Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 35
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Nature ; 584(7822): 602-607, 2020 08.
Article in English | MEDLINE | ID: mdl-32641831

ABSTRACT

Species often include multiple ecotypes that are adapted to different environments1. However, it is unclear how ecotypes arise and how their distinctive combinations of adaptive alleles are maintained despite hybridization with non-adapted populations2-4. Here, by resequencing 1,506 wild sunflowers from 3 species (Helianthus annuus, Helianthus petiolaris and Helianthus argophyllus), we identify 37 large (1-100 Mbp in size), non-recombining haplotype blocks that are associated with numerous ecologically relevant traits, as well as soil and climate characteristics. Limited recombination in these haplotype blocks keeps adaptive alleles together, and these regions differentiate sunflower ecotypes. For example, haplotype blocks control a 77-day difference in flowering between ecotypes of the silverleaf sunflower H. argophyllus (probably through deletion of a homologue of FLOWERING LOCUS T (FT)), and are associated with seed size, flowering time and soil fertility in dune-adapted sunflowers. These haplotypes are highly divergent, frequently associated with structural variants and often appear to represent introgressions from other-possibly now-extinct-congeners. These results highlight a pervasive role of structural variation in ecotypic adaptation.


Subject(s)
Ecotype , Haplotypes , Helianthus/genetics , Acclimatization/genetics , Alleles , Flowers/genetics , Helianthus/anatomy & histology , Helianthus/growth & development , Phylogeny , Seeds/genetics
2.
Gerontology ; 68(3): 272-279, 2022.
Article in English | MEDLINE | ID: mdl-34186535

ABSTRACT

BACKGROUND: Sex differences for subsequent falls and falls risk factors in community-dwelling older adults who have fallen are unknown. Our aim was to: (1) compare the number of falls between sexes, (2) identify modifiable falls risk factors, and (3) explore the interaction of sex on falls risk factors in older adults who fall. METHODS: Four hundred sixty-two community dwellers seeking medical attention after an index fall were recruited from the Vancouver Falls Prevention Clinic and participated in this 12-month prospective cohort study. Ninety-six participants were part of a randomized controlled trial of exercise. Falls were tracked with monthly falls calendars. Demographics, falls risk measures, and the number of subsequent falls were compared between sexes. A principal component analysis (PCA) was employed to reduce the falls risk measures to a smaller set of factors. The PCA factors were used in negative binomial regression models to predict the number of subsequent falls. Age, exposure time (i.e., number of falls monitoring days), and prescribed exercise (yes/no) were used as covariates, and sex (male/female) and PCA factors were used as main effects. The interaction of sex by PCA factor was then included. RESULTS: Males fell more over 12 months (males: 2.80 ± 6.86 falls; females: 1.25 ± 2.63 falls) than females, and poorer executive function predicted falls in males. Four PCA factors were defined - impaired cognition and mobility, low mood and self-efficacy, mobility resilience, and perceived poor health - each predicted the number of falls. The sex by mobility resilience interaction suggested that mobility resilience was less protective of falls in males. CONCLUSION: Modifiable risk factors related to cognition, physical function, psychological wellbeing, and health status predicted subsequent falls. In males, better mobility was not as protective of falls compared with females. This may be due to males' poorer executive function, contributing to decreased judgement or slowed decision-making during mobility. These results may inform efficacious sex-specific falls prevention strategies.


Subject(s)
Independent Living , Sex Characteristics , Aged , Cognition , Female , Humans , Male , Prospective Studies
3.
Qual Life Res ; 26(3): 737-747, 2017 03.
Article in English | MEDLINE | ID: mdl-28005242

