AN ELECTRON MICROSCOPIC STUDY ON THE RETICULOENDOTHELIAL CELLS IN THE LYMPH NODES

In an attempt to clarify the cytological characteristics of the RES cells in the lymph nodes and their embryological correlations, lymph nodes and lymph node anlages of germ-free rats, nude mice, and human fetuses were light and electron microscopically examined. On the basis of differences of intracellular organelles, their behaviors for reticulum fibers and of endogenous peroxidatic activity, histiocytes should be reasonably distinguished from the cells conventionally called reticulum cells. Reticulum cells and histiocytes respectively are destined to differentiate in different directions from the early stage of development of the lymph node anlage. Sinus endothelial cells are ontogenetically originated and differentiated from the endothelial lining cells of lymphatic vessels. Primitive reticular cells are differentiated into mature reticulum cells in the lymph nodes, they transform into the lympho-reticular cells, further into lymphoblasts, and finally develop into medium-sized lymphocytes.     

Identification of cryptochrome DASH from vertebrates

A new type of cryptochrome, CRY-DASH, has been recently identified. The CRY-DASH proteins constitute the fifth subfamily of the photolyase/cryptochrome family. CRY-DASHs have been identified from Synechocystis sp. PCC 6803, Vibrio cholerae, and Arabidopsis thaliana. The Synechocystis CRY-DASH was the first cryptochrome identified from bacteria, and its biochemical features and tertiary structure have been extensively investigated. To determine how broadly the subfamily is distributed within living organisms, we searched for new CRY-DASH candidates within several databases. We found five sequences as new CRY-DASH candidates, which are derived from four marine bacteria and Neurospora crassa. We also found many CRY-DASH candidates from the EST databases, which included sequences from fish and amphibians. We cloned and sequenced the cDNAs of the zebrafish and Xenopus laevis candidates, based on the EST sequences. The proteins encoded by the two genes were purified and characterized. Both proteins contained folate and flavin cofactors, and have a weak DNA photolyase activity. A phylogenetic analysis revealed that the seven candidates actually belong to the new type of cryptochrome subfamily. This is the first report of the CRY-DASH members from vertebrates and fungi.     

Rapid identification of metallothionein isoforms in liver cytosol fraction by capillary zone electrophoresis using EDTA

Identification of metallothionein (MT) isoforms on capillary zone electrophoresis (CZE) analysis was studied using a linear polyacrylamide-coated capillary at pH 7.4 and EDTA. The CZE system was able to separate standard (purified and commercially available) MT specimens into their isoforms within 10 min. The peaks of MT-1 and MT-2 isoforms disappeared on addition of EDTA to the specimen, and the disappearance was shown to be time-dependent and dose-dependent, although the reason why the peaks decreased is still unclear. A heat-treated cytosol fraction prepared from Zn-injected mouse liver showed many major and minor peaks on CZE analysis. Two major peaks were identified to be MT-1 and MT-2, respectively, by co-injection with the purified MT isoforms. When EDTA was added to the cytosol fraction, the two major peaks, MT-1 and MT-2, and three other minor peaks disappeared time-dependently. Therefore, each MT isoform in the cytosol fraction can be identified by the addition of EDTA, also the peaks are identified by the corresponding migration times of purified MTs. Unknown substances like MT sub-isoforms may also be detected, although this question warrants clarification. From these results, it was concluded that the addition of EDTA is useful for identification of MT isoforms in cytosol fractions on CZE analysis.     

Role of ventricular assist devices in the German heart allocation system

The Eurotransplant (ET) allocation algorithm, newly implemented in 2000, gives priority for heart transplantation (HTx) to patients with high urgency (HU) status, but now this status is rescinded upon ventricular assist device (VAD) implantation and only regained if severe complications occur during mechanical circulatory support (MCS). We studied the effects of this change on the patients in our institute who were waiting for HTx with MCS. The median duration of MCS until HTx in adult patients gradually increased from 3.1 months in 1994, reaching a peak of 16.7 months in 2000, and then gradually decreased to 6.0 months in 2003. Among the patients with VAD implantation as a bridge to HTx, two patients were on MCS for more than 1 year (the longest duration of MCS being 1.6 years) at the end of 1999, and this figure increased to nine patients and a maximum MCS duration of 3.7 years at the end of 2003. These data imply that the patients in whom a complication occurred in the early phase of MCS and who had overcome this complication underwent HTx early with HU status, and those who were stable during MCS waited a long time for HTx. Furthermore, the number of patients in the latter group is increasing. The new allocation algorithm imposes on patients with MCS waiting for HTx who are relatively young and free from complications and serious coexisting disease, very long-term MCS without an end to VAD bridging, which is almost equivalent to destination therapy. Part of this paper was presented at the 42nd JSAO Conference (Tokyo, October 5–7, 2004)     

Administration of interleukin -5 or -10 activates peritoneal B-1 cells and induces autoimmune hemolytic anemia in anti-erythrocyte autoantibody-transgenic mice

Activation mechanisms of B-1 (Ly-1 B) cells have been suggested to be different from those of conventional B cells. To assess the role of various interleukins (IL) in the activation of B-1 cells, we injected IL-4, IL-5 or IL-10 into nonanemic anti-red blood cells (RBC) autoantibody-transgenic mice, in which conventional B cells are clonally deleted but peritoneal B-1 cells persist without secreting Ig. Intraperitoneal or intramuscular injection of IL-5 or IL-10, but not IL-4, increased the number of antibody-producing peritoneal B-1 cells by four- to five-fold, resulting in increased anti-RBC serum autoantibody and induction of hemolytic anemia. These results suggest that IL-5 or IL-10 may play an important role in the terminal differentiation of B-1 cells into antibody-producing cells in vivo.     

