Biomedical subjects

M Minami

Publications and source records attributed to M Minami.

At least 163 records · Page 9Linked to original sources

PubMed1999

Results of surgical treatment of thymomas with special reference to the involved organs.

OBJECTIVE: The purpose of this study is to clarify the significance of the particular involved organ as a prognostic factor and its relation to other previously reported factors. METHODS: The prognoses of 194 consecutive patients with thymoma who had undergone complete or subtotal resection were reviewed retrospectively. Survival was evaluated as actuarial freedom from tumor death. Analysis of prognostic factors was performed by the Kaplan-Meier method with the log rank test and Cox's proportional hazards model. RESULTS: The Masaoka staging system and involvement of the great vessels were the independent prognostic factors in the entire study group; age, sex, histologic subtype, completeness of resection, association of myasthenia gravis, or involvement of other organs were not factors. The 10-year and 20-year survivals were 99% and 90% in stage I, 94% and 90% in stage II, 88% and 56% in stage III, 30% and 15% in stage IVa, 0% and 0% in stage IVb, 93% and 83% in the absence of involvement of the great vessels, and 54% and 20% in the presence of it. Involvement of the great vessels was also the single independent prognostic factor in the patients with stage III disease although completeness of resection or involvement of other organs were not. The 10-year and 20-year survivals in patients with stage III disease were 97% and 75% in the absence of involvement of the great vessels, and 70% and 29% in the presence of it. CONCLUSION: Although the Masaoka staging system is a valuable prognostic factor, the category of stage III is heterogeneous and consists of 2 groups with distinct prognoses depending on involvement of the great vessels.

Adolescent↗

PubMed1999

Plasma levels of nitric oxide and related vasoactive factors following long-term treatment with angiotensin-converting enzyme inhibitor in patients with essential hypertension.

Several mechanisms other than the inhibition of systemic and local formation of angiotensin II (Ang II) have been proposed to play a role in mediating the hypotensive effects of angiotensin-converting enzyme (ACE) inhibitors. In the present study, we measured plasma levels of nitric oxide (NO) and the related vasoactive factors bradykinin, 6-keto prostaglandin F1alpha (6-keto PGF1alpha) a stable metabolite of prostacyclin, and cyclic guanosine-3',5'-monophosphate (cGMP) before and after a 4-week treatment with the ACE inhibitor lisinopril in 17 patients with essential hypertension. Plasma NO levels were measured by the Griess method after conversion of nitrate to nitrite. Long-term lisinopril treatment significantly reduced blood pressure and increased plasma NO and 6-keto PGF1alpha. The treatment also tended to increase plasma levels of bradykinin and cGMP, but not to a significant extent. The posttreatment NO level was inversely correlated with posttreatment systolic, diastolic, and mean blood pressure (n = 17, r= -.68, P< .01, n = 17, r= -.54, P < .05, and n = 17, r= -.66, P< .01, respectively). The posttreatment bradykinin level was also modestly correlated with posttreatment systolic and mean blood pressure (n = 17, r = -.51, P < .05 and n = 17, r = -.55, P < .05, respectively). In contrast, posttreatment 6-keto PGF1alpha and cGMP levels were not correlated with posttreatment systolic, diastolic, or mean blood pressure. These findings raise the possibility that increased formation of NO and bradykinin, as well as inhibition of the renin-angiotensin system, contribute to the hypotensive effect of the ACE inhibitor observed in our hypertensive patients.

6-Ketoprostaglandin F1 alpha↗

PubMed1999

Interferon therapy lowers the rate of progression to hepatocellular carcinoma in chronic hepatitis C but not significantly in an advanced stage: a retrospective study in 1148 patients. Viral Hepatitis Therapy Study Group.

