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1.
J Clin Orthop Trauma ; 36: 102080, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36465496

ABSTRACT

Background: Many geriatric patients presenting for emergency hip fracture surgery are on direct oral anticoagulants (DOACs) most of which are not easily reversible. A safe policy was required to reduce delays to surgery. Prior to institution of our hospital's protocol in January 2021, most of these patients had surgery after 48 h following the last dose of DOAC due to concerns about increased perioperative blood loss. Methods: This was a prospective closed loop audit of the protocol-surgery within 24 h from last dose of DOAC (if creatinine clearance >50 ml/min) with administration of 1-g of tranexamic acid at anesthesia induction. 131 eligible patients (DOAC, n = 22; no anticoagulation, n = 109) between January-June 2021 who had emergency hip fracture surgery were identified. Primary outcome measures were peri-operative blood loss, transfusion requirements and policy compliance. Secondary outcome measures were 30-day mortality, thrombotic complications and wound bleeding. Results: Compliance with surgical timing and tranexamic acid administration were 55% and 81% respectively after the second audit cycle. The mean estimated blood loss (EBL) in the DOAC group versus the non-anticoagulated control group was 500 ml and 330 ml respectively. The difference between these groups was statistically significant at an alpha level of 5% (P = 0.0115, 95% CI 38.48-299.16). The difference for intra-operative (RR 3.43; 95% CI 1.68-7.01) and post-operative blood transfusion (RR 2.10; 95% CI 1.23-3.58) for the 2 groups was also statistically significant. However, there was no case of massive blood transfusion in both groups. The DOAC group had a lower risk for 30-day mortality (RR 0.71; 95% CI 0.09-5.46). There was no major thrombotic complication in the DOAC group. Conclusion: This audit has shown that this protocol is safe although clinicians should anticipate some degree of increased intra-operative blood loss. We will recommend continuation of this policy with sustained safety monitoring in order to reduce delays to surgery.

2.
Vet Microbiol ; 264: 109298, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34906835

ABSTRACT

The influenza D virus (IDV) uses a trimeric hemagglutinin-esterase fusion protein (HEF) for attachment to 9-O-acetylated sialic acid receptors on the cell surface of host species. So far research has revealed that farm animals such as cattle, domestic pigs, goats, sheep and horses contain the necessary receptors on the epithelial surface of the respiratory tract to accommodate binding of the IDV HEF protein of both worldwide clades D/Oklahoma (D/OK) and D/Oklahoma/660 (D/660). More recently, seroprevalence studies have identified IDV-seropositive wildlife such as wild boar, deer, dromedaries, and small ruminants. However, no research has thus far been conducted in wildlife to reveal the distribution of acetylated sialic acid receptors that accommodate binding of IDV. Using our previously developed tissue microarray (TMA) system, we developed TMAs containing respiratory tissues of various wild and domestic species including wild boar, deer, dromedary, springbok, water buffalo, tiger, hedgehog, and Asian elephant. Protein histochemical staining of these TMAs with HEF proteins showed no receptor binding for wild Suidae, Cervidae and tiger. However, receptors were present in dromedary, springbok, water buffalo, Asian elephant, and hedgehog. In contrast to previously tested farm animals, a difference in host tropism was observed between the D/OK and D/660 clade HEF proteins in Asian elephant, and water buffalo. These results show that IDV can attach to the respiratory tract of wildlife which might facilitate transmission of IDV between wildlife and domestic animals.


Subject(s)
Orthomyxoviridae Infections , Receptors, Cell Surface , Thogotovirus , Animals , Animals, Domestic/virology , Animals, Wild/virology , Cattle , Deer , Horses , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/veterinary , Orthomyxoviridae Infections/virology , Receptors, Cell Surface/immunology , Seroepidemiologic Studies , Sheep , Thogotovirus/classification , Thogotovirus/genetics , Thogotovirus/metabolism
3.
Glycobiology ; 31(10): 1279-1294, 2021 11 18.
Article in English | MEDLINE | ID: mdl-34192335

ABSTRACT

Cancers utilize glycans to evade the immune system via the Sialic acid (Sia)-Siglec (Sialic-acid-binding immunoglobulin-like lectins) pathway. Specifically, atypical structural forms of sialic acid bind to inhibitory Siglec receptors on natural killer (NK) cells resulting in the suppression of immune cell mediated cytotoxicity. The mechanism of action that governs the Sia-Siglec pathway in cancers is not understood. Specifically, how deviations from the typical form of Sia mechanistically contribute. Here, we focused on modulating 9-O and 7, 9-O-acetylation of Neu5Ac, via CRISPR-Cas9 gene editing, a functional group that is absent from Sias on many types of cancer cells. The two genes that are responsible for regulating the level of acetylation on Neu5Ac, are Sialic acid acetylesterase (SIAE) and Sialic acid acetyltransferase (CASD1). These genes modulated Siglec binding in colon, lung and a noncancerous kidney cell line. In the absence of SIAE, Neu5Ac is acetylated, engagement of cancer associated Siglecs is reduced while binding was increased when the ability to acetylate was removed via CASD1 knock out. In the absence of SIAE NK mediated cytotoxicity increased in both colon and lung cancer cells. In addition to modulating Siglec binding, SIAE expression modulates the level of Sias in a cell, and the α2-6-linkage of Sias-which is specifically upregulated and associated with cancers. Uncovering how functional group alterations on Neu5Ac contribute mechanistically to both Siglec receptor binding, the Sia-Siglec immune evasion pathway, and the production of cancer associated glycosidic linkages-offers a promising avenue for targeted cancer immune therapies in the future.


