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At least 37 records · Page 2Linked to original sources
PubMed1993

Methodology of immunohistological detection of oestrogen receptor in human breast carcinoma in formalin-fixed, paraffin-embedded tissue: a comparison with frozen section methodology.

We describe a method of immunohistochemically assessing estrogen receptor status on routinely processed formalin-fixed tissue, using a commercially available monoclonal antibody (Abbott H222), with pronase predigestion of tissue sections and overnight antibody incubation. The staining was assessed using the H score system. A series of 94 cases of breast cancer were analysed and the results were compared with assessment by oestrogen receptor immunocytochemical assay performed on frozen section. Direct comparison of the paired sets of H scores obtained with frozen tissue and formalin-fixed tissue showed a highly significant correlation of 0.8 (P < 0.001) between the two methods of oestrogen receptor assessment. Chi-squared analysis using H score cut off points of 50 and 100 also showed a similar significant association (P < 0.001). We conclude that this oestrogen receptor method, applicable to formalin-fixed, paraffin-embedded tissue, gives accurate results on routinely fixed tissue and could be used as an alternative to other methods.

Adenocarcinoma↗
PubMed1993

Symposium: Dream research methodology: Methodological issues affecting the collection of dreams.

This article focuses attention on the perennial issue of home versus laboratory recording situations for the garnering of dream reports. Studies into the experimental control over procedures for both waking and interviewing are reviewed. Against this background, an experiment into the relationship between REM/NREM sleep and visual imagery is reported. We found that, having corrected for total word count, visual imagery still made an independent contribution to REM reports. This finding is evaluated in the light of differential cognitive mechanisms underlying dream formation during sleep.

Journal Article↗
PubMedDate not supplied

Methodological issues in linkage analyses for psychiatric disorders: secular trends, assortative mating, bilineal pedigrees. Report of the MacArthur Foundation Network I Task Force on Methodological Issues.

A Task Force was assembled to address three data problems in genetic linkage analyses: (1) a secular trend, e.g. cohort effect; (2) positive assortative mating, and (3) bilineal pedigrees. All are cited as reasons for failure to replicate genetic linkage reports. However, we knew of no work demonstrating that these factors could invalidate or bias linkage analyses, nor that they were complications (e.g., variable age of onset). The Task Force concluded that these factors can reduce the power of linkage analyses and result in bias in the estimate of the recombination frequency due to the fact that they represent 'noise' in the system. There was little evidence that the three factors would invalidate a linkage analysis or be directly responsible for negating a linkage finding.

Cohort Effect↗
PubMed1999

Transatlantic Conference on Clinical Trial Guidelines in Peripheral Arterial Disease: clinical trial methodology. Basel PAD Clinical Trial Methodology Group.

Guidelines for the clinical development of drugs in peripheral arterial disease (PAD) have been issued by the Food and Drug Administration for the United States and by the regulatory agency of the European Union for Europe. With increasing globalization, transatlantic cooperation in drug research and development is essential for the future and would be substantially facilitated by the existence of transatlantic guidelines. A conference was held in Basel, Switzerland, in November 1997 to discuss the scientific background of the existing guidelines on the basis of published evidence and the extensive knowledge of clinical investigators and experienced regulators. The meeting was attended by 52 invited experts from the United States and Europe, as well as by representatives from the 2 regulatory authorities. The main conclusions from the meeting are presented and may serve as a reference for the future development of transatlantic guidelines for the evaluation of pharmacotherapy in PAD.

Clinical Trials as Topic↗
PubMed1998

13th meeting of the Scientific Group on Methodologies for the Safety Evaluation of Chemicals (SGOMSEC): alternative testing methodologies and conceptual issues.

