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INTRODUCTION: Olfactory neuroblastoma (ONB) is a rare cancer of the sinonasal region. We provide a comprehensive analysis of this malignancy with molecular and clinical trial data on a subset of our cohort to report on the potential efficacy of somatostatin receptor 2 (SSTR2)-targeting imaging and therapy. METHODS: We conducted a retrospective analysis of 404 primary, locally recurrent, and metastatic olfactory neuroblastoma (ONB) patients from 12 institutions in the United States of America, United Kingdom and Europe. Clinicopathological characteristics and treatment approach were evaluated. SSTR2 expression, SSTR2-targeted imaging and the efficacy of peptide receptor radionuclide therapy [PRRT](177Lu-DOTATATE) were reported in a subset of our cohort (LUTHREE trial; NCT03454763). RESULTS: Dural infiltration at presentation was a significant predictor of overall survival (OS) and disease-free survival (DFS) in primary cases (n = 278). Kadish-Morita staging and Dulguerov T-stage both had limitations regarding their prognostic value. Multivariable survival analysis demonstrated improved outcomes with lower stage and receipt of adjuvant radiotherapy. Prophylactic neck irradiation significantly reduces the rate of nodal recurrence. 82.4% of the cohort were positive for SSTR2; treatment of three metastatic cases with SSTR2-targeted peptide-radionuclide receptor therapy (PRRT) in the LUTHREE trial was well-tolerated and resulted in stable disease (SD). CONCLUSIONS: This study presents pertinent clinical data from the largest dataset, to date, on ONB. We identify key prognostic markers and integrate these into an updated staging system, highlight the importance of adjuvant radiotherapy across all disease stages, the utility of prophylactic neck irradiation and the potential efficacy of targeting SSTR2 to manage disease.
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Estesioneuroblastoma Olfatorio , Neuroblastoma , Neoplasias Nasales , Estesioneuroblastoma Olfatorio/patología , Estesioneuroblastoma Olfatorio/terapia , Humanos , Cavidad Nasal/metabolismo , Cavidad Nasal/patología , Neuroblastoma/patología , Neoplasias Nasales/radioterapia , Tomografía de Emisión de Positrones , Radioisótopos , Cintigrafía , Receptores de Somatostatina/metabolismo , Estudios RetrospectivosRESUMEN
Lower respiratory tract infections (LRTIs) are one of the fatal diseases of the lungs that have severe impacts on public health and the global economy. The currently available antibiotics administered orally for the treatment of LRTIs need high doses with frequent administration and cause dose-related adverse effects. To overcome this problem, we investigated the development of ciprofloxacin (CIP) loaded poly(2-ethyl-2-oxazoline) (PEtOx) nanoparticles (NPs) for potential pulmonary delivery from dry powder inhaler (DPI) formulations against LRTIs. NPs were prepared using a straightforward co-assembly reaction carried out by the intermolecular hydrogen bonding among PEtOx, tannic acid (TA), and CIP. The prepared NPs were characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction analysis (PXRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The CIP was determined by validated HPLC and UV spectrophotometry methods. The CIP loading into the PEtOx was between 21-67% and increased loading was observed with the increasing concentration of CIP. The NP sizes of PEtOx with or without drug loading were between 196-350 nm and increased with increasing drug loading. The in vitro CIP release showed the maximum cumulative release of about 78% in 168 h with a burst release of 50% in the first 12 h. The kinetics of CIP release from NPs followed non-Fickian or anomalous transport thus suggesting the drug release was regulated by both diffusion and polymer degradation. The in vitro aerosolization study carried out using a Twin Stage Impinger (TSI) at 60 L/min air flow showed the fine particle fraction (FPF) between 34.4% and 40.8%. The FPF was increased with increased drug loading. The outcome of this study revealed the potential of the polymer PEtOx as a carrier for developing CIP-loaded PEtOx NPs as DPI formulation for pulmonary delivery against LRTIs.
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Ciprofloxacina , Portadores de Fármacos , Nanopartículas/química , Poliaminas , Administración por Inhalación , Ciprofloxacina/química , Ciprofloxacina/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Inhaladores de Polvo Seco , Humanos , Poliaminas/química , Poliaminas/farmacocinéticaRESUMEN
Bacteria have evolved a multitude of systems to prevent invasion by bacteriophages and other mobile genetic elements. Comparative genomics suggests that genes encoding bacterial defence mechanisms are often clustered in 'defence islands', providing a concerted level of protection against a wider range of attackers. However, there is a comparative paucity of information on functional interplay between multiple defence systems. Here, we have functionally characterised a defence island from a multidrug resistant plasmid of the emerging pathogen Escherichia fergusonii. Using a suite of thirty environmentally-isolated coliphages, we demonstrate multi-layered and robust phage protection provided by a plasmid-encoded defence island that expresses both a type I BREX system and the novel GmrSD-family type IV DNA modification-dependent restriction enzyme, BrxU. We present the structure of BrxU to 2.12 Å, the first structure of the GmrSD family of enzymes, and show that BrxU can utilise all common nucleotides and a wide selection of metals to cleave a range of modified DNAs. Additionally, BrxU undergoes a multi-step reaction cycle instigated by an unexpected ATP-dependent shift from an intertwined dimer to monomers. This direct evidence that bacterial defence islands can mediate complementary layers of phage protection enhances our understanding of the ever-expanding nature of phage-bacterial interactions.
