Israel Medical Association Journal

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.

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: Despite years of research and clinical experience with acute appendicitis, the rate of complications in the pediatric age group continues to be high.

Objective: To characterize the profile of the child with appendicitis complicared by perforation or intraabdominal abscess.

Methods: Between 1 January 1985 and 31 December 1997 in our department, 581 children under the age of 14 years were clinically diagnosed as suffering from "acute appendici­tis". The final diagnoses were: white appendix in 28 cases (4.8%), acute non-complicated appendicitis in 472 (81%), and complicated appendicitis in 81 (13.9%), including 51 cases of free perforation (8.7%) and 30 cases of intraabdominal abscess (5.2%). We retrospectively reviewed the charts of all children with complicated appendicitis and those of 70 randomly selected children with non-complicated appendicitis, and compared patient age, gender, weight percentile, past medical history, and course of the illness.

Results: The children with complicated appendicitis were significantly younger (R~4.8*10~⁷), they had higher oral and rectal temperatures (P=7.9*10-⁸), higher platelet count (P=0.0008) and lower hemoglobin level (P=0.004). No difference was found in white blood count (P=0.41). Total delay from symptom onset to surgery was 33 hours (SD 23) in the non-complicated group, 60 hours (SD 38) in the perforated appendicitis group, and 176 hours (SD 107) in the intra­abdominal abscess group (P=4.6*10-⁸). No difference in intra­hospital delay was found.

Conclusions: Children with complicated appendicitis are characterized by younger age, longer delay from symptom onset to correct diagnosis, and typical laboratory findings. Delays in diagnosis can be avoided by first considering the diagnosis of acute appendicitis in the differential diagnosis when examining any child with abdominal pain.

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.

Background: Although influenza is usually a mild self-limiting disease it can cause serious complications in high risk groups. The economic costs of influenza are large due to the burden on the health system and absenteeism from work. There is evidence that the vaccine is underused in groups targeted for vaccination.

Objectives: To estimate: a) the compliance rate with the influenza vaccination in Israel during the winter seasons of 1998/1999 and 1999/2000, b) the role of health care personnel and the media in influencing compliance, and c) the reasons for lack of compliance in the elderly.      

Methods: Two national population-based random telephone surveys of 1,500 households were performed during October 1999 and January 2000 to survey influenza vaccination compliance prior to the winters of 1998/1999 and 1999/2000 respectively. Each survey was performed during four successive evenings. The response rate was 78.1% for the first survey and 79.1% for the second.

Results: Vaccination compliance was similar in both surveys. The average rate of vaccination was 6% for the population under 65 years and 50% for the population of 65 years and above. The overall vaccination rate was around 10%. The family physician was the main authority to recommend the vaccination, followed by the community nurse. Absence of recommendation and lack of faith in the efficacy of the vaccine were the main reasons for non-compliance.

Conclusion: Compliance rates with influenza vaccine in targeted groups in Israel remain relatively low. Health care personnel should be more involved in promoting the vaccine.
 

Background: The outcome of cardiopulmonary arrest in children is poor, with many survivors suffering from severe neurological defects. There are few data on the survival rate following cardiopulmonary arrest in children who arrived at the emergency room without a palpable pulse.

Objective: To determine the survival rate and epidemiology of cardiopulmonary arrest in children who arrived without a palpable pulse at a pediatric ER in southern Israel.

Methods: We retrospectively reviewed the medical records of all patients with cardiopulmonary arrest who arrived at the ER of the Soroka University Medical Center during the period January 1995 to June 1997.

Results: The study group included 35 patients. Resuscitation efforts were attempted on 20, but the remaining 15 showed signs of death and were not resuscitated. None of the patients survived, although one patient survived the resuscitation but succumbed a few hours later. The statistics show that more cardiopulmonary arrests occurred among Bedouins than among Jews (32 vs. 3, P0.0001).

Conclusions: The probability of survival from cardiopulmonary arrest in children who arrive at the emergency room without palpable pulse is extremely low. Bedouin children have a much higher risk of suffering from out-of-hospital cardiopulmonary arrest than Jewish children.

Background: Iatrogenic illness, defined as a disease that results from a diagnostic procedure or from any form of therapy, is a well-recognized phenomenon in clinical practice.

Objectives: To study and evaluate major car-diac iatrogenic disease as the cause of admission to the intensive cardiac care unit in the modern era.

Methods: We assessed 64 critically ill patients suffering from major cardiac iatrogenic problems among a total of 2,559 patients admitted to the intensive cardiac care unit during 3 years. Iatro-genic illness was defined as any problem that resulted from therapy. Only cardiac problems were included in the study. Complications of interventional cardiovascular procedures, suicide attempts or accidental intoxications were ex-cluded.

Results: There was evidence of a major cardiac iatrogenic problem as the cause for admission in 64 patients (2.5%): 58 (91%) suffered from ar-rhythmias (mainly bradyarrhythmias) secondary to beta-blockers, amiodarone, calcium antago-nists, electrolyte imbalance or a combination, and 6 (9%) had non-arrhythmic events (hypotension, syncope or acute heart failure). In 41 patients (64%) the iatrogenic event was considered pre-ventable

Conclusions: Major cardiac iatrogenic compli-cations are an important factor among patients admitted to the intensive cardiac care unit. Most of the events are bradyarrhythmias related to anti-arrhythmic agents. Almost two-thirds of events are preventable.