Further evaluation of physical fitness age versus physiological age in women

The present study was conducted to examine further whether adult women who are in a state of high physical fitness possess high physiological functions, and also to investigate whether those who exercise regularly are able to maintain a high quality of various physiological functions. The subjects of this study were 249 healthy Japanese adult women (aged 20–70 years). Of these subjects 30 had jogged or walked regularly for more than 3 years. The physiological ages (PA) and physical fitness ages (FA) of the individuals were estimated from 17 physiological function tests and 5 physical fitness tests, respectively, by principal components analyses. The results indicated that there was a significant correlation between PA and FA (r = 0.76, P < 0.01). To examine this relationship in more detail, the subjects were classified into three physical fitness groups (high, normal and low) based on the deviation from the regression line of FA. Comparison of the mean PA among three physical fitness groups revealed that the high physical fitness groups demonstrated a much lower PA (physiologically younger), while the low physical fitness groups showed a relatively higher PA (physiologically older) in spite of their equivalent chronological ages. From this series of studies, a new concept is proposed where different individuals have different peak physiological capacities, but that these capacities change with age at similar rates. It is suggested that interventions such as exercise and a proper diet for promoting health could increase peak functional capacity but have little effect on the rate of decline. Accepted: 3 March 1998     

Effects of war aggression in Croatia on some forms and manifestations of breast cancer

The aim of this study was to determine the differences in epidemiological and clinical manifestations of breast cancer in time of war in Croatia and in peacetime before and after the war, in the defined population of Pozesko-Slavonska County. The methods used in this study were the evaluation of relative predictive value of variables by means of chi 2-test and the analysis of variance, while the survival studies were tested by Long Rank test according to Kaplan-Meier analysis of survival. This work encompasses 660 patients who had breast cancer. The differences between three time periods were evaluated: the war period (1991-1995), and two control periods: before the war (1981-1990) and after the war (1996-2000). The patients were grouped by age, localization of tumor and survival. During the war period the patients were, on the average, 4.2 years younger than those who acquired the disease in control periods, and the mean age of patients was between 50 and 59 years (36.5% of patients). Although the difference in tumor distribution by sides (left or right breast) and quadrants was statistically significant (war period vs. control periods; p < 0.001), there was no statistically significant difference in the survival of patients according to the results of Kaplan-Meier analysis of localization of tumor (p > 0.05). The length of survival in terms of age of patients in time of surgical procedure was significantly different (p < 0.001). This study confirms the effects of war on some epidemiological and clinical manifestation of breast cancer in the defined population of Pozesko-Slavonska County.     

Radiation Therapy in the Treatment of Carcinoma of the Lung

In Ontario in the past 25 years, the death rate from cancer of the lung has shown a substantial increase, ninefold for males and twofold for females. The male:female ratio varied from an average of 8.5:1 to as high as 11.7:1 at the ages 65 to 69. From 1938 to 1958, one-quarter of the total cases (2457) were treated in Ontario Cancer Clinics. Survival rates were: for one year, 20%; three years, 6.5%, and for five years, 3.8%. Fifty-four per cent of surgically treated patients and 63% treated by resection and radiotherapy were alive one year after treatment. Of 821 cases treated with orthovoltage the one-year survival rate was 14%, and of 862 cases treated with cobalt therapy, 23%. It was concluded that this improvement in results may be attributed to the difference in treatment.     

Adaptations of heart activity to physical exercise in female physical education teachers in the European North

Characteristics of heart activity were studied in female residents of the European North with ages between 25 and 59 years who were adapted to physical exercise. The results of studies of the biological age and the degree of training are presented. The mechanisms of adaptation and the specific features of the cardiovascular system (CVS) response to physical exercise depending on the duration of professional experience of subjects were determined. The greatest changes in the functional CVS characteristics were observed in the youngest (25–35 years) and oldest (46–59 years) subjects. This was shown to depend on the type of adaptation, age-specific characteristics, and moderately severe climatic conditions. Comparison of groups of subjects with different durations of professional experience showed that the speed of nervous processes decreased, the regulation of blood circulation became inert, and age-related shifts in some of the variables accelerated. These changes are considered to be the result of an increased expenditure of the physiological reserves of the body under different environmental conditions.     

