Expandable metal biliary stenting in patients with recurrent premature polyethylene stent occlusion

OBJECTIVES: Expandable metal stents are currently used to treat biliary tract obstruction. Few data exist on the role of metal stents in patients with recurrent premature plastic biliary stent occlusion. We report our preliminary results using an expandable metal biliary stent with enhanced stent flexibility in this group of patients. Our aim was to assess the efficacy of the Diamond biliary stent in the treatment of recurrent premature biliary plastic stent blockage. METHODS: From September 1997 to June 1998, six patients with inoperable biliary obstruction and at least one prior episode of plastic stent occlusion were treated with an expandable metal biliary prosthesis. There were four women and six men, with a mean age of 73+/-11 yr. Five patients had malignant biliary obstruction, and one inoperable patient had a biliary stricture secondary to chronic pancreatitis. Patients were followed-up prospectively until either stent occlusion or death. The patency duration of the metal stents was compared to that of the most recently placed plastic stents. RESULTS: All stents were successfully inserted endoscopically with visualized biliary drainage. No significant immediate postprocedural complications were noted. Median time from initial diagnosis of biliary obstruction to metal stent insertion was 35 wk (range 7-142), during which time patients had occluded a median of 4.5 plastic stents (range 2-5). Median patient survival was 117 days (15-312) and median time to blockage of the last plastic stent was 25.5 days (range 10-90 days). Three cases of metal stent occlusion occurred. One patient had early stent occlusion at 9 days because of debris and sludge clogging the metal stent. Two other patients developed stent occlusion at 120 and 157 days. Two stents remained patent until the patients' deaths at 15 and 87 days. Overall median stent patency was 139 days. The three patients who developed stent occlusion were treated with successful insertion of one or more plastic stents through the existing metal stent. Duration of metal stent patency was significantly longer than that of the last plastic stent (58.8 days longer; 95% CI [6.4, 111]; p = 0.03). CONCLUSIONS: Metal biliary prostheses represent an effective management strategy for recurrent plastic biliary stent obstruction. Patients in this subgroup may have a shorter duration of metal stent patency than the reported duration of stent patency in patients receiving initial metal stent placement. However the duration of patency still seems to be significantly longer than that of the most recently placed plastic stent.     

How the Term ‘Self-Management’ is Used in HIV Research in Low- and Middle-Income Countries: A Scoping Review

AIDS and Behavior - This scoping review assessed how the term ‘self-management’ (SM) is used in peer-reviewed literature describing HIV populations in low- and middle-income countries...     

Effect of nutrition counselling with a digital job aid on child dietary diversity: Analysis of secondary outcomes from a cluster randomised controlled trial in rural Bangladesh

Adequate dietary diversity among infants is often suboptimal in developing countries. We assessed the impact of nutrition counselling using a digital job aid on dietary diversity of children aged 6–23 months using data from a cluster randomised controlled trial in Bangladesh. The trial had five arms, each with 25 clusters. The four intervention arms provided counselling using a digital job aid and different prenatal and post-natal combinations of lipid-based supplements and the comparison arm with usual practice. We enrolled 1500 pregnant women and followed them until the children reached their second birthday. We developed a tablet-based system for intervention delivery, data collection and project supervision. We combined the four intervention arms (n = 855), in which community health workers (CHWs) provided age-appropriate complementary feeding counselling, to compare against the comparison arm (n = 403). We calculated the outcome indicators from the children's 24-h dietary recalls. Overall, the intervention increased the mean dietary diversity score by 0.09 (95% confidence interval [CI]: 0.2–0.16) and odds of minimum dietary diversity by 18% (95% CI: 0.99–1.40). However, there was a significant interaction on the effect of the intervention on dietary diversity by age. The mean dietary diversity score was 0.24 (95% CI: 0.11–0.37) higher in the intervention than in the comparison arm at 9 months and 0.14 (95% CI: 0.01–27) at 12 months of age. The intervention effect was non-significant at an older age. Overall, consumption of flesh food was 1.32 times higher in the intervention arm (odds ratio [OR] 1.32, 95% CI: 1.11–1.57) in 6–23 months of age. The intervention significantly improved child dietary diversity score in households with mild and moderate food insecurity by 0.27 (95% CI: 0.06–0.49) and 0.16 (0.05–27), respectively, but not with food-secure and severely food-insecure households. Although the study did not evaluate the impact of digital job aid alone, the findings indicate the utility of nutrition counselling by CHWs using a digital job aid to improve child feeding practices in broader programmes.     

