Biomedical subjects

Ken-ichi Watanabe

Publications and source records attributed to Ken-ichi Watanabe.

At least 19 recordsLinked to original sources

PubMed2006

Control of cell polarity and motility by the PtdIns(3,4,5)P3 phosphatase SHIP1.

Proper neutrophil migration into inflammatory sites ensures host defense without tissue damage. Phosphoinositide 3-kinase (PI(3)K) and its lipid product phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P(3)) regulate cell migration, but the role of PtdIns(3,4,5)P(3)-degrading enzymes in this process is poorly understood. Here, we show that Src homology 2 (SH2) domain-containing inositol-5-phosphatase 1 (SHIP1), a PtdIns(3,4,5)P(3) phosphatase, is a key regulator of neutrophil migration. Genetic inactivation of SHIP1 led to severe defects in neutrophil polarization and motility. In contrast, loss of the PtdIns(3,4,5)P(3) phosphatase PTEN had no impact on neutrophil chemotaxis. To study PtdIns(3,4,5)P(3) metabolism in living primary cells, we generated a novel transgenic mouse (AktPH-GFP Tg) expressing a bioprobe for PtdIns(3,4,5)P(3.) Time-lapse footage showed rapid, localized binding of AktPH-GFP to the leading edge membrane of chemotaxing ship1(+/+)AktPH-GFP Tg neutrophils, but only diffuse localization in ship1(-/-)AktPH-GFP Tg neutrophils. By directing where PtdIns(3,4,5)P(3) accumulates, SHIP1 governs the formation of the leading edge and polarization required for chemotaxis.

Animals↗

PubMed2006

Swimming stress in DN 14-3-3 mice triggers maladaptive cardiac remodeling: role of p38 MAPK.

It is generally believed that a mechanical signal initiates a cascade of biological events leading to coordinated cardiac remodeling. 14-3-3 family members are dimeric phosphoserine-binding proteins that regulate signal transduction, apoptotic, and checkpoint control pathways. To evaluate the molecular mechanism underlying swimming stress-induced cardiac remodeling, we examined the role of 14-3-3 protein and MAPK pathway by pharmacological and genetic means using transgenic mice with cardiac-specific expression of dominant-negative (DN) mutants of 14-3-3 (DN 14-3-3/TG) and p38alpha/beta MAPK (DNp38alpha and DNp38beta) mice. p38 MAPK activation was earlier, more marked, and longer in the myocardium of the TG group compared with that of the nontransgenic (NTG) group after swimming stress, whereas JNK activation was detected on day 5 and decreased afterward. In contrast, ERK1/2 was not activated after swimming stress in either group. Cardiomyocyte apoptosis, cardiac hypertrophy, and fibrosis were greatly increased in the TG group compared with those in the NTG group. Moreover, we found a significant correlation between p38 MAPK activation and apoptosis in the TG group. Furthermore, DN 14-3-3 hearts showed enhanced atrial natriuretic peptide expression. In contrast, DNp38alpha and DNp38beta mice exhibited reduced mortality and increased resistance to cardiac remodeling after 28 days of swimming stress compared with TG and NTG mice. Besides, treatment with a p38 MAPK inhibitor, FR-167653, resulted in regression of cardiac hypertrophy and fibrosis and improvement in the survival rate in the TG group. These results indicate for the first time that 14-3-3 protein along with p38 MAPK plays a crucial role in left ventricular remodeling associated with swimming stress.

14-3-3 Proteins↗

PubMed2006

DOCK2 is a Rac activator that regulates motility and polarity during neutrophil chemotaxis.

Neutrophils are highly motile leukocytes, and they play important roles in the innate immune response to invading pathogens. Neutrophil chemotaxis requires Rac activation, yet the Rac activators functioning downstream of chemoattractant receptors remain to be determined. We show that DOCK2, which is a mammalian homologue of Caenorhabditis elegans CED-5 and Drosophila melanogaster Myoblast City, regulates motility and polarity during neutrophil chemotaxis. Although DOCK2-deficient neutrophils moved toward the chemoattractant source, they exhibited abnormal migratory behavior with a marked reduction in translocation speed. In DOCK2-deficient neutrophils, chemoattractant-induced activation of both Rac1 and Rac2 were severely impaired, resulting in the loss of polarized accumulation of F-actin and phosphatidylinositol 3,4,5-triphosphate (PIP3) at the leading edge. On the other hand, we found that DOCK2 associates with PIP3 and translocates to the leading edge of chemotaxing neutrophils in a phosphatidylinositol 3-kinase (PI3K)-dependent manner. These results indicate that during neutrophil chemotaxis DOCK2 regulates leading edge formation through PIP3-dependent membrane translocation and Rac activation.

