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Biomedical subjects

R Gabbay

Publications and source records attributed to R Gabbay.

5 recordsLinked to original sources
PubMed2000

Association between mitral annulus calcification and peripheral arterial atherosclerotic disease.

The authors previously demonstrated a significant association between the presence of mitral annulus calcification (MAC) and aortic atheroma, carotid atherosclerotic disease, and coronary artery disease. The present study was designed to determine whether an association exists between MAC and peripheral arterial atherosclerotic disease. Of the 805 patients in whom the diagnosis of MAC was made by transthoracic echocardiography between 1995 and 1997, 77 patients (40 men and 37 women; mean age, 73.1 +/- 11.4 years; range, 44-90 years) underwent peripheral arterial testing for various indications, and comprised the study group. They were compared with 58 age-matched and sex-matched patients without MAC (30 men and 28 women; mean age, 73.2 +/- 11.8 years; range, 31-93 years) who underwent peripheral arterial testing during the same period for the same indications (control group). MAC was defined as a dense, localized, highly reflective area at the base of the posterior mitral leaflet detected by transthoracic echocardiography. An ankle/brachial systolic pressure index (ABI) was calculated by dividing the higher dorsalis pedis or posterior tibial Doppler-derived pressures by the higher of the 2 upper extremity systolic pressures. ABI was graded as follows: normal > or = 1, abnormal < 1, mild 0.71 to 0.99, moderate 0.41 to 0.7, and severe < or = 0.4. No differences were found between the groups in indications for referral for peripheral arterial testing and in risk factors for atherosclerosis except for hypertension, which was found to be significantly more prevalent in the study group (66% vs 41%, p = 0.004). The study group included 151 limbs, and the control group included 113 limbs. The mean ABI was significantly lower for all limbs in the MAC group (0.56 +/- 0.27 vs 0.87 +/- 0.24, p = 0.0001), abnormal ABI < 1 (94% vs 68%, p = 0.001), moderate peripheral arterial disease (44% vs 25%, p = 0.001), and a severe disease (27% vs 1%, p = 0.001). Of the 77 patients with MAC, 73 (95%) had a disease (right and/or left limbs) compared with 40 of 58 (69%) in the control group (p = 0.001). Bilateral disease (Doppler index < 1 for both right and left limbs), and severe bilateral disease (Doppler index < or = 0.4 for both right and left limb) were also found to be significantly more prevalent in the MAC group (87% vs 60%, p = 0.001; and 12% vs 0%, p = 0.007, respectively). There is a significant association between the presence of MAC and peripheral arterial disease. This information strengthens our hypothesis that MAC may be an important marker for generalized vascular atherosclerotic disease.

Adult↗
PubMed2000

Disease management for diabetes mellitus: impact on hemoglobin A1c.

OBJECTIVE: To describe outcomes associated with a health maintenance organization (HMO)-sponsored disease management program for diabetes. STUDY DESIGN: Descriptive study that compared outcomes of patients with diabetes before and after entry into a disease management program. PATIENTS AND METHODS: The study was conducted in a mixed-model HMO with 275,000 members. The disease management program included a Steering Committee, clinical guidelines, primary care site-based diabetes education, coverage of glucose meters and strips, simplified outcomes reporting, and support of clinical leadership. Data were obtained for 5332 continuously enrolled patients who voluntarily entered the disease management program; 3291 patients (61.7%) received 3 months or more of follow-up, and 663 (12.4%) received 1 year or more of follow-up. The primary outcomes were change from baseline of mean hemoglobin A1c (HbA1c) and medication use after 3 months and 1 year of follow-up. RESULTS: The mean baseline HbA1c for all program participants was 8.51% (standard deviation [SD] = 1.86%). At 3 months of follow-up, the mean HbA1c value for 2794 of 3291 participants (84.0%) had decreased to 7.41% (SD = 1.33%; P = .0001). At 1 year of follow-up, the HbA1c value, available for 605 of 663 patients (91.3%), had decreased from a mean baseline value of 8.76% (SD = 1.87%) to 7.41% (SD = 1.24%; P = .0001). Among 663 patients with 1 year of follow-up, insulin use increased from 30.0% to 31.6%, and sulfonylurea use decreased from 40.7% to 33.8%. Troglitazone and metformin use increased from 7.7% and 23.8%, respectively, to 16.4% and 28.8%, respectively. CONCLUSIONS: Our data suggest that a multifaceted disease management program for diabetes can result in significant short-term improvements in glycemic control in the managed care setting. While the improvement in the HbA1c was accompanied by an increase in the use of insulin, troglitazone, and metformin, we suggest the influence of disease management on glycemic control among our participants was significant and should be considered in future studies in this area.

Adolescent↗
PubMed1996

Cloning and characterization of the cDNA for lycopene beta-cyclase from tomato reveals decrease in its expression during fruit ripening.

The cDNA which encodes lycopene cyclase, CrtL, was cloned from tomato (Lycopersicon esculentum cv. VF36) and tobacco (Nicotiana tabacum cv. Samsun NN) and functionally expressed in Escherichia coli. This enzyme converts lycopene to beta-carotene by catalyzing the formation of two beta-rings at each end of the linear carotene. The enzyme interacts with half of the carotenoid molecule and requires a double bond at the C-7,8 (or C-7,8') position. Inhibition in E. coli indicated that lycopene cyclase is the target site for the inhibitor MPTA, 2-(4-methylphenoxy)tri-ethylamine hydrochloride. The primary structure of lycopene cyclase in higher plants is significantly conserved with the enzyme from cyanobacteria but different from that of the non-photosynthetic bacteria Erwinia. mRNA of CrtL and Pds, which encodes phytoene desaturase, was measured in leaves, flowers and ripening fruits of tomato. In contrast to genes which encode enzymes of early steps in the carotenoid biosynthesis pathway, whose transcription increases during the 'breaker' stage of fruit ripening, the level of CrtL mRNA decreases at this stage. Hence, the accumulation of lycopene in tomato fruits is apparently due to a down-regulation of the lycopene cyclase gene that occurs at the breaker stage of fruit development. This conclusion supports the hypothesis that transcriptional regulation of gene expression is a predominant mechanism of regulating carotenogenesis.

Amino Acid Sequence↗