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PubMed2005

Peristat: a computer-based perimetry self-test for cost-effective population screening of glaucoma.

PURPOSE: Peristat is a virtual perimetry system that allows self-testing on any standard computer monitor via Internet connection. The sensitivity and specificity of Peristat to detect visual-field defects were compared to standard Humphrey Visual Field Analyzer data. MATERIALS AND METHODS: In this prospective, comparative observational case series, 58 eyes of 33 patients were examined. Semiquantitative analyses compared Peristat and Humphrey Visual-Field scores. The study evaluated patients with an established glaucoma diagnosis, as well as glaucoma suspects who had undergone comprehensive ophthalmologic examinations including prior office perimetry evaluation (Humphrey Field Analyzer). Inclusion criteria were (1) diagnosis or suspicion of glaucoma, (2) BCVA better than 20/200, (3) reliable performance on prior standardized office perimetry, and (4) CDR greater than 0.5. Computer literacy was not required, and more than 40% of the patients tested were computer illiterate, with no previous computer or Internet experience. A total of 58 eyes of 33 patients were tested with the Humphrey and the Peristat systems: 10 eyes of 5 patients without documented glaucomatous field loss and 48 eyes of 23 patients with mild-to-severe scotomas by standard 24-2 office perimetry. A standard computer setup was used with a 17" monitor, and the Peristat system was enabled through a remote connection with a server. RESULTS: All patients completed the Peristat test without difficulty. Testing time varied between 2 and 5 min, tending to be longer with more severe visual-field defects. Test results were reviewed, in a masked fashion, by two glaucoma specialists and one general ophthalmologist. The Peristat demonstrated a high degree of correlation with the Humphrey system. Among the three reviewers, sensitivity ranged from 80% to 83%. In a second subanalysis in which cases with mild defects were excluded, the Peristat's sensitivity increased to 84%-86% while specificity remained between 94% and 97% for all three reviewers. Patients performed the Peristat test with similar facility to their Humphrey test. Fixation losses and test reliability were comparable for both tests. CONCLUSIONS: Peristat is a reliable self-test perimetry system that demonstrates high clinical utility for the detection of visual-field defects from glaucoma. Peristat could be a valuable public health tool for cost-effective screening of glaucoma.

Algorithms↗
PubMedDate not supplied

[Scaphoid percutaneous osteosynthesis by screw using computer assisted surgery: an experimental study].

Scaphoid fractures are sometimes difficult to diagnose and even more difficult to fix. Recent progress such as miniaturization of osteosynthesis material, adoption of the percutaneous route, and widening of the indications to include undisplaced fractures has still not abolished complications. In this context, computer assisted surgery (CAS) may be useful and deserves further study. To apply it to the scaphoid, it is initially necessary to immobilize the "wrist hand fingers" unit in a device adapted to make it a rigid unit. It is then necessary to choose the correct configuration of CAS system. The pedicular fluoroscopic navigation system, which is apparently similar to scaphoid screw insertion, was chosen for this study. The goal of this study is to define the osteosynthesis bases of the scaphoid with CAS. A fresh anatomical subject divided at the elbow joint was prepared at the DETERCA laboratory of the university Bordeaux 2. The solid "wrist hand fingers" unit was immobilized in extension and ulnar deviation of the wrist by a malleable, stable and radio transparent device. The first stage consisted of a calibration of the surgical instruments and the "wrist hand fingers" unit, with a three-dimensional optical localization system. The guide wire was simulated by a gauged stylet. When the axis and the length of the screw had been determined virtually, insertion of the guide wire was carried out under guidance of the virtual images of the computer's screen, without the assistance of the fluoroscopy. Finally the canulated screw was inserted over the guide wire. Insertion was stopped when the screw reached the intra osseous virtually predetermined length. A check using conventional fluoroscopy made it possible to ensure the correct positioning of the screw. Our results show that it is possible to insert a screw into a scaphoid without conventional fluoroscopy, by using the fluoroscopic navigation system. The procedure was performed without difficulty, apart from the need for calibration of the navigation tools one by one. The solid immobilization device, although having the potential for micromovement, did not lead to any misdirection of the guide wire or screw. Our technique cannot be employed at the moment in live human surgery. Its limits are of a geometrical nature "two images available in two planes", data processing "non-specific software dedicated", instrumental "instrument calibration, micromobility of the immobilisation device" and live surgery "no current validation on a fractured scaphoid". Meantime, the development of a percutaneous scaphoid osteosynthesis procedure by CAS can only bring advantages: reduction in the learning curve, widening of the indications, comfort in the technique, reduction in the errors of ostesynthesis and, reduction in the exposure to x-rays. In the current state of knowledge, the method would only be applicable to undisplaced fractures.

