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1.
Mo Med ; 114(2): 125-128, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-30228559

RESUMO

This review seeks to educate clinicians and advocate for patients having acute-onset pediatric autoimmune encephalopathy. Primary care providers caring for children are not fully aware of the debilitating illness that changes the life of a child and a family overnight. Our goal is to heighten awareness of a) the initial diagnosis, b) treatment and c) information about referral of affected children by health professionals in Missouri and surrounding states.

2.
J Pediatr ; 175: 68-73.e3, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27260839

RESUMO

OBJECTIVE: To evaluate the safety and explore the efficacy of recombinant human lactoferrin (talactoferrin [TLf]) to reduce infection. STUDY DESIGN: We conducted a randomized, double blind, placebo-controlled trial in infants with birth weight of 750-1500 g. Infants received enteral TLf (n = 60) or placebo (n = 60) on days 1 through 28 of life; the TLf dose was 150 mg/kg every 12 hours. Primary outcomes were bacteremia, pneumonia, urinary tract infection, meningitis, and necrotizing enterocolitis (NEC). Secondary outcomes were sepsis syndrome and suspected NEC. We recorded clinical, laboratory, and radiologic findings, along with diseases and adverse events, in a database used for statistical analyses. RESULTS: Demographic data were similar in the 2 groups of infants. We attributed no enteral or organ-specific adverse events to TLf. There were 2 deaths in the TLf group (1 each due to posterior fossa hemorrhage and postdischarge sudden infant death), and 1 death in the placebo group, due to NEC. The rate of hospital-acquired infections was 50% lower in the TLf group compared with the placebo group (P < .04), including fewer blood or line infections, urinary tract infections, and pneumonia. Fourteen infants in the TLf group weighing <1 kg at birth had no gram-negative infections, compared with only 3 of 14 such infants in the placebo group. Noninfectious outcomes were not statistically significantly different between the 2 groups, and there were no between-group differences in growth or neurodevelopment over a 1-year posthospitalization period. CONCLUSION: We found no clinical or laboratory toxicity and a trend toward less infectious morbidity in the infants treated with TLf. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00854633.


Assuntos
Infecção Hospitalar/prevenção & controle , Infecções por Bactérias Gram-Negativas/prevenção & controle , Infecções por Bactérias Gram-Positivas/prevenção & controle , Doenças do Prematuro/prevenção & controle , Lactoferrina/uso terapêutico , Substâncias Protetoras/uso terapêutico , Administração Oral , Bacteriemia/prevenção & controle , Método Duplo-Cego , Enterocolite Necrosante/prevenção & controle , Feminino , Seguimentos , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Meningite/prevenção & controle , Pneumonia/prevenção & controle , Sepse/prevenção & controle , Resultado do Tratamento , Infecções Urinárias/prevenção & controle
3.
J Pediatr ; 173 Suppl: S37-42, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27234409

RESUMO

UNLABELLED: The purpose of this study is to evaluate the effects of enteral lactoferrin on the fecal microbiome and contrast those influences with the neonatal intensive care unit (NICU) environment. We theorized that lactoferrin and the NICU habitat shape the fecal microbial composition of very preterm infants. Although functions attributed to lactoferrin include intestinal immune system development and emergence of a healthy gut microbiota, evidence is limited. Twenty-one very low birth weight (VLBW <1500 g) infants received twice-daily talactoferrin (TLf, a drug designation for recombinant human lactoferrin) or its excipient by gastric gavage from day 1-28 of life. Twenty-four-hour fecal samples were collected on day 21 of life and compared with fecal operational taxonomy units (OTUs) in treated and control infants in 2 NICUs. Workflow included fecal DNA isolation, generation of amplicons for the V1-V3 region of bacterial 16S ribosomal RNA, and sequencing of a gel-purified multiplex amplicon library using a Roche 454 GS FLX Titanium (Roche, Branford, Connecticut) platform and protocols. Fecal OTUs per infant were higher in NICU 1 vs NICU 2 (P < .001), consistent with fewer antibiotic days (P < .02) and a shorter duration of parenteral nutrition (P < .007) in NICU 1. Proteobacteria and Firmicutes were the major phyla in infants treated with TLf and placebo. Among Enterobacteriaceae, TLf prophylaxis reduced Enterobacter and Klebsiella, but increased Citrobacter in feces of VLBW infants. Citrobacter caused no neonatal infections in the study population. OTUs for Clostridiaceae increased in NICU 1 among infants treated with TLf. Importantly, OTUs of staphylococci were barely detectable in both NICUs among infants fed TLf. Fewer hospital-acquired infections occurred in infants treated with TLf vs controls, although the reduction was seen mostly in coagulase-negative staphylococci-related bloodstream and central line infections (P = .06). TLf modified the fecal microbiome in VLBW infants, but care practices in the NICU habitat also contributed. Future research must establish whether elimination vs enrichment of gut-related microbiota reduces clinically significant hospital-acquired infections and promotes a healthy commensal microflora in the intestines of VLBW infants. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00854633.


