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1.
J Infect Dis ; 223(11): 1943-1947, 2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32992328

RESUMO

Circumsporozoite protein (CSP) coats the Plasmodium falciparum sporozoite surface and is a major malaria subunit vaccine target. We measured epitope-specific reactivity to field-derived CSP haplotypes in serum samples from Malian adults and children on a custom peptide microarray. Compared to children, adults showed greater antibody responses and responses to more variants in regions proximal to and within the central repeat region. Children acquired short-lived immunity to an epitope proximal to the central repeat region but not to the central repeat region itself. This approach has the potential to differentiate immunodominant from protective epitope-specific responses when combined with longitudinal infection data.


Assuntos
Anticorpos Antiprotozoários/imunologia , Formação de Anticorpos , Vacinas Antimaláricas , Malária Falciparum , Adulto , Criança , Epitopos , Humanos , Vacinas Antimaláricas/imunologia , Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Mali , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Vacinas de Subunidades Antigênicas/imunologia
2.
Malar J ; 18(1): 273, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31409360

RESUMO

BACKGROUND: Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP1) antigens play a critical role in host immune evasion. Serologic responses to these antigens have been associated with protection from clinical malaria, suggesting that antibodies to PfEMP1 antigens may contribute to natural immunity. The first N-terminal constitutive domain in a PfEMP1 is the Duffy binding-like alpha (DBL-α) domain, which contains a 300 to 400 base pair region unique to each particular protein (the DBL-α "tag"). This DBL-α tag has been used as a marker of PfEMP1 diversity and serologic responses in malaria-exposed populations. In this study, using sera from a malaria-endemic region, responses to DBL-α tags were compared to responses to the corresponding entire DBL-α domain (or "parent" domain) coupled with the succeeding cysteine-rich interdomain region (CIDR). METHODS: A protein microarray populated with DBL-α tags, the parent DBL-CIDR head structures, and downstream PfEMP1 protein fragments was probed with sera from Malian children (aged 1 to 6 years) and adults from the control arms of apical membrane antigen 1 (AMA1) vaccine clinical trials before and during a malaria transmission season. Serological responses to the DBL-α tag and the DBL-CIDR head structure were measured and compared in children and adults, and throughout the season. RESULTS: Malian serologic responses to a PfEMP1's DBL-α tag region did not correlate with seasonal malaria exposure, or with responses to the parent DBL-CIDR head structure in either children or adults. Parent DBL-CIDR head structures were better indicators of malaria exposure. CONCLUSIONS: Larger PfEMP1 domains may be better indicators of malaria exposure than short, variable PfEMP1 fragments such as DBL-α tags. PfEMP1 head structures that include conserved sequences appear particularly well suited for study as serologic predictors of malaria exposure.


Assuntos
Antígenos de Protozoários/imunologia , Malária Falciparum/imunologia , Plasmodium falciparum/fisiologia , Proteínas de Protozoários/imunologia , Adulto , Criança , Pré-Escolar , Sequência Conservada , Humanos , Lactente , Pessoa de Meia-Idade , Estrutura Terciária de Proteína , Adulto Jovem
3.
AJR Am J Roentgenol ; 212(2): 456-460, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30476458

RESUMO

OBJECTIVE: The purpose of this study was to evaluate the clinical utility of Deauville scores in interpretation of end-of-chemotherapy FDG PET scans. CONCLUSION: Deauville scores improve the clinical utility of end-of-chemotherapy PET, as evidenced by an increase in positive predictive value to 72.7% from 44.4% on the basis of report alone. The negative predictive value remains greater than 95%.


Assuntos
Fluordesoxiglucose F18 , Doença de Hodgkin/diagnóstico por imagem , Doença de Hodgkin/tratamento farmacológico , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Recidiva Local de Neoplasia/epidemiologia , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
4.
Artigo em Inglês | MEDLINE | ID: mdl-30930205

