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1.
PLoS Biol ; 21(7): e3002210, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37486945

RESUMEN

1p32.3 microdeletion/duplication is implicated in many neurodevelopmental disorders-like phenotypes such as developmental delay, intellectual disability, autism, macro/microcephaly, and dysmorphic features. The 1p32.3 chromosomal region harbors several genes critical for development; however, their validation and characterization remain inadequate. One such gene is the single-stranded DNA-binding protein 3 (SSBP3) and its Drosophila melanogaster ortholog is called sequence-specific single-stranded DNA-binding protein (Ssdp). Here, we investigated consequences of Ssdp manipulations on neurodevelopment, gene expression, physiological function, and autism-associated behaviors using Drosophila models. We found that SSBP3 and Ssdp are expressed in excitatory neurons in the brain. Ssdp overexpression caused morphological alterations in Drosophila wing, mechanosensory bristles, and head. Ssdp manipulations also affected the neuropil brain volume and glial cell number in larvae and adult flies. Moreover, Ssdp overexpression led to differential changes in synaptic density in specific brain regions. We observed decreased levels of armadillo in the heads of Ssdp overexpressing flies, as well as a decrease in armadillo and wingless expression in the larval wing discs, implicating the involvement of the canonical Wnt signaling pathway in Ssdp functionality. RNA sequencing revealed perturbation of oxidative stress-related pathways in heads of Ssdp overexpressing flies. Furthermore, Ssdp overexpressing brains showed enhanced reactive oxygen species (ROS), altered neuronal mitochondrial morphology, and up-regulated fission and fusion genes. Flies with elevated levels of Ssdp exhibited heightened anxiety-like behavior, altered decisiveness, defective sensory perception and habituation, abnormal social interaction, and feeding defects, which were phenocopied in the pan-neuronal Ssdp knockdown flies, suggesting that Ssdp is dosage sensitive. Partial rescue of behavioral defects was observed upon normalization of Ssdp levels. Notably, Ssdp knockdown exclusively in adult flies did not produce behavioral and functional defects. Finally, we show that optogenetic manipulation of Ssdp-expressing neurons altered autism-associated behaviors. Collectively, our findings provide evidence that Ssdp, a dosage-sensitive gene in the 1p32.3 chromosomal region, is associated with various anatomical, physiological, and behavioral defects, which may be relevant to neurodevelopmental disorders like autism. Our study proposes SSBP3 as a critical gene in the 1p32.3 microdeletion/duplication genomic region and sheds light on the functional role of Ssdp in neurodevelopmental processes in Drosophila.


Asunto(s)
Trastorno Autístico , Proteínas de Drosophila , Factores de Transcripción , Animales , Humanos , Armadillos/metabolismo , Trastorno Autístico/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
2.
EMBO J ; 40(14): e106111, 2021 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-34018220

RESUMEN

Mycobacterium tuberculosis (Mtb) has evolved diverse cellular processes in response to the multiple stresses it encounters within the infected host. We explored available TnSeq datasets to identify transcription factors (TFs) that are essential for Mtb survival inside the host. The analysis identified a single TF, Rv1332 (AosR), conserved across actinomycetes with a so-far uncharacterized function. AosR mitigates phagocyte-derived oxidative and nitrosative stress, thus promoting mycobacterial growth in the murine lungs and spleen. Oxidative stress induces formation of a single intrasubunit disulphide bond in AosR, which in turn facilitates AosR interaction with an extracytoplasmic-function sigma factor, SigH. This leads to the specific upregulation of the CysM-dependent non-canonical cysteine biosynthesis pathway through an auxiliary intragenic stress-responsive promoter, an axis critical in detoxifying host-derived oxidative and nitrosative radicals. Failure to upregulate AosR-dependent cysteine biosynthesis during the redox stress causes differential expression of 6% of Mtb genes. Our study shows that the AosR-SigH pathway is critical for detoxifying host-derived oxidative and nitrosative radicals to enhance Mtb survival in the hostile intracellular environment.


