Biomedical subjects

A Furuya

Publications and source records attributed to A Furuya.

At least 37 records · Page 2Linked to original sources

PubMed1998

High frequency of fibroblast growth factor (FGF) 8 expression in clinical prostate cancers and breast tissues, immunohistochemically demonstrated by a newly established neutralizing monoclonal antibody against FGF 8.

Fibroblast growth factor (FGF) 8, also known as androgen-induced growth factor, was originally isolated from an androgen-dependent mouse mammary Shionogi carcinoma SC-3 cell line, in which it was shown to have androgen-regulated properties. We previously demonstrated that Fgf 8 transcripts were detected in several human prostate and breast cancer cell lines and that recombinant FGF 8 was mitogenic to an androgen-sensitive prostate cancer LNCaP cell line. In this study, to characterize the roles of FGF 8 in clinical hormone-responsive cancers, we established a monoclonal antibody against FGF 8. In Western blots, this antibody specifically interacted with a FGF 8b isoform that was identical between mouse and human but was not identical to other murine 8a and 8c isoforms. In a cell growth assay using SC-3 cells, the newly established anti-FGF 8 antibody blocked androgen- and FGF 8-stimulated growth but not basic FGF-stimulated growth. Immunohistochemical analyses by use of the established anti-FGF 8 antibody demonstrated that FGF 8 was frequently expressed in human prostate cancers, appearing in 40 of 43 cases (93%), whereas both prostatic hyperplasia specimens and normal prostate tissues included in biopsy specimens were negative for FGF 8 expression. On the other hand, FGF 8 was detected in normal ductal and lobular epithelial cells in breast tissues. FGF 8 was also frequently expressed in various breast diseases, including fibroadenomas (5 of 5 cases, 100%), intraductal papillomas (3 of 3 cases, 100%), ductal hyperplasias (3 of 6 cases, 50%), and breast cancers (8 of 12 cases, 67%). Androgen receptors were also immunohistochemically detected in FGF 8-positive prostate cancers (40 of 40 cases, 100%) and FGF 8-positive breast diseases (17 of 19 cases, 89%). These findings strongly suggest that FGF 8 is involved in hormone-related tumorigenesis of the prostate and breast.

Animals↗

PubMed1998

Cellular localization and expression of template-activating factor I in different cell types.

Template-activating factors I (TAF-I) alpha and beta have been identified as chromatin remodeling factors from human HeLa cells. TAF-I beta corresponds to the protein encoded by the set gene, which was found in an acute undifferentiated leukemia as a fusion version with the can gene via chromosomal translocation. To determine the localization of TAF-I, we raised both polyclonal and monoclonal antibodies against TAF-I. The proteins that react to the antibodies are present not only in human cells but also in mouse, frog, insect, and yeast cells. The mouse TAF-I homologue is ubiquitous in a variety of tissue cells, including liver, kidney, spleen, lung, heart, and brain. It is of interest that the amounts of TAF-I alpha and beta vary among hemopoietic cells and some specific cell types do not contain TAF-I alpha. The level of the TAF-I proteins does not change significantly during the cell cycle progression in either HeLa cells synchronized with an excess concentration of thymidine or NIH 3T3 cells released from the serum-depleted state. TAF-I is predominantly located in nuclei, while TAF-I that is devoid of its acidic region, the region which is essential for the TAF-I activity, shows both nuclear and cytoplasmic localization. The localization of TAF-I in conjunction with the regulation of its activity is discussed.

Amino Acid Sequence↗

PubMed1998

Propofol anesthesia for cesarean section successfully managed in a patient with moyamoya disease.

We report a case of general anesthesia in a 25 year-old female patient with moyamoya disease who presented for cesarean section. General anesthesia was induced with propofol 100 mg, succinylcholine 50 mg, and nicardipine 1 mg intravenously (i.v.), and maintained with 60% nitrous oxide in oxygen. Just after the clamp of the umbilical cord, propofol 10 mg/kg/hr following propofol 50 mg pentazocine 15 mg vecuronium 8 mg, and methylergometrine maleate 0.2 mg were given i.v. The rate of infusion of propofol was reduced to 8 mg/kg/hr 10 minutes after the clamp and reduced to 6 mg/kg/hr 20 minutes after the clamp. Additional pentazocine 15 mg was given i.v. Blood pressure was maintained between 110 and 145 systolic, and 50 and 85 diastolic mmHg, and end-tidal carbon dioxide was between 34 and 36 mmHg. No postoperative deterioration of the patient's neurologic findings occurred. For the anesthetic management of moyamoya disease patients, especially in delivery, it is important to avoid hemodynamic changes and to maintain cerebral blood flow (CBF). We used propofol for hemodynamic stability and avoided hyperventilation so as to maintain CBF. We successfully managed the patient perioperatively.

