Automatic Misalignment Correction in Neuroimages Using Surface Symmetry Priors

Many brain imaging procedures require the careful alignment of different sets of images obtained in the same individual. The available automatic methods for brain alignment are susceptible to improvement. This paper discusses briefly a new automatic method to reinstall the tilted orientation of head images, using surface symmetry as a prior

Employing Symmetry Features for Automatic Misalignment Correction in Neuroimages

A novel method to automatically compute the symmetry plane and to correct the 3D orientation of neuro-images is presented. In acquisition of neuroimaging scans, the lack of perfect alignment of a patient's head makes it challenging to evaluate brain images. By deploying a shape-based criterion, the symmetry plane is defined as a plane that best matches external surface points on one side of the head, with their counterparts on the other side. In our method, the head volume is represented as a re-parameterized surface point cloud, where each location is parameterized by its elevation (latitude), azimuth (longitude), and radius. The search for the best matching surfaces is implemented in a multi-resolution paradigm, and the computation time is significantly decreased. The algorithm was quantitatively evaluated using in both simulated data and in real T1, T2, Flair magnetic resonance patient images. This algorithm is found to be fast (< 10s per MR volume), robust and accurate (< .6 degree of Mean Angular Error), invariant to the acquisition noise, slice thickness, bias field, and pathological asymmetries

Sea-ice response to climate change in the Bering Sea during the Mid-Pleistocene Transition

This is the final version. Available on open access from Elsevier via the DOI in this recordData availability: All data presented in this paper is available in the Supplementary Materials.Sea-ice is believed to be an important control on climatic changes through the Mid-Pleistocene Transition (MPT; 0.6–1.2 Ma). However, the low resolution/short timescale of existing reconstructions prevents a full evaluation of these dynamics. Here, diatom assemblages from the Bering Sea are used to investigate sea-ice evolution on millennial timescales. We find that sea-ice was primarily controlled by ice-sheet/sea level fluctuations that modulated warm water flow into the Bering Sea. Facilitated by an amplified Walker circulation, sea-ice expansion began at ∼1.05 Ma with a step-increase during the 900 kyr event. Maximal pack ice was simultaneous with glacial maxima, suggesting sea-ice was responding to, rather than modulating ice-sheet dynamics, as proposed by the sea-ice switch hypothesis. Significant pack ice, coupled with Bering Strait closure at 0.9 Ma, indicates that brine rejection played an integral role in the glacial expansion/deglacial collapse of intermediate waters during the MPT, regulating subarctic ocean-atmospheric exchanges of CO2.Natural Environment Research Council (NERC)British Geological Surve

Diabetic pneumopathy-a new diabetes-associated complication: Mechanisms, consequences and treatment considerations.

Patients with diabetes are over-represented among the total cases reported with "idiopathic" pulmonary fibrosis (IPF). This raises the question, whether this is an association only or whether diabetes itself can cause pulmonary fibrosis. Recent studies in mouse models of type 1 and type 2 diabetes demonstrated that diabetes causes pulmonary fibrosis. Both types of diabetes trigger a cascade, starting with increased DNA damage, an impaired DNA repair, and leading to persistent DNA damage signaling. This response, in turn, induces senescence, a senescence-associated-secretory phenotype (SASP), marked by the release of pro-inflammatory cytokines and growth factors, finally resulting in fibrosis. Restoring DNA repair drives fibrosis into remission, thus proving causality. These data can be translated clinically to patients with type 2 diabetes, characterized by long-term diabetes and albuminuria. Hence there are several arguments, to substitute the term "idiopathic" pulmonary fibrosis (IPF) in patients with diabetes (and exclusion of other causes of lung diseases) by the term "diabetes-induced pulmonary fibrosis" (DiPF). However, future studies are required to establish this term and to study whether patients with diabetes respond to the established therapies similar to non-diabetic patients

Asprosin response in hypoglycemia is not related to hypoglycemia unawareness but rather to insulin resistance in type 1 diabetes.

Asprosin is a counter-regulatory hormone to insulin which plays a role in fasting. It may therefore also play a role in hypoglycaemia unawareness, which has been subsequently examined in this pilot study. Intravenous glucose tolerance test was used to induce controlled hyperglycemia whereas a hyperinsulinemic clamp test was used to induce a controlled hypoglycaemia in 15 patients with diabetes type 1, with and without hypoglycaemia unawareness. Changes in asprosin plasma levels did not differ between patients with and without hypoglycaemia unawareness. However, nine patients with insulin resistance as well as higher liver stiffness values and low-density lipoprotein but lower high-density lipoprotein levels did not show the expected increase in asprosin plasma levels during hypoglycemia. Therefore, insulin resistance and alterations in liver structure, most likely early stages of non-alcoholic fatty liver disease, seem to be relevant in type 1 diabetes and do not only lead to elevated plasma levels of asprosin, but also to a blunted asprosin response in hypoglycemia

Understanding diabetic neuropathy: From subclinical nerve lesions to severe nerve fiber deficits. A cross-sectional study in patients with type 2 diabetes and healthy controls.

