Search PubMed⌕ Search

Biomedical subjects

T Sano

Publications and source records attributed to T Sano.

At least 109 records · Page 6Linked to original sources
PubMed2001

Fate of nascent microtubules organized at the M/G1 interface, as visualized by synchronized tobacco BY-2 cells stably expressing GFP-tubulin: time-sequence observations of the reorganization of cortical microtubules in living plant cells.

Transgenic BY-2 cells stably expressing a GFP (green fluorescent protein)-tubulin fusion protein (BY-GT16) were subcultured in a modified Linsmaier and Skoog medium. The BY-GT16 cells could be synchronized by aphidicolin and the dynamics of their microtubules (MTs) were monitored by the confocal laser scanning microscopy (CLSM). We have succeeded in investigating the mode of reorganization of cortical MTs at the M/G1 interface. The cortical MTs were initially organized in the perinuclear regions and then they elongated to reach the cell cortex, forming the bright spots there. Subsequently, the first cortical MTs rapidly elongated from the spots and they were oriented parallel to the long axis towards the distal end of the cells. Around the time when the tips of the parallel MTs reached the distal end, the formation of transverse cortical MTs followed in the cortex near the division site, as we had previously suggested [Hasezawa and Nagata (1991) Bot. Acta 104: 206, Nagata et al. (1994) Planta 193: 567]. It was confirmed in independent observations that the appearance of the parallel MTs was followed by the appearance of the transverse MTs in each cell. We found that the transverse MTs spread through the whole cell cortex within about 20-30 min, while the parallel MTs disappeared. The significance of these observations on the mode of cortical MT organization is discussed.

Cell Line↗
PubMed2001

Lymph node metastasis from hilar cholangiocarcinoma: audit of 110 patients who underwent regional and paraaortic node dissection.

OBJECTIVE: To assess the status of the regional and paraaortic lymph nodes in hilar cholangiocarcinoma and to clarify the efficacy of systematic extended lymphadenectomy. SUMMARY BACKGROUND DATA: There have been no studies in which regional and paraaortic lymphadenectomies for hilar cholangiocarcinoma have been routinely performed. Therefore, the metastasis rates to the regional and paraaortic nodes, the mode of lymphatic spread, and the effect of extended lymph node dissection on survival remain unknown. METHODS: This study involved 110 patients who underwent surgical resection for hilar cholangiocarcinoma with lymph node dissection including both the regional and paraaortic nodes. A total of 2,652 nodes retrieved from the surgical specimens were examined microscopically. RESULTS: Of the 110 patients, 52 (47.3%) had no involved nodes, 39 (35.5%) had regional lymph node metastases, and 19 (17.3%) had regional and paraaortic node metastases. The incidence of positive nodes was significantly higher in the patients with pT3 disease than in those with pT2 disease. The pericholedochal nodes were most commonly involved (42.7%), followed by the periportal nodes (30.9%), the common hepatic nodes (27.3%), and the posterior pancreaticoduodenal nodes (14.5%). The celiac and superior mesenteric nodes were rarely involved. The 3-year and 5-year survival rates were 55.4% and 30.5% for the 52 patients without involved nodes, 31.8% and 14.7% for the 39 patients with regional node metastases, and 12.3% and 12.3% for the 19 patients with paraaortic node metastases, respectively. Of the 19 patients with positive paraaortic nodes, 7 had no macroscopic evidence of paraaortic disease on intraoperative inspection. The survival in this group was significantly better than in the remaining 12 patients. CONCLUSION: The paraaortic nodes and the regional nodes are frequently involved in advanced hilar cholangiocarcinoma. Whether extended lymph node dissection provides a survival benefit requires further study. However, the fact that long-term survival is possible despite pN2 or pM1 disease encourages the authors to perform an aggressive surgical procedure with extended lymph node dissection in selected patients with hilar cholangiocarcinoma.

Aorta↗
PubMed2001

Accuracy of Digora system in detecting artificial peri-implant bone defects.

