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Biomedical subjects

M Ohta

Publications and source records attributed to M Ohta.

At least 109 records · Page 6Linked to original sources
PubMed2001

Proximal M2 false aneurysm after head trauma--Case report.

A 72-year-old male presented with a post-traumatic false aneurysm of the right proximal M2 artery with massive subarachnoid hemorrhage after closed head injury. Serial computed tomography (CT) and angiography showed the development of the aneurysm which was verified at autopsy. He was admitted in a drowsy state just after a motorcycle accident. Initial brain CT showed subarachnoid hemorrhage without skull fracture. Follow-up brain CT showed a huge hematoma in the right temporal lobe. He died 47 hours after the accident. Histological examination of the aneurysm showed a false aneurysm. Delayed diagnosis of traumatic aneurysms leads to high mortality, so early surgical treatment is essential to save such patients.

Accidents, Traffic↗
PubMed2001

Multi-level disruption of the spinal nerve root sleeves in spontaneous spinal cerebrospinal fluid leakage--two case reports.

A 37-year-old male and an 18-year-old male presented with spontaneous spinal cerebrospinal fluid (CSF) leakage from multiple nerve root sleeves. Both patients suffered abrupt onset of intense headache followed by nausea, dizziness, and one patient with and one without positional headache. Radioisotope spinal cisternography of both patients revealed that the CSF leaks were not localized in a special zone but distributed to multiple spinal nerve root sleeves. Magnetic resonance (MR) myelography suggested that the spinal CSF column was fully expanded to the root sleeves. The extraspinal nerve bundles demonstrated numerous high intensity spots. Both patients were treated conservatively, and their symptoms resolved within one month. Repeat radioisotope cisternography and MR myelography confirmed the spine was normal after recovery. We suggest that spreading disruption of the arachnoid membrane occurs at the nerve root sleeves due to CSF overflow into the spinal canal.

Adolescent↗
PubMed2001

Expression and distribution of the Kit receptor in bovine bone marrow cells.

OBJECTIVE: To characterize the expression and distribution of the Kit receptor in bovine bone marrow cells (BMC) and to define the function of its ligand, stem cell factor (SCF). ANIMALS: Six 7- to 70-day-old healthy male Holstein-Friesian calves. PROCEDURES: Expression and distribution of the Kit receptor were assessed by use of flow cytometry with monoclonal antibodies (mAb) against the bovine Kit protein. Using Giemsa-stained centrifuged preparations, the histologic appearance of Kit receptor positive (Kit+) BMC were evaluated. Semisolid cultures supplemented with granulocyte colony-stimulating factor (G-CSF) and SCF were used to measure the colony formation capacity of Kit+ BMC. RESULTS: The Kit receptor was expressed on approximately 18% of total BMC. Most of Kit+ BMC did not coexpress lineage markers, but a small subset of this population did coexpress CD3. The Kit+CD3- BMC were a heterogeneous cell population comprising blast-like cells such as myeloblasts, promyelocytes, rubriblasts, and prorubricytes. Conversely, Kit+CD3+ BMC had a lymphocyte-like appearance. Kit+ BMC formed colonies in semisolid culture with G-CSF, whereas Kit- BMC failed to grow. Addition of SCF to G-CSF resulted in superadditive enhancement in colony numbers and size. CONCLUSIONS: The Kit receptor is expressed primarily on immature blood cells in bovine bone marrow, and Kit+ BMC contain hematopoietic progenitor cells that are reactive to G-CSF. In addition, SCF synergizes with G-CSF to stimulate colony formation by these cells. Our results suggest that the Kit receptor and its ligand, SCF, are involved in early stages of granulopoiesis in calves.

Animals↗
PubMed2001

Effect of trichloroethylene on spatiotemporal pattern of LTP in mouse hippocampal slices.

The effect of trichloroethylene (TCE) on long-term potentiation (LTP) was studied using both electrical and optical recording. The hippocampi from mice injected with 300 mg/kg or 1000 mg/kg TCE were sliced 24 h after administration. The field potential from the CAI was recorded. After the application of tetanus, population spikes (PS) were potentiated in all groups, but the post-per-pre ratio of PS was smaller in TCE groups than in the control. Optical recording was also carried out in 1000 mg/kg TCE-injected mice and a new analytical method using a high speed camera was employed. After the induction of tetanus, the optical signal was potentiated in both TCE and control groups. However, the post-per-pre ratio of the optical signals and response area were smaller in the TCE groups than in the control. It was suggested that the impairment of LTP is one of the mechanisms of the impairment of immediate memory after acute exposure to TCE in humans.

Animals↗
PubMed2001

[A case of malignant lymphoma concomitant with multiple myeloma].

