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S Ohsumi

Publications and source records attributed to S Ohsumi.

At least 19 recordsLinked to original sources
PubMed2001

Improvement on in vitro maturation, fertilization and development of minke whale (Balaenoptera acutorostrata) oocytes.

The aims of the present study were to improve in vitro maturation, fertilization and subsequent development of minke whale oocytes. We investigated the effects of different concentrations (0, 10 and 20%) of fetal whale serum (FWS) in maturation medium on nuclear maturation, morphological grade (A or B) of cumulus-oocyte complexes (COC) obtained from prepubertal and adult minke whales. Grade A (> or = 5 layers of cumulus cells) COC collected from the adult whales and cultured in the medium with 20% FWS had a higher (P < 0.05) maturation rate (31.8%) than those in the medium without FWS (0%). Adding FWS to the maturation medium significantly (P < 0.01) improved the proportion of oocytes at Metaphase II (M-II): without FWS (7.9%), with 10% (19.4%) and 20% (21.4%) FWS. However, sexual maturity of whales and COC grades were not significantly affected by M-II oocytes. When in vitro fertilization of matured oocytes was performed in the presence of 20% FWS or 0.6% BSA in the fertilization medium, the proportions of sperm penetration and two-pronuclei formation in matured oocytes were not significantly different. Grade A COC cultured in a culture medium supplemented with 10% FWS cleaved at a higher rate (15.4%, P < 0.05) than did Grade A and B COCs cultured in the medium without FWS (0%). Neither Grade A nor B COCs cleaved when the medium was without FWS. The proportions of cleaved oocytes increased (P < 0.05) with FWS supplementation (6.9% and 8.1% for 1.0% FWS and 20% FWS, respectively). Grade A COC was significantly (P < 0.05) superior in its ability to cleave (14.5%) and develop to morula (4.2%) compared with that of the oocytes from Grade B COC (2.5% and 0%). Coculture with granulosa cells during in vitro culture did not significantly affect cleavage and development to the morula stage. These results indicate that FWS addition in the maturation medium improved the rate of in vitro maturation and cleavage after insemination of minke whale oocytes. The BSA supplementation in fertilization medium was as effective as FWS supplementation for in vitro fertilization of matured oocytes. In vitro embryo production beyond the morula stage of minke whale oocytes could be possible, if Grade A COC was selected and cultured in the maturation medium supplemented with 10% or 20% FWS.

Animals↗
PubMed2001

Plasma and pituitary concentrations of gonadotropins (FSH and LH) in minke whales (Balaenoptera acutorostrata) during the feeding season.

This study investigated plasma and pituitary concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and steroid hormones (progesterone: P4, testosterone:T, estradiol-17beta: E2) by enzyme-immunoassay (EIA) in minke whales (Balaenoptera acutorostrata) captured during the feeding season (December to March) in the Antarctic Ocean. Plasma FSH and LH levels in female minke whales were higher (P <0.05) than in male whales. Although the pituitary weight was not significantly different between male and female whales, pituitary FSH and LH levels were higher in females than in males (P<0.01) and mature whales than immature whales (P<0.05). Plasma levels of FSH, T and E2 were not significantly different between immature and mature male whales, but plasma LH and pituitary FSH and LH levels were higher (P<0.05) in mature than in immature whales. In both immature and mature whales regardless of gender, pituitary FSH and LH levels were correlated significantly (r=0.69: P<0.01). In mature male whales, plasma T and E2 levels (r=0.60: P<0.01), and testis weight and plasma T levels (r=0.46: P <0.05) were correlated. In immature female whales, plasma FSH and LH levels were highly correlated (r=0.68: P<0.001), but were not for mature female whales. The results show that gender and maturity influence gonadal and pituitary function of minke whales during the feeding season.

Age Factors↗
PubMed2001

Two cases of cholesterol granuloma of the breast.

We report two cases of cholesterol granuloma of the breast clinically diagnosed as malignant and describe the features. The first patient was a 74-year-old woman who complained of a lump in the left breast. The mammography and ultrasonography suggested a malignant mass. Fine needle aspiration showed multinucleated giant cells. We suspected breast cancer, but cholesterol granuloma was diagnosed on excisional biopsy. The second case was a 51-year-old woman who was found to have a breast tumor on a screening mammography. The mammography and ultrasonography suggested carcinoma, but excisional biopsy revealed cholesterol granuloma. Reports of cholesterol granuloma of the breast are very rare. Cholesterol granuloma should be considered in the differential diagnosis of breast carcinoma.

