Biomedical subjects

A Hagiwara

Publications and source records attributed to A Hagiwara.

At least 37 records · Page 2Linked to original sources

PubMed2001

Epoprostenol sodium, a prostaglandin I2, lacks tumor promoting effects in a medium-term liver carcinogenesis bioassay in rats.

Potential modifying effects of epoprostenol sodium administration on liver carcinogenesis were investigated in male F344/DuCrj rats initially treated with N-nitrosodiethylamine (DEN). Two weeks after a single dose of DEN (200 mg/kg, intraperitoneally), rats daily received subcutaneously epoprostenol sodium at doses of 0, 1, 10 and 100 microg/kg, or were fed phenobarbital sodium (PB) at a dietary level of 500 parts per million (ppm) as positive control for 6 weeks. All animals were subjected to partial hepatectomy at week 3, and were killed at week 8. Prominent flushing of extremis and signs of behavioural depression occurred after injection and lasted for 1 h in rats given 100 microg/kg epoprostenol sodium. Such clinical signs were slight in rats treated with 10 microg/kg, but not observed with 1 microg/kg. Marked decrease in body weight gain was noted in rats given 100 microg/kg. Statistically significant changes in relative liver weights were not found in any group given the test chemical. Epoprostenol sodium did not significantly increase the quantitative values for glutathione S-transferase placental form (GST-P) positive liver cell foci observed after DEN initiation, in clear contrast to the positive control. The results thus demonstrate that epoprostenol sodium lacks modifying potential for liver carcinogenesis in our medium-term bioassay system.

Animals↗

PubMed2001

The "botryoid sign": a characteristic feature of rhabdomyosarcomas in the head and neck.

We investigated nine patients with rhabdomyosarcoma in the head and neck (6-53 years of age), using CT and MRI. The tumours originated in the paranasal sinuses (3), cheek (2), soft palate (1), orbit (1), sternocostoclavicular muscle (1) and parapharyngeal space (1). The histological subtype was embryonal in five, alveolar in three and pleomorphic in one case. The tumours enhanced markedly and heterogeneous on CT and MRI. The masses were isointense or gave slightly higher signal than surrounding muscles on T1- and heterogeneously high signal on T2-weighted images. In four tumours, multiple ring enhancement resembling bunches of grapes. This appears to be characteristic of rhabdomyosarcoma and probably reflects a component of botryoid-type rhabdomyosarcoma in which mucoid-rich stroma is covered with a thin layer of tumour cells. We have named this imaging feature the "botryoid sign".

Adolescent↗

PubMed2001

Is timing of death from tumor recurrence predictable after curative resection for gastric cancer?

It is still difficult to predict whether cancer in patients who undergo curative gastrectomy for gastric cancer will recur and when they will die of recurrence. This study clarified predictive factors related to timing of death from tumor recurrence. A multivariate analysis was used to assess the dependence of death on postoperative tumor recurrence and were the dependence of the timing of death on tumor recurrence. Patients were divided into two groups according to the timing of death: those who died of tumor recurrence less than 2 years after surgery and those who died more than 2 years after surgery. Depth of cancer invasion, regional lymph node metastasis, and tumor size were independently correlated with tumor recurrence after curative gastrectomy. Onlv the depth of cancer invasion independently correlated with the timing of death due to tumor recurrence. It might be possible to predict the timing of death from tumor recurrence by the depth of cancer invasion into the gastric wall.

Female↗

PubMed2001

Combined use of electrosurgical incisions and balloon dilatation for the treatment of refractory postoperative pyloric stenosis.

BACKGROUND: Drug therapy plus balloon dilatation without gastroscopic incision does not always relieve postoperative pyloric stenosis. METHODS: Five patients with postoperative pyloric stenosis whose symptoms did not improve with drug therapy and balloon dilatation underwent a combination of gastroscopic incision and balloon dilatation. Two or 3 small radial incisions were made in the stenotic muscle of the pylorus electrosurgically at gastroscopy. Then the stenotic muscle layer was loosened and split bluntly along the incisions with balloon dilatation for 15 to 20 minutes. One week later, the combination procedure or balloon dilatation alone was repeated to prevent restenosis. RESULTS: In the 5 patients, the stenosis was improved with the combination therapy. No complications were observed. CONCLUSIONS: Combined use of gastroscopic incision and balloon dilatation may be considered for patients with refractory pyloric stenosis caused by surgical truncal vagotomy.

