Israel Medical Association Journal

Since both major forms of diabetes involve inadequate function of pancreatic beta cells, intensive research is ongoing to better understand how beta cells perform their complex role of secreting the hormone insulin in response to physiologic needs. Identification and characterization of pancreatic transcription factors has revealed that they play a crucial role not only in maintenance of mature beta-cell function but also at multiple stages in pancreatic development. Furthermore, recent reports have revealed their potential to convert non-beta cells into insulin-producing cells, which in some cases can function to ameliorate diabetes in experimental animals. The ability to translate these successes to the clinic will require a detailed mechanistic understanding of the molecular basis of action of these proteins. Specific gene regulation in beta cells involves the action of multiple transcription factors recruited to the promoter and functioning synergistically to activate transcription, in part through recruitment of co-activator proteins and components of the basal transcriptional machinery. In addition, the process involves modification of chromatin structure, the details of which are beginning to be elucidated. Our ability to modulate gene expression patterns may lead to developing ways to provide an unlimited supply of functional beta cells for transplantation, permitting a dramatic improvement in therapeutic options for diabetes.

Type 1 diabetes mellitus is caused by an autoimmune destruction of pancreatic islet beta cells, leading to insulin deficiency. Beta-cell replacement is considered the optimal treatment for type 1 diabetes, however it is severely limited by the shortage of human organ donors. An effective cell replacement strategy depends on the development of an abundant supply of beta cells and their protection from recurring immune destruction. Stem/progenitor cells, which can be expanded in tissue culture and induced to differentiate into multiple cell types, represent an attractive source for generation of cells with beta-cell properties: insulin biosynthesis, storage, and regulated secretion in response to physiologic signals. Embryonic stem cells have been shown to spontaneously differentiate into insulin-producing cells at a low frequency, and this capacity could be further enhanced by tissue culture conditions, soluble agents, and expression of dominant transcription factor genes. Progenitor cells from fetal and adult tissues, such as liver and bone marrow, have also been shown capable of differentiation towards the beta-cell phenotype in vivo, or following expression of dominant transcription factors in vitro. These approaches offer novel ways for generation of cells for transplantation into patients with type 1 diabetes.

Background: The management of diabetes in preschool children poses unique difficulties for both the families and the medical team.

Objective: To test the feasibility and safety of insulin pump therapy in the 1–6 year age group in order to improve quality of life and metabolic control.

Methods: The study group comprised 15 type 1 diabetic children aged 1–6 years old (mean ± SD, 3.8 ± 1.2 years) from three diabetes centers. Insulin pump therapy was applied for 12 months. Data, including insulin dose, hemoglobin A1c, hypoglycemic events, as well as scores on the Diabetes Quality of Life Measure Questionnaire and the Diabetes Treatment Satisfaction Questionnaire, were collected and compared with the multiple daily injections treatment prior to entry into the study.

Results: HbA1c[1] was measured at the beginning of the study and at 2, 4, 8 and 12 months later; the respective levels (mean ± SD) were 8.82 ± 0.98, 8.45 ± 1.05, 8.37 ± 0.85, 8.32 ± 0.71, 8.18 ± 0.90%. HbA1c measurements after 12 months were significantly lower than at the beginning of the study (P < 0.05). There were no significant differences in insulin dose and the total number of hypoglycemic events. In both the DQOL[2] and DTSQ[3] scales there were significant differences in scores in favor of the insulin pump period (43.7 ± 8.0 versus 33.7 ± 7.9, P < 0.001; and 10.9 ± 2.3 versus 14.5 ± 2.3, P < 0.001), respectively.

Conclusions: For very young diabetic children, insulin pump therapy improves quality of life and is feasible and safe. It should be considered as an optional mode of therapy for this age group.

Background: Idiopathic left ventricular tachycardia with a right bundle branch block configuration and left axis deviation, first described by Belhassen et al., is a rare electrocardiographic-electrophysiologic entity. Radiofrequency catheter ablation has been proposed as a good therapeutic option, but the best criteria for determining the optimal site of ablation are still under debate.

Objectives: To report the clinical features, electrophysiologic characteristics, results of RFA[1], and long-term outcome in 18 patients with "Belhassen's VT” treated in our laboratory during the last 10 years, stressing the best electrophysiologic criteria for determining the optimal site of ablation.

Methods: Eighteen consecutive patients with this specific VT[2] underwent RFA in our laboratory during the last 10 years. RFA was acutely successful in 17 patients after one or two procedures (15 and 2 patients, respectively) using 4.1 ± 2.2 RF pulses. The putative ablation sites were defined by good pace-mapping (3 patients), earliest recorded Purkinje spike prior to the QRS onset during VT or sinus rhythm (6 patients), earliest endocardial activation during VT (1 patient), and diastolic potential preceding the Purkinje spike during VT and/or late diastolic potential in sinus rhythm (7 patients). In the patients with a definite successful ablation, the ratio of successful to unsuccessful radiofrequency pulse delivery to the diastolic potential site was compared to that of other methods. The ratio of successful RFA at the diastolic potential site (5:8) was higher than in the other methods (8:31), and the difference was statistically significant (P = 0.05). Successful ablation sites were more basal when the diastolic potential site was chosen.

Conclusion: The results of the present study confirm the high success rate and safety of RFA using conventional techniques in the management of “Belhassen VT,” suggesting that this procedure can be proposed as a first-line therapy. Ablating at a site demonstrating a late diastolic potential is at least as effective as ablating at a ventricular exit site, although the use of combined electrophysiologic criteria may be the optimal approach.

Background: Pseudomembranous colitis is a well-recognized cause of diarrhea in patients receiving antibiotics and has significant consequences in terms of morbidity, mortality and cost. Clostridium difficile infection is the single most important infectious cause of PMC[1]. PMC is frequently nosocomial, with an increased risk of spread among institutionalized patients, both in hospitals and nursing homes.

Objective: To investigate the demographic, clinical and laboratory characteristics of PMC patients in an Israeli elderly population.

Methods: We studied 72 hospitalized patients with endoscopically proven PMC. The medical records of all patients including clinical history and laboratory data were reviewed, such as: age, pre-hospitalization status (dependency or not, in the community as compared to the nursing home), background medical history, presenting symptoms, antibiotic history, physical examination on admission, hematologic and biochemical parameters, treatment, duration of hospitalization, complications, mortality and recurrence of disease.

Results: Of the 72 patients (34 males and 38 females, mean age 77 years) 47% were nursing home residents. Pre-hospitalization antibiotic treatment was given to 91.4% for infections of the upper respiratory tract (45%) and urinary tract (45%). The most common antibiotics were cephalosporin (64%), penicillins (42%) and quinolones (28%). Sixty-four percent of the patients were treated with more than one antibiotic, 26% of patients received anti-acid therapy and 36% had been fed with a nasogastric tube. On admission, leukocytosis was found in 79% of patients, >20,000/mm³ in half of them; 60% were anemic, 60% had elevated erythrocyte sedimentation rate, and 78% had hypoalbuminemia. Treatment consisted of metronidazole (41%) or a combination of metronidazole and vancomycin (56%). Overall, 31% of patients recovered without complications, 29% died within 30 days of hospitalization, and 24% were re-hospitalized due to recurrence of PMC.

Conclusion: The most common antibiotics implicated in PMC are cephalosporin, penicillins and quinolones. The disease is associated with high mortality and recurrence rates.