The chronic stress risk phenotype mirrored in the human retina as a neurodegenerative condition.

The brain is the key organ that orchestrates the stress response which translates to the retina. The retina is an extension of the brain and retinal symptoms in subjects with neurodegenerative diseases substantiated the eye as a window to the brain. The retina is used in this study to determine whether chronic stress reflects neurodegenerative signs indicative of neurodegenerative conditions. A three-year prospective cohort (n = 333; aged 46 ± 9 years) was stratified into stress-phenotype cases (n = 212) and controls (n = 121) by applying the Malan stress-phenotype index. Neurodegenerative risk markers included ischemia (astrocytic S100 calcium-binding protein B/S100B); 24-h blood pressure, proteomics; inflammation (tumor-necrosis-factor-α/TNF-α); neuronal damage (neuron-specific-enolase); anti-apoptosis of retinal-ganglion-cells (beta-nerve-growth-factor), astrocytic activity (glial-fibrillary-acidic-protein); hematocrit (viscosity) and retinal follow-up data [vessels; stress-optic-neuropathy]. Stress-optic-neuropathy risk was calculated from two indices: a newly derived diastolic-ocular-perfusion-pressure cut-point ≥68 mmHg relating to the stress-phenotype; combined with an established cup-to-disk ratio cut-point ≥0.3. Higher stress-optic-neuropathy (39% vs. 17%) and hypertension (73% vs. 16%) prevalence was observed in the stress-phenotype cases vs. controls. Elevated diastolic-ocular-perfusion-pressure, indicating hypoperfusion, was related to arterial narrowing and trend for ischemia increases in the stress-phenotype. Ischemia in the stress-phenotype at baseline, follow-up and three-year changes was related to consistent inflammation (TNF-α and cytokine-interleukin-17-receptor-A), neuron-specific-enolase increases, consistent apoptosis (chitinase-3-like protein 1, low beta-nerve-growth-factor), glial-fibrillary-acidic-protein decreases, elevated viscosity, vein widening as risk marker of endothelial dysfunction in the blood-retinal barrier, lower vein count, and elevated stress-optic-neuropathy. The stress-phenotype and related neurodegenerative signs of ongoing brain ischemia, apoptosis and endothelial dysfunction compromised blood-retinal barrier permeability and optic nerve integrity. In fact, the stress-phenotype could identify persons at high risk of neurodegeneration to indicate a neurodegenerative condition.

Molecular characterization of hepatitis B virus isolated from Black South African cancer patients, with and without hepatocellular carcinoma.

In South Africa (SA), hepatitis B virus (HBV) infection is strongly associated with hepatocellular carcinoma (HCC). As HBV genotypes/subgenotypes and mutations can influence disease manifestation and progression, our aim was to molecularly characterize HBV in Black cancer patients, with and without HCC. The basal core promoter/precore (BCP/PC) and complete surface (S) regions of HBV isolates were amplified and sequenced from 55 HCC cases and 22 non-HCC cancer controls. Phylogenetic analysis of 43 polymerase/complete S region amplicons showed that the majority (88.4%) clustered with subgenotype A1, 4.7% with A2, and 7% with A3. The following mutations were significantly more frequent in HCC cases than in controls (p < 0.05): in the BCP/PC 1753C/G (22.5% vs. 0%), 1764A (69.4% vs. 38.1%), and T64C (51.5% vs. 20%) in the preS2, which results in a F22L substitution. PreS1 and preS2 start codon mutants were detected only in HCC cases, occurring in two and 16 isolates, respectively. PreS deletion mutants were isolated from 11 HCC cases, which had a HBV viral load > 10,000 IU/mL and were significantly younger than non-HCC controls (34 ± 7.1 vs. 41.2 ± 9.5 years, p = 0.05). The 1762T/1764A double mutation was detected in the majority (90.9%) of the isolates from HCC cases with preS deletions. Black HBV carriers were mainly infected with subgenotype A1, with HCC cases carrying BCP/PC and preS mutant strains that are associated with hepatocarcinogenesis. This is the first study to compare the molecular characteristics of HBV from HCC and non-HCC cancer patients in SA.

Liver cancer mortality trends in South Africa: 1999-2015.

