BACKGROUND & AIMS: :The purpose of this study was to identify distinct trajectories of smoking behavior during a period extending from adolescence (mean age = 14 years) to young adulthood (mean age = 26 years) among African American and Puerto Rican adolescents/young adults, to examine ethnic and gender differences in group membership, and to assess the ability of peer and parental smoking to distinguish among trajectory groups. A community-based sample of 451 African American and Puerto Rican adolescents was interviewed four times during adolescence and in early adulthood, covering a span of 12 years. For both ethnic/racial groups, four distinct trajectories were identified: Nonsmokers, maturing-out smokers, late-starting smokers, and early-starting continuous smokers. Compared with Puerto Ricans, African Americans were over-represented in the nonsmoking group, whereas Puerto Ricans were over-represented in the early-starting continuous group. Females were more likely than males to be early-starting continuous smokers than late starters. Adolescents who were exposed to peer and parental smoking in early adolescence were more likely to belong to trajectory groups characterized by higher levels of smoking. These findings show that exposure to peer and parental smoking in early adolescence constitutes a risk factor for engaging in elevated levels of smoking behavior at an early age and for continued smoking into adulthood for urban African Americans and Puerto Ricans. To be most effective, smoking prevention programs should address peer group and family influences on adolescent smoking.

背景与目标： : 这项研究的目的是确定从青春期 (平均年龄 = 14岁) 到成年青年 (平均年龄 = 26岁) 的一段时期内，非洲裔美国人和波多黎各青少年/年轻人的吸烟行为的不同轨迹，以检查种族和性别在群体成员中的差异，并评估同伴和父母吸烟区分轨迹组的能力。在青春期和成年初期，对451名非洲裔美国人和波多黎各青少年的社区样本进行了四次采访，涵盖了12年。对于两个种族/种族群体，都确定了四个不同的轨迹: 不吸烟者，成熟吸烟者，较晚开始吸烟者和早期开始连续吸烟者。与波多黎各人相比，非裔美国人在不吸烟组中的比例过高，而在开始的连续组中，波多黎各人的比例过高。女性比男性更有可能是早起的连续吸烟者，而不是早起的吸烟者。青春期早期暴露于同伴和父母吸烟的青少年更有可能属于吸烟水平较高的轨迹组。这些发现表明，青春期早期暴露于同伴和父母吸烟是城市非裔美国人和波多黎各人早期吸烟行为水平升高以及成年后继续吸烟的危险因素。为了最有效，预防吸烟计划应解决同伴群体和家庭对青少年吸烟的影响。

BACKGROUND & AIMS: OBJECTIVE:To study the temporal relationships between cytomegalovirus (CMV) viral load and specific UL97 mutations in polymorphonuclear leukocytes (PMNL) and plasma samples from a patient with AIDS who developed ganciclovir-resistant CMV retinitis.

METHODS:Sequential PMNL and plasma samples were analysed for determination of the CMV viral load using non-molecular methods and a quantitative polymerase chain reaction (PCR) assay. Screening of the same samples for the most common mutations conferring ganciclovir resistance was performed using nested PCR and restriction enzyme analysis.

RESULTS:At the time of progression of CMV retinitis (after 6 months of ganciclovir), a rapid increase in the CMV DNA load was found in both PMNL and plasma samples. This increase paralleled the emergence of a specific mutation (V594) in the same samples and recovery of ganciclovir-resistant blood isolates. In this patient, however, the only tests that substantially predicted the progression of CMV disease were the quantitative PCR assay using PMNL and to a lesser extent the pp65 antigenemia assay.

CONCLUSIONS:Quantitative evaluation of the CMV viral load in PMNL using sensitive assays such as PCR appears to be a promising approach for monitoring antiviral therapy in subjects with AIDS. In addition, common mutations conferring ganciclovir resistance can be detected directly in PMNL and plasma samples.

