31 research outputs found
Direct transport across the plasma membrane of mammalian cells of Leishmania HASPB as revealed by a CHO export mutant
Leishmania HASPB is a lipoprotein that is exported to the extracellular space from both Leishmania parasites and mammalian cells via an unconventional secretory pathway. Exported HASPB remains anchored in the outer leaflet of the plasma membrane mediated by myristate and palmitate residues covalently attached to the N-terminal SH4 domain of HASPB. HASPB targeting to the plasma membrane depends on SH4 acylation that occurs at intracellular membranes. How acylated HASPB is targeted to the plasma membrane and, in particular, the subcellular site of HASPB membrane translocation is unknown. In order to address this issue, we screened for clonal CHO mutants that are incapable of exporting HASPB. A detailed characterization of such a CHO mutant cell line revealed that the expression level of the HASPB reporter molecule is unchanged compared to CHO wild-type cells; that it is both myristoylated and palmitoylated; and that it is mainly localized to the plasma membrane as judged by confocal microscopy and subcellular fractionation. However, based on a quantitative flow cytometry assay and a biochemical biotinylation assay of surface proteins, HASPB transport to the outer leaflet of the plasma membrane is largely reduced in this mutant. From these data, we conclude that the subcellular site of HASPB membrane translocation is the plasma membrane as the reporter molecule accumulates in this location when export is blocked. Thus, these results allow us to define a two-step process of HASPB cell surface biogenesis in which SH4 acylation of HASPB firstly mediates intracellular targeting to the plasma membrane. In a second step, the plasma membrane-resident machinery, which is apparently disrupted in the CHO mutant cell line, mediates membrane translocation of HASPB. Intriguingly, the angiogenic growth factor FGF-2, another protein secreted by unconventional means, is shown to be secreted normally from the HASPB export mutant cell line. These observations demonstrate that the export machinery component defective in the export mutant cell line functions specifically in the HASPB export pathway
Bienestar en vacas en el preparto durante el verano 2014 en el Departamento Castellanos. Estudio de caso
Durante el verano del 2014 se llevó a cabo un estudio de caso con el objetivo de evaluar algunas respuestas fisiológicas y conductuales preparto y productivas postparto, en vacas lecheras de alto merito genético con acceso a sombras artificiales. Se utilizaron 24 vacas en preparto que se alojaron en un corral seco. Las sombras estaban ubicadas en el área de descanso y en el patio de comida. El peso corporal y la condición corporal fueron evaluadas al inicio y a los 30 dÃas de comenzado el ensayo. La frecuencia respiratoria se midió dos veces por semana en tres momentos del dÃa. El registro de comportamiento una vez a la semana. El peso corporal y condición corporal aumentaron durante este periodo indicando que la combinación de dieta adecuada con la provisión de sombra fue favorable. La frecuencia respiratoria en promedio fue de 60 rpm, indicando un estrés medio alto. La conducta de parado a la sombra fue la de mayor prevalencia. La conducta de comer se mantuvo dentro de los valores considerados normales: 92 minutos. La producción lechera fue de entre 30 y 35 l/d, normal para el establecimiento. El Ãndice de temperatura y humedad se mantuvo por encima de 72. Además, durante febrero las lluvias fueron superiores a las normales de la zona, ocasionado problemas de piso en los corrales.During the summer of 2014 it was carried out a case study in order to evaluate some physiolo-gical and behavioral prepartum and postpartum production in dairy cows of high genetic merit responses with access to artificial shades were used. 24 cows in prepartum they stayed in a dry pen. The shadows were located in the rest area and food court. Body weight and body condition were evaluated at start and 30 days into the trial. The respiratory rate was held twice a week in three times a day. The behavior log once a week. Body weight and body condition gain during this period indicating adequate diet was combined with the provision of shade. The average respiratory rate was 60 rpm, indicating a high middle stress. The conduct of standing in the shadow was the most prevalent. Eating behavior are kept within normal values: 92 minutes. Milk production was between 30 and 35 l / d, normal setting. The temperature and humidity index remained above 72. In addition, during february the rains were above normal in the area, caused problems in floor pensEEA RafaelaFil: Leva, Perla E. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Toneatti, I.E. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Stegmayer, MarÃa Inés. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Ghiano, Jorge Emanuel Jesús. Instituto Nacional de TecnologÃa Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Toffoli, Guillermo D. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Fernández, Guillermo B. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: GarcÃa, MarÃa Soledad. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Sosa, Jorge Luis. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; Argentin