Asunto(s)
Actinobacteria/genética , Homeostasis/genética , Mycobacterium tuberculosis/genética , Factores de Transcripción/genética , Animales , Proteínas Bacterianas/genética , Femenino , Regulación Bacteriana de la Expresión Génica/genética , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Oxidación-Reducción , Estrés Oxidativo/genética , Regiones Promotoras Genéticas/genética , Factor sigma/genética , Transcripción Genética/genética
3.
PLoS Pathog ; 19(2): e1011147, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36780551

RESUMEN

Host-specific plant pathogens must coordinate their life cycles with the availability of a host plant. Although this is frequently achieved through a response to specific chemical cues derived from the host plant, little is known about the molecular basis of the response to such cues and how these are used to trigger activation of the life cycle. In host-specific plant-parasitic cyst nematodes, unhatched juvenile nematodes lie dormant in the eggshell until chemical cues from a suitable host plant are detected and the hatching process is initiated. The molecular mechanisms by which hatch is linked to the presence of these chemical cues is unknown. We have identified a novel annexin-like protein that is localised to the eggshell of the potato cyst nematode Globodera rostochiensis. This annexin is unique in having a short peptide insertion that structural modelling predicts is present in one of the calcium-binding sites of this protein. Host-induced gene silencing of the annexin impacts the ability of the nematode to regulate and control permeability of the eggshell. We show that in the presence of the chemicals that induce hatching annexin lipid binding capabilities change, providing the first molecular link between a nematode eggshell protein and host-derived cues. This work demonstrates how a protein from a large family has been recruited to play a critical role in the perception of the presence of a host and provides a new potential route for control of cyst nematodes that impact global food production.


Asunto(s)
Parásitos , Tylenchoidea , Animales , Anexinas , Cáscara de Huevo , Plantas , Estadios del Ciclo de Vida
4.
J Neurosci Res ; 102(4): e25332, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38646942

RESUMEN

The coordinated action of multiple leg joints and muscles is required even for the simplest movements. Understanding the neuronal circuits and mechanisms that generate precise movements is essential for comprehending the neuronal basis of the locomotion and to infer the neuronal mechanisms underlying several locomotor-related diseases. Drosophila melanogaster provides an excellent model system for investigating the neuronal circuits underlying motor behaviors due to its simple nervous system and genetic accessibility. This review discusses current genetic methods for studying locomotor circuits and their function in adult Drosophila. We highlight recently identified neuronal pathways that modulate distinct forward and backward locomotion and describe the underlying neuronal control of leg swing and stance phases in freely moving flies. We also report various automated leg tracking methods to measure leg motion parameters and define inter-leg coordination, gait and locomotor speed of freely moving adult flies. Finally, we emphasize the role of leg proprioceptive signals to central motor circuits in leg coordination. Together, this review highlights the utility of adult Drosophila as a model to uncover underlying motor circuitry and the functional organization of the leg motor system that governs correct movement.


Asunto(s)
Locomoción , Animales , Locomoción/fisiología , Neuronas/fisiología , Drosophila melanogaster/fisiología , Drosophila/fisiología
5.
BMC Psychiatry ; 24(1): 61, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38254016

RESUMEN

BACKGROUND: In light of several recent studies, there is evidence that the coronavirus disease 2019 (COVID-19) pandemic has caused various mental health concerns in the general population, as well as among healthcare workers (HCWs). The main aim of this study was to assess the psychological distress, burnout and structural empowerment status of HCWs during the COVID-19 outbreak, and to evaluate its predictors. METHODS: This multi-center, cross-sectional web-based questionnaire survey was conducted on HCWs during the outbreak of COVID-19 from August 2020 to January 2021. HCWs working in hospitals from 48 different countries were invited to participate in an online anonymous survey that investigated sociodemographic data, psychological distress, burnout and structural empowerment (SE) based on Depression Anxiety and Stress Scale 21 (DASS-21), Maslach Burnout Inventory (MBI) and Conditions for work effectiveness questionnaire (CWEQ_II), respectively. Predictors of the total scores of DASS-21, MBI and CWEQ-II were assessed using unadjusted and adjusted binary logistic regression analysis. RESULTS: Out of the 1030 HCWs enrolled in this survey, all completed the sociodemographic section (response rate 100%) A total of 730 (70.9%) HCWs completed the DASS-21 questionnaire, 852 (82.6%) completed the MBI questionnaire, and 712 (69.1%) completed the CWEQ-II questionnaire. The results indicate that 360 out of 730 responders (49.3%) reported severe or extremely severe levels of stress, anxiety, and depression. Additionally, 422 out of 851 responders (49.6%) reported a high level of burnout, while 268 out of 712 responders (37.6%) reported a high level of structural empowerment based on the DASS-21, MBI, and CWEQ-II scales, respectively. In addition, the analysis showed that HCWs working in the COVID-19 areas experienced significantly higher symptoms of severe stress, anxiety, depression and higher levels of burnout compared to those working in other areas. The results also revealed that direct work with COVID-19 patients, lower work experience, and high workload during the outbreak of COVID-19 increase the risks of negative psychological consequences. CONCLUSION: Health professionals had high levels of burnout and psychological symptoms during the COVID-19 emergency. Monitoring and timely treatment of these conditions is needed.


