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1.
Pestic Biochem Physiol ; 194: 105492, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37532318

RESUMEN

Nanomaterials have been produced with the use of bio-nanotechnology, which is a low-cost approach. Currently, research is being conducted to determine whether actinomycetes isolated from Egyptian soil can biosynthesize Ag nanoparticles (Ag NPs) and characterized by using the following techniques: Transmission electron microscopy (TEM), Dynamic light scattering (DLS), Fourier transforms infrared (FT-IR), Energy-dispersive X-ray spectroscopy (EDX), UV-Vis spectroscopy and X-ray diffraction (XRD). The most promising actinomycetes isolate were identified, morphologically, biochemically, and molecularly. Streptomyces avermitilis Azhar A.4 was found to be able to reduce silver metal nanoparticles from silver nitrate in nine isolates collected from Egyptian soil. Toxicity of biosynthesized against 2nd and 4th larval instar of Agrotis ipsilon (Hufn.) (Lepidoptera: Noctuidae) was estimated. In addition, activity of certain vital antioxidant and detoxifying enzymes as well as midgut histology of treated larvae were also investigated. The results showed appositive correlations between larval mortality percentage (y) and bio-AgNPs concentrations (x) with excellent (R2). The 4th larval instar was more susceptible than 2nd larval instar with LC50 (with 95% confirmed limits) =8.61 (2.76-13.89) and 26.44(13.25-35.58) ppml-1, respectively of 5 days from treatment. The initial stages of biosynthesized AgNps exposure showed significant increases in carboxylesterase (CarE) and peroxidases (PODs) activity followed by significant suppression after 5 days pos-exposure. While protease activity was significantly decreased by increasing time post-exposure. Midgut histology showed abnormality and progressive damage by increasing time post exposure leading to complete destruction of midgut cells after 5 days from exposure. These results make biosynthesized AgNPs an appropriate alternative to chemical insecticide in A. ipsilon management.


Asunto(s)
Actinobacteria , Nanopartículas del Metal , Animales , Nanopartículas del Metal/toxicidad , Nanopartículas del Metal/química , Actinomyces , Espectroscopía Infrarroja por Transformada de Fourier , Plata/toxicidad , Larva , Extractos Vegetales/farmacología , Antibacterianos/farmacología
2.
Neuroimage ; 230: 117816, 2021 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-33524580

RESUMEN

In early deaf individuals, the auditory deprived temporal brain regions become engaged in visual processing. In our study we tested further the hypothesis that intrinsic functional specialization guides the expression of cross-modal responses in the deprived auditory cortex. We used functional MRI to characterize the brain response to horizontal, radial and stochastic visual motion in early deaf and hearing individuals matched for the use of oral or sign language. Visual motion showed enhanced response in the 'deaf' mid-lateral planum temporale, a region selective to auditory motion as demonstrated by a separate auditory motion localizer in hearing people. Moreover, multivariate pattern analysis revealed that this reorganized temporal region showed enhanced decoding of motion categories in the deaf group, while visual motion-selective region hMT+/V5 showed reduced decoding when compared to hearing people. Dynamic Causal Modelling revealed that the 'deaf' motion-selective temporal region shows a specific increase of its functional interactions with hMT+/V5 and is now part of a large-scale visual motion selective network. In addition, we observed preferential responses to radial, compared to horizontal, visual motion in the 'deaf' right superior temporal cortex region that also show preferential response to approaching/receding sounds in the hearing brain. Overall, our results suggest that the early experience of auditory deprivation interacts with intrinsic constraints and triggers a large-scale reallocation of computational load between auditory and visual brain regions that typically support the multisensory processing of motion information.