BACKGROUND/AIM: Hepatocellular carcinoma frequently develops during the advanced stages of chronic hepatitis C. We examined whether interferon prevents the development of hepatocellular carcinoma in chronic hepatitis C patients. METHODS: Japanese patients with chronic hepatitis C (n = 1.148; 117 with portal fibrous expansion (F1), 636 with bridging fibrosis (F2), 355 with bridging fibrosis and architectural distortion (F3)) and 40 cirrhotic (F4) patients were treated with interferon. These patients were followed from 1 to 7 years after interferon therapy. Blood tests and image analysis were serially performed to assess response to interferon and to detect hepatocellular carcinoma. Fifty-five cirrhotic type C patients (control F4) not receiving interferon were enrolled in this study. RESULTS: Sustained (SR: 27.5%) and transient (TR: 23.0%) responders totaled 50.5%, while 49.5% did not respond to interferon. SR showed an improvement in disease stage reflected by increased platelet counts. Fifty-two patients (9 F2, 36 F3, and 7 F4) developed hepatocellular carcinoma in the follow-up period; 3 SR, 8 TR, and 41 non-responders (NR). The cumulative incidence of hepatocellular carcinoma in F2 was significantly lower (p = 0.019) in SR compared with NR, but not in SR in F3 and F4 patients. However, the cumulative incidence of hepatocellular carcinoma was significantly decreased in all SR (p = 0.0001) and TR (p = 0.0397) compared with all NR. CONCLUSION: These results indicate that interferon therapy in chronic hepatitis C patients lowered the rate of progression of hepatocellular carcinoma in sensitive cases but not in patients in an advanced stage.

Adult↗

PubMed1999

Clinical spectrum of congenital cystic disease of the lung in children.

OBJECTIVES: Congenital cystic lesions of the lung are uncommon but share similar embryologic and clinical characteristics. The purpose of this study is to review our institutional experience of congenital cystic lung disease, emphasizing the clinical spectrum of the disease related to age, and present some cases with unusual clinical manifestations. PATIENTS: Between 1962 and 1996, 26 patients (9 females and 17 males) under 15 years old underwent evaluation and surgical treatment for congenital cystic lung disease. Seven patients were under 1 year old, and 19 were in over 1 year old. There were 13 bronchogenic pulmonary cysts, 6 pulmonary sequestrations, 4 congenital cystic adenomatoid malformations (CCAM), and 3 congenital lobar emphysemas. RESULTS: All patients under 1 year old showed respiratory distress with mediastinal shift but no episodes of infection. In contrast, 13 of the 19 patients over 1 year old had symptoms of recurrent infection without respiratory distress. Five patients over 1 year old were entirely asymtomatic from birth. There were significant differences (P < 0.05) in the frequencies of respiratory distress and infection between the two groups (chi2-test). Lobectomy was performed in 21 patients, excision in 3 patients, segmentectomy in one patient, and exploration in one patient. There was no incident of postoperative mortality or morbidity except for one patient with CCAM complicated by reexpansion lung edema. Twenty-one patients at long-term follow-up from 2 to 30 years after surgery are doing well with no subsequent limitation of physical activities due to lung resection. CONCLUSIONS: In patients under 1 year old, cystic lesions were discovered by respiratory distress; and in patients over 1 year old signs of infection were the most important clinical features. Early recognition of these relatively rare congenital cystic lung lesions would lead to the immediate, proper surgical intervention.

Adolescent↗

PubMed1999

Ventilatory muscle recruitment and work of breathing in patients with respiratory failure after thoracic surgery.

OBJECTIVES: Increased work of breathing (WOB) and respiratory muscle weakness have been identified as major causes of respiratory failure after thoracic surgery. This study was undertaken firstly to characterize the mechanical impairment in patients with respiratory failure after cardio-thoracic surgery, and secondly, to determine how diaphragmatic paralysis affects deterioration in the ventilatory mechanics. METHODS: We evaluated the respiratory mechanics of 24 patients following cardiac and thoracic surgery. Ten patients without respiratory problems were examined as control subjects. There were nine patients with phrenic nerve injury and five patients without phrenic nerve injury who required mechanical ventilation for more than 7 days. Phrenic nerve injury was assessed with a phrenic nerve stimulation test. We measured the respiratory variables, the esophageal, gastric and transdiaphragmatic pressure swing (deltaPes, deltaPga and deltaPdi, respectively), and the work of breathing during quiet tidal breathing. RESULTS: Both the groups requiring mechanical ventilation exhibited abnormally negative deltaPga/deltaPes values, compared with the control subjects. A significant increase in WOB with the normal generation of deltaPdi was seen in the patients without phrenic nerve injury. In contrast, the poor generation of deltaPdi with a slight increase in work of breathing was noted in patients with phrenic nerve injury. CONCLUSIONS: These results demonstrated two different types of respiratory failure in thoracic surgery patients, focusing on the impact of phrenic nerve paralysis. Diaphragmatic dysfunction should not be overlooked in postoperative care, and the amelioration of this compromise in respiratory mechanics is an important aspect of good patient management.

