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Biomedical subjects

T Kaneko

Publications and source records attributed to T Kaneko.

At least 199 records · Page 11Linked to original sources
PubMed2000

Helicobacter pylori infection produces expression of a secretory component in gastric mucous cells.

Helicobacter pylori infection induces the expression of a secretory component (SC) in gastric epithelial cells. We investigated the cell lineage of the SC- and immunoglobulin (Ig) A-expressing epithelial cells in H. pylori-infected gastric mucosa. Materials were obtained by means of gastric biopsy from H. pylori-infected patients (24 cases) before and after the eradication of H. pylori, from five normal uninfected volunteers, and from three gastrectomy cases. Acetic acid-ethanol-fixed and paraffin-embedded specimens were examined using histochemical staining for gastric mucins (periodic acid oxidation-thionine Schiff reaction-concanavalin A-horse radish peroxidase staining) by means of immunostaining for gastric mucins (45M1 and HIK1083), intestinal cells (MUC2 and CD10), Ki67, H. pylori, SC, and IgA. The SC and IgA were not found in normal gastric mucosa. The expressions of the SC and IgA in gastric surface mucous cells and mucous neck cells in the generating zone of the gastric mucosa of H. pylori-infected patients were significantly higher before eradication of H. pylori than after the eradication. These mucous cells have the potential for SC-mediated translocation of IgA into the gastric lumen, and this may act as part of the antibacterial defense system against H. pylori infection in the gastric generating zone.

Adult↗
PubMed2000

Rapid progression of intrahepatic cholangiocarcinoma after drainage of large cystic lesions: report of a case.

We report herein a case of cholangiocarcinoma with large cystic lesions. Computed tomography (CT) demonstrated large cysts in segment IV and the paracaval portion of the caudate lobe, and a solid tumor in the anterior segment of the right lobe of the liver which was contiguous to the cyst in the paracaval portion of the caudate lobe. The large cysts were diagnostically misleading and a liver abscess was suspected. Thus, percutaneous transhepatic drainage of the cyst was performed. The fluid in the cyst was negative bacteriologically, but malignant cells were detected. A CT scan done 2 weeks after drainage of the cyst showed progression of the solid tumor with intrahepatic metastasis and replacement of the cystic lesions by the solid tumor. Following percutaneous transhepatic portal embolization, a right hepatic trisegmentectomy with caudate lobectomy was performed. Pathological examination confirmed cholangiocellular carcinoma. These results indicate that drainage of the cystic lesion induced the tumor progression in the liver. Therefore, the possibility of cholangiocarcinoma with a large cystic lesion should be borne in mind when considering the differential diagnosis of a cystic lesion in the liver, and appropriate surgical therapy should be carefully selected.

Aged↗
PubMed2000

Formation of 8-oxo-2'-deoxyguanosine in the DNA of human diploid fibroblasts by treatment with linoleic acid hydroperoxide and ferric ion.

Lipid peroxides are suggested to be related to the occurrence of a variety of diseases including cancer and atherosclerosis. We examined whether lipid peroxides cause oxidative damage to DNA in intact cells. Linoleic acid hydroperoxide (LOOH) and ferric chloride were used at concentrations at which separate treatment had no effect on the formation of 8-oxo-2'-deoxyguanosine (8-oxodG) in DNA or the survival rate of cultured human diploid fibroblasts, TIG-7. The amount of 8-oxodG in the cellular DNA increased significantly when TIG-7 cells were treated concurrently with LOOH and ferric chloride. In a LOOH concentration-dependent manner 8-oxodG was formed. However, no significant induction of the activities of superoxide dismutases, catalase, or glutathione peroxidase was observed under these conditions. The formation of 8-oxodG by lipid hydroperoxides seems to be due to the generation of reactive species other than superoxide radicals and hydrogen peroxide. These results indicate that some species formed during the reaction of lipid hydroperoxides with ferric ion can cause oxidative damage to DNA.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2000

Hyaluronan in follicular fluids and fertilization of oocytes.

