Evidence of DNA methylation in the neurofibromatosis type 1 (NF1) gene region of 17q11.2

Modification of mammalian DNA by the methylation of cytosinein CpG dinucleotides is a complex phenomenon involved in a numberof cellular and developmental processes. In a particular, thecharacteristic hypermutability of CpGs may be a major contributorof point mutations leading to human genetic disease. We havehypothesized that DNA methylation contributes to mutations inthe gene causing neurofibromatosis type 1 (NF1), one of themost common genetic disorders in humans and a disease whereup to half of all cases are the result of sporadic germlinemutations, usually in the paternally-derived allele. We haveused two experimental approaches to analyze patterns of DNAmethylation at CpG dinucleotides in the NF1 gene region. Southernanalyses using isoschizomeric restriction pairs have revealedDNA methylation in areas flanking the NF1 gene region, whilePCR-methylation assays have shown that methylation occurs bothon genomic sequences flanking the NF1 gene and within the codingregion of the gene itself. We suggest that methylated CpG dinucleotideswithin and around the highly mutable NF1 gene serve as a reservoirwithin which C-T transitions contribute to the high frequencyof spontaneous germline mutations associated with the disease.     

(-)-Epigallocatechin gallate as an intervention for the acute treatment of cerebral ischemia

This study examined the neuroprotective effects and possible hepatotoxicity of (-)-epigallocatechin gallate (EGCG) in a rat model of transient focal cerebral ischemia. Male Sprague-Dawley rats (265-295 g) were treated with either 50 mg kg(-1) of EGCG or saline, i.p., immediately post-ischemia and every day thereafter, in a middle cerebral artery occlusion model of stroke. Sacrifice occurred 72 h post-ischemia and 2,3,5-triphenyltetrazolium chloride staining was used to quantify neuronal infarction. Hepatotoxicity was determined by taking blood samples for plasma alanine aminotransferase (ALT) activity. Spleen, kidney, liver and testes wet weights were also recorded. Total infarct volume was significantly (P<0.05) reduced in the EGCG-treated group as compared to controls. Analysis of the mean infarct area showed a significant (P<0.05) decrease in slices 6 and 7 in the EGCG-treated group. No significant differences were found in organ weights or ALT levels between treatment groups. Our findings, in part, validate and extend previous observations illustrating that 50 mg kg(-1), i.p. EGCG is non-toxic and neuroprotective. However, we also found that EGCG treatment appreciably increased (>50%) the number of animals that developed an intracerebral hemorrhage. We therefore conclude that 50 mg kg(-1) EGCG is not a viable intervention for the acute treatment of cerebral ischemia, as it is likely to increase the risk of intracerebral hemorrhaging.     

Effects of interferon beta-1b on black holes in multiple sclerosis over a 6-year period with monthly evaluations

BACKGROUND: Chronic, hypointense black holes (BHs) are recognized as a sign of permanent damage in patients with multiple sclerosis. Although the effects of interferon beta-1b in reducing the formation of new BHs are established, it is not clear whether the drug may reduce BH duration after these lesions are formed. OBJECTIVE: To analyze the effects of interferon beta-1b in reducing the duration of T1 BHs in patients with multiple sclerosis. DESIGN: Patients were clinically assessed and imaged monthly over a 36-month natural history phase and 36-month therapy phase. Numbers of contrast-enhanced lesions and newly formed BHs were counted on each scan. Each BH was counted until it was no longer seen. SETTING: Outpatient service of the Neuroimmunology Branch at the National Institutes of Health, Bethesda, Md. PATIENTS: Six patients with relapsing-remitting multiple sclerosis were included. One patient did not form any BHs during the therapy phase. Analyses were performed on the remaining 5 individuals. INTERVENTIONS: Interferon beta-1b at the dosage of 8 million international units every other day. MAIN OUTCOME MEASURES: Number and duration (in months) of newly formed BHs. RESULTS: Rate of BH accumulation decreased with treatment (P = .01), but Kaplan-Meier models revealed that the duration of BHs did not shorten (chi2(1) = 2.47, P = .12). CONCLUSIONS: Interferon beta-1b reduces the frequency of new BH formation but does not appear to decrease their duration in time. Analyses with larger patient cohorts are needed to confirm these preliminary findings.     

Clinical implications of quantification of mesorectal tumor invasion by endoscopic ultrasound: All T3 rectal cancers are not equal

BACKGROUND: Depth of invasion beyond the muscularis propria (MP) by T3 rectal cancer can vary. The purpose of the present paper was to determine if depth of invasion beyond MP, as assessed by preoperative endoscopic ultrasound (EUS), can predict tumor recurrence in patients with T3 rectal tumors. METHODS: Patients with T3NxM0 rectal cancer, as determined by EUS, who underwent surgical resection (without preoperative neoadjuvant therapy) were reviewed by two blinded endosonographers. Tumors were classified as minimally invasive T3 (invasion 2 mm). RESULTS: Forty-two patients with T3 rectal tumors underwent surgical resection without receiving preoperative neoadjuvant therapy, of whom 14 had minimally invasive T3 and 28 had advanced T3 disease, as determined by preoperative EUS. Median follow up was 19 months. Tumor recurrence rates in minimally invasive and advanced T3 tumors were 14.3% and 39.3%, respectively, P = 0.02 (log-rank test). Adjusting for nodal status and postoperative adjuvant therapy administration, Cox proportional hazards model demonstrated advanced T3 disease (by EUS) to predict tumor recurrence, hazard ratio, 2.28 (95% confidence interval: 1.17-5.81), P = 0.01. CONCLUSIONS: All T3 rectal tumors are not equal, with minimally invasive disease carrying a more favorable prognosis. By discriminating minimally invasive from advanced T3 disease, preoperative EUS provides important prognostic information. Further subclassification of T3 tumors, based on preoperative EUS staging, should be considered to enhance selection of patients for neoadjuvant therapy.     

Health sector policy in the first decade of Nepal's multiparty democracy. Does clear enunciation of health priorities matter?

Nepal experienced a significant political regime shift in 1990 from the partyless Panchyat system to the present multiparty form of democracy. While political instability existed in the decade of the 1990s, reflected in the approximately one government per year, there had been continued enunciation of health policy priorities toward the rural sector, as reflected in the Nepal National Health Policy, 1991 (NHP (1991)) and subsequent plans. The objective of the paper is to assess whether clear enunciation of health priorities have translated into beneficial health outcomes, reflected in reduction of the child death rate, child morality rate, infant mortality rate and increase in the life expectancy rate. This question is assessed empirically over the 10-year period of fiscal year 1989/1990 to 1999/2000 using mainly secondary data published by His Majesty's Government of Nepal (HMG/N), through the perspectives of input-output model and extension of health services, along with an indicative regression of a Nepalese health production function. The results (i.e. empirical observations) suggest that while there have been clear enunciation of health priorities, there have not been significant positive effects on health sector outcomes. The paper ends with a number of recommendations and concludes with the necessity for effective and appropriate implementation.