ABSTRACT

PURPOSE: Preference-based generic measures are gaining increased use in mobility research to assess health-related quality of life and wellbeing. Hence, we examined the responsiveness of these two measures among individuals at risk of mobility impairment among adults aged ≥70 years. METHODS: We conducted a 12-month prospective cohort study of community-dwelling older adults (n = 288 to n = 341 depending on analysis) who were seen at the Vancouver Falls Prevention Clinic who had a history of at least one fall in the previous 12 months. We compared the responsiveness of the EuroQol-5 Domain-3 Level (EQ-5D-3L) and the index of capability for older adults (ICECAP-O) by examining changes in these measures over time (i.e., over 6 and 12 months) and by examining whether their changes varied as a function of having experienced 2 or more falls over 6 and 12 months. RESULTS: Only the ICECAP-O showed a significant change over time from baseline through 12 months; however, neither measure showed change that exceeded the standard error of the mean. Both measures were responsive to falls that occurred during the first 6 months of the study (p < .05). These effects appeared to be amplified among individuals identified as having mild cognitive impairment (MCI) at baseline (p < .01). Additionally, the EQ-5D-3L was responsive among fallers who did not have MCI as well as individuals with MCI who did not fall (p < .05). CONCLUSION: This study provides initial evidence suggesting that the EQ-5D-3L is generally more responsive, particularly during the first 6 months of falls tracking among older adults at risk of future mobility impairment.


Subject(s)
Accidental Falls/prevention & control , Frail Elderly/psychology , Mobility Limitation , Quality of Life , Aged , Aged, 80 and over , British Columbia , Cohort Studies , Female , Health Services for the Aged , Humans , Longitudinal Studies , Male , Prospective Studies , Reproducibility of Results
4.
Aust J Prim Health ; 22(6): 497-504, 2016 Feb.
Article in English | MEDLINE | ID: mdl-27117747

ABSTRACT

This study aimed to explore how mothers use information in home therapy programs within child development services. A grounded theory study using semistructured interviews was conducted with 14 mothers of children aged 3-6 years accessing occupational therapy, physiotherapy and speech pathology services for developmental needs. A conceptual model of mothers' information use was developed. Findings showed that the mothers went through a cyclical process of information use and decision making: acquisition (collaboration, learning preferences), appraisal (understanding, relevance), application (capacity, resourcefulness) and review (evaluation, modification), with contextual factors including information characteristics, environment, personal characteristics and relationships. Mothers who used information effectively had a sense of confidence, control and mastery, and were empowered to apply information to make decisions and adapt their child's home therapy. This study adds to knowledge about health literacy, specifically how mothers interpret and use health-related information at home. Findings will enable health professionals to address families' unique health literacy needs and empower them to support their child's optimal development, functioning and participation at their stage of life.

5.
J Adv Nurs ; 68(10): 2247-55, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22221066

ABSTRACT

AIM: This article is a report on a phenomenological study of Chinese mothers' experiences of caring for their children who were living with atopic eczema. BACKGROUND: A mother's attitude and personality may have a direct influence on her child's adherence to treatment for atopic eczema. Thus, good communication between healthcare professionals and the mother is essential. Treatment and care should also be culturally appropriate. METHODS: Using an interpretive phenomenological method, 14 interviews were conducted in Hong Kong, China from September 2007 to August 2008, with nine mothers caring for their children who were living with atopic eczema. Crist and Tanner's circular process of hermeneutic interpretive phenomenology was chosen to guide the data analysis. FINDINGS: Mothers' coping patterns involved persistently dealing with enduring demands and seeking alternative therapies that were aimed at curing the disease. Four themes finally emerged from the data: (1) dealing with extra mothering, (2) giving up their life, (3) becoming an expert and (4) living with blame and worry. Mothers' coping patterns involved persistently finding ways to relieve their children's suffering with the aim of curing the disease and dealing with their own emotions related to the frustration resulting from giving up their life and living with blame and worry. CONCLUSION: The study findings provide nurses with an empathic insight into mothers' feelings and the enduring demands of caring for children with atopic eczema, and help nurses to develop culturally sensitive interventions, reinforce positive coping strategies, increase family function and improve health outcomes.


