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Biomedical subjects

T Morikawa

Publications and source records attributed to T Morikawa.

At least 109 records · Page 6Linked to original sources
PubMed1999

Gamma Knife radiosurgery for metastatic brain tumor: the usefulness of repeated Gamma Knife radiosurgery for recurrent cases.

Forty-one patients with a total of 193 metastatic brain tumors were treated because of new lesions or in a few cases because of tumor regrowth. The management involved two to four treatments with Gamma Knife radiosurgery (GKRS). The overall median survival was 15 months. The local control rate of tumors was 89% for the first treatment and 93% for repeated treatments. Symptomatic radiation-induced edema appeared in only two cases (4.9%). Patients with metastatic brain tumors who developed new lesions after GKRS were treated with GKRS alone for subsequent lesions. It was possible to control tumors for a long period with minimal side effects. As a result, we were able to maintain the quality of life of these patients, but, the effect of GKRS in controlling tumor regrowth seemed temporary.

Actuarial Analysis↗
PubMed1999

Medicinal flowers. I. Aldose reductase inhibitors and three new eudesmane-type sesquiterpenes, kikkanols A, B, and C, from the flowers of Chrysanthemum indicum L.

The methanolic extract from the flowers of Chrysanthemum indicum L., Chrysanthemi Indici Flos, was found to show inhibitory activity against rat lens aldose reductase. By bioassay-guided separation, the active components, such as flavone and flavone glycosides, were isolated from the extract together with three new eudesmane-type sesquiterpenes, kikkanols A, B, and C. The structures of kikkanols A, B, and C were elucidated on the basis of chemical and physicochemical evidence, which included application of the modified Mosher's method.

Aldehyde Reductase↗
PubMed1999

Prevalence and characterization of hepatitis C virus in hemodialysis patients.

OBJECT: Chronic hepatitis C virus (HCV) infection is common in hemodialysis (HD) patients. In the present study, the prevalence and properties of HCV in HD patients were analyzed. METHODS AND RESULTS: Of 125 HD patients, 34 (27%) were positive for antibody to HCV, and HCV-RNA was detected in 23 (68%) of the 34 patients using reverse transcription polymerase chain reaction. The HCV-RNA sequence analysis did not identify the alterations specific to HD patients with HCV, although one patient had a variant virus containing the deletion of the core gene sequence. When serial changes in the levels of HCV-RNA were evaluated in 15 patients by a branched DNA assay, the values decreased immediately after HD procedure, but returned to the baseline values 2 days after the procedure. CONCLUSION: These results indicate that HCV in HD patients is replication-competent, although a transient reduction in the levels of HCV-RNA occurs during HD.

Adult↗
PubMed1999

[CT diagnosis of hyperdense intracranial neoplasms: review of the literature].

In contrast to typical astrocytic tumors that show hypodense areas on computed tomographic images, some intracranial tumors show hyperdense areas on CT images. The major reasons for hyperdensity on CT images are hypercellular lesions, intratumoral calcification, and intratumoral hemorrhage. Malignant lymphomas, germinomas, and medulloblastomas show homogeneous hyperdensity on CT images because of their hypercellularity. Tumorous lesions such as subependymal giant cell astrocytomas, oligodendrogliomas, ependymomas, central neurocytomas, craniopharyngiomas, and meningiomas often present with hyperdense calcified lesions on CT images. Intratumoral hemorrhage also causes hyperdensity on CT images, and is often associated with metastatic brain tumors, glioblastomas, pituitary adenomas, and rarely with any of the other intracranial tumors. Although magnetic resonance imaging is now the major diagnostic tool for diseases of the central nervous system, the first imaging studies for patients with neurologic symptoms are still CT scans. Hyperdense areas on CT images are a clue to making an accurate diagnosis of intracranial neoplasms.

Adult↗
PubMed1999

Selective distal splenorenal shunt without requiring splenopancreatic disconnection with the use of the external iliac vein graft: a preliminary report.

