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At least 1,243 records · Page 69Linked to original sources
PubMed1997

An overview of the breast cancer screening controversy.

Randomized controlled studies show that screening mammograms are as important for women aged 40-49 as for women 50 years old and above. It was the improper use of retrospective, unplanned, sub-group analysis to advise women and their physicians that caused the controversy over mammograms for women under 50. Furthermore, arbitrarily grouping women into two groups leads to the incorrect conclusion that the age of 50 is a significant break point when it is not. The data demonstrates that none of the parameters of screening change abruptly at age 50. The recall rates (an abnormal mammogram) and the rate at which biopsies are recommended are virtually the same, regardless of age. Breast cancer is not a trivial problem for women in their forties. More than 30% of the years of life lost to breast cancer are from women diagnosed while in their forties. Because of changing demographics, in 1995 and 1996, there were actually more women diagnosed with breast cancer in their forties than for women in their fifties. The data clearly show that screening women for breast cancer, on an annual basis, beginning by age 40, can reduce the death rate by approximately 24%. It is important to separate medical and scientific analyses from the economic considerations. "Society" may decide that it is too expensive to screen women for breast cancer, but women should be provided with the scientific and medical information so that they can participate in the discussion of whether screening is "worthwhile" and decide whether or not to avail themselves of its benefit. The economics should not be used to influence the scientific and medical analysis of benefit.

Adult↗
PubMed1990

Prevalence of anisometropia in volunteer laboratory and school screening populations.

For 10 years our laboratory has conducted, a longitudinal study of focusing and motor behavior of a volunteer population of 686 subjects aged 3 months to 9 years. Its purpose is to characterize normal refractive development in infants and children and to relate refractive anomalies to subsequent visual problems. Using age-related criteria for anisometropia adjusted to detect the most unusual 5% of the refractions on a test battery, we have found 19 nonstrabismic, anisometropic subjects (2.8% of total subject population). Of these, eight were either seen once or their anisometropia appeared at their last visit. Of the remaining 11 subjects, all had a reduction of their anisometropia to within normal limits on subsequent visits. Thus our current best estimate of persistent infant anisometropia is 0%, a startling result. By comparison, we found ten strabismic subjects (1.46%), two of whom had persistent anisometropia. Although we did not believe that anisometropic subjects could self-select and not participate in the study, it was possible that the volunteer laboratory population had characteristics atypical of the county at large. Thus we conducted a screening of 374 Head Start and first-grade pupils throughout the county, using the same methods. We found virtually no difference in the average refractive conditions between the laboratory and school populations and no significant difference in the prevalence of visual disorders. The very low prevalence of anisometropia in infants and young children in both populations has important implications for the etiology of anisometropic amblyopia.

Anisometropia↗
PubMedDate not supplied

Current and evolving strategies for colorectal cancer screening.

BACKGROUND: Colorectal cancer is a major cause of cancer mortality and morbidity. Screening can potentially prevent most colorectal cancers by detection and removal of precursor adenomas. METHODS: The literature and clinical practice guidelines are reviewed, with an emphasis on advances of the last 10 years and evolving screening methods. RESULTS: Colonoscopy has come to be used for screening in persons at average risk for colorectal cancer because of the comparative ineffectiveness of other methods, although these methods continue to be recommended. Virtual colonoscopy and fecal DNA testing are emerging technologies with promise to be more effective than fecal occult blood testing or sigmoidoscopy in selecting those persons who should undergo colonoscopy. Next to age, family history is the most common risk factor for colorectal cancer and one that warrants more aggressive screening and, in some instances, genetic counseling and testing. Hereditary nonpolyposis colorectal cancer accounts for as many as 1 in 20 colorectal cancers, but to take advantage of recent advances in genetic testing for this disorder, a high level of clinical suspicion must be maintained. CONCLUSIONS: If we are to reduce mortality and morbidity from colorectal cancer, practicing clinicians need to be aware of current and evolving strategies for colorectal screening, and assertively recommend the appropriate strategy to their patients.

Colonography, Computed Tomographic↗
PubMed2002

Functional cloning, sorting, and expression profiling of nucleic acid-binding proteins.

