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J Young

Publications and source records attributed to J Young.

At least 109 records · Page 6Linked to original sources
PubMed2001

Coronary artery calcium measurement: agreement of multirow detector and electron beam CT.

OBJECTIVE: The purpose of our study was to establish the most suitable algorithm to compare coronary artery calcium measurements performed with electron beam CT and multirow detector CT for the assessment of coronary artery disease. SUBJECTS AND METHODS: Coronary artery screening was performed in 100 patients with both electron beam and multirow detector CT. The images were transferred to a dedicated workstation for determination of the calcium score, volume, mass, density, and number of lesions. In addition to the traditional threshold of 130 H, the score of multirow detector CT studies was reevaluated at a threshold of 90 H. Fifty-nine of the patients underwent conventional coronary catheterization. Receiver operating characteristic curve analysis of the different scoring algorithms for detection of significant coronary artery stenosis was performed. RESULTS: The correlation between electron beam CT and multirow detector CT was high for every quantification algorithm. Determination of the score and the number of lesions with multirow detector CT revealed a systematic error of the measurement compared with electron beam CT. The areas under the curve in the receiver operating characteristic curve analyses for electron beam and multirow detector CT were similar for the score, volume, and mass, whereas they were lower for the density. No significant difference was found for the areas under the curve between scores using a 130-H and those using a 90-H threshold. CONCLUSION: Volume and mass indexes are superior to the traditional score, density, and number of lesions for comparing the results of electron beam and multirow detector CT and for determining significant coronary artery disease.

Adult↗
PubMed2000

Therapeutic adjuncts for immediate transfer to the catheterization laboratory in patients with acute coronary syndromes.

Early coronary intervention in patients with non-ST-segment elevation myocardial infarction (MI) and unstable angina may be made safer and more efficacious with concomitant therapies, including glycoprotein IIb/IIIa inhibitors and low-molecular-weight heparins. Stent placement has been shown to improve procedural success and reduce major in-hospital complications when compared with balloon angioplasty alone in patients with unstable angina. However, unstable angina remains a major hazard for adverse coronary events in long-term follow-up after elective stent placement. The currently available glycoprotein IIb/IIIa inhibitors-eptifibatide, tirofiban, and abciximab--have each been shown to reduce ischemic events before percutaneous coronary intervention when administered to patients presenting with non-ST-segment elevation acute coronary syndromes in large clinical trials. The adjunctive role of low-molecular-weight heparins in this scenario has been largely unexplored. Enoxaparin, when given before angiography or percutaneous coronary intervention, has been shown to be superior to unfractionated heparin in preventing major coronary events. In this review, an algorithm for treatment of non-ST-segment elevation acute coronary syndromes is presented and the current role of these newer adjunctive pharmacotherapies is explored. In the future, combinations of these agents may prove to be most beneficial in patients undergoing early percutaneous coronary intervention.

Abciximab↗
PubMed2000

Non-penetrance in tuberous sclerosis.

As a result of extreme clinical variability in tuberous sclerosis, with one well-documented example of non-penetrance, phenotypically normal siblings or children of patients with tuberous sclerosis are thought to be at increased risk of having children with the disease. We report that the case of apparent non-penetrance that was previously described is the result of two independent tuberous-sclerosis mutations in the same family.

Exons↗
PubMed2000

Allelic loss at SMAD4 in polyps from juvenile polyposis patients and use of fluorescence in situ hybridization to demonstrate clonal origin of the epithelium.

