Search PubMed⌕ Search

Biomedical subjects

K Kaneko

Publications and source records attributed to K Kaneko.

At least 37 records · Page 2Linked to original sources
PubMed2004

Crystallographic orientation contrast associated with Ga+ ion channelling for Fe and Cu in focused ion beam method.

In this study, Cu and Fe single crystals are used to examine the change in secondary electron intensity associated with Ga(+) ion channelling in a focused ion beam (FIB) system. The single crystals having three different orientations are tilted with respect to the beam incidence and the resulting variation in the secondary electron intensity is measured through the variation in brightness of the crystals. It is shown that intensity minima appear at the beam directions normal to the lower indices of the crystal orientations. The appearance of the intensity minima including the magnitude of the minima is consistent with the prediction based on the event of ion channelling in the crystal and is affected by the crystal structure. The effect of background on the intensity minima is discussed in this study. It is suggested that the presence of the intensity minima may be used to identify a crystal orientation including a crystal structure.

Copper↗
PubMed2004

Self-expandable metallic stents for palliation of malignant esophageal obstruction: special reference to quality of life and survival of patients.

SUMMARY. Self-expandable metallic stents (EMS) provide a common option for malignant esophageal stenosis because of the low complication rate and high dysphagia improvement rate. However, there are few studies on the functional duration of EMS and the extent of improvement of the quality of life. We retrospectively analyzed 18 patients who received EMSs in our division from 1996 to 2002. The median duration of possible food intake and the median survival period were 94.5 and 108 days. The median duration of domiciliary treatment was 56 days. Six of the 18 patients were not discharged from hospital after EMS insertion. The Karnofsky index was found to be a significant determinant of the feasibility of domiciliary treatment. One-third of the patients are incapable of obtaining the benefits of the palliative therapy. EMS deployment should be prudently selected for patients exhibiting low performance status.

Adult↗
PubMed2004

Choline acetyltransferase activity and evoked spinal cord potentials for diagnosis of brachial plexus injury.

The purpose of this study is to investigate the diagnostic value of evoked spinal cord potentials (ESCPs) and choline acetyltransferase (CAT) activity during exploration of injuries to the brachial plexus. We assessed 25 spinal roots in 19 patients. The results of the two investigations were consistent in all except two roots. Although assessment of ESCPs is easy and quick, it mainly records the nerve potentials along the sensory pathway. Although measurement of CAT activity needs a specimen of the nerve and the availability of a radioisotope laboratory, it gives direct information regarding the motor function of ventral spinal roots. These two techniques should be complementary to each other in order to achieve a more accurate diagnosis.

Adolescent↗
PubMed2004

Cortical potentials associated with voluntary, reflex, and spontaneous blinks as bilateral simultaneous eyelid movement.

Movement-related cortical potentials (MRCPs) associated with the contraction of m. orbicularis oculi related to three types of blinks (voluntary, reflex, and spontaneous) were measured for 12 normal subjects. The purpose of the present study was to estimate the role of the cerebral cortex in close association with the blinks caused by bilateral simultaneous eyelid movements. MRCPs were recorded by surface electrodes placed over the frontal to the parietal regions. The mean amplitude and the duration of the MRCPs for the three types of blinks were evaluated by an averaging technique for each subject. MRCPs for the voluntary blinks were evoked in all subjects. For the reflex and the spontaneous blinks, however, a clear negative rising deflection from the baseline was not obtained. The maximum amplitude of the MRCPs for the voluntary blinks was localized at the vertex region, though there was no significant difference between the durations of the MRCPs for the vertex region and for the other regions. Moreover, the positive potential following the voluntary and the spontaneous blinks was recognized in the parietal region. These results suggest that only the voluntary blinks are caused by the neural activation of the supplementary motor area (SMA), and in addition, the neural activation related to visual recognition is considered to be elicited by the voluntary and the spontaneous blinks.

