Immunoprofiling of the Tryptophan-Rich Antigen Family in Plasmodium vivax

Tryptophan-rich antigens (TRAgs) are an antigen family that has been identified in human and rodent malaria parasites. TRAgs have been proposed as candidate antigens for potential vaccines. ThePlasmodium vivaxTRAg (PvTRAg) family includes 36 members. Each PvTRAg contains a tryptophan-rich (TR) domain in the C-terminal region. In this study, we recombinantly expressed all 36 PvTRAgs using a cell-free expression system, and, for the first time, profiled the IgG antibody responses against all PvTRAgs in the sera from 96 vivax malaria patients and 40 healthy individuals using protein microarray technology. The mean seropositive rate for all PvTRAgs was 60.3%. Among them, nine PvTRAgs were newly identified in this study and showed a seropositive rate of >50%. Five of them, PvTRAg_13, PvTRAg_15, PvTRAg_16, PvTRAg_26, and PvTRAg_29, produced higher levels of IgG antibody, even in low-endemicity countries. In addition, the results of an immunofluorescence analysis suggest that PvTRAgs are, at least in part, associated with caveola-vesicle complexes, a unique structure ofP. vivax-infected erythrocytes. The mechanism of formation and the function of these abundant membrane structures are not known. Further investigation aimed at determining the functions of these proteins would lead to a better understanding of the blood-stage biology ofP. vivax.

Download Full-text

Lausannevirus Encodes a Functional Dihydrofolate Reductase Susceptible to Proguanil

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02573-16 ◽

2017 ◽

Vol 61 (4) ◽

Author(s):

L. Mueller ◽

P. M. Hauser ◽

F. Gauye ◽

G. Greub

Keyword(s):

Dihydrofolate Reductase ◽

Expression System ◽

Open Reading Frames ◽

Dna Viruses ◽

Content Type ◽

The Family ◽

Nucleocytoplasmic Large Dna Viruses ◽

First Time ◽

Reading Frames

ABSTRACT Lausannevirus belongs to the family Marseilleviridae within the group of nucleocytoplasmic large DNA viruses (NCLDVs). These giant viruses exhibit unique features, including a large genome, ranging from 100 kb to 2.5 Mb and including from 150 to more than 2,500 genes, as well as the presence of genes coding for proteins involved in transcription and translation. The large majority of Lausannevirus open reading frames have unknown functions. Interestingly, a bifunctional dihydrofolate reductase-thymidylate synthase (DHFR-TS) is encoded in the Lausannevirus genome. The enzyme plays central roles in DNA precursor biosynthesis. DHFR is the pharmacological target of antifolates, such as trimethoprim, pyrimethamine, and proguanil. First, the functionality of Lausannevirus DHFR-TS was demonstrated by the successful complementation of a DHFR-deficient Saccharomyces cerevisiae strain with a plasmid expressing the heterologous gene. Additionally, using this heterologous expression system, we demonstrated the in vitro susceptibility of Lausannevirus DHFR-TS to proguanil and its resistance to pyrimethamine and trimethoprim. Proguanil may provide a unique and useful treatment if Lausannevirus proves to be a human pathogen. To our knowledge, this is the first time that a DHFR-TS has been described and characterized in an NCLDV.

Download Full-text

Profiling Humoral Immune Responses to Clostridium difficile-Specific Antigens by Protein Microarray Analysis

Clinical and Vaccine Immunology ◽

10.1128/cvi.00190-15 ◽

2015 ◽

Vol 22 (9) ◽

pp. 1033-1039 ◽

Cited By ~ 8

Author(s):

Ola H. Negm ◽

Mohamed R. Hamed ◽

Elizabeth M. Dilnot ◽

Clifford C. Shone ◽

Izabela Marszalowska ◽

...

