Biomedical subjects

N Masuda

Publications and source records attributed to N Masuda.

At least 163 records · Page 9Linked to original sources

PubMed1991

Primary structure of protein moiety of Penicillium notatum phospholipase B deduced from the cDNA.

Phospholipase B has not yet been well defined. The most important points about this enzyme are its relationships with lysophospholipase and phospholipase A1. As reported [Saito, K., Sugatani, J. & Okumura, T. (1991) Methods Enzymol. 197, 446-456], Penicillium notatum phospholipase B is a glycoprotein with a molecular mass of 95 kDa and intrinsic lysophospholipase and phospholipase B activities; however, by endogenous proteolytic modification, its phospholipase B activity is lost almost completely, whereas its lysophospholipase activity remains unchanged. A cDNA library of P. notatum was screened by hybridization with two synthetic oligodeoxyribonucleotide probes, which corresponds to two different pentapeptides of the enzyme. A hybridization-positive clone, pPLB18, was isolated and its nucleotide sequence was determined. The deduced amino acid sequence was quite different from that found previously. Therefore, we rescreened the cDNA library with a Sau3AI fragment derived from pPLB18 and isolated a new clone, pPLB15. Comparison of the nucleotide sequences of pPLB15 and pPLB18 revealed that pPLB18 contained an insertion sequence of 53 bp. Consequently, the reading frame was open downstream for 603 amino acid residues. From the assigned sequence, it was deduced that the limited proteolysis occurred between Leu175 and Asp176; eight cysteine residues and 16 potential N-glycosylation sites were also found. No amino acid sequence similarity was found with other proteins, including other phospholipases.

Amino Acid Sequence↗

PubMed1991

Establishment of tumor cell lines as an independent prognostic factor for survival time in patients with small-cell lung cancer.

We studied tumor samples from 39 patients, who entered our study from January 1989 to May 1990, to assess whether the ability to establish a continually growing tumor cell line from fresh tumor specimens can be associated with decreased survival times in patients with small-cell lung cancer. The tumor samples were used to establish cell lines in culture using a serum-free medium supplemented with hydrocortisone, insulin, transferrin, estrogen, and selenium (HITES). Thirty-three of these specimens were obtained by fiberoptic bronchoscopy from primary sites during routine diagnostic procedures. A total of 11 (28%) cell lines were established: seven (21%) from 33 primary tumors and four (80%) from five peripheral lymph nodes. Survival times of the 11 patients whose tumor cell specimens continually grew in culture at any time during their clinical course were significantly shorter than those of the 28 patients whose tumor cell specimens did not grow in vitro (median survival time of 26 weeks versus 73 weeks; P = .0068). Cox's proportional hazards model, including sex, age, Eastern Cooperative Oncology Group performance status, stage, source of specimen, treatment, and in vitro tumor cell growth in the overall patient group, showed that cell line establishment (P = .0017) and no therapy (P = .0015) were the most important factors indicating poor survival time. For the subgroup of 23 primary tumor patients, the important factors (in decreasing order) that indicated decreased survival times were the establishment of a cell line (P = .0112) and with cyclophosphamide-doxorubicin-vincristine alternating with cisplatin-etoposide, versus cisplatin-vincristine-doxorubicin-etoposide therapy (P = .0463). Our study demonstrates that in vitro tumor cell growth is an adverse predominant prognostic factor in patients with small-cell lung cancer.

Aged↗

PubMed1991

Possible involvement of GTP-binding proteins in growth regulation of human epidermoid carcinoma cell line A431.

A431 cells, a human epidermoid carcinoma cell line, express an unusually large number of cell surface receptors for the epidermal growth factor (EGF). The growth rate of A431 cells was estimated by measuring [3H]thymidine incorporation at the logarithmic growth phase. The growth of the cells in protein-free medium was partially inhibited by exposure of the cells to pertussis toxin, islet-activating protein (IAP). The growth in both serum-containing and protein-free medium was inhibited by high concentrations of EGF, and these inhibitions were partially reversed by treatment of the cells with IAP. The effects of IAP were well correlated with the degree of ADP-ribosylation of a membrane 40-kDa protein. Thus, IAP sensitive G-proteins appear to be involved in the signal transduction of both positive and negative regulation of A431 cell growth. The possibility is also discussed that phosphatidylinositol turnover may participate in growth regulation.