Adult↗

PubMed1998

Interpleural misplacement of an epidural catheter.

We report a case of interpleural misplacement of an epidural catheter possibly caused by inappropriate angle of the Tuohy needle. A 71-year-old man was scheduled for left lower lobectomy of the lung with general and epidural anesthesia. A 18-gauge Tuohy needle was introduced into the Th5-Th6 interspace with a right paramedian approach. The direction of the epidural needle was at an angle of about 30 degrees from the skin directed cephalad. The needle was advanced 8 cm from the skin, where loss-of-resistance feeling was evident, and an epidural catheter was easily inserted 5 cm beyond the needle tip. Administration of 7 ml of 1.5% lidocaine given 20 minutes before skin incision did not alter arterial blood pressure or heart rate. Thoracotomy was performed via the fifth intercostal space. The surgeon then found the epidural catheter to be in the left pleural cavity. The catheter was immediately withdrawn. It is, therefore, necessary to employ the appropriate angle of the Tuohy needle on attempting epidural anesthesia to avoid the complication that we experienced.

Aged↗

PubMed1998

[Anesthetic managements of a patient with multiple sclerosis using propofol].

We experienced anesthetic management of a 45-yr-old female patient with a 12-yr history of multiple sclerosis who underwent orthopedic surgeries three times under general anesthesia. We chose rapid induction with propofol and maintained the anesthesia with nitrous oxide, oxygen, and sevoflurane. We monitored both core and peripheral temperatures to avoid the rapid increase of core temperature, which might worsen the symptoms of the disease. There is no other report of anesthesia using propofol as induction agent for a patient with multiple sclerosis. We succeeded in the satisfactory perioperative management of the patient.

Anesthesia, General↗

PubMed1997

The minimum alveolar concentration of sevoflurane in rats.

There are only limited data on sevoflurane minimum alveolar concentration (MAC) in rats. This study was designed to determine the minimum alveolar concentration value for sevoflurane in younger and older rats. Minimum alveolar concentration determination was performed in spontaneously breathing animals, 9-week-old rats (younger, n = 8) and more than 13-month-old rats (older, n = 8). Rats were instrumented with a silastic catheter in the abdominal aorta via the femoral artery to allow for arterial blood gas sampling. Subsequently, minimum alveolar concentration for sevoflurane was determined in 40 younger and 38 older rats. Minimum alveolar concentration for sevoflurane in younger rats was significantly higher than in the older rats (2.68 +/- 0.19 vs. 2.29 +/- 0.19, P < 0.001). Subgroup analysis indicated that minimum alveolar concentration for sevoflurane was not affected by the presence of an arterial catheter in the abdominal aorta (younger, 2.75 +/- 0.08 vs. 2.67 +/- 0.21; older, 2.23 +/- 0.19 vs. 2.30 +/- 0.18). Minimum alveolar concentration is profoundly affected by the age of the animal, but not by limited instrumentation.

Aging↗

PubMed1997

Mechanism of the negative inotropic effect of midazolam and diazepam in cultured foetal mouse cardiac myocytes.

We have investigated the effects of midazolam and diazepam on intracellular calcium (Ca2+) handling in foetal mouse ventricular myocytes using the Ca(2+)-sensitive fluorescent indicator, indo-1. We also investigated separately whether flumazenil or the L-type Ca2+ channel agonist, Bay K8644, antagonized these myocardial depressive effects. Midazolam and diazepam decreased the Ca2+ transient and beating rate in a concentration-dependent manner, and these decreases were prevented by Bay K8644. Flumazenil did not antagonize the myocardial depressive effects. In myocytes whose sarcoplasmic reticulum was inhibited by ryanodine, midazolam and diazepam had the same potent cardiodepressive effects. Midazolam and diazepam are direct cardiac depressants, which decrease the Ca2+ transient and beating rate, and the L-type Ca2+ channel is important in the negative inotropism and chronotropism caused by these drugs.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1996

Characterization of cyclophilin 40: highly conserved protein that directly associates with Hsp90.

