Malignant peripheral nerve sheath tumor of the mediastinum.
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Biomedical subjects
Publications and source records attributed to M Satoh.
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The retina is protected from somatic circulation by the blood-retinal barrrier (BRB) composed of tight junctions between retinal vascular endothelial cells (the inner BRB) and those between retinal pigment epithelial cells (the outer BRB). Our recent studies showed that glial cell line-derived neurotrophic factor (GDNF) secreted from astrocytes regulates the permeability of the BBB. In the present study, we immunohistochemically examined the expression of GDNF, neurturin (NTN) and their receptors, GFRalpha1 for GDNF and GFRalpha2 for NTN, because the capillaries of the inner BRB show specialization very similar to the blood-brain barrier (BBB). GDNF and NTN were detected in glial fibrillary acidic protein (GFAP)-positive cells, including Müller cells. GFRalpha1 and GFRalpha2 were localized in von Willebrand factor-positive cells. GDNF and NTN enhanced the barrier function of endothelial cells derived from porcine brain cortex. These results strongly suggest that the barrier function of the BRB is regulated by GDNF and NTN secreted from glial cells, like the BBB.
This review summarizes our studies using pharmacological, neurochemical and molecular biological methods on the nociception in the CNS and opioid receptors (OPRs). We designed an in vitro fluorometric on-line monitoring system including an immobilized glutamate dehydrogenase column, and for the first time actually demonstrated that capsaicin induced the release of glutamate from rat dorsal horn slices containing the terminal area of primary afferents, in concentration-dependent, extracellular Ca(2+)-dependent and tetrodotoxin-resistant manners. Further, such a release was shown to be inhibited through mu- and delta-opioid receptors and alpha 2-adrenoceptors. On the other hand, we found that intracerebroventricular injections of interleukin (IL)-1 beta in rats produced biphasic effects on the mechanical nociception in rats (hyperalgesia in lower concentrations but analgesia in higher ones) and that similar injections of cytokine-induced neutrophil chemoattractant-1 (CINC-1) facilitated mechanical nociception in rats. The above described facts suggest that glutamate and some sorts of cytokines (IL-1 beta and CINC-1) contribute to nociception at least from the primary afferents to the spinal dorsal horn neurons and in higher brain, respectively. We have cloned rat kappa- and mu-opioid receptors. Using cloned cDNA for OPRs, we demonstrated (1) the distribution of mRNAs for OPRs in the rat central nervous system, (2) coexistence of each type of mRNA for mu-, delta- and kappa-OPRs and pre-protachykinin A mRNA in the dorsal root ganglion neurons, (3) an increased expression of mu- and kappa-OPR mRNAs in the I-II layers of rat lumbar dorsal horn with an adjuvant arthritis in the hind limb, (4) the inhibitions of N- and Q-types of Ca2+ channels by mu- and kappa-OPR agonists and (5) cross-desensitization of the inhibition through a common intracellular phosphorylation-independent mechanism, (6) pharmacological characterization of "antagonist analgesics" as partial agonists at every type of OPRs, and (7) the key-structure(s) of OPRs for discriminative binding of DAMGO to mu-OPR.
Chemokines constitute a large and still growing family of structurally-related small (8-10 kDa) cytokines that have chemotactic activity for leukocytes. Recently, some receptors for chemokines were reported to be used as a co-receptor by HIV at infection. In addition to their well-established role in inflammatory response and recently-reported role as a co-receptor for HIV, recent data suggest that chemokines and their receptors physiologically and pathologically play crucial roles as the mediators for intercellular communication among the cells intrinsic to and recruited into the brain; i.e., neurons, astrocytes, microglia, endothelial cells and leukocytes. Some chemokines such as SDF-1 and fractalkine are constitutively produced in the brain, implicating that they have an important role in maintenance of CNS homeostasis or determination of the patterning of neurons and/or glial cells in developing brain and normal adult brain. Chemokines such as MCP-1, MIP-1 alpha and CINC were shown to be induced by various neuroinflammatory stimuli, suggesting that they are involved in various neurodegenerative diseases such as multiple sclerosis, Alzheimer's disease, stroke and AIDS dementia syndrome. Chemokines and their receptors are potential targets for therapeutic intervention in neurodegenerative diseases.
