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We tested the squatty potty to find the best toilet pose

Is toilet squatting really better than just sitting, or are the supposed benefits of a squatty potty just the fantasy of a rainbow-pooping unicorn?




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We may have spotted a parallel universe going backwards in time

Strange particles observed by an experiment in Antarctica could be evidence of an alternative reality where everything is upside down




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Potbelly postpones quarterly filing due to COVID-19 crisis

Potbelly Corp said on Friday it is unable to file its quarterly report with the U.S. SEC by the May 8 deadline due to the COVID-19 crisis, adding to the restaurant chain's pandemic-led woes.




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Free milk and potatoes in the U.S. to avoid waste

In Washington State and Boston, two initiatives are helping prevent potatoes from being thrown out and milk from being poured down the drain. Gavino Garay has more.




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Harry Potter himself reads...Harry Potter

Daniel Radcliffe joins a slew of celebrities to read Harry Potter at home during lockdown. Emer McCarthy reports.




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BCG vaccine being trialled as potential protection against covid-19

A long-standing hypothesis suggests the BCG vaccine also serves to generally enhance the immune system, meaning it could protect against covid-19, and trials are under way to find out




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We know the best spots to look for alien life – can we get to them?

Extraterrestrial oceans are an obvious place to search for alien life, but getting there and having a look won't be easy, says NASA's Kevin Hand in his book Alien Oceans




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Weird radio signals spotted in our galaxy could solve a space mystery

Weird blasts of radio waves from space called fast radio bursts have been baffling astronomers since they were discovered, but after finding one in our galaxy we may finally know what creates them




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Free milk and potatoes in the U.S. to avoid waste

In Washington State and Boston, two initiatives are helping prevent potatoes from being thrown out and milk from being poured down the drain. Gavino Garay has more.




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Hypothyroidism

Title: Hypothyroidism
Category: Diseases and Conditions
Created: 12/31/1997 12:00:00 AM
Last Editorial Review: 9/18/2019 12:00:00 AM




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Test Spots Potential Organ Donors Among Coma Patients

Title: Test Spots Potential Organ Donors Among Coma Patients
Category: Health News
Created: 4/26/2010 4:10:00 PM
Last Editorial Review: 4/27/2010 12:00:00 AM




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Low Testosterone Raises Heart Death Rates in Impotent Men

Title: Low Testosterone Raises Heart Death Rates in Impotent Men
Category: Health News
Created: 4/29/2010 2:10:00 PM
Last Editorial Review: 4/30/2010 12:00:00 AM




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Quick Screening May Help Spot Autism in Babies

Title: Quick Screening May Help Spot Autism in Babies
Category: Health News
Created: 4/28/2011 10:05:00 AM
Last Editorial Review: 4/28/2011 12:00:00 AM




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Heart Test Spots Sudden Death Risk in Young Athletes

Title: Heart Test Spots Sudden Death Risk in Young Athletes
Category: Health News
Created: 4/27/2012 2:05:00 PM
Last Editorial Review: 4/30/2012 12:00:00 AM




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Scientists Spot How Cox-2 Painkillers Raise Heart Risks

Title: Scientists Spot How Cox-2 Painkillers Raise Heart Risks
Category: Health News
Created: 5/2/2012 4:05:00 PM
Last Editorial Review: 5/3/2012 12:00:00 AM




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Pot-Booze Combo More Dangerous for Teen Drivers Than Alcohol Alone

Title: Pot-Booze Combo More Dangerous for Teen Drivers Than Alcohol Alone
Category: Health News
Created: 4/28/2014 9:35:00 AM
Last Editorial Review: 4/28/2014 12:00:00 AM




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Brain Scans Spot Possible Clues to Chronic Fatigue Syndrome

Title: Brain Scans Spot Possible Clues to Chronic Fatigue Syndrome
Category: Health News
Created: 5/2/2014 12:35:00 PM
Last Editorial Review: 5/2/2014 12:00:00 AM




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Pediatrics Group Advises Doctors on How to Spot Child Abuse

Title: Pediatrics Group Advises Doctors on How to Spot Child Abuse
Category: Health News
Created: 4/27/2015 12:00:00 AM
Last Editorial Review: 4/28/2015 12:00:00 AM




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Health Tip: Spotting Signs of Urinary Tract Infection

