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Biomedical subjects

T Kimoto

Publications and source records attributed to T Kimoto.

At least 37 records · Page 2Linked to original sources
PubMed1999

The efficiency of performing ultrasound-guided fine-needle aspiration biopsy following mass screening for thyroid tumors to avoid unnecessary surgery.

Thyroid masses are a common clinical finding, and their management remains controversial. The purpose of this study was to evaluate the clinical effect of performing routine ultrasound (US) examinations and US-guided fine-needle aspiration biopsy (US-FNAB) in the management of diffuse or nodular goiter diagnosed by mass screening. Mass screening carried out from 1993 to 1996 revealed 444 women with goiter, 322 of whom had diffuse goiter and 122 had nodular goiter. All of these patients underwent US examination, the results of which determined that 169 should undergo US-FNAB to confirm an accurate diagnosis of their thyroid tumors. Histological examinations after surgical resection revealed that 12 of the 322 patients with diffuse goiter (3.7%) and 23 of the 122 with nodular goiter (18.9%) had malignant tumors. Among the 61 thyroid tumors surgically verified, US-FNAB yielded a sensitivity rate of 93%, a specificity rate of 81%, and an accuracy rate of 90%. Insufficient aspiration was obtained from 5%. Performing US-FNAB-resulted in an elevation in the percentage of malignant tumors yielded at surgery of up to 72%. Thus, ultrasonography followed by US-guided-FNAB could be a useful routine method of evaluating thyroid tumors detected by mass screening. Moreover, a greater number of unnecessary thyroid operations can be avoided by performing US-FNAB rather than FNAB alone.

Biopsy, Needle↗
PubMed1999

Phosphorothioate oligonucleotides induction into experimental choroidal neovascularization by HVJ-liposome system.

PURPOSE: The purpose of this study was to determine whether the inactivated hemagglutinating virus of Japan (HVJ)-liposome method can induce phosphorothioate oligonucleotides effectively into an experimentally-induced choroidal neovascularization of rats. We also examined whether antisense phosphorothioate oligonucleotides against VEGF could be induced into choroidal neovascularization as a therapeutic agent by the HVJ-liposome method. METHODS: The experiments were conducted on a rat model of choroidal neovascularization. FITC-labeled phosphorothioate oligonucleotides were coencapsulated in liposomes. The liposomes were coated with the envelope of inactivated HVJ and injected into the vitreous cavity following photocoagulation of pigmented rat eyes. The eyes were removed following injection, fixed, frozen and cut into thin sections. Induction of oligonucleotides was observed under a laser confocal scanning microscope for fluorescence and the development of choroidal neovascularization was evaluated histopathologically. RESULTS: Phosphorothioate oligonucleotides were effectively induced into ganglion cells and into the cells of the choroidal neovascularization induced by laser photocoagulation. Highly effective induction of oligos was observed 3 to 14 days after intravitreal injection of HVJ-liposomes after which the level decreased. Antisense oligonucleotides against VEGF were induced specifically into cells in the choroidal neovascularization, however neovascularization was still observed. CONCLUSIONS: Phosphorothioate oligonucleotides can be effectively induced into ganglion cells, and specifically into cells in choroidal neovascularization. Although antisense oligonucleotides against VEGF failed to prevent choroidal neovascularization, the HVJ-liposome method provided a highly effective means of inducing antisense oligos for in vivo antisense therapy.

Animals↗
PubMed1999

Major compared with limited hepatic resection for hepatocellular carcinoma without underlying cirrhosis: a retrospective analysis.

OBJECTIVE: To find out if patients with hepatocellular carcinoma (HCC) with no underlying cirrhosis benefit from major hepatic resection. DESIGN: Retrospective study. SETTING: University hospital, Japan. PATIENTS: 58 patients without cirrhosis and with HCC 10 cm in diameter or less. INTERVENTIONS: 25 had major and 33 had limited hepatic resections. MAIN OUTCOME MEASURES: Overall and disease-free survival, and prognostic factors verified by univariate and multivariate analyses. RESULTS: 6 patients developed major complications (10%), two of whom died within 60 days of operation. There were no differences in postoperative morbidity and mortality between the two groups. The overall and disease-free survival were similar as was the incidence and pattern of intrahepatic tumour recurrence. Hepatitis B surface (HBs) antigen (positive), tumour size (smaller than 3 cm), and surgical margin (clear) were favourable indicators of disease-free survival on multivariate analysis. CONCLUSIONS: Major hepatic resection should not necessarily be done for HCC without cirrhosis but it is important to take an adequate surgical margin. Overall and disease-free survival are better in patients who are HBs-antigen positive than those who are negative because most of the latter are positive for hepatitis C virus.