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Proteínas Bacterianas/química , Colifagos/genética , Enzimas de Restricción-Modificación del ADN/química , Escherichia coli/genética , Escherichia/genética , Plásmidos/química , Adenosina Trifosfato/química , Adenosina Trifosfato/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Sitios de Unión , Clonación Molecular , Colifagos/metabolismo , Cristalografía por Rayos X , Enzimas de Restricción-Modificación del ADN/genética , Enzimas de Restricción-Modificación del ADN/metabolismo , ADN Viral/química , ADN Viral/genética , ADN Viral/metabolismo , Escherichia/metabolismo , Escherichia/virología , Escherichia coli/metabolismo , Escherichia coli/virología , Expresión Génica , Islas Genómicas , Genómica/métodos , Modelos Moleculares , Plásmidos/metabolismo , Unión Proteica , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios y Motivos de Interacción de Proteínas , Multimerización de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidad por SustratoRESUMEN
BACKGROUND: To address the increasing incidence of gonorrhoea and antimicrobial resistance, we compared the efficacy of Listerine and Biotène mouthwashes for preventing gonorrhoea among men who have sex with men (MSM). METHODS: The OMEGA trial was a multicentre, parallel-group, double-blind randomised controlled trial among MSM, done at three urban sexual health clinics and one general practice clinic in Australia. Men were eligible if they were diagnosed with oropharyngeal gonorrhoea by nucleic acid amplification test (NAAT) in the previous 30 days or were aged 16-24 years. They were randomly assigned to receive Listerine (intervention) or Biotène (control) via a computer-generated sequence (1:1 ratio, block size of four). Participants, clinicians, data collectors, data analysts, and outcome adjudicators were masked to the interventions after assignment. Participants were instructed to rinse and gargle with 20 mL of mouthwash for 60 s at least once daily for 12 weeks. Oropharyngeal swabs were collected by research nurses every 6 weeks, and participants provided saliva samples every 3 weeks, to be tested for Neisseria gonorrhoeae with NAAT and quantitative PCR. The primary outcome was proportion of MSM diagnosed with oropharyngeal N gonorrhoeae infection at any point over the 12-week period, defined as a positive result for either oropharyngeal swabs or saliva samples by NAAT, and the cumulative incidence of oropharyngeal gonorrhoea at the week 12 visit. A modified intention-to-treat analysis for the primary outcome was done that included men who provided at least one follow-up specimen over the 12-week study period. The trial was registered on the Australian and New Zealand Clinical Trials Registry (ACTRN12616000247471). FINDINGS: Between March 30, 2016, and Oct 26, 2018, 786 MSM were screened and 256 were excluded. 264 MSM were randomly assigned to the Biotène group and 266 to the Listerine group. The analysis population included 227 (86%) men in the Biotène group and 219 (82%) in the Listerine group. Oropharyngeal gonorrhoea was detected in ten (4%) of 227 of MSM in the Biotène group and in 15 (7%) of 219 in the Listerine group (adjusted risk difference 2·5%, 95% CI -1·8 to 6·8). The cumulative incidence of oropharyngeal gonorrhoea at the week 12 visit did not differ between the two mouthwash groups (adjusted risk difference 3·1%, 95% CI -1·4 to 7·7). INTERPRETATION: Listerine did not reduce the incidence of oropharyngeal gonorrhoea compared with Biotène. However, previous research suggests that mouthwash might reduce the infectivity of oropharyngeal gonorrhoea; therefore, further studies of mouthwash examining its inhibitory effect on N gonorrhoeae are warranted to determine if it has a potential role for the prevention of transmission. FUNDING: Australian National Health and Medical Research Council.
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Antiinfecciosos Locales/uso terapéutico , Gonorrea/prevención & control , Antisépticos Bucales/uso terapéutico , Adulto , Australia , Método Doble Ciego , Combinación de Medicamentos , Glucosa Oxidasa , Homosexualidad Masculina , Humanos , Lactoperoxidasa , Masculino , Estudios Multicéntricos como Asunto , Muramidasa , Neisseria gonorrhoeae/efectos de los fármacos , Nueva Zelanda , Infecciones del Sistema Respiratorio/prevención & control , Salicilatos/uso terapéutico , Minorías Sexuales y de Género , Encuestas y Cuestionarios , Terpenos/uso terapéutico , Adulto JovenRESUMEN
BACKGROUND: Macrolide resistance in Mycoplasma genitalium (MG) exceeds 50% in many regions, and quinolone resistance is increasing. We recently reported that resistance-guided therapy (RGT) using doxycycline followed by sitafloxacin or 2.5 g azithromycin cured 92% and 95% of macrolide-resistant and macrolide-susceptible infections, respectively. We present data on RGT using doxycycline-moxifloxacin, the regimen recommended in international guidelines, and extend data on the efficacy of doxycycline-2.5 g azithromycin and de novo macrolide resistance. METHODS: Patients attending Melbourne Sexual Health Centre between 2017 and 2018 with sexually transmitted infection syndromes were treated with doxycycline for 7 days and recalled if MG-positive. Macrolide-susceptible cases received 2.5 g azithromycin (1 g, then 500 mg daily for 3 days), and resistant cases moxifloxacin (400 mg daily, 7 days). Test of cure was recommended 14-28 days post-antimicrobials. RESULTS: There were 383 patients (81 females/106 heterosexual males/196 men who have sex with men) included. Microbial cure following doxycycline-azithromycin was 95.4% (95% confidence interval [CI], 89.7-98.0) and doxycycline-moxifloxacin was 92.0% (95% CI, 88.1-94.6). De novo macrolide resistance was detected in 4.6% of cases. Combining doxycycline-azithromycin data with our prior RGT study (n = 186) yielded a pooled cure of 95.7% (95% CI, 91.6-97.8). ParC mutations were present in 22% of macrolide-resistant cases. CONCLUSIONS: These findings support the inclusion of moxifloxacin in resistance-guided strategies and extend the evidence for 2.5 g azithromycin and presumptive use of doxycycline. These data provide an evidence base for current UK, Australian, and European guidelines for the treatment of MG.
