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Biomedical subjects

J Brown

Publications and source records attributed to J Brown.

At least 217 records · Page 12Linked to original sources

Why do children vomit after minor head injury?

OBJECTIVE: To determine factors associated with vomiting after minor head injury in a paediatric population with the intention of defining the role of vomiting in management decisions. METHODS: A prospective study of all patients presenting with minor head injury to the Royal Hospital for Sick Children, Edinburgh, between 1 May and 30 June 1997. Information regarding basic demographics, features of the head injury and past and family history was noted on a proforma. This included mechanism of injury, site of impact, presence or absence of scalp haematoma, skull fracture or brain injury and intrinsic factors such as age, family history of migraine and a personal history of migraine, its childhood variants and associated conditions. The relation between vomiting and these features was analysed using chi2 and Fisher's exact tests. RESULTS: 563 children aged from birth to 13 years presented with minor head injury. Complete data were obtained on 463 patients. Some 15.8% vomited after minor head injury. Comparing vomiters with non-vomiters the only associated factors that could be identified were a past history of recurrent vomiting or motion sickness (p= 0.0035, p=0.036 respectively). CONCLUSIONS: Vomiting after minor head injury seems to be related to individual intrinsic factors rather than specific features of the head injury and its role in management decisions needs to be explored further.

Adolescent↗

Cost of quality management and information provision for screening: colorectal cancer screening.

OBJECTIVE: To estimate the costs of a quality management (QM) system as proposed by the Quality Management for Screening report for a future national colorectal cancer screening programme. METHODS: Estimates of the costs of the QM system, including the associated costs of education and training and information provision, were based on expert opinion, the existing literature, and the experience of the current National Health Service (NHS) breast cancer screening programme (BSP) and the NHS cervical cancer screening programme (CSP). RESULTS: The cost of a QM system to support a national colorectal cancer programme in the UK was estimated as approximately 3.8 million a year. Further annual costs related to QM will include 500000 for education and training and 200000 for information provision. Adding these additional costs to a previously published UK economic evaluation of colorectal cancer screening increases the cost-utility ratio to approximately 6500 per quality adjusted life year gained (over an eight year follow up period). CONCLUSIONS: Any new screening programme, or an existing one, must have QM to ensure that the quality of screening is high and to maintain the right balance between benefit and harm. The significant costs of such a QM system should be included in any economic evaluation of a screening programme.

Budgets↗

Monocyte chemoattractant protein-1 and RANTES are chemotactic for graft infiltrating lymphocytes during acute lung allograft rejection.

Graft infiltrating lymphocytes (GILs) are crucial to rejection of lung allografts. However, chemotactic activities, chemokines responsible for GIL recruitment, and cells involved in chemokine production during lung allograft rejection have not been evaluated. This study determined whether chemotactic activity for GILs is upregulated, and whether the chemokines monocyte chemoattractant protein (MCP)-1 and regulated on activation, normal T cells expressed and secreted (RANTES) have roles in GIL chemotaxis during lung allograft rejection. F344 (RT1(lv1)) rat lung allografts were transplanted into WKY (RT1(l)) recipients. Chemotactic activity for GILs and quantities of MCP-1 and RANTES were determined in allograft bronchoalveolar lavage fluid 1 wk after transplantation. Data showed that during rejection, chemotactic activity for GILs is upregulated, MCP-1 and RANTES are produced locally, and both MCP-1 and RANTES are operative in GIL recruitment. Immunohistochemistry showed that alveolar macrophages (AMs) were the major source of MCP-1 and that other lung cells, including AMs, were the source of RANTES. Further, depletion of AMs in the donor lung before transplantation downregulated chemotaxis for GILs and production of MCP-1 during rejection episodes. These data show that chemotaxis for GILs is upregulated locally during lung allograft rejection, and that MCP-1 and RANTES contribute to GIL recruitment during the rejection response.

Animals↗

The Canadian SCORE questionnaire: optimizing the use of technology for low bone density assessment. Simple Calculated Osteoporosis Risk Estimate.