Subject(s)
Adaptation, Psychological , Caregivers , Cost of Illness , Dermatitis, Atopic/nursing , Mothers , Adolescent , Adult , Caregivers/psychology , Child , Child, Preschool , Female , Guilt , Hong Kong , Humans , Male , Middle Aged , Mothers/psychology , Needs Assessment , Skin Care , Social Support , Stress, Psychological
6.
Nat Commun ; 13(1): 6457, 2022 10 29.
Article in English | MEDLINE | ID: mdl-36309522

ABSTRACT

Melanoma is the deadliest form of skin cancer and considered intrinsically resistant to chemotherapy. Nearly all melanomas harbor mutations that activate the RAS/mitogen-activated protein kinase (MAPK) pathway, which contributes to drug resistance via poorly described mechanisms. Herein we show that the RAS/MAPK pathway regulates the activity of cyclin-dependent kinase 12 (CDK12), which is a transcriptional CDK required for genomic stability. We find that melanoma cells harbor constitutively high CDK12 activity, and that its inhibition decreases the expression of long genes containing multiple exons, including many genes involved in DNA repair. Conversely, our results show that CDK12 inhibition promotes the expression of short genes with few exons, including many growth-promoting genes regulated by the AP-1 and NF-κB transcription factors. Inhibition of these pathways strongly synergize with CDK12 inhibitors to suppress melanoma growth, suggesting promising drug combinations for more effective melanoma treatment.


Subject(s)
Melanoma , Skin Neoplasms , Humans , Proto-Oncogene Proteins B-raf/metabolism , Melanoma/drug therapy , Melanoma/genetics , Melanoma/metabolism , Cyclin-Dependent Kinases/genetics , Cyclin-Dependent Kinases/metabolism , Skin Neoplasms/drug therapy , Skin Neoplasms/genetics , Mitogen-Activated Protein Kinases/metabolism , Cell Line, Tumor
7.
Adv Nutr ; 13(6): 2098-2114, 2022 12 22.
Article in English | MEDLINE | ID: mdl-36084013

ABSTRACT

National health and nutrition monitoring is an important federal effort in the United States and Canada, and the basis for many of their nutrition and health policies. Understanding of child exposures through human milk (HM) remains out of reach due to lack of current and representative data on HM's composition and intake volume. This article provides an overview of the current national health and nutrition monitoring activities for HM-fed children, HM composition (HMC) and volume data used for exposure assessment, categories of potential measures in HM, and associated variability factors. In this Perspective, we advocate for a framework for collection and reporting of HMC data for national health and nutrition monitoring and programmatic needs, including a shared vision for a publicly available Human Milk Composition Data Repository (HMCD-R) to include essential metadata associated with HMC. HMCD-R can provide a central, integrated platform for researchers and public health officials for compiling, evaluating, and sharing HMC data. The compiled compositional and metadata in HMCD-R would provide pertinent measures of central tendency and variability and allow use of modeling techniques to approximate compositional profiles for subgroups, providing more accurate exposure assessments for purposes of monitoring and surveillance. HMC and related metadata could facilitate understanding the complexity and variability of HM composition, provide crucial data for assessment of infant and maternal nutritional needs, and inform public health policies, food and nutrition programs, and clinical practice guidelines.


Subject(s)
Milk, Human , Nutritional Status , Infant , Child , Humans , United States , Canada
8.
Hong Kong Med J ; 17(3): 189-94, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21636866