Carcinoma, Squamous Cell↗

PubMed1991

Phase I study of weekly intravenous infusions of CPT-11, a new derivative of camptothecin, in the treatment of advanced non-small-cell lung cancer.

7-Ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy-camptothecin (CPT-11) is a novel camptothecin derivative that has been selected for clinical evaluation because of its broad spectrum of antitumor activity in animal models and its unique inhibitory effects on mammalian DNA topoisomerase I. Seventeen patients with advanced non-small-cell lung cancer were treated with CPT-11 at weekly dose levels ranging from 50 to 150 mg/m2. At least three weekly doses were given to all patients except four, and a total of 74 weekly doses were given to the 17 patients. The dose-limiting toxic effects were myelosuppression (predominantly leukopenia) and unpredictable diarrhea. Gastrointestinal toxic effects were severe and not well controlled by standard therapy in some patients. Interpatient variability of toxic effects was substantial (including two deaths) and did not correlate with the pharmacokinetic parameters of CPT-11 and 7-ethyl-10-hydroxycamptothecin, its major metabolite. Two previously untreated patients, who received doses of 100 and 125 mg/m2, had partial responses lasting 3.2 and 4.0 months, respectively. The maximum tolerated dose on this schedule was 100 mg/m2, which we also recommend as a starting dose for phase II studies. This schedule appears to allow a CPT-11 dose intensity which is double the dose intensity possible on a once-a-month schedule. However, careful supervision to assess gastrointestinal toxic effects and myelosuppression is indispensable because of wide individual differences in drug tolerance.

Aged↗

PubMed1991

A phase I study of chronic daily dosing of oral etoposide in combination with cisplatin for patients with advanced cancer.

A dose escalation study of daily oral etoposide and cisplatin was carried out on 22 patients with advanced cancer using starting doses of 20 mg/m2/d of etoposide given orally for 21 days and 80 mg/m2 of cisplatin given intravenously (IV) on day 1. A total of 40 courses were given. Myelosuppression was the major dose-limiting toxicity, with a maximum tolerated dose of 50 mg/m2/d of oral etoposide for 21 days plus 80 mg/m2 of IV cisplatin on day 1. Doses of 40 mg/m2/d of etoposide for 21 days plus 80 mg/m2 of cisplatin for 1 day in four of eight courses (50%) were associated with Grade 3 or worse leukopenia that occurred between days 18 and 26. However, no Grade 3 or worse thrombocytopenia occurred at this dose level. Nausea and vomiting occurred in most patients at each dose level but were mild and could be controlled by antiemetics. Alopecia also occurred frequently. Significant mucositis (Grade 4) occurred in one patient, but no other toxicities were observed. Four partial responses that lasted from 1.3 to 5.8+ months were observed in patients with cervical (one patient), small cell lung (one patient), and squamous cell lung cancer (two patients); one of them had been heavily pretreated with platin analogue-containing regimens. The recommended doses for Phase II studies on this schedule are 40 mg/m2/d of oral etoposide for 21 days plus 80 mg/m2 of IV cisplatin on day 1. A combination regimen on this schedule seems particularly effective in patients with etoposide-sensitive malignancies.

Adult↗

PubMed1991

Neurons in the caudal ventrolateral medulla mediate the arterial baroreceptor reflex by inhibiting barosensitive reticulospinal neurons in the rostral ventrolateral medulla in rabbits.