BACKGROUND: Distal splenorenal shunt (DSRS) with splenopancreatic disconnection (SPD) is an ideal operation for permanent control of variceal bleeding. However, it is a very complicated procedure, and DSRS without SPD has a functional disadvantage: It gradually loses its selectivity and portal blood flow. To overcome these conditions, we designed a new technique--modified DSRS, which is easy to perform and maintains long-term selectivity of the shunt. METHODS: Modified DSRS was performed by using an external iliac vein graft without treating small pancreatic tributaries of the splenic vein. It was applied in 4 cases, and shunt patency and selectivity were examined by angiography during follow-up periods (6-76 months). RESULTS: Modified DSRS was technically more feasible and less complicated than DSRS with SPD. Every attempt was successful. There was no operative mortality, and all the patients were discharged from the hospital in good condition. The shunts were patent in all of them, and the selectivity of the shunt was maintained better in comparison to standard DSRS. CONCLUSIONS: Modified DSRS is a much easier and safer technique than standard DSRS. We consider this procedure to be the best method for surgical management of portal hypertension causing esophageal and gastric varices.

Esophageal and Gastric Varices↗
PubMed1999

[Surgical analysis for small cell lung cancer of the lung].

Clinical features of small cell lung cancer were studied in 15 cases. The overall 5-year survival rate of the patients with limited small cell lung cancer was 11.4%. Surgery played substantial role for long-term survival in limited SCLC. The 4-year-survival rate of the patients in stage I was 50%, and that of those in stage II and IIIA was 50% and 37.5%, respectively. In the two survivors over four years in stage IIIA, all tumor was categorized as pT3 disease. The 4-year-survival rate of the patients treated with PE was 100%, and that of those treated with another chemotherapy was 10%, and that difference is statistically significant (p < 0.05). There was no significant difference in prognosis of patients in any other factors such as location (central or peripheral), histological subtype, curability or R number, pT factor, pN factor, p stage or with or without thoracic irradiation. Surgical resection for limited SCLC should be recommended in patients with stage I, II and T3N0M0 or T3N1M0 disease. For the patients in stage IIIA, particularly in N2M0 disease, who showed partial response or no change after chemotherapy, surgery should be considered because those patients might have nonsmall cell carcinoma components.

Adult↗
PubMed1999

Long-term benefits for the quality of life after video-assisted thoracoscopic lobectomy in patients with lung cancer.

Quality of life (QOL) after video-assisted thoracic surgical (VATS) lobectomy remains to be defined. Forty-four consecutive patients with clinical stage I lung cancer underwent lobectomy by the VATS approach (n = 22 patients) or thoracotomy approach (n = 22 patients). Acute pain was quantitated by postoperative narcotic requirements and the need for epidural anesthesia. Long-term QOL was assessed by questioning patients about the presence of chronic chest pain, ongoing limitations in arm or shoulder function, time until return to preoperative activity, and satisfaction with the operation. Patients who underwent VATS lobectomy had significant decreases in both acute and chronic chest pain and time until return to preoperative activity. Patients also had more confidence regarding wound size and their overall impression of the operation. In this series, VATS lobectomy was associated with long-term benefits for the QOL in patients with lung cancer. However, the exact role of this approach should be defined by carefully-designed controlled trials studying long-term survival.

Adult↗
PubMed1998

Inhibitory effect and action mechanism of sesquiterpenes from Zedoariae Rhizoma on D-galactosamine/lipopolysaccharide-induced liver injury.

Hepatoprotective sesquiterpenes were isolated from the aqueous acetone extract of Zedoariae Rhizoma, the rhizome of Curcuma zedoaria ROSCOE (Zingiberaceae). Principal sesquiterpenes, furanodiene, germacrone, curdione, neocurdione, curcumenol, isocurcumenol, aerugidiol, zedoarondiol, and curcumenone and curcumin were found to show potent protective effect on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced acute liver injury in mice. Plausible action mechanisms for their hepatoprotective activity were clarified on the basis of the inhibitory effect on D-GalN-induced cytotoxicity in primary cultured rat hepatocytes, LPS-induced NO production in cultured mouse peritoneal macrophages, and D-GalN/tumor necrosis factor-alpha (TNF-alpha)-induced liver injury in mice.