The Premedical Education of the First-Year Class in Canadian Medical Schools: 1965-66

The premedical academic records of the 1965-66 entering class of Canadian medical students were analysed. Ninety-six per cent of the class had taken their preparation in a Canadian institution, while 80% had taken it in the same university as the medical school in which they enrolled. Forty per cent entered without a degree, the remainder having at least a bachelor''s degree in arts or science.Thirty-six per cent of all courses taken by these students in their premedical education were in the physical sciences, 22% in the biological sciences and 41% in the social sciences and humanities. One-third of the students had taken no course in the behavioural sciences and another third had taken only one course.Analysis of the level of performance of the entering class showed that 10% had obtained an A average, 49% a B average, 41% a C average and 3% a D average. The grades of these students were higher generally in the natural sciences than in the social sciences or humanities.It was concluded that it could be questioned whether medical students received a premedical preparation which met the philosophy of a “broad, liberal education”.     

人文素质教育与医学免疫学专业教育的整合

当前,人们的健康观念和生活方式发生了改变,对医疗卫生服务的需要和期望也发生了变化。然而,医学教育长期以来过分注重医学生的专业知识教育而忽视了人文素质教育,这使得医学生缺乏爱伤观念,对待病人冷漠、和不负责任,功利心较重,缺少奉献精神,从而加剧了医患关系紧张。因此,把医学生人文教育渗透到医学生专业学习的各个过程,使人文素质教育与医学专业教育完美的整合,才能培养出同时具有精湛医术和人文智慧、德才兼备的医生。医学免疫学是生命科学的前沿学科,是联系基础医学和临床医学的桥梁学科之一,也是医学本科生的一门重要的主干课程,其理论和实验技术发展迅猛。本文从医学免疫学专业理论课、实验课、考核等不同环节探讨了人文素质教育和医学免疫学专业教育的整合,进一步地寻找医学免疫学教学中人文素质教育的有效途径,为医学生的人文素质的全面提高提供有益的支持。     

Late deaths and survival after childhood cancer: implications for cure.

OBJECTIVES--To investigate causes of death and survival in subjects who had survived at least five years after diagnosis of childhood cancer; to compare observed mortality with that expected in the general population; and to compare results with a corresponding cohort diagnosed earlier. DESIGN--Retrospective cohort study. SETTING--Population based National Register of Childhood Tumours. SUBJECTS--9080 five year survivors of childhood cancer diagnosed in Britain during 1971-85, of whom 793 had died. Comparison with corresponding cohort diagnosed during 1940-70. MAIN OUTCOME MEASURES--Cause of death established from all available sources of information (including hospital and general practitioner records and postmortem reports) and underlying cause of death coded on death certificate. RESULTS--Of the 781 deaths for which sufficient information was available, death was attributed to recurrent tumour in 578 (74%) cases, treatment related effect in 121 (15%), second primary tumour in 52 (7%), and other causes in 30 (4%). Comparison of observed mortality with that expected in the general population indicated a fourfold excess of deaths from non-neoplastic causes. The risk of dying of recurrent tumour in the next 10 years after surviving five years from diagnosis during 1940-70 and 1971-85 fell from 12% to 8%. The risk of dying from a treatment related effect increased slightly from 1% to 2%. CONCLUSION--Improvements in five year survival after childhood cancer have been accompanied by a reduction in risk of dying from recurrent tumour during the subsequent 10 years and by a slight increase in risk of dying from treatment related effects. The results provide information relevant to decisions concerning balance between effective treatments and their potentially harmful effects.     