背景与目标： 目标 : 研究巨细胞病毒 (CMV) 病毒载量与多形核白细胞 (PMNL) 和血浆样本中特定UL97突变之间的时间关系，该患者患有更昔洛韦耐药的CMV视网膜炎。
方法 : 使用非分子方法和定量聚合酶链反应 (PCR) 分析方法分析了连续的PMNL和血浆样品，以确定CMV病毒载量。使用巢式PCR和限制性内切酶分析对相同样品进行了更昔洛韦抗性最常见突变的筛选。
结果 : 在CMV视网膜炎进展时 (更昔洛韦6个月后)，在PMNL和血浆样品中发现CMV DNA载量迅速增加。这种增加与同一样品中出现特定突变 (V594) 和更昔洛韦耐药血液分离株的回收平行。但是，在该患者中，唯一可以基本预测CMV疾病进展的测试是使用PMNL的定量PCR测定，以及在较小程度上使用pp65抗原血症测定。
结论 : 使用敏感的检测方法 (例如PCR) 定量评估PMNL中的CMV病毒载量似乎是监测艾滋病患者抗病毒治疗的有希望的方法。此外，可以直接在PMNL和血浆样品中检测到赋予更昔洛韦抗性的常见突变。

BACKGROUND & AIMS: :Carbon monoxide (CO) poisoning may result in focal and diffuse neuropathological changes, including basal ganglia lesions. The effect of CO poisoning on basal ganglia volumes over time is unclear. We assessed basal ganglia volumes longitudinally following CO poisoning. We prospectively enrolled 73 CO poisoned patients who underwent brain MR imaging on day 1 (baseline), 2 weeks, and 6 months post-CO poisoning. Basal ganglia volumes were obtained. One patient had bilateral globus pallidus lesions at two weeks and 6 months. Of the CO-poisoned patients 28% had volume reduction in at least one basal ganglia structure by 6 months, of which 21% had putamen, 15% had caudate, 15% had globus pallidus, and 16% had total basal ganglia volume reduction. Putamen volumes were significantly smaller from baseline to six months (p = 0.02). Verbal memory and mental processing speed correlated with smaller putamen and globus pallidus volumes. Carbon monoxide poisoning results in basal ganglia volume reduction 6 months post CO poisoning. Slow mental processing speed and impaired memory correlated with smaller putamen and globus pallidus volumes. Clinicians need to be aware of basal ganglia neuropathologic changes in the absence of observable lesions following CO poisoning.

背景与目标： 一氧化碳 (CO) 中毒可能导致局灶性和弥漫性神经病理变化，包括基底节病变。CO中毒对基底神经节体积随时间的影响尚不清楚。我们在CO中毒后纵向评估了基底神经节的体积。我们前瞻性地招募了73名CO中毒患者，他们在CO中毒后第1天 (基线)，2周和6个月接受了脑MR成像。获得基底神经节体积。一名患者在两周和6个月时出现双侧苍白球病变。在共中毒的患者中，28% 在6个月前至少有一个基底神经节结构的体积减少，其中21% 有壳核，15% 有尾状核，15% 有苍白球，16% 有总基底神经节体积减少。从基线到6个月，壳核体积明显较小 (p = 0.02)。言语记忆和心理处理速度与较小的壳核和苍白球体积相关。一氧化碳中毒导致CO中毒后6个月基底神经节体积减少。缓慢的心理处理速度和记忆受损与较小的壳核和苍白球体积有关。在CO中毒后没有可观察到的病变的情况下，临床医生需要意识到基底神经节的神经病理学变化。

