Presence of A. actinomycetemcomitans and P. gingivalis in young Chinese adults

published_or_final_versio

Therapeutic effects of chlorhexidine digluconate (CHX) in laborers with untreated gingivitis

published_or_final_versio

Uso de fármacos psicoestimulantes en drogodependencias

El uso de medicamentos estimulantes es una cuestión de plena actualidad en psiquiatría, aunque su utilización y prescripción es controvertida . Fármacos como el metilfenidato, las anfetaminas, o el modafinilo están siendo utilizados y estudiados en distintas enfermedades psiquiátricas como el trastorno por déficit de atención e hiperactividad (TDAH), la dependencia de cocaína, en trastornos del sueño y en la depresión resistente. Todos estos fármacos tienen en común, igual que las drogas de abuso, que son medicamentos que actúan sobre el sistema dopaminérgico, que constituye la base neurobiológica del refuerzo fisiológico. Los estimulantes como el metilfenidato o el modafinilo son fármacos eficaces en el TDAH y han sido estudiados en el tratamiento de la dependencia de cocaína. En niños con TDAH el metilfenidato es un factor protector para el desarrollo de fármaco en la dependencia de cocaína, aunque son estudios preliminares, por lo que no se debe considerar que este totalmente demostrado que los fármacos psicoestimulantes sean eficaces en el tratamiento de esta dependencia. Aunque no son conocidos todos los mecanismos fisiopatológicos, parece crítico que el refuerzo, y por lo tanto el riesgo de dependencia, aparece cuando se producen incrementos rápidos dopaminérgicos y que los efectos terapéuticos aparecen cuando son lentos y mantenidos. Las características de uso a dosis bajas administradas por vía oral disminuyen el riesgo de abuso. Para realizar una adecuada prescripción es necesario aclarar, definitivamente, los mecanismos neuroquímicos en los que intervienen, y sus indicaciones en drogodependenciasStimulant drugs prescription is a controversial and current topic in psychiatry. Drugs such as methylphenidate, amphetamine compounds and modafinil have been trialed and used in attention deficit hyperactivity disorder (ADHD), sleep conditions, cocaine dependence and as an adjunct to antidepressants for depression. All these drugs, like stimulant drugs abuse, increase extracellular dopamine in the brain.This effect is associated with reinforcing as well as therapeutic effects. Methylphenidate and modafinil treatment of ADHD are associated with a reduced risk for later substance abuse among ADHD patients. There is evidence of the beneficial effects of the use of modafinil in cocaine dependence, altough there isn't conclusive evidence for the stimulants' efficacy in treatment of the stimulants' dependence. At this time, the physiopathology of drug abuse and dependence is unknown, but it's known that the very critical point is that the reinforcing effects are associated with rapid changes in dopamine increases, whereas the therapeutic effects are associated with slowly and smoothly rising dopamine levels, such as are achieved with low doses and oral administration. Due to this, it's necessary to study the neurobiological bases on which stimulants drugs are related, and their clinical use in dependence treatment

The role of TcdB and TccC subunits in secretion of the photorhabdus Tcd toxin complex

The Toxin Complex (TC) is a large multi-subunit toxin encoded by a range of bacterial pathogens. The best-characterized examples are from the insect pathogens Photorhabdus, Xenorhabdus and Yersinia. They consist of three large protein subunits, designated A, B and C that assemble in a 5:1:1 stoichiometry. Oral toxicity to a range of insects means that some have the potential to be developed as pest control technology. The three subunit proteins do not encode any recognisable export sequences and as such little progress has been made in understanding their secretion. We have developed heterologous TC production and secretion models in E. coli and used them to ascribe functions to different domains of the crucial B+C sub-complex. We have determined that the B and C subunits use a secretion mechanism that is either encoded by the proteins themselves or employ an as yet undefined system common to laboratory strains of E. coli. We demonstrate that both the N-terminal domains of the B and C subunits are required for secretion of the whole complex. We propose a model whereby the N-terminus of the C-subunit toxin exports the B+C sub-complex across the inner membrane while that of the B-subunit allows passage across the outer membrane. We also demonstrate that even in the absence of the B-subunit, that the C-subunit can also facilitate secretion of the larger A-subunit. The recognition of this novel export system is likely to be of importance to future protein secretion studies. Finally, the identification of homologues of B and C subunits in diverse bacterial pathogens, including Burkholderia and Pseudomonas, suggests that these toxins are likely to be important in a range of different hosts, including man

