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Biomedical subjects

T Sakurai

Publications and source records attributed to T Sakurai.

At least 145 records · Page 8Linked to original sources
PubMed2000

Paclitaxel-induced remission in docetaxel-refractory anthracycline-pretreated metastatic breast cancer.

Paclitaxel and docetaxel are excellent agents with a high antitumor effect for the treatment of previously anthracycline-exposed metastatic breast cancer. There has been no standard treatment for patients who undergo therapy of a taxan-resistant metastatic breast cancer. Paclitaxel has partial non-cross-resistance in vitro with docetaxel in inhibiting microtubule disaggregation. We present the case of a patient with docetaxel-refractory anthracycline-pretreated metastatic breast cancer who achieved remission with paclitaxel.

Adult↗
PubMed2000

Swimming training prevents generation of suppressor macrophages during acute cold stress.

PURPOSE: Acute cold stress induces suppressor macrophages expressing large numbers of receptors to Fc portion of immunoglobulin G (MAC-1+ Fc gammaRII/IIIbright cells), resulting in suppression of splenocyte mitogenesis. The generation of MAC-1+ Fc gammaRII/IIIbright cells is partly mediated by increased glucocorticoid levels during acute cold stress. The aim of the current study was to investigate the effect of swimming training on the generation of the MAC-1+ Fc gammaRII/IIIbright suppressor macrophages by acute cold stress. METHODS: The trained mice underwent a 6-wk endurance swimming training (5 times/wk) in water at 35-36 degrees C for 90 min. The swimming training significantly increased brown adipose tissue mass, suggesting improved cold tolerance. Actually, when the swimming-trained mice were exposed to 5 degrees C for 3 h (acute cold stress), the rectal temperature was not decreased. The proportion of MAC-1+ Fc gammaRII/IIIbright cells in peritoneal exudate cells from swimming-trained mice was significantly lower than that from control mice. In addition, the proportion of MAC-1+ Fc gammaRII/IIIbright cells in peritoneal exudate cell population from swimming-trained mice was unaffected by the acute cold stress. The swimming training significantly attenuated the increases in serum corticosterone levels in response to acute cold stress. These results suggested that swimming training not only improves cold tolerance but also inhibits the generation of suppressor macrophages under acute cold stress as well as under normal conditions.

Acclimatization↗
PubMed2000

Phlebosclerotic colitis: value of radiography in diagnosis--report of three cases.

Three cases sharing the following radiologic features are reported: (a) abdominal conventional radiography-vascular calcifications at the right hemicolon, (b) abdominal computed tomography-colonic wall thickening and venous calcifications, and (c) barium enema examination-luminal narrowing of the right hemicolon and thumbprinting. There were no clinical or laboratory findings suggestive of portal hypertension. The disease entity, "phlebosclerotic colitis," should be differentiated from ordinary ischemic colitis.

Abdomen, Acute↗
PubMed2000

Exocytosis and movement of zymogen granules observed by VEC-DIC microscopy in the pancreatic tissue en bloc.

The dynamic aspects of exocytosis, especially in the normal acinar tissue en bloc, have remained unclear. We visualized exocytosis directly in the tissue of the exocrine pancreas of rodents by video-enhanced contrast-differential interference contrast (VEC-DIC) microscopy to investigate various exocytosis-related rates and the relationship between the movement of granules and exocytotic responses. Stimulation of the tissue with bethanechol or cholecystokinin caused many of the zymogen granules in the apical pole to disappear abruptly. The exocytotic transients of individual granules were completed in 0.48-0.65 s. Granules destined to participate in the exocytotic response moved randomly at velocities of approximately 0.06 microm/s or less during stimulation. In the tissue preparation, granules located far from the apical pole frequently moved back and forth for 1-7 microm without showing exocytosis. Colchicine suppressed this movement and the late phase of the secretory response. Real-time (VEC-DIC) observation of granule dynamics revealed that the initial step of exocytosis was not coupled directly with the microtubule-dependent translocation but with a continuous, slow Brownian fluctuation of granules.