We studied the mechanisms and characteristics of the spontaneously evoked intracellular Ca2+ changes (Ca2+ oscillations) in ileal longitudinal smooth muscle from guinea pig. Two-dimensional images of Ca2+ oscillations were obtained at 33-ms intervals with a Ca2+-sensitive fluorescence probe, fluo-3 using the intensified CCD camera. Nicardipine (10-7 M) significantly decreased the maximum level of fluorescence intensity of the Ca2+ oscillations, inhibited the frequency of the oscillations and tended to decrease the basal level of fluorescence intensity. However, tetrodotoxin (3 x 10-7 M) did not affect these oscillations. Phorbol 12,13-dibutyrate (10-7 M) significantly increased the maximum level of fluorescence intensity and the frequency of Ca2+ oscillations, and it changed them to steady and chronometric Ca2+ oscillations. Cyclopiazonic acid (3 x 10-5 M) also significantly increased the frequency of Ca2+ oscillations. Acetylcholine (10-8 M) increased the basal and maximum level of fluorescence intensity and the frequency of Ca2+ oscillations, and accelerated their onset. The increase of basal level of fluorescence intensity was then decreased by cyclopiazonic acid treatment. These results suggest that the augmentation of Ca2+ oscillations is mainly due to the activation of L-type Ca2+ channels, which is modulated by protein kinase C, and that the emptying of intracellular Ca2+ stores may activate the Ca2+ oscillations mediated through the increase of Ca2+ influx in ileal smooth muscle of guinea pig.
Endomorphin-1 is a novel endogenous peptide that is highly selective for the mu-opioid receptor over the delta- and kappa-opioid receptors. The structural basis of high selectivity of endomorphin-1 to the mu-opioid receptor was examined using chimeric receptors between mu- and delta-opioid receptors and those between mu- and kappa-opioid receptors. The chimeric receptors were constructed by using restriction enzyme sites intrinsically possessed by or introduced to the mu-, delta- and kappa-opioid receptor cDNAs. The junctions for the construction were located at the first intracellular loop (Bbs I site), third transmembrane domain (Afl III site) and fifth transmembrane domain (Bgl II site). The competitive binding assay using chimeric receptors revealed that the region from the Bbs I site to the Afl III site, including the first extracellular loop, contributes to the discrimination between mu- and delta-opioid receptors by endomorphin-1 more than any other regions. However, the region from the Afl III site to the Bgl II site and that from the Bgl II site to the carboxy terminal also somewhat contribute to the discrimination between mu- and delta-opioid receptors. For the discrimination between mu- and kappa-opioid receptors, two regions, that is, the region from the Bbs I site to the Afl III site and that from the Bgl II site to the carboxy terminal, were shown to be important. The present results show that endomorphin-1 discriminates the mu-opioid receptor from the other two types of opioid receptors by recognizing the differences in several amino acid residues widely distributed through the receptor structure. We previously reported that DAMGO, a synthetic highly mu-selective peptide, discriminates between mu- and delta-opioid receptors by recognizing the difference in only one amino acid residue and discriminates between mu- and kappa-opioid receptors by recognizing the difference in four residues localized in the restricted region. Although both endomorphin-1 and DAMGO are mu-opioid receptor selective peptides, molecular mechanisms for mu-selectivity are different between these peptides.
The anesthetic and cardiovascular effects of a combination of continuous intravenous infusion using a mixture of 100 g/L guaifenesin-4 g/L ketamine-5 mg/L medetomidine (0.25 ml/kg/hr) and oxygen-sevoflurane (OS) anesthesia (GKM-OS anesthesia) in horses were evaluated. The right carotid artery of each of 12 horses was raised surgically into a subcutaneous position under GKM-OS anesthesia (n=6) or OS anesthesia (n=6). The end-tidal concentration of sevoflurane (EtSEV) required to maintain surgical anesthesia was around 1.5% in GKM-OS and 3.0% in OS anesthesia. Mean arterial blood pressure (MABP) was maintained at around 80 mmHg under GKM-OS anesthesia, while infusion of dobutamine (0.39+/-0.10 microg/kg/min) was necessary to maintain MABP at 60 mmHg under OS anesthesia. The horses were able to stand at 36+/-26 min after cessation of GKM-OS anesthesia and at 48+/-19 minutes after OS anesthesia. The cardiovascular effects were evaluated in 12 horses anesthetized with GKM-OS anesthesia using 1.5% of EtSEV (n=6) or OS anesthesia using 3.0% of EtSEV (n=6). During GKM-OS anesthesia, cardiac output and peripheral vascular resistance was maintained at about 70% of the baseline value before anesthesia, and MABP was maintained over 70 mmHg. During OS anesthesia, infusion of dobutamine (0.59+/-0.24 microg/kg/min) was necessary to maintain MABP at 70 mmHg. Infusion of dobutamine enabled to maintaine cardiac output at about 80% of the baseline value; however, it induced the development of severe tachycardia in a horse anesthetized with sevoflurane. GKM-OS anesthesia may be useful for prolonged equine surgery because of its minimal cardiovascular effect and good recovery.
