Title: How Dangerous Is Bariatric Surgery?
Category: Procedures and Tests
Created: 3/18/2020 12:00:00 AM
Last Editorial Review: 3/18/2020 12:00:00 AM

Title: Gene Variants Hold New Clues to Autism
Category: Health News
Created: 4/29/2009 12:00:00 AM
Last Editorial Review: 4/29/2009 12:00:00 AM

Title: Early Surgery Best for Children With Hearing Loss
Category: Health News
Created: 4/23/2010 4:10:00 PM
Last Editorial Review: 4/26/2010 12:00:00 AM

Title: Study Makes Strides in Understanding Ovarian Cancer
Category: Health News
Created: 4/26/2010 6:10:00 PM
Last Editorial Review: 4/27/2010 12:00:00 AM

Title: Health Tip: Use Warfarin Safely
Category: Health News
Created: 4/29/2010 8:10:00 AM
Last Editorial Review: 4/29/2010 12:00:00 AM

Title: Health Tip: Caring for a Blister
Category: Health News
Created: 4/30/2012 8:05:00 AM
Last Editorial Review: 4/30/2012 12:00:00 AM

Title: Health Care Disparities Might Affect Black Kids' Cancer Survival
Category: Health News
Created: 5/1/2012 10:05:00 AM
Last Editorial Review: 5/1/2012 12:00:00 AM

Title: Heart Attack Survival Varies Widely Among Hospitals, Study Finds
Category: Health News
Created: 4/30/2012 6:06:00 PM
Last Editorial Review: 5/1/2012 12:00:00 AM

Title: Aspirin as Effective as Warfarin for Heart Failure: Study
Category: Health News
Created: 5/2/2012 6:05:00 PM
Last Editorial Review: 5/3/2012 12:00:00 AM

Title: Magnetic Brain Stimulation May Temporarily Dull Nicotine Craving
Category: Health News
Created: 4/26/2013 12:36:00 PM
Last Editorial Review: 4/29/2013 12:00:00 AM

Title: Centenarians a Happy Lot, Survey Says
Category: Health News
Created: 5/3/2013 12:35:00 PM
Last Editorial Review: 5/3/2013 12:00:00 AM

Title: 'Breast Milk Banks' Gain in Popularity
Category: Health News
Created: 4/29/2014 9:35:00 AM
Last Editorial Review: 4/29/2014 12:00:00 AM

Title: Medical Marijuana May Ease Some MS Symptoms, Study Concludes
Category: Health News
Created: 4/28/2014 4:36:00 PM
Last Editorial Review: 4/29/2014 12:00:00 AM

Title: Caring for Severely Ill Kids May Have Silver Lining
Category: Health News
Created: 4/29/2014 2:35:00 PM
Last Editorial Review: 4/30/2014 12:00:00 AM

Title: When Medical Marijuana Doesn't Work
Category: Health News
Created: 5/1/2014 11:00:00 AM
Last Editorial Review: 5/1/2014 12:00:00 AM

Title: Professional Musicians Face Greater Risk of Hearing Problems
Category: Health News
Created: 5/1/2014 9:35:00 AM
Last Editorial Review: 5/1/2014 12:00:00 AM

Title: Alzheimer's Variation May Often Go Unrecognized: Study
Category: Health News
Created: 5/2/2014 9:35:00 AM
Last Editorial Review: 5/2/2014 12:00:00 AM

Title: Prices of MS Drugs Soaring, Study Finds
Category: Health News
Created: 4/24/2015 12:00:00 AM
Last Editorial Review: 4/27/2015 12:00:00 AM

Title: Doctor Salaries and Job Satisfaction: New Survey
Category: Health News
Created: 4/28/2015 12:00:00 AM
Last Editorial Review: 4/28/2015 12:00:00 AM

Title: Sharing Breast Milk May Pose Risks Women Haven't Considered
Category: Health News
Created: 4/30/2015 12:00:00 AM
Last Editorial Review: 5/1/2015 12:00:00 AM