Subject(s)
Sialic Acid Binding Immunoglobulin-like Lectins/metabolism , Sialic Acids/metabolism , Acetylation , Cells, Cultured , Humans , Killer Cells, Natural/immunology
4.
J Evol Biol ; 34(12): 1878-1900, 2021 12.
Article in English | MEDLINE | ID: mdl-34114711

ABSTRACT

Viruses are often cultured in cell lines for research and vaccine development, and those often differ from the natural hosts or tissues. Cell lines can also differ in the presence of virus receptors, such as the sialic acid (Sia) receptors used by influenza A viruses (IAV), which can vary in linkage (α2,3- or α2,6-linkage) and form (N-glycolylneuraminic acid [Neu5Gc] or N-acetylneuraminic acid [Neu5Ac]). The selective pressures resulting from passaging viruses in cell types with host-specific variations in viral receptors are still only partially understood. IAV are commonly cultured in MDCK cells which are both derived from canine kidney tubule epithelium and inherently heterogeneous. MDCK cells naturally present Neu5Ac and α2,3-linked Sia forms. Here, we examine natural MDCK variant lineages, as well as engineered variants that synthesize Neu5Gc and/or α2,6-linkages. We determined how viral genetic variation occurred within human H3N2, H1N1 pandemic and canine H3N2 IAV populations when serially passaged in MDCK cell lines that vary in cell type (MDCK-Type I or MDCK-Type II clones) and in Sia display. Deep sequencing of viral genomes showed small numbers of consensus-level mutations, mostly within the hemagglutinin (HA) gene. Both human IAV showed variants in the HA stem and the HA receptor-binding site of populations passaged in cells displaying Neu5Gc. Canine H3N2 showed variants near the receptor-binding site when passaged in cells displaying Neu5Gc or α2,6-linkages. Viruses replicated to low titres in MDCK-Type II cells, suggesting that not all cell types in heterogeneous MDCK cell populations are equally permissive to infection.


Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza A virus , Animals , Cell Line , Dogs , Humans , Influenza A Virus, H3N2 Subtype/genetics , Influenza A virus/genetics , Madin Darby Canine Kidney Cells , Receptors, Cell Surface , Vaccine Development
5.
J Virol ; 94(24)2020 11 23.
Article in English | MEDLINE | ID: mdl-32967961

ABSTRACT

Influenza virus isolation from clinical samples is critical for the identification and characterization of circulating and emerging viruses. Yet efficient isolation can be difficult. In these studies, we isolated primary swine nasal and tracheal respiratory epithelial cells and immortalized swine nasal epithelial cells (siNEC) and tracheal epithelial cells (siTEC) that retained the abilities to form tight junctions and cilia and to differentiate at the air-liquid interface like primary cells. Critically, both human and swine influenza viruses replicated in the immortalized cells, which generally yielded higher-titer viral isolates from human and swine nasal swabs, supported the replication of isolates that failed to grow in Madin-Darby canine kidney (MDCK) cells, and resulted in fewer dominating mutations during viral passaging than MDCK cells.IMPORTANCE Robust in vitro culture systems for influenza virus are critically needed. MDCK cells, the most widely used cell line for influenza isolation and propagation, do not adequately model the respiratory tract. Therefore, many clinical isolates, both animal and human, are unable to be isolated and characterized, limiting our understanding of currently circulating influenza viruses. We have developed immortalized swine respiratory epithelial cells that retain the ability to differentiate and can support influenza replication and isolation. These cell lines can be used as additional tools to enhance influenza research and vaccine development.


Subject(s)
Epithelial Cells/virology , Influenza A virus/growth & development , Influenza A virus/isolation & purification , Respiratory System/virology , Virus Cultivation/methods , Animals , Cell Line , Dogs , Humans , Influenza A virus/genetics , Kinetics , Madin Darby Canine Kidney Cells , Swine , Trachea , Virus Replication
6.
Int J Orthop Trauma Nurs ; 39: 100780, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32499201

ABSTRACT

The updated RCN Competence Framework for orthopaedic and trauma practitioners was published in 2019 following completion of a 2 year project undertaken by a working group of representatives from England, Northern Ireland, Scotland and Wales. Expert musculoskeletal practitioners, including an allied health professional and working across the lifespan in varying domains of orthopaedic and trauma practice, collaborated to produce a working document applicable to trauma and orthopaedic (T&O) practitioners from all NHS (UK) pay bands. The 2019 document builds on the original and subsequent versions (2005 and 2012), importing new evidence and reformatting it so that it is contemporary and easily cross referenced with the NMC Code (2018). The restructure includes an example of a learning contract demonstrating how the framework can be applied in practice, whether for self-learning, or in conjunction with the revalidation process. This paper reflects on and describes the process undertaken by the working group in the development and restructuring of the 2019 framework, including its evaluation to date and planned in the future.


