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Biomedical subjects

T Furuta

Publications and source records attributed to T Furuta.

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

Opportunistic Pneumocystis carinii infection in red-bellied tamarins (Saguinus labiatus).

P. carinii infection in red-bellied tamarins (Saguinus labiatus), born and maintained in a laboratory breeding colony, was examined by histopathologic examination postmortem. P. carinii cysts were detected in 6 of 10 red-bellied tamarins examined, by using Grocott's, toluidine blue O and immunostaining with avidin-biotin complex using antisera for rat-, simian-, and human-P. carinii. The results obtained from the present studies imply that P. carinii may be an important pathogen in this species.

Animals↗
PubMed1999

Effect of intracarotid infusion of etoposide: modification of the permeability of the blood-brain barrier and the blood-tumor barrier in rat brain tumor model.

The effect of intracarotid infusion of etoposide on the permeability of the blood-brain barrier (BBB) and brain-tumor barrier (BTB) was investigated using a model of rats injected with C6 glioma cells. Fifty four glioma-bearing rats were divided into 3 groups and treated with 0, 3, or 15 mg/kg of etoposide infused into the internal carotid artery. BBB or BTB permeability was evaluated qualitatively by the leakage of Evans blue (6 animals in each group) or quantitatively by the diffusion of carboplatin [cis-diammine (1,1-cyclobutane-dicarboxylato) platinum(II); CBDCA] (12 animals in each group) into the normal brain or the tumor tissue. BBB and BTB disruption augmented significantly in proportion to the dose of etoposide. The degree of disruption of BTB was greater than that of BBB, but the rate of disruption of BBB in proportion to increasing the dose of etoposide was higher than that in the BTB. Histopathologically, no obvious changes were observed in the animals of either the control group or the 3 mg/kg group but degenerative changes in the neurons of the hippocampus of the infused hemisphere were seen in the 15 mg/kg group. This change is thought to be caused by apoptosis because of the positive reaction with TdT-mediated dUTP-biotin nick-end labeling (TUNEL) method. Our results suggest that intracarotid infusion of etoposide can increase drug delivery of concurrent antitumor agents into tumor tissue, but cerebral parenchymal cell damage is expected with a higher dosage of etoposide. Therefore, the dosage of etoposide for intracarotid infusion should be lower than 15 mg/kg in order to reduce neurotoxicity of both etoposide and concurrent anticancer drugs.

Animals↗
PubMed1999

Proliferative potential of malignant glioma cells before and after interstitial brachytherapy.

The viability of tumor cells in radionecrotic tissue after interstitial brachytherapy (BRTX) was evaluated using immunohistochemical markers of proliferative potential in primary and recurrent tumors. Tumor specimens from 30 patients with malignant gliomas (14 anaplastic astrocytomas, 16 glioblastomas) taken before and after BRTX were examined using MIB-1 monoclonal antibody. Histological examination of specimens obtained by craniotomy or stereotactic biopsy after BRTX revealed tumor recurrence in 18 patients and radionecrosis in 12 patients including two with pure radionecrosis and 10 with a mixture of both tumor and radionecrosis. The MIB-1 index of the tumors with radionecrosis was 7.6 +/- 5.5%, and that of the primary tumors was 17.0 +/- 11.2%, showing a significant difference (p < 0.05). There was no significant difference between the MIB-1 index of the primary tumors with local recurrence after BRTX and the primary tumors which underwent radionecrosis. Although morphologically viable tumor cells were found in the radionecrotic tissue, BRTX causes a reduction in the proliferative potential of these tumor cells.

Adult↗
PubMed1999

[A clinical analysis of patients with primary intracranial germinomas: the relationship between proliferative potential and recurrence].