Adult↗

PubMed1999

Hsc70/Hsp40 chaperone system mediates the Hsp90-dependent refolding of firefly luciferase.

BACKGROUND: The 90-kDa heat shock protein, Hsp90, was previously shown to capture firefly luciferase during thermal inactivation, thereby preventing its irreversible off-pathway aggregation and maintaining it in a folding-competent state. However, subsequent refolding of the luciferase required addition of rabbit reticulocyte lysate. RESULTS: Here we demonstrate that Hsc70 (cytosolic Hsp70) and Hsp40/Hdj1 (cytosolic DnaJ homologue) are the effective components in a reticulocyte lysate, while other unidentified factor in the lysate is also required for the refolding of Hsp90-captured luciferase. Though another cytosolic DnaJ homologue, Hdj2/HSDJ, was more efficient than Hsp40 in suppressing the aggregation of rhodanese, Hdj2 was less effective for the refolding of luciferase than Hsp40. In the absence of the third factor, Hsp40 could bind to the luciferase captured by Hsp90, which suggested that Hsp40 on its own was able to bind the substrate protein, but Hsc70 could not. CONCLUSIONS: Hsc70, Hsp40 and at least another additional component in the reticulocyte lysate are necessary for full accomplishment of the refolding of Hsp90-captured luciferase. The third factor may be required for the loading of Hsc70 on to the substrate protein bound to Hsp90.

Animals↗

PubMed1999

Contribution of mast cells to the T helper 2 response induced by simultaneous subcutaneous and oral immunization.

This work examines the contribution of mast cells to the synergistic enhancement of the T helper 2 (Th2) immune response elicited following simultaneous oral and subcutaneous (s.c.) immunization. The s.c. route induced a Th1-biased immune response, characterized by increased interferon-gamma (IFN-gamma) and immunoglobulin G2a (IgG2a) antibody production. In contrast, oral immunization stimulated a primarily Th2-type response in which interleukin-4 (IL-4) and IgG1 antibody production were dominant. Simultaneous immunization also triggered a Th2-biased response, the magnitude of which exceeded the additive effects of s.c. and oral immunization alone by greater than threefold. To analyse whether mast cells in gut-associated lymphoid tissue contributed to this synergistic response, mast cell-deficient mice WBB6F1-w/wv were studied. Whereas the primary response following simultaneously antigen administration was reduced only twofold in these animals compared with wild type controls WBB6F1-+/+ (suggesting that mast cells were not needed to initiate Th2 immunity), reconstitution with bone-marrow-derived mast cells from WBB6F1-+/+ mice resulted in a superoptimal response (suggesting that mast cells contribute to the magnitude and perpetuation of these Th2-biased responses).

Administration, Oral↗

PubMed1999

Role of free radicals in the pathogenesis of lipid-induced glomerulosclerosis in rats.

