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1.
BMC Med ; 22(1): 170, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38649867

ABSTRACT

BACKGROUND: The stalling global progress in malaria control highlights the need for novel tools for malaria elimination, including transmission-blocking vaccines. Transmission-blocking vaccines aim to induce human antibodies that block parasite development in the mosquito and mosquitoes becoming infectious. The Pfs48/45 protein is a leading Plasmodium falciparum transmission-blocking vaccine candidate. The R0.6C fusion protein, consisting of Pfs48/45 domain 3 (6C) and the N-terminal region of P. falciparum glutamate-rich protein (R0), has previously been produced in Lactococcus lactis and elicited functional antibodies in rodents. Here, we assess the safety and transmission-reducing efficacy of R0.6C adsorbed to aluminium hydroxide with and without Matrix-M™ adjuvant in humans. METHODS: In this first-in-human, open-label clinical trial, malaria-naïve adults, aged 18-55 years, were recruited at the Radboudumc in Nijmegen, the Netherlands. Participants received four intramuscular vaccinations on days 0, 28, 56 and 168 with either 30 µg or 100 µg of R0.6C and were randomised for the allocation of one of the two different adjuvant combinations: aluminium hydroxide alone, or aluminium hydroxide combined with Matrix-M1™ adjuvant. Adverse events were recorded from inclusion until 84 days after the fourth vaccination. Anti-R0.6C and anti-6C IgG titres were measured by enzyme-linked immunosorbent assay. Transmission-reducing activity of participants' serum and purified vaccine-specific immunoglobulin G was assessed by standard membrane feeding assays using laboratory-reared Anopheles stephensi mosquitoes and cultured P. falciparum gametocytes. RESULTS: Thirty-one participants completed four vaccinations and were included in the analysis. Administration of all doses was safe and well-tolerated, with one related grade 3 adverse event (transient fever) and no serious adverse events occurring. Anti-R0.6C and anti-6C IgG titres were similar between the 30 and 100 µg R0.6C arms, but higher in Matrix-M1™ arms. Neat participant sera did not induce significant transmission-reducing activity in mosquito feeding experiments, but concentrated vaccine-specific IgGs purified from sera collected two weeks after the fourth vaccination achieved up to 99% transmission-reducing activity. CONCLUSIONS: R0.6C/aluminium hydroxide with or without Matrix-M1™ is safe, immunogenic and induces functional Pfs48/45-specific transmission-blocking antibodies, albeit at insufficient serum concentrations to result in transmission reduction by neat serum. Future work should focus on identifying alternative vaccine formulations or regimens that enhance functional antibody responses. TRIAL REGISTRATION: The trial is registered with ClinicalTrials.gov under identifier NCT04862416.


Subject(s)
Malaria Vaccines , Malaria, Falciparum , Membrane Glycoproteins , Plasmodium falciparum , Protozoan Proteins , Adolescent , Adult , Animals , Female , Humans , Male , Middle Aged , Young Adult , Adjuvants, Immunologic/administration & dosage , Aluminum Hydroxide/administration & dosage , Antibodies, Protozoan , Malaria Vaccines/immunology , Malaria Vaccines/administration & dosage , Malaria, Falciparum/prevention & control , Malaria, Falciparum/transmission , Malaria, Falciparum/immunology , Netherlands , Plasmodium falciparum/immunology , Protozoan Proteins/immunology
2.
Nature ; 604(7905): 280-286, 2022 04.
Article in English | MEDLINE | ID: mdl-35418631

ABSTRACT

Multijunction solar cells can overcome the fundamental efficiency limits of single-junction devices. The bandgap tunability of metal halide perovskite solar cells renders them attractive for multijunction architectures1. Combinations with silicon and copper indium gallium selenide (CIGS), as well as all-perovskite tandem cells, have been reported2-5. Meanwhile, narrow-gap non-fullerene acceptors have unlocked skyrocketing efficiencies for organic solar cells6,7. Organic and perovskite semiconductors are an attractive combination, sharing similar processing technologies. Currently, perovskite-organic tandems show subpar efficiencies and are limited by the low open-circuit voltage (Voc) of wide-gap perovskite cells8 and losses introduced by the interconnect between the subcells9,10. Here we demonstrate perovskite-organic tandem cells with an efficiency of 24.0 per cent (certified 23.1 per cent) and a high Voc of 2.15 volts. Optimized charge extraction layers afford perovskite subcells with an outstanding combination of high Voc and fill factor. The organic subcells provide a high external quantum efficiency in the near-infrared and, in contrast to paradigmatic concerns about limited photostability of non-fullerene cells11, show an outstanding operational stability if excitons are predominantly generated on the non-fullerene acceptor, which is the case in our tandems. The subcells are connected by an ultrathin (approximately 1.5 nanometres) metal-like indium oxide layer with unprecedented low optical/electrical losses. This work sets a milestone for perovskite-organic tandems, which outperform the best p-i-n perovskite single junctions12 and are on a par with perovskite-CIGS and all-perovskite multijunctions13.


