Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
1.
Anaesth Rep ; 12(1): e12305, 2024.
Article in English | MEDLINE | ID: mdl-38887533

ABSTRACT

The National Tracheostomy Safety Project has run high-quality, face-to-face skills courses since 2009. The aim of this project was to produce a virtual reality version of the established course and evaluate its impact on participant learning, and participant and faculty satisfaction. Healthcare staff and students were recruited and randomised to attend one of (1) a face-to-face traditional course (control); (2) a virtual reality course at a conference centre with on-site technical support; (3) a fully remote virtual reality course; the virtual reality groups were combined for the analysis of learning outcomes and satisfaction. The primary outcome was the difference in pre/post-course knowledge scores on a 30-item questionnaire; secondary outcomes included knowledge retention, usability, comfort/side effects and participant performance in a simulated tracheostomy emergency. Thirty-seven participants and 15 faculty participated in this study. There was no significant difference between mean pre/post-course scores from the face-to-face (from 21.1 to 23.1; +2) and combined virtual reality (from 17.1 to 21.1; +4) groups, with both showing improvement (p = 0.21). The mean System Usability Scale score for virtual reality was 76.8 (SD 12.6), which is above average; the median Simulator Sickness Questionnaire score was 7.5 (IQR 3.7-22.4), indicating minimal symptoms. All participants resolved the primary clinical problem in the simulated emergency, but the virtual reality (VR) group was slower overall (mean difference 61.8 s, p = 0.003). This technical feasibility study demonstrated that there was no difference in participant knowledge immediately after and 4 weeks following face-to-face and virtual reality courses. Virtual reality offers an immersive experience that can be delivered remotely and offers potential benefits of reducing travel and venue costs for attendees, therefore increasing the flexibility of training opportunities.

2.
Nat Neurosci ; 24(8): 1176-1186, 2021 08.
Article in English | MEDLINE | ID: mdl-34099922

ABSTRACT

The Adolescent Brain Cognitive Development (ABCD) Study® is a 10-year longitudinal study of children recruited at ages 9 and 10. A battery of neuroimaging tasks are administered biennially to track neurodevelopment and identify individual differences in brain function. This study reports activation patterns from functional MRI (fMRI) tasks completed at baseline, which were designed to measure cognitive impulse control with a stop signal task (SST; N = 5,547), reward anticipation and receipt with a monetary incentive delay (MID) task (N = 6,657) and working memory and emotion reactivity with an emotional N-back (EN-back) task (N = 6,009). Further, we report the spatial reproducibility of activation patterns by assessing between-group vertex/voxelwise correlations of blood oxygen level-dependent (BOLD) activation. Analyses reveal robust brain activations that are consistent with the published literature, vary across fMRI tasks/contrasts and slightly correlate with individual behavioral performance on the tasks. These results establish the preadolescent brain function baseline, guide interpretation of cross-sectional analyses and will enable the investigation of longitudinal changes during adolescent development.


Subject(s)
Brain/physiology , Adolescent , Adolescent Development/physiology , Child , Female , Humans , Magnetic Resonance Imaging , Male , Reference Values
5.
Mol Psychiatry ; 23(5): 1261-1269, 2018 05.
Article in English | MEDLINE | ID: mdl-29038599

