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Biomedical subjects

Y Okabe

Publications and source records attributed to Y Okabe.

At least 91 records · Page 5Linked to original sources
PubMed1991

[Newly devised subcutaneous needle electrodes for EMG recording].

Subcutaneous needle electrodes made of stainless steel were newly devised for ease of handling and perfect insulation. This needle (phi 0.20 mm) is used for acupuncture. The electrodes had the capability to record the EMG activity easily from a certain muscle. Then, the EMG activities of the masseter muscle were recorded with both these needle electrodes and surface electrodes and the results were compared. 1. Insertion of the electrodes into the subcutaneous tissue was easily performed because of the application of the acupuncture needle and their lightness of 0.2g was effective in fixing the electrodes on the skin without causing any tension. 2. After the insertion of the needle electrodes, the impedance showed below 5 kohm immediately, and the EMG recordings during biting could be simply achieved with great stability. 3. The action potential from the needle electrodes was less than that from the surface ones. The former reacted more sensitively to the change in the distance between the electrodes, compared with the latter.

Action Potentials↗
PubMed1991

[Tumor hemodynamics in hepatic nodules associated with liver cirrhosis: relationship between cancer progression and tumor hemodynamic change].

Tumor hemodynamics including arterial vascularity (AV) and portal perfusion (PP) were evaluated in histologically confirmed 55 hepatic nodules associated with cirrhosis using ultrasonographic (US) angiography during intraarterial carbon dioxide microbubbles injection and CT during arterial portography. Tumor hemodynamic patterns were classified into 6 types as follows: Type I (n = 10): PP (+), AV (hypo); Type I' (n = 2): PP (+), AV (iso); Type II (n = 5): PP (-), AV (hypo); Type III (n = 8): PP (-), AV (iso); Type IV (n = 25): PP (-), AV (hyper), Type V (n = 5): PP (partially +), AV (vascular spot in hypovascular). Eight nodules of Type I were diagnosed as benign nodules histologically including adenomatous hyperplasia (AH) (n = 6) and regenerative nodule (n = 2). Hundred percent (5/5) of Type II and 88% (7/8) of Type III nodules were well-differentiated HCC, in contrast to 8% (2/25) of Type IV nodules, typical HCCs. Fatty metamorphosis was observed in 75% (6/8) of Type III nodules, in contrast to 16% (4/25) of typical (classical) HCC nodules (Type IV). We concluded that at the malignant transformation from AH to HCC, reduction of portal blood flow in the nodule precedes the initiation of the increase of the arterial tumor vessel. Moreover, early stage HCC could exhibit hypovascular (Type I, II), isovascular (Type III), or vascular spot in hypovascular pattern (Type V) compared with a typical HCC (Type IV). It was also suggested that the more mature as a neoplasms the HCC becomes, the more the arterial tumor vessel in the nodule increases and fatty metamorphosis of well-differentiated HCC is highly related with tumor hemodynamic condition, i.e., hypoperfusion state from both arterial and portal vessel.

Carcinoma, Hepatocellular↗
PubMed1990

Human gamma delta T-cell receptor-positive cell-mediated inhibition of erythropoiesis in vitro in a patient with type I autoimmune polyglandular syndrome and pure red blood cell aplasia.

The gamma delta T-cell receptor-positive (gamma delta TCR+) lymphocytes were markedly expanded up to 68% of peripheral blood lymphocytes in a case with type I autoimmune polyglandular syndrome and pure red blood cell aplasia (PRCA). The gamma delta TCR+ cells showed CD4 negative, 16% dim-CD8 positive and 10% to 46% human leukocyte antigen-D-related (HLA-DR) positive, and exhibited no monoclonality as assessed by the patterns of TCR gene rearrangements. Functional studies revealed that the proliferative responses of the patient's peripheral blood mononuclear cells (PBMC) were severely depressed to candida antigen, alloantigens, and autoantigens (non-T cells). The gamma delta TCR+ cells had no suppressive effect on the proliferative response of the alpha beta TCR+ cells to candida. The patient's PBMC, isolated gamma delta TCR+ cells but not alpha beta TCR+ cells, exhibited non-major histocompatibility complex (MHC)-restricted cytotoxicity. Furthermore, the patient's PBMC and isolated gamma delta TCR+ cells inhibited burst-forming units-erythroid (BFU-E), but not colony-forming units/granulocyte-macrophage (CFU-GM). Supernatants derived from the patient's T cells similarly inhibited BFU-E but not CFU-GM. The clinical course of the patient also showed a close correlation between the decreased number of total lymphocyte counts, especially HLA-DR + gamma delta TCR+ cell counts, and recovery from PRCA. These observations suggest that the gamma delta TCR+ cells might be functional in vivo and involved in the pathogenesis of PRCA in this patient.