RESUMO

Given climate change projections, the limited ability of fish reared in sea-cages to behaviourally thermoregulate, and that thermal tolerance may be heritable, studies that examine family-related differences in upper thermal tolerance are quite relevant to the aquaculture industry. Thus, we investigated the upper thermal tolerance of 15 Atlantic cod (Gadus morhua L.) families by challenging them with acute (2 °C h-1) and incremental (1 °C every 4 days) temperature increases (CTmax and ITmax tests, respectively) under normoxia (~ 100% air saturation) and mild hypoxia (~ 75% air sat.). The cod's CTmax was 22.5 ±â€¯0.1 °C (mean ±â€¯S.E.) during normoxia and 21.8 ±â€¯0.1 °C during hypoxia (P < 0.001); and these two CTmax values were significantly correlated across families. In both the normoxic and hypoxic ITmax tests, feed intake fell by ~50% between 17 and 18 °C, and stopped entirely by 21 °C. No mortalities were observed under 20 °C in the normoxic and hypoxic ITmax tests, and the ITmax value was ~21.7 °C in both groups. Differences in the upper thermal tolerance between families were only observed in the CTmax experiment. No correlation was found between the specific growth rate and the CTmax of the families. Further, no correlation existed between CTmax and ITmax. This study is the first to compare the thermal tolerance of fish families to both CTmax and ITmax challenges, and the data: 1) suggest that the Atlantic cod is quite tolerant of acute (i.e., hours) or short-term (i.e., weeks) exposure to high water temperatures (i.e., up to 20 °C); 2) indicate that it might be difficult to select fish with higher ITmax values; and 3) question the relevance of CTmax for selecting fish that are destined for sea-cages where temperatures slowly warm over the summer.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Gadus morhua/crescimento & desenvolvimento , Hipóxia , Termotolerância/fisiologia , Animais , Aquicultura , Mudança Climática , Temperatura Alta
5.
Proteomics ; 18(2)2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29266845

RESUMO

The development of vaccines against malaria and serodiagnostic tests for detecting recent exposure requires tools for antigen discovery and suitable animal models. The protein microarray is a high-throughput, sample sparing technique, with applications in infectious disease research, clinical diagnostics, epidemiology, and vaccine development. We recently demonstrated Qdot-based indirect immunofluorescence together with portable optical imager ArrayCAM using single isotype detection could replicate data using the conventional laser confocal scanner system. We developed a multiplexing protocol for simultaneous detection of IgG, IgA, and IgM and compared samples from a controlled human malaria infection model with those from controlled malaria infections of Aotus nancymaae, a widely used non-human primate model of human malaria. IgG profiles showed the highest concordance in number of reactive antigens; thus, of the 139 antigens recognized by human IgG antibody, 111 were also recognized by Aotus monkeys. Interestingly, IgA profiles were largely non-overlapping. Finally, on the path toward wider deployment of the portable platform, we show excellent correlations between array data obtained in five independent laboratories around the United States using the multiplexing protocol (R2 : 0.60-0.92). This study supports the use of this platform for wider deployment, particularly in endemic areas where such a tool will have the greatest impact on global human health.


Assuntos
Imunoensaio/métodos , Imunoglobulina G/análise , Malária Falciparum/diagnóstico , Análise Serial de Proteínas/métodos , Proteoma/análise , Animais , Aotidae , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Imunoglobulina A/análise , Imunoglobulina M/análise , Malária Falciparum/metabolismo , Malária Falciparum/parasitologia , Plasmodium falciparum/isolamento & purificação , Pontos Quânticos
6.
AJR Am J Roentgenol ; 210(5): 1088-1091, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29489406

RESUMO

OBJECTIVE: The purpose of this study was to determine whether routine pelvic imaging is necessary during postoperative surveillance of pathologic T2-T4 renal cell carcinoma after nephrectomy for curative intent. MATERIALS AND METHODS: A retrospective single-institution cohort study with 603 subjects undergoing partial or radical nephrectomy of T2-T4 renal cell carcinoma with curative intent was conducted from January 1, 2000, through December 31, 2015. Clinical and imaging (CT or MRI) follow-up findings were evaluated in a prospectively maintained registry to determine the timing and location of recurrent and metastatic disease. The primary outcome was the proportion of subjects with positive or equivocal findings in the pelvis and negative findings in the chest and abdomen. Binomial CIs were calculated and compared with a prespecified minimum detection threshold of 5%. RESULTS: The T category distribution was as follows: T2 (28.9% [174/603]), T3 (70.3% [424/603]), and T4 (0.8% [5/603]). Most (81.8% [493/603]) of the patients underwent radical nephrectomy, and 27.0% (163/603) had recurrence or metastasis (mean time to first recurrence, 600 ± 695 days). Pelvic imaging findings were negative in 97.0% (585/603) of cases. Four subjects (0.7% [95% CI, 0.2-1.7%]) had isolated positive findings in the pelvis (p < 0.0001 vs the 5% threshold). Two (0.3% overall [95% CI, 0.04-1.1%]) of these positive findings were in subjects who did not have symptoms. CONCLUSION: Routine pelvic imaging of patients undergoing surveillance for asymptomatic T2-T4 renal cell carcinoma after nephrectomy performed with curative intent has minimal value and probably should not be performed.


