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Biomedical subjects

H Sakamoto

Publications and source records attributed to H Sakamoto.

At least 595 records · Page 33Linked to original sources
PubMed1992

Abnormality of background EEG determined by the entropy of power spectra in epileptic patients.

Relationships between epileptiform discharges and background activity were examined by power spectral entropy (PSE), measuring a degree of EEG irregularity. The EEGs were recorded from 10 electrodes placed at F3, F4, C3, C4, T3, T4, P3, P4, O1 and O2 in 11 epileptic patients with widespread lateralized spike and wave complexes (SWCs). Bipolar records were also made from the antero-posterior derivations. The locations of the maximum PSE coincided with those of the maximum amplitude of SWC in most of the patients. Bipolar derivations with the maximum PSE always included the locations with the maximum PSE obtained from a linked ears reference. Pearson's correlation coefficient between PSE and SWC amplitude was 0.62 +/- 0.14 (mean +/- S.D.) in 11 patients, thus indicating that the scalp distribution of PSE was closely related to that of the amplitude of SWC. These findings suggest that the background EEG is disorganized in or near the epileptogenic focus. A focal background abnormality can therefore be estimated by PSE.

Adolescent↗
PubMed1992

Both adenylate cyclase and hemolytic activities are required by Bordetella pertussis to initiate infection.

Among virulence factors synthesized and secreted by Bordetella pertussis, pertussis toxin (PTX) and the bifunctional adenylate cyclase-hemolysin (AC-Hly) are able to invade mammalian cells and to impair intracellular functions. Moreover, both proteins are protective antigens in murine intracerebral and respiratory models. In order to study their in vivo properties, different B. pertussis mutants, deficient in AC-Hly expression or secretion, or producing modified AC-Hly devoid of either adenylate cyclase or hemolytic activities, were constructed and examined. The in vivo properties of the mutants were compared to PTX deficient strains, using the murine respiratory model. We show that lack of PTX as well as adenylate cyclase or hemolytic activities results in avirulence. Furthermore, we show that mutants lacking adenylate cyclase or hemolytic activities were unable to multiply as fast as the parental strains and PTX mutants during the first 5 days following infection. Thus, both adenylate cyclase and hemolytic activities are required by B. pertussis to initiate infection.

Adenylate Cyclase Toxin↗
PubMed1992

Congenital midline sinus of the upper lip. Report of a case.

The occurrence of a congenital midline sinus of the upper lip is rare, only 22 cases having been previously reported. This case report describes the excision of a congenital midline sinus of the upper lip in a 2-year-old girl.

Child, Preschool↗
PubMed1992

Regulation of endothelin-1 production in cultured rat mesangial cells.

We investigated the regulatory mechanisms of endothelin (ET)-1 production in cultured rat mesangial cells (MC), with a special focus on the roles of protein kinase A (PKA)- and protein kinase C (PKC)-mediated signaling systems. Vasoactive agents and growth promoting factors, including platelet-derived growth factor, vasopressin and thrombin, which act through receptors coupled to the phospholipase C-mediated signaling system, as well as phorbol ester and fetal calf serum stimulated ET-1 production. This effect was attenuated in PKC-depleted or H-7 (a PKC inhibitor) treated MC. On the other hand, an increase in intracellular cyclic AMP by forskolin or beta-adrenergic agonist, isoproterenol, which act as anti-mitogenic agents, inhibited serum-stimulated ET-1 production. In addition this effect was mimicked by the addition of 8-bromo-cyclic AMP to the medium. The effect of isoproterenol was abolished by propranolol. H-8, a PKA inhibitor, attenuated the inhibitory effect of forskolin. These findings suggest that ET-1 production in MC is regulated by interaction of both positive and negative signals mediated by PKC- and PKA-dependent mechanisms.

Animals↗
PubMed1992

Differential changes in expression of gap junction proteins connexin 26 and 32 during hepatocarcinogenesis in rats.

