Extra-axonal contribution to double diffusion encoding-based pore size estimates in the corticospinal tract.

OBJECTIVE: To study the origin of compartment size overestimation in double diffusion encoding MRI (DDE) in vivo experiments in the human corticospinal tract. Here, the extracellular space is hypothesized to be the origin of the DDE signal. By exploiting the DDE sensitivity to pore shape, it could be possible to identify the origin of the measured signal. The signal difference between parallel and perpendicular diffusion gradient orientation can indicate if a compartment is regular or eccentric in shape. As extracellular space can be considered an eccentric compartment, a positive difference would mean a high contribution to the compartment size estimates. MATERIALS AND METHODS: Computer simulations using MISST and in vivo experiments in eight healthy volunteers were performed. DDE experiments using a double spin-echo preparation with eight perpendicular directions were measured in vivo. The difference between parallel and perpendicular gradient orientations was analyzed using a Wilcoxon signed-rank test and a Mann-Whitney U test. RESULTS: Simulations and MR experiments showed a statistically significant difference between parallel and perpendicular diffusion gradient orientation signals ([Formula: see text]). CONCLUSION: The results suggest that the DDE-based size estimate may be considerably influenced by the extra-axonal compartment. However, the experimental results are also consistent with purely intra-axonal contributions in combination with a large fiber orientation dispersion.

Evaluating the glymphatic system via magnetic resonance diffusion tensor imaging along the perivascular spaces in brain tumor patients.

PURPOSE: To investigate glymphatic system function in patients with brain tumors, including both primary and secondary tumors, using diffusion tensor imaging along perivascular spaces (DTI-ALPS). METHODS: We retrospectively analyzed the MR DTI of 24 patients with unilateral brain tumors and compared them with age and sex-matched controls. We compared the DTI-ALPS index of the ipsi- and contralateral brain hemispheres. The region of interest was placed in the periventricular vessels adjacent to the lateral ventricles. Differences between sex, age, and kind of tumor (primary or brain metastasis) were evaluated. Correlations between DTI-ALPS index and age and the tumor's apparent diffusion coefficient (ADC) were also investigated. RESULTS: The DTI-ALPS index was significantly lower (p < 0.05) in the tumor-affected hemisphere (mean = 1.26 ± 0.24) than contralateral (mean = 1.43 ± 0.28). A comparison with healthy controls revealed no significant difference on the matched ipsilateral side. However, the DTI-ALPS index of the contralateral side of the patients was larger than the HC. Additionally, no statistically significant differences were found when analyzing the DTI-ALPS index vs. age, sex, and tumor entity. Additionally, we did not find a correlation between the DTI-ALPS index and patient age or tumor ADC. CONCLUSION: The decreased DTI-ALPS index in the tumor-affected hemisphere may be related to impaired glymphatic system function. However, cancer is often a systemic disease; thus, the DTI-ALPS index from the contralateral brain hemisphere may not generally be considered as a normal control. Nonetheless, the DTI-ALPS index does not only reflect diffusion in the perivascular spaces but it can also be influenced by factors such as axonal degeneration. Therefore, it does not directly reflect brain waste clearance and changes in the index should be interpreted carefully.

Quantitative description of the morphology and ossification center in the axial skeleton of 20-week gestation formalin-fixed human fetuses using magnetic resonance images.

