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Biomedical subjects

N Ikeda

Publications and source records attributed to N Ikeda.

At least 91 records · Page 5Linked to original sources
PubMed2000

Determination of azide in blood and urine by gas chromatography-mass spectrometry.

A sensitive and simple method for determining azide in blood and urine using an extractive alkylation technique was devised. This inorganic anion was alkylated with pentafluorobenzyl bromide using tetradecyldimethylbenzylammonium chloride as the phase-transfer catalyst. 1,3,5-Tribromobenzene was used as an internal standard. The obtained derivative was analyzed by gas chromatography-mass spectrometry using the negative ion chemical ionization mode with isobutane as the reagent gas. The calibration curves for azide were linear over the concentration range from 1 to 200 nmol/mL in blood and urine, and the lower limit of detection was 0.5 nmol/mL for blood and urine. The accuracy and precision of the method were evaluated, and the coefficients of variation were found to be lower than 10%.

Forensic Medicine↗
PubMed2000

Prognostic significance of occult bone marrow micrometastases of breast cancer detected by quantitative polymerase chain reaction for cytokeratin 19 mRNA.

Amplification of cytokeratin 19 (CK19) transcripts by reverse transcriptase-polymerase chain reaction (RT-PCR) has been shown to be a highly sensitive assay for the detection of bone marrow micrometastases (BMM) of breast cancer, but recent studies have demonstrated the occurrence of false-positive results due to low-level, illegitimately transcribed CK19 in normal bone marrow tissue. One approach to solve this problem is to develop a quantitative CK19 RT-PCR assay and to introduce a cut-off value which can distinguish between illegitimate expression and cancer-specific expression levels. In the present paper, we describe a quantitative CK19 RT-PCR assay using a real-time automated PCR system. The number of CK19 transcripts was normalized to that of GAPDH transcripts as an internal control for quality and quantity of cDNA. The cut-off value for the ratio of CK19 to GAPDH transcripts was set at 10(-4) since the ratio never exceeded this value in the control bone marrow samples (n = 12). In total, 117 bone marrow aspirates from stage I - III patients with invasive breast cancers were subjected to CK19 RT-PCR assay and immunocytological examination. Forty (34.2%) were found to be BMM-positive by CK19 RT-PCR assay whereas only three (2.6%) were found to be BMM-positive by immunocytology. Multivariate analysis has shown that occult BMM detected by CK19 RT-PCR is a significant risk factor for relapse, being independent of axillary lymph node metastases.

Bone Marrow Neoplasms↗
PubMed2000

Direct discrimination and full-day disclosure of ventricular parasystole on new heart rate tachograms.

INTRODUCTION: To discriminate ventricular parasystole from fixed coupling interval ventricular premature complexes (VPCs), we developed a new diagnostic method using a dot distribution pattern corresponding to VPCs recorded on a heart rate tachogram using ambulatory ECG monitoring data. We tested our hypothesis that widely scattered VPC dots on instantaneous heart rate tachograms indicate a constant VPC-VPC interval compatible with parasystole. METHODS AND RESULTS: Patients with frequent VPCs > 5,000/day) were divided into two groups depending on the tachogram dot distribution patterns: group S (n = 10, aged 61 +/- 16 years) showed widely scattered VPC dot distribution, whereas group F (n = 10, 60 +/- 17 years) showed fixed VPC dot distribution limited to a narrow zone. Using digitized R-R interval data, full-day heart rate tachograms and VPC-VPC intervals were depicted simultaneously. Group S demonstrated constant basic VPC-VPC intervals (1,285 to 2,052 msec, mean 1,738 +/- 219), with a coefficient of variation (CV) of 0.061 +/- 0.018. Their VPC coupling intervals were markedly variable (651 +/- 113 msec; CV = 0.193 +/- 0.034). Each patient's basic VPC-VPC intervals showed small diurnal alterations (minimum -13% +/- 3% to maximum +15% +/- 6%). VPC-VPC intervals in group F were not constant and showed marked variation. Group F VPC coupling intervals were shorter and constant (480 +/- 30 msec, P = 0.0002; with CV = 0.076 +/- 0.013, P < 0.0001). CONCLUSION: Ventricular parasystole with constant VPC-VPC intervals consistently became evident based on VPC dot patterns recorded on heart rate tachograms.