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Infecciones por Mycoplasma , Mycoplasma genitalium , Minorías Sexuales y de Género , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Australia/epidemiología , Azitromicina/uso terapéutico , Doxiciclina/uso terapéutico , Farmacorresistencia Bacteriana , Femenino , Homosexualidad Masculina , Humanos , Macrólidos/uso terapéutico , Masculino , Moxifloxacino , Infecciones por Mycoplasma/tratamiento farmacológicoRESUMEN
Peatlands are globally significant sources of atmospheric methane (CH4). While several studies have examined the effects of nutrient addition on CH4 dynamics, there are few long-term peatland fertilization experiments, which are needed to understand the aggregated effects of nutrient deposition on ecosystem functioning. We investigated responses of CH4 flux and production to long-term field treatments with three levels of N (1.6-6.4 g m-2 yr-1 as NH4NO3), potassium and phosphorus (PK, 5.0 g P and 6.3 g K m-2 yr-1 as KH2PO4), and NPK in a temperate bog. Methane fluxes were measured in the field from May to August in 2005 and 2015. In 2015 CH4 flux was higher in the NPK treatment with 16 years of 6.4 g N m-2 yr-1 than in the control (50.5 vs. 8.6 mg CH4 m-2 d-1). The increase in CH4 flux was associated with wetter conditions derived from peat subsidence. Incubation of peat samples, with and without short-term PK amendment, showed that potential CH4 production was enhanced in the PK treatments, both from field application and by amending the incubation. We suggest that changes in this bog ecosystem originate from long-term vegetation change, increased decomposition and direct nutrient effects on microbial dynamics.
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Metano/química , Nutrientes/química , Suelo/química , Dióxido de Carbono/análisis , Ecosistema , Metano/análisis , Nitrógeno/metabolismo , Ontario , Fósforo/metabolismo , Potasio/metabolismo , Estaciones del Año , HumedalesRESUMEN
BACKGROUND: We report clinical characteristics of proctitis caused solely by Mycoplasma genitalium (MG) compared with chlamydia and gonococcus. We determined the proportions cured with first-line (azithromycin) and second-line antimicrobials (moxifloxacin, pristinamycin). METHODS: A total of 166 patients attending Melbourne Sexual Health Centre from 2012 to 2016 with symptoms of proctitis were tested for MG, Chlamydia trachomatis, and Neisseria gonorrhoeae. Demographic characteristics, sexual behaviors, clinical symptoms, and signs were recorded. Multinomial multivariable logistic regression was used to test for significant differences in symptoms and signs for the pathogens detected. RESULTS: Seventeen percent of men had MG (95% confidence interval, 12-24), 21% had chlamydia (15-27), and 40% had gonococcal monoinfection (32-48), whereas 22% had MG coinfection (16-29). Relative to men with MG monoinfection, those with chlamydial monoinfection reported more anal pain (adjusted prevalence odds ratio (aPOR), 4.68 [1.41-14.19]), whereas men with gonococcal monoinfection reported more anal pain (aPOR, 6.75 [2.21-20.55]) and tenesmus (aPOR, 15.44 [1.62-146.90]), but less anal itch (aPOR, 0.32 [0.11-0.93]). The microbiological cure for MG using azithromycin was low at 35% (22-50), whereas moxifloxacin subsequently cured 92% (64-100) and pristinamycin cured 79% (54-94) of infections. CONCLUSIONS: M. genitalium was almost as common as chlamydia in men presenting to a sexual health center with symptoms of proctitis. Men with anorectal MG monoinfection were less likely to have symptoms and signs compared with those with chlamydia or gonococcus monoinfection. Cure for men with symptomatic anorectal MG by azithromycin was low. We suggest routine testing for MG in cases of proctitis, with test of cure after treatment being essential.
