Antihypertensive effect of taurine on salt-induced hypertension.
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Animals↗
Biomedical subjects
H Itoh
Publications and source records attributed to H Itoh.
A method to quantitate cerebral blood flow using a rotating gamma camera and iodine-123 iodoamphetamine with one blood sampling.
A method has been developed to quantitate regional cerebral blood blow (rCBF) using iodine-123-labelled N-isopropyl-p-iodoamphetamine (IMP). This technique requires only two single-photon emission tomography (SPET) scans and one blood sample. Based on a two-compartment model, radioactivity concentrations in the brain for each scan time (early: t(e); delayed: td are described as: [formula: see text] respectively, where x denotes the convolution integral; Ca(t), the arterial input function; f, rCBF; and Vd, the regional distribution volume of IMP. Calculation of the ratio of the above two equations and a "table look-up" procedure yield a unique pair of rCBF and Vd for each region of interest (ROI). A standard input function has been generated by combining the input functions from 12 independent studies prior to this work to avoid frequent arterial blood sampling, and one blood sample is taken at 10 min following IMP administration for calibration of the standard arterial input function. This calibration time was determined such that the integration of the first 40 min of the calibrated, combined input function agreed best with those from 12 individual input functions (the difference was 5.3% on average). This method was applied to eight subjects (two normals and six patients with cerebral infarction), and yielded rCBF values which agreed well with those obtained by a positron emission tomography H2(15)O autoradiography method. This method was also found to provide rCBF values that were consistent with those obtained by the non-linear least squares fitting technique and those obtained by conventional microsphere model analysis. The optimum SPET scan times were found to be 40 and 180 min for the early and delayed scans, respectively. These scan times allow the use of a conventional rotating gamma camera for clinical purposes. Vd values ranged between 10 and 40 ml/g depending on the pathological condition, thereby suggesting the importance of measuring Vd for each ROI. In conclusion, optimization of the blood sampling time and the scanning time enabled quantitative measurement of rCBF with two SPET scans and one blood sample.
Aged↗
Treatment of choice for unresectable small liver cancer: percutaneous ethanol injection therapy or transarterial chemoembolization therapy.
Early detection of hepatocellular carcinoma (HCC) has become easier with recent advances in imaging diagnosis, but the tumor is frequently unresectable due to underlying advanced liver cirrhosis. In this study, we evaluated the therapeutic effect of percutaneous ethanol injection therapy (PEIT) and transarterial chemoembolization therapy (TACE) for small liver cancers measuring 3 cm or less in diameter and discussed the treatment of choice for unresectable cases. The tumors were divided into two groups on the basis of size: 1.5 cm or less (group A) and 1.6-3 cm in diameter (group B). In group A, the estimated 1- and 3-year survival rates were both 82% for a total of 19 cases. The survival value determined for 10 patients treated with PEIT was slightly higher than that found for 9 patients treated with TACE. In group B, the overall 1-, 2-, and 3-year survival values for a total of 56 patients were estimated at 83%, 60%, and 35%, respectively. The survival rates for 41 patients treated with TACE were 82%, 53%, and 28% at 1, 2, and 3 years, respectively. PEIT was performed on only 6 patients, whose survival rate was equivalent to that of a surgical resection group. The 1-, 2-, and 3-year survival rates for 9 patients who underwent surgical resection were estimated to be 100%, 85%, and 68%, respectively. Based on these results, PEIT seems to be the treatment of first choice for patients with small liver cancers measuring less than 1.5 cm in diameter if the tumor is thought to be unresectable because of associated severe liver cirrhosis. On the other hand, tumors measuring 1.6-3 cm in diameter must first be treated with TACE using a long-acting Lipiodol-carcinostatic suspension, even if resectable. In addition to the tumor size, dynamic CT is also useful for prospective decision of the therapeutic strategy. If the mass is demonstrated to be a hypervascular lesion by dynamic CT, TACE must be selected as the treatment of first choice, even for small lesions measuring 1.5 cm or less in diameter.
Aged↗
Regression of rectal polyps by indomethacin suppository in familial adenomatous polyposis. Report of two cases.
