477 research outputs found
Long-term melatonin treatment reduces ovarian mass and enhances tissue antioxidant defenses during ovulation in the rat
Melatonin regulates the reproductive cycle, energy metabolism and may also act as a potential antioxidant indoleamine. The present study was undertaken to investigate whether long-term melatonin treatment can induce reproductive alterations and if it can protect ovarian tissue against lipid peroxidation during ovulation. Twenty-four adult female Wistar rats, 60 days old (± 250-260 g), were randomly divided into two equal groups. The control group received 0.3 mL 0.9% NaCl + 0.04 mL 95% ethanol as vehicle, and the melatonin-treated group received vehicle + melatonin (100 µg·100 g body weight-1·day-1) both intraperitoneally daily for 60 days. All animals were killed by decapitation during the morning estrus at 4:00 am. Body weight gain and body mass index were reduced by melatonin after 10 days of treatment (P < 0.05). Also, a marked loss of appetite was observed with a fall in food intake, energy intake (melatonin 51.41 ± 1.28 vs control 57.35 ± 1.34 kcal/day) and glucose levels (melatonin 80.3 ± 4.49 vs control 103.5 ± 5.47 mg/dL) towards the end of treatment. Melatonin itself and changes in energy balance promoted reductions in ovarian mass (20.2%) and estrous cycle remained extensive (26.7%), arresting at diestrus. Regarding the oxidative profile, lipid hydroperoxide levels decreased after melatonin treatment (6.9%) and total antioxidant substances were enhanced within the ovaries (23.9%). Additionally, melatonin increased superoxide dismutase (21.3%), catalase (23.6%) and glutathione-reductase (14.8%) activities and the reducing power (10.2% GSH/GSSG ratio). We suggest that melatonin alters ovarian mass and estrous cyclicity and protects the ovaries by increasing superoxide dismutase, catalase and glutathione-reductase activities.21722
The role of disulfide bond replacements in analogues of the Tarantula toxin ProTx-II and their effects on inhibition of the voltage-gated sodium ion channel Nav1.7
Spider venom toxins, such as Protoxin-II (ProTx-II), have recently received much attention as selective Nav1.7 channel blockers, with potential to be developed as leads for the treatment of chronic nocioceptive pain. ProTx-II is a 30-amino acid peptide with three disulfide bonds that has been reported to adopt a well-defined inhibitory cystine knot (ICK) scaffold structure. Potential drawbacks with such peptides include poor pharmacodynamics and potential scrambling of the disulfide bonds in vivo. In order to address these issues, in the present study we report the solid-phase synthesis of lanthionine-bridged analogues of ProTx-II, in which one of the three disulfide bridges is replaced with a thioether linkage, and evaluate the biological properties of these analogues. We have also investigated the folding and disulfide bridging patterns arising from different methods of oxidation of the linear peptide precursor. Finally, we report the X-ray crystal structure of ProTx-II to atomic resolution; to our knowledge this is the first crystal structure of an ICK spider venom peptide not bound to a substrate
Scalar meson dynamics in Chiral Perturbation Theory
A comparison of the linear sigma model (LM) and Chiral Perturbation
Theory (ChPT) predictions for pion and kaon dynamics is presented. Lowest and
next-to-leading order terms in the ChPT amplitudes are reproduced if one
restricts to scalar resonance exchange. Some low energy constants of the order
ChPT Lagrangian are fixed in terms of scalar meson masses. Present values
of these low energy constants are compatible with the LM dynamics. We
conclude that more accurate values would be most useful either to falsify the
LM or to show its capability to shed some light on the controversial
scalar physics.Comment: 9 pages, REVTeX 4.0. Final version accepted for publicatio
Radiative open charm decay of the Y(3940), Z(3930), X(4160) resonances
We determine the radiative decay amplitudes for decay into and , or and of some of the charmonium like
states classified as X,Y,Z resonances, plus some other hidden charm states
which are dynamically generated from the interaction of vector mesons with
charm. The mass distributions as a function of the or
invariant mass show a peculiar behavior as a consequence of
the nature of these states. The experimental search of these
magnitudes can shed light on the nature of these states.Comment: 18 pages, 9 figure
Study of the , , and in the radiative decays
In this paper we present an approach to study the radiative decay modes of
the into a photon and one of the tensor mesons ,
, as well as the scalar ones and .