OBJECTIVE: To determine the concentrations of hyaluronan, E(2), and progesterone in follicular fluids (FFs) and the incidence of apoptotic granulosa cells. Also, to examine the relationship between the concentration of hyaluronan and follicular steroids, the incidence of apoptotic cells, and the fertilizability of the oocyte in the same follicle. DESIGN: Samples of 130 follicles were retrospectively analyzed for hyaluronan and steroids and the incidence of apoptotic cells. SETTING: The reproductive center in Yamagata University Hospital. PATIENT(S): Forty women infertile because of tubal damage or unknown causes undergoing IVF treatment were selected. INTERVENTION(S): The samples were collected from follicle aspirations. MAIN OUTCOME MEASUREMENT(S): The concentrations of hyaluronan and steroids in FFs, the incidence of apoptotic granulosa cells, and oocyte fertilizability. RESULT(S): The levels of hyaluronan in FF were found to correlate positively with P (r=0.444, P<0.0001) and the incidence of apoptotic cumulus granulosa cells (r=0.387, P=0.002) and inversely with E(2) (r = -0.601, P<0.0001) and free T (r = -0.344, P=0.001). The concentration of hyaluronan in FFs containing a subsequently fertilized oocyte after insemination was significantly lower than that in FFs containing a subsequently unfertilized oocyte (P=0.0005) (fertilized, 50.0 +/- 2.6 ng/mL; triploidy, 59.1 +/- 6.8; and unfertilized, 66.9 +/- 5.9). CONCLUSION(S): The concentration of hyaluronan in FF is an indicator for estimation of oocyte viability for fertilization.

Apoptosis↗
PubMed2000

Moderate and severe endometriosis is associated with alterations in the cell cycle of granulosa cells in patients undergoing in vitro fertilization and embryo transfer.

OBJECTIVE: To determine whether folliculogenesis is impaired in patients with endometriosis. DESIGN: Prospective study. SETTING: Yamagata University School of Medicine, Yamagata, Japan. PATIENT(S): Thirty women participating in an IVF program. INTERVENTION(S): The patients were divided into four groups according to the cause of their infertility: tubal factor (T), n = 7; male factor (M), n = 7; idiopathic (I), n = 7; and endometriosis (E), n = 9. Granulosa cells were obtained from the follicular fluid of each patient and analyzed by flow cytometry. MAIN OUTCOME MEASURE(S): The percentage of granulosa cells in each cell-cycle stage. RESULT(S): The mean (+/- SD) rate of apoptosis in the granulosa cells obtained from the patients with endometriosis was the highest among the four groups (T = 11.7% +/- 3.3%; M = 5.6% +/- 3.8%; I = 9.6% +/- 5.1%; and E = 18.6% +/- 9.6%). The percentage of S-phase granulosa cells was significantly higher in the patients with endometriosis than in all the other patients combined (E = 12.5% +/- 6%; T + M + I = 9.3% +/- 2.9%). The percentage of G2/M-phase granulosa cells was significantly lower in the endometriosis group than in the other three groups combined (E = 2.3% +/- 2.5%; T + M + I = 4.6% +/- 2.1%). CONCLUSION(S): Endometriosis impairs the cell cycle in granulosa cells. This phenomenon may have a detrimental effect on folliculogenesis.

Adult↗
PubMed2000

Relatively poor oocyte quality is an indication for intracytoplasmic sperm injection.

