Biomedical subjects

T Taguchi

Publications and source records attributed to T Taguchi.

At least 685 records · Page 38Linked to original sources

PubMed1989

An immunohistochemical study of somatostatin-containing nerves in the aganglionic colon of human and rat.

The distribution of somatostatin-like immunoreactive (SOM-LI) nerves was elucidated immunohistochemically in the gut tissues from patients with Hirschsprung's disease and congenital aganglionosis rats. In the normoganglionic human colon, SOM-LI nerve cell bodies were found to a greater extent in the submucous plexus and to a lesser extent in the myenteric plexus. However, they were rarely observed in both the plexuses of the oligoganglionic segment. SOM-LI nerve fibres were widely distributed in the aganglionic bowel. The circular muscle layer of the distal aganglionic segment was densely innervated by SOM-LI nerve fibres which are probably derived from the extrinsic, hypertrophic nerve bundles. A decreased number of the intramuscular nerves fibres were seen in the proximal aganglionic segment. In the colon and rectum from adult and 21-day-old rats, SOM-LI cell bodies were numerous in both plexuses. On the other hand, enteric neurons were completely lacking from the colon and rectum of congenital aganglionosis rats of 21 days old. No neuronal elements staining for SOM were disclosed in these aganglionic segments of mutant rats. A possible origin and pathophysiological role of the extrinsic nerve fibres containing SOM in the diseased bowel are discussed. It is concluded that SOM-LI nerves in the human distal colon comprise both intrinsic and extrinsic elements, while SOM nerves in the rat colon and rectum are of only intrinsic origin.

Animals↗

PubMed1989

Intrahepatic biliary cysts after hepatic portoenterostomy in four children with biliary atresia.

We report our experience with 4 cases of cystic dilatation of intrahepatic bile ducts following hepatic portoenterostomy for biliary atresia. Two of the cases did not achieve satisfactory bile excretion and all four cases developed recurrent cholangitis after hepatic portoenterostomy. The attacks of cholangitis seemed to be associated with the presence of intrahepatic cysts. Although one case resulted in death from hepatic failure, three other cases are now outpatients. Patients who develop recurrent cholangitis following hepatic portoenterostomy, should be examined to exclude the presence of intrahepatic biliary cysts. Ultrasonography, computed tomography and percutaneous transhepatic cholangiography were all effective in detecting cysts and provided valuable information for planning treatment. Percutaneous transhepatic or surgical drainage of the bile ducts was effective in reducing jaundice, and recurrent cholangitis.

Bile Duct Diseases↗

PubMed1989

Thermotolerance of xenografted human gastric cancer.

To compare the thermotolerance in vivo of two human gastric cancers with different doubling times, the xenografted tumors were warmed twice at 43.5 +/- 0.1 degree C in a water bath for 20 minutes at a predetermined interval. In the tumors with doubling times of 5.2 and 10.9 days, a 7-day interval heat treatment resulted in a prolongation in tumor tripling times by 156 per cent and 132 per cent, respectively, compared with a single heat treatment for 40 minutes. On the contrary, two heat treatments given at intervals of 3 to 5 days had a short tumor tripling time, compared to that of the 40-minute single treatment. Thus, the thermotolerance of these human gastric cancers gradually increased to a maximum within a 3- to 4-day interval and disappeared completely after a 7-day interval. These results indicate that the times required to reach maximal thermotolerance in these human gastric cancers were longer than those previously demonstrated for human and rodent cancer cell lines in vitro. The development and decay of thermotolerance in these human gastric cancers need to be considered in the design of multiple-fractionated regimens.

Adenocarcinoma↗

PubMed1989

Different mutations responsible for the elevated sister-chromatid exchange frequencies in Bloom syndrome and X-irradiated B-lymphoblastoid cell lines originating from acute leukemia.

