Biomedical subjects

K Satoh

Publications and source records attributed to K Satoh.

At least 685 records · Page 38Linked to original sources

PubMed1993

Studies of a key protein in the mechanism of the excitation-contraction coupling process of frog skeletal muscle, using phenylglyoxal.

The excitation-contraction (E-C) coupling process in single twitch fibres from frog toe muscle was inhibited selectively by phenylglyoxal (PGO), a specific guanidyl modifying reagent. A new protein (31.5 kDa), which has PGO-binding ability and seems to play a key role in the E-C coupling process, was solubilized from transverse tubule membrane-junctional sarcoplasmic reticulum complexes (TTM-JSR) of frog skeletal muscles, using 14C-PGO. The monoclonal antibody against this protein applied extracellularly inhibited the E-C coupling process of the single fibres. This protein appears to constitute the very first step of input for E-C coupling. It is considered to behave as an indispensable part of an 'electrometer' to measure membrane potentials. Therefore, the name 'electrometrin' is suggested for the new protein.

Animals↗

PubMed1993

Involvement of ATP-sensitive K+ channels in the sustained coronary vasodilator response to adenosine in dogs.

Coronary vasodilator mechanisms of adenosine were investigated in isolated canine papillary muscle preparations cross-circulated through the anterior septal artery with support dogs. Infusions of adenosine (1-3000 nmol/min) for 3 min into this artery caused a transient increase (the initial phase) in blood flow followed by a sustained increase (the sustained phase), and single-bolus intra-arterial injections of adenosine (0.3-1000 nmol) produced only a transient increase in blood flow. The force of contraction of the papillary muscle was virtually unaffected. The increase in blood flow in the sustained phase was antagonized by glibenclamide (6 mumol/kg i.v.), a blocker of ATP-sensitive K+ channels, administered to support dogs whereas increases in both phases were antagonized by 8-phenyltheophylline (12 mumol/kg i.v.), a non-selective adenosine receptor antagonist, administered in a similar way. The transient increase in blood flow caused by single-bolus injections of adenosine was reduced in duration rather than in peak value by glibenclamide. Thus, it appears that opening of ATP-sensitive K+ channels gradually becomes involved in the vasodilator mechanisms for adenosine A2 receptor-mediated, sustained vasodilation.

Adenosine↗

PubMed1993

ATP-dependent protein synthesis in isolated pea chloroplasts. Evidence for accumulation of a translation intermediate of the D1 protein.

In the presence of externally added ATP, in the dark, isolated pea chloroplasts accumulate two proteins of molecular masses of about 22 and 24 kDa which precipitate with specific antibodies raised against the D1 protein. By chasing in the light, these proteins disappeared on the fluorogram concomitant with the appearance of the precursor- and mature-sized D1 proteins. Polysome analysis indicated that the 22-kDa component is associated with membrane-bound ribosomes and is thus ascribed to a translation intermediate of the D1 protein. On the other hand, the 24-kDa component could not be found in the polysome fraction under the experimental condition used, suggesting the possibility that this component is a degradation product of the D1 protein. The conclusion from this analysis is that the synthesis and/or stable accumulation of the D1 protein requires factor(s) caused by illumination, in addition to ATP, in isolated pea chloroplasts.

Adenosine Triphosphate↗

PubMed1993

Effects of catechins on the mouse lung carcinoma cell adhesion to the endothelial cells.

We studied the effects of 5 kinds of catechins on the adhesion of mouse lung carcinoma 3LL cells to the monolayer of bovine lung endothelial cells. (-)-Epicatechin gallate and (-)-epigallocatechin gallate were active in inhibiting the 3LL cell adhesion, while (+)-catechin and (-)-epicatechin were inactive. (-)-Epigallocatechin showed a considerable cytotoxicity. These data suggest that the specific chemical structure is required to exert the inhibitory activity of catechins and the search for the cellular binding protein(s) bound to these inhibitory catechins would provide a clue to clarify the mechanism of interactions between tumor cells and endothelial cells.

