Biomedical subjects

H Abe

Publications and source records attributed to H Abe.

At least 433 records · Page 24Linked to original sources

PubMed1997

Induction of cytokines, chemokines and adhesion molecule mRNA in a rat forebrain reperfusion model.

Cellular damage secondary to reperfusion following ischemic insult has been hypothetically attributed to an inflammatory cascade concerted by cell-to-cell interactions. While the role of several cytokines and adhesion molecules in reperfusion injury of the brain has been explored to a certain extent, their regulatory and temporary profiles remain unclear. We have addressed the temporal features of the induction of mRNA for proinflammatory cytokines, adhesion molecules and chemokines at an acute phase subsequent to reperfusion in rat forebrain. Semiquantitatively calibrated reverse transcription-polymerase chain reaction analysis was employed to assess the relative expression of mRNA for intercellular adhesion molecule (ICAM)-1, interleukin (IL)-1 alpha, IL-1 beta, 1L-2, 1L-6, tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, monocyte-chemoattractant protein (MCP)-1, and macrophage migration inhibitory factor (MIF). The increase in mRNA from the basal levels after reperfusion followed one of two different patterns; an increase occurring as early as 1 h, or a slight increase continuing up to 24 h after reperfusion. The former pattern was seen for ICAM-1, IL-1 alpha, IL-1 beta, TNF-alpha, and MCP-1, and the latter for IL-6 and MIF. These results were consistent with the proinflammatory properties of the immediately induced cytokines, which may be involved in the initiation step of the inflammatory cascade, causing the secondary cellular responses and finally leading to further brain damage.

Animals↗

PubMed1997

Surgical removal of a cavernous sinus chondroma.

BACKGROUND: Chondromas at the base of the skull are most commonly found in the parasellar and sellar regions, and present varying degrees of involvement of the cavernous sinus. However, those confined mainly to the cavernous sinus are rare, and only a few reports show detailed radiological and surgical findings. MATERIALS AND METHODS: This 40-year-old woman experienced sudden right orbital pain followed by right third and sixth cranial nerve palsies. Computerized tomography scan and magnetic resonance image depicted a well-circumscribed mass in the right cavernous sinus. A frontotemporal craniotomy with orbito-zygomatic osteotomy was used to approach this lesion intradurally. We drilled away the anterior clinoid process using a high-speed air drill extradurally, exposed the intrapetrous carotid artery, and dissected the right sylvian fissure from the distal, fully exposing the surface of the right cavernous sinus. The soft and grayish tumor was easily removed using sucker and tumor forceps; the venous bleeding from the sinus itself was easily controlled. RESULTS: The tumor was successfully removed via a superior triangle. Intradural invasion of the tumor and heavy venous bleeding from the sinus were not observed. Histologically, the mass was diagnosed as a mature chondroma. The tumor was presumed to originate from the right posterior clinoid process. The lesion was totally removed, and postoperative right ophthalmoplegia had fully disappeared within 6 months after surgery. CONCLUSION: Successful surgical attack of lesions in the cavernous sinus requires comprehensive and precise knowledge of the microsurgical anatomy and neuroradiology.

Adult↗

PubMed1997

Vasoreconstructive surgery for radiation-induced vasculopathy in childhood.

BACKGROUND: Cerebral vasculopathy associated with the appearance of netlike vessels can develop following irradiation therapy for parasellar brain tumors, especially in children. However, little is known regarding the clinical course of this disease or the appropriate therapy for it. CASE REPORTS: We experienced two surgically-treated patients with radiation-induced vasculopathy and reviewed the previously reported cases. Both of our patients were treated with encephalo-duro-arterio-myo-synangiosis combined with superficial temporal artery to middle cerebral artery (STA-MCA) bypass. Their ischemic symptoms improved following the surgery, associated with a good angiographic neovascularization from the STA-MCA bypass, as well as dural and muscular arteries. CONCLUSION: Our findings and the review of the previous reports suggested that surgical therapy may be beneficial for the patients with radiation-induced vasculopathy with the appearance of netlike vessels.