Cell hybridization and co-cultivation protocols have been used to determine whether the increased rates of sister-chromatid exchanges (SCEs) exhibited by Bloom syndrome (BS) and a human mutant cell line (CCRF-SB-T1), originating from an X-irradiated acute leukemia-derived B-lymphoblastoid cell line, have the same or different bases. Cell fusion of CCRF-SB-T1 with each of 4 different BS B-lymphoblastoid cell lines (LCLs), retaining a high-SCE character, exhibited low (normal level) numbers of SCEs, signifying complementation. Co-cultivation of CCRF-SB-T1 and BS B-LCLs also resulted in a significant reduction in SCE level, from 70 to 35, in BS cells, lowered the BrdU concentrations necessary for sister-chromatid differential staining (SCD) from 15 micrograms/ml (0.05 mM) to 2.0 micrograms/ml (0.01 mM) and resulted in a completely normal level of SCE in CCRF-SB-T1 cells. This strongly suggests that the defects in the 2 cell types are different. In the assay of cell extracts, the 4 BS cell lines appear to have lost thymidylate (TMP) synthetase activity (about 50% reduction from that of normal cells), whereas CCRF-SB-T1 cells show a 20% increase of TMP synthetase activity compared to normal cells.

B-Lymphocytes↗

PubMed1989

Increased sister-chromatid exchanges (SCEs) and chromosomal fragilities by BrdU in a human mutant B-lymphoblastoid cell line.

From an X-irradiated human B-lymphoblastoid cell line (CCRF-SB), we have isolated a unique mutant clone (CCRF-SB-T1) which reveals high frequencies of sister-chromatid exchanges (SCEs) and chromosomal fragilities in the C-band regions of chromosomes Nos. 1, 9 and 16, when exposed to high concentrations of bromodeoxyuridine (BrdU). A clear BrdU dose-dependent increase of SCEs (9.6 SCEs/cell at 0.05 mM, 40 SCEs/cell at 0.37 mM on average) in this mutant was observed. Relative contributions of nucleoside and a thymidine (dT) analog of BrdU to high SCEs were studied, since an unusual SCE response to BrdU led us to suspect the significance of BrdU incorporation into DNA and dT pool disturbances. Addition of deoxycytidine (dC), dT or both dC and dT causes an increase of SCEs. On the other hand, deoxyadenosine (dA) and deoxyguanosine (dG) did not have significant effects on SCEs in SB-T1 cells. These results suggest that disturbances of pyrimidine-nucleotide synthesis, including gross imbalance of nucleotide pools, play a pivotal role in the high SCE induction of SB-T1 cells by BrdU.

B-Lymphocytes↗

PubMed1989

Distribution and localization of glial fibrillary acidic protein in colons affected by Hirschsprung's disease.

The distribution and localization of glial fibrillary acidic (GFA) protein were examined by means of immunohistochemistry in normoganglionic, oligoganglionic, and aganglionic segments of colons from 25 patients with Hirschsprung's disease, including four cases of long segment aganglionosis. In normoganglionic segments, GFA protein-positive glial cells were densely distributed within the myenteric plexus, but sparse in the submucous plexus. Aganglionic segments were completely devoid of glial cells with GFA protein immunoreactivity, coinciding with the lack of enteric ganglia. Instead, GFA protein was found specifically in association with the hypertrophic nerve fasciculi and their branches, which were mainly located in the intermuscular zone and submucosal connective tissue in the distal aganglionic segment of diseased bowels. However, two types of short and long segment aganglionosis differed in the distribution pattern of GFA protein; the extrinsic nerve fasciculi in short segment disease extended toward the normoganglionic segment, but in long segment disease they did not reach this area. A moderate number of GFA protein-positive fasciculi were observed within the circular muscle layer of proximal aganglionic and oligoganglionic parts in short segment aganglionosis, while no immunoreactive fasciculi were encountered within the circular muscle layer of the corresponding parts in long segment aganglionosis. Immunohistochemistry for GFA protein can be of excellent diagnostic value for the aganglionic colon with Hirschsprung's disease, since GFA protein immunohistochemistry discloses exclusively extrinsic, hypertrophic nerve fasciculi, characteristic of the bowel in cases of Hirschsprung's disease.

Child↗

PubMed1989

Small intestinal transplantation in the rat: effect on physiological properties of smooth muscle and nerves.

