Biomedical subjects

T Machida

Publications and source records attributed to T Machida.

At least 19 recordsLinked to original sources

PubMed1995

Root canal preparation using the second harmonic KTP:YAG laser: a thermographic and scanning electron microscopic study.

Thermal and microstructural events resulting from KTP laser use during root canal preparation were investigated in 30 extracted single-rooted human teeth. In the first section of this study, thermal events occurring on the root surfaces of 18 teeth during and after exposure of the root canal were measured using thermography. A variety of parameters were used to determine settings that would be effective without causing thermal damage to the periodontal ligament. In the second section of the study, root canals of 12 teeth exposed to KTP laser irradiation at parameters derived from section 1 were evaluated using Scanning electron microscopy. KTP laser application at a power setting of 3 W, an exposure time of 2 s, and a frequency of 5 Hz, applied five times, removed smear layer and debris from the root canal surface at temperatures below the thermal injury threshold for periodontal tissue.

Argon↗

PubMed1995

Cochlioquinone A, an inhibitor of diacylglycerol kinase.

The effects of cochlioquinone A, isolated from Drechslera sacchari, were studied in vitro and in vivo. This compound specifically inhibited diacylglycerol kinase activity with Ki = 3.1 microM. The kinetics revealed that cochlioquinone A inhibited diacylglycerol kinase in competition with ATP, and non-competitively with diacylglycerol. The compound inhibited neither protein kinase C, epidermal growth factor receptor-associated protein tyrosine kinase, nor phospholipase C. Cochlioquinone A reduced the concentration of phosphatidic acid in T cell lymphoma with a half maximal concentration of 3 microM, and simultaneously augmented the phosphorylation of 80 kDa protein, a known substrate of protein kinase C. The degree of the phosphorylation of 80 kDa protein in the presence of cochlioquinone A was similar to that in the presence of phorbol myristate acetate (0.1 microgram/ml). These results demonstrate that cochlioquinone A is a specific inhibitor of diacylglycerol kinase, which regulates the activity of protein kinase C.

Animals↗

PubMed1995

[The antiemetic effect, safety and usefulness of tropisetron capsule in the treatment of nausea and vomiting induced by lower multiple dose of cisplatin].

The antiemetic effect, safety and usefulness of once daily administration of tropisetron 5 mg capsule for 3 to 5 consecutive days was investigated in 37 cases of 12 stations in total, suffering from nausea and vomiting induced by a lower multiple dose of cisplatin. The efficacy ratings assessed every 24 hours on day 1, 2, 3, 4 and 5 were 88.6%, 85.7%, 82.9%, 74.1% and 76.9%, respectively. The final efficacy rating was 82.9% (29/35 cases). Although no adverse event was observed, increases in GOT and GPT, whose cause and relation to the investigational drug were unknown, were noted in 2 cases. Cases rated as useful or better were 82.9% (29/35 cases) of the overall. The above results reveal that tropisetron 5 mg capsule is significantly effective and highly safe in the treatment of nausea and vomiting induced by lower multiple dose of cisplatin. Tropisetron 5 mg capsule is thus deemed extremely useful antiemetic drug.

Antiemetics↗

PubMed1995

[Clinical phase II study of tropisetron capsule in the treatment of nausea and vomiting induced by anti-cancer drugs].

A comparative clinical trial of tropisetron capsule was conducted in three dose groups to investigate its optimal dose on nausea and vomiting induced by anti-cancer drugs, including cisplatin. The doses were randomized by the central registration office. In the assessment of clinical efficacy, cases rated as "effective" or better accounted for 61.5% of the 2.5 mg group (16/26), 80.8% of the 5.0mg group (21/26) and 80.0% of the 10mg group (24/30), respectively; the ratings for the 5mg and 10mg groups were almost equivalent, which was higher than that for the 2.5mg group. Adverse events observed were fever, diarrhea, drowsiness, headache and/or facial erythema in 4 out of 97 cases. Abnormal laboratory findings noted were 6 cases of increased GOT, GPT, LDH, total bilirubin and/or creatinine, but none of these was serious or clinically problematic in particular. On the basis of the above results, the optimal dose of Tropisetron (capsule) is considered to be 5mg once daily.

Adult↗

PubMed1995

[Clinical phase III study of tropisetron capsule in the treatment of nausea and vomiting induced by anti-cancer drug; a placebo-controlled, multicenter, double-blind comparative study].