Aged↗
PubMed2001

An attempt at intracytoplasmic sperm injection of frozen-thawed minke whale (Balaenoptera bonaerensis) oocytes.

Little is known about the characteristics of fertilisation events in minke whales. Cryopreserved minke whale oocytes and spermatozoa do not fertilise in a standard IVF. This study was conducted to investigate the pronucleus formation ability of cryopreserved minke whale oocytes and their subsequent development following intracytoplasmic sperm injection (ICSI). In experiment 1, frozen-thawed minke whale immature oocytes were cultured for in vitro maturation (IVM) in a maturation medium (TCM199) supplemented with either porcine follicle stimulating hormone (pFSH)/estradiol-17beta (E2) or pregnant mare's serum gonadotropin (PMSG)/human chorionic gonadotropin (hCG). After 120 h of IVM, oocyte survival was examined before ICSI, and showed no significant difference in morphological normality (24-36%) between the two IVM media. Two-cell embryos (two oocytes from 21 sperm-injected oocytes) were obtained when the maturation medium was supplemented with pFSH/E2 or PMSG/hCG. In experiment 2, cryopreserved maturing oocytes were investigated for the effects of repeat-culture (2 h or 24 h) on survival before ICSI. Pronuclear formation and development were examined for the effects of sperm pretreatment with dithiothreitol (DTT) and oocyte activation with ethanol at ICSI. A frequency of 49-69% of frozen-thawed maturing oocytes was used for ICSI. Although oocyte activation did not produce a significant difference in survival, pronucleus formation and embryonic development, 2- and 4-cell cleaved oocytes were observed after injection of sperm pretreated with DTT.

Animals↗
PubMed2001

Breast biopsy for mammographically detected non-palpable lesions using a vacuum-assisted biopsy device (Mammotome) and an upright-type stereotactic mammography unit.

BACKGROUND: It is planned to start screening mammography throughout Japan in the near future. However, a minimally invasive biopsy procedure for mammographically detected non-palpable breast lesions is not available in almost all Japanese hospitals. It is crucial to develop a useful minimally invasive biopsy method which can be applied without difficulty. METHODS: Eighty-nine biopsies for 88 mammographically detected non-palpable breast lesions, consisting of 70 lesions with microcalcifications alone, eight masses without calcifications and 10 with both masses and microcalcifications, were performed using the combination of a vacuum-assisted biopsy device (Mammotome) and an upright-type stereotactic mammography unit. RESULTS: Microcalcifications were confirmed radiographically in the tissue obtained from 78 biopsies among 81 biopsies for the lesions with microcalcifications (96.3%). All the lesions without calcifications were considered to be biopsied successfully. Five patients complained of nausea or fainted during the localization or biopsy procedure and an additional patient suffered from hyperventilation syndrome. Five cases experienced mild subcutaneous bleeding in the breasts. CONCLUSIONS: The biopsy technique using the combination of a vacuum-assisted biopsy device and an upright-type stereotactic mammography unit is a cost-effective, safe and very useful method for mammographically detected non-palpable breast lesions. It is expected to be a standard method of biopsy for such lesions in many developed countries other than the USA. However, it is important to make the patients relaxed during the biopsy to prevent mental strain.

Adult↗
PubMed2000

Bronchiolitis obliterans organizing pneumonia syndrome in breast-conserving therapy for early breast cancer: radiation-induced lung toxicity.

