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עמוד בית
Sat, 18.05.24

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May 2001
Aaron Ciechanover, MD, DSc

Between the 1960s and 1980s, the main focus of biological research was nucleic acids and the translation of the coded information into proteins. Protein degradation was a neglected area and regarded by many as a scavenger, non-specific and end process. While it was known that proteins are turning over, the large extent and high specificity of the process - where distinct proteins have half-lives that range from a few minutes to several days - have not been appreciated. The discovery of the lysosome by Dr. Christian de Duve did not change this view significantly, as this organelle is involved mostly in the degradation of extra- and not intracellular proteins, and it was clear that lysosomal proteases, similar to those of the gastrointestinal tract, cannot be substrate specific. The discovery of the complex cascade of the ubiquitin pathway has changed this view dramatically. It is now clear that degradation of cellular proteins is a highly complex, temporally controlled, and tightly regulated process that plays major roles in a broad array of basic pathways during cell life and death. With the multitude of substrates targeted and processes involved, it is not surprising that aberrations in the pathway have been recently implicated in the pathogenesis of many diseases, certain malignancies and neurodegeneration among them. Degradation of a protein via the ubiquitin pathway involves two successive steps: a) conjugation of multiple ubiquitin moieties to the substrate, and b) degradation of the tagged protein by the downstream 263 proteasome complex with release of free and re-utilizable ubiquitin. Despite intensive research, the unknown still exceeds what we currently know on intracellular protein degradation and major key problems remain unsolved. Among these are the modes of specific and timed recognition of the myriad substrates of the system and the nature of the mechanisms that underlie aberrations in the system and pathogenesis of diseases.

March 2001
Benjamin Avidan, MD, Ehud Melzer, MD, Nathan Keller, MD and Simon Bar-meir, MD

Background: Current treatment for the eradication of Helicobacter pylori in patients with peptic disease is based on the combination of antibiotic and anti-acid regimens. Multiple combinations have been investigated, however no consensus has been reached regarding the optimal duration and medica­tions.

Objectives: To assess the efficacy of two treatment regimens in patients with peptic ulcer disease and non-ulcer dyspepsia, and to determine the need for gastric mucosal culture in patients failing previous treatment.

Methods: Ninety patients with established peptic ulcer and NUD (with previously proven ulcer) were randomly assigned to receive either bismuth-subcitrate, amoxycillin and metrnida­zole (8AM) or lansoprasole, clarithromycine and metronida­zole (LCM) for 7 days. Patients with active peptic disease were treated with ranitidine 300 mg/day for an additional month.

Results: Eradication failed in 8 of the 42 patients in the 8AM group and in 2 of the 43 patients in the LCM group, as determined by the 13C urea breath test or rapid urease test (19% vs. 5%, respectively, P=0.05). Five of these 10 patients were randomly assigned to treatment with lansoprazole, amoxycillin and clarithromycin (LAC) regardless of the culture obtained, and the other 5 patients were assigned to treatment with lansoprazole and two antibacterial agents chosen according to a susceptibility test. Eradication of H. pylon was confirmed by the ‘3C urea breath test. The same protocol (LAC) was used in all patients in the first group and in four of the five patients in the second group. The culture results did not influence the treatment protocol employed.

Conclusions: Combination therapy based on proton pump inhibitor and two antibiotics is superior to bismuth-based therapy for one week. Gastric-mucosal culture testing for sensitivity of H. pylon to antibiotics is probably unnecessary before the initiation of therapy for patients with eradication failure.

