Biomedical subjects
Publications and source records attributed to Kazuhiko Sato.
Magnetic nanoparticles-supported quaternary ammonium and phosphonium salts were prepared and evaluated as phase-transfer catalysts. Some of them exhibited good activities that were comparable to that of tetra-n-butylammonium iodide. The catalysts were readily separated using an external magnet and reusable without significant loss of their catalytic efficiency.
The collimator scatter factor (S(c)(MLC)) at MLC irregular fields for high-energy X-ray irradiation is generally assumed to be equal to the jaw collimator scatter factor (S(c)(jaw)) of the square field equivalent to the rectangular field produced using pairs of jaw collimators. However, this assumption becomes strained as the ratio of the MLC equivalent square field side to the jaw collimator equivalent square field side decreases. In this study, for 4 MV and 10 MV X-rays, the collimator scatter factor (S(c)(MLC)) for an MLC irregular field could be evaluated with a high degree of accuracy using the MLC irregular correction (F(MIC)) factor or the jaw collimator correction (F(JCC)) factor.
An effective method was proposed to remove obstinate boron nitride phase impurities in boron nitride nanotubes (BNNTs). The method is based on strong interactions between BNNTs and a conjugated polymer wrapping them and significant weight and size difference between BNNTs and impurities. The as-grown samples and purified samples were compared through detailed characterization, using scanning electron microscopy, transmission electron microscopy, and Raman and Fourier transformed infrared spectroscopy. The results reveal that impurities are effectively removed and resultant BNNTs possess perfect crystallization.
We report a case of metastatic breast cancer with pericardial effusion that was successfully treated with weekly paclitaxel. A 46-year-old woman underwent modified radical mastectomy in April 1997 and was readmitted to the hospital for dyspnea in March 2002. A diagnosis of cardiac tamponade due to breast cancer relapse was made, and the patient was treated with weekly paclitaxel (80 mg/m2) and insertion of a drainage catheter. This treatment was effective in preventing reaccumulation of the pericardial effusion until her death. The concentration of paclitaxel in the cardiac effusion was 45 ng/ml at 3 h, 15 ng/ml at 12 h, and less than 10 ng/ml at 24 h after paclitaxel infusion, indicating good transportation of the drug from the blood to the pericardial effusion. These findings suggest that weekly intravenous infusion of paclitaxel could be effective for the treatment of patients with malignant pericardial effusion.
BACKGROUND: Breast conserving treatment (BCT) consists of breast-conserving operation and followed by whole-breast irradiation (WBI). Accelerated partial breast irradiation (APBI) is being considered as a possible alternative to WBI. Neoadjuvant APBI might provide more benefit than postsurgical APBI because tumor downstaging will enhance the likelihood of BCT. METHODS: APBI was delivered as 50 Gy in 5 fractions over 5 days before operation for patients with breast cancer of 3 to 4 cm in diameter. Patients with tumors 3 cm or less were deemed to be candidates for breast-conserving operation. RESULTS: Between September 1998 and August 1999, 12 women were enrolled. The mean tumor diameter and volume were reduced from 3.4 to 1.8 cm (reduction rate: 47%) and from 8.1 to 2.2 cm3 (reduction rate: 71%), respectively. The mean pathologic tumor size was 1.5 cm, and a complete pathologic response was found in 1 patient (8%). All patients were eligible for breast-conserving operation. No ipsilateral breast recurrences have been observed to date. CONCLUSIONS: This is the first report of neoadjuvant APBI for relatively large breast cancers. Although the number of participants was small, these results would encourage the development of clinical trials exploring the efficacy of neoadjuvant APBI.
The insulin-like growth factor receptor type 1 (IGF1R) is suggested to play important roles in cancer cell growth through cross-talk with hormone receptors and growth factor receptors. However, its clinical significance in breast cancers in vivo is still unclear. We examined immunohistochemically the expression of IGF1R, phosphorylated-AKT (pAKT) and phosphorylated-ERK1/2 (pERK1/2) using tissue microarray slides containing 150 cases of primary breast carcinoma. Their mutual correlation and correlation with the status of hormone receptors epidermal growth factor receptor and human epidermal growth factor receptor type 2 were also investigated. IGF1R overexpression was detected in 71 cases (47%), and was correlated with lower nuclear grade (P = 0.03), positive estrogen receptor (ER) and/or progesterone receptor status (P = 0.002). pERK1/2 expression, detected in 53 cases (35%), was correlated with positive ER (P < 0.0001) and lower nuclear grade (P = 0.014). pAKT expression, detected in 88 cases (59%), was not correlated with nuclear grade, hormone receptors status or other clinical parameters. Of the 71 IGF1R-overexpressing tumors, pERK1/2 expression was detected in 27 (56%) of 48 ER-positive cases but in only four (17%) of 23 ER-negative cases (P = 0.022). In contrast, pAKT expression was constantly (64% or higher) detected irrespective of hormone receptor status in IGF1R-overexpressing breast cancers. Taken together, these findings suggest that IGF1R overexpression might activate pERK1/2 and pAKT in hormone receptor-positive breast cancer, but activate only pAKT in hormone receptor-negative breast cancer.