Animals↗
PubMed1998

Frequent loss of gelsolin expression in non-small cell lung cancers of heavy smokers.

Most lung and bladder cancers have been shown to be associated with smoking. We have previously demonstrated the frequent loss of gelsolin expression and its tumor suppressor activity in bladder cancer (M. Tanaka et al., Cancer Res., 55: 3228-3232, 1995). Here, we examined gelsolin expression in 12 cultured non-small cell lung cancer (NSCLC) cell lines. Furthermore, we analyzed gelsolin expression in relation to patients' smoking habits in 88 surgically resected NSCLCs to investigate whether gelsolin could be a molecular target for tobacco-induced carcinogenesis of lung cancer. All 12 NSCLC cell lines showed low-to-undetectable expression of the gelsolin gene, compared to that in normal lung tissue, by Northern blot analysis. On the other hand, Southern blot analysis of genomic DNA did not show any gross rearrangements or deletions of the gene in the NSCLC cell lines. Western blot analysis of gelsolin expression showed low-to-undetectable gelsolin expression in all 12 NSCLC cell lines, compared to normal lung tissue. Immunocytochemical analysis of gelsolin expression in NSCLC cell lines showed results that were consistent with those obtained by Western blot analysis, using normal bronchial epithelial cells as a positive control: two cell lines with lower gelsolin expression by Western blot analysis had reduced but positive cytoplasmic immunostaining of gelsolin, compared with primary normal bronchial epithelial cells, whereas no such immunostaining was observed in two cell lines with much lower or undetectable gelsolin expression by Western blot analysis. Therefore, gelsolin expression was analyzed in surgically resected NSCLCs by immunohistochemistry. Reduced or undetectable gelsolin expression was observed in 48 of 88 (55 %) resected NSCLCs. Such altered gelsolin expression significantly correlated with heavy smoking of patients (> or =20 pack-years; P = 0.008 by the chi2 test and P = 0.03 by multivariate logistic regression analysis), whereas there was no significant correlation between gelsolin expression and histological type, pathological tumor-node-metastasis (pTNM) stage, or survival. These findings suggest that the frequent loss of gelsolin expression may be involved in the development of NSCLCs as a potential molecular target of tobacco-induced carcinogenesis.

Aged↗
PubMed1998

Lobectomy: video-assisted thoracic surgery versus posterolateral thoracotomy.

BACKGROUND: Video-assisted lobectomy has been adopted by many thoracic surgeons, because it is a less invasive approach to small peripheral lung cancers. However, some authors disagree that video-assisted lobectomy is less invasive than traditional thoracotomy and lobectomy. The purpose of this study was to evaluate the advantages of video-assisted lobectomy over posterolateral thoracotomy and lobectomy in terms of pain-related morbidity. METHODS: A total of 70 patients with clinical T1N0M0 non-small-cell lung carcinomas underwent lobectomy with complete mediastinal lymphadenectomy. Of these 35 underwent posterolateral thoracotomy (between April 1994 and December 1995; open group), and 35 underwent video-assisted thoracic surgery (VATS) (between January and December 1996; VATS group). RESULTS: Although the operative time was significantly longer in the VATS group (p = 0.04), the intraoperative blood loss was significantly less (p = 0.03). No significant differences were found for the two groups with respect to the total number of mediastinal lymph nodes dissected or duration of chest tube drainage. Postoperative pain was less severe as determined by the number of doses of analgesics required between postoperative days 0 and 7 (p < 0.0001), and the length of postoperative hospitalization was shorter in the VATS group (p < 0.0001). CONCLUSION: Video-assisted lobectomy is associated with decreased postoperative pain and shortened length of postoperative hospitalization, when compared with posterolateral thoracotomy and lobectomy.

Adult↗
PubMed1998

Experimental study of tracheal patch reconstruction with a covered expandable metallic stent.

