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Biomedical subjects

C Hamada

Publications and source records attributed to C Hamada.

At least 19 recordsLinked to original sources

Evidence of Qi-gong energy and its biological effect on the enhancement of the phagocytic activity of human polymorphonuclear leukocytes.

In order to test for an effect of phosphate buffered saline (PBS) treated externally with Qi energy ("Qi-treated" PBS) on the phagocytic activity of human polymorphonuclear leukocytes (PMNs), rigorously controlled experiments employing masking and randomized procedures were carried out under independent monitoring. In all experiments, Qi treatment was externally applied under monitoring to newly purchased unopened 100 ml bottles of PBS, and the PMN phagocytic activity was assayed by one experimenter in masked, randomized and monitored conditions using a highly sensitive chemiluminescence method. Phagocytic activity data were obtained in triplicate for each sample and then statistically analyzed. The PBS samples Qi-treated by the Qi-gong master and by one of the Qi-gong trainees showed clear stimulation of PMN phagocytic activity which was significant statistically, and this phenomenon was highly reproducible. Out of 10 experiments by the Qi-gong master, only twice did Qi-treatment fail to influence the PBS. The activity of Qi-treated PBS decayed over days or weeks. Furthermore, it was found that Qi-treated PBS had decreased phagocytic stimulatory activity after microwave treatment, but not after autoclave treatment. We also demonstrated that microwave irradiation and infrared laser pulse irradiation have similar effects on PBS as Qi-treatment. The results obtained in this experiment provide evidence of the existence of Qi energy, its ability to influence an electrolyte solution and its biological effect. Furthermore, microwave or infrared laser pulse treatment was found to partly mimic the Qi-treatment of PBS.

Adolescent↗

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.

Adult↗

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.

Aged↗

[The role of biostatistics in pharmacological studies (randomization and statistical evaluation)].

Biostatistics has an important role in both designing a pharmaceutical experiment and evaluating its result. Randomization techniques are essentially important in designing an experiment. The goal of randomization is transforming systematic errors into random errors and confirming comparability among experimental groups. Randomization also provides a rationale for applying statistical tests. Combining randomization techniques with blinding and local control enables us to construct a scientifically reliable and effective experiment. An appropriate statistical analysis absolutely depends on the method of randomization. In order for a pharmacological study to be successful, it is very important to consider statistical aspects in the designing stage.

Biometry↗

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.

Aged↗

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.

Arthritis, Rheumatoid↗

New DNA polymorphisms of human MMH/OGG1 gene: prevalence of one polymorphism among lung-adenocarcinoma patients in Japanese.

MMH/OGG1 is an 8-hydroxyguanine-specific DNA glycosylase/AP-lyase, one of the mutator enzymes for the excision repair of 8-hydroxyguanine. DNA polymorphisms in human MMH/OGG1 gene were newly identified and analyzed to examine a possible association with lung-cancer risk by a population-based study. Polymorphic allele 3 in hMMH/OGG1 exon 1 was significantly prevalent among Japanese patients with adenocarcinoma of the lung [odds ratio (OR): 3.152, 95% confidence interval (CI): 1.266-7.845], indicating that the excision repair of 8-hydroxyguanine may play a role in predisposition to lung cancer.

Adenocarcinoma↗

Risk factors for the progression of treated primary open-angle glaucoma: a multivariate life-table analysis.

BACKGROUND: Several factors have been reported as risk factors for the progression of primary open-angle glaucoma (POAG) but previous reports were not necessarily in agreement. We applied a multivariate life-table analysis to a large number of longitudinal data to determine the extent of the influence of various factors simultaneously. METHODS: Two hundred fifteen eyes of 215 POAG patients were included. The follow-up period ranged from 24 to 134 months (average 82.7 months). The visual field stage was determined separately in upper and lower hemifields according to the classification of Aulhorn (modified by Greve). The progression was defined as an irreversible increase of the stage in at least one hemifield. The follow-up data were analyzed with the Cox proportional hazard model. RESULTS: Mean intraocular pressure (IOP) in the follow-up period and the initial visual field stage significantly affected POAG progression (P<0.05). The risk of POAG progression was calculated to double as the mean IOP increased by 4 mmHg. Eyes with the initial visual field of stage 0-1 and moderately advanced stages had a greater risk of progression than other stages. CONCLUSION: To prevent the progression of POAG, the IOP should be kept as low as possible, particularly at the early and moderately advanced stages.

