Biomedical subjects

Satoshi Takeuchi

Publications and source records attributed to Satoshi Takeuchi.

10 recordsLinked to original sources

PubMed2004

Time-wavelength two-dimensional femtosecond fluorescence imaging.

We report a new femtosecond time-resolved fluorescence spectrometer that enables us to observe fluorescence intensity as a time-wavelength two-dimensional image in a single measurement. This method utilizes a time-to-space conversion technique and fluorescence sum-frequency mixing with a femtosecond gate pulse. It provides a fluorescence image covering temporal and spectral spans of approximately 2 ps and approximately 60 nm, respectively. Calibration of the time and intensity axes of the image is made by use of a long-lived dye fluorescence. The two-dimensional fluorescence image of beta-carotene obtained demonstrates the high potential of this method for quantitative studies of ultrafast excited-state dynamics.

Journal Article↗

PubMed2003

Absorption of short wavelengths of endoillumination in indocyanine green solution: implications for internal limiting membrane removal.

PURPOSE: To measure the absorption coefficients of short wavelengths, irradiated by a light source used for vitreous surgery, in indocyanine green (ICG) solution and balanced salt solution (BSS), and to determine the implications of these absorption coefficients on retinal phototoxicity caused by ICG-assisted internal limiting membrane removal. METHODS: The absorption coefficients of short wavelengths irradiated by a commercially available light source used for vitreous surgery were measured in ICG solution and BSS using a dual-beam spectroradiometer. RESULTS: The absorption coefficient of wavelengths irradiated by the endoillumination light source in ICG solution was almost the same as that obtained in BSS. The absorbance coefficients of the ICG solutions were 0.18 cm(-1) at 400 nm and 0.03 cm(-1) at 450 nm. In BSS, the absorption coefficients were 0.17 cm(-1) at 400 nm and 0.015 cm(-1) at 450 nm. No significant difference in absorbance was seen between 400 nm and 450 nm ( P>0.05). CONCLUSIONS: The absorption of wavelengths is not greater in ICG solution than in BSS. ICG solution during intravitreal use probably does not enhance retinal photochemical injury during ICG-assisted internal limiting membrane removal.

Absorption↗

PubMed2003

Genomic convergence: identifying candidate genes for Parkinson's disease by combining serial analysis of gene expression and genetic linkage.

We present a multifactorial, multistep approach called genomic convergence that combines gene expression with genomic linkage analysis to identify and prioritize candidate susceptibility genes for Parkinson's disease (PD). To initiate this process, we used serial analysis of gene expression (SAGE) to identify genes expressed in two normal substantia nigras (SN) and adjacent midbrain tissue. This identified over 3700 transcripts, including the three most abundant SAGE tags, which did not correspond to any known genes or ESTs. We developed high-throughput bioinformatics methods to map the genes corresponding to these tags and identified 402 SN genes that lay within five large genomic linkage regions, previously identified in 174 multiplex PD families. These genes represent excellent candidates for PD susceptibility alleles and further genomic convergence and analyses.

Alleles↗

PubMed2003

Different effects of phencyclidine and methamphetamine on firing activity of medial prefrontal cortex neurons in freely moving rats.

The purpose of this study was to compare the effects of systemically administered MAP with those of phencyclidine (PCP), both of which induced comparable locomotor activity, on firing activity of medial prefrontal cortex (mPFC) neurons in freely moving rats. The results show that, unlike PCP, acutely administered MAP produced little changes in firing activity of mPFC neurons.

Animals↗

PubMed2003

Indications for surgical repair of funnel chest based on indices of chest wall deformity and psychological state.

PURPOSE: We examined the surgical indications for funnel chest, taking psychological factors into consideration. METHODS: We assessed 36 young people with funnel chest who were seen as outpatients, including 31 boys and 5 girls aged from 1 to 22 years old. Respondents were asked whether they suffered psychological distress, and if they wanted surgery. The severity of the deformity was evaluated using the Vertebral Index (VI) and the Frontosagittal Index (FSI) calculated from chest roentgenograms. RESULTS: The VI in 11 patients without distress (23.7 +/- 4.1) was lower than that in 25 patients with distress (32.8 +/- 8.2), and the FSI in the patients without distress (33.5 +/- 5.3) was higher than that in the patients with distress (23.6 +/- 8.6). The VI in 19 patients who did not want surgery (26.9 +/- 7.9) was lower than that in 17 patients who did (33.5 +/- 7.5), and the FSI in the patients who did not want surgery (30.4 +/- 8.1) was higher than that in the patients who did (22.4 +/- 8.1). The distressed patients suffered many psychological problems, such as being the object of bullying. CONCLUSION: The severity of the deformity affected the patient's psychological state. We consider that a VI >28 or an FSI <28 are indications for surgery, based on the mean VI + SD and the mean FSI-SD of patients not suffering distress.