A major challenge in the post-sequencing era is to elucidate the activity and biological function of genes that reside in the human genome. An important subset includes genes that encode proteins that regulate gene expression or maintain the structural integrity of the genome. Using a novel oligonucleotide-binding substrate as bait, we show the feasibility of a modified functional expression-cloning strategy to identify human cDNAs that encode a spectrum of nucleic acid-binding proteins (NBPs). Approximately 170 cDNAs were identified from screening phage libraries derived from a human colorectal adenocarcinoma cell line and from noncancerous fetal lung tissue. Sequence analysis confirmed that virtually every clone contained a known DNA- or RNA-binding motif. We also report on a complementary sorting strategy that, in the absence of subcloning and protein purification, can distinguish different classes of NBPs according to their particular binding properties. To extend our functional annotation of NBPs, we have used GeneChip expression profiling of 14 different breast-derived cell lines to examine the relative transcriptional activity of genes identified in our screen and cluster analysis to discover other genes that have similar expression patterns. Finally, we present strategies to analyze the upstream regulatory region of each gene within a cluster group and select unique combinations of transcription factor binding sites that may be responsible for dictating the observed synexpression.

Adenocarcinoma↗
PubMed1997

Transcription of the gene encoding melanoma-associated antigen gp100 in tissues and cell lines other than those of the melanocytic lineage.

The expression of the gp100 antigen is generally thought to be confined to cells of the melanocytic lineage, which makes the protein a suitable melanoma-specific marker. Strikingly, after screening a panel of normal tissues, tumour samples and cell lines of non-melanocytic origin, we found transcripts encoding gp100 in virtually every tissue and cell line tested. In contrast, tyrosinase and MART-1/MelanA transcripts were detected only in cells of the melanocytic lineage. However, no gp100 protein could be detected by either Western blotting or cytotoxicity assays. Therefore, at the protein level, gp100 remains exclusive for cells of melanocytic origin despite its transcription in many cell types. The major implication of this finding is that screening of patient material for gp100 expression should preferrably be performed by antibody staining. Reverse transcriptase polymerase chain reaction (RT-PCR) can be employed, provided that it is performed in a tightly controlled, semiquantitative setting.

Antigens, Neoplasm↗
PubMed1994

Sudden death screening.

SCD is a tragic-event that rarely affects exercising individuals. It is important for the practitioner to recognize the normal physiologic changes that occur in the exercising athlete that correspond to AHS so as to differentiate them from conditions placing an athlete at risk for SCD. Different clinical entities account for SCD in athletes under age 30 as opposed to over age 30, although there is some overlap. Comprehensive and expensive screening tests have not proved to be cost-effective, nor are they able consistently to identify athletes at risk. A quality history and thorough cardiac screening examination are the best means to identify athletes at risk for SCD and lead to a cost-effective means to pursue further workup. Table 7 lists a screening battery of tests and what the tests detect and miss. In general, a history and physical examination detect aortic stenosis and a portion of HCM and Marfan's syndrome. If the physical examination is suggestive of Marfan's syndrome and a chest roentgenogram is done, a larger portion of cystic medial necrosis will be found. When an ECG is added to the series, most of the HCM patients at risk for SCD can be diagnosed. In addition, if echocardiography is added, most patients with HCM and cystic medial necrosis can be identified. If an exercise stress test is then performed, 20% of coronary artery disease and congenital artery anomalies are identified. Additional studies, including Holter monitoring, electrophysiologic studies, and thallium scintigraphy, can be added to identify further at-risk patients. Because some asymptomatic patients present with SCD, it is virtually impossible to identify comprehensively all patients at risk. By knowing what questions to ask, performing a thorough cardiac screening examination, and being more aware of potential diagnostic clues, the practitioner can feel comfortable in identifying most patients at risk for SCD. Specific history and physical examination guidelines regarding screening for competition are included. Supplemental information is found in the 16th Bethesda Conference. In addition, a well-outlined emergency plan needs to be established when physicians, athletic trainers, or coaches are working with athletes. Proper recognition of cardiac symptoms is a key point. Appropriate education including basic first aid and cardiopulmonary resuscitation training should be encouraged for anyone working extensively with athletes. The emergency plan should include on-site treatment, mechanism to contact emergency personnel, and proper transport to a qualified facility.

