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Biomedical subjects

Y Furuhashi

Publications and source records attributed to Y Furuhashi.

At least 19 recordsLinked to original sources
PubMed2001

A factor of inducing IgE from a filarial parasite is an agonist of human CD40.

Immune responses to parasitic helminth are usually characterized by quite mysterious phenomena: dominance of Th2-like immunity and antigen-nonspecific IgE secretion. We previously purified a factor from Dirofilaria immitis that induces antigen-nonspecific IgE in rats and named it DiAg. In the presence of IL-4, DiAg induces mouse B cells to secrete IgE, which is antigen-nonspecific polyclonal antibody. We investigated the biochemical characteristics of DiAg as a factor of inducing IgE in this study. Recombinant DiAg (rDiAg) with interleukin (IL)-4 induced IgE synthesis in highly purified human normal B cells in vitro cell culture systems. The addition of recombinant human soluble CD40 IgG fusion protein (rsCD40-Ig) inhibited induction of IgE synthesis by rDiAg with IL-4. Monocyte cells were stimulated with rDiAg and recombinant human soluble CD40L (rsCD40L); IL-12 and TNF-alpha were induced. The addition of rsCD40-Ig to THP-1 cells activated with rDiAg and rsCD40L inhibited the production of IL-12. rDiAg bound to the monocyte cell membrane fraction and recombinant human soluble CD40; this binding of rDiAg was competitively inhibited by addition of rsCD40L. Moreover, in CD40-deficient mice, IgE production and MLN-B cell proliferation by rDiAg were completely absent. Based on these results, we concluded that DiAg is an agonist of CD40.

Animals↗
PubMed2001

Optimal doses of paclitaxel and carboplatin combination chemotherapy for ovarian cancer: a phase I modified continual reassessment method study.

BACKGROUND: A multicenter, phase I study of combination therapy with paclitaxel and carboplatin for epithelial ovarian cancer was conducted to determine the safety and recommended dosages for Japanese women. METHODS: Paclitaxel was administered intravenously over a 3-h period, followed by carboplatin administered intravenously over a 1.5-h period. A modified continual reassessment method (mCRM) was used in two treatment arms to establish the maximum tolerated dose (MTD) and recommended doses of the combination. In group A, the dose of paclitaxel (175 mg/m2) was constant and the dose of carboplatin was increased from 4 to 7 in terms of the target area under the plasma concentration-versus-time curve (AUC). In group B, the dose of carboplatin was constant (AUC 6) and paclitaxel was administered at two dose levels (160 and 175 mg/m2). In both groups, the carboplatin dose was limited to a maximum of 800 mg/body for each administration. RESULTS: Because the calculated probability of toxicity was greatest at a dose of paclitaxel 175 mg/m2 and carboplatin AUC 7, this dose was designated the MTD in group A. Based on this result, treatment in group B was initiated at doses of paclitaxel of 160 mg/m2 and carboplatin AUC 6. While the dose of paclitaxel was escalated to 175 mg/m2, the safety of the combination was confirmed. The most frequent adverse effect was neutropenia, which resolved promptly with the appropriate use of granulocyte-colony stimulating factor (G-CSF). No other severe hematologic or nonhematologic toxicities were observed. CONCLUSIONS: Our study demonstrated that the recommended dose for this combination regimen should be paclitaxel 175 mg/m2 plus carboplatin AUC 6 (maximum dose, 800 mg/body).

Adenocarcinoma, Clear Cell↗
PubMed2001

Recombinant Dirofilaria immitis-derived antigen can suppress passive cutaneous anaphylaxis reactions.

BACKGROUND: High levels of antigen-nonspecific IgE are produced in animals infected with helminth parasites. Generally, the increase in IgE is thought to exacerbate allergic reactions. However, high levels of antigen-nonspecific IgE may alter some features of anaphylactic reactions. To investigate the molecular mechanisms of antigen-nonspecific IgE production induced during filarial infections, we previously constructed rDiAg (recombinant Dirofilaria immitis-derived antigen) in Escherichia coli. In the present study, we examined the effect of rDiAg on the production of antigen-nonspecific IgE and on allergic cutaneous reactions in rats. METHODS: Osmotic pumps filled with 200 microg of rDiAg or with 200 microl of PBS (control) were subcutaneously implanted in Wistar rats, and plasma samples were collected weekly thereafter. IgE levels were determined by ELISA. Homologous passive cutaneous anaphylaxis (PCA) reactions with anti-DNP-As IgE were examined 21 days after implantation. (125)I-IgE binding assays were examined on peritoneal mast cells from rDiAg-infused rats and control rats. RESULTS: Antigen-nonspecific IgE production was induced in rDiAg-infused rats. PCA reactions were suppressed in rDiAg-infused rats in spite of high levels of IgE and a markedly increased expression of Fc epsilon RI. (125)I-IgE did not bind to mast cells derived from rDiAg-infused rats, but it bound dose dependently to mast cells derived from control rats. CONCLUSION: The present data support the hypothesis that antigen-nonspecific IgE might protect against antigen-specific IgE by means of competition for mast cell receptors. rDiAg is an essential factor to induce antigen-nonspecific IgE in helminth infections.

