De novo mutations producing unstable hemoglobins or hemoglobins M

Summary Hemoglobins M and unstable hemoglobins cause clinical syndromes that are transmitted in autosomal dominant fashion. Pedigrees of 50 probands with de novo mutations producing unstable Hb disease or Hb M disease were compiled. Cases were ascertained (1) by screening the relevant literature published from 1950 through 1980 and (2) through personal communication. Additional pedigree data on several published cases were collected, and a depository containing all available information rekated to de novo Hb mutants was established. The 50 probands were born in 14 countries between 1922 and 1976. Paternity was tested in 36% of the cases, and no instance of false paternity was noted.The data were used to test for an association of advanced parental age with the appearance of de novo mutants. Paternal ages at the probands' births ranged from 20 to 50 years, with a mean of 32.7 years. Maternal ages ranged from 18 to 43 years, with a mean of 28.5 years. For each year and country (or, where necessary, for the nearest possible year and/or a demographically similar country), the cumulative frequency distributions of the ages of parents who had a child in that country and year were computed; the ages of each proband's father and mother were then expressed as percentiles on these distributions. The distribution of paternal age percentiles was shifted toward the upper end of the range, with 11 of the 50 paternal ages falling between the 90th and 100th percentiles. The distribution of maternal age percentiles was more complex, with one peak (10 of 50 ages) falling between the 30th and 40th percentiles and a second peak (10 of 50 ages), between the 90th and 100th percentiles. These distributions, though suggestive of an association of advanced parental age and the appearance of de novo mutations that cause unstable Hb disease or methemoglobinemic cyanosis, were not significantly different from those uniform distributions expected in the absence of a parental age effect.     

穿龙薯蓣种群生命表的研究

通过对吉林省三岔子林业局的野生穿龙薯蓣(Dioscorea nipponica)年龄结构的调查,编制出了其野生种群的静态生命表。结果表明:3~15年间,死亡率非常低。而15年之后,特别是25年之后的死亡率明显升高;年龄结构,在30年之前,各龄级的株数基本符合正态分布规律,而30年之后却偏离了这个规律,表现为各龄级的株数成直线减少;生命期望值在30年之后明显增大。这充分表明了该地区穿龙薯蓣的种群正趋于衰退,该物种日趋濒危。     

Respiratory sequelae of whooping cough. Swansea Research Unit of the Royal College of General Practitioners.

Eight hundred and thirteen children who had had whooping cough when under 5 years of age in the 1977-9 epidemic were compared with a control group roughly four and a half years later, each child being matched by age and sex and from the same class in school. The index group showed long term respiratory sequelae of whooping cough--namely, deterioration in lung function, increase in respiratory symptoms, and increased admission to hospital for both upper and lower respiratory conditions. Asthma was significantly more common in the index group, suggesting that asthma was being regarded as a contraindication to pertussis vaccination. Only 3.5% of the asthmatic children in the index group had been vaccinated as against 29.1% of the controls.     

Effect of Cigarette Smoking and Passive Smoking on Hearing Impairment: Data from a Population–Based Study

Objectives

In the present study, we aimed to determine the effect of both active and passive smoking on the prevalence of the hearing impairment and the hearing thresholds in different age groups through the analysis of data collected from the Korea National Health and Nutrition Examination Survey (KNHANES).

Study Design

Cross-sectional epidemiological study.

Methods

The KNHANES is an ongoing population study that started in 1998. We included a total of 12,935 participants aged ≥19 years in the KNHANES, from 2010 to 2012, in the present study. Pure-tone audiometric (PTA) testing was conducted and the frequencies tested were 0.5, 1, 2, 3, 4, and 6 kHz. Smoking status was categorized into three groups; current smoking group, passive smoking group and non-smoking group.

Results

In the current smoking group, the prevalence of speech-frequency bilateral hearing impairment was increased in ages of 40−69, and the rate of high frequency bilateral hearing impairment was elevated in ages of 30−79. When we investigated the impact of smoking on hearing thresholds, we found that the current smoking group had significantly increased hearing thresholds compared to the passive smoking group and non-smoking groups, across all ages in both speech-relevant and high frequencies. The passive smoking group did not have an elevated prevalence of either speech-frequency bilateral hearing impairment or high frequency bilateral hearing impairment, except in ages of 40s. However, the passive smoking group had higher hearing thresholds than the non-smoking group in the 30s and 40s age groups.