Cyclophilin 40 (CyP4O) is a recently identified member of the cyclophilin family that may be a component of unactivated steroid receptor complexes. It consists of an N-half portion that is highly homologous to cyclophilin A and has peptidyl prolyl isomerase (PPIase) activity, and a C-half portion that resembles the C-terminal portion of FKBP52 (FK506 binding protein 52), another component of unactivated steroid receptor complexes. To better understand the structure and functional characteristics of this new class of cyclophilin, we have raised monoclonal antibodies against the C-half portion of human CyP4O. Immunostaining with the antibodies showed its preferential localization in cytoplasm. One antibody cross-reacted with a 45 kDa protein in yeast, suggesting high conservation throughout evolution. A CyP4O-associated protein was isolated from rabbit reticulocyte lysate by means of an affinity resin, and was identified as hsp90. The C-half portion of CyP4O was necessary and sufficient for the interaction.

Amino Acid Isomerases↗

PubMed1996

[Anesthetic management of a patient with thymoma presenting superior vena cava syndrome].

We report a case of thymoma presenting superior vena cava syndrome. Anesthesia for biopsy or excision of an anterior mediastinal mass has been associated with major airway and cardiac complications. Therefore, careful anesthetic management is necessary. The patient was kept on Fowler's position, and anesthesia was induced with thiamylal. The patient was intubated with succinylcholine and allowed to breath spontaneously until the sternal incision. Thereafter we used vecuronium and controlled ventilation was maintained. Intraoperatively, arterial pressure, central venous pressure, and right- and left-brachiocephalic vein pressures were monitored. After bypasses between right atrium and right- and left-brachiocephalic vein had been made, the venous pressures decreased remarkably. Various methods for preventing side effects resulted in good control during the perioperative period.

Anesthesia, General↗

PubMed1996

[A case of coronary artery spasm during burr hole opening for craniotomy].

We report a rare case of coronary artery spasm during burr hole opening for craniotomy in a patient with no past history of coronary artery disease. A 52-year-old man was scheduled for the removal of the brain tumor under general anesthesia. Anesthesia was induced with fentanyl, thiamylal, and vecuronium, and maintained with sevoflurane plus nitrous oxide in oxygen. When burr holes were made for the craniotomy, the heart rate decreased suddenly and the ECG in lead II demonstrated the elevation of the ST segment (0.3mV). After about 1 min, the ST segment elevation returned to normal without any treatment. The dura mater was rather tense with inspection. Despite many reported cases of coronary artery spasm during general anesthesia, coronary artery spasm during burr hole opening for craniotomy has not been reported. In the present case, since the heart rate decreased and the elevation of the ST segment occurred at the time of the burr hole opening for craniotomy, the activated vagal tone reflex induced by the stimulation of the dura mater seemed to have caused the coronary artery spasm.

Anesthesia, General↗

PubMed1995

Cardiac effects of methylmethacrylate in the rat heart-lung preparation with or without volatile anesthetics.

We have assessed the deleterious effects of methylmethacrylate (MMA) on cardiac function and metabolism in the isolated heart-lung preparation with or without volatile anesthetics. Wistar rats were prepared for the heart-lung model. They were randomly divided into 5 groups as follows. (1) Control (C) group. (2) Cement (M) group; they received MMA. (3) Halothane (H) group; they received MMA and 1% halothane. (4) Isoflurane (I) group; they received MMA and 1.5% isoflurane. (5) Sevoflurane (S) group; they received MMA and 2.5% sevoflurane. MMA 1000 micrograms/ml was administered 7 min after the start of perfusion except in the C group. At the end of the experimental period, the hearts were freeze-clamped and then myocardial high energy phosphates, lactate and glycogen were measured. Cardiac output in all groups but C group decreased significantly. PO2 of the perfusion blood in the M, H, I and S groups was significantly lower than that in the C group. Myocardial ATP in the M, H, I and S groups was significantly lower than that in the C group. ADP and AMP in the M, H, I and S groups were higher than those in the C group. There were no significant differences in lactate and glycogen levels between the 5 groups. MMA 1000 micrograms/ml is much higher than the blood level (0.05-31.89 micrograms/ml) which was reported in clinical patients who had femoral prosthesis. Therefore, the direct contribution of MMA itself to cardiac depression may be less than the other factors such as embolism in clinical situations. Volatile anesthetics did not influence the deleterious effects of MMA on cardiac function and metabolism.

