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Biomedical subjects

A Kawashima

Publications and source records attributed to A Kawashima.

At least 91 records · Page 5Linked to original sources
PubMed1998

Eicosapentaenoic acid inhibits mitogen-induced endothelin-1 production and DNA synthesis in cultured bovine mesangial cells.

The present study was designed to examine whether eicosapentaenoic acid (EPA) inhibits the production of basal or stimulated endothelin (ET)-1 by platelet-derived growth factor (PDGF)-BB or epidermal growth factor (EGF), and DNA synthesis in cultured bovine mesangial cells. PDGF-BB and EGF stimulated ET-1 secretion in a dose-dependent fashion in these cells. EPA (10-100 microM) exhibited dose-related inhibition of PDGF-BB- and EGF-stimulated ET-1 secretion. EPA had no inhibitory effects on basal ET-1 secretion in these cells. Moreover, 50 microM EPA significantly attenuated PDGF-BB- and EGF-stimulated [3H]thymidine incorporation into mesangial cells. Receptor-binding experiments showed that EPA competitively inhibited 125I-PDGF-BB or 125I-EGF binding to mesangial cell surface receptors. Scatchard analysis for PDGF-BB receptor or EGF receptor revealed a linear regression fit and one binding site. Pretreatment with 50 microM EPA suppressed the number of maximum binding sites, but did not affect the Kd values. These results indicate that EPA potentially inhibits mesangial cell ET-1 production, when stimulated by PDGF-BB or EGF. This inhibitory effect of EPA could be related to the attenuation of mesangial cell proliferation via inhibition of the binding of PDGF-BB or EGF to their receptors due to alteration of the physicochemical characteristics of the cell membrane.

Animals↗
PubMed1998

Plasma concentration of brain natriuretic peptide as an indicator of cardiac ventricular function in patients on hemodialysis.

The plasma concentration of human brain natriuretic peptide (BNP) was measured by immunoradiometric assay in patients on maintenance hemodialysis (HD) to assess the possible relationship between the plasma levels of this peptide and cardiac ventricular function, as judged by M-mode echocardiography. The plasma BNP levels in the pre-HD state were significantly higher (688.5 +/- 154.5 pg/ml) than those of healthy subjects (<40 pg/ml). In addition, the plasma BNP levels were slightly decreased during HD (post-HD, 617.3 +/- 157.1 pg/ml). There was no correlation between the plasma levels of BNP and body weight changes during HD. The mean plasma BNP level was significantly higher in the group of patients with a low left ventricular ejection fraction (EF < 60%) than in the group with a normal EF. In the patients as a whole, there was an inverse correlation between plasma BNP levels and EF. Moreover, a positive correlation was found between plasma BNP levels and left ventricular mass index (r = 0.57, p < 0.05). These results suggest that plasma BNP levels increase in response to chronic stimulation in accordance with increased cardiac load, and that they may be a possible indicator of reduced ventricular function in HD patients.

Atrial Natriuretic Factor↗
PubMed1998

Spontaneous pneumomediastinum: origin identified by chest computed tomography.

Spontaneous pneumomediastinum (SPM) is an uncommon disorder. The mechanism of spontaneous pneumomediastinum has been speculated as follows: when air pressure in the alveoli rapidly increases, free air leaks from ruptured alveoli and accumulates along the bronchovascular tissue sheath, and then free air moves toward the mediastinum. In this case report of a 19-year-old man of SPM, a chest computed tomography (CT) revealed air in a tubular shape along the pulmonary artery in the apico-posterior segment of the left lung field. This is the first case in which the process of SPM could be identified by chest CT.

Adult↗
PubMed1998

Acute pulmonary edema caused by accidental aspiration of sweetened water in two cases of diabetes mellitus.

We treated two cases of diabetes mellitus who developed acute pulmonary edema following accidental aspiration of sweetened water for emergency treatment, when they had fallen into hypoglycemic coma following an overdose of injectable insulin. Although they showed hypoxemia and radiological examinations revealed pulmonary edema, they improved by giving only oxygen and antibiotics in a few days. The osmotic pressure of the sweetened water in each case was approximately 2,600 mOsm and 1,900 mOsm. We suppose that the pathogenesis of the pulmonary edema was due to the sweetened water causing water within the pulmonary vessels to permeate into the alveoli.

Acute Disease↗
PubMed1998

Squamous odontogenic tumor of the maxilla: report of a case.

