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Miyasaka K, Terae S. [Neuroimaging findings in intravascular malignant lymphomatosis]. Rinsho Shinkeigaku 1995; 35:1467-1469. [PMID: 8752432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We reviewed the neuroimaging studies of five patients with intravascular malignant lymphomatosis (IML). All five patients had cerebral symptoms and three had spinal cord or root symptoms. Initial brain CTs, in two patients at the onset of cerebral symptoms, were normal. Brain MR imaging, conducted in four patients during the course of IML, showed multiple white matter lesions which were hyperintense on T2-weighted images. Some of the lesions involved cerebral cortices, and some had mass effect. Serial MR imaging was performed in three patients, and the lesions decreased in size during steroid or CHOP therapy. Gd-DTPA-enhanced study which was conducted in one patient demonstrated enhancement of the white matter lesions. Review of the literature revealed various CT or MR findings; single or multiple cortical or subcortical lesions with or without mass effect, periventricular lesions, and spinal cord lesions. Lesions may or may not be enhanced. Because neuroimaging findings are non-specific, correct diagnosis is difficult to make by imaging studies alone. One should always consider the possibility of IML in the interpretation of radiological images.
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Conn AW, Miyasaka K, Katayama M, Fujita M, Orima H, Barker G, Bohn D. A canine study of cold water drowning in fresh versus salt water. Crit Care Med 1995; 23:2029-37. [PMID: 7497726 DOI: 10.1097/00003246-199512000-00012] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To compare the pathophysiologic changes occurring during drowning in cold fresh water and cold salt water with reference to viability. DESIGN Randomized, prospective, controlled submersion experiments in two contrasting cold liquids. SETTING A laboratory at a large university-affiliated medical institution. SUBJECTS Thirteen healthy, anesthetized mongrel dogs. Three dogs served as controls and were immersed but not submerged. The remainder were submerged in cold fresh water or cold salt water (4 degrees C). INTERVENTIONS Catheters were placed in the femoral artery, right carotid artery and right internal jugular vein. Electrocardiogram, pneumogram, and rectal temperatures were measured continuously during submersion/immersion. MEASUREMENTS AND MAIN RESULTS Cold water submersion with drowning produced a large initial decrease in carotid artery temperature (approximately 7.5 degrees C in the first 2 mins) compared with a minor decrease (approximately 0.8 degrees C with immersion). No significant differences were noted in the rate of decrease of temperature between drowning in fresh water and salt water. During cold fresh water drowning, aspiration produced gross hemodilution with an average increase in body weight of 16.5%. Hematocrit values, serum sodium concentrations, and osmolality decreased while serum potassium concentrations, catecholamines, and free hemoglobin increased. All measured biochemical data (except PaO2) remained at viable levels. By contrast, during cold salt water drowning, average body weight increased by only 6%, with hemoconcentration and a shrinkage of vascular volume. Hematocrit and hemoglobin values increased by 30%, but initial plasma free hemoglobin values remained unchanged. Serum sodium concentrations, osmolality, and potassium concentrations increased rapidly to critical levels. CONCLUSIONS On submersion in cold water, all of the experimental animals developed tachypnea immediately, followed by aspiration with predictable effects. The biochemical and pathophysiologic changes in cold water drowning approximated those changes reported for warm water drowning for both fresh and salt water with one exception and continued aspiration of cold water produced extremely rapid core cooling as long as the circulation remained intact. This process of acute submersion hypothermia may protect the brain temporarily from lethal damage, as reported in cases of cold fresh water drowning. Concentrations of circulating catecholamines increased exponentially in both groups of test animals. Clinically, their acute effects on the circulation, compounded by significant hypothermia and extreme anoxia, must hamper the detection of residual circulation at rescue and may play a role in sudden death from cold water in the absence of drowning.
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Ohta M, Tanaka Y, Masuda M, Miyasaka K, Funakoshi A. Impaired release of cholecystokinin (CCK) from synaptosomes in old rats. Neurosci Lett 1995; 198:161-4. [PMID: 8552311 DOI: 10.1016/0304-3940(95)11990-e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cholecystokinin (CCK) is an abundant neurotransmitter peptide in the brain. CCK release from synaptosomes obtained from the cerebral cortex, the level of CCK mRNA and the tissue concentration of CCK were examined in young and old rats. CCK release stimulated by KCl was attenuated in old rats but that stimulated by calcium ionophore was comparable in animals at both ages. The CCK mRNA level in the cerebral cortex was decreased significantly in old rats despite the significant increase in CCK content. These results suggested that aging impaired CCK release, resulting in tissue accumulation and a decrease in the synthesis of CCK (the level of CCK mRNA).