Bone Screws↗
PubMed2003

Principles and advantages of robotics in urologic surgery.

Although the available minimally invasive surgical techniques (ie, laparoscopy) have clear advantages, these procedures continue to cause problems for patients. Surgical tools are limited by set axes of movement, restricting the degree of freedom available to the surgeon. In addition, depth perception is lost with the use of two-dimensional viewing systems. As surgeons view a "virtual" target on a television screen, they are hampered by decreased sensory input and a concurrent loss of dexterity. The development of robotic assistance systems in recent years could be the key to overcoming these difficulties. Using robotic systems, surgeons can experience a more natural and ergonomic surgical "feel." Surgical assistance, dexterity and precision enhancement, systems networking, and image-guided therapy are among the benefits offered by surgical robots. In return, the surgeon gains a shorter learning curve, reduced fatigue, and the opportunity to perform complex procedures that would be difficult using conventional laparoscopy. With the development of image-guided technology, robotic systems will become useful tools for surgical training and simulation. Remote surgery is not a routine procedure, but several teams are working on this and experiencing good results. However, economic concerns are the major drawbacks of these systems; before remote surgery becomes routinely feasible, the clinical benefits must be balanced with high investment and running costs.

Humans↗
PubMed2003

Biosensor profiling of molecular interactions in pharmacology.

Techniques employed to profile the pharmacological properties of a molecule in vitro normally require some type of radio-, enzymatic- or fluorescent-labeling of the ligand and/or the receptor. In contrast, biosensor techniques do not require labeling, and they allow virtually any complex to be screened with minimal assay development. Scientists in both academia and industry are now using biosensors in areas that encompass almost all sectors of drug discovery, diagnostics and the life sciences. Assays have been developed for the analysis of small molecules, proteins, oligonucleotides, bacteriophage, viruses, bacteria and cells. In addition, novel biosensor applications are being developed for the predictive profiling of key pharmacokinetic parameters of a molecule (adsorption, distribution, metabolism, excretion and toxicity).

Animals↗
PubMed2006

Alcohol use before and during pregnancy: a population-based study.

BACKGROUND: Few population-based studies have estimated alcohol consumption and binge drinking before and during pregnancy. METHODS: The study is a longitudinal questionnaire study. In Norway, virtually 100% attend an ultrasound screening at 17-18 weeks of pregnancy. In Oslo, a representative sample attending this between June 2000 and May 2001 were invited to join the study, accepted by 92%. Non-Norwegian-speaking and/or immigrants from non-Western countries were not invited; 1,749 (93%) completed the first questionnaire. MEASURES: T-ACE (screening for pregnancy risk drinking), frequency of alcohol use, Standard Units (SU) per occasion, SU/week, and binge drinking (>or=5 SU per occasion). Binary logistic regression analyses, Student's t-test and Pearson's chi square were used. RESULTS: Alcohol use was reported by 89% pre-pregnancy and by 23% after pregnancy week 12. Binge drinking was reported by 59% pre-pregnancy and by 25% during weeks 0-6. Change of drinking pattern occurred at pregnancy recognition for 85%, although 78% had planned the pregnancy, fetal welfare being the main reason. Participants reporting alcohol use during pregnancy were older, smokers, with more SU/week pre-pregnancy, had some elevated anxiety score, higher income, and a partner with higher education. However, mental health, high income, or education were not predictive of usually drinking 1 SU per occasion or more, and not of binge drinking. The latter was predicted mainly by smoking during pregnancy and being T-ACE positive. CONCLUSIONS: The study shows a drinking pattern before pregnancy recognition that, according to other studies, in 25% or more may cause suboptimal fetal development.