Studies on magnetic resonance neurography (MRN) in diabetic polyneuropathy (DPN) have found proximal sciatic nerve lesions. The aim of this study was to evaluate the functional relevance of sciatic nerve lesions in DPN, expecting correlations with the impairment of large fiber function. 61 patients with diabetes mellitus type 2 (48 with, 13 without DPN) and 12 controls were enrolled, undergoing MRN, quantitative sensory testing, and electrophysiological examinations. There were differences in mechanical detection (Aβ fibers) and mechanical pain (Aδ fibers), but not in thermal pain and thermal detection clusters (C fibers) between the groups. Lesion load correlated with lower Aα, Aβ, and Aδ fiber, but not C fiber function in all participants. Patients with lower function showed a higher load of nerve lesions than patients with elevated function or no measurable deficit despite apparent DPN. Longer diabetes duration was associated with higher lesion load in patients with DPN, suggesting that nerve lesions in DPN may accumulate over time and become clinically relevant once a critical amount of nerve fascicles is affected. Moreover, MRN is an objective method for determining lower function mainly in medium and large fibers in DPN

Fractional anisotropy and troponin T parallel structural nerve damage at the upper extremities in a group of patients with prediabetes and type 2 diabetes - a study using 3T magnetic resonance neurography.

BackgroundRecent studies have found that troponin T parallels the structural and functional decay of peripheral nerves at the level of the lower limbs in patients with type 2 diabetes (T2D). The aim of this study was to determine whether this finding can also be reproduced at the level of the upper limbs.MethodsTen patients with fasting glucose levels &gt;100 mg/dl (five with prediabetes and five with T2D) underwent magnetic resonance neurography of the right upper arm comprising T2-weighted and diffusion weighted sequences. The fractional anisotropy (FA), an indicator for the structural integrity of peripheral nerves, was calculated in an automated approach for the median, ulnar, and radial nerve. All participants underwent additional clinical, serological, and electrophysiological assessments.ResultsHigh sensitivity Troponin T (hsTNT) and HbA1c were negatively correlated with the average FA of the median, ulnar and radial nerve (r = -0.84; p = 0.002 and r = -0.68; p = 0.032). Both FA and hsTNT further showed correlations with items of the Michigan Hand Outcome Questionnaire (r = -0.76; p = 0.010 and r = 0.87; p = 0.001, respectively). A negative correlation was found for hsTNT and HbA1c with the total Purdue Pegboard Test Score (r = -0.87; p = 0.001 and r = -0.68; p = 0.031).ConclusionThis study is the first to find that hsTNT and HbA1c are associated with functional and structural parameters of the nerves at the level of the upper limbs in patients with impaired glucose tolerance and T2D. Our results support the hypothesis that hyperglycemia-related microangiopathy, represented by elevated hsTNT levels, is a contributor to nerve damage in diabetic polyneuropathy

A scavenger peptide prevents methylglyoxal induced pain in mice.

The reactive metabolite methylglyoxal (MG) has been identified as mediator of pain. Scavenging of free MG and the prevention of MG-derived post-translational modifications may provide a useful therapeutic treatment. An arginine-rich, fatty acid coupled, cyclic peptide (CycK(Myr)R4E) with high proteolytic stability and prolonged circulation was developed for the scavenging of MG. It was shown to reduce the formation of albumin-MG adducts in vitro and prevented MG-induced pain by reducing plasma MG levels through the formation of peptide-MG adducts in vivo. CycK(Myr)R4E therefore presents a promising option for the treatment of pain and other diabetic complications associated with high MG levels

Diabetic neuropathy is a generalized phenomenon with impact on hand functional performance and quality of life.

BACKGROUND: Diabetic sensorimotor peripheral neuropathy (DSPN) is usually considered to affect predominantly the lower limbs (LL-N), while the impact of upper limb neuropathy (UL-N) on hand functional performance and quality of life (QoL) has not been evaluated systematically. This study aims to investigate the prevalence and characteristics of UL-N and its functional and psychosocial consequences in type 2 diabetes. METHODS: Individuals with type 2 diabetes (n=141) and an age- and sex-matched control group (n=73) underwent comprehensive assessment of neuropathy, hand functional performance and psychosocial status. RESULTS: The prevalence of UL-N was 30.5% in patients with diabetes and that of LL-N 49.6%, with 25.5% exhibiting both. Patients with diabetes showed similar sensory phenotype regarding both large and small fiber functions in hands and feet. Patients with UL-N showed reduced manual dexterity, but normal hand grip force. Additionally, there was a correlation between reduced dexterity and sensory deficits. Patients with UL-N had reduced estimates of psychosocial health including health-related QoL compared to control subjects and patients without UL-N. UL-N correlated with the severity of LL-N, but not with duration of diabetes, glycaemia, age, or sex. CONCLUSIONS: This study points to a substantial prevalence of UL-N in type 2 diabetes. The sensory phenotype of patients with UL-N was similar to LL-N and was characterized by loss of sensory function. Our study demonstrated an association of UL-N with impaired manual dexterity and reduced health-related QoL. Thus, upper limb sensorimotor functions should be assessed early in patients with diabetes