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Biomedical subjects

Y Okabe

Publications and source records attributed to Y Okabe.

At least 55 records · Page 3Linked to original sources
PubMed1996

A chronic organized masseter abscess causing trismus resolved by hemi-masseter myotomy.

We present a 62-year-old patient with a chronic organized abscess of the right masseter muscle that developed following parotidectomy. This patient's chronic abscess originated from an infection in the masticator space from the second molar. Cases of repeated parotitis should lead one to suspect a masticator space infection. In this case, the cicatricical masseter muscle produced severe trismus. Total eradication of the abscess and myotomy of the masseter resolved the problem completely. We should pay attention to the dental condition in case of masticator space infection, especially in case of masseter muscle infection mimicking parotitis.

Abscess↗
PubMed1996

Synergistic growth stimulation of mouse fibroblasts by tumor-derived adhesion factor with insulin-like growth factors and insulin.

Tumor-derived adhesion factor (TAF) has been purified as a major secretory protein with cell-adhesion activity from culture medium conditioned by human bladder carcinoma cells (K. Akaogi et al., Biochem. Biophys. Res. Commun., 198: 1046-1053, 1994). TAF is closely related or identical to a putative protein encoded by the mac25 gene (M. Murphy et al., Cell Growth & Differ., 4: 715-722, 1993) and prostacyclin-stimulating factor (T. Yamauchi et al., Biochem. J., 303: 591-598, 1994). TAF has a characteristic cysteine cluster in its NH2-terminal sequence, which is conserved in the NH2 termini of insulin-like growth factor-binding proteins. In the present study, we examined the interaction of TAF with insulin-like growth factors (IGFs) and insulin. Although in a ligand blotting assay TAF bound neither IGFs nor insulin, immunoprecipitation assay showed weak interaction of TAF with IGF-I, IGF-II, and insulin. TAF by itself stimulated the growth of BALB/c3T3 cells on the usual plastic substrates and significantly enhanced IGF- or insulin-mediated cell growth. Moreover, marked potentiation of the mitogenic activities of IGFs and insulin by TAF was found in the culture on type IV collagen substrates. The synergistic growth stimulation was completely blocked by heparin. These results suggest that TAF may regulate the growth of fibroblastic cells in collaboration with IGFs and insulin.

3T3 Cells↗
PubMed1995

Selective minimum-norm solution of the biomagnetic inverse problem.

A new multidipole estimation method which gives a sparse solution of the biomagnetic inverse problem is proposed. This solution is extracted from the basic feasible solutions of linearly independent data equations. These feasible solutions are obtained by selecting exactly as many dipole-moments as the number of magnetic sensors. By changing the selection, we search for the minimum-norm vector of selected moments. As a result, a practically sparse solution is obtained; computer-simulated solutions for Lp-norm (p = 2, 1, 0.5, 0.2) have a small number of significant moments around the real source-dipoles. In particular, the solution for L1-norm is equivalent to the minimum-L1-norm solution of the original inverse problem. This solution can be uniquely computed by using Linear Programming.

Animals↗
PubMed1995

Development of high frequency vestibulo-ocular responses to active head shaking.

Computer aided active head shaking test has several advantages because it can be used clinical at frequencies higher than 2 Hz. In this study, VOR gain and phase were examined over age. For this experiment, we designed an original measurement system composed of EOG, an angular velocity sensor and a microcomputer. VOR gain was expressed by transfer function. Forty normal subjects ranging from 10 to 75 were examined for high frequency VOR responses to active head shaking. VOR gain at frequencies higher than 2 Hz attained the same value as that seen in children below the age of 10 years. The VOR gain was nearly 1 within 2 Hz, decreasing with frequencies above 4 Hz. The effect of aging was shown at frequencies of more than 4 Hz, and appeared in patients above 50 years of age. No obvious phase lag was observed within 5 Hz.

