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Biomedical subjects

T Ohsawa

Publications and source records attributed to T Ohsawa.

At least 19 recordsLinked to original sources
PubMed1996

All-trans retinoic acid increases peptidylarginine deiminases in a newborn rat keratinocyte cell line.

We studied the expression of peptidylarginine deiminases (EC 3.5.3.15) in an immortalized newborn rat keratinocyte cell line. No measurable enzyme activities were noted in either growing or confluent cultures. The enzyme activity was increased by all-trans retinoic acid in dose- and time-dependent manners. The enzyme activity was resolved into two peaks by anion exchange chromatography. The minor peak resembled enzyme preparations obtained from the epidermis in earlier studies. The major peak was indistinguishable from rat muscle peptidylarginine deiminase in the chromatographic and Western blotting profiles. Northern blot hybridization showed a major band in retinoic acid-treated cells migrating slightly behind muscle peptidylarginine deiminase mRNA.

Animals↗
PubMed1996

[A case of inflammatory pseudotumor of the lung with suppressed immune response in the patient with renal cell carcinoma after nephrectomy and administration of interferon].

A 60-year-old man with renal cell carcinoma was treated of right nephrectomy and high dose administration of Interferon-alpha (IFN) in 1990. Three and half years after operation, he complained of cough and hemoptysis. Chest X-ray showed a abnormal shadow (5.5 x 3.5 cm) in the upper lung field. On chest CT, a tumor mass with small cavity was located at S2, attended with the speculation and pleural indentation. A rough nodule suspected daughter tumor was pointed out near the tumor mass. Laboratory investigation revealed mild leucocytosis, an elevated ESR and C reactive protein. On lymphocyte subset, CD 4/8 ratio was 0.8 and NK cell activity was 11%. Immunosuppressive acid protein (IAP) in serum was 1,137 ng/ml. No organisms or malignant cells could be demonstrated in the biopsy materials or sputum. Right thoracotomy and upper lobectomy was carried out. Postoperative pathological diagnosis was inflammatory pseudotumor. Namely, the lesion was occupied with variable admixture of lymphocytes, plasma cells, histiocytes, phagocytes included hemosiderin, foam cells and whorled fibrosis. Daughter tumor was scar tissue. Now, he is well without recurrence and his immune response is within normal level. Some discussion of the literature was mentioned.

Autoimmune Diseases↗
PubMed1995

[A successfully treated case of thoracoabdominal aortic aneurysm complicated with the coagulation disorder].

We could performed the safe operation for thoracoabdominal aortic aneurysm complicated with pre-DIC. A diagnosis of pre-DIC was made by laboratory data. Low heparin pretreatment was performed for the short term because we presumed the cause for pre-DIC was thromboses in aneurysm. That treatment was effective for the temporal remission of pre-DIC. In addition, during partial ECC low heparin (1 mg/kg) and nafamostat mesilate (2 mg/kg/h) were used. As a result, during and after the operation blood loss was a little. In summary heparin pretreatment is useful therapy for DIC and pre-DIC in aortic aneurysm patients.

Aged↗
PubMed1995

Experimental infection of juvenile Biomphalaria glabrata with cercariae of Echinostoma trivolvis.

Infectivity studies were done on laboratory-reared Biomphalaria glabrata juvenile (neonatal) snails exposed to cercariae of Echinostoma trivolvis. Of the 40 snails, 0.7-1.0 mm in shell diameter, which were exposed to a total of 1,000 cercariae for 24 hr, all were infected with 1-29 viable encysted metacercariae per snail. Biomphalaria glabrata, 1-2 mm in shell diameter, were used to determine the effects of an infectious dose of 25 cercariae/juvenile on subsequent snail survival. The median survival time of 24 exposed snails occurred between day 3 and 4 postinfection, at which time more than 90% of 24 control (unexposed) snails were alive. The high mortality in the E. trivolvis-infected B. glabrata juveniles was probably related to cercarial penetration and encystment in the snail tissue, although histological examination of snails after exposure would be required to determine the actual cause of the observed mortality.

Animals↗
PubMed1994

Carpal tunnel syndrome: evaluation of median nerve circulation with dynamic contrast-enhanced MR imaging.