Animals↗
PubMed2001

The biological activity of ABA-1-like protein from Ascaris lumbricoides.

The elevation of non-specific IgE (total IgE) in Ascaris infection can be seen one week after infection, and reaches a peak after approximately two weeks. It has been reported that ABA-1 protein is the main constituent in the pseudocoelomic fluid of Ascaris suum. To investigate the effect of the ABA-1-like protein from Ascaris lumbricoides (ALB), the cDNA was cloned by reverse transcriptase polymerase chain reaction, using original primers based on the consensus sequences of ABA-1 and TBA-1, that is an ABA-1-like protein from Toxocara canis. The clone was sequenced, we constructed the recombinant polyprotein of ALB (rALB14 and rALB7) based on the ALB sequence, and rALB was administrated to BALB/c mice. Fourteen days after inoculation with rALB14 which is the full length of ALB, the elevation of total IgE which we supposed to contain non-specific IgE was observed, and the results were as we expected. Furthermore, in an in-vitro experiment, we confirmed that the spleen cells proliferated when stimulated by rALB14 and concanavalin A. Therefore, the whole conformation of ALB is considered to be involved in the elevation of non-specific IgE, and is involved in the activation of T cells.

Allergens↗
PubMed2000

Navigation system for neurosurgery with PC platform.

This paper presents a navigation system for a surgical microscope and an endoscope which can be used for neurosurgery. In this system, a wireframe model of a target tumor and other significant anatomical landmarks are superimposed in real-time onto live video images taken from the microscope and the endoscope. The wireframe model is generated from a CT/MRI slice images. Overlaid images are simultaneously displayed in the same monitor using the picture-in-picture function so that the surgeon can concentrate on the single monitor during the surgery. The system measures the position and orientation of the patient using specially designed non-contact sensing devices mounted on the microscope and the endoscope. Based on this real-time measurement, the system displays other useful information about the navigation as well as the rendered wireframe. The accuracy of registration between the wireframe model and the actual live view is less than 2 mm. We tested this system in actual surgery several times, and verified its performance and effectiveness.

Equipment Design↗
PubMed1997

Clinical behavior of borderline ovarian tumors: a study of 150 cases.

BACKGROUND: We evaluated the clinical features, treatment, and survival status of the patients with borderline ovarian tumors. METHODS: A retrospective review of the charts of 150 patients with borderline ovarian tumor registered at the Tokai Ovarian Tumor Study Group from January 1, 1980, to December 31, 1994, was conducted to obtain clinical and pathological information. RESULTS: In stage II and III disease, the numbers of patients with no residual tumor, residual tumor of <2 cm, 2-5 cm, and >5 cm were 9, 10, 3, and 3, respectively. The sizes of residual tumors and corresponding clinical response to chemotherapy were as follows: residual tumor of <2 cm, complete response (CR), 6 patients; no change (NC), 2; progressive disease (PD), 2; tumors 2-5 cm, NC, 1 patient, PD, 2; tumors >5 cm, PD, 3 patients. The survival for patients with residual tumor <2 cm was significantly better than for those with residual tumor from 2-5 cm and of >5 cm (P < 0.05). The survival for patients with stage II and III serous tumor was significantly longer than that for patients with stage II and III mucinous tumor (P < 0.05). CONCLUSION: In advanced borderline ovarian tumor, the prognosis of patients with gross residual tumor after initial surgery, and especially with mucinous tumor, was poor.

Adolescent↗
PubMed1997

Development of a CAI program entitled 'Introduction to Nursing Process'. Requirement for nursing education in Japan.

A new teaching strategy is required in nursing education in Japan. A multimedia CAI (Computer Assisted Instruction) program entitled "Introduction to Nursing Process." was developed. The aim of this study was to examine whether CAI could assist students' knowledge acquisition, and increase their motivation and readiness to learn clinical nursing practice. This study involved the process of developing CAI and a pilot study for measuring and evaluating the CAI program. Results demonstrate that CAI can increase students' understanding about the nursing process, enhance their motivation to learn, and provide realistic situations describing the concept of nursing the process.

