Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Sci Transl Med ; 16(736): eadh0673, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38416844

RESUMO

Severe acute malnutrition (SAM) is the most high-risk form of undernutrition, particularly when children require hospitalization for complications. Complicated SAM is a multisystem disease with high inpatient and postdischarge mortality, especially in children with comorbidities such as HIV; however, the underlying pathogenesis of complicated SAM is poorly understood. Targeted multiplex biomarker analysis in children hospitalized with SAM (n = 264) was conducted on plasma samples, and inflammatory markers were assessed on stool samples taken at recruitment, discharge, and 12 to 24 and 48 weeks after discharge from three hospitals in Zimbabwe and Zambia. Compared with adequately nourished controls (n = 173), we found that at baseline, complicated SAM was characterized by systemic, endothelial, and intestinal inflammation, which was exacerbated by HIV infection. This persisted over 48 weeks despite nutritional recovery and was associated with children's outcomes. Baseline plasma concentrations of vascular endothelial growth factor, glucagon-like peptide-2, and intestinal fatty acid-binding protein were independently associated with lower mortality or hospital readmission over the following 48 weeks. Following principal components analysis of baseline biomarkers, higher scores of a component representing growth factors was associated with greater weight-for-height z score recovery and lower mortality or hospital readmission over the 48 weeks. Conversely, components representing higher gut and systemic inflammation were associated with higher mortality or hospital readmission. These findings highlight the interplay between inflammation, which damages tissues, and growth factors, which mediate endothelial and epithelial regeneration, and support further studies investigating interventions to reduce inflammation and promote epithelial repair as an approach to reducing mortality and improving nutritional recovery.


Assuntos
Infecções por HIV , Desnutrição , Desnutrição Aguda Grave , Criança , Humanos , Lactente , Readmissão do Paciente , Alta do Paciente , Infecções por HIV/complicações , Assistência ao Convalescente , Fator A de Crescimento do Endotélio Vascular , Desnutrição Aguda Grave/complicações , Inflamação/complicações , Peptídeos e Proteínas de Sinalização Intercelular , Desnutrição/complicações
2.
Heliyon ; 6(7): e04534, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32760834

RESUMO

Cirrhosis commonly complicates portal hypertension worldwide but in Zambia hepatosplenic schistosomiasis (HSS) dominates as the cause of portal hypertension. We need easier and non-invasive ways to assess HSS. Transient elastography (TE), a measure of liver stiffness can diagnose liver cirrhosis. TE remains unexplored in HSS patients, who generally have normal liver parenchyma. We aimed to explore liver stiffness in HSS. This nested case control study was conducted at the University Teaching Hospital, Lusaka, Zambia between January 2015 and January 2016. We enrolled 48 adults with HSS and 22 healthy controls. We assessed liver stiffness using TE while plasma hyaluronan was used to assess liver fibrosis. Plasma tumor necrosis factor receptor 1 (TNFR1) and soluble cluster of differentiation 14 (sCD14) were used to assess inflammation. The median (interquartile range) liver stiffness was higher in patients, 9.5 kPa (7.8, 12.8) than in controls, 4.7 kPa (4.0, 5.4), P < 0.0001. We noted linear correlations of hyaluronan and TNFR1 with the liver stiffness, P = 0.0307 and P = 0.0003 respectively. HSS patients seem to have higher liver stiffness than healthy controls. TE may be useful in identifying fibrosis in HSS. The positive correlations of inflammatory markers with TE suggest that HSS has both periportal and parenchymal pathophysiology.

3.
Cancer Med ; 9(10): 3445-3454, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32207245

RESUMO

The human immunodeficiency virus (HIV) pandemic heavily affects sub-Saharan Africa. It is associated with persistently active Epstein-Barr virus (EBV) infection. To determine if this translates into increased frequency of EBV-associated gastric cancer (EBVaGC), we evaluated molecular profiles of gastric cancer (GC) in Zambia. Patients with GC or premalignant gastric lesions were enrolled in Lusaka, Zambia. We used patients without any of these lesions as a control group. Chromogenic in situ hybridization (CISH) on tumor tissue was used to identify EBVaGC. To identify the microsatellite unstable subtype, immunofluorescence staining for MutL homolog 1 (MLH1) was used. Exposure to EBV and HIV was assessed serologically. We enrolled 369 patients (median age 52 years [IQR 41-65]; 198 (54%) female). Of these, 72 (20%) had GC and 35 (9%) had gastric premalignant lesions (PL). CISH identified EBVaGC in 5/44 (11%) of those with adequate tissue, while MLH1 loss was identified in 29/45 (64%). Both GC and PL were associated with the highest titers of antibodies to Early antigen-diffuse (OR 2.5, 95% CI 1.0-6.1, P = .048 and OR 3.9, 95% CI 1.1-12.9, P = .03, respectively) at high concentrations. Human immunodeficiency virus infection was associated with a range of antibodies to EBV, but not with any cancer subtype. Despite the association of HIV with persistent EBV, the proportion of EBVaGC in Zambia is similar to populations with a low prevalence of HIV infection. The proportion of microsatellite unstable tumors may be higher than other populations.