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Antiinfecciosos/uso terapéutico , Gonorrea/epidemiología , Gonorrea/microbiología , Infecciones por Mycoplasma/microbiología , Mycoplasma genitalium/aislamiento & purificación , Proctitis/microbiología , Enfermedades del Recto/microbiología , Adulto , Azitromicina/uso terapéutico , Chlamydia trachomatis/aislamiento & purificación , Coinfección , Gonorrea/tratamiento farmacológico , Homosexualidad Masculina , Humanos , Masculino , Moxifloxacino/uso terapéutico , Infecciones por Mycoplasma/tratamiento farmacológico , Infecciones por Mycoplasma/epidemiología , Neisseria gonorrhoeae/aislamiento & purificación , Pristinamicina/uso terapéutico , Proctitis/tratamiento farmacológico , Proctitis/epidemiología , Enfermedades del Recto/tratamiento farmacológico , Enfermedades del Recto/epidemiología , Conducta Sexual , Minorías Sexuales y de Género , Victoria/epidemiología , Adulto JovenRESUMEN
Huanglongbing (HLB), a systemic and destructive disease of citrus, is associated with 'Candidatus Liberibacter asiaticus' (Las) in the United States. Our earlier work has shown that Las bacteria were significantly reduced or eliminated when potted HLB-affected citrus were continuously exposed to high temperatures of 40 to 42 °C for a minimum of 48 h. To determine the feasibility and effectiveness of solar thermotherapy in the field, portable plastic enclosures were placed over commercial and residential citrus, exposing trees to high temperatures through solarization. Within 3-6 weeks after treatment, most trees responded with vigorous new growth. Las titer in new growth was greatly reduced for 18-36 months after treatment. Unlike with potted trees, exposure to high heat did not eradicate the Las population under field conditions. This may be attributed to reduced temperatures at night in the field compared to continuous high temperature exposure that can be maintained in growth chambers, and the failure to achieve therapeutic temperatures in the root zone. Despite the presence of Las in heat-treated commercial citrus, many trees produced abundant flush and grew vigorously for 2 to 3 years after treatment. Transcriptome analysis comparing healthy trees to HLB-affected citrus both before and after heat treatment demonstrated that post-treatment transcriptional expression patterns more closely resembled the expression patterns of healthy controls for most differentially expressed genes and that genes involved with plant-bacterium interactions are upregulated after heat treatment. Overall, these results indicate that solar thermotherapy can be an effective component of an integrated control strategy for citrus HLB.
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BACKGROUND: Shift work is often associated with sleepiness and sleep disorders. Person-directed, non-pharmacological interventions may positively influence the impact of shift work on sleep, thereby improving workers' well-being, safety, and health. OBJECTIVES: To assess the effects of person-directed, non-pharmacological interventions for reducing sleepiness at work and improving the length and quality of sleep between shifts for shift workers. SEARCH METHODS: We searched CENTRAL, MEDLINE Ovid, Embase, Web of Knowledge, ProQuest, PsycINFO, OpenGrey, and OSH-UPDATE from inception to August 2015. We also screened reference lists and conference proceedings and searched the World Health Organization (WHO) Trial register. We contacted experts to obtain unpublished data. SELECTION CRITERIA: Randomised controlled trials (RCTs) (including cross-over designs) that investigated the effect of any person-directed, non-pharmacological intervention on sleepiness on-shift or sleep length and sleep quality off-shift in shift workers who also work nights. DATA COLLECTION AND ANALYSIS: At least two authors screened titles and abstracts for relevant studies, extracted data, and assessed risk of bias. We contacted authors to obtain missing information. We conducted meta-analyses when pooling of studies was possible. MAIN RESULTS: We included 17 relevant trials (with 556 review-relevant participants) which we categorised into three types of interventions: (1) various exposures to bright light (n = 10); (2) various opportunities for napping (n = 4); and (3) other interventions, such as physical exercise or sleep education (n = 3). In most instances, the studies were too heterogeneous to pool. Most of the comparisons yielded low to very low quality evidence. Only one comparison provided moderate quality evidence. Overall, the included studies' results were inconclusive. We present the results regarding sleepiness below. Bright light Combining two comparable studies (with 184 participants altogether) that investigated the effect of bright light during the night on sleepiness during a shift, revealed a mean reduction 0.83 score points of sleepiness (measured via the Stanford Sleepiness Scale (SSS) (95% confidence interval (CI) -1.3 to -0.36, very low quality evidence). Another trial did not find a significant difference in overall sleepiness on another sleepiness scale (16 participants, low quality evidence).Bright light during the night plus sunglasses at dawn did not significantly influence sleepiness compared to normal light (1 study, 17 participants, assessment via reaction time, very low quality evidence).Bright light during the day shift did not significantly reduce sleepiness during the day compared to normal light (1 trial, 61 participants, subjective assessment, low quality evidence) or compared to normal light plus placebo capsule (1 trial, 12 participants, assessment via reaction time, very low quality evidence). Napping during the night shiftA meta-analysis on a single nap opportunity and the effect on the mean reaction time as a surrogate for sleepiness, resulted in a 11.87 ms reduction (95% CI 31.94 to -8.2, very low quality evidence). Two other studies also reported statistically non-significant decreases in reaction time (1 study seven participants; 1 study 49 participants, very low quality evidence).A two-nap opportunity resulted in a statistically non-significant increase of sleepiness (subjective assessment) in one study (mean difference (MD) 2.32, 95% CI -24.74 to 29.38, 1 study, 15 participants, low quality evidence). Other interventionsPhysical exercise and sleep education interventions showed promise, but sufficient data to draw conclusions are lacking. AUTHORS' CONCLUSIONS: Given the methodological diversity of the included studies, in terms of interventions, settings, and assessment tools, their limited reporting and the very low to low quality of the evidence they present, it is not possible to determine whether shift workers' sleepiness can be reduced or if their sleep length or quality can be improved with these interventions.We need better and adequately powered RCTs of the effect of bright light, and naps, either on their own or together and other non-pharmacological interventions that also consider shift workers' chronobiology on the investigated sleep parameters.
