term-starved cells and freshly starved cells were unaffected by CO.

Journal Article↗
PubMed1988

A mortality study of vinyl chloride monomer workers employed in the United Kingdom in 1940-1974.

The mortality experience of 5,498 male workers employed for at least one year during 1940-1974 in the vinyl chloride industry of the United Kingdom was followed through to 31 December 1984. There was a significant excess of nonsecondary liver tumors with 11 deaths, of which seven were angiosarcomas. All the angiosarcoma deaths occurred in autoclave workers with a median latency of 25 years from date of first exposure. A strong healthy worker effect was seen. Other than that for liver cancer, no increased incidence of cancer deaths attributable to vinyl chloride monomer exposure was found. There was no evidence of increased mortality from chronic liver disease. The incidence of death from respiratory disease was low and was not affected by polyvinyl chloride dust exposure.

Adult↗
PubMed1988

Mesothelioma in Great Britain in 1968-1983.

The British mesothelioma register records deaths in Great Britain when the word "mesothelioma" is on the death certificate. In 1968-1983 the mesothelioma deaths among men increased from 114 to 467, while those among women increased from 38 to 90. In 1983 the crude mesothelioma death rates were 17.5 per million and 3.2 per million for the men and women, respectively. The Northern region had the highest crude rates. At the county level, the highest crude deaths rates in 1976-1983 were recorded for the men in Devon and for the women in Lancashire. Marked differences occurred in the ratio of deaths among men to deaths among women for mesothelioma of the pleura (4.6:1) and for mesothelioma of the peritoneum (2:1). The age-specific death rates for men and women diverged markedly for pleural mesothelioma but not for peritoneal mesothelioma. Trends in the use of asbestos and in age- and sex-specific death rates suggest that the annual number of mesothelioma deaths will continue to increase, possibly until the turn of the century. This increase will be concentrated among the men as the main asbestos exposure of women occurred during the war and the annual deaths due to this exposure may have already peaked.

Adult↗
PubMed1987

Use of thioridazine in the treatment of aberrant motor behavior in a dog.

Thioridazine, a phenothiazine derivative, was used in a dog to treat aberrant motor behavior consisting of tail mutilation, aggression, random biting into the air, frenzied locomotion, and vocalization. Use of this drug resulted in control of the behavior, which allowed the tail to heal. The dog returned to a docile and obedient nature.

Animals↗
PubMed1987

Gastroscopic localization of a microencapsulated KCl preparation in the human stomach.

A slow release polymer-coated preparation of potassium chloride granules (Micro-K Extencaps) was initially thought not to be associated with gastric mucosal damage. Recent studies have shown that acute gastric ulcers occur with approximately the same frequency as in patients taking wax matrix KCl formulations. The development of acute gastric ulcers was not consistent with the proposed dispersion characteristics of the microencapsulated KCl preparation. The authors therefore endoscopically evaluated the dispersion characteristics of microencapsulated KCl in a double-blind, placebo-controlled study. Subjects received four capsules of Micro-K or matching placebo and endoscopy was performed 30, 60, or 120 min after each drug ingestion. The material was identified with the Olympus HM (high magnification) endoscope and then quantitatively aspirated using the 3.5-mm biopsy channel of the Pentax 34JA endoscope. Microencapsulated KCl particles dispersed poorly and were found adhering to the mucosa and to one another, as a semisolid mass, most frequently in the gastric antrum. In contrast, the placebo (ethyl cellulose) was widely dispersed throughout the stomach. The authors concluded that gastric emptying must be considered in three phases: liquids, solids, and solids which adhere to the mucosa. No unique dispersion characteristics of Micro-K Extencaps were identified, and adherence of the KCl to the gastric mucosa may explain its ability to cause occasional acute gastric ulceration.

Adult↗
PubMed1987

Survey of the designs of racehorse stables in the south west of England.

The design of 96 racehorse stables in the south west of England were surveyed. The 'typical' racehorse is kept in a loose box, bedded on straw and remains indoors while the stable is cleaned. It is given a floor area of 12 m2 and shares its airspace of 39 m3 with seven other horses. Overall, the predicted minimum rate of air change by natural convection in calm winds is 6.6 air changes/h but this is reduced to 2.2 if the top door of the stable is closed. On balance, racehorse stables in use today are based on designs which are worse overall than the best available in the 19th century.

Air Movements↗