RESUMO
Cucurbit downy mildew caused by the obligate oomycete, Pseudoperonospora cubensis, is considered one of the most economically important diseases of cucurbits worldwide. In the continental United States, the pathogen overwinters in southern Florida and along the coast of the Gulf of Mexico. Outbreaks of the disease in northern states occur annually via long-distance aerial transport of sporangia from infected source fields. An integrated aerobiological modeling system has been developed to predict the risk of disease occurrence and to facilitate timely use of fungicides for disease management. The forecasting system, which combines information on known inoculum sources, long-distance atmospheric spore transport and spore deposition modules, was tested to determine its accuracy in predicting risk of disease outbreak. Rainwater samples at disease monitoring sites in Alabama, Georgia, Louisiana, New York, North Carolina, Ohio, Pennsylvania and South Carolina were collected weekly from planting to the first appearance of symptoms at the field sites during the 2013, 2014, and 2015 growing seasons. A conventional PCR assay with primers specific to P. cubensis was used to detect the presence of sporangia in rain water samples. Disease forecasts were monitored and recorded for each site after each rain event until initial disease symptoms appeared. The pathogen was detected in 38 of the 187 rainwater samples collected during the study period. The forecasting system correctly predicted the risk of disease outbreak based on the presence of sporangia or appearance of initial disease symptoms with an overall accuracy rate of 66 and 75%, respectively. In addition, the probability that the forecasting system correctly classified the presence or absence of disease was ≥ 73%. The true skill statistic calculated based on the appearance of disease symptoms in cucurbit field plantings ranged from 0.42 to 0.58, indicating that the disease forecasting system had an acceptable to good performance in predicting the risk of cucurbit downy mildew outbreak in the eastern United States.
Assuntos
Modelos Teóricos , Micoses , Oomicetos , Doenças das Plantas , Chuva/microbiologia , Cucurbitaceae , Previsões , Risco , Estados UnidosRESUMO
Chemical control is currently the most effective method for controlling cucurbit downy mildew (CDM) caused by Pseudoperonospora cubensis. Most commercial cucurbit cultivars, with the exception of a few new cucumber cultivars, lack adequate disease resistance. Fluopicolide and propamocarb were among the most effective fungicides against CDM in the United States between 2006 and 2009. Since then, reduced efficacy of these two fungicides under field conditions was reported starting around 2013 but occurrence of resistance to fluopicolide and propamocarb in field isolates of P. cubensis had not been established. Thirty-one isolates collected from cucurbits in the eastern United States were tested for their sensitivity to fluopicolide and propamocarb using a leaf disc assay. This same set of isolates and four additional isolates (i.e., 35 isolates) were also used to establish the baseline sensitivity of P. cubensis to ethaboxam, an ethylamino-thiazole-carboxamide fungicide, which was recently granted registration to control CDM in the United States. About 65% of the isolates tested were resistant to fluopicolide with at least one resistant isolate being present in samples collected from 12 of the 13 states in the eastern United States. About 74% of the isolates tested were sensitive to propamocarb with at least one resistant isolate being among samples collected from 8 of the 12 states in the study. The frequency of resistance to fluopicolide and propamocarb was high among isolates collected from cucumber, while the frequency was low among isolates collected from other cucurbit host types. All isolates tested were found to be sensitive to ethaboxam and EC50 values ranged from 0.18 to 3.08 mg a.i./liter with a median of 1.55 mg a.i./liter. The ratio of EC50 values for the least sensitive and the most sensitive isolate was 17.1, indicating that P. cubensis isolates were highly sensitive to ethaboxam. The most sensitive isolates to ethaboxam were collected from New York, North Carolina, and Ohio, while the least sensitive isolates were collected from Georgia, Michigan, and New Jersey. These results show that ethaboxam could be a viable addition to fungicide programs used to control CDM in the United States.