Asunto(s)
COVID-19 , Distrés Psicológico , Pruebas Psicológicas , Humanos , Estudios Transversales , COVID-19/epidemiología , Agotamiento Psicológico , Brotes de Enfermedades , Personal de Salud , Autoinforme
6.
J Neurophysiol ; 130(5): 1252-1264, 2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37823212

RESUMEN

When human subjects tilt their heads in dark surroundings, the noisiness of vestibular information impedes precise reports on objects' orientation with respect to Earth's vertical axis. This difficulty is mitigated if a vertical visual background is available. Tilted visual backgrounds induce feelings of head tilt in subjects who are in fact upright. This is often explained as a result of the brain resorting to the prior assumption that natural visual backgrounds are vertical. Here, we tested whether monkeys show comparable perceptual mechanisms. To this end we trained two monkeys to align a visual arrow to a vertical reference line that had variable luminance across trials, while including a large, clearly visible background square whose orientation changed from trial to trial. On ∼20% of all trials, the vertical reference line was left out to measure the subjective visual vertical (SVV). When the frame was upright, the monkeys' SVV was aligned with the gravitational vertical. In accordance with the perceptual reports of humans, however, when the frame was tilted it induced an illusion of head tilt as indicated by a bias in SVV toward the frame orientation. Thus all primates exploit the prior assumption that the visual world is vertical.NEW & NOTEWORTHY Here we show that the principles that characterize the human perception of the vertical are shared by another old world primate species, the rhesus monkey, suggesting phylogenetic continuity. In both species the integration of visual and vestibular information on the orientation of the head relative to the world is similarly constrained by the prior assumption that the visual world is vertical in the sense of having an orientation that is congruent with the gravity vector.


Asunto(s)
Percepción Espacial , Vestíbulo del Laberinto , Animales , Humanos , Filogenia , Orientación , Encéfalo , Percepción Visual
7.
BMC Med ; 21(1): 36, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36726141

RESUMEN

BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF) is a widespread disease transmitted to humans and livestock animals through the bite of infected ticks or close contact with infected persons' blood, organs, or other bodily fluids. The virus is responsible for severe viral hemorrhagic fever outbreaks, with a case fatality rate of up to 40%. Despite having the highest fatality rate of the virus, a suitable treatment option or vaccination has not been developed yet. Therefore, this study aimed to formulate a multiepitope vaccine against CCHF through computational vaccine design approaches. METHODS: The glycoprotein, nucleoprotein, and RNA-dependent RNA polymerase of CCHF were utilized to determine immunodominant T- and B-cell epitopes. Subsequently, an integrative computational vaccinology approach was used to formulate a multi-epitopes vaccine candidate against the virus. RESULTS: After rigorous assessment, a multiepitope vaccine was constructed, which was antigenic, immunogenic, and non-allergenic with desired physicochemical properties. Molecular dynamics (MD) simulations of the vaccine-receptor complex show strong stability of the vaccine candidates to the targeted immune receptor. Additionally, the immune simulation of the vaccine candidates found that the vaccine could trigger real-life-like immune responses upon administration to humans. CONCLUSIONS: Finally, we concluded that the formulated multiepitope vaccine candidates would provide excellent prophylactic properties against CCHF.