Assuntos
Carcinoma de Células Renais/diagnóstico por imagem , Carcinoma de Células Renais/patologia , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/patologia , Pelve/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Carcinoma de Células Renais/cirurgia , Feminino , Seguimentos , Humanos , Neoplasias Renais/cirurgia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico por imagem , Estadiamento de Neoplasias , Nefrectomia , Cuidados Pós-Operatórios , Estudos Retrospectivos
7.
AJR Am J Roentgenol ; 211(4): 896-900, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30106609

RESUMO

OBJECTIVE: The purpose of this study was to determine if extended PET acquisition times in the pelvis during PET/MRI increase detection rates of potentially metastatic lymph nodes in patients with rectal cancer. MATERIALS AND METHODS: Our study was approved by the institutional review board of the University of California, San Francisco. Twenty-two patients with biopsy-proven rectal cancer underwent imaging via simultaneous 3-T time-of-flight PET/MRI, with seven undergoing two separate PET/MRI examinations, for a total of 29 studies. Each examination included both a whole-body PET/MRI and a dedicated pelvic PET/MRI with both 3- and 15-minute PET acquisitions for the pelvis. Three radiologists interpreted each examination with PET only, MRI only, then combined PET and MRI examinations, using all available images. Additionally, the 3- and 15-minute PET acquisitions of the pelvis were reviewed separately by a single radiologist. RESULTS: A total of 94 lymph nodes were identified as abnormal on PET, all with MRI anatomic correlates. Of these, 37 (39.4%) were seen only on the dedicated 15-minute acquisition. Fifty-seven (60.6%) nodes measured 5 mm or less, including 29 (30.9%) seen only on the 15-minute acquisition. Thirty-one (33.0%) nodes measured 5.1-10 mm, including eight (25.8%) seen only on the 15-minute acquisition. Of the 17 subjects imaged for initial staging, 11 (64.7%) were upstaged as a result of the increased PET acquisition time (10 from N1 to N2 and one from N0 to N1). CONCLUSION: Longer PET acquisition times during PET/MRI for rectal cancer increases the number of FDG-avid lymph nodes detected without increasing scan time.


Assuntos
Imageamento por Ressonância Magnética , Imagem Multimodal , Tomografia por Emissão de Pósitrons/métodos , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/patologia , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Retrospectivos , Imagem Corporal Total
8.
Emerg Radiol ; 25(4): 375-380, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29502287

RESUMO

PURPOSE: Our aim was to assess and address the challenges radiology residents face when managing breast imaging emergencies on call and to determine if targeted educational interventions improved resident confidence and knowledge. METHODS: We created surveys to determine resident comfort level with and knowledge of appropriate management of breast imaging emergencies. We also created structured educational interventions to improve resident confidence and knowledge. The effectiveness of these interventions was assessed with pre- and post-intervention surveys given to the 43 residents at our institution. RESULTS: Thirty-six of the 43 residents at our institution completed both surveys. The results showed that 33 of 36 residents (91.7%) felt an increase in their comfort level after utilizing one or both of the interventions. There was also significant improvement in resident knowledge; the average resident score on the knowledge questions improved from 40 to 68% (p < 0.0001). CONCLUSION: Managing breast imaging emergencies on call can be challenging and stressful for residents. Educational interventions such as our targeted teaching tools can significantly improve resident confidence and knowledge. Presenting dedicated teaching materials directed at a previously identified knowledge deficit and source of stress significantly improved resident knowledge base and confidence in managing breast imaging emergencies on call.