BACKGROUND & AIMS: BACKGROUND:Trabecular bone strength diminishes as a result of osteoporosis and altered biomechanical loading at the vertebral and spinal levels. The spine consists of the anterior, middle and posterior columns and the load supported by the anterior and middle columns will differ across different regions of the spine. Stress shielding of the anterior column can contribute to bone loss and increase the risk of wedge fracture. There is a lack of quantitative data related to regional spinal bone mineral density distribution over time. We hypothesize that there is an increase in the posterior-to-anterior vertebral body bone mineral density ratio and a decrease in whole-body bone mineral density over time. METHODS:Bone mineral density was measured in 33 subjects using quantitative computed tomography scans for L1-L3 vertebrae, region (anterior and posterior vertebral body), and time (baseline and 6 years after). FINDINGS:Lumbar bone mineral density decreased significantly (Δ: ~15%) from baseline to the 6th year visit. Individual vertebra differences over time (L1: ~14%, L2: ~14%, L3: ~17%) showed statistical significance. Anterior bone mineral density change was significantly greater than in the posterior vertebral body region (Δ anterior: ~18%; Δ posterior: ~13%). Posterior-to-anterior bone mineral density ratio was significantly greater in the 6th year compared to baseline values (mean (SD), 1.33 (0.2) vs. 1.23 (0.1)). INTERPRETATION:This study provides longitudinal quantitative measurement of bone mineral density in vertebrae as well as regional changes in the anterior and posterior regions. Understanding bone mineral density distribution over time may help to decrease the risk of wedge fractures if interventions can be developed to bring spine loading to its normal state.

背景与目标：

BACKGROUND & AIMS: :We investigated the ability of systolic and diastolic carotid artery longitudinal wall motion (CALM) to delineate expected differences in arterial health in individuals representing a range of both age and health status. We recruited 161 younger healthy adults (aged 24 ± 5 y), 51 older healthy adults (aged 70 ± 5 y) and 14 adults with coronary artery disease (aged 67 ± 8 y) for resting assessment of CALM and arterial stiffness. All CALM parameters were reduced in the old healthy adults and adults with coronary artery disease compared with the young healthy adults (p < 0.01), with diastolic velocity and maximum diastolic acceleration being further reduced in the adults with coronary artery disease than in the older healthy adults (p < 0.01). Diastolic CALM parameters were more strongly related to age (β range: -0.46 to -0.53) than systolic CALM parameters (β range: -0.24 to -0.44). In contrast to previous examinations of a variety of CALM parameters, diastolic CALM may provide superior promise in terms of characterizing arterial wall properties, with additional sensitivity to cardiovascular disease status.

背景与目标： : 我们研究了收缩期和舒张期颈动脉纵向壁运动 (CALM) 描绘代表年龄和健康状况范围的个体的动脉健康预期差异的能力。我们招募了161名年轻的健康成年人 (24 ± 5岁)，51名老年健康成年人 (70 ± 5岁) 和14名患有冠状动脉疾病的成年人 (67 ± 8岁) 进行静息评估平静和动脉僵硬度。与年轻健康成年人相比，老年健康成年人和患有冠状动脉疾病的成年人的所有CALM参数均降低 (p <0.01)，与老年健康成年人相比，患有冠状动脉疾病的成年人的舒张速度和最大舒张加速度进一步降低 (p <0.01)。舒张期平静参数与年龄 (β 范围: -0.46至-0.53) 的相关性高于收缩期平静参数 (β 范围: -0.24至-0.44)。与以前对各种平静参数的检查相比，舒张期平静在表征动脉壁特性方面可能具有出色的前景，并且对心血管疾病状态具有额外的敏感性。

