Neutropenia and survival outcomes in metastatic colorectal cancer patients treated with trifluridine/tipiracil in the RECOURSE and J003 trials.

BACKGROUND: The phase II J003 (N = 169) and phase III RECOURSE (N = 800) trials demonstrated a significant improvement in survival with trifluridine (FTD)/tipiracil (TPI) versus placebo in patients with refractory metastatic colorectal cancer. This post hoc analysis investigated pharmacokinetic data of FTD/TPI exposure and pharmacodynamic markers, such as chemotherapy-induced neutropenia (CIN) and clinical outcomes. PATIENTS AND METHODS: A total of 210 patients from RECOURSE were enrolled in this substudy. A limited sampling approach was used, with three pharmacokinetic samples drawn on day 12 of cycle 1. Patients were categorized as being above or below the median area under the plasma concentration-time curve (AUC) for FTD and TPI. We conducted a post hoc analysis using the entire RECOURSE population to determine the correlations between CIN and clinical outcome. We then carried out a similar analysis on the J003 trial to validate the results. RESULTS: In the RECOURSE subset, patients in the high FTD AUC group had a significantly increased CIN risk. Analyses of the entire population demonstrated that FTD/TPI-treated patients with CIN of any grade in cycles 1 and 2 had significantly longer median overall survival (OS) and progression-free survival (PFS) than patients who did not develop CIN and patients in the placebo group. Patients who required an FTD/TPI treatment delay had increased OS and PFS versus those in the placebo group and those who did not develop CIN. Similar results were obtained in the J003 cohort. CONCLUSIONS: In RECOURSE, patients with higher FTD drug exposure had an increased CIN risk. FTD/TPI-treated patients who developed CIN had improved OS and PFS versus those in the placebo group and those who did not develop CIN. Similar findings were reported in the J003 cohort, thus validating the RECOURSE results. The occurrence of CIN may be a useful predictor of treatment outcomes for FTD/TPI-treated patients. CLINICALTRIALS. GOV IDENTIFIER: NCT01607957 (RECOURSE). JAPAN PHARMACEUTICAL INFORMATION CENTER NUMBER: JapicCTI-090880 (J003).

A dose-finding approach for genomic patterns in phase I trials.

Precision medicine is an emerging approach for disease treatment and prevention that accounts for individual variability in genes, environment, and lifestyle. Cancer is a genomic disease; therefore, the dose-efficacy and dose-toxicity relationships for molecularly targeted agents in cancer most likely differ, based on the genomic mutation pattern. The individualized optimal dose - the maximal efficacious dose with a clinically acceptable safety profile - may vary depending on the genomic mutation patterns and should be determined prior to the use of these agents in precision medicine. In addition, genes that influence the individualized optimal doses should be identified in early-phase development. In this study, we propose a novel dose-finding approach to identify the individualized optimal dose for molecularly targeted agents in phase I cancer trials. Individualized optimal dose determination and gene selection were conducted simultaneously based on L1 and L2 penalized regression. Similar to most reported dose-finding approaches, this study considers non-monotonic patterns for dose-efficacy and dose-toxicity relationships, as well as correlations between efficacy and toxicity outcomes based on multinomial distribution. Our dose-finding algorithm is based on the predictive probability calculated with an estimated penalized regression model. We compare the operating characteristics between the proposed and existing methods by simulation studies under various scenarios.

Randomised phase II trial of irinotecan plus S-1 in patients with gemcitabine-refractory pancreatic cancer.

