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Biomedical subjects

A Landry

Publications and source records attributed to A Landry.

11 recordsLinked to original sources
PubMed2006

3D ultrasound analysis of carotid plaque volume and surface morphology.

Morphological characterization of carotid plaques has been used for risk stratification and evaluation of response to therapy, evaluation of new risk factors, genetic research, and for quantifying effects of new anti-atherosclerotic therapies. We developed a 3D US system that allows detailed studies of carotid plaques in 3D. Our software includes 3D reconstruction, viewing, manual and semi-automated segmentation of carotid plaques, and surface morphology analysis to be used for quantitative tracking of plaque changes. We evaluated our plaque quantification software by examining plaque volume measurement accuracy, variability, and plaque surface morphology. We used vascular test phantoms to study segmentation accuracy, and used 48 3D US carotid plaques of patients ranging in size from 13.2 mm(3) to 544.0 mm(3) to study plaque volume measurement variability. We compared results from the semi-automated plaque measurements to the results obtained from manual measurements, which were used as the "gold" standard. We developed a surface plaque morphology quantification technique based on the segmented plaque surface curvature and used it to analyze plaques. Accuracy of plaque volume measurements for the simulated plaques ranged from 4.2% to 1.5% for volumes ranging from 68.5 mm(3) to 286 mm(3). The variability study showed that coefficients of variation in the measurement of plaque volume decreased with increasing plaque size for both inter- (90.8-3.9%) and intra-observer (70.2-3.1%) measurements over the plaque sizes measured. Surface morphology analysis showed that 1 mm ulceration could be quantified and monitored for changes over time. The automated plaque quantification approach showed a little higher intra-observer variability than the manual technique, and its performance was better for segmenting the wall than the lumen. Our results indicate that our approach is sensitive tool and can be used in studies of plaque progression and regression as it relates to atherosclerosis treatment effects and can be used effectively in longitudinal studies for direct measurement carotid plaque volume.

Algorithms↗
PubMed2006

Macrophage-conditioned medium inhibits the differentiation of 3T3-L1 and human abdominal preadipocytes.

AIMS/HYPOTHESIS: In obesity, a limited adipogenic capacity may promote adipocyte hypertrophy and increase the risk of insulin resistance and type 2 diabetes. Recent data indicate that macrophages reside within adipose tissue in obese rodents and humans. We hypothesised that secreted macrophage factors may inhibit adipogenesis. MATERIALS AND METHODS: Conditioned media from cultured murine J774 or human THP-1 macrophages were collected, and added to either murine 3T3-L1 preadipocytes or human abdominal stromal preadipocytes from subcutaneous or omental fat depots. RESULTS: Macrophage-conditioned medium (MacCM) strongly inhibited 3T3-L1 adipogenesis. Dose-response studies with J774-MacCM revealed that 80 and 100% of J774-MacCM completely suppressed triacylglycerol accumulation as well as the induction of fatty acid synthase, peroxisome proliferator-activated receptor gamma, CCAAT/enhancer binding protein alpha, and adiponectin. Similar inhibitory effects on 3T3-L1 preadipocytes were observed with THP-1-MacCM. Differentiation of human abdominal subcutaneous stromal preadipocytes was moderately reduced (subcutaneous>omental) by J744-MacCM. In contrast, the differentiation of both subcutaneous and omental stromal preadipocytes was completely inhibited by THP-1-MacCM, as determined on the basis of morphology and triacylglycerol accumulation, as well as fatty acid synthase and adiponectin protein expression. CONCLUSIONS/INTERPRETATION: Secreted macrophage products inhibit the differentiation of 3T3-L1 preadipocytes as well as human abdominal stromal preadipocytes.

3T3 Cells↗
PubMed2000

Introducing an evaluation of community based occupational therapy services: a client-centred practice.

The results of a study conducted in 1996 by the "Groupe de recherche en ergothérapie communautaire" (GREC), indicate that the quality of occupational therapy services in community settings is infrequently evaluated. A conceptual framework supporting such a process is presented in the context of client-centered services with a focus on continuous health care improvement. Both the research process leading to the design of an assessment tool, and its congruence with the beliefs and values of the profession, are explored. Finally, some issues relating to the implementation of a formal evaluation process are discussed.

Community Health Services↗
PubMed1999

Caught up in uroweb.

Emphasizing "interactive exchange and discussion" among urologists worlwide, the mission of Uroweb (www.uroweb.org) is to be a global resource for urologic specialists and investigators, although the content is mostly from urologists in Europe and the United States. The European Association of Urology, which developed this World Wide Web site, notes it was born out of the desire to link educational and practical treatment information from a wide variety of sources.

Journal Article↗
PubMed1997

Minimally invasive direct coronary artery bypass surgery.

Three patients with isolated disease of the left anterior descending coronary received a minimally invasive direct coronary artery bypass operation. All were discharged from the hospital in 2 days and are doing well. This is an exciting new procedure which combines the long-term benefits of bypass using the mammary artery with a shortened hospital stay and a rapid postoperative recovery.

Coronary Artery Bypass↗
PubMed1996

Everyday memory following traumatic brain injury.

Residual memory deficits may represent a problem to the everyday functioning of a large number of people, including those who have sustained traumatic brain injury (TBI). The present exploratory study sought to investigate the interrelationships between subjective memory reports, performance on traditional memory tests, and performance on tests of prospective memory. These interrelationships were contrasted between a group of 24 adults who had sustained TBI and a group of 24 matched control subjects. Prospective memory was hypothesized to be indicative of everyday memory functioning. The results provided preliminary evidence that prospective memory tests are sensitive to TBI-related neurological impairment and, in comparison to traditional tests, may be better indicators of functional memory capacity. This pattern was particularly true for control subjects, possibly because TBI subjects had difficulties in evaluating their memory functioning.

Activities of Daily Living↗
PubMed1985

Optimal technetium-99m RBC labeling for gastrointestinal hemorrhage study.

Four methods of Tc-99m red blood cell labeling were tested for labeling efficiency and kinetics in normal adults. From a perspective of the gastrointestinal hemorrhage study, the in vivo method was least appropriate because of extravascular loss of pertechnetate. The modified in vitro method was disadvantageous because of long labeling intervals in a syringe fixed to the patient's forearm (45 minutes). The pure in vitro methods produced the highest labeling efficiency (95% +) and are preferred by the authors.

Erythrocytes↗
PubMed1984

Scintigraphy of gastrointestinal hemorrhage: superiority of 99mTc red blood cells over 99mTc sulfur colloid.

The relative efficacy of 99mTc sulfur colloid and in vitro-labeled 99mTc red blood cells in detecting and localizing gastrointestinal hemorrhage was evaluated in a prospective tandem study of 100 patients referred for suspicion of gastrointestinal tract hemorrhage. Thirty-eight true-positive scintigrams were obtained with 99mTc red blood cells, whereas 99mTc sulfur colloid detected only five sites of hemorrhage. Scintigraphic findings were corroborated by clinical, endoscopic, arteriographic, and surgical findings. 99mTc red blood cells were clearly superior, with a sensitivity of 93%, specificity of 95%, and overall accuracy of 94% in detecting and localizing gastrointestinal hemorrhage.

Adolescent↗