Juvenile polyposis syndrome (JPS; Online Mendelian Inheritance in Man2 174900) is a rare Mendelian disorder in which individuals have typical hamartomatous polyps within the gastrointestinal tract. The stromal element of the polyps has classically been thought to be the proliferative component, although epithelial malignancies (largely gastrointestinal cancers) occur more frequently than expected in JPS patients. Germ-line mutations in SMAD4 (DPC4) account for about a third of JPS cases. It has been postulated that the apparent paradox of a stromal lesion predisposing to epithelial malignancy can be resolved by the "landscaper" effect: an abnormal stromal environment affects the development of adjacent epithelial cells, and the resulting regeneration of damaged epithelium leads to an increased risk of cancer. We have found allele loss at the SMAD4 locus on 18q in polyps from JPS individuals with a germ-line SMAD4 mutation, showing that SMAD4 is acting as a tumor suppressor gene in JPS polyps, as it does in sporadic cancers of the gastrointestinal tract. Interphase fluorescence in situ hybridization showed deletion of one copy of SMAD4 in the epithelial component of JPS polyps, but not in the inflammatory infiltrate. Fluorescence in situ hybridization also suggested that a single copy of SMAD4 was present in stromal fibroblasts of JPS polyps. Thus, biallelic inactivation of SMAD4 occurs in both the epithelium and some of the stromal cells in these lesions, suggesting a common clonal origin. Epithelial malignancies almost certainly develop in juvenile polyposis through direct malignant progression of the epithelial component of the hamartomas. SMAD4/DPC4 probably acts as a "gatekeeper" tumor suppressor in juvenile polyps, and there is no need to invoke a "landscaper hypothesis."

Adenomatous Polyposis Coli↗
PubMed2000

Dietary and/or nutritional risk factors and breast carcinoma: consumer response.

The author is a former state legislator and feminist activist. Having traveled extensively in Asia, she questions the comparison of U.S. statistics regarding dietary/nutritional risk factors with those from countries whose public health standards are below that of the U.S. The author also notes that only recently has the U.S. had a critical mass of women in Congress that led to the funding of the first Women's Health Initiative. Countries in Asia have few women in positions of political power to advocate for public policies regarding women's health issues, especially concerning the gathering of data regarding breast carcinoma, which is considered a culturally sensitive topic. Although soy is considered a healthy staple of the majority of Asian diets because of its phytoestrogens, there is a mixed message to American consumers because cancer, rather than heart disease, is the leading cause of death among Asian females.

Asia↗
PubMed2000

The forensic analysis of soil organic by FTIR.

In order to elucidate the discriminating power of various soil analytical techniques, over 100 soils samples were analyzed using conventional analysis (i.e., color, percent organic and density gradient) and a novel FTIR technique. The FTIR technique involves collecting a spectrum of a soil sample that has been oxidatively pyrolysed, and therefore all organic have been degraded. This spectrum is subtracted from the spectrum of the same sample that contained the organic prior to pyrolysis. This resultant IR spectrum represents the organic portion of the sample. The use of organic components increases the discrimination in soils that are otherwise similar. We have illustrated the usefulness of this technique by selecting four soil samples, which have identical Munsel color values but can be discriminated by subtractive ETIR. We propose that the ETIR spectra of the organic portion of soil serves a useful purpose in forensic investigations.

Forensic Medicine↗
PubMed2000

Sequence variants of DLC1 in colorectal and ovarian tumours.

Loss of heterozygosity occurs frequently on the short arm of chromosome 8 in many neoplasms, including colorectal and ovarian cancer. Monochromosome transfer experiments into colorectal tumour cell lines have provided functional evidence for a tumour suppressor gene located at 8p22-23. One of the genes from this region that is expressed by our suppressed hybrids is a candidate tumour suppressor gene, DLC1 (deleted in liver cancer), which has homology to rat RhoGAP. We have delineated the structure of the DLC1 gene and used single-stranded conformation polymorphism analysis (SSCP) to look for sequence variants in 126 colorectal and 33 ovarian primary tumours and cell lines. One exonic missense mutation and three intronic insertions/deletions were identified in primary colorectal tumours, as well as many polymorphisms present in germline DNAs. The rarity of exonic missense mutations, and the absence of protein-truncating mutations, indicates that DLC1 is not the target of 8p LOH in colorectal or ovarian tumours. The delineation of the gene structure allows mutation analysis of DLC1 in other tumour types for which it remains a candidate tumour suppressor gene based on its location and homology to rhoGAP.

5' Untranslated Regions↗
PubMed2000

Medical day hospital care for the elderly versus alternative forms of care.