Aged↗
PubMed1999

Effect of clarithromycin regimen for Mycobacterium avium complex pulmonary disease.

We have investigated the efficacy of a clarithromycin-containing four-drug regimen for Mycobacterium avium complex (MAC) pulmonary disease in 46 patients without acquired immunodeficiency syndrome (AIDS). The patients were 14 males and 32 females with a mean age of 60.9 +/- 11.5 yr. Patients received 10 mg/kg/d of clarithromycin plus ethambutol, rifampin, and initial kanamycin and subsequent quinolone for 24 mo. Seven patients (15.2%) were dropped in the first 6 mo. Among 39 patients who received more than 6 mo of therapy, 28 patients (71.8%) converted their sputa to negative: 26 of 31 patients (83.9%) infected with clarithromycin-susceptible strains and two of eight patients (25.0%) with resistant or intermediate strains. The timing of sputum conversion was 3.6 +/- 1.9 mo, with a range of 2 to 9 mo. The conversion rate was significantly lower in patients who were infected with clarithromycin-resistant or intermediate strains, who had had prior therapy (55.0% versus 89.5%), or who were acid-fast bacilli (AFB) smear-positive at entry (60.7% versus 100%). The age and sex of patients, the species of pathogen (M. avium or M. intracellulare), type and extent of the disease, and the use of kanamycin did not significantly affect the conversion rate. Although the regimen was efficacious for newly treated patients, frequent adverse reactions and a low conversion rate of sputum in retreated patients are problems that remain to be solved.

Adult↗
PubMed1999

Direct bone induction in the subperiosteal space of rat calvaria with demineralized bone allografts.

In order to clarify the understanding of bone induction with crude bone morphogenetic protein (BMP)-containing allografts in subperiosteal conditions, chondrogenesis and osteogenesis were histologically evaluated following the implantation of the demineralized bone (DB) in the subperiosteal space of calvaria of 30 Wistar rats. On the forehead of the rat, DB particles were placed onto the denuded calvarial bone and covered by the skin-periosteum flap without any perforations of the marrow space of the calvaria. Sintered hydroxylapatite particles (HA) were also placed as a control. In the DB group, new bone formation on the surface of calvaria was achieved between 2 and 8 weeks after the operation. However, no chondrogenesis was seen throughout the experimental period. In the HA implantation group, fibrous tissue encapsulation of HA particles was generally seen. These results suggest that DB containing crude BMP might have the capacity for direct osteoblast induction from undifferentiated mesenchymal progenitor cells in vivo in specific situations, that is, in a subperiosteal space of uninjured rat calvaria.

Animals↗
PubMed1999

[Effects of local administration of interferon-beta on proliferation of the retinal pigment epithelium].

PURPOSE: We demonstrated effects of local administration of human interferon (IFN)-beta on the repair process of the rabbit retinal pigment epithelium (RPE). MATERIAL AND METHODS: We used adult pigmented rabbits in this experiment. We measured IFN-beta levels in the ocular tissues after sub-Tenon administration of human IFN-beta by means of enzyme-linked immunosorbent assay (ELISA) methods. Laser photocoagulation in moderate intensity was applied after IFN administration. The repair process of the RPE in laser lesion sites was examined histopathologically. RESULTS: Locally administrated IFN spread by diffusion into the intraocular tissues. The highest IFN level was detected in the choroid. In eyes treated with IFN, RPE cells proliferated vigorously to the center of the photocoagulated lesions on early stages after laser photocoagulation. Proliferation of RPE cells after laser photocoagulation was remarkable in eyes treated with large amounts of IFN. CONCLUSION: It was demonstrated histopathologically that sub-Tenon administration of IFN-beta promoted proliferation of RPE cells during the repair process after laser photocoagulation.

