Developmental analysis of Spalt function in the Drosophila prothoracic gland.

The Spalt transcriptional regulators participate in a variety of cell fate specification processes during development, regulating transcription through interactions with DNA AT-rich regions. Spalt proteins also bind to heterochromatic regions, and some of their effects require interactions with the NuRD chromatin remodeling and deacetylase complex. Most of the biological roles of Spalt proteins have been characterized in diploid cells engaged in cell proliferation. Here, we address the function of Drosophila Spalt genes in the development of a larval tissue formed by polyploid cells, the prothoracic gland, the cells of which undergo several rounds of DNA replication without mitosis during larval development. We show that prothoracic glands depleted of Spalt expression display severe changes in the size of the nucleolus, the morphology of the nuclear envelope and the disposition of the chromatin within the nucleus, leading to a failure in the synthesis of ecdysone. We propose that loss of ecdysone production in the prothoracic gland of Spalt mutants is primarily caused by defects in nuclear pore complex function that occur as a consequence of faulty interactions between heterochromatic regions and the nuclear envelope.

Parametric subtracted post-ictal diffusion tensor imaging for guiding direct neurostimulation therapy.

Parametric subtracted post-ictal diffusion tensor imaging (pspiDTI) is a novel imaging technique developed at our center to visualize transient, patient-specific, ictal-associated water diffusion abnormalities in hippocampal-associated axonal tissue. PspiDTI can elucidate putative connectivity patterns, tracing ictal propagation following a partial-onset seizure without generalization secondarily. PspiDTI compares two DTI volumes acquired during the early post-ictal period (<4 hr), and baseline inter-ictal interval (>24 hr post-seizure). This technique performs a voxel-wise parametric test to identify statistically significant transient ictal-associated changes in water diffusivity involving white matter (WM). Our technique was applied to six patients with refractory partial-onset epilepsy who were candidates for direct cortical responsive neurostimulation (RNS) therapy. Global and region-specific fractional anisotropy decreases, relative to baseline, were detected in all patients with a 17.01% (p < .01) relative mean decrement, while trace increases were found in 6/6 (100%) patients with a 13.30% (p < .01) relative global mean increment. Changes in diffusivity were anatomically compared with transient hyper-perfusion as detected by subtracted ictal SPECT co-registered to MRI (SISCOM). In 5/6 (83.33%) patients, alterations in WM diffusivity were detected adjacent to the SISCOM signal localized predominantly in gray matter. In 4/6 patients, post-implant RNS electrocorticography revealed early ictal propagation between implanted RNS depth leads guided by pspiDTI, hence validating concordant abnormal diffusivity regions detected by our technique. PspiDTI can complement the conventional pre-surgical evaluation to provide additional crucial information regarding WM ictal-propagation pathways between predominantly gray matter ictal-onset zones. When incorporated into a multi-modality pre-surgical workflow, pspiDTI can aid in defining critical nodes between ictogenic regions. This information can be used to strategically implant a limited set of two RNS depth leads for maximizing the extent to which direct cortical RNS can modulate a potentially extensive epileptogenic network.

C6orf89 encodes three distinct HDAC enhancers that function in the nucleolus, the golgi and the midbody.

We report here that C6orf89, which encodes a protein that interacts with bombesin receptor subtype-3 and accelerates cell cycle progression and wound repair in human bronchial epithelial cells (Liu et al., 2011, PLoS ONE 6: e23072), encodes one soluble and two type II membrane proteins that function as histone deacetylases (HDAC) enhancers. Soluble 34/64sp is selectively targeted to the nucleolus and is retained in nucleolar organiser regions (NORs) in mitotic cells. Nucleolar 34/64sp is integrated into the ribosomal gene transcription machinery, colocalises and coimmunoprecipitates with the Pol I transcription factor UBF, and undergoes a dramatic relocalisation to the nucleolus upon the arrest of rDNA transcription, protein synthesis and PI3K/mTORC2 signalling. Membrane 42/116mp localises to the Golgi and the midbody, and its controlled ectopic expression provokes the disruption of the Golgi cisternae and hinders the separation of daughter cells and the completion of mitosis. The latter effect is also produced by the microinjection of an affinity-purified amfion antibody. The identification of C60rf89 as a gene that encodes three distinct proteins with the capacity to enhance the activity of histone deacetylases (HDACs) in the nucleolus, the Golgi and the midbody provides new information regarding the components of the acetylome and their capacity to interact with different functional groups in the cell.

Responsive Neurostimulation of the Mesial Temporal White Matter in Bilateral Temporal Lobe Epilepsy.