Animals↗

PubMed1993

Lumbar artery pseudoaneurysm: an unusual cause of a retroperitoneal hematoma: report of a case.

Pseudoaneurysm of the lumbar artery is a rare complication of penetrating trauma. We present herein a case thought to have been caused by a blow to the left flank without any evidence of a stab wound. In this patient, the diagnosis of a first lumbar artery pseudoaneurysm with a retroperitoneal hematoma was confirmed by computed tomography (CT) findings, after which transcatheter embolization was successfully performed.

Aneurysm↗

PubMed1993

Aesthetic camouflage of bilateral cleft lip scars: technical revisions.

We have attempted to change the two scar lines of bilateral cleft lip repair into one zigzag scar line. The prolabium is used to push up the columella and the nasal tip. The donor site of the prolabium is closed by transposition of the nasolabial flap. The postoperative scar shows one zigzag line at the center of the lip. This method has many advantages including an inconspicuous scar, repair of the short columella and flat nasal tip, repair of a wide nose, and repair of the whistling deformity. Complications of this method are maxillary retardation, long lip deformity, and keloid formation. However, these can be avoided by modifying the method.

Adolescent↗

PubMed1993

Relationship between immunological parameters and survival of patients with liver metastases from breast cancer given immuno-chemotherapy.

We treated 33 patients with liver metastases from breast cancer by immuno-chemotherapy including adoptive cell transfer between 1987 and 1992. In this study, we examined the change of immunological parameters in the peripheral blood lymphocytes and interleukin-2 (IL-2)-cultured lymphocytes, in primary vs. metastatic breast cancer patients and before vs. after treatment. Moreover, we examined their correlation with therapeutic response and survival after treatment. The immunological parameters used were in vitro natural killer cell activity (% lysis of K562), in vitro autologous tumor-killing activity (% lysis against autologous freshly isolated tumor cells), and proliferation of lymphocytes stimulated with IL-2 and autologous sonicated tumor extract antigen in mixed culture (IL-2-enhanced MLTR). When compared with primary breast cancer patients, patients with liver metastases showed a significant decrease in % lysis of K562 and autologous tumor cells. After treatment, the stimulation index in IL-2-enhanced MLTR increased significantly from the pretreatment level and correlated with survival after treatment. Moreover, non-specific immunological parameters (performance status, lymphocyte count, and transferred cell count and proliferation rate of cultured lymphocytes) were significantly associated with response and prognosis.

Adult↗

PubMed1993

Nicorandil as a nitrate, and cromakalim as a potassium channel opener, dilate isolated porcine large coronary arteries in an agonist-nonselective manner.

Nicorandil is an antianginal vasodilator having a hybrid property between nitrates and potassium channel openers, and cromakalim is a relatively specific potassium channel opener. We investigated whether or not the vasorelaxant actions of the two drugs would be selective for certain vasoconstrictor agonists (simply agonists hereafter), and the underlying mechanisms in isolated porcine large coronary arteries. Both nicorandil and cromakalim produced a complete relaxation in the arteries precontracted with seven agonists, i.e., Bay-K-8644, endothelin, histamine, 5-hydroxytryptamine (5-HT), phenylephrine, PGF2 alpha, and U 46619. The EC50 values (-log M) of nicorandil and cromakalim were 5.20-5.44 and 6.43-6.87, respectively, toward the seven agonists, indicating that the vasorelaxant actions of the two drugs were agonist nonselective. In the arteries precontracted with Bay-K-8644, endothelin, 5-HT, and U 46619, the vasorelaxant action of cromakalim was antagonized by glibenclamide, an antagonist of potassium channel openers, and Schild analysis of these antagonisms yielded pA2 values of 7.10-7.41 for glibenclamide. The vasorelaxant actions of nicorandil in the arteries precontracted with the four agonists each were not antagonized by glibenclamide. Instead, the vasorelaxant action of nicorandil was antagonized by methylene blue (10 microM), an inhibitor of guanylate cyclase, and slightly potentiated by M&B 22,948 (10 microM), an inhibitor of cyclic-GMP phosphodiesterase, in the arteries precontracted with U 46619. These results indicate that the vasorelaxant actions of nicorandil and cromakalim in the porcine large coronary artery are agonist nonselective and that nicorandil exerts such an action entirely as a nitrate, whereas cromakalim does so entirely as a potassium channel opener.