PURPOSE: To identify mechanism(s) responsible for carpal tunnel syndrome (CTS). MATERIALS AND METHODS: At dynamic gadolinium-enhanced magnetic resonance (MR) imaging, the enhancement pattern of the sagittal section of the median nerve in 10 wrists of nine patients with CTS (two men and seven women, aged 43-60 years [mean, 52 years 10 months]) was studied while each wrist was in a neutral, flexed, and/or extended position. Five asymptomatic volunteers (four men and one woman, aged 23-54 years [mean, 31 years 5 months]) also underwent MR imaging to establish the normal enhancement patterns. RESULTS: Two distinctly abnormal patterns of median-nerve enhancement were revealed: marked or no enhancement. Marked enhancement was attributed to nerve edema, and the lack of enhancement was attributed to ischemia. Marked enhancement changed to no enhancement changed to no enhancement when the wrists were in a flexed or extended position. This change was associated with an aggravation of the symptoms of CTS. CONCLUSIONS: CTS may result from a circulatory disturbance rather than from deformation or compression of the nerve.

Adult↗
PubMed1994

Triangular fibrocartilage in asymptomatic subjects: investigation of abnormal MR signal intensity.

PURPOSE: To investigate the prevalence of abnormally high signal intensity of triangular fibrocartilage (TFC) tears on magnetic resonance (MR) images of asymptomatic subjects. MATERIALS AND METHODS: MR images of one wrist in 70 asymptomatic volunteers (age range, 15-78 years) were evaluated for TFC high signal intensity. Findings at MR imaging and topographic parameters of each wrist studied were correlated with the subject's age. Any vertical or horizontal high-intensity slits that reached the joint surface or evidence of a perforation was considered abnormal. RESULTS: Abnormally high TFC signal intensity was seen on images of 35 (50%) wrists. Further, a thin TFC was more often seen in subjects with positive variance, and positive ulnar variance and thin TFC were associated with high signal intensity. Age did not substantially affect the presence or absence of high signal intensity. CONCLUSION: Since TFC high signal intensity was frequently detected in these asymptomatic wrists, MR imaging cannot reliably be used to detect clinically meaningful abnormalities.

Adolescent↗
PubMed1994

Focal obliteration of the descending aortic interface on normal frontal chest radiographs: correlation with CT findings.

PURPOSE: To assess the frequency, location, correlation with age, and cause of partial obliteration of the descending aortic interface on normal frontal chest radiographs. MATERIALS AND METHODS: Concurrent chest radiographs and computed tomographic (CT) scans of 1,500 patients in whom CT findings excluded a diagnosis of paraaortic pathologic processes were reviewed retrospectively. RESULTS: Aortic interface obliteration was identified on 134 images (8.9%), which included 43 (2.9%) in the suprahilar and upper hilar portion, 56 (3.7%) in the lower hilar portion, and 46 (3.1%) in the cardiac portion of the interface. The causes were direct contact with or proximity to the aortic margin by pulmonary arteries at the suprahilar and upper hilar portion, superior segment vessels at the lower hilar portion, and various structures, including left inferior pulmonary vein, mediastinal fat, and left ventricle at the cardiac portion. CONCLUSION: Partial aortic interface obliteration can be seen on normal frontal chest radiographs because of obstruction by small adjacent structures.

Adolescent↗
PubMed1994

Ulnar collateral ligament in the growing elbow: MR imaging of normal development and throwing injuries.

PURPOSE: To study the magnetic resonance (MR) imaging appearance of the ulnar collateral ligament (UCL) and its insertion into the medial epicondyle. MATERIALS AND METHODS: Sixteen normal and 20 symptomatic elbows were examined with a 1.5-T unit. Normal elbows were imaged with axial T2*-weighted three-dimensional Fourier transform sequences. Symptomatic elbows were imaged with coronal T1-, T2-, and T2*-weighted and/or short-inversion-time inversion-recovery sequences. RESULTS: In normal immature elbows, the ulnar periosteum was seen as an extension of the UCL, and its enthesis had signal intensity characteristics that differed from those of the mature ligament. In symptomatic elbows imaged before epiphyseal fusion, segmentation and subchondral bone resorption of the ossification center were seen with or without a capsular tear. After epiphyseal fusion, a full-thickness or a partial UCL tear at the site of its insertion, with or without subcortical bone resorption, was seen. CONCLUSION: The MR imaging characteristics of the developing elbow differ from those of the mature elbow. MR imaging is useful in assessing UCL damage.

Adolescent↗
PubMed1994

Unilateral hyperlucent thorax on plain chest radiographs after neck dissection: importance of atrophy of the trapezius muscle.