Administration, Topical↗
PubMed1999

[Severe adult-type Williams-Campbell syndrome (Williams-Campbell-type bronchiectasis)].

A 70-year-old man was admitted to our hospital because of dyspnea. Arterial blood gas analysis indicated severe type-II respiratory failure. Williams-Campbell-type bronchiectasis was suspected because chest radiographs disclosed multiple cystic shadows in both lungs. Although inspiratory chest radiographs and computed tomographic (CT) scans showed cystic bronchiectasis, expiratory chest radiographs and CT scans demonstrated characteristic collapse of the ectatic bronchi. Continuous fluoroscopic visualization of the respiratory phase demonstrated bronchial dilatation during inhalation and collapse during exhalation. Williams-Campbell-type bronchiectasis was diagnosed on the basis of the radiological findings. Compared with previous cases of Williams-Campbell syndrome reported in Japan, this case was interesting because the patient exhibited severe respiratory failure and because the dilatating and collapsing bronchi were demonstrated by fluoroscopy.

Aged↗
PubMed1998

Correlation analysis between fatty acid compositions of zooplankter individuals, fed on different phytoplankton species by means of pyrolysis-gas chromatography combined with on-line methylation.

Pyrolysis-gas chromatography (Py-GC) combined with on-line methylation was applied to a correlation analysis between the distributions of fatty acid components in the lipids of zooplankter individuals and those of ingested algae using principal component analysis (PCA). Py-GC in the presence of organic alkali, tetramethylammonium hydroxide (TMAH), was used to estimate the apparent distributions of fatty acid components contained in a single individual zooplankter weighing several tens of micrograms and a small sample size of ingested algae samples in the order of 10 microg. The observed fatty acid compositions were used as a database for the PCA in order to discriminate the zooplankton and ingested algae samples. The result obtained indicated that the fatty acid compositions of zooplankton individuals used in this work were significantly reflected in those of their ingested food in spite of some contribution from isomerization and/or elongation of fatty acid components during digestion of the ingested algae phytoplankton in living zooplankters.

Animals↗
PubMed1998

Nucleotide sequences of the matrix protein gene of subacute sclerosing panencephalitis viruses compared with local contemporary isolates from patients with acute measles.

Measles viruses isolated from brain cells of patients with subacute sclerosing panencephalitis (SSPE) have numerous mutations, especially in the matrix protein (M) gene. To find whether the M genes of these SSPE viruses were mutated randomly or in a pattern, we sequenced this gene from three strains of defective measles virus isolated in Osaka, Japan. We could deduce the sequence of the possible progenitor measles virus for each patient by comparison of the isolate with measles viruses prevailing at roughly the same time and place as the primary infection. Biased hypermutation affected the M genes of all three SSPE viruses, although the molecular mechanisms for the mutations might be various. Replacements of U with C in the plus strand accounted for 76% of all mutations in two of the strains, but in the other strain, replacements of A with G accounted for 52% of the mutations, and the U residues were unchanged.

Acute Disease↗
PubMed1998

Percutaneous long-term arterial access with implantable ports. Direct subclavian approach with US.

PURPOSE: To clarify the clinical feasibility of getting a long-term arterial access at the subclavian region by directly puncturing the artery under ultrasound guidance. MATERIALS AND METHODS: Percutaneous placements of arterial infusion catheters with implantable ports were performed in 30 patients with malignant abdominal tumors. The axillary artery in the subclavian region was punctured directly with an 18G needle under ultrasound guidance. Using the Seldinger technique, a 5Fr catheter was placed with its tip in the hepatic or the other tumor-supplying arteries. The catheter was connected to an implantable port, and both of them were embedded in the subcutaneous pocket. RESULTS: Percutaneous placements of infusion catheters were successfully performed in 29 cases. Transarterial chemotherapy through implanted ports was done uneventfully in 26 patients, while in the other three cases, catheter dislodgment occurred. Two local haematomas, one wound infection and one cerebellar infarction were also experienced. CONCLUSION: Ultrasound-guided subclavian approach is a minimally invasive way of implanting an infusion catheter for chemotherapy, although its indication for severely atherosclerotic patients should be limited.