Brain Ischemia↗

PubMed1997

Resection of a recurrent parasagittal meningioma with cortical vein anastomosis: technical note.

BACKGROUND: Simpson Grade I resection of parasagittal meningiomas is not always feasible because of the involvement of the sagittal sinus and cortical veins. Complete resection requires reconstruction of the sagittal sinus and cortical veins. This report describes a surgical technique to preserve patency of the cortical veins. CASE REPORT: A recurrent parasagittal meningioma completely occupied the superior sagittal sinus and encased several large cortical veins. The tumor in the sagittal sinus was totally resected and the roof of the sinus was sutured. To avoid thrombotic cortical vein occlusion, two cortical veins encased by the meningioma were anastomosed end-to-end, regardless of their flow directions. The postsurgical course was uneventful and patency of the anastomosed veins was confirmed by postoperative angiography. CONCLUSIONS: End-to-end anastomosis of cortical veins was a useful surgical technique for radical resection of a parasagittal meningioma.

Adult↗

PubMed1997

Low cerebral blood flow and perfusion reserve induce hyperperfusion after surgical revascularization: case reports and analysis of cerebral hemodynamics.

BACKGROUND: Hyperperfusion syndrome after surgical revascularization is a rare complication and there has not been any systematic study on factors that induce hyperperfusion after surgery. In this paper, we retrospectively analyzed the factors related to this syndrome. PATIENTS AND METHODS: We performed 46 cases of surgical revascularization including 33 cases of carotid endarterectomy (CEA) and 13 cases of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis during the past 5 years. Among these, we encountered three cases of hyperperfusion syndrome despite well-controlled blood pressure postoperatively. To evaluate factors related to the occurrence of hyperperfusion syndrome, we examined four parameters: (1) regional cerebral blood flow (rCBF), (2) the increase in the ratio of the postoperative rCBF compared to the preoperative rCBF (increase ratio), (3) cerebral perfusion reserve presented by the increase of rCBF after acetazolamide administration (delta rCBF), and (4) the difference in mean blood pressure between the preoperative and postoperative state (delta BP). RESULTS: Preoperative rCBF was significantly lower in cases of hyperperfusion syndrome than the control cases (p < 0.01 Mann-Whitney U-test). Moreover delta rCBF was evidently lower in the hyperperfusion cases than the control (p < 0.05 Fisher's exact method). However, there was no significant difference in the delta BP between the hyperperfusion cases and the control cases. CONCLUSION: In cases of marked low perfusion (low rCBF) with poor perfusion reserve (low delta rCBF), hyperperfusion after surgical revascularization can occur even if blood pressure is adequately controlled.

Aged↗

PubMed1997

Changes of behavior and monoamine metabolites in the rat brain after repeated methamphetamine administration: effects of duration of repeated administration.

1. The authors studied the mechanism of the reverse-tolerance phenomenon caused by long-term administration of central stimulant drugs. Methamphetamine(MAP) was chronically administered to rats, and the reverse-tolerance phenomenon was studied in terms of behavioral changes and changes in monoamine metabolites, the latter being examined by in vivo microdialysis of the extracellular compartment of the corpus-striatum. The authors also studied [3H]SCH23390 and [3H]spiperone binding to striatal membranes after chronic MAP administration. 2. MAP(4 mg/kg) or saline was administered intraperitoneally once daily to male rats. In Groups 1 and 2, 10 and 30 injections of MAP were given, respectively. In Groups 3 and 4, animals received 10 and 30 injections of saline as controls. One week after the final injection, all rats were challenged with 4 mg/kg MAP. 3. Groups 1 and 2 displayed more intense stereotypy than Groups 3 and 4, indicating that behavioral sensitization had been achieved in the former. Dopamine(DA) levels increased rapidly in response to MAP challenge in all groups, with the increases in Groups 1 and 2 being more marked than that in Groups 3 and 4. Group 1 showed greater persistence and a higher rate of DA increase than Group 2. 4. The number of D1 and D2 dopamine receptors did not change after the repeated MAP administration. 5. The rate of increase in DA release induced by MAP was dependent on the duration of repeated administration, and there was no correlation between the intensity of stereotypy and the rate of increase in DA release induced by MAP. These findings suggest that enhancement in DA release is unlikely to be the sole cause of behavioral sensitization.