OBJECTIVES: Human tissues are usually studied using a series of two-dimensional visualizations of in vivo or cutout specimens. However, there is no precise anatomical description of some of the processes of human fetal development. The purpose of our study is to develop a quantitative description of the normal axial skeleton by means of high-resolution three-dimensional magnetic resonance (MR) images, collected from six normal 20-week-old human fetuses fixed in formaldehyde. METHODS: Fetuses were collected after spontaneous abortion and subsequently fixed with formalin. They were imaged using a 1.5 T MR scanner with an isotropic spatial resolution of 200 µm. The correct tissue discrimination between ossified and cartilaginous bones was confirmed by comparing the images achieved by MR scans and computerized axial tomographies. The vertebral column was segmented out from each image using a specially developed semi-automatic algorithm. RESULTS: Vertebral body dimensions and inter-vertebral distances were larger in the lumbar region, in agreement with the beginning of the ossification process from the thoracolumbar region toward the sacral and cephalic ends. CONCLUSION: In this article, we demonstrate the feasibility of using MR images to study the ossification process in formalin-fixed fetal tissues. A quantitative description of the ossification centers of vertebral bodies and arches is presented.

Influence of Spatial Resolution and Compressed SENSE Acceleration Factor on Flow Quantification with 4D Flow MRI at 3 Tesla.

Four-dimensional (4D) flow MRI allows quantifying flow in blood vessels-non invasively and in vivo. The clinical use of 4D flow MRI in small vessels, however, is hampered by long examination times and limited spatial resolution. Compressed SENSE (CS-SENSE) is a technique that can accelerate 4D flow dramatically. Here, we investigated the effect of spatial resolution and CS acceleration on flow measurements by using 4D flow MRI in small vessels in vitro at 3 T. We compared the flow in silicon tubes (inner diameters of 2, 3, 4, and 5 mm) measured with 4D flow MRI, accelerated with four CS factors (CS = 2.5, 4.5, 6.5, and 13) and three voxel sizes (0.5, 1, and 1.5 mm3) to 2D flow MRI and a flow sensor. Additionally, the velocity field in an aneurysm model acquired with 4D flow MRI was compared to the one simulated with computational fluid dynamics (CFD). A strong correlation was observed between flow sensor, 2D flow MRI, and 4D flow MRI (rho > 0.94). The use of fewer than seven voxels per vessel diameter (nROI) resulted in an overestimation of flow in more than 5% of flow measured with 2D flow MRI. A negative correlation (rho = -0.81) between flow error and nROI were found for CS = 2.5 and 4.5. No statistically significant impact of CS factor on differences in flow rates was observed. However, a trend of increased flow error with increased CS factor was observed. In an aneurysm model, the peak velocity and stagnation zone were detected by CFD and all 4D flow MRI variants. The velocity difference error in the aneurysm sac did not exceed 11% for CS = 4.5 in comparison to CS = 2.5 for all spatial resolutions. Therefore, CS factors from 2.5-4.5 can appear suitable to improve spatial or temporal resolution for accurate quantification of flow rate and velocity. We encourage reporting the number of voxels per vessel diameter to standardize 4D flow MRI protocols.

Metallic Implants in MRI - Hazards and Imaging Artifacts.

BACKGROUND: Magnetic resonance imaging (MRI) is an examination method for noninvasive soft tissue imaging without the use of ionizing radiation. Metallic implants, however, may pose a risk for the patient and often result in imaging artifacts. Due to the increasing number of implants, reducing these artifacts has become an important goal. In this review, we describe the risks associated with implants and provide the background on how metal-induced artifacts are formed. We review the literature on methods on how to reduce artifacts and summarize our findings. METHOD: The literature was searched using PubMed and the keywords "MRI metal artifact reduction", "metallic implants" and "MRI artefacts/artifacts". RESULTS AND CONCLUSION: The MRI compatibility of implants has to be evaluated individually. To reduce artifacts, two general approaches were found: a) parameter optimization in standard sequences (echo time, slice thickness, bandwidth) and b) specialized sequences, such as VAT, OMAR, WARP, SEMAC and MAVRIC. These methods reduced artifacts and improved image quality, albeit at the cost of a (sometimes significantly) prolonged scan time. New developments in accelerated imaging will likely shorten the scan time of these methods significantly, such that routine use may become feasible. KEY POINTS: · Metallic implants may pose a risk for patients and often cause artifacts.. · Imaging artifacts can be reduced by parameter optimization or special sequences.. · Metal artifacts are reduced with a lower TE, smaller voxel size, larger matrix, and higher bandwidth.. · SPI, STIR, VAT, SEMAC, MAVRIC, and MAVRIC-SL are specialized MR sequences that can reduce artifacts further.. CITATION FORMAT: · Peschke E, Ulloa P, Jansen O et al. Metallic Implants in MRI - Hazards and Imaging Artifacts. Fortschr Röntgenstr 2021; 193: 1285 - 1293.

