Biomedical subjects

K Shimokata

Publications and source records attributed to K Shimokata.

At least 91 records · Page 5Linked to original sources

PubMed1997

A phase II study of carboplatin and prolonged administration of oral etoposide in patients with small-cell lung cancer.

Prolonged oral administration of etoposide may have a theoretical advantage over intravenous infusion, and carboplatin has a more favorable toxicity profile than cisplatin. A combination of carboplatin 300 mg/m2 and oral etoposide 40 mg/m2/day for 21 days was assessed in 74 (42 limited, 32 extensive disease) previously untreated patients with small-cell lung cancer. Response rate was 69% (CR 19%, PR 50%,) for limited disease and 72% (CR 9%, PR 63%) for extensive disease. Median response duration and overall survival was 6.6 and 10.1 months for limited disease, and 5.3 and 9.1 months for extensive disease, respectively. One-year and two-year survival was 36 and 10% for limited disease and 31 and 2% for extensive disease, respectively. The major toxicity was hematological with grade 4 or greater neutropenia in 36% and grade 4 thrombocytopenia in 16%, and one patient died of neutropenic fever. Non-hematologic toxicities were mild and grade 3 emesis was observed in 5% of patients. Carboplatin combined with 21-day oral etoposide showed only modest activity against small-cell lung cancer with high toxicity and did not merit further evaluation.

Administration, Oral↗

PubMed1997

[Chemotherapy in non-small cell lung cancer].

Recent results of combination chemotherapy for non-small cell lung cancer suggest modest survival benefits. Because combination chemotherapy can have severe side effects, it is reasonable to give chemotherapy when the patient is able to understand and accept the potential benefits and toxicities from such therapy. Recent randomized trials have shown survival benefit for chemotherapies before and after surgical resection. However, these have to be confirmed before they are recommended for general use. Because distant failure is common after radiation therapy for locally advanced non-small cell lung cancer, attempts have been made to improve survival by adding chemotherapy to radiation therapy. The randomized trials comparing radiation with or without combination chemotherapy suggest a strong rational for exploring the combined use of the most effective chemotherapy regimens with more effective thoracic radiation approaches.

Carcinoma, Non-Small-Cell Lung↗

PubMed1997

[State of the art: treatment of malignant pleural and pericardial effusions].

Symptomatic malignant pleural effusions should be treated systemic chemotherapy in chemo-sensitive tumors such as small cell lung cancer, breast cancer, lymphoma, or ovarian cancer. In other non-chemo-sensitive malignancies including non-small cell lung cancer, water-sealed tube drainage and pleurodesis is the standard treatment of choice in most of the cases. Drugs for instillation should be blomycin or OK-432 if commercially available. Instead of the former standard drug tetracycline, doxycycline has been frequently used. As we have no randomized trials, this drug awaits phase III trials. Talc slurry has been accepted and counted as one of the standard choices in the western countries, however, it usually needs general anesthesia and adverse effects are not negligible. As we have little experience on this modality, it should not be considered as a standard treatment. Other antitumor drugs instillation, thoraco-abdominal shunting, and pleuro-pneumonectomy should be considered experimental because of the lack of randomized trials. Symptomatic pericardial malignant effusion or cardiac tamponade is an oncologic emergency. We had better to treat the patient immediately by pericardiocentesis under the cardiac echographic guidance. It should be reserved to solve in randomized trials that the best method would be pericardiocentesis alone, percutaneous continuous drainage, pericardial fenestration, or pericardio-thoraco fenestration. Instillation of drug like doxycycline, OK-432, or bleomycin, lacks phase III comparison and it should be categorized as experimental.

Antineoplastic Agents↗

PubMed1997

Cytokines and local cellular immunity.

The characteristics and function of human lymphocytes at a morbid site were studied. Exudative-sensitized lymphocytes in tuberculous pleural fluid reacted to the specific antigen more effectively and produced higher titers of lymphokines including interferon gamma (IFN-gamma) and interleukin 2 (IL-2) than circulating lymphocytes. CD4+/CD8- T-cell subset is responsible for the antigen-specific IFN-gamma production in pleural T-lymphocytes of patients with tuberculous pleurisy. Thus, activated T-lymphocytes involve the production of lymphokines at the morbid site and they effectively exert local cellular immunity through the action of such lymphokines. Immunofluorescence study showed an increased production of inducible nitric oxide synthase (iNOS) and peroxynitrite in bacille de Calmette-Guérin (BCG)-inoculated human alveolar macrophages (AM). Reverse transcriptase-polymerase chain reaction methods also revealed the higher expression of iNOS-coding mRNA. Colony assay demonstrated that human AM effectively killed BCG in their cytoplasm. However, treatment of AM with NG-monomethyl-L-arginine monoacetate resulted in markedly reduced killing activity. These results clearly show that BCG-induced nitric oxide (NO) and its reactive product with the oxygen radical, peroxynitrite, could play an important role in BCG killing in human AM.

