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Biomedical subjects

J Aaron

Publications and source records attributed to J Aaron.

At least 19 recordsLinked to original sources
PubMed2003

Optical systems for in vivo molecular imaging of cancer.

Progress toward a molecular characterization of cancer would have important clinical benefits; thus, there is an important need to image the molecular features of cancer in vivo. In this paper, we describe a comprehensive strategy to develop inexpensive, rugged and portable optical imaging systems for molecular imaging of cancer, which couples the development of optically active contrast agents with advances in functional genomics of cancer. We describe initial results obtained using optically active contrast agents to image the expression of three well known molecular signatures of neoplasia: including over expression of the epidermal growth factor receptor (EGFR), matrix metallo-proteases (MMPs), and oncoproteins associated with human papillomavirus (HPV) infection. At the same time, we are developing inexpensive, portable optical systems to image the morphologic and molecular signatures of neoplasia noninvasively in real time. These real-time, portable, inexpensive systems can provide tools to characterize the molecular features of cancer in vivo.

Biomarkers, Tumor↗
PubMed2000

The influence of recipe modification and nutritional information on restaurant food acceptance and macronutrient intakes.

OBJECTIVE: To examine the influences of nutritional information and consumer characteristics on meal quality expectations, food selection and subsequent macronutrient intakes of consumers offered a reduced-fat option in a restaurant. DESIGN: A target, full-fat (FF) main restaurant meal option was developed in a version substantially reduced in fat and energy (RF). Restaurant patrons were randomly placed into one of four treatment groups varying in provision of menu information about the target dish, and the actual version of that dish served (if ordered). A full-fat blind (FFB) control group was given no nutritional information in the menu and was served the FF version. The other three groups were all served the modified RF version: (i) reduced-fat blind (RFB), who were given no nutritional information; (ii) reduced-fat informed (RFI), who were given nutritional information; and (iii) reduced-fat informed with details (RFID), who were given the same nutritional information plus recipe modification details. Subjects rated their expected and actual liking, the pleasantness of taste, texture and appearance of the dish, how well the dish matched their expectations, and the likelihood of purchase again. Additional measures included the other dish selections, sociodemographic and attitudinal information. SETTING: A silver service (training) restaurant. SUBJECTS: Members of the public (n = 279) consuming meals in the restaurant. RESULTS: The presence of nutritional information on the menu did not significantly increase subsequent intakes of energy and fat from the rest of the meal, and did not significantly influence sensory expectations or post-meal acceptance measures (which also did not differ between the FF and RF versions). Consumer characteristics relating to fat reduction attitudes and behaviours were significantly related to the selection of different dishes. CONCLUSIONS: Provision of RF alternatives in a restaurant can have significant positive dietary benefits. Menu nutritional information did not affect measures of meal acceptance. Further studies should identify which types of information formats might be most effective in enhancing the selection of 'healthy' options.

Cooking↗
PubMed1999

Queuing for coronary angiography during severe supply-demand mismatch in a US public hospital: analysis of a waiting list registry.

CONTEXT: Adverse cardiac events have been reported in patients waiting for either coronary surgery or angioplasty. However, data on the risk of adverse events while awaiting coronary angiography are limited, and none are available from a US population. OBJECTIVE: To quantify cardiac outcomes in patients waiting for elective coronary angiography. DESIGN, SETTING, AND PARTICIPANTS: Observational cohort study of 381 adult outpatients (mean [SD] age, 55 [12] years; 64% male; 61% white) on a waiting list for coronary angiography at a US tertiary care public teaching hospital during 1993-1994. MAIN OUTCOME MEASURES: Rates of cardiac death, nonfatal myocardial infarction, and hospitalizations for unstable angina or heart failure as a function of amount of time spent on a waiting list. RESULTS: Sixty-six patients were dropped from the waiting list but were included in the study analysis. During a mean (SD) follow-up of 8.4 (6.5) months, cardiac death, myocardial infarction, and hospitalization occurred in 6 (1.6%), 4 (1.0%), and 26 (6.8%) patients, respectively. The probability of events was minimal in the first 2 weeks and increased steadily between 3 and 13 weeks. By Cox multivariate analysis, 2 variables independently identified an increased risk of adverse events: a strongly positive treadmill exercise electrocardiogram or positive stress imaging result at referral (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.22-4.16; P=.01) and the use of 2 to 3 anti-ischemic medications (OR, 1.98; 95% CI, 1.19-3.96; P=.04). Among 311 patients who ultimately underwent angiography, those with adverse events had a higher prevalence of coronary disease (96% vs 60%; P<.001), more frequently required revascularization (93% vs 53%; P<.001), and had longer hospital stays (mean [SD], 6.2 [4.3] vs 1.3 [0.7] days; P=.001). CONCLUSION: Our data suggest that in a cohort referred for coronary angiography, delaying the procedure places some patients at risk for death, myocardial infarction, unplanned hospitalization, a longer hospital stay, and, potentially, a poorer prognosis. Waits longer than 2 weeks should be avoided, and patients with strongly positive stress test results and those who require 2 to 3 anti-ischemic medications should be prioritized for early intervention.