Computer-Assisted Instruction↗
PubMed1997

Conservative handling of the uterus in a 10-week cervical pregnancy case.

A patient with a living 10-week old cervical pregnancy who desired to preserve fertility was successfully treated with methotrexate, intraamniotic KCI injection and endocervical curettage. In the case of living cervical pregnancy even after 10 weeks, conservative treatment remains an option, although intensive management and care should be given.

Adult↗
PubMed1996

Possible effects of placental leucine aminopeptidase on the regulation of brain-gut hormones in the fetoplacental unit.

The hydrolysis of somatostatin by human placental subcellular fractions and pregnancy sera was studied in the presence of selective inhibitors and the antibody against pregnancy serum oxytocinase (placental leucine aminopeptidase; EC3.4.11.3) by measuring the released amino acids by high-performance liquid chromatography. We also studied the degradation of other brain-gut hormones, such as glucagon, growth hormone, growth hormone releasing factor, and insulin, in the human placenta and found that the human placenta degrades somatostatin, glucagon, and growth hormone releasing factor, but not insulin and growth hormone. The degradation velocity of somatostatin was ten times greater than that of growth hormone releasing factor in placental microsomal fractions. Our data suggest that the stimulatory control by growth hormone releasing factor is dominant in the fetal growth hormone secretion. Our data also identified the somatostatin-degrading protease in human placenta using placental leucine aminopeptidase. It is known that the mean somatostatin levels in the umbilical artery are about 2.5-fold higher than those in the umbilical vein. Our data on somatostatin levels in umbilical artery and vein of intrauterine growth retardation human fetuses showed that the ratio umbilical artery/vein is around 1. Since insulin is known to be the primary hormone regulating the ratio of fetal growth, our data suggest that the degradation of somatostatin in the placenta is decreased and that elongation of somatostatin effects may result in the inhibition of insulin secretion in the intrauterine growth retardation fetus.

Amino Acid Sequence↗
PubMed1995

[Perioperative management of patients with Meigs syndrome].

We report our perioperative management of three cases of Meigs syndrome. The major pre-operative problems in Meigs syndrome are physical trouble caused by giant mass in peritoneal space, respiratory distress, and poor nutrition. These problems must be settled before the operation. The important points in the pre-operative management are 1) respiratory care employing the intermittent positive pressure breathing (IPPB) and the pleural effusion drainage, and 2) the correction of intravascular volume and the concentration of albumin and hemoglobin by transfusion of massive lactated Ringer solution and albumin solution and/or whole blood when they are necessary. During the operation, the epidural anesthesia under spontaneous breathing is the best method of anesthesia. According to circumstances, we adopt the intra-tracheal intubation with continuous positive airway pressure breathing (CPAP). We can generally deal with excessive bleeding by transfusion of lactated Ringer solution and plasma expander, during the first half of operation. By the end of the operation, however, the correction of the concentration of albumin and hemoglobin must be made by the fresh frozen plasma and blood transfusion. After the operation, we use epidural analgesia to control the postoperative pain. We have succeeded in the treatment of three cases of Meigs syndrome owing to our perioperative management as described above.

Analgesia, Epidural↗
PubMed1993

Clinical remission criteria for epithelial carcinoma of the ovary.

After primary cytoreductive surgery 188 patients with epithelial ovarian cancer were treated with combination chemotherapy between 1986 and 1989 in the Tokai Ovarian Tumor Study Group. Clinical remission criteria were set in this study and patients were examined to determine if they were in remission or not. Forty-seven cases (25%) had no remission and 85.9% of them died within 20 months after primary surgery. Fifty-seven cases (30.3%) had a remission and a subsequent recurrence. Eighty-four cases (44.7%) had no recurrence and all are currently alive. Independent remission factors by multivariate analysis were higher stage (P = 0.018), clear-cell carcinoma (P = 0.0048), larger maximum residual tumor (P = 0.0023), and PVB therapy (P = 0.026). Independent recurrence factors were higher stage (P = 0.0012), serous cystadenocarcinoma (P = 0.0001), clear-cell carcinoma (P = 0.00409), and PVB therapy (P = 0.0499). A significantly high remission rate and low recurrence rate was achieved using PVB therapy. This criteria has value for the treatment of epithelial ovarian carcinoma. The disease-free survival rate after clinical remission was the same as that after a negative second-look laparotomy, which implies that a second-look laparotomy may be unnecessary in the management of epithelial carcinoma of the ovary.

