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I Sasaki

Publications and source records attributed to I Sasaki.

At least 145 records · Page 8Linked to original sources
PubMed1990

[Effect of ileo-jejunal transposition on intestinal structure, plasma enteroglucagon level and evoked potential difference in dogs].

The effects of ileo-jejunal transposition (IJT) on intestinal structure, gastro-intestinal hormones and D-glucose- and L-glycine-evoked potential difference (PD) were studied in dogs. IJT was performed by isoperistaltic interposition of the distal fourth of the small bowel into the proximal jejunum, 15cm distal from the ligament of Treitz. 1) Following IJT, hyperenteroglucagonemia and an increase of mucosal thickness in the whole small intestine were observed. 2) The D-glucose-evoked PD in the mucosa of the transposed ileum was much lower than that in the preoperative ileal mucosa. On the other hand, L-glycine-evoked PD showed no difference between before and after IJT. These results suggest that both morphological and functional intestinal adaptation will simultaneously occur after IJT. This study also suggests that the mechanism of the intestinal adaptation after IJT may be, at least partly, mediated through the increased release of enteroglucagon.

Animals↗
PubMed1989

Biochemical studies of human (A549) and simian (CV1) cells labeled with 64Cu, 67Cu, and 125IUdR.

CV1 and A549 cells were grown in the presence of 64Cu porphyric complex, 64CuCl2, or 67CuCl2. Radioactive copper determinations were performed on whole cells and on isolated cellular DNA. 125IUdR was used to calibrate the particular extraction and purification procedures we developed because of the half-lives of 64Cu and 67Cu. The results obtained have shown that some radioactive copper atoms remained firmly bound to the DNA molecule. Their amount was of the same order when using two different DNA isolation methods for the two cell lines studied. No significant differences were found when 64Cu was used as CuCl2 or as porphyric complex.

Animals↗
PubMed1989

Self-perpetuating development of encoding biases.

The process of encoding new information involves the imposition of preexisting interpretive categories on newly encountered stimuli, even if the categories do not match perfectly those stimuli. We hypothesized that such encoding of stimuli as supportive of preexisting encoding dispositions may become a source of a perceiver's subjective experiences that support these dispositions. Through this nonconsciously operating mechanism, encoding rules may gradually develop in a self-perpetuating manner, even in the absence of any objectively supportive evidence. Results demonstrated this self-perpetuating process in three studies involving different stimulus materials and experimental tasks (matrix-scanning paradigm and two "intuitive judgment" tasks). The self-perpetuating development of encoding biases is discussed as one of the elementary mechanisms involved in the development of interpretive categories and other individually differentiated cognitive dispositions.

Adult↗
PubMed1989

Similar lethal effect in mammalian cells for two radioisotopes of copper with different decay schemes, 64Cu and 67Cu.

The decays of 64Cu incorporated in human malignant (A549) or monkey nonmalignant (CVI) cells lead to cell death. When plotted as a function of the radioactivity introduced in the growth medium (microCi/ml at t = 0), the residual colony-forming capability decreases exponentially. The slope of the corresponding curve is steeper for A549 than for CV1 cells. Different data show that the cellular lethal event is a consequence of 64Cu transmutation and not of the irradiation by the simultaneously emitted beta- and beta+ particles. Liquid holding results show that the lethal event is irreparable. The decays of 67Cu, another radioisotope of copper, lead to cell death with the same exponential survival curve and the same lethal efficiency as for 64Cu, in spite of their different decay schemes. The lethal efficiency of both copper isotopes is close to that of 125I utilized in the form of iododeoxyuridine under the same experimental conditions as 64Cu and 67Cu. The high lethal efficiency of radioactive copper transmutations raises questions about the role in DNA functioning of copper atoms known to be present in trace amounts in this macromolecule. The lethal consequence of radioactive copper transmutations suggests that the copper atoms bound to DNA are essential for cellular functioning.

Animals↗
PubMed1989

Response of gut glucagon-like immunoreactivity to hypoglycemia in dogs.

Previous studies demonstrated that insulin-induced hypoglycemia enhances glicentin secretion in piglets and prompted us to investigate the response of glucagon-like immunoreactivity (GLI) to hypoglycemia in dogs. Insulin hypoglycemia did not induce any rise of plasma total immunoreactive glucagon (IRG) measured by nonspecific antiserum to glucagon in normal or pancreatectomized dogs under anesthesia. In contrast, insulin-induced hypoglycemia clearly increased plasma total IRG in both normal and pancreatectomized dogs in a conscious state. Administration of acetylcholine resulted in an elevation of plasma total IRG, whereas epinephrine induced a slight increase in plasma total IRG. The infusion of alpha- or beta-adrenergic blockers did not affect the response of plasma total IRG to hypoglycemia, whereas atropine completely blunted the increase in plasma total IRG during insulin hypoglycemia. Similarly atropine abolished the rise of plasma total IRG during intravenous administration of 2-deoxy-D-glucose. It is concluded that hypoglycemia clearly enhances the secretion of GLI from the gut in dogs and that GLI secretion during hypoglycemia is modulated, at least in part, by the autonomic nervous system.

