Search PubMed⌕ Search

Biomedical subjects

T Hirose

Publications and source records attributed to T Hirose.

At least 685 records · Page 38Linked to original sources
PubMed1986

Primary structure of the alpha-subunit of bovine adenylate cyclase-stimulating G-protein deduced from the cDNA sequence.

The primary structure of the alpha-subunit of the adenylate cyclase-stimulating G-protein (Gs) has been deduced from the nucleotide sequence of cloned DNA complementary to the bovine cerebral mRNA encoding the polypeptide. Comparison of the amino acid sequences of the alpha-subunits of Gs and transducin reveals that some of the highly conserved regions show sequence homology with elongation factor-Tu and ras p21 proteins and correspond to functional regions of guanine nucleotide-binding proteins.

Adenylyl Cyclases↗
PubMed1986

Self-retaining iris speculum for open-sky vitrectomy.

We have designed a self-retaining iris speculum for use in open-sky vitrectomy. This speculum retracts the iris away from the central field and thus allows the surgeon better visibility and less reliance on an assistant's help for retraction. The possibility of iris laceration and dialysis with excessive bleeding, as sometimes seen with other forms of iris retraction, can be prevented.

Equipment Design↗
PubMed1986

Four-port bimanual vitrectomy.

A further subdivision of functions during vitrectomy surgery has been enabled. By means of a separate, suture-secured fiberoptic endoilluminator and a modified infusion cannula located in the inferior quadrants, two superior sclerotomies are kept free for the use of a variety of simple and complex instruments, alone or in combination. Included among these are vitreous scissors, forceps, picks, spatulas, diathermy probes, and endophotocoagulators.

Humans↗
PubMed1986

Vitreoretinal dissection set.

We developed and evaluated a vitreoretinal dissection set consisting of six microspatulas, a specially designed micro-olive tip, an internal drainage cannula, and a master handle. The microspatulas, which have a spear-headed shape with blunt edges and flat, smooth surfaces, offer a range of angulation from 60 degrees to 160 degrees as well as options for front, back, or tip opening for irrigation or aspiration purposes. All parts can be used through conventional 20-guage or 19-guage sclerostomies, and they all fit on the same handle as well as on any Luer lock system. This set allows for mechanical and/or hydraulic dissection, membrane engagement by suction, and simultaneous use of probe with scissors or forceps. It has been proved safe and effective in more than 100 vitrectomies, including cases of diabetic tractional detachment, proliferative vitreoretinopathy, retrolental fibroplasia, and macular pucker.

Humans↗
PubMed1986

Ultrastructural localization of S-100 protein in neurofibroma.

The nature of the cells in neurofibromas was studied by electron microscopy and immunoelectron-microscopic examination of S-100 protein. Ultrastructurally, all five neurofibromas studied were found to be composed of Schwann cells, perineurial cells, and intermediate cells, which had features of both perineurial cells and fibroblasts. The Schwann cells had complex, branched cytoplasmic processes and a continuous basal lamina. The perineurial cells were distinguishable from Schwann cells by the presence of numerous pinocytotic vesicles, unbranched slender cytoplasmic processes and a discontinuous basal lamina. The intermediate cells had no basal lamina, but were topographically related to Schwann cells and had a similar fine structure to that of perineurial cells. Thus, they seemed to be modified neoplastic perineurial cells. Immunoelectron-microscopic studies showed the presence of cells with and without S-100 protein in the neurofibromas: cells with S-100 protein resembled Schwann cells ultrastructurally, and those without S-100 protein were perineurial and intermediate cells. Some Schwann cells with S-100 protein in one neurofibroma had numerous pinocytotic vesicles characteristic of perineurial cells, suggesting that Schwann cells and perineurial cells are functional variants of the same cell type. Thus this study showed that neurofibromas were composed of Schwann cells with S-100 protein and perineurial and intermediate cells, including so-called endoneurial fibroblasts, without S-100 protein. Morphological and functional transition seems to occur between Schwann cells and perineurial cells, and between perineurial cells and intermediate cells.

Adult↗
PubMed1986

The complete nucleotide sequence of the group II RNA coliphage GA.

The complete nucleotide sequence of the RNA coliphage GA, a group II phage, is presented. The entire genome comprises 3466 bases. Three large open reading frames were identified, which correspond to the maturation protein gene (390 amino acids), the coat protein gene (129 amino acids) and the replicase beta-subunit protein gene (531 amino acids). In addition, untranslated regions occur at the 5' (135 bases) and 3' (122 bases) ends of the molecule. Two intercistronic untranslated regions occur between the cistrons for the maturation and coat proteins, and between the coat and beta-subunit proteins. We have compared the nucleotide sequence of GA RNA with the published sequence of MS2 RNA, and show that they are related. The comparative structures of two important regulatory regions are presented; the coat protein binding site which is involved in translational repression of the replicase beta-subunit protein gene, and a hairpin in a region proximal to the lysis protein gene.

