Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 19 de 19
Filter
Add more filters










Publication year range
1.
Addiction ; 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38631671

ABSTRACT

BACKGROUND AND AIMS: Drug-related deaths in Scotland more than doubled between 2011 and 2020. To inform policymakers and understand drivers of this increase, we estimated the number of people with opioid dependence aged 15-64 from 2014/15 to 2019/20. DESIGN: We fitted a Bayesian multi-parameter estimation of prevalence (MPEP) model, using adverse event rates to estimate prevalence of opioid dependence jointly from Opioid Agonist Therapy (OAT), opioid-related mortality and hospital admissions data. Estimates are stratified by age group, sex and year. SETTING: Scotland, 2014/15 to 2019/20. PARTICIPANTS: People with opioid dependence and potential to benefit from OAT, whether ever treated or not. Using data from the Scottish Public Health Drug Linkage Programme, we identified a baseline cohort of individuals who had received OAT within the last 5 years, and all opioid-related deaths and hospital admissions (whether among or outside of this cohort). MEASUREMENTS: Rates of each adverse event type and (unobserved) prevalence were jointly modelled. FINDINGS: The estimated number and prevalence of people with opioid dependence in Scotland in 2019/20 was 47 100 (95% Credible Interval [CrI] 45 700 to 48 600) and 1.32% (95% CrI 1.28% to 1.37%). Of these, 61% received OAT during 2019/20. Prevalence in Greater Glasgow and Clyde was estimated as 1.77% (95% CrI 1.69% to 1.85%). There was weak evidence that overall prevalence fell slightly from 2014/15 (change -0.07%, 95% CrI -0.14% to 0.00%). The population of people with opioid dependence is ageing, with the estimated number of people aged 15-34 reducing by 5100 (95% CrI 3800 to 6400) and number aged 50-64 increasing by 2800 (95% CrI 2100 to 3500) between 2014/15 and 2019/20. CONCLUSIONS: The prevalence of opioid dependence in Scotland remained high but was relatively stable, with only weak evidence of a small reduction, between 2014/15 and 2019/20. Increased numbers of opioid-related deaths can be attributed to increased risk among people with opioid dependence, rather than increasing prevalence.

2.
Front Immunol ; 15: 1345499, 2024.
Article in English | MEDLINE | ID: mdl-38469293

ABSTRACT

Immune responses to both SARS-CoV-2 infection and its associated vaccines have been highly variable within the general population. The increasing evidence of long-lasting symptoms after resolution of infection, called post-acute sequelae of COVID-19 (PASC) or "Long COVID," suggests that immune-mediated mechanisms are at play. Closely related endemic common human coronaviruses (hCoV) can induce pre-existing and potentially cross-reactive immunity, which can then affect primary SARS-CoV-2 infection, as well as vaccination responses. The influence of pre-existing immunity from these hCoVs, as well as responses generated from original CoV2 strains or vaccines on the development of new high-affinity responses to CoV2 antigenic viral variants, needs to be better understood given the need for continuous vaccine adaptation and application in the population. Due in part to thymic involution, normal aging is associated with reduced naïve T cell compartments and impaired primary antigen responsiveness, resulting in a reliance on the pre-existing cross-reactive memory cell pool which may be of lower affinity, restricted in diversity, or of shorter duration. These effects can also be mediated by the presence of down-regulatory anti-idiotype responses which also increase in aging. Given the tremendous heterogeneity of clinical data, utilization of preclinical models offers the greatest ability to assess immune responses under a controlled setting. These models should now involve prior antigen/viral exposure combined with incorporation of modifying factors such as age on immune responses and effects. This will also allow for mechanistic dissection and understanding of the different immune pathways involved in both SARS-CoV-2 pathogen and potential vaccine responses over time and how pre-existing memory responses, including potential anti-idiotype responses, can affect efficacy as well as potential off-target effects in different tissues as well as modeling PASC.


