200 research outputs found

    Overdiagnosis and overtreatment of breast cancer: Rates of ductal carcinoma in situ: a US perspective

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    The incidence of breast ductal carcinoma in situ (DCIS) in the USA exceeds that of other countries. This cannot be explained entirely by the frequency of mammographic screening in the USA and may result from differences in the interpretation of mammograms and/or the frequency with which biopsies are obtained. Although the percentage of DCIS patients treated with mastectomy has decreased, the absolute number is unchanged and the use of lumpectomy with whole-breast radiotherapy has increased in inverse proportion to the decrease in mastectomy. Treatment of DCIS with tamoxifen is still limited

    Interactions between cigarette and alcohol consumption in rural China

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    The objective of this paper is to analyze interdependencies between cigarette and alcohol consumption in rural China, using panel data for 10 years (1994–2003) for rural areas of 26 Chinese provinces. There have been many studies in which cigarette and alcohol consumption have been considered separately but few to date for China on interactions between the consumption of these two products. Taxes are often recommended as a tool to reduce alcohol and cigarette consumption. If cigarettes and alcohol are complements, taxing one will reduce the consumption of both and thus achieve a double public health dividend. However, if they are substitutes, taxing one will induce consumers to increase consumption of the other, offsetting the public health benefits of the tax. Our results indicate that the demands for both cigarettes and alcohol are very sensitive to the price of alcohol, but not to the price of cigarettes or to income. This suggests that taxes on alcohol can have a double dividend. On the other hand, an increase in cigarette taxes may not be effective in curbing cigarette or alcohol consumption in rural China

    Influence of Ni Catalyst Layer and TiN Diffusion Barrier on Carbon Nanotube Growth Rate

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    Dense, vertically aligned multiwall carbon nanotubes were synthesized on TiN electrode layers for infrared sensing applications. Microwave plasma-enhanced chemical vapor deposition and Ni catalyst were used for the nanotubes synthesis. The resultant nanotubes were characterized by SEM, AFM, and TEM. Since the length of the nanotubes influences sensor characteristics, we study in details the effects of changing Ni and TiN thickness on the physical properties of the nanotubes. In this paper, we report the observation of a threshold Ni thickness of about 4 nm, when the average CNT growth rate switches from an increasing to a decreasing function of increasing Ni thickness, for a process temperature of 700°C. This behavior is likely related to a transition in the growth mode from a predominantly “base growth” to that of a “tip growth.” For Ni layer greater than 9 nm the growth rate, as well as the CNT diameter, variations become insignificant. We have also observed that a TiN barrier layer appears to favor the growth of thinner CNTs compared to a SiO2 layer

    Limitations of Tc99m-MIBI-SPECT Imaging Scans in Persistent Primary Hyperparathyroidism

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    In primary hyperparathyroidism (PHPT) the predictive value of technetium 99m sestamibi single emission computed tomography (Tc99m-MIBI-SPECT) for localizing pathological parathyroid glands before a first parathyroidectomy (PTx) is 83-100%. Data are scarce in patients undergoing reoperative parathyroidectomy for persistent hyperparathyroidism. The aim of the present study was to determine the value of Tc99m-MIBI-SPECT in localizing residual hyperactive parathyroid tissue in patients with persistent primary hyperparathyroidism (PHPT) after initial excision of one or more pathological glands. We retrospectively evaluated the localizing accuracy of Tc99m-MIBI-SPECT scans in 19 consecutive patients with persistent PHPT who had a scan before reoperative parathyroidectomy. We used as controls 23 patients with sporadic PHPT who had a scan before initial surgery. In patients with persistent PHPT, Tc99m-MIBI-SPECT accurately localized a pathological parathyroid gland in 33% of cases before reoperative parathyroidectomy, compared to 61% before first PTx for sporadic PHPT. The Tc99m-MIBI-SPECT scan accurately localized intra-thyroidal glands in 2 of 7 cases and a mediastinal gland in 1 of 3 cases either before initial or reoperative parathyroidectomy. Our data suggest that the accuracy of Tc99m-MIBI-SPECT in localizing residual hyperactive glands is significantly lower before reoperative parathyroidectomy for persistent PHPT than before initial surgery for sporadic PHPT. These findings should be taken in consideration in the preoperative workup of patients with persistent primary hyperparathyroidis