Keyword(s):

Clostridium Difficile ◽

Immune Responses ◽

Protein Microarray ◽

Enzyme Linked Immunosorbent Assay ◽

Protein Antigens ◽

Igg Antibody ◽

Content Type ◽

Humoral Immune ◽

Humoral Immune Responses ◽

Specific Antigens

ABSTRACTClostridium difficileis an anaerobic, Gram-positive, and spore-forming bacterium that is the leading worldwide infective cause of hospital-acquired and antibiotic-associated diarrhea. Several studies have reported associations between humoral immunity and the clinical course ofC. difficileinfection (CDI). Host humoral immune responses are determined using conventional enzyme-linked immunosorbent assay (ELISA) techniques. Herein, we report the first use of a novel protein microarray assay to determine systemic IgG antibody responses against a panel of highly purifiedC. difficile-specific antigens, including native toxins A and B (TcdA and TcdB, respectively), recombinant fragments of toxins A and B (TxA4 and TxB4, respectively), ribotype-specific surface layer proteins (SLPs; 001, 002, 027), and control proteins (tetanus toxoid andCandida albicans). Microarrays were probed with sera from a total of 327 individuals with CDI, cystic fibrosis without diarrhea, and healthy controls. For all antigens, precision profiles demonstrated <10% coefficient of variation (CV). Significant correlation was observed between microarray and ELISA in the quantification of antitoxin A and antitoxin B IgG. These results indicate that microarray is a suitable assay for defining humoral immune responses toC. difficileprotein antigens and may have potential advantages in throughput, convenience, and cost.

Download Full-text

Confirmed Plasmodium vivax Resistance to Chloroquine in Central Vietnam

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00791-15 ◽

2015 ◽

Vol 59 (12) ◽

pp. 7411-7419 ◽

Cited By ~ 17

Author(s):

Pham Vinh Thanh ◽

Nguyen Van Hong ◽

Nguyen Van Van ◽

Melva Louisa ◽

Kevin Baird ◽

...

Keyword(s):

Plasmodium Vivax ◽

Cumulative Risk ◽

Artemisinin Resistance ◽

Blood Levels ◽

Radical Cure ◽

Blood Concentrations ◽

Content Type ◽

Central Vietnam ◽

Almost All ◽

First Time

ABSTRACTPlasmodium vivaxresistance to chloroquine (CQ) is currently reported in almost all countries whereP. vivaxis endemic. In Vietnam, despite a first report onP. vivaxresistance to chloroquine published in the early 2000s,P. vivaxwas still considered sensitive to CQ. Between May 2009 and December 2011, a 2-year cohort study was conducted in central Vietnam to assess the recommended radical cure regimen based on a 10-day course of primaquine (0.5 mg/kg/day) together with 3 days of CQ (25 mg/kg). Here we report the results of the first 28-day follow-up estimating the cumulative risk ofP. vivaxrecurrences together with the corresponding CQ blood concentrations, among other endpoints. Out of 260 recruitedP. vivaxpatients, 240 completed treatment and were followed up to day 28 according to the WHO guidelines. Eight patients (3.45%) had a recurrentP. vivaxinfection, at day 14 (n= 2), day 21 (n= 1), and day 28 (n= 5). Chloroquine blood concentrations, available for 3/8 recurrent infections (days 14, 21, and 28), were above the MIC (>100 ng/ml whole blood) in all of these cases. Fever and parasitemia (both sexual and asexual stages) were cleared by day 3. Anemia was common at day 0 (35.8%), especially in children under 10 years (50%), and hemoglobin (Hb) recovery at day 28 was substantial among anemic patients (median change from day 0 to 28, +1.7 g/dl; interquartile range [IQR], +0.7 to +3.2). This report, based on CQ blood levels measured at the time of recurrences, confirms for the first timeP. vivaxCQ resistance in central Vietnam and calls for further studies using standardized protocols for accurately monitoring the extent and evolution ofP. vivaxresistance to chloroquine in Vietnam. These results, together with the mounting evidence of artemisinin resistance in central Vietnam, further highlight the increasing threat of antimalarial drug resistance to malaria elimination in Vietnam.