ABSTRACT

The regional distribution of white matter (WM) abnormalities in schizophrenia remains poorly understood, and reported disease effects on the brain vary widely between studies. In an effort to identify commonalities across studies, we perform what we believe is the first ever large-scale coordinated study of WM microstructural differences in schizophrenia. Our analysis consisted of 2359 healthy controls and 1963 schizophrenia patients from 29 independent international studies; we harmonized the processing and statistical analyses of diffusion tensor imaging (DTI) data across sites and meta-analyzed effects across studies. Significant reductions in fractional anisotropy (FA) in schizophrenia patients were widespread, and detected in 20 of 25 regions of interest within a WM skeleton representing all major WM fasciculi. Effect sizes varied by region, peaking at (d=0.42) for the entire WM skeleton, driven more by peripheral areas as opposed to the core WM where regions of interest were defined. The anterior corona radiata (d=0.40) and corpus callosum (d=0.39), specifically its body (d=0.39) and genu (d=0.37), showed greatest effects. Significant decreases, to lesser degrees, were observed in almost all regions analyzed. Larger effect sizes were observed for FA than diffusivity measures; significantly higher mean and radial diffusivity was observed for schizophrenia patients compared with controls. No significant effects of age at onset of schizophrenia or medication dosage were detected. As the largest coordinated analysis of WM differences in a psychiatric disorder to date, the present study provides a robust profile of widespread WM abnormalities in schizophrenia patients worldwide. Interactive three-dimensional visualization of the results is available at www.enigma-viewer.org.


Subject(s)
Schizophrenia/diagnostic imaging , Schizophrenia/physiopathology , White Matter/ultrastructure , Adult , Aged , Aged, 80 and over , Brain/physiopathology , Cohort Studies , Corpus Callosum/physiopathology , Diffusion Magnetic Resonance Imaging/methods , Diffusion Tensor Imaging/methods , Female , Humans , Image Processing, Computer-Assisted , Male , Middle Aged , White Matter/physiopathology , Young Adult
6.
Transl Psychiatry ; 7(5): e1116, 2017 05 02.
Article in English | MEDLINE | ID: mdl-28463239

ABSTRACT

The aetiology of suicidal behaviour is complex, and knowledge about its neurobiological mechanisms is limited. Neuroimaging methods provide a noninvasive approach to explore the neural correlates of suicide vulnerability in vivo. The ENIGMA-MDD Working Group is an international collaboration evaluating neuroimaging and clinical data from thousands of individuals collected by research groups from around the world. Here we present analyses in a subset sample (n=3097) for whom suicidality data were available. Prevalence of suicidal symptoms among major depressive disorder (MDD) cases ranged between 29 and 69% across cohorts. We compared mean subcortical grey matter volumes, lateral ventricle volumes and total intracranial volume (ICV) in MDD patients with suicidal symptoms (N=451) vs healthy controls (N=1996) or MDD patients with no suicidal symptoms (N=650). MDD patients reporting suicidal plans or attempts showed a smaller ICV (P=4.12 × 10-3) or a 2.87% smaller volume compared with controls (Cohen's d=-0.284). In addition, we observed a nonsignificant trend in which MDD cases with suicidal symptoms had smaller subcortical volumes and larger ventricular volumes compared with controls. Finally, no significant differences (P=0.28-0.97) were found between MDD patients with and those without suicidal symptoms for any of the brain volume measures. This is by far the largest neuroimaging meta-analysis of suicidal behaviour in MDD to date. Our results did not replicate previous reports of association between subcortical brain structure and suicidality and highlight the need for collecting better-powered imaging samples and using improved suicidality assessment instruments.


Subject(s)
Brain/diagnostic imaging , Depressive Disorder, Major/diagnostic imaging , Magnetic Resonance Imaging/methods , Neuroimaging/methods , Suicidal Ideation , Adult , Aged , Brain/anatomy & histology , Brain/pathology , Depressive Disorder, Major/epidemiology , Depressive Disorder, Major/psychology , Female , Humans , Male , Middle Aged , Prevalence , Risk Factors , Suicide/psychology , Suicide/statistics & numerical data , Young Adult
7.
Colorectal Dis ; 19(10): 917-926, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28436201