Adult↗
PubMed2006

Stably transformed insect cell lines: tools for expression of secreted and membrane-anchored proteins and high-throughput screening platforms for drug and insecticide discovery.

Insect cell-based expression systems are prominent amongst current expression platforms for their ability to express virtually all types of heterologous recombinant proteins. Stably transformed insect cell lines represent an attractive alternative to the baculovirus expression system, particularly for the production of secreted and membrane-anchored proteins. For this reason, transformed insect cell systems are receiving increased attention from the research community and the biotechnology industry. In this article, we review recent developments in the field of insect cell-based expression from two main perspectives, the production of secreted and membrane-anchored proteins and the establishment of novel methodological tools for the identification of bioactive compounds that can be used as research reagents and leads for new pharmaceuticals and insecticides.

Animals↗
PubMedDate not supplied

The relationship between sociodemographic characteristics and recruitment, retention, and health improvements in a worksite health promotion program.

BACKGROUND: Recruitment, retention, and success in a worksite health promotion program was examined among various demographic groups of employees (n = 11,830) of the Dallas, Texas Independent School District. METHODS: Enrolled employees (n = 3,873) were given a health screen consisting of health habit assessment, measurement of clinical variables, physical fitness testing, and a medical examination. RESULTS: Thirty-three percent of employees were successfully recruited into the program. Recruitment rates were virtually identical for men and women (32% and 33%, respectively), but varied across ethnic, age, and education groups. Blacks, younger employees, and noncollege graduates were less likely to be recruited. Sixty-nine percent of the employees were retained in the program, as defined by participation in the second screen, and women were more likely to be retained than men (71% versus 64%, respectively). Retention rates throughout the 10-week program were higher for whites and Hispanics, and were virtually identical for each age group and education level. Overall, participants in the program showed an improvement in physical fitness and general well-being, lost weight, and smoked less. These changes were relatively consistent across the various demographic groups. DISCUSSION: Data suggest demographic characteristics are related to recruitment and retention in a health promotion program.

Adult↗
PubMed2003

Eye movement, vection, and motion sickness with foveal and peripheral vision.

BACKGROUND: Both motion sickness and the illusion of self-motion (i.e., vection) can be induced by moving visual scenes. The results of a previous study imply that motion sickness is primarily dependent on visual motion in foveal vision while vection is primarily dependent on motion in peripheral vision. HYPOTHESIS: It was hypothesized that similar motion sickness would be produced when tracking a single moving dot and a full screen of moving dots, but that vection would be greater when tracking multiple moving dots. METHOD: Sixteen subjects viewed moving images presented on a virtual reality head-mounted display. In one condition a single dot moved from left to right at 27 degrees x s(-1) over a distance of 18 degrees before returning instantly to its starting point. This motion was repeated continuously. In a second condition, five horizontal rows of dots, each 18 degrees apart, moved continuously across the screen at 27 degrees x s(-1); subjects were instructed to track each dot in the central row as it passed. RESULTS: In both conditions, there were nystagmic eye movements with an approximate amplitude of 18 degrees at 27 degrees x s(-1). Vection differed significantly between the two conditions, with more vection in the condition with five rows of dots. Subjects experienced motion sickness symptoms with both the single moving dot and the five rows of dots, with no significant difference in sickness between the two conditions. Subject ratings of motion sickness and vection were not correlated with each other in either of the two conditions. CONCLUSIONS: Motion sickness and vection can vary independently. Vection appears to be influenced by peripheral vision, as there was an increase in vection with full-field stimulation. Motion sickness induced by moving visual scenes may be influenced by foveal visual stimulation or by eye movements, as these were the same in both conditions.

Eye Movements↗
PubMed1997

Molecular cloning of human GATA-6 DNA binding protein: high levels of expression in heart and gut.

Human GATA-6 has been cloned from foetal heart by a combination of PCR-based methods and cDNA library screening. The 3.8 kbp cDNA has a coding sequence of 1347 bp the 449 aa protein is virtually identical in the two zinc-finger binding domains to other human GATA sequences, but varies considerably in the amino and carboxy terminal regions. The sequence shows greatest similarity to GATA-6-like sequences from rat, mouse, chicken and Xenopus. Northern analysis and in situ hybridisation show that GATA-6 is expressed at high levels in human adult and foetal heart as well as in gut derivatives. It is postulated that GATA-6, in concert with GATA-4, plays a crucial role in the regulation of cardiac differentiation.