Assuntos
Adenocarcinoma/genética , Adenocarcinoma/virologia , Infecções por Vírus Epstein-Barr/epidemiologia , Infecções por HIV/epidemiologia , Proteína 1 Homóloga a MutL/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/virologia , Adenocarcinoma/epidemiologia , Adenocarcinoma/patologia , Adulto , Doença Crônica , Endoscopia do Sistema Digestório , Feminino , Gastrite Atrófica/genética , Gastrite Atrófica/metabolismo , Gastrite Atrófica/patologia , Gastrite Atrófica/virologia , Humanos , Hibridização In Situ , Masculino , Metaplasia , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/patologia , Zâmbia/epidemiologia
4.
Am J Trop Med Hyg ; 102(4): 832-837, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32067625

RESUMO

Hepatosplenic schistosomiasis (HSS) complicates portal hypertension, leading to life-threatening variceal bleeding. Variceal bleeding is associated with increased portal vein diameter (PVD). Beta-blockers prevent variceal bleeding. It is unclear whether beta-blockers such as propranolol can reduce PVD in HSS. We aimed to explore the effect of propranolol on PVD in HSS. A longitudinal study was conducted at the University Teaching Hospital, Zambia, as an extension of a clinical trial of rifaximin undertaken to test the hypothesis that rifaximin could reduce bacterial translocation in HSS. We randomized 85 adults to either rifaximin and standard care, or propranolol-based standard care only for 42 days. We then followed up all the patients on propranolol up to day 180. We used ultrasound to measure PVD at baseline and day 180. The primary outcome was reduction in PVD. Beta-blockade and splenic size reduction were secondary outcomes. Portal vein diameter reduced after 180 days of propranolol therapy from median 12 mm (interquartile range (IQR): 11-14) to median 10 mm (IQR: 9-13) (P < 0.001). The pulse rate reduced from baseline median 70 beats/minute (IQR: 66-80) to 65 beats/minute (IQR: 60-70) by day 180 (P = 0.006). Hemoglobin levels improved from baseline median 8 g/dL (IQR: 6-11) to 12 g/dL (10-14) (P < 0.001). Splenic size remained unchanged. Propranolol led to the reduction in PVD over 180 days. This suggests that ultrasound could be useful in monitoring response and compliance to beta-blockers, especially in resource-constraint areas where portal hypertension measurement facilities are unavailable.


Assuntos
Hipertensão Portal/etiologia , Hepatopatias/tratamento farmacológico , Hepatopatias/parasitologia , Propranolol/uso terapêutico , Esquistossomose/complicações , Adulto , Anti-Helmínticos/uso terapêutico , Antibacterianos/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Feminino , Humanos , Hipertensão Portal/tratamento farmacológico , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Veia Porta , Praziquantel/uso terapêutico , Estudos Prospectivos , Rifaximina/uso terapêutico
5.
EBioMedicine ; 45: 456-463, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31229436