Renal cell carcinoma (RCC) is highly metastatic. We previously showed that expression of globo-series ganglioside is associated with the metastatic potential of RCC. However, the mechanism of metastasis remains largely unknown, and there is no effective therapy for metastasis. It was recently shown that induction of differentiation of colon cancer cells by brefeldin A was accompanied by an increase of GM3 with a concomitant decrease of neolacto-series gangliosides. To get a clue to a new method of therapy for RCC, we investigated whether the similar changes occur in RCC cells expressing globo-series ganglioside. Growth suppression and an increase of GM3 simultaneous with a decrease of monosialosyl galactosyl globoside, a member of globo-series gangliosides, were observed in human RCC cell line ACHN following brefeldin A treatment. The resultant change of the ganglioside profile is inversely related to the ganglioside pattern associated with the malignant potential of RCC and almost coincided with that representative of RCC cases showing favorable prognoses. It is suggested that the inverse relationship of expression between GM3 and globo-series ganglioside is reflected on the degree of malignancy of RCC, and may be useful as one of the indicators for exploiting treatment methods of RCC.
We previously isolated a mammalian gene STC1 that encodes a glycoprotein related to stanniocalcin (STC), a fish hormone that plays a major role in calcium homeostasis. However, the mammalian STC1 gene is expressed in a variety of adult tissues in contrast to fish where STC is expressed only in one unique gland, the corpuscles of Stannius. This suggested that STC1 may have wider autocrine/paracrine functions in mammals. In the present study, using immunocytochemistry, we showed that STC1 protein is localized in the developing bone and muscle of the mouse fetus. During endochondral bone formation, STC1 is found principally in prechondrocytes and prehypertrophic chondrocytes. During intramembranous bone formation STC1 is present in the mesenchyme that is about to undergo ossification. STC1 is also found in the myocardiocytes of the developing heart and at all stages of differentiation from myoblasts to myotube formation in developing skeletal muscle. The specific localization of STC1 to chondrocytes and muscle cells suggests a role for this protein in chondrogenic and myogenic differentiation.
Interleukin-6 (IL-6) has been thought to play a key role in the induction of hepatic metallothionein (MT) synthesis in tumor-bearing animals. In order to clarify the role of IL-6 and to distinguish its effect from those of other cytokines, we inoculated IL-6-null and B6J129Sv (wild-type control) mice SC with 1 x 10(7) Ehrlich carcinoma cells and examined tumor growth, hepatic MT, and serum cytokines. We have found that tumor growth was followed by an increase of hepatic MT in both IL-6-null and wild-type mice and that the two strains of mice had a similar hepatic MT induction followed by zinc accumulation in the liver. These results could be explained by our finding that tumor-bearing IL-6-null mice had a high level of tumor-secreted IL-6 in the blood. In conclusion, by utilizing tumor-bearing IL-6-null mice, we have demonstrated that IL-6 secreted from the tumor cells is responsible for the tumor-evoked increase of hepatic MT level.
Disialylgalactosylgloboside (DSGG), defined by monoclonal antibody RM2, is a renal cell carcinoma (RCC)-associated antigen which mediates adhesion of RCC TOS-1 cells to certain lung tissue target cells. This adhesion process may initiate preferential lung metastasis of RCC. Ganglioside GM3 is a B16 melanoma-associated antigen which similarly adheres to target cells and promotes consequent metastasis. In view of the close association of GM3-enriched microdomain with transducer molecules c-Src, Rho A, and FAK in B16 cells, we investigated the organizational status of DSGG in RCC cell line TOS-1, with the following results: i) DSGG, but not monosialylgalactosylgloboside, showed extensive clustering at the TOS-1 cell surface; ii) a low-density membrane fraction isolated from TOS-1 cells contained >95% of cellular DSGG, although protein content in this fraction was <1% of total cellular protein; iii) this fraction contained c-Src, Rho A, and FAK, but not H-Ras; iv) c-Src and Rho A were co-immunoprecipitated with DSGG through anti-DSGG mAb RM2 (IgM) affixed to a column. These observations indicate that DSGG is clustered in RCC, as typified by TOS-1 cells, to form a microdomain in which it is closely associated with c-Src, Rho A, and FAK, and may constitute a functional unit as has been observed for GM3 with transducer molecules in B16 cells. The functional organization of such units may be essential in determining malignant properties of RCC cells.
The feasibility of the complete systematic nodal dissection by the video-assisted thoracic surgery was prospectively assessed in 22 cases of clinical stage I lung cancer (16 right, 6 left cases). Resection of the designated lobe with the mediastinal lymph node dissection was carried out by the small thoracotomy with the aid of the thoracoscope, followed by the standard surgery to verify the completeness of systematic nodal dissection. Although residual lymph nodes were found in 14 of 22 cases, the residual rate was 2.9% and 2.7% by the number and 2.3% and 2.1% by the weight in right and left cases, respectively. Average time and hemorrhage for performing the procedure were 196 minutes, 216.7 minutes and 157.5 g, 145 g in right and left cases, respectively. As a consequence, sufficient systematic nodal dissection in lung cancer was suggested to be feasible by VATS lobectomy.