A placebo-controlled, double-blind comparative study of tropisetron capsule was conducted to assess its clinical usefulness for nausea and vomiting induced by the anticancer drug, cisplatin, at a single dose of 50 mg/m2 or higher. Either 5mg tropisetron capsule or its placebo was given orally to patients 2 hours prior to cisplatin administration; the clinical efficacy was determined the severity of nausea and the number of emesis that occurred during 24 hours after cisplatin. Tropisetron significantly exceeded the placebo in the assessment of clinical efficacy. The ratings for the tropisetron group and the placebo group were 91.7% (22/24 cases) and 25.9% (7/27 cases), respectively. Adverse events observed were one case of headache in the tropisetron group and one diarrhea in the placebo group, while neither case was serious nor clinically problematic in particular. The above results reveal that tropisetron 5 mg capsule is significantly effective in the treatment of anticancer drug-induced nausea and vomiting. It has also been confirmed that tropisetron is a useful agent without any safety problems.

Administration, Oral↗

PubMed1995

[Clinical phase III study of tropisetron capsule in the treatment of nausea and vomiting induced by carboplatin or non-platinum anti-cancer drugs].

A clinical phase III study of tropisetron capsule was conducted to assess its efficacy, safety and usefulness on nausea and vomiting induced by carboplatin or non-platinum anti-cancer drugs. The study was conducted in patients who experienced vomiting on previous chemotherapy. Tropisetron 5 mg capsule was given to patients once 2 hours prior to the first administration of either carboplatin or non-platinum anti-cancer drugs; the patients were then observed for nausea and/or vomiting during 24 hours after the first administration. Some 56.7% (17/30) of the patients did not vomit after tropisetron administration, and the frequency of vomiting was significantly reduced compared with that during the previous chemotherapy. Further, in the clinical efficacy ratings, in which the efficacy was assessed on the basis of the nausea and vomiting data, 83.3% (25/30) of cases were rated as "effective or better". Adverse events observed were 3 cases of mild headache, but these were not clinically problematic. The above results reveal that tropisetron capsule is significantly effective and safe in the treatment of nausea and vomiting induced by carboplatin or non-platinum anti-cancer drugs; in addition, tropisetron proved to be highly useful for its convenience as an oral agent.

Adult↗

PubMed1993

[Clinical evaluation of a new kit (IMX PA Dainapack) for detection of serum prostate specific antigen].

A study of the clinical utility of the IMx PA Dainapack, a new kit for detection of serum prostate specific antigen (PSA) by a fully automated enzyme immunoassay (EIA) system, was conducted. Results concerning reproducibility, dilution linearity and sensitivity were good. The excellent assay performance of this kit, particularly in terms of its high sensitivity (0.1 ng/ml), was confirmed. The upper limit of normal was determined to be 4.0 ng/ml from the mean +/- 3 S.D. (3.79 ng/ml) in healthy male controls (n = 244). Using 4.0 ng/ml as the upper limit of normal, 6 of 244 healthy male controls (2%) were positive. In various urinary diseases, 173 of 192 prostatic cancer (90%) and 46 of 112 benign prostatic hypertrophy (BPH) (41%) cases were positive. In prostatic cancer, the positive rates increased with the advance in clinical stage and in stage A the positive rate was especially high (8 of 12 (67%) were positive). On the other hand, using the BPH group as a negative control, the maximum accuracy rate for prostatic cancer had a cut-off value of 8.0 ng/ml. Thus, 8.0 ng/ml is an appropriate cut-off value differentiating prostatic cancer from BPH while 4.0 ng/ml is the cut-off value between the normal group and those with prostatic cancer (including stage A) and BPH. In the follow-up patients with prostatic cancer, serum PSA values measured by this kit reflected the effectiveness of treatment. The correlations between values obtained with the IMx PA Dainapack and 6 current kits were good (r = 0.93 to 0.99) but the values differed with the kit.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Differential effects of right-sided and left-sided orchidectomy on lateral asymmetry of LHRH cells in the mouse brain.

Luteinizing hormone-releasing hormone (LHRH) immunoreactive cells were found to be more numerous in the right side of the brain than in the left in male mice. Bilateral orchidectomy or removal of the right testis decreased the number of LHRH cells, while removal of the left testis failed to cause any changes in the number of LHRH cells. The results indicated a clear left-right difference in the neuroendocrine regulation of gonadal function in male mice.

