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INTRODUCTION: There is a growing body of evidence demonstrating the benefit of flash glucose monitoring in people living with type 2 diabetes mellitus (T2DM). This real-world study aimed to evaluate the effect of initiating flash glucose monitoring on change in HbA1c after 3-6 months in adults living with T2DM treated with multiple daily injections of insulin. METHODS: A retrospective observational study using data from ten clinical centres in the UK for adults with T2DM treated with multiple daily injections of insulin for at least 1 year was conducted. Patients who had been using the FreeStyle Libre/Libre 2 Flash Glucose Monitoring System for at least 3 months with baseline HbA1c 64-108 mmol/mol (8.0-12.0%) recorded up to 3 months prior to system use were included. Pregnant patients and those on dialysis were excluded. Patients with an HbA1c value measured 3-6 months after commencing flash glucose monitoring were included in the final analysis for evaluation of change. RESULTS: In total, 87 patients were included in the final analysis (mean age, 60.0 ± 11.8 years, 60.9% male, mean body mass index (BMI), 31.6 ± 5.4 [mean ± SD]). From a mean baseline HbA1c of 80 ± 11 mmol/mol (9.5% ± 1.0%), HbA1c lowered by 11 ± 14 mmol/mol (1.0% ± 1.3%) at 3-6 months (p < 0.0001). A decrease was observed independent of age, baseline HbA1c, sex, duration of insulin use and BMI subgroups. CONCLUSIONS: Initiation of flash glucose monitoring was associated with a clinically and statistically significant improvement in HbA1c in a real-world setting at 3-6 months.
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BACKGROUND: TB control requires the understanding and disruption of TB transmission. We describe prevalence, incidence and risk factors associated with childhood TB infection in Cape Town, South Africa. METHODS: We report cross-sectional baseline and prospective incidence data from a large trial among primary school children living in high TB burden communities. Prevalent infection was defined as QuantiFERON™-TB Gold Plus (QFT-Plus) positivity as assessed at baseline. Subsequent conversion to QFT-Plus positivity was measured 3 years later among those QFT-Plus-negative at baseline. Multivariable logistic regression models examined factors associated with TB infection. RESULTS: QuantiFERON-positivity at baseline (prevalence: 22.6%, 95% CI 20.9-24.4), was independently associated with increasing age (aOR 1.24 per additional year, 95% CI 1.15-1.34) and household exposure to TB during the participant's lifetime (aOR 1.87, 95% CI 1.46-2.40). QFT-Plus conversion at year 3 (12.2%, 95% CI 10.5-14.0; annual infection rate: 3.95%) was associated with household exposure to an index TB case (aOR 2.74, 95% CI 1.05-7.18). CONCLUSION: Rates of QFT-diagnosed TB infection remain high in this population. The strong association with household TB exposure reinforces the importance of contact tracing, preventative treatment and early treatment of infectious disease to reduce community transmission.
CONTEXTE: La lutte contre la TB nécessite la compréhension et la perturbation de la transmission de la TB. Nous décrivons la prévalence, l'incidence et les facteurs de risque associés à l'infection tuberculeuse infantile au Cap, en Afrique du Sud. MÉTHODES: Nous rapportons des données transversales de référence et d'incidence prospective provenant d'un vaste essai mené auprès d'enfants d'écoles primaires vivant dans des communautés à forte charge de morbidité tuberculeuse. La prévalence de l'infection a été définie comme la positivité au QuantiFERON™-TB Gold Plus (QFT-Plus) telle qu'évaluée au départ. La conversion subséquente en QFT-Plus positif a été mesurée 3 ans plus tard chez les QFT-Plus négatifs au départ. Des modèles de régression logistique multivariée ont examiné les facteurs associés à l'infection tuberculeuse. RÉSULTATS: La positivité QuantiFERON-au départ (prévalence : 22,6%, IC à 95% 20,924,4), était indépendamment associée à l'augmentation de l'âge (aOR 1,24 par année supplémentaire, IC à 95% 1,151,34) et à l'exposition du ménage à la TB au cours de la vie du participant (aOR 1,87 ; IC à 95% 1,462,40). La conversion QFT-Plus à l'année 3 (12,2%, IC à 95% 10,514,0 ; taux d'infection annuel : 3,95%) était associée à l'exposition du ménage à un cas de tuberculose index (aOR 2,74 ; IC à 95% 1,057,18). CONCLUSION: Les taux d'infection tuberculeuse diagnostiquée par QFT restent élevés dans cette population. La forte association avec l'exposition à la TB dans les ménages renforce l'importance de la recherche des contacts, du traitement préventif et du traitement précoce des maladies infectieuses pour réduire la transmission communautaire.
