Spontaneous shunt between the superior mesenteric vein and the right renal vein caused by portal hypertension.
Explore the source record for details and available documents.
Collateral Circulation↗
Biomedical subjects
H Kikuchi
Publications and source records attributed to H Kikuchi.
[A case of paraneoplastic cerebellar degeneration with resting tremor].
A 65-year-old woman was operated for gastric adenocarcinoma in 1989. Six years later, peritonitis carcinomatosa, swelling of periaortic lymphnodes and high serum CA-125 were discovered. She received chemotherapy with 5-FU and cisplatin resulting in reduction of ascites. In September, 1998, the swelling of left supraclavicular lymphnodes and the elevation of serum CA-125 reappeared. Pathological diagnosis of supraclavicular lymphnodes was adenocarcinoma. Serum CA-125 was normalized by chemotherapy using cisplatin, farumorubicin and endoxan. However, unsteadiness appeared since December 10, 1998 followed by dysarthria and involuntary movement of neck and upper limbs. These symptoms progressed subacutely. The physical examination on admission revealed swelling of left suraclavicular lymphnodes, nystagmus on lateral gaze, saccadic eye movement on smooth pursuit and severe cerebellar ataxia. In addition, resting tremor of 3-4 Hz was observed at right hand, left wrist and neck which tended to increase amplitude by calculation. Similar movements were seen in the left first toe, though the frequency was lower. Brain MRI revealed mild cerebellar atrophy. She was diagnosed as paraneoplastic cerebellar degeneration (PCD) by serum anti Yo antibody and clinical course. The study of HLA showed positive link to A4 without A24. The primary focus of adenocarcinoma in cervical lymphnodes was suggested to be ovary rather than stomach due to the pattern of immunostaining for cytokeratin, CEA and CA125, although no carcinoma was found in ovarium clinically. The feature of this case is a PCD with resting tremor of frequency of 3-4 Hz and negative link to HLA-A24 in Japanese.
Adenocarcinoma↗
[A case of intrasellar meningioma mimicking pituitary adenoma].
The authors report a patient with a rare intrasellar meningioma mimicking pituitary adenoma. A 60-year-old man was admitted to our hospital for evaluation of general fatigue. He had no neurological deficit including visual function. Endocrinological tests revealed panhypopituitarism. The craniogram showed slight enlargement of the sella turcica with thinning of the dorsum sellae. CT scan and MR imaging demonstrated a homogeneously enhanced intrasellar mass with slight suprasellar extension. Partial removal of the mass was performed via the transsphenoidal approach because it was extremely firm and hemorrhagic. Histological diagnosis was transitional meningioma. The patient has been well for two years after surgery without tumor progression on MR imaging. It is mandatory to distinguish intrasellar meningioma from pituitary adenoma preoperatively because of marked difference in their treatment strategies. Despite recent advances in neurodiagnostic imaging, it may still be difficult to differentiate pituitary adenoma from intrasellar meningioma. When we re-evaluated the MR imaging, we recognized that the tumor had demonstrated specific findings, ruling out pituitary adenoma, namely bright and homogeneous enhancement, dense enhancement in the early phase on the dynamic MR study, and flow void signal within the mass. The authors emphasize that careful evaluations of MR imaging will allow the correct preoperative diagnosis in patients with intrasellar meningioma mimicking pituitary macroadenoma.
Adenoma↗
[Stenting for proximal subclavian and brachiocephalic artery occlusion--preliminary results].