BACKGROUND: Responsive neuromodulation (RNS) is a treatment option for patients with medically refractory bilateral mesial temporal lobe epilepsy (MTLE). A paucity of data exists on the feasibility and clinical outcome of hippocampal-sparing bilateral RNS depth lead placements within the parahippocampal white matter or temporal stem. OBJECTIVE: To evaluate seizure reduction outcomes with at least a 1-yr follow-up in individuals with bilateral MTLE undergoing hippocampus-sparing implantation of RNS depth leads. METHODS: A retrospective analysis of prospectively collected data was performed on patients at our institution with bilateral MTLE who were implanted with RNS depth leads along the longitudinal extent of bitemporal parahippocampal white matter or temporal stem. Baseline and postoperative seizure frequency, previous surgical interventions, and postimplantation electrocorticography and stimulation data were analyzed. RESULTS: Ten patients were included in the study (7 male, 3 female). Overall seizure frequency declined by a median 44.25% at 3.13 yr (standard deviation 3.31) postimplantation. Four patients (40%) achieved 50% responder rate at latest follow-up. Two of four patients with focal onset bilateral tonic-clonic seizures became completely seizure-free. Forty percent of patients were previously implanted with a vagus nerve stimulator, and 20% underwent a prior temporal lobectomy. All depth lead placements were confirmed as radiographically located in the parahippocampal white matter or temporal stem without hippocampus violation. There were no cases of lead malposition. CONCLUSION: Extrahippocampal or temporal stem white matter targeting during RNS surgery for bitemporal MTLE is feasible and allows for electrographic seizure detection. Larger controlled studies with longer follow-up are needed to validate these preliminary findings.

Seroprevalence of Brucella canis in canines from a dog shelter in Bogotá, Colombia / [Seroprevalencia de Brucella canis en perros de un refugio para animales de compañía en Bogotá, Colombia].

Introduction: The risk of Brucella canis infection in humans and dogs has increased due to the permanent exposure to asymptomatic carrier dogs. In Colombia, there is evidence of B. canis infection in humans living with dogs. In the case of Bogotá, an additional concern is the lack of updated information related to the prevalence of the infection in dogs. Objective: To determine the seroprevalence of infection by B. canis in dogs intended for adoption programs in Bogotá. Materials and methods: By means of a descriptive cross-sectional study carried out in a dog shelter in Bogotá, anti-B. canis IgG antibodies were detected in the serum from 51 dogs 28 females and 23 males) using a lateral-flow immunochromatographic test. Additionally, seropositive animals were analyzed with PCR to detect Brucella spp DNA. Results: Brucella canis seroprevalence was 1.96% (1/51). The seropositive dog was an asymptomatic three-year-old she-dog in which no bacteria DNA was detected in the blood through PCR. Conclusions: The seroprevalence determined in this study represented by a single dog with anti-B. canis IgG can be considered a potential risk both for canine and human populations since this single dog could have a persistent infection capable of spreading the bacteria.

Introducción. El riesgo de infección con Brucella canis en humanos y perros aumenta con la exposición constante a perros portadores asintomáticos. En Colombia hay evidencia de infección con B. canis en personas que conviven con perros. Una preocupación adicional en Bogotá es la falta de información actualizada sobre la prevalencia de la infección en perros destinados a programas de adopción. Objetivo. Establecer la seroprevalencia de la infección por B. canis en perros de un refugio para animales de compañía destinados a la adopción en Bogotá. Materiales y métodos. Se hizo un estudio descriptivo de corte transversal en un refugio ara animales de Bogotá. Se detectaron anticuerpos contra B. canis en el suero de 51 perros (28 hembras y 23 machos) mediante una prueba inmunocromatográfica de flujo lateral. Asimismo, los individuos positivos se analizaron con PCR para la detección del ADN de Brucella spp. Resultado. La seroprevalencia de B. canis fue del 1,96 % (1/51). El perro seropositivo correspondió a una hembra asintomática de tres años de edad en la cual no se detectó ADN bacteriano en sangre mediante la PCR. Conclusiones. La seroprevalencia representada por un solo perro con IgG anti-B. canis puede considerarse un riesgo potencial para las poblaciones de perros y humanos, ya que podría tratarse de un animal con infección persistente capaz de diseminar la bacteria.

Seroprevalencia de Brucella canis en perros de un refugio para animales de compañía en Bogotá, Colombia / Seroprevalence of Brucella canis in canines from a dog shelter in Bogotá, Colombia

Resumen | Introducción. El riesgo de infección con Brucella canis en humanos y perros aumenta con la exposición constante a perros portadores asintomáticos. En Colombia hay evidencia de infección con B. canis en personas que conviven con perros. Una preocupación adicional en Bogotá es la falta de información actualizada sobre la prevalencia de la infección en perros destinados a programas de adopción. Objetivo. Establecer la seroprevalencia de la infección por B. canis en perros de un refugio para animales de compañía destinados a la adopción en Bogotá. Materiales y métodos. Se hizo un estudio descriptivo de corte transversal en un refugio para animales de Bogotá. Se detectaron anticuerpos contra B. canis en el suero de 51 perros (28 hembras y 23 machos) mediante una prueba inmunocromatográfica de flujo lateral. Asimismo, los individuos positivos se analizaron con PCR para la detección del ADN de Brucella spp. Resultados. La seroprevalencia de B. canis fue del 1,96 % (1/51). El perro seropositivo correspondió a una hembra asintomática de tres años de edad en la cual no se detectó ADN bacteriano en sangre mediante la PCR. Conclusiones. La seroprevalencia representada por un solo perro con IgG anti-B. canis puede considerarse un riesgo potencial para las poblaciones de perros y humanos, ya que podría tratarse de un animal con infección persistente capaz de diseminar la bacteria.