Assuntos
Anti-Infecciosos/farmacologia , Fezes/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Recém-Nascido Prematuro , Recém-Nascido de muito Baixo Peso , Terapia Intensiva Neonatal/métodos , Lactoferrina/farmacologia , Administração Oral , Anti-Infecciosos/uso terapêutico , Infecção Hospitalar/prevenção & controle , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Fenômenos Fisiológicos da Nutrição do Lactente , Recém-Nascido , Doenças do Prematuro/prevenção & controle , Unidades de Terapia Intensiva Neonatal , Lactoferrina/uso terapêutico , Masculino , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Resultado do Tratamento
4.
Biochem Biophys Res Commun ; 467(4): 766-70, 2015 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-26478433

RESUMO

Health policy precludes neonatal vaccination against influenza. Hence, morbidity and mortality are high under 6 months of age. Lactoferrin may activate diminished numbers of dysfunctional dendritic cells and reverse neonatal vaccine failures. Aluminum hydroxide/ALUM recruits neutrophils that secrete lactoferrin at deposition sites of antigen. We theorized lactoferrin + influenza antigen initiates an equivalent antibody response compared to ALUM. Three-day-old mice received subcutaneously 30 µg of H1N1 hemagglutinin + 200 µg of bovine lactoferrin versus hemagglutinin + ALUM. Controls received hemagglutinin, lactoferrin, or ALUM. After 21 days, sera measured anti-H1N1 (ELISA) and neutralizing antibody (plaque assays). ELISA detected equal antibody production with lactoferrin + hemagglutinin compared to hemagglutinin + ALUM; both sera also neutralized H1N1 virus at a 1:20 dilution (p < 0.01). Controls had no anti-H1N1 antibody. Neonates given lactoferrin had no anaphylaxis when challenged four weeks later. Lactoferrin is a safe and effective adjuvant for inducing antibody against influenza in neonates.


Assuntos
Adjuvantes Imunológicos/farmacologia , Lactoferrina/farmacologia , Infecções por Orthomyxoviridae/imunologia , Vacinação/métodos , Hidróxido de Alumínio/imunologia , Hidróxido de Alumínio/farmacologia , Animais , Animais Recém-Nascidos , Bovinos , Cães , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/farmacologia , Vírus da Influenza A Subtipo H1N1/patogenicidade , Lactoferrina/imunologia , Células Madin Darby de Rim Canino/virologia , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologia
5.
Neonatology ; 108(2): 137-42, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26159186