Subject(s)
COVID-19 , Vaccines , Humans , Post-Acute COVID-19 Syndrome , SARS-CoV-2 , Aging , Immunoglobulin Idiotypes
5.
JCI Insight ; 8(18)2023 09 22.
Article in English | MEDLINE | ID: mdl-37737264

ABSTRACT

Bystander activation of memory T cells occurs via cytokine signaling alone in the absence of T cell receptor (TCR) signaling and provides a means of amplifying T cell effector responses in an antigen-nonspecific manner. While the role of Programmed Cell Death Protein 1 (PD-1) on antigen-specific T cell responses is extensively characterized, its role in bystander T cell responses is less clear. We examined the role of the PD-1 pathway during human and mouse non-antigen-specific memory T cell bystander activation and observed that PD-1+ T cells demonstrated less activation and proliferation than activated PD-1- populations in vitro. Higher activation and proliferative responses were also observed in the PD-1- memory population in both mice and patients with cancer receiving high-dose IL-2, mirroring the in vitro phenotypes. This inhibitory effect of PD-1 could be reversed by PD-1 blockade in vivo or observed using memory T cells from PD-1-/- mice. Interestingly, increased activation through abrogation of PD-1 signaling in bystander-activated T cells also resulted in increased apoptosis due to activation-induced cell death (AICD) and eventual T cell loss in vivo. These results demonstrate that the PD-1/PD-Ligand 1 (PD-L1) pathway inhibited bystander-activated memory T cell responses but also protected cells from AICD.


Subject(s)
Lymphocyte Activation , Programmed Cell Death 1 Receptor , Humans , Animals , Mice , Cytokines , Memory T Cells , Phenotype
6.
Front Immunol ; 13: 1012016, 2022.
Article in English | MEDLINE | ID: mdl-36776393

ABSTRACT

Introduction: The incidence of obesity, a condition characterized by systemic chronic inflammation, has reached pandemic proportions and is a poor prognostic factor in many pathologic states. However, its role on immune parameters has been diverse and at times contradictory. We have previously demonstrated that obesity can result in what has been called the "obesity paradox" which results in increased T cell exhaustion, but also greater efficacy of immune checkpoint blockade in cancer treatment. Methods: The role of obesity, particularly in the context of aging, has not been robustly explored using preclinical models. We therefore evaluated how age impacts the immune environment on T cell development and function using diet-induced obese (DIO) mice. Results: We observed that DIO mice initially displayed greater thymopoiesis but then developed greater thymic involution over time compared to their lean counterparts. Both aging and obesity resulted in increased T cell memory conversion combined with increased expression of T cell exhaustion markers and Treg expansion. This increased T cell immunosuppression with age then resulted in a loss of anti-tumor efficacy by immune checkpoint inhibitors (ICIs) in older DIO mice compared to the younger DIO counterparts. Discussion: These results suggest that both aging and obesity contribute to T cell dysfunction resulting in increased thymic involution. This combined with increased T cell exhaustion and immunosuppressive parameters affects immunotherapy efficacy reducing the advantage of obesity in cancer immunotherapy responses.


Subject(s)
T-Cell Exhaustion , Thymus Gland , Mice , Animals , Aging , Obesity , Cell Differentiation , Mice, Obese
7.
Blood Adv ; 5(20): 4219-4232, 2021 10 26.
Article in English | MEDLINE | ID: mdl-34496010

ABSTRACT

Natural killer (NK) cells are involved in innate defense against viral infection and cancer. NK cells can be divided into subsets based on the ability of different receptors to bind to major histocompatibility (MHC) class 1 molecules, resulting in differential responses upon activation in a process called "licensing" or "arming." NK cells expressing receptors that bind self-MHC are considered licensed due to an augmented effector lytic function capability compared with unlicensed subsets. However, we demonstrated that unlicensed NK subsets instead positively regulate the adaptive T-cell response during viral infections that are related to localization and cytokine production. In this study, the differential effects of the two types of NK subsets were contingent on the environment in viral infection and hematopoietic stem cell transplantation (HSCT) models. Infection of mice with high-dose (HD) murine cytomegalovirus (MCMC) led to a loss of licensing-associated differences, as compared with mice with low-dose (LD) infection: the unlicensed NK subset no longer localized in lymph nodes (LNs), but instead remained at the site of infection. Similarly, the patterns observed during HD infection paralleled the phenotypes of both human and mouse NK cells in an HSCT setting where NK cells exhibit an activated phenotype. However, in contrast to the effects of subset depletion in T-cell replete models, the licensed NK cell subsets still dominated antiviral responses after HSCT. Overall, our results highlight the intricate tuning of NK cells and how it affects overall immune responses with regard to licensing patterns and their dependency on the level of stimulation and activation status.


