Polymerization of aniline hydrochloride in reverse of microemulsion by batch and semicontinuous process using ionic and nonionic surfactants.

The polymerization of aniline hydrochloride by inverse microemulsion in a batch process and the semicontinuous process was studied as a function of the surfactant ionic and nonionic. Polymerizations were carried out at 60°C for 4 h with a yield polymer of circa 67 and 27% wt. for ionic and nonionic surfactants. The conductivity of synthesized polyaniline by the semicontinuous process is higher up to three orders of magnitude than that of the batch process for both surfactants. The calculating degree of oxidation by UV-Vis showed the relative intensities of the quinoid to benzenoid unit around one. The morphology was determined by Scanning Electron Microscopy (SEM) and observed that the formation of the different morphologies is due to the self-assembly behavior of surfactant. The diameter z-average particle size (Dz) was studied by Transmission Electron Microscopy (TEM), which determined that the diameter particle in a semicontinuous state is larger than the one produced in a batch; this is due to the control of monomer addition in the system. These findings suggest that the polymerization process and the type of surfactant influence the properties of polyaniline.

Suprachoroidal hemorrhage due to Valsalva maneuver, importance of enhanced depth imaging optical coherence tomography in differential diagnosis.

We describe a case report of a spontaneous suprachoroidal hemorrhage, in which the enhanced depth imaging optical coherence tomography (OCT-EDI) is extremely useful in establish the differential diagnosis with a choroidal tumor. A 70 year-old woman was referred with a central scotoma after a Valsalva maneuver. In the posterior pole we observed a grey bilobed subretinal mass with the appearance of a choroidal tumor. OCT-EDI revealed an optically dark region with a scalloped anterior tumor contour and subretinal fluid, the choroicapillaris appeared to be intact and displaced anteriorly. The diagnosis was a suprachoroidal hemorrhage and it resolved in 12 weeks. Spontaneous suprachoroidal hemorrhage is a rare condition and it can resemble choroidal tumor. OCT-EDI is a very valuable tool in the differentiation of hemorrhage from tumors.

UV-initiated crosslinking of electrospun chitosan/poly(ethylene oxide) nanofibers doped with ZnO-nanoparticles: development of antibacterial nanofibrous hydrogel.

UV-initiated crosslinking of electrospun poly(ethylene) oxide (PEO)/chitosan (CS) nanofibers doped with zinc oxide nanoparticles (ZnO-NPs) was performed using pentaerythritol triaclyrate (PETA) as the photoinitiator and crosslinker agent. The influence of the addition of PETA to the PEO/CS diameter and crosslinking of nanofibers was evaluated. The effect of irradiation time on the morphology and swelling properties of the crosslinked nanofibers were investigated. For ZnO-NPs, the minimum inhibitory concentrations were found at 1 mg/mL, and the minimum bactericidal concentrations at 2 mg/mL for all the strains tested. The nanofibrous hydrogel antibacterial effect was tested. This material enters the realm of fibrous hydrogels which have potential use in several applications as in the biomedical area. SUPPLEMENTARY MATERIAL: The supplementary material for this article can be found at 10.1557/mrc.2020.74.

Structural complexes in the squid giant axon membrane sensitive to ionic concentrations and cardiac glycosides.

Giant nerve fibers of squid Sepioteuthis sepioidea were incubated for 10 min in artificial sea water (ASW) under control conditions, in the absence of various ions, and in the presence of cardiac glycosides. The nerve fibers were fixed in OsO4 and embedded in Epon, and structural complexes along the axolemma were studied.

Fine structural localization of cholesterol-1,2- 3 H in degenerating and regenerating mouse sciatic nerve.