RESUMO

BACKGROUND: Eosinophils infiltrate intestinal tissue during necrotizing enterocolitis (NEC) and adult bowel diseases. We theorized that epithelial damage causes eosinophilic activation and recruitment at NEC onset. OBJECTIVE: We studied the relationship between persistent blood eosinophilia and medical or surgical complications during NEC. METHODS: NEC cases and controls at MU Children's Hospital (2008-2013) underwent review. A Likert scale measured NEC severity. We utilized an SPSS database for statistical analyses. RESULTS: Of 50 NEC cases, infants in group 1 (n = 15) had eosinophilia <2 days after onset and those in group 2 (n = 25) had NEC but no persistent eosinophilia. Group 3 (n = 46) consisted of controls, i.e. infants without NEC matched for birth weight and gestational age and group 4 (n = 4) of preterm infants with infection and ≤5 days of eosinophilia. Hematologic assessment defined persistent eosinophilia as ≥5% eosinophils for ≥5 days after NEC onset. Absolute eosinophil counts were 2 times higher in group 1 than in group 2 (p = 0.002). The mean duration of eosinophilia was 8 days in group 1 versus 1 day in group 2 (p < 0.001). A Likert score of NEC severity was 3-fold higher in group 1 than in group 2 (p < 0.001). Compared to group 2, group 1 infants were 8 times more likely to have hepatic fibrosis or intestinal strictures. CONCLUSIONS: Early persistent blood eosinophilia is not currently a predictor of complications after the onset of NEC. This biomarker identifies immature infants at a high risk for adverse outcomes during NEC convalescence.


Assuntos
Citocinas/sangue , Enterocolite Necrosante/complicações , Eosinofilia/sangue , Recém-Nascido Prematuro/sangue , Biomarcadores/sangue , Peso ao Nascer , Bases de Dados Factuais , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Masculino , Missouri , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença
6.
J Immunol ; 195(2): 507-18, 2015 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-26034171

RESUMO

Neonatal immunity exhibits weak Th1 but excessive Th2 responses, and the underlying mechanisms remain elusive. In this article, we show that neonatal basophils readily produce IL-4, a cytokine that proved to be pivotal in shaping the programs of both lymphocyte subsets. Besides promoting Th2 programs, IL-4 is captured by the IL-4 heteroreceptor (IL-4Rα/IL-13Rα1) expressed on dendritic cells and instigates IL-12 downregulation. Under these circumstances, differentiating Th1 cells upregulate IL-13Rα1, leading to an unusual expression of the heteroreceptor, which will serve as a death marker for these Th1 cells during rechallenge with Ag. The resulting Th1/Th2 imbalance impacts childhood immunity culminating in sensitivity to allergic reactions, susceptibility to microbial infection and perhaps poor efficacy of pediatric vaccines.


Assuntos
Basófilos/imunologia , Células Dendríticas/imunologia , Regulação da Expressão Gênica no Desenvolvimento/imunologia , Células Th1/imunologia , Células Th2/imunologia , Transferência Adotiva , Sequência de Aminoácidos , Animais , Animais Recém-Nascidos , Basófilos/citologia , Basófilos/efeitos dos fármacos , Basófilos/transplante , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/transplante , Feminino , Imunidade Inata , Interleucina-12/genética , Interleucina-12/imunologia , Subunidade alfa1 de Receptor de Interleucina-13/genética , Subunidade alfa1 de Receptor de Interleucina-13/imunologia , Interleucina-4/genética , Interleucina-4/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Dados de Sequência Molecular , Ovalbumina/farmacologia , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/imunologia , Transdução de Sinais , Células Th1/citologia , Células Th1/efeitos dos fármacos , Células Th1/transplante , Células Th2/citologia , Células Th2/efeitos dos fármacos , Células Th2/transplante
7.
Pediatr Res ; 77(1-2): 127-35, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25303278

