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Biomedical subjects

K Hanawa

Publications and source records attributed to K Hanawa.

At least 19 recordsLinked to original sources

Outcome of traumatic optic neuropathy. Comparison between surgical and nonsurgical treatment.

34 patients with indirect traumatic optic neuropathy were studied to identify factors affecting outcome and surgical indications. 12 cases (13 eyes = group A) underwent surgery and 24 patients (24 eyes = group B) were managed without surgery. Age, optic canal fracture, visual acuity before treatment (initial visual acuity) and days until surgery (only group A) were employed as variables. Visual acuity improved significantly more in patients with initial visual acuity, hand movement (HM) or better than in those with initial visual acuity for light perception (LP) only or worse. When initial visual acuity was HM or better, vision improved significantly more in patients with surgery than in those without surgery (p = 0.0003 by Mann-Whitney U test). Days until surgery were correlated with visual improvement in patients with visual acuity HM or better. Age and optic canal fracture did not affect visual improvement or influence the decision for or against surgery.

Adult↗

Presence and location of modified nucleotides in Escherichia coli tmRNA: structural mimicry with tRNA acceptor branches.

Escherichia coli tmRNA functions uniquely as both tRNA and mRNA and possesses structural elements similar to canonical tRNAs. To test whether this mimicry extends to post-transcriptional modification, the technique of combined liquid chromatography/ electrospray ionization mass spectrometry (LC/ESIMS) and sequence data were used to determine the molecular masses of all oligonucleotides produced by RNase T1 hydrolysis with a mean error of 0.1 Da. Thus, this allowed for the detection, chemical characterization and sequence placement of modified nucleotides which produced a change in mass. Also, chemical modifications were used to locate mass-silent modifications. The native E.coli tmRNA contains two modified nucleosides, 5-methyluridine and pseudouridine. Both modifications are located within the proposed tRNA-like domain, in a seven-nucleotide loop mimicking the conserved sequence of T loops in canonical tRNAs. Although tmRNA acceptor branches (acceptor stem and T stem-loop) utilize different architectural rules than those of canonical tRNAs, their conformations in solution may be very similar. A comparative structural and functional analysis of unmodified tmRNA made by in vitro transcription and native E.coli tmRNA suggests that one or both of these post-transcriptional modifications may be required for optimal stability of the acceptor branch which is needed for efficient aminoacylation.

Base Composition↗

Escherichia coli tmRNA (10Sa RNA) in trans-translation.

Here we show that Escherichia coli tmRNA (10Sa RNA) has a dual function both as an mRNA and as a tRNA in vitro. The function as a tRNA is prerequisite for the function as an mRNA. These observations strongly support the trans-translation hypothesis.

Amino Acid Sequence↗

[Chest wall reconstruction using polyester mesh].

From January 1987 through December 1994, we performed chest wall reconstruction using the polyester mesh in 15 patients with lung cancer, 11 with empyema after open drainage, 8 with chest wall tumor and 1 with radiation dermatitis and costal chondritis. Twenty five patients were resected 3 or more ribs. Chest wall defects were reconstructed with the polyester mesh covered with Gore-Tex soft tissue patch. Twenty two cases passed more than a year without signs of infection and follow-up averaged 27.6 months. Polyester mesh was removed due to bronchial fistula (3 cases), deformities (3 cases) and abscess formation (1 case). In these cases, polyester mesh was well incorporated and had no foreign body change. In conclusion, the polyester mesh seems to be a dependable prosthetic material for chest wall reconstruction.

Adult↗

[Anatomical study of the cavernous nerve in relation to nerve sparing operation].

Recently, nerve sparing radical prostatectomy has became widely considered as the primary goal for maintaining a high standard of quality of life (QOL). However, anatomical localization of the cavernous nerve has not yet been precisely clarified in terms of the terminal end in the corpus cavernous penis distal to the urogenital membrane. Here in attempt to demonstrate the precise localization of the cavernous nerve, in six adult male cadaver. The cavernous nerves ran between the prostatic capsule and the prostatic fascia, through the capsule of the seminal vesicle. The nerves penetrated the membranous urethra at 8 mm from the margin of the urethra at the position of 5 and 7 o'clock. Therefore, the following procedures are critical to achieve successful nerve sparing: 1) meticulous division of the seminal-vesicle, 2) precise separation of the neurovascular bundle between the prostatic capsule and fascia, and 3) the careful transaction of the membranous urethra.

Aged↗

[Inhibitory effects of vasoactive intestinal peptide on superoxide anion generation from stimulated human inflammatory cells].

Vasoactive intestinal peptide (VIP) is suspected to be a neurotransmitter of nonadrenergic and noncholinergic inhibitory nerves in human respiratory tracts. Although VIP affects T lymphocytes through its specific receptor, the effects of VIP on inflammatory cells except T lymphocytes are obscure. We investigated the effects of VIP on superoxide anion (O2-) generation from five kinds of human cells; neutrophils, eosinophils and mononuclear cells isolated from peripheral blood, alveolar macrophages obtained from the bronchoalveolar lavage, and human monocyte cell line, U937, the capacity of which for O2- generation was induced by interferon-gamma. O2- generation from human cells stimulated by 10(-5) M fMLP was measured by the cypridina luciferin analog, MCLA, -dependent chemiluminescence method. VIP inhibited O2- generation from fMLP-stimulated neutrophils, mononuclear cells and U937 in a dose-dependent manner. 3 x 10(-6) M VIP inhibited O2- generation from fMLP-stimulated eosinophils and alveolar macrophages significantly. These results indicate that VIP might inhibit the activation of inflammatory cells and act as an antiinflammatory agent.

