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Biomedical subjects

H Kikuchi

Publications and source records attributed to H Kikuchi.

At least 217 records · Page 12Linked to original sources
PubMed1998

Apoptosis of medial smooth muscle cells in the development of saccular cerebral aneurysms in rats.

BACKGROUND AND PURPOSE: Using an animal model, we examined the role of apoptosis in the disappearance of medial smooth muscle cells (SMCs) during the development and growth of cerebral aneurysms. METHODS: Various degrees of cerebral aneurysms were induced in the right anterior cerebral artery-olfactory artery bifurcations in 65 Sprague-Dawley rats with ligation of the left common carotid artery and renal hypertension. We performed in situ end labeling of fragmented DNA with the lesions in 45 rats and electron microscopic study in the other 20 rats. RESULTS: With in situ end labeling of fragmented DNA, 4+/-3 apoptotic medial SMCs were detected in 35 of the 45 bifurcations. Apoptotic SMCs appeared in the medial layer in the "preaneurysm" group, the site speculated to show an aneurysmal change in the near future (6+/-3), and in the media in the "early aneurysm" group, which showed characteristics such as a small depression (5+/-3). In the "progressive aneurysm" group, they appeared more frequently at the aneurysmal neck (3+/-2) than the dome (1+/-1). By electron microscopic study, shrunken medial SMCs exhibiting morphological apoptotic changes such as chromatin condensation and fragmentation of the cytoplasm and nucleus were observed in the preaneurysm and early aneurysm groups and at the neck portion in the progressive aneurysm group. In the aneurysmal dome, SMCs showed late characteristics of apoptosis such as more advanced nuclear and cytoplasmic condensation and formation of apoptotic bodies. CONCLUSIONS: The present findings indicate that there is an association between apoptosis of medial SMCs and the formation of saccular cerebral aneurysms.

Aneurysm↗
PubMed1998

Differential expression of genes for aromatase and estrogen receptor during the gonadal development in chicken embryos.

In birds, differentiation of embryonic gonads is not as strictly determined by the genetic sex as it is in mammals, and can be influenced by early manipulation with a sex steroid hormone. Thus administration of an aromatase inhibitor induces testis development in the genetic female, and administration of estrogen induces a left ovotestis in the genetic male embryo. Another feature of avian gonadogenesis is that only the left ovary develops in most species. Molecular mechanisms underlying these features at the level of gene expression have not been elucidated. In this paper, we present evidence that a gene for aromatase cytochrome P-450, an enzyme required for the last step in the synthesis of estradiol-17beta, is expressed in medullae of the left and right gonads of a female chicken embryo, but not in those of a male chicken embryo, and that an estrogen receptor gene is expressed only in epithelium (and cortex later, in the female) of the left, not the right, gonad of both sexes, but the expression in the male left gonad is temporary and restricted to an early stage of development. Differential expression of these two genes serves well to explain the above features of gonadal development in birds. Furthermore, in ovo administration of estradiol-17beta from the 5th to the 14th day of incubation does not cause expression of the estrogen receptor gene in the right gonad of chicken embryos of either sex, suggesting that the absence of expression of the estrogen receptor gene in the right gonad is not the result of down-regulation, but may be regarded as an important cause of the unilateral ovarian development.

Animals↗
PubMed1998

Advanced pancreatic cancer successfully treated with continuous infusion of 5-fluorouracil and low-dose cisplatin.

Due to pyloric stenosis in a 59-year-old male with the diagnosis of unresectable pancreatic head cancer, gastro-jejunostomy and cholecysto-jejunostomy were performed. Following the operation, the patient underwent a combination chemotherapy with cisplatin 10 mg/day x 5/week and continuous infusion of 5-fluorouracil 500 mg/day for 4 weeks. After three courses, the tumor size decreased and the serum carcinoembryonic antigen (CEA) level decreased from 89.6 to 4.2 ng/ml without significant adverse effects. During the follow-up, the CEA increased and the patient is now receiving the same treatment, surviving for more than one year.

Adenocarcinoma↗
PubMed1998

Circulatory arrest with profound hypothermia during the surgical treatment of large internal carotid artery aneurysm--case report.