Download Full-text

Evaluation of antibody responses to the early transcribed membrane protein family in Plasmodium vivax

Parasites & Vectors ◽

10.1186/s13071-019-3846-4 ◽

2019 ◽

Vol 12 (1) ◽

Author(s):

Seong-Kyun Lee ◽

Jin-Hee Han ◽

Ji-Hoon Park ◽

Kwon-Soo Ha ◽

Won Sun Park ◽

...

Keyword(s):

Membrane Protein ◽

Plasmodium Vivax ◽

Vaccine Development ◽

Protein Microarray ◽

Expression System ◽

Structural Features ◽

Igg Subclasses ◽

Antibody Responses ◽

Internal Space ◽

Protein Marker

Abstract Background Malaria parasites form intracellular membranes that separate the parasite from the internal space of erythrocytes, and membrane proteins from the parasites are exported to the host via the membrane. In our previous study, Plasmodium vivax early transcribed membrane protein (PvETRAMP) 11.2, an intracellular membrane protein that is highly expressed in blood-stage parasites, was characterized as a highly immunogenic protein in P. vivax malaria patients. However, the other PvETRAMP family proteins have not yet been investigated. In this study, PvETRAMPs were expressed and evaluated to determine their immunological profiles. Methods The protein structure and amino acid alignment were carried out using bioinformatics analysis software. A total of six PvETRAMP family proteins were successfully expressed and purified using a wheat germ cell free protein expression system and the purified proteins were used for protein microarray and immunization of mice. The localization of the protein was determined with serum against PvETRAMP4. IgG subclasses were assessed from the immunized mice. Results In silico analysis showed that P. vivax exhibits nine genes encoding the ETRAMP family. The ETRAMP family proteins are relatively small molecules with conserved structural features. A total of 6 recombinant ETRAMP proteins were successfully expressed and purified. The serum positivity of P. vivax malaria patients and healthy individuals was evaluated using a protein microarray method. Among the PvETRAMPs, ETRAMP4 showed the highest positivity rate of 62%, comparable to that of PvETRAMP11.2, which served as the positive control, and a typical export pattern of PvETRAMP4 was observed in the P. vivax parasite. The assessment of IgG subclasses in mice immunized with PvETRAMP4 showed high levels of IgG1 and IgG2b. PvETRAMP family proteins were identified and characterized as serological markers. Conclusions The relatively high antibody responses to PvETRAMP4 as well as the specific IgG subclasses observed in immunized mice suggest that the ETRAMP family is immunogenic in pathogens and can be used as a protein marker and for vaccine development.

Download Full-text

Neurosurgical workforce trends in the United States

Journal of Neurosurgery ◽

10.3171/jns.2005.102.2.0202 ◽

2005 ◽

Vol 102 (2) ◽

pp. 202-208 ◽

Cited By ~ 27

Author(s):

Oren N. Gottfried ◽

Richard L. Rovit ◽

A. John Popp ◽

Kristin L. Kraus ◽

Arlene Stolper Simon ◽

...

Keyword(s):

United States ◽

The United States ◽

Content Type ◽

The Past ◽

Time Period ◽

The Us ◽

The Mean ◽

First Time ◽

Second Period ◽

Fine Print

Object. The purpose of this study was to evaluate the US neurosurgery workforce by reviewing journal recruitment advertisements published during the past 10 years. Methods. The number of available academic and private neurosurgical staff positions was determined based on recruitment advertisements in the Journal of Neurosurgery and Neurosurgery for the 10-year period from 1994 to 2003. Advertisements were evaluated for practice venue, subspecialization, and location. The numbers of active neurosurgeons and graduating residents also were reviewed. The number of advertised neurosurgical positions increased from 141.6 ± 38.2 per year from 1994 through 1998 to 282.4 ± 13.6 per year from 1999 through 2003 (mean ± standard deviation, p < 0.05). The mean number of academic positions increased from 50.6 ± 11.1 to 95 ± 17.5 (p <0.05), and the mean number of private positions rose from 91 ± 30.4 to 187.4 ± 6.8 (p <0.05). Subspecialty positions represented a mean of only 15.6 ± 5% per year during the first time period and 18.8 ± 3% per year in the second period (p = 0.22), and therefore the majority of positions advertised continued to be those for generalists. The number of practicing neurosurgeons declined after 1998, and by 2002 it was less than it had been in 1991. The numbers of incoming and matriculating residents during the study period were static. Conclusions. The number of recruitment advertisements for neurosurgeons during the last 5 years has increased significantly, concomitant with a severe decline in the number of active neurosurgeons and a static supply of residents.

