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1.
Int J Biol Macromol ; 264(Pt 1): 130553, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38431005

RESUMEN

Functional calcium-phosphate-chitosan adsorbents for fluoride (F-) removal from water with different proportions of calcium (0.7 or 1.4 % w/v) were synthesized by: i) ionotropic gelation technique followed by drying in a convection oven (IGA) or freeze drying (FDA); ii) freeze-gelation followed by drying in a convection oven (FGA). Adsorbents were analyzed by SEM-EDX and FTIR- ATR. F- removal percentages higher than 45 % were obtained with calcium-phosphate-chitosan adsorbents for an initial F- concentration of 9.6 mg L-1. Optimal conditions for F- removal were attained, using calcium-phosphate- chitosan adsorbents synthesized by ionotropic gelation with 0.7 % of Ca (IGA0.7). Under these conditions, initial F- concentration of 5 mg L-1, was reduced below the maximum limit of 1.5 mg L-1 established by WHO. Regeneration of IGA0.7 was achieved in acid media. The performance of IGA0.7 was slightly reduced in the presence of coexisting anions (nitrate, carbonate, arsenate). Adsorption kinetics was represented satisfactorily by the pseudo-second order equation; Langmuir isotherm provided the best fit to the equilibrium data and IGA0.7 exhibited a maximum F- adsorption capacity qL = 132.25 mg g-1. IGA0.7 particles were characterized by thermogravimetry coupled to FTIR, XRD, XPS and SEM-EDX. The calcium-phosphate-chitosan adsorbents constitute a suitable and emerging material for water defluorination.


Asunto(s)
Quitosano , Contaminantes Químicos del Agua , Purificación del Agua , Fluoruros , Calcio , Agua , Fosfatos de Calcio , Adsorción , Cinética , Concentración de Iones de Hidrógeno
2.
Aquat Toxicol ; 255: 106397, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36680892

RESUMEN

Pollutants as well as starvation usually modify homeostasis of neutral lipids in aquatic organisms. However, studies on the simultaneous effects of both stressors are scarce. The aim of this study was to evaluate the effect of toxicant exposure under starvation conditions on neutral lipids of the freshwater snail Pomacea canaliculata, selected as the model organism. Starved adult male snails were exposed to sublethal concentration of the pesticide cypermethrin (100 µg/L) during 4 and 10 days. Fed snails were sacrificed at the onset of the experiment (T0), along with starved snails exposed to the pesticide vehicle (ethanol) and another group without solvent served as controls. Total lipid content, neutral lipid classes, fatty acid composition, and pesticide accumulation were determined in the digestive gland of snails. The ethanol concentration used was not an additional stressful agent. As expected, starvation caused a decrease in neutral lipid content in the digestive gland of snails with respect to T0 snails. Pesticide exposure caused, on the other hand, an increase in triacylglycerol content compared to ethanol exposure at day 10 of the bioassay. This increment correlated with the bioconcentration of cypermethrin, which was 47% higher by day 10 than by day 4. The fatty acid profile of triacylglycerols in the digestive gland was significantly altered under starvation and pesticide exposure. Stressed male snails showed the ability to preserve polyunsaturated fatty acids, as evidenced by their significant increase with respect to T0 snails. These results suggest that the alteration of lipid homeostasis could be involved in an adaptive mechanism of aquatic organisms to lipophilic and obesogenic pollutants.


Asunto(s)
Gastrópodos , Plaguicidas , Contaminantes Químicos del Agua , Animales , Masculino , Plaguicidas/toxicidad , Contaminantes Químicos del Agua/toxicidad , Lípidos , Ácidos Grasos
3.
Chemosphere ; 313: 137598, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36549510

