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Cogan B, Pearson RC, Paton CM, Jenkins NT, Cooper JA. Pecan-enriched diet improves cholesterol profiles and enhances postprandial microvascular reactivity in older adults. Nutr Res 2023; 111:44-58. [PMID: 36822079 DOI: 10.1016/j.nutres.2023.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 01/11/2023] [Accepted: 01/19/2023] [Indexed: 02/04/2023]
Abstract
Pecan-enriched diets have been linked to improved lipid metabolism; however, the impact of pecans on vascular health has yet to be examined. We hypothesized that 4 weeks of a pecan-enriched diet would improve fasting and postprandial blood lipids and vascular function compared with a nut-free diet. In this randomized control study, 44 older adults (59 ± 6 years) consumed 68 g of pecans/d (pecan; n = 21) or avoided all nuts (control; n = 23) for 4 weeks. At pre- and post-diet visits, fasting and postprandial blood lipids, macrovascular (by flow-mediated dilation), and microvascular (tissue saturation index reactive hyperemia [RH] kinetics by continuous-wave near-infrared spectroscopy) function were assessed. From the pre- to post-diet visit, there were greater reductions in fasting total cholesterol (pecan: -14 ± 4.0 vs control: -0.2 ± 5.4 mg/dL; P = .04), low-density lipoprotein (LDL) cholesterol (pecan: -15 ± 3.7 vs control: +1.9 ± 4.4 mg/dL; P = .01), non-high-density lipoprotein cholesterol (pecan: -15 ± 3.6 vs control: -0.5 ± 4.8 mg/dL; P = .02), LDL particle number (pecan: -126 ± 51 vs control: +43 ± 42 nmol/L; P = .01), and LDL medium (pecan: -34 ± 13 vs control: +16 ± 11 nmol/L; P < .01), for pecan vs control. Further, postprandial triglyceride was suppressed for pecan (P = .01) compared with control (P = .78). Postprandial RH slope (P = .04) and RH time to half (P = .004) was different by group, driven by improvements in pecan vs control. However, fasting macro- and microvascular function was unaffected. Daily pecan consumption for 4 weeks improved fasting and postprandial blood lipids and microvascular reactivity in older adults. Because changes in microvascular function typically precipitate macrovascular changes, long-term pecan consumption may improve vascular health and reduce risk for cardiovascular events. This trial was registered at clinicaltrials.gov (NCT04385537).
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Affiliation(s)
- Betsy Cogan
- Department of Nutritional Sciences, University of Georgia, Athens, GA, USA
| | - Regis C Pearson
- Department of Kinesiology, University of Georgia, Athens, GA, USA
| | - Chad M Paton
- Department of Nutritional Sciences, University of Georgia, Athens, GA, USA; Department of Food Science and Technology, University of Georgia, Athens, GA, USA
| | - Nathan T Jenkins
- Department of Kinesiology, University of Georgia, Athens, GA, USA
| | - Jamie A Cooper
- Department of Nutritional Sciences, University of Georgia, Athens, GA, USA.
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2
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Ounjaijean S, Rattanatham R, Somsak V, Boonhoh W, Surinkaew S. Gymnema inodorum Leaf Extract Improves Cardiac Function in Experimental Mice Infected with Plasmodium Berghei. J Evid Based Integr Med 2023; 28:2515690X221150526. [PMID: 36617811 PMCID: PMC9834418 DOI: 10.1177/2515690x221150526] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Malaria-associated cardiac injury has been reported to be the primary cause of death due to severe malaria. The discovery of substances showing a protective effect on cardiac injury during malaria infection is urgently needed. Hence, the purpose of this study was to evaluate the efficacy of Gymnema inodorum leaf extract (GIE) on cardiac function in mice infected with Plasmodium berghei. ICR mice were treated with 1 × 107 infected red blood cells of P. berghei ANKA (PbANKA), administered orally with GIE in 100, 250 and 500 mg/kg body weight of mice. Creatine phosphokinase (CPK) and echocardiography were carried out. It was found that CPK and heart-weight to body-weight (HW/BW) ratios were significantly higher in untreated mice than the healthy control. Moreover, impaired cardiac function in the untreated group was observed as indicated by changes in echocardiography. Interestingly, GIE exerted a protective effect on cardiac injury induced by PbANKA infection. Our results demonstrated that the parasitemia percentage, CPK, HW/BW ratio, and echocardiography in GIE treated mice were improved. However, there was no significant difference between GIE dosages. Therefore, GIE possessed a cardio-protective effect during malaria infection in mice.
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Affiliation(s)
- Sakaewan Ounjaijean
- School of Health Science Research, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Rujikorn Rattanatham
- School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat, Thailand,Research Excellence Center for Innovation and Health Products, Walailak University, Nakhon Si Thammarat, Thailand
| | - Voravuth Somsak
- School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat, Thailand,Research Excellence Center for Innovation and Health Products, Walailak University, Nakhon Si Thammarat, Thailand
| | - Worakan Boonhoh
- Akkhraratchakumari Veterinary College, Walailak University, Nakhon Si Thammarat, Thailand
| | - Sirirat Surinkaew
- School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat, Thailand,Research Excellence Center for Innovation and Health Products, Walailak University, Nakhon Si Thammarat, Thailand,Sirirat Surinkaew, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand.
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Gomes ARQ, Cunha N, Varela ELP, Brígido HPC, Vale VV, Dolabela MF, de Carvalho EP, Percário S. Oxidative Stress in Malaria: Potential Benefits of Antioxidant Therapy. Int J Mol Sci 2022; 23:ijms23115949. [PMID: 35682626 PMCID: PMC9180384 DOI: 10.3390/ijms23115949] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 01/07/2023] Open
Abstract
Malaria is an infectious disease and a serious public health problem in the world, with 3.3 billion people in endemic areas in 100 countries and about 200 million new cases each year, resulting in almost 1 million deaths in 2018. Although studies look for strategies to eradicate malaria, it is necessary to know more about its pathophysiology to understand the underlying mechanisms involved, particularly the redox balance, to guarantee success in combating this disease. In this review, we addressed the involvement of oxidative stress in malaria and the potential benefits of antioxidant supplementation as an adjuvant antimalarial therapy.
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Affiliation(s)
- Antonio Rafael Quadros Gomes
- Post-Graduate Program in Pharmaceutica Innovation, Institute of Health Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (A.R.Q.G.); (H.P.C.B.); (V.V.V.); (M.F.D.)
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (N.C.); (E.L.P.V.); (E.P.d.C.)
| | - Natasha Cunha
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (N.C.); (E.L.P.V.); (E.P.d.C.)
| | - Everton Luiz Pompeu Varela
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (N.C.); (E.L.P.V.); (E.P.d.C.)
- Post-graduate Program in Biodiversity and Biotechnology (BIONORTE), Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
| | - Heliton Patrick Cordovil Brígido
- Post-Graduate Program in Pharmaceutica Innovation, Institute of Health Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (A.R.Q.G.); (H.P.C.B.); (V.V.V.); (M.F.D.)
| | - Valdicley Vieira Vale
- Post-Graduate Program in Pharmaceutica Innovation, Institute of Health Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (A.R.Q.G.); (H.P.C.B.); (V.V.V.); (M.F.D.)
| | - Maria Fâni Dolabela
- Post-Graduate Program in Pharmaceutica Innovation, Institute of Health Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (A.R.Q.G.); (H.P.C.B.); (V.V.V.); (M.F.D.)
- Post-graduate Program in Biodiversity and Biotechnology (BIONORTE), Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
| | - Eliete Pereira de Carvalho
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (N.C.); (E.L.P.V.); (E.P.d.C.)
- Post-graduate Program in Biodiversity and Biotechnology (BIONORTE), Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
| | - Sandro Percário
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (N.C.); (E.L.P.V.); (E.P.d.C.)
- Post-graduate Program in Biodiversity and Biotechnology (BIONORTE), Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
- Correspondence:
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4
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Albrecht-Schgoer K, Lackner P, Schmutzhard E, Baier G. Cerebral Malaria: Current Clinical and Immunological Aspects. Front Immunol 2022; 13:863568. [PMID: 35514965 PMCID: PMC9067128 DOI: 10.3389/fimmu.2022.863568] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/21/2022] [Indexed: 11/23/2022] Open
Abstract
This review focuses on current clinical and immunological aspects of cerebral malaria induced by Plasmodium falciparum infection. Albeit many issues concerning the inflammatory responses remain unresolved and need further investigations, current knowledge of the underlying molecular mechanisms is highlighted. Furthermore, and in the light of significant limitations in preventative diagnosis and treatment of cerebral malaria, this review mainly discusses our understanding of immune mechanisms in the light of the most recent research findings. Remarkably, the newly proposed CD8+ T cell-driven pathophysiological aspects within the central nervous system are summarized, giving first rational insights into encouraging studies with immune-modulating adjunctive therapies that protect from symptomatic cerebral participation of Plasmodium falciparum infection.
