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Biomedical subjects

R Jackson

Publications and source records attributed to R Jackson.

At least 73 records · Page 4Linked to original sources

Elderly and sun-affected skin. Distinguishing between changes caused by aging and changes caused by habitual exposure to sun.

OBJECTIVE: To review and distinguish between skin changes produced by aging and changes produced by habitual exposure to sun. QUALITY OF EVIDENCE: The literature was searched from 1969 to 1999 for articles on dermatoheliosis and sun-damaged skin. Surprisingly few were found comparing the difference between elderly skin and sun-damaged skin. A few articles focused on certain small aspects of sun-damaged skin. Many excellent articles described particular changes (e.g., actinic keratosis), but few covered all the changes due to aging and to sun. MAIN MESSAGE: Skin changes due to aging can be distinguished from those due to sun damage. All changes due to sun exposure can be grouped under the term dermatoheliosis; five parts of the skin are involved: epidermis (actinic keratosis), dermis (solar elastosis), blood vessels (telangiectasia), sebaceous glands (solar comedones), and melanocytes (diffuse or mottled brown patches). Habitual exposure to sun and a white skin are prerequisites for developing these changes. Knowing the difference between changes caused by sun and by aging can help physicians predict which patients are most likely to get skin cancers. CONCLUSION: Knowledge of these common skin changes will help physicians diagnose and manage the skin abnormalities of elderly people and of people with dermatoheliosis.

Aged↗

Interdisciplinary treatment of diabetes mellitus in a military treatment facility.

The American Diabetes Association emphasizes interdisciplinary management as the standard of care for patients with diabetes. Many times, however, interdisciplinary means various health care professionals treating a patient but not necessarily interacting with each other regarding the patient's care. Recently, Tripler Army Medical Center replicated the Joslin Diabetes Center's diabetes outpatient intensive treatment program as part of a Joslin Diabetes Center/Department of Defense/Veteran's Administration research collaboration. Tripler Army Medical Center named this interdisciplinary program Holopono, which is Hawaiian for success. Holopono is a team of health care professionals providing integrated care and education to a group of diabetes patients over 3.5 days. Individual care management, aided by an Internet-based telemedicine system, then continues for 1 year after entry into the program. This article describes the Holopono program, the role of each team member, and how the team functions together to provide comprehensive diabetes care.

Comprehensive Health Care↗

Identification of glucosyltransferase genes involved in sinapate metabolism and lignin synthesis in Arabidopsis.

Sinapic acid is a major phenylpropanoid in Brassicaceae providing intermediates in two distinct metabolic pathways leading to sinapoyl esters and lignin synthesis. Glucosyltransferases play key roles in the formation of these intermediates, either through the production of the high energy compound 1-O-sinapoylglucose leading to sinapoylmalate and sinapoylcholine or through the production of sinapyl alcohol-4-O-glucoside, potentially leading to the syringyl units found in lignins. While the importance of these glucosyltransferases has been recognized for more than 20 years, their corresponding genes have not been identified. Combining sequence information in the Arabidopsis genomic data base with biochemical data from screening the activity of recombinant proteins in vitro, we have now identified five gene sequences encoding enzymes that can glucosylate sinapic acid, sinapyl alcohol, and their related phenylpropanoids. The data provide a foundation for future understanding and manipulation of sinapate metabolism and lignin biology in Arabidopsis.

Arabidopsis↗

Temporal aspects of the epidemic of bovine spongiform encephalopathy in Great Britain: individual animal-associated risk factors for the disease.