RESUMEN

After their application in agricultural areas, pesticides are dispersed throughout the environment, causing contamination problems. In Argentina, the main promoter of transgenic biotechnology in the region, the total consumption of agrochemicals has increased significantly in recent years. Most chemicals dumped near surface waters eventually end up in bottom sediments and can be toxic to the organisms that live there. However, published data on the mixing of pesticides in this compartment is still scarce. The objective of this work was to detect and quantify pesticide residues in the sediment of rural streams in the Pampas region and to carry out acute and chronic risk assessment in these aquatic ecosystems. The study area comprises the mountainous system of Tandilia, located in one of the most productive agricultural areas in the country. The concentration of atrazine, acetochlor, chlorpyrifos, cypermethrin, and 2,4-D in the sediment of four rural streams was determined in three different seasons, and the toxic units (TU) and the risk ratios (RQ) were calculated. All the compounds analyzed were detected in most of the sampling seasons and study sites, at concentrations higher than those established in the national and international quality guidelines for the protection of aquatic biota in surface waters and for human consumption. Chlorpyrifos, cypermethrin, and acetochlor were the main pesticides contributing to the TU and RQ values, representing a medium or high ecological risk in most of the sites. Therefore, the evaluation of these pesticides in the bottom sediments could be a decisive factor in assessing the risk to the aquatic environment.


Asunto(s)
Cloropirifos , Plaguicidas , Contaminantes Químicos del Agua , Humanos , Plaguicidas/análisis , Ecosistema , Ríos/química , Argentina , Contaminantes Químicos del Agua/análisis , Medición de Riesgo , Monitoreo del Ambiente , Sedimentos Geológicos/química
4.
Urologiia ; (6): 40-46, 2021 12.
Artículo en Ruso | MEDLINE | ID: mdl-34967163

RESUMEN

INTRODUCTION: Despite the low invasiveness of percutaneous nephrolithotripsy, this surgery is not without complications. One of the most important stages of the operation, on which depends not only the success of the patient completely getting rid of calculus, but the likelihood of complications, is the puncture of the pelvic-pelvic system. PURPOSE: Determination of the effectiveness and security of the new less-traumatic puncture needle MG under experimental conditions. MATERIALS AND METHODS: A series of pork kidney punctures with a new less-traumatic needle MG and standard Chiba and Troakar needles (Coloplast A/S, Denmark) were performed under experimental conditions, followed by a comparative morphological assessment. The staining of the slides was performed with hematoxylin and eosin. For the purpose of additional assessment of the structures of the kidney punctured with a low-traumatic MG needle, a morphological assessment of the parenchyma stained with picrofuchsin according to Van Gieson was performed. RESULTS: On parenchymal slides with punctures with Chiba and Trocar needles, the passage places with multiple large fragments of desquamated (damaged) epithelium are visualized. On preparations of the parenchyma punctured with a less-traumatic needle MG, the place of passage of the needle is presented with clear contours. The damaged epithelium in the lumen of the formed defect is practically absent. With additional staining according to Van Gieson (magnification x200), the integrity of the full-blooded vessel adjacent to the limited focus of the needle MG was visualized. Output. The new less-traumatic puncture needle MG is an innovative development in urology. The design of the needle with an atraumatic mandrel-bulb atraumatic mandrel-bulb on a spring basis made it possible to significantly reduce the trauma to the structures of the kidney and perirenal tissues due to the bougienage effect.


Asunto(s)
Cálculos Renales , Litotricia , Humanos , Riñón , Agujas , Punciones
5.
J Hazard Mater ; 352: 101-110, 2018 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-29597118

RESUMEN

The potential impact of a technological accident can be assessed by risk estimation. Taking this into account, the latent or potential condition can be warned and mitigated. In this work we propose a methodology to estimate risk of technological hazards, focused on two components. The first one is the processing of meteorological databases to define the most probably and conservative scenario of study, and the second one, is the application of a local social vulnerability index to classify the population. In this case of study, the risk was estimated for a hypothetical release of liquefied ammonia in a meat-packing industry in the city of La Plata, Argentina. The method consists in integrating the simulated toxic threat zone with ALOHA software, and the layer of sociodemographic classification of the affected population. The results show the areas associated with higher risks of exposure to ammonia, which are worth being addressed for the prevention of disasters in the region. Advantageously, this systemic approach is methodologically flexible as it provides the possibility of being applied in various scenarios based on the available information of both, the exposed population and its meteorology. Furthermore, this methodology optimizes the processing of the input data and its calculation.