The authors report the initial results, between January 1998 and February 2001, of stenting utilizing the brachial approach in seven patients for total occlusions at the following locations: two right subclavian, one brachiocephalic, and five left subclavian arteries. All lesions were associated with subclavian steal syndrome. Indications for the treatment included ischemic symptoms in the affected arm (seven patients), and vertebrobasilar insufficiency (five patients). A total of eight stents were implanted in six occluded arteries, resulting in a 75% procedural success rate. Procedural complications encountered were two subintimal dissections by a 0.035-inch guide wire during recanalization, and one stent dislodgement with migration. There was no stroke, presumably because of the previously reported preventive effect of delayed reversal of a stealing vertebral artery. Follow-up over a mean duration of 11 months revealed no sign or symptom of recurrence in cases with initial technical success. The results of the current study, with a literature survey, indicated that percutaneous transluminal angioplasty with primary stent deployment in an occluded prevertebral segment of the subclavian or the brachiocephalic artery should be considered as an available choice for treatment. Further points, such as some remaining technical and clinical problems, will require more experience and consideration.
Adult↗
[Retrovirus associated myopathy, others].
Explore the source record for details and available documents.
Animals↗
[Problems involved in endovascular embolization of intracranial aneurysms with three-dimensional Guglielmi detachable coils].
We experienced nine cases of intracranial aneurysms which were treated with three-dimensional Guglielmi detachable coils (3D-GDC). 3D-GDC is useful in the construction of the initial frame for the embolization of aneurysms, but it also has certain disadvantages for achieving successful treatment. Nine patients with nine intracranial aneurysms were treated with 3D-GDC for initial framing from October, 1999 to September, 2000 at the National Cardio-Vascular Center, Japan. Angiographically complete and successful occlusion was performed in only three patients. Four patients developed parent artery stenosis due to small loops of the 3D-GDC protruding from the aneurysm. Two patients experienced incomplete occlusion because small loops of the 3D-GDC caused cells to form in the framing, and additional coils could not be inserted into some cells. 3D-GDC is useful as an initial framing coil, but we should be careful when placing additional coils into an aneurysm because we cannot predict the effect of the small loops of 3D-GDC on the embolization of aneurysms.
Aged↗
[Stenting for the occlusive carotid and subclavian arteries in Takayasu arteritis].
The authors report the initial results of stenting in four patients of Takayasu arteritis for 11 occlusive carotid and subclavian arteries between January 1999 and December 2000. The lesions included stenoses of two right subclavian, three right common carotid, two left common carotid, and two left subclavian arteries, and total occlusion of two subclavian arteries. A total of 14 stents were implanted in 10 arterial lesions, resulting in a 91% procedural success rate. One failure was due to inability to cross the total occlusion of the subclavian artery. Procedural complications and problems were pain during balloon angioplasty in three patients, vaso-vagal reflex in two, carotid artery perforation associated with transient horseness in one, and stent migration in one. There was no permanent morbidity. Follow-up over a mean duration of 12 months revealed one symptomatic recurrence of left subclavian stenosis, followed by a successful re-dilatation. The results of the current study indicated that primary stenting is an excellent therapeutic option for the occlusive carotid and subclavian arteries in Takayasu arteritis. A long-term follow-up is required to determine the response or behavior of stented segments of the affected arteries.
Adult↗
[A case of Hirayama's disease successfully treated by anterior cervical decompression and fusion].
The authors report the case of a 16-year-old boy with Hirayama's disease(juvenile muscular atrophy of unilateral upper extremity). The present history began about 6 months previously, when he noticed slowly progressive weakness with atrophy of the left hand and forearm. Neurological examination on admission revealed diffuse distribution of muscular atrophy including the left hypothenar, thenar, forearm, and triceps muscles. However, EMG studies identified neurogenic changes in both upper extremities. There was no long tract sign of objective sensory impairment. Plain spinal radiograms showed abnormal kyphosis of the cervical vertebrae. Cervical MR images in the neutral position demonstrated focal atrophy of the cervical cord at the C 5-6 vertebral levels. When the neck was flexed, the cervical cord was displaced anteriorly and was compressed over the posterior surface of the C 5-6 vertebral bodies. He was diagnosed to have Hirayama's disease(cervical flexion myelopathy). Via an anterior approach, he underwent a C 5 vertebrectomy followed by fixation of C 4-6 vertebral bodies using iliac bone and plate system. He recovered from surgery without any complications and has been well for the past 6 months with remarkable improvement of muscle strength. Application of cervical collar for 3 to 4 years has been generally advocated for the treatment of Hirayama's disease because progression of signs and symptoms is usually expected to cease within several years. However, some patients were reported not to response to conservative treatment for more than 5 years after their onsets. To these patients surgery seems to be beneficial, because it can give rise to permanent stable fixation with much shorter period of external cervical immobilization compared with cervical collar therapy, in which long-term application is frequently unbearable in many patients. In conclusion, the present case emphasizes the importance of surgical treatment in Hirayama's disease not only to improve neurological deficits but regain better quality of life.