OBJECTIVE: A hyperlucent thorax on plain chest radiography indicates a decrease in the radiographic density of the thorax, which can be caused by intra- or extrapulmonary diseases. The purpose of this study was to assess the prevalence and mechanisms that may be responsible for unilateral hyperlucency of the thorax after neck dissection and to determine if atrophy of the trapezius due to the transection of the accessory nerve is a cause of hyperlucent thorax. MATERIALS AND METHODS: Differences in the radiographic density between the right and left lung were evaluated and correlated with transection of the accessory nerve in 21 patients who had had a radical or a modified neck dissection for a malignant tumor of the head and neck. Twenty-eight neck dissections were performed on these 21 patients (seven had a simultaneous bilateral neck dissection). In 14 of the 21 patients, the accessory nerve had been severed during the neck surgery. In six patients, mechanisms responsible for a hyperlucent thorax were investigated with follow-up thoracic CT scans. RESULTS: In the radiographs, eight patients had a hyperlucent thorax on the side of the neck dissection. In all of these cases, the accessory nerve on the side of this neck dissection had been severed during a radical or a modified neck dissection. Prior to surgery, no such hyperlucency was noted. CT scans showed atrophy of the denervated trapezius muscle. CONCLUSION: Our findings show that atrophy of the denervated trapezius muscle after neck dissection is a cause of unilateral hyperlucent thorax on plain chest radiographs. Therefore, this finding should be anticipated as a postoperative change in patients who have had this surgery.

Accessory Nerve↗
PubMed1994

Results of combined resection of invaded organs in patients with potentially curable, advanced gastric cancer.

OBJECTIVE: To assess the role of combined resection of neighbouring organs that have been invaded by cancer in patients with potentially curable, but advanced, gastric cancer. DESIGN: Retrospective follow up study. SETTING: University department of surgery. SUBJECTS: 204 patients (from a consecutive series of 745 who had had gastric resection for cancer) all of whom had undergone potentially curative operations for advanced disease: 91 had had combined resection of other invaded organs. RESULTS: Five year survival was 65% for 113 patients who had gastrectomy alone and 46% for 91 patients who also had other affected organs resected (p < 0.02). CONCLUSION: We recommend resection of all organs that have been invaded by cancer, provided that there is no evidence such as widespread nodal involvement, peritoneal dissemination, or extensive hepatic metastases, that would make cure impossible.

Diaphragm↗
PubMed1993

Anti-B-series ganglioside-recognizing autoantibodies in an acute sensory neuropathy patient cause cell death of rat dorsal root ganglion neurons.

To examine the cytotoxicity of a patient's serum with an acute relapsing sensory neuropathy syndrome, dorsal root ganglion neurons from young adult rats were cultured in the presence of the patient's serum which had an extremely higher-titer monoclonal IgM antibody recognizing B-series gangliosides, GD2, GD1b, GT1b and GQ1b. By the addition of the inactivated patient's serum, the relatively larger cells died after undergoing of metamorphosis during several hours of culture, whilst the smaller cells survived. The IgM fraction isolated from the patient's serum showed similar cytotoxicity towards the neurons as the inactivated whole serum. No cytotoxicity was observed with the IgM fraction-containing medium after it had been absorbed with ganglioside GD1b. The results suggested that the anti-B-series ganglioside-directed antibody is the causal agent for the human neurologic disease.

Acute Disease↗
PubMed1993

[Ankylosing spondylitis with acute anterior uveitis--correlation between HLA-B27 and clinical and radiologic findings].

Six cases of ankylosing spondylitis (AS) complicated with acute anterior uveitis (AAU) were reviewed. Clinical and radiologic findings of these cases were correlated with HLA-B27. All the patients were men; four of them were HLA-B27 positive, and two were B27 negative. The average age of onset was younger in B27+ patients than in B27- patients. Ophthalmologic study showed no definite difference in inflammatory change of AAU between B27+ patients and B27- patients. AAU in B27+ patients was completely cured in three months. A history of low back pain was more apparent in B27+ than in B27- patients. Three out of four B27+ patients showed complete bony ankylosis in sacroiliac joints, whereas no ankylosis was seen in B27- patients. CT scan was useful to demonstrate sacroilitis in cases with equivocal radiologic findings. Spondylitic changes were more extensive in B27+ than in B27- patients. The results support the concept that HLA-B27+ AS and B27- AS are different entities with similar phenotypic expression, and HLA-B27 is an arthritogenic gene in the Japanese population as well.

Acute Disease↗
PubMed1993

Similar responses to pharmacological agents of 1,2-OAG-induced compaction-like adhesion of two-cell mouse embryo to physiological compaction.

