Pharmacokinetics of 5-fluorouracil in elderly Japanese patients with cancer treated with S-1 (a combination of tegafur and dihydropyrimidine dehydrogenase inhibitor 5-chloro-2,4-dihydroxypyridine).

S-1 is an oral anticancer agent that combines tegafur, a prodrug of 5-fluorouracil (5-FU), and 5-chloro-2,4-dihydroxypyridine (CDHP), an inhibitor of dihydropyrimidine dehydrogenase. We examined the effects of aging on the pharmacokinetics of the components of S-1. The median area under the concentration-time curve (AUC) of active 5-FU did not significantly differ between 10 patients 75 years or older and 53 patients younger than 75 years (P = 0.598, Mann-Whitney U test). It is interesting to note that the median oral clearance of tegafur in patients 75 years or older was significantly lower than that in patients younger than 75 years (P = 0.011). Furthermore, the median AUC of CDHP was significantly higher in patients 75 years or older than in those younger than 75 years (P = 0.004). This effect was caused by reduced renal function in the elderly, because CDHP is excreted in the urine by glomerular filtration. The opposing effects of aging on the oral clearance of tegafur and the AUC of CDHP may offset each other, leading to unchanged systemic exposure of 5-FU.

Fixed dosing and pharmacokinetics of S-1 in Japanese cancer patients with large body surface areas.

BACKGROUND: S-1 is an oral anticancer agent that combines tegafur (FT) with 5-chloro-2,4-dihydroxypyridine (CDHP) and potassium oxonate. The recommended initial dose of S-1 is 120 mg/day for patients with a body surface area (BSA) of > or =1.5 m(2) in Japan. METHODS: We examined the effects of using this fixed dose on the pharmacokinetics of FT, CDHP, and active 5-fluorouracil (5-FU) on the basis of actual BSA. The pharmacokinetics was compared between patients with a BSA of 1.5-1.75 m(2) and those with a BSA of > or =1.75 m(2). RESULTS: The median areas under the time-concentration curves (AUCs) of 5-FU and CDHP were significantly lower in patients with a BSA of > or =1.75 m(2) than in those with a BSA of 1.5-1.75 m(2) (P = 0.005 and 0.006, respectively; Mann-Whitney U-test). There was no difference between the groups in the median AUC of FT. CONCLUSION: Systemic exposure to 5-FU is significantly lower in Japanese cancer patients with a large BSA of >1.75 m(2) who received the recommended fixed dose of S-1.

Phase I/II study of oxaliplatin with oral S-1 as first-line therapy for patients with metastatic colorectal cancer.

Two phase II studies of S-1 monotherapy have shown promising response rates (RR) of 35-40% with good tolerability in patients with untreated metastatic colorectal cancer. To investigate the usefulness of S-1 plus oxaliplatin (SOX) as an alternative to infusional 5-fluorouracil/leucovorin plus oxaliplatin, the recommended dose (RD) of SOX was determined, and its safety and preliminary efficacy were evaluated in a phase I/II study. Oxaliplatin was administered at a dose of 100 mg m(-2) (level 1) or 130 mg m(-2) (level 2) on day 1, and S-1 (80-120) was given twice daily for 2 weeks followed by a 1-week rest. This schedule was repeated every 3 weeks. Level 2 was determined to be the RD. For the 28 patients who received the RD, the median treatment course was 6.5 cycles (2-14), RR of 50% (1 CR and 13 PR: 95% CI 31-69%), with a median progression-free survival of 196 days. Survival rate (1 year) was 79%. Peripheral neuropathy was observed in all patients but with no functional disorders. Major grade 3 or 4 adverse reactions at the RD were neutropaenia (14%), thrombocytopaenia (28%), and diarrhoea (3%). SOX regimen is effective and easily manageable without central vein access.

Factors affecting the pharmacokinetics of CPT-11: the body mass index, age and sex are independent predictors of pharmacokinetic parameters of CPT-11.