Aged↗
PubMed1999

Posttraumatic stress in children following acute physical injury.

OBJECTIVE: To prospectively assess the presence of posttraumatic stress disorder (PTSD) in children hospitalized following acute physical injury. The focus was identification of the incidence of PTSD, PTSD symptoms, and exploration of factors associated with development of PTSD symptoms and disorder. METHOD: Forty children ages 8-17 were interviewed approximately 1 month following a serious injury and assessed for PTSD, pretrauma behavior problems, levels of peritraumatic fear, and posttraumatic thought suppression. RESULTS: Twenty-two and a half percent of participants met DSM-IV diagnostic criteria for PTSD; 47.5% met criteria for at least two of the three PTSD symptom clusters. Greater thought suppression was associated with increased symptoms of PTSD, as were the child's peritraumatic fear response and pretrauma internalizing behaviors. CONCLUSIONS: Results suggest that many children who have been hospitalized for physical trauma may be experiencing clinically significant PTSD symptomatology and may benefit from psychological as well as medical intervention.

Adolescent↗
PubMed1996

Restenosis following percutaneous revascularization--the potential role of thrombin and the thrombin receptor.

Thrombin is present at sites of vascular injury and elicits many effects which may contribute to neointimal growth. Further studies are needed to order to determine steps involved in thrombin-induced effects and to identify potential sites to regulate these effects. The failure of the Helvetica trial to demonstrate an effect of treatment with hirudin on restenosis may relate more to our inability to safely inhibit thrombin than to a lack of a role for thrombin in restenosis. A therapy which enables safe and effective control of thrombin-induced responses following vascular injury may yet prove effective at reducing restenosis following percutaneous coronary revascularization.

Angioplasty, Balloon, Coronary↗
PubMed1993

Rationale for the use of clodronate in osteoporosis.

Bisphosphonates are widely used in disorders associated with increased resorption of bone, particularly in Paget's disease of bone and in the hypercalcemia of malignancy. Because of their undoubted efficacy and relatively low toxicity, bisphosphonates are attractive candidates for the management of osteoporosis. Clodronate, one of the many bisphosphonates being tested in osteoporosis, may be given intravenously or by mouth. In contrast to etidronate, even high doses of clodronate do not impair the mineralization of bone, making it suitable for long-term use in osteoporosis. As do all the bisphosphonates tested thus far, clodronate appears to delay the rate of bone loss in osteoporosis. Long-term studies are relatively few, so that its steady-state effects on bone mass are not yet known. Most data suggest clodronate is capable at least of delaying the rate of bone loss, but several pilot studies with this agent suggest that increments of bone mass might be sustainable for several years. Clodronate is likely to decrease the frequency of osteoporotic fractures, but there is no evidence for this at present. Well-controlled, long-term prospective studies are needed.

Bone Remodeling↗
PubMed1989

[The role of aluminum-induced inhibition of the intestinal absorption of calcium in the pathogenesis of aluminum osteopathy].

