Final Height and Cardiometabolic Outcomes in Young Adults with Very Low Birth Weight (<1500 g)

Objective

Individuals with very low birth weight (VLBW; <1500 g) are known to be predisposed to both short final height and cardiometabolic disorders. However, associations between final height and cardiometabolic outcomes including glucose metabolism in VLBW individuals in young adulthood are not fully investigated.

Methods

We investigated glucose metabolism and other cardiometabolic outcomes such as lipid profiles, blood pressure, renal function, urinary albumin, and thyroid function in young adults with VLBW born between 1980 and 1990. Short stature was defined as a final height <10th percentile. Glucose intolerance [diabetes, impaired glucose tolerance (IGT), and impaired fasting glucose (IFG)] was determined using 75-g oral glucose tolerance tests. Associations between final height and cardiometabolic outcomes were examined using logistic or multiple linear regression.

Results

A total of 628 VLBW individuals were screened and 111 young adults with VLBW (19–30 years) participated in the study. Of the participants, 40 subjects (36%) had short stature with a final height <10th percentile. Eight subjects (7.2%) had glucose intolerance (1, diabetes; 6, IGT; 1, IFG). Short stature was correlated with glucose intolerance (odds ratio 11.1; 95% CI 1.92, 99.7; P = 0.006). Final height was inversely associated with the homeostatic model assessment (HOMA) of insulin resistance, HOMA-β, insulinogenic index, and total/LDL-cholesterol. The associations of final height with insulin sensitivity and lipid profiles remained after adjustment for target height and age at puberty onset.

Conclusions

Shorter final height was associated with less favorable metabolic profiles in young adults with VLBW, and may be partly mediated by reduced insulin sensitivity. These associations were independent of target height or age at puberty onset.     

Postural Sway and Gaze Can Track the Complex Motion of a Visual Target

Variability is an inherent and important feature of human movement. This variability has form exhibiting a chaotic structure. Visual feedback training using regular predictive visual target motions does not take into account this essential characteristic of the human movement, and may result in task specific learning and loss of visuo-motor adaptability. In this study, we asked how well healthy young adults can track visual target cues of varying degree of complexity during whole-body swaying in the Anterior-Posterior (AP) and Medio-Lateral (ML) direction. Participants were asked to track three visual target motions: a complex (Lorenz attractor), a noise (brown) and a periodic (sine) moving target while receiving online visual feedback about their performance. Postural sway, gaze and target motion were synchronously recorded and the degree of force-target and gaze-target coupling was quantified using spectral coherence and Cross-Approximate entropy. Analysis revealed that both force-target and gaze-target coupling was sensitive to the complexity of the visual stimuli motions. Postural sway showed a higher degree of coherence with the Lorenz attractor than the brown noise or sinusoidal stimulus motion. Similarly, gaze was more synchronous with the Lorenz attractor than the brown noise and sinusoidal stimulus motion. These results were similar regardless of whether tracking was performed in the AP or ML direction. Based on the theoretical model of optimal movement variability tracking of a complex signal may provide a better stimulus to improve visuo-motor adaptation and learning in postural control.     

Relationship between Spectral Characteristics of Spontaneous Postural Sway and Motion Sickness Susceptibility

Motion sickness (MS) usually occurs for a narrow band of frequencies of the imposed oscillation. It happens that this frequency band is close to that which are spontaneously produced by postural sway during natural stance. This study examined the relationship between reported susceptibility to motion sickness and postural control. The hypothesis is that the level of MS can be inferred from the shape of the Power Spectral Density (PSD) profile of spontaneous sway, as measured by the displacement of the center of mass during stationary, upright stance. In Experiment 1, postural fluctuations while standing quietly were related to MS history for inertial motion. In Experiment 2, postural stability measures registered before the onset of a visual roll movement were related to MS symptoms following the visual stimulation. Study of spectral characteristics in postural control showed differences in the distribution of energy along the power spectrum of the antero-posterior sway signal. Participants with MS history provoked by exposure to inertial motion showed a stronger contribution of the high frequency components of the sway signal. When MS was visually triggered, sick participants showed more postural sway in the low frequency range. The results suggest that subject-specific PSD details may be a predictor of the MS level. Furthermore, the analysis of the sway frequency spectrum provided insight into the intersubject differences in the use of postural control subsystems. The relationship observed between MS susceptibility and spontaneous posture is discussed in terms of postural sensory weighting and in relation to the nature of the provocative stimulus.     