PURPOSE: The effect of indomethacin suppository on rectal polyps was evaluated in two patients with familial adenomatous polyposis who had undergone total colectomy and ileoproctostomy. METHODS: Both patients received intrarectal administration of 50 mg of indomethacin suppository once or twice daily to control the rectal remnant polyps. RESULTS: With this treatment, an almost complete regression was achieved within three months, in both patients. Polyps recurred after the interruption of indomethacin treatment in one patient. At the present follow-up of two to three years, no cancer has developed. CONCLUSIONS: Indomethacin suppository treatment was effective in controlling rectal remnant polyps in the two patients with familial adenomatous polyposis. Intraluminal administration of indomethacin in suppository form seems more beneficial since it allows for direct contact of the drug with the lesions and produces a high local concentration of the drug.
Adenomatous Polyposis Coli↗
Regulation of 60-kDa heat shock protein expression by systemic stress and 5-hydroxytryptamine in rat colonic mucosa.
Bowel dysfunction such as irritable bowel syndrome caused by stress is well described. Previous reports suggest that 5-hydroxytryptamine (5-HT) mediates alteration of bowel motility. In this study, the effects of water-immersion stress and the administration of 5-HT on the expression of a 60-kDa heat shock protein (HSP60) in rat colonic mucosa were investigated. The effect of YM-060, a 5-hydroxytryptamine 3 (5-HT3) receptor antagonist, on the expression of this protein was also studied. Water-immersion stress and the administration of 5-HT induced synthesis of HSP60 in rat colonic mucosa. The induction of HSP60 and the number of defecations were clearly inhibited by the oral administration of YM-060. Our results suggest that the induction of HSP60 in rat colonic mucosa by water-immersion stress may be associated with gastrointestinal motility mediated by 5-HT, especially via 5-HT3 receptors.
Animals↗
Heat shock protein 70 in rat liver with necrosis and regeneration induced by thioacetamide.
Heat shock protein (hsp), which changes both its concentration and localization in reaction to stresses such as heating, ischemia, etc., is thought to protect protein structure and act as a chaperone in intracellular transportation. We examined one of the hsps, hsp 70, in rat liver with necrosis and regeneration produced by thioacetamide (TAA). Hsp 70 was determined by immunoblotting and detected histologically by immunostaining, using a specific antibody. Generally, hsp 70 moves from the cytosol to the nucleus, where it concentrates 15 min after TAA injection. After 15 min, hsp 70 was not detected in the nuclei of hepatocytes around the central vein, where the hepatocytes later became necrotic. However, hsp 70 immunostaining was increasingly strong in the nuclei of hepatocytes around the portal area, which did not become necrotic. These findings show that, in acute necrosis, hsp 70 seems to correlate with nuclear protection or with the transportation of some protein from the cytosol to the nucleus. Hepatocytes probably neither survive nor regenerate without hsp 70 in their nuclei.
Animals↗
Induction of a 60-kDa heat shock protein in rat gastric mucosa by restraint and water-immersion stress.
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Animals↗
Induction of a 72-kDa heat shock protein in rat colonic mucosa by oral lavage solution.
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Administration, Oral↗
Accumulation of L-[2-(F-18)]fluorophenylalanine in peri-infarct area in a patient with acute cerebral infarction.
We studied the brain uptake of amino acid in a patient with acute cerebral infarction with L-[2-(F-18)]fluorophenylalanine and positron emission tomography. The increased accumulation of the ligand was specifically found in the peri-infarct area where oxygen metabolism was still maintained but decreased later in the 72-day follow-up period. The kinetic analysis revealed that increased accumulation was not due to increased transport from the blood to the brain but delayed washout from the brain to the blood. Although the mechanism is still unknown, abnormally high accumulation of L-[F-18]fluorophenylalanine may predict delayed neuronal changes after ischemic insults of the brain.
Aged↗
Induction of heat shock protein and prevention of caerulein-induced pancreatitis by water-immersion stress in rats.