Subject(s)
Calcium Compounds , Indium , Copper , Oxides , Titanium
3.
Parasit Vectors ; 10(1): 395, 2017 Aug 23.
Article in English | MEDLINE | ID: mdl-28835262

ABSTRACT

BACKGROUND: Plasmodium falciparum genetic diversity and multiplicity of infection (MOI) are parasite features that have been suggested to influence the acquisition of protective immunity against malaria. This study sought to assess the relationship between MOI and parasite density (PD) in malaria patients living in the Central Region of Ghana and to determine whether naturally occurring antibody levels against P. falciparum GLURP (PF3D7_1035300) and MSP3 (PF3D7_1035400) antigens are associated with decreased parasite load. METHODS: Dried filter paper blood blots were obtained from children and adults diagnosed with uncomplicated P. falciparum malaria. Microscopy was used to estimate P. falciparum parasite density and polymerase chain reaction (PCR) amplification of the polymorphic regions of msp1 (PF3D7_0930300) and msp2 (PF3D7_0206800) was used for parasite genotyping and MOI determination. ELISA was used to measure the serum IgG concentration of R0 fragment of GLURP (GLURP(R0)) and MSP3 antibodies. RESULTS: All 115 samples were positive for P. falciparum by PCR using either the msp1 or msp2 genotyping primer sets. The most prevalent msp1 and msp2 alleles were KI and 3D7, respectively. The geometric mean (GM) for MOI determined by both msp1 and msp2 genotyping was 1.3 for the entire population and was generally higher in children than in adults. Seropositivity was estimated at 67 and 63% for GLURP(R0) and MSP3 antibodies, respectively, and antibody titers were negatively correlated with parasite density. CONCLUSIONS: The negative correlation between naturally occurring GLURP(R0) and MSP3 antibody levels and parasite density observed in this study suggest that augmenting the antibody response with the GMZ2 vaccine could enhance protection in the Central Region of Ghana.


Subject(s)
Antigens, Protozoan/immunology , Malaria, Falciparum/immunology , Malaria, Falciparum/parasitology , Parasite Load , Plasmodium falciparum/immunology , Plasmodium falciparum/physiology , Protozoan Proteins/immunology , Adolescent , Adult , Animals , Antigens, Protozoan/genetics , Child , Child, Preschool , Dried Blood Spot Testing , Enzyme-Linked Immunosorbent Assay , Female , Genetic Variation , Genotype , Ghana/epidemiology , Humans , Immunoglobulin G/blood , Infant , Malaria Vaccines/immunology , Malaria, Falciparum/epidemiology , Male , Merozoite Surface Protein 1/genetics , Plasmodium falciparum/genetics , Polymerase Chain Reaction , Protozoan Proteins/genetics , Young Adult
4.
Arch Dermatol Res ; 306(10): 903-14, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25362540

ABSTRACT

Annexin A1 deregulation is often associated with cancer. Indeed we have shown that annexin A1 is overexpressed in melanoma and promotes metastases by formyl peptide receptor stimulation and MMP2 expression. Here, we demonstrated in different melanoma cell lines that annexin A1-MMP2 induction is mediated by MAPK and STAT3 pathways. To decipher endogenous annexin A1 action mode, we showed that annexin A1 is externalized in A375 cells and cleaved by a membrane-associated serine protease, allowing the release of a pro-invasive annexin A1 peptide in the extra cellular environment. Finally, a biochemical and proteomic approach allowed to enrich eight out of 12 members of the annexin family and to identify an original annexin A1 cleavage site localized between Ser(28) and Lys(29). Altogether, these data identify signaling pathways involved in annexin A1 pro-invasive role and suggest that externalized full-length annexin A1 interacts with formyl peptide receptors in a juxtacrine manner while ANXA 2-28 release allows autocrine and paracrine interaction.


Subject(s)
Annexin A1/metabolism , Melanoma/metabolism , Peptide Fragments/metabolism , Skin Neoplasms/metabolism , Animals , Autocrine Communication , Cell Line, Tumor , Cell Membrane/enzymology , Humans , Male , Matrix Metalloproteinase 2/metabolism , Melanoma/enzymology , Melanoma/pathology , Mice, Nude , Mitogen-Activated Protein Kinases/metabolism , Neoplasm Invasiveness , Paracrine Communication , Protein Structure, Tertiary , Receptors, Formyl Peptide/metabolism , STAT3 Transcription Factor/metabolism , Serine Proteases/metabolism , Signal Transduction , Skin Neoplasms/enzymology , Skin Neoplasms/pathology
5.
Scand J Immunol ; 75(6): 606-13, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22268665

