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1.
J Psychiatr Res ; 152: 250-259, 2022 08.
Article in English | MEDLINE | ID: mdl-35753245

ABSTRACT

Structural brain differences have been described in first-episode schizophrenia spectrum disorders (FES), and often overlap with those evident in the metabolic syndrome (MetS). We examined the associations between body mass index (BMI) and brain structures involved in food intake regulation in minimally treated FES patients (n = 117) compared to healthy controls (n = 117). The effects of FES diagnosis, BMI and their interactions on our selected prefrontal cortical thickness and subcortical gray matter volume regions of interest (ROIs) were investigated with hierarchical multivariate regressions, followed by post-hoc regressions for the individual ROIs. In a secondary analysis, we examined the relationships of other MetS risk factors and psychopathology with the brain ROIs. Both illness and BMI significantly predicted the grouped prefrontal cortical thickness ROIs, whereas only BMI predicted the grouped subcortical volume ROIs. For the individual ROIs, schizophrenia diagnosis predicted thinner left and right frontal pole and right lateral OFC thickness, and increased BMI predicted thinner left and right caudal ACC thickness. There were no significant main or interaction effects for diagnosis and BMI on any of the individual subcortical volume ROIs. Secondary analyses suggest associations between several brain ROIs and individual MetS risk factors, but not with psychopathology. Our findings indicate differential, independent effects for FES diagnosis and BMI on brain structures. Limited evidence suggests that the BMI effects are more prominent in FES. Exploratory analyses suggest associations between other MetS risk factors and some brain ROIs.


Subject(s)
Appetite Regulation , Brain , Schizophrenia , Body Mass Index , Brain/diagnostic imaging , Brain/pathology , Case-Control Studies , Humans , Magnetic Resonance Imaging , Schizophrenia/diagnostic imaging , Schizophrenia/pathology
2.
S Afr Med J ; 110(10): 1045-1049, 2020 Sep 30.
Article in English | MEDLINE | ID: mdl-33205737

ABSTRACT

BACKGROUND: Workplace wellness and disease-prevention programmes have been given increasing attention as a means to improve employee health and lower health costs. Health risk factors have been associated with improved work productivity. Further, health risk is reduced with improved cardiorespiratory fitness (CRF). Therefore, personal and workplace benefits may be achieved by workplace wellness programmes. OBJECTIVES: To investigate the effect of an on-site exercise-based wellness programme in a South African (SA) corporation. The impact of the programme on health risk factors, physiological parameters and corporate productivity indices was assessed. METHODS: Members joining the on-site gym facility of an SA corporation embarked on an individualised 12-week exercise programme, designed using the MyWellness Technogym Cloud platform and based on the participant's cardiovascular risk stratification. Weight, height, body mass index (BMI), blood pressure, waist circumference, CRF and muscle strength measures were assessed at the start and the end of the 12-week intervention. The number of pre- and postintervention cardiac risk factors were also applied to the Association of Health Productivity Management formula to estimate the effect of the intervention on absenteeism, presenteeism and productivity loss. RESULTS: The number of cardiovascular risk factors decreased in the low-, medium- and high-risk groups (68.1%, 42.7% and 41%, respectively). Body mass and BMI decreased significantly (mean (standard deviation (SD) ‒0.3 (5.0)% and ‒0.3 (5.4)%, respectively). Waist circumference also decreased significantly by 2.2% (6.3%). Only the diastolic blood pressure component of blood pressure changed significantly (‒1.2 (14.7)%) and VO2 peak increased by 14.2%. Upper- and lower-body strength improved by 17.9% and 20%, respectively. VO2 peak, BMI and lower-body strength were the only variables that changed significantly after effect size calculations were applied. Furthermore, the predicted impact on productivity loss showed a 1.1% improvement. This was the result of a predicted reduction in absenteeism (0.4%) and a reduction in presenteeism (0.8%). CONCLUSIONS: This corporate on-site exercise intervention programme positively affected the cardiovascular risk factors, biometrics, muscle strength and CRF of employees. These health outcomes decreased employee productivity loss. On-site workplace wellness programmes should be encouraged.