Participation of the caudal ventrolateral medulla in the arterial baroreceptor reflex was examined in urethane-anesthetized, vagotomized and immobilized rabbits whose aortic nerve was cut bilaterally. The extent of the caudal ventrolateral medulla was mapped by decreases in the renal sympathetic nerve activity and arterial pressure following a local microinjection of a neuroexcitatory amino acid, sodium glutamate (0.075-1.5 nmol). It extended between the levels 1.3 mm rostral and 3.0 mm caudal to the obex. An injection of sodium glutamate into the caudal ventrolateral medulla also diminished spontaneous activity of barosensitive reticulospinal neurons in the rostral ventrolateral medulla. In the 'split medulla preparation' in which the medulla was split along the midsagittal plane to disrupt fiber connections associating both sides, a neurotoxic agent, kainic acid, was injected unilaterally into the rostral ventrolateral medulla. This treatment markedly attenuated responses of renal sympathetic nerve activity and arterial pressure induced by a sodium glutamate injection into the ipsilateral caudal ventrolateral medulla, whereas responses to an injection into the contralateral caudal ventrolateral medulla were totally preserved. In four separate experiments, three to five injections of kainic acid were made unilaterally to cover the whole extent of the caudal ventrolateral medulla. The sympathoinhibitory and depressor responses to stimulation of the ipsilateral aortic nerve were then totally abolished. Simultaneously, the cardiac cycle-related rhythmic fluctuation of renal sympathetic nerve activity, which represented activity of the carotid sinus baroreceptor reflex, was attenuated to the noise level. These results, together with our previous electrophysiological demonstration of barosensitive caudal ventrolateral medulla neurons with axonal projections to the rostral ventrolateral medulla, strongly support the hypothesis that neurons in the caudal ventrolateral medulla mediate the arterial baroreceptor-vasomotor reflex through inhibition of barosensitive reticulospinal neurons in the rostral ventrolateral medulla.

Animals↗

PubMed1991

Placebo-controlled double-blind comparative study on the preventive efficacy of mesna against ifosfamide-induced urinary disorders.

In order to evaluate the preventive efficacy, safety and usefulness of mesna (Sodium 2-mercaptoethane sulfonate) against ifosfamide-induced urinary disorders, a placebo-controlled double-blind comparative study was performed. Ifosfamide was administered by intravenous drip infusion at a daily dose of 2 g/m2 for 5 consecutive days, and mesna was intravenously administered at 20% of the ifosfamide dose, three times daily for 5 consecutive days. The results obtained are as follows. (a) Of 101 accrued patients, 91 patients were evaluated consisting of 45 for the mesna group and 46 for the placebo group. There was no intergroup difference in the number of the evaluated cases and patient characteristics. (b) Micturition pain and feeling of residual urine graded as moderate or severe were not observed for the mesna group, but were observed for the placebo group with incidences of 19.6% (9/46) for micturition pain and 15.2% (7/46) for feeling of residual urine; the intergroup differences in the appearance of these urinary symptoms were statistically significant (P = 0.0003 for micturition pain; P = 0.0009 for feeling of residual urine). The incidence of hematuria graded as moderate or severe was 6.7% (3/45) in the mesna group, which was significantly lower than the 32.6% (15/46) in the placebo group (P = 0.0008). (c) No side-effect attributable to mesna was observed. (d) A judgment of "useful" was obtained in 80.0% (36/45) of the patients treated with mesna, which was significantly higher than the 34.8% (16/46) of the patients treated with placebo (P = near 0). On the basis of the above results, we conclude that the preventive efficacy, safety and usefulness of mesna against ifosfamide-induced urinary disorders have been well demonstrated in this study.

Adult↗

PubMed1991

Redevelopment of small-cell lung cancer nine years after the start of therapy. A case report and review of the literature.

Most patients with small-cell lung cancer usually relapse within 1 to 2 years. Relapses after a 5-year disease-free interval occur extremely rarely. This report describes a patient with limited-stage small-cell lung cancer who had achieved a complete response to combination chemotherapy followed by chest irradiation but developed small-cell lung cancer 9.4 years after the beginning of therapy. Small-cell lung cancer recurred in the same side of the lung, in the mediastinal nodes, and in the liver. The pattern of development of small-cell lung cancer suggests that the patient had a relapse rather than a metachronous lung cancer. To our knowledge, this is the second-latest relapse of small-cell lung cancer in the literature.

Aged↗

PubMed1991

Increase in susceptibility of Pseudomonas aeruginosa to carbapenem antibiotics in low-amino-acid media.