Conclusion

Current smoking was associated with hearing impairment in both speech-relevant frequency and high frequency across all ages. However, except in the ages of 40s, passive smoking was not related to hearing impairment in either speech-relevant or high frequencies.     

X-linked recessive inheritance of sensorineural hearing loss expressed during adolescence.

Eight males in 4 generations with hearing impairment were observed in a kindred; family transmission suggested X-linked recessive inheritance. In previously reported cases of X-linked sensorineural hearing loss, hearing impairment was usually severe to profound and was either present at birth or manifested by 5 years of age.In the present cases, rapid onset of a bilateral sensorineural hearing loss occurred during adolescence and did not generally progress beyond moderate impairment. Significant deterioration in seech production did not usually result.     

“Upper Limits of Normal” Antistreptolysin O and Antideoxyribonuclease B Titers

"Upper limits of normal" antistreptolysin O (ASO) and antideoxyribonuclease (ADN) B titers were determined on serum specimens from various age groups of pediatric patients with no history of a recent streptococcal infection and on healthy adult hospital employees. The upper limit of normal value is that level of antibody titer exceeded by no more than 15% of the total subjects in each age group. This value varies with the age of the subject, and the most pronounced differences are between the values of preschool age children, school age children, and adults. The upper limit of normal values for these groups were as follows: preschool age, ASO = 85(100); ADN B = 60(50); school age, ASO = 170(166); ADN B=1 70(166); and adult, ASO = 85(100); ADN B = 85(100).     

How the scrub height of dwarf pine Pinus pumila decreases at the treeline

Plant height decreases much within narrow altitudinal spans near treelines. We compared the stem age, stem inclination and shoot elongation rates of alpine dwarf pine Pinus pumila between the upper distribution limit (treeline, 2,850 m a.s.l.) and the lower distribution limit (2,500 m a.s.l.) on Mount Norikura in central Japan, to examine how the growth traits of P. pumila change with altitude. The mean stem height at the upper distribution limit (49 cm) was about a quarter of that at the lower distribution limit (187 cm). The mean ratio of stem height to length was lower at the upper distribution limit than at the lower distribution limit, indicating that P. pumila stems inclined more at the higher altitude. The mean stem age at the upper distribution limit (48 years) was less than a half of that at the lower distribution limit (109 years). Although the shoot elongation rate positively correlated with stem length at the two altitudes, the shoot elongation rate at a given stem length was lower at the upper distribution limit than at the lower distribution limit. Thus, less developed scrub at the upper distribution limit than at the lower distribution limit was due to shorter stem age, more creeping stems and lower shoot elongation rates. Generally, wind velocity is greater in higher altitudes. Probably, strong wind reduces the growth and mean stem age of P. pumila stems at the upper distribution limit. Therefore, this study concludes that the scrub height of P. pumila is controlled not only by temperature, but also by strong wind.     

Binaural Fusion and Listening Effort in Children Who Use Bilateral Cochlear Implants: A Psychoacoustic and Pupillometric Study

Bilateral cochlear implants aim to provide hearing to both ears for children who are deaf and promote binaural/spatial hearing. Benefits are limited by mismatched devices and unilaterally-driven development which could compromise the normal integration of left and right ear input. We thus asked whether children hear a fused image (ie. 1 vs 2 sounds) from their bilateral implants and if this “binaural fusion” reduces listening effort. Binaural fusion was assessed by asking 25 deaf children with cochlear implants and 24 peers with normal hearing whether they heard one or two sounds when listening to bilaterally presented acoustic click-trains/electric pulses (250 Hz trains of 36 ms presented at 1 Hz). Reaction times and pupillary changes were recorded simultaneously to measure listening effort. Bilaterally implanted children heard one image of bilateral input less frequently than normal hearing peers, particularly when intensity levels on each side were balanced. Binaural fusion declined as brainstem asymmetries increased and age at implantation decreased. Children implanted later had access to acoustic input prior to implantation due to progressive deterioration of hearing. Increases in both pupil diameter and reaction time occurred as perception of binaural fusion decreased. Results indicate that, without binaural level cues, children have difficulty fusing input from their bilateral implants to perceive one sound which costs them increased listening effort. Brainstem asymmetries exacerbate this issue. By contrast, later implantation, reflecting longer access to bilateral acoustic hearing, may have supported development of auditory pathways underlying binaural fusion. Improved integration of bilateral cochlear implant signals for children is required to improve their binaural hearing.     