Acetylcholine↗
PubMed1989

Identification of a family of insulin-like growth factor II secreted by cultured rat epithelial-like cell line 18,54-SF: application of a monoclonal antibody.

Somatomedin/insulin-like growth factor (IGF)-like polypeptides (designated SMP) were purified from the serum-free conditioned medium of cultured rat epithelial-like cells, 18,54-SF. A monoclonal antibody (MAb) was produced against partially purified SMP. The antibody was immunoglobulin G1 relatively specific for multiplication-stimulating activity III-2 (rat IGF-II), with a Kd value of 5.6 X 10(-9) M. The antibody showed 100% cross-reactivity with human IGF-II and 10% cross-reactivity with human IGF-I, but did not cross-react with insulin. For purification of SMP, therefore, immunoaffinity chromatography on Sepharose coupled with the MAb was used besides a procedure including ion exchange chromatography, gel filtration, and reverse phase HPLC. The purified SMP (at least five polypeptides) each gave a single peak on reverse phase HPLC and appeared as a single band with an apparent mol wt of 5000-8000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The major components of SMP (designated HP1-SMP and HP3-SMP), which were purified about 100-fold from conditioned medium, stimulated DNA synthesis in human fibroblasts in culture and sulfation in chick embryonic cartilage in culture. These polypeptides showed almost the same cross-reactivity as multiplication-stimulating activity III-2 on RIA with the MAb. The partial amino acid sequences of HP1- and HP3-SMP were determined, and these polypeptides were identified with rat IGF-II.

Animals↗
PubMed1989

Taurocholate-induced gastric damage in rats with obstructive jaundice.

We examined the severity of taurocholate-induced gastric mucosal damage in rats with obstructive jaundice. Oral administration of 100 mM taurocholate induced severer gastric mucosal damage in rats with jaundice than in intact rats. Pretreatment with 5 mM taurocholate significantly protected the gastric mucosa against 100 mM taurocholate-induced damage, suggesting adaptive cytoprotection in rats with jaundice. The reductions in the gastric mucosal potential difference and hexosamine contents in the gastric mucosa in response to 100 mM taurocholate were significantly attenuated by prior administration of 5 mM taurocholate in both intact rats and rats with jaundice.

Animals↗
PubMed1989

[Effect of ileo-jejunal transposition (IJT) on gastrointestinal hormones and intestinal structure in dogs].

The effects of ileo-jejunal transposition (IJT) on gastro-intestinal hormones and intestinal structure have been studied in 9 mongrel dogs. IJT was performed by isoperistaltic interposition of the distal fourth of the small bowel in the jejunum 15 cm distal from the ligament of Treitz. A test meal (carbohydrate- and fat-rich) loading was carried out in 5 dogs before and 4 and 12 weeks after the operation. Plasma concentrations of gastrointestinal hormones (GLI, GI, GIP and gastrin) were measured by radioimmunoassay using the antibodies. The six mongrel dogs were used for the histological studies. Following IJT hyperenteroglucagonemia was observed, especially in postprandial state. An increase of the mucosal thickness in the whole intestine was observed after IJT. This suggested the possibility that enteroglucagon stimulates intestinal mucosal growth as a circulating hormone. Postprandial plasma GIP levels after IJT were significantly lower at the 90, 120 and 150 min after the test meal loading than those of the preoperative state. Plasma gastrin levels were no significant differences before and after surgery. These observations lead us to conclude that enteroglucagon may play an important role in intestinal adaptation mechanisms after IJT.

Animals↗
PubMed1989

[Clinical application of laryngeal mask airway].

The laryngeal mask is a unique alternative to the face mask and endotracheal tube offering significant benefits to both anesthesiologist and patient. We have applied laryngeal mask, 1) to create an adequate airway in cases of difficult or impossible intubation, 2) to establish a pathway for the fiberoptic bronchoscope, 3) to clear the airway for eye operation, and 4) to maintain the airway in patients in the lateral position. Further study, however, is necessary to establish definite indication for its application.