The Simple Calculated Osteoporosis Risk Estimation (SCORE) questionnaire is a tool to assist physicians to identify women who might require bone densitometry. The purpose of this study was to develop a Canadian SCORE and to assess validity and reliability. Twenty sites enrolled 307 postmenopausal women ages 50-70 yr. SCORE results were compared to hip and lumbar spine bone density assessed by dual X-ray absorptiometry. Sensitivity and specificity of a range of SCORE cut-points were assessed in a receiver operating characteristics analysis to determine the optimal cut-point for SCORE. With low bone density defined as a T-score < or = -2.0, a SCORE cut-point of 6 in women ages 50-59 yr displayed a sensitivity of 0. 96, 95% confidence interval (CI) (0.89, 1.00), a specificity of 0.51, 95% CI (0.43, 0.58). In women ages 60-70 yr, a SCORE cut-point of 8 displayed a sensitivity of 0.90, 95% CI (0.80, 0.97) and a specificity of 0.20, 95% CI (0.11, 0.29). The test-retest reliability (intraclass correlation coefficient) was 0.95. SCORE performed better in women in their fifties than women in ther sixties. Older women require higher SCORE cut-points. The use of SCORE as an initial measure for identifying those at risk for osteoporosis may reduce costs by limiting unnecessary tests.

Absorptiometry, Photon↗

The optimal analgesic dose of rofecoxib: Overview of six randomized controlled trials.

BACKGROUND: Rofecoxib, which specifically inhibits cyclooxygenase-2, is indicated for relief of the signs and symptoms of osteoarthritis and for the management of acute pain in adults. The authors present an overview of six placebo-controlled trials designed to evaluate the single-dose analgesic efficacy of a range of doses of rofecoxib in the treatment of postoperative dental pain. METHODS: The six studies included doses of rofecoxib ranging from 7.5 to 500 milligrams. Maximal analgesic doses of a nonsteroidal anti-inflammatory drug, or NSAID, either naproxen sodium (550 mg) or ibuprofen (400 mg), were used as active comparators in each study. Analgesic efficacy was assessed with the use of validated self-administered questionnaires. The primary endpoint in each study was the total pain relief over the eight-hour postdose period. Additional endpoints were used to characterize the onset of analgesia and peak analgesic effect. RESULTS: The results of these studies demonstrated that the efficacy of rofecoxib was dose-related, with 50 mg being consistently more effective than placebo for all measures of analgesic efficacy. Moreover, 50 mg was the lowest dose that reproducibly demonstrated an analgesic effect comparable to the effect of maximum single analgesic doses of NSAIDs. CONCLUSION: The results of these studies support the recommended dose of 50 mg of rofecoxib once daily for the management of pain. CLINICAL IMPLICATIONS: Rofecoxib, at a dose of 50 mg, is effective in the management of postoperative dental pain.

Adolescent↗

Associations between four types of childhood neglect and personality disorder symptoms during adolescence and early adulthood: findings of a community-based longitudinal study.

Data from a community-based longitudinal study were used to investigate the association between childhood neglect and personality disorder (PD) symptom levels during adolescence and early adulthood. Psychosocial and psychiatric interviews were administered to a representative sample of 738 youths and their mothers from upstate New York in 1975, 1983, 1985-1986, and 1991-1993. Evidence of childhood cognitive, emotional, physical, and supervision neglect was obtained from the maternal interviews that were conducted in 1975, 1983, and 1985-1986, and from New York State records. PDs were assessed among the youths in 1985-1986, when they were adolescents, and in 1991-1993, when they were young adults. Findings indicated that childhood emotional, physical, and supervision neglect were associated with increased risk for PDs and with elevated PD symptom levels during adolescence and early adulthood, after age, sex, childhood physical or sexual abuse, other types of childhood neglect, and cooccurring PD symptoms were controlled statistically. Childhood emotional neglect was associated with increased risk for avoidant PD and with paranoid and Cluster A PD symptom levels during adolescence and early adulthood. Childhood physical neglect was associated with increased risk for schizotypal PD and with Cluster A PD symptom levels during adolescence and early adulthood. Childhood supervision neglect was associated with increased risk for passive-aggressive and Cluster B PDs and with borderline, paranoid, and passive-aggressive PD symptom levels during adolescence and early adulthood. The present findings suggest that childhood emotional, physical, and supervision neglect may play a role in the etiology of some PDs.

Adolescent↗

Strontium-90 in deciduous teeth as a factor in early childhood cancer.

