On the Influence of p-Nitroacetophenone on Radiation-Induced Molecular Size Changes of DNA

DNA has been irradiated in aqueous solutions with 16 MeV electron pulses (duration: 50- 100 ns). In the presence of p-nitroacetophenone (PNAP) the light scattering intensity (LSI) increased after the pulse in Ar- and 02-saturated solutions indicating intermolecular crosslinking. The LSI increase was greatest in Ar-sat. solutions containing t-butanol (1 mol/1). In the absence of PNAP and t-butanol DNA was degraded as indicated by a decrease of LSI. The results contribute to the understanding of radiation-induced reactions, DNA undergoes in the presence of sensitizers of high electron affinity

Response of parathyroid hormone to exercise and bone mineral density in adolescent female athletes

BACKGROUND

This study investigates 1) the effects of amount of exercise on levels of serum parathyroid hormone (PTH) and calcium, and 2) the relationship between PTH response and bone mineral density in adolescent female athletes.

SUBJECTS

Twenty-one female athletes on a top-ranked high school basketball team in Japan participated in a one-month intensive basketball program. Subjects were divided into moderate-exercise and strenuous-exercise groups.

METHODS

The amount of exercise was quantified using estimated metabolic equivalent (METs) and exercise hours. Levels of serum intact-PTH and calcium were examined five times: twice before training to establish a baseline (T(-1) and T(0)), once 3rd week of the training period (T(1), once immediately at the end of the program (T(2)), and again one week later(3)). Bone mineral density of forearm (distal-BMD) was measured one week after the end of the program. PTH levels at T(1), T(2) and(3) were regressed on PTH at baseline (T(0)) for both groups and examined for statistical significance. Multiple regression analyses of the changes of PTH and distal-BMD were conducted.

RESULTS

1) Strenuous-exercise subjects showed both increased and decreased PTH levels, while moderate-exercise subjects showed a uniform decrease in PTH throughout the exercise period. 2) Increased PTH was an independent negative predictor of distal-BMD, while high lean body mass, increased serum Ca, and exercise volume were positive predictors.

CONCLUSION

The amount of exercise affects PTH response: moderate exercise suppresses PTH secretion, while strenuous exercise is apt to induce continuous secretion, which has a negative effect on BMD.

Reliability and validity of Kasahara's scale of melancholic type of personality (Typus melancholicus) in a German sample population

We explored the reliability and validity of Kasahara's scale of melancholic type of personality (KMT) in a German sample population. Subjects comprised 66 patients diagnosed with an affective disorder (F3, ICD-10) and 94 controls. Concerning reliability, KMT scores showed internal consistency with Cronbach's alpha coefficients of 0.65 for patients and 0.67 for controls. The KMT items, except for number 13 in controls, showed significant item-total correlations. In a test-retest procedure, the KMT total score and individual item scores were statistically similar and correlated. These results indicate reliability of the KMT. Concerning validity, KMT scores were significantly higher in patients than in controls. By controlling the effects of age and sex, partial correlation coefficients in a comparison of KMT and Zerssen's F-List (F-List) scores were 0.40 in patients and 0.53 in controls. These results show both the constructive and concurrent validity of the KMT. Sufficient reliability and validity of the KMT were shown in this German sample population to encourage cross-cultural investigation of Typus melancholicus.

