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PubMed2006

Nucleotide excision repair genotype and the incidence of endometrial cancer: effect of other risk factors on the association.

OBJECTIVES: Certain nucleotide excision repair (NER) genotypes appear to be associated with an altered risk of endometrial cancer. These associations could be modified by characteristics and exposures that themselves influence risk of disease. METHODS: We conducted a population-based case-control study in western Washington State to address the role of specific NER genotypes in conjunction with relevant exposures, such as postmenopausal hormone therapy, obesity, parity, oral contraceptive use, and cigarette smoking on risk of endometrial cancer. Case women (n=371), ages 50-69 years, were diagnosed with invasive endometrial cancer between 1994 and 1999. Control women (n=420), matched to cases on age and county of residence, were selected using random-digit dialing (ages 50-65) and random selection from HCFA data files (ages 66-69). RESULTS: Risk of endometrial cancer was not associated with ERCC1, ERCC2 (XPD), ERCC4 (XPF), or ERCC5 (XPG) genotype. A reduced risk of endometrial cancer was observed with presence of the XPA g23a variant allele, but only among women with a history of oral contraceptive use (OR 0.47, 95% CI 0.32-0.69). A decreased risk associated with carriage of at least one variant allele for both XPC A499V and XPC K939Q was restricted to women with BMI<30 kg/m2 (OR 0.45, 95% CI 0.25-0.82). The size of the association between these genotypes and risk of endometrial cancer did not differ by postmenopausal hormone use, parity, or smoking. CONCLUSIONS: Our study provides limited evidence for interactions between NER genotypes and DNA damage-causing exposures in the etiology of endometrial cancer. Subsequent studies are needed to confirm the observed associations.

Aged↗
PubMed2001

Prospective studies of the safety of acupuncture: a systematic review.

PURPOSE: The objective of this review was to determine the incidence of adverse events associated with acupuncture. SUBJECTS AND METHODS: A search for prospective surveys of the safety of acupuncture was conducted using computerized databases (Medline, Embase, the Cochrane Library, and CISCOM), inquiries to acupuncture organizations, and our own files. Data on sample, size, types of patients duration of study, types of acupuncture, definition of adverse events, method of evaluation, and findings were extracted systematically from the retrieved reports. RESULTS: Nine surveys were located and included in the review. Their results were not uniform. The most common adverse events were needle pain (1% to 45%) from treatments, tiredness (2% to 41%), and bleeding (0.03% to 38%). Feelings of faintness and syncope were uncommon, with an incidence of 0% to 0.3%. Feelings of relaxation were reported by as many as 86% of patients. Pneumothorax was rare, occurring only twice in nearly a quarter of a million treatments. CONCLUSIONS: Although the incidence of minor adverse events associated with acupuncture may be considerable, serious adverse events are rare. Those responsible for establishing competence in acupuncture should consider how to reduce these risks.

Acupuncture Therapy↗
PubMed1993

Palliative operations for pancreatic cancer in the hospitals of the U.S. Department of Veterans Affairs from 1987 to 1991.

A total of 1,180 patients underwent palliative surgery for pancreatic cancer in the 158 hospitals of the U.S. Department of Veterans Affairs from 1987 to 1991. Using computerized data files, we analyzed these procedures according to type of procedure (gastric bypass only [GO], biliary bypass only [BO], or combined biliary and gastric bypass [BG]), survival, reoperation and complication rates, patient age, and operative (30-day) mortality. Survival after GO (208 days) was significantly shorter than after BO or BG (279 days and 259 days, respectively; p < or = 0.05 by analysis of variance). The reoperation rate after BO (12%) was higher than after BG (5%; p < or = 0.001 by chi 2 analysis) and was due to the higher incidence of reoperative gastric bypass in the BO group. Complication rates were similar after all bypass types. Reoperations had a 25% 30-day mortality. The 32 gastric bypasses performed after an initial BO were done at a mean of 193 days after the original BO bypass, whereas other reoperations were undertaken at a mean of 73 days after the first operation. This first national study of palliative operations for pancreatic cancer supports combined biliary/gastric bypass as the initial procedure, thus minimizing reoperations and their attendant morbidity.

