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Biomedical subjects

T Oda

Publications and source records attributed to T Oda.

At least 163 records · Page 9Linked to original sources
PubMed1998

Relationship between peritoneal washing cytology through implantable port system (IPS-cytology) and second-look laparotomy in ovarian cancer patients with unmeasurable residual diseases.

OBJECTIVE: Intraperitoneal chemotherapy for minimal residual ovarian cancer has been shown to be effective. However, evaluation of the response without a second-look laparotomy (SLL) is impossible because such disease is unmeasurable by radiographic studies. In this prospective pilot study, we evaluated the relationship between implantable port system (IPS)-cytology and findings by SLL in patients with unmeasurable diseases. METHODS: Patients eligible for this study were those who had either unmeasurable residual disease at the time of initial surgery or measurable residual disease which became unmeasurable before second-look laparotomy. At the time of the initial surgery, the IPS was placed and intraperitoneal chemotherapy was administered. To obtain IPS-cytology, approximately 500 ml of saline was infused, with the patients changing their position to wash the peritoneal surface as thoroughly as possible. More than 20 ml of saline was recovered for cytological evaluation. SLL was performed after 4 to 10 courses of chemotherapy. Results of IPS-cytology obtained immediately before SLL and the SLL findings were compared. RESULTS: Forty-four patients were entered into this study. Twenty-nine patients had unmeasurable residual disease at the time of initial surgery and 15 had measurable residual disease which became unmeasurable before SLL. Only 40 patients were eligible for evaluation because catheter failure occurred in 4 patients. Three of the 26 patients who had negative IPS-cytology results were found to have positive SLL results. All 14 patients who had positive IPS-cytology results also had positive SLL results. CONCLUSIONS: IPS-cytology can detect intraperitoneal persistent disease in patients with unmeasurable residual ovarian cancer. Persistent positive IPS-cytology can indicate a negative response to chemotherapy, thus making it possible to avoid SLL. Further study with a larger number of patients is required to determine the role of negative IPS-cytology.

Adult↗
PubMed1998

Dynamic changes in intracapillary hemoglobin oxygenation in human skin following various temperature changes.

To evaluate microvascular regulation in human skin, changes in intracapillary hemoglobin oxygen saturation (HbO2) were studied in human finger skin following an abrupt change in local ambient temperature. In the first series of experiments, we assessed the heterogeneity of HbO2 in the skin by using a 2-D scanning system and a rapid micro-lightguide spectrophotometer at each of two near-normal skin temperatures. The data showed that heterogeneous oxygenation exists in human skin even at near-normal temperatures (although the pattern is different at different skin temperatures). In a second series of experiments, the performance of the microcirculation of the skin was continuously examined in a selected area with initially different oxygenation levels during an abrupt change in local ambient temperature (5, 15, 25, 35, and 45 degrees C). At very low (5 degrees C) or very high (45 degrees C) temperatures, oxygenation in tissues within the low HbO2 area increased greatly, but there was no such change within the high HbO2 area. Our data indicate that different types of capillary supply units exist in human skin (indicated by the initially different oxygenation levels). These different capillary supply units may operate to produce a local redistribution of flow between the various capillary supply units. This effect may be initiated by heat sensors and oxygen sensors when temperature of the skin is varied.

Adult↗
PubMed1998

[Two cases of minimally invasive reoperative coronary artery bypass].

Reoperative coronary artery bypass grafting (CABG) are still associated with higher mortality than primary CABG. This is due in part to the potential for cardiac and patent graft injury during their dissection and the reopening of the sternum. Therefore, in two patients with recurrent angina attributable to occlusion of the old vein graft to the LAD, we performed reoperative CABG by the minimally invasive direct coronary artery bypass (MIDCAB) procedures. The left internal thoracic artery was anastomosed to the LAD through small anterolateral thoracotomy without cardiopulmonary bypass. Both patients recovered fast and underwent postoperative angiogram, showing the new grafts widely patent. About two weeks later, both discharged in the conditions of nearly normal activities. The reoperative MIDCAB grafting might be expected to be as safe and promising as the primary one.