ABSTRACT

OBJECTIVE: To provide a synopsis of current haemophilia care in Hong Kong. DESIGN: Retrospective survey. SETTING: All haematology units of the Hospital Authority in Hong Kong. PATIENTS: All patients with haemophilia A and haemophilia B. RESULTS: To date, there were 222 mild-to-severe haemophilia patients (192 type A, 30 type B) under regular public care in Hong Kong (43% were considered severe, 33% moderate, and 24% mild), which gave a crude prevalence of 6.8/100 000 male inhabitants. A total of 12.8 million units of Factor VIII and 3 million units of Factor IX were prescribed annually. This amounts to 1.83 units of FVIII per capita of the population, which is comparable to that of other developed countries. Leading causes of mortality were human immunodeficiency virus-related complications (10 cases) and cerebral bleeding (2 cases). The life expectancy of patients with severe haemophilia in Hong Kong is improving; currently the oldest patient is 60 years old. Such improved survival may be due to enhanced factor availability, prompt treatment of bleeding episodes at home, safer factor products, and better antiviral treatment. Primary prophylaxis is the accepted standard of care for severe and moderate cases, and "Factor First" has become hospital policy. However, 12 patients continue to present treatment challenges, due to the documented presence of factor inhibitors. In all, 28, 100, and 14 cases respectively were positive for human immunodeficiency virus, hepatitis C virus, and hepatitis B virus; the youngest patients with the corresponding infections being 28, 13, and 22 years old. Comprehensive care with dedicated physiotherapy, surgical support, and radionucleotide synovectomy may reduce morbidity further. CONCLUSION: A multidisciplinary approach can further improve the future care for haemophilia patients in Hong Kong.


Subject(s)
Coagulants/therapeutic use , Hemophilia A/therapy , Hemophilia B/therapy , Adolescent , Adult , Aged , Child , Child, Preschool , Factor IX/therapeutic use , Factor VIII/therapeutic use , Hemophilia A/epidemiology , Hemophilia A/physiopathology , Hemophilia B/epidemiology , Hemophilia B/physiopathology , Hong Kong/epidemiology , Humans , Infant , Life Expectancy , Male , Middle Aged , Prevalence , Retrospective Studies , Severity of Illness Index , Young Adult
9.
Front Surg ; 8: 753801, 2021.
Article in English | MEDLINE | ID: mdl-34957199

ABSTRACT

Lung cancer is a complex milieu of genomically altered cancer cells, a diverse collection of differentiated cells and nonneoplastic stroma. Lung cancer organoids is a three-dimensional structure grown from patient cancer tissue that could mimic in vivo complex behavior and cellular architecture of the cancer. Furthermore, the genomic alterations of the primary lung tumor is captured ex vivo. Lung cancer organoids have become an important preclinical model for oncology studies in recent years. It could be used to model the development of lung cancer, investigate the process of tumorigenesis, and also study the signaling pathways. The organoids could also be a platform to perform drug screening and biomarker validation of lung cancer, providing a promising prediction of patient-specific drug response. In this review, we described how lung cancer organoids have opened new avenues for translating basic cancer research into clinical therapy and discussed the latest and future developments in organoid technology, which could be further applied in lung cancer organoids research.

10.
Placenta ; 94: 13-19, 2020 05.
Article in English | MEDLINE | ID: mdl-32217266

ABSTRACT

BACKGROUND: Placental perfusion can be evaluated by 3D power Doppler ultrasound (3D PD-US), particularly using the validated tool 3D Fractional Moving Blood Volume (3D-FMBV); however regional variability and size limitations beyond the first trimester mean that multiple 3D PD-US volumes are required to evaluate the whole organ. PURPOSE: We assessed the feasibility of manual offline stitching of second trimester 3D PD-US volumes of the placenta to assess whole organ perfusion using 3D-FMBV. MATERIALS AND METHODS: This was a single-centre, prospective, observational cohort study of 36 normal second trimester singleton pregnancies with anterior placentas. 3D PD-US placental volumes were manually segmented offline and stitched together by rigid registration using manually selected, pair-wise coordinates. Data acquisition and offline volume segmentation and stitching were triplicated by a single observer with Dice similarity coefficient (DSC) and Hausdorff distance used to assess consistency. Intraclass correlation coefficient (ICC) was used to assess intra-observer repeatability of 3D-FMBV and placental volume. RESULTS: Acquisition and stitching success were 94% and 88%, respectively. Median time for acquisition, segmentation and stitching were 13 min, 40 min and 95 min, respectively. Median intra-observer DSCs were 0.94 and 0.88, and Hausdorff distances were 11.85 mm and 36.6 mm, for segmentations and stitching, respectively. CONCLUSION: 3D-ultrasound volume stitching of the placenta is technically feasible. Intra-observer repeatability was good to excellent for all measured parameters. This work demonstrates technical feasibility; further studies may provide the basis of an in-vivo assessment tool to measure the placenta in mid-to late pregnancy.