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Sazaki N, Miyasaka K, Matsumoto M, Funakoshi A. Effects of intraduodenal administration of a low dose of cholecystokinin (CCK) antagonist (CR-1505) on plasma CCK concentration, intestinal CCK content, and levels of CCK mRNA. J Gastroenterol 1995; 30:599-606. [PMID: 8574331 DOI: 10.1007/bf02367785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effects of the intraduodenal administration of a low dose of CR-1505 for 3-7 days on the gene expression of cholecystokinin (CCK), plasma CCK concentration, and CCK content in the intestinal mucosa were examined in rats. The simultaneous changes of protein and enzyme content in the pancreas were also determined. CR-1505 was infused continuously into the duodenum at a dose of 3 mg/kg per day, calculated to correspond to a dose of 150-200 mg/day in humans. Seven days after the administration of CR-1505, a liquid meal (4.5 kcal/3 ml) was introduced into the stomach and changes in the intestinal CCK content and plasma CCK concentration were examined. The level of CCK mRNA in the intestine was significantly higher in rats treated with CR-1505 than in control rats. The plasma CCK concentration, the CCK content of the intestinal mucosa, and the composition of pancreatic enzymes did not significantly differ in rats treated with CR-1505 and the untreated controls. In control rats, the administration of the liquid meal increased the plasma CCK concentration and significantly decreased the intestinal CCK content in water extracts, but did not affect the amount extracts in acid whereas the ingestion of the meal did not cause any significant changes in rats treated with CR-1505. These findings indicate that a low dose of CR-1505 stimulates the gene expression of CCK without enhancing CCK release or exerting an effect on the pancreas.
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Miyasaka K, Funakoshi A. Changes in gene expression of cholecystokinin-A receptor after induction of pancreatitis by pancreatic duct occlusion in rats. J Gastroenterol 1995; 30:683-5. [PMID: 8574345 DOI: 10.1007/bf02367799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Serial changes in the levels of cholecystokinin (CCK)-A receptor mRNA in the pancreas after pancreatic duct occlusion were examined in rats. CCK-A receptor mRNA level was determined by Northern blot analysis with a rat CCK-A-receptor cDNA probe. The level of CCK-A receptor mRNA first decreased, reaching the lowest level 7 days after occlusion, and then began to increase. On day 14, it had completely recovered to the control level and it remained at that level until 28 days after occlusion.
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Miyasaka K, Funakoshi A, Nakamura E, Teraoka H. Regulation of gene expression of pancreatic secretory trypsin inhibitor-61 and -56 by bile and pancreatic juice in rats. Pancreas 1995; 11:246-55. [PMID: 8577678 DOI: 10.1097/00006676-199510000-00006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The rat possesses two pancreatic secretory trypsin inhibitors (PSTI-61 and -56). PSTI-61 has been known to stimulate cholecystokinin (CCK) release, whereas PSTI-56 did not. Both PSTIs are synthesized in the pancreatic acinar cells. CCK has a trophic effect on pancreatic acinar cells, and the exclusion of bile-pancreatic juice from the intestine has been known to be a most potent stimulator of CCK release. In the present study, we examined whether the mRNA levels of PSTI-61 and -56 produced by bile-pancreatic juice diversion were different from each other and compared the changes in CCK mRNA levels in the small intestinal mucosa and the plasma and intestinal CCK concentrations. Male Wistar rats were prepared with internal fistula and bile-pancreatic juice was excluded from the proximal intestine, being introduced into the distal ileum. Rats were sacrificed 1, 3, and 7 days after the operation. The concentrations of plasma and intestinal CCK and the levels of mRNA of CCK in the intestinal mucosa and PSTIs in the pancreas were significantly increased by bile-pancreatic juice diversion. The increase in the mRNA level of PSTI-61 was significantly higher than that of PSTI-56. Administration of CCK antagonist inhibited these changes but administration of CCK agonist could not fully reproduce these changes. These studies suggest that bile-pancreatic juice regulates gene expression of CCK and PSTIs and that the regulatory mechanisms of gene expression of PSTI-61 and -56 may be different.
