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Biomedical subjects

Y Nagata

Publications and source records attributed to Y Nagata.

At least 109 records · Page 6Linked to original sources
PubMed2000

Association of upper arm circumference at muscle flexion with lumbar spine bone mineral density.

We investigated the association of upper arm circumference at muscle flexion with lumbar spine (L2-L4) bone mineral density (BMD) in 252 postmenopausal Japanese women (mean age, 62.0 +/- 7.6 years; range, 43-78 years) with right-side dominance. Age, age at menopause, years since menopause (YSM), weight, and height were recorded. Dominant upper arm circumference (cm) was measured at muscle flexion. Lumbar spine BMD was measured by dual-energy X-ray absorptiometry (DXA). Correlations between BMD and variables were determined using Pearson's correlation coefficient. Significant predictors of the lumbar spine BMD were determined using stepwise multiple regression analysis. Upper arm circumference, weight, and height were positively correlated with BMD (r = 0.397, 0.343, and 0.323, respectively), whereas YSM and age were inversely correlated with BMD (r = -0.415 and -0.392, respectively). On stepwise multiple regression analysis, YSM, upper arm circumference, and weight were significant predictors of BMD (R2 = 0.322, P < 0.0001). Predicted value of the lumbar spine BMD was calculated by the following formula: Predicted BMD = 0.249 - 0.0078 (YSM) + 0.016 (upper arm circumference) + 0.0046 (weight). Dominant upper arm circumference at muscle flexion in combination with YSM and weight is a useful predictor of lumbar spine BMD.

Adult↗
PubMed2000

Effect of non-weight-bearing body fat on bone mineral density before and after menopause.

OBJECTIVE: To investigate the difference in the effect of non-weight-bearing body fat mass on bone mineral density between premenopausal and postmenopausal women. METHODS: We studied 252 regularly menstruating premenopausal women and 213 postmenopausal women with right side dominance. Age, years since menopause (in postmenopausal women), height, weight, and body mass index were recorded. Bone mineral density of non-weight-bearing sites (ie, arms), weight-bearing sites (ie, lumbar spine including L2-4 and legs), and body fat mass were measured by whole-body scanning with dual-energy x-ray absorptiometry. Body fat mass was also measured by dual energy x-ray absorptiometry. RESULTS: Body fat mass did not differ between groups. In postmenopausal women, body fat mass correlated positively with bone mineral density of the left leg (r =. 41, P <.001), right leg (r =.36, P <.001), left arm (r =.31, P <. 001), and lumbar spine (r =.27, P <.001). The correlation between body fat mass and bone mineral density of the left arm remained significant after adjusting for age, years since menopause, and height. In premenopausal women, body fat mass correlated positively with bone mineral density of left leg (r =.37, P <.001) and right leg (r = 0.31, P <.001), but correlated weakly with bilateral arms (r < or =.19) and lumbar spine bone mineral density (r = 0.13, P <.05). CONCLUSION: The effect of non-weight-bearing body fat on bone mineral density was greater in postmenopausal than premenopausal women.

Absorptiometry, Photon↗
PubMed2000

Differences in umbilical venous and arterial leptin levels by mode of delivery.

OBJECTIVE: To investigate the differences in umbilical venous and arterial leptin levels by mode of delivery. METHODS: Subjects were 30 mothers who had elective cesarean deliveries and 34 mothers who had vaginal deliveries. Umbilical venous and arterial leptin levels were measured immediately after delivery. Maternal age, neonatal gender, neonatal birth weight, placental weight, and gestational duration were recorded. Inter- and intragroup comparisons were made in umbilical venous and arterial leptin levels and obstetric variables. Significant determinants of differences in umbilical venous and arterial leptin levels were investigated. RESULTS: Umbilical venous and arterial leptin levels were higher in the vaginal delivery group (n = 34) than in the cesarean group (n = 30) (P <.01). In the vaginal delivery group, umbilical venous leptin levels were significantly higher than arterial leptin levels (P <.001). These differences were still significant after adjustment for neonatal gender, neonatal birth weight, and placental weight. However, in the cesarean group, leptin levels did not differ between umbilical vein and artery. CONCLUSION: Placental leptin release is augumented during advanced labor.