Title: Health Tip: Spotting Signs of Urinary Tract Infection
Category: Health News
Created: 5/1/2015 12:00:00 AM
Last Editorial Review: 5/1/2015 12:00:00 AM




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AHA News: Director John Singleton's Fatal Stroke Spotlights Black Americans' Hypertension Risk

Title: AHA News: Director John Singleton's Fatal Stroke Spotlights Black Americans' Hypertension Risk
Category: Health News
Created: 5/2/2019 12:00:00 AM
Last Editorial Review: 5/2/2019 12:00:00 AM




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Device Spots Lymphedema Early in Breast Cancer Patients, to Help Stop It

Title: Device Spots Lymphedema Early in Breast Cancer Patients, to Help Stop It
Category: Health News
Created: 5/2/2019 12:00:00 AM
Last Editorial Review: 5/3/2019 12:00:00 AM




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Legal Pot Products Too Potent for Chronic Pain

Title: Legal Pot Products Too Potent for Chronic Pain
Category: Health News
Created: 3/27/2020 12:00:00 AM
Last Editorial Review: 3/27/2020 12:00:00 AM




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Depressed Pregnant Women 3 Times More Likely to Turn to Pot

Title: Depressed Pregnant Women 3 Times More Likely to Turn to Pot
Category: Health News
Created: 3/12/2020 12:00:00 AM
Last Editorial Review: 3/13/2020 12:00:00 AM




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Necklace Spots A-Fib in Just Over 30 Seconds

Title: Necklace Spots A-Fib in Just Over 30 Seconds
Category: Health News
Created: 5/6/2020 12:00:00 AM
Last Editorial Review: 5/7/2020 12:00:00 AM




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Necklace Spots A-Fib in Just Over 30 Seconds

A necklace outfitted with a high-tech pendant may be able to screen for signs of an abnormal heart rhythm condition known as atrial fibrillation.




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Potato & Sausages, Cold Cuts a Bad Combo for Your Brain

Title: Potato & Sausages, Cold Cuts a Bad Combo for Your Brain
Category: Health News
Created: 4/22/2020 12:00:00 AM
Last Editorial Review: 4/23/2020 12:00:00 AM




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lopinavir and ritonavir (Kaletra): Potential COVID-19 Drug

Title: lopinavir and ritonavir (Kaletra): Potential COVID-19 Drug
Category: Medications
Created: 3/12/2001 12:00:00 AM
Last Editorial Review: 4/8/2020 12:00:00 AM




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Heavy Pot Use Linked to Mental Problems, Even After Quitting

Title: Heavy Pot Use Linked to Mental Problems, Even After Quitting
Category: Health News
Created: 4/30/2020 12:00:00 AM
Last Editorial Review: 5/1/2020 12:00:00 AM




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Low Blood Pressure (Hypotension)

Title: Low Blood Pressure (Hypotension)
Category: Diseases and Conditions
Created: 12/31/1997 12:00:00 AM
Last Editorial Review: 4/14/2020 12:00:00 AM




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'Couch Potato' Lifestyle Poses Danger to Women's Hearts

Title: 'Couch Potato' Lifestyle Poses Danger to Women's Hearts
Category: Health News
Created: 2/18/2020 12:00:00 AM
Last Editorial Review: 2/19/2020 12:00:00 AM




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Pot Use Among U.S. Seniors Nearly Doubled in 3 Years

Title: Pot Use Among U.S. Seniors Nearly Doubled in 3 Years
Category: Health News
Created: 2/24/2020 12:00:00 AM
Last Editorial Review: 2/25/2020 12:00:00 AM




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Welcome to the 'Smart Toilet' That Can Spot Disease

Title: Welcome to the 'Smart Toilet' That Can Spot Disease
Category: Health News
Created: 4/17/2020 12:00:00 AM
Last Editorial Review: 4/17/2020 12:00:00 AM




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azithromycin (Zithromax): Potential COVID-19 Combo Drug

Title: azithromycin (Zithromax): Potential COVID-19 Combo Drug
Category: Medications
Created: 12/31/1997 12:00:00 AM
Last Editorial Review: 3/30/2020 12:00:00 AM




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Using Pot to Help You Sleep? It Could Backfire

Title: Using Pot to Help You Sleep? It Could Backfire
Category: Health News
Created: 4/14/2020 12:00:00 AM
Last Editorial Review: 4/15/2020 12:00:00 AM