The in vitro susceptibility of Pseudomonas aeruginosa PAO1 to carbapenem antibiotics, such as CS-533, was influenced by various concentrations of basic amino acids, i.e., L-lysine, L-histidine, and L-arginine, in agar media. P. aeruginosa PAO1 showed higher susceptibility to carbapenems in minimal medium than it did in rich media such as Mueller-Hinton II agar. The susceptibility was decreased by the addition of a basic amino acid to the minimal medium, whereas it was influenced less by other amino acids. The susceptibility of PAO1 to cephalosporins, piperacillin, quinolones, and gentamicin was not influenced by the addition of a basic amino acid to the minimal medium. A significant change in susceptibility to carbapenems by the addition of a basic amino acid was not observed with D2 protein-deficient mutants of PAO1. Clinical isolates of P. aeruginosa also showed an increase in susceptibility in minimal medium. L-Lysine in minimal medium did not have any influence on the production of D2 protein, beta-lactamases, or penicillin-binding proteins of PAO1 or on the chemical degradation of CS-533. These results strongly indicate that the increase in susceptibility of P. aeruginosa to carbapenems relates to less competition with basic amino acids for permeation through the D2 protein channel of P. aeruginosa.

Agar↗

PubMed1991

A randomized trial in inoperable non-small-cell lung cancer: vindesine and cisplatin versus mitomycin, vindesine, and cisplatin versus etoposide and cisplatin alternating with vindesine and mitomycin.

Patients with inoperable non-small-cell lung cancer (NSCLC) were randomly assigned to receive one of three dosage regimens: (1) vindesine and cisplatin (VP); (2) mitomycin, vindesine, and cisplatin (MVP); or (3) etoposide and cisplatin alternating with vindesine and mitomycin (EP/VM). In 199 assessable patients, the response rates were VP, 33%; MVP, 43%; and EP/VM, 19%. The addition of mitomycin to the VP regimen did not significantly improve the response rate. The response rate was significantly lower with the EP/VM regimen than with the MVP regimen (P less than .01). The median survival times were VP, 50 weeks; MVP, 42 weeks; and EP/VM, 40 weeks. These differences were not significant. Grade III or IV thrombocytopenia was significantly greater (P less than .01) in MVP patients (22%) than in the VP (5%). Other toxicities were similar in the three groups. Analyses of prognostic factors showed that treatment with MVP, sex, and histologic classification (squamous cell carcinoma) were predictive of improved response. Important factors for improved survival, according to the Cox regression analysis, were the stage of disease, performance status, sex, weight loss before diagnosis, and hemoglobin concentration.

Adult↗

PubMed1991

Establishment and characterization of 20 human non-small cell lung cancer cell lines in a serum-free defined medium (ACL-4).

To facilitate the studies in cell biology and drug sensitivity of non-small cell lung cancer, cell samples from 55 patients have been used to establish cell lines in culture using a chemically defined medium (ACL-4). A total of 20 cell lines (36 percent) were directly established and characterized: 14 (44 percent) from pleural effusions, five (29 percent) from resected primary tumors, and one (25 percent) from ascitic fluids. They comprised 16 adenocarcinoma, two large cell carcinoma, one squamous cell carcinoma, and one malignant mesothelioma. Each cell line had distinct gross morphologic features and population doubling times from 21 to 75 h. The plating efficiency was 0.01 to 9.51 percent. The modal chromosome number varied from 45 to 108. Secretion of tumor markers (carcinoembryonic antigen, sialyl Lewis Xi, CA 50, CA 125, and CA 19-9) into the medium was also different in each cell line. Most of the cell lines have been xenografted into nude mice and found to be tumorigenic. Survival of 20 patients whose tumor cell specimens continually grew in culture at any time during their clinical course was significantly shorter than that of 35 patients with no in vitro tumour growth (median survival time of 28 weeks vs 53 weeks, p = 0.0093). Our study indicates that in vitro tumor cell growth appears to be an adverse prognostic factor in patients with non-small cell lung cancer.

Adult↗

PubMed1991

[The significance of CA-50, SLX and ST-439 in lung cancer].

Serum levels of CA-50, SLX and ST-439 were measured in 213 patients with lung cancer (92 adenocarcinomas, 63 squamous cell carcinomas, 37 small cell carcinomas and 21 large cell carcinomas) and 87 patients with benign lung disease. The overall positive rates in patients with lung cancer were 12.8% for CA-50, 29.7% for SLX and 25.3% for ST-439. The positive rates for CA-50, SLX and ST-439 in adenocarcinoma patients were 22.8%, 42.4% and 38.0%, respectively. Of the patients with benign lung disease, 4.8% were false positive for CA-50, 15.3% for SLX and 3.6% for ST-439. In the patients with adenocarcinoma of the lung, the combination assay of CEA and ST-439 had a highly accurate rate (61.9%).