Amygdala and dlPFC abnormalities, with aberrant connectivity and habituation in response to emotional stimuli in females with BPD
Background: Little is known about the frontolimbic abnormalities thought to underlie borderline personality disorder (BPD). We endeavoured to study regional responses, as well as their connectivity and habituation during emotion processing. Methods: 14 BPD patients and 14 normal female controls (NC) controlled for menstrual phase underwent emotion-induction during an fMRI task using standardised images in a block design. We then performed psychophysiological interaction (PPI) analysis to investigate functional connectivity. Results: BPD patients reported more disgust in questionnaires compared to controls. Relative to NC, they showed reduced left amygdala and increased dorsolateral prefrontal cortex (dlPFC) activation to all emotions collapsed versus neutral. Habituation of ventral striatal activity to repeated emotional stimuli was observed in controls but not in BPD. Finally, in the context of disgust (but not other emotions) versus neutral, BPD patients displayed enhanced left amygdala coupling with the dlPFC and ventral striatum. Limitations: Strict inclusion criteria reduced the sample size. Conclusions: In summary, BPD showed abnormal patterns of activation, habituation and connectivity in regions linked to emotion regulation. Amygdala deactivation may be mediated by abnormal top-down regulatory control from the dorsolateral prefrontal cortex. Aberrant emotion processing may play a unique role in the pathophysiology of BPD
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Connectomic markers of disease expression, genetic risk and resilience in bipolar disorder.
Bipolar disorder (BD) is characterized by emotional dysregulation and cognitive deficits associated with abnormal connectivity between subcortical-primarily emotional processing regions-and prefrontal regulatory areas. Given the significant contribution of genetic factors to BD, studies in unaffected first-degree relatives can identify neural mechanisms of genetic risk but also resilience, thus paving the way for preventive interventions. Dynamic causal modeling (DCM) and random-effects Bayesian model selection were used to define and assess connectomic phenotypes linked to facial affect processing and working memory in a demographically matched sample of first-degree relatives carefully selected for resilience (n=25), euthymic patients with BD (n=41) and unrelated healthy controls (n=46). During facial affect processing, patients and relatives showed similarly increased frontolimbic connectivity; resilient relatives, however, evidenced additional adaptive hyperconnectivity within the ventral visual stream. During working memory processing, patients displayed widespread hypoconnectivity within the corresponding network. In contrast, working memory network connectivity in resilient relatives was comparable to that of controls. Our results indicate that frontolimbic dysfunction during affect processing could represent a marker of genetic risk to BD, and diffuse hypoconnectivity within the working memory network a marker of disease expression. The association of hyperconnectivity within the affect-processing network with resilience to BD suggests adaptive plasticity that allows for compensatory changes and encourages further investigation of this phenotype in genetic and early intervention studies
Anatomical integrity within the inferior fronto-occipital fasciculus and semantic processing deficits in schizophrenia spectrum disorders
The core symptoms of schizophrenia spectrum disorders (SSD) include abnormal semantic processing which may rely on the ventral language stream of the human brain. Thus, structural disruption of the ventral language stream may play an important role in semantic deficits observed in SSD patients. Therefore, we compared white matter tract integrity in SSD patients and healthy controls using diffusion tensor imaging combined with probabilistic fiber tractography. For the ventral language stream, we assessed the inferior fronto-occipital fasciculus [IFOF], inferior longitudinal fasciculus, and uncinate fasciculus. The arcuate fasciculus and corticospinal tract were used as control tracts. In SSD patients, the relationship between semantic processing impairments and tract integrity was analyzed separately. Three-dimensional tract reconstructions were performed in 45/44 SSD patients/controls ("Bern sample") and replicated in an independent sample of 24/24 SSD patients/controls ("Basel sample"). Multivariate analyses of fractional anisotropy, mean, axial, and radial diffusivity of the left IFOF showed significant differences between SSD patients and controls (p(FDR-corr) < 0.001, ηp2 = 0.23) in the Bern sample. Axial diffusivity (AD) of the left UF was inversely correlated with semantic impairments (r = -0.454, p(FDR-corr) = 0.035). In the Basel sample, significant group differences for the left IFOF were replicated (p < .01, ηp2 = 0.29), while the correlation between AD of the left IFOF and semantic processing decline (r = -0.376, p = .09) showed a statistical trend. No significant effects were found for the dorsal language stream. This is direct evidence for the importance of the integrity of the ventral language stream, in particular the left IFOF, in semantic processing deficits in SSD