The localization of (3)H-labeled cholesterol in nerves undergoing degeneration and regeneration was studied by radioautography at the electron microscope level. Two types of experiments were carried out: (a) Cholesterol-1,2-(3)H was injected intraperitoneally into suckling mice. 5 wk later, Wallerian degeneration was induced in the middle branch of the sciatic nerve, carefully preserving the collateral branches. The animals were then sacrificed at various times after the operation. During degeneration, radioactivity was found over myelin debris and fat droplets. In early stages of regeneration, radioactivity was found in myelin debris and regenerating myelin sheaths. Afterwards, radioactivity was found predominantly over the regenerated myelin sheaths. Radioactivity was also associated with the myelin sheaths of the unaltered fibers, (b) Wallerian degeneration was induced in the middle branch of the sciatic nerves of an adult mouse, preserving the collateral branches. Cholesterol-1,2-(3)H was injected 24 and 48 hr after the operation and the animal was sacrificed 6 wk later. Radioactivity was found in the myelin sheaths of the regenerated and unaltered fibers. The results from these experiments indicate that: (a) exogenous cholesterol incorporated into peripheral nerve during myelination remains within the nerve when it undergoes degeneration. Such cholesterol is kept in the myelin debris as an exchangeable pool from which it is reutilized for the formation of the newly regenerating fibers, especially myelin. (b) exogenous cholesterol incorporated into the nerves at the time that degeneration is beginning is also used in the formation of new myelin sheaths during regeneration, (c) mature myelin maintains its ability to incorporate cholesterol.

Comparative transcriptome analysis of the human endocervix and ectocervix during the proliferative and secretory phases of the menstrual cycle.

Despite extensive studies suggesting increased susceptibility to HIV during the secretory phase of the menstrual cycle, the molecular mechanisms involved remain unclear. Our goal was to analyze transcriptomes of the endocervix and ectocervix during the proliferative and secretory phases using RNA sequencing to explore potential molecular signatures of susceptibility to HIV. We identified 202 differentially expressed genes (DEGs) between the proliferative and secretory phases of the cycle in the endocervix (adjusted p < 0.05). The biofunctions and pathways analysis of DEGs revealed that cellular assembly and epithelial barrier function in the proliferative phase and inflammatory response/cellular movement in the secretory phase were among the top biofunctions and pathways. The gene set enrichment analysis of ranked DEGs (score = log fold change/p value) in the endocervix and ectocervix revealed that (i) unstimulated/not activated immune cells gene sets positively correlated with the proliferative phase and negatively correlated with the secretory phase in both tissues, (ii) IFNγ and IFNα response gene sets positively correlated with the proliferative phase in the ectocervix, (iii) HIV restrictive Wnt/ß-catenin signaling pathway negatively correlated with the secretory phase in the endocervix. Our data show menstrual cycle phase-associated changes in both endocervix and ectocervix, which may modulate susceptibility to HIV.

Vitreous haemorrhage a rare manifestation of retinal astrocytic hamartoma: a paediatric case report. / Hemorragia vítrea una rara manifestación del hamartoma astrocítico retiniano: a propósito de un caso pediátrico.

INTRODUCTION: Retinal astrocytic hamartoma is generally an asymptomatic benign tumour that may or may not be associated with the tuberous sclerosis complex. Haemorrhage is a rare presentation. CASE REPORT: The case concerns a 12-year-old patient with "a black spot" vision in the upper temporal hemifield of the right eye, who referred a similar episode 2 years ago. The anterior pole was normal in the slit lamp. A mass of translucent white-yellow peri-papillary appearance and vitreous peri-papillary haemorrhage was observed in funduscopy. The autofluorescence, fluorescence angiography, and optical coherence tomography characteristics were all compatible with retinal astrocytic hamartoma. Complementary studies (serology and X-rays) and the complete clinical examination rule out associated systemic involvement. The patient was followed-up closely until the vitreous haemorrhage was reabsorbed. CONCLUSION: Vitreous haemorrhage is a rare complication of Retinal astrocytic hamartoma and funduscopic exploration is difficult. Systemic involvement should be ruled out.

Semaphorin3a disrupts podocyte foot processes causing acute proteinuria.