We examined expressions of the gap junction proteins, connexin 26 (Cx26) and 32 (Cx32), in preneoplastic and neoplastic lesions during rat hepatocarcinogenesis. A marked reduction in the number of Cx32-positive gap junctions was observed in 17% of the glutathione S-transferase placental form-positive foci, whereas 44% of the foci showed increased expression of Cx26. Most hyperplastic nodules exhibited decreased expression of Cx32, whereas 16% of the nodules showed increased expression of Cx26. In hepatocellular carcinomas, expressions of both Cx32 and Cx26 were significantly reduced. These results suggest that the expressions of Cx32 and 26 are differentially regulated during hepatocarcinogenesis, and that the decrease in Cx32 expression occurs earlier, whereas reduction in Cx26 expression occurs later in association with promotion and progression of carcinogenesis.

Animals↗
PubMed1992

Studies on macromolecular activators of phagocytosis from platelets (MAPPs) using anti MAPP murine monoclonal antibodies.

1-MAPP(290 kD) and s-MAPP(150 kD) are glycoproteins which have been shown to be involved in released products from platelets (PRPr) and to activate monocyte and neutrophil phagocytosis via the Fc receptors. Three IgG 2a (kappa) murine monoclonal antibodies against 1-MAPP and nine IgG1 (kappa) antibodies against s-MAPP have been raised. By affinity chromatography using these monoclonal antibodies, active MAPPs were obtained from the supernatant of outdated platelet concentrates in the presence of 60% saturated ammonium sulphate and from PRPr-rich medium, and substantial amounts of non-functioning immunoreactive MAPPs were obtained from the precipitate. Fab fragments of one of the two anti 1-MAPP and of two of the four anti s-MAPP monoclonal antibodies inhibited the function of their corresponding MAPPs, but none of them could inhibit the other MAPPs. 1-MAPP and s-MAPP in the platelets were visualized by indirect fluorescent antibody technique using Fab fragments of the antibodies.

Animals↗
PubMed1992

Escape of phagocytosis-activating function from platelets into plasma during storage.

Stimulation of the phagocytic activity of leukocytes by two glycoproteins, the macromolecular activators of phagocytosis 1-MAPP and s-MAPP, involved in platelet release products (PRPr), was not observed when platelet concentrate (PC), stored longer than 48 h, was used as a platelet source. The supernatant of the PC (Sup) acquired this activity during storage. Salting out with ammonium sulfate (AS) revealed that the phagocytosis-enhancing activity was recovered in the supernatant of Sup from PC with 60% saturated AS, and the reverse activity, phagocytosis suppression, was observed in the precipitate with 30% AS. Suppressing activity was observed in PRPr prepared from both fresh and 48-h-old PC. The phagocytosis-enhancing activity observed in the Sup from the 48-hour PC was characterized by Sephadex G200 gel filtration and consisted of two peaks (300 and 150 kD), matching these of l-MAPP and s-MAPP in the PRPr prepared from fresh platelets. These results indicate that l-MAPP and s-MAPP escape from platelets into the plasma during storage, whereas the suppressing activity is retained in platelets for at least 48 h.

Blood Platelets↗
PubMed1992

Evaluation of plasma erythropoietin levels in normal adult dogs by in vivo bioassay using concentrated plasma.

Measurement of plasma erythropoietin level in normal dogs by in vivo bioassay has been considered to be impossible so far. In the present study, we successfully determined it by using concentrated plasma 60 times which allowed the lower limit to 2.7 mU/ml. This normal plasma erythropoietin level was the first to be determined as an in vivo bioactivity and was 9.14 +/- 7.81 mU/ml in 75 normal adult dogs. This value was sufficiently reliable in terms of accuracy of determination and considered to be meaningful as the low level in vivo bioactivity that hasn't been known to date. Furthermore, erythropoietin levels in normal plasma were within a certain lower range and showed neither difference in plasma erythropoietin level between males and females or among breeds nor correlation between erythropoietin and hemoglobin level.

Animals↗
PubMed1992

The embryo pancreas is a source of increased yolk amylase in the fertilized eggs of domestic fowls.