Subject(s)
Hematopoietic Stem Cell Transplantation , Muromegalovirus , Animals , Humans , Killer Cells, Natural , Mice , Mice, Inbred C57BL
8.
Blood ; 138(24): 2583-2588, 2021 12 16.
Article in English | MEDLINE | ID: mdl-34424962

ABSTRACT

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a potential curative option for treating a variety of hematologic diseases, but acute and chronic graft-versus-host disease (GVHD) remain major barriers limiting efficacy. Acute gut GVHD occurs with marked increases in proinflammatory cytokines (including TNF and IL-6), which we recently demonstrated was exacerbated in obesity resulting in severe gastrointestinal pathology. Given the pleiotropic and overlapping effects of these 2 cytokines, we assessed the impact of dual TNF and IL-6R blockade on GVHD as well as graft-versus tumor (GVT) effects in different mouse GVHD models. Early administration of combined blockade resulted in greater protection and survival from acute gut GVHD compared with single blockade regimens and even development of later chronic skin GVHD. Importantly, double cytokine blockade preserved GVT effects reinforcing that GVT and GVHD can be delineated and may result in greater efficacy in allo-HSCT.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Graft vs Host Disease/prevention & control , Hematopoietic Stem Cell Transplantation , Receptors, Interleukin-6/antagonists & inhibitors , Tumor Necrosis Factor Inhibitors/therapeutic use , Animals , Antibodies, Monoclonal/therapeutic use , Disease Models, Animal , Etanercept/therapeutic use , Female , Graft vs Tumor Effect/drug effects , Hematopoietic Stem Cell Transplantation/methods , Humans , Mice, Inbred BALB C , Mice, Inbred C57BL , Transplantation, Homologous/methods
9.
Australas J Ultrasound Med ; 22(1): 32-39, 2019 Feb.
Article in English | MEDLINE | ID: mdl-34760534

ABSTRACT

Point-of-care ultrasound, or PoCUS, where imaging is undertaken at the bedside, clinic or emergency department (ED) by the clinician overseeing treatment, is a rapid form of assessment that may be undertaken alongside or as an alternative to traditional, formal ultrasound performed by a radiology service. PoCUS reduces the time to diagnosis, thus allowing lifesaving treatment to be initiated. This is particularly relevant in Obstetrics and Gynaecology (OBGYN), where delayed diagnosis of pregnancy complications is often fatal or highly debilitating to the mother or fetus. The literature suggests that PoCUS is particularly useful in areas that are inadequately resourced, as it is relatively cheap and accessible. High-quality training is essential to ensure that the staff performing the scans are adequately qualified to deliver the service. Clinicians who perform PoCUS in their practice should be aware of the appropriate indications, as well as when to refer for formal imaging.

10.
Math Biosci ; 244(2): 201-12, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23743207

ABSTRACT

This paper develops an optimal control framework for an ordinary differential equation model to investigate the introduction of sterile mosquitoes to reduce the incidence of mosquito-borne diseases. Existence of a solution given an optimal strategy and the optimal control is determined in association with the negative effects of the disease on the population while minimizing the cost due to this control mechanism. Numerical simulations have shown the importance of effects of the bounds on the release of sterile mosquitoes and the bounds on the likelihood of egg maturation. The optimal strategy is to maximize the use of habitat modification or insecticide. A combination of techniques leads to a more rapid elimination of the wild mosquito population.


