In situ preparation of colloidal iron by microwave irradiation for transmission electron microscopy.

We attempted to prepare colloidal iron within tissues by means of microwave irradiation. Mouse tissue blocks were fixed with a mixture of paraformaldehyde and ferric chloride in a cacodylate buffer, immersed in a cacodylate buffered ferric chloride solution, and irradiated in a microwave processor. Colloidal iron was prepared within tissues or cells, and was observed in the form of electron dense fine granules (1-2 nm in diameter) by transmission electron microscopy. Collagen fibrils in the connective tissue showed colloidal iron deposition at regular periodical intervals. Cells in the splenic tissue showed that fine colloidal granules were deposited on the ribosomes but not on the nuclear chromatin. This finding suggests that ferric ions could not diffuse into the nucleus, which was surrounded by the nuclear envelope. The podocyte processes of the renal glomerulus were stained diffusedly. Though this microwave in situ colloidal iron preparation method has some limitations, it is convenient for use in biomedical specimen preparation in transmission electron microscopy.</p

Architecture of the Subendothelial Elastic Fibers of Small Blood Vessels and Variations in Vascular Type and Size

Most blood vessels contain elastin that provides the vessels with the resilience and flexibility necessary to control hemodynamics. Pathophysiological hemodynamic changes affect the remodeling of elastic components, but little is known about their structural properties. The present study was designed to elucidate, in detail, the three-dimensional (3D) architecture of delicate elastic fibers in small vessels, and to reveal their architectural pattern in a rat model. The fine vascular elastic components were observed by a newly developed scanning electron microscopy technique using a formic acid digestion with vascular casts. This method successfully visualized the 3D architecture of elastic fibers in small blood vessels, even arterioles and venules. The subendothelial elastic fibers in such small vessels assemble into a sheet of meshwork running longitudinally, while larger vessels have a higher density of mesh and thicker mesh fibers. The quantitative analysis revealed that arterioles had a wider range of mesh density than venules; the ratio of density to vessel size was higher than that in venules. The new method was useful for evaluating the subendothelial elastic fibers of small vessels and for demonstrating differences in the architecture of different types of vessels

Effects of adenoviral-mediated hepatocyte growth factor on liver regeneration after massive hepatectomy in rats

Resection is the only curative treatment for liver metastasis of colorectal cancers. Despite the supreme regenerative potential of the liver, major hepatectomy sometimes leads to liver failure, and the limitation of resectable liver volumes makes advanced tumors inoperable. This study was attempted to promote liver regeneration using hepatocyte growth factor (HGF) gene transfection by venous-administered adenovirus and to improve the survival of rats after massive hepatectomy. The adenovirus that encodes HGF was administered to rats before 85%-hepatectomy. The administration of HGF gene improved the survival of rats after massive hepatectomy, while the administration of control adenovirus deteriorated their survival. Gene transfection of HGF showed up-regulation of serum HGF, stimulation of hepatocellular proliferation and rapid liver regeneration. Moreover, HGF administration reduced apoptosis of hepatocytes. The administration of HGF gene prevented liver dysfunction after major hepatectomy and may be a new assist for surgery.</p

Expression of Superoxide Dismutase in Basal Cell Carcinoma

There have been no studies of the expression of superoxide dismutase(SOD) at the mRNA and protein level in skin cancers. Northern blot analysis and enzyme-linked immunosorbent assay (ELISA) were performed in order to analyze the expression of Cu, Zn-SOD and Mn-SOD in basal cell carcinomas (BCC) and normal skin (NS). The expression of Mn-SOD mRNA and protein was significantly higher in BCC than in NS. The expression of Cu,Zn-SOD, however, was high in BCC at the mRNA level, but not at the protein level. These results suggest that an increase in the expression of Mn-SOD relates to the development of BCCs

Two siblings with vitamin B6-nonresponsive cystathionine β-synthase deficiency and differing blood methionine levels during the neonatal period

We present two siblings with vitamin B6-nonresponsive homocystinuria due to a deficiency of cystathionine β-synthase who had different levels of methionine in the blood during the neonatal period, even though they had the same genetic defect. One of them was missed in the screening of newborns for homocystinuria. Special care should be taken in screening neonates for homocystinuria using the blood level of methionine

Measurement and Analysis of Electromyography for Sequential Mastication

　In the palatability of food, texture is a major factor of food quality. The physical shear force value of meat has been measured. However, quantitative relationship and characterization between shear force value and tenderness as a sensory perception has not been clear. Therefore, a computer system was developed to analyze and to measure the electromyography (EMG) for mastication. 　The integral EMG values were almost constant by sequential mastication up to five times. The average of integral EMG values were 63.6 mV with tender meat of pork fillet and 153.8 mV with firm meat of beef round, giving a ratio of 2.4 times. The shear force values of similar samples were 2,300 g and 8,300 g each, and the ratio was 3.6 times. Sensory texture of the subjective feeling was 3ﾝ4 times that corresponded with the shear force value. The integral EMG value could be thought to compress the amount of texture sense. 　The integral EMG varied greatly in food, and showed lower value in order of boiled fish surimi, steamed fish paste, pork sausage, konnyaku (devil’s tongue), pork fillet, beef loin, pork ham portion, roast beef, pork loin and beef round. Generally this order reflected the sensory texture of chewing. The deviation of the integral EMG value was smaller than expected, so it has a definite possibility for practical use