The objectives of this study were first to determine the cumulative incidence of bovine spongiform encephalopathy (BSE) in the British cattle population from July 1986 to June 1997, secondly, to identify individual animal-associated risk factors that influenced the age of onset of clinical signs in confirmed BSE cases, and, thirdly, to assess the effectiveness of the measures introduced to control BSE during the epidemic. The analyses were based on the population of British cattle at risk, derived from agricultural census data collected between 1986 and 1996, and BSE case data collected up to June 30, 1997. The unit of interest was individual adult cattle recorded on annual agricultural censuses between June 1986 and June 1996. Univariate and multivariate survival analysis techniques were used to characterise the age of onset of clinical signs. In total 167,366 cases of BSE were diagnosed in Great Britain up to June 30, 1997. The cumulative incidence of BSE between July 1986 and June 1997 was 1.10 (95 per cent confidence interval [CI] 1.09 to 1.10) cases per 100 adult cattle at risk. Cattle from the South east, South west and Eastern regions of England had 4.26 to 5.96 (95 per cent CI 4.15 to 6.14) times as great a monthly hazard of being confirmed with BSE as cattle from Scotland. Compared with cattle born before June 1985, those born between July 1987 and June 1988 had 22.5 (95 per cent CI 22.1 to 22.8) times the monthly hazard of being confirmed with BSE, whereas those born in the 12 months after July 1988 had only 7.39 (95 per cent CI 7.24 to 7.54) times the monthly hazard of being confirmed with BSE. This reduction in hazard was directly attributable to the ban on the use of ruminant protein as a feed instituted in July 1988. Successive cohorts from 1989 to 1991 experienced further reductions in the hazard of experiencing BSE. The additional decrease in hazard observed for the 1990 cohort may be attributed to the effect of the Specified Bovine Offal ban instituted in September 1990.

Animals↗

Temporal aspects of the epidemic of bovine spongiform encephalopathy in Great Britain: holding-associated risk factors for the disease.

The objectives of this study were first to describe the pattern of the epidemic of bovine spongiform encephalopathy (BSE) in Great Britain in terms of the temporal change in the proportion of all cattle holdings that had experienced at least one confirmed case of BSE to June 30, 1997, and secondly to identify risk factors that influenced the date of onset of a holding's first confirmed BSE case. The analyses were based on the population of British cattle at risk, derived from agricultural census data collected between 1986 and 1996, and the BSE case data collected up to June 30, 1997. The unit of interest was the cattle holding and included all those recorded at least once on annual agricultural censuses conducted between June 30, 1986, and June 30, 1996. The outcome of interest was the date on which clinical signs were recorded in a holding's first confirmed case of BSE, termed the BSE onset date. Univariate and multivariate survival analysis techniques were used to describe the temporal pattern of the epidemic. The BSE epidemic in Great Britain started in November 1986, with the majority of affected holdings having their BSE onset date after February 1992. After adjusting for the effect of the size and type of holding, holdings in the south of England (specifically those in the Eastern, South east and South west regions) had 2.22 to 2.43 (95 per cent confidence interval [CI] 2.07 to 2.58) times as great a monthly hazard of having a BSE index case as holdings in Scotland. After adjusting for the effect of region and type of holding, holdings with more than 53 adult cattle had 5.91 (95 per cent CI 5.62 to 6.21) times as great a monthly hazard of having a BSE index case as holdings with seven to 21 adult cattle. Dairy holdings had 3.06 (95 per cent CI 2.96 to 3.16) times as great a monthly hazard of having a BSE index case as beef suckler holdings. These analyses show that there were different rates of onset in different regions and in holdings of different sizes and types, that the epidemic was propagated most strongly in the south of the country, and that the growth of the epidemic followed essentially the same pattern in each region of the country, with modest temporal lags between them. The control measures imposed in 1988 and 1990 brought the expansion of the epidemic under control, although the rate of progress was slowed by those regions where the effectiveness of the control methods took some time to take full effect.

Animals↗

A decade of intensive care unit trauma admissions in Auckland.

