22 results on '"Duren, D."'
Search Results
2. Automatic multi-structure pediatric knee bone segmentation using optimal multi-level Otsu thresholding to tackle intensity homogeneity in bone structures.
- Author
-
K N, T G, A S, D D, D P, T E M, and B B
- Subjects
- Humans, Child, Knee Joint diagnostic imaging, Bone and Bones, Magnetic Resonance Imaging, Knee, Algorithms
- Abstract
Recent studies in medical image segmentation involve new automatic approaches where active learning models are useful with less training samples. Presence of homogenous and heterogenous intensities for a single anatomical structure in pediatric musculoskeletal MR images affects the accuracy in terms of segmentation and classification of labels. This study addresses the homogeneity in intensity issues and introduces a new pre-training pipeline framework of Multi-level Otsu thresholding image as separate channel for 3D UNet model training. The proposed framework achieved higher performance of up to 85% when compared with the Baseline 3D UNet model and the Histogram threshold with 3D UNet. All algorithms are run through MONAI core framework.Clinical Relevance- This study will be of major interest to practicing pediatric clinicians and surgeons for its ability to provide accurate morphological assessment of underlying musculoskeletal structure. For researchers, it provides a new approach in dealing with heterogeneity in intensity problem which is common in pediatric MR imaging.
- Published
- 2023
- Full Text
- View/download PDF
3. Sex Trafficking and Substance Use: Identifying High-Priority Needs Within the Criminal Justice System.
- Author
-
Langton L, Planty MG, Banks D, Witwer AR, Woods D, Vermeer MJD, and Jackson BA
- Abstract
Substance use disorder (SUD) is common among victims of sex trafficking. Traffickers may exploit individuals' existing opioid use or other SUDs to coerce them into sex trafficking, or they may facilitate substance use to keep trafficking victims from exiting. Additionally, trafficking victims may use substances to cope with trauma. The intersections of sex trafficking and SUD complicate both legal responses and victim advocate responses to sex trafficking cases. Victim SUD can lead to challenges for law enforcement and prosecutors in developing cases against traffickers. On the provider side, traditional victim services are often insufficient for victims of trafficking with SUDs, who face substantial barriers to accessing services. A better understanding of the nexus between sex trafficking and SUDs is critical for implementing victim-centered and trauma-informed responses to this vulnerable population. In this article, the authors describe an online panel, convened in April 2021 by RTI International and the RAND Corporation on behalf of the National Institute of Justice, in which subject-matter experts and criminal justice practitioners discussed how SUDs and sex trafficking complicate the identification and screening of victims and victims' ability to access treatment and legal remedies. The panel participants identified 21 high-priority needs to support a better understanding of sex trafficking and SUDs and a variety of solutions for addressing these intertwined issues., (Copyright © 2022 RAND Corporation.)
- Published
- 2022
4. Bipolar I Disorder Exacerbation Following COVID-19 Vaccination.
- Author
-
Guina J, Barlow S, and Gutierrez D
- Abstract
We present the cases of a 60-year-old female patient and 40-year-old male patient who experienced exacerbations of previously well-controlled symptoms of bipolar I disorder (BD1) after receiving COVID-19 vaccines, despite being stable for years on the same medications. The first patient experienced worsened depression, mania, and psychosis that improved with an increase in risperidone. The second patient experienced depression, mania, psychosis, and suicidal ideation that resulted in hospitalization. Prior to hospitalization, he took lamotrigine and bupropion, the latter of which was changed to aripiprazole in hospital. We reviewed current literature on inflammation in mental disorders, vaccination-related inflammatory changes, and the type of inflammation induced by COVID-19 vaccines. Inflammation is a component of psychiatric disorders, and the inflammatory response induced by vaccines might potentiate acute mental health exacerbations, necessitating treatment changes. However, this case series should not be used to justify recommendations against vaccination without larger, well-designed studies. At this time, the known benefits of vaccination outweigh these unknown risks, especially because individuals with serious mental illness are more likely to die from COVID-19 than the general population., Competing Interests: DISCLOSURES: The authors have no conflicts of interest relevant to the content of this article., (Copyright © 2022. Matrix Medical Communications. All rights reserved.)
