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1.
J Infect Dis ; 223(11): 1943-1947, 2021 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-32992328

RESUMEN

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.


Asunto(s)
Anticuerpos Antiprotozoarios/inmunología , Formación de Anticuerpos , Vacunas contra la Malaria , Malaria Falciparum , Adulto , Niño , Epítopos , Humanos , Vacunas contra la Malaria/inmunología , Malaria Falciparum/epidemiología , Malaria Falciparum/prevención & control , Malí , Plasmodium falciparum/inmunología , Proteínas Protozoarias/inmunología , Vacunas de Subunidad/inmunología
2.
Malar J ; 18(1): 273, 2019 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-31409360

RESUMEN

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.


Asunto(s)
Antígenos de Protozoos/inmunología , Malaria Falciparum/inmunología , Plasmodium falciparum/fisiología , Proteínas Protozoarias/inmunología , Adulto , Niño , Preescolar , Secuencia Conservada , Humanos , Lactante , Persona de Mediana Edad , Estructura Terciaria de Proteína , Adulto Joven
3.
AJR Am J Roentgenol ; 212(2): 456-460, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30476458

RESUMEN

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%.


Asunto(s)
Fluorodesoxiglucosa F18 , Enfermedad de Hodgkin/diagnóstico por imagen , Enfermedad de Hodgkin/tratamiento farmacológico , Tomografía de Emisión de Positrones , Radiofármacos , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino , Recurrencia Local de Neoplasia/epidemiología , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Factores de Tiempo , Adulto Joven
4.
Artículo en Inglés | MEDLINE | ID: mdl-30930205

RESUMEN

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.


Asunto(s)
Regulación de la Temperatura Corporal/fisiología , Gadus morhua/crecimiento & desarrollo , Hipoxia , Termotolerancia/fisiología , Animales , Acuicultura , Cambio Climático , Calor
5.
Proteomics ; 18(2)2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29266845

RESUMEN

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.


Asunto(s)
Inmunoensayo/métodos , Inmunoglobulina G/análisis , Malaria Falciparum/diagnóstico , Análisis por Matrices de Proteínas/métodos , Proteoma/análisis , Animales , Aotidae , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Inmunoglobulina A/análisis , Inmunoglobulina M/análisis , Malaria Falciparum/metabolismo , Malaria Falciparum/parasitología , Plasmodium falciparum/aislamiento & purificación , Puntos Cuánticos
6.
AJR Am J Roentgenol ; 210(5): 1088-1091, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29489406

RESUMEN

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.


Asunto(s)
Carcinoma de Células Renales/diagnóstico por imagen , Carcinoma de Células Renales/patología , Neoplasias Renales/diagnóstico por imagen , Neoplasias Renales/patología , Pelvis/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Carcinoma de Células Renales/cirugía , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Renales/cirugía , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico por imagen , Estadificación de Neoplasias , Nefrectomía , Cuidados Posoperatorios , Estudios Retrospectivos
7.
AJR Am J Roentgenol ; 211(4): 896-900, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30106609

RESUMEN

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.


Asunto(s)
Imagen por Resonancia Magnética , Imagen Multimodal , Tomografía de Emisión de Positrones/métodos , Neoplasias del Recto/diagnóstico por imagen , Neoplasias del Recto/patología , Femenino , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Retrospectivos , Imagen de Cuerpo Entero
8.
Emerg Radiol ; 25(4): 375-380, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29502287

RESUMEN

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.


Asunto(s)
Enfermedades de la Mama/diagnóstico por imagen , Competencia Clínica , Internado y Residencia , Urgencias Médicas , Femenino , Humanos , Encuestas y Cuestionarios
9.
Curr Urol Rep ; 18(11): 84, 2017 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-28889366

RESUMEN

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.


Asunto(s)
Ácido Edético/análogos & derivados , Recurrencia Local de Neoplasia/diagnóstico por imagen , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Neoplasias de la Próstata/diagnóstico por imagen , Radiofármacos , Humanos , Masculino , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias/métodos , Tomografía de Emisión de Positrones/métodos , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/patología
10.
J Neurosci ; 35(45): 15113-26, 2015 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-26558782

RESUMEN

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.