Age-related survival in female Sparrowhawks Accipiter nisus

Long-term capture-recapture of female Sparrowhawks Accipiter nisus nesting in three different areas enabled age-related survival rates to be calculated, after correcting for age-related and annual variations in recapture frequency. The data provided strong evidence for an improvement in survival rates in the first 3 years of life and for a decline in the last 5–6 years, during a maximum life span of around 10 years. The decline in survival among older birds was attributed to senescence. At all ages, survival rates were higher in the English area, where breeding numbers were rapidly increasing, than in two Scottish areas, where breeding numbers were stable or declining. The precise pattern of change in survival rates with age may vary between areas, according to prevailing circumstances.     

Mortality among doctors in different occupations.

A total of 20540 male doctors who replied to a questionnaire on their smoking habits that was sent to them on 1 November 1951, and who were aged 35 years and over, were classified according to their occupation as listed in the Medical Directory for 1952 and followed up until 1 November 1971. Examination of the mortality rates in 11 occupational groups showed gross heterogeneity for smoking-related diseases but not for all other diseases grouped together. On average, general practitioners smoked 37% more cigarettes than did hospital physicians and surgeons and the overall death rates among general practitioners were about 23% higher than among physicians and surgeons of similar ages. This excess death rate was chiefly accounted for by a 38% excess mortality from smoking-related diseases such as lung cancer, chronic bronchitis, and ischaemic and pulmonary heart disease. The few other statistically significant associations between occupation and disease were thought to be due either to chance or to the effect of the disease on the choice of specialty.     

Seasonal programming of adult longevity in Ukraine

Longevity was significantly associated with season of birth in 101,634 individuals who died in Kiev during the period 1990-2000. The relationship between age at death and month of birth showed a very similar pattern for both men and women. Mean values for the age at death were lowest for subjects born in April-July, and highest for individuals born at the beginning and end of the year. Minimum and maximum ages at death, analysed according to month of birth, differed by 2.6 years in men and 2.3 years in women. For all major causes of death causes, the mean age at death for persons born in the fourth quarter was the highest. These results suggest that, in this population, longevity is affected by prenatal or early postnatal seasonal factors. This is consistent with the hypothesis that the rate of ageing may be programmed in response to environmental influences at critical periods of early development.     

Bayesian inference on age-specific survival for censored and truncated data

1. Traditional estimation of age-specific survival and mortality rates in vertebrates is limited to individuals with known age. Although this subject has been studied extensively using effective capture-recapture and capture-recovery models, inference remains challenging because of large numbers of incomplete records (i.e. unknown age of many individuals) and because of the inadequate duration of the studies. 2. Here, we present a hierarchical model for capture-recapture/recovery (CRR) data sets with large proportions of unknown times of birth and death. The model uses a Bayesian framework to draw inference on population-level age-specific demographic rates using parametric survival functions and applies this information to reconstruct times of birth and death for individuals with unknown age. 3. We simulated a set of CRR data sets with varying study span and proportions of individuals with known age, and varying recapture and recovery probabilities. We used these data sets to compare our method to a traditional CRR model, which requires knowledge of individual ages. Subsequently, we applied our method to a subset of a long-term CRR data set on Soay sheep. 4. Our results show that this method performs better than the common CRR model when sample sizes are low. Still, our model is sensitive to the choice of priors with low recapture probability and short studies. In such cases, priors that overestimate survival perform better than those that underestimate it. Also, the model was able to estimate accurately ages at death for Soay sheep, with an average error of 0.94 years and to identify differences in mortality rate between sexes. 5. Although many of the problems in the estimation of age-specific survival can be reduced through more efficient sampling schemes, most ecological data sets are still sparse and with a large proportion of missing records. Thus, improved sampling needs still to be combined with statistical models capable of overcoming the unavoidable limitations of any fieldwork. We show that our approach provides reliable estimates of parameters and unknown times of birth and death even with the most incomplete data sets while being flexible enough to accommodate multiple recapture probabilities and covariates.     

Mortality associated with HIV-1 infection over five years in a rural Ugandan population: cohort study.