Subject(s)
Cardiovascular Diseases/prevention & control , Exercise , Fitness Centers/organization & administration , Health Promotion/organization & administration , Heart Disease Risk Factors , Occupational Health , Absenteeism , Adult , Blood Pressure , Body Mass Index , Cardiorespiratory Fitness , Female , Humans , Lower Extremity/physiology , Male , Muscle Strength , Oxygen Consumption , South Africa , Upper Extremity/physiology , Waist Circumference
3.
Nat Commun ; 11(1): 4500, 2020 09 09.
Article in English | MEDLINE | ID: mdl-32908152

ABSTRACT

Permafrost degradation may lead to mobilization of carbon and nutrients and enhance microbial processing rates of previously frozen organic matter. Although the pool size and chemical composition of dissolved organic matter (DOM) are fundamental determinants of the carbon cycle in Arctic watersheds, its source within the seasonally thawing active layer and the underlying permafrost remains largely uncharacterized. Here, we used 25 soil cores that extended down into the permafrost from nine sites across Arctic Canada to quantify dissolved organic carbon (DOC) and nitrogen stocks, and to characterize DOM optical properties. Organic permafrost stores 5-7 times more DOC and ammonium than the active layer and mineral permafrost. Furthermore, the permafrost layers contain substantial low molecular weight DOM with low aromaticity suggesting high biodegradability. We conclude that soil organic matter stoichiometry and cryogenic processes determine permafrost DOM chemistry, and that thawing will mobilize large amounts of labile DOC and ammonium into Arctic watersheds.

4.
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
5.
Metab Brain Dis ; 31(1): 81-91, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26616173

ABSTRACT

Neuroimaging studies have indicated that prenatal alcohol exposure is associated with alterations in the structure of specific brain regions. However, the temporal specificity of such changes and their behavioral consequences are less known. Here we explore the brain structure of infants with in utero exposure to alcohol shortly after birth. T2 structural MRI images were acquired from 28 alcohol-exposed infants and 45 demographically matched healthy controls at 2-4 weeks of age on a 3T Siemens Allegra system as part of large birth cohort study, the Drakenstein Child Health Study (DCHS). Neonatal neurobehavior was assessed at this visit; early developmental outcome assessed on the Bayley Scales of Infant Development III at 6 months of age. Volumes of gray matter regions were estimated based on the segmentations of the University of North Carolina neonatal atlas. Significantly decreased total gray matter volume was demonstrated for the alcohol-exposed cohort compared to healthy control infants (p < 0.001). Subcortical gray matter regions that were significantly different between groups after correcting for overall gray matter volume included left hippocampus, bilateral amygdala and left thalamus (p < 0.01). These findings persisted even when correcting for infant age, gender, ethnicity and maternal smoking status. Both early neurobehavioral and developmental adverse outcomes at 6 months across multiple domains were significantly associated with regional volumes primarily in the temporal and frontal lobes in infants with prenatal alcohol exposure. Alcohol exposure during the prenatal period has potentially enduring neurobiological consequences for exposed children. These findings suggest the effects of prenatal alcohol exposure on brain growth is present very early in the first year of life, a period during which the most rapid growth and maturation occurs.


Subject(s)
Central Nervous System Depressants/adverse effects , Ethanol/adverse effects , Fetus/drug effects , Gray Matter/drug effects , Gray Matter/pathology , Adult , Alcohol Drinking/adverse effects , Child Development/drug effects , Cohort Studies , Female , Gray Matter/growth & development , Humans , Infant , Infant, Newborn , Magnetic Resonance Imaging , Male , Pregnancy , Prenatal Exposure Delayed Effects , Sex Characteristics , Smoking/adverse effects , Socioeconomic Factors , South Africa
6.
Afr J Psychiatry (Johannesbg) ; 14(4): 310-4, 2011 Sep.
Article in English | MEDLINE | ID: mdl-22038430

ABSTRACT

OBJECTIVE: To examine hippocampal volume and white matter tracts in women with and without intimate partner violence (IPV). METHOD: Nineteen women with IPV exposure in the last year, and 21 women without IPV exposure in the last year underwent structural magnetic resonance imaging (MRI) including diffusion tensor imaging (DTI) sequences. Additional data on alcohol use and presence of psychiatric disorder was collected. Differences in fractional anisotropy (FA) between the two groups were examined, using a statistical model that included demographic measures, alcohol use and psychiatric disorder. RESULTS: IPV subjects did not demonstrate significantly different hippocampal volumes compared to subjects without recent IPV. FA was, however, significantly reduced in the body of the corpus callosum of IPV subjects. Adjusting for age, alcohol use, smoking and psychiatric diagnosis did not change the significance of the result. CONCLUSION: Data on hippocampal volume in IPV are inconsistent, perhaps reflecting the fact that multiple factors influence this measure. Reduced FA in the body of the corpus callosum in IPV suggests altered integrity of this white matter tract; additional work is needed to address the underlying mechanisms and clinical correlates of this finding.