BACKGROUND: We examined whether a high-cholesterol (HC) diet causes glomerulosclerosis in rats, and investigated the role of free radicals and lipid peroxidation in lipid-induced glomerulosclerosis. METHODS: The rats were given a normal diet, a HC diet, or a HC diet with antioxidants and radical scavengers. Serum levels of lipid, lipid peroxide (LOOH), urinary excretion of protein (UP), and urinary norepinephrine excretion (UNE) were measured. The glomerular sclerosing score was used to evaluate the renal injury. RESULTS: Blood pressure, total cholesterol, and LOOH were increased by a HC diet, as were UP and UNE. The HC diet induced renal injury. Treatment with superoxide dismutase, dimetylthiourea as a scavenger of hydroxyl radical (OH.), defferoxamine masilate as an iron chelator, or vitamin E inhibited the increases in blood pressure, LOOH, UP, and UNE, whereas total cholesterol was not affected. The production of superoxide anion (O2-.) by neutrophil and LOOH in the kidney was increased, and superoxide dismutase and hydrogen peroxide in the kidney were decreased. Almost all of these changes were attenuated by vitamin E; however, the O2-. production was not inhibited. OH. was increased by the HC diet, and it was normalized with the treatments. Furthermore, the sclerosing score was partially suppressed by the treatments. Ferric iron was stained in the proximal tubulus, and it was not observed in the treated rats. CONCLUSIONS: The data suggest that lipid peroxidation is involved in the pathogenesis of lipid-induced glomerulosclerosis and that O2-. and OH. may play a role in the process.

Animals↗

PubMed1999

Limited wrist fusions: comparison of results 22 and 89 months after surgery.

Limited wrist arthrodeses were performed to treat wrist diseases other than rheumatoid arthritis. The purpose of this study was to evaluate whether clinical and radiographic results noted 22 months after the procedure were maintained on re-examination an average of 89 months (range, 66-148 months) after the procedure. The study comprised 17 wrists. The average patient age was 42 years (range, 11-65 years). Two patients, both with Kienböck's disease, were lost to follow-up. Four radiocarpal and 11 intercarpal arthrodeses were performed. The range of motion between the first and second follow-up examination showed no significant difference. Grip strength likewise was nearly identical at both visits. At the last follow-up visit, progression of osteoarthrosis about the fusion area was noted in only 1 patient. These results suggest that the clinical and radiographic results at 22 months were maintained at the final follow-up visit and that the effect of limited wrist fusion does not deteriorate.

Adolescent↗

PubMed1999

Kinetics of cytokine production in the cornea and trigeminal ganglion of C57BL/6 mice after corneal HSV-1 infection.

To investigate the role of cytokines in the pathogenesis of acute herpetic keratitis (HK), we examined the kinetics of cytokine expression in the corneas and the trigeminal ganglia (TG) of C57BL/6Cr (B6) mice after herpes simplex virus type 1 (HSV-1) infection and observed the influence of the targeted disruption of interferon-gamma (IFN-gamma) gene on the clinical course of HK and/or viral clearance. Following corneal infection with HSV-1 Amakata strain, all corneas developed a typical dendritic keratitis. Quantitative analysis using enzyme-linked immunosorbent assay (ELISA) revealed that the expression of interleukin-1alpha (IL-1alpha), IL-5, IL-6, and IFN-gamma in corneas and TGs significantly elevated immediately after infection, peaked between days 2 and 7 postinfection (p.i.), and then diminished. One exception was IFN-gamma, whose expression significantly persisted in the TGs until day 30 p.i. An additional experiment using IFN-gamma-/- (gko) mice revealed that there was no significant difference in the peak level of viral replication in corneas and TGs between gko and B6 mice, although gko mice showed a significant delay of virus clearance in both corneas and TGs (p < 0.005) and higher mortality rate than B6 mice after HSV-1 infection (p < 0.01). These data suggest that the production of proinflammatory cytokines closely correlates with the pathogenesis of HK, and that IFN-gamma plays an important role in enhancing viral clearance from the cornea and TG.

Animals↗

PubMed1999

Survey of 222Rn concentrations in the air of a tunnel located in Nagano City using the solid-state nuclear track detector method.

The survey of 222Rn concentration in the air of tunnels constructed during World War II has been performed using a solid-state nuclear track detector technique. For the practical application of this technique to the determination of 222Rn concentrations in air, some basic properties were experimentally examined on the cellulose nitrate film, Kodak LR 115 type II. The calibration coefficient of the cellulose nitrate film used is determined from a correlation between the 222Rn concentration in air and the observed number of perforated etched tracks for widespread radon concentrations. The slope of the linear relationship observed yields a calibration coefficient of (0.00209 +/- 0.00018) tracks cm(-2) (Bq m(-3) h)(-1). From the survey of 222Rn concentration in the air of tunnels, the concentration of several thousand Bq m(-3) was observed at the inner most area of the tunnel, and the seasonal variation was clearly observed. The exponential distribution of radon concentration as a function of distance from the openings of the tunnel suggests that the radon concentration in the tunnel is basically governed by diffusion and mixing of radon gas with air.

