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Biomedical subjects

Y Yamazaki

Publications and source records attributed to Y Yamazaki.

At least 163 records · Page 9Linked to original sources
PubMed2000

Role of the beta(3)-adrenoceptor in urine storage in the rat: comparison between the selective beta(3)-adrenoceptor agonist, CL316, 243, and various smooth muscle relaxants.

The objective of this study was to compare the effects of a beta(3)-adrenoceptor (beta(3)-AR) agonist on bladder function and cardiovascular parameters in rats with those of several drugs that act on smooth muscle. CL316,243 (beta(3)-AR agonist), isoproterenol (nonselective beta-AR agonist), procaterol (beta(2)-AR agonist), verapamil (Ca(2+) antagonist), and papaverine (antispastic drug) each evoked a concentration-dependent relaxation of the detrusor in vitro. They also reduced bladder pressure in anesthetized rats, the beta-AR agonists apparently being more potent than the other drugs. Atropine (muscarinic antagonist) neither relaxed detrusor strips nor reduced bladder pressure. In anesthetized rats, CL316,243 and atropine each had only a slight influence on blood pressure and heart rate, but isoproterenol, procaterol, verapamil, and papaverine significantly affected cardiovascular function at the same dose range as that required to reduce bladder pressure. In cystometry experiments, CL316,243 (10 microg/kg i.v.), verapamil (1 mg/kg i.v.), and papaverine (1 mg/kg i.v.) all significantly prolonged micturition interval and increased bladder capacity, but did not change the residual urine volume after a micturition contraction. Procaterol (100 microg/kg i.v.) prolonged the micturition interval and increased both bladder capacity and residual urine volume (all significantly). Atropine (100 microg/kg i.v.) reduced micturition pressure and increased residual urine volume (both significantly). Because the human detrusor, like the rat detrusor, relaxes on beta(3)-AR stimulation, we conclude that this beta(3)-AR agonist may have potential in pollakiuria (frequent urination) as a therapeutic agent without cardiovascular side effects.

Adrenergic beta-Agonists↗
PubMed2000

[A case of pulmonary tuberculosis complicated with multiple bone and joint tuberculosis].

A 29-year-old male complaining of fever and general fatigue was admitted to our hospital. On admission chest X-ray showed infiltrative shadows with cavities in the bilateral lung apical areas, and sputum examination for acid fast bacilli was smear positive, Gaffky 1. He was treated as pulmonary tuberculosis (TB), and chest X-ray findings and sputum examination improved after a few months of treatment with antituberculous chemotherapy (INH, RFP, EB, PZA). However, tuberculous cold abscess appeared in retropharyngeal area, subcutaneous tissue of thoracic cage and retroperitoneal space, and shortly later, bone and joint TB were recognized in shoulder and wrist joints and vertebrae. The findings of vertebral foci were not recognized by a simple X-ray picture of vertebrae. at that time, but MRI of vertebrae showed low intensity areas with ring enhancement in the cervical, thoracic and lumbar vertebrae. Despite treatment with antituberculous agents, new bone and joint TB had developed in many tissues and had accompanied with cold abscess in adjacent tissue, whereas pulmonary TB had improved after the initial transient worsening. The appearance of bone and joint TB was most probably caused by the initial transient worsening of hidden bone and joint TB as a part of the initial systemic transient worsening of tuberculosis. After treatment for 4 months, pulmonary TB as well as bone and joints TB had improved. Tuberculous cold abscess in retropharyngeal may be secondary to cervical vertebral TB but is now rarely seen. In this case, involvement in many tissues such as retropharyngeal area, subcutaneous tissue of thoracic cage and retroperitoneal space were seen, and these findings are now uncommon and usually represents involvement secondary to contiguous infection.

Adult↗
PubMed2000

[Clinical evaluation of granisetron hydrochloride for nausea and vomiting induced by oral anticancer drugs].

We investigated the antiemetic effect, safety and usefulness of granisetron hydrochloride tablets on nausea and vomiting induced by oral anticancer drugs used in chemotherapy for gastric cancer and colorectal cancer. In the present trial, oral administration of granisetron hydrochloride was performed during 5 days after nausea or vomiting. 1) Clinically, the effective rate of granisetron hydrochloride (the percentage of cases in which the drug was assessed as "Remarkably effective" or "Effective") was more than 75% on each day of administration. There were no adverse events or abnormal laboratory tests. 2) In terms of usefulness, granisetron hydrochloride was rated "Extremely useful" or "Useful" in 17 out of 23 cases (78.2%). The above results have shown that granisetron hydrochloride tablets, administrated orally once daily at a dose of 2 mg, have an excellent antiemetic effect, and that this is a safe and useful drug.

