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1.
J Investig Med High Impact Case Rep ; 10: 23247096211056494, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35596563

RESUMO

Androgen-producing steroid cell ovarian tumors are rare, comprising less than 1% of ovarian neoplasms, and can present with infertility and rapid virilization. Here we discuss the case of a 28-year-old woman who presented with an unusually insidious 2-year history of infertility, hirsutism, and clitoromegaly who was found to have an elevated serum testosterone and a left ovarian mass. She underwent oophorectomy and pathology revealed a steroid cell tumor, not otherwise specified (NOS), with no malignant features. Following surgery, the patient's hyperandrogenic symptoms resolved with normalization of testosterone within 6 months, and she was able to conceive spontaneously. In reproductive-aged women with progressive hyperandrogenic symptoms, androgen-producing tumors, including those of ovarian origin, should be suspected. Thorough investigation, including plasma hormone levels and tumor histology, can lead to accurate diagnosis and management. Treatment should be guided by histology and surgical staging, with consideration for future fertility desires. Women who have not completed childbearing can undergo unilateral oophorectomy or tumor resection for benign tumors, with close monitoring of sex hormone levels postoperatively.


Assuntos
Infertilidade , Neoplasias Ovarianas , Tumores do Estroma Gonadal e dos Cordões Sexuais , Adulto , Androgênios , Feminino , Humanos , Neoplasias Ovarianas/complicações , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/cirurgia , Testosterona , Virilismo/etiologia
2.
J Anxiety Disord ; 79: 102384, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33774559

RESUMO

Contamination-based obsessive-compulsive disorder (OCD) is thought to develop and be maintained by excessive propensity to experience disgust, particularly in response to perceived contaminants, and dysfunctional threat appraisals pertaining to illness. The present studies attempted to integrate these lines of research by testing the degree to which contamination-based OCD is associated with individual differences in disgust propensity and sensitivity, affective distress in response to perceived contaminants, and perceived threat of illness. In Study 1, a convenience sample of 185 adults completed self-report scales assessing obsessive-compulsive symptoms, disgust propensity and sensitivity, germ aversion, and perceived infectability. Multivariate regression showed that disgust propensity and germ aversion were the only significant predictors of contamination-based obsessions and compulsions. Exploratory analyses suggested that there was a significant indirect effect of disgust propensity on contamination-based obsessions and compulsions via germ aversion. Findings from Study 1 were replicated using a sample of twenty-six obsessive-compulsive participants. Despite the substantially smaller sample, the proportion of the total effects attributable to the mediating effect of germ aversion was comparable, consistent with a significant partial mediation in both samples. These results together suggest that contamination-based OCD symptoms are likely maintained and motivated by basic affective processes.


Assuntos
Asco , Transtorno Obsessivo-Compulsivo , Adulto , Afeto , Comportamento Compulsivo , Emoções , Humanos
3.
Cancer Immunol Immunother ; 70(5): 1465-1474, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33180182

RESUMO

BACKGROUND: Colorectal cancer (CRC) tumor microenvironment (TME) characteristics, such as tumor infiltrating lymphocyte (TIL) densities and PD-L1 status, are predictive of recurrence, disease-free survival, and overall survival. In many malignancies, TME characteristics are also predictive of response to immunotherapy. As window of opportunity studies using neoadjuvant immunotherapy become more common and treatment guidelines incorporate TME features, accurate assessment of the pre-treatment TME using the biopsy specimen is critical. However, no study has thoroughly evaluated the correlation between the TMEs of the biopsy and resection specimens. METHODS: We conducted a retrospective analysis of patients with stage I-III CRC with matched biopsy and resection specimens. CD3+, CD4+, CD8+, and FoxP3+ lymphocyte populations at the center of tumor (CT) and invasive margin (IM) and tumor PD-L1 status in the biopsy and resection specimens were evaluated. TIL populations were compared using Mann-Whitney U tests or Student's t tests and correlated using Pearson r. RESULTS: CD3+ and CD4+ densities were significantly higher in the CT of the biopsy relative to the resection specimen Comparing biopsy and resection specimens, no TIL population at either the CT or IM had a correlation coefficient > 0.5. Determining PD-L1 status based on biopsy tissue resulted in a sensitivity of 37.1%, specificity of 81.4%, and accuracy of 61.5%. CONCLUSIONS: These findings demonstrate significant discordance between the TME of the biopsy and resection specimens. Caution should be used when basing treatment decisions on pre-treatment endoscopic biopsy findings and when interpreting changes in the TME between pre-treatment biopsy and resection specimens after neoadjuvant therapy.