RESUMO

BACKGROUND: Children with severe acute malnutrition (SAM), with or without diarrhoea, often have enteropathy, but there are few molecular data to guide development of new therapies. We set out to determine whether SAM enteropathy is characterised by specific transcriptional changes which might improve understanding or help identify new treatments. METHODS: We collected intestinal biopsies from children with SAM and persistent diarrhoea. mRNA was extracted from biopsies, sequenced, and subjected to a progressive set of complementary analytical approaches: NOIseq, Gene Set Enrichment Analysis (GSEA), and correlation analysis of phenotypic data with gene expression. FINDINGS: Transcriptomic profiles were generated for biopsy sets from 27 children of both sexes, under 2 years of age, of whom one-third were HIV-infected. NOIseq analysis, constructed from phenotypic group extremes, revealed 66 differentially expressed genes (DEGs) out of 21,386 mapped to the reference genome. These DEGs include genes for mucins and mucus integrity, antimicrobial defence, nutrient absorption, C-X-C chemokines, proteases and anti-proteases. Phenotype - expression correlation analysis identified 1221 genes related to villus height, including increased cell cycling gene expression in more severe enteropathy. Amino acid transporters and ZIP zinc transporters were specifically increased in severe enteropathy, but transcripts for xenobiotic metabolising enzymes were reduced. INTERPRETATION: Transcriptomic analysis of this rare collection of intestinal biopsies identified multiple novel elements of pathology, including specific alterations in nutrient transporters. Changes in xenobiotic metabolism in the gut may alter drug disposition. Both NOIseq and GSEA identified gene clusters similar to those differentially expressed in pediatric Crohn's disease but to a much lesser degree than those identified in coeliac disease. FUND: Bill & Melinda Gates Foundation OPP1066118. The funding agency had no role in study design, data collection, data analysis, interpretation, or writing of the report.


Assuntos
Diarreia/genética , Enteropatias/genética , Desnutrição Aguda Grave/genética , Transcriptoma/genética , Biópsia , Criança , Pré-Escolar , Diarreia/epidemiologia , Diarreia/patologia , Feminino , Perfilação da Expressão Gênica , Humanos , Lactente , Enteropatias/epidemiologia , Enteropatias/patologia , Mucosa Intestinal/metabolismo , Masculino , Análise de Sequência de RNA , Desnutrição Aguda Grave/epidemiologia , Desnutrição Aguda Grave/patologia , Zâmbia/epidemiologia
6.
Am J Trop Med Hyg ; 98(4): 1152-1158, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29436337

RESUMO

Cirrhosis is the dominant cause of portal hypertension globally but may be overshadowed by hepatosplenic schistosomiasis (HSS) in the tropics. In Zambia, schistosomiasis seroprevalence can reach 88% in endemic areas. Bacterial translocation (BT) drives portal hypertension in cirrhosis contributing to mortality but remains unexplored in HSS. Rifaximin, a non-absorbable antibiotic may reduce BT. We aimed to explore the influence of rifaximin on BT, inflammation, and fibrosis in HSS. In this phase II open-label trial (ISRCTN67590499), 186 patients with HSS in Zambia were evaluated and 85 were randomized to standard care with or without rifaximin for 42 days. Changes in markers of inflammation, BT, and fibrosis were the primary outcomes. BT was measured using plasma 16S rRNA, lipopolysaccharide-binding protein, and lipopolysaccharide, whereas hyaluronan was used to measure fibrosis. Tumor necrosis factor receptor 1 (TNFR1) and soluble cluster of differentiation 14 (sCD14) assessed inflammation. 16S rRNA reduced from baseline (median 146 copies/µL, interquartile range [IQR] 9, 537) to day 42 in the rifaximin group (median 63 copies/µL, IQR 12, 196), P < 0.01. The rise in sCD14 was lower (P < 0.01) in the rifaximin group (median rise 122 ng/mL, IQR-184, 783) than in the non-rifaximin group (median rise 832 ng/mL, IQR 530, 967). TNFR1 decreased (P < 0.01) in the rifaximin group (median -39 ng/mL IQR-306, 563) but increased in the non-rifaximin group (median 166 ng/mL, IQR 3, 337). Other markers remained unaffected. Rifaximin led to a reduction of inflammatory markers and bacterial 16S rRNA which may implicate BT in the inflammation in HSS.


Assuntos
Antibacterianos/farmacologia , Translocação Bacteriana/efeitos dos fármacos , Inflamação/sangue , Hepatopatias Parasitárias/tratamento farmacológico , Rifaximina/farmacologia , Esquistossomose/tratamento farmacológico , Esplenopatias/tratamento farmacológico , Adulto , Biomarcadores/sangue , Feminino , Humanos , Receptores de Lipopolissacarídeos/sangue , Hepatopatias Parasitárias/sangue , Hepatopatias Parasitárias/microbiologia , Masculino , Pessoa de Meia-Idade , RNA Bacteriano/sangue , RNA Ribossômico 16S/sangue , Receptores Tipo I de Fatores de Necrose Tumoral/sangue , Rifaximina/uso terapêutico , Esquistossomose/sangue , Esquistossomose/microbiologia , Esplenopatias/sangue , Esplenopatias/microbiologia , Zâmbia
7.
Am J Trop Med Hyg ; 97(5): 1603-1610, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29140241