Water-immersion stress is known to be involved in the development of hemorrhagic pancreatitis in caerulein-induced pancreatitis, when the stress is given following caerulein injection. The effects of pre-treatment with water-immersion to caerulein-induced pancreatitis were investigated in this study. 1. A 60-kDa heat shock protein was induced by pre-treatment with water-immersion stress in the pancreas. 2. Intra-peritoneal injection of caerulein (40 micrograms/kg) induced acute pancreatitis in rats without pre-treatment with water-immersion. However, when the rats were pre-treated with water-immersion, acute pancreatitis was not developed and no change of serum amylase levels was observed by i.p. injection of caerulein.
Amylases↗
Intimal hyperplasia of experimental autologous vein graft in hyperlipidemic rabbits with poor distal runoff.
Poor distal runoff and hyperlipidemia are factors affecting the fate of an implanted graft. In the present study, combined effects of poor distal runoff and hyperlipidemia on intimal hyperplasia (IH) of the vein graft were examined in a newly developed poor distal runoff model in rabbits. A poor distal runoff model was prepared in the right hindlimb of 30 rabbits. These animals were divided into two groups, depending on the diet provided; normolipidemic diet group (Group NL, n = 14) and hyperlipidemic 1% cholesterol diet group (Group HL, n = 16). Four weeks after preparing the poor runoff model, the femoral vein was implanted into the ipsilateral femoral artery. At 2, 4 and 6 weeks, the grafts were harvested. IH of the graft was measured and macrophages in the IH were examined immunohistochemically. Intimal cell proliferation was also determined by bromodeoxyuridine (BrdU) incorporation. IH of the vein graft was significantly accelerated in cases of poor distal runoff and hyperlipidemia. There were no macrophages in the IH in the NL group. In the HL group, macrophages infiltrated the outer layer of IH, sometimes just above the internal elastic lamina, and increased with time. In the poor distal runoff limbs at 6 weeks, macrophages also appeared in the subendothelial layer but were absent in that layer in the controls. Intimal cell proliferation expressed as the BrdU labeling index (LI) was maximum at 2 weeks. In the HL group, BrdU LI of IH in the poor distal runoff limb was higher than in the control at 2 and 4 weeks. Throughout the experiments, BrdU LIs in the HL group were significantly higher than in the NL. Hyperlipidemia accelerates intimal cell proliferation to a greater extent, then does IH. In cases of a poor distal runoff, the enhancement of cell proliferation by hyperlipidemia is augmented. These responses, in the presence of a hyperlipidemia, may be closely related to the migration of macrophages.
Animals↗
Urinary bladder dysfunction in spontaneously diabetic Chinese hamsters.
Urinary bladder dysfunction was investigated in spontaneously diabetic Chinese hamsters of the Asahikawa colony (CHAD). The wet weight of the urinary bladder was significantly increased in CHAD when compared with non-diabetic controls. In response to continuous infusion of physiological saline into the bladder under anesthesia, regular micturition was observed in controls. However, the threshold volume (i.e. the minimum volume at which rhythmic contraction appeared) was significantly increased and the amplitude of bladder contractions during micturition was decreased in CHAD aged 3-5 months (duration of diabetes, 0.6-2.2 months), leading to incomplete micturition. The frequency of micturition was also increased. Overflow incontinence was observed in all CHAD aged 13-15 months (duration of diabetes, 10-14 months). Acetylcholinesterase staining and activity in the urinary bladder walls were both significantly decreased in CHAD compared with controls. The in vitro increment of urinary bladder pressure caused by stimulation with bethanechol was not different between CHAD and controls. These findings suggest that CHAD have urinary bladder dysfunction which is caused by autonomic neuropathy and not by detrusor myopathy.
Acetylcholinesterase↗
Reciprocal activation and coactivation in antagonistic muscles during rapid goal-directed movements.
Seven normal subjects performed elbow extensions as rapidly as possible from an initial position to a visually defined target at 36 degrees in amplitude. In electromyograms, the reciprocal activation of the agonist and then antagonist bursts was always followed by simultaneous activation of the antagonistic muscles, i.e., coactivation. Instructions added to perform extensions "as rapidly as possible" changed coactivation; the command to "strongly fix the upper arm at the target" increased coactivation, whereas "relax immediately after the start of movement" made coactivation almost disappear. However, basic features of reciprocal activation remained the same. Other instructions given also changed coactivation on initiation and termination, while reciprocal activation was relatively unaltered. When subjects were encouraged to "relax immediately after the start of movement, but fix the upper arm quickly after attaining the target," coactivation initiated shortly after reaching the target (< 200 ms). Following the instruction to "relax the upper arm quickly after attaining the target," coactivation terminated rapidly after reaching the target (< 280 ms). The results show that instructions serve to change amplitude and timing of coactivation while keeping reciprocal activation relatively unaltered, suggesting that coactivation is controlled independently of reciprocal activation during rapid goal-directed movements.