Animals↗

PubMed1993

The therapeutic effect of OK-432-combined adoptive immunotherapy against liver metastases from gastric or colorectal cancers.

Twenty-four patients with liver metastases from gastric or colorectal cancer were treated with OK-432-combined adoptive immunotherapy (AIT). Lymphocytes isolated from regional lymph nodes or peripheral blood were cultured with medium containing T cell growth factor and sonicated tumor extract antigen (SE-Ag) for 9-13 days. The cultured lymphocytes were transferred mainly through the hepatic artery after the administration of OK-432, a streptococcal preparation. Sixteen of the 24 patients received a low dose of anti-cancer agents between the OK-432 injection and cell transfer. When cultured without SE-Ag, regional lymph node lymphocytes (RLNL) showed significantly (P < 0.05) higher cytotoxic activity against autologous tumor cells and, on the contrary, lower cytotoxic activity against K562 than peripheral blood lymphocytes (PBL). When cultured with SE-Ag, cytotoxicity of RLNL against autologous tumor cells was nearly equivalent to that of PBL. The blastogenesis of fresh PBL to SE-Ag was significantly (P < 0.05) augmented after the OK-432-combined AIT. Two patients showed complete response and 4 patients showed partial response among 19 patients who had evaluable lesions. Five patients whose liver metastases were resected were treated with OK-432-combined AIT as an adjuvant therapy. To date they are alive without recurrence in the liver.

Adult↗

PubMed1993

Cellular interaction against autologous tumor cells between IL-2-cultured lymphocytes and fresh peripheral blood lymphocytes in patients with breast cancer given immuno-chemotherapy.

In patients with Stage II or III breast cancer and in patients with liver metastases from breast cancer, we examined cellular interaction in the cytotoxicity against autologous tumor cells by interleukin-2(IL-2)-cultured lymphocytes (CL) and fresh peripheral blood lymphocytes (FPBL) treated with immunochemotherapy including OK-432 and cyclophosphamide. In flow cytometric analysis, CD8+CD11b+ and CD16+ cells significantly decreased after immuno-chemotherapy in both groups of patients. A protocol study in Stage II or III breast cancer patients showed suppressive activity of FPBL on the cytotoxic activity of CL in 3/9 of the non-treatment group but no suppressive activity and enhancing activity in 3/7 in the immuno-chemotherapy group. Moreover, in 19 patients with liver metastases from breast cancer treated with immuno-chemotherapy including adoptive immunotherapy, FPBL in 6/19 showed enhancing activity, and in 8/19 suppressive activity in the lysis of autologous tumor cells. In assays in vitro using autologous and allogeneic tumor cells, FPBL showed a partial specificity in cellular interaction against autologous tumor cells. CD4-depleted FPBL inhibited cytotoxicity of CL, while CD8-depleted FPBL enhanced cytotoxicity of CL in patients with liver metastases. These results suggest that immuno-chemotherapy eliminates the suppressive population in FPBL and may induce tumor regression if combined with adoptive immunotherapy using CL.

Adjuvants, Immunologic↗

PubMed1993

The point mutation of c-Ki-ras at codon 12 in carcinoma of the pancreatic head region and in intraductal mucin-hypersecreting neoplasm of the pancreas.