Semaphorin3a was discovered as a secreted guidance protein that acts as a chemorepellent to migrating axons and endothelial cells. In the adult mouse kidney, it is expressed in podocytes and collecting tubules. Here, we show that exogenous semaphorin3a caused acute nephrotic range proteinuria associated with podocyte foot process effacement and fusion, endothelial cell damage, decreased vascular endothelial growth factor-A receptor expression, and downregulation of the slit-diaphragm proteins podocin, nephrin, and CD2-associated protein. When vascular endothelial growth factor 165 was administered at the same time as Semaphorin3a, no proteinuria or renal ultrastructural abnormalities occurred, suggesting that semaphorin3a effects may be mediated, in part, by downregulation of vascular endothelial growth factor receptor 2 signaling. Our findings indicate that a balance of semaphorin3a to vascular endothelial growth factor-A may be important for glomerular filtration barrier homeostasis.

Utilization of centrate for the outdoor production of marine microalgae at pilot-scale in flat-panel photobioreactors.

The outdoor production of marine microalgae biomass in pilot scale flat panels photobioreactors, under not sterile conditions and using centrate as nutrients source, was studied. Experiments were performed modifying the centrate percentage, dilution rate and orientation of the photobioreactors. The strain Geitlerinema sp. was that one prevailing independently of the culture conditions. The higher productivity of 47.7 gbiomass m-2·day-1 dry weight and photosynthetic efficiency of 2.8%, was achieved when using 20% centrate and a dilution rate of 0.3 day-1, whatever the orientation of the reactor, maximal nutrient removal capacities of 82%, 85% and 100% for carbon, nitrogen and phosphorus being obtained. Under non-optimal conditions up to 80% of the nitrogen and 60% of the phosphorus were lost by stripping and precipitation, respectively. Carbohydrates was the major component of the biomass followed by proteins and lipids. These results support the possibility to produce microalgae biomass below 0.59 €/kg, useful to produce biofertilizers and animal feed.

Anemone toxin II receptor site of the lobster nerve sodium channel. Studies in membrane vesicles and in proteoliposomes.

The receptor-site for the sea anemone toxin II from Anemonia sulcata (ATX) and its functional relationship with the Na+ channel were studied in plasma membrane preparations from lobster walking leg nerves. The modification of the 22Na influx by ATX was determined in membrane vesicles and in proteoliposomes prepared by reconstitution of detergent-extracted, unfractionated membrane particles into soybean liposomes. The effects of two other toxins, veratridine (VER) and tetrodotoxin (TTX), which bind to Na+ channel receptor-sites other than that for polypeptide toxins, were also studied, ATX and VER stimulated 22Na flux into membrane vesicles with K0.5 values in the order of 10(-7) and 10(-5) M, respectively. Positive cooperativity among these toxins was also seen; ATX displaces the K0.5 for VER towards lower VER concentrations. TTX abolishes the 22Na influx increment caused by ATX and/or VER with a K0.5 in the order of 10(-8) M. In proteoliposomes, in contrast, ATX modified the 22Na influx only at high concentrations (greater than 1 microM) and in the presence of VER. VER stimulation and TTX inhibition of the VER and the VER plus ATX modified fluxes, had the same characteristics as in the vesicle preparations. Measurable ATX and VER toxin effects were only seen in the presence of an outwardly directed K+ gradient for both vesicles and proteoliposomes. Detergent treatment and the reconstitution procedure seem to affect the functional properties of the ATX receptor site whereas the VER and the TTX sites remain unaltered.

The lobster nerve sodium channel: solubilization and purification of the tetrodotoxin receptor protein.

