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Biomedical subjects

K Nagai

Publications and source records attributed to K Nagai.

At least 91 records · Page 5Linked to original sources

p53 gene alteration in atypical epithelial lesions and carcinoma in patients with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is well known to be associated with lung cancer. Several atypical epithelial lesions are frequently observed in the fibrotic area in IPF patients, and they have been suspected to be related to lung carcinogenesis. Several studies have suggested that p53 protein accumulation and mutation occur in the early pathogenesis of squamous cell carcinoma of the lung, suggesting some abnormality of the p53 tumor-suppressor gene in interstitial lung diseases. To examine the cause of the high frequency of lung cancer in IPF, we examined the p53 changes in atypical epithelial lesions and carcinoma in patients with IPF by immunohistochemistry and mutational analysis. We examined 19 lung cancer patients with IPF who underwent surgical resection for lung cancer in our institute. Paraffin-embedded tissues were treated by microwave and stained with an anti-p53 antibody (RSP53) by the avidin-biotin-peroxidase complex method. Mutations in exons 5 through 8 of the p53 gene were also examined by polymerase chain reaction mediated single-strand conformation polymorphism (polymerase chain reaction-single-strand conformation polymorphism) analysis and DNA sequencing. p53 protein was immunohistochemically detected in 13 (62%) of 21 squamous cell carcinomas, 3 (60%) of 5 squamous metaplasia with atypia, 16 (54%) of 30 squamous metaplasia, and 1 (4%) of 26 other hyperplastic lesions. p53 mutation was detected in 12 (57%) of 21 squamous cell carcinomas, 2 (40%) of 5 squamous metaplasia with atypia, 7 (23%) of 30 squamous metaplasia, and 0 (0%) of 26 other hyperplastic lesions. In conclusion, there are frequent p53 gene alterations in squamous metaplasia, which is distributed in the peripheral zone of the fibrotic area in patients with IPF. The present findings might provide a clue to the molecular mechanisms underlying the high incidence of lung cancer, especially peripheral-type squamous cell carcinoma in IPF patients, and suggest that p53 gene alterations play an important role in the early stages of lung carcinogenesis in patients with IPF.

Aged↗

Pathologic N0 status in pulmonary adenocarcinoma is predictable by combining serum carcinoembryonic antigen level and computed tomographic findings.

OBJECTIVES: It is not clear whether lymphadenectomy has therapeutic benefit in non-small cell lung cancer management. To avoid unnecessary lymphadenectomy, we attempted to identify clinical or radiologic predictors of pathologic N0 disease in patients with peripheral adenocarcinoma. METHODS: From August 1992 through April 1997, 269 consecutive patients with peripheral adenocarcinoma who underwent major lung resection and systematic lymph node dissection were enrolled in this study. We reviewed their contrast-enhancement computed tomographic scans and recorded the maximum dimension of tumors both on pulmonary (pDmax) and on mediastinal (mDmax) window setting images, the largest dimension perpendicular to the maximum axis on both pulmonary (pDperp) and mediastinal (mDperp) window setting images, and the size of all detectable hilar-mediastinal lymph nodes. We defined a new radiologic parameter, tumor shadow disappearance rate (TDR), which is calculated with the following formula: TDR = 1 - (mDmax x mDperp)/(pDmax x pDperp). RESULTS: In multivariable analysis a lower serum carcinoembryonic antigen level and a higher tumor shadow disappearance rate were significant predictors of pathologic N0 disease. Lymph node size on computed tomographic scanning was not a significant predictor. Among 59 patients with a normal preoperative carcinoembryonic antigen level and a tumor shadow disappearance rate of 0.8 or more, 58 (98%) patients had pathologic N0 disease, and the other patient had pathologic N1 disease. CONCLUSIONS: Mediastinal lymph node involvement was not found in patients with a normal preoperative serum carcinoembryonic antigen level and a tumor shadow disappearance rate 0.8 or more. The patients who meet these criteria may be successfully managed with major lung resection without systematic mediastinal lymphadenectomy.