PURPOSE: Breast-conserving surgery and postoperative radiotherapy have played important roles in the treatment of early breast cancer. Bronchiolitis obliterans organizing pneumonia (BOOP) syndrome has recently been reported to be one of the complications of adjuvant radiotherapy. The purpose of this study was to determine the incidence of and risk factors for BOOP syndrome in breast cancer patients. METHODS AND MATERIALS: Between January 1996 and December 1998, 157 patients with breast cancer underwent radiotherapy after breast-conserving surgery. The criteria used for the diagnosis of BOOP syndrome were as follows: 1) radiation therapy to the breast within 12 months, 2) general and/or respiratory symptoms lasting for at least 2 weeks, 3) radiographic lung infiltrates outside the radiation port, and 4) no evidence of a specific cause. RESULTS: BOOP syndrome developed in 4 (2.5%) patients, who had fever and nonproductive cough, with patchy infiltrative shadows on chest roentgenograms which emerged between 5 and 6 months after radiotherapy. The symptoms and pulmonary infiltrates were rapidly improved by treatment with prednisone (40 mg/day), which was tapered over 2- to 5-month periods. However, BOOP syndrome relapsed in all cases during the tapering period or after withdrawal of prednisone. The eosinophil and neutrophil counts were increased and the ratios of CD4+ to CD8+ lymphocytes were elevated in bronchoalveolar lavage fluid in all four cases. There were no differences in proportions of patients by age, irradiated breast site, use of tamoxifen and/or chemotherapy, or radiation dose between those with and without BOOP syndrome. CONCLUSIONS: BOOP syndrome is considered an intractable form of lung toxicity after radiotherapy to the breast. An immunologic reaction mediated by eosinophils, neutrophils, and lymphocytes may be responsible for the development of this syndrome. Methods of prevention of BOOP syndrome should be established.

Adult↗
PubMed2000

In vitro maturation and ultrastructural observation of cryopreserved minke whale (Balaenoptera acutorostrata) follicular oocytes.

Minke whale (Balaenoptera acutorostrata) follicular oocytes were cryopreserved by a slow-step freezing procedure using ethylene glycol. The morphologically viable proportion of postthawed minke whale follicular oocytes was 39.7%. The maturity of the animals (immature and mature whales) or the presence or absence of cumulus cells (CC) did not affect the proportion of morphologically viable oocytes. Postthawed oocytes were examined for nuclear status after in vitro maturation. The presence of CC (29.1%) significantly enhanced (P < 0.05) the proportion of oocytes at metaphase I/anaphase I/telophase I stages compared to results with the absence of CC (13.5%). A total of 4 of 194 postthawed oocytes matured to the second metaphase stage after culture for 5.5 days with or without CC. The cryopreserved immature oocytes obtained from immature and mature whales were processed to examine the ultrastructure by transmission electron microscopy. Varying ultrastructural damage to the cytoplasm was observed as a result of the cryopreservation procedures. These results show that 20-30% of cryopreserved minke whale follicular oocytes can resume meiosis in vitro, but damage induced by the freezing and thawing procedures was observed.

Animals↗
PubMed2000

Evaluation of the interobserver agreement in the number of mitotic figures of breast carcinoma as simulation of quality monitoring in the Japan National Surgical Adjuvant Study of Breast Cancer (NSAS-BC) protocol.

In the National Surgical Adjuvant Study for Breast Cancer (NSAS-BC), node-negative breast cancers were divided into higher- and lower-risk groups according to the histopathological nuclear grade given at individual collaborating hospitals, and the higher-risk group was entered into a randomized protocol of adjuvant therapy. Because the nuclear grade was the composite of nuclear atypia and mitotic counts, maintenance of interobserver agreement in mitotic counts was indispensable for the success of the protocol study. Fourteen pathologists participating in the protocol judged whether or not 20 photomicrographs suspected of showing mitotic cancer-cell figures truly showed mitoses. After standardizing the counting method, these pathologists counted the number of mitotic figures per 10 high-power fields of hematoxylin-eosin-stained main-tissue sections of 20 tumors. Areas where mitotic counts were considered to be the most frequent by each pathologist were compared for these tumors. For the judgment of whether the photomicrograph indicated mitosis, the level of interobserver agreement was moderate (kappa = 0.569). In the observations of 20 tumors, interobserver agreement level of mitotic counts was moderate (kappa = 0.506), that of nuclear atypia scoring was fair (kappa = 0.265), and that of nuclear grading was substantial (kappa = 0.633). The counted area was almost the same among the observers in 9 tumors, split into two areas in 6, and dispersed in 5. Concordance in judgment was achieved in 7 of the first 9 and in all of the third 5, but only in one of the second 6. The cause of discordance was mostly derived from tumor heterogeneity and the difference in the site where mitoses were counted. Interobserver agreement level was considered to be satisfactory, and it was expected that the case entry would be performed appropriately in the protocol study. The selection of the counting area was confirmed to be important for the acquisition of high-level agreement level in mitotic counts.

Breast Neoplasms↗
PubMed2000

[Cancer chemotherapy based on evidence--metastatic breast cancer].