Administration, Oral↗
PubMed2000

[Study on the progression of visual field defect and clinical factors in normal-tension glaucoma].

PURPOSE: We investigated the relationship between the progression of visual field defect and clinical factors in patients with normal-tension glaucoma (NTG). SUBJECTS AND METHODS: Forty-eight eyes of 48 NTG patients undergoing more than 5-year follow-up were enrolled in this study. Their visual field defects ranged between Aulhorn's classification stage 2 and 4, and mean deviation (MD) more than -10 dB measured by Humphrey Field Analyzer (HFA). End points of this follow-up study were defined as follows: in HFA STATPAC 2 glaucoma change probability analysis, more than 5 points which significantly deteriorated at p < 0.05 were found at 2 consecutive examinations (Criterion 1) or a significant decrease in MD value at p < 0.025 was encountered at one examination or in MD value at p < 0.05 at consecutive examinations (Criterion 2). RESULTS: During the follow-up period, 18 eyes of 48 patients satisfied Criterion 1 and 21 eyes Criterion 2. There were no significant differences in clinical factors between patients with progression and without progression. By multiple logistic regression analysis, minimum flow velocity of central retinal artery (CRA) showed significant relation (odds ratio for a 1 cm/sec rise = 0.2215; 95% confidence interval: 0.0530-0.9253) to progression of visual field defect in Criterion 1, and minimum flow velocity of CRA (odds ratio for a 1 cm/sec rise = 0.2099; 95% confidence interval: 0.0506-0.8712) and cholesterol (odds ratio for a 1 cm/dl rise = 1.0332; 95% confidence interval: 0.4096-2.6064) showed significant relation in Criterion 2. CONCLUSION: These results suggests that vascular risk factors of ocular blood flow may play a role in the progression of visual field defects in NTG patients.

Adult↗
PubMed2000

[The clinical application of a new method for sealing the cut surface of lung using the photopolymerized synthetic bioabsorbable hydrogel (Advaseal)].

We report a case of 67-years-old male, who suffered right upper lobectomy for primary lung cancer. The upper-middle interlobar surface of right lung was incomplete interlobe. Many air leakages were noted in the cut surface of upper-middle interlobe during the sealing test. We sealed this cut surface of upper-middle interlobe by using the photopolymerized synthetic bioabsorbable hydrogel (Advaseal). Air leakage was not noted during the sealing test, and no leakage was not noted after operation. We have observed no biological toxicity (such as cytotoxicity, hemolytic toxicity, systemic toxicity or mutagenic toxicity) by using Advaseal. The new photopolymerized synthetic bioabsorbable hydrogel (Advaseal) is a effective sealant against pulmonary air leaks in the cut surface of the lung.

Aged↗
PubMed2000

[Diagnosis of breast cancer extent using dynamic multidetector-row CT: correlation between MPR imaging and pathological cross-sections].

PURPOSE: To evaluate the clinical usefulness of dynamic multidetector-row CT (dynamic MD-CT) for the detection of intraductal extension of breast cancer. MATERIALS AND METHODS: Dynamic MD-CT was performed in 31 patients with breast masses (26 invasive ductal carcinomas, 4 non-invasive ductal carcinomas and one benign lesion). We grouped the cases into four categories according to the degree of intraductal extension of the main tumor: IDS1: intraductal component less than 1 cm, IDS2: intraductal component 1 cm to 2 cm, IDS3: intraductal component 2 cm to 3 cm, IDS4: intraductal component more than 3 cm. To achieve complete CT-pathologic correlation, we retrospectively reconstructed MPR in the same plane as the histological cross-section. RESULTS: Thirty breast carcinomas (100%) showed strong enhancement in both the first and second phases of contrast enhanced dynamic MD-CT. The sensitivity and specificity of dynamic MD-CT for the detection of the intraductal component were 80.0% (12/15) and 100% (15/15). The accuracy of detection for the four tumor categories was 100% (15/15) for IDS1, 25% (1/4) for IDS2, 42.9% (3/7) for IDS3, and 100% (4/4) for IDS4. CONCLUSION: Dynamic MD-CT of the breast was found to be effective for the detection of intraductal extension of breast carcinoma and thought to be useful in the preoperative assessment of indications of breast-conserving surgery.

Adult↗
PubMed2000

[Three cases of Mycobacterium avium lung disease in an iron foundry].