Isolation of Clostridium difficile from the Feces and the Antibody in Sera of Young and Elderly Adults

Attempts were made to isolate Clostridium difficile from a total of 431 fecal specimens from 149 young and 213 elderly healthy adults, and 69 elderly adults with cerebrovascular disease but no gastrointestinal disease. C. difficile was isolated from 49 specimens, and the frequency of isolation was 15.4% in healthy young adults, 7.0% in healthy elderly adults, and 15.9% in elderly adults with cerebrovascular disease. Thirty-four (about 70%) of the 49 C. difficile strains isolated produced cytotoxin which was neutralized by Clostridium sordellii antitoxin in vitro; in both young and elderly adults approximately 30% of the C. difficile isolates were nontoxigenic. The mean concentration of C. difficile in feces was 10^4.1/g in young adults and 10^4.6/g in elderly adults, with a range of 10^2.0 to 10^6.9/g. Antibody against C. difficile toxin was found in most of the sera obtained from young adults carrying toxigenic C. difficile, but not in sera of elderly adults, no matter how abundant was toxigenic C. difficile in the feces.     

Effect of Bisphosphonates on Fracture Incidence in Young Adults With Low Bone Density

ObjectiveTo assess the effect of bisphosphonates on fracture incidence in young adults over a 5-year follow-up period.MethodsBased on the Kaiser Permanente electronic health record, this retrospective study investigated patients aged 19 to 40 years with abnormal bone density (either any Z-score of ≤−2 standard deviation [SD] or any T-score of ≤−2.5 SD). The incidence and time to fracture between the control (patients with <6 months of bisphosphonate exposure) and treatment (patients with ≥6 months of bisphosphonate use within 4 years of their first dual energy x-ray absorptiometry scan) groups were compared. Comparisons were analyzed with Χ² test for categorical variables and Wilcoxon rank sum test for continuous variables.ResultsA total of 422 patients met the inclusion and exclusion criteria. Fractures occurred in 18 patients (5.0%) of the control group (n = 358) and 5 patients (7.8%) of the treatment group (n = 64; P = .37). T-scores were significantly lower in the treatment group (−2.53 ± 0.58 SD) than those in the control group (−2.30 ± 0.80 SD; P = .002) but did not correlate with fracture risk. No significant differences were found in total fracture incidence (hazard ratio = 1.54; 95% confidence interval, 0.26-6.26). Similarly, no correlation was noted between the length of bisphosphonate therapy and fracture incidence (odds ratio = 0.99; 95% confidence interval, 0.966-1.026).ConclusionIn summary, we did not find a clear correlation of fracture incidence with the use of bisphosphonates in young adults. Further research into the pathophysiology, specific etiologies, and treatment options in this population is needed.     

The Elaboration of Associations in Very Young Children

Iu. K. Panferov was the first to make an attempt to provide a physiological analysis of the formation of a temporary connection between a number of indifferent stimuli in school-age children (9). G.P. Zelenyi and P. A. Prokof'ev (4) published analogous studies with adult subjects.     

Difference in Postural Control during Quiet Standing between Young Children and Adults: Assessment with Center of Mass Acceleration

The development of upright postural control has often been investigated using time series of center of foot pressure (COP), which is proportional to the ankle joint torque (i.e., the motor output of a single joint). However, the center of body mass acceleration (COM_acc), which can reflect joint motions throughout the body as well as multi-joint coordination, is useful for the assessment of the postural control strategy at the whole-body level. The purpose of the present study was to investigate children’s postural control during quiet standing by using the COM_acc. Ten healthy children and 15 healthy young adults were instructed to stand upright quietly on a force platform with their eyes open or closed. The COM_acc as well as the COP in the anterior–posterior direction was obtained from ground reaction force measurement. We found that both the COM_acc and COP could clearly distinguish the difference between age groups and visual conditions. We also found that the sway frequency of COM_acc in children was higher than that in adults, for which differences in biomechanical and/or neural factors between age groups may be responsible. Our results imply that the COM_acc can be an alternative force platform measure for assessing developmental changes in upright postural control.     

The Influence of Postural Changes on the Glomerular Filtration Rate in Nephroptosis

The influence of postural changes on renal function was determined in 13 patients with nephroptosis and in 5 normal subjects by measuring GFR in the erect and supine positions. The results indicate that GFR was reduced in the erect position in 10 of 13 patients with either unilateral or bilateral nephroptosis whereas GFR was increased in the erect position in 4 of 5 patients without renal disease. One patient with bilateral nephroptosis and renovascular hypertension was studied before and after surgical correction of his disease. These observations indicate that patients with nephroptosis may have significant reductions in renal function when they assume an upright position, and suggest that GFR measurements in the supine and erect position in patients with nephroptosis can be helpful in evaluating this disease.     