Adult↗
PubMed2000

Relationship between body fat distribution and bone mineral density in premenopausal Japanese women.

OBJECTIVE: To investigate the relationship between body fat distribution and bone mineral density (BMD). METHODS: Subjects were 282 premenopausal women (mean age +/- standard deviation [SD], 38.8 +/- 8.5 years; range, 20-51 years) with regular menstrual cycles. Baseline characteristics included age, age at menarche, height, weight, body mass index ([BMI], weight/height(2)), and parity. Anthropometric characteristics including the ratio of trunk fat mass to leg fat mass (trunk-leg fat ratio), percentage of body fat, and total body lean mass were measured by whole-body scanning with dual-energy x-ray absorptiometry. Lumbar spine BMD (L2-4) was also measured by dual-energy x-ray absorptiometry. Correlations of BMD to baseline and anthropometric characteristics were investigated using univariate and multivariate analysis. RESULTS: Although height, trunk-leg fat ratio, and total body lean mass were positively correlated with lumbar spine BMD (r =.18, P <.01; r =.17, P <.01; and r =.25, P <.001; respectively), age at menarche was inversely correlated with BMD (r = -.19, P <.01). On multivariable analysis, trunk-leg fat ratio, height, age at menarche, and total body lean mass were still independently correlated with lumbar spine BMD (P <. 05). However, total fat mass was not correlated with BMD. CONCLUSION: Upper body fat distribution rather than overall adiposity is associated with lumbar spine BMD in premenopausal women. Humoral factors associated with body fat mass appear to influence lumbar spine BMD.

Absorptiometry, Photon↗
PubMed2000

HTLV-I transmission from mother to child.

Human T-lymphotropic virus type I (HTLV-I), a causative agent of adult T-cell leukemia, (ATL) is transmitted from mother to child. ATL cells originate from the CD4 subset of peripheral T cells. The main route of mother-to-child transmission is postnatal breast-feeding. Refraining from breast-feeding or limiting the duration of breast-feeding can reduce the risk of mother-to-child transmission. Other than postnatal breast-feeding, there seem to be two routes of HTLV-I transmission from mother to child. One is intrauterine transmission, and the other is via saliva. Intrauterine transmission is rare, although proviral DNA is detected in cord blood samples. HTLV-I proviruses in the cord blood may be defective. HTLV-I proviral DNA and antibodies against HTLV-I are also detected in saliva. However, no report has been published so far which showed direct evidence of HTLV-I transmission via saliva. The placenta can be infected by HTLV-I, but infection does not reach the fetus, possibly apoptosis of placental villous cells because it is induced by HTLV-I infection.

Apoptosis↗
PubMed2000

Reproducibility of geometric distortion in magnetic resonance imaging based on phantom studies.

BACKGROUND AND PURPOSE: Image distortion is one of the major drawbacks of magnetic resonance (MR) imaging for use in radiotherapy treatment planning (RTTP). In this study, the reproducibility of MR imaging distortion was evaluated by repeated phantom measurements. MATERIALS AND METHODS: A grid-pattern acrylic phantom was scanned with a 0.2-Tesla permanent magnetic unit. We repeated a series of scans three times to evaluate the reproducibility of the distortion. In each series, co-ordinates at 432 intersections of the grid were measured for both T1- and T2-weighted spin-echo (SE) pulse sequences. Positional displacements and their variations at the intersections were calculated. RESULTS: Averages of the displacements were distributed between 1.58 and 1.74 mm, and maximum values (MAX) between 12.6 and 15.0 mm. Within 120 mm of the image center, the average values ranged from 0.73 to 0.80 mm, and from 3.4 to 5.0 mm for MAX. The absolute values of the positional variations among three series were distributed between 0.41 and 0.88 mm for average values, and between 1.4 and 4.5 mm for MAX. CONCLUSIONS: The positional variations were mostly within 3 pixels, and most of the positional displacements within the radius of 120 mm of the image center were 2 mm or less. Therefore, it will be possible to use this MR system in RTTP under limited situations, although careful applications are required for RTTP of the body. The development of a computer program to correct image distortion is expected.

Artifacts↗
PubMed2000

Neoadjuvant chemotherapy by transcatheter arterial infusion method for uterine cervical cancer.