Asunto(s)
Estimulación Acústica/métodos , Corteza Auditiva/fisiología , Sordera/fisiopatología , Percepción de Movimiento/fisiología , Estimulación Luminosa/métodos , Localización de Sonidos/fisiología , Adulto , Corteza Auditiva/diagnóstico por imagen , Sordera/diagnóstico por imagen , Diagnóstico Precoz , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino
4.
Environ Sci Pollut Res Int ; 27(12): 13237-13246, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32016872

RESUMEN

The present study was aimed to estimating the effect of Saussurea lappa (costus) root extract on thorium accumulation in different brain regions (cerebral cortex, cerebellum, and hypothalamus) of adult male albino rats and also to evaluate the antioxidant effect and thyroid gland modulation activity of costus following thorium toxicity. Adult male rats were randomly allocated into four groups; control group receiving saline (0.9% NaCl), thorium group receiving an intraperitoneal (i.p.) injection of thorium nitrate (Th; 6.3 mg/kg bwt), costus group receiving an oral administration of costus extract at 200 mg/kg bwt and costus + thorium group receiving costus 1 h before thorium injection. Thorium injection in rats for 28 days resulted in the accumulation of Th maximally in the cerebellum followed by the cerebral cortex and then in the hypothalamus. The accumulation of Th was associated with significant disturbance in sodium and potassium ions. A significant decrease in monoamines was also observed in different brain regions. Furthermore, the results indicated that Th-induced oxidative stress evidenced by increased lipid peroxidation and nitric oxide and decrease the glutathione content. Additionally, Th caused a significant increase in thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) levels in the serum of rats. However, the pre-administration of costus alleviated all of those disturbances. Our results revealed that costus extract exerted its protective effect mainly through potentiating the antioxidant defense system.


Asunto(s)
Saussurea , Animales , Antioxidantes , Masculino , Estrés Oxidativo , Extractos Vegetales , Ratas , Torio
5.
Pregnancy Hypertens ; 17: 54-58, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31487657

RESUMEN

OBJECTIVE: To assess the maternal and fetal outcome in women with mild to moderate chronic hypertension on antihypertensive drug (methyldopa or nifedipine) therapy compared to no medication. METHODS: This multicenter randomized clinical trial was conducted at Menoufia University hospital, Shibin El-kom Teaching hospital and 11 Central hospitals at Menoufia governorate, Egypt.490 pregnant women with mild to moderate chronic hypertension were randomized into three groups; methyldopa group (n = 166), nifedipine group (n = 160) and control or no medication group (n = 164) who were followed from the beginning of pregnancy till the end of puerperium to record maternal and fetal outcome. RESULTS: Mothers in the control (no medication) group were more prone for the development of severe hypertension, preeclampsia, renal impairment, ECG changes, placental abruption and repeated hospital admissions (p < 0.001) when compared to mothers in both treatment groups (methyldopa and nifedipine). Neonates in the control (no medication) group were more prone for prematurity and admission to neonatal ICU (p < 0.001). CONCLUSION: Antihypertensive drug therapy is advisable in mild to moderate chronic hypertension during pregnancy to decrease maternal and fetal morbidity. When considering which agents to use for treatment, oral methyldopa and nifedipine are valid options.


Asunto(s)
Antihipertensivos/uso terapéutico , Hipertensión Inducida en el Embarazo/tratamiento farmacológico , Hipertensión/tratamiento farmacológico , Metildopa/uso terapéutico , Nifedipino/uso terapéutico , Complicaciones Cardiovasculares del Embarazo/tratamiento farmacológico , Administración Oral , Adulto , Antihipertensivos/administración & dosificación , Egipto , Femenino , Humanos , Recién Nacido , Metildopa/administración & dosificación , Nifedipino/administración & dosificación , Embarazo , Diagnóstico Prenatal , Resultado del Tratamiento , Adulto Joven
6.
J Neurosci ; 39(12): 2208-2220, 2019 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-30651333