Breast cancer is relatively sensitive to chemotherapy. However, although response rate to chemotherapy is reported to be from 50 to 70% in metastatic breast cancer, it is incurable. Current standard chemotherapeutic regimens do not provide a large survival benefit according to the evidence obtained from clinical studies. Before developing a treatment program, we should therefore realize that the aims of chemotherapy for metastatic breast cancer are improvement of quality of life through relief of symptoms, and prolonging survival.

Aged↗
PubMed1998

Breast-Concerving Surgery Following Preoperative Radiotherapy to the Primary Breast Cancer of 3 cm or Larger: Histological Analysis of Size Reduction of the Tumors by Radiotherapy.

Fifteen women with primary breast cancer of 3 cm or larger were treated by radiotherapy of 5000 or 5100 cGy preoperatively for breast conservation. Among them, three responded completely to radiotherapy clinically, 6 did partially, and 6 showed minor response. Breast-concerving surgery was performed in all cases. Histologically one patient did not have cancer cells at surgery, while eight showed good response but had residual tumor, and the rest responded moderately. The histological margins were positive in six cases, of those three were positive due to an invasive component. Calculation of the size reduction of the primary tumor by radiotherapy at a histological level revealed that the invasive area of the tumors was 79.5% on average. There was a tendency, among well responding patients, to show a large reduction in size. However, the tumor cells tended to remain in the peripheral areas of the originally invasive areas. In summary, preoperative radiotherapy made the size of the primary tumors smaller in the majority of the cases clinically but the actual histological size reduction was relatively small in general. We conclude that preoperative radiotherapy is effective to extend the indications of conservative treatment in patients with a large primary breast cancer. However, care is required when we treat patients with a very large primary breast cancer conservatively.

Journal Article↗
PubMed1997

Factors affecting in vitro maturation of minke whale (Balaenoptera acutorostrata) follicular oocytes.

Factors affecting in vitro maturation (IVM) of minke whale (Balaenopetra acutorostrata) follicular oocytes were investigated. In experiment 1, recovery rates for oocytes from follicles of different sizes (small, 1-5 mm; medium, 6-10 mm; large, > or = 11 mm) were similar in both immature (54.7%) and mature (53.5%) females, and the follicular sizes did not affect recovery rate. Approximately half the oocytes recovered from small follicles in immature (55.5%) and mature (52.1%) whales were surrounded by at least a few layers of cumulus cells. Before culture, 71.7% and 61.2% of oocytes from immature and mature whales, respectively, were at the germinal vesicle stage. For IVM, effects of serum type, hormones, and additional cumulus cells (experiment 2) and effects of culture durations (24-120 h, experiment 3) were investigated. The three factors investigated in experiment 2 did not affect maturation rates. TCM199 supplemented with fetal whale serum, hormones, and additional cumulus cells showed the highest rate (21.6%) of matured oocytes and resulted in a significant difference from the rate in medium with only fetal calf serum added (6.6%). The first oocyte with an extruded polar body was observed after 84 h of culture. The maximum rate (27.3%) of matured oocytes was obtained by 96 h of culture, but there was no significant difference in the proportions of matured oocytes between 90 and 120 h in culture. These results indicate that in vitro nuclear maturation of immature follicular oocytes in minke whales can be induced.

Animals↗
PubMed1997

[Granisetron versus granisetron plus methylprednisolone in the prevention of chemotherapy induced nausea and vomiting--in adjuvant chemotherapy, including CDDP against gastric cancer].

CDDP is one of the most effective drugs in chemotherapy for gastric cancer. We compared the antiemetic effect of a combination of granisetron and methylprednisolone with that of granisetron administered alone. Twenty postgastrectomy-patients who were to receive moderately emetogenic chemotherapy, including CDDP, were enrolled in randomized fashion to evaluate the efficacy and toxicity of two antiemetic regimens. The following antiemetic regimens were used: 3 mg of granisetron given intravenously before chemotherapy (11 patients) or a combination of granisetron and 250 mg of methylprednisolone in the same manner (9 patients). Granisetron combined with methylprednisolone tender to be more effective than granisetron alone. The adverse effects were very mild. Their efficacy against delayed emesis is still not entirely satisfactory.

Antiemetics↗
PubMed1996

Invasive Ductal Carcinoma of the Nipple: A Case Report.