Base Sequence↗
PubMed1986

Ultrastructural study on an appendiceal carcinoid tumor showing intra-nerve fiber growth.

Ultrastructural and immunohistochemical studies on an appendiceal carcinoid tumor in a 53-year-old man disclosed an intimate association of nerves and tumor cells. Electron microscopy revealed that the tumor nests were composed of neurosecretory cells containing neurosecretory granules and peripherally-located Schwann cells encasing axons. Some tumor nests were continuous with nerve fibers invested in the common basal lamina. These findings suggest that at least some carcinoid tumors of the appendix show intra-nerve fiber growth, and that the neurosecretory cells might be present in the nerve fibers from the beginning or infiltrated into the nerve fibers at a very early stage of neoplastic transformation.

Appendiceal Neoplasms↗
PubMed1986

Objective evaluation of binocular function with pattern reversal VER. III. Effect of stimulus size and localization.

The effect of central and peripheral stimulus field on monocular and binocular amplitude and binocular summation of the pattern reversal VER were investigated. When the central stimulus field size was smaller than 2.0 degrees X 2.0 degrees, there was no significant difference between the amplitudes of the monocular and binocular VER, but when it was equal to or larger than 2.4 degrees, the binocular VER amplitude was significantly larger than the monocular. The value of the binocular summation was highest at the central stimulus field size of 4.0 degrees X 4.0 degrees; at larger sizes, there were no significant changes in the value. Use of a central stimulus field size larger than 2.4 degrees X 2.4 degrees was therefore considered a prerequisite for the effective assessment of visual function, especially binocular function using the pattern reversal VER. Regarding the effect of peripheral stimulus field, both the monocular and binocular VER, but particularly the latter, were found to be sensitive to the central scotoma produced by covering the center of the full-field stimulus. The value of the binocular summation showed a significant reduction with the small central scotoma. We concluded that the pattern reversal VER is very sensitive to a central scotoma and that binocular function is mediated mainly through the central part of the stimulus field.

Adult↗
PubMed1986

Objective evaluation of binocular function using the pattern reversal visual evoked response. II. Effect of mean luminosity.

The effect of mean luminosity change on pattern reversal visual evoked response (VER), especially monocular VER, binocular VER and binocular summation, was studied. The mean luminosity level was changed with the use of neutral density filters. When mean luminosity level was decreased binocularly, binocular and monocular VER amplitudes decreased and binocular summation increased, reaching its peak at a luminosity of -0.3 log foot-lambert. When mean luminosity was changed monocularly and the interocular luminosity difference was larger than 0.6 log unit, the binocular VER became almost equal to or smaller than the monocular VER. In dim luminosity, the binocular system functioned better than the monocular system. Even a slight luminosity difference between the two eyes could disturb the binocular system.

Adult↗
PubMed1986

H1 action of histamine on aldosterone and cortisol secretion by perfused dog adrenal.

The left adrenal of hypophysectomized-nephrectomized dogs was perfused in situ with artificial medium equilibrated with 95% O2-5% CO2. Repeated secretory responses of aldosterone to ACTH and histamine were almost reproducible during 2 h of perfusion, but those of cortisol and corticosterone gradually reduced. The secretion of aldosterone in response to histamine markedly increased at 1 microM and those of cortisol and corticosterone significantly increased at 1 and 10 microM, respectively. The secretory response of aldosterone to 10 microM histamine was comparable with that to 300 microU/ml ACTH, but the secretory responses of cortisol and corticosterone to 10 microM histamine were very much lower than those to 1 microU/ml ACTH. The secretory responses of these three steroids to 10 microM histamine were almost completely depressed by continuous administration of 10 microM pyrilamine maleate, but not abolished by that of 100 microM metiamide. The secretory responses of these three steroids to 10 microM histamine were slightly depressed by continuous infusion of 10 microM methysergide maleate. These results suggest that histamine at pathophysiological concentrations stimulates the secretion of aldosterone markedly, and those of cortisol and corticosterone slightly, via an H1 receptor of adrenocortical cells in the dog.

Adrenal Glands↗
PubMed1986

Analysis of thyroglobulin antibody synthesis by cultured peripheral blood lymphocytes from patients with Hashimoto's thyroiditis using biotin-avidin solid phase enzyme immuno-assay.

The influence of bovine thyroglobulin (Tg) and/or staphylococcus aureus cowan I (SAC) on Tg antibody synthesis has been studied using cultures of 8 Hashimoto's and 5 normal peripheral blood lymphocytes (PBL). The detection of Tg antibody in the culture supernatants was performed by sensitive biotin-avidin solid phase enzyme immunoassay. By using this technique, we were able to detect small amounts of Tg antibody synthesized by cultured Hashimoto's PBL responsive to bovine Tg and/or SAC; PBL from three out of eight patients produced increased levels of Tg antibody in the presence of 0.02 microgram/ml bovine Tg. On the other hand, PBL from two other cases among them which were unresponsive to bovine Tg alone became responsive to bovine Tg following simultaneous stimulation with SAC. PBL from the other three cases failed to respond to bovine Tg or simultaneous stimulation with bovine Tg and SAC. The former five patients had serum Tg tanned red cell hemagglutination (TGHA) titers greater than 1:409,600 except in one case and the latter had serum TGHA titers less than 1:12,800. These results indicated the presence of the different functional stages of B cells to produce Tg antibody in the circulation of Hashimoto's patients and suggested that sufficient number of lymphocytes responsive to bovine Tg are present in the circulation of Hashimoto's patients with high titers of serum TGHA.

