Search PubMed⌕ Search

Biomedical subjects

M Satoh

Publications and source records attributed to M Satoh.

At least 649 records · Page 36Linked to original sources
PubMed1993

Increased plasma endothelin-1 levels in patients with cirrhosis and esophageal varices.

We measured plasma levels of endothelin-1, a potent vasoconstrictor peptide, in 6 healthy controls and 20 patients with cirrhosis and correlated them with various clinical and laboratory parameters and other vasoactive substances. There was a trend toward increased endothelin-1 levels in patients with cirrhosis compared with controls (6.0 +/- 2.5 vs. 4.4 +/- 1.5 pg/ml, NS). The presence of ascites did not influence plasma endothelin-1 levels, and plasma endothelin-1 levels were not significantly correlated with serum albumin, serum bilirubin, or prothrombin time. Plasma endothelin-1 levels were significantly elevated in cirrhotic patients with esophageal varices compared with those without varices (7.5 +/- 2.5 vs. 4.5 +/- 1.6, p < 0.05). The elevation of endothelin-1 levels in patients with varices may represent a physiological compensation for the systemic vasodilation present in patients with liver cirrhosis and portal hypertension.

Endothelins↗
PubMed1993

Suppression of rabbit VX-2 subcutaneous tumor growth by gadolinium neutron capture therapy.

VX-2 tumors growing in hind legs of New Zealand White rabbits (n = 4) were exposed to thermal neutrons for 40 min (2.1 x 10(12) neutrons cm-2) while one of two hind leg tumors of each rabbit was infused continuously with meglumine gadopentetate through a branch of the left femoral artery. The contralateral (uninfused) tumors served as controls. Although no differential distribution of gadolinium was achieved between the tumor and its adjacent normal tissue, the gadolinium concentration in the infused tumor was approximately 5-6 fold higher than that in the contralateral tumor. Growth of gadolinium-infused tumors was significantly inhibited compared to that of control tumors (P < 0.05) between the 16th and 23rd days after treatment.

Animals↗
PubMed1993

Stroke and meningitis in a case of SLE with anti-phospholipid antibodies.

Anti-phospholipid antibodies (aPL) are concerned with many central nervous system diseases in systemic lupus erythematosus (SLE). However, no report has described the relationship between aseptic meningitis and aPL in SLE. We report a case of SLE with aPL, presenting cerebral infarction and aseptic meningitis. A 14 year old female with SLE with aPL experienced cerebral infarction and recurrent aseptic meningitis. Combination therapy with steroids and aspirin improved the condition and prevented relapses. The aPL are associated with cerebral infarction, even in young patients with SLE. In addition, aPL may induce aseptic meningitis in SLE.

Adolescent↗
PubMed1993

Macrophages in the urine in acute bacterial cystitis.

In the previous study in this series of studies concerning the role of macrophages in urinary tract infection, we attempted to detect macrophages in the urine of acute bacterial cystitis patients by nonspecific esterase staining of urinary sediment, however none of the leukocytes stained, probably because of cell damage caused by the urine and by centrifugation. In the present study, detection of macrophages in urine was again attempted, this time by prompt transfer of urinary leukocytes to culture medium after minimum centrifugation, 1 hr culture in a glass bottom chamber and non-specific staining of leukocytes adhering to glass. Macrophages in urine were detected by this method, and they comprised 5.9% of the adherent leukocytes, although macrophage spreading, which implies macrophage activation and is often seen in the early stage of nonbacterial prostatitis, was hardly ever observed. The percentages of adherent leukocytes were not correlated with urine osmolarity, probably because the effect of urine was minimized by prompt transfer of urinary leukocytes to culture medium after the urine samples had been collected. There have been quite few studies involving culture of urinary leukocytes in the past. Our simple techniques, such as prompt transfer of urinary leukocytes to culture medium after centrifuging with minimum gravity and for a minimum period of time, appear to be useful in the study of urinary leukocytes using other cells which appear in urinary tract infection, as well as cytokines and antibiotics, to clarify cellular mechanisms of defenses in urinary tract infection.

Acute Disease↗
PubMed1993

Effects of posture on carbon dioxide responsiveness in patients with obstructive sleep apnoea.