This study was conducted to describe the relationship between pharmacokinetics of CPT-11 and its active metabolite SN-38, and clinical values with special emphasis on the influence of relative weight referring to the appropriateness of a conventional dose adjustment method by body surface area (BSA). Thirty-six patients received 100 mg/m2 of CPT-11 intravenously over 90 min. Body Mass Index (BMI) was used as a measure of relative weight which is calculated from the equation: BMI=weight(kg)/[height(m)]2. The area under the concentration-time curve (AUC) of CPT-11 was significantly correlated with sex, age, poorer creatinine clearance and indocyanine green retention test (ICG). The peak plasma concentration (Cmax) of CPT-11 was significantly correlated with sex a larger BMI, BSA and age. The AUC of SN-38 was significantly correlated with ICG. The volume of distribution at steady state of CPT-11 inversely correlated with BMI. Multiple regression analysis revealed that the best fitting model with significant independent predictors for AUC of CPT-11 included age and sex (F=6.93, R2=0.29). That of Cmax of CPT-11 included sex and BMI (F=8.96, R2=0.35). The only independent predictor of AUC of SN-38 was ICG (F=7.75, R2=0.19). These results indicated that several factors affect pharmacological behaviors of CPT-11 even in patients with normal organ functions. The dose modification method based solely on BSA is not sufficient to reduce interpatient variability of cancer chemotherapy. The influence of relative weight, sex and age on pharmacokinetics/pharmacodynamics should be taken into consideration in every pharmacological approach to establish the ideal dose modification method.

Quantitation of DNA damage by an aldehyde reactive probe (ARP).

DNA is constantly damaged by endogenous and environmental agents. Abasic sites representing a major class of DNA damage can be quantitated by an ELISA-like assay using an aldehyde reactive probe (ARP). It is shown that oxidative pyrimidine lesions can be also quantitated by the ARP assay in combination with the treatment with endonuclease III.

Frequent allelic loss/imbalance on the long arm of chromosome 21 in oral cancer: evidence for three discrete tumor suppressor gene loci.

Frequent allelic imbalances including loss of heterozygosity (LOH) and microsatellite instability (MI) on the long arm of chromosome 21 (21q) have been found in several types of human cancer. This study was designed to identify tumor suppressor locus (or loci) associated with oral squamous cell carcinoma (SCC) on 21q. Among 38 patients with oral SCC tested, 15 (44%) of 34 informative cases showed LOH at one or more loci. Deletion mapping of these 15 tumors revealed three discrete commonly deleted regions on the chromosome arm. A minimal region with frequent LOH was found at the marker D21S236 mapped on 21q11.1. Another region of frequent deletion was identified between markers D21S11 and D21S1436 on 21q21, and a further commonly deleted region was found at D21S1254 on 21q22.1. In addition, we have detected MI on the chromosome arm in our oral SCC samples with significant correlation with tumor stage. Thus, our results strongly suggest that allelic imbalances on 21q may be involved in the development of oral SCC; and that at least three different putative tumor suppressor genes contributing to the pathogenesis of this disease are present on 21q.

Acquisition and transfer of sentence construction in autistic students: analysis by computer-based teaching.

In this study, we examined the conditions necessary to construct appropriate sentences in three autistic students using computer-based training and testing procedure. In Experiment 1, when a picture was presented on the computer display as a sample stimulus, the student was required to construct an appropriate sentence with five words. After training with three stimuli, each student could construct the correct sentence for 24 untrained stimuli. Appropriate vocal responses also emerged. In Experiment 2, the appropriate use of particles, which specify the subject and the object, was acquired by particle choice or sentence construction training. The rule was transferred to untrained stimuli and writing response. These results are discussed in terms of applicability of computer-based training for establishing appropriate sequential responding and particle usage in autistic students.

Unsaturated glucuronyl hydrolase of Bacillus sp. GL1: novel enzyme prerequisite for metabolism of unsaturated oligosaccharides produced by polysaccharide lyases.

The bacterium Bacillus sp. GL1 assimilates two kinds of heteropolysaccharides, gellan and xanthan, by using extracellular gellan and xanthan lyases, respectively, and produces unsaturated saccharides as the first degradation products. A novel unsaturated glucuronyl hydrolase (glycuronidase), which was induced in the bacterial cells grown on either gellan or xanthan, was found to act on the tetrasaccharide of unsaturated glucuronyl-glucosyl-rhamnosyl-glucose produced from gellan by gellan lyase, and the enzyme and its gene were isolated from gellan-grown cells. The nucleotide sequence showed that the gene contained an ORF consisting of 1131 base pairs coding a polypeptide with a molecular weight of 42,859. The purified enzyme was a monomer with a molecular mass of 42 kDa and was most active at pH 6.0 and 45 degrees C. Because the enzyme can act not only on the gellan-degrading product by gellan lyase, but also on unsaturated chondroitin and hyaluronate disaccharides produced by chondroitin and hyaluronate lyases, respectively, it is considered that the unsaturated glucuronyl hydrolase plays specific and ubiquitous roles in the degradation of oligosaccharides with unsaturated uronic acid at the nonreducing terminal produced by polysaccharide lyases.