We report three cases of M. avium lung disease, all occurring in the same iron foundry over a 5-year period. Case 1: A 38-year-old man was admitted to our hospital because of abnormal chest x-ray shadows observed during a routine checkup. M. avium complex was isolated from the sputum and a CT scan showed multiple nodular shadows with cavities. Case 2: A 63-year-old man presented with dyspnea. Chest CT showed nodular shadows in both upper lobes. M. avium complex was isolated from his sputum. Case 3: A 62-year-old man was hospitalized for treatment of diabetes mellitus. A nodular cavitary shadow* OK?* in the right upper lobe was observed in the radiograph. CT scanning demonstrated a nodular shadow with thick pleural indentation. M. avium was isolated from the sputum and gastric juices. There were similarities in the radiographic findings in all cases: nodular shadows with cavities in the upper lung fields. These findings differed from those in another M. avium infection in the lung which occurred in a middle-aged woman. We suspected inhalation of an aerosol contaminated by M. avium complex. There have hitherto been no reports of group infections in healthy persons. We suspected the same environmental source for the infection.

Adult↗
PubMed2000

[Results of surgery in Mycobacterium avium complex pulmonary disease].

Recently, several studies have revealed the usefulness of surgical therapy for nontuberculous mycobacterial (NTM) disease. We have encountered and taken many opportunities for surgical therapy in Mycobacterium avium complex (MAC) disease. From April 1995 through March 1999, 14 patients with MAC disease underwent 16 pulmonary resections. NTM was diagnosed at our hospital in all subjects according to the criteria of the American Thoracic Society. There were 8 women and 6 men, with a mean age of 54 years. The most common indications for surgery were localized lesion (7 cases), severe symptoms (5 cases) and progressive disease (2 cases). Twelve patients were receiving multidrug chemotherapy, 10 of whom were also receiving clarithromycin. The mean period of preoperative chemotherapy was 17 months. Ten patients had a variety of symptoms, with some combination of cough, sputum, hemosputum, dyspnea, fever and anorexia. About 30% of the symptoms were improved after preoperative chemotherapy. The symptoms disappeared in all except one patient, who underwent pneumonectomy. After surgery, all patients attained a sputum-negative status. Nine patients underwent 11 partial resections, comprising 3 thoracotomies and 8 video-assisted thoracic surgeries (VATS). There was no operative mortality. Re-operation was performed in a patient with bronchopleural fistula after initial surgery. Currently, 2 months after the last operation, we have encountered no other severe complication and no relapse. Surgery may play an important role in treatment of MAC disease. We recommend partial resection with VATS for localized MAC disease.

Adult↗
PubMed2000

[A case of malignant lymphoma showing a stratum of lymphoma cells].

A 74-year man suffered an artificial pneumothorax of the right lung because of pulmonary tuberculosis 41 years before. He was admitted, and enlargement of chronic pyothorax was noted in chest radiography in 1998. A 67Ga scintigram revealed uptake at the site of the chronic pyothorax. Cytological findings of the pleural effusion included many atypical lymphocytes. We suspected the presence of a malignant lymphoma and performed a biopsy under thoracoscopy, but could not arrive at a diagnosis. Therefore, resection of the chronic empyema was performed. Histological examination demonstrated the layer of lymphoma cells covering the wall of empyema between the layers of necrotic and connective tissue. Lymphoma cells were stained with L 26, which is known as a B cell marker. We diagnosed diffuse large cell lymphoma (B cell type). No case like this case has ever been published of malignant lymphoma bearing a layer of lymphoma cells. This case is thought to show early-phase malignant lymphoma complicated with chronic pyothorax after artificial pneumothorax. Malignant lymphoma should be suspected when chronic pyothorax undergoes enlargement, even if CT scanning or MRI does not show typical findings.

Aged↗
PubMed2000

[Disseminated MALT lymphoma associated with macroglobulinemia].

We report a case of disseminated MALT lymphoma with macroglobulinemia in an 80-year-old man who presented with a persistent fever. A radiograph of the chest showed infiltration of the left lung and pleural effusion of the right lung. The fluid contained numerous atypical lymphoid cells, which were positive for CD19, CD20, and HLA-DR, and negative for CD5 and CD10. Analysis of a pleural biopsy sample demonstrated no abnormality. A CT scan of the abdomen showed extensive thickening of the wall of the stomach adjacent to a peritoneal mass. Endoscopic examination disclosed antral ulceration. Histopathological examination of gastric samples revealed infiltration by centrocyte-like cells and lymphoepithelial lesions. Serum electrophoresis detected a macroglobulin peak at 34.5 g/l, and immunoelectrophoresis revealed an IgM kappa component. A bone marrow aspirate showed infiltration by the same lymphoid cells as those in the pleural fluid. A chromosome study of the lymphoid cells from both the bone marrow and pleural fluid showed a normal karyotype. The final diagnosis was MALT lymphoma involving the stomach, lungs and bone marrow. The patient did not consent to chemotherapy, and instead was given oral prednisolone. He died of respiratory distress one year and four months after diagnosis. Autopsy revealed wide dissemination of the tumor cells.