A 43-year-old male presented with a cerebral aneurysm manifesting as right facial paresthesia, without neurological deficit. Angiography revealed a large aneurysm (22 mm) of the left internal carotid artery. Intravascular treatment using placement of a detachable coil was attempted, but the coil did not stay in the aneurysmal cavity and the procedure was abandoned. The patient did not tolerate the transient balloon occlusion test of the left internal carotid artery. Therefore, the aneurysm was clipped through an open craniotomy with profound hypothermia (20 degrees C) with cardiac arrest (24 minutes). The aneurysmal dome was collapsed, allowing easy dissection of the posterior communicating artery. The closed chest method was used during the extracorporeal cardiopulmonary bypass. Postoperative angiography revealed complete neck clipping with preservation of carotid blood flow. The patient recovered well and resumed his employment. Circulatory arrest with hypothermia provides several benefits for the surgical treatment of large and giant aneurysms.

Adult↗
PubMed1998

Large and giant middle to lower basilar trunk aneurysms treated by surgical and interventional neuroradiological methods.

Treatment of large and giant aneurysms of the basilar artery remains difficult and controversial. Three large or giant aneurysms of the lower basilar artery were treated with a combination of surgical and interventional neuroradiological procedures. All patients underwent the balloon occlusion test with hypotensive challenge (blood pressure reduced to 70% of the control value). The third patient did not tolerate the test. In the first patient, both vertebral arteries were occluded through a craniotomy. In the second patient, both the aneurysm and the basilar artery were occluded by detached balloons. In the third patient, one vertebral artery was occluded by surgical clipping and the other by detached helical coils and fiber coils. In spite of anti-coagulation and anti-platelet therapy, postoperative thrombotic or embolic ischemia occurred in the second and third patients. Fibrinolytic therapy promptly corrected the ischemic symptoms, but the second patient developed hemorrhagic complications at the craniotomy area 2 hours later. At follow-up examination, the first patient had only 8th cranial nerve paresis, the second patient who had a hemorrhagic complication was bed-ridden, and the third patient had no deficit. Interventional occlusion requires a longer segment of the parent artery compared to surgical occlusion of the parent artery and might cause occlusion of the perforating arteries. However, selected use of various coils can occlude only a short segment of the parent artery. Thus, the postoperative management of thromboembolic ischemia after the occlusion of the parent artery is easier using the interventional technique.

Adult↗
PubMed1998

Direct anastomotic bypass for cerebrovascular moyamoya disease.

Therapeutic result and pitfalls in the surgical treatment of cerebrovascular moyamoya disease are evaluated. During the recent 15 years, 268 patients with moyamoya disease have been treated in our clinic. Among them, 238 patients showed ischemic symptoms. Superficial temporal artery to middle cerebral artery anastomoses combined with temporal muscle grafting (encephalo-myo-synangiosis) were performed for most of the cases. Complete remission and clinical improvement were obtained in 34.0% and 64.2% of the patients, respectively. Symptomatic aggravation due to ischemic complication followed the operation in five patients (1.9%). Normocapnic control during general anesthesia with sufficient hydration is essential to avoid perioperative ischemic complications. Omental graft was performed in 16 patients. In 13 patients, omental graft was performed for the progressing ischemia in the posterior cerebral artery or anterior cerebral artery distribution. In the other three patients, omental graft was used for marked brain atrophy.

Anastomosis, Surgical↗
PubMed1998

Role of transforming growth factor-beta1 in the pathogenesis of moyamoya disease.

OBJECT: Prominent features of moyamoya disease are intimal thickening of the cerebral arterial trunks and abundant angiogenesis for collateral blood supplies, but its pathogenesis is still unknown. The aim of this study was to test the possibility that transforming growth factor-beta1 (TGFbeta1) may play a role in the pathogenesis of moyamoya disease. METHODS: The authors used reverse transcription-polymerase chain reaction to analyze the expression level of TGFbeta1 in smooth-muscle cells cultured from the superficial temporal arteries (STAs) and measured the serum level of TGFbeta1 by using enzyme-linked immunosorbent assay. Although the STA is not predominantly involved with moyamoya disease, it has been used in studies of the pathogenesis of this disease. In this report, the STAs from six patients with moyamoya disease and four with arteriosclerotic cerebrovascular disease, along with sera from 14 patients with moyamoya disease and 10 normal healthy volunteers, were studied. The expression of TGFbeta1 was significantly higher in cultured smooth-muscle cells derived from the STAs of patients with moyamoya disease than in those derived from the STAs of patients with arteriosclerotic cerebrovascular disease (p < 0.05). The serum level of TGFbeta1 was also significantly higher in patients with moyamoya disease than in controls (p < 0.0005). CONCLUSIONS: Taking into account the functional roles of TGFbeta1 in the expression of connective tissue genes and angiogenesis, these investigators suggest that TGFbeta1 is associated with the pathogenesis of moyamoya disease, including abundant neovascularization, although their findings do not necessarily mean that TGFbeta1 is a causative factor in this disease.