Title: Temporarily Turning Blue Sometimes Normal for Babies, Doctors Say
Category: Health News
Created: 4/25/2016 12:00:00 AM
Last Editorial Review: 4/25/2016 12:00:00 AM

Title: Health Tip: Managing Varicose Veins
Category: Health News
Created: 4/26/2016 12:00:00 AM
Last Editorial Review: 4/26/2016 12:00:00 AM

Title: U.S. Health Report Card Finds Racial, Ethnic Disparities Persist
Category: Health News
Created: 4/27/2016 12:00:00 AM
Last Editorial Review: 4/27/2016 12:00:00 AM

Title: Hearing Aids May Help Keep Seniors' Minds Sharp
Category: Health News
Created: 4/27/2016 12:00:00 AM
Last Editorial Review: 4/28/2016 12:00:00 AM

Title: Type 2 Diabetes May Damage Hearing, Study Finds
Category: Health News
Created: 4/27/2016 12:00:00 AM
Last Editorial Review: 4/28/2016 12:00:00 AM

Title: Health Tip: Preparing Nutritious Meals
Category: Health News
Created: 5/4/2017 12:00:00 AM
Last Editorial Review: 5/4/2017 12:00:00 AM

Title: Zika Epidemic in U.S. Could Be a Costly Scenario
Category: Health News
Created: 5/3/2017 12:00:00 AM
Last Editorial Review: 5/4/2017 12:00:00 AM

Title: U.S. Illnesses Tied to Ticks, Mosquitoes Are Soaring
Category: Health News
Created: 5/1/2018 12:00:00 AM
Last Editorial Review: 5/2/2018 12:00:00 AM

Title: Malaria Parasite Is Infecting, Killing U.S. Baby Deer
Category: Health News
Created: 5/2/2018 12:00:00 AM
Last Editorial Review: 5/3/2018 12:00:00 AM

Title: U.S. Teen Opioid Deaths Soaring
Category: Health News
Created: 4/30/2019 12:00:00 AM
Last Editorial Review: 5/1/2019 12:00:00 AM

Title: Not Just Opioids: Deaths Tied to Cocaine, Meth Are Soaring, Too
Category: Health News
Created: 5/2/2019 12:00:00 AM
Last Editorial Review: 5/3/2019 12:00:00 AM

Title: Blepharitis
Category: Diseases and Conditions
Created: 5/5/2009 12:00:00 AM
Last Editorial Review: 1/9/2020 12:00:00 AM

Title: Kevzara (sarilumab)
Category: Medications
Created: 4/21/2020 12:00:00 AM
Last Editorial Review: 4/21/2020 12:00:00 AM

Title: Marijuana Withdrawal Is Real, Study Shows
Category: Health News
Created: 4/10/2020 12:00:00 AM
Last Editorial Review: 4/13/2020 12:00:00 AM

Title: Want Fewer UTIs? Go Vegetarian, Study Suggests
Category: Health News
Created: 1/30/2020 12:00:00 AM
Last Editorial Review: 1/31/2020 12:00:00 AM

Title: Birth Control Pill vs. Shot (Depo-Provera): Similarities and Differences
Category: Diseases and Conditions
Created: 6/15/2017 12:00:00 AM
Last Editorial Review: 4/13/2020 12:00:00 AM

Title: Haldol (haloperidol) vs. Abilify (aripiprazole)
Category: Medications
Created: 7/30/2019 12:00:00 AM
Last Editorial Review: 4/10/2020 12:00:00 AM

Title: Ride-Sharing Services Tied to Rise in Car Crashes
Category: Health News
Created: 4/7/2020 12:00:00 AM
Last Editorial Review: 4/8/2020 12:00:00 AM

Title: Malaria
Category: Diseases and Conditions
Created: 12/31/1997 12:00:00 AM
Last Editorial Review: 11/15/2019 12:00:00 AM