BACKGROUND: We aimed to compare the efficacy and safety of irinotecan/S-1 (IRIS) therapy with S-1 monotherapy in patients with gemcitabine-refractory pancreatic cancer. METHODS: Patients were treated with oral S-1 (80-120 mg for 14 days every 4 weeks) plus intravenous irinotecan (100 mg m-2 on days 1 and 15 every 4 weeks; IRIS group) or oral S-1 group (80-120 mg daily for 28 days every 6 weeks). The primary endpoint was progression-free survival (PFS). RESULTS: Of 137 patients enrolled, 127 were eligible for efficacy. The median PFS in the IRIS group and S-1 monotherapy group were 3.5 and 1.9 months, respectively (hazard ratio (HR)=0.77; 95% confidence interval (CI), 0.53-1.11; P=0.18), while the median overall survival (OS) were 6.8 and 5.8 months, respectively (HR=0.75; 95% CI, 0.51-1.09; P=0.13). Response rate was significantly higher in the IRIS group than in the S-1 monotherapy group (18.3% vs 6.0%, P=0.03). Grade 3 or higher neutropenia and anorexia occurred more frequently in the IRIS group. CONCLUSIONS: There was a trend for better PFS and OS in the IRIS group that could be a treatment arm in the clinical trials for gemcitabine-refractory pancreatic cancer.

A randomized phase III trial comparing S-1 versus UFT as adjuvant chemotherapy for stage II/III rectal cancer (JFMC35-C1: ACTS-RC).

BACKGROUNDS: Preventing distant recurrence and achieving local control are important challenges in rectal cancer treatment, and use of adjuvant chemotherapy has been studied. However, no phase III study comparing adjuvant chemotherapy regimens for rectal cancer has demonstrated superiority of a specific regimen. We therefore conducted a phase III study to evaluate the superiority of S-1 to tegafur-uracil (UFT), a standard adjuvant chemotherapy regimen for curatively resected stage II/III rectal cancer in Japan, in the adjuvant setting for rectal cancer. PATIENTS AND METHODS: The ACTS-RC trial was an open-label, randomized, phase III superiority trial conducted at 222 sites in Japan. Patients aged 20-80 with stage II/III rectal cancer undergoing curative surgery without preoperative therapy were randomly assigned to receive UFT (500-600 mg/day on days 1-5, followed by 2 days rest) or S-1 (80-120 mg/day on days 1-28, followed by 14 days rest) for 1 year. The primary end point was relapse-free survival (RFS), and the secondary end points were overall survival and adverse events. RESULTS: In total, 961 patients were enrolled from April 2006 to March 2009. The primary analysis was conducted in 480 assigned to receive UFT and 479 assigned to receive S-1. Five-year RFS was 61.7% [95% confidence interval (CI) 57.1% to 65.9%] for UFT and 66.4% (95% CI 61.9% to 70.5%) for S-1 [P = 0.0165, hazard ratio (HR): 0.77, 95% CI 0.63-0.96]. Five-year survival was 80.2% (95% CI 76.3% to 83.5%) for UFT and 82.0% (95% CI 78.3% to 85.2%) for S-1. The main grade 3 or higher adverse events were increased alanine aminotransferase and diarrhea (each 2.3%) in the UFT arm and anorexia, diarrhea (each 2.6%), and fatigue (2.1%) in the S-1 arm. CONCLUSION: One-year S-1 treatment is superior to UFT with respect to RFS and has therefore become a standard adjuvant chemotherapy regimen for stage II/III rectal cancer following curative resection.

Improvement of androgenetic alopecia with topical Sophora flavescens Aiton extract, and identification of the two active compounds in the extract that stimulate proliferation of human hair keratinocytes.

BACKGROUND: Androgenetic alopecia (AGA) is a hair loss disorder that commonly affects middle-aged men. To date, the properties of a number of natural or synthetic substances have been investigated for their ability to improve the condition. AIM: To evaluate the hair growth-promoting activities of an extract from the root of Sophora flavescens Aiton. METHODS: We used a human hair keratinocyte proliferation assay and ex vivo organ cultures of human hair follicle to examine the potential of the extract to stimulate hair growth via anagen elongation. We isolated the compounds promoting the growth of epithelial cells, and determined their chemical structures. A randomized, double-blinded, placebo-controlled clinical study for S. flavescens extract was carried out for 6 months with patients with AGA. RESULTS: The extract stimulated the proliferation of hair keratinocytes at a concentration of 0.1 ng/mL, while 100 ng/mL of the extract had a marked effect on hair shaft elongation in an organ culture of human hair follicle. Cell proliferation assay-directed fractionation led to the identification of two pterocarpan derivatives, L-maackiain and medicarpin, as active compounds that promote the proliferation of human hair keratinocytes. Studies in human subjects showed that improvement in the inspected alopecia scores in the lotion plus extract group were significant over a period of 6 months (P < 0.01). CONCLUSIONS: S. flavescens root extract is effective for the treatment of AGA. The isolated two pterocarpans might have important role in this effect.