Adenocarcinoma↗

Effects of actinomycin D on fetal growth in rats.

OBJECTIVE: The goal of this study was to determine the effects of actinomycin D on fetal growth and prostaglandin dehydrogenase activity and to determine whether these effects could be obtained by administering extracts of fetal calf serum (SS-094). METHODS: Actinomycin D (7 microg/100 g body weight) was injected intraperitoneally on days 11 and 12 of pregnancy to induce growth restriction in rats. In another group, SS-094 was given (0.1 ml/100 g body weight) on days 12, 15, 17 and 19 of pregnancy, following the administration of actinomycin D. Placental prostaglandin dehydrogenase (PGDH) activity was measured on days 15 and 21 of pregnancy. Statistical analysis was performed by ANOVA and Dunnet's test. RESULTS: In the group injected with actinomycin D, fetal weight was significantly restricted (on day 15; p < 0.05; on day 21; p < 0.01), compared to the controls, and this restriction was successfully reversed by SS-094. PGDH activity in the placenta was significantly (p < 0.01) decreased in growth-restricted rats and remained low even after fetal weight recovered. CONCLUSIONS: Growth restriction in pregnant rats was successfully induced by actinomycin D, and SS-094 reversed this restriction. It does not seem that prostaglandin metabolism in the placenta is responsible for growth restriction.

Analysis of Variance↗

Single- and multi-step resistance selection study of gemifloxacin compared with trovafloxacin, ciprofloxacin, gatifloxacin and moxifloxacin in Streptococcus pneumoniae.

The ability of sequential subcultures in subinhibitory concentrations of gemifloxacin, trovafloxacin, ciprofloxacin, gatifloxacin and moxifloxacin to select resistant mutants was studied in 16 pneumococci [eight with ciprofloxacin MICs (mg/L) 0.25-1; four with 8-16; four with 16-32]. Subculturing was done 50 times, or until mutants with elevated MICs (> or = 4 x) to the selecting drug emerged. Subculturing in gemifloxacin selected six resistant mutants (gemifloxacin MICs 2 mg/L); trovafloxacin selected nine (trovafloxacin MICs 2-4 mg/L); ciprofloxacin selected 11 (ciprofloxacin MICs 8-128 mg/L); gatifloxacin selected 13; and moxifloxacin selected 12 (gatifloxacin or moxifloxacin MICs 2-16 mg/L). DNA sequencing showed that most mutants had mutations in ParC at Ser-79 or Asp-83 and in GyrA at Ser-81 or Glu-85; some mutants also had mutations in ParE or GyrB. Some new mutations were found in ParE or GyrB that have not yet been reported; GyrB mutation might be associated with moxifloxacin resistance. Both DNA gyrase and topoisomerase IV were thought to be the target of gemifloxacin; gemifloxacin also selected mutants with single modifications in gyrA, parC or parE alone among derived mutants by repeated exposure to subinhibitory concentrations of fluoroquinolones. In the presence of reserpine, most mutants had lower MICs of ciprofloxacin and gemifloxacin (4-32 x), and gatifloxacin (4-8 x), suggesting an efflux mechanism; none had lower trovafloxacin and moxifloxacin MICs. All quinolones tested selected for resistance; judicious use and proper dosing will be necessary to avoid resistance selection of newer broad-spectrum fluoroquinolones.

Anti-Infective Agents↗

Evaluation of PCR primers to screen for Streptococcus pneumoniae isolates and beta-lactam resistance, and to detect common macrolide resistance determinants.

Pneumococcal isolates (n = 148) from various countries (mostly from the USA) were tested by a primer set for PCR. Thirty-eight (86.4%) of the 44 penicillin G-susceptible isolates (MIC < or = 0.06 mg/L) had unaltered pbps, while six isolates (13.6%) had either one or two alterations in pbps. Of 47 penicillin G-resistant strains (MIC > or = 2 mg/L), 41 isolates (87.2%) had all three pbps altered, six isolates (12.8%) had altered pbp1a + 2x. Various combinations of altered pbp were seen in penicillin G-intermediate isolates. Prevalence of macrolide resistance genes mef(A) and erm(B) in isolates was clearly reflected by their MICs. All isolates were positive for lytA. The primers were useful for screening for Streptococcus pneumoniae and beta-lactam resistance, and for detection of common macrolide resistance determinants.

