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1.
Integr Org Biol ; 6(1): obae014, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38741667

RESUMEN

The hyoid apparatus of tetrapods is highly diverse in its morphology. It plays an important role in feeding, breathing, sound production, and various other behaviors. Among turtles, the diversity of the hyoid apparatus has been recurrently linked to their habitat. The ossification of the hyoid corpus is often the main trait used in correlations with "niche" occupancy, an ossified corpus being associated with aquatic environments and a cartilaginous corpus with terrestrial life. Most studies conducted so far have focused on species belonging to Testudinoidea, the clade that occupies the biggest diversity of habitats (i.e., terrestrial, semi-terrestrial, and aquatic animals), while other turtle lineages have been largely understudied. We assessed the adult anatomy of the hyoid apparatus of 92 turtle species from all "families", together with ossification sequences from embryological series of 11 species, some described for the first time here. Using nearly 40 different discrete anatomical characters, we discuss the evolutionary patterns and the biological significance of morphological transformations in the turtle hyoid elements. Morphological changes are strongly associated to feeding modes, with several instances of convergent evolution within and outside the Testudines clade, and are not as strongly connected to habitat as previously thought. Some of the hyoid character states we describe are diagnostic of specific turtle clades, thus providing phylogenetically relevant information.


El aparato hyoideo de los tetrápodos es muy diverso en su morfología. El mismo desempeña un papel importante en la alimentación, la respiración, la producción de sonidos y otras funciones. En las tortugas, la diversidad del aparato hyoideo se ha relacionado con el hábitat. La osificación del cuerpo hyoideo es a menudo el rasgo principal utilizado en correlaciones con la ocupación de "nichos"; un cuerpo osificado se asocia con ambientes acuáticos y un cuerpo cartilaginoso con la vida terrestre. La mayoría de los estudios realizados se han centrado en especies pertenecientes a Testudinoidea, el clado que ocupa la mayor diversidad de hábitats (terrestre, semiterrestre y acuático), mientras que otros linajes de tortugas han sido poco estudiados. Evaluamos la anatomía adulta del aparato hyoideo de 92 especies de tortugas de todas las "familias", junto con secuencias de osificación de series embriológicas de once especies, algunas descritas por primera vez aquí. Utilizando casi 40 caracteres anatómicos discretos diferentes, discutimos los patrones evolutivos y el significado biológico de lastransformaciones morfológicas en los elementos hyoideos de las tortugas. Los cambios morfológicos están asociados con los modos de alimentación, con varios casos de convergencia dentro y fuera del clado Testudines; la asociación con el hábitat no es tan robusta como se ha hipotetizado. Algunos de los estados de caracteres que describimos son diagnósticos de clados de tortugas específicos, proporcionando así información filogenéticamente relevante.

2.
Sci Rep ; 14(1): 917, 2024 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-38195639

RESUMEN

Domestic goats (Capra hircus) are globally represented by over 300 breeds, making them a useful model for investigating patterns of morphological change related to domestication. However, they have been little studied, likely due to their poor representation in museum collections and the difficulty in obtaining truly wild goat (Capra aegagrus, the bezoar) samples. Similar studies on other species reveal that domestication correlates with craniofacial alterations in domestics, which are non-uniform and often species-specific. Here, we use three-dimensional geometric morphometric methods (3DGMM) to describe and quantify cranial shape variation in wild (n = 21) versus domestic (n = 54) goats. We find that mean cranial shapes differ significantly between wild and domestic goats as well as between certain breeds. The detected differences are lower in magnitude than those reported for other domestic groups, possibly explained by the fewer directions of artificial selection in goat breeding, and their low global genetic diversity compared to other livestock. We also find tooth-row length reduction in the domestics, suggestive of rostral shortening-a prediction of the "domestication syndrome" (DS). The goat model thus expands the array-and combinations of-morphological changes observed under domestication, notably detecting alterations to the calvarium form which could be related to the ~ 15% brain size reduction previously reported for domestic compared to wild goats. The global success of domestic goats is due more to their ability to survive in a variety of harsh environments than to systematized human management. Nonetheless, their domestication has resulted in a clear disruption from the wild cranial form, suggesting that even low-intensity selection can lead to significant morphological changes under domestication.


