DIFFERENTIATION OF AMYLOID FIBRIL PROTEINS IN TISSUE SECTIONS Two Simple and Reliable Histological Methods Applied to Fifty-one Cases of Systemic Amyloidosis

The potassium permanganate method and the unlabeled immunoperoxidase (PAP) method were applied for distinguishing different types of amyloid fibril proteins in conventionally fixed, paraffin-embedded tissue sections obtained from fifty-one autopsied cases of systemic amyloidosis and three control cases of well-analysed fibril proteins. All of the eighteen cases "sensitive" to permanganate treatment, whose amyloid deposits lost completely their affinity to Congo red and birefringence under polarized light, were shown to have AA antigenic determinants by the PAP method. Meanwhile, all of the remaining thirty-three "resistant" cases, where Congo red affinity and birefringence were retained at various degree even only in minimal areas, were negative for AA antigenicity. This indicated the feasibility of potassium permanganate method for the identification of AA protein based on this criterion of "sensitivity". Twenty-eight cases were classified as AA, Aγ, A_k or AA+[A_k] the remaining twenty-three cases were unclassified, and there were some discrepancies between the preliminary clinicopathological classification and the protein nature of the amyloid. It is important to differentiate the types of amyloid fibril protein of individual patients because the expedience of selective therapeutic approaches had been suggested. The two methods applied herein are handy and useful for this purpose.     

Distribution of mRNA for CCK-B receptor in the brain of Mastomys natalensis: abundant expression in telencephalic neurons

The distribution of chelecystokinin B (CCK-B) receptors in the Mastomys brain was studied using Northern blot analysis and in situ hybridization technique. By Northern blot analysis using³²P-labeled cDNA probe, the cortex had the highest hybridization signal of CCK-B receptor mRNA in the brain. The olfactory bulb and hippocampus showed a moderate level of signals. In situ hybridization using³⁵S-labeled cRNA probes revealed a wide and region-specific distribution of CCK-B receptor mRNA in the telencephalon. Throughout the cerebral cortex, labeled cells were found in all layers, with higher intensities in layers II, V and VI. Pyramidal cells of the layer II of the piriform cortex showed the highest level of signals in the brain. In the hippocampus, most of the pyramidal cells of the Ammon's horn were labeled, although labeled cells were not detected in other layers. Distinct signals were also detected in the various amygdaloid nuclei, caudate-putamen, reticular thalamic nucleus, hypothalamic ventromedial nucleus and inferior colliculus. This distribution pattern may further support the prominent existence of CCK-B receptors in the brain particularly in the telencephalon.     

Quantitative freeze-fracture electron microscopic study of muscle plasma membrane of experimental anoxic myopathy

The numerical change of intramembranous particles (IMP) and square arrays (SA) was investigated in the muscle plasma membrane after anoxia. The proximal portion of the hind limb of Wistar rats weighing 250-350 g was strongly tied with steel wire. The contralateral hind limb was served as control. After 3 and 6 h, the extensor digitorum longus (EDL) muscles of both control and anoxic groups were studied by freeze-fracture electron microscopy. The findings of anoxic EDL plasma membrane included the presence of band-like or patchy form particle free areas with the tendency to increase from 3 to 6 h and the preservation of SA even after 6 h of anoxia. However, the IMP and caveolae densities between control and anoxic groups were not statistically different. The group median densities of SA/micron2 of control P face were 4.9 with midrange of 2.2-9.7 and 7.1 with mid-range of 2.7-10.9 after 3 and 6 h; whereas those of anoxic P face were 6.0 with mid-range of 1.8-8.2 (P greater than 0.1) and 6.9 with mid-range of 3.3-13.5 (P greater than 0.1), respectively. These changes are quite different from those of muscle plasma membrane in Duchenne muscular dystrophy.     

Application of a Circular Polarizing Device to an Electronic Endoscope for the Purpose of Prevention of Catch-Light Phenomenon

Abstract: In recent years the electronic endoscope has been increasingly used by medical practitioners in Japan. However, it has been noted that the problem of too strong light refection, which, not only hampers the procedure but also causes eye exhaustion, at the same time making photographic or computerized image processing difficult, is more frequently experienced and is more serious in magnitude when compared with using a conventional fiberoptic endoscope (catch-light phenomenon). In order to ameliorate this problem the authors experimented with the use of circularly polarized light. The combined use of a circular polarizing device to the efferent light path and a filter which blocks certain types of Circularly polarized light to the afferent path has proved to be very effective in eliminating the incidence of catch-light troubles, thus making the endoscopic procedure smooth and efficient.     

