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Biomedical subjects

O Nakagawa

Publications and source records attributed to O Nakagawa.

At least 19 recordsLinked to original sources

Association of remnant lipoprotein levels with impairment of endothelium-dependent vasomotor function in human coronary arteries.

BACKGROUND: It remains undetermined whether triglyceride-rich lipoproteins are an independent risk factor for atherosclerosis. METHODS AND RESULTS: The correlation of responses of coronary arterial diameter (quantitative coronary angiography) and coronary blood flow (intracoronary flow wire technique) to intracoronary infusion of acetylcholine (10 and 50 microg/min) with coronary risk factors including remnant lipoprotein levels was statistically analyzed in 106 consecutive subjects with normal coronary angiograms. Remnant lipoproteins were isolated from fasting blood with an immunoaffinity mixed gel containing anti-apolipoprotein (apo) A-1 and anti-apoB-100 monoclonal antibodies. In multivariate stepwise regression analysis, remnant lipoprotein levels had the most significant correlation with abnormal epicardial coronary vasomotor responses to acetylcholine infusion, reflected by impaired dilation or constriction of the epicardial coronary arteries, and the levels also had an inverse and independent correlation with the coronary blood flow increase in response to acetylcholine. In a subgroup of 53 consecutive subjects, constrictor responses of epicardial coronary diameters to intracoronary infusion of NG-monomethyl-L-arginine (50 micromol/min for 4 minutes) at baseline, reflecting the presence of coronary nitric oxide bioactivity, had an inverse and independent correlation with remnant lipoprotein levels by use of multivariate analysis. CONCLUSIONS: Remnant lipoprotein levels were independently associated with abnormal endothelium-dependent vasomotor function in large and resistance coronary arteries in humans, indicating that remnant lipoproteins may impair endothelial vasomotor function in human coronary arteries. The decrease in coronary nitric oxide bioactivity may be responsible in part for the inhibitory effects of remnant lipoproteins.

Acetylcholine

Endothelin-1 and cardiotrophin-1 induce brain natriuretic peptide gene expression by distinct transcriptional mechanisms.

Cardiotrophin-1 (CT-1) a novel IL-6-related cytokine, induces distinct hypertrophic responses to endothelin-1 (ET-1) on cultured neonatal rat cardiac myocytes. We found that ET-1 and CT-1 show a distinct pattern of gene induction of natriuretic peptides. Elucidation of the transcriptional mechanisms of brain natriuretic peptide (BNP) gene induction by. ET-1 or CT-1 will provide better information for our understanding of the molecular mechanisms of cardiac hypertrophy. In this study, reporter constructs containing the human BNP 5' flanking sequence were transfected into neonatal rat cardiac myocytes and the cells were stimulated with ET-1 or CT-1. A total of 1813 bp of the human BNP 5' flanking sequence conferred an ET-1 inducibility on the reporter gene. However, it did not confer CT-1 inducibility. These results show that distinct mechanisms are involved in BNP gene induction by ET-1 or CT-1, and (in this study) that the CT-1 responsive element is not located in the region examined.

Animals

Interaction of myocytes and nonmyocytes is necessary for mechanical stretch to induce ANP/BNP production in cardiocyte culture.

In cardiac hypertrophy or ventricular remodeling, enlargement of myocytes and interstitial or perivascular fibrosis are observed simultaneously, which suggests an interaction between cardiac myocytes and fibroblasts. In this study we examined the mechanism of cyclic mechanical stretch-induced myocytic hypertrophy, focusing on the interaction between myocytes and cardiac nonmyocytes, mostly fibroblasts. Ventricular myocytes (MCs) and cardiac nonmyocytes (NMCs) were separately extracted from neonatal rat ventricles by the discontinuous Percoll gradient method and primary cultures of cardiac cells were prepared. When MCs were co-cultured with NMCs, the size of MCs and the ANP/BNP secretion were significantly increased. This hypertrophic change of MCs in the co-culture was significantly suppressed by BQ-123, an endothelin-A (ETA) receptor antagonist. Cyclic stretch did not induce hypertrophic responses in MC culture. However, it further increased ANP/BNP production in MC-NMC co-culture (2.2-fold and 2.1-fold increases vs. non-stretch group after 48-h incubation). This increase in ANP/BNP production in the co-culture was significantly suppressed by CV-11974, an angiotensin II (Ang II) type 1 receptor antagonist. This study raises the possibility that NMCs regulate cardiocyte hypertrophy via secretion of endothelin-1 and that Ang II is involved in the interaction between MCs and NMCs during the course of hypertrophic response of cardiocytes to mechanical stretch.

