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Biomedical subjects

K Suda

Publications and source records attributed to K Suda.

At least 343 records · Page 19Linked to original sources

A histopathologic study of the region of the ampulla of Vater in congenital biliary atresia.

A histopathologic investigation of the duodenal wall and adjacent tissues in the vicinity of the papilla of Vater was performed in 37 autopsied cases of congenital biliary atresia which were treated in the Department of Pediatric Surgery of the Juntendo University Hospital during the past 11 years. A high incidence of the association of a congentially abnormal junction of the common bile duct and pancreatic duct, that is, a long common channel and a poorly developed sphincter musculature, were found in congenital biliary atresia. This suggests the possibility that reflux of pancreatic juice into the biliary system, followed by nonsuppurative chronic inflammation of bile ducts, may ultimately lead to the obstructive cholangiopathy seen in biliary atresia.

Ampulla of Vater↗

The choledocho-pancreatico-ductal junction in infantile obstructive jaundice diseases.

A histopathological study on how the common bile duct and main pancreatic duct open into the duodenum was performed on autopsied cases of infantile obstructive jaundice diseases, and control cases. The so-called "common channel" formation type (Type III) was divided into two types; the junction of the common bile duct and the pancreatic duct was situated in the mucosal or submucosal layer of the duodenum in type IIIa and the junction below the propria muscularis of the duodenum in type IIIb. Type IIIb was identified in 17 out of 28 cases in congenital biliary atresia and in 2 cases of congenital choledochal cyst, while the control cases all belonged to type IIIa. In cases of type IIIb the well-developed sphincter muscle was located in the submucosal layer and it surrounded the common channel after joining of both ducts suggesting the possibility of free communication of both ducts. As the intraductal pressure of pancreatic duct is normally higher than that of the bile duct, reflux of pancreatic juice may occur into the bile duct. Abnormal choledocho-pancreaticoductal junction was suggested to be a pathogenic factor which causes infantile obstructive jaundice diseases. ACTA PATHOL. JPN. 30: 187 approximately 194, 1980.

Bile Duct Diseases↗

In vitro secretion of follicle-stimulating hormone by pituitary chromophobe adenomas.

Of 20 female and 14 male patients with chromophobe adenomas, 4 male patients, aged 38 to 47 years, and one female patient, aged 54, showed above normal basal plasma levels of follicle-stimulating hormone (FSH). An in vitro tissue culture study that was performed using chromophobe cells obtained from 3 of the 4 male patients and the 1 female patient showed moderate FSH secretion into the culture media. The secretion of FSH by pituitary chromophobe adenomas might be more frequent than hitherto suspected.

Adenoma, Chromophobe↗

Abnormal choledocho-pancreatico ductal junction related to the etiology of infantile obstructive jaundice diseases.

According to our current radiologic, histopathologic, and experimental studies, the congenital stenosis associated with anomalous choledocho-pancreatico ductal junction is considered to be the most important etiologic factor in congenital biliary dilatation. Furthermore, the possibility of pancreatic juice reflux into the biliary tract due to the abnormal choledocho-pancreatico ductal junction, which could lead to obstructive cholangiopathy, was suggested in relation to the pathogenesis of congenital biliary atresia.

Animals↗

Selective retrograde transsynaptic transfer of a protein, tetanus toxin, subsequent to its retrograde axonal transport.

The fate of tetanus toxin (mol wt 150,000) subsequent to its retrograde axonal transport in peripheral sympathetic neurons of the rat was studied by both electron microscope autoradiography and cytochemistry using toxin-horseradish peroxidase (HRP) coupling products, and compared to that of nerve growth factor (NGF), cholera toxin, and the lectins wheat germ agglutinin (WGA), phytohaemagglutinin (PHA), and ricin. All these macromolecules are taken up by adrenergic nerve terminals and transported retrogradely in a selective, highly efficient manner. This selective uptake and transport is a consequence of the binding of these macromolecules to specific receptive sites on the nerve terminal membrane. All these ligands are transported in the axons within smooth vesicles, cisternae, and tubules. In the cell bodies these membrane compartments fuse and most of the transported macromolecules are finally incorporated into lysosomes. The cell nuclei, the parallel golgi cisternae, and the extracellular space always remain unlabeled. In case the tetanus toxin, however, a substantial fraction of the labeled material appears in presynaptic cholinergic nerve terminals which innervate the labeled ganglion cells. In these terminals tetanus toxin-HRP is localized in 500-1,000 A diam vesicles. In contrast, such a retrograde transsynaptic transfer is not at all or only very rarely detectable after retrograde transport of cholera toxin, NGF, WGA, PHA, or ricin. An atoxic fragment of the tetanus toxin, which contains the ganglioside-binding site, behaves like intact toxin. With all these macromolecules, the extracellular space and the glial cells in the ganglion remain unlabeled. We conclude that the selectivity of this transsynaptic transfer of tetanus toxin is due to a selective release of the toxin from the postsynaptic dendrites. This release is immediately followed by an uptake into the presynaptic terminals.

Adrenergic Fibers↗

Argyrophil cells in the exocrine pancreas.