Strontium-90 concentrations in deciduous (baby) teeth of 515 children born mainly after the end of worldwide atmospheric nuclear bomb tests in 1980 are found to equal the concentrations in children born during atmospheric tests in the late 1950s. Recent Sr-90 concentrations in the New York-New Jersey-Long Island metropolitan area have exceeded the expected downward trend seen in both baby teeth and adult bone after the 1963 ban on atmospheric testing. Sharp rises and declines are also seen in Miami, Florida. In Suffolk County, Long Island, Sr-90 concentrations in baby teeth were significantly correlated with cancer incidence for children 0 to 4 years of age. A similar correlation of childhood malignancies with the rise and decline of Sr-90 in deciduous teeth occurred during the peak years of fallout in the 1950s and 1960s. Independent support for the relation between nuclear releases and childhood cancer is provided by a significant correlation with total alpha and beta activities in local surface water in Suffolk County. These results strongly support a major role of nuclear reactor releases in the increase of cancer and other immune-system-related disorders in young American children since the early 1980s.

Child, Preschool↗

A pooled data analysis on the use of intermittent cyclical etidronate therapy for the prevention and treatment of corticosteroid induced bone loss.

OBJECTIVE: To conduct a pooled data analysis in a group of patients defined by sex, menopausal status, and underlying disease in order to examine the effect of intermittent cyclical etidronate in the prevention and treatment of corticosteroid induced osteoporosis. METHODS: We selected 5 randomized, placebo controlled studies that examined the efficacy of intermittent cyclical etidronate therapy in which the raw data were available for analysis. Three were prevention studies and 2 treatment studies. The primary outcome was the difference between treatment groups in the percentage change from baseline in lumbar spine bone density. Secondary outcomes included the difference between treatment groups in the percentage change from baseline in femoral neck and trochanter bone density, and vertebral fracture rates. RESULTS: Results are separately pooled for the prevention and treatment studies. The prevention studies had significant mean differences (95% CI) between groups in mean percentage change from baseline in lumbar spine, femoral neck, and trochanter bone density of 3.7 (2.6 to 4.7), 1.7 (0.4 to 2.9), and 2.8% (1.3 to 4.2) after one year of treatment, in favor of the etidronate group. The treatment studies displayed a mean difference between groups in mean percentage change from baseline in lumbar spine bone density of 4.8 (2.7 to 6.9) and 5.4% (2.5 to 8.4) after one and 2 years of therapy. In the prevention studies, a reduced fracture incidence was observed in the etidronate group compared with the placebo group (relative risk 0.50; CI 0.21 to 1.19). CONCLUSION: Etidronate therapy was effective in preventing bone loss in the prevention studies and in preventing or slightly increasing bone mass in the treatment studies. A fracture benefit was observed in postmenopausal women treated with etidronate in the prevention studies.

Adult↗

Improving adequacy of hemodialysis in Northern California ESRD patients: a final project report. Provider Participants and Medical Review Board of the TransPacific Renal Network.