Subject(s)
Culicidae/pathogenicity , Ecosystem , Models, Biological , Pest Control, Biological/methods , Animals , Infertility/chemically induced , Parasitic Diseases/etiology , Parasitic Diseases/prevention & control , Pest Control, Biological/economics
11.
Stem Cells ; 28(8): 1368-78, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20506112

ABSTRACT

Primordial germ cells (PGCs) are the embryonic precursors of gametes in the adult organism, and their development, differentiation, and survival are regulated by a combination of growth factors collectively known as the germ cell niche. Although many candidate niche components have been identified through studies on mouse PGCs, the growth factor composition of the human PGC niche has not been studied extensively. Here we report a detailed analysis of the expression of components of the bone morphogenetic protein (BMP) signaling apparatus in the human fetal ovary, from postmigratory PGC proliferation to the onset of primordial follicle formation. We find developmentally regulated and reciprocal patterns of expression of BMP2 and BMP4 and identify germ cells to be the exclusive targets of ovarian BMP signaling. By establishing long-term cultures of human fetal ovaries in which PGCs are retained within their physiological niche, we find that BMP4 negatively regulates postmigratory PGC numbers in the human fetal ovary by promoting PGC apoptosis. Finally, we report expression of both muscle segment homeobox (MSX)1 and MSX2 in the human fetal ovary and reveal a selective upregulation of MSX2 expression in human fetal ovary in response to BMP4, suggesting this gene may act as a downstream effector of BMP-induced apoptosis in the ovary, as in other systems. These data reveal for the first time growth factor regulation of human PGC development in a physiologically relevant context and have significant implications for the development of cultures systems for the in vitro maturation of germ cells, and their derivation from pluripotent stem cells.


Subject(s)
Bone Morphogenetic Proteins/metabolism , Fetus/cytology , Fetus/metabolism , Germ Cells/cytology , Ovary/cytology , Ovary/metabolism , Apoptosis/genetics , Apoptosis/physiology , Bone Morphogenetic Protein 2/genetics , Bone Morphogenetic Protein 2/metabolism , Bone Morphogenetic Protein 4/genetics , Bone Morphogenetic Protein 4/metabolism , Bone Morphogenetic Protein 7/genetics , Bone Morphogenetic Protein 7/metabolism , Bone Morphogenetic Proteins/genetics , Cell Proliferation , Female , Fluorescent Antibody Technique , Germ Cells/metabolism , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Immunohistochemistry , MSX1 Transcription Factor/genetics , MSX1 Transcription Factor/metabolism , Ovary/embryology , Pregnancy , Reverse Transcriptase Polymerase Chain Reaction , Tissue Culture Techniques
12.
Dev Dyn ; 239(4): 1211-9, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20175187

ABSTRACT

The tropomyosin-related kinase (Trk) B neurotrophin receptor is essential for ovarian germ cell survival and primordial follicle formation, but the contributions of its ligands, brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT4), are unknown. We have investigated their expression and regulation in developing human and mouse ovaries. BDNF expression increased with increasing gestation, expression of human NTF4 and of both Ntf5 and Bdnf in the mouse was unchanged. Bdnf expression was dramatically lower than Ntf5 in the mouse, but levels were comparable in the human. Human fetal ovarian somatic cells expressed BDNF. Activin A selectively regulated BDNF and Ntf5 expression in human and mouse, respectively, identifying an oocyte/somatic signaling pathway which might mediate the pro-survival effects of activin. These data reveal that expression and regulation of the TrkB ligands are differentially controlled in the developing ovaries of humans and mice, and identify BDNF as a potential regulator of germ cell fate in the human fetal ovary.