The effect of transplantation on the physiological and pharmacologic properties of small intestine was evaluated in a syngeneic rat model. We examined the intrinsic contractile properties of the smooth muscle, the neural control of intestinal motility, and the sensitivity of the muscle and nerve endings to biologically active compounds in vitro, comparing transplanted tissue to controls. Both graft and control tissue contracted in a dose-dependent manner to cholinergic agonists, 5-hydroxytryptamine, and substance P and relaxed in response to noradrenaline. Contractile properties of smooth muscle and sensitivity to drugs were not altered by transplantation. Excitatory innervation was also similar in all specimens, but the inhibitory response was altered by transplantation. In the control intestine inhibition became maximal above 30 Hz, while in the graft maximal inhibition was obtained at 5 Hz. These findings imply an absence of extrinsic adrenergic inhibitory innervation in the graft. Intrinsic nonadrenergic inhibitory nerves and the excitatory innervation were intact after transplantation.

Animals↗

PubMed1989

Autonomic innervation of the intestine from a baby with megacystis microcolon intestinal hypoperistalsis syndrome: I. Immunohistochemical study.

A typical case of megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is reported. The patient, an infant girl, was fed only by total intravenous nutrition and is now 3 years old. The distribution of several gut peptides was examined in the resected small intestine using an immunohistochemical method. Vasoactive intestinal polypeptide (VIP) and peptide histidine methionine (PHM)-containing nerve fibers were decreased; however, substance P- and leucine enkephalin (Leu-ENK)-containing fibers were increased. The imbalance between several kinds of gut peptides might be one the causes of aperistalsis in MMIHS. This is the first report about the gut peptides of MMIHS.

Autonomic Nervous System↗

PubMed1989

Regional differences in the pattern of neurogenic responses in the aganglionic colon from congenitally aganglionic rats.

The pattern of innervation in the aganglionic colon and internal anal sphincter from cogenitally aganglionic rats was studied and compared with that of control littermates. In normoganglionic colon and anal sphincter, electrical stimulation evoked excitatory or inhibitory junction potentials followed by a contraction or relaxation, respectively. These responses were abolished by tetrodotoxin and atropine selectively abolished the excitatory effects, indicating that the colon or anal sphincter is innervated by intrinsic cholinergic excitatory and noncholinergic inhibitory nerves. In congenitally aganglionic rats, electrical stimulation evoked excitatory and inhibitory responses in sphincteric regions, while only excitatory responses were observed in distal segments. Excitatory responses were weak in proximal segments of the aganglionic colon and electrical stimulation failed to evoke neurogenic responses. These results indicate regional differences in the functional innervation of extrinsic nerve fibers in the aganglionic colon from congenitally aganglionic rats and the usefulness of congenitally aganglionic rats as an animal model for Hirschsprung's disease.

Anal Canal↗

PubMed1989

Function of smooth muscle and nerve after small intestinal transplantation in the rat: effect of storing donor bowel in Eurocollins.

Lewis rats received syngeneic heterotopic grafts of jejunum immediately, or after preservation for 24 or 48 hours in Eurocollins solution. Most recipients of tissue stored for 0 or 24 hours remained healthy. Longer storage caused death of the recipients. We evaluated the effect of tissue preservation by comparing grafts stored for 0 and 24 hours with control jejunum at successive intervals up to ten days after transplantation. The physiology and pharmacology of smooth muscle and nerve endings were studied in vitro. Circular and longitudinal muscle in all specimens contracted in response to cholinergic agonists, phenylephrine, and substance P, and was relaxed by isoproterenol and noradrenaline. 5-hydroxytryptamine caused contraction of longitudinal muscle in all cases, and of both muscle layers in grafts that had been stored prior to transplantation. In all grafts, the excitatory innervation was similar to control, while the extrinsic adrenergic inhibition was absent. Prior storage caused an additional loss of intrinsic nonadrenergic inhibition, but this recovered within eight days. These findings indicate that Eurocollins solution might be a useful vehicle for the preservation of donor intestine prior to transplantation, as long as the period of storage does not exceed 24 hours.

Animals↗

PubMed1989

The role of the fibrinolytic system in acute myocardial infarction after a normal exercise test.