BACKGROUND: Geriatric day hospitals provide multi-disciplinary rehabilitation in an outpatient setting. Concern has been expressed that evidence for effectiveness is equivocal and that day hospital care is expensive. OBJECTIVES: To assess the effects of medical day hospitals for elderly people. SEARCH STRATEGY: We searched The Cochrane Library, MEDLINE, Sigle, Bids, and Cinahl up to January 1997, and reference lists of articles. We also searched Index Medicus and International Dissertation Abstracts up to January 1997. We contacted authors of previous studies of day hospital care. SELECTION CRITERIA: Randomised trials comparing geriatric medical day hospitals with alternative forms of care. The participants were elderly medical patients. The outcomes were death, place of residence, dependency, global 'poor' outcome (death, institutionalisation or dependency), activities of daily (ADL) score, subjective health status, patient satisfaction, and resource use. DATA COLLECTION AND ANALYSIS: Three reviewers independently extracted data and assessed study quality. MAIN RESULTS: Twelve studies were included involving 22 day hospitals and 2867 patients. Five studies compared day hospital with comprehensive elderly care, four compared day hospital with domiciliary care and three compared day hospital with no comprehensive elderly care. There were no significant differences between day hospital attendance and comparison treatments for the outcomes of death, death or requiring institutional care, death or deterioration in ADL. When death or a 'poor' outcome at follow up was examined there was a significant difference in favour of day hospital attendance when compared to no comprehensive elderly care (odds ratio 0.73; 95% confidence interval 0.53-1.00; P < 0.05). Dependency was measured in 11 studies using a variety of ADL measures; two described short-term improvement for the day hospital group, one reported improved outcome for the comparison group, while in the remainder there was no statistically significant difference. Using the outcome of deterioration in ADL among survivors, day hospital patients showed reduced odds of deterioration compared with those receiving no comprehensive elderly care (0.60; 0.38-0.97; P <0.05). When resource use was examined the day hospital group showed trends towards reductions in hospital bed use and placement of survivors in institutional care. Nine studies comparing treatment costs indicated that day hospital attendance was a more expensive option, although only two analyses took into account long-term care costs. REVIEWER'S CONCLUSIONS: Medical day hospital care for the elderly appears to be more effective than no intervention but may have no clear advantage over other forms of comprehensive elderly medical services.

Aged↗
PubMed2000

p73 is up-regulated in a subset of hepatocellular carcinomas.

Loss of heterozygosity (LOH) at 1p36 occurs in a number of solid tumors including hepatocellular carcinoma (HCC). Recently, a novel gene, p73, has been identified at 1p36.33. p73 is structurally and functionally related to p53 located at 17p13.1, which is a target for inactivation in HCCs. p73 produces at least two splicing variants, p73alpha and beta, and a polymorphism in exon 2 results in two alleles, GC or AT. Initially, only the AT allele and p73alpha transcripts were identified in malignant cell lines, suggesting a role for these in the malignant phenotype. The aims of this study were to determine the extent of LOH at 1p36 and 17p13.1 in HCCs from Australia and South Africa, and to identify patterns of p73 mRNA and p73 and p53 protein expression. LOH at 1p36 was found in 8 of 25 Australian and 6 of 10 South African cases. p73 mRNA expression occurred in 8 HCCs, but not in nonmalignant liver tissue. Two of these 8 HCCs had LOH of 1p36. Both alpha and beta transcripts were observed in GC/GC homozygotes and GC/AT heterozygotes. No p73 protein expression was observed by immunohistochemistry in nonmalignant liver tissue or in HCC. p53 inactivation appeared to be associated with up-regulation of p73 expression, suggesting a compensatory role for p73 in this situation. The LOH at 1p36 implies a liver-specific tumor suppressor gene is in this region. However, the up-regulation of p73 mRNA suggests p73 is not the target of this loss.

Adult↗
PubMed2000

The filmless radiology reading room: a survey of established picture archiving and communication system sites.