ABSTRACT

FcγRIIa is known to be polymorphic; and certain variants are associated with different susceptibilities to malaria. Studies involving the Fulani ethnic group reported an ethnic difference in FcγRIIa-R131H genotype frequencies between the Fulani and other sympatric groups. No previous studies have addressed these questions in Burkina Faso. This study aimed to assess the influence of FcγRIIa-R131H polymorphism on anti-falciparum malaria IgG and IgG subclass responses in the Fulani and the Mossi ethnic groups living in Burkina Faso. Healthy adults more than 20 years old belonging to the Mossi or the Fulani ethnic groups were enrolled for the assessment of selected parasitological, immunological and genetic variables in relation to their susceptibility to malaria. The prevalence of the Plasmodium falciparum infection frequency was relatively low in the Fulani ethnic group compared to the Mossi ethnic group. For all tested antigens, the Fulani had higher antibody levels than the Mossi group. In both ethnic groups, a similar distribution of FcγRIIa R131H polymorphism was found. Individuals with the R allele of FcγRIIa had higher antibody levels than those with the H allele. This study confirmed that malaria infection affected less the Fulani group than the Mossi group. FcγRIIa-R131H allele distribution is similar in both ethnic groups, and higher antibody levels are associated with the FcγRIIa R allele compared to the H allele.


Subject(s)
Genetic Predisposition to Disease/genetics , Immunoglobulin G/immunology , Malaria, Falciparum/ethnology , Malaria, Falciparum/genetics , Polymorphism, Single Nucleotide , Receptors, IgG/genetics , Adult , Burkina Faso , Enzyme-Linked Immunosorbent Assay , Female , Genotype , Humans , Immunoglobulin G/genetics , Malaria, Falciparum/immunology , Male , Polymerase Chain Reaction , Polymorphism, Single Nucleotide/genetics
6.
Phys Chem Chem Phys ; 13(42): 18781-8, 2011 Nov 14.
Article in English | MEDLINE | ID: mdl-21789302

ABSTRACT

The preparation of an artificial superatom consisting of a positive charge inside a superfluid helium nanodroplet and an electron in an orbital surrounding the droplet is of fundamental interest and represents an experimental challenge. In this work, nanodroplets of several thousand helium atoms are doped with single caesium (Cs) atoms. While on the droplet, the Cs valence electron is excited in two steps through an intermediate state into nS, nP, and nD states. The excitation is monitored by laser induced fluorescence or, for high principal quantum numbers, by resonant three-photon-ionization. On-droplet Rydberg excitations are resolved up to about n = 20. The energies are compared with those of free Cs atom Rydberg states and quantum defects as well as the on-droplet ionization threshold are derived.

7.
Lab Anim ; 43(1): 96-101, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19015175

ABSTRACT

The aim of this study was to find the fastest, easiest and safest method of achieving orotracheal intubation for general anaesthesia in laboratory pigs. Twenty-one Yorkshire x Landrace crossbreed male castrated pigs (32.9 +/- 4.8 kg) were investigated. Dorsal and ventral recumbency are the alternatives most frequently described for animal positioning during intubation procedures. Based on standardized induction of general anaesthesia using pentobarbital and remifentanil, the dorsoventral and ventrodorsal positions were compared with regard to the time needed, changes in oxygenation and circulatory response. Positioning was found to be crucial for fast orotracheal intubation. The time required for safe intubation is significantly shorter with the ventrodorsal position (17.3 s) in comparison with the dorsoventral position (58.4 s; P < 0.001). Hypoxia did not occur in either group. A significant drop in systolic blood pressure was observed in both groups. Diastolic and mean arterial pressures were not influenced by intubation. A significant increase in heart rate was observed in pigs intubated in ventral recumbency, but not after intubation in the dorsal position. Preoxygenation before intubation is vitally important for preventing hypoxia. With regard to clinical practice, the haemodynamic changes observed in this investigation do not appear to be relevant, as the mean arterial pressure was not altered and heart rates only increased moderately. It may be concluded that the ventrodorsal position can be recommended for orotracheal intubation in pigs as the first choice for providing a smooth and fast airway.


Subject(s)
Anesthesia, Endotracheal/veterinary , Intubation, Intratracheal/veterinary , Laboratory Animal Science/methods , Swine/surgery , Anesthesia, Endotracheal/methods , Animals , Intubation, Intratracheal/methods , Laryngoscopy/methods , Laryngoscopy/veterinary , Time Factors
8.
Trop Med Int Health ; 13(2): 229-37, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18304269