PURPOSE: The effects of transcatheter intraarterial infusion of anticancer drugs on the prognosis of cervical cancer were retrospectively studied. MATERIALS AND METHODS: Two or three sessions of transcatheter arterial infusion therapy were performed in 97 patients with primary uterine cervical cancer. The number of patients in stage I, II, III, or IV were 15, 37, 34, and 11, respectively. The drugs infused were cisplatin (60-70 mg/m2), doxorubicin hydrochloride (30-40 mg/m2), mitomycin (15 mg/m2), and 5-fluorouracil (500 mg/body). They were infused via the bilateral internal iliac arteries. Seventy-five patients of the 97 (78%) underwent radical hysterectomy after arterial infusion: stage I (14 of 15), stage II (31 of 37), stage III (25 of 34), and stage IV (5 of 11). Three stage II and nine stage III patients received radical radiation therapy. The other 10 patients (one with stage I, three with stage II, and six with stage IV) did not receive an operation and radiation therapy after arterial infusion because of their distant metastases at the time of operation. Thirty-eight patients of 75 (51%) received postoperative radiation therapy. RESULTS: The complete histologic response rates (no active cancer cells) after arterial infusion were four of 14, four of 31, six of 25, and one of five for stages I, II, III, and IV. The histologic response rates, which showed no parametrial invasion after arterial infusion, were 12 of 14, 24 of 31, and 15 of 25 for stages I, II, and III. The histologic response rates, which demonstrated no lymph node metastases after arterial infusion, were 12 of 14, 24 of 31, and 19 of 25 for stages I, II, and III. The overall 5-year survival rates of the patients with stages I, II, and III were 93.3%, 58.7%, and 69.7%, respectively. The 5-year survival rates of the operated patients with stages I, II, and III were 100%, 60.5%, and 63.6%, respectively. The 5-year survival rates of the irradiated patients with stage III was 87.5%. Leukocytopenia and thrombocytopenia occurred as an acute complication in 75% and 79% of the patients, respectively. As a late complication, ileus occurred in 7%. CONCLUSION: Arterial infusion may improve the prognosis of patients with cervical cancer without increasing the incidence of late complications.

Adenocarcinoma↗
PubMed2000

Sonolytic degradation of hazardous organic compounds in aqueous solution.

Benzene, chlorobenzene, 1,2-, 1,3-, 1,4-dichlorobenzene, biphenyl, and polychlorinated biphenyls such as 2-, 4-chlorobiphenyl and 2,2'-dichlorobiphenyl in aqueous solutions have been subjected to sonolysis with 200 kHz ultrasound at an intensity of 6 W cm-2 under an argon atmosphere. 80-90% of initial amount of these compounds were degraded by 30-60 min of sonication when the initial concentrations were 10-100 mumol l-1. The degradation rate of these compounds increased with increase in their vapor pressures. In all cases of sonolysis of chlorinated organic compounds, an appreciable amount of liberated chloride ion was observed.

Journal Article↗
PubMed2000

Sonochemical degradation of chlorophenols in water

Sonochemical degradation of dilute aqueous solutions of 2-, 3- and 4-chlorophenol and pentachlorophenol has been investigated under air or argon atmosphere. The degradation follows first-order kinetics in the initial state with rates in the range 4.5-6.6 microM min-1 under air and 6.0-7.2 microM min-1 under argon at a concentration of 100 microM of chlorophenols. The rate of OH radical formation from water is 19.8 microM min-1 under argon and 14.7 microM min-1 under air in the same sonolysis conditions. The sonolysis of chlorophenols is effectively inhibited, but not completely, by the addition of t-BuOH, which is known to be an efficient OH radical scavenger in aqueous sonolysis. This suggests that the main degradation of chlorophenols proceeds via reaction with OH radicals; a thermal reaction also occurs, although its contribution is small. The addition of appropriate amounts of Fe(II) ions accelerates the degradation. This is probably due to the regeneration of OH radicals from hydrogen peroxide, which would be formed from recombination of OH radicals and which may contribute a little to the degradation. The ability to inhibit bacterial multiplication of pentachlorophenol decreases with ultrasonic irradiation.

Journal Article↗
PubMed2000

Comparison of the panoramic radiographic and CT features of post-Caldwell-Luc maxillary sinuses.