The relationship of VEGF and PGE2 expression to extracellular matrix remodelling of the tenosynovium in the carpal tunnel syndrome

Tenosynovial thickening within the confined space of the carpal tunnel is thought to be the cause of the carpal tunnel syndrome (CTS). However, little is known about the pathological mechanism of tenosynovial thickening. In this study, the role of prostaglandin E(2) (PGE(2)) and vascular endothelial growth factor (VEGF) (two representative molecules that can induce oedema by increasing vascular permeability) was analysed in CTS by using immunohistochemistry and enzyme-linked immunosorptive assay (ELISA). Expression of these molecules was compared with the patients' clinical histories and a temporary increase in production of these molecules was found in cells within the vessels and synovial lining during the intermediate phase of the syndrome when the histology of the tenosynovium changes from oedematous to fibrotic. Statistical analysis clearly demonstrated that there is a close correlation between the expression of PGE(2) and VEGF. Furthermore, immunohistochemical analysis with anti-proliferating cell nuclear antigen (PCNA) revealed that the area with distinct VEGF expression closely matched the area where endothelial cells, vascular smooth muscle cells, and synovial lining cells proliferate. In contrast, despite marked alteration in the extracellular matrix (ECM) component of the tenosynovium, the fibroblasts responsible for most ECM framework production do not proliferate during any phase of CTS. Histological analysis demonstrated that angiogenesis takes place only during the intermediate phase. Since clusters of capillaries and arterioles are often surrounded by type III collagen-rich, disorganized, degenerate connective tissue, which contains fewer fibroblasts than normal, angiogenesis appears to take place as a part of a regenerative reaction that results in fibrosis. These findings strongly indicate that both PGE(2) and VEGF are expressed in the tenosynovium in CTS during the intermediate phase and induce the histological changes seen in the tenosynovium.     

HISTOLOGICAL AND IMMUNOHISTOCHEMICAL STUDIES ON SPONTANEOUS RENAL LESIONS OF PRAOMYS (MASTOMYS) NATALENSIS

A high incidence of renal lesions (120 of 164) was confirmed in Mastomys. As high as 86.4% of the tumor-bearing cases developed renal lesions, while 50.8% of animals without tumors were involved by such lesions. Glomerulonephritis was the most frequent with an incidence of 88.3% of the cases. An increase of the mesangial matrix was the initial form. Almost one-third of glomerulonephritis cases were complicated by pyelonephritis and hydronephrosis. Tumor-bearing cases had more advanced lesions in an average severity, although a half of them had only mild changes. Immunohistochemical studies revealed localization of globulins and beta 1C along the walls of the glomerular tufts suggesting deposition of immune complexes. Nodular homogenous deposits in close contact to the basement membrane were ultrastructurally evidenced in the glomeruli. A tiny adenoma was found in a male case with stomach tumor. ACTA PATH. JAP. 20: 311 - 325, 1970.     

Voltammetry in unanesthetized rat: Increases of striatal dopamine turnover after unilateral haloperidol injection into the substantia nigra

In freely moving rats, effects of unilateral haloperidol injection into the substantia nigra were monitored with in vivo voltammetry in the bilateral striata. The electrochemical responses at 120 mV versus Ag-AgCl, reflecting mainly a level of 3,4-dihydroxyphenylacetic acid (DOPAC), increased both in the striata within 1.5 h after 5 μg of haloperidol treatment. In the experiments of high-performance liquid chromatography with electrochemical detection, the ratio of DOPAC to dopamine in the striata significantly increased at 2.75 h after drug treatment. These data support the idea that unilateral injection of haloperidol into the substantia nigra in freely moving rats increases dopamine turnover in the bilateral striata.     

ADRENAL PHEOCHROMOCYTOMA WITH BOTH BENIGN AND MALIGNANT COMPONENTS

A case of adrenal pheochromocytoma Is reported characterized by polygonal basophilic granular cells of benign type, plump eosinophilic granular cells of transitional type, and spindle-shaped cells of malignant type. In the primary tumor the neoplastic cells of each type revealed a distinctive topographical distribution. All gradations between the latter two varieties of cells were found, especially in the vicinity of the transitional cell area. Multiple metastases were present in the liver and lungs, where only anaplastic spindle-shaped cells could be found. Ultrastructurally, the benign cells contained predominantly large, rather light, secretory granules with a coarsely granulated core. In the malignant cells, the number, size, and intensity of granules varied considerably from cell to cell or even within a single cell. In general, the malignant cells had a higher frequency of smaller granules with electron-dense homogeneous cores. Moderate amounts of noradrenalin but not significant dopamine or adrenalin could be demonstrated from a metastatic nodule In liver. We postulate that this adrenal medullary pheochromocytoma was benign originally and underwent malignant transformation shortly before the patient's death. This is based upon the patient's clinical features and the peculiar structures of the primary tumor.