- Published
- 2022
5. Anesthesia For Laryngeal Surgery
- Author
-
Balmert NJ and Duren D
- Abstract
Laryngeal pathology can be related to trauma, infection, malignancy, or, in children, congenital malformation of laryngeal structures.[1] Surgery on the laryngeal structures can lead to major complications, and anesthetic management must be carefully communicated and planned. Selection of the mode of ventilation and associated airway management technique depends on patient factors, surgery length, and type of laryngeal disease. This choice is influenced by the need to share the airway with the surgeon, the potential for difficult intubation, and the effects of treatment for laryngeal pathology before surgery. Four methods have been devised to secure the airway and deliver oxygen to patients undergoing laryngeal surgery: mechanical ventilation, spontaneous ventilation, subglottic jet ventilation, and intermittent apneic anesthesia. Complications can arise from each ventilation strategy. Interdisciplinary planning and communication are key so that necessary adaptations can occur intraoperatively., (Copyright © 2022, StatPearls Publishing LLC.)
- Published
- 2022
6. Quality Improvement in Neurology: Headache Quality Measurement Set.
- Author
-
Robbins MS, Victorio MCC, Bailey M, Cook C, Garza I, Huff JS, Ready D, Schuster NM, Seidenwurm D, Seng E, Szperka C, Lee E, and Villanueva R
- Subjects
- Humans, Diagnostic Techniques, Neurological standards, Headache Disorders, Primary diagnosis, Quality Improvement standards
- Published
- 2021
- Full Text
- View/download PDF
7. Quality improvement in neurology: Headache Quality Measurement Set.
- Author
-
Robbins MS, Victorio MC, Bailey M, Cook C, Garza I, Huff JS, Ready D, Schuster NM, Seidenwurm D, Seng E, Szperka C, Lee E, and Villanueva R
- Subjects
- Cluster Headache therapy, Counseling, Headache Disorders, Humans, Migraine Disorders therapy, Quality Improvement, Cluster Headache prevention & control, Documentation, Migraine Disorders prevention & control, Neurology standards, Quality Indicators, Health Care, Risk Reduction Behavior, Treatment Adherence and Compliance
- Published
- 2020
- Full Text
- View/download PDF
8. Predicting adult facial type from mandibular landmark data at young ages.
- Author
-
Oh H, Knigge R, Hardin A, Sherwood R, Duren D, Valiathan M, Leary E, and McNulty K
- Subjects
- Adolescent, Adult, Cephalometry, Child, Humans, Young Adult, Face, Mandible
- Abstract
Objectives: To assess the potential of predicting adult facial types at different stages of mandibular development., Setting and Sample Population: A total of 941 participants from the Bolton-Brush, Denver, Fels, Iowa, Michigan and Oregon growth studies with longitudinal lateral cephalograms (total of 7166) between ages 6-21 years., Material and Methods: Each participant was placed into one of three facial types based on mandibular plane angle (MPA) from cephalograms taken closest to 18 years of age (range of 15-21 years): hypo-divergent (MPA < 28°), normo-divergent (28°≤ MPA ≤ 39°) and hyper-divergent (MPA > 39°). Cephalograms were categorized into 13 age groups 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 and 18-21. Twenty-three two-dimensional anatomical landmarks were digitized on the mandible and superimposed using generalized Procrustes analysis, which projects landmarks into a common shape space. Data were analysed within age categories using stepwise discriminant analysis to identify landmarks that distinguish adult facial types and by jackknife cross-validation to test how well young individuals can be reclassified into their adult facial types., Results: Although each category has multiple best discriminating landmarks among adult types, three landmarks were common across nearly all age categories: menton, gonion and articulare. Individuals were correctly classified better than chance, even among the youngest age category. Cross-validation rates improved with age, and hyper- and hypo-divergent groups have better reclassification rates than the normo-divergent group., Conclusions: The discovery of important indicators of adult facial type in the developing mandible helps improve our capacity to predict adult facial types at a younger age., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
- Published
- 2019
- Full Text
- View/download PDF
9. Evaluation of a randomized intervention to increase adoption of comparative effectiveness research by community health organizations.