Aged↗
PubMed1998

Discrepancy between tau immunoreactivity and argyrophilia by the Bodian method in neocortical neurons of corticobasal degeneration.

To clarify different features of cytoskeletal pathology in neocortical neurons between corticobasal degeneration (CBD) and Alzheimer's disease (AD), the relationship between neurofibrillary tangles (NFTs), which are defined as a fibrillary structure stained by the Bodian method, and tau-immunopositive neurons in layers II-III of the premotor cortex was assessed by sequential staining for tau immunohistochemistry followed by the Bodian method on the same section. In AD brains, tau-like immunoreactivity in neurons was uniformly colocalized with Bodian-positive NFTs. In CBD brains, however, tau-immunopositive neurons could be classified into three different types: (1) those not stained at all by the Bodian method (diffuse cytoplasmic type), which represented the majority of these immunopositive neurons, (2) some partly stained by the Bodian method (mixed type), and (3) a few for which argyrophilia demonstrated by the Bodian method was completely colocalized with immunoreactivity (NFT type). This discrepancy between tau-like immunoreactivity and Bodian method is characteristic of CBD and suggests that the tau molecule is less liable to form argyrophilic fibrils in neocortical neurons of CBD.

Aged↗
PubMed1998

Ruptured distal anterior choroidal artery aneurysm presenting with casting intraventricular haemorrhage.

This report describes a rare case of a distal anterior choroidal artery aneurysm which developed intraventricular haemorrhage without subarachnoid haemorrhage as shown on computerized tomographic (CT) scan. A 69-year-old hypertensive man suddenly became unconscious. An emergency CT scan showed a severe intraventricular haemorrhage and a small round low-dense lesion within the haematoma at the right trigone. The haematoma with obstructive hydrocephalus made the lateral ventricles larger on the right than on the left. CT scan could not detect any subarachnoid haemorrhage. Right interal carotid angiography revealed a saccular aneurysm at the plexal point of the right anterior choroidal artery. We approached the aneurysm and the small round lesion through the trigone via a right temporo-occipital corticotomy. We could clip the aneurysmal neck and remove the intraventricular haematoma and the papillary cystic mass (corresponding to the small round lesion on CT scan) totally in one sitting. Histological examination revealed the aneurysm to be a true one and the papillary cystic mass to be a choroid plexus cyst.

Aged↗
PubMed1998

Effect of the length and effective diameter of F-actin on the filament orientation in liquid crystalline sols measured by x-ray fiber diffraction.

We examined factors that affect the filament orientation in F-actin sols to prepare highly well-oriented liquid crystalline sols suitable for x-ray fiber diffraction structure analysis. Filamentous particles such as F-actin spontaneously align with one another when concentrated above a certain threshold concentration. This alignment is attributed to the excluded volume effect of the particles. In trying to improve the orientation of F-actin sols, we focused on the excluded volume to see how it affects the alignment. The achievable orientation was sensitive to the ionic strength of the solvent; the filaments were better oriented at lower ionic strengths, where the effective diameter of the filament is relatively large. Sols of longer filaments were better oriented than those of shorter filaments at the same concentration, but the best achievable orientation was limited, probably because of the filament flexibility. The best strategy for making well-oriented F-actin sols is therefore to concentrate F-actin filaments of relatively short length (<1 micrometer) by slow centrifugation in a low-ionic-strength solvent (<30 mM).

Actins↗
PubMed1998

Cell-to-cell interaction is required to induce proteinuria in in situ immune complex glomerulonephritis.