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Whilst previous research has linked attenuation of the mu rhythm to the observation of specific visual categories, and even to a potential role in action observation via a putative mirror neuron system, much of this work has not considered what specific type of information might be coded in this oscillatory response when triggered via vision. Here, we sought to determine whether the mu rhythm contains content-specific information about the identity of familiar (and also unfamiliar) graspable objects. In the present study, right-handed participants (N = 27) viewed images of both familiar (apple, wine glass) and unfamiliar (cubie, smoothie) graspable objects, whilst performing an orthogonal task at fixation. Multivariate pattern analysis (MVPA) revealed significant decoding of familiar, but not unfamiliar, visual object categories in the mu rhythm response. Thus, simply viewing familiar graspable objects may automatically trigger activation of associated tactile and/or motor properties in sensorimotor areas, reflected in the mu rhythm. In addition, we report significant attenuation in the central beta band for both familiar and unfamiliar visual objects, but not in the mu rhythm. Our findings highlight how analysing two different aspects of the oscillatory response - either attenuation or the representation of information content - provide complementary views on the role of the mu rhythm in response to viewing graspable object categories.
Subject(s)
Recognition, Psychology , Humans , Male , Female , Young Adult , Adult , Recognition, Psychology/physiology , Brain Waves/physiology , Electroencephalography , Pattern Recognition, Visual/physiology , Photic StimulationABSTRACT
Perceptual decisions are derived from the combination of priors and sensorial input. While priors are broadly understood to reflect experience/expertise developed over one's lifetime, the role of perceptual expertise at the individual level has seldom been directly explored. Here, we manipulate probabilistic information associated with a high and low expertise category (faces and cars respectively), while assessing individual level of expertise with each category. 67 participants learned the probabilistic association between a color cue and each target category (face/car) in a behavioural categorization task. Neural activity (EEG) was then recorded in a similar paradigm in the same participants featuring the previously learned contingencies without the explicit task. Behaviourally, perception of the higher expertise category (faces) was modulated by expectation. Specifically, we observed facilitatory and interference effects when targets were correctly or incorrectly expected, which were also associated with independently measured individual levels of face expertise. Multivariate pattern analysis of the EEG signal revealed clear effects of expectation from 100 ms post stimulus, with significant decoding of the neural response to expected vs. not stimuli, when viewing identical images. Latency of peak decoding when participants saw faces was directly associated with individual level facilitation effects in the behavioural task. The current results not only provide time sensitive evidence of expectation effects on early perception but highlight the role of higher-level expertise on forming priors.
