Geometric influences on the regional organization of the mammalian brain.

The mammalian brain is comprised of anatomically and functionally distinct regions. Substantial work over the past century has pursued the generation of ever-more accurate maps of regional boundaries, using either expert judgement or data-driven clustering of functional, connectional, and/or architectonic properties. However, these approaches are often purely descriptive, have limited generalizability, and do not elucidate the underlying generative mechanisms that shape the regional organization of the brain.

Mode-based morphometry: A multiscale approach to mapping human neuroanatomy.

Voxel-based morphometry (VBM) and surface-based morphometry (SBM) are two widely used neuroimaging techniques for investigating brain anatomy. These techniques rely on statistical inferences at individual points (voxels or vertices), clusters of points, or a priori regions-of-interest. They are powerful tools for describing brain anatomy, but offer little insights into the generative processes that shape a particular set of findings.

A multiscale characterization of cortical shape asymmetries in early psychosis.

Psychosis has often been linked to abnormal cortical asymmetry, but prior results have been inconsistent. Here, we applied a novel spectral shape analysis to characterize cortical shape asymmetries in patients with early psychosis across different spatial scales. We used the Human Connectome Project for Early Psychosis dataset (aged 16-35), comprising 56 healthy controls (37 males, 19 females) and 112 patients with early psychosis (68 males, 44 females).

The effect of using group-averaged or individualized brain parcellations when investigating connectome dysfunction in psychosis.

Functional magnetic resonance imaging (fMRI) is widely used to investigate functional coupling (FC) disturbances in a range of clinical disorders. Most analyses performed to date have used group-based parcellations for defining regions of interest (ROIs), in which a single parcellation is applied to each brain. This approach neglects individual differences in brain functional organization and may inaccurately delineate the true borders of functional regions.

Can hubs of the human connectome be identified consistently with diffusion MRI?

Recent years have seen a surge in the use of diffusion MRI to map connectomes in humans, paralleled by a similar increase in processing and analysis choices. Yet these different steps and their effects are rarely compared systematically. Here, in a healthy young adult population ( = 294), we characterized the impact of a range of analysis pipelines on one widely studied property of the human connectome: its degree distribution.

Disruptions of Hierarchical Cortical Organization in Early Psychosis and Schizophrenia.

Background: The cerebral cortex is organized hierarchically along an axis that spans unimodal sensorimotor to transmodal association areas. This hierarchy is often characterized using low-dimensional embeddings, termed gradients, of interregional functional coupling estimates measured with resting-state functional magnetic resonance imaging. Such analyses may offer insights into the pathophysiology of schizophrenia, which has been frequently linked to dysfunctional interactions between association and sensorimotor areas.

Geometric constraints on human brain function.

The anatomy of the brain necessarily constrains its function, but precisely how remains unclear. The classical and dominant paradigm in neuroscience is that neuronal dynamics are driven by interactions between discrete, functionally specialized cell populations connected by a complex array of axonal fibres. However, predictions from neural field theory, an established mathematical framework for modelling large-scale brain activity, suggest that the geometry of the brain may represent a more fundamental constraint on dynamics than complex interregional connectivity.

Mode-based morphometry: A multiscale approach to mapping human neuroanatomy.

Voxel-based morphometry (VBM) and surface-based morphometry (SBM) are two widely used neuroimaging techniques for investigating brain anatomy. These techniques rely on statistical inferences at individual points (voxels or vertices), clusters of points, or a priori regions-of-interest. They are powerful tools for describing brain anatomy, but offer little insights into the generative processes that shape a particular set of findings.

Evolutionary shaping of human brain dynamics.

The human brain is distinct from those of other species in terms of size, organization, and connectivity. How do structural evolutionary differences drive patterns of neural activity enabling brain function? Here, we combine brain imaging and biophysical modeling to show that the anatomical wiring of the human brain distinctly shapes neural dynamics. This shaping is characterized by a narrower distribution of dynamic ranges across brain regions compared with that of chimpanzees, our closest living primate relatives.

The individuality of shape asymmetries of the human cerebral cortex.

Asymmetries of the cerebral cortex are found across diverse phyla and are particularly pronounced in humans, with important implications for brain function and disease. However, many prior studies have confounded asymmetries due to size with those due to shape. Here, we introduce a novel approach to characterize asymmetries of the whole cortical shape, independent of size, across different spatial frequencies using magnetic resonance imaging data in three independent datasets.

Risk of sustained SARS-CoV-2 transmission in Queensland, Australia.

We used an agent-based model Covasim to assess the risk of sustained community transmission of SARSCoV-2/COVID-19 in Queensland (Australia) in the presence of high-transmission variants of the virus. The model was calibrated using the demographics, policies, and interventions implemented in the state. Then, using the calibrated model, we simulated possible epidemic trajectories that could eventuate due to leakage of infected cases with high-transmission variants, during a period without recorded cases of locally acquired infections, known in Australian settings as "zero community transmission".

Cortical depth-dependent modeling of visual hemodynamic responses.

A physiologically based three-dimensional (3D) hemodynamic model is developed to predict the experimentally observed blood oxygen level dependent (BOLD) responses versus the cortical depth induced by visual stimuli. Prior 2D approximations are relaxed in order to analyze 3D blood flow dynamics as a function of cortical depth. Comparison of the predictions with experimental data for evoked stimuli demonstrates that the full 3D model performs at least as well as previous approaches while remaining parsimonious.

A nurse practitioner model of care in the era of direct acting antiviral therapy for hepatitis C virus infection.

