Search PubMed⌕ Search

Biomedical subjects

M Gotoh

Publications and source records attributed to M Gotoh.

At least 325 records · Page 18Linked to original sources
PubMed1991

Hyperglycemia induced by hippocampal administration of neostigmine is suppressed by intrahypothalamic atropine.

We investigated the relationship between the hyperglycemia induced by the administration of neostigmine into the hippocampus and the hypothalamus. Prior to the injection of neostigmine (5 x 10(-8) mol) into the hippocampus, 1 microliter each of atropine or hexamethonium (5 x 10(-11)-5 x 10(-8) mol) was injected into the bilateral ventromedial hypothalamus (VMH). Atropine suppressed in a dose-dependent manner the hyperglycemia induced by hippocampal administration of neostigmine, whereas hexamethonium had no significant effect. These observations suggest that the pathway for this experimental hyperglycemia involves, at least in part, the muscarinic cholinergic neurons in the VMH.

Animals↗
PubMed1991

Relative contribution of nervous system and hormones to CNS-mediated hyperglycemia is determined by the neurochemical specificity in the brain.

To determine whether CNS regulatory pathways are organized so that differential sympathetic outflow patterns occur in response to stress, we injected various doses of neostigmine or bombesin into the third cerebral ventricle of fed rats, and then measured the hepatic venous plasma concentrations of glucose, glucagon, insulin, and epinephrine. The following four groups of rats were studied. Group 1 was intact rats. Group 2 comprised intact rats receiving the constant infusion of a) somatostatin to inhibit the endogenous secretion of insulin and glucagon, and b) insulin to maintain the plasma insulin concentration at basal levels. The infusion was started from -30 minutes and given via a catheter in the femoral vein. Group 3 consisted of rats that underwent bilateral adrenal medullectomy (ADMX) one week before the experiment. Group 4 was ADMX rats administered a constant infusion of somatostain with insulin through a femoral vein, as above. The administration of 1 x 10(-9) mol neostigmine caused hepatic venous hyperglycemia mediated by three distinct pathways: 1) direct innervation of the liver, 2) a direct action of epinephrine on the liver, and 3) the action of glucagon on the liver. We estimated the relative contribution of these three factors to be about 47, 32, and 21%, respectively. Relative contributions of three factors of the doses of 5 x 10(-9) and 5 x 10(-8) mol neostigmine demonstrated an effect similar to that of 1 x 10(-9) mol neostigmine. Epinephrine was shown to be the only agent involved in the hyperglycemic response to intraventricular bombesin at doses of 1 x 10(-10), 1 x 10(-9), and 1 x 10(-8) mol.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Medulla↗
PubMed1991

Age-related changes in the rat detrusor muscle: the contractile response to inorganic ions.

The effect of age on in vitro rat bladder responsiveness function in inorganic ions, CaCl2, KCl, BaCl2 and MgCl2, was investigated, and the results were compared between young (six months old) and aged (16 and 24 months old) rats. In the aged bladders the contractile strength and contractile speed responding to CaCl2 were significantly less compared to the young. On the other hand, the muscle contraction of the three groups following depolarization of the cell membrane by adding KCl and BaCl2 did not differ significantly. The change in muscle relaxation responding to MgCl2 was also insignificant. These results suggest that although contractile and relaxation mechanisms of the detrusor muscle per se are not affected by an aging process, the contractile ability which is related to calcium ion is impaired in the aged rats. It is likely that decreased membrane permeability to calcium ions and/or the change in the intracellular contractile mechanisms related to calcium ions may account for the decreased muscle contractility in the aged rats.

Aging↗
PubMed1991

Improvement in islet yield from a cold-preserved pancreas by pancreatic ductal collagenase distention at the time of harvesting.

This study tried to improve the number of viable islets isolated from a pancreas because a sufficient number cannot be obtained when the organ is preserved in the manner used for pancreas transplantation. The mechanism involved in the decrease in islet yield during preservation was studied to try to develop a better method for islet preparation. First, the integrity of the ductal system was compared between fresh and 6-hr simply preserved (in Hanks' balanced salt solution) rat pancreases. The ductal pressure after ductal injection of HBSS reached a plateau earlier and was significantly lower for the preserved pancreases (0.073 +/- 0.026 min, 410 +/- 17 mmHg, n = 5) than for the fresh ones (0.176 +/- 0.086 min, 561 +/- 103 mmHg, n = 7, P less than 0.05). Second, the extent of pancreatic distention was examined following ductal injection of barium gelatin solution. Solution leakage occurred earlier and distention was less in the preserved pancreas. In addition, the gelatin was found in the capillaries within some islets of the preserved pancreas. These results indicated that the preservation led to a rapid loss of integrity of the ductal system before collagenase injection. We therefore tested the efficacy of ductal collagenase injection at the time of harvesting: 15 ml of 1.0 mg/ml collagenase HBSS was intraductally injected and the pancreas was preserved at 4 degrees C for 2, 4, 6, and 24 hr. The isolation procedure was similar to that used for the fresh pancreas. The yield was significantly better than that of the simply preserved pancreas at 4 hr (241 +/- 22, n = 3, vs. 140 +/- 58, n = 3, P less than 0.05) and at 6 hr (171 +/- 58, n = 14, vs. 32 +/- 33, n = 6, P less than 0.01). These isolated islets were spherical-oval and their viability was confirmed by the ability to reverse STZ-induced diabetes in mice. These results indicated that the integrity of the ductal system, which is necessary for distention of the whole pancreas, was lost during preservation. To solve this problem, ductal collagenase injection should be done at the time of pancreas harvesting and then followed by simple preservation. This method is recommended to obtain viable islets from a preserved pancreas.