In order to clarify whether the detection of a point mutation in the c-Ki-ras gene at codon 12 in tumor tissues can assist in predicting the tumor's biological grade of malignancy, two types of tumors were investigated; one was called "carcinoma in the pancreatic head region," and the other was intraductal mucin-hypersecreting neoplasm of the pancreas (IMHN). Dot hybridization and a modified PCR technique developed by Haliassos et al. were employed. Among 16 cases of tumors in the pancreatic head region, the point mutation was detected with a high frequency only in pancreatic ductal cell carcinomas (five out of six cases, 83.3%), but was not detected in extrahepatic bile duct carcinomas (0/5) or in ampullary carcinomas (0/5). In pancreatic ductal cell carcinomas, no relation was found between the occurrence of the point mutation and the histological type of the tumor. Among 20 cases of IMHNs, the point mutation was found in 11 cases (55%). No relation was found between the occurrence of the mutation and the size of IMHNs. However, as the grade of cell atypia increased, the frequency of the mutation tended to become higher. These results suggest that detection of this point mutation might be useful for distinguishing pancreatic ductal cell carcinoma from those of other origins in the pancreatic head region, and for the determination of the histopathological grade of malignancy in IMHNs.

Aged↗

PubMed1993

Effect of 17 beta-estradiol on secretion of platelet-activating factor acetylhydrolase by HepG2 cells.

Estrogen has been shown to decrease plasma platelet-activating factor (PAF) acetylhydrolase activity, but the precise mechanisms are not known. We examined the effect of estradiol on the secretion of PAF acetylhydrolase by HepG2 cells. In our previous study, we demonstrated the production of this enzyme by HepG2 cells, which we used as an experimental model of normal hepatocytes. 17 beta-Estradiol mildly but consistently inhibited the secretion of PAF acetylhydrolase by HepG2 cells in a concentration-dependent manner. Under basal conditions, HepG2 cells secreted 42.3 pmol/mg cell protein/min PAF acetylhydrolase in 24 hours (mean of 8 dishes), and the presence of 10(-7) mol/L 17 beta-estradiol decreased the secretion to 77% +/- 10.3% of control values (mean +/- SD, n = 8, P < .02). 17 beta-Estradiol treatment affected neither the secretion of apolipoprotein (apo) A-I nor cell-associated PAF acetylhydrolase activity. Electrophoretic separation of [35S]methionine-labeled PAF acetylhydrolase revealed a single band whose molecular weight was approximately 43,000 d. We conclude that estrogen decreases the secretion of PAF acetylhydrolase by the liver, and it may explain, at least in part, the effect of estrogen on plasma PAF acetylhydrolase.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

PubMed1993

Regional cerebral blood flow in catatonic schizophrenia.

Single photon emission computed tomography (SPECT) with 123I-iodoamphetamine (IMP) as tracer was used to study regional cerebral blood flow (rCBF) distribution in six patients with the catatonic subtype of schizophrenia (DSM-III-R). IMP-SPECT imaging revealed a significant reduction of rCBF in the parietal lobes of both hemispheres. Three-dimensional reconstruction of the SPECT images identified the superior region of the frontoparietal lobe as the most severely affected region. The pattern of rCBF deficits observed in catatonic schizophrenia differs markedly from that seen in 13 patients with other subtypes of schizophrenia and 7 normal control subjects. These observations indicate that parietal lobe dysfunction may be an important component in the pathology of the catatonic subtype of schizophrenia.

Adolescent↗

PubMed1993

Lung cancer mortality among a cohort of male chromate pigment workers in Japan.

In 1975, five manufacturers of chromate pigment in Japan were examined in a study of the carcinogenicity of chromates. These companies were producing lead chromate, zinc chromate, molybdate orange and/or strontium chromate. The current study covers a cohort of 666 workers involved in the manufacture of chromate pigment for at least 1 year between 1950 and 1975. The workers were followed up for 15-40 years, until 1989. Many previous reports have found an excess lung cancer risk among workers involved in the manufacture of chromate pigments and chromate chemicals. In the current study, subjects were classified on the basis of years worked, years of observation, characteristics of company, type of work engaged in for the longest period of time, and involvement in the manufacture of zinc chromate. Mortality was compared with that of all Japanese males by means of the person-year method. The route of exposure was primarily inhalation through the respiratory system. None of the results showed statistically significant differences that would suggest an excess risk for malignant neoplasms, particularly lung cancer, among workers engaged in the manufacture of chromate pigment in Japan.

