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Biomedical subjects

B J Howard

Publications and source records attributed to B J Howard.

At least 73 records · Page 4Linked to original sources
PubMed1995

Family-focused behavioral pediatrics: clinical techniques for primary care.

Whenever a behavioral or psychosocial problem presents in a child, all members of the family are affected. Conversely, when the problem lies within the family, the child is affected and often presents as the symptomatic patient. The goals of family-focused pediatrics are to: 1) determine the need for a family intervention; 2) conduct a family interview-assessment; 3) clarify the issues; 4) teach healthy communication skills and interactions; and 5) facilitate generation of family goals and solutions. Family-focused strategies provide an effective, brief, and timely approach that can aid the pediatrician in helping children and their families function in more healthy and satisfying ways.

Child↗
PubMed1994

Novel approaches to the estimation of intake and bioavailability of radiocaesium in ruminants grazing forested areas.

It is difficult to measure transfer of radiocaesium to the tissues of forest ruminants because they can potentially ingest a wide range of plant types. Measurements on undomesticated forest ruminants incur further difficulties. Existing techniques of estimating radiocaesium intake are imprecise when applied to forest systems. New approaches to measure this parameter are discussed. Two methods of intake estimation are described and evaluated. In the first method, radiocaesium intake is estimated from the radiocaesium activity concentrations of plants, combined with estimates of dry-matter (DM) intake and plant species composition of the diet, using plant and orally-dosed hydrocarbons (n-alkanes) as markers. The second approach estimates the total radiocaesium intake of an animal from the rate of excretion of radiocaesium in the faeces and an assumed value for the apparent absorption coefficient. Estimates of radiocaesium intake, using these approaches, in lactating goats and adult sheep were used to calculate transfer coefficients for milk and muscle; these compared favourably with transfer coefficients previously obtained under controlled experimental conditions. Potential variations in bioavailability of dietary radiocaesium sources to forest ruminants have rarely been considered. Approaches that can be used to describe bioavailability, including the true absorption coefficient and in vitro extractability, are outlined.

Animal Feed↗
PubMed1994

Dynamic behavior of 110mAg in sheep tissues.

The transfer coefficient of 110mAg to a range of sheep tissues and its biological half-life in these tissues has been determined. Liver was shown to be the major site of 110mAg deposition and retention, with a transfer coefficient of Ff 7.1 d kg-1 and a biological half-life of 79 d. These results also suggest that previous estimates of the transfer of silver to muscle were too high, although further work would be required to confirm this. There is a need for accurate data which can be used to predict the transfer of 110mAg to food-producing animals.

Animals↗
PubMed1994

Isoflurane isomers differ in preservation of ATP in anoxic rat hepatocytes.

The volatile anesthetic isoflurane inhibits the precipitous drop of ATP concentration that results from induced anoxia in isolated rat hepatocytes. This change is dose dependent and reaches its maximum at clinically relevant anesthetic concentrations. The use of highly purified isoflurane enantiomers has allowed a demonstration of the difference in the efficacy of the (+) and (-) isomers on the isoflurane-dependent preservation of ATP. The difference in relative potency between isomers was approximately 2.5-fold, with the (-) form being more potent. In a direct test of the anesthetic potency of these isomers, it was shown previously that the (+) isomer was more potent than the (-) isomer. Differences in the order of potency of isoflurane stereoisomers for the "anesthetic" and "metabolic" effects of isoflurane suggest that these effects are independent and may result from interactions with different specific molecular sites.

Adenosine Triphosphate↗
PubMed1993

Management methods of reducing radionuclide contamination of animal food products in semi-natural ecosystems.