The amylases were studied in the yolk of fertilized eggs and in the pancreases of the embryos of domestic fowls. The amylase activity in the yolk increased markedly from 13 days of incubation until hatching, but the activity decreased when the embryos were taken out of the eggs. The isoamylases in the yolk and in the pancreas of the embryo were identical electrophoretically. The amylase occurs mainly in the pancreas of the embryo. We think that the increase in amylase activity in the yolk of fertilized eggs during incubation depends upon the accumulation of pancreatic amylase synthesized by the developing embryo in the egg.

Amylases↗
PubMed1992

[Trends in antihypertensive drugs used for elderly patients].

The admission of antihypertensive medications in the elderly (65 y.o. or more, 269 pts) was compared to that in younger cases (less than 65 y.o., 348 pts). All were outpatients who visited our clinic in 1990. The number of patients on a single therapeutic regimen was almost equal in both age groups. Once-a-day regimens were more common in the young (56.9% vs 48.3%, p less than 0.05), and three times-a-day regimens were more common in the elderly (14.7% vs 23.1%, p less than 0.01). The choice of antihypertensive drugs in patients with single therapy or combined therapy in the young was beta blockers in 49.7%, Ca blockers in 39.4%, diuretics in 30.7% and ACE inhibitors in 17.8%, and those in the elderly were Ca blockers in 46.1%, diuretics in 44.2%, beta blockers in 33.8%, and ACE inhibitors in 16.4%. The patients were subdivided into three groups according to the time of the initial visit to the clinic; initial visit during 1969-1979 (phase 1), 1980-1984 (phase 2) and 1985-1990 (phase 3). In the young, choice of beta blockers and diuretics was most popular in phase 1. However, the choice of diuretics decreased in phase 2, and in phase 3 beta blockers were used in 50.4%, Ca blockers in 43.2%, ACE inhibitors in 22.3% and diuretics in only 17.3%. In the elderly, diuretics were most popular followed by Ca blockers and beta blockers in phase 1 and phase 2. In phase 3 Ca blockers were selected in 58.2% followed by both beta blockers and ACE inhibitors in 28.4% then diuretics in 23.9%.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Isolation of plasma cholesterol-lowering components from ningyotake (Polyporus confluens) mushroom.

The present study was undertaken to isolate component(s) which contributes to the hypocholesterolemic action of Ningyotake (Polyporus confluens) mushroom. The mushroom powder was extracted with 80% ethanol, and the extract and residue were fractionated into five fractions according to the solubility to solvents. When each fraction was added to a diet containing 1% cholesterol and 0.25% sodium cholate and fed to rats, the plasma cholesterol level was significantly decreased only by ethyl acetate-soluble fraction. Therefore, ethyl acetate-soluble fraction was further fractionated by silica gel column chromatography. Two major compounds, which comprised 45.0% and 28.5% of the ethyl acetate-soluble fraction, were obtained in a pure form by the chromatography, and the compounds were identified as grifolin (2-trans, trans-farnesyl-5-methylresorcinol) and neogrifolin (4-trans, trans-farnesyl-5-methylresorcinol), respectively. The addition of grifolin and neogrifolin to the high cholesterol diet was found to lower plasma cholesterol level significantly.

Animals↗
PubMed1992

Innervation of an aberrant digastric muscle in the posterior thigh: stratified relationships between branches of the inferior gluteal nerve.

During dissection of the gluteal region and the posterior thigh, an aberrant digastric muscle was observed on the right side of a 77-y-old Japanese male cadaver. This originated from the sacrotuberous ligament and inserted into the lateral surface of the long head of biceps femoris. Based on its innervation, this aberrant muscle may be homologous with the femorococcygeus.

Aged↗
PubMed1992

[Role of p185c-erbB2 in endometrial cancer growth in vitro].