RESUMEN

The ability to compute the location and direction of sounds is a crucial perceptual skill to efficiently interact with dynamic environments. How the human brain implements spatial hearing is, however, poorly understood. In our study, we used fMRI to characterize the brain activity of male and female humans listening to sounds moving left, right, up, and down as well as static sounds. Whole-brain univariate results contrasting moving and static sounds varying in their location revealed a robust functional preference for auditory motion in bilateral human planum temporale (hPT). Using independently localized hPT, we show that this region contains information about auditory motion directions and, to a lesser extent, sound source locations. Moreover, hPT showed an axis of motion organization reminiscent of the functional organization of the middle-temporal cortex (hMT+/V5) for vision. Importantly, whereas motion direction and location rely on partially shared pattern geometries in hPT, as demonstrated by successful cross-condition decoding, the responses elicited by static and moving sounds were, however, significantly distinct. Altogether, our results demonstrate that the hPT codes for auditory motion and location but that the underlying neural computation linked to motion processing is more reliable and partially distinct from the one supporting sound source location.SIGNIFICANCE STATEMENT Compared with what we know about visual motion, little is known about how the brain implements spatial hearing. Our study reveals that motion directions and sound source locations can be reliably decoded in the human planum temporale (hPT) and that they rely on partially shared pattern geometries. Our study, therefore, sheds important new light on how computing the location or direction of sounds is implemented in the human auditory cortex by showing that those two computations rely on partially shared neural codes. Furthermore, our results show that the neural representation of moving sounds in hPT follows a "preferred axis of motion" organization, reminiscent of the coding mechanisms typically observed in the occipital middle-temporal cortex (hMT+/V5) region for computing visual motion.


Asunto(s)
Corteza Auditiva/fisiología , Localización de Sonidos/fisiología , Estimulación Acústica , Adulto , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Modelos Neurológicos , Adulto Joven
7.
Cereb Cortex ; 29(9): 3590-3605, 2019 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-30272134

RESUMEN

The brain has separate specialized computational units to process faces and voices located in occipital and temporal cortices. However, humans seamlessly integrate signals from the faces and voices of others for optimal social interaction. How are emotional expressions, when delivered by different sensory modalities (faces and voices), integrated in the brain? In this study, we characterized the brains' response to faces, voices, and combined face-voice information (congruent, incongruent), which varied in expression (neutral, fearful). Using a whole-brain approach, we found that only the right posterior superior temporal sulcus (rpSTS) responded more to bimodal stimuli than to face or voice alone but only when the stimuli contained emotional expression. Face- and voice-selective regions of interest, extracted from independent functional localizers, similarly revealed multisensory integration in the face-selective rpSTS only; further, this was the only face-selective region that also responded significantly to voices. Dynamic causal modeling revealed that the rpSTS receives unidirectional information from the face-selective fusiform face area, and voice-selective temporal voice area, with emotional expression affecting the connection strength. Our study promotes a hierarchical model of face and voice integration, with convergence in the rpSTS, and that such integration depends on the (emotional) salience of the stimuli.


Asunto(s)
Encéfalo/fisiología , Emociones/fisiología , Reconocimiento Facial/fisiología , Percepción del Habla/fisiología , Estimulación Acústica , Adulto , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Vías Nerviosas/fisiología , Estimulación Luminosa , Adulto Joven
8.
J Cogn Neurosci ; 30(1): 86-106, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28891782

RESUMEN

Sounds activate occipital regions in early blind individuals. However, how different sound categories map onto specific regions of the occipital cortex remains a matter of debate. We used fMRI to characterize brain responses of early blind and sighted individuals to familiar object sounds, human voices, and their respective low-level control sounds. In addition, sighted participants were tested while viewing pictures of faces, objects, and phase-scrambled control pictures. In both early blind and sighted, a double dissociation was evidenced in bilateral auditory cortices between responses to voices and object sounds: Voices elicited categorical responses in bilateral superior temporal sulci, whereas object sounds elicited categorical responses along the lateral fissure bilaterally, including the primary auditory cortex and planum temporale. Outside the auditory regions, object sounds also elicited categorical responses in the left lateral and in the ventral occipitotemporal regions in both groups. These regions also showed response preference for images of objects in the sighted group, thus suggesting a functional specialization that is independent of sensory input and visual experience. Between-group comparisons revealed that, only in the blind group, categorical responses to object sounds extended more posteriorly into the occipital cortex. Functional connectivity analyses evidenced a selective increase in the functional coupling between these reorganized regions and regions of the ventral occipitotemporal cortex in the blind group. In contrast, vocal sounds did not elicit preferential responses in the occipital cortex in either group. Nevertheless, enhanced voice-selective connectivity between the left temporal voice area and the right fusiform gyrus were found in the blind group. Altogether, these findings suggest that, in the absence of developmental vision, separate auditory categories are not equipotent in driving selective auditory recruitment of occipitotemporal regions and highlight the presence of domain-selective constraints on the expression of cross-modal plasticity.