BACKGROUND: In South Africa (SA), liver cancer (LC) is a public health problem and information is limited. METHODS: Joinpoint regression analysis was computed for the most recent LC mortality data from Statistics South Africa (StatsSA), by age group, sex and population group. The mortality-to-incidence ratios (MIRs) were calculated as the age-adjusted mortality rate divided by the age-adjusted incidence rate. RESULTS: From 1999 to 2015, the overall LC mortality significantly decreased in men (- 4.9%) and women (- 2.7%). Overall a significant decrease was noted in black African men aged 20-29 and 40-49 years, and white women older than 60 years but mortality rates increased among 50-59 and 60-69 year old black African men (from 2010/2009-2015) and women (from 2004/2009-2015). The mortality rates increased with age, and were higher among blacks Africans compared to whites in all age groups - with a peak black African-to-white mortality rate ratio of six in men and three in women at ages 30-39 years. The average MIR for black African men and women was 4 and 3.3 respectively, and 2.2 and 1.8 in their white counterparts. Moreover, decreasing LC mortality rates among younger and the increase in rates in older black Africans suggest that the nadir of the disease may be near or may have passed. CONCLUSIONS: Findings of population-age subgroup variations in LC mortality and the number of underdiagnosed cases can inform surveillance efforts, while more extensive investigations of the aetiological risk factors are needed. IMPACT: There was a large race, sex and age differences in trends of LC mortality in SA. These findings should inform more extensive evaluation of the aetiology and risk factors of LC in the country in order to guide control efforts.

Enzyme Kinetics Analysis: An online tool for analyzing enzyme initial rate data and teaching enzyme kinetics.

Enzymes are nature's catalysts, mediating chemical processes in living systems. The study of enzyme function and mechanism includes defining the maximum catalytic rate and affinity for substrate/s (among other factors), referred to as enzyme kinetics. Enzyme kinetics is a staple of biochemistry curricula and other disciplines, from molecular and cellular biology to pharmacology. However, because enzyme kinetics involves concepts rarely employed in other areas of biology, it can be challenging for students and researchers. Traditional graphical analysis was replaced by computational analysis, requiring another skill not core to many life sciences curricula. Computational analysis can be time-consuming and difficult in free software (e.g., R) or require costly software (e.g., GraphPad Prism). We present Enzyme Kinetics Analysis (EKA), a web-tool to augment teaching and learning and streamline EKA. EKA is an interactive and free tool for analyzing enzyme kinetic data and improving student learning through simulation, built using R and RStudio's ShinyApps. EKA provides kinetic models (Michaelis-Menten, Hill, simple reversible inhibition models, ternary-complex, and ping-pong) for users to fit experimental data, providing graphical results and statistics. Additionally, EKA enables users to input parameters and create data and graphs, to visualize changes to parameters (e.g., K M or number of measurements). This function is designed for students learning kinetics but also for researchers to design experiments. EKA (enzyme-kinetics.shinyapps.io/enzkinet_webpage/) provides a simple, interactive interface for teachers, students, and researchers to explore enzyme kinetics. It gives researchers the ability to design experiments and analyze data without specific software requirements.

Deciphering m6A dynamics at a single-base level during planarian anterior-posterior axis specification.

Background: The establishment of the anterior-posterior (A-P) axis is a crucial step during tissue repair and regeneration. Despite the association reported recently of N6-methyladenosine (m6A) with regeneration, the mechanism underlying the regulation of m6A in A-P axis specification during regeneration remains unknown. Herein, we deciphered the m6A landscape at a single-base resolution at multiple time points during A-P axis regeneration and constructed the de novo transcriptome assembly of the Dugesia japonica planarian. Results: Immunofluorescence staining and comparative analysis revealed that m6A is widespread across the planarian and dynamically regulated during regeneration along the A-P axis, exhibiting a strong spatiotemporal feature. The resulting datasets of m6A-modified genes identified 80 anterior-specific genes and 13 posterior-specific genes, respectively. In addition, we showed that YTHDC1 serves as the primary m6A reader to be involved in the m6A-mediated specification of A-P axis during regeneration in Dugesia japonica planarian. Conclusions: Our study provides an RNA epigenetic explanation for the specification of the A-P axis during tissue regeneration in planarian.