The purpose of this study was to survey radiologists experienced in soft-copy diagnosis using computer workstations about their current reading room environment, their impressions of the efficacy of their reading room design, and their recommendations based on their experience for improvement of the soft-copy reading environment. Surveys were obtained from radiologists at seven sites representing three major picture archiving and communication system (PACS) vendors throughout the world that have had extensive experience with soft-copy interpretation of radiology studies. The radiologists filled out a detailed survey, which was designed to assess their current reading room environment and to provide them with the opportunity to make suggestions about improvement of the PACS reading rooms. The survey data were entered into a database and results were correlated with multiple parameters, including experience with PACS, types of modalities interpreted on the system, and number of years of experience in radiology. The factors judged to be most important in promoting radiologist productivity were room lighting, monitor number, and monitor brightness. Almost all of the radiologists indicated that their lighting source was from overhead rather than indirect or portable light sources. Approximately half indicated they had the capability of dimming the brightness of the overhead lighting. Most radiologists indicated that they were able to adjust room temperature but that they did not have individual temperature controls at their workstations. The radiologists indicated that the most troublesome sources of noise included background noise, other radiologists, and clinicians much more than noise from computer monitors, technologists, or patients. Most radiologists did not have chairs that could recline or arm rests. Most did have wheels and the capability to swivel, both of which were judged important. The majority of chairs also had lumbar support, which was also seen to be important. Radiologists commonly adjusted room lighting and their reading chair, but rarely adjusted room temperature or monitor brightness. The median number of hours spent at the workstation before taken a "break" was 1.5. Common recommendations to improve the room layout included compartmentalization of the reading room and availability of the hospital/radiology information system at each workstation. The survey data suggest several areas of potential improvement based on radiologists' experience. Optimization of soft-copy reading room design is likely to result in decreased fatigue and increased productivity.

Attitude of Health Personnel↗
PubMed2000

ENVIRONMENTAL AUDITING: An Integrated Approach to Reservoir Management: The Williston Reservoir Case Study.

/ The management of industrial reservoirs for hydroelectric energy can cause severe impacts to surrounding communities. This study examines the generation of dust along the northern foreshore zones of Williston Reservoir in northern British Columbia. The dust is generated in the spring when the reservoir levels are low and impacts a relocated First Nations' village (Tsay Keh) at the north end of the reservoir. Data were gathered to provide an overview of the physical conditions that contribute to the dust problem, including a social survey, soil analysis, and vegetation inventory. The study provides a scoping method to assess a large-scale and complex problem with respect to dust management along a large reservoir. Methods for dust control include short- and long-term solutions that integrate the use of native vegetation along the foreshore zones of the reservoir.

Journal Article↗
PubMed2000

Randomized trial of candesartan cilexetil in the treatment of patients with congestive heart failure and a history of intolerance to angiotensin-converting enzyme inhibitors.

BACKGROUND: Many patients with congestive heart failure do not receive the benefits of angiotensin-converting enzyme (ACE) inhibitors because of intolerance. We sought to determine the tolerability of an angiotensin II receptor blocker, candesartan cilexetil, among patients considered intolerant of ACE inhibitors. METHODS: Patients with CHF, left ventricular ejection fraction less than 35%, and history of discontinuing an ACE inhibitor because of intolerance underwent double-blind randomization in a 2:1 ratio to receive candesartan (n = 179) or a placebo (n = 91). The initial dosage of candesartan was 4 mg/d; the dosage was increased to 16 mg/d if the drug was tolerated. A history of intolerance of ACE inhibitor was attributed to cough (67% of patients), hypotension (15%), or renal dysfunction (11%). RESULTS: The study drug was continued for 12 weeks by 82.7% of patients who received candesartan versus 86.8% of patients who received the placebo. This 4.1% greater discontinuation rate with active therapy was not significant; the 95% confidence interval ranged from 4.8% more discontinuation with placebo to 13% more with candesartan. Titration to the 16-mg target dose was possible for 69% of patients who received candesartan versus 84% of those who received the placebo. Frequencies of death and morbidity were not significantly different between the candesartan and placebo groups (death 3.4% and 3.3%, worsening heart failure 8.4% and 13.2%, myocardial infarction 2.8% and 5.5%, all-cause hospitalization 12.8% and 18.7%, and death or hospitalization for heart failure 11.7% and 14.3%). CONCLUSIONS: Candesartan was well tolerated by this population. The effect of candesartan on major clinical end points, including death, remains to be determined.

Aged↗
PubMed2000

Epigenetic aspects of cellular senescence.

The limited proliferative potential of normal cells in culture has been proposed as a model for cellular aging in vivo. It is clear that cellular aging has a genetic component but epigenetic processes could also be involved. Insight gained during years of intensive study suggests cellular aging is a multi-step process and that cells possess a counting mechanism that determines the number of doublings the cells can complete. In this paper, we review evidence suggesting a role for epigenetic processes in cell senescence and discuss the possible insights that might be provided by experiments designed to induce a premature senescent like state.

Biological Clocks↗