Asunto(s)
Virus de la Fiebre Hemorrágica de Crimea-Congo , Fiebre Hemorrágica de Crimea , Vacunas Virales , Humanos , Animales , Fiebre Hemorrágica de Crimea/prevención & control , Fiebre Hemorrágica de Crimea/epidemiología , Virus de la Fiebre Hemorrágica de Crimea-Congo/genética , Brotes de Enfermedades/prevención & control , Vacunación
8.
Proc Natl Acad Sci U S A ; 117(31): 18799-18809, 2020 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-32680968

RESUMEN

We try to deploy the retinal fovea to optimally scrutinize an object of interest by directing our eyes to it. The horizontal and vertical components of eye positions acquired by goal-directed saccades are determined by the object's location. However, the eccentric eye positions also involve a torsional component, which according to Donder's law is fully determined by the two-dimensional (2D) eye position acquired. According to von Helmholtz, knowledge of the amount of torsion provided by Listing's law, an extension of Donder's law, alleviates the perceptual interpretation of the image tilt that changes with 2D eye position, a view supported by psychophysical experiments he pioneered. We address the question of where and how Listing's law is implemented in the visual system and we show that neurons in monkey area V1 use knowledge of eye torsion to compensate the image tilt associated with specific eye positions as set by Listing's law.


Asunto(s)
Movimientos Oculares/fisiología , Neuronas/fisiología , Corteza Visual , Animales , Macaca mulatta , Masculino , Estimulación Luminosa , Corteza Visual/citología , Corteza Visual/fisiología
9.
J Struct Biol ; 212(3): 107645, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-33045383

RESUMEN

Pyridoxal 5'-phosphate (PLP) is the active form of vitamin B6 and a cofactor for more than 140 enzymes. This coenzyme plays a pivotal role in catalysis of various enzymatic reactions that are critical for the survival of organisms. Entamoeba histolytica depends on the uptake of pyridoxal (PL), a B6 vitamer from the external environment which is then phosphorylated by pyridoxal kinase (EhPLK) to form PLP via the salvage pathway. E. histolytica cannot synthesise vitamin B6de-novo, and also lacks pyridoxine 5'-phosphate oxidase, a salvage pathway enzyme required to produce PLP from pyridoxine phosphate (PNP) and pyridoxamine phosphate (PMP). Analysing the importance of PLK in E. histolytica, we have determined the high-resolution crystal structures of the dimeric pyridoxal kinase in apo, ADP-bound, and PLP-bound states. These structures provided a snapshot of the transition state and help in understanding the reaction mechanism in greater detail. The EhPLK structure significantly differed from the human homologue at its PLP binding site, and the phylogenetic study also revealed its divergence from human PLK. Further, gene regulation of EhPLK using sense and antisense RNA showed that any change in optimal level is harmful to the pathogen. Biochemical and in vivo studies unveiled EhPLK to be essential for this pathogen, while the molecular differences with human PLK structure can be exploited for the structure-guided design of EhPLK inhibitors.


Asunto(s)
Entamoeba histolytica/metabolismo , Piridoxal Quinasa/metabolismo , Sitios de Unión/fisiología , Catálisis , Fosforilación/fisiología , Filogenia , Fosfato de Piridoxal/análogos & derivados , Fosfato de Piridoxal/metabolismo , Piridoxamina/análogos & derivados , Piridoxamina/metabolismo , Piridoxaminafosfato Oxidasa/metabolismo , Vitamina B 6/metabolismo
10.
Mol Microbiol ; 112(2): 718-739, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31132312

RESUMEN

O-acetylserine sulfhydrylase (OASS) and cystathionine ß-synthase (CBS) are members of the PLP-II family, and involved in L-cysteine production. OASS produces L-cysteine via a de novo pathway while CBS participates in the reverse transsulfuration pathway. O-acetylserine-dependent CBS (OCBS) was previously identified as a new member of the PLP-II family, which are predominantly seen in bacteria. The bacterium Helicobacter pylori possess only one OASS (hp0107) gene and we showed that the protein coded by this gene actually functions as an OCBS and utilizes L-homocysteine and O-acetylserine (OAS) to produce cystathionine. HpOCBS did not show CBS activity with the substrate L-serine and required OAS exclusively. The HpOCBS structure in complex with methionine showed a closed cleft state, explaining the initial mode of substrate binding. Sequence and structural analyses showed differences between the active sites of OCBS and CBS, and explain their different substrate preferences. We identified three hydrophobic residues near the active site of OCBS, corresponding to one serine and two tyrosine residues in CBSs. Mutational studies were performed on HpOCBS and Saccharomyces cerevisiae CBS. A ScCBS double mutant (Y158F/Y226V) did not display activity with L-serine, indicating indispensability of these polar residues for selecting substrate L-serine, however, did show activity with OAS.