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Affiliation(s)
- Karin Albrecht-Schgoer
- Division of Translational Cell Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter Lackner
- Department of Neurology, Klinik Floridsdorf, Wien, Austria
| | - Erich Schmutzhard
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Gottfried Baier
- Division of Translational Cell Genetics, Medical University of Innsbruck, Innsbruck, Austria
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5
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Heme oxygenase-1, carbon monoxide, and malaria – The interplay of chemistry and biology. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Bush MA, Anstey NM, Yeo TW, Florence SM, Granger DL, Mwaikambo ED, Weinberg JB. Vascular Dysfunction in Malaria: Understanding the Role of the Endothelial Glycocalyx. Front Cell Dev Biol 2021; 9:751251. [PMID: 34858979 PMCID: PMC8631294 DOI: 10.3389/fcell.2021.751251] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/27/2021] [Indexed: 01/18/2023] Open
Abstract
Malaria caused by Plasmodium falciparum results in over 400,000 deaths annually, predominantly affecting African children. In addition, non-falciparum species including vivax and knowlesi cause significant morbidity and mortality. Vascular dysfunction is a key feature in malaria pathogenesis leading to impaired blood perfusion, vascular obstruction, and tissue hypoxia. Contributing factors include adhesion of infected RBC to endothelium, endothelial activation, and reduced nitric oxide formation. Endothelial glycocalyx (eGC) protects the vasculature by maintaining vessel integrity and regulating cellular adhesion and nitric oxide signaling pathways. Breakdown of eGC is known to occur in infectious diseases such as bacterial sepsis and dengue and is associated with adverse outcomes. Emerging studies using biochemical markers and in vivo imaging suggest that eGC breakdown occurs during Plasmodium infection and is associated with markers of malaria disease severity, endothelial activation, and vascular function. In this review, we describe characteristics of eGC breakdown in malaria and discuss how these relate to vascular dysfunction and adverse outcomes. Further understanding of this process may lead to adjunctive therapy to preserve or restore damaged eGC and reduce microvascular dysfunction and the morbidity/mortality of malaria.
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Affiliation(s)
- Margaret A Bush
- Duke University School of Nursing and Durham VA Medical Centers, Durham, NC, United States
| | - Nicholas M Anstey
- Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Tsin W Yeo
- Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,National Centre for Infectious Diseases, Tan Tock Seng Hospital, Singapore, Singapore
| | | | - Donald L Granger
- School of Medicine, University of Utah and Salt Lake City VA Medical Centers, Salt Lake City, UT, United States
| | | | - J Brice Weinberg
- Duke University School of Medicine and Durham VA Medical Centers, Durham, NC, United States
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Knowlesi malaria: Human risk factors, clinical spectrum, and pathophysiology. ADVANCES IN PARASITOLOGY 2021; 113:1-43. [PMID: 34620381 DOI: 10.1016/bs.apar.2021.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Plasmodium knowlesi is endemic across Southeast Asia, and is the commonest cause of zoonotic malaria. The spectrum of clinical disease from P. knowlesi infection ranges from asymptomatic infection, through to severe malaria and death. Over 90% of clinical disease occurs in adults, mostly living in forest edge areas undergoing intensive land use change. With a 24-h asexual life cycle in humans, high parasite counts are possible, but most clinical cases of knowlesi malaria are uncomplicated with low parasitaemia. In co-endemic areas, median parasitaemia in knowlesi malaria is lower than that seen in vivax and falciparum malaria, suggesting a lower fever threshold. Severe malaria occurs in 6-9% of symptomatic adults. Manifestations of severe malaria from P. knowlesi are similar to those seen with falciparum malaria, with the notable absence of coma. Age, parasitaemia, cardiovascular comorbidities and delayed diagnosis are risk factors for severe disease and death, which are only seen in adults. Thrombocytopenia is near-universal in adults, likely related to platelet-red cell binding and clearance. Mechanisms underlying the microvascular sludging seen in fatal disease in non-natural primate hosts and the microvascular accumulation of parasites in fatal human disease are not clear. Marked reductions in deformability of both infected and uninfected red blood cells are associated with disease severity in both humans and other non-natural primate hosts, likely contributing to impaired microvascular perfusion and organ dysfunction. Endothelial activation, endothelial dysfunction, glycocalyx degradation and haemolysis are also associated with, and likely contribute to, severe disease and organ dysfunction, particularly acute kidney injury.
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8
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Bush MA, Florence SM, Yeo TW, Kalingonji AR, Chen Y, Granger DL, Rubach MP, Anstey NM, Mwaikambo ED, Weinberg JB. Degradation of endothelial glycocalyx in Tanzanian children with falciparum malaria. FASEB J 2021; 35:e21805. [PMID: 34403544 DOI: 10.1096/fj.202100277rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 06/25/2021] [Accepted: 07/01/2021] [Indexed: 01/20/2023]
Abstract
A layer of glycocalyx covers the vascular endothelium serving important protective and homeostatic functions. The objective of this study was to determine if breakdown of the endothelial glycocalyx (eGC) occurs during malaria infection in children. Measures of eGC integrity, endothelial activation, and microvascular reactivity were prospectively evaluated in 146 children: 44 with moderately severe malaria (MSM), 42 with severe malaria (SM), and 60 healthy controls (HC). Biochemical measures of eGC integrity included plasma syndecan-1 and total urinary glycosaminoglycans (GAG). Side-stream dark field imaging was used to quantitatively assess integrity of eGC. Plasma angiopoietin-2 (Ang-2) was measured as a marker of endothelial activation and also as a possible mediator of eGC breakdown. Our results show that urinary GAG, syndecan-1, and Ang-2 were elevated in patients with MSM and SM compared with HC. Syndecan-1 and GAG levels correlated significantly with each other and with plasma Ang-2. The eGC breakdown products also inversely correlated significantly with hemoglobin and platelet count. In the MSM group, imaging results provided further evidence for eGC degradation. Although not correlated with markers of eGC degradation, vascular function (assessed by non-invasive near infrared spectroscopy [NIRS]) demonstrated reduced microvascular reactivity, particularly affecting the SM group. Our findings provide further evidence for breakdown of eGC in falciparum malaria that may contribute to endothelial activation and adhesion of parasitized red blood cells, with reduced nitric oxide formation, and vascular dysfunction.
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Affiliation(s)
- Margaret A Bush
- School of Medicine, Duke University and Durham VA Medical Centers, Durham, NC, USA
| | | | - Tsin W Yeo
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia.,Lee Kong Chian School of Medicine, Nanyang Technological University, Republic of Singapore.,National Centre for Infectious Diseases, Tan Tock Seng Hospital, Republic of Singapore
| | | | - Youwei Chen
- School of Medicine, Duke University and Durham VA Medical Centers, Durham, NC, USA
| | - Donald L Granger
- University of Utah and VA Medical Centers, Salt Lake City, UT, USA
| | - Matthew P Rubach
- School of Medicine, Duke University and Durham VA Medical Centers, Durham, NC, USA
| | - Nicholas M Anstey
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | | | - Joe Brice Weinberg
- School of Medicine, Duke University and Durham VA Medical Centers, Durham, NC, USA
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9
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Early Endothelial Activation Precedes Glycocalyx Degradation and Microvascular Dysfunction in Experimentally Induced Plasmodium falciparum and Plasmodium vivax Infection. Infect Immun 2020; 88:IAI.00895-19. [PMID: 32122938 DOI: 10.1128/iai.00895-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/25/2020] [Indexed: 12/13/2022] Open
Abstract
Endothelial activation and microvascular dysfunction are key pathogenic processes in severe malaria. We evaluated the early role of these processes in experimentally induced Plasmodium falciparum and P. vivax infection. Participants were enrolled in induced blood-stage malaria clinical trials. Plasma osteoprotegerin, angiopoietin-2, and von Willebrand Factor (vWF) levels were measured as biomarkers of endothelial activation. Microvascular function was assessed using peripheral arterial tonometry and near-infrared spectroscopy, and the endothelial glycocalyx was assessed by sublingual videomicroscopy and measurement of biomarkers of degradation. Forty-five healthy, malaria-naive participants were recruited from 5 studies. Osteoprotegerin and vWF levels increased in participants following inoculation with P. vivax (n = 16) or P. falciparum (n = 15), with the angiopoietin-2 level also increasing in participants following inoculation with P. falciparum For both species, the most pronounced increase was seen in osteoprotegerin. This was particularly marked in participants inoculated with P. vivax, where the osteoprotegerin level correlated with the levels of parasitemia and the malaria clinical score. There were no changes in measures of endothelial glycocalyx or microvascular function. Plasma biomarkers of endothelial activation increased in early P. falciparum and P. vivax infection and preceded changes in the endothelial glycocalyx or microvascular function. The more pronounced increase in osteoprotegerin suggests that this biomarker may play a role in disease pathogenesis.