ABSTRACT

One of the primary functions of the mucosal barrier, found lining epithelial cells, is to serve as a first-line of defense against microbial pathogens. The major structural components of mucus are heavily glycosylated proteins called mucins. Mucins are key components of the innate immune system as they aid in the clearance of pathogens and can decrease pathogen virulence. It has also been recently reported that individual mucins and derived glycans can attenuate the virulence of the human pathogen Pseudomonas aeruginosa. Here, we show data indicating that mucins not only play a role in host defense but that they can also be subverted by P. aeruginosa to cause disease. We found that the mucin MUL-1 and mucin-derived monosaccharides N-acetyl-galactosamine and N-acetylglucosamine are required for P. aeruginosa killing of Caenorhabditis elegans. We also found that the defective adhesion of P. aeruginosa to human lung alveolar epithelial cells, deficient in the mucin MUC1, can be reversed by the addition of individual monosaccharides. The monosaccharides identified in this study are found in a wide range of organisms where they act as host factors required for bacterial pathogenesis. While mucins in C. elegans lack sialic acid caps, which makes their monosaccharides readily available, they are capped in other species. Pathogens such as P. aeruginosa that lack sialidases may rely on enzymes from other bacteria to utilize mucin-derived monosaccharides.

IMPORTANCE One of the first lines of defense present at mucosal epithelial tissues is mucus, which is a highly viscous material formed by mucin glycoproteins. Mucins serve various functions, but importantly they aid in the clearance of pathogens and debris from epithelial barriers and serve as innate immune factors. In this study, we describe a requirement of host monosaccharides, likely derived from host mucins, for the ability of Pseudomonas aeruginosa to colonize the intestine and ultimately cause death in Caenorhabditis elegans. We also demonstrate that monosaccharides alter the ability of bacteria to bind to both Caenorhabditis elegans intestinal cells and human lung alveolar epithelial cells, suggesting that there are conserved mechanisms underlying host-pathogen interactions in a range of organisms. By gaining a better understanding of pathogen-mucin interactions, we can develop better approaches to protect against pathogen infection.

ABSTRACT

The cell cycle is a critical component of cellular proliferation, differentiation, and response to stress, yet its role in the regulation of intracellular symbioses is not well understood. To explore host-symbiont cell cycle coordination in a marine symbiosis, we employed a model for coral-dinoflagellate associations: the tropical sea anemone Aiptasia (Exaiptasia pallida) and its native microalgal photosymbionts (Breviolum minutum and Breviolum psygmophilum). Using fluorescent labeling and spatial point-pattern image analyses to characterize cell population distributions in both partners, we developed protocols that are tailored to the three-dimensional cellular landscape of a symbiotic sea anemone tentacle. Introducing cultured symbiont cells to symbiont-free adult hosts increased overall host cell proliferation rates. The acceleration occurred predominantly in the symbiont-containing gastrodermis near clusters of symbionts but was also observed in symbiont-free epidermal tissue layers, indicating that the presence of symbionts contributes to elevated proliferation rates in the entire host during colonization. Symbiont cell cycle progression differed between cultured algae and those residing within hosts; the endosymbiotic state resulted in increased S-phase but decreased G₂/M-phase symbiont populations. These phenotypes and the deceleration of cell cycle progression varied with symbiont identity and host nutritional status. These results demonstrate that host and symbiont cells have substantial and species-specific effects on the proliferation rates of their mutualistic partners. This is the first empirical evidence to support species-specific regulation of the symbiont cell cycle within a single cnidarian-dinoflagellate association; similar regulatory mechanisms likely govern interpartner coordination in other coral-algal symbioses and shape their ecophysiological responses to a changing climate.