Systematic comparison of tools used for m6A mapping from nanopore direct RNA sequencing.

N6-methyladenosine (m6A) has been increasingly recognized as a new and important regulator of gene expression. To date, transcriptome-wide m6A detection primarily relies on well-established methods using next-generation sequencing (NGS) platform. However, direct RNA sequencing (DRS) using the Oxford Nanopore Technologies (ONT) platform has recently emerged as a promising alternative method to study m6A. While multiple computational tools are being developed to facilitate the direct detection of nucleotide modifications, little is known about the capabilities and limitations of these tools. Here, we systematically compare ten tools used for mapping m6A from ONT DRS data. We find that most tools present a trade-off between precision and recall, and integrating results from multiple tools greatly improve performance. Using a negative control could improve precision by subtracting certain intrinsic bias. We also observed variation in detection capabilities and quantitative information among motifs, and identified sequencing depth and m6A stoichiometry as potential factors affecting performance. Our study provides insight into the computational tools currently used for mapping m6A based on ONT DRS data and highlights the potential for further improving these tools, which may serve as the basis for future research.

Evaluating a standardized protocol for the management of diabetes insipidus in pediatric neurosurgical patients.

OBJECTIVES: Central diabetes insipidus (DI) is a known complication following surgical resection of a suprasellar mass. There are limited data analyzing the outcomes of a standardized protocol for the management of postoperative DI in the pediatric population. We sought to fill this gap and hypothesized that utilizing a standardized protocol for fluid management (3-bag system) would reduce serum sodium fluctuations in the postoperative period after suprasellar surgery. METHODS: A retrospective chart review was performed. Patients were identified with the following criteria: age ≤ 18 years, undergoing a surgical procedure for suprasellar mass that also had postoperative DI. The primary outcome was the variability in serum sodium during the first 48 h and between 48 and 120 h postoperatively. RESULTS: There were 21 encounters pre-protocol and 22 encounters post-protocol for neurosurgical procedures. Use of the standardized protocol was associated with a lower range of sodium within 48 h postoperatively (p=0.065) and 83% lower odds of hypernatremia (Na>150 mmol/L) within 48 h postoperatively (CI 0.039-0.714) after controlling for age, gender, and prior DI diagnosis. History of DI conferred a lower risk of hypernatremia as well as less sodium fluctuation within 48 h postoperatively. Younger patients, those <9.7 years of age were associated with increased risk of hyponatremia and greater sodium fluctuations during the postoperative period. CONCLUSIONS: In patients with postoperative DI after suprasellar surgery, using a standardized protocol for fluid management (3-bag system) appears to reduce serum sodium variability in the first 48 h after surgery.

Obesity, but not glycemic control, predicts liver steatosis in children with type 1 diabetes.

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD), the most common liver disease in children, is strongly associated with obesity and insulin resistance. Although type 1 diabetes (T1D) is characterized by insulin deficiency, increasing obesity rates among children with T1D is a major risk factor for NAFLD in this patient population. Predisposing factors for NAFLD in children with T1D are not known. STUDY DESIGN: This is a cross-sectional study comparing children with T1D across the range of body mass index (BMI) to the BMI-matched obese group without T1D. Hepatic steatosis was semi-quantitatively measured via the vibration-controlled transient elastogram (VCTE) method. Linear regression analysis was performed to assess the relationship between controlled-attenuated parameter (CAP) scores and clinical parameters. Receiver-operator curve (ROC) analysis was used to evaluate the diagnostic performance of several clinical parameters against NAFLD status determined via CAP. RESULTS: Two-thirds of subjects with obesity had CAP scores suggestive of NAFLD, while 16 % (n = 6) of T1D patients without obesity had elevated CAP. Obese subjects were different from non-obese subjects in many laboratory and clinical characteristics, regardless of T1D status. CAP score was significantly associated with BMI, HDL-Cholesterol (HDL-c), and HbA1c in all subjects as well as the T1D-only subgroup. Among subjects with obesity only, age, HDL-cand ALT were the most significant predictors. Diagnostic performance of BMI, HDL-c, and BMI/HDL ratio were in the good to the excellent range for predicting NAFLD among all subjects, while performance varied for T1D-only or obesity-only groups. CONCLUSION: The clinical and imaging findings of children with T1D and obesity are comparable to non-diabetic children with a similar degree of obesity. Obesity is the major risk factor for NAFLD in pediatric T1D. BMI, HDL-c, and BMI/HDL ratio may be helpful markers to determine further workup for NAFLD in children with T1D, particularly those with obesity.