6.
J Child Neurol ; 31(1): 109-15, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25795464

RESUMEN

Traumatic brain injury is a major public health problem in the pediatric population. Previously, management was acute emergency department/primary care evaluation with follow-up by primary care. However, persistent symptoms after traumatic brain injury are common, and many do not have access to a specialized traumatic brain injury clinic to manage chronic issues. The goal of this study was to determine the factors related to outcomes, and identify the interventions provided in this subspecialty clinic. Data were extracted from medical records of 151 retrospective and 403 prospective patients. Relationships between sequelae, injury characteristics, and clinical interventions were analyzed. Most patients returning to clinic were not fully recovered from their injury. Headaches were more common after milder injuries, and seizures were more common after severe. The majority of patients received clinical intervention. The presence of persistent sequelae for traumatic brain injury patients can be evaluated and managed by a specialty concussion/traumatic brain injury clinic ensuring that medical needs are met.


Asunto(s)
Lesiones Encefálicas/terapia , Resultado del Tratamiento , Adolescente , Adulto , Factores de Edad , Lesiones Encefálicas/diagnóstico , Lesiones Encefálicas/epidemiología , Lesiones Encefálicas/etiología , Niño , Preescolar , Estudios de Cohortes , Registros Electrónicos de Salud/estadística & datos numéricos , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Adulto Joven
7.
AJNR Am J Neuroradiol ; 32(7): 1290-4, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21546460

RESUMEN

BACKGROUND AND PURPOSE: Previous studies evaluating vertebral augmentation procedure costs have not made detailed comparisons between vertebroplasty and kyphoplasty. Our study contrasts hospital costs for vertebroplasty versus kyphoplasty for the treatment of vertebral compression fractures in routine clinical practice in the United States. MATERIALS AND METHODS: This retrospective cohort study analyzed 2007-2008 hospital discharge and billing records from the Premier Perspective data base. The primary outcome variable, differences in total hospital cost between vertebroplasty and kyphoplasty, was assessed by using analysis of covariance. RESULTS: Three thousand six hundred seventeen patients received vertebroplasty (64% inpatient, 36% outpatient), and 8118 received kyphoplasty (54% inpatient, 46% outpatient). Approximately 75% were women, and most were white. Mean total unadjusted inpatient costs were $9837 for vertebroplasty versus $13 187 for kyphoplasty (P < .0001). Outpatient vertebroplasty costs were $3319 versus $8100 for kyphoplasty (P < .0001). Lower vertebroplasty costs were largely due to differences in hospital supply and OR. Mean vertebroplasty OR costs were $73.60 (anesthesia), $112.06 (recovery room), and $990.12 (surgery) versus $172.16 (anesthesia), $257.47 (recovery room), and $1,471.49 (surgery) with kyphoplasty. Adjustments for age, sex, admission status, and disease severity accentuated the differences. Mean adjusted inpatient costs were $11 386 for vertebroplasty versus $16 182 for kyphoplasty (P < .0001), and outpatient costs were $2997 for vertebroplasty versus $7010 for kyphoplasty (P < .0001). After adjustments for the same covariates, length-of-stay differences were no longer evident (P = .4945). CONCLUSIONS: Performing vertebroplasty versus kyphoplasty reduces hospital costs by nearly $5000 for inpatient procedures and by more than $4000 for outpatient procedures.