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Pharmacologic Inhibitor of DNA-PK, M3814, Potentiates Radiotherapy and Regresses Human Tumors in Mouse Models

Physical and chemical DNA-damaging agents are used widely in the treatment of cancer. Double-strand break (DSB) lesions in DNA are the most deleterious form of damage and, if left unrepaired, can effectively kill cancer cells. DNA-dependent protein kinase (DNA-PK) is a critical component of nonhomologous end joining (NHEJ), one of the two major pathways for DSB repair. Although DNA-PK has been considered an attractive target for cancer therapy, the development of pharmacologic DNA-PK inhibitors for clinical use has been lagging. Here, we report the discovery and characterization of a potent, selective, and orally bioavailable DNA-PK inhibitor, M3814 (peposertib), and provide in vivo proof of principle for DNA-PK inhibition as a novel approach to combination radiotherapy. M3814 potently inhibits DNA-PK catalytic activity and sensitizes multiple cancer cell lines to ionizing radiation (IR) and DSB-inducing agents. Inhibition of DNA-PK autophosphorylation in cancer cells or xenograft tumors led to an increased number of persistent DSBs. Oral administration of M3814 to two xenograft models of human cancer, using a clinically established 6-week fractionated radiation schedule, strongly potentiated the antitumor activity of IR and led to complete tumor regression at nontoxic doses. Our results strongly support DNA-PK inhibition as a novel approach for the combination radiotherapy of cancer. M3814 is currently under investigation in combination with radiotherapy in clinical trials.




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Mycobacterium tuberculosis Reactivates HIV-1 via Exosome-Mediated Resetting of Cellular Redox Potential and Bioenergetics

ABSTRACT

The synergy between Mycobacterium tuberculosis and human immunodeficiency virus-1 (HIV-1) interferes with therapy and facilitates the pathogenesis of both human pathogens. Fundamental mechanisms by which M. tuberculosis exacerbates HIV-1 infection are not clear. Here, we show that exosomes secreted by macrophages infected with M. tuberculosis, including drug-resistant clinical strains, reactivated HIV-1 by inducing oxidative stress. Mechanistically, M. tuberculosis-specific exosomes realigned mitochondrial and nonmitochondrial oxygen consumption rates (OCR) and modulated the expression of host genes mediating oxidative stress response, inflammation, and HIV-1 transactivation. Proteomics analyses revealed the enrichment of several host factors (e.g., HIF-1α, galectins, and Hsp90) known to promote HIV-1 reactivation in M. tuberculosis-specific exosomes. Treatment with a known antioxidant—N-acetyl cysteine (NAC)—or with inhibitors of host factors—galectins and Hsp90—attenuated HIV-1 reactivation by M. tuberculosis-specific exosomes. Our findings uncover new paradigms for understanding the redox and bioenergetics bases of HIV-M. tuberculosis coinfection, which will enable the design of effective therapeutic strategies.

IMPORTANCE Globally, individuals coinfected with the AIDS virus (HIV-1) and with M. tuberculosis (causative agent of tuberculosis [TB]) pose major obstacles in the clinical management of both diseases. At the heart of this issue is the apparent synergy between the two human pathogens. On the one hand, mechanisms induced by HIV-1 for reactivation of TB in AIDS patients are well characterized. On the other hand, while clinical findings clearly identified TB as a risk factor for HIV-1 reactivation and associated mortality, basic mechanisms by which M. tuberculosis exacerbates HIV-1 replication and infection remain poorly characterized. The significance of our research is in identifying the role of fundamental mechanisms such as redox and energy metabolism in catalyzing HIV-M. tuberculosis synergy. The quantification of redox and respiratory parameters affected by M. tuberculosis in stimulating HIV-1 will greatly enhance our understanding of HIV-M. tuberculosis coinfection, leading to a wider impact on the biomedical research community and creating new translational opportunities.