Subject(s)
Electroencephalography , Facial Recognition , Humans , Male , Female , Adult , Facial Recognition/physiology , Young Adult , Photic Stimulation , Reaction Time/physiology , Visual Perception/physiology , Face/physiologyABSTRACT
AIMS: We examined severe hospitalised hypoglycaemia (SHH) rates in people with type 1 and type 2 diabetes in Scotland during 2016-2022, stratifying by sociodemographics. METHODS: Using the Scottish National diabetes register (SCI-Diabetes), we identified people with type 1 and type 2 diabetes alive anytime during 2016-2022. SHH events were determined through linkage to hospital admission and death registry data. We calculated annual SHH rates overall and by age, sex, and socioeconomic status. Summary estimates of time and stratum effects were obtained by fitting adjusted generalised additive models using R package mgcv. RESULTS: Rates for those under 20 with type 1 diabetes reached their minimum at the 2020-2021 transition, 30% below the study period average. A gradual decline over time also occurred among 20-49-year-olds with type 1 diabetes. Overall, females had 15% higher rates than males with type 2 diabetes (rate ratio 1.15, 95% CI 1.08-1.22). People in the most versus least deprived quintile experienced 2.58 times higher rates (95% CI 2.27-2.93) in type 1 diabetes and 2.33 times higher (95% CI 2.08-2.62) in type 2 diabetes. CONCLUSIONS: Despite advances in care, SHH remains a significant problem in diabetes. Future efforts must address the large socioeconomic disparities in SHH risks.
Subject(s)
Diabetes Mellitus, Type 1 , Diabetes Mellitus, Type 2 , Hypoglycemia , Male , Female , Humans , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/epidemiology , Cohort Studies , Hypoglycemia/epidemiology , Scotland/epidemiologyABSTRACT
AIMS: To evaluate real-world outcomes in people with Type 1 Diabetes (PwT1D) initiated on Omnipod DASH® Insulin Management System. METHODS: Anonymized clinical data were submitted to a secure web-based tool within the National Health Service network. Hemoglobin A1c (HbA1c), sensor-derived glucometrics, total daily dose of insulin (TDD), and patient-reported outcome changes between baseline and follow-up were assessed. Individuals were classified to "new-to-pump" (switched from multiple daily injections) and "established-on-pump" (switched from a tethered insulin pump) groups. RESULTS: 276 individuals from 11 centers [66.7 % female; 92 % White British; median age 41 years (IQR 20-50); diabetes duration 20 years (IQR 11-31); 49.3 % within "new-to-pump" group] were included. Baseline HbA1c was 8.0 ± 1.3 % (64 ± 14 mmol/mol). At follow-up [3 years (IQR 1.5-3.2)], HbA1c reduced by 0.3 % [(3 mmol/mol); p = 0.002] across the total population, 0.4 % [(5 mmol/mol); p = 0.001] in those "new-to-pump" and remained unchanged in those "established-on-pump". TDD decreased in the "new-to-pump" cohort (baseline:44.9 ± 21.0units vs follow-up:38.1 ± 15.4units, p = 0.002). Of those asked, 141/143 (98.6 %) stated Omnipod DASH had a positive impact on quality of life. CONCLUSIONS: Omnipod DASH was associated with improvements in HbA1c in PwT1D "new-to-pump" and maintained previous HbA1c levels in those "established-on-pump". User satisfaction in all groups and TDD reduction in those "new-to-pump" were reported.
Subject(s)
Diabetes Mellitus, Type 1 , Humans , Female , Adult , Male , Diabetes Mellitus, Type 1/drug therapy , Hypoglycemic Agents/therapeutic use , Glycated Hemoglobin , Quality of Life , State Medicine , Insulin/therapeutic use , Insulin Infusion Systems , Blood GlucoseABSTRACT
Neurons in the primary visual cortex (V1) receive sensory inputs that describe small, local regions of the visual scene and cortical feedback inputs from higher visual areas processing the global scene context. Investigating the spatial precision of this visual contextual modulation will contribute to our understanding of the functional role of cortical feedback inputs in perceptual computations. We used human functional magnetic resonance imaging (fMRI) to test the spatial precision of contextual feedback inputs to V1 during natural scene processing. We measured brain activity patterns in the stimulated regions of V1 and in regions that we blocked from direct feedforward input, receiving information only from non-feedforward (i.e., feedback and lateral) inputs. We measured the spatial precision of contextual feedback signals by generalising brain activity patterns across parametrically spatially displaced versions of identical images using an MVPA cross-classification approach. We found that fMRI activity patterns in cortical feedback signals predicted our scene-specific features in V1 with a precision of approximately 4 degrees. The stimulated regions of V1 carried more precise scene information than non-stimulated regions; however, these regions also contained information patterns that generalised up to 4 degrees. This result shows that contextual signals relating to the global scene are similarly fed back to V1 when feedforward inputs are either present or absent. Our results are in line with contextual feedback signals from extrastriate areas to V1, describing global scene information and contributing to perceptual computations such as the hierarchical representation of feature boundaries within natural scenes.
