Biomedical subjects

M Fukui

Publications and source records attributed to M Fukui.

At least 397 records · Page 22Linked to original sources

PubMed1994

[The usefulness of transcutaneous gas monitoring during hemorrhagic shock; discrepancy between the two transcutaneous gas tensions of anterior thorax and femur].

We measured transcutaneous gas tensions of both anterior thorax and femur. The differences between the two transcutaneous gas tensions were compared, as well as the relationship between the two transcutaneous and mixed venous blood gas tensions, in 10 dogs during hemorrhagic shock. The changes in femoral transcutaneous gas tensions correlated better with the changes in mixed venous gas tensions. The correlation between the two transcutaneous gas tensions were fairly good (oxygen tensions; r = .827, carbon dioxide tensions; r = .867). However, the discrepancy between the two gas tensions became greater in severe shock. Hence, oxygen tensions became smaller and carbon dioxide tensions became greater on femur than on anterior thorax. This indicates the possibility of "maldistribution of blood flow", which has already been detected between vital organs and skin, also exists between peripheral and central skin. Therefore, transcutaneous gas tensions should be monitored at peripheral skin, where gas tensions show greater changes and reflect systemic perfusion precisely than at central skin, during shock.

Animals↗

PubMed1994

[Pre and post operative evaluation of the perfusion reserve by acetazolamide 99mTc-HMPAO SPECT in patients with chronic occlusive cerebral arteries: a comparative study with PET].

We studied the pre and post-operative perfusion reserve using Diamox 99mTc-HMPAO SPECT in 7 patients with chronic occlusive cerebral arteries and then compared the results with PET. STA-MCA anastomosis was performed on 5 patients, while a carotid endarterectomy was done on 2 patients. The cerebral blood flow, the vascular response to CO2 or Diamox, the oxygen extraction fraction and transit time (CBV/CBF) were measured by PET. In the pre-operative state, the visual evaluations for hypoperfusion area at rest were agreed in 5 out of 7 patients in HMPAO SPECT and PET studies. In the remaining 2 patients, hypoperfusion areas were only detected in the PET study. The pre-operative evaluation of perfusion reserve was agreed in 2 patients. In the remaining 5 patients, 3 patients showed definite positive(++) in PET and positive(+) in HMPAO SPECT, and one patient showed positive (+) in PET and negative (-) in HMPAO SPECT. The post-operative change of hypoperfusion areas was well agreed in HMPAO SPECT and PET studies. However, the change of perfusion reserve was underestimated in HMPAO SPECT compared with PET. In the semiquantitative and quantitative analyses, the count rate ratios (affected/unaffected side) in HMPAO SPECT were apparently higher than those of CBF in PET. The postoperative change of the count rate ratios in HMPAO SPECT were smaller than those of CBF in PET. There was no significant correlation between the change in the ratio of the HMPAO SPECT after the administration of Diamox and the oxygen extraction fraction, and it was thus thought to be impossible to predict the areas with an increased oxygen extraction fraction. Thus, Diamox HMPAO SPECT may underestimate the areas of hypoperfusion or decrease in perfusion reserve when compared with PET. We should consider these limitations in the evaluation of pre and post operative cerebral hemodynamics.

Acetazolamide↗

PubMed1994

[Unusual manifestation of cerebral cysticercosis].

We have surgically treated two patients with cerebral cysticercosis, which were pre-operatively unexpected due to unusual CT and MRI manifestations. A 24 year old chinese farmer with intermittent severe headache for 6 years was examined by CT and MRI. A huge cystic lesion with same density or intensities to CSF occupied retroclival posterior fossa to upper cervical spinal canal and displaced neural structures backwardly. By suboccipital craniectomy, watery clear cyst fluid of 44ml was aspirated and the shrunken cyst was pulled out with ease. It was unable to predict until an electron microscopic study, which revealed a larva with three layers of microvilli, vesicular tegmentum and infrategmental muscle bundles and vesicles. The findings were same to those of racemose cysticercus of human brain. Giant cysts of cysticercosis were infrequently present supratentorially, although infratentorial or basal cysticercosis were racemose and small. The present case may be the first case of a huge cyst of cysticercosis in posterior fossa. A 44 year old Japanese businessman with 15 years history of general convulsion underwent craniotomy due to a small, but growing cystic granulomatous mass in right inferior frontal gyrus. The CT scan examined at 3 years after his first general convulsion revealed a small round low density mass, 5mm in diameter, in right frontal lobe and its wall was weakly enhanced by contrast media. The follow-up CT scans and MRIs revealed that the enhancing cystic mass became thick and deformed, and perifocal edema came to evident and progressed stepwise by attacks of general convulsions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Effects of enalapril on endothelin-1 and growth factor gene expression in diabetic rat glomeruli.