Animals↗
PubMed2000

Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats 11). Testicular toxicity of 2- or 4-week repeated or single-dose administration of a novel platinum complex.

A novel platinum complex, compound C, developed as an antitumor agent, was intravenously administered at 10 mg/kg/day to 6-week-old and 8-week-old rats. After 4 weeks of administration to the former, testicular enlargement was observed at a similar incidence as testicular atrophy and dilatation or atrophy of the seminiferous tubules was observed. Degeneration/necrosis of the seminiferous epithelium, decrease of seminiferous epithelium, formation of multinucleated giant cells, and vacuolar degeneration of Sertoli cells were also seen. These lesions were more marked in seminiferous tubules with atrophy than in those without atrophy. After 2-week administration to 8-week-old rats, slight initial-phase findings such as dilatation of seminiferous tubules and degeneration/necrosis of the seminiferous epithelium were noted in all rats. In rats administered 20 mg/kg/day, for which the administration period was shortened to 1 week due to marked weight loss, very slight initial lesions were similarly observed. However, these lesions were not easy to detect in these rats. Following single administration of a sublethal dose (80 mg/kg), testicular lesions were clearly observed 14 days after administration, but the incidence and grade of lesions were very low at 7 days. In conclusion, testicular toxicity of compound C can be clearly detected after 2-week administration, although the progression of lesions differed from the case with 4-week administration.

Animals↗
PubMed2000

Rheumatoid arthritis accompanied by colonic lesions.

A 69-year-old woman with a 6-year history of rheumatoid arthritis treated solely with an orally administered NSAID had slowly progressing persistent mild abdominal pain and diarrhea, accompanied with marked sing of inflammation as well as hypoproteinemia due to protein-losing gastroenteropathy. Examinations of the large intestine revealed variously shaped ulcerative lesions, centered around the left hemicolon, as well as luminal narrowing. The course of the disease and the shape of the lesions strongly suggested involvement of rheumatoid vasculitis; oral administration of prednisolone was effective.

Aged↗
PubMed2000

The effects of prenatal X-irradiation on hypoglossal nucleus: a GFAP immunohistochemical study.

The effects of prenatal X-irradiation on hypoglossal (XII) nucleus were investigated in the rat. Pregnant animals were exposed to a single whole body X-irradiation on day 11 and 16 of gestation at a does of 1.3 Gy. The offspring were killed at 7-14 days of age for the histological and immunohistochemical observations. Nissl staining revealed no significant changes of XII motoneurons in these experimental animals. In the control case it was of interest that expression of glial fibrillary acidic protein-immunoreactivity (GFAP-IR) is largely confined to the dorsomedial region including the XII nucleus at the level caudal to the obex. Exposure of X-irradiation on day 16 of gestation led to similar expression of GFAP-IR in the nucleus at the same level. However, exposure on day 11 of gestation apparently led to strong expression of GFAP-IR in the XII nucleus at the level caudal to the obex and the expression was observed to extend rostrally. The GFAP-IR cells showed hypertrophy of cell bodies and longer cytoplasmic processes. Horse-radish peroxidase (HRP) injection into the tip of the tongue including the intrinsic muscles resulted in retrograde labeling in the ventromedial portion of the XII nucleus bilaterally from +0.30 to -1.25 mm. The present study would indicate that motoneurons of the XII nucleus supplying mainly the intrinsic and partly the extrinsic tongue muscles are more sensitive to X-ray exposure before the formation of the XII nucleus.

Animals↗
PubMed2000

[Exogenous lactate sustains synaptic activity and neuronal viability, but fails to induce long-term potentiation (LTP)].