OBJECTIVE: To clarify the panoramic radiographic features of the post-Caldwell-Luc maxillary sinus. METHODS: The panoramic radiographs were compared with the axial CT scans of 48 symptomatic post-Caldwell-Luc maxillary sinuses which had been operated on more than 5 years previously. RESULTS: The two characteristic features of the post-Caldwell-Luc maxillary sinus on panoramic radiographs were a right-angled triangular shape, due to absence of the floor of the maxillary sinus and radiopacity of the posterior wall and zygomatic bone, and an ill-defied panoramic innominate line. This shape was related to the finding of a contracted sinus with a radiolucent lumen on the CT scans. There was also close relationship between the ill-defined panoramic innominate line and thickened posterior wall on the CT scans. CONCLUSION: The characteristic features of the post-Caldwell-Luc maxillary sinus on panoramic radiographs were a right-angled triangular shape and an ill-defined panoramic innominate line. These features were related to a contracted sinus and a thickened posterior wall on the CT scans.

Adult↗
PubMed2000

Unilateral pedal lymphography in patients with filarial chyluria.

OBJECTIVE: To evaluate the usefulness of unilateral pedal lymphography in patients with filarial chyluria. PATIENTS AND METHODS: Of 114 patients with filarial chyluria, all underwent lymphography (unilateral pedal in 106) and 55 underwent selective ureteric sampling for chyle. RESULTS: Unilateral pedal lymphography in the 106 patients detected lymphaticorenal fistulae (LRF) in 104 (98%). Lymphatic crossover was seen in all 106 patients, from the second sacral segment to the first lumbar segment. The most frequent crossover site was at the L5 level (87%). There was complete correlation between the side of LRF and the side of chyluria as assessed by selective ureteric sampling. CONCLUSION: Unilateral pedal lymphography can detect LRF via lymphatic crossover even when it is on the opposite side from that injected with contrast agent. The advantages of unilateral lymphography over bilateral procedures are that it is easy to identify crossover channels, and the discomfort for the patient is reduced because there are fewer incisions and it is quicker. Unilateral lymphography is recommended as the initial method when lymphography is indicated in filarial chyluria.

Adult↗
PubMed2000

Results of breast-conserving therapy for early stage breast cancer: Kyoto University experiences.

This study evaluated the results of breast-conserving therapy (BCT). Nine hundred six patients who underwent BCT at our hospital between November 1987 and February 1998 were analyzed. The mean age was 48 years. According to the Union Internationale Contre le Cancer 1997 classification system, stages 0, I, IIA, IIB, IIIA, and IIIB were 37, 400, 344, 117, 7, and 1, respectively. Radiation therapy consisted of 50 Gy to the ipsilateral whole breast. Boost irradiation of 10 Gy was administered to 186 of 231 patients with close or positive margins. Nearly all patients received adjuvant chemohormonal therapy with tamoxifen and 5-fluorouracil or its derivatives for 2 years. The minimum and median follow-up periods were 18 and 52 months, respectively. The 5-year overall survival, cause-specific survival, local recurrence-free survival, and disease-free survival rates were 97.3%, 98.4%, 98.1%, and 91.5%, respectively. Local recurrence in preserved breast occurred in 20 patients 7 to 86 months after surgery. Multivariate analysis revealed that the most predictive factor for disease-free survival rates and distant failures was the number of pathologically positive lymph nodes (p < 0.0001), and that the factor for local failure was marginal status (p = 0.005). This study demonstrated that BCT was suitable for the treatment of early-stage breast cancer with its reasonable survival rates and acceptable toxicity.

Breast Neoplasms↗
PubMed2000

Detection of lymphocytes productively infected with Epstein-Barr virus in non-neoplastic tonsils.

Epstein-Barr virus (EBV) persists for life in the infected host. Little is known about EBV reactivation and regulation of virus persistence in healthy individuals. We examined tonsils of chronic tonsillitis patients to detect EBV transcripts, EBV genomes and lytic proteins. LMP1 transcripts were observed in 11 of 15 specimens and BZLF1 transcripts were detected in six. Multiple copies of EBV genome equivalents per cell, and ZEBRA- and viral capsid antigen-positive cells were also detected in tonsillar lymphocytes. These results indicate that EBV productively infected cells may survive in the face of immune surveillance in the tonsils. Thus, EBV replication may occur in tonsillar lymphocytes, and tonsillar lymphoid tissues may play a role in the maintenance of EBV load in vivo.