Assuntos
Adenocarcinoma/diagnóstico , Biópsia/métodos , Linfócitos T CD4-Positivos/imunologia , Colo/patologia , Neoplasias Colorretais/diagnóstico , Linfócitos do Interstício Tumoral/imunologia , Idoso , Antígeno B7-H1/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Retrospectivos , Sensibilidade e Especificidade , Microambiente Tumoral
4.
Can Vet J ; 61(10): 1080-1084, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33012824

RESUMO

The effects of intravenous (IV) fluid warming on core body temperature in a group of dogs undergoing an elective orthopedic procedure was studied. An IV fluid warmer was used alone or in conjunction with forced warmed air to determine the individual or additive effects of IV fluid warming. These effects were compared to those in dogs with no heat support or those with only forced warmed air in a randomized prospective study design. The conclusion was that IV fluid warming had no effect on the maintenance or preservation of core body temperature in this population of dogs, and that, as previous reports have shown, forced warmed air decreased the rate of heat loss during anesthetic procedures. One possible explanation for the lack of benefit is the location of the fluid warmer in relation to the patient. To our knowledge, this is the first study to examine the effects of IV fluid warming on core body temperature in dogs undergoing an elective orthopedic procedure.


Effet du réchauffement du liquide intraveineux sur la température corporelle centrale durant des procédures orthopédiques électives. Les effets du réchauffement du liquide intraveineux (IV) sur la température corporelle centrale dans un groupe de chiens soumis à une procédure orthopédique élective fut étudiée. Un réchaud à fluide IV était utilisé seul ou conjointement avec de l'air chaud forcé afin de déterminer les effets individuels ou additifs du réchauffement du liquide IV. Ces effets furent comparés à ceux de chiens sans support de chaleur ou ceux avec uniquement de l'air chaud forcé dans une étude prospective randomisée. La conclusion était à l'effet que le réchauffement du liquide IV n'avait aucun effet sur le maintien ou la préservation de la température corporelle centrale dans cette population de chiens, et que, tel que démontré par des études antérieures, de l'air chaud forcé diminuait le taux de perte de chaleur durant les procédures anesthésiques. Une explication possible pour l'absence de bénéfice serait la localisation du chauffe liquide relativement au patient. À notre connaissance, ceci constitue la première étude à examiner les effets du réchauffement du liquide IV sur la température corporelle centrale chez des chiens soumis à une procédure orthopédique élective.(Traduit par Dr Serge Messier).


Assuntos
Hipotermia , Procedimentos Ortopédicos , Animais , Temperatura Corporal , Regulação da Temperatura Corporal , Cães , Hipotermia/veterinária , Procedimentos Ortopédicos/veterinária , Estudos Prospectivos
5.
Methods Mol Biol ; 2145: 215-230, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32542610

RESUMO

Tissue-engineered corneal constructs offer the potential of readily available corneal substitutes for transplantation. As with all medical devices and implants, these constructs require rigorous safety assessments, combined with well-described analyses of the implant's physical and biological characteristics. Although the constructs are developed in vitro, such studies are currently unable to fully emulate the complex biomechanical and biochemical conditions within living tissue, as well as the interplay between this environment and immunological factors. For these reasons, animal models remain essential to characterize such interactions. They form a stage where corneal implants can be tested for utility and survival in a living location to assess their ability to provide vision and avoid adverse event. Here, we examine the surgical considerations of animal models and we describe how the rabbit can be used for this purpose. This animal has been the routine model for ophthalmological studies and we set out methods to implant corneal constructs with this species.