IMPORTANCE Biomass regulation is critical to the overall health of cnidarian-dinoflagellate symbioses. Despite the central role of the cell cycle in the growth and proliferation of cnidarian host cells and dinoflagellate symbionts, there are few studies that have examined the potential for host-symbiont coregulation. This study provides evidence for the acceleration of host cell proliferation when in local proximity to clusters of symbionts within cnidarian tentacles. The findings suggest that symbionts augment the cell cycle of not only their enveloping host cells but also neighboring cells in the epidermis and gastrodermis. This provides a possible mechanism for rapid colonization of cnidarian tissues. In addition, the cell cycles of symbionts differed depending on nutritional regime, symbiotic state, and species identity. The responses of cell cycle profiles to these different factors implicate a role for species-specific regulation of symbiont cell cycles within host cnidarian tissues.

ABSTRACT

Each year, >180,000 infants become infected via mother-to-child transmission (MTCT) of HIV despite the availability of effective maternal antiretroviral treatments, underlining the need for a maternal HIV vaccine. We characterized 224 maternal HIV envelope (Env)-specific IgG monoclonal antibodies (MAbs) from seven nontransmitting and transmitting HIV-infected U.S. and Malawian mothers and examined their neutralization activities against nontransmitted autologous circulating viruses and infant-transmitted founder (infant-T/F) viruses. Only a small subset of maternal viruses, 3 of 72 (4%), were weakly neutralized by maternal linear V3 epitope-specific IgG MAbs, whereas 6 out of 6 (100%) infant-T/F viruses were neutralization resistant to these V3-specific IgG MAbs. We also show that maternal-plasma broadly neutralizing antibody (bNAb) responses targeting the V3 glycan supersite in a transmitting woman may have selected for an N332 V3 glycan neutralization-resistant infant-T/F virus. These data have important implications for bNAb-eliciting vaccines and passively administered bNAbs in the setting of MTCT.

IMPORTANCE Efforts to eliminate MTCT of HIV with antiretroviral therapy (ART) have met little success, with >180,000 infant infections each year worldwide. It is therefore likely that additional immunologic strategies that can synergize with ART will be required to eliminate MTCT of HIV. To this end, understanding the role of maternal HIV Env-specific IgG antibodies in the setting of MTCT is crucial. In this study, we found that maternal-plasma broadly neutralizing antibody (bNAb) responses can select for T/F viruses that initiate infection in infants. We propose that clinical trials testing the efficacy of single bNAb specificities should not include HIV-infected pregnant women, as a single bNAb might select for neutralization-resistant infant-T/F viruses.

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.

ABSTRACT

The protozoan parasites that cause malaria infect a wide variety of vertebrate hosts, including birds, reptiles, and mammals, and the evolutionary pressures inherent to the host-parasite relationship have profoundly shaped the genomes of both host and parasite. Here, we report that these selective pressures have resulted in unexpected alterations to one of the most basic aspects of eukaryotic biology, the maintenance of genome integrity through DNA repair. Malaria parasites that infect humans continuously generate genetic diversity within their antigen-encoding gene families through frequent ectopic recombination between gene family members, a process that is a crucial feature of the persistence of malaria globally. The continuous generation of antigen diversity ensures that different parasite isolates are antigenically distinct, thus preventing extensive cross-reactive immunity and enabling parasites to maintain stable transmission within human populations. However, the molecular basis of the recombination between gene family members is not well understood. Through computational analyses of the antigen-encoding, multicopy gene families of different Plasmodium species, we report the unexpected observation that malaria parasites that infect rodents do not display the same degree of antigen diversity as observed in Plasmodium falciparum and appear to undergo significantly less ectopic recombination. Using comparative genomics, we also identify key molecular components of the diversification process, thus shedding new light on how malaria parasites balance the maintenance of genome integrity with the requirement for continuous genetic diversification.