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Reposo en Cama , Trastornos de Somnolencia Excesiva/terapia , Ejercicio Físico , Fototerapia/métodos , Trastornos del Sueño del Ritmo Circadiano/terapia , Tolerancia al Trabajo Programado , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Factores de TiempoRESUMEN
Soy foods are the richest sources of isoflavones, mainly daidzein and genistein. Soy isoflavones are structurally similar to the steroid hormone 17ß-estradiol and may protect against breast cancer. S-(-)equol, a metabolite of the soy isoflavone daidzein, has a higher bioavailability and greater affinity for estrogen receptor ß than daidzein. Approximately one-third of the Western population is able to produce S-(-)equol, and the ability is linked to certain gut microbes. We hypothesized that the prevalence of breast cancer, ductal hyperplasia, and overall breast pathology will be lower among S-(-)equol producing, as compared with nonproducing, postmenopausal women undergoing a breast biopsy. We tested our hypothesis using a cross-sectional study design. Usual diets of the participants were supplemented with 1 soy bar per day for 3 consecutive days. Liquid chromatography-multiple reaction ion monitoring mass spectrometry analysis of urine from 143 subjects revealed 25 (17.5%) as S-(-)equol producers. We found no statistically significant associations between S-(-)equol producing status and overall breast pathology (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.23-1.89), ductal hyperplasia (OR, 0.84; 95% CI, 0.20-3.41), or breast cancer (OR, 0.56; 95% CI, 0.16-1.87). However, the mean dietary isoflavone intake was much lower (0.3 mg/d) than in previous reports. Given that the amount of S-(-)equol produced in the gut depends on the amount of daidzein exposure, the low soy intake coupled with lower prevalence of S-(-)equol producing status in the study population favors toward null associations. Findings from our study could be used for further investigations on S-(-)equol producing status and disease risk.
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Neoplasias de la Mama/etiología , Mama/patología , Dieta , Equol/biosíntesis , Glycine max/química , Isoflavonas/administración & dosificación , Fitoestrógenos/administración & dosificación , Anciano , Disponibilidad Biológica , Biopsia , Neoplasias de la Mama/metabolismo , Estudios Transversales , Suplementos Dietéticos , Equol/metabolismo , Equol/orina , Receptor beta de Estrógeno/metabolismo , Conducta Alimentaria , Femenino , Humanos , Isoflavonas/farmacología , Persona de Mediana Edad , Oportunidad Relativa , Fitoestrógenos/farmacología , Posmenopausia , Alimentos de Soja , Estados UnidosRESUMEN
Plant resorption of multiple nutrients during leaf senescence has been established but stoichiometric changes among N, P and K during resorption and after fertilization are poorly understood. We anticipated that increased N supply would lead to further P limitation or co-limitation with N or K [i.e. P-(co)limitation], decrease N resorption and increase P and K resorption, while P and K addition would decrease P and K resorption and increase N resorption. Furthermore, Ca would accumulate while Mg would be resorbed during leaf senescence, irrespective of fertilization. We investigated the effect of N, P and K addition on resorption in two evergreen shrubs (Chamaedaphne calyculata and Rhododendron groenlandicum) in a long-term fertilization experiment at Mer Bleue bog, Ontario, Canada. In general, N addition caused further P-(co)limitation, increased P and K resorption efficiency but did not affect N resorption. P and K addition did not shift the system to N limitation and affect K resorption, but reduced P resorption proficiency. C. calyculata resorbed both Ca and Mg while R. groenlandicum resorbed neither. C. calyculata showed a higher resorption than R. groenlandicum, suggesting it is better adapted to nutrient deficiency than R. groenlandicum. Resorption during leaf senescence decreased N:P, N:K and K:P ratios. The limited response of N and K and the response of P resorption to fertilization reflect the stoichiometric coupling of nutrient cycling, which varies among the two shrub species; changes in species composition may affect nutrient cycling in bogs.
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Ericaceae/metabolismo , Fertilizantes , Nitrógeno/metabolismo , Fósforo/metabolismo , Potasio/metabolismo , Humedales , Calcio/metabolismo , Magnesio/metabolismo , Ontario , Hojas de la Planta/metabolismoRESUMEN
To study vegetation feedbacks of nutrient addition on carbon sequestration capacity, we investigated vegetation and ecosystem CO2 exchange at Mer Bleue Bog, Canada in plots that had been fertilized with nitrogen (N) or with N plus phosphorus (P) and potassium (K) for 7-12 years. Gross photosynthesis, ecosystem respiration, and net CO2 exchange were measured weekly during May-September 2011 using climate-controlled chambers. A substrate-induced respiration technique was used to determine the functional ability of the microbial community. The highest N and NPK additions were associated with 40% less net CO2 uptake than the control. In the NPK additions, a diminished C sink potential was due to a 20-30% increase in ecosystem respiration, while gross photosynthesis rates did not change as greater vascular plant biomass compensated for the decrease in Sphagnum mosses. In the highest N-only treatment, small reductions in gross photosynthesis and no change in ecosystem respiration led to the reduced C sink. Substrate-induced microbial respiration was significantly higher in all levels of NPK additions compared with control. The temperature sensitivity of respiration in the plots was lower with increasing cumulative N load, suggesting more labile sources of respired CO2 . The weaker C sink potential could be explained by changes in nutrient availability, higher woody : foliar ratio, moss loss, and enhanced decomposition. Stronger responses to NPK fertilization than to N-only fertilization for both shrub biomass production and decomposition suggest that the bog ecosystem is N-P/K colimited rather than N-limited. Negative effects of further N-only deposition were indicated by delayed spring CO2 uptake. In contrast to forests, increased wood formation and surface litter accumulation in bogs seem to reduce the C sink potential owing to the loss of peat-forming Sphagnum.