Substantial world-wide resources are being committed to develop improved toxicological testing methods that will contribute to better protection of human health and the environment. The development of new methods is intrinsically driven by new knowledge emanating from fundamental research in toxicology, carcinogenesis, molecular biology, biochemistry, computer sciences, and a host of other disciplines. Critical evaluations and strong scientific consensus are essential to facilitate adoption of alternative methods for use in the safety assessment of drugs, chemicals, and other environmental factors. Recommendations to hasten the development of new alternative methods included increasing emphasis on the development of mechanism-based methods, increasing fundamental toxicological research, increasing training on the use of alternative methods, integrating accepted alternative methods into toxicity assessment, internationally harmonizating chemical toxicity classification schemes, and increasing international cooperation to develop, validate, and gain acceptance of alternative methods.

Animal Testing Alternatives↗
PubMed1998

13th Meeting of the Scientific Group on Methodologies for the Safety Evaluation of Chemicals (SGOMSEC): alternative testing methodologies for organ toxicity.

In the past decade in vitro tests have been developed that represent a range of anatomic structure from perfused whole organs to subcellular fractions. To assess the use of in vitro tests for toxicity testing, we describe and evaluate the current status of organotypic cultures for the major target organs of toxic agents. This includes liver, kidney, neural tissue, the hematopoietic system, the immune system, reproductive organs, and the endocrine system. The second part of this report reviews the application of in vitro culture systems to organ specific toxicity and evaluates the application of these systems both in industry for safety assessment and in government for regulatory purposes. Members of the working group (WG) felt that access to high-quality human material is essential for better use of in vitro organ and tissue cultures in the risk assessment process. Therefore, research should focus on improving culture techniques that will allow better preservation of human material. The WG felt that it is also important to develop and make available relevant reference compounds for toxicity assessment in each organ system, to organize and make available via the Internet complete in vivo toxicity data, including human data, containing dose, end points, and toxicokinetics. The WG also recommended that research should be supported to identify and to validate biological end points for target organ toxicity to be used in alternative toxicity testing strategies.

Animal Testing Alternatives↗
PubMed1998

13th Meeting of the Scientific Group on Methodologies for the Safety Evaluation of Chemicals (SGOMSEC): alternative testing methodologies for ecotoxicity.

There is growing public pressure to minimize the use of vertebrates in ecotoxicity testing; therefore, effective alternatives to toxicity tests causing suffering are being sought. This report discusses alternatives and differs in some respects from the reports of the other three groups because the primary concern is with harmful effects of chemicals at the level of population and above rather than with harmful effects upon individuals. It is concluded that progress toward the objective of minimizing testing that causes suffering would be served by the following initiatives--a clearer definition of goals and strategies when undertaking testing procedures; development of alternative assays, including in vitro test systems, that are based on new technology; development of nondestructive assays for vertebrates (e.g., biomarkers) that do not cause suffering; selection of most appropriate species, strains, and developmental stages for testing procedures (but no additional species for basic testing); better integrated and more flexible testing procedures incorporating biomarker responses, ecophysiological concepts, and ecological end points (progress in this direction depends upon expert judgment). In general, testing procedures could be made more realistic, taking into account problems with mixtures, and with volatile or insoluble chemicals.

Animal Testing Alternatives↗
PubMed1990

[Methodology and diagnostic potentialities of macro-EMG. I. Methodology].

Macro-EMG records electrical activity from the whole motor unit (MU) as a parameter of its size. The main component of the recording device is a modified single fiber or concentric needle electrode. Different sized uptake areas allow to record with different selectivities from the MU. The teflon insulated shaft surface allows to record with a defined large blank area unselectively macro-signals from the muscle. The conceptual ideas to use a concentric needle in addition to the single fibre electrode is to simplify the trigger-potential recording, which needs to be selective within the MU. In both instances the EMG apparatus has to provide two channels, one for the trigger and the second for an averaging device to record the macro-EMG. The different techniques use the single fiber or concentric EMG-potential as a trigger to average the associated macro-potential from the raw signals. The electrodes different design allow the whole single-fiber-needle to lie within the MU territory whereas the MU is only touched by the concentric needles tip. This implies different recording situations and results. Anatomically macro-EMG size is varied by the recording site of the muscle. The signal is greater close to the endplate zone and declines to stable values about 20 mm apart. For quantitative measurements within a muscle 20 different potentials have to be evaluated for median amplitude, duration and area.

Electromyography↗