Limitations of the nested reverse transcriptase polymerase chain reaction on tyrosinase for the detection of malignant melanoma micrometastases in lymph nodes

The specificity and sensitivity of the nested reverse transcriptase polymerase chain reaction (RT-PCR) on tyrosinase was studied, for the detection of micrometastases of malignant melanoma. The specificity was assessed in the blood of six healthy donors, four patients with non-melanoma cancers of which one patient was treated with granulocyte-colony stimulating factor. Lymph nodes of nine patients without malignant melanoma were tested and four cell lines of various other tumours. Six of the nine non-melanoma lymph nodes were positive in this assay. The sensitivity was tested in a spike experiment in vitro, using a melanoma cell line. The detection limit was ten melanoma cells per 107peripheral blood lymphocytes. © 2000 Cancer Research Campaig

Addition of AT1 blocker fails to overcome resistance to ACE inhibition in adriamycin nephrosis

Addition of AT1 blocker fails to overcome resistance to ACE inhibition in adriamycin nephrosis.BackgroundAngiotensin-converting enzyme (ACE) inhibitors provide renoprotection, but there is considerable interindividual variability in therapeutic efficacy, with residual proteinuria and progressive renal function loss in many individuals. This requires additional strategies to optimize therapy response, particularly for individuals with a poor response to ACE inhibition. We studied whether co-treatment with an angiotensin II subtype 1 (AT1) receptor antagonist (AII-A) improves the individual antiproteinuric response of maximal ACE inhibition in established adriamycin nephrosis.MethodsRats were instituted on lisinopril (75 mg/L) six weeks after disease induction. After two weeks rats were re-stratified for residual proteinuria to continue this regimen, to a higher dose of lisinopril (150 mg/L) or to co-treatment with the AII-A L 158,809 for another four weeks. Groups on monotherapy AII-A and vehicle served as controls (all groups N = 15).ResultsLisinopril lowered proteinuria by 63% from 741 to 246 g/day (range of percentage change -90 to +2%). Neither increasing the dose of the ACE inhibitor nor addition of AII-A to ACE inhibition improved the antiproteinuric efficacy on a group or individual level: non-responders remained non-responders. All drug categories reduced hard end-points of focal glomerulosclerosis to a similar degree.ConclusionsACE inhibition has variable renal protective efficacy in the adriamycin model. Neither increasing the dose of the ACE inhibitor beyond the optimal level nor co-treatment with AII-A overcome the individual therapy resistance. Thus, in established adriamycin nephrosis, blockade of the renin-angiotensin system at two different levels offers no additional benefit over ACE inhibition alone, either on the group or individual level

Interferon-β attenuates lung inflammation following experimental subarachnoid hemorrhage

INTRODUCTION: Aneurysmal subarachnoid hemorrhage (SAH) affects relatively young people and carries a poor prognosis with a case fatality rate of 35%. One of the major systemic complications associated with SAH is acute lung injury (ALI) which occurs in up to one-third of the patients and is associated with poor outcome. ALI in SAH may be predisposed by neurogenic pulmonary edema (NPE) and inflammatory mediators. The objective of this study was to assess the immunomodulatory effects of interferon-β (IFN-β) on inflammatory mediators in the lung after experimental SAH. METHODS: Male Wistar rats were subjected to the induction of SAH by means of the endovascular filament method. Sham-animals underwent sham-surgery. Rats received IFN-β for four consecutive days starting at two hours after SAH induction. After seven days, lungs were analyzed for the expression of inflammatory markers. RESULTS: SAH induced the influx of neutrophils into the lung, and enhanced expression of the pulmonary adhesion molecules E-selectin, inter-cellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule (VCAM)-1 compared to sham-animals. In addition, SAH increased the expression of the chemokines macrophage inflammatory protein (MIP)-1α, MIP-2, and cytokine-induced neutrophil chemoattractant (CINC)-1 in the lung. Finally, tumor necrosis factor-α (TNF-α) was significantly increased in lungs from SAH-animals compared to sham-animals. IFN-β effectively abolished the SAH-induced expression of all pro-inflammatory mediators in the lung. CONCLUSIONS: IFN-β strongly reduces lung inflammation after experimental SAH and may therefore be an effective drug to prevent SAH-mediated lung injury

Prediction of hemorrhagic transformation after experimental ischemic stroke using MRI-based algorithms.

Estimation of hemorrhagic transformation (HT) risk is crucial for treatment decision-making after acute ischemic stroke. We aimed to determine the accuracy of multiparametric MRI-based predictive algorithms in calculating probability of HT after stroke. Spontaneously, hypertensive rats were subjected to embolic stroke and, after 3 h treated with tissue plasminogen activator (Group I: n = 6) or vehicle (Group II: n = 7). Brain MRI measurements of T2, T2*, diffusion, perfusion, and blood-brain barrier permeability were obtained at 2, 24, and 168 h post-stroke. Generalized linear model and random forest (RF) predictive algorithms were developed to calculate the probability of HT and infarction from acute MRI data. Validation against seven-day outcome on MRI and histology revealed that highest accuracy of hemorrhage prediction was achieved with a RF-based model that included spatial brain features (Group I: area under the receiver-operating characteristic curve (AUC) = 0.85 ± 0.14; Group II: AUC = 0.89 ± 0.09), with significant improvement over perfusion- or permeability-based thresholding methods. However, overlap between predicted and actual tissue outcome was significantly lower for hemorrhage prediction models (maximum Dice's Similarity Index (DSI) = 0.20 ± 0.06) than for infarct prediction models (maximum DSI = 0.81 ± 0.06). Multiparametric MRI-based predictive algorithms enable early identification of post-ischemic tissue at risk of HT and may contribute to improved treatment decision-making after acute ischemic stroke.Multivariate analysis of psychological dat