Occurrence of Acute Upper Respiratory Diseases among Children as a Result of Infection by Herpes Simplex Virus

One hundred and twenty-one children showing symptoms of acute upper respiratory disease were bled during a period of nine months, from winter to summer, for detection of complement-requiring neutralizing (CRN) antibody against herpes simplex virus. Six of the cases, all from children under the age of 13 years, were unequivocally related to herpetic infection as evidenced by the presence of anti-herpes CRN antibody. During the same period, 144 other children who were normal healthy or suffering from unrelated non-febrile diseases were tested as controls; anti-herpes CRN antibody was not detected in any of them. Further, the age distribution of individuals with antibodies was compared between patients in the acute upper respiratory disease group and the control group. This analysis showed that approximately 5 to 7% of the acute upper respiratory diseases in the young children in this study would be attributed to herpetic infection.     

Patterns of on-shoot positioning of seed cones in relation to shoot length and position in the crowns of young Picea mariana

Summary Patterns of distribution of seed cones along the length and around the circumference of shoots were determined for young black spruce [Picea mariana (Mill.) B.S.P.] trees aged 9–17 years. Seed cone production averaged 5, 30, 62, 95, and 112 per tree of ages 9, 11, 13, 15, and 17 years, respectively. Cone distribution was restricted to distal and medial 1-year-old branches at age 9 and spread to distal 3-year-old branches by age 17. Sequentially, shoots of 0–25, 26–100, 101–250, 251–325, and 326–375 mm bore more cones in terminal, distal, medial, proximal, and basal positions along shoots, respectively. The uppermost and longest distal 1-year-old shoots bore most of their cones proximally and medially. On the shortest and innermost proximal order 2 shoots, cones were often terminal. The percentages of cones borne on upper, lower, and each of the two side surfaces of shoots were 31, 22, and 21, respectively, and 5% of the cones were terminal. Cones on lower surfaces were most common on the longest shoots near the apex of trees. Cones on upper surfaces became prevalent downward and outward in the crown. On-shoot positioning therefore varied in a predictable manner with shoot length, and thus with pattern of shoot-length distribution in the crown.     

旧石器和古人类遗址释光测年技术的可靠性和测年上限

释光测年技术已成为旧石器和古人类遗址,尤其是现代人类遗址,建立年代框架的重要工具之一。这一技术提供了现代人类出现在非洲、亚洲和澳大利亚的最早年代证据。本文简要介绍了释光测年的基本原理,对释光测年的可靠性和上限及所受的影响因素进行了综述。光释光测年的精密度(相对标准误差σ)一般为5%-10%,在理想条件下σ<5%,但是σ>10%的情况也不少见。与大量其他测年方法所获结果的一致性表明,光释光测年技术是可靠的。光释光测年的上限与样品的释光性质及环境剂量率有关,释光可靠年龄最大可达1百万年。对大多数遗址50万年的测年上限是可行的,这个年代范围涵盖了所有的现代人遗址。不同样品或颗粒间的释光性质差异很大,因而它们有不同的测年上限。同一样品中钾长石比石英有更高的测年上限,同一矿物中不同的释光信号对应的测年上限也不同。     

Continuing fertility transitions in a plural society: ethnic trends and differentials in Peninsular Malaysia

Fertility in Peninsular Malaysia has declined continuously from the late 1950s, reaching a total fertility rate of 3735 in 1983. All ethnic groups in Malaysia have contributed to this modern demographic transition but the rate of change has been most rapid for Chinese and Indians, Malay fertility having reached a plateau in the early 1980s. The effect of age structure, marital patterns and marital fertility (by parity) on the fertility declines for each ethnic community are analyzed. There has been a tendency, in each ethnic group, for the age distribution within the group of reproductive-age women to grow younger, reflecting the entry into the younger reproductive ages of the large birth cohorts of the 1950s and early 1960s. The effect of this on crude birth rates is hard to determine, because rising age at marriage and increasing use of contraception meant that fertility was increasingly concentrated in the more central reproductive ages. By the 1990s, the earlier declines in fertility will bring about a decline in the proportion of the total population made up of females in the main reproductive ages. After that point, further declines in fertility will be reflected in a sharper decline in the crude birth rate and hence the rate of population increase. Between 1947 and 1980, the age at marriage changed dramatically for females of all ethnic groups. The transition to higher age at marriage for Chinese was completed earlier, and since 1970 has risen by only a year. For Malays and Indians, the rise began later, proceeded faster and continued right up to 1980 when the medium ages at 1st marriage were Malays 22, Indians 23, Chinese 24 years. In 1980, Malay women on average were marrying 5 years later, and Indian women 6 years later than had their mothers' generation in 1947. The proportion never-married among Malay and Indian women aged 20-24 rose from 1/10 to 1/2 over this period; relatively greater changes are evident at ages 25-29. Other factors are the almost complete shift from parent-arranged to self-arranged marriages. Family size desired has decreased for all groups and the decline in breastfeeding has been offset by the sharp increase in the practice of contraception. Continuation of these trends would lead to replacement-level fertility for Malaysian Chinese and Indians by the year 2000. Malay fertility is likely to continue to decline but at a more moderate pace.     