Imaging Inflammation - From Whole Body Imaging to Cellular Resolution.

Imaging techniques have evolved impressively lately, allowing whole new concepts like multimodal imaging, personal medicine, theranostic therapies, and molecular imaging to increase general awareness of possiblities of imaging to medicine field. Here, we have collected the selected (3D) imaging modalities and evaluated the recent findings on preclinical and clinical inflammation imaging. The focus has been on the feasibility of imaging to aid in inflammation precision medicine, and the key challenges and opportunities of the imaging modalities are presented. Some examples of the current usage in clinics/close to clinics have been brought out as an example. This review evaluates the future prospects of the imaging technologies for clinical applications in precision medicine from the pre-clinical development point of view.

Characterization of allergic manifestations in dental professionals / Caracterización de manifestaciones alérgicas de profesionales en Odontología

Abstract The aim was to determine the prevalence and types of the allergies present among dental professionals in Costa Rica. We performed a cross-sectional study on 664 dentists who completed a self-reported questionnaire. A descriptive cross-sectional study with inferential analysis was carried out. Dentists reported allergies prior to studying dentistry in 39% of cases, 36% reported chronic illnesses, and 61% of the dentists reported first-degree relatives with some type of allergic reaction. Different allergies had a similar prevalence among the dental professionals (ranging between 19%-26%), all allergic manifestations occurred within the first 120 minutes after exposure. The average time of exposure to dentistry-related environments was 16 years (95% CI) among all the dentists surveyed. There is a positive correlation between the presence of a chronic illness and the predisposition to develop allergic reactions among dentists. In addition, there is a directly proportional relationship between age, time of exposure to dental environments, and the risk of developing allergic conditions to dental materials. The main adverse reactions reported due to exposure to dental materials, medicines and/or food were gastrointestinal, skin, and respiratory problems.

Resumen El objetivo del estudio fue determinar la prevalencia y tipo de alergias presentes entre los odontólogos en Costa Rica. Se realizó un estudio transversal descriptivo en 664 dentistas que completaron un cuestionario, utilizando análisis inferencial para el procesamiento de los resultados. Los odontólogos reportaron alergias previo a estudiar odontología en un 39% de los casos, el 36% informó enfermedades crónicas y el 61% de los dentistas mencionó tener familiares en primer grado que habían presentado algún tipo de reacción alérgica. Diferentes tipos de alergias tuvieron una prevalencia similar entre los odontólogos (oscilando entre el 19% y el 26%), todas las manifestaciones alérgicas ocurrieron dentro de los primeros 120 minutos después de la exposición al alergeno. El tiempo medio de exposición a entornos relacionados con la odontología fue de 16 años (IC del 95%) entre todos los dentistas encuestados. Existe una correlación positiva entre la presencia de una enfermedad crónica y la predisposición a desarrollar reacciones alérgicas entre los dentistas. Además, existe una relación directamente proporcional entre edad, tiempo de exposición a entornos dentales, y el riesgo de desarrollar reacciones alérgicas a los materiales dentales. Las principales reacciones adversas notificadas posterior a la exposición a materiales dentales, medicamentos y/o alimentos fueron problemas gastrointestinales, cutáneos y respiratorios.

First Record Of The Order Mecoptera (Insecta) For The Gorgona Island (Colombia), With The Description Of A New Species.