Asunto(s)
Fracturas por Compresión/economía , Costos de Hospital/estadística & datos numéricos , Cifoplastia/economía , Fracturas de la Columna Vertebral/economía , Vertebroplastia/economía , Enfermedad Aguda , Anciano , Procedimientos Quirúrgicos Ambulatorios/economía , Procedimientos Quirúrgicos Ambulatorios/estadística & datos numéricos , Estudios de Cohortes , Ahorro de Costo/economía , Ahorro de Costo/estadística & datos numéricos , Bases de Datos Factuales/estadística & datos numéricos , Femenino , Fracturas por Compresión/epidemiología , Fracturas por Compresión/cirugía , Capacidad de Camas en Hospitales/economía , Capacidad de Camas en Hospitales/estadística & datos numéricos , Humanos , Pacientes Internos/estadística & datos numéricos , Cifoplastia/estadística & datos numéricos , Tiempo de Internación/economía , Tiempo de Internación/estadística & datos numéricos , Masculino , Pacientes Ambulatorios/estadística & datos numéricos , Estudios Retrospectivos , Fracturas de la Columna Vertebral/epidemiología , Fracturas de la Columna Vertebral/cirugía , Estados Unidos/epidemiología , Vertebroplastia/estadística & datos numéricos
8.
Neurology ; 75(19): 1686-94, 2010 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-20926787

RESUMEN

BACKGROUND: Fast ripples (FR, 250-500 Hz) detected with chronic intracranial electrodes are proposed biomarkers of epileptogenesis. This study determined whether resection of FR-containing neocortex recorded during intraoperative electrocorticography (ECoG) was associated with postoperative seizure freedom in pediatric patients with mostly extratemporal lesions. METHODS: FRs were retrospectively reviewed in 30 consecutive pediatric cases. ECoGs were recorded at 2,000 Hz sampling rate and visually inspected for FR, with reviewer blinded to the resection and outcome. RESULTS: Average age at surgery was 9.1 ± 6.7 years, ECoG duration was 11.8 ± 8.1 minutes, and postoperative follow-up was 27 ± 4 months. FRs were undetected in 6 ECoGs with remote or extensive lesions. FR episodes (n = 273) were identified in ECoGs from 24 patients, and in 64% FRs were independent of spikes, sharp waves, voltage attenuation, and paroxysmal fast activity. Of these 24 children, FR-containing cortex was removed in 19 and all became seizure-free, including 1 child after a second surgery. The remaining 5 children had incomplete FR resection and all continued with seizures postoperatively. In 2 ECoGs, the location of electrographic seizures matched FR location. FR-containing cortex was found outside of MRI and FDG-PET abnormalities in 6 children. CONCLUSION: FRs were detected during intraoperative ECoG in 80% of pediatric epilepsy cases, and complete resection of FR cortex correlated with postoperative seizure freedom. These findings support the view that interictal FRs are excellent surrogate markers of epileptogenesis, can be recorded during brief ECoG, and could be used to guide future surgical resections in children.


Asunto(s)
Electroencefalografía/métodos , Monitoreo Intraoperatorio/métodos , Convulsiones/fisiopatología , Adolescente , Factores de Edad , Niño , Preescolar , Electrodos Implantados/normas , Electroencefalografía/normas , Epilepsia/diagnóstico , Epilepsia/fisiopatología , Epilepsia/cirugía , Femenino , Humanos , Lactante , Masculino , Monitoreo Intraoperatorio/normas , Tomografía de Emisión de Positrones/métodos , Estudios Prospectivos , Estudios Retrospectivos , Convulsiones/diagnóstico , Convulsiones/cirugía , Adulto Joven
9.
Neurology ; 74(22): 1768-75, 2010 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-20427752