Air Pollutants, Radioactive↗

PubMed1999

Pressor hyperreactivity to mental and hand-grip stresses in patients with hypercholesterolemia.

OBJECTIVE: To investigate the role of hypercholesterolemia in the regulation of blood pressure. SUBJECTS AND METHODS: We compared blood pressure responses to arithmetic stress and hand-grip tests in normotensive patients with hypercholesterolemia n = 15) and a mean (+/- SEM) age of 49 +/- 3 years, and normal cholesterolemic controls (n = 22) aged 48 +/- 1 years. Blood pressure and heart rate were measured throughout the tests. We examined the intracellular Ca2+ concentration in platelets with or without low-density-lipoprotein stimulation (2.9 nmol/l, 10 mg/ml). The plasma nitrite plus nitrate and cyclic GMP were determined before and at the end of each test to evaluate nitric oxide production and activity. RESULTS: Both tests showed that systolic/diastolic blood pressure was higher in the hypercholesterolemic patients than in the normal controls (stress test: 139 +/- 3/91 +/- 4 versus 127 +/- 2/80 +/- 3 mmHg, P < 0.01/P < 0.05; hand-grip test: 164 +/- 5/106 +/- 5 versus 144 +/- 3/88 +/- 3 mmHg, P < 0.01/P < 0.01). The intracellular Ca2+ concentration in platelets and the increase in response to low-density-lipoprotein stimulation were higher in the hypercholesterolemic patients (without stimulation: 72 +/- 3 versus 64 +/- 3 nmol/l, P < 0.01; with 2.9 nmol/l stimulation: 145 +/- 21 versus 89 +/- 6 nmol/l, P < 0.01). The increase in Ca2+ in response to 2.9 nmol/ml stimulation with low-density lipoprotein was positively related to the increase in mean blood pressure in response to the stress test (r = 0.56, P < 0.002). Nitric oxide production appeared to be increased in the hypercholesterolemic patients (65 +/- 5 versus 51 +/- 4 mmol/l, P < 0.05), and was not affected significantly by the tests. In contrast, cyclic GMP was lower in the patients and was increased significantly in the normal controls by the hand-grip test (P < 0.05). As a result, plasma cyclic GMP was lower in the patients (1.9 +/- 0.2 versus 2.5 +/- 0.1 nmol/l, P < 0.01). The ratio of plasma cyclic GMP to nitric oxide was also lower in the hypercholesterolemic patients at rest (P < 0.05), and at the end of the mental stress (P < 0.02) and hand-grip (P < 0.001) tests. CONCLUSIONS: Patients with hypercholesterolemia showed an exaggerated blood pressure response to both mental stress and exercise, even if resting blood pressure was normal. Increases in the intracellular Ca2+ concentration can contribute to these excessive responses. A disproportionately lower level of cyclic GMP to nitric oxide in plasma may also be involved in these abnormal responses.

Baroreflex↗

PubMed1999

Effects of alacepril and amlodipine on the renal injury induced by a high-cholesterol diet in rats.

