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1.
Brain Behav Immun ; 120: 54-70, 2024 May 19.
Article in English | MEDLINE | ID: mdl-38772427

ABSTRACT

Female sex and Apolipoprotein E (APOE) ε4 genotype are top non-modifiable risk factors for Alzheimer's disease (AD). Although female-unique experiences like parity (pregnancy and motherhood) have positive effects on neuroplasticity at middle age, previous pregnancy may also contribute to AD risk. To explore these seemingly paradoxical long-term effects of parity, we investigated the impact of parity with APOEε4 genotype by examining behavioural and neural biomarkers of brain health in middle-aged female rats. Our findings show that primiparous (parous one time) hAPOEε4 rats display increased use of a non-spatial cognitive strategy and exhibit decreased number and recruitment of new-born neurons in the ventral dentate gyrus of the hippocampus in response to spatial working memory retrieval. Furthermore, primiparity and hAPOEε4 genotype synergistically modulate inflammatory markers in the ventral hippocampus. Collectively, these findings demonstrate that previous parity in hAPOEε4 rats confers an added risk to present with reduced activity and engagement of the hippocampus as well as elevated pro-inflammatory signaling, and underscore the importance of considering female-specific factors and genotype in health research.

2.
Medicine (Baltimore) ; 103(1): e36803, 2024 Jan 05.
Article in English | MEDLINE | ID: mdl-38181279

ABSTRACT

Telogen effluvium (TE) is a common cause of hair loss characterized by excessive resting hair shedding. Thyroid dysfunction is one of the possible causes of TE. On the other hand, the link between thyroid disorder and TE is still being debated. The aim of this retrospective is to investigate the link between thyroid dysfunction and TE. This retrospective study included 500 female patients with TE who had thyroid function testing between January 2012 and December 2022. Patients were eligible if they had a confirmed TE diagnosis and thyroid function tests within 3 months of being diagnosed with TE. The thyroid function of the participants was classified as euthyroid, hypothyroidism, or hyperthyroidism. The severity of hair loss was determined using the severity of alopecia tool (SALT) score. The study included 500 TE females, 248 of whom were euthyroid, 150 had hypothyroidism, and 102 had hyperthyroidism. The hypothyroid group had a significantly higher mean SALT score than the other 2 groups. Furthermore, patients in the hypothyroid group had a higher proportion of severe hair loss. The mean SALT score did not differ significantly between groups with normal thyroid function and those with hyperthyroidism. A common cause of TE is thyroid dysfunction, particularly hypothyroidism. Patients with hypothyroidism have more severe hair loss than those with normal thyroid function or hyperthyroidism. To effectively identify and manage such cases, thyroid function testing should be included in the diagnostic workup of patients with TE.


Subject(s)
Alopecia Areata , Hyperthyroidism , Hypothyroidism , Thyroid Diseases , Humans , Female , Retrospective Studies , Thyroid Diseases/complications , Thyroid Diseases/epidemiology , Hypothyroidism/complications , Hypothyroidism/epidemiology , Hyperthyroidism/complications
3.
Psychol Med ; : 1-10, 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38087866

ABSTRACT

BACKGROUND: Maternal anxiety, depression, and stress during and after pregnancy are negatively associated with child cognitive development. However, the contribution of positive maternal experiences, such as social support, to child cognitive development has received less attention. Furthermore, how maternal experience of social support during specific developmental periods impacts child cognitive development is largely unknown. METHODS: Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC; n = 5784) and the Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction study (PREDO; n = 420), we investigated the associations between maternal perceived social support during and after pregnancy and child's general cognitive ability at 8 years of age, assessed with the Wechsler Intelligence Scale for Children (WISC). Bayesian relevant life course modeling was used to investigate timing effects of maternal social support on child cognitive ability. RESULTS: In both cohorts, higher maternal perceived social support during pregnancy was associated with higher performance on the WISC, independent of sociodemographic factors and concurrent maternal symptoms of depression and anxiety. In ALSPAC, pregnancy emerged as a sensitive period for the effects of perceived social support on child cognitive ability, with a stronger effect of social support during pregnancy than after pregnancy on child cognitive ability. CONCLUSIONS: Our findings, supported from two prospective longitudinal cohorts, suggest a distinct role of maternal perceived social support during pregnancy for cognitive development in children. Our study suggests that interventions aimed at increasing maternal social support during pregnancy may be an important strategy for promoting maternal and child well-being.

