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Biomedical subjects

T Aoki

Publications and source records attributed to T Aoki.

At least 847 records · Page 47Linked to original sources
PubMed1991

[Cervical lung hernia in a case of severe chronic asthma and bronchitis].

A case of a bilateral pulmonary hernia of the lungs into the supraclavicular fossae is described. A man, aged 79, with severe chronic asthma and chronic bronchitis due to air pollution, complained of a cervical mass off and on for several years. The herniation was greater on the right side. It could be identified on physical examination by the presence of a soft painless supraclavicular bulge which was exaggerated by strain or cough. Radiologically this herniation could best be identified on lateral cervical roentgenogram. It is said that cervical lung hernia is a rare condition, but in our experience supraclavicular herniation of the lung is not unusual in cases of severe chronic obstructive lung disease.

Aged↗
PubMed1991

[Hepatic infusion-chemotherapy of liver metastases from stomach cancer--comparative study for intraarterial group and non-intraarterial group].

Metastasis to the liver was detected in 96 out of 1,825 patients with gastric cancer treated at our department from April 1980 to March 1990, and was respectively found to be synchronous and metachronous in 63 and 33 of the 96 patients. We compared survival durations among these 96 patients according to synchronous or metachronous metastasis by dividing them into the intermittent intra-arterial chemotherapy (FAM) group (18 patients) and non-intra-arterial chemotherapy group (78 patients). In the comparison between the intra-arterial and non-intra-arterial groups, the survival duration was determined to be significantly longer in the intra-arterial group by Wilcoxon generalized test and Cox-Mantel test (p less than 0.01). Among the patients with synchronous metastasis, a significantly longer survival duration was also observed in the intra-arterial group (p less than 0.01). The direct effect of intra-arterial chemotherapy through CT was seen in 56% of the patients in the intra-arterial group. These results indicated the usefulness of FAM hepatic infusion chemotherapy for the treatment of metastasis of gastric cancer to the liver. It is expected that therapeutic results will be much more improved by selecting more effective anticancer drugs in the future.

Aged↗
PubMed1991

[Study of intermittent intra-arterial infusion chemotherapy in liver metastases from squamous cell carcinoma].

There are few reports about the methods, amounts, and kinds of dosage about intermittent intra-arterial chemotherapy of liver metastases from primal pathological type's squamous cell carcinoma. Because they are less than liver metastases from adenocarcinoma of colon or stomach. Although it is important of other factors about the operative method of primary focus and metastases of the other parts, it is possible that those cases obtained the good prognosis and protected liver failure, if those liver metastases could be controlled well. In our department from January 1987 to December 1989, 9 cases of inoperative liver metastases of squamous cell carcinoma (esophagus: 4 cases, larynx: 3 cases and cervix of uterus 2 cases) were treated of intra-arterial infusion chemotherapy of FAM (5Fu 500 mg/week, ADM 30 mg/4 weeks and MMC 4 mg/2 weeks) and CDDP methods (only CDDP 10 mg/week). Cases of esophagus carcinoma were treated with FAM method. On the CT-scan one of the cases showed the reduction rate of more than 50% and was a Progressive Response (PC), and the SCC tumor marker decreased in 2 cases. However, 2 other cases died of liver failure. Cases of larynx were treated with FAM and CDDP methods. However, on the CT-scan all of the cases showed No Change (NC) nor decrease in SCC. But thinking of prognosis FAM was better than CDDP. Cases of cervix of uterus were treated with the FAM and CDDP methods. FAM was not different than the CDDP in the prognosis and effect.

Aged↗
PubMed1991

[Influence of Lp(a) on restenosis after coronary angioplasty].

We clarified the relationship between lipoprotein (a) concentration and restenosis after coronary angioplasty (PTCA). The lipoprotein (a) concentration in patients with restenosis after PTCA was significantly higher than in patients without restenosis after PTCA (33.0 +/- 19.8 mg/dl vs 19.1 +/- 17.4 mg/dl, p less than 0.05]. Moreover, patients with a lipoprotein (a) concentration of more than 30 mg/dl had a high rate of restenosis after PTCA. Restenosis after PTCA is related to lipoprotein (a) concentration.

Aged↗
PubMed1991

[Clinical observations and the planning of therapy for sacrococcygeal tumors].