    Functions of Some Capsular Polysaccharide Biosynthetic Genes in Klebsiella pneumoniae NTUH K-2044

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    The growing number of Klebsiella pneumoniae infections, commonly acquired in hospitals, has drawn great concern. It has been shown that the K1 and K2 capsular serotypes are the most detrimental strains, particularly to those with diabetes. The K1 cps (capsular polysaccharide) locus in the NTUH-2044 strain of the pyogenic liver abscess (PLA) K. pneumoniae has been identified recently, but little is known about the functions of the genes therein. Here we report characterization of a group of cps genes and their roles in the pathogenesis of K1 K. pneumoniae. By sequential gene deletion, the cps gene cluster was first re-delimited between genes galF and ugd, which serve as up- and down-stream ends, respectively. Eight gene products were characterized in vitro and in vivo to be involved in the syntheses of UDP-glucose, UDP-glucuronic acid and GDP-fucose building units. Twelve genes were identified as virulence factors based on the observation that their deletion mutants became avirulent or lost K1 antigenicity. Furthermore, deletion of kp3706, kp3709 or kp3712 (ΔwcaI, ΔwcaG or Δatf, respectively), which are all involved in fucose biosynthesis, led to a broad range of transcriptional suppression for 52 upstream genes. The genes suppressed include those coding for unknown regulatory membrane proteins and six multidrug efflux system proteins, as well as proteins required for the K1 CPS biosynthesis. In support of the suppression of multidrug efflux genes, we showed that these three mutants became more sensitive to antibiotics. Taken together, the results suggest that kp3706, kp3709 or kp3712 genes are strongly related to the pathogenesis of K. pneumoniae K1

    Gebiss: an ImageJ plugin for the specification of ground truth and the performance evaluation of 3D segmentation algorithms.

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    Background: Image segmentation is a crucial step in quantitative microscopy that helps to define regions of tissues, cells or subcellular compartments. Depending on the degree of user interactions, segmentation methods can be divided into manual, automated or semi-automated approaches. 3D image stacks usually require automated methods due to their large number of optical sections. However, certain applications benefit from manual or semi-automated approaches. Scenarios include the quantification of 3D images with poor signal-to-noise ratios or the generation of so-called ground truth segmentations that are used to evaluate the accuracy of automated segmentation methods. Results: We have developed Gebiss; an ImageJ plugin for the interactive segmentation, visualisation and quantification of 3D microscopic image stacks. We integrated a variety of existing plugins for threshold-based segmentation and volume visualisation. Conclusions: We demonstrate the application of Gebiss to the segmentation of nuclei in live Drosophila embryos and the quantification of neurodegeneration in Drosophila larval brains. Gebiss was developed as a cross-platform ImageJ plugin and is freely available on the web at http://imaging.bii.a-star.edu.sg/projects/gebiss

    The Impact of Matching Vaccine Strains and Post-SARS Public Health Efforts on Reducing Influenza-Associated Mortality among the Elderly

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    Public health administrators do not have effective models to predict excess influenza-associated mortality and monitor viral changes associated with it. This study evaluated the effect of matching/mismatching vaccine strains, type/subtype pattern changes in Taiwan's influenza viruses, and the impact of post-SARS (severe acute respiratory syndrome) public health efforts on excess influenza-associated mortalities among the elderly. A negative binomial model was developed to estimate Taiwan's monthly influenza-associated mortality among the elderly. We calculated three winter and annual excess influenza-associated mortalities [pneumonia and influenza (P&I), respiratory and circulatory, and all-cause] from the 1999–2000 through the 2006–2007 influenza seasons. Obtaining influenza virus sequences from the months/years in which death from P&I was excessive, we investigated molecular variation in vaccine-mismatched influenza viruses by comparing hemagglutinin 1 (HA1) of the circulating and vaccine strains. We found that the higher the isolation rate of A (H3N2) and vaccine-mismatched influenza viruses, the greater the monthly P&I mortality. However, this significant positive association became negative for higher matching of A (H3N2) and public health efforts with post-SARS effect. Mean excess P&I mortality for winters was significantly higher before 2003 than after that year [mean ± S.D.: 1.44±1.35 vs. 0.35±1.13, p = 0.04]. Further analysis revealed that vaccine-matched circulating influenza A viruses were significantly associated with lower excess P&I mortality during post-SARS winters (i.e., 2005–2007) than during pre-SARS winters [0.03±0.06 vs. 1.57±1.27, p = 0.01]. Stratification of these vaccine-matching and post-SARS effect showed substantial trends toward lower elderly excess P&I mortalities in winters with either mismatching vaccines during the post-SARS period or matching vaccines during the pre-SARS period. Importantly, all three excess mortalities were at their highest in May, 2003, when inter-hospital nosocomial infections were peaking. Furthermore, vaccine-mismatched H3N2 viruses circulating in the years with high excess P&I mortality exhibited both a lower amino acid identity percentage of HA1 between vaccine and circulating strains and a higher numbers of variations at epitope B. Our model can help future decision makers to estimate excess P&I mortality effectively, select and test virus strains for antigenic variation, and evaluate public health strategy effectiveness