Adult↗
PubMed1989

The effect of alpha-interferon on the liver in a patient with hairy cell leukemia: light and electron microscopic studies.

A daily dose of 3 x 10(6) or 6 x 10(6) units of alpha-interferon was given during two 4- to 6-month periods to a 65-yr-old male patient with hairy cell leukemia, reducing splenomegaly and decreasing the number of hairy cells. Liver biopsy specimens taken during treatment revealed predominantly decreased hairy cell infiltration in the dilated sinusoids and enlarged or vacuolar nuclei of hepatocytes, compared with those in the liver before treatment. The ultrastructure of hepatocytes in specimens taken during treatment showed cytoplasmic vacuoles, weakly stained glycogen particles, and conspicuously decreased endoplasmic reticulum. Liver tests revealed decreased serum cholinesterase and total cholesterol levels in the early stage of treatment, low levels of total protein and albumin during treatment, and a very low value in the [13C]aminopyrine breath test. No clinical reports have been made on the decreased microsomal function during treatment with interferon. alpha-Interferon damaged the endoplasmic reticulum of hepatocytes, although it was effective for the reduction of hairy cells in the liver of hairy cell leukemia.

Aged↗
PubMed1988

Production of IGF-II-related peptide by an anaplastic cell line (AT-3) established from the Dunning prostatic carcinoma of rats.

AT-3 cells, one of anaplastic cell lines established from the Dunning prostatic carcinoma of rats, were able to grow under serum-free conditions in a state of suspension detached from a substratum. Radioimmunoassay using monoclonal antibody against rat insulin-like growth factor II (IGF-II) revealed the presence of IGF-II-related peptide in acid-ethanol extracts of lyophilized serum-free media conditioned by AT-3 cells. The peptide contents in the culture media increased with increase in cell number; 71 ng at 3.0 X 10(6) cells and 449 ng at 4.6 X 10(7) cells. IGF-II-related peptide was hardly detectable in acid-ethanol extracts of AT-3 cells harvested after 13-days culture. These results indicate that AT-3 cells produce IGF-II-related peptide and may release it into the culture media.

Animals↗
PubMed1988

Peptic ulcer and gastric acid secretion in patients with insulinoma.

We evaluated the incidence of associated peptic ulcers and the gastric acid secretion in our 20 series of insulinoma, and obtained the following results: 1) Four out of 20 patients (20%) with insulinoma were associated with peptic ulcers. 2) Except for the maximum acid concentration, the preoperative gastric secretion tests, such as the basal acid output and maximum acid output, failed to indicate hyperacidity in those patients. And patients with a short duration of illness by insulinoma neither showed hyperacidity nor were associated with peptic ulcers. 3) A tendency of reduced gastric acid secretion and the amelioration of peptic ulcers was observed in those who underwent the extirpation of insulinoma. 4) In the most recent case received gastric analysis with continuous monitoring of blood glucose level, an increase of basal acid output was observed during the hypoglycemic period in which the blood glucose levels reduced to around 30 mg/100 ml. These results indicate that the low blood glucose level and the high gastric acid secretion produced under the condition on an empty stomach, may be important factors related to the high association rates of the peptic ulcers in patients with insulinoma.

Adenoma, Islet Cell↗
PubMed1988

Bone metabolism following gastric surgery: microdensitometry and single-photon absorptiometry.

The impairment of bone metabolism was investigated in patients who underwent gastrectomy or vagotomy with drainage two or more years ago. Serum biochemical analysis, microdensitometry of the 2nd metacarpal bone, and measurements of bone mineral content of the radius (measured 1/3 distally) using single-photon absorptiometry were performed at follow-up examination. Although serum levels of calcium, phosphorus and alkaline phosphatase were within normal range, alkaline phosphatase levels were slightly higher for the Billroth II group than for Billroth I. Twenty-eight of 50 gastrectomy cases (56%), and four of 10 vagotomy cases (40%) showed pathologically thin bone: microdensitometric (MD) scores were greater than 3. The Billroth II group showed a far higher frequency of greater MD scores than Billroth I. The MD scores showed significant positive relationship with the age at follow-up, but did not correlate well with the length of the postoperative period. Radial bone mineral content (BMC) was lower in patients with Billroth II anastomosis, or with total or proximal gastrectomy, than in those undergoing Billroth I. These results suggest that metabolic bone disorders following gastric surgery can be detected by MD score and BMC of appendicular bones. However, there was not sufficient resolution with these parameters to detect any bone changes in patients treated with active vitamin D3.

Adult↗
PubMed1988

[Pathophysiology following biliary reconstruction procedures, with special reference to gastric acid secretion, peptic ulcer, metabolism of carbohydrate and fat, and gastrointestinal hormone release].