Capillaric field effect transistors.

Controlling fluid flow in capillaric circuits is a key requirement to increase their uptake for assay applications. Capillary action off-valves provide such functionality by pushing an occluding bubble into the channel using a difference in capillary pressure. Previously, we utilized the binary switching mode of this structure to develop a powerful set of fundamental fluidic valving operations. In this work, we study the transistor-like qualities of the off-valve and provide evidence that these structures are in fact functionally complementary to electronic junction field effect transistors. In view of this, we propose the new term capillaric field effect transistor to describe these types of valves. To support this conclusion, we present a theoretical description, experimental characterization, and practical application of analog flow resistance control. In addition, we demonstrate that the valves can also be reopened. We show modulation of the flow resistance from fully open to pinch-off, determine the flow rate-trigger channel volume relationship and demonstrate that the latter can be modeled using Shockley's equation for electronic transistors. Finally, we provide a first example of how the valves can be opened and closed repeatedly.

High-precision mapping reveals rare N6-deoxyadenosine methylation in the mammalian genome.

N6-deoxyadenosine methylation (6mA) is the most widespread type of DNA modification in prokaryotes and is also abundantly distributed in some unicellular eukaryotes. However, 6mA levels are remarkably low in mammals. The lack of a precise and comprehensive mapping method has hindered more advanced investigations of 6mA. Here, we report a new method MM-seq (modification-induced mismatch sequencing) for genome-wide 6mA mapping based on a novel detection principle. We found that modified DNA bases are prone to form a local open region that allows capture by antibody, for example, via a DNA breathing or base-flipping mechanism. Specified endonuclease or exonuclease can recognize the antibody-stabilized mismatch-like structure and mark the exact modified sites for sequencing readout. Using this method, we examined the genomic positions of 6mA in bacteria (E. coli), green algae (C. reinhardtii), and mammalian cells (HEK239T, Huh7, and HeLa cells). In contrast to bacteria and green algae, human cells possess a very limited number of 6mA sites which are sporadically distributed across the genome of different cell types. After knocking out the RNA m6A methyltransferase METTL3 in mouse ES cells, 6mA becomes mostly diminished. Our results imply that rare 6mA in the mammalian genome is introduced by RNA m6A machinery via a non-targeted mechanism.

Review of Insulin Resistance in Dilated Cardiomyopathy and Implications for the Pediatric Patient Short Title: Insulin Resistance DCM and Pediatrics.

Energy metabolism in the heart is affected during states of dysfunction. Understanding how the heart utilizes substrates in cardiomyopathy may be key to the development of alternative treatment modalities. Myocardial insulin resistance has been proposed as a possible barrier to effective glucose metabolism in the heart. Extensive literature on the topic in adult individuals exists; however, review in the pediatric population is sparse. The pathophysiology of disease in children and adolescents is unique. The aim of this paper is to review the current knowledge on insulin resistance in dilated cardiomyopathy while also filling the gap when considering care in the pediatric population.

SARS-CoV-2 infection and paediatric endocrine disorders: Risks and management considerations.

Background: Coronavirus-19 (COVID-19) is a disease caused by the SARS-CoV-2 virus, the seventh coronavirus identified as causing disease in humans. The SARS-CoV-2 virus has multiple potential pathophysiologic interconnections with endocrine systems, potentially causing disturbances in glucose metabolism, hypothalamic and pituitary function, adrenal function and mineral metabolism. A growing body of data is revealing both the effects of underlying endocrine disorders on COVID-19 disease outcome and the effects of the SARS-CoV-2 virus on endocrine systems. However, comprehensive assessment of the relationship to endocrine disorders in children has been lacking. Content: In this review, we present the effects of SARS-CoV-2 infection on endocrine systems and review the current literature on complications of COVID-19 disease in underlying paediatric endocrine disorders. We provide recommendations on management of endocrinopathies related to SARS-CoV-2 infection in this population. Summary and outlook: With the surge in COVID-19 cases worldwide, it is important for paediatric endocrinologists to be aware of the interaction of SARS-CoV-2 with the endocrine system and management considerations for patients with underlying disorders who develop COVID-19 disease. While children and adults share some risk factors that influence risk of complications in SARS-CoV-2 infection, it is becoming clear that responses in the paediatric population are distinct and outcomes from adult studies cannot be extrapolated. Evidence emerging from paediatric studies provides some guidance but highlights the need for more research in this area.