Adolescent↗
PubMed1998

[Lymphoma associated hemophagocytic syndrome with plasmacytosis in the bone marrow and hypergammaglobulinemia].

A 72-year-old woman was admitted to our hospital because of fever, anemia and thrombocytopenia in March 1997. Laboratory findings showed elevated serum LDH levels and polyclonal gammopathy. Bone marrow aspiration samples revealed hemophagocytosis and plasmacytosis. Although serum interleukin-6 was elevated, serum interferon-lambda and tumor necrosis factor-alpha were below detectable limits. Magnetic resonance images disclosed a tumor in the patient's pelvic cavity. The tumor was resected and diagnosed as non-Hodgkin's lymphoma. The patient was treated with combination chemotherapy and has remained in complete remission. Also, histiocyte and plasma cell counts in the bone marrow fell significantly and the serum interleukin-6 level returned to the normal range. We reasoned that lymphoma cells may have induced plasmacytosis in the bone marrow and polyclonal gammopathy accompanied by hemophagocytic syndrome.

Aged↗
PubMed1998

[A case of glomerulonephritis with singular high titer of anticardiolipin antibody].

We report here a case of severe membranoproliferative glomerulonephritis with a singular high titer of anticardiolipin antibody (aCL). A 19-year-old Japanese female was admitted to Tsukuba Gakuen Hospital after complaining of general edema for 5 months. She had no past history of thrombosis, thrombocytopenia, or spontaneous abortion. Laboratory findings revealed that she had nephrotic syndrome and moderate renal dysfunction. Immunological test showed a high titer of aCL with a high-normal limit of antinuclear antibody, negativity for anti-beta(2) glycoprotein I antibody and negativity for anti-DNA antibody. In the renal biopsy tissue, most glomeruli showed global sclerosis and the remaining glomeruli revealed membranoproliferative change with crescent formation. Steroid therapy with warfarin and dipyridamole was effective and her renal function improved gradually. This case lacked the typical symptoms of primary antiphospholipid syndrome and did not satisfy the criteria of SLE. In spite of these findings, the singular high titer of aCL with membranoproliferative glomerulonephritis characterized this case.

Adult↗
PubMed1998

[Clinical study of AJ-007 (bupivacaine) in spinal anesthesia--investigation of clinical dosage of isobaric and hyperbaric formulations].

Spinal anesthesia with two types of 0.5% bupivacaine hydrochloride solution, isobaric AJ-007 I and hyperbalic AJ-007 H, was studied clinically in 106 surgical patients with collaboration of 7 university hospitals. The following results were obtained. 1) Successful analgesia with motor block on abdominal wall and legs could be induced by dosages of 2.0 ml, 3.0 ml and 4.0 ml of either of the two solutions. 2) With isobaric solutions, the duration of the block was prolonged dose dependently. Anesthetic levels tended to increase and onset times of the block tended to decrease, with increasing dosage. 3) Hyperbalic solutions tended to produce higher levels of the block more rapidly. However, the duration of the block seemed to be shorter than that achieved by isobaric solutions. 4) The incidence of hypotension and bradycardia was similar to that observed in ordinary clinical spinal anesthesia. In one young male, a high level (C 2) of anesthesia was achieved after administration of 4.0 ml of hyperbaric solution. This patient was managed uneventfully under general anesthesia during the surgery. These results indicate that these two solutions of 0.5% bupivacaine are useful for spinal anesthesia.

Adult↗
PubMed1998

[An autopsy case of rhino-orbito-cerebral mucormycosis associated with multiple cranial nerve palsy and subsequent subarachnoid hemorrhage].

