Calculation of personal dose equivalent for positron-emitting radionuclides using Monte Carlo code EGS5.

The conversion coefficients, H'(d,α)/Φ, for monoenergetic positrons and positron-emitting radionuclides were calculated by using the user code UCICRPM of the Monte Carlo code EGS5 to estimate the radiation dose for medical staff involved in positron emission tomography examinations. From these coefficients, the dose equivalent rates per unit activity at 0.07 and 10 mm depths in a soft tissue for a straight-line source of 2-deoxy-2-[(18)F]fluoro-d-glucose ((18)F-FDG) were calculated by using the developed user code UCF18DOSE. The dose equivalent rates per unit activity at 0.07 and 10 mm depths were measured by using a personal dosemeter (DOSE(3)) under the same conditions as those considered in the calculation. The calculated dose equivalent rates per unit activity at 0.07 and 10 mm depths were 0.116 and 0.0352 pSv min(-1) Bq(-1), respectively, at 20 cm from the (18)F-FDG injection tube.

Association of HLA Class II alleles and haplotypes with cervical dystonia: HLA DR13-DQ6 (DQB1*0604) homozygotes are at greatly increased risk of cervical dystonia in Caucasian Americans.

An unanticipated discovery was made while examining genetics of the immune response in patients treated with botulinum neurotoxin (BoNT), which included cervical dystonia (CD) patients. Initial examination of HLA DQA1:DQB1 frequencies revealed an unexpectedly high number of DQA1*0102:DQB1*0604 homozygotes (hz) in the CD patients. We typed the BoNT-treated CD Caucasian subset for HLA-DRB1, DQA1, and DQB1 and succeeded in typing HLA-DRB1, -DQA1, and -DQB1 for 75 of the patients. Two statistical methods found the DQB1 locus associated with CD and one method found a probable association of DQB1*0604. Examination of the allele and haplotype pairing indicated that DQB1*0604 hz comprised most to all of the positive association. Other than this genotype, one other allele, DQB1*0504 contributes to the association of the DQB1 locus. These findings indicate a probable infectious and/or autoimmune component in some CD patients. However, longer distance associations within an extended and conserved DQB1*0604 bearing haplotype leave a possibility that a locus proximal to DQB1 might be involved.

A prospective randomized trial of either famotidine or omeprazole for the prevention of bleeding after endoscopic mucosal resection and the healing of endoscopic mucosal resection-induced ulceration.

BACKGROUND: It has been reported that inhibitors of gastric acid secretion prevent bleeding after endoscopic mucosal resection for mucosal gastric neoplasm. However, uncertain whether an histamine2-receptor antagonist or proton-pump inhibitor is more effective. AIM: To evaluate prospectively the effectiveness of famotidine or omeprazole for ulcer management after endoscopic mucosal resection. METHODS: From July 2003 to October 2004, 57 patients were randomly assigned to famotidine or omeprazole for the management of endoscopic mucosal resection. Both drugs were given intravenously for the first 2 days, thereafter by mouth. The bleeding rates after endoscopic mucosal resection, the effects on the healing of endoscopic mucosal resection-induced ulceration, and cost-benefits were compared. RESULTS: Twenty-eight patients received famotidine and 29 received omeprazole. No significant difference was observed between the two groups in patient characteristics. The bleeding rates after endoscopic mucosal resection were not significantly different (18% vs. 14%) between the groups. Similarly, no differences were seen in the size of the endoscopic mucosal resection-induced ulceration at 1, 30 and 60 days after resection between groups. The total costs of anti-secretory agents demonstrated a significant cost-benefit to those treated with famotidine (10,420 yen vs. 17,782 yen). CONCLUSIONS: Famotidine is suggested as a better alternative to omeprazole for the management of endoscopic mucosal resection, as it showed a clear cost-benefit, and the healing results after endoscopic mucosal resection were similar for the two treatment strategies.

Evaluation of cutoff levels for screening of gastric cancer using serum pepsinogens and distributions of levels of serum pepsinogen I, II and of PG I/PG II ratios in a gastric cancer case-control study.