BACKGROUND: A high-cholesterol (HC) diet increases blood pressure and induces renal injury in rats. We compared the effects of alacepril, an ACE inhibitor, and amlodipine, a Ca antagonist, on the renal injury induced by an HC diet in rats. DESIGN AND METHODS: Male Sprague-Dawley rats were given either an HC diet only (n = 5), an HC diet and amlodipine (n = 10) or an HC diet and alacepril (n = 10). The control rats (n = 5) were given a normal diet Systolic blood pressure (SBP) was measured by a tail-cuff method. Serum lipids, malondialdehyde (MDA) as a parameter for lipid peroxidation and urinary protein excretion were determined at 0, 4 and 8 weeks. The renal injury was evaluated histologically by the glomeruli sclerosing score. RESULTS: The HC diet increased SBP. Amlodipine lowered SBP more significantly than alacepril. Serum total cholesterol was increased by the HC diet and was not affected by either anti-hypertensive agent. HDL-cholesterol was similarly decreased in the three HC diet groups. Alacepril, but not amlodipine, completely attenuated the MDA elevation induced by the HC diet. Urinary protein excretion was decreased by the two anti-hypertensive agents at a similar rate. The renal histological injury assessed by the sclerosing score was ameliorated more significantly by alacepril than by amlodipine. CONCLUSIONS: Both amlodipine and alacepril decreased blood pressure and urinary protein, and ameliorated the renal injury induced by the HC diet in rats. The renal effect of alacepril seems to be mediated by the decrease in oxidative stress as well as by reduction of blood pressure, since alacepril lowered the sclerosing score more than amlodipine and completely attenuated MDA, although the blood pressure reduction by alacepril was less than that by amlodipine.

Amlodipine↗

PubMed1999

Serum levels of soluble tumor necrosis factor receptors and effects of interferon therapy in patients with chronic hepatitis C virus infection.

OBJECTIVE: The aim of this study was to understand the significance of the tumor necrosis factor receptor (TNFR)-mediated signaling pathway in the pathophysiology of chronic hepatitis C. METHODS: The serum levels of soluble TNFRs (sTNFRs; sTNFR p55 and sTNFR p75) were measured in 84 patients with chronic hepatitis C virus (HCV) infection (24 sustained responders and 25 nonresponders to interferon [IFN] therapy and 35 patients with persistent normal blood chemistries) and 20 healthy controls, then compared with clinical parameters. RESULTS: The serum levels of sTNFRs increased in proportion to the severity of liver disease. The levels of sTNFRs revealed significant correlations with the serum levels of alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, and gamma-globulin, but not with the serum levels of HCV-core protein. In the sustained responder group, the levels of sTNFR p75 showed a significant decrease (p < 0.0002) 1 yr after IFN therapy, although the levels of sTNFR p55 did not. The levels of sTNFR p75 were correlated with the serum levels of macrophage-colony stimulating factor both before and after IFN therapy. In the nonresponder group, the levels of both sTNFRs were unaltered after IFN therapy. CONCLUSIONS: The TNF alpha-TNFRs system, especially the TNFR p75-mediated pathway, is involved in the hepatic inflammation-fibrosis process in chronic hepatitis C. The serum levels of sTNFR p75, but not sTNFR p55, were correlated with the serum levels of macrophage colony stimulating factor in this process.

Adult↗

PubMed1999

[Analysis of intracellular calcium dynamics in enterochromaffin cells of small intestine].

Although serotonin (5-HT) release from enterochromaffin (EC) cells is considered to be regulated by multiple receptor-mediated mechanisms, little is known about the signal transduction. Here, we introduce the methods to isolate the mouse ileal crypts, which consist of various types of cells including EC cells, and to analyze the intracellular calcium dynamics. Ileal tissue was inserted with a plastic straw and the smooth muscle layers were peeled off. The mucosa were digested with collagenase and then suspended by moderate pipetting. Ileal crypts were separated by stepwise filtrations through 2 different nylon-meshes. The isolated crypt contained 0-3 EC cells as identified by immunostaining using anti-5-HT antibody followed by confocal microscopy. Isolated crypts were attached to a coverglass by an adhesive material (Cell-Tak) and loaded with fura-2/AM. Intracellular calcium dynamics in EC cells were obtained by digital video-imaging analysis of fura-2 fluorescence followed by the identification of EC cells with immunostaining of 5-HT granules. By these methods, it was suggested that norepinephrine elicited a transient elevation of intracellular calcium concentration in EC cells via alpha 2-adrenoceptors. These methods could be also useful to analyze the signal transduction system in intestinal endocrine cells that contain various intestinal hormones such as gastrin, cholecystokinin or secretin.

Animals↗

PubMed1999

[Effects of isatin, an endogenous MAO inhibitor, on dopamine (DA) and acetylcholine (ACh) concentrations in rats].