Angiotensin II

Polymorphism of the angiotensin I-converting enzyme gene in diabetic nephropathy in type II diabetic patients with proliferative retinopathy.

Recently, deletion (D)/insertion (I) polymorphism in the Angiotensin I-converting enzyme (ACE) gene has been suggested to be related to the development of diabetic nephropathy in type I diabetes mellitus. This hypothesis, however, remains controversial. Differences in clinical states between patients, especially in glycemic control or duration of diabetes, could be responsible for these contradictory results. In this study we examined the relationship between D/I polymorphism of the ACE gene and diabetic nephropathy in type II diabetic patients who had already developed proliferative retinopathy (n = 45), and were thought to have been in a hyperglycemic state for long enough to develop microangiopathy. The patients were divided into two subgroups: 24 with nephropathy (albumin excretion rate: AER > or = 20 micrograms/min) and 21 without (AER < 20 micrograms/min). There was no difference in the duration of diabetes, HbA1c levels or average blood pressure over the previous year between these subgroups and other clinical characteristics were comparable. Patients without nephropathy exhibited allele I more often than those with nephropathy (p = .025). AER was lowest in genotype II and highest in genotype DD patients but the difference was not statistically significant (p = .07). From these findings, it was concluded that genotype II for the ACE gene could be a marker for reduced risk of diabetic nephropathy.

Case-Control Studies

Significance of ventricular myocytes and nonmyocytes interaction during cardiocyte hypertrophy: evidence for endothelin-1 as a paracrine hypertrophic factor from cardiac nonmyocytes.

BACKGROUND: In cardiac hypertrophy, both excessive enlargement of cardiac myocytes and progressive interstitial fibrosis are well known to occur simultaneously. In the present study, to investigate the interaction between ventricular myocytes (MCs) and cardiac nonmyocytes (NMCs), mostly fibroblasts, during cardiocytes hypertrophy, we examined the change in cell size and gene expression of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in cultured MCs as markers for hypertrophy in the neonatal rat ventricular cardiac cell culture system. METHODS AND RESULTS: The size of cultured MCs significantly increased in the MC-NMC coculture. Concomitantly, secretions of ANP and BNP into culture media were significantly increased in the MC-NMC coculture compared with in the MC culture (with the possible contamination of NMC <1% of MC). Moreover, in the MC culture, enlargement of MC and an increase in ANP and BNP secretions were induced by treatment with conditioned media of the NMC culture. A considerable amount of endothelin (ET)-1 production was detected in the NMC-conditioned media. BQ-123, an ET-A receptor antagonist, and bosentan, a nonselective ET receptor antagonist, significantly blocked the hypertrophic response of MCs induced by treatment with NMC-conditioned media. Angiotensin II (Ang II) (10(-10) to 10(-6) mol/L) and transforming growth factor-beta1 (TGF-beta1) (10(-13) to 10(-9) mol/L), both of which are known to be cardiac hypertrophic factors, did not induce hypertrophy in MC culture, but both Ang II and TGF-beta1 increased the size of MCs and augmented ANP and BNP productions in the MC-NMC coculture. This hypertrophic activity of Ang II and TGF-beta1 was associated with the potentiation of ET-1 production in the MC-NMC coculture, and the effect of Ang II or TGF-beta1 on the secretions of ANP and BNP in the coculture was significantly suppressed by pretreatment with BQ-123. CONCLUSIONS: These results demonstrate that NMCs regulate MC hypertrophy at least partially via ET-1 secretion and that the interaction between MCs and NMCs plays a critical role during the process of Ang II- or TGF-beta1-induced cardiocyte hypertrophy.

Angiotensin II

Expression of prostacyclin receptor in human megakaryocytes.