Adolescent↗
PubMed2000

Trehalose 6,6'-dimycolate (Cord factor) enhances neovascularization through vascular endothelial growth factor production by neutrophils and macrophages.

Trehalose 6,6'-dimycolate (TDM) plays important roles in the development of granulomatous inflammation during infection with Mycobacterium spp., Rhodococcus spp., etc. To reveal the augmenting effect of TDM on vascular endothelial growth factor (VEGF) production and neovascularization, we investigated murine granulomatous tissue air pouches induced by Rhodococcus sp. strain 4306 TDM dissolved in Freund's incomplete adjuvant (FIA), comparing them to pouches treated with FIA alone. Histologically, granulomatous tissue and new vessel formation, which reached a maximum at day 7, was greatly enhanced by treatment with TDM. At day 1, VEGF-positive neutrophils accumulated in the pouch wall with frequency of 95% of total infiltrating cells, adhering to TDM-containing micelles. By day 3, granulomatous tissue and new vessels started to develop, and VEGF-positive macrophages appeared in a small number and gradually increased in number thereafter. The pouch contents of VEGF, interleukin-1beta, tumor necrosis factor alpha, and transforming growth factor beta were significantly elevated in TDM-treated pouches, with peaks at days 1, 0.5, 1, and 3, respectively, compared to those of control pouches, while that of basic fibroblast growth factor showed no significant increase. Treatment with anti-VEGF antibody inhibited TDM-induced granulomatous tissue formation and neovascularization, and administration of recombinant VEGF into pouches treated with FIA alone induced neovascularization comparable to that in the TDM-treated pouches. Incubation of neutrophils and macrophages on TDM-coated plastic dishes increased the VEGF release. The present results indicate that TDM augments VEGF production by neutrophils and macrophages and induces neovascularization in the granulomatous tissue.

Animals↗
PubMed2000

Oral cancer screening as an integral part of general health screening in Tokoname City, Japan.

OBJECTIVES: To measure the attendance and compliance rates in oral mucosal screening (OMS) offered as part of a general health screen (GHS) undertaken as an organised programme in Japan. METHODS: In 1996, all adults over the age of 40 years resident in Tokoname City were invited by letter to attend a free GHS annually, conducted by the municipal cooperation and the medical and dental societies of Tokoname City. In the later years only those who attended in 1996 were reinvited. Females aged less than 39 years were also allowed to attend if they wished to participate in the GHS. The GHS consisted of completion of a self administered questionnaire to identify past and current illnesses and any medications used by the screened population coupled with a routine physical check, chest x ray, ECG, and blood and urine examination. The GHS was programmed annually during the years 1996 to 1998. All those attending the GHS were invited to participate in an OMS conducted under the same roof by a visiting dentist (n=37). A referral pathway was established for screen positives requiring follow up. RESULTS: A total of 19 305 subjects (5955 males, 13350 females; mean age 59.2 years; 7033 in 1996, 6289 in 1997, and 5983 in 1998) attended the GHS. Of those who attended the GHS, 19 056 (98.7%) attended the OMS (1.3% refused). This rate was fairly constant over the three years. Excluding repeat examinations, new cases recruited for OMS over the three years were 8723. Of those participating in OMS, 4269 (60.7%) attended all three years. In the cohorts examined, screening dentists recorded oral mucosal lesions in 5.4% in 1996, in 4.0% in 1997, and in 2.6% in 1998. Overall, this amounted to a positive detection rate of 4.1%, or 4.9% excluding repeat examinations. A higher prevalence of oral pre-cancer was recorded among male smokers. CONCLUSIONS: The overall results suggest that although compliance with attending a free GHS was low (26.2%) among Japanese subjects over 40 years of age, of those who complied 74-76% reattended annually. Hence a satisfactory participation rate can be obtained in Japan for OMS when this is coupled to a GHS conducted at the same visit.

