Search PubMed⌕ Search

Biomedical subjects

S Maeda

Publications and source records attributed to S Maeda.

At least 703 records · Page 39Linked to original sources
PubMed1990

[Recordings of evoked electromyographic responses from the extraocular muscles to monitor the oculomotor, trochlear, and abducens nerve function during skull base and orbital surgery].

The methods to record evoked electromyographic responses by micro malleable clip electrodes applied directly to the extraocular muscles are described. This electrophysiological monitoring enables surgeons to localize the ocular motor nerves accurately in the skull base of the middle, posterior fossa, and orbit. In cavernous sinus surgery, electrical stimulation over the dura elicited vigorous responses from the extraocular muscles and subsequently it was possible for the surgeon to avoid severing the ocular motor nerves. In orbital surgery, distended and thinned extraocular muscles were precisely localized and preserved anatomically and functionally. These monitoring methods may play the same role as electrical stimulation to the facial nerves in acoustic neuroma surgery.

Abducens Nerve↗
PubMed1989

Increased insecticidal effect by a recombinant baculovirus carrying a synthetic diuretic hormone gene.

Genetically engineered insect viruses may be potential alternatives to conventional chemical insecticides. A recombinant gene for the diuretic hormone of the tobacco hornworm, Manduca sexta, has been introduced into a baculovirus, Bombyx mori nuclear polyhedrosis virus (BmNPV). When silkworm larvae were injected with the resulting recombinant BmNPV, the diuretic hormone was expressed, causing a strong alteration in larval fluid metabolism. The recombinant virus killed infected larvae about 20% faster than the original virus.

Amino Acid Sequence↗
PubMed1989

EGF stimulates anchorage-independent growth of a human bladder carcinoma cell line (KU1) with an amplified and over-expressed EGF receptor gene.

Southern blot analysis of 6 human bladder carcinoma cell lines revealed amplification of the epidermal growth factor receptor (EGFR) gene in the KU1 cell line. The amplification of the gene was about 4-fold as compared with that of human placental DNA. Several restriction endonuclease digestions revealed that there was no gross rearrangement of the EGFR gene in KU1. Northern blot analysis showed normal 10 and 5.6 kb of EGFR gene-related mRNA species. 125I-EGF binding revealed 2 distinct EGF binding sites on KU1 cells: high-affinity sites 5.7 X 10(5) receptors per cell with 1.1 nM Kd and low-affinity sites 2.3 X 10(6) receptors per cell with 7.4 nM Kd. The number of the EGFR was compatible with that of the A431 squamous carcinoma cell ine which has an amplified, rearranged and over-expressed EGFR gene. Solid-phase immuno-isolation analysis showed a single 170 kDa EGFR protein in KU1 as well as in A431. Unlike other cell lines with amplified and over-expressed EGFR gene, anchorage-dependent growth of KU1 was stimulated but not inhibited by EGF. Moreover, anchorage-independent growth of KU1 was stimulated by EGF.

Antibodies, Monoclonal↗
PubMed1989

Suppression of c-myc mRNA expression by steroid hormones in HTLV-I-infected T-cell line, KH-2.

The effects of 1,25(OH)2D3 and dexamethasone on cellular proliferation and gene expression of the HTLV-I-infected T-cell line, KH-2, established from a patient with adult T-cell leukemia, endemic in the south-west Japanese islands and the Caribbean, were examined. KH-2 cells are integrated by HTLV-I proviral DNA and expressed mRNA for c-myc, IL-2 receptor alpha-chain (IL-2R alpha), and T-cell receptor beta-chain (TCR beta) while it did not express IL-2 mRNA. 1,25(OH)2D3 and dexamethasone did not suppress the mRNA levels of HTLV-I, IL-2R alpha or TCR beta but reduced the c-myc mRNA level. The reduction of c-myc mRNA level was marked in 1,25(OH)2D3-treated cells but relatively weak in dexamethasone-treated cells. This inhibitory effect of the steroid hormones correlated with the inhibition of KH-2 cell proliferation.

Blotting, Northern↗
PubMed1989

Effects of pentazocine and other opioids on the potassium-evoked release of [3H]noradrenaline from guinea pig cortical slices.

Noradrenaline release and its modulation via presynaptic opioid receptors were examined in guinea pig cortical slices. Slices preloaded with [3H]noradrenaline were superfused in the presence of desipramine (1 microM) and were stimulated by 16 mM K+. 1-Pentazocine inhibited the K+-evoked release of [3H]noradrenaline in a dose-dependent manner (3 x 10(-7)-10(-5) M), while d-pentazocine did not inhibit. This inhibitory effect of 1-pentazocine was antagonized by Mr 2266 (10(-6) M) but not by naloxone (10(-6) M). Among other opioids, dynorphin A-(1-13) and ethylketocyclazocine (kappa agonists) decreased the K+-evoked release of [3H]noradrenaline. Tyr-D-Ala-Gly-NMe-Phe-Gly-ol (DAGO, mu agonist) also inhibited [3H]noradrenaline release but was less potent than the kappa agonists. [D-Pen2,D-Pen5]enkephalin (DPDPE, delta agonist) and phencyclidine (sigma agonist) had no effects on the stimulated release of [3H]noradrenaline. Thus, it was shown that kappa receptors are the major subtype of opioid receptor involved in modulation of noradrenaline release in guinea pig cortex, and that 1-pentazocine inhibits the K+-evoked release of noradrenaline through activation of these receptors.