AIMS: To describe the demographics, nature and severity of injury of trauma admissions to a New Zealand urban Intensive Care Unit (ICU) over a ten year period; to determine differences in injury characteristics between patients received from inside and outside the local trauma catchment area; and to calculate incidence rates in the local population served, to identify high risk groups of patients. METHODS: We carried out a cross-sectional analysis of a prospective ICU patient registry. Data on all trauma admissions from 1988 to 1997 to the ICU of a large New Zealand urban hospital were studied with respect to age, gender, ethnicity, injury type and severity, and referral status. National Census data for the ICU catchment area were used to calculate incidence rates for local admissions. RESULTS: A total of 2305 trauma patients were admitted over the period of the study, accounting for 25% of all ICU admissions. The median age was 28 years and 75% were males. Blunt trauma, mostly due to motor vehicle crashes, accounted for 95% of admissions and penetrating trauma was very rare. The median Injury Severity Score (ISS) was 26 and most life threatening injuries occurred in the head region. Referred admissions were more severely injured and had a higher prevalence of severe head injury than local admissions. The ICU trauma admission rate for local patients was 34.6 per 100,000 person-years. Males had a higher rate than females in all age groups. New Zealand Europeans made up the majority of admissions, but Maori and Pacific Island males had the highest incidence rates. CONCLUSIONS: This study identified trauma as a major component of the ICU population. ICU trauma admissions were characterised by young males with head injuries resulting from motor vehicle crashes. Referred admissions were more severely injured than local admissions and would thus distort the estimated incidence of trauma in the local geographic region served. Calculation of incidence rates highlighted a significantly higher risk of ICU trauma admission amongst Maori and Pacific Islands people than New Zealand Europeans.

Adolescent↗

Is the apparent cardioprotective effect of recent alcohol consumption due to confounding by prodromal symptoms?

Previous research has reported a protective association between alcohol drinking and acute coronary heart disease in the 24-hour period after drinking. This study investigated whether this apparent protective association resulted from confounding due to the effect of prodromal symptoms on drinking behavior. In 1992, the authors conducted a case-control study that measured recent alcohol consumption and reasons for recent abstention from alcohol among patients with acute coronary heart disease identified from a community-based disease register and a representative control sample from the same community (Auckland, New Zealand). Cases were significantly more likely than controls to report recent abstention from drinking because they felt unwell. In unadjusted analyses, a protective association was observed between recent alcohol consumption and acute coronary heart disease; however, this association was weakened considerably after adjustment for the effect of prodromal symptoms on drinking behavior. The previously reported protective association between recent alcohol consumption and acute coronary heart disease appears to be largely due to the confounding effect of prodromal symptoms on drinking.

Alcohol Drinking↗

Using thresholds based on risk of cardiovascular disease to target treatment for hypertension: modelling events averted and number treated.

OBJECTIVE: To estimate the impact of using thresholds based on absolute risk of cardiovascular disease to target drug treatment to lower blood pressure in the community. DESIGN: Modelling of three thresholds of treatment for hypertension based on the absolute risk of cardiovascular disease. 5 year risk of disease was estimated for each participant using an equation to predict risk. Net predicted impact of the thresholds on the number of people treated and the number of disease events averted over 5 years was calculated assuming a relative treatment benefit of one quarter. SETTING: Auckland, New Zealand. PARTICIPANTS: 2158 men and women aged 35-79 years randomly sampled from the general electoral rolls. MAIN OUTCOME MEASURES: Predicted 5 year risk of cardiovascular disease event, estimated number of people for whom treatment would be recommended, and disease events averted over 5 years at different treatment thresholds. RESULTS: 46 374 (12%) Auckland residents aged 35-79 receive drug treatment to lower their blood pressure, averting an estimated 1689 disease events over 5 years. Restricting treatment to individuals with blood pressure >/=170/100 mm Hg and those with blood pressure between 150/90-169/99 mm Hg who have a predicted 5 year risk of disease >/=10% would increase the net number for whom treatment would be recommended by 19 401. This 42% relative increase is predicted to avert 1139/1689 (68%) additional disease events overall over 5 years compared with current treatment. If the threshold for 5 year risk of disease is set at 15% the number recommended for treatment increases by <10% but about 620/1689 (37%) additional events can be averted. A 20% threshold decreases the net number of patients recommended for treatment by about 10% but averts 204/1689 (12%) more disease events than current treatment. CONCLUSIONS: Implementing treatment guidelines that use treatment thresholds based on absolute risk could significantly improve the efficiency of drug treatment to lower blood pressure in primary care.