Background And Aim: Direct-acting antiviral (DAA) therapy for hepatitis C virus (HCV) infection has resulted in high rates of successful disease cure; however, not enough healthcare providers are available to deliver treatment to the population living with chronic HCV. To demonstrate that a nurse practitioner (NP) model of care is non-inferior to specialist gastroenterologist (SG) management of HCV infection, as measured by sustained viral response at 12 weeks (SVR) after initiation of DAA therapy.

Design: Retrospective cohort database study.

Stochastic synchronization of dynamics on the human connectome.

Synchronization is a collective mechanism by which oscillatory networks achieve their functions. Factors driving synchronization include the network's topological and dynamical properties. However, how these factors drive the emergence of synchronization in the presence of potentially disruptive external inputs like stochastic perturbations is not well understood, particularly for real-world systems such as the human brain.

Feasibility of functional magnetic resonance imaging of ocular dominance and orientation preference in primary visual cortex.

A recent hemodynamic model is extended and applied to simulate and explore the feasibility of detecting ocular dominance (OD) and orientation preference (OP) columns in primary visual cortex by means of functional magnetic resonance imaging (fMRI). The stimulation entails a short oriented bar stimulus being presented to one eye and mapped to cortical neurons with corresponding OD and OP selectivity. Activated neurons project via patchy connectivity to excite other neurons with similar OP in nearby visual fields located preferentially along the direction of stimulus orientation.

Invasive and non-invasive assessment of portal hypertension.

Portal hypertension is the central driver of complications in patients with chronic liver diseases and cirrhosis. The diagnosis of portal hypertension has important prognostic and clinical implications. In particular, screening for varices in patients with portal hypertension can effectively reduce the morbidity and mortality of variceal bleeding.

Multiple polymorphisms within the PLCE1 are associated with esophageal cancer via promoting the gene expression in a Chinese Kazakh population.

Although recent genome-wide association studies of esophageal squamous cell carcinoma (ESCC) identified a susceptibility locus in phospholipase C epsilon 1 (PLCE1) in Chinese Han populations, few studies further confirmed these findings in pure Kazakh population in which there are higher incidence and mortality of ESCC. Here, we investigated the potential associations between 19 SNPs of PLCE1 and susceptibility to ESCC in 222 cases and 326 controls from a pure ethnic population of Kazakh. Real-time PCR and immunohistochemistry were performed to detect the PLCE1 expression levels and evaluate their association with PLCE1 polymorphism.

A randomized trial of immunotherapy for persistent genital warts.

Aim: To determine whether immunotherapy with HPV6 L1 virus like particles (VLPs) without adjuvant (VLP immunotherapy) reduces recurrence of genital warts following destructive therapy.

Trial Design: A randomized placebo controlled blinded study of treatment of recurrent genital warts amenable to destructive therapy, conducted independently in Australia and China.

Methods: Patients received conventional destructive therapy of all evident warts together with intramuscular administration of 1 µg, 5 µg or 25 µg of VLP immunotherapy, or of placebo immunotherapy (0.

Prevalence of cervical human papillomavirus (HPV) infection in Vanuatu.

To provide information on human papillomavirus (HPV) prevalence and the distribution of individual HPV types in Pacific Islands, we conducted a population-based survey in Vanuatu, South Pacific. Nine hundred and eighty-seven women between 18 and 64 years of age were included. GP5(+)/6(+)-mediated PCR assay was used for HPV testing.

Evaluation of a cervical cancer screening program based on HPV testing and LLETZ excision in a low resource setting.

We conducted studies in Vanuatu to evaluate potential screening and treatment strategies to assist with control of cervical cancer. In a pilot study of 496 women, visual inspection and cytology were evaluated as screening tests for detection of CIN 2 or worse (CIN2+), observed in 21 of 206 subjects biopsied on the basis of abnormal visual inspection or cytology. Sensitivity of visual inspection with Lugol's Iodine for detection of CIN2+ on biopsy was 0.

Recognition and identification of UV-absorbing leachables in EPREX pre-filled syringes: an unexpected occurrence at a formulation-component interface.

During the period of 1998 to 2002, there was an increase in the incidence of antibody-positive pure red cell aplasia (PRCA) in patients receiving subcutaneous administration of EPREX (epoetinum alfa). As part of the investigation of this event, the aqueous formulation containing polysorbate 80, introduced in 1998, facilitated the leaching of small-molecule, aromatic compounds from the uncoated rubber syringe stoppers. The leachables were identified using Liquid Chromatography-Mass Spectroscopy, Electrospray Ionisation-MS/MS, Dithiothreitol reduction, and Hydrogen/Deuterium exchange.

A high-yield method to extract peptides from rat brain tissue.

A process to extract and enrich extracellular peptides and proteins from tissues should have broad utility in the burgeoning proteomics field. To address this need, a novel three-step protocol was developed to extract polypeptides from whole tissue samples and enrich the extracellular components. The initial homogenization of rat brain was carried out at neutral pH to optimize protein and peptide stability and solubility.

Biomarker discovery in urine by proteomics.

A hypothesis was formed that it would be possible to isolate an adequate amount of protein from a patient, having normal renal function, to identify biological markers of a particular disease state using a variety of proteomics techniques. To support this hypothesis, three samples of urine were collected from a volunteer: first when healthy, later when experiencing acute inflammation due to a pilonidal abcess, and again later still after successful recovery from the condition. The urine from these samples was processed by solid-phase extraction to concentrate and desalt the endogenous proteins and peptides.

Immunohistochemical analysis of forensic evidence from a double homicide.

We report the use of immunohistochemical staining for analysis of forensic evidence from a double homicide. A 38-year-old woman and her 7-year-old daughter were murdered by multiple blows to the head and face with a tomahawk, resulting in multiple fragments of brain tissue scattered about the murder scene. The victims' husband and father was the main suspect, who maintained that he was out of town on business during the evening of the murders.