This experiment was performed to study the roles of intercellular adhesion molecule-1 (ICAM-1), lymphocyte function-associated antigen-1 (LFA-1), and another adhesion molecule, selectin, in the development of cationized antigen-induced in situ immune complex glomerulonephritis (CAICGN). CAICGN was induced in preimmunized rats by perfusing cationized human immunoglobulin G (CaIgG) through the left kidney. Albuminuria developed within 2 days of CaIgG perfusion and peaked around day 7. Marked polymorphonuclear leukocyte (PMN) infiltration was observed in the glomeruli 1 hour after CaIgG perfusion, but the infiltrate resolved by day 7. Immunofluorescent studies disclosed linear deposition of rat IgG and C3 along glomerular capillary walls 1 hour after CaIgG perfusion. Treatment with monoclonal antibodies (mAbs) to both ICAM-1 and LFA-1, as well as with a sulfatide, a ligand of L- and P-selectin, started within 2 days after CaIgG perfusion completely suppressed the development of proteinuria without affecting the glomerular deposition of immunoreactants. Although sulfatide attenuated the PMN response 1 hour after CaIgG perfusion, ICAM-1 and LFA-1 mAb treatment did not alter PMN infiltration. Treatment with ICAM-1 and LFA-1 mAbs started on day 5, or treatment with sulfatide started on day 4, after CaIgG perfusion did not affect albuminuria. These findings suggest that adhesion molecules play an important role in the development of proteinuria in CAICGN. The contribution of these molecules was evident for only a short interval after the induction of nephritis, when a significant infiltration of PMNs was observed.

Albuminuria↗
PubMed1998

SCA6 mutation analysis in a large cohort of the Japanese patients with late-onset pure cerebellar ataxia.

Spinocerebellar ataxia type 6 (SCA6) is caused by small CAG repeat expansion in the gene encoding the alpha1A-voltage-dependent-calcium channel subunit (CACNLIA4) on chromosome 19p13, and is a subgroup of the late-onset pure cerebellar ataxia (ADCA III). To investigate the prevalence of SCA6 in the Japanese, we analyzed this mutation in 23 families and 12 probands with ADCA III. The specificity and stability of the CAG repeat were examined in additional individuals and families with other miscellaneous dominant SCAs. The CAG expansion of SCA6 gene was exclusively observed in 12 of 23 families (52%) and 12 proband cases with ADCA III, but not in others. The CAG repeat was 21-33 in the disease-associated alleles (n=56), and 4-18 in normal alleles (n=1148). Expanded alleles were stable during transmission, and a significant inverse correlation for CAG repeat number with age at onset was noted. Our results indicate that SCA6 shares approximately half of the ADCA III in the Japanese, and that gene mutations causing the remaining, have yet to be identified.

Adult↗
PubMed1998

Co-injection of beta-amyloid with ibotenic acid induces synergistic loss of rat hippocampal neurons.

Senile plaques are a pathological hallmark of Alzheimer's disease. The major component of senile plaques is beta-amyloid which consists of approximately 4000 mol. wt of peptide. Accumulating evidence suggests that beta-amyloid may represent the underlying cause of Alzheimer's disease. In vitro, beta-amyloid has been shown either to be directly neurotoxic or to potentiate neurotoxic effects of excitatory amino acids. However, beta-amyloid toxicity in vivo has not always been reproducible. In this study, we injected beta-amyloid fragment 1-40 or 25-35 alone or in combination with a small amount of ibotenic acid, an excitatory amino acid, into rat hippocampus, and examined the histological and immunohistochemical changes two weeks after injection. Although beta-amyloid alone or ibotenic acid alone exerted only minimal degenerating effects on neurons just around the injection site, the co-injection of beta-amyloid 1-40 or beta-amyloid 25-35 with ibotenic acid produced drastic neuronal loss; the haematoxylin-eosin staining revealed that most neurons not only around the injection site but also in distant areas including CA1, CA4 and dentate gyrus were depleted. The neuronal loss occurred in a dose-dependent manner with respect to ibotenic acid. Immunohistochemical analysis showed that beta-amyloid with ibotenic acid induced great depletion of microtubule-associated protein-2 immunoreactivity and infiltration of astrocytes and microglia on neuronal loss. In addition, some apoptotic neuronal death indicated by DNA fragmentation and nucleic condensation was observed. Beta-amyloid depositions detected by two different types of anti-human beta-amyloid antibodies were limited to the injection site. Dizocilpine maleate (MK-801), an antagonist for an excitatory amino acid receptor, completely inhibited the neuronal death in rat hippocampus. These results suggest that the co-injection of beta-amyloid with a small amount of ibotenic acid provides a useful model for investigation of the pathogenetic mechanisms leading to Alzheimer's disease.