BACKGROUND & AIMS: OBJECTIVE:To investigate: (1) the course of coronary heart disease risk factors (lipid profiles and body mass index (BMI)) in the first five years after discharge from inpatient spinal cord injury (SCI) rehabilitation and (2) the association between lifestyle (physical activity, self-care related to fitness, smoking, alcohol, body mass and low-fat diet) and coronary heart disease risk factors during that period. DESIGN:Prospective cohort study. PARTICIPANTS/METHODS:Individuals with SCI (N=130). Total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG) and BMI were determined at discharge from inpatient rehabilitation and 1 and 5 years after discharge. Using multilevel regression models, the effects of lifestyle (drinking alcohol, smoking, active lifestyle and self-care) on the lipid profiles and BMI were determined. RESULTS:After correction for lesion and personal characteristics, no changes in lipid profiles in the five years after discharge were seen, whereas the BMI increased significantly with 1.8 kg m(-2). A high percentage was at risk of cardiovascular disease due to high BMI (63-75%) or HDL (66-95%). The individuals who indicated to maintain their fitness level as good as possible and the individuals with a low BMI showed better lipid profiles. Individuals with a more active lifestyle showed higher HDL levels. Individuals who avoid smoking showed a 1.5 kg m(-2) higher BMI. CONCLUSION:Lipid profiles seem to stabilize in the years after discharge from inpatient SCI rehabilitation, whereas the BMI increased. Lifestyle factors associated with a favorable lipid profile and BMI could be identified.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:To examine the relative contribution of hyperactivity, conduct, and emotional problems in predicting criminal offending. METHOD:In all, 173 boys aged 6 to 8 years (assessed for hyperactivity, conduct, and emotional problems) were followed up 19 years later by examining criminal offense histories. RESULTS:Significant main effects for total and violent convictions were found, the strongest being for violent criminal offenses. Conduct problems predicted general offending (irrespective of the type of conviction), whereas emotional problems were the single best predictor of violent convictions. Hyperactivity was not a significant predictor in the models. CONCLUSION:The findings provide insight into the developmental mechanisms that mediate criminal behavior by showing that childhood emotional problems independently contribute to the risk of violent offending in later life.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:Acute stress reactions (ASR) and postpartum depressive symptoms (PDS) are frequent after childbirth. The present study addresses the change and overlap of ASR and PDS from the 1- to 3-week postpartum and examines the interplay of caregiver support and subjective birth experience with regard to the development of ASR/PDS within a longitudinal path model. METHOD:A total of 219 mothers completed questionnaires about caregiver support and subjective birth experience (Salmon's Item List) at 48-6-h postpartum. ASR and PDS were measured for 1- and 3-week postpartum. The Impact of Event Scale (IES) was used to assess ASR, and the Edinburgh Postnatal Depression Scale (EPDS) was used to assess PDS. RESULTS:ASR was frequent 1-week postpartum (44.7%) and declined till week 3 (24.8%, p <.001), while the prevalence of PDS was continuous (14.2% week 1; 12.6% week 3; p = .380). Favorable reports of caregiver support were related to better subjective childbirth experience, which was related to lower ASR and PDS (controlled for age, mode of delivery, parity, EDA and duration of childbirth). CONCLUSION:High quality of intrapartum care and positive birth experiences facilitate psychological adjustment in the first 3-week postpartum.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:Predicted maturity offset and age at peak height velocity are increasingly used with youth athletes, although validation studies of the equations indicated major limitations. The equations have since been modified and simplified. OBJECTIVE:The objective of this study was to validate the new maturity offset prediction equations in independent longitudinal samples of boys and girls. METHODS:Two new equations for boys with chronological age and sitting height and chronological age and stature as predictors, and one equation for girls with chronological age and stature as predictors were evaluated in serial data from the Wrocław Growth Study, 193 boys (aged 8-18 years) and 198 girls (aged 8-16 years). Observed age at peak height velocity for each youth was estimated with the Preece-Baines Model 1. The original prediction equations were included for comparison. Predicted age at peak height velocity was the difference between chronological age at prediction and maturity offset. RESULTS:Predicted ages at peak height velocity with the new equations approximated observed ages at peak height velocity in average maturing boys near the time of peak height velocity; a corresponding window for average maturing girls was not apparent. Compared with observed age at peak height velocity, predicted ages at peak height velocity with the new and original equations were consistently later in early maturing youth and earlier in late maturing youth of both sexes. Predicted ages at peak height velocity with the new equations had reduced variation compared with the original equations and especially observed ages at peak height velocity. Intra-individual variation in predicted ages at peak height velocity with all equations was considerable. CONCLUSION:The new equations are useful for average maturing boys close to the time of peak height velocity; there does not appear to be a clear window for average maturing girls. The new and original equations have major limitations with early and late maturing boys and girls.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:Older people constitute a significant proportion of the total population and their number is projected to increase by more than half by 2030. This increasing probability of late survival comes with considerable individual, economic and social impact. Physical activity (PA) can influence the ageing process but the specific relationship with healthy ageing (HA) is unclear. METHODS:We conducted a systematic review and meta-analysis of longitudinal studies examining the associations of PA with HA. Studies were identified from a systematic search across major electronic databases from inception as January 2017. Random-effect meta-analysis was performed to calculate a pooled effect size (ES) and 95% CIs. Studies were assessed for methodological quality. RESULTS:Overall, 23 studies were identified including 174,114 participants (30% men) with age ranges from 20 to 87 years old. There was considerable heterogeneity in the definition and measurement of HA and PA. Most of the identified studies reported a significant positive association of PA with HA, six reported a non-significant. Meta-analysis revealed that PA is positively associated with HA (ES: 1.39, 95% CI=1.23-1.57, n=17) even if adjusted for publication bias (ES: 1.27, 95% CI=1.11-1.45, n=20). CONCLUSIONS:There is consistent evidence from longitudinal observational studies that PA is positively associated with HA, regardless of definition and measurement. Future research should focus on the implementation of a single metric of HA, on the use of objective measures for PA assessment and on a full-range of confounding adjustment. In addition, our research indicated the limited research on ageing in low-and-middle income countries.