The Carbohydrate Resources of Young Apple-trees under Four Levels of Illumination

Young apple-trees were grown in four light intensities to assessthe differentia dependence of growth on reserve carbohydratesand current products of photosynthesis. Low light intensitycaused no greater depletion of reserve carbohydrates duringinitial growth in spring, and during the growing season a similarcomposition was maintained with all treatments despite largedifferences in dry-weight increment. The results suggest thatthere is an ‘integrated phase of growth’ duringwhich carbohydrate composition is independent of external factors,and which may be followed by a ‘labile phase’ duringwhich accumulation of reserves can be influenced.     

Influence of Chronotype,Season, and Sex of Subject on Sleep Behavior of Young Adults

The aim of this study was to investigate whether sex, season, and/or chronotype influence the sleep behavior of university students. Detailed data were collected on activity/rest patterns by wrist actigraphy combined with diaries. Thirty‐four medical students (19 female and 15 male) were monitored by Actiwatch® actometers for 15 consecutive days in May and again in November. The data of a modified Horne and Östberg chronotype questionnaire, which were collected from 1573 female and 1124 male medical school students surveyed in the spring and autumn over an eight‐year period, were evaluated. Actiwatch® sleep analysis software was used to process the activity data with statistical analyses performed with ANOVA. We found no significant sex‐specific differences in sleep efficiency, sleep onset latency, or actual sleep‐time duration. However, we did find a difference in sleep efficiency between morning and evening types, with morning types having a higher sleep efficiency (87.9%, SD=1.3) than evening types (84.3%, SD=0.87%; p=0.007). Seasonal differences were also detected: the actual sleep‐time duration in autumn was significantly longer (mean 6.9 h, SD=0.13 h) than in spring (6.6 h, SD=0.1 h; p=0.013). Evaluation of the chronotype questionnaire data showed that individuals with no special preference for morningness or eveningness (i.e., so‐called intermediates) were most common. The distribution of chronotypes was related to the sex of subject. Men displayed eveningness significantly more often than women (28.9% males vs. 20.8% females; p<0.001), while females exhibited greater morningness (20.3% females vs.15.6% males; p<0.001). Sex influences chronotype distribution, but not actual sleep time‐duration, sleep onset latency, or sleep efficiency. The latter, however, differed among chronotypes, while actual sleep‐time duration was affected by season.     

Impulsive Social Influence Increases Impulsive Choices on a Temporal Discounting Task in Young Adults

Adolescents and young adults who affiliate with friends who engage in impulsive behavior are more likely to engage in impulsive behaviors themselves, and those who associate with prosocial (i.e. more prudent, future oriented) peers are more likely to engage in prosocial behavior. However, it is difficult to disentangle the contribution of peer influence vs. peer selection (i.e., whether individuals choose friends with similar traits) when interpreting social behaviors. In this study, we combined a novel social manipulation with a well-validated delay discounting task assessing impulsive behavior to create a social influence delay discounting task, in which participants were exposed to both impulsive (smaller, sooner or SS payment) and non-impulsive (larger, later or LL payment) choices from their peers. Young adults in this sample, n = 51, aged 18–25 had a higher rate of SS choices after exposure to impulsive peer influence than after exposure to non-impulsive peer influence. Interestingly, in highly susceptible individuals, the rate of non-impulsive choices did not increase after exposure to non-impulsive influence. There was a positive correlation between self-reported suggestibility and degree of peer influence on SS choices. These results suggest that, in young adults, SS choices appear to be influenced by the choices of same-aged peers, especially for individuals who are highly susceptible to influence.     

重症肺炎影响极低出生体重儿血小板及凝血功能的研究

目的:通过观察我院收治的极低出生体重新生儿肺炎的临床治疗,研究重症肺炎对该类疾病患儿的血小板及凝血功能的影响,探讨其临床研究价值.方法:将47例一般肺炎的极低出生体重新生儿设为对照组,45例重症肺炎的极低出生体重新生儿设为实验组,对比分析两组患儿的血小板参数的检测指标并行患儿凝血功能检查.结果:在血小板参数方面,实验组在MPV和PDW的数据较对照组高,而在PLT明显较低;在凝血功能方面,实验组在PT、APTT和TT等方面的数据较对照组高,而在FIB方面明显较低.结论:临床上对动态监测重症肺炎患儿血小板的变化情况,对判断该疾病患儿的预后具有积极的参考与预警意义,而对重症肺炎患儿出现凝血系统功能紊乱及时把握具体发病机制,对症进行凝血功能恢复治疗,值得临床进一步研究与探讨.     