Glutathione and antioxidant enzymes serve complementary roles in protecting activated hepatic stellate cells against hydrogen peroxide-induced cell death

Background: In chronic liver disease, hepatic stellate cells (HSCs) are activated, highly proliferative and produce excessive amounts of extracellular matrix, leading to liver fibrosis. Elevated levels of toxic reactive oxygen species (ROS) produced during chronic liver injury have been implicated in this activation process. Therefore, activated hepatic stellate cells need to harbor highly effective anti-oxidants to protect against the toxic effects of ROS.Aim: To investigate the protective mechanisms of activated HSCs against ROS-induced toxicity.Methods: Culture-activated rat HSCs were exposed to hydrogen peroxide. Necrosis and apoptosis were determined by Sytox Green or acridine orange staining, respectively. The hydrogen peroxide detoxifying enzymes catalase and glutathione-pefoxidase (GPx) were inhibited using 3-amino-1,2,4-triazole and mercaptosuccinic acid, respectively. The anti-oxidant glutathione was depleted by L-buthionine-sulfoximine and repleted with the GSH-analogue GSH-monoethylester (GSH-MEE).Results: Upon activation, HSCs increase their cellular glutathione content and GPx expression, while MnSOD (both at mRNA and protein level) and catalase (at the protein level, but not at the mRNA level) decreased. Hydrogen peroxide did not induce cell death in activated HSCs. Glutathione depletion increased the sensitivity of HSCs to hydrogen peroxide, resulting in 35% and 75% necrotic cells at 0.2 and 1 mmol/L hydrogen peroxide, respectively. The sensitizing effect was abolished by GSH-MEE. Inhibition of catalase or GPx significantly increased hydrogen peroxide-induced apoptosis, which was not reversed by GSH-MEE.Conclusion: Activated HSCs have increased ROS-detoxifying capacity compared to quiescent HSCs. Glutathione levels increase during HSC activation and protect against ROS-induced necrosis, whereas hydrogen peroxide-detoxifying enzymes protect against apoptotic cell death. (C) 2013 Elsevier B.V. All rights reserved.</p

Diagnostic labelling as determinant of antibiotic prescribing for acute respiratory tract episodes in general practice

<p>Abstract</p> <p>Background</p> <p>Next to other GP characteristics, diagnostic labelling (the proportion of acute respiratory tract (RT) episodes to be labelled as infections) probably contributes to a higher volume of antibiotic prescriptions for acute RT episodes. However, it is unknown whether there is an independent association between diagnostic labelling and the volume of prescribed antibiotics, or whether diagnostic labelling is associated with the number of presented acute RT episodes and consequently with the number of antibiotics prescribed per patient per year.</p> <p>Methods</p> <p>Data were used from the Second Dutch National Survey of General Practice (DNSGP-2) with 163 GPs from 85 Dutch practices, serving a population of 359,625 patients. Data over a 12 month period were analysed by means of multiple linear regression analysis. Main outcome measure was the volume of antibiotic prescriptions for acute RT episodes per 1,000 patients.</p> <p>Results</p> <p>The incidence was 236.9 acute RT episodes/1,000 patients. GPs labelled about 70% of acute RT episodes as infections, and antibiotics were prescribed in 41% of all acute RT episodes. A higher incidence of acute RT episodes (beta 0.67), a stronger inclination to label episodes as infections (beta 0.24), a stronger endorsement of the need of antibiotics in case of white spots in the throat (beta 0.11) and being male (beta 0.11) were independent determinants of the prescribed volume of antibiotics for acute RT episodes, whereas diagnostic labelling was not correlated with the incidence of acute RT episodes.</p> <p>Conclusion</p> <p>Diagnostic labelling is a relevant factor in GPs' antibiotic prescribing independent from the incidence of acute RT episodes. Therefore, quality assurance programs and postgraduate courses should emphasise to use evidence based prognostic criteria (e.g. chronic respiratory co-morbidity and old age) as an indication to prescribe antibiotics in stead of single inflammation signs or diagnostic labels.</p

How open science can support the 3Rs and improve animal research

Open science in its broadest sense can make better science and provide benefits to researchers. When applied to animal experimentation, it can prevent unnecessary use of animals, because knowledge and experiences about past animal experimentation are shared openly to be consulted and used by other researchers. By extension, open science can accelerate the much anticipated transition towards animal-free innovations or New Approach Methodologies (NAMs). The purpose of this paper is to bring together and further share the preparations and findings of a symposium held at Utrecht University on aspects of open science that researchers doing animal experiments can and should take into account to improve their research and benefit themselves. The paper offers a one-figure guideline for that purpose