Asunto(s)
Apolipoproteínas E/fisiología , Colesterol/fisiología , Homeostasis/efectos de los fármacos , Isoflavonas/uso terapéutico , Recuperación de la Función/efectos de los fármacos , Accidente Cerebrovascular/tratamiento farmacológico , Animales , Apolipoproteínas E/deficiencia , Línea Celular Tumoral , Células Cultivadas , Enfermedad Crónica , Inhibidores de Crecimiento/farmacología , Inhibidores de Crecimiento/uso terapéutico , Homeostasis/fisiología , Humanos , Isoflavonas/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Recuperación de la Función/fisiología , Accidente Cerebrovascular/fisiopatología
11.
Malar J ; 15: 150, 2016 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-26961973

RESUMEN

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.


Asunto(s)
Proteínas del Sistema Complemento/genética , Malaria Falciparum/epidemiología , Malaria Falciparum/genética , Receptores Toll-Like/genética , Biomarcadores/metabolismo , Estudios de Casos y Controles , Preescolar , Análisis por Conglomerados , Proteínas del Sistema Complemento/metabolismo , Femenino , Perfilación de la Expresión Génica , Humanos , Lactante , Malaria Falciparum/metabolismo , Malaria Falciparum/fisiopatología , Masculino , Malí , Epidemiología Molecular , Análisis de Secuencia por Matrices de Oligonucleótidos , Proyectos Piloto , Plasmodium falciparum , Receptores Toll-Like/metabolismo
12.
J Infect Dis ; 211(5): 670-9, 2015 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-25180241

RESUMEN

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.


Asunto(s)
Antimaláricos/farmacología , Artemisininas/farmacología , Resistencia a Medicamentos , Malaria Falciparum/parasitología , Mutación , Plasmodium falciparum/efectos de los fármacos , Asia Sudoriental , Genotipo , Humanos , Plasmodium falciparum/genética , Plasmodium falciparum/aislamiento & purificación , Polimorfismo de Nucleótido Simple , Proteínas Protozoarias/genética
13.
BJU Int ; 116(2): 190-5, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25430505

RESUMEN

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.


Asunto(s)
Disfunción Eréctil/epidemiología , Disfunción Eréctil/etiología , Biopsia Guiada por Imagen/efectos adversos , Próstata/patología , Ultrasonografía Intervencional/efectos adversos , Anciano , Anciano de 80 o más Años , Biopsia , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
14.
Crit Rev Toxicol ; 44(1): 64-82, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24180433

RESUMEN

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.


Asunto(s)
Neoplasias Hepáticas/patología , Hígado/efectos de los fármacos , Fenobarbital/toxicidad , Receptores Citoplasmáticos y Nucleares/metabolismo , Animales , Hidrocarburo de Aril Hidroxilasas , Proliferación Celular/efectos de los fármacos , Receptor de Androstano Constitutivo , Citocromo P-450 CYP2B6 , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Hígado/metabolismo , Neoplasias Hepáticas/inducido químicamente , Receptor X de Pregnano , Receptores de Esteroides/metabolismo , Xenobióticos/toxicidad
15.
J Pediatr Gastroenterol Nutr ; 58(3): 368-75, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24172585

RESUMEN

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.


Asunto(s)
Conducta del Adolescente , Imagen Corporal , Índice de Masa Corporal , Peso Corporal , Trastornos de Alimentación y de la Ingestión de Alimentos/etiología , Obesidad/psicología , Percepción del Peso , Adolescente , Catárticos , Ayuno , Trastornos de Alimentación y de la Ingestión de Alimentos/psicología , Femenino , Humanos , Laxativos , Masculino , Sobrepeso , Preparaciones Farmacéuticas , Valores de Referencia , Factores de Riesgo , Autoinforme , Estudiantes , Delgadez/psicología , Estados Unidos
16.
J Infect Dis ; 208(9): 1514-9, 2013 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-23901079

RESUMEN

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.


