Israel Medical Association Journal

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: Hyperhomocysteinemia is a well-recognized risk factor for accelerated atherosclerosis in hemodialysis patients.

Objectives: To examine the effects of two doses of vitamins B6 and B12 and folic acid on homocysteine levels in hemodialysis patients and assess the functional impact of the methylenetetrahydrofolate reductase genotype on the response to treatment.

Methods: In a randomized prospective study, we assessed the effects of folic acid and two doses of B-vitamins in 50 hemodialysis patients with hyperhomocysteinemia. Patients were divided into two groups: 26 patients (group A) who received 25 mg of vitamin B₆ daily and one monthly injection of 200 µg vitamin B12, and 24 patients (group B) who received 100 mg of vitamin B6 daily and one monthly injection of 1,000 µg vitamin B12. In addition, both groups received 15 mg folic acid daily. Patients were evaluated for homocysteine levels as well as for coagulation and a thorough lipid profile. Baseline Hcy[1] levels were determined after at least 4 weeks washout from all folic acid and B-vitamins that were given. MFTHR[2] alleles were analyzed, as were activated protein C resistance, von Willebrand factor and lupus anticoagulant.

Results: Basal plasma Hcy levels were significantly elevated in hemodialysis patients compared with normal subjects (33.8 ± 4.3 vs. 4.5 to 14.0 mmol/L). Following treatment, Hcy levels were significantly reduced to 21.2 ± 1.6 in group A and 18.6 ± 1.4 mmol/L in group B (P < 0.01). There was no difference in Hcy reduction following the administration of either high or low dosage of vitamins B6 and B12 utilized in the present study. There was no correlation between Hcy levels or thrombophilia and high incidence of thrombotic episodes in hemodialysis patients. Genotypic evaluation of MTHFR revealed that the presence of homozygous thermolabile MTHFR (n = 5) was associated with higher Hcy levels and better response to treatment (Hcy levels decreased by 58%, from 46.2 ± 14.6 to 19.48 ± 4.1 mmol/L following treatment). In patients with heterozygous thermolabile MTHFR (n = 25), Hcy levels decreased by 34%, from 31.2 ± 3.7 to 18.1 ± 1.1 mmol/L following treatment. The efficacy of high and low doses of B-vitamins on the reduction of homocysteine levels was comparable.

Conclusions: Treatment with B-vitamins in combination with folic acid significantly decreased homocysteine levels in hemodialysis patients, independently of the tested doses. In addition, mutations in MTHFR were associated with elevated plasma levels of Hcy. Neither vascular access nor.

Background: A high total plasma homocysteine level is an independent risk factor for cardiovascular and cerebrovascular disease, but the evidence connecting plasma tHcy level with hypertension is inconsistent.

Objective: To determine the association between plasma tHcy level and some common risk factors for cerebrovascular disease (recurrent  stroke, diabetes mellitus, hypertension, ischemic heart disease and hyperlipidemia) in patients presenting with primary or recurrent acute ischemic strokes.

Methods: This retrospective cross-sectional chart analysis was conducted in a university-affiliated referral hospital. During an 18 month period we identified 113 acute ischemic stroke patients (mean age 71.2), 25 of whom had a recurrent stroke. Plasma tHcy[1] level, obtained 2–10 days after stroke onset, was determined by the high performance liquid chromatography method with fluorescence detection. A multivariate logistic regression model was used to determine the independent relationship between each potential risk factor and tHcy level above or below the 75th percentile.

Results:  Hypertension was more frequent among patients with plasma tHcy level above than below the 75th percentile (51.7% vs. 80.8%, respectively, P = 0.012). After adjusting for demographic and clinical variables, the odds ratio for recurrent stroke and hypertension, with tHcy above or below the 75th percentile, was 3.4 (95% confidence interval 1.01–10.4, P = 0.037) and 4.02 (95% CI[2] 1.2–13.9, P = 0.028), respectively.

Conclusions: A high plasma tHcy level is associated with history of hypertension and recurrent stroke among patients presenting with acute ischemic stroke. These results were independent of other risk factors such as atrial fibrillation, diabetes and hyperlipidemia. Hypertensive stroke patients with hyperhomocysteinemia should be identified as high risk patients as compared to non-hypertensive stroke patients, and may warrant more vigorous measures for secondary prevention.