RESUMO

The conceptual framework for a gut-brain axis has existed for decades. The Human Microbiome Project is responsible for establishing intestinal dysbiosis as a mediator of inflammatory bowel disease, obesity, and neurodevelopmental disorders in adults. Recent advances in metagenomics implicate gut microbiota and diet as key modulators of the bidirectional signaling pathways between the gut and brain that underlie neurodevelopmental and psychiatric disorders in adults. Evidence linking intestinal dysbiosis to neurodevelopmental disease outcomes in preterm infants is emerging. Recent clinical studies show that intestinal dysbiosis precedes late-onset neonatal sepsis and necrotizing enterocolitis in intensive care nurseries. Moreover, strong epidemiologic evidence links late-onset neonatal sepsis and necrotizing enterocolitis in long-term psychomotor disabilities of very-low-birth-weight infants. The notion of the gut-brain axis thereby supports that intestinal microbiota can indirectly harm the brain of preterm infants. In this review, we highlight the anatomy and physiology of the gut-brain axis and describe transmission of stress signals caused by immune-microbial dysfunction in the gut. These messengers initiate neurologic disease in preterm infants. Understanding neural and humoral signaling through the gut-brain axis will offer insight into therapeutic and dietary approaches that may improve the outcomes of very-low-birth-weight infants.


Assuntos
Encéfalo/fisiologia , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/fisiologia , Doenças do Recém-Nascido/microbiologia , Microbiota/fisiologia , Modelos Biológicos , Transdução de Sinais/fisiologia , Disbiose/microbiologia , Enterocolite Necrosante/microbiologia , Humanos , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Sepse/microbiologia
8.
Curr Opin Pediatr ; 26(2): 146-50, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24503532

RESUMO

PURPOSE OF REVIEW: There is an intense interest among neonatal caregivers as to whether lactoferrin given enterally may reduce the incidence of necrotizing enterocolitis in preterm infants. This review presents scientific and clinical evidence that lactoferrin alleviates or prevents this life-threatening disease. RECENT FINDINGS: Preclinical studies in neonatal rats showed that lactoferrin given orally before enteral infection with pathogenic Escherichia coli reduced bacteremia and mortality. A multicentered clinical trial found that very low-birth weight preterm infants given bovine lactoferrin had a significant reduction in late-onset sepsis; there was also a trend towards a diminished incidence of necrotizing enterocolitis. Although multicentered trials of lactoferrin use in preterm infants are near completion, regulatory burdens required to bring lactoferrin to the bedside may limit its availability. SUMMARY: Extremely preterm infants should receive colostrum, a natural lactoferrin concentrate, immediately after birth and, ideally, continue on breast milk throughout the hospital stay. This practice appears well tolerated, but additional experience will tell us whether this practice reduces the prevalence of necrotizing enterocolitis.


Assuntos
Colostro , Enterocolite Necrosante/prevenção & controle , Trato Gastrointestinal/imunologia , Inflamação/imunologia , Lactoferrina/uso terapêutico , Sepse/prevenção & controle , Animais , Nutrição Enteral , Enterocolite Necrosante/imunologia , Humanos , Imunidade Inata , Incidência , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/prevenção & controle , Recém-Nascido de muito Baixo Peso , Lactoferrina/administração & dosagem , Lactoferrina/imunologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Sepse/imunologia
9.
JPEN J Parenter Enteral Nutr ; 38(6): 711-6, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23963690

RESUMO

BACKGROUND: Preliminary studies suggest that fish-oil lipid emulsion given parenterally to very preterm infants reduces the severity of retinopathy (ROP) and cholestasis. METHODS: Infants weighing <1250 g at birth were randomly allocated to 2 groups: an experimental group of 60 infants that received an intravenous (IV) soybean, olive oil, and fish oil emulsion, and a control group of 70 infants that was given a parenteral soybean and olive oil emulsion. Plasma and erythrocyte concentrations of docosahexaenoic acid (DHA) were determined using a high-performance liquid chromatography-mass spectrometry analysis. RESULTS: Nine infants in the fish oil group required laser therapy for ROP compared with 22 infants in the standard intralipid group (risk ratio [RR], 0.48; 95% confidence interval [CI], 0.24-0.96). Three infants in the fish oil group developed cholestasis compared with 20 infants in the standard intralipid group (RR, 0.18; 95% CI, 0.055-0.56). The mean plasma DHA concentrations in treated infants were 2.9-fold higher in the fish oil group than in control infants on the 7th and 14th days of life. The mean DHA content in erythrocytes of treated infants was 4.5-fold and 2.7-fold higher compared with controls at 7 and 14 days of age. CONCLUSIONS: Premature infants receiving an IV fat emulsion containing fish oil had less ROP requiring laser treatment and less cholestasis than those receiving a standard lipid emulsion. These infants also had higher plasma and erythrocyte DHA levels at 7 and 14 days, suggesting potential long-term neurodevelopmental benefits.


