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T Oda

Publications and source records attributed to T Oda.

1,150 records · Page 64Linked to original sources
PubMedDate not supplied

Quantitative assessment of human sperm acrosome reaction by using fluorescein isothiocyanate conjugated concanavalin A--comparison between highly purified acrosome reacted with non-acrosome reacted sperm.

In the present study, to achieve quantitative assessment of human sperm acrosome reaction by using fluorescein isothiocyanate conjugated Concanavalin A (FITC-Con A), the optimum conditions for microscopic observation were established by comparing the fluorescent images between the purified human sperm with the intact acrosome (non-acrosome reacted sperm; non-AR sperm) and those with exposed inner acrosomal membrane (acrosome reacted sperm; AR sperm). FITC-Con A stained not only the inner acrosomal membrane but also the other portions. These non-specific bindings were excluded by the competitive dissociation with alpha-D-mannose (Man) solution, the specific labeling of the inner acrosomal membrane with FITC-Con A was accomplished in the presence of 0.5 mg/mL Man. The influence of methanol fixation on the acrosome status were examined. The assessment of the acrosome reaction should evaluate whether the inner acrosomal membrane is exposed or masked by the plasma membrane, and methanol fixation is often employed in the histochemical stain. By methanol fixation, the fluorescent profiles of AR sperm were not altered before and after the treatment, bright fluorescence were found in the acrosomal regions. On the other hand, non-AR sperm gave weak fluorescence on the sperm heads before the treatment, the acrosomal regions fluoresced brightly after the treatment similar to those of AR sperm. Methanol fixation caused false positive results, it might denaturate the plasma membranes and facilitate permeability of FITC-Con A. FITC-Con A fluorescent stain and the modified triple stain (rose bengal stain) gave good positive correlation to evaluate AR sperm. This result concluded that the optimum conditions with FITC-Con A stain in the present procedure might be an useful tool for observation of human sperm acrosome reaction.

Acrosome↗
PubMedDate not supplied

Effects of ligustrazine on hepatic oxygenation in isolated perfused rat liver.

The effects of ligustrazine on hepatic oxygenation in the isolated rat liver were investigated during prolonged perfusion and following the injection of norepinephrine. After injection of erythrocytes into the perfusate, the hemoglobin spectra in the liver were measured by Erlangen microlightguide spectroscopy, and the hemoglobin oxygenation (HbO2) in the liver was calculated on the basis of the Kubelka-Munk theory. During artificial perfusion, the HbO2 value was decreased from 59.3 +/- 6.4% (after one hour's perfusion) to 25.5 +/- 19.5% (n = 441; after six hours' perfusion). However, when ligustrazine was injected into the perfusate after six hours' perfusion, the HbO2 values recovered to 56.4 +/- 9.7% (n = 441). After injection of norepinephrine, HbO2 in the liver decreased from 48.8 +/- 10.4% to 25.2 +/- 18.4% (n = 961), while subsequent administration of ligustrazine caused a recovery to 62.9 +/- 6.0% (n = 961). Our results suggested that ligustrazine is a powerful hepatic vasodilator for improving hepatic oxygenation.

Animals↗
PubMedDate not supplied

Experimental alveolar ridge augmentation by distraction osteogenesis using a simple device that permits secondary implant placement.

The purpose of this study was to develop an improved technique of alveolar ridge augmentation by distraction osteogenesis using distraction screws, and to investigate tissue reactions to titanium implants at the distraction site. The left mandibular premolars were extracted from 6 adult dogs. After 12 weeks, a box-shaped osteotomy of the alveolar bone was carried out, and distraction devices were placed on the transport and base segments. After a 7-day latency period, the alveolar bone was augmented by 7 mm vertically at a rate of 1.0 mm/day. Just after distraction, these devices were replaced with dental implants for fixation of the transport segment and bone formation of the distraction site. Histologic and radiographic evaluations were made at 8 and 12 weeks after distraction. Vertical augmentation averaged 6.1 mm after 12 weeks of consolidation. It was possible to lengthen the alveolar bone without great difficulty, and good bone formation was recognized in the distraction site. Greater integration between the implant and the distracted bone was observed at 12 weeks after distraction than at 8 weeks. Distraction osteogenesis was successfully applied to alveolar ridge augmentation by this improved technique, and the implants osseointegrated in the augmented ridge.

Alveolar Ridge Augmentation↗
PubMedDate not supplied

Mitral insufficiency in an incomplete form of Marfan syndrome corrected with valve replacement.