Chromosome 17p deletions and p53 gene mutations associated with the formation of malignant neurofibrosarcomas in von Recklinghausen neurofibromatosis.

von Recklinghausen neurofibromatosis (NF1) is a common hereditary disorder characterized by neural crest-derived tumors, particularly benign neurofibromas whose malignant transformation to neurofibrosarcomas can be fatal. The NF1 gene has been mapped to a small region of chromosome 17q, but neither the nature of the primary defect nor the mechanisms involved in tumor progression are understood. We have tested whether NF1 might be caused by the inactivation of a tumor suppressor gene on 17q, analogous to that on chromosome 22 in NF2, by searching for deletions of chromosome 17 in NF1-derived tumor specimens. Both neurofibrosarcomas from patients with "atypical" NF and 5 of 6 neurofibrosarcomas from NF1 patients displayed loss of alleles for polymorphic DNA markers on chromosome 17. However, the common region of deletion was on 17p and did not include the NF1 region of 17q. Since no loss of markers on chromosome 17 was observed in any of 30 benign tumors from NF1 patients, the 17p deletions seen in neurofibrosarcomas are probably associated with tumor progression and/or malignancy. This region contains a candidate gene for tumor progression, p53, which has recently been implicated in the progression of a broad array of human cancers. In a preliminary search for p53 aberrations by direct sequencing of polymerase chain reaction-amplified DNA from 7 neurofibrosarcomas, 2 tumors that contained point mutations in exon 4 of the p53 gene were found, suggesting a role for this gene in at least some neurofibrosarcomas. Thus the formation of malignant neurofibrosarcomas may result from several independent genetic events including mutation of the NF1 gene, whose mechanism of tumorigenesis remains uncertain, and subsequent loss of a "tumor suppressor" gene on 17p, most likely p53.     

Role of copper in mitochondrial iron metabolism

Heme synthesis by copper-deficient cells was investigated to elucidate the nature of the defect in intracellular iron metabolism. Iron uptake from transferrin by copper-deficient reticulocytes was 52% of normal, and the rate of heme synthesis was 33% of normal. Hepatic mitochondria isolated from copper-deficient animals were deficient in cytochrome oxidase activity and failed to synthesize heme from ferric iron (Fe III) and protoporphyrin at the normal rate. The rate of heme synthesis correlated with the cytochrome oxidase activity. Heme synthesis from Fe(III) and protoporphyrin by normal mitochondria was enhanced by succinate and inhibited by malonate, antimycin A, azide, and cyanide. It is proposed that an intact electron transport system is required for the reduction of Fe(III), thereby providing a pool of ferrous iron (Fe II) for protoheme and heme a synthesis.     

Unruptured sinus of Valsalva aneurysm with right ventricular outflow obstruction

The recommended operative management of unruptured sinus of Valsalva aneurysm consists of closure of the mouth of the aneurysm with or without aortic valve surgery. We report a case of unruptured aneurysm producing right ventricular outflow tract obstruction. Closure of the mouth of the aneurysm failed to relieve the obstruction, which was subsequently achieved by excising the aneurysmal wall overlying the outflow tract.     

Evaluating Mitochondrial DNA Variation in Autism Spectrum Disorders

Despite the increasing speculation that oxidative stress and abnormal energy metabolism may play a role in Autism Spectrum Disorders (ASD), and the observation that patients with mitochondrial defects have symptoms consistent with ASD, there are no comprehensive published studies examining the role of mitochondrial variation in autism. Therefore, we have sought to comprehensively examine the role of mitochondrial DNA (mtDNA) variation with regard to ASD risk, employing a multi‐phase approach. In phase 1 of our experiment, we examined 132 mtDNA single‐nucleotide polymorphisms (SNPs) genotyped as part of our genome‐wide association studies of ASD. In phase 2 we genotyped the major European mitochondrial haplogroup‐defining variants within an expanded set of autism probands and controls. Finally in phase 3, we resequenced the entire mtDNA in a subset of our Caucasian samples (～400 proband‐father pairs). In each phase we tested whether mitochondrial variation showed evidence of association to ASD. Despite a thorough interrogation of mtDNA variation, we found no evidence to suggest a major role for mtDNA variation in ASD susceptibility. Accordingly, while there may be attractive biological hints suggesting the role of mitochondria in ASD our data indicate that mtDNA variation is not a major contributing factor to the development of ASD.