Assuntos
Córnea/crescimento & desenvolvimento , Transplante de Córnea/métodos , Engenharia Tecidual/métodos , Animais , Córnea/patologia , Humanos , Modelos Animais , Próteses e Implantes , Coelhos
6.
Pediatr Dev Pathol ; 23(5): 352-355, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32340561

RESUMO

Granulomatous inflammation is a histologic finding with a relatively wide variety of causes. In general, considerations include infectious etiologies, autoimmune conditions, or foreign body reactions. Granulomatous inflammation is uncommonly seen in the placenta. We present a unique case of a young woman with preterm labor and rupture of membranes whose placenta demonstrated perivascular decidual granulomata in the membranes and the basal plate.


Assuntos
Ruptura Prematura de Membranas Fetais/etiologia , Granuloma/patologia , Doenças Placentárias/patologia , Placenta/patologia , Nascimento Prematuro/etiologia , Feminino , Granuloma/diagnóstico , Granuloma/fisiopatologia , Humanos , Placenta/fisiopatologia , Doenças Placentárias/diagnóstico , Doenças Placentárias/fisiopatologia , Gravidez , Adulto Jovem
7.
Rev. biol. trop ; 67(6)dic. 2019.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1507595

RESUMO

Dos especies de cocodrilianos han sido descritas en Costa Rica, el cocodrilo americano, Crocodylus acutus (Cuvier, 1807) y el caimán, Caiman crocodilus (Linnaeus, 1758). En Costa Rica se ha generado información de ambas especies, pero con énfasis en la vertiente del Pacífico, presumiblemente debido a su mayor desarrollo, lo cual ha acarreado mayor presión social hacia la atención de incidentes generados por el encuentro entre humanos y cocodrilos. El estudio se desarrolló durante el 2017 y en un área de aproximadamente 400 km2, caracterizada por tener una amplia densidad de cursos de agua que incluyen a los ríos: Matina, Pacuare, Reventazon y Parismina. En estos ríos se recorrió un promedio de 25 km desde la línea de costa hasta el interior del territorio, incluyendo los canales de Tortuguero, así como otros cuerpos de agua que conectan a estos ríos, lagunas importantes, y canales secundarios. Se realizaron tres repeticiones por segmento. Una población de 1 084 caimanes y 503 cocodrilos fue estimada, para una abundancia relativa de 8.64 y 2.80 ind/km respectivamente. Con respecto a caimanes poco más del 12 por ciento de los animales observados estaban en edad reproductiva, mientras que para cocodrilos sólo un 2 por ciento. La abundancia en los diferentes segmentos resultó ser significativamente diferente para ambas especies (Kruskal-Wallis, P 0.000). Mientras que la distribución por tallas de cocodrilos fue similar en todos los segmento (Kruskal-Wallis, P 0.15). Con 9 cocodrilos y 18 caimanes, reclutas o juveniles capturados, se calculó una proporción de sexos de 1.25 y 0.83 machos a hembras, para cocodrilos y caimanes respectivamente.


Two species of crocodilians have been described in Costa Rica, American crocodile, Crocodylus acutus (Cuvier, 1807), and caiman, Caiman crocodilus (Linnaeus 1758). In Costa Rica, data has been generated on both species, but populations in the Pacific have received more attention from researchers; presumably due to the fact that the Pacific slope has a greater development, which brings greater social pressure on the attention of the incidents generated by the encounter between humans and crocodiles. This study, performed during 2017, was done in an area of approximately 400 km2, characterized by having a wide and dense network of water courses, which includes the Matina, Pacuare, Reventazón and Parismina rivers. In these rivers, an average of 25 kilometers were traveled from the coastline up stream to the interior of the territory, including the Tortuguero canals, and other water bodies that connect these rivers, as well as in the most important lagoons and secondary channels. Three repetitions were made per segment. A population of 1 084 caimans and 503 crocodiles is estimated; for a sight count of 8.64 and 2.80 ind/Km respectively. Speaking of caimans, up to 12 por ciento of individuals of reproductive age were observed, while for crocodiles that number was only 2 por ciento. The abundance of both species in the different places studied, turned out to be significantly different for crocodiles and for caimans (Kruskal-Wallis, P 0.001). Likewise, the size distribution is similar for crocodiles reported in all environments (Kruskal-Wallis, p 0.15), while for caimans it indicates that there is a different distribution for sizes, according to the environment in which they are found (Kruskal -Wallis, P 0.001), with a bias against of the Pacuare and Matina rivers. It was possible to estimate a sex ratio of 1.25 and 0.83 males to females, in crocodiles and caimans respectively, with 9 and 11 captures in that same order, in recruit and juvenile sizes.