Cells, Cultured↗

Polyamines stimulate the phosphorylation of phosphatidylinositol in rat mast cell granules.

Rat mast cell granules were obtained by homogenization of highly purified rat mast cells and isolated in a Percoll gradient. Diphosphoinositide (DPI) synthesis in rat mast cell granules was assayed by measuring the incorporation of 32P from [gamma 32P] ATP into DPI in the absence of exogenous phosphatidylinositol (PI). Lipids were isolated with methanol/chloroform/HCl and were separated by thin-layer chromatography on oxalic acid impregnated silica gel plates. DPI areas were identified by staining with iodine, scraped and measured for 32P radioactivity. The addition of polyamines, spermine and spermidine, to the granules caused an increase of DPI synthesis, which can be catalyzed by PI kinase. This effect of polyamines in the DPI synthesis was in a dose-dependent manner and maximal effects were observed at 1 mM spermine and 10 mM spermidine, respectively.

Animals↗

Inhibitory effects of azelastine on superoxide anion generation from activated inflammatory cells measured by a simple chemiluminescence method.

Blood was drawn from healthy human volunteers and neutrophils and eosinophils were purified on a Conray-Ficoll and a Percoll gradient, respectively. Rat mast cells were also purified on a Percoll gradient. Superoxide anion (O2-) generation from the cells were measured by 2-methyl-6-[p-methoxy-phenyl]-3,7-dihydroimidazo[1,2-a]pyrazin+ ++-3-one (MCLA)-dependent luminescence. Addition of 0.5 mumol/l MCLA and a stimulatory agent, such as phorbol myristate acetate, N-formyl-methionyl-leucyl-phenylalanine (fMLP) and compound 48/80, to a suspension of each cell caused a marked luminescence which was inhibited by 0.5 mumol/l superoxide dismutase (SOD). Azelastine (A-5610) significantly inhibited the O2- generation from each activated inflammatory cell in a dose-dependent manner. When eosinophils were activated by fMLP in the presence of cytochalasine (CB), azelastine abolished the luminescence stronger than that from the fMLP-stimulated cells in the absence of CB.

Animals↗

[Effect of phorbol myristate acetate (PMA) on diphosphoinositide (DPI) synthesis in rat mast cell granules].

Rat mast cell granules were obtained by homogenization of highly purified rat mast cells and isolated in a Percoll gradient. DPI synthesis in rat mast cell granules was assayed by measuring the incorporation of 32P from [gamma 32P] ATP into DPI in the absence of exogenous phosphatidylinositol (PI). Lipids were isolated with methanol/chloroform/HC1 and were separated by thin-layer chromatography on oxalic acid impregnated silica gel plates. DPI areas were identified by staining with iodine, scraped and measured for 32P radioactivity. The addition of PMA to the granules caused an increase of DPI synthesis, which can be catalysed by PI kinase. Neither an inactive phorbol ester, 4-alpha-phorbol-12, 13-didecanoate, nor dimethyl sulfoxide (DMSO) used as a solvent for PMA had any effect. The effect of PMA in the DPI synthesis was dose-dependent and maximal effects were observed at 10-100 ng/ml. Dose-response curves of the effects of PMA in DPI synthesis in the granules corresponded to those of other biochemical effects of PMA in rat mast cells, such as mediator release mediated through the activation of protein kinase C. These results suggest that PMA may directly affect PI kinase or indirectly regulate its activity in rat mast cell granules.

1-Phosphatidylinositol 4-Kinase↗

[Polyamines stimulate the phosphorylation of phosphatidylinositol in rat mast cell granules].

Rat mast cell granules were obtained by homogenization of highly purified rat mast cells and isolated in a Percoll gradient. Diphosphoinositide (DPI) synthesis in rat mast cell granules was assayed by measuring the incorporation of 32P from [gamma 32] ATP into DPI in the absence of exogenous phosphatidylinositol (PI). Lipids were isolated with methanol/chloroform/HCl and were separated by thin-layer chromatography on oxalic acid impregnated silica gel plates. DPI areas were identified by staining with iodine, scraped and measured for 32P radioactivity. The addition of polyamines, spermine and spermidine to the granules caused an increase in DPI synthesis, which can be catalyzed by PI kinase. This effect of polyamines on DPI synthesis in the rat mast cell granules was dose-dependent and maximal effects were observed at 1 mM spermine and 10 mM spermidine respectively. When the effect of 1 mM spermine on 32P incorporation into DPI in rat mast cell granules was investigated serially, 32P incorporation into DPI in rat mast cell granules incubated with spermine for 15 min was enhanced significantly (p less than 0.05) compared with that in the granules in the absence of spermine.

Animals↗

[Surgical case of simultaneous triple cancers of the esophagus, stomach and colon].

We report a patient with synchronous triple cancers arising in the digestive tract. It was a combination of esophageal, gastric and colonic cancers; total excision was performed in one operation. Histological study confirmed that each cancer had developed independently. The esophageal cancer was of ulcerated type; histologically it was poorly differentiated squamous cell carcinoma. The gastric and colonic cancers were both of Borrmann II type and well differentiated adenocarcinoma.

Adenocarcinoma↗