Prostacyclin (prostaglandin I2, PGI2) is a potent vasodilator and inhibitor of platelet aggregation. Although it is well known that the specific receptor for prostacyclin (PGI2-R) is abundantly expressed on platelets, PGI2-R expression in megakaryocytes is poorly understood. In this study, we examined its expression in leukemic or normal megakaryocytes. PGI2-R mRNA was expressed in human leukemic cell lines of megakaryocytic nature as evaluated by Northern blot analysis. Phorbol 12-myristate 13-acetate (PMA), interleukin-1 (IL-1), IL-3, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), thrombopoietin (TPO), and tumor necrosis factor-alpha (TNF-alpha) enhanced PGI2-R mRNA expression. The enhancement of PGI2-R expression by PMA and TPO was associated with the upregulation of platelet factor 4 or glycoprotein IIb mRNA expression. Iloprost, an agonist of prostacyclin, induced significant cyclic (c)AMP synthesis in these leukemic cells indicating that interaction of PGI2-R and its ligand can induce postreceptor signal transduction. Furthermore, iloprost-induced cAMP synthesis was enhanced by the pretreatment with PMA or the cytokines that promoted PGI2-R expression. PMA and TPO also increased the specific binding of [3H]iloprost to these cells. Pooled normal megakaryocytic colonies from TPO-containing semisolid culture of purified human CD34+ cells expressed PGI2-R, which were increased as the megakaryocytes matured with the peak expression before proplatelet formation, as evaluated by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). These results indicate that PGI2-R is expressed in human megakaryocytes and is upregulated by cytokines involved in thrombopoiesis or inflammation. Also, it was indicated that megakaryocytic maturation accompanies enhancement of PGI2-R expression.

Cell Differentiation

Expression of natriuretic peptide system during embryonic stem cell vasculogenesis.

The natriuretic peptide family consists of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). We have elucidated that CNP is synthesized by endothelial cells. We have also shown that CNP secretion is potently suppressed by vascular endothelial growth factor (VEGF). In the present study, we examined the developmental gene expression of the natriuretic peptide system with the expression of VEGF and endothelial cell-specific receptor tyrosine kinases (RTKs), which expression is necessary for vasculogenesis, using embryoid bodies (EB) as an in vitro model for vascular development. When mouse embryonic stem (ES) cells were cultured in suspension culture, ES cells spontaneously differentiated into EB on day 4 and then into cystic EB (day 10). The VEGF gene transcript was detected early, on day 4. The expression of Flk-1, and flt-1 (the two VEGF receptors) and also of tie-2, which is crucial for blood island formation, was detected as early as day 4, and also on days 8 and 21. In contrast, the expression of flt-4, the receptor for VEGF-C, and tie-1, was first detected on day 21. Along with the developmental expression of these markers of differentiation for endothelial cells, the gene expression of CNP and its specific receptor, ANP-B receptor, was detected on days 4, 8, and 21. In contrast, the gene expression of BNP, which acts as a cardiac hormone, and the gene expression of the ANP-A receptor, which is specific to ANP and BNP, was first detected on days 8 and 21, respectively. These results indicate the distinct role of CNP in the natriuretic peptide family and the close linkage of CNP expression and endothelial cell differentiation, suggesting a possible role of CNP in vasculogenesis.

Animals

Role of cardiac nonmyocytes in cyclic mechanical stretch-induced myocyte hypertrophy.

In cardiac hypertrophy or ventricular remodeling, not only the enlargement of myocytes but also interstitial or perivascular fibrosis are observed simultaneously, which suggests an interaction between cardiac myocytes and fibroblasts. In this study, we examined the mechanism of cyclic mechanical stretch-induced myocyte hypertrophy, highlighting the interaction between myocytes and cardiac nonmyocytes, mostly fibroblasts. Ventricular myocytes (MC) and cardiac nonmyocytes (NMC) were separately extracted from neonatal rat ventricles by the discontinuous Percoll gradient method and primary cultures of cardiac cells were prepared. Cyclic mechanical stretch was applied to the cultures with a Flexercell Stress Unit. In addition to cell size, we examined atrial natriuretic peptide/brain natriuretic peptide (ANP/BNP) production as the most sensitive biological markers for MC hypertrophy. Cyclic stretch did not induce hypertrophic responses in MC when they were cultured without NMC. In contrast, when MC were co-cultured with NMC, cyclic stretch induced further increase in ANP/BNP production (2.2-fold and 2.1-fold increases versus non-stretch group, after 48-h incubation). This increase in ANP/BNP production in the co-culture was significantly suppressed by CV-11974, an angiotensin II type 1 receptor antagonist. Moreover, ANP/BNP production in the co-culture was significantly suppressed by BQ-123, an endothelin A receptor antagonist, whether cyclic stretch was applied or not. This study raised the possibility that NMC mediate the hypertrophic effect of mechanical stress on MC by increasing endothelin production. It was also suggested that, in this process, angiotensin II is involved in the crosstalk between MC and NMC.