Assuntos
Benzamidas/farmacologia , Carbamatos/farmacologia , Farmacorresistência Fúngica/efeitos dos fármacos , Oomicetos/efeitos dos fármacos , Tiazóis/farmacologia , Tiofenos/farmacologia , Cucurbitaceae/microbiologia , Fungicidas Industriais/farmacologia , Georgia , Michigan , Testes de Sensibilidade Microbiana , New Jersey , New York , North Carolina , Ohio , Oomicetos/classificação , Oomicetos/fisiologia , Doenças das Plantas/microbiologia , Especificidade da EspécieRESUMO
BACKGROUND: Delirium is common after surgery, although the aetiology is poorly defined. Brain-derived neurotrophic factor (BDNF) is a neurotrophin important in neurotransmission and neuroplasticity. Decreased levels of BDNF have been associated with poor cognitive outcomes, but few studies have characterized the role of BDNF perioperatively. We hypothesized that intraoperative decreases in BDNF levels are associated with postoperative delirium. METHODS: Patients undergoing spine surgery were enrolled in a prospective cohort study. Plasma BDNF was collected at baseline and at least hourly intraoperatively. Delirium was assessed using rigorous methods, including the Confusion Assessment Method (CAM) and CAM for the intensive care unit. Associations of changes in BDNF and delirium were examined using regression models. RESULTS: Postoperative delirium developed in 32 of 77 (42%) patients. The median baseline BDNF level was 7.6 ng ml -1 [interquartile range (IQR) 3.0-11.2] and generally declined intraoperatively [median decline 61% (IQR 31-80)]. There was no difference in baseline BDNF levels by delirium status. However, the percent decline in BDNF was greater in patients who developed delirium [median 74% (IQR 51-82)] vs in those who did not develop delirium [median 50% (IQR 14-79); P =0.03]. Each 1% decline in BDNF was associated with increased odds of delirium in unadjusted {odds ratio [OR] 1.02 [95% confidence interval (CI) 1.00-1.04]; P =0.01}, multivariable-adjusted [OR 1.02 (95% CI 1.00-1.03); P =0.03], and propensity score-adjusted models [OR 1.02 (95% CI 1.00-1.04); P =0.03]. CONCLUSIONS: We observed an association between intraoperative decline in plasma BDNF and delirium. These preliminary results need to be confirmed but suggest that plasma BDNF levels may be a biomarker for postoperative delirium.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/sangue , Delírio/etiologia , Complicações Pós-Operatórias/etiologia , Idoso , Idoso de 80 Anos ou mais , Delírio/sangue , Feminino , Humanos , Período Intraoperatório , Masculino , Complicações Pós-Operatórias/sangue , Estudos ProspectivosRESUMO
BACKGROUND: Mean arterial pressure (MAP) below the lower limit of cerebral autoregulation during cardiopulmonary bypass (CPB) is associated with complications after cardiac surgery. However, simply raising empiric MAP targets during CPB might result in MAP above the upper limit of autoregulation (ULA), causing cerebral hyperperfusion in some patients and predisposing them to cerebral dysfunction after surgery. We hypothesized that MAP above an ULA during CPB is associated with postoperative delirium. METHODS: Autoregulation during CPB was monitored continuously in 491 patients with the cerebral oximetry index (COx) in this prospective observational study. COx represents Pearson's correlation coefficient between low-frequency changes in regional cerebral oxygen saturation (measured with near-infrared spectroscopy) and MAP. Delirium was defined throughout the postoperative hospitalization based on clinical detection with prospectively defined methods. RESULTS: Delirium was observed in 45 (9.2%) patients. Mechanical ventilation for >48 h [odds ratio (OR), 3.94; 95% confidence interval (CI), 1.72-9.03], preoperative antidepressant use (OR, 3.0; 95% CI, 1.29-6.96), prior stroke (OR, 2.79; 95% CI, 1.12-6.96), congestive heart failure (OR, 2.68; 95% CI, 1.28-5.62), the product of the magnitude and duration of MAP above an ULA (mm Hg h; OR, 1.09; 95% CI, 1.03-1.15), and age (per year of age; OR, 1.01; 95% CI, 1.01-1.07) were independently associated with postoperative delirium. CONCLUSIONS: Excursions of MAP above the upper limit of cerebral autoregulation during CPB are associated with risk for delirium. Optimizing MAP during CPB to remain within the cerebral autoregulation range might reduce risk of delirium. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov NCT00769691 and NCT00981474.
Assuntos
Ponte Cardiopulmonar/efeitos adversos , Circulação Cerebrovascular/fisiologia , Delírio/etiologia , Homeostase/fisiologia , Idoso , Pressão Arterial/fisiologia , Delírio/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Intraoperatória/métodos , Assistência Perioperatória/métodos , Estudos Prospectivos , Fatores de Risco , Espectroscopia de Luz Próxima ao Infravermelho/métodosRESUMO
BACKGROUND: Postoperative delirium in the elderly is common and associated with poor outcomes, but often goes unrecognized. Delirium screening tools, validated in postoperative settings are lacking. This study compares two screening tools [Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) and Nursing Delirium Symptom Checklist (NuDESC)] with a DSM-IV-based diagnosis of delirium, conducted by neuropsychiatric examination in postoperative settings. METHODS: Consecutive English-speaking patients, ≥70 yr, undergoing surgery with general anaesthesia and capable of providing informed consent, were recruited. Diagnostic test characteristics were compared for each screening tool vs neuropsychiatric examination, both in the Post-Anaesthesia Care Unit (PACU), and daily during inpatient hospitalization, adjusting for repeated measures. RESULTS: Neuropsychiatric examination identified delirium in 45% of 91 patients evaluated in the PACU and in 32% of 166 subsequent delirium assessments on the ward in the 58 admitted patients. The sensitivity [95% confidence interval (CI)] of delirium detection of the CAM-ICU in the PACU, and in all repeated assessments was 28% (16-45%) and 28% (17-42%), respectively; for the NuDESC (scoring threshold ≥2), 32% (19-48%) and 29% (19-42%), respectively, and the NuDESC (threshold ≥1), 80% (65-91%) and 72% (60-82%), respectively. Specificity was >90% for both the CAM-ICU and the NuDESC (threshold ≥2); specificity for the NuDESC (threshold ≥1), in the PACU was 69% (54-80%) and 80% (73-85%) for all assessments. CONCLUSIONS: While highly specific, neither CAM-ICU nor NuDESC (threshold ≥2) are adequately sensitive to identify delirium post-operatively; NuDESC (threshold ≥1) increases sensitivity, but reduces specificity.