Consensus statements on the clinical understanding and use of bupropion in Hong Kong.

OBJECTIVES: To develop a local consensus to guide medical practitioners and psychiatrists on the use of bupropion in different psychiatric conditions in Hong Kong. METHODS: By utilizing the modified Delphi technique, a group of 10 local physicians with extensive experience in the management of major depressive disorder (MDD) developed and voted (using an anonymous, electronic voting system) on the practicality of recommendation of a set of consensus statements on the clinical use and understanding of bupropion in Hong Kong. RESULTS: There was a very high degree of agreement among the panelists on the 11 finalized consensus statements. CONCLUSIONS: The present consensus statements are developed as general recommendations for medical practitioners and psychiatrists to be practically referred to in clinical settings.

Achieving better outcomes for schizophrenia patients in Hong Kong: Strategies for improving treatment adherence.

Recent research on second-generation long-acting injectable antipsychotics (LAI SGAs) has proven its effectiveness in minimizing medication nonadherence problem and reducing relapses. Administered by medical professionals, making quick detection of nonadherence possible, long-acting injectable antipsychotics (LAIs) facilitate immediate intervention and recovery process, and thus are favored by psychiatrists. Despite a higher initial cost with LAIs, the subsequent schizophrenia-related health costs for hospitalizations and outpatients are greatly reduced. With reference to guidelines published by psychiatric associations around the globe, this article looks at scenarios in Hong Kong on the management of severe mentally ill patients with regard to the use of a host of psychosocial interventions as well as LAI SGAs as a preferable treatment. In particular, it examines the benefits of using LAI SGAs for Hong Kong patients who demonstrated high nonadherence treatment rates due to their social environment. It assesses the rationale behind the early usages of LAI SGAs, which help to provide better recovery outcomes for patients.

Centrosome-associated CDC25B is a novel disease-causing gene for a syndrome with cataracts, dilated cardiomyopathy, and multiple endocrinopathies.

We describe a unique Chinese girl who presented with intrauterine growth retardation, delayed development, bilateral cataracts, hypothyroidism, growth hormone deficiency, and juvenile dilated cardiomyopathy. She was born to consanguineous parents with a history of one fetal and one infantile death in the family. She died from cardiac failure at the age of 12. In the pursuit of a diagnosis, the family was referred to the Clinics for Rare Diseases Referral and the University of Hong Kong Undiagnosed Disease Program. Whole-exome sequencing analysis revealed a homozygous non-sense variant, NM_021873:c.313G > T (p.Glu105*), in the CDC25B gene, a key regulator of the cell cycle. This variant was located in a region of homozygosity of 25 Mb on chromosome 20. Her parents and two asymptomatic sisters were confirmed to be carriers and one brother did not carry the variant. This is the first report of a natural human knockout of the CDC25B gene. Multiple endocrinopathies and fatal juvenile dilated cardiomyopathy suggests the potential for unfavorable complications in oncology patients receiving CDC25B inhibitors as an emerging targeted therapy.

Production of Paralytic Shellfish Toxins (PSTs) in Toxic Alexandrium catenella is Intertwined with Photosynthesis and Energy Production.