A 75-year-old woman was referred to us because of cough, high fever and skin erythema in April 1999. Malignant lymphoma (diffuse mixed cell type) was previously diagnosed in 1990 and she achieved complete remission after treatment with a series of CHOP regimen treatments. In 1998, multiple myeloma (IgG lambda type) was diagnosed and she was treated with a combination of melphalan and prednisolone. On physical examination, superficial lymphadenopathy and skin erythema were noted. Biclonal gammopathy (IgG kappa/lambda) was shown in serum, and Bence Jones protein in urine. Computed tomography showed pleural effusion and swelling of paraaortic lymph nodes. The bone marrow examination showed an increased number of abnormal plasma cells (19.2%) and no evidence of lymphoma. Left axillary lymph node biopsy revealed that she had non-Hodgkin's lymphoma (immunoblastic lymphadenopathy-like T cell lymphoma). She was treated with the CHOP regimen at reduced doses for both diseases. The lymphoadenopathy reduced after 6 courses of CHOP and 4 courses of CHOPE (CHOP + VP16), however, she had bone pain on November 1999 and received treatment with MCNU-VMP (MCNU + VDS + L-PAM + PSL). Her rib pain improved, but she died of systemic infection of herpes zoster virus. We report here a rare case of malignant lymphoma concomitant with multiple myeloma.

Aged↗
PubMed2001

[The significance of early detection for prostate cancer in mass screening].

PURPOSE: In Mitaka city, mass screening for prostate cancer was conducted for 3 years from 1995 to 1997. Clinical stages were compared between patients found by screening and those diagnosed at our clinic during the same time. The significance of serum-free prostate specific antigen (PSA) in mass screening for prostate cancer was examined. MATERIAL AND METHODS: A prospective clinical trial was conducted on men aged 50 years or older. The primary examination consisted of taking the international prostate symptom score, quality of life score, PSA (Tandem-R) and digital rectal examination (DRE). If PSA was greater than 4.0 ng./ml and/or if DRE suggested cancer, transrectal ultrasound-guided sextant prostate biopsies were indicated. RESULTS: Of the men screened, 23.2% (320/1375) had serum PSA greater than 4.0 ng./ml. and/or suspicious findings on DRE. Biopsy was performed in 199 of 320 (62.1%). Cancer was detected in 21 (1.5%, 21/1375). Prostate cancer was found in one case among 154 males (0.65%, 1/154) who were screened twice or more. The cancer stage found by screening was significantly earlier than that diagnosed at the outpatient clinic (Wilcoxon's rank-sum test: p = 0.0047). Receiver operating characteristics analysis showed that the optimal free PSA-to-PSA ratio was 12%. Positive predictive value increased from 18% to 50% when free PSA-to-PSA ratio was combined with PSA. CONCLUSION: 1. Cancer detection rate was 1.5% in the mass screening in Mitaka City. 2. Cancer stage found by screening was significantly earlier than that diagnosed at the outpatient clinic. 3. Free PSA determination might eliminate unnecessary biopsies in men with PSA above 4.0 ng./ml with minimal loss of cancer detection.

Aged↗
PubMed2001

[A case of recurrent convexity meningioma with malignant transformation 26 years after total tumor removal].

Meningiomas are common intracranial tumors, the majority of which are considered benign. However, they sometimes show altered biologic behavior, associated with local aggressiveness and late distant metastasis. We report a patient with a convexity meningioma, which recurred as a malignant transformation 26 years after a total tumor removal. A 75-year-old man was transferred to a local hospital because of general convulsions and left hemiparesis. The patient had had an operation for the total removal of a right frontal convexity meningioma at the age of 46 and had been free of its effects until the age of 72. Brain magnetic resonance imaging (MRI) showed a recurrent tumor located in the anterior area of the previous craniotomy. Over the following two and a half years, MRI revealed rapid enlargement and infiltration of the tumor into the brain parenchyma. The primary tumor was nodular, macroscopically well demarcated from the surrounding brain tissue and, histologically, was a transitional type of meningioma without any atypical features. In contrast, the recurrent tumor, whose border was ill-defined, had invaded the neighboring brain. A histological specimen of the recurrent tumor showed highly malignant features such as necrosis, intracerebral infiltration, dense cellularity, and high proliferating activity as demonstrated by a cell kinetic study using the MIB 1 staining index. We should be mindful that recurrence from common benign type meningiomas may occur as malignant transformations after more than two decades.

Aged↗
PubMed2001

[A case of suspected pulmonary air embolism in endoscopic neurosurgery].