Animals↗

PubMed1992

The 4th study of prophylactic intravesical chemotherapy with adriamycin in the treatment of superficial bladder cancer: the experience of the Japanese Urological Cancer Research Group for Adriamycin.

A multicentric randomised trial was conducted for the purpose of investigating the efficacy of intravesical chemoprophylaxis of superficial bladder cancers. A total of 443 patients (number of evaluable patients, 284) were registered from July 1987 to December 1989 and randomised into 3 groups. Group A received 21 intravesical instillations of Adriamycin (ADM) at 20 mg/40 ml physiological saline for 2 years after undergoing transurethral resection (TUR); group B was given the same dose as group A but received 6 intravesical instillations for 2 weeks before undergoing TUR; and group C served as a control and underwent TUR only. Better prophylactic effects were obtained in group A. The overall non-recurrence rates calculated for groups A and B differed significantly (P less than 0.05) on day 240, and those determined for groups A and C were also significantly different (P less than 0.01) on day 480. No benefit was obtained using intravesical instillation prior to TUR (group B). The major side effects encountered were pollakisuria and miction pain, which occurred in 32% of the patients in group A and in 52% of those in group B.

Administration, Intravesical↗

PubMed1992

Long-term results of intravesical chemoprophylaxis of superficial bladder cancer: experience of the Japanese Urological Cancer Research Group for Adriamycin.

Long-term results were analyzed in terms of tumor progression and survival in patients with superficial bladder cancer who were enrolled in the second intravesical chemoprophylactic study of the Japanese Urological Cancer Research Group for Adriamycin, which was started in July 1982. This study was a prospective, randomized, controlled trial conducted on primary tumors treated with a long-term instillation regimen that involved control versus intravesical instillations of Adriamycin or mitomycin C given once a week for the first 2 weeks, once every other week for 14 weeks, once a month for 8 months, and once every 3 months for 1 year, for a total of 21 instillations in 2 years. An analysis of the prophylactic effects of such treatment on bladder tumors after TUR has previously been performed, and the results have been published elsewhere. The present study represents a follow-up of the above trial. Of the 671 cases previously analyzed with regard to tumor prophylaxis, 158 cases (23.5%) were eligible to be followed for tumor progression and survival. A detailed comparison of the background factors between these 158 patients and the other 513 cases revealed no statistically significant difference. Thus, the 158 evaluable cases might reasonably be considered to represent all patients enrolled in the second study, and the results were thought to be reasonable enough to reflect the long-term efficacy of the long-term instillation regimen adopted in this study. The median follow-up for these 158 cases was 6.6 years. Tumor progression in terms of the disease stage and/or grade occurred in 43 of 127 patients who received prophylactic instillations and in 12 of 31 control cases. No significant difference in the incidence of tumor progression was found between the treatment and the control groups. In addition, no difference in survival was observed between the treatment group and the control group. Survival was also compared between patients who showed tumor progression and those who did not. All patients whose tumors did not progress survived, whereas the 7-year survival of those exhibiting tumor progression was less than 90%.

Actuarial Analysis↗

PubMed1992

Evaluation of systemic chemotherapy with methotrexate, vinblastine, adriamycin, and cisplatin for advanced bladder cancer. The Japanese Urological Cancer Research Group for Adriamycin.

In a cooperative study of the Japanese Urological Cancer Research Group for Adriamycin, the usefulness of chemotherapy with methotrexate, vinblastine, Adriamycin, and cisplatin (M-VAC therapy) in treating advanced or recurrent bladder cancer was examined. Evaluation of the clinical responses obtained in 86 evaluable patients revealed 13 complete responses, 29 partial responses, 4 minor responses, 19 cases of no change, and 21 cases of progressive disease. The overall response rate was 48.8% (42/86). The rate of response to M-VAC therapy at each disease site was as low as 21.4% (3/14) in bone lesions but exceeded 40% in the primary lesion, the lymph nodes, the lung, the liver, and other lesions. The clinical response to M-VAC therapy was not significantly influenced by the performance status of the patients, the dose intensity, or previous therapy. The median duration of response for the 42 responders was 22.7 weeks (range, 8.1-134.1 weeks), and the median duration of survival for the 86 evaluable patients was 9.8 months. Side effects were frequently encountered; the patients experienced anorexia, nausea, vomiting, malaise, alopecia, and leukopenia, but all of these symptoms were tolerable.