- Author
-
Williams JR, Williams WO, Dusablon T, Blais MP, Tregear SJ, Banks D, and Hennessy KD
- Subjects
- Community Health Services, Decision Making, Humans, Male, Randomized Controlled Trials as Topic, Translational Research, Biomedical, Comparative Effectiveness Research, Diffusion of Innovation, Evidence-Based Medicine, Motivational Interviewing methods, Program Evaluation methods
- Abstract
This randomized controlled trial examined the influence of two strategies (informational packets alone and in conjunction with Webinars) aimed at increasing the adoption of motivational interviewing (MI), a patient-centered behavioral health practice supported by evidence from comparative effectiveness studies, among community health organizations responsible for delivering mental and behavioral health services. Data were obtained from 311 directors and staff across 92 community organizations. Hierarchical linear modeling was used to examine changes in decision to adopt MI. The mediating effects of multiple contextual variables were also examined. Results showed that both strategies positively influenced the decision to adopt. The positive impact on decision to adopt was significantly greater among individuals that received informational packets in conjunction with Webinars. Baseline attitudes toward evidence-based practices and pressures for change appeared to mediate this effect.
- Published
- 2014
- Full Text
- View/download PDF
10. Predictors of the decision to adopt motivational interviewing in community health settings.
- Author
-
Williams JR, Blais MP, Banks D, Dusablon T, Williams WO, and Hennessy KD
- Subjects
- Decision Making, Decision Making, Organizational, Health Services Needs and Demand, Humans, Organizational Innovation, Public Health, Community Health Services organization & administration, Comparative Effectiveness Research, Diffusion of Innovation, Evidence-Based Practice methods, Motivational Interviewing
- Abstract
The purpose of this study is to concurrently examine the impact of individual and organizational characteristics on the decision to adopt the evidence-based practice (EBP) motivational interviewing (MI) among directors and staff (n = 311) in community health organizations (n = 92). Results from hierarchical linear modeling indicated that, at the individual level, attitudes toward EBPs and race each predicted directors' decisions to adopt, while gender predicted staff's decisionmaking. At the organizational level, organizational climate was inversely associated with both staff's and directors' decisions to adopt MI. Organizational barriers to implementing EBPs and use of reading materials and treatment manuals were related to directors' decision to adopt. Type of organization and staff attributes were associated with staff's decision to adopt. These findings underscore the need to tailor dissemination and implementation strategies to address differences between directors and staff in the adoption of EBPs.
- Published
- 2014
- Full Text
- View/download PDF
11. MAINTAINING FUNCTION WITH AGING WHAT WE HAVE LEARNED FROM THE FELS LONGITUDINAL STUDY.
- Author
-
Chumlea WC, Choh A, Lee M, Towne B, Duren D, Siervogel RM, and Czerwmski S
- Published
- 2012
12. Genome-wide linkage scan for quantitative trait loci underlying normal variation in heel bone ultrasound measures.
- Author
-
Lee M, Choh AC, Williams KD, Schroeder V, Dyer TD, Blangero J, Cole SA, Chumlea WC, Duren DL, Sherwood RJ, Siervogel RM, Towne B, and Czerwinski SA
- Subjects
- Adolescent, Adult, Family, Female, Genetic Markers, Genome, Genotype, Humans, Longitudinal Studies, Male, Microsatellite Repeats, Middle Aged, Quantitative Trait, Heritable, Reference Values, Ultrasonography, Young Adult, Bone Density genetics, Calcaneus diagnostic imaging, Chromosomes, Human, Pair 11, Genetic Linkage, Genetic Variation, Quantitative Trait Loci
- Abstract
Quantitative ultrasound (QUS) traits are correlated with bone mineral density (BMD), but predict risk for future fracture independent of BMD. Only a few studies, however, have sought to identify specific genes influencing calcaneal QUS measures. The aim of this study was to conduct a genome-wide linkage scan to identify quantitative trait loci (QTL) influencing normal variation in QUS traits. QUS measures were collected from a total of 719 individuals (336 males and 383 females) from the Fels Longitudinal Study who have been genotyped and have at least one set of QUS measurements. Participants ranged in age from 18.0 to 96.6 years and were distributed across 110 nuclear and extended families. Using the Sahara ® bone sonometer, broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness index (QUI) were collected from the right heel. Variance components based linkage analysis was performed on the three traits using 400 polymorphic short tandem repeat (STR) markers spaced approximately 10 cM apart across the autosomes to identify QTL influencing the QUS traits. Age, sex, and other significant covariates were simultaneously adjusted. Heritability estimates (h²) for the QUS traits ranged from 0.42 to 0.57. Significant evidence for a QTL influencing BUA was found on chromosome 11p15 near marker D11S902 (LOD = 3.11). Our results provide additional evidence for a QTL on chromosome 11p that harbors a potential candidate gene(s) related to BUA and bone metabolism.