Animals↗
PubMed1989

Liver-specific and high-level expression of human serum amyloid P component gene in transgenic mice.

To analyze the regulation of human serum amyloid P component (SAP) gene expression, we have produced seven transgenic mice. The 3.3 kb human SAP genes containing about 0.8 kb of 5' and 1.5 kb of 3' flanking region were injected into fertilized eggs of C57BL/6 mice. In five of the seven transgenic mice, human SAP was detected in the sera and serum concentrations were higher than that of human serum in three lines. The human SAP gene was expressed only in the liver. Amounts of human mRNA in the liver and serum concentrations of human SAP were roughly proportional to the copy number of the integrated gene. Human SAP production lowered the serum levels of mouse endogenous SAP. With the intraperitoneal administration of lipopolysaccharide, the mRNA levels in the liver and serum levels of mouse SAP increased several-fold in both the control and transgenic mice. On the other hand, neither the mRNA nor the serum levels of human SAP increased significantly.

Animals↗
PubMed1989

In situ DNA-RNA hybridization using in vivo bromodeoxyuridine-labeled DNA probe.

An in vivo 5'-bromodeoxyuridine (BrdUrd) labeled DNA probe was used for in situ DNA-RNA hybridization. BrdUrd was incorporated into plasmid DNA by inoculating E. coli with Luria-Bertani (LB) culture medium containing 500 mg/L of BrdUrd. After purification of the plasmid DNA, specific probes of the defined DNA fragments, which contained the cloned insert and short stretches of the vector DNA, were generated by restriction endonuclease. The enzymatic digestion pattern of the BrdUrd-labeled plasmid DNA was the same as that of the non-labeled one. BrdUrd was incorporated in 15%-20% of the total DNA, that is, about 80% of the thymidine was replaced by BrdUrd. Picogram amounts of the BrdUrd-labeled DNA probe itself and the target DNA were detectable on nitrocellulose filters in dot-blot spot and hybridization experiments using a peroxidase/diaminobenzidine combination. The BrdUrd-labeled DNA probe was efficiently hybridized with both single stranded DNA on nitrocellulose filters and cellular mRNA in in situ hybridization experiments. Through the reaction with BrdUrd in single stranded tails, hybridized probes were clearly detectable with fluorescent microscopy using a FITC-conjugated monoclonal anti-BrdUrd antibody. The in vivo labeling method did not require nick translation steps or in vitro DNA polymerase reactions. Sensitive, stable and efficient DNA probes were easily obtainable with this method.

Bromodeoxyuridine↗
PubMed1989

Splenic hamartoma: report of a case and review of the literature.

A 39-year-old Japanese man with a splenic hamartoma who underwent surgery, is reported herein. The patient had a volvulus of the transverse colon and acute Type A hepatitis. His symptoms included fever, abdominal pain and icterus and the serum chemistry showed liver dysfunction and an elevation of hepatitis A antibody levels. Barium enema revealed a volvulus of the transverse colon. Ultrasonogram showed a hypoechoic mass and angiogram showed evidence of stretching of the intrasplenic vessels in the arterial phase and a hypovascular mass lesion in the venous phase. Macroscopically, the tumor was a well-defined, whitish-yellow, hard nodule. Microscopically, the tumor was composed of fibrous scar tissue containing scattered red pulp tissues and the histologic diagnosis was a splenic hamartoma of the fibrous type. The patient's postoperative recovery was uneventful. The clinical features of splenic hamartoma are reviewed in this report and the differential diagnosis is also discussed.

Adult↗
PubMed1989

Lymphangioma of the stomach--report of a case and review of the literature.

A rare case of a 66 year old man with lymphangioma of the stomach is presented herein. Upper gastrointestinal X-ray series revealed a slow growing submucosal tumor in the anterior wall of the antrum of the stomach which was subsequently found to be lymphangioma after a partial gastrectomy. To our knowledge, this is only the thirteenth case of lymphangioma of the stomach to have been reported in the English literature. A brief review of the English and Japanese literature is presented following the case report.

Aged↗
PubMed1989

Lipoprotein(a) in nonhuman primates. Presence and characteristics of Lp(a) immunoreactive materials using anti-human Lp(a) serum.