4.
Opt Lett ; 48(24): 6541-6544, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-38099794

ABSTRACT

We report on a mode-mismatched thermal lens experiment performed to quantitatively evaluate thermal and electronic laser-induced lensing effects in ion-doped crystals Cr3+:LiSAF, Yb3+:KYW, and Yb3+:YAG. The large diameter of the probe beam resulted in a slow thermal effect (∼dozens of milliseconds) two orders of magnitude larger than the electronic one, improving the discrimination of both competitive effects. All thermal and electronic parameters are obtained from transient signals modeled by an analytical equation, valid for small phase shifts in the absence of upconversion effects.

5.
Brain Behav Immun ; 97: 394-409, 2021 10.
Article in English | MEDLINE | ID: mdl-34174336

ABSTRACT

Untreated perinatal depression can have severe consequences for the mother and her children. However, both the efficacy to mothers and safety to exposed infants of pharmacological antidepressants such as selective serotonin reuptake inhibitors (SSRIs), have been questioned. We previously reported that maternal SSRI exposure increased hippocampal IL-1ß levels, which may be tied to limited efficacy of SSRIs during the postpartum to the dam but is not yet known whether maternal postpartum SSRIs affect the neuroinflammatory profile of adult offspring. In addition, although controversial, perinatal SSRI exposure has been linked to increased risk of autism spectrum disorder (ASD) in children. Oxytocin (OT) is under investigation as a treatment for ASD, but OT is a large neuropeptide that has difficulty crossing the blood-brain barrier (BBB). TriozanTM is a nanoformulation that can facilitate OT to cross the BBB. Thus, we investigated the impact of maternal postpartum SSRIs and offspring preadolescent OT treatment on adult offspring neuroinflammation, social behavior, and neurogenesis in the hippocampus. Using a model of de novo postpartum depression, corticosterone (CORT) was given in the postpartum to the dam with or without treatment with the SSRI, fluoxetine (FLX) for 21 days postpartum. Offspring were then subsequently treated with either OT, OT + TriozanTM, or vehicle for 10 days prior to adolescence (PD25-34). Maternal FLX decreased hippocampal IL-10 and IL-13 and neurogenesis in both sexes, whereas maternal CORT increased hippocampal IL-13 in both sexes. Maternal CORT treatment shifted the neuroimmune profile towards a more proinflammatory profile in offspring hippocampus, whereas oxytocin, independent of formulation, normalized this profile. OT treatment increased hippocampal neurogenesis in adult males but not in adult females, regardless of maternal treatment. OT treatment increased the time spent with a novel social stimulus animal (social investigation) in both adult male and female offspring, although this effect depended on maternal CORT. These findings underscore that preadolescent exposure to OT can reverse some of the long-lasting effects of postpartum maternal CORT and FLX treatments in the adult offspring. In addition, we found that maternal treatments that reduce (CORT) or increase (FLX) hippocampal inflammation in dams resulted in opposing patterns of hippocampal inflammation in adult offspring.


Subject(s)
Autism Spectrum Disorder , Prenatal Exposure Delayed Effects , Adult Children , Animals , Autism Spectrum Disorder/drug therapy , Doublecortin Protein , Female , Fluoxetine/pharmacology , Hippocampus , Humans , Inflammation/drug therapy , Male , Neurogenesis , Oxytocin , Pregnancy , Rats , Rats, Sprague-Dawley , Selective Serotonin Reuptake Inhibitors/pharmacology , Stress, Psychological
6.
Neuropharmacology ; 175: 108174, 2020 09 15.
Article in English | MEDLINE | ID: mdl-32497592