Animals↗

PubMed1997

Evaluation of cytokines in cerebrospinal fluid from patients with moyamoya disease.

We investigated the levels of angiogenic growth factors in cerebrospinal fluid (CSF) from patients with Moyamoya disease and from those with atherosclerotic occlusive disease to evaluate the relationship of these factors to the pathogenesis of Moyamoya disease. CSF from Moyamoya patients contained significantly higher concentrations of basic fibroblast growth factor (b-FGF) (P < 0.05). The b-FGF level was apparently elevated in patients with well developed neovascularization after indirect revascularization surgery (P < 0.01). The other angiogenic factors were not significantly elevated compared with those of the control group.

Adult↗

PubMed1997

Familial occurrence of moyamoya disease.

There is extensive evidence that Moyamoya disease has a tendency for multifactorial inheritance, although the pathogenesis of Moyamoya disease is not clear. The authors report five cases showing familial occurrence of Moyamoya disease and analyse its clinical characteristics. In the past 15 years, we have encountered 68 cases of Moyamoya disease. Among these, 14 cases (10 females and four males, five family pedigrees, asymptomatic 1 case) of familial occurrence were observed. In this series, mother-to-child inheritance was observed in five cases, although there were no cases showing father-to-child inheritance. Ten patients were children with an initial onset of cerebral ischemia, at a mean age of 9.7 years. One mother was asymptomatic and two mothers had a past history of cerebral ischemia. Only one patient was a 37-year-old woman with clinical onset of intracerebral hemorrhage. There were no specific clinical characteristics in familial Moyamoya disease compared with those in sporadic Moyamoya disease.

Adult↗

PubMed1997

Direct and indirect revascularization for moyamoya disease surgical techniques and peri-operative complications.

We have performed surgical treatment for Moyamoya disease using the superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and encephalo-duro-arterio-myo-synangiosis (EDAMS). In this paper, the surgical technique of combined revascularization for Moyamoya disease as well as peri-operative complications are discussed. Craniotomy and dural opening were extensively carried out to expose the brain surface as widely as possible. Dissection of the STA, which is the most powerful resource of direct revascularization, should be carefully carried out using a surgical microscope. The temporal muscle and middle meningeal artery, which have the most potential as sources of indirect revascularization, must be preserved. STA-MCA anastomosis to the frontal branch of the middle cerebral artery is indispensable for improving cerebral circulation of the frontal lobe. A small arachnoid membrane opening and water-tight closure are also important to avoid post-operative subdural and subcutaneous fluid collection. Ischemic events disappeared immediately after surgery in most cases. However, in several cases, transient ischemic attacks recurred for several months after the surgery. Chronic subdural hematoma was seen in two cases.

Adolescent↗

PubMed1997

Adrenocorticotrophin-independent macronodular adrenal hyperplasia in a patient with lysine vasopressin responsiveness but insensitivity to gastric inhibitory polypeptide.