- Published
- 2012
- Full Text
- View/download PDF
13. Longitudinal changes in calcaneal quantitative ultrasound measures during childhood.
- Author
-
Lee M, Nahhas RW, Choh AC, Demerath EW, Duren DL, Chumlea WC, Sherwood RJ, Towne B, Siervogel RM, and Czerwinski SA
- Subjects
- Adiposity, Age Determination by Skeleton, Aging physiology, Body Mass Index, Calcaneus physiology, Child, Female, Humans, Longitudinal Studies, Male, Motor Activity physiology, Sex Characteristics, Sports physiology, Ultrasonography, Bone Density physiology, Calcaneus diagnostic imaging, Calcaneus growth & development
- Abstract
Unlabelled: This longitudinal study examined how calcaneal quantitative ultrasound (QUS) measures change during childhood while taking into account skeletal maturation, body mass index (BMI), and physical activity. The study reported sex differences in QUS growth curves and an inverse relationship between BMI and speed of sound (SOS) measures., Introduction: The aim of this study was to examine how calcaneal QUS parameters change over time during childhood and to determine what factors influence these changes., Methods: The study sample consisted of a total of 192 Caucasian children participating in the Fels Longitudinal Study. A total of 548 calcaneal broadband ultrasound attenuation (BUA) and SOS observations were obtained between the ages of 7.6 and 18 years. The best fitting growth curves were determined using statistical methods for linear mixed effect models., Results: There are significant sex differences in the pattern of change in QUS parameters (p < 0.05). The relationship between QUS measures and skeletal age is best described by a cubic growth curve in boys and a linear pattern among girls. Boys experience their most rapid growth in BUA and SOS in early and late adolescence, while girls experience constant growth throughout childhood. Adiposity levels were significantly associated with the changes in SOS among boys (p < 0.001) and girls (p < 0.01), indicating that children with higher BMI are likely to have lower SOS over time compared to children with lower BMI. For girls, physical activity levels showed positive associations with changes in QUS measures (p < 0.05)., Conclusion: This study documents significant sex differences in the pattern of change in QUS measures over childhood and adolescence. Our study also shows significant influences of adiposity and physical activity on the pattern of change in QUS measures during childhood.
- Published
- 2011
- Full Text
- View/download PDF
14. Rapid infant weight gain and advanced skeletal maturation in childhood.
- Author
-
Demerath EW, Jones LL, Hawley NL, Norris SA, Pettifor JM, Duren D, Chumlea WC, Towne B, and Cameron N
- Subjects
- Adolescent, Age Factors, Birth Weight, Body Mass Index, Body Size, Child, Child, Preschool, Female, Humans, Infant, Infant, Newborn, Longitudinal Studies, Male, South Africa, United States, Young Adult, Bone Development physiology, Weight Gain physiology
- Abstract
Objective: To test the hypothesis that rapid infant weight gain is associated with advanced skeletal maturity in children from the United States and South Africa., Study Design: Longitudinal data from 467 appropriate-for-gestational-age infants in the Fels Longitudinal Growth Study (Dayton, Ohio) and 196 appropriate-for-gestational-age infants in the Birth to Twenty birth cohort study (Johannesburg, South Africa) were used. Multiple linear regression models tested the association between internal SD score change in weight from 0 to 2 years and relative skeletal age at 9 years, adjusting for body mass index, stature, and other covariates., Results: In both studies, faster infant weight gain was associated with more advanced skeletal maturity (approximately 0.2 years or 2.4 months per SD score) at age 9 years (P <.0001-.005), even when adjusting for the positive associations of both birth weight and body mass index at age 9 years. This effect appeared to be accounted for by the greater childhood stature of subjects with more rapid infant weight gain., Conclusions: Relatively rapid infant weight-gain is associated with advanced skeletal development in late childhood, perhaps via effects on stature.
