DDR1 and Its Ligand, Collagen IV, Are Involved in In Vitro Oligodendrocyte Maturation.

Discoidin domain receptor 1 (DDR1) is a tyrosine kinase receptor expressed in epithelial cells from different tissues in which collagen binding activates pleiotropic functions. In the brain, DDR1 is mainly expressed in oligodendrocytes (OLs), the function of which is unclear. Whether collagen can activate DDR1 in OLs has not been studied. Here, we assessed the expression of DDR1 during in vitro OL differentiation, including collagen IV incubation, and the capability of collagen IV to induce DDR1 phosphorylation. Experiments were performed using two in vitro models of OL differentiation: OLs derived from adult rat neural stem cells (NSCs) and the HOG16 human oligodendroglial cell line. Immunocytofluorescence, western blotting, and ELISA were performed to analyze these questions. The differentiation of OLs from NSCs was addressed using oligodendrocyte transcription factor 2 (Olig2) and myelin basic protein (MBP). In HOG16 OLs, collagen IV induced DDR1 phosphorylation through slow and sustained kinetics. In NSC-derived OLs, DDR1 was found in a high proportion of differentiating cells (MBP+/Olig2+), but its protein expression was decreased in later stages. The addition of collagen IV did not change the number of DDR1+/MBP+ cells but did accelerate OL branching. Here, we provide the first demonstration that collagen IV mediates the phosphorylation of DDR1 in HOG16 cells and that the in vitro co-expression of DDR1 and MBP is associated with accelerated branching during the differentiation of primary OLs.

Pericytes in Multiple Sclerosis.

Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease that affects the central nervous system (CNS), particularly, in young adults. Current MS treatments aim to reduce demyelination; however, these have limited efficacy, display side effects and lack of regenerative activities. Oligodendrocyte progenitor cells (OPCs) represents the major source for new myelin. Upon demyelination, OPCs get activated, proliferate, migrate towards the lesion, and differentiate into remyelinating oligodendrocytes. Although myelin repair (remyelination) represents a robust response to myelin damage, during MS, this regenerative phenomenon decays in efficiency or even fails. CNS-resident pericytes (CNS-PCs) are essential for vascular homeostasis regulating blood-brain barrier (BBB) permeability and stability as well as endothelial cells (ECs) function during angiogenesis and neovascularization. Recent studies indicate that CNS-PCs also play a crucial role regulating OPC function during remyelination, and very importantly, these cells are substantially affected in MS. This chapter summarizes important aspects of MS and CNS remyelination as well as it provides new insights supporting the contribution of CNS-PCs to myelin regeneration and to MS pathology. Currently, there is evidence arguing in favor of CNS-PCs as novel therapeutic targets for the development of future treatments for MS.

Pericytes Favor Oligodendrocyte Fate Choice in Adult Neural Stem Cells.

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Upon demyelination, oligodendrocyte progenitor cells (OPCs) are activated and they proliferate, migrate and differentiate into myelin-producing oligodendrocytes. Besides OPCs, neural stem cells (NSCs) may respond to demyelination and generate oligodendrocytes. We have recently shown that CNS-resident pericytes (PCs) respond to demyelination, proliferate and secrete Laminin alpha2 (Lama2) that, in turn, enhances OPC differentiation. Here, we aimed to evaluate whether PCs influence the fate choice of NSCs in vitro, towards the production of new myelin-producing cells. Indeed, upon exposure to conditioned medium derived from PCs (PC-CM), the majority of NSCs gave rise to GalC- and myelin basic protein (MBP)-expressing oligodendrocytes at the expense of the generation of GFAP-positive astrocytes. Consistent with these findings, PC-CM induces an increase in the expression of the oligodendrocyte fate determinant Olig2, while the expression level of the astrocyte determinant ID2 is decreased. Finally, pre-incubation of PC-CM with an anti-Lama2 antibody prevented the generation of oligodendrocytes. Our findings indicate that PCs-derived Lama2 instructs NSCs to an oligodendrocyte fate choice favoring the generation of myelin-producing cells at the expense of astrocytes in vitro. Further studies aiming to reveal the role of PCs during remyelination may pave the way for the development of new therapies for the treatment of MS.