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Defining Stage-Specific Activity of Potent New Inhibitors of Cryptosporidium parvum Growth In Vitro

ABSTRACT

Cryptosporidium parvum and Cryptosporidium hominis have emerged as major enteric pathogens of infants in the developing world, in addition to their known importance in immunocompromised adults. Although there has been recent progress in identifying new small molecules that inhibit Cryptosporidium sp. growth in vitro or in animal models, we lack information about their mechanism of action, potency across the life cycle, and cidal versus static activities. Here, we explored four potent classes of compounds that include inhibitors that likely target phosphatidylinositol 4 kinase (PI4K), phenylalanine-tRNA synthetase (PheRS), and several potent inhibitors with unknown mechanisms of action. We utilized monoclonal antibodies and gene expression probes for staging life cycle development to define the timing of when inhibitors were active during the life cycle of Cryptosporidium parvum grown in vitro. These different classes of inhibitors targeted different stages of the life cycle, including compounds that blocked replication (PheRS inhibitors), prevented the segmentation of daughter cells and thus blocked egress (PI4K inhibitors), or affected sexual-stage development (a piperazine compound of unknown mechanism). Long-term cultivation of C. parvum in epithelial cell monolayers derived from intestinal stem cells was used to distinguish between cidal and static activities based on the ability of parasites to recover from treatment. Collectively, these approaches should aid in identifying mechanisms of action and for designing in vivo efficacy studies based on time-dependent concentrations needed to achieve cidal activity.

IMPORTANCE Currently, nitazoxanide is the only FDA-approved treatment for cryptosporidiosis; unfortunately, it is ineffective in immunocompromised patients, has varied efficacy in immunocompetent individuals, and is not approved in infants under 1 year of age. Identifying new inhibitors for the treatment of cryptosporidiosis requires standardized and quantifiable in vitro assays for assessing potency, selectivity, timing of activity, and reversibility. Here, we provide new protocols for defining which stages of the life cycle are susceptible to four highly active compound classes that likely inhibit different targets in the parasite. We also utilize a newly developed long-term culture system to define assays for monitoring reversibility as a means of defining cidal activity as a function of concentration and time of treatment. These assays should provide valuable in vitro parameters to establish conditions for efficacious in vivo treatment.




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A Solution to Antifolate Resistance in Group B Streptococcus: Untargeted Metabolomics Identifies Human Milk Oligosaccharide-Induced Perturbations That Result in Potentiation of Trimethoprim

ABSTRACT

Adjuvants can be used to potentiate the function of antibiotics whose efficacy has been reduced by acquired or intrinsic resistance. In the present study, we discovered that human milk oligosaccharides (HMOs) sensitize strains of group B Streptococcus (GBS) to trimethoprim (TMP), an antibiotic to which GBS is intrinsically resistant. Reductions in the MIC of TMP reached as high as 512-fold across a diverse panel of isolates. To better understand HMOs’ mechanism of action, we characterized the metabolic response of GBS to HMO treatment using ultrahigh-performance liquid chromatography–high-resolution tandem mass spectrometry (UPLC-HRMS/MS) analysis. These data showed that when challenged by HMOs, GBS undergoes significant perturbations in metabolic pathways related to the biosynthesis and incorporation of macromolecules involved in membrane construction. This study represents reports the metabolic characterization of a cell that is perturbed by HMOs.

IMPORTANCE Group B Streptococcus is an important human pathogen that causes serious infections during pregnancy which can lead to chorioamnionitis, funisitis, premature rupture of gestational membranes, preterm birth, neonatal sepsis, and death. GBS is evolving antimicrobial resistance mechanisms, and the work presented in this paper provides evidence that prebiotics such as human milk oligosaccharides can act as adjuvants to restore the utility of antibiotics.




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Avoiding Drug Resistance by Substrate Envelope-Guided Design: Toward Potent and Robust HCV NS3/4A Protease Inhibitors

ABSTRACT

Hepatitis C virus (HCV) infects millions of people worldwide, causing chronic liver disease that can lead to cirrhosis, hepatocellular carcinoma, and liver transplant. In the last several years, the advent of direct-acting antivirals, including NS3/4A protease inhibitors (PIs), has remarkably improved treatment outcomes of HCV-infected patients. However, selection of resistance-associated substitutions and polymorphisms among genotypes can lead to drug resistance and in some cases treatment failure. A proactive strategy to combat resistance is to constrain PIs within evolutionarily conserved regions in the protease active site. Designing PIs using the substrate envelope is a rational strategy to decrease the susceptibility to resistance by using the constraints of substrate recognition. We successfully designed two series of HCV NS3/4A PIs to leverage unexploited areas in the substrate envelope to improve potency, specifically against resistance-associated substitutions at D168. Our design strategy achieved better resistance profiles over both the FDA-approved NS3/4A PI grazoprevir and the parent compound against the clinically relevant D168A substitution. Crystallographic structural analysis and inhibition assays confirmed that optimally filling the substrate envelope is critical to improve inhibitor potency while avoiding resistance. Specifically, inhibitors that enhanced hydrophobic packing in the S4 pocket and avoided an energetically frustrated pocket performed the best. Thus, the HCV substrate envelope proved to be a powerful tool to design robust PIs, offering a strategy that can be translated to other targets for rational design of inhibitors with improved potency and resistance profiles.

