Search PubMed⌕ Search

Biomedical subjects

Takashi Yamaguchi

Publications and source records attributed to Takashi Yamaguchi.

12 recordsLinked to original sources
PubMed2005

Multiple organ involvement in eosinophilic polymyositis: an autopsy report.

This report describes autopsy findings of eosinophilic polymyositis in a 29-year-old woman. She complained of muscle pain and tenderness. A serum examination disclosed elevated creatine kinase, and echocardiography showed lowered cardiac function. Electromyography demonstrated myopathic potentials, and the skeletal muscle biopsy revealed degeneration of muscle fibers accompanying marked eosinophilic infiltration. Peripheral eosinophilia was not prominent. A systemic examination excluded possible etiologic factors, such as hypereosinophilic syndrome, collagen vascular diseases, or parasites. The patient died of heart failure after a 4-month clinical course. The autopsy disclosed a set of histological changes indicating tissue injuries, that is, loss of muscle fibers, interstitial fibrosis, and/or infiltrates of lymphocytes not only in the skeletal muscles and heart but also in various visceral organs. Eosinophils were sparsely scattered. These results indicate that the overrun of eosinophils underlying eosinophilic polymyositis, regardless of the presence of hypereosinophilic syndrome or other systemic disorders, could involve wide-ranging visceral organs.

Adult↗
PubMed2005

Air pollution and young children's inhalation exposure to organophosphorus pesticide in an agricultural community in Japan.

Assessment of airborne organophosphorus pesticides in houses of young children (1-6 years old) and childcare facilities was conducted following pesticide applications in an agricultural community in Japan. Trichlorfon and fenitrothion, applied in two separate periods, were frequently detected from outdoor and indoor air. Dichlorvos, the primary degradation product of trichlorfon, was also detected after the application of trichlorfon. Both the outdoors and indoor concentration of applied pesticide were shown to increase with decreasing distance from the pesticide-applied farm. Indoor concentration of these pesticides significantly correlated with outdoor concentration (p=0.001 for trichlorfon and p=0.001 for fenitrothion), indicating infiltration of applied pesticide inside. Ratio of indoor to outdoor concentration (I/O ratio) of fenitrothion was higher for houses with windows open during the application than those with closed windows (median value: 0.74 vs. 0.16, p=0.003). However, a similar trend was not observed for trichlorfon as well as dichlorvos in the first period. Dichlorvos was found to have a higher I/O ratio than trichlorfon during the period, and clear correlation between indoor concentrations of dichlorvos and those of trichlorfon suggested increased decomposition of trichlorfon in the indoor environment. Daily inhalation exposure estimated by using the fixed measurement data and time-activity questionnaire ranged from 0 to 35 ng/kg/day for trichlorfon, from 0 to 26 ng/kg/day for dichlorvos, and from 0 to 44 ng/kg/day for fenitrothion. Median inhalation exposure from indoor air accounted for 74%, 86.3%, and 45% of the daily inhalation exposure, respectively. For kindergarteners or nursery school children, inhalation exposure at childcare facilities was comparable with or more than that at home, indicating that pollution level at childcare facilities had potential of high impact on children's exposure. Estimated daily inhalation exposures were inversely correlated to the proximity of their activity location to the pesticide-applied farm.

Air Pollution, Indoor↗
PubMed2005

Cytokeratin 20-positive large cell neuroendocrine carcinoma of the colon.

Herein is presented a case of cytokeratin (CK) 20-positive large cell neuroendocrine carcinoma of the colon, in which the tumor was clinically at stage IV and located in the ascending colon. Pathological examination of the resected tumor revealed nested and solid proliferation of large undifferentiated cells with vesicular nucleus and prominent nucleoli. No areas showed differentiation toward adenocarcinoma or squamous cell carcinoma. Tumor cells were immunohistochemically positive for chromogranin A, synaptophysin, CD 56 (focal), and bore electron-dense granules. With these features, the tumor was diagnosed as a large cell neuroendocrine carcinoma of the colon. Liver metastasis and local recurrence progressed, and the patient died of the primary disease 7 months after operation. The autopsy confirmed this diagnosis without detectable tumors in the lungs. Interestingly, more than half of the tumor cells were positive for CK 20, while CK 7 was not expressed. Most neuroendocrine carcinomas do not express CK 20, with the exception of Merkel cell carcinomas, and most colorectal adenocarcinomas express CK 20. To the best of the authors' knowledge, the present case is the first CK 20-positive, CK 7-negative colorectal neuroendocrine carcinoma to be described, suggesting a link between colorectal neuroendocrine carcinoma and conventional adenocarcinoma.