This study was done to compare the diagnostic accuracy in detecting simulated intrabony defects around fixtures using Digora (DIG; Sordex Orion Corporation, Helsinki, Finland) compared with Ektaspeed Plus film (PLS; Eastman Kodak Co., Rochester, NY). Three titanium implant fixtures were placed in molar areas of three cadavers. Bone defects were created in the interproximal alveolar crest. Exposure time was adjusted to a PLS film and reduced to 1/5 only for DIG (1/5 DIG). The results of four observers were assessed. Sensitivity, specificity, accuracy, and under the receiver operator characteristic curve (ROC) area were evaluated. Statistical analyses were performed by using Friedman test and one-way ANOVA test. Mean sensitivity/specificity were 0.60/0.85 (DIG), 0.54/0.81 (1/5 DIG), and 0.64/0.58 (PLS). There were no statistically significant differences in the diagnostic accuracies. Digora had an equivalent performance to radiographic film in detecting intrabony defects adjacent to the implants, notwithstanding the amount of 1/5 of the exposure time.

Alveolar Bone Loss↗
PubMed2001

Aberrant expression of pRb, p16, p14ARF, MDM2, p21 and p53 in squamous cell carcinomas of lung.

Expression of cell cycle regulatory proteins in both the RB and p53 pathways was investigated in 50 cases of squamous cell carcinoma (SCC) of the lung using immunohistochemical techniques. Abnormality of pRb and p16 expression was seen at the frequencies of 16% and 78%, respectively, and appeared to be in a reciprocal relationship. On the other hand, strong and diffuse p53 immunoreactivity was seen in 60% of SCCs. MDM2 and p14ARF expressions were each observed in about half of the cases of SCC and were not significantly associated with strong p53 immunoreactivity. Statistical analysis revealed that p14ARF expression was significantly correlated with both p16 and MDM2 expression. Moreover, strong p53 expression was not correlated with the expression of p21. In comparing clinicopathological status with the immunohistochemical results, lack of p16 immunoreactivity was observed in the elderly group (over 65 years) as compared with the younger group (less than 65 years). Strong p53 expression was frequently observed in higher stages of SCC, with the developing tumor located in the central field of the lung. Similarly, the frequency of p14ARF expression was high in centrally developed SCC, but low in SCC developed in the periphery. These results suggest that disruption of the RB and p53 pathways is a frequent event in SCC, and that abnormal expression of p16 and p53 plays a more critical role than that of pRB, p14ARF and MDM2 in the development of SCC of the lung.

Age Factors↗
PubMed2001

Temporomandibular joint disk displacement: comparison in asymptomatic volunteers and patients.

PURPOSE: To compare the prevalence and type of temporomandibular joint (TMJ) disk displacement in asymptomatic volunteers with those in patients. MATERIALS AND METHODS: Bilateral oblique sagittal and oblique coronal intermediate-weighted magnetic resonance (MR) images of the TMJs in 58 patients with pain and dysfunction were analyzed and compared with corresponding MR images of 62 asymptomatic volunteers. RESULTS: Forty-five (78%) of 58 patients had disk displacement compared with 22 (35%) of 62 asymptomatic volunteers. Complete disk displacement was found in 46 (40%) of 115 joints in patients compared with three (2.4%) of 124 joints in asymptomatic volunteers, whereas partial disk displacement occurred in 26 (22.6%) and 27 (21.8%) joints, respectively. Two types of complete disk displacement, anterolateral and anterior, occurred frequently in patients, seldom in volunteers. Only minor differences were found between other types of disk displacement when prevalence in patients was compared with that of volunteers. The disk reduced to a normal position on open-mouth images in all joints in the volunteers compared with 76% of the joints in patients. CONCLUSION: TMJ disk displacement was less prevalent and was of a different type in asymptomatic volunteers compared with patients with pain and dysfunction.

Adult↗
PubMed2001

Intramolecular capture of pummerer reaction intermediates by an aromatic nucleophile: selective construction of 1,4-benzothiazine and indole ring systems.