RESUMEN

OBJECTIVE: Epilepsy neurosurgery is a treatment option for children with refractory epilepsy. Our aim was to determine if outcomes improved over time. METHODS: Pediatric epilepsy surgery patients operated in the first 11 years (1986-1997; pre-1997) were compared with the second 11 years (1998-2008; post-1997) for differences in presurgical and postsurgical variables. RESULTS: Despite similarities in seizure frequency, age at seizure onset, and age at surgery, the post-1997 series had more lobar/focal and fewer multilobar resections, and more patients with tuberous sclerosis complex and fewer cases of nonspecific gliosis compared with the pre-1997 group. Fewer cases had intracranial EEG studies in the post-1997 (0.8%) compared with the pre-1997 group (9%). Compared with the pre-1997 group, the post-1997 series had more seizure-free patients at 0.5 (83%, +16%), 1 (81%, +18%), 2 (77%, +19%), and 5 (74%, +29%) years, and more seizure-free patients were on medications at 0.5 (97%, +6%), 1 (88%, +9%), and 2 (76%, +29%), but not 5 (64%, +8%) years after surgery. There were fewer complications and reoperations in the post-1997 series compared with the pre-1997 group. Logistic regression identified post-1997 series and less aggressive medication withdrawal as the main predictors of becoming seizure-free 2 years after surgery. CONCLUSIONS: Improved technology and surgical procedures along with changes in clinical practice were likely factors linked with enhanced and sustained seizure-free outcomes in the post-1997 series. These findings support the general concept that clearer identification of lesions and complete resection are linked with better outcomes in pediatric epilepsy surgery patients.


Asunto(s)
Epilepsia/cirugía , Procedimientos Neuroquirúrgicos/métodos , Pediatría , Resultado del Tratamiento , Centros Médicos Académicos/estadística & datos numéricos , Adolescente , Adulto , Anticonvulsivantes/uso terapéutico , California , Niño , Epilepsia/tratamiento farmacológico , Femenino , Humanos , Masculino , Análisis Multivariante , Complicaciones Posoperatorias , Estudios Retrospectivos , Adulto Joven
10.
Clin Pharmacol Ther ; 88(2): 204-13, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20164833

RESUMEN

Glioblastoma multiforme (GBM) is the most common and most aggressive primary brain tumor in humans. Systemic immunity against gene therapy vectors has been shown to hamper therapeutic efficacy; however, helper-dependent high-capacity adenovirus (HC-Ad) vectors elicit sustained transgene expression, even in the presence of systemic anti-adenoviral immunity. We engineered HC-Ads encoding the conditional cytotoxic herpes simplex type 1 thymidine kinase (TK) and the immunostimulatory cytokine fms-like tyrosine kinase ligand 3 (Flt3L). Flt3L expression is under the control of the regulatable Tet-ON system. In anticipation of a phase I clinical trial for GBM, we assessed the therapeutic efficacy, biodistribution, and clinical and neurotoxicity with escalating doses of HC-Ad-TetOn-Flt3L + HC-Ad-TK in rats. Intratumoral administration of these therapeutic HC-Ads in rats bearing large intracranial GBMs led to long-term survival in approximately 70% of the animals and development of antiglioma immunological memory without signs of neuropathology or systemic toxicity. Systemic anti-adenoviral immunity did not affect therapeutic efficacy. These data support the idea that it would be useful to develop HC-Ad vectors further as a therapeutic gene-delivery platform to implement GBM phase I clinical trials.


Asunto(s)
Adenoviridae/genética , Neoplasias Encefálicas/terapia , Vectores Genéticos/farmacocinética , Vectores Genéticos/uso terapéutico , Glioblastoma/terapia , Adenoviridae/inmunología , Adyuvantes Inmunológicos/uso terapéutico , Animales , Conducta Animal , Neoplasias Encefálicas/psicología , Ensayos Clínicos Fase I como Asunto , Relación Dosis-Respuesta Inmunológica , Dosificación de Gen , Terapia Genética , Vectores Genéticos/efectos adversos , Glioblastoma/psicología , Humanos , Inmunohistoquímica , Inyecciones , Trasplante de Neoplasias , Ratas , Análisis de Supervivencia , Distribución Tisular , Transgenes/genética
11.
Exp Suppl ; 102: 183-94, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21299069

RESUMEN

Neuroanatomical localization and physiological properties of galanin suggest that the peptide may be involved in the regulation of seizures. Indeed, administration of galanin receptor agonists into brain areas pertinent to the initiation and propagation of epileptic activity attenuated seizure responses under conditions of animal models of epilepsy; pharmacological blocking of galanin receptors exerted proconvulsant effects. Functional deletion of both galanin and galanin type 1 receptor genes produced transgenic mice with either spontaneous seizure phenotype, or with enhanced susceptibility to seizure stimuli. At the same time, overexpression of galanin in seizure pathways, using both transgenic and virus vector transfection techniques, hindered the epileptic process. Galanin exerts anticonvulsant effects through both type 1 and type 2 receptors, with distinct downstream signaling cascades. Several synthetic agonists of galanin receptors with optimized bioavailability have been synthesized and inhibited experimental seizures upon systemic administration, thus opening an opportunity for the development of galanin-based antiepileptic drugs.