ABSTRACT

Perinatal depression (PND) affects approximately 15% of women, and de novo postpartum depression affects approximately 40% of PND cases. Selective serotonin reuptake inhibitors (SSRIs) are a common class of antidepressants prescribed to treat PND. However, the safety and efficacy of SSRIs have been questioned in both clinical and preclinical research. Here, using a preclinical rodent model of de novo postpartum depression, we aim to better understand neuroinflammatory cytokines and tryptophan mechanisms that may be related to SSRI efficacy. Rat dams were treated with high corticosterone (CORT; 40 mg/kg, s.c.) for 22 days in the postpartum period to simulate a depressive-like endophenotype. Concurrently, a subset of dams was treated with the SSRI, fluoxetine (FLX; 10 mg/kg, s.c.), in the postpartum period. We showed, consistent with previous studies, that although maternal FLX treatment prevented CORT-induced disturbances in maternal care behavior during the early postpartum, it failed to prevent the expression of CORT-induced passive coping behavior in the late postpartum. Furthermore, FLX treatment, regardless of CORT treatment, increased maternal hippocampal IL-1ß, plasma CXCL1, and decreased maternal plasma tryptophan, 4'-pyridoxic acid, and pyridoxal concentrations. Maternal CORT treatment reduced maternal hippocampal IFN-γ, and both hippocampal and plasma TNF-α. Our work suggests that the limited efficacy of FLX in the late postpartum may be associated with elevated levels of the proinflammatory cytokine IL-1ß in the maternal hippocampus, elevated plasma CXCL1, decreased plasma tryptophan concentration, and changes in vitamin B6 dependent tryptophan-kynurenine pathway. These findings suggest novel pathways for improving SSRI efficacy in alleviating perinatal depression.


Subject(s)
Depression, Postpartum/metabolism , Fluoxetine/administration & dosage , Inflammation Mediators/metabolism , Selective Serotonin Reuptake Inhibitors/administration & dosage , Signal Transduction/drug effects , Tryptophan/metabolism , Animals , Disease Models, Animal , Female , Frontal Lobe/drug effects , Frontal Lobe/metabolism , Hippocampus/drug effects , Hippocampus/metabolism , Postpartum Period , Rats, Sprague-Dawley
7.
Neurobiol Stress ; 12: 100199, 2020 May.
Article in English | MEDLINE | ID: mdl-31871960

ABSTRACT

Ovarian hormones influence the outcomes of stress exposure and are implicated in stress-related disorders including depression, yet their roles are often complex and seemingly contradictory. Importantly, depression and stress exposure are associated with immune dysregulation, and ovarian hormones have immunomodulatory properties. However, how ovarian hormones can influence the inflammatory outcomes of stress exposure is poorly understood. Here, we examined the effects of long-term ovariectomy on the behavioral and neuroinflammatory outcomes of sub-chronic stress exposure in middle-aged mice. Briefly, sham-operated and ovariectomized mice were assigned to non-stress groups or exposed to 6 days of variable stress. Mice were assessed on a battery of behavioral tests, and cytokine concentrations were quantified in the frontal cortex and hippocampus. In the frontal cortex, postsynaptic density protein-95 expression was examined as an index of excitatory synapse number and/or stability, and phosphorylated mitogen-activated protein kinases (MAPKs) were measured to explore potential cell signaling pathways elicited by stress exposure and/or ovarian hormones. Long-term ovariectomy modified the central cytokine profile by robustly reducing cytokine concentrations in the frontal cortex and modestly increasing concentrations in the hippocampus. Under non-stress conditions, long-term ovariectomy also reduced extracellular signal-regulated kinase (ERK) phosphoprotein expression in the frontal cortex and increased some measures of depressive-like behavior. The effects of sub-chronic stress exposure were however more pronounced in sham-operated mice. Notably, in sham-operated mice only, sub-chronic stress exposure increased IL-1ß and IL-6:IL-10 ratio in the frontal cortex and hippocampus and reduced pERK1/2 expression in the frontal cortex. Further, although sub-chronic stress exposure increased anhedonia-like behavior regardless of ovarian status, it increased passive-coping behavior in sham-operated mice only. These data indicate that long-term ovariectomy has potent effects on the central cytokine milieu and dictates the neuroinflammatory and behavioral effects of sub-chronic stress exposure in middle-aged mice. These findings therefore suggest that the immunomodulatory properties of ovarian hormones are of relevance in the context of stress and possibly depression.