Assuntos
Doenças Mamárias/diagnóstico por imagem , Competência Clínica , Internato e Residência , Emergências , Feminino , Humanos , Inquéritos e Questionários
9.
Curr Urol Rep ; 18(11): 84, 2017 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-28889366

RESUMO

PURPOSE OF THE REVIEW: Recently introduced Gallium-68 labeled PSMA-ligands such as HBED-CC (68Ga-PSMA) have shown promise for unmet diagnostic needs in prostate cancer. RECENT FINDINGS: 68Ga-PSMA has demonstrated improved detection rates and specificity for prostate cancer compared to standard imaging approaches. In the setting of primary disease, 68Ga-PSMA appears to preferentially identify treatment-relevant intermediate and high-risk prostate cancer. There is also a growing evidence that 68Ga-PSMA positron emission tomography (PET) outperforms alternative conventional imaging methods including choline-based radiotracers for the localization of disease sites at biochemical recurrence, particularly at lower prostate-specific antigen (PSA) levels (< 1 ng/mL). However, the majority of published work lacks rigorous verification of imaging results. 68Ga-PSMA offers significant promise for both, primary disease and biochemically recurrent prostate cancer. The evidence base to support 68Ga-PSMA is however still underdeveloped, and more rigorous studies substantiating efficacy are needed.


Assuntos
Ácido Edético/análogos & derivados , Recidiva Local de Neoplasia/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Neoplasias da Próstata/diagnóstico por imagem , Compostos Radiofarmacêuticos , Humanos , Masculino , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias/métodos , Tomografia por Emissão de Pósitrons/métodos , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/patologia
10.
J Neurosci ; 35(45): 15113-26, 2015 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-26558782

RESUMO

Stroke is the world's leading cause of physiological disability, but there are currently no available agents that can be delivered early after stroke to enhance recovery. Daidzein, a soy isoflavone, is a clinically approved agent that has a neuroprotective effect in vitro, and it promotes axon growth in an animal model of optic nerve crush. The current study investigates the efficacy of daidzein on neuroprotection and functional recovery in a clinically relevant mouse model of stroke recovery. In light of the fact that cholesterols are essential lipid substrates in injury-induced synaptic remodeling, we found that daidzein enhanced the cholesterol homeostasis genetic program, including Lxr and downstream transporters, Apoe, Abca1, and Abcg1 genes in vitro. Daidzein also elevated the cholesterol homeostasis genes in the poststroke brain with Apoe, the highest expressing transporter, but did not affect infarct volume or hemispheric swelling. Despite the absence of neuroprotection, daidzein improved motor/gait function in chronic stroke and elevated synaptophysin expression. However, the daidzein-enhanced functional benefits and synaptophysin expression were abolished in Apoe-knock-out mice, suggesting the importance of daidzein-induced ApoE upregulation in fostering stroke recovery. Dissociation between daidzein-induced functional benefits and the absence of neuroprotection further suggest the presence of nonoverlapping mechanisms underlying recovery processes versus acute pathology. With its known safety in humans, early and chronic use of daidzein aimed at augmenting ApoE may serve as a novel, translatable strategy to promote functional recovery in stroke patients without adverse acute effect. SIGNIFICANCE STATEMENT: There have been recurring translational failures in treatment strategies for stroke. One underlying issue is the disparity in outcome analysis between animal and clinical studies. The former mainly depends on acute infarct size, whereas long-term functional recovery is an important outcome in patients. In an attempt to identify agents that promote functional recovery, we discovered that an FDA-approved soy isoflavone, daidzein, improved stroke-induced behavioral deficits via enhancing cholesterol homeostasis in chronic stroke, and this occurs without causing adverse effects in the acute phase. With its known safety in humans, the study suggests that the early and chronic use of daidzein serves as a potential strategy to promote functional recovery in stroke patients.


Assuntos
Apolipoproteínas E/fisiologia , Colesterol/fisiologia , Homeostase/efeitos dos fármacos , Isoflavonas/uso terapêutico , Recuperação de Função Fisiológica/efeitos dos fármacos , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Apolipoproteínas E/deficiência , Linhagem Celular Tumoral , Células Cultivadas , Doença Crônica , Inibidores do Crescimento/farmacologia , Inibidores do Crescimento/uso terapêutico , Homeostase/fisiologia , Humanos , Isoflavonas/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Recuperação de Função Fisiológica/fisiologia , Acidente Vascular Cerebral/fisiopatologia
11.
Malar J ; 15: 150, 2016 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-26961973