To investigate the mechanism for the production of paralytic shellfish toxins (PST) in toxic dinoflagellates, with a 2D-gel based approach, we had made two sets of proteomic comparisons: (a) between a toxic Alexandrium catenella (AC-T) and a phylogenetically closely related non-toxic strain (AC-N), (b) between toxic AC-T grown in a medium with 10% normal amount of phosphate (AC-T-10%P) known to induce higher toxicity and AC-T grown in normal medium. We found that photosynthesis and energy production related proteins were up-regulated in AC-T when compared to AC-N. However, the same group of proteins was down-regulated in AC-T-10%P when compared to normal AC-T. Examining the relationship of photosynthesis and toxin content of AC-T upon continuous photoperiod experiment revealed that while growth and associated toxin content increased after 8 days of continuous light, toxin content maintained constant when cells were shifted from continuous light to continuous dark for 3 days. This emphasized the cruciality of light availability on toxin biosynthesis in AC-T, while another light-independent mechanism may be responsible for higher toxicity in AC-T-10%P compared to normal AC-T. Taken all together, it is believed that the interplay between "illumination", "photosynthesis", "phosphate availability", and "toxin production" is much more complicated than what we had previously anticipated.

Analysis of risk factors associated with hepatocellular carcinoma in black South Africans: 2000-2012.

OBJECTIVE: The aims of this study were to determine the prevalence of risk factors associated with hepatocellular carcinoma (HCC) in black adult South Africans and to estimate the size of the associated risks. METHODS: A case-control analysis of 150 black South African patients (aged 18-75 years) with HCC-who were a subset of patients recruited for the Johannesburg Cancer Case Control Study 2000 to 2012-was undertaken. The association between this tumour and hepatitis B/C virus infections, and human immunodeficiency virus (HIV) mono- and co-infections was investigated. Odds ratios (ORs) and 95% confidence intervals (CI) adjusted for age, year of diagnosis, marital status, place of birth and selected modifiable risk factors were calculated. RESULTS: HCC was significantly associated with a rural birthplace (p<0.05), being male and living in an urban area for 14 years or less. The Odds Ratio (OR) for HCC increased significantly with HBV DNA+/HBsAg+ (OR 34.5; CI:16.26-73.13), HBV DNA+/HBsAg- (OR 3.76; CI:1.79-7.92), HBV DNA level >2000 IU/ml (OR 8.55; CI:3.00-24.54) to ≥200,000 (OR 16.93; CI:8.65-33.13), anti-HCV (OR 8.98; CI:3.59-22.46), HBV DNA+/HIV+ co-infection (OR 5.36; CI:2.59-11.11), but not with HBV DNA-/HIV+ (OR 0.34; CI:0.14-0.85). We did not find a synergistic interaction between HBV and HIV. Modifiable risk factors (alcohol consumption, tobacco smoking, number of sexual partners, diabetes and hormonal contraceptive use) were nonsignificant. DISCUSSION: A considerable portion of the HCC burden in Johannesburg and surrounding provinces falls on rural migrants to urban areas, most of whom are men. The HBV will continue to contribute to HCC incidence in older age-groups and in others who missed vaccination. Although we did not find an increased risk for HCC in HIV positive individuals this may change as life expectancy increases due to greater access to antiretroviral therapies, necessitating the addition of hepatitis virus screening to preventive medical care.

Novel model of calcium and inositol 1, 4, 5-trisphosphate regulation of InsP3 receptor channel gating in native endoplasmic reticulum

The InsP3R Ca2+-release channel has biphasic dependence on cytoplasmic free Ca2+ concentration ([Ca2+]i). InsP3 activates gating primarily by reducing high [Ca2+]i inhibition. To determine whether relieving Ca2+ inhibition is sufficient for activation, we examined single-channels in low [Ca2+]i in the absence of InsP3 by patch clamping isolated Xenopus oocyte nuclei. For both endogenous Xenopus type 1 and recombinant rat type 3 InsP3R channels, spontaneous InsP3-independent activities with low open probability Po (~ 0.03) were observed in [Ca2+]i < 5 nM, whereas none were observed in 25 nM Ca2+. These results establish the half-maximal inhibitory [Ca2+]i in the absence of InsP3 and demonstrate that the channel can be active when all of its ligand-binding sites are unoccupied. In the simplest allosteric model that fits all observations in nuclear patch-clamp studies, the tetrameric channel can adopt six conformations, the equilibria among which are controlled by two inhibitory, one activating Ca2+-binding, and one InsP3-binding sites in a manner similar to the Monod-Wyman-Changeux model. InsP3 binding activates gating by affecting the relative affinity for Ca2+ of one of the inhibitory sites in different channel conformations, transforming it into an activating site. Ca2+ inhibition of InsP3-liganded channels is mediated by an InsP3-independent second inhibitory site.