Aged↗
PubMed1997

Detection of spontaneous synaptic events with an optimally scaled template.

Spontaneous synaptic events can be difficult to detect when their amplitudes are close to the background noise level. Here we report a sensitive new technique for automatic detection of small asynchronous events. A waveform with the time course of a typical synaptic event (a template) is slid along the current or voltage trace and optimally scaled to fit the data at each position. A detection criterion is calculated based on the optimum scaling factor and the quality of the fit. An event is detected when this criterion crosses a threshold level. The algorithm automatically compensates for changes in recording noise. The sensitivity and selectivity of the method were tested using real and simulated data, and the influence of the template parameter settings was investigated. Its performance was comparable to that obtained by visual event detection, and it was more sensitive than previously described threshold detection techniques. Under typical recording conditions, all fast synaptic events with amplitudes of at least three times the noise standard deviation (3 sigma) could be detected, as could 75% of events with amplitudes of 2 sigma. The scaled template technique is implemented within a commercial data analysis application and can be applied to many standard electrophysiological data file formats.

Animals↗
PubMed1999

How to achieve higher repeatability and reproducibility in capillary electrophoresis.

The influence of experimental parameters on precision of migration times and accuracy of integration has been studied. The repeatability of migration times strongly depends on the proper selection of the rinse steps between each run of a CE system. The rinse steps have to be optimized additionally with each separation system. This is especially important for systems providing an anodic electroosmotic flow. The errors introduced by the integration software were studied by transferring the same data sets to different commercial available integration softwares. A strategy for the transfer of raw data files between several softwares is described. By using systems with identical peak areas or with identical peak heights it could be shown that the newly introduced softwares can cope better with the leading or tailing peaks. The RSD of quantitation strongly depends on the signal-to-noise ratio. At S/N ratios larger than 35 no differences between the various softwares studied could be observed. At lower S/N ratios the newly released softwares are to be preferred.

Electrophoresis, Capillary↗
PubMed1989

The signal-averaged electrocardiogram and late potentials. A comparative analysis of commercial devices.

The authors used two separate protocols to compare four commercially available devices for recording of the signal-averaged electrocardiogram and "late potentials" to assess their degree of concordance in identifying abnormalities. In one protocol, studies were performed using each system. In 19% of recordings the results from one system were discordant in at least one numeric parameter. In the second protocol identical averaged data files were used to identify discordancies due solely to differences in analysis algorithms used for QRS offset determination by the various devices. This disclosed 23% discordant findings, mostly in the root mean square amplitude of the terminal 40-msec segment resulting from small differences in the estimate of QRS offset point. To improve concordance between commercial systems, there is an urgent need for adoption of a rigorously standardized algorithm for analysis of baseline noise and QRS offset.

Action Potentials↗
PubMed1995

Acuity scores as predictors of cost-related outcomes of neonatal intensive care.

OBJECTIVE: The Medicus Patient Classification System (PCS) and the lameter Acuity Index Method (AIM) are two proprietary scoring systems in common use for stratifying patient populations before making comparisons of the medical care they receive. In this study the validities of these scores were tested when the scores were used to evaluate cost-related elements of high-risk neonatal intensive care. METHODS: A total of 687 surviving inborn infants cared for in a university hospital newborn intensive care unit provided data for these analyses. The infants were stratified into the five diagnosis-related groups (DRGs) for surviving neonates (386, 387, 388, 389, and 390), as determined from their discharge diagnoses. Each infant's summed total of daily PCS scores, a single AIM score, and birth weight were extracted from the hospital's decision-support data files and used as independent variables in regression analyses to determine correlations with lengths of hospital stay, ancillary resource utilizations, and hospital charges. RESULTS: The Medicus scores, which are computed prospectively on a daily basis, when summed retrospectively, correlated highly with lengths of stay, ancillary resource utilization, and associated hospital charges. The lameter scores, which are assigned retrospectively, were far less predictive of these outcome variables and generally worse than birth weight in explaining outcome variances. CONCLUSIONS: Although in common use, the lameter AIM could not be validated as an appropriate method for assessing cost-related outcomes after newborn intensive care. The Medicus PCS produced daily scores that, when summed after patient discharge, correlated highly with the same outcome variables. There is a need to test further these and other proprietary methods now used to compare the cost-related elements of care provided by different hospitals and physicians.