Adenocarcinoma↗
PubMed1992

Accumulation of cis-diamminedichloroplatinum (II) and its analogues in sensitive and resistant human ovarian carcinoma cells.

Human ovarian carcinoma cell line (NOS2), established from a patient with serous cystadenocarcinoma of the ovary, has been exposed to a stepwise increase in cis-diamminedichloroplatinum (II) (CDDP) concentration to produce a CDDP-resistant cell line NOS2CR) as an experimental model for resistance to CDDP. NOS2CR cells showed a 7-fold resistance to CDDP and a lesser degree of cross-resistance to diammine (1,1-cyclobutanedicarboxylato)-platinum (II) (CBDCA) and (-)-(R)-2-aminomethylpyrrolidine (1,1-cyclobutanedicarboxylato) platinum (II) (DWA2114R). In the absence of CDDP, cross-resistance to DWA2114R was reduced to the original level by 2 months, although 83% resistance to CDDP remained up to 6 months. To investigate CDDP-resistant mechanisms, alterations in the intracellular accumulation of CDDP and analogues were assayed by atomic absorption. In both NOS2 and NOS2CR cells, accumulation of CDDP increased linearly with time and was concentration-dependent. NOS2CR cells demonstrated 71, 52 and 12% reduction in accumulation of CDDP, CBDCA, and DWA2114R, respectively. These reductions did not seem to be due to P-glycoprotein, because expression of multidrug-resistant 1 gene was not detected in either NOS2 or NOS2CR cells. These studies indicate that the mechanisms of resistance to CDDP and analogues in NOS2CR cells are related in the main to reduced intracellular accumulation of drugs. DWA2114R might be helpful to treat CDDP-resistant and recurrent tumors which were treated by CDDP.

Antineoplastic Agents↗
PubMed1991

Prognostic factors in yolk sac tumors of the ovary. A clinicopathologic analysis of 29 cases.

Twenty-nine ovarian cancer patients with yolk sac tumors and germ cell tumors with yolk sac tissue as a component of their disease (16 endodermal sinus tumor, 11 mixed germ cell tumors, one embryonal carcinoma, and one polyembryoma) were treated with cytoreductive surgery and combination chemotherapy. Prognostic factors were investigated in this group. Patients with Stage I disease had a more favorable prognosis (P less than 0.003) than those with Stages II and IV disease. The difference in prognosis was significant in cases where residual tumor was absent (P less than 0.003) and in cases where ascites was either absent or less than 100 ml in volume (P less than 0.05). Endodermal sinus tumor with either an intestinal (P less than 0.05) or microcystic pattern (P less than 0.01) was more common in survivors than in those who died. The age, preoperative serum alpha-fetoprotein level, maximum tumor size, and tumor weight had no significant correlation with prognosis. In advanced cases, chemotherapy regimens including cisplatin gave better results than those containing vincristine, dactinomycin, and cyclophosphamide (P less than 0.05). The optimal treatment of yolk sac tumors or tumors with yolk sac tissue as a component of the ovary is discussed in light of these results.

Adolescent↗
PubMed1991

Growth inhibitory effect of bestatin on choriocarcinoma cell lines in vitro.

Bestatin, one of the biological response modifiers (BRMs), is an inhibitor of aminopeptidase B (AP-B), leucine aminopeptidase (LAP) and aminopeptidase M (AP-M). In this report, we investigated the direct effect of bestatin on the growth of cancer cells in vitro using established four choriocarcinoma cell lines. In vitro chemosensitivity was evaluated by the succinate dehydrogenase inhibition (SDI) test. Bestatin showed the growth-inhibitory effect on all the choriocarcinoma cell lines dose-dependently, especially on NaUCC-4 cells. Both an isomer of bestatin with no inhibitory activity against aminopeptidases, (2R, 3S)-AHPA-(R)-Leu, and another isomer with stronger inhibitory activity against AP-B than bestatin, (2S, 3S)-AHPA-(R)-Leu, did not show growth inhibition on NaUCC-4 cells. So it is suggested that one of the possible mechanisms responsible for the direct action of bestatin on the choriocarcinoma cells may be related to the inhibition of activity of LAP or AP-M rather than that of AP-B. Furthermore, cytotoxicity of actinomycin D on the choriocarcinoma cells was significantly enhanced by combination with bestatin. These results suggest that bestatin has not only an indirect host-mediated anti-tumor activity, but also a direct growth-inhibitory effect on some kinds of cancer cell lines.