Randomised phase II trial of S-1 plus oxaliplatin vs S-1 in patients with gemcitabine-refractory pancreatic cancer.

BACKGROUND: This randomised, open-label, multicenter phase II study compared progression-free survival (PFS) of S-1 plus oxaliplatin (SOX) with that of S-1 alone in patients with gemcitabine-refractory pancreatic cancer. METHODS: Patients with confirmed progressive disease following the first-line treatment with a gemcitabine-based regimen were randomised to receive either S-1 (80/100/120 mg day(-1) based on body surface area (BSA), orally, days 1-28, every 6 weeks) or SOX (S-1 80/100/120 mg day(-1) based on BSA, orally, days 1-14, plus oxaliplatin 100 mg m(-2), intravenously, day 1, every 3 weeks). The primary end point was PFS. RESULTS: Between January 2009 and July 2010, 271 patients were randomly allocated to either S-1 (n=135) or SOX (n=136). Median PFS for S-1 and SOX were 2.8 and 3.0 months, respectively (hazard ratio (HR)=0.84; 95% confidence interval (CI), 0.65-1.08; stratified log-rank test P=0.18). Median overall survival (OS) was 6.9 vs 7.4 months (HR=1.03; 95% CI, 0.79-1.34; stratified log-rank test P=0.82). The response rate (RR) was 11.5% vs 20.9% (P=0.04). The major grade 3/4 toxicities (S-1 and SOX) were neutropenia (11.4% and 8.1%), thrombocytopenia (4.5% and 10.3%) and anorexia (12.9% and 14.7%). CONCLUSIONS: Although SOX showed an advantage in RR, it provided no significant improvement in PFS or OS compared with S-1 alone.

Randomized phase III trial of treatment duration for oral uracil and tegafur plus leucovorin as adjuvant chemotherapy for patients with stage IIB/III colon cancer: final results of JFMC33-0502.

BACKGROUND: While adjuvant chemotherapy is preferable for high-risk colon cancer, treatment duration is controversial. Oral uracil and tegafur (UFT)/leucovorin (LV) is widely used as a standard adjuvant chemotherapy for colon cancer in Japan. We conducted a phase III trial to investigate the optimal duration of adjuvant chemotherapy for stage IIB/III colon cancer. PATIENTS AND METHODS: Patients with curatively resected stage IIB/III colon cancer were eligible for enrollment in this trial. Patients were registered within 6 weeks after surgery and were randomly assigned to receive UFT/LV for 28 of 35 days for 6 months in the control group or for 5 consecutive days per week for 18 months in the study group. The primary end point was the disease-free survival (DFS), and the secondary end points were overall survival (OS) and safety. RESULT: A total of 1071 patients were registered from 233 centers. A statistically significant difference in DFS was not observed between the study group and the control group; the 5-year DFS was 69% in the study group and 69% in the control group. The 5-year OS was 85% in the study group and 85% in the control group. CONCLUSION: Eighteen-month treatment with UFT/LV did not improve DFS or OS compared with 6-month UFT/LV treatment in patients with stage IIB/III colon cancer. The important finding from this study is that not 18 months but 6 months of treatment is enough for postoperative UFT/LV for stage IIB/III colon cancer. CLINICAL TRIAL NUMBER: UMIN-CTR C000000245.

Phase III study comparing oxaliplatin plus S-1 with cisplatin plus S-1 in chemotherapy-naïve patients with advanced gastric cancer.