Anesthetics↗

PubMed1995

[Alterations of cardiac function and metabolism in the rat heart-lung preparation by methyl methacrylate (MMA) and their protection by ulinastatin].

We have assessed the deleterious effects of methyl methacrylate (MMA) on cardiac function and metabolism in the isolated heart-lung preparation and their protection by ulinastatin. Twenty-four male Wistar rats were prepared for the heart-lung model. They were randomly divided into 3 groups. In the MMA (M) and ulinastatin (U) groups, MMA 1000 micrograms.ml-1 was administered 7 minutes after the start of perfusion. At the end of the experimental period, the hearts were freeze-clamped and then myocardial high energy phosphates, lactate and glycogen were measured. Cardiac output decreased significantly in the M and U groups. Po2 of the perfusion blood in the M and U groups was significantly lower than that in the control (C) group. Myocardial ATP in the M and U groups was significantly lower than that in the C group. ADP and AMP in the M and U groups were higher than those in the C group. Although there was no significant difference in lactate levels among the 3 groups, glycogen in the U and C groups was significantly higher than that in the M group. MMA 1000 micrograms.ml-1 is much higher than the blood level (0.05-31.89 micrograms.ml-1) reported clinically in patients who had femoral prosthesis. Ulinastatin increased myocardial glycogen content which had been reduced by MMA. This may suggest that ulinastatin has a protective effect on heart damaged by MMA.

Adenosine Diphosphate↗

PubMed1994

Monoclonal antibodies distinctively recognizing the subtypes of inositol 1,4,5-trisphosphate receptor: application to the studies on inflammatory cells.

Monoclonal antibodies were raised that specifically recognize the COOH-terminal sequences and the loop sequences between the fifth and the sixth transmembrane spanning regions of human inositol 1,4,5-trisphosphate receptor (IP3R) type 1, 2 and 3. Western blot analysis using Jurkat cells, mouse cerebellum, COS-7 expressing IP3R type 3 cDNA showed that those monoclonal antibodies reacted specifically with each of these three IP3R subtypes and that they do not cross-react. These antibodies could be used for the specific immunoprecipitation of IP3Rs. Using these monoclonal antibodies, the expression profiles of IP3R-subtype proteins were found to be different among inflammatory cells such as macrophages, polymorphonuclear cells, mast cells, eosinophils, splenocytes, thymocytes and megakaryocytic cells. Usually, more than one type of IP3R were expressed in a cell simultaneously. The observation of CMK cells under immunofluorescence confocal microscopy revealed that IP3R type 1 and type 2 are located at different subcellular fractions.

Amino Acid Sequence↗

PubMed1994

Immunoglobulin class switch of anti-ganglioside monoclonal antibody from IgM to IgG.

Ganglioside GM2, which is one of the major gangliosides expressed on cell surface of neuroectodermal-origin human tumors, has been focused on as a target molecule for passive immunotherapy. One of the problems in this area was that monoclonal antibodies (mAbs) raised against GM2 were of IgM class even if donors of B cells were varied in mouse, rat or human. We stimulated two kinds of mice hybridomas having membrane-bound anti-GM2 IgM on their surface with GM2 incorporated in synthetic liposomes in the presence of the mouse thymocytes to accelerate the class switch of immunoglobulins (Igs). After the stimulation, protein A-reactive clones were sorted out using a cell sorter. We finally isolated two class switch variants generating mouse IgG3, designated KM796 and KM750, from original hybridomas producing mouse IgM anti-GM2 mAbs, KM696 and KM697, respectively after over 20-time repetitions of the sorting. ELISA with 11 common gangliosides revealed that one of the variant, KM750, retained the same binding specificity to N-acetyl GM2 as that of the parental IgM, KM697. By ELISA using panel of anti-idiotype (Id) mAbs to anti-GM2 mAbs, KM750 was shown to retain the parental KM697 Id. Another variant KM796 almost lost its activity in purification process in acidic condition and changes in Id were suggested. In immunofluorescence assay, KM750 was confirmed to bind to GM2-expressing tumor cell lines. The class switch hybridoma has been stably cultured with the production of the IgG3-class mAb for more than 22 months.

Animals↗

PubMed1993

Differently spliced cDNAs of human leukocyte tyrosine kinase receptor tyrosine kinase predict receptor proteins with and without a tyrosine kinase domain and a soluble receptor protein.