ABSTRACT

AIM: Continence is dependent on anorectal-brain interactions. Consequently, aberrations of the brain-gut axis may be important in the pathophysiology of faecal incontinence (FI) in certain patients. The aim of this study was to assess the feasibility of recording brain responses to rectal mechanical stimulation in patients with FI using functional magnetic resonance imaging (fMRI). METHOD: A prospective, cohort pilot study was performed to assess brain responses during rectal stimulation in 14 patients [four men, mean (SD) age 62 (15) years]. Blood oxygen level dependent (BOLD) signals were measured by fMRI during rest and mechanical distension, involving random repetitions of isobaric phasic rectal distensions at fixed (15 and 45 mmHg) and variable (10% above sensory perception threshold) pressures. RESULTS: Increases in BOLD signals in response to high pressure rectal distension (45 mmHg) and maximum toleration were observed in the cingulate gyrus, thalamus, insular cortex, inferior frontal gyrus, cerebellum, caudate nucleus, supramarginal gyrus, putamen and amygdala. Additionally, activation of the supplementary motor cortex and caudate nucleus with inconsistent activity in the frontal lobe was observed. CONCLUSIONS: This study has demonstrated the feasibility of recording brain responses to rectal mechanical stimulation using fMRI in patients with FI, revealing activity in widespread areas of the brain involved in visceral sensory processing. The observed activity in the supplementary motor cortex and caudate nucleus, with relative paucity of activity in the frontal lobes, warrants investigation in future studies to determine whether aberrations in cerebral processing of rectal stimuli play a role in the pathogenesis of FI.


Subject(s)
Brain/physiopathology , Fecal Incontinence/physiopathology , Magnetic Resonance Imaging/methods , Adult , Aged , Aged, 80 and over , Biomechanical Phenomena/physiology , Brain/diagnostic imaging , Caudate Nucleus/diagnostic imaging , Caudate Nucleus/physiopathology , Feasibility Studies , Fecal Incontinence/diagnostic imaging , Female , Frontal Lobe/diagnostic imaging , Frontal Lobe/physiopathology , Humans , Male , Middle Aged , Motor Cortex/diagnostic imaging , Motor Cortex/physiopathology , Physical Stimulation/methods , Pilot Projects , Prospective Studies , Rectum/physiopathology , Sensation , Young Adult
8.
Ir Med J ; 110(7): 599, 2017 Aug 08.
Article in English | MEDLINE | ID: mdl-29341511

ABSTRACT

D-Dimer (DD) will increase with age and recent studies have shown the upper limit of normal can be raised in those who are low risk and over 50. We studied age adjusted D-dimer (AADD) levels to assess whether pulmonary embolism (PE) could be safely excluded. This study analysed the Emergency Department (ED) Computed Tomographic Pulmonary Angiography (CTPA) requests. There were 756 requests. The parameters studied were; age, DD value, calculated AADD, CT result and Simplified Geneva Score (SGS). The primary outcome was the diagnostic performance of AADD. One hundred and eighty-five patients were included in the final cohort. Twenty-one patients had a negative DD after age adjustment. Of these one had a PE, corresponding to a failure rate of 4.76% (1 in 22). The sensitivity of AADD was 0.96 (95% CI 0.76 to 0.99) and its specificity was 0.12 (95% CI 0.08- 0.19). AADD demonstrated a reduction in false positives with one false negative, giving rise to a failure rate higher than that of other larger studies. Further study is indicated to accurately define the diagnostic characteristics for the Irish context.


Subject(s)
Fibrin Fibrinogen Degradation Products/analysis , Pulmonary Embolism/diagnosis , Age Factors , Biomarkers/blood , Computed Tomography Angiography/statistics & numerical data , Emergency Service, Hospital/statistics & numerical data , False Positive Reactions , Humans , Pulmonary Embolism/blood , Pulmonary Embolism/diagnostic imaging , Retrospective Studies , Sensitivity and Specificity
9.
Mol Psychiatry ; 22(6): 900-909, 2017 06.
Article in English | MEDLINE | ID: mdl-27137745