[Treatment for advanced colorectal carcinoma with 5-fluorouracil plus low-dose leucovorin].

From July 1992 to May 1996, 16 patients with non-curative postoperative or recurrent colorectal carcinomas were treated with 5-fluorouracil (5-FU) plus leucovorin (LV) systemic chemotherapy. LV was given at a dose of 20 mg/m2/d immediately followed by 5-FU at 370 mg/m2/d. LV was given by rapid intravenous (i.v.) injection and 5-FU by rapid or drip i.v. for 5 consecutive days. Courses were repeated once every 4 weeks for two months and then once every 5 weeks. All patients took 3 or more courses. The toxicity was tolerable, but one patient needed hospitalization because of severe gastro-intestinal toxicity. We observed 3 PR cases, no CR and an overall response rate of 19%. The response duration was 6 to 8 months, averaging 7.3 months, and median survival was 12 months. It was possible to perform this chemotherapy on an outpatient basis, so we think this chemotherapy is superior to in-hospital chemotherapy considering the issue of quality of life. However, the response rate was low and its duration was short. We must investigate chemotherapy further with new and more powerful chemical modulations to increase the response rate and to prolong the response duration.

Allelic loss on the short arm of chromosome 8 in oral squamous cell carcinoma.

Allelic deletions on the short arm of chromosome 8 (8p) are frequent events in many different types of malignant tumors, including head and neck tumors and oropharyngeal cancers. These regions are thought to harbor tumor suppressor genes. However, there has been no detailed analysis of loss of heterozygosity (LOH) on the chromosome arm 8p in oral squamous cell carcinoma (SCC). In order to estimate details of 8p loci involved in oral SCC, 32 patients with oral SCCs were examined for the LOH state 8p by PCR-LOH assay using 14 microsatellite markers. Based on our results a detailed deletion map of 8p showed LOH in at least one of the loci tested in 62.5% (20 of 32) of patients; and microsatellite instability (MI) was observed in 50% (16 of 32). The frequent LOH on this chromosome arm was identified at D8S87 and D8S258, mapped on 8p12 and 8p22, respectively. Fisher's exact test revealed no significant statistical correlation between the incidence of LOH or MI and clinicopathological features. Our observations indicate that the short arm of chromosome 8 may play a role in the pathogenesis of oral SCC; and that the two loci identified in this study may be tumor suppressor gene loci on 8p.

Localization of a novel tumor suppressor gene loci on chromosome 9p21-22 in oral cancer.

Allelic imbalance or loss of heterozygosity (LOH) studies have been used to identify regions on chromosomes that may contain putative tumor suppressor genes. Deletions of chromosome 9 regions have been observed at high frequency in many other types of sporadic tumor, whereas in oral cancer no decisive information about the allelic loss on chromosome 9 has been reported. To provide detailed understanding of the genetic alterations in oral cancer, 24 highly polymorphic markers mapped on chromosome 9 were used to examine 34 cases of oral squamous cell carcinoma (SCC). LOH was detected in 18 (53%) of 34 informative samples at one or more loci examined. On the basis of our results, three commonly deleted regions were identified and a detailed deletion map was constructed. One of the novel regions was on 9p22, where a tumor suppressor gene, interferon a cluster (IFNA) gene, was identified before. Another region was D9S157 locus at 9p22, telomeric to IFNA locus and p15/16 genes, and the third was located on 9p21 of the D9S104 locus, centromelic to methylthioadenosine phosphorylase (MTAP) gene and p15/16 genes. Thus, our data suggest that, except for p15/16 and MTAP gene, there were at least two candidate tumor suppressor genes located at chromosome 9p, and that the alteration of these genes is associated with the tumorigenesis of oral SCC.

[Levofloxacin concentrations in serum, sputum and lung tissue: evaluation of its efficacy according to breakpoint].

