Nurit Rosenberg, PhD, Ariella Zivelin, PhD, Angela Chetrit, PhD, Rima Dardik, PhD, Nurit Kornbrot, MSc, Dov Freimark, MD and Aida Inbal, MD
Background: Platelet adhesion and aggregation are mediated by specific platelet membrane glycoproteins GPIa/IIa, GPIba, and GPIIb/IIIa, and are essential steps in thrombus formation and development of acute myocardial infarction.
Objective: To evaluate the risks exerted by each of the following polymorphisms: HPA-1a/b in GPIIIa; 807C/T in GPIa; and HPA-2a/b, VNTR and Kozak C/T in GPIba in young males with AMI..
Methods: We conducted a case-control study of 100 young males with first AMI before the age of 53 and 119 healthy controls of similar age. All subjects were tested for the above polymorphisms.
Results: The allele frequencies of each of the platelet polymorphism were not significantly different between the young men with AMI and the controls. Smoking alone was associated with a 9.97-fold risk, and the presence of at least one metabolic risk factor resulted in a 2.57-fold risk of AMI.
Conclusion: These results indicate that platelet glycoproteins polymorphisms are not an independent risk factor for AMI.
Gabriel Izbicki, MD, David Shitrit, MD, Dan Aravot MD, Gershon Fink, MD, Milton Saute, MD, Leonid Idelman, MD, Ilana Bakal, BA, Jaqueline Sulkes, PhD and Mordechai R. Kramer, MD
Background: Historically, donor age above 55 years has been considered to be a relative contraindication for organ transplantation. The shortage of organs for transplantation has led to the expansion of the donor pool by accepting older donors.
Objectives: To compare the 1 year follow-up in patients after lung transplantation from older donors (>50 years old) and in patients after transplantation from younger donors (± 50 years).
Methods: The study group comprised all adult patients who underwent lung transplantation at the Rabin Medical Center between May 1997 and August 2001. Donors were classified into two groups according to their age: ≤ 50 years (n=20) and > 50 years (n=9). Survival, number and total days of hospitalization, development of bronchiolitis obliterans syndrome, and pulmonary function tests, were examined 1 year after transplantation.
Results: We performed 29 lung transplantations in our center during the observed period. Donor age had no statistically significant impact on 1 year survival after lung transplantation. There was no statistically significant effect on lung function parameters, the incidence of hospitalization or the incidence of bronchiolitis obliterans between both donor age groups at 1 year after transplantation.
Conclusions: Donor age did not influence survival or important secondary end-points 1 year after lung transplantation. By liberalizing donor criteria of age up to 65 years, we can expand the donor pool, while assessing other possible mechanisms to increase donor availability.
Eliezer Golan, MD, Bruria Tal, PhD, Yossef Dror, PhD, Ze’ev Korzets, MBBS, Yaffa Vered, PhD, Eliyahu Weiss, MSc and Jacques Bernheim, MD
Background: Multiple factors are involved in the pathogenesis of hypertension in the obese individual.
Objective: To evaluate the role of a decrease in sympathetically mediated thermogenesis and the effect of the correlation between the plasma leptin and daily urinary nitric oxide levels on obesity-related hypertension.
Methods: We evaluated three groups: 25 obese hypertensive patients (age 45.7±1.37 years, body mass index 34.2±1.35 kg/m2, systolic/diastolic blood pressure 155±2.9/105±1.3, mean arterial pressure 122±1.50 mmHg); 21 obese normotensive patients (age 39.6±1.72, BMI 31.3±0.76, SBP/DBP 124±2.1/85.4±1.8, MAP 98.2±1.80); and 17 lean normotensive subjects (age 38.1±2.16, BMI 22.1±0.28, SBP/DBP 117±1.7/76.8±1.5, MAP 90.1±1.50). We determined basal resting metabolic rates, plasma insulin (radioimmunoassay), norepinephrine (high performance liquid chromatography) in all subjects. Thereafter, 14 obese hypertensives underwent a weight reduction diet. At weeks 6 (n=14) and 14 (n=10) of the diet the above determinations were repeated. Plasma leptin (enzyme-linked immunosorbent assay) and UNOx (spectrophotometry) were assayed in 17 obese hypertensives and 17 obese normotensives, and in 19 obese hypertensives versus 11 obese normotensives, respectively.
Results: Obese hypertensive patients had significantly higher basal RMR and plasma NE levels. Insulin levels were lower in the lean group, with no difference between the hypertensive and normotensive obese groups. At weeks 6 and 14, BMI was significantly lower, as were insulin and NE levels. RMR decreased to values of normotensive subjects. MAP normalized but remained significantly higher than that of obese normotensives. Leptin blood levels and the leptin/UNOx ratio were significantly higher in the obese hypertensive compared to the obese normotensive patients. Both these parameters were strongly correlated to BMI, MAP5, RMR, and plasma NE and insulin .Obese hypertensive patients excreted less urinary NO metabolites. A strong correlation was found between MAP and the leptin/UNOx ratio.
Conclusions: A reduction of sympathetically mediated thermogenesis, as reflected by RMR, results in normalization of obesity-related hypertension. In contrast, insulin does not seem to play a major role in the pathogenesis of hypertension associated with obesity. Increased leptin levels in conjunction with decreased NO production in the presence of enhanced sympathetic activity may contribute to blood pressure elevation in the obese.
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BMI = body mass index
SBP/DBP = systolic blood pressure/diastolic blood pressure
MAP = mean arterial pressure
UNOx = urinary nitric oxide
RMR – resting metabolic rate
NE = norepinephrine
Naomi B. Zak, PhD, Sagiv Shifman, MSc, Anne Shalom, PhD and Ariel Darvasi, PhD, MPH
The complex genetic nature of many common diseases makes the identification of the genes that predispose to these ailments a difficult task. In this review we discuss the elements that contribute to the complexity of polygenic diseases and describe an experimental strategy for disease-related gene discovery that attempts to overcome these factors. This strategy involves a population-based case-control paradigm and makes use of a highly informative, homogeneous founder population, many of whose members presently reside in Israel. The properties of single nucleotide polymorphisms, which are presently the markers of choice, are discussed, and the technologies that are currently available for SNP genotyping are briefly presented.
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SNP = single nucleotide polymorphism
Eduardo Garcua-Garcia, MD, Carlos A. Aguilar-Salinas, MD, Teresa Tusie-Luna, MD, PhD and Juan Antonio Rull-Rodrigo, MD
This review summarizes the clinical, metabolic and genetic characteristics of early-onset type 2 diabetes in Mexico. Early-onset type 2 diabetes is both a clinical challenge and a public health problem. It is calculated that almost 300,000 Mexican diabetics are diagnosed between the ages of 20 and 40. The large Mexican family structure and the high prevalence of the disease provide a unique opportunity to identify the genes and the metabolic abnormalities involved in this form of the disease. In a hospital-based population, our group found that insulin deficiency was the main defect in this form of diabetes. Mutations in the HNF-1α or HNF-4α genes or autoimmunity to the beta cell were found in a small proportion of cases, leaving unexplained the majority of cases. Also discussed are the epidemiologic and therapeutic implications of early-onset type 2 diabetes, and the possible role of genetic testing for prevention.