Subject(s)
Imaging, Three-Dimensional/methods , Placenta/blood supply , Ultrasonography, Doppler/methods , Ultrasonography, Prenatal/methods , Adult , Blood Volume , Feasibility Studies , Female , Gestational Age , Humans , Observer Variation , Pregnancy , Pregnancy Trimester, Second , Prospective Studies
11.
Hepatology ; 48(2): 1-10, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18452145

ABSTRACT

UNLABELLED: Whether preemptive anti- hepatitis B virus (HBV) therapy should be considered in all hepatitis B surface antigen (HBsAg)-negative patients with occult HBV infection receiving alemtuzumab containing chemotherapy is uncertain. We determined the outcome and effect on HBV-specific immunity of an alemtuzumab-containing chemotherapy regimen in occult HBV-infected patients. Twenty-one consecutive occult HBV-infected patients treated with an alemtuzumab containing chemotherapy regimen were studied. T cell reactivity to HBV antigens and -peptides were quantified by ELISpot and the T cell subset by flow cytometry. Six of the 21 patients (28.6%) developed HBsAg seroreversion. The median (range) time to development of HBsAg seroreversion after the end of chemotherapy was 1.8 months (0.2-2.3 months). Direct sequencing showed that the occult HBV infection of all six patients (100%) was reactivated. These six patients developed severe HBV-related hepatitis. At the end of follow-up, four of these six patients (66.7%) had become negative for HBsAg again. Recovery of CD4+ T cell count and CD4+T cell reactivity against hepatitis B core antigen (HBcAg) occurred 9 months after the end of chemotherapy. Loss of HBsAg occurred after recovery of the CD4+T cell count and increased CD4+T cell reactivity against HBcAg 9 months after the end of chemotherapy. CONCLUSION: An alemtuzumab-containing chemotherapy regimen is associated with a high risk of reactivation of occult HBV infection. Suppression of HBV immunity by an alemtuzumab-containing chemotherapy regimen would persist until 9 months after the end of chemotherapy. In occult HBV-infected patients receiving an alemtuzumab-containing chemotherapy regimen, preemptive anti-HBV therapy should be continued until 9 months after the end of chemotherapy, when recovery of HBV immunity has occurred.

12.
Leuk Res ; 32(4): 547-51, 2008 Apr.
Article in English | MEDLINE | ID: mdl-17714782

ABSTRACT

Twenty-seven patients received the anti-CD52 monoclonal antibody alemtuzumab for hematologic malignancies and autoimmune cytopenias in a tuberculosis-endemic area. Seven patients developed mycobacterium tuberculosis (TB) infections (median: 4, 1-24, months from alemtuzumab). The actuarial 1- and 2-year incidence of TB was 31% and 45%. All patients had severe depression of lymphocyte counts subsequent to alemtuzumab treatment, and tuberculosis was extra-pulmonary in three cases. All seven patients had received prior chemotherapy/immunosuppression and tuberculosis had not occurred until alemtuzumab was administered. Patients receiving alemtuzumab in areas endemic for tuberculosis should have careful initial evaluation of TB exposure, so that prophylactic antibiotics might be administered. Tuberculosis reactivation should be considered for unexplained fever and symptoms after alemtuzumab treatment.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Antibodies, Neoplasm/therapeutic use , Antineoplastic Agents/therapeutic use , Asian People , Lymphoproliferative Disorders/drug therapy , Mycobacterium tuberculosis/pathogenicity , Tuberculosis/epidemiology , Adult , Aged , Aged, 80 and over , Alemtuzumab , Antibodies, Monoclonal, Humanized , Cohort Studies , Female , Follow-Up Studies , Hong Kong/epidemiology , Humans , Immunosuppressive Agents , Incidence , Lymphoproliferative Disorders/complications , Male , Middle Aged , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Tuberculosis/microbiology , Tuberculosis/mortality
13.
Front Aging Neurosci ; 10: 240, 2018.
Article in English | MEDLINE | ID: mdl-30131690