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10
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Yeo TW, Bush PA, Chen Y, Young SP, Zhang H, Millington DS, Granger DL, Mwaikambo ED, Anstey NM, Weinberg JB. Glycocalyx breakdown is increased in African children with cerebral and uncomplicated falciparum malaria. FASEB J 2019; 33:14185-14193. [PMID: 31658834 DOI: 10.1096/fj.201901048rr] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cerebral malaria (CM) from Plasmodium falciparum infection is associated with endothelial dysfunction and parasite sequestration. The glycocalyx (GCX), a carbohydrate-rich layer lining the endothelium, is crucial in vascular homeostasis. To evaluate the role of its loss in the pathogenesis of pediatric CM, we measured GCX degradation in Tanzanian children with World Health Organization-defined CM (n = 55), uncomplicated malaria (UM; n = 20), and healthy controls (HCs; n = 25). Urine GCX breakdown products [glycosaminoglycans (GAGs)] were quantified using dimethylmethylene blue (DMMB) and liquid chromatography-tandem mass spectrometry assays. DMMB-GAG and mass spectrometry (MS)-GAG (g/mol creatinine) were increased in CM and UM compared with HCs (P < 0.001), with no differences in DMMB-GAG and MS-GAG between CM and UM children or between those with and without a fatal outcome. In CM survivors, urinary GCX DMMB-GAG normalized by d 3. After adjusting for disease severity, DMMB-GAG was significantly associated with parasitemia [partial correlation coefficient (Pcorr) = 0.34; P = 0.01] and plasma TNF (Pcorr = 0.26; P = 0.04) and inversely with plasma and urine NO oxidation products [Pcorr = -0.31 (P = 0.01) and Pcorr = -0.26 (P = 0.03), respectively]. GCX breakdown is increased in children with falciparum malaria, with similar elevations in CM and UM. Endothelial GCX degradation may impair endothelial NO production, exacerbate adhesion-molecule expression, exposure, and parasite sequestration, and contribute to malaria pathogenesis.-Yeo, T. W., Bush, P. A., Chen, Y., Young, S. P., Zhang, H., Millington, D. S., Granger, D. L., Mwaikambo, E. D., Anstey, N. M., Weinberg, J. B. Glycocalyx breakdown is increased in African children with cerebral and uncomplicated falciparum malaria.
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Affiliation(s)
- Tsin W Yeo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,National Centre for Infectious Diseases, Tan Tock Seng Hospital, Singapore.,Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Peggy A Bush
- Duke University-Veterans Affairs (VA) Medical Center, Durham, North Carolina, USA
| | - Youwei Chen
- Duke University-Veterans Affairs (VA) Medical Center, Durham, North Carolina, USA
| | - Sarah P Young
- Duke University-Veterans Affairs (VA) Medical Center, Durham, North Carolina, USA
| | - Haoyue Zhang
- Duke University-Veterans Affairs (VA) Medical Center, Durham, North Carolina, USA
| | - David S Millington
- Duke University-Veterans Affairs (VA) Medical Center, Durham, North Carolina, USA
| | - Donald L Granger
- University of Utah-Veterans Affairs (VA) Medical Center, Salt Lake City, Utah, USA
| | | | - Nicholas M Anstey
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - J Brice Weinberg
- Duke University-Veterans Affairs (VA) Medical Center, Durham, North Carolina, USA
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11
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L-arginine supplementation and thromboxane synthase inhibition increases cerebral blood flow in experimental cerebral malaria. Sci Rep 2019; 9:13621. [PMID: 31541129 PMCID: PMC6754365 DOI: 10.1038/s41598-019-49855-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 08/30/2019] [Indexed: 12/14/2022] Open
Abstract
Cerebral malaria pathogenesis involves vascular dysfunction with low nitric oxide (NO) bioavailability, vasoconstriction and impaired vasodilation, leading to ischemia, tissue hypoxia and ultimately death. Cerebral blood flow (CBF) involves NO and other pathways, including arachidonic acid (AA)-derived metabolites. Here we show that mice with experimental cerebral malaria (ECM) by P. berghei ANKA showed marked decreases in CBF (as assessed by laser speckle contrast imaging - LSCI) and that administration of L-arginine supplementation (50 mg/kg) and/or of the thromboxane synthase inhibitor Ozagrel (100 mg/kg) induced immediate increases in CBF. L-arginine in combination with artesunate (32 mg/kg) induced immediate reversal of brain ischemia in the short-term (1 hour), but the effect subsided after 3 and 6 hours. Neither L-arginine nor Ozagrel reversed blood brain barrier breakdown. Mice with ECM showed brain levels of selected AA-derived metabolites with a vasoconstrictor profile, with increased levels of 8-isoprostanes, 20-HETE and 14,15-DHET, whereas mice infected with a non-ECM-inducing strain of P. berghei (NK65) showed a vasodilator profile, with normal levels of 20-HETE and 14,15-DHET and increased levels of PGE2. L-arginine is capable of partially reversing cerebral ischemia and AA metabolites may play a role in the cerebrovascular dysfunction in ECM.
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12
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Maurizio PL, Fuseini H, Tegha G, Hosseinipour M, De Paris K. Signatures of divergent anti-malarial treatment responses in peripheral blood from adults and young children in Malawi. Malar J 2019; 18:205. [PMID: 31234875 PMCID: PMC6591936 DOI: 10.1186/s12936-019-2842-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 06/17/2019] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Heterogeneity in the immune response to parasite infection is mediated in part by differences in host genetics, gender, and age group. In infants and young children, ongoing immunological maturation often results in increased susceptibility to infection and variable responses to drug treatment, increasing the risk of complications. Even though significant age-associated effects on host cytokine responses to Plasmodium falciparum infection have been identified, age-associated effects on uncomplicated malaria infection and anti-malarial treatment remain poorly understood. METHODS In samples of whole blood from a cohort of naturally infected malaria-positive individuals with non-severe falciparum malaria in Malawi (n = 63 total; 34 infants and young children < 2 years old, 29 adults > 18 years old), blood cytokine levels and monocyte and dendritic cell frequencies were assessed at two timepoints: acute infection, and 4 weeks post anti-malarial treatment. The effects of age group, gender, and timepoint were modeled, and the role of these factors on infection and treatment outcomes was evaluated. RESULTS Regardless of treatment timepoint, in this population age was significantly associated with overall blood haemoglobin, which was higher in adults, and plasma nitric oxide metabolites, IL-10, and TNF levels, which were higher in young children. There was a significant effect of age on the haemoglobin treatment response, whereby after treatment, levels increased in young children and decreased in adults. Furthermore, there were significant age-associated effects on treatment response for overall parasite load, IFN-γ, and IL-12(p40), and these effects were gender-dependent. Significant age effects on the overall levels and treatment response of myeloid dendritic cell frequencies were observed. In addition, within each age group, results showed continuous age effects on gametocyte levels (Pfs16), TNF, and nitric oxide metabolites. CONCLUSIONS In a clinical study of young children and adults experiencing natural falciparum malaria infection and receiving anti-malarial treatment, age-associated signatures of infection and treatment responses in peripheral blood were identified. This study describes host markers that may indicate, and potentially contribute to, differential post-treatment outcomes for malaria in young children versus adults.
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Affiliation(s)
- Paul L Maurizio
- Department of Medicine, Section of Genetic Medicine, The University of Chicago, Chicago, IL, 60637, USA.
- Department of Genetics, University of North Carolina-Chapel Hill, Chapel Hill, NC, 27599, USA.
