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Biomedical subjects

M Fukui

Publications and source records attributed to M Fukui.

At least 343 records · Page 19Linked to original sources
PubMed1995

Cholesterol granuloma in the middle cranial fossa: report of two cases.

We report two cases of cholesterol granuloma in the middle cranial fossa. On CT the lesions appeared as a nonspecific, nonenhancing soft-tissue mass with bone erosion. On MRI they were seen as areas of high signal intensity surrounded by a low-intensity peripheral zone on both T1- and T2-weighted images. Cholesterol granuloma is thought to occur when pneumatised cells in the temporal bone become obstructed. Although this lesion usually occurs in the petrous bone, it can extend to the middle cranial fossa. The diagnosis and surgical management are discussed.

Adult↗
PubMed1995

Chemotherapy for progressive pilocytic astrocytomas in the chiasmo-hypothalamic regions.

Over the past 25 years, we have treated 17 patients with chiasmo-hypothalamic astrocytomas. Before 1988, the initial treatments consisted of surgery and/or radiotherapy, while since 1989, 4 children (1 male, 3 females, aged 3-8 years) were treated primarily with chemotherapy. None of them was associated with neurofibromatosis. After a biopsy of the tumor, the intravenous administration of ranimustine (MCNU; 30-86 mg/m2) and/or nimustine (ACNU; 30.3-64.1 mg/m2) was given without radiation therapy. Chemotherapy was usually given as an out-patient, with a total of 5-13 courses. The total doses of MCNU and ACNU administered ranged from 150 to 570 mg and from 64.8 mg to 100 mg, respectively. After chemotherapy 2 patients showed clinical improvement and tumor regression on neuro-imaging, while one patient showed clinical improvement and tumor size stabilization on neuro-imaging. The remaining one child, however, showed a clinical worsening and tumor progression on neuro-imaging studies. He was thus treated with a second chemotherapy regimen with carboplatin and etoposide, which brought about tumor regression. The acute and subacute toxicity of chemotherapy was mild. All patients are now leading almost normal lives with a median of 43 months after diagnosis. Although a longer and more careful clinical observation is required, the authors conclude that chemotherapy with MCNU and/or ACNU may benefit patients with unresectable pilocytic astrocytoma requiring treatment. The advantages of this therapy include its mild side effects and the lack of any hospitalization in most patients. It may also delay the need for radiation therapy, which can have a deleterious effect on the young developing brain.

Antineoplastic Agents↗
PubMed1995

Oxygen transport and hemodynamics during retrograde whole-body perfusion.

The changes in oxygen transport and hemodynamics during retrograde whole-body extracorporeal perfusion (retro-ECC) were studied in six mongrel dogs. Oxygen consumption during retro-ECC, in which the blood flow rate was set at 25% and 50% of the flow during antegrade extracorporeal perfusion (ante-ECC), respectively, was relatively high compared with that during ante-ECC. These changes were caused by an increase in the oxygen extraction ratio to 71.5% +/- 8.2% and 51.2% +/- 12.4% during retro-ECC/25% and retro-ECC/50%, respectively. Thus, tissue perfusion was apparently well maintained by retrograde perfusion on the basis of the oxygen transport data. However, central venous pressure increased markedly to 29.5 +/- 11.6 mmHg and 56.2 +/- 24.5 mmHg during retro-ECC/25% and retro-ECC/50%, respectively, because of massive venous congestion caused by insufficient arterial return of perfused blood. The great venous compliance and increased systemic vascular resistance were the main causes of circulatory failure during retro-ECC. The risk of serious complications owing to the venous congestion must be considered during retrograde perfusion, especially during the clinical application of retrograde cerebral perfusion.

Animals↗
PubMed1995

Effects of a low-protein diet on glomerular endothelin family gene expression in experimental focal glomerular sclerosis.