OBJECTIVE: To determine the relation between the insemination method used and the quality of oocytes and embryos. DESIGN: Prospective study. SETTING: Assisted reproductive centers at Yamagata University Hospital and Kuramoto Women's Clinic in Yamagata, Japan. PATIENT(S): Forty patients undergoing IVF and 40 patients undergoing intracytoplasmic sperm injection (ICSI). INTERVENTION(S): To estimate oocyte quality, the granulosa cells surrounding the oocyte were fixed and stained with a commercial dye in both groups of patients. One thousand granulosa cells were examined under a fluorescence microscope. MAIN OUTCOME MEASURE(S): The incidence of apoptotic granulosa cells surrounding each oocyte. RESULT(S): The incidence of apoptosis in the granulosa cells enclosing the oocytes that were fertilized by IVF was significantly lower than that in the oocytes that were fertilized by ICSI. Moreover, the incidence of apoptosis in the granulosa cells enclosing the oocytes that grew into good-quality or fair-quality embryos was significantly lower after conventional IVF than after ICSI. With ICSI, the incidence of apoptosis was not significantly different among the granulosa cells surrounding the oocytes that were inseminated, were fertilized, or developed into good-quality or fair-quality embryos. With IVF, the incidence of apoptosis was highest in the granulosa cells surrounding the oocytes that were inseminated and lowest in the granulosa cells surrounding the oocytes that developed into good-quality and fair-quality embryos. CONCLUSION(S): A good-quality oocyte is necessary for the development of a good-quality embryo with IVF but not with ICSI. Thus, relatively poor oocyte quality is a good indication for the use of ICSI.

Apoptosis↗
PubMed2000

Cerebellar hemorrhage after coil embolization for a ruptured vertebral dissecting aneurysm.

BACKGROUND: We present a case of ruptured vertebral dissecting aneurysm that exhibited cerebellar hemorrhage after successful embolization of the vertebral artery including the dissected site. CASE PRESENTATION: A 59-year-old man suffered a sudden onset of severe occipital headache when he looked up. Computed tomography demonstrated subarachnoid hemorrhage. Angiography revealed a right vertebral dissecting aneurysm distal to the posterior inferior cerebellar artery. Endovascular embolization of the aneurysm was performed with preservation of the posterior inferior cerebellar artery. The next day, the patient suffered a cerebellar hemorrhage in the vermis. The intracranial pressure was controlled by external ventricular drainage. The patient was discharged with mild cerebellar ataxia and bilateral abducens nerve palsy. CONCLUSION: In a case of vertebral dissecting aneurysm distal to the posterior inferior cerebellar artery, blood circulation in the vertebral arterial system may change after embolization of the aneurysm. In our case, the preserved posterior inferior cerebellar artery might have been hemodynamically stressed postoperatively, resulting in cerebellar hemorrhage. Therefore, strict control of blood pressure is essential in the acute stage after occlusion of the aneurysm.

Aneurysm, Ruptured↗
PubMed2000

The relationship between neurokinin-1 receptor and substance P in the medullary dorsal horn: a light and electron microscopic immunohistochemical study in the rat.

The synaptic relationship between substance P (SP) and its receptor, i.e. neurokinin-1 receptor (NK1R), was examined in the superficial laminae of the caudal subnucleus of the spinal trigeminal nucleus (medullary dorsal horn; MDH) of the rat. For confocal laser-scanning microscopy, double-immunofluorescence histochemistry for NK1 and SP was performed. In electron microscopic double-immunolabeling study, immunoreactivity for NK1R was detected with the silver-intensified gold method, while immunoreactivity for SP was detected with peroxidase immunohistochemistry. SP-immunoreactive axon terminals were observed to be in synaptic (mostly asymmetric) contact with NK1R-immunoreactive neuronal profiles in lamina I and lamina IIo. Although some SP-immunoreactive axon terminals were in synaptic contact with NK1R-immunoreactive sites of plasma membranes, NK1R-immunoreactivity was observed at both synaptic and non-synaptic sites of plasma membrane. Thus, SP released from axon terminals might not only act on NK1Rs facing the SP-containing axon terminals, but also diffuse in the extracellular fluid for distances larger than the synaptic cleft to act on NK1Rs at some distances from the synaptic sites.

Animals↗
PubMed2000

Serotonergic innervation of mesencephalic trigeminal nucleus neurons: a light and electron microscopic study in the rat.

