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Biomedical subjects

T Chiba

Publications and source records attributed to T Chiba.

At least 595 records · Page 33Linked to original sources
PubMed1985

Short term histological liver changes in extrahepatic biliary atresia with good postoperative bile drainage.

Short term histological liver changes were studied in 13 patients with congenital biliary atresia, who showed good bile drainage after radical operation. Biopsies obtained at the time of the corrective surgery and at the second operation to convert from external total to partial bile drainage (undertaken once the bilirubin concentration was less than 30.8 mumol/l) were compared. A significant correlation was found between histological findings and the clinical course. In particular, at the second biopsy an increase in hepatic fibrosis and cell infiltration was observed mainly in patients whose bilirubin concentration decreased slowly or who had cholangitis, or both. Hepatic fibrosis and cell infiltration had decreased, however, in an appreciable number of patients whose postoperative course had been characterised by a rapid reduction in the bilirubin concentration and no cholangitis.

Bile↗
PubMed1985

Vagal regulation of GRP, gastric somatostatin, and gastrin secretion in vitro.

The effect of electrical stimulation of the vagus nerves on the release of immunoreactive gastrin-releasing peptide (GRP), gastrin, and somatostatin was investigated using the isolated perfused rat stomach. Electrical stimulation (10 Hz, 1 ms duration, 10 V) of the peripheral end of the subdiaphragmatic vagal trunks produced a significant increase in both GRP and gastrin but a decrease in somatostatin. The infusion of atropine sulfate at a concentration of 10(-5) M augmented GRP release and reversed the decrease in somatostatin release in response to vagal stimulation to an increase above basal levels. However, the gastrin response to vagal stimulation was not affected by atropine. The infusion of hexamethonium bromide at a concentration of 10(-4) M significantly suppressed GRP release but did not affect gastrin secretion in response to vagal stimulation. On the other hand, the somatostatin response to vagal stimulation was completely abolished by hexamethonium. These findings lead us to conclude that the intramural GRP neurons might play an important role in the regulation of gastrin as well as somatostatin secretion and that somatostatin secretion may be controlled not only by a cholinergic inhibitory neuron but also by a noncholinergic, e.g., peptidergic stimulatory neuron, both of which may be regulated through preganglionic vagal fibers via nicotinic receptors. In addition, because the infusion of 10(-7) M GRP suppressed the somatostatin secretion, we suggest that either GRP should be excluded from the list of candidates for the noncholinergic stimulatory neurotransmitter for somatostatin secretion or that there are different mechanisms of action for endogenous and exogenous GRP.

Animals↗
PubMed1985

A cell line from pleomorphic adenoma of the rat salivary gland.

Pleomorphic adenoma of rat salivary gland is extremely rare, and culture of cells obtained from rat salivary gland tumors has not been reported. We have established a long-term cell line from a pleomorphic adenoma of a Sprague-Dawley rat submaxillary gland. The pleomorphic adenoma was composed of oval or spindle-shaped cells occasionally forming a small duct. Alcian blue-positive intercellular matrices, consisting mainly of glycosaminoglycans, were abundant. The cultured cells showed characteristics similar to those of the original tumor. This cell line should be useful for biological and biochemical studies of glycosaminoglycan-synthesis of pleomorphic adenoma cells.

Adenoma, Pleomorphic↗
PubMed1985

Studies on the changes of serum bilirubin level after surgery in biliary atresia.

In biliary atresia, one-fourth of the patients showed prolonged jaundice in spite of a good excretion of bile after surgery. To investigate the cause of jaundice, factors related to the serum bilirubin level were examined in 28 recent cases. Furthermore, clinical analysis was performed in 86 cases of good excretion of bile after surgery. The following results were obtained: The daily amount of bilirubin excretion in bile and bilirubin concentration play an important role in decreasing the serum bilirubin level. The most important factor for prolonged jaundice is ascending cholangitis. Shortening of the life span of the red blood cells is one of the causes of prolonged jaundice.

Bile Ducts↗
PubMed1985

Ultrastructure of the glomerular corpuscular nerve endings in the subepithelium of human epiglottis.

The nerve endings in the subepithelial tissue of the surgically removed human epiglottis were observed by electron microscopy. The nerve varicosities (3-6 microns in diameter) with an accumulation of mitochondria and interconnecting nerve fibers supported by Schwann cells constituted the glomerular corpuscles (50-70 microns in diameter). The processes of the nerve varicosities, containing small clear and large dense cored synaptic-like vesicles, were in contact with basal cells of the stratified squamous epithelium. The glomerular corpuscular nerve endings are presumed to be concerned with low threshold mechanoreceptive functions, such as tactile sensation.