BACKGROUND: We evaluated the efficacy and safety of S-1 plus oxaliplatin (SOX) as an alternative to cisplatin plus S-1 (CS) in first-line chemotherapy for advanced gastric cancer (AGC). PATIENTS AND METHODS: In this randomized, open-label, multicenter phase III study, patients were randomly assigned to receive SOX (80-120 mg/day S-1 for 2 weeks with 100 mg/m(2) oxaliplatin on day 1, every 3 weeks) or CS (S-1 for 3 weeks with 60 mg/m(2) cisplatin on day 8, every 5 weeks). The primary end points were noninferiority in progression-free survival (PFS) and relative efficacy in overall survival (OS) for SOX using adjusted hazard ratios (HRs) with stratification factors; performance status and unresectable or recurrent (+adjuvant chemotherapy) disease. RESULTS: Overall, 685 patients were randomized from January 2010 to October 2011. In per-protocol population, SOX (n = 318) was noninferior to CS (n = 324) in PFS [median, 5.5 versus 5.4 months; HR 1.004, 95% confidence interval (CI) 0.840-1.199; predefined noninferiority margin 1.30]. The median OS for SOX and CS were 14.1 and 13.1 months, respectively (HR 0.958 with 95% CI 0.803-1.142). In the intention-to-treat population (SOX, n = 339; CS, n = 337), the HRs in PFS and OS were 0.979 (95% CI 0.821-1.167) and 0.934 (95% CI 0.786-1.108), respectively. The most common ≥grade 3 adverse events (SOX versus CS) were neutropenia (19.5% versus 41.8%), anemia (15.1% versus 32.5%), hyponatremia (4.4% versus 13.4%), febrile neutropenia (0.9% versus 6.9%), and sensory neuropathy (4.7% versus 0%). CONCLUSION: SOX is as effective as CS for AGC with favorable safety profile, therefore SOX can replace CS. CLINICAL TRIAL NUMBER: JapicCTI-101021.

Long-term effects of the oral adsorbent, AST-120, in patients with chronic renal failure.

The oral adsorbent AST-120 has been widely used in Japan to delay the initiation of dialysis therapy in patients with chronic renal failure. This study evaluated the long-term effects of AST-120 in patients with chronic renal failure who had not previously undergone dialysis. One hundred out-patients were prospectively enrolled and prescribed 6 g/day oral AST-120 for >or= 1 year. The clinical effectiveness of AST-120 was evaluated by comparing changes in the slope of the reciprocal serum creatinine-time plot (1/sCr slope) before and after AST-120 administration. The 1/sCr slope improved significantly after >or= 1 year of AST-120 treatment and greatest improvement was observed in patients with the longest AST-120 administration period (> 30 months). The results suggest that long-term treatment with AST-120 may be beneficial for chronic renal failure patients in the pre-dialysis stage.

Improvement of peritoneal calcification after parathyroidectomy in a peritoneal dialysis patient.

Peritoneal calcification is one of the complications of peritoneal dialysis (PD). It can become serious, leading to severe abdominal pain and even death. Possible mediators of peritoneal calcification in PD patients are assumed to include acetate buffer, overdosage of vitamin D, repeated peritonitis, hypertonic dialysate, calciphylaxis and secondary hyperparathyroidism (SHPT). However, the mechanism and treatment of peritoneal calcification are controversial. Few reports have appeared on improvement of peritoneal calcification after parathyroidectomy (PTX) for SHPT of long duration. We report herein the case of a 48-year-old man on dialysis for 17 years including PD for 14 years. In 1989, he was admitted to hospital because of end-stage renal disease (ESRD), and started treatment with PD. Abdominal computed tomography (CT) first showed peritoneal calcification in August 2002. Peritoneal calcification did not improve despite conventional treatment including discontinuation of PD, control of calcium phosphate product to less than 55 mg2/dl2, removal of the peritoneal catheter and empirical prednisolone (PSL) usage. The intact parathyroid hormone (i-PTH) level was increased over 1,000 pg/ml and extra-osseous calcification occurred. Total PTX was performed in November 2004. Postoperatively, the i-PTH level decreased immediately and calcium phosphate product was maintained in the reference range. Abdominal CT after PTX showed improvement of peritoneal calcification in September 2005. It appeared that PTX could be used to treat patients with persistent peritoneal calcification not responding to conventional treatment. It was postulated that SHPT might play a crucial role in accelerating peritoneal calcification in PD patients.