Age Factors↗

Ultrasound biomicroscopy of ciliary body cysts.

PURPOSE: To report the incidence and sector distribution of ciliary body cysts in normal subjects and to assess association with age using ultrasound biomicroscopy. METHODS: We prospectively examined 232 eyes of 116 normal subjects (51 men and 65 women) ranging in age from 15 to 84 years (mean +/- SD, 45.2 +/- 20.1). Complete ophthalmic examination, including gonioscopy and ophthalmoscopy with mydriasis, was performed. In addition, the circumference of the ciliary body was divided into eight sectors, and scanned in transverse and radial sections by high-resolution ultrasound biomicroscope to determine the incidence, distribution, and location of cysts. RESULTS: Based on one randomly chosen eye from each subject, cysts were detected in 63 (54.3%) of the 116 subjects. Cysts were found most frequently and in greater numbers in the inferior and temporal sectors. The incidence and the distribution range, expressed as the number of involved sectors per eye, were 73.1% and 3.8, respectively, for subjects 20 approximately 29 years old; both incidence and the number of involved sectors decreased with age (P = .0001). Cyst diameter ranged from 200 to 2500 microm; mean size decreased with age (P = .001). Gender and refractive error did not affect the incidence and distribution. There was significant bilateral correlation in the number, incidence, and distribution of ciliary body cysts. CONCLUSION: Ultrasound biomicroscopy disclosed a high incidence of ciliary body cysts in normal subjects, which decreased with age. Cysts were multiple and bilateral in many subjects.

Adolescent↗

Adjuvant therapy with oral fluoropyrimidines as main chemotherapeutic agents after curative resection for colorectal cancer: individual patient data meta-analysis of randomized trials.

BACKGROUND: Oral 5-fluorouracil and its prodrugs (tegafur, carmofur) is now being studied for adjuvant chemotherapy of curatively resected colorectal cancers. To evaluate the effect of these oral fluoropyrimidines (o-FPs), an individual patient data (IPD) meta-analysis of randomized clinical trials was performed in Japan as an inter-trialist group study. METHODS: Data from the three clinical trials in which postoperative adjuvant therapy with o-FPs was compared with surgery alone in patients with colorectal cancer were sought. IPD from a total of 4960 patients with follow-up periods of at least 5 years were analyzed. RESULTS: The results of the meta-analysis on an 'intention to treat' basis demonstrated a significant benefit of o-FPs in terms of the disease-free survival (DFS) of the total patients [risk ratio (RR) 0.830, 95% confidence interval (CI) 0.742-0.929, P = 0.001]. o-FPs were also demonstrated to be effective for survival in rectal cancer (RR 0.857, 95% CI 0.734-0.999, P = 0.049) and in Dukes'C colorectal cancer (RR 0.828, 95% CI 0.711-0.965, P = 0.016). CONCLUSION: The results suggest the advantage of long term o-FPs, possibly with the injection of mitomycin C, for prognosis for curatively resected colorectal cancer patients.

Administration, Oral↗

Comparison of T-cell receptor Jbeta gene usage in spleen cells of different mouse strains.

To elucidate whether T-cell receptor Jbeta gene usage was affected by major histocompatibility complex haplotypes and other genetic backgrounds, we investigated such usage with Jbeta-specific probes in four different mouse strains. As a result, (a) frequent usage of Jbeta2.1 and Jbeta2.6, (b) infrequent usage of Jbeta1.3, Jbeta1.5 and Jbeta1.6, and (c) predominant usage of the Jbeta2 cluster compared to the Jbeta1 cluster were found. Importantly, these biases were common to almost all the tested Vbeta families of the four strains. Thus, TCR Jbeta usage would be independent of the major histocompatibility complex haplotypes and other genetic backgrounds.

Animals↗

Histopathological prognostic factors influencing long-term prognosis after surgical resection for hepatic metastases from colorectal cancer.