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina-Chapel Hill, Chapel Hill, NC, 27599, USA.
| | - Hubaida Fuseini
- Department of Pathology, Microbiology & Immunology, Vanderbilt University, Nashville, TN, USA
| | - Gerald Tegha
- Division of Infectious Diseases, Department of Medicine, University of North Carolina, 130 Mason Farm Rd, Bioinformatics Bldg, Chapel Hill, NC, 27599, USA
| | - Mina Hosseinipour
- Division of Infectious Diseases, Department of Medicine, University of North Carolina, 130 Mason Farm Rd, Bioinformatics Bldg, Chapel Hill, NC, 27599, USA
- University of North Carolina Project-Malawi, Lilongwe, Malawi
| | - Kristina De Paris
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, 27599, USA
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13
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Gramaglia I, Velez J, Chang YS, Caparros-Wanderley W, Combes V, Grau G, Stins MF, van der Heyde HC. Citrulline protects mice from experimental cerebral malaria by ameliorating hypoargininemia, urea cycle changes and vascular leak. PLoS One 2019; 14:e0213428. [PMID: 30849122 PMCID: PMC6407779 DOI: 10.1371/journal.pone.0213428] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 02/21/2019] [Indexed: 12/18/2022] Open
Abstract
Clinical and model studies indicate that low nitric oxide (NO) bioavailability due in part to profound hypoargininemia contributes to cerebral malaria (CM) pathogenesis. Protection against CM pathogenesis may be achieved by altering the diet before infection with Plasmodium falciparum infection (nutraceutical) or by administering adjunctive therapy that decreases CM mortality (adjunctive therapy). This hypothesis was tested by administering citrulline or arginine in experimental CM (eCM). We report that citrulline injected as prophylaxis immediately post infection (PI) protected virtually all mice by ameliorating (i) hypoargininemia, (ii) urea cycle impairment, and (iii) disruption of blood brain barrier. Citrulline prophylaxis inhibited plasma arginase activity. Parasitemia was similar in citrulline- and vehicle control-groups, indicating that protection from pathogenesis was not due to decreased parasitemia. Both citrulline and arginine administered from day 1 PI in the drinking water significantly protected mice from eCM. These observations collectively indicate that increasing dietary citrulline or arginine decreases eCM mortality. Citrulline injected ip on day 4 PI with quinine-injected ip on day 6 PI partially protected mice from eCM; citrulline plus scavenging of superoxide with pegylated superoxide dismutase and pegylated catalase protected all recipients from eCM. These findings indicate that ameliorating hypoargininemia with citrulline plus superoxide scavenging decreases eCM mortality.
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Affiliation(s)
- Irene Gramaglia
- La Jolla Infectious Disease Institute, San Diego, CA, United States of America
- * E-mail:
| | - Joyce Velez
- La Jolla Infectious Disease Institute, San Diego, CA, United States of America
| | | | | | - Valery Combes
- La Jolla Infectious Disease Institute, San Diego, CA, United States of America
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Georges Grau
- La Jolla Infectious Disease Institute, San Diego, CA, United States of America
- Vascular Immunology Unit, University of Sydney, Sydney, Australia
| | - Monique F. Stins
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States of America
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14
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Aung NM, Nyein PP, Htut TY, Htet ZW, Kyi TT, Anstey NM, Kyi MM, Hanson J. Antibiotic Therapy in Adults with Malaria (ANTHEM): High Rate of Clinically Significant Bacteremia in Hospitalized Adults Diagnosed with Falciparum Malaria. Am J Trop Med Hyg 2018; 99:688-696. [PMID: 30014826 DOI: 10.4269/ajtmh.18-0378] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
It has been believed that concomitant bacteremia is uncommon in adults hospitalized with falciparum malaria. Accordingly, the World Health Organization treatment guidelines presently only recommended additional antibacterial therapy in these patients if they have a clinical syndrome compatible with serious bacterial infection. Admission blood cultures were collected from 20 consecutive adults in Myanmar, hospitalized with a positive immunochromatographic test and blood film, suggesting a diagnosis of falciparum malaria; four (20%) had bacteremia with a clinically significant pathogen. These case series' data were pooled with a previously published multicenter study from Myanmar which had also collected blood cultures in adults hospitalized with a diagnosis of falciparum malaria. Among 87 patients in the two studies, 13 (15%) had clinically significant bacteremia on admission, with Gram-negative organisms in 10 (77%) and Staphylococcus aureus in the remaining three (23%). Bacteremic patients had more severe disease than non-bacteremic patients (median [interquartile range] respiratory coma acidosis malaria score 2 [1-4] versus 1 [1-2], P = 0.02) and were more likely to die (2/13 [15%] versus 1/74 [1%], P = 0.01). However, bacterial coinfection was suspected clinically in a minority of bacteremic patients (5/13 [38%] compared with 13/70 [19%] of non-bacteremic patients, P = 0.11). Concomitant bacteremia in adults diagnosed with falciparum malaria may be more common than previously believed and is difficult to identify clinically in resource-poor settings. Death is more common in these patients, suggesting that clinicians should have a lower threshold for commencing empirical antibacterial therapy in adults diagnosed with falciparum malaria in these locations than is presently recommended.
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Affiliation(s)
- Ne Myo Aung
- University of Medicine 2, Yangon, Myanmar.,Insein General Hospital, Yangon, Myanmar
| | | | | | | | - Tint Tint Kyi
- Department of Medical Care, Ministry of Health and Sports, Nay Pyi Taw, Myanmar
| | - Nicholas M Anstey
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Mar Mar Kyi
- University of Medicine 2, Yangon, Myanmar.,Insein General Hospital, Yangon, Myanmar
| | - Josh Hanson
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia.,Kirby Institute, University of New South Wales, Sydney, Australia.,University of Medicine 2, Yangon, Myanmar
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15
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Yacoub S, Lam PK, Huynh TT, Nguyen Ho HH, Dong Thi HT, Van NT, Lien LT, Ha QNT, Le DHT, Mongkolspaya J, Culshaw A, Yeo TW, Wertheim H, Simmons C, Screaton G, Wills B. Endothelial Nitric Oxide Pathways in the Pathophysiology of Dengue: A Prospective Observational Study. Clin Infect Dis 2017; 65:1453-1461. [PMID: 28673038 PMCID: PMC5850435 DOI: 10.1093/cid/cix567] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 06/20/2017] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Dengue can cause increased vascular permeability that may lead to hypovolemic shock. Endothelial dysfunction may underlie this; however, the association of endothelial nitric oxide (NO) pathways with disease severity is unknown. METHODS We performed a prospective observational study in 2 Vietnamese hospitals, assessing patients presenting early (<72 hours of fever) and patients hospitalized with warning signs or severe dengue. The reactive hyperemic index (RHI), which measures endothelium-dependent vasodilation and is a surrogate marker of endothelial function and NO bioavailability, was evaluated using peripheral artery tonometry (EndoPAT), and plasma levels of l-arginine, arginase-1, and asymmetric dimethylarginine were measured at serial time-points. The main outcome of interest was plasma leakage severity. RESULTS Three hundred fourteen patients were enrolled; median age of the participants was 21(interquartile range, 13-30) years. No difference was found in the endothelial parameters between dengue and other febrile illness. Considering dengue patients, the RHI was significantly lower for patients with severe plasma leakage compared to those with no leakage (1.46 vs 2.00; P < .001), over acute time-points, apparent already in the early febrile phase (1.29 vs 1.75; P = .012). RHI correlated negatively with arginase-1 and positively with l-arginine (P = .001). CONCLUSIONS Endothelial dysfunction/NO bioavailability is associated with worse plasma leakage, occurs early in dengue illness and correlates with hypoargininemia and high arginase-1 levels.
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Affiliation(s)
- Sophie Yacoub
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hanoi and Ho Chi Minh City, Vietnam
- Department of Medicine, Imperial College London, United Kingdom
| | - Phung Khanh Lam
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hanoi and Ho Chi Minh City, Vietnam
| | | | | | - Hoai Tam Dong Thi
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hanoi and Ho Chi Minh City, Vietnam
- Hospital for Tropical Diseases, Ho Chi Minh City, and
| | - Nguyen Thu Van
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hanoi and Ho Chi Minh City, Vietnam
| | - Le Thi Lien
- National Hospital for Tropical Diseases, Hanoi, Vietnam
| | - Quyen Nguyen Than Ha
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hanoi and Ho Chi Minh City, Vietnam
| | - Duyen Huynh Thi Le
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hanoi and Ho Chi Minh City, Vietnam
| | | | - Abigail Culshaw
- Department of Medicine, Imperial College London, United Kingdom
| | - Tsin Wen Yeo
- Menzies School of Health Research, Darwin, Australia
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Heiman Wertheim
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hanoi and Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, University of Oxford, United Kingdom; and
| | - Cameron Simmons
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hanoi and Ho Chi Minh City, Vietnam
- Department of Microbiology and Immunology, University of Melbourne, Australia
| | - Gavin Screaton
- Department of Medicine, Imperial College London, United Kingdom
| | - Bridget Wills
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hanoi and Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, University of Oxford, United Kingdom; and
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16
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S-Nitrosoglutathione Reductase Deficiency Confers Improved Survival and Neurological Outcome in Experimental Cerebral Malaria. Infect Immun 2017; 85:IAI.00371-17. [PMID: 28674030 DOI: 10.1128/iai.00371-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 06/26/2017] [Indexed: 11/20/2022] Open
Abstract
Artesunate remains the mainstay of treatment for cerebral malaria, but it is less effective in later stages of disease when the host inflammatory response and blood-brain barrier integrity dictate clinical outcomes. Nitric oxide (NO) is an important regulator of inflammation and microvascular integrity, and impaired NO bioactivity is associated with fatal outcomes in malaria. Endogenous NO bioactivity in mammals is largely mediated by S-nitrosothiols (SNOs). Based on these observations, we hypothesized that animals deficient in the SNO-metabolizing enzyme, S-nitrosoglutathione reductase (GSNOR), which exhibit enhanced S-nitrosylation, would have improved outcomes in a preclinical model of cerebral malaria. GSNOR knockout (KO) mice infected with Plasmodium berghei ANKA had significantly delayed mortality compared to WT animals (P < 0.0001), despite higher parasite burdens (P < 0.01), and displayed markedly enhanced survival versus the wild type (WT) when treated with the antimalarial drug artesunate (77% versus 38%; P < 0.001). Improved survival was associated with higher levels of protein-bound NO, decreased levels of CD4+ and CD8+ T cells in the brain, improved blood-brain barrier integrity, and improved coma scores, as well as higher levels of gamma interferon. GSNOR KO animals receiving WT bone marrow had significantly reduced survival following P. berghei ANKA infection compared to those receiving KO bone barrow (P < 0.001). Reciprocal transplants established that survival benefits of GSNOR deletion were attributable primarily to the T cell compartment. These data indicate a role for GSNOR in the host response to malaria infection and suggest that strategies to disrupt its activity will improve clinical outcomes by enhancing microvascular integrity and modulating T cell tissue tropism.