Solubilization and purification of the tetrodotoxin (TTX) binding protein of the lobster walking-leg nerve Na+ channel were carried out utilizing [3H]tetrodotoxin [( 3H]tetrodotoxin) as a marker. The nerve membrane was solubilized with Lubrol-PX and the Na+ channel protein was purified with diethylaminoethyl Bio-Gel A, Bio-Gel hydroxylapatite powder and two Sepharose 6B columns. Care was taken to keep the temperature of the Na+ channel preparation as close to 1 degrees C as possible and to use solutions (pH 7.5) that contain Na channel protectors, i.e., egg phosphatidylcholine/Lubrol-PX mixture, TTX, EDTA, EGTA, phenylmethylsulfonyl fluoride, pepstatin A, iodoacetamide, antipain, phosphoramidon, soybean trypsin inhibitor, leupeptin and bacitracin. From an initial specific binding of 20.1 pmol of [3H]TTX/mg protein for the solubilized membrane, the binding increased to 1241 pmol/mg protein for the most active fraction of the last Sepharose 6B column. The [3H]TTX specific binding of the Sepharose 6B fractions correlated with a large peptide of Mr 260,000 (240-280K), although other peptides were also present in lesser amounts.

The polypeptide and the phospholipid components of axon plasma membranes.

The axon plasma membrane fraction isolated from garfish olfactory nerve was analyzed for its polypeptide composition by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. There were present over 20 well-resolved polypeptide components in this membrane, and eleven of them, with an apparent molecular weight range of 22,000-130,000, accounted for most of the membrane proteins. None of the major polypeptide species present in the membrane appeared to be glycoprotein. Based on electrophoretic mobility on sodium dodecyl sulfate-polyacrylamide gel, eight of the major polypeptides found in garfish nerve membrane appeared to be also present in the axon plasma membrane isolated from lobster walking leg nerve. Both garfish and lobster nerve membranes contained high concentration of lipids (66-76%) which were essentially cholesterol and phospholipids. The classes of phospholipids present were phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol and sphingomyelin. Lobster nerve membrane also contained about 3% phosphatidic acid. Assays for acetylcholinesterase in axon plasma membrane fractions isolated from different nerve sources showed a wide variation, ranging from a specific activity of 2.4 for garfish nerve to 312.5 for lobster nerve membrane.

Nonelectrolyte penetration and sodium fluxes through the axolemma of resting and stimulated medium sized axons of the squid Doryteuthis plei.

The penetration of (14)C-labeled erythritol, mannitol, and sucrose through the axolemma was determined in medium sized paired axons, one at rest and the other stimulated 25 times per sec. The resting permeabilities, in 10(-7) cm/sec, are erythritol, 2.9 +/- 0.3 (mean +/- SEM); mannitol, 2.3 +/- 0.4; and sucrose 0.9 +/- 0.1. In the stimulated axons they are: erythritol, 5.2 +/- 0.3; mannitol, 4.0 +/- 0.5; and sucrose, 1.8 +/- 0.3. Thus, the calculated permeabilities during activity (1 msec per impulse), in the same units, are: 100, 75, and 38, respectively. These changes in permeability are reversible. The effects of external potassium and sodium concentrations on erythritol penetration were also studied. At rest, erythritol penetration is independent of potassium and sodium concentrations. In the stimulated axons, erythritol penetration decreases when the extracellular sodium is diminished. Sodium influx (not the efflux) decreases during rest and activity when the extracellular sodium is diminished. The diminution during activity of erythritol and sodium entries in low sodium solutions may be related to a decrease of a drag effect of sodium ions on the nonelectrolyte molecules or to independent effects of the sodium concentration on sodium influx and the nonelectrolyte pathways. The axolemma discriminates among erythritol, mannitol, sucrose, and the different ionic species during rest and activity.

Nonelectrolyte permeability, sodium influx, electrical potentials, and axolemma ultrastructure in squid axons of various diameters.