Sudden reduction in end-tidal PCO2 and SpO2 occurred during the endoscopic third ventriculostomy in a patient with hydrocephalus under general anesthesia. We suspect that it was caused by pulmonary air embolism. A 63-year-old female was scheduled for endoscopic third ventriculostomy under general anesthesia. Endoscopic manipulation caused hemorrhage from chorioid plexus 21 minutes after the procedure was begun, and intraventricular irrigation was performed to achieve hemostasis. In the subsequent 3 minutes, end-tidal PCO2 declined from 26 mmHg to 15 mmHg (PaCO2 39.6 mmHg), and SpO2 declined from 98% to 92% (PaO2 69.2 mmHg). Nitrous oxide was discontinued immediately because pulmonary air embolism was suspected and the oxygen concentration was increased to 100%. At the same time the surgical procedure was discontinued. After 15 minutes, end-tidal PCO2 recovered to 25 mmHg, and SpO2 recovered to 98% (PaO2 136.5 mmHg), and surgery was resumed. The patient recovered from anesthesia. The chest X-p at the end of operation, and pulmonary scintigraphy on the following day revealed no abnormal findings, but brain CT demonstrated a large quantity of air in both lateral ventricles.

Embolism, Air↗
PubMed2001

Dendritic cell vaccination with MAGE peptide is a novel therapeutic approach for gastrointestinal carcinomas.

The MAGE gene is selectively expressed in cancer tissues such as melanoma or gastrointestinal carcinomas, whereas no expression is observed in normal tissues except testis. There are several reports of successful induction of HLA class I-restricted antitumor CTLs using MAGE peptides, and some clinical trials with these immunogenic peptides were reported as effective for some patients with malignant melanoma. However, there are no similar studies in gastrointestinal carcinomas, which are important neoplasms. Autologous dendritic cells (DCs) were generated ex vivo and were pulsed with MAGE-3 peptide, depending on the patient's HLA haplotype (HLA-A2 or A24). Patients were immunized with DC pulsed with MAGE-3 peptide every 3 weeks at four times. Twelve patients with advanced gastrointestinal carcinoma (six stomach, three esophagus, and three colon) were treated, and no toxic side effects were observed. Peptide-specific CTL responses after vaccination were observed in four of eight patients. Improvement in performance status was recognized in four patients. Tumor markers decreased in seven patients. In addition, minor tumor regressions evidenced by imaging studies were seen in three patients. These results suggested that DC vaccination with MAGE-3 peptide is a safe and promising approach in the treatment of gastrointestinal carcinomas.

Aged↗
PubMed2001

[Apical ballooning by transient left ventricular dysfunction (so-called "ampulla" cardiomyopathy) associated with therapy for acute pulmonary thromboembolism: a case report].

An 86-year-old-woman presented with apical ballooning left ventricular dysfunction associated with therapy for acute pulmonary thromboembolism. She was referred to our hospital for advanced treatment for her shock state due to acute pulmonary embolism with normal left ventricular(LV) function. Her condition was stabilized using a percutaneous cardiopulmonary support system. Suction embolectomy was successfully carried out after pulmonary arteriography. After the therapy, echocardiography revealed apical ballooning and hyperkinesis of the base(LV ejection fraction = 28%), although coronary arteriography showed no fixed stenosis. LV wall motion significantly improved on day 3(LV ejection fraction = 45%). Pulmonary embolism relapsed on day 5 in spite of anticoagulation treatment. She died of multiple organ failure on day 9. Autopsy findings indicated no sign of myocardial infarction or myocarditis, patchy appearance of myocardial contraction band necrosis and few migrated lymphocytes. The mechanism for the flow mis-matched LV dysfunction remains unknown. The probable explanations include non-ischemic stress such as catecholamine or neurogenic stress, and possibly ischemic stress or ischemia/reperfusion injury.

Aged↗
PubMed2001

[Treatment outcomes with vinorelbine for metastatic breast cancer patients previously treated with both doxorubicin and docetaxel].

The purpose of this study was to evaluate the efficacy and toxicity of weekly vinorelbine (VNB) in patients with metastatic breast cancer previously treated with both adriamycin (ADM) and docetaxel (TXT). VNB was administered weekly at the dose 20 mg/m2 by i.v. infusion over 20 minutes followed by flushing the vein with 100 ml of normal saline. From June 1999 to August 2000, ten patients were enrolled in this study. Patient characteristics were that the cumulative doses (median) of previous ADM and TXT were 300 mg (range, 120-880 mg), 560 mg (range, 120-960 mg) respectively. The median number of metastatic sites was four, with poor performance status (ECOG 1-2: 40%, 3-4: 60%). The median cycles of weekly VNB were seven (range: 2-12). Two of 10 assessable patients obtained partial response, with an overall response rate of 20%. The main toxicity (NCI grade 4) was leukopenia in 10% of 10 patients. Phlebitis (grade 2) was observed in 4 of 10 patients (40%). VNB is an active agent against metastatic breast cancer pretreated with both ADM and TXT, possessing no severe toxicities.

Adult↗
PubMed2001

[Therapeutic application for the aged with CML].