We report an autopsy case of 53-year-old male with poor controlled diabetes mellitus and hepatocellular carcinoma who developed rhino-orbito-cerebral mucormycosis. Initial complaints were epistaxis and headache followed by a sudden blindness, the 2nd through 7th cranial nerve palsy and diabetes inspidus. Laboratory data revealed that he had liver cirrhosis due to hepatitis C virus infection and diabetes mellitus. Head CT and MRI showed no significant findings. Eleven days after the onset, he died of subarachnoid hemorrhage. The postmortem examination revealed severe infiltration of numerous mucors in the sphenoid sinus, cavernous sinus and bilateral internal carotid arteries. Severe granulomatous vasculitis was seen in the cavernous portion of the bilateral internal carotid arteries. Thus, we considered that this case had been caused by the infiltration of mucors to the cavernous sinus, resulting in the obstruction of ophthalmic arteries. Rupture of the right internal carotid artery was seen at the branching portion of the ophthalmic artery, demonstrating the cause of his death. We would like to emphasize that rhino-orbito-cerebral mucormycosis should be ruled out if we examine a nondiagnostic case of diabetes mellitus or immunosuppressed disease associated with rapid multiple cranial nerve palsy following the orbital symptoms.

Abducens Nerve↗
PubMed1998

Expression of thioredoxin is enhanced in atherosclerotic plaques and during neointima formation in rat arteries.

Thioredoxin (TRX) is an intracellular enzyme that has a variety of activities as a hydrogen donor for various intracellular molecules. In the present study, we investigated the role of TRX in atherosclerotic lesions. In human atherosclerotic specimens, TRX and TRX mRNA were enhanced in endothelial cells and macrophages in the atherosclerotic plaques. In balloon-injured rat arteries, TRX expression increased from 2 to 6 weeks after injury; TRX was induced in the neointimal regenerating endothelial cells. In hybridization experiments, TRX mRNA was also induced from 2 to 6 weeks in the endothelium. In this model, inducible nitric oxide synthase immunoreactivity in the neointimal smooth muscle cells and endothelial cells increased from 2 to 6 weeks after surgical procedures were performed. During this period, the immunoreactivity of nitrotyrosine, which is a marker of nitric oxide (NO) production, also increased. We focused on the association between TRX and NO. In vitro studies using a murine endothelial cell line showed TRX and TRX mRNA induction by NO and peroxynitrite donors. Enhanced expression of TRX was detected mainly within the cytoplasm in immunocytochemical studies. In addition, TRX-transfected cells showed resistance to peroxynitrite-induced cytotoxicity. These findings indicate that TRX and the cellular redox state modified by TRX play a crucial role in arterial neointima formation in atherosclerosis.

Animals↗
PubMed1998

[Serum selenium contents and the risk of cancer].

To investigate the relationship between serum Se contents and the risk of cancer, 4857 serum samples were obtained from cancerous (2730) and non-cancerous patients (2127). In this cohort, the incidence of cancer in the non-cancerous patients was followed for the subsequent 3 years. The serum Se level of non-cancerous patients who later developed cancer during the 3 years was determined and compared with that of the non-cancerous patients. A high incidence of cancer was observed in the lower serum Se patients of the non-cancerous group. The serum Se levels of cancerous patients were significantly lower than in non-cancerous patients. These results suggest that the low serum Se level in cancerous patients may not be induced by the tumor but it was more likely already present before the tumor. To calculate the odds ratio, cancerous and non-cancerous patients were divided into group of less than 110 ppb and more than 111 ppb group in serum Se. The odds ratio was estimated to be 1.95, suggesting the high risk of cancer in the low serum Se group.

Adult↗
PubMed1997

3-nitropropionic acid induces poly(ADP-ribosyl)ation and apoptosis related gene expression in the striatum in vivo.

Impaired energy metabolism plays an important role in neuronal cell death after brain ischemia, and apoptosis has been implicated in cell death induced by metabolic impairment. In the present study, metabolic impairment was induced by 3-nitropropionic acid (3-NP), an irreversible inhibitor of succinate dehydrogenase. In order to clarify the involvement of poly(ADP-ribosyl)ation and apoptotic pathway in 3-NP induced cell death, we examined poly(ADP-ribosyl)ation and the apoptosis related gene protein expression after systemic administration of 3-NP by immunohistochemistry. Poly(ADP-ribosyl)ation was evidently detected in the striatal lesion but not in any other region. Immunoreactive ratio of Bcl-2 to Bax significantly increased both in the striatum and cortex. The data suggest that striatal cell death involves poly(ADP-ribosyl)ation and also apoptotic pathway in part following administration of 3-NP.

