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Biomedical subjects

Y Kikuchi

Publications and source records attributed to Y Kikuchi.

At least 199 records · Page 11Linked to original sources

[Axillary artery perfusion for the extensive arterial vascular disease].

Usefulness of axillar artery perfusion for the cases with severe systematic atherosclerosis was reported. It is generally accepted that the femoral artery is a common arterial cannulation site when performing the surgery of ascending aorta and total aortic arch. However, atheroembolism is one of the most severe complication for the patients with extensive arterial vascular disease by using femoral arterial perfusion. Axillar artery perfusion can prevent these complications, and the perfusion through the artificial graft anastomosed to the axillar artery can also avoid the malperfusion of the vertebral artery and axillar artery. We concluded that the axillar artery perfusion via artificial graft is useful alternative for aortic surgery.

Aged↗

[Mitral valve annuloplasty with U-shaped flexible band using Duran ring].

To preserve the physiologic function and correct annular dilatation, U-shaped flexible band was applied for mitral valve annuloplasty in 6 cases. U-shaped flexible band was made by cutting Duran ring to the proper length of posterior annulus using Carpentier-Edwards ring sizer. Echocardiographic mitral regurgitation decreased from 3.8 +/- 0.4 to 0.7 +/- 0.5 after repair. All patients discharged without any complications. This annuloplasty method is effective for mitral insufficiency.

Aged↗

Gains of 1q21-q22 and 13q12-q14 are potential indicators for resistance to cisplatin-based chemotherapy in ovarian cancer patients.

The mechanism of drug resistance in ovarian cancer is multifactorial, and accumulation of multiple genetic changes may lead to the drug-resistant phenotype. In our attempt to find characteristic genetic changes in drug-resistant tumors, we screened the whole genome for gene aberrations in 28 primary ovarian cancers using the comparative genomic hybridization method. These cancers included 14 tumors from patients who did not respond to cisplatin-based combination chemotherapy and 14 tumors from patients who had complete response to the chemotherapy. We found gains in chromosomal regions 1q21-q22 and 13q12-q14 to be related to the drug-resistant phenotype in ovarian cancer patients. Several genes encoding transcription factors, oncogenes, cell cycle regulators, and regulators of the apoptotic pathway are located on these regions of the chromosomes, and these genes are potential modulators for toxic insults in cancer cells. This is the first report that shows the relationship between certain genomic aberrations and clinical resistance to cisplatin-based chemotherapy in ovarian cancer patients based on the comparative genomic hybridization analysis. Present findings suggest that these chromosomal gains may be potential indicators for prediction of resistance in ovarian cancer patients before cisplatin-based chemotherapy.

Antineoplastic Agents↗

[Remission due to CYVADIC chemotherapy of primary leiomyosarcoma derived from mesentelium of the sigmoid colon: a case report].

We report a case of leiomyosarcoma of mesenthelium origin, which was successfully treated with a combination of cyclophosphamide, vincristine, adriamycin and dacarbazine (CYVADIC). A 56-year-old woman received three courses of adjuvant CYVADIC chemotherapy after initial surgery consisting of tumorectomy, sigmoidectomy, descending colostomy, cystectomy and ureterostomy. A six-month disease-free period was attained obtained. A recurrent tumor showed remarkable reduction after three courses of CYVADIC chemotherapy. This case may be the first report of successful chemotherapy against a leiomyosarcoma of mesenthelium origin in Japan.

Antineoplastic Combined Chemotherapy Protocols↗

[Graft replacement from ascending aorta to descending aorta with endovascular stent graft under median sternotomy].

We reported a 62-year-old man with DeBakey IIIa dissecting aortic aneurysm involving distal aortic arch who underwent graft replacement from ascending to descending aorta using a endovascular stent graft. Median sternotomy was carried out, because of severe pleural adhesion. Endovascular stent graft composed of 30 mm Gianturco Z stent and 24 mm woven Dacron graft was inserted to descending aorta with the aid of hypothermia, systemic circulation arrest and selective cerebral perfusion. Transesophageal echocardiography was used to measure the diameter and the length of descending aorta and the graft. And ascending and total aortic arch replacement was performed with four branched woven Dacron graft. Postoperative chest CT and aortography showed satisfactory reconstruction with the thrombosed false lumens. We think placement of stent graft to descending aorta through median sternotomy is useful method when left thoracotomy is impossible or distal anastomotic site is too far for the anastomosis.

Aortic Dissection↗

[A case with posterior column ataxia associated with cerebellar ataxia and sensory neuropathy].