Asunto(s)
Cabras , Cráneo , Humanos , Animales , Cabras/genética , Domesticación , Luz , Ganado
3.
J Exp Zool B Mol Dev Evol ; 338(8): 460-483, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-34813150

RESUMEN

Comparisons of wild and domestic populations have established brain reduction as one of the most consistent patterns correlated with domestication. Over a century of scholarly work has been devoted to this subject, and yet, new data continue to foster its debate. Current arguments, both for and against the validity of brain reduction occurring in domestic taxa, have repeatedly cited a small set of reviews on this subject. The original works, their sampling, methodological details, and nuances of results that would be key to establishing validity, particularly in light of new data, have not been investigated. To facilitate and encourage a more informed discussion, we present a comprehensive review of original brain reduction literature for four mammalian clades: Artiodactyla, Perissodactyla, Carnivora, and Glires. Among these are studies that generated the most cited brain reduction values in modern domestication literature. In doing so, we provide a fairer stage for the critique of traits associated with domestication. We conclude that while brain reduction magnitudes may contain error, empirical data collectively support the reduction in brain size and cranial capacity for domestic forms.


Asunto(s)
Carnívoros , Domesticación , Animales , Encéfalo , Cráneo , Fenotipo
4.
Integr Org Biol ; 3(1): obab023, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34409262

RESUMEN

"Brachycephaly" is generally considered a phenotype in which the facial part of the head is pronouncedly shortened. While brachycephaly is characteristic for some domestic varieties and breeds (e.g., Bulldog, Persian cat, Niata cattle, Anglo-Nubian goat, Middle White pig), this phenotype can also be considered pathological. Despite the superficially similar appearance of "brachycephaly" in such varieties and breeds, closer examination reveals that "brachycephaly" includes a variety of different cranial modifications with likely different genetic and developmental underpinnings and related with specific breed histories. We review the various definitions and characteristics associated with brachycephaly in different domesticated species. We discern different types of brachycephaly ("bulldog-type," "katantognathic," and "allometric" brachycephaly) and discuss morphological conditions related to brachycephaly, including diseases (e.g., brachycephalic airway obstructive syndrome). Further, we examine the complex underlying genetic and developmental processes and the culturally and developmentally related reasons why brachycephalic varieties may or may not be prevalent in certain domesticated species. Knowledge on patterns and mechanisms associated with brachycephaly is relevant for domestication research, veterinary and human medicine, as well as evolutionary biology, and highlights the profound influence of artificial selection by humans on animal morphology, evolution, and welfare.


La braquicefalia generalmente se considera un fenotipo en el que el cráneo, específicamente el hocico, es notablemente acortado. Mientras que la braquicefalia es característica de algunas variedades domésticas y razas (p.e. Bulldog, gato persa, vaca ñata, cabra anglo nubiana, cerdo Middle White), también se puede interpretar como un fenotipo patológico. A pesar de que la braquicefalia tiene una apariencia semejante, por lo menos superficial, en estas variedades y razas, al examinarla más en detalle se descubre que la "braquicefalia" incluye una variedad de diferentes modificaciones del cráneo que probablemente tienen diferentes subyacentes genéticos y de desarrollo y que están relacionados con la historia de la raza. Revisamos las diferentes definiciones y propiedades relacionadas con la braquicefalia en varias especies domésticas. Describimos diferentes tipos de braquicefalia (tipo bulldog, "katantognático" y braquicefalia alométrica) y analizamos condiciones morfológicas relacionadas con la braquicefalia incluyendo enfermedades (p.e. síndrome obstructivo respiratorio). Además, examinamos los complejos procesos genéticos y de desarrollo subyacentes y los motivos culturales y de desarrollo por las que variedades braquicéfalas pueden ser más o menos prevalentes en ciertas especies domésticas. El conocimiento de patrones y mecanismos asociados a la braquicefalia son relevantes para la investigación sobre la domesticación, medicina veterinaria y humana, así como para la biología evolutiva y destaca la profunda influencia de la selección artificial sobre la morfología y bienestar de los animales y su evolución.