Adolescent↗
PubMed2005

Integrating a bovine rectal palpation simulator into an undergraduate veterinary curriculum.

There are problems associated with teaching bovine rectal palpation to undergraduate veterinary students. The students need opportunities to examine enough cows to develop the required skills, but increasing student numbers and limitations on access to cows have made this more and more difficult to achieve. A virtual reality-based teaching tool, the Bovine Rectal Palpation Simulator, has been developed as a supplement to existing training methods. The student palpates computer generated virtual models of the bovine reproductive tract while interacting with a haptic (touch feedback) device. During training sessions, the instructor follows the student's actions inside the virtual cow on the computer screen and gives instruction. A trial integration of the simulator into the fourth-year bovine reproduction course was undertaken at the University of Glasgow Veterinary School during the 2003/2004 academic year. Students were offered two training sessions, and feedback was gathered using questionnaires. In the first session, all students were taught a range of basic skills using a standardized teaching protocol. The second training session was customized to each student's learning needs and included practice in dealing with a range of on-farm scenarios. Student feedback indicated that the training had been useful for learning various aspects of bovine rectal palpation and provided information that helped in the further development of the simulator as a teaching tool.

Animals↗
PubMed2003

Colorectal cancer screening: scientific review.

CONTEXT: Screening for colorectal cancer clearly reduces colorectal cancer mortality, yet many eligible adults remain unscreened. Several screening tests are available, and various professional organizations have differing recommendations on which screening test to use. Clinicians are challenged to ensure that eligible patients undergo colorectal cancer screening and to guide patients in choosing what tests to receive. OBJECTIVE: To critically assess the evidence for use of the available colorectal cancer screening tests, including fecal occult blood tests, sigmoidoscopy, colonoscopy, double-contrast barium enema, and newer tests, such as virtual colonoscopy and stool-based molecular screening. DATA SOURCES: All relevant English-language articles were identified using PubMed (January 1966-August 2002), published meta-analyses, reference lists of key articles, and expert consultation. DATA EXTRACTION: Studies that evaluated colorectal cancer screening in healthy individuals and assessed clinical outcomes were included. Evidence from randomized controlled trials was considered to be of highest quality, followed by observational evidence. Diagnostic accuracy studies were evaluated when randomized controlled trials and observational studies were not available or did not provide adequate evidence. Studies were excluded if they did not evaluate colorectal screening tests and if they did not evaluate average-risk individuals. DATA SYNTHESIS: Randomized controlled trials have shown that fecal occult blood testing can reduce colorectal cancer incidence and mortality. Case-control studies have shown that sigmoidoscopy is associated with a reduction in mortality, and observational studies suggest colonoscopy is effective as well. Combining fecal occult blood testing and sigmoidoscopy may decrease mortality and can increase diagnostic yield. CONCLUSION: The recommendation that all men and women aged 50 years or older undergo screening for colorectal cancer is supported by a large body of direct and indirect evidence. At present, the available evidence does not currently support choosing one test over another.

Aged↗
PubMed2002

Tongan-American women's breast cancer knowledge, attitudes, and screening behaviors.