A 74-year-old man had an previous antero-septal and inferior myocardial infarction and an abdominal aortic aneurysm (AAA) 48 mm in diameter. Coronary angiography showed obstruction of the left anterior descending artery and of the right coronary artery, and 95% stenosis of the circumflex artery. The value of an ejection fraction of the left ventricle was 33%, measured by left venticulography. CABG and replacement of the aneurysm were performed simultaneously, because of the necessity of an intra-aortic balloon pumping (IABP) due to the impaired left ventricular function. First, CABG was performed under cardiac arrest. After declamping the ascending aorta, subsequently, replacement of AAA was performed while extracorporeal circulation (ECC) assisted heart beating. Weaning from ECC was smooth, and the operation was successful without using IABP. The patient was discharged 32 days after the operation. Consequently, cardiopulmonary bypass during AAA operation could decrease heart loads when hemodynamic states change in aortic clamping or after declamping. A simultaneous operation of CABG and AAA using ECC is safe and effective for impaired left ventricular function.
A 67-year-old man with liver cirrhosis and an icteric-type hepatoma involving the left main portal vein underwent left hepatic lobectomy after percutaneous transhepatic biliary drainage. Surgery was successful because of effective biliary drainage and meticulous assessment of liver function tests, including 99mTC-galactosyl human serum albumin scintiphotography.
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BACKGROUND: Our study was undertaken to check the discordance between findings from 99mTc-Sn colloidal reticuloendothelial scintigraphy (RESS) and 99mTc-GSA asialo-scintigraphy (GSA, a technique for evaluation of liver parenchymal cell density and function) and to analyze the discordance in relation to functional disturbances. We compared data between patients with alcoholic liver diseases (ALD) and patients with viral liver diseases (VLD). METHODS: The subjects of this study were 40 patients with chronic liver disease (17 with ALD and 23 with VLD). We used the liver uptake ratio of the tracer of the Sn colloid (SnL15, %), the liver uptake rate (GSAL15, %), and the Rmax (an indicator of total liver receptors) as indices of liver scans. RESULTS: GSAL15 was sometimes nondiscordant from SnL15. The patients were divided into two groups: the nondiscordant group (26 cases where the balance/sum of the two variables was <25%) and the discordant group (14 cases where the balance/sum was > or =25%). SnL15 was 41.6 +/- 16.2% in the nondiscordant group and 42.7 +/- 16.3% in the discordant group (p = 0.80). GSAL15 was 34.3 +/- 12.1% in the nondiscordant group and 21.5 +/- 8.1% in the discordant group (p = 0.001). Rmax was 0.33 +/- 0.17 in the nondiscordant group and 0.113 +/- 0.008 in the discordant group (p = 0.002). Thus, the SnL15, as determined by RESS, did not differ significantly between the nondiscordant and discordant groups, whereas GSAL15 was significantly unfavorable in the discordant group as compared with the nondiscordant group. SnL15 as determined by RESS did not differ significantly between the ALD group (40.4 +/- 18.7%) and the VLD group (43.5 +/- 15.0%) (p = 0.59), whereas Rmax as determined by GSA was significantly improved in the ALD group (0.34 +/- 0.20) compared with the VLD group (0.20 +/- 0.4) (p = 0.02). CONCLUSIONS: Liver cell function was lower in cases that showed discordance between liver cell function and reticuloendothelial function compared with cases without such discordance, although reticuloendothelial function did not differ between discordant and nondiscordant groups. Liver cell function was better in cases of ALD than in cases of VLD, whereas reticuloendothelial function did not differ between the ALD group and the VLD group.
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A 48-year-old man was treated with chemotherapy and irradiation therapy for superior vena cava syndrome (SVCS) caused by adenocarcinoma of the lung, and his symptoms subsided temporarily. However, the same symptoms recurred, and severe snoring during sleep and daytime hypersomnolence developed. Obstructive sleep apnea syndrome (OSAS) was diagnosed by respiratory inductive plethysmography. After chemotherapy, the symptoms of edema of the face and arms, snoring, and daytime somnolence tendency were alleviated, and the patient's apnea hypopnea index decreased remarkably. In addition, lateral cephalograms disclosed improved patency of the upper respiratory tract and dilation of the soft palate. These findings suggested a relationship between SVCS and OSAS. OSAS may cause a deterioration of circulatory dynamics and the quality of life when it develops secondary to SVCS. Therefore, it is necessary to determine whether OSAS is present and accordingly provide suitable treatment in patients with SVCS.