Cytokines↗

PubMed1997

Prognostic value of pleural effusion in patients with non-small cell lung cancer.

This study was performed to determine whether pleural effusion in patients with advanced non-small cell lung cancer (NSCLC) has a negative impact on survival. We evaluated 12 prognostic factors in 197 patients with stage IIIB or IV NSCLC. Each factor was dichotomized, and survival curves calculated by the Kaplan-Meier technique were compared using the log-rank test. The Cox proportional hazards regression model was used to confirm the significance of each prognostic factor selected by univariate analysis. We compared the survival times for stage IIIB with pleural effusion with those of stage IIIB without effusion and stage IV. To determine the impact of the cytological results of the effusion on survival, we compared the survival times for cytologically positive and negative effusions. Univariate analysis identified eight significant prognostic factors: pleural effusion, node status, stage, performance status, weight loss, hemoglobin, albumin, and lactate dehydrogenase. Pleural effusion was selected as a prognostic factor in the multivariate analysis, together with stage, performance status, albumin, and node status. Median survival times for stage IIIB without effusion, stage IIIB with effusion, and stage IV were 15.3, 7.5, and 5.5 months, respectively (P < 0.0001). Survival time for stage IIIB with effusion was significantly different from that of stage IIIB without effusion (P = 0.0129) but not from that of stage IV (P = 0.0797). Among patients with effusion, no significant difference in survival time was observed between cytologically positive and negative effusions. We conclude that pleural effusion in advanced NSCLC is a prognostic factor. Survival time for stage IIIB with pleural effusion is more similar to that of stage IV rather than that of stage IIIB without effusion.

Adult↗

PubMed1996

Somatic in vivo alterations of the DPC4 gene at 18q21 in human lung cancers.

The chromosome region 18q21 has been shown to be frequently deleted in lung cancers. Recent identification at this locus of DPC4, a gene whose inactivation has been suggested to play a role in pancreatic carcinogenesis, prompted as to examine whether it might also be altered in lung cancers. Two missense and 2-bp frameshift somatic mutations in DPC4 were detected among 42 lung cancer specimens taken directly from patients. DPC4 mutations, however, were not present in all lung cancers carrying l8q21 deletions. These findings suggest that DPC4 may play a role in a limited fraction of lung cancers and that another tumor suppressor gene may also exist in this chromosome region.

Base Sequence↗

PubMed1996

Aberrant hypermethylation at the bcl-2 locus at 18q21 in human lung cancers.

Accumulating evidence suggests that altered DNA methylation may play a role in the oncogenesis of human neoplasms, including lung cancer. The presence of aberrant hypermthylations at 3p, 9p, 11p, ad 17p, which are known to be hot spots for allele loss in lung cancers, is suggested to be a reflection of the existence of tumor suppressor genes in these chromosomal regions. In the present study, we investigated the methylation status of the Rb locus at 13q14 as well as that of the bcl-2 locus at 18q21 in 134 lung cancer specimens, representing all major histological subtypes. As a result, 18q21 was identified to be the fifth chromosomal region affected by frequent tumor-specific aberrant hypermethylation in lung cancers. The occurrence of aberrant hypermethylation at the bcl-2 locus at 18q21 was restricted to non-small cell lung cancers, and among non-small cell lung cancers, such epigenetic aberrations were observed most frequently in adenocarcinomas without any association with bcl-2 expression. Interestingly, allelic loss at the bcl-2 locus was also seen in 40% (7 of 17 informative cases) of adenocarcinomas; this frequency was also the highest among values for the various histological subtypes of lung cancers. These results suggest that aberrant hypermethylation at the bcl-2 locus may be a reflection of a putative tumor suppressor gene residing at 18q21, and aberrant hypermethylation might play a role in its inactivation. In contrast, altered methylation status of the Rb locus appears to be quite rare in lung cancers, if present at all.

Adenocarcinoma↗

PubMed1996

Types of methicillin-resistant Staphylococcus aureus associated with high mortality in patients with bacteremia.

Forty-seven strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated from 47 patients with bacteremia were analyzed by chromosomal DNA digestion pattern using pulsed-field gel electrophoresis and evaluated for serological coagulase type, enterotoxin type, and toxic shock syndrome toxin-1 production. The mortality rate was significantly higher in the older patients (> or = 51 years of age) than in the younger patients (< or = 50 years of age) (50% vs. 4%, p = 0.0007). Methicillin-resistant Staphylococcus aureus strains of serological coagulase type II were more likely to be associated with mortality in older patients than were strains of the other types (p = 0.037).