BACKGROUND: It is well known that upper airway resistance increases with postural change from a sitting to supine position in patients with obstructive sleep apnoea (OSA). It is not known, however, how the postural change affects the ventilatory and occlusion pressure response to hypercapnia in patients with OSA when awake. METHODS: The responses of minute ventilation (VE) and mouth pressure 0.1 seconds after the onset of occluded inspiration (P0.1) to progressive hypercapnia (delta VE/delta PCO2, delta P0.1/delta PCO2) both in sitting and supine positions were measured in 20 patients with OSA. The ratio of the two (delta VE/delta P0.1) was obtained as an index of breathing efficiency. The postural changes in response to carbon dioxide (CO2) after uvulopalatopharyngoplasty (UPPP) were also compared in seven patients with OSA. RESULTS: There were no significant changes in the resting values of end tidal PCO2, P0.1, or VE between the two positions. During CO2 rebreathing, delta VE/delta PCO2 did not differ between the two positions, but delta P0.1/delta PCO2 was significantly higher in the supine than in the sitting position (supine, mean 0.67 (SE 0.09) cm H2O/mm Hg; sitting, mean 0.57 (SE 0.08) cm H2O/mm Hg), and delta VE/delta P0.1 decreased significantly from the sitting to the supine position (sitting, 4.6 (0.4) l/min/cm H2O; supine, 3.9 (0.4) l/min/cm H2O). In seven patients with OSA who underwent UPPP, delta VE/delta P0.1 improved significantly in the supine position and postural change in delta VE/delta P0.1 was eliminated. CONCLUSIONS: These results suggest that in patients with OSA the inspiratory drive in the supine position increases to maintain the same level of ventilation as in the sitting position, and that the postural change from sitting to supine reduces breathing efficiency. Load compensation mechanisms of patients with OSA appear to be intact while awake in response to the rise in upper airway resistance.

Female↗
PubMed1993

Dexamethasone modulation of ion transport and fluid movement across airway epithelium.

Electrolyte or fluid is secreted across airway mucosa by both superficial epithelium and submucosal glands. To understand the effect of glucocorticoid on fluid movement across airway mucosa, we examined the effects of dexamethasone (Dex) on bioelectric properties of canine and feline tracheal epithelium and on 22Na efflux from isolated feline tracheal submucosal glands. Potential difference (PD) and short-circuit current (SCC) across tracheal epithelium were measured using an Ussing chamber, and conductance (G) was calculated as the ratio SCC/PD. Isolated glands were loaded with 22Na, and the rate constant (RC) of Na2+ efflux was calculated by measuring the radioactivity of each effluent sample. After treatment with 10(-9) to 10(-5) M Dex for up to 6 h, the epithelium and isolated glands were stimulated with isoproterenol (ISP) and methacholine (MCh), respectively. Dex treatment did not alter significantly baseline values of PD, SCC, or RC. However, Dex treatment produced a dose-dependent attenuation of ISP-evoked epithelial PD and SCC and of MCh-evoked glandular RC. In canine epithelium, pretreatment with 10(-5) M Dex for 6 h reduced by 40% the ISP (10(-6) M)-evoked rise in PD and SCC, whereas G remained unchanged. After 10(-5) M Dex treatment for 6 h, MCh (10(-5) M)-evoked RC in isolated glands was significantly less than in control glands (MCh alone) by 23%. These findings suggest that glucocorticoid decreases the fluid secretion across the airway mucosa, especially when the mucosa are stimulated.

Animals↗
PubMed1993

Inflammatory endotracheal polyp resolved after antibiotic treatment.

We describe a rare case of asymptomatic inflammatory endotracheal polyp resolved by antibiotic treatment. Histological examination of biopsy specimens showed an inflammatory polyp consisting of fibrovascular stroma and sparse lymphocyte infiltration. The size of the polyp was unchanged during 3 months without any treatment and its etiology was unclear. Although a bacterial organism was never proven, the polyp decreased remarkably under treatment with an oral antibiotic (ciprofloxacin) and did not recur for 6 months. Antibiotic treatment may be of value for inflammatory tracheobronchial polyps in cases of unclear etiology.

Ciprofloxacin↗
PubMed1993

Orthodromic capture of the atrial electrogram during transient entrainment of atrioventricular nodal reentrant tachycardia.

