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Biomedical subjects

Hiroshi Yoshimura

Publications and source records attributed to Hiroshi Yoshimura.

At least 19 recordsLinked to original sources
PubMed2006

Specific expression of substance P in synovial tissues of patients with symptomatic, non-reducing internal derangement of the temporomandibular joint: comparison with clinical findings.

Our aim was to find out the extent of expression of substance P in synovial tissue from the human temporomandibular joints (TMJ) with symptomatic, non-reducing internal derangement, and to investigate the relationship between substance P and clinical findings. Fifty-four joints in 54 patients were examined immunohistochemically. Specimens of synovial tissue from 10 joints in 8 subjects with habitual dislocation of the TMJ with no pain were examined as controls. Cells that stained for substance P were found mainly among the endothelial cells in the blood vessels beneath the lining cells in synovial tissues from 47 of the 54 joints (87%) with internal derangement and from 5 of the 10 control joints. The extent score of cells that stained for substance P in joints with internal derangement was significantly higher than that in controls (p=0.02). The extent score of these cells did not correlate with pain in the joint or the degree of synovitis. These results suggest that substance P may have some roles in both the physiological and pathological conditions in patients with symptomatic internal derangement of the TMJ.

Adolescent↗
PubMed2006

Component-dependent urine responses in the rat accessory olfactory bulb.

To investigate how pheromonal information is processed in the rat accessory olfactory bulb, we optically imaged intrinsic signals to obtain high-resolution maps of activation induced by urinary stimulation. Application of volatile components in male urine mainly induced activation in the anterior accessory olfactory bulb, irrespective of the sex, whereas volatile female urine elicited activation not only in the anterior but also to some extent in the caudal part of the posterior accessory olfactory bulb of male, but not female, rats. Nonvolatile components of both male and female urine induced activation mainly in the rostral part of the posterior and to a lesser extent in the anterior accessory olfactory bulb, irrespective of the sex. These results indicate that volatile and nonvolatile urinary components activate the anterior and posterior subdivisions of the accessory olfactory bulb, respectively.

Animals↗
PubMed2006

Surgical treatment of superficial esophageal cancer.

OBJECTIVE: The worldwide incidence of superficial esophageal cancer (SEC) is increasing. The aim of this study is to review the systematic surgical outcomes of esophagectomy for SEC. DATA SOURCES: Only manuscripts written in English and written between 1980 and 2003 were selected from MEDLINE. The keywords consisting of superficial esophageal cancer, early esophageal cancer, and early stage or superficial stage or stage I in esophageal cancer were searched. STUDY SELECTION: There were no exclusion criteria for published information relevant to the topics. The most representative articles were selected when there were several articles from the same institution. Case reports were excluded. DATA EXTRACTIONS: Thirty-two manuscripts were finally collected from MEDLINE and eight articles were also added from reference lists of the pertinent literatures. In evaluating the statistical analysis of the complications of the reported literature, collective method was used. DATA SYNTHESIS: The collected information was organized. CONCLUSIONS: The conclusions drawn from those articles showed that the overall prevalence of SEC accounted around 10% and increased to 25% in the 2000s. The overall incidence of lymph node metastasis of SEC was about 25% and its incidences in mucosal and submucosal cancer were 5 and 35%, respectively. The percentage of the cases of squamous cell carcinoma (SCC) vs adenocarcinoma (AC) widely varied depending on the geographic locations reported; most SCC cases were from the Asian countries and most AC cases were from the European countries. Clinical significance of multimodal treatment for SEC has dramatically developed in the recent era and could provide various potential therapeutic options for SEC. These concepts make it possible to individualize surgical management of SEC as part of various multimodal treatments. The operative approaches for SEC varied from minimally invasive thoracoscopic esophagectomy, limited transabdominal distal esophagectomy, conventional transthoracic esophagectomy, transhiatal esophagectomy without thoracotomy, en bloc esophagectomy, and to extended esophagectomy with a complete three-field lymph node dissection. A 5-year overall survival rate of SEC after esophagectomy was good (46 to 83%) to excellent (71 and 100%) for mucosal SEC, but far from satisfactory (33 and 78%) for submucosal SEC. Early diagnosis, development of multimodal treatment, standardization of the surgical procedure including routine lymph node dissection, and improved perioperative management of patients have led to a better survival for patients with SEC.