This study was carried out to determine the cutoff levels of serum pepsinogen (PG) I, II and their ratio of PG I/PG II for gastric cancer to establish a better screening system. Optimal cutoff levels for gastric cancer screening using serum pepsinogens were determined using Youden's index. The sensitivity, specificity and Youden's index for gastric cancer cases were calculated according to sex, age and the stage of gastric cancer, and the maximum Youden's index in each category was adopted as the cutoff level for gastric cancer screening using serum pepsinogens. The maximal Youden's index in all gastric cancer cases was 0.37, corresponding to a cutoff level of PG I < 40 (micrograms g/l) and PG I/PG II < 3.5. The sensitivity and specificity for gastric cancer cases of these cutoff levels were 0.50 and 0.87, respectively. In future, better criteria for gastric cancer screening have to be examined with the estimation of Youden's index in addition to other epidemiological methods such as ROC (receiver operating characteristic) curves and/or cost benefit analyses.

Assessment of insulin resistance in acromegaly associated with diabetes mellitus before and after transsphenoidal adenomectomy.

With a euglycemic hyperinsulinemic clamp method, whole-body insulin resistance was assessed in 6 cases with acromegaly associated with diabetes mellitus before and after transsphenoidal adenomectomy. The glucose infusion rate (GIR) correlated well with the plasma IGF-I level but poorly with that of GH. Further improvement in insulin sensitivity occurred 3-4 months after operation without substantial changes in plasma levels of both GH and IGF-I or glycemic control. These results indicate that GH excess can induce insulin resistance in association with plasma IGF-I and also through undefined secondary effect.

Transvaginal ultrasonographic cervical assessment for the prediction of preterm delivery.

To determine the usefulness of transvaginal ultrasonographic cervical assessment for the prediction of preterm delivery in an apparently normal population, 729 pregnant women (between 15 and 34 weeks' gestation) were randomly enrolled in the study in ten tertiary perinatal centers in Japan. Cervical parameters, including cervical length, internal os dilatation, and funneling depth, were measured by transvaginal ultrasound. The predictive values of these measurements for preterm delivery were investigated in a prospective fashion. Among various cervical parameters, cervical length showed the best correlation with pregnancy outcome. Cervical length (mm) was gradually decreased as the gestational age progressed, the regression line being y = 41.21-0.22x. When the mean cervical length minus 1 standard deviation at each gestational age was chosen as a cut-off value, the group with a shortened cervix showed a significantly high preterm delivery rate exclusively in the primigravidae (odds ratio: 4.86, 95% CI: 1.85-12.72). Internal os dilatation, in contrast, was a useful predictor in multiparous women (odds ratio: 6.00, 95% CI: 1.65-21.71). It was concluded that tranvaginal ultrasonographic cervical assessment, especially the measurement of cervical length, was effective for the prediction of preterm delivery in the primigravidae.

[Progression of senile aortic valve calcification: echocardiographic and clinical assessment].

Factors involved in the progression of senile aortic valve calcification were evaluated by analyzing the clinical and echocardiographic characteristics of patients older than 69 years with senile aortic valve calcification. The patients were divided into three groups; group 1: 46 male and 40 female patients with calcification of one cusp and almost normal pliability of three cusps, group 2: 48 males and 55 female patients with calcification of two or three cusps, mildly reduced pliability of calcified cusps, and aortic valve area (AVA) > or = 2.0 cm2, group 3: 26 male and 31 female patients with calcification of two or three cusps, significantly reduced pliability of calcified cusps, and AVA < or = 1.5 cm2. There were no significant differences in age, weight, height, left ventricular dimension, or left ventricular wall thickness between these three groups. For male patients, the end-diastolic maximum left ventricular outflow tract dimensions (LVOT) in groups 1, 2, and 3 were 20 +/- 2 mm, 19 +/- 2 mm (p < 0.01 vs group 1), and 17 +/- 3 mm (p < 0.001 vs group 1, p < 0.01 vs group 2), respectively. For female patients, the LVOTs of groups 1, 2, and 3 were 18 +/- 2 mm, 16 +/- 2 mm (p < 0.001 vs group 1), and 16 +/- 2 mm (p < 0.001 vs group 1), respectively. Reduction in LVOT was not associated with left ventricular hypertrophy or decrease in dimension of aortic annulus. In female patients, the frequency of mitral annular calcification of group 3 was 61% [p < 0.05 vs group 1 (35%), p < 0.01 vs group 2 (25%)].(ABSTRACT TRUNCATED AT 250 WORDS)

[Evaluation of methods for measuring daily physical activity in terms of energy expenditure].