BACKGROUND: The reentry circuit of atrioventricular nodal reentrant tachycardia (AVNRT) has not been fully demonstrated. We hypothesized that if an upper common pathway was present, the atrial electrogram could not be captured orthodromically during transient entrainment of AVNRT by rapid atrial pacing. Based on this hypothesis, the presence of an upper common pathway was investigated. METHODS AND RESULTS: The atrial electrogram at the recording site of the His bundle potential was identified during induced AVNRT in 9 patients. To entrain AVNRT transiently, rapid pacing from the high right atrium and coronary sinus was applied at a cycle length 10 milliseconds shorter than that of AVNRT and repeated after a decrement of the paced cycle length in steps of 5 milliseconds until AVNRT was interrupted. In 5 of 7 patients, orthodromic capture of the atrial electrogram at the recording site of the His bundle potential was observed during transient entrainment of AVNRT by coronary sinus pacing, ie, the first postpacing interval of the atrial electrogram at the recording site of the His bundle potential was the same as the paced cycle length. In these 5 patients, the mean minimum paced cycle length capable of orthodromic atrial capture was 349 milliseconds, and the mean difference from the cycle length of AVNRT was only 16 milliseconds. During transient entrainment of AVNRT by high right atrial pacing, the atrial electrogram could not be captured orthodromically. CONCLUSIONS: Observation of orthodromic capture of the atrial electrogram at the recording site of the His bundle potential by coronary sinus pacing ruled out the presence of an upper common pathway in AVNRT, and the concept that perinodal atrial tissue is involved in the reentry circuit of AVNRT was supported.

Atrial Function↗
PubMed1993

Role of chemical drive in recruiting upper airway and inspiratory intercostal muscles in patients with obstructive sleep apnea.

Upper airway dilating muscle activity increases during apneic episodes in patients with obstructive sleep apnea (OSA). To elucidate the relative contribution of chemical and nonchemical stimuli to augmentation of the upper airway dilating muscle, we measured the response of genioglossus muscle (GG) and inspiratory intercostal muscle (IIM) activities to obstructive apnea during non-REM sleep and compared them with the response to progressive hypoxia and hypercapnia during awake periods in seven male patients with OSA. GG EMG was measured with a wire electrode inserted percutaneously, and IIM EMG was measured with surface electrodes placed in the second intercostal space parasternally. Responses to hypoxia and to hypercapnia were assessed by rebreathing methods in the supine position while awake. Following these measurements, a sleep study was conducted with the EMG electrodes placed in the same locations. The relationship between GG and IIM activities during the cycle of apnea and postapneic ventilation in non-REM sleep was quasi-linear, and the slope of the regression line was significantly greater than those during progressive hypoxia and progressive hypercapnia. The amplitude of GG activity at 70% of maximum IIM activities in the hypoxic test was 140 +/- 20% (mean +/- SEM) during non-REM sleep, which was also significantly greater than that during hypoxia (51 +/- 10%) and that during hypercapnia (59 +/- 15%). These results suggest that nonchemical factors contribute considerably to augmentation of GG activity during obstructive apneic episodes. The nonchemical stimuli may arise from mechanoreceptors activated by upper airway obstruction and behavioral factors associated with change in sleep states.

Adult↗
PubMed1993

Leiomyosarcoma of the inferior vena cava causing Budd-Chiari syndrome--a case report.

A forty-eight-year-old Japanese woman with leiomyosarcoma of the inferior vena cava presenting as Budd-Chiari syndrome is reported. A large tumor originating from the venous wall grew into the lumen, obstructing the hepatic vein, and extended up to the right atrium. Although this is a very rare tumor, care should be taken in order to make an early diagnosis and manage the condition effectively.

Budd-Chiari Syndrome↗
PubMed1993

Human mammary epithelial cells undergo squamous differentiation in serum-free three-dimensional culture upon loss of growth activity.