Subject(s)
Nurses , Orthopedics , Clinical Competence , Humans , United Kingdom
7.
PLoS Pathog ; 16(2): e1008336, 2020 02.
Article in English | MEDLINE | ID: mdl-32084237

ABSTRACT

Typhoid toxin is an A2B5 toxin secreted from Salmonella Typhi-infected cells during human infection and is suggested to contribute to typhoid disease progression and the establishment of chronic infection. To deliver the enzymatic 'A' subunits of the toxin to the site of action in host cells, the receptor-binding 'B' subunit PltB binds to the trisaccharide glycan receptor moieties terminated in N-acetylneuraminic acid (Neu5Ac) that is α2-3 or α2-6 linked to the underlying disaccharide, galactose (Gal) and N-acetylglucosamine (GlcNAc). Neu5Ac is present in both unmodified and modified forms, with 9-O-acetylated Neu5Ac being the most common modification in humans. Here we show that host cells associated with typhoid toxin-mediated clinical signs express both unmodified and 9-O-acetylated glycan receptor moieties. We found that PltB binds to 9-O-acetylated α2-3 glycan receptor moieties with a markedly increased affinity, while the binding affinity to 9-O-acetylated α2-6 glycans is only slightly higher, as compared to the affinities of PltB to the unmodified counterparts, respectively. We also present X-ray co-crystal structures of PltB bound to related glycan moieties, which supports the different effects of 9-O-acetylated α2-3 and α2-6 glycan receptor moieties on the toxin binding. Lastly, we demonstrate that the cells exclusively expressing unmodified glycan receptor moieties are less susceptible to typhoid toxin than the cells expressing 9-O-acetylated counterparts, although typhoid toxin intoxicates both cells. These results reveal a fine-tuning mechanism of a bacterial toxin that exploits specific chemical modifications of its glycan receptor moieties for virulence and provide useful insights into the development of therapeutics against typhoid fever.


Subject(s)
Bacterial Proteins/metabolism , Bacterial Proteins/ultrastructure , Bacterial Toxins/metabolism , Salmonella typhi/metabolism , Acetylation , Animals , Cell Line , Humans , Mice , Mice, Knockout , N-Acetylneuraminic Acid/metabolism , Polysaccharides/metabolism , Protein Binding , Salmonella enterica/metabolism , Salmonella enterica/pathogenicity , Salmonella typhi/pathogenicity , Trisaccharides/metabolism , Typhoid Fever/microbiology , Virulence
8.
J Virol ; 94(9)2020 04 16.
Article in English | MEDLINE | ID: mdl-32051275

ABSTRACT

Sialic acids (Sia) are the primary receptors for influenza viruses and are widely displayed on cell surfaces and in secreted mucus. Sia may be present in variant forms that include O-acetyl modifications at C-4, C-7, C-8, and C-9 positions and N-acetyl or N-glycolyl at C-5. They can also vary in their linkages, including α2-3 or α2-6 linkages. Here, we analyze the distribution of modified Sia in cells and tissues of wild-type mice or in mice lacking CMP-N-acetylneuraminic acid hydroxylase (CMAH) enzyme, which synthesizes N-glycolyl (Neu5Gc) modifications. We also examined the variation of Sia forms on erythrocytes and in saliva from different animals. To determine the effect of Sia modifications on influenza A virus (IAV) infection, we tested for effects on hemagglutinin (HA) binding and neuraminidase (NA) cleavage. We confirmed that 9-O-acetyl, 7,9-O-acetyl, 4-O-acetyl, and Neu5Gc modifications are widely but variably expressed in mouse tissues, with the highest levels detected in the respiratory and gastrointestinal (GI) tracts. Secreted mucins in saliva and surface proteins of erythrocytes showed a high degree of variability in display of modified Sia between different species. IAV HAs from different virus strains showed consistently reduced binding to both Neu5Gc- and O-acetyl-modified Sia; however, while IAV NAs were inhibited by Neu5Gc and O-acetyl modifications, there was significant variability between NA types. The modifications of Sia in mucus may therefore have potent effects on the functions of IAV and may affect both pathogens and the normal flora of different mucosal sites.IMPORTANCE Sialic acids (Sia) are involved in numerous different cellular functions and are receptors for many pathogens. Sia come in chemically modified forms, but we lack a clear understanding of how they alter interactions with microbes. Here, we examine the expression of modified Sia in mouse tissues, on secreted mucus in saliva, and on erythrocytes, including those from IAV host species and animals used in IAV research. These Sia forms varied considerably among different animals, and their inhibitory effects on IAV NA and HA activities and on bacterial sialidases (neuraminidases) suggest a host-variable protective role in secreted mucus.