Adult↗
PubMed2000

Effects of the ethyl and benzyl ethers of indenestrols A and B on cytotoxicity in Chinese hamster V79 cells.

We recently investigated the relationship between the structures of various indenestrols and their cytotoxicity, and reported that indenestrol A (IA), a metabolite of the synthetic nonsteroidal estrogen diethylstilbestrol, and indenestrol B (IB), an analog of IA, disrupt the microtubule architecture of Chinese hamster V79 cells in vitro. We then synthesized 16 optically active indenestrol derivatives by substituting monoethyl, monobenzyl and diethyl ether groups at the 6- and/or 4'-hydroxyl positions, and examined their cytotoxic activities in Chinese hamster V79 cells. The results indicated that the monoethyl ethers had cytotoxic activities similar to monomethyl ethers. However, the (+)- and (-)-monobenzyl ethers were less cytotoxic than the corresponding monomethyl and monoethyl derivatives.

Animals↗
PubMed2000

Microvascular decompression for cochlear symptoms.

OBJECT: The object of this study was to evaluate the efficacy of a new neurovascular decompression technique in relieving symptoms of cochlear nerve dysfunction. METHODS: Nineteen patients with slowly progressive hearing loss, low-frequency fluctuating hearing loss, and high-pitched tinnitus due to neurovascular compression (NVC) of the eighth cranial nerve in a triangular space between the seventh and eighth cranial nerves (the VII-VIII triangle) of the cerebellopontine angle (CPA) were treated using a new technique for microvascular decompression that was developed by anatomical study in 24 cadaver specimens of the CPA. In 12 of 19 patients the anterior inferior cerebellar artery (AICA) was observed to cause compression in the VII-VIII triangle and this vessel was easily mobilized medially for placement of a silicone sponge or Teflon cushion between the compressing artery and nerve. Postoperatively, hearing loss of 20 dB or more that was present in 11 of the 19 patients with NVC improved by more than 5 dB in seven (64%), including the patient with the most severe hearing loss. Of 18 patients presenting with tinnitus preoperatively, eight (44%) had no tinnitus and an additional nine (for a total of 94%) had good improvement in tinnitus after surgery and at long-term follow up. CONCLUSIONS: The microvascular decompression technique described is highly successful in treating symptoms due to direct or indirect compression of the cochlear nerve, with minimal risk of complications. Recordings of auditory brainstem responses confirmed the clinical diagnosis of NVC of the eighth cranial nerve and correlated with clinical results after microvascular decompression of the cochlear nerve.

Adult↗
PubMed2000

[Molecular biological diagnosis].

Biological behavior of lung cancer was evaluated by basic study. Malignancy Associated Change is the concept that the nuclear features of normal cells in the vicinity of cancer show subtle morphological difference from those of healthy individuals. The difference was recognized by high resolution cytometry and the expression of MAC cells was correlated with the degree of abnormality of chest diseases. Comparative genomic hybridization and fluorescence in situ hybridization were performed to investigate genetic abnormality of. Multiple genetic abnormalities and chromosomal instability showed poor prognosis. Two dimensional electrophoresis was employed to detect the expression of the specific protein of lung cancer. TAO2 was proved to be specific to well differentiated adenocarcinoma. Also, metabolic analysis will be employed for cell analysis.

Biomarkers, Tumor↗
PubMed2000

[An outbreak of pulmonary tuberculosis in the dormitory of construction labors suspected to have been due to exogenous reinfection].