Retinal Pericytes: Characterization of Vascular Development-Dependent Induction Time Points in an Inducible NG2 Reporter Mouse Model.

Purpose/aim of the study: In the retina, defects in pericytes (PCs) function/loss are associated with various complications; however, the exact pathological mechanisms are still not fully elucidated. Following the behavior of retina-resident PCs during health and disease will reveal new insights for both the understanding of pathological mechanisms and the development of new regenerative therapies for the treatment of retinopathies. The main goal of this study is to determine whether the NG2-reporter mouse (NG2CreERTM-eGFP) is a suitable model to study the fate of retina-resident PCs. MATERIAL AND METHODS: Vascular development-dependent reporter induction in retinal PCs was evaluated at different time points [(a) > P21, (b) < P21, and (c) P1 to > P21)] and additionally four different modes of application were tested. Reporter expression was evaluated by enhanced green fluorescent protein (eGFP) immunofluorescence by confocal microscopy and induction efficiency was calculated by analyzing NG2-expressing PCs in comparison to eGFP-labeled PCs in the three capillary layers. RESULTS: eGFP-positive PCs were detected in the three retinal capillary layers at all time points and administration routes tested. Multiple tamoxifen (TAM) applications in adult (> P21) NG2CreERTM-eGFP mice resulted in 3.59% eGFP-positive PCs. 2.37% eGFP-labeled PCs were detected after single intraperitoneal TAM injections at early postnatal days (P2/P5); however, just 1.61% PCs revealed reporter expression upon activation via the lactating mother (P4-P7). The highest number of eGFP-labeled PCs (7.09%) was detected following triple TAM administrations (P10-P12). The number of reporter-positive PCs doubled using homozygous animals. CONCLUSION: Despite low recombination efficiency in the used PC-specific fate mapping mouse model, changes in NG2 promoter activity of PCs during vascular development are indicated by single and multiple TAM inductions at different developmental time points. Nevertheless, these findings need further confirmation in up-coming studies by using homozygous NG2CreERTM-eGFP mice and additionally by mating the NG2CreERTM with a different reporter mouse to increase the low recombination efficiency.

Human mesenchymal factors induce rat hippocampal- and human neural stem cell dependent oligodendrogenesis.

The generation of new oligodendrocytes is essential for adult brain repair in diseases such as multiple sclerosis. We previously identified the multifunctional p57kip2 protein as a negative regulator of myelinating glial cell differentiation and as an intrinsic switch of glial fate decision in adult neural stem cells (aNSCs). In oligodendroglial precursor cells (OPCs), p57kip2 protein nuclear exclusion was recently found to be rate limiting for differentiation to proceed. Furthermore, stimulation with mesenchymal stem cell (MSC)-derived factors enhanced oligodendrogenesis by yet unknown mechanisms. To elucidate this instructive interaction, we investigated to what degree MSC secreted factors are species dependent, whether hippocampal aNSCs respond equally well to such stimuli, whether apart from oligodendroglial differentiation also tissue integration and axonal wrapping can be promoted and whether the oligodendrogenic effect involved subcellular translocation of p57kip2. We found that CC1 positive oligodendrocytes within the hilus express nuclear p57kip2 protein and that MSC dependent stimulation of cultured hippocampal aNSCs was not accompanied by nuclear p57kip2 exclusion as observed for parenchymal OPCs after spontaneous differentiation. Stimulation with human MSC factors was observed to equally promote rat stem cell oligodendrogenesis, axonal wrapping and tissue integration. As forced nuclear shuttling of p57kip2 led to decreased CNPase- but elevated GFAP expression levels, this indicates heterogenic oligodendroglial mechanisms occurring between OPCs and aNSCs. We also show for the first time that dominant pro-oligodendroglial factors derived from human fetal MSCs can instruct human induced pluripotent stem cell-derived NSCs to differentiate into O4 positive oligodendrocytes.

