Israel Medical Association Journal

Background: In lipid oxidation kinetics studies, prevalent cardiovascular disease has been associated with shortened lag phase, the length of time preceding the onset of oxidation.

Objectives: To examine, in vitro, copper-induced lipid oxidation kinetics in unfractionated serum from hemodialysis patients and to determine differences in kinetic parameters between patients with and without a history of CVD[1].

Methods: Of the 76 patients enrolled in a study of oxidative stress in hemodialysis (44/76 with prevalent CVD, 53/76 males), 9 males with a history of myocardial infarction were selected and matched for age, diabetes and smoking status with 9 males from the non-CVD group. The kinetics of lipid oxidation was studied. Blood chemistry determinations including serum lipids, lipoproteins, hemostatic factors and serum malondialdehyde were obtained. Variables were compared using the t-test for independent samples with history of MI[2] entered as the categorical variable.

Results: Tmax, the oxidation kinetic parameter defined as the time at which the rate of absorbing product accumulation was maximal, was significantly shorter in dialysis patients with a history of MI than in those without (115.2 ± 38.5 vs. 162.7 ± 48.9 minutes, P = 0.04). Further, Tmax and MDA[3] were negatively correlated to one another (r = -0.47, P = 0.04). Odds ratios indicate that each 1 minute increase in Tmax was associated with a 3% decrease in odds that a subject had a history of MI.

Conclusions: These findings indicate the presence of increased oxidative stress in hemodialysis patients with a history of MI.

Background: Cardiac surgery is being performed with increasing frequency in patients aged 80 years and older.

Objectives: To examine the long and short-term results of surgery in this age group.

Methods: We retrospectively investigated 202 consecutive patients aged 80 years or older who underwent cardiac surgery between 1991 and 1999. Ninety-six operations (48%) were urgent.

Results: The study group comprised 140 men (69%) and 62 women (31%) with a mean age of 82.1 years (range 80–89). Preoperatively, 120 patients (59%) had unstable angina, 37 (18%) had left main coronary artery disease, 22 (11%) had renal failure, 17 (8.5%) had a history of stroke, and 13 (6.5%) had previous cardiac surgery. Hospital mortality for the whole group was 7.4%. Postoperative complications included: re-exploration for bleeding in 15 (7.4%), stroke in 8 (4%), sternal wound infection in 3 (1.5%), low cardiac output in 17 (8.4%), new Q wave myocardial infarction in 5 (2.5%), renal failure in 17 (8.5%), and atrial fibrillation in 71 (35%). The actuarial survival for patients discharged from the hospital was 66% at 5 years and 46% at 8 years. The type of surgical procedure was significantly associated with increased early mortality (coronary artery bypass grafting only in 2.9%, CABG[1] + valve in 16.1%, valve only in 16.7%; P = 0.01). Significant predictors (P < 0.05) for late mortality included type of surgical procedure, congestive heart failure, and postoperative low cardiac output.

Conclusions: When appropriately applied in selected octogenarians, cardiac surgery can be performed with acceptable mortality and good long-term results.

Background: An organ sharing system should achieve fairness and optimal graft longevity. Balancing between social and utilitarian considerations is a sensitive ethical, public and medical issue that requires a means to examine the consequences of any allocation policy or planned changes thereof.

Objective: To evaluate the performance and applicability of a computerized simulation model by examining the impact of two opposing organ allocation policies (social or utilitarian) on predicted organ distribution regarding age, waiting time, recipient sensitization measured by panel reactive antibody level and overall donor-recipient tissue matching (measured by the number of HLA antigen mismatches).

Methods: Using a computerized simulation model, virtual donors and recipients were emulated and organs were allocated according to either social algorithms or utilitarian policies. The resulting number of HLA mismatches, PRA[1], age, and waiting time distributions were compared between allocation strategies.

Results: Simulating allocation of 7,000 organs to 17,000 candidate recipients and implementing social policies yielded donor-recipient compatibility comparable to utilitarian policies (0–1 mm: 19.4% vs. 28%) while allocating 66.7% of organs to long waiters (>48 months).

Conclusion: This computerized simulation model is a valuable tool for decision-makers establishing or modifying organ allocation policies.