Download Full-text

A New MIC1-MAG1 Recombinant Chimeric Antigen Can Be Used Instead of the Toxoplasma gondii Lysate Antigen in Serodiagnosis of Human Toxoplasmosis

Clinical and Vaccine Immunology ◽

10.1128/cvi.05433-11 ◽

2011 ◽

Vol 19 (1) ◽

pp. 57-63 ◽

Cited By ~ 25

Author(s):

Lucyna Holec-Gąsior ◽

Bartłomiej Ferra ◽

Dorota Drapała ◽

Dariusz Lautenbach ◽

Józef Kur

Keyword(s):

Toxoplasma Gondii ◽

Expression System ◽

Chimeric Protein ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Content Type ◽

Metal Affinity ◽

Positive Serum ◽

First Time ◽

Microneme Protein

ABSTRACTThis study presents an evaluation of the MIC1 (microneme protein 1)-MAG1 (matrix antigen 1)Toxoplasma gondiirecombinant chimeric antigen for the serodiagnosis of human toxoplasmosis for the first time. The recombinant MIC1-MAG1 antigen was obtained as a fusion protein containing His tags at the N- and C-terminal ends using anEscherichia coliexpression system. After purification by metal affinity chromatography, the chimeric protein was tested for usefulness in an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-T. gondiiimmunoglobulin G (IgG). One hundred ten sera from patients at different stages of infection and 40 sera from seronegative patients were examined. The results obtained for the MIC1-MAG1 chimeric antigen were compared with those of IgG ELISAs using aToxoplasmalysate antigen (TLA), a combination of recombinant antigens (rMIC1ex2-rMAG1) and single recombinant proteins (rMIC1ex2 and rMAG1). The sensitivity of the IgG ELISA calculated from all of the positive serum samples was similar for the MIC1-MAG1 chimeric antigen (90.8%) and the TLA (91.8%), whereas the sensitivities of the other antigenic samples used were definitely lower, at 69.1% for the mixture of antigens, 75.5% for the rMIC1ex2, and 60% for rMAG1. This study demonstrates that the MIC1-MAG1 recombinant chimeric antigen can be used instead of the TLA in the serodiagnosis of human toxoplasmosis.

Download Full-text

Stock market drivers of retail investors’ sentiment – facets and new evidences from India

Rajagiri Management Journal ◽

10.1108/ramj-05-2020-0015 ◽

2020 ◽

Vol 14 (2) ◽

pp. 133-154

Author(s):

Ranjan Dasgupta ◽

Sandip Chattopadhyay

Keyword(s):

Stock Market ◽

Trading Volume ◽

Empirical Studies ◽

Investor Sentiment ◽

Content Type ◽

Primary Survey ◽

Retail Investors ◽

Research Gap ◽

The Mean ◽

First Time

Purpose The determinants of investors’ sentiment based on secondary stock market proxies in many empirical studies are reported. However, to the best of our knowledge, no study undertakes investor sentiment drivers developed from primary survey measures by constructing an investor sentiment index (ISI) in relation to market drivers to date. This study aims to fill this research gap by first developing the ISI for the Indian retail investors and then examining which of the stock market drivers impacts such sentiment. Design/methodology/approach The ISI is constructed using the mean scores of eight statements as formulated based on popular direct investor sentiment surveys undertaken across the world. Then, we use the multiple regression approach overall and for top 33.33% (high-sentiment) and bottom 33.33% (low-sentiment) investors based on the responses of 576 respondents on 18 statements (proxying eight study hypotheses) collected in 2016. Moreover, the demography-based classification based investors’ sentiment is examined to make our results more robust and in-depth. Findings On an overall basis, the IPO activities/issues and information certainty, trading volume and momentum and institutional investors’ investment activities market drivers significantly and positively impact retail investors is examined. However, only IPO activities/issues and information certainty influences both high- and low-sentiment investors. It is intriguing to report that nature of the stock markets show conflicting results for high- (negative significant) and low- (positive significant) sentiment investors. Originality/value The construction of the ISI from primary survey measure is for the first time in Indian context in relation to investigating the stock market drivers influential to retail investors’ sentiment. In addition, hypothesized market drivers are also unique, each representing different fundamental and technical characteristics associated with the Indian market.