Normal human mammary epithelial cells (HMEC) isolated from surgically resected breast tissues were cultured under serum-free conditions using MCDB 170 medium. With the increase in the number of passages, in particular after the 5th passage, the number of enlarged, flattened and vacuolated cells increased while cell proliferation decreased. The senescent cells occasionally had keratohyaline granules in the cytoplasm and were positive in immunohistochemistry for keratinizing squamous epithelium-specific cytokeratin 10. When HMEC were cultured between floating double-layered collagen gels, the cells lost growth activity, showed marked stratification, and became positive for carcinoembryonic antigen (CEA). The stratified cells underwent squamous differentiation and tonofilament bundles appeared around the nuclei. The stratification and squamous differentiation of HMEC were observed within seven days after transfer to the three-dimensional culture, regardless of the number of passages. These results indicate that the HMEC in vitro ultimately differentiate into squamous epithelia and also that there is a close relationship between the squamous-type differentiation and the loss of cell proliferation.

Breast↗
PubMed1993

Pharmacological evidence for involvement of excitatory amino acids in aversive responses induced by intrathecal substance P in rats.

Rats given an intrathecal injection of substance P (0.3-10 nmol) or any of the excitatory amino acid agonists, N-methyl-D-aspartate (NMDA, 1-10 nmol), kainate (1 and 3 nmol) or alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA, 0.3-3 nmol), showed biting or licking the hind paws, scratching with the hind paws (only after substance P) and vocalization (only after excitatory amino acid agonists). The intrathecal co-administration of the NMDA antagonist, 2-amino-5-phosphonovaleric acid (APV, 10 nmol), inhibited behavioral responses to NMDA (10 nmol) and substance P (10 nmol) but not to kainate (3 nmol). Co-administration of the non-NMDA antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 10 nmol), suppressed responses to kainate (3 nmol), AMPA (3 nmol) and substance P (10 nmol) but not to NMDA (10 nmol). Co-administration of the substance P antagonist, CP-96,345 (3 nmol), inhibited the behavioral responses to substance P (10 nmol), but not to NMDA (10 nmol), kainate (3 nmol) and AMPA (3 nmol). The results suggest that the aversive behavior induced by intrathecal NMDA and non-NMDA agonists is mediated by activation of the corresponding glutamate receptors, but not by NK-1 receptors, and that the behavioral action of intrathecal substance P is mediated not only by direct activation of NK-1 receptors but also indirectly by NMDA and non-NMDA receptors for glutamate.

2-Amino-5-phosphonovalerate↗
PubMed1993

[Drug-receptor interactions in single smooth muscle cells].

Smooth muscle tissues were contracted by excitation of each muscle cell. Single cells prepared from guinea pig taenia caecum and trachea were contracted by extracellular application of acetylcholine and/or carbachol, whose concentrations were the same as those in the tissues. The concentration-response curve was shifted in a parallel fashion by competitive antagonists. The pA2-values of the antagonists were in good agreement with those estimated using the intact tissue. The apparent dissociation constants of cholinergic drugs estimated from inhibition of the specific binding of [3H]QNB (quinuclidinyl benzilate) to the single cells by the cholinergic drugs were also in agreement with the values in other membrane preparations. Similar findings were obtained in the single cells, microsomal fractions and isolated tissues from the guinea pig tracheal smooth muscles. In rabbit aortic single cells, the existence of two pharmacologically distinct alpha 1-adrenoceptor subtypes, alpha 1A and alpha 1B, in vascular smooth muscle cells was supported. Furthermore, the amount of prostaglandin F2 alpha released from guinea pig tracheal single cells was increased through activation by alpha 2-adrenoceptor agonists. The amount of prostaglandin F2 alpha released by norepinephrine decreased with age, while the total amount of alpha 2-adrenoceptors and the dissociation constants of the alpha 2-adrenergic drugs from the receptor did not change. The relaxation induced by beta-adrenoceptors did not alter with age. The total amount of beta-adrenoceptor and the dissociation constants of beta-adrenergic drugs from their receptor did not alter with age. An excellent relationship between the potency of isoprenaline and the maximum binding of [3H]dihydroalprenolol estimated in the single cells from 6- to 40-week-old guinea pigs was found, suggesting that the increase in the potency of isoprenaline is due to the increase in the maximum binding. The value in the single cells from 100-week-old guinea pigs deviated significantly from the regression line. This result suggests that the decrease in potency in the single cells from 100-week-old animals is due to a change in post beta-receptor processes in responsiveness. The smooth muscle single cells are useful for the study of drug-receptor interactions. Furthermore, post-receptor processes in responsiveness were discussed.