The National Core Indicators Project, initiated in 1994, has brought progressive changes in adequacy of dialysis for end-stage renal disease (ESRD) patients in the TransPacific Renal Network and across the United States. The 1998 Core Indicator Project showed each Network's standing for percentage of patients with urea reduction ratio (URR) > or = 0.65 and average URR. The TransPacific Renal Network ranked 12(th) among the 18 Networks for this adequacy measure. The goals of this project were to improve the Network standing in the United States for the percent of patients with URR > or = 0.65, eliminate or reduce the barriers to achieving adequate dialysis, and evaluate URR versus KT/V data and the variances occurring with these measures. In January 1999, data were collected from all 113 Northern California hemodialysis facilities for quarter 4, 1998, to evaluate adequacy. Each facility provided patient population (N) for KT/V and URR samples, facility averages for KT/V and URR, number of patients with KT/V > or = 1.2 and URR > or = 0.65, and data on post-blood-urea-nitrogen (BUN) sampling methods. A random selection of 10% (12) providers with data below the US and Network standards was selected for an intensive assessment. Using baseline measurements, on-site data were collected from a random selection of the patient population. Chart data were reviewed, analyzed, and discussed in an exit interview with the facility management. On-site visits were performed in July/June 1999. The primary focus included adequacy data and process of care that affect adequacy outcomes, concurrent review of patients receiving treatment at the time of the site visit, and general medical record review. In Phase I, only 12 facilities showed an average URR below 0.65. All facilities reported an average KT/V greater than the DOQI target of 1.2. Forty-two facilities had their percentage of patients with a URR below the national benchmark; only 18 facilities had their percentage of patients with a KT/V below the national benchmark. Only 9% (n = 8) of the 113 providers had a variance in post-BUN sampling methodologies that could be related to the clinical measure of adequacy. In Phase II, a random selection of 12 providers with data below US and Network standards was made for an intensive assessment. A total of 217 patient records were reviewed from a population of 1,027. In addition to comparison of baseline data, each facility was assessed for barriers to achieving adequacy outcomes. The number of problems was extensive and specific to each facility; however, a common reoccurring theme in the majority of events was the lack of supporting documentation for changes to the plan of care when variances occur. The most common occurrences were incorrect blood flow and dialysate flow with no supporting documentation on record for the prescription not being met. In Phase III, Network interventions for facilities not meeting US and Network standards for adequacy as measured by URR and KT/V included required quarterly reporting on their facility-specific quality improvement programs for adequacy. In addition the 12 facilities that participated in the intensive assessment had additional interventions that included an educational "tool box" focused on documentation, legal implications of charting, and general medical records management, and an educational program to review information to be shared with facility staff. All on-site facilities reported ongoing quality improvement programs. In some facilities they did provide a focus on processes and not only a measurement of an indicator. All facilities reported a team concept of some type used in their program. Although there were similarities in the facilities, each facility presented with a unique combination of barriers. In addition to a large patient-to-RN ratio, the lack of technical education for the unlicensed assistive personnel on processes and outcomes appears to play a significant role in the achievement of

Ambulatory Care Facilities↗

Improved hepatitis B vaccination rates in ESRD patients in California.

According to the Centers for Disease Control (CDC) Survey of Dialysis Associated Diseases, California, which includes Network 17 and 18, had one of the lowest hepatitis B vaccination rates in the country for 1994, 1995, and 1996. With 3 outbreaks of hepatitis B (HBV) in California in 1994, hepatitis B vaccination was chosen as a quality improvement project in both Network 17 and 18. With input from both Medical Review Boards and HCFA Region X, a project was formulated which focused on the improvement of the number of facilities which had hepatitis B vaccination rates which are greater than 50%. The overall purpose of both projects was to: (1) achieve access to preventative services for end-stage renal disease (ESRD) Medicare beneficiaries; (2) increase the number of ESRD patients in California who are vaccinated for HBV; (3) eliminate dialysis in California as an independent risk factor for contracting HBV; (4) decrease the number of ESRD facilities with HBV vaccination rates of 0%; and (5) increase the number of ESRD facilities with HBV vaccination rates greater than 50%. In 1998, both Network 17 and 18 denominators were adjusted to reflect the population which is eligible for vaccination. Because of historically low vaccination rate in California, the 1998 data collection sought to ascertain precise numbers for the ESRD patient population. Data were used from the 1996 and 1997 CDC Survey of Dialysis Associated Diseases from baseline measurements of HBV vaccination rates for all facilities in both Network 17 and 18. The CDC did not conduct a survey in 1998, however, Network 17 and 18 conducted a survey of dialysis associated diseases for all of California ESRD facilities. A data collection tool was designed to gather information on processes and outcomes in each facility. This allowed a continuous quality improvement (CQI)-based approach to analyze the problem, where tools like cause/effect and Pareto diagrams provided information on factors and issues affecting low HBV vaccination rates. Interventions were designed to target those specific factors. Interventions included creation of the "Hepatitis Booklet" (Network 18) and the "Hepatitis Resource Guide" (Network 17); mailing of the resource material to all providers (Network 18), and with vaccination rates less than 50% (Network 17); development of facility specific profiles; and policy statements by both Medical Review Boards on Hepatitis B Vaccination. The number of ESRD patients in California who are vaccinated for HBV increased to 53% or 11,412 patients of 21,617 eligible patients in both Networks. The number of ESRD patients in California who are vaccinated plus those in the process of receiving the series brought the California vaccination rate of 72% or 15,653 for 21,617 eligible patients in both Networks. The number of ESRD facilities in California with HBV vaccination rates of 0% decreased to 10 facilities in 1998, from 75 facilities in 1997, and 135 facilities in 1996. The number of ESRD facilities in California with HBV vaccination rates more than 50% increased to 175 facilities, from 87 facilities in 1997, and 52 in 1996. The number of patients developing antibodies post-vaccine was 62% (Network 18). Facilities in Network 17 with vaccination rates exceeding 50% who did not receive the Hepatitis B Resource Guide vaccinated 44% of all patients vaccinated or in progress in Network 17 in 1998. Facilities in Network 17 with vaccination rates less than 50% who did receive the Hepatitis B Resource Guide vaccinated 57% of all patients vaccinated or in progress in Network 17. For the first time, vaccination rates were collected on peritoneal dialysis (PD) patients. In Network 17, 51% of PD patients are vaccinated versus 59% of hemodialysis patients. In Network 18, 48% of PD patients are vaccinated versus 48% of hemodialysis patients. Resource material and feedback reports developed by both Networks facilitated improvements in Hepatitis B vaccination of ESRD patients in Ca