A case of squamous odontogenic tumor (SOT) of the maxilla related to an embedded tooth in a 42-year-old Japanese woman is described. The patient felt a slight pain of her left maxilla 2 months before visiting our dental hospital. Histologically, the tumor consisted of a proliferation of round and elongated epithelial islands of well-differentiated squamous epithelium separated by a fibrous stroma. The epithelial nests varied in size, and were composed of cuboidal or squamous cells of basal layer and matured intermediate cells with prominent intercellular bridges. Although no calcified materials were found, microcystic degeneration was occasionally observed in the epithelial islands. These findings indicated that this tumor is a SOT of the maxilla.

Adult↗
PubMed1998

Persistent distension and enhanced diffusive extravasation of tumor vessels improved uniform tumor targeting of radioimmunoconjugate in mice administered with angiotensin II and kininase inhibitor.

Induced hypertension with angiotensin II (AT-II) and the inhibition of kininase with enalapril maleate may increase the tumor targeting of radiolabeled monoclonal antibodies (MAbs). We previously found that short-period infusion of 2.0 microg/kg/min of AT-II enhanced tumor targeting of MAb without an impact on normal tissue distribution. In this study, we aimed to optimize the manipulation with these agents, and examine the possible mechanism of their effects on MAb distribution. Effect of the manipulation on tissue circulation was assessed in mice bearing colon cancer xenografts by 201Tl and 99mTc-human serum albumin (HSA) as markers of tissue blood flow and tissue blood volume and/or vascular permeability. A dose finding study of enalapril ranging from 3 to 300 microg showed that 30 microg of enalapril in combination with AT-II infusion produced the best improvement in tumor uptake of 99Tc-HSA without altering 201Tl distribution, suggesting that the increase of vascular permeability was caused by enalapril. AT-II infusion for longer than 1 h affected renal blood flow and caused subcutaneous edema. Tumor uptake of (111)In-A7, a murine IgG1, was 1.62-fold improved 72 h postinjection (P < 0.001) and intratumoral distribution became uniform with 2.0 microg/kg/min of AT-II for 1 h and 30 microg of enalapril. Vessels in manipulated tumors were distended even 48 h after the cessation of AT-II infusion. In conclusion, it was suggested that persistent distension of tumor vessels and the increase of diffusive extravasation of MAb caused by short-period-induced hypertension and inhibition of bradykinin degradation produced favorable effect for the MAb distribution in tumors.

Angiotensin II↗
PubMed1998

[Efficacy of nicardipine prolonged-release pellet on cerebral vasospasm in dogs].

A drug delivery system using copoly (lactic/glycolic acid) was developed for the intrathecal administration of nicardipine. This system was tested to determine its efficacy in preventing cerebral vasospasm in dogs. A rod-shaped implant (1-mm diameter, 10-mm long and which contained approximately 10% of nicardipine) was prepared by a heat compression method. In in vitro studies, 8% of the actual nicardipine loaded was released during day 1, 17% within day 2, 62% within day 4, and 96% within day 10. In in vivo studies, 12 dogs were assigned to two groups: the placebo group and the group treated with nicardipine. Angiography before the experiment was performed followed by right craniectomy and induction of subarachnoid hemorrhage by the placement of a clot in the Sylvian fissure. Eight pellets, either containing 8 mg of nicardipine or without nicardipine were placed in the cistern. On day 7, the angiography was repeated and cerebrospinal fluid was removed from the cisterna magna. The animals were then sacrificed, and the brain and blood clot were taken out. Cerebral vessels were measured three times with a calibrated optical micrometer, and the mean value was obtained. Average reduction of vessel diameters on the clot side in the placebo and nicardipine groups were -37% and -10% on the internal carotid (IC), -48% and -3% on the middle cerebral (MC), and -28% and -1% on the anterior cerebral artery (AC), respectively. There were significant differences in vessel diameters of IC (p < 0.05), MC (p < 0.005), and AC (p < 0.05) between these groups. No vasospasm was found in the left side. The nicardipine concentration in the clot was determined by high performance liquid chromatography. The mean concentration of nicardipine in the clot was 1.5 x 10(-4)M, at which concentration sufficient relaxation is evoked in vitro. The pellets did not last beyond day 7. Regarding the histological findings, there was a marked difference in vessel diameters between the placebo and the nicardipine treated groups. The arteries were surrounded with red blood cells and inflammatory cells. There were no specific changes related to the pellets and no sign of meningoencephalitis. A prolonged-release preparation of nicardipine that can be implanted intracranially at the time of surgery prevented vasospasm significantly in dogs. These results suggest that this new drug delivery system might be put into effect favorably in patients suffering from vasospasm due to subarachnoid hemorrhage.