Asunto(s)
Epilepsia del Lóbulo Temporal/fisiopatología , Galanina/fisiología , Animales , Anticonvulsivantes/uso terapéutico , Epilepsia del Lóbulo Temporal/tratamiento farmacológico , Ratones , Ratones Transgénicos , Receptores de Galanina/genética , Receptores de Galanina/fisiología , Transducción de Señal
12.
Neurology ; 71(20): 1594-601, 2008 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-19001249

RESUMEN

OBJECTIVE: Patients with cortical dysplasia (CD) are difficult to treat because the MRI abnormality may be undetectable. This study determined whether fluorodeoxyglucose (FDG)-PET/MRI coregistration enhanced the recognition of CD in epilepsy surgery patients. METHODS: Patients from 2004-2007 in whom FDG-PET/MRI coregistration was a component of the presurgical evaluation were compared with patients from 2000-2003 without this technique. For the 2004-2007 cohort, neuroimaging and clinical variables were compared between patients with mild Palmini type I and severe Palmini type II CD. RESULTS: Compared with the 2000-2003 cohort, from 2004-2007 more CD patients were detected, most had type I CD, and fewer cases required intracranial electrodes. From 2004-2007, 85% of type I CD cases had normal non-University of California, Los Angeles (UCLA) MRI scans. UCLA MRI identified CD in 78% of patients, and 37% of type I CD cases had normal UCLA scans. EEG and neuroimaging findings were concordant in 52% of type I CD patients, compared with 89% of type II CD patients. FDG-PET scans were positive in 71% of CD cases, and type I CD patients had less hypometabolism compared with type II CD patients. Postoperative seizure freedom occurred in 82% of patients, without differences between type I and type II CD cases. CONCLUSIONS: Incorporating fluorodeoxyglucose-PET/MRI coregistration into the multimodality presurgical evaluation enhanced the noninvasive identification and successful surgical treatment of patients with cortical dysplasia (CD), especially for the 33% of patients with nonconcordant findings and those with normal MRI scans from mild type I CD.


Asunto(s)
Epilepsia/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Imagen por Resonancia Magnética , Malformaciones del Desarrollo Cortical , Tomografía de Emisión de Positrones , Adolescente , Adulto , Mapeo Encefálico , Niño , Preescolar , Estudios de Cohortes , Electroencefalografía/métodos , Epilepsia/complicaciones , Epilepsia/patología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Lactante , Masculino , Malformaciones del Desarrollo Cortical/complicaciones , Malformaciones del Desarrollo Cortical/diagnóstico por imagen , Malformaciones del Desarrollo Cortical/patología , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
13.
Cell Mol Life Sci ; 65(12): 1864-71, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18500639

RESUMEN

Neuroanatomical localization and physiological properties of galanin suggest that the peptide may be involved in the regulation of seizures. Indeed, administration of galanin receptor agonists into brain areas pertinent to the initiation and propagation of epileptic activity attenuated seizure responses under conditions of animal models of epilepsy; pharmacological blocking of galanin receptors exerted proconvulsant effects. Functional deletion of both galanin and galanin type 1 receptor genes produced transgenic mice with either spontaneous seizure phenotype, or with enhanced susceptibility to seizure stimuli. At the same time, overexpression of galanin in seizure pathways, using both transgenic and virus vector transfection techniques, hindered the epileptic process. Galanin exerts anticonvulsant effects through both type 1 and type 2 receptors, with distinct downstream signaling cascades. Several synthetic agonists of galanin receptors with optimized bioavailability have been synthesized and inhibited experimental seizures upon systemic administration, thus opening an opportunity for the development of galanin-based antiepileptic drugs.