Isatin (indole-2,3-dione), an endogenous inhibitor of monoamine oxidase (MAO), has several physiological properties for stress and anxiety. We previously identified isatin in the brain of stroke-prone spontaneously hypertensive rats (SHRSP) using gas-chromatography mass spectrometry. This study elucidated the effects of isatin on the ACh and DA levels of brain tissues in rats. Furthermore, we evaluated the effect of isatin on DA levels in a rat model of Parkinson's disease induced by Japanese encephalitis virus. Striatal ACh and DA levels significantly increased at 2 hours after isatin (50-200 mg/kg, i.p.) administration. Perfused through a microdialysis probe, isatin (10(-6)-10(-4) M) also produced a significant and concentration-dependent increase in the ACh and DA concentrations in the perfusate from the rat striatum. Furthermore, urinary isatin concentrations in patients with Parkinson's disease tend to increase according to the severity of disease. Isatin (100 mg/kg, i.p.) significantly increased striatal DA levels in a rat model of Parkinson's disease. These results suggest that urinary isatin may become a diagnostic marker for the clinical severity of Parkinson's disease and that endogenous isatin, a new biological modulator, may play a role in the regulation of the brain levels of ACh by increasing the level of DA under stress.

Acetylcholine↗

PubMed1999

Sensitization of the adenylyl cyclase system in cloned kappa-opioid receptor-transfected cells following sustained agonist treatment: A chimeric study using G protein alpha(i)2/alpha(q) subunits.

Chronic and/or sustained opioid treatment has been shown to result in development of sensitization of the adenylyl cyclase (AC) system or cAMP overshoot. In this study, we investigated the molecular mechanism responsible for sensitization of the AC system using CHO cells co-expressing cloned kappa-opioid receptor and some chimeric G protein alpha(i2)/alpha(q) subunits. In CHO cells co-expressing the kappa-opioid receptor and pertussis toxin-insensitive chimeric alpha(i2)/alpha(q) subunits with alpha(i2) residues Met244-Asn331, despite pretreatment with pertussis toxin, acute treatment with the kappa-opioid-receptor-selective agonist U69,593 suppressed forskolin-stimulated cAMP accumulation, while sustained treatment with U69,593 (4 h) induced cAMP overshoot over the naive level by the kappa-opioid-receptor-selective antagonist norbinaltorphimine (sensitization of the AC system). On the other hand, in CHO cells co-expressing the kappa-opioid receptor and pertussis toxin-insensitive chimeric alpha(i2)/alpha(q) subunits without alpha(i2) residues Met244-Asn331, pretreatment with pertussis toxin completely blocked these acute and sustained effects of U69,593 on cAMP accumulation. These results suggested that the presence of the specific region of alpha(i2) (Met244-Asn331), which was reported to be responsible for the inhibition of AC, and continuous inhibition of AC by alpha(i2) is necessary for the development of sensitization.

Adenylate Cyclase Toxin↗

PubMed1999

[The relationship among subjective symptoms of fatigue, subjective fatigue feeling, and life habits of high school and college students].

The relationship among subjective symptoms of fatigue, subjective fatigue feeling, and life habits of high school and college students. The purpose of this study was to examine the relationship among subjective symptoms of fatigue (SSF), subjective fatigue feeling (SFF), life habits (behavioral patterns (BP) and life-style consciousness (LC)) in male students. A questionnaire on SSF, SFF, fatigue content, BP and LC was administered to 1802 male students aged 15-20 yr, and data from 1792 properly completed questionnaires was analyzed. The results were: 1) Students experience high SFF from daily activity. Students with a higher SFF tend to have more complaints of SSF, especially symptoms of languor, but the relationship between SFF and symptoms of irritation and physical disintegration are low. 2) Relationships between SFF and BP and LC are relatively low, except for physical condition. Even if the BP is successful, student's SFF is relatively high. 3) Subjective degree of health and physical condition relate highly to SSF. Exercise habits relate to loss of vigor, dietary habits to languor, loss of vigor, drowsiness and a decrease in concentration, and LC to SSF except for languor. It was inferred that SSF is influenced by BP and LC.

Adolescent↗