Angiotensin Receptor Antagonists

ROCK-I and ROCK-II, two isoforms of Rho-associated coiled-coil forming protein serine/threonine kinase in mice.

We recently identified a novel human protein kinase, p160 ROCK, as a putative downstream target of the small GTPase Rho. Using the human ROCK cDNA as a probe, we isolated cDNA of two distinct, highly related sequences from mouse libraries. One encoded a mouse counterpart of human ROCK (ROCK-I), and the other encoded a novel ROCK-related kinase (ROCK-II). Like ROCK/ROCK-I, ROCK-II also bound to GTP-Rho selectively. ROCK-I mRNA was ubiquitously expressed except in the brain and muscle, whereas ROCK-II mRNA was expressed abundantly in the brain, muscle, heart, lung and placenta. These results suggest that at least two ROCK isoforms are present in a single species and play distinct roles in Rho-mediated signalling pathways.

Amino Acid Sequence

Stimulation by corticotropin-releasing factor of atrial natriuretic peptide and brain natriuretic peptide secretions from cultured neonatal rat cardiomyocytes.

The new functional role of corticotropin-releasing factor (CRF) in the regulation of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) release was investigated using cultured neonatal rat cardiomyocytes. Treatment with CRF (10(-10)-10(-6) M) resulted in dose- and time-dependent increase in ANP and BNP secretion, up to 2.5-fold and 1.8-fold above control values, respectively. The effect was significant at 6 hr and persisted for at least 36 hr. The effect of CRF (10(-7) M) was partially blocked by alpha-helical CRF(9-41) (10(-7) M), a specific CRF receptor antagonist. The effect of CRF (10(-7) M) was not only blunted by cAMP-dependent protein kinase A (PKA) inhibitor, H-89 (10(-5) M), but also by protein kinase C inhibitors, H-7 (50 microM) and Calphostin C (10(-6) M). H-7 (50 microM) and Calphostin C (10(-6) M) alone lowered basal ANP and BNP levels. Furthermore, CRF (10(-7) M) stimulates protein synthesis up to 1.2-fold. These results indicate that CRF stimulates ANP and BNP secretions through the CRF receptor and, at least in part, via PKA activation during cardiac hypertrophy.

8-Bromo Cyclic Adenosine Monophosphate

cDNA cloning of rat cardiotrophin-1 (CT-1): augmented expression of CT-1 gene in ventricle of genetically hypertensive rats.

Cardiotrophin-1 (CT-1) is a novel cytokine that was discovered from mouse embryoid bodies by means of expression cloning. It induces hypertrophy in cultured myocytes by activating a gp130 signaling pathway. To investigate the expression of the CT-1 gene in both normal adult and genetically hypertensive rats, we cloned rat CT-1 cDNA. The amino acid sequence is 94% identical to that of mouse CT-1. A significant amount of CT-1 mRNA was expressed in the ventricle of adult rats and also detected in the lung, kidney, liver, skeletal muscle, stomach and urinary bladder. Northern blot analysis revealed that the CT-1 mRNA level is significantly augmented in the ventricle of 12-week-old spontaneously hypertensive rats-stroke prone/Izm at a stage of established hypertension, suggesting a possible relevance of CT-1 to ventricular hypertrophy.

Amino Acid Sequence

Gene expression of the human prostaglandin E receptor EP4 subtype: differential regulation in monocytoid and lymphoid lineage cells by phorbol ester.

We isolated a cDNA clone encoding the human prostaglandin (PG) E receptor EP4 subtype and examined the gene expression in human blood cells. Northern blot analysis revealed that the EP4 gene is expressed at a high level in peripheral blood mononuclear cells, and at lower levels in cultured human blood cell lines, THP-1 and U937 (monocytoid cell lines), MOLT-4 and Jurkat (T-cell lines), and Raji (B-cell line). To examine regulation of the EP4 gene expression in the immune system, we studied the effects of phorbol 12-myristate 13-acetate (PMA) on these cell lines. Gene expression was upregulated in THP-1, U937, and Raji cells by PMA, and was downregulated in MOLT-4 and Jurkat cells. In THP-1 cells the effects of PMA were further analyzed, and the upregulation of the EP4 gene was shown to be followed by an increase in PGE2 binding sites and in PGE2-induced cAMP accumulation. In the striking contrast, other PGE receptor subtypes (EP1, EP2 and EP3) and other prostanoid receptors (IP and DP) were shown not to be upregulated by PMA. Therefore, this is the first demonstration of a highly specific upregulation of the EP4 subtype in THP-1 cells treated with PMA, suggesting the importance of the EP4 subtype in the immune system. In the present study we also clarified that EP4 gene expression is regulated differently among human monocytoid and lymphoid lineage cells, thus leading to the better understanding of the regulatory mechanisms for the human EP4 gene expression in the immune system.