During a review of material from the project "Assessment of the current status of the faunistic conservation objects from the Gorgona Island: a holistic approach to the ecological evaluation of the Gorgona Natural National Park", conducted 2010‒2011, a male specimen of Pazius Navás, 1913 (Mecoptera: Bittacidae) was found. The genus had been previously recorded in Colombia in the Amazonas and Cundinamarca departments. The specimen described here differs from other species of Pazius by the absence of the aedeagus ventral process, the presence of seven short dorsal spines at the epandrium and shape of the ventral process. This finding represents the first record of the order Mecoptera for Gorgona Island, a new species of Pazius, and the expansion of the genus distribution in Colombia. A detailed morphological description of Pazius gorgonensis n. sp. and an identification key for species of the genus are presented.

Avispas de la vegetación arbórea en el Parque Nacional Natural Gorgona, Pacífico de Colombia / Wasps of the arboreal vegetation in the Gorgona National Natural Park, Pacific of Colombia

Wasps from the arboreal vegetation in Gorgona National Natural Park, Colombian Pacific. Studies of Colombian Hymenoptera are incipient, fragmented and there is no comprehensive study about its size and composition. We know that the guild of hymenopteran parasitoids is the richest in species and that they are common and abundant in all terrestrial ecosystems, acting as regulators of populations of other insects. Studies in Gorgona National Natural Park have mostly focused on the natural history and identification of Formicidae and Apidae. This work was directed toward the identification of other hymenopteran species associated with its tropical rain forest. In November 2007, 16 trees were sampled by fogging with a biodegradable pyrethroid insecticide applied from 1m above the ground to the canopy. We found 641 individuals (45% identified to subfamily and 28% to genera) from seven superfamilies, 20 families and 118 morphospecies. Chalcidoidea was the most representative superfamily, Eulophidae the most diverse family and Braconidae the numerically dominant family. The sampling efficiency was 71% and 166 species are estimated to exist in the island. Approximately 71% of the estimated species were captured during this study. We report 12 genera new for the island. Rev. Biol. Trop. 62 (Suppl. 1): 307-315. Epub 2014 February 01.

A pesar de la reconocida riqueza de Colombia, los estudios de la fauna de himenópteros son muy incipientes, fragmentarios y no hay revisiones de base que muestren el tamaño y composición de la fauna del país. Los himenópteros parasitoides son muy comunes y abundantes en todos los ecosistemas terrestres, actuando como reguladores de poblaciones de otros insectos. Este trabajo fue dirigido hacia la identificación de especies asociadas al dosel del bosque húmedo tropical del Parque Nacional Natural Gorgona, ecosistema insular ubicado en la parte sur del Pacífico colombiano, con el propósito de ampliar el conocimiento sobre este orden. En noviembre de 2007, se muestrearon 16 árboles mediante la técnica de nebulización, utilizando un insecticida piretroide biodegradable aplicado desde 1m sobre el nivel del suelo hasta el dosel. Se examinaron 641 individuos (identificados 45% a subfamilias y 28% a género) pertenecientes a siete superfamilias, 20 familias y 118 morfoespecies, siendo Chalcidoidea la superfamilia más representativa, Eulophidae la familia más diversa y Braconidae la familia dominante con el mayor número de ejemplares colectados. Se reportan 12 géneros nuevos para la isla, ampliando su rango de distribución y posicionando este estudio como el primero enfocado en este gremio de Hymenoptera en el parque.