Adult↗

PubMed1992

Prognostic significance of location of lymph node metastases in colorectal cancer.

The prognostic value of stage of lymph node metastases was evaluated in 357 patients who underwent curative resection for colorectal cancer. Subdivision of Dukes C patients according to the number of positive nodes revealed that the five-year disease-free survival rate (5DFS) was 63 percent in the patients with one to three nodes and 53 percent in those with four or more nodes (not significantly different). Classification according to the location revealed that 5DFS was 70 percent in those who had only local node metastases (n1+), compared with 40 percent in those who had distant node metastases along the major vessels (n2+) (P < 0.001). Twelve of 38 n2+ patients had only one distant node metastasis with no local node involvement (skip metastasis). They had lower 5DFS than the n1+ patients who had three or more positive local nodes (35 percent vs. 57 percent). We conclude that the location, rather than the number, of nodal metastases has a higher impact on prognosis in colorectal cancer patients.

Colorectal Neoplasms↗

PubMed1992

High survival of rabbit morulae after vitrification in an ethylene glycol-based solution by a simple method.

Rabbit morulae were exposed to a vitrification solution-modified PBS [PB1] medium containing 40% ethylene glycol + 18% Ficoll + 0.3 M sucrose (EFS) for 2, 5, or 10 min at 20 degrees C and were vitrified in liquid nitrogen. When morulae were rapidly warmed, 96% had an intact zona pellucida. When embryos were cultured after removal of the mucin coat, high proportions of them formed blastocoel (79-100%), but the percentage of embryos developed to fully expanded blastocysts decreased with increased exposure time 87%, 40%, and 17%). The survival rate of morulae vitrified after removal of the mucin coat was lower than that of mucin-intact embryos. To assess the development potential in vivo, 131 embryos were vitrified after 2 min of exposure to EFS solution; all the embryos were recovered and 120 were transferred to recipients without removal of the mucin coat, resulting in 78 (65%) full-term fetuses or young. This simple method, which yields high survival both in vitro and in vivo, will be of practical use for vitrifying rabbit embryos.

Animals↗

PubMed1992

Survival of mouse morulae vitrified in an ethylene glycol-based solution after exposure to the solution at various temperatures.

Mouse morulae were exposed in one step to a vitrification solution (EFS, a modified PBS containing 40% ethylene glycol, 18% Ficoll, and 0.3-M sucrose) at various temperatures, then cooled rapidly in liquid nitrogen, and then warmed rapidly. All of the embryos exposed to the EFS solution for 0.5 min at 25 degrees C before vitrification developed in culture. However, survival rates were lower if the duration of exposure was prolonged to 2, 5, or 10 min. At lower ambient temperatures (20, 10, and 5 degrees C), high survival rates were associated with longer exposure to the EFS solution. The toxicity of the EFS solution was also lower at lower temperatures. The toxic injury of morulae was manifested as decompaction of the blastomeres. Among the three additives in the EFS solution, ethylene glycol, which can cross cell membranes, was responsible for the toxicity. The results show that the optimum time for exposure of the embryos to the EFS solution before rapid cooling varies with the ambient temperature, i.e., 0.5 min at 25 degrees C, 0.5-5 min at 20 degrees C, 2-5 min at 10 degrees C, and 2-10 min at 5 degrees C. If they are exposed for an optimum period, almost all mouse morulae can survive vitrification (94-100%).

Animals↗

PubMed1992

Effects of amiloride on distal renal tubule sodium and calcium absorption: dependence on luminal pH.

The goal of our study was to examine the effects of amiloride on distal renal tubule calcium and sodium absorption at low and high luminal pH. In vivo microperfusion of distal convoluted tubules were performed on rats. Total Ca and Na concentrations in perfusion and collected fluids were measured by atomic absorption spectrometry. When tubules were perfused with low pH perfusate (pH = 5.6), net calcium absorption (JCa) averaged 5.4 pmol/min. With high pH perfusate (pH = 7.1), JCa was significantly higher averaging 8.9 pmol/min. (P less than 0.01). In contrast, net sodium absorption (JNa) was not affected by luminal pH (231 pmol/min. versus 237 pmol/min.). At low luminal pH, 10(-4) M amiloride analogue (5-N-methyl-N-isobutyl amiloride) (MIA) inhibited sodium absorption but stimulated calcium absorption. At high luminal pH MIA still inhibited Na absorption but it had no effect on calcium absorption. Thus, the natriuretic effect of amiloride appears to be independent of luminal pH, while the amiloride-stimulated distal calcium absorption is observed at low but not at high luminal pH.