RESUMO

BACKGROUND: The host response to infection by Plasmodium falciparum, the parasite most often responsible for severe malaria, ranges from asymptomatic parasitaemia to death. The clinical trajectory of malaria is influenced by host genetics and parasite load, but the factors determining why some infections produce uncomplicated malaria and some proceed to severe disease remain incompletely understood. METHODS: To identify molecular markers of severe falciparum malaria, human gene expression patterns were compared between children aged 6 months to 5 years with severe and uncomplicated malaria who were enrolled in a case-control study in Bandiagara, Mali. Microarrays were used to obtain expression data on severe cases and uncomplicated controls at the time of acute disease presentation (five uncomplicated and five severe), 1 week after presentation (three uncomplicated and three severe) and treatment initiation, and in the subsequent dry season (late convalescence, four uncomplicated and four severe). This is a pilot study for the first use of microarray technology in Mali. RESULTS: Complement and toll-like receptor (TLR) pathways were differentially expressed, with severe cases showing higher expression of the C1q, TLR2, TLR4, TLR8, and CR1 genes. Other genes previously associated with malaria pathogenesis, GZMB, FOS and HSPA6, were also higher among severe cases. TLR2, TLR4, TLR8, CR1, GZMB, FOS, and HSPA6 genes were expressed at lower levels in severe cases at late convalescence. CONCLUSIONS: Overexpression of genes previously associated with uncomplicated malaria was associated with severe disease. Low baseline expression of these genes may represent candidate markers for severe malaria. Despite the small sample size, results of this pilot study offer promising targets for follow-up analyses.


Assuntos
Proteínas do Sistema Complemento/genética , Malária Falciparum/epidemiologia , Malária Falciparum/genética , Receptores Toll-Like/genética , Biomarcadores/metabolismo , Estudos de Casos e Controles , Pré-Escolar , Análise por Conglomerados , Proteínas do Sistema Complemento/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Lactente , Malária Falciparum/metabolismo , Malária Falciparum/fisiopatologia , Masculino , Mali , Epidemiologia Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Projetos Piloto , Plasmodium falciparum , Receptores Toll-Like/metabolismo
12.
J Infect Dis ; 211(5): 670-9, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25180241

RESUMO

BACKGROUND: The emergence of artemisinin-resistant Plasmodium falciparum in Southeast Asia threatens malaria treatment efficacy. Mutations in a kelch protein encoded on P. falciparum chromosome 13 (K13) have been associated with resistance in vitro and in field samples from Cambodia. METHODS: P. falciparum infections from artesunate efficacy trials in Bangladesh, Cambodia, Laos, Myanmar, and Vietnam were genotyped at 33 716 genome-wide single-nucleotide polymorphisms (SNPs). Linear mixed models were used to test associations between parasite genotypes and parasite clearance half-lives following artesunate treatment. K13 mutations were tested for association with artemisinin resistance, and extended haplotypes on chromosome 13 were examined to determine whether mutations arose focally and spread or whether they emerged independently. RESULTS: The presence of nonreference K13 alleles was associated with prolonged parasite clearance half-life (P = 1.97 × 10(-12)). Parasites with a mutation in any of the K13 kelch domains displayed longer parasite clearance half-lives than parasites with wild-type alleles. Haplotype analysis revealed both population-specific emergence of mutations and independent emergence of the same mutation in different geographic areas. CONCLUSIONS: K13 appears to be a major determinant of artemisinin resistance throughout Southeast Asia. While we found some evidence of spreading resistance, there was no evidence of resistance moving westward from Cambodia into Myanmar.


Assuntos
Antimaláricos/farmacologia , Artemisininas/farmacologia , Resistência a Medicamentos , Malária Falciparum/parasitologia , Mutação , Plasmodium falciparum/efeitos dos fármacos , Sudeste Asiático , Genótipo , Humanos , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Polimorfismo de Nucleotídeo Único , Proteínas de Protozoários/genética
13.
BJU Int ; 116(2): 190-5, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25430505