Especies de hormigas del suelo en el Parque Nacional Natural Gorgona, Pacífico Colombiano / Soil ant species in Gorgona Island, Colombian Pacific

Soil ant species in Gorgona Island, Colombian Pacific. Gorgona is one of the two insular areas of the Colombian tropical rain forest at the Pacific and is amongst the most diverse biogeographic regions of the world, the Choco. This study compiles information on ant species from published (1991) and unpublished (2006) studies and provides new records for ant species collected in 2010. Ants were sampled and information was obtained from 15 sites in Gorgona island (13.82km²), including the Gorgonilla atoll (0.49km²). Collecting methods included pitfall traps, tuna baits, mini-Winkler extraction of leaf litter, Malaise traps, entomological net and direct search. The soil and understory ant inventory resulted in 107 ant species and morphospecies, 46 genera in 12 subfamilies. Myrmicinae held the highest species richness (37 species), followed by Ponerinae (27) and Formicinae (12). The richest genera were Pachycondyla (15 species), Camponotus (nine) and Pheidole (eight), while 30 genera were represented by a single species. Twelve species were very common (both in distribution and time): Azteca sp., Atta cephalotes, Camponotus sericeiventris, Eciton vagans, Ectatomma goninion, Gnamptogenys annulata, Odontomachus bauri, Pachycondyla bugabensis, P. harpax, P. verenae, Paraponera clavata and Wasmannia auropunctata. Direct search was the most efficient method to collect diferent species and was responsible for 52% of the total species found. Compared to other Neotropical islands, Gorgona holds a suprisingly high number of ant species, none of them invasive. The invasive Monomorium floricola, which was collected 20 years ago, was not found in 2010. These evidences suggest that ecological mechanisms and natural recovery processes in the ecosystem have generated microhabitats allowing their coexistence. Rev. Biol. Trop. 62 (Suppl. 1): 265-276. Epub 2014 February 01.

Este trabajo compila registros publicados (1991) y no publicados (2006) sobre las especies de hormigas del PNN Gorgona y aporta nuevos registros de especies recolectadas en 2010. Se recopiló información de 15 diferentes sitios de isla Gorgona (13.82km²), incluyendo la pequeña isla de Gorgonilla (0.4899km²). Los métodos de recolecta incluyeron trampas de caída, cebos de atún, sacos Winkler, trampas Malaise, red entomológica y captura directa. El inventario de hormigas de suelo y sotobosque resultó en 107 especies y morfoespecies, 46 géneros y 12 subfamilias. Myrmicinae reunió la mayor riqueza (37 especies) seguida de Ponerinae (27) y Formicinae (12). Los géneros más ricos fueron Pachycondyla (15 especies), Camponotus (nueve) y Pheidole (ocho), mientras que 30 géneros solo presentaron una especie. Doce especies fueron muy comunes: Azteca sp., Atta cephalotes, Camponotus sericeiventris, Eciton vagans, Ectatomma goninion, Gnamptogenys annulata, Odontomachus bauri, Pachycondyla bugabensis, P. harpax, P. verenae, Paraponera clavata y Wasmannia auropunctata. En comparación con otras islas neotropicales, Gorgona tiene un número sorprendentemente elevado de especies de hormigas, ninguna de ellas invasivas. Por tanto, estos resultados sugieren que, mecanismos ecológicos y procesos de recuperación natural en el ecosistema han generado disponibilidad de microhábitats permitiendo la coexistencia una gran riqueza de especies.

Hormigas arbóreas del Parque Nacional Natural Gorgona (Pacífico de Colombia) / Arboreal ants of the Gorgona National Natural Park (Pacific of Colombia)

Arboreal ants of Gorgona National Park (Pacific of Colombia). Despite the strong microclimatic fluctuations, scarcity of nesting sites and unpredictable prey availability in open environments, ants are the dominant invertebrates in the tropical forest canopy. This study focused on the arboreal ants in Gorgona National Park, Colombia, a rainforest ecosystem (27ºC, 6 000mm average annual rainfall). In November 2007, 16 trees were sampled by fogging them with a biodegradable pyrethroid insecticide in four levels between 1 and 15 m above the understory vegetation. We found 53 species of Formicidae (24 genera and six subfamilies): two subfamilies had the most species: Formicinae (20 species) and Myrmicinae (17). The most abundant were arboreal species of Azteca, Dolichoderus (D. bispinosus and D. lutosus), Camponotus (C. atriceps, C. claviscapus, C. championi, C. excisus) and Crematogaster (C. brasiliensis, C. carinata, C. curvispinosa). Some species that are common at ground level (Wasmannia auropunctata and Camponotus sericeiventris) were collected up to a height of 15 m. We remark the capture of Nesomyrmex pittieri, Crematogaster stolli, Cephalotes basalis, Anochetus bispinosus and Stigmatomma mystriops, species rarely found using conventional methods. Rev. Biol. Trop. 62 (Suppl. 1): 277-287. Epub 2014 February 01.