Aged↗

PubMed2001

Tumor cytotoxicity of peritoneal macrophages induced by OK-432.

In the present study we investigated the enhancement of cytotoxicity of peritoneal macrophages induced by OK-432. Rats received an i.p. injection of OK-432 at doses of 0.1, 0.5 or 1.0 KE/rat. Two days later, rats were sacrificed and peritoneal macrophages were isolated. Then the number of macrophages was counted, and the macrophages were analyzed for their lactic dehydrogenase (LDH) activity, acid phosphatase (ACP) activity, phagocytic activity, secretion of nitric oxide (NO) and cytotoxicity. The number of peritoneal macrophages, the activity of LDH and ACP, phagocytic activity, NO secretion, and cytotoxicity were increased with the increasing doses of OK-432. The results suggested that OK-432 enhanced tumor cytotoxicity of peritoneal macrophages by three steps. The first step is to attract a great number of macrophages into the peritoneal cavity. The second step is to enhance the phagocytic and eliminating function of these macrophages. The last step is to increase the non-contact cytotoxicity of macrophages.

Acid Phosphatase↗

PubMed2001

The role of interventional radiology in the management of blunt renal injury: a practical protocol.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of a protocol designed to minimize the need for surgery in the management of severe blunt renal injury. METHODS: Forty-six of 752 trauma patients had evidence of renal injury on computed tomographic (CT) scan. Two patients required emergency laparotomy, and the remaining 44 patients were classified by CT scan grade using the American Association for the Surgery of Trauma classification system. Patients with CT scan grade 3 or over underwent renal angiography. RESULTS: Twenty-one patients had a high-grade injury on CT scan (> or =3). Eight had angiographic evidence of extravasation from renal arterial branches and underwent transarterial embolization. One patient with a grade 5 injury had extravasation from a main renal vein and underwent immediate laparotomy. This was the only patient who required surgery for renal injury. CONCLUSION: Surgery can be avoided in most cases of blunt renal injury. Hemodynamic instability and injury to main renal veins remain indications for surgical exploration.

Abdominal Injuries↗

PubMed2001

[Reduction of medical resources utilization by influenza vaccination for hospitalized elderly patients].

In order to evaluate the economic efficacy of influenza vaccination for the elderly inpatients, we have investigated the health insurance fee of elderly inpatients in Japan. It was revealed that the health insurance fee varied by patients largely, ranging from 7,000 yen to 90,000 yen. Primary reason of this variation was due to the existence of the same effective drugs with variant prices and there were no rules concerning the period of drug medication. Thus, it was found that it would be improper to use the medication fee as a measure in evaluating the effects of influenza vaccinations. In this study, we used the length of days of testing and medication such as oral antibiotics, blood cell count, etc. as a measure to evaluate the effect of influenza vaccination. We compared these measures among elderly hospitalized patients with influenza vaccination or without influenza vaccination by ADL. Mean length of days of oral antibiotics was 2.64 (+/- 6.40) days for those with vaccination, and 3.92 (+/- 7.31) days for those without vaccination. Mean length of days of injection antibiotics was 2.52 (+/- 5.53) days for those with vaccination, and 8.82 (+/- 15.1) days for those without vaccination. Mean length of days of cells blood counter was 2.63 (+/- 2.22) days for those with vaccination, and 4.44 (+/- 3.20) days for those without vaccination. Mean length of days of chest X-ray was 1.30 (+/- 2.07) days for those with vaccination, and 2.56 (+/- 3.49) days for those without vaccination. These results suggest that influenza vaccination reduces medical utilization of resources. It was also revealed that influenza vaccination is most effective when elderly patients who are bed-bound are vaccinated.