BACKGROUND: We evaluated the efficacy of tracheal patch reconstruction with a covered expandable metallic stent (EMS) with omentoplasty. METHODS: After resecting the right half of the circumferential wall of two tracheal rings in adult beagle dogs, we inserted a covered EMS to reconstruct the defect interiorly. Then, through laparotomy, we made an omental pedicle flap and wrapped it around the EMS-interposed area. For comparison with the group without omentoplasty, we periodically examined the healing process macroscopically and histologically. RESULTS: Bronchofiberscopic observations revealed that incorporation of the covered EMS progressed with the passage of time and tracheal luminal patency was maintained well in both groups. However, polyplike granulation developed gradually at both ends of the EMS. Histologically, epithelium was regenerated in the patched area 4 weeks postoperatively and the area was covered with pseudostratified ciliated epithelium at 12 weeks postoperatively. Quantitative analysis of the macroscopic and histologic findings showed that the inflammatory polyps were reduced and epithelialization was promoted in the group with omentoplasty. CONCLUSIONS: Tracheal patch reconstruction with a covered EMS, when combined with omentoplasty, promoted early epithelial regeneration and suppressed the development of inflammatory polyps.

Animals↗
PubMed1998

[Pneumonia caused by granulomatous Pneumocystis carinii in a patient with the acquired immunodeficiency syndrome].

A 54-year-old man was admitted to the hospital because of fever and general fatigue. A chest roentgenogram on admission showed lobular opacities and ill-defined opacities in both lower lobes. The pneumonia was successfully treated with antibiotics. The acquired immunodeficiency syndrome was diagnosed because ELISA and PCR tests for antibodies to the human immunodeficiency virus were positive and the CD 4+ lymphocyte count was 39 per cubic millimeter. Examination of bronchoalveolar lavage fluid revealed no Pneumocystis carinii. Trimethoprim and sulfamethoxazole were given prophylactically, but were withdrawn because of a rash. The patient began to receive aerosolized pentamindine and was discharged. On the next day, he was readmitted to the hospital because of a high fever. A chest roentgenogram showed diffuse miliary opacities. Chest CT scan also showed diffuse small nodular opacities in both lungs. Examination of a transbronchial biopsy specimen revealed well-defined, noncaseating granulomas with pneumocystis organisms in their centers. Cultures for tuberculosis and fungi were all negative. We diagnosed granulomatous pneumonia caused by Pneumocystis carinii, which is an atypical manifestation of Pneumocystis carinii pneumonia. The patient died of sepsis and cardiac tamponade. Microscopically, the lung tissue was found to have foamy intra-alveolar exdates, which is a typical histological feature of Pneumocystis carinii pneumonia.

AIDS-Related Opportunistic Infections↗
PubMed1998

Technical feasibility of video-assisted lobectomy with radical lymphadenectomy for primary lung cancer.

The morbidity and mortality for video-assisted curative resection of lung cancer was evaluated retrospectively. Forty-one consecutive patients with stage I and II lung cancer underwent video-assisted curative lobectomy with complete hilar and mediastinal lymphadenectomy. Conversion to an open procedure was necessary in two patients. The operating times for the second half of the series were shorter than for the first half. Compared with patients receiving a standard open procedure, the video-assisted patients experienced satisfactory results. We conclude that video-assisted curative lobectomy with complete lymphadenectomy for stage I and II lung cancer is technically feasible in the majority of patients, although follow-up is required to determine the long-term prognosis. Comparative series between video-assisted and open procedures should not be conducted until the surgeon has acquired the necessary video-assisted skills. A prospective randomized trial will determine the actual value of video-assisted procedure for lung cancer treatment.

Adult↗
PubMed1998

[Pulmonary actinomycosis with "balls-in-a hole" appearance diagnosed by examination of bronchial lavage fluid].