- Published
- 2009
- Full Text
- View/download PDF
15. Sleep disturbance in relation to health-related quality of life in adults: the Fels Longitudinal Study.
- Author
-
Lee M, Choh AC, Demerath EW, Knutson KL, Duren DL, Sherwood RJ, Sun SS, Chumlea WM, Towne B, Siervogel RM, and Czerwinski SA
- Subjects
- Adult, Aged, Cross-Sectional Studies, Data Collection, Female, Humans, Longitudinal Studies, Male, Middle Aged, Odds Ratio, Severity of Illness Index, Surveys and Questionnaires, Activities of Daily Living, Attitude to Health, Fatigue, Mental Health, Quality of Life, Sleep Wake Disorders epidemiology, Sleep Wake Disorders psychology
- Abstract
Objective: Sleep disturbances are prevalent problems in the general population. Symptoms of insomnia can impact various physical and mental conditions. Furthermore, sleep disturbances may worsen the quality of life independently of co-occurring medical conditions. In this study, we examined the relationships between self-reported sleep disturbance symptoms and health-related quality of life measures in the Fels Longitudinal Study., Design: Cross-sectional study., Participants: A total of 397 adults (175 men and 222 women) aged 40 years and older were included in the present study., Measurements: Three self-reported sleep disturbance measures (difficulty falling asleep, nocturnal awakenings and maintaining sleep, and daytime tiredness) were collected between 2003 and 2006. Health-related quality of life measures were assessed using the Medical Outcomes Survey Short Form (SF)-36. Socio-demographic status (marital status, employment status, and education) and current medical conditions were collected from participants during study visits., Results: Individuals who reported frequent sleep disturbances showed significantly worse quality of life on all SF-36 subscales examined. The odds ratio (OR) ranged from 1.71 to 18.32 based on symptoms of insomnia across seven SF-36 domains in analyses adjusted for significant covariates influencing quality of life. Participants with severe sleep disturbances (both sleep problems and daytime impairment) showed generally higher odds of reporting poor SF-36 scores (adjusted ORs; 5.88 - 17.09) compared to participants with no problems., Conclusion: Sleep disturbance is comprehensively and independently associated with poor health-related quality of life in middle-aged and older adults.
- Published
- 2009
- Full Text
- View/download PDF
16. The first seriatim study into old age for weight, stature and BMI: the Fels Longitudinal Study.
- Author
-
Chumlea WC, Choh A, Lee M, Towne B, Sherwood RJ, Duren D, Czerwinski S, and Siervogel RM
- Subjects
- Adolescent, Adult, Aged, Child, Child, Preschool, Female, Humans, Infant, Infant, Newborn, Longitudinal Studies, Male, Middle Aged, Obesity, Overweight, Reference Values, Sex Factors, Body Height, Body Mass Index, Body Weight
- Abstract
Purpose: To document the serial status of measures of weight, stature and BMI from birth into old age., Methods: Longitudinal measures of weight, stature and BMI were taken from birth to 76 years of age for 5 men and 7 women as part of the Fels Longitudinal Study., Results: Sex-specific plots of means for weight, stature and BMI are presented that describe the changes and sex differences in these measurements between birth (or the first year of life) into old age. These serial data demonstrate a continuous increase in body weight through much of adulthood and a small decline in stature starting in late middle age. The plots for BMI indicate the early onset of overweight and subsequent obesity early in adulthood and its continuance into old age for men and women., Conclusions: These are the first plots of serial means for weight, stature and BMI measured from the same group of individuals from birth into old age. These findings demonstrate the changes in these measurements through childhood and maturity into old age. Similar data are needed for individuals from other racial/ethnic groups and countries in order to understand the aging process better.
- Published
- 2009
- Full Text
- View/download PDF
17. Collaborative efforts to improve system response to families who are experiencing child maltreatment and domestic violence.
- Author
-
Banks D, Dutch N, and Wang K
- Subjects
- Adult, Child, Child Abuse prevention & control, Child Health Services standards, Community Networks organization & administration, Female, Health Policy, Humans, Infant, Infant, Newborn, Maternal-Child Health Centers organization & administration, Practice Guidelines as Topic, Pregnancy, Prenatal Care organization & administration, Preventive Health Services standards, Primary Health Care organization & administration, Quality Assurance, Health Care, Socioeconomic Factors, United States, Child Health Services organization & administration, Child Welfare, Community-Institutional Relations, Domestic Violence prevention & control, Health Services Needs and Demand organization & administration, Preventive Health Services organization & administration
- Abstract
The Greenbook demonstration initiative provided federal funding and other support to six communities to establish collaborations to plan and implement policy and practice changes in systems that serve families who are experiencing domestic violence and child maltreatment or child exposure to domestic violence. The demonstration sites established and organized collaborative groups in accordance with the Greenbook foundational principles and recommendations, including representation from multiple levels within the primary partner systems and other organizations, as well as the community. The sites struggled with how to engage consumers of the primary systems, however, and devoted a great deal of time to understanding and addressing organizational differences among the partners. Other salient collaborative influences included leadership, resources, trust, and commitment. The stakeholders noted that the collaborative relationships required a great deal of work but were ultimately one of the main successes of the initiative.