8.
Biomaterials ; 188: 63-73, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30321864

RESUMO

Biological scaffolds generated from tissue-derived extracellular matrix (ECM) are commonly used clinically for soft tissue regeneration. Such biomaterials can enhance tissue-specific differentiation of adult stem cells, suggesting that structuring different ECMs into multi-layered scaffolds can form the basis of new strategies for regenerating damaged interfacial tissues such as the osteochondral unit. In this study, mass spectrometry is used to demonstrate that growth plate (GP) and articular cartilage (AC) ECMs contain a unique array of regulatory proteins that may be particularly suited to bone and cartilage repair respectively. Applying a novel iterative freeze-drying method, porous bi-phasic scaffolds composed of GP ECM overlaid by AC ECM are fabricated, which are capable of spatially directing stem cell differentiation in vitro, promoting the development of graded tissues transitioning from calcified cartilage to hyaline-like cartilage. Evaluating repair 12-months post-implantation into critically-sized caprine osteochondral defects reveals that these scaffolds promote regeneration in a manner distinct to commercial control-scaffolds. The GP layer supports endochondral bone formation, while the AC layer stimulates the formation of an overlying layer of hyaline cartilage with a collagen fiber architecture better recapitulating the native tissue. These findings support the use of a bi-layered, tissue-specific ECM derived scaffolds for regenerating spatially complex musculoskeletal tissues.


Assuntos
Condrogênese , Matriz Extracelular/química , Células-Tronco Mesenquimais/citologia , Osteogênese , Alicerces Teciduais/química , Animais , Materiais Biocompatíveis/química , Cartilagem Articular/química , Diferenciação Celular , Células Cultivadas , Cabras , Lâmina de Crescimento/química , Regeneração , Suínos , Engenharia Tecidual/métodos
9.
J Low Genit Tract Dis ; 22(4): 274-279, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30256335

RESUMO

OBJECTIVE: The aim of the study was to determine beliefs and utilization of cervical cancer screening and prevalence of low-grade squamous intraepithelial lesion/high-grade squamous intraepithelial lesion among a university-based population in the Southwest region of Cameroon. MATERIALS AND METHODS: A public-private partnership was established between the University of Arizona, University of Buea, and the Cameroon Baptist Convention Health Services. A single-day screening clinic using visual inspection with acetic acid and Lugol's iodine solution (VILI) was provided at the University of Buea. Screening results were documented as negative, low-grade, high-grade, or suspicious for cancer. Thermocoagulation and loop electrosurgical excisional procedure was available for low- and high-grade lesions, respectively. A survey was conducted before screening and factors associated with screening practices were evaluated. RESULTS: Of 120 clinic participants, 107 (89.2%) believed that treatment of precancerous lesions helped prevent cervical cancer, but most (67.5%) had never been screened. Eighty women (66.7%) were aware of the human papillomavirus (HPV) vaccine, and only 2 had received vaccination. Among 115 patients screened, the prevalence of abnormal screening was 6.09%. Low-grade lesions were treated with thermocoagulation and high-grade lesions were treated with loop electrosurgical excisional procedure. CONCLUSIONS: Despite knowledge of cervical cancer screening benefits, the majority had not been screened or vaccinated. This study suggests a desire for additional screening services in this population and validates the utility of public-private partnerships in low-income regions.