A 49-year-old man was referred to our hospital because of abnormal chest X-ray findings. Chest X-ray films showed infiltrative opacities in the right lung, and histological findings of a transbronchial biopsy specimen showed non-specific inflammation. The patient was treated with Ofloxacin for one month. After the treatment, chest X-ray films showed that the infiltrative opacities in the right upper lobe had decreased, but that opacities in the right lower lobe had increased, with an air meniscus sign. A chest computed tomography scan at the same time revealed that the remaining opacities contained multiple mass-like lesions within a cavity in the right S6, appearing as "balls in a hole". One year after the first visit, the patient visited the hospital again because of cough and sputum. A chest X-ray film showed that the size of the cavity in the right lower lobe had increased. The histological findings from a fresh transbronchial biopsy specimen revealed a non-specific inflammation again; however, black clots obtained from bronchial lavage fluid after biopsy were histologically identified as sulfur granules, a classic pathological indication of actinomycosis. This confirmed the diagnosis of pulmonary actinomycosis. The patient was treated with penicillin, and the opacities in the right lower lobe subsided.

Actinomycosis↗
PubMed1997

Isolation and characterization of D-threonine aldolase, a pyridoxal-5'-phosphate-dependent enzyme from Arthrobacter sp. DK-38.

D-Threonine aldolase is an enzyme that catalyzes the cleavage of D-threonine into glycine and acetaldehyde. Its activity was found in several genera of bacteria such as Arthrobacter, Alcaligenes, Xanthomonas, and Pseudomonas, but not in yeasts or fungi. The enzyme was purified to homogeneity from one strain, Arthrobacter sp. DK-38. The enzyme appeared to consist of a single polypeptide chain with an apparent molecular mass of 51 kDa. This enzyme, as well as L-threonine aldolase, requires pyridoxal 5'-phosphate (pyridoxal-P) as a coenzyme. Unlike other pyridoxal-P enzymes, D-threonine aldolase also requires a divalent cation such as Co2+, Ni2+, Mn2+, or Mg2+ for its catalytic activity. The enzyme completely lost its activity in the absence of either pyridoxal-P or a divalent cation. A divalent cation was also essential for the thermal stability of the enzyme. The metal-free enzyme tends to become thermally unstable, resulting in the irreversible loss of its catalytic activity. The enzyme is strictly D-specific for the alpha-position, whereas it cannot distinguish between threo and erythro forms at the beta-position. Thus, D-threonine and D-allothreonine act as substrates of the enzyme, but their kinetic parameters are different; the Km and Vmax values are 3.81 mM and 38.8 micromol x min(-1) x mg(-1) toward D-threonine, and 14.0 mM and 102 micromol x min(-1) x mg(-1) toward D-allothreonine. respectively. The aldolase reaction is reversible, and the enzyme is therefore able to produce nearly equimolar amounts of D-threonine and D-allothreonine through C-C bond formation between glycine and acetaldehyde. The enzyme also acts, in the same manner, on several other D-beta-hydroxy-alpha-amino acids, including D-beta-phenylserine, D-beta-hydroxy-alpha-aminovaleric acid, D-beta-3,4-dihydroxyphenylserine, and D-beta-3,4-methylenedioxyphenylserine.

Acetaldehyde↗
PubMed1997

Antithrombotic effects of NE-6505, a novel anion-binding exosite inhibitor.

NF-6505, a bi-O-Tyr-sulfated decapeptide, which specifically interacts with the anion-binding exosite of the thrombin molecule, was chemically synthesized and assessed for its antithrombotic effects in vitro and in vivo. The IC50 value of this peptide on fibrin-clot formation in vitro was about 0.05 microgram/ml, which indicated a potency similar to that of a recombinant hirudin. NF-6505 caused a 2-fold prolongation of activated partial thromboplastin time when intravenously administered at 1 mg/kg in rats. In a rat venous thrombosis model, a bolus intravenous administration of this peptide dose-dependently inhibited the thrombus formation with an ED50 value of 0.03 mg/kg, a value smaller than that of recombinant hirudin (ED50 = 0.1 mg/kg) or of argatroban (ED50 = 0.2 mg/kg). These results suggest that NF-6505 is a highly potent and safe agent for the clinical treatment of venous thrombosis diseases.

Amino Acid Sequence↗