Search PubMed⌕ Search

Biomedical subjects

H Horie

Publications and source records attributed to H Horie.

At least 145 records · Page 8Linked to original sources
PubMed1989

Adaptation of cultured mammalian neurons to a hypotonic environment with age-related response.

The response of neurons to osmolal concentration changes has not been well-documented compared to erythrocytes, urinary bladder and epithelial cells. The effects of a hypotonic solution on morphology and electrophysiological functions in cultured dissociated neurons can be precisely studied. From the analysis of video pictures from Nomarski optics, diameters of the cells were seen to increase and then recover to the initial values after the application of a hypotonic solution. The rate of increase of cell size in fetal neurons was 4-5 times faster than in mature neurons. This age-related transient response was accompanied by a change of resting potential and membrane resistance. This transient depolarization and decrease of the resistance corresponded to morphological changes. However, the amplitude of an action potential scarcely changed during the cell membrane expansion. It is plausible that increased membrane tension caused by the membrane expansion might facilitate the opening of the channel. The cell membrane expansion might also increase ionic permeability through the membrane. This may reduce a swollen cell volume to the initial one by diluting their intracellular solute concentration. After this adaptation the cultured neurons were able to survive for a long time and extend processes in the hypotonic environment.

Aging↗
PubMed1989

Immunofluorescence demonstration of neurofilament polypeptide expression in fetal human neurons in culture.

Sensory neurons from 10-week human fetal dorsal root ganglia were dissociated and grown in vitro and immunostained with monoclonal antibodies specific for neurofilament triplet polypeptides (non-phosphorylated 70 kDa peptide, NF-L; phosphorylated 150 kDa peptide, NF-M; and phosphorylated 200 kDa peptide, NF-H). All 3 neurofilament subunits appeared early in neuronal perikarya, but they were demonstrated in neurites at different times of culture. The phosphorylated 150 kDa subunit was the first to be expressed in neurites and was followed first by the phosphorylated 200 kDa subunit, and then by the 70 kDa subunit.

Antibodies, Monoclonal↗
PubMed1989

[Study on follow-up of patients with biopsy-proven breast disease].

Eight hundred forty-one patients with biopsy-proven benign breast disease were followed annually in prospective manner for 1-10 years to analyse breast cancer development at aspect of histologic features, age at entry and mammographic patterns by Wolfe. No association was found between patients who developed cancer and those who did not with respect to the initial histologic features. The rate of breast cancer development in patients in thirties was the highest. The breast cancer development was found most often in less than three years follow-up period. The breast parenchymal patterns at entry related to cancer development. In 10 cancer patients, 8 patients showed DY pattern and 2 showed P2 patterns. The present results demonstrate that the patients with biopsy-proven benign breast disease in thirties, in less than 3 years follow up period and have parenchymal patterns of P2 or DY should be followed carefully.

Adult↗
PubMed1989

[A case of stromal sarcoma of the breast].

A 28-year-old woman with a stromal sarcoma of the breast is reported. By palpation, she had uncovered a tumor in the upper inner quadrant of the right breast. The subsequent physical examination and echographic findings suggested a phyllodes tumor and an excisional biopsy was performed. A pathologic examination revealed the infiltration of spindle cells with a fascicular pattern, a bizarre mitotic configuration and no epithelial component, thus leading to the diagnosis of a stromal sarcoma. The patient then underwent a modified radical mastectomy. A stomal sarcoma of the breast is very rare, and early diagnosis and a curative resection improves the chances of survival.

Adult↗
PubMed1989

[Ewing sarcoma originated from rib in 3-year-old child--a case report].

A 3-year-old girl was admitted to our hospital with a 3-month history of moderate fever, cough and dyspnea. Chest X-ray and C-T scan showed huge mass with high density, occupying right anterior thoracic cavity. Tumor marker including CEA, AFP, NSE in serum and VMA in urine revealed within normal data. Cytological finding obtained by percutaneous fine needle aspiration demonstrated neuroblastoma. 4 days after admission, urgent operation was performed, because of reinforced dyspnea. Huge tumor was successfully dissected, with combined resection of 2nd and 3rd ribs. Pathological diagnosis showed Ewing sarcoma originated from rib. This case is the youngest case of Ewing sarcoma of bone in Japan, and the patient is alive with disease free at the postoperative period of 21 months.