The simple alkyl sulfoxide 6 carrying two aromatic nucleophiles, when treated with trifluoroacetic anhydride at room temperature (Pummerer reaction conditions), underwent an intramolecular aromatic sulfenylation of the 6-exo-tet process in an exclusive manner to yield two regioisomeric 1,4-benzothiazine derivatives, 8 and 9. On the other hand, a similar reaction of the alpha-acyl sulfoxide 7, possessing identical aromatic nucleophiles, caused an intramolecular aromatic alkylation of the 5-exo-trig process to produce the 3-oxo-indole derivative 14 in a quantitative yield. These results demonstrate that the construction of 1,4-benzothiazine and indole ring systems can be achieved in a selective manner by proper choice of the sulfoxide side chain.

Acetic Anhydrides↗
PubMed2001

A synthesis of 3-phenyl-1,2,3,4-tetrahydroisoquinoline and 2-phenyl-1,2,4,5-tetrahydro-3H-3-benzazepine via Pummerer-type cyclization: enhancing effect of boron trifluoride diethyl etherate on the cyclization.

A synthesis of 6,7-dimethoxy-3-phenyl-1,2,3,4-tetrahydroisoquinoline (14a) and 7,8-dimethoxy-2-phenyl-1,2,4,5-tetrahydro-3H-3-benzazepine (14b) was achieved via the cyclization of N-(3,4-dimethoxyphenyl)methyl-1-phenyl-2-(phenylsulfinyl)ethylformamide (6a) and N-2-(3,4-dimethoxyphenyl)ethyl-1-phenyl-2-(phenylsulfinyl)-ethylformamide (6b) using the Pummerer reaction as a key step, respectively. The Pummerer reaction of 6a,b under usual conditions using trifluoroacetic anhydride yielded the vinyl sulfides (8a, b), non-cyclized products, as a major product. The cyclization proceeded when boron trifluoride diethyl etherate was used as an additive reagent, thus giving rise to the corresponding cyclized products (7a) and (7b) in moderate yields. We propose that the enhancing effect of the Lewis acid on the cyclization may be attributable to the involvement of a dicationic intermediate, sulfonium-carbenium dication (23).

Benzazepines↗
PubMed2001

Low-dose tissue plasminogen activator followed by planned rescue angioplasty reduces time to reperfusion for acute myocardial infarction treated at community hospitals.

The time from admission to reperfusion in patients with acute myocardial infarction (AMI) was compared according to the type of hospital and treatment strategy. A total of 164 patients with a first AMI within 12h of onset were enrolled at one tertiary emergency center (TEC) and 6 community hospitals (CHs). The subjects were randomly assigned to receive either primary percutaneous transluminal coronary angioplasty (PTCA) (TEC-primary PTCA and CHs-primary PTCA groups) or 800,000 units of intravenous monteplase, half the standard dose of a mutant tissue plasminogen activator (t-PA), followed by rescue PTCA if the Thrombolysis in Myocardial Infarction (TIMI) flow grade was 2 or less (TEC-monteplase and CHs-monteplase groups) on the first coronary angiogram. Sixty minutes after admission, TIMI flow grade 3 rates of the study groups were as follows, in descending order: TEC-monteplase group, CHs-monteplase group, TEC-primary PTCA group, and CHs-primary PTCA group (56%, 41%, 36%, and 8%, respectively; p<0.01). However, there was no significant difference in the final TIMI flow grade 3 rate among the 4 groups. In the CHs, the peak creatine kinase tended to be lower in the monteplase group than in the primary PTCA group. The results suggest that low-dose monteplase followed by rescue PTCA is an effective strategy for promoting early reperfusion in patients with AMI, especially those who are treated at CHs.

Aged↗
PubMed2001

A case of renovascular hypertension due to bilateral renal artery microaneurysm who succeeded in baby delivery.

We report the case of a young pregnant woman with bilateral renovascular hypertension due to renal microaneurysms from an unknown cause, who had a successful delivery. Pregnancy did not affect the disease activity even in the postpartum period. Her blood pressure was maintained within the normal range by administration of labetalol. Although the angiographic appearance of the symmetrical aneurysms in both renal artery beds from the interlobular to arcuate artery levels suggested polyarteritis nodosa of multiple microaneurysms in the bilateral interlobular arteries, the clinical features suggested other causes of renovascular hypertension, such as fibromuscular dysplasia and/or congenital microaneurysms. We were thus unable to reach a definitive diagnosis.