RESUMO

OBJECTIVE: To prospectively evaluate the effect of transrectal ultrasonography (TRUS)-guided prostate biopsy on erectile and voiding function at multiple time-points after biopsy. PATIENTS AND METHODS: All men who underwent TRUS-guided prostate biopsy completed a five-item version of the International Index of Erectile Function (IIEF-5) and the International Prostate Symptom Score (IPSS) before and at 1, 4 and 12 weeks after TRUS-guided biopsy. Statistical analyses used were a general descriptive analysis, continuous variables using a t-test and categorical data using chi-square analysis. A paired t-test was used to compare each patient's baseline score to their own follow-up survey scores. RESULTS: In all, 220 patients were enrolled with a mean age of 64.1 years and PSA level of 6.7 ng/dL. At initial presentation, 38.6% reported no erectile dysfunction (ED), 22.3% mild ED, 15.5% mild-to-moderate ED, 10% moderate ED, and 13.6% severe ED. On paired t-test there was a statistically significant reduction in IIEF-5 score at 1 week after biopsy compared with before biopsy (18.2 vs 15.5; P < 0.001). This remained significantly reduced at 4 (18.4 vs 17.3; P = 0.008) and 12 weeks (18.4 vs 16.9, P = 0.004) after biopsy. CONCLUSIONS: The effects of TRUS-guided prostate biopsy on erectile function have probably been underestimated. It is important to be aware of these transient effects so patients can be appropriately counselled. The exact cause of this effect is yet to be determined.


Assuntos
Disfunção Erétil/epidemiologia , Disfunção Erétil/etiologia , Biópsia Guiada por Imagem/efeitos adversos , Próstata/patologia , Ultrassonografia de Intervenção/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Biópsia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
14.
Crit Rev Toxicol ; 44(1): 64-82, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24180433

RESUMO

The constitutive androstane receptor (CAR) and pregnane X receptor (PXR) are important nuclear receptors involved in the regulation of cellular responses from exposure to many xenobiotics and various physiological processes. Phenobarbital (PB) is a non-genotoxic indirect CAR activator, which induces cytochrome P450 (CYP) and other xenobiotic metabolizing enzymes and is known to produce liver foci/tumors in mice and rats. From literature data, a mode of action (MOA) for PB-induced rodent liver tumor formation was developed. A MOA for PXR activators was not established owing to a lack of suitable data. The key events in the PB-induced liver tumor MOA comprise activation of CAR followed by altered gene expression specific to CAR activation, increased cell proliferation, formation of altered hepatic foci and ultimately the development of liver tumors. Associative events in the MOA include altered epigenetic changes, induction of hepatic CYP2B enzymes, liver hypertrophy and decreased apoptosis; with inhibition of gap junctional intercellular communication being an associative event or modulating factor. The MOA was evaluated using the modified Bradford Hill criteria for causality and other possible MOAs were excluded. While PB produces liver tumors in rodents, important species differences were identified including a lack of cell proliferation in cultured human hepatocytes. The MOA for PB-induced rodent liver tumor formation was considered to be qualitatively not plausible for humans. This conclusion is supported by data from a number of epidemiological studies conducted in human populations chronically exposed to PB in which there is no clear evidence for increased liver tumor risk.


Assuntos
Neoplasias Hepáticas/patologia , Fígado/efeitos dos fármacos , Fenobarbital/toxicidade , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Hidrocarboneto de Aril Hidroxilases , Proliferação de Células/efeitos dos fármacos , Receptor Constitutivo de Androstano , Citocromo P-450 CYP2B6 , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Fígado/metabolismo , Neoplasias Hepáticas/induzido quimicamente , Receptor de Pregnano X , Receptores de Esteroides/metabolismo , Xenobióticos/toxicidade
15.
J Pediatr Gastroenterol Nutr ; 58(3): 368-75, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24172585

RESUMO

OBJECTIVE: The objective of the present study was to examine whether adolescents' weight perception accuracy (WPA) was associated with extreme weight-management practices (EWPs) in differing body mass index (BMI) categories. METHODS: WPA, overassessment, and underassessment were determined by comparing self-reported BMI and weight perception among U.S. high school students in the 2009 National Youth Risk Behavior Survey. BMI was classified as follows: underweight (<5th percentile), healthy weight (5th to <85th), overweight (≥85th to <95th), and obese (≥95th). WPA was considered inaccurate if BMI and weight perception were discordant. Overassessors thought they were heavier than they were (among underweight/healthy groups); underassessors thought they were lighter than they were (among healthy/overweight/obese groups). EWPs included ≥1 of fasting, use of diet pills, or purging/laxative use. Logit models were fitted for different BMI sex strata. RESULTS: In the final sample of 14,722 US high school students with complete data, 20.2%, 85.7%, 5.8%, and 80.9% of those who were underweight, healthy weight, overweight, and obese, inaccurately assessed their weight, respectively. In turn, 11.4% and 17.6% of accurate and inaccurate assessors engaged in EWPs, respectively. After adjustment, underweight girls who overassessed their weight had 12.6 times higher odds of EWPs (95% confidence interval 3.4-46.6). Moreover, there were elevated odds of EWPs among healthy weight students who overassessed their weight. CONCLUSIONS: Overassessing healthy weight students and underweight girls had higher odds of ≥1 EWPs, likely related to an unhealthy desire to lose weight. The present study demonstrates a need to further educate clinicians on WPA and its relation to EWPs even among those of healthy weight who may be seen as not at risk.