Aged↗

PubMed2001

Haemorrhagic hepatic cyst: a differential diagnosis of cystic tumour.

A 63-year-old man was found on ultrasound examination to have a hepatic cystic mass with a mural nodule, which was mildly enhanced on contrast enhanced CT and MRI. At surgery, the cystic fluid was haemorrhagic and histological examination of the mural nodule demonstrated an organized haematoma. This case is of interest in that an apparent mural nodule was present in a non-neoplastic cyst. Haemorrhagic hepatic cyst with an organized haematoma should be included in the differential diagnosis of cystic neoplasms.

Cysts↗

PubMed2001

[Intraoperative coating of tumor surface using fibrin glue as a prophylaxis for cancer cell detachment].

With the aim of preventing cancer cells from becoming detached and spreading into the abdominal cavity by operative procedures during surgical resection of cancer infiltrating into gastrointestinal serosa, the exposed area of the serosa in mice was coated with fibrin glue, a biological tissue adhesive, prior to resection. We then determined whether the coating could reduce the detachment and spread of cancer cells during the surgical procedure, and thus be capable of inhibiting the occurrence of peritonitis carcinomatosa. In vitro experiments demonstrated that the fibrin glue uniformly and strongly coated the exposed area of cancer, and furthermore, that the presence of fibrin glue coating significantly reduced the number of cancer cells which became detached. As a result of using this glue, the number of deaths due to peritonitis carcinomatosa among assay mice was significantly decreased. It is therefore considered that coating the exposed area of cancer with fibrin glue inhibits cancer cells from being detached and spread during an operation, and thus can be an effective means of preventing the recurrence of peritonitis.

Animals↗

PubMed2001

[Analysis of the action of dextran sulfate as a prophylaxis for peritoneal cancer metastasis, and its acting mechanism].

Although peritoneal cancer metastasis has the highest frequency of postoperative recurrence among digestive organ malignant tumors, there is no still decisive treatment. Dextran sulfate (DS) as a prophylaxis for cancer metastasis was examined with respect to its effect on cultured cells. DS was made to act on a strong adhesive neoplasm cell, and the action and acting mechanism were examined with respect to 1. readhesiveness, 2. cell cycle, and 3. gene analysis. The results suggest that: i) Once tumor cells are detached by DS, the free cells do not attach even when DS is removed, and ii) DS causes the cells to stop in the G1/G0 phase.

Animals↗

PubMed2001

[Usefulness of local administration of methotrexate bound to activated carbon particles (MTX-CH)].

We developed a new dosage formulation, methotrexate bound to activated carbon particles (MTX-CH), and used it to reduce tumors via its long-acting effect at the administration sites. MTX-CH was injected locally into tumors on the back of BALB/c mice, 30 mg/mouse, as MTX and compared with mice treated with MTX aqueous solution, saline solution, activated carbon particles (CH-40) and non-treated mice. The MTX concentration at the administration sites was higher in the MTX-CH group than in the MTX aqueous solution group. A marked effect on the control of tumor growth by MTX-CH was noted after repeated administration (every 3 days, total 4 times) throughout the observation period. Although tumor size was not reduced, necrosis was microscopically observed around the site of MTX-CH administration. For the reasons mentioned above, MTX-CH is superior to MTX aqueous solution in terms of long-acting effect at the administration sites and the control of tumor growth.

Animals↗

PubMed2000

Neuronal cell apoptosis by a receptor-binding domain peptide of ApoE4, not through low-density lipoprotein receptor-related protein.

Since an apolipoprotein E4 (ApoE4) peptide composed of the low-density lipoprotein (LDL) receptor-related protein (LRP)-binding domain [ApoE4(141-149)(2) or ApoE(141-155)(2)] exerts neurotoxicity in primary neurons and neuronal cell lines, it has been controversial whether these effects are mediated by LRP. Here, we examined whether ApoE4(141-149)(2)-induced toxicity is mediated by LRP in a neuronal cell system where ApoE4 toxicity is mediated by LRP: serum-deprived F11 neuronal cells. In these cells, where ApoE4 exerted toxicity by apoptosis in a manner sensitive to both caspase inhibitors and pertussis toxin (PTX), ApoE4(141-149)(2) also caused cell death by apoptosis but in a caspase-inhibitor-resistant, PTX-resistant manner. ApoE4(141-149)(2)-induced death was not inhibited by antisense oligonucleotides to LRP. Therefore, we conclude that ApoE4(141-149)(2) is able to exert neurotoxicity without involving LRP.