Adenocarcinoma↗

PubMed1991

A randomized trial comparing imipenem/cilastatine alone with latamoxef plus tobramycin in febrile neutropenic patients with lung cancer.

We conducted a randomized trial to compare the efficacy of imipenem/cilastatine (IPM/CS) monotherapy with that of a combination of latamoxef (LMOX) and tobramycin (TOB) in the initial management of fever and neutropenia in patients with lung cancer. Leukocytopenic febrile patients (less than 3,000 leukocytes per microliters; temperature greater than 38 degrees C) with lung cancer given induction therapy were randomly assigned to receive intravenous treatment with either 1 g IPM/CS twice daily or 2 g LMOX plus 90 mg TOB twice daily. A total 101 febrile episodes were studied. Fifty-one episodes were treated with IPM/CS and 50 with LMOX+TOB. Fifty-nine of the febrile episodes were bacteriologically confirmed, while an organism could not be isolated despite the presence of obvious clinical infection in the remaining 42. The response rate was 82% with IPM/CS and 80% with combination therapy. This difference was not statistically significant. The response rate regarding gram-negative infections was 10 out of 14 (71%) in the IPM/CS group and seven out of 12 (58%) in the LMOX+TOB group. This difference was also not significant (P = 0.484). The response rate in severely neutropenic patients (neutrophils less than 100/microliters) was low (P = 0.078). Three patients in the IPM/CS group were withdrawn from the study due to skin rash and vomiting. Therapy with IPM/CS monotherapy was as effective as a combination regimen.

Adult↗

PubMed1991

[Evaluation of pulmonary capillary wedge pressure tracing for the detection of intraoperative myocardial ischemia].

We studied the usefulness of the pulmonary capillary wedge pressure (PCWP) tracing for the detection of intraoperative myocardial ischemia. Both PCWP wave forms and 7-lead electrocardiogram were monitored in 109 patients undergoing coronary artery bypass graft surgery. Measurements were made six times in each patient. Myocardial ischemia was identified in 99 (27%) of the 366 measurements, and among them, 68 (69%) developed abnormal PCWP wave forms (AC wave greater than 15 mmHg, or V wave greater than 20 mmHg). Although these results were consistent with those of Kaplan et al (1981), we could not agree with their conclusion that PCWP tracing can be helpful in the early diagnosis of subendocardial ischemia. It was not possible to record PCWP continuously because of the risk of pulmonary infarction, and PCWP was influenced by noncardiac factors such as sympathetic reaction to surgical stimuli. We think that PCWP tracing would be of benefit in detecting intraoperative serious ischemia; serious myocardial ischemia was likely to have occurred when abnormalities in both PCWP tracing and ST segment changes were identified. The incidence of both PCWP changes and ECG ischemia was highest in the postbypass period, suggesting that the risk of serious myocardial ischemia is highest in the post-bypass period.

Aged↗

PubMed1991

[High-dose Tegafur (FT) for primary lung cancer: a phase I trial].

A phase I clinical study of intravenous Tegafur was conducted in nineteen previously treated patients with primary lung cancer. The dose of Tegafur was elevated from 1.0 to 3.0 g/m2/day for five consecutive days to determine the maximum tolerated dose. The dose-limiting factors were gastrointestinal and neurological toxicity and fatigability observed with the dose level of 2.5 g/m2/day for 5 days. Hematologic, hepatic and renal toxicities were not observed. Gastrointestinal toxicity including nausea, vomiting, anorexia and diarrhea of over grade 2 were seen to result from the dose of 2.5 g/m2/day. Neurological toxicity consisted of headache, dizziness, anxiety and depression. At the dose level of 2.0 g/m2/day, one patient, who had epileptic seizures in the past, experienced a psychomotor seizure. Depression (Grade 2 CNS toxicity) was observed at the dose level of 3.0 g/m2/day. Dose limiting factors were neurological toxicities. The pharmacokinetics of tegafur and 5-FU (the active form of Tegafur) has been studied in all patients. Serum level of tegafur was measured by HPLC method, and serum level of 5-FU was analyzed by GC-MS method. At the dose level greater than 2.0 g/m2/day for 5 days, the mean serum 5-FU values appear over the therapeutic range (0.1 micrograms/ml). In conclusion, 2.5 g/m2/day for 5 days was considered to be MTD, and 2.0 g/m2/day for 5 days intravenous administration was recommended for the phase II trial of single agent chemotherapy.