Mental health problems after stroke

We investigated the mental health of 47 subjects (30 men, mean age 63.8+/-7.7; 17 women, mean age 68.9+/-8.7) with the 60-item General Health Questionnaire (GHQ). All the subjects lived at home in a Japanese rural community and were examined from 2 to 3 years after suffering a stroke. Among the subjects, 18 (38.3%) had GHQ scores of 17 or more, which indicated a mental health problem (MHP). The following variables were included in multiple logistic regression analysis: age, sex (men/women), grade of motor paralysis (no/slight/moderate/severe), side of motor paralysis (no/left side/right side/both sides: in analysis, we used dummy variables), paresthesia (no/yes), rehabilitation (need no rehabilitation or participate in rehabilitation/fail to participate in rehabilitation), social support (not needed or sufficient/insufficient) and overall physical recovery (1/2/3: 1 = 67-100, 2 = 34-66, and 3 = 0-33 on a visual analog scale 100 mm long, 100 meaning full recovery). In univariate analysis all variables except age and sex showed statistically significant associations with MHP. In multivariate analysis, only one variable, overall physical recovery', had a statistically independent association with the status of MHP (Odds ratio 4.39, 95% confidence interval 1.46-13.19). The results of logistic regression analysis indicate that the presence of an MHP is more strongly dependent upon subjective assessment about overall physical recovery after stroke than upon physical impairments and the other psychosocial variables. Therefore, in the community setting, the visual analog scale of overall physical recovery is considered to be a simple, valid method for assessing MHP following stroke.

Significance of the atherosclerogenic index and body fat in children as markers for future, potential coronary heart disease

BACKGROUND

The purpose of this study is to establish a simple marker in children for future, potential risks of coronary heart disease.

METHODS

We measured serum total cholesterol (TC) and triglyceride (TG) by enzymatic methods, high-density lipoprotein cholesterol (HDLC) by the dextran sulfate-magnesium method and estimated body fat by the new impedance method in 1289 children (651 boys and 638 girls) in the fourth grade (9 or 10 years old) to obtain the atherosclerogenic index (AI). We also investigated the children's lifestyle.

RESULTS

The probability of an AI score of 3 or more was significantly higher in children with an estimated 23-25% body fat than in those with body fat less than 17%. Moreover, the odds ratio increased along with an increase in the percentage of body fat. When body fat was estimated as being greater than 29%, the odds ratio was 11-fold higher than those with body fat less than 17%. When body fat was greater than 23%, the children's physical activity, as assessed by the questionnaire, was found to be poorer than those with lower body fat. Levels of TC and TG were significantly higher and that of HDLC was lower in those with less body fat.

CONCLUSIONS

The AI is a useful indicator of obesity in children. The combination of AI and percentage body fat is a good indicator for evaluating children who would be at a greater risk of obesity, hyperlipidemia, unhealthy eating habits and inadequate physical activity. The hypothetical risk levels for future coronary heart disease are an AI score of > or = 3 and percentage body fat > or = 23% in Japanese children.

The accelerated increase in lean body mass of pre-pubescent Japanese boys at 10 to 11 years of age

The present study investigated changes in body composition in relation to growth to evaluate at what age Japanese children begin their pre-pubescent growth spurt. Children aged 9 were followed to age 10 (The age 9 group), and those aged 10 were followed to age 11 (The age 10 group). The increase in lean body mass per one-year increment of body height (Δ LBM/ ΔBH) in the age 10 boys group was significantly higher than that in the age 9 boys group. In both the age 9 and 10 boys groups, the high Body Mass Index (BMI) boys showed greater mean ΔLBM/ ΔBH than that for the normal BMI boys. Our results of accelerated Δ LBM/ ΔBH from age 10 to 11 in Japanese boys hypothesize that an increase in LBM demonstrates pre-pubescent growth.

How do the Japanese medical students evaluate the effectiveness of anti-smoking strategies?- an application of the Analytic Hierarchy Process

In order to establish the effective strategies to reduce the smoking prevalence among teenagers in Japan, the author evaluated opinions of the 30 male medical students with smoking habit by the Analytic Hierarchy Process (AHP) method. In the AHP model, the six factors are considered to be important for the onset of teenagers smoking; smoking habit of peers, smoking habit of family members, tobacco advertising, convenience to buy cigarettes, social acceptance of smoking and knowledge of harmful effects of smoking, and the five strategies are proposed; tobacco advertising ban, higher pricing of tobacco, promotion of antismoking education, regulation on tobacco sales, and regulation on smoking area. According to the medical students' perspective, the strategy of "higher pricing of tobacco" was considered to be the most effective strategy to reduce the smoking incidence of the teenagers, followed by "regulation on tobacco sales", "promotion of anti-smoking education", "regulation on smoking area", and "tobacco advertising ban"

Eating habits, activity, lipids and body mass index in Japanese children: the Shiratori Children Study

OBJECTIVE

To describe the eating habits and physical activity of Japanese children aged 10 y, and to investigate their relationship to lipids and body mass index (BMI); also to study the relationship between BMI and lipids in these children.