Timing of fusion of the ischiopubic ramus from dry bone observations

There is little information about the age at which the ischiopubic ramus fuses derived from dry bone observations. This study documents the age ranges for union of the ischiopubic ramus in a sample of 148 known sex and age skeletons from Portugal, with ages ranging from birth to 20 years, using a three-stage scheme. The oldest female with an unfused ramus is 11 years old and the oldest male is 8 years old. The youngest male with a completely fused ramus is 7 years old, and the youngest female is 5 years old. Despite the relatively large sample size, partial fusion was a rare event to record as only two individuals were at this stage and these seemed relatively older than expected (12 and 14 years of age). The likely age interval for partial union of the ramus was subsequently estimated from logistic regression, for both sexes separated and combined. In the sex-pooled sample, the inter-quartile range (25th–75th percentile) for the median age of fusion is 7–11 years and the 10th–90th percentile range is 4–15 years. The scarcity of data on the age of ischiopubic fusion may be related to biases in the sample or to fusion occurring rapidly in this anatomical location. Additional studies may be required to assess the accuracy of the ages reported here, but at present this study provides the most comprehensive assessment of timing of fusion at the ischiopubic ramus from observations of dry bone specimens.     

Pediatric Continuous Reference Intervals of Serum Insulin-like Growth Factor 1 Levels in a Healthy Chinese Children Population – Based on PRINCE Study

ObjectivesWe aimed to establish age- and sex-dependent reference intervals for insulin-like growth factor 1 (IGF-1) based on the measurements of healthy Chinese children from the pediatric reference intervals in China study and to investigate whether body mass index (BMI) and height affect IGF-1 levels.MethodsA total of 3753 individuals with eligible blood specimens resampled from the pediatric reference intervals in China population were enrolled as reference individuals. IGF-1 levels were measured using a chemiluminescent immunoassay kit. The lower limit and upper limit values of the reference individuals were calculated by defining the 2.5th and 97.5th percentiles. The skewness-median-coefficient of variation method was used to calculate the standard deviation score (SDS) of serum IGF-1, and cubic spline curves were applied to depict a smoothed curve for each age- and sex-specific stratification of the L, M, and S parameters.ResultsSerum IGF-1 levels increased with age from the age of 1 year, peaking at around the age of 13 years in girls and 15 years in boys and then began to decline (both P <.001). Before 14 years, IGF-1 levels were higher in girls than in boys at the same age, and the difference was statistically significant (P < .05), but there was no significant difference in the IGF-1 levels between girls and boys aged 14 to 16 and 18 years. The Spearman correlation coefficients of height SDS, weight SDS, and BMI SDS with IGF-1 SDS were 0.29, 0.33, and 0.20, respectively (P < .001).ConclusionThis study established age- and sex-specific normative IGF-1 data for Chinese children and adolescents between the ages of 1 and 19 years. The BMI and height SDS had no effect on IGF-1 levels in healthy children.     

Anti-A and anti-B blood group antibody levels in relation to age in cynomolgus monkeys

Anti-A and anti-B blood group antibody levels were determined with serum samples of 583 cynomolgus monkeys of group-A and group-B, aged from 4 days to 15 years or more. Eight group-A infants free from anti-B antibody at ages of 4 to 25 days were consecutively followed up for the appearance of anti-B antibody. It appeared at ages between 68 and 160 days. Both anti-A and anti-B levels rose with increase in the age and reached a maximum at the age of 4 to 5 years. After that the levels gradually fell with aging.     

The interaction of the upper airway and thermo-metabolism on respiratory rhythm during non-REM sleep in the developing lamb.