Actins↗

PubMed2006

[F-18]Fluorodeoxyglucose positron emission tomography can predict pathological tumor stage and proliferative activity determined by Ki-67 in clinical stage IA lung adenocarcinomas.

OBJECTIVE: To predict a malignant grade of lung cancer by fluorodeoxyglucose positron emission tomography (FDG-PET) scanning, we investigated the correlation between FDG uptake and pathological tumor stage, proliferative activities determined by Ki-67 and cyclin D1, and an alteration of p53, in clinical stage (c-stage) IA lung adenocarcinomas. METHODS: FDG-PET was performed for 71 patients with c-stage IA lung adenocarcinomas. FDG uptake was measured by a contrast ratio (CR) between the tumor and contralateral lung. Ki-67, cyclin D1 and p53 staining scores were examined by immunohistochemistry. RESULTS: The lesions with ground-glass opacity were found in 26 patients, and solid lesions in 45 by computed tomography. The pathological tumor stages (p-stage) were stage IA in 59 and more advanced stages in 12. The latter had significantly higher CR value than the former (P < 0.001). Patients with CR > or = 0.55 could be predicted to be at advanced tumor stages, with a sensitivity of 0.83 and a specificity of 0.82. The CR and staining scores of Ki-67 were significantly correlated with each other (P < 0.0001), and both the values were significantly higher in advanced tumor stages than in p-stage IA, and were also significantly higher in tumors with intratumoral lymphatic, vascular and pleural involvements than in those without such features (P < 0.05-0.0001). CONCLUSIONS: In c-stage IA lung adenocarcinomas, the FDG uptake can predict p-stage and tumor proliferative activity determined by Ki-67. For c-stage IA lung adenocarcinomas showing CR > or = 0.55, mediastinoscopy or neoadjuvant chemotherapy is indicated.

Adenocarcinoma↗

PubMed2006

Usefulness and complications of computed tomography-guided lipiodol marking for fluoroscopy-assisted thoracoscopic resection of small pulmonary nodules: experience with 174 nodules.

OBJECTIVE: Several techniques have been reported for the localization of small pulmonary nodules in thoracoscopic resection. In the present study we examined the usefulness and complications of computed tomography-guided lipiodol marking for thoracoscopic resection in our experience of 174 nodules. METHODS: Computed tomography-guided lipiodol marking was performed on 174 nodules less than 30 mm in size. Of these nodules, 45 showed ground-glass opacity images and 129 showed solid images on computed tomography. The mean size of the nodules was 10 +/- 6 mm (range, 2-30 mm), and their mean depth from the pleural surface was 10 +/- 7 mm (range, 0-30 mm). One to 7 days before thoracoscopy, all of the nodules were marked with 0.4 to 0.5 mL of lipiodol by using computed tomography. The marked nodules were grasped with a ring-shaped forceps during fluoroscopy and resected by means of thoracoscopy. RESULTS: All the nodules could be marked and localized by means of fluoroscopy as a clear spot during thoracoscopic surgery. Complications of the marking were chest pain requiring analgesia in 16 (11%) patients, hemosputum in 11 (6%) patients, pneumothorax in 30 (17%) patients, and hemopneumothorax in 1 (0.6%) patient. Eleven (6%) patients with pneumothorax required drainage, and the patient with hemopneumothorax required an emergency operation. No other complications were observed. CONCLUSION: Lipiodol marking is a useful, safe, and inexpensive procedure for localizing ground-glass opacity lesions, small pulmonary nodules, or both for thoracoscopic resection.

Adult↗

PubMed2006

FDG-PET imaging for lymph node staging and pathologic tumor response after neoadjuvant treatment of non-small cell lung cancer.