We analyzed clinically 30 germinomas (22 pure germinomas and 8 germinomas with syncytiotrophoblastic giant cell (STGC) and also investigated the proliferative potential of 18 germinomas immunohistochemically using MIB-1 monoclonal antibody in formalin-fixed paraffin-embedded sections. The majority of patients responded favorably and completely to the treatment. Seven patients (four had germinomas with STGC and the other three had pure germinomas) suffered recurrence after a complete response to radiotherapy and/or chemotherapy. The patients with germinomas with STGC experienced recurrence significantly more often than those with pure germinomas (P < 0.01). Three of the patients died. The MIB-1 indexes of the germinomas ranged from 18% to 80%. The average MIB-1 index of pure germinomas is 58.5 +/- 17.3%, that of germinomas with STGC is 45.3 +/- 17.1%. There was no significant difference between the two groups. The MIB-1 indexes of 3 recurrent cases were 64.3%, 51.9%, and 20.8%, respectively. There were no significant differences in the MIB-1 indexes between nonrecurrent cases and recurrent ones.

Adolescent↗
PubMed1999

[Clinical results of supratentorial astrocytoma grade II].

At present, there is no consensus concerning the treatment of low-grade gliomas. The authors conducted a retrospective review of surgically treated, histologically verified cases of supratentorial astrocytomas of grade II to evaluate the results of current treatment methods. Thirty-seven patients, 23 males and 14 females, treated from April, 1977 through March, 1997 were analyzed. Median patient age was 36 years (range 2-69 years). All patients were diagnosed by surgical specimens. Thirty were fibrillary, and three were gemistocytic astrocytomas. There were 13 total resections, 7 subtotal resections, 10 partial resections. Of the remaining 7, diagnosis was obtained by stereotactic biopsy. Twenty patients were irradiated and two received chemotherapy. Follow-up information was obtained for 33 patients. The follow-up time ranged from 4 months to 246 months (mean, 9 years). Overall survival rates at 5 and 10 years for the entire treated group were 71% and 57% respectively. Total and subtotal resections were significantly associated with longer survival time, the 5- and 10-year survival rates were 93% and 67%, respectively. They were 40% and 40% in patients with partial resection or needle biopsy. Patients with gemistocytic astrocytoma had a poor prognosis with a median survival of 44.5 months. The influence of radiotherapy was not obvious: 92 and 69% of patients were alive at 5 and 10 years respectively without radiotherapy. The extent of surgery and histological type were by far the most important factors in predicting length of survival. The importance of an accurate histologic diagnosis and a gross total resection is emphasized.

Adolescent↗
PubMed1999

[Effects of deoxyspergualin on proliferative glomerulonephritis].

A clinical trial of the immunosuppressive drug, deoxyspergualin (DSG), was conducted in five patients with various forms of proliferative glomerulonephritis (GN), such as IgA nephropathy in 2 patients, purpura nephritis in 1, membranoproliferative GN(MPGN) in 1, and rapidly progressive GN (RPGN) in 1 patient, respectively. DSG was intravenously administered at a daily dose of 0.25 or 0.5 mg/kg for 4 weeks. A marked decrease in proteinuria (to less than 50% of baseline) was observed in four patients. The other patient showed 38% reduction of proteinuria. However, proteinuria exacerbated again after discontinuation of DSG in three patients during a four-week follow-up period. Marked decrease (3,000/microliter) in white blood cell (WBC) counts was observed in three patients during the course of DSG treatment. We concluded that DSG therapy is beneficial in reducing proteinuria in patients with various forms of proliferative GN. However, since proteinuria increased after the discontinuation of DSG and serious leukocytopenia was observed, indiscriminate use of DSG in proliferative GN should be discouraged.

Adult↗
PubMed1999

Pathogenic role of glomerulo-tubular junction stenosis in glomerulocystic disease.