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Dióxido de Carbono/metabolismo , Secuestro de Carbono , Ecosistema , Nitrógeno/metabolismo , Fósforo/metabolismo , Plantas/metabolismo , Potasio/metabolismo , Ontario , Estaciones del Año , HumedalesRESUMEN
OBJECTIVE: To investigate the effect of risperidone on energy expenditure and weight gain in female C57BL/6J mice. DESIGN AND METHODS: Body weight and composition, food intake, energy expenditure, and activity were determined weekly. mRNA expression of uncoupling protein 1 in brown adipose tissue, orexin, and brain-derived neurotrophic factor in the hypothalamus were quantified using real-time PCR. RESULTS: Risperidone tended to induce a greater body weight gain (P = 0.052) and significantly higher food intake (P = 0.038) relative to the placebo-treated group. Risperidone-treated mice had a higher resting energy expenditure (P = 0.001) and total energy expenditure (TEE) (P = 0.005) than the placebo group. There were no effects of treatment, time, and treatment by time on non-resting (or activity-related) energy expenditure between groups. Risperidone-treated mice showed a significantly lesser locomotor activity than placebo-treated mice over 3 weeks (P < 0.001). Risperidone induced a higher UCP1 mRNA (P = 0.003) and a lower orexin mRNA (P = 0.001) than placebo. CONCLUSION: Risperidone-induced weight gain is associated with hyperphagia and a reduction in locomotor activity in C57BL/6J mice. Additionally, higher total and resting energy expenditure were accompanied by higher levels of UCP1 mRNA in BAT. The increased TEE could not offset the total intake of energy through risperidone-induced hyperphagia, therefore resulting in weight gain in female C57BL/6J mice.
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Antipsicóticos/efectos adversos , Ingestión de Energía/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Hiperfagia/inducido químicamente , Actividad Motora/efectos de los fármacos , Risperidona/efectos adversos , Aumento de Peso/efectos de los fármacos , Tejido Adiposo Pardo/metabolismo , Animales , Metabolismo Basal/efectos de los fármacos , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Femenino , Hiperfagia/metabolismo , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Canales Iónicos/genética , Canales Iónicos/metabolismo , Ratones , Ratones Endogámicos C57BL , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Neuropéptidos/genética , Neuropéptidos/metabolismo , Obesidad/inducido químicamente , Obesidad/genética , Obesidad/metabolismo , Orexinas , Proteína Desacopladora 1RESUMEN
BACKGROUND AND OBJECTIVE: Bone mineral deficiency continues to occur in extremely-low-birth-weight (ELBW) infants despite formulas enriched in calcium (Ca) and phosphorus (P). This study tested whether extra enteral Ca supplementation increases bone mineral content (BMC) and prevents dolichocephalic head flattening and myopia in ELBW infants. STUDY DESIGN: Infants 401 to 1000 birth weight receiving enteral feeds were randomized to receive feeds supplemented with Ca-gluconate powder or pure standard feeds. The main outcome measures were the excretion of Ca and P by weekly spot urine measurements, the degree of dolichocephalic deformation (fronto-occipital diameter to biparietal diameter ratio, FOD/BPD) at 36 weeks postmenstrual age, and the BMC (by dual-energy x-ray absorptiometry) at discharge. Cycloplegic refraction was measured at 18 to 22 months corrected age. PATIENTS AND RESULTS: Ninety-nine ELBW infants with a gestational age of 26 weeks (23-31) (median [minimum-maximum]) were randomized at a postnatal age of 12 days (5-23) weighing 790âg (440-1700). Urinary Ca excretion increased and P excretion decreased in the Ca-supplemented group. Total BMC was 89.9 ± 2.4 g (meanâ±âSE) in the supplemented group and 85.2 ± 2.6 g in the control group (P = 0.19). The FOD/BPD was 1.50 (1.13-1.69, mean ± SD [standard deviation]) and 1.47 (1.18-1.64) in the supplemented and control groups, and the refraction 0.98â ± 1.23 and 1.40 ± 1.33 dpt (P = 0.68), respectively in 64 ELBW infants (79% of survivors) at 2-year follow-up. CONCLUSIONS: Extra enteral Ca supplementation did not change BMC, head shape, or refraction. The decreased P excretion may reflect P deficiency in infants receiving extra Ca, preventing improved bone mineral accretion.
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Densidad Ósea/efectos de los fármacos , Calcio de la Dieta/administración & dosificación , Suplementos Dietéticos , Recien Nacido con Peso al Nacer Extremadamente Bajo/metabolismo , Absorciometría de Fotón , Calcio/deficiencia , Gluconato de Calcio/administración & dosificación , Estudios de Casos y Controles , Nutrición Enteral , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Fósforo/deficienciaRESUMEN
Zebrafish (Danio rerio) skeletal bone possesses properties similar to human bone, which suggests that they may be used as a model to study mineralization characteristics of the human Haversian system, as well as human bone diseases. One prerequisite for the use of zebrafish as an alternative osteoporotic bone model is to determine whether their bone displays functional plasticity similar to that observed in other bone models. Strontium citrate was supplemented into a laboratory-prepared diet (45% crude protein) to produce dietary strontium levels of 0%, 0.63%, 1.26%, 1.89%, and 2.43% and fed ad libitum twice daily for 12 weeks to 28-day-old intact zebrafish. Length was determined at 4-week intervals, and both weight and length were recorded at 12 weeks. At 12 weeks, seven zebrafish from each dietary level were analyzed for total bone mineral density by microcomputed tomography. Dietary strontium citrate supplementation significantly (p < 0.05) increased zebrafish whole-body and spinal column bone mineral density. In addition, trace amounts of strontium were incorporated into the scale matrix in those zebrafish that consumed strontium-supplemented diets. These findings suggest that zebrafish bone displays plasticity similar to that reported for other bone models (i.e., rat, mouse, and monkey) that received supplements of strontium compounds and zebrafish should be viewed as an increasingly valuable bone model.
