Electron microscope study on the development of Japanese B encephalitis virus in PS cells

An electron microscope study was performed on the ultrastructure and developmental process of the Mukai strain of Japanese B encephalitis virus propagated in vitro on porcine kidney stable cells. The virus particle of Japanese B encephalitis is hexagonal in sections and approximately 40 m&#956; in the maximum diameter, composed of an outer membrane, 20&#197; thick, viroplasm, 30 &#197; thick and an electron-dense nucleoid, 25 m&#956; in diameter. The virus particles develop by a budding process on the wall of the cytoplasmic vacuole. Thereafter, virus particles are densely packed in the vacuole usually in random arrangement and rarely in crystalline arrays. The vacuole containing virus particles gradually moves toward the cell surface and liberates the virus particles to the exterior of the cells through a narrow canaliculus. A structure suggestive of incomplete virus particles was also observed.</p

A study on the cytomorphologic structure of blood cells by vital staining I. Normal human blood cells in the bone marrow

Vital observation on the cellular morphology of the normal human blood cells was conducted by means of bone marrow culture successfully in conjunction with vital staining with Janus green B and neutral red. A special attention was paid for the alterations of the cellular structures in the course of the culture. The findings are summarized as follows : 1) Intracellular particles with affinity to Janus green B or neutral red were classified into minute granules, granules, vacuoles, and mitochondria. Morphologic features of each type of the particles were studied in detail. 2) Two types of granules are present in neutrophilic and eosinophilic blood cells, whereas one type of granules is present in basophilic blood cells. Eosinophilic and basophilic granules show characteristic pole formation in them at the terminal stage of the staining. 3) The rosette formation in the mature monocyte and the aggregations of neutral red vacuoles in the mature neutrophil and the mature lymphocyte were characterized. 4) The cluster of neutral red vacuoles is characteristic of the erythroblast. 5) The mitochondria of the mature neutrophil and the mature monocyte participate in producing neutral red vacuoles.</p

Electron microscopic demonstration of a new virus isolated from a patient with SMON

The first successful electron-microscopic observation of a virus isolated from a patient with SMON was performed. The morphological and developmental characteristics of this virus suggests that this type of virus has not been isolated from humans. Hence, it is considered that the virus observed is of a new type and presumably the causative agent of SMON. The author wishes to express his profound thanks to Prof. TADASHI OFUJI for painstaking proof reading of the manuscript and also acknowledgement is due to Mr. NOBUO HAYASHI, Mr. NOBORU SAIHARA, Mr. TAKASHI NAKAMURA and Miss TOSHIYO OMIZU for their technical assistance of electron microscopy.</p

Effect of posterior hypothalamic knife cuts on the baroreflex and hemorrhage-induced hormonal responses.

We made posterior hypothalamic knife cuts in rats to transect the fibers of the medial forebrain bundle (MFB) at the level of the mammillary body. The role of the MFB in the baroreflex and hemorrhage-induced hormonal responses was then examined in the unanesthetized, freely moving condition. The slopes for the relationship between changes in pulse interval and mean arterial pressure (MAP) in the posterior-cut group were significantly steeper than those in the sham-cut group both when there were phenylephrine-induced increases in MAP (1.13 +/- 0.07 vs 0.86 +/- 0.10 msec/mmHg) and nitroprusside-induced decreases in MAP (1.16 +/- 0.10 vs 0.77 +/- 0.05 msec/mmHg). This result indicates that posterior cuts elevated baroreflex sensitivity when MAP was increased or decreased. The resting MAP was not changed, but the resting heart rate (HR) was lowered by the posterior cuts. Furthermore, the posterior cuts augmented hypotensive hemorrhage-induced bradycardia. Hypotensive hemorrhage (16-17 ml/kg) caused elevation of the plasma catecholamine, ACTH and vasopressin (AVP) levels, but the posterior cuts attenuated these hormonal responses. These results indicate that the fibers in the MFB have a tonic inhibitory effect on the baroreflex in the resting condition, and play a stimulatory role in hemorrhage-induced catecholamine, ACTH and AVP responses.</p

Reticuloendothelial cell function in autoimmune hemolytic anemia (AIHA): studies on the mechanism of peripheral monocyte activation.

We examined the activity of peripheral blood monocytes in patients with autoimmune hemolytic anemia (AIHA) using an in vitro assay of monocyte-macrophage interaction with erythrocytes and an antibody-dependent cell-mediated cytotoxicity (ADCC) assay. The monocytes of AIHA patients in the hemolyzing period phagocytized autologous sensitized red cells and anti-D coated red cells more avidly than normal control monocytes. There was no significant relationship between phagocytic activity and ADCC activity. The activated monocytes phagocytized autologous sensitized red cells, but had no ADCC activity in a short time 51Cr release assay. Phagocytic activity of the patients' monocytes against autologous erythrocytes rapidly decreased after treatment with prednisolone even though the red cell sensitization with antibody remained almost the same as during the hemolyzing period. We postulated that the activation of monocytes in AIHA was due to the &#34;arming&#34; effect of anti-erythrocyte antibody, but we think that other mechanisms may also be involved in the activation of monocytes.</p

In vitro release of immunoreactive atrial natriuretic peptide from the rat atria.