Efficacy, toxicity and cost analysis for non-platinum triplet (gemcitabine and vinorelbine, followed by docetaxel) vs. platinum-based chemotherapy in IIIB/IV non-small-cell lung cancer: single-institution experience.

A new non-platinum sequential triplet combination chemotherapy regimen, comprising gemcitabine (1000 mg/m(2)) and vinorelbine (25 mg/m(2)), followed by docetaxel (60 mg/m(2)), was compared in terms of efficacy, toxicity and cost with platinum-based chemotherapy regimens (comprising cisplatin plus one or more other anti-tumour drugs) for the treatment of advanced non-small-cell lung cancer in a matched, small-sample size, case-control study. Patients were selected from a single institution. Patients in the platinum and non-platinum groups were matched for clinical stage (IIIB/IV), performance status (0/1), age and sex. For the non-platinum and platinum groups, the overall response rates were 40% and 47%, and the median survival times were 14 and 14.5 months respectively. The most common grade 3-4 toxicity was neutropenia (27%) in the non-platinum group and nausea/vomiting (67%) in the platinum group. The total treatment cost did not differ significantly between the two groups. The non-platinum sequential triplet combination chemotherapy regimen studied was shown to be as effective as the traditional cisplatin-based combination chemotherapy regimen, and was associated with less toxicity.

An interpretation of the neonatal period definition obtained with echocardiographic examination by using change point regression analysis.

BACKGROUND: We had reported on the left ventricular end-diastolic dimension (LVDd) in normal children from the premature/neonatal period to the adolescence period by using two-dimensional echocardiography, and formulated equations to evaluate normal LVDd values by using body height as an index. There was an inflection point at around birth that seemed relevant to the fetal and neonatal periods for the relation of LVDd and body height. METHODS: We aimed to reveal the true inflection point and its meaning by using change point regression analysis. The study group consisted of 421 neonates and infants. The ages at examination ranged from 24 weeks' gestation to 1 year after birth. The subjects' body heights at examination were between 31 and 75 cm. RESULTS: The analysis showed no definite inflection point in height, and a flat bottom was observed between body heights of 48 and 55 cm. The inflection range seemed to mean the duration of the neonatal period, which connects the fetal and infantile periods. CONCLUSION: The results revealed that neonates reach the infantile period slower than usually imagined, and the end of the neonatal period may be at the age when the body height is around 55 cm- in other words, at 2 months after birth. This manuscript might be the first one to consider the definition of the neonatal period using cardiovascular methods.

Dose-response to a jelly preparation of calcium polystyrene sulfonate in patients with hyperkalemia--changes in serum potassium levels with or without a RAAS inhibitor.

AIMS: In this study, dose-response of the serum potassium-lowering effect of a calcium polystyrene sulfonate (PS) preparation was investigated. Changes in the serum potassium level were also examined with or without application of a RAAS inhibitor, which is said to increase the serum potassium level. SUBJECTS AND METHODS: 23 patients diagnosed to have hyperkalemia associated with chronic renal failure were enrolled in this study. The study drug, a PS-Ca jelly preparation (Argamate jelly), was started at a daily dose of 1 preparation (5 g as PS-Ca), and the dose was increased by 1 preparation every month to finally reach 3 preparations per day. Blood samples were collected once a month and serum levels of creatinine and electrolytes were measured. RESULTS: PS-Ca jelly decreased serum potassium levels in a dose-dependent manner. Decreases were 0.67 mEq/l at 5 g of PS-Ca/day, 1.06 mEq/l at 10 g/d, and 1.33 mEq/l at 15 g/d. Irrespective of the use of the RAAS inhibitor, serum potassium levels decreased significantly in a dose-dependent manner. Furthermore, no major change in serum creatinine levels occurred in subjects in which the RAAS inhibitor was used, although in subjects in which the RAAS inhibitor was not used, serum creatinine level tended to gradually increase. CONCLUSION: Serum potassium levels were reduced in a dose-dependent manner by administration of 5-15 g/d of PS-Ca, and it appeared that together with control of serum potassium levels, renal function should be maintained by continuous administration of RAAS inhibitor.