Burkitt Lymphoma

Regulation of secretion and clearance of C-type natriuretic peptide in the interaction of vascular endothelial cells and smooth muscle cells.

OBJECTIVE: To clarify the significance of C-type natriuretic peptide in the interaction between endothelial cells and vascular smooth muscle cells by investigating the endothelial production of C-type natriuretic peptide and the clearance mechanism of C-type natriuretic peptide using the endothelial cells-smooth muscle cells co-culture system. RESULTS: Secretion of C-type natriuretic peptide in the direct co-culture of endothelial cells with smooth muscle cells elicited as much as a 60-fold increase compared with endothelial cells alone. The accumulation of intracellular cyclic GMP in the co-culture was consequently increased and the elevation of cyclic GMP level in the co-culture was abolished by the anti-C-type natriuretic peptide monoclonal antibody. The elevated cyclic GMP production in the co-culture was abolished by the anti-transforming growth factor-beta neutralizing antibody. Candoxatrilat (10(-6)-10(-4) mol/l), a neutral endopeptidase inhibitor, dose-dependently increased the concentrations of C-type natriuretic peptide in the culture medium with endothelial cells alone, but not in the endothelial cells-smooth muscle cells co-culture. The transcript of neutral endopeptidase messenger RNA was detected in endothelial cells but not in smooth muscle cells by reverse transcriptase polymerase chain reaction. Treatment with C-atrial natriuretic factor4-23 (10(-9)-10(-6) mol/l), the specific ligand for the clearance receptor of the natriuretic peptides, resulted in dose-dependent augmentation of C-type natriuretic peptide concentration and concomitant intracellular cyclic GMP production in the endothelial cells-smooth muscle cells co-culture but not in endothelial cells alone. CONCLUSION: The present study demonstrated that direct interaction between endothelial cells and smooth muscle cells augments C-type natriuretic peptide secretion from endothelial cells through transforming growth factor-beta activation, and revealed that the enzymatic degradation is responsible for the steady state level of C-type natriuretic peptide in endothelial cells alone and that the receptor-mediated clearance mainly determines the augmented level of C-type natriuretic peptide in the interaction between endothelial cells and smooth muscle cells. The results taken together raise the possibility that endothelial C-type natriuretic peptide might play a role in regulation of vascular tone and remodelling.

Animals

cDNA cloning and gene expression of human type Ialpha cGMP-dependent protein kinase.

The type I cGMP-dependent protein kinase (cGK) is one of the major pathways for the cGMP cascade and has been demonstrated to inhibit platelet aggregation, relax smooth muscle cells, and control cardiocyte contractility. There are two subtypes of the type I cGK, cGKIalpha and cGKIbeta. The former is more sensitive to cGMP than the latter. In humans, cGKIbeta cDNA was isolated, but the full structure and tissue-specific gene expression of cGKIalpha have not been determined. The significance of cGK in human cardiovascular diseases has not been investigated at the molecular level. In the present study, we isolated the full-length human CGKIalpha cDNA (-36 to +2177; the translation start site: +1) enclosing the 671-amino acid protein. Nucleotides +267 to +2177 of the isolated cDNA were identical to the corresponding nucleotides of human cGKIbeta cDNA. Southern blot analysis suggested that human cGKIalpha and cGKIbeta are generated by alternative splicing of a single gene assigned to chromosome 10. By Northern blot analysis, we detected abundant human cGKIalpha mRNA (7.0 kb) in the aorta, heart, kidneys, and adrenals. In contrast, human cGKIbeta mRNA (7.0 kb) was detected abundantly only in the uterus. In cultured vascular smooth muscle cells, the type I cGK mRNA concentration was reduced to 10% of the basal level by 4 x 10(-10) mol/L platelet-derived growth factor. Angiotensin II (10(-8) mol/L), transforming growth factor-beta (4 x 10(-11) mol/L), and tumor necrosis factor-alpha (6 x 10(-6) mol/L) also exhibited an inhibitory effect on type I cGK gene expression. These findings suggest a pathophysiological implication of the type I cGK in cardiovascular diseases, including hypertension and atherosclerosis.