Asunto(s)
Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Cistationina betasintasa/química , Cistationina betasintasa/metabolismo , Helicobacter pylori/enzimología , Proteínas Bacterianas/genética , Sitios de Unión , Dominio Catalítico , Cistationina/metabolismo , Cistationina betasintasa/genética , Estabilidad de Enzimas , Helicobacter pylori/química , Helicobacter pylori/genética , Homocisteína/metabolismo , Concentración de Iones de Hidrógeno , Cinética , Metionina/metabolismo , Serina/análogos & derivados , Serina/metabolismo , Especificidad por Sustrato
11.
Nat Methods ; 14(3): 271-274, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-28114289

RESUMEN

Optogenetics uses light exposure to manipulate physiology in genetically modified organisms. Abundant tools for optogenetic excitation are available, but the limitations of current optogenetic inhibitors present an obstacle to demonstrating the necessity of neuronal circuits. Here we show that anion channelrhodopsins can be used to specifically and rapidly inhibit neural systems involved in Drosophila locomotion, wing expansion, memory retrieval and gustation, thus demonstrating their broad utility in the circuit analysis of behavior.


Asunto(s)
Conducta Animal/efectos de los fármacos , Drosophila/fisiología , Vías Nerviosas/fisiología , Optogenética/métodos , Rodopsina/farmacología , Potenciales de Acción/fisiología , Animales , Conducta Animal/fisiología , Luz , Locomoción/fisiología , Neuronas/fisiología , Organismos Modificados Genéticamente , Percepción del Gusto/fisiología , Canales Aniónicos Dependientes del Voltaje/fisiología
12.
J Sports Sci ; 38(14): 1629-1634, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32308132

RESUMEN

While foot orthoses are commonly used in running, little is known regarding biomechanical risk potentials during uphill running. This study investigated the effects of arch-support orthoses on kinetic and kinematic variables when running at different inclinations. Sixteen male participants ran at different inclinations (0°, 3° and 6°) when wearing arch-support and flat orthoses on an instrumented treadmill. Arch-support orthoses induced longer contact time, larger initial ankle dorsiflexion, maximum ankle eversion, and knee sagittal range of motion (RoM) (p < 0.05). As incline slopes increased, vertical impact peak and loading rate, stride length, and ankle coronal RoM decreased, but contact time, stride frequency, initial ankle dorsiflexion and inversion, maximum dorsiflexion, initial knee flexion, and ankle sagittal RoM increased (p < 0.05). Furthermore, knee sagittal RoM was lowest when running at an inclination of 3°. The interaction effect indicated that in arch-support condition, participants running at 6° induced higher maximum ankle eversion than running at 0° (p < 0.05), while no differences were found in flat orthosis condition. These findings suggest that the use of arch-support orthoses would influence running biomechanics that is related to injury risks. Running at higher inclination led to more alterations to biomechanical variables than at lower inclination.


Asunto(s)
Ortesis del Pié , Extremidad Inferior/fisiología , Carrera/fisiología , Adulto , Tobillo/fisiología , Fenómenos Biomecánicos , Diseño de Equipo , Prueba de Esfuerzo/métodos , Humanos , Cinética , Rodilla/fisiología , Masculino , Rango del Movimiento Articular , Adulto Joven
13.
Community Ment Health J ; 56(3): 393-403, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31522350

RESUMEN

The present study aimed to explore the relationship between cyber-bullying and psychological security, psychological loneliness, and age. In other words, it sought to identify the predictive power of these three variables on cyber-bullying among university students. Participants were 426 male and female Saudi university students aged between 18 and 36 years (M = 21.00, SD = 2.42). Three scales were used to probe cyber-bullying and psychological security and loneliness. Data analysis revealed that 17.6% of the participants were cyber-bullies. Significant differences in cyber-bullying were found by gender (in favor of males). A significant positive correlation was found between cyber-bullying on one hand and psychological security and loneliness and age on the other. The findings also revealed that cyber-bullying among university students can be predicted by psychological loneliness and age. Psychological loneliness is the best predictor of cyber-bullying. It explained .284 of cyber-bullying, while age, psychological loneliness explained .339 of cyber-bullying. These findings shed more light on the psychological aspects included in cyber-bullying. It is a significant contribution in that it identified the motives beyond cyber-bullying and its adverse effects on individuals.