5.
Proc Biol Sci ; 288(1952): 20210813, 2021 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-34102890

RESUMEN

Cattle are one of the most intensively bred domestic animals, providing humans with a multitude of products and uses. Using data from the fossil record, we test if their domestication, as for other taxa, has resulted in a reduction of their brain size. We not only conclude that Bos taurus (domestic cattle) have smaller brains than their wild ancestor, Bos primigenius (aurochs), but that brain size varies significantly by breed, with some having much smaller brains than others. Differences in husbandry practices between several breed categories align with a range of human engagement, which also aligns with the degree of selection for docility. Sampling 317 domestics from 71 breeds, we investigate if differences in brain size correlate with the intensity of human contact. A clear pattern emerges whereby a brain reduction gradient parallels a gradient in behavioural selection. Bullfighting cattle, which are bred for fighting and aggressive temperament, have much larger brains than dairy breeds, which are intensively selected for docility. Our results add to a fundamental aspect of animal domestication theory: the interplay between basic features of the domestic environment-selection for docility, absence of predators and human provision of resources-seems to explain differences in brain size.


Asunto(s)
Animales Domésticos , Cruzamiento , Animales , Bovinos , Fósiles , Humanos , Tamaño de los Órganos , Filogenia
6.
Sci Adv ; 6(7): eaay4593, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32095528

RESUMEN

Despite being among the largest turtles that ever lived, the biology and systematics of Stupendemys geographicus remain largely unknown because of scant, fragmentary finds. We describe exceptional specimens and new localities of S. geographicus from the Miocene of Venezuela and Colombia. We document the largest shell reported for any extant or extinct turtle, with a carapace length of 2.40 m and estimated mass of 1.145 kg, almost 100 times the size of its closest living relative, the Amazon river turtle Peltocephalus dumerilianus, and twice that of the largest extant turtle, the marine leatherback Dermochelys coriacea. The new specimens greatly increase knowledge of the biology and evolution of this iconic species. Our findings suggest the existence of a single giant turtle species across the northern Neotropics, but with two shell morphotypes, suggestive of sexual dimorphism. Bite marks and punctured bones indicate interactions with large caimans that also inhabited the northern Neotropics.


Asunto(s)
Evolución Biológica , Extinción Biológica , Paleontología , Tortugas/anatomía & histología , Exoesqueleto/anatomía & histología , Animales , Tamaño Corporal , Peso Corporal , Huesos/anatomía & histología , Clima , Dieta , Femenino , Geografía , Fenómenos Geológicos , Masculino , Filogenia , Factores de Tiempo , Venezuela
8.
Rev. argent. dermatol ; 99(2): 1-10, jun. 2018. ilus
Artículo en Español | LILACS | ID: biblio-957916

RESUMEN

Neisseria meningitidis es la etiología de infecciones severas incluso letales, afectando principalmente a la población joven. No obstante, dado que el único reservorio es la nasofaringe humana, hay portadores asintomáticos. El meningococo es sensible a los antibióticos de uso habitual, como: cefalosporinas de tercera generación y quinolonas, pero el retraso en el diagnóstico por presentaciones clínicas infrecuentes y la administración tardía de la terapia, se asocian a elevada morbimortalidad. Presentamos una paciente de 18 años, con un cuadro de rápida evolución, con parámetros inflamatorios de laboratorio alterados, asociado a lesiones cutáneas purpúricas, que evolucionó con falla multiorgánica y desenlace fatal, lográndose la confirmación etiológica por el Instituto de Salud Pública. Reportamos el caso para tener en consideración el diagnóstico de meningococcemia, frente a pacientes con cuadro clínico y exámenes de laboratorio sugerentes de sepsis, que presentan lesiones cutáneas compatibles.


Neisseria meningitidis is the etiology of severe, even lethal infections, affecting mainly the young population. However, since the only reservoir is the human nasopharynx, there are asymptomatic carriers. Meningococcus is sensitive to commonly used antibiotics such as third generation cephalosporins and quinolones, but delayed diagnosis due to infrequent clinical presentation and delayed therapy are associated with high morbidity and mortality. We present an 18-year-old female patient with a rapid evolution, with altered inflammatory laboratory parameters, associated with purpuric skin lesions, which evolved with multiorgan failure and fatal outcome, and the etiological confirmation was obtained by the Public Health Institute. We report the case to take into account the diagnosis of meningococcemia in patients with clinical symptoms and laboratory tests suggestive of sepsis and compatible skin lesions.