Subject(s)
Influenza A virus/metabolism , Mucus/metabolism , N-Acetylneuraminic Acid/metabolism , A549 Cells , Animals , Dogs , Erythrocytes/metabolism , Female , Hemagglutinin Glycoproteins, Influenza Virus/metabolism , Hemagglutinins/metabolism , Humans , Influenza A virus/physiology , Influenza, Human/metabolism , Madin Darby Canine Kidney Cells , Male , Mice , Mixed Function Oxygenases/metabolism , Neuraminidase/metabolism , Orthomyxoviridae/metabolism , Receptors, Virus/metabolism , Saliva/chemistry
9.
mBio ; 10(6)2019 12 03.
Article in English | MEDLINE | ID: mdl-31796537

ABSTRACT

Sialic acids (Sia) are widely displayed on the surfaces of cells and tissues. Sia come in a variety of chemically modified forms, including those with acetyl modifications at the C-7, C-8, and C-9 positions. Here, we analyzed the distribution and amounts of these acetyl modifications in different human and canine cells. Since Sia or their variant forms are receptors for influenza A, B, C, and D viruses, we examined the effects of these modifications on virus infections. We confirmed that 9-O-acetyl and 7,9-O-acetyl modified Sia are widely but variably expressed across cell lines from both humans and canines. Although they were expressed on the cell surfaces of canine MDCK cell lines, they were located primarily within the Golgi compartment of human HEK-293 and A549 cells. The O-acetyl modified Sia were expressed at low levels of 1 to 2% of total Sia in these cell lines. We knocked out and overexpressed the sialate O-acetyltransferase gene (CasD1) and knocked out the sialate O-acetylesterase gene (SIAE) using CRISPR/Cas9 editing. Knocking out CasD1 removed 7,9-O- and 9-O-acetyl Sia expression, confirming previous reports. However, overexpression of CasD1 and knockout of SIAE gave only modest increases in 9-O-acetyl levels in cells and no change in 7,9-O-acetyl levels, indicating that there are complex regulations of these modifications. These modifications were essential for influenza C and D infection but had no obvious effect on influenza A and B infection.IMPORTANCE Sialic acids are key glycans that are involved in many different normal cellular functions, as well as being receptors for many pathogens. However, Sia come in diverse chemically modified forms. Here, we examined and manipulated the expression of 7,9-O- and 9-O-acetyl modified Sia on cells commonly used in influenza virus and other research by engineering the enzymes that produce or remove the acetyl groups.


Subject(s)
Acetylesterase/metabolism , N-Acetylneuraminic Acid/metabolism , Orthomyxoviridae/metabolism , A549 Cells , Animals , Cell Line , Cell Line, Tumor , Dogs , Golgi Apparatus/metabolism , HEK293 Cells , Humans , Madin Darby Canine Kidney Cells
10.
J Virol ; 93(23)2019 12 01.
Article in English | MEDLINE | ID: mdl-31511393

ABSTRACT

Influenza A viruses have regularly jumped to new host species to cause epidemics or pandemics, an evolutionary process that involves variation in the viral traits necessary to overcome host barriers and facilitate transmission. Mice are not a natural host for influenza virus but are frequently used as models in studies of pathogenesis, often after multiple passages to achieve higher viral titers that result in clinical disease such as weight loss or death. Here, we examine the processes of influenza A virus infection and evolution in mice by comparing single nucleotide variations of a human H1N1 pandemic virus, a seasonal H3N2 virus, and an H3N2 canine influenza virus during experimental passage. We also compared replication and sequence variation in wild-type mice expressing N-glycolylneuraminic acid (Neu5Gc) with those seen in mice expressing only N-acetylneuraminic acid (Neu5Ac). Viruses derived from plasmids were propagated in MDCK cells and then passaged in mice up to four times. Full-genome deep sequencing of the plasmids, cultured viruses, and viruses from mice at various passages revealed only small numbers of mutational changes. The H3N2 canine influenza virus showed increases in frequency of sporadic mutations in the PB2, PA, and NA segments. The H1N1 pandemic virus grew well in mice, and while it exhibited the maintenance of some minority mutations, there was no clear evidence for adaptive evolution. The H3N2 seasonal virus did not establish in the mice. Finally, there were no clear sequence differences associated with the presence or absence of Neu5Gc.IMPORTANCE Mice are commonly used as a model to study the growth and virulence of influenza A viruses in mammals but are not a natural host and have distinct sialic acid receptor profiles compared to humans. Using experimental infections with different subtypes of influenza A virus derived from different hosts, we found that evolution of influenza A virus in mice did not necessarily proceed through the linear accumulation of host-adaptive mutations, that there was variation in the patterns of mutations detected in each repetition, and that the mutation dynamics depended on the virus examined. In addition, variation in the viral receptor, sialic acid, did not affect influenza virus evolution in this model. Overall, our results show that while mice provide a useful animal model for influenza virus pathology, host passage evolution will vary depending on the specific virus tested.