Assuntos
Detecção Precoce de Câncer , Conhecimentos, Atitudes e Prática em Saúde , Mau Uso de Serviços de Saúde , Lesões Intraepiteliais Escamosas Cervicais/diagnóstico , Lesões Intraepiteliais Escamosas Cervicais/psicologia , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/prevenção & controle , Adulto , Idoso , Camarões , Feminino , Humanos , Pessoa de Meia-Idade , Inquéritos e Questionários , Universidades , Adulto Jovem
10.
Gynecol Oncol Rep ; 26: 17-20, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30148200

RESUMO

BACKGROUND: Sex cord tumors with annular tubules (SCTAT) are a rare (2%) subtype of ovarian sex cord-stromal tumor. SCTATs are usually cured at time of diagnosis by surgical resection with an oophorectomy. SCTATs have a 100%(disease related) five-year survival. One third of SCTAT tumors are associated with Peutz-Jeghers syndrome. Literature review discovered only two published cases of extra-ovarian SCTAT. Due to the rarity there is no standard treatment for extraovarian SCTATs. CASE: A 39-year-old para-1 female with a symptomatic fibroid uterus, heavy menstrual bleeding, and a history of a uterine myomectomy, underwent an elective total abdominal hysterectomy. Intraoperative findings showed a 7.5 cm retroperitoneal mass adhered between the uterus and the right pelvic sidewall that on frozen section was found to be a degenerating leiomyoma. Final pathology demonstrated a 2 mm focus of incidental SCTAT adjacent to the serosal surface of the leiomyoma. The SCTAT was not associated with ectopic ovarian tissue or endometriosis. The patient's ovaries were normal on direct intraoperative examination, preoperative ultrasound and MRI. Six month postoperative surveillance ultrasound also demonstrated normal premenopausal ovaries. CONCLUSION: This is the first extraovarian SCTAT in the published literature arising from a leiomyoma. Our patient had no family history and displayed no syndromic features for Peutz-Jeghers Syndrome. Ultimately, she declined genetic testing. The lack of evidence of ovarian involvement on both imaging and on intraoperative examination made localization to either ovary impossible. The patient is currently being managed with surveillance since the morbidity associated with bilateral oophorectomy in the 4th decade of life exceeds the theoretical risk of SCTAT.

11.
Case Rep Oncol Med ; 2018: 5683417, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29755802

RESUMO

We report the case of a 71-year-old male with relapsed acute myeloid leukemia who developed cytomegalovirus (CMV) colitis presenting as an apple-core lesion during induction chemotherapy. CMV infection occurs rarely during induction chemotherapy for acute myeloid leukemia. CMV infection is usually observed in patients with acquired immune deficiency syndrome (AIDS) and in those on immunosuppressive agents following bone marrow transplant. Although rare, CMV colitis should be considered in patients who are critically ill after systemic chemotherapy as it can cause significant morbidity and mortality.

12.
Radiographics ; 37(5): 1401-1407, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28898187

RESUMO

Editor's Note.-RadioGraphics continues to publish radiologic-pathologic case material selected from the American Institute for Radiologic Pathology (AIRP) "best case" presentations. The AIRP conducts a 4-week Radiologic Pathology Correlation Course, which is offered five times per year. On the penultimate day of the course, the best case presentation is held at the American Film Institute Silver Theater and Cultural Center in Silver Spring, Md. The AIRP faculty identifies the best cases, from each organ system, brought by the resident attendees. One or more of the best cases from each of the five courses are then solicited for publication in RadioGraphics. These cases emphasize the importance of radiologic-pathologic correlation in the imaging evaluation and diagnosis of diseases encountered at the institute and its predecessor, the Armed Forces Institute of Pathology (AFIP).