Neurons of the mesencephalic trigeminal nucleus (MTN) are considered to be homologous to mechanosensitive neurons in the sensory ganglia. The sites of origin of serotonin (5HT)-immunoreactive axons on neuronal cell bodies in the MTN were studied in the rat by combining immunofluorescence histochemical techniques with retrograde tracing of Fluoro-Gold (FG) and anterograde tracing of biotin-conjugated dextran amine (BDA). The tracing studies, which were combined with multiple-labeling immunohistochemistry and confocal microscopy, indicated that 5HT-immunoreactive axon terminals on the cell bodies of MTN neurons originated from the medullary raphe nuclei, such as the nucleus raphes magmus (RMg), alpha part of the nucleus reticularis gigantocellularis (GiA) and nucleus raphes obscurus (ROb), as well as from the mesopontine raphe nuclei, such as the nucleus raphes dorsalis (DR), nucleus raphes pontis (PnR) and nucleus raphes medianus (MnR); mainly from the RMg, GiA and DR, and additionally from the ROb, PnR and MnR. The cell bodies in close apposition to 5HT-immunoreactive axon terminals were found through the whole rostrocaudal extent of the MTN. Electron microscopically a number of axon terminals that were labeled with BDA injected into the raphe nuclei were confirmed to be in asymmetric synaptic contact with the cell bodies of MTN neurons. It was also indicated that substance P existed in some of the 5HT-containing axosomatic terminals arising from the ROb, RMg and GiA. The present results indicated that proprioceptive sensory signals from the muscle spindles or periodontal ligament might be modulated at the level of the primary afferent cell bodies in the MTN by 5HT-containing axons from the mesopontine and medullary raphe nuclei including the GiA.

Animals↗
PubMed2000

Neurons in Golgi-stain-like images revealed by GFP-adenovirus infection in vivo.

Neurons in the adult brain have a very complex morphology with many processes, including tremendously long axons. Since dendrites and axons play key roles in the input and output of neural information, respectively, the visualization of complete images of these processes is necessary to reveal the mechanism of neural information processing. Here we made a recombinant adenovirus vector which encodes green fluorescent protein (GFP) tagged with a palmitoylation site, a membrane-targeting signal, produced specific antibodies to GFP, and used them as probes for staining the nervous system. In the neocortex, after injection of the recombinant virus and immunoperoxidase staining with the antibodies, many different types of cells were labeled in a Golgi stain-like fashion. Although the number of labeled cells varied depending on the amount of virus injected, the recombinant virus was considered to be infectious to cortical neurons of all cell types without selectivity. In contrast, the viral infection in the cerebellar cortex and superior cervical ganglion showed some selectivity toward the cell type. It is expected that this recombinant virus will be a useful tool for the morphological analysis of neuronal connections, especially the analysis of microcircuitry in the cerebral cortex.

Adenoviridae↗
PubMed2000

Intrinsic and commissural connections within the entorhinal cortex. An anterograde and retrograde tract-tracing study in the cat.

Intrinsic and commissural connections within the entorhinal cortex (EC) were examined in the cat by the anterograde and retrograde tract-tracing methods with Phaseolus vulgaris leucoagglutinin and cholera toxin B subunit. Intrinsic axons to the superficial layers (layers I-III) arose mainly from layers II, III, Vd (deep part of layer V), and VI, were distributed more widely in the superficial layers than in the deep layers, and terminated progressively more densely in more superficial layers; most densely in layer I. In the medial entorhinal area (MEA) and the ventromedial and the ventrolateral divisions of the lateral entorhinal area (VMEA and VLEA), the longitudinal connections through the intrinsic fibers to the superficial layers is often more restricted in rostral direction than in caudal direction. In the dorsolateral division of the lateral EC (DLEA), the longitudinal connections through the intrinsic fibers to the superficial layers extended distantly in both rostral and caudal directions. Intrinsic fibers to the deep layers (layers IV-VI) originated mainly from layers IV and Vs (superficial part of layer V) and were distributed rather sparsely and diffusely; they were distributed more widely in the deep layers than in the superficial layers. Commissural axons to the homotopic EC regions originated from layers II and III of the MEA and DLEA and terminated in all EC layers, most densely in layer I.