Assuntos
Emulsões Gordurosas Intravenosas/uso terapêutico , Óleos de Peixe/uso terapêutico , Recém-Nascido de muito Baixo Peso , Retinopatia da Prematuridade/prevenção & controle , Desenvolvimento Infantil/efeitos dos fármacos , Colestase/sangue , Colestase/prevenção & controle , Ácidos Docosa-Hexaenoicos/sangue , Ácidos Docosa-Hexaenoicos/uso terapêutico , Emulsões/uso terapêutico , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Azeite de Oliva , Nutrição Parenteral/métodos , Fosfolipídeos/uso terapêutico , Óleos de Plantas/uso terapêutico , Estudos Prospectivos , Retinopatia da Prematuridade/sangue , Óleo de Soja/uso terapêutico , Resultado do Tratamento
10.
Neonatology ; 105(1): 14-24, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24193200

RESUMO

The aim of this article is to educate neonatal caregivers about metagenomics. This scientific field uses novel and ever changing molecular methods to identify how infants become colonized with microbes after birth. Publications using metagenomics appear infrequently in the neonatal literature because clinicians are unaccustomed to the analytical techniques, data interpretation, and illustration of the results. This review covers those areas. After a brief introduction of neonatal citations forthcoming from metagenomic studies, the following topics are covered: (1) the history of metagenomics, (2) a description of current and emerging instruments used to define microbial populations in human organs, and (3) how extensive databases generated by genome analyzers are examined and presented to readers. Clinicians may feel like they are learning a new language; however, they will appreciate this task is essential to understanding and practicing neonatal medicine in the future.


Assuntos
Pesquisa Biomédica/tendências , Microbiota/genética , Neonatologia/educação , Humanos , Recém-Nascido , Metagenômica/métodos , Filogenia , Análise de Sequência de DNA/métodos
11.
Eur J Immunol ; 44(3): 842-55, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24281978

RESUMO

In this study, we examined the role IL-13 receptor alpha 1 (IL-13Rα1) plays in macrophage differentiation and function. The findings indicate that IL-13Rα1 is expressed on the M2 but not on the M1 subset of macrophages and specifically heterodimerizes with the IL-4Rα chain to form a type II receptor, which controls the differentiation and function of these cells. Indeed, BM cells from IL-13Rα1(+/+) and IL-13Rα1(-/-) mice yield equivalent numbers of macrophages when cultured under M2 polarizing conditions. However, IL-13Rα1(-/-) BM cells yield a much higher number of macrophages than IL-13Rα1(+/+) BM cells when the differentiation is carried out under M1-polarizing conditions. Further analyses indicated that macrophages that express IL-13Rα1 also display surface markers associated with an M2 phenotype. In addition, the IL-13Rα1(+) macrophages were highly efficient in phagocytizing zymosan bioparticles both in vitro and in vivo, and supported differentiation of naïve T cells to a Th2 phenotype. Finally, when stimulated by IL-13, a cytokine that uses the heteroreceptor, the cells were able to phosphorylate STAT6 efficiently. These previously unrecognized findings indicate that IL-13Rα1 serves as a marker for M2 macrophages and the resulting heteroreceptor influences both their differentiation and function.