A 67-year-old man had an acute myocardial infarction with thrombosis in the left anterior descending artery shortly after normal exercise. We were able to measure the fibrinolytic components in this patient just prior to his developing acute myocardial infarction as well as during convalescence. In this case, marked increase in total plasminogen activator inhibitor-1 (PAI-1) antigen, mainly due to free PAI-1 antigen, was observed in basal conditions before the onset of acute myocardial infarction. On the appearance of ischaemia, plasminogen activator activity was suppressed, probably due to decreased tissue plasminogen activator antigen release and increased PAI activity, compared with that during convalescence. This suggests that some patients with coronary artery disease who have a high level of free PAI-1 antigen in basal conditions may have a strong tendency to develop acute myocardial infarction, due to further impaired fibrinolysis on the induction of ischaemia.

Acute Disease↗

PubMed1989

Patent ductus arteriosus with Eisenmenger's syndrome detected by first-pass study.

The case of a 20-year-old man with patent ductus arteriosus complicated with Eisenmenger's syndrome is described. Radionuclide angiocardiography characterized the abnormal pattern of blood flow through the central circulation to establish a diagnosis of patent ductus arteriosus with a significant right-to-left shunt, which had not been indicated by other clinical findings.

Adult↗

PubMed1989

Mass screening for breast cancer: comparison of the clinical stages and prognosis of breast cancer detected by mass screening and in out-patient clinics.

To establish the criteria for assessing the life-prolonging effect of mass screening for breast cancer, clinical stage and prognosis of breast cancer detected by mass screening in 11 regions of Japan were compared with those for matched patients in out-patient clinics. A total of 728 patients detected by mass screening and 1,450 found in the out-patient clinics were reviewed. The stage of the disease was Tis or I in 40.9% of the patients detected by mass screening, and 28.7% of those found in the out-patient clinics. In contrast, stage III was found in 9.3% and 14.6%, respectively, indicating that early stages were significantly more common in the patients detected by mass screening. The overall survival curve for the patients detected by mass screening was compared with that for those found in the out-patient clinics. The 5-year survival rate was significantly higher in the patients detected by mass screening (91.7% vs. 85.6%; P less than 0.01), while the 10-year survival rate was slightly higher in the same group of patients, but the difference from the other group was not significant (80.5% vs. 78.1%). Women who had conducted breast self-examination (BSE) showed a higher survival rate than those who had not conducted BSE.

Breast Neoplasms↗

PubMed1989

Acute myocardial infarction shortly after negative exercise test and reperfusion by intracoronary thrombolysis.

A 67-year-old man developed an acute myocardial infarction shortly after normal exercise testing. His clinical history and findings from emergency coronary arteriography suggested that coronary artery spasm followed by intraluminal thrombosis might have been responsible for the myocardial infarction. Although intracoronary thrombolysis two hours after the onset of chest pain provided continued patency of an occluded vessel, serial myocardial perfusion scintigraphies documented myocardial injury, which was probably induced by reperfusion, rather than myocardial salvage.

Aged↗

PubMed1989

The blood vascular architecture of the rat thyroid gland: a scanning electron microscope study of corrosion casts.

The blood vascular bed of the rat thyroid gland was reproduced by injection of a methacrylate casting medium and observed with a scanning electron microscope. The rat thyroid gland received the superior and inferior thyroid arteries and emitted the superior and inferior thyroid veins. Anastomosis between the interlobular arteries or between the interlobular veins was frequently observed in the thyroid gland. The arteriovenous anastomosis was rarely observed between the terminal branches of the lobular arteries and veins. The thyroid blood vascular bed was divided into lobular units which consisted of basket-like capillary networks surrounding the thyroid follicles; a small lobular unit consisted of a few networks, whereas a large one of fifty or more networks. Sizes and forms of the networks varied widely in each case. However, the networks in the superficial layers of the lateral parts of the thyroid gland were typically most developed. Regardless of its size and form, each network always received a proper efferent vessel continuous with the lobular vein, though it was sometimes provided with an accessory afferent or efferent vessel. Only occasionally were the adjacent networks fused with each other or connected by transfollicular capillaries. Thus, the present data suggest that each follicular capillary network is a fairly independent functional-unit in the thyroid microcirculation. The capillaries of the network were sinusoidal in nature and sometimes protruded fine projections which indicated the neogenesis of capillaries. The blood vascular bed of the newborn rat thyroid gland was not always differentiated into basket-like capillary networks.

Animals↗

PubMed1989

The blood vascular architecture of the rat testis: a scanning electron microscopic study of corrosion casts followed by light microscopy of tissue sections.