OBJECTIVE: To assess the impact of HIV-1 infection on mortality over five years in a rural Ugandan population. DESIGN: Longitudinal cohort study followed up annually by a house to house census and medical survey. SETTING: Rural population in south west Uganda. SUBJECTS: About 10,000 people from 15 villages who were enrolled in 1989-90 or later. MAIN OUTCOME MEASURES: Number of deaths from all causes, death rates, mortality fraction attributable to HIV-1 infection. RESULTS: Of 9777 people resident in the study area in 1989-90, 8833 (90%) had an unambiguous result on testing for HIV-1 antibody; throughout the period of follow up adult seroprevalence was about 8%. During 35,083 person years of follow up, 459 deaths occurred, 273 in seronegative subjects and 186 in seropositive subjects, corresponding to standardised death rates of 8.1 and 129.3 per 1000 person years. Standardised death rates for adults were 10.4 (95% confidence interval 9.0 to 11.8) and 114.0 (93.2 to 134.8) per 1000 person years respectively. The mortality fraction attributable to HIV-1 infection was 41% for adults and was in excess of 70% for men aged 25-44 and women aged 20-44 years. Median survival from time of enrollment was less than three years in subjects aged 55 years or more who were infected with HIV-1. Life expectancy from birth in the total population resident at any time was estimated to be 42.5 years (41.4 years in men; 43.5 years in women), which compares with 58.3 years (56.5 years in men; 60.5 years in women) in people known to be seronegative. CONCLUSIONS: These data confirm that in a rural African population HIV-1 infection is associated with high death rates and a substantial reduction in life expectancy.     

Biochemistry,Coming Along with Melodies: Instructional Design and Teaching Tips for Introduction of Biochemistry Course

The first class of a higher education course, in most cases, is an introduction that covers the learning goals, course overview, syllabus, and evaluation mode. The effectiveness of an introduction lecture is vital for students to develop an interest in the course. Biochemistry is the foundation of a vast array of scientific disciplines; therefore, it is a core course required for medical schools and life science majors. However, many students are often intimidated by the complex, intertwined metabolic pathways composed of a great variety of structurally diverse biomolecules. Well begun is half done: a good introduction is essential for the success of a course and this is particularly true for teaching of biochemistry. As an educator with over twenty years of teaching experience in biochemistry to students of biology, medicine, pharmacy, and nursing at Peking University, I have successfully enriched the introduction class with delightful biochemistry songs, multiple sources of educational materials, and biochemistry-related knowledge in medical humanities. These strategies and tips have proven effective, and I hope it can be enlightening and helpful to the teaching of biochemistry.     

Variation of annual apparent survival and detection rates with age,year and individual identity in male Weddell seals (Leptonychotes weddellii) from long-term mark-recapture data

Exploring age- and sex-specific survival rates provides insight regarding population behavior and life-history trait evolution. However, our understanding of how age-specific patterns of survival, including actuarial senescence, compare between the sexes remains inadequate. Using 36 years of mark-recapture data for 7,516 male Weddell seals (Leptonychotes weddellii) born in Erebus Bay, Antarctica, we estimated age-specific annual survival rates using a hierarchical model for mark-recapture data in a Bayesian framework. Our male survival estimates were moderate for pups and yearlings, highest for 2-year-olds, and gradually declined with age thereafter such that the oldest animals observed had the lowest rates of any age. Reports of senescence in other wildlife populations of species with similar longevity occurred at older ages than those presented here. When compared to recently published estimates for reproductive Weddell seal females, we found that peak survival rates were similar (males: 0.94, 95% CI = 0.92–0.96; females: 0.92, 95% CI = 0.93–0.95), but survival rates at older ages were lower in males. Age-specific male Weddell seal survival rates varied across years and individuals, with greater variation occurring across years. Similar studies on a broad range of species are needed to contextualize these results for a better understanding of the variation in senescence patterns between the sexes of the same species, but our study adds information for a marine mammal species to a research topic dominated by avian and ungulate species.     