Aged↗
PubMed2000

[Pulmonary Mycobacterium gordonae infection treated with clarithromycin].

We reported a case of 51-year-old female immunocompetent patient with pulmonary Mycobacterium gordonae infection. The patient complained persistent cough and sputum and occasionally hemosputum. Chest radiograph and computed tomography (CT) of the lung showed bronchiectasis and small nodules in middle lobe. Bronchofiberscopy was performed twice, and bronchial washing specimen repeatedly revealed acid-fast bacilli. The organism was identified as Mycobacterium gordonae by biochemical tests and direct sequence method. She was treated with clarithromycin (400 mg/day) over 6 months and the chest CT findings showed improvement. The case was considered to be sensitive to clarithromycin in vitro drug susceptibility test. The case suggested that clarithromycin was a useful therapeutic agent to Mycobacterium gordonae infection.

Clarithromycin↗
PubMed1999

Exposure of rat thymocytes to hydrogen peroxide increases annexin V binding to membranes: inhibitory actions of deferoxamine and quercetin.

Effects of hydrogen peroxide (H(2)O(2)) on rat thymocytes were examined, using a flow cytometer and three fluorescent probes, annexin V-fluorescein isothiocyanate (annexin V-FITC) for detecting phosphatidylserine expressed on the membrane surface, ethidium bromide for estimating dead cells, and fluo-3-acetoxymethyl ester (fluo-3-AM) for monitoring changes in intracellular Ca(2+) concentration ([Ca(2+)](i)), to characterize H(2)O(2)-induced cytotoxicity. Exposure to H(2)O(2) (30 microM or more) increased the number of annexin V-positive live cells dose- and time-dependently while the number of dead cells increased at concentrations of 1 mM or more. H(2)O(2) (30 microM or more) increased [Ca(2+)](i) in a dose-dependent manner. Threshold concentration of H(2)O(2) to increase [Ca(2+)](i) was similar to that to increase annexin V binding to membranes. The H(2)O(2)-induced change in cell membranes was attenuated under Ca(2+)-free conditions. Therefore, it is likely that Ca(2+) is involved in the H(2)O(2)-induced cytotoxicity. Deferoxamine was effective to protect the cells suffering from H(2)O(2)-induced oxidative stress, suggesting a contribution of hydroxyl radicals generated by the Fenton reaction. Quercetin also exerted a potent protective action on cells suffering from H(2)O(2)-induced oxidative stress. The results indicate that the exposure of rat thymocytes to H(2)O(2) at micromolar concentrations increases annexin V binding to cell membranes in a Ca(2+)-dependent manner, suggesting the possibility that the oxidative stress caused by H(2)O(2) (and/or hydroxyl radicals) induces apoptosis via increasing [Ca(2+)](i).

Animals↗
PubMed1999

Structural change of threonine 89 upon photoisomerization in bacteriorhodopsin as revealed by polarized FTIR spectroscopy.

The all-trans to 13-cis photoisomerization of the retinal chromophore of bacteriorhodopsin occurs selectively, efficiently, and on an ultrafast time scale. The reaction is facilitated by the surrounding protein matrix which undergoes further structural changes during the proton-transporting reaction cycle. Low-temperature polarized Fourier transform infrared difference spectra between bacteriorhodopsin and the K intermediate provide the possibility to investigate such structural changes, by probing O-H and N-H stretching vibrations [Kandori, Kinoshita, Shichida, and Maeda (1998) J. Phys. Chem. B 102, 7899-7905]. The measurements of [3-18O]threonine-labeled bacteriorhodopsin revealed that one of the D2O-sensitive bands (2506 cm(-1) in bacteriorhodopsin and 2466 cm(-1) in the K intermediate, in D2O exhibited 18(O)-induced isotope shift. The O-H stretching vibrations of the threonine side chain correspond to 3378 cm(-1) in bacteriorhodopsin and to 3317 cm(-1) in the K intermediate, indicating that hydrogen bonding becomes stronger after the photoisomerization. The O-H stretch frequency of neat secondary alcohol is 3340-3355 cm(-1). The O-H stretch bands are preserved in the T46V, T90V, T142N, T178N, and T205V mutant proteins, but diminished in T89A and T89C, and slightly shifted in T89S. Thus, the observed O-H stretching vibration originates from Thr89. This is consistent with the atomic structure of this region, and the change of the S-H stretching vibration of the T89C mutant in the K intermediate [Kandori, Kinoshita, Shichida, Maeda, Needleman, and Lanyi (1998) J. Am. Chem. Soc. 120, 5828-5829]. We conclude that all-trans to 13-cis isomerization causes shortening of the hydrogen bond between the OH group of Thr89 and a carboxyl oxygen atom of Asp85.