1. The present study was designed to assess whether glomerular expression of mRNAs for endothelin-1 and endothelin-3, as well as endothelin receptors A and B is affected by a low-protein diet during the course of focal glomerular sclerosis. 2. Focal glomerular sclerosis was induced in rats by injection of puromycin aminonucleoside on days 0, 27, 34 and 41 in conjunction with unilateral nephrectomy on day 22. Control rats were subjected to nephrectomy or sham operation on day 22. 3. Animals were divided into six groups. In group 1, the puromycin aminonucleoside-injected rats were fed a standard diet containing 22% protein. In group 2, the puromycin aminonucleoside-injected rats were fed a low-protein diet containing 6% protein, which was initiated on the day of the first puromycin aminonucleoside injection. In group 3, the nephrectomized rats without puromycin aminonucleoside were fed a standard diet. In group 4, the nephrectomized rats without puromycin aminonucleoside were fed a low-protein diet. In group 5, the sham-operated rats were fed a standard diet. In group 6, the sham-operated rats were fed a low-protein diet. 4. The percentage of sclerotic glomeruli in group 1 rats increased markedly with time, reaching 77% on day 80. 5. The glomerular mRNA levels for endothelin-1 and endothelin receptors A and B increased significantly as glomerular sclerosis progressed, whereas no endothelin-3 mRNA was detected in the glomeruli of any group. The endothelin-1 production in isolated glomeruli from group 1 increased significantly as glomerular sclerosis progressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Cutaneous metastasis of CNS chordoma.

A rare case of cutaneous skin metastasis from an intracranial chordoma is presented. A large nodule developed in the left thigh of a 22-year-old woman who had been previously diagnosed to have a chordoma at the base of her skull. Sections from the biopsied specimens of the nodule showed proliferations of physaliphorous cells and stellate cells in cords and in nests in a myxoid stroma. Immunohistochemically, neoplastic cells were stained positively with antibodies to S-100 protein and cytokeratin. The results of the histopathological and immunohistochemical studies of the nodule were interpreted as pointing to a diagnosis of metastatic chordoma based on their similarity to the results of studies of the primary neoplasm in the cranial region. Based on the number of cases of skin metastasis from chordoma reported in the literature, skin should be kept in mind as one of the target organs, although such metastases are still rare.

Adult↗
PubMed1995

Pharmacokinetic study of valproic acid sustained-release preparation in patients undergoing brain surgery.

Pharmacokinetics of valproic acid sustained-release preparation (VPA-SR) were studied in nine patients undergoing surgery for brain tumor. Total (t) and free (f) serum concentrations were analyzed in samples drawn during the day of brain surgery and compared with levels from a postoperative day. The area under the curve (AUCt) and clearance (CLt) of the total concentration did not differ on these occasions. In contrast, statistically significant differences were observed in AUCf and CLf between the two occasions; increased AUCf and decreased CLf were observed on the day of surgery. A significant relation was found between the average free fraction (AUCf/AUCt on operation day per AUCf/AUCt on postoperative day) and estimated blood loss during operation (r = 0.82; p < 0.001). In addition, a significant relation was found between simple free fraction and the intraoperative albumin level in serum (r = -0.68; p < 0.001). These findings indicate that the increased VPA free concentration is due to low serum albumin level secondary to blood loss and that there has been a decrease in intrinsic clearance during operation.

Adolescent↗
PubMed1995

Proliferative activity and apoptosis of Langerhans histiocytes in eosinophilic granulomas as evaluated by MIB-1 and TUNEL methods.

Aims-To identify the role played by apoptosis in tumour regression.Methods-The growth fraction and apoptotic cell loss of four cases of eosinophilic granuloma were investigated using monoclonal antibodies against Ki-67 proliferation marker (MIB-1) antigen and the TdT mediated dUTP-biotin 3'-OH nick end labelling (TUNEL) method. These data were then compared with the clinical growth rate.Results-Only the Langerhans histiocytic cells, which reacted positively with anti-S-100 protein antibody, were immunolabelled with antibodies to proliferating cell nuclear antigen and Ki-67 antigen (MIB-1). Many apoptotic figures of histiocytic cells were also detected in all cases by the TUNEL method. In a patient whose tumour clinically showed spontaneous regression, the TUNEL staining index gave a higher score than the MIB-1 staining index.Conclusions-The main cause of the spontaneous regression of the tumours was postulated to be programmed cell death (apoptosis).

Journal Article↗
PubMed1995

Resting load regulates vascular sensitivity by a cytosolic Ca(2+)-insensitive mechanism.