ABSTRACT

The neuro-anatomical substrates of major depressive disorder (MDD) are still not well understood, despite many neuroimaging studies over the past few decades. Here we present the largest ever worldwide study by the ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) Major Depressive Disorder Working Group on cortical structural alterations in MDD. Structural T1-weighted brain magnetic resonance imaging (MRI) scans from 2148 MDD patients and 7957 healthy controls were analysed with harmonized protocols at 20 sites around the world. To detect consistent effects of MDD and its modulators on cortical thickness and surface area estimates derived from MRI, statistical effects from sites were meta-analysed separately for adults and adolescents. Adults with MDD had thinner cortical gray matter than controls in the orbitofrontal cortex (OFC), anterior and posterior cingulate, insula and temporal lobes (Cohen's d effect sizes: -0.10 to -0.14). These effects were most pronounced in first episode and adult-onset patients (>21 years). Compared to matched controls, adolescents with MDD had lower total surface area (but no differences in cortical thickness) and regional reductions in frontal regions (medial OFC and superior frontal gyrus) and primary and higher-order visual, somatosensory and motor areas (d: -0.26 to -0.57). The strongest effects were found in recurrent adolescent patients. This highly powered global effort to identify consistent brain abnormalities showed widespread cortical alterations in MDD patients as compared to controls and suggests that MDD may impact brain structure in a highly dynamic way, with different patterns of alterations at different stages of life.


Subject(s)
Cerebral Cortex/pathology , Depressive Disorder, Major/diagnostic imaging , Depressive Disorder, Major/pathology , Adolescent , Adult , Brain/pathology , Cerebral Cortex/diagnostic imaging , Female , Frontal Lobe/pathology , Gray Matter/pathology , Gyrus Cinguli/pathology , Humans , Magnetic Resonance Imaging/methods , Male , Neuroimaging/methods , Neuroimaging/psychology , Prefrontal Cortex/pathology , Temporal Lobe/pathology
10.
J Neurol Neurosurg Psychiatry ; 87(7): 754-7, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27071647

ABSTRACT

BACKGROUND: Whole brain volume (WBV) estimates in patients with multiple sclerosis (MS) correlate more robustly with clinical disability than traditional, lesion-based metrics. Numerous algorithms to measure WBV have been developed over the past two decades. We compare Structural Image Evaluation using Normalisation of Atrophy-Cross-sectional (SIENAX) to NeuroQuant and MSmetrix, for assessment of cross-sectional WBV in patients with MS. METHODS: MRIs from 61 patients with relapsing-remitting MS and 2 patients with clinically isolated syndrome were analysed. WBV measurements were calculated using SIENAX, NeuroQuant and MSmetrix. Statistical agreement between the methods was evaluated using linear regression and Bland-Altman plots. Precision and accuracy of WBV measurement was calculated for (1) NeuroQuant versus SIENAX and (2) MSmetrix versus SIENAX. RESULTS: Precision (Pearson's r) of WBV estimation for NeuroQuant and MSmetrix versus SIENAX was 0.983 and 0.992, respectively. Accuracy (Cb) was 0.871 and 0.994, respectively. NeuroQuant and MSmetrix showed a 5.5% and 1.0% volume difference compared with SIENAX, respectively, that was consistent across low and high values. CONCLUSIONS: In the analysed population, NeuroQuant and MSmetrix both quantified cross-sectional WBV with comparable statistical agreement to SIENAX, a well-validated cross-sectional tool that has been used extensively in MS clinical studies.


Subject(s)
Brain/diagnostic imaging , Brain/pathology , Demyelinating Diseases/diagnostic imaging , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Multiple Sclerosis, Relapsing-Remitting/diagnostic imaging , Organ Size/physiology , Adult , Algorithms , Atrophy , Disability Evaluation , Female , Humans , Male , Middle Aged
12.
Mol Psychiatry ; 21(6): 806-12, 2016 06.
Article in English | MEDLINE | ID: mdl-26122586

