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Biomedical subjects

K Furuya

Publications and source records attributed to K Furuya.

At least 199 records · Page 11Linked to original sources
PubMed1993

Proliferation-associated increase in sensitivity of mammary epithelial cells to inositol-1,4,5-trisphosphate.

Injection of D-myo-inositol-1,4,5-trisphosphate (IP3) was found to induce a transient increase of intracellular Ca2+ concentration in cancerous mammary cells (MMT060562) and in normal mammary cells treated with epidermal growth factor. Responses to injection of either D-myo-inositol-1,4-bisphosphate (IP2) or D-myo-inositol-1,3,4,5-tetrakisphosphate (IP4) were small or absent. Furthermore, normal mammary cells cultivated with low-protein serum replacement alone or in the presence of differentiation-inducing hormones (insulin + cortisol + prolactin) were less sensitive to IP3. Thapsigargin induced a transient increase of Ca2+ due to the release of Ca2+ from an intracellular pool. There was no difference in the peak heights of the thapsigargin-induced Ca2+ increase when mammary cells were cultivated in the presence or absence of epidermal growth factor or insulin + cortisol + prolactin. These findings suggest that the releasable intracellular Ca2+ pool remained unchanged whereas sensitivity to IP3 increases during the proliferation stage. Mechanical stimulus of a mammary cell induces an increase of intracellular Ca2+ in the stimulated cell. A certain stimulating factor is released from the mechanically stimulated cell into the extracellular space, and it induces an increase of Ca2+ in surrounding cells. In contrast, the IP3-induced Ca2+ increase in both cancerous and epidermal growth factor-treated normal mammary cells did not spread to adjacent cells. Therefore, increase of Ca2+ is not sufficient to account for the release of stimulating substances from mammary cells in the mechanically-induced spreading response.

Animals↗
PubMed1993

Biology and neurobiology of Borna disease viruses (BDV), defined by antibodies, neutralizability and their pathogenic potential.

Borna disease viruses (BDV) isolated from more than 20 naturally infected horses, 2 sheep and a possible feline isolate were included in these studies. Most of these wild-type viruses were grown in rabbit cells. Specifically rabbit-adapted viruses establish persistent infection in immortalized cell lines of various animal species. Brain-, tissue culture-, and cell-free released viruses could all be neutralized with antibodies from naturally and experimentally infected animals (horse; hamster, rat, rabbit, mouse, and chicken), with highest titres in birds. Splenectomized rabbits, which were subsequently infected with BDV, efficiently produced high titres of neutralizing antibodies. All of the neutralizing sera and cerebrospinal fluids from infected animals inhibited tissue culture spread of BDV. Experimental infection and hyperimmunization induced antibodies directed against the major components of the soluble antigen (60, 40/38, 25 and 14.5 kD proteins). Analysis of the s-antigen complex with these sera and 6 stable monoclonal antibodies revealed that it consists of 40/38 and 25 kD proteins. Although each of these antibodies detected intracellular virus-specific structures they did not recognize outer plasma membrane antigens, showed no cross-reactivity, and had no neutralizing capacity. Unifying pathogenetic concepts of this neurotropic virus and its structural elements are discussed.

Animals↗
PubMed1993

Pseudarthrosis and delayed union after anterior cervical fusion.

Anterior cervical spine fusion was carried out on 443 cases between 1965 and 1988 with pseudarthrosis or delayed union in 15 (3.4%). The causes of these complications were malalignment and faulty postoperative care. Symptoms resulted from abnormal mobility, cord compression due to posterior slip or rotation of the upper vertebral body, kyphotic deformity or a problem at the adjacent level. Four out 5 cases with symptoms recovered successfully after a second operation.

Adult↗
PubMed1993

Characteristics of cultured subepithelial fibroblasts of rat duodenal villi.

Subepithelial fibroblasts, which form a cellular network beneath the epithelium of rat intestinal villi, were cultured, and their morphological characteristics were examined. These fibroblasts, which migrated from epithelium-free villi (isolated primarily from duodenum) were flat in shape after 2 days of culture. The flat cells, each resembling a maple leaf, were rich in bundles of microfilaments, and were connected to each other by a few small gap junctions, ascertained from freeze-fracture and dye-coupling experiments. The morphology of the flat cells changed to a stellate form, with thin processes, within 30 min-1 h of reducing the serum concentration and adding dibutyryl cyclic AMP (dBcAMP), forskolin, and cholera toxin. Upon removal of dBcAMP and addition of fetal calf serum, the cells rapidly reassumed their original flat shape. Cells that were stellate in the presence of dBcAMP reassumed a flat morphology within several minutes after the addition of endothelin-1. This conversion occurred with or without extracellular Ca2+. An accompanying rearrangement of the cytoskeleton during shape conversion was observed by fluorescence immunohistochemistry.