Anti-Bacterial Agents↗

A 7 mm lung adenocarcinoma with mediastinal involvement and lymphangiosis carcinomatosa: a case report.

We report a case of a 46-year-old man with a 7 mm lung adenocarcinoma with mediastinal nodal involvement and lymphangiosis carcinomatosa. The resected right middle lobe contained a 7 mm well-differentiated papillary adenocarcinoma and lymphatic vessels towards the hilum were severely involved. The disease was pathologically diagnosed as T1N2M0. Six months after the operation, malignant pleural effusion and multiple bone metastases developed and he died 21 months after the operation. This case indicates that even a very small-sized lung cancer, 1 cm or smaller, could be biologically highly malignant.

Adenocarcinoma↗

Phase II evaluation of protracted infusion of cisplatin and 5-fluorouracil in advanced squamous cell carcinoma of the esophagus: a Japan Esophageal Oncology Group (JEOG) Trial (JCOG9407).

BACKGROUND: Surgery for advanced esophageal carcinoma has its limits as regards aggressiveness and therapeutic effect, therefore effective multimodality treatment is required to obtain better survival. The objective of this study was to evaluate whether daily continuous infusion of CDDP could achieve a higher clinical response rate with less toxicity than its drip infusion in the previous phase II study that we had conducted. METHODS: Patients with primary extensive or relapsed esophageal carcinoma after esophagectomy, which had distant organ metastasis and histologically proven SCC, were eligible for this study. A dose of 20 mg/m(2) of cisplatin and 800 mg/m(2) of 5-fluorouracil was given by continuous infusion for 24 h on days 1-5. This treatment was repeated every 4 weeks for up to four cycles. A total of 36 men and six women with a median age of 64 (range 39-75) years were registered and 36 patients were eligible. RESULTS: The overall response rate of the registered patients was 33.3% (12/36) and the median response duration was 175 days. Median survival time was 201.5 days and the 1-year survival rate was 27.8%. Change from bolus to continuous infusion of cisplatin affected neither the type nor the degree of toxicity. CONCLUSION: Daily continuous infusion of cisplatin was not associated with higher response or lower toxicity than those seen with the high-dose bolus or multibolus treatment regimens. We conclude that this regimen in this setting is not worthy of further phase III trials. JEOG is now evaluating other drug combination regimens.

Adult↗

Reconstitution of the spliceosomal U1 snRNP from all recombinant subunits and its characterisation by ionspray Q-tof mass-spectrometry.

The first important step in pre-mRNA splicing is the recognition of the 5' splice site by the U1 snRNP. It consists of U1 snRNA and 10 protein subunits. We have reconstituted the U1 snRNP from all its ten proteins produced in E. coli and U1 snRNA transcribed in vitro. We have used nano spray time-of-flight (TOF) mass spectrometer in order to characterise the reconstituted U1 snRNP and its sub-assemblies which lack one of more subunits. The reconstituted U1 snRNP and its variants remained intact as multiply charged ions within the mass spectrometer and their mass was determined. By increasing collision energy subparticles are also observed. This method provides information not only about the stoichiometry of subunits within the complex but also about subsets of interacting proteins.

Protein Subunits↗

Factors affecting the difference between screening and home blood pressure measurements: the Ohasama Study.

