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Biomedical subjects

J Watkins

Publications and source records attributed to J Watkins.

At least 37 records · Page 2Linked to original sources

Coverage by the news media of the benefits and risks of medications.

BACKGROUND: The news media are an important source of information about new medical treatments, but there is concern that some coverage may be inaccurate and overly enthusiastic. METHODS: We studied coverage by U.S. news media of the benefits and risks of three medications that are used to prevent major diseases. The medications were pravastatin, a cholesterol-lowering drug for the prevention of cardiovascular disease; alendronate, a bisphosphonate for the treatment and prevention of osteoporosis; and aspirin, which is used for the prevention of cardiovascular disease. We analyzed a systematic probability sample of 180 newspaper articles (60 for each drug) and 27 television reports that appeared between 1994 and 1998. RESULTS: Of the 207 stories, 83 (40 percent) did not report benefits quantitatively. Of the 124 that did, 103 (83 percent) reported relative benefits only, 3 (2 percent) absolute benefits only, and 18 (15 percent) both absolute and relative benefits. Of the 207 stories, 98 (47 percent) mentioned potential harm to patients, and only 63 (30 percent) mentioned costs. Of the 170 stories citing an expert or a scientific study, 85 (50 percent) cited at least one expert or study with a financial tie to a manufacturer of the drug that had been disclosed in the scientific literature. These ties were disclosed in only 33 (39 percent) of the 85 stories. CONCLUSIONS: News-media stories about medications may include inadequate or incomplete information about the benefits, risks, and costs of the drugs as well as the financial ties between study groups or experts and pharmaceutical manufacturers.

Alendronate↗

The impact of a picture archiving and communication system (PACS) upon an intensive care unit.

OBJECTIVE: The aim of the study was to assess the effect of the introduction of PACS (Picture Archiving and Communication System) upon image availability in an Intensive Care Unit (ICU) and the consequent impact upon the behaviour of the ICU physicians, in terms of the initiation of image-based clinical actions. DESIGN: A before and after study was used to compare the speed of image availability prior to, and following, the implementation of a hospital-wide PACS. SETTING: The research was part of an economic evaluation of PACS at Hammersmith Hospital, West London. PATIENTS AND PARTICIPANTS: All ICU patients who were X-rayed during two pre-PACS and one post-PACS data collection periods were included within the study. MEASUREMENTS: The times of: the X-ray request; acquisition; availability on ICU; and of any image-based clinical action taken by the ICU physician were recorded by radiographers and ICU physicians. RESULTS: PACS significantly reduced the time between request and image availability on ICU for routine X-rays but did not have any measurable impact upon the time clinical actions were initiated by ICU physicians. The data on non-routine images were statistically inconclusive. CONCLUSIONS: This study shows that PACS significantly improves the speed of delivery of routine images to the ICU, but it appears that the instigation of image-based clinical actions is determined by other organisational factors in ICU, such as ward rounds, rather than the availability of the image for viewing. Further work is required on non-routine X-rays to clarify the impact of PACS on physician behaviour in clinically urgent situations.

Humans↗

Residual neurologic deficits 30 years after occupational exposure to elemental mercury.

A battery of tests of peripheral and central nervous system function was administered to 205 former workers of a large heavy industrial plant, 104 of whom were previously exposed to inorganic mercury. The mean age of those examined was 71 years. Exposed subjects had participated in a urine-mercury exposure monitoring program during the time of operation of a process that required the use of mercury and its subsequent clean-up. Mercury exposure had been high (mean peak urine mercury concentration was >600 microg/l) and had ended 30 years or more prior to the investigation. Peripheral nerve function outcomes that were statistically significantly associated with cumulative mercury exposure after controlling for covariates included classification as having peripheral neuropathy, peroneal motor nerve conduction velocity, ulnar motor nerve conduction velocity, and peroneal motor nerve F-wave latency. Quantitative assessment of resting tremor was nearly significantly associated with cumulative mercury exposure (p=0.07). Among tests of central nervous system function, results of the Handeye Coordination test were significantly associated with cumulative mercury exposure after controlling for covariates. Cumulative mercury exposure was not observed to be associated with a quantitative measure of dementia or with a number of cognitive neurobehavioral test outcomes. The statistically significant associations with mercury exposure were observed in spite of greater mortality among the exposed group than the unexposed group. These results suggest that substantial occupational mercury exposure can have long-term adverse effects on the peripheral nervous system detectable decades after cessation of exposure. Such long-term adverse effects were not observed for a measure of dementia or other measures of cognitive function.

Adult↗

Hydrolysis of menhaden oil by a Candida cylindracea lipase immobilized in a hollow-fiber reactor.