Actins↗
PubMed1993

Bronchial atresia: report of a case and review of the literature.

We report herein an unusual presentation of bronchial atresia in a 28-year-old woman, in whom hyperlucency of the ventral segment, distal to a right extrahilar mass found on a routine chest X-ray, was not recognized. Atresia of the medial branch of the ventral segmental bronchus (B3b) with mucoid impaction in the dilated bronchus was finally disclosed by a right upper lobectomy. The patient had been asymptomatic, and physical examination demonstrated no abnormal findings such as decreased breathing sounds over the affected lung. Localized hyperlucency and a mass are the characteristic radiographic features of bronchial atresia. In the present case, however, hyperlucency distal to the mass, which was retrospectively evident on a computed tomogram of the chest, was not recognized. The preoperative diagnosis was also made difficult by the fact that the atresia was located on a subsequential branch (B3b) of the ventral segmental bronchus of the right upper lobe. Since computed tomography and magnetic resonance imaging are able to make an accurate diagnosis of bronchial atresia possible, surgery is often not indicated for asymptomatic patients. Moreover, although surgical intervention is required for patients with complications such as encroachment of normal pulmonary tissue or infection, resection should be as limited as possible to preserve normal lung tissue.

Adult↗
PubMed1993

Spontaneous calcium oscillations and mechanically and chemically induced calcium responses in mammary epithelial cells.

Changes of intracellular calcium activity (Ca2+i) in mouse mammary epithelial cells in primary culture (normal) and in an established cell line (MMT060562, cancerous) were investigated by microfluorometry and image analysis of fura-2 fluorescence. In both types of cells, some populations exhibited occasional Ca2+i oscillations with a period of 50-160 s. Slight mechanical stimulation of a cell with a fine glass pipette induced a Ca2+i increase, which spread from the stimulated cell to the surrounding cells with a speed of 7-12 microns/s. ATP (> 1 mumol/l) and ADP, but not AMP induced a Ca2+i increase in both cell types. Bradykinin was highly effective (> 10 nmol/l) only in the cancerous mammary epithelial cells. In Ca(2+)-free solution, all these Ca2+i responses remained unchanged at the first application, and decreased abruptly at the second trial. La3+ (> 0.5 mmol/l) suppressed the response to ATP but not the response to bradykinin. Addition of extracellular Mn2+ rapidly quenched the fura-2 fluorescence in the cell even in a non-stimulated state. Influx of Mn2+ did not increase during Ca2+i responses. These results indicate that the sources of Ca2+i responses in mammary epithelial cells are intracellular stores, which exchange Ca2+ with the extracellular medium.

Adenosine Triphosphate↗
PubMed1993

Brain stem haemorrhage during transsphenoidal surgery. Possible risk of the manoeuvre of increasing the endexpiratory pressure in a case of pituitary adenoma associated with dural arteriovenous malformation. Case report.

The authors report a case of pituitary adenoma associated with dural arteriovenous malformation (AVM), which caused brain stem haemorrhage during transsphenoidal surgery. The manoeuvre of increasing the endexpiratory pressure in order to push the suprasellar component of the adenoma down to the sella turcica could be the reason of this bleeding. The authors therefore recommend that in cases of such a combination any manoeuvres which are likely to increase the intracranial venous pressure or otherwise affect the intracranial pressure, are avoided. The dural AVM spontaneously regressed after haemorrhage.

Adenoma↗
PubMed1993

Solubility of nickel oxide particles in various solutions and rat alveolar macrophages.

The solubility of five types of commercial nickel oxide particles was determined in different types of solutions, including distilled water, physiological saline, buffered saline, and tissue-culture medium, in order to estimate their solubility in the human respiratory tract. In addition, we examined the solubility of the two types of particles that were the most and least soluble particles of the above five types of nickel oxide, in rat alveolar macrophages cultured in vitro. The solubility of the nickel oxide particles in these solutions varied remarkably with their types, suggesting that, even though they are called as "nickel oxide," their solubilities are different among the manufacturer and the product lot. Their solubilities were also influenced by the types of solution and the existence of carbon dioxide in the atmosphere. The solubility of nickel oxide particles in the alveolar macrophages was significantly larger than that observed in the culture medium without macrophages, but smaller than that observed in the distilled water. These results suggest that the actual solubility of nickel oxide particles in the respiratory tract may be difficult to estimate by the conventional solubility analysis method using distilled water, and that the enhancement of particle dissolution by the alveolar macrophages and the depression of particle solubility by the coexisting salt and carbon dioxide should be taken into consideration for the accurate estimation.