RESUMO

Microbial translocation is a poorly understood consequence of several disorders such as environmental enteropathy (EE) and hepatosplenic schistosomiasis (HSS). Herein, we compared biomarkers of microbial origin and immune activation in adults with these disorders and in healthy controls. A cross-sectional study was conducted in participants with EE recruited from Misisi compound, Lusaka, Zambia; HSS patients and healthy controls from the University Teaching Hospital, Lusaka. Plasma lipopolysaccharides (LPSs) was measured by limulus amoebocyte lysate assay, plasma 16S ribosomal RNA (16S rRNA) gene copy number was quantified by quantitative real-time polymerase chain reaction, Toll-like receptor ligand (TLRL) activity by QUANTI-Blue detection medium, and cytokines from cell culture supernatant by Cytometric Bead Array. In univariate analysis LPS, 16S rRNA gene copy number, and TLR activity were all high and correlated with each other and with cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-10, and IL-4 secreted by the RAW-Blue cells. After controlling for baseline characteristic, biomarkers of microbial translocation in blood were predictors of TNF-α, IL-6, and IL-10 activation in cell culture supernatant from EE participants and HSS patients but not in healthy controls. TLR activity showed the strongest correlation with TNF-α. These data provide correlative evidence that microbial translocation contributes to systemic cytokine activation in two disorders common in the tropics, with total TLR ligand estimation showing the strongest correlation with TNF-α (r = 0.66, P < 0.001).


Assuntos
Translocação Bacteriana , Biomarcadores/sangue , Enteropatias/epidemiologia , Esquistossomose/epidemiologia , Adulto , Animais , Estudos Transversais , Citocinas/sangue , DNA Bacteriano/sangue , Feminino , Dosagem de Genes , Interações Hospedeiro-Parasita , Humanos , Enteropatias/sangue , Enteropatias/imunologia , Lipopolissacarídeos/sangue , Lipoproteínas/sangue , Masculino , Camundongos , Pessoa de Meia-Idade , Células RAW 264.7 , RNA Ribossômico 16S/sangue , Reação em Cadeia da Polimerase em Tempo Real , Esquistossomose/sangue , Esquistossomose/imunologia , Ácidos Teicoicos/sangue , Adulto Jovem , Zâmbia/epidemiologia
8.
EBioMedicine ; 22: 191-199, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28750860

RESUMO

Intestinal damage in malnutrition constitutes a threat to the survival of many thousands of children globally. We studied children in Lusaka, Zambia, with severe acute malnutrition (SAM) and persistent diarrhea using endoscopy, biopsy and analysis of markers and protective proteins in blood and intestinal secretions. We carried out parallel investigations in apparently healthy adults, and analyzed biomarkers only in apparently healthy children. Villus height and crypt depth did not differ in children with SAM and adult controls, but epithelial surface was reduced in children with SAM (median 445, interquartile range (IQR) 388, 562µm per 100µm muscularis mucosae) compared to adults (578, IQR 465,709; P=0.004). Histological lesions and disruptions of claudin-4 and E-cadherin were most pronounced in children with SAM. Circulating lipopolysaccharide, a marker of bacterial translocation, was higher in malnourished children (251, IQR 110,460EU/ml) than in healthy children (51, IQR 0,111; P=0.0001). Other translocation markers showed similar patterns. Anti-Deamidated Gliadin Peptide IgG concentrations, although within the normal range, were higher in children with SAM (median 2.7U/ml, IQR 1.5-8.6) than in adults (1.6, 1.4-2.1; P=0.005), and were inversely correlated with villus height (ρ=-0.79, n=13, P=0.001). Malnutrition enteropathy is associated with intestinal barrier failure and immune dysregulation.


Assuntos
Autoanticorpos/metabolismo , Caderinas/metabolismo , Claudina-4/metabolismo , Diarreia/diagnóstico , Desnutrição Aguda Grave/diagnóstico , Antígenos CD , Biomarcadores/sangue , Biomarcadores/metabolismo , Biópsia , Criança , Pré-Escolar , Estudos Transversais , Diarreia/imunologia , Endoscopia Gastrointestinal , Feminino , Humanos , Lipopolissacarídeos/sangue , Masculino , Desnutrição Aguda Grave/imunologia
9.
PLoS Negl Trop Dis ; 10(4): e0004600, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27050312