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17
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Yeo TW, Florence SM, Kalingonji AR, Chen Y, Granger DL, Anstey NM, Mwaikambo ED, Weinberg JB. Decreased Microvascular Function in Tanzanian Children With Severe and Uncomplicated Falciparum Malaria. Open Forum Infect Dis 2017; 4:ofx079. [PMID: 28852670 PMCID: PMC5569702 DOI: 10.1093/ofid/ofx079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/19/2017] [Indexed: 11/13/2022] Open
Abstract
Microvascular function and oxygen consumption affect oxygen homeostasis but have not been assessed in African children with malaria. Microvascular function in Tanzanian children with severe malaria (SM) or uncomplicated malaria were 39% and 72%, respectively, of controls (P < .001). Uncomplicated malaria (P = .04), not SM (P = .06), children had increased oxygen consumption compared with controls.
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Affiliation(s)
- Tsin W Yeo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,Communicable Disease Centre, Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, Singapore.,Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | | | | | - Youwei Chen
- Duke University and V.A. Medical Centers, Durham, North Carolina; and
| | | | - Nicholas M Anstey
- Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | | | - J Brice Weinberg
- Duke University and V.A. Medical Centers, Durham, North Carolina; and
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18
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Villaverde C, Namazzi R, Shabani E, Opoka RO, John CC. Clinical Comparison of Retinopathy-Positive and Retinopathy-Negative Cerebral Malaria. Am J Trop Med Hyg 2017; 96:1176-1184. [PMID: 28138045 DOI: 10.4269/ajtmh.16-0315] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
AbstractCerebral malaria (CM) is a severe and often lethal complication of falciparum malaria. A classic malaria retinopathy is seen in some (retinopathy-positive [RP]) children but not others (retinopathy-negative [RN]), and is associated with increased parasite sequestration. It is unclear whether RN CM is a severe nonmalarial illness with incidental parasitemia or a less severe form of the same malarial illness as RP CM. Understanding the clinical differences between RP and RN CM may help shed light on the pathophysiology of malarial retinopathy. We compared clinical history, physical examination, laboratory findings, and outcomes of RP (N = 167) and RN (N = 87) children admitted to Mulago Hospital, Kampala, Uganda. Compared with RN children, RP children presented with a longer history of illness, as well as physical examination and laboratory findings indicative of more severe disease and organ damage. The hospital course of RP children was complicated by longer coma duration and a greater transfusion burden than RN children. Mortality did not differ significantly between RP and RN children (14.4% versus 8.0%, P = 0.14). Further, severity of retinal hemorrhage correlated with the majority of variables that differed between RP and RN children. The data suggest that RP and RN CM may reflect the spectrum of illness in CM, and that RN CM could be an earlier, less severe form of disease.
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Affiliation(s)
- Chandler Villaverde
- The Warren Alpert Medical School, Brown University, Providence, Rhode Island
| | - Ruth Namazzi
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences, Kampala, Uganda
| | - Estela Shabani
- Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota.,Department of Pediatrics, Indiana University, Indianapolis, Indiana
| | - Robert O Opoka
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences, Kampala, Uganda
| | - Chandy C John
- Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota.,Department of Pediatrics, Indiana University, Indianapolis, Indiana
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19
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Malaria: Biology and Disease. Cell 2016; 167:610-624. [PMID: 27768886 DOI: 10.1016/j.cell.2016.07.055] [Citation(s) in RCA: 439] [Impact Index Per Article: 54.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/17/2016] [Accepted: 07/29/2016] [Indexed: 11/22/2022]
Abstract
Malaria has been a major global health problem of humans through history and is a leading cause of death and disease across many tropical and subtropical countries. Over the last fifteen years renewed efforts at control have reduced the prevalence of malaria by over half, raising the prospect that elimination and perhaps eradication may be a long-term possibility. Achievement of this goal requires the development of new tools including novel antimalarial drugs and more efficacious vaccines as well as an increased understanding of the disease and biology of the parasite. This has catalyzed a major effort resulting in development and regulatory approval of the first vaccine against malaria (RTS,S/AS01) as well as identification of novel drug targets and antimalarial compounds, some of which are in human clinical trials.
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20
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Fowkes FGR, Aboyans V, Fowkes FJI, McDermott MM, Sampson UKA, Criqui MH. Peripheral artery disease: epidemiology and global perspectives. Nat Rev Cardiol 2016; 14:156-170. [PMID: 27853158 DOI: 10.1038/nrcardio.2016.179] [Citation(s) in RCA: 406] [Impact Index Per Article: 50.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Global populations are undergoing a major epidemiological transition in which the burden of atherosclerotic cardiovascular diseases is shifting rapidly from high-income to low-income and middle-income countries (LMICs). Peripheral artery disease (PAD) is no exception, so that greater focus is now required on the prevention and management of this disease in less-advantaged countries. In this Review, we examine the epidemiology of PAD and, where feasible, take a global perspective. However, the dearth of publications in LMICs means an unavoidable over-reliance on studies in high-income countries. Research to date suggests that PAD might affect a greater proportion of women than men in LMICs. Although factors such as poverty, industrialization, and infection might conceivably influence the development of PAD in such settings, the ageing of the population and increase in traditional cardiovascular risk factors, such as smoking, diabetes mellitus, and hypertension, are likely to be the main driving forces.
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Affiliation(s)
- F Gerry R Fowkes
- Usher Institute of Population Health Sciences and Informatics, University of Edinburgh, Teviot Place, Edinburgh, EH8 9AG, UK
| | - Victor Aboyans
- Department of Cardiology, Dupuytren University Hospital, 2 Avenue Martin Luther King, 87000 Limoges, France
| | - Freya J I Fowkes
- Centre for Population Health, Burnet Institute, 85 Commercial Road, Melbourne, Victoria 3004, Australia
| | - Mary M McDermott
- Department of Medicine and Preventive Medicine, Northwestern University Feinberg School of Medicine, 675 North Saint Clair, Chicago, Illinois 60611, USA
| | - Uchechukwu K A Sampson
- Center for Translational Research and Implementation Science, National Heart, Lung and Blood Institute, National Institutes of Health, 6705 Rockledge Drive, Bethesda, Maryland 20824, USA
| | - Michael H Criqui
- Department of Family Medicine and Public Health, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
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21
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Severe malaria: what's new on the pathogenesis front? Int J Parasitol 2016; 47:145-152. [PMID: 27670365 DOI: 10.1016/j.ijpara.2016.08.002] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 08/09/2016] [Accepted: 08/15/2016] [Indexed: 12/25/2022]
Abstract
Plasmodium falciparum causes the most severe and fatal form of malaria in humans with over half a million deaths each year. Cerebral malaria, a complex neurological syndrome of severe falciparum malaria, is often fatal and represents a major public health burden. Despite vigorous efforts, the pathophysiology of cerebral malaria remains to be elucidated, thereby hindering the development of adjunctive therapies. In recent years, multidisciplinary and collaborative approaches have led to groundbreaking progress both in the laboratory and in the field. Here we review the latest breakthroughs in severe malaria pathogenesis, with a specific focus on new pathogenetic mechanisms leading to cerebral malaria. The most recent findings point towards specific parasite phenotypes targeting brain microvasculature, endothelial dysfunction and subsequent oedema-induced brain swelling.