Animals↗
PubMed1997

RET proto-oncogene is important for the development of respiratory CO2 sensitivity.

Brain stem muscarinic cholinergic pathways are important in respiratory carbon dioxide (CO2) chemosensitivity. Defects in the muscarinic system have been reported in children with congenital/developmental disorders of respiratory control such as sudden infant death syndrome (SIDS) and congenital central hypoventilation syndrome (CCHS). This early onset of disease suggests a possible genetic basis. The muscarinic system is part of the autonomic nervous system which develops from the neural crest. Ret proto-oncogene is important for this development. Thus, a potential role for ret in the development of respiratory CO2 chemosensitivity was considered. Using plethysmography, we assessed the ventilatory response to inhaled CO2 in the unanesthetized offsprings of ret +/- mice. Fractional increases in minute ventilation during hypercapnia relative to isocapnia were 5.1 +/- 3.2, 3.0 +/- 1.6 and 1.4 +/- 0.8 for the ret +/+, ret +/- and ret +/- mice, respectively. The ret knockout mice have a depressed ventilatory response to inhaled CO2. Therefore, the ret gene is an important factor in the pathway of neuronal development which allow respiratory CO2 chemosensitivity.

Animals↗
PubMed1997

Undifferentiated (anaplastic) carcinoma of the pancreas showing sarcomatous change and neoplastic cyst formation.

CONCLUSION: Pancreatic undifferentiated (anaplastic) carcinoma contained two components: sarcomatous change of spindle-cell type and a neoplastic cyst. Immunohistochemical analysis suggested that both the sarcomatous and the cystic portions were of epithelial origin. This case showed a "dual" differentiation both into the sarcomatous change and into the cystic lesion. BACKGROUND: Pancreatic sarcoma or sarcomatous change is very rare. The origin of sarcomatous change is unknown. On the other hand, pancreatic adenocarcinoma sometimes shows necrosis and forms a cystic lesion during its growth, but a neoplastic cyst formation is very rare except for cystadenomas. METHODS: We report a case of pancreatic undifferentiated (anaplastic) carcinoma associated with sarcomatous change and neoplastic cyst formation. Clinicopathological and immunohistochemical analyses were performed. RESULTS: A 75-yr-old male was admitted because of low back pain and body weight loss. He died 7 d after admission presenting obstructive jaundice. Autopsy disclosed that the large mass was a poorly differentiated ductal adenocarcinoma, which mostly consisted of sarcomatous components of spindle-cell type. The cystic lesion was a neoplastic cysts with the wall composed of epithelial tumor cells. There was no necrosis or hemorrhage in the cystic cavity. Immunohistochemical analyses suggested that both the tumor and the cystic lesion were of epithelial origin. Sarcomatous changes were recognized also in the metastatic lesions in the liver and lymph nodes. The tumor is considered to be labeled undifferentiated (anaplastic) carcinoma of the pancreas.

Aged↗
PubMed1997

Anti-mitogenic effects of sarpogrelate in cultured rat mesangial cells.

We investigated the effects of the new 5-HT2A receptor antagonist, sarpogrelate, on DNA synthesis in renal mesangial cells stimulated with 5-HT in the presence and absence of platelet-derived growth factor (PDGF)-BB. Both 5-HT and PDGF-BB demonstrated a mitogenic effect on these cells. When mesangial cells were incubated in the absence of PDGF-BB, sarpogrelate inhibited DNA synthesis in these cells in a dose-dependent manner. In the presence of PDGF-BB, sarpogrelate had a weaker anti-mitogenic effect in mesangial cells stimulated with 5-HT. Sarpogrelate was cytotoxic at concentrations over 10(-5) M according to the results of LDH release assays, and it reduced the S1 phase in mesangial cells stimulated with 5-HT by a flow cytometry. These findings suggest that sarpogrelate may be effective in the treatment of some glomerulonephritis associated with mesangial cell proliferation.

Animals↗
PubMed1997

Antepartum bilateral ovarian vein thrombosis: magnetic resonance imaging diagnosis.

Antepartum cases of ovarian vein thrombosis are extremely rare and often misdiagnosed. A 22-year-old nullipara at 29 weeks' gestation presented with right lower quadrant pain and fever. Sonography revealed a tubular, hypoechoic mass. At laparotomy, a noninflamed appendix was found and a 2 x 4 cm retroperitoneal mass was palpated near the right ureter. Postoperative magnetic resonance imaging (MRI) revealed bilateral thrombosis of the ovarian veins with caval extension. Therapeutic anticoagulation was achieved, but the patient underwent cesarean delivery 4 days later due to active labor and malpresentation. Postoperative MRI showed no extension of the thrombi, and her postpartum course was otherwise unremarkable. MRI is a valuable, noninvasive tool in the diagnosis of venous thrombi in pregnancy.