Subject(s)
High-Throughput Nucleotide Sequencing/methods , Influenza A virus/genetics , Influenza, Human/metabolism , Influenza, Human/virology , N-Acetylneuraminic Acid/metabolism , Animals , Biological Evolution , Disease Models, Animal , Dogs , Host Specificity , Humans , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H3N2 Subtype/genetics , Lung/pathology , Madin Darby Canine Kidney Cells , Mice , Mice, Inbred C57BL , Mice, Knockout , Mixed Function Oxygenases/genetics , Orthomyxoviridae Infections/metabolism , Orthomyxoviridae Infections/virology , Sequence Analysis , Serial Passage , Virulence/genetics
11.
PLoS Pathog ; 15(6): e1007896, 2019 06.
Article in English | MEDLINE | ID: mdl-31233555

ABSTRACT

Streptococcus gordonii and Streptococcus sanguinis are primary colonizers of the tooth surface. Although generally non-pathogenic in the oral environment, they are a frequent cause of infective endocarditis. Both streptococcal species express a serine-rich repeat surface adhesin that mediates attachment to sialylated glycans on mucin-like glycoproteins, but the specific sialoglycan structures recognized can vary from strain to strain. Previous studies have shown that sialoglycan binding is clearly important for aortic valve infections caused by some S. gordonii, but this process did not contribute to the virulence of a strain of S. sanguinis. However, these streptococci can bind to different subsets of sialoglycan structures. Here we generated isogenic strains of S. gordonii that differ only in the type and range of sialoglycan structures to which they adhere and examined whether this rendered them more or less virulent in a rat model of endocarditis. The findings indicate that the recognition of specific sialoglycans can either enhance or diminish pathogenicity. Binding to sialyllactosamine reduces the initial colonization of mechanically-damaged aortic valves, whereas binding to the closely-related trisaccharide sialyl T-antigen promotes higher bacterial densities in valve tissue 72 hours later. A surprising finding was that the initial attachment of streptococci to aortic valves was inversely proportional to the affinity of each strain for platelets, suggesting that binding to platelets circulating in the blood may divert bacteria away from the endocardial surface. Importantly, we found that human and rat platelet GPIbα (the major receptor for S. gordonii and S. sanguinis on platelets) display similar O-glycan structures, comprised mainly of a di-sialylated core 2 hexasaccharide, although the rat GPIbα has a more heterogenous composition of modified sialic acids. The combined results suggest that streptococcal interaction with a minor O-glycan on GPIbα may be more important than the over-all affinity for GPIbα for pathogenic effects.


Subject(s)
Endocarditis, Bacterial/immunology , Glycoproteins/immunology , Sialic Acids/immunology , Streptococcal Infections/immunology , Streptococcus gordonii/immunology , Streptococcus sanguis/immunology , Animals , Disease Models, Animal , Endocarditis, Bacterial/pathology , Female , Humans , Male , Rats , Rats, Sprague-Dawley , Severity of Illness Index , Streptococcal Infections/pathology , Streptococcus gordonii/pathogenicity , Streptococcus sanguis/pathogenicity
12.
J Virol ; 93(6)2019 03 15.
Article in English | MEDLINE | ID: mdl-30626673

ABSTRACT

Parvovirus-derived endogenous viral elements (EVEs) have been found in the genomes of many different animal species, resulting from integration events that may have occurred from more than 50 million years ago to much more recently. Here, we further investigate the properties of autonomous parvovirus EVEs and describe their relationships to contemporary viruses. While we did not find any intact capsid protein open reading frames in the integrated viral sequences, we examined three EVEs that were repaired to form full-length sequences with relatively few changes. These sequences were found in the genomes of Rattus norvegicus (brown rat), Mus spretus (Algerian mouse), and Apodemus sylvaticus (wood mouse). The R. norvegicus sequence was not present in the genomes of the closely related species R. rattus, R. tanezumi, R. exulans, and R. everetti, indicating that it was less than 2 million years old, and the M. spretus and A. sylvaticus sequences were not found in the published genomes of other mouse species, also indicating relatively recent insertions. The M. spretus VP2 sequence assembled into capsids, which had high thermal stability, bound the sialic acid N-acetylneuraminic acid, and entered murine L cells. The 3.89-Å structure of the M. spretus virus-like particles (VLPs), determined using cryo-electron microscopy, showed similarities to rodent and porcine parvovirus capsids. The repaired VP2 sequences from R. norvegicus and A. sylvaticus did not assemble as first prepared, but chimeras combining capsid surface loops from R. norvegicus with canine parvovirus assembled, allowing some of that capsid's structures and functions to be examined.IMPORTANCE Parvovirus endogenous viral elements (EVEs) that have been incorporated into the genomes of different animals represent remnants of the DNA sequences of ancient viruses that infected the ancestors of those animals millions of years ago, but we know little about their properties or how they differ from currently circulating parvoviruses. By expressing the capsid proteins of different parvovirus EVEs that were found integrated into the genomes of three different rodents, we can examine their structures and functions. A VP2 (major capsid protein) EVE sequence from a mouse genome assembled into capsids that had a similar structure and biophysical properties to extant parvoviruses and also bound sialic acids and entered rodent cells. Chimeras formed from combinations of canine parvovirus and portions of the parvovirus sequences from the brown rat genome allowed us to examine the structures and functions of the surface loops of that EVE capsid.