10.
J Evol Biol ; 27(1): 98-115, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24251599

RESUMEN

Mammals display a broad spectrum of limb specializations coupled with different locomotor strategies and habitat occupation. This anatomical diversity reflects different patterns of development and growth, including the timing of epiphyseal growth plate closure in the long bones of the skeleton. We investigated the sequence of union in 15 growth plates in the limbs of about 400 specimens, representing 58 mammalian species: 34 placentals, 23 marsupials and one monotreme. We found a common general pattern of growth plate closure sequence, but one that is universal neither between species nor in higher-order taxa. Locomotor habitat has no detectable correlation with the growth plate closure sequence, but observed patterns indicate that growth plate closure sequence is determined more strongly through phylogenetic factors. For example, the girdle elements (acetabulum and coracoid process) always ossify first in marsupials, whereas the distal humerus is fused before the girdle elements in some placentals. We also found that heterochronic shifts (changes in timing) in the growth plate closure sequence of marsupials occur with a higher rate than in placentals. This presents a contrast with the more limited variation in timing and morphospace occupation typical for marsupial development. Moreover, unlike placentals, marsupials maintain many epiphyses separated throughout life. However, as complete union of all epiphyseal growth plates is recorded in monotremes, the marsupial condition might represent the derived state.


Asunto(s)
Placa de Crecimiento/crecimiento & desarrollo , Mamíferos/crecimiento & desarrollo , Animales , Extremidades/crecimiento & desarrollo , Locomoción
11.
Nat Commun ; 4: 1907, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23695701

RESUMEN

Northern South America and South East Asia are today's hotspots of crocodylian diversity with up to six (mainly alligatorid) and four (mainly crocodylid) living species respectively, of which usually no more than two or three occur sympatrically. In contrast, during the late Miocene, 14 species existed in South America. Here we show a diversity peak in sympatric occurrence of at least seven species, based on detailed stratigraphic sequence sampling and correlation, involving four geological formations from the middle Miocene to the Pliocene, and on the discovery of two new species and a new occurrence. This degree of crocodylian sympatry is unique in the world and shows that at least several members of Alligatoroidea and Gavialoidea coexisted. By the Pliocene, all these species became extinct, and their extinction was probably related to hydrographic changes linked to the Andean uplift. The extant fauna is first recorded with the oldest Crocodylus species from South America.


Asunto(s)
Caimanes y Cocodrilos/anatomía & histología , Biodiversidad , Extinción Biológica , Geografía , Animales , Fósiles , Fenómenos Geológicos , Filogenia , Factores de Tiempo
12.
Diabet Med ; 30(9): 1102-11, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23668772

RESUMEN

AIM: To evaluate the effect of system interventions (formalized data collection and 100% coverage of medications and supplies) combined with physician and/or patient education on therapeutic indicators and costs in Type 2 diabetes. METHODS: This was a randomized 2 × 2 design in public health, social security or private prepaid primary care clinics in Corrientes, Argentina. Thirty-six general practitioners and 468 adults with Type 2 diabetes participated. Patients of nine participating physicians were selected randomly and assigned to one of four structured group education programmes (117 patients each): control (group 1), physician education (group 2), patient education (group 3), and both physician education and patient education (group 4), with identical system interventions in all four groups. Outcome measures included HbA(1c), BMI, blood pressure, fasting glucose, lipid profile, drug consumption, resource use and patient well-being at baseline and every 6 months up to 42 months. RESULTS: HbA(1c) decreased significantly from 4 mmol/mol to 10 mmol/mol by 42 months (P < 0.05); the largest and more consistent decrease was in the groups where patients and physicians were educated. Blood pressure and triglycerides decreased significantly in all groups; the largest changes were recorded in the combined education group. The World Health Organization-5 Lowe score showed significant improvements, without differences among groups. The lowest treatment cost was seen in the combined education group. CONCLUSIONS: In a primary care setting, educational interventions combined with comprehensive care coverage resulted in long-term improvement in clinical, metabolic and psychological outcomes at the best cost-effectiveness ratio.