The aetiology of ACTH-independent macronodular adrenal hyperplasia (AIMAH) is uncertain. We examined a 55 year old man with Cushing's syndrome due to AIMAH, whose cortisol levels increased after stimulation with lysine-8-vasopressin (LVP) in vitro as well as in vivo. Abdominal MRI revealed nodular enlargement of both adrenal glands. No adenoma was evident on pituitary MRI. 131I-adosterol scintigraphy exhibited marked uptake into both adrenal glands. Although baseline plasma cortisol levels were within normal limits, urinary free cortisol excretion was 3-fold higher than the upper limit of the normal range. Plasma ACTH levels were undetectable. Oral dexamethasone failed to suppress plasma cortisol levels irrespective of dose, and administration of corticotrophin releasing hormone failed to increase plasma ACTH and cortisol levels. LVP injection failed to increase plasma ACTH levels, but elicited an increase in plasma cortisol levels. The direct stimulatory effect of LVP on cortisol secretion was confirmed in vitro in cultured adrenocortical cells from macronodules obtained at surgery. Food intake, gastric inhibitory polypeptide (GIP), or octreotide administration, which were reported to regulate cortisol release in patients with AIMAH, failed to affect plasma cortisol levels. In conclusion, plasma cortisol responsiveness to LVP, GIP, and octreotide is heterogeneous in patients with AIMAH.

Adrenal Glands↗

PubMed1997

Metastatic cancer involving pancreatic duct epithelium and its mimicry of primary pancreatic cancer.

We investigated 47 autopsy cases of metastatic cancer involving the pancreas. Metastatic disease in nine cases involved the pancreatic duct epithelium. In two cases, metastatic cancer cells showed Pagetoid features. In three cases, pancreatic metastatic disease showed solitary proliferation with focal in situ carcinoma-like lesions mimicking primary pancreatic cancers. Each of these three cases had primary lung adenocarcinomas. Serial sections revealed abrupt borders between the in situ carcinoma-like lesions and the non-cancerous epithelium. Primary pancreatic cancers did not show Pagetoid features or abrupt borders between the cancerous and non-cancerous epithelium. We conclude that the possible diagnosis of pancreatic metastasis should be carefully ruled out in the histological detection of latent primary pancreatic cancer.

Aged↗

PubMed1997

Comparison of Tc-99m pertechnetate with Tl-201 and Ga-67 scintigraphy of malignant soft-tissue tumors.

Tc-99m pertechnetate scintigraphy was compared with Tl-201 chloride and Ga-67 citrate to evaluate the avidity of Tc-99m pertechtate for malignant soft-tissue tumors. Twenty-three patients with malignant soft-tissue tumors underwent scintigraphic studies. All 23 received Tc-99m and Tl-201, whereas 14 also were injected with Ga-67. In 21 (91%) of the 23 patients, Tc-99m accumulated extensively in the tumors. Tl-201 accumulated in 12 (52%) of the 23 tumors. Ga-67 accumulated in only 5 (36%) of the 14 tumors. The avidity of Tc-99m for myxoid tumors was markedly different from the other two agents. Tc-99m accumulated in all eight myxoid tumors, while neither Tl-201 or Ga-67 showed marked accumulation except for one patient with increased accumulation of Tl-201. This study shows that Tc-99m pertechnetate has the potential to localize malignant soft-tissue tumors and may be useful in the evaluation of these tumors.

Extremities↗

PubMed1997

Homozygous p53 gene mutation in a radiation-induced glioblastoma 10 years after treatment for an intracranial germ cell tumor: case report.