Amyloid beta-Peptides↗
PubMed1998

Expression and distribution of brain natriuretic peptide in human right atria.

OBJECTIVES: We investigated expression of brain natriuretic peptide (BNP) as well as atrial natriuretic peptide (ANP) and their genes in human right atria. Their relations with atrial pressure were also examined. BACKGROUND: The BNP plays a roll in electrolyte-fluid homeostasis such as ANP. The tissue level is reported to be elevated in the failing ventricles. However, expression and transmural distribution of BNP in the atria remain unclear. METHODS: Expression of ANP and BNP was immunohistochemically investigated in the right atrial (RA) specimens from 21 patients who had undergone cardiac surgery. The mRNA of specimens were quantitatively measured by Northern blot analysis and also evaluated by in situ hybridization. In addition, plasma levels of ANP and BNP were measured in the patients. RESULTS: The BNP immunoreactivity was diffusely seen in RA tissue of patients with mean RA pressure (mRAP) of 5 mm Hg or more, but it was noted only in the subendocardial half of the atria of those with mRAP less than 5 mm Hg. There was a significant correlation between the incidence of BNP-positive myocytes and mRAP (r = 0.850, p < 0.0001). Conversely, ANP-positive myocytes were found diffusely in all cases. In Northern blot analysis, the mRNAs levels of ANP and BNP in the atrial tissue were positively correlated with the mRAP (ANP, p = 0.775, p < 0.005 and BNP, p = 0.771, p < 0.005). In situ hybridization confirmed these findings. The mRNA levels were significantly correlated to each other (r = 0.845, p < 0.0002). Plasma ANP and BNP levels were elevated in the patients compared with that in controls; however, none were significantly correlated with the mRAP. CONCLUSIONS: Expression of BNP and BNP mRNA is augmented in the atria with increased pressure, and distributed predominantly in the subendocardial side. The level of BNP mRNA was well correlated with that of ANP mRNA. Thus, these two genes might be commonly regulated in response to atrial pressure.

Aged↗
PubMed1998

Segmental mandibular reconstruction by distraction osteogenesis under skin flaps.

In five adult dogs, molars were extracted and skin flaps from the neck prepared for delayed transplantation. Two weeks later, a 25-mm segment of the mandible was excised with surrounding periosteum and gingiva. The mandible was stabilized with a reconstruction plate and the intraoral defect repaired with a pedicled skin flap. A proximal transport segment was created and an external distraction device was applied. After one week, distraction of the transport segment was begun at a rate of 1 mm/day. After distraction was completed, the lengthening appliance was left in place for 12 weeks until the dogs were killed. Radiologic and histologic examination revealed new bone at the distraction site. The intraoral skin flap was pushed out of the defect as distraction progressed. Bony union of the transport segment to the distal stump was not achieved due to intervening soft tissue. These results suggest that it is feasible to bridge a mandibular defect that is covered with a skin flap, with distraction osteogenesis.

Animals↗
PubMed1998

Targeted cancer chemotherapy for VX2 tumour implanted in the colon with lipiodol as a carrier.