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22
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Barber BE, William T, Grigg MJ, Piera KA, Chen Y, Wang H, Weinberg JB, Yeo TW, Anstey NM. Nitric Oxide-Dependent Endothelial Dysfunction and Reduced Arginine Bioavailability in Plasmodium vivax Malaria but No Greater Increase in Intravascular Hemolysis in Severe Disease. J Infect Dis 2016; 214:1557-1564. [PMID: 27630198 DOI: 10.1093/infdis/jiw427] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/06/2016] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Pathogenesis of severe Plasmodium vivax malaria is poorly understood. Endothelial dysfunction and reduced nitric oxide (NO) bioavailability characterize severe falciparum malaria, but have not been assessed in severe vivax malaria. METHODS In patients with severe vivax malaria (n = 9), patients with nonsevere vivax malaria (n = 58), and healthy controls (n = 79), we measured NO-dependent endothelial function by using reactive hyperemia-peripheral arterial tonometry (RH-PAT) and assessed associations with arginine, asymmetric dimethylarginine (ADMA), and hemolysis. RESULTS The L-arginine level and the L-arginine to ADMA ratio (a measure of L-arginine bioavailability) were reduced in patients with severe vivax malaria and those with nonsevere vivax malaria, compared with healthy controls (median L-arginine level, 65, 66, and 98 µmol/mL, respectively [P = .0001]; median L-arginine to ADMA ratio, 115, 125, and 187, respectively [P = .0001]). Endothelial function was impaired in proportion to disease severity (median RH-PAT index, 1.49, 1.73, and 1.97 in patients with severe vivax malaria, those with nonsevere vivax malaria, and healthy controls, respectively; P = .018) and was associated with the L-arginine to ADMA ratio. While the posttreatment fall in hemoglobin level was greater in severe vivax malaria as compared to nonsevere vivax malaria (2.5 vs 1 g/dL; P = .0001), markers of intravascular hemolysis were not higher in severe disease. CONCLUSIONS Endothelial function is impaired in nonsevere and severe vivax malaria, is associated with reduced L-arginine bioavailability, and may contribute to microvascular pathogenesis. Severe disease appears to be more associated with extravascular hemolysis than with intravascular hemolysis.
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Affiliation(s)
- Bridget E Barber
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University.,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit.,Jesselton Medical Center, Kota Kinabalu, Malaysia
| | - Matthew J Grigg
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University.,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit
| | - Kim A Piera
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University
| | - Youwei Chen
- Duke University Medical Center.,VA Medical Center, Durham, North Carolina
| | - Hao Wang
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University
| | - J Brice Weinberg
- Duke University Medical Center.,VA Medical Center, Durham, North Carolina
| | - Tsin W Yeo
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University.,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit.,Lee Kong Chian School of Medicine, Nanyang Technological University.,Institute of Infectious Disease and Epidemiology, Tan Tock Seng Hospital, Singapore
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University.,Department of Infectious Diseases, Royal Darwin Hospital, Darwin, Australia.,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit
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23
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Weinberg JB, Volkheimer AD, Rubach MP, Florence SM, Mukemba JP, Kalingonji AR, Langelier C, Chen Y, Bush M, Yeo TW, Granger DL, Anstey NM, Mwaikambo ED. Monocyte polarization in children with falciparum malaria: relationship to nitric oxide insufficiency and disease severity. Sci Rep 2016; 6:29151. [PMID: 27385484 PMCID: PMC4935839 DOI: 10.1038/srep29151] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 06/15/2016] [Indexed: 12/23/2022] Open
Abstract
We earlier established that nitric oxide (NO) is protective against severe malaria and that arginine and NO levels are reduced in malaria patients. We now show that an M2-like blood monocyte phenotype is significantly associated with hypoargininemia, NO insufficiency, and disease severity in Tanzanian children with falciparum malaria. Compared to control children (n = 106), children with moderately severe (n = 77) and severe falciparum malaria (n = 129) had significantly higher mononuclear cell arginase 1 mRNA, protein, and enzyme activity; lower NOS2 mRNA; lower plasma arginine; and higher plasma IL-10, IL-13, and IL-4. In addition, monocyte CD206 and CD163 and plasma soluble CD163 were elevated. Multivariate logistic regression analysis revealed a significant correlation of risk of severe malaria with both plasma IL-10 and soluble CD163 levels. Monocyte M2 skewing likely contributes to NO bioinsufficiency in falciparum malaria in children. Treatments that reverse the M2 polarization may have potential as adjunctive treatment for malaria.
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Affiliation(s)
- J Brice Weinberg
- Duke University and V.A. Medical Centers, Durham, North Carolina, USA
| | | | - Matthew P Rubach
- Duke University and V.A. Medical Centers, Durham, North Carolina, USA
| | | | | | | | | | - Youwei Chen
- Duke University and V.A. Medical Centers, Durham, North Carolina, USA
| | - Margaret Bush
- Duke University and V.A. Medical Centers, Durham, North Carolina, USA
| | - Tsin W Yeo
- Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Donald L Granger
- University of Utah and V.A. Medical Centers, Salt Lake City, Utah, USA
| | - Nicholas M Anstey
- Menzies School of Health Research and Charles Darwin University, Darwin, Australia
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24
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Abstract
INTRODUCTION Antimalarial drugs are the primary weapon to treat parasite infection, save lives, and curtail further transmission. Accumulating data have indicated that at least some antimalarial drugs may contribute to severe neurological and/or psychiatric side effects which further complicates their use and limits the pool of available medications. AREAS COVERED In this review article, we summarize published scientific studies in search of evidence of the neuropsychiatric effects that may be attributed to the commonly used antimalarial drugs administered alone or in combination. Each individual drug was used as a search term in addition to keywords such as neuropsychiatric, adverse events, and neurotoxicity. EXPERT OPINION Accumulating data based on published reports over several decades have suggested that among the major commonly used antimalarial drugs, only mefloquine exhibited clear indications of serious neurological and/or psychiatric side effects. A more systematic approach to assess the neuropsychiatric adverse effects of new or repurposed antimalarial drugs on their safety, tolerability and efficacy phases of clinical studies and in post-marketing surveillance, is needed to ensure that these life-saving tools remain available and can be prescribed with appropriate caution and medical judgment.
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Affiliation(s)
- Bryan Grabias
- a Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases , Center for Biologics Evaluation and Research, Food and Drug Administration , Silver Spring , MD , USA
| | - Sanjai Kumar
- a Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases , Center for Biologics Evaluation and Research, Food and Drug Administration , Silver Spring , MD , USA
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25
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Alencar-Filho AC, Ferreira JMBB, Salinas JL, Fabbri C, Monteiro WM, Siqueira AM, Okoshi K, Lacerda MVG, Okoshi MP. Cardiovascular changes in patients with non-severe Plasmodium vivax malaria. IJC HEART & VASCULATURE 2016; 11:12-16. [PMID: 28616519 PMCID: PMC5441355 DOI: 10.1016/j.ijcha.2016.03.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/04/2016] [Indexed: 11/19/2022]
Abstract
Background Cardiovascular system involvement in patients with Plasmodium vivax malaria has been poorly addressed. The aim of this study was to evaluate cardiac structures and function, and serum markers of cardiovascular injury in patients with the non-severe form of vivax malaria in Manaus, Amazonas State, Brazil. Methods and results We prospectively evaluated 26 patients with vivax malaria in an outpatient referral hospital and compared results with a control group of 25 gender- and age-matched healthy individuals. Patients underwent clinical evaluation, laboratory tests, and transthoracic echocardiography at first evaluation (day zero, D0) and seven days (D7) after malaria diagnosis. At D0 echocardiography showed higher left ventricular (LV) systolic diameter (28.8 ± 2.82 vs 30.9 ± 4.03 mm; p = 0.037) and LV diastolic volume (82.4 ± 12.3 vs 93.8 ± 25.9 ml; p = 0.05), and lower LV ejection fraction (Teicholz method: 73.2 ± 6.59 vs 68.4 ± 4.87%; p = 0.004) in patients compared to controls. Right ventricle (RV) fractional area change (54.7 ± 5.11 vs 50.5 ± 6.71%; p = 0.014) was lower, and RV myocardial performance index (0.21 ± 0.07 vs 0.33 ± 0.19; p = 0.007), and pulmonary vascular resistance (1.13 ± 0.25 vs 1.32 ± 0.26 Woods unit; p = 0.012) were higher in patients than controls. Patients presented higher serum levels of unconjugated bilirubin (0.24 ± 0.15 vs 1.30 ± 0.89 mg/dL; p < 0.001), soluble vascular cell adhesion molecule–1 (sVCAM-1; 453 ± 143 vs 1983 ± 880 ng/mL; p < 0.001), N-terminal prohormone brain natriuretic peptide (0.59 ± 0.86 vs 1.08 ± 0.81 pg/mL; p = 0.045), and troponin T (861 ± 338 vs 1037 ± 264 pg/mL; p = 0.045), and lower levels of plasma nitrite (13.42 ± 8.15 vs 8.98 ± 3.97 μM; p = 0.016) than controls. Most alterations had reversed by D7. Conclusion Patients with non-severe Plasmodium vivax malaria present subclinical reversible cardiovascular changes.