Subject(s)
Brain Mapping/methods , Brain/pathology , Domestic Violence , Magnetic Resonance Imaging/methods , Adult , Anisotropy , Corpus Callosum/pathology , Diffusion Magnetic Resonance Imaging/methods , Female , Hippocampus/pathology , Humans , Image Processing, Computer-Assisted/methods , Nerve Fibers, Myelinated/pathology , Organ Size , Rural Population/statistics & numerical data , Sexual Partners , South Africa , Young Adult
8.
Pathol Biol (Paris) ; 36(5): 540-3, 1988 May.
Article in French | MEDLINE | ID: mdl-3136431

ABSTRACT

This study reports 45 cases of respiratory tract infection associated with Branhamella catarrhalis, diagnosed by bacteriological examination out of 980 sputum samples studied over a 6 months period. These infections were observed mainly in patients with chronic respiratory disease (68.9%). More than half of the isolates were found in pure culture, others were isolated from mixed infections most often with Haemophilus influenzae, Streptococcus pneumoniae or H. influenzae plus S. pneumoniae. 64.7% of Branhamella catarrhalis isolates produced beta-lactamase. In vitro antimicrobial susceptibility testing demonstrated that the B. catarrhalis isolates, including beta-lactamase producing strains, were very susceptible to clavulanic acid plus amoxycillin (MIC90:0.12 microgram/ml) as well as to doxycycline and erythromycin (MIC90:0.5 microgram/ml).


Subject(s)
Amoxicillin/pharmacology , Cefotaxime/pharmacology , Clavulanic Acids/pharmacology , Doxycycline/pharmacology , Erythromycin/pharmacology , Moraxella catarrhalis/drug effects , Respiratory Tract Infections/microbiology , Adult , Aged , Aged, 80 and over , Clavulanic Acid , Female , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Moraxella catarrhalis/enzymology , Moraxella catarrhalis/isolation & purification , beta-Lactamases/biosynthesis
9.
Basic Res Cardiol ; 80(5): 564-79, 1985.
Article in English | MEDLINE | ID: mdl-4074290

ABSTRACT

The article describes a method for monitoring the total energy output and oxygen uptake of isolated perfused rat hearts with working left ventricles. Twenty-two unpaced hearts (rates 4-4.5 bs-1) were separately investigated inside a flow micro-calorimeter (one minute for 90% thermal response) at 37 degrees C. They pumped fluid into an artificial arterial system with adjustable linear peripheral resistance and variable volume compliance. After about 20-40 minutes a steady state period was achieved and most of the hearts continued to operate in this state for a further 40-100 minutes. In the steady state the outputs were in the ranges of 30-50 mJ s-1g-1 mechanical power (per gram tissue dry weight) and 100-300 mJ s-1g-1 heat production at an oxygen uptake of between 0.01 and 0.02 cm3 O2 s-1g-1. This resulted in approximately constant cardiac outputs between 2 and 4 cm3 s-1g-1 aortic and coronary fluid and stable mechanical efficiencies between 12 and 20%. The energy balance in steady state under a number of defined arterial loads was also analyzed. The hearts attained reproducible maxima of mechanical efficiency at specific loads. Methods to allocate reference points in the energy scheme are discussed. The yield of biochemical energy from the perfusion fluid (utilized for contraction and heat production) was (on average) 21 J per cm3 oxygen consumption (energy equivalent of oxygen). No obvious correlation between this value and the mechanical efficiency was evident.


Subject(s)
Heart/physiology , Animals , Body Temperature Regulation , Calorimetry , Energy Metabolism , In Vitro Techniques , Male , Myocardial Contraction , Myocardium/metabolism , Oxygen Consumption , Rats , Rats, Inbred Strains
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