Animals↗
PubMed2000

Human autoreactive (Th0) CD4(+) T-cell clones with cytolytic activity recognizing autologous activated T cells as the target.

In attempt to obtain a clue to understanding possible physiological roles played by autoreactive T cells, autoreactive T-cell clones originally derived from an allogeneic mixed lymphocyte culture have been analyzed for their target spectrum, lytic function and cytokine profiles. Five CD4(+) T-cell clones established from allogeneic MLR, in which the stimulator cells shared certain class II MHC antigens with the responder, turned out to be reactive to autologous PBL. Among these, three clones were cytolytic against autologous B-cell line. These three cytolytic autoreactive clones were shown to be capable of specifically lysing autologous activated T cells expressing class II MHC molecules, raising possibility that such autoreactive clones might play a role in negatively regulating T cell responses. Cytolysis by an autoreactive clone 21C5 was inhibited completely by concanamycin A (CMA) known as a specific inhibitor of perforin, suggesting an involvement of the perforin/granzyme system. T-cell clones derived from the same MLC showed distinct correlation between their specificity and lymphokine profiles. Thus, the three cytolytic autoreactive clones belonged to Th0, whereas the two noncytolytic autoreactive clones belonged to Th2 and three alloreactive CD4(+) clones derived from the same culture were of Th1 type.

CD4-Positive T-Lymphocytes↗
PubMed2000

Antihyperalgesic effects of intrathecally administered magnesium sulfate in rats.

Intrathecal administration of MgSO(4) is reported to cause paralysis. However, the characteristic sensory disturbances have not been thoroughly investigated. We examined the effect of intrathecally administered MgSO(4) on the nociceptive threshold, using three different nociceptive measures, formalin test, hot plate test and paw pressure test in rats. The dose of MgSO(4) was 30, 100 or 300 microg. In acute nociceptive tests, intrathecal MgSO(4) did not cause any significant changes in the pain threshold. However, phase 2 of the formalin test was suppressed dose-dependently. It is known that spinal NMDA receptors are involved in the changes seen during the second (tonic) phase of the formalin test and in vitro studies showed that Mg(2+) can cause voltage-dependent blockade of NMDA receptor channel in the neurons of spinal dorsal horn. Thus, the suppressive effect of intrathecally administered MgSO(4) on the tonic inflammation-evoked behavior is mediated by the spinal NMDA receptors. Our results suggest that intrathecal administration of MgSO(4) may be therapeutically beneficial for patients with tonic pain involving the spinal NMDA receptors.

Animals↗
PubMed2000

A group of cortical interneurons expressing mu-opioid receptor-like immunoreactivity: a double immunofluorescence study in the rat cerebral cortex.

mu-Opioid receptor-expressing neurons in the rat cerebral neocortex were characterized by an immunolabeling method with an antibody to a carboxyl terminal portion of the receptor. They were small, bipolar, vertically elongated, non-pyramidal neurons, and scattered mainly in layers II-IV. We examined chemical characteristics of mu-opioid receptor-expressing neocortical neurons by the double immunofluorescence method. Almost all neuronal cell bodies expressing mu-opioid receptor-like immunoreactivity showed immunoreactivity for GABA, suggesting that they were cortical inhibitory interneurons. mu-Opioid receptor-immunoreactive neurons were further studied by the double staining method with markers for the subgroups of cortical GABAergic neurons. Immunoreactivities for vasoactive intestinal polypeptide, corticotropin releasing factor, choline acetyltransferase, calretinin and cholecystokinin were found in 92, 79, 67, 35 and 35% of mu-opioid receptor-immunoreactive cortical neurons, respectively. In contrast, less than 10% of mu-opioid receptor-immunoreactive neurons showed immunoreactivity for parvalbumin, calbindin, somatostatin, neuropeptide Y or nitric oxide synthase. Moreover, mu-opioid receptor-immunoreactive neurons very frequently exhibited preproenkephalin immunoreactivity, but not preprodynorphin immunoreactivity. The present results indicate that mu-opioid receptor-expressing neurons belong to a distinct subgroup of neocortical GABAergic neurons, because vasoactive intestinal polypeptide, corticotropin releasing factor, choline acetyltransferase, calretinin and cholecystokinin have often been reported to coexist with one another in single neocortical neurons. Methionine-enkephalin, which is a major product of the preproenkephalin gene, is known to be one of the most potent endogenous ligands for mu-opioid receptor. Thus, the expression of mu-opioid receptor in preproenkephalin-producing neurons suggested that mu-opioid receptor serves as an autoreceptor for the subpopulation of GABAergic interneurons at a single-neuron or population level.