The aim of the study was to investigate the effect of aluminium on duodenal calcium absorption, the impairment of which can represent a pathogenic factor in the development of aluminium bone lesions. The authors investigated in the chick the effect of Al(OH)3 administered orally and of AlCl3 administered subcutaneously on the duodenal absorption of 47Ca, on serum concentration of calcium, phosphorous, aluminium and 1,25-dihydroxycholecalciferol and on bone morphology. Oral administration of Al(OH)3 for 8, 15, and 22 days was without any significant change. Subcutaneous administration of Al/Cl/3 for 8 day was associated with a significant increase in serum aluminium and 1,25-dihydroxycholecalciferol levels and with a significant decrease of the duodenal absorption of 47Ca. Decreased intestinal absorption of calcium may play a pathogenic role in the development of aluminium osteopathy. Increased serum 1,25-dihydroxycholecalciferol reflects presumably a compensatory mechanism of the lowered calcium absorption.

Aluminum↗
PubMed1984

NMR imaging in temporal lobe epilepsy due to gliomas.

Magnetic resonance (MR) imaging has been shown to have greater sensitivity than X-ray CT in a broad range of intracranial pathologic processes. In regions in which CT is likely to suffer degradation of image quality due to a variety of bone artifacts, the advantages of MR are even more striking. Previous reports have emphasized the relative advantages of MR in studies of the posterior fossa. The present report documents the potential for similar advantages of MR in demonstration of middle fossa anatomy and in identification and characterization of temporal lobe lesions. In three patients with anterior temporal lobe gliomas and temporal lobe epilepsy, MR (even with the use of an early prototype, resistive system of 0.15 T) was clearly superior to contrast-enhanced CT in demonstrating the pathology. This considerably assisted preoperative evaluation.

Adolescent↗
PubMed1984

Bone formation and resorption as the determinants of trabecular bone volume in normal and osteoporotic men.

Trabecular bone volume, forming surface and percent surface resorption have been determined in iliac crest samples obtained post mortem from 43 young men and 49 elderly men and in biopsies obtained from 22 males with spinal osteoporosis. The mean bone volume was significantly lower in the old than in the young controls and significantly lower again in the osteoporotic cases. Forming surfaces were significantly lower in the old than the young controls but were not different as between old controls and cases of osteoporosis. Percent surface resorption was the same in young and old controls but significantly increased in the osteoporotics. Multiple regression analysis showed that trabecular bone volume was a significant positive function of forming surface and a significant inverse function of fractional surface resorption. Age-related (simple) osteoporosis in men appears to be due to reduced bone formation whereas pathological (accelerated) osteoporosis is due to increased bone resorption.

Adult↗
PubMed1981

Bone formation and resorption as the determinants of trabecular bone volume in postmenopausal osteoporosis.

Histomorphometry has been applied to trabecular bone samples obtained post-mortem from young and old women without known bone disease and to bone biopsy specimens from patients with postmenopausal osteoporosis. Bone volume was significantly lower in the old than young controls and significantly lower again in the osteoporotics. The loss of bone with age associated with a rise in surface resorption but no change in forming surface, and the further loss in osteoporotics was associated with a further rise in resorption and a small non-significant fall in forming surfaces. It is suggested that trabecular bone volume is determined by the relation between total forming surface on the one hand and percent surface resorption on the other, and this relationship is expressed in mathematical terms. Age-related bone loss (simple osteoporosis) in women is accounted for by increased resorption, and accelerated osteoporosis is mainly due to a further increase in resorption.

Adult↗
PubMed1977

Prophylactic 1alpha-hydroxyvitamin D3 therapy in haemodialysis patients.

Twenty-seven patients starting regular haemodialysis were treated with a 1 microgram daily dose of 1alpha-hydroxyvitamin D3 and concurrent aluminium hydroxide therapy to prevent hyperphosphataemia. There was an increase in plasma calcium, but no significant improvement in plasma alkaline phosphatase activity or parathyroid hormone levels. Metastatic calcification progressed but was never a severe clinical problem. Quantitative bone histology showed a significant decrease in resorptive surfaces confirmed radiologically, but there was no significant decrease in forming surfaces. The expected increase in forming surfaces with length of dialysis was however prevented.

Adolescent↗