The cellular mechanism underlying the regulation of the contraction of vascular smooth muscles by resting load is unknown. To determine the effects of changes in the resting load on vascular sensitivity to high K+ and to 9,11-dideoxy-11 alpha, 9 alpha-epoxy-methanoprostaglandin F2 alpha (U-46619), the force and cytosolic calcium concentration ([Ca2+]i) of arterial strips were recorded at resting loads of 200 (optimal load), 50, and 10 mg. A decrease in the resting load elicited a small decrease in the basal [Ca2+]i level without affecting the extent of maximal [Ca2+]i elevation induced by either stimulus. Through a decrease in the resting load, the concentration-response curves for the force development of high K+ or of U-46619 shifted to the right, whereas those for [Ca2+]i did not. We conclude that the basal [Ca2+]i level and the force development, but not the agonist-induced [Ca2+]i signals, of vascular smooth muscles depend on the resting load. We response that the resting load regulates the sensitivity of vascular smooth muscles, irrespective of types of stimuli, through a [Ca2+]i-insensitive mechanism.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1995

Primary intracranial squamous cell carcinomas: report of two cases.

Two cases of primary intracranial squamous cell carcinomas are reported. The first patient is a 57-year-old man with an epidermoid carcinoma in the right cerebellopontine angle, having histological features that indicated malignant transformation in a benign epidermoid cyst. The second patient is a 42-year-old man in whom squamous cell carcinoma arose in a pre-existing middle fossa dermoid cyst 9 years after the initial surgical resection. The literature on primary intracranial squamous cell carcinomas is reviewed, and the clinical features and histological pathogenesis for the occurrence of this unique condition are discussed.

Adult↗
PubMed1995

Cell damage and liberation of nitric oxide synthase in rat heart induced by endotoxin administration.

To evaluate the relationship between cardiovascular injury and the pathological aspect of the liberation of the nitric oxide synthase in endotoxin shock, Wistar rats were injected intraperitoneally with 10 mg/kg E. coli endotoxin and the cardiovascular changes were observed chronologically by immunohistochemical and electron microscopic techniques at 2, 4, 8 and 12 h respectively after endotoxin administration. Light microscopically, irregular contraction of cardiomyocytes was observed in the early stage. After 8 h of endotoxin administration, occasional disintegration of the myocytes as well as lysis of myofibrils became prominent, and diminished stainings of myoglobin and actin were seen in these myocytes. Ultrastructurally, increased pinocytotic vesicles were observed in endothelial cells associated with widened intercellular spaces, and vacuolization of endothelial and medial cells of the vasculature. In cardiomyocytes, swelling of mitochondria and interstitial edema were noted at 12 h after endotoxin administration. Immunohistochemically, an increased permeability of albumin was noted in the myocytes and vasculature and nitric oxide synthase was localized on the cytomembrane of the endothelium of the coronary arteries in control rats. After endotoxin administration, the reaction products of nitric oxide synthase increased in the endothelial and medial cells, and cardiomyocytes. These results suggest that the increased activity of nitric oxide synthase is an important factor in the excessive production of nitric oxide and in promoting the pathologic changes in the cardiovascular system after endotoxin administration.

Animals↗
PubMed1995

Mechanical ventilation may not be essential for initial cardiopulmonary resuscitation.

BACKGROUND: In a rodent model of cardiac arrest and resuscitation in which the inspired gas mixture was enriched with oxygen, resuscitability and survival were unaffected by positive pressure ventilation. In the present study, in a larger animal model, tidal volumes generated during precordial compression and with spontaneous gasping were quantitated. METHODS: Domestic pigs with an average weight of 34 kg were anesthetized with pentobarbital. Ventricular fibrillation (VF) was induced electrically. Precordial compression was begun after 4 min of untreated VF. Each of 22 animals received one of two interventions in conjunction with precordial compression: positive pressure ventilation with oxygen or oxygen supplied at the port of a tracheal tube at ambient pressure. After 8 min of precordial compression, defibrillation was attempted. RESULTS: Only very moderate increases in arterial PCO2 were documented during cardiopulmonary resuscitation in the absence of mechanical ventilation but arterial oxygen tension was consistently in excess of 100 mm Hg. Cardiac resuscitability and 48-h survival were approximately the same in animals maintained on inspired oxygen whether or not they were mechanically ventilated (7/11 or 8/11). In the absence of mechanical ventilation, precordial compression and spontaneous gasping yielded minute volumes that exceeded 5 L. CONCLUSION: Positive pressure mechanical ventilation did not improve resuscitability or postresuscitation outcome in this porcine model of cardiac arrest.