Asunto(s)
Epilepsia/etiología , Galanina/fisiología , Animales , Anticonvulsivantes/farmacología , Anticonvulsivantes/uso terapéutico , Epilepsia/tratamiento farmacológico , Epilepsia/metabolismo , Epilepsia del Lóbulo Temporal/etiología , Galanina/farmacología , Hipocampo/metabolismo , Ratones , Ratas , Receptores de Galanina/agonistas , Receptores de Galanina/fisiología , Transducción de Señal
14.
J Parasitol ; 87(5): 1167-8, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11695386

RESUMEN

Recent successes in culturing intramolluscan larval stages of Schistosoma mansoni have relied on synxenic culture with a cell line (Bge) developed from embryos of a molluscan host Biomphalaria glabrata. To further facilitate progress toward control of schistosomiasis, a system for axenic in vitro culture of the parasite has now been developed. When culture media were preconditioned by Bge cells, sporocysts lived longer in vitro and produced more offspring. Because Bge-derived components could be protecting sporocysts from oxidative stress, axenic sporocysts were cultured at lowered O2 levels. In an hypoxic environment, S. mansoni sporocysts grew well and produced daughter sporocysts continuously under axenic conditions and in a medium completely lacking host molecules. Sporocyst production occurs independently of host influence.


Asunto(s)
Biomphalaria/parasitología , Oxígeno , Schistosoma mansoni/crecimiento & desarrollo , Animales , Técnicas de Cultivo de Célula/métodos , Técnicas de Cocultivo , Medios de Cultivo Condicionados , Femenino , Nitrógeno , Schistosoma mansoni/citología
17.
Pharmacol Biochem Behav ; 69(3-4): 629-34, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11509225

RESUMEN

Recent findings have demonstrated that Fawn hooded (FH/Har) rats exhibit enhanced plasma corticosterone (CORT) responses compared to Wistar rats after exposure to an open field, whereas this effect was not influenced by early social experience. In contrast, it was found that behavior in a modified version of the Porsolt Forced Swim Test (Porsolt FST) was affected by both strain and social experience. An important part of this study included modifications of the Porsolt FST that allowed separation of multiple behavioral endpoints. The present experiment was conducted to determine if FH/Har rats also exhibit enhanced CORT responses after exposure to the modified forced swim test, and whether CORT levels might predict the behavioral response in this context. After the initial exposure in the modified forced swim test FH/Har rats had higher CORT levels than Wistar rats, but this difference was not affected by isolation rearing. However, CORT levels were not correlated with the main behavioral measures assayed in this test. Nonetheless, the data confirm that FH/Har rats have altered HPA axis responses to stressors.


Asunto(s)
Conducta Animal/fisiología , Corticosterona/sangre , Estrés Fisiológico/sangre , Animales , Masculino , Ratas , Ratas Wistar , Aislamiento Social/psicología , Especificidad de la Especie , Natación/psicología
18.
J Pers Soc Psychol ; 81(1): 146-59, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11474720

RESUMEN

Drawing on an appraisal-tendency framework (J. S. Lerner & D. Keltner, 2000), the authors predicted and found that fear and anger have opposite effects on risk perception. Whereas fearful people expressed pessimistic risk estimates and risk-averse choices, angry people expressed optimistic risk estimates and risk-seeking choices. These opposing patterns emerged for naturally occurring and experimentally induced fear and anger. Moreover, estimates of angry people more closely resembled those of happy people than those of fearful people. Consistent with predictions, appraisal tendencies accounted for these effects: Appraisals of certainty and control moderated and (in the case of control) mediated the emotion effects. As a complement to studies that link affective valence to judgment outcomes, the present studies highlight multiple benefits of studying specific emotions.