California↗

For whom is the Caesarean section rate high?

AIM: To define a method for examining and comparing Caesarean section rates. METHODS: Data on Caesarean section rates at National Women's Hospital for 1997 were analysed by two methods which adjust Caesarean section rates according to casemix: 1. standard nulliparae and 2. grouping women by factors influencing Caesarean section rates. RESULTS: The Caesarean section rate in New Zealand is rising and National Women's Hospital had a Caesarean section rate of 22.3% in 1997. The instrumental vaginal delivery rate was 13.1%. Our 1997 data were analysed for casemix -- standard nulliparae and dividing women into six distinct groups. The Caesarean section rate for standard nulliparae was 19.2%. Nulliparae had an increased induction of labour rate compared to multiparae (29.1% versus 22.9%, p < 0.001). The Caesarean section rate was increased in association with induction of labour for nulipare (26.0% versus 13.1%, p < 0.001), multiparae with unscarred uteri, (5.4% versus 2.5%, p < 0.001) and primiparae with previous caesareans (36.8% versus 30.4%, p = 0.02) CONCLUSION: We suggest our second method of grouping women by the most important factors influencing intervention rates should be used by obstetric units for benchmarking and internal audit purposes.

Adult↗

How the basal ganglia use parallel excitatory and inhibitory learning pathways to selectively respond to unexpected rewarding cues.

After classically conditioned learning, dopaminergic cells in the substantia nigra pars compacta (SNc) respond immediately to unexpected conditioned stimuli (CS) but omit formerly seen responses to expected unconditioned stimuli, notably rewards. These cells play an important role in reinforcement learning. A neural model explains the key neurophysiological properties of these cells before, during, and after conditioning, as well as related anatomical and neurophysiological data about the pedunculopontine tegmental nucleus (PPTN), lateral hypothalamus, ventral striatum, and striosomes. The model proposes how two parallel learning pathways from limbic cortex to the SNc, one devoted to excitatory conditioning (through the ventral striatum, ventral pallidum, and PPTN) and the other to adaptively timed inhibitory conditioning (through the striosomes), control SNc responses. The excitatory pathway generates CS-induced excitatory SNc dopamine bursts. The inhibitory pathway prevents dopamine bursts in response to predictable reward-related signals. When expected rewards are not received, striosomal inhibition of SNc that is unopposed by excitation results in a phasic drop in dopamine cell activity. The adaptively timed inhibitory learning uses an intracellular spectrum of timed responses that is proposed to be similar to adaptively timed cellular mechanisms in the hippocampus and cerebellum. These mechanisms are proposed to include metabotropic glutamate receptor-mediated Ca(2+) spikes that occur with different delays in striosomal cells. A dopaminergic burst in concert with a Ca(2+) spike is proposed to potentiate inhibitory learning. The model provides a biologically predictive alternative to temporal difference conditioning models and explains substantially more data than alternative models.

Animals↗

Follow-up recommendations for patients with American Joint Committee on Cancer Stages I-III malignant melanoma.