We have previously reported that the mRNA levels of endothelin (ET-1), tumor necrosis factor-alpha), (TNF-alpha), platelet-derived growth factor (PDGF)-B chain, transforming growth factor (TGF-beta), and basic fibroblast growth factor (bFGF) all increased with age in diabetic rat glomeruli. We have now assessed the effect of the angiotensin-converting enzyme inhibitor enalapril on the expression of the ET-1, TNF-alpha, PDGF-B, TGF-beta, and bFGF genes in 24-week-old rat glomeruli after streptozotocin injection. Animals were divided into controls, enalapril-treated diabetic rats, and untreated diabetic rats. Treatment continued for 24 weeks. Enalapril reduced both creatinine clearance (p < 0.001) and urinary protein excretion (p < 0.01) in diabetic rats. Enalapril produced a nonsignificant 15 mm Hg reduction in blood pressure in diabetic rats. Enalapril also attenuated the increases in ET-1 mRNA levels observed in the glomeruli of diabetic rats (0.5-fold compared with untreated diabetic rats at 24 weeks [p < 0.01]) but had no effect on increased mRNA levels of TNF-alpha, PDGF-B, TGF-beta, and bFGF. These findings suggest that enalapril therapy may be effective in reducing ET-1 mRNA expression in the glomeruli of diabetic nephropathy.

Animals↗

PubMed1993

Endothelin-1 mRNA expression by peripheral blood monocytes in IgA nephropathy.

We investigated endothelin-1 mRNA expression in peripheral blood monocytes from 40 patients with IgA nephropathy, 40 with other glomerulonephritides and 10 with essential hypertension without renal diseases, and from 30 healthy age-matched controls. 95% of patients with IgA nephropathy had increased endothelin-1 mRNA expression in monocytes but little was detected from the other groups. Endothelin-1 mRNA was positively correlated with urinary protein excretion (95% CI 0.835-0.952) and histopathological findings (0.796-0.939). In 15 patients with IgA nephropathy endothelin-1 mRNA values and proteinuria decreased gradually after treatment. Endothelin-1 mRNA-expressing activated monocytes may be associated with the progression of IgA nephropathy.

Adolescent↗

PubMed1993

Role of disulfide linkages in tachyplesin-lipid interactions.

In order to elucidate the role of the two disulfide linkages of tachyplesin I (T-SS), a membrane-acting cyclic antimicrobial peptide from Tachypleus tridentatus, we synthesized the acyclic analog (T-Acm) with the four SH groups protected by acetamidomethyl groups and also investigated the interactions of these peptides with lipid bilayers. T-SS induced leakage of calcein from egg yolk L-alpha-phosphatidylglycerol large unilamellar vesicles (PG LUVs) at peptide concentrations 1 order of magnitude smaller than those at which leakage was induced by T-Acm, which coincides with the stronger antimicrobial activities of T-SS. The micellization of PG LUVs was also more efficient for the cyclic peptide. Fluorescence titration studies revealed that binding affinities of both peptides to the PG membranes were similar. Fourier transform infrared polarized attenuated total reflection spectroscopy and fluorescence quenching experiments demonstrated that T-SS and T-Acm both form amphiphilic antiparallel beta-sheet structures in the membranes. They are formed in such a way that the sheet planes lie parallel to the membrane surface with the sheet hydrophobic surfaces penetrating slightly into the hydrophobic region of the bilayers. Furthermore, the observation that the linear T-Acm, the weaker membrane permeabilizer, caused a far more serious membrane disruption suggests the possibility that the mechanisms of membrane permeabilization by the cyclic peptide are different from those by the linear peptide, the latter being the disruption of the lipid organization.

Amino Acid Sequence↗

PubMed1993

Immunohistochemical distribution of amyloid precursor protein during normal rat development.