In this study, we examined the possibility of targeting drug delivery to tumours by dissolving the cytotoxic drug in a lipid fluid that is selectively deposited in tumours. Rabbits bearing VX2 tumour 10-20 mm in diameter in the large bowel received arterial injections of 0.2 ml of mitomycin C (MMC) dissolved in Lipiodol (MMC/Lipiodol), and the antitumour activity and adverse effects were examined. One week after treatment complete necrosis of the tumour was observed in 8 of 10 rabbits that received MMC/Lipiodol (3 mg/ml) without severe adverse effects on the surrounding caecum. In comparison 3/12 control animals that received MMC in saline and Lipiodol also showed complete necrosis. 6 of 7 rabbits killed eight weeks after the injection of MMC/Lipiodol were cured, with no viable tumour cells and with a normal appearance of the surrounding large bowel. In conclusion, MMC dissolved in Lipiodol may be adaptable for the treatment of colon cancer and may achieve antitumour activity without severe adverse effects.

Animals↗
PubMed1998

The effects of gonadotropin-releasing hormone agonist on androstenedione production and follicular development during controlled ovarian hyperstimulation.

PURPOSE: We performed a prospective randomized study to assess the effects of a GnRH agonist (GnRH-a) on follicular development and steroidogenesis during controlled ovarian hyperstimulation (COH). METHODS: Patients undergoing in vitro fertilization (IVF) for tubal infertility received human menopausal gonadotropin (hMG) stimulation with or without the GnRH-a, buserelin, beginning in the midluteal phase of the prior cycle. We analyzed serum hormone levels, follicular development, and outcome of IVF. RESULTS: The mean number of retrieved oocytes was significantly greater, and the implantation rate per embryo was significantly higher, in the GnRH-a/hMG group (n = 101) than in the hMG-only group (n = 97). The concentration of androstenedione (A) and the A/estradiol ratio in the serum were significantly lower in the GnRH-a treatment group throughout the follicular phase. CONCLUSIONS: The concomitant use of GnRH-a during COH prevents atretic change of the follicles and enhances follicular development by reducing androgen accumulation, resulting in a higher developmental competence of the oocytes.

Adult↗
PubMed1998

Extracellular poly(alpha-L-guluronate)lyase from Corynebacterium sp.: purification, characteristics, and conformational properties.

Extracellular alginate lyase was purified from the culture supernatant of Corynebacterium sp. isolated from the sewage of a sea tangle processing factory in order to elucidate the structure-function relationship of alginate lyase. The electrophoretically homogeneous enzyme was shown to have a molecular mass of 27 kDa by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) and by gel filtration, with an isoelectric point of 7.3. The molecular mass from amino acid analysis was 28.644 kDa. The optimal pH and temperature for the enzyme reaction were around 7.0 and 55 degrees C, respectively. Metal compounds such as MnCl2 and NiCl2 increased the enzyme activity. The enzyme was identified as the endolytic poly(alpha-L-guluronate)lyase, which was active on poly(alpha-L-1,4-guluronate) and caused a rapid decrease in the viscosity of alginate solution. Measurement of the far-UV circular dichroic spectrum of the enzyme molecule gave a spectrum with a deep trough at 215 nm accompanied by a shallow one at around 237 nm, and with a high peak at 197 nm and a much lower one at 230 nm. This spectrum was most likely to be that of the beta-form of the enzyme molecule and resembled poly(beta-D-mannuronate)lyase from Turbo cornutus (wreath shell) and poly(alpha-L-guluronate)lyase from Vibrio sp. (marine bacterium). The near-UV circular dichroic spectrum was characteristic for aromatic amino acid residues. In the presence of 6 M urea, these spectra changed drastically in the near-UV and a little in the far-UV with the disappearance of the enzyme activity. Removal of the denaturant in the enzyme solution by dialysis restored both the activity and inherent circular dichroic spectra. The beta-sheets observed in alginate lyases as the major ordered structure seem to be a common conformation for the lyases.

Amino Acids↗
PubMed1998

Selection system for genes encoding nuclear-targeted proteins.

Nuclear proteins have essential roles in cell proliferation and differentiation. We have developed a yeast selection system-the nuclear transportation trap (NTT)-to identify genes encoding nuclear transport signals. Both unknown and previously identified nuclear localization signals were identified from a human fetal brain cDNA library. The majority (75%) of the unknown proteins examined were exclusively localized to the nucleus in COS-7 cells. We propose that NTT is an efficient method for isolating cDNAs that encode nuclear targeted proteins that can be applied to the retrieval of novel nuclear proteins and to annotate gene function.