The penetration of (14)C-labeled ethylene glycol, erythritol, mannitol, and sucrose was measured in giant axons of various diameters isolated from the hindmost stellar nerves of Doryteuthis plei squid. Axon diameter depends mainly on the age of the squid. The influx of (22)Na, some electrical properties, and the ultrastructure of the axolemma were also studied. The results confirm our previous observation that in medium sized axons of D. plei stimulation causes an increase in the permeability to the penetration of erythritol, mannitol, and sucrose. They also demonstrate that the magnitude of the increase in the penetration of these probing molecules diminishes progressively as the axon diameter increases. The diminution in permeability may be due to a reduction in size of the pathways used by nonelectrolytes to enter the axon. No effect of stimulation on the ethylene glycol permeability is observed. The sodium influx and electrical properties are independent of axon size. The ultrastructural study shows that the axolemma thickness increases with axon diameter. The present experiments indicate that the nonelectrolyte permeability of stimulated axons depends on nerve fiber properties related to axon diameter and on the size of the hydrophilic nonelectrolyte probe.

Order-disorder phenomena in myelinated nerve sheaths. IV. The disordering effects of high levels of local anaesthetics on rat sciatic and optic nerves.

Sequences of 15 minute X-ray scattering spectra were recorded with rat sciatic and optic nerves, superfused with tetracaine-containing Ringer solutions. The spectra were analysed using the algorithm advocated in this series of papers. The main results, as a function of the time of exposure to tetracaine, were: the mean value of the repeat distance increases; its variance decreases; the average number of membrane pairs per coherent domain decreases; the fraction of isolated membrane pairs increases. Eventually, the spectra were observed to give way to the continuous intensity curve of a single, isolated membrane pair. At all stages of the experiment the continuous intensity curves were found to differ from one type of nerve to the other, and to be invariant, for each type of nerve, with respect to the tetracaine treatment. The X-ray scattering study clearly identified the nature of the structural differences between the two types of myelin sheaths: in that of native sciatic nerves, packing disorder preferentially affects the cytoplasmic space of the membrane pair, and tetracaine disrupts the packing in that space; in the myelin of optic nerves it is the external space that is preferentially affected by packing disorder and disrupted by tetracaine. The time-course of the structure parameters showed that, at any stage of the experiment, tetracaine acts preferentially on the more highly disordered regions of the structure and totally disrupts them. These results corroborate earlier conclusions reported in the previous papers of this series. An electron microscope study was also performed on tetracaine-treated nerves: the results, in close agreement with those of the X-ray scattering study, neatly confirm the conclusions given above. In a more general way, the remarkable agreement between the results of the analysis of the X-ray scattering spectra and the electron microscope observations strongly supports the validity of the physical model used in this series of papers and the correctness of the mathematical treatment that we advocate. Finally, the relations between this work and the work of others are discussed. It must be stressed that the present work bears on the toxic rather than on the anaesthetic effects of tetracaine.

Order-disorder phenomena in myelinated nerve sheaths: V. Effects of temperature on rat sciatic and optic nerves, and structural differences between the two types of nerve.

We describe in this work X-ray scattering and electron microscope studies of rat sciatic and optic nerves as a function of temperature. The scattering experiments were analyzed as described in the previous papers of this series: a variety of parameters were determined, some of which characterize the lattice disorder, others the structure of the motif. The main results are the following. All the parameters determined by the X-ray scattering study vary with temperature and the temperature-dependence is specific for the type of nerve (sciatic or optic). Most of the disorder-related parameters display a minimum or a maximum in the vicinity of physiological temperature (38 degrees C in rat); this observation, strongly supported by the electron microscope study, shows that the degree of organization of myelin is highest near physiological temperature. The structure of the motif, as revealed by the electron density profile, is fairly different in the two types of nerves (in contrast with the assumption made by previous workers); the structure also varies with temperature and the temperature-induced alterations are nerve-type specific. In the two types of nerve the thickness of the lipid bilayer varies with temperature as expected for a lipid-containing system with hydrocarbon chains in the disordered conformation. In sciatic nerve the thickness of the (thinner) cytoplasmic polar layer, which is also the layer most affected by lattice disorder in this type of nerve, decreases dramatically with increasing temperature. In optic nerve, in which lattice disorder predominantly affects the extracellular layer, the thickness of both the cytoplasmic and the extracellular layer is barely affected by temperature.