Animals↗
PubMed1991

Suppressor cells induced by donor-specific transfusion and deoxyspergualin in rat cardiac xenografts.

The effect of donor-specific blood transfusion (DST), in combination with pretransplant immunosuppression with deoxyspergualin (DSG), on hamster-to-Wistar rat cardiac xenograft survival was assessed. While DST given on day -6 sensitized the recipients, resulting in hyperacute xenograft rejection, the addition of 5 mg/kg/k/day DSG from the day of transfusion to the day of grafting not only prevented hyperacute rejection but resulted in prolongation of graft survival from 3.4 +/- 0.5 days in untreated controls to 7.0 +/- 0.7 days (P less than 0.01). In contrast, DSG alone as pretransplant immunosuppression had no beneficial effect and rejection occurred in 4.0 +/- 0.7 days. This effect appears to be at least donor species-specific, in the sense that ACI cardiac allograft survival was not prolonged when transplanted into xenotransfused and DSG-treated Wistar recipients. DST alone resulted in marked increase in antibody titers, showing the value of 1:512 or more on transplantation day. On the other hand, combined treatment suppressed the titers to 1:1-1:4 on that day. An adoptive cell transfer system was used to analyze the mechanisms underlying this effect. When sublethally irradiated secondary hosts were transferred with 5 x 10(7) lymph node cells (LNCs) harvested on day 0 from xenotransfused and DSG-treated rats, the test heart xenograft survived longer than the irradiated and nontransferred controls, suggesting the presence of suppressor cells. Further in vitro studies demonstrate that LNCs from DST+DSG-treated rats response less in a mixed lymphocyte reaction to hamster LNCs (41% on day 0 [P less than 0.01]), compared with the controls. In coculture experiments, the LNCs from treated recipients suppressed the response of unmodified Wistar LNCs to hamster LNCs by 76% on day 0 compared with the positive controls (P less than 0.01). On the other hand, the transfer of serum taken from treated rats on day 0 did not lead to prolongation of test heart xenografts in syngeneic naive hosts. These findings suggest that the mechanisms underlying the hyporesponsiveness induced by pretreatment with DST and DSG include the induction of suppressor cells, although a degree of clonal deletion can not be ruled out. The generation of serum suppressor factors seems to have no role in this phenomenon.

Animals↗
PubMed1991

Newly established uterine cervical carcinoma cell line with co-amplification of human papillomavirus DNA and c-myc gene.

A new human tumor cell line, NCC-c-CX-1 (CX-1), was established from a uterine cervical cancer xenografted in nude mice. This cell line harbored approximately 50 to 100 copies of human papillomavirus (HPV) type 18 DNA per haploid genome, and contained about 16-fold-amplified c-myc gene with rearrangement. These genomic alterations found in CX-1 cells were also present in both primary tumor and xenografted tumor. Histopathologically, original and xenografted tumors were poorly differentiated cancer and were characterized by neuroendocrine features such as positive neuron-specific enolase and chromogranin A by immunohistochemistry and abundant neurosecretory-type granules in the cytoplasm by electron microscopy. However, the established cell line had lost the neuroendocrine features. This cervical cancer cell line may be a useful model for studying cervical carcinogenesis, especially the interaction between HPV and c-myc oncogene.

Adult↗
PubMed1991

Characterization of high-molecular-mass forms of basic fibroblast growth factor produced by hepatocellular carcinoma cells: possible involvement of basic fibroblast growth factor in hepatocarcinogenesis.