The patient was a 72-year-old man who had a history of subtotal gastrectomy for gastric ulcer at age of 37 years. He had no familial history of hereditary disorders. In 1980 he noticed mild ataxic gait which exaggerated while he closed eyes. The symptoms increased gradually, and four years later he noticed hypoesthesia of his soles. In 1983 he was admitted to the National Center Hospital for Mental, Nervous and Muscular Disorders for the first time. Neurological examination revealed dysarthria, ataxic gait, disturbance of coordination to a slight degree, and muscle strength of the upper and lower limbs were in normal range. Mild hypoesthesia of pain and temperature sensation, and marked decrease of deep sensation and vibration of the lower extremities were demonstrated. Romberg sign was positive. EMG studies revealed low amplitude of action potential and normal motor nerve conduction velocity. Biopsy of the sural nerve showed marked decrease of both large and small myelinated fibers. In 1998 he was admitted second time for the further examination. Laboratory examination including routine blood examination, blood chemistry including CRP, TPHA, vitamin B1, B2, B12, A, E, K, hexosaminidase A in leucocyte were in normal range. CSF was normal. Genetic studies including SCA 1, 2, 3, 6, DRPLA, CMT1A, CMTX 1 were all negative. MCV of lower limbs was in normal range, though SCV was not evoked in the upper and lower limbs. MRI studies showed mild atrophy of the bilateral lobulus of the cerebellum which was not so much changed in the last 5 years. The clinical symptoms revealed dominant posterior column disturbance, ataxia and sensory neuropathy. These combination was not described in the previous literature, and this case may be a new variant of the spinocerebellar degeneration.

Aged↗

The PY-motif of Bul1 protein is essential for growth of Saccharomyces cerevisiae under various stress conditions.

The previously identified BUL1 gene was found to encode a protein bound to Rsp5-ubiquitin ligase in budding yeast. We have identified the BUL2 gene as a functional homologue of BUL1. The bul1 bul2 double disruptant was sensitive to various stresses, such as high temperature, salts, and a non-fermentable carbon source. Each Bul protein has a putative PY-motif that has been predicted to interact with one of three WW-domains of Rsp5. A mutant Bul1 containing an altered PY-motif was defective in ability to bind to Rsp5 in the two-hybrid system and hardly co-immunoprecipitated with Rsp5. Furthermore, the mutant was not able to overcome all growth defects of the double disruptant. Thus, Bul proteins are essential for growth in various stress conditions, and their functions are mediated through the PY-motif, probably by binding to Rsp5.

Adaptor Proteins, Signal Transducing↗

Sensitive and specific method for the determination of josamycin in human plasma by liquid chromatography-mass spectrometry.

A highly sensitive and specific method for the determination of josamycin in human plasma by LC-MS was developed and validated. Josamycin was extracted from human plasma by a single-step liquid-liquid extraction and analyzed by LC-MS via an electrospray ionization interface. Selected ion monitoring was used to detect josamycin and its internal standard. The intra-day precision and accuracy, expressed as C.V. and R.E., ranged from 2.8% to 13.5% and -10.3% to 7.6%, respectively. The lower limit of detection was 0.1 ng/ml and the lower limit of quantitation was set at 1 ng/ml when 0.5 ml of plasma was used. No endogenous interference was observed in human plasma obtained from drug-free volunteers.

Anti-Bacterial Agents↗

Temporal process from receptors to higher brain in taste detection studied by gustatory-evoked magnetic fields and reaction times.

Using magnetoencephalography (MEG) and a taste stimulator with rapid-rise time, we previously located the primary gustatory area in the human cerebral cortex and also investigated the relation between the onset latency of the gustatory-evoked magnetic fields (GEM) and reaction times (RT) in different taste qualities. In the present study, we investigated the temporal process from receptors to the higher brain in taste detection based on the results of the GEM and RT of different tastes. We used 100 mM, 300 mM and 1 M NaCl and 3 mM saccharine. The duration of each stimulus was 400 ms. The interstimulus interval was approximately 30 s. The temperature of both taste solution and deionized water was maintained the same as that of the tongue. Four subjects participated in this experiment. The 64-channel whole-head SQUID system (CTF Systems Inc., Canada) was used to measure GEM. The sampling rate was 250 Hz, and the low-pass filter was 40 Hz. In each subject, GEM and RT to a given taste were measured separately by applying 40 trials of stimulation. After each trial of both measurements, subjects showed a perceived intensity by using their fingers. In the GEM study, the trials contaminated with eye movements were rejected and the remaining trials were averaged. Averaged GEM were super-imposed on the same sheet with all 64 channels to measure the onset latency of GEM from the stimulus onset. RT and onset latencies of GEM were longer for saccharine than NaCl, and the value of RT minus the onset latency of GEM from RT, presumably indicating the time for higher brain process plus motor process, did not differ between 3 mM saccharine and 1 M NaCl. With increased concentrations of NaCl, RT became shorter, but onset latencies of GEM remained constant. Sweet taste took a longer time than salty taste at receptor process including the time for diffusion to receptors.

Cerebral Cortex↗

Molecular cloning of a novel member of the eukaryotic polypeptide chain-releasing factors (eRF). Its identification as eRF3 interacting with eRF1.