ABSTRACT

OBJECTIVES: To examine whether the humoural response to malaria vaccine candidate antigens, Plasmodium falciparum [circumsporozoite repetitive sequence (NANP)(5) GLURP fragments (R0 and R2) and MSP3] varies with the level of malaria transmission and to determine whether the antibodies (IgG) present at the beginning of the malaria transmission season protect against clinical malaria. METHODS: Cross-sectional surveys were conducted to measure antibody response before, at the peak and at the end of the transmission season in children aged 6 months to 10 years in two villages with different levels of malaria transmission. A cohort study was performed to estimate the incidence of clinical malaria. RESULTS: Antibodies to these antigens showed different seasonal patterns. IgG concentrations to any of the four antigens were higher in the village with high entomological inoculation rate. Multivariate analysis of combined data from the two villages indicated that children who were classified as responders to the selected antigens were at lower risk of clinical malaria than children classified as non-responders [(NANP)(5) (incidence rate ratio (IRR) = 0.65, 95% CI: 0.46-0.92; P = 0.016), R0 (IRR = 0.69, 95% CI: 0.48-0.97; P = 0.032), R2 (IRR = 0.73, 95% CI: 0.50-1.06; P = 0.09), MSP3 (IRR = 0.52, 95% CI: 0.32-0.85; P = 0.009)]. Fitting a model with all four antibody responses showed that MSP3 looked the best malaria vaccine candidate (IRR = 0.63; 95% CI: 0.38-1.05; P = 0.08). CONCLUSION: Antibody levels to the four antigens are affected by the intensity of malaria transmission and associated with protection against clinical malaria. It is worthwhile investing in the development of these antigens as potential malaria vaccine candidates.


Subject(s)
Antibodies, Protozoan/immunology , Antigens, Protozoan/immunology , Malaria Vaccines/immunology , Malaria, Falciparum/prevention & control , Malaria, Falciparum/transmission , Animals , Antibodies, Protozoan/blood , Burkina Faso , Child , Child, Preschool , Cross-Sectional Studies , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Infant , Malaria, Falciparum/immunology , Malaria, Falciparum/parasitology , Plasmodium falciparum/immunology , Protozoan Proteins/immunology , Seasons
9.
Parasite Immunol ; 26(6-7): 265-72, 2004.
Article in English | MEDLINE | ID: mdl-15541030

ABSTRACT

A longitudinal study was undertaken in Burkina Faso among 293 children aged 6 months to 9 years in order to determine the correlation between an antibody response to several individual malarial antigens and malarial infection. It was found that the presence of a positive antibody response at the beginning of the rainy season to three long synthetic peptides corresponding to Plasmodium falciparum Exp-1 101-162, MSP-3 154-249 and GLURP 801-920 but not to CSP 274-375 correlated with a statistically significant decrease in malarial infection during the ongoing transmission season. The simultaneous presence of an antibody response to more than one antigen is indicative of a lower frequency of malarial infection. This gives scientific credibility to the notion that a successful malaria vaccine should contain multiple antigens.


Subject(s)
Antibodies, Protozoan/blood , Antigens, Protozoan/immunology , Malaria, Falciparum/immunology , Oligopeptides/immunology , Plasmodium falciparum/immunology , Protozoan Proteins/immunology , Animals , Burkina Faso , Child , Child, Preschool , Cross-Sectional Studies , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin G/blood , Infant , Longitudinal Studies , Malaria, Falciparum/prevention & control , Male
10.
Scand J Immunol ; 59(4): 363-72, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15049780

ABSTRACT

The immunogenicity and protective efficacy of various antigen-adjuvant formulations derived either from the merozoite-surface protein-3 (MSP-3) or the glutamate-rich protein (GLURP) of Plasmodium falciparum were evaluated in Saimiri sciureus monkeys. These proteins were selected for immunogenicity studies based primarily on their capacity of inducing an antibody-dependent cellular inhibition effect on parasite growth. Some of the S. sciureus monkeys immunized with MSP-3(212-380)-AS02 or GLURP(27-500)-alum were able to fully or partially control parasitaemia upon an experimental P. falciparum [Falciparum Uganda Palo Alto (FUP-SP) strain] blood-stage infection, and this protection was related to the prechallenge antibody titres induced. The data are indicative that MSP-3 and GLURP can induce protective immunity against an experimental P. falciparum infection using adjuvants that are acceptable for human use and this should trigger further studies with those new antigens.


Subject(s)
Antibodies/blood , Antigens, Protozoan/pharmacology , Malaria Vaccines/pharmacology , Malaria, Falciparum/prevention & control , Plasmodium falciparum/immunology , Protozoan Proteins/pharmacology , Animals , Antibodies/immunology , Antigens, Protozoan/administration & dosage , Antigens, Protozoan/immunology , Fluorescent Antibody Technique , Immunologic Memory/drug effects , Immunologic Memory/immunology , Malaria Vaccines/administration & dosage , Malaria Vaccines/immunology , Peptides/administration & dosage , Peptides/immunology , Peptides/pharmacology , Protozoan Proteins/administration & dosage , Protozoan Proteins/immunology , Saimiri
11.
Acta Trop ; 88(1): 17-25, 2003 Sep.
Article in English | MEDLINE | ID: mdl-12943972