PURPOSE: A number of studies have demonstrated that 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is effective for staging of lung cancer. However, the efficacy of FDG-PET for staging lung cancer after neoadjuvant treatment is still controversial. This study compared FDG-PET and computed tomography (CT) for lung cancer staging, and evaluated the ability of the two methods to predict the pathologic response of the primary tumor to neoadjuvant treatment. PATIENTS AND METHODS: Twenty-two patients who underwent neoadjuvant treatment followed by surgery were investigated. Eighteen patients received chemoradiotherapy and four patients received chemotherapy only. One hundred and three lymph node stations in the 22 patients were evaluated by FDG-PET and CT. The pathologic responses of the tumors were compared by FDG-uptake and tumor size on CT for the 15 patients who underwent FDG-PET and CT both before and after neoadjuvant treatment. RESULTS: There was no significant difference in the ability of FDG-PET or CT to predict residual viable tumor. Although positive predictive value by FDG-PET (0.29) was lower than that by CT (0.64) (p=0.04) in the mediastinal lymph nodes, there were no statistically significant differences in the other results of lymph nodes by FDG-PET and CT. Both decrease in FDG-uptake and decrease in tumor size by CT after neoadjuvant treatment correlated significantly with pathologic response in the 15 patients (p=0.003 and 0.009, respectively). CONCLUSION: FDG-PET did not appear to offer any advantages over CT for lymph node staging or for predicting the pathologic response after neoadjuvant treatment of non-small cell lung cancer.

Adult↗

PubMed2006

[Efficacy and toxicity of combination treatment with epirubicin (EPI) plus docetaxel (DOC) in advanced breast cancer].

Thirty women (mean age 50.4 years, range 31-63) with primary advanced breast cancer were given EPI 40-60 mg/m(2) and DOC 50-60 mg/m(2) intravenously every three weeks. The efficacy was evaluated after 4 cycle treatments. There were 5 complete responses (CR) and 14 partial responses (PR), giving an overall response rate of 63.3%. There were 2 pathological CR (8%) which showed complete disappearance of cancer cells. The high dose group showed a better response than the low-dose group. The most common grade 3/4 adverse events were neutropenia (26.7%) and general fatigue (6.7%). The simultaneous combination treatment of EPI and DOC is effective for primary chemotherapy and can be performed safely even for outpatients.

Adult↗

PubMed2005

pH of solution greatly affects sorption of ionizable compounds into low-density polyethylene film.

Sorption of ionizable compounds of pyridines and aromatic carboxylic acids into low-density polyethylene (LDPE) film was investigated as a function of pH ranging from 4 to 7. The sorptions for pyridines were increased with increasing pH. Within the range examined, pH 7 was observed to promote the highest degree of sorption. When the pH increased by one unit from 6 to 7, the sorptions for 2-propylpyridine and 2,4,6-trimethylpyridine were both increased approximately 3.8 and 10.5 times, respectively. At pH 4, the sorption for the pyridines entirely disappeared. In contrast, the sorptions for aromatic carboxylic acids increased with decreasing pH. Within the range examined, pH 4 was observed to promote the highest degree of sorption. The magnitude of sorption for pyridines and carboxylic acids apparently depended on the affinity (delta(c)) of these compounds for LDPE film. Another factor affecting the sorption at various pHs was the pK(a) of these compounds; the sorption greatly decreased with the ionization degree of these compounds. To elucidate the phenomena, the following thermodynamic sorption equation was applied: S = S(0)gamma exp[V(v){(delta(w) - delta(v))(2) - delta(c)(2))/RT}. The plots of ln S for pyridines vs the term of the equation gave an insufficient relationship (r = 0.519). In contrast, taking into account the ratio (chi(i)()) of concentration of un-ionized compound to total concentration, the improvement for the equation was made: S' = S/chi(i)() = S(0)gamma exp[V(v){(delta(w) - delta(v))(2) - delta(c)(2))/RT}. The plots of ln S' vs the term of the equation gave a better relationship (r = 0.884). Furthermore, the equation was also applicable for the sorption behavior of carboxylic acids into LDPE (r = 0.769).

Adsorption↗

PubMed2005

Effect of Helicobacter pylori eradication in patients with chronic idiopathic thrombocytopenic purpura-a randomized controlled trial.

OBJECTIVE: Eradication of Helicobacter pylori was reported to increase the platelet counts in some H. pylori-positive patients with chronic idiopathic thrombocytopenic purpura (cITP). However, the efficacy of the eradication was quite different according to the previous reports. To determine whether H. pylori infection can contribute to cITP, we performed a randomized controlled trial for the first time. In addition, to investigate the possible pathogenic mechanisms and to predict the platelet response after eradication of H. pylori in each cITP patient, several H. pylori virulence factors, the urease activities of the infected H. pylori strains, and the titers of anti-CagA IgG antibodies were analyzed. METHODS: Patients with cITP underwent gastroscopy and gastric H. pylori infection was confirmed by culture. H. pylori-positive cITP patients were randomly assigned to either the eradication or the non-eradication group. The eradication group received a standard antibiotic therapy for H. pylori. Response to treatment was defined as complete (CR) if the platelet count was above 150x10(3)/microl and partial (PR) if the platelet count increased by more than 50x10(3)/microl above the pretreatment count. The virulence factors were investigated by PCR and PCR-based direct sequencing. Anti-CagA IgG antibody titer of each patient's serum was measured by ELISA. RESULTS: Of the 36 ITP patients, 25 (69.4%) were positive for H. pylori and eradication was achieved in 84.6% of these patients. The platelet response was significantly different between the eradication group (46.2%) and the non-eradication group (0%). No significant differences were found in clinical factors between the responders and the nonresponders. H. pylori virulence factors and the urease activity were not associated with the response. The titers of anti-CagA antibodies in the responders were significantly higher than those in the nonresponders (p=0.04). CONCLUSIONS: H. pylori eradication treatment is a favorable therapeutic option for H. pylori-positive patients with cITP. Moreover, an ELISA titer of serum anti-CagA antibody may be a good predictor of platelet recovery, and immunological reaction between platelet and anti-CagA antibodies may have some relation to the pathogenesis of H. pylori-positive patients with cITP.

Anti-Bacterial Agents↗

PubMed2004

Acoustic stimulation promotes the expression of inducible nitric oxide synthase in the vestibule of guinea pigs.

Loud acoustic stimulation is known to cause inner ear disturbance. We examined immunohistochemically the vestibule of 12 guinea pigs after acoustic stimulation. The animals were divided into two equal groups: a control group and an acoustic stimulation group. The temporal bones were fixed by means of a cardiac infusion of fixative and immunohistochemically stained for inducible nitric oxide synthase (iNOS). The temporal bones in the control group did not show any iNOS. In the acoustic stimulation group, immunoreactivity for iNOS was detected in the supporting cells and sensory cells of the sensory epithelium, in the dark cell areas and in the vestibular ganglion cells. These findings suggest that free radicals are involved in the pathogenesis of noise-induced inner ear damage. Furthermore, free radicals may cause vestibular damage, as is seen in noise-induced inner ear damage.

Acoustic Stimulation↗

PubMed2004

Efficacy and tolerability of cancer pain management with controlled-release oxycodone tablets in opioid-naive cancer pain patients, starting with 5 mg tablets.

BACKGROUND: We conducted an open-label, dose titration study to assess the efficacy and tolerability of controlled-release oxycodone in the therapy of cancer pain management, starting with a newly developed 5 mg tablet every 12 h. METHODS: Twenty-two Japanese cancer patients with pain who had not been taking opioid analgesics over the previous 2 weeks were enrolled. The length of time and the dose needed to attain stable and adequate pain control were evaluated in addition to the assessment of analgesic efficacy and safety during the study period. RESULTS: Eighteen patients in the efficacy population (18 out of 20, 90%) attained stable, adequate pain control. Two-thirds of the patients attained stable, adequate pain control without any dose titration. The mean length of time was 1.2 days. In these patients, the pain was significantly reduced in intensity, even at 1 h after the initial dose intake. Fifteen patients (68%) reported at least one side effect, but only one patient had to withdraw from the study because of a side effect. CONCLUSION: The results suggest that controlled-release oxycodone tablets offered stable and adequate pain control within a short period of time in most Japanese cancer patients who have not been taking opioid analgesics, and could be effectively titrated against pain from a starting dose of 5 mg every 12 h. This indicates that a lower strength controlled-release oxycodone formulation may make it possible to start and titrate the dose more appropriately and carefully in patients who are sensitive to opioid analgesics.