Asunto(s)
Acoso Escolar , Víctimas de Crimen , Ciberacoso , Adolescente , Adulto , Femenino , Humanos , Internet , Soledad , Masculino , Estudiantes , Universidades , Adulto Joven
14.
Community Ment Health J ; 55(5): 825-830, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30661142

RESUMEN

There are an increasing number of studies on smartphone addiction (SA) among students, and also a number of cross-cultural ones. We add to this body of research by presenting, for the first time, a cross-cultural study comparing students in four Middle Eastern countries: Sudan, Jordan, Saudi Arabia, and Yemen. In this context, we also attempt to replicate findings-in other studies-that there are differences in smartphone addiction prevalence along the lines of sex, culture and subject of study. These findings were indeed replicated in a Middle Eastern context. We found significant differences between the Jordanian sample and the other three samples, with Jordanians displaying higher SA. The Sudanese displayed higher SA than the Yemenis, and the Saudis higher than the Sudanese or the Yemeni. We also found that females displayed greater SA than males and humanities students greater SA than science students.


Asunto(s)
Conducta Adictiva , Teléfono Inteligente , Estudiantes/psicología , Adolescente , Adulto , Comparación Transcultural , Cultura , Femenino , Humanos , Masculino , Medio Oriente , Factores Sexuales , Adulto Joven
15.
J Theor Biol ; 445: 92-102, 2018 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-29476830

RESUMEN

Phosphorylation of eukaryotic translation initiation factor 2 (eIF2) is one of the best studied and most widely used means for regulating protein synthesis activity in eukaryotic cells. This pathway regulates protein synthesis in response to stresses, viral infections, and nutrient depletion, among others. We present analyses of an ordinary differential equation-based model of this pathway, which aim to identify its principal robustness-conferring features. Our analyses indicate that robustness is a distributed property, rather than arising from the properties of any one individual pathway species. However, robustness-conferring properties are unevenly distributed between the different species, and we identify a guanine nucleotide dissociation inhibitor (GDI) complex as a species that likely contributes strongly to the robustness of the pathway. Our analyses make further predictions on the dynamic response to different types of kinases that impinge on eIF2.


Asunto(s)
Células Eucariotas/metabolismo , Factor 2 Eucariótico de Iniciación/metabolismo , Modelos Biológicos , Biosíntesis de Proteínas/fisiología , Animales , Células Eucariotas/citología , Humanos , Fosforilación/fisiología
16.
J Oncol Pharm Pract ; 24(4): 309-313, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28345492

RESUMEN

Rasburicase is indicated for the prevention and treatment of tumor lysis syndrome which can be a potentially life-threatening emergency. The drug has oxidizing potential and as an adverse effect, it can convert the ferrous form of iron in erythrocytes to its ferric form resulting in the formation of methemoglobin which makes the heme component incapable of carrying oxygen. Patients with glucose-6-phosphate dehydrogenase enzyme deficiency are at high risk of methemoglobinemia from oxidizing agents. Symptoms of methemoglobinemia range from none to life-threatening hypoxemia, cyanosis and respiratory compromise. Treatment is indicated at levels above 20% and at lower levels if the patient is significantly anemic. We present a case of a 60-year-old male with diffuse large B cell lymphoma at high risk of tumor lysis syndrome. Rasburicase was administered to prevent renal failure and further rise in uric acid. Twenty-four hours later, a bedside pulse oximetry showed an oxygen saturation ranging from 60 to 65% with minimal cyanosis. Co-oximetry revealed a methemoglobin level of 9.8%. Methylene blue was administered and the methemoglobin level decreased to 2.6%. However, the patient developed hemolysis several hours later, likely secondary to rasburicase and methylene blue, requiring transfusion support. We discuss this potentially fatal and initially asymptomatic adverse effect of rasburicase along with diagnostic and treatment considerations, and review the cases described in the current literature.


