298 research outputs found

    Global testing of a consensus solubility assessment to enhance robustness of the WHO biopharmaceutical classification system

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    The WHO Biopharmaceutical Classification System (BCS) is a practical tool to identify active pharmaceutical ingredients (APIs) that scientifically qualify for a waiver of in vivo bioequivalence studies. The focus of this study was to engage a global network of laboratories to experimentally quantify the pH-dependent solubility of the highest therapeutic dose of 16 APIs using a harmonized protocol. Intra-laboratory variability was ≤5 %, and no apparent association of inter-laboratory variability with API solubility was discovered. Final classification “low solubility” vs “high solubility” was consistent among laboratories. In comparison to the literature-based provisional 2006 WHO BCS classification, three compounds were re-classified from “high” to “low-solubility”. To estimate the consequences of these experimental solubility results on BCS classification, dose-adjusted in silico predictions of the fraction absorbed in humans were performed using GastroPlus®. Further expansion of these experimental efforts to qualified APIs from the WHO Essential Medicines List is anticipated to empower regulatory authorities across the globe to issue scientifically-supported guidance regarding the necessity of performing in vivo bioequivalence studies. Ultimately, this will improve access to affordable generic products, which is a critical prerequisite to reach Universal Health Coverage

    Plant productivity enhancement in a simulated Amazonian Dark Earth (Terra Preta Nova).

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    Amazonian Dark Earths (ADEs) are highly fertile human-made soils, commonly found in Amazonia. These soils have a unique soil biota and a high content of charcoal, organic C, available P and Ca as a result of repeated burning and additions of bone and organic matter (OM) over centuries of Amerindian occupation. ?Terra Preta Nova? techniques aim to replicate these soils by adding ADE components, but little is known of their single and synergistic impacts on plant productivity. We replicated an ADE by adding five distinct components and studying their single and interactive effects on maize production in the greenhouse. Earthworms (Pontoscolex corethrurus), OM (horse manure), biochar (from Brazil nut), ground fish bones and pottery sherds were added to a nutrient poor soil, and after 60 days plant height, above and below-ground (root) biomass, root length, and soil fertility levels were assessed. The main components affecting plant productivity were earthworms, OM and fish bone meal, with significant synergistic effects, while biochar and pottery, although significant, were not as important for plant growth and soil fertility

    Evaluation of HER-2/neu gene amplification and protein expression in non-small cell lung carcinomas

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    HER-2/neu gene amplification and cell surface overexpression are important factors in breast cancer for prognosis and prediction of sensitivity to anti-HER-2/neu monoclonal antibody therapy. In lung cancer, the clinical significance of HER-2/neu expression is currently under evaluation. We investigated 238 non-small lung carcinomas for HER-2/neu protein overexpression by immunohistochemistry using the HercepTest. We found 2+ or 3+ overexpression in 39 patients (16%), including 35% in adenocarcinomas and 20% in large cell carcinomas, but only 1% of squamous cell carcinomas. Marked (3+) overexpression was uncommon (4%). The association between protein expression and gene copy number per cell, as determined by fluorescence in situ hybridisation assay, was investigated in 51 of these NSCLC tumours. Twenty-seven tumours (53%) were negative by both tests. Marked (3+) protein expression and gene amplification were present in only 4% of samples. In 11 tumours (21%), gene gain was accompanied by chromosomal aneusomy and did not result in high protein levels while in 7 (14%) the score 2+ was associated with maximum number of signals per cell <9. The prognostic implication of HER-2/neu protein expression was studied in 187 surgically resected tumours. No statistical difference in survival was observed comparing patients with positive (2+/3+) and negative tumours (0/1+), although 3+ patients showed a tendency to shorter survival. The therapeutic implications of protein expression and gene amplification in lung cancer need to be examined in prospective clinical trials

    HER-2/neu amplification testing in breast cancer by Multiplex Ligation-dependent Probe Amplification: influence of manual- and laser microdissection

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    <p>Abstract</p> <p>Background</p> <p>Accurate assessment of HER-2/<it>neu </it>status is crucial for proper prognostic information and to offer direct appropriate treatment for breast cancer patients. Next to immunohistochemistry (IHC) to evaluate HER2 protein overexpression, a second line gene amplification test is generally deemed necessary for cases with equivocal protein expression. Recently, a new PCR based test, called Multiplex Ligation-dependent Probe Amplification (MLPA), was introduced as a simple and quick method to assess HER-2/<it>neu </it>gene amplification status in invasive breast cancer. MLPA was previously shown to correlate well with IHC and <it>in situ </it>hybridization (ISH), but a low tumor percentage in the tissue tested could negatively affect the accuracy of MLPA results.</p> <p>Methods</p> <p>To examine this, MLPA was repeated in 42 patients after serial H&E section guided manual dissection with a scalpel and after laser microdissection of the tumor.</p> <p>Results</p> <p>Both dissection techniques led to higher HER2 gene copy number ratios and thereby made MLPA more quantitative. Concordance between MLPA and ISH improved from 61% to 84% after manual microdissection and to 90% after laser microdissection.</p> <p>Conclusion</p> <p>Manual and laser microdissection similarly increase the dynamic range of MLPA copy number ratios which is a technical advantage. As clinically a dichotomization between normal and amplified suffices and MLPA is relatively unsensitive to tumor content, microdissection before MLPA may not be routinely necessary but may be advisable in case of very low tumor content (≤30%), when MLPA results are equivocal, or when extensive ductal carcinoma <it>in situ </it>is present. Since differences between manual and laser microdissection were small, less time consuming manual microdissection appears to be sufficient.</p

    Long-term prognostic significance of HER-2/neu in untreated node-negative breast cancer depends on the method of testing

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    INTRODUCTION: The prognostic significance of HER-2/neu in breast cancer is a matter of controversy. We have performed a study in 101 node-negative breast cancer patients with long-term follow-up not treated in the adjuvant setting, and analysed the prognostic significance of immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH), both separately and in combination, in comparison with traditional prognostic factors. METHODS: Overexpression was classified semiquantitatively according to a score (0 to 3+) (HER-2_SCO). FISH was used to analyse HER2/neu amplification (HER-2_AMP). Patients classified 2+ by IHC were examined with FISH for amplification (HER-2_ALG). Patients with 3+ overexpression as well as amplification of HER-2/neu were positive for the combined variable HER2_COM. These variables were compared with tumour size, histological grade and hormone receptor status. RESULTS: HER-2_SCO was 3+ in 20% of all tumours. HER-2_ALG was positive in 22% and amplification (HER-2_AMP) was found in 17% of all tumours. Eleven percent of the tumours showed simultaneous 3+ overexpression and amplification. Only histological grade (relative risk [RR] 3.22, 95% confidence interval [CI] 1.73–5.99, P = 0.0002) and HER-2_AMP (RR 2.47, 95% CI 1.12–5.48, P = 0.026) were significant for disease-free survival in multivariate analysis. For overall survival, both histological grade (RR 3.89, 95% CI 1.77–8.55, P = 0.0007) and HER-2_AMP (RR 3.08, 95% CI 1.24–7.66, P = 0.016) retained their independent significance. CONCLUSION: The prognostic significance of HER-2/neu in node-negative breast cancer depends on the method of testing: only the amplification of HER-2/neu is an independent prognostic factor for the long-term prognosis of untreated node-negative breast cancer
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