Leukocyte tyrosine kinase (LTK) is a tyrosine kinase that has been suggested to be specific for hematopoietic cells and neuronal cells and reported as an unusual membrane protein lacking an extracellular domain. Here we report the cloning of a human LTK cDNA clone containing the complete open reading frame of a putative receptor tyrosine kinase protein. The extracellular domain of the receptor protein is larger than previously predicted. Furthermore, we have cloned a set of cDNAs representing differently spliced human LTK mRNAs. These cDNAs predict a truncated receptor protein lacking the tyrosine kinase domain and a soluble receptor protein that has neither a transmembrane nor a tyrosine kinase domain. Our results suggest that the LTK gene produces not only the putative receptor tyrosine kinase for unknown ligand but also multiple protein products that may have different functions.

Alternative Splicing↗

PubMed1993

Identification of the human ltk gene product in placenta and hematopoietic cell lines.

Two different monoclonal antibodies (MAbs) were raised against an extracellular domain and a C-terminal portion of the human ltk protein which is a receptor-type protein tyrosine kinase. Western blot analysis showed that these MAbs specifically immunoprecipitated a 100 kDa ltk protein which was transiently expressed in COS-1 cells transfected with a human ltk cDNA. By an in vitro immune complex kinase assay using these MAbs, a 100 kDa phosphoprotein was detected in human placenta and hematopoietic cell lines. These data indicate that the ltk gene product expressed in human placenta and hematopoietic cells shows tyrosine kinase activity. This is the first detection of native ltk protein naturally expressed in human cells.

Amino Acid Sequence↗

PubMed1993

The mechanism for the activation of latent TGF-beta during co-culture of endothelial cells and smooth muscle cells: cell-type specific targeting of latent TGF-beta to smooth muscle cells.

Transforming growth factor-beta (TGF-beta) is secreted in a latent form and activated during co-culture of endothelial cells and smooth muscle cells. Plasmin located on the surface of endothelial cells is required for the activation of latent TGF-beta (LTGF-beta) during co-culture, and the targeting of LTGF-beta to the cellular surface is requisite for its activation. In the present study, the cellular targeting of LTGF-beta was examined. We detected the specific binding of 125I-large LTGF-beta 1 isolated from human platelets to smooth muscle cells but not to endothelial cells. A mAb against the latency-associated peptide (LAP) of large LTGF-beta 1 complex, which blocked the binding of 125I-large LTGF-beta 1 to smooth muscle cells, inhibited the activation of LTGF-beta during co-culture. The binding of 125I-large LTGF-beta 1 could not be competed either by mannose-6-phosphate (300 microM) or by the synthetic peptide Arg-Gly-Asp-Ser (300 micrograms/ml). These results indicate that the targeting of LTGF-beta to smooth muscle cells is required for the activation of LTGF-beta during co-culture of endothelial cells and smooth muscle cells. The targeting of LTGF-beta to smooth muscle cells is mediated by LAP, and the domain of LAP responsible for the targeting to smooth muscle cells may not be related to mannose-6-phosphate or an Arg-Gly-Asp sequence, both of which have been previously proposed as candidates for the cellular binding domains within LAP.

Amino Acid Sequence↗

PubMed1991

Human myasthenia gravis thymic myoid cells: de novo immunohistochemical and intracellular electrophysiological studies.

Thymic myoid cells from myasthenia gravis (MG) patients and controls were successfully grown in explant cultures: we have compared them with skeletal muscle cells cultured from biopsies in morphological, immunohistochemical and electrophysiological studies. Some mononucleate cells in thymus cultures were myoglobin- or desmin-positive, but they were much rarer than the otherwise similar fusing myoblasts in muscle cultures. Frequencies of cultured myoglobin-positive cells showed no difference between MG and control and male or female, but were lower in samples of malignant thymoma, in younger cases and in those with less severe MG. Electrophysiologically the resting membrane potentials of cultured thymic multinucleate cells were significantly less than those of cultured skeletal muscle cells, and action potentials by electrical stimulation were rarely observed. In thymus cultures from only one case with malignant thymoma, desmin-positive myotubes had spontaneous irregular contractions followed by electrical firings. It is concluded that there are myoid cells in MG and control thymuses which have the potential to become skeletal muscle fibers morphologically and electrophysiologically, although their frequency and proliferation in culture are quite low.

Adolescent↗