Asunto(s)
Supresores de la Gota/efectos adversos , Metahemoglobinemia/inducido químicamente , Metahemoglobinemia/diagnóstico , Urato Oxidasa/efectos adversos , Humanos , Linfoma de Células B Grandes Difuso/sangre , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Masculino , Metahemoglobinemia/sangre , Persona de Mediana Edad , Proteínas Recombinantes/efectos adversos , Síndrome de Lisis Tumoral/tratamiento farmacológico
17.
PLoS Genet ; 11(12): e1005718, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26647168

RESUMEN

Genetic studies in Drosophila reveal that olfactory memory relies on a brain structure called the mushroom body. The mainstream view is that each of the three lobes of the mushroom body play specialized roles in short-term aversive olfactory memory, but a number of studies have made divergent conclusions based on their varying experimental findings. Like many fields, neurogenetics uses null hypothesis significance testing for data analysis. Critics of significance testing claim that this method promotes discrepancies by using arbitrary thresholds (α) to apply reject/accept dichotomies to continuous data, which is not reflective of the biological reality of quantitative phenotypes. We explored using estimation statistics, an alternative data analysis framework, to examine published fly short-term memory data. Systematic review was used to identify behavioral experiments examining the physiological basis of olfactory memory and meta-analytic approaches were applied to assess the role of lobular specialization. Multivariate meta-regression models revealed that short-term memory lobular specialization is not supported by the data; it identified the cellular extent of a transgenic driver as the major predictor of its effect on short-term memory. These findings demonstrate that effect sizes, meta-analysis, meta-regression, hierarchical models and estimation methods in general can be successfully harnessed to identify knowledge gaps, synthesize divergent results, accommodate heterogeneous experimental design and quantify genetic mechanisms.


Asunto(s)
Conducta Animal/fisiología , Memoria a Corto Plazo/fisiología , Cuerpos Pedunculados/fisiología , Neuronas/fisiología , Animales , Drosophila melanogaster/fisiología , Aprendizaje/fisiología , Vías Olfatorias/metabolismo , Vías Olfatorias/fisiología , Olfato/genética , Olfato/fisiología , Transmisión Sináptica/fisiología
18.
BMC Biol ; 15(1): 103, 2017 11 03.
Artículo en Inglés | MEDLINE | ID: mdl-29100505

RESUMEN

BACKGROUND: Optical silencing of activity provides a way to test the necessity of neurons in behaviour. Two light-gated anion channels, GtACR1 and GtACR2, have recently been shown to potently inhibit activity in cultured mammalian neurons and in Drosophila. Here, we test the usefulness of these channels in larval zebrafish, using spontaneous coiling behaviour as the assay. RESULTS: When the GtACRs were expressed in spinal neurons of embryonic zebrafish and actuated with blue or green light, spontaneous movement was inhibited. In GtACR1-expressing fish, only 3 µW/mm2 of light was sufficient to have an effect; GtACR2, which is poorly trafficked, required slightly stronger illumination. No inhibition was seen in non-expressing siblings. After light offset, the movement of GtACR-expressing fish increased, which suggested that termination of light-induced neural inhibition may lead to activation. Consistent with this, two-photon imaging of spinal neurons showed that blue light inhibited spontaneous activity in spinal neurons of GtACR1-expressing fish, and that the level of intracellular calcium increased following light offset. CONCLUSIONS: These results show that GtACR1 and GtACR2 can be used to optically inhibit neurons in larval zebrafish with high efficiency. The activity elicited at light offset needs to be taken into consideration in experimental design, although this property can provide insight into the effects of transiently stimulating a circuit.