Asunto(s)
Complicaciones de la Diabetes/prevención & control , Diabetes Mellitus Tipo 2/terapia , Educación Médica Continua , Costos de la Atención en Salud , Hiperglucemia/prevención & control , Educación del Paciente como Asunto , Atención Primaria de Salud , Anciano , Argentina , Costos y Análisis de Costo , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/economía , Educación Médica Continua/economía , Femenino , Estudios de Seguimiento , Médicos Generales/educación , Hemoglobina Glucada/análisis , Promoción de la Salud/economía , Humanos , Hiperlipidemias/complicaciones , Hiperlipidemias/prevención & control , Hipertensión/complicaciones , Hipertensión/prevención & control , Masculino , Persona de Mediana Edad , Pacientes Desistentes del Tratamiento , Educación del Paciente como Asunto/economía , Atención Primaria de Salud/economía
13.
J Evol Biol ; 25(5): 862-72, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22356604

RESUMEN

Studies of morphological integration can provide insight into developmental patterns, even in extinct taxa known only from skeletal remains, thus making them an important tool for studies of evolutionary development. However, interpreting patterns of integration and assessing their significance for organismal evolution requires detailed understanding of the developmental interactions that shape integration and how those interactions change through ontogeny. Thus far, relatively little comparative data have been produced for this important topic, and the data that do exist are overwhelmingly from humans and their close relatives or from laboratory models such as mice. Here, we compare data on shape, variance and integration through postnatal ontogeny for a placental mammal, the least shrew, Cryptotis parva, and a marsupial mammal, the gray short-tailed opossum, Monodelphis domestica. Cranial variance decreased dramatically from early to late ontogeny in Cryptotis, but remained stable through ontogeny in Monodelphis, potentially reflecting functional constraints related to the short gestation and early ossification of oral bones in marsupials. Both Cryptotis and Monodelphis showed significant changes in cranial integration through ontogeny, with a mixture of increased, decreased and stable levels of integration in different cranial regions. Of particular note is that Monodelphis showed an unambiguous decrease in integration of the oral region through ontogeny, potentially relating to their early ossification. Selection at different stages of development may have markedly different effects if patterns of integration change substantially through ontogeny. Our results suggest that high integration of the oral region combined with functional constraints for suckling during early postnatal ontogeny may drive the stagnant variance observed in Monodelphis and potentially other marsupials.


Asunto(s)
Monodelphis/embriología , Osteogénesis , Musarañas/embriología , Cráneo/embriología , Animales , Evolución Biológica , Femenino , Monodelphis/crecimiento & desarrollo , Monodelphis/fisiología , Morfogénesis , Embarazo , Análisis de Componente Principal , Musarañas/crecimiento & desarrollo , Musarañas/fisiología , Cráneo/crecimiento & desarrollo , Cráneo/fisiología , Especificidad de la Especie , Coloración y Etiquetado , Factores de Tiempo
14.
J Exp Zool B Mol Dev Evol ; 312B(3): 186-95, 2009 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-19205003

RESUMEN

The contrasting evolutionary histories of marsupial and placental mammals have often been attributed to their different reproductive strategies. The speciose placentals develop mainly in utero and have radiated into diverse niches, whereas marsupials are born in a highly altricial state with immediate functional requirements and are limited in taxonomic, ecological, and morphological diversity. These differences have been tied to heterochrony, and it has been hypothesized that coordinated shifts in developmental timing occur among functionally- or developmentally related structures, such as forelimbs in marsupials. We use new ossification sequence data for 11 marsupial and 14 placental species to assess the integration of first ossification timing among skeletal elements. Although cranial elements fail to demonstrate significant coordination, marsupials and placentals differ markedly in postcranial integration. Marsupials display independent anterior and posterior developmental modules, whereas placentals show significant integration of the entire appendicular skeleton. This developmental integration of the placental postcranium is consistent with a recent study of phenotypic modularity in limbs of placental mammals, showing a potential correspondence between integration of developmental timing and of shape. The observed differences in postcranial integration between marsupials and placentals may reflect the disparate evolutionary histories of these two mammalian clades.