Very Cold Gas and Dark Matter

We have recently proposed a new candidate for baryonic dark matter: very cold molecular gas, in near-isothermal equilibrium with the cosmic background radiation at 2.73 K. The cold gas, of quasi-primordial abundances, is condensed in a fractal structure, resembling the hierarchical structure of the detected interstellar medium. We present some perspectives of detecting this very cold gas, either directly or indirectly. The H$_2$ molecule has an "ultrafine" structure, due to the interaction between the rotation-induced magnetic moment and the nuclear spins. But the lines fall in the km domain, and are very weak. The best opportunity might be the UV absorption of H$_2$ in front of quasars. The unexpected cold dust component, revealed by the COBE/FIRAS submillimetric results, could also be due to this very cold H$_2$ gas, through collision-induced radiation, or solid H$_2$ grains or snowflakes. The $\gamma$-ray distribution, much more radially extended than the supernovae at the origin of cosmic rays acceleration, also points towards and extended gas distribution.Comment: 16 pages, Latex pages, crckapb macro, 3 postscript figures, uuencoded compressed tar file. To be published in the proceeedings of the "Dust-Morphology" conference, Johannesburg, 22-26 January, 1996, D. Block (ed.), (Kluwer Dordrecht

Analysis of a viral metagenomic library from 200 m depth in Monterey Bay, California constructed by direct shotgun cloning

<p>Abstract</p> <p>Background</p> <p>Viruses have a profound influence on both the ecology and evolution of marine plankton, but the genetic diversity of viral assemblages, particularly those in deeper ocean waters, remains poorly described. Here we report on the construction and analysis of a viral metagenome prepared from below the euphotic zone in a temperate, eutrophic bay of coastal California.</p> <p>Methods</p> <p>We purified viruses from approximately one cubic meter of seawater collected from 200m depth in Monterey Bay, CA. DNA was extracted from the virus fraction, sheared, and cloned with no prior amplification into a plasmid vector and propagated in <it>E. coli </it>to produce the MBv200m library. Random clones were sequenced by the Sanger method. Sequences were assembled then compared to sequences in GenBank and to other viral metagenomic libraries using BLAST analyses.</p> <p>Results</p> <p>Only 26% of the 881 sequences remaining after assembly had significant (E ≤ 0.001) BLAST hits to sequences in the GenBank nr database, with most being matches to bacteria (15%) and viruses (8%). When BLAST analysis included environmental sequences, 74% of sequences in the MBv200m library had a significant match. Most of these hits (70%) were to microbial metagenome sequences and only 0.7% were to sequences from viral metagenomes. Of the 121 sequences with a significant hit to a known virus, 94% matched bacteriophages (Families <it>Podo</it>-, <it>Sipho</it>-, and <it>Myoviridae</it>) and 6% matched viruses of eukaryotes in the Family <it>Phycodnaviridae </it>(5 sequences) or the Mimivirus (2 sequences). The largest percentages of hits to viral genes of known function were to those involved in DNA modification (25%) or structural genes (17%). Based on reciprocal BLAST analyses, the MBv200m library appeared to be most similar to viral metagenomes from two other bays and least similar to a viral metagenome from the Arctic Ocean.</p> <p>Conclusions</p> <p>Direct cloning of DNA from diverse marine viruses was feasible and resulted in a distribution of virus types and functional genes at depth that differed in detail, but were broadly similar to those found in surface marine waters. Targeted viral analyses are useful for identifying those components of the greater marine metagenome that circulate in the subcellular size fraction.</p

First trimester placental endothelial cells from pregnancies with abnormal uterine artery Doppler are more sensitive to apoptotic stimuli.

Failure of the placental capillary network to develop normally is associated with early onset fetal growth restriction (FGR) and pre-eclampsia (PE). Although the symptoms are observed at term, the problem begins in the first trimester. However, investigations at this clinically relevant time are hindered by difficulties in identifying earlystage pregnancies that are at risk of developing FGR/PE. Using uterine artery Doppler ultrasound in the first trimester as a proxy measure of poor placentation, we have identified pregnancies at increased risk of developing early onset FGR/PE. Placental endothelial cells (PEC) isolated from pregnancies at increased risk of developing FGR/PE grew more slowly and their basal rate of apoptosis was significantly higher than that seen in the normal group. The pro-apoptotic stimulus, TNFα, induced apoptosis in cells from both groups but this was significantly greater in the high risk group. TNF receptor expression was unaffected. Inhibition of nitric oxide (NO) production significantly increased the sensitivity of cells from the normal pregnancies to TNFα but not in the high risk group establishing a functional role for NO in this system. In conclusion, first trimester PEC from pregnancies at increased risk of developing early onset FGR/PE were inherently more sensitive to apoptotic stimuli and this was functionally linked to the synthesis of NO. This may contribute to the poor placental vascular development seen in on going pregnancies

2019 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations : summary from the basic life support; advanced life support; pediatric life support; neonatal life support; education, implementation, and teams; and first aid task forces

The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research