ABSTRACT

Insecticide treated materials (ITM) are considered a useful malaria control measure for endemic countries, but whether they also delay the acquisition of immunity to malaria remains unclear. This study investigates plasma antibody levels in 160 children aged 3-6 years from five villages protected by insecticide treated curtains (ITC) over 6 years and in 184 children of the same age group from five villages in the same area never covered by ITC. The antigens to which antibodies were investigated were: the Plasmodium falciparum circumsporozoite protein (CSP) repetitive sequence (NANP)5; the C-terminal domain of the P. falciparum exported protein 1 (Cter-PfExp1); three fragments of the glutamate rich protein (GLURP), referred to as R0, R1 and R2; the merozoite surface protein 3 (MSP3). The level of antibodies was lower in children from the ITC area than in children from the non-ITC area for (NANP)5, R0, R2 and MSP3. Prevalence and intensity of P. falciparum infection were similar in the two groups of children. These findings suggest that reducing the level of malaria transmission over a long period may affect the level of antibodies in children to both sporozoite and blood stage malaria antigens.


Subject(s)
Antigens, Protozoan/blood , Malaria, Falciparum/immunology , Mosquito Control , Plasmodium falciparum/immunology , Animals , Antibody Formation , Burkina Faso/epidemiology , Child , Child, Preschool , Enzyme-Linked Immunosorbent Assay , Female , Humans , Malaria, Falciparum/epidemiology , Malaria, Falciparum/prevention & control , Male , Prevalence
12.
Intensive Care Med ; 29(6): 995-1002, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12739012

ABSTRACT

OBJECTIVE: To investigate the effects of combined selective inducible nitric oxide synthase (iNOS) inhibition using 1400 W with nicotinamide (NAD) as a PARS-inhibitor on hepato-splanchnic hemodynamics, O(2) kinetics, and energy metabolism during hyperdynamic porcine endotoxemia. DESIGN: Prospective, randomized, controlled, interventional experiment. SETTING: Animal research laboratory. SUBJECTS: Seventeen domestic pigs. INTERVENTIONS: After 12 h of continuous i.v. endotoxin (LPS) infusion 17 pigs received either no drug (CON, n=9) or 1400 W, titrated to maintain mean arterial pressure (MAP) at pre-endotoxin level, plus 10 mg.kg.h NAD ( n=8;). Measurements were obtained before, 12 h, 18 h, and 24 h after starting LPS infusion. MEASUREMENTS AND RESULTS: In addition to systemic and pulmonary hemodynamics and gas exchange, we measured hepatic arterial and portal venous blood flow, liver and portal venous drained viscera O(2) exchange, ileal mucosal-arterial PCO(2) gap, and portal as well as hepatic venous lactate/pyruvate ratios. Expired NO and plasma nitrate levels were assessed as a parameter of NO production. Without affecting cardiac output, therapy maintained MAP and blunted the LPS-induced rise in expired NO levels, attenuated the progressive fall in liver lactate clearance, and blunted the impairment of hepato-splanchnic redox state. The rise of ileal mucosal-arterial PCO(2) gap was not influenced. CONCLUSIONS: Combining selective iNOS inhibition with NAD as a PARS blocker may prevent circulatory failure and attenuate the detrimental consequences of LPS in intestinal and hepatocellular energy metabolism. Given the potential hepatotoxicity of high-dose NAD treatment, more potent PARS blockers with higher selectivity might further enhance the benefit of this therapeutic approach.


Subject(s)
Amidines/therapeutic use , Benzylamines/therapeutic use , Disease Models, Animal , Endotoxemia/drug therapy , Niacinamide/therapeutic use , Nitric Oxide Synthase/antagonists & inhibitors , Poly(ADP-ribose) Polymerase Inhibitors , Amidines/pharmacology , Animals , Benzylamines/pharmacology , Drug Evaluation, Preclinical , Drug Therapy, Combination , Endotoxemia/immunology , Endotoxemia/metabolism , Endotoxemia/physiopathology , Energy Metabolism/drug effects , Female , Hemodynamics/drug effects , Intestinal Mucosa/drug effects , Lipopolysaccharides/adverse effects , Liver Circulation/drug effects , Male , Niacinamide/pharmacology , Prospective Studies , Pulmonary Circulation/drug effects , Random Allocation , Splanchnic Circulation/drug effects , Swine , Time Factors
13.
FEBS Lett ; 515(1-3): 114-8, 2002 Mar 27.
Article in English | MEDLINE | ID: mdl-11943205

ABSTRACT

Potential contamination of animal-derived collagen with pathogens has led to the demand for safe recombinant sources of this complex molecule. In continuation of our previous work [Ruggiero et al. (2000) FEBS Lett. 469, 132-136], here we show that it is possible to produce recombinant hydroxylated homotrimeric collagen in tobacco plants that are co-transformed with a human type I collagen and a chimeric proline-4-hydroxylase (P4H). This is to our knowledge the first time that transient expression in tobacco was used to improve the quality of a recombinant protein produced in plants through co-expression with an animal cell-derived modifying enzyme. We demonstrated the functionality of the new chimeric P4H and thus improved the thermal stability of recombinant collagen I from plants to 37 degrees C.