Aged↗

PubMed2004

Subcutaneous emphysema after tonsillectomy: a case report.

We experienced a case of a subcutaneous emphysema after tonsillectomy. The patient, a 24-year-old man, complained of a recurrent sore throat and was diagnosed as having chronic tonsillitis. Pre-operative general examinations revealed no abnormalities. The operation was carried out under general anesthesia. The adhesions between the tonsils and the surrounding tissues were moderate. The bi-lateral tonsils were easily removed. The recovery period was uneventful. On the next morning, marked swelling of the left cheek and submandibular area was noted. On palpation, there was a characteristic crepitation and softness in these areas. The X-ray examination revealed subcutaneous emphysema. There was no finding of airway obstruction. We diagnosed him as having a subcutaneous emphysema and administered antibiotics for 5 days. From clinical findings, the subcutaneous emphysema was thought to be caused by surgical rather than anesthetic factors. The subcutaneous emphysema gradually disappeared. One year after the tonsillectomy, the patient is under observation as an outpatient and is free from any abnormal symptoms. To avoid this kind of complication, we should pay attention to carefully separate the tonsil from its fossa and to make appropriate selection of surgical equipments.

Adult↗

PubMed2004

[In vitro chemosensitivity test for hepatocellular carcinoma using collagen-gel droplet embedded cultures].

This study evaluated an in vitro assay for chemosensitivity test using a collagen-gel droplet-embedded culture drug sensitivity test (CD-DST) for hepatocellular carcinoma (HCC). In 25 patients with HCC, in vitro chemosensitivity to 5-fluorouracil (5-FU), epirubicin (EPI), and cisplatin (CDDP) was examined by CD-DST, and 5-FU, EPI, and paclitaxel (PTX) were examined in 38 patients with breast cancer. Successful rates of chemosensitive evaluation by CD-DST were 64% for HCC and 79% for breast cancers. Although chemosensitivities of breast cancer were 5-FU 23.1%, EPI 83.3%, and PTX 67.7%, only one HCC sample was sensitive to EPI. Growth rates of HCC for 7 days of culture were significantly lower than those of breast cancers (1.04 vs 3.61). The culture methods for HCC in CD-DST should be improved to estimate accurate results.

Antineoplastic Agents↗

PubMed2003

A novel HECT-type E3 ubiquitin ligase, NEDL2, stabilizes p73 and enhances its transcriptional activity.

Expression of p73, a p53 family member regulating cell growth and apoptosis, is maintained at low levels in mammalian cells, and cellular activation of p73 is usually controlled at the protein level. However, the precise molecular mechanisms by which p73 stability is regulated are unclear. During the search for interacting molecules with the COOH-terminal proline-rich region of p73, we identified a novel NEDD4-related protein (termed as NEDL2) which contains a C2 domain at its NH(2)-terminus, two WW domains, and a HECT domain at its COOH-terminus. As expected, NEDL2 catalyzed the ubiquitination of bacterial cellular proteins in vitro. Reciprocal co-immunoprecipitation experiments and in vitro pull-down assays revealed that NEDL2 bound to p73, which carries two putative PY motifs. p73 was efficiently ubiquitinated but stabilized in a NEDL2-dependent manner. Accordingly, p73 decayed at faster rates in the absence of NEDL2 than in its presence. Consistent with the NEDL2-mediated stabilization of p73, NEDL2 enhanced the p73-dependent transcriptional activation. Thus, our results suggest that NEDL2 activates the function of p73 by increasing its stability.