We report a very rare case of breast carcinoma which possibly arose from the duct of the nipple and formed a nipple mass. A 71-year-old woman presented with an elastically hard and enlarged right nipple, 3.5x 2.8 cm in size. Mammograms and ultrasonograms suggested a benign tumor of the nipple, but histological examination revealed invasive ductal carcinoma. No Paget's cells were found in the epidermis. Modified radical mastectomy was performed. Both estrogen and progesterone receptors were positive. One of the nine axillary nodes dissected had metastatic foci. To our knowledge, this case is only the second reported case of invasive ductal carcinoma originating from the nipple. Differential diagnosis and histogenesis are discussed.

Journal Article↗
PubMed1996

Analysis of local recurrences after breast conserving therapy using postoperative radiotherapy.

One hundred and ninety-one breast cancer patients had breast conserving therapy (lumpectomy and postoperative radiotherapy) at the Shikoku Cancer Center Hospital between July 1989 and December 1994. Seven patients developed recurrence, two of them experienced recurrence in the treated breast after a median follow-up of 27 months. One of the two patients with the local recurrence had an inflammatory cancer-like change in the treated breast which consisted of a diffuse induration in the breast and thick overlying skin with redness. It was very difficult to distinguish local recurrence from the local change due to radiation. Her primary tumor showed prominent lymphatic vessel involvement, although the surgical margins were negative histologically. We believe that the possible lymphatic retention after axillary dissection facilitated this type of progression of the residual tumor cells within the lymphatic vessels. Although this type of local recurrence is quite rare, it could cause distant metastases. Reanalysis of surgical treatment and postoperative adjuvant therapy for the patients with breast cancer showing prominent lymphatic vessel involvement is required.

Adult↗
PubMed1994

Mechanistic studies on depurination and apurinic site chain breakage in oligodeoxyribonucleotides.

Products formed from defined oligodeoxyribonucleotide tetramers (oligonucleotides) by depurination at pH 5.0 and 90 degrees C followed by chain breakage at the resulting apurinic sites (AP sites) were assigned by reversed phase HPLC. Through kinetic analysis, rate constants of depurination and subsequent chain breakage reactions were measured. Depurination of the oligonucleotides with purine bases locating at the terminal positions was several times faster than those with purines at the internal ones. The pKa values for the N7 of the G residues and the activation energies of the depurination were essentially independent of the position of the bases. The frequency factor was found to be responsible for the observed difference of the depurination rates. In contrast, the chain breakage by beta-elimination was several times faster for the AP sites formed at the internal positions than those at the 5'-terminal positions. It is suggested that an electron withdrawing phosphate group attached to the 5'-side of an AP site facilitates the chain cleavage.

Apurinic Acid↗
PubMed1993

Loop-like structure of dGTTG in solution.

A strong NOESY cross peak was observed between G1H8 and G4H8 for a single-stranded tetradeoxyoligonucleotide dGTTG in aqueous solution. If dGTTG is in an expanded form, NOE should not be observed because the distance between G1H8 and G4H8 is estimated to be about 13 A. This NOESY cross peak shows that the guanine residues of the both ends of dGTTG exist with short distance (< 5 A), and that dGTTG has a distorted loop-like structure in aqueous solution. This is the shortest single-stranded oligodeoxynucleotide that has a rigid structure in solution.

Magnetic Resonance Spectroscopy↗
PubMed1992

Monomer-dimer equilibrium of nitroso-aromatic spin trap 3,5-dibromo-4-nitrosobenzenesulfonic acid, sodium salt (DBNBS), in aqueous solution.

3,5-Dibromo-4-nitrosobenzenesulfonic acid, sodium salt (DBNBS), which is widely used as a spin trap in biological systems, was allowed to form the monomer-dimer equilibrium in aqueous solution, and its equilibrium constant (Kc) was determined by NMR measurement and visible spectrum analysis. The Kc values obtained from the two different methods were virtually identical and evaluated as 1.3 x 10(-3) mol dm-3 at 25 degrees C. Further, the molar extinction coefficient of DBNBS monomer (epsilon 760) was determined to be 34 dm3mol-1cm-1. The present results indicate that only a minor portion (ca. 20%) of dissolved DBNBS (10 mmol dm-3) is practically capable of spin trapping under the conditions most widely used in biological studies.

Benzenesulfonates↗