Especially we compare predictions that emerge from a scheme where the states
appear dynamically in the solution of vector meson--vector meson scattering
amplitudes to those from a (admittedly naive) quark model. We provide evidence
that it might be possible to distinguish amongst the two scenarios, once
improved data are available.Comment: The large Nc argument improved; version published in EPJA
Perinatal Factors Associated With Early Deaths Of Preterm Infants Born In Brazilian Network On Neonatal Research Centers [fatores Perinatais Associados Ao óbito Precoce Em Prematuros Nascidos Nos Centros Da Rede Brasileira De Pesquisas Neonatais]
Objective: To evaluate perinatal factors associated with early neonatal death in preterm infants with birth weights (BW) of 400-1,500 g. Methods: A multicenter prospective cohort study of all infants with BW of 400-1,500 g and 23-33 weeks of gestational age (GA), without malformations, who were born alive at eight public university tertiary hospitals in Brazil between June of 2004 and May of 2005. Infants who died within their first 6 days of life were compared with those who did not regarding maternal and neonatal characteristics and morbidity during the first 72 hours of life. Variables associated with the early deaths were identified by stepwise logistic regression. Results: A total of 579 live births met the inclusion criteria. Early deaths occurred in 92 (16%) cases, varying between centers from 5 to 31%, and these differences persisted after controlling for newborn illness severity and mortality risk score (SNAPPE-II). According to the multivariate analysis, the following factors were associated with early intrahospital neonatal deaths: gestational age of 23-27 weeks (odds ratio - OR = 5.0; 95%CI 2.7-9.4), absence of maternal hypertension (OR = 1.9; 95%CI 1.0-3.7), 5th minute Apgar 0-6 (OR = 2.8; 95%CI 1.4-5.4), presence of respiratory distress syndrome (OR=3.1;95%CI 1.4-6.6), and network center of birth. Conclusion: Important perinatal factors that are associated with early neonatal deaths in very low birth weight preterm infants can be modified by interventions such as improving fetal vitality at birth and reducing the incidence and severity of respiratory distress syndrome. The heterogeneity of early neonatal rates across the different centers studied indicates that best clinical practices should be identified and disseminated throughout the country. Copyright © 2008 by Sociedade Brasileira de Pediatria.844300307Joseph, K.S., Liston, R.M., Dodds, L., Dahlgren, L., Allen, A.C., Socioeconomic status and perinatal outcomes in a setting with universal access to essential health care services (2007) CMAJ, 177, pp. 583-590Mathews, T.J., MacDorman, M.F., Infant mortality statistics from the 2004 period linked birth/infant death data set (2007) Natl Vital Stat Rep, 55, pp. 1-32Kramer, M.S., Demissie, K., Yang, H., Platt, R.W., Sauve, R., Liston, R., The contribution of mild and moderate preterm birth to infant mortality. Fetal and Infant Health Study Group of the Canadian Perinatal Surveillance System (2000) JAMA, 284, pp. 843-849Ananth, C.V., Vintzileos, A.M., Epidemiology of preterm birth and its clinical subtypes (2006) J Matern Fetal Neonatal Med, 19, pp. 773-782Brasil. Ministério da Saúde. DATASUS. Informaç ões de Saúde-Estatísticas Vitais- Mortalidade e Nascidos Vivos: nascidos vivos desde 1994. http://tabnet.datasus.gov.br/cgi/deftohtm.exe? sinasc/cnv/nvuf.def. Acesso: 29.10.2007Brasil. Ministério da Saúde. DATASUS. Informaç ões de Saúde-Estatísticas Vitais- Mortalidade e Nascidos Vivos: óbitos infantis - desde 1979. http://tabnet.datasus.gov.br/cgi/ deftohtm.exe?sim/cnv/infuf.def. Acesso: 29.10.2007Barros, F.C., Diaz-Rossello, J.L., The quality of care of very low birth weight babies in Brazil (2007) J Pediatr (Rio J), 83, pp. 5-6Horbar, J.D., Badger, G.J., Carpenter, J.H., Fanaroff, A.A., Kilpatrick, S., LaCorte, M., Trends in mortality and morbidity for very low birth weight infants, 1991-1999 (2002) Pediatrics, 110, pp. 143-151Fanaroff AA, Stoll BJ, Wright LL, Carlo WA, Ehrenkranz RA, Stark AR, et al. Trends in neonatal morbidity and mortality for very low birth weight infants. Am J Obstet Gynecol. 