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AIMS: To assess features associated with glucagon prescribing and hospital admissions with hypoglycaemia in type one diabetes. METHODS: Observational study of 4462 adults. Outcome measures were features associated with glucagon prescriptions and predictors of hospital admissions with hypoglycaemia and high levels of glucagon prescribing. RESULTS: 74 % did not collect any glucagon prescriptions and 2.7 % collected >6 over 3.5 years. Hospital admission with hypoglycaemia (P = 0.032), impaired awareness (P = 0.049) and female sex (P < 0.001) were associated with glucagon collection. More frequent prescribing of glucagon was associated with diabetes duration (P < 0.001) and socioeconomic deprivation (P < 0.001). Higher average glucose (P = 0.047), higher time above 13.9 mM (P = 0.008) and higher SD (P = 0.002) were associated with glucagon prescribing. Diabetes duration (P < 0.001) and HbA1c (P < 0.001) were higher in people with hospitalised hypoglycaemia. Higher time above 13.9 mM (P = 0.004) and SD glucose (P < 0.001) were most clearly associated with hospitalised hypoglycaemia. CONCLUSIONS: A minority of people with type 1 diabetes have access to glucagon suggesting more could be done to better target this treatment. Individuals with risk factors and those with frequent glucagon prescriptions should be identified for interventions known to reduce hypoglycaemia.
Subject(s)
Diabetes Mellitus, Type 1 , Hypoglycemia , Adult , Humans , Female , Glucagon , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 1/epidemiology , Blood Glucose , Blood Glucose Self-Monitoring/adverse effects , Benchmarking , Hypoglycemia/chemically induced , Hypoglycemia/epidemiology , Hypoglycemia/prevention & control , Glucose , Hospitals , Hypoglycemic Agents/adverse effectsABSTRACT
AIMS: We sought to assess whether conversion from Freestyle Libre to Freestyle Libre 2 (with low and high glucose alert functions) was associated with improved glucose metrics. RESEARCH DESIGN AND METHODS: A prospective observational study to assess changes in CGM metrics in 672 adults with type 1 diabetes when converting to Freestyle Libre 2. Secondary outcomes included predictors of reduction in time below range (TBR) and increase in time in range (TIR). RESULTS: TBR fell by a median of 1.0% (IQR -2.7 to 0.3, p < 0.001) after 12 months and TIR decreased by 1.0% (-8.7 to 6.0, p = 0.004). TIR did not fall in people using high glucose alerts (p = 0.353). Average duration of low glucose events (<3.9 mmoL/L) fell by 10 min (-46 to 18, p < 0.001). Significant improvements in TIR (p = 0.029) and time above 13.9 mM (p = 0.002) were observed in those using high glucose alerts. Alert threshold settings were not associated with glycaemic response; however, low alert use was independently associated with a fall in TBR of ≥0.5% (HR 1.9 [95% CI 1.2-3.1], p = 0.009) and high alert use was independently associated with a rise in TIR of ≥5% (HR 1.6 [95% CI 1.0-2.5], p = 0.043) at 12 months. CONCLUSIONS: Conversion to Freestyle Libre 2 was associated with significant improvements in low glucose metrics. Alert function users were more likely to see improvements across all CGM metrics. Challenges remain in encouraging alert use, helping users set optimal alert thresholds and optimizing response to alerts.