OBJECTIVE: Breast cancer is the most common cancer for many Pacific Islander American populations, but virtually nothing is known about the cancer risks and screening behaviors of many specific ethnic subgroups. This paper examines the breast cancer risk, knowledge, attitudes, and screening behaviors of Tongan-American women. DESIGN: Research activities were conducted in 3 phases: determination of cancer proportional ratios using data from the California Cancer Registry, exploratory focus groups conducted with 22 women, and self-administered surveys from 303 women (for a response rate of 92%). SETTING AND PARTICIPANTS: Survey respondents were Tongan-American women aged 40 years and older, residing in Los Angeles and Orange Counties. RESULTS: The breast is the most common cancer site for Tongan women, followed by the cervix and uterus, lung and bronchus, and stomach. The proportion of all cancers accounted for by breast cancer is lower among Tongan women (0.8) compared to White women. We found low rates for all types of breast cancer screening: only 40% of respondents had ever performed a breast self-examination (BSE); 26% ever received a clinical breast exam (CBE); and 25% ever received a mammogram. Many misperceptions existed about breast cancer causes, signs, and symptoms as well as the role of screening in detecting pre-symptomatic cancers. CONCLUSIONS: Much emphasis needs to be placed on improving early breast cancer screenings among Tongan-American women, including comprehensive community education, culturally tailored and linguistically appropriate materials, and improved access to low-cost screening sites.

Adult↗
PubMed2002

Recent developments in colorectal cancer screening and prevention.

Colorectal cancer is a significant contributor to morbidity and mortality in the United States. Studies published in the early 1990s, showing that screening for colorectal cancer can reduce colorectal cancer-related mortality, led many organizations to recommend screening in asymptomatic, average-risk adults older than 50 years. Since then, however, national screening rates remain low. Several important studies published over the past four years have refined our understanding of existing screening tools and explored novel means of screening and prevention. The most important new developments, which are reviewed in this article, include the following: Additional trial results support the effectiveness of fecal occult blood testing in reducing the incidence of, and mortality from, colorectal cancer. New studies document the sensitivity of fecal occult blood testing, sigmoidoscopy, and double-contrast barium enema compared with colonoscopy. Cost-effectiveness models show that screening by any of several methods is cost-effective compared to no screening. Randomized trials show that calcium is effective but fiber is not effective in preventing reoccurrence of adenomatous polyps. Preliminary data suggest that nonsteroidal anti-inflammatory drugs may prevent adenomatous polyps and that DNA stool tests and virtual colonoscopy may show promise as screening tools. This new information provides further support for efforts to increase the use of colorectal cancer screening and prevention services in adults older than 50 years.

Adenoma↗
PubMed2004

[The screening of sporadic colorectal cancer].

World Health Organization (WHO) defined the criteria for screening (i.e. the location of asymptomatic individuals) of the diseases seriously endangering the public health condition. The decisive criterion is the decrease of mortality with the disease the screening is made of. The programme based on the testing the asymptomatic individuals for the presence of the fecal occult bleeding (FOBT), which was introduced also in Czech republic, meets the criterion at the screening of colorectal cancer (CR-CA), which has been proved since the year 1993 by the two case-control studies and further particularly by the three prospective, randomized, controlled studies which independently proved the decrease of mortality for CR-CA in the screened population by 15-33%. This programme has been introduced in Federal Republic of Germany since 1977 as a part of free anticancer examination. In 1995 the programme was recommended by the commission of the independent specialists of US Department of Health and in 1998 by the commission of experts of the European Group for Colorectal Cancer Screening. In 2001 the commission of independent specialists of the US Department of Health analysed the contemporary preventive programmes in USA according to the importance of the disease monitored for the condition of public health and the effectiveness of the preventive programme. Based on these criteria there were defined 8 priority preventive programmes and as for the organ malignities there was only CR-CA screening filed there. All the screening programmes are based on the colonoscopic examinations in various time intervals, depending on familiar anamnesis, polyps size and their histologic structure. An alternative to the colonoscopy is a combination of flexible sigmoideoscopy and irigography, but this technique did not establish itself in a larger scale. On the contrary the developed countries offer--in the frame of the large studies as well as standardly--the screening colonoscopy as an alternative to the occult bleeding examination. The predictive ability of the less invasive imaging methods e.g. virtual CT colography is also assayed. The screening programme in the frame of Czech republic has been standardized and as a reccommendation available to the professional community since 2000.

Colonoscopy↗
PubMed2002

[Virtual endoscopy of the urinary tract].