To investigate how urinary frequency and incontinence affect the patient's subjective quality of life (QOL) and whether an improvement in objective findings by medical treatment affects his/her subjective QOL, a voiding diary using the King's Health Questionnaire (KHQ) and International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) was delivered to patients with urinary frequency and/or incontinence before and after treatment with propiverine hydrochloride for 8 weeks. Sixty-eight patients completed the diary and the questionnaires. Objective symptoms decreased significantly with respect to the mean frequency of urination and to the mean incidence of urinary incontinence. The KHQ and ICIQ-SF scores improved significantly with respect to all domains except personal relationships in the KHQ. In the KHQ, furthermore, a significant correlation was found between decreased incidence of urinary incontinence and improvement in role limitations and between decreased incidence of urinary incontinence and improvement in emotional problems. In the ICIQ-SF, a significant correlation was found between decreased incidence of urinary frequency and subjective improvement in quantity of leakage, between decreased incidence of urinary frequency and improvement in subjective QOL scores, between decreased incidence of urinary frequency and improvement in the total ICIQ-SF score, and between decreased incidence of urinary incontinence and improvement in subjective QOL scores. Thirty-two episodes of adverse reactions were observed. None of them were serious. These results suggest that an improvement in objective symptoms with propiverine hydrochloride favorably improves subjective QOL of the patient, and provide further evidence about the safety and efficacy of propiverine hydrochloride.
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Endocrine therapies that profoundly decrease estrogen levels potentially have a detrimental effect on the cardiovascular system. This study evaluated the effect on lipid metabolism of one such agent, the new generation aromatase inhibitor anastrozole, compared with tamoxifen, when used as adjuvant treatment in postmenopausal Japanese women with early breast cancer. All patients had completed primary surgery and were randomized to anastrozole 1 mg once daily (n=22) or tamoxifen 20 mg once daily (n=22). Anastrozole significantly reduced levels of triglycerides and remnant-like particle cholesterol, whereas tamoxifen significantly increased these. Activity of lipoprotein lipase and levels of high-density lipoprotein cholesterol significantly increased after anastrozole treatment. In contrast, activity of hepatic triglyceride lipase, also a key enzyme of triglyceride metabolism, significantly decreased following treatment with tamoxifen. We thus conclude that in our study anastrozole had a beneficial effect on lipid profiles of postmenopausal women with early breast cancer after 12 weeks of treatment.
BACKGROUND: Sentinel node (SN) biopsy using a radiotracer is easy to learn, reproducible, and performed by the majority of breast cancer surgeons. However, this technique raises the question: what is the optimal particle size of colloid? METHODS: Patients were injected with conventional tin colloid (median particle diameter: 700 nm) and the predominant particle size of radiocolloid retained in the SN was measured using electron microscopy. This showed a narrow distribution of colloidal size (100-150 nm). Patients were then injected with modified tin colloid having a median particle size of 100 nm. A clinical comparison was performed between conventional particle size or reduced particle size tin colloid and the SN biopsy success rate, the number of SNs, and the colloidal uptake in SNs. RESULTS: A total of 118 patients were injected with the conventional tin colloid (group I) and 124 patients with the smaller particle colloid (group II). The identification rate and the number of SN in both groups were almost equal, and the patients with low-uptake SNs were not significantly less in group I(p = 0.55). However, in the subgroup of patients 60 years of age or more, group II had significantly more SNs than group I(1.4 vs 1.9; p = 0.03) and low-uptake SNs were significantly less common than in group I(p = 0.02). CONCLUSIONS: The improvement of colloidal uptake in SNs using the smaller particle size tin colloid was confirmed, and this impact was statistically significant in the older population.
BACKGROUND: Because sentinel node (SN) biopsy (SNB) is known to produce false-negative results, we examined the usefulness of axillary ultrasound (AUS) in selecting patients suitable for optimal SNB. METHODS: A positive AUS finding (positive AUS) was defined as an echo pattern of a homogeneously hypoechoic SN without an echo-rich center, indicating massive to extensive nodal involvement. The identification of SNs was performed, and complete axillary dissection was carried out. RESULTS: A total of 262 women were enrolled into the study (T1 disease = 94; T2 disease = 145; and T3 disease = 23). The incidence of positive AUS increased with increasing size of breast tumor (P <0.0001). The overall identification and false-negative rates were 88.2% and 10.8%, respectively. However, when limited to AUS-negative patients, SNs were identified in 205 of 208 patients (98.6%), and the false-negative rate was 1.7%. CONCLUSIONS: AUS should be included in the preoperative procedure for the selection of breast cancer patients suitable for SNB.