Pericytes Stimulate Oligodendrocyte Progenitor Cell Differentiation during CNS Remyelination.

The role of the neurovascular niche in CNS myelin regeneration is incompletely understood. Here, we show that, upon demyelination, CNS-resident pericytes (PCs) proliferate, and parenchymal non-vessel-associated PC-like cells (PLCs) rapidly develop. During remyelination, mature oligodendrocytes were found in close proximity to PCs. In Pdgfbret/ret mice, which have reduced PC numbers, oligodendrocyte progenitor cell (OPC) differentiation was delayed, although remyelination proceeded to completion. PC-conditioned medium accelerated and enhanced OPC differentiation in vitro and increased the rate of remyelination in an ex vivo cerebellar slice model of demyelination. We identified Lama2 as a PC-derived factor that promotes OPC differentiation. Thus, the functional role of PCs is not restricted to vascular homeostasis but includes the modulation of adult CNS progenitor cells involved in regeneration.

-759C>T Polymorphism of the HTR2C Gene is Associated with Second Generation Antipsychotic-Induced Weight Gain in Female Patients with Schizophrenia.

Introduction: The HTR2C gene is an important candidate in pharmacogenetic studies of antipsychotic-induced weight gain (AIWG). However, inconsistent results have been obtained. The present study investigated the association between -759C>T, functional polymorphism of the HTR2C receptor, and AIWG. Methods: A prospective cohort of 48 female inpatients with schizophrenia and related illness treated according to normal clinical practice with second generation antipsychotics (SGAs) risperidone, clozapine, quetiapine, and olanzapine were evaluated. Patients were weighted at admission and again at 6 weeks of hospitalization. Weight gain was defined as an increase≥7% of baseline weight. The association between polymorphisms HTR2C and weight gain was evaluated. Multiple logistic regression was run to determine potential confounders. Results: Patients with the T allele at position -759 (TT or CT) gained less weight as compared to patients who did not have the allele. This association was not affected by possible confounding factors such as age, baseline BMI, and prior psychopharmacological treatment. Discussion: The T allele at position -759 protects against AIWG in female patients with schizophrenia.

Theoretical studies on the interaction of partial agonists with the 5-HT2A receptor.

A series of 51 5-HT(2A) partial agonistic arylethylamines (primary or benzylamines) from different structural classes (indoles, methoxybenzenes, quinazolinediones) was investigated by fragment regression analysis (FRA), docking and 3D-QSAR approaches. The data, pEC(50) values and intrinsic activities (E(max)) on rat arteries, show high variability of pEC(50) from 4 to 10 and of E(max) from 15 to 70%. FRA indicates which substructures affect potency or intrinsic activity. The high contribution of halogens in para position of phenethylamines to pEC(50) points to a specific hydrophobic pocket. Other results suggest the significance of hydrogen bonds of the aryl moiety for activation and the contrary effect of benzyl groups on affinity (increasing) and intrinsic activity (decreasing). Results from fragment regression and data on all available mutants were considered to derive a common binding site at the rat 5-HT(2A) receptor. After generation and MD simulations of a receptor model based on the ß(2)-adrenoceptor structure, typical derivatives were docked, leading to the suggestion of common interactions, e.g., with serines in TM3 and TM5 and with a cluster of aromatic amino acids in TM5 and TM6. The whole series was aligned by docking and minimization of the complexes. The pEC(50) values correlate well with Sybyl docking energies and hydrophobicity of the aryl moieties. With this alignment, CoMFA and CoMSIA approaches based on a training set of 36 and a test set of 15 compounds were performed. The correlation of pEC(50) with steric, electrostatic, hydrophobic and H-bond acceptor fields resulted in sufficient fit (q (2): 0.75-0.8, r (2): 0.92-0.95) and predictive power (r (pred) (2) : 0.85-0.88). The important interaction regions largely reflect the patterns provided by the putative binding site. In particular, the fit of the aryl moieties and benzyl substituents to two hydrophobic pockets is evident.