Adolescent↗
Current topic: the role of amniotic endothelin in human pregnancy.
Endothelin (ET), a potent vasoconstrictor peptide, was originally isolated from culture medium of porcine aortic endothelial cells. Subsequently, ET was also reported to be produced by non-vascular tissues, and to be involved in various biological phenomena in these tissues. Recently, a high concentration of ET-1-like immunoreactivity (ET-1-LI) was detected in human amniotic fluid. Amnion tissue also contained a large amount of ET-1-LI, and cultured amnion cells secreted large amounts of ET-1-LI. The major component of ET-1-LI in these samples was ET-1. Moreover, the expression of prepro-ET-1 mRNA was detected in both amnion tissue and cultured amnion cells, indicating that ET-1 in the amniotic fluid originated from amnion cells. In addition, specific receptors for ET were detected in myometrium, decidua vera, chorion laeve and placenta, by both ligand binding analysis and Northern blot analysis. These findings suggest that ET-1 secreted from amnion cells plays a physiological role in human pregnancy. In this paper, the regulation of ET-1 production and expression of ET-receptors in avascular human amnion tissue are reviewed. The possible importance of amniotic ET in human pregnancy is also discussed.
Amniotic Fluid↗
Surgical strategy of concomitant abdominal aortic aneurysm and gastric cancer.
PURPOSE: Selecting the most appropriate surgical approach for patients with abdominal aortic aneurysm (AAA) and concurrent gastric cancer remains controversial. In an attempt to develop guidelines for the management of two concurrent lesions, a retrospective review of patients with concomitant AAA and gastric cancer was undertaken. METHODS: During the period from January 1985 to December 1992, a total of 222 patients with AAA were admitted to our hospital. Among these, seven patients (3.2%) had gastric cancer and concurrent AAA. Six of the seven patients were treated surgically for both lesions with either a one- or two-stage operation. One patient underwent only an exploratory laparotomy because of the peritoneal dissemination of the gastric cancer. Four of the six patients underwent a two-stage operation. In three cases, the resection of the malignancy was performed first because the gastric cancer was diagnosed as advanced before operation. In one case, the aneurysmectomy was performed first because the aneurysm was more than 6 cm in diameter and the gastric cancer was in an early stage of development. Two of the six patients underwent a one-stage operation and a simultaneous resection was carried out by way of segregated approaches, such as the retroperitoneal approach for AAA and the transperitoneal approach for the malignant lesion. RESULTS: Five of the seven patients (71.4%) are still alive. The length of follow-up for these patients ranged from 4 months to 4 years. CONCLUSIONS: The principles of our surgical approaches for concomitant AAA and gastric cancer are as follows. (1) The lesion that absolutely indicates urgent operation should be operated on first. (2) If the malignant lesion is advanced, it is resected first. (3) If the malignancy is not advanced, the AAA should be resected first by the retroperitoneal approach. (4) Simultaneous resection by way of segregated approaches is useful in some patients with early gastric cancer. (5) Both lesions must be resected eventually for improvement of the long-term survival chances.
Aged↗
Impaired vasodilation of peripheral arteries in response to acetylcholine in human beings with abdominal aortic aneurysm.