Subject(s)
Blood Glucose , Diabetes Mellitus, Type 1 , Adult , Humans , Blood Glucose Self-Monitoring , Prospective StudiesABSTRACT
AIMS: To investigate whether manganese-enhanced magnetic resonance imaging can assess functional pancreatic beta-cell mass in people with type 1 diabetes mellitus. METHODS: In a prospective case-control study, 20 people with type 1 diabetes mellitus (10 with low (≥50 pmol/L) and 10 with very low (<50 pmol/L) C-peptide concentrations) and 15 healthy volunteers underwent manganese-enhanced magnetic resonance imaging of the pancreas following an oral glucose load. Scan-rescan reproducibility was performed in 10 participants. RESULTS: Mean pancreatic manganese uptake was 31 ± 6 mL/100 g of tissue/min in healthy volunteers (median 32 [interquartile range 23-36] years, 6 women), falling to 23 ± 4 and 13 ± 5 mL/100 g of tissue/min (p ≤ 0.002 for both) in people with type1 diabetes mellitus (52 [44-61] years, 6 women) and low or very low plasma C-peptide concentrations respectively. Pancreatic manganese uptake correlated strongly with plasma C-peptide concentrations in people with type1 diabetes mellitus (r = 0.73, p < 0.001) but not in healthy volunteers (r = -0.054, p = 0.880). There were no statistically significant correlations between manganese uptake and age, body-mass index, or glycated haemoglobin. There was strong intra-observer (mean difference: 0.31 (limits of agreement -1.42 to 2.05) mL/100 g of tissue/min; intra-class correlation, ICC = 0.99), inter-observer (-1.23 (-5.74 to 3.27) mL/100 g of tissue/min; ICC = 0.85) and scan-rescan (-0.72 (-2.9 to 1.6) mL/100 g of tissue/min; ICC = 0.96) agreement for pancreatic manganese uptake. CONCLUSIONS: Manganese-enhanced magnetic resonance imaging provides a potential reproducible non-invasive measure of functional beta-cell mass in people with type 1 diabetes mellitus. This holds major promise for investigating type 1 diabetes, monitoring disease progression and assessing novel immunomodulatory interventions.
Subject(s)
Diabetes Mellitus, Type 1 , Insulin-Secreting Cells , Humans , Female , C-Peptide , Manganese , Reproducibility of Results , Case-Control Studies , Insulin-Secreting Cells/pathologyABSTRACT
Importance: Evidence on the effectiveness and safety of COVID-19 therapies across a diverse population with varied risk factors is needed to inform clinical practice. Objective: To assess the safety of neutralizing monoclonal antibodies (nMAbs) for the treatment of COVID-19 and their association with adverse outcomes. Design, Setting, and Participants: This retrospective cohort study included 167â¯183 patients from a consortium of 4 health care systems based in California, Minnesota, Texas, and Utah. The study included nonhospitalized patients 12 years and older with a positive COVID-19 laboratory test collected between November 9, 2020, and January 31, 2022, who met at least 1 emergency use authorization criterion for risk of a poor outcome. Exposure: Four nMAb products (bamlanivimab, bamlanivimab-etesevimab, casirivimab-imdevimab, and sotrovimab) administered in the outpatient setting. Main Outcomes and Measures: Clinical and SARS-CoV-2 genomic sequence data and propensity-adjusted marginal structural models were used to assess the association between treatment with nMAbs and 4 outcomes: all-cause emergency department (ED) visits, hospitalization, death, and a composite of hospitalization or death within 14 days and 30 days of the index date (defined as the date of the first positive COVID-19 test or the date of referral). Patient index dates were categorized into 4 variant epochs: pre-Delta (November 9, 2020, to June 30, 2021), Delta (July 1 to November 30, 