Lipoprotein(a) (Lp(a] immunoreactive materials were examined in serum samples from 77 nonhuman primates of 24 species by Ouchterlony's double diffusion procedure and an enzyme-linked immunosorbent assay (ELISA) using rabbit antisera to human Lp(a). The precipitates obtained with sera from orang-utan and chimpanzee formed reactions of complete identity with the Lp(a) precipitate with human serum. When sera from Old World monkeys and human subjects were tested in wells next to each other, spurs developed between the 2 precipitates, indicating that Lp(a)-like lipoproteins in Old World monkeys have partial identity with human Lp(a). Lp(a) immunoreactive materials were identified in association with lipids by means of fat staining of the precipitates. On the other hand, reactants which could be precipitated with anti-human Lp(a) sera were not detectable in prosimians and New World monkeys. These results suggest that serum Lp(a)-like lipoprotein is phylogenetically acquired in Old World monkeys. However, the possibility that the structures of serum Lp(a)-like lipoproteins in prosimians and New World monkeys are too different to react with anti-human Lp(a) sera cannot be ruled out.

Animals↗
PubMed1989

Transient changes of serum lipoprotein(a) as an acute phase protein.

Serum lipoprotein(a) (Lp(a)) was serially determined after acute attacks of myocardial infarction and after surgical operations. Acute phase proteins, such as C-reactive protein, alpha 1-acid glycoprotein, alpha 1-antitrypsin and haptoglobin, increased rapidly and markedly after the episodes. Initial values of serum Lp(a) concentrations were almost the same in both groups. Increases in serum Lp(a) levels were also observed during the first few days, with a return to the initial levels after more than 1 month. The periods for reaching maximal levels of acute phase proteins were similar in both groups of patients. On the contrary, the period required for Lp(a) to reach the maximal level in the myocardial infarction group was significantly longer than in the post-operative group. The present study suggests that Lp(a) has the characteristics of an acute phase reactant and may play an important role in recovery from tissue damage.

Acute-Phase Proteins↗
PubMed1989

Age- and diabetes-accelerated glycation in the human aorta.

The extent of glycation in pieces of human aorta was estimated by determining the content of furosine, which is derived from fructose-lysine through acid hydrolysis. Glycation of human aorta was found to increase with advancing age. A significant positive correlation was found between the degree of atherosclerosis and the furosine level in the aorta in subjects over 60 years of age. Furthermore, the furosine level in the aortae of diabetic patients was significantly higher than that in normal subjects of the same age. These results suggest not only that glycation in the aorta may increase with aging and with the development of arteriosclerosis, but also that diabetes may be related as well to premature aging as to arteriosclerosis.

Adult↗
PubMed1989

Establishment and characterization of mouse leukemia cell lines L615K and L7212K derived from transplantable murine leukemias maintained in China.

Two culture cell lines L615K and L7212K were established from transplanted murine leukemias L615 and L7212, which had been established and maintained in China for years. Based on morphological, immunological and gene rearrangement analyses, L7212K cells are considered to be of T-cell origin while L615K cells might be immature T-cells. Immunofluorescence assays of viable leukemia cells and fluorescence focus assays of their culture supernate for infectious viruses suggested that recombinant mink cell focus-inducing viruses were significantly involved in both leukemic cell lines. Chromosome analysis of the L615K cells revealed a translocation t(12;17) which probably involved the c-fos locus on chromosome 12, since the DNA rearrangement of c-fos was demonstrated by Southern blot analysis with Hind III, and c-fos has been assigned to this chromosome. Although the expression of this gene was not detected by RNA Northern blot analysis, c-myc was slightly expressed in both L615K and L7212K cells.

Animals↗
PubMed1989

Adenocarcinoma in Meckel's diverticulum: case report and literature review.

A case of adenocarcinoma arising in Meckel's diverticulum in a 55 year old man is reported, and a brief review of the literature is presented. The patient developed low abdominal pain and showed elevation of serum carcinoembryonic antigen (CEA) level. The tumour was located in the apical portion of the diverticulum and extended into the mesenterium. Histologically, the tumour was a well-differentiated adenocarcinoma arising in the Meckel's diverticulum. Immunohistochemical study showed that malignant cells were positive for CEA. The noteworthy feature of this case is the pre-operative elevation of serum CEA level and the immunohistochemical demonstration of CEA in the cancer cells.

Adenocarcinoma↗
PubMed1989

The mechanisms of reversible immobilization of fowl spermatozoa at body temperature.

Intact fowl spermatozoa became almost immotile at 40 degrees C, but motility increased significantly at 30 degrees C. The oxygen consumption at both temperatures was 8-11 microliters O2/10(10) spermatozoa.min-1. The ATP concentration at 40 degrees C was higher than that at 30 degrees C but ADP concentration at 30 degrees C was higher than that at 40 degrees C. Consequently, the ATP/ADP ratio at 30 degrees C (1.9-2.2) increased to 3.5-3.7 at 40 degrees C. The motility of intact spermatozoa at 40 degrees C was effectively restored by 2 mM-Ca2+, 10% seminal plasma and 10% peritoneal fluid taken at the time of ovulation. In contrast, these effectors did not restore the motility of demembranated spermatozoa at 40 degrees C. Motility of demembranated spermatozoa was restored at 30 degrees C. These results suggest that the immobilization of fowl spermatozoa at 40 degrees C occurs due to a decrease in flagellar dynein ATPase activity. Furthermore, the action of effectors for motility such as Ca2+ may not be directly on the axoneme, but mediated by solubilized substances which have been removed by demembranation of the spermatozoa.

Adenosine Diphosphate↗