OBJECTIVE: To establish the factors affecting the difference between screening and home blood pressure measurements. DESIGN: A cross-sectional study. SETTING: General population in a rural Japanese community, Ohasama, Japan. PARTICIPANTS: There were 1,789 community-based subjects aged > or =40 years, for whom blood pressure was measured at screening site (screening blood pressure) and at home (home blood pressure). RESULTS: Multiple stepwise regression analysis of all subjects demonstrated that screening pulse pressure was positively associated with the difference between screening and home blood pressure measurements for systolic blood pressure. Age, the use of antihypertensive medication, and smoking status were negatively associated with the difference between measurements of both systolic and diastolic blood pressure. CONCLUSION: We have demonstrated that age, smoking, antihypertensive medication, and screening pulse pressure are independent predictors of the magnitude of the difference between screening and home blood pressure measurements, suggesting that the necessity to consider these factors, for the detection of the subjects who may be inappropriately treated or misjudged following screening blood pressure measurements.

Adult↗

Usefulness of home blood pressure measurements in assessing the effect of treatment in a single-blind placebo-controlled open trial.

OBJECTIVES: Reproducibility of home blood pressure measurements (HBP), and the placebo effect on HBP, were examined to establish the number of subjects required in order to observe a significant antihypertensive effect of a drug for a comparative study between placebo and active treatment. METHODS: Reproducibility of HBP (n = 172 for systolic blood pressure and n = 137 for diastolic blood pressure) and the placebo effect on HBP (n = 35 for systolic and n = 42 for diastolic blood pressure) were examined using a semi-automatic electronic device on untreated hypertensive subjects during 21 consecutive days of measurements. From these two studies, the number of subjects required in order to observe a significant antihypertensive drug effect was assessed. In both studies, measurements from the first 3 days were excluded from the analysis. RESULTS: Reproducibility, defined as the difference between the initial 5 day average (days 4-8) and the last 5 day average (days 17-21) was -1.9 +/- 7.0/-1.4 +/- 4.8 mmHg (mean +/- SD), indicating high reproducibility with a minimal regression to the mean effect. A placebo was administered after the 8 day run-in period. The difference between the initial 5 day average (days 4-8) and the last 5 day average (days 17-21) was compared. The mean difference was 1.1 +/- 6.2/0.2 +/- 5.7 mmHg, suggesting that there was a minimal, if any, placebo effect. As determined by the power calculations, based on the standard deviations of the tests for reproducibility and the placebo effect, nine of 13 subjects are required to show that a 9/5 mmHg decrease in systolic HBP/diastolic HBP (50% of estimated effective decrease in systolic HBP/diastolic HBP according to the guidelines for clinical trials in Japan) is statistically significant CONCLUSIONS: The results suggest that the HBP measurement is highly reproducible and that there is a minimal, if any, placebo effect. These characteristics of HBP contribute to minimizing the number of subjects necessary for assessment of antihypertensive drug effects in comparative studies between an active treatment and placebo.

Adult↗

Aldosterone synthase gene (CYP11B2) C-334T polymorphism, ambulatory blood pressure and nocturnal decline in blood pressure in the general Japanese population: the Ohasama Study.

OBJECTIVE: The C-344T polymorphism in the 5'-flanking region of the aldosterone synthase (CYP11B2) gene has been suggested to be associated with hypertension and disturbed circadian blood pressure (BP) rhythm through its effect on aldosterone synthesis. However, previous findings on this topic have been inconsistent. DESIGN: A cross-sectional study. SUBJECTS AND METHODS: We investigated the CYP11B2 C-344T genotype in 802 subjects, aged 40 and over, in a Japanese community, who gave written informed consent and were monitored for 24 h ambulatory BP. RESULTS: The frequencies of the CC, CT, and TT genotypes in these Japanese subjects were 0.14, 0.44, and 0.42, showing a higher frequency of the T allele (0.64) than in Caucasians. Although there was no significant difference in 24 h ambulatory BP levels among the genotypes, the nocturnal decline in BP was significantly greater in the CC homozygous subjects than in other subjects (P = 0.0065 for systolic and P = 0.031 for diastolic decline in nocturnal BP). Detailed analyses demonstrated that this association was significant only in aged (60 years and over) or male subjects. The prevalence of previous cardiovascular disease was significantly less in these subjects with the CC genotype than in those with the TC and TT genotypes, although age, body mass index, male gender, smoking, use of alcohol and antihypertensive medication did not differ among the three genotypes. There was no significant difference among the three genotypes in biochemical and hormonal parameters. CONCLUSION: Although the C-344 T polymorphism of CYP11B2 did not directly influence the level of 24 h BP, the CC genotype was associated with decreased nocturnal BP in elderly or male Japanese. Since prevalence of previous cardiovascular disease was significantly less in homozygous CC subjects, greater nocturnal BP decline in this genotype appears to be beneficial in the circadian BP rhythm.