Amongst sacrococcygeal tumors, teratoma is seen often while other histologic types are rare. It is apparent that the less obvious intrapelvic tumors can cause obstructive symptoms and are usually diagnosed late. Twenty cases of sacrococcygeal tumor, including 14 teratomas (9 benign, 5 malignant) and 6 others (3 benign, 3 malignant) were treated at Tokyo Medical College and Shizuoka Children's Hospital over the last 23 years. The majority of the benign tumors were readily excised, but one case of benign teratoma was difficult to excise and died of bleeding. The resectability of malignant tumors was low, but aggressive multiagent chemotherapy, radiotherapy and second look operation made it possible to increase the survival. One case is alive and has been disease free for 11 years. Recently combined therapy by chemotherapy and surgery has improved the survival rate although some problems still remain.

Child, Preschool↗
PubMed1991

[Gallbladder function and CCK after gastrectomy].

Postgastrectomy cholelithiasis has become a problem and biliary tract dyskinesia has been cited as an etiologic factor. CCK is the most important gut hormone with respect to biliary tract function, so we conducted an experimental study of postgastrectomy gallbladder function and CCK levels which gave the following results: 1. Although postprandial gallbladder contraction for the most part occurred in response to endogenous CCK, another mechanism (the gastro-cholecystic reflex) seemed to be responsible for some of them. 2. The postgastrectomy decrease in postprandial gallbladder contraction appeared to be due to disappearance of this gastro-cholecystic reflex. 3. Gallbladder contraction occurred in association with postprandial CCK secretion following total gastrectomy and Roux-en-Y reconstruction, but the altered food passage route caused changes in the dynamics of CCK secretion, and this is believed to have had an influence on the gallbladder contractile response.

Animals↗
PubMed1991

[Subfrontal schwannoma: a case report].

A case of a 63-year-old woman with subfrontal schwannoma of the left side is presented. The patient had a two-month history of recent memory disturbance and unstable gait. Computed tomography represented an isodense mass lesion with large and small cystic components in the anterior cranial fossa, enhancing homogeneously after intravenous injection of contrast medium. Cerebral angiograms revealed a noticeable hypovascularity. She underwent total resection of the tumor on May 21, 1986. It was verified that the tumor was attached to the left olfactory groove and had invaded the ethmoid bone. It was suggested that this tumor arose from one of the meningeal branches of the trigeminal nerve or of the anterior ethmoid nerve. Histological examination proved that this neoplasm was of schwannoma.

Brain Neoplasms↗
PubMed1991

[A simple method of retrograde intubation].

A safe and simple method to facilitate retrograde intubation was presented. An epidural catheter was introduced into the oropharynx through a 16-G extracath sheath inserted through the cricothyroid membrane into the trachea. After passing the catheter beyond the distal end of the endotracheal tube, a knot was made. Intubation was done by pulling the catheter, which can be cut apart and pulled out afterwards. This method would make the damage or contamination of the cricothyroid membrane minimum and the trouble of losing the catheter could be abolished. We believe this way of intubation can be applied universally because it needs no special tool or device.

Aged↗
PubMed1991

[The effect of temperature on the action of several neuromuscular blocking agents in vitro].

The effects of lowered muscle temperature on the action of neuromuscular blocking drugs have been investigated so far from basic or clinical aspects, but the results of these studies are conflicting probably because of the differences of methods and/or species of the animals. The effects of hyperthermia on neuromuscular junction are not yet known. To clarify the effects of variations in temperature on the neuromuscular blockade produced by each of the 5 neuromuscular blocking agents in current use (vecuronium, pancuronium, pipecuronium, dTc, SCC), we used the rat phrenic nerve-hemidiaphragm preparation and compared the ED50 at each temperature with that at 37 degrees C. The temperatures examined were 17 degrees C, 27 degrees C, 32 degrees C, 37 degrees C, 40 degrees C, and 42 degrees C. As to vecuronium and pancuronium, potentiating effects were observed with both hypothermia and hyperthermia. In contrast, pipecuronium was not affected by the change of temperature from 27 degrees C to 42 degrees C. SCC was only potentiated at the temperatures of 27 degrees C and 17 degrees C, while dTc showed a biphasic phenomenon by hypothermia. The ED50's of dTc at 37 degrees C and 27 degrees C were twice as large as that of at 32 degrees C, but ED50 of 17 degrees C was significantly lower than that of 37 degrees C. Hyperthermia did not modify the neuromuscular blockade by dTc.