Adult↗
PubMed1997

Ureteropelvic junction injuries secondary to blunt abdominal trauma.

PURPOSE: To describe the clinical and imaging findings of ureteropelvic junction (UPJ) injuries caused by blunt trauma. MATERIALS AND METHODS: In two children (aged 10 and 16 years) and eight adults (aged 23-82 years) with UPJ injuries, findings at computed tomography (CT) (n = 10), excretory urography (n = 6), and retrograde pyelography (n = 8) were retrospectively reviewed to identify the location and extent of contrast material extravasation. Clinical and follow-up data were correlated with radiologic findings. RESULTS: CT and urography played complementary roles in diagnosis. UPJ avulsion, defined as complete transection of the ureter with no filling of the ipsilateral ureter below the level of the UPJ, was diagnosed in four patients. UPJ laceration, defined as contrast material extravasation from the UPJ with contrast material in the ipsilateral ureter distal to the point of injury, was diagnosed in six patients. Medial perirenal contrast extravasation was seen in all 10 patients but failed to help differentiate UPJ avulsion from laceration. A distinctive pattern of contrast material extravasation at CT termed "circumrenal urinoma" was present in five patients and was found to be specific for UPJ injury. CONCLUSION: Medial perinephric contrast material extravasation was highly suggestive of UPJ injury. Demonstration of ureteral filling differentiated UPJ laceration from avulsion.

Abdominal Injuries↗
PubMed1997

Effect of varying amino acid levels on protein metabolism in nephrotic rats during total parenteral nutrition.

In an attempt to determine appropriate diet in nephrotic syndrome, nephrotic rats, induced by puromycin aminonucleoside, were nourished by total parenteral nutrition fluid containing the same energy, but three different levels (1.65, 3.3, and 6.6%) of amino acids for 7 d. The fractional rate of total protein synthesis in the liver was determined by injecting a flooding dose of [3H]phenylalanine. The proportion of newly synthesized proteins retained and exported by the liver was estimated by injecting a tracer dose of [14C]leucine and then measuring the protein radioactivity remaining in the liver and present in the plasma after secretion was completed. Nephrotic animals synthesized more protein than control animals. Although the absolute synthesis rates of total protein in liver were increased with increasing amino acid administration, the absolute rates of synthesis of albumin were higher in the 3.3% group than in the other groups in nephrotic rats. However, kidney protein synthesis in nephrotic rats was higher in the 1.65% group than in the 3.3% group. Interestingly, the 3.3% group revealed the smallest urinary excretion of total protein and albumin. In addition, in the 3.3% group, plasma concentrations of total protein and albumin were higher, and plasma concentrations of total cholesterol and triglyceride were lower than in other groups. It was concluded that the 3.3% group, corresponding to a normal protein diet, has the greatest salutary effect on urinary protein excretion, followed by protein and lipid metabolism, in nephrotic rats. Not only protein intake but also the energy:protein ratio are important for diet therapy in nephrotic animals. The technique of total parenteral nutrition may be useful in defining the factors involved in glomerular permeability or permselectivity and intracellular protein metabolism.

Amino Acids↗
PubMed1997

Unenhanced helical CT of ureterolithiasis: value of the tissue rim sign.