8.
Horm Behav ; 119: 104651, 2020 03.
Article in English | MEDLINE | ID: mdl-31790664

ABSTRACT

The estrogen receptor (ER) mechanisms by which 17ß-estradiol influences depressive-like behaviour have primarily been investigated acutely and not within an animal model of depression. Therefore, the current study aimed to dissect the contribution of ERα and ERß to the effects of 17ß-estradiol under non-stress and chronic stress conditions. Ovariectomized (OVX) or sham-operated mice were treated chronically (47 days) with 17ß-estradiol (E2), the ERß agonist diarylpropionitrile (DPN), the ERα agonist propylpyrazole-triol (PPT), or vehicle. On day 15 of treatment, mice from each group were assigned to chronic unpredictable stress (CUS; 28 days) or non-CUS conditions. Mice were assessed for anxiety- and depressive-like behaviour and hypothalamic-pituitary-adrenal (HPA) axis function. Cytokine and chemokine levels, and postsynaptic density protein 95 were measured in the hippocampus and frontal cortex, and adult hippocampal neurogenesis was assessed. Overall, the effects of CUS were more robust that those of estrogenic treatments, as seen by increased immobility in the tail suspension test (TST), reduced PSD-95 expression, reduced neurogenesis in the ventral hippocampus, and HPA axis negative feedback dysregulation. However, we also observe CUS-dependent and -independent effects of ovarian status and estrogenic treatments. The effects of CUS on PSD-95 expression, the cytokine milieu, and in TST were largely driven by PPT and DPN, indicating that these treatments were not protective. Independent of CUS, estradiol increased neurogenesis in the dorsal hippocampus, blunted the corticosterone response to an acute stressor, and increased anxiety-like behaviour. These findings provide insights into the complexities of estrogen signaling in modulating depressive-like phenotypes under non-stress and chronic stress conditions.


Subject(s)
Depression/metabolism , Estrogen Receptor alpha/agonists , Estrogen Receptor beta/agonists , Stress, Psychological/metabolism , Animals , Chronic Disease , Corticosterone/metabolism , Depression/etiology , Depression/psychology , Estradiol/pharmacology , Estrogen Receptor alpha/metabolism , Estrogen Receptor beta/metabolism , Female , Freezing Reaction, Cataleptic/drug effects , Freezing Reaction, Cataleptic/physiology , Hippocampus/drug effects , Hypothalamo-Hypophyseal System/drug effects , Hypothalamo-Hypophyseal System/metabolism , Mice , Mice, Inbred C57BL , Nitriles/pharmacology , Ovariectomy , Phenols/pharmacology , Phenotype , Pituitary-Adrenal System/drug effects , Pituitary-Adrenal System/metabolism , Propionates/pharmacology , Pyrazoles/pharmacology , Stress, Psychological/complications , Stress, Psychological/pathology , Stress, Psychological/psychology
9.
AJNR Am J Neuroradiol ; 40(7): 1132-1139, 2019 07.
Article in English | MEDLINE | ID: mdl-31248863

ABSTRACT

BACKGROUND AND PURPOSE: Brain tumor clinical trials requiring solid tumor assessment typically rely on the 2D manual delineation of enhancing tumors by ≥2 expert readers, a time-consuming step with poor interreader agreement. As a solution, we developed quantitative dT1 maps for the delineation of enhancing lesions. This retrospective analysis compares dT1 with 2D manual delineation of enhancing tumors acquired at 2 time points during the post therapeutic surveillance period of the American College of Radiology Imaging Network 6677/Radiation Therapy Oncology Group 0625 (ACRIN 6677/RTOG 0625) clinical trial. MATERIALS AND METHODS: Patients enrolled in ACRIN 6677/RTOG 0625, a multicenter, randomized Phase II trial of bevacizumab in recurrent glioblastoma, underwent standard MR imaging before and after treatment initiation. For 123 patients from 23 institutions, both 2D manual delineation of enhancing tumors and dT1 datasets were evaluable at weeks 8 (n = 74) and 16 (n = 57). Using dT1, we assessed the radiologic response and progression at each time point. Percentage agreement with adjudicated 2D manual delineation of enhancing tumor reads and association between progression status and overall survival were determined. RESULTS: For identification of progression, dT1 and adjudicated 2D manual delineation of enhancing tumor reads were in perfect agreement at week 8, with 73.7% agreement at week 16. Both methods showed significant differences in overall survival at each time point. When nonprogressors were further divided into responders versus nonresponders/nonprogressors, the agreement decreased to 70.3% and 52.6%, yet dT1 showed a significant difference in overall survival at week 8 (P = .01), suggesting that dT1 may provide greater sensitivity for stratifying subpopulations. CONCLUSIONS: This study shows that dT1 can predict early progression comparable with the standard method but offers the potential for substantial time and cost savings for clinical trials.