OBJECTIVE: Radiation-induced glioma is a rare but serious complication of radiotherapy. Underlying radiation-induced mutations in oncogenes or tumor suppressor genes have not previously been described. CLINICAL PRESENTATION: A 16-year-old female patient developed a glioblastoma in the right frontal lobe 10 years after treatment of a suprasellar germ cell tumor with 50 Gy ionizing radiation. The glioblastoma was undetectable on a high-resolution magnetic resonance image obtained 3 months before diagnosis. METHODS AND RESULTS: A p53 functional assay was used to examine the transcriptional competence of the p53 tumor suppressor gene. This assay scores the content of mutant p53 alleles in tumor and blood samples quantitatively as a percentage of red yeast colonies. The glioblastoma contained 95% mutant p53 alleles, whereas blood from the patient and her parents contained only normal background levels of red colonies. Sequencing revealed that the mutation in the tumor was a 3-base pair deletion affecting codons 238 and 239. Intragenic deletion within the p53 deoxyribonucleic acid binding domain is uncommon in sporadic tumors but would be entirely consistent with misrepair of a radiation-induced double-strand deoxyribonucleic acid break in this case. CONCLUSION: This is the first case in which a causative underlying genetic event has been identified in a radiation-induced glioblastoma. We infer that mutation of one p53 allele occurred at the time of radiotherapy, and the sudden appearance of the tumor 10 years later occurred after loss of the remaining wild-type allele and/or other genetic alterations, such as chromosome 10 loss and epidermal growth factor receptor gene amplification.

Adolescent↗

PubMed1997

Induction of macrophage migration inhibitory factor messenger ribonucleic acid in rat forebrain by reperfusion.

OBJECTIVE: Macrophage migration inhibitory factor (MIF) is a cytokine that has the potential to immobilize and activate monocytes/macrophages. To examine whether MIF may potentially be involved in the pathogenesis of reperfusion injury of the brain, we investigated the expression of MIF in a rat model of reperfusion. METHODS: A four-vessel occlusion procedure was performed for 30 minutes using male Wistar rats to obtain a moderate reperfusion in the forebrains. Semiquantitatively calibrated reverse-transcription polymerase chain reaction analysis was conducted to examine temporal profiles of messenger ribonucleic acid (mRNA) expression for MIF and macrophage chemoattractant protein 1. MIF protein assays expression was assessed with specific Western blot analysis. For anatomic mapping of MIF, an immunohistochemical study was performed. RESULTS: Reverse-transcription polymerase chain reaction demonstrated that the mRNA level of MIF increased depending on the duration of reperfusion (< or = 24 h) subsequent to global ischemia. The macrophage chemoattractant protein 1 mRNA was also observed to increase after reperfusional stress, but its maximum expression was reached earlier (1 h after the stress) than was MIF mRNA. Increase of MIF protein was also shown by Western blot. MIF-positive staining was observed in the neuronal processes (neuropil) in the cortex and basal growth ganglia of a rat forebrain. CONCLUSION: This protein is up-regulated and may modulate immunological reaction in secondary brain damage after ischemia and reperfusion stress.

Animals↗

PubMed1997

Hemifacial spasm caused by a hemangioma at the geniculate ganglion: case report.

OBJECTIVE AND IMPORTANCE: Hemifacial spasm is rarely caused by facial nerve lesions in the temporal bone. Intratemporal facial nerve hemangiomas may initially present as facial spasm. CLINICAL PRESENTATION: A 30-year-old woman developed right hemifacial spasm. Physicians observed slight weakness on the right side of her face, in addition to the hemifacial spasm, but routine radiological examinations did not detect any abnormal findings along the course of the facial nerve. Although the patient underwent neurovascular decompression, the spasm persisted postoperatively. Two years after surgery, the right facial palsy progressed. Concurrently, the hemifacial spasm diminished. High-resolution computed tomography demonstrated a small mass lesion expanding the cortex of the right petrosal bone involving the geniculate ganglion of the facial nerve. INTERVENTION: The patient underwent a second craniotomy through a subtemporal extradural route, and the tumor was completely removed. A pathological examination demonstrated a cavernous hemangioma. CONCLUSION: Routine radiological examinations may fail to detect small intratemporal facial nerve hemangiomas, particularly at the geniculate ganglion. Therefore, when physicians encounter atypical facial spasm, the intratemporal portion of the facial nerve should be carefully examined using high-resolution computed tomography.

Adult↗

PubMed1997

Role of arabidopsis MYC and MYB homologs in drought- and abscisic acid-regulated gene expression.