Amino Acid Sequence↗

PubMed2000

Neuronal apoptosis by apolipoprotein E4 through low-density lipoprotein receptor-related protein and heterotrimeric GTPases.

The epsilon4 genotype of apolipoprotein E (apoE4) is the most established predisposing factor in Alzheimer's disease (AD); however, it remains unclear how apoE4 contributes to the pathophysiology. Here, we report that the apoE4 protein (ApoE4) evokes apoptosis in neuronal cells through the low-density lipoprotein receptor-related protein (LRP) and heterotrimeric GTPases. We examined neuron/neuroblastoma hybrid F11 cells and found that these cells were killed by 30 microg/ml ApoE4, but not by 30 microg/ml ApoE3. ApoE4-induced death occurred with typical features for apoptosis in time- and dose-dependent manners, and was observed in SH-SY5Y neuroblastomas, but not in glioblastomas or non-neuronal Chinese hamster ovary cells. Activated, but not native, alpha2-macroglobulin suppressed this ApoE4 toxicity. Suppression by the antisense oligonucleotide to LRP and inhibition by low nanomolar concentrations of LRP-associated protein RAP provided evidence for the involvement of LRP. The involvement of heterotrimeric GTPases was demonstrated by the findings that (1) ApoE4-induced death was suppressed by pertussis toxin (PTX), but not by heat-inactivated PTX; and (2) transfection with PTX-resistant mutant cDNAs of Galpha(i) restored the toxicity of ApoE4 restricted by PTX. We thus conclude that one of the neurotoxic mechanisms triggered by ApoE4 is to activate a cell type-specific apoptogenic program involving LRP and the G(i) class of GTPases and that the apoE4 gene may play a direct role in the pathogenesis of AD and other forms of dementia.

Animals↗

PubMed2000

Effect of periodical starvation on the life history of Brachionus plicatilis O.F. Müller (Rotifera): a possible strategy for population stability.

To estimate the changes in the life history of the rotifer Brachionus plicatilis O.F. Müller under starvation, we carried out an individual culture and determined the effects of periodical food deprivation on its asexual reproductive characteristics such as lifespan, reproductive period, age at first egg and offspring production, and lifetime fecundity (total number of offspring produced in her lifetime). Rotifers were fed for 1-3 h daily, and were then starved until the next day. Control animals were fed throughout their lifespan. Starved rotifers matured and produced their first offspring at an older age than the control animals. The periodical starvation resulted in a decrease in the lifetime fecundity to less than half that of the non-starved control. The reproductive period and lifespan were 2-3 times longer in the starved animals than in the control animals. The negative relationship between lifespan and lifetime fecundity is interpreted as a trade-off in an alternative life-history strategy of rotifers under starved conditions. The great decrease in fecundity and extension of lifespan enables rotifers to compensate to keep the population in equilibrium.

Journal Article↗

PubMed2000

An improved rapid procedure for fluorescence in situ hybridization that is applicable to intraoperative cancer cytodiagnosis.

Fluorescence in situ hybridization (FISH) is among the most simple and useful methods for detecting numerical and structural aberration of chromosomes but it requires 12-24 h to complete. We devised a rapid FISH method that can be performed within 2 h. Here we describe the technique, which we have found to be extreme simple and as sensitive and specific as standard FISH, making it highly suitable for clinical use.

Adult↗

PubMed2000

Outcome of prophylactic radical lymphadenectomy with gastrectomy in patients with early gastric carcinoma without lymph node metastasis.