Subject(s)
Brain Neoplasms/diagnostic imaging , Glioblastoma/diagnostic imaging , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Neuroimaging/methods , Adult , Aged , Antineoplastic Agents, Immunological/therapeutic use , Bevacizumab/therapeutic use , Brain Neoplasms/drug therapy , Brain Neoplasms/pathology , Female , Glioblastoma/drug therapy , Glioblastoma/pathology , Humans , Male , Middle Aged , Retrospective Studies , Tumor Burden
10.
AJNR Am J Neuroradiol ; 40(4): 626-633, 2019 04.
Article in English | MEDLINE | ID: mdl-30923088

ABSTRACT

BACKGROUND AND PURPOSE: DSC-MR imaging using preload, intermediate (60°) flip angle and postprocessing leakage correction has gained traction as a standard methodology. Simulations suggest that DSC-MR imaging with flip angle = 30° and no preload yields relative CBV practically equivalent to the reference standard. This study tested this hypothesis in vivo. MATERIALS AND METHODS: Eighty-four patients with brain lesions were enrolled in this 3-institution study. Forty-three patients satisfied the inclusion criteria. DSC-MR imaging (3T, single-dose gadobutrol, gradient recalled-echo-EPI, TE = 20-35 ms, TR = 1.2-1.63 seconds) was performed twice for each patient, with flip angle = 30°-35° and no preload (P-), which provided preload (P+) for the subsequent intermediate flip angle = 60°. Normalized relative CBV and standardized relative CBV maps were generated, including postprocessing with contrast agent leakage correction (C+) and without (C-) contrast agent leakage correction. Contrast-enhancing lesion volume, mean relative CBV, and contrast-to-noise ratio obtained with 30°/P-/C-, 30°/P-/C+, and 60°/P+/C- were compared with 60°/P+/C+ using the Lin concordance correlation coefficient and Bland-Altman analysis. Equivalence between the 30°/P-/C+ and 60°/P+/C+ protocols and the temporal SNR for the 30°/P- and 60°/P+ DSC-MR imaging data was also determined. RESULTS: Compared with 60°/P+/C+, 30°/P-/C+ had closest mean standardized relative CBV (P = .61), highest Lin concordance correlation coefficient (0.96), and lowest Bland-Altman bias (µ = 1.89), compared with 30°/P-/C- (P = .02, Lin concordance correlation coefficient = 0.59, µ = 14.6) and 60°/P+/C- (P = .03, Lin concordance correlation coefficient = 0.88, µ = -10.1) with no statistical difference in contrast-to-noise ratios across protocols. The normalized relative CBV and standardized relative CBV were statistically equivalent at the 10% level using either the 30°/P-/C+ or 60°/P+/C+ protocols. Temporal SNR was not significantly different for 30°/P- and 60°/P+ (P = .06). CONCLUSIONS: Tumor relative CBV derived from low-flip angle, no-preload DSC-MR imaging with leakage correction is an attractive single-dose alternative to the higher dose reference standard.


Subject(s)
Brain Neoplasms/diagnostic imaging , Image Interpretation, Computer-Assisted/standards , Magnetic Resonance Imaging/standards , Neuroimaging/standards , Adult , Brain Neoplasms/pathology , Consensus , Contrast Media , Female , Humans , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Male , Neuroimaging/methods , Organometallic Compounds , Reference Standards
11.
Neurobiol Aging ; 78: 1-17, 2019 06.
Article in English | MEDLINE | ID: mdl-30825663

ABSTRACT

The maternal brain displays considerable plasticity, and motherhood is associated with changes in affective and cognitive function. Motherhood can alter the trajectory of brain aging, including modifications to neuroplasticity and cognition. Here, we investigated the short- and long-term effects of motherhood on hippocampal neurogenesis, microglial density and morphology, and circulating cytokines, domains known to be altered with age and implicated in cognition and mood. Female rats were bred then euthanized during gestation or at various postpartum time points, culminating in middle age, and nulliparous rats served as age-matched controls. Hippocampal neurogenesis was significantly suppressed during gestation and the postpartum period. Interestingly, neurogenesis declined significantly in middle-aged nulliparous rats but increased in primiparous rats across the same period. Transient postpartum adaptations to the neuroimmune environment of the hippocampus were evidenced, as Iba-1-immunoreactive microglia assumed a deramified morphology followed by increased density. Intriguingly, aging-related changes in circulating cytokines were dependent on parity. These adaptations in neurogenic and immune processes may have ramifications for maternal mood and cognition across the peripartum period and beyond.