Adolescent↗
[An autopsy case of dementia with motor neuron disease accompanying Alzheimer's disease lesion].
We report the case of a 60-year-old man with autopsy-proven dementia with motor neuron disease (D-MND) and Alzheimer's disease lesion. The patient presented with clumsiness of his right hand at the age of 55 years old and subsequently developed dysarthria, weakness and atrophy of his upper limbs. He was unaffectionate towards his family, repeated the same phrase, and showed severe disorientation of time and place. Neurological examination on admission showed not only diffuse lower motor neuron signs, such as weakness, atrophy, fasciculation and areflexia in both upper limbs, but also dementia (HDS-R 9/30). He died of respiratory insufficiency. Neuropathological examination showed mild atrophy of the frontal and temporal lobes and anterior spinal roots. Microscopic examination of cortical sections revealed degenerative changes with simple atrophy and gliosis, and these changes were predominant in layers 1 and 2 of the frontal and temporal cortices. Using immunohistochemical staining, ubiquitin-positive but tau-negative inclusions were frequently found in neurons of the hippocampal granular cell layers and temporal lobes. Many senile plaques and neurofibrillary tangles were present in all sections of the brain. Our final diagnosis was dementia with motor neuron disease accompanying Alzheimer's disease lesion, because of hypoperfusion in the parietal lobe as well as the frontal lobe demonstrated by SPECT, and the presence of many senile plaques and neurofibrillary tangles in the cerebral cortex. Overlapping of pathologically-proven D-MND and Alzheimer's disease lesion is extremely rare, and this case may improve our understanding of the process of neurodegeneration.
Alzheimer Disease↗
Characteristics and biodistribution of cationic liposomes and their DNA complexes.
We have developed some novel liposome formulations for gene transfection. The formulations consisting of O,O'-ditetradecanoyl-N-(alpha-trimethyl ammonio acetyl) diethanolamine chloride (DC-6-14) as a cationic lipid, phospholipid and cholesterol showed effective gene transfection activity in cultured cells with serum and in vivo, i.e., intraperitoneal injection in mice. In this report, the physicochemical characteristics and biodistribution of the liposomes containing DC-6-14 (DC-6-14 liposomes) as a drug (gene) carrier for gene therapy were investigated in vitro and in vivo. DC-6-14 liposome-DNA complexes were usually thought to have positive surface charge. However, depending on the ratio of DNA to liposomes, zeta-potential of the complexes became negative. The diameter of the complexes also depended on the DNA-liposome ratio, and showed a maximum when their surface potential was neutral. When biodistribution of the complexes was determined after intravenous injection, positively charged complexes showed an immediate lung accumulation. On the other hand, negatively charged complexes did not show lung accumulation. These results have suggested that biodistribution of the DNA-liposome complexes, prepared with DC-6-14 liposomes, depends on their surface charge. Therefore, some surface modification of DC-6-14 liposomes may improve the biodistribution and hence the targetability of their DNA complexes.
Animals↗
Infarct tolerance accompanied enhanced BDNF-like immunoreactivity in neuronal nuclei.