Adolescent↗

PubMed1996

Is there a circadian variation in plasma concentrations of etoposide given by prolonged continuous infusion?

The prolonged continuous infusion of low-dose etoposide is a new approach to treating cancer. Whether or not a circadian variation in the plasma levels of etoposide existed was investigated in nine patients with non-small-cell lung cancer. Etoposide was infused for 14 days and blood samples were obtained every 4 h for 1 day. There was no significant circadian variation, and the observed small within-day variations seemed to lack clinical significance.

Aged↗

PubMed1996

Pharmacodynamic modeling of prolonged administration of etoposide.

PURPOSE: A refined pharmacodynamic model for toxicity is necessary for successful adaptive control of the administration of an anticancer drug to avoid toxicity. We sought to establish a pharmacodynamic model of leukopenia in a 14-day administration of etoposide. METHODS: Pharmacokinetic data of 32 patients treated with etoposide infused over 14 days in a phase I study (20 patients) or in an adaptive control study (12 patients) were used to develop a model for the prediction of a leukocyte nadir count. The concentrations of both estimated unbound and total etoposide at steady state, as well as patient demographic factors, were included in linear and nonlinear models. The unbound fraction of etoposide was estimated using an equation based on serum albumin and total bilirubin. The efficacy of the models was evaluated in terms of correlation coefficient (r), mean predictive error (MPE) and root mean square error (RMSE). RESULTS: For both total and unbound drug concentration, a nonlinear model predicted leukopenia more precisely and with less bias than a linear model, and unbound drug explained more variability of leukopenia than total drug concentration in both linear and nonlinear models. The best model was a nonlinear model with three variables of unbound concentration, pretreatment leukocyte count and prior treatment (r = 0.76, MPE +/- SEM = 0.07 +/- 0.17 x 10(3)/microl, RMSE = 0.95 x 10(3) microl), which was better than the best linear model. CONCLUSIONS: The nonlinear model using unbound etoposide concentration explained the interpatient variability of leukocyte nadir count to a fairly large extent. Although the model provided useful information on the pharmacodynamics of etoposide, it was still imprecise and a more refined model is necessary for application to an adaptive control study.

Antineoplastic Agents, Phytogenic↗

PubMed1996

Adenosine deaminase isozymes in tuberculous pleural effusion.

Total adenosine deaminase (ADA) activity and its isozyme (ADA1 and ADA2) activities were measured in pleural effusions and serum samples from patients with tuberculosis and in those from patients with lung cancer as controls. To analyze the cellular source of ADA isozymes in tuberculous pleural effusions, ADA isozyme activities in CD2+ T lymphocytes purified from tuberculous pleural effusions and cultured human cell lines derived from hematopoietic tumors were measured. Tuberculous pleural effusions had a much higher ADA activity than cancerous effusions, and high ADA activity mainly originated from the increase in ADA2 activity. Further, total ADA activity in tuberculous pleural effusions decreased after antituberculosis treatment, because of the decrease in ADA2 activity. On the other hand, measurement of ADA and ADA isozyme activities in T lymphocytes purified from tuberculous pleural effusions and human hematopoietic cell lines showed dominant expression of ADA1 in total ADA activity. In conclusion, we found that ADA2 is a dominant component of tuberculous pleural effusions and that ADA1 is a major component of lymphoid cells. These results suggest that elevation of ADA activity in tuberculous pleural effusions does not always reflect the activation of cell-mediated immunity.

Adenosine Deaminase↗

PubMed1996

Comparison of DNA fingerprinting by PFGE and PCR-RFLP of the coagulase gene to distinguish MRSA isolates.

Staphylococcus aureus isolates were collected from epidemiologically unrelated clinical sources in Japan between 1991 and 1993. A total of 40 isolates, five each of eight coagulase types, were analysed by polymerase chain reaction (PCR) of the coagulase gene, PCR-restriction fragment length polymorphism (RFLP) after AluI digestion, and pulsed-field gel electrophoresis (PFGE) of chromosomal DNA after SmaI digestion. The efficiency of discrimination among the isolates increased in the order of PCR < PCR-RFLP < PFGE, yielding five, 13 and 31 different types, respectively. To assess the clinical use of these methods, 42 additional methicillin-resistant S. aureus (MRSA) isolates collected from 27 inpatients in a hospital were analysed. PFGE and PCR-RFLP were able to discriminate 11 and four types, respectively. PFGE analysis detected cross-infection between four postoperative patients in an intensive-care unit, and in six neonates in intensive care. We conclude that of the three methods tested, PFGE analysis currently allows the most effective discrimination of MRSA strains.