OBJECTIVE: The tissue rim sign-a rim or halo of soft-tissue attenuation seen around the circumference of an intraureteral calculus on unenhanced axial CT-has been described as useful in differentiating ureteral calculi from extraurinary abdominal or pelvic calcifications. The purpose of this study was to determine the prevalence of the tissue rim sign in patients with ureterolithiasis and extraurinary calcifications and to determine the relationship between the tissue rim sign, the size of a calculus, and the degree of urinary obstruction. MATERIALS AND METHODS: Unenhanced helical CT studies followed by excretory urography were obtained in 59 patients with suspected acute ureterolithiasis. Each calcification along the expected course of the ureter seen on axial CT scans was categorized as a ureteral calculus or as an extraurinary calcification. Each categorization was based on CT, urographic, and clinical findings and the presence or absence of a tissue rim sign. When the outer wall of the ureter could not be seen because there was no clear fat plane at the level of the calcification on CT, the sign was categorized as "indeterminate." The size of the calculus was measured on CT, and the degree of urinary obstruction was estimated on the basis of the urograms. RESULTS: Thirty-two patients each had a single ureteral calculus. Of these patients, CT revealed a positive tissue rim sign in 16 patients (50%), was negative in five patients (16%), and was indeterminate in 11 patients (34%). In addition, we saw 57 extraurinary calcifications in 18 patients (11 patients with ureteral calculi and seven patients without ureteral calculi). None of the 57 extraurinary calcifications was associated with a positive tissue rim sign. The tissue rim sign was negative in 39 (68%) of the 57 extraurinary calcifications and indeterminate in the remaining 18 (32%). Ureteral calculi with a negative tissue rim sign were larger than ureteral calculi with a positive tissue rim sign (p < .01). A high degree of obstruction was present in four of five patients with ureteral calculi for which CT showed a negative tissue rim sign. Conversely, six of 16 patients in whom CT revealed a positive tissue rim sign also had a high degree of obstruction. Therefore, no clear relationship was found between the degree of obstruction and the presence of a positive tissue rim sign. CONCLUSION: A positive tissue rim sign is specific for the diagnosis of ureterolithiasis. However, a negative tissue rim sign does not preclude such a diagnosis. The presence or absence of this tissue rim sign correlates with the size of a calculus but not with the degree of urinary obstruction. When CT reveals an indeterminate tissue rim sign, careful inspection for other CT findings, such as ipsilateral ureteral dilatation, perinephric edema, dilatation of the intrarenal collecting system, and renal swelling, is necessary.

Acute Disease↗
PubMed1997

A case of hemangiopericytoma of the buccal mucosa.

We report a 46-year-old woman who presented with a hemangiopericytoma in the buccal mucosa. At the 2-year postoperative examination, there was no evidence of recurrence or metastasis. The findings in the present case are compared with previous reports in the Japanese literature, with regard to patient age and sex, and lesion size, location, malignancy, local recurrence and metastasis.

Endothelium, Vascular↗
PubMed1997

[Stone recurrence after stone free status with extracorporeal shock wave lithotripsy].

BACKGROUND: The objects of this study is to evaluate the ipsilateral stone recurrence who became stone free status after extracorporeal shock wave lithotripsy (ESWL). METHODS: Three hundred ninety five patients who became stone free after ESWL with Lithostar and followed more than 6 months, were analyzed stone recurrence. Stone recurrence were diagnosed by KUB and/or ultrasound. Actual recurrence free rate were calculated based on the period from the day of achieved stone free status to the day of estimated recurrence. Eight factors examined included sex, side, number, location, size, stone history urological complication, hydronephrosis and also contralateral recurrence was analyzed. RESULTS: Over all ipsilateral recurrence free rate were 96.5%, 78.8%, 65.3% after 1, 3 and 5 years, respectively. Contralateral stone free rate were 98.1%, 92.5%, 87.2% after 1, 3 and 5 years. Five-year recurrence free rate according stone factors, there were significant difference in stone number (Single 71.1% and multiple 31.6%), in stone history (with history 77.1% and without 35.7%), in urological complication (without complication 67.7% and with complication 35.7%). However, there were no significant difference in sex, side, stone, location, stone size and hydronephrosis. CONCLUSION: This results suggested that the stone number, stone history and urological complication were highly related to ipsilateral stone recurrence after stone free status by ESWL. Extracorporeal shock was lithotripsy had probability of higher stone recurrence rate.

Adolescent↗
PubMed1997

Immunolocalization of matrix metalloproteinases and tissue inhibitors of metalloproteinases in human chondrosarcomas.

We have immunohistochemically examined the localization of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in human chondrosarcomas (CHS) (23 cases) and benign chondroid lesions (BCL) (16 cases of osteochondromas and 11 cases of enchondromas). In CHS, all the MMPs and TIMPs examined were positive. Among them, MMP-1 was immunolocalized in more than 90% of both CHS and BCL, but positive score of MMP-1 was significantly higher in CHS than that in BCL (p < 0.01). Compared with BCL, CHS expressed MMP-3 at a low level, and more often positive in MMP-9. It is possible that chondrosarcoma might have a tendency to lose the ability to secrete MMP-3, which is a metalloproteinase that can degrade cartilage proteoglycans and is related to normal cartilage turnover. MMP-2, TIMP-1 and TIMP-2 were immunolocalized in more than 70% of the cases of both BCL and CHS, but the positive scores of these were not statistically different between the two groups. Interestingly, in several cases of CHS, both MMP-1 and MMP-9 immunostains were observed preferentially within the cells at the marginal areas of cartilaginous lobules. These findings suggest that increased expression of MMP-1 and MMP-9 and decrease in MMP-3 expression are associated with the malignant phenotype of the cartilaginour tumors.

Adult↗