Animals↗
PubMed1990

Mechanochemical coupling in actomyosin energy transduction studied by in vitro movement assay.

In order to study the mechanochemical coupling in actomyosin energy transduction, the sliding distance of an actin filament induced by one ATP hydrolysis cycle was obtained by using an in vitro movement assay that permitted quantitative and simultaneous measurements of (1) the movements of single fluorescently labeled actin filaments on myosin bound to coverslip surfaces and (2) the ATPase rates. The sliding distance was determined as (the working stroke time in one ATPase cycle, tws) x (the filament velocity, v). tws was obtained from the ATPase turnover rate of myosin during the sliding (kt), the ATP hydrolysis time (delta t) and the ON-rate at which myosin heads enter into the working stroke state when they encounter actin (kON); tws approximately 1/kt-delta t-1/kON. kt was estimated from the ATPase rates of the myosin-coated surface during the sliding of actin filaments. delta t has been determined as less than 1/100 per second, kON was estimated by analyzing the movements of very short (40 nm) filaments. The resulting sliding distance during one ATP hydrolysis cycle near zero load was greater than 100 nm, which is about ten times longer than that expected for a single attachment-detachment cycle between an actin and a myosin head. This leads to the conclusion that the coupling between the ATPase and attachment-detachment cycles is not determined rigidly in a one-to-one fashion.

Actins↗
PubMed1990

Apolipoprotein B-48 analysis by high-performance liquid chromatography in VLDL: a sensitive and rapid method.

Apolipoprotein (apo) B subspecies were separated by high-performance liquid chromatography (HPLC) to analyze Apo B-48 contents in very-low-density lipoproteins (VLDL) more easily. Apo B-100 and B-48 were eluted through two connected column of Shim-pack Diol-300 at a retention time of 24 min and 32.3 min, respectively. The molecular masses estimated by this method were approximately 600 kDa in apo B-100, 220 kDa in apo B-48. % apo B-48 in total apo B (% B-48) determined by measuring peak area of HPLC-separated apo B in a healthy subject was 76% in chylomicrons, 13% in fasting VLDL, and 20% in 2 h-postprandial VLDL. No peak of apo B-48 was detected in LDL. Recovery of Apo B determined by re-chromatography of HPLC-separated sample was 91 +/- 4.0% and 95 +/- 3.6% in Apo B-100 and apo B-48, respectively. 125I-labeled apo B in VLDL were also analyzed by both HPLC and SDS-PAGE. Percent radioactivity of apo B-48 fraction in the total apo B determined by the HPLC (17.3%) was similar to the value obtained through the measurement of radioactivity separated by the SDS-PAGE (17.6%). Coefficient of variation in % B-48 determined by the peak area was 2.5%. Percent B-48 determined by the HPLC method was significantly correlated with % B-48 by SDS-PAGE, but 6-8 times higher, which might be accounted for in part by the reported difference of chromogenicity between apo B-100 and apo B-48. % B-48 in VLDL separated from fasting plasma were 17.1 +/- 5.6% in 14 healthy subjects, and positively related to VLDL triglyceride and cholesterol concentrations. Apo B isoprotein analysis by the HPLC method is reliable and easy to perform for studying apo B metabolism in triglyceride-rich lipoproteins in physiological as well as pathological conditions.

Adult↗
PubMed1990

Structural studies on three flavin-interacting regions of the flavoprotein subunit of complex II in Ascaris suum mitochondria.

The flavoprotein (Fp) subunit of mitochondrial complex II contains covalently bound FAD as a prosthetic group. In this study, the primary structure of the flavin-bound tryptic peptide from the Fp subunit of Ascaris complex II was determined and found to be highly similar to those of the corresponding flavin-binding regions of bovine heart and bacterial Fp subunits. Furthermore, the Ascaris Fp subunit was shown to contain two regions exhibiting striking sequence similarity to the segments that have been predicted to interact noncovalently with the AMP moiety of FAD in bacterial Fp subunits. The conservation of these two regions also in the mitochondrial Fp subunit suggests their functional importance.

Amino Acid Sequence↗
PubMed1990

Infiltrative and cytolytic activities of lymphokine-activated killer cells against a human glioma spheroid model.