Aged↗
PubMed1985

Studies on beta-lactam antibiotics. IX. Synthesis and biological activity of a new orally active cephalosporin, cefixime (FK027).

The synthesis and some biological properties of 7 beta-[(Z)-2-(2-amino-4-thiazolyl)-2-(carboxymethoxyimino) acetamido]-3-vinyl-3-cephem-4-carboxylic acid (3, FK027) are described. Diphenylmethyl 7-amino-3-vinyl-3-cephem-4-carboxylate hydrochloride (8), the cephem precursor to FK027 was prepared from 7-aminocephalosporanic acid (7-ACA) by two parallel routes differing primarily in the protection of the 7-amino group. Compound 8 was alternatively prepared from deacetylcephalosporin C sodium salt (DCCNa) with improved yields. Two pathways for the conversion of 8 to FK027 are provided. The new orally active cephalosporin, FK027, possesses a widely expanded antimicrobial activity and high stability to beta-lactamases.

Administration, Oral↗
PubMed1984

Distribution of substance P immunoreactive nerve terminals within the nucleus tractus solitarius of the rat.

The relative density of the substance P (SP) immunoreactive nerve terminals in the subnuclei of the nucleus tractus solitarius (NTS) of the rat was examined by immunohistochemical light and electron microscopy. A higher density of SP immunoreactive terminals was observed in the medial and dorsolateral subnuclei of the rostral levels to the obex, while SP immunoreactive terminals were only sparsely found in the medial, ventrolateral and interstitial subnuclei from levels 1 mm rostral to 0.5 mm caudal to the obex. Most other parts of the NTS were moderately innervated by SP immunoreactive nerve terminals.

Animals↗
PubMed1984

Persistent cervical thymus with a small cyst in a newborn infant.

A boy, aged 1 month, who showed a tumour mass in the right neck, is presented. Operation disclosed that the tumour was a cervical thymus with a small cyst. The cervical thymus degenerated gradually into hypoplasia or thymic cyst due to the abnormal descent of the thymus. It is rare that cervical thymus and/or thymic cyst is detected before the age of one year.

Diagnosis, Differential↗
PubMed1984

Histopathologic prognostic factors in neuroblastic tumors: definition of subtypes of ganglioneuroblastoma and an age-linked classification of neuroblastomas.

Histopathologic prognostic factors of 295 pretreatment tumors of a total 641 neuroblastomas and ganglioneuroblastomas were studied with the use of the following proposed tumor classification. The tumors were divided into 2 groups: stroma-poor (235 cases) and stroma-rich (60 cases) according to their organizational pattern (stromal development). The stroma-poor group was classified further into 2 subgroups: favorable stroma-poor (84% survival) and unfavorable stroma-poor (4.5% survival) according to the patient's age at diagnosis, degree of maturation, and nuclear pathology [mitosis-karyorrhexis index (MKI)] of the neuroblastic cells. The stroma-rich group was further classified into 3 subgroups: well differentiated (100% survival), intermixed (92% survival), and nodular (18% survival) on the basis of morphology of the immature element in the tumor tissue without regard to patient's age or quantitative maturation. Favorable stroma-poor and well-differentiated and intermixed stroma-rich groups seem to make good prognosis groups (87% survival), which show gradual progression along a maturational sequence according to the age of the patient. Unfavorable stroma-poor and nodular stroma-rich groups form poor prognosis groups (7% survival) and show morphological evidence of malignant or aggressive behavior, such as inappropriate immaturity for age, higher MKI, and gross nodule formation by immature neuroblasts.

Adrenal Gland Neoplasms↗
PubMed1984

Histochemical AMD electron microscopic studies of intercellular matrices of papilloma induced by painting DMBA on the skin of mice.

The localization and distribution of glycosaminoglycans (GAG) in papilloma tissue which was introduced by painting DMBA on the back skin of ICR mice were observed by light and electron microscopy. GAG consisting mainly of hyaluronic acid could be detected histochemically on the cell surface and extracellular matrices of the basal layer of the papilloma, but it could not be observed in the non-neoplastic epidermis. After incubation of tissue segments in a medium containing 35SO4, an autoradiograph was made, and 35S-radioactivity was observed in the interface between the papilloma epidermis and dermis. Ultrastructurally, the cell surface of keratinocytes in the basal layer of the papilloma was stained intensely with ruthenium red. A cell line was obtained from the papilloma, and GAG could be demonstrated on the cell surface and in the intercellular matrix of the cultivated keratinocytes by treatment with hyaluronidase. The significance of GAG in the proliferating squamous cells was discussed.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1984

Stimulation of growth hormone by vasoactive intestinal polypeptide in acromegaly.

