33 research outputs found

    2-Deoxy-2[F-18]FDG-PET for Detection of Recurrent Laryngeal Carcinoma after Radiotherapy: Interobserver Variability in Reporting

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    Purpose: To evaluate accuracy and interobserver variability in the assessment of 2-deoxy-2[F-18]fluoro-d-glucose-positron emission tomography (FDG-PET) for detection of recurrent laryngeal carcinoma after radiotherapy. Procedures: Eleven experienced nuclear physicians from eight centres assessed 30 FDG-PET scans on the appearance of local recurrence (negative/equivocal/positive). Conservative (equivocal analysed as negative) and sensitive (equivocal analysed as positive) assessment strategies were compared to the reference standard (recurrence within 6months after PET). Results: Seven patients had proven recurrences. For the conservative and sensitive strategy, the mean sensitivity was 87% and 97%, specificity 81% and 63%, positive predictive values 61% and 46% and negative predictive values 96% and 99%, respectively. Interobserver variability showed a reasonable relation in comparison to the reference standard (kappa = 0.55). Conclusions: FDG-PET has acceptable interobserver agreement and yields good negative predictive value for detection of recurrent laryngeal carcinoma. It could therefore be used as first diagnostic step and may reduce futile invasive diagnostics

    Unsuccessful therapy with adefovir and entecavir-tenofovir in a patient with chronic hepatitis B infection with previous resistance to lamivudine: a fourteen-year evolution of hepatitis B virus mutations

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    <p>Abstract</p> <p>Background</p> <p>Complex mutants can be selected under sequential selective pressure by HBV therapy. To determine hepatitis B virus genomic evolution during antiviral therapy we characterized the HBV quasi-species in a patient who did no respond to therapy following lamivudine breakthrough for a period of 14 years.</p> <p>Case Presentation</p> <p>The polymerase and precore/core genes were amplified and sequenced at determined intervals in a period of 14 years. HBV viral load and HBeAg/Anti-HBe serological profiles as well as amino transferase levels were also measured. A mixture of lamivudine-resistant genotype A2 HBV strains harboring the rtM204V mutation coexisted in the patient following viral breakthrough to lamivudine. The L180M+M204V dominant mutant displayed strong lamivudine-resistance. As therapy was changed to adefovir, then to entecavir, and finally to entecavir-tenofovir the viral load showed fluctuations but lamivudine-resistant strains continued to be selected, with minor contributions to the HBV quasi-species composition of additional resistance-associated mutations. At the end of the 14-year follow up period, high viral loads were predominant, with viral strains harboring the lamivudine-resistance signature rtL180M+M204V. The precore/core frame A1762T and G1764A double mutation was detected before treatment and remaining in this condition during the entire follow-up. Specific entecavir and tenofovir primary resistance-associated mutations were not detected at any time. Plasma concentrations of tenofovir indicated adequate metabolism of the drug.</p> <p>Conclusions</p> <p>We report the selection of HBV mutants carrying well-defined primary resistance mutations that escaped lamivudine in a fourteen-year follow-up period. With the exception of tenofovir resistance mutations, subsequent unselected primary resistance mutations were detected as minor populations into the HBV quasispecies composition during adefovir or entecavir monotherapies. Although tenofovir is considered an appropriate therapeutic alternative for the treatment of entecavir-unresponsive patients, its use was not effective in the case reported here.</p

    Efficient Targeting of Head and Neck Squamous Cell Carcinoma by Systemic Administration of a Dual uPA and MMP-Activated Engineered Anthrax Toxin

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    Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Although considerable progress has been made in elucidating the etiology of the disease, the prognosis for individuals diagnosed with HNSCC remains poor, underscoring the need for development of additional treatment modalities. HNSCC is characterized by the upregulation of a large number of proteolytic enzymes, including urokinase plasminogen activator (uPA) and an assortment of matrix metalloproteinases (MMPs) that may be expressed by tumor cells, by tumor-supporting stromal cells or by both. Here we explored the use of an intercomplementing anthrax toxin that requires combined cell surface uPA and MMP activities for cellular intoxication and specifically targets the ERK/MAPK pathway for the treatment of HNSCC. We found that this toxin displayed strong systemic anti-tumor activity towards a variety of xenografted human HNSCC cell lines by inducing apoptotic and necrotic tumor cell death, and by impairing tumor cell proliferation and angiogenesis. Interestingly, the human HNSCC cell lines were insensitive to the intercomplementing toxin when cultured ex vivo, suggesting that either the toxin targets the tumor-supporting stromal cell compartment or that the tumor cell requirement for ERK/MAPK signaling differs in vivo and ex vivo. This intercomplementing toxin warrants further investigation as an anti-HNSCC agent

    Future prospectives for the management of chronic hepatitis B

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    Future prospectives for the management of chronic hepatitis B