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Affiliation(s)
| | | | | | - Camila Fabbri
- North University Center, Pharmacy School, Manaus, Brazil
| | - Wuelton Marcelo Monteiro
- Amazonas State University (UEA), Manaus, Brazil.,Tropical Disease Center "Dr. Heitor Vieira Dourado", Manaus, Brazil
| | - Andre Machado Siqueira
- National Institute of Infectology Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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d'Almeida TC, Sadissou I, Cottrell G, Tahar R, Moreau P, Favier B, Moutairou K, Donadi EA, Massougbodji A, Rouass-Freiss N, Courtin D, Garcia A. Evolution of the levels of human leukocyte antigen G (HLA-G) in Beninese infant during the first year of life in a malaria endemic area: using latent class analysis. Malar J 2016; 15:78. [PMID: 26862036 PMCID: PMC4746914 DOI: 10.1186/s12936-016-1131-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Accepted: 01/27/2016] [Indexed: 12/03/2022] Open
Abstract
Background HLA-G, a non-classical HLA class I antigen, is of crucial interest during pregnancy by inhibiting maternal immune response. Its role during infections is discussed, and it has been described that high levels of soluble HLA-G during childhood increase the risk of malaria. To explore more precisely interactions between soluble HLA-G and malaria, latent class analysis was used to test whether distinct sub-populations of children, each with distinctive soluble HLA-G evolutions may suggest the existence of groups presenting variable malaria susceptibility. Method A study was conducted in Benin from 2010 to 2013 and 165 children were followed from birth to 12 months. Evolution of soluble HLA-G was studied by the latent class method. Results Three groups of children were identified: one with consistently low levels of soluble HLA-G during follow-up, a second with very high levels and a last intermediate group. In all groups, low birth weight, high number of malaria infections and high exposure to malaria transmission were associated with high level of soluble HLA-G. Placental malaria was not. Presence of soluble HLA-G in cord blood increased the probability of belonging to the highest trajectory. Conclusion These results, together with previous ones, confirm the important role of HLA-G in the individual susceptibility to malaria. Assaying soluble HLA-G at birth could be a good indicator of newborns more fragile and at risk of infections during childhood.
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Affiliation(s)
- Tania C d'Almeida
- Université Pierre et Marie Curie, Paris, France. .,UMR216 MERIT "Mère et enfant face aux infections tropicales", Institut de Recherche pour le Développement, Paris, France.
| | - Ibrahim Sadissou
- UMR216 MERIT "Mère et enfant face aux infections tropicales", Institut de Recherche pour le Développement, Paris, France. .,Université Paris Descartes, Paris, France. .,Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance (CERPAGE), Cotonou, Benin. .,Université d'Abomey-Calavi, Cotonou, Benin.
| | - Gilles Cottrell
- UMR216 MERIT "Mère et enfant face aux infections tropicales", Institut de Recherche pour le Développement, Paris, France. .,Université Paris Descartes, Paris, France.
| | - Rachida Tahar
- UMR216 MERIT "Mère et enfant face aux infections tropicales", Institut de Recherche pour le Développement, Paris, France. .,Université Paris Descartes, Paris, France.
| | - Philippe Moreau
- UMR Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Université Paris Diderot - Paris 7, IMETI Service de Recherches en Hémato-Immunologie, Paris, France.
| | - Benoit Favier
- UMR Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Université Paris Diderot - Paris 7, IMETI Service de Recherches en Hémato-Immunologie, Paris, France.
| | | | - Eduardo A Donadi
- Division of Clinical Immunology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
| | - Achille Massougbodji
- Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance (CERPAGE), Cotonou, Benin. .,Université d'Abomey-Calavi, Cotonou, Benin.
| | - Nathalie Rouass-Freiss
- UMR Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Université Paris Diderot - Paris 7, IMETI Service de Recherches en Hémato-Immunologie, Paris, France.
| | - David Courtin
- UMR216 MERIT "Mère et enfant face aux infections tropicales", Institut de Recherche pour le Développement, Paris, France. .,Université Paris Descartes, Paris, France.
| | - André Garcia
- UMR216 MERIT "Mère et enfant face aux infections tropicales", Institut de Recherche pour le Développement, Paris, France. .,Université Paris Descartes, Paris, France.
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Barber BE, William T, Grigg MJ, Parameswaran U, Piera KA, Yeo TW, Anstey NM. Asymmetric Dimethylarginine in Adult Falciparum Malaria: Relationships With Disease Severity, Antimalarial Treatment, Hemolysis, and Inflammation. Open Forum Infect Dis 2016; 3:ofw027. [PMID: 26985445 PMCID: PMC4789539 DOI: 10.1093/ofid/ofw027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/05/2016] [Indexed: 12/04/2022] Open
Abstract
Asymmetric Dimethylarginine (ADMA) and arginine bioavailability are reduced acutely in adult falciparum malaria. ADMA increases following commencement of antimalarial therapy, is associated with arginine and haemolysis, and likely contributes to reduced nitric oxide bioavailability in severe falciparum malaria. Background. Endothelial nitric oxide (NO) bioavailability is impaired in severe falciparum malaria (SM). Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase (NOS), contributes to endothelial dysfunction and is associated with mortality in adults with falciparum malaria. However, factors associated with ADMA in malaria, including the NOS-substrate l-arginine, hemolysis, and antimalarial treatment, are not well understood. Methods. In a prospective observational study of Malaysian adults with SM (N = 22) and non-SM (NSM; N = 124) and healthy controls (HCs), we investigated factors associated with plasma ADMA including the effects of antimalarial treatment. Results. Compared with HCs, ADMA levels were lower in NSM (0.488 µM vs 0.540 µM, P = .001) and in the subset of SM patients enrolled before commencing treatment (0.453 µM [N = 5], P = .068), but levels were higher in SM patients enrolled after commencing antimalarial treatment (0.610 µM [N = 17], P = .026). In SM and NSM, ADMA levels increased significantly to above-baseline levels by day 3. Baseline ADMA was correlated with arginine and cell-free hemoglobin in SM and NSM and inversely correlated with interleukin-10 in NSM. Arginine and the arginine/ADMA ratio (reflective of arginine bioavailability) were lower in SM and NSM compared with HCs, and the arginine/ADMA ratio was lower in SM compared with NSM. Conclusions. Pretreatment ADMA concentrations and l-arginine bioavailability are reduced in SM and NSM. Asymmetric dimethylarginine increases to above-baseline levels after commencement of antimalarial treatment. Arginine, hemolysis, and posttreatment inflammation all likely contribute to ADMA regulation, with ADMA likely contributing to the reduced NO bioavailability in SM.
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Affiliation(s)
- Bridget E Barber
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia; Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit; Jesselton Medical Centre, Kota Kinabalu, Malaysia
| | - Matthew J Grigg
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia; Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit
| | - Uma Parameswaran
- Global and Tropical Health Division , Menzies School of Health Research and Charles Darwin University , Darwin , Australia
| | - Kim A Piera
- Global and Tropical Health Division , Menzies School of Health Research and Charles Darwin University , Darwin , Australia
| | - Tsin W Yeo
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia; Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; Institute of Infectious Disease and Epidemiology, Tan Tock Seng Hospital, Singapore
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia; Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit; Department of Infectious Diseases, Royal Darwin Hospital, Australia
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Deroost K, Pham TT, Opdenakker G, Van den Steen PE. The immunological balance between host and parasite in malaria. FEMS Microbiol Rev 2015; 40:208-57. [PMID: 26657789 DOI: 10.1093/femsre/fuv046] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2015] [Indexed: 12/16/2022] Open
Abstract
Coevolution of humans and malaria parasites has generated an intricate balance between the immune system of the host and virulence factors of the parasite, equilibrating maximal parasite transmission with limited host damage. Focusing on the blood stage of the disease, we discuss how the balance between anti-parasite immunity versus immunomodulatory and evasion mechanisms of the parasite may result in parasite clearance or chronic infection without major symptoms, whereas imbalances characterized by excessive parasite growth, exaggerated immune reactions or a combination of both cause severe pathology and death, which is detrimental for both parasite and host. A thorough understanding of the immunological balance of malaria and its relation to other physiological balances in the body is of crucial importance for developing effective interventions to reduce malaria-related morbidity and to diminish fatal outcomes due to severe complications. Therefore, we discuss in this review the detailed mechanisms of anti-malarial immunity, parasite virulence factors including immune evasion mechanisms and pathogenesis. Furthermore, we propose a comprehensive classification of malaria complications according to the different types of imbalances.