Subject(s)
Agrobacterium tumefaciens/metabolism , Collagen Type I/genetics , Collagen Type I/metabolism , Nicotiana/genetics , Nicotiana/metabolism , Amino Acids/analysis , Biological Assay , Chromatography, High Pressure Liquid , Circular Dichroism , Collagen Type I/isolation & purification , Electrophoresis, Polyacrylamide Gel , Gene Expression , Humans , Hydroxylation , Pepsin A/chemistry , Plants, Genetically Modified , Procollagen-Proline Dioxygenase/genetics , Procollagen-Proline Dioxygenase/metabolism , Protein Conformation , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Temperature , Nicotiana/chemistry , Transformation, Genetic
14.
Anal Biochem ; 299(1): 84-91, 2001 Dec 01.
Article in English | MEDLINE | ID: mdl-11726188

ABSTRACT

The orientation of an immobilized antigen is important for recognition by, e.g., an antibody. When noncovalent passive adsorption is used for immobilization, the number of ways that the antigen can attach to the surface is numerous and control of how the antigen orientates on the surface is limited. Covalent immobilization restricts the number of the ways that the antigen can be immobilized to the number of reactive groups on the antigen and, hence, the orientation of the immobilized antigen is more predictable. Peptide antigens were synthesized and purified with protection groups on the lysine and cysteine side chains. These peptides, which have only one good nucleophilic group (the N-terminal alpha-amino group), were immobilized covalently in microtiter plates supplied with tresyl groups on the surface and the protection groups were cleaved off in situ after immobilization. The controlled orientation of these peptides resulted in enhanced recognition by antibodies in general. An enzyme-linked immunosorbent assay for detection of antibodies against a peptide derived from outer surface protein C from Borrelia burgdorferi, found in Lyme borreliosis patients, was established using this strategy. Lyme borreliosis suspect patient sera showed up to a 10-fold increase in the signal when the orientation of the peptide antigen was controlled by the in situ deprotection strategy.


Subject(s)
Antigens, Protozoan , Antigens, Surface/immunology , Bacterial Outer Membrane Proteins/chemistry , Enzyme-Linked Immunosorbent Assay/methods , Immune Sera/immunology , Lyme Disease/diagnosis , Peptides/chemistry , Protozoan Proteins , Antibodies/immunology , Borrelia burgdorferi/chemistry , Borrelia burgdorferi/pathogenicity , Humans , Immunoassay/methods , Lyme Disease/microbiology , Peptides/immunology , Peptides/isolation & purification
15.
Shock ; 16(3): 203-10, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11531022

ABSTRACT

We have previously demonstrated that non-selective nitric oxide synthase (NOS) inhibition did not reverse the LPS-induced deterioration of hepato-splanchnic energy status in porcine endotoxic shock. Therefore, this study investigated the effect of selective inducible NOS (iNOS) inhibition using 1400 W on intestinal and liver perfusion, O2 kinetics, and energy metabolism during hyperdynamic porcine endotoxemia. Intravenous E. Coli LPS was continuously infused over 24 h concomitant with fluid resuscitation. After 12 h of endotoxemia, continuous intravenous infusion of 1400 W was started until the end of the experiment and was titrated to maintain mean blood pressure (MAP) at baseline levels. Twelve, 18, and 24 h after starting LPS, we measured hepatic arterial and portal venous blood flow, ileal mucosal-arterial PCO2 gap, portal as well as hepatic venous lactate/pyruvate ratios, and endogenous glucose production rate. Expired NO and plasma nitrate levels were assessed as a measure of NO production. 1400 W decreased LPS-induced increase in expired NO and allowed for the maintenance of MAP without modification of cardiac output. Despite unchanged regional macrocirculation, 1400 W prevented the progressive rise of ileal mucosal-arterial PCO2 gap, significantly improved the LPS-induced impairment of hepato-splanchnic redox state, and blunted the decline in liver lactate clearance. Increased glucose production rate was not influenced. Thus, the selective iNOS inhibition with 1400 W prevented circulatory failure and largely attenuated otherwise progressive LPS-induced deterioration of intestinal and hepatocellular energy metabolism.


