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Biomedical subjects

K Kaneko

Publications and source records attributed to K Kaneko.

At least 145 records · Page 8Linked to original sources
PubMed2000

Growth patterns of superficially elevated neoplasia in the large intestine.

BACKGROUND: The growth pattern and malignant potential of superficially elevated neoplastic lesions remain controversial. A flat adenoma is classified as a superficially elevated neoplasm that characteristically demonstrates high-grade dysplasia despite its small size. In contrast, a nodule-aggregating (NA) tumor, which consists of multiple small aggregated nodules, can also be classified as superficially elevated neoplasia. METHODS: In this prospective study, 2720 consecutive patients undergoing total colonoscopy were examined for superficially for elevated lesions. Clinicopathologic characteristics, Ki-ras mutational status, and overexpression of p53 protein were compared in 25 NA tumors and 55 flat adenomas without a central depression (flat tumor). RESULTS: All flat tumors had a tubular pattern, whereas 21 of 25 NA tumors showed a villotubular or tubulovillous pattern. Ki-ras mutation was observed in 44% of NA tumors but in none of the flat tumors. Overexpression of p53 protein was found in 12% of NA tumors and 7% of flat tumors. CONCLUSIONS: NA tumors and flat tumors have different clinicopathologic and genetic characteristics, although both types of tumor are classified as superficially elevated lesions.

Adenocarcinoma↗
PubMed2000

Posterolateral dislocation of the ankle without fracture.

We report an unusual case of open posterolateral dislocation of the ankle without fracture following a motor vehicle accident. Most of previously reported cases are posteromedial dislocation. The anterolateral, posterolateral, and purely superior dislocations of the talus make up smaller percentage. The mechanism of this injury appears to be forced eversion of the foot when it is maximally plantar flexed and axially loaded. Our case was treated by manual reduction and percutaneous fixation and anatomical repair of the disrupted deltoid ligament at the time of initial débridement, also achieved good long-term functional and radiographic results.

Accidents, Traffic↗
PubMed2000

Group-II phospholipase A(2) enhances oxidized low density lipoprotein-induced macrophage growth through enhancement of GM-CSF release.

Inflammatory process plays an important role in the development and progression of atherosclerotic lesions. Recently, group-II phospholipase A(2) (PLA(2)), an inflammatory mediator, was reported to exist in human atherosclerotic lesions and to enhance the development of murine atherosclerotic lesions. Oxidized low density lipoprotein (Ox-LDL) stimulates the growth of several types of macrophages in vitro. Since proliferation of macrophages occurs in atherosclerotic lesions, it is possible to assume that the Ox-LDL-induced macrophage proliferation might be involved in the progression of atherosclerosis. In this study, the role of group-II PLA(2) in the Ox-LDL-induced macrophage growth was investigated using thioglycollate-elicited mouse peritoneal macrophages. Thioglycollate-elicited macrophages significantly expressed group-II PLA(2) and released it into the culture medium. The Ox-LDL-induced thymidine incorporation into thioglycollate-elicited macrophages was three times higher than that into resident macrophages, whereas under the same conditions, granulocyte/macrophage colony-stimulating factor (GM-CSF) equally induced thymidine incorporation into both types of macrophages. Moreover, the Ox-LDL-induced GM-CSF release from thioglycollate-elicited macrophages was significantly higher than that from resident macrophages. In addition, the Ox-LDL-induced thymidine incorporation into macrophages obtained from human group-II PLA(2) transgenic mice and the GM-CSF release from these cells were significantly higher than those from their negative littermates, and the Ox-LDL-induced thymidine incorporation into human group-II PLA(2) transgenic macrophages was significantly inhibited by a polyclonal anti-human group-II PLA(2) antibody. These results suggest that the expression of group-II PLA(2) in thioglycollate-elicited macrophages may play an enhancing role in the Ox-LDL-induced macrophage growth through the enhancement of the GM-CSF release.

Animals↗
PubMed2000

Gemfibrozil metabolite inhibits in vitro low-density lipoprotein (LDL) oxidation and diminishes cytotoxicity induced by oxidized LDL.

We hypothesized that M1, a metabolite of gemfibrozil, may have antioxidant properties because of its hydroxylated phenol ring, 5-(4-hydroxy-2,5-dimethyl-phenoxy)-2,2-dimethyl pentanoic acid. The susceptibility of low-density lipoprotein (LDL) to oxidative modification was investigated by a method using 2,2-azobis(4-methoxy-2,4-dimethylvaleronitrile [MeO-AMVN]) or Cu2+ as previously reported. Conjugated dienes (CDs), lipid hydroperoxide (LPO), and thiobarbituric acid-reactive substances (TBARS) were measured to evaluate the degree of LDL oxidation. Oxidized LDL (OxLDL), which is used for cytotoxicity studies, was prepared by the dialysis method using Cu2+ as the oxidation inducer. Cytotoxicity induced by OxLDL was studied in J774 macrophages by colorimetric assay using 3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT assay). The oxidative modification of LDL was inhibited by M1 in a dose-dependent manner. The antioxidant effect of M1 on LDL oxidation was diminished by dialysis of the LDL incubated with M1 against phosphate-buffered saline (PBS), suggesting that M1 is hydrophilic rather than lipophilic. M1 diminished the cytotoxicity induced by OxLDL, although it was milder versus probucol. These data suggest that this gemfibrozil metabolite has an antioxidant effect on LDL, and thus M1 may contribute to the antiatherogenic effects of gemfibrozil.

