Test–retest repeatability of [18F]Flortaucipir PET in Alzheimer’s disease and cognitively normal individuals

The aim of this study was to investigate the test–retest (TRT) repeatability of various parametric quantification methods for [¹⁸F]Flortaucipir positron emission tomography (PET). We included eight subjects with dementia or mild cognitive impairment due to Alzheimer’s disease and six cognitively normal subjects. All underwent two 130-min dynamic [¹⁸F]Flortaucipir PET scans within 3 ± 1 weeks. Data were analyzed using reference region models receptor parametric mapping (RPM), simplified reference tissue method 2 (SRTM2) and reference logan (RLogan), as well as standardized uptake value ratios (SUVr, time intervals 40–60, 80–100 and 110–130 min post-injection) with cerebellar gray matter as reference region. We obtained distribution volume ratio or SUVr, first for all brain regions and then in three tau-specific regions-of-interest (ROIs). TRT repeatability (%) was defined as |retest–test|/(average (test + retest)) × 100. For all methods and across ROIs, TRT repeatability ranged from (median (IQR)) 0.84% (0.68–2.15) to 6.84% (2.99–11.50). TRT repeatability was good for all reference methods used, although semi-quantitative models (i.e. SUVr) performed marginally worse than quantitative models, for instance TRT repeatability of RPM: 1.98% (0.78–3.58) vs. SUVr_80–100: 3.05% (1.28–5.52), p < 0.001. Furthermore, for SUVr_80–100 and SUVr_110–130, with higher average SUVr, more variation was observed. In conclusion, while TRT repeatability was good for all models used, quantitative methods performed slightly better than semi-quantitative methods.     

Is there a best approach for extracorporeal life support cannulation: a review of the extracorporeal life support organization

Background

Neurologic complications are common, and amongst the most devastating complications in pediatric patients undergoing extracorporeal life support (ECLS). Carotid artery cannulation (CAN) has been associated with an increase in these complications, thereby shaping practices to avoid this approach in most pediatric patients in which other cannulation approaches are viable.

Interaction Behaviors of Bilingual Parents With Their Young Children With Autism Spectrum Disorder

Given concerns that bilingual exposure might confuse children with disabilities—including autism spectrum disorder (ASD)—bilingual parents may restrict exposure to one language, often the community-dominant language. We investigated a potential consequence of this decision; the possibility that non-native language use might influence parental communicative behaviors during interaction with the child. We recruited 39 parent–child dyads, each with a young child with ASD (mostly boys) and parent/carer (mostly mothers). Parents were either monolingual speakers of community-dominant English (n = 20) or bilingual with English as the second language (n = 19). We confirmed our assumption that the latter group would have significantly poorer non-native English language via standardized assessment of expressive vocabulary, and ensured children were matched on age, ASD symptoms, and developmental level. We sampled parent–child interaction—including in each of bilinguals’ native and non-native languages—and coded parents’ amount and complexity of speech, communicative synchrony, and imitations and expansions of their child’s speech. Few differences presented across bilingual parents’ native versus non-native language samples, but this group showed reduced synchrony and use of expansions compared to monolinguals. Further, bilinguals’ English-language knowledge was associated with self-reported comfort using this language and with two coded interaction measures. These empirical data only partially support qualitative accounts that non-native language use may influence bilingual parents’ interaction behaviors with their young children. With growing rates of ASD diagnosis and increasing cultural/linguistic diversity around the world, further dedicated clinical and experimental attention to this issue is clearly warranted.     

Age- and gender-related differences in the evolution of psychological and cognitive status after the lockdown for the COVID-19 outbreak: a follow-up study

Neurological Sciences - Individuals experienced psychological symptoms in response to quarantine for&nbsp;the COVID-19 pandemic. Therefore, we aimed to investigate the possible effect of age...     

Sentinel lymph node biopsy in melanoma: Which hot nodes should be harvested and is blue dye really necessary?

Objectives

The ‘10% rule’ has become widely accepted by surgeons performing sentinel lymph node biopsy (SLNB) for melanoma. The purpose of this study was to compare the ‘10% rule’ with alternative node harvesting criteria. In particular, we were interested to see whether the use of blue dye had any impact on the sensitivity of the test and whether it is necessary to remove all hot nodes.