Boaz Amichai, MD, Marcelo H. Grunwald, MD and Lesley Brenner, BSc
Boaz Amichai, MD, Marcelo H. Grunwald, MD and Lesley Brenner, BSc

Cancer is a multi-step disease involving a series of genetic alterations that result in the loss of control of cell proliferation and differentiation. Such genetic alterations could emerge from the activation of oncogenes and the loss or malfunctioning of tumor suppressor gene activity. Our understanding of cancer has greatly increased through the use of DNA tumor viruses and their transforming proteins as a biological tool to decipher a cascade of events that lead to deregulation of cell proliferation and subsequent tumor formation. For the past ten years our laboratory has focused on the molecular biology of the human neurotropic papovavirus, JCV. This virus causes progressive multifocal Ieukoencephalopathy, a fatal neuro­degenerative disease of the central nervous system in immunocompromised patients. JCV is a common human virus that infects more than 80% of humans but does not induce any obvious clinical symptoms. The increased incidence of acquired immune deficiency syndrome and the use of immunosuppressive chemotherapy have dramatically raised the incidence of PML. The coincidental occurrence of malignant astrocytes and oligodendrocytes in PML patients, coupled with the induction of glioblastoma in JCV-intected non­human primates, provides intriguing speculation on the association between JCV and CNS malignancies. In this report we discuss clinical data and laboratory observations pointing to the direct involvement of JCV in cancer.

February 2001
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.

January 2001
Matityahu Lifshitz MD, Vladimir Gavrilov MD, Aharon Galil MD and Daniella Landau MD

Background: Narcotic abuse has steadily become more prevalent in Israel and may result in an increasing number of children exposed prenatally to narcotics, with a consequent increase in the number of infants born with neonatal abstinence syndrome.

Objective: To report our experience with infants born to narcotic-addicted women between the years 1995 and 1998 at the Soroka University Medical Center.

Methods: The medical records of 24 newborns and their drug-addicted mothers admitted to our Medical Center for parturition were analyzed retrospectively. A diagnosis of NAS was established on the basis of the clinical presentation and anamnesis. The Finnegan Neonatal Abstinence Scoring System was used to assess drug withdrawal. Urine toxicological analysis for narcotics was done only for year 1998.

Results: Of the 24 newborn infants exposed prenatally to narcotics 23 (96%) developed NAS, and 78% (18 of the 23) had a Finnegan score of 8 or more. These 18 infants were treated pharmacologically (tincture of opium and/or Phenobarbital) until the score was reduced to less than 8, after which they received supportive treatment. In one child who became lethargic after the first dose of tincture of opium, the medication was stopped and supportive treatment alone was given. Four of the five neonates with scores of 7 and less were given supportive treatment. One of five infants who had a low Finnegan score at birth nevertheless received pharmacological therapy to prevent further deterioration of his physical state since he was born with severe dyspnea. Ten of the 24 children (42%) were followed for lengths of time ranging from 6 to 22 months after discharge, all of whom showed normal development.

Conclusion: About three-quarters of newborns exhibiting withdrawal syndrome required pharmacological therapy. Previous information on maternal drug abuse is a crucial criterion for early detection and treatment.
 

Robert Slater, DPM Yoram Ramot, MD and Micha Rapoport, MD
Paul E. Slater, MD, MPH, Alex Leventhal, MD, MPH, MPA and Emilia Anis, MD, MPH
December 2000
Menachem Moshkowitz, MD, Shlomo Brill, MD, Fred M. Konikoff, MD, Mordechai Averbuch, MD, Nadir Arber, MD and Zamir Halpern, MD
 Background: Cigarette smoking has long beenregarded as an important factor in the pathogenesis of peptic ulcer disease.

Objective: To investigate whether cigarette smoking has an additive effect on the clinical presentation and course of disease in Helicobacter pylori-positive dyspeptic patients.

Patients and Methods: The study group comprised 596 consecutive H. pylori-positive dyspeptic patients (334 males and 262 females, mean age 50.6, range 12--81 years). Following upper gastrointestinal endoscopy, patients were subdivided by diagnosis as follows: Non-ulcer patient group (n=312: gastritis 193, duodenitis 119), gastric ulcer (n=19), and duodenal ulcer (n=265). H. pylori infection was confirmed by histology and/or rapid urease test. In addition, 244 patients had a positive 14C-urea breath test prior to antimicrobial treatment. The patients' medical history and smoking habits were obtained using a detailed questionnaire completed by the patients and their referring physicians.

