State of the art in pig embryo transfer

Embryo transfer in pigs has required surgical procedures in both donors and recipients. Over the last decade, procedures have been developed for transferring embryos by endoscopic or nonsurgical (transcervical) procedures. The feasibility of these procedures for practical application and the latest results of these new approaches are compared here. Factors affecting the current results and obstacles to be overcome in the near future are also discussed. Finally, some relevant embryo collection procedures and applications are briefly summarized.     

The use of modified sutures in plastic surgery

SUMMARY: Modified sutures have been developed and are currently being used in closed and open facial rejuvenation procedures. In addition, these sutures have applications in body contouring procedures and wound closure. The indications and efficacy of these sutures continue to evolve.     

Histochemistry of carbohydrates as performed by physical development procedures

Summary The histochemistry of carbohydrates demonstrated by means of physical development procedures has been reviewed in terms of the use and reliability of the procedures, physical developers, practice of the procedures, a fundamental series of light and electron microscopic methods and certain other promising aspects of this area of histochemistry. A line of fundamental light- and electron-microscopic histochemical methods for carbohydrates using physical development procedures such as periodic acid thiocarbohydrazide-silver protein-physical development (PA-TCH-SP-PD), high- or low-iron diamine (HID or LID)-TCH-SP-PD and lectin-gold (LT-G)-PD and related methods has been found to be more efficient, compared with those without physical development procedures. Since a series of other promising histochemical methods for carbohydrates using physical development procedures have been derived or are now being introduced, these procedures could be regarded as an unusually potent vehicle for effectively advancing carbohydrate histochemistry in both light and electron microscopy.     

Applying the "3 Rs": training course in surgical techniques

As the use of surgical procedures in rodents becomes increasingly common in biomedical research, institutions face the challenge of ensuring that personnel are properly trained to perform these procedures. The author describes a microsurgery training course in use at Columbia University.     

Standardized staining methods: Feulgen-Rossenbeck reaction for desoxyribonucleic acid and periodic acid-Schiff (PAS) procedure

A project group working under the European Confederation of Laboratory Medicine (ECLM) presents recommendations for standardized procedures for the Feulgen-Rossenbeck-Schiff and the periodic acid-Schiff (PAS) reactions on cytological and histological material. The advantages and disadvantages of such standardized procedures are presented here in a preamble. Both users and manufacturers are encouraged to give their opinions with a view to achieving consensus on these procedures and on how further work on these lines may proceed.     

Standardized staining methods: Feulgen-Rossenbeck reaction for desoxyribonucleic acid and periodic acid-Schiff (PAS) procedure

A project group working under the European Confederation of Laboratory Medicine (ECLM) presents recommendations for standardized procedures for the Feulgen-Rossenbeck-Schiff and the periodic acid-Schiff (PAS) reactions on cytological and histological material. The advantages and disadvantages of such standardized procedures are presented here in a preamble. Both users and manufacturers are encouraged to give their opinions with a view to achieving consensus on these procedures and on how further work on these lines may proceed.     

Mechanized techniques for the selective extraction of enzymes from plant epidermal glands

Many plant products are biosynthesized and accumulated in epidermal glands. For investigations on the metabolism of these compounds it is most convenient to obtain cell-free preparations enriched in gland contents. Two simple mechanized procedures have been developed for gently abrading the plant surface in order to efficiently extract glandular enzymes in high purity. These methods allow rapid processing of large quantities of plant material and yield extracts largely uncontaminated with materials from underlying tissue. The use of these procedures for isolating several enzymes of terpenoid metabolism is described. These techniques work especially well for microsomal enzymes and may be useful not only for enzymes found in epidermal glands but also for other enzymes localized in or near the epidermis. With simple modification, these procedures can be adapted for use with a variety of different types of plant tissues.     

Tests of Homogeneity for the Relative Difference between Strata under Inverse Sampling

This paper develops the exact and asymptotic test procedures for detecting whether the relative difference of a given disease between exposure and non-exposure to a risk factor varies between strata under inverse sampling. This paper applies Monte Carlo Simulation to evaluate the performance of the proposed asymptotic test procedures and further demonstrates that these asymptotic procedures can be useful in many situations, especially when either the number of index subjects is large or the probability of possessing the underlying disease is small.     