Animals↗
PubMed1995

Airway protection during experimental CPR.

BACKGROUND: Experimental studies recently demonstrated that positive pressure ventilation may not be essential for initial cardiopulmonary resuscitation. Nevertheless, oxygen enrichment of inspired gas mixtures and spontaneous gasping were associated with increased resuscitability and survival after cardiac arrest. However, as yet unresolved is the benefit of early airway control under conditions simulating "sudden death" due to ventricular fibrillation. METHODS: Twenty adult, male Sprague-Dawley rats were randomly assigned to one of two groups in which the airway was unprotected or protected by an oropharyngeal airway of our design. Cardiac arrest was induced by an alternating current delivered to the right ventricular endocardium. Oxygen was delivered to a hood that was loosely applied over the head of the each animal at a flow rate of 1 L/min. Precordial compression was initiated after 4 min of untreated ventricular fibrillation and defibrillation was attempted 6 min later. After spontaneous circulation had been restored, a tracheostomy was performed and the animals were mechanically ventilated with 100% oxygen for an additional interval of 1 h. Animals were then returned to their cages and observed for an additional 24 h. RESULTS: Spontaneous circulation was restored in each of the animals who had an oropharyngeal airway and nine of ten animals in the absence of an artificial airway. In each group, seven animals survived for more than 24 h. Animals in which the airway had been protected had significantly greater frequency of spontaneous gasping (28 +/- 13/min vs 13 +/- 9/min; p < 0.05) and significantly higher arterial oxygen saturation (77 +/- 19% vs vs 55 +/- 25%; p < 0.05). CONCLUSION: In the setting of experimental cardiac resuscitation, the insertion of an artificial airway increased the frequency of spontaneous gasping and arterial oxygenation. Nevertheless, no significant differences in resuscitability or postresuscitation survival were associated with insertion of the artificial airway.

Airway Obstruction↗
PubMed1995

Enalapril attenuates increased gene expression of extracellular matrix components in diabetic rats.

This study was designed to assess whether the glomerular expression of mRNA for extracellular matrix (ECM) components including alpha 1 (I), alpha 1 (III), and alpha 1 (IV) collagen chains, laminin B1 and B2 chains, metalloproteinases (MMP), and tissue inhibitor of metalloproteinases (TIMP) is affected by enalapril in 12- and 24-wk-old rat after streptozotocin injection. Animals were divided into three groups; untreated diabetic rats, enalapril-treated diabetic rats, and control rats. Enalapril treatment was continued for 24 wk. Enalapril reduced both creatinine clearance (P < 0.01) and urinary protein excretion (P < 0.01) in diabetic rats. In diabetic rats, mRNA levels for alpha 1 (IV) collagen chain, laminin B1 and B2 chains, and alpha 1(I) and alpha 1(III) collagen chains increased significantly at 24 wk compared with those in controls [alpha 1(IV): 3.8-fold (P < 0.01); laminin B1: 6.2-fold (P < 0.01); laminin B2:5.4-fold (P < 0.01), alpha 1(i): 4.8-fold (P < 0.01) and alpha 1(III): 3.8-fold (P < 0.01)]. At 24 wk, mRNA levels for MMP-1 and MMP-3 fell to 40% (P < 0.01) and 20% (P < 0.01), respectively, in the glomeruli of diabetic rats compared with levels in controls. In contrast, mRNA levels for TIMP-1 and TIMP-2 increased significantly at 24 wk after streptozotocin injection (TIMP-1: 8.0-fold (P < 0.01) and TIMP-2: 6.4-fold (P < 0.01)).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Modulation of glomerular endothelin and endothelin receptor gene expression in aminonucleoside-induced nephrosis.