Adenocarcinoma↗
PubMed2006

Synthesis of beta-analogues of C-mannosyltryptophan, a novel C-glycosylamino acid found in proteins.

alpha-C-Mannosyltryptophan (alpha-C-Man-Trp) has been found to be a novel post-translational modification of tryptophan found from some biologically important glycoproteins. In order to analyze the biological functions of alpha-C-Man-Trp, we have developed an efficient synthetic strategy for alpha-C-Man-Trp and its glucose and galactose analogues, starting from alpha-C-glycosidation of the corresponding hexapyranoside derivatives with tinacetylene. According to the synthetic routes, we describe here syntheses of beta-anomers of C-Man-Trp, and its glucose and galactose analogues from the corresponding beta-C-glycosylacetylenes. During this study, we have developed a highly stereocontrolled synthesis of beta-C-mannosylacetylene that is required for the synthesis of beta-C-Man-Trp, while the precedented method gave an anomeric mixture of the C-mannosylacetylene. The synthetic C-Man-Trp and its analogues were analyzed by HPLC.

Carbohydrate Conformation↗
PubMed2006

Cyclic AMP-dependent attenuation of oscillatory-activity-induced intercortical strengthening of horizontal pathways between insular and parietal cortices.

Cyclic AMP (cAMP) is a key intracellular second messenger, and the intracellular cAMP signaling pathway acts to modulate various brain functions. We have previously reported that low-frequency insular cortex stimulation in rat brain slices switches on a voltage oscillator in the parietal cortex that delivers signals horizontally back and forth under caffeine application. The oscillatory activities are N-methyl-D-aspartate (NMDA) receptor-dependent, and the role of oscillation is to strengthen functional intercortical connections. The present study investigated actions of the cAMP signaling pathway on caffeine-induced strengthening of intercortical connections and tried to confirm the role of oscillation on intercortical strengthening by focusing on the cAMP pathway. After induction of parietal oscillation by insular cortex stimulation in caffeine-containing medium, application of membrane-permeable cAMP analog, bromo-cAMP, diminished oscillatory signal delivery from the parietal cortex, but initial insulo-parietal signal propagation remained strong. When oscillatory activities were reduced with co-application of caffeine and bromo-cAMP from the beginning, initial insulo-parietal propagation was established, but amplitudes of propagating wavelets and propagating velocity were reduced. Thus, cAMP-dependent diminution of caffeine-induced NMDA-receptor-dependent oscillatory signal delivery causes attenuation of intercortical strengthening of horizontal pathways between insular and parietal cortices. This finding suggests that the intracellular cAMP signaling pathway has the ability to regulate extracellular communications at the network level, and also that full expression of strengthened intercortical signal communication requires sufficient NMDA-receptor-dependent oscillatory neural activities.

2-Amino-5-phosphonovalerate↗
PubMed2005

Inherent potential for production of tumor necrosis factor-alpha by human intestinal macrophages.

BACKGROUND AND AIMS: Tumor necrosis factor (TNF) production by the macrophages in intestines appears to play a critical role in the pathogenesis of Crohn's disease (CD). However, it is reported that resident intestinal macrophages (both colonic and small-bowel) do not produce TNF after lipopolysaccharide (LPS) stimulation. It has not yet been proven whether or not intestinal macrophages have an inherent potential to produce TNF. The purpose of this study is to answer this question. MATERIALS AND METHODS: Colonic macrophages were isolated from lamina propria of human large intestine and stimulated with a variety of substances: LPS, a lipid A derivative (ONO-4007), killed Streptococcus bacterial body (OK-432), phorbol 12-myristate 13-acetate, and lectins (pokeweed mitogen and Sarcophaga lectin). RESULTS: Colonic macrophages were phenotypically negative for CD14 and positive for CD68 and produced very little TNF in response to LPS, as reported previously. Of the substances tested, only Sarcophaga lectin, which is a defense protein of fleshflies (Sarcophaga peregrina), induced TNF production by the intestinal macrophages. In addition, when the colonic macrophages were cultured on immunoglobulin-A-coated dishes, their characteristic response to LPS was altered, and they produced TNF at a level 6.6 times higher than when on collagen-coated dishes. CONCLUSION: Colonic macrophages have an inherent ability to produce TNF. Activation of colonic macrophages by unknown substances may contribute to the induction of TNF production, which causes the intestinal inflammation of CD.

Antigens, CD↗
PubMed2005

NMDA receptor-dependent oscillatory signal outputs from the retrosplenial cortex triggered by a non-NMDA receptor-dependent signal input from the visual cortex.