Assuntos
Delírio/diagnóstico , Programas de Rastreamento/métodos , Complicações Pós-Operatórias/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Anestesia Geral , Lista de Checagem , Cuidados Críticos/métodos , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Cuidados Pós-Operatórios/métodos , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Sensibilidade e EspecificidadeRESUMO
Schizophrenia is a common disorder characterized by psychotic symptoms; diagnostic criteria have been established. Family, twin and adoption studies suggest that both genetic and environmental factors influence susceptibility (heritability is approximately 71%; ref. 2), however, little is known about the aetiology of schizophrenia. Clinical and family studies suggest aetiological heterogeneity. Previously, we reported that regions on chromosomes 22, 3 and 8 may be associated with susceptibility to schizophrenia, and collaborations provided some support for regions on chromosomes 8 and 22 (refs 9-13). We present here a genome-wide scan for schizophrenia susceptibility loci (SSL) using 452 microsatellite markers on 54 multiplex pedigrees. Non-parametric linkage (NPL) analysis provided significant evidence for an SSL on chromosome 13q32 (NPL score=4.18; P=0.00002), and suggestive evidence for another SSL on chromosome 8p21-22 (NPL=3.64; P=0.0001). Parametric linkage analysis provided additional support for these SSL. Linkage evidence at chromosome 8 is weaker than that at chromosome 13, so it is more probable that chromosome 8 may be a false positive linkage. Additional putative SSL were noted on chromosomes 14q13 (NPL=2.57; P=0.005), 7q11 (NPL=2.50, P=0.007) and 22q11 (NPL=2.42, P=0.009). Verification of suggestive SSL on chromosomes 13q and 8p was attempted in a follow-up sample of 51 multiplex pedigrees. This analysis confirmed the SSL in 13q14-q33 (NPL=2.36, P=0.007) and supported the SSL in 8p22-p21 (NPL=1.95, P=0.023).
Assuntos
Cromossomos Humanos Par 13 , Cromossomos Humanos Par 8 , Esquizofrenia/genética , Adulto , Suscetibilidade a Doenças , Feminino , Genes Dominantes , Ligação Genética , Humanos , Escore Lod , Masculino , Repetições de Microssatélites , Modelos GenéticosRESUMO
Outbreaks of cucurbit downy mildew caused by Pseudoperonospora cubensis are dependent on the weather but effects of temperature and leaf wetness duration on infection have not been studied for different cucurbits. To determine the effects of these two weather variables on sporangia germination and infection of cucurbit host types by P. cubensis, three host types; cucumber ('Straight 8'), cantaloupe ('Kermit'), and acorn squash ('Table Queen'), were inoculated and exposed to leaf wetness durations of 2 to 24 h at six constant temperatures ranging from 5 to 30°C in growth-chamber experiments. Sporangia germination was assessed after each wetness period, and leaf area infected was assessed 5 and 7 days after inoculation. Germination of sporangia was highest on cantaloupe (16.5 to 85.7%) and lowest on squash (10.7 to 68.9%), while disease severity was highest and lowest on cucumber and cantaloupe, respectively. Host type, temperature, wetness duration and their interactions significantly (P < 0.0001) affected germination and disease severity. Germination and disease data for each host type were separately fitted to a modified form of a Weibull function that characterizes a unimodal response and monotonic increase of germination or infection with temperature and wetness duration, respectively. The effect of host type on germination and infection was characterized primarily by differences in the upper limit parameter in response to temperature. Differences among host types based on other parameters were either small or inconsistent. Temperature and wetness duration that supported a given level of germination or infection varied among host types. At 20°C, 15% leaf area infected was expected following 2, 4, and 8 h of wetness for cucumber, squash, and cantaloupe, respectively. When temperature was increased to 25°C, 15% disease severity was expected following 3, 7, and 15 h of wetness for cucumber, squash, and cantaloupe, respectively. Risk charts were constructed to estimate the potential risk of infection of cucurbit host types by P. cubensis based on prevailing or forecasted temperature and leaf wetness duration. These results will improve the timing and application of the initial fungicide spray for the control of cucurbit downy mildew.