In Alzheimer's disease, brain glucose metabolic ratio decreases, whereas the brain lactate metabolic ratio increases. To investigate possible synaptic dysfunction in Alzheimer's disease, we examined the effects of exogenous glucose deprivation and replacement of glucose with lactate on the synaptic transmission, synaptic plasticity, and the morphological integrity of hippocampal neurons. Synaptic activity was estimated by the amplitude of the population spike (PS) recorded in the granular cell layer in the hippocampal slices from guinea pig and rat. Exogenous glucose deprivation caused the immediate depression of PS. Replacement of glucose with lactate induced transient decrease of PS, followed by spontaneous recovery of synaptic transmission. Neural activity recovered from transient glucose deprivation became resistant to the replacement of glucose with exogenous lactate. Glucose-supported synaptic transmission exhibited approximately 140% enhancement of PS (LTP). However, lactate-supported synaptic activity yielded approximately 110% potentiation of PS. Effects of exogenous glucose and lactate on the cell viability were examined by the propidum iodide uptake and LDH release in the organotypic hippocampal slice cultures. Hippocampal slice cultures incubated in medium containing 10 mM lactate suppressed the cell death during 48 h observation as well as those in the 10-30 mM glucose containing medium. These results indicate that lactate can sustain the neural transmission and support the morphological integrity of hippocampal neurons, but failed to induce LTP, which could at least in part, cause the memory impairment in Alzheimer's disease.

Animals↗
PubMed2000

Regression of a presumed meningioma with the antiestrogen agent mepitiostane. Case report.

This 68-year-old woman underwent a distal gastrectomy for gastric cancer in August 1994. A presumed meningioma of the falx was found incidentally on a staging examination of the gastric cancer, but the meningioma was not treated with surgery. Instead, after gastrectomy the patient received tegafur as adjuvant chemotherapy until February 1996, when she was readmitted to the hospital because of loss of appetite and emaciation but with no recurrence of the gastric cancer. A computerized tomography scan obtained during this second admission showed no change in the meningioma. To improve her general condition, tegafur was discontinued and she was started on a course of the antiestrogen agent mepitiostane. Administration of mepitiostane for approximately 2 years resulted in a marked regression (73%) of the meningioma. This is the first reported case of a presumed meningioma that regressed as a result of use of the antiestrogen agent mepitiostane.

Adenocarcinoma, Papillary↗
PubMed2000

[Efficacy of docetaxel for recurrent breast cancer: evaluation based on chemosensitivity test and clinical response].

We investigated the chemosensitivity of anticancer agents against primary (230 patients, 268 tumors) and recurrent breast cancer (40 patients, 51 tumors) using histoculture drug response assays (HDRA) of surgical specimens. Of the 40 recurrent breast cancer patients, 26 were pretreated with anthracycline. The efficacy of the agents was assessed according to an inhibition index of optical density detected by an ELISA reader. The inhibition rate of docetaxel against recurrent tumors was similar that against primary ones, although the rates of adriamycin, 5 fluorouracil, mitomycin and cisplatin against recurrent tumors were significantly lower than those against primary ones. The clinical response of docetaxel was also evaluated in ten patients with recurrent breast cancer. Of the ten patients with recurrent breast cancer, eight were pretreated with anthracycline, and seven showed a partial response. These results indicate that docetaxel is effective against recurrent breast cancer, even anthracycline-resistant breast cancer.

Antineoplastic Agents, Phytogenic↗
PubMed2000

[Pain relief with alendronate therapy in a breast cancer patient with bone metastasis].

A 66-year-old woman developed a bone metastasis from breast cancer to the sternum in September, 1997. She received alendronate therapy, consisting of biweekly intravenous administrations of 10 mg-alendronate 6 times and monthly 20 mg-alendronate infusions 15 times. The first alendronate administration markedly alleviated her bone pain. She obtained complete pain relief after the 4th alendronate infusion. However, an elevation of tumor marker levels in serum without any pain increase forced us to treat her with medroxyprogesterone acetate and doxifluridine in addition to the alendronate therapy. With these therapies, she has shown an objective response (PR) of the bone metastasis for 8 months. In conclusion, alendronate therapy was effective against bone pain due to metastasis of breast cancer.