Adult↗
PubMed2004

Abdominal aortic aneurysm with left-sided inferior vena cava. Report of a case.

The combination of abdominal aortic aneurysms and congenital anomalies of the inferior vena cava and its tributaries, such as double inferior vena cava, left-sided inferior vena cava, circumaortic renal collar, and retroaortic renal vein, are very rare but of clinical importance to vascular surgeons since these conditions can increase the difficulty of aneurysm resection as well as the risk of venous injury and subsequent excessive bleeding. This report describes a case of an abdominal aortic aneurysm with a left-sided inferior vena cava, and reviews of the incidence, diagnosis, and treatment of these conditions.

Aged↗
PubMed2003

No major tumorigenic role for beta-catenin in serrated as opposed to conventional colorectal adenomas.

Intracellular redistribution of beta-catenin through mutation of the adenomatous polyposis coli (APC) gene has been proposed as an early tumorigenic event in most colorectal tumours. In serrated adenoma (SA), a newly recognised subtype of colorectal adenoma, APC mutations are uncommon, and the contribution of beta-catenin to tumorigenesis remains unclear. We compared intracellular localisation of beta-catenin and presence of mutations in exon 3 of beta-catenin between 45 SAs, with 71 conventional adenomas (CADs), and eight carcinomas invading the submucosa (SCAs). Widespread or focal nuclear beta-catenin expression was demonstrated in 7% of SAs (three out of 45), 61% of CADs (43 out of 71), and 88% of SCAs (seven out of eight). Cytoplasmic immunostaining for beta-catenin was demonstrated in 16% of SAs (seven out of 45), 77% of CADs (55 out of 71), and 88% of SCAs (seven out of eight). No mutation in exon 3 of beta-catenin was found in SAs or SCAs, while 7% of CADs (five out of 71) had beta-catenin mutations. No nuclear or cytoplasmic expression of beta-catenin was observed in the hyperplastic or conventionally adenomatous epithelium of mixed-type SAs. These findings suggest that beta-catenin mutation is unlikely to contribute to the tumorigenesis in SA, and that intracellular localisation of beta-catenin may not be associated with an early event of the tumour progression in most SAs.

Adenoma↗
PubMed2003

Definitive chemoradiotherapy for patients with malignant stricture due to T3 or T4 squamous cell carcinoma of the oesophagus.

We retrospectively investigated the efficacy and feasibility of concurrent chemoradiotherapy for patients with severe dysphagia caused by oesophageal squamous cell carcinoma. Concurrent chemoradiotherapy was performed in 57 patients with T3 or T4 disease containing M1 lymph node (LYM) disease. Chemotherapy consisted of protracted infusion of 5-fluorouracil (5-FU) 400 mg m(-2) 24 h(-1) on days 1-5 and 8-12, combined with 2-h infusion of cisplatin (CDDP) 40 mg m(-2) on days 1 and 8. Radiation treatment at a dose of 30 Gy in 15 fractions of the mediastinum was administered concomitantly with chemotherapy. A course schedule with 3-week treatment and a 1 to 2-week break was applied twice, with a total radiation dose of 60 Gy, followed by two or more courses of 5-FU and CDDP. In all, 24 patients (42%) achieved a complete response, and the 3-year survival rate was 19%. Major toxicities were leukocytopenia and oesophagitis, and there were two (4%) treatment-related deaths. In contrast, 22 patients with T3 disease survived longer than 35 patients with T4 disease (P=0.001); however, the survival rate in 15 patients with M1 LYM disease did not differ significantly from that in 42 patients without M1 LYM disease (P=0.3545). Our results indicate that definitive chemoradiotherapy is potentially curative for locally advanced oesophageal carcinoma with malignant stricture. The efficacy and survival of patients treated with this regimen are related to the T factor.

Adult↗
PubMed2003

Long-term potentiation and long-term depression in hippocampal CA1 neurons of mice lacking the IP(3) type 1 receptor.