ABSTRACT

Background: There has been much research devoted to examining the short-term effects of different interventions for improving memory functioning of older adults with memory complaints. Nevertheless, very few studies have examined the long-term effects of these interventions. Thus, the present study compared the sustained effects of a conventional memory intervention (MI) and a Chinese lifestyle intervention on improving memory functioning in older adults. Methods: Twenty-nine older adults who were aged 60 years and older and had memory complaints were recruited. Each completed 10 weekly sessions of the Dejian Mind-body Intervention (DMBI; n = 11) or MI (n = 18) approximately 18 months ago. Participants' verbal and visual memory functioning and their subjective impression of the changes of their memory performance and physical and psychological health status were evaluated. Results: Results showed significant improvements in memory in both intervention groups at the follow-up assessments when compared with baseline. In addition, older adults in both intervention groups perceived improved memory performance and physical and psychological wellness at follow-up, with the DMBI group reporting significantly greater improvements in physical health compared to the MI group. Conclusion: Altogether, the present study provides supportive evidence that the DMBI and MI might be two effective remedies for older adults to improve or preserve their memory functioning with relatively sustained effects.

14.
Front Psychol ; 9: 742, 2018.
Article in English | MEDLINE | ID: mdl-29867694

ABSTRACT

Individuals with partial sleep deprivation may have working memory (WM) impairment, but the underlying neural mechanism of this phenomenon is relatively unknown. The present study examined neural processing during WM performance in individuals with and without partial sleep deprivation using near-infrared spectroscopy (NIRS). Forty college students (10 males) were equally split into Sufficient Sleep (SS) and Insufficient Sleep (IS) groups based on self-reports of previous night's sleep duration. Participants in the SS group obtained the recommended amounts of sleep according to various sleep organizations (i.e., >7.0 h), whereas those in the IS group obtained amounts of sleep no greater than the lower limit of the recommendation (i.e., ≤7.0 h). All participants underwent an n-back paradigm with a WM load (i.e., 3-back) and a control condition (i.e., 0-back) while their prefrontal hemodynamics were recorded by NIRS. The IS and SS groups performed the tasks comparably well. However, unlike the SS group, which exhibited bilateral frontal activation indicated by increased oxyhemoglobin concentration and decreased deoxyhemoglobin concentration during WM processing (i.e., 3-back > 0-back), the IS group did not exhibit such activation. In addition, levels of WM-related frontal activation, especially those on the left side, correlated with sleep duration the night before, even when habitual sleep duration was controlled for. The findings suggest the presence of frontal lobe dysfunction in the absence of evident WM difficulties in individuals with acute partial sleep deprivation. They also highlight the importance of a good night's sleep to brain health.

15.
BMJ Open ; 8(12): e020576, 2018 12 04.
Article in English | MEDLINE | ID: mdl-30518579

ABSTRACT

OBJECTIVE: We assessed the feasibility and acceptability of delivering a geriatrician-led evidence-based Falls Prevention Clinic to older adults with a history of falls. DESIGN: 12-month prospective cohort study. SETTING: Vancouver Falls Prevention Clinic, Vancouver, British Columbia, Canada (www.fallsclinic.ca). PARTICIPANTS: 188 community-dwelling older adults aged ≥70 years who received a baseline assessment at the Vancouver Falls Prevention Clinic due to having had at least one fall resulting in medical attention in the previous 12 months. Fifty-six per cent of participants were also participating in a randomised controlled trial. MEASUREMENTS: Feasibility was ascertained by measuring demand (clinic attendance). Acceptability was measured by compliance with recommendations, completion of monthly fall calendars and patient experience. RESULTS: The attendance was 65% of those eligible and invited. This indicates feasibility for demand. 155 received at least one of the following clinical management recommendations from four domains (compliance reported in %): (1) medication changes (78%); (2) exercise prescription (58%); (3) referrals to other healthcare professionals (78%); and/or (4) lifestyle modifications (35%) excluding exercise. Overall compliance to all recommendations was 69%. Patient experience was related to factors impacting patient perceived physical benefit and attributes influencing patient satisfaction. CONCLUSION: This study demonstrated the feasibility and acceptability of a multifactorial intervention approach based on best available evidence-based medicine.