This review article depicts the technique of virtual uro-endoscopy and its diagnostic value and highlights future aspects. The raw data are acquired using CT, MR, or ultrasound. Sufficient contrast between the wall of the hollow organ and its interior is reached by administering gas or contrast medium into the bladder or injecting contrast media i.v. After processing of these data, virtual endoscopic procedures can be watched on a screen in the same way as a cine-film of a conventional endoscopic operation. Virtual endoscopy is a reliable method with a high sensitivity for pathologies larger than 0.5 cm. It is not invasive, and there are situations that cause difficulties in conventional endoscopy (e.g. gross hematuria, diverticula, strictures) that cause no technical problems in virtual endoscopy. Problems encountered in virtual endoscopy are due to its poor sensitivity for pathologies smaller than 0.5 cm, for carcinoma in situ, and for ureteral calculi. So far there are no routine-indications for virtual endoscopy in urology. Nevertheless, it can be of additional value in diagnosis providing the indications are carefully controlled. In future, virtual endoscopy will probably become integrated into the spectrum of urologic diagnostics investigations.

Contrast Media↗
PubMed2005

Screening of colorectal cancer: progress and problems.

Considerable progress has been made in the past three decades in our understanding of the biology and prevention of colorectal cancer. The long natural history of colorectal cancer as it evolves from adenomatous polyps in the majority of cases provides opportunities for detection of early stage cancer and for prevention of cancer by removal of adenomas. Strong evidence of the effectiveness of screening has resulted in a worldwide consensus, as reported in evidence-based guidelines, that screening should be offered to all men and women age 50 and older, younger in the presence of factors that increase risk. Several options are now available for screening, and the emerging technology of stool DNA testing and virtual colonoscopy shows promise. However, many problems remain to be addressed. Screening rates are low. Successful strategies need to be implemented to overcome patient and system barriers. Resources, especially endoscopic capacity, may be inadequate to handle the burden of screening, diagnosis, and follow-up surveillances. There are quality-control issues at every step. Stratification of people by risk, a two-stage screening approach and less intensive surveillance following polypectomy can be helpful. Colorectal cancer screening is cost-effective and could save many lives each year if it were widely implemented.

Biomarkers, Tumor↗
PubMed2001

The stressor criterion in DSM-IV posttraumatic stress disorder: an empirical investigation.

BACKGROUND: The DSM-IV two-part definition of posttraumatic stress disorder (PTSD) widened the variety of stressors (A1) and added a subjective component (A2). The effects of the revised stressor criterion on estimates of exposure and PTSD in a community sample are evaluated. METHODS: A representative sample of 2181 persons in southeast Michigan were interviewed about lifetime history of traumatic events and PTSD. The evaluation of the revised two-part definition is based on a randomly selected sample of events that represents the total pool of traumatic events experienced in the community. RESULTS: The enlarged definition of stressors in A1 increased the total number of events that can be used to diagnose PTSD by 59%. The majority of A1 events (76.6%) involved the emotional response in A2. Females were more likely than males to endorse A2 (adjusted odds ratio = 2.66; 95% confidence interval 1.92, 3.71). Of all PTSD cases resulting from the representative sample of events, 38% were attributable to the expansion of qualifying events in A1. The identification of exposures that lead to PTSD were not improved materially by A2 however, events that did not involve A2 rarely resulted in PTSD. CONCLUSIONS: Compared to previous definitions, the wider variety of stressors in A1 markedly increased the number of events experienced in the community that can be used to diagnose PTSD. Furthermore, A2 might be useful as a separate criterion, an acute response necessary for the emergence of PTSD, and might serve as an early screen for identifying a subset of recently exposed persons at virtually no risk for PTSD. The utility of A2 as a screen must be tested prospectively.

Adolescent↗
PubMed2006

Virtual colonoscopy--an overview.

Virtual colonoscopy is emerging as a technique for the detection of tumor lesions in the colon. Being a patient-friendly examination, virtual colonoscopy could play an important role in colorectal cancer screening. This article reviews the current state of the art of virtual colonoscopy with future developments and issues to be resolved.

Colonic Neoplasms↗
PubMed1999

The regulation of externally paced human locomotion in virtual reality.