Effects of heparin on osteoclast activity.

The effect of heparin on osteoclastic bone resorption was studied in vitro using the disaggregated osteoclast resorption assay. Bone resorption was assessed by counting the resorption lacunae on bone slices by light microscopy. Low concentrations of heparin (5 micrograms/ml) increased bone resorption by isolated chick and rat osteoclasts. Among other glycosaminoglycans tested at 5 micrograms/ml, only dextran sulfate showed a small but significant stimulation of resorption. Chondroitin sulfates A, B, and C were without effect at 25 and 100 micrograms/ml, whereas resorption was increased by 100 micrograms/ml of heparan sulfate. With chick osteoclasts, which could be maintained in serum-free conditions, a stimulatory effect of heparin was found both in the presence of 5% fetal calf serum and in serum-free media containing insulin, transferrin, and selenium. The magnitude of the heparin-induced increase in resorption was similar in the presence or absence of serum. The stimulation of resorption was associated with an increase in the number of osteoclasts on bone slices. Pretreatment of the bone slices with heparin also enhanced resorption. In time course experiments, 5 micrograms/ml of heparin caused a doubling of chick osteoclast activity index (number of resorption pits per number of osteoclasts) at 12 and 24 h. In 24 h cultures, treatment with 10 micrograms/ml of the arginine-rich basic protein, protamine, 1 microgram/ml of the immunosuppressant, cyclosporine A, or 5 micrograms/ml of the cysteine-proteinase inhibitor, leupeptin, negated the heparin effect on bone resorption. Leupeptin also inhibited basal resorption.(ABSTRACT TRUNCATED AT 250 WORDS)

A Creutzfeldt-Jakob disease agent (Echigo-1 strain) recovered from brain tissue showing the 'panencephalopathic type' disease.

We used histologic evidence of degenerative changes in both the gray and white matter of the brain to diagnose a patient as having the panencephalopathic type of Creutzfeldt-Jakob disease (CJD). This type of CJD is relatively common in Japan, but not in North America or Europe. We recovered a transmissible pathogen (Echigo-1 strain) from an autopsy specimen of the patient's brain and passed it serially in Hartley guinea pigs. After a long latent period, it caused degenerative changes, mainly in the thalamic area of the guinea pig brain. On the 4th passage, a substrain emerged with a short latent period. When cross-transmitted to Golden Syrian hamsters, this substrain induced severe degeneration in both the thalamus and cerebral cortex. We compare our results with those for other experimental CJDs produced by other types of this disease.

Evidence for association between paraoxonase gene polymorphisms and atherosclerotic diseases.

Paraoxonase 1 (PON1) is proposed to have an anti-atherogenic action. Two polymorphisms at the PON1 (M/L55 and Q/R192) have been shown to be associated with coronary artery disease (CAD). This conclusion is not drawn universally, however, and specific ethnic characteristics may be important determinants in this association. Recently two homologues of PON1 - PON2 and PON3 - were identified and Sanghera et al. demonstrated C/S311 polymorphism at PON2 was associated with the risk of CAD. Within that context, we investigated the association between the aforementioned three polymorphisms and CAD and ischemic stroke in a Japanese population. The study population included 431 control subjects, 210 CAD patients, and 235 ischemic stroke patients. Genotype distributions and allele frequencies of M/L55 and C/S311 were similar among the control and patient groups, whereas the R192 allele frequency was significantly higher (P<0.001) in CAD (75%) and ischemic stroke (76%) patients than in control subjects (65%). When confounding influences of other risk factors were controlled for by multivariate analysis, R192 remained an independent risk determinant (additive model: OR (95% CI), P value CAD: 2.01 (1.45-2.79), 0.0001; ischemic stroke: 1.84 (1.34-2.52), 0.0002 (three genotypes into calculation)). Taken together, our data indicate that the Q/R192 is principally associated with both CAD and ischemic stroke in Japanese.