Adrenergic beta-Antagonists↗
PubMed2001

Corticotroph cell adenoma without typical manifestations of Cushing's disease presenting with cavernous sinus syndrome following pituitary apoplexy.

This report presents a unique case of corticotroph cell adenoma in a 30-year-old man without acromegaly or features typical of Cushing's disease, who developed cavernous sinus syndrome following pituitary apoplexy. Magnetic resonance imaging revealed a large intrasellar/suprasellar mass with pituitary hemorrhage and extension of a hematoma to the anterior base of the skull. Urgent transnasal pituitary surgery revealed an acidophilic pituitary adenoma, with immunoreactivity for ACTH and GH and expression of proopiomelanocortin (POMC) and GH messenger ribonucleic acid (mRNA) demonstrated by in situ hybridization. To our knowledge, a silent corticotroph cell adenoma with GH production has never been reported. This type of adenoma may potentially enlarge and develop tumoral hemorrhage because it is free of endocrinological symptoms.

Adenoma↗
PubMed2001

Details of true calcium absorption and calcium excretion into feces in female rats during growth.

The details of calcium flux during growth were examined in female rats. Twenty-eight 53-d-old rats were equally divided into 4 groups. Rats were given a purified diet (0.5% Ca and 0.35% Pi) throughout the experiment. Calcium balance and 45Ca kinetics studies using an open two-compartment model were performed over a 3-d period when rats were 60 (control), 74 , 88 and 116 d old. A simple calcium balance study, using the last group, was carried out at the age of 102 d. Compared with the control group, true intestinal calcium absorption was significantly increased at 74 d, but then decreased in a time-dependent manner up to 116 d. The apparent intestinal calcium absorption began to decrease at 88 d, and decreased further with age. An increase in urinary calcium output was observed at 74 and 88 d in phase with calcium excretion into the intestine, and both variables returned to the control level at 116 d. Calcium into bone was decreased at 74 and 116 d. Calcium from bone similarly changed with Vo+ at 74 d: however the highest value was observed at 88 d. Thereafter, Vo- reached the control level at 116 d. Calcium balance rapidly decreased at 88, 102 and 116 d, but still remained positive. Calcium intake remained steady until 102 d, but was significantly decreased at the end of the experiment. The changes in calcium flux with age can be summarized as follows: 1) bone turnover decreased, calcium excretion into the urine and feces began to increase, and true intestinal calcium absorption increased, 2) apparent intestinal calcium absorption decreased, while calcium from bone and calcium excretion into the urine and feces increased, and 3) calcium intake and calcium into bone decreased.

Age Factors↗
PubMed2001

[A trial with single-agent vinorelbine in taxane-resistant non-small cell lung cancer].

It is reported that the single-agent administration of vinorelbine (VNR) is improper in salvage therapy for non-small cell lung cancer. However, there are few reports on its use as second line in taxane-containing chemotherapy. We used single-agent VNR administration for nine cases of taxane-resistant non-small cell lung cancer, and an antitumor effect was seen in four cases. We present three of these cases. A factor for the high response rate is considered to be that vinca alkaloid is not used as a pre-treatment. Moreover, VNR may be effective even if there is a gene mutation for beta tubulin, which causes taxane resistance.

Adult↗
PubMed2001

[Efficacy of low-dose mutant tissue-type plasminogen activator followed by planned rescue percutaneous transluminal coronary angioplasty as reperfusion therapy for acute myocardial infarction].