Countermeasures involving changes in management practices which are suitable for use in semi-natural ecosystems are described. Most of the relevant information relates to radio-caesium, but the applicability for some other radionuclides has also been evaluated. Improved live-monitoring techniques for radiocaesium, developed since the Chernobyl accident, allow the identification of animals whose contamination levels exceed the intervention limits, so that countermeasures can be effectively chosen and targeted. Generally the most effective approach for domesticated and semi-domesticated animals is either to remove contaminated animals from the affected area or to provide uncontaminated feed. Uncontaminated feed is given continuously for dairy animals or in the final fattening stages for meat-producing animals. The introduction of other effective changes in management practices, such as changing hunting seasons for game, or slaughtering at a time of year when the animals have been grazing on less contaminated herbage, depends on a good understanding of the behaviour of radionuclides in these ecosystems. In practice, the most effective countermeasures which can used to reduce radionuclide contamination of animals in semi-natural ecosystems will be obtained by a combination of both management changes and the use of chemical binders to prevent gut absorption.

Animal Feed↗
PubMed1992

Development of a laboratory method to predict rapidly the availability of radiocaesium.

A simple extraction procedure has been developed to assess rapidly the probable extent of the transfer of radiocaesium into ruminant food products soon after a nuclear accident. The in vitro extractions were validated against true absorption measurements of different forms of radiocaesium in the sheep gut. Extractions were performed on a range of different radiocaesium sources. Some of these sources were artificial (ionic radiocaesium adsorbed onto bentonite, silica spheres and filter-papers) and others were environmentally contaminated [silt from the Ravenglass Estuary contaminated by effluent from British Nuclear Fuels Limited (BNFL) Sellafield, and upland grass and heather contaminated by Chernobyl fallout]. Laboratory experiments concentrated primarily on the use of simple inorganic extractants in competitive ion-exchange processes. Of the reagents used, 0.1 mol dm-3 stable caesium chloride solution was the most effective extractant. The proportion of radiocaesium extracted by 0.1 mol dm-3 caesium chloride correlated well with measurements of true absorption. Extracting radiocaesium using 0.1 mol dm-3 caesium chloride proved to be an inexpensive and rapid method of predicting the availability of radiocaesium for absorption in the ruminant gut, giving results within 24 h. Further extractions were carried out using cellulase/pepsin simulated digestions and ovine rumen fluid. Results suggested that the availability of radiocaesium from some inorganic sources may be underestimated using such techniques.

Accidents↗
PubMed1992

The differential responding of male prisoners to subtle and obvious MCMI subscales.

We investigated the differential responding of 100 male inmates to subtle and obvious MCMI scale items; subtlety was determined by judgments by college students. It has been predicted that item subtlety would be positively correlated with item endorsement. This prediction was supported across all 175 MCMI items, as well as across items on 7 of 8 personality and 8 of 12 clinical scales. It had also been predicted that education and intelligence would moderate the relationship between subtlety and endorsement, with inmates higher in education and intelligence demonstrating a greater tendency than other inmates to avoid obvious items. Modest support was obtained for this prediction, with statistically significant results found for 4 personality and 5 clinical scales. The significance of the subtle-obvious distinction is discussed, especially when employing the MCMI with an inmate population.

Adult↗
PubMed1991

The radioecological consequences for lowland pastures used to fatten upland sheep contaminated with radiocaesium.

Current farming practice in upland areas of Cumbria, England, affected by Chernobyl fallout is to remove lambs to lowland pastures for fattening prior to slaughter. The radiocaesium (137Cs and 134Cs) burden of lambs is rapidly lost via excreta deposited on the pasture. This may increase the radiocaesium activities in vegetation of these pastures. Studies were performed to assess the radioecological consequences of this practice. Results obtained from experiments were used to calibrate a soil/vegetation model which was used to predict long-term radiocaesium behavior.

Accidents↗
PubMed1991

The importance of soil adhered to vegetation as a source of radionuclides ingested by grazing animals.