Frequency of clonally expanded T cells evaluated by PCR from a single cell.

In analyses of antigen-specific immune responses, it is essential to estimate the frequency of individual T cell clonotypes. This frequency has been estimated, however, only indirectly by the frequency of T cell receptor (TCR) mRNA. We have developed a method to determine T cell frequency directly by cell count using reverse transcription polymerase chain reaction (RT-PCR) amplification of TCR beta genes from single cell-derived cDNA (single cell PCR). In a study of clinical samples, the frequency of clonally expanded T cells estimated by TCR frequency analysis was found to be higher than that by single cell PCR. Single cell PCR can estimate T cell frequency accurately, as it is not affected by skewed PCR amplification or different TCR mRNA expressions in individual T cells.

Homocysteine as a risk factor for restenosis after coronary angioplasty.

We examined the relationship between plasma homocysteine levels and restenosis after PTCA (Percutaneous transluminal coronary angioplasty) to investigate whether plasma homocysteine levels can be a predictor of restenosis after PTCA. One hundred and twelve male patients who have undergone a successful elective PTCA were consecutively enrolled and plasma homocysteine levels were measured at the time of follow-up angiography. Plasma homocysteine levels in patients with restenosis were significantly higher than those in patients without restenosis (15.0 +/- 3.9 vs. 13 +/- 2.9 micromol/L; P = 0.011). The difference was augmented when diabetic patients were selectively studied. The comparison between restenosis group and non-restenosis group indicated the threshold effect of hyperhomocysteinemia. These results suggest that plasma homocysteine is a potential risk factor of restenosis after PTCA, and therapeutic strategy targeted against hyperhomocysteinemia may be beneficial for preventing restenosis.

Lack of association between the platelet glycoprotein Ia C807T gene polymorphism and myocardial infarction in Japanese. An approach entailing melting curve analysis with specific fluorescent hybridization probes.

The platelet-collagen receptor, glycoprotein Ia/IIa (integrin alpha2beta1) plays a fundamental role in the adhesion of platelets to fibrillar collagen, an event leading to platelet activation and thrombus formation and contributing to the pathogenesis of thrombotic disease. Further, glycoprotein Ia/IIa receptor density and function may be associated with two linked and silent polymorphisms (807C/T and 873G/A) within the glycoprotein Ia gene. We tested the extent to which these polymorphisms serve as genetic markers of myocardial infarction in a Japanese population. A case-control study was carried out using 210 Japanese myocardial infarction patients and 420 age- and sex-matched controls. Genotyping was accomplished using PCR followed by melting curve analysis with specific fluorescent hybridization probes. The 807CC, CT, TT genotypes linked perfectly to the 873GG, GA, AA genotypes, respectively. Allele frequencies of the 807T (873A) variant were similar in the control and patient groups (0.373 vs. 0.352). The 807T and 873A variants of platelet glycoprotein Ia gene are common and in a perfect linkage in the Japanese population, but it appears unlikely that the 807T (873A) variant represents a useful marker of increased risk for myocardial infarction.

Statistical characterization of negative control data in the Ames Salmonella/microsome test.

A statistical characterization of negative control data in the Ames Salmonella/microsome reverse mutation test was performed using data obtained at Takeda Analytical Research Laboratories during January 1989 to April 1990. The lot-to-lot variability of bacterial stock cultures and day-to-day variability of experiments were small for Salmonella typhimurium strains TA1535 and TA1537 and Escherichia coli WP2uvrA, but they were larger for S. typhimurium TA100. The number of revertant colonies for all test strains studied here followed Poisson distributions within the same day. The two-fold rule that is an empirical method to evaluate the Ames Salmonella/microsome test results has been widely used in Japan. This two-fold rule was evaluated statistically. The comparison-wise type I error rate was less than 0.05 for TA98, TA100, TA1535, TA1537, and WP2uvrA. Moreover, this rule is particularly conservative for TA100, for which the type I error rate was nearly 0.