IMPORTANCE Malaria remains one of the most prevalent and deadly infectious diseases of the developing world, causing approximately 228 million clinical cases and nearly half a million deaths annually. The disease is caused by protozoan parasites of the genus Plasmodium, and of the five species capable of infecting humans, infections with P. falciparum are the most severe. In addition to the parasites that infect people, there are hundreds of additional species that infect birds, reptiles, and other mammals, each exquisitely evolved to meet the specific challenges inherent to survival within their respective hosts. By comparing the unique strategies that each species has evolved, key insights into host-parasite interactions can be gained, including discoveries regarding the pathogenesis of human disease. Here, we describe the surprising observation that closely related parasites with different hosts have evolved remarkably different methods for repairing their genomes. This observation has important implications for the ability of parasites to maintain chronic infections and for the development of host immunity.

ABSTRACT

The Candida albicans high-affinity phosphate transporter Pho84 is required for normal Target of Rapamycin (TOR) signaling, oxidative stress resistance, and virulence of this fungal pathogen. It also contributes to C. albicans’ tolerance of two antifungal drug classes, polyenes and echinocandins. Echinocandins inhibit biosynthesis of a major cell wall component, beta-1,3-glucan. Cells lacking Pho84 were hypersensitive to other forms of cell wall stress beyond echinocandin exposure, while their cell wall integrity signaling response was weak. Metabolomics experiments showed that levels of phosphoric intermediates, including nucleotides like ATP and nucleotide sugars, were low in pho84 mutant compared to wild-type cells recovering from phosphate starvation. Nonphosphoric precursors like nucleobases and nucleosides were elevated. Outer cell wall phosphomannan biosynthesis requires a nucleotide sugar, GDP-mannose. The nucleotide sugar UDP-glucose is the substrate of enzymes that synthesize two major structural cell wall polysaccharides, beta-1,3- and beta-1,6-glucan. Another nucleotide sugar, UDP-N-acetylglucosamine, is the substrate of chitin synthases which produce a stabilizing component of the intercellular septum and of lateral cell walls. Lack of Pho84 activity, and phosphate starvation, potentiated pharmacological or genetic perturbation of these enzymes. We posit that low substrate concentrations of beta-d-glucan- and chitin synthases, together with pharmacologic inhibition of their activity, diminish enzymatic reaction rates as well as the yield of their cell wall-stabilizing products. Phosphate import is not conserved between fungal and human cells, and humans do not synthesize beta-d-glucans or chitin. Hence, inhibiting these processes simultaneously could yield potent antifungal effects with low toxicity to humans.

IMPORTANCE Candida species cause hundreds of thousands of invasive infections with high mortality each year. Developing novel antifungal agents is challenging due to the many similarities between fungal and human cells. Maintaining phosphate balance is essential for all organisms but is achieved completely differently by fungi and humans. A protein that imports phosphate into fungal cells, Pho84, is not present in humans and is required for normal cell wall stress resistance and cell wall integrity signaling in C. albicans. Nucleotide sugars, which are phosphate-containing building block molecules for construction of the cell wall, are diminished in cells lacking Pho84. Cell wall-constructing enzymes may be slowed by lack of these building blocks, in addition to being inhibited by drugs. Combined targeting of Pho84 and cell wall-constructing enzymes may provide a strategy for antifungal therapy by which two sequential steps of cell wall maintenance are blocked for greater potency.

ABSTRACT

Human milk oligosaccharides (HMOs) may provide health benefits to infants partly by shaping the development of the early-life intestinal microbiota. In a randomized double-blinded controlled multicentric clinical trial, healthy term infants received either infant formula (control) or the same formula with two HMOs (2'-fucosyllactose and lacto-N-neotetraose; test) from enrollment (0 to 14 days) to 6 months. Then, all infants received the same follow-up formula without HMOs until 12 months of age. Breastfed infants (BF) served as a reference group. Stool microbiota at 3 and 12 months, analyzed by 16S rRNA gene sequencing, clustered into seven fecal community types (FCTs) with marked differences in total microbial abundances. Three of the four 12-month FCTs were likely precursors of the adult enterotypes. At 3 months, microbiota composition in the test group (n = 58) appeared closer to that of BF (n = 35) than control (n = 63) by microbiota alpha (within group) and beta (between groups) diversity analyses and distribution of FCTs. While bifidobacteriaceae dominated two FCTs, its abundance was significantly higher in one (FCT BiH for Bifidobacteriaceae at high abundance) than in the other (FCT Bi for Bifidobacteriaceae). HMO supplementation increased the number of infants with FCT BiH (predominant in BF) at the expense of FCT Bi (predominant in control). We explored the association of the FCTs with reported morbidities and medication use up to 12 months. Formula-fed infants with FCT BiH at 3 months were significantly less likely to require antibiotics during the first year than those with FCT Bi. Previously reported lower rates of infection-related medication use with HMOs may therefore be linked to gut microbiota community types. (This study has been registered at ClinicalTrials.gov under registration number NCT01715246.)

