Ubiquitin-proteasome degradation is a key cellular process involved in almost every aspect of cell life. According to the current concept, proteins are stable unless they are marked by poly-ubiquitination for degradation by the 26S proteasomes. A new twist in the concept became evident while studying the degradation of the tumor suppressor p53, a protein that appeared to satisfy this principle. We have discovered that native p53 is also prone to ubiquitin-independent 20S proteasomal degradation, suggesting that certain proteins are inherently unstable. We further found that this process of degradation is mediated by 20S proteasomes and inhibited by NADH quinone oxidoreductase 1. Our recent findings together with previous observations of ubiquitin-independent degradation suggest the existence of ubiquitin-independent mechanisms for proteasomal protein degradation in the cells.

Polyubiquitylation of cellular proteins has long been recognized as a prelude to a degradative fate in proteasomes. In recent years, however, ubiquitin conjugation has emerged as a regulatory strategy of considerable versatility. Most notably, monoubiquitylation is attributed an intimate role in trafficking of membrane proteins between various cellular compartments. Diverse classes of transmembrane proteins from across the eukaryotic spectrum (e.g., epidermal growth factor-receptor and other receptor tyrosine kinases) become modified with monoubiquitin molecules. Monoubiquitylation of substrates, in turn, regulates both their endocytosis at the plasma membrane and sorting in endosomes for delivery to lysosomes or vacuoles. A mechanistic rationale lies in the identification of a growing list of ubiquitin-binding domains carried by a variety of endocytic adaptor proteins. Thus, ubiquitin-conjugated membrane proteins may form extensive contacts with the endocytic machinery. Further, ubiquitin-binding adaptors and other endocytic components are, likewise, often monoubiquitylated. In this case, ubiquitin conjugation may serve to enhance intermolecular avidity in cargo-bound endocytic complexes, or alternatively, to mediate timely inactivation of ubiquitin-binding adaptors. Interestingly, the ubiquitin/endocytosis interface is appropriated by pathogenic organisms, for instance, during budding of viruses from host-infected cells. Moreover, compromised ubiquitin-mediated transport of certain signaling receptors is associated with disease states, including oncogenic transformation.

The Ink4a-Arf locus, which encodes two distinct tumor suppressor proteins, is inactivated in many cancers. Whereas p16^Ink4a is an inhibitor of cyclin D-dependent kinases, p19^Arf (p14^ARF in humans) antagonizes the E3 ubiquitin protein ligase activity of Mdm2 to activate p53. We now recognize that Arf functions in both p53-dependent and -independent modes to counteract hyper-proliferative signals originating from proto-oncogene activation, but its p53-independent activities remain poorly understood. Arf proteins are highly basic (> 20% arginine content, pI > 12) and predominantly localize within nucleoli in physical association with an abundant acidic protein, nucleophosmin (NPM/B23). When bound to NPM[1], Arf proteins are relatively stable with half-lives of 6–8 hours. Although mouse p19^Arf contains only a single lysine residue and human p14^ARF has none, both proteins are N-terminally ubiquitinated and degraded in proteasomes. Through as yet uncharacterized mechanisms, p19^Arf induces p53-independent sumoylation of a variety of cellular target proteins with which it interacts, including both Mdm2 and NPM. A naturally occurring NPM mutant (NPMc) expressed in myeloid leukemia cells redirects both wild-type NPM and p19^Arf to the cytoplasm, inhibits Arf-induced sumoylation, and attenuates p53 activity. Thus, ubiquitination and sumoylation can each influence Arf tumor suppressor activity.

Background: Virtual reality immersion has been advocated as a new effective adjunct to drugs for pain control. The attenuation of pain perception and unpleasantness has been attributed to the patient's attention being diverted from the real, external environment through immersion in a virtual environment transmitted by an interactive 3-D software computer program via a VR[1] helmet.

Objectives: To investigate whether VR immersion can extend the amount of time subjects can tolerate ischemic tourniquet pain.

Methods: The study group comprised 20 healthy adult volunteers. The pain was induced by an inflated blood pressure cuff during two separate, counterbalanced, randomized experimental conditions for each subject: one with VR and the control without VR exposure. The VR equipment consisted of a standard computer, a lightweight helmet and an interactive software game.