The levels of levofloxacin (LVFX) in the serum, sputum and lung tissue were measured by a high-performance liquid chromatography method, and the penetration ratio of LVFX into respiratory tissue was investigated. The subjects of this study were 23 patients under pulmonectomy or brochoscopy. LVFX at the dose of 200 mg was given orally and specimens were collected as follows; serum at 2, 3 and 5 hours after, sputum at 2 hours after, and lung tissue at 3 and 5 hours after the administration, respectively. The mean level of LVFX in lung tissue at 3 hours was 3.91 +/- 2.33 micrograms/g, and those in sputum and in serum at 2 hours were 0.71 +/- 0.63 and 2.08 +/- 1.01 micrograms/ml, respectively. A very strong correlation was demonstrated between the level of LVFX in lung tissue and that in serum (p < 0.0001), but correlation between those in sputum and in serum was not significant. The penetration ratio of LVFX into lung tissue was 217.2% and that into sputum was 4.05%. Based on the results of this study, the breakpoints (BPs) of LVFX for pneumonia and chronic respiratory tract infections were calculated to be 4 micrograms/ml and 1 microgram/ml, respectively. It was concluded that penetration of LVFX into lung tissue was satisfactory, and the tissue level of LVFX exceeded greatly the MIC90s against the typical pathogenic bacteria of respiratory tract infections. Taking the excellent BP for pneumonia, 4 micrograms/ml, into consideration, it was thought that LVFX is an effective antibacterial agent against pneumonia and other respiratory tract infections.

Establishment of a new human megakaryoblastic cell line, CMY, with chromosome 17p abnormalities.

A new megakaryoblastic cell line CMY was established from a Down's syndrome patient suffering from acute megakaryoblastic leukemia. The karyotypes of CMY showed deletion of chromosome 17 or the translocation of 17p, whereas the blasts of the patient did not reveal these abnormalities of chromosome 17 by conventional karyotype analysis. Blasts of the patient failed to respond to chemotherapy and complete remission could not be attained. The abnormalities of 17p became progressively predominant in the patient. These results suggest that the blasts of a minor clone which had the abnormalities of chromosome 17p might have existed in the patient from the beginning and CMY was established from the minor clone. Investigation of p53 gene by PCR-SSCP analysis revealed that blasts of the patient showed normal patterns, while CMY showed an abnormally migrating band in exon 5 alone. This result suggests that another novel oncogenic factor(s) besides p53 might be present on chromosome 17p and other tumor suppresser genes need to be studied.

Bradycardia induced by irinotecan: a case report.

Irinotecan chloride (CPT-11) is a new semi-synthetic camptothecin analogue which has encouraging antitumor activity against various malignancies. The major and unique toxicity of CPT-11 is diarrhea. Cardiovascular toxicity is rare and has not been found in clinical trials performed in Japan except for a very few cases of insignificant tachycardiac arrhythmia. We report a case of a 69-year-old man with recurrent colon cancer who suffered from bradycardia induced by infusion of CPT-11. Other toxicities including hematological toxicity and diarrhea were mild. Pharmacokinetic analysis using a limited sampling model revealed that the occurrence of bradycardia did not correlate with the excess of drug exposure. Although all of the cholinergic actions reported in the literature were mild, cardiotoxicity may come to be a clinically significant problem. If the events were examined more thoroughly, the cholinergic effect may be discovered more frequently. To administer CPT-11 safely needs meticulous monitoring not only for hematological toxicity and diarrhea but also for other cholinergic actions including bradycardia.

Evidence of multi-step oncogenesis of oral squamous cell carcinoma.

We examined biopsy samples from one oral cancer and three precancerous lesions of the tongue of an 81-year old woman by polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and sequence analyses using 18 oligonucleotide primer pairs of adenomatous polyposis coli (APC) gene and 5 primers of p53 gene. Normal tongue epithelium adjacent to lesions was used as a control. The four lesions harbored the common mutation of APC gene that was not detected in the control. At codon 1621 in exon 15 of the APC gene there was a C to G substitution resulting in serine (TCA) to stop codon (TGA). No mutation of p53 gene was detected in any samples of the control and three precancerous lesions of the tongue. On the other hand, an A to G substitution at codon 170 in exon 5 of p53 gene resulting in glutamic acid (ACG) to glycine (GCG) was detected in the DNA of her tongue cancer. These results may suggest that the four lesions have the same origin, and that multi-step oncogenesis had occurred, the APC gene alteration being one of the early events in the process of tumorigenesis and p53 gene alteration involved in the late events.

The influence of relative body weight on toxicity of combination chemotherapy with cisplatin and etoposide.