Adolescent↗
PubMed1995

[MMIP chemotherapy for the treatment of the relapsed and refractory non-Hodgkin's lymphoma].

For salvage chemotherapy, 30 cases of relapsed or refractory non-Hodgkin's lymphoma (NHL) were treated with MMIP regimen (mitoxantrone 15 mg/m2, methotrexate 400 mg/m2, and ifosfamide 2 g/m2 intravenously in day 1, respectively, and prednisolone 20 mg/m2 orally from day 1 to 5). The overall complete response rate (CR rate) was 20% and the median survival duration was 153 days. In patients with favorable performance status (PS), the CR rate and survival duration were 30% and 407 days, respectively. These results were almost equivalent to previously proposed salvage regimens. The overall disease free survival rate of CR cases at 4 years was 62%, which was excellent as compared with the other salvage regimens. Five of 8 (62.5%) patients previously treated with etoposide-non-containing regimens achieved CR, and the CR rate was significantly superior to that of patients previously treated with etoposide-containing ones. These results indicate that MMIP is a useful salvage regimen for relapsed or refractory NHL, while it seems to be difficult to salvage patients previously treated with etoposide-containing regimens.

Adult↗
PubMed1994

Cell adhesion activity of a 30-kDa major secreted protein from human bladder carcinoma cells.

Human bladder carcinoma cell line EJ-1 secreted a protein of 30 kDa as a major component. This protein was purified from the serum-free conditioned medium of EJ-1. Its N-terminal amino acid sequence was identical to that of fibroblast-derived endothelial cell growth factor (f-ECGF), but there were differences in their amino acid compositions and isoelectric points. The 30-kDa protein showed no effect on the growth of bovine capillary endothelial cells, but it promoted the attachment and spreading of rat liver cell line BRL and human umbilical vein endothelial cell line ECV-304. These results suggest that the 30-kDa protein, tentatively named "tumor-derived adhesion factor (TAF)", may be related with the aberrant cell adhesion of cancer cells.

Amino Acid Sequence↗
PubMed1994

Plasma and leukemic cell pharmacokinetics of high-dose N4-behenoyl-1-beta-D-arabinofuranosylcytosine in acute leukemia patients.

The pharmacokinetics of N4-behenoyl-1-beta-D-arabinofuranosylcytosine (BHAC), a lipophilic antitumor analog of 1-beta-D-arabinofuranosylcytosine (ara-C), was investigated, by assay of plasma and leukemic cells of ten acute leukemic patients receiving 60-minute intravenous (IV) infusion of 700 mg/m2 BHAC, for BHAC and 1-beta-D-arabinofuranosylcytosine 5'-triphosphate (ara-CTP) by high-performance liquid chromatography, ara-C by radioimmunoassay, and 1-beta-D-arabinofuranosyluracil (ara-U) by gas chromatography-mass fragmentography. The plasma concentration of BHAC reached a maximum (173.4 +/- 75.3 micrograms/mL) at the end of the infusion and then declined in a biphasic pattern with an initial-phase half-life (t1/2 alpha) of 1.00 +/- .36 hours and a second-phase half-life (t1/2 beta) of 4.28 +/- 2.35 hours. That of ara-C similarly reached a maximum (102.2 +/- 39.9 mg/mL) at the end of the infusion and then declined with t1/2 alpha of 1.37 +/- 1.11 hours and t1/2 beta of 11.2 +/- 4.31 hours. Intracellular ara-CTP concentration increased in a linear-accumulation manner for the first 4 hours after the infusion, reached a maximum of .081 +/- .112 micrograms/10(7) cells at approximately 7 hours, and then declined very slowly in accordance with a one-compartment model with t1/2 of 13.56 +/- 9.62 hours.

Antineoplastic Agents↗
PubMed1994

Importance of pre-operative recognition of the nonrecurrent laryngeal nerve.