Assuntos
Comportamento do Adolescente , Imagem Corporal , Índice de Massa Corporal , Peso Corporal , Transtornos da Alimentação e da Ingestão de Alimentos/etiologia , Obesidade/psicologia , Percepção de Peso , Adolescente , Catárticos , Jejum , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Feminino , Humanos , Laxantes , Masculino , Sobrepeso , Preparações Farmacêuticas , Valores de Referência , Fatores de Risco , Autorrelato , Estudantes , Magreza/psicologia , Estados Unidos
16.
J Infect Dis ; 208(9): 1514-9, 2013 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23901079

RESUMO

Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) antigens mediate parasite sequestration and host immune evasion. Reactivity to 21 PfEMP1 fragments on a protein microarray was measured in serum samples from Malian children aged 1-6 years and adults. Seroreactivity to PfEMP1 fragments was higher in adults than in children; intracellular conserved fragments were more widely recognized than were extracellular hypervariable fragments. Over a malaria season, children maintained this differential seroreactivity and recognized additional intracellular PfEMP1 fragments. This approach has the potential to identify conserved, seroreactive extracellular PfEMP1 domains critical for protective immunity to malaria.


Assuntos
Antígenos de Protozoários/imunologia , Malária Falciparum/imunologia , Fragmentos de Peptídeos/imunologia , Proteínas de Protozoários/imunologia , Adulto , Anticorpos Antiprotozoários/sangue , Estudos de Casos e Controles , Criança , Pré-Escolar , Humanos , Lactente , Malária Falciparum/sangue , Plasmodium falciparum/imunologia , Análise Serial de Proteínas , Estrutura Terciária de Proteína
18.
PLoS Pathog ; 7(2): e1001296, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21379333

RESUMO

The endosymbiotic bacterium Wolbachia is being investigated as a potential control agent in several important vector insect species. Recent studies have shown that Wolbachia can protect the insect host against a wide variety of pathogens, resulting in reduced transmission of parasites and viruses. It has been proposed that compromised vector competence of Wolbachia-infected insects is due to up-regulation of the host innate immune system or metabolic competition. Anopheles mosquitoes, which transmit human malaria parasites, have never been found to harbor Wolbachia in nature. While transient somatic infections can be established in Anopheles, no stable artificially-transinfected Anopheles line has been developed despite numerous attempts. However, cultured Anopheles cells can be stably infected with multiple Wolbachia strains such as wAlbB from Aedes albopictus, wRi from Drosophila simulans and wMelPop from Drosophila melanogaster. Infected cell lines provide an amenable system to investigate Wolbachia-Anopheles interactions in the absence of an infected mosquito strain. We used Affymetrix GeneChip microarrays to investigate the effect of wAlbB and wRi infection on the transcriptome of cultured Anopheles Sua5B cells, and for a subset of genes used quantitative PCR to validate results in somatically-infected Anopheles mosquitoes. Wolbachia infection had a dramatic strain-specific effect on gene expression in this cell line, with almost 700 genes in total regulated representing a diverse array of functional classes. Very strikingly, infection resulted in a significant down-regulation of many immune, stress and detoxification-related transcripts. This is in stark contrast to the induction of immune genes observed in other insect hosts. We also identified genes that may be potentially involved in Wolbachia-induced reproductive and pathogenic phenotypes. Somatically-infected mosquitoes had similar responses to cultured cells. The data show that Wolbachia has a profound and unique effect on Anopheles gene expression in cultured cells, and has important implications for mechanistic understanding of Wolbachia-induced phenotypes and potential novel strategies to control malaria.