Animals↗
PubMed1993

Stress hormone responses to major intra-abdominal surgery during and immediately after sevoflurane-nitrous oxide anaesthesia in elderly patients.

We studied the responses of plasma epinephrine, norepinephrine, adrenocorticotropic hormone (ACTH), cortisol, and antidiuretic hormone (ADH) during and immediately after sevoflurane-nitrous oxide anaesthesia supplemented with vecuronium in seven elderly patients (mean 76.6 +/- 1.7 SEM) who underwent major intra-abdominal surgery. The plasma concentrations of norepinephrine, ACTH, cortisol, and ADH increased in response to surgical procedures (P < 0.05). The plasma concentration of ADH increased to a peak concentration of 189.1 +/- 20.7 pg.ml-1 30 min after skin incision (P < 0.05). The plasma concentrations of epinephrine, norepinephrine, ACTH, and cortisol increased to peak concentrations of 408.6 +/- 135.5 pg.ml-1, 635.7 +/- 167.8 pg.ml-1, 222.6 +/- 48.0 pg.ml-1, and 113.6 +/- 67.5 micrograms.dl-1, respectively immediately after tracheal extubation (P < 0.05). We conclude that, in the elderly patients, the responses of stress hormones to major intra-abdominal surgery were preserved during sevoflurane-nitrous oxide anaesthesia sufficient to prevent increases in arterial pressure and heart rate. The strongest responses of epinephrine, norepinephrine, ACTH, and cortisol were elicited immediately after tracheal extubation.

Abdomen↗
PubMed1993

An analysis of failures in primary cervical anterior spinal cord decompression and fusion.

Recently, postoperative results of cervical spondylosis, disc herniation, and ossification of the posterior longitudinal ligament (OPLL) after anterior cervical surgeries have improved. However, occasional unsatisfactory cases needing a second operation remain. We analyzed and developed strategies for multioperated neck (MON) cases; all patients had two operations. From 1965 to 1988, 443 cervical anterior surgeries were performed in our hospitals; 53 (12.0%) of these patients needed second operations. These MON cases were classified by the following causes: pseudarthrosis, graft fracture, insufficient decompression, misdiagnosis, and adjacent disc problems. These groups were analyzed, and the resulting surgical strategies, including indications and techniques of anterior surgery, are described.

Adolescent↗
PubMed1993

Evaluation of cervical diskography in pain origin and provocation.

The purpose of this article is to analyze the role of cervical diskography as a diagnostic method via reproduced pain. A nonionic contrast medium (Iohexol) that does not harm normal tissue was used in this series to prevent false-positive provocative pain. One hundred forty-four patients (128 with cervical spondylotic myelopathy, eight with cervical spondylotic radiculopathy, and eight with cervical spondylotic amyotrophy) were studied. Among 72 patients in the symptomatic neck pain group who complained of neck pain before diskography, 65% showed reproduced pain. However, in the control group (neurologic symptoms only) 50% of the patients complained of provocative neck pain during dye injection. These results demonstrated that this provocation technique appeared unreliable for diagnosing symptomatic disk levels.

Adult↗
PubMed1993

Estradiol does not influence myocardial superoxide dismutase activity in rabbits.

The influence of sex steroids on myocardial superoxide dismutase (SOD) activity was evaluated in rabbits. No sex differences in SOD activity were observed in male and female rabbits. Castration did not lead to any changes in SOD activity in either sex. Graded doses of estradiol that produced graded increases in uterotropic effect failed to produce any change in myocardial SOD activity. Results indicate that the beneficial effect of estrogen on cardiovascular disease and the sex differences in incidence of cardiovascular morbidity cannot be explained on the basis of a direct action of estradiol on myocardial SOD activity.

Animals↗
PubMed1993

Adenoendocrine cell carcinoma of the gallbladder: a histochemical and immunohistochemical study.