Aged↗

Predictive values of automated blood pressure measurement: what can we learn from the Japanese population - the Ohasama study.

BACKGROUND: Measurements of ambulatory blood pressure (ABP) and of home blood pressure (HBP) as an adjunct to casual/clinic blood pressure (CBP) measurements are currently widely used for the diagnosis and treatment of hypertension. We have monitored a rural cohort of people from the population of Ohasama, Japan, with respect to their prognosis and have previously reported that ABP and HBP are superior to CBP for the prediction of cardiovascular mortality. One reason that CBP is a poor predictor of prognosis is that it incorporates several biases, including the white-coat effect. METHODS AND RESULTS: We examined the prognostic significance of white-coat hypertension for mortality and found that the relative hazard for the overall mortality of patients with white-coat hypertension was significantly lower than that for true hypertension. Short-term blood pressure variability has recently attracted attention as a cause of target-organ damage and cardiovascular complications. Our results confirmed that short-term blood pressure variability (as measured every 30 min) was independently associated with cardiovascular mortality. In addition, research has recently focused on isolated systolic hypertension and pulse pressure as independent risk factors for poor cardiovascular prognosis. The Ohasama study also clearly demonstrated that isolated systolic hypertension and increased pulse pressure, as assessed by HBP, were associated with an increase in the risk of cardiovascular mortality. Circadian blood pressure variation is characterized by a diurnal elevation and a nocturnal decline in blood pressure. We therefore compared morbidity from stroke between dippers (subjects who show an ordinal nocturnal dipping of blood pressure) and non-dippers (those with a diminished nocturnal dipping or nocturnal elevation of blood pressure [inverted dippers]) in the Ohasama study. The incidence of stroke increased with an increased length of observation in dippers using antihypertensive medication but not in non-dippers using antihypertensive medication. In contrast, the relative hazard for mortality increased in non-dippers and inverted dippers. These results suggest a cause-and-effect relationship for both dippers and non-dippers. CONCLUSION: The Ohasama study showed that the level and variability of hypertension as assessed by ABP and HBP are independent predictors of cardiovascular mortality. It also demonstrated an independent association between the prognosis of hypertension and each component of ABP and HBP, indicating the prognostic significance of these blood pressure measurements.

Bias↗

Frameshift mutations at mononucleotide repeats in RAD50 recombinational DNA repair gene in colorectal cancers with microsatellite instability.

To identify additional genes targeted for microsatellite instability (MSI), we search for human genes which contain mononucleotide repeats in their coding region, selected 7 genes (RAD50, DNA-PKcs, FLASH, Apaf-1, XPG, CtIP, and MLSN1), and analyzed frameshift mutations in them. Here we report that 60% (3 out of 5) of human colorectal cancer cell lines exhibiting a high frequency of MSI (MSI-H) and 46% (6 out of 13) of MSI-H primary colorectal tumors had mutations in the (A)9 repeat of RAD50 recombinational repair gene. In contrast, no frameshift mutations were found in any of the 5 MSI-negative colorectal cancer cell lines, 8 colorectal tumors exhibiting a low frequency of MSI (MSI-L), or 28 MSI-negative colorectal tumors. No mutations were found in the mononucleotide repeats of 6 other genes, even in MSI-H cancers. These results suggest that RAD50 frameshift mutations may play a role in the tumorigenesis of MSI-H colorectal cancers.

Colorectal Neoplasms↗

CPT-11 may provide therapeutic efficacy for esophageal squamous cell cancer and the effects correlate with the level of DNA topoisomerase I protein.