Abdominal Neoplasms↗
PubMed1998

Apoptosis and suppression of tumor growth by artepillin C extracted from Brazilian propolis.

Artepillin C was extracted from Brazilian propolis. Artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) has a molecular weight of 300.40 and possesses antibacterial activity. When artepillin C was applied to human and murine malignant tumor cells in vitro and in vivo, artepillin C exhibited a cytotoxic effect and the growth of tumor cells was clearly inhibited. The artepillin C was found to cause significant damage to solid tumor and leukemic cells by the MTT assay, DNA synthesis assay, and morphological observation in vitro. When xenografts of human tumor cells were transplanted into nude mice, the cytotoxic effects of artepillin C were most noticeable in carcinoma and malignant melanoma. Apoptosis, abortive mitosis, and massive necrosis combined were identified by histological observation after intratumor injection of 500 microg of artepillin C three times a week. In addition to suppression of tumor growth, there was an increase in the ratio of CD4/CD8 T cells, and in the total number of helper T cells. These findings indicate that artepillin C activates the immune system, and possesses direct antitumor activity.

Animals↗
PubMed1998

Pathological observations during treatment with the biological response modifier Maruyama vaccine in cancer: implications for collagen production in the prevention of cancer invasion and metastasis.

The antitumor effects of Maruyama vaccine (SSM) include the activation of immunocompetent cells and promotion of collagen production in tumors, thereby acting as a biological response modifier (BRM). On the basis of clinical observations of patients responding to treatment with SSM long term, experiments in vitro and in vivo have been conducted to define the mechanisms of action of SSM, and the results indicate that SSM does not exhibit direct cytotoxic effects on cancer cells, but that it accelerates a marked production of collagen fibers and acts as a BRM. Proliferating collagen fibers consist of type IV collagen inside tumor tissues, and types I and III collagens and fibronectin around tumor tissues encapsulating tumors and their metastasis, and possibly inducing necrosis in certain malignancies. These dense collagen fibers arise from the stroma, cancer cells themselves, and extracellular matrices confined within the cancerous lesion. After treatment with SSM, patients and experimental animals bearing tumors remained alive with tumors long term. We conclude from these results that SSM acts by inducing encapsulation of tumor growths, possibly preventing their spread and metastasis, and that SSM may benefit patients in whom tumor is inoperable and resistant to conventional chemotherapy.

Adenocarcinoma↗
PubMed1998

Expression of vascular endothelial growth factor and its receptor, KDR, following retinal ischemia-reperfusion injury in the rat.

PURPOSE: There is considerable evidence that vascular endothelial growth factor (VEGF) mediates ocular neovascularization in retinal vascular diseases. We investigated the time-dependent changes in the expression of VEGF and its receptor KDR/ Flk in a transient retinal ischemia-reperfusion injury model. METHODS: Transient retinal ischemia was induced by increasing the intraocular pressure in albino rats eyes for 45 min. In situ hybridization was used to identify the retinal cells synthesizing VEGF mRNA and KDR mRNA at various times following reperfusion. Immunohistochemical analysis was also carried out to detect VEGF immunoreactivity. RESULTS: In the control, non-ischemic retinas, signals for VEGF mRNA and KDR mRNA were observed in the cells of the ganglion cell layer. Immunoreactivity to VEGF was also found in the nerve fiber layer, the ganglion cell layer, and the retinal pigment epithelial (RPE) cell layer. Immediately and 6 h after reperfusion, VEGF and KDR mRNA expression was markedly decreased, but recovered by 24 h to the levels observed in normal retinas. Immunoreactivity for VEGF was also decreased immediately and 6 h after reperfusion, and was detected in the endothelial cells of the retinal vessels after 24 h. Immunoreactivity to VEGF recovered by 48 h after reperfusion. CONCLUSIONS: The hybridization pattern of VEGF and KDR mRNA in the ganglion cell layer strongly suggests that the ganglion cells are the major source of this growth factor. The decrease of VEGF mRNA, KDR/Flk mRNA and VEGF protein levels after ischemia and recovery after reperfusion suggest that transient hypoxia might mediate short-term down-regulation of VEGF and KDR mRNA.