To investigate the role in synaptic plasticity of Ca(2+) released from intracellular Ca(2+) stores, mice lacking the inositol 1,4,5-trisphosphate type 1 receptor were developed and the physiological properties, long-term potentiation, and long-term depression of their hippocampal CA1 neurons were examined. There were no significant differences in basic synaptic functions, such as membrane properties and the input/output relationship, between homozygote mutant and wild-type mice. Enhanced paired-pulse facilitation at interpulse intervals of less than 60 ms and enhanced post-tetanic potentiation were observed in the mutant mice, suggesting that the presynaptic mechanism was altered by the absence of the inositol 1,4,5-trisphosphate type 1 receptor. Long-term potentiation in the field-excitatory postsynaptic potentials induced by tetanus (100 Hz, 1 s) and the excitatory postsynaptic currents induced by paired stimulation in hippocampal CA1 pyramidal neurons under whole-cell clamp conditions were significantly greater in mutant mice than in wild-type mice. Homosynaptic long-term depression of CA1 synaptic responses induced by low-frequency stimulation (1 Hz, 500 pulses) was not significantly different, but heterosynaptic depression of the non-associated pathway induced by tetanus was blocked in the mutant mice. Both long-term potentiation and long-term depression in mutant mice were completely dependent on N-methyl-D-aspartate receptor activity. To rule out the possibility of an effect compensating for the lack of the inositol 1,4,5-trisphosphate type 1 receptor occurring during development, an anti-inositol 1,4,5-trisphosphate type 1 receptor monoclonal antibody that blocks receptor function was diffused into the wild-type cell through a patch pipette, and the effect of acute block of inositol 1,4,5-trisphosphate type 1 receptor on long-term potentiation was examined. Significant enhancement of long-term potentiation was observed compared with after control immunoglobulin G injection, suggesting that developmental redundancy was not responsible for the increase in long-term potentiation amplitude observed in the mutant mouse. The properties of channels that could be involved in long-term potentiation induction were examined using whole-cell recording. N-methyl-D-aspartate currents were significantly larger in mutant mice than in wild-type mice only between holding potentials of -60 and -80 mV. We conclude that inositol 1,4,5-trisphosphate type 1 receptor activity is not essential for the induction of synaptic plasticity in hippocampal CA1 neurons, but appears to negatively regulate long-term potentiation induction by mild modulation of channel activities.

Action Potentials↗
PubMed2003

Effects of n-3 polyunsaturated fatty acids on indomethacin-induced changes in eicosanoid production and blood flow in the gastric mucosa of rats.

We investigated the effects of n-3 polyunsaturated fatty acids (PUFAs) on non-steroidal anti-inflammatory drug (NSAID)-induced changes in microcirculation and eicosanoid production in the gastrointestinal mucosa. We measured gastric mucosal blood flow using laser Doppler flowmetry, assessed the fatty acid composition in the mucosal phospholipids, and quantified the production of prostaglandin E2 (PGE2), leukotriene B4, and leukotriene C4 (LTB4 and C4) from the mucosa with the stimulation of calcium ionophore 20 min after an injection of indomethacin or vehicle in rats fed a diet containing different compositions of alpha-linolenic acid. Four weeks after the initiation of the test diet the arachidonic acid level in gastric mucosal phospholipids was significantly lower in the perilla group than in the other three groups. Conversely, alpha-linolenic acid and eicosapentaenoic acid (EPA) were significantly higher in the perilla group than in the other three groups. The percent of gastric mucosal blood flow in the three groups administered indomethacin were significantly lower than that in the control group injected with vehicle alone. The percent of gastric mucosal blood flow in the perilla group was significantly higher than that in the corn group. LTB4 and LTC4 production from the gastric mucosa in the soybean and corn groups were significantly higher than those in the control group, and the LTC4 production in the perilla group was significantly lower than that in the corn group. There were no significant differences in PGE2 production among the four groups. Our results suggest that alpha-linolenic acid affectively suppressed the indomethacin-induced decreases in gastric mucosal blood flow by increasing EPA and decreasing the levels of arachidonic acid and LTC4 in the gastric mucosa.

Animals↗
PubMed2003

Dendritic cells genetically engineered to express IL-4 exhibit enhanced IL-12p70 production in response to CD40 ligation and accelerate organ allograft rejection.

C57BL/10 (B10; H2(b)) bone marrow-derived myeloid dendritic cells (DC) propagated in GM-CSF + IL-4 were transduced with r adenoviral (Ad) vectors encoding either control neomycin-resistance gene (Ad-Neo) or murine IL-4 (Ad-IL-4) on day 5 of culture following CD11c immunomagnetic bead purification. Both Ad-Neo- and Ad-IL-4-transduced DC displayed upregulated surface MHC class II and costimulatory molecules (CD40, CD80, CD86). Ad-IL-4 DC secreted higher levels of bioactive IL-12p70 after CD40 ligation or LPS stimulation than either Ad-Neo or unmodified DC. Only Ad-IL-4 DC produced IL-12p70 in primary MLR, in which they induced augmented proliferative responses of naïve allogeneic C3H/HeJ (C3H; H2(k)) T-cells. Compared with Ad-Neo DC, Ad-IL-4 DC were also more effective in priming naïve allogeneic recipients to exhibit specifically enhanced anti-donor T-cell proliferative and CTL responses. T-cells primed in vivo 7 days previously with Ad-IL-4 DC displayed enhanced secretion of Th2 (IL-4, IL-10) but also higher Th1 cytokine (IFNgamma) production following ex vivo challenge with donor alloAg. Moreover, pretreatment of vascularized heart graft recipients with i.v. Ad-IL-4 DC, 1 week before transplant, significantly accelerated rejection and antagonized the therapeutic effect of anti-CD40L (CD154) mAb. These data contrast markedly with recently reported inhibitory effects of autologous Ad-IL-4 DC on autoimmune inflammatory disease.

Animals↗
PubMed2003

Urine-based enzyme-linked immunosorbent assay for the detection of Helicobacter pylori antibodies in children.

OBJECTIVE: Recent studies of urine-based enzyme-linked immunosorbent assays (ELISA) for detection of antibody to Helicobacter pylori (H. pylori) have already shown high sensitivity and specificity in adults. The diagnostic accuracy of these assays in children was investigated. METHODS: The results of serum and urine-based ELISAs were compared with those of 13C-urea breath tests (13C-UBT) and/or detection of faecal H. pylori antigen in 68 children. The effect of urine total immunoglobulin G (IgG) levels on the ELISA results for anti-H. pylori antibodies in urine was also examined. RESULTS: The sensitivity, specificity and accuracy of the serum ELISA were 72.7%, 96.3%, and 92.3% respectively, while those of the urine-based ELISA were 92.3%, 76.4%, and 79.4% respectively. The level of urine total IgG in children with false-positive results in the urine-based ELISA, was significantly higher than that in children who showed negative results in both the urine-based ELISA and the 13C-UBT and/or faecal H. pylori antigen tests. Human gamma-globulin affected the urine-based ELISA results at final concentrations of 2.0 mg/dL, 3.0 mg/dL, and 4.0 mg/dL; the anti-H. pylori antibody values were significantly higher than the ELISA values without the addition of human gamma-globulin. CONCLUSION: The findings suggested that the specificity of urine-based ELISA for detection of H. pylori antibodies is low in children, since high urinary levels of total IgG increase the likelihood of false-positive results.

Adolescent↗
PubMed2003

Disposition of a synthetic analogue of lipid A (E5564) in rats.