RESUMO
The influence of temperature and leaf wetness duration on germination of sporangia and infection of cantaloupe leaves by Pseudoperonospora cubensis was examined in three independent controlled-environment experiments by inoculating plants with a spore suspension and exposing them to a range of leaf wetness durations (2 to 24 h) at six fixed temperatures (5 to 30 degrees C). Germination of sporangia was assessed at the end of each wetness period and infection was evaluated from assessments of disease severity 5 days after inoculation. Three response surface models based on modified forms of the Weibull function were evaluated for their ability to describe germination of sporangia and infection in response to temperature and leaf wetness duration. The models estimated 15.7 to 17.3 and 19.5 to 21.7 degrees C as the optimum temperature (t) range for germination and infection, respectively, with little germination or infection at 5 or 30 degrees C. For wetness periods of 4 to 8 h, a distinct optimum for infection was observed at t = 20 degrees C but broader optimum curves resulted from wetness periods >8 h. Model 1 of the form f(w,t) = f(t) x (1 - exp{-[B x w](D)}) resulted in smaller asymptotic standard errors and yielded higher correlations between observed and predicted germination and infection data than either model 2 of the form f(w,t) = A{1 - exp[- f(t) x (w - C)](D)} or model 3 of the form f(w,t) = [1 - exp{-(B x w)(2)}]/cosh[(t - F)G/2]. Models 1 and 2 had nonsignificant lack-of-fit test statistics for both germination and infection data, whereas a lack-of-fit test was significant for model 3. The models accounted for approximately 87% (model 3) to 98% (model 1) of the total variation in the germination and infection data. In the validation of the models using data generated with a different isolate of P. cubensis, slopes of the regression line between observed and predicted germination and infection data were not significantly different (P > 0.2487) and correlation coefficients between observed and predicted values were high (r(2) > 0.81). Models 1 and 2 were used to construct risk threshold charts that can be used to estimate the potential risk for infection based on observed or forecasted temperature and leaf wetness duration.
Assuntos
Cucumis melo/microbiologia , Oomicetos/fisiologia , Doenças das Plantas/microbiologia , Temperatura , Água , Esporos/fisiologia , Fatores de TempoRESUMO
This study investigated the hypothesis that dietary supplementation of lignocellulose in broilers influences the gut bacterial population and bacterial fermentation, has anti-inflammatory effects, and increases mucin synthesis in the intestine, and, through these changes, influences broiler performance positively. Day-old male Cobb 500 broilers (n = 96) were allotted to 3 experimental groups and fed 3 different maize-wheat-soybean meal-based basal diets during days 1 to 10, 11 to 21, and 22 to 35. The basal diets were fed to the control group, and were supplemented with 0.8% of a standard lignocellulose (LCS) or a fermentable lignocellulose (LCF). Body weight and feed consumption were determined, and at slaughter (day 35), carcass and gizzard weights and gizzard content pH were recorded, and samples of jejunum, cecum, and colon mucosa and of cecum digesta were collected from 15 birds/group. Growth performance and feed intake were not influenced, but dressing percentage was higher in group LCF compared to the other groups. In group LCS and the control group, performance, gizzard weight and gizzard content pH, intestinal gene expression of pro-inflammatory cytokines and of the mucins 2, 5ac and 13, the cecal short-chain fatty acid (SCFA) profile, and bacterial diversity were similar, and relative abundance of bacterial groups (16S DNA sequencing) differed. Supplementation of LCF decreased the expression of the pro-inflammatory genes encoding interleukins 1ß and 17 (P < 0.05) and those of 2 and 8 (P < 0.10) in the jejunum only. The bacterial population differed, and the SCFA profile shifted toward acetate at the expense of butyrate in group LCF compared to the control group. For example, the abundance of Firmicutes and of Ruminococcaceae and Lactobacillaceae decreased, whereas those of Peptostreptococcaceae, Erysipelotrichaceae, and Enterobacteriaceae and that of members of the phylum Proteobacteria increased in group LCF compared to the control group. These data indicate that the susceptibility of lignocellulose to fermentation is crucial for mediating its effects on intestinal gene expression and the bacterial population in the cecum, which may also affect dressing percentage.
Assuntos
Ração Animal/análise , Galinhas/microbiologia , Microbioma Gastrointestinal , Lignina/química , Animais , Galinhas/metabolismo , Citocinas/genética , Citocinas/metabolismo , Dieta/veterinária , Ácidos Graxos Voláteis/análise , Fermentação , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia , Expressão Gênica , Lignina/metabolismo , Masculino , Mucinas/genética , Mucinas/metabolismoRESUMO
This work shows that calcareous benthic foraminifera are capable of agglutinating sedimentary particles also. In particular, we focus on Melonis barleeanus. Traditionally considered a calcareous species, our data revealed the presence of minute (~3 µm) sedimentary particles (silicate grains) inside the chamber walls of the examined shells. These particles were arranged in a definitive and systematic pattern, and the similar grain chemical characterization and size suggested a relatively high degree of selectivity in both modern and fossil specimens. Based on these results, we propose that M. barleeanus is capable of agglutinating sedimentary particles during the formation of a new chamber. The analysis of other calcareous foraminiferal species (e.g., Cassidulina neoteretis, Lobatula lobatula, Nonionella stella) did not reveal the presence of silicate grains in the shell of the specimens analyzed confirming this to be a characteristic of M. barleeanus. Considering that the isotopic and chemical composition of this species is widely used in paleoclimatic and paleoceanographic reconstructions, we used a mixing model to better constrain the influence of sedimentary particles on M. barleeanus δ18O data. Our model showed that the calcite δ18O would increase by ~0.9-2 if 10 wt% of feldspars (i.e., anorthite, albite, orthoclase) and quartz, respectively, were included in the analyzed shell. Based on these results, we emphasize that it is of paramount importance to consider M. barleeanus unusual biomineralization strategy during the interpretation of geological records and to investigate the presence of similar processes in other calcareous foraminiferal species.