The blood vascular bed of the rat testis was studied by scanning electron microscopy (SEM) of corrosion casts and by light microscopy of tissue sections. The testicular artery penetrates the pampiniform plexus and gives rise to the intertubular arterioles. Each of these arterioles courses in the intertubular connective tissue column, and gives off intertubular and peritubular capillaries. The intertubular capillaries pass the intertubular connective tissue column, whereas the peritubular capillaries reach the peritubular connective tissue sheet. The intertubular and peritubular capillaries anastomose with each other and converge into the intertubular venules in the intertubular connective tissue columns. Thus, the blood vascular bed of the rat testis consists of hexago- or pentago-columnar capillary networks which commonly surround the seminiferous tubules. The Leidig's cells are preferentially observed in the intertubular connective tissue columns. One of the intertubular capillaries is consistently thick, and directly continues into the intertubular venules (arteriolo-venular capillary channels), which finally drain into the pampiniform plexus. These findings suggest that the male sex hormone, testosterone, as secreted by the Leidig's cells, is discharged into the intertubular capillaries and then mainly carried by the arteriolo-venular capillary channels and intertubular venules into the pampiniform plexus. This specialized drainage may ensure the presence of highly concentrated testosterone in the pampiniform plexus and allow the testosterone-exchange from the pamipiniform plexus to the testicular artery. The arteriolo-venular capillary channels may also eliminate blood congestion in the testis to enhance the efficiency of the heat-exchange mechanism between the testicular artery and pampiniform plexus. Many arterio-arterial and arterio-venous anastomoses occur, which may regulate the blood flow within the testis.

Animals↗

PubMed1989

Blood vascular beds of rat adrenal and accessory adrenal glands, with special reference to the corticomedullary portal system: a further scanning electron microscopic study of corrosion casts and tissue specimens.

Blood vascular casts of the rat adrenal glands were observed with a scanning electron microscope. The cortical capillary plexus drains, through the corticomedullary venous radicles, into the subcortical veins continuous with the medullary collecting veins. The medullary capillary plexus drains into the corticomedullary venous radicles, subcortical veins and medullary collecting veins. No portal vessel was noted between the cortical and medullary capillaries. These findings indicate that the cortical blood rich in glucocorticoids preferentially and continuously flows into the corticomedullary venous radicles, subcortical veins and medullary collecting veins all three of which are fenestrated in type, and also suggest that the vascular route from the cortical capillaries to the medullary collecting veins functions as a substitute for the portal system, controlling the biosynthesis of catecholamines in the adrenal medulla. The vascular bed of the accessory adrenal gland (extra-adrenal cortical or chromaffin body) is sometimes annexed to that of the adrenal gland. On rare occasions, the vascular beds of the extra-adrenal cortical and chromaffin bodies fuse with each other. Additional scanning of tissue samples confirmed the direct drainage of cortical capillaries into the medullary veins and also the endothelial fenestrations of these capillaries and veins.

Adrenal Glands↗

PubMed1989

Microvascular organization of human palatine tonsils.

We describe the three-dimensional organization of the microvasculature of human palatine tonsils as revealed by the vascular corrosion casting/scanning electron microscope method and light microscopy of sections. The tonsillar arteries travel in the connective tissue septa and give off many branches. They further branch into arterioles which in turn enter the follicle and the interfollicular region. These arterioles, giving off capillaries en route, reach the subepithelial region where they break up into sinusoidal capillaries. The subepithelial capillary network overlying the follicle protrudes hemispherically towards the crypt, while that overlying the interfollicular region has many switch-back loops of capillaries projected towards the crypt. The subepithelial sinusoids gather into the high endothelial venules (HEVs) which, collecting capillaries in the follicle and the interfollicular region en route, course down into the interfollicular region alongside the follicle. The HEVs surround the lateral and basal surfaces of the follicle and ultimately lead into the ordinary veins in the septa. The subepithelial sinusoids seem to be involved in taking up immunoglobulins secreted by plasma cells and any other substances released by lymphocytes and/or macrophages as well as supplying the tissues with necessary oxygen and nutrients. That the HEVs are downstream to the subepithelial sinusoids suggests that some substances which are taken up into the sinusoids and transported to the postcapillary venules induce differentiation of HEVs and maintain them.

Humans↗