Yeast GST1 gene, whose product is a GTP-binding protein structurally related to polypeptide chain elongation factor-1alpha (EF1alpha), was first described to be essential for the G1 to S phase transition (GSPT) of the cell cycle, and the product was recently reported to function as a polypeptide chain release factor 3 (eRF3) in yeast. Although we previously cloned a human homologue (renamed as GSPT1) of the yeast gene, it has remained to be determined whether GSPT1 also functions as eRF3 or if another GSPT may have such a function in mammalian cells. In the present study, we isolated two mouse GSPT genes, the counterpart of human GSPT1 and a novel member of the GSPT gene family, GSPT2. Both the mouse GSPTs had a two-domain structure characterized as an amino-terminal no-homologous region (approximately 200 amino acids) and a carboxyl-terminal conserved eukaryotic elongation factor-1alpha-like domain (428 amino acids). Messenger RNAs of the two GSPTs could be detected in all mouse tissues surveyed, although the level of GSPT2 message appeared to be relatively abundant in the brain. The mouse GSPT1 was expressed in a proliferation-dependent manner in Swiss 3T3 cells, whereas the expression of GSPT2 was constant during the cell-cycle progression. Immunoprecipitation assays in COS-7 cells expressing flag epitope-tagged proteins demonstrated that not only GSPT1 but also GSPT2 was capable of interacting with eRF1. Such interaction between GSPT2 and eRF1 was also confirmed by yeast two-hybrid analysis. Taken together, these data indicated that the novel GSPT2 may interact with eRF1 to function as eRF3 in mammalian cells.

Amino Acid Sequence↗

Mass screening for neuroblastoma targeting children age 14 months in Sapporo City: a preliminary report.

BACKGROUND: In Sapporo City a mass screening program for neuroblastoma targeting children age 6 months (6-MS) was initially introduced in 1981. Since April 1991, an additional program has been implemented, aimed at children age 14 months (14-MS). METHODS: High performance liquid chromatography was employed in the 14-MS. Identification of cases was dependent on the Registry of Childhood Malignancies in the Hokkaido Prefecture. RESULTS: Of the 85,783 live births in Sapporo City during the period 1990-1994, a total of 56,444 participated in the 14-MS (compliance rate, 65.8%). By the end of 1996, of 48,448 children who had previously taken part in the 6-MS, 6 cases were identified in the 14-MS, and 1 additional case screened negative but was later diagnosed clinically. Two more cases were detected in the 14-MS among the 7996 children who had not participated in the 6-MS. Though the incidence of cases identified by the 14-MS was much higher than expected, several true-positive cases had unfavorable histology (as defined by Shimada's classification), a high dopamine level, and/or a high homovanillic acid/vanillylmandelic acid ratio. CONCLUSIONS: Mass screening of children age 14 months for neuroblastoma detects cases missed or unscreened at age 6 months, though the detection rate appears to be in excess of what would be expected from natural incidence.

Cross-Sectional Studies↗

Temporal structure of implicit motor imagery in visual hand-shape discrimination as revealed by MEG.

We investigated the spatio-temporal brain activity on the time scale of several milliseconds related to the mental rotation task requiring judgements of hand orientation, using a whole-cortex MEG (magnetoencephalography) system. Neuronal activity in the visual cortex was observed approximately 100-200 ms from stimulus onset, and that in inferior parietal lobe followed (after 200 ms). Both of these activities showed a contralateral dominance to visual stimulus hemifield. Premotor activity started later than the inferior parietal lobe activity, and these activities partially overlapped. Activity in primary motor and/or motosensory areas was observed in some subjects. The whole-cortex neuromagnetic measurements provided the time course of activity in the human brain associated with the implicit motor imagery: visual cortex-->inferior parietal lobe<-->premotor cortex. This process is considered to be the transformation process of retinotopic locations into a body-centered reference frame necessary for the mental rotation task.

Adult↗

Neurotrophins regulate the function of cultured microglia.

Although the physiological role of neurotrophins in neuronal development and survival has been extensively investigated, their role in glial cell physiology remains to be elucidated. In the present study, we investigated the effects of neurotrophins on cultured microglia from newborn rat brain. All of the neurotrophins tested nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4), increased the secretion of plasminogen and urokinase type-plasminogen activator and specific activity of acid phosphatase, but suppressed the release of constitutively-produced and lipopolysaccharide-stimulated nitric oxide (NO) from microglia. The reverse transcription-polymerase chain reaction, immunocytochemical staining, and Western blotting revealed that cultured microglia express Trk A, B, and C, and low-affinity NGF receptor, LNGFRp75. Neurotrophin was found to phosphorylate Trk A and B, and the neurotrophin-induced enhancement of plasminogen-secretion was suppressed by protein kinase inhibitor, K252a. Furthermore, neurotrophins caused an activation of transcription factor, NF-kappaB. These results indicate that the neurotrophin family regulate the function of microglia through Trk and/or LNGFRp75-mediated signal transduction.

5'-Nucleotidase↗