Assuntos
Foraminíferos/metabolismo , Sedimentos Geológicos/química , Silicatos/metabolismo , Exoesqueleto/metabolismo , Animais , Biomineralização , FósseisRESUMO
Loss of functional adenomatous polyposis coli protein (APC) leads to uncontrolled proliferation of colonic epithelial cells, as evidenced by polyp formation, a prelude to carcinogenesis. As a tumor suppressor, APC targets the oncogene beta-catenin for proteasome-mediated cytoplasmic degradation. Recently, it was demonstrated that APC also interacts with nuclear beta-catenin, thereby reducing beta-catenin's activity as a transcription cofactor and enhancing its nuclear export. The first objective of this study was to analyze how cellular context affected APC distribution. We determined that cell density but not cell cycle influenced APC's subcellular distribution, with predominantly nuclear APC found in subconfluent MDCK and intestinal epithelial cells but both cytoplasmic and nuclear APC in superconfluent cells. Redistribution of APC protein did not depend on continual nuclear export. Focusing on the two defined nuclear localization signals in the C-terminal third of APC (NLS1(APC) and NLS2(APC)), we found that phosphorylation at the CK2 site increased and phosphorylation at the PKA site decreased NLS2(APC)-mediated nuclear translocation. Cell density-mediated redistribution of beta-galactosidase was achieved by fusion to NLS2(APC) but not to NLS1(APC). Both the CK2 and PKA sites were important for this density-mediated redistribution, and pharmacological agents that target CK2 and PKA instigated relocalization of endogenous APC. Our data provide evidence that physiological signals such as cell density regulate APC's nuclear distribution, with phosphorylation sites near NLS2(APC) being critical for this regulation.
Assuntos
Proteína da Polipose Adenomatosa do Colo/metabolismo , Líquido Intracelular/metabolismo , Receptores Citoplasmáticos e Nucleares , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Transporte Ativo do Núcleo Celular/fisiologia , Proteína da Polipose Adenomatosa do Colo/genética , Animais , Contagem de Células , Ciclo Celular/fisiologia , Linhagem Celular , Cães , Inibidores Enzimáticos/farmacologia , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Genes Reporter , Mucosa Intestinal/citologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Carioferinas/metabolismo , Rim/citologia , Rim/efeitos dos fármacos , Rim/metabolismo , Células L , Camundongos , Sinais de Localização Nuclear/metabolismo , Sinais de Localização Nuclear/farmacologia , Fosforilação/efeitos dos fármacos , Ratos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais/fisiologia , Transfecção , Proteína Exportina 1RESUMO
BACKGROUND: Environmental stress affects the gut with dysmotility being a common consequence. Although a variety of microbes or molecules may prevent the dysmotility, none reverse the dysmotility. METHODS: We have used a 1 hour restraint stress mouse model to test for treatment effects of the neuroactive microbe, L. rhamnosus JB-1™ . Motility of fluid-filled ex vivo gut segments in a perfusion organ bath was recorded by video and migrating motor complexes measured using spatiotemporal maps of diameter changes. KEY RESULTS: Stress reduced jejunal and increased colonic propagating contractile cluster velocities and frequencies, while increasing contraction amplitudes for both. Luminal application of 10E8 cfu/mL JB-1 restored motor complex variables to unstressed levels within minutes of application. L. salivarius or Na.acetate had no treatment effects, while Na.butyrate partially reversed stress effects on colonic frequency and amplitude. Na.propionate reversed the stress effects for jejunum and colon except on jejunal amplitude. CONCLUSIONS & INFERENCES: Our findings demonstrate, for the first time, a potential for certain beneficial microbes as treatment of stress-induced intestinal dysmotility and that the mechanism for restoration of function occurs within the intestine via a rapid drug-like action on the enteric nervous system.
