Israel Medical Association Journal

Background: Spinal dural arteriovenous fistulae comprise the majority of spinal vascular malformations. The most common clinical presentation is that of progressive myelor­adicuiopathy, probably related to venous hypertension, which may lead to permanent disability and even death.

Objective: To report our clinical experience with spinal dural arteriovenous fistulae.

Methods: Nine patients with spinal dural AVF were managed at our center during a one year period (1998-1999). The patients, eight men and one woman ranging in age from 46 to 75 years, presented with initially fluctuating and eventually permanent and progressive paraparesis, sensory disturbances and sphincter dysfunction. The neurological signs generally began symmetrically and progressed from the distal to proximal limb regions. The duration of symptoms before diagnosis ranged from 6 to 36 months during which the patients underwent an extensive but fruitless work-up and even unnecessary operations due to misdiagnosis. All patients finally underwent magnetic resonance imaging and spinal angiography, which demonstrated the pathological vascular fistula. Interruption of the AVF was achieved by embolization or by surgical resection.

Results: Following treatment, six patients experienced improvement of gait and sphincter control, and the severe neurological deficits stabilized in the other three patients with long duration of illness. There was no further deterioration in any of the treated patients.

Conclusions: The history, neurological findings and radiological changes on MRI scan should alert clinicians to the possibility of spinal dural AVF, leading to diagnostic spinal angiography. Early diagnosis and treatment may significantly improve outcome and prevent permanent disability and even mortality.

Background: On 1 January 1995 a new mandatory National Health Insurance Law was enacted in Israel, The new law fostered competition among the four major Israeli healthcare providers (HMO5 or sick funds) already operating in the market due to the possibility that an unlimited number of patients and the relative budget share would shift among the HMOs. This led them to launch advertising campaigns to attract new members.

Objectives: To examine newspaper advertising activities during the early stages of healthcare market reform in Israel.

Methods: Advertising efforts were reviewed during a study period of 24 months (July 1994 to June 1996). Advertisements were analyzed in terms of marketing strategy, costs and quality of information.

Results: During the study period 412 newspaper adver­tisements were collected. The total advertising costs by all HMOs was approximately US$4 million in 1996 prices. Differences were found in marketing strategy, relative adver­tising costs, contents and priorities among the HMOs.

Conclusions: The content of HMO5 newspaper advertis­ing was consistent with their marketing strategy. The mes­sages met the criteria of persuasive advertising in that they cultivated interest in the HMOs but did not provide meaningful information about them. Future developments in this area should include consensus guidelines for advertising activities of HMOs in Israel, instruction concerning the content of messages, and standardization of criteria to report on HMO performance.

Mixed cryoglobulinemia is a systemic vasculitis described as a triad characterized by purpura, weakness and arthralgias. Since the first description of the disease in 1964 by Meltzer and Franklin our understanding of its pathogenesis has increased considerably. The striking association of the disease with hepatitis C virus infection was initially noted in 1990. Since then, the disease has gained growing attention among investigators involved in the study of autoimmune systemic disorders because it represents one of the most intriguing models of autoimmunity triggered by a virus. Nonetheless, a number of answered questions still remain to be resolved and are reviewed in this article.

Background: Between 1970 and 1979, there was an increase in the incidence of viral hepatitis in Israel with a shift of peak incidence to an older age in the Jewish population, followed by a declining trend during the early 1980s. In July 1999 universal immunization of infants against hepatitis A was introduced.

Objective: To evaluate the chan-ges in the epidemiology of viral hepatitis A in Israel during the past decade.

Methods: Viral hepatitis is a notifiable disease in Israel and cases are reported to the regional health offices, which in turn provide summary reports to the Ministry of Health's Department of Epidemiology. The data in this study were derived from the summary reports and from results of seroprevalence studies.