A case of adenoendocrine cell carcinoma of the gallbladder with adenomucous cells and neuroendocrine cells is reported. A histochemical and immunohistochemical study revealed that the primary tumor in the gallbladder was composed of mucus-secreting and/or argyrophil cells. Furthermore, the tumor showed a positive reaction to carcinoembryonic antigen (CEA) in all tumor cells, to chromogranin A and cytokeratin in many tumor cells, to endocrine granule constituent (EGC) in some tumor cells, and to serotonin and somatostatin in a few tumor cells. In addition, a few mucous cells showed argyrophilia and EGC-positivity in their cytoplasms. This case suggests that the adenoendocrine cell tumor is derived from endodermal stem cells as a result of bidirectional (exocrine and endocrine) differentiation.

Adenocarcinoma↗
PubMed1993

Correlation of GM-CSF mRNA in bronchoalveolar fluid with indices of clinical activity in sarcoidosis.

BACKGROUND: Granulocyte-macrophage colony stimulating factor (GM-CSF) has several proinflammatory effects, some of which potentially favour granuloma formation. Its mRNA expression by the inflammatory cells recovered from lungs of patients with pulmonary sarcoidosis has been previously reported. In this study an association between GM-CSF expression and manifestations of the disease was explored. METHODS: GM-CSF mRNA was detected by reverse transcription polymerase chain reaction in the cells of bronchoalveolar lavage (BAL) fluid of 20 patients with pulmonary sarcoidosis. RESULTS: GM-CSF mRNA expression was positive in 15 of 20 patients with sarcoidosis. Fourteen of the 15 patients with positive mRNA expression had worsening or unchanged disease during the year preceding this study, on the basis of radiographic or physical findings, or both, whereas all five "negative" patients were judged to be improving. Similarly, serum levels of angiotensin converting enzyme, the proportion of lymphocytes in BAL fluid, and the CD4+/CD8+ ratio of lymphocytes in BAL fluid were significantly higher in the positive patients. CONCLUSIONS: There was an association between the presence of GM-CSF mRNA in the cells in BAL fluid and other indices of disease activity in sarcoidosis.

Adult↗
PubMed1993

Release of tumor necrosis factor-alpha from human alveolar macrophages is decreased in smokers.

It is known that smoking affects the development and maintenance of certain types of granulomatous lung diseases. To explore this mechanism(s), we measured tumor necrosis factor (TNF)-alpha concentrations in the culture supernatants of lipopolysaccharide (LPS)-stimulated alveolar macrophages (AMs) in 13 healthy nonsmokers, 13 healthy smokers, 13 nonsmoking sarcoid patients, and 16 smoking sarcoid patients. We found that the capacity of smokers' AMs to release TNF-alpha was significantly decreased both in the normal and sarcoid groups. We also confirmed the previous observation that there was an exaggerated TNF release in patients with pulmonary sarcoidosis. These results indicate a significant role of TNF-alpha in the pathogenetic mechanisms of pulmonary sarcoidosis and suggest the possible involvement of TNF in the mechanisms by which smoking modulates local immune phenomena.

Adult↗
PubMed1993

Isolation and identification of a cardioactive peptide from Tenebrio molitor and Spodoptera eridania.

We isolated several cardioactive peptides from extracts of whole heads of the mealworm, Tenebrio molitor, and the southern armyworm, Spodoptera eridania, using a semi-isolated heart of Manduca sexta for bioassay. We have now isolated from each species the peptide with the strongest effect on rate of contraction of the heart. The peptides were identified using micro Edman sequencing and mass spectrometric methods. This cardioactive peptide has the same primary structure from both species: Pro-Phe-Cys-Asn-Ala-Phe-Thr-Gly-Cys-NH2, a cyclic nonapeptide which is identical to crustacean cardioactive peptide (CCAP) originally isolated from the shore crab, Carcinus maenas, and subsequently isolated from Locusta migratoria and Manduca sexta. This is additional evidence that CCAP has widespread occurrence in arthropoda.

Amino Acid Sequence↗
PubMed1993

Aquastatin A, an inhibitor of mammalian adenosine triphosphatases from Fusarium aquaeductuum. Taxonomy, fermentation, isolation, structure determination and biological properties.

A new inhibitor of mammalian adenosine triphosphatases, designated aquastatin A, has been isolated from a fungus identified as Fusarium aquaeductuum. The structure of this compound has been determined by MS and NMR analyses. It inhibits Na+/K(+)-ATPase with an IC50 value of 7.1 microM, and H+/K(+)-ATPase with an apparent IC50 value of 6.2 microM.

Adenosine Triphosphatases↗