Birth Weight↗
PubMed1996

Cost of patient follow-up after potentially curative lung cancer treatment.

The two objectives of this study were to determine the range of recommended follow-up strategies for patients with lung cancer treated with curative intent and to estimate the cost of such follow-up. Ten articles delineating eight specific follow-up strategies were identified from a Medline search of the literature for 1980 through 1995. An economic analysis was done of the costs associated with the identified strategies. Charge data obtained from the Part B Medicare Annual Data file and the Hospital Outpatient Bill file were used as a proxy for cost. Follow-up intensity varied widely across strategies for 5 years of posttreatment follow-up. Medicare-allowed charges for 5-year follow-up ranged from a low of $946 to a high of $5645. When Medicare-allowed charges were converted to a proxy for actual charges by a conversion ratio of 1.62, the range was $1533 to $9145, a fivefold difference in charges. There was no indication that more intensive, higher-cost strategies increased survival or quality of life. The published literature, including textbooks, holds few answers in this area.

Blood Chemical Analysis↗
PubMed1998

Standards of birth weight in twin gestations stratified by placental chorionicity.

OBJECTIVE: To establish fetal growth nomograms for twin gestations, categorized by placental chorionicity, and to compare them with those of published singleton and twin nomograms. METHODS: Computerized data files of live births of all twins delivered between January 1990 and October 1996 at Saint Peter's Medical Center were used. Birth weight curves corresponding to the fifth, tenth, 50th, 90th, and 95th percentiles were derived separately for twins with monochorionic and dichorionic placentation. We generated the curves by applying the method of generalized estimating equations, after adjusting for the potential intracluster correlation due to twinning. The curves were then smoothed on the basis of nonparametric restricted cubic splines to derive (smoothed) birth weight percentiles. We then compared our twin birth weight nomogram to six previously published singleton and two twin nomograms published previously for predicting small for gestational age infants (defined as birth weight below the tenth percentile). RESULTS: Among 1302 twin fetuses, 272 (21%) were monochorionic. Twins from monochorionic gestations weighed, on average, 66.1 g (standard deviation 28.4 g, P = .02) less than twins from dichorionic gestations after correcting for gestational age. Twin curves based on parity (nulliparity versus multiparity) were not different from each other. Analyses indicate that all previously published singleton nomograms approximate twin growth reasonably well between 32 and 34 weeks, but they underestimate twin growth at earlier gestational ages (between 25 and 32 weeks) and overestimate twin growth beyond 34 weeks' gestation. Similarly, a comparison of previously published twin nomograms with those of ours indicates that the growth standards in our population were similar to those in other published twin nomograms. CONCLUSION: We recommend that future epidemiologic and clinical studies use twin nomograms to identify growth-restricted twin fetuses. Moreover, because fetal growth is influenced by placental chorionicity, we recommend that fetal growth assessment in twin gestations consider placental chorionicity, whenever the information is available.

Birth Weight↗
PubMed1996

Excess mortality of unemployed men and women during a period of rapidly increasing unemployment.