A comparison was made of responses to pharmacological agents between cell adhesion induced by an activator of Ca(2+)-phospholipid-dependent protein kinase (PKC) and physiological compaction in mouse embryos. An activator of PKC, 1-oleoyl-2-acetyl-sn-glycerol (1,2-OAG) induced the compaction-like adhesion of cells in two-cell embryos within 5-10 min and the adhesion lasted during the course of treatment for 1 h. W-7 and W-5 (calmodulin antagonists) and cytochalasin B and cytochalasin D (inhibitors of the polymerization of microfilaments) each completely interfered with the 1,2-OAG-induced adhesion of cells. Two-cell embryos having once shown evidence of cell adhesion in response to 1,2-OAG were decompacted when they were transferred to a medium that contained 1,2-OAG and any one of the agents described above. Colchicine and colcemid (inhibitors of the polymerization of microtubules) and tunicamycin (an inhibitor of N-linked protein glycosylation) each had no effect on the 1,2-OAG-induced adhesion of cells. In Ca(2+)-free medium, treatment with 1,2-OAG failed to induce any cell adhesion. These results are very similar to those reported for physiological compaction at the late eight-cell stage. Thus, the compaction-like adhesion of cells in mouse embryos at the two-cell stage appears to be a calmodulin-dependent process, requiring assembled microfilaments and extracellular Ca2+ ions but not microtubules or N-linked glycoproteins as is the case for the physiological compaction.

Animals↗
PubMed1993

Involvement of protein kinase C in nuclear migration during compaction and the mechanism of the migration: analyses in two-cell mouse embryos.

Compaction and nuclear migration occur in mouse embryos at the late eight-cell stage. It has been reported that activators of protein kinase C (PKC) increase adhesion of cells at the two-cell, four-cell, and uncompacted eight-cell stage. We report here that nuclear migration followed the increased adhesion of cells in such embryos when they were treated with PKC activators. These cellular events resembled those in normal embryos at the late eight-cell stage and were blocked by sphingosine, a PKC inhibitor. The responses were proportional to the dose of the PKC activator. Molecular analogues of the PKC activators, which do not affect PKC, did not induce these events. These results suggest an important role for PKC in initiation of nuclear migration as well as in compaction. Experiments were also conducted to identify the source of the mechanical force that moves the nucleus. Nuclear migration was suppressed in embryos pretreated with colchicine. Calmodulin is known to have effects on Ca(2+)-induced assembly and disassembly of microtubules. The calmodulin antagonists W-7 and W-5 suppressed nuclear migration. These results suggest that microtubules are essential for the migration and that nuclei are migrated via the Ca(2+)-induced, calmodulin-mediated assembly and disassembly of the microtubule networks. Together, these results obtained with PKC activators/inhibitor, colchicine, and calmodulin antagonists suggest that nuclear migration is mediated by increases in PKC activity, requires intact microtubules, and is accompanied by PKC-dependent increases in cell-cell adhesion.

Animals↗
PubMed1993

Susceptibility effects of bone trabeculae. Quantification in vivo using an asymmetric spin-echo technique.

RATIONALE AND OBJECTIVES: The authors assessed the capability of magnetic resonance imaging in measuring bone mineral density in vivo. METHODS: Using the in-phase asymmetric spin-echo technique, the susceptibility effect (T2*susceptibility) was measured in lumbar vertebrae in vivo. Calcium density was measured with single energy quantitative computed tomography scan. The values of the susceptibility effect were correlated with calcium density. RESULTS: A statistically significant positive correlation was observed between signal loss due to susceptibility-induced inhomogeneity and the calcium density in the region of interest. The change in 1/T2*susceptibility per unit change in density was 0.114 seconds-1/mg/cm3. T2*susceptibility was 14.3 mseconds in volunteers and 17.4 mseconds in postoophorectomy patients. CONCLUSIONS: To some extent, quantification of bone density is possible using magnetic resonance imaging; however, the relatively wide dispersion of the susceptibility effect, plotted against the calcium density in the axial skeleton, indicates that other factors, such as the three-dimensional structure of bone trabeculae, may play important roles in determining magnetic resonance parameters.

Adult↗
PubMed1993

Frequent presence of anti-GQ1b antibody in Fisher's syndrome.

We used the enzyme-linked immunosorbent assay to investigate autoantibodies against the gangliosides GM1, GD1a, GD1b, GT1b, GD2, and GQ1b in sera from 16 patients with Fisher's syndrome. We found high anti-GQ1b antibody titers, mainly those of the IgG class, in the sera of 13 of these patients. The titers decreased with the clinical course of the illness. Moreover, anti-GQ1b antibody-positive patients had more severe ataxia of cerebellar type than the antibody-negative patients.

Adult↗