Asunto(s)
Ira , Conducta de Elección , Miedo/psicología , Asunción de Riesgos , Adulto , Toma de Decisiones , Femenino , Humanos , Masculino , Escalas de Valoración Psiquiátrica , Riesgo , Estados Unidos
19.
Plant Dis ; 85(9): 1031, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30823100

RESUMEN

Commercial plantings of summer squash in Charlemont, Franklin County, MA, were decimated in 1999 by 100% incidence of a yellowing disease resembling cucurbit yellow vine disease (CYVD) (1). Both plantings were established in the same field during the third week of May, one with transplants and the second by direct-seeding. Each planting consisted of four 30-m rows each of yellow zucchini (Cucurbita pepo cv. Gold Rush), summer squash (C. pepo cv. Seneca Prolific), and zucchini (C. pepo cv. Condor). Crops were produced organically and pyrethrum was used to control a high infestation of squash bugs, Anasa tristis (De Geer) (Heteroptera:Coreidae), a putative vector of CYVD (3). Just prior to fruit set, during the first two weeks of June, plants began showing symptoms of foliar chlorosis, plant stunting, or both. All of the plants in the field eventually wilted and collapsed. Cross-sections of the below-ground stem and primary root revealed a honey-brown phloem discoloration and healthy appearing xylem, symptoms characteristic of CYVD. Plants yielded marketable fruit for only about 1 week. When plant samples were tested by polymerase chain reaction (PCR) with CYVD bacterium specific primers (2), a band of the expected size for the CYVD bacterium, identified as Serratia marcescens based on 16s rDNA and groE sequence analyses (4), was amplified in every case. Since all plant samples collected were symptomatic and PCR positive for S. marcescens, asymptomatic greenhouse plants were run simultaneously as a control. All control plants tested negative. A third planting, similar to the two disease-affected plantings and containing the same three squash cultivars from the same seed lot, was established at about the same time approximately 3 km away. No symptoms of CYVD occurred at this site, further evidence that the pathogen is not seed-borne (1). Furthermore, squash bugs were not observed in this field. In 2000, the disease was observed in a planting of 'Atlantic Giant' pumpkin in Erving, Franklin County, MA, and confirmed by PCR. Until now, CYVD has been reported only in the states of Oklahoma, Texas, and Tennessee. Confirmation of the disease in Massachusetts significantly increases the known geographical range of CYVD to include the New England area. References: (1) B. D. Bruton et al. Plant Dis. 82:512-520, 1998. (2) U. Melcher et al. Phytopathology 89:S95, 1999. (3) S. D. Pair et al. Pages 145-148 in: Proc. 19th Ann. Hort. Conf., Okla. State Univ. (4) J. Rascoe et al. Phytopathology 90:S63, 2000.

20.
Physiol Biochem Zool ; 73(3): 307-12, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10893170

RESUMEN

Over a 2-yr period, we investigated the annual cycles of plasma testosterone and corticosterone and the relationships between these hormones and body condition in a wild population of male red-spotted garter snakes, Thamnophis sirtalis concinnus. In the 10 mo that were sampled, a peak in testosterone was observed in late summer during gametogenesis and declining through the spring breeding period. Corticosterone and testosterone cycles were positively correlated, in contrast to many vertebrates, suggesting the lack of a direct negative interaction between the two hormones. Body condition, defined as the residual of the regression of mass on snout-vent length, also cycled annually, with individuals being more robust during the summer than during the spring or fall. Individuals with a positive body condition had significantly lower plasma levels of corticosterone than did individuals with a negative body condition, supporting the energetic role of glucocorticoids. There was no relationship between body condition and testosterone. This study suggests that annual cycles of testosterone, corticosterone, and body condition can be associated with one another, and considering all three simultaneously is necessary to understand their control and function.


Asunto(s)
Composición Corporal , Corticosterona/análisis , Serpientes/fisiología , Testosterona/análisis , Animales , Masculino , Reproducción/fisiología , Estaciones del Año , Espermatogénesis/fisiología
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