IMPORTANCE Despite significant progress, hepatitis C virus (HCV) continues to be a major health problem with millions of people infected worldwide and thousands dying annually due to resulting complications. Recent antiviral combinations can achieve >95% cure, but late diagnosis, low access to treatment, and treatment failure due to drug resistance continue to be roadblocks against eradication of the virus. We report the rational design of two series of HCV NS3/4A protease inhibitors with improved resistance profiles by exploiting evolutionarily constrained regions of the active site using the substrate envelope model. Optimally filling the S4 pocket is critical to avoid resistance and improve potency. Our results provide drug design strategies to avoid resistance that are applicable to other quickly evolving viral drug targets.




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Erratum for Teymournejad et al., "Isolation and Molecular Analysis of a Novel Neorickettsia Species That Causes Potomac Horse Fever"




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Advances in Understanding the Human Urinary Microbiome and Its Potential Role in Urinary Tract Infection

ABSTRACT

Recent advances in the analysis of microbial communities colonizing the human body have identified a resident microbial community in the human urinary tract (UT). Compared to many other microbial niches, the human UT harbors a relatively low biomass. Studies have identified many genera and species that may constitute a core urinary microbiome. However, the contribution of the UT microbiome to urinary tract infection (UTI) and recurrent UTI (rUTI) pathobiology is not yet clearly understood. Evidence suggests that commensal species within the UT and urogenital tract (UGT) microbiomes, such as Lactobacillus crispatus, may act to protect against colonization with uropathogens. However, the mechanisms and fundamental biology of the urinary microbiome-host relationship are not understood. The ability to measure and characterize the urinary microbiome has been enabled through the development of next-generation sequencing and bioinformatic platforms that allow for the unbiased detection of resident microbial DNA. Translating technological advances into clinical insight will require further study of the microbial and genomic ecology of the urinary microbiome in both health and disease. Future diagnostic, prognostic, and therapeutic options for the management of UTI may soon incorporate efforts to measure, restore, and/or preserve the native, healthy ecology of the urinary microbiomes.




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Sometimes You Seek the Spotlight. Sometimes it Finds You.

For decades, government, health systems, universities, foundations, exceptional individuals, and thought leaders across North Carolina have been testing, implementing, modifying, and just plain trying new ways of improving the way we seek, receive, and experience health care.

More recently, North Carolina has been striving to not simply address the cost, efficiency, and value that are so frustratingly elusive in health care, but also recognizing that we simply need to improve the health of our residents. We have looked to interventions both compatible with and beyond health care to do this.

The National Academy of Medicine, formerly the National Institute of Medicine, since 2016 has boldly laid out Vital Directions in Health Care, focusing on 19 priority issues and recommendations for health policy to better achieve health and well-being for all Americans. They have taken their show on the road, beyond the halls of Congress and think tanks and universities to the people on the ground in states across the country to present, discuss, listen, and learn how policy recommendations come to life.

This issue of the journal highlights the National Academy of Medicine bringing its spotlight to North Carolina last November, an acknowledgment that states are often where policy is put into action, and that North Carolina has been a leader in innovating, planning, implementing, and evaluating again and again to get better and better results for our residents. Pull your chair up to the edge of the stage for a good read in the glow of the spotlight.




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Ataxic-hypotonic cerebral palsy in a cerebral palsy registry: Insights into a distinct subtype

Objective

To specifically report on ataxic-hypotonic cerebral palsy (CP) using registry data and to directly compare its features with other CP subtypes.

Methods

Data on prenatal, perinatal, and neonatal characteristics and gross motor function (Gross Motor Function Classification System [GMFCS]) and comorbidities in 35 children with ataxic-hypotonic CP were extracted from the Canadian Cerebral Palsy Registry and compared with 1,804 patients with other subtypes of CP.