Community Involvement in a Dengue Prevention Project in Malaria, Sao Paulo, State, Brazil

Since dengue fever has only recently appeared in the city of Marília, São Paulo, State, Brazil, and no fatal cases of the disease have yet to occur, dengue prevention is not a local priority. A dengue prevention program in one neighborhood made the tires, cans and bottles where mosquitoes breed its focus, and conducted an “ethnography of refuse,” including local classification of materials as useful or disposable in preparation for and educational intervention. The initial assumption was that patterns of refuse disposal are and individual choice, influenced by relatively static cultural definitions of what constitutes refuse. This gave way over the course of the project to a new, more dynamic and contextualized view, allowing for the influence of a system of selective refuse collection with participation of both householders and informal refuse collectors. The implications of the findings for programs to control other emerging infectious diseases are discussed.

Disposable containers a larval habitats for Aedes aegypti in city with regular refuse collection: a study in Marília, São Paulo State, Brazil

In Marilia, Brazil, refuse ins collected at least every other day, yet non-useful, non- returnable containers such as cans, plastic bottles and tires account for almost half of the container habitats found positive for the Aedes aegypti mosquito. A study was therefore conducted to investigate why these containers exist despite regular refuse collection and a high level of awareness of dengue prevention, and how the control program could most effectively respond. Differing community perceptions as to what constitutes refuse were found to lead people to store a variety of containers in their yard. Other dimensions of the problem include the presence of informal refuse collectors in search of saleable materials, and dumping of refuse in vacant lots and along roads. An intervention based on these data will involve the informal refuse collectors in implementation of a community-base recycling project.

Bacteremias en un hospital de cáncer. experiencia entre 1980 y 1993 en el INEN / Bacteremia at cancer hospital between 1980 and 1993

Con el objeto de evaluar la distribución epidemiológica de las bacteremias detectadas en el INEN entre 1980 y 1993 revisamos los archivos de la institución. Los gérmenes Gram positivos representan aproximadamente el 60 por ciento de la serie. Entre 1980 a 1984 el S. aureus fue el Gram positivo más frecuente y S. epidermidis entre 1985 y 1993. Los gérmenes negativos representaron el 40 por ciento del total y cinco fueron los más frecuentes: Pseudomona, E. coli, Klebsiella, Acinetobacter y Enterobacter.

Elaboración y administración de dos formas farmaceuticas preparadas con sangre de ganado vacuno, Sucre 1988

Segun la OMS, la anemia es una de las enfermeades mas frecuentemente observadas en el mundo de hoy. Es especialmente prevalente en los niños pequeños y en las mujeres en edadde reproducción, sobre todo durante el embarazo. Las causas de la anemia son multiples, pero es indudable que los niños y las mujeres son afectados porque sus necesidades de hierro son elevadas y Bolivia no constituye una excepción. La deficiencia de hierro ejerce sin embargo ademas de la anemia, un profundo afecto sobre el comportamiento psicologico y fisico del sujeto. Las anemias leves y moderadas mucho mas frecuentes, se toleran mas o menos bien en circunstancias normales no obstante, reducen la resistencia a las infeciones y afectan a la capacidad del trabajo en condiciones de tensión; incluso las formas muy leves alteran la sensación de bienestar. Resulta por lo tanto, evidente que ante la magnitud que alcanza en el ser humano, los esfuerzos deben encausarse hacia la prevención y el tratamiento. El empleo de sangre vacuna por su alto contenido en hierro resulta el metodo mas practico para curar la anemia carencial en la población. Con esta finalidad se diseño un trabajo observacinal, analitico y prospectivo. La mayoria de los medicamentos antianemicos, llevan en mayor o en menor proporción hierro inorganico al estado de sales, sobre todo sulfato; sin embargo se ha demostrado en estudios últimos que el hierro presente en la hemoglobina, tiene un mecanismo de absorción superior al hierro inorganico por su alta biodisponibilidad. Es esta la razón del presente trabajo para demostrar que el producto farmaceutico obtenido de sangre vacuna cura la anemia a corto plazo y siendo de bajo costo, puede llegar a las clases de bajos recursos economicos...