Subject(s)
Aging , Cytokines/metabolism , Hippocampus/physiology , Microglia/physiology , Mothers , Neurogenesis/physiology , Affect , Aging/immunology , Aging/metabolism , Aging/pathology , Aging/physiology , Animals , Calcium-Binding Proteins , Cell Count , Cognition , Doublecortin Domain Proteins , Doublecortin Protein , Female , Hippocampus/immunology , Humans , Male , Microfilament Proteins , Microglia/pathology , Microtubule-Associated Proteins , Mothers/psychology , Neuroimmunomodulation , Neuropeptides , Postpartum Period/physiology , Postpartum Period/psychology , Pregnancy , Rats, Sprague-Dawley
12.
Prog Neurobiol ; 176: 86-102, 2019 05.
Article in English | MEDLINE | ID: mdl-30721749

ABSTRACT

Depression represents a global mental health concern, and disproportionally affects women as they are twice more likely to be diagnosed than men. In this review, we provide a summary of evidence to support the notion that differences in depression between men and women span multiple facets of the disease, including epidemiology, symptomology, treatment, and pathophysiology. Through a lens of biological sex, we overview depression-related transcriptional patterns, changes in neuroanatomy and neuroplasticity, and immune signatures. We acknowledge the unique physiological and behavioral demands of pregnancy and motherhood by devoting special attention to depression occurring in the peripartum period. Specifically, we discuss issues surrounding the presentation, time course, treatment, and neurobiology of peripartum depression. We write this review with the intention of highlighting the encouraging advancements in our understanding of sex differences in depression, while underscoring the gaps that remain. A more systematic consideration of biological sex as a variable in depression research will be critical in the discovery and development of pharmacotherapies that are efficacious for both men and women.


Subject(s)
Depression , Sex Characteristics , Animals , Female , Humans , Male
13.
Ir Med J ; 111(2): 694, 2018 Feb 09.
Article in English | MEDLINE | ID: mdl-29952443

ABSTRACT

Correct technique with inhalers is vital for therapeutic effect. Efficacy of DVD inhaler instruction was investigated. Secondary aims were to examine feasibility of an inhaler technique outcome measure, and to compare knowledge and self-efficacy after DVD or individual education. This was a randomised controlled trial conducted in a regional hospital paediatric ward, involving new or existing paediatric inhaler users. Inhaler technique was assessed pre-education in existing inhaler users. Participants were then randomised to message equivalent education by DVD or individually with a physiotherapist. Inhaler technique, self-efficacy and knowledge were assessed immediately post- and three months after education. Twenty one participants received DVD or individual education. There were no significant differences between groups for technique, self-efficacy or knowledge at any time. The outcome measure was feasible for use in a research study. DVD education was equivalent to individual instruction to teach parents how to use inhalers with their child.


Subject(s)
Nebulizers and Vaporizers , Patient Education as Topic , Physical Therapists , Video Recording , Child , Feasibility Studies , Humans
14.
AJNR Am J Neuroradiol ; 39(6): 1008-1016, 2018 06.
Article in English | MEDLINE | ID: mdl-29794239

ABSTRACT

BACKGROUND AND PURPOSE: Standard assessment criteria for brain tumors that only include anatomic imaging continue to be insufficient. While numerous studies have demonstrated the value of DSC-MR imaging perfusion metrics for this purpose, they have not been incorporated due to a lack of confidence in the consistency of DSC-MR imaging metrics across sites and platforms. This study addresses this limitation with a comparison of multisite/multiplatform analyses of shared DSC-MR imaging datasets of patients with brain tumors. MATERIALS AND METHODS: DSC-MR imaging data were collected after a preload and during a bolus injection of gadolinium contrast agent using a gradient recalled-echo-EPI sequence (TE/TR = 30/1200 ms; flip angle = 72°). Forty-nine low-grade (n = 13) and high-grade (n = 36) glioma datasets were uploaded to The Cancer Imaging Archive. Datasets included a predetermined arterial input function, enhancing tumor ROIs, and ROIs necessary to create normalized relative CBV and CBF maps. Seven sites computed 20 different perfusion metrics. Pair-wise agreement among sites was assessed with the Lin concordance correlation coefficient. Distinction of low- from high-grade tumors was evaluated with the Wilcoxon rank sum test followed by receiver operating characteristic analysis to identify the optimal thresholds based on sensitivity and specificity. RESULTS: For normalized relative CBV and normalized CBF, 93% and 94% of entries showed good or excellent cross-site agreement (0.8 ≤ Lin concordance correlation coefficient ≤ 1.0). All metrics could distinguish low- from high-grade tumors. Optimum thresholds were determined for pooled data (normalized relative CBV = 1.4, sensitivity/specificity = 90%:77%; normalized CBF = 1.58, sensitivity/specificity = 86%:77%). CONCLUSIONS: By means of DSC-MR imaging data obtained after a preload of contrast agent, substantial consistency resulted across sites for brain tumor perfusion metrics with a common threshold discoverable for distinguishing low- from high-grade tumors.