Subject(s)
Digestive System/metabolism , Endotoxemia/metabolism , Liver/metabolism , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide Synthase/metabolism , Oxygen/metabolism , Amidines/pharmacology , Animals , Benzylamines/pharmacology , Digestive System/drug effects , Endotoxemia/drug therapy , Endotoxemia/physiopathology , Energy Metabolism/drug effects , Enzyme Inhibitors/pharmacology , Female , Hemodynamics , Intestinal Mucosa/metabolism , Intestines/drug effects , Liver/drug effects , Male , Nitric Oxide Synthase Type II , Perfusion , Swine
16.
J Biol Chem ; 276(47): 43693-8, 2001 Nov 23.
Article in English | MEDLINE | ID: mdl-11557756

ABSTRACT

Human unhydroxylated homotrimeric triple-helical collagen I produced in transgenic plants was used as an experimental model to provide insights into the role of hydroxyproline in molecular folding and fibril formation. By using chemically cross-linked molecules, we show here that the absence of hydroxyproline residues does not prevent correct folding of the recombinant collagen although it markedly slows down the propagation rate compared with bovine fully hydroxylated homotrimeric collagen I. Relatively slow cis-trans-isomerization in the absence of hydroxyproline likely represents the rate-limiting factor in the propagation of the unhydroxylated collagen helix. Because of the lack of hydroxylation, recombinant collagen molecules showed increased flexibility as well as a reduced melting temperature compared with native homotrimers and heterotrimers, whereas the distribution of charged amino acids was unchanged. However, unlike with bovine collagen I, the recombinant collagen did not self-assemble into banded fibrils in physiological ionic strength buffer at 20 degrees C. Striated fibrils were only obtained with low ionic strength buffer. We propose that, under physiological ionic strength conditions, the hydroxyl groups in the native molecule retain water more efficiently thus favoring correct fibril formation. The importance of hydroxyproline in collagen self-assembly suggested by others from the crystal structures of collagen model peptides is thus confirmed experimentally on the entire collagen molecule.


Subject(s)
Collagen Type I/metabolism , Hydroxyproline/physiology , Plants, Genetically Modified/genetics , Protein Folding , Animals , Cattle , Collagen Type I/biosynthesis , Collagen Type I/chemistry , Collagen Type I/genetics , Electrophoresis, Polyacrylamide Gel , Protein Conformation
17.
Infect Immun ; 69(9): 5223-9, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11500389

ABSTRACT

Antibodies against three long synthetic peptides (LSPs) derived from the glutamate-rich protein (GLURP) of Plasmodium falciparum were analyzed in three cohorts from Liberia, Ghana, and Senegal. Two overlapping LSPs, LR67 and LR68, are derived from the relatively conserved N-terminal nonrepeat region (R0), and the third, LR70, is derived from the R2 repeat region. A high prevalence of antibody responses to each LSP was observed in all three areas of endemic infection. Levels of cytophilic immunoglobulin G (IgG) antibodies against both GLURP regions were significantly correlated with protection from clinical P. falciparum malaria. Protected children from the Ghana cohort possessed predominantly IgG1 antibodies against the nonrepeat epitope and IgG3 antibodies against the repeat epitope. T-cell proliferation responses, studied in the cohort from Senegal, revealed that T-helper-cell epitopes were confined to the nonrepeat region. When used as immunogens, the LR67 and LR68 peptides elicited strong IgG responses in outbred mice and LR67 also induced antibodies in mice of different H-2 haplotypes, confirming the presence of T-helper-cell epitopes in these constructs. Mouse antipeptide antisera recognized parasite proteins as determined by immunofluorescence and immunoblotting. This indicates that synthetic peptides derived from relatively conserved epitopes of GLURP might serve as useful immunogens for vaccination against P. falciparum malaria.


Subject(s)
Malaria Vaccines , Malaria, Falciparum/prevention & control , Peptides/chemical synthesis , Peptides/immunology , Plasmodium falciparum/immunology , Protozoan Proteins/immunology , Adolescent , Adult , Animals , Antibodies, Protozoan/blood , Antigens, Protozoan/immunology , Child , Child, Preschool , Female , Humans , Malaria Vaccines/immunology , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Mice, Inbred DBA , Middle Aged , Peptides/chemistry , Protozoan Proteins/chemistry , Protozoan Proteins/genetics , T-Lymphocytes/immunology
18.
Shock ; 16(2): 130-6, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11508865

ABSTRACT

We investigated the effect of mercaptoethylguanidine (MEG, 3 mg kg(-1)h(-1)), a combined selective inducible nitric oxide synthase (iNOS) inhibitor, a peroxynitrite and oxygen free radical scavenger with cyclooxygenase-inhibitor properties on intestinal and hepatic perfusion, O2 exchange, and metabolism during long-term hyperdynamic porcine endotoxemia. MEG was started 12 h after onset of endotoxemia. At baseline and after 12, 18, and 24 h of endotoxemia, hepatic arterial and portal venous blood flow, ileal mucosal-arterial PCO2 gap, portal and hepatic venous lactate/pyruvate ratio, free glutathione (GSH), and 8-isoprostanes were measured. Expired NO and plasma nitrate levels were assessed as well. MEG blunted the endotoxin-induced increase in expired NO and prevented the progressive fall in blood pressure without affecting cardiac output. It attenuated both systemic and regional venous acidosis without influencing the impairment of hepatosplanchnic metabolism nor counteracting the increase in GSH levels. In our model MEG failed to beneficially affect variables of oxidative stress.