- Published
- 2008
- Full Text
- View/download PDF
18. Changing policy and practice in the child welfare system through collaborative efforts to identify and respond effectively to family violence.
- Author
-
Banks D, Landsverk J, and Wang K
- Subjects
- Adult, Child, Domestic Violence prevention & control, Humans, Patient Education as Topic organization & administration, Practice Guidelines as Topic, Practice Patterns, Physicians', Primary Health Care organization & administration, Quality Assurance, Health Care, Socioeconomic Factors, United States, Child Abuse prevention & control, Child Health Services organization & administration, Child Welfare, Community-Institutional Relations, Health Policy, Health Services Needs and Demand organization & administration, Preventive Health Services organization & administration
- Abstract
The Greenbook provides a roadmap for child welfare agencies to collaborate and provide effective responses to families who are experiencing co-occurring child maltreatment and domestic violence. A multisite developmental evaluation was conducted of six demonstration sites that received federal funding to implement Greenbook recommendations for child welfare agencies. Surveys of child welfare caseworkers show significant changes in several areas of agency policy and practice, including regular domestic violence training, written guidelines for reporting domestic violence, and working closely and sharing resources with local domestic violence service providers. Case file reviews show significant increases in the level of active screening for domestic violence, although this increase peaks at the midpoint of the initiative. These findings, coupled with on-site interview data, point to the importance of coordinating system change activities in child welfare agencies with a number of other collaborative activities.
- Published
- 2008
- Full Text
- View/download PDF
19. Genetic and environmental influences on infant weight and weight change: the Fels Longitudinal Study.
- Author
-
Demerath EW, Choh AC, Czerwinski SA, Lee M, Sun SS, Chumlea WC, Duren D, Sherwood RJ, Blangero J, Towne B, and Siervogel RM
- Subjects
- Age Factors, Birth Weight genetics, Birth Weight physiology, Breast Feeding, Child, Preschool, Family, Female, Humans, Infant, Infant, Newborn, Inheritance Patterns genetics, Longitudinal Studies, Male, Middle Aged, Phenotype, Sex Factors, Body Weight physiology, Environment, Inheritance Patterns physiology
- Abstract
Despite significant progress in understanding the mechanisms by which the prenatal/maternal environment can alter development and adult health, genetic influences on normal variation in growth are little understood. This work examines genetic and nongenetic contributions to body weight and weight change during infancy and the relationships between weight change and adult body composition. The dataset included 501 white infants in 164 nuclear and extended families in the Fels Longitudinal Study, each with 10 serial measures of weight from birth to age 3 years and 232 with body composition data in mid-adulthood. Heritability and covariate effects on weight and weight z-score change from birth to 2 years of age were estimated using a maximum likelihood variance decomposition method. Additive genetic effects explained a high proportion of the variance in infant weight status (h2=0.61-0.95), and change in weight z-score (h2=0.56-0.82). Covariate effects explained 27% of the phenotypic variance at 0-1 month of age and declined in effect to 6.9% of phenotypic variance by 36 months. Significant sex, gestational age, birth order, birth year, and maternal body mass index effects were also identified. For both sexes, a significant increase in weight z-score (>2 SD units) (upward centile crossing) was associated with greater adulthood stature, fat mass, and percent body fat than decrease or stability in weight z-score. Understanding genetic influences on growth rate in a well-nourished, nutritionally stable population may help us interpret the causes and consequences of centile crossing in nutritionally compromised contexts., (Copyright (c) 2007 Wiley-Liss, Inc.)
- Published
- 2007
- Full Text
- View/download PDF
20. Changes in skin blood flow during the menstrual cycle: the influence of the menstrual cycle on the peripheral circulation in healthy female volunteers.