Pathophysiological effects following biliary tract reconstruction for benign biliary diseases were investigated from the standpoint of gastric acid secretion, metabolism of nutrients and gastrointestinal hormone release. Patients undergoing Roux-Y hepaticojejunostomy showed a significant increase in maximum acid output at follow-up, although only one case of peptic ulcer was observed. In addition, the frequency of cases showing gastric acid hypersecretion was higher than for jejunal interposition hepaticoduodenostomy. Two kinds of test meals (carbohydrate-rich or fat-rich) were given, on different days, to each patient before and about four weeks after surgery. Plasma concentrations of gastrointestinal hormones and glucose or triglyceride were determined. Fasting concentrations of gut hormones (gastrin, GIP, insulin and GLI) were similar to those before surgery, and increased after the ingestion of the test meals. Gastrin and total GLI levels tended to be higher in the Roux-Y than in the interposition group, and vice versa for both insulin and GIP. The changes in plasma glucose and triglyceride, following the Roux-Y procedure, suggest disturbances in carbohydrate tolerance, fat digestion, and in the anabolic phase of absorbed fat. Patients undergoing the Roux-Y procedure should be carefully followed up, since gastric acid hypersecretion induced by a postprandial augmented release of gastrin was observed.

Adult↗
PubMed1988

Effects of the pathway of bile flow on the digestion of fat and the release of gastrointestinal hormones.

The effects of an altered pathway of bile flow upon fat metabolism and gastrointestinal hormone release were investigated in patients undergoing biliary reconstruction procedures or external biliary drainage. After ingestion of a fat-enriched meal, patients with jejunal interposition hepaticoduodenostomy showed the same patterns as controls, with similar levels of plasma triglyceride and gastrointestinal hormones. On the other hand, patients with Roux-Y hepaticojejunostomy or external biliary drainage revealed the impairment of fat metabolism, although the response patterns were different. As for the changes in gastrointestinal hormones in the two groups, both gastric inhibitory polypeptide (GIP) and insulin levels were reduced, whereas glucagon-like immunoreactivity (GLI) levels rose, especially in the external biliary drainage group. It is considered that the disturbance of fat metabolism, in cases of internal or external biliary diversion, is closely related to change in GIP, insulin, and GLI release, in addition to the impairment of mixed micelle formation by bile and of hydrolysis by pancreatic enzymes.

Adolescent↗
PubMed1987

Characterization of acidic actin in mouse sarcoma 180 cells.

Mouse sarcoma 180 cells have a polypeptide that has the same molecular weight as actin but it is more acidic than alpha-actin. Its tryptic peptide pattern on reversed-phase HPLC was very similar to that of beta + gamma-actin, an actin sample prepared by affinity chromatography on DNase I-Sepharose contained the acidic polypeptide, and monoclonal anti-actin antibody reacted with it; therefore, the polypeptide is considered an actin isoform. The mRNA for this variant actin was identified by analyzing the polypeptides translated in vitro, which indicated that the variant actin is not a post-translationally modified form of any known actin. The variant actin was not stained by polyclonal anti-gizzard actin antibody which reacts with gamma-cytoplasmic, alpha-smooth and gamma-smooth muscle actins, nor by polyclonal anti-skeletal muscle actin antibody which reacts with skeletal, cardiac and alpha-smooth muscle actins. These results suggest that this variant actin is related to beta-cytoplasmic actin or, is a novel species whose N-terminal amino acid sequence is not Glu-Glu-Glu.

Actins↗
PubMed1987

The role of humoral factors and the ileocecal valve in pathological changes occurring after distal small bowel resection.

Experimental studies using dogs were performed to elucidate the participation of gastrointestinal hormones as well as the ileocecal valve in postoperative sequelae following massive small bowel resection. Although in both the ileal resection and the ileocecal resection groups the absorption of fat was reduced postoperatively, body weight tended to increase in the former, while it decreased gradually in the latter. In addition, watery diarrhea persisted after ileocecal resection. Plasma total bile acid concentrations in each group were lower than those before surgery, as were plasma levels of both total glucagon and neurotensin. Although differences were not significant, plasma neurotensin levels tended to be higher after ileocecal resection, but plasma total glucagon levels tended to be lower. Plasma gastric inhibitory polypeptide (GIP) response to butter ingestion was also lower after both ileal and ileocecal resection; especially in the latter case the decrease was significant. These results indicate that the diminished plasma levels of neurotensin, enteroglucagon and GIP may be related to the impairment of adaptive changes in the remaining small intestine.

Animals↗