Israel Medical Association Journal

Background: Hyperlipidemia is a major risk factor for coronary heart disease. Reducing low density lipoprotein-cholesterol can significantly reduce the risk of CHD[1], but many patients fail to reach the target LDL-C[2] goals due to low doses of statins or low compliance.

Objectives: To treat high risk patients with atorvastatin in order to reach LDL-C goals (either primary or secondary prevention) of the Israel Atherosclerosis Society.

Methods: In this open-label study of 3,276 patients (1,698 of whom were males, 52%), atorvastatin 10 mg was given as a first dose, with follow-up and adjustment of the dose every 6 weeks. While 1,670 patients did not receive prior hypolipidemic treatment, 1,606 were treated with other statins, fibrates or the combination of both.

Results: After 6 weeks of treatment, 70% of the patients who did not receive prior hypolipidemic medications and who needed primary prevention reached target LDL-C levels. Interestingly, a similar number of patients on prior hypolipidemic treatment reached the LDL-C goals for primary prevention. The patients treated with other statins, fibrates or both did not reach the LDL-C treatment goals. Only 34% of all patients who needed secondary prevention reached the ISA[3] LDL-C target of 100 mg/dl. Atorvastatin proved to be completely safe; only two patients had creatine kinase elevation above 500 U/L, and another six had mild CK[4] elevation (<500 U/L). None of the patients had clinical myopathy, and only one had to be withdrawn from the study.

Conclusion: Atorvastatin is a safe and effective drug that enables most patients requiring primary prevention to reach LDL-C goal levels, even with a low dose of 10 mg. Patients in need of secondary prevention usually require higher doses of statins.

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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[1] 31.3±0.76, SBP/DBP[2] 124±2.1/85.4±1.8, MAP[3] 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[4] (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[5] and plasma NE[6] 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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[1] BMI = body mass index

[2] SBP/DBP = systolic blood pressure/diastolic blood pressure

[3] MAP = mean arterial pressure

[4] UNOx = urinary nitric oxide

[5] RMR – resting metabolic rate

[6] NE = norepinephrine

Background: Case-control and prospective studies indicate that an elevated plasma homocysteine level is a powerful risk factor for atherosclerotic vascular diseases. Certain medications can induce hyperhomocystinemia, such as methotrexate, trimethoprim and anti-epileptic drugs. There are few reports indicating an interaction between lipid-lowering drugs (cholestyramine and niacin) and homocysteine. Recently, an interaction was shown between fenofibrate and benzafibrates (a fibric acid derivative) and homocysteine plasma levels.

Objectives: To evaluate the effects of different fibrates on plasma homocysteine levels and to measure the reversibility of this effect.

Methods and Results: We investigated the effects of ciprofibrate and bezafibrate on homocysteine levels in patients with type IV hyperlipidemia and/or low high density lipoprotein levels. While a 57% increase in homocysteine was detected in the ciprofibrate-treated group (n=26), a 17% reduction n homocysteine was detected in the group treated with bezafibrate (n=12). The increase in homocysteine in the ciprofibrate-treated group was sustained for the 12 weeks of treatment and was partially reversible after 6 weeks of discontinuing the ciprofibrate therapy.

Conclusions: These results indicate that an increase In plasma homocysteine levels following administration of flbrates is not a class effect, at least in its magnitude. Moreover, it is reversible upon discontinuation of the treatment.
 

Background: Alkaline tide is the transient increase in blood and urine pH following stimulation of gastric acid secretion. It is attributed to HC0₃ release from parietal cells in parallel with H+ secretion. The enzyme carbonic anhydrase is thought to be responsible for HC0₃ production from CO₂ and 0H in the parietal cell.

Objective: To examine the effect of pretreatment with the carbonic anhydrase inhibitor, acetazolamide, on the alkaline tide phenomenon.

Methods: Ten patients with dyspepsia and demonstrable alkaline tide were tested on three separate days. The pH and base excess were determined in arterialized venous blood before and 45 minutes after an intramuscular injection of pentagastrin. The pH of the urine was measured before and 120 mm after pentagastrin injection. Measurements were performed after pentagastrin alone on day 1 following pretreatment with acetazolamide 60 mm before pentagastrin on day 2, and after the administration of acetazolamide alone on day 3.

Results: Following the administration of pentagastrin alone, the blood base excess increased by 1.61 +0.2 mEq/L (mean + standard deviation) and the calculated alkaline tide at 45 mm was 33.99 ±4.49 mEq. On day 2 with prior adminis­tration of acetazolamide, base excess decreased by 0.21 + 0.39 mEq/L, and the calculated alkaline tide was -3.28±7.57 mEq, which was significantly lower than on day 1 (P=0 0001). On day 3, following acetazolamide alone, the base excess values decreased by 0.53~0.2 mEq/L and the alkaline tide was -10.05 +3.33 mEq there was no significant difference compared with day 2 (P= 0.44).

Conclusion: Pretreatment with acetazolamide abolished the alkaline tide induced by pentagastrin. This finding supports the view that carbonic anhydrase has a major role in the alkaline tide phenomenon.

Background: Tumor necrosis factor is associated with various local and systemic inflammatory sequelae following snakebite. Xanthine oxidase is a principal mediator of remote tissue injury (e.g., lungs, heart, liver).

Objective: To investigate in a snakebite-like animal model the as yet unexplored role of TNF and XO in mediating organ damage following snakebite.