Subject(s)
Activins/pharmacology , Brain-Derived Neurotrophic Factor/genetics , Gene Expression Regulation, Developmental/drug effects , Nerve Growth Factors/genetics , Ovary/embryology , Animals , Brain-Derived Neurotrophic Factor/metabolism , Cells, Cultured , Female , Fetus/drug effects , Fetus/metabolism , Gestational Age , Humans , Mice , Mice, Inbred C57BL , Nerve Growth Factors/metabolism , Ovary/drug effects , Ovary/metabolism , Ovum/metabolism , Ovum/physiology
13.
Fertil Steril ; 93(7): 2348-53, 2010 May 01.
Article in English | MEDLINE | ID: mdl-19324354

ABSTRACT

OBJECTIVE: To investigate expression of N- and E-cadherin in the developing human ovary. DESIGN: The expression of N- and E-cadherin was analyzed in 18 human fetal ovaries between 8 and 20 weeks' gestation using immunohistochemistry. Fetal human male and rat urogenital tracts were used for comparison of expression. SETTING: Academic research institute. PATIENT(S): Women undergoing termination of pregnancy. INTERVENTION(S): Immunofluorescent analysis of cadherin expression. RESULT(S): In fetal ovary, N- and E-cadherins were expressed at all gestations with overlapping but not identical patterns. Expression was associated with germ cells and adjacent somatic cells, including within newly formed primordial follicles, but neither cadherin was expressed in the somatic cell cords. The epithelia of the müllerian and wolffian ducts expressed only N- and E-cadherin, respectively, in a mutually exclusive fashion. This pattern of cadherin expression was found to be conserved between human and rat fetuses of both genders. CONCLUSION(S): The demonstration of N- and E-cadherin expression in the human fetal ovary indicates likely roles in gonadal development from germ cell proliferation to primordial follicle formation, as well as in the development of the urogenital ducts of both genders. This is consistent with animal studies identifying cadherins as key regulators of early germ cell development.


Subject(s)
Antigens, CD/metabolism , Cadherins/metabolism , Ovary/embryology , Urogenital System/embryology , Animals , Cell Proliferation , Female , Fetus/metabolism , Fluorescent Antibody Technique , Germ Cells/growth & development , Germ Cells/metabolism , Germ Cells/physiology , Gestational Age , Humans , Male , Mullerian Ducts/embryology , Mullerian Ducts/metabolism , Ovary/metabolism , Pregnancy , Rats , Rats, Wistar , Urogenital System/metabolism , Wolffian Ducts/embryology , Wolffian Ducts/metabolism
14.
J Clin Endocrinol Metab ; 94(10): 4053-60, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19602557

ABSTRACT

CONTEXT: The formation of primordial follicles occurs during fetal life yet is critical to the determination of adult female fertility. Prior to this stage, germ cells proliferate, enter meiosis, and associate with somatic cells. Growth and survival factors implicated in these processes include activin A (INHBA), the neurotrophins BDNF and NT4 (NTF5), and MCL1. The prostaglandins have pleiotrophic roles in reproduction, notably in ovulation and implantation, but there are no data regarding roles for prostaglandins in human fetal ovarian development. OBJECTIVE: The aim of the study was to investigate a possible role for prostaglandin (PG) E(2) in human fetal ovary development. DESIGN: In vitro analysis of ovarian development between 8 and 20 wk gestation was performed. MAIN OUTCOME MEASURE(S): The expression patterns of PG synthesis enzymes and the PGE(2) receptors EP2 and EP4 in the ovary were assessed, and downstream effects of PGE(2) on gene expression were analyzed. RESULTS: Ovarian germ cells express the PG synthetic enzymes COX2 and PTGES as well as the EP2 and EP4 receptors, whereas COX1 is expressed by ovarian somatic cells. Treatment in vitro with PGE(2) increased the expression of BDNF mRNA 1.7 +/- 0.16-fold (P = 0.004); INHBA mRNA, 2.1 +/- 0.51-fold (P = 0.04); and MCL1 mRNA, 1.15 +/- 0.06-fold (P = 0.04), but not that of OCT4, DAZL, VASA, NTF5, or SMAD3. CONCLUSIONS: These data indicate novel roles for PGE(2) in the regulation of germ cell development in the human ovary and show that these effects may be mediated by the regulation of factors including BDNF, activin A, and MCL1.


