496 research outputs found
Kissing molars extraction: case series and review of the literature
Kissing molars are a very rare form of inclusion defined as molars included in the same quadrant, with occlusal
surfaces contacting each other within a single dental follicle.
We present four cases of this pathology: a 35 year-old male, referred to the Oral and Maxillofacial Surgery Department of the Hospital Virgen del Rocio in Seville, and three females of 24, 26, and 31 years, all of which had
kissing molars that were treated by tooth extraction.
We have found only 10 cases published in the medical literature in which this type of inclusion is briefly described,
none of which elaborate on the surgical technique employed. In these cases, the indication for surgery is established
when there is a history of recurring infections or cystic lesions associated with dental inclusions. The extraction of
kissing molars requires an exhaustive comprehension of the anatomy of the region involved, sufficiently developed
surgical abilities, and an extensive planning proces
Confirmation of SBS 1150+599A As An Extremely Metal-Poor Planetary Nebula
SBS 1150+599A is a blue stellar object at high galactic latitude discovered
in the Second Byurakan Survey. New high-resolution images of SBS 1150+599A are
presented, demonstrating that it is very likely to be an old planetary nebula
in the galactic halo, as suggested by Tovmassian et al (2001). An H-alpha image
taken with the WIYN 3.5-m telescope and its "tip/tilt" module reveals the
diameter of the nebula to be 9.2", comparable to that estimated from spectra by
Tovmassian et al. Lower limits to the central star temperature were derived
using the Zanstra hydrogen and helium methods to determine that the star's
effective temperature must be > 68,000K and that the nebula is optically thin.
New spectra from the MMT and FLWO telescopes are presented, revealing the
presence of strong [Ne V] lambda 3425, indicating that the central star
temperature must be > 100,000K. With the revised diameter, new central star
temperature, and an improved central star luminosity, we can constrain
photoionization models for the nebula significantly better than before. Because
the emission-line data set is sparse, the models are still not conclusive.
Nevertheless, we confirm that this nebula is an extremely metal-poor planetary
nebula, having a value for O/H that is less than 1/100 solar, and possibly as
low as 1/500 solar.Comment: 19 pages, 6 figures. Accepted for publication in the Astronomical
Journa
Instabilities of Higher-Order Parametric Solitons. Filamentation versus Coalescence
We investigate stability and dynamics of higher-order solitary waves in
quadratic media, which have a central peak and one or more surrounding rings.
We show existence of two qualitatively different behaviours. For positive phase
mismatch the rings break up into filaments which move radially to initial ring.
For sufficient negative mismatches rings are found to coalesce with central
peak, forming a single oscillating filament.Comment: 5 pages, 7 figure
Pase de visita en la comunidad / Medical rounds in the community
Durante el proceso de universalizaciĂłn se adoptan distintas formas de organizaciĂłn de la enseñanza (FOE), siendo la principal la EducaciĂłn en el Trabajo. El pase de visita en la comunidad es una modalidad de esta en los nuevos escenarios, debe ser preparada, organizada y dirigida por el profesor integral del consultorio. Se puede realizar en el PPU, domicilio, hogares maternos y de ancianos. Consta de varias etapas: organizaciĂłn exhaustiva de la actividad, etapa previa (estudio individual, recolecciĂłn de datos, mĂ©todo clĂnico), presentaciĂłn del paciente, (contexto familiar e higiĂ©nico-epidemiolĂłgico), análisis colectivo (pirámide docente), conclusiones (evalĂşa, corrige, motiva, esclarece, demuestra, orienta, aporta, enfatiza y comprueba), estudio individual y autoaprendizaje. Esta actividad desarrollada en la AtenciĂłn Primaria de Salud con estas caracterĂsticas, ha logrado integrar los aspectos clĂnicos, ambientales, familiares e higiĂ©nicos-epidemiolĂłgicos donde se desenvuelve el paciente. Palabras clave: ATENCIĂ“N PRIMARIA DE SALUD, DESARROLLO DE LA COMUNIDAD. ABSTRACT During the universalization process different forms of organizing learning process are introduced, being Education in Work the most important. Medical rounds in the community is a modality in the new contexts, the rounds must be prepared, organized and directed by the comprehensive professor of the Doctor's Office. The medical rounds can be conducted in the University Polyclinic, houses, maternal and old people's homes; having several stages: an exhaustive organization of the activity, a previous preparation (individual study, collection of data, clinical method), patient's presentation (familial and hygienic-epidemiologic context), collective analysis (teaching pyramid), conclusions (evaluate, correct, encourage, elucidate, demonstrate, advise, contribute, emphasize and confirm), individual study and self-learning. This activity, having these characteristics in Primary Health Care, facilitates the integration of the clinical, environmental, familial and hygienic-epidemiologic aspects where the patient becomes involve. Key words: Primary Health Care, community development