Drug Administration Schedule↗

PubMed1990

Activity of barosensitive neurons in the caudal ventrolateral medulla that send axonal projections to the rostral ventrolateral medulla in rabbits.

In urethane-anesthetized rabbits, we successfully recorded unit activity of four neurons in the caudal ventrolateral medulla (CVLM) that were excited by orthodromic stimulation of the aortic nerve and by antidromic stimulation of the rostral ventrolateral medulla (RVLM). The sum of mean onset latency of excitation to stimulation of the aortic nerve (37.5 ms) and mean conduction time of antidromic spikes (10.5 ms) was close to the mean onset latency of inhibition of reticulospinal neurons in the RVLM to stimulation of the aortic nerve (47.1 ms) as previously reported by us. Three of 4 neurons received excitatory input from carotid sinus baroreceptors as well. Our results provide strong evidence for the hypothesis that neurons in the CVLM subserve the arterial baroreceptor-sympathetic vasomotor reflex.

Animals↗

PubMed1990

Evaluation of high-dose etoposide combined with cisplatin for treating relapsed small cell lung cancer.

The synergism of combined high-dose etoposide with standard dose cisplatin (HD-EP) was evaluated in 20 patients who had relapsed after treatment of small cell lung cancer. Each patient was given etoposide at 500 mg/m2/day on days 1 to 3 and cisplatin at 80 mg/m2 (two patients given 120 mg/m2) on day 1; autologous bone marrow was not transplanted. Five patients were given recombinant human granulocyte colony-stimulating factor (rhG-CSF, 50 micrograms/m2) in an attempt to reduce HD-EP induced neutropenia. The overall response was 50% (9 of 18); one complete response (6%), eight partial responses (44%), seven no change (39%), and two progressions of disease (11%). Of the 18 evaluable patients, 12 had been treated with regimens of conventional doses of etoposide with conventional doses of cisplatin or carboplatin, and of these, five (42%) achieved a partial response. The median duration of response was 8.4 weeks (range, 5.3 to 17.7) and the median survival time was 20.3 weeks (range, 1.6 to 91). All of the patients developed severe myelosuppression; rhG-CSF did not shorten the period of the leukopenia. Mucositis and liver dysfunction were the major nonhematologic manifestations of toxicity. Two treatment-related deaths resulted from sepsis. These results suggest that the activities of high doses etoposide with standard doses of cisplatin are synergistic against small cell lung cancer.

Aged↗

PubMed1990

Combination chemotherapy with or without radiation therapy in small cell lung cancer. An analysis of a 5-year follow-up.

From January 1978 to March 1984, a series of 159 patients with newly diagnosed small cell lung cancer (SCLC) was treated with combination chemotherapy with or without chest radiation at the Osaka Prefectural Habikino Hospital. By March 31, 1989, ten patients (6.3%) had survived for 5 years or more after the initial chemotherapy, including nine of 95 patients (9.5%) with limited disease and one of 64 patients (1.6%) with extensive disease. All these 5-year disease-free survivors, except for one patient whose response could not be assessed by chest radiograph because of radiation fibrosis, had a complete response. Nine of the 71 patients (12.7%) treated with combination regimens containing doxorubicin survived 5 years or more, and only one of the 88 (1.1%) treated with regimens without doxorubicin had long-term survival (P less than 0.01). The sex, performance status (PS), and chest radiation after systemic chemotherapy did not correlate statistically with long-term survival (P greater than 0.05). Three of the ten patients died free of SCLC. Two of the ten patients (20%) developed second malignancies and died. The remaining patient died of pneumonia. The Cox regression analysis identified the PS and doxorubicin-containing regimens as important factors indicating improved survival. Combination regimens containing doxorubicin have, therefore, been found to be very effective in improving survival and achieving long-term survival.

Adult↗