Glomerulocystic disease is an uncommon cystic renal condition characterized by cystic dilatation forming a glomerular cyst. The pathogenesis of this familial disease is unknown. We performed a serial section study using a biopsy specimen of a 16-year old female patient with glomerular cystic disease who had a family history of end stage renal failure. A total of 14 different glomeruli were analyzed, four of which exhibited a cystic appearance. Five glomerulotubular junctions were observed by serial sections, two of which had a stenotic appearance where glomerular cystic changes and periglomerular fibrosis were observed concomitantly. There were no such cystic glomerular changes in the other three glomeruli with non-stenotic glomerulo-tubular junctions. These findings suggest that the glomerular cystic lesion develops as a consequence of glomerulo-tubular junctional stenosis probably caused by periglomerular fibrosis.

Adolescent↗
PubMed1999

Expression of cell cycle regulator p27Kip1 is correlated with survival of patients with astrocytoma.

p27Kip1 is a cyclin-dependent kinase inhibitor that negatively regulates cell proliferation by mediating cell cycle arrest in G1. This study was undertaken to assess the prognostic value of p27Kip1 for astrocytomas. Tissue samples from 130 astrocytomas (WHO grade 1, 5 cases; grade 2, 23 cases; grade 3, 64 cases; grade 4, 38 cases), including 92 primary and 38 recurrent tumors, were examined immunohistochemically for Ki-67 and p27Kip1 expression. Patient charts were reviewed for clinical presentation, and survival was followed. The p27Kip1 labeling index (LI) ranged from 2.3 to 98.4%, with a mean value of 47.5% (+/-23.4%). The p27Kip1 LI decreased with increasing tumor grade but did not correlate with other parameters. There was no correlation between Ki-67 LI and p27Kip1 LI. For patients with primary astrocytomas, the 50% survival times of those with low p27Kip1 LI (<50%) and those with high p27Kip1 LI (> or =50%) were 17.1 and 69.6 months, respectively. For patients with high-grade tumors, the 50% survival times were 13.1 months for those with low p27Kip1 LI and 33.7 months for those with high LI. On multivariate analysis, p27Kip1 was one of the most significant prognostic factors, indicating that low p27Kip1 LI was associated with poor prognosis (primary, risk ratio = 2.5, P = 0.0023; high-grade, risk ratio = 2.2; P = 0.0139). The expression of p27Kip1 was inversely related to tumor grade and positively related to favorable outcome of patients with astrocytoma, suggesting that p27Kip1 may be a candidate for prognostic factor for this tumor.

Adolescent↗
PubMed1999

[Analysis of spinal cord hemangioblastoma in von Hippel-Lindau disease].

Von Hippel-Lindau (VHL) disease is an autosomal dominant hereditary disorder showing various clinical features. We analyzed 6 patients with spinal cord hemangioblastoma associated with VHL disease in four families. All patients had cerebellar hemangioblastomas. Four cases carried retinal hemangioblastoma and 5 cases showed visceral lesions; renal cell carcinoma (2 cases), renal cyst (2 cases), pancreas cyst (2 cases) and paraovarian tumor. In four cases, spinal cord hemangioblastomas were multiple. Ten symptomatic or rapidly growing lesions in 5 patients were surgically resected. Two of these lesions were extramedullary spinal root hemangioblastoma. Operative results were good except for a case of ventrally placed thoracic spinal intramedullary hemangioblastoma who showed paraparesis postoperatively. One patient who suffered from complete paraplegia preoperatively did not recover after surgery. In two patients, renal cell carcinoma was detected and nephrectomy was undergone. It was noteworthy that metastasis of renal cell carcinoma to the hemangioblastoma was histologically proved with anti-cytokeratin immunostaining in two patients with VHL-associated renal cell carcinoma. Molecular genetic analysis showed a missence mutation in one family and possible intragenic deletion in another family. However, two families showed no VHL gene mutation with single strand conformational polymorphism or Southern blot analyses. Spinal cord hemangioblastomas in VHL disease are often multiple and located at various sites and seem to be underestimated. Surveillance should start in childhood and requires annual follow-up with imaging of the central nervous system and abdominal viscera. Presymptomatic diagnosis by gene analysis can be very useful for early detection of this disease.