Aged↗
PubMed2004

Natronolimnobius baerhuensis gen. nov., sp. nov. and Natronolimnobius innermongolicus sp. nov., novel haloalkaliphilic archaea isolated from soda lakes in Inner Mongolia, China.

Three novel isolates of haloalkaliphilic archaea, strains IHC-005T, IHC-010, and N-1311T, from soda lakes in Inner Mongolia, China, were characterized to elucidate their taxonomic positions. The three strains were aerobic, Gram-negative chemoorganotrophs growing optimally at 37-45 degrees C, pH 9.0-9.5, and 15-20% NaCl. Cells of strains IHC-005T/IHC-010 were motile rods, while those of strain N-1311T were non-motile pleomorphic flats or cocci. The three strains contained diphytanyl and phytanyl-sesterterpanyl diether derivatives of phosphatidylglycerol and phosphatidylglycerophosphate methyl ester. No glycolipids were detected. On phylogenetic analysis of 16S rRNA gene sequences, they formed an independent cluster in the Natro group of the family Halobacteriaceae. Comparison of their morphological, physiological, and biochemical properties, DNA G + C content and 16S rRNA gene sequences, and DNA-DNA hybridization study support the view that strains IHC-005T/IHC-010 and strain N-1311T represent separate species. Therefore, we propose Natronolimnobius baerhuensis gen. nov., sp. nov. for strains IHC-005T (=CGMCC 1.3597T =JCM 12253T)/IHC-010 (=CGMCC 1.3598 = JCM 12254) and Natronolimnobius innermongolicus sp. nov. for N-1311T (=CGMCC 1.2124T =JCM 12255T).

Archaea↗
PubMed2004

The central pattern generator for forelimb locomotion in the cat.

This chapter addresses the neuronal organization of the central pattern generator (CPG) for forelimb locomotion in the cat. The focus is on fictive locomotion, as induced by repetitive stimulation of the cervical lateral funiculus (CLF) in the decerebrate preparation. The stimulus time-locked responses of cervical motoneurons (MNs) that follow each current pulse of such repetitive stimulation include disynaptic EPSPs, trisynaptic EPSPs and IPSPs, and polysynaptic PSPs. Their amplitudes are all phase-related to selected aspects of the locomotor rhythm, as determined by the pattern of discharge in nerves to selected muscles. Correlation analysis reveals rhythmic modulation between the responses of extensor and flexor MNs, thereby suggesting mutual interactions between pathways mediating the CLF effects on MNs. It is argued that the shortest CLF pathway to MNs via the CPG is disynaptic: i.e., with only a single intercalated interneuron (IN) between the descending command axons and the MNs. A second proposal is that such intercalated INs contribute to interacting, reverberating IN circuits (i.e., the CPG) through mutual excitation.

Animals↗
PubMed2004

Response patterns of vestibulospinal neurons to lumbar rotation in decerebrate rats.

In vestibulospinal neurons projecting to the lumbar enlargement, activities were modulated in response to alternate tilts of the caudal body around the vertebral axis. Three types of neurons were found: Type I (37.8%) showed faster firing during the ipsilateral side-down tilt; type II (51.1%) showed the reverse pattern; type III were unaffected. Types I and II may be important in the tonic lumbar reflex.

Animals↗
PubMed2002

Controlled kinetics of non-enzymatic chemiluminescence reactions for simple imaging of DNA and protein.

A robust and sensitive non-enzymatic chemiluminescence (CL) imaging method is presented. In the method a fast-emitting CL reaction is tuned to furnish a slower-emitting reaction suitable for simple CL imaging. Typically, non-enzymatic CL reactions between luminol or fluorescein and oxygen species generated by KCN as catalyst, were rather fast and unsuitable for CL imaging; the speed of the reactions could, however, be reduced substantially by changing KCN for CH(3)CN or benzonitrile. Light emission from the tuned CL reaction was intense and long-lived, and even with a simple arrangement high sensitivity could be achieved. The maximum CL peak was reached after approximately 1.5 min in the presence of 25% acetonitrile, and as little as 16 fmol commercial isoluminol-labeled streptavidin was detected and visualized on either microplate or membrane. The approach was further illustrated by imaging of DNA on a membrane and of antibody on a microplate by use of biotin-streptavidin chemistry. Overall, this simple, economical, and sensitive CL imaging system is expected to be very useful in biochemical analysis, and greatly complements currently used enzyme-based CL imaging methods, especially in routine applications.