Animals↗
PubMed1998

Modification of results of drug susceptibility tests by coexistence of Mycobacterium avium complex with Mycobacterium tuberculosis in a sputum sample: case report and experimental considerations.

We report on a patient whose sputum contained both Mycobacterium tuberculosis and Mycobacterium avium complex (MAC). The MAC failed to be detected by the PCR-based AMPLICOR test. The unrecognized coexistence of MAC in the sample modified the results of drug susceptibility tests. Experiments revealed that the presence of both M. tuberculosis and MAC was not detected by the AMPLICOR test under certain conditions.

Humans↗
PubMed1998

Inferior vena caval thrombosis after traumatic liver injury.

We report here the case of a 35-year-old man who presented with inferior vena cava thrombosis (IVCT) after blunt hepatic trauma. The IVCT was incidentally detected by computed tomography (CT) 35 days after deep parenchymal suturing and suture approximation for liver lacerations. The patient denied any symptoms of thrombophlebitis. However, he had presented with significantly elevated values of FDP-D-dimer and a modest increase in plasminogen concentration, which indicated that he had been in a hypercoagulable and hypofibrinolytic state after the operation. He had not undergone any prophylactic anticoagulant therapy because of his concomitant subarachnoid hemorrhage and huge hepatic hematoma. The patient was treated with an emercy thrombectomy. Posttraumatic IVCT is extremely rare phenomenon. We should consider IVCT in patients with a severe hepatic injury, particularly if their coagulation system change into hypercoagulable and hypofibrinolytic state. Additionally, this case made us reflect on the treatment of traumatic liver injury.

Adult↗
PubMed1998

Continuous administration of basic fibroblast growth factor (FGF-2) accelerates bone induction on rat calvaria--an application of a new drug delivery system.

Some studies have shown that locally applied basic fibroblast growth factor (FGF-2) enhances bone regeneration at a fracture site, while others have not been in agreement. We developed a new continuous FGF-2 delivery system designed to accelerate cytokine-induced new bone formation. A subperiosteal pocket was surgically formed in 36 eight-week-old male Wistar rats. The rats were administered 0, 1, 10, or 100 ng of FGF-2 contained in a collagen minipellet, mixed with allogeneic demineralized bone matrix in a dome-shaped Millipore filter and then placed into the pocket. New bone formation in the dome was evaluated at 2, 4, and 8 wks after placement. Soft x-ray radiographs disclosed an apparently larger radiopaque region in the 1-ng group at 4 wks compared with those in the other groups. Morphometrical analysis revealed that the new bone area in the 1-g group was significantly larger than that in the 0-g group (p<0.01). In the 100-ng FGF-2 group, new bone formation seemed suppressed. We concluded that continuous slow administration of a small amount of FGF-2 accelerates bone-derived osteogenic cytokine-induced new bone formation.

Animals↗
PubMed1998

Polypoid bronchial lesions due to Scedosporium apiospermum in a patient with Mycobacterium avium complex pulmonary disease.

A 69 yr old female was hospitalized for further examination of abnormal shadows on chest radiographs. She had a history of tuberculous pleurisy, rheumatoid arthritis and gold-induced interstitial pneumonia. On admission she still suffered from rheumatoid arthritis. A chest computed tomography scan on admission showed clusters of small nodules in subpleural regions of both lungs combined with bronchiectasis. Mycobacterium avium complex was cultured repeatedly from the sputum. Bronchoscopic examination disclosed white-yellow polypoid lesions in the orifice of the left B4 bronchus. Cultures of the brushing specimen of the polypoid lesions and bronchial aspirates from the B4 bronchus yielded smoky-grey mycelial colonies that were later identified as Scedosporium apiospermum. It was concluded that the polypoid bronchial lesions due to Scedosporium apiospermum were formed in the preexisting dilated bronchus caused by Mycobacterium avium complex pulmonary disease.

Aged↗