Aspartic Acid↗
PubMed1999

NUP98 is fused to PMX1 homeobox gene in human acute myelogenous leukemia with chromosome translocation t(1;11)(q23;p15).

The nucleoporin gene NUP98 was found fused to the HOXA9, HOXD13, or DDX10 genes in human acute myelogenous leukemia (AML) with chromosome translocations t(7;11)(p15;p15), t(2;11)(q35;p15), or inv(11)(p15;q22), respectively. We report here the fusion between the NUP98 gene and another homeobox gene PMX1 in a case of human AML with a t(1;11)(q23;p15) translocation. The chimeric NUP98-PMX1 transcript was detected; however, there was no reciprocal PMX1-NUP98 fusion transcript. Like the NUP98-HOXA9 fusion, NUP98 and PMX1 were fused in frame and the N-terminal GLFG-rich docking region of the NUP98 and the PMX1 homeodomain were conserved in the NUP98-PMX1 fusion, suggesting that PMX1 homeodomain expression is upregulated and that the fusion protein may act as an oncogenic transcription factor. The fusion to NUP98 results in the addition of the strong transcriptional activation domain located in the N-terminal region of NUP98 to PMX1. These findings suggest that constitutive expression and alteration of the transcriptional activity of the PMX1 homeodomain protein may be critical for myeloid leukemogenesis.

Cell Transformation, Neoplastic↗
PubMed1999

Increased anxiety and impaired pain response in puromycin-sensitive aminopeptidase gene-deficient mice obtained by a mouse gene-trap method.

A mouse mutation, termed goku, was generated by a gene-trap strategy. goku homozygous mice showed dwarfism, a marked increase in anxiety, and an analgesic effect. Molecular analysis indicated that the mutated gene encodes a puromycin-sensitive aminopeptidase (Psa; EC 3. 4.11.14), whose functions in vivo are unknown. Transcriptional arrest of the Psa gene and a drastic decrease of aminopeptidase activity indicated that the function of Psa is disrupted in homozygous mice. Together with the finding that the Psa gene is strongly expressed in the brain, especially in the striatum and hippocampus, these results suggest that the Psa gene is required for normal growth and the behavior associated with anxiety and pain.

Aminopeptidases↗
PubMed1999

The value of acute-phase protein measurements after curative gastric cancer surgery.

OBJECTIVE: To determine whether acute-phase protein measurement provides clinically useful information about tumor recurrence. PATIENTS AND METHODS: Acute-phase serum protein levels were measured at regular intervals in 43 patients who underwent curative gastrectomy for gastric cancer. At 12 months after surgery, patients were grouped according to the presence or absence of a C-reactive protein response, and were followed up for a minimum of 12 months or until death. RESULTS: There was a significant difference (P = .02) in a recurrence rate between patients with a C-reactive protein response (3 of 4 patients) and those without such a response (4 of 39 patients). Moreover, serum levels of C4 and alpha1-antitrypsin 12 months after surgery in patients who eventually recurred were significantly (P<.05) higher than those in a group without recurrence. CONCLUSION: An acute-phase protein response may be a predictive factor in the early stages of tumor recurrence. Acute-phase protein measurement provided clinically useful information about tumor recurrence after curative gastric cancer surgery.

Acute-Phase Proteins↗
PubMed1999

The role of recombinant human bone morphogenetic protein-2 in PLGA capsules at an extraskeletal site of the rat.

Bone morphogenetic protein-2 (BMP-2) is a member of the transforming growth factor-beta (TGF-beta) superfamily and has strong bone-inductive activity in vivo. To examine the role of BMP-2 in an extraskeletal site of rat using a controlled release system of peptides, we encapsulated the recombinant human BMP-2 (rhBMP-2) with poly(DL-lactide-co-glycolide) (PLGA) and implanted the rhBMP-2/PLGA capsules in the subcutaneous area of rats. Upon histochemical examination, it was found that bone-inducing cells having alkaline phosphatase (ALP) activity appeared around the capsules by the suitably released rhBMP-2. In addition, the temporal histological examination showed that direct bone formation without cartilage occurred in the process of this ectopic bone induction. These data indicate that the role of rhBMP-2 in the extraskeletal site of rats is to induce the differentiation of mesenchymal cells into the osteoblasts.

Alkaline Phosphatase↗