Adult↗
PubMed1986

Quantitative assessment of microvascular permeability in endotoxin-induced lung injury in anaesthetized dogs.

We quantitatively assessed the change of pulmonary microvascular permeability following E. coli endotoxin infusion (1 mg/kg) in anaesthetized dogs. We used mathematical analysis to estimate membrane parameters from lung lymph data. Lung lymph was collected from the afferent lymphatic connecting to the left tracheobronchial lymph node whose lymph could be considered to represent an average sample of lung tissue fluid. To separate the effects of changes in the driving pressures and surface area on lymph fluid and protein flux from those in membrane permeability, lymph flow (Jv) was increased greater than 6 times baseline by left atrial pressure (Pla) elevation until lymph protein concentration (CL) approached to a constant value independent of Jv. Membrane parameters for plasma total protein, i.e., osmotic reflection coefficient (sigma d), solvent-drag reflection coefficient (sigma f), permeability surface area product (PS), filtration coefficient (Kfc), were calculated from lung lymphatic data in control (Pla elevation alone (n = 10), and endotoxin group (n = 7). Among these parameters, osmotic reflection coefficient (sigma d) decreased significantly to 0.61 in endotoxin group from the value of 0.71 in control group. This result indicates a moderate increase in pulmonary microvascular permeability following E. coli endotoxin infusion. However, there was no significant difference in the other membrane parameters (sigma f, PS, Kfc) between control and endotoxin group. Based on these results, we conclude that sigma d could quantitatively represent the moderate change of the microvascular permeability in endotoxin-induced lung injury in anaesthetized dogs.

Animals↗
PubMed1986

Tapetoretinal degeneration associated with multisystem abnormalities. A case report.

Tapetoretinal degeneration is not infrequently associated with other systemic abnormalities. The authors have examined an 11-year-old girl with severe pigmentary degeneration of the retina associated with severe musculoskeletal abnormalities, growth failure, recurrent respiratory problems, sensorineural hearing loss, and mental retardation. To the best of their knowledge, this constellation of features has not been described previously and probably represents a new clinical entity.

Abnormalities, Multiple↗
PubMed1986

[Dynamic changes in estrogen receptor levels in the cell cycle of human endometrial adenocarcinoma studied by flow cytometry].

Normal endometrial cells and endometrial adenocarcinoma cells were doubly stained with 1-(N)-fluoresceinyl estrone thiosemicarbazone (17-FE) and propidium iodide and the contents of estrogen receptor (ER) and nucleic acids in a single cell were measured by flow cytometry to clarify the changes in ER levels in the cell cycle. In HHUA cells, established from a well differentiated endometrial adenocarcinoma, used as the ER positive tumor model, the cytoplasmic ER (cER) level increased 1.40 times in the S phase and nuclear ER (nER) level increased 1.65 times in the G2/M phase compared with the levels in the G1 phase. In normal endometrial cells, nER content gradually increased from the early proliferative phase to the ovulatory phase with 2.86 +/- 1.12 times higher levels in the G2/M phase than those in the G0G1 phase and remained high until the mid-secretory phase. Human endometrial adenocarcinoma could be classified into 3 types based on nER levels in G1 and G2/M phases; 1) adenocarcinoma with nER accumulation in G2/M phase as in normal proliferative endometrial cells, 2) adenocarcinoma with nER but with failure of nER accumulation in G2/M phase, suggesting acceptor deficiency, and 3) adenocarcinoma with no nER, suggesting a lack of cER and/or acceptor. These results suggest that cell cycle specific nuclear accumulation of ER, especially in the G2/M phase, is principally related to estrogen dependent proliferation of normal and neoplastic cells.

Adenocarcinoma↗
PubMed1986

[Inflammatory fibrous histiocytoma of the retroperitoneum].

A 64-year-old man with the chief complaint of abdominal fullness was hospitalized on the suspicion of pancreatic tumor. The tumor was thought to be a pancreatic or retroperitoneal tumor, based on examinations of ultrasonography and CT scan of the upper abdomen, angiography of abdominal arteries, and ERCP. Laparotomy revealed that the tumor was inoperable inflammatory fibrous histiocytoma. Combined anti-cancer chemotherapy with doxorubicin, cyclophosphamide, and vincristine induced partial response. The duration of response was six months, and the patient died of tumor growth 18 months after the initial diagnosis.

Angiography↗