This study focused on the immunohistochemical identification of the beta/A4 amyloid precursor protein (APP) in various developmental stages of both the rat central nervous system (CNS) and the peripheral nervous system (PNS). A comparative study with myelin basic protein (MBP) and synaptophysin (SYP) facilitated the understanding of neuronal maturation and synaptogenesis on both prenatal and postnatal development. Our immunohistochemical study revealed APP to be widely distributed through the nervous system while existing mainly in the cytoplasm, dendrites and axons of the neurons. However, immunoreactivity was also observed in either the ependymal cells or the choroid plexus epithelial cells. Our immunostaining was carried out by the hydrated autoclaving method and revealed the expression of APP at embryonic day 15 in the neuron of the mesencephalic nucleus of the trigeminal nerve and the anterior horn of the spinal cord, trigeminal and spinal ganglion, ependymal cells and the choroid plexus. We thus observed dramatic changes of APP expression in the cerebellum from the embryonic stage. The maturation of synaptogenesis in the cerebellar molecular layer was parallel to the extension of the dendrites of Purkinje cells, which revealed immunoreactivity for APP. These findings suggested that APP played an important role in neuronal maturation and synaptogenesis. Thus, APP is considered to be a useful marker for neuronal development.

Amyloid beta-Protein Precursor↗

PubMed1993

[Contrast-enhanced MR imaging using double doses of gadolinium-DTPA in evaluating brain and spinal diseases].

Forty-one lesions of intracranial and spinal diseases underwent magnetic resonance (MR) imaging at both standard-dose (0.1 mmol/kg) and double-dose (0.2 mmol/kg) levels of gadolinium (Gd)-DTPA in order to reassess the optimal dose of Gd-DTPA. Each patient received an initial injection of 0.1 mmol/kg and an additional dose of 0.1 mmol/kg 5 min later. In quantitative analysis of contrast enhancement ratios of the enhancing part of the lesion, choroid plexus, cavernous sinus and pituitary stalk were significantly (P < 0.01) increased in double-dose studies. For visual comparison, we defined delineation as the extent to which the lesion may be defined; detectability was defined as the ability to visualize the lesion. With respect to delineation, double-dose studies were superior to standard-dose studies in nine of 20 intraaxial tumor (four of eight malignant gliomas, three of eight benign gliomas and two of four metastatic brain tumors) and five of six cerebral infarcts. The detectability of the lesion was improved in four cases (one astrocytoma, two metastatic brain tumors and one cerebral infarct) in double-dose studies. It was concluded that contrast-enhanced MR imaging using double doses of Gd-DTPA may be useful in the detection and evaluation of the extent of intraaxial lesions enhanced by Gd-DTPA.

Brain Diseases↗

PubMed1993

Messenger RNA expression for growth factors in glomeruli from focal glomerular sclerosis.

Focal glomerular sclerosis was induced in rats by chronic injections of puromycin aminonucleoside (PAN) on Days 0, 27, 34, and 41 and by unilateral nephrectomy on Day 22. Rats were sacrificed on Days 0, 8, and 20 (acute phase) and on Days 48, 60, and 80 (sclerotic phase). The percentage of sclerosing glomeruli was 16.6% on Day 48 and increased significantly to 72.8% on Day 80. We examined glomerular mRNA levels for proliferating cell nuclear antigen (PCNA), platelet-derived growth factor (PDGF)-A and B chains, transforming growth factor (TGF)-beta, epidermal growth factor (EGF), insulin-like growth factor (IGF)-I, and basic fibroblast growth factor (bFGF) on Days 0, 8, 20, 48, 60, and 80. Although these growth factor mRNA levels showed little change in glomeruli until Day 20, all growth factor mRNA levels increased in glomeruli during the sclerotic phase of PAN nephrosis as glomerular sclerosis progressed. On Day 80, mRNA levels for PCNA, PDGF-A and B chains, TGF-beta, EGF, IGF-I, and bFGF increased 12-, 10-, 12-, 15-, 2-, 2-, and 8-fold, respectively, in the glomeruli of PAN-treated rats with marked glomerular sclerosis when compared with control rats. Unilateral nephrectomy without PAN administration did not cause glomerular sclerosis up to Day 80 and mRNA levels for PCNA, PDGF-A and -B chains, TGF-beta, EGF, IGF-I, and bFGF in this group were almost the same as those in the normal sham-operated group. These data suggest that changes in growth factor mRNA levels in glomeruli may contribute to the development of PAN-induced glomerular sclerosis.

Animals↗

PubMed1993

Small heat-shock protein is expressed in meningiomas and in granulofilamentous inclusion bodies.