Adult↗
PubMed1989

Intravagal parathyroid adenoma.

An extremely rare case of intravagal parathyroid adenoma is presented. The tumour caused fusiform swelling of the left vagus nerve was shelled out. Post-operatively the left recurrent nerve palsy was recovered in the two months. Serum calcium level returned to normal on the tenth day after the surgical operation without symptoms of hypocalcaemia.

Adenoma↗
PubMed1989

Primary structure of a ribonuclease from bullfrog (Rana catesbeiana) liver.

A pyrimidine base-specific ribonuclease was purified from bullfrog (Rana catesbeiana) liver by means of CM-cellulose column chromatography and affinity chromatography on heparin-Sepharose CL-6B, which gave single band on SDS-slab electrophoresis. The primary structure of the bullfrog liver RNase was determined. It consisted of 111 amino acid residues, including 8 half-cystine residues. From the sequence, it was concluded that three disulfide bridges in RNase A were conserved in the bullfrog RNase, that a disulfide bridge in RNase A [Cys65-Cys126 (RNase A numbering)] was deleted, and that a new disulfide bridge was created in the C-terminal part of the enzyme. In this frog RNase, the amino acid residues thought to be essential for catalysis in bovine pancreatic RNase A were conserved except for Asp121 (RNase A numbering). The sequence homology of the bullfrog liver RNase with bovine pancreatic RNase A was 30.6%. The sequence of bullfrog liver RNase was very similar to those of lectins obtained from bullfrog egg by Titani et al. [Biochemistry (1988) 26, 2189-2194] and R. japonica egg by Kamiya et al. [Seikagaku (in Japanese) (1989) 60, 733; and personal communication from Kamiya, Y., Oyama, F., Oyama, R., Sakakibara, F., Nitta, K., Kawauchi, H., and Titani, K.]. The sequence homology between the bullfrog liver RNase and the two lectins was 70.2 and 64.8%, respectively.

Amino Acid Sequence↗
PubMed1989

Bowen's disease with invasive carcinoma showing sweat gland differentiation.

A 75-year-old Japanese woman presented an erythematous macular lesion on the flexor aspect of her left wrist. A reddish nodule, 4 mm in diameter, was observed at the medial portion of the macule. The macular lesion was histologically confirmed to be a typical Bowen's disease. The nodular lesion was composed of intradermal solid nests of bowenoid neoplastic cells, and in some areas of the dermal component, prominent gland-like structures were observed. Immunohistochemically, most neoplastic cells of the intradermal solid nests were positive with S-100 protein, and the cells lining the gland-like structures along with amorphous material within the lumens were positive with carcinoembryonic antigen. Judging from these findings, this case was diagnosed as Bowen's disease with invasive carcinoma, whose dermal component showed sweat gland differentiation not only morphologically but also immunohistochemically.

Aged↗
PubMed1988

Effect of an amino group at carbon 2 of 1-deoxyglucose analogues on anorexia in the rat.

A steric hindering group at carbon 2 of 1-deoxyglucose analogues was introduced by epimerization, deoxidation and substitution of a hydroxyl group with either an acetamido or a fluoro group. Injection of this analogue into the rat third cerebroventricle attenuated the feeding suppression produced by 1-deoxyglucose. In contrast, the replacement of a hydroxyl group at carbon 2 with an amino group produced anorexia of the same magnitude as that produced by 1-deoxyglucose. Amination at carbon 2 was more potent than that at carbon 3, 4 or 6. These results indicate that an amino group at carbon 2 of the glucose molecule is important to reinforce the feeding suppression caused by 1-deoxyglucose analogues.

Animals↗
PubMed1988

Differential mechanisms of feeding modulation induced by amino sugars in rats.

The present study examined and compared the effects of N-acetylglucosamine and 1-deoxy-N-acetylglucosamine on feeding behavior with those of glucosamine and 1-deoxyglucosamine. Infusion of 12 mu mole N-acetylglucosamine and 24 mu mole 1-deoxy-N-acetylglucosamine into the rat third cerebroventricle did not affect the feeding behavior. However, oral administration of 1200 mumol N-acetylglucosamine elicited feeding and 2400 mumol 1-deoxy-N-acetylglucosamine markedly suppressed feeding. These effects were abolished by truncal vagotomy. Both glucosamine and 1-deoxyglucosamine affected feeding by intra-third cerebroventricular and oral administration. These findings indicate that N-acetyl amino sugars modulate feeding behavior peripherally through the vagal afferent nerve.

Acetylglucosamine↗