2021), Delta and Omicron BA.1 (December 1 to 31, 2021), and Omicron BA.1 (January 1 to 31, 2022). Results: Among 167â¯183 patients, the mean (SD) age was 47.0 (18.5) years; 95 669 patients (57.2%) were female at birth, 139 379 (83.4%) were White, and 138 900 (83.1%) were non-Hispanic. A total of 25â¯241 patients received treatment with nMAbs. Treatment with nMAbs was associated with lower odds of ED visits within 14 days (odds ratio [OR], 0.76; 95% CI, 0.68-0.85), hospitalization within 14 days (OR, 0.52; 95% CI, 0.45-0.59), and death within 30 days (OR, 0.14; 95% CI, 0.10-0.20). The association between nMAbs and reduced risk of hospitalization was stronger in unvaccinated patients (14-day hospitalization: OR, 0.51; 95% CI, 0.44-0.59), and the associations with hospitalization and death were stronger in immunocompromised patients (hospitalization within 14 days: OR, 0.31 [95% CI, 0.24-0.41]; death within 30 days: OR, 0.13 [95% CI, 0.06-0.27]). The strength of associations of nMAbs increased incrementally among patients with a greater probability of poor outcomes; for example, the ORs for hospitalization within 14 days were 0.58 (95% CI, 0.48-0.72) among those in the third (moderate) risk stratum and 0.41 (95% CI, 0.32-0.53) among those in the fifth (highest) risk stratum. The association of nMAb treatment with reduced risk of hospitalizations within 14 days was strongest during the Delta variant epoch (OR, 0.37; 95% CI, 0.31-0.43) but not during the Omicron BA.1 epoch (OR, 1.29; 95% CI, 0.68-2.47). These findings were corroborated in the subset of patients with viral genomic data. Treatment with nMAbs was associated with a significant mortality benefit in all variant epochs (pre-Delta: OR, 0.16 [95% CI, 0.08-0.33]; Delta: OR, 0.14 [95% CI, 0.09-0.22]; Delta and Omicron BA.1: OR, 0.10 [95% CI, 0.03-0.35]; and Omicron BA.1: OR, 0.13 [95% CI, 0.02-0.93]). Potential adverse drug events were identified in 38 treated patients (0.2%). Conclusions and Relevance: In this study, nMAb treatment for COVID-19 was safe and associated with reductions in ED visits, hospitalization, and death, although it was not associated with reduced risk of hospitalization during the Omicron BA.1 epoch. These findings suggest that targeted risk stratification strategies may help optimize future nMAb treatment decisions.
Subject(s)
COVID-19 , Infant, Newborn , Humans , Female , Middle Aged , Male , SARS-CoV-2 , Retrospective Studies , Antibodies, MonoclonalABSTRACT
This best practice guide is written with the aim of providing an overview of current hybrid closed-loop (HCL) systems in use within the United Kingdom's (UK) National Health Service (NHS) and to provide education and advice for their management on both an individual and clinical service level. The environment of diabetes technology, and particularly HCL systems, is rapidly evolving. The past decade has seen unprecedented advances in the development of HCL systems. These systems improve glycaemic outcomes and reduce the burden of treatment for people with type 1 diabetes (pwT1D). It is anticipated that access to these systems will increase in England as a result of updates in National Institute of Health and Care Excellence (NICE) guidance providing broader support for the use of real-time continuous glucose monitoring (CGM) for pwT1D. NICE is currently undertaking multiple-technology appraisal into HCL systems. Based on experience from centres involved in supporting advanced technologies as well as from the recent NHS England HCL pilot, this guide is intended to provide healthcare professionals with UK expert consensus on the best practice for initiation, optimisation and ongoing management of HCL therapy.