Subject(s)
Dinoprostone/metabolism , Fetus , Oocytes/growth & development , Oocytes/metabolism , Ovary/growth & development , Ovary/metabolism , Activins/metabolism , Adult , Brain-Derived Neurotrophic Factor/metabolism , Female , Gene Expression Regulation, Developmental , Humans , Immunohistochemistry , Intramolecular Oxidoreductases/metabolism , Myeloid Cell Leukemia Sequence 1 Protein , Oocytes/enzymology , Ovary/enzymology , Pregnancy , Prostaglandin-E Synthases , Proto-Oncogene Proteins c-bcl-2/metabolism , Receptors, Prostaglandin E/metabolism , Receptors, Prostaglandin E, EP2 Subtype , Receptors, Prostaglandin E, EP4 Subtype , Reverse Transcriptase Polymerase Chain Reaction
15.
Math Biosci Eng ; 6(3): 451-67, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19566120

ABSTRACT

A mathematical model is used to investigate the effectiveness of the chemotherapy drug Topotecan against neuroblastoma. Optimal control theory is applied to minimize the tumor volume and the amount of drug utilized. The model incorporates a state constraint that requires the level of circulating neutrophils (white blood cells that form an integral part of the immune system) to remain above an acceptable value. The treatment schedule is designed to simultaneously satisfy this constraint and achieve the best results in fighting the tumor. Existence and uniqueness of the solution of the optimality system, which is the state system coupled with the adjoint system, is established. Numerical simulations are given to demonstrate the behavior of the tumor and the immune system components represented in the model.


Subject(s)
Antineoplastic Agents/pharmacokinetics , Models, Immunological , Neuroblastoma/immunology , Neutrophils/immunology , Topotecan/pharmacokinetics , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/therapeutic use , Child , Computer Simulation , Drug Administration Schedule , Granulocyte Colony-Stimulating Factor/immunology , Humans , Neuroblastoma/drug therapy , Neutrophils/drug effects , Topotecan/administration & dosage , Topotecan/therapeutic use
16.
Dev Biol ; 314(1): 189-99, 2008 Feb 01.
Article in English | MEDLINE | ID: mdl-18166170

ABSTRACT

Ovarian germ cell survival is dependent upon the formation of primordial follicles, which occurs during fetal life in the human. Activin contributes to germ cell proliferation and survival at this time. SMADs2 and 3 are central elements in the activin signalling pathway and thus indicate sites of activin action. We have investigated the expression and localisation of SMADs2 and 3 in the fetal ovary between 14 and 20 weeks gestation, i.e. preceding and during primordial follicle formation. SMAD3 mRNA expression increased 1.9 fold (P=0.02). SMAD2 and 3 proteins were localised by immunofluorescence to the nuclei of three distinct populations of somatic cells: (a) stromal cells between clusters of germ cells; (b) some somatic cells intermingled with activin beta A-expressing germ cells; (c) pre-granulosa cells surrounding primordial follicles. Germ cells did not express SMAD2 or 3. Activin A increased and follistatin decreased phosphorylation of SMAD2/3 in vitro, and activin increased SMAD2 and decreased KITLG mRNA expression. It therefore appears that somatic cells are the targets for activin signalling in the developing ovary. The effects of activin on germ cells are indirect and include mediation by the kit ligand/c-Kit pathway, rather than being an autocrine germ cell effect.


Subject(s)
Activins/metabolism , Germ Cells/metabolism , Ovary/metabolism , Smad2 Protein/metabolism , Smad3 Protein/metabolism , Stem Cell Factor/biosynthesis , Female , Fetus/metabolism , Follistatin/metabolism , Gene Expression Regulation, Developmental , Gestational Age , Humans , Ovary/cytology , Ovary/embryology , Phosphorylation , Signal Transduction
17.
Chembiochem ; 8(8): 885-95, 2007 May 25.
Article in English | MEDLINE | ID: mdl-17458915

ABSTRACT

We have identified a putative membrane-interacting domain preceding the transmembrane domain of the Herpes simplex virus type 1 (HSV-1) glycoprotein H (gH). Peptides derived from this region interact strongly with membranes and show a high tendency to partition at the interface. This region is predicted to bind at the membrane interface by adopting an alpha helical structure. Peptides representing either the HSV-1 gH pretransmembrane region or a scrambled control with a different hydrophobic profile at the point of interface have been studied. The peptides derived from this domain of gH induce the fusion of liposomal membranes, adopt helical conformations in membrane mimetic environments and are able to inhibit HSV-1 infectivity. The pretransmembrane region appears to be a common feature in viral fusion proteins of several virus families, and such a feature might be related to their fusogenic function. The identification of membrane-interacting regions capable of modifying the biophysical properties of phospholipid membranes lends weight to the view that such domains might function directly in the fusion process and could facilitate the future development of HSV-1 entry inhibitors.