Results: Tolerance time to ischemia was significantly longer for VR conditions than for those without (P < 0.001). Visual Analogue Scale (0–10) ratings were recorded for pain intensity, pain unpleasantness, and the time thought about pain. Affective distress ratings of unpleasantness and of time thought about pain were significantly lower during VR as compared with the control condition (P < 0.003 and 0.001 respectively).

Conclusions: The VR method in pain control was shown to be beneficial. The relatively inexpensive equipment will facilitate the use of VR immersion in clinical situations. Future research is necessary to establish the optimal selection of clinical patients appropriate for VR pain therapy and the type of software required according to age, gender, personality, and cultural factors.

Background: Physicians in the community work on a tight and often pressured schedule; verbal and non-verbal techniques to terminate the patient-physician encounter are therefore necessary.

Objectives: To characterize ways of terminating the encounter.

Methods: Using a structured questionnaire we observed seven family physicians and nine consultants and recorded patient-physician encounters to assess techniques for terminating the encounter.

Results: In all, 320 encounters were recorded, 179 (55.9%) by consultants and 141 (44.1%) by family physicians. The mean duration of the encounters was 9.02 ± 5.34 minutes. The mean duration of encounters with family physicians was longer than consultants (10.39 vs. 7.93 minutes, P < 0.001). In most cases the encounter ended with the patient receiving printed documentation from the physician (no difference between family physicians and consultants). Consultants were more likely to end the encounter with a positive concluding remark such as “feel good” or “be well” (P < 0.01). There was no single occasion where termination of the encounter was initiated by the patient.

Conclusions: Giving a printed document to the patient appears to be perceived by both patients and physicians as an accepted way to end an encounter. Another good way to end the encounter is a positive greeting such as “feel good” or “be well.”
 

Background: Debate continues in Israel as to whether to allow patients in public hospitals to choose their physician in return for an additional, out-of-pocket payment. One argument against this arrangement is that the most senior physicians will devote most of their time to private patients and not be sufficiently available to public patients with complex cases.

Objectives: To analyze the patterns of surgical seniority in Jerusalem hospitals from a number of perspectives, including the extent to which: a) opting for private care increases the likelihood of being treated by a very senior surgeon; b) public patients undergoing complex operations are being treated by very senior surgeons, c) the most senior surgeons allocate a significant portion of their time to private patients.

Methods: Demographic and clinical data were retrieved from the operating room records of three of the public hospitals in Jerusalem for all 38,840 operations performed in 2001. Of them, roughly 6000 operations (16%) were performed privately. Operations were classified as "most complex," "moderately complex" and "least complex" by averaging the independent ratings of eight medical and surgical experts. The surgeon's seniority was graded as "tenured" (tenured board-certified specialists, including department heads), "senior" (non-tenured board-certified specialists), and "residents." For each operation, we considered the seniority of the lead surgeon and of the most senior surgeon on the surgical team.

Results: The lead surgeon was of tenured rank in 99% of the most complex private cases and 74% of the most complex public cases, in 93% of the moderately complex private and 35% of the moderately complex public cases, and in 92% of the least complex private and 32% of the least complex public cases. The surgical team included a tenured physician in 97%, 66%, and 53% of the most complex, moderately complex, and least complex public operations, respectively. In both private and public cases, a board-certified (tenured or senior) specialist was a member of the surgical team for almost all of the most complex and moderately complex operations. On average, over half of the operations in which the lead surgeon was a department head were performed on public patients. Among tenured surgeons, those who spent more hours than their colleagues leading private operations also tended, on average, to spend more hours leading public operations.

Conclusions: Private patients have an advantage over public patients in terms of the seniority of the lead surgeon. However, there is also substantial involvement of very senior surgeons in the treatment of public patients, particularly in those cases that are most complex. 

Background: Peritoneal dialysis is a widely accepted route for renal replacement. With the advent of endoscopy, many surgical techniques for the prevention of catheter failure have been proposed.

Objectives: To evaluate the outcomes of patients undergoing laparoscopic Tenckhoff catheter implantation, using the pelvic fixation technique.

Methods: Data analysis was retrospective. All procedures were performed under general anesthesia. A double-cuffed catheter was inserted using two 5 mm trocars and one 10 mm trocar, fixing its internal tip to the dome of the bladder and its inner cuff to the fascia. Catheter failure was defined as persistent peritonitis/exit-site/tunnel infection, severe dialysate leak, migration or outflow obstruction.