Assuntos
Abdome/diagnóstico por imagem , Abdome/patologia , Abdome/cirurgia , Cisto Dermoide/diagnóstico por imagem , Cisto Dermoide/patologia , Cisto Dermoide/cirurgia , Adulto , Meios de Contraste , Diagnóstico Diferencial , Humanos , Masculino
13.
Biochem Biophys Res Commun ; 459(1): 118-23, 2015 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-25721667

RESUMO

Bone formation requires the recruitment, proliferation and osteogenic differentiation of mesenchymal progenitors. A potent stimulus driving this process is mechanical loading, yet the signalling mechanisms underpinning this are incompletely understood. The objective of this study was to investigate the role of the mechanically-stimulated osteocyte and osteoblast secretome in coordinating progenitor contributions to bone formation. Initially osteocytes (MLO-Y4) and osteoblasts (MC3T3) were mechanically stimulated for 24 hrs and secreted factors within the conditioned media were collected and used to evaluate mesenchymal stem cell (MSC) and osteoblast recruitment, proliferation and osteogenesis. Paracrine factors secreted by mechanically stimulated osteocytes significantly enhanced MSC migration, proliferation and osteogenesis and furthermore significantly increased osteoblast migration and proliferation when compared to factors secreted by statically cultured osteocytes. Secondly, paracrine factors secreted by mechanically stimulated osteoblasts significantly enhanced MSC migration but surprisingly, in contrast to the osteocyte secretome, inhibited MSC proliferation when compared to factors secreted by statically cultured osteoblasts. A similar trend was observed in osteoblasts. This study provides new information on mechanically driven signalling mechanisms in bone and highlights a contrasting secretome between cells at different stages in the bone lineage, furthering our understanding of loading-induced bone formation and indirect biophysical regulation of osteoprogenitors.


Assuntos
Osteoblastos/fisiologia , Osteócitos/fisiologia , Animais , Osso e Ossos/citologia , Osso e Ossos/fisiologia , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Quimiotaxia , Meios de Cultivo Condicionados/farmacologia , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/fisiologia , Camundongos , Osteoblastos/citologia , Osteócitos/citologia , Osteogênese/efeitos dos fármacos , Estimulação Física
14.
Am J Orthop (Belle Mead NJ) ; 39(3): 137-40, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20463986

RESUMO

Slipped capital femoral epiphysis (SCFE) is an affliction of the hip presenting in adolescent children. There are several theories regarding the pathological cause of SCFE. The hormonal milieu during adolescence, combined with a deficiency in the physeal area of the growth plate, has been postulated as a possible etiology for its specific onset. In atypical circumstances, the early or late onset of SCFE may occur in the setting of unusual hormonal influences. This hormonal imbalance may be secondary to an underlying endocrinopathy-for example, hypothyroidism or hypogonadism. In this case, our patient presented with a clinically and radiographically unstable slip at the age of 22 years. His physical characteristics, along with confirmatory laboratory values and radiographs, indicated that the patient suffered from a disorder of delayed secondary growth. Subsequent thorough work-up revealed a large benign pituitary tumor that was causing severe panhypopituitarism. This article describes the presentation, diagnostic work-up and treatment of our patient with a delayed-onset SCFE in the setting of a pituitary tumor.


Assuntos
Craniofaringioma/complicações , Epifise Deslocada/complicações , Neoplasias Hipofisárias/complicações , Craniofaringioma/cirurgia , Epifise Deslocada/cirurgia , Fêmur/cirurgia , Humanos , Hipopituitarismo/complicações , Hipopituitarismo/cirurgia , Masculino , Neoplasias Hipofisárias/cirurgia , Índice de Gravidade de Doença , Resultado do Tratamento , Adulto Jovem
15.
Rev. biol. trop ; 56(3): 1471-1480, sep. 2008. graf, tab
Artigo em Espanhol | LILACS | ID: lil-637877