The nonrecurrent laryngeal nerve is vulnerable during thyroid surgery. Pre-operative recognition of this nerve allows surgeons to avoid injuring the nerve. This anomaly depends upon the aortic arch anomaly and, therefore, in some cases, surgeons are able to predict the presence of this nerve pre-operatively by chest X-ray or barium swallow. Two patients with nonrecurrent laryngeal nerve are reported, one of whom, a 48-year-old man, had an abnormal shadow of the aortic arch, which led to confirmation of a right aberrant subclavian artery. Barium swallow plays a decisive role in the diagnosis of nonrecurrent laryngeal nerve, and this test is mandatory in patients who complain of difficulty in swallowing.

Abnormalities, Multiple↗
PubMed1994

Primary T cell non-Hodgkin's lymphoma of the central nervous system. Case report and review of the literature.

A 42-year-old man developed primary non-Hodgkin's lymphoma of the central nervous system (CNS). Immunohistochemical examination suggested that tumor cells were derived from T cells. Primary T cell non-Hodgkin's lymphoma of the CNS is a rare tumor, with only 12 well-documented cases in the literature. The clinical features of these 12 cases were similar to those of other CNS lymphomas, and the effect of treatment and prognosis were usually worse than those of extranodal lymphoma. Our patient, who was treated with partial tumor resection and whole-brain irradiation with a boost to the primary site and 5 courses of CHOP therapy (cyclophosphamide, doxorubicin, vincristine, prednisolone), is still alive and in remission 38 months after diagnosis.

Adult↗
PubMed1994

No mutation in cytochrome P450 side chain cleavage in a patient with congenital lipoid adrenal hyperplasia.

Molecular basis of lipoid adrenal hyperplasia (lipoid CAH) in a Japanese patient was investigated. A 46XY Japanese female patient was clinically diagnosed as having lipoid CAH based on her clinical history of adrenal crisis at birth and the low basal concentrations of cortisol, aldosterone, adrenal androgens and testosterone in serum. In vitro studies of testicular mitochondrial enzymes confirmed a specific impairment of cholesterol side chain cleavage (SCC) activity. However, in spite of the virtual reduction of SCC activity, the amounts of immunodetectable P450scc, adrenodoxin reductase, and adrenodoxin in testicular mitochondria were almost same as those of normal testis. Furthermore, the size of each protein was similar to that of normal testis. Enzymatic amplification of the complementary DNA encoding P450scc from the patient's testis RNA and its nucleotide analysis by direct sequencing revealed no mutation. These results indicate that defective P450scc is not the lesion in this patient, confirming a previous report showing no P450scc mutations in patients with lipoid CAH. The exact lesion causing lipoid CAH in this patient is currently unknown.

Adolescent↗
PubMed1994

[Cochlear implant in a child with congenital severely impaired hearing].

A 6-year 9-month-old child with congenital severely hearing impaired received a Nucleus 22 channel implant. Twenty-two CG electrodes are now in use. In the 5 months since the cochlear implant, the patient has made good progress. Her vowel discrimination score has reached 100%. However, her consonant discrimination has remained at the chance level. On the other hand, auditory reception of environmental sounds has shown relative improvement. Problems encountered in pediatric use of the cochlear implant are also discussed herein.

Child↗
PubMed1994

[Small nodular lesions of the pancreas: differential diagnosis with ultrasound angiography].

Ultrasound angiography (USAG), sonographic imaging of the blood flow in an organ or tissue obtained by carbon dioxide infusion into the supplying artery, was performed on 28 pancreatic nodular lesions less than 3 cm in diameter. The hemodynamics of tumors observed with USAG were divided into three groups: hypovascular, isovascular, and hypervascular, compared with the adjacent pancreatic tissue. Most of hypovascular nodules were duct cell carcinoma (sensitivity 94.1%, specificity 90.4%), while isovascular lesion was the characteristic of inflammatory masses (sensitivity 100%, specificity 95.8%). Hypervascular cases included all of the mucin producing tumors and islet cell tumors but only one case of duct cell carcinoma. So you can almost exclude duct cell carcinoma as an diagnosis in vascular rich tumors (negative predictive value 83.6%). These results were compared with those on conventional x-ray angiograms and incremental CT scans. Ultrasound angiography enabled us to detect more slight differences of tumor vascularity than the other modalities. Thus we conclude that USAG can be a useful diagnostic aid in small mass lesions of the pancreas.