A lipase from Candida cylindracea immobilized by adsorption on microporous polypropylene fibers was used to selectively hydrolyze the saturated and monounsaturated fatty acid residues of menhaden oil at 40 degrees C and pH 7.0. At a space time of 3.5 h, the shell and tube reactor containing these hollow fibers gives a fractional release of each of the saturated and monounsaturated fatty acid residues (i.e., C14, C16, C16:1, C18:1) of ca. 88% of the corresponding possible asymptotic value. The corresponding coproduct glycerides retained over 90% of the initial residues of both eicosapentaenoic (EPA; C20:5) and docosahexaenoic (DHA; C22:6) acids. The half-life of the immobilized lipase was 170 h when the reactor was operated at the indicated (optimum) conditions. Rate expressions associated with a generic ping-pong bi-bi mechanism were used to fit the experimental data for the lipase catalyzed reaction. Both uni- and multiresponse nonlinear regression methods were employed to determine the kinetic parameters associated with these rate expressions. The best statistical fit of the uniresponse data was obtained for a rate expression, which is formally equivalent to a general Michaelis-Menten mechanism. After reparameterization, this rate expression reduced to a pseudo-first-order model. For the multiresponse analysis, a model that employed a normal distribution of the ratio of Vmax/Km with respect to the chain length of the fatty acid residues provided the best statistical fit of the experimental data.

Bioreactors↗

A hospital-wide picture archiving and communication system (PACS): the views of users and providers of the radiology service at Hammersmith Hospital.

OBJECTIVE: To obtain users' views of the new picture archiving and communication system (PACS) from clinical and radiological staff at Hammersmith Hospital, UK. METHODS: Semi-structured interviews were used to ascertain the views of staff, following an interview schedule which covered aspects of: (1) their use of PACS, (2) facilities available, (3) the perceived quality of images, (4) reporting, (5) image availability, (6) image accessibility, (7) training, and (8) ease of use of PACS. RESULTS: Interviews were carried out with 34 key users and providers of the radiological service at Hammersmith Hospital. Overall, staff were very satisfied with PACS particularly in terms of image availability. All staff said that they preferred PACS to the previous, conventional radiology service. CONCLUSIONS: The key implications of issues raised by staff were: the impact of 'down-time' and the importance of an efficient back-up system, the requirement for sufficient short-term storage to prevent images being off-line during clinical situations, the usefulness of the folder system for management of the images, the need to access images for teaching purposes, the advantage of having a default display protocol to facilitate radiological reporting, and the requirement for flexible, yet effective, training to ensure that the system is utilised to its full potential by users.

Attitude of Health Personnel↗

Evaluation of a hospital picture archiving and communication system.

OBJECTIVES: To establish the net costs to the hospital and the broad range of benefits associated with a hospital-wide picture archiving and communication system (PACS) that comprised digital acquisition, storage and transmission of radiological images via a hospital-wide network to 150 workstations. METHODS: 'Before and after' comparisons and time series analyses at Hammersmith Hospital (London, UK), and comparison with five other British hospitals where PACS was not being installed. The cost analysis considered implementation costs and changes in key elements of hospital running costs, including the impact of changes in the length of inpatient stays. A range of benefit measures were investigated, including image availability, avoidance of repeat imaging, avoidance of exposure to radiation, patient turn-round speed, time from examination to image availability in intensive care, avoidance of diagnostic 'errors' by casualty doctors, the additional diagnostic value of PACS-based images and clinician satisfaction. RESULTS: The annual equivalent capital cost of the PACS was 1.7 million Pounds (annual equivalent replacement cost: 0.8 million Pound). Overall, the PACS substantially increased running costs. No convincing evidence of a PACS-induced change in length of inpatient stay was found. PACS was associated with some improvements in the performance of the radiology department: improved image availability (97.7% versus 86.9%), lower repeat imaging rate (7.3% versus 9.9%) and 20% lower total radiation doses for examinations of the lateral lumbar spine. No improvements were identified in the quality of the radiology reporting service. Benefits outside radiology included shorter time from examination to image availability for routine uses in intensive care (19 versus 37 minutes), and a lower rate of diagnostic 'errors' in casualty (0.65% versus 1.51%). High levels of satisfaction with PACS were found amongst both providers and clinical users. CONCLUSIONS: PACS was almost universally preferred by users and brought many operational and clinical benefits. However, these advantages came at a significant capital and net running cost.

Cost-Benefit Analysis↗

Commitment to care: managed care and child incarceration.

Downsizing and managed care in the 1990s followed the psychiatric hospital scandals and closures of the 1980s. Many families are now unable to provide care for their troubled children. Childhood emotional or behavioral disorders have rapidly spread beyond the confines of the home into a community that has adopted a "zero tolerance" for crime. Intolerance for childhood criminal behavior has resulted in an explosion of children's prisons where, in the name of rehabilitation, many are finally receiving psychological help. This article discusses the decreased treatment of childhood psychiatric disorders and the increased admissions to children's prison facilities.

Adolescent↗

Synergy between amylin and cholecystokinin for inhibition of food intake in mice.