Assuntos
Motilidade Gastrointestinal/fisiologia , Lacticaseibacillus rhamnosus , Probióticos/administração & dosagem , Estresse Psicológico/dietoterapia , Estresse Psicológico/fisiopatologia , Animais , Gastroenteropatias/dietoterapia , Gastroenteropatias/fisiopatologia , Motilidade Gastrointestinal/efeitos dos fármacos , Masculino , Camundongos , Complexo Mioelétrico Migratório/efeitos dos fármacos , Complexo Mioelétrico Migratório/fisiologia , Técnicas de Cultura de Órgãos , Restrição Física/efeitos adversosRESUMO
Transforming growth factor-beta (TGF-beta) protects normal cells from etoposide-induced cell death, yet the mechanism has remained speculative. Studies have shown that etoposide modifies the activity of the topoisomerase IIalpha (topo IIalpha) enzyme, thereby causing DNA damage and inducing cell death. Expression of topo IIalpha is necessary for etoposide-induced cell death, and peak expression of topo IIalpha normally occurs during the G2 phase of the cell cycle. We predicted that by arresting growth in the G1 phase, TGF-beta1 would prevent the induction of topo IIalpha expression that normally occurs subsequent to the G1-S transition, thereby protecting cells from etoposide-induced cell death. Accordingly, we hypothesized that the inhibition of topo IIalpha expression by TGF-beta1 would be dependent on the ability of TGF-beta1 to arrest cell cycle progression in G1. Using mink lung epithelial cells (MvlLu), we found that TGF-beta1 decreases topo IIalpha mRNA expression, and the decrease occurs as cells begin to accumulate in the G1 phase of the cell cycle. Topo IIalpha protein expression decreases subsequent to the fall in mRNA expression. In contrast, topo IIalpha expression is not affected by TGF-beta1 in cells that fail to undergo G1 arrest because of inactivation of the retinoblastoma tumor suppressor protein (pRb) by the papillomavirus type 16 E7 protein. Our studies suggest that inhibition of topo IIalpha by TGF-beta1 is the principal mechanism that protects mink lung epithelial cells (Mv1Lu) from etoposide-induced toxicity. Furthermore, the inhibition of topo IIalpha protein expression by TGF-beta1 is dependent on pRb-mediated cell cycle arrest, suggesting that TGF-beta1 will not reduce the sensitivity of pRb-deficient cancers to etoposide.
Assuntos
DNA Topoisomerases Tipo II , Isoenzimas/antagonistas & inibidores , Proteínas Oncogênicas Virais/farmacologia , Inibidores da Topoisomerase II , Fator de Crescimento Transformador beta/farmacologia , Animais , Antígenos de Neoplasias , Antineoplásicos Fitogênicos/farmacologia , Northern Blotting , Western Blotting , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular , Separação Celular , Proteínas de Ligação a DNA , Etoposídeo/farmacologia , Citometria de Fluxo , Fase G1/efeitos dos fármacos , Vison , Inibidores da Síntese de Ácido Nucleico/farmacologia , Proteínas E7 de Papillomavirus , RNA Mensageiro/metabolismo , Retroviridae/genética , Fase S/efeitos dos fármacos , Fatores de Tempo , Fator de Crescimento Transformador beta1RESUMO
Gut microbiota colonization is a key event for host physiology that occurs early in life. Disruption of this process leads to altered brain development which ultimately manifests as changes in brain function and behaviour in adulthood. Studies using germ-free (GF) mice highlight the extreme impact on brain health that results from life without commensal microbes. However, the impact of microbiota disturbances occurring in adulthood is less studied. To this end, we depleted the gut microbiota of 10-week-old male SpragueDawley rats via chronic antibiotic treatment. Following this marked, sustained depletion of the gut bacteria, we investigated behavioural and molecular hallmarks of gut-brain communication. Our results reveal that depletion of the gut microbiota during adulthood results in deficits in spatial memory as tested by Morris water maze, decreased visceral sensitivity and a greater display of depressive-like behaviours in the forced swim test. In tandem with these clear behavioural alterations we found changes in altered CNS serotonin concentration along with changes in the mRNA levels of corticotrophin releasing hormone receptor 1 and glucocorticoid receptor. Additionally, we found changes in the expression of brain derived neurotrophic factor (BDNF), a hallmark of altered microbiota-gut-brain axis signalling. In summary, this model of antibiotic-induced depletion of the gut microbiota can be used for future studies interested in the impact of the gut microbiota on host health without the confounding developmental influence of early-life microbial alterations.