The retrosplenial cortex is located at a critical juncture between the visual cortex and hippocampal formation. Functions of the retrosplenial cortex at the local circuit level, however, remain unclear. Herein, we show how signals traveling from the visual cortex behave in local circuits of the retrosplenial cortex, using optical recording methods and application of caffeine to rat brain slices. Electrical signals evoked in the primary visual cortex penetrated into the deep layer of the retrosplenial granular a cortex (RSGa) and propagated further toward postsubiculum and upper layer. Non-N-methyl-D-aspartate (NMDA) receptor-dependent initial traveling signal from the visual cortex triggered NMDA receptor-dependent neural oscillation in the RSGa. Oscillatory signals originated from the local area in the deep layer of the RSGa, and the signal spread back and forth toward the visual cortex and postsubiculum, in addition to spreading toward the upper layer. From the perspective of the RSGa, extrinsic signal inputs from the visual cortex switched on neural oscillators in the RSGa that deliver NMDA receptor-dependent intrinsic signal outputs. Opening and strengthening of non-NMDA receptor-dependent input pathways from the visual cortex required NMDA receptor-dependent oscillatory neural activities. These input and output relationships indicate that the retrosplenial cortex may represent an important relay station between the visual cortex and hippocampal formation.

Animals↗
PubMed2005

Strengthening of non-NMDA receptor-dependent horizontal pathways between primary and lateral secondary visual cortices after NMDA receptor-dependent oscillatory neural activities.

Emergence of oscillatory signal flows between the primary visual cortex (Oc1) and medial secondary visual cortex (Oc2M) was previously dynamically demonstrated in rat brain slices by us. Applying caffeine, a neural modulator, to the slices and using optical recording methods revealed this facilitation along horizontal intrinsic pathways in which initial forward propagation from Oc1 to Oc2M was dependent on both N-methyl-D-aspartate receptors (NMDARs) and non-NMDARs. Conversely, oscillatory backward propagation from Oc2M to Oc1 was entirely dependent on NMDARs. The present study examined: (1) whether the signal behavior between Oc1 and lateral secondary visual cortex (Oc2L) is based on the same mechanism with that between Oc1 and Oc2M; and (2) how non-NMDAR and NMDAR activities underlie opening of horizontal corticocortical pathways between Oc1 and Oc2. Under NMDAR blockade, signals elicited in the Oc1 either could not or only weakly penetrated the Oc2L, even in caffeine-containing medium. In contrast, once forward propagation from Oc1 to Oc2L and oscillatory backward propagation from Oc2L to Oc1 was established in caffeine-containing medium, signals elicited in Oc1 could strongly penetrate the Oc2 even during blockade of NMDA activities, when forward penetrating components were dependent on non-NMDARs. These findings suggest that: (1) signal behavior and its mechanism between Oc1and Oc2L are the same with those between Oc1 and Oc2M; and (2) NMDAR activation results in non-NMDAR activity, resulting in opening and strengthening of intrinsic signal pathways between Oc1 and Oc2. NMDAR-dependent forward and backward propagation might be involved in cortical reorganization of the visual cortex.

Animals↗
PubMed2005

Clinical outcomes of extended esophagectomy with three-field lymph node dissection for esophageal squamous cell carcinoma.

OBJECTIVE: Opinions are conflicting about 3-field lymph node dissection (3FLND) during esophagectomy for esophageal cancer. In the current study, we sought to determine the prevalence of cervical and upper thoracic lymph node metastasis in patients with squamous cell carcinoma of the thoracic esophagus and to determine the impact of 3FLND on mortality, morbidity, survival, and recurrence rate. MATERIALS AND METHODS: Among 287 patients with squamous cell carcinoma of the thoracic esophagus seen between November 1985 and December 2001, 141 (49%) underwent extended esophagectomy with 3FLND (cervical, mediastinal, and abdominal lymph node dissection). Patients were observed and clinicopathologic information collected prospectively on all patients until death or August 2002. The median follow-up was 41 months, ranging from 10 to 173 months. RESULTS: Hospital mortality and morbidity rates were 6.4% and 80%, respectively. Thirty-four of 70 node-positive patients had cervicothoracic nodal involvement. Sixteen patients (11%) had nodal involvement confined only to the cervicothoracic nodes, and no patients with lower thoracic esophageal carcinoma showed cervicothoracic involvement alone. The frequency of cervical nodal disease was correlated with nodal status within the mediastinum (P <0.01). The 1-, 3-, and 5-year overall survival rates for all 141 patients were 76%, 58%, and 48%, respectively. Among significant variables verified by univariate analysis, independent prognostic factors for overall survival determined by multivariate analysis were number of lymph node metastasis (P <0.01), amount of blood transfusion (P <0.05), length of operation (P <0.05), and presence of pulmonary complications (P <0.05). CONCLUSIONS: Extended esophagectomy with 3FLND can be performed with an acceptable mortality. Metastases frequently involved the upper thoracic and cervical lesions, and cervical nodal disease was correlated with thoracic nodal status. 3FLND proved to be an important staging system in 11% of patients. An excellent overall survival suggests a superiority of 3FLND when performed at experienced centers.