OBJECTIVE: We aimed to present new histopathological features of metastatic liver nodules as more reliable prognostic factors after surgical resection for colorectal metastatic cancer. METHODS: Clinicopathological features, including newly proposed histopathological ones, of 63 consecutive patients were reviewed retrospectively to determine which most strongly correlated with long-term prognosis after hepatectomy for metastatic tumors from colorectal cancers, using univariate and multivariate analysis. RESULTS: The 1-, 3-, and 5-year cancer-related survival rates after hepatectomy were 87.8%, 55.2%, and 47.3%, respectively. New histopathological features we proposed, which are expansive growth, marginal fibrosis, and peritumorous lymphocytic infiltration of hepatic tumor, were significant prognostic factors for cancer-related survival after hepatectomy in an univariate analysis. Also in a multivariate analysis, i.e., a stepwise Cox regression analysis, infiltrative, i.e., not expansive, growth of hepatic tumor was one of significant and independent poor prognostic factors for survival after hepatectomy, with moderate to severe lymphatic vessel involvement of the primary colorectal lesion, microscopic cancer invasion at the surgical margin of hepatectomy, and extrahepatic distant metastases. CONCLUSIONS: Our results suggest that our proposed new histopathological features of hepatic metastases were good predictors of prognosis after surgical resection for hepatic metastases from colorectal cancer. Especially, infiltrative growth of hepatic tumor is strongly correlated with a poor prognosis after hepatectomy.

Colorectal Neoplasms↗

Polymorphism of the methionine synthase gene : association with homocysteine metabolism and late-onset vascular diseases in the Japanese population.

Methionine synthase and 5,10-methylenetetrahydrofolate reductase (MTHFR) sequentially catalyze the remethylation of homocysteine to methionine. A point mutation in the encoding region of the methionine synthase gene, which results in substitution of an aspartic acid for a glycine residue (D919G), has been identified in patients of the cblG genetic complementation group; these patients exhibit significantly decreased methionine synthase activity. Nevertheless, the D919G mutation has also been reported to be common in the general population. In this study, we analyzed the distribution of methionine synthase D/G polymorphism in the Japanese population and examined the extent to which it is associated with altered homocysteine metabolism and late-onset vascular diseases. We studied 215 patients with coronary artery disease, 251 patients with histories of ischemic stroke, and 257 control subjects. The methionine synthase genotype was analyzed by polymerase chain reaction followed by HaeIII digestion; allele frequencies for the D919G variant of the enzyme proved to be similar in all 3 subject groups (control subjects, 0.17; coronary artery disease patients, 0. 17; and ischemic stroke patients, 0.19). Furthermore, in patients with ischemic stroke, plasma levels of homocyst(e)ine and folate were similar, irrespective of methionine synthase genotype. Thus, the methionine synthase D919G mutation was found to be common in the Japanese general population, and it appears unlikely that this polymorphism has a major effect on homocysteine metabolism and/or the onset of vascular diseases.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

Anastomotic aneurysms after surgical treatment of Takayasu's arteritis: a 40-year experience.

PURPOSE: To evaluate the clinical characteristics of anastomotic aneurysms that develop in surgically treated patients with Takayasu's arteritis. METHODS: Among 103 patients with Takayasu's arteritis treated surgically over 40 years, 91 patients with 259 anastomoses (allowing for exclusion of 12 operative deaths) participated in follow-up study from 1 month to 37.3 years with a mean value +/- SEM of 17.3 +/- 1.1 years with a follow-up completion rate of 93% at 30 years. The clinical characteristics of anastomotic aneurysms were clarified, and the influences of several factors (sites of anastomoses, occlusive or aneurysmal disease, suture material, preoperative systemic inflammation, and administration of corticosteroids) on formation of anastomotic aneurysms were analyzed by means of life-table method and Cox regression analysis. RESULTS: Twenty-two uninfected anastomotic aneurysms were found among 14 patients (22 of 259 anastomoses, 8.5%). The interval between the previous operation and diagnosis varied from 1.6 to 30 years with a mean value +/- SEM of 9.8 +/- 1.8 years. The cumulative incidence of anastomotic aneurysm at 20 years was 12.0%. Systemic inflammation or steroid administration had little influence on formation of anastomotic aneurysm. Instead, anastomotic aneurysm tended to occur after operations for aneurysmal lesions. CONCLUSIONS: Anastomotic aneurysm can occur anytime after operations for Takayasu's arteritis. The development of anastomotic aneurysm is not influenced by any factor specific to this disease except the presence of an aneurysmal lesion.

Adolescent↗