Bone Neoplasms↗
PubMed1989

[Radioimmunoassay of plasma calcitonin gene-related peptide (CGRP) levels in patients with endocrine tumor].

For the purpose of determining the significance of CGRP for endocrine tumors, we attempted to establish CGRP radioimmunoassay (RIA) system and to measure plasma CGRP levels in patients with endocrine tumor. One ml of plasma (EDTA-2K + aprotinin 500.KIE/ml) was applied to Sep-Pak C 18 column, and was eluted by 90% MeOH plus 0.1% TFA. The eluted samples were used for RIA. RIA was performed by two day-one day system (delayed assay). B/F separation was made by two Ab-PEG method. Cross-reactivity of antisera was 0.0025% and below 0.0001% against PTH and calcitonin in human, respectively. The standard curve of CGRP showed a dose response curve. Results of dilution and reproduction tests were excellent. Normal range of serum CGRP was 6.7 +/- 3.0 pg/ml (M +/- SD) and the cut-off level was determined to be 12.7 pg/ml. Plasma CGRP showed 128,323 and 2,010 pg/ml in three preoperative patients with medullary thyroid carcinoma, indicating extremely high levels. On the other hand, plasma CGRP levels increased in 2/7, 2/4, 2/5, and 0/3 in patients with parathyroid adenoma, benign insulinoma, carcinoid and pheochromocytoma, respectively. Correlation between CGRP level and calcitonin levels was significant (r = 0.789) in only 16 patients with medullary thyroid carcinoma. This study suggests that our CGRP RIA system was satisfactory for clinical use and measurement of CGRP may be potentially useful for clearing the pathophysiology of neuroendocrine tumors, although CGRP level was raised in patients with medullary thyroid carcinoma.

Biomarkers, Tumor↗
PubMed1988

Effects of arachidonic acid and the other long-chain fatty acids on the membrane currents in the squid giant axon.

The effects of arachidonic acid and some other long-chain fatty acids on the ionic currents of the voltage-clamped squid giant axon were investigated using intracellular application of the test substances. The effects of these acids, which are usually insoluble in solution, were examined by using alpha-cyclodextrin as a solvent, alpha-cyclodextrin itself had no effect on the excitable membrane. Arachidonic acid mainly suppresses the Na current but has little effect on the K current. These effects are completely reversed after washing with control solution. The concentration required to suppress the peak inward current by 50% (ED50) was 0.18 mM, which was 10 times larger than that of medium-chain fatty acids like 2-decenoic acid. The Hill number was 1.5 for arachidonic acid, which is almost the same value as for medium-chain fatty acids. This means that the mechanisms of the inhibition are similar in both long- and medium-chain fatty acids. When the long-chain fatty acids were compared, the efficacy of suppression of Na current was about the same value for arachidonic acid, docosatetraenoic acid and docosahexaenoic acid. The suppression effects of linoleic acid and linolenic acid on Na currents were one-third of that of arachidonic acid. Oleic acid had a small suppression effect and stearic acid had almost no effect on the Na current. The currents were fitted to equations similar to those proposed by Hodgkin and Huxley (Hodgkin, A.L., Huxley, A.F. (1952) J. Physiol (London) 117:500-544) and the change in the parameters of these equations in the presence of fatty acids were calculated.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Comparison of six different substrata on the plating efficiency, differentiation and survival of human dorsal root ganglion neurons in culture.

We compared six different substrata for their ability to promote attachment, neurite extension and short-term survival of dissociated human fetal dorsal root ganglion neurons. The substrata were laminin, fibronectin, polylysine, type I collagen, a combination of collagen and polylysine, and bare plastic surface. The results show laminin and fibronectin, two important constituents of the extracellular matrix of the nervous system, to be comparable in efficiency and the best substrata for the successful in vitro growth of human fetal dorsal root ganglion neurons. The present study also supports the notion that the development of the nervous system in vivo and in vitro may be critically dependent on the components of the extracellular matrix.

Cells, Cultured↗
PubMed1987

Cell membrane expansion and blockade of action potentials produced by 2-decenoic acid in cultured dorsal root ganglion neurons.