DESIGN

This was a cross-sectional study conducted at six schools in Shiratori, Japan during 1992-1994. Physical examinations and questionnaires were used to collect data from 457 fifth grade children, aged 10 y.

RESULTS

The diet of these children was mixed, with Japanese and Western foods almost equally reported. Boys were more active than girls. More active children had higher high density lipoprotein cholesterol (HDL-C), and children who ate a more Japanese diet had slightly lower HDL-C. BMI was positively related to cholesterol, low density lipoprotein cholesterol (LDL-C), triglycerides and inversely related to HDL-C. The amount of rice intake was positively associated with the BMI of these children.

CONCLUSION

In our study of Japanese children aged 10 y, their diets were fairly Westernized, and most children were fairly inactive based on our activity score. Although obesity is low in these young Japanese subjects (14.1%), children who were obese (BMI>20) had worse lipid profiles than those who were not obese. An exceptionally high rice intake was associated with obesity, and thus may be an early warning sign for future obesity.

Response of parathyroid hormone to anaerobic exercise in adolescent female athletes

It has been shown that moderate exercise suppresses parathyroid hormone (PTH) secretion, while strenuous exercise is apt to induce continuous secretion, which has a negative effect on bone mineral densities (BMD). The present study investigated a typical response of PTH to brief exercise. The study group comprised six adolescent female basketball players whose BMD were within normal limits. Maximal anaerobic power by three-step cycling was loaded on each subject. The first blood sample was drawn 30 min prior to testing test, the second was immediately following, the third was 15 min after, and the fourth was 30 min after. The proportional change in plasma volume was -11.5% immediately following (P < 0.05), +2.1% 15 min after, and +5.5% at 30 min after exercise (P < 0.05). The expected value was calculated on the assumption of no effect, except changes in plasma volume, by exercise. The measured values of PTH and calcium (Ca) immediately after exercise were lower than each of the expected values (P < 0.05 for both). At 15 min after, there was no significant difference between expected and measured values of PTH, Ca and magnesium (Mg), respectively. At 30 min after, the measured value of Ca and Mg was higher than each expected value (P < 0.05 for both). It was concluded that PTH secretion is suppressed transiently immediately after maximal anaerobic exercise and is then stimulated during the recovery time in normal BMD subjects.

[An evaluation of the biting force, the body composition and the amount of masticatory action in young females]

The purposes of this study were to investigate factors related to maximum biting force and to understand the characteristics of physical properties of daily ingested foods in young females. One hundred and forty subjects aged 18-23, with Angle 1 class occlusion, had not suffered from periodontitis, and had not been treated for preparation of tooth crown of first molars. Body height and weight were measured, and percentage of body fat, fat mass (FM) and lean body mass (LBM) were estimated, using the impedance analyzer. The maximum biting force was measured by the press sensation method. According to the formula on the basis of our new version of Yanagisawa's food classification, the mean value of the amount of masticatory action for one day was calculated. Subjects were divided into the normal biting force and the low biting force groups with -1SD of the maximum biting force, in order to compare body composition and backgrounds in sports activities between these two groups. Multiple linear regression analysis was carried out, employing maximum biting force (kg.f) as a dependent variable, and having a background in sports activities, FM, LBM, the number of missing teeth, the number of dental caries and the amount of masticatory action for one day as independent variables. Results were as in the following: 1) The proportion of subjects who had a background in sports activities in the low biting force group were less than that in the normal biting force group (p < 0.01). 2) Having a background in sports activities and LBM were positively correlated to maximum biting force (p < 0.01), while the amount of masticatory action for one day was not. 3) All subjects, especially those in the low biting force group seldom had food requiring the highest amount of masticatory action.