Several gastrointestinal peptides which are secreted in response to nutrients have been reported to suppress food intake. Amylin is a peptide hormone co-secreted with insulin from pancreatic beta-cells in response to nutrient stimuli. Cholesystokinin (CCK) is secreted from duodenal and jejunal mucosal cells in response to fat and protein. Amylin and CCK-8 have been reported to reduce food intake in rodents when given centrally as well as peripherally. Amylin injected intraperitoneally (i.p.) reduced food intake over the subsequent 30 min in overnight fasted mice by a maximum of 57 +/- 6% with an ED50 of 0.93 nmol/kg (3.63 microg/kg) +/- 0.34 log units. On a molar basis, this potency was similar to that of CCK-8 (ED50 0.85 nmol/kg (0.97 microg/kg) +/- 0.28 log units; p = 0.93) which inhibited food intake by a maximum of 71 +/- 7%. When amylin and CCK-8 were injected i.p. as an amylin:CCK-8 mixture, immediately before presentation of food in overnight fasted mice, food intake in the subsequent 30 min was reduced by a maximum of 91%, an amount that was greater than that producable by i.p. injection of amylin or CCK-8 alone. Isobolar analysis revealed a marked synergy between amylin and CCK-8 in reducing food intake, such that statistically ineffective doses of amylin and CCK, when combined, evoked near-maximal inhibition of food intake. Because the typical physiological event is for amylin and CCK both to be secreted in response to mixed meals, the synergy between them could indicate a shared role in physiological appetite control.

Amyloid↗

Assessment of motivations for return donation among deferred blood donors. American Red Cross ARCNET Study Group.

BACKGROUND: The recent addition of a computerized donor deferral registry to American Red Cross blood donation procedures has enabled blood center staffs to identify, before donation, persons who attempt to donate despite previous deferral. The current study investigated reasons that deferred donors return to donate, despite having been notified that they are ineligible. STUDY DESIGN AND METHOD: Anonymous mail surveys requesting demographic information, details of last donation or attempted donation, and assessments of incentives for donating were sent to 311 donors presenting inappropriately at blood drives and 849 matched controls in three American Red Cross regions between April and July 1996. RESULTS: Responses were received from a total of 113 deferred donors and 388 matched controls. Analysis of the 49 permanently deferred donors indicated that they were more likely than controls to donate blood to receive test results or to be awarded community service credit. Responses also revealed that some deferred donors may return to donate blood because of a misunderstanding of the deferral message or erroneous recruitment by blood center staff. CONCLUSION: There is a need before donation for the provision of educational materials regarding the window period of infection and for careful consideration of the use of incentives to attract donors to blood centers. It is also important to provide to donors a clear and consistent message regarding their test results and deferral status.

Altruism↗

Radiology report times: impact of picture archiving and communication systems.

OBJECTIVE: We investigated the impact on radiologist reporting time of the change from conventional film to hard-copy computerized radiography and of the subsequent move to soft-copy images on picture archiving and communication system (PACS) workstations. MATERIALS AND METHODS: A controlled before and after research design was undertaken. Data were collected on four occasions: two relating to conventional film, one relating to hard-copy computerized radiography, and one relating to soft-copy PACS images. Data collection was by direct observation of radiology reporting sessions by independent health service researchers. Data were collected on report times, details of images viewed, characteristics of the radiologist, and details of interruptions. To control for potential biases in the before and after comparisons, ordinary least squares multiple regression analysis was used. The principal comparison was between reports with PACS and reports with computerized radiography hard-copy because no change was noted in the organization of the reporting process between these two data collection rounds other than the introduction of the PACS. RESULTS: Data were collected on a total of 5568 report observations. Report time in the PACS data collection period was not significantly different (p = .32) than that in the computerized radiography hard-copy period. Reporting with the PACS was associated with significantly more (p < .01) historical images (i.e., images of the same patient obtained in previous examinations) being viewed. CONCLUSION: Report time was not lengthened by the introduction of the PACS. The finding that more historical images were viewed when the PACS was in use indicates that the PACS brought about a positive change in reporting practice.

Bias↗

Submitting a paper to the Society's Journal.

Each Journal has its own specific requirements for authors dealing with matters such as type of papers published, instructions for their submission and their layout and content. Requirements of authors are printed on the back cover of each issue of the Journal of the Royal Society of Health. This paper explores these in more detail and updates them for 1997 and onwards.

Bibliographies as Topic↗

The impact of the 1993 Braer oil spill on grey seals in Shetland.

Signs of acute respiratory distress were reported in moulting grey seals (Halichoerus grypus) hauled out on Lady's Holm, Shetland, following the Braer oil spill in January, 1993. Behavioural observations carried out between 16 January and 13 February 1993 showed that the proportion of animals exhibiting a discharge of nasal mucus was significantly higher than the proportion at a control site in the north (Papa Stour). The proportion of animals affected on Lady's Holm increased for up to one month following the spill. However, the time lag between exposure and peak response was approximately 30 days, longer than may be expected for an acute effect. The proportion of non-specific signs of respiratory distress in unexposed Shetland seals was assessed from observations made between 16 January and 25 January 1994. Symptoms similar to those seen in 1993 were also reported during this period, but the proportion of affected animals was higher in 1993. Symptoms were not observed at a grey seal moult site on the east coast of England in March 1993 and 1994. Grey seals moulting in Shetland during the time of the oil spill may have been acutely affected by exposure to hydrocarbons, but without sufficient baseline data on the occurrence of respiratory distress in grey seals it is difficult to determine the proportion attributable to other causes.

Animals↗