Subject(s)
Endotoxemia/physiopathology , Hemodynamics/physiology , Nitric Oxide Synthase/antagonists & inhibitors , Peroxynitrous Acid/antagonists & inhibitors , 6-Ketoprostaglandin F1 alpha/blood , Animals , Cardiac Output , Endotoxemia/blood , Escherichia coli , Female , Glutathione/blood , Hemoglobins/metabolism , Lipopolysaccharides/toxicity , Male , Nitric Oxide/analysis , Nitric Oxide Synthase Type II , Oxygen Consumption , Respiratory Mechanics , Swine , Thromboxane B2/blood , Vascular Resistance
19.
Occup Med (Lond) ; 51(4): 278-86, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11463873

ABSTRACT

Musculoskeletal disorders are the leading cause of disability among people between 18 and 64 years of age. Patients with musculoskeletal injuries of the upper extremities are usually evaluated and treated by an individual physician and therapist. However, for patients who have problems, especially after being treated by a hand surgeon and a certified hand therapist, there are few other management options. A multidisciplinary assessment program for patients with chronic upper limb pain has not been described in the literature. As part of The University of Michigan RERC (Rehabilitation Engineering Research Center), the UPPER Program (UPper extremity Protocol Evaluation in Rehabilitation) was developed to evaluate patients who have disabling upper limb musculoskeletal disorders. At the center of the program is a multidisciplinary team composed of a physiatrist (physical medicine and rehabilitation specialist), occupational therapist, physical therapist, exercise physiologist, vocational counselor and pain psychologist. The UPPER Program elements include a pre-evaluation questionnaire, individual team member assessments and a team meeting. It is followed by a patient appointment with the team physician to review the results and recommendations. The essential details of the program are presented in this article so it can be reproduced elsewhere.


Subject(s)
Arm Injuries/rehabilitation , Cumulative Trauma Disorders/rehabilitation , Patient Care Team/organization & administration , Adolescent , Adult , Clinical Protocols , Humans , Middle Aged
20.
Intensive Care Med ; 27(4): 757-66, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11398705

ABSTRACT

OBJECTIVE: To investigate whether an increased ileal-mucosal-arterial PCO2 gap (delta PCO2) during hyperdynamic porcine endotoxemia is associated with impaired villus microcirculation. DESIGN: Prospective, randomized, controlled, experimental study. SETTING: Animal research laboratory. ANIMALS: Twenty-two domestic pigs. INTERVENTIONS: After baseline measurements, anesthetized and ventilated pigs received continuous i.v. endotoxin (ETX, n = 12) for 24 h or placebo (SHAM, n = 10). MEASUREMENTS AND RESULTS: Before, as well as 12 and 24 h after, the start of endotoxin or saline portal venous blood flow (QPV, ultrasound flow probe) and lactate/pyruvate ratios (L/P), the ileal-mucosal-arterial delta PCO2 (fiberoptic sensor) and bowel-wall capillary hemoglobin O2 saturation (%Hb-O2-cap, remission spectrophotometry) were assessed together with intravital video records of the ileal-mucosal microcirculation (number of perfused/heterogeneously perfused/unperfused villi) using orthogonal polarization spectral imaging (CYTOSCAN A/R) via an ileostomy. At 12 and 24 h endotoxin infusion, about half of the evaluated villi were heterogeneously or unperfused which was paralleled by a progressive significant increase of the ileal-mucosal-arterial delta PCO2 and portal venous L/P ratios, whereas QPV as well as both the mean %Hb-O2-cap and the %Hb-O2-cap frequency distributions remained unchanged. By contrast, in the SHAM-group, mucosal microcirculation was well-preserved, and none of the other parameters were influenced. CONCLUSIONS: We conclude that an increased ileal-mucosal-arterial delta PCO2 during porcine endotoxemia is related to impaired villus microcirculation. A putative contribution of disturbed cellular oxygen utilization resulting from "cytopathic hypoxia" may also assume importance.


Subject(s)
Carbon Dioxide/blood , Endotoxemia/blood , Endotoxemia/physiopathology , Escherichia coli Infections/blood , Escherichia coli Infections/physiopathology , Ileum/blood supply , Ileum/physiopathology , Intestinal Mucosa/blood supply , Intestinal Mucosa/physiopathology , Mesenteric Arteries/physiopathology , Animals , Blood Gas Analysis , Disease Models, Animal , Female , Lactic Acid/blood , Male , Microcirculation/physiopathology , Microscopy, Polarization , Portal Vein/physiopathology , Prospective Studies , Pyruvic Acid/blood , Spectrophotometry , Swine
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