Growth factor(s) with a strong mitogenic effect on BALB/c3T3 cells was purified from an extract of C-Li21 cells, a human hepatocellular carcinoma line, by a combination of heparin-affinity chromatography and reversed-phase high-performance liquid chromatography (HPLC). Two major peaks of mitogenic activity were obtained by reversed-phase HPLC. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the two peaks revealed that one was composed of three proteins with relative molecular masses of 27, 24 and 23 kilodaltons (kD), whereas the other was a single 19-kD protein. Immunoblot analysis showed that all four of these molecules were immunoreactive species of human basic fibroblast growth factor (bFGF). N-Terminal sequence analysis of these molecules revealed that most of them were N-terminally blocked. However, small proportions of the 23- and 19-kD molecules were not blocked, and their respective N-terminal sequences were found to correspond to Gly-40-Gly-27 and Pro29-Phe40 of human bFGF deduced from the cDNA sequence of a human hepatoma cell line, SK-HEP-1. Expression of bFGF in hepatocellular carcinomas was then investigated by RNA blot analysis. All of the examined hepatocellular carcinoma cells expressed bFGF, and the degree of expression was higher in surgically resected hepatocellular carcinomas than in the corresponding adjacent non-cancerous liver tissue. Transcripts of bFGF were not detected in normal liver. These results suggest that C-Li21 cells produce four molecular forms of bFGF, and that bFGF may be involved in hepatocarcinogenesis. Moreover, it appears that bFGF is a potent mitogen toward primary-cultured hepatocytes, and that high-molecular-mass forms of bFGF produced by C-Li21 cells have stronger mitogenic effects on hepatocytes and are more stable under acidic conditions than the low-molecular-mass form, composed of 146 amino acids.

3T3 Cells↗
PubMed1991

Bladder compliance in myelodysplastic children: effect of anti-reflux surgery and conservative treatment. Paediatric urology.

Little is known about changes in bladder compliance and bladder capacity in myelodysplastic patients following anti-reflux surgery. A study group of 70 patients was divided as follows: group A included 20 myelodysplastic patients who had been operated on for reflux and whose subsequent treatment was conservative. Group B comprised 31 myelodysplastic patients who had been treated conservatively; a third group of 19 non-myelodysplastic patients, treated by anti-reflux surgery because of primary reflux, formed the control group. The follow-up period for group A averaged 61 months (extending from a urodynamic study 3 months after surgery to the most recent test). In group B the mean follow-up period between the initial test and the latest test was 86 months. Bladder compliance in group A patients did not increase significantly (from 5.5 to 6.9), but patients in group B did show a significant increase (from 5.9 to 10.7). Compliance in the 19 non-myelodysplastic patients decreased only marginally 6 months after surgery (from 29.6 to 26.3). Changes in bladder capacity showed a similar trend. In their most recent test, however, the bladder capacity of group A patients increased to the same volume as that of group B. A high correlation between radiological bladder deformity and bladder compliance was found. We propose a bladder compliance of 10.0 as the lower limit for myelodysplastic patients' preferred range. It was concluded that anti-reflux operations prevent any improvement in bladder compliance (but not in bladder capacity) compared with conservative treatment.

Adolescent↗
PubMed1991

Bladder dysfunction due to human T-lymphotrophic virus type I associated myelopathy.

Bladder dysfunction is a major complication of human T-lymphotrophic virus type I associated myelopathy (HAM). Four patients (3 females and 1 male, aged between 23 and 44 years), who had suffered from HAM for an average of 6 years complained variously of difficulty in micturition, frequency, bed wetting and/or urge incontinence. They were investigated urodynamically. A significant amount of urine was retained in the bladder of 3 patients. During the storage phase, bladder sensation was well preserved in all 4 patients but severe uninhibited detrusor contractions were observed in 3. At micturition, detrusor contractility was present in 3 and completely lost in 1. Of the 4 patients with HAM, 3 suffered from detrusor hyper-reflexia and 1 from detrusor areflexia.

Adult↗
PubMed1991

Effects of combined therapies with protein-bound polysaccharide (PSK, Krestin) and fluorinated pyrimidine derivatives on experimental liver metastases and on the immunologic capacities of the hosts.

An experimental model is introduced for the study of liver metastases using intrasplenically injected EL-4 and Lewis lung tumor cells. Fluorinated pyrimidine derivatives, 1-(2-tetrahydrofuryl)-5-fluorouracil and 5-fluorouracil, showed inhibitory effects on the frequencies of liver metastases. Immunosuppressive effects of these drugs were compared at the doses capable of showing 50% inhibition of the development of metastatic nodules. These derivatives strongly suppressed the phagocytic activity and the number of Kupffer cells of the liver and then the humoral response against sheep red blood cells, the delayed hypersensitivity against picryl chloride. On the contrary, combined administration of protein-bound polysaccharide (PSK) and 1-(2-tetrahydrofuryl)-5-fluorouracil showed no inhibitory effect on these activities.

Adjuvants, Immunologic↗
PubMed1991

Influence of aging on the rat urinary bladder function.

We studied in vitro the change in bladder function with aging. The responses of muscle strips made from the rat bladder body to eight neurotransmitters and to four inorganic ions were examined. Six-month-old rats were used as controls and 16- and 24-month-old rats as aged rats. The results of this study are summarized as follows: (1) The contractile responses of the aged rat bladder to norepinephrine, adenosine triphosphate, and serotonin were significantly greater than those of young rat bladder. This may contribute to the development of an unstable bladder in elderly people. (2) In the aged rat bladder magnitude and speed of the response to calcium were significantly weaker which may account for the impaired detrusor contractility frequently observed in elderly persons. (3) There was no significant age-related difference in the response to other agents (acetylcholine, prostaglandin F2 alpha, angiotensin II, vasoactive intestinal polypeptide, KCl, BaCl2, and MgCl2).

Aging↗
PubMed1991

Bladder compliance in myelodysplastic children: does antireflux surgery compromise it?

We studied the impact of antireflux surgery on bladder compliance, which was an important clinical parameter in terms of urinary incontinence and upper tract deterioration, in 20 myelodysplastics (group A). For control groups, 31 myelodysplastic children with or without reflux who were conservatively treated (group B) and 19 non-myelodysplastics who were operated on for primary reflux were investigated. The follow-up period averaged 87 months for group A and 86 months for group B. Initial bladder compliance in group A (5.1 +/- 3.7 ml/cm H2O) and group B (5.9 +/- 4.9 ml/cm H2O) was significantly lower than that in nonmyelodysplastics (29.6 +/- 23.1 ml/cm H2O) (p less than 0.01). Antireflux surgery prevented a significant elevation of bladder compliance in group A (6.9 +/- 5.5 ml/cm H2O), while an increase of bladder compliance was significant in group B (10.7 +/- 8.1 ml/cm H2O) (p less than 0.01). In the nonmyelodysplastic group, bladder compliance slightly decreased postoperatively but remained well within the normal range (26.3 +/- 12.0 ml/cm H2O). There was significant correlation between bladder compliance and bladder trabeculation (p less than 0.01), i.e. the higher the bladder compliance, the more normal-appearing the cystogram. We propose a bladder compliance of 10.0 ml/cm H2O as the lower limit of the normal range. Analysis of the present data has led to the hypothesis that any surgical intervention on or around the urinary bladder will result in a low compliance in myelodysplastic patients. We have found, on the other hand, that those who have a normal cystogram, a large bladder capacity, absence of symptomatic urinary infection, and normal renal function before antireflux surgery have a good chance of obtaining the compliant detrusor muscle postoperatively.

Child↗
PubMed1991

Effects of transcatheter hepatic arterial embolization on coagulation and fibrinolysis in patients with hepatocellular carcinoma.

The changes in coagulation and fibrinolysis were studied in cases of hepatocellular carcinoma with (n = 20) and without (n = 8) transcatheter hepatic arterial embolization (TAE). The plasma levels of thrombin-antithrombin III complex (TAT) and alpha 2 plasmin inhibitor complex (PIC) were significantly elevated after TAE, concurrently with a decrease in antithrombin III and antiplasmin (alpha 2-plasmin inhibitor) levels. The elevation of TAT was most significant (2.4-fold of the pre-TAE level) on day 3, whereas that of PIC was relatively less (1.3-fold on day 3). Tissue plasminogen activator in blood was also significantly increased on day 1, but it was decreased thereafter, although plasminogen activator inhibitor (PAI) remained high for at least 7 days after TAE. In contrast, such hematological changes were not observed in patients without TAE. Thus, both coagulation and fibrinolysis were activated after TAE, but its effect on fibrinolysis was less prominent, due probably to the increased synthesis of PAI.

Adult↗
PubMed1991

The effects of vitamin K on the generation of des-gamma-carboxy prothrombin (PIVKA-II) in patients with hepatocellular carcinoma.

The clinical significance of des-gamma-carboxy prothrombin (PIVKA-II) in hepatocellular carcinoma (HCC) was investigated in 112 patients with and without vitamin K administration. The positivity rate of PIVKA-II was significantly decreased in patients receiving vitamin K (28.5%), compared with those without vitamin K administration (54.5%, p less than 0.05). The plasma levels of vitamin K derivatives [phylloquinone (VK1), menaquinone-4 (MK4), and menaquinone-7 (MK7)] measured were not decreased in patients with HCC, but were significantly increased in MK4 and VK1 + MK4 + MK7. The amount of PIVKA-II in plasma did not correlate with the plasma levels of vitamin K derivatives. However, PIVKA-II was decreased by the administration of vitamin K, and all of the six patients with more than 5.0 ng/ml of VK1 + MK4 + MK7 were within normal limits, whereas half of 32 patients with less than that had abnormal levels of PIVKA-II. Thus, it was suggested that PIVKA-II was not elevated due to vitamin K deficiency, but might result from the impaired metabolism or availability of vitamin K in the tumor. Therefore, PIVKA-II should be measured without vitamin K administration.

Biomarkers↗