ABSTRACT

The pattern of structural brain alterations associated with major depressive disorder (MDD) remains unresolved. This is in part due to small sample sizes of neuroimaging studies resulting in limited statistical power, disease heterogeneity and the complex interactions between clinical characteristics and brain morphology. To address this, we meta-analyzed three-dimensional brain magnetic resonance imaging data from 1728 MDD patients and 7199 controls from 15 research samples worldwide, to identify subcortical brain volumes that robustly discriminate MDD patients from healthy controls. Relative to controls, patients had significantly lower hippocampal volumes (Cohen's d=-0.14, % difference=-1.24). This effect was driven by patients with recurrent MDD (Cohen's d=-0.17, % difference=-1.44), and we detected no differences between first episode patients and controls. Age of onset ⩽21 was associated with a smaller hippocampus (Cohen's d=-0.20, % difference=-1.85) and a trend toward smaller amygdala (Cohen's d=-0.11, % difference=-1.23) and larger lateral ventricles (Cohen's d=0.12, % difference=5.11). Symptom severity at study inclusion was not associated with any regional brain volumes. Sample characteristics such as mean age, proportion of antidepressant users and proportion of remitted patients, and methodological characteristics did not significantly moderate alterations in brain volumes in MDD. Samples with a higher proportion of antipsychotic medication users showed larger caudate volumes in MDD patients compared with controls. This currently largest worldwide effort to identify subcortical brain alterations showed robust smaller hippocampal volumes in MDD patients, moderated by age of onset and first episode versus recurrent episode status.


Subject(s)
Brain/pathology , Depressive Disorder, Major/pathology , Adult , Case-Control Studies , Female , Hippocampus/pathology , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neuroimaging/methods
13.
J Clin Child Adolesc Psychol ; 44(1): 145-56, 2015.
Article in English | MEDLINE | ID: mdl-24555865

ABSTRACT

The metacognitive model has increased our understanding of the development and maintenance of generalized anxiety disorders in adults. It states that the combination of positive and negative beliefs about worry creates and sustains anxiety. A recent review argues that the model can be applied to children, but empirical support is lacking. The aim of the 2 presented studies was to explore the applicability of the model in a childhood sample. The first study employed a Danish community sample of youth (n = 587) ages 7 to 17 and investigated the relationship between metacognitions, worry and anxiety. Two multiple regression analyses were performed using worry and metacognitive processes as outcome variables. The second study sampled Danish children ages 7 to 12, and compared the metacognitions of children with a GAD diagnosis (n = 22) to children with a non-GAD anxiety diagnosis (n = 19) and nonanxious children (n = 14). In Study 1, metacognitive processes accounted for an additional 14% of the variance in worry, beyond age, gender, and anxiety, and an extra 11% of the variance in anxiety beyond age, gender, and worry. The Negative Beliefs about Worry scale emerged as the strongest predictor of worry and a stronger predictor of anxiety than the other metacognitive processes and age. In Study 2, children with GAD have significantly higher levels of deleterious metacognitions than anxious children without GAD and nonanxious children. The results offer partial support for the downward extension of the metacognitive model of generalized anxiety disorders to children.


Subject(s)
Anxiety/diagnosis , Anxiety/psychology , Psychiatric Status Rating Scales , Adolescent , Child , Cognition , Denmark , Female , Humans , Male , Models, Psychological , Regression Analysis , Reproducibility of Results
14.
Transl Psychiatry ; 3: e248, 2013 Apr 23.
Article in English | MEDLINE | ID: mdl-23612047

ABSTRACT

Microstructural white matter changes have been reported in the brains of patients across a range of psychiatric disorders. Evidence now demonstrates significant overlap in these regions in patients with affective and psychotic disorders, thus raising the possibility that these conditions share common neurobiological processes. If affective and psychotic disorders share these disruptions, it is unclear whether they occur early in the course or develop gradually with persistence or recurrence of illness. Utilisation of a clinical staging model, as an adjunct to traditional diagnostic practice, is a viable mechanism for measuring illness progression. It is particularly relevant in young people presenting early in their illness course. It also provides a suitable framework for determining the timing of emergent brain alterations, including disruptions of white matter tracts. Using diffusion tensor imaging, we investigated the integrity of white matter tracts in 74 patients with sub-syndromal psychiatric symptoms as well as in 69 patients diagnosed with established psychosis or affective disorder and contrasted these findings with those of 39 healthy controls. A significant disruption in white matter integrity was found in the left anterior corona radiata and in particular the anterior thalamic radiation for both the patients groups when separately contrasted with healthy controls. Our results suggest that patients with sub-syndromal symptoms exhibit discernable early white matter changes when compared with healthy control subjects and more significant disruptions are associated with clinical evidence of illness progression.