Assuntos
Subunidade alfa1 de Receptor de Interleucina-13/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Animais , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Expressão Gênica , Imunofenotipagem , Interleucina-13/farmacologia , Subunidade alfa1 de Receptor de Interleucina-13/genética , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Knockout , Monócitos/imunologia , Monócitos/metabolismo , Fenótipo , Fosforilação/efeitos dos fármacos , Característica Quantitativa Herdável , Fator de Transcrição STAT6/metabolismo
12.
Clin Perinatol ; 40(1): 79-91, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23415265

RESUMO

Lactoferrin (LF) is a multifunctional protein and a member of the transferrin family. LF and lysozyme in breast milk kill bacteria. In the stomach, pepsin digests and releases a potent peptide antibiotic called lactoferricin from native LF. The antimicrobial characteristics of LF may facilitate a healthy intestinal microbiome. LF is the major whey in human milk; its highest concentration is in colostrum. This fact highlights early feeding of colostrum and also fresh mature milk as a way to prevent necrotizing enterocolitis.


Assuntos
Colostro/metabolismo , Enterocolite Necrosante/prevenção & controle , Intestino Delgado/imunologia , Lactoferrina/metabolismo , Leite Humano/metabolismo , Animais , Colostro/imunologia , Enterocolite Necrosante/terapia , Humanos , Recém-Nascido , Intestino Delgado/microbiologia , Lactoferrina/imunologia , Lactoferrina/uso terapêutico , Metagenoma/imunologia , Leite/metabolismo , Leite Humano/química , Leite Humano/imunologia , Muramidase/imunologia
14.
Neonatology ; 103(1): 10-20, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23006982

RESUMO

Current models of necrotizing enterocolitis (NEC) propose that intraluminal microbes destroy intestinal mucosa and activate an inflammatory cascade that ends in necrosis. We suggest an alternate hypothesis wherein NEC is caused by injury to Paneth cells (PCs) in the intestinal crypts. PCs are specialized epithelia that protect intestinal stem cells from pathogens, stimulate stem cell differentiation, shape the intestinal microbiota, and assist in repairing the gut. Our novel model of NEC uses neonatal mice and ablates PCs followed by enteral infection. We contrast this model with other animal examples of NEC and the clinical disease. Selective destruction of PCs using dithizone likely releases tumor necrosis factor-α and other inflammatory mediators. We propose that this event produces inflammation in the submucosa, generates platelet-activating factor, and induces a coagulopathy. The role of PCs in NEC is consistent with the onset of disease in preterm infants after a period of PC-related maturation, the central role of PCs in crypt-related homeostasis, the anatomic location of pneumatosis intestinalis close to the crypts, and the proximity of PCs to occluded blood vessels that cause coagulation necrosis of the intestinal villi. We offer this hypothesis to promote new thoughts about how NEC occurs and its potential prevention.


Assuntos
Enterocolite Necrosante/etiologia , Celulas de Paneth/patologia , Celulas de Paneth/fisiologia , Animais , Formação de Conceito , Doença/etiologia , Enterocolite Necrosante/patologia , Enterocolite Necrosante/prevenção & controle , Saúde , Humanos , Recém-Nascido , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Camundongos , Modelos Biológicos
15.
Dis Model Mech ; 5(4): 522-32, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22328592

RESUMO

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in premature infants. During NEC pathogenesis, bacteria are able to penetrate innate immune defenses and invade the intestinal epithelial layer, causing subsequent inflammation and tissue necrosis. Normally, Paneth cells appear in the intestinal crypts during the first trimester of human pregnancy. Paneth cells constitute a major component of the innate immune system by producing multiple antimicrobial peptides and proinflammatory mediators. To better understand the possible role of Paneth cell disruption in NEC, we quantified the number of Paneth cells present in infants with NEC and found that they were significantly decreased compared with age-matched controls. We were able to model this loss in the intestine of postnatal day (P)14-P16 (immature) mice by treating them with the zinc chelator dithizone. Intestines from dithizone-treated animals retained approximately half the number of Paneth cells compared with controls. Furthermore, by combining dithizone treatment with exposure to Klebsiella pneumoniae, we were able to induce intestinal injury and inflammatory induction that resembles human NEC. Additionally, this novel Paneth cell ablation model produces NEC-like pathology that is consistent with other currently used animal models, but this technique is simpler to use, can be used in older animals that have been dam fed, and represents a novel line of investigation to study NEC pathogenesis and treatment.