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Shirato H, Kamada T, Hida K, Koyanagi I, Iwasaki Y, Miyasaka K, Abe H. The role of radiotherapy in the management of spinal cord glioma. Int J Radiat Oncol Biol Phys 1995; 33:323-8. [PMID: 7673019 DOI: 10.1016/0360-3016(95)00179-3] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE To determine the role of radiotherapy in the management of spinal cord gliomas. METHODS AND MATERIALS Thirty-six patients with spinal cord glioma treated between 1979 and 1993 were examined. The patients had 13 astrocytic tumors (7 astrocytomas, 4 anaplastic astrocytomas, 2 glioblastomas), 22 ependymal tumors (18 ependymomas, 4 myxopapillary ependymomas), and 1 unclassified glioma. Fifteen of the patients were treated by surgery alone, but the remaining 21 patients also received postoperative radiotherapy. Total resection was performed on 1 astrocytoma and 13 ependymomas. In general, 40-50 Gy/16-20 fractions/4-5 weeks were given after parital resection, but no radiotherapy was given after total resection. RESULTS Actuarial survival was significantly better for patients with ependymal tumors than for those with astrocytic tumors (p = 0007), 5-year actuarial survival rates being 96% and 50% for patients with ependymal tumors and astrocytic tumors, respectively. For patients with ependymal tumors, there was no difference in motor function and survival between those with total resection and those with partial resection followed by radiotherapy. Actuarial 3-year survival was 80% for patients with astrocytomas and 40% for those with anaplastic astrocytomas plus glioblastomas. The difference in the degree of motor function between the patients treated with radiotherapy and those without radiotherapy was not statistically significant. One anaplastic astrocytoma and one glioblastoma patient have lived longer than 4 years after radical treatment including radiocordectomy, or irradiation using doses larger than the tolerance threshold of the spinal cord. CONCLUSION Postoperative conventional radiotherapy is indicated after less than total resection of low-grade ependymal tumors and astrocytomas but not after total resection of ependymomas. Radiocordectomy may be an option for certain cases with high-grade astrocytic tumors.
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Kitagawa T, Miyasaka K, Kanda H, Yasui H, Hino O. Hepatocarcinogenesis in rodents and humans. J Cancer Res Clin Oncol 1995; 121:511-5. [PMID: 7559729 DOI: 10.1007/bf01197762] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In hepatocarcinogenesis in rodents, induction of foci and nodules comprising clonally proliferated initiated cells is considered to be essential for the future development of carcinomas. Nodules in human cirrhotic liver, though known to be associated with a high hepatocellular carcinoma risk, have generally been regarded as regenerative in nature, and not the result of clonal or neoplastic cell proliferation, on a morphological basis. However, when we analyzed 83 cirrhotic nodules from 11 HBV carrier patients, utilizing hepatitis B virus (HBV) integration as a marker for clonal proliferation, we found the existence of clonal populations of more than 10(5) hepatocytes in 26 (31.3%) of them. Although such clonal cell populations are morphologically not discernible from neighboring hepatocytes, they may have particular histogenetic significance in human hepatocarcinogenesis and clearly deserve further investigation. Allelotype analysis of mouse hepatocellular carcinomas (HCC), induced by a single dose of diethyl nitrosaminine in C3H/MSM F1 hybrids, revealed no remarkable alterations in the original tumors when microsatellite probes were used, but loss of heterozygosity of chromosome 4 at extremely high frequency (95%) in cultured cell lines derived from these HCC. The shortest common region was about 10 cM distal to the interferon alpha gene, in which the p16 gene is located. The results indicated that loss of gene function, most probably including that of the p16 gene, may be essential for immortalization of cultured hepatocytes but that it may not play any role in initiation or early events in mouse hepatocarcinogenesis in vivo. The mouse HCC used for analysis in this study may be comparable with human HCC at an early stage, for which only very limited genetic alterations have so far been identified.
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Miyasaka K, Kanai S, Masuda M, Ohta M, Kawanami T, Matsumoto M, Funakoshi A. Gene expressions of cholecystokinin (CCK) and CCK receptors, and its satiety effect in young and old male rats. Arch Gerontol Geriatr 1995; 21:147-55. [PMID: 15374210 DOI: 10.1016/0167-4943(95)00634-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/1994] [Revised: 02/02/1995] [Accepted: 03/01/1995] [Indexed: 11/16/2022]
Abstract
Cholecystokinin (CCK), one of the first discovered gastrointestinal hormones, which stimulates pancreatic enzyme secretion and induces gallbladder contraction, is one of the most abundant neurotransmitter peptides in the brain and is implicated in satiety via CCK-A receptors. We compared the suppressive effect of central administration of CCK on food intake in young and old rats. The suppressive effect on food intake was enhanced in old rats. To examine the mechanism of this enhanced suppression, we measured the mRNA levels of CCK, CCK-A and CCK-B receptors in the cerebral cortex and the hypothalamus of young and old male rats. The mRNA level of CCK-A receptors in the hypothalamus decreased with age, whereas the mRNA levels of CCK-B receptors in the hypothalamus and cerebral cortex did not. The mRNA level of CCK in the cerebral cortex decreased significantly in old rats, although the decrease in the hypothalamus was not significant. Therefore, the enhanced sensitivity to CCK of old rats could not be explained by changes in gene expressions of CCK and CCK receptors. Moreover, the effects of aging on the gene expressions of CCK-A and CCK-B receptors were different.
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Miyasaka K, Ohta M, Masuda M, Kawanami T, Matsumoto M, Funakoshi A. Sex difference in gene expressions of cholecystokinin (CCK) and CCK receptor in young and old rats. Arch Gerontol Geriatr 1995; 21:157-65. [PMID: 15374211 DOI: 10.1016/0167-4943(95)00635-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/1994] [Revised: 03/11/1995] [Accepted: 03/13/1995] [Indexed: 11/22/2022]
Abstract
The gene expressions of cholecystokinin (CCK) in the proximal small intestinal mucosa and CCK-A receptor in the pancreas were examined in male and female young (4-8 months old) and old (26-29 months old) rats. Their concentrations of CCK in the intestine were also compared. In males, but not in females, the mRNA levels of CCK in the intestine and those of the CCK-A receptor in the pancreas were significantly lower in old than young rats. In females, but not in males, the tissue content of CCK in the proximal intestinal mucosa was significantly higher in old rats. The pancreatic wet weight and trypsin activity in the proximal lumen were similar in young and old rats of both sexes. Therefore, changes in the regulations of gene expressions of CCK and the CCK receptor with age differ in male and female rats.
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Funakoshi A, Miyasaka K, Jimi A, Nakamura E, Teraoka H. Changes in gene expression of pancreatitis-associated protein and pancreatic secretory trypsin inhibitors in experimental pancreatitis produced by pancreatic duct occlusion in rats: comparison with gene expression of cholecystokinin and secretin. Pancreas 1995; 11:147-53. [PMID: 7479671 DOI: 10.1097/00006676-199508000-00006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Pancreatic duct occlusion is known to produce a sustained increase in the plasma cholecystokinin (CCK) concentration and to affect the tissue content of CCK in the rat. The tissue content of CCK is correlated with regenerative changes in the pancreas after pancreatic duct occlusion. In the present study, we examined the changes in mRNA levels of pancreatic secretory trypsin inhibitors (PSTIs), pancreatitis-associated protein (PAP), and amylase in the pancreas in comparison with changes in CCK and secretin mRNA levels in the intestine and the histological changes produced by pancreatic duct ligation. Rats with an internal bile fistula and with obstruction of pancreatic flow were prepared and were sacrificed 1, 3, 7, 10, 14, and 28 days later. Then mRNA levels of CCK, secretin, PSTIs, PAP, and amylase were determined by slot-blot analysis. The CCK mRNA level gradually increased to a peak on day 10, was slightly lower on day 14, and returned to the control level on day 28. The level of secretin mRNA did not change. The mRNA levels of PSTIs increased significantly on day 3 after occlusion. PAP mRNA was detectable on days 1 and 3, being maximal on day 1. The mRNA level of amylase was markedly decreased on days 1 and 3, then remained lower than the control level. Histological examination showed acute inflammatory changes in the pancreas on days 1 and 3 and regenerative changes from day 7. These results suggest that a change in gene expression of PAP reflects acute inflammatory changes in the pancreas most sensitively.
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Hu H, Takata M, Kusakawa I, Fujita M, Miyasaka K. Intratracheal administration of phosphodiesterase III inhibitor attenuates bronchoconstriction in cats: a preliminary report. Pediatr Pulmonol 1995; 19:360-4. [PMID: 7567216 DOI: 10.1002/ppul.1950190609] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effects of intratracheal administration of MKS 492, a selective phosphodiesterase (PDE) III inhibitor, were studied in five anesthetized bronchoconstricted cats. The animals were challenged by four repeated doses of intratracheal methacholine (67 micrograms/kg), and the degree of bronchoconstriction was assessed from increases in respiratory system resistance (Rrs). All animals demonstrated good bronchoconstrictive responses (i.e., 86-99% increases in Rrs) to methacholine without tachyphylaxis. On a separate day, the cats received the same four doses of methacholine after being pretreated with either intratracheal saline or three different doses of MKS 492 (0.17, 1.7, and 17 micrograms/kg). The increases in Rrs with 1.7 micrograms/kg [52.6 +/- 8.4% (SE)] and 17 micrograms/kg of MKS 492 (44.4 +/- 10.1%) were smaller than those with saline pretreatment (88.1 +/- 16.8%) (P < 0.05). There were no treatment-associated changes in mean arterial pressure or heart rate during administration of MKS 492. We conclude that intratracheal MKS 492 effectively reduced methacholine-induced bronchoconstriction in a dose-dependent fashion without substantial systemic effects. These preliminary results suggest that inhalation of isozyme-selective PDE inhibitors may deserve consideration for clinical trials provided that more extensive preclinical investigations justify such trials.
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Shirato H, Mizuta M, Miyasaka K. A mathematical model of the volume effect which postulates cell migration from unirradiated tissues. Radiother Oncol 1995; 35:227-31. [PMID: 7480826 DOI: 10.1016/0167-8140(95)01562-u] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
PURPOSE In order to simulate the large variation in tolerance doses for very small treatment volumes, we introduce a model which assumes the presence of cells which have migrated from unirradiated tissues. METHODS AND MATERIALS In order to represent serial architecture, the new model adds a new parameter to the familiar expression for serial architecture. Data derived from the model is fitted to the dose-response data developed by Hopewell et al. (Hopewell, J.W., Morris, A.D. and Dixon-Brown, A. The influence of field size on the late tolerance of the rat spinal cord to single doses of X rays. Br. J. Radiol. 60: 1099-1108, 1987) using white matter necrosis of rat spinal cord. RESULTS The new model with a cell-migration term more accurately describes the large differences in threshold doses for a very small treatment volume than a model without a cell-migration term. CONCLUSION Although these results do not prove that cell migration is the mechanism behind the volume effect for very small volume, they do suggest that the probability of normal tissue complication is more accurately predicted by the new model.
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Funakoshi A, Miyasaka K, Shinozaki H, Masuda M, Kawanami T, Takata Y, Kono A. An animal model of congenital defect of gene expression of cholecystokinin (CCK)-A receptor. Biochem Biophys Res Commun 1995; 210:787-96. [PMID: 7539259 DOI: 10.1006/bbrc.1995.1728] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Expressions of the CCK-A and B receptor genes in fetal and adult pancreas of OLETF rats were examined by the reverse transcriptase polymerase chain reaction followed by Southern blot hybridization. The pancreatic responses to various stimulants were examined in vitro and results were compared with those of control (LETO) rats. CCK-A receptor mRNA was not expressed in the fetal pancreas of either strain or in the adult pancreas of OLETF rats, but was expressed in the adult pancreas of LETO rats. CCK-B receptor mRNA was expressed in fetal and adult pancreas in both strains. Southern blot hybridization indicated a difference in gene structure in the two strains. The maximal effective concentrations of neuromedin C, carbachol, and secretin for amylase secretion and intracellular Ca2+ movement stimulated by carbachol and neuromedin C were similar in the two strains. CCK-8 and the non-sulfated form stimulated amylase secretion only in LETO rats. These results suggest that OLETF rats are a new model of a congenital defect of the CCK-A receptor gene and should be useful for determining CCK receptor function.
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Masuda M, Miyasaka K, Funakoshi A. Cholinergic stimulatory effect of intragastric administration of a prostaglandin E2 analogue on pancreatic exocrine secretion in conscious rats. Pancreas 1995; 10:395-400. [PMID: 7540761 DOI: 10.1097/00006676-199505000-00012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The effect of a long-acting, potent synthetic analogue of prostaglandin E2, enprostil, on pancreatic exocrine secretion was examined in conscious rats. Rats were prepared with cannulae draining bile and pancreatic juice separately. Pancreatic exocrine secretion was increased by intragastric administration of enprostil but inhibited by its intravenous administration. The pancreatic response to intragastric administration of enprostil was not inhibited by the administration of cholecystokinin antagonist or secretin antibody, or by bilateral vagotomy, but was completely abolished by atropine. Therefore, intragastric administration of enprostil seemed to stimulate pancreatic exocrine secretion via a peripheral gastro-(entero)-pancreatic reflex.