Subject(s)
Brain/ultrastructure , Mood Disorders/pathology , Psychotic Disorders/pathology , Adolescent , Adult , Brain/pathology , Case-Control Studies , Diffusion Tensor Imaging , Disease Progression , Female , Humans , Longitudinal Studies , Magnetic Resonance Imaging , Male , Neuroimaging , Prodromal Symptoms , Psychiatric Status Rating Scales , Young Adult
15.
Child Care Health Dev ; 35(5): 717-27, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19531120

ABSTRACT

INTRODUCTION: Internalizing disorders of childhood are a common and disabling problem, with sufferers at increased risk of subsequent psychiatric morbidity. Several studies have found associations between parenting styles and children's internalizing, although few have considered the role of parental discipline. Parental discipline style may exert an effect on children's internalizing symptoms. Anxiety and depression are reliably found to run in families and parental anxiety has been shown to effect parenting behaviour. This study set out to examine the links between parental anxiety, parental discipline style and child internalizing symptoms. METHOD: Eighty-eight parents of children aged 4-10 years were recruited through primary schools. All parents completed questionnaires including measures relating to: adult anxiety (State-Trait Anxiety Inventory - Trait version, Penn State Worry Questionnaire), parental depression (Beck Depression Inventory - Fastscreen), parental discipline (The Parenting Scale), parenting-related attributions (Parenting Attitudes, Beliefs and Cognitions Scale) and child psychological morbidity (Child Behaviour Checklist 4-18 version). RESULTS: Significant correlations were found between both parental anxiety and child internalizing symptoms with ineffective discipline and negative beliefs about parenting. Particularly strong correlations were found between parental anxiety and child internalizing symptoms with harsh discipline. Parents of anxious/withdrawn children were more likely to hold negative beliefs about their child. The link between parental anxiety and child internalizing symptoms was mediated by harsh discipline. The link between parental anxiety and harsh discipline was mediated by parental beliefs about the child. CONCLUSION: Discipline style may be an important factor in the relationship between parent anxiety and child internalizing symptoms.


Subject(s)
Anxiety Disorders/psychology , Depressive Disorder/psychology , Parent-Child Relations , Parenting/psychology , Parents/psychology , Child , Child, Preschool , Culture , Female , Humans , Male , Social Environment , Surveys and Questionnaires
16.
J Neurol Neurosurg Psychiatry ; 77(4): 518-20, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16543534

ABSTRACT

BACKGROUND: Single and repeat concussions have a high prevalence in sport. However, there is limited research into longterm risks associated with single and repeat concussions. OBJECTIVES: To determine the effects of single and repeat historical concussions on the neuropsychological functioning and neurological reports of licensed jockeys. METHODS: Six hundred and ninety eight licensed jockeys in the UK were assessed for neurological and neuropsychological symptoms of concussion at least three months after potential episodes. RESULTS: Jockeys reporting multiple historical injuries versus a single injury showed reliable decrements on a measure of response inhibition and, to a less robust degree, on divided attention. Younger adults showed greater vulnerability. CONCLUSIONS: Repeated concussion is associated with reliable decrements in cognitive performance--even after a three month window for recent recovery.