1. E5564, a lipid A analogue that potently antagonises lipopolysaccharide, is being developed to treat sepsis caused by Gram-negative bacterial infections. The pharmacokinetic profile of E5564 is independent of dose between 0.1 and 1 mg kg(-1). The distribution volume of E5564 is slightly larger than the total plasma volume, and the terminal elimination half-life is about 5 h. 2. Following (14)C-E5564 administration (0.5 mg kg(-1)), radioactivity rapidly accumulates in the liver and spleen. The half-life of E5564 in the liver is 5.1 h, which is similar to that in the plasma. At 48 weeks after dosing, 35.27% of the administered radioactivity was still present in the liver. Cumulative urinary and faecal excretion of radioactivity for up to 48 weeks after administration were 3.86 and 67.17% of the dose, respectively. 3. The results of mass spectroscopy and nuclear magnetic resonance analysis reveal that the main hepatic metabolite is di-dephosphorylated E5564. The half-life of di-dephosphorylated E5564 in the liver is 87.4 days, which is similar to that for the hepatic radioactivity. 4. The results indicate that E5564 is rapidly taken up by the liver, is metabolized via dephosphorylation pathways to form dephosphorylated E5564 and is mainly excreted in the faeces.

Animals↗
PubMed2003

Renal tubular dysfunction in children living in the Aral Sea Region.

BACKGROUND: The Aral Sea region is a natural area seriously polluted by human activities. Recent surveillance revealed the increased prevalence of diverse chronic diseases in children. AIMS: To investigate the function of renal tubules, which are most at risk of damage as a result of heavy metal intoxication, in children of the Aral Sea region. METHODS: A group of 205 children living in Kazalinsk, close to the Aral Sea, and a group of 187 children living in Zhanakorgan, far from the Aral Sea, were examined by means of random urine samples. Both urinary N-acetyl-beta-D-glucosaminidase (NAG; U/mmol Cr) and beta2 microglobulin (BMG; microg/mmol Cr) were calculated for each subject. RESULTS: Mean urinary NAG and BMG were both significantly higher in Kazalinsk than in Zhanakorgan (NAG: 0.77 (0.58) and 0.62 (0.37) U/mmol Cr; BMG: 41.8 (54.8) and 22.5 (20.4) microg/mmol Cr, respectively; mean (SD), p < 0.01). The number of children with abnormal values of NAG (>1.5 U/mmol Cr) was significantly more prevalent in Kazalinsk than in Zhanakorgan (7.9% and 2.6%, respectively, p < 0.05). CONCLUSION: Renal tubular function of children around the Aral Sea region is profoundly impaired. This should be taken into account when considering the health problems of this area.

Acetylglucosaminidase↗
PubMed2002

Hamatometacarpal fracture-dislocation: distinctive three dimensional computed tomographic appearance.

We report here two fully documented cases of hamatometacarpal fracture-dislocation following trauma and treated in our hospital. In our cases, the patients suffered hamate fracture in association with metacarpal dislocation. In the first case, a dorsal oblique fracture of the hamate was associated with a dorsal dislocation of the base of the fourth metacarpal. In the second case, a dorsal oblique fracture of the hamate was not associated with a dorsal dislocation of the base of the fifth metacarpal. This diagnosis should be suspected on initial review of plain radiographs, which must include an oblique view because of diagnostic difficulty for this injury. We recommend three dimensional computed tomography (3D-CT) in any patient presenting with pain after blunt trauma to the hand to prevent in diagnosis. Open reduction and internal fixation of the fracture is indicated and relevant for displaced fracture.

Adult↗
PubMed2002

Recurrent palmar dislocation of the distal radioulnar joint. A case report.

Recurrent palmar dislocation of the distal radioulnar joint is not a common injury. We report one case in a 73-year-old female. This injury was incorrectly diagnosed at the first presentation because there has been no distinct deformity at the wrist and extension-flexion was normal. The need for proper physical examination and accurate radiographic positioning is stressed. Distal diaphysis resection combined with distal radioulnar arthrodesis (modified Sauve-Kapandji procedure) was the preferred method of treatment in an old patient. Two years after the injury, the patient was asymptomatic.

Age Factors↗