2007;196:147.e1-8(2004) Infra-estrutura para atendimento integral ao recém-nascido, , http://www.sbp.com.br/show_item2.cfm?id_categoria=21&id_detalhe=1636&tipo_detalhe=s.Access:02.11.2007, Departamento de Neonatologia da Sociedade Brasileira de PediatriaBallard, J.L., Khoury, J.C., Wedig, K., Wang, L., Eilers-Walsman, B.L., Lipp, R., New Ballard Score, expanded to include extremely premature infants (1991) J Pediatr, 119, pp. 417-423Alexander, G.R., Himes, J.H., Kaufman, R.B., Mor, J., Kogan, M., A United States national reference for fetal growth (1996) Obstet Gynecol, 87, pp. 163-168Kattwinkel, J., (2000) Textbook of Neonatal Resuscitation, , 4th ed. Chicago, IL: American Academy of Pediatrics/American Heart Association;Richardson, D.K., Corcoran, J.D., Escobar, G.J., Lee, S.K., SNAP-II and SNAPPE-II: Simplified newborn illness severity and mortality risk scores (2001) J Pediatr, 138, pp. 92-100El-Metwally D, Vohr B, Tucker R. Survival and neonatal morbidity at the limits of viability in the mid 1990s: 22 to 25 weeks. J Pediatr. 2000;137:616-22Costeloe, K., Hennessy, E., Gibson, A.T., Marlow, N., Wilkinson, A.R., The EPICure study: Outcomes to discharge from hospital for infants born at the threshold of viability (2000) Pediatrics, 106, pp. 659-671MacDonald, H., American Academy of Pediatrics. Committee on Fetus and Newborn. Perinatal care at the threshold of viability (2002) Pediatrics, 110, pp. 1024-1027Jain, L., Raju, T.N., editors. Late preterm pregnancy and the newborn (2006) Clin Perinatol, 33, pp. 751-972de Kleine, M.J., den Ouden, A.L., Kollee, L.A., Ilsen, A., van Wassenaer, A.G., Brand, R., Lower mortality but higher neonatal morbidity over a decade in very preterm infants (2007) Paediatr Perinat Epidemiol, 21, pp. 15-25Moro, M., Figueras-Aloy, J., Fernández, C., Doménech, E., Jiménez, R., Pérez-Rodríguez, J., Mortality for newborns of birthweight less than 1,500 g in Spanish neonatal units (2002-2005) (2007) Am J Perinatol, 24, pp. 593-601Drumond Ede, F., Machado, C.J., Franca, E., Early neonatal mortality: An analysis of multiple causes of death by the Grade of Membership method (2007) Cad Saude Publica, 23, pp. 157-166Richardson, D.K., Shah, B.L., Frantz 3rd, I.D., Bednarek, F., Rubin, L.P., McCormick, M.C., Perinatal risk and severity of illness in newborns at 6 neonatal intensive care units (1999) Am J Public Health, 89, pp. 511-516Horbar, J.D., Rogowski, J., Plsek, P.E., Delmore, P., Edwards, W.H., Hocker, J., Collaborative quality improvement for neonatal intensive care. NIC/Q Project Investigators of the Vermont Oxford Network (2001) Pediatrics, 107, pp. 14-22Vohr, B.R., Wright, L.L., Dusick, A.M., Perritt, R., Poole, W.K., Tyson, J.E., Center differences and outcomes of extremely low birth weight infants (2004) Pediatrics, 113, pp. 781-789Horbar JD, Plsek PE, Leahy KNIC/Q 2000. NIC/Q 2000: establishing habits for improvement in neonatal intensive care units. Pediatrics. 2003;111:e397-410Evans, N., Hutchinson, J., Simpson, J.M., Donoghue, D., Darlow, B., Henderson-Smart, D., Prenatal predictors of mortality in very preterm infants cared for in the Australian and New Zealand Neonatal Network (2007) Arch Dis Child Fetal Neonatal Ed, 92, pp. F34-F40Walther, F.J., Withholding treatment, withdrawing treatment, and palliative care in the neonatal intensive care unit (2005) EarlyHumDev, 81, pp. 965-972von Dadelszen, P., Magee, L.A., Taylor, E.L., Muir, J.C., Stewart, S.D., Sherman, P., Maternal hypertension and neonatal outcome among small for gestational age infants (2005) Obstet Gynecol, 106, pp. 335-339Casey, B.M., McIntire, D.D., Leveno, K.J., The continuing value of the Apgar score for the assessment of newborn infants (2001) N Engl J Med, 344, pp. 467-471,308-31