Subject(s)
Brain Neoplasms/diagnostic imaging , Datasets as Topic/standards , Glioma/diagnostic imaging , Image Interpretation, Computer-Assisted/standards , Magnetic Resonance Imaging/standards , Adult , Aged , Algorithms , Brain Neoplasms/pathology , Female , Glioma/pathology , Humans , Image Interpretation, Computer-Assisted/methods , Male , Middle Aged , National Cancer Institute (U.S.) , United States
15.
Appl Opt ; 57(2): 362-370, 2018 Jan 10.
Article in English | MEDLINE | ID: mdl-29328186

ABSTRACT

Erbium-doped yttrium aluminum garnet (Er3+:YAG) rods were inserted inside undoped tubes and grown into single-crystal fibers of a diameter of 300 µm using the laser-heated pedestal growth technique. Growth at various rates resulted in radially graded distributions of Er3+ dopant ions, as observed using laser-induced fluorescence imaging. Profiles of the refractive index were measured using cross-sectional reflectometry in a microscope. Dopant distributions and the corresponding index profiles were compared with thermal diffusion theory to determine the inter-diffusion coefficient of Y3+ and Er3+ ions at 2000°C, yielding an estimated value of D=(9.10±0.8)×10-11 m2/s. This work constitutes a step toward controlled growth of fibers with high thermal conductivities, low Brillouin gain, and waveguiding properties required for high-power optical amplifier and laser applications.

16.
Opt Express ; 24(18): 20755-62, 2016 Sep 05.
Article in English | MEDLINE | ID: mdl-27607678

ABSTRACT

A new method of steering THz pulses radiated from a thin emitter excited by tilted optical pulse-fronts has been developed theoretically and validated in a proof-of-concept experiment. This steering technique is potentially efficient and rapid, and it should benefit from a THz-pulse energy that can scale with optical-beam size and magnitude. Conversely, the method employed for measuring the steered THz pulses is also capable of characterizing the pulse-front tilt of an optical beam.

17.
AJNR Am J Neuroradiol ; 37(12): 2201-2208, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27492073

ABSTRACT

BACKGROUND AND PURPOSE: Patients with recurrent glioblastoma often exhibit regions of diffusion restriction following the initiation of bevacizumab therapy. Studies suggest that these regions represent either diffusion-restricted necrosis or hypercellular tumor. This study explored postmortem brain specimens and a population analysis of overall survival to determine the identity and implications of such lesions. MATERIALS AND METHODS: Postmortem examinations were performed on 6 patients with recurrent glioblastoma on bevacizumab with progressively growing regions of diffusion restriction. ADC values were extracted from regions of both hypercellular tumor and necrosis. A receiver operating characteristic analysis was performed to define optimal ADC thresholds for differentiating tissue types. A retrospective population study was also performed comparing the overall survival of 64 patients with recurrent glioblastoma treated with bevacizumab. Patients were separated into 3 groups: no diffusion restriction, diffusion restriction that appeared and progressed within 5 months of bevacizumab initiation, and delayed or stable diffusion restriction. An additional analysis was performed assessing tumor O6-methylguanine-DNA-methyltransferase methylation. RESULTS: The optimal ADC threshold for differentiation of hypercellularity and necrosis was 0.736 × 10-3mm2/s. Progressively expanding diffusion restriction was pathologically confirmed to be coagulative necrosis surrounded by viable tumor. Progressive lesions were associated with the worst overall survival, while stable lesions showed the greatest overall survival (P < .05). Of the 40% of patients with O6-methylguanine-DNA-methyltransferase methylated tumors, none developed diffusion-restricted lesions. CONCLUSIONS: Progressive diffusion-restricted lesions were pathologically confirmed to be coagulative necrosis surrounded by viable tumor and associated with decreased overall survival. Stable lesions were, however, associated with increased overall survival. All lesions were associated with O6-methylguanine-DNA-methyltransferase unmethylated tumors.