This study investigates the role of metabolic rate and of vagal airway mechanisms in sustaining rhythmic breathing in the developing lamb. Fifteen lambs were prepared, at 2 days of age under fluothane anaesthesia, for sequential studies at 4, 14, 30, 45, and 55 days of age. At each age they were maintained at an ambient temperature of 5, 10, 15, 20, 25 and 30 degrees C for at least one hour before measurements were made during N-REM sleep. In 6 lambs at 4 days and in all lambs at older ages the upper airway was by-passed (by opening a tracheal window) for 10-15 minutes at each ambient temperature. Oxygen consumption was unaffected by upper airway by-pass and there were no consistent changes in mean breathing frequency or amplitude, with the exception of shifts to panting at warm ambient temperatures. Breathing pattern was unaffected by upper airway by-pass in lambs at 4 days of age, but at older ages loss of regularity of breathing frequently occurred (up to 47% of 30 days-old lambs at 25 degrees C). This was related to the fall in oxygen consumption with age and to basal values at thermoneutrality, and coincided with lower respiratory rates and increased use of expiratory laryngeal braking. Periodic breathing (and apnea) of a fixed cycle length (9.3 +/- 0.36 s) was a common feature (62%) of the observed breathing dysrhythmia. In young lambs high metabolic rate sustained high frequency rhythmic breathing which was unaffected by upper airway by-pass.(ABSTRACT TRUNCATED AT 250 WORDS)     

Age-dependent excretion of alanine aminopeptidase, alkaline phosphatase, gamma-glutamyltransferase and N-acetyl-beta-D-glucosaminidase in human urine

Urinary excretion of alanine aminopeptidase, alkaline phosphatase, gamma-glutamyltransferase and N-acetyl-beta-D-glucosaminidase was determined in gel-filtered samples of morning random urine specimens of 442 subjects of various ages (5 days to 58 years). Enzyme excretion related to urinary creatinine (enzyme/creatinine ratio; U/mmol creatinine) significantly decreased with increasing age. Sex-related differences of some enzyme excretions were found in age groups over 6 years. From these investigations, we calculated upper reference intervals (97.5 percentiles) for 5 age-dependent groups of children and adolescents and for one group of adults.     

The Life Course Dynamics of Affluence

Social science research finds that the only group to have experienced real economic gains over the past four decades is the top 20 percent of the income distribution. This finding, along with greater awareness of growing inequality, has renewed interest in mobility research that identifies how individuals and their progeny move into and out of upper versus lower income categories. In this study a new mobility methodology is proposed using life course concepts and life table statistical techniques. Panel data from a prospective national sample of the U.S. population age 25 to 60 are analyzed to estimate the extent of mobility associated with top percentiles in the income distribution. Empirical results suggest high mobility associated with top-level income. For example, 11 percent of the population is found to occupy the top one percentile for one or more years between the ages of 25 and 60. The study findings suggest that many experience short-term and/or intermittent mobility into top-level income, versus a smaller set that persist within top-level income over many consecutive years. Implications of the findings are discussed in terms of inequality buffering, opportunity versus insecurity, and the demographics of income inequality.     

Changes in cardiovascular disease risk factors from age 9 to 19 and the influence of television viewing

Objective:

The purpose of this study was to determine if time spent watching television is associated with changes in cardiovascular disease (CVD) risk factors from age 9 to 19.

Design and Methods:

Participants were girls enrolled in the NHLBI Growth and Health Study (n = 1,702), and CVD risk factors were measured at ages 10, 12, 14, 16, and 19. Longitudinal quantile regression was used to determine if television viewing was associated with changes in CVD risk factors over time at the 10th, 25th, 50th, 75th, and 90th percentiles of the CVD risk factors.

Results:

In black girls, television viewing (h/wk) was positively associated with sum of skinfolds (mm) at the 75th (0.22, 99% CI, 0.06‐0.38) and 90th percentiles (0.21, 99% CI, 0.05‐0.36), but not at the 10th, 25th, or 50th percentiles. In white girls, television viewing (h/wk) was positively associated with sum of skinfolds (mm) with the strength of the associations progressively stronger toward the upper tail of the skinfold distribution, adjusting for physical activity and other covariates (10th percentile: 0.08, 99% CI, 0.03‐0.13; 90th percentile: 0.42, 99% CI, 0.24‐0.59). All associations were adjusted for physical activity, dietary factors, sleep, and maturation. No associations were observed between television viewing and changes in systolic blood pressure, triglycerides, or cholesterol levels in black or white girls.

Conclusion:

Girls who spent more time watching television had greater increases in sum of skinfolds from age 9 to 19, independent of physical activity levels and other covariates. The associations observed were stronger at the upper tail of the skinfold distribution.