Amino Acid Sequence↗
PubMed1998

Clinicopathological significance of intratubular giant macrophages in progressive glomerulonephritis.

Very large macrophages, which we have termed "giant macrophages" (G-M phi), have been found in renal tubules, some containing cytoplasmic vacuoles. To elucidate their pathophysiological roles, we examined renal biopsy tissues from various primary glomerulonephritis (GN) and tubulointerstitial nephritis (TIN) using immunohistochemistry with monoclonal antibodies against M phi and other cell surface markers. Giant macrophages were absent or rare in TIN, minimal change nephrotic syndrome, and minor glomerular abnormalities, but G-M phi was plentiful in progressive glomerulonephrides such as IgA nephropathy with crescents, membranoproliferative GN, focal segmental glomerulosclerosis, and especially in crescentic GN. These G-M phi were usually seen in the lumen of renal tubules, but occasionally were found in the Bowman's spaces and glomerular tufts, and similar cells were also found in urine. Moreover, they frequently made contact with tubular epithelial cells expressing intercellular adhesion molecule-1, and the tubular epithelial cells in such lesions often had degenerative changes. Giant M phi may damage tubular epithelial cells from the luminal side. Phenotypically, G-M phi showed activated (CD71+) and mature (25F9+) characteristics along with features of M phi (CD68+), and the cytoplasm contained a great deal of lipids. The numbers of G-M phi in renal tissues closely correlated with the degree of hematuria (rho = 0.5, P < 0.001), serum creatinine value (r = 0.63, P < 0.001) in GN patients (N = 96) and with proteinuria in IgA nephropathy patients (r = 0.89, P < 0.001, N = 27). These data suggest that G-M phi are M phi that were activated and matured in certain active inflammatory sites, which flowed into tubules and then into urine. Thus, the existence of G-M phi in biopsy tissue or urine reflect the activity of GN and may have a predictive value for the progression of GN.

Antibodies, Monoclonal↗
PubMed1998

Nitric oxide-mediated modulation of interleukin-8 production by a human glioblastoma cell line, T98G, cocultured with myeloid and monocytic cell lines.

Coculture of T98G glioblastoma cells with the myeloid and monocytic cell lines, HL-60, and THP-1 produced minimal amounts of interleukin-8 (IL-8). Pretreatment of HL-60 or THP-1 cells with phorbol myristate acetate (PMA) enhanced their capacity to induce IL-8 production by T98G cells. In contrast, the murine macrophage cell lines J774 A.1 and RAW 264.7 induced high levels of IL-8 production by T98G cells without PMA activation. To determine the molecules responsible for the induction of IL-8 by T98G cells, we carried out coculture experiments with a membrane fraction prepared from RAW cells and indicated that membrane-associated and free forms of murine IL-1alpha acted on human T98G cells to produce IL-8. RAW cells were unique in that increasing the number of RAW cells relative to the number of T98G cells (RAW/T98G ratio > 4:1) significantly suppressed IL-8 production by T98G cells. Because RAW cells produce large amounts of nitric oxide (NO), we assumed that the suppression of IL-8 production was ascribable to the NO produced by the RAW cells. This was supported by the inverse relationship between increasing concentrations of NO and IL-8 production seen in this coculture system. The involvement of NO in the suppression of IL-8 production was confirmed by the finding that N-monomethyl-L-arginine (NMMA), which inhibits NO production, reversed this suppression, whereas S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a strong NO generator, suppressed IL-8 production. Our results indicate that high levels of NO suppress IL-8 production by T98G cells, and murine IL-1alpha plays a major role in the induction of IL-8 production by T98G cells. It is, therefore, possible that excessive production of NO during the interaction of glioma cells with macrophages may play a regulatory role in chemokine production, thus mitigating inflammatory responses.

Animals↗