A 14-year-old boy with an incomplete form of the Marfan syndrome developed an acute episode of severe congestive heart failure following exertion. The preoperative studies indicated a mitral insufficiency, and a floppy, thickened mitral valve was removed and replaced with a Starr-Edwards prosthesis. Microscopically, the valve showed increase in collagen with central myxomatous transformation. Seven months postoperatively the patient is doing well and has no symptoms of heart failure.

Adolescent↗
PubMedDate not supplied

Extra-tumor perineural invasion predicts postoperative development of peritoneal dissemination in pancreatic ductal adenocarcinoma.

Peritoneal dissemination is one of the major patterns of postoperative recurrence and a major cause of death in pancreatic ductal adenocarcinoma. To predict the development of postoperative peritoneal dissemination (PPD), correlations between the occurrence of PPD and clinicopathological factors were analyzed in 23 patients with pancreatic ductal carcinoma who underwent tumor resection and were carefully monitored after the operation. Fifteen cases (65.2%) developed PPD, but the other 8 cases (34.8%) did not meet the criteria for a diagnosis of PPD. Location of the tumor in the pancreatic tail or body (p = 0.0041, HR = 10.827, 95% CI = 2.126-55.127) and the presence of extra-tumoral perineural invasion (ETNI) (p = 0.0490, HR = 0.114, 95% CI = 0.013-0.990) were found to have predictive value for the development of PPD. These results suggested that intensive therapy selectively focused on the peritoneum in cases with ETNI, might prevent the development of PPD and reduce the side effects of treatment in cases without ETNI.

Adult↗
PubMedDate not supplied

Utility of serum CA 19-9 monitoring in preoperative radiotherapy for pancreatic cancer.

BACKGROUND/AIMS: Pancreatic cancer is extremely refractory even to aggressive treatments including surgery, resulting in early metastasis and/or local recurrence. We investigated changes in serum tumor marker CA 19-9 levels during preoperative radiotherapy in conjunction with initial treatment failure. METHODOLOGY: Twenty-three patients presenting with localized disease and an increased serum CA 19-9 level, who were slated to undergo pancreatectomy and/or intraoperative radiotherapy following preoperative radiotherapy were reviewed. CA 19-9 response, the ratio of post-radiotherapy level before laparotomy to pre-radiotherapy level, was analyzed in relation to disease-control time and survival. RESULTS: Eleven patients revealed metastasis at restaging or laparotomy; 12 patients (52%) completed aggressive treatments. Initial failure was identified at the liver (52%), peritoneum (52%), or local site (26%) with a median disease-control time of 91 days; 7 patients showed combined failure. All but 1 patient died of cancer with a median survival time of 264 days. CA 19-9 response (range: 0-1185%) did not correlate with disease-control time or survival; 8 progressive-disease patients (> 140% response), however, showed significantly shorter disease-control time than 15 nonprogressive-disease patients (< or = 140% response). CONCLUSIONS: CA 19-9 monitoring is useful in preoperative radiotherapy for identifying patients who will not benefit by succeeding aggressive treatments by predicting early metastasis.

Adult↗
PubMedDate not supplied

Purification and biochemical characterization of squirrel monkey retrovirus-H produced in a human lymphoblastoid cell line.

We found a type D retrovirus in a human lymphoblastoid cell line of B-cell lineage. Molecular cloning and nucleotide sequencing of the provirus genome revealed that this virus was closely related to squirrel monkey retrovirus (SMRV), and we designated this virus as SMRV-H. To investigate the relationship between these retroviruses, SMRV-H was purified from the virus-producing cells, and its biochemical properties were characterized. The cell-adhesive virus particles were successfully separated from the cell by a brief trypsin treatment and purified by velocity sedimentation. The purification of the virus was confirmed by electron microscopy. Major gag protein of the virus is phosphorylated, and has a molecular weight of 34 kDa. The virion-associated reverse transcriptase prefers Mg2+ to Mn2+. These properties of SMRV-H were almost the same as those of SMRV.

Animals↗
PubMedDate not supplied

Cytotoxicity of smancs in comparison with other anticancer agents against various cells in culture.