Subject(s)
Athletic Injuries/complications , Brain Concussion/complications , Cognition Disorders , Adolescent , Adult , Cognition Disorders/diagnosis , Cognition Disorders/epidemiology , Cognition Disorders/etiology , Demography , Educational Status , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Periodicity , Recurrence , Severity of Illness Index , Sex Factors , Time Factors
17.
Clin Psychol Rev ; 26(7): 813-6, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16472896

ABSTRACT

Despite significant advances in our understanding of anxiety in childhood and adolescence, the area is still in its infancy. However, this is an area that is attracting increasing interest from researchers and clinicians alike. This editorial describes some of the aspects of research and clinical attention that are likely to be most fruitful in the coming years, and focusses on some of the inter-related themes that have emerged from the six papers comprising this special edition of Clinical Psychology Review. The first theme concerns the quality and limited power of studies (particularly treatment trials) that have characterised this field. A number of the authors contributing to this edition have noted that this lack of investment in high quality, highly powered research has prevented many of the key questions from being answered. Second, there is growing awareness that we are under-investigating anxiety in younger children. Third, and relatedly, there is still a huge amount of work to be done in understanding the role of the family in child anxiety. What limited information that does exist is confusing and contradictory, and some suggestions for clarifications in this area are made. Finally, there is a plea for more developmentally appropriate, family-focussed and child-led models of anxiety in young populations.


Subject(s)
Anxiety Disorders/psychology , Adolescent , Child , Family/psychology , Humans , Models, Psychological , Psychology, Adolescent/methods , Psychology, Adolescent/trends , Psychology, Child/methods , Psychology, Child/trends
18.
Pediatr Dev Pathol ; 3(3): 223-31, 2000.
Article in English | MEDLINE | ID: mdl-10742409

ABSTRACT

Fetal obstructive uropathy (FOU) is characterized by obstruction of the urethra, renal anomalies, ureterovesical dilatation, oligohydramnios, cryptorchidism, and abdominal muscle wall changes. The main objective of the present study was to better understand the relationship between FOU and renal pathology using a series of 15 male autopsy cases. A total of 11 cases with patent anus and 4 with imperforate anus were analyzed. Of the first group, most cases showed obstruction at the level of prostatic urethra. Seven cases showed obstruction at the level of the prostatic urethra and histologic study revealed scarring and partial or complete absence of the prostate, while in the remaining four cases the prostate was present. Of the cases with imperforate anus, two showed obstruction at the level of prostatic urethra, one showed posterior urethral valves, and one was obstructed at the proximal urethra. In all cases the kidneys showed mixed (dysplastic and cystic) changes with no significant differences between the two groups. An inverse correlation was observed between degree of renal dysplasia and gestational age, whereas the opposite was true for cystic changes. Distal and collecting tubules were more intensely immunoreactive to the anti-cytokeratin antibody when compared to proximal tubules. Moreover, anti-cytokeratin immunoreactivity was more prominent in tubules displaying cystic dilatation. DNA fragmentation analysis of renal tissue revealed a higher apoptosis of mesenchymal and tubular cells in the FOU cases, compared to gestational aged-matched controls. These results suggest that renal anomalies in FOU might be related to the gestational age at which the injury occurred and to the duration of the obstruction.


Subject(s)
Fetus/abnormalities , Kidney/abnormalities , Prostate/abnormalities , Urethra/abnormalities , Urogenital Abnormalities/embryology , Apoptosis , DNA Fragmentation , Gestational Age , Humans , Immunohistochemistry , In Situ Nick-End Labeling , Keratins/analysis , Kidney Diseases, Cystic/embryology , Male , Prune Belly Syndrome/embryology , Urethra/blood supply , Urethral Obstruction/embryology
19.
J Biol Chem ; 274(6): 3602-9, 1999 Feb 05.
Article in English | MEDLINE | ID: mdl-9920908

