Electron microscopic study of the prenatal development of the thoracic aorta in the rat

Prenatal development of the thoracic aorta of the rat during the period ranging from gestational days 12 to 21 was examined by transmission electron microscopic and morphometric studies. The process of wall formation occurred in four major phases. At phase I (gestational day 12), the dorsal aorta consists of an endothelium and loosely surrounding mesenchymal cells. Collagen fibrils and fine filamentous materials are sparsely present in the intercellular space. At phase II (days 13 to 16), the mesenchymal cells begin to differentiate to myoblasts, which have small clusters of myofilaments with dense bodies, rough endoplasmic reticulum, and a discontinuous basal lamina. The differentiating cells form a few compact cell layers around the endothelium. Elastic fibers first occur sparsely in juxtacellular spaces at days 13–14. The thickness of the aorta increases rapidly from 1–3 layers of cells at day 13 to 5–8 layers at day 17, leading to a maximum of 5–9 cell layers at day 20. The differentiation of myoblasts and elastogenesis are initiated in the inner layers, and later progress toward the outer layer of the aortic wall. At phase III (days 17 to 19), the myoblasts continue to develop into typical smooth muscle cells, and elastic fibers rapidly increase in both size and number. At phase IV (day 20 and later), smooth muscle cells have well-developed myofilaments in the cell periphery, and rough endoplasmic reticulum and other organelles tend to accumulate in the apical portion of the cytoplasm. Elastic laminae appear in a few inner layers of the aortic wall.     

Evidence for a link between mechanical and electrical alternans in acutely ischaemic myocardium of anaesthetized dogs.

In order to examine the relation between mechanical alternans and associated electrical alternans during acute myocardial ischaemia, we determined the effect of a ventricular premature beat and calcium antagonists on mechanical and electrical alternans during acute coronary occlusion in anaesthetized dogs. Isometric contractions and unipolar electrocardiograms were recorded from ischaemic myocardium. During coronary occlusion, mechanical alternans was accompanied by electrical alternans, which was an alternate change in the ST segment elevation, i.e. the higher ST and the lower ST. Electrical alternans was frequently discordant and in some cases accompanied by discordant mechanical alternans. Both discordant electrical and mechanical alternans became concordant and were potentiated after the ventricular premature beat. In all cases, concordant mechanical alternans was accompanied by concordant electrical alternans and vice versa. In this situation, the higher and the lower ST corresponded to the larger and the smaller contractions respectively. Thus, a fixed correspondence was observed between mechanical and electrical alternans. A fixed correspondence was also observed between mechanical alternans and the variation in the time taken for repolarization of the monophasic action potential. Verapamil and diltiazem inhibited both electrical and mechanical alternans. The present results support the idea that a common mechanism, such as a beat-to-beat cycle of the transmembrane and intracellular movement of calcium ions, may play a role in the mechanisms of electrical and mechanical alternans.     

BRONCHIOLO-ALVEOLAR ADENOCARCINOMA WITH MULTIPLE CYSTS

An autopsy case of bronchiolo-alveolar adenocarcinoma in the lung is reported. The patient is a 70-year-old male who complained of severe cough with 500–600 ml watery sputum a day, loss of weight, and general fatigue. Autopsy revealed numerous whitish tumors in various sizes with multiple cysts in both lungs, with no metastasis being found in any other organs. Histological findings identified the tumor as a bronchiolo-alveolar adenocarcinoma originating from the lungs. Electron-microscopic findings showed that the tumor cells were covered by prominent microvilli, and contained abundant irregulary-shaped cytoplasmic vacuoles suggestive of mucin.     

Four cases of wheat-dependent exercise-induced anaphylaxis with negative gluten cap-rast score]

BACKGROUND: Either omega-5 gliadin or high molecular weight glutenin is known to be a major allergen in wheat-dependent exercise-induced anaphylaxis (WDEIA). It is generally considered that gluten specific IgE score is more reliable than that of wheat specific IgE score for the diagnosis of WDEIA. Our aim was to verify the significance of gluten specific IgE in the diagnosis of WDEIA. METHODS: We evaluated the result of gluten CAP-RAST score and omega-5 gliadin specific IgE score on four WDEIA patients who visited our hospital during the years 2004 and 2005, whose diagnosis were onfirmed by prick tests, immunoblot tests and provocation tests. RESULTS: Contrary to our expectations, all four patients showed negative gluten CAP-RAST scores, however all patient's omega-5 gliadin specific IgE scores were positive. CONCLUSION: Our results suggest that gluten specific CAP-RAST score is unreliable in the diagnosis of WDEIA. On the other hand omega-5 gliadin specific IgE score is possibly a better candidate as a diagnostic tool for WDEIA.     

Koebner phenomenon in lupus erythematosus with special consideration of clinical findings

The isomorphic response of Koebner can be observed not only in psoriasis, but also in other diseases, such as lichen planus and some systemic diseases including LE (lupus erythematosus) or sarcoidosis. Several clinical findings in LE skin were presented and discussed in this review. The mutually-interactive-, negative-, and internal-Koebner phenomena were introduced and discussed with some speculative views. Many forms of environmental stress on the skin were reported as provocating factors of the Koebner phenomenon, including trauma, scratching, UV-exposure, and various types of dermatitis. Clinical observations of the nature, localization, and movement of lesions should be carefully made. The pathophysiology of the Koebner phenomenon may be classified into two steps. A first non-specific inflammatory step and a second disease-specific step. The inflammatory products released from the first step would be targeted in the second step. In the first step, there could be many substances including cytokines, stress proteins, adhesion molecules, or autoantigens translocated from intra-cellular areas. In the second step after latent periods, there may be disease-specific reactions, including ones by T-cells, B-cells, autoantibodies, and immune deposits, under the restriction of genetic backgrounds. The Koebner phenomenon may prove useful in understanding the pathophysiology of diseases of unknown origin.     

JCCLS phlebotomy standards

In 2004, the Japanese Committee of Clinical Laboratory Standards (JCCLS) published a standard phlebotomy guideline, which not only ensures the safety of the patients and phlebotomists but is adopted to the healthcare setting in Japan. This phlebotomy standard is also essential for the standardization of clinical laboratory tests. This guideline was completed on the basis of current phlebotomy procedures widely in use in Japan using phlebotomy standards in the USA as references, while reconsidering their scientific reasoning as far as possible. At the same time, factors such as practicality and cost benefit were taken into account. The content of the guideline includes necessary facilities and equipment, a step by step safe but practical venipuncture procedure, an explanation of the individual steps, and other supplementary information such as alternative methods. The first edition, published as tentative guideline, is planned to be revised after a set period of time based on the comments and suggestions from a wide range of people concerned, so that it can be published as an approved guideline.