Subject(s)
Blood Glucose Self-Monitoring , Diabetes Mellitus, Type 1 , Humans , Blood Glucose , Diabetes Mellitus, Type 1/drug therapy , England , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use , Insulin Infusion Systems , State Medicine , TechnologySubject(s)
Blood Glucose , Hypoglycemia , Adult , Humans , Hypoglycemia/epidemiology , Hypoglycemic Agents , Morbidity , Primary Health Care , InsulinSubject(s)
Diabetes Mellitus , Hypoglycemia , Humans , Hypoglycemic Agents , Socioeconomic Factors , United KingdomABSTRACT
BACKGROUND: This study investigated whether the time to amputation (TtoA) after a work-related injury had a significant effect on the medical costs accrued in the first year after injury. DATA SOURCE: Six thousand nine hundred fifty-three person-level workers' compensation claims data from the state of California, USA, from 2007 to 2018. METHODS: Multiple quantile regression was used to assess the impact of TtoA on medical costs accrued during the first 12 months after injury. Three time intervals for TtoA were investigated: immediate (0, 1 days), short-delay (2-31 days), and long-delay (>31 days). RESULTS: The median (interquartile range) medical dollars paid per claim during the first 12 months for the study population was $12,414 ($6,324-$29,347). Amputations that occurred during the short-delay time interval resulted in significant ( p < 0.001) median (95% CI) savings of -$3,196 (-$3,968 to -$2,424) compared with the immediate amputation group. The long-delay time interval resulted in significantly ( p < 0.001) increased median (95% CI) spending of $5,613 ($4,675-$6,551) compared with the immediate amputation group. Covariates that significantly increased costs were medical intensity, medical complexity, use of a prosthesis, and if the injured worker pursued legal action in addition to a workers' compensation claim. CONCLUSIONS: This study presents the impact of TtoA on medical spending in the first year after a work-related injury that results in an amputation. Amputations that occurred within the first month after an injury resulted in reduced medical spending compared with immediate amputations, and amputations that occurred after the first month resulted in increased medical spending.
Subject(s)
Occupational Injuries , Workers' Compensation , Humans , California , Amputation, SurgicalABSTRACT
Although humans are considered to be face experts, there is a well-established reliable variation in the degree to which neurotypical individuals are able to learn and recognise faces. While many behavioural studies have characterised these differences, studies that seek to relate the neuronal response to standardised behavioural measures of ability remain relatively scarce, particularly so for the time-resolved approaches and the early response to face stimuli. In the present study we make use of a relatively recent methodological advance, multi-variate pattern analysis (MVPA), to decode the time course of the neural response to faces compared to other object categories (inverted faces, objects). Importantly, for the first time, we directly relate metrics of this decoding assessed at the individual level to gold-standard measures of behavioural face processing ability assessed in an independent task. Thirty-nine participants completed the behavioural Cambridge Face Memory Test (CFMT), then viewed images of faces and houses (presented upright and inverted) while their neural activity was measured via electroencephalography. Significant decoding of both face orientation and face category were observed in all individual participants. Decoding of face orientation, a marker of more advanced face processing, was earlier and stronger in participants with higher levels of face expertise, while decoding of face category information was earlier but not stronger for individuals with greater face expertise. Taken together these results provide a marker of significant differences in the early neuronal response to faces from around 100 ms post stimulus as a function of behavioural expertise with faces.
Subject(s)
Facial Recognition , Humans , Facial Recognition/physiology , Electroencephalography , Learning , Orientation, Spatial , Pattern Recognition, Visual/physiology , Photic Stimulation/methodsABSTRACT
Neurons, even in the earliest sensory regions of cortex, are subject to a great deal of contextual influences from both within and across modality connections. Recent work has shown that primary sensory areas can respond to and, in some cases, discriminate stimuli that are not of their target modality: for example, primary somatosensory cortex (SI) discriminates visual images of graspable objects. In the present work, we investigated whether SI would discriminate sounds depicting hand-object interactions (e.g. bouncing a ball). In a rapid event-related functional magnetic resonance imaging experiment, participants listened attentively to sounds from 3 categories: hand-object interactions, and control categories of pure tones and animal vocalizations, while performing a one-back repetition detection task. Multivoxel pattern analysis revealed significant decoding of hand-object interaction sounds within SI, but not for either control category. Crucially, in the hand-sensitive voxels defined from an independent tactile localizer, decoding accuracies were significantly higher for hand-object interactions compared to pure tones in left SI. Our findings indicate that simply hearing sounds depicting familiar hand-object interactions elicit different patterns of activity in SI, despite the complete absence of tactile stimulation. These results highlight the rich contextual information that can be transmitted across sensory modalities even to primary sensory areas.