    Nonvirally Modified Autologous Primary Hepatocytes Correct Diabetes and Prevent Target Organ Injury in a Large Preclinical Model

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    BACKGROUND: Current gene- and cell-based therapies have significant limitations which impede widespread clinical application. Taking diabetes mellitus as a paradigm, we have sought to overcome these limitations by ex vivo electrotransfer of a nonviral insulin expression vector into primary hepatocytes followed by immediate autologous reimplantation in a preclinical model of diabetes. METHODS AND RESULTS: In a single 3-hour procedure, hepatocytes were isolated from a surgically resected liver wedge, electroporated with an insulin expression plasmid ex vivo and reimplanted intraparenchymally under ultrasonic guidance into the liver in each of 10 streptozotocin-induced diabetic Yorkshire pigs. The vector was comprised of a bifunctional, glucose-responsive promoter linked to human insulin cDNA. Ambient glucose concentrations appropriately altered human insulin mRNA expression and C-peptide secretion within minutes in vitro and in vivo. Treated swine showed correction of hyperglycemia, glucose intolerance, dyslipidemia and other metabolic abnormalities for > or = 47 weeks. Metabolic correction correlated significantly with the number of hepatocytes implanted. Importantly, we observed no hypoglycemia even under fasting conditions. Direct intrahepatic implantation of hepatocytes did not alter biochemical indices of liver function or induce abnormal hepatic lobular architecture. About 70% of implanted hepatocytes functionally engrafted, appeared histologically normal, retained vector DNA and expressed human insulin for > or = 47 weeks. Based on structural tissue analyses and transcriptome data, we showed that early correction of diabetes attenuated and even prevented pathological changes in the eye, kidney, liver and aorta. CONCLUSIONS: We demonstrate that autologous hepatocytes can be efficiently, simply and safely modified by electroporation of a nonviral vector to express, process and secrete insulin durably. This strategy, which achieved significant and sustained therapeutic efficacy in a large preclinical model without adverse effects, warrants consideration for clinical development especially as it could have broader future applications for the treatment of other acquired and inherited diseases for which systemic reconstitution of a specific protein deficiency is critical

    Treatment of hepatocellular carcinoma with major portal vein thrombosis by combined therapy with subcutaneous interferon-α and intra-arterial 5-fluorouracil; role of type 1 interferon receptor expression

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    We previously reported the beneficial effects of combination therapy of interferon (IFN)-α/5-fluorouracil (FU) for advanced hepatocellular carcinoma (HCC) with tumour thrombi in the major portal branches. This report describes the results of longer follow-up and includes more than double the number of patients relative to the original report, and evaluates the role of IFN-α/type 2 interferon receptor (IFNAR2) expression on the response to the combination therapy. The study subjects were 55 patients with advanced HCC and tumour thrombi in the major branches of the portal vein (Vp3 or 4). They were treated with at least two courses of IFN-α/5-FU without major complication. In the 55 patients, 24 (43.6%) showed objective response (eight (14.5%) showed complete response, 16 (29.1%) partial response), four (7.3%) showed no response, and 27 (49.1%) showed progressive disease. Immunohistochemically, IFNAR2 expression was detected in nine out of 13 (69.2%) patients. There was significant difference in the time-to-progression survival (P=0.0002) and the overall survival (P<0.0001) between IFNAR2-positive and -negative cases. There was a significant correlation between IFNAR2 expression and response to IFN-α/5-FU combination therapy in univariate analysis (P=0.0070). IFN-α/5-FU combination therapy is a promising modality for advanced HCC with tumour thrombi in the major portal branches and could significantly depend on IFNAR2 expression
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