Surgical Models of Gastroesophageal Reflux with Mice

Multiple surgical procedures have been reported to induce gastroesophageal reflux in animals. Herein, we report three surgical models with mice aiming to induce reflux of gastric contents, duodenal contents or mixed contents. Surgical procedures and general principles have been described in detail. A researcher with surgical experience should be able to grasp the technique after a short period of practice. After surgery, most mice can survive and develop reflux esophagitis similar to that in humans. However, it should be noted that histological differences between mouse and human esophagus are the inherent limitations of these surgical models. If used for research on Barrett’s esophagus and adenocarcinoma, these procedures may need to be combined with genetic modifications.     

Fluorometric analysis of epinephrine and norepinephrine.

A modification of the classic trihydroxyindole method for the fluorometric estimation of epinephrine and norepinephrine is presented. Assay procedures for each catecholamine were separately optimized, significantly increasing the sensitivity and specificity of the procedures. Methodology has been simplified through the use of intersolution calibration, making this assay suitable for use in research or clinical laboratories. Performance of both epinephrine and norepinephrine assays are possible on 1 ml of deproteinated plasma or urine using these procedures.     

Psychiatric Treatment: General Implications and Lessons From Recent Court Decisions in California

The California legislature enacted tight constraints on the use of psychosurgery and electroconvulsive therapy in 1974. In April 1976 a State Court of Appeals declared part of the law to be unconstitutional. In doing so, the court enunciated several principles for regulating medical procedures. It affirmed the inherent police powers which permit the state to safeguard the public, especially incompetent, involuntary or confined persons, with respect to intrusive and hazardous medical procedures and to procedures which affect thought or feeling. Although limited to legislation concerning two psychiatric procedures, the court''s decision, and subsequently enacted legislation governing these procedures, has implications for other medical procedures and for other parts of the nation.     

Testing equality of survival functions based on both paired and unpaired censored data

We introduce two test procedures for comparing two survival distributions on the basis of randomly right-censored data consisting of both paired and unpaired observations. Our procedures are based on generalizations of a pooled rank test statistic previously proposed for uncensored data. One generalization adapts the Prentice-Wilcoxon score, while the other adapts the Akritas score. The use of these particular scoring systems in pooled rank tests with randomly right-censored paired data has been advocated by several researchers. Our test procedures utilize the permutation distributions of the test statistics based on a novel manner of permuting the scores. Permutation versions of tests for right-censored paired data and for two independent right-censored samples that use the proposed scoring systems are obtained as special cases of our test procedures. Simulation results show that our test procedures have high power for detecting scale and location shifts in exponential and log-logistic distributions for the survival times. We also demonstrate the advantages of our test procedures in terms of utilizing randomly occurring unpaired observations that are discarded in test procedures for paired data. The tests are applied to skin graft data previously reported elsewhere.     

Multivariate classification of animal communication signals: A simulation-based comparison of alternative signal processing procedures using electric fishes

Evolutionary studies of communication can benefit from classification procedures that allow individual animals to be assigned to groups (e.g. species) on the basis of high-dimension data representing their signals. Prior to classification, signals are usually transformed by a signal processing procedure into structural features. Applications of these signal processing procedures to animal communication have been largely restricted to the manual or semi-automated identification of landmark features from graphical representations of signals. Nonetheless, theory predicts that automated time-frequency-based digital signal processing (DSP) procedures can represent signals more efficiently (using fewer features) than can landmark procedures or frequency-based DSP – allowing more accurate classification. Moreover, DSP procedures are objective in that they require little previous knowledge of signal diversity, and are relatively free from potentially ungrounded assumptions of cross-taxon homology. Using a model data set of electric organ discharge waveforms from five sympatric species of the electric fish Gymnotus, we adopted an exhaustive simulation approach to investigate the classificatory performance of different signal processing procedures. We considered a landmark procedure, a frequency-based DSP procedure (the fast Fourier transform), and two kinds of time-frequency-based DSP procedures (a short-time Fourier transform, and several implementations of the discrete wavelet transform -DWT). The features derived from each of these signal processing procedures were then subjected to dimension reduction procedures to separate those features which permit the most effective discrimination among groups of signalers. We considered four alternative dimension reduction methods. Finally, each combination of reduced data was submitted to classification by linear discriminant analysis. Our results support theoretical predictions that time-frequency DSP procedures (especially DWT) permit more efficient discrimination of groups. The performance of signal processing was found to depend largely upon the dimension reduction procedure employed, and upon the number of resulting features. Because the best combinations of procedures are dataset-dependent and difficult to predict, we conclude that simulations of the kind described here, or at least simplified versions of them, should be routinely executed before classification of animal signals - especially unfamiliar ones.     