Various methods exist for measuring daily physical activity and daily energy expenditure and daily pedometer readings are most commonly used for the amount of physical activity. In this study, three methods for measuring energy expenditure-24-hr heart rate method (HR), time study method, and caloric expenditure accumulator (CC)-, and the feasibility of a pedometer for the assessment of energy expenditure were examined under laboratory conditions and during normal daily life. Daily physical activity was measured by four methods (HR, Time study, CC, Pedometer) in a field study of 14 young, healthy and sedentary women, and compared. Laboratory validation of the three methods with measurement of oxygen uptake was performed with 5 young men and 1 woman walking and running at different speeds and grades on a treadmill. In addition validation tests of whether pedometer readings reflect differences in energy expenditure due to speed and grade and whether pedometer counts steps exactly were also conducted. The 24-hr energy expenditure derived from CC was significantly lower than that derived from HR and Time study, due to lower estimation of energy expenditure from activities compared to other methods. In the laboratory study, the energy expenditure measured at 5% grade was low by CC and differences in energy expenditure for changes in grade could not be differentiated. Time study revealed a significant relationship between CC and HR in field study. These results suggest that CC tends to underestimate the 24-hr energy expenditure from activity.(ABSTRACT TRUNCATED AT 250 WORDS)

[Studies on evaluation of risk factors of cancer by a large-scale cohort study newly organized in Japan--planning and pilot study].

A large-scale cohort study has been planned in cooperation of 22 epidemiologists in Japan since 1986. The objective of this new cohort aged more than 40, consisting the inhabitants throughout Japan is to evaluate risk factors of cancer already known and suspected agents in so rapidly changing society of Japan where age-sex contraction of population, disease pattern and lifestyle habits have remarkably changing for the last decades. The factors examined are not only social factors but also biological ones from blood, serum and other body fluids. At the same time serum bank of healthy inhabitants in Japan is established in this study.

[Methodological consideration on evaluation of lung cancer screening program: one-step process and two-step process].

A reasonable method to evaluate lung cancer screening program is to measure the reduction in death rate from lung cancer among those randomly allocated to screening program (one-step process). Alternative method is two-step process; step 1 is to measure what proportion of lung cancer patients, can be detected through screening and how early the screening can detected lung cancer patients, and step 2 is to delineate effectiveness of therapy following early detection. Advantages and disadvantages of the two processes were described in view of statistical power and sample size. In addition, a workplace-based screening program using chest X-ray files was mentioned as an example of step 1 of two-step process. The example also included economical consideration of the screening.

Estimating evolutionary distance from restriction maps of mitochondrial DNA with arbitrary G+C content.

We develop a mathematical model for estimating evolutionary distance from restriction enzyme maps, which incorporate non-uniformity of the rate of base substitution into the theory and allows for an arbitrary G+C content at equilibrium. When the G+C content differs significantly from 1/2, the traditional model of base changes can introduce a systematic bias which depends upon the base composition of the restriction site. In addition, the accuracy of estimated evolutionary distance depends heavily upon the choice of restriction enzyme in that the expected number of sites is also affected. Monte Carlo experiments are conducted to check the validity of the present theoretical treatment and from which we draw several cautionary notes on estimation. An application is made to the available data on restriction enzyme maps of human mitochondrial DNA where the G+C content is approximately 1/3.

A criterion for the establishment of a stable polymorphism of higher order with an application to the evolution of polymorphism.

This note gives some further useful properties of the constant fitness selection model for multiple alleles which pertain to the effects of adding a new allele to n preexisting alleles in stable equilibrium. In particular the conditions are derived for the establishment of a stable equilibrium involving all n + 1 alleles. For 3 alleles (i.e. n = 2) I give a complete qualitative solution, including the case of the replacement of one diallelic polymorphism by another. As an application I discuss a possible mechanism for the evolution of polymorphism using Monte Carlo methods similar to Lewontin, Ginzburg and Tuljapurkar (1978).