Amino Acid Sequence↗

PubMed2003

Negative autoregulation of p73 and p53 by DeltaNp73 in regulating differentiation and survival of human neuroblastoma cells.

p73, mapped to 1p36.2-3, is a p53-related tumor suppressor but is also induced by the oncogene products such as E2F1, raising a question whether p73 is a tumor suppressor gene or oncogene. p73 has several splicing variants including DeltaNp73 which lacks the NH(2)-terminal transactivation domain. In developing neurons, DeltaNp73 is expressed abundantly and seems to inhibit the pro-apoptotic function of p53. However, the role of TAp73 and DeltaNp73 as well as their regulatory mechanism in cell growth and differentiation of neuroblastoma cells are poorly understood. We have found that TAp73 directly activates the transcription of endogenous DeltaNp73 by binding to the TAp73-specific target element located at position-76 to 57 within the DeltaNp73 promoter region. DeltaNp73 was physically associated with TAp73alpha, TAp73beta and p53, and inhibited their transactivation activities when used reporters of Mdm2, Bax or DeltaNp73 itself in SAOS-2 cells. Overexpression of DeltaNp73 in SH-SY5Y neuroblastoma cells promoted cell survival by competing with p53 and TAp73 itself. Thus, our results suggest that the negative feedback regulation of TAp73 by its target DeltaNp73 is a novel autoregulatory system for modulating cell survival and death, that is also functioning in neuroblastoma cells.

Cell Differentiation↗

PubMed2003

Function of p73, not of p53, is inhibited by the physical interaction with RACK1 and its inhibitory effect is counteracted by pRB.

The newly identified p53-related gene, p73, encodes a nuclear transcription factor. Unlike p53, p73 has various isoforms with different NH(2)- and COOH-terminal tails. p73alpha with the longest COOH-terminal extension is most abundantly expressed in many tissues and cells among those splicing isoforms of p73 and the COOH-terminal region appears to have an autoregulatory function. To isolate and characterize the cellular protein(s) that interacts with the unique COOH-terminal region of p73alpha, we employed a yeast two-hybrid screen with a human fetal brain and 293 cell cDNA libraries. We identified the receptor for activated C kinase (RACK1) as a new member of p73alpha-binding proteins. The interaction was confirmed by coimmunoprecipitation experiments, whereas RACK1 did not interact with p53 or p73beta. Ectopic overexpression of RACK1 in SAOS-2 cells reduced the p73alpha-mediated transcription from the p53/p73-responsive promoters, and inhibited the p73alpha-dependent apoptosis. On the other hand, the p53-dependent transcriptional activation as well as apoptosis was unaffected in the presence of RACK1. Furthermore, we found that pRB physically bound to RACK1, and repressed the RACK1-dependent inhibition of p73alpha. Taken together, our observations suggest that pRB diminishes the RACK1-mediated inhibition of p73alpha activity through the interaction with RACK1.

Animals↗

PubMed2003

Expression of caspase-activated deoxyribonuclease (CAD) and caspase 3 (CPP32) in the cochlea of cisplatin (CDDP)-treated guinea pigs.

Cisplatin, an anti-cancer drug, is known to induce apoptosis. During apoptosis, double-stranded DNA is broken into single-stranded DNA by the action of caspases and caspase activated deoxyribonuclease (CAD). We immunohistochemically examined the cochlea of guinea pigs for signs of the apoptosis after the administration of cisplatin. Cisplatin (10 mg/kg b.w.) was intraperitoneally injected to guinea pigs and 3 days later, the animals were sacrificed by intracardiac perfusion of 4% paraformaldehyde. The temporal bones were then removed and immunohistochemically stained for CAD and caspase 3, using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labelling method. CAD was observed in the stria vascularis and the spiral ligament. Caspase 3 was also detected in the stria vascularis, the spiral ligament and the supporting cells of the organ of Corti. These findings suggest that apoptosis is involved in the cochlear damage observed in cancer patients treated with cisplatin.

Animals↗

PubMed2003

Foreign body in the maxillary sinus--possible plastic tube: a case report.

We experienced the case of a patient who had a foreign body in the maxillary sinus. The patient complained of recurrent unilateral badly smelling rhinorrhea. The computed tomography and the magnetic resonance images revealed a foreign body in the maxillary sinus. The foreign body was removed via the Caldwell-Luc approach. The foreign body was a plastic tube, which was supposed to be designed for the drainage of the maxillary sinus. However, the patient did not remember having been subjected to a treatment using such kind of tube. After the surgical removal, the patient became free from the nasal symptoms.

Adult↗