Soil ingestion has been identified as a potentially important source of radionuclides to grazing animals. Seasonal patterns of soil adherence to vegetation and its implications for the radionuclide intake of grazing animals were measured at two west Cumbrian sites. Soil adhesion to vegetation was highly seasonal, being highest in autumn and winter. At Site 1 (a lowland pasture close to the British Nuclear Fuels plc Sellafield Reprocessing Plant, Cumbria, UK), vegetation samples were found to consist of up to 46% soil (by dry weight). Therefore, the importance of soil as a potential source of radionuclides to grazing animals was also seasonal; soil comprised up to 92% of the 137Cs and potentially all of the 239/240Pu of vegetation samples at Site 1 and up to 62% of the 137Cs at Site 2 (an upland farm contaminated following the Chernobyl accident). Analyses of sheep faecal samples confirmed the seasonal importance of soil as a potential source of radionuclides. The importance of soil adhering to vegetation, as a source of contaminant 137Cs, increased with time after the Chernobyl accident. Calculations of soil ingestion must be made when the intake of radionuclides by grazing animals is being studied. In some circumstances, present radioecological models may considerably underestimate the importance of soil ingestion.

Accidents↗
PubMed1991

Chemical speciation and bioavailability of elements in the environment and their relevance to radioecology.

The commonly used terms 'chemical speciation' and 'bioavailability' are discussed and an attempt made to produce both qualitative and quantitative descriptions of their influence on the transfer of elements in the environment. The importance of considering the presence of the many different species of radionuclides which may occur in the environment is emphasized. The limitations of using concentration ratios, which take no account of the differing bioavailability of various chemical species of radionuclides, are discussed.

Accidents↗
PubMed1991

Discipline in early childhood.

As pediatricians we have an opportunity and a responsibility to guide parents in the structure of discipline they set up for their children. The major goals of this structure are to help children develop a sense of being both lovable and capable. To feel lovable a child needs an enduring responsive relationship that conveys positive regard. Attending to children promptly, giving individual time daily, acknowledging positive behaviors, and ignoring minor transgressions all help them feel valued. Active listening without judgment demonstrates acceptance of children's feelings. Talking to children without labels or generalizations but with specific feedback about their actions and with congruent emotional tone is respectful and promotes self-esteem. Children also deserve assistance with transitions, thanks, and apologies as appropriate. To feel (and become) capable, children need a consistent structure of routines, good models, respectful instruction, and progressive expectations so that they have an ongoing experience of success. To grow as individuals they need opportunities to make choices relevant to their interests and role-taking opportunities to gain perspective on social interaction. Praise and rewards motivate as well as instruct children, but they also need to experience consequences to their actions. Natural consequences are optimal but parents also need to design logical consequences that are graded, related, prompt, and reasonable for a child's misbehaviors. Consequences are most effective when given after only one request, exactly as clearly promised by the adult involved without interference by others. Time out is one of the most effective consequences for young children when used properly. Physical punishment has multiple negative effects on a child's development, especially if used noncontingently. Intrapersonal and family factors predispose parents to predictable problems in establishing healthy discipline. Pediatricians can play an important role in promoting the emotional development of children by anticipating, guiding, and counseling families about discipline as well as referring them effectively.

Child Rearing↗
PubMed1991

Transfer of radiocesium to ruminants in natural and semi-natural ecosystems and appropriate countermeasures.

A review of studies conducted before and after the Chernobyl accident is presented, showing that both the duration and the extent of radiocesium contamination of ruminants will be more severe in unimproved ecosystems compared with agricultural areas. Although such unimproved ecosystems provide comparatively small quantities of food for human consumption, the integrated dose from these areas to the human population can be large. Ecological characteristics that make unimproved ecosystems particularly vulnerable to this form of pollution include the presence of (1) soils that do not immobilize radiocesium and therefore allow its uptake into vegetation; (2) vegetation species with high uptake rates of radiocesium; (3) the predominant utilization by small ruminants which attain higher muscle radiocesium levels than cattle. Unimproved ecosystems, which often are located at high altitudes, are predisposed to receiving higher fallout because of high precipitation rates which enhance the likelihood of deposition. Countermeasures have been developed and used successfully to reduce radiocesium levels in ruminants grazing in unimproved ecosystems. Apart from decontamination by altering farming practices and providing uncontaminated feeds, sustained reductions of 50% to 80% in the radiocesium concentrations of both milk and meat have been achieved in many ruminant species when AFCF is given via a sodium chloride lick or as a sustained-release bolus. Food production in unimproved ecosystems must be evaluated separately from that of ordinary agricultural systems. In addition to detailed studies on the behavior of radiocesium, consideration should be given to the collection of aggregated transfer coefficients from various ecosystems which were affected by Chernobyl fallout. By combining bioavailability estimates and aggregated transfer coefficients, based on Chernobyl and nuclear weapons test fallout data, it may in the future be possible to make a rapid assessment of both the immediate and the long-term impact of a future nuclear accident on food production in unimproved ecosystems.