An adult form of Gaucher's disease with a huge tumour formation of the right tibia

Summary A case of adult, chronic or non-neuropathic, Gaucher's disease is presented. Severe bony changes, particularly involving the lower limbs developed after a splenectomy had been carried out. Our patient had all the orthopaedic complications of Gaucher's disease. Further, a huge tumour was present in the right tibia caused by the proliferation of Gaucher cells. This feature may be unique but pseudotumour should be listed in the possible orthopaedic complications of Gaucher's disease. The patient was bedridden, but was able to use a wheelchair after his leg was amputated.

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Résumé Présentation d'un adulte atteint de maladie de Gaucher dans sa forme chronique, non neuropathique. De graves lésions osseuses, atteignant notamment les membres inférieurs sont apparues après splénectomie. Ce patient présentait toutes les complications orthopédiques de la maladie de Gaucher. En outre, il existait au niveau du tibia droit une énorme tumeur résultant de la prolifération des cellules de Gaucher. Cette observation est peut être unique mais on doit cependant savoir que les pseudo-tumeurs sont une des complications orthopédiques possible de la maladie de Gaucher. Le malade était grabataire, mais il a pu se déplacer à l'aide d'un fauteuil roulant après qu'il ait été amputé de sa jambe.

     

PDZ adaptor protein PDZK2 stimulates transport activity of organic cation/carnitine transporter OCTN2 by modulating cell surface expression.

A part of the organic cation transporter families (OCT3, OCTN1, and OCTN2) has recently been identified to physically interact with PDZ (PSD95, Dlg, and ZO1) domain-containing proteins, although the physiological relevance of such interaction has not yet been fully examined. Here we have examined the stimulatory effect of PDZK2 [also named NaPi-Cap2 and intestinal and kidney-enriched PDZ protein (IKEPP)] on those cation transporters. In HEK293 cells, coexpression with PDZK2 increased the uptake of carnitine by OCTN2 with minimal effect on its substrate recognition specificity, but not for transport activity of OCT3 or OCTN1. The stimulatory effect of PDZK2 on OCTN2 was compatible with an approximately 2 times increase in transport capacity and can be accounted for by the increase in cell surface expression of OCTN2. Coexpression of PDZK2 did not affect carnitine transport activity of OCTN2 with deletion of the last four amino acids, which were found to be important for the interaction, suggesting involvement of physical interaction of the two proteins in the increase of cell surface expression of OCTN2. In mouse kidney, colocalization of PDZK2 and OCTN2 occurred predominantly in the region that was close to, but not the same as, the surface of apical membranes where OCTN2 alone was observed, suggesting the existence of OCTN2 in the subapical compartment that interacts with PDZK2. The present data have thus proposed an "intracellular pool" for OCTN2 that may be relevant to the stabilization of cell surface expression of OCTN2, thereby increasing transport activity for carnitine.     

Ghrelin improves renal function in mice with ischemic acute renal failure

Growth hormone and IGF-1 have been suggested to have tissue-protective effects. Ghrelin is a stomach-derived growth hormone secretagogue. The effects of ghrelin on ischemia/reperfusion-induced renal failure in mice were examined. Ischemic acute renal failure was induced by bilateral renal artery clamping for 45 min and reperfusion for 24 h. Ghrelin (100 microg/kg mouse) or vehicle was injected subcutaneously six times before surgery and three times after surgery every 8 h. Twenty-four hours after reperfusion, the right kidney was isolated and perfused. Acetylcholine (ACh)- and adrenomedullin-induced endothelium-dependent vasorelaxation of renal vessels significantly improved in ghrelin-pretreated mice (%Delta renal perfusion pressure by 10(-7) M ACh -63.5 +/- 3.7 versus -41.2 +/- 5.5%; P < 0.05). This change was associated with significant increases of nitric oxide release in the kidneys of ghrelin-treated mice (10(-7) M ACh 35.5 +/- 5.8 versus 16.9 +/- 3.5 fmol/g kidney per min; P < 0.05). Serum concentration of urea nitrogen (53 +/- 7 versus 87 +/- 15 mg/dl; P < 0.05) and renal injury score were significantly lower in the ghrelin group (2.5 +/- 0.8 versus 5.3 +/- 1.5; P < 0.01). Tubular apoptotic index was significantly lower in the ghrelin group (5 +/- 5 versus 28 +/- 4; P < 0.05). Furthermore, the survival rate after the 60-min ischemic period was higher in the ghrelin group (80 versus 20%; P < 0.05). Ghrelin treatment significantly increased the serum level of IGF-1. However, such renal protective effects of ghrelin on ischemia/reperfusion injury were not observed in insulin receptor substrate-2 knockout mice. These results suggest that ghrelin may protect the kidneys from ischemia/reperfusion injury and that this effect is related to an improvement of endothelial function through an IGF-1-mediated pathway.