Este trabajo se enfocó en el conocimiento de la mirmecofauna arbórea de Gorgona, ecosistema insular de la zona de vida de bosque lluvioso tropical (27ºC, 6 000mm de precipitación promedio anual). En noviembre de 2007 se muestrearon 16 árboles mediante la técnica de nebulización usando un insecticida piretroide biodegradable, aplicado en dirección al dosel, desde cuatro alturas diferentes, entre 1 y 15m por encima de la vegetación del sotobosque. Se encontraron 53 especies de Formicidae pertenecientes a 24 géneros y seis subfamilias, sobresaliendo por su riqueza las Formicinae (20 especies) y Myrmicinae (17). Por su abundancia, se destacaron especies arbóreas de los géneros Azteca, Dolichoderus (D. bispinosus y D. lutosus), Camponotus (C. atriceps, C. claviscapus, C. championi, C. excisus) y Crematogaster (C. brasiliensis, C. carinata, C. curvispinosa). Algunas especies que son muy comunes a nivel del suelo (Wasmannia auropunctata y Camponotus sericeiventris), fueron colectadas a más de 15m de altura. Se resalta la captura de Nesomyrmex pittieri, Crematogaster stolli, Cephalotes basalis, Anochetus bispinosus y Stigmatomma mystriops que usualmente no se detectan en muestreos comunes.

Hormigas cazadoras en sistemas productivos del piedemonte amazónico colombiano: diversidad y especies indicadoras / Hunter ants in productive systems of Colombian amazon foothills: diversity and indicator species

Para conocer la abundancia, riqueza y composición de hormigas cazadoras y su variación en los sistemas productivos del departamento de Caquetá, se seleccionaron 27 fincas representativas de tres ventanas (agroforestal, silvopastoril y tradicional), en las cuales se identificaron hasta nueve clases de usos del suelo. Las proporciones dedicadas a pastos limpios, agroforestales y rastrojos viejos, fueron las que más contribuyeron a diferenciar las ventanas. Se muestrearon cinco puntos por finca mediante cuatro métodos para captura de hormigas (TSBF, lavado de suelo con formol, escrutinio de hojarasca y búsqueda directa). De un total de 280 individuos se determinaron nueve géneros y 35 especies de las subfamilias Ectatomminae, Paraponerinae y Ponerinae; el género más diverso fue Pachycondyla con 13 especies. La abundancia de hormigas se correlacionó directamente con la riqueza de especies y con el número de especies exclusivas. La riqueza fue mayor en la ventana agroforestal (24 especies), seguida de la silvopastoril (19) y de la tradicional (8). Cinco especies fueron comunes a las tres ventanas y siete especies (Ectatomma ruidum, Hypoponera sp.1 y sp.4, Odontomachus haematodus, O. brunneus y Pachycondyla constricta) marcaron las diferencias en composición. Odontomachus brunneus resultó indicadora para la ventana tradicional y Paraponera clavata para la ventana silvopastoril. La búsqueda directa fue el método más eficiente para muestrear hormigas cazadoras en el piedemonte amazónico.