The cytoxicity of neocarzinostatin (NCS) and smancs [copoly(styrene maleic acid)-conjugated NCS] to various cultured cells was compared with that of several other antitumor agens in clinical use on various malignant and non-malignant cells as regards to their effect on colony formation of cells. Both NCS and smancs showed the most potent cytotoxicity against all tumor cell lines tested; the IC50s (colony inhibitory concentration 50%) of these drugs were 3.2-20 nM, 10-1000 times lower than those of other drugs. In contrast, NCS and smancs exhibited relatively lower toxicity to normal cells such as human skin fibroblasts and chick embryonic fibroblasts (IC50, about 50 and 100 nM, respectively). Normal rat hepatocytes were found to be very resistant to NCS and smancs (both IC50s were about 500 nM). Moreover, the minimum exposure time of smancs to cultured tumor cells required to achieve effective cytotoxic activity was much shorter than that of NCS and other drugs. Namely, at 30 nM more than 80% cells were killed by exposure to smancs for only a few minutes, whereas with NCS more than 80 min of exposure time was required. It was also found that smancs inhibited the uptake of 3H-thymidine into DNA as expected. These results clearly indicate that smancs is an unique antitumor agent with a broad antitumor spectrum which exhibits some characteristics similar to, but also some very different from NCS.

Animals↗
PubMedDate not supplied

A case of aortic septal defect, associated with patent ductus arteriosus and aberrant right subclavian artery.

This report describes an operation, successfully performed by the authors, on an aorta septal defect (A-P Window) associated with patent ductus arteriosus (PDA) and aberrant right subclavian artery (ARSA). When an A-O Window is complicated by PDA and ARSA, preoperative diagnosis is often difficult. It is often mistaken for a large PDA and ARSA. Therefore at the time of operation of a large PDA and ARSA, it is necessary tao keep artificial heart-lung machine ready so that the A-P Window can be corrected at the same operation if necessary. In this case, the aortopulmonary communication was closed directly by transpulmonary approach under profound hypothermia with extracorporeal circulation after the division of ductus arteriosus and the dissection and mobilization of the stenotic esophagus from surrounding tissues of the ARSA. The division of the ARSA was not carried out, because patient was asymptomatic. The A-P Window associated with PDA and ARSA has apparently not been reported.

Ductus Arteriosus, Patent↗
PubMedDate not supplied

Intracavitary treatment of malignant ascitic carcinomatosis with oily anticancer agents in rats.

The anticancer effects and pharmacokinetics of intraperitoneal (ip) injection were determined for doxorubicin (DOX) dissolved in a lymphographic oily contrast medium, Lipiodol Ultrafluid (Lipiodol) (DOX/Lipiodol), using AH 130 ascitic tumor in rats. A high percentage (50%) of long-term survivors (cure) was observed with only a single ip injection of the DOX/Lipiodol on the seventh day after tumor inoculation, by which time the tumor ascites accumulated to a level similar to that seen clinically. The cure rate of this lipid formulation was much better than that for DOX dissolved in saline (DOX/saline) (17%). An immunopotentiating agent, Picibanil, given in 1 KE (clinical unit) or 5 KE doses was no better than the saline group, indicating that the above effect was not a result of immunopotentiation by Lipiodol. The severity of toxic side effects of DOX was also reduced by lipid solubilization. Pharmacokinetic study showed that DOX/saline was absorbed rapidly into the blood stream from the peritoneal cavity, whereas DOX/Lipiodol was retained in the ascites at a higher concentration for a much longer time. Thus the present results suggest that lipid formulations of anticancer agents have augmented therapeutic efficacy by intracavitary injection. The lipid formulations show increased stability in and prolonged slow release from the lipid milieu. Thus this therapeutic tactic of using oily anticancer agents appears to be promising for the control of pleural and peritoneal carcinomatoses.

Animals↗
PubMedDate not supplied

Formation of free radicals and active oxygen species from diethylstilbestrol and its derivatives.

Diethylstilbestrol (DES), an estrogen analogue, was converted into a free radical in alkaline dimethyl sulfoxide as well as in an H2O2/peroxidase system. The presence of the hydroxyl group of the DES molecule was essential to free radical formation. Indenestrol A (IA), a microsomal metabolite of DES, showed a paramagnetic property without enzymatic activation. The electron spin resonance spectrum of IA seemingly corresponded to that of the enzymatically formed DES radical. In an NADH/peroxidase system, DES induced concomitant production of active oxygen species, which were also produced by IA. Related compounds of IA were also examined to compare with DES and IA. The significance of the free radical is discussed in relation to the process of carcinogenesis by DES.

Dienestrol↗
PubMedDate not supplied

Relationship between multifunctional protein "clusterin" and Alzheimer disease.