Aged↗
PubMed2005

Metastatic lymph node size and colorectal cancer prognosis.

BACKGROUND: Colorectal cancer patients with lymph node metastasis constitute a heterogeneous population with variable prognoses. In this study, my colleagues and I propose a simpler lymph node (LN) staging system for colorectal cancer. STUDY DESIGN: Four-hundred and twenty-three consecutive colorectal cancer patients were studied. Of these, 36 were excluded because another carcinoma was present. The remaining 387 patients entered the TNM staging analysis. In the survival analysis, 76 patients with distant metastasis were excluded and the remaining 311 patients (LN(-) = 204 and LN(+) = 107) were studied. The diameter of the largest metastatic LN (MLN) was measured on histopathological slides. After examination of various cutpoints and survival outcomes, patients with MLNs were classified into n1 (< or = 9 mm) and n2 (> or = 10 mm) groups, according to size of MLNs (n-stage). RESULTS: Using disease-free survival (DFS) and overall survival (OS) as outcomes, patients were separated into significant prognostic groups by MLN size (univariate, p < 0.0001) (5-year survival, DFS: n0 = 91.5%, n1 = 62.2%, and n2 = 34.4%; OS: n0 = 85.1%, n1 = 63.5%, and n2 = 42.5%) and International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) (N-stage) (univariate, p < 0.0001) (5-year survival, DFS: N0 = 91.5%, N1 = 60.5%, and N2 = 36.8%; OS: N0 = 85.1%, N1 = 65.3%, and N2 = 38.0%). But in patients with fewer than 15 LNs examined (n = 31), only the new nodal stage stratified patients into significant groups (OS: p = 0.003 and DFS: p = 0.001). Only the UICC/AJCC N-stage subcategories were further split into significant prognostic groups by MLN size (UICC/AJCC N1: DFS, p = 0.048 and OS, p = 0.11; N2: DFS, p = 0.04 and OS, p = 0.04). n-stage was an independent important factor both in the DFS and OS in multivariable analysis. CONCLUSIONS: MLN size is a strong prognostic variable in colorectal carcinoma. This new metric may help clinicians treating colorectal cancer patients, but additional studies are required before clinical application.

Adult↗
PubMed2005

Expression of capsaicin receptor TRPV-1 in synovial tissues of patients with symptomatic internal derangement of the temporomandibular joint and joint pain.

OBJECTIVE: To elucidate expression of capsaicin receptor TRPV-1 in synovial tissues of the human temporomandibular joint (TMJ) with internal derangement and discuss its relationship with joint pain. STUDY DESIGN: Fifty-four TMJs in 54 patients were examined using an immunohistochemical technique. As controls, 10 TMJs with habitual dislocation without pain were also examined. RESULTS: TRPV-1 was expressed mainly in the blood vessels beneath the lining cells in synovial tissues from 31 of the 54 joints with internal derangement and from 8 of the 10 control joints. The extent score of TRPV-1-stained cells with internal derangement was not significantly higher than that of controls. The extent score of TRPV-1 showed no correlation with joint pain. CONCLUSIONS: TRPV-1 was detected in the region of the posterior disk attachment of synovial tissues from the TMJ in patients with internal derangement and controls. TRPV-1 may play a role in maintenance of the physiologic condition of the TMJ.

Adolescent↗
PubMed2004

Prognostic impact of hypoxia-inducible factors 1alpha and 2alpha in colorectal cancer patients: correlation with tumor angiogenesis and cyclooxygenase-2 expression.

PURPOSE: Angiogenesis plays an important role in a multitude of biological processes including those of tumorigenesis and cancer progression. Hypoxia is the prime driving factor for tumor angiogenesis and the family of hypoxia-inducible factors (HIFs) plays a pivotal role in this process. The role of HIF in tumor angiogenesis has been underscored in different carcinomas but yet to be reported for colorectal carcinomas. EXPERIMENTAL DESIGN: In this study, we examined HIF [HIF-1alpha (HIF1) and HIF-2alpha (HIF2)] expression in 87 curatively resected colorectal carcinoma samples, and the results were correlated with clinicopathological factors, microvessel density, cyclooxygenase 2 expression, and patient prognosis. RESULTS: HIF1 (44.8%) was more frequently expressed than HIF2 (29.9%). Most of the clinicopathological factors representing the tumor aggressiveness were significantly correlated with overexpression of HIF2 but not with HIF1 expression. HIF2 expression had direct correlation with microvessel density and cyclooxygenase 2 expression. and, in contrast, HIF1 expression had a weak but significant inverse correlation in T1 and T2 tumors only. HIF2 expression alone and the combined expression of HIF1 and HIF2 had significant impact on patient survival. In the multivariate analysis, however, only the combined expression of HIF1 and HIF2 remained independently significant. CONCLUSIONS: Taken together, our results suggest that HIF2 expression may play an important role in angiogenesis and that the combined expression of HIF1 and HIF2 may play an important role in tumor progression and prognosis of colorectal carcinomas. Therefore, HIF expression could be a useful target for therapeutic intervention.