Asunto(s)
Densidad Ósea/efectos de los fármacos , Huesos/efectos de los fármacos , Estroncio/farmacología , Pez Cebra/fisiología , Alimentación Animal , Animales , Microtomografía por Rayos XRESUMEN
Cancer is a leading cause of death worldwide, and the numbers of new cancer cases are expected to continue to rise. The main goals of cancer therapy include removing the primary tumor, preventing the spread of distant metastases, and improving survival and quality of life for the patients. To attain these goals of cancer therapy, the combination of different chemotherapeutics, as opposed to the conventional single-agent treatment, is an emerging area of research. Given the potential risks of drug toxicity in such treatment, the focus is to have a second compound that increases the anticancer potential of the primary agent but which reduces toxicity. There is an ever growing interest in treatment with natural compounds, such as plant phytoestrogens, as an adjuvant cancer therapy along with conventional cancer therapy. The question remains whether or not adding these compounds to the cancer therapy regimen as a second agent would be beneficial, and if they are safe to be used among cancer patients. The current literature suggests that phytoestrogen treatment is capable of inducing G2/M cell cycle arrest in a number of cancer cell lines, as well as upregulating cell cycle inhibitory molecules. Phytoestrogen therapy has been shown to inhibit inflammation, angiogenesis and metastases in various IN VIVO tumor models, and pronounced benefits have been observed when combined with radiation therapy. The lack of side effects from phase I and II clinical trials of phytoestrogens in cancer therapy points towards their safety, but to further understand their added benefit clinical studies with large sample sizes are required. We have reviewed the recent research studies in these areas in an attempt to find evidence for their role in cancer therapy as well as safety.
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Antineoplásicos Fitogénicos/uso terapéutico , Neoplasias/tratamiento farmacológico , Fitoestrógenos/uso terapéutico , Animales , Antineoplásicos Fitogénicos/metabolismo , Ciclo Celular/efectos de los fármacos , Quimioterapia Adyuvante , Humanos , Inflamación/tratamiento farmacológico , Isoflavonas/química , Isoflavonas/metabolismo , Isoflavonas/uso terapéutico , Lignanos/química , Lignanos/metabolismo , Lignanos/uso terapéutico , Ratones , Metástasis de la Neoplasia , Neovascularización Patológica/tratamiento farmacológico , Fitoestrógenos/química , Fitoestrógenos/metabolismo , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
The prevalence of obesity in industrialized societies has become markedly elevated. In contrast, model organism research shows that reducing caloric intake below ad libitum levels provides many health and longevity benefits. Despite these benefits, few people are willing and able to reduce caloric intake over prolonged periods. Prior research suggests that mannooligosaccharide (MOS or mannan) supplementation can increase lifespan of some livestock and in rodents can reduce visceral fat without reducing caloric intake. Hence, we tested the effect of MOS supplementation as a possible calorie restriction (CR) mimetic (CRM) in mice. C57Bl/6J male mice were fed a high-fat "western" type diet with or without 1% MOS (by weight) supplementation (n = 24/group) from 8 to 20 weeks of age. Animals were housed individually and provided 95% of ad libitum food intake throughout the study. Body weight was measured weekly and body composition (lean and fat mass) measured noninvasively every 3 weeks. Individual fat depot weights were acquired by dissection at study completion. Supplementation of a high-fat diet with 1% MOS tended to reduce total food intake (mean +/- s.d.; control (CON): 293.69 +/- 10.53 g, MOS: 288.10 +/- 11.82 g; P = 0.09) during the study. Moreover, MOS supplementation had no significant effect on final body weight (CON: 25.21 +/- 2.31 g, MOS: 25.28 +/- 1.49 g; P = 0.91), total fat (CON: 4.72 +/- 0.90 g, MOS: 4.82 +/- 0.83 g; P = 0.69), or visceral fat (CON: 1.048 +/- 0.276 g, MOS: 1.004 +/- 0.247 g; P = 0.57). Contrary to previous research, MOS supplementation had no discernable effect on body weight gain or composition during this 12-week study, challenging the potential use of MOS as a CRM or body composition enhancer.