BACKGROUND: Previous studies have found evidence of higher mortality rates among unemployed people than among those in employment, but the effect of changes in national unemployment rates on this association is unclear. We studied mortality in both men and women during a period of rapidly increasing unemployment in Finland. METHODS: In this prospective study of mortality in the Finnish population aged 25-59 years (2.5 million people), baseline sociodemographic data were obtained from the 1990 census and information on employment status in 1987-92 from Statistics Finland's labour force data files. Mortality follow-up was established by record linkage to death certificates from 1991 to 1993. FINDINGS: Individuals who experienced unemployment between 1987 and 1992 had greater mortality than those in employment after control for age, education, occupational class, and marital status. The mortality ratios for men and women unemployed for the first time in 1990, at a time of low national unemployment were 2.11 (95% CI 1.76-2.53) and 1.61 (1.09-2.36), respectively. These values were lower for those who were unemployed for the first time in 1992 when the national unemployment rate was very high (men 1.35 [1.16-1.56], women 1.30 [0.97-1.75]). The jobless who were re-employed had higher mortality than those who were continuously employed, but not as high as those who remained unemployed. INTERPRETATION: We have found that the association between unemployment and mortality weakens as the general unemployment rate increases. Studies that took place when the unemployment rate was low may thus overestimate the effect of unemployment on mortality because of unaccounted confounding.

Adult↗
PubMed1997

Applications of multimedia computers and video mixing to neuroethology.

Inexpensive multimedia computers offer new possibilities for mixing video and computer images, videotaping these mixed images, and extracting quantitative data from videotape. In this paper we describe methods for mixing images from a video camera and a Macintosh computer display using chroma keying, and we describe a simple circuit for analog video mixing and frame-counting. We present three applications of these video mixing methods to our neurophysiological and behavioral research with awake, behaving animals. These technologies enhance accuracy, speed, and flexibility during experiments, by allowing us to record an information-rich videotape of the subject and state of the experimental apparatus. After the experiment, these technologies facilitate selecting and extracting quantitative data from the videotape for further analysis. The videotape is especially useful in resolving minor inconsistencies or incomplete information in the notes and data files that often arise during analysis of complex experiments.

Animals↗
PubMed2002

A review of approaches to quality assurance of veterinary systems for health-status certification.

Regarding national and international trade of animals and animal products, certificates are required to document specific health levels. The credibility of such certificates depends on the quality of the data used to establish the status. Credibility also depends on the quality of the design and protocols used in the data-gathering process (i.e. on the quality of the surveillance-and-monitoring systems (SMS) and on the quality of the veterinary administrative systems (VAdminS)). The major requirements for the assessment of the SMS and VAdminS are: objectivity, accuracy, transparency, practicality, quantitative in nature. To assess the quality of SMS and VAdminS, systems analysis might provide a suitable framework. Systems analysis requires the identification and description of all components of the system-how they interact with each other and with other systems. Graphical methods (e.g. fault trees) are available to support this procedure. To assess the quality of SMS, scoring systems have been suggested. Their main weakness is the inherent subjectiveness. Alternatively, performance indicators (PI) could be used. For the assessment of VAdminS, questionnaires have been developed and applied. Their main limitations are that they focus on the input rather than on the output and that they are purely descriptive in nature. Thus, comparisons between countries are almost impossible. Semi-quantitative questionnaires using scores now are being developed and tested, although their limitations will be similar to those mentioned above. Another approach is the use of risk assessment including standardised data files assembled by countries volunteering to be assessed. This was applied successfully by the European Union (EU) in the geographic risk assessment for bovine spongiform encephalopathy (BSE). In general, the publication and documentation of veterinary systems needs to be encouraged to make them accessible to peer review.

Animal Diseases↗
PubMed1999

Teleconsultation in otolaryngology: live versus store and forward consultations.

OBJECTIVE: To evaluate the relative strengths and weaknesses of interactive and delayed teleconsultations in otolaryngology. SETTING: Ambulatory clinic at an urban tertiary care facility. SUBJECTS: Forty-five adult patients with known or suspected upper aerodigestive tract pathology. INTERVENTION: Patients were interviewed by an otolaryngology chief resident (CR) using a standardized protocol; the results were presented to a board-certified otolaryngologist present locally (LBCO) and a remote physician viewing the encounter by video-conferencing elsewhere in the hospital (RBCO). The CR performed a complete otolaryngologic examination, including fiberoptic nasopharyngolaryngoscopy. The CR and LBCO viewed the examination on a video monitor; the RBCO viewed the same image on the video-conferencing monitor. Each physician independently recorded findings and rendered a diagnosis. A third board-certified otolaryngologist, who reviewed the stored data file (text and stored images) in a delayed fashion (DBCO), documented his findings and made a diagnosis. RESULTS: The CR and LBCO agreed on diagnosis in 92% (36 of 39) of cases. The LBCO and RBCO arrived at the same diagnosis in 29 of 34 (85%) cases. The DBCO agreed with the LBCO for 18 of 28 (64%) diagnoses. Agreement on management recommendations between the LBCO/DBCO pair were also lower than for the LBCO/RBCO pair. CONCLUSIONS: Both interactive and delayed techniques can be used to provide relatively accurate clinical consultations in otolaryngology. Telemedicine can be applied for subspecialty consultations, screening programs, remote emergency triage, second opinions, and resident education.