OBJECTIVES: The efficacy of injection of a low-dose mutant tissue-type plasminogen activator (mt-PA), monteplase, followed by planned rescue percutaneous transluminal coronary angioplasty (PTCA) was compared with that of primary PTCA. METHODS: A total of 164 patients with acute myocardial infarction within 12 hr from onset were randomly assigned to a treatment with 80 x 10(4) U bolus of monteplase (Group M) or no administration (Group P) by the envelope method, followed by immediate angiography with angioplasty in patients with Thombolysis in Myocardial Infarction (TIMI) flow grade 0, 1 or 2. RESULTS: There were no differences in baseline characteristics between the two groups. Initial angiography showed a higher reperfusion rate (TIMI 2 + 3: 21% + 38% vs 13% + 9%, p < 0.001) and the median time to TIMI 3 was shorter (63 vs 78 min, p < 0.005) in Group M than in Group P, but the final TIMI 3 rate was similar (93% vs 96%). Peak creatine kinase was lower, and predischarge left ventricular ejection fraction measured in 70% of all patients was higher (59 +/- 9% vs 54 +/- 14%, p = 0.02) in Group M than in Group P. Recurrent ischemia with ST elevation occurred in three patients in Group M, but death, re-acute myocardial infarction or stroke did not occur in either group and the rate of bleeding complication was similar (4.9% vs 3.7%). PTCA was performed less frequently in Group M, but medical expenses were comparable in both groups. CONCLUSIONS: Low-dose mt-PA followed by rescue PTCA is effective for early recanalization and preservation of left ventricular function without increases in bleeding complications or medical expenses. These results suggest that low-dose mt-PA should be given to all patients with acute myocardial infarction who are scheduled to undergo primary PTCA.

Aged↗
PubMed2001

[Combination chemotherapy of carboplatin and docetaxel for advanced non-small cell lung cancer (NSCLC)].

Since mid-1997, we have treated 60 patients with advanced NSCLC with carboplatin (CBDCA) plus docetaxel (TXT). CBDCA (300-400 mg/m2) and TXT (60 mg/m2) were given on day 1 every 3 weeks. The mean treatment cycle was 2.3 +/- 1.4 (range 1-7). Fifty-four patients had measurable tumors, of whom 2 patients achieved a complete response and 19 patients achieved a partial response (37.0%, 95% CI: 24.3-51.3%) (Ad 12/29, Sq 7/23, Lar 1/2). Median survival time was 12.8 months and 1 year survival was 53.6%. AUC of CBDCA was not related to response (AUC of responders and non-responders was 3.29). Myelosuppression was moderate (WBC 2,284 mm3, range 800-4,700, PLT 16.4 x 10(4) mm3, range 6.6-41.5 x 10(4), Hb 10.9 g/dl, range 6.4-15.8). Leukocytopenia was related to AUC of CBDCA (R2 = 0.1093) but thrombocytopenia was not related to AUC of CBDCA (R2 = 0.0553). Gastrointestinal toxicity was mild (grade 0-1: 57%, grade 2: 35%, grade 3: 8%, grade 4: 0%). Treatment with CBDCA plus TXT combination is safe and effective in patients with NSCLC.

Adult↗
PubMed2001

17 beta-Hydroxysteroid dehydrogenase type 2 expression and enzyme activity in the human gastrointestinal tract.

The 17 beta-hydroxysteroid dehydrogenases (17 beta HSDs) play an important role in the regulation of intracellular levels of biologically active sex steroid hormones in various human tissues. To date, eight distinctive 17 beta HSD enzymes have been cloned and characterized in humans. Among these isoenzymes, 17 beta HSD type 2 (17 beta HSD2) catalyses the conversion of testosterone into androstenedione and/or oestradiol into oestrone in various tissues, and it has thus been suggested to be involved in the biological inactivation of these sex steroids. The human gastrointestinal tract and liver are considered as the principle sites of inactivation and metabolism of various forms of orally administered sex steroids. We therefore examined 17 beta HSD2 expression and activity in human adult non-pathological gastrointestinal tract in order to clarify further the biological significance of this enzyme. A total of 80 specimens (40 from males and 40 from females) of normal oesophageal, stomach, duodenal, ileal, colonic and rectal tissues were examined for immunohistochemistry. Altogether, 17 tissue specimens were used for enzyme assay, and eight for RNA analysis. 17 beta HSD2 activity was detected in the stomach, duodenum, ileum, colon and rectum. 17 beta HSD2 mRNA was most abundant in the small intestine. 17 beta HSD2 immunoreactivity was localized almost exclusively to the absorptive epithelium, which may be involved in the inactivation of excessive endogenous and exogenous active sex steroids. Results from the present study thus suggest that the human gastrointestinal tract is an important sex steroid metabolizing organ in humans.

17-Hydroxysteroid Dehydrogenases↗