Asunto(s)
Antígenos de Protozoos/inmunología , Malaria Falciparum/inmunología , Fragmentos de Péptidos/inmunología , Proteínas Protozoarias/inmunología , Adulto , Anticuerpos Antiprotozoarios/sangre , Estudios de Casos y Controles , Niño , Preescolar , Humanos , Lactante , Malaria Falciparum/sangre , Plasmodium falciparum/inmunología , Análisis por Matrices de Proteínas , Estructura Terciaria de Proteína
17.
J Infect ; 89(4): 106257, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39216830

RESUMEN

Children with hemoglobin AC or AS have decreased susceptibility to clinical malaria. Parasite variant surface antigen (VSA) presentation on the surface of infected erythrocytes is altered in erythrocytes with hemoglobin C (Hb AC) or sickle trait (Hb AS) mutations in vitro. The protective role of incomplete or altered VSA presentation against clinical malaria in individuals with Hb AC or AS is unclear. Using a high-throughput protein microarray, we sought to use serological responses to VSAs as a measure of host exposure to VSAs among Malian children with Hb AC, Hb AS, or wildtype hemoglobin (Hb AA). In uncomplicated malaria, when compared to Hb AA children, Hb AC children had significantly lower serological responses to extracellular Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP1) domains but did not differ in responses to intracellular PfEMP1 domains and other VSAs, including members of the repetitive interspersed family (RIFIN) and subtelomeric variable open reading frame (STEVOR) family. Healthy children with Hb AC and Hb AS genotypes recognized fewer extracellular PfEMP1s compared to children with Hb AA, especially CD36-binding PfEMP1s. These reduced serologic responses may reflect reduced VSA presentation or lower parasite exposure in children with Hb AC or AS and provide insights into mechanisms of protection.


Asunto(s)
Antígenos de Protozoos , Hemoglobina C , Malaria Falciparum , Plasmodium falciparum , Proteínas Protozoarias , Rasgo Drepanocítico , Humanos , Antígenos de Protozoos/inmunología , Antígenos de Protozoos/genética , Preescolar , Niño , Plasmodium falciparum/inmunología , Plasmodium falciparum/genética , Proteínas Protozoarias/genética , Proteínas Protozoarias/inmunología , Hemoglobina C/genética , Malaria Falciparum/inmunología , Malaria Falciparum/sangre , Rasgo Drepanocítico/genética , Rasgo Drepanocítico/sangre , Rasgo Drepanocítico/inmunología , Masculino , Femenino , Anticuerpos Antiprotozoarios/sangre , Anticuerpos Antiprotozoarios/inmunología , Hemoglobina Falciforme/genética , Malí/epidemiología , Lactante , Antígenos de Superficie/inmunología , Antígenos de Superficie/genética , Análisis por Matrices de Proteínas , Adolescente
18.
J Clin Med ; 13(13)2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38999481

RESUMEN

This review explores the concept of futility timeouts and the use of traumatic brain injury (TBI) as an independent predictor of the futility of resuscitation efforts in severely bleeding trauma patients. The national blood supply shortage has been exacerbated by the lingering influence of the COVID-19 pandemic on the number of blood donors available, as well as by the adoption of balanced hemostatic resuscitation protocols (such as the increasing use of 1:1:1 packed red blood cells, plasma, and platelets) with and without early whole blood resuscitation. This has underscored the urgent need for reliable predictors of futile resuscitation (FR). As a result, clinical, radiologic, and laboratory bedside markers have emerged which can accurately predict FR in patients with severe trauma-induced hemorrhage, such as the Suspension of Transfusion and Other Procedures (STOP) criteria. However, the STOP criteria do not include markers for TBI severity or transfusion cut points despite these patients requiring large quantities of blood components in the STOP criteria validation cohort. Yet, guidelines for neuroprognosticating patients with TBI can require up to 72 h, which makes them less useful in the minutes and hours following initial presentation. We examine the impact of TBI on bleeding trauma patients, with a focus on those with coagulopathies associated with TBI. This review categorizes TBI into isolated TBI (iTBI), hemorrhagic isolated TBI (hiTBI), and polytraumatic TBI (ptTBI). Through an analysis of bedside parameters (such as the proposed STOP criteria), coagulation assays, markers for TBI severity, and transfusion cut points as markers of futilty, we suggest amendments to current guidelines and the development of more precise algorithms that incorporate prognostic indicators of severe TBI as an independent parameter for the early prediction of FR so as to optimize blood product allocation.

20.
PLoS Pathog ; 7(2): e1001296, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21379333

RESUMEN

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.


Asunto(s)
Anopheles/metabolismo , Anopheles/microbiología , Malaria/genética , Malaria/microbiología , Wolbachia/metabolismo , Wolbachia/patogenicidad , Animales , Anopheles/genética , Biomarcadores/metabolismo , Drosophila/genética , Drosophila/microbiología , Perfilación de la Expresión Génica , Humanos , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
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