PURPOSE: This study was conducted to determine whether there was any relationship between the adverse toxicity of combination chemotherapy and clinical values including age, sex, creatinine clearance (Ccr), body surface area and relative body weight. METHODS: Cisplatin at a dose of 80 mg/m2 on day 1 and etoposide at a dose of 100 mg/m2 on days 1, 2 and 3 were given to 42 consecutive patients with solid tumors. All patients had normal major organ function and received uniform hydration therapy. RESULTS: Body Mass Index as a measure of relative body weight was inversely correlated with the percentage decrease in white blood cells (P = 0.0681) and platelet count (P = 0.0115). Body surface area was also inversely correlated with leukopenia (P = 0.0171) and thrombocytopenia (P = 0.0058). In contrast, age, sex and Ccr had no significant relationship with adverse toxicity. CONCLUSIONS: It is concluded that dose adjustment of combination chemotherapy with cisplatin and etoposide according to age or ideal body weight is not appropriate and that a conventional dose modification method based solely on body surface area is probably not sufficient to reduce interpatient variability of cancer chemotherapy. A pharmacokinetic and pharmacodynamic study of combination chemotherapy is warranted to establish the ideal dose modification method.

Allelic loss on chromosome 22 in oral cancer: possibility of the existence of a tumor suppressor gene on 22q13.

In order to understand the detail of genetic alternation on chromosome 22, we performed polymerase chain reaction analysis of microsatellite polymorphisms corresponding to 13 loci on chromosome 22. We examined 33 primary carcinoma tissues, 5 metastatic tissues and corresponding normal tissues. We detected microsatellite instability (MI) in 14 (42.4%) of 33 cases in this study. Loss of heterozygosity (LOH) was observed in at least one locus in 24 (72. 7%) of the 33 cases. Among the loci examined, LOH was restricted to D22S274 on chromosome 22q13 in 11 (40.7%) of 27 informative cases. No significant correlation between histological differentiation and LOH was observed. These observations suggest that the incidence of LOH at chromosome 22q is high and is associated with the carcinogenesis of oral squamous cell carcinoma (SCC). The D22S274 locus may play an important role in the development of oral SCC and be the site harboring a putative tumor suppressor gene.

Localization of a tumour-suppressor gene associated with human oral cancer on 7q31.1.

To search for the existence of a tumour-suppressor gene (TSG) associated with oral squamous cell carcinoma (SCC), PCR analysis of microsatellite polymorphisms corresponding to 14 loci which map to chromosome 7q21.3-qter was performed to screen 35 patients with oral SCC for loss of heterozygosity (LOH). LOH was observed in at least one of the loci in 19 of 34 (55.9%) informative cases. Among the loci tested, frequent LOH was restricted at D7S522 on chromosome 7q31.1, which was measured within 1 cM. Furthermore, we detected microsatellite instability (MI) in 11 of 35 (31.4%) cases tested. Our observations indicate that alterations of chromosome 7q are associated with oral SCC tumorigenesis and that 7q31.1 might harbour at least one putative TSG.

Functional analysis of an ascidian homologue of vertebrate Bmp-2/Bmp-4 suggests its role in the inhibition of neural fate specification.

The ascidian tadpole larva is thought to be close to a prototype of the ancestral chordate. The vertebrate body plan is established by a series of inductive cellular interactions, whereas ascidians show a highly determinate mode of development. Recent studies however, suggest some roles of cell-cell interaction during ascidian embryogenesis. To elucidate the signaling molecules responsible for the cellular interaction, we isolated HrBMPb, an ascidian homologue of the vertebrate bone morphogenetic protein (BMP) gene, from Halocynthia roretzi. The amino acid sequence of HrBMPb closely resembled those of vertebrate BMP-2 and BMP-4 and of Drosophila Decapentaplegic (DPP). In addition to the sequence similarity, HrBMPb overexpression induced the ventralization of Xenopus embryos, suggesting functional conservation. The zygotic expression of HrBMPb was first detected around gastrulation. HrBMPb expression was maintained in some cells at the lateral edges of the neural plate through gastrulation to neurulation, although that in the presumptive muscle cells was downregulated. HrBMPb was not expressed in the presumptive epidermis during gastrulation. When HrBMPb mRNA was injected into fertilized Halocynthia eggs, cells that normally give rise to the neural tissue differentiated into epidermis, causing a loss of anterior neural tissue in the larva. In addition, HrBMPb might function synergistically with HrBMPa, an ascidian homologue of BMPs-5 to 8. However, HrBMPb overexpression did not affect differentiation of the notochord and muscle cells. These results suggest that HrBMPb functions as a neural inhibitor and as an epidermal inducer but not as a ventralizing agent in ascidian development.