A prolonged period (48 h) of cortical spreading depression (CSD) induced resistance against severe focal cerebral ischemia (infarct tolerance), however, the mechanism behind this is unknown. The infarct tolerance was a transient phenomenon; the resistance increased linearly for the initial 12 days, peaking from 12 to 15 days after a preconditioning of CSD, and was decreased thereafter. This study examined the time course of brain-derived neurotrophic factor (BDNF), heat shock protein (hsp)27 and 70, and glial fibrillary acidic protein (GFAP) expressions after CSD in the brain. Immunohistochemical expression of BDNF, hsp27, hsp70, or GFAP following a prolonged period of CSD induced by KCl-infusion, or following NaCl-infusion was analyzed by regional densitometry for 24 days in the rat neocortex. In addition, BDNF protein was measured quantitatively by two-site ELISA assay in the neocortex (n=6 at each time point). The GFAP expression was elevated in astrocytes (compared to the normal level of immunodensity) during the period peaking on day 3-6 following the CSD. The hsp27 immunoreactivity was also elevated in astrocytes from day 1 to 12 peaking on day 1 and 6, but there was no expression of hsp70 during the period following CSD. The immunoreactivity for BDNF was elevated in neurons from day 0 to 18 peaking on day 1 and 6. The protein levels of BDNF in the neocortex were significantly elevated from day 0 to 12 peaking on days 0 and 6 (compared to the normal level) (P<0.05). Using a laser-scanning confocal imaging system, the BDNF-like immunoreactivity in neuronal nuclei was found to increase linearly peaking on day 12, which correlated well with the development of infarct tolerance. The intranuclear increase in BDNF-like protein might contribute to the induction of infarct tolerance in the brain.
Animals↗
A new cationic liposome for efficient gene delivery with serum into cultured human cells: a quantitative analysis using two independent fluorescent probes.
Cationic liposomes are useful to transfer genes into eukaryotic cells in vitro and in vivo. However, liposomes with good transfection efficiency are often cytotoxic, and also require serum-free conditions for optimal activity. In this report, we describe a new formulation of cationic liposome containing DC-6-14, O,O'-ditetradecanoyl-N-(alpha-trimethylammonioacetyl)diethan olamine chloride, dioleoylphosphatidylethanolamine and cholesterol for gene delivery into cultured human cells. This liposome, dispersed in 5% serum-containing growth medium, efficiently delivered a plasmid DNA for GFP (green fluorescent protein) into more than 80% of the cultured human cell hybrids derived from HeLa cells and normal fibroblasts. Flow cytometric analysis revealed that the efficiency of the GFP gene expression was 40-50% in a tumor-suppressed cell hybrid, while it was greatly reduced in the tumorigenic counterpart. The enhanced GFP expression in tumor-suppressed cell hybrids was quantitatively well correlated with a prolonged presence of the plasmid DNA, which had been labeled with another fluorescent probe, ethidium monoazide, within the cells. These results suggest that a newly developed cationic liposome is useful for gene delivery in serum-containing medium into human cells and the stability of the plasmid DNA inside the cell is a crucial step in this liposome-mediated gene expression. The mechanisms by which cationic liposome mediates gene transfer into eukaryotic cells are also discussed.
Cations↗
NADPH oxidase subunit, gp91(phox) homologue, preferentially expressed in human colon epithelial cells.
The NADPH oxidases are a group of plasma membrane-associated enzymes found in a variety of cells. They catalyze the production of superoxide (O(-)(2)) by a one-electron reduction of oxygen, using NADPH as the electron donor. To characterize the expression of this enzyme, two homologues of the NADPH oxidase catalytic subunit, gp91(phox), were cloned from the cDNAs of a human colon cancer cell line, Caco2, and human fetal kidney, using information relating to an expressed sequence tag (EST) from a DNA database. Amino acid identity was 58% (gp91-2) and 56% (gp91-3), respectively, against the catalytic subunit (gp91-1/gp91(phox)) of the NADPH oxidase found in peripheral blood leukocytes. Using the reverse transcription-polymerase chain reaction (RT-PCR) method, the messenger RNA of gp91-2 was detected mainly in the colon (and also in kidney and prostate) among human adult tissues, in the thymus among human fetal tissues, and in the cancer cell lines (HepG2 and Caco2). An expression of gp91-3 was detected in the fetal kidney, and in the cancer cell line (HepG2), but not at all in adult tissues (by the RT-PCR method). In situ hybridization revealed that gp91-2 is located in the absorptive epithelial cells of the adult colon. Neither gp91-2 nor gp91-3 was expressed in peripheral blood leukocytes.