Adult↗

Intussusception following the Ladd procedure.

HYPOTHESIS: The Ladd procedure for malrotation predisposes children to postoperative intussusception (POI). DESIGN: Retrospective case-control review. SETTING: University-affiliated tertiary care pediatric hospital. PATIENTS: Five of 159 patients undergoing the Ladd procedure between 1995 and 1998 developed POI. Predisposing factors were sought by comparison with age-matched controls who underwent the Ladd procedure during the same period. The entire Ladd group was compared with all 1717 patients undergoing any other laparotomy during the same period for incidence of POI. MAIN OUTCOME MEASURES: Differences in weight, percentile weight, age, length of nasogastric suction, time to oral intake, and length of stay between Ladd patients developing POI and age-matched controls from the Ladd group were compared using the Mann-Whitney U test. Incidence of POI after the Ladd procedure and "other laparotomy" was compared using chi2 analysis. RESULTS: In the Ladd group, there were 5 cases of POI (3.1%). There was 1 case of POI (0.05%) after all other laparotomies (P<.001). Symptoms developed at a mean +/- SD of 7.2 +/- 2.1 days. Upper gastrointestinal tract with small bowel follow-through showed partial bowel obstruction in 4 cases and was normal in 1 case. Reexploration took place at a mean +/- SD of 9.2 +/- 2.8 days. Children developing POI after undergoing the Ladd procedure were less likely to be small for their age (P= .03) than age-matched controls undergoing the Ladd procedure. CONCLUSIONS: The Ladd procedure predisposes children to POI. Aggressive investigation, including reexploration, should not be delayed if a child has symptoms of prolonged ileus within 2 weeks after undergoing a Ladd procedure.

Case-Control Studies↗

Motorcycle engine size and risk of moderate to fatal injury from a motorcycle crash.

Current New Zealand law requires that motorcyclists with a learner or restricted licence ride a motorcycle with an engine capacity of 250 cc or less. Previous research has reported inconsistent findings regarding the relationship between cubic-capacity and risk of a crash. We sought to determine: (1) compliance with the law; (2) if the risk of an injury crash is increased for learner/restricted licence holders who do not comply with the cubic capacity regulations; and (3) whether the risk of an injury crash increases with increasing capacity of the motorcycle. A population-based case-control study was conducted in the Auckland region over a 3 year period from February 1993. Among the controls, 66% were riding motorcycles with a capacity greater than 250 cc. The percentages for those with: full, learner and restricted, and no licence were 82, 29 and 60%, respectively. There was no evidence that learner and restricted licence holders who did not comply with the cubic capacity requirement were at increased risk. It should be noted however, that 75% of those who were complying were doing so on motorcycles of 250 cc or less. Relative to motorcycles of less than 250 cc the risk of an injury crash was elevated by at least 50% for all cubic capacity categories, with the exception of the 251-499 group. There was, however, no consistent pattern of increasing risk as cubic capacity increased. The findings of this study coupled with the fact that cubic capacity is a poor measure of power suggest that, if cubic capacity was to remain the sole basis for restricting learner and restricted licence holders, consideration should be given to having a substantially lower cubic capacity than 250 cc. An analysis of risk in terms of power to weight ratio and style of motorcycle may provide a more useful insight into the benefits of motorcycle design restrictions for novice riders.

Accidents, Traffic↗

Knowledge and willingness to use emergency contraception among low-income post-partum women.