Subject(s)
Capsid Proteins/genetics , Genome/genetics , Parvoviridae Infections/genetics , Parvovirus/genetics , Rodentia/genetics , Rodentia/virology , Animals , Capsid , Cats , Cell Line , Dogs , HEK293 Cells , Humans , Mice , Parvoviridae Infections/virology , Rats , Sf9 Cells , Swine
13.
mSphere ; 2(5)2017.
Article in English | MEDLINE | ID: mdl-28904995

ABSTRACT

Sialic acids (Sias) are important glycans displayed on the cells and tissues of many different animals and are frequent targets for binding and modification by pathogens, including influenza viruses. Influenza virus hemagglutinins bind Sias during the infection of their normal hosts, while the encoded neuraminidases and/or esterases remove or modify the Sia to allow virion release or to prevent rebinding. Sias naturally occur in a variety of modified forms, and modified Sias can alter influenza virus host tropisms through their altered interactions with the viral glycoproteins. However, the distribution of modified Sia forms and their effects on pathogen-host interactions are still poorly understood. Here we used probes developed from viral Sia-binding proteins to detect O-acetylated (4-O-acetyl, 9-O-acetyl, and 7,9-O-acetyl) Sias displayed on the tissues of some natural or experimental hosts for influenza viruses. These modified Sias showed highly variable displays between the hosts and tissues examined. The 9-O-acetyl (and 7,9-) modified Sia forms were found on cells and tissues of many hosts, including mice, humans, ferrets, guinea pigs, pigs, horses, dogs, as well as in those of ducks and embryonated chicken egg tissues and membranes, although in variable amounts. The 4-O-acetyl Sias were found in the respiratory tissues of fewer animals, being primarily displayed in the horse and guinea pig, but were not detected in humans or pigs. The results suggest that these Sia variants may influence virus tropisms by altering and selecting their cell interactions. IMPORTANCE Sialic acids (Sias) are key glycans that control or modulate many normal cell and tissue functions while also interacting with a variety of pathogens, including many different viruses. Sias are naturally displayed in a variety of different forms, with modifications at several positions that can alter their functional interactions with pathogens. In addition, Sias are often modified or removed by enzymes such as host or pathogen esterases or sialidases (neuraminidases), and Sia modifications can alter those enzymatic activities to impact pathogen infections. Sia chemical diversity in different hosts and tissues likely alters the pathogen-host interactions and influences the outcome of infection. Here we explored the display of 4-O-acetyl, 9-O-acetyl, and 7,9-O-acetyl modified Sia forms in some target tissues for influenza virus infection in mice, humans, birds, guinea pigs, ferrets, swine, horses, and dogs, which encompass many natural and laboratory hosts of those viruses.

14.
Trends Microbiol ; 24(12): 991-1001, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27491885

ABSTRACT

Sialic acids (Sias) are abundantly displayed on the surfaces of vertebrate cells, and particularly on all mucosal surfaces. Sias interact with microbes of many types, and are the targets of specific recognition by many different viruses. They may mediate virus binding and infection of cells, or alternatively can act as decoy receptors that bind virions and block virus infection. These nine-carbon backbone monosaccharides naturally occur in many different modified forms, and are attached to underlying glycans through varied linkages, creating significant diversity in the pathogen receptor forms. Here we review the current knowledge regarding the distribution of modified Sias in different vertebrate hosts, tissues, and cells, their effects on viral pathogens where those have been examined, and outline unresolved questions.


Subject(s)
Sialic Acids/chemistry , Virion/physiology , Virus Attachment , Animals , Avulavirus/physiology , Host-Pathogen Interactions , Humans , N-Acetylneuraminic Acid/chemistry , N-Acetylneuraminic Acid/metabolism , Polysaccharides/chemistry , Receptors, Virus/chemistry , Sialic Acids/metabolism , Viral Tropism
15.
PLoS One ; 11(5): e0156068, 2016.
Article in English | MEDLINE | ID: mdl-27191848

ABSTRACT

The global burden of osteoporotic fractures is associated with significant morbidity, mortality, and healthcare costs. We examined the ClinicalTrials.gov database to determine whether recently registered clinical trials addressed prevention and treatment in those at high risk for fracture. A dataset of 96,346 trials registered in ClinicalTrials.gov was downloaded on September 27, 2010. At the time of the dataset download, 40,970 interventional trials had been registered since October 1, 2007. The osteoporosis subset comprised 239 interventional trials (0.6%). Those trials evaluating orthopedic procedures were excluded. The primary purpose was treatment in 67.0%, prevention in 20.1%, supportive care in 5.8%, diagnostic in 2.2%, basic science in 3.1%, health services research in 0.9%, and screening in 0.9%. The majority of studies (61.1%) included drug-related interventions. Most trials (56.9%) enrolled only women, 38.9% of trials were open to both men and women, and 4.2% enrolled only men. Roughly one fifth (19.7%) of trials excluded research participants older than 65 years, and 33.5% of trials excluded those older than 75 years. The funding sources were industry in 51.0%, the National Institutes of Health in 6.3%, and other in 42.7%. We found that most osteoporosis-related trials registered from October 2007 through September 2010 examined the efficacy and safety of drug treatment, and fewer trials examined prevention and non-drug interventions. Trials of interventions that are not required to be registered in ClinicalTrials.gov may be underrepresented. Few trials are specifically studying osteoporosis in men and older adults. Recently registered osteoporosis trials may not sufficiently address fracture prevention.