Antioxidants↗
PubMed2000

Bradykinin enhances insulin receptor tyrosine kinase in 32D cells reconstituted with bradykinin and insulin signaling pathways.

We have previously shown that bradykinin potentiated insulin-induced glucose uptake through GLUT4 translocation in canine adipocytes and skeletal muscles. The aim of this study was to determine the molecular mechanism of bradykinin enhancement of the insulin signal. For this purpose, 32D cells, which express a limited number of insulin receptors and lack endogenous bradykinin B2 receptor (BK2R) or insulin receptor substrate (IRS)-1 were transfected with BK2R cDNA and/or insulin receptor cDNA and/or IRS-1 cDNA, and analyzed. In 32D cells that expressed BK2R and insulin receptor (32D-BKR/IR), bradykinin alone had no effect on the phosphorylation of the insulin receptor, but it enhanced insulin-stimulated tyrosine phosphorylation of the insulin receptor. In 32D cells that expressed BK2R, insulin receptor and IRS-1 (32D-BKR/IR/IRS1), bradykinin also enhanced insulin-stimulated tyrosine phosphorylation of the insulin receptor and IRS-1. An increase in insulin-stimulated phosphorylation of IRS-1 by treatment with bradykinin in 32D-BKR/IR/IRS1 cell was associated with increased binding of 85 kD subunit of phosphatidylinositol 3 (PI 3)-kinase and increased IRS-1 associated PI 3-kinase activity. These effects of bradykinin were not observed in 32D cells which lack the expression of BK2R (32D-IR/IRS1) or insulin receptor (32D-BKR/IRS1). Furthermore, tyrosine phosphatase activity against insulin receptor beta-subunit in plasma membrane fraction of 32D-BKR/IR cells was significantly reduced by bradykinin, suggesting that the effect of bradykinin was in part mediated by inhibition of protein tyrosine phosphatase(s). Our results clearly demonstrated that bradykinin enhanced insulin-stimulated tyrosine kinase activity of the insulin receptor and downstream insulin signal cascade through the BK2R mediated signal pathway.

Animals↗
PubMed2000

Natural language from function dynamics.

A new approach to syntax and semantics of language is presented as a form of function dynamics, which is studied both analytically and numerically. The iteration of the function dynamics leads to articulation and formation of rules, which depend on each other. A hierarchy of meta-rules as rules of rules also emerges through the iteration when the initial function is suitably embedded. Iteration of a model with dialogue between two function dynamics is shown to generate a higher level structure.

Humans↗
PubMed2000

Self-organized hierarchical structure in a plastic network of chaotic units.

Formation of a layered structure is studied in a globally coupled map of chaotic units with a plastic coupling strength that changes depending on the states of units globally and an external input. In the parameter region characterized by weakly chaotic and desynchronized dynamics, units spontaneously form a hierarchical structure due to the influence of the input. This hierarchical structure is not fixed in time, and is successively reorganized. It is found that the distribution of lifetimes of the structure obeys a power law. The possible relevance of the present result to information processing in the brain is briefly discussed.

Animals↗
PubMed2000

Bilateral transcapholunate dislocation.

An uncommon case has been reported of bilateral transscaphoid-perilunate dislocation fracture following trauma. A 35-year-old male with bilateral transscapholunate dislocation was treated by closed reduction and internal fixation. The case was examined in detail, and compared to the findings in the literature; observations regarding fracture prognosis were also made. Two years post-surgery, the patient remained asymptomatic.

Accidental Falls↗
PubMed2000

Xanthogranulomatous pyelonephritis in childhood: a rare but important clinical entity.

PURPOSE: Xanthogranulomatous pyelonephritis (XGPN) is extremely rare in children. The authors review their experience of this condition. METHODS: Medical records were investigated to conduct a retrospective study of 4 patients with XGPN (3 boys, 1 girl; age range, 2 months to 7 years) at the authors' institute over the past 14 years. RESULTS: Three of the 4 patients presented with fever of unknown origin and 1 with general fatigue. An abdominal mass was palpable in two cases at initial presentation. Although all patients had pyuria or hematuria, preoperative urine culture was positive in only 2 cases. Preoperative radiologic studies showed that 1 kidney was affected completely in 2 cases and affected partially in 2 cases. Preoperatively, the provisional diagnosis was XGPN in 3 cases, and Wilms' tumor in 1 case. Total nephrectomy was performed in 3 cases and enucleation in 1 case. XGPN was confirmed in all cases by histopathologic studies, but the underlying disease could be identified only in 1 case (cystinuria). All patients did well postoperatively and have had no further health problems over a mean follow-up period of 4.8 years. CONCLUSIONS: XGPN should be considered when there is a history of recurrent or therapy-resistant pyelonephritis. Preoperative radiologic investigation is paramount for diagnosis, and nephrectomy is the treatment of choice, although partial resection or enucleation are adequate for partially affected kidneys.