Download Full-text

Baculovirus-Vectored Multistage Plasmodium vivax Vaccine Induces Both Protective and Transmission-Blocking Immunities against Transgenic Rodent Malaria Parasites

Infection and Immunity ◽

10.1128/iai.02040-14 ◽

2014 ◽

Vol 82 (10) ◽

pp. 4348-4357 ◽

Cited By ~ 24

Author(s):

Masanori Mizutani ◽

Mitsuhiro Iyori ◽

Andrew M. Blagborough ◽

Shinya Fukumoto ◽

Tomohiro Funatsu ◽

...

Keyword(s):

Fusion Protein ◽

Plasmodium Vivax ◽

Mammalian Cells ◽

Expression System ◽

Viral Envelope ◽

Vaccine Platform ◽

Transmission Blocking ◽

Content Type ◽

Sexual Stages

ABSTRACTA multistage malaria vaccine targeting the pre-erythrocytic and sexual stages ofPlasmodiumcould effectively protect individuals against infection from mosquito bites and provide transmission-blocking (TB) activity against the sexual stages of the parasite, respectively. This strategy could help prevent malaria infections in individuals and, on a larger scale, prevent malaria transmission in communities of endemicity. Here, we describe the development of a multistagePlasmodium vivaxvaccine which simultaneously expressesP. vivaxcircumsporozoite protein (PvCSP) and P25 (Pvs25) protein of this species as a fusion protein, thereby acting as a pre-erythrocytic vaccine and a TB vaccine, respectively. A new-concept vaccine platform based on the baculovirus dual-expression system (BDES) was evaluated. The BDES-Pvs25-PvCSP vaccine displayed correct folding of the Pvs25-PvCSP fusion protein on the viral envelope and was highly expressed upon transduction of mammalian cellsin vitro. This vaccine induced high levels of antibodies to Pvs25 and PvCSP and elicited protective (43%) and TB (82%) efficacies against transgenicP. bergheiparasites expressing the correspondingP. vivaxantigens in mice. Our data indicate that our BDES, which functions as both a subunit and DNA vaccine, can offer a promising multistage vaccine capable of delivering a potent antimalarial pre-erythrocytic and TB response via a single immunization regimen.

Download Full-text

Butterfly-effect for massively separated flows

Engineering Computations ◽

10.1108/ec-11-2012-0262 ◽

2014 ◽

Vol 31 (4) ◽

pp. 742-757 ◽

Cited By ~ 2

Author(s):

Rainald Lohner ◽

Dominic Britto ◽

Alexander Michailski ◽

Eberhard Haug

Keyword(s):