Assuntos
Enterocolite Necrosante/microbiologia , Enterocolite Necrosante/patologia , Intestino Delgado/microbiologia , Intestino Delgado/patologia , Klebsiella pneumoniae/fisiologia , Celulas de Paneth/microbiologia , Celulas de Paneth/patologia , Envelhecimento/patologia , Animais , Diferenciação Celular/efeitos dos fármacos , Grânulos Citoplasmáticos/metabolismo , Modelos Animais de Doenças , Ditizona , Nutrição Enteral , Enterocolite Necrosante/complicações , Enterocolite Necrosante/tratamento farmacológico , Humanos , Recém-Nascido , Inflamação/complicações , Inflamação/microbiologia , Inflamação/patologia , Intestino Delgado/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Camundongos , Celulas de Paneth/efeitos dos fármacos , Zinco/farmacologia , Zinco/uso terapêutico
16.
Pediatr Res ; 71(5): 546-51, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22322385

RESUMO

INTRODUCTION: Necrotizing enterocolitis (NEC) is a devastating disease of premature infants. Probiotics decrease the risk of NEC in clinical and experimental studies. Antimicrobial peptides protect the gut against noxious microbes and shape the commensal microbiota, but their role in NEC remains unclear. METHODS: To investigate the expression of antimicrobial peptides in experimental NEC and the impact of probiotics on their expression, premature rats were divided into three groups: dam fed (DF), hand fed with formula (FF), or hand fed with formula containing Bifidobacterium bifidum (FF + BIF). All groups were exposed to asphyxia and cold stress. RESULTS: Like in human ontogeny, the rat pup has low expression of Paneth cell antimicrobials, which increases rapidly during normal development. The expression of lysozyme, secretory phospholipase A(2) (sPLA(2)), pancreatic-associated proteins 1 and 3 mRNA was elevated in the FF group with a high incidence of NEC, as compared with the DF and FF + BIF groups where the disease was attenuated. DISCUSSION: We conclude that induction of antimicrobial peptides occurs in experimental NEC similar to that reported in human disease and is attenuated when disease is averted by probiotic B. bifidum. The induction of antimicrobial peptides is likely an adaptive mucosal response that is often not sufficient to prevent disease in the premature gut.


Assuntos
Bifidobacterium , Modelos Animais de Doenças , Enterocolite Necrosante/microbiologia , Peptídeos/metabolismo , Probióticos , Proteínas/metabolismo , Animais , Animais Recém-Nascidos , Anti-Infecciosos , Sequência de Bases , Primers do DNA , Enterocolite Necrosante/metabolismo , Enterocolite Necrosante/terapia , Expressão Gênica , Imuno-Histoquímica , Peptídeos/genética , Reação em Cadeia da Polimerase , Proteínas/genética , Ratos , Ratos Sprague-Dawley
19.
Clin Perinatol ; 37(3): 565-79, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20813271

RESUMO

Bacterial translocation from the gastrointestinal tract is an important pathway initiating late-onset sepsis and necrotizing enterocolitis in very low-birth-weight infants. The emerging intestinal microbiota, nascent intestinal epithelia, naive immunity, and suboptimal nutrition (lack of breast milk) have roles in facilitating bacterial translocation. Feeding lactoferrin, probiotics, or prebiotics has presented exciting possibilities to prevent bacterial translocation in preterm infants, and clinical trials will identify the most safe and efficacious prevention and treatment strategies.


Assuntos
Translocação Bacteriana , Enterocolite Necrosante/prevenção & controle , Mucosa Intestinal/microbiologia , Intestinos/microbiologia , Probióticos/uso terapêutico , Enterocolite Necrosante/microbiologia , Humanos , Recém-Nascido
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