Blotting, Northern↗
Neuroprotection by MAPK/ERK kinase inhibition with U0126 against oxidative stress in a mouse neuronal cell line and rat primary cultured cortical neurons.
Oxidative stress is implicated in the pathogenesis of neuronal degenerative diseases. Oxidative stress has been shown to activate extracellular signal-regulated kinases (ERK)1/2. We investigated the role of these mitogen-activated protein kinases (MAPKs) in oxidative neuronal injury by using a mouse hippocampal cell line (HT22) and rat primary cortical cultures. Here, we show that a novel MAPK/ERK kinase (MEK) specific inhibitor U0126 profoundly protected HT22 cells against oxidative stress induced by glutamate, which was accompanied by an inhibition of phosphorylation of ERK1/2. U0126 also protected rat primary cultured cortical neurons against glutamate or hypoxia. However, U0126 was not protective against death caused by tumor necrosis factor alpha (TNFalpha), A23187, or staurosporine. These results indicate that MEK plays a central role in the neuronal death caused by oxidative stress.
Animals↗
Prevention of rat cerebral aneurysm formation by inhibition of nitric oxide synthase.
BACKGROUND: Cerebral saccular aneurysm is a major cause of subarachnoid hemorrhage, one of the cerebrovascular diseases with the highest mortality. The mechanisms underlying the development of aneurysms, however, still remain unclear. We have made a series of reports on an animal model of experimentally induced cerebral aneurysms that resemble human cerebral aneurysms in their location and morphology, suggesting that the arterial wall degeneration associated with aneurysm formation develops near the apex of arterial bifurcation as a result of an increase in wall shear stress. Using the animal model and human specimens, we examined the role of nitric oxide (NO) in the degenerative changes and cerebral aneurysm formation. METHODS AND RESULTS: Inducible NO synthase (iNOS) was immunohistochemically located at the orifice of human and rat aneurysms. Nitrotyrosine distribution was also seen in the human aneurysm. Although no iNOS immunostaining was found in normal arteries, iNOS immunoreactivity was observed in parallel with the development of early aneurysmal changes in rats. In contrast, during the early development of aneurysm, endothelial NOS immunostaining in the endothelium was weakened compared with that in the control arteries. An NOS inhibitor, aminoguanidine, attenuated both early aneurysmal changes and the incidence of induced aneurysms. A defibrinogenic agent, batroxobin, which may diminish shear stress by reduction of blood viscosity, prevented iNOS induction as well as early aneurysmal changes. CONCLUSIONS: The evidence suggests that NO, particularly that derived from iNOS, is a key requirement for the development of cerebral aneurysm. The iNOS induction may be caused by an increase in shear stress near the apex.
Animals↗
Infarct tolerance induced by intra-cerebral infusion of recombinant brain-derived neurotrophic factor.