CONCLUSION

Having a background in sports activities and LBM are positively correlated with the maximum biting force, while the amount of masticatory action for one day was not correlated positively nor negatively in young females.

Risk factors for low bone mineral density among females: the effect of lean body mass

BACKGROUND

This study determines if body composition and lifestyle are risk factors for low radius-bone mineral density (R-BMD) and evaluates the role of body composition in the age-related decline of R-BMD.

METHODS

Data on age, menopausal status, fat mass, lean body mass (LBM), drinking, smoking, and occupation were collected from 3,867 females ages 37-69, whose R-BMD was also measured. Multiple logistic regression analyses examined the predictive accuracy of these factors for low (20th percentile) R-BMD.

RESULTS

Age, LBM, and menopausal status were risk factors for the 37-55 age group, while age, LBM, and lifestyle (alcohol consumption 3 or fewer days per week and currently smoking) were risk factors for the 56-69 age group. The odds ratio (OR) for LBM was nearly reciprocal to the ORs for age and for menopausal status. Our model has low sensitivity, high specificity, low positive predictive value, and high negative predictive value.

CONCLUSIONS

Consumption of alcohol 3 or fewer days per week and being a current smoker have a negative effect on R-BMD among older (56-69) women. The positive effect of LBM on R-BMD continues from age 37 on LBM has an effect almost equal but opposite to those of aging and menopause on the risk of low R-BMD. High LBM after age 37 predicts normal R-BMD.

Acceleration plethysmography to evaluate aging effect in cardiovascular system. Using new criteria of four wave patterns

Acceleration plethysmography (APG) uses the second derivative of the waveform of the digital photoplethysmography to stabilize the baseline and to separate components of the waveform more clearly than the first derivative. The purposes of this study were 1) to investigate the association between APG and aging, using our new criteria of four patterns and 2) to test the clinical usefulness of APG for the prediction of the level of atherosclerosis. The examined subjects were 82 males and 308 females aged 30-69 years. Plethysmograms were recorded in the sitting position. We compared the distribution of four patterns of APG by age group and analyzed the predictor of changing waveforms. We also analyzed the association between wave patterns and the risk factors, i.e. total cholesterol (TC), high density lipoprotein cholesterol, systolic blood pressure, diastolic blood pressure, body mass index, and current smoking status.

THE RESULTS

-categorized four wave patterns were significantly associated with aging; -pulse pressure (PP), body height and sex influenced waveforms of APG independently of age; and -categorized wave patterns were associated with high serum TC among risk factors for atherosclerosis. Those results suggest that APG reflects the arterial wall properties which change with age and might predict the level of atherosclerosis. To provide further guidance for determining appropriate clinical interpretations of APG, it is required to consider the effects of PP, body height and sex. We conclude that simply categorized wave patterns of APG could be a useful noninvasive tool to evaluate aging in cardiovascular system.

[Effects of exercise on immune functions in mice]

This study was carried out to examine the effects of forced running exercise on the immune functions of male ICR mice. Mice aged 4 weeks were divided into two groups: a non-exercise group (control) and a group given forced running exercise (exercise group). The exercise applied was forced running at 15m/min on a flat floor without any slope for 60 min a day. The duration of exercise was 5 days per week for 12 weeks. The results obtained were as follows: 1) After 12 weeks of forced running exercise, the weight of the anterior tibialis muscle and succinate dehydrogenase activity in the anterior tibialis muscle increased significantly (p < 0.01) in the exercise group compared with the control group. A tendency for thymus weight to increase was shown in the exercise group, and liver and spleen weights were significantly (p < 0.01) greater than in the control group. 2) The potentiation of phagocytic function of the reticulo-endothelial system, examined by the carbon clearance method, was seen in the exercise group. 3) The ability of peritoneal macrophages (M phi) to phagocytose latex beads significantly increased (p < 0.01) in the exercise group. The acid phosphatase activity of peritoneal M phi remained in both groups. However, lactate dehydrogenase activity of peritoneal M phi significantly increased (p < 0.01) in the exercise group compared with the control group. 4) The proliferation of splenocytes induced by Con A in the exercise group significantly increased (p < 0.01) compared with the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiation-induced strand breakage in poly(riboadenylic acid). A pulse radiolysis study on the protective action of cysteamine under anoxic conditions