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Affiliation(s)
- Katrien Deroost
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium The Francis Crick Institute, Mill Hill Laboratory, London, NW71AA, UK
| | - Thao-Thy Pham
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
| | - Ghislain Opdenakker
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
| | - Philippe E Van den Steen
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
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Pharmacokinetic-Pharmacodynamic Model for the Effect of l-Arginine on Endothelial Function in Patients with Moderately Severe Falciparum Malaria. Antimicrob Agents Chemother 2015; 60:198-205. [PMID: 26482311 DOI: 10.1128/aac.01479-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 10/13/2015] [Indexed: 11/20/2022] Open
Abstract
Impaired organ perfusion in severe falciparum malaria arises from microvascular sequestration of parasitized cells and endothelial dysfunction. Endothelial dysfunction in malaria is secondary to impaired nitric oxide (NO) bioavailability, in part due to decreased plasma concentrations of l-arginine, the substrate for endothelial cell NO synthase. We quantified the time course of the effects of adjunctive l-arginine treatment on endothelial function in 73 patients with moderately severe falciparum malaria derived from previous studies. Three groups of 10 different patients received 3 g, 6 g, or 12 g of l-arginine as a half-hour infusion. The remaining 43 received saline placebo. A pharmacokinetic-pharmacodynamic (PKPD) model was developed to describe the time course of changes in exhaled NO concentrations and reactive hyperemia-peripheral arterial tonometry (RH-PAT) index values describing endothelial function and then used to explore optimal dosing regimens for l-arginine. A PK model describing arginine concentrations in patients with moderately severe malaria was extended with two pharmacodynamic biomeasures, the intermediary biochemical step (NO production) and endothelial function (RH-PAT index). A linear model described the relationship between arginine concentrations and exhaled NO. NO concentrations were linearly related to RH-PAT index. Simulations of dosing schedules using this PKPD model predicted that the time within therapeutic range would increase with increasing arginine dose. However, simulations demonstrated that regimens of continuous infusion over longer periods would prolong the time within the therapeutic range even more. The optimal dosing regimen for l-arginine is likely to be administration schedule dependent. Further studies are necessary to characterize the effects of such continuous infusions of l-arginine on NO and microvascular reactivity in severe malaria.
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30
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Endothelial-Leukocyte Interaction in Severe Malaria: Beyond the Brain. Mediators Inflamm 2015; 2015:168937. [PMID: 26491221 PMCID: PMC4605361 DOI: 10.1155/2015/168937] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/25/2015] [Accepted: 09/01/2015] [Indexed: 01/23/2023] Open
Abstract
Malaria is the most important parasitic disease worldwide, accounting for 1 million deaths each year. Severe malaria is a systemic illness characterized by dysfunction of brain tissue and of one or more peripheral organs as lungs and kidney. The most severe and most studied form of malaria is associated with cerebral complications due to capillary congestion and the adhesion of infected erythrocytes, platelets, and leukocytes to brain vasculature. Thus, leukocyte rolling and adhesion in the brain vascular bed during severe malaria is singular and distinct from other models of inflammation. The leukocyte/endothelium interaction and neutrophil accumulation are also observed in the lungs. However, lung interactions differ from brain interactions, likely due to differences in the blood-brain barrier and blood-air barrier tight junction composition of the brain and lung endothelium. Here, we review the importance of endothelial dysfunction and the mechanism of leukocyte/endothelium interaction during severe malaria. Furthermore, we hypothesize a possible use of adjunctive therapies to antimalarial drugs that target the interaction between the leukocytes and the endothelium.
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31
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Yeo TW, Anstey NM. Reply to Eisenhut. J Infect Dis 2015; 212:168. [PMID: 25712978 DOI: 10.1093/infdis/jiv085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 02/10/2015] [Indexed: 11/13/2022] Open
Affiliation(s)
- Tsin Wen Yeo
- Menzies School of Health Research and Charles Darwin University, Casuarina, Australia
| | - Nicholas M Anstey
- Menzies School of Health Research and Charles Darwin University, Casuarina, Australia
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32
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Eisenhut M. Etiology of Metabolic Changes in Severe Plasmodium falciparum Malaria. J Infect Dis 2015; 212:167-8. [PMID: 25712977 DOI: 10.1093/infdis/jiv084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 02/10/2015] [Indexed: 11/13/2022] Open
Affiliation(s)
- Michael Eisenhut
- Luton and Dunstable University Hospital NHS Foundation Trust, Luton, United Kingdom
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33
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Eisenhut M. Severe hemolysis as a potential contributing factor in the pathophysiology of cerebral malaria. Clin Infect Dis 2015; 60:1138. [PMID: 25527655 DOI: 10.1093/cid/ciu1149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Michael Eisenhut
- Luton and Dunstable University Hospital NHS Foundation Trust, Luton, United Kingdom
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34
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Yeo TW, Lampah DA, Kenangalem E, Tjitra E, Price RN, Weinberg JB, Hyland K, Granger DL, Anstey NM. Impaired systemic tetrahydrobiopterin bioavailability and increased dihydrobiopterin in adult falciparum malaria: association with disease severity, impaired microvascular function and increased endothelial activation. PLoS Pathog 2015; 11:e1004667. [PMID: 25764397 PMCID: PMC4357386 DOI: 10.1371/journal.ppat.1004667] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 01/07/2015] [Indexed: 12/22/2022] Open
Abstract
Tetrahydrobiopterin (BH₄) is a co-factor required for catalytic activity of nitric oxide synthase (NOS) and amino acid-monooxygenases, including phenylalanine hydroxylase. BH4 is unstable: during oxidative stress it is non-enzymatically oxidized to dihydrobiopterin (BH₂), which inhibits NOS. Depending on BH₄ availability, NOS oscillates between NO synthase and NADPH oxidase: as the BH₄/BH₂ ratio decreases, NO production falls and is replaced by superoxide. In African children and Asian adults with severe malaria, NO bioavailability decreases and plasma phenylalanine increases, together suggesting possible BH₄ deficiency. The primary three biopterin metabolites (BH₄, BH₂ and B₀ [biopterin]) and their association with disease severity have not been assessed in falciparum malaria. We measured pterin metabolites in urine of adults with severe falciparum malaria (SM; n=12), moderately-severe malaria (MSM, n=17), severe sepsis (SS; n=5) and healthy subjects (HC; n=20) as controls. In SM, urinary BH₄ was decreased (median 0.16 ¼mol/mmol creatinine) compared to MSM (median 0.27), SS (median 0.54), and HC (median 0.34)]; p<0.001. Conversely, BH₂ was increased in SM (median 0.91 ¼mol/mmol creatinine), compared to MSM (median 0.67), SS (median 0.39), and HC (median 0.52); p<0.001, suggesting increased oxidative stress and insufficient recycling of BH2 back to BH4 in severe malaria. Overall, the median BH₄/BH₂ ratio was lowest in SM [0.18 (IQR: 0.04-0.32)] compared to MSM (0.45, IQR 0.27-61), SS (1.03; IQR 0.54-2.38) and controls (0.66; IQR 0.43-1.07); p<0.001. In malaria, a lower BH₄/BH₂ ratio correlated with decreased microvascular reactivity (r=0.41; p=0.03) and increased ICAM-1 (r=-0.52; p=0.005). Decreased BH4 and increased BH₂ in severe malaria (but not in severe sepsis) uncouples NOS, leading to impaired NO bioavailability and potentially increased oxidative stress. Adjunctive therapy to regenerate BH4 may have a role in improving NO bioavailability and microvascular perfusion in severe falciparum malaria.
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Affiliation(s)
- Tsin W. Yeo
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
- Institute of Infectious Disease and Epidemiology, Tan Tock Seng Hospital, Singapore
| | - Daniel A. Lampah
- Menzies School of Health Research-National Institute of Health Research and Development Research Program, and District Ministry of Health, Timika, Papua, Indonesia
| | - Enny Kenangalem
- Menzies School of Health Research-National Institute of Health Research and Development Research Program, and District Ministry of Health, Timika, Papua, Indonesia
| | - Emiliana Tjitra
- National Institute of Health Research and Development, Jakarta, Indonesia
| | - Ric N. Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - J. Brice Weinberg
- Duke University and VA Medical Centers, Durham, North Carolina, United States of America
| | - Keith Hyland
- Medical Neurogenetics LLC, Atlanta, Georgia, United States of America
| | - Donald L. Granger
- Division of Infectious Diseases, University of Utah and Veterans Affairs Medical Center, Salt Lake City, Utah, United States of America
| | - Nicholas M. Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Division of Medicine, Royal Darwin Hospital, Darwin, Northern Territory, Australia
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