Asunto(s)
Proteínas Algáceas/genética , Channelrhodopsins/genética , Criptófitas/genética , Neuronas/fisiología , Pez Cebra/fisiología , Proteínas Algáceas/metabolismo , Animales , Channelrhodopsins/metabolismo , Criptófitas/metabolismo , Movimiento/fisiología
19.
Arch Biochem Biophys ; 604: 128-42, 2016 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-27372899

RESUMEN

Pro-coagulant, anti-coagulant and fibrinolytic pathways are responsible for maintaining hemostatic balance under physiological conditions. Any deviation from these pathways would result in hypercoagulability leading to life threatening diseases like myocardial infarction, stroke, portal vein thrombosis, deep vein thrombosis (DVT) and pulmonary embolism (PE). Angiogenesis is the process of sprouting of new blood vessels from pre-existing ones and plays a critical role in vascular repair, diabetic retinopathy, chronic inflammation and cancer progression. Serpins; a superfamily of protease inhibitors, play a key role in regulating both angiogenesis and coagulation. They are characterized by the presence of highly conserved secondary structure comprising of 3 ß-sheets and 7-9 α-helices. Inhibitory role of serpins is modulated by binding to cofactors, specially heparin and heparan sulfate proteoglycans (HSPGs) present on cell surfaces and extracellular matrix. Heparin and HSPGs are the mainstay of anti-coagulant therapy and also have therapeutic potential as anti-angiogenic inhibitors. Many of the heparin binding serpins that regulate coagulation cascade are also potent inhibitors of angiogenesis. Understanding the molecular mechanism of the switch between their specific anti-coagulant and anti-angiogenic role during inflammation, stress and regular hemostasis is important. In this review, we have tried to integrate the role of different serpins, their interaction with cofactors and their interplay in regulating coagulation and angiogenesis.


Asunto(s)
Coagulación Sanguínea , Heparina/química , Neovascularización Patológica , Serpinas/fisiología , Angiotensinógeno/química , Animales , Anticoagulantes/química , Antitrombinas/química , Proteínas Sanguíneas/química , Vasos Sanguíneos/fisiopatología , Progresión de la Enfermedad , Matriz Extracelular/química , Proteínas del Ojo/química , Fibrinólisis , Proteoglicanos de Heparán Sulfato/química , Heparina de Bajo-Peso-Molecular/química , Homeostasis , Humanos , Inflamación , Conformación Molecular , Factores de Crecimiento Nervioso/química , Inhibidor 1 de Activador Plasminogénico/química , Inhibidor de Proteína C/química , Serpina E2/química , Serpinas/química , Transducción de Señal
20.
J Adv Res ; 50: 83-105, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-36332796

RESUMEN

BACKGROUND: Parkinson's disease (PD) is a disease of ⍺-synuclein aggregation-mediated dopaminergic neuronal loss in the substantia nigra pars compacta, which leads to motor and non-motor symptoms. Through the last two decades of research, there has been growing consensus that inflammation-mediated oxidative stress, mitochondrial dysfunction, and cytokine-induced toxicity are mainly involved in neuronal damage and loss associated with PD. However, it remains unclear how these mechanisms relate to sporadic PD, a more common form of PD. Both enteric and central nervous systems have been implicated in the pathogenesis of sporadic PD, thus highlighting the crosstalk between the gut and brain. AIM: of Review: In this review, we summarize how alterations in the gut microbiome can affect PD pathogenesis. We highlight various mechanisms increasing/decreasing the risk of PD development. Based on the previous supporting evidence, we suggest how early interventions could protect against PD development and how controlling specific factors, including our diet, could modify our perspective on disease mechanisms and therapeutics. We explain the strong relationship between the gut microbiota and the brain in PD subjects, by delineating the multiple mechanisms involved inneuroinflammation and oxidative stress. We conclude that the neurodetrimental effects of western diet (WD) and the neuroprotective effects of Mediterranean diets should be further exploredin humans through clinical trials. Key Scientific Concepts of Review: Alterations in the gut microbiome and associated metabolites may contribute to pathogenesis in PD. In some studies, probiotics have been shown to exert anti-oxidative effects in PD via improved mitochondrial dynamics and homeostasis, thus reducing PD-related consequences. However, there is a significant unmet need for randomized clinical trials to investigate the effectiveness of microbial products, probiotic-based supplementation, and dietary intervention in reversing gut microbial dysbiosis in PD.


Asunto(s)
Microbioma Gastrointestinal , Enfermedad de Parkinson , Probióticos , Humanos , Enfermedad de Parkinson/terapia , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/patología , Microbioma Gastrointestinal/fisiología , Inflamación/metabolismo , Probióticos/uso terapéutico , Dieta
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