Biomedical subjects

Atsushi Murakami

Publications and source records attributed to Atsushi Murakami.

7 recordsLinked to original sources

PubMed2006

[Diagnosis of early stage of breast cancer by mammography].

The incidence of small breast carcinoma especially of non-palpable lesion is increasing after introduction of mammography screening. The tumor of which diameter is less than 2 cm, non invasive carcinoma, and Paget's disease are included in early stage of breast cancer. This article introduces the rate of early stage breast cancer in the mammography screening and the feature of these mammographic findings. Furthermore, we are going to reevaluate mammographical findings, occurrence of invasion, and evaluation the size of the lesion by mammography which are thought to be important for the diagnosis of early stage of breast cancer.

Breast Neoplasms↗

PubMed2006

[Age distribution of transepithelial water loss in human nasal mucosa].

BACKGROUND: Dry nose is a common complaint in the elderly. Age distribution of transepithelial water loss of human nasal mucosa (TEWL) value was evaluated in this study. METHODS: Eighty-eight volunteers (50 men and 30 women) ranging from 10 to 75 years old were recruited for this study. Measurement of TEWL was performed on the inferior nasal turbinate. TEWL was measured with an evaporation meter applying Fick's law (Tewameter TM 300; Courage and Khazaka, Cologne, Germany). RESULTS: TEWL value tends to increase in order of age, indicating that the barrier function of epithelium may decline with age. CONCLUSION: The measurement of transepithelial water loss should be contributed to assess the efficiency of nasal mucosal barrier disorders in the elderly.

Adolescent↗

PubMed2005

Development of a microchip-based bioassay system using cultured cells.

We developed a novel bioassay system using a glass microchip and cultured cells. A microchamber for cell culture and microchannels for reactions and detection were fabricated on a Pyrex glass substrate by photolithography and wet etching techniques. Cell culture, chemical and enzymatic reactions, and detection were integrated into the microchip. To keep different temperatures locally in three areas of the microchip, we designed and fabricated a temperature control device. Nitric oxide released from macrophage-like cells stimulated by lipopolysaccharide was successfully monitored with the microchip, the temperature control device, and a thermal lens microscope. The total assay time was reduced from 24 to 4 h, and detection limit of NO was improved from 1 x 10(-6) to 7 x 10(-8) M compared with conventional methods. Moreover, the system could monitor a time course of the release, which is difficult to measure by conventional batch methods. We conclude that this system is promising for a rapid bioassay system with very small consumption of cells.

Animals↗

PubMed2004

Cigarette smoking and risk of type 2 diabetes mellitus among middle-aged and elderly Japanese men and women.

For examination of sex- and age-specific relations between smoking and risk of type 2 diabetes mellitus, 39,528 nondiabetic men and 88,613 nondiabetic women aged 40-79 years who underwent health checkups in Ibaraki-ken, Japan, in 1993 were followed through 2002. Risk ratios for diabetes according to smoking habits were calculated using a Cox proportional hazards model. Compared with never smokers, the risk ratio for diabetes among current smokers, after adjustment for age, systolic blood pressure, antihypertensive mediation use, alcohol intake, parental history of diabetes, body mass index, fasting status, blood glucose concentration, total and high density lipoprotein cholesterol levels, and log-transformed triglyceride level, was 1.27 (95% confidence interval (CI): 1.16, 1.38) in men and 1.39 (95% CI: 1.20, 1.61) in women. The excess risk was more pronounced among men with a parental history of diabetes than among men without one. The excess risk among current smokers was observed in both age subgroups (40-59 and 60-79 years). Respective multivariate risk ratios for the age subgroups were 1.37 (95% CI: 1.18, 1.60) and 1.20 (95% CI: 1.08, 1.34) in men and 1.45 (95% CI: 1.18, 1.79) and 1.34 (95% CI: 1.09, 1.66) in women. Smoking was independently associated with increased risk of type 2 diabetes among both middle-aged and elderly men and women.

Adult↗

PubMed2003

First synthesis of 2',3'-epimino-carbocyclic nucleosides.

The preparation of 2',3'-epimino-carbocyclic analogues of adenosine is reported. The reaction of p-tosyl azide with N-substituted 2-azabicyclo[2.2.1]hept-5-en-3-one (ABH) (1a) provided aziridine-fused ABH (2), which was converted to 2',3'-epimino-carbocyclic nucleosides (11).

Adenosine↗

PubMed2003

Correlation between femoral neck version and strain on the femur after insertion of femoral prosthesis.

Stress analysis on the femur after insertion of a femoral prosthesis with a modular interchangeable neck with adjustable neck version was performed using in vitro experimental procedures and cemented strain gauges. Although strain on the anterior and posterior aspects was less than on the medial and lateral aspects, it was more markedly affected by adjusting the interchangeable neck from straight to anteverted (or retroverted) than strain on the medial and lateral aspects, particularly around the stem tip. There was a highly significant correlation between compressive strain on the side toward which the prosthetic neck was oriented and the extent of neck version, whether anteverted or retroverted. Insertion of a femoral implant in excessive anteversion (or retroversion) may cause noticeably increased stress on the anterior and posterior aspects of the proximal femoral shaft.

Arthroplasty, Replacement, Hip↗

PubMed2002

Synchronization of chaos due to linear response in optically driven semiconductor lasers.

This paper presents physical aspects on chaos synchronization in semiconductor lasers (SLs) by studying synchronization from a fundamental standpoint of driven damped oscillators. We investigate the simple configuration, a chaotic master SL with optical feedback and a solitary slave SL. The point we emphasize is that the slave laser is regarded as a damped oscillator with relaxation oscillation. Linear stability analysis demonstrates that strong injection can enhance the damping of the slave SL. Consequently, the slave SL can have broad and nearly flat spectral characteristics in its driven response, which is sufficient for covering the broadband chaotic driving signal from the master SL. Numerical simulations verify that the slave SL subject to such strong injection synchronizes well with the chaotic driving signal. We consider that the synchronization phenomenon results from a quasilinear driven response of the slave SL with the remarkable spectral characteristics. Moreover, we discuss this type of chaos synchronization in comparison to anticipating-chaos synchronization occurring in our case from conventional complete synchronization theories, and clarify the different physical aspects of the chaos synchronization scheme. We also show that our analysis agrees well with the earlier experiments that could not have been explained by complete synchronization theory.

Journal Article↗