Human endometrial adenocarcinoma cells (Ishikawa line) constitutively express c-erbB2 coded oncoprotein p185erbB2 (p185) which is believed to be an orphan receptor for an unknown growth factor. Since we have shown that expression of p185 in primary lesions of endometrial cancer correlates well with high frequency of lymph node++ metastases and that the metastatic cells in the nodes strongly expressed p185, the role of the oncoprotein in processes of metastases was studied. Culturing the cells in the presence of 15% FCS and with monoclonal antibody to the extracellular domain of p185 (CB-1) inhibited cell growth and attenuated p185 expression on Western blotting, whereas no change occurred with the control antibody. Cells cultured without FCS achieved only approximately 1/3 growth compared to cells with FCS, and further suppression of growth was observed after adding CB-1. When cells were cultured on human term amnion, basement membrane invasion with p185 expression was observed. In nude mice, intraperitoneal seeding resulted in implant formation which was also associated with positive p185 as well as cyclin immunohistochemistry. In the two experiments, treatment of cells with CB-1 inhibited invasion or implant formation. The present study suggests that a signal through p185 receptor molecules acts as a trigger for early proliferation, and interaction with the host may enhance up-regulation of p185.

Adenocarcinoma↗
PubMed1992

[Prader-Willi syndrome associated with chromosomal aberration: report of a case].

A male case of Prader-Willi syndrome (2.8 years in age) with an interstitial deletion of a chromosome affecting 15q 11-12 region is reported. The chief complaints were hypoplastic scrotum and defect of bilateral scrotal content. The clinical features were short stature, obesity, delayed mental development, bilateral cryptorchidism, hypogenitalism, hypopigmentation, and bilateral moderate vesicoureteral reflux with a history of muscular hypotonia. Bilateral orchidopexy was done. Endocrinologically both base values of luteinizing hormone (LH) and follicle stimulating hormone (FSH) were normal although LH reserve function was impaired on gonadotropin releasing hormone (GnRH) test. Testosterone response was normal by the stimulation of human chorionic gonadotropin. An interstitial deletion of proximal 15q, and pituitary-gonadal axis in Prader-Willi syndrome are discussed in relation to the clinical features and therapy.

Child, Preschool↗
PubMed1992

[Effects of administration of three kinds of catecholamine on mitral complex].

To evaluate cardiac injury induced by injection of 3 kinds of catecholamine, 219 male rabbits were examined. Eighty-five to 100 percent of the animals having high doses of adrenaline and noradrenaline showed ventricular premature contraction, and 65 to 75 percent of them showed mitral complex injury; whereas, these effects were identified in none or only in 10 percent of the animals with isoproterenol injection. The cardiac injury was similar to that of vagal stimulation, which was reported previously. These results indicate that ventricular premature contractions are important for developing the adrenaline- and noradrenaline-induced mitral complex injury.

Animals↗
PubMed1992

[Cap brace: a new treatment for newborn and infant congenital muscular torticollis].

Herein is reported a new treatment, using a cap brace, for congenital muscular torticollis (CMT) in newborn and infant. The subjects consisted of 72 cases undergoing cap brace treatment (CB-group), and 197 cases undergoing ordinary treatment (O-group) for CMT. In children of the O-group, the rolling-over developmental stage was later than in normal infants, while in those of the CB-group this stage was not delayed. The good prognostic factors for lessening cranial and facial asymmetry, evaluated by chi-square test, were as follows: partus praematurus, a high APGAR score, breast-feeding, an early start to rolling-over, early vanishing of the sternomastoid tumor, and early vanishing of limitation of neck movement. For discriminant analysis of the factors related to cranial and facial asymmetry, the quantification method of the second type was used. In the O-group, discrimination between asymmetry and no asymmetry was achieved (R = 0.832), but in the CB-group the factors involved could not be discriminated. Moreover, ultratomosonography was very useful for examining the sternomastoid muscle. The internal echogenicity changed from low to high with aging, and was the echo pattern was classified as types I to IV accordingly. Patients with an early change from type I to type II tended to show good results in cranial and facial asymmetry. This brace was developed with an improvement of the other similar braces. But unlike other devices our brace did not fix the infant's head in one position for correction. And as a result of this virtue, the sternomastoid muscle of the affected side was relaxed and the vanishing periods of asymmetrical tonic neck reflex are hastened. Use of this brace improved the cure rate and was especially effective in decreasing cranial and facial asymmetry.

Age Factors↗