Results

Perinatal adversity was detected significantly more frequently in other subtypes of CP (odds ratio [OR] 4.3, 95% confidence interval [CI] 1.5–11.7). The gestational age at birth was higher in ataxic-hypotonic CP (median 39.0 weeks vs 37.0 weeks, p = 0.027). Children with ataxic-hypotonic CP displayed more intrauterine growth restriction (OR 2.6, 95% CI 1.0–6.8) and congenital malformation (OR 2.4, 95% CI 1.2–4.8). MRI was more likely to be either normal (OR 3.8, 95% CI 1.4–10.5) or to show a cerebral malformation (OR 4.2, 95% CI 1.5–11.9) in ataxic-hypotonic CP. There was no significant difference in terms of GMFCS or the presence of comorbidities, except for more frequent communication impairment in ataxic-hypotonic CP (OR 4.2, 95% CI 1.5–11.6).

Conclusions

Our results suggest a predominantly genetic or prenatal etiology for ataxic-hypotonic CP and imply that a diagnosis of ataxic-hypotonic CP does not impart a worse prognosis with respect to comorbidities or functional impairment. This study contributes toward a better understanding of ataxic-hypotonic CP as a distinct nosologic entity within the spectrum of CP with its own pathogenesis, risk factors, clinical profile, and prognosis compared with other CP subtypes.




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Molecular Drivers of Lymphocyte Organization in Vertebrate Mucosal Surfaces: Revisiting the TNF Superfamily Hypothesis [IMMUNOGENETICS]

Key Points

  • Lymphotoxin axis is not essential for formation of O-MALT in ectotherms and birds.

  • Vertebrate O-MALT structures are enriched in neuroactive ligand/receptor genes.

  • Mammalian PPs and LNs are enriched in genes involved in olfactory transduction.




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    Articles of Significant Interest in This Issue [Spotlight]




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    Articles of Significant Interest in This Issue [Spotlight]




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    Both sexes produce sounds in vocal fish species: Testing the hypothesis in the pygmy gourami (Labyrinth fishes) [RESEARCH ARTICLE]

    Noemie Liesch and Friedrich Ladich

    In vocal fish species, males possess larger sound-generating organs and signal acoustically with pronounced sex-specific differences. Sound production is known in two out of three species of croaking gouramis (Trichopsis vittata and T. schalleri). The present study investigates sex-specific differences in sonic organs, vocalizing behaviour and sounds emitted in the third species, the pygmy gourami T. pumila, in order to test the hypothesis that females are able to vocalize despite their less-developed sonic organs, and despite contradictory reports. Croaking gouramis stretch and pluck two enhanced (sonic) pectoral fin tendons during alternate fin beating, resulting in a series of double-pulsed bursts termed croaking sound. We measured the diameter of the first and second sonic tendon and showed that male tendons were twice as large as in same-sized females. We also determined the duration of dyadic contests, visual displays, number of sounds and buttings. Sexes differ in all sound characteristics but in no behavioural variable. Male sounds consisted of twice as many bursts, a higher percentage of double-pulsed bursts and a higher burst period. Additionally, male sounds had a lower dominant frequency and a higher sound level. In summary, female pygmy gouramis possessed sonic organs and vocalized in most dyadic contests. The sexual dimorphism in sonic tendons is clearly reflected in sex-specific differences in sound characteristics, but not in agonistic behaviour, supporting the hypothesis that females are vocal.




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    Use of Human Induced Pluripotent Stem Cells and Kidney Organoids To Develop a Cysteamine/mTOR Inhibition Combination Therapy for Cystinosis

    Background

    Mutations in CTNS—a gene encoding the cystine transporter cystinosin—cause the rare, autosomal, recessive, lysosomal-storage disease cystinosis. Research has also implicated cystinosin in modulating the mTORC1 pathway, which serves as a core regulator of cellular metabolism, proliferation, survival, and autophagy. In its severest form, cystinosis is characterized by cystine accumulation, renal proximal tubule dysfunction, and kidney failure. Because treatment with the cystine-depleting drug cysteamine only slows disease progression, there is an urgent need for better treatments.

    Methods

    To address a lack of good human-based cell culture models for studying cystinosis, we generated the first human induced pluripotent stem cell (iPSC) and kidney organoid models of the disorder. We used a variety of techniques to examine hallmarks of cystinosis—including cystine accumulation, lysosome size, the autophagy pathway, and apoptosis—and performed RNA sequencing on isogenic lines to identify differentially expressed genes in the cystinosis models compared with controls.