We studied the abundance, richness and composition of hunting ants and their variation in production systems in department of Caquetá-Colombia, 27 farms were selected in three productive systems (agroforestry, silvopastoral and traditional), in this nine kinds of soil uses were identified. The proportions of clean pasture, agroforestry and old stubble contributed most to differentiating the systems. Five points were sampled per farm using four different methods for sampling ants (TSBF, formalin soil washing, screening of litter and direct search). A total of 280 organisms was collected, corresponding to nine genera and 35 species, belonging to the subfamilies Ectatomminae, Paraponerinae and Ponerinae. Pachycondyla was the most diverse genus (13 species). The abundance of ants was directly correlated with species richness and the number of exclusive species. The highest richness was observed in the agroforestry (24 species), followed by silvopastoral (19) and the lowest in traditional (8). Five species were common in the three systems and seven species marked the most differences in composition between systems (this was: Ectatomma ruidum, Hypoponera sp.1 and sp.4, Odontomachus haematodus, O. brunneus and Pachycondyla constricta). The species Odontomachus brunneus was indicator for the traditional system and Paraponera clavata was in silvopastoral system. Direct search was the most efficient method to sample ants in the Colombian Amazon foothills.

Proteínas morfogenéticas de hueso en oseointegración: revisión sistemática de literatura / Bone morphogenetic proteins in osseointegration: a systematic review of the literature

Las proteínas morfogenéticas de hueso están en la última etapa de reconocimiento por la Food and Drug Administration de los Estados Unidos. Los alcances de esta nueva tecnología prometen innovar nuestros procedimientos en regeneración de tejidos, especialmente en oseointegración. Es importante para el odontólogo conocer los avances que se han obtenido hasta el momento y las posibilidades clínicas. Se presenta una revisión sistemática de literatura con tal fin

Distribución espacial y temporal en un gradiente de sucesión de la fauna de coleópteros coprófagos (Scarabaeinae, Aphodiinae) en un bosque tropical montano, Nariño--Colombia / Space and time distribution along a succesional gradient of coprofagous coleopterans (Scarabaeinae, Aphodiinae) fauna in a tropical mountain forest, Nariño, Colombia

Se realizó un monitoreo a lo largo de 1993 en tres tipos de hábitat en la zona de influencia de la Reserva Natural la Planada (Nariño - Colombia): bosque primario, bosque secundario y pastizal. Se capturó 9 115 individuos pertenecientes a 18 especies y a 11 géneros. Se capturó un mayor número de especies (F 2, 9 = 29.88; P < 0.001) e individuos (F 2, 9 = 36.22; P < 0.001) en bosque primario que en bosque secundario y pastizal. Igualmente, se encontraron diferencias en la riqueza y la abundancia de las especies entre sitios de muestreo en el interior de cada hábitat. Los análisis de agrupamiento muestran que la composición de especies varía entre los hábitats con cobertura boscosas y zonas abiertas. En el bosque primario y en el bosque secundario, la proporción de individuos de hábitos cavadores y rodadores fueron similares, con el predominio de especies de actividad nocturna, mientras que en pastizal, desaparecieron los rodadores y se incrementaron las especies con actividad diurna. No se encontró una relación entre la precipitación y la riqueza de especies (r2 = 0.26; P = 0.41), ni entre la precipitación y el número de individuos capturados a lo largo del año (r2 = 0.07; P = 0.84). Todas las especies disminuyen su abundancia durante el período más seco del año y el inicio de las lluvias.

Transmigración contralateral de canino mandibular: reporte de caso clínico / Contralateral transmigration of mandibular canine: a case report

La transmigración de canino es una situación inusual que se manifiesta principalmente en mandíbula y consiste en el desplazamiento del diente a través de la línea media. En este artículo se presenta el cado de un canino izquierdo que sufre transmigración hasta el nivel de las raíces del segundo molar inferior derecho, ubicado cerca del borde inferior del cuerpo mandibular. Se enfatiza la necesidad de anestesiar el nervio alveolar inferior contralateral, puesto que el diente mantiene la inervación del sitio de desarrollo.