Neuronal expression of brain-derived neurotrophic factor (BDNF) has been implicated in the mechanism of infarct tolerance (resistance to stroke) (H. Yanamoto et al., Infarct tolerance accompanied enhanced BDNF-like immunoreactivity in neuronal nuclei, submitted to Brain Res.), a process that takes more than 7 days following a preconditioning of repetitive cortical spreading depression (CSD). To investigate whether an elevated level of BDNF protein in the brain solely protects neurons against temporary focal ischemia, recombinant (r)BDNF was infused into the rat neocortex. Recombinant BDNF (or vehicle: saline) was administered into the left neocortex via an implanted osmotic minipump for 2.5, 7, 10 or 14 days pre-ischemia, during ischemia and for 2 days post-ischemia (8 microgram in total) in male Sprague-Dawley rats (n=6 each). Temporary focal ischemia was induced in the left middle cerebral artery (MCA) territory by three-vessel occlusion of bilateral common carotid arteries (CCAs) and MCA for 2 h, and the cerebral infarct volume was analyzed 2 days after ischemia using TTC staining. Regional cerebral blood flow (rCBF) of the left neocortex was monitored after 14 days of intracerebral administration of BDNF or vehicle (n=10 each). The distribution of BDNF following different periods of rBDNF or vehicle-infusion was analyzed using immunohistochemical techniques (n=5 each). In the groups treated with 8 microgram of rhBDNF for 7, 10, or 14 days pre-ischemia, there were significant reductions of neocortical infarct volume compared to in the control or vehicle-treated groups (p<0.05). In the rCBF study, there was no significant change after the infusion of 8 microgram rhBDNF for 14 days. In the histological study, a wide distribution of BDNF-like immunoreactivity in the neuronal nuclei in the ipsilateral neocortex was demonstrated after the infusion of 8 microgram rhBDNF for 14 days. The BDNF-like immunoreactivity in the neuronal nuclei was enhanced at the time that the resistance to stroke was achieved by direct intra-cerebral infusion of exogenous rBDNF. Elucidating the function of the BDNF-like protein located in the neuronal nuclei should reveal a new strategy for neuroprotection against ischemic brain attack in humans.
Animals↗
Novel acyl alpha-pyronoids, dictyopyrone A, B, and C, from Dictyostelium cellular slime molds.
For the elucidation of the diversity of secondary metabolites of Dictyostelium cellular slime molds, we investigate the constituent of three species of slime molds. From the methanol extract of their fruit bodies, we obtained three novel compounds, dictyopyrone A (1) and B (2) from D. discoideum and D. rhizoposium and dictyopyrone C (3) from D. longosporum. They possess a unique alpha-pyrone moiety with a side chain at the C-3 position. Their relative structures were elucidated by spectral means, and the absolute configuration was confirmed by asymmetric synthesis of 1. Since these compounds were obtained from different species of Dictyostelium slime molds, they may be a type of compound common to this genus.
Animals↗
The molecular structure of hyperthermostable aromatic aminotransferase with novel substrate specificity from Pyrococcus horikoshii.
Aromatic amino acid aminotransferase (ArATPh), which has a melting temperature of 120 degrees C, is one of the most thermostable aminotransferases yet to be discovered. The crystal structure of this aminotransferase from the hyperthermophilic archaeon Pyrococcus horikoshii was determined to a resolution of 2.1 A. ArATPh has a homodimer structure in which each subunit is composed of two domains, in a manner similar to other well characterized aminotransferases. By the least square fit after superposing on a mesophilic ArAT, the ArATPh molecule exhibits a large deviation of the main chain coordinates, three shortened alpha-helices, an elongated loop connecting two domains, and a long loop transformed from an alpha-helix, which are all factors that are likely to contribute to its hyperthermostability. The pyridine ring of the cofactor pyridoxal 5'-phosphate covalently binding to Lys(233) is stacked parallel to F121 on one side and interacts with the geminal dimethyl-CH/pi groups of Val(201) on the other side. This tight stacking against the pyridine ring probably contributes to the hyperthermostability of ArATPh. Compared with other ArATs, ArATPh has a novel substrate specificity, the order of preference being Tyr > Phe > Glu > Trp > His>> Met > Leu > Asp > Asn. Its relatively weak activity against Asp is due to lack of an arginine residue corresponding to Arg(292)* (where the asterisk indicates that this is a residues supplied by the other subunit of the dimer) in pig cytosolic aspartate aminotransferase. The enzyme recognizes the aromatic substrate by hydrophobic interaction with aromatic rings (Phe(121) and Tyr(59)*) and probably recognizes acidic substrates by a hydrophilic interaction involving a hydrogen bond network with Thr(264)*.
Amino Acid Sequence↗