Results: LTCI[1] was performed in 34 patients. Mean patient age was 65 ± 17 years. In 12 of the 34 patients the indication for LTCI was end-stage renal failure combined with NYHA class IV congestive heart failure. Operative time was 35 ± 15 minutes. A previous laparotomy was performed in 9 patients. Hospital stay was 1.5 ± 0.6 days. The first continuous ambulatory peritoneal dialysis was performed after 20 ± 12 days. Median follow-up time was 13 months. There were several complications, including 5 (14%) exit-site/tunnel infections, 27 episodes (0.05 per patient-month) of bacterial peritonitis, 3 (9%) incisional hernias, 1 case of fatal intraabdominal bleeding, 2 (5.8%) catheter migrations (functionally significant), and 10 (30%) cases of catheter plugging, 8 of which were treated successfully by instillation of urokinase and 2 surgically. A complication-mandated surgery was performed in 8 patients (23.5%). The 1 year failure-free rate of the catheter was 80.8%. One fatal intraabdominal bleeding was recorded.
Conclusions: LTCI is safe, obviating the need for laparotomy in high risk patients. Catheter fixation to the bladder may prevent common mechanical failures

Three decades have elapsed since the inception of Level I trauma centers as the final link in the trauma system "chain of survival".

Orbital dog bites, although uncommon, occur mostly in children and are reported to be associated with severe ocular adnexal injury without globe involvement.

Background: Advanced glycation end products, formed by the non-enzymatic glycation of proteins with reducing sugars, are thought to play a pathogenetic role in the vascular complications of diabetes, uremia and atherosclerosis. β2-microglobulin is a major constituent of amyloid fibrils in dialysis-related amyloidosis. AGE[1]-modified β2m[2] has been found in amyloid deposits of long-term hemodialysis patients. AGE-modified β2m has also been shown to enhance chemotaxis and increase tumor necrosis factor-alpha and interleukin-1 beta secretion by circulating and tissue monocytes/macrophages.

Objectives: To investigate the effect of AGE-modified β2m and AGE-human serum albumin on TNF-α[3] and IL-1β[4] secretion by human peritoneal macrophages derived from patients on continuous ambulatory peritoneal dialysis.

Methods: Human PMØ[5] were isolated from peritoneal dialysis effluent of stable CAPD[6] patients and were incubated for 24 hours with AGE-modified β2m, β2m, AGE-HSA[7], HSA or lipopolysaccharide. TNF-α or IL-1β secretion was measured by enzyme-linked immunosorbent assay in cell-free culture supernatants.

Results: Both AGE-modified β2m and AGE-HSA significantly increased TNF-α and IL-1β secretion by human PMØ in a dose-dependent manner (50–200 μg/ml). In contrast, β2m or HSA had no such stimulatory effect on TNF-α secretion but had a small significant increase in IL-1β secretion.

Conclusions: AGE-modified β2m promotes in vitro TNF-α and IL-1β secretion by human PMØ of CAPD patients. Activation of these macrophages by AGE-modified β2m may be a contributory factor to the morphologic changes and altered permeability of the peritoneal membrane in long-term CAPD. 

Objectives: To determine the effectiveness of a neuroreflexology-based screening test, specifically the Medex device (Medex Screen Ltd.), for diagnosing patients undergoing conventional internal organ assessment, in a hospital setting.

Methods: Patients admitted to an internal medicine department, who met the inclusion criteria and agreed to participate, underwent conventional medical evaluation that included past medical history and physical examination. Another examination was conducted by a second physician using the Medex device to determine internal organ pathologies. A third researcher compared the actual “conventional” diagnosis with the Medex device output using standard statistical analysis.   

Results: Overall, 150 patients participated in the study. Correlation was significant for all categories (P < 0.01) except for blood and lymphatic disease. A high sensitivity (>70%) was measured for cardiovascular, respiratory, gastrointestinal and genitourinary diseases. The highest measure of agreement, as represented by the Cohen-Kappa factor, was found for respiratory disease (0.57).

Conclusions: Although the exact mechanism is not entirely clear, measurement of electroskin impedance of dermal-visceral zones has the potential to serve as a screening tool for inner organ pathologies. Further research should be conducted to create more evidence to support or dispute the use of this technique as a reliable diagnostic tool.