Large Scale ◽

Separated Flows ◽

Wind Engineering ◽

Content Type ◽

Massively Separated Flows ◽

Time Requirements ◽

The Mean ◽

Butterfly Effect ◽

First Time ◽

Inflow Conditions

Purpose – During a routine benchmarking and scalability study of CFD codes for typical large-scale wind engineering runs, it was observed that the resulting loads for buildings varied considerably with the number of parallel processors employed. The differences remained very small at the beginning of a typical run, and then grew progressively to a state of total dissimilitude. A “butterfly-effect” for such flows was suspected and later confirmed. The paper aims to discuss these issues. Design/methodology/approach – A series of numerical experiments was conducted for massively separated flows. The same geometry – a cube in front of an umbrella – was used to obtain the flowfields using different grids, different numbers of domains/processors, slightly different inflow conditions and different codes. Findings – In all of these cases the differences remained very small at the beginning of a typical run, they then grew progressively to a state of total dissimilitude. While the mean and maximum loads remained similar, the actual (deterministic) instantiations were completely different. The authors therefore suspect that for flows of this kind a “butterfly effect” is present, whereby even very small (roundoff) errors can have a pronounced effect on the actual deterministic instantiation of a flowfield. Research limitations/implications – This implies that for flows of this kind the CFD runs have to be carried out to much larger times than formerly expected (and done) in order to obtain statistically relevant ensembles. Practical implications – For practical calculations this implies running to much larger times in order to reach statistically relevant ensembles, with the associated much higher CPU time requirements. Originality/value – This is the first time such a finding has been reported in the numerical wind engineering context.

Download Full-text

Gamma knife radiosurgery in the management of cavernous sinus meningiomas

Journal of Neurosurgery ◽

10.3171/jns.2000.93.supplement_3.0068 ◽

2000 ◽

Vol 93 (supplement_3) ◽

pp. 68-73 ◽

Cited By ~ 112

Author(s):

Pierre-Hugues Roche ◽

Jean Régis ◽

Henry Dufour ◽

Henri-Dominique Fournier ◽

Christine Delsanti ◽

...

Keyword(s):

Mr Imaging ◽

Tumor Growth ◽

Gamma Knife ◽

Cavernous Sinus ◽

Gamma Knife Radiosurgery ◽

Surgical Removal ◽

Content Type ◽

Cavernous Sinus Meningioma ◽

The Mean ◽

Fine Print

Object. The authors sought to assess the functional tolerance and tumor control rate of cavernous sinus meningiomas treated by gamma knife radiosurgery (GKS). Methods. Between July 1992 and October 1998, 92 patients harboring benign cavernous sinus meningiomas underwent GKS. The present study is concerned with the first 80 consecutive patients (63 women and 17 men). Gamma knife radiosurgery was performed as an alternative to surgical removal in 50 cases and as an adjuvant to microsurgery in 30 cases. The mean patient age was 49 years (range 6–71 years). The mean tumor volume was 5.8 cm3 (range 0.9–18.6 cm3). On magnetic resonance (MR) imaging the tumor was confined in 66 cases and extensive in 14 cases. The mean prescription dose was 28 Gy (range 12–50 Gy), delivered with an average of eight isocenters (range two–18). The median peripheral isodose was 50% (range 30–70%). Patients were evaluated at 6 months, and at 1, 2, 3, 5, and 7 years after GKS. The median follow-up period was 30.5 months (range 12–79 months). Tumor stabilization after GKS was noted in 51 patients, tumor shrinkage in 25 patients, and enlargement in four patients requiring surgical removal in two cases. The 5-year actuarial progression-free survival was 92.8%. No new oculomotor deficit was observed. Among the 54 patients with oculomotor nerve deficits, 15 improved, eight recovered, and one worsened. Among the 13 patients with trigeminal neuralgia, one worsened (contemporary of tumor growing), five remained unchanged, four improved, and three recovered. In a patient with a remnant surrounding the optic nerve and preoperative low vision (3/10) the decision was to treat the lesion and deliberately sacrifice the residual visual acuity. Only one transient unexpected optic neuropathy has been observed. One case of delayed intracavernous carotid artery occlusion occurred 3 months after GKS, without permanent deficit. Another patient presented with partial complex seizures 18 months after GKS. All cases of tumor growth and neurological deficits observed after GKS occurred before the use of GammaPlan. Since the initiation of systematic use of stereotactic MR imaging and computer-assisted modern dose planning, no more side effects or cases of tumor growth have occurred. Conclusions. Gamma knife radiosurgery was found to be an effective low morbidity—related tool for the treatment of cavernous sinus meningioma. In a significant number of patients, oculomotor functional restoration was observed. The treatment appears to be an alternative to surgical removal of confined enclosed cavernous sinus meningioma and should be proposed as an adjuvant to surgery in case of extensive meningiomas.

Download Full-text