Abstract | Introduction: The risk of Brucella canis infection in humans and dogs has increased due to the permanent exposure to asymptomatic carrier dogs. In Colombia, there is evidence of B. canis infection in humans living with dogs. In the case of Bogotá, an additional concern is the lack of updated information related to the prevalence of the infection in dogs. Objective: To determine the seroprevalence of infection by B. canis in dogs intended for adoption programs in Bogotá. Materials and methods: By means of a descriptive cross-sectional study carried out in a dog shelter in Bogotá, anti-B. canis IgG antibodies were detected in the serum from 51 dogs (28 females and 23 males) using a lateral-flow immunochromatographic test. Additionally, seropositive animals were analyzed with PCR to detect Brucella spp DNA. Results: Brucella canis seroprevalence was 1.96% (1/51). The seropositive dog was an asymptomatic three-year-old she-dog in which no bacteria DNA was detected in the blood through PCR. Conclusions: The seroprevalence determined in this study represented by a single dog with anti-B. canis IgG can be considered a potential risk both for canine and human populations since this single dog could have a persistent infection capable of spreading the bacteria.

Cdk5, the multifunctional surveyor.

Cyclin-dependent kinases (Cdks) are a family of proline-directed Ser/Thr kinases known for their role in the control of cell cycle progression. In 1992, this family was joined by Cdk5, which is an atypical member in that it uses its own activators and is multifunctional, playing important regulatory roles in multiple cellular functions. Here, we review the structure of Cdk5 and its various mechanisms of activation within the context of the Cdk family. We also address the functional significance of the numerous and varied targets of Cdk5 within pathways that control the organization of the cytoskeleton and focal adhesions, signaling cascades, membrane dynamics and function, cell metabolism, cycle arrest in postmitotic cells, gene transcription and cell survival, all within the context of the adaptation of cells and life systems to changing internal and external environments.

Molecular mechanisms of copper homeostasis.

The transition metal copper (Cu) is an essential trace element for all biota. Its redox properties bestow Cu with capabilities that are simultaneously essential and potentially damaging to the cell. Free Cu is virtually absent in the cell. The descriptions of the structural and functional organization of the metallothioneins, Cu-chaperones and P-type ATPases as well as of the mechanisms that regulate their distribution and functioning in the cell have enormously advanced our understanding of the Cu homeostasis and metabolism in the last decade. Cu is stored by metallothioneins and distributed by specialized chaperones to specific cell targets that make use of its redox properties. Transfer of Cu to newly synthesized cuproenzymes and Cu disposal is performed by the individual or concerted actions of the P-type ATPases ATP7A and ATP7B expressed in tissues. In mammalians liver is the major captor, distributor and excreter of Cu. Mutations in the P-type ATPases that interfere with their functioning and traffic are cause of the life-threatening Wilson (ATP7B) and Menkes (ATP7A) diseases.

The insulin-sensitive glucose transporter, GLUT4, interacts physically with Daxx. Two proteins with capacity to bind Ubc9 and conjugated to SUMO1.

In this study we have used the yeast two-hybrid system to identify proteins that interact with the carboxyl-cytoplasmic domain (residues 464-509) of the insulin-sensitive glucose transporter GLUT4 (C-GLUT4). Using as bait C-GLUT4, we have isolated the carboxyl domain of Daxx (C-Daxx), the adaptor protein associated with the Fas and the type II TGF-beta (TbetaRII) receptors (1,2 ). The two-hybrid interaction between C-GLUT4 and C-Daxx is validated by the ability of in vitro translated C-GLUT4 to interact with in vitro translated full-length Daxx and C-Daxx. C-Daxx does not interact with the C-cytoplasmic domain of GLUT1, the ubiquitous glucose transporter homologous to GLUT4. Replacement of alanine and serine for the dileucine pair (Leu(489)-Leu(490)) critical for targeting GLUT4 from the trans-Golgi network to the perinuclear intracellular store as well as for its surface internalization by endocytosis inhibits 2-fold the interaction of C-GLUT4 with Daxx. Daxx is pulled down with GLUT4 immunoprecipitated from lysates of 3T3-L1 fibroblasts stably transfected with GLUT4 and 3T3-L1 adipocytes expressing physiological levels of the two proteins. Similarly, GLUT4 is recovered with anti-Daxx immunoprecipitates. Using an established cell fractionation procedure we present evidence for the existence of two distinct intracellular Daxx pools in the nucleus and low density microsomes. Confocal immunofluorescence microscopy studies localize Daxx to promyelocytic leukemia nuclear bodies and punctate cytoplasmic structures, often organized in strings and underneath the plasma membrane. Daxx and GLUT4 are SUMOlated as shown by their reaction with an anti-SUMO1 antibody and by the ability of this antibody to pull down Daxx and GLUT4.