Subject(s)
Accidental Falls/prevention & control , Ambulatory Care Facilities , Patient Compliance/statistics & numerical data , Patient Participation/statistics & numerical data , Aged , Aged, 80 and over , British Columbia , Cohort Studies , Exercise , Feasibility Studies , Female , Geriatric Assessment , Geriatricians , Humans , Life Style , Male , Medication Reconciliation , Patient Satisfaction , Referral and Consultation
16.
PLoS One ; 13(12): e0207429, 2018.
Article in English | MEDLINE | ID: mdl-30540776

ABSTRACT

The US Institute of Medicine defined serum 25-hydroxyvitamin D (25OHD) cut point values of 30 nmol/L and 40 nmol/L were used to assess the vitamin D status of South Asian and European Canadians of self-identified ancestry living in the National Capital Region of Canada. Serum 25OHD values were measured in the spring and fall of 2012 to represent status during the winter and summer months, respectively. A total of 1238 measurements were obtained from 669 participants (49% South Asian ancestry): some participants were measured only once (spring or fall). Median 25OHD values were significantly higher in participants of European ancestry: 70.8 nmol/L (68.1, 73.5; 95% CI) versus South Asian ancestry: 42.7 nmol/L (40.5, 45.0; P<0.001). Spring vs. fall differences were small for each ethnic group and significant only for those of European ancestry (2.9, CI: 1.0-4.9 nmol/L; P = 0.01). Among participants of South Asian ancestry, 27.3% (fall) and 29.1% (spring) of females had values <40 nmol/L while the percentages for males were considerably higher (36.5% and 44.2%, respectively). The corresponding values for participants of European ancestry were ≤10%, showing that the South Asian participants were less likely to achieve the 25OHD concentrations established by the IOM for optimum bone health. Investigation of the factors related to serum 25OHD levels showed that supplement intake and ethnic background were associated with the biggest differences. Skin color was not a major factor, suggesting that genetic factors are responsible for the observed differences between participants of different ethnic backgrounds.


Subject(s)
Vitamin D Deficiency/diagnosis , Vitamin D/analogs & derivatives , Adult , Aged , Asian People , Canada/epidemiology , Dietary Supplements , Female , Humans , Male , Middle Aged , Prevalence , Seasons , Skin Pigmentation , Surveys and Questionnaires , Vitamin D/blood , Vitamin D Deficiency/epidemiology , White People , Young Adult
18.
Front Immunol ; 8: 11, 2017.
Article in English | MEDLINE | ID: mdl-28167942

ABSTRACT

Previous studies have shown that immunological factors are involved in the pathogenesis of autism spectrum disorders (ASDs). However, this research has been conducted almost exclusively in Western contexts, and only a handful of studies on immune measures have been conducted in Asian populations, such as Chinese populations. The present study examined whether immunological abnormalities are associated with cognitive deficits and problem behaviors in Chinese children with ASD and whether these children show different immunological profiles. Thirteen typically developing (TD) children and 22 children with ASD, aged 6-17 years, participated voluntarily in the study. Executive functions and short-term memory were measured using neuropsychological tests, and behavioral measures were assessed using parent ratings. The children were also assessed on immunological measures, specifically, the levels of cytokines and chemokines in the blood serum. Children with ASD showed greater deficits in cognitive functions, as well as altered levels of immunological measures, including CCL2, CCL5, and CXCL9 levels, compared to TD children, and the cognitive functions and associated behavioral deficits of children with ASD were significantly associated with different immunological measures. The children were further sub-classified into ASD with only autistic features (ASD-only) or ASD comorbid with attention deficit hyperactivity disorder (ASD + ADHD). The comorbidity results showed that there were no differences between the two groups of ASD children in any of the cognitive or behavioral measures. However, the results pertaining to immunological measures showed that the children with ASD-only and ASD + ADHD exhibited distinct cytokine and chemokine profiles and that abnormal immunologic function was associated with cognitive functions and inattention/hyperactivity symptoms. These results support the notion that altered immune functions may play a role in the selective cognitive and behavioral symptoms of ASD.