Amino Acid Sequence

Regulation of very-low-density lipoprotein receptor in hypertrophic rat heart.

To elucidate the regulation of very-low density-lipoprotein (VLDL) receptor, we have studied its gene expression in the heart of spontaneously hypertensive rats-stroke prone (SHR-SP, an animal model for hypertension-induced cardiac hypertrophy) compared with Wistar-Kyoto rats. RNase protection assay showed that ventricular VLDL receptor mRNA falls to 41% of normal levels at 4 weeks when hypertension is not yet fully developed, and drops further to 14% at 13 weeks, when cardiac hypertrophy is established. Lipoprotein lipase mRNA decreases in parallel with VLDL receptor mRNA. In cultured neonatal rat ventricular cardiomyocytes, VLDL receptor mRNA decreases in parallel with the process of cardiocyte hypertrophy during the 24 hours after treatment with 10-8 mol/L endothelin-1, falling to 40% of the initial value. These results demonstrate that there is downregulation of VLDL receptor gene expression in cardiac hypertrophy both in vivo and in vitro and suggest that the regulation of the VLDL receptor is possibly linked with the switch in energy substrate from lipid to glucose known to occur in cardiac hypertrophy.

Animals

Regulation of endothelial production of C-type natriuretic peptide in coculture with vascular smooth muscle cells. Role of the vascular natriuretic peptide system in vascular growth inhibition.

Recently, we have demonstrated that C-type natriuretic peptide (CNP) is produced in vascular endothelial cells (ECs). In the present study, we investigated the interaction of ECs and vascular smooth muscle cells (SMCs) for endothelial production of CNP and its action on vascular growth, using the EC/SMC coculture system. The concentration of CNP-like immunoreactivity in the medium was increased 60-fold within 48 hours in the EC/SMC coculture with direct contact compared with that in EC alone. Northern blot analysis revealed the augmented expression of CNP mRNA in the EC/SMC coculture. The accumulation of intracellular cGMP in the coculture was concomitantly increased, and this response was blocked by anti-CNP monoclonal antibody and HS-142-1, a nonpeptide atrial natriuretic peptide receptor antagonist. The concentration of biologically active transforming growth factor-beta (TGF-beta) in the culture medium of the coculture with direct contact of ECs and SMCs was elevated to the level to stimulate endothelial production of CNP. Actually, the neutralizing antibody against TGF-beta abrogated the cGMP accumulation in the coculture. These results show that endothelial production of CNP in the EC/SMC coculture is at least in part regulated by TGF-beta. Furthermore, the conditioned medium from ECs stimulated by TGF-beta was demonstrated to have a growth-inhibitory effect on SMCs, which was abolished by anti-CNP monoclonal antibody and HS-142-1. The treatment with anti-CNP monoclonal antibody and HS-142-1 also significantly increased the cell number of the EC/SMC coculture. The present study reveals the pathophysiological significance of endothelial CNP as a paracrine/autocrine vascular regulator for vascular growth in the interaction of ECs and SMCs.

Animals

[The cases of acute spontaneous subdural hematoma].

In this paper, 10 cases of acute spontaneous subdural hematoma (ASSDH) among 149 cases of all acute subdural hematoma (ASDH) were reported with a review of 36 cases in the literature. The age of the patients with ASSDH ranged from 48 to 90 years (mean age of 71.9 years), and the average age of ASDH patients was 52.4 years. The male to female ratio of ASSDH and ASDH was 3:7 and 5:2, respectively. ASSDH patients were older than ASDH patients, and ASSDH patient tended to be female. Four cases of ASSDH patients had the past history of dementia. The outcome of 5 cases of ASSDH with general complications was fatal. During operation in all cases except one, spurting arterial rupture from a branch of the cortical artery adjacent to the Sylvian fissure was observed. It was presumed in the literature that the mechanism of the arterial rupture is gliding movement of the brain, tearing an arterial twig with dural attachment, or the existence of the junction of an arterial twig as an anatomically weak point. Hypertension, alcoholism, dementia, past history of subdural hematoma or subarachnoid hemorrhage may be important influencing factors in this mechanism.

Acute Disease