Subject(s)
Brain Neoplasms/pathology , Glioblastoma/pathology , Neoplasm Recurrence, Local/pathology , Adult , Aged , Antineoplastic Agents/therapeutic use , Bevacizumab/therapeutic use , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/drug therapy , Diffusion Magnetic Resonance Imaging/methods , Female , Glioblastoma/diagnostic imaging , Glioblastoma/drug therapy , Humans , Male , Middle Aged , Necrosis/diagnostic imaging , Necrosis/pathology , Neoplasm Recurrence, Local/diagnostic imaging , Neoplasm Recurrence, Local/mortality , Retrospective Studies
18.
Lasers Med Sci ; 31(5): 1027-35, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26984345

ABSTRACT

Primary cutaneous amyloidosis (PCA) is a condition characterized by tissue deposition of misfolded proteins. PCA can present in different forms, namely macular, lichen, and nodular amyloidosis. These lesions can be of cosmetic concern and are difficult to treat. Many therapeutic modalities have been suggested for the treatment of PCA, with variable efficacy, including topical and systemic medications, phototherapy, electrodessication, dermabrasion, cryosurgery, and lasers. Over the past decade, several studies have reported successful treatment of PCA with different types of lasers; however, a review of these studies has never been reported in the dermatologic literature. The aim of this study was to review the efficacy and safety of lasers in the treatment of PCA. A search of the National Library of Medicine's PubMed Database was performed. Studies were considered for inclusion based on their relevance, and specific data were extracted from all included studies. Eleven studies, comprising 64 patients, were included in this review. Significant improvements were observed in macular and lichen amyloidosis patients treated with carbon dioxide laser in two studies, while a number of case series and case reports showed good results with other types of laser in the treatment of PCA. This review was limited by the lack of large double-blinded randomized controlled trials and the overall small sample size. Laser treatment is a promising option in the treatment of PCA. Future randomized controlled trials are needed to compare the efficacy of different types of lasers and to select the best parameters for different types of PCA.


Subject(s)
Amyloidosis, Familial/radiotherapy , Low-Level Light Therapy/methods , Skin Diseases, Genetic/radiotherapy , Female , Humans , Lasers, Gas/therapeutic use , Male , United States
19.
Opt Express ; 22(3): 2910-24, 2014 Feb 10.
Article in English | MEDLINE | ID: mdl-24663583

ABSTRACT

The state mixings necessary to mediate three new optical nonlinearities are shown to arise simultaneously and automatically in a 2-level atom with an ℓ = 0 ground state and an ℓ = 1 excited state that undergoes a sequence of electric and magnetic dipole-allowed transitions. The treatment is based on an extension of dressed state theory that includes quantized electric and magnetic field interactions. Magneto-electric rectification, transverse magnetization, and second-harmonic generation are shown to constitute a family of nonlinear effects that can take place regardless of whether inversion is a symmetry of the initial unperturbed system or not. Interactions driven jointly by the optical electric and magnetic fields produce dynamic symmetry-breaking that accounts for the frequency, the intensity dependence, and the polarization of induced magnetization in prior experiments. This strong field quantum model explains not only how a driven 2-level system may develop nonlinear dipole moments that are forbidden between or within its stationary states, but it also broadens the class of materials suitable for optical energy conversion applications and magnetic field generation with light so as to include all transparent dielectrics.

20.
Paediatr Respir Rev ; 14(4): 263-9, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24209461

ABSTRACT

Optimisation of physiotherapy techniques to improve outcomes is an area of cystic fibrosis (CF) care, which has developed considerably over the last two decades. With the introduction of newborn screening and an increase in median life expectancy, the management of individuals with CF has needed to adapt to a more dynamic and individualised approach. It is essential that CF physiotherapy management reflects the needs of a changing cohort of paediatric CF patients and it is no longer justifiable to adopt a 'blanket' prescriptive approach to care. The areas of physiotherapy management which are reviewed and discussed in this paper include inhalation therapy, airway clearance techniques, the management of newborn screened infants, physical activity and exercise.


Subject(s)
Cystic Fibrosis/therapy , Neonatal Screening/methods , Respiratory Therapy/methods , Cystic Fibrosis/diagnosis , Cystic Fibrosis/epidemiology , Global Health , Humans , Incidence , Infant, Newborn , Physical Therapy Modalities/trends , Respiratory Function Tests
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