Bacterial Typing Techniques↗

PubMed1996

Role of basic amino acids in the cleavage of synthetic peptide substrates by mitochondrial processing peptidase.

Our recent experiments using model peptides of rat malate dehydrogenase (MDH) indicated that a proximal arginine and a distal basic amino acid are important for processing by mitochondrial processing peptidase (MPP). [Niidome, T., Kitada, S., Shimokata, K., Ogishima, T., and Ito, A. (1994) J. Biol. Chem. 269, 24719-24722]. To elucidate if the recognition elements apply to other precursor proteins, we analyzed cleavage of model peptides of human ornithine aminotransferase (OAT). Purified peptidase cleaved peptides that corresponded to N-terminal 1-25 and 3-25 at the correct site (Gly17-Val18) at nearly equal rates. Replacement of Arg16 (-2 position) with lysine or alanine reduced the processing efficiency by 95- and 380-fold, respectively. Either deletion from Met1 to Arg10 or replacement of the basic amino acids between them decreased the processing efficiency considerably. A peptide containing Arg7 in addition to Lys4 and Arg10 was more effective than the control peptide. However, a peptide with one and two consecutive basic amino acids in the distal region had a processing efficiency close to the control peptide. These results indicated that processing of OAT was enhanced by an increase in the number of basic amino acids with a suitable distance between them. In other respects, the processing signal of OAT was essentially the same as that of MDH.

Amino Acid Sequence↗

PubMed1996

Acceptability of patients with brain metastases for clinical trials of chemotherapy for metastatic non-small-cell lung cancer.

This study was conducted to determine whether patients with brain metastases from non-small-cell lung cancer (NSCLC) should be included in clinical trials of chemotherapy. Patients with metastatic NSCLC and good performance status were studied. The survival of patients with brain metastases was compared with that of patients without brain metastases. Of 100 eligible patients, 22 had brain metastases at diagnosis. The median survival time was poorer in patients with brain metastases than in other patients with metastatic NSCLC (96.5 vs. 181.5 days). However, the difference in survival was not significant on univariate analysis (p = 0.106). Multivariate analysis confirmed that the prognostic value of brain metastases was limited in this sample (p = 0.129). There was little difference in survival curves during the first 8 weeks. Patients with brain metastases who have good performance status and minimal neurologic symptoms can be observed for approximately 8 weeks in clinical trials to determine their response to chemotherapy. However, it is doubtful that patients with brain metastases would be eligible for phase III trials, in which survival is an endpoint.

Adult↗

PubMed1996

Detection of human cytomegalovirus DNA from allogeneic bone marrow transplant recipients with interstitial pneumonitis.

Interstitial pneumonitis (IP) due to human cytomegalovirus (HCMV) infection can kill patients who receive allogeneic bone marrow transplants (BMT). However, making a definitive diagnosis of HCMV-associated IP is difficult, except in pathologically defined cases. The authors tried to detect HCMV DNA amplified by the polymerase chain reaction with nonradioactive Southern blot analysis from paraffin-embedded lung tissue. Human cytomegalovirus DNA was detected in all of ten BMT recipients with IP and all of three non-BMT recipients with histologically diagnosed HCMV IP. Clinical diagnoses indicated that three of ten allogeneic BMT recipients had HCMV IP, and they showed amplified HCMV DNA despite the lack of histologic viral inclusions. However, HCMV DNA was not detected in 11 immunosuppressed patients with non-HCMV pneumonitis who were included as controls. These observations indicate that the polymerase chain reaction and Southern blot analysis used with lung tissue is more sensitive than histologic examination, and that these tests may be applicable to transbronchial lung biopsy specimens for the early specific diagnosis of HCMV IP. Further analysis of allogeneic BMT recipients showed that four patients who died of HCMV IP fewer than 90 days after BMT had higher quantities of HCMV DNA, whereas six patients who died of HCMV IP more than 90 days after BMT showed lower quantities of HCMV DNA. THis result suggests that HCMV IP in the late phase after MBT might not be attributable to active virus replication alone but rather to the immune response involved in the graft-versus-host reaction.

Base Sequence↗

PubMed1996

Therapeutic drug monitoring in 21-day oral etoposide treatment for lung cancer.