Idade ao primeiro parto e intervalo de partos de cinco grupos genéticos Holandês x Gir no Brasil
Central Pb+Pb Collisions at 158 A GeV/c Studied by Pion-Pion Interferometry
Two-particle correlations have been measured for identified negative pions
from central 158 AGeV Pb+Pb collisions and fitted radii of about 7 fm in all
dimensions have been obtained. A multi-dimensional study of the radii as a
function of kT is presented, including a full correction for the resolution
effects of the apparatus. The cross term Rout-long of the standard fit in the
Longitudinally CoMoving System (LCMS) and the vl parameter of the generalised
Yano-Koonin fit are compatible with 0, suggesting that the source undergoes a
boost invariant expansion. The shapes of the correlation functions in Qinv and
Qspace have been analyzed in detail. They are not Gaussian but better
represented by exponentials. As a consequence, fitting Gaussians to these
correlation functions may produce different radii depending on the acceptance
of the experimental setup used for the measurement.Comment: 13 pages including 10 figure
Development of the oral resistome during the first decade of life
Published online: 09 March 2023Antibiotic overuse has promoted the spread of antimicrobial resistance (AMR) with significant health and economic consequences. Genome sequencing reveals the widespread presence of antimicrobial resistance genes (ARGs) in diverse microbial environments. Hence, surveillance of resistance reservoirs, like the rarely explored oral microbiome, is necessary to combat AMR. Here, we characterise the development of the paediatric oral resistome and investigate its role in dental caries in 221 twin children (124 females and 97 males) sampled at three time points over the first decade of life. From 530 oral metagenomes, we identify 309 ARGs, which significantly cluster by age, with host genetic effects detected from infancy onwards. Our results suggest potential mobilisation of ARGs increases with age as the AMR associated mobile genetic element, Tn916 transposase was co-located with more species and ARGs in older children. We find a depletion of ARGs and species in dental caries compared to health. This trend reverses in restored teeth. Here we show the paediatric oral resistome is an inherent and dynamic component of the oral microbiome, with a potential role in transmission of AMR and dysbiosis.Smitha Sukumar, FangWang, Carra A. Simpson, Cali E. Willet, Tracy Chew, Toby E. Hughes, Michelle R. Bockmann, Rosemarie Sadsad, F. ElizabethMartin, Henry W. Lydecker, Gina V. Browne, KylieM. Davis, Minh Bui, ElenaMartinez, Christina J. Adle
Search for Disoriented Chiral Condensates in 158 AGeV Pb+Pb Collisions
The restoration of chiral symmetry and its subsequent breaking through a
phase transition has been predicted to create regions of Disoriented Chiral
Condensates (DCC). This phenomenon has been predicted to cause anomalous
fluctuations in the relative production of charged and neutral pions in
high-energy hadronic and nuclear collisions. The WA98 experiment has been used
to measure charged and photon multiplicities in the central region of 158 AGeV
Pb+Pb collisions at the CERN SPS. In a sample of 212646 events, no clear DCC
signal can be distinguished. Using a simple DCC model, we have set a 90% C.L.
upper limit on the maximum DCC production allowed by the data.Comment: 20 Pages, LaTeX, uses elsart.cls, 8 eps figures included, submitted
to Physics Letters
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