- Author
-
Bartelink ML, Wollersheim H, Theeuwes A, van Duren D, and Thien T
- Subjects
- Adolescent, Adult, Estradiol blood, Female, Follicle Stimulating Hormone blood, Forearm blood supply, Humans, Luteal Phase physiology, Luteinizing Hormone blood, Menstrual Cycle blood, Middle Aged, Progesterone blood, Regional Blood Flow physiology, Skin Temperature physiology, Vascular Resistance physiology, Menstrual Cycle physiology, Skin blood supply
- Abstract
1. It is known that females have a lower skin perfusion than males. In women there are also differences in blood flow at different reproductive stages of their lives. As an initial investigation of the possible contribution of sex hormones to these differences, we studied skin and forearm blood flow during the natural changes in hormone levels which occur during the menstrual cycle. 2. Thirty-one healthy female volunteers were studied. The effect of a standardized finger cooling test (immersion of a gloved hand in a 16 degrees C water bath) on finger skin temperature and on laser Doppler flux in the finger, and forearm blood flow (strain gauge venous occlusion plethysmography) was assessed at four different times during one cycle: during menstruation, 1 day before ovulation, 2 days after ovulation and at the mid-luteal phase. Test days were determined by daily measurements of basal body temperature and were confirmed afterwards by determinations of serum luteinizing hormone, follicle-stimulating hormone, 17 beta-oestradiol and progesterone. 3. Peripheral skin circulation varied significantly within one menstrual cycle. The extremes were a mean finger skin temperature of 25.9 +/- 3.0 degrees C in the luteal phase compared with 28.4 +/- 3.7 degrees C in the pre-ovulatory phase (P = 0.002). The respective values for the mean laser Doppler flux were 18.4 +/- 10.9 compared with 29.2 +/- 16.4 arbitrary units (P = 0.003). 4. Baseline forearm muscle blood flow also varied significantly (P = 0.04) within one menstrual cycle, with low values in the menstrual phase compared with the other phases.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1990
- Full Text
- View/download PDF
21. Importance of sperm motility after capacitation in interpreting the hamster ovum sperm penetration assay.
- Author
-
van Duren DB, Vemer HM, Bastiaans BL, Doesburg WH, Willemsen WN, and Rolland R
- Subjects
- Animals, Cricetinae, Female, Humans, In Vitro Techniques, Male, Sperm Capacitation, Sperm Motility, Sperm-Ovum Interactions
- Abstract
Routine semen analysis and a zona-free hamster ovum sperm penetration assay (SPA) were carried out for 220 men from a group of infertile couples. The grade of sperm motility was determined after a preincubation period. For both the normal and abnormal semen samples, the number of positive SPAs was significantly higher when the postcapacitation motility was normal. This difference was observed also when the routine semen characteristics of density, motility, and morphologic features were considered separately regarding their relationship with the SPA. Motility after preincubation showed the most significant positive correlation with the SPA result. Therefore, the SPA score should be limited to semen samples showing adequate postincubation motility.
- Published
- 1987
- Full Text
- View/download PDF
22. Isolated mitral valve prolapse: chordal architecture as an anatomic basis in older patients.
- Author
-
van der Bel-Kahn J, Duren DR, and Becker AE
- Subjects
- Age Factors, Aged, Female, Heart Valve Diseases pathology, Heart Valve Prosthesis, Humans, Male, Middle Aged, Mitral Valve surgery, Mitral Valve Prolapse surgery, Myocardium pathology, Chordae Tendineae pathology, Mitral Valve pathology, Mitral Valve Prolapse pathology
- Abstract
Ten patients with an average age of 58 years underwent valve replacement because of isolated mitral valve prolapse with severe regurgitation. None had clinical evidence of Marfan's syndrome or another systemic disease that would indicate that a primary connective tissue disorder was the cause of the prolapse. All 10 patients had a dome configuration of the posterior leaflet and one or more ruptured chordae related to it. The gross morphology of the resected specimens revealed marked deviations in chordal branching and the pattern of anchoring in each of the 10 cases, rendering the most severely affected parts of the leaflets less well supported. Similar changes occurred at sites remote from the principal abnormality. Microscopically, the dominant tissue change was myxomatous transformation within the affected leaflets and chordae with secondary changes at both atrial and ventricular surfaces. These findings could indicate that insufficient chordal support may have promoted the development of the floppy valve through a process of chronic undue and unbalanced stress on the valve tension and closure apparatus. The resultant degeneration of the connective tissues, histologically expressed as myxomatous transformation, may underlie stretching and thus redundance of the leaflets and eventually rupture of chordae. It is suggested that this sequence of events be considered as a possible pathogenetic mechanism of isolated mitral valve prolapse, particularly in the subset of aged patients.
- Published
- 1985
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.