    Results

    Compared with controls, these cystinosis models exhibit elevated cystine levels, increased apoptosis, and defective basal autophagy. Cysteamine treatment ameliorates this phenotype, except for abnormalities in apoptosis and basal autophagy. We found that treatment with everolimus, an inhibitor of the mTOR pathway, reduces the number of large lysosomes, decreases apoptosis, and activates autophagy, but it does not rescue the defect in cystine loading. However, dual treatment of cystinotic iPSCs or kidney organoids with cysteamine and everolimus corrects all of the observed phenotypic abnormalities.

    Conclusions

    These observations suggest that combination therapy with a cystine-depleting drug such as cysteamine and an mTOR pathway inhibitor such as everolimus has potential to improve treatment of cystinosis.




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    In Vivo Assessment of Size-Selective Glomerular Sieving in Transplanted Human Induced Pluripotent Stem Cell-Derived Kidney Organoids

    Background

    The utility of kidney organoids in regenerative medicine will rely on the functionality of the glomerular and tubular structures in these tissues. Recent studies have demonstrated the vascularization and subsequent maturation of human pluripotent stem cell–derived kidney organoids after renal subcapsular transplantation. This raises the question of whether the glomeruli also become functional upon transplantation.

    Methods

    We transplanted kidney organoids under the renal capsule of the left kidney in immunodeficient mice followed by the implantation of a titanium imaging window on top of the kidney organoid. To assess glomerular function in the transplanted human pluripotent stem cell–derived kidney tissue 1, 2, and 3 weeks after transplantation, we applied high-resolution intravital multiphoton imaging through the imaging window during intravenous infusion of fluorescently labeled low and high molecular mass dextran molecules or albumin.

    Results

    After vascularization, glomerular structures in the organoid displayed dextran and albumin size selectivity across their glomerular filtration barrier. We also observed evidence of proximal tubular dextran reuptake.

    Conclusions

    Our results demonstrate that human pluripotent stem cell–derived glomeruli can develop an appropriate barrier function and discriminate between molecules of varying size. These characteristics together with tubular presence of low molecular mass dextran provide clear evidence of functional filtration. This approach to visualizing glomerular filtration function will be instrumental for translation of organoid technology for clinical applications as well as for disease modeling.




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    Flavin-Containing Monooxygenase 1 Catalyzes the Production of Taurine from Hypotaurine [Articles]

    Taurine is one of the most abundant amino acids in mammalian tissues. It is obtained from the diet and by de novo synthesis from cysteic acid or hypotaurine. Despite the discovery in 1954 that the oxygenation of hypotaurine produces taurine, the identification of an enzyme catalyzing this reaction has remained elusive. In large part, this is due to the incorrect assignment, in 1962, of the enzyme as an NAD-dependent hypotaurine dehydrogenase. For more than 55 years, the literature has continued to refer to this enzyme as such. Here we show, both in vivo and in vitro, that the enzyme that oxygenates hypotaurine to produce taurine is flavin-containing monooxygenase (FMO) 1. Metabolite analysis of the urine of Fmo1-null mice by 1H NMR spectroscopy revealed a buildup of hypotaurine and a deficit of taurine in comparison with the concentrations of these compounds in the urine of wild-type mice. In vitro assays confirmed that human FMO1 catalyzes the conversion of hypotaurine to taurine, utilizing either NADPH or NADH as cofactor. FMO1 has a wide substrate range and is best known as a xenobiotic- or drug-metabolizing enzyme. The identification that the endogenous molecule hypotaurine is a substrate for the FMO1-catalyzed production of taurine resolves a long-standing mystery. This finding should help establish the role FMO1 plays in a range of biologic processes in which taurine or its deficiency is implicated, including conjugation of bile acids, neurotransmitter, antioxidant and anti-inflammatory functions, and the pathogenesis of obesity and skeletal muscle disorders.

    SIGNIFICANCE STATEMENT

    The identity of the enzyme that catalyzes the biosynthesis of taurine from hypotaurine has remained elusive. Here we show, both in vivo and in vitro, that flavin-containing monooxygenase 1 catalyzes the oxygenation of hypotaurine to produce taurine.