Adolescent↗
PubMed1999

[Combination effect of hyperthermia and MX2 on cultured glioma cell lines].

MX2, a new lipophilic morpholino anthracycline, has been reported to have chemotherapeutic effects superior to those of adriamycin against murine and human glioma cells in vitro and in vivo. To assess the combination effect of MX2 and hyperthermia in vitro, the thermo-chemosensitivities of cultured human (U251MG and KC) and rat (C6 and 9L) glioma cell lines were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. The number of viable cells in each cell line was markedly and dose-dependently decreased by MX2 treatment, but the sensitivity of U251MG to MX2 was less than that of the other cell lines. The survival of each cell line was decreased with the hyperthermic treatment at 43 degrees C for 60 minutes. Combined treatment with MX2 and hyperthermia had an additive effect on cultured glioma cells when MX2 was added to the medium at a dose below 50 ng/ml. However, combined treatment indicated neither an additive nor a synergistic effect when the dose of MX2 was above 50 ng/ml. We conclude that MX2 may be clinically useful against malignant gliomas when administered alone or in combination with hyperthermia.

Animals↗
PubMed1999

[Tissue penetration properties of macrolide antibiotics--comparative tissue distribution of erythromycin-stearate, clarithromycin, roxithromycin and azithromycin in rats].

The ability of antibiotics to penetrate the target organs is an important factor for the clinical effects and side effects in the treatment of infection. In the present study, the comparative tissue distribution of 4 kinds of macrolide antibiotics was determined in rats. After oral administration of 20 mg/kg, roxithromycin (RXM) had the highest plasma concentration, and clarithromycin (CAM) has the second highest. The Cmax of RXM and CAM were 2.7 and 1.0 micrograms/ml, respectively. On the other hand, both levels of erythromycin-stearate (EM-S) and azithromycin (AZM) were extremely low, with a Cmax of 0.1 microgram/ml. Concentration of the 4 compounds were measurable in the liver, kidney, spleen, lung and heart. The concentration in all tissues for each compound were significantly higher than those in the plasma. AZM had the most sustained and the highest tissue levels. The distribution patterns of RXM and AZM were almost similar to the case of EM-S, in that the highest tissue concentration was observed in the liver, followed in descending order by concentration in the kidney, spleen, lung and heart. On the other hand, CAM had the highest concentration in the lung, and was moderated in the liver. Major clinical indications are infections of the respiratory tracts, and commonly reported side-effects are hepatotoxity. Therefore, it is worth noting that the lung levels of CAM were significantly higher than in the liver, as the separation of clinical effects and side-effects.

Animals↗
PubMed1999

[Subcutaneous phaeohyphomycosis of the right thumb].

Black fungi are a group of fungi that are characterized by the development of a pale brown to black color in the cell walls of their vegetative cells, conidia, or both. A mycotic infection caused by a member of black fungi can be subdivided into three clinical entities: phaeohyphomycosis, chromoblastomycosis, and mycetoma. Phaeohyphomycosis is distinguished from mycetoma by the absence of grain (organized, interwoven mycelial aggregates) formation, and from chromoblastomycosis by the absence of sclerotic bodies (thick-walled muriform cells). Phaeohyphomycosis is a rare disease and has been sporadically reported. In the present report, phaeohyphomycosis of the right thumb of a 72-year-old man was presented. A precipitating trauma of two months earlier at the site was recalled. A solitary mass, 10 mm in diameter, was gradually formed in the palm side of the distal right thumb and finally resected. Histological examination disclosed a solitary granulomatous lesion surrounded by an incomplete fibrous capsule. The lesion mainly involved subcutaneous tissue and was composed of multiple pyogranulomas. Pigmented branched septate hyphae and yeast-like cells were sparsely found in the periphery of the abscess and within histiocytic cells of the granulomas. No sclerotic cells were detected. When pigmentation of black fungi in tissue is as faint as in the present case, Fontana-Masson staining is useful to accentuate the presence of melanin-like pigment of fungal cell walls.

