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.
Yuksel Cavusoglu, MD, Bulent Gorenek, MD, Bilgin Timuralp, MD, Ahmet Unalir, MD, Necmi Ata, MD and Mehmet Melek, MD
Background: Previous studies have documented that reduction in QT dispersion after thrombolytic treatment in acute myocardial infarction depends on reperfusion status as well as infarct site. Primary percutaneous transluminal coronary angioplasty as compared with thrombolytic therapy has been shown to result in higher patency rates of the infarct vessel.
Objectives: To evaluate whether primary PTCA has a more favorable effect on reducing QT dispersion in patients with acute MI as compared to thrombolytic treatment.
Methods: The study population included 42 consecutive patients (33 men, mean age 58 ± 11 years) with acute Ml (24 anterior wall, 18 inferior wall) who were treated with primary PTCA (group A, n 21) or thrombolytic therapy (group B, n = 21) at 3.9+2 hours after symptom onset. QT intervals were measured before and 24 hours after treatment.
Results: On the admission electrocardiogram, patients with anterior Ml had higher values of QT and QTc dispersions than patients with inferior Ml (52±9 vs. 36±9 msec, R<0.05 and 61+4 vs. 56+4 msec, P=0.002, respectively). There was a significant reduction in QT and QTc dispersions from admission to 24 hours in all patients (from 50+9 to 37+9 msec, P<0.001 and from 59+5 to 42+5 msec, P<0.001. respectively), and also in group A (from 49±8 to 32±5 msec. P<0.001 and from 58+5 to 38+3 msec, P<0.001, respectively) and in group B patients (from 51+10 to 42+10 msec. P<0.01 and from 60±4 to 46±5 msec, P<0.001, respectively). QT and QTc dispersions were found to be shorter in group A at 24 hours after treatment than in group B (32 + 5 vs. 42+10 msec, P<0.001 and 38+3 vs. 46+5 msec, P<0.001. respectively).
Conclusions: Reperfusion therapy with primary PTCA or thrombolytic agents reduces QT and QTc dispersions in acute Ml. QT and QTc dispersions after reperfusion treatment are shorter with primary PTCA than with thrombolytic therapy.
Manfred S. Green, MD, PhD, Gali Aharonowitz, MD, Tamy Shohat, MD, MPH, Rachel Levine, MD, Emilia Anis, MD, MPH and Paul E. Slater, MD, MPH
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.
Ayelet Berg, PhD, Dan Yuval, PhD, Michal Ivancovsky, MBA, Sima Zalcberg, MSc, Avigail Dubani and Jochanan Benbassat, MD
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.
Daniella Rahamin-Cohen, MSc, MB, BS and Yehuda Shoenfeld, MD
Yehuda Edoute, MD, PhD, Yuval Karmon, MD, Ariel Roguin, MD and Haim Ben-Ami, MD