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Miyasaka K, Ohtake K, Nomura K, Kanda H, Kominami R, Miyashita N, Kitagawa T. Frequent loss of heterozygosity on chromosome 4 in diethylnitrosamine-induced C3H/MSM mouse hepatocellular carcinomas in culture. Mol Carcinog 1995; 13:37-43. [PMID: 7766309 DOI: 10.1002/mc.2940130107] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Genetic changes, in particular the loss of heterozygosity (LOH) and the presence of c-Ha-ras codon 61 point mutations, were investigated in diethylnitrosamine-induced hepatocellular carcinomas (HCCs) in C3H/MSM F1 mice. (MSM are wild mice.) LOH analysis of 48 primary tumors with microsatellite probes covering at least one proximal and one distal site of each autosome revealed no obvious positive results for LOH. Analysis of 23 cell lines established from seven of these HCCs, however, showed LOH on chromosome 4 in all (seven of seven), even in early passages (G2-G3). With regard to other chromosomes, LOH was observed only rarely on chromosomes 16 and 19. These allelotype features were maintained in later passages (G11-G14), with only a few additional occurrences of LOH appearing on chromosomes 1, 6, and 8. Extensive analyses with multiple microsatellite probes from chromosome 4 and with 52 cell lines established from 24 HCCs of 18 mice revealed LOH in 22 of the tumors (92%), with the shortest region about 10 cM distal to the alpha-interferon gene. No c-Ha-ras oncogene activation in codon 61 was observed. These data indicate that loss of tumor suppressor genes on chromosome 4 may play an important role in mouse hepatocarcinogenesis in progression in vivo or in immortalization in vitro or both.
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Maruyama K, Maruyama J, Yokochi A, Muneyuki M, Miyasaka K. Vasodilatory effects of ketamine on pulmonary arteries in rats with chronic hypoxic pulmonary hypertension. Anesth Analg 1995; 80:786-92. [PMID: 7893036 DOI: 10.1097/00000539-199504000-00024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To study the effects of ketamine on structurally remodeled pulmonary arteries from rats with hypoxic pulmonary hypertension (PH) and the effects of ketamine on endothelium-dependent and -independent relaxation, rats were exposed to hypobaric hypoxia (air at 380 mm Hg for 10 days). We measured the responses to ketamine, acetylcholine, and sodium nitroprusside (SNP) in prostaglandin F2 alpha-precontracted ring segments from a left extrapulmonary artery (EPA, 1.4-1.6 mm in outside diameter [OD] and an intrapulmonary artery (IPA, 0.7-1.1 mm OD) obtained from control and PH rats. The effects of acetylcholine and SNP were decreased in EPA and IPA rings from PH rats compared with control rings. In contrast, ketamine produced a greater relaxation response in rings from PH rats at 3 x 10(-5) -3 x 10(-4) in the EPA and at 10(-4) -10(-3) M in the IPA compared to control rings. A nitric oxide synthase inhibitor, nitro-L-arginine (10(-4) M), inhibited the relaxation in response to acetylcholine in both control and PH rats. Pretreatment with ketamine (10(-4) M) had no effect on the relaxation response to any concentration of acetylcholine or SNP in either control or PH rats. We conclude that nitric-oxide-mediated relaxation, but not ketamine-induced relaxation, was impaired in structurally remodeled hypertensive pulmonary arteries. Ketamine had no effects on nitric oxide-mediated relaxation in either normal or PH rats.
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Shinozaki H, Funakoshi A, Miyasaka K, Kitani K. Stimulatory effect of ursodeoxycholate on pancreatic exocrine secretion in an in vitro study. Pancreas 1995; 10:246-50. [PMID: 7542768 DOI: 10.1097/00006676-199504000-00005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Ursodeoxycholate (UDCA; 300 microM) significantly stimulates amylase secretion from isolated rat pancreatic acini but not Ca2+ mobilization. Removal of extracellular Ca2+ completely abolished the UDCA-stimulated secretory response. Ca ionophore (A23187) potentiated the response. However, staurosporine, a protein kinase C inhibitor, did not affect the UDCA-stimulated amylase secretion. These results indicated that UDCA directly acted on the pancreatic acini and stimulated amylase secretion by the mechanism of stimulation of influx of extracellular Ca2+, but not through inositol [1,4,5] triphosphate and diacylglycerol formation or Ca2+ mobilization.