Vasoactive intestinal polypeptide (VIP) was administered as an iv bolus of 1 micrograms/kg BW to 8 acromegalic patients and in doses of 0.5 and 1 microgram/kg BW to 15 normal volunteers. Both systolic and diastolic blood pressures decreased, and pulse rate increased transiently after VIP injection. VIP stimulated PRL release from the anterior pituitary in normal subjects. Plasma PRL responses to VIP in women were dose dependent and larger than those in men. On the other hand, plasma GH levels rose markedly after VIP injection in all 6 patients with untreated acromegaly. In 2 patients studied after transsphenoidal microadenomectomy, there was no plasma GH response to VIP. In 2 other patients with inactive acromegaly as well as in normal subjects, VIP failed to affect plasma GH levels. In all 6 patients with active acromegaly, LRH (1-2 micrograms/kg BW, iv) did not increase plasma GH levels, but TRH (5-10 micrograms/kg BW, iv) caused significant increases in plasma GH, the magnitude of which was not similar to that of increases seen after VIP injection. Paradoxical GH responses to TRH were not observed in patients in the inactive phase after transsphenoidal surgery. These findings suggest that VIP stimulates GH release in vivo in acromegalic patients. A VIP test as well as a TRH test offer promise as simple and reliable techniques to evaluate the activity of acromegaly, particularly after transsphenoidal surgery.

Acromegaly↗
PubMed1984

Staged orchidopexy with division of spermatic vessels: an experimental study.

To improve the therapeutic results of high undescended testis, we conducted experiments with division of spermatic vessels and replacement of the testis into the scrotum after preparation of undescended testis in rats. The results of this experiment show that 1) testis in which the vessels were divided at the inguinal level showed distinct degeneration from infarction one month postoperatively, 2) testis in which the vessels were divided at the abdominal level appeared normal, and 3) in the rats with preparation of undescended testis, bringing down the testis at some interval after division produces better results as to the recovery of the testis.

Animals↗
PubMed1984

Studies on the relationship between the number of arteriae rectae of intestinal artery and intestinal length.

In the measurement of the length of preserved intestine after massive resection of the intestine, measurement of the length of intestine as it is at the time of operation may produce a large error when compared to the length of the intestine at normal times. Therefore, attention was paid to the number of arteriae rectae of the intestinal artery and a comparison was made between such number and the length of the intestine at normal times in rats and man. As a result, the conclusion was drawn that the measurement of arteriae rectae of the intestinal artery is useful for the estimation of preserved intestine at normal times.

Animals↗
PubMed1984

[The heart in acromegaly: an echocardiographic study].

Clinical examinations including echocardiography were performed for 14 acromegalic patients (five men and nine women, whose mean age was 48.6 years). Three of these had hypertension (HT) above 160/95 mmHg, three had diabetes mellitus (DM). Their cardiac sizes and functions were correlated with the durations of disease and plasma growth hormone (GH) levels. The incidences of HT and DM were also evaluated. Three of 14 patients (22%) had increased cardiothoracic ratios (greater than 55%). Electrocardiographic abnormalities were noted in three patients including two with left ventricular hypertrophy (LVH) and one with interventricular conduction defects with abnormal Q waves. By echocardiography (Table 2), nine patients (64%) were judged to be normal. The remaining five patients (36%) had abnormal echocardiograms. These included LVH (sums of the interventricular and posterior wall thicknesses greater than or equal to 25 mm) in two (25 mm in Case 10, 30 mm in Case 11), increased left ventricular end-diastolic dimension (EDD greater than or equal to 55 mm) in one (72 mm in Case 14) and both abnormalities in two patients (Cases 12 and 13). Two patients (Case 13 and 14), whose %FS were 17% and 22%, respectively, had definite evidence of congestive heart failure. Two patients (Case 11 and 13) met the diagnostic criteria for asymmetric septal hypertrophy. One patient with echocardiographic LVH and another who had increased EDD with LVH had histories of HT (Case 11 and 12). Plasma GH levels in patients with LVH were greater than 100 ng/ml (Cases 10 and 11). The left ventricular hypertrophy and/or increased EDD observed in these patients seemed related to the duration of acromegaly but not to the presence of DM. Myocardial biopsy of the right ventricle in two patients with congestive heart failure disclosed myocardial hypertrophy, myocardial fiber disarray, interstitial fibrosis and large nuclei.

Acromegaly↗