DNA, Viral↗
PubMed2000

Body fat distribution as a risk factor of endometrial cancer.

OBJECTIVE: To investigate the relative contributions of upper body fat distribution and overall adiposity to endometrial cancer risk. METHODS: Subjects were 63 postmenopausal women with endometrial cancer aged less than 70 years and 201 age-matched controls. Age, age at menopause, years since menopause, height, weight, and body mass index were recorded at the time of admission. The trunk-leg fat ratio, body fat mass, trunk fat mass, and the percentage of body fat were measured by dual-energy X-ray absorptiometry. RESULTS: Trunk-leg fat ratio was higher in endometrial cancer patients than in controls (1.40 +/- 0.59 vs 1.23 +/- 0.39, p < 0.05). Whereas, other variables including age at menopause, percentage of body fat, body fat mass, and body mass index did not differ between the 2 groups. On stepwise multiple regression analysis, the trunk-leg fat ratio was still correlated with the presence of endometrial cancer (p < 0.05). CONCLUSIONS: Upper body fat distribution rather than overall adiposity is associated with endometrial cancer risk.

Adipose Tissue↗
PubMed2000

Primary vaginal stone in an 11-year-old recumbent girl.

Primary vaginal stones are extremely rare, particularly in young women. We describe the occurrence of a primary vaginal calculus in a severely retarded 11-year-old girl who was not diagnosed until she was examined using computerized tomography. We postulate that the calculus was formed as a consequence of urinary contamination of the vagina in association with incontinence and prolonged maintenance in a recumbent posture.

Calculi↗
PubMed2000

Determination of alpha-tocopherol and alpha-tocopherylquinone in rat tissues and plasma by high-performance liquid chromatography with electrochemical detection.

Alpha-tocopherol and alpha-tocopherylquinone in rat tissues and plasma were determined simultaneously by using high-performance liquid chromatography-electrochemical detection (HPLC-ED) with dual electrodes in the series mode. Biological samples were saponified in the presence of a mixture of butylated hydroxytoluene, ascorbic acid, and pyrogallol and then extracted with hexane. The compounds were separated on a C18 column using a mobile phase containing 95% methanol and 0.05 M sodium perchlorate as the supporting electrolyte. After HPLC separation, alpha-tocopherylquinone was first reduced at an upstream electrode at -500 mV Both alpha-tocopherol and the reduction product of alpha-tocopherylquinone were then oxidized downstream at +600 mV. Only the downstream electrode current was monitored for the determination. Linearity of the standard curves was obtained over the range 5-30 pmol for alpha-tocopherol and alpha-tocopherylquinone. Minimum detectable quantities (S/N of 3) were 0.25 pmol for alpha-tocopherol and 0.31 pmol for alpha-tocopherylquinone. The method was applied to analysis of the contents of alpha-tocopherol and alpha-tocopherylquinone in rat tissues and plasma. By hyperoxia, the content of alpha-tocopherol was decreased remarkably in lung, and in contrast, the contents of alpha-tocopherylquinone were increased in all tissues studied with the exception of plasma, though the content of alpha-tocopherylquinone in normal rats is quite small. The technique is particularly useful in the quantitation of the oxidation of alpha-tocopherol in biological samples.

Animals↗
PubMed2000

Copper(II)-catalyzed oxidation of d-alpha-tocopherol by oxygen in aqueous solution.

alpha-Tocopherol (alpha-Toc) was solubilized in aqueous solutions using 13 solubilizing agents and the products of oxidation by oxygen in the presence and the absence of Cu(II) were analyzed by HPLC. In the presence of Cu(II), the oxidation was accelerated and 5-formyl-7,8-dimethyltocol and alpha-tocoquinone were the major oxidation products. Their yields greatly increased in the presence of Cu(II). The yields and the rates of formation of the products were dependent on the properties of solubilizing agents and other conditions as well as the presence of Cu(II) or other metal ions. It is suggested that slight changes in the structure of the solubilizing agents affect the course of the reaction.

Catalysis↗