Animals↗
PubMed1997

Adenovirus-mediated gene transfer of basic fibroblast growth factor induces in vitro angiogenesis.

To investigate the possibility of adenovirus-mediated gene transfer in the treatment of vascular occlusive diseases, we constructed a replication-deficient recombinant adenovirus vector coding for human basic fibroblast growth factor (bFGF) and examined its effect on the proliferation and differentiation of vascular endothelial cells in vitro. Human umbilical vein endothelial cells (HUVECs) were successfully infected with high efficiency and expressed 18 kD protein which is immunoreactive to anti-bFGF monoclonal antibody. This protein was accumulated mainly in the nuclei of the cells, but was also detected in the culture medium although the complimentary DNA (cDNA) did not contain the classical secreting signal sequence. The proliferation assay of HUVECs infected with bFGF-expressing adenovirus revealed a significant increase in cell number over control. Infection with this virus also enhanced tubular formation of HUVECs on reconstituted basement membrane. Neovascularization and the formation of collateral vessels play important roles in minimizing tissue damage in ischemic disorders. These results imply that the use of bFGF-expressing recombinant adenovirus may be a suitable in vivo gene therapy for ischemic diseases.

Adenoviridae↗
PubMed1997

Collateral projections of single neurons in the posterior thalamic region to both the temporal cortex and the amygdala: a fluorescent retrograde double-labeling study in the rat.

It has been reported that the acoustic thalamus of the rat sends projection fibers to both the temporal cortical areas and the lateral amygdaloid nucleus to mediate conditioned emotional responses to an acoustic stimulus. In the present study, fluorescent retrograde double labeling with Fast Blue and Diamidino Yellow has been used in the rat to examine whether single neurons in the posterior thalamic region send axon collaterals to both the temporal cortical areas and lateral amygdaloid nucleus. One of the tracers was injected into the lateral amygdaloid nucleus and the other into the temporal cortical areas close to the rhinal sulcus. Neurons double-labeled with both tracers were found mainly in the posterior intralaminar nucleus and suprageniculate nucleus, and to a lesser extent in the subparafascicular nucleus and medial division of the medial geniculate nucleus. No double-labeled neurons were seen in either the dorsal or ventral division of the medial geniculate nucleus. When one of the tracers was injected into the lateral amygdaloid nucleus and the other into either the dorsal portion of the temporal cortex, the dorsal portion of the entorhinal cortex, or the posterior agranular insular cortex, no double-labeled neurons were found in the posterior thalamic region. The present results indicate that a substantial number of single neurons in the acoustic thalamus project to both the limbic cortical areas and lateral amygdaloid nucleus by way of axon collaterals. These neurons may be implicated in affective and autonomic components of responses to multi-sensory stimuli, including acoustic ones.

Amygdala↗
PubMed1997

A neuroblastoma cell line derived from a case detected through a mass screening system in Japan: a case report including the biologic and phenotypic characteristics of the cell line.

BACKGROUND: A mass screening system in Japan, which involves measuring urinary catecholamine metabolites, has resulted in an increasing number of cases of neuroblastoma, most of which have favorable biologic properties and some of which are associated with tumor regression or involution. At the time this study was begun, the characteristics and biologic nature of the neuroblastomas had not been fully defined, because a cell line had not yet been established with tumor tissue taken from a neuroblastoma detected in the mass screening. METHODS: The authors established a cell line by tissue culture for over 50 generations from a neuroblastoma found during mass screening, which was characterized by favorable histology, with a triploid DNA stemline and without N-myc gene amplification. The morphologic and biologic characteristics of the new cell line were investigated in vitro. RESULTS: The cell line, designated MASS-NB-SCH-1, has neuronal properties, such as neurite-like processes and neurofilaments, as well as the expression of vimentin and fibronectin in studies of the cell morphology and immunohistochemistry. Karyotype analysis detected the presence of 42-46 chromosomes, with a deletion of the short arm of 1 of the 3 copies of chromosome 1. DNA ploidy was near-diploid in association with 20-fold amplification of N-myc genes. CONCLUSIONS: The cell line has a nature distinct from the original tumor tissue. It may be characterized by phenotypic change caused by clonal selection or evolution of aggressive, proliferative properties in vitro. This cell line will be a useful model to investigate the properties of the neuroblastoma in relation to the N-myc amplification mechanism.

Biology↗