背景与目标：

BACKGROUND & AIMS: OBJECTIVES:To examine the mental health of unaccompanied refugee minors prospectively during the asylum-seeking process, with a focus on specific stages in the asylum process, such as age assessment, placement in a supportive or non-supportive facility and final decision on the asylum applications. DESIGN:This was a2½ year follow-up study of unaccompanied minors (UM) seeking asylum in Norway. Data were collected within three weeks (n=138) and at 4 months (n=101), 15 months (n=84) and 26 months (n=69) after arrival. SETTING:Initially in an observation and orientation centre for unaccompanied asylum-seeking adolescents, and subsequently wherever the UM were located in other refugee facilities in Norway. PARTICIPANTS:Male UM from Afghanistan, Somalia, Algeria and Iran. MAIN OUTCOME MEASURES:Mental health symptoms assessed by Hopkins Symptom Checklist-25 and Harvard Trauma Questionnaire. RESULTS:At the group level, the young asylum seekers reported high levels of psychological distress on arrival and symptom levels that stayed relatively unchanged over time. According to age-assessment procedures, 56% of the population were not recognised as minors. Subsequent placement in a low-support facility was associated with higher levels of psychological distress in the follow-up period. Those who were placed in a reception centre for adults had higher levels of psychological distress symptoms both after 15 months and 26 months compared with the remaining participants who were placed in reception centres for youth. Refusal of asylum was highly associated with higher levels of psychological distress. CONCLUSION:Mental health trajectory of young asylum seekers appears to be negatively affected by low support and refusal of asylum.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:We determined the longitudinal association of glucose metabolism with retinopathy in a sample of the Australian population. RESEARCH DESIGN AND METHODS:The Australian Diabetes Obesity and Lifestyle (AusDiab) study is a national, longitudinal study of adults aged > or =25 years from 42 randomly selected areas of Australia. Retinopathy was assessed at baseline in 1999-2000 and 5 years later in 2004-2005 in participants identified as having diabetes (based on self-report and oral glucose tolerance test) and impaired glucose metabolism and in a random sample with normal glucose tolerance. Complete retinal data were available for 1,192 participants. Photographs were graded at two time points according to a simplified version of the Wisconsin grading system. RESULTS:The 5-year incidences of retinopathy were 13.9 and 3.0% among those with known and newly diagnosed diabetes at baseline, respectively. Of those who developed incident newly diagnosed diabetes at follow-up, 11.9% had retinopathy at baseline compared with 5.6% of those who did not progress to incident newly diagnosed diabetes (P = 0.037). After adjustment for factors identified as risk factors for diabetes, individuals with retinopathy signs at baseline were twice as likely to develop incident newly diagnosed diabetes compared with those who did not have retinopathy signs at baseline. CONCLUSIONS:The 5-year incidence of retinopathy was 13.9% among individuals with known diabetes. Nondiabetic individuals with retinopathy signs at baseline had a twofold higher risk of developing incident newly diagnosed diabetes 5 years later. This result provides further evidence that mild retinopathy signs may be a preclinical marker of underlying microvascular disease and future diabetes risk.