Adult↗
PubMed1990

Results of renal replacement therapy in Europe, 1980 to 1987. Registration Committee of the EDTA-ERA.

The characteristics of the patient populations accepted for and undergoing renal replacement therapy (RRT) in Europe in 1980 to 1987 are presented. Acceptance rates have increased in most countries reporting to the EDTA Registry and have reached from between 50 to over 80 per million population in the more affluent Western European countries in 1987. Increasing acceptance rates were due to the inclusion of patient groups at a higher risk of dying, such as the elderly and those with diabetic nephropathy. Despite the acceptance of a growing proportion of high-risk patients, no increase in overall mortality was apparent. Gross mortality (some 10% annually) changed little between 1980 and 1987 for patients on hemodialysis, decreased sharply from 1980 to 1984 for patients on continuous ambulatory peritoneal dialysis (CAPD), and improved continuously from 4.2% in 1980 to 2.4% in 1987 for patients with a functioning kidney graft. In order to determine mortality more accurately, actuarial survival rates and annual death rates per thousand patient years at risk were computed according to age groups and to primary renal disease groups, both for the total patient data file and for selected countries. Actuarial 5-year survival on hemodialysis for all patients starting treatment between 1982 and 1987 varied according to age, being 84% in patients age 15 to 24 years and 20% in those age 75 to 84 years. Patients with "standard" primary renal diseases had slightly better survival, while of the group with diabetic nephropathy only 51% age 25 to 34 and no more than 3% of those age 75 to 84 survived the 5-year mark. To recognize trends in the mortality between 1980 and 1987, annual death rates for all patients on record, age 45 to 54 and 55 to 64 at the beginning of 1980, 1983, 1985, and 1987 were computed both for the total Registry and for the FRG. Despite an increasing acceptance rate of patients with diabetic nephropathy, the annual death rates on hemodialysis decreased or remained stable both for the total Registry and for the FRG. Death rates in patients with a functioning graft decreased. It is concluded that, during the last decade, survival on RRT has continued to improve not only because of decreasing mortality after transplantation and on CAPD, but also due to improving survival on hemodialysis. The latter is not readily apparent because of the increasing acceptance rate in older patient groups and a rapidly rising proportion of patients with diabetic nephropathy in most European countries.

Adolescent↗
PubMed2000

Biomass Production System (BPS) plant growth unit.

The Biomass Production System (BPS) was developed under the Small Business Innovative Research (SBIR) program to meet science, biotechnology and commercial plant growth needs in the Space Station era. The BPS is equivalent in size to a double middeck locker, but uses its own custom enclosure with a slide out structure to which internal components mount. The BPS contains four internal growth chambers, each with a growing volume of more than 4 liters. Each of the growth chambers has active nutrient delivery, and independent control of temperature, humidity, lighting, and CO2 set-points. Temperature control is achieved using a thermoelectric heat exchanger system. Humidity control is achieved using a heat exchanger with a porous interface which can both humidify and dehumidify. The control software utilizes fuzzy logic for nonlinear, coupled temperature and humidity control. The fluorescent lighting system can be dimmed to provide a range of light levels. CO2 levels are controlled by injecting pure CO2 to the system based on input from an infrared gas analyzer. The unit currently does not scrub CO2, but has been designed to accept scrubber cartridges. In addition to providing environmental control, a number of features are included to facilitate science. The BPS chambers are sealed to allow CO2 and water vapor exchange measurements. The plant chambers can be removed to allow manipulation or sampling of specimens, and each chamber has gas/fluid sample ports. A video camera is provided for each chamber, and frame-grabs and complete environmental data for all science and hardware system sensors are stored on an internal hard drive. Data files can also be transferred to 3.5-inch disks using the front panel disk drive.