Subject(s)
Simplexvirus/chemistry , Viral Envelope Proteins/chemistry , Virus Internalization , Amino Acid Sequence , Cell Membrane/chemistry , Cell Membrane/physiology , Hydrophobic and Hydrophilic Interactions , Lipids/chemistry , Molecular Sequence Data , Peptide Fragments/chemistry , Peptide Fragments/pharmacology , Sequence Homology, Amino Acid , Simplexvirus/drug effects
18.
J Gen Virol ; 87(Pt 5): 1085-1097, 2006 May.
Article in English | MEDLINE | ID: mdl-16603508

ABSTRACT

Human herpesviruses enter cells by fusion of their own membrane with a cellular membrane through the concerted action of multiple viral proteins and cellular receptors. Two conserved viral glycoproteins, gB and gH, are required for herpes simplex virus type 1 (HSV-1)-mediated membrane fusion, but little is known of how these proteins cooperate during entry. Both glycoproteins were shown to contain heptad repeat (HR) sequences predicted to form alpha-helical coiled coils, and the inhibitory activity against infection of four sets of synthetic peptides corresponding to HR1 and HR2 of gB and gH was tested. The interactions between these HR peptides were also investigated by circular dichroism, native polyacrylamide-gel electrophoresis and size exclusion high-performance liquid chromatography. gH coiled-coil peptides were more effective than gB coiled-coils peptides in inhibiting virus infectivity. The peptides did not impair fusion when added to cells immediately after infection. In contrast, inhibition of infection was observed, albeit to various extents, when peptides were added to virus before or during inoculation. The results of biophysical analyses were indicative of the existence of an interaction between HR1 and HR2 of gH and suggest that the HRs of gB and gH do not interact with each other.


Subject(s)
Peptides/pharmacology , Simplexvirus/chemistry , Simplexvirus/drug effects , Viral Envelope Proteins/chemistry , Amino Acid Sequence , Animals , Cell Fusion , Chlorocebus aethiops , Herpes Simplex/virology , Membrane Fusion , Molecular Sequence Data , Peptides/chemical synthesis , Peptides/genetics , Protein Binding , Protein Structure, Secondary , Protein Structure, Tertiary/genetics , Simplexvirus/physiology , Vero Cells , Viral Envelope Proteins/genetics , Virus Replication/drug effects
19.
J Pharm Biomed Anal ; 27(1-2): 191-200, 2002 Jan 01.
Article in English | MEDLINE | ID: mdl-11682226

ABSTRACT

Studies on the capabilities of flow injection analysis (FIA) combined with on-line characterisation of model compounds via a combination of diode array UV, 1H-NMR, FT-IR spectroscopy and mass spectrometry are described. Using this combination of spectrometers enabled the on-flow collection of UV, 1H-NMR, IR and MS for a range of model compounds. Samples were introduced into the system as solutions in deuterium oxide in concentrations ranging from 1.4 to 8.4 mg ml(-1). A sample volume of 100 microl was used for FIA at a flow rate of 1 ml min(-1). From these studies a practical working quantity of ca. 140 microg/sample of analyte was determined which provided characteristic spectra.


Subject(s)
Flow Injection Analysis/methods , Spectrum Analysis/methods , 4-Aminobenzoic Acid/analysis , Flow Injection Analysis/instrumentation , Magnetic Resonance Spectroscopy/methods , Mass Spectrometry/methods , Spectrophotometry, Infrared/methods , Spectrophotometry, Ultraviolet/methods , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis/instrumentation
SELECTION OF CITATIONS
SEARCH DETAIL
...