In the Alzheimer disease (AD) brain, senile plaques contain several proteins and cytokines, such as beta-amyloid protein (A beta), interleukin 1, transforming growth factor beta 1 (TGF beta 1), and apolipoprotein E, which may contribute to the process of neurodegeneration. Clusterin is also known to colocalize with A beta deposits in neuritic plaques. Clusterin is a multifunctional protein that causes cell aggregation, binds to beta-endorphin, and inhibits the terminal complex formation of complement. Clusterin mRNA and protein are increased in the brains of AD patients. Cytokines such as TGF beta 1 and interleukin 1 enhance the expression of clusterin, which may link clusterin to inflammatory mechanisms in AD. A beta, a 39-43 amino acid peptide, is a major component of the senile plaques that are characteristic of AD. Highly aggregated A beta is implicated in neurodegeneration, e.g., A beta aggregates spontaneously into fibrillar forms resembling those in plaques that, in experimental models, cause neurotoxicity through oxidative stress. Clusterin inhibits the aggregation of A beta, which might be neuroprotective according to the aggregation-toxicity hypothesis of A beta. However, clusterin enhanced the oxidative stress of A beta. This may extend its neurotoxicity to locations distal from plaques wherever A beta is present.

Alzheimer Disease↗
PubMedDate not supplied

Formation of free radicals from steroid hormones: possible significance in environmental carcinogenesis.

In order to clarify the mechanism of environmental carcinogenesis, steroid hormones were checked for formation of free radicals and active oxygen species. In alkaline DMSO in vitro, glucocorticoids, progestines, androgens and estrogens exhibited distinct ESR signals with characteristic hyperfine structures. Accumulated data on a great number of steroid derivatives suggest that an unpaired electron is localized at position 20 in the case of glucocorticoids, whereas it is at position 3 in other steroid hormones. Since experimental conditions include oxygenation reactions and more or less reflect enzymatic reactivity, the results obtained suggest further study on the physiological formation of free radicals from steroid hormone is warranted. Although detection of the free radicals of steroid hormones in several enzyme systems was limited to estrogens, evidence suggests that glucocorticoids as well as androgens may also share the physiological formation of free radicals. The production of active oxygen species was confirmed in certain cases.

Animals↗
PubMedDate not supplied

Evaluation of indicators of tissue hypoxia during progressive hemorrhage and blood retransfusion.

To establish whether the indicators of oxygen metabolism reflects the improvement in tissue oxygenation during therapy, twelve rabbits subjected to progressive hemorrhage followed by retransfusion were studied. The changes in oxygen delivery (DO2), oxygen consumption (QO2), oxygen extraction ratio (O2ER), arterial lactate concentration, venous-arterial difference in PcO2 (v-aDPcO2) and arterio-venous difference in pH (a-vDpH) were analyzed during two phases (above and below) the critical DO2 with the regression coefficient (slope). The main findings during the transfusion were: a) the slope, when compared during the two phases was not significantly different for O2ER, v-aDPcO2 or a-vDpH, while during hemorrhage each variable showed a significantly different slope, b) in the phase below the critical DO2, the slope was significantly less steep than that during hemorrhage for lactate and v-aDPcO2, c) in the phase above the critical DO2, lactate alone had significantly steeper slope than that during hemorrhage. In conclusion, it is suggested that the changes in QO2 best reflect the recovery from tissue hypoxia.

Animals↗
PubMedDate not supplied

Targeted vinblastine chemotherapy with two preparations of lipiodol contrast medium.

BACKGROUND: Long-term survival and cure can not be achieved in patients with unresectable metastatic liver cancer. In this study, to improve the antitumor activity of oily anticancer agents, which enable targeted cancer chemotherapy, various concentrations of vinblastine dissolved in Lipiodol ultrafluid (vinblastine/Lipiodol U) or Lipiodol F, which has three times the viscosity of Lipiodol ultrafluid, were used. MATERIALS AND METHODS: Rabbits bearing VX2 tumors measuring 1 to 2 cm in diameter in the liver received arterial injections of 0.2 ml of these drugs, and antitumor activity were examined. RESULTS: Complete necrosis of the tumor was observed in three of nine rabbits received vinblastine/Lipiodol U at 2.5 mg/ml. Complete necrosis of the tumor was observed in all eleven rabbits which received vinblastine/Lipiodol U at 5 mg/ml. At concentrations of 7.5 and 10 mg/ml, the necrotic area spread from the tumor to the liver parenchyma surrounding the tumor. The antitumor activity of vinblastine dissolved in Lipiodol F was increased compared with that of vinblastine dissolved in Lipiodol ultrafluid. CONCLUSIONS: The antitumor activity of a kind of the oily anticancer agents, vinblastine/Lipiodol increased with increasing amounts of vinblastine dissolved in Lipiodol ultrafluid and with the increasing viscosity of the carrier, Lipiodol.

Animals↗