ABSTRACT

We previously demonstrated that the cystic fibrosis transmembrane conductance regulator (CFTR) is rapidly endocytosed in epithelial cells (Prince, L. S., Workman, R. B., Jr., and Marchase, R. B. (1994) Proc. Natl. Acad. Sci. U. S. A. 91, 5192-5196). To determine the structural features of CFTR required for endocytosis, we prepared chimeric molecules consisting of the amino-terminal (residues 2-78) and carboxyl-terminal tail regions (residues 1391-1476) of CFTR, each fused to the transmembrane and extracellular domains of the transferrin receptor. Functional analysis of the CFTR-(2-78) and CFTR-(1391-1476) indicated that both chimeras were rapidly internalized. Deletion of residues 1440-1476 had no effect on chimera internalization. Mutations of potential internalization signals in both cytoplasmic domains reveal that only one mutation inhibits internalization, Y1424A. Using a surface biotinylation reaction, we also examined internalization rates of wild type and mutant CFTRs expressed in COS-7 cells. We found that both wild type and A1440X CFTR were rapidly internalized, whereas the Y1424A CFTR mutant, like the chimeric protein, had approximately 40% reduced internalization activity. Deletions in the amino-terminal tail region of CFTR resulted in defective trafficking of CFTR out of the endoplasmic reticulum to the cell surface, suggesting that an intact amino terminus is critical for biosynthesis. In summary, our results suggest that both tail regions of CFTR are sufficient to promote rapid internalization of a reporter molecule and that tyrosine 1424 is required for efficient CFTR endocytosis.


Subject(s)
Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Endocytosis , Protein Sorting Signals/metabolism , Tyrosine/metabolism , Amino Acid Sequence , Animals , Base Sequence , COS Cells , Cystic Fibrosis Transmembrane Conductance Regulator/chemistry , DNA Primers , Molecular Sequence Data , Protein Sorting Signals/chemistry , Receptors, Transferrin/metabolism , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/metabolism , Sequence Homology, Amino Acid
20.
J Biol Chem ; 273(23): 14355-62, 1998 Jun 05.
Article in English | MEDLINE | ID: mdl-9603944

ABSTRACT

The sorting of membrane proteins to the lysosome requires tyrosine- or dileucine-based targeting signals. Recycling receptors have similar signals, yet these proteins seldom enter the latter stages of the endocytic pathway. To determine how lysosomal and internalization signals differ, we prepared chimeric molecules consisting of the cytoplasmic tails of CD3 gamma-chain, lysosomal acid phosphatase, and lysosomal-associated membrane glycoprotein-1, each fused to the transmembrane and extracellular domains of the transferrin receptor (TR). Each chimera was expressed on the cell surface and rapidly internalized. Metabolic pulse-chase experiments showed that the CD3 gamma-chain and lysosomal acid phosphatase chimeras, unlike the lysosomal-associated membrane glycoprotein chimera, were rapidly degraded in a post-Golgi compartment following normal glycosylation. Transplantation of signals from CD3 gamma-chain and lysosomal acid phosphatase into the TR cytoplasmic tail in place of the native signal, Y20TRF23, indicated that each signal was sufficient to promote endocytosis but not lysosomal targeting of the resulting mutant. Transplantation of two CD3 signals at specific sites in the TR cytoplasmic tail or a single tyrosine-based signal in a truncated TR tail, however, was sufficient to promote lysosomal targeting. Our results therefore suggest that the relative position of the signal within the cytoplasmic tail is a critical feature that distinguishes lysosomal targeting signals from internalization signals.


Subject(s)
Lysosomes/physiology , Receptors, Transferrin/chemistry , Recombinant Fusion Proteins/chemistry , Acid Phosphatase/chemistry , Amino Acid Sequence , Ammonium Chloride/pharmacology , Animals , Antigens, CD/chemistry , CD3 Complex/chemistry , Chick Embryo , Endocytosis/physiology , Fibroblasts , Humans , Immunohistochemistry , Iron/pharmacokinetics , Lysosomal Membrane Proteins , Membrane Glycoproteins/chemistry , Membrane Proteins/metabolism , Molecular Sequence Data , Mutation/genetics , Tyrosine/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...