Adolescent↗

PubMed2003

Paradoxically abundant expression of Bcl-2 and adrenomedullin in invasive cervical squamous carcinoma.

BACKGROUND: The purpose of this study was to identify the role of Bcl-2 protein and adrenomedullin (AM) expression in relation to apoptosis in the neoplastic changes of squamous epithelium of the uterine cervix. METHODS: Apoptosis in sections of normal cervical epithelium, cervical intraepithelial neoplasia (CIN), and invasive squamous cell carcinoma was determined by terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick-end labeling (TUNEL) assay. Bcl-2 protein and AM expression were analyzed using the avidin-biotin immunoperoxidase method. RESULTS: On the basis of the TUNEL assay, the apoptosis positive rate of the nuclei in early invasive squamous carcinoma and in bulky invasive squamous carcinoma was significantly higher than that in normal cervical epithelium, but no such increase in the apoptosis-positive rate was noted in the nuclei in CIN. Immunohistochemical staining revealed that Bcl-2 protein and AM were immunolocalized in the cytoplasm of invasive squamous carcinoma cells, but not in either CIN lesions or normal cervical epithelium. Bcl-2 protein expression was more prominent in bulky invasive squamous carcinoma cells than in early invasive squamous carcinoma cells. AM expression was also more abundant in bulky invasive squamous carcinoma compared with that in early invasive squamous carcinoma. CONCLUSION: The present results suggest that the expression of Bcl-2 protein and AM in invasive squamous carcinoma may play crucial roles in selecting carcinoma cells resistant to apoptosis and in promoting malignant progression.

Adrenomedullin↗

PubMed2002

Relativistic E x B acceleration.

The relativistic motion of charged particles is analyzed theoretically in electric and magnetic fields that are constant, uniform, and mutually perpendicular. In the relativistic regime where the magnitude of the electric field E is equal to or greater than that of the magnetic field B, i.e., |E| > or =|B|, the particle is effectively accelerated and gains energy indefinitely. This is quite different from the E x B drift motion in the nonrelativistic regime.

Journal Article↗

PubMed2002

Procedural memory in schizophrenia assessed using a mirror reading task.

The preservation of procedural memory in individuals with schizophrenia has been confirmed by methods such as the Tower of Hanoi, pursuit rotor and mirror reading tests. However, the cognitive procedural memory of Japanese subjects with schizophrenia has never been assessed using mirror reading. To better determine the characteristics of cognitive procedural memory in schizophrenia, a Japanese version of the mirror reading task, consisting of cards with words written in Japanese katakana characters in mirror image, was administered to 18 Japanese patients with schizophrenia and 21 normal controls. The results indicated that the patients indeed learned the skill despite exhibiting lower overall performances in reading time than the controls, their scores displaying correlation with the severity of schizophrenic negative symptoms. This suggests that procedural memory for this task is retained in individuals with schizophrenia. It is important for them to use their preserved procedural memory for efficient rehabilitative efforts.

Adult↗

PubMed2002

Chest wall resection in general thoracic surgery.

To clarify the incidence, indications, and efficacy of chest wall resection, a comprehensive review is needed. Chest wall resection was performed in 23 of 162 operations for thoracic disease over a nine-year period. Eight surgeries requiring chest wall resection for benign disease (8/79) were classified as fenestration or thoracoplasty for empyema, or resection of a benign neoplasm. Fifteen patients who underwent chest wall resections for malignant disease (15/83) were classified as contiguous extension of neoplasms of neighboring organs, primary tumor, or local recurrence. The most common procedure in the malignant disease group was resection for contiguous spread of primary lung cancer (n = 7). The survival rate was 50% at 4 years. There were no serious postoperative complications. In some malignant diseases, complete local control with such a procedure may even lead to a long-term survival. This is a safe and an effective procedure for a variety of diseases.

Adolescent↗

PubMed1998

Production of sound waves by bacterial cells and the response of bacterial cells to sound.

Bacterial cells enhance the proliferation of neighboring cells under stress conditions by emitting a physical signal. Continuous single sine sound waves produced by a speaker at frequencies of 6-10, 18-22, and 28-38 kHz promoted colony formation by Bacillus carboniphilus under non-permissive stress conditions of high KCl concentration and high temperature. Furthermore, sound waves emitted from cells of Bacillus subtilis at frequencies between 8 and 43 kHz with broad peaks at approximately 8.5, 19, 29, and 37 kHz were detected using a sensitive microphone system. The similarity between the frequency of the sound produced by B. subtilis and the frequencies that induced a response in B. carboniphilus and the previously observed growth-promoting effect of B. subtilis cells upon B. carboniphilus through iron barriers, suggest that the detected sound waves function as a growth-regulatory signal between cells.

Journal Article↗