Aminopeptidases↗
PubMed1991

Immature teratoma of the ovary.

The purpose of this study was to establish the optimal management of immature teratoma of the ovary. Pursuant to this, 20 previously untreated patients with immature teratoma were evaluated. Nine patients were at stage I of the disease, 2 had progressed to stage II, and 9 to stage III. Eight patients had grade 1 tumors, 11 had grade 2 tumors, and 1 had a grade 3 tumor. Postoperative chemotherapy was performed in 19 cases. Vincristine, actinomycin D, and cyclophosphamide (VAC) were administered in 9 cases, chemotherapy including cisplatin (P) was administered in 8 cases, and other regimens were followed in the 2 remaining cases. The median follow-up period was 62 months (range 19-108 months), and no patient was lost to follow-up. After completion of the follow-up period, 18 patients were alive and disease free, 1 was alive with liver metastasis, and 1 had died. The patient who died had suffered from a grade 3 tumor, and the recurrent tumor was a rhabdomyosarcoma. As a result of this study, it was found that immature teratoma of grades 1 and 2 can be managed successfully with VAC or P therapy. Thus, a hysterectomy should not be automatically performed in patients who still hope to give birth, yet suffer from a grade 1 or 2 immature teratoma at the time of a second operation.

Abdominal Neoplasms↗
PubMed1991

Characterization of an established mouse-human heterohybridoma and its application for production of (mouse-human)-human triple hybridoma secreting human immunoglobulin.

We report the construction of a mouse-human (M-H) heterohybridoma by fusion of the murine myeloma cell line NS-1 and human spleen cells from a 17 week old fetus. The nonsecreting, cloned hybridoma cell line II was resistant to 8-azaguanine (8-AG) and sensitive to hypoxanthine, aminopterin and thymidine (HAT) medium. It grew rapidly in 8-AG containing medium (doubling time 20 hrs.), but did not grow in HAT medium or in non-serum medium. It had a high fusion frequency with human lymphocytes from regional lymph nodes. Five human chromosomes were retained stably for over 6 months by this cell line II. Nine (mouse-human)-human ((M-H)-H) triple hybridomas secreting human IgG 1 or IgM were established by the fusion of this parental cell line II and human lymphocytes from regional lymph nodes. Immunoglobulin secretion was stable and has been maintained for over 8-10 months without recloning in these hybridomas. Secretion of immunoglobulin varies from 2.1-3.0 micrograms/10(6) cells/day, and these hybridomas contain from 3 to 16 human chromosomes, including No. 14. So, this M-H heterohybridoma II is an excellent useful parental cell line for the production of hybridomas secreting human immunoglobulin.

Animals↗
PubMed1991

Sequence-dependent termination of mammalian DNA polymerase reaction by a new platinum compound, (-)-(R)-2-aminomethylpyrrolidine(1,1-cyclobutane-dicarboxylato)-2-plati num(II) monohydrate).

We examined the mechanism of the inhibition of DNA synthesis by a new platinum compound, (-)-(R)-2-aminomethylpyrrolidine(1,1-cyclobutane-dicarboxylato+ ++)-2-platinum(II) monohydrate (DWA-2114R), a derivative of the antitumor drug cis-diamminedichloroplatinum(II) (CDDP), using prokaryotic and eukaryotic DNA polymerases. Preincubating activated DNA with CDDP or DWA-2114R reduced its template activity for prokaryotic and eukaryotic DNA polymerases in a dose-dependent manner. DWA2114R required six times greater drug concentration and two times longer incubation time to show the same decrease of the template activity compared to CDDP. Treatment of primed pUC118 ssDNA templates with the two drugs followed by second-strand synthesis by prokaryotic and eukaryotic DNA polymerases revealed that DWA2114R bound to DNA in a similar manner to CDDP and these adducts blocked DNA elongation by DNA polymerases of eukaryotes as well as of prokaryotes. With these two drugs, the elongations by E. coli DNA polymerase I (Klenow fragment), T7 DNA polymerase and calf thymus DNA polymerase alpha were strongly arrested at guanine-guanine sequences (GG). Stop bands were also observed at adenine-guanine sequences (AG) guanine-adenine-guanine sequences (GAG) and mono-guanine sequence (G). Calf testis DNA polymerase beta was also arrested efficiently at AG, GAG and G, but much more weakly at GG. This pattern was common to DWA2114R and CDDP.

Animals↗