Zvi R. Cohen, MD, Revital Duvdevani, PhD, Dvora Nass, MD, Moshe Hadani, MD and Zvi Ram, MD
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.
Donato Alarcon-Segovoia, MD, MS, PhD
The future promises good news for the treatment of systemic lupus erythematosus, some of which can already be foreseen. Increased knowledge on genes that participate in the predisposition, pathogenesis, pharmacogenetics of, and protection against this disease may permit intervention at this level. Also, better understanding about the role of sex hormones has allowed trials of weak androgens or prolactin inhibitors. New immunomodulators or i mmunosuppresors may enable more precise treatment at the immunoregulatory level, and greater knowledge on the disturbance of circuits has already provided hints and even allowed trials of anti-interleukin-10 antibodies, an IL-10 decreasing agent, tolerance-induction strategies or intervention at the level of T cell co-stimulation, as well as immune ablation with subsequent stem cell transplantation. Autoantibodies can be removed, controlled by means of antiidiotypes, which are blocked from reaching their target antigen or uncoupled from the tissues they have reached. All these treatment strategies will gradually become decanted in order to achieve the optimal treatment of SEE, which may turn out to be its cure.
Ma C. Gutierrez-Ruiz, PhD, Luis E. Gomez Quiroz, MSc, Elizabeth Hernandez, MSc, Leticia Bucio, PhD, Veronica Souza, MSc, Luis Llorente, PhD and David Kershenobich, PhD
Background: Inflammatory mediators, including cytokines and reactive oxygen species. are associated with the pathology of chronic liver disease. Hepatocytes are generally considered as targets but not producers of these important mediators.
Objectives: To investigate whether cells of hepatocellular lineage are a potential source of various cytokines we estimated the expression and secretion of tumor necrosis factor alpha, transforming growth factor beta 1 and interleukins I beta, 6 and 8 in the culture of well-differentiated human HepG2 cells treated for 24 hours with ethanol, acetaldehyde and lipopolysaccharide. Lipid peroxidation damage, glutathione content and glutathione peroxidase, catalase and superoxide dismutase activity were also determined.
Methods: HepG2 cells were treated for 24 hours with ethanol (50 mM), acetaldehyde (175 ìM) and LPS (1 ìg/ml). TNF-á, TGF-â, L-1â, IL-6 and IL-8 mRNA were determined by reverse transcriptase polymerase chain reaction and secretion by enzyme-linked immunoassay. Lipid peroxidation damage, glutathione content and antioxidant enzyme activities were determined spectrophotometrically.
Results: Exposure to ethanol for 24 hours induced the expression of TNF-á and TGF- â1. secretion of IL-1â and TGF-â1 and decreased catalase activity. Acetaldehyde markedly increased TNF-á and IL-8 expression, stimulated IL-1â and IL-8 secretion, increased lipid peroxidation damage and decreased catalase activity, while LPS exposure induced the expression of TNF-á. TGF- â1, IL-6 and IL-8, the secretion of TGF-â1, IL-1â, IL-6 and IL-8, and a decrease in catalase activity. No change in GSH, GSHPx or SOD was found in any experimental condition.
Conclusions: The present studies confirm and extend the notion that hepatocytes respond to ethanol, acetaldehyde and LPS-producing cytokines. Oxidative stress produced by the toxic injury plays an important role in this response through upregulation of inflammatory cytokines.
Rafael J. Salin-Pascual, MD, PhD
The novel neuropeptides hypocretin/orexin have recently been located on the lateral hypothalamus cells. This system has been linked to the regulation of both feeding and sleep, and recent studies have found an association between a defect in these neuropeptides and narcolepsy. We conducted a MEDLINE review of all the articles published since the discovery of hypocretin/orexin peptides, narrowing the field to the relationship between these neuropeptides and sleep. The finding of a deletion in the transcription of the hypocretin receptor 2 gene in narcoleptic Doberman pinschers and the development of a knockout of the hypocretin gene in mice pointed to the relevance of this system in the sleep-wake cycle. We provide further evidence of the role of the hypocretin/orexin system in narcolepsy and in sleep regulation and present an integrative model of the pathophysiology of narcolepsy. The discovery of the link between these peptides and narcolepsy opens new avenues to both the understanding of sleep mechanisms and therapeutic implications for sleep disorders.
Shaul Sukenik, MD, Ron Baradin, MD, Shlomi Codish, MD, Lily Neumann, PhD, Daniel Flusser, MD, Mahmoud Abu-Shakra, MD and Dan Buskila, MD
Background: Balneotherapy has been successfully used to treat various rheumatic diseases, but has only recently been evaluated for the treatment of fibromyalgia. Since no effective treatment exists for this common rheumatic disease, complementary methods of treatment have been attempted.
Objectives:To assess the effectiveness of batneotherapy at the Dead Sea area in the treatment of patients suffering from both fibromyalgia and psoriatic arthritis.
Methods: Twenty-eight patients with psoriatic arthritis and fibromyalgia were treated with various modalities of batneotherapy at the Dead Sea area. Clinical indices assessed were duration of morning stiffness, number of active joints, a point count of 18 fibrositic tender points, and determination of the threshold of tenderness in nine fibrositic and in four control points using a dolorimeter.
Results: The number of active joints was reduced from 18.4+10.9 to 9+8.2 (P< 0.001). The number of tender points was reduced from 12.6+2 to 7.1±5 in men (P<0.003) and from 13.1+2 to 7.5+3.7 in women (P<0.001). A significant improvement was found in dolorimetric threshold readings after the treatment period in women (P< 0.001). No correlation was observed between the reduction in the number of active joints and the reduction in the number of tender points in the same patients (r= 0.2).
Conclusions: Balneotherapy at the Dead Sea area appears to produce a statistically significant substantial improvement in the number of active joints and tender points in both male and female patients with fibromyalgia and psoriatic arthritis. Further research is needed to elucidate the distinction between the benefits of staying at the Dead Sea area without balneotherapy and the effects of balneotherapy in the study population.
Joram Wardi, MD, Ram Reifen, MD, Hussein Aeed, PhD, Liliana Zadel, MD, Yona Avni, MD and Rafael Bruck, MD
Objective: To study whether retinolpalmitate, beta-carotene or lycopene could prevent liver cirrhosis induced by thioacetamide in rats.
Methods: In the control group liver cirrhosis was induced in male Wistar rats by intraperitoneal injections of TAA 200 mg/ kg for 12 weeks. The three study groups received in addition to TM either beta-carotene, lycopene or retinolpalmitate by gavage through an orogastric tube. Histopathological analysis and determination of the hydroxyproline contents of the livers were performed at the end of the protocol.
Results: Rats treated with beta-carotene and TAA had lower histopathologic scores and reduced levels of hepatic hydroxyproline (P= 0.02) than those treated by TAA alone. A trend of decreased fibrosis was observed in the rats treated with lycopene and TAA although this lacked statistical significance.
Conclusions: Beta-carotene attenuated liver cirrhosis induced by TAA in rats. The mechanism may be related to effects on hepatic stellate cells or to scavenging of free radicals by beta-carotene. Retinolpalmitate and lycopen had no significant beneficial effect.