Air Conditioning↗
PubMed2000

An independent dose-to-point calculation program for the verification of high-dose-rate brachytherapy treatment planning.

PURPOSE: We describe computer software that performs, quickly and accurately, secondary dose calculations for high-dose-rate (HDR) treatment plans, including those employed for prostate treatments. METHODS: The program takes as primary input the data file used by the HDR remote afterloader console for treatment. Dosimetric calculations are performed using the Meisberger polynomial and the anisotropy table for the HDR Iridium-192 source. For standard applicators, treatment geometry is automatically reconstructed and the dose is calculated at relevant reference point(s). Template-based treatment plans (e.g., prostate) require additional user input; the dose calculation is then performed at user-selected reference points. A total dwell time calculation for volume and planar implants using the Manchester tables was also implemented. RESULTS: For fixed-geometry HDR procedures, secondary dose calculations are within 2% of the treatment plan, and results are available for review instantly. For more general applications, the calculated and planned doses are typically within 3% at the prescription isodose line. The Manchester-based dwell time calculation is within 10% of the planned time.

Algorithms↗
PubMed2001

Early onset and recent drug use among children of parents with alcohol problems: data from a national epidemiologic survey.

There is good evidence that children of parents with alcohol problems have more drug involvement, plus related mental health and behavioral problems. In this study, we sought to estimate the degree to which these children might be more likely to initiate drug use precociously. A sample of 2888 parent-child pairs was identified within public data files of the National Household Survey on Drug Abuse (NHSDA), 1995-1997. Alcohol dependence of one parent was assessed by that parent's report of three or more dependence manifestations. Independently, one randomly selected 12-17 year-old child of the parent answered self-report survey questions on age at first use of tobacco, alcohol, and marijuana. In analyses contrasting 114 children of alcohol dependent parents (AD+) with 2774 other children (AD-), youths with alcohol dependent parents had higher odds than other kids to have used tobacco in the past year (odds ratio, OR=3.2, 95% confidence interval, CI=2.05-4.98), as well as alcohol (OR=1.6, 95% CI=1.05-2.50), and marijuana (OR=2.9, 95% CI=1.71-4.90). Survival analyses were used to clarify excess risk of early-onset drug use. For example, by age 17, an estimated 73% of AD+ children had smoked tobacco cigarettes, 70% had started drinking, and 41% had smoked marijuana, versus 44%, 57%, and 26% of AD- children, respectively. This new evidence helps build a case that children of parents with alcohol problems experience precocious drug use.

Adolescent↗
PubMed2002

Pherogram normalization in capillary electrophoresis and micellar electrokinetic chromatography analyses in cases of sample matrix-induced migration time shifts.

When analyzing bio-matrix samples using capillary electrophoresis (CE) or micellar electrokinetic chromatography (MEKC), unwanted shifts in the time axis are often observed, both between samples and standards and between samples, thus hampering identification. These shifts are caused by either or both of two sample matrix-induced effects: variations in stacking conditions (effective field strength or migration length) and variations in electroosmotic flow. Based on elementary CE principles and provided that any two peaks in the pherograms can be linked, these variations can be separately accounted and quantitatively corrected for, so that perfectly overlapping pherograms of standards and samples can be obtained after normalization. The method was validated using samples of a DNA ladder, separated in a sieving polymer. In addition, a number of data files from CE and MEKC analyses (steroids, opioids, beta-blockers, amines, and inorganic anions) previously published by other authors were successfully normalized. A freeware computer programme, CEqualizer, for normalizing ASCII files of detector signals using the method described, is available to the CE community from http: //www.ceyork.f2s.com.

Chromatography, Micellar Electrokinetic Capillary↗