Amino Acid Sequence↗
PubMed1998

Factors predictive of survival among 337 patients with mesothelioma treated between 1984 and 1994 by the Cancer and Leukemia Group B.

PURPOSE: To examine the individual and joint effect of various pretreatment clinical characteristics on the survival of patients with mesothelioma treated by the Cancer and Leukemia Group B (CALGB). PATIENTS AND METHODS: Between June 1984 and September 1994, 337 patients with malignant mesothelioma and no prior chemotherapy were accrued to seven phase II studies conducted by the CALGB which screened the efficacy of 10 treatment regimens or dose levels. The eligibility criteria for all studies were virtually identical. Patient characteristics include the following: age older than 60 years (63%); male (83%); performance status (PS) of 0 or 1 (81%); chest pain (60%); definite asbestos exposure (62%); >5% weight loss (41%); and pleural involvement (94%). Median survival time (MST) for the 10 treatment regimens ranged from 3.9 to 9.8 months (overall=7.2; 95% confidence interval [CI], 6.5 to 8.3), with 1-year survival between 14% and 50% (overall=27%; 95% CI, 23 to 33%). RESULTS: Cox survival models and exponential regression trees were used to examine the prognostic importance of pretreatment patient characteristics. Univariate analyses show that patients with poor Eastern Cooperative Oncology Group PS, chest pain, dyspnea, platelet count (PLT) >400,000/microL, weight loss, serum lactate dehydrogenase (LDH) level >500 IU/L, pleural involvement, low hemoglobin (HGB) level, high WBC count, and increasing age over 75 years have a worse prognosis. With decreasing risk ratio, multivariate Cox analyses showed that pleural involvement, LDH >500 IU/L, poor PS, chest pain, PLT >400,000/microL, nonepithelial histology, and increasing age older than 75 years jointly predict poor survival. PS was the most important prognostic split in the regression tree. Terminal nodes were amalgamated to form six distinct prognostic subgroups with MST (2-year survival) of 13.9 (38%) in 36 patients, 9.5 (21%) in 36 patients, 9.2 (10%) in 146 patients, 6.5 (3%) in 33 patients, 4.4 (0%) in 73 patients, and 1.4 (0%) in 13 patients (p<0.0001). CONCLUSIONS: The subgroup with the best survival (MST=13.9 months) included patients with PS=0 and age younger than 49 years, and patients with PS=0, age of 49 years or older, and HGB > or =14.6. The worst survival (MST= 1.4 months) occurred for patients with PS= 1/2 and WBC > or =15.6/microL.

Aged↗
PubMed1981

A comparative physical evaluation of four X-ray films.

In this study, four general purpose radiographic films (Agfa Gevaert Curix RP-1, duPont Cronex 4, Fuji RX, and Kodak XRP-1) were compared using three independent techniques. By examining the characteristic curves for the four films, film speed and contrast were compared over the diagnostically useful density range. These curves were generated using three methods: (1) irradiation of a standard film cassette lined with high-speed screens, covered by a twelve-step aluminum wedge; (2) direct exposure of film strips to an electro-luminescent sensitometer; and (3) direct irradiation of a standard film cassette lined with high-speed screens. The latter technique provided quantitative values for film speed and relative contrast. All three techniques provided virtually properly identical results and indicate that under properly controlled conditions simplified methods of film testing can give results equivalent to those obtained by more sophisticated techniques.

Evaluation Studies as Topic↗
PubMedDate not supplied

Transfusion-transmitted infections: existing and emerging pathogens.

In general, the risk of transfusion-transmitted infections has been greatly reduced today. However, blood-borne bacterial and parasitic infections and emerging infections transmitted through transfusion are an area of increasing concern. Implementation of stringent donor eligibility criteria, improved donor screening and more sophisticated as well as sensitive methods of antibody, antigen and viral genome detection, have virtually eliminated transfusion transmitted infection in developed countries. In developing countries like India, the risk of transfusion-transmitted infections is still considerable. A comprehensive MEDLINE search and review of relevant transfusion medicine literature were carried out and the data extracted and studied with particular reference to emerging pathogens transmitted through blood transfusion and posing a huge threat.