Acetylcholine↗
PubMed1993

[Transmission and modulation of nociceptive information in the spinal dorsal horn].

The roles of substance P (SP), somatostatin (SST), calcitonin gene-related peptide (CGRP), galanin and glutamic acid, which are contained in the primary afferents, in nociceptive transmission at the spinal dorsal horn are described. In the experiments using the in situ perfusion technique in a localized area of the rabbit spinal dorsal horn and radioimmunoassay, mechanical or thermal noxious stimulation of the skin, which did not produce severe inflammation like edema, selectively increased the release of immunoreactive SP or SST into the same perfusates, respectively. Intrathecal injection of synthetic SP or SST in rats selectively produced an hyperalgesia to mechanical or thermal noxious stimulation, respectively. Intrathecal injection of antibody against SP or SST in rats, particularly in rats with inflammation, inhibited the mechanically- or thermally-induced nociception, respectively. These data suggest that SP and SST separately play roles in transmission of mechanically and thermally induced nociceptive information, respectively. Furthermore, it was suggested that CGRP and galanin probably act on the capsaicin-sensitive primary afferents to increase the activated release of endogenous SP from their terminals, and consequently, processing of nociceptive information induced by mechanical stimulation of the periphery is enhanced in the spinal dorsal horn. Furthermore, our data suggest that CGRP facilitates processing of thermal nociception in the spinal dorsal horn, maybe through increasing the release of SST. On the other hand, endogenous glutamic acid probably mediates the aversive responses induced by intrathecal SP in rats.

Animals↗
PubMed1993

[Pharmacology of long-term potentiation].

The physiological characteristics and significance of long-term potentiation in the hippocampus were summarized. In particular, it was pointed out that different mechanisms are involved in the production of hippocampal LTP between the mossy fiber-CA3 system and other systems such as Schaffer collateral-CA1, fimbrial fiber-CA3 and commissural/associational fiber-CA3. Furthermore, the epsilon-subspecies of protein kinase C (PKC) was demonstrated to be exclusively located at the presynaptic terminals in the hippocampus and activated by arachidonic acid, and this enzyme is suggested to be involved in the production of LTP through a phosphorylation of GAP-43, while the gamma-subspecies of PKC may be postsynaptically involved in LTP through an activation of NMDAR1. The production of LTP in the hippocampus is facilitated by many factors such as epidermal growth factor, fibroblast growth factors, somatostatin, M1 receptor agonists and many drugs like anirasetam, bifemelane, idebenone, indeloxazine and vinpocetine, but inhibited by M2-receptor agonists, scopolamine and midazolam. In addition to electrophysiological methods, LTP-like phenomena in 2-deoxyglucose uptake and leucine incorporation can be detected. These LTP phenomena in several animal models will be useful as indices for evaluating facilitatory actions of various compounds on learning/memory functions.

Animals↗
PubMed1993

Chloroethylclonidine discriminates between alpha 1A- and alpha 1B-adrenoceptors in the presence of guanosine 5'-triphosphate in rabbit thoracic aorta.

Studies on the displacement of [3H]prazosin binding by the alpha 1-agonist phenylephrine revealed the presence of at least high- and low-affinity binding sites in membrane preparations prepared from rabbit thoracic aorta. Although the low-affinity site was reduced by the pretreatment of tissues with chloroethylclonidine, this site was unaffected by the same pretreatment of membrane preparations that did not contain the GTP analog. However, in membrane preparations with the metabolically stable GTP analog GTP gamma-S (10(-5) M) and single cell preparations, the low-affinity site was completely eliminated by the chloroethylclonidine pretreatment. Displacement studies with the alpha 1-antagonist WB4101 also revealed high- and low-affinity binding sites labeled by [3H]prazosin. Displacement curves of WB4101 obtained from membrane preparations in the presence of GTP gamma-S (10(-5) M) did not differ from those in the absence of GTP gamma-S. These results suggest that the low affinity phenylephrine binding site labeled by [3H]prazosin was selectively bound by the chloroethylclonidine used to pretreat the tissues, membrane preparation containing GTP gamma-S and single cells, and that chloroethylclonidine is able to recognize these two distinct subtypes of alpha 1-adrenoceptors only when GTP gamma-S is present.

Adrenergic alpha-Antagonists↗