Asunto(s)
Huesos/fisiología , Marsupiales/fisiología , Placenta/fisiología , Reproducción/fisiología , Animales , Animales Recién Nacidos , Evolución Biológica , Femenino , Muridae/fisiología , Osteogénesis/fisiología , Filogenia , Especificidad de la Especie , Factores de Tiempo
15.
Contemp Clin Trials ; 28(4): 548-56, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17331807

RESUMEN

OBJECTIVE: To implement a controlled clinical trial (PRODIACOR) in a primary care setting designed 1) to improve type 2 diabetes care and 2) to collect cost data in order to be able to measure cost-effectiveness of three system interventions (checkbook of indicated procedures, patient/provider feedback and complete coverage of medications and supplies) and physician and/or patient education to improve psychological, clinical, metabolic and therapeutic indicators. All three Argentinean health subsectors (public health, social security and the private, prepaid system) are participants in the study. Patients of participating physicians were randomly selected and assigned to one of four groups: control, provider education, patient education, and provider/patient education; the system interventions were provided to all four groups. BASELINE RESULTS: Mean BMI was 29.8 kg/m(2); most subjects had blood pressure, fasting glucose and total cholesterol above targets recommended by international standards. Only 1% had had microalbuminuria measured, 57% performed glucose self-monitoring, 37% had had an eye examination and 31% a foot examination in the preceding year. Ten percent, 26% and 73% of people with hyperglycemia, hypertension and dyslipidemia, respectively, were not on medications. Most patients treated with either insulin or oral antidiabetic agents were on monotherapy as were those treated for hypertension and dyslipidemia. WHO-5 questionnaire scores indicated that 13% of the subjects needed psychological intervention. CONCLUSIONS: Baseline data show multiple deficiencies in the process and outcomes of care that could be targeted and improved by PRODIACOR intervention.


Asunto(s)
Enfermedades Cardiovasculares/terapia , Diabetes Mellitus Tipo 2/terapia , Atención Dirigida al Paciente , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Anciano , Argentina , Índice de Masa Corporal , Recolección de Datos/estadística & datos numéricos , Femenino , Indicadores de Salud , Humanos , Capacitación en Servicio , Masculino , Persona de Mediana Edad , Educación del Paciente como Asunto , Satisfacción del Paciente , Atención Primaria de Salud , Garantía de la Calidad de Atención de Salud , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Sistemas Recordatorios , Proyectos de Investigación , Factores de Riesgo , Tamaño de la Muestra
16.
Rev. méd. Chile ; 134(11): 1436-1442, nov. 2006. ilus
Artículo en Español | LILACS | ID: lil-439944

RESUMEN

Neurological abnormalities associated with spiculated, "acanthocytic" red cells in blood have been described as neuroacanthocytosis. This is a heterogeneous group of conditions that can be clearly subdivided on the basis of recent genetic findings. The McLeod Syndrome, one of the core neuroacanthocytosis syndromes, is a rare X-linked disorder caused by mutations of the XK gene, an X-chromosomal gene of unknown function characterized by haemopoietic abnormalities and late-onset neurological and muscular defects. We report two Chilean brothers with the McLeod phenotype who showed important psychiatric features. The diagnosis may be elusive if the presence of acanthocytosis is not properly studied. We describe a method which allowed the diagnosis that unmasked acanthocytosis. Otherwise the condition could have remained undiagnosed as it had been for decades in this family. This syndrome must be considered when assessing a familial movement disorder, specially affecting males with relevant psychiatric features. A reliable test for acanthocytosis assessment is available.


Asunto(s)
Humanos , Masculino , Persona de Mediana Edad , Sistemas de Transporte de Aminoácidos Neutros/genética , Antígenos de Superficie/genética , Proteínas Sanguíneas/genética , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Mutación/genética , Neuroacantocitosis/genética , Enfermedades Genéticas Ligadas al Cromosoma X/diagnóstico , Neuroacantocitosis/diagnóstico , Linaje , Síndrome
17.
Rev Med Chil ; 134(11): 1436-42, 2006 Nov.
Artículo en Español | MEDLINE | ID: mdl-17277857