RESUMO

The crocodylid Crocodylus acutus is found in the Central Pacific of Costa Rica only in small populations, and the species is protected by law. RAPD was used to analyze 70 DNA samples of Crocodylus acutus from the rivers Jesus Maria, Tarcoles and Tusubres in the Central Pacific of Costa Rica in order to estimate genetic diversity, differentiation among populations, gene flow and genetic distance between them. Genetic diversity was low in the three rivers, H = 0.2201 in the Jesus Maria river, 0.2358 in the Tarcoles river and 0.2589 in the Tusubres river. Among the three populations there is a metapopulational dynamic (GST = 0.0367), mainly between the populations of the Jesus Maria and Tarcoles rivers. The value of gene flow (Nm = 13.1361) and the number of individuals reported for each river in 2004 suggests that the population of the Tarcoles river is the source and those from Jesus Maria and Tusubres are the drains. There was a direct relationship between the genetic distance and the geographical distance (z =1.1449, r =0.9731, p< 0.0010). A conservation strategy for these crocodiles must consider the existence of the metapopulation between the three rivers and the importance of studying the genetics of the American Crocodile in the rest of the Pacific coast of Costa Rica, as well as over the entire distribution range of this species. Rev. Biol. Trop. 56 (3): 1471-1480. Epub 2008 September 30.


Se utilizó la técnica de ADN Polimórfico Amplificado al Azar (RAPD) para analizar muestras de ADN de 70 individuos de C. acutus provenientes de los ríos Jesús María, Tárcoles y Tusubres en el Pacífico Central de Costa Rica para estimar la diversidad genética, la diferenciación entre poblaciones, el flujo genético y la distancia genética. La diversidad genética fue baja en los tres ríos H = 0.2201 en el río Jesús María, 0.2358 en el río Tárcoles y 0.2589 en el río Tusubres. La diversidad genética para el total de los individuos también fue baja, H = 0.2452. Entre las tres poblaciones hay una dinámica metapoblacional (G ST = 0.0367) principalmente en las poblaciones de los ríos Jesús María y Tárcoles. El valor de flujo genético (Nm = 13.1361) y el número de individuos registrado para cada río por Porras (2004) sugieren que la población del río Tárcoles está cumpliendo el papel de fuente y las de Jesús María y Tusubres constituyen los sumideros. Hubo relación directa entre la distancia genética y la distancia geográfica (z = 1.1449, r = 0.9731, p< 0.0010). Estos resultados indican la necesidad de diseñar una estrategia para la conservación de estos cocodrilos que considere la existencia de la metapoblación entre los tres ríos y también es importante realizar un estudio genético en el resto de la costa Pacífica del Costa Rica y en todo el ámbito de distribución de esta especie.


Assuntos
Animais , Jacarés e Crocodilos/genética , Fluxo Gênico/genética , Variação Genética/genética , Jacarés e Crocodilos/classificação , Costa Rica , Dinâmica Populacional , Técnica de Amplificação ao Acaso de DNA Polimórfico , Rios
16.
EMBO J ; 25(3): 605-14, 2006 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-16424903

RESUMO

The Arabidopsis genes FT and TERMINAL FLOWER1 (TFL1) encode related proteins with similarity to human Raf kinase inhibitor protein. FT, and likely also TFL1, is recruited to the promoters of floral genes through interaction with FD, a bZIP transcription factor. FT, however, induces flowering, while TFL1 represses flowering. Residues responsible for the opposite activities of FT and TFL1 were mapped by examining plants that overexpress chimeric proteins. A region important in vivo localizes to a 14-amino-acid segment that evolves very rapidly in TFL1 orthologs, but is almost invariant in FT orthologs. Crystal structures show that this segment forms an external loop of variable conformation. The only residue unambiguously distinguishing the FT and TFL1 loops makes a hydrogen bond with a residue near the entrance of a potential ligand-binding pocket in TFL1, but not in FT. This pocket is contacted by a C-terminal peptide, which also contributes to the opposite FT and TFL1 activities. In combination, these results identify a molecular surface likely to be recognized by FT- and/or TFL1-specific interactors.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Modelos Moleculares , Sequência de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Éxons , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Dados de Sequência Molecular , Peptídeos/metabolismo , Filogenia , Plantas Geneticamente Modificadas , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Homologia de Sequência de Aminoácidos
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