Aged↗
PubMed2000

[Histoculture drug response assay on non-small cell lung cancer].

We examined the chemosensitivity of non-small cell lung cancer (NSCLC) tissues to CDDP, 5-FU, ADM, MMC, ETP and SN38 using histoculture drug response assay (HDRA). One-hundred and thirty surgical specimens from NSCLC patients who were not given preoperative chemotherapy were used. The inhibition indexes of CDDP, 5-FU, MMC, ADM, ETP and SN38 were 39.1 +/- 18.2%, 48.0 +/- 19.7%, 63.3 +/- 17.7%, 47.6 +/- 22.0%, 36.9 +/- 21.1%, and 37.9 +/- 25.2%, respectively. Inhibition indexes were above the cutoff level, i.e., 'judged sensitive,' in 40 cases (31.3%) for CDDP, 34 cases (27.4%) for 5-FU, 54 cases (44.3%) for MMC, 36 cases (33.0%) for ADM, 29 cases (29.8%) for ETP, and 34 cases (37.4%) for SN38, respectively. In almost one-third of patients, the inhibition indexes of all drugs were under cutoff levels. Correlations between in vitro chemosensitivity data and patient responses to chemotherapy were obtained from 16 evaluable patients, and a 44.4% true positive rate and a 100% true negative rate were observed. Our results with HDRA for NSCLC showed a high incidence of intrinsic multidrug resistance. HDRA may help doctors to avoid non-effective chemotherapy for NSCLC patients.

Adenocarcinoma↗
PubMed2000

[Sjögren's syndrome with malignant lymphoma, interstitial pneumonia, and pulmonary hypertension].

A 62-year-old woman was admitted to our hospital for further examination of cough and dyspnea on exertion. She had suffered xerostomia and xerophthalmia for 7 years. Physical examinations showed purpura on the lower extremities, Raynaud's phenomenon, and swelling of the parotid glands. Laboratory data disclosed thrombocytopenia, hypergammaglobulinemia, and high titers of anti-nuclear antibody, anti SS-A, and anti SS-B antibodies. Sicca symptoms, a positive Schirmer's tear test, and laboratory findings together yielded a diagnosis of Sjögren's syndrome. Chest X-P and computed tomographic films demonstrated diffuse reticulonodular shadows and multiple nodules in the left lower lung. Echocardiography and right cardiac catheterization revealed enlargement of the right ventricle, tricuspid regurgitation, and elevated pulmonary arterial pressure. Histologic findings from an open-lung biopsy specimen revealed accumulation of inflammatory cells and fibrosis around broncho-vascular bundles, and diffuse large cell lymphoma. Despite a favorable response to chemotherapy, the patient died of right ventricular failure.

Female↗
PubMed2000

[Measles pneumonia presenting with multiple nodular opacities on chest radiographs].

A 22-year-old woman presented with fever, cough, and maculopapular erythematous rash on hands and feet. These symptoms developed 14 days after the onset of natural measles in the patient's daughter. Chest radiographs obtained on the first examination showed multiple nodular opacities and infiltrates in the left and right lung fields. Serological examinations disclosed elevated levels of the specific IgM antibody and a remarkably elevated hemagglutination inhibition (HI) titer, indicating a recent measles infection. The patient's symptoms, skin eruptions, and abnormal chest radiograph findings disappeared after several days. However, chest computed tomographic scans taken 8 months after the initial examination revealed small, residual nodular opacities. Other than the fact that the patient had received attenuated measles virus vaccine, these findings were typical of the clinical course for atypical pneumonia. We concluded that in the differential diagnosis of multiple nodular opacities on chest radiographs, adequate attention should be given to pulmonary involvement of measles infection.

Adult↗