Aged↗
PubMed1999

Relation between interleukin-1beta messenger RNA in gastric fundic mucosa and gastric juice pH in patients infected with Helicobacter pylori.

The effects of Helicobacter pylori infection on gastric acid secretion has not been clarified. The aim of this study was to elucidate the effects of H. pylori infection on gastric juice pH in relation to gene expression of interleukin-1beta (IL-1beta), which is reported to inhibit gastric acid secretion. Gastric juice pH and serum gastrin levels were measured in patients with peptic ulcer disease. The amount of IL-1beta mRNA in gastric fundic gland mucosa was also measured by a competitive reverse transcription-polymerase chain reaction method. These parameters were determined before and after treatment with lansoprazole and amoxicillin. Before treatment a significant positive relation was observed between the amount of IL-1beta mRNA in gastric fundic gland mucosa and gastric juice pH. After treatment significant decreases in the amount of IL-1beta mRNA, gastric juice pH, and serum gastrin levels were observed in patients with eradication of H. pylori, whereas no significant changes were observed in patients without eradication. These results suggest that H. pylori infection induces IL-1beta and suppresses acid secretion, resulting in increases in gastric juice pH and serum gastrin levels. Eradication of H. pylori decreases IL-1beta induction, resulting in an increase in gastric juice acidity and normalization of serum gastrin levels.

Base Sequence↗
PubMed1998

Effect of genetic differences in omeprazole metabolism on cure rates for Helicobacter pylori infection and peptic ulcer.

BACKGROUND: Omeprazole is metabolized by S-mephenytoin 4'-hydroxylase (CYP2C19) in the liver. In persons with a poor-metabolizer genotype for CYP2C19, the therapeutic efficacy of omeprazole may be increased. OBJECTIVE: To investigate whether CYP2C19 genotype status is associated with cure rates for Helicobacterpylori infection and peptic ulcer achieved by using dual therapy with omeprazole and amoxicillin. DESIGN: Prospective cohort study. SETTING: University hospital and health service center in Hamamatsu, Japan. PATIENTS: 62 patients with peptic ulcer and H. pylori infection. INTERVENTION: Omeprazole and amoxicillin. MEASUREMENTS: CYP2C19 genotype status and cure rates for H. pylori infection and peptic ulcer. RESULTS: Cure rates for H. pylori infection were 28.6% (95% CI, 13.1% to 48.7%), 60% (CI, 38.6% to 83.0%), and 100% (CI, 66.4% to 100%) in the rapid-, intermediate-, and poor-metabolizer groups, respectively. Healing rates for both duodenal and gastric ulcer in the three groups were roughly parallel with cure rates for H. pylori infection. CONCLUSION: The results of the genotyping test for CYP2C19 seem to predict cure of H. pylori infection and peptic ulcer in patients who receive dual therapy with omeprazole and amoxicillin.

Adult↗
PubMed1998

Magnitude and time course of microvascular obstruction and tissue injury after acute myocardial infarction.