IMPORTANCE Human milk is the sole and recommended nutrition for the newborn infant and contains one of the largest constituents of diverse oligosaccharides, dubbed human milk oligosaccharides (HMOs). Preclinical and clinical association studies indicate that HMOs have multiple physiological functions largely mediated through the establishment of the gut microbiome. Until recently, HMOs were not available to investigate their role in randomized controlled intervention trials. To our knowledge, this is the first report on the effects of 2 HMOs on establishing microbiota in newborn infants. We provide a detailed description of the microbiota changes observed upon feeding a formula with 2 HMOs in comparison to breastfed reference infants' microbiota. Then, we associate the microbiota to long-term health as assessed by prescribed antibiotic use.

ABSTRACT

Host persistence of bacteria is facilitated by mutational and recombinatorial processes that counteract loss of genetic variation during transmission and selection from evolving host responses. Genetic variation was investigated during persistent asymptomatic carriage of Neisseria meningitidis. Interrogation of whole-genome sequences for paired isolates from 25 carriers showed that de novo mutations were infrequent, while horizontal gene transfer occurred in 16% of carriers. Examination of multiple isolates per time point enabled separation of sporadic and transient allelic variation from directional variation. A comprehensive comparative analysis of directional allelic variation with hypermutation of simple sequence repeats and hyperrecombination of class 1 type IV pilus genes detected an average of seven events per carrier and 2:1 bias for changes due to localized hypermutation. Directional genetic variation was focused on the outer membrane with 69% of events occurring in genes encoding enzymatic modifiers of surface structures or outer membrane proteins. Multiple carriers exhibited directional and opposed switching of allelic variants of the surface-located Opa proteins that enables continuous expression of these adhesins alongside antigenic variation. A trend for switching from PilC1 to PilC2 expression was detected, indicating selection for specific alterations in the activities of the type IV pilus, whereas phase variation of restriction modification (RM) systems, as well as associated phasevarions, was infrequent. We conclude that asymptomatic meningococcal carriage on mucosal surfaces is facilitated by frequent localized hypermutation and horizontal gene transfer affecting genes encoding surface modifiers such that optimization of adhesive functions occurs alongside escape of immune responses by antigenic variation.

IMPORTANCE Many bacterial pathogens coexist with host organisms, rarely causing disease while adapting to host responses. Neisseria meningitidis, a major cause of meningitis and septicemia, is a frequent persistent colonizer of asymptomatic teenagers/young adults. To assess how genetic variation contributes to host persistence, whole-genome sequencing and hypermutable sequence analyses were performed on multiple isolates obtained from students naturally colonized with meningococci. High frequencies of gene transfer were observed, occurring in 16% of carriers and affecting 51% of all nonhypermutable variable genes. Comparative analyses showed that hypermutable sequences were the major mechanism of variation, causing 2-fold more changes in gene function than other mechanisms. Genetic variation was focused on genes affecting the outer membrane, with directional changes in proteins responsible for bacterial adhesion to host surfaces. This comprehensive examination of genetic plasticity in individual hosts provides a significant new platform for rationale design of approaches to prevent the spread of this pathogen.