RESUMEN

Neurological abnormalities associated with spiculated, "acanthocytic" red cells in blood have been described as neuroacanthocytosis. This is a heterogeneous group of conditions that can be clearly subdivided on the basis of recent genetic findings. The McLeod Syndrome, one of the core neuroacanthocytosis syndromes, is a rare X-linked disorder caused by mutations of the XK gene, an X-chromosomal gene of unknown function characterized by haemopoietic abnormalities and late-onset neurological and muscular defects. We report two Chilean brothers with the McLeod phenotype who showed important psychiatric features. The diagnosis may be elusive if the presence of acanthocytosis is not properly studied. We describe a method which allowed the diagnosis that unmasked acanthocytosis. Otherwise the condition could have remained undiagnosed as it had been for decades in this family. This syndrome must be considered when assessing a familial movement disorder, specially affecting males with relevant psychiatric features. A reliable test for acanthocytosis assessment is available.


Asunto(s)
Sistemas de Transporte de Aminoácidos Neutros/genética , Antígenos de Superficie/genética , Proteínas Sanguíneas/genética , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Mutación/genética , Neuroacantocitosis/genética , Enfermedades Genéticas Ligadas al Cromosoma X/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Neuroacantocitosis/diagnóstico , Linaje , Síndrome
18.
J Exp Zool B Mol Dev Evol ; 302(2): 134-46, 2004 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-15054857

RESUMEN

Documentation of variation in phalangeal formulae in land tortoises combined with ontogenetic information from turtles in general were used, in a phylogenetic context, to infer the potential effect of size and developmental constraints upon patterns of morphological variation. A sample of 201 specimens and published illustrations of 37 tortoise species were examined, representing all but one living genera and most species of the Testudinidae. Specimens were either articulated dry skeletons or preserved animals that were x-rayed. The patterns of digital and phalangeal loss in tortoises were predicted from developmental studies of the manus and pes in other turtles. If a digit is lost, it is the first digit, which is the last one to develop. If a digit has a single phalanx, it is usually the fifth digit. The primitive phalangeal formula for land tortoises is probably 2-2-2-2-1, the most common pattern found in living testudinid species. The presence of a second phalanx in the fifth digit evolved independently many times and usually in large tortoises. Such additions were interpreted as instances of peramorphosis. Many small tortoises have a full complement of digits (five) and phalanges (two in each digit); nevertheless, phalangeal and digital loss is associated with small size. Small and medium size tortoises exhibit greater variation in phalangeal number than do large tortoises. We hypothesize that epigenetic processes, and not simply adaptation, played a major role in the evolution of the variation in phalangeal formulae in tortoises.


Asunto(s)
Huesos/anatomía & histología , Extremidades/anatomía & histología , Filogenia , Tortugas/anatomía & histología , Animales , Pesos y Medidas Corporales , Epigénesis Genética/fisiología , Factores de Tiempo
19.
Rev. méd. Chile ; 127(8): 926-34, ago. 1999. tab, graf
Artículo en Español | LILACS | ID: lil-253159

RESUMEN

Background: Acinetobacter baumannii nosocomial outbreaks are common and the microorganism is frequently resistant to multiple antimicrobials. There is little information about Acinetobacter baumannii antimicrobial susceptibility in the northern region of Chile. Aim: To identify different Acinetobacter baumannii biotypes isolated from clinical samples and to determine their antimicrobial susceptibility. Material and methods: One hundred twenty three Acinetobacter baumannii isolates were studied. The identification and typing of Acinetobacter baumannii was based on phenotypic characteristics. Antimicrobial susceptibility was investigated using agar dilution techniques. Results: Most Acinetohacter baumannii strains were isolated from wounds, urinary and respiratory infections. Seven biotypes were isolated, being biotype 9 the most frequent. lmipenem was the antimicrobial with the higher activity against the microorganism. Amikacin, cefoperazonesulbactam, ampicillinsulbactam and ceftazidime had a moderate activity. There were high resistance levels to ampicillin and older cephalosporins. Conclusions: Acinetobacter baumannii is emerging as a significant nosocomial pathogen in Chile and shows high resistance rates to multiple antibiotics


Asunto(s)
Humanos , Acinetobacter/efectos de los fármacos , Farmacorresistencia Microbiana , Orina/microbiología , Acinetobacter/aislamiento & purificación , Infecciones por Acinetobacter/tratamiento farmacológico , Chile , Imipenem/farmacología , Hospitales Provinciales/estadística & datos numéricos
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