Determination of 4-aminopyridine in plasma

Gas-liquid chromatographic procedures for the determination of 4-aminopyridine in human and animal plasma are reported. The procedures involve the addition of an internal standard 3-methyl-4-aminopyridine to plasma followed by extraction into methylene chloride/isopropranol under alkaline conditions. The isolated amines are converted to their pentafluoropropionyl or monochlorodifluoracetyl derivatives and are quantified after chromatographic separation using either electron-capture or nitrogen-phosphorus detectors. The sensitivity of these procedures is such that nanogram amounts of 4-aminopyridine can be readily determined.     

Isolation of intact mesophyll cells and their protoplasts from higher plants

Eighteen herbaceous species of angiosperms were tested for theisolation of mesophyll cells and their protoplasts by applyingenzymatic procedures originally developed for tobacco. Intactmesophyll cells and their protoplasts were obtained from a varietyof plants, indicating the general applicability of these procedures. (Received May 17, 1969; )     

Fluorescent Staining Technique for Nucleoid Regions of Streptosporangium albidum and Streptosporangium brasiliense

Fluorescent staining procedures were developed for elucidating the nucleoid region in Streptosporangium albidum and Streptosporangium brasiliense. In these procedures, plugs of nutrient agar were inoculated with the microorganims and then covered with a sterile glass slide. The growing cells adhered to the surface of the slide and remained attached throughout the staining procedures. Two separate staining methods were utilized, one with bisbenzimid H33258 and the other with auramine O. Fluorescent microscopy revealed intensely stained nucleoid regions within mycelia, spores, and sporangia.     

Scientific procedures on living animals in Great Britain in 2003: the facts, figures and consequences

The statistics for animal procedures performed in 2003 were recently released by the Home Office. They indicate that, for the second year running, there was a significant increase in the number of laboratory animal procedures undertaken in Great Britain. The species and genera used, the numbers of toxicology and non-toxicology procedures, and the overall trends, are described. The implications of these latest statistics are discussed with reference to key areas of interest and to the impact of existing regulations and pending legislative reforms.     

Quantitative Histology Using Confocal Microscopy: Implementation of Unbiased Stereology Procedures

Direct, two-dimensional counting or measuring of cells as they appear in histological sections is subject to a number of artifacts that can lead to erroneous conclusions about changes in cellular populations. Numerous correction procedures devised to compensate for these artifacts are collectively termed model-based stereology due to their reliance on a model of cell geometry for correction formulas. These corrections are valid only to the degree that the geometric model reflects cellular morphology. In addition, there are requirements for population homogeneity that are often not met in biological material. The development of design-based stereology provides a way to directly count or measure cells in three dimensions, avoiding errors (biases) and the need for assumptions regarding cell size, shape, and orientation to be validated. On this basis, these procedures are described as unbiased stereology. The recent commercial availability of semiautomated stereology systems has substantially reduced the effort and experimenter error (bias) associated with the use of design-based stereology. The optical resolution of confocal microscopy and the ability to collect registered series of focal planes is ideally suited for the three-dimensional sampling of design-based stereology. Unfortunately, stereological procedures are not available in any confocal microscope software and it is up to the user to implement these procedures. Strategies and illustrations of approaches to implementing stereological procedures on a confocal microscope are presented. Where possible, particular design issues are discussed and solutions suggested. With user requests, future generations of confocal software may integrate collection of confocal images with the implementation of design-based stereology.     

Unintended Harm and Benefit of the Implantable Defibrillator in an Unfortunate 19-Year-Old Male: Featuring a Sequence of Rare Life-threatening Complications of Cardiac Procedures

All procedures have inherent risk. Our patient endured a sequence of rare life-threatening complications from commonly preformed procedures. The sequence of these complications was; large pericardial effusion post implantable cardioverter-defibrillator (ICD) implantation with echocardiographic signs of tamponade, left main narrowing post radiofrequency ablation, and late stent thrombosis post coronary intervention with a bare metal stent. All these occurred to one unfortunate young man. Furthermore, our patient demonstrated an unintended benefit of ICD which saved his life.     

Exact Tests for Comparing Two Paired Proportions with Incomplete Data

Various asymptotic test procedures have been developed previously for testing the equality of two binomial proportions with partially incomplete paired data. Test procedures that discard incomplete observations have been shown to be less powerful than those procedures that utilize all available observations. On the other hand, asymptotic test procedures that utilize all available observations may not be reliable in small‐sample problems or sparse data structures. In this article, unconditional exact test procedures are proposed for testing the equality of two paired binomial proportions with partially incomplete paired data under a random mechanism. The proposed unconditional exact test methods are illustrated with real data from a neurological study. Empirical studies are conducted to investigate the performance of these and other test procedures with respect to size and power. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)