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Takata M, Miyasaka K, Sakai H, Fujiwara H, Ito Y, Kawano T. Inhaled nitric oxide and extracorporeal membrane oxygenation in persistent pulmonary hypertension of the newborn. ACTA PAEDIATRICA JAPONICA : OVERSEAS EDITION 1995; 37:171-3. [PMID: 7793249 DOI: 10.1111/j.1442-200x.1995.tb03291.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Persistent pulmonary hypertension of the newborn (PPHN) may occasionally require an invasive treatment with extracorporeal membrane oxygenation (ECMO). Inhaled nitric oxide (NO) has recently been introduced as a selective pulmonary vasodilator for treatment of PPHN. We describe a case of PPHN in which neither inhaled NO nor ECMO was effective in reversing pulmonary hypertension. The clinical course of the patient suggested a potential role of NO inhalation in predicting the outcome of ECMO treatment for PPHN.
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Miyasaka K, Funakoshi A. Involvement of gene expressions of cholecystokinin and secretin in luminal feedback regulation in conscious rats. Pancreas 1995; 10:200-3. [PMID: 7716145 DOI: 10.1097/00006676-199503000-00015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Pancreatic exocrine secretion in conscious rats in regulated by bile and pancreatic juice in the proximal intestinal lumen; exclusion of bile and pancreatic juice produces release of cholecystokinin (CCK) and pancreatic hypersecretion (luminal feedback regulation). In the present study, we examined the changes of gene expressions of CCK and secretin, another representative gastrointestinal hormone in the intestine, and found that exclusion of bile and pancreatic juice significantly enhanced gene expressions of both CCK and secretin. These results suggested involvement of both CCK and secretin in luminal feedback regulation.
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246
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Funakoshi A, Miyasaka K, Kawanami T, Matsumoto M, Takata Y, Kono A. Effect of a cholecystokinin (CCK) antagonist (CR 1505) on gene expressions of CCK and secretin in rat intestine. Pancreas 1995; 10:118-22. [PMID: 7716134 DOI: 10.1097/00006676-199503000-00002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effects of intragastric administration of cholecystokinin (CCK) antagonist (CR 1505; 60-300 mg/kg/day) to rats for 3 days on the gene expressions of CCK and secretin, the plasma CCK immunoreactivity, and the CCK content in the intestinal mucosa were examined. CR 1505 increased the level of CCK mRNA in the intestine dose dependently to up to 1.6 times the level in control rats but did not affect the level of secretin mRNA. It also significantly increased the plasma CCK immunoreactivity and the amount of CCK extracted from intestine with acid dose dependently. CR 1505 tended to decrease the trypsin activity in the intestine. These results suggest that ingested CR 1505 increased the CCK mRNA level in the intestine.
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Nakakoshi T, Kajiyama M, Fujita N, Jong-Hon K, Takeichi N, Miyasaka K. Magnetic resonance imaging of Long-Evans cinnamon rats as a new model of hepatocellular carcinoma. Acad Radiol 1995; 2:50-2. [PMID: 9419524 DOI: 10.1016/s1076-6332(05)80246-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
RATIONALE AND OBJECTIVES Following hereditary hepatitis, Long-Evans Cinnamon (LEC) rats spontaneously develop hepatocellular carcinomas (HCC) histopathologically similar to human well-differentiated HCC. We demonstrated that LEC rats are an appropriate model of evaluating magnetic resonance (MR) imaging of well-differentiated liver tumors. METHODS Six 23-25-month-old LEC rats were studied using liver MR imaging and histologic observation. RESULTS Signal intensity of HCCs without cystic areas was normal or slightly high on T1-weighted images and slightly high on T2-weighted images. Histopathologically, most tumors resembled human highly or well-differentiated HCCs. CONCLUSION The LEC rat is a good model of investigating MR imaging of well-differentiated HCC.