Subject(s)
Hand , Somatosensory Cortex , Animals , Somatosensory Cortex/diagnostic imaging , Somatosensory Cortex/physiology , Touch/physiology , Neurons/physiology , Magnetic Resonance Imaging , Brain MappingABSTRACT
INTRODUCTION: Hormonal contraceptive use might impair bone health and increase the risk of stress fracture by decreasing endogenous oestrogen production, a central regulator of bone metabolism. This cross-sectional study investigated bone density and biochemical markers of bone metabolism in women taking hormonal contraceptives on entry to basic military training. METHODS: Forty-five female British Army recruits had biochemical markers of bone metabolism, areal bone mineral density (aBMD) and tibial speed of sound (tSOS) measured at the start of basic military training. Participants were compared by their method of hormonal contraception: no hormonal contraception (NONE), combined contraceptive pill (CP) or depot-medroxyprogesterone acetate (DMPA) (20±2.8 years, 1.64±0.63 m, 61.7±6.2 kg). RESULTS: aBMD was not different between groups (p≥0.204), but tSOS was higher in NONE (3%, p=0.014) when compared with DMPA users. Beta C-terminal telopeptide was higher in NONE (45%, p=0.037) and DMPA users (90%, p=0.003) compared with CP users. Procollagen type 1 N-terminal propeptide was higher in DMPA users compared with NONE (43%, p=0.045) and CP users (127%, p=0.001), and higher in NONE compared with CP users (59%, p=0.014). Bone alkaline phosphatase was higher in DMPA users compared with CP users (56%, p=0.044). CONCLUSIONS: DMPA use was associated with increased bone turnover and decreased cortical bone integrity of the tibia. Lower cortical bone integrity in DMPA users was possibly mediated by increased intracortical remodelling, but trabecular bone was not affected by contraceptive use.
Subject(s)
Contraceptive Agents, Female , Military Personnel , Female , Humans , Bone Density , Medroxyprogesterone Acetate/pharmacology , Contraceptive Agents, Female/pharmacology , Cross-Sectional Studies , BiomarkersABSTRACT
Bone graft resorption following the Latarjet procedure has received considerable concern. Current methods quantifying bone graft resorption rely on two-dimensional (2D) CT-scans or three-dimensional (3D) techniques, which do not represent the whole graft volume/resorption (i.e., 2D assessment) or expose patients to additional radiation (i.e., 3D assessment) as this technique relies on early postoperative CT-scans. The aim of the present study was to develop and validate a patient-specific, CT-morphometric technique combining image registration with 3D CT-reconstruction to quantify bone graft resorption following the Latarjet procedure for recurrent anterior shoulder instability. Pre-operative and final follow-up CT-scans were segmented to digitally reconstruct 3D scapula geometries. A virtual Latarjet procedure was then conducted to model the timepoint-0 graft volume, which was compared with the final follow-up graft volume. Graft resorption at final follow-up was highly correlated to the 2D gold standard-technique by Zhu (Kendall tau coefficient = 0.73; p < 0.001). The new technique was also found to have excellent inter- and intra-rater reliability (ICC values, 0.931 and 0.991; both p < 0.001). The main finding of this study is that the technique presented is a valid and reliable method that provides the advantage of 3D-assessment of graft resorption at long-term follow-up without the need of an early postoperative CT-scan.