Case report: A combination of nitroglycerin and adenosine proves effective in repairing a cerebral arteriovenous malformation
Hemorrhage secondary to rupture of a brain arteriovenous malformations (AVM) is one of the initial manifestations, and the main cause of, morbidity and mortality in patients with this condition. Current treatment strategies include endovascular embolization with the goal of AVM obliteration and neurological preservation. In the transvenous endovascular embolization procedure, adenosine is the preferred agent to induce temporary hypotension and allow adequate AVM embolization. We describe the intraoperative management of an adenosine-resistant 38 year-old male who underwent a successful intracranial AVM embolization after concomitant administration of gradually increasing doses of nitroglycerin. This report suggests that nitroglycerin infusion can be combined with adenosine boluses to create a pronounced and dose-dependent hypotension in patients partially unresponsive to adenosine alone
Brain IGF-I regulates LTP, spatial memory and sexual dimorphic behavior
Insulin-like growth factor-I (IGF-I) exerts multiple actions, yet the role of IGF-I from different sources is poorly understood. Here, we explored the functional and behavioral consequences of the conditional deletion of Igf-I in the nervous system (Igf-I Δ/Δ), and demonstrated that long-term potentiation was impaired in hippocampal slices. Moreover, Igf-I Δ/Δ mice showed spatial memory deficits in the Morris water maze, and the significant sex-dependent differences displayed by Igf-I Ctrl/Ctrl mice disappeared in Igf-I Δ/Δ mice in the open field and rota-rod tests. Brain Igf-I deletion disorganized the granule cell layer of the dentate gyrus (DG), and it modified the relative expressions of GAD and VGLUT1, which are preferentially localized to inhibitory and excitatory presynaptic terminals. Furthermore, Igf-I deletion altered protein modules involved in receptor trafficking, synaptic proteins, and proteins that functionally interact with estrogen and androgen metabolism. Our findings indicate that brain IGF-I is crucial for long-term potentiation, and that it is involved in the regulation of spatial memory and sexual dimorphic behaviors, possibly by maintaining the granule cell layer structure and the stability of synaptic-related protein modules.We thank LucĂa Vicario (Instituto Cajal-CSIC, Madrid, Spain) for helping with the composition of the figures, and Dr. M Sefton (BiomedRed SL, Madrid, Spain) for English editing. This work was funded by grants from the Spanish “Ministerio Ciencia, InnovaciĂłn y Universidades, and the Ministerio de Ciencia e InnovaciĂłn/Agencia Estatal de InvestigaciĂłn” (MICIU and MICINN/AEI SAF2016-80419-R, PID2019-109059RB-100, and CIBERNED CB06/05/0065 to C Vicario; PID2019-110356RB-I00/AEI/10.13039/501100011033 to J Fernández-Irigoyen and E SantamarĂa; PID2019-104376RB-I00 to I Torres-Alemán; and PID2019-106579RB-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe to G Perea, and BES-2017-080303 to C González-Arias)
The Taurus Spitzer Survey: New Candidate Taurus Members Selected Using Sensitive Mid-Infrared Photometry
We report on the properties of pre-main-sequence objects in the Taurus
molecular clouds as observed in 7 mid- and far-infrared bands with the Spitzer
Space Telescope. There are 215 previously-identified members of the Taurus
star-forming region in our ~44 square degree map; these members exhibit a range
of Spitzer colors that we take to define young stars still surrounded by
circumstellar dust (noting that ~20% of the bonafide Taurus members exhibit no
detectable dust excesses). We looked for new objects in the survey field with
similar Spitzer properties, aided by extensive optical, X-ray, and ultraviolet
imaging, and found 148 candidate new members of Taurus. We have obtained
follow-up spectroscopy for about half the candidate sample, thus far confirming