Asunto(s)
Percepción Auditiva/fisiología , Ceguera/fisiopatología , Encéfalo/fisiología , Encéfalo/fisiopatología , Estimulación Acústica , Adulto , Ceguera/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Estimulación Luminosa , Percepción Visual/fisiología , Adulto Joven
9.
Proc Natl Acad Sci U S A ; 114(31): E6437-E6446, 2017 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-28652333

RESUMEN

Brain systems supporting face and voice processing both contribute to the extraction of important information for social interaction (e.g., person identity). How does the brain reorganize when one of these channels is absent? Here, we explore this question by combining behavioral and multimodal neuroimaging measures (magneto-encephalography and functional imaging) in a group of early deaf humans. We show enhanced selective neural response for faces and for individual face coding in a specific region of the auditory cortex that is typically specialized for voice perception in hearing individuals. In this region, selectivity to face signals emerges early in the visual processing hierarchy, shortly after typical face-selective responses in the ventral visual pathway. Functional and effective connectivity analyses suggest reorganization in long-range connections from early visual areas to the face-selective temporal area in individuals with early and profound deafness. Altogether, these observations demonstrate that regions that typically specialize for voice processing in the hearing brain preferentially reorganize for face processing in born-deaf people. Our results support the idea that cross-modal plasticity in the case of early sensory deprivation relates to the original functional specialization of the reorganized brain regions.


Asunto(s)
Corteza Auditiva/fisiología , Sordera/fisiopatología , Reconocimiento Facial/fisiología , Plasticidad Neuronal/fisiología , Vías Visuales/fisiología , Estimulación Acústica , Adulto , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Neuroimagen/métodos , Estimulación Luminosa , Privación Sensorial/fisiología , Percepción Visual/fisiología
10.
Neuroimage ; 134: 630-644, 2016 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-27107468

RESUMEN

How early blindness reorganizes the brain circuitry that supports auditory motion processing remains controversial. We used fMRI to characterize brain responses to in-depth, laterally moving, and static sounds in early blind and sighted individuals. Whole-brain univariate analyses revealed that the right posterior middle temporal gyrus and superior occipital gyrus selectively responded to both in-depth and laterally moving sounds only in the blind. These regions overlapped with regions selective for visual motion (hMT+/V5 and V3A) that were independently localized in the sighted. In the early blind, the right planum temporale showed enhanced functional connectivity with right occipito-temporal regions during auditory motion processing and a concomitant reduced functional connectivity with parietal and frontal regions. Whole-brain searchlight multivariate analyses demonstrated higher auditory motion decoding in the right posterior middle temporal gyrus in the blind compared to the sighted, while decoding accuracy was enhanced in the auditory cortex bilaterally in the sighted compared to the blind. Analyses targeting individually defined visual area hMT+/V5 however indicated that auditory motion information could be reliably decoded within this area even in the sighted group. Taken together, the present findings demonstrate that early visual deprivation triggers a large-scale imbalance between auditory and "visual" brain regions that typically support the processing of motion information.


Asunto(s)
Corteza Auditiva/fisiopatología , Percepción Auditiva/fisiología , Ceguera/fisiopatología , Percepción de Movimiento/fisiología , Corteza Visual/fisiopatología , Estimulación Acústica , Adulto , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Privación Sensorial , Adulto Joven
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