Mapping the organization of atrial fibrillation with basket catheters. Part II: Regional patterns in chronic patients

The aim of this study was to investigate the spatial patterns of organization of fibrillation in the right atrium using bipolar recordings from a basket catheter in a population of 17 patients with persistent AF. The number of occurrences (NO) (i.e., the number of points laying on the baseline) was used as an objective measure of organization. This parameter significantly matches Wells' criteria for the classification of bipolar recordings during AF. The anatomic correspondence of the splines with eight atrial regions (namely anterior free wall, lateral free wall, posterolateral free wall, posterior free wall, posterior atrial septum, atrial septum, tricuspid valve, and anterior tricuspid valve) was assessed by fluoroscopic projections and electrogram morphology. Each region was further divided into high, mid-high, mid-low, and low segments. It was observed that individual and well-defined patterns of organization characterize the electrical activity of the right atrium in patients with persistent AF. When observed over 10 minutes, these patterns are rather stable in time. In each patient, the NO measurements were significantly different in the various right atrium regions (P < 0.0001 for all patients, Friedman test). The NO averaged over the population was significantly different among the regions (P < 0.001, Kruskal-Wallis test), owing to a common disorganized pattern observed in the tricuspid valve and anterior tricuspid valve regions. When these regions were removed from the analysis, the differences among the remaining regions were not statistically significant (P = 0.77). In conclusion, the quantitative assessment of organization in the entire right atrium showed an individual rather than common distribution. This may have implications in the choice of regions candidate for ablation.     

Fundamentals about onset and progressive disease character of type 2 diabetes mellitus

ResearchGate is a world wide web for scientists and researchers to share papers, ask and answer questions, and find collaborators. As one of the more than 15 million members, the author uploads research output and reads and responds to some of the questions raised, which are related to type 2 diabetes. In that way, he noticed a serious gap of knowledge of this disease among medical professionals over recent decades. The main aim of the current study is to remedy this situation through providing a comprehensive review on recent developments in biochemistry and molecular biology, which can be helpful for the scientific understanding of the molecular nature of type 2 diabetes. To fill up the shortcomings in the curricula of medical education, and to familiarize the medical community with a new concept of the onset of type 2 diabetes, items are discussed like: Insulin resistance, glucose effectiveness, insulin sensitivity, cell membranes, membrane flexibility, unsaturation index (UI; number of carbon-carbon double bonds per 100 acyl chains of membrane phospholipids), slow-down principle, effects of temperature acclimation on phospholipid membrane composition, free fatty acids, energy transport, onset of type 2 diabetes, metformin, and exercise. Based on the reviewed data, a new model is presented with proposed steps in the development of type 2 diabetes, a disease arising as a result of a hypothetical hereditary anomaly, which causes hyperthermia in and around the mitochondria. Hyperthermia is counterbalanced by the slow-down principle, which lowers the amount of carbon-carbon double bonds of membrane phospholipid acyl chains. The accompanying reduction in the UI lowers membrane flexibility, promotes a redistribution of the lateral pressure in cell membranes, and thereby reduces the glucose transporter protein pore diameter of the transmembrane glucose transport channel of all Class I GLUT proteins. These events will set up a reduction in transmembrane glucose transport. So, a new blood glucose regulation system, effective in type 2 diabetes and its prediabetic phase, is based on variations in the acyl composition of phospholipids and operates independent of changes in insulin and glucose concentration. UI assessment is currently arising as a promising analytical technology for a membrane flexibility analysis. An increase in mitochondrial heat production plays a pivotal role in the existence of this regulation system.     

Cutaneous nerve transection for the management of intractable upper extremity pain caused by invasive squamous cell carcinoma

A recurrent clinical dilemma in the management of patients with painful metastatic lesions is achieving a balance between effective analgesic therapies versus intolerable side effects, in particular altered mental status. We present the case of an immunosuppressed patient post-lung transplant who was suffering from intractable pain caused by widely metastatic squamous cell carcinoma. The patient's progressive, excruciating neuropathic pain was localized to the area of the left wrist and forearm. Additionally, the patient complained of moderate pain at sites of tumor involvement on her right arm and scalp. Attempts to adequately manage her left upper extremity pain included a combination of pharmacologic treatments intended to treat neuropathic pain (gabapentin, SNRI, ketamine, opioids) and focused regional analgesia (infraclavicular infusion of local anesthetic). However, the patient developed intolerable side effects including altered mental status and delirium associated with the systemic agents and suboptimal control with the infraclavicular infusion. Given that the most severe pain was well localized, we undertook a diagnostic block of the cutaneous nerves of the left forearm. As this intervention significantly reduced her pain, we subsequently performed neurectomies to the left superficial radial nerve, lateral cutaneous nerve of the forearm and the posterior cutaneous nerve of the forearm. This resulted in immediate and continued relief of her left upper extremity pain without an altered mental status. Residual focal pain from lesions over her right arm and scalp was successfully managed with daily topical applications of lidocaine and capsaicin cream. Successful pain control continued until the patient's death five months later.