Child survival and its effect on mortality of siblings in Bangladesh

This study of the relationship between mortality risks of siblings born to the same mother shows that, in Bangladesh, the death of the immediately preceding sibling in its infancy has a negative influence on the survival chance of the child in question in its infancy; however, death of the preceding sibling appears to have a positive influence on the index child's survival at ages 1-5 years. Similar results are found for the survival status of the two preceding siblings. Preceding birth interval length and survival status and sex of the immediately preceding sibling are also significant predictors of child mortality between ages 1 and 5 years. Possible explanations may be that the index child faces stronger competition from its immediately preceding brother than from its immediately preceding sister, or that the index child is likely to be looked after more by its preceding sister than by its preceding brother.     

Elementary and middle level biology topics: a content analysis of Science and Children and Science Scope from 1990 to 2014

Science and Children and Science Scope are peer-reviewed science practitioner journals that publish articles for science educators who teach children of ages 5–10 years and 10–13 years, respectively. As such, these articles are a reflection of the science concepts that are being communicated to science educators. This comprehensive literature review was completed to determine the extent to which the articles included in these journals from 1990 to 2014 focused on biology topics, incorporated other non-science subjects and science disciplines, and encouraged inquiry-based learning. The results indicate that out of the 2701 total articles, 557 (21%) focused on biology. The biology topic covered most often by both journals was animals. The biology topics covered least often were fungi, photosynthesis, respiration and viruses. The findings are taken into consideration and the educational implications for the journals and educators are discussed.     

Novel features of computer-simulated clonal life of Paramecium caudatum

The clone of the ciliated protozoan Paramecium caudatum has the immaturity period of about 60 fissions and the lifespan of about 600 fissions. These life cycle figures have been depicted through laboratory experiments that allow continuous cell divisions for hundreds, which never occur in nature. We here constructed the nature-mimicking model culture that alternated the log- and stationary phases to allow conjugation, and computer-simulated the age structure modifying parameters such as cell distributions to start the culture, fission rates, death rates, immaturity periods, probabilities of conjugation, proportions of transplantation and so on. The average and maximum ages in the culture after thousands of alternations were converged to 43±2 and 140±5 fissions, respectively, when parameters for the immaturity period and the maximum clonal lifespan were set at 60 and 600 fissions. This result explains why cells collected in nature are usually young and vigorous. The average and maximum ages proportionally prolonged as the immaturity period was prolonged, as reported true for species of the ciliate. These results indicate the validity of our simulation. The average and maximum ages remained unchanged when the initial condition for starting the culture was changed from two complementary mating-type cells to a population with a quadratic-function distribution, and when the fission rate at the log-phase and the death rate at the stationary phase were modified for older ages. The average and maximum ages changed slightly when either the conjugation rate or the proportion of transplantation was somewhat lowered. Although they changed considerably when such parameters as the immaturity period, conjugation rate and death rate were extremely modified, no clones with the age over 230 fissions appeared in any simulations. These results indicate the robustness of the model, which provides us with fresh insight into the structural system of the clonal lifespan of P. caudatum in nature.     

SURVIVORSHIP PATTERNS IN THREE SPECIES OF CAPTIVE CETACEANS

Survival rates for three species of captive cetaceans are reported, based on records of dates of capture, birth, and death of individual animals. The annual survival rate was 0.93 for bottlenose dolphins and killer whales and 0.94 for white whales. Confidence limits of these estimates are discussed. Differences in survival rates between institutions were significant for bottlenose dolphins only. Calf survival for bottlenose dolphins was lower than non-calf survival. Survivorship of male killer whales was significantly less than survivorship of female killer whales; sex-specific survival rates were similar for the other two species. Estimates of average or maximum longevity alone were not useful in comparing rates of survival. Because survival in the first year of captivity may be lower than subsequent years, estimates of the expected lifespan, based on data from the first few years of captivity, may be biased.