Results: There were 337 non-smoking patients, 148 current smokers and 111 past smokers. Gastric and duodenal ulcers were significantly less prevalent in non-smokers than in current or past smokers (gastric 1.8%, 4.1%, 6.3%; duodenal 39.8%, 50%, 51.4%, respectively) (P0.05). The incidence of gastrointestinal bleeding was significantly lower in non-smokers than in current or past smokers (7.1%, 8.1% and 20.7%, respectively) (P0.05). Bacterial density, as assessed by the UBT value in 244 patients, was higher in non-smokers (mean 352.3273 units) than in past smokers (mean 320.8199) or current-smokers (mean 229.9162) (P0.05). Logistic regression analysis revealed that male gender, current smoking, and immigration from developing countries were all significant independent risks for developing duodenal ulcer, while only past smoking was associated with a higher rate of upper gastrointestinal bleeding in the past.

Conclusions: In H. pylori-positive dyspeptic patients, current smoking as well as male gender and immigration from developing countries are associated with an increased risk for duodenal ulcer. This effect does not seem to be related to the bacterial density or increased urease activity of H. pylori organisms.

Nurith Hiller, MD, Daniel Berelowitz, MD and Irith Hadas-Halpern, MD
 Background: Primary epiploic appendagitis is a relatively rare condition in which torsion and inflammation of an epiploic appendix result in localized abdominal pain. This is a non-surgical situation that clinically mimics other conditions requiring surgery such as acute diverticulitis or appendicitis.

Objective: To investigate the clinical, laboratory and radiological findings of the disease.

Methods: During the years 1995-88 five patients with primary epiploic appendigitis were diagnosed at our institution. The clinical, laboratory and imaging results were summarized and compared to previously reported series. Emphasis was placed on the computed tomography findings, which are the gold standard for diagnosis.

Results: All our patients (two males and three females, mean age 47 years) presented with left lower quadrant abdominal pain. CT proved to be the imaging modality of choice in all patients by showing a pericolic fatty mass with an increased attenuation as compared to normal abdominal fat. In all cases the mass was surrounded by a high attenuation rim, and focal stranding of the fat was observed. In no case was there thickening of the adjacent bowel wall. This serves as an important, and previously unreported, clue for diagnosis.

Conclusion: Primary epiploic appendagitis is a relatively rare condition that may be clinically misdiagnosed, resulting in unnecessary surgical intervention. Judicious interpretation of CT may lead to early diagnosis and ensure proper conservative treatment.

Rita Rachmani, MD, Zohar Levi, MD, Rika Zissin, MD, Merav Lidar, MD and Mordechai Ravid, MD, FACP
November 2000
Oded Szold MD, Avi A. Weinbroum MD, Ron Ben-Abraham MD, Talma E. Englender MD, Dror Ovadia MD and Patrick Sorkine MD

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.
 

September 2000
Hana Strul MD and Nadir Arber MD

There is increasing evidence to suggest that aspirin and other non-steroidal anti-inflammatory drugs reduce the risk of colorectal cancer. This observation is supported by animal studies that show fewer tumors per animal and fewer animals with tumors after administration of several different NSAIDs. Intervention data in familial adenomatous polyposis have established that the effect is exerted on the process of human colonic adenoma formation. Supportive evidence in sporadic colorectal neoplasia, derived from 22 of 24 studies (both case-control and cohort), found a reduced risk in men and women for cancers of the colon and the rectum and for both aspirin and the other NSAIDs. Earlier detection of lesions as a result of drug-induced bleeding does not seem to account for these findings. Although the molecular mechanism responsible for the chemopreventive action of this class of drugs is not yet completely understood, the protection may affect several pathways including both cell cycle arrest and induction of apoptosis.

In the third millennium the question is not if but how. Based on the consistency of epidemiological, clinical and experimental data, the association between regular long-term aspirin or NSAIDs intake and a decreased death rate from colorectal cancer is sound and there is no need for further placebo trials. At the same time, despite this consistency there is no clear data on the dose, duration or frequency of use for cancer-preventive activity.

Aliza Zeidman, MD, Benjamin Z. Sender, MD, Jumah Badear, MD and Zinaida Fradin, MD
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