34 new members, 3 probable new members, and 10 possible new members, an
increase of 15-20% in Taurus members. Of the objects for which we have
spectroscopy, 7 are now confirmed extragalactic objects, and one is a
background Be star. The remaining 93 candidate objects await additional
analysis and/or data to be confirmed or rejected as Taurus members. Most of the
new members are Class II M stars and are located along the same cloud filaments
as the previously-identified Taurus members. Among non-members with Spitzer
colors similar to young, dusty stars are evolved Be stars, planetary nebulae,
carbon stars, galaxies, and AGN.Comment: Accepted to ApJS. Two large online-only figures available with the
preprint here: http://web.ipac.caltech.edu/staff/rebull/research.htm
Primordial Circumstellar Disks in Binary Systems: Evidence for Reduced Lifetimes
We combine the results from several multiplicity surveys of pre-main-sequence
stars located in four nearby star-forming regions with Spitzer data from three
different Legacy Projects. This allows us to construct a sample of 349 targets,
including 125 binaries, which we use to to investigate the effect of companions
on the evolution of circumstellar disks. We find that the distribution of
projected separations of systems with Spitzer excesses is significantly
different (P ~2.4e-5, according to the KS test for binaries with separations <
400 AU) from that of systems lacking evidence for a disk. As expected, systems
with projected separations < 40 AU are half as likely to retain at least one
disk than are systems with projected separations in the 40-400 AU range. These
results represent the first statistically significant evidence for a
correlation between binary separation and the presence of an inner disk (r ~ 1
AU). Several factors (e.g., the incompleteness of the census of close binaries,
the use of unresolved disk indicators, and projection effects) have previously
masked this correlation in smaller samples. We discuss the implications of our
findings for circumstellar disk lifetimes and the formation of planets in
multiple systems.Comment: Accepted for publication by ApJ
Stable spinning optical solitons in three dimensions
We introduce spatiotemporal spinning solitons (vortex tori) of the
three-dimensional nonlinear Schrodinger equation with focusing cubic and
defocusing quintic nonlinearities. The first ever found completely stable
spatiotemporal vortex solitons are demonstrated. A general conclusion is that
stable spinning solitons are possible as a result of competition between
focusing and defocusing nonlinearities.Comment: 4 pages, 6 figures, accepted to Phys. Rev. Let
Limited dCTP Availability Accounts for Mitochondrial DNA Depletion in Mitochondrial Neurogastrointestinal Encephalomyopathy (MNGIE)
Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a severe human disease caused by mutations in TYMP, the gene encoding thymidine phosphorylase (TP). It belongs to a broader group of disorders characterized by a pronounced reduction in mitochondrial DNA (mtDNA) copy number in one or more tissues. In most cases, these disorders are caused by mutations in genes involved in deoxyribonucleoside triphosphate (dNTP) metabolism. It is generally accepted that imbalances in mitochondrial dNTP pools resulting from these mutations interfere with mtDNA replication. Nonetheless, the precise mechanistic details of this effect, in particular, how an excess of a given dNTP (e.g., imbalanced dTTP excess observed in TP deficiency) might lead to mtDNA depletion, remain largely unclear. Using an in organello replication experimental model with isolated murine liver mitochondria, we observed that overloads of dATP, dGTP, or dCTP did not reduce the mtDNA replication rate. In contrast, an excess of dTTP decreased mtDNA synthesis, but this effect was due to secondary dCTP depletion rather than to the dTTP excess in itself. This was confirmed in human cultured cells, demonstrating that our conclusions do not depend on the experimental model. Our results demonstrate that the mtDNA replication rate is unaffected by an excess of any of the 4 separate dNTPs and is limited by the availability of the dNTP present at the lowest concentration. Therefore, the availability of dNTP is the key factor that leads to mtDNA depletion rather than dNTP imbalances. These results provide the first test of the mechanism that accounts for mtDNA depletion in MNGIE and provide evidence that limited dNTP availability is the common cause of mtDNA depletion due to impaired anabolic or catabolic dNTP pathways. Thus, therapy approaches focusing on restoring the deficient substrates should be explored
- …