In vitro release of atrial natriuretic peptide (ANP) from atria was examined by ANP radioimmunoassay. Isolated right rat atria were incubated in Krebs-Ringer bicarbonate buffer, and test substances were added to the incubation medium. The fluid was assayed for rat ANP by a radioimmunoassay method recently developed in our laboratory. We produced an antiserum to human ANP(99-216) (alpha-hANP(1-28)) which showed a good cross-reactivity of 63% with rat ANP(99-126) (alpha-rANP(1-28)) and was useful for measuring rat ANP concentrations of the medium. Application of the medium to a reverse phase high performance liquid chromatography (HPLC) system resulted in a single peak of immunoreactive rat ANP corresponding to a small molecular weight synthetic rat ANP of 28 amino acid residues. Catecholamines (epinephrine, norepinephrine and isoproterenol) reduced the basal secretion of ANP, whereas acetylcholine stimulated the release of ANP. Forskolin and dibutyryl cyclic AMP did not affect the release of ANP. These results suggest the possibility that the regulation of ANP release may be partially associated with adrenergic and cholinergic mechanisms.</p

Mechanism of proteinuria in nephrotic syndrome.

We developed a &#34;tissue negative staining method&#34; to observe the molecular-level ultrastructure in situ in any portion of the ultrathin sections routinely prepared for electron microscopy. This method was used in electron microscopy of the glomerular basement membranes (GBM). The GBM in patients with nephrotic syndrome was discovered to possess a tunnel structure, designated as &#34;nephrotic tunnel&#34;, with lumen large enough to allow free passage of protein molecules. This tunnel seemed to be involved in the etiology of nephrotic syndrome. This new method appears to be applicable to a variety of purposes in biological studies.</p

Ultrastructural changes of the glomerular basement membrane in diabetic nephropathy revealed by newly devised tissue negative staining method.

In order to clarify the mechanism of proteinuria in diabetic nephropathy, ultrastructural changes of the glomerular basement membrane (GBM) in patients with diabetic nephropathy were examined by electron microscopy using our newly devised &#34;tissue negative staining method&#34;. The normal human GBM showed a fine meshwork structure consisting of fibrils forming the small pores. The diameter of these pores was slightly smaller than that of human albumin molecules. The GBM in patients with diabetic nephropathy showed irregular thickening. At higher magnification, hitherto unknown cavities and tunnel structures, which were not seen in normal controls, were observed in the thickened GBM. In some portions, these cavities presented a honeycomb-like appearance. The diameters of the cavities and tunnels were far larger than the dimensions of albumin molecules. These enlarged structures are believed to allow serum protein molecules to pass through the GBM from the capillary lumen to the urinary space. These results suggest that the cause of massive proteinuria in diabetic nephropathy is the disruption of the size barrier of the GBM.</p

Presence of type C virus particles and their aberrant form in mammary carcinoma of a strain C58 mouse

Detailed morphologic characteristics of type C virus particles observed in an X-ray-induced C58 mammary tumor and its transplants have been described. The particles are round and 75 to 100 m&#956; in diameter, containing an electrondense nucleoid 60 to 70 m&#956; in diameter. By the negative staining, they do not show obvious spines. Two abnormal types of particles, i. e. cylindrical and aberrant forms have been observed.</p

A role of central alpha-1 adrenergic mechanism in shaking stress-induced ACTH and noradrenaline secretion.

The role of alpha-1 adrenergic mechanism in the shaking stress-induced adrenocorticotropic hormone (ACTH), and plasma noradrenaline secretion and pressor response were investigated using conscious rats. We also studied whether or not central corticotropin releasing hormone (CRH) is involved in the shaking stress-induced ACTH secretion. The shaking stress caused significant elevations of plasma ACTH, noradrenaline, and systolic blood pressure. Intra-third ventricular administration of alpha-1 adrenergic blocker, bunazosin, inhibited the shaking stress-induced ACTH secretion, but did not alter stress-induced noradrenaline secretion and pressor response. Furthermore, intra-third ventricular administration of CRH antagonist, alpha-helical CRH, significantly attenuated stress-induced ACTH secretion. These results indicate that alpha-1 adrenergic pathway and CRH at least partly mediate the shaking stress-induced ACTH secretion.&#60;/P&#62;</p