We performed a multivariate analysis to determine factors associated with knowledge and willingness to use emergency contraception in a consecutive sample of 371 post-partum women from an inner-city public hospital. Women were queried about previous contraceptive use, pregnancy history including abortions and unplanned pregnancies, and demographic characteristics. Outcomes included knowledge of emergency contraception and willingness to use it. Questionnaires were conducted in person, in English or Spanish.Of 371 women, 3% had used emergency contraception, 36% had heard of it, and 7% knew the correct timing for use. Two-thirds of the population indicated a willingness to use emergency contraception in the future. Factors positively associated with knowledge included being a teenager or more than 30 years old, prior use of condoms, and history of an elective abortion. Being multiparous, monolingual Spanish-speaking, or Asian were negatively associated with knowledge. Willingness to use emergency contraception was positively associated with being multiparous and negatively associated with a higher income, moral or religious objections to the use of emergency contraception, a belief that it is unsafe or a perception that it is an abortificient. Knowledge about emergency contraception, especially correct timing, remains low. Multiparous women should receive increased education given their lack of knowledge but willingness to use emergency contraception. In order to increase the acceptability of emergency contraception, educational efforts must include accurate information about its mechanism of use and safety.

Adolescent↗

Office systems intervention to improve diethylstilbestrol screening in managed care.

OBJECTIVE: To examine the effectiveness of a comprehensive office systems intervention for improving identification of diethylstilbestrol (DES) exposure, a low-incidence condition with potentially severe consequences. METHODS: We developed a comprehensive office systems intervention to facilitate screening and follow-up for women exposed to DES in utero, consisting of a DES toolkit and the clinical and administrative education necessary to use the tools effectively. The intervention was implemented in the internal medicine and obstetrics-gynecology departments at six free-standing health centers in a Boston-area staff-model health maintenance organization. Intervention sites were matched and paired with a comparison group of centers. Intervention effectiveness was assessed through pretest and posttest surveys of clinicians, medical record review of 3900 women, and review of a computerized medical records data base. RESULTS: There was significantly higher DES awareness and knowledge among clinical staff at intervention sites. Documentation of DES exposure in the medical record ranged from 1.14 to 2.31 times greater at intervention sites than in matched comparison sites, and rates of DES code use in pregnancy were 1.91 to 3.61 times greater. CONCLUSIONS: The office systems intervention improved documentation of DES exposure in a managed care environment. Because this approach was designed to accommodate the limited time allotted for each patient visit, it not only improved DES screening but could also serve as a model for integrating screening for other low-prevalence but potentially serious conditions into routine care.

Adult↗

Comparative effects of quaternary ammonium mouthrinses on 4-day plaque regrowth.

BACKGROUND: Quaternary ammonium compounds constitute a large group of antibacterial chemicals with a potential for inhibiting plaque and gingivitis. One compound, benzalkonium chloride (BC), may be of value, although there is a dearth of evidence to support efficacy. The aim of this study was to measure the ability of 2 BC mouthrinses (0.05% and 0.1%) to inhibit de novo plaque reformation. METHOD: A 4-day plaque regrowth model. For comparative purposes, a commercial mouthrinse containing cetyl pyridinium chloride (CPC) and a positive control chlorhexidine (CX) mouthrinse were also evaluated. RESULTS: Compared to water control, a reduction in plaque scores of 52% was noted for the CX mouthrinse, 22.5% for CPC and 5% and 6% for the 2 BC rinses. For plaque area, reductions of 84%, 47%, 16% and 15% were found for CX, CPC, and the 2 BC rinses, respectively. Significant reductions in plaque area compared to the water rinse were also seen with the 2 BC rinses (p<0.05). However, for both plaque score and plaque area, the CX and CPC rinses significantly reduced plaque compared to the BC rinses (p<0.0001). CONCLUSIONS: These findings would suggest that the 2 benzalkonium rinses would only have a limited value at inhibiting plaque formation.

Analysis of Variance↗