Adult↗
PubMed2004

Postoperative pulmonary complications are associated with worse short- and long-term outcomes after extended esophagectomy.

BACKGROUND: Risk analysis of pulmonary complications after extended esophagectomy with three-field lymph node dissection (3FLND) has been little reported in the literature. METHODS: Risk factors of developing postoperative pneumonia after extended esophagectomy and its effects on in-hospital death and overall long-term survival were compared between 38 patients who developed pneumonia and 80 patients who did not. RESULTS: Eight patients died of postoperative complications during the hospital stay after esophagectomy. Seven of those 8 patients developed pneumonia, whereas 31 patients of 110 patients who were discharged from the hospital developed pneumonia (P < 0.01). Pneumonia occurred more frequently in elderly patients (P < 0.01), in heavy smokers (P < 0.05), in patients with preoperative pulmonary obstructive dysfunction (P < 0.05), and in patients who received 3 U or more perioperative blood transfusion (P < 0.05). Five-year overall survival rate (26.7%) of 38 patients who developed pneumonia was significantly worse than 53.4% who did not develop pneumonia (P < 0.01). Multivariate analysis of prognostic factors for overall survival showed that pathological tumor stage (hazard ratio 5.380, P < 0.01) and pneumonia (hazard ratio 2.369, P < 0.01) were independent risk factors. Postoperative pneumonia is correlated with in-hospital death and poorer long-term survival after extended esophagectomy with 3FLND. CONCLUSIONS: Elderly patients with a history of heavy smoking and poor pulmonary function should be regarded as a high-risk group of patients for developing pneumonia and very careful selection is required before subjecting such patients to extended esophagectomy.

Aged↗
PubMed2004

Downregulation of KiSS-1 expression is responsible for tumor invasion and worse prognosis in gastric carcinoma.

KiSS-1 is a promising candidate tumor-suppressor gene and may play a key role in the metastatic cascade. The expression profile and the role of KiSS-1 in cancer progression are largely unknown in most of the cancers, including gastric cancer. In this study, KiSS-1 expression was evaluated by RNase protection assay and localization was done by in situ hybridization in 40 gastric cancers and their adjacent normal gastric mucosa. For comparison with clinicopathologic characteristics and patient prognosis, all patients were divided into 2 groups having high and low KiSS-1 expression by using the median as the cutoff value of KiSS-1 expression as determined by the RNase protection assay. Gastric cancers with low KiSS-1 had frequent venous invasion, distant metastasis and tumor recurrence. Accordingly, patients with low KiSS-1-expressing tumors had a significantly worse overall and disease-free survival. In multivariate analysis, KiSS-1 became the strongest independent prognostic factor among the conventional prognosticators for gastric cancer patients. Collectively, these findings suggest that KiSS-1 may play a crucial role in gastric cancer invasion and could be a useful target for therapeutic intervention.

Adenocarcinoma↗
PubMed2004

To-and-fro optical voltage signal propagation between the insular gustatory and parietal oral somatosensory areas in rat cortex slices.

Taste perception depends not only on special taste information processed in the insular cortex, but also on oral somesthetic processing in the parietal cortex. Many insular cortex neurons show multimodal responsiveness. Such multimodality may be enabled by signal exchange between these two cortices. By using the protocol that we have developed, a synchronized population oscillation of synaptic potentials was induced in the parietal cortex by stimulation to the insular cortex in rat neocortex slices. The spatiotemporal pattern of propagation of this oscillation was studied by recording voltage-sensitive optical signals and field potentials. The first wavelet of the oscillation was propagated from the insular stimulation site to the parietal cortex. However, the second and later wavelets propagated back from the parietal cortex to the insular cortex. The oscillation was detected in the insular cortex as well, but was actually generated in the parietal cortex. Thus, the initial peak of optical signal, sent from the insular to parietal cortex, served to generate oscillatory responses in the parietal cortex, which propagated back to the insular cortex wave-by-wave. We propose that this to-and-fro propagation may be an artificially exaggerated demonstration of an intrinsic mechanism relevant to signal exchange between the parietal and insular cortices.

Animals↗