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Suzuki T, Hirayama K, Kondo Y, Sakai H, Miyasaka K. [Adeno-tonsillectomy after cardiac transplantation in a child]. MASUI. THE JAPANESE JOURNAL OF ANESTHESIOLOGY 1995; 44:107-13. [PMID: 7699811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A case report of a boy who had a heart transplant at age one, and an adeno-tonsillectomy at age 2 years and 2 months, is presented. The patient showed severe episodic hypoxemia and poor weight gain (below 3 SD) due to upper airway obstruction caused by enlarged adenoids and tonsils. He was very active and no signs of congestive heart failure were noted. General anesthesia was induced with thiopental and maintained with a balanced anesthesia of nitrous oxide, oxygen, fentanyl, and vecuronium bromide. The heart rate did not increase with endotracheal intubation nor adenoidectomy but heart rate and blood pressure did increase slowly by the time the tonsillectomy was performed. Arrhythmia did not appear throughout the procedure and anesthesia was uneventful. A nasal endotracheal tube was kept in place for 4 days until surgical edema subsided. Respiratory inductive plethysmography performed before surgery and 2 days after extubation showed improvement of upper airway obstruction. The patient's blood concentration of cyclosporine fell briefly below the optimal level perioperatively due to unavailability of intravenous preparation in Japan. Various aspects of non-cardiac anesthesia for children who have experienced cardiac transplants are discussed.
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Kitani K, Senda M, Toyama H, Miyasaka K, Kanai S, Ohta M, Ivy GO, Koppang N. Decline in glucose metabolism in the brain in neuronal ceroid lipofuscinosis (NCL) in English setter--evidence by positron emission tomography (PET). Gerontology 1995; 41 Suppl 2:249-57. [PMID: 8821336 DOI: 10.1159/000213747] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Positron emission tomography scans were performed on brains of homozygous and heterozygous English setters with neuronal ceroid-lipofuscinosis (NCL) from 13 months of age to 24-25 months of age for homozygous dogs and to 38 months for heterozygous dogs, respectively. After iv injection of 18F-fluorodeoxyglucose (FDG), 7 coronal brain scans as well as sequential arterial blood samplings were performed for 45 min under pentobarbital anesthesia. From these data, three different functional images (DAR (standardized uptake value), FDG uptake (fractional uptake) and glucose uptake) were reconstructed and quantitatively analysed. In the age range from 13 to 15 months, glucose images were comparable for both homozygous and heterozygous dogs, so that no differentiation was possible between healthy and diseased dogs on the basis of PET findings. Between 18 and 24 months of age, a drastic decline in glucose metabolism was observed in homozygous dogs, while the decline in glucose utilization was very mild in this period for heterozygous dogs. Furthermore, in PET scans, cerebral atrophy and ventricular enlargement were clearly shown in homozygous dogs. Consequently at the age from 20 to 24 months, a clear differential diagnosis between healthy (heterozygous) and diseased (homozygous) dogs became possible even if the clinical symptoms were still not clear in the latter. We conclude that the biochemical alterations in the brain in canine NCL occurs and progresses very rapidly in the last quarter of their lives.
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Masuda M, Tomita H, Okubo K, Miyasaka K. Vagal efferent nerve-dependent inhibitory action of pancreatic polypeptide and peptide YY in conscious rats: comparison with somatostatin. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1994; 50:131-8. [PMID: 7884153 DOI: 10.1016/0165-1838(94)90003-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The release of pancreatic polypeptide (PP) and peptide YY (PYY) is regulated by the vagal nerve, and the inhibitory effect of these peptides on pancreatic exocrine secretion shows indirectly via a neural mechanism. To determine the role of the vagal nerve on the inhibitory action of these peptides on the pancreas, we compared the effect on the pancreatic response to bile and pancreatic juice diversion in conscious rats with and without vagotomy. We also studied this response in rats treated with capsaicin, because bile-pancreatic juice diversion is the most potent endogenous stimulation of pancreatic secretion in conscious rats. In addition, since somatostatin potently inhibits of pancreatic enzyme secretion, the effects of PP and PYY were compared with somatostatin. An intravenous infusion of 2.5 nmol/kg per h of PP and PYY significantly inhibited the pancreatic responses of bile and pancreatic juice diversion in animals with an intact vagal nerve and in those treated with capsaicin, whereas the same dose of peptides failed to inhibit pancreatic secretion in vagotomized rats. Somatostatin inhibited pancreatic secretion under all conditions tested. We concluded that the inhibitory action of PP and PYY on pancreatic secretion is fully mediated by the vagal efferent nerve although other multiple mechanisms are involved for the inhibitory action of somatostatin.
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