We report an outbreak of pulmonary tuberculosis (TB) in a dormitory of construction labors, and this outbreak is suspected to have been caused by exogenous reinfection, based on the restriction fragment length polymorphism (RFLP) analysis and other findings. After a patient entered our hospital with active TB, 12 new other patients were discovered by contacts examination. These patients lived together in the same dormitory. They were all male and single, and were aged from 43 to 63 years old. Except one patient (No. 3) previously treated for TB for three months about 2 years ago and was suspected to be the index case of this outbreak, 12 other patients did not have a medical history of TB. The bacilli cultured from 11 patients (No. 1-11) were tested by RFLP analysis, three patterns were identified, and the fingerprints from 9 patients (No. 1-9) were identical, and the patterns of incomplete resistance of some antituberculous drugs were quite similar between No. 1-9 and No. 12 and between No. 10 and No. 13, respectively. The locations of the main lesions of TB on chest X-ray pictures were the apico-posterior segments of bilateral upper lobes. No signs suspected to indicate primary tuberculosis were detected. Considering the rate of tuberculous infection in Japan among the middle age and above as well as the identical RFLP results, most of patients in this outbreak except the index case No. 3 were suspected to have TB due to the exogenous reinfection.

Adult↗
PubMed2000

[A case of primary tuberculosis, with subpleural infiltrative shadow, hilar lymphadenopathy perforated into bronchus, causing tuberculous pneumonia].

A 47-year-old asymptomatic female was referred to our outpatient department with pulmonary infiltration in the left S6. PPD skin test revealed 12 x 11 mm redness. The infiltration disappeared without treatment. Hilar lymphadenopathy appeared 2 months after the first visit. In 6 months after the first visit, the hilar lymphadenopathy disappeared without treatment, but infiltration appeared in the left S6 (different site to that of the first visit). A repeated PPD revealed 47 x 40 mm redness and 20 x 15 mm induration. Bronchoscopy revealed a polipoid lesion at the orifice of left B6, MTD (Mycobacterium tuberculosis direct test) was positive from the bronchial washing of left B6. She was diagnosed as tuberculosis based on the courses and radiographic appearances. After antituberculous chemotherapy, the pulmonary infiltration and the polipoid lesion at the orifice of left B6 improved.

Bronchial Diseases↗
PubMed2000

Traumatic false aneurysm of the descending aorta which ruptured to right thoracic cavity.

A 54-year-old male, who had been involved in a traffic accident one week earlier, suddenly died in hospital without any warning. Autopsy revealed right hemothorax due to rupture of a subpleural hematoma of the right lung which was connected to a false aneurysm of the descending aorta. It is likely that the false aneurysm began to grow just after the traffic accident, forming an aortopleural fistula due to preceding adhesion. This led to the formation of a hematoma in the right subpleural space, which ruptured one week after the traffic accident. The present case indicates that the natural course and pathogenesis of traumatic false aneurysm depends upon the preceding local anatomical circumferences.

Accidents, Traffic↗
PubMed2000

An autopsy case of accidental asphyxiation in a storage room for apples.

A 12-year-old boy died in a storage room and his mother was rescued from the same storage room, where many apples were being stored. The atmosphere in the room was strictly controlled and the concentration of oxygen (O2) was recorded. The cause of death was suffocation. According to the records, the concentration of O2 was about 2.7% when the boy died. On the other hand, it was about 3.4% when his mother entered the room and she survived, although she remained unconscious for about four hours. These findings show that the absolute concentration of O2 causing acute death due to O2 deficiency is approximately 2.5-3.0%.

Accidents↗
PubMed2000

[Thoracoscopic pleural biopsy under local anesthesia using a 2 mm laparoscope].