Methods: Sprague-Dawley rats were injected intramuscularly with a non-lethal 500 g/kg dose of Vipera aspis venom (n=10) or saline (n=10). Blood pressure and heart rate were continuously monitored, TNF- was measured in the blood, and total XO + xanthine dehydrogenase activity was assessed in various tissues. Lung histology and permeability indices were analyzed.

Results: Venom injection caused a significant (P0.05) reduction in both heart rate and invasive arterial pressure. The blood circulating TNF levels were significantly higher in the intoxicated group (P0.05 vs. saline group), with changes seen at 30 minutes from intoxication in both groups. Total XO + XDH activity in the kidney, lung and liver of the venom-injected group was significantly (P0.05) higher than in the saline group, while the activity in the heart was similar.

Conclusions: The mediation of remote organ and hemodynamic changes following intramuscular injection of a non-lethal dose of Vipera aspis venom can be attributed partly to TNF and partly to XO. More research is needed to better understand the role of either compound and the time frame of their activity before specific antagonists can be introduced for snakebite management.
 

Background: Familial dysautonomia is a genetic disease in which there is a defect in the autonomic and sensory nervous systems. These systems have a major role in the reproductive system.

Objective: To study the inter-relationship of autonomic and sensory dysfunction and gynecological function.

Methods: The gynecological histories of 48 women with familial dysautonomia were analyzed retrospectively. Their mean age was 22.25 years (range 12-47). Thirty-three women (65%) were available for further questioning and investigation of hormonal status.

Results: Menarche had occurred in 32 of the 48 (66.7%). Their average age of menarche was significantly delayed as compared to their unaffected mothers (15.5 vs. 13.6 years respectively, P=0.002). The most prominent finding was the very high prevalence, 81.2%, of premenstrual symptoms. Seven of 26 had premenstrual syndrome symptoms of dysautonomic crisis. Blood sex hormone levels were normal in 27 of the 33 patients studied. None reached natural menopause. One patient had adenomyosis, and another, dysgerminoma. Three patients became pregnant and delivered healthy infants.

Conclusion: Menarche is delayed in women with FD, and the physiological monthly hormonal fluctuations may disturb autonomic homeostasis sufficiently to precipitate dysautonomic crisis.

Background: Uterine rupture is a catastrophic obstetric complication, most often associated with a preexisting cesarean section scar. Although a vaginal birth after a cesarean is considered safe in modern obstetrics, it is not known whether repeated VBACs increase the risk of rupture, or whether the first VBAC proves the strength and durability of the scar, predicting further successful and less risky vaginal deliveries.

Objectives: To evaluate the effect of repeated vaginal deliveries on the risk of uterine rupture in women who have previously delivered by cesarean section.

Methods: In this retrospective study, 26 VBAC deliveries complicated by uterine rupture were matched for age, parity, and gravidity with 66 controls who achieved VBAC without rupture. The histories, demography, pregnancy, labor and delivery records, as well as neonatal outcome were compared.

Results: We found that the risk of rupture decreases dramatically in subsequent VBACs. Of the 40 cases of uterine rupture recorded during the 18 year study period, 26 occurred during VBAC deliveries. Of these, 21 were complicated first VBACs. We also found that the use of prostaglandin-estradiol, instrumental deliveries, and oxytocin had been used significantly more often during deliveries complicated with rupture than in VBAC controls.

Conclusions: Once a woman has achieved VBAC the risk of rupture falls dramatically. The use of oxytocin, PGE2 and instrumental deliveries are additional risk factors for rupture, therefore caution should be exerted regarding their application in the presence of a uterine scar, particularly in the first vaginal birth after cesarean.

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VBAC= vaginal birth after cesarean section

PGE2= prostaglandin-estradiol

Background: Articular cartilage is incapable of undergoing self-repair since chondrocytes lose their mitotic ability as early as the first year of life. Defects in articular cartilage, especially in weight-bearing joints, will predictably deteriorate toward osteoarthritis.  No method has been found to prevent this deterioration. Drilling of the subchondral bone can lead to fibrocartilage formation and temporary repair that slowly degrades. Animal experiments indicate that introducing proliferating chondrocytes such as cultured articular chondrocytes can reliably reconstruct joint defects.

Objectives: To describe our clinical experience in culturing and transplanting autologous chondrocytes. 

Methods: Biopsies were obtained from 10 patients, aged 18–45, undergoing a routine arthroscopy in which a cartilage defect was identified with indications for cartilage transplantation. The biopsies were further processed to establish chondrocyte cultures. ACT was performed in 8 of the 10 patients because of persistent symptoms for at least 2 months post-arthroscopy. All patients (6 men and 2 women) had a grade IV cartilage defect in the medial or lateral femoral condyle, and three had a defect in the trochlear region as well. Biopsies were removed from the lateral rim of the superior aspect of the femur, and cells were cultured in a clean room. Following a 2 order of magnitude expansion, cells were implanted under a periosteal flap.

Results: The eight patients implanted with autologous cells were followed for 6 months to 5 years (average 1 year). Complaints of giving-way, effusion and joint locking resolved in all patients, and pain as assessed by the visual analogue score was reduced by an average of 50%. Follow-up magnetic resonance imaging studies in all patients revealed that the defects were filled with tissue having similar signal characteristics to cartilage.

Conclusions: Chondrocyte implantation is a procedure capable of restoring normal articular cartilage in cases with isolated joint defects. Pain can be predictably reduced, while joint locking and effusion are eliminated. The effect on osteoarthritis progression in humans has not yet been elucidated.

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ACT = autologous chondrocyte transplantation