BACKGROUND: Guidelines for follow-up of melanoma patients are not established. In 1987, a follow-up protocol was instituted at the Yale Melanoma Unit to improve upon the detection of disease recurrence in patients with American Joint Committee on Cancer Stage I-III cutaneous melanoma. The follow-up protocol consists of a patient education program and a surveillance schedule based on stage of disease. METHODS: The authors retrospectively reviewed the records of 373 patients who were seen and followed according to the surveillance protocol in the Yale Melanoma Unit between January 1988 and December 1994 to determine 1) the time interval between the initial visit and recurrence; 2) the most common method of detecting recurrences; 3) whether the surveillance schedule or the patient detects more recurrences, i.e., asymptomatic recurrences versus symptomatic recurrences; 4) whether there is any survival difference between asymptomatic and symptomatic recurrences. RESULTS: The 5-year overall survival rates for Stage I, II, and III patients were 95%, 72%, and 52%, respectively. Of the 78 recurrences, 44 (56%) were detected by physician-directed surveillance examinations and 34 (44%) by patients. Most recurrences were found within the first (47%) or second (32%) year of follow-up. The estimated 6-month hazard rates for death or recurrence were 0.0044, 0.0088, and 0.0278 for Stage I, II, and III patients, respectively. The group of asymptomatic patients with recurrence had a survival advantage over the symptomatic recurrence group. In addition, patients with locoregional recurrence had better survival than those with distant recurrence. CONCLUSIONS: Although many recurrences arise rapidly and are recognized early by patients, in this study more than half were found by surveillance examinations before symptoms were manifest. Based on the hazard ratio for recurrences, the authors recommend the following surveillance schedules in addition to the patient education program for detection of recurrences: 1) Stage I, annually; 2) Stage II, every 6 months for Years 1-2 and annually thereafter; 3) Stage III, every 3 months for Year 1, every 4 months for Year 2, and every 6 months for Years 3-5; 4) at Year 6 and beyond, all patients should have surveillance annually, due to the risk of late recurrence and/or metachronous multiple primaries.

Adolescent↗

Controlled Formation of Low-Volume Liquid Pillars between Plates with a Lattice of Wetting Patches by Use of a Second Immiscible Fluid.

We describe a method for forming an array of microdroplets between two plates, at least one of which is patterned with a lattice of wetting patches, using a second immiscible fluid to control droplet formation. The method may be useful for performing multiple, small-volume biochemical reactions in parallel. We analyze the forces responsible for droplet formation, describe results of a computer simulation using Surface Evolver, and derive an analytic criterion for droplet formation in terms of the contact angles of the droplet:second fluid interface on the wetting patches and surrounding surface, the diameter of the wetting patches, the distance between wetting patches, and the distance between the plates. Copyright 1999 Academic Press.

Journal Article↗

Two view mammography at incident screens: cost effectiveness analysis of policy options.

OBJECTIVE: To determine the cost effectiveness of two view mammography at incident screens. DESIGN: Incremental cost effectiveness analyses recognising differences in current reading policy, based on effectiveness data from an observational study. SETTING: Breast screening programmes in England and Wales. MAIN OUTCOME MEASURES: Health service costs, cancers detected, incremental cost effectiveness ratios per cancer detected, whole time equivalent staff. RESULTS: For programmes currently using one view with some form of double reading, the incremental cost effectiveness ratio of two view mammography at incident screens ranged between 6589 pounds and 6716 pounds, depending on the reading policy. For programmes currently using one view with single reading, two policy options were found to be more efficient than two view single reading: one view with double reading (arbitration; incremental cost effectiveness ratio of 210 pounds) and two view double reading (arbitration). If programmes using one view with single reading changed to double reading (arbitration) and then subsequently to two views double reading (arbitration), additional cancers could be detected with an incremental cost effectiveness ratio of 7983. The implementation cost of two view mammography at incident screens in programmes in England and Wales would be 2.9 million pounds and would require 13.4 whole time equivalent radiologists. CONCLUSIONS: The cost effectiveness of two view mammography at incident screens depends on the film reading policy. A policy of two view mammography at incident screens in England and Wales would be efficient only if programmes using single reading moved to double reading. Given limited resources, priority should be given to introducing double reading in the subset of programmes currently using single reading as this requires fewer additional radiologists and is more cost effective.

Breast Neoplasms↗