Assuntos
Encéfalo/metabolismo , Depressão/microbiologia , Microbioma Gastrointestinal , Transtornos da Memória/microbiologia , Dor Visceral/microbiologia , Animais , Antibacterianos/farmacologia , Ansiedade/microbiologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Ceco/efeitos dos fármacos , Ceco/metabolismo , Corticosterona/sangue , Depressão/metabolismo , Fezes/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Masculino , Transtornos da Memória/metabolismo , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Receptores de Hormônio Liberador da Corticotropina/metabolismo , Receptores de Glucocorticoides/metabolismo , Serotonina/metabolismo , Dor Visceral/metabolismo , Dor Visceral/psicologiaRESUMO
BACKGROUND: The field of psychiatric epidemiology continues to employ self-report instruments, but the low degree of agreement between diagnoses achieved using these instruments vs. that achieved by psychiatrists in the clinical modality threatens the credibility of the results. METHODS: In the Baltimore Epidemiologic Catchment Area follow-up, 349 individuals who had a Diagnostic Interview Schedule (DIS) interview were blindly examined by psychiatrists using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN). Comparisons were made at the level of diagnosis, syndrome, and DSM-IV symptom group. Indexes of agreement were computed and characteristics of discrepant cases were identified. RESULTS: Agreement on diagnosis of major depressive disorder was only fair (kappa = 0.20), with the DIS missing many cases judged to meet criteria for diagnosis using the SCAN (29% sensitivity). A major source of discrepancy was respondents with false-negative diagnoses who repeatedly failed to report DIS symptoms attributed to life crises or medical conditions. Older age, male sex, and lower impairment were associated with underdetection by the DIS, using logistic regression analysis. In spite of the diagnostic discrepancy, there was substantial correlation in numbers of symptom groups in the 2 modalities (r = 0.49). Agreement was highest (about 55% sensitivity and 90% specificity) when both the SCAN and DIS thresholds were set at the level of depression syndrome instead of diagnosis. CONCLUSIONS: Weak agreement at the level of diagnosis continues to threaten the credibility of estimates of prevalence of specific disorders. A bias toward underreporting, as well as stronger agreement at the level of the depression syndrome and on ordinal measures of depressive symptoms, suggests that associations with risk factors are conservative.
Assuntos
Transtorno Depressivo/diagnóstico , Inquéritos Epidemiológicos , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Adolescente , Adulto , Baltimore/epidemiologia , Área Programática de Saúde , Transtorno Depressivo/epidemiologia , Reações Falso-Negativas , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prevalência , Análise de Regressão , Reprodutibilidade dos Testes , Fatores de RiscoRESUMO
This study provides national estimates of regular tobacco and alcohol use in India and their associations with gender, age, and economic group obtained from a representative survey of 471,143 people over the age of 10 years in 1995-96, the National Sample Survey. The national prevalence of regular use of smoking tobacco is estimated to be 16.2%, chewing tobacco 14.0%, and alcohol 4.5%. Men were 25.5 times more likely than women to report regular smoking, 3.7 times more likely to regularly chew tobacco, and 9.7 times more likely to regularly use alcohol. Respondents belonging to scheduled castes and tribes (recognized disadvantaged groups) were significantly more likely to report regular use of alcohol as well as smoking and chewing tobacco. People from rural areas had higher rates compared to urban dwellers, as did those with no formal education. Individuals with incomes below the poverty line had higher relative odds of use of chewing tobacco and alcohol compared to those above the poverty line. The regular use of both tobacco and alcohol also increased significantly with each diminishing income quintile. Comparisons are made between these results and those found in the United States and elsewhere, highlighting the need to address control of these substances on the public health agenda.
Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Alcoolismo/epidemiologia , Países em Desenvolvimento , Pobreza/estatística & dados numéricos , Fumar/epidemiologia , Tabagismo/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Comparação Transcultural , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Carência Psicossocial , Fatores de Risco , Fatores Sexuais , Fatores Socioeconômicos , Estados UnidosRESUMO
BACKGROUND: The microbiome is essential for normal myenteric intrinsic primary afferent neuron (IPAN) excitability. These neurons control gut motility and modulate gut-brain signaling by exciting extrinsic afferent fibers innervating the enteric nervous system via an IPAN to extrinsic fiber sensory synapse. We investigated effects of germ-free (GF) status and conventionalization on extrinsic sensory fiber discharge in the mesenteric nerve bundle and IPAN electrophysiology, and compared these findings with those from specific pathogen-free (SPF) mice. As we have previously shown that the IPAN calcium-dependent slow afterhyperpolarization (sAHP) is enhanced in GF mice, we also examined the expression of the calcium-binding protein calbindin in these neurons in these different animal groups. METHODS: IPAN sAHP and mesenteric nerve multiunit discharge were recorded using ex vivo jejunal gut segments from SPF, GF, or conventionalized (CONV) mice. IPANs were excited by adding 5 µM TRAM-34 to the serosal superfusate. We probed for calbindin expression using immunohistochemical techniques. KEY RESULTS: SPF mice had a 21% increase in mesenteric nerve multiunit firing rate and CONV mice a 41% increase when IPANs were excited by TRAM-34. For GF mice, this increase was barely detectable (2%). TRAM-34 changed sAHP area under the curve by -77 for SPF, +3 for GF, or -54% for CONV animals. Calbindin-immunopositive neurons per myenteric ganglion were 36% in SPF, 24% in GF, and 52% in CONV animals. CONCLUSIONS & INFERENCES: The intact microbiome is essential for normal intrinsic and extrinsic nerve function and gut-brain signaling.