Subject(s)
Clinical Trials as Topic/standards , Osteoporosis/drug therapy , Aged , Bias , Bone Density Conservation Agents/adverse effects , Bone Density Conservation Agents/therapeutic use , Clinical Trials as Topic/economics , Clinical Trials as Topic/statistics & numerical data , Female , Humans , Male , Orthopedic Procedures/adverse effects , Osteoporosis/prevention & control , Osteoporosis/therapy , Patient Selection
16.
Calcif Tissue Int ; 94(6): 659-64, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24699797

ABSTRACT

Fewer than 24% of Veterans received appropriate evaluation and/or treatment for osteoporosis within 6 months of an index fracture. An electronic consult (E-consult) service was implemented at three Veterans Affairs Medical Centers to facilitate the identification of and recommend management for patients with recent fracture. The E-consult service used clinical encounter data based on ICD9 diagnosis codes to prospectively identify patients with potential osteoporotic fractures. Eligible patients' medical records were reviewed by a metabolic bone specialist, and an E-consult note was sent to the patient's primary provider with specific recommendations for further management. Recommendations were initiated at the provider's discretion. Between 2011 and 2013, the E-consult service identified 444 eligible patients with a low-trauma fracture who were not already on treatment. One hundred twenty-nine (29.1%) consults recommended immediate bisphosphonate treatment, and 258 (58.1%) recommended bone density assessments. Primary providers responded by prescribing bisphosphonates in 74 patients (57.4%) and by ordering bone density testing in 183 (70.9%) patients. At the facility level, prior to implementation of the E-consult service, the rate of osteoporosis treatment following a fracture was 4.8% for bisphosphonates and 21.3% for calcium/vitamin D. After implementation, the treatment rate increased to 7.3% for bisphosphonates (p = 0.02) and 35.2% for calcium/vitamin D (p < 0.01). While feasible and relatively low-cost, an E-consult service modestly improved the rate of osteoporosis treatment among patients with a recent fracture. These results suggest that a program with direct patient interaction is probably required to substantially improve treatment rates.


Subject(s)
Bone Density Conservation Agents/therapeutic use , Fractures, Bone/prevention & control , Osteoporosis/drug therapy , Practice Patterns, Physicians' , Remote Consultation/methods , Absorptiometry, Photon , Aged , Calcium/therapeutic use , Dietary Supplements , Electronic Health Records , Feasibility Studies , Female , Fractures, Bone/etiology , Humans , Male , Mass Screening/methods , Middle Aged , Osteoporosis/complications , Veterans , Vitamin D/therapeutic use
17.
Am J Geriatr Pharmacother ; 8(1): 4-33, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20226390

ABSTRACT

BACKGROUND: Vitamin D insufficiency is prevalent among older adults and may be associated with higher risk for cardiovascular (CV) disease, mortality, depression, and cognitive deficits. OBJECTIVE: The aim of this article was to review published observational and experimental studies that explored the association between vitamin D insufficiency and CV disease, mortality, mood, and cognition with an emphasis on older adults. METHODS: PubMed and Web of Science databases were searched for English-language articles from January 1966 through June 2009 relating to vitamin D, using the following MeSH terms: aged, vitamin D deficiency, physiopathology, drug therapy, cardiovascular diseases, blood pressure, mortality, delirium, dementia, cognitive disorders, depression, depressive disorder, seasonal affective disorder, mental disorders, and vitamin D/therapeutic use. Publications had to include patients > or =65 years of age who had > or =1 recorded measurement of 25-hydroxyvitamin D (25[OH]D) or were receiving vitamin D supplementation. All case-control, cohort, and randomized studies were reviewed. RESULTS: Forty-two case-control, cohort, and randomized trials were identified and included in the review. Based on these publications, the prevalence of vitamin D insufficiency (25[OH]D concentration <30 ng/mL) in communitydwelling older adults (> or =65 years of age) ranged from 40% to 100%. Epidemiologic data and several small randomized trials found a potential association between vitamin D deficiency (25[OH]D concentration <10 ng/mL) and CV disease, including hypertension and ischemic heart disease. Although subgroup analyses of data from the Women's Health Initiative Randomized Trial (the largest randomized, placebo-controlled trial of vitamin D plus calcium therapy) did not find reductions in blood pressure, myocardial infarction, or CV disease-related deaths, intervention contamination limited the findings. Observational studies and a meta-analysis of randomized controlled trials found a mortality benefit associated with higher serum 25(OH)D concentrations or vitamin D(2) or D(3) supplementation (mean dose, 528 IU/d). Observational and small randomized trials found a potential benefit of sunlight or vitamin D on symptoms of depression and cognition, but the findings were limited by methodologic problems. CONCLUSIONS: Vitamin D insufficiency appears to be highly prevalent among older adults. Evidence from epidemiologic studies and small clinical trials suggests an association between 25(OH)D concentrations and systolic blood pressure, risk for CV disease-related deaths, symptoms of depression, cognitive deficits, and mortality. The Women's Health Initiative Randomized Trial did not find a benefit of vitamin D supplementation on blood pressure, myocardial infarction, or mortality in postmenopausal women.