DNA↗
PubMed2002

Transgenic expression of FGF8 and FGF10 induces transdifferentiation of pancreatic islet cells into hepatocytes and exocrine cells.

FGF signaling is essential for normal development of pancreatic islets. To examine the effects of overexpressed FGF8 and FGF10 on pancreatic development, we generated FGF8- and FGF10-transgenic mice (Tg mice) under the control of the glucagon promoter. In FGF8-Tg mice, hepatocyte-like cells were observed in the periphery of pancreatic islets, but areas of alpha and beta cells did not decrease, whereas in FGF10-Tg mice, pancreatic ductal and acinar cells were found in islets, concomitantly with disturbed beta-cell differentiation. These results suggest that FGF8 and FGF10 play important roles in development of hepatocytes and exocrine cells, respectively, and explain the absence of FGF8 expression in normal islets and pancreatic hypoplasia in FGF10-deficient mice.

Albumins↗
PubMed2002

Hepatic dysfunction after left ventricular mechanical assist in patients with end-stage heart failure: role of inflammatory response and hepatic microcirculation.

BACKGROUND: In the condition of preexisting vital organ failure induced by heart failure, hepatic failure often progresses despite establishment of adequate hemodynamic support through a left ventricular assist device (LVAD) and results in a high mortality rate. We hypothesized that inflammatory responses, including those induced by infection and their influence on organ perfusion, may contribute to the pathogenesis of this progressive hepatic failure and subsequent multiple organ failure as reported in the current investigation on multiple organ failure after major surgery or trauma. METHODS: Hepatic function and its relation to inflammatory response and hepatic microcirculation were evaluated in 16 consecutive patients who received an implantation of LVAD for end-stage cardiomyopathy, between 1992 and 2000. Patients were divided into two groups: 5 patients who died from multiple organ failure after severe hepatic failure (group 1) and 11 patients who did not develop severe hepatic failure (group 2). Serum levels of CRP, interleukin (IL)-6, IL-8, and serum hyaluronan, a known indicator of hepatic sinusoidal function, were measured pre- and postoperatively in both groups. RESULTS: Serum ALT and AST levels during LVAD support were similar in the two groups. Serum total bilirubin (T-Bil), CRP, IL-6, and IL-8 levels before and during the first 20 days of LVAD support were significantly higher in group 1 than those in group 2 (p < 0.01 to 0.05). Serum hyaluronan levels in both groups were significantly correlated with T-Bil levels (r = 0.60, p < 0.05 in group 1; r = 0.68, p < 0.0001 in group 2). Histopathological examination by transvenous liver biopsy in a group 1 patient showed hepatic sinusoidal damage as well as cholestasis and fibrosis. CONCLUSIONS: Patients with hyperbilirubinemia and inflammatory reactions before LVAD support showed increased hyperbilirubinemia and inflammatory cytokine and hyarulonan levels despite adequate hemodynamics achieved under LVAD support. These results suggest that inflammatory response contributes to subsequent aggravation of hepatic dysfunction, probably with underlying and continuing derangement in hepatic sinusoidal microcirculation even under systemic circulatory support.

Adult↗
PubMed2002

[Usefulness of postmortem dental panoramic X-ray photographs taken using a portable radiography apparatus for dental identification].

Fourteen unidentified human corpses were subjected to personal identification between 1999 and 2001. They included 5 drowning victims, three extensively burnt bodies, three skeletonized bodies, two highly putrefied bodies, and a body that had been run over by a train. Antemortem dental records were available in 12 cases, and all were positively identified. For 10 of these cases, antemortem panoramic X-ray photographs were obtained. For postmortem examination, panoramic X-ray photographs were taken using a portable dental panoramic radiography apparatus, LPX7007 (ASAHI ROENTGEN, Japan), during autopsy. Comparison of the ante- and postmortem panoramic X-ray photographs gave accurate and useful information not only about dental treatment but also the anatomical features surrounding the upper and lower jaws. This method is not time-consuming and also has the advantage of allowing dental treatment to be examined extraorally in cases where it is difficult to open the mouth of the corpse.

Forensic Anthropology↗
PubMed2002

[Not Available].

Explore the source record for details and available documents.

Journal Article↗