Animals↗
PubMed1978

Parathyroid hormone and hyperparathyroidism: current concepts.

Our expanding knowledge of the physiologic and biochemical factors governing calcium homeostasis has improved our capacity to evaluate hypercalcemia, of which an increased incidence is being discovered through the widespread use of multiphasic screening. Consequently, we are diagnosing mild forms of hyperparathryoidism more often than formerly. The enhanced recognition of virtually symptom-free hyperparathyroidism presents a problem in patient management because the natural history of this form of hyperparathyroidism is unknown and the pathologic lesion underlying the condition may be ambiguous, resulting in difficult decisions in surgical management. Further study is required to resolve this issue in order to provide optimal care for the affected individual.

Animals↗
PubMedDate not supplied

Behavioral teratogenicity testing as a method of screening for hazards to human health: a methodological proposal.

Behavioral teratology (psychoteratology) is the study of abnormal behavioral development, with particular attention to damage to the embryo or fetus. Behavioral teratology testing is being applied as a method to screen new agents for this form of toxicity in laboratory animals in several countries, yet there is virtually no discussion available in the literature that delineates the major factors that must be considered in conducting such tests, nor are there published recommendations for handling them. This paper states these issues and then presents a position on how each might be handled based on data from the behavioral teratology literature.

Animals↗
PubMed2005

Building a virtual cancer research organization.

BACKGROUND: The Cancer Research Network (CRN) comprises the National Cancer Institute and 11 nonprofit research centers affiliated with integrated health care delivery systems. The CRN, a public/private partnership, fosters multisite collaborative research on cancer prevention, screening, treatment, survival, and palliation in diverse populations. METHODS: The CRN's success hinges on producing innovative cancer research that likely would not have been developed by scientists working individually, and then translating those findings into clinical practice within multiple population laboratories. The CRN is a collaborative virtual research organization characterized by user-defined sharing among scientists and health care providers of data files as well as direct access to researchers, computers, software, data, research participants, and other resources. The CRN's research management Web site fosters a high-functioning virtual scientific community by publishing standardized data definitions, file specifications, and computer programs to support merging and analyzing data from multiple health care systems. RESULTS: Seven major types of standardized data files developed to date include demographics, health plan eligibility, tumor registry, inpatient and ambulatory utilization, medication dispensing, laboratory tests, and imaging procedures; more will follow. Data standardization avoids rework, increases multisite data integrity, increases data security, generates shorter times from initial proposal concept to submission, and stimulates more frequent collaborations among scientists across multiple institutions. CONCLUSIONS: The CRN research management Web site and associated standardized data files and procedures represent a quasi-public resource, and the CRN stands ready to collaborate with researchers from outside institutions in developing and conducting innovative public domain research.

Biomedical Research↗
PubMed2004

Glycogen storage disease type II: enzymatic screening in dried blood spots on filter paper.

BACKGROUND: Glycogen storage disease II is characterized by a deficiency of the lysosomal enzyme acid alpha-glucosidase. Currently, glycogen storage disease II is diagnosed by demonstrating the virtual absence or a marked reduction of acid alpha-glucosidase activity in muscle biopsies, cultured fibroblasts, or purified lymphocytes. Early diagnosis and treatment of glycogen storage disease II are considered to be critical for maximum efficacy of the enzyme replacement therapies that are in development. However, these existing diagnostic methods are not suited for newborn screening. We developed an assay useful for newborn screening for glycogen storage disease II. METHODS: A series of three enzyme assays to measure the alpha-glucosidase activities in dried blood spots on filter paper was developed. The measurement of acid alpha-glucosidase activity with minimal interference by other alpha-glucosidases was accomplished using maltose as an inhibitor. The method was used on samples from glycogen storage disease II patients, obligate heterozygotes, and healthy controls. RESULTS: Glycogen storage disease II patients were distinguished from carriers and healthy controls using the series of enzyme assays. CONCLUSIONS: We developed a simple and noninvasive screening method for glycogen storage disease II. The method could be incorporated into newborn screening.

Adolescent↗