Asociación entre trastornos neurocognitivos según MiniMental State examination y control glicémico en Diabéticos Mayores de 80 años

Es conocida la relación entre la diabetes y la demencia según numerosos estudios, siendo estas enfermedades crónicas no transmisibles de gran impacto en la salud pública. En la actualidad existen diversos estudios sobre el control glicémico en pacientes diabéticos adultos mayores, población en la cual se han encontrado controversias sobre esta temática, específicamente en el control glicémico estricto, en especial en población muy mayor. El objetivo del estudio es determinar la asociación entre trastornos neurocognitivos según MiniMental State Examination y control glicémico adecuado en adultos mayores diabéticos de 80 años en comparación a los no controlados, atendidos en el Centro Médico Naval entre 2017 y 2018. Se realizó un estudio analítico, transversal, retrospectivo, análisis secundario de base de datos. La muestra final fue de 66 participantes. Se evaluó el control glicémico y el grado de trastorno neuro cognitivo (TNC). Se realizó un análisis descriptivo de las variables principales y un análisis bivariado comparando las covariables con la variable dependiente. Finalmente, las variables significativas en el análisis bivariado fueron incluidas en el modelo de regresión de Poisson. En los resultados se observó que el 92.42% no tuvo un control glicémico adecuado y presentaron trastornos neurocognitivos el 22.73% de los participantes. El valor de glucosa promedio en el grupo sin TNC fue de 99.53 ± 16.26 y del grupo con TNC el cual fue de 117.40 ± 55.01; además el valor de hemoglobina glicosilada fue en promedio de 7.96% ± 0.55 en el grupo con TNC y de 5.81 ± 0.54% en grupo sin TNC. En el modelo de regresión ajustado se obtuvo un valor de 1.13 (1.11-1.26). Se concluye que los pacientes con mal control glicémico tuvieron más riesgo de sufrir deterioro de la función cognitiva.

The relationship between diabetes and dementia is well known according to múltiple studies. These non-transmissible chronic conditions have a great impact in public health. Nowadays there are several studies that discuss the glycemic control in elderly diabetic patients and there have been controversies about this topic, especially in the strict glycemic management in very old populations. The objective of the study is to determine the relationship between cognitive impairment according to MiniMental State Examination procedure in appropriately controlled glycemic index in 80 years old diabetic adults versus not appropriately controlled, who were monitored at the Navy Medical Center between 2017 and 2018. The research consisted of an analytical, transversal and retrospective secondary analysis of a database. The final sample consisted of 66 participants. The glycemic control and the degree of neurocognitive impairment were evaluated. A descriptive analysis of the main variables was made and a bivariate analysis comparing the covariables with the dependent variable. Finally, all the meaningful variables in the bivariate analysis were included in the Poisson regression model. In the results it was observed that 92.42% did not have and adequate glycemic control and 22.73% of those presented neurocognitive impairments (NCI). The mean glucose value in the group without NCI was 99.53 ±16.26 and the group with NCI 117.40 ± 55.01. Furthermore, the glycosylated hemoglobin was on average of 7.96% ± 0.55 in the NCI group and 5.81 ± 0.54 % in the group without NCI. In the adjusted regression model, the value obtained was 1.13 (1.11-1.26). It was concluded that the patients with an inadequate glycemic control were more at risk of suffering cognitive decline.

Preparation by coaxial electrospinning and characterization of membranes releasing (-) epicatechin as scaffold for tissue engineering.