Therapeutic application for elderly CML patients had been restricted to use of alkylating or antimetabolite agents. In order to improve quality of life in the aged with CML interferon-alpha therapy is now first choice for treatment of elderly chronic phase of CML patients under appropriate informed consent. This treatment provided long term survival with cytological and cytogenetic responses even in the aged. In elderly patients attention has to be paid for the occurrence of side effects such as psychological changes. Further studies are on going in special reference to molecularly targeted therapy, i.e. a specific inhibitor of tyrosine kinase, or non-myeloablative stem cell transplantation.

Aged↗
PubMed2001

[Rapid quantitation of follistatin by surface plasmon resonance (SPR) immunoassay].

A simple, rapid, and accurate assay using surface plasmon resonance (SPR) apparatus with anti-follistatin antibody (SPR immunoassay) has been developed for the quantitation of recombinant follistatin. This assay can be performed with a direct injection of conditioned medium; results were obtained within 10 min. The quantitation component of this assay was precise and accurate with a limit of quantitation of 62.5 ng/ml in Ham's F12 medium containing 2% fetal bovine serum. These results demonstrate that SPR immunoassay is a powerful technique for several researches, especially for screening of gene transfectant and monitoring of protein production.

Activins↗
PubMed2001

[Study on evaluating methods for the quality control of glycoprotein products. (III)--Erythropoietin products. Part 3].

We reported previously that peptide mapping using high-performance liquid chromatography with electrospray ionization mass spectrometry (LC/MS) and liquid chromatography with tandem mass spectrometry (LC/MS/MS) are useful for determination of the glycosylation sites, carbohydrate structure, and site-specific carbohydrate heterogeneity of glycoproteins. Here, with intention to enhance the sensitivity and shorten the time-span of analysis to characterize glycoproteins, especially biotechnological products with carbohydrate moieties, we studied the introduction of HPLC with a microbore column to LC/MS with recombinant erythropoietin (rh-EPO). In addition, we evaluated the ability of LC/MS/MS precursor-ion scanning to make identification of glycopeptides and facilitate the analysis of carbohydrate moieties. We found that the peptide mapping with microbore HPLC is highly sensitive and more rapid than the previous method, and the precursor-ion scanning is helpful for identifying glycopeptides. Our results indicate that these methods are very useful for characterization and quality control of the carbohydrate moieties of biotechnological products.

Chromatography, High Pressure Liquid↗
PubMed2000

Selegiline and desmethylselegiline stimulate NGF, BDNF, and GDNF synthesis in cultured mouse astrocytes.

We investigated the effects of selegiline and desmethylselegiline on synthesis of neurotrophic factors in cultured mouse astrocytes. Treatment with 2 mM selegiline for 24 h increased the contents of NGF, BDNF, and GDNF in the culture medium 26-, 1.7-, and 4.2-fold over the control, respectively. With this drug the maximum relative mRNA levels of NGF, BDNF, and GDNF were 6.2-fold at 2 h, 3.4-fold at 6 h, and 2.7-fold at 2 h, respectively. Selegiline at 0.2 mM completely inhibited the MAO activity, but had no effect on the content of neurotrophic factors, suggesting that stimulation of neurotrophic factors by selegiline is independent of MAO-B inhibition. Desmethylselegiline at 1.68 mM for 24 h elevated the NGF, BDNF, and GDNF contents 4.1-, 1.7-, and 2.4-fold over the control, respectively; and the relative transcript levels of NGF, BDNF, and GDNF reached 2.6-fold at 2 h, 1.7-fold at 6 h, and 1.8-fold at 2 h, respectively. These findings suggest that selegiline and desmethylselegiline may protect neurons by up-regulating endogenous NGF, BDNF, and GDNF synthesis.

Amphetamines↗
PubMed2000

Molecular cloning and characterization of a new human histamine receptor, HH4R.

A new histamine receptor, HH4R, was cloned from human leukocyte cDNA. The deduced amino acid sequence showed about 40% identity to that of the human histamine H3 receptor, HH3R. HH4R-expressing cells responded to histamine, inhibiting forskolin-induced cAMP accumulation. An H3 agonist, N-alpha-methylhistamine (NAMHA), bound specifically to HH4R, while another H3 agonist, R(-)-alpha-methylhistamine (RAMHA), and the H3 antagonist, thioperamide, competed with this binding. RAMHA, NAMHA, and imetit inhibited forskolin-induced cAMP accumulation in HH4R-expressing cells. However, the binding affinities and agonistic activities of H3 agonists to HH4R were weaker than those to HH3R. Low expression of HH4R was detected in a wide variety of peripheral tissues by RT-PCR; however, in contrast with HH3R, expression was not detected in the brain. These observations indicate that the clone is a distinct histamine receptor from HH3R, and thus is named HH4R.

Amino Acid Sequence↗