Child↗
PubMed2000

The diagnostic value of intraoperative measurement of choline acetyltransferase activity during brachial plexus surgery.

We used the measurement of choline acetyltransferase (CAT) activity to distinguish between preganglionic and postganglionic injuries of the spinal roots during brachial plexus surgery. This study includes ten spinal roots in six patients with traumatic brachial plexus injuries. The results of CAT activity were compared with myelographic findings, the operative findings and the intraoperative evoked spinal cord potentials. The results of CAT activity and the operative findings were consistent in all roots. Whereas CAT activity in fascicles in preganglionic injured roots was below 500 cpm, it was above 2000 cpm in postganglionic injured roots. This study shows that intraoperative measurement of CAT activity can provide useful information on the site and severity of brachial plexus injuries and the assessment of the motor function status of the injured spinal root, both directly and quantitatively.

Adult↗
PubMed2000

The pattern of CPP32/caspase-3 expression reflects the biological behavior of the human pancreatic duct cell tumors.

Caspase-3/CPP32, a member of the Ced-3-family of cysteine proteases, is an important mediator of programmed cell death (apoptosis). Intraductal papillary-mucinous tumor of the pancreas (IPMT) is a unique tumor that grows intraductally with rare stromal invasion. However, it is not possible to distinguish noninvasive from invasive IPMT preoperatively. To examine whether caspase-3 expression reflects the biological behavior of pancreatic tumors, we investigated this enzyme expression by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry in 22 pancreatic duct cell carcinomas (PDC) and 13 IPMT cases. Caspase-3 mRNA was overexpressed in PDC and IPMT with carcinoma when compared with normal pancreatic tissue or IPMT with adenoma. The immunoreactivity of this enzyme was predominantly found in the cytoplasm of invasive tumors (PDC and invasive IPMT). There was a significant correlation between the cytoplasmic staining and malignant grade of the tumors. In contrast, the nuclear expression of this enzyme was significantly higher in noninvasive than in invasive tumors (p = 0.0015). Cytoplasmic expression of caspase-3 may be related to the invasiveness of pancreatic tumors. In contrast, nuclear expression of this enzyme may reflect the benign biological behavior of IPMT.

Apoptosis↗
PubMed2000

Perinatal risk factors related to neurologic outcomes of term newborns with asphyxia at birth: a prospective study.

OBJECTIVES: The incidence of poor neurologic outcomes was studied in term newborns who had suffered severe asphyxia at birth. METHODS: Subjects were 152 newborns admitted to the NICU with a low Apgar score at 1 or 5 minutes. A 1-year prospective follow-up of neurological outcomes was carried out by a questionnaire survey concluded between April 1, 1996 and March 31, 1998. RESULTS: 1) The incidence of a poor neurologic outcome, including 15 neurologic sequelae and 6 deaths, was 13.8% among the subjects. 2) The risk of a poor outcome was increased by 13-fold in neonates with adverse neurological signs and 31-fold in those with hypoxic ischemic encephalopathy. CONCLUSION: The incidence of poor neurologic outcome was very high among term infants with low Apgar scores. These infants were 10 times to 20 times more likely to die, or to survive with permanent disabilities, than were infants without low Apgar scores.

Adult↗
PubMed2000

[Basic study on anti-bacterial urethral catheter. I. Development of a new anti-bacterial coating material for silicon catheters].

In order to develop a new anti-bacterial urethral catheter, we studied anti-bacterial and anti-adherent coating material suitable for silicon catheters. Several aspects of various silver compounds were examined, including anti-bacterial activity, chemical property and toxicity. Among silver citrate, silver phosphate and silver oxide, which were found to have excellent anti-bacterial activities, silver citrate was regarded as the material of choice for anti-bacterial coating in terms of durable activity and biological safety. It was also found that several surfactants inhibited bacterial adherence to the surface of silicon catheters. Among them soybean lecithin exhibited excellent anti-adherent activity in a dose dependent manner. Finally, a mixture of silver citrate, soybean lecithin and liquid silicon at the ratio of 2:2:8 was regarded as an ideal anti-bacterial coating material for silicon catheters.

Animals↗
PubMed2000

[Basic study on anti-bacterial urethral catheter. II. Potency of a new anti-bacterial catheter and its durability in experimental models].

The potency and effectiveness of an anti-bacterial catheter coated with a mixture of silver citrate, soybean lecithin and liquid silicon at the ratio of 2:2:8 were compared with those of commercially available anti-bacterial and conventional urethral catheters. This new anti-bacterial catheter showed a strong activity and excellent durability in ordinary in vitro experimental studies. In the present series we have developed new in vitro experimental models for the evaluation of anti-bacterial catheters in inhibiting bacterial ascent via intraluminal or extraluminal route. The characteristic features of the silver citrate/lecithin catheter, namely strong activity and excellent durability, were confirmed using these new models that mimic urinary catheter-associated clinical infections.

Catheterization↗