The goal of the present experiment was to study regulation of human locomotion under externally paced temporal constraints. On a screen placed in front of a treadmill a virtual hallway was projected (Silicon Graphics systems) in which a pair of doors were presented that continuously opened and closed at a rate of 1 Hz. Subjects were attached to a locometer and instructed to regulate walking pace such that the doors were passed correctly. Performance outcome, movement kinematics (stride duration, stride length and synchronization of stride and door cycles) and flow patterns (change in visual angle of door aperture) were used to examine the data. The analysis of the synchronization patterns indicates that stride cycles were not linked to the period of door oscillation. Moreover, results for stride duration reveal that subjects walked at their preferred speed up to the final phase of the approach. This observation is supported by the inspection of the flow patterns, revealing a final increase in variability as a result of regulation. In sum, regulation of locomotion under externally paced temporal constraints seems to generate a specific functional behavior. It appears that regulations are postponed until the final stage of the approach during which adaptations are made according to the requirements of the current situation.

Biomechanical Phenomena↗
PubMed1987

Frequency and adequacy of breast cancer screening among elderly Hispanic women.

Studies have demonstrated that Hispanic (relative to Anglo) women are at greater risk for late-stage breast cancer diagnosis. Screening irregularity may be a factor contributing to late-stage diagnosis, yet virtually nothing is known about the breast cancer-screening behavior of Hispanic women. We interviewed 600 elderly Hispanic women residing in Los Angeles to collect information on frequency of physician breast examinations and mammography and on regularity and competence of breast self-examination. Predictors of screening were also examined. Fifty percent of our sample indicated that they had had a breast exam within the past year; 12.5% had had a mammogram within the past year (74% never had had a mammogram); and 47% reported that they had performed breast self-examination within the past month. Few of the women were able to demonstrate adequate breast self-examination technique on a foam breast model, and only 1% found all five lumps present. Thus, although the observed frequency of screening and self-examination is comparable to national norms, it is unlikely that our subjects' attempts at self-examination would lead to early breast cancer detection. Age, educational level, emotional reactions to screening, and media cues predicted screening behavior. Physician instruction in breast self-examination increased the frequency and adequacy of self-examination. Perceived susceptibility to cancer, perceived benefits of early detection, and level of acculturation were not strong predictors. The extent to which our results generalize to other subpopulations of Hispanic women is discussed.

Aged↗
PubMed2005

Projected national impact of colorectal cancer screening on clinical and economic outcomes and health services demand.

BACKGROUND & AIMS: Colorectal cancer (CRC) screening is effective and cost-effective, but the potential national impact of widespread screening is uncertain. It is controversial whether screening colonoscopy can be offered widely and how emerging tests may impact health services demand. Our aim was to produce integrated, comprehensive estimates of the impact of widespread screening on national clinical and economic outcomes and health services demand. METHODS: We used a Markov model and census data to estimate the national consequences of screening 75% of the US population with conventional and emerging strategies. RESULTS: Screening decreased CRC incidence by 17%-54% to as few as 66,000 cases per year and CRC mortality by 28%-60% to as few as 23,000 deaths per year. With no screening, total annual national CRC-related expenditures were 8.4 US billion dollars. With screening, expenditures for CRC care decreased by 1.5-4.4 US billion dollars but total expenditures increased to 9.2-15.4 US billion dollars. Screening colonoscopy every 10 years required 8.1 million colonoscopies per year including surveillance, with other strategies requiring 17%-58% as many colonoscopies. With improved screening uptake, total colonoscopy demand increased in general, even assuming substantial use of virtual colonoscopy. CONCLUSIONS: Despite savings in CRC care, widespread screening is unlikely to be cost saving and may increase national expenditures by 0.8-2.8 US billion dollars per year with conventional tests. The current national endoscopic capacity, as recently estimated, may be adequate to support widespread use of screening colonoscopy in the steady state. The impact of emerging tests on colonoscopy demand will depend on the extent to which they replace screening colonoscopy or increase screening uptake in the population.

Colorectal Neoplasms↗