Absorption↗

PubMed1992

[Single-dose treatment of tosufloxacin (TFLX) for acute uncomplicated cystitis].

The effectiveness of a single 300-mg dose of tosufloxacin and of 3-day treatment with tosufloxacin (300 mg daily) were compared in a prospective trial in order to clarify the cost-effectiveness of tosufloxacin for acute uncomplicated cystitis. Fifty female patients (25 patients of each group) with acute uncomplicated cystitis received one of these treatment regimens, and the clinical data and follow-up culture results were analyzed. The effectiveness rates of single-dose treatment and 3-day treatment after 3 days were 100% and 96%, respectively. The recurrence rates of single-dose treatment and 3-day treatment after 14 or 28 days were 0% (0/13 patients) and 15% (2/13 patients), respectively. There was no significant difference in the effectiveness rate and the recurrence rate between these two groups, statistically. All isolated strains were eliminated in both regimens. From these results, it is suggested that single-dose treatment of tosufloxacin is effective enough for acute uncomplicated cystitis.

4-Quinolones↗

PubMed1992

Alterations of gluconeogenesis by ischemic renal injury in rats.

This study was designed to determine changes in one metabolic function, gluconeogenesis (GLG), after ischemic renal injury. Tubule suspensions were prepared by collagenase treatment of SD rat kidneys on 1, 3, and 7 days after left renal artery and vein occlusion for 0-90 min and incubated in Krebs-Henseleit buffer with or without 2 mM pyruvate or malate aerobically. Glucose contents were assayed photometrically. On days 1 and 3 after ischemia for longer than 60 min, serum creatinine levels rose significantly. The tendency of increase of GLG was observed on days 1 and 3 after 10-60 min of ischemia. GLG increased significantly on day 1 after 30-min ischemia. On the other hand, GLG decreased significantly on day 1 after 90-min treatment. Morphologic damage was limited to the corticomedullary region on days 1 and 3 after ischemic times of 30 and 60 min. These results suggest that renal GLG is stimulated to supply energy for ATP decrease by ischemia and for further regeneration in extraproximal segments along the nephron.

Acute Kidney Injury↗

PubMed1992

[Analysis of tumor volume in latent prostatic carcinoma].

An assessment has been made of the histopathological characteristics of latent prostatic carcinoma and the tumor volume in 500 male Japanese patients who underwent dissection at The Jikei University since 1983. A microscopic observation was made of the prostatic glands extirpated totally at the necropsy, fixed with formalin and prepared as a step-section in a thickness of 3 mm. In the cases of latent carcinoma, after photographing the lesion in the same magnification and measuring the area of the carcinoma lesion with a digitizer, the volume was calculated by multiplying the thickness of 3 mm, and carcinoma volume was determined by integrating the value of each slice and adjusted by a conversion formula. The incidence of latent carcinoma was 104 cases out of 500 (22%). The incidence increased as the age layer becomes higher, and latent carcinoma was observed in 44% of the patients aged 80 and above. Complication of latent carcinoma with prostatic hyperplasia was presumed to be an independent phenomenon in so far as it is seen from the statistical aspect. The patients were classified histopathologically into well-differentiated type (64%), mixed type (27%) and poorly-differentiated type (9%), showing high incidence in the low-aged layer of well-differentiated lesions and in the high-aged layer of mixed type lesions and in the high-aged layer of mixed type lesions. The average tumor volume of latent carcinoma was so small as 231 mm3, but many of the lesions in the cases of well-differentiated type were small, being on average 103.9 mm3, but many of the lesions in the cases of poorly-differentiated type were large, being on average 642.2 mm3. Statistically, with a tumor size of 200 mm3 as the boundary, a difference was observed in the distribution of histological constitution between the group with smaller lesions and the group with larger lesions. As an application of this result to the clinical carcinoma of stage A, the value of volume of 200 mm3 was considered to be important as a diagnostic criterion in deciding the necessity of treatment.

Adenocarcinoma↗