Animals↗
PubMed2000

Divergence of glyceraldehyde-3-phosphate dehydrogenase isozymes in Saccharomyces cerevisiae complex.

Although sake yeasts are placed in Saccharomyces cerevisiae, we have been interested in their difference from the other subgroups of the species, and examined their proteins. When SDS-PAGE patterns of their soluble proteins were compared, specific differences between subgroups were found in their 36,000 Da regions. Proteins isolated therefrom were found to be subunits of three isomers of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from their N-terminal amino acid sequences and identified with anti-GAPDH serum. Therefore, comparison of zymogram was carried out by a modified method: denatured monomers were observed and the enzyme activity of their oligomers was not considered. SDS-PAGE patterns of all the sake yeasts differed from those of the other strains of S. cerevisiae. Strains of Saccharomyces bayanus showed uniform patterns which are different from the above two groups. Saccharomyces pastorianus strains resembled S. bayanus and were partly similar to S. cerevisiae in their patterns, in agreement with the hypothesis that S. pastorianus is a hybrid between these two species. Patterns of S. paradoxus appeared to be rather similar to those of sake yeasts. Results on the other species of the genus and on the preliminary experiments on PAGE of native isozymes are also described.

Alcoholic Beverages↗
PubMed2000

Propofol dosage achieving spontaneous breathing during balanced regional anesthesia with the laryngeal mask airway.

STUDY OBJECTIVE: To assess an anesthetic technique achieving spontaneous breathing through the laryngeal mask airway (LMA) during combined epidural block and propofol anesthesia. DESIGN: Prospective, consecutive case series study. SETTING: Operating room at a general hospital. PATIENTS: 112 ASA physical status I and II adult surgery patients; 32 patients for lower extremity surgery are enrolled into study 1, and 30 patients for lower extremity surgery and 50 patients for lower abdominal gynecology surgery are enrolled into study 2. INTERVENTIONS: In study 1, patients were given 1.5 to 2.0 mg/kg followed by a 3 mg/kg/h of infusion of propofol, after epidural block, and they were fitted with the LMA. Thirty minutes after induction, the dose of propofol was increased to 4, 5, 6, and 7 mg/kg/h every 15 minutes. In study 2, the patients were given 1.5 to 2.0 mg/kg and 5 mg/kg/h of propofol and the LMA insertion, after epidural block. MEASUREMENTS AND MAIN RESULTS: PaO(2)/FIO(2), PaCO(2), tidal volume or respiratory rate, blood pressure, heart rate, and eye opening and motor response scales in conformity with Glasgow coma scale were recorded. Study 1 suggested an induction dose of 1.5 to 2.0 mg/kg and an infusion of 5 mg/kg/h as an appropriate dose to preserve spontaneous breathing with the LMA and to maintain reasonable depth of anesthesia. Study 2 showed that respiratory and circulatory conditions, depth of anesthesia, and other data related to anesthesia were clinically acceptable. CONCLUSIONS: The best infusion dose of propofol to achieve spontaneous breathing with the LMA seems to be 5 mg/kg/h, and the present balanced regional anesthesia with the LMA, using propofol infusion at 1.5 to 2.0 mg/kg and 5 mg/kg/h combined with epidural block, may be useful in clinical practice for lower extremity and lower abdominal gynecologic operations.

Adult↗