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    Chronic hepatitis B virus infection affects about 400 million people around the globe and causes approximately one million deaths a year. Since the discovery of interferon-Ξ± as a therapeutic option the treatment of hepatitis B has evolved fast and management has become increasingly complicated. The amount of viral replication reflected in the viral load (HBV-DNA) plays an important role in the development of cirrhosis and hepatocellular carcinoma. The current treatment modalities for chronic hepatitis B are immunomodulatory (interferons) and antiviral suppressants (nucleoside and nucleotide analogues) all with their own advantages and limitations. An overview of the treatment efficacy for both immunomodulatory as antiviral compounds is provided in order to provide the clinician insight into the factors influencing treatment outcome. With nucleoside or nucleotide analogues suppression of viral replication by 5-7 log(10) is feasible, but not all patients respond to therapy. Known factors influencing treatment outcome are viral load, ALT levels and compliance. Many other factors which might influence treatment are scarcely investigated. Identifying the factors associated with response might result in stopping rules, so treatment could be adapted in an early stage to provide adequate treatment and avoid the development of resistance. The efficacy of compounds for the treatment of mutant virus and the cross-resistance is largely unknown. However, genotypic and phenotypic testing as well as small clinical trials provided some data on efficacy in this population. Discontinuation of nucleoside or nucleotide analogues frequently results in viral relapse; however, some patients have a sustained response. Data on the risk factors for relapse are necessary in order to determine when treatment can be discontinued safely. In conclusion: chronic hepatitis B has become a treatable disease; however, much research is needed to tailor therapy to an individual patient, to predict the sustainability of response and determine the best treatment for those failing treatment

    Exacerbation of chronic hepatitis B infection after delivery

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    During pregnancy several alterations in the immune status allow mothers to tolerate the genetically different foetal tissues. We investigated the evolution of liver disease during and after pregnancy in chronic hepatitis B patients. Between 1998 and 2006 there were 38 pregnancies in 31 chronic hepatitis B 's' antigen-positive women at our liver unit. Twenty-four subjects (63%) were hepatitis B 'e' antigen (HBeAg)-positive, 14 (37%) HBeAg-negative. In 13 pregnancies (34%), lamivudine therapy was started during the last trimester of pregnancy to lower hepatitis B virus (HBV) DNA levels to reduce the risk of vertical transmission. A significant increase in liver disease activity after pregnancy, defined as a three times increase in alanine aminotransferase (ALT) within 6 months after delivery, occurred in 17 of 38 patients (45%). In those treated with lamivudine during the last trimester of pregnancy, this occurred in even 8/13 patients (62%). Prediction during pregnancy of these exacerbations was not possible using HBV DNA, ALT level, HBeAg status or any other characteristic. The median maximal ALT of these exacerbations was 4.0 x ULN and none led to decompensated liver disease. In conclusion, a significant increase in liver inflammation occurs often after pregnancy. This may be due to a reactivation of the immune system after delivery. Based on our data we recommend monitoring closely and if necessary treating women with chronic HBV shortly after delivery

    On-treatment monitoring of adefovir therapy in chronic hepatitis B: virologic response can be assessed at 24 weeks

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    Patients with chronic hepatitis B (CHB) who will and those who will not respond to adefovir (ADV) monotherapy need to be identified at an early stage in order to adjust treatment and prevent future development of antiviral resistance. In a single-centre cohort study, we investigated 76 CHB patients [50% hepatitis B e antigen (HBeAg)-positive] treated with long-term ADV monotherapy. During a median follow-up of 122 (24-185) weeks, 42 (55%) patients achieved virologic response (VR), defined as HBV-DNA levels &lt; 10(3) copies/mL, and 10 patients (13%) developed genotypic ADV resistance. Independent baseline predictors of VR were HBeAg negativity [hazard ratio (HR) 2.98; 95% confidence interval (CI) 1.24-7.19; P = 0.02], high alanine aminotransferase (ALT) levels (HR 1.11; 95% CI 1.05-1.18; P = 0.001), and low HBV-DNA levels (HR 0.56; 95% CI 0.41-0.75; P &lt; 0.001). HBV-DNA at week 24 demonstrated a higher predictive value for VR than HBV-DNA at week 48. Important predictors of genotypic resistance were presence of cirrhosis (HR 6.54; 95% CI 1.39-30.9; P = 0.018), and not achieving VR during treatment (HR 6.60; 95% CI 1.35-32.4; P = 0.008). Patients without VR at week 24 already demonstrated a trend towards the emergence of ADV resistance (P = 0.07). HBV-DNA at week 24 was a better on-treatment predictor of VR than HBV-DNA at week 48, and ADV-resistant mutations developed more frequently in patients without VR at week 24. Therefore, our study suggests that virologic response to ADV therapy can be assessed at 24 weeks, instead of the generally recommended 48 weeks
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