背景与目标：

BACKGROUND & AIMS: :A mathematical model is presented to study the motion of the spermatozoa in the cervical canal by considering the transverse waves along its tail and the transverse and longitudinal motions of the cervical wall. In an attempt to control fertility by reducing the speed of sperm, the transverse waves have been considered in the direction opposite to the motion of the spermatozoa. It has been shown that by having appropriate transverse wave motion and longitudinal velocity, the sperm may not be able to move towards the oviduct even if it could continue to have its own propelling velocity. A particular case of the motion of a thin plane sheet in a channel under peristaltic motion of its walls has also been obtained and studied.

背景与目标： : 提出了一个数学模型，通过考虑沿其尾部的横波以及子宫颈壁的横向和纵向运动来研究精子在子宫颈管内的运动。为了通过降低精子的速度来控制生育能力，已将横波视为与精子运动相反的方向。已经表明，通过具有适当的横波运动和纵向速度，即使精子可以继续具有自己的推进速度，也可能无法向输卵管移动。还获得并研究了薄平面在通道壁蠕动下在通道中运动的特殊情况。

BACKGROUND & AIMS: OBJECTIVES:To longitudinally assess the receptive and expressive language functioning of children with symptomatic HIV disease and to explore the relationship between immune status, computed tomography (CT) brain scan abnormalities, and language dysfunction over time. METHODS:Children with symptomatic HIV infection were administered an age-appropriate standardized comprehensive language test and general cognitive measure prior to starting antiretroviral therapy (n = 44) and again after 6 months (n = 29) and 24 months (n = 17). CD4 percentage and CT brain scans were also obtained at each evaluation. RESULTS:Expressive language was significantly more impaired than receptive language at the baseline, 6- and 24-month evaluations. No significant changes over time were found in receptive or expressive language from baseline to after 6 months of antiretroviral therapy, but despite treatment, language scores declined significantly between 6 and 24 months. Overall cognitive function, however, remained stable from baseline to 24 months. Age-adjusted CD4 percentage increased significantly over the initial 6 months, then remained stable. Overall CT brain scan severity ratings did not change significantly over 24 months. CONCLUSION:Expressive language was consistently more impaired than receptive language over 24 months, further supporting an earlier finding that expressive language was differentially affected by HIV in children with symptomatic disease. Both receptive and expressive language declined significantly after 24 months despite antiretroviral therapy, although overall cognitive function remained stable. Thus, functioning in some domains may be more vulnerable to the effects of HIV and global measures of cognitive ability may mask such differential changes in specific brain functions.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:To examine dementia characteristics, age at onset and associated comorbidities in persons with Down syndrome. METHOD:Seventy-seven people with Down syndrome aged 35 years and older were followed longitudinally. The diagnosis of dementia was established using the modified International Classification of Diseases, Tenth Revision (ICD-10) criteria and a combination of objective and informant-based tests. Cognitive tests included the Test for Severe Impairment and the Down Syndrome Mental Status Examination; adaptive behaviour was measured using the Daily Living Skills Questionnaire. The Dementia Questionnaire for Mental Retarded Persons (DMR) was added to the test battery in 2005 and this study includes follow-up data for this instrument. RESULTS:Over the 14-year period the average age of diagnosis at 55.41 years (SD = 7.14) was in the higher range of previously reported estimates (51-56 years) and a median survival of 7 years after diagnosis. Persons with dementia in the sample were significantly older than persons without dementia. The presence of dementia was also associated with epilepsy and sensory impairments. Among instruments the DMR appeared most sensitive to tracking change in symptoms over time before diagnosis. CONCLUSION:The previously reported high risk levels for dementia among people with Down syndrome was confirmed in these data as was the value of the instruments utilised in tracking decline and helping to confirm diagnosis even in persons with severe intellectual disability.

背景与目标：