Animals↗
PubMed1989

Transfer of radiocesium from different environmental sources to ewes and suckling lambs.

Indoor experiments are described that compare the transfer of radiocesium to ewe and lamb tissues from different sources. Lactating ewes were fed either perennial ryegrass contaminated by Chernobyl fallout, or saltmarsh vegetation contaminated by marine discharges from the Sellafield reprocessing plant. The transfer to ewe tissues and milk was greater from the Chernobyl contaminated herbage than from saltmarsh vegetation. Lambs receiving a mixture of vegetation and milk were given radiocesium from one of the two vegetation sources or from milk obtained from the experimental ewes. Transfer to lamb tissues declined in the order milk greater than Chernobyl fallout greater than Sellafield discharge. The radiocesium transfer to lamb tissues exceeded that to ewe tissues. Transfer coefficients for 137Cs in the Chernobyl fallout were higher than most previously published figures at 0.12 d kg-1 for ewe muscle and 0.50 d kg-1 for lamb muscle. The transfer coefficient for 137Cs from ewe milk to lamb muscle was 1.20 d kg-1.

Accidents↗
PubMedDate not supplied

Chernobyl radiocaesium in an upland sheep farm ecosystem.

Following the deposition of radiocaesium from the Chernobyl accident the movement and slaughter of sheep in upland areas of west Cumbria, Scotland and Wales was restricted. Studies on the radioecology of Cs-137 and Cs-134 have been conducted at a farm within the affected area of west Cumbria since July 1986. The radiocaesium activity of upland sheep was found to decline when they were brought on to the farms' enclosed pastures and rise when they were returned to the open fell, where the radiocaesium content of vegetation has remained higher than on the pastures. The Cs-137 activity concentration of mixed grassland vegetation samples from the fell has declined over the study period, whereas the Cs-137 activity of ewes whilst grazing on the fell was higher in summer of 1987 than in autumn 1986. A number of factors which may have contributed to this discrepancy were investigated and are discussed. It is suggested that husbandry changes would be effective in reducing the number of lambs leaving the restricted area with radiocaesium activities over the limit (1000 Bq/kg fresh weight Cs-134 + Cs-137) set by the United Kingdom authorities.

Accidents↗
PubMedDate not supplied

Improving quality and performance practices using fiberoptic endoscopes in perioperative areas: a case study.

In response to the impact of healthcare reform, a re-engineering of problem areas within the University of Maryland's Medical System needed to be initiated. A critical issue to be addressed, within the perioperative areas of the hospital, was the delay in service because of the unavailability of functional fiberoptic endoscopes. This resulted in spiraling operating costs and compromised quality of care of patients. Analysis of the situation using fiberscope inventory data revealed unreliable quality-controlled reprocessing systems and lack of knowledge by the staff in handling and caring for the fiberscopes. A number of actions were taken to improve staff patterns of performance. Graphs, spreadsheets, and diagrams were used to pinpoint the problem areas for each perioperative area and were presented to the staff. These data were up-dated monthly to inform staff and inspire further improvements in performance. This re-engineering of the fiberoptic scope delivery system resulted in economic, operational, customers, and quality of care benefits. Fiberoptic endoscopes are increasingly used is surgical fields outside of the traditional endoscopy unit. Endoscopic nurses need to share expertise to improve the quality of performance in all areas of the hospital where fiberoptic scopes are used.

Academic Medical Centers↗