Thoracoscopy is indicated in patients with undiagnosed effusion after conventional methods. It has been usually performed under general anesthesia or using a thoracoscope with a thoracoscope with a diameter over 5 mm. However, it is an invasive diagnostic technique. We evaluated the feasibility of thoracoscopic pleural biopsy under local anesthesia using a 2 mm laparoscope. Six patients with a pleural effusion of unknown etiology after conventional methods, underwent thoracoscopy under local anesthesia. A 2 mm laparoscope and biopsy forceps (2 mm Minisite, United States Surgical Corp., USA) was used in all patients. Pleural fluid was removed, and the thoracic cavity was inspected. Thoracoscopic intercostal blocks were performed with 1% lidocaine, and then a biopsy was performed. The biopsy specimen was sent for histopathology. Three patients were shown to have carcinomatous pleurisy, two of them with localized lesions less than 10 mm. In the remaining three patients, non-specific diagnoses were made, but long-term follow-up revealed no malignant pleural disease. Although the pictures obtained using a 2 mm laparoscope were inferior in quality, they were adequate for the detection of malignant lesions in the pleural cavity. There were no procedure-related complications. These findings suggest that thoracoscopy using a 2 mm laparoscope is (1) a useful diagnostic tool in cases of pleural malignancy; (2) a minimally invasive method with the advantage of being easily performed under local anesthesia. Thus, thoracoscopic pleural biopsy using a 2 mm laparoscope appears to be useful for undiagnosed pleural effusion.

Anesthesia, Local↗
PubMed1999

Thermodynamics of Formation of and Adsorption at Interfaces with a Floating Lens.

The thermodynamic equations of the formation of and adsorption at interfaces were derived for a three-phase system having a floating lens with curved interfaces. The surface excess quantities were defined both in the H convention based on the two dividing surfaces and in the P convention based on the four dividing surfaces. Their physical significance and utilities were discussed. The equations were simplified to be applicable to the three-component systems with the plane A/W interface and a relatively large size of lens, such as the air/water/long-chain alcohol systems. The formulation and geometrical consideration of the two conventions with respect to this simple cases revealed that the H convention introduces the distance between the two dividing surfaces and the P convention introduces three kinds of distances between the four dividing surfaces including a kind of thickness of the reference oil lens phase in the A/W interfacial region. Furthermore, the general equations were simplified to be applicable to four-component systems such as the air/oil solution of a surface-active substance/water or the air/oil/aqueous solution of a surfactant with a floating oil lens. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

The Excess Thermodynamic Quantities of Adsorption of a Binary Nonionic Surfactant Mixture.

The thermodynamic relations were developed for examining the miscibility of surfactants in the adsorbed film from the viewpoints of the thermodynamic quantities of adsorption such as Gibbs free energy, entropy, volume, enthalpy, and energy. The deviation from the additivity relation, the straight line connecting the thermodynamic quantities of the respective pure surfactants as a function of the composition of the adsorbed film, was proved to yield the corresponding excess quantities of adsorption. The criterion of the ideal mixing was offered and summarized with respect to the composition of adsorbed film, the mean area occupied by surfactants, and the thermodynamic quantities of adsorption. The resulting equations were applied to the simple nonionic surfactants mixture of decyl methyl sulfoxide (DeMS) and octyl methyl sulfoxide (OMS). The surface tension of the aqueous solution was measured as a function of not only the total molality and mole fraction of surfactants but also temperature under atmospheric pressure. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Structure Effect on Nonideal Mixing of Alkyl Methyl Sulfoxide and Alkyldimethylphosphine Oxide in Adsorbed Film and Micelle.

The surface tension of aqueous solutions of the octylmethylsulfoxide (OMS)-decyldimethylphosphine oxide (DePO) and decylmethylsulfoxide (DeMS)-octyldimethylphosphine oxide (OPO) mixtures was measured as a function of the total molality of the surfactants and the composition in the surfactants. Compositions in the adsorbed film and micelle were thermodynamically evaluated from the total molality vs composition and the critical micelle concentration (CMC) vs compositon curves, respectively. The phase diagrams of adsorption and micelle formation were drawn and compared with those of the DeMS-DePO mixture previously studied. A large gap in composition was observed between the adsorbed film and the micelle coexisting at the CMC and ascribed to the differences in geometric structure between them and the constituent molecules. Negative deviation from ideal mixings in adsorbed film and micelle was observed for the OMS-DePO mixture, whereas a positive one was observed for the DeMS-OPO. The structure effect on the nonideal mixings was clarified by using the excess thermodynamic functions of adsorption and micelle formation calculated from the activity coefficients in the adsorbed film and micelle. Copyright 1999 Academic Press.

Journal Article↗