Subject(s)
Affect/drug effects , Cardiovascular Diseases/drug therapy , Cognition Disorders/drug therapy , Cognition/physiology , Vitamin D Deficiency/drug therapy , Vitamin D Deficiency/mortality , Vitamin D/administration & dosage , Affect/physiology , Aging/drug effects , Aging/psychology , Animals , Cardiovascular Diseases/etiology , Cardiovascular Diseases/mortality , Cognition Disorders/etiology , Cognition Disorders/mortality , Female , Humans , Male , Randomized Controlled Trials as Topic/methods , Vitamin D Deficiency/complications
18.
Diabetes Metab Syndr Obes ; 3: 363-72, 2010 Oct 27.
Article in English | MEDLINE | ID: mdl-21437106

ABSTRACT

Adequate glycemic control in type 2 diabetes remains a difficult but achievable goal. The development of new classes of glucose-lowering medications, including in particular the incretin-based therapies, provides an opportunity to utilize combinations of medications which target multiple physiologic abnormalities in type 2 diabetes. Complementary combination therapy with sitagliptin-metformin lowers glucose via enhancement of insulin secretion, suppression of glucagon secretion, and insulin sensitization. Use of this combination in diabetes management will provide a greater degree of glycosylated hemoglobin-lowering than that seen with the use of either drug as monotherapy, is unlikely to cause significant hypoglycemia, and is generally associated with weight loss. The effectiveness, tolerability, and potential cost savings associated with the use of sitagliptin-metformin combination therapy make this an attractive option in diabetes management. The possible beneficial effects of this therapy on beta cell function, as well as its cardiovascular impact, remain inadequately explored but are of significant interest.

19.
J Womens Health (Larchmt) ; 12(9): 911-9, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14670171

ABSTRACT

PURPOSE: Chronic diseases have been associated with decrements in health status, as measured by the Medical Outcomes Study's Short Form-36 (SF-36). Menstrual symptoms (including irregular menses, menorrhagia, dysmenorrhea and premenstrual symptoms) are common, but little is known about their impact on health status. We sought to determine the prevalence of menstrual symptoms and the degree to which these symptoms affect health status. METHODS: This was a mailed survey including questions about sociodemographic characteristics, military experiences, current physical symptoms and medical conditions, mental health, health status (SF-36), and life experiences. The participants were a nationally representative, randomly selected sample of women veterans who had made at least one ambulatory visit to a Veterans Affairs facility between July 1, 1994 and June 30, 1995. The main outcome measures were eight domains of the SF-36 health status questionnaire. RESULTS: Among 3632 respondents (58.4% response rate), 1744 were menstruating women and formed the analytical sample for this study. Among these women (mean age 35.8), 67% reported one or more menstrual symptoms. Women with menstrual symptoms had significantly lower scores for all domains of the SF-36 (p < 0.01), except energy and vitality (p < 0.05), both before and after adjusting for sociodemographic, psychosocial, and comorbidity variables. CONCLUSIONS: Women veterans who report one or more menstrual symptoms have significantly lower health status compared with those reporting none. Clinicians providing care for women should be attuned to the potential impact of menstrual symptoms on the lives of their patients.


Subject(s)
Health Status , Menstruation Disturbances/epidemiology , Sickness Impact Profile , Women's Health , Adult , Depression/complications , Depression/psychology , Female , Humans , Linear Models , Menstruation Disturbances/complications , Menstruation Disturbances/diagnosis , Middle Aged , Prevalence , Socioeconomic Factors , Surveys and Questionnaires , United States/epidemiology , United States Department of Veterans Affairs , Veterans/psychology , Veterans/statistics & numerical data
20.
Cleve Clin J Med ; 69(5): 425-32, 2002 May.
Article in English | MEDLINE | ID: mdl-12022387

ABSTRACT

Many women have breast symptoms-swelling and tenderness, nodularity, pain, palpable lumps, nipple discharge, or breast infections and inflammation. Fortunately, relatively few have breast cancer. Physicians must distinguish benign breast conditions from malignant ones, and know when to refer the patient to a specialist. We have included some of the newer diagnostic techniques and the approach to patients with nonpalpable lesions detected on a screening mammogram.


Subject(s)
Breast Diseases/therapy , Breast Diseases/classification , Breast Diseases/complications , Breast Diseases/diagnosis , Breast Neoplasms/diagnosis , Female , Galactorrhea/etiology , Humans , Mammography , Referral and Consultation
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