We aimed to determine whether or not therapeutic drug monitoring is applicable to 21-day oral etoposide treatment for lung cancer. As the starting dose, a 25-mg capsule of etoposide was taken orally three times daily (75 mg/body). To achieve the target concentration range of 1.0 to 1.5 micrograms/ml, the dose was changed to two (50 mg/body) or four (100 mg/body) times a day from day 5, depending on the mean concentration obtained on days 3 and 4 (Cbefore). The mean concentration was calculated by use of a limited sampling model we constructed previously. Among 26 courses in 15 patients, two patients experienced grade 4 leukopenia plus neutropenia, and one of them died on day 20. Because nausea/emesis prevented the planned dose escalation in one patient, we excluded two courses of this patient from the pharmacokinetic analysis of dose modification. Among 5 courses with dose reduction, the Cbefore of 1.7 +/- 0.1 (microgram/ml, mean +/- SE) was decreased to 1.3 +/- 0.2 after day 5 (Cafter). Among 7 courses with dose escalation, the Cbefore of 0.9 +/- 0.0 was increased to the Cafter of 1.2 +/- 0.1. Among the remaining 12 courses without dose modification, the Cbefore and the Cafter were 1.2 +/- 0.0 and 1.3 +/- 0.1, respectively. Hematologic toxicities tended to correlate with the drug concentration. TDM is thus applicable to oral etoposide given according to this schedule, and a larger study is now needed to confirm that the therapeutic efficacy is improved by introducing TDM.

Administration, Oral↗

PubMed1996

Therapeutic drug monitoring of etoposide in a 14-day infusion for non-small-cell lung cancer.

We investigated whether a constant plasma concentration could be obtained by the individualized administration of low-dose, prolonged-infusional etoposide. Etoposide was infused for 14 days at 40 mg/m2/day initially in patients with inoperable non-small-cell lung cancer. The infusion rate was modified based upon the etoposide concentration at 24 h following the initiation of the infusion (C24) to achieve a target concentration of 1.5 microgram/ml. We postulated that severe toxicities could be avoided by maintaining the steady-state concentration at less than 2 microgram/ml, while antitumor activity could be expected if the steady-state concentration was maintained at more than 1 microgram/ml. In a total of 21 courses in 12 patients, the mean etoposide dose was 35+/-6 mg/m2 daily. The C24 was 1.8+/-0.4 microgram/ml and ranged from 1.1 to 2.9 microgram/ml. Following dose modification, the mean concentration from 96 to 336 h (C mean) was 1.6+/-0.2 microgram/ml and ranged from 1.2 to 2.0 microgram/ml. The toxicities were well-tolerated except for one patient with WHO grade 4 leukopenia and neutropenia who developed infectious complications. There were no treatment-related deaths. Following dose modification, the inter-patient variability was decreased successfully. Although this pharmacologically-guided method needs to be validated using more patients, it could be used for therapeutic drug monitoring.

Aged↗

PubMed1996

Multifocal outbreaks of metallo-beta-lactamase-producing Pseudomonas aeruginosa resistant to broad-spectrum beta-lactams, including carbapenems.

A total of 3,700 Pseudomonas aeruginosa isolates were collected from 17 general hospitals in Japan from 1992 to 1994. Of these isolates, 132 carbapenem-resistant strains were subjected to DNA hybridization analysis with the metallo-beta-lactamase gene (blaIMP)-specific probe. Fifteen strains carrying the metallo-beta-lactamase gene were identified in five hospitals in different geographical areas. Three strains of P. aeruginosa demonstrated high-level imipenem resistance (MIC, > or = 128 micrograms/ml), two strains exhibited low-level imipenem resistance (MIC, < or = 4 micrograms/ml), and the rest of the strains were in between. These results revealed that the acquisition of a metallo-beta-lactamase gene alone does not necessarily confer elevated resistance to carbapenems. In several strains, the metallo-beta-lactamase gene was carried by large plasmids, and carbapenem resistance was transferred from P. aeruginosa to Escherichia coli by electroporation in association with the acquisition of the large plasmid. Southern hybridization analysis and genomic DNA fingerprinting profiles revealed different genetic backgrounds for these 15 isolates, although considerable similarity was observed for the strains isolated from the same hospital. These findings suggest that the metallo-beta-lactamase-producing P. aeruginosa strains are not confined to a unique clonal lineage but proliferated multifocally by plasmid-mediated dissemination of the metallo-beta-lactamase gene in strains of different genetic backgrounds. Thus, further proliferation of metallo-beta-lactamase-producing strains with resistance to various beta-lactams may well be inevitable in the future, which emphasizes the need for early recognition of metallo-beta-lactamase-producing strains, rigorous infection control, and restricted clinical use of broad-spectrum beta-lactams including carbapenems.

Blotting, Southern↗