In Arabidopsis, the induction of a dehydration-responsive gene, rd22, is mediated by abscisic acid (ABA) and requires protein biosynthesis for ABA-dependent gene expression. Previous experiments established that a 67-bp DNA fragment of the rd22 promoter is sufficient for dehydration- and ABA-induced gene expression and that this DNA fragment contains two closely located putative recognition sites for the basic helix-loop-helix protein MYC and one putative recognition site for MYB. We have carefully analyzed the 67-bp region of the rd22 promoter in transgenic tobacco plants and found that both the first MYC site and the MYB recognition site function as cis-acting elements in the dehydration-induced expression of the rd22 gene. A cDNA encoding a MYC-related DNA binding protein was isolated by DNA-ligand binding screening, using the 67-bp region as a probe, and designated rd22BP1. The rd22BP1 cDNA encodes a 68-kD protein that has a typical DNA binding domain of a basic region helix-loop-helix leucine zipper motif in MYC-related transcription factors. The rd22BP1 protein binds specifically to the first MYC recognition site in the 67-bp fragment. RNA gel blot analysis revealed that transcription of the rd22BP1 gene is induced by dehydration stress and ABA treatment, and its induction precedes that of rd22. We have reported a drought- and ABA-inducible gene that encodes the MYB-related protein ATMYB2. In a transient transactivation experiment using Arabidopsis leaf protoplasts, we demonstrated that both the rd22BP1 and ATMYB2 proteins activate transcription of the rd22 promoter fused to the beta-glucuronidase reporter gene. These results indicate that both the rd22BP1 (MYC) and ATMYB2 (MYB) proteins function as transcriptional activators in the dehydration- and ABA-inducible expression of the rd22 gene.

Abscisic Acid↗

PubMed1997

Radiofrequency catheter ablation of an accessory pathway in dextrocardia.

A 60-year-old woman with situs inversus and paroxysmal supraventricular tachycardias utilizing an AV accessory pathway underwent successful, uncomplicated RF ablation. Using biplane fluoroscopy, accessory pathway catheter ablation in dextrocardia is as safe, easy, and useful as that for normal heart structure cases, and does not require a lengthy procedure.

Catheter Ablation↗

PubMed1997

Neurohumoral and hemodynamic mechanisms of diuresis during atrioventricular nodal reentrant tachycardia.

Thirty-two consecutive patients with paroxysmal supraventricular tachycardias, with previously defined mechanisms of the tachycardias, were interviewed by noninvestigators about whether they experienced symptoms of diuresis during or at the termination of the tachycardias, to test the hypothesis that patients with AV nodal reentrant tachycardia would have a feeling of diuresis, polyuria, or both during or at the termination of the tachycardia. Twelve of the 13 patients with AV nodal reentrant tachycardia (92%), two of the 15 patients with AV reentrant tachycardia (13%), and one of the 4 patients with atrial flutter associated with 2:1 AV conduction (25%) felt diuresis during or at the termination of the tachycardias (AV nodal reentrant tachycardia vs other forms of tachycardia; P < 0.001). In 14 of the 32 patients, the right atrial pressure and plasma atrial natriuretic peptide (ANP) concentration were measured during both the tachycardias and sinus rhythm. The mean right atrial pressure during AV nodal reentrant tachycardia was significantly elevated compared to that during other forms of tachycardia (P < 0.01). The plasma ANP concentration during AV nodal reentrant tachycardia was also elevated significantly compared to that during other forms of tachycardias (P < 0.001). There were no significant differences in the cycle lengths of the tachycardias, age, left atrial dimensions, or the left ventricular ejection fraction between the AV nodal reentrant tachycardia and the other forms of tachycardia. We concluded that the feeling of diuresis during or at the termination of tachycardia was a more common symptom in patients with AV nodal reentrant tachycardia. The higher secretion of plasma ANP from the right atrium might be involved in the mechanism of this symptom.

Atrial Natriuretic Factor↗