It has been found that in general 10 MV X-ray dose calculation can be made accurately for multi-leaf collimator irregular fields by using the total scatter factor (S(cp)), collimator scatter factor (S(c)), and phantom scatter factor (S(p)) proposed by Khan et al. With respect to the collimator scatter factor (S(c)), we used the field-mapping method of Kim et al. to obtain equivalent square fields of irregular fields (the collimator reverse effect can be accurately dissolved using the field-mapping method). Even for extremely small multi-leaf fields compared with the main collimator opening, X-ray output calculations could be made accurately by introducing the small segment correction (SSC) factor. With respect to the phantom scatter factor (S(p)), highly accurate calculations could be made for irregular field irradiation by applying an F(MLC) (MLC radiation leakage) factor to the equivalent square field (in cases in which the ratio of the multi-leaf equivalent square field side to the main collimator equivalent square field side is less than 0.6). However, it has been found that highly accurate dose calculations can, in general, be performed when the main collimator is limited just at the opening determined by the multi-leaf collimator field.
Calculation of in-air or in-water dose for 4 MV X-ray irregular fields could be accurately performed using the collimator scatter factor (S(c)) and phantom scatter factor (S(p)) concepts. It has been revealed that the equivalent square field for a multi-leaf collimator (MLC) irregular field can be evaluated accurately by using the S(p)-Clarkson or S(c)-Clarkson integration method; however, the S(c)-Clarkson integration method is more straightforward because the S(c) factor expresses the in-air X-ray output factor. It has been found that when the MLC field is relatively much smaller than the main collimator field, the Sc factor can be accurately evaluated by introducing the small segment correction (SSC) factor (except for the case in which the MLC field is less than 1 x 1 cm(2)). It has also been found that both the S(p) factor and the tissue-phantom ratio (TPR) can be precisely evaluated by introducing the F(MLC) factor in cases in which the ratio of the MLC equivalent square field side to the main collimator equivalent square field side is less than about 0.7.
It is difficult for male patients with spinal cord injury (SCI) to have children because of an ejaculation and dysfunction of spermatogenesis. However, owing to progress of assisted reproduction technology in recent years, it has become possible to have children even if the male has SCI, and the rate of success is improving gradually. During the 8 years from 1994 to 2002, infertility treatment was performed on 16 male patients with SCI consulting our hospital for acquistion of a child. We extracted their sperm by electroejaculation (EE) or testicular excision sperm extraction (TESE), and the sperm was artificially inseminated by the techniques such as artificial insemination with husband's semen (AIH), in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI). Consequently, it was successful in 14 pregnancies on 10 couples, and resulted in 11 healthy live births on 7 couples. Four cases resulted in abortion. Two spouses are pregnant at present. There were no remarkable differences between the success group and the failure group in the quality of sperm such as concentration and motility. The mean age of the spouses who became pregnant was slightly lower than that of those who did not. Assisted reproduction techniques as EE and ICSI were useful techniques for patients with SCI wishing to have children.
SN biopsy (SNB) has evolved rapidly during the past decade and has now become a standard of surgical care for patients with breast cancer. The primary purpose of SNB is to minimize patient morbidity from axillary staging, but SNB also presents research opportunities to further understand the role of the sentinel node in the natural history of breast cancer. We have attempted to highlight several issues regarding SN and its biopsy in this review, including:(1) Investigation of the optimal particle size for radiotracers. The success of SNB is, in large part, attributed to the particle size of radiolabeled tracers. Electron microscopy demonstrated significant accumulation of the tracer (tin colloid) in harvested SN, of which particle sizes were in the range of 100-150 nm. Therefore, this appeared to be a suitable particle size for SN identification. (2) Invention of a new gamma probe. A cord-and boxless handheld gamma probe was invented, which was more sensitive to radioactivity and involved a background subtraction function based on defined criteria. (3) Characterization of the immunologic response against tumor antigens. Fluorescence-activated cell sorting (FACS) analyses were performed to determine the phenotypic characteristics of B cells and T cells in SN. They revealed an increase in B cells expressing co-stimulated molecules as antigen-presenting cells in SN, compared with non-SN. With respect to T cells, a heterogeneous pattern of naive and memory T cells (TCM) was demonstrated in SN, in contrast to homogeneous pattern with TCM in non-SN. These results may support the concept that B cells play a significant role in antigen presentation required for T cell activation. Studies are currently in progress to test these possibilities.
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[reaction: see text] A fused four-membered ring has a powerful directing ability in effecting the regioselective reactions of benzyne with ketene silyl acetal, nucleophile, and alpha-alkoxyfuran.