BACKGROUND: Microvascular obstruction within an area of myocardial infarction indicates worse functional recovery and a higher risk of postinfarction complications. After prolonged coronary occlusion, contrast-enhanced MRI identifies myocardial infarction as a hyperenhanced region containing a hypoenhanced core. Because the time course of microvascular obstruction after infarction/reperfusion is unknown, we examined whether microvascular obstruction reaches its full extent shortly after reperfusion or shows significant progression over the following 2 days. METHODS AND RESULTS: Seven dogs underwent 90-minute balloon occlusion of the left anterior descending coronary artery (LAD) followed by reflow. Gadolinium-DTPA-enhanced MRI performed at 2, 6, and 48 hours after reperfusion was compared with radioactive microsphere blood flow (MBF) measurements and myocardial staining to define microvascular obstruction (thioflavin S) and infarct size (triphenyltetrazolium chloride, TTC). The MRI hypoenhanced region increased 3-fold during 48 hours after reperfusion (3.2+/-1.8%, 6.7+/-4.4%, and 9.9+/-3.2% of left ventricular mass at 2, 6, and 48 hours, respectively, P<0.03) and correlated well with microvascular obstruction (MBF <50% of remote region, r=0.99 and thioflavin S, r=0.93). MRI hyperenhancement also increased (21.7+/-4.0%, 24.3+/-4.6%, and 28.8+/-5.1% at 2, 6, and 48 hours, P<0.006) and correlated well with infarct size by TTC (r=0.92). The microvascular obstruction/infarct size ratio increased from 13.0+/-4.8% to 22.6+/-8.9% and to 30.4+/-4.2% over 48 hours (P=0.024). CONCLUSION: The extent of microvascular obstruction and the infarct size increase significantly over the first 48 hours after myocardial infarction. These results are consistent with progressive microvascular and myocardial injury well beyond coronary occlusion and reflow.

Analysis of Variance↗
PubMed1998

Simultaneous determination of tetrahydrocortisol and tetrahydrocortisone in human plasma and urine by stable isotope dilution mass spectrometry.

A capillary gas chromatographic-mass spectrometric method for the simultaneous determination of tetrahydrocortisol (THF, 3alpha,11beta,17alpha,21-tetrahydroxy-5beta-preg nane-20-one), allo-tetrahydrocortisol (allo-THF, 3alpha,11beta,17alpha,21-tetrahydroxy-5alpha-pre gnane-20-one) and tetrahydrocortisone (THE, 3alpha,17alpha,21-trihydroxy-5beta-pregnane-11,20-dion e) in human plasma and urine is described. [1,2,3,4,5-2H5]THF (THF-d5), allo-[1,2,3,4,5-2H5]THF (allo-THF-d5) and [1,2,3,4,5-2H5]THE (THE-d5) were used as internal standards. A double derivatization (bismethylenedioxypentafluoropropionate, BMD-PFP) made possible the separation of the three tetrahydrocorticoids with good gas chromatographic behavior. Quantitation was carried out by selected-ion monitoring of the characteristic fragment ions ([M-30]+) of the BMD-PFP derivatives of THF, allo-THF and THE. The sensitivity, specificity, precision and accuracy of the method were demonstrated to be satisfactory for measuring low concentrations of THF, allo-THF and THE in human plasma and urine.

Deuterium↗
PubMed1998

Primary brain tumors in children under age 3 years.

During the period from 1966 to 1996 the authors analyzed the clinicopathological characteristics of 46 cases of histologically verified primary brain tumors with symptomatic onset during the first 3 years of life. The patient group included 27 males and 19 females. There were 14 patients during the first year, 13 during the second year, and 19 during the third year. Supratentorial tumors (60.9%) were more common than infratentorial tumors. Histologically, neuroepithelial tumors predominated. The incidence of ependymal tumors, particularly malignant ones, and of neuronal/mixed neuronal-glial tumors was higher than in previous reports. Congenital brain tumors, those occurring within 2 months after birth, or tumors of dysplastic origin comprised 42.9% of the tumors that developed within 1 year of birth. At the onset, macrocephaly, failure to thrive, and seizures were prominent symptoms or signs in the younger patients. Focal neurological deficits and increased intracranial pressure predominated in the older patients. All but one patient underwent surgical treatment, and 17 patients received adjuvant therapy after surgery. The prognosis was mainly related to the histology of the malignancy. The outcome of medulloblastomas was poor. The quality of life of surviving patients was relatively good, 77.8% having better performance status (PS) than the Eastern Cooperative Oncology Group PS 2.

Brain Neoplasms↗