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Composición Corporal/efectos de los fármacos , Suplementos Dietéticos , Mananos , Aumento de Peso/efectos de los fármacos , Análisis de Varianza , Animales , Dieta , Grasas de la Dieta , Ingestión de Alimentos/efectos de los fármacos , Imagen por Resonancia Magnética , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
Risperidone induces significant weight gain in female mice; however, the underlying mechanisms related to this effect are unknown. We investigated the effects of risperidone on locomotor activity, core body temperature, and uncoupling protein (UCP) and hypothalamic orexin mRNA expression. Female C57BL/6J mice were acclimated to individual housing and randomly assigned to either risperidone (4 mg/kg BW day) or placebo (PLA). Activity and body temperature were measured over 48-hour periods twice a week for 3 weeks. Food intake and body weights were measured weekly. UCP1 (BAT), UCP3 (gastrocnemius), and orexin (hypothalamus) mRNA expressions were measured using RT-PCR. Risperidone-treated mice consumed more food (p=0.050) and gained more weight (p=0.0001) than PLA-treated mice after 3 weeks. During the initial 2 days of treatment, there was an acute effect of treatment on activity (p=0.046), but not body temperature (p=0.290). During 3 weeks of treatment, average core body temperatures were higher in risperidone-treated mice compared to controls during the light phase (p=0.0001), and tended to be higher during the dark phase (p=0.057). Risperidone-treated mice exhibited lower activity levels than controls during the dark phase (p=0.006); there were no differences in activity during the light phase (p=0.47). UCP1 (p<0.01) and UCP3 (p<0.05) mRNA expressions were greater in risperidone-treated mice compared to controls, whereas, orexin mRNA expression was lower in risperidone-treated mice (p<0.01). These results suggest that risperidone-induced weight gain in mice is a consequence of increased energy intake and reduced activity, while the elevation in body temperature may be a result of thermogenic effect of food intake and elevated UCP1, UCP3, and a reduced hypothalamic orexin expression.
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Antipsicóticos/farmacología , Regulación del Apetito/efectos de los fármacos , Regulación de la Temperatura Corporal/efectos de los fármacos , Actividad Motora/efectos de los fármacos , Risperidona/farmacología , Análisis de Varianza , Animales , Ingestión de Alimentos/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Femenino , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Péptidos y Proteínas de Señalización Intracelular/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Canales Iónicos/efectos de los fármacos , Canales Iónicos/genética , Canales Iónicos/metabolismo , Ratones , Ratones Endogámicos C57BL , Proteínas Mitocondriales/efectos de los fármacos , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Neuropéptidos/efectos de los fármacos , Neuropéptidos/genética , Neuropéptidos/metabolismo , Orexinas , ARN Mensajero/análisis , Distribución Aleatoria , Proteína Desacopladora 1 , Proteína Desacopladora 3 , Aumento de Peso/efectos de los fármacosRESUMEN
The large accumulation of organic matter in peatlands has been partially attributed to litter decomposition rates, which are slowed by a high water table. To test this, we examined whether there were significant differences in the decomposition and N and P dynamics of ten foliar litters and wood blocks at three pairs of upland forest and peatland sites in the transitional grassland, high boreal and low subarctic regions of central Canada, using litterbags collected over a 12-year period. At two of the three pairs, the decomposition rate, as determined by proportion of the original mass remaining after 12 years and by the exponential decay coefficient (k), was faster overall at the upland than at the peatland. In the third pair, there was no significant difference, despite the water table being close to the peat surface; warmer soil temperatures in the peatland than the upland may be the cause. In general, there were small losses or gains of N in the litters after 12 years, compared to the original litter, though there were some differences among litter types and sites, net gains in N likely reflecting the higher exogenous N availability. P was lost from most litters at the two northern pairs of sites, but at the transitional grassland pair, there were large net gains in P and greater variation among litters. The N:P ratio in the original litters ranged from 5 to 26 and after 12 years the ratio narrowed, with the site average of the ten litters ranging from 13 to 22, varying with the soil ratio. Decomposition rates and N and P dynamics after 12 years are different between upland and peatland sites: although the water table is a primary control on these differences, other factors such as temperature and soil nutrient status are also important.
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Geografía , Nitrógeno/análisis , Fósforo/análisis , Suelo , Canadá , Festuca/crecimiento & desarrollo , Picea/crecimiento & desarrollo , Populus/crecimiento & desarrollo , Agua , Movimientos del AguaRESUMEN
The segmentation of the proximal-distal axis of the Drosophila melanogaster leg depends on the localized activation of the Notch receptor. The expression of the Notch ligand genes Serrate and Delta in concentric, segmental rings results in the localized activation of Notch, which induces joint formation and is required for the growth of leg segments. We report here that the expression of Serrate and Delta in the leg is regulated by the transcription factor genes dAP-2 and defective proventriculus. Previous studies have shown that Notch activation induces dAP-2 in cells distal and adjacent to the Serrate/Delta domain of expression. We find that Serrate and Delta are ectopically expressed in dAP-2 mutant legs and that Serrate and Delta are repressed by ectopic expression of dAP-2. Furthermore, Serrate is induced cell-autonomously in dAP-2 mutant clones in many regions of the leg. We also find that the expression of a defective proventriculus reporter overlaps with dAP-2 expression and is complementary to Serrate expression in the tarsal segments. Ectopic expression of defective proventriculus is sufficient to block joint formation and Serrate and Delta expression. Loss of defective proventriculus results in localized, ectopic Serrate expression and the formation of ectopic joints with reversed polarity. Thus, in tarsal segments, dAP-2 and defective proventriculus are necessary for the correct proximal and distal boundaries of Serrate expression and repression of Serrate by defective proventriculus contributes to tarsal segment asymmetry. The repression of the Notch ligand genes Serrate and Delta by the Notch target gene dAP-2 may be a pattern-refining mechanism similar to those acting in embryonic segmentation and compartment boundary formation.