Cause of Death↗

PubMed1993

Comparative study of reverse flow island flaps in the lower extremities--peroneal, anterior tibial, and posterior tibial island flaps in 25 patients.

The reverse flow island flap is one of the most versatile reconstructive procedures in the lower extremity. There are three major arteries, the peroneal, the anterior tibial, and the posterior tibial artery, and a reverse flow island flap pedicled by each vessel and its intermuscular cutaneous perforators is available. Twenty-five reverse flow island flaps were clinically applied for soft tissue defects in the lower leg (10 peroneal, 8 anterior tibial, and 7 posterior tibial flaps). We report a comparative study of the characteristics and indications of the peroneal, anterior tibial, and posterior tibial reverse flow flaps. We conclude that the anterior tibial reverse flow flaps are more likely, without venous anastomosis, to become congested and necrose than the peroneal and posterior tibial flaps.

Adult↗

PubMed1993

Speech and velopharyngeal function following maxillary advancement in patients with cleft lip and palate.

The influence of maxillary advancement by osteotomy on speech was examined in 10 patients with cleft palates (6 males, 4 females). Ages at the time of surgery ranged from 16 to 26 years (mean, 19.5 yr). LeFort I and II osteotomies were performed in 9 patients and 1 patient, respectively. Preoperatively and postoperatively, hypernasality, nasal emission on pressure consonants, and articulation disturbances were evaluated perceptually, and velopharyngeal function was evaluated by lateral cephalographic and nasopharyngoscopic studies. Hypernasality, which had been judged preoperatively to be absent or slight in 1 patient each, remained unchanged after surgery, whereas the remaining 8 patients showed increased hypernasality after surgery. Nasal emission showed a similar tendency. Articulation errors were not improved postoperatively. Lateral cephalograms recorded from the patients with increased hypernasality showed increases in the shortest palatopharyngeal length and in the soft-palate-length--to--pharyngeal-depth ratio. Also, deterioration in velopharyngeal closure was noted postoperatively compared with preoperatively by nasopharyngoscopy in the majority of patients with increased hypernasality.

Adolescent↗

PubMed1993

A new osteotomy for genioplasty--stepped osteotomy: preliminary report.

A new osteotomy for genioplasty, stepped osteotomy, is described. This osteotomy is a combination of horizontal and sagittal osteotomy of the mandibular symphysis. It consists of horizontal osteotomy at a distance of 3 to 4 mm below the apexes of the anterior teeth, connecting at right angles with the conventional horizontal osteotomy below the mental foramen, making a step-fashioned osteotomy of the chin. This procedure is particularly advantageous in simultaneous elongation and advancement genioplasty because the central portion between the apexes of the anterior teeth and the conventional horizontal osteotomy line is available as augmentation and the bony contact of the osteotomized mandible can be retained in elongating the chin. The characteristics of this procedure are described and typical patients are shown.

Adolescent↗

PubMed1993

Correction of prominent zygomata by tripod osteotomy of the malar bone.

Reduction of the prominent zygomata is occasionally required in aesthetic surgery in Oriental patients. Two approaches to surgical exposure are commonly used; one is oral and the other is coronal. In addition, there are two basic surgical concepts of reduction malar-bone plasty; one is thinning and chiseling the prominent area, and the other is mobilizing the prominent zygoma by osteotomy of the zygomata. We devised a new tripod osteotomy of the zygomata by the coronal exposure approach and applied it to correct prominent zygomata in association with frontoperiorbital lifting in Oriental patients. Satisfactory results were obtained and we concluded that this was an effective procedure to correct prominent zygomata for elderly Oriental patients.

Adult↗