BACKGROUND: Prophylactic extended lymphadenectomy with gastrectomy may prolong survival in patients with early gastric carcinoma without lymph node metastasis. However, the therapeutic value of extensive lymphadenectomy in patients with early gastric carcinoma remains controversial. METHODS: The authors retrospectively analyzed 423 patients with early gastric carcinoma without lymph node metastasis who underwent gastrectomy and did not die of other diseases to evaluate the effect of prophylactic extended lymphadenectomy on postoperative survival. The postoperative survival rate of patients who underwent prophylactic extended lymphadenectomy was compared with that of patients who underwent prophylactic limited lymphadenectomy. RESULTS: Although extended lymphadenectomy did not appear to improve the postoperative survival rate of patients with mucosal tumors, it did improve the postoperative survival rate of patients with submucosal tumors. Whether prophylactic extended lymphadenectomy was performed significantly affected outcome in patients with early gastric carcinoma who had submucosal tumors without regional lymph node metastasis. CONCLUSIONS: Extensive lymphadenectomy with gastrectomy should be performed to prolong the survival of the patients with submucosal tumors.

Aged↗

PubMed2000

Effect of juvenile hormone and serotonin (5-HT) on mixis induction of the rotifer Brachionus plicatilis Muller.

Juvenile hormone (JH) and serotonin (5-HT) were previously shown to enhance mictic (sexual) female production of the rotifer Brachionus plicatilis in batch cultures. To explore the basis of these effects, experiments were conducted on isolated individuals. JH treatment of maternal rotifers with 5 and 50 µgml(-1) (18.8 and 187.7 µM) resulted in significantly higher (P<0.05) mictic female production in the second (F(2)) and third (F(3)) generations. JH treatment was effective even at a lower food concentration of 7x10(5) cellsml(-1), but it was not effective when free ammonia was added at 2.4 and 3.1 µgml(-1). Mictic female production was not increased with exposure to 5-HT up to 50 µgml(-1) (129.1 µM) concentrations. When food level was reduced to 7x10(5) cellsml(-1), however, 5-HT-treated rotifers produced significantly (P<0.05) more mictic females than the control, particularly in F(3) generation. Mictic female production of 5-HT-treated rotifers did not differ from that of the control with or without free ammonia, but the intrinsic rate of natural increase (r) of 5-HT-treated rotifers at 3.1 µgml(-1) free ammonia was significantly higher than the control. These results show that juvenile hormone increases mictic female production under optimum and sub-optimum food levels, whereas 5-HT increases both mictic female production at low food level and population growth rate at high free ammonia concentrations. These compounds could be used to manage rotifer cultures and probe the mechanisms controlling the rotifer life cycle as it switches to mictic reproduction.

Journal Article↗

PubMed2000

Role of the DExH motif of the Japanese encephalitis virus and hepatitis C virus NS3 proteins in the ATPase and RNA helicase activities.

The role of the conserved DExH motif of the Japanese encephalitis virus (JEV) NS3 protein in the ATPase and RNA helicase activities was compared with that of the hepatitis C virus (HCV) NS3 protein. In the DExH motif of JEV NS3, Asp-285 and Glu-286 were essential for both ATPase and RNA helicase activities. Cys-287 was critical for the RNA helicase activity of JEV NS3 but not for ATPase activity. A His-288-to-Ala substitution in the DExH motif of HCV NS3 resulted in an increase in ATPase activity which was suppressed by poly(U). In contrast, alanine substitution at the same site in JEV NS3 did not increase basal ATPase activity which remained to be stimulated by poly(U). Thus, the mutational effect at His in motif II was different in the HCV and JEV NS3 proteins. Mutagenesis at His-288 of JEV NS3 revealed that His was the most preferable amino acid for ATPase activity and Ala, Gly, Asn, Gln, Ser, or Arg could partly substitute for it. However, any other mutation at His-288 completely disrupted the RNA helicase activity of JEV NS3. The results suggest that Cys-287 and His-288 are essential residues especially for the RNA helicase activity of JEV NS3 and the ATPase and helicase activities are separable enzymatic functions.

Adenosine Triphosphatases↗