Poly(riboadenylic acid) was irradiated in N2O-saturated dilute aqueous solution at pH 7.8 with single pulses (50-200 ns) of 16 MeV electrons. With the aid of Rayleigh light scattering measurements both the extent and rate of main-chain scission were measured in the absence and the presence of cysteamine (RSH). In both cases two modes of light scattering intensity (LSI) decrease were detected. From this finding it was concluded that two chemically different radical sites, giving rise to main-chain breakage, were produced by OH attack on the macromolecules. Cysteamine reduced the extent of LSI decrease and accelerated the rate of the slow mode of LSI decrease significantly. The fast mode of the LSI decrease is due to fragment diffusion and therefore the influence of cysteamine on the rate of decay of the short-lived radical could not be studied. The assessment of the relative importance of .OH scavenging (RSH + .OH----RS. + H2O) and of repair (PA. + RSH----PAH + RS.) with respect to protection yielded the following: in the case of the long-lived radical, repair contributes significantly at low RSH concentration (less than 10(-4) M); in the case of the short-lived radical, OH scavenging dominates and repair becomes noticeable only at [RSH] greater than 10(-4)M. The following data were evaluated in this work: 100 eV-yield of main-chain scission, G(sb) = 1.1; lifetimes of radicals: less than 50 microseconds (short-lived), 0.6 s (long-lived), kPA. + RSH = 3.4 X 10(6)M-1 S-1 (for long-lived radicals).

OH radical-induced main-chain scission of poly(ribonucleic acids) under anoxic conditions

Poly(ribonucleic acids), poly A, poly C and poly U, were irradiated in O2-free dilute aqueous solution at pH 7 to 8 with single pulses (50 to 200 ns) of 16 MeV electrons. With the aid of Rayleigh light scattering measurements main-chain scission, induced by OH radicals, was observed with the three polynucleotides. From the time dependence of the decrease of the light scattering intensity (LSI), the existence of two modes of decrease was inferred, indicating at least two different chemical mechanisms were operative in main-chain degradation. Evidence for the assignment of the slow mode of LSI decrease to the lifetime of a free radical was obtained from quenching experiments with cysteamine. It is noteworthy, that the extent and the lifetime of LSI decrease are not the same for the three polynucleotides. The differences indicate the influence of the chemical nature of the bases on main-chain scission. Consequently, it is concluded that OH attack at carbons in 1' and/or 2' position of the ribose moiety contributes essentially to the degradation mechanism.

Radiation-induced molecular size changes in DNA in the presence of p-nitroacetophenone. Pulse radiolysis in conjunction with light-scattering measurements

Native calf thymus DNA, denatured DNA, and synthetic nucleic acids (poly A, poly C, poly U, and poly G) crosslink upon irradiation with 16 MeV electrons in O2-free dilute aqueous solutions containing 0.5mol/l t-butanol and p-nitroacetophenone (PNAP) or nitrobenzene at concentrations between 10(-4) to 10(-3) mol/l. The occurrence of crosslinking was inferred from the increase of the light-scattering intensity after the irradiation with a 100ns electron pulse. The mechanism of crosslinking is based on the indirect action of radiation, typical 100eV yields G(X) being between 10(-5) and 10(-4). The attack of unsaturations in pendant bases by anion radicals PNAP- or by dimer anion radicals (PNAP)2 radical leading to pendant macroradicals appears to be feasible. Combination of the latter causes crosslinkages. Rate constants and yields of crosslinking depend strongly on the ionic strength. Evidence for counteracting kinetic salt- and steric hindrance effects has been obtained.