PURPOSE: Most aneurysms are generally presumed to be atherosclerotic in origin. Endothelium-dependent dilations were impaired in the cases of atherosclerosis. It is not clear whether the endothelial function of the peripheral arteries in humans with abdominal aortic aneurysm is impaired. The purpose of this study is to characterize endothelium-dependent relaxations in patients with abdominal aortic aneurysm. METHODS: Responses of external iliac artery blood flow to acetylcholine (30 micrograms/min: an endothelium-dependent vasodilator) and sodium nitroprusside (10 micrograms/min: a direct dilator of smooth muscle) were examined by electromagnetic blood flow meter in a group of 13 patients consisting of six patients with abdominal aortic aneurysm, six patients with colorectal cancer, and one patient with abdominal aortic aneurysm and rectal cancer. RESULTS: The mean blood flow before administration of drugs was comparable between the two groups. In the patients with abdominal aortic aneurysm, infusion of acetylcholine did not significantly increase the mean blood flow, whereas in the patients with colorectal cancer, acetylcholine increased the blood flow significantly. The increases of blood flow by an infusion of sodium nitroprusside were comparable between the two groups. In one patient with abdominal aortic aneurysm and rectal cancer, acetylcholine did not alter the blood flow, and sodium nitroprusside increased the blood flow, which was similar to what the patient with abdominal aortic aneurysm experienced. CONCLUSIONS: These results suggest that in patients with abdominal aortic aneurysm, the endothelium-dependent vasodilations of the peripheral artery were impaired without changing the smooth muscle property.
Acetylcholine↗
Natriuretic peptide-potentiating actions of neutral endopeptidase inhibition in rats with experimental heart failure.
We developed a rat model of heart failure induced by myocardial infarction (MI) which preserves responsiveness to exogenously administered natriuretic peptide, and investigated the potentiating action of neutral endopeptidase (NEP) inhibition on the renal response to endogenous natriuretic peptide in MI rats, comparing with that in the established cardiac-failing model with arterio-venous fistula (AVF). The endogenous plasma concentration of alpha-rat atrial natriuretic peptide (alpha-rANP) in the MI rat was 6.4-fold higher than that in the normal rat, and intravenous infusion of phosphoramidon (165 nmol/min/kg), an NEP inhibitor, induced larger increases in circulating alpha-rANP levels and natriuresis in MI rats than in normal controls. The maximal natriuretic effect of phosphoramidon (165 nmol/min/kg) was equal to that of exogenously administered alpha-rANP (100 pmol/min/kg) in MI rats, whereas plasma alpha-rANP concentration under NEP inhibition was much lower than that after administration of alpha-rANP. The endogenous alpha-rANP levels in AVF rats were as high as those in MI rats. However, the natriuretic effect of phosphoramidon was less in AVF rats than in MI rats, which was consistent with the decreased natriuretic activity observed with administration of exogenous to alpha-rANP in the AVF rat. These results indicate that the natriuretic effect of NEP inhibition is dependent on elevated endogenous alpha-rANP levels in cardiac-failing rats, but cannot be accounted for simply in terms of the increase in circulating alpha-rANP levels. Endogenous natriuretic peptide-mediated natriuresis under NEP inhibition also appears to correlate with the responsiveness to the exogenously administered peptide.
Animals↗
Pancreatic trypsinogen and cathepsin B in human pancreatic carcinomas and associated metastatic lesions.
Expression of pancreatic trypsinogen and cathepsin B in 23 surgically resected pancreatic ductal adenocarcinomas was evaluated immunohistochemically, using a monoclonal antibody against human pancreatic trypsinogen and a polyclonal antibody against human cathepsin B. Fifteen of 20 invasive tubular adenocarcinomas (75%) expressed pancreatic trypsinogen in a coarse granular pattern located in the supranuclear cytoplasm of the carcinoma cells. In addition, metastatic lesions, including those in peripancreatic lymph nodes and neural plexuses, expressed pancreatic trypsinogen. In contrast, three intraductal (non-invasive) papillary adenocarcinomas did not express pancreatic trypsinogen. Cathepsin B expression was recognised in 14 of 20 invasive tubular adenocarcinomas (70%) in a fine granular pattern located diffusely in the cytoplasm of the carcinoma cells, while none of the three intraductal papillary adenocarcinomas had detectable cathepsin B. These findings suggest that pancreatic invasive ductal adenocarcinomas express pancreatic trypsinogen and cathepsin B immunoreactive peptides, raising the possibility that pancreatic trypsinogen and cathepsin B may act independently of each other in the process of carcinoma invasion and metastasis, like other different classes of proteases involved in the proteolytic modification of the matrix barrier.
Adult↗