CPT-11 is a potent anti-cancer drug and a specific inhibitor of DNA topoisomerase I (Topo I). In this study, we aim to evaluate the effects of CPT-11 on esophageal squamous cell cancers (ESCC) and to determine the correlation between the effects and the levels of Topo I expression. We examined the growth-inhibitory effect caused by SN-38, an active metabolite of CPT-11, in 14 human ESCC cell lines established from 10 primary and 4 metastatic lesions. CPT-11 was considered effective against 5 cell lines from primary lesions and one from metastatic lesions, and thus may show therapeutic efficacy against both primary and metastatic ESCC tumors. Although Topo I mRNA levels in these 14 ESCC cell lines, as quantitated by northern blot analysis, showed no correlation with the IC(50) values, Topo I protein levels, as quantitated by western blot analysis, showed an inverse correlation with the IC(50) values. Topo I protein levels could be an indicator of sensitivity to CPT-11. We also determined Topo I protein levels in 40 ESCC tumors and matched normal mucosae. Thirty-four tumors showed 1.2 - 22.3-fold increases in Topo I levels. Two patients receiving pre-operative chemotherapy and one receiving radiotherapy exhibited increased Topo I protein levels in their tumor lesions. It appeared that CPT-11 could provide selective therapeutic efficacy against ESCC tumors. CPT-11 may be effective for the treatment of metastatic ESCC tumors and as a second-line anti-cancer drug for ESCC.

Blotting, Western↗

Activities of a new fluoroketolide, HMR 3787, and its (des)-fluor derivative RU 64399 compared to those of telithromycin, erythromycin A, azithromycin, clarithromycin, and clindamycin against macrolide-susceptible or -resistant Streptococcus pneumoniae and S. pyogenes.

Activities of HMR 3787 and RU 64399 were compared to those of three macrolides, telithromycin, and clindamycin against 175 Streptococcus pneumoniae isolates and 121 Streptococcus pyogenes isolates. HMR3787 and telithromycin were the most active compounds tested against pneumococci. Telithromycin and RU 64399 were equally active against macrolide-susceptible (MICs, 0.008 to 0.06 microg/ml) and -resistant S. pyogenes isolates, but HMR 3787 had lower MICs for ermB strains.

Anti-Bacterial Agents↗

Atypical adenomatous hyperplasia of the lung: a clinicopathological study of 118 cases including cases with multiple atypical adenomatous hyperplasia.

BACKGROUND: Atypical adenomatous hyperplasia (AAH) of the lung is a putative precursor lesion of adenocarcinoma, according to many immunohistochemical and genetical studies, but few clinicopathological studies on a large number of cases have been reported. The aim of this study was to clarify the clinicopathological characteristics of lung cancer patients with AAH lesions. METHODS: A retrospective study was carried out on 508 consecutive primary lung cancer patients operated on at National Cancer Center Hospital East. The relationship between the number and location of AAH lesions and the clinicopathological features of the lung cancer patients was analysed statistically. RESULTS: A total of 311 AAH lesions were found in 118 (23.2%) of the 508 cases. AAH lesions were detected in 121 of 572 lobes examined, usually in both upper lobes, and occurred most frequently in patients with adenocarcinoma (OR 2.97; 95% CI 1.82 to 4.85). AAH lesions were more frequently detected in patients with multiple primary carcinomas than in those with a single carcinoma (OR 3.06; 95% CI 1.56 to 6.00). The presence of AAH lesions was not significantly correlated with sex, age, smoking status, familial history of malignancy, or preceding malignancy. Patients with multiple AAH lesions were found to have a significantly higher frequency of preceding malignancies. CONCLUSIONS: The present study highlights the clinicopathological characteristics of AAH lesions, showing them to be significantly associated with both adenocarcinoma and multiple primary carcinoma of the lung and suggesting common factors in the histogenesis of multiple AAH lesions and preceding malignancy.

Adenomatosis, Pulmonary↗