19.
J Alzheimers Dis ; 60(4): 1397-1410, 2017.
Article in English | MEDLINE | ID: mdl-29036816

ABSTRACT

Aerobic training (AT) is a promising, non-pharmacological intervention to mitigate the deleterious effects of aging and disease on brain health. However, a large amount of variation exists in its efficacy. This is a secondary analysis of a randomized controlled trial of AT in 71 older adults with subcortical ischemic vascular cognitive impairment (NCT01027858). Specifically, we investigated: 1) whether sex moderates the relationship between AT and executive functions, and 2) the role of brain derived neurotrophic factor (BDNF) and gains in functional fitness capacity. Older adults were randomly assigned to either 6-month, thrice-weekly AT or to usual care plus education (CON). At baseline, trial completion, and 6-month follow-up, executive functions were assessed with the Trail Making Test (A & B), verbal digits forward and backward test, and the Stroop Test. Functional fitness capacity was assessed with the 6-Minute Walk Test. Compared with CON, AT significantly improved Trail Making Test performance in females but not males, an effect that was retained at follow-up. AT significantly increased BDNF levels in females but decreased levels in males. On the other hand, AT led to significant gains in functional fitness capacity in males only. This study provides evidence that sex differences exist in AT efficacy on brain health as well as in the biological mechanisms subserving AT.


Subject(s)
Brain Ischemia/therapy , Cognition , Cognitive Dysfunction/therapy , Exercise Therapy , Sex Characteristics , Aged , Brain Ischemia/physiopathology , Brain Ischemia/psychology , Brain-Derived Neurotrophic Factor/blood , Cognitive Dysfunction/physiopathology , Cognitive Dysfunction/psychology , Exercise Test , Female , Follow-Up Studies , Humans , Male , Neuropsychological Tests , Single-Blind Method , Treatment Outcome
20.
Front Hum Neurosci ; 11: 344, 2017.
Article in English | MEDLINE | ID: mdl-28713255

ABSTRACT

Impaired mobility is a major concern for older adults and has significant consequences. While the widely accepted belief is that improved physical function underlies the effectiveness of targeted exercise training in improving mobility and reducing falls, recent evidence suggests cognitive and neural benefits gained through exercise may also play an important role in promoting mobility. However, the underlying neural mechanisms of this relationship are currently unclear. Thus, we hypothesize that 6 months of progressive aerobic exercise training would alter frontoparietal network (FPN) connectivity during a motor task among older adults with mild subcortical ischemic vascular cognitive impairment (SIVCI)-and exercise-induced changes in FPN connectivity would correlate with changes in mobility. We focused on the FPN as it is involved in top-down attentional control as well as motor planning and motor execution. Participants were randomized either to usual-care (CON), which included monthly educational materials about VCI and healthy diet; or thrice-weekly aerobic training (AT), which was walking outdoors with progressive intensity. Functional magnetic resonance imaging was acquired at baseline and trial completion, where the participants were instructed to perform bilateral finger tapping task. At trial completion, compared with AT, CON showed significantly increased FPN connectivity strength during right finger tapping (p < 0.05). Across the participants, reduced FPN connectivity was associated with greater cardiovascular capacity (p = 0.05). In the AT group, reduced FPN connectivity was significantly associated with improved mobility performance, as measured by the Timed-Up-and-Go test (r = 0.67, p = 0.02). These results suggest progressive AT may improve mobility in older adults with SIVCI via maintaining intra-network connectivity of the FPN.

SELECTION OF CITATIONS
SEARCH DETAIL