Adenocarcinoma, Mucinous↗
PubMed1993

Hemolytic uremic syndrome developing during remission of acute myelomonocytic leukemia.

A 47-year-old woman was diagnosed with acute myelomonocytic leukemia (AMMoL) and was treated with combination chemotherapy. After one cycle of remission induction therapy, she entered into complete remission and then received three cycles of consolidation therapy. A month after the last consolidation therapy, she was diagnosed with having the complication of chemotherapy-related HUS (C-HUS). The C-HUS improved after initiation of plasma exchange and antiplatelet therapy. In the present case, it seems that the antileukemic agents might play an important role in the development of C-HUS.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Prevention of doxorubicin-induced cardiotoxicity by recombinant interleukin-1 in hamsters. Doxorubicin cardiotoxicity and interleukin-1.

The major factor contributing to doxorubicin (DXR)-induced cardiotoxicity is the insufficiency of antioxidant defense mechanisms. As a model of acute cardiotoxicity with DXR, ten-week-old golden hamsters were given DXR (5 mg/kg) intravenously, and the toxicity was investigated by monitoring ECG changes. Complete A-V block and cardiac arrest on the ECG were observed in DXR-treated hamsters. DXR-induced edema and fragmentation of myofibrils were observed by electron-micrograph. Pretreatment with interleukin-1 beta (10 or 1 microgram/body) 12 or 24 hrs before prevented these changes, but pretreatment with tumor necrosis factor alpha had no effect.

Animals↗
PubMed1993

Effect of vagotomy on ornithine decarboxylase activity in rat duodenal mucosa.

The aim of this study was to determine whether the circadian rhythm of ornithine decarboxylase (ODC) activity in rat small intestine is controlled by factors other than luminal nutrients. ODC activity in duodenal and jejunal mucosa of rats fed ad libitum was measured at four time points (0500, 1100, 1700, 2300 h; light period: 0800-2000 h). ODC activity in the jejunum increased in the dark period, which is when rats normally eat. In contrast, ODC activity in the duodenum began to increase at 1700 h, which is when rats do not normally eat, as indicated by the recorded feeding pattern. The increase in ODC activity in the duodenum at 1700 h, but not at other time points, was abolished by subdiaphragmatic vagotomy, whereas vagotomy had no effect on the feeding pattern of rats. Subdiaphragmatic vagotomy had no effect on ODC activity in the jejunum. ODC activity in the duodenum increased following glycoprivation of the central nervous system induced by infusion of 2-deoxyglucose into the third cerebroventricle. These results indicate that the increase in duodenal ODC activity at 1700 h is due to a signal from the upper brain structure through the vagal nerve and not to luminal nutrient factors.

Animals↗
PubMed1992

The association of hypopituitarism with small pituitary, invisible pituitary stalk, type 1 Arnold-Chiari malformation, and syringomyelia in seven patients born in breech position: a further proof of birth injury theory on the pathogenesis of "idiopathic hypopituitarism".

We report seven cases of hypopituitarism all having a history of breech delivery, asphyxia at birth, and syringomyelia. A small pituitary gland was found on MRI or CT in six cases, invisible pituitary stalk on MRI in five cases, and type 1 Arnold-Chiari malformation in six cases. A constellation of these abnormalities are best explained by traction of brain and spinal cord of the subjects exerted during breech delivery and further support the primary role of birth trauma in the genesis of "idiopathic hypopituitarism".

Adolescent↗