FF cellular expression of estrogen receptor-related small heat-shock protein (HSP27) in meningiomas was investigated immunologically. A cytoplasmic distribution of HSP27 was demonstrated in surgical specimens of 22 of 26 cases with meningiomas and cultured meningioma cells derived from two individuals. By Western blotting, HSP27 was detected in every tissue homogenate of 17 cases studied. Thus, HSP27 appears to be constitutively expressed in most meningiomas. In anaplastic portions of one papillary meningioma, there were numerous granulofilamentous inclusion bodies [Goldman JE et al. (1980) Cancer 46:156-161]. The inclusion bodies were immunopositive for HSP27 despite the negativity of the tumor cytoplasms. Thus, HSP27 seems to participate in the formation of certain inclusion bodies in meningioma cells, like alpha B-crystallin which participates in the formation of Rosenthal fibers in astrocytes.

Adult↗

PubMed1993

Hypothalamic hamartoma: the role of surgery.

A hypothalamic hamartoma associated with true precocious puberty in a 7-month-old girl is hereby reported. Hormonal studies disclosed elevated serum levels of luteinizing hormone (LH) and follicle stimulating hormone, both of which responded well to LH-releasing hormone stimulation. Following a subtotal removal of the tumor, the clinical manifestations of precocious puberty as well as associated endocrinological abnormalities returned to normal. The role of surgery for this lesion, which appears to be safe when a planned microsurgical course is employed, is discussed.

Female↗

PubMed1993

Optico-hypothalamic glioma: an analysis of 16 cases.

We reviewed our experience of 16 patients with histologically proven optico-hypothalamic gliomas. They ranged in age from 0.3 to 15 years at the time of diagnosis. Fifteen tumors were located in the optic chiasm, optic nerve, optic tract and/or hypothalamus, while one tumor was confined to one optic nerve. All tumors were classified as low-grade astrocytomas, which were mainly composed of pilocytic astrocytes. No patient had associated neurofibromatosis. The initial treatment for tumors included surgery in 12, radiotherapy in 7, and chemotherapy in 4 patients. After treatment, visual function improved in 3 out of 14, and endocrine function improved in 1 out of 4 evaluable patients. The 5-year actuarial survival rate was 84.0%, and that at 10 years 71.1%. Our experience and the literature indicate that: (1) patients with disease limited to the optic nerve are adequately managed by resection alone; (2) chiasmal-hypothalamic gliomas behave variably, and progressive disease may occur late in the course of the illness; (3) gliomas that arise in patients under 2 years of age and involve the optic chiasm may act aggressively despite their histological benignity; (4) the beneficial effects of radiotherapy occur in about half of the patients; (5) although chemotherapy may be an effective adjuvant treatment modality, it is not an alternative to radiation therapy at present. Both surgery and irradiation therefore offer the best treatment now available for patients with progressive disease.

Adolescent↗

PubMed1993

Widespread distribution of tau in the astrocytic elements of glial tumors.

Recently tau immunoreactivity has been observed in astrocytes in Alzheimer's disease and other neurological diseases. We examined the immunohistochemical localization of tau in 110 human brain tumors. Tau was widely distributed in the glial neoplastic cells and the reactive astrocytes in tumor tissues. In human surgical specimens positive immunostaining for tau was frequently observed in astrocytic tumors, oligodendroglial tumors, and glioblastoma, as well as neuronal tumors. The astrocytic neoplastic cells in medulloblastoma and other poorly differentiated tumors were also stained. In contrast, no immunoreactivity was observed in meningiomas and schwannomas. The expression of tau in brain tumors was mainly restricted to those cells with astrocytic features rather than small immature cells. The expression of tau mRNA was also demonstrated in astrocytic tumors. In conjunction with the findings of tau-positive astrocytes in some degenerative disorders, astrocytes are considered to have a potential to express tau through neoplastic transformation and reactive processes.

Animals↗

PubMed1993

Germ cell tumor in the hypothalamo-neurohypophysial region: clinical features and treatment.

Twenty-one patients with germ cell tumors (17 germinomas and 4 teratomas) involving the hypothalamic-neurohypophysial (HN) region were reviewed retrospectively. Eleven patients were males and 10 females, and their ages ranged from 7 to 45 years (average 18.5 years). Diabetes insipidus was the initial and the most prominent symptom in most germinomas; in teratomas the most prominent symptom was visual disturbance. Fifteen patients with germinomas were treated by radiotherapy, and 4 with teratomas were treated by surgical resection alone. Two recent germinoma patients with extensive CSF dissemination were treated with systemic chemotherapy consisting of anticancer platinum drugs and etoposide, which resulted in a complete disappearance of the tumors. Patients with germinoma treated after the introduction of CT scanning had a greatly improved mortality rate, and their actual survival rate was 87.5% over 10 years. On the basis of this review, the authors consider that diagnosis at an early stage of the disease and chemotherapy, which can be an effective therapeutic alternative to radiation therapy, may improve not only the mortality rate but also the quality of life of patients with HN germ cell tumors.