The silver positive cells of the exocrine pancreas and primary pancreatic cancers were studied with the Grimelius silver stain and the Fontana-Masson technique. In the pancreas, cells containing black granules with the Grimelius method, which at the same time react negative to Fontana-Masson, are considered argyrophil. These cells were present in the basal portion of some of the acinar tissue and in the ductal epithelia, as well as in the A cells of islets. The incidence and distribution of these argyrophil cells were also studied in a variety of ductal lesions. In the so-called ductal proliferation numerous numbers of positive cells were found. Argyrophil cells were frequently situated in the basal portion of ductal squamous cell metaplasia. In goblet cell metaplasia the numbers were few, and less than in normal ducts. We concluded that the distribution and incidence of argyrophil cells in the ductal epithelia is related to chronic pancreatitis, and in particular to regenerative processes. The incidence of argyrophil cells in primary pancreatic cancer, excluding islets cell origin, was 18 per 41 cases (43.4%). We considered them pancreatic cancer with argyrophil cells.

Humans↗

Nerve growth factor in mouse and rat serum: correlation between bioassay and radioimmunoassay determinations.

High levels of nerve growth factor (NGF) determined by competition radioimmunoassay do not agree with values obtained by bioassay. This discrepancy is illustrated here with rat and mouse serum as examples in which values up to 1000 ng/ml have been found by using competition radioimmunoassays. An explanation for the discordant results is presented: serum components bind NGF with an intermediate affinity (Kd = 10(-7) M) but with a very large capacity (up to 0.5 mg of NGF per ml of rat serum). The binding of 125I-labeled NGF to serum components competes with the binding to the solid-phase antibodies (Kd = 10(-9)M) present in limiting amounts, according to the principle of competition radioimmunoassays. Thus, less radioactivity is recovered bound to the antibodies and this gives the erroneous impression that NGF is present. To overcome this difficulty, a two-site radioimmunoassay has been developed which utilizes nonlimiting numbers of antibody binding sites. This assay provides a reliable determination of NGF levels in serum and it can be shown that in rat and mouse serum (either sex) there is less than 5 ng of NGF per ml, in agreement with the results of the bioassay.

Animals↗

Biochemical and ultrastructural evaluation of isolated rat liver systems perfused with a hemoglobin-free medium.

The viability of hemoglobin-free perfused rat liver was examined with respect to several liver functions and to the intactness of subcellular structures under electron microscopic observation. Provided that rat livers were perfused with the oxygenated buffer solution at a flow rate between 3 and 3.5 ml/min per g of liver, all the biochemical parameters measured in the perfused liver system, i.e. the rates of glucose, pyruvate, and lactate production, the rate of oxygen consumption and the tissue contents of adenine nucleotides, were similar to those observed with perfusion systems containing erythrocytes or albumin. The perfused liver showed a sensitive response to norepinephrine, involving a reduction of pyridine nucleotides and enhancements of glucose production and oxygen consumption. On electron microscopic examination, changes in hepatic-structure indicative of hypoxic injury particularly vacuolar degeneration and mitochondrial swelling, were not detected in the liver after 70 min of perfusion; the fact that the fine structure of the hepatocyte was preserved in all parts of the organ confirmed that the supply of oxygen to the perfused liver was sufficient under the conditions employed. From viewpoint of the generally accepted criteria for the viability of perfused liver, therefore, the results confirmed that the perfusion of liver with a hemoglobin- and albumin-free medium is a convenient and reliable tool for biochemical investigation of the reactions occurring in whole liver.

Adenine Nucleotides↗

A histopathological study of the remnant of extrahepatic bile duct in so-called uncorrectable biliary atresia.

Histopathological study of the remnant of extrahepatic bile ducts in 40 cases of so-called uncorrectable biliary atresia, upon which we operated the last three years, has been performed. The histological findings of the remnant were classified into three types. Only two cases were found to have type 1a ducts in the porta hepatis area, from which we can expect better prognosis postoperatively. We also found that as the patients become older, the size of the duct in the remnant becomes smaller and the hepatic fibrosis becomes more remarkable. Therefore the operation should be performed in the infant with this lesion as young as possible. As for the evaluation of operative results of hepatic portoenterostomy for this lesion, a proper evaluation can be made only in those cases in which a microscopic examination of the remnant of extrahepatic bile duct at the porta hepatis area has been adequately performed. Concerning the pathogenesis of biliary atresia, we presume that congenital abnormalities of bile ducts are a basic factor, and additional nonspecific inflammation and bile stasis complete its pathological condition.

Age Factors↗

Potentiation of the NGF-mediated nerve fiber outgrowth by ginsenoside Rb1 in organ cultures of chicken dorsal root ganglia.

The fiber outgrowth induced by ACh, dibutyryl cyclic AMP and dibutyryl cyclic GMP in explanted chick embryonic dorsal root ganglia differed distinctly from that be nerve growth factor (NGF) and submandibular gland extract of adult male mice. Ginsenoside Rb1 potentiated the effects of NGF and submandibular extract at concentrations of 3 and 30 muM, but did not potentiate the effects of ACh, dibutyryl cyclic AMP and dibutyryl cyclic GMP. NGF-antibody inhibited the effects of NGF, but not the effects of ACh, dibutyryl cyclic AMP and dibutyryl cyclic GMP, Concanavalin A and KCL did not promote fiber outgrowth.

Acetylcholine↗