In the present study, we investigated not only the cytotoxic effects of lymphokine-activated killer (LAK) cells on a tumor mass but also the ultrastructural cell-to-cell interaction between LAK effector cells and tumor cells during the cytolytic process within a three-dimensional solid tumor. A multicellular tumor spheroid of a human glioma cell line (U-251MG) was utilized as a solid tumor model. LAK cells were generated from peripheral blood lymphocytes of a healthy donor after stimulation by interleukin 2. Multicellular tumor spheroids with diameters of 500 microns were cocultivated with either LAK cells or nonactivated peripheral blood lymphocytes at the effector:target cell ratio of 20:1, and then time-sequential kinetic, morphological, and ultrastructural analyses were carried out. Morphological and kinetic studies showed that LAK cells directly infiltrated toward the inner areas of multicellular tumor spheroids and caused a progressive tumor destruction. In contrast, peripheral blood lymphocytes hardly exhibited such activities. Ultrastructurally, it was found that the infiltrating LAK effector cells were composed of heterogeneous subpopulations, T-like cells, and large granular lymphocyte-like cells. Both types of lymphocytes tightly adhered to the tumor cells and showed typical morphological features of killing them.

Cell Line↗
PubMed1990

Decreased susceptibility of lined human gliosarcoma cells to lymphokine-activated killer cell cytolysis by gamma-interferon treatment.

The susceptibility of the established cultured gliosarcoma line GI-1 to lymphokine-activated killer (LAK) cells was analyzed with and without interferon (IFN)-gamma treatment of target GI-1 cells. IFN-gamma treatment decreased the susceptibility of GI-1 cells to LAK cell cytolysis in a dose-dependent manner. Acid treatment of GI-1 cells increased their susceptibility to cytolysis compared with untreated cells. IFN-gamma treatment and acid treatment of GI-1 cells respectively increased and decreased the expression of class I HLA antigens on GI-1 cells. The susceptibility of GI-1 cells to LAK cell cytolysis and their expression of HLA class I molecules were inversely correlated. Subpopulation depletion experiments on the LAK cells with monoclonal antibodies and complement revealed that phenotypically natural killer type (CD16+) cells had a high cytotoxic activity against untreated GI-1 cells but a relatively low activity against IFN-gamma-treated GI-1 cells in both the precursor and effector phases. On the other hand, phenotypically T-type (CD3+) cells did not show these tendencies at all in both the precursor and the effector phases.

Antigens, Differentiation↗
PubMed1990

Purification and characterization of a novel beta-agarase from Vibrio sp. AP-2.

beta-Agarase was purified from the culture fluid of a porphyran-decomposing marine bacterium (strain AP-2) by ammonium sulfate precipitation, successive column chromatography and DNase and RNase treatment. The final enzyme preparation appeared to be homogeneous on polyacrylamide gel electrophoresis. The enzyme had a molecular mass of 20 kDa, a pH optimum of 5.5, and was stable in the pH region 4.0-9.0 and at temperatures below 45 degrees C. The beta-agarase was a novel endo-type enzyme which hydrolyzed neoagarotetraose, larger neoagarooligosaccharides and agar to give neoagarobiose [3,6-anhydro-alpha-L-galactopyranosyl-(1----3)-D-galactose] as the predominant product. The enzyme did not act on kappa-carrageenan. According to the criteria of Bergey's Manual of Systematic Bacteriology, the strain was assigned to the genus Vibrio.

Chromatography↗
PubMed1990

Continuous flow determination of nitrite with membrane separation/chemiluminescence detection.

A method for the determination of nitrite in water utilizing a membrane separation process and a chemiluminescence detector, with the addition of air-stripping and air-carrier, is proposed. The microporous poly(tetrafluoroethylene) tube was used as separator to transfer nitric oxide (reduced by iodine in acidic media) into a gas phase. Air-stripping was used to enhance the separation. Chemiluminescence signals produced from the reaction of nitric oxide with ozone were linearly proportional to the concentration of nitrite from 10 ppb (micrograms as N/L) to 5 ppm (mg N/L). The relative standard deviation (n = 5) was 0.7% at 0.1 ppm. The time elapse from starting the sample flow until the signal reached a stable level was 1.5 min.

Chromatography, High Pressure Liquid↗