Optimal conditions for the preparation of a composite material of fibers of cellulose acetate (CA) and poly(vinyl pyrrolidone) (PVP), containing epicatechin (Epic) within the fiber CA/PVP-Epic/CA, were found. The morphology and physical/chemical properties of the fibrous membranes containing CA, PVP, and epicatechin were characterized using FTIR spectroscopy, thermal analysis, SEM, TEM, and natural weathering. Also, mechanical characterization of the fibers showed that tensile strength of the membrane was not affected by the presence of epicatechin within the fiber as compared with fibers without epicatechin. The effect of the medium on the release rate of epicatechin was also studied. The amount of epicatechin release was higher in water, 79.6%, and 31% in MesenCult medium. These results showed that these composite materials are recommended for cardiac tissue engineering; furthermore, using these materials allows precise release of the epicatechin in the damaged tissue.

Particulate air pollution and daily mortality on Utah's Wasatch Front.

Reviews of daily time-series mortality studies from many cities throughout the world suggest that daily mortality counts are associated with short-term changes in particulate matter (PM) air pollution. One U.S. city, however, with conspicuously weak PM-mortality associations was Salt Lake City, Utah; however, relatively robust PM-mortality associations have been observed in a neighboring metropolitan area (Provo/Orem, Utah). The present study explored this apparent discrepancy by collecting, comparing, and analyzing mortality, pollution, and weather data for all three metropolitan areas on Utah's Wasatch Front region of the Wasatch Mountain Range (Ogden, Salt Lake City, and Provo/Orem) for approximately 10 years (1985-1995). Generalized additive Poisson regression models were used to estimate PM-mortality associations while controlling for seasonality, temperature, humidity, and barometric pressure. Salt Lake City experienced substantially more episodes of high PM that were dominated by windblown dust. When the data were screened to exclude obvious windblown dust episodes and when PM data from multiple monitors were used to construct an estimate of mean exposure for the area, comparable PM-mortality effects were estimated. After screening and by using constructed mean PM [less than/equal to] 10 microm in aerodynamic diameter (PM10) data, the estimated percent change in mortality associated with a 10-mg/m3 increase in PM10 (and 95% confidence intervals) for the three Wasatch Front metropolitan areas equaled approximately 1. 6% (0.3-2.9), 0.8% (0.3-1.3), and 1.0% (0.2-1.8) for the Ogden, Salt Lake City, and Provo/Orem areas, respectively. We conclude that stagnant air pollution episodes with higher concentrations of primary and secondary combustion-source particles were more associated with elevated mortality than windblown dust episodes with relatively higher concentrations of coarse crustal-derived particles.

A real-time quantitative PCR comparative study between rat optic and sciatic nerves: determination of neuregulin-1 mRNA levels.

Injured axons from peripheral nervous system (PNS) possess the ability to regenerate. In contrast, regeneration of injured axons does not occur in the central nervous system (CNS) or occurs to a limited extent. Previous works have shown that rat sciatic nerve conditioned medium (CM) produced PC12 cells neuronal-like differentiation and neurite outgrowth. In the present work, we compared the expression of neuregulin-1s (NRG-1s) from rat sciatic and optic nerves as members of the PNS and CNS, respectively. Sciatic nerve CM showed a higher neurotrophic activity on PC12 cells than rat optic nerve CM. RT-PCR analysis verified the presence of all three types of NRG-1 mRNAs and their receptors in both types of nerves. Real-time quantitative PCR (QPCR) assays showed that the relative expression levels of all three types of NRG-1 mRNAs were higher in optic nerves than in sciatic nerves. Eleven-day cultured optic nerves showed an increased in NDF and SMDF when compared to freshly isolated optic nerves, whereas GGF decreased. However, 11-day-cultured sciatic nerves only showed an increase in SMDF mRNA. Western blots corroborated the differences in NRG-1 expression profile for both types of nerves and their CMs. Incubation of both CMs with the anti-pan-NRG-1 antibody showed that the neurotrophic activity of the optic nerve CM increased, whereas the sciatic nerve CM remained unchanged. These results indicated that different NRG-1 levels are expressed upon nerve degeneration and the balance between those levels and other neurotrophic factors could have an important role on nerve regeneration.