Results: Following the increase in the incidence of reported viral hepatitis (mainly due to type A) between 1970 and 1979, the rates then stabilized and around 1984 began to decline until 1992. Since then there has been a slight increase. Whereas until 1987 the rates were consistently higher in the Jewish population. since then they are higher in the Arab population. The shift in the peak age-specific incidence from the 1-4 to the 5-9 year age group observed in the Jewish population around 1970 occurred 20 years later in the Arab population. The previously described seasonality is no longer evident. Recent seroprevalence studies indicate that by age 18 years only about 30-40% of the Jewish population have anti-hepatitis A antibodies.

Conclusions: The decline in the incidence of hepatitis probably reflects the changing socioeconomic condition occurring at different times in the two major population groups. Since hepatitis A accounts for almost all the acute viral hepatitis in Israel, the universal vaccination of infants introduced in 1999 should substantially lower the morbidity within the next few years.

Background: Patients who feel involved in their treatment have better outcomes than those who do not.

Objective: To identify determinants of perceived patient involvement in obstetric care.

Methods: A retrospective study was undertaken in 1,452 (83%) of 1,750 women sampled in November 1995 from maternity wards of 14 general hospitals in Israel. A postal and telephone survey using a self-administered questionnaire included the following variables: hospital (identity number), patients' age, self-reported complications, previous deliveries, education, ethnicity, and number of obstetric interventions performed and/or considered. The main outcome measured was the reported involvement in decisions for obstetric interventions.

Results: Reported full involvement varied from 72% for epidural analgesia to 13% for forceps/vacuum extraction. Factor analysis identified two dimensions of perceived involvement: one for routine” interventions (enema, monitor­ing, IV line and episiotomy), which are performed in Israel mostly by midwives, and another for "special" interventions (forceps/vacuum extraction, epidural or other analgesia, and cesarian section) performed by physicians. Logistic regression identified hospitals, younger age, number of interventions, and Arab ethnicity as correlates of a perceived non-involvement in decisions for "special" interventions.

Conclusions: Clinical setting, age and ethnicity affected patient perception of involvement in decisions for obstetric interventions.

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: The transfer of therapeutic genes into malignant brain tumors has been the subject of intense pre­clinical and clinical research in recent years. Most approaches have used direct intratumoral placement of a variety of vectors and genes, such as retroviruses or adenoviruses carrying drug-susceptibility genes, modified replication-competent herpes virus, and several vectors carrying tumor suppressor genes such as the p53 gene. However, clinical results have so far been disappointing, mainly due to the limited ability to effectively distribute the genetic material into the target cell population. Accordingly, alternative delivery approaches into the central nervous system, e.g., intravascular, are under investigation. Genetic vectors administered intravascularly are unlikely to penetrate the blood-brain barrier and transfer a gene into brain or tumor parenchyma. However, intravascular delivery of vectors may target endothelial cells lining the blood vessels of the brain. Since endothetial cells participate in a variety of physiological and pathological processes in the brain, their modulation by gene transfer may be used for a variety of therapeutic purposes. Angiogenically stimulated endothelial cells within tumors replicate rapidly and hence may become targets for retroviral-mediated gene transfer.

Objective: To assess the anti-tumor effect of transferring a drug-susceptibility gene into endothelial cells of the tumor vasculature.

Methods: As a model for this approach we delivered concentrated retroviral vectors carrying a drug-susceptibility gene via the internal carotid artery of rats with malignant brain tumors. The safety and efficacy of this approach, without and with subsequent treatment with a pro-drug (ganciclovir). was evaluated.

Results: No acute or long-term toxicity was observed after intraarterial infusion of the vector. Treatment with ganciclovir resulted in variable hemorrhagic necrosis of tumors, indicating preferential transduction of the angiogenically stimulated tumor vasculature. This was accompanied by severe toxicity caused by subarachnoid hemorrhage and intracerebral hemorrhage in vascular territories shared by the tumor and adjacent brain.

Conclusion: The data indicate that endothelial cells can be targeted by intraarterial delivery of retroviral vectors and can be used for devising new gene therapy strategies for the treatment of brain tumors.