Background: Familial Mediterranean fever is an autosomal recessive disease characterized by recurrent attacks of fever and serositis. The disease is caused by mutations in the MEFV gene, presumed to act as a down-regulator of inflammation within the polymorphonuclear cells.

Objectives: To present the results of 412 FMF patients genotyped for three MEFV mutations, M694V, V726A and E148Q.

Results: The most frequent mutation, M694V, was detected in 47% of the carrier chromosomes. This mutation, especially common among North African Jewish FMF[1] patients, was not found in any of the Ashkenazi (East European origin) patients. Overall, one of the three mutations was detected in 70% of the carrier chromosomes. M694V/M694V was the most common genotype (27%), followed by M694V/V726A (16%). The full genotype could be assessed in 57% of the patients, and one disease-causing mutation in an additional 26%. Only one patient with the E148Q/E148Q genotype was detected despite a high carrier rate for this mutation in the Jewish population, a finding consistent with a low penetrance of this genotype. The M694V/M694V genotype was observed in 15 patients with amyloidosis compared to 4 amyloidosis patients with other genotypes (P < 0.0001).

Conclusions: Because of low penetrance and as yet other undetermined reasons, mutation analysis of the most common MEFV mutations supports a clinical diagnosis in only about 60% of patients with definite FMF.

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Background: Decreased elasticity of the aorta is associated with aging and several risk factors of atherosclerosis. The data regarding this phenomenon in patients with familial hypercholesterolemia are rather sparse.

Objectives: To evaluate non-invasively the elasticity of the proximal ascending aorta of 51 heterozygous FH[1] patients compared to 42 normal age and gender-matched controls.

Methods: Aortic elasticity was estimated by transthoracic echocardiography using the “pressure-strain” elastic modulus and aortic strain formulas.

Results: The elastic modulus score was higher in the FH group than in the controls (1.12 ± 0.91 10⁶ dynes/cm² vs. 0.65 ± 0.46 10⁶ dynes/cm² respectively, P = 0.01). This was consistent in both the pediatric (0.5 ± 0.2 10⁶ dynes/cm² vs. 0.4 ± 0.1 10⁶ dynes/cm² respectively, P = 0.009) and adult subgroups (1.3 ± 1.0 10⁶ dynes/cm² vs. 0.8 ± 0.5 10⁶ dynes/cm² respectively, P = 0.0004). Aortic strain was significantly lower in patients with FH than in controls (6 ± 4% vs. 9 ± 5% respectively, P = 0.0002). These findings reflected decreased elasticity of the proximal ascending aorta in the FH patients. In multivariate analysis, age, serum cholesterol level and serum triglycerides level were the independent predictors of the elastic modulus score, whereas age was the predictor of aortic strain.

Conclusions: The elasticity of the proximal ascending aorta is decreased in heterozygous FH patients.

Background: Cystinuria is an autosomal recessive disease that is manifested by the development of kidney stones. Mutations in SLC3A1 cause type I disease, while mutations in SLC7A9 are associated with non-type I disease. In Israel cystinuria is especially common among Libyan Jews who suffer from non-type I disease.

Objectives: To compare clinical manifestations of patients with mutations in SLC3A1 to those with mutations in SLC7A9, and to assess the carrier rate among unaffected Libyan Jewish controls.

Methods: Clinical manifestations were evaluated in patients with mutations in SLC3A1 and in patients with mutations in SLC7A9. Carrier rates for two SLC7A9 mutations were assessed in 287 unaffected Libyan Jewish controls.

Results: Twelve patients with mutations in SLC3A1 were compared to 15 patients with mutations in SLC7A9. No differences were detected between the patients with mutations in SLC3A1 and those with mutations in SLC7A9 in relation to the age of disease onset, the estimated number of stones, the number of invasive procedures, the number of patients receiving drug therapy, or the patients’ urinary pH. Eleven of the unaffected Libyan Jewish controls were found heterozygotes for the V170M mutation, establishing a carrier rate of 1:25. The 1584+3 del AAGT mutation was not found in any of the Libyan Jewish controls.

Conclusion: Mutations in SLC3A1 and SLC7A9 cystinuria patients result in indistinguishable disease manifestations. The high carrier rate among Libyan Jews is a result of a single missense mutation, V170M.