Assuntos
Anopheles/metabolismo , Anopheles/microbiologia , Malária/genética , Malária/microbiologia , Wolbachia/metabolismo , Wolbachia/patogenicidade , Animais , Anopheles/genética , Biomarcadores/metabolismo , Drosophila/genética , Drosophila/microbiologia , Perfilação da Expressão Gênica , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
19.
Addict Biol ; 18(2): 297-306, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23240885

RESUMO

The present study determined the effects of voluntary ethanol drinking and deprivation on basal extracellular glutamate concentrations and clearance in the mesolimbic system and tested the hypothesis that chronic ethanol drinking would persistently increase basal glutamate neurotransmission. Three groups of alcohol-preferring (P) rats were used: 'water group (WG),' 'ethanol maintenance group (MG; 24-hour free choice water versus 15% ethanol)' and 'ethanol deprivation group (DG; 2 weeks of deprivation).' Quantitative microdialysis and Western blots were conducted to measure basal extracellular glutamate concentrations, clearance and proteins associated with glutamate clearance. Chronic alcohol drinking produced a 70-100% increase of basal extracellular glutamate concentrations in the posterior ventral tegmental area (4.0 versus 7.0 µM) and nucleus accumbens shell (3.0 versus 6.0 µM). Glutamate clearances were reduced by 30-40% in both regions of MG rats compared with WG rats. In addition, Western blots revealed a 40-45% decrease of excitatory amino transporter 1 (EAAT1) protein, but no significant changes in the levels of EAAT2 or cystine-glutamate antiporter in these regions of MG versus WG rats. The enhanced glutamate concentrations returned to control levels, accompanied by a recovery of glutamate clearance following deprivation. These results indicated that chronic alcohol drinking enhanced extracellular glutamate concentrations in the mesolimbic system, as a result, in part, of reduced clearance, suggesting that enhanced glutamate neurotransmission may contribute to the maintenance of alcohol drinking. However, because the increased glutamate levels returned to normal after deprivation, elevated glutamate neurotransmission may not contribute to the initiation of relapse drinking.


Assuntos
Consumo de Bebidas Alcoólicas/metabolismo , Etanol/farmacologia , Proteínas de Transporte de Glutamato da Membrana Plasmática/metabolismo , Glutamatos/metabolismo , Núcleo Accumbens/metabolismo , Área Tegmentar Ventral/metabolismo , Sistema y+ de Transporte de Aminoácidos/metabolismo , Análise de Variância , Animais , Western Blotting , Etanol/administração & dosagem , Espaço Extracelular/metabolismo , Feminino , Preferências Alimentares/fisiologia , Cabras , Modelos Lineares , Camundongos , Microdiálise/métodos , Coelhos , Distribuição Aleatória , Ratos , Recidiva , Técnicas Estereotáxicas , Transmissão Sináptica/efeitos dos fármacos
20.
Ann Plast Surg ; 70(4): 392-6, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23486124

RESUMO

INTRODUCTION: A 63-year-old woman underwent face and neck lift with autologous fat transfer-called by her physician a "stem cell face lift." METHODS: Fatty aspirate from her abdominal wall was enriched by hyaluronic acid, triiodothyronine, thyroxine, insulin, dimethylaminoethanol, estriol, dexamethasone, indomethacin, and fibroblast growth factor before injection into the face. RESULTS: At approximately 4-weeks postoperative, the patient developed facial swellings, erythema, necrotizing ulcers, and an orocutaneous fistula. New lesions continued occurring up to 16 weeks after surgery. After multiple surgical debridements and an oral course of rifampin, a decisive reduction in inflammation and healing was observed. Differential diagnosis included (1) mistaken transfer of allogeneic fat (ruled out), (2) toxic impurities in transferred material, (3) microbial contaminant(s) from multiple use liposuction cannula or tissue markers, and (4) endogenous anaerobic orofacial infection (history of previous radiation for tonsillar cancer and dental implants). CONCLUSIONS: The most probable etiology was mycobacterial infection. This is based on a single colony of mycobacterium isolated, histologic finding revealing granulomatous inflammation, and the favorable response to rifampin. The patient underwent subsequent autologous fat transfers, which successfully reduced some disfigurement and scarring.


Assuntos
Tecido Adiposo/transplante , Dermatoses Faciais/etiologia , Dermatoses Faciais/patologia , Infecções por Mycobacterium/etiologia , Infecções por Mycobacterium/patologia , Ritidoplastia/efeitos adversos , Ritidoplastia/métodos , Úlcera Cutânea/etiologia , Úlcera Cutânea/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Necrose
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