Assuntos
Potenciais de Ação/fisiologia , Calbindinas/metabolismo , Microbioma Gastrointestinal/fisiologia , Vida Livre de Germes , Jejuno/inervação , Plexo Mientérico/fisiologia , Neurônios Aferentes/fisiologia , Potenciais de Ação/efeitos dos fármacos , Animais , Sistema Nervoso Entérico/efeitos dos fármacos , Sistema Nervoso Entérico/metabolismo , Sistema Nervoso Entérico/fisiologia , Feminino , Jejuno/metabolismo , Jejuno/microbiologia , Camundongos , Plexo Mientérico/efeitos dos fármacos , Plexo Mientérico/metabolismo , Neurônios Aferentes/efeitos dos fármacos , Pirazóis/farmacologia , Organismos Livres de Patógenos EspecíficosRESUMO
As an initial step toward investigating the roles of poliovirus proteins in viral RNA replication, a baculovirus expression system was used to produce poliovirus proteins from the P3 region. Spodoptera frugiperda (Sf9) cells were infected with a recombinant baculovirus, vETL-PoV3A*BCD, which contains cDNA coding for poliovirus proteins 3D, 3C, 3B, and a portion of 3A protein sequence. Immunofluorescence microscopy revealed that the majority of 3D (polymerase) was in the cytoplasm of recombinant baculovirus-infected Sf9 cells. In the same cells, the 3C (protease) and 3B (VPg) proteins appeared to be located in distinct subcellular regions, possibly membrane structures, suggesting that the expressed polyprotein was cleaved to generate mature proteins. Processing of the polypeptide was confirmed by immunoblot analysis which demonstrated that 3Cpro sequences were active in cleavage of the polyproteins 3A*BCD and 3CD. Over 95% of the 3D sequences accumulated in the form of mature 3Dpol, with only low levels of 3CD remaining. The majority of 3Dpol remained in the supernatant after low speed centrifugation of sonicated cells. The 3Dpol had RNA-dependent RNA polymerase activity as measured by elongation of an oligo(U) primer using a poly(A) template. The protein 3CDpro was active in cleaving P1 protein. The yield and activities of the poliovirus proteins expressed will facilitate future biochemical studies.
Assuntos
Poliovirus/genética , Proteínas Virais/genética , Animais , Baculoviridae/genética , Células Cultivadas , Expressão Gênica , Mariposas , Plasmídeos , Poliovirus/metabolismo , Processamento de Proteína Pós-Traducional , Recombinação Genética , Proteínas Virais/biossínteseRESUMO
The records of all patients entering the Emergency Department of a large general hospital and an adjacent walk-in medical clinic were reviewed for a 4-week period. Information was gathered on the assessment and treatment of patients given a final diagnosis of anxiety or panic disorder. The majority of patients receiving these diagnoses in both settings presented with physical complaints. In the Emergency Department, where psychiatric consultation services were available, psychiatric appointments were arranged for 80% of patients with anxiety as an entrance complaint and none of those with physical entrance complaints.
Assuntos
Transtornos de Ansiedade/terapia , Serviço Hospitalar de Emergência , Medo , Pânico , Encaminhamento e Consulta , Terapia Combinada , Hospitais Gerais , Humanos , Transtornos Mentais/terapia , Transtornos Somatoformes/terapiaRESUMO
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the analysis of erythromycin in human plasma (EDTA as anticoagulant) was developed and validated. The concentration ranges were 0.5-50 and 50-5000 ng ml-1. The procedure involved alkalization of 0.5 ml of plasma, one step liquid-liquid extraction, dryness of the extract and reconstitution in 80:20 water:acetonitrile. An Inertsil ODS-2 5 microns, 3.0 x 50 mm column (Metachem) with a C8 guard column and isocratic mobile phase were used for liquid chromatography. The mobile phase consisted of 1:1 acetonitrile:water with 2 mM NH4OAc and 0.1% HOAc. A flow rate of 0.7 ml min-1 was used. The analysis time on LC-MS/MS for one sample was approximately 2 min. A Turbo-Ionspray source was interfaced between the HPLC and triple quadrupole mass spectrometer (Sciex API III Plus). MS/MS analysis used Multi-Reaction Monitoring (MRM) mode. The lowest limit of quantitation (LOQ) was 0.5 ng ml-1 with all Quality Control (QC) sample recoveries varying between 88 and 105%. Nine intraday and interday calibration curves were generated yielding correlation coefficients ranging from 0.995 to 1.000. Average recovery for erythromycin at 1 ng ml-1 was 105% (+/- 4.5%). Average recovery for the internal standard was 83-103%. Short-term and long-term stability in the freezer (-20 degrees C), bench stability, and stability after 3 freeze/thaw cycles at -20 and -80 degrees C were conducted. The samples were found to be stable under all conditions. The method developed and validated proved useful for clinical pharmacokinetic study sample analysis with high throughput due to its high sensitivity and very short analysis time.