Adolescent↗

PubMed1993

Intracranial adenoid cystic carcinoma mimicking meningioma: report of two cases.

Two cases of intracranial adenoid cystic carcinoma mimicking meningioma are reported. In one, MRI showed not only a homogeneously enhancing extra-axial tumour attached to the dura mater of the posterior cranial fossa, but also surrounding dural enhancement, the "dural tail sign". In the second, CT demonstrated a well-demarcated enhancing extra-axial tumour, indistinguishable from a sphenoid ridge meningioma extending into the orbit. The neuroradiological features of intracranial adenoid cystic carcinoma may thus closely resemble those of meningioma.

Aged↗

PubMed1993

Immunocytochemical detection of calcineurin and microtubule-associated protein 2 in central neurocytoma.

An immunohistochemical study was carried out on four cases of central neurocytoma, which had characteristic clinicopathological features including ultrastructural findings. Specific antibodies to calcineurin (CaN), microtubule-associated protein 2 (MAP2) and synaptophysin (SYP) were used. All tumor tissues examined showed specific immunoreactivity for CaN and MAP2. Immunolabelling of both molecules revealed that they were mainly localized in the perikarya and proximal processes of the tumor cells. SYP immunoreactivity was found in three of the four cases. SYP immunoreaction products were predominantly seen in the tumor cell processes, while the perikarya were weakly or moderately positive for SYP. The data suggest that CaN and MAP2, together with SYP, can be useful tools for identifying and characterizing of the central neurocytoma.

Calcineurin↗

PubMed1993

Widening of capillary neck and alteration of extracellular matrix ultrastructure in diabetic rat glomerulus as revealed by computer morphometry and improved tissue processing.

Morphological and morphometric studies of glomeruli were carried out in streptozotocin-induced diabetic rats using improved tissue processing and computerized morphometry. Increased mesangial matrix, occupying the enlarged diabetic mesangium, contained an abundance of dark granular material in addition to the microfibrils which were usually found in the control glomeruli. In the diabetic glomeruli, the lamina densa was thick and heterogeneous showing a dense layer both on its epithelial and endothelial aspects, and the lamina rara externa contained more fibrils than in control rats. Detailed estimation of the absolute values of the various compartments of the diabetic glomeruli by using perfusion-fixed materials and a computer-assisted digitizer revealed that the volume and surface area of the mesangium were increased more extensively than those of the capillary; the enlargement of the mesangial-capillary interface area was the most pronounced among the morphometric changes of the diabetic glomeruli; and that the moderate increase in capillary volume was associated with an increased radius. Our quantitative results showed that capillaries in the diabetic glomeruli had an extensively wider neck which may be the first sign of structural damage to the glomerular tuft.

Animals↗

PubMed1993

Repeat angiography and magnetic resonance imaging (MRI) of dissecting aneurysms of the intracranial vertebral artery. Report of four cases.

We here present 4 cases with dissecting aneurysm (DA) of the intracranial vertebral artery, who were followed up by repeat cerebral angiography and MRI. The patients consisted of 2 males and 2 females, and the mean age was 43 years. Two cases were associated with polyarteritis nodosa (PN) and hypertension, respectively. Three of the cases developed subarachnoid haemorrhage (SAH), while the other one suffered from lateral medullary syndrome. In cerebral angiography, "pearl and string" signs were revealed in all cases, while a "double lumen" indicating a true diagnostic sign of DA was demonstrated in only one case. Repeat angiography showed that a bleb formation with a bulging of the aneurysmal sac was seen in 2 cases, and an irregularity of the wall in one case. On the other hand in one case, the ectatic part shrank, while the stenotic part was restored. In magnetic resonance imaging (MRI), a hyperintensity mass on T 1-weighted image (T 1-WI) adjacent to flow void suggesting either an intramural haematoma or a linear shape hyperintensity on T 1-WI were demonstrated in 3 cases. In the follow up MRI done in 2 cases, a serial change in the intensity from iso-intensity to hyperintensity on T 1-WI was observed in one case suggesting intramural haemorrhage, while an enlargement of the ectasic flow void was seen in the other case. Three of 4 cases were operated on by trapping of the aneurysms. One, who had systemic vascular diseases due to PN, and repeat angiography showed a regression of the aneurysm, was conservatively treated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