2-Decenoic acid, a fatty acid having 10 carbon atoms, blocks the action potentials of cultured dorsal root ganglion (DRG) neurons and this effect of 2-decenoic acid is reversible. From the analysis of the video pictures from Nomarski optics, relative values of the diameter and the thickness of the neurons increased to 1.06 and 1.14, respectively, when 2.1 mM 2-decenoic acid was applied to the neurons. The relative value of cell surface area, which was calculated from the equation for a spheroid, increased to about 1.20. On the other hand, relative fluorescence intensity of the fluorescent probe F18 (5-(octadecylthiocarbamoylamino)fluorescein) labeled neurons decreased to 0.81, when 2.1 mM 2-decenoic acid was applied to the neurons. This indicates that the relative cell surface area increased to 1.23, a value similar to that calculated from the results of the measurement of cell size. The time course of blocking action potentials after treatment of the fatty acid was similar to that of the cell membrane expansion. These results show that the fatty acid perturbs the cell membrane and expands the cell surface area and this expansion might reduce the opening ability of the Na+-channels in the membrane.

Action Potentials↗
PubMed1987

Effects of fatty acids on membrane currents in the squid giant axon.

The effects of fatty acids on the ionic currents of the voltage-clamped squid giant axon were investigated using intracellular and extracellular application of the test substances. Fatty acids mainly suppress the Na current but have little effect on the K current. These effects are completely reversed after washing with control solution. The concentrations required to suppress the peak inward current by 50% and Hill number were determined for each fatty acid. ED50 decreased about 1/3 for each increase of one carbon atom. The standard free energy was -3.05 kJ mole-1 for CH2. The Hill number was 1.58 for 2-decenoic acid. The suppression effect of the fatty acids depends on the number of carbon atoms in the compounds and their chemical structure. Suppression of the Na current was clearly observed when the number of carbon atoms exceeded eight. When fatty acids of the same chain length were compared, 2-decenoic acid had strong inhibitory activity, but sebacic acid had no effect at all on the Na channel. The currents were fitted to equations similar to those proposed by Hodgkin and Huxley (J. Physiol. (London) 117:500-544, 1952) and the changes in the parameters of these equations in the presence of fatty acids were calculated. The curve of the steady-state activation parameter (m infinity) for the Na current against membrane potential and the time constant of activation (tau m) were shifted 20 mV in a depolarizing direction by the application of fatty acids. The time constant for inactivation (tau h) was almost no change by application of the fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Abnormal calcium handling by perifused pancreatic islets from neonatal streptozotocin diabetic model rats.

To elucidate the mechanism of impaired insulin release in case of non-insulin-dependent diabetes (NIDDM), we investigated insulin release and 45Ca++ efflux from perifused islets obtained from neonatal streptozotocin diabetic model rats. The model rats were prepared by the intraperitoneal administration of 65 mg/kg streptozotocin (STZ) to neonatal males. Rats treated with STZ did not differ from controls in body weight from 1 week to 16 weeks. The model rats had significant hyperglycemia both in the fasting state and after intraperitoneal administration of 2 g/kg glucose. Although the diameter of the islets from the model rats was not significantly different from that of controls, immunoreactivity to anti-insulin was slightly diminished, and degranulation was slightly observed in B-cells. Insulin content was reduced to 45.6% of the control. Insulin release from the perifused islets of STZ-treated rats responded little to 16.7 mmol/L glucose, but normally to 20 mmol/L arginine in the presence of 5.5 mmol/L glucose. In experiments to test the 45Ca++ efflux from the perifused islets prelabeled with 45Ca++, a rise of 45Ca++ efflux concomitant with the second phase of insulin release from the islets of the model rats was inhibited although a sharp increase of 45Ca++ efflux concomitant with the first phase of insulin release was maintained. 45Ca++ uptake for 30 minutes was reduced in the islets from the model rats in the basal and stimulated state of insulin secretion although the incremental 45Ca++ uptake was similar. It is possible that the abnormal calcium handling in pancreatic B-cells may be one of the causes of defect in insulin release in our model rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Splenic rupture in acute megakaryoblastic leukemia.

A 43-year-old man with pancytopenia and circulating blast cells was found to have acute megakaryoblastic leukemia. Bone marrow biopsy disclosed reticulin fibrosis with infiltration of blast cells. Cytogenic study showed 48,XY,+15,+18. The megakaryocytic origin of blast cells was confirmed by platelet peroxidase reaction at ultrastructural level. The spleen which had not been felt on admission increased in size rapidly and ruptured abruptly. This appears to be the first reported case of a splenic rupture associated with acute megakaryoblastic leukemia.

Acute Disease↗