This study assessed glomerular endothelin (ET)-1, ET-3, and ET-receptor A and B mRNA levels in puromycin aminonucleoside (PAN)-induced nephrosis. During the nephrotic stage, 8 days after PAN injection, ET-1 and ETB receptor mRNA were elevated by 2.8 +/- 0.8-fold (P < 0.01) and 2.4 +/- 0.9-fold (P < 0.01), respectively, as compared with controls. These mRNA levels decreased to control levels by Day 20, when the nephrosis was in remission. In contrast, glomerular ETA receptor mRNA levels did not change in PAN nephrosis or control rats during the experimental period. ET-3 mRNA was not detected in the glomeruli of PAN nephrosis or control rats. Additionally, plasma ET concentration and glomerular ET production were measured in PAN nephrosis and control rats by radio-immunoassay. Eight days after PAN injection, ET-1 levels in plasma and glomeruli were not significantly altered in rats with PAN-induced nephrosis (glomeruli, 104.68 +/- 16.46 pg/mg of protein versus 98.24 +/- 13.68 pg/mg of protein; plasma, 2.68 +/- 1.10 versus 2.52 +/- 0.98 pg/mL). The administration of methylprednisolone to PAN rats resulted in the rapid disappearance of proteinuria and partially attenuated the increased ET-1 and ETB receptor gene expression in the glomeruli. These data indicate that glomerular ET-1 and ETB receptor expression in PAN nephrosis in increased at the mRNA level and that methylprednisolone treatment results in an attenuated increase.

Animals↗
PubMed1995

Effect of a specific endothelin receptor A antagonist on mRNA levels for extracellular matrix components and growth factors in diabetic glomeruli.

We have previously reported that the mRNA levels of extracellular matrix (ECM) components including alpha 1(I), alpha 1(III), and alpha 1(IV) collagen chains, laminin B1 and B2 chains, and growth factors including tumor necrosis factor (TNF)-alpha, platelet-derived growth factor (PDGF)-B chain, transforming growth factor (TGF)-beta, and basic fibroblast growth factor (FGF) all increase with age in diabetic glomeruli. The present study was designed to assess whether glomerular expression of these mRNAs in rat diabetic glomeruli is affected by a specific endothelin receptor A antagonist, FR139317. Diabetes was produced by streptozotocin injection, and animals were divided into four groups: untreated diabetic rats, FR139317-treated diabetic rats, control nondiabetic rats, and FR139317-treated control rats. FR139317 treatment was continued for 24 weeks. FR139317 attenuated the rise in creatinine clearance (P < 0.01) and reduced urinary protein excretion (P < 0.01) in diabetic rats, but did not affect blood pressure. FR139317 attenuated the increases in glomerular mRNA levels of alpha 1(I) (P < 0.01), alpha 1(III) (P < 0.01), and alpha 1(IV) (P < 0.01) collagen chains, laminin B1 (P < 0.01) and B2 (P < 0.01) chains, TNF-alpha (P < 0.01), PDGF-B (P < 0.01), TGF-beta (P < 0.001) and basic FGF (P < 0.01) in diabetic rats. However, FR139317 did not affect these mRNA levels in glomeruli of control rats. These findings suggest that FR139317 may be useful in the treatment of diabetic glomerulopathy by reducing mRNA levels of ECM components and growth factors.

Aging↗
PubMed1995

Primary peripheral-postthymic T-cell lymphoma in the central nervous system: immunological and molecular approaches to diagnosis.

Primary intracranial T-cell lymphoma is a very rare clinical entity, and only limited biological studies of this disease have been undertaken. A tumor specimen from a patient with a primary leptomeningeal and perivascular presentation of a T-cell lymphoma was analyzed using cellular and molecular techniques. Frozen sections of the sample were examined by immunohistochemical techniques using monoclonal antibodies to phenotypic marker antigens expressed on human lymphoid cells. Intercellular adhesion molecules expressed on the tumor were studied, as was expression of messenger ribonucleic acid (mRNA) transcripts of the T-cell receptor variable alpha and beta chain genes. The immunophenotypical analysis of lymphoma revealed that the tumor expressed CD2, CD3, CD4, CD5, CD25 and HLA-DR. In addition, all of the adhesion molecules studied (ICAM-1, LFA-3, VLA-1, CD11a, CD11b, and CD11c) were detected on the cell surface. Polymerase chain reaction amplification of mRNA from the tumor demonstrated 10 V alpha and three V beta T-cell receptor subfamilies, indicating that this tumor was a low-grade well-differentiated helper type of peripheral T-cell lymphoma of the central nervous system. In addition, the tumor was derived from multiple T-cell lineages.

Adult↗