Comparison of Compositions and Metabolic Activities of Fecal Microbiotas in Young Adults and in Antibiotic-Treated and Non-Antibiotic-Treated Elderly Subjects

The colonic microbiota mediates many cellular and molecular events in the host that are important to health. These processes can be affected in the elderly, because in some individuals, the composition and metabolic activities of the microbiota change with age. Detailed characterizations of the major groups of fecal bacteria in healthy young adults, in healthy elderly people, and in hospitalized elderly patients receiving antibiotics were made in this study, together with measurements of their metabolic activities, by analysis of fecal organic acid and ammonia concentrations. The results showed that total anaerobe numbers remained relatively constant in old people; however, individual bacterial genera changed markedly with age. Reductions in numbers of bacteroides and bifidobacteria in both elderly groups were accompanied by reduced species diversity. Bifidobacterial populations in particular showed marked variations in the dominant species, with Bifidobacterium angulatum and Bifidobacterium adolescentis being frequently isolated from the elderly and Bifidobacterium longum, Bifidobacterium catenulatum, Bifidobacterium boum, and Bifidobacterium infantis being detected only from the healthy young volunteers. Reductions in amylolytic activities of bacterial isolates in healthy elderly subjects and reduced short-chain fatty acid concentrations supported these findings, since bifidobacteria and bacteroides are important saccharolytic groups in the colon. Conversely, higher numbers of proteolytic bacteria were observed with feces samples from the antibiotic-treated elderly group, which were also associated with increased proteolytic species diversity (fusobacteria, clostridia, and propionibacteria). Other differences in the intestinal ecosystem in elderly subjects were observed, with alterations in the dominant clostridial species in combination with greater numbers of facultative anaerobes.     

Antibody Persistence and Booster Responses to Split-Virion H5N1 Avian Influenza Vaccine in Young and Elderly Adults

Avian influenza continues to circulate and remains a global health threat not least because of the associated high mortality. In this study antibody persistence, booster vaccine response and cross-clade immune response between two influenza A(H5N1) vaccines were compared. Participants aged over 18-years who had previously been immunized with a clade 1, A/Vietnam vaccine were re-immunized at 6-months with 7.5 μg of the homologous strain or at 22-months with a clade 2, alum-adjuvanted, A/Indonesia vaccine. Blood sampled at 6, 15 and 22-months after the primary course was used to assess antibody persistence. Antibody concentrations 6-months after primary immunisation with either A/Vietnam vaccine 30 μg alum-adjuvanted vaccine or 7.5 μg dose vaccine were lower than 21-days after the primary course and waned further with time. Re-immunization with the clade 2, 30 μg alum-adjuvanted vaccine confirmed cross-clade reactogenicity. Antibody cross-reactivity between A(H5N1) clades suggests that in principle a prime-boost vaccination strategy may provide both early protection at the start of a pandemic and improved antibody responses to specific vaccination once available.Trial Registration: ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00415129","term_id":"NCT00415129"}}NCT00415129     

The Influence of Dark Adaptation Temperature on the Reappearance of Variable Fluorescence following Illumination

The effect of chilling temperatures (5°C) on chlorophyll fluorescence transients was used to study chilling-induced inhibition of photosynthesis in plant species with differing chilling sensitivities. A Brancker SF-20 fluorometer was used to measure induced fluorescence transients from both attached and detached leaves of chilling-sensitive cucumber (Cucumis sativus L. cv Ashley) and chilling-resistant pea (Pisum sativum L. cv Alaska). The rate of reappearance of the variable component of fluorescence (F_v), following a period of illumination at 25°C, was dependent on the temperature at which the leaf was allowed to dark adapt in chilling-sensitive cucumber, but not in chilling-resistant pea. In cucumber, dark adaptation at 25°C following illumination resulted in a much faster return of F_v than dark adaptation at 5°C following illumination. However, F_v reappearance during the dark adaptation period in chilling-resistant pea was temperature independent. The difference in the temperature response of F_v following illumination correlated with temperature sensitivity of these two species. The process responsible for the difference in F_v may represent a site of chilling sensitivity in the photosynthetic apparatus.     

Influence of Stretching Training of the Lower Limbs on Postural Stability

Human Physiology - The paper investigates the effects of stretching training on stabilographic and kinematic parameters of one-legged posture stability in healthy girls (n = 14). Stretching...