RESUMO

INTRODUCTION: Environmental enteropathy (EE) is associated with growth failure, micronutrient malabsorption and impaired responses to oral vaccines. We set out to define cellular mechanisms of impaired barrier function in EE and explore protective mechanisms. METHODS: We studied 49 adults with environmental enteropathy in Lusaka, Zambia using confocal laser endomicroscopy (CLE); histology, immunohistochemistry and mRNA sequencing of small intestinal biopsies; and correlated these with plasma lipopolysaccharide (LPS) and a zinc uptake test. RESULTS: CLE images (median 134 for each study) showed virtually ubiquitous small intestinal damage. Epithelial defects, imaged by histology and claudin 4 immunostaining, were predominantly seen at the tips of villi and corresponded with leakage imaged in vivo by CLE. In multivariate analysis, circulating log-transformed LPS was correlated with cell shedding events (ß = 0.83; P = 0.035) and with serum glucagon-like peptide-2 (ß = -0.13; P = 0.007). Zinc uptake from a test dose of 25mg was attenuated in 30/47 (64%) individuals and in multivariate analysis was reduced by HIV, but positively correlated with GLP-2 (ß = 2.72; P = 0.03). There was a U-shaped relationship between circulating LPS and villus surface area. Transcriptomic analysis identified 23 differentially expressed genes in severe enteropathy, including protective peptides and proteins. CONCLUSIONS: Confocal endomicroscopy, claudin 4 immunostaining and histology identify epithelial defects which are probably sites of bacterial translocation, in the presence of which increased epithelial surface area increases the burden of translocation. GLP 2 and other protective peptides may play an important role in mucosal protection in EE.


Assuntos
Exposição Ambiental , Gastroenteropatias/patologia , Histocitoquímica , Microscopia , Biópsia , Perfilação da Expressão Gênica , Imuno-Histoquímica , Lipopolissacarídeos/análise , Plasma/química , Análise de Sequência de RNA , Zâmbia , Zinco/metabolismo
10.
Liver Int ; 36(1): 145-50, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26058680

RESUMO

BACKGROUND & AIMS: Cirrhosis is the main cause of portal hypertension worldwide but schistosomiasis dominates in much of the tropics. The seroprevalence of Schistosoma mansoni is up to 77% in endemic parts of Zambia. Morbidity is attributed to portal hypertension causing variceal bleeding which can be fatal. Bacterial translocation is associated with portal hypertension in cirrhosis but this is almost unexplored in hepatosplenic schistosomiasis. Liver biopsy is usually used to assess fibrosis although it is invasive and prone to sampling error. We aimed to investigate translocation, fibrosis and inflammatory makers in a case-control study of schistosomiasis at the University Teaching Hospital, Lusaka, Zambia. METHODS: Patients had oesophageal varices, but were negative for human immunodeficiency virus, hepatitis B and C viruses. Plasma lipopolysaccharide binding protein was used as a marker of translocation while hyaluronan and laminin measured liver fibrosis. Inflammatory markers were measured in blood. Controls were patients with non-specific abdominal pain who had normal endoscopy. RESULTS: Median (interquartile range) lipopolysaccharide binding protein was elevated in patients [44.3 ng/ml (35.7, 57.1)] compared to controls [30.7 ng/ml (30.4, 35.5), P < 0.0001]. Hyaluronan was higher in patients [111.6 ng/ml (39.1, 240.3)] compared to controls [21.0 ng/ml (12.4, 37.6), P < 0.0001] and so was laminin [2.2 µg/ml (1.0, 3.7)] compared to controls [0.9 µg/ml (0.7, 1.2), P = 0.0015]. Inflammatory markers, except C-reactive protein, were elevated in patients. CONCLUSIONS: These data suggest that the bacterial translocation contributes to systemic inflammation in hepatosplenic schistosomiasis. Elevated fibrotic markers suggest they may be useful in diagnosing and monitoring periportal fibrosis.


Assuntos
Proteínas de Transporte/sangue , Ácido Hialurônico/sangue , Hipertensão Portal/etiologia , Laminina/sangue , Cirrose Hepática/etiologia , Glicoproteínas de Membrana/sangue , Esquistossomose mansoni , Proteínas de Fase Aguda , Adulto , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Humanos , Hipertensão Portal/diagnóstico , Inflamação/sangue , Cirrose Hepática/sangue , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Esquistossomose mansoni/sangue , Esquistossomose mansoni/complicações , Esquistossomose mansoni/diagnóstico , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/fisiopatologia , Estatística como Assunto , Zâmbia/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA