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1.
Front Surg ; 9: 1080584, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36620382

RESUMEN

Introduction: Current treatment strategies for primary upper extremity deep venous thrombosis (pUEDVT) range from conservative treatment with anticoagulation therapy to invasive treatment with thoracic outlet decompression surgery (TOD), frequently combined with catheter directed thrombolysis, percutaneous transluminal angioplasty, or stenting. Due to a lack of large prospective series with uniform data collection or a randomized trial, the optimal treatment strategy is still under debate. We conducted a multicenter observational study to assess the efficacy and safety of both the conservative and invasive treatment strategies for patients with pUEDVT. Methods: We retrospectively collected data from patients treated in five vascular referral and teaching hospitals in the Netherlands between 2008 and 2019. Patients were divided into a conservative (Group 1), an invasive treatment group (Group 2) and a cross-over group (Group 3) of patients who received surgical treatment after initial conservative therapy. Follow-up consisted of outpatient clinic visits and an electronic survey. Primary outcome was symptom free survival defined as absence of any symptom of the affected arm reported at last follow-up regardless of severity, or extent of functional disability. Secondary outcomes were incidence of bleeding complications, recurrent venous thromboembolism, surgical complications, and reinterventions. Results: A total of 115 patients were included (group 1 (N = 45), group 2 (N = 53) or group 3 (N = 27). The symptom free survival was 35.6%, 54.7% and 48.1% after a median follow-up of 36, 26 and 22 months in groups 1, 2 and 3 respectively. Incidence of bleeding complications was 8.6%, 3.8% and 18.5% and recurrent thrombosis occurred in 15.6%, 13.2% and 14.8% in groups 1-3 respectively. Conclusion: In this multicenter retrospective observational cohort analysis the conservative and direct invasive treatments for pUEDVT were deemed safe with low percentages of bleeding complications. Symptom free survival was highest in the direct surgical treatment group but still modest in all subgroups. Perioperative complications were infrequent with no related long term morbidity. Of relevance, pUEDVT patients with confirmed VTOS and recurrent symptoms after conservative treatment may still benefit from TOD surgery. However, symptom free survival of this delayed TOD seems lower than direct surgical treatment and bleeding complications seem to occur more frequently.

2.
Microbiol Spectr ; 9(2): e0053721, 2021 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-34668746

RESUMEN

UV light, more specifically UV-C light at a wavelength of 254 nm, is often used to disinfect surfaces, air, and liquids. In early 2020, at the cusp of the COVID-19 pandemic, UV light was identified as an efficient means of eliminating coronaviruses; however, the variability in published sensitivity data is evidence of the need for experimental rigor to accurately quantify the effectiveness of this technique. In the current study, reliable and reproducible UV techniques have been adopted, including accurate measurement of light intensity, consideration of fluid UV absorbance, and confirmation of uniform dose delivery, including dose verification using an established biological target (T1UV bacteriophage) and a resistant recombinant virus (baculovirus). The experimental results establish the UV sensitivity of SARS-CoV-2, HCoV-229E, HCoV-OC43, and mouse hepatitis virus (MHV) and highlight the potential for surrogate viruses for disinfection studies. All four coronaviruses were found to be easily inactivated by 254 nm irradiation, with UV sensitivities of 1.7, 1.8, 1.7, and 1.2 mJ/cm2/log10 reduction for SARS-CoV-2, HCoV-229E, HCoV-OC43, and MHV, respectively. Similar UV sensitivities for these species demonstrate the capacity for HCoV-OC43, HCoV-229E, and MHV to be considered surrogates for SARS-CoV-2 in UV-inactivation studies, greatly reducing hazards and simplifying procedures for future experimental studies. IMPORTANCE Disinfection of SARS-CoV-2 is of particular importance due to the global COVID-19 pandemic. UV-C irradiation is a compelling disinfection technique because it can be applied to surfaces, air, and water and is commonly used in drinking water and wastewater treatment facilities. UV inactivation depends on the dose received by an organism, regardless of the intensity of the light source or the optical properties of the medium in which it is suspended. The 254 nm irradiation sensitivity was accurately determined using benchmark methodology and a collimated beam apparatus for four coronaviruses (SARS-CoV-2, HCoV-229E, HCoV-OC43, and MHV), a surrogate indicator organism (T1UV), and a resistant recombinant virus (baculovirus vector). Considering the light distribution across the sample surface, the attenuation of light intensity with fluid depth, the optical absorbance of the fluid, and the sample uniformity due to mixing enable accurate measurement of the fundamental inactivation kinetics and UV sensitivity.


Asunto(s)
Coronavirus Humano 229E/efectos de la radiación , Coronavirus Humano OC43/efectos de la radiación , Virus de la Hepatitis Murina/efectos de la radiación , SARS-CoV-2/efectos de la radiación , Rayos Ultravioleta , Animales , Baculoviridae/efectos de la radiación , COVID-19/prevención & control , Línea Celular , Chlorocebus aethiops , Desinfección/métodos , Humanos , Células Vero
3.
Med Mycol Case Rep ; 30: 39-42, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33145152

RESUMEN

Mucormycosis is a life-threatening invasive fungal infection, most commonly described in severely immunocompromised patients. It is characterized by rapid invasive growth of the fungus and often with fatal outcome. We report a case of a renal transplant recipient diagnosed with a donor-derived invasive mucormycosis. In this patient, we used a step-wise approach of withdrawal of immunosuppressants, antifungal induction therapy, extensive surgical debridement of all (potentially) infected tissue, abdominal irrigation of liposomal amphotericin B and interferon gamma. Due to rapid diagnosis and intensive therapy the patient survived.

4.
Sci Rep ; 6: 38704, 2016 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-27929057

RESUMEN

Lithospheric extension can generate passive margins that bound oceans worldwide. Detailed geological and geophysical studies in present and fossil passive margins have highlighted the complexity of their architecture and their multi-stage deformation history. Previous modeling studies have shown the significant impact of coarse mechanical layering of the lithosphere (2 to 4 layer crust and mantle) on passive margin formation. We built upon these studies and design high-resolution (~100-300 m) thermo-mechanical numerical models that incorporate finer mechanical layering (kilometer scale) mimicking tectonically inherited heterogeneities. During lithospheric extension a variety of extensional structures arises naturally due to (1) structural softening caused by necking of mechanically strong layers and (2) the establishment of a network of weak layers across the deforming multi-layered lithosphere. We argue that structural softening in a multi-layered lithosphere is the main cause for the observed multi-stage evolution and architecture of magma-poor passive margins.

5.
Int. j. morphol ; 29(2): 537-542, June 2011. ilus
Artículo en Inglés | LILACS | ID: lil-597488

RESUMEN

Circovirus are viral agents that cause disease in avian species. The main clinical symptoms of the disease are immunosuppression and, in young birds feather disorders. In neonates, the disease is known as "black spot" and characterized by abdominal enlargement, hepatobiliar congestion and failure to thrive. Also, it wasobserved in adult infected birds with other symptoms and clinical signs, such as enteritis, sinusitis, rhinitis, tracheitis, bronchopneumonia, myocarditis, nephritis, splenitis, dyspnea, anorexia, depression leading to high mortality. In April 2008, 317 saffron finch were apprehended during an illegal commercialization and were forwarded to the Wild Animals Recovery Center of the Tiete Ecological Park. Subsequently, 101 (31.66 percent) died and 20 of these were selected and sent to the Laboratory of Electron Microscopy, Biological Institute of São Paulo, Brazil to investigate possible etiological agents. After necropsy of these animals fragments of lung, liver and small intestine were processed using negative staining and resin embedding techniques. On the transmission electron microscopy, the negative staining technique allowed observation in 20 (100 percent) samples of liver suspension, a great number of particles with morphology similar to the circovirus, spherical, non-enveloped, isometric, characterized as "complete" and "empty ", measuring between 17 and 20 nm in diameter. By the resin embedding technique, oval or rounded viral intracytoplasmatic inclusion bodies, containing viral particles disposed in paracrystalline arrays or loose arrangements were observed in ultrathin sections on the 20 (100 percent) samples of liver suspension. This is the first report on the presence of circovirus in saffron finch (Sicalis flaveola spp.).


Circovirus son agentes virales que causan enfermedad en las aves. Los principales síntomas clínicos de la enfermedad son la inmunosupresión y desórdenes en las plumas de aves jóvenes. En los recién nacidos la enfermedad se conoce como "punto negro" y se caracteriza por distensión abdominal, congestión hepatobiliar y falla en el desarrollo. También se han observado en las aves adultas infectadas, otros síntomas y signos clínicos, tales como la enteritis, sinusitis, rinitis, traqueitis, bronconeumonía, miocarditis, nefritis, esplenitis, disnea, anorexia, depresión llevando también a alta mortalidad. En abril de 2008, durante una comercialización ilegal, fueron confiscados 317 canarios venezolanos, siendo llevados al Centro de Rehabilitación de Animales Silvestres del Parque Ecológico de Tietê. Posteriormente, 101 (31,66 por ciento) aves murieron y entre éstas fueron seleccionadas 20 y enviadas al Laboratorio de Microscopía Electrónica, Instituto Biológico de São Paulo, para identificar el posible agente etiológico. Después de la necropsia, fragmentos de pulmón, hígado e intestino delgado se procesaron mediante las técnicas de tinción negativa y de inclusión en resina. A través de microscopía electrónica de transmisión, la técnica de tinción negativa permitió visualizar en las 20 muestras (100 por ciento) de suspensión del hígado, un gran número de partículas con morfología similar al circovirus, esférico, sin envoltura, isométrico, que se caracteriza como "completa" y "vacío", que miden entre 17 y 20 nm de diámetro. Mediante la técnica de cuerpos de inclusión en resina se observó en el 100 por ciento de las muestras de suspensión de hígado, cuerpos de inclusión virales intracitoplasmáticos, redondeadas u ovales, con partículas de virus dispuestos en matrices paracristalinas o sueltas en los cortes ultrafinos. Este es el primer reporte de la presencia de circovirus en canarios Venezolanos (Sicalis flaveola spp.).


Asunto(s)
Animales , Canarios , Circovirus/ultraestructura , Hígado/virología , Microscopía Electrónica de Transmisión
6.
Rehabilitation (Stuttg) ; 50(1): 11-6, 2011 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-21321819

RESUMEN

To enable self-determination and participation equal with others for persons with disabilities, the social insurance agencies involved in rehabilitation provide benefits for rehabilitation and participation. In order to initiate and perform those benefits individually and purposively, it is necessary to detect and assess a potential need early across social insurance agencies. This requirement was strengthened by the UN Convention on the Rights of Persons with Disabilities. The article outlines the legal background and practical framework conditions for the present assessment duty and refers to examples of existing methods for needs assessment, which in general are still too much aligned to specific benefits. In light of these circumstances, a need for action exists in order to implement legal demands relative to needs assessments across social insurance agencies and to advance approaches already in place.


Asunto(s)
Evaluación de la Discapacidad , Necesidades y Demandas de Servicios de Salud/legislación & jurisprudencia , Beneficios del Seguro/legislación & jurisprudencia , Programas Nacionales de Salud/legislación & jurisprudencia , Evaluación de Necesidades/legislación & jurisprudencia , Rehabilitación/legislación & jurisprudencia , Seguridad Social/legislación & jurisprudencia , Alemania
8.
Br J Surg ; 96(12): 1381-92, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19918850

RESUMEN

BACKGROUND: About 24 per cent of phaeochromocytomas (PCCs) and sympathetic paragangliomas (sPGLs) appear in familial cancer syndromes, including multiple endocrine neoplasia type 2, von Hippel-Lindau disease, neurofibromatosis type 1 and PCC-paraganglioma syndrome. Identification of these syndromes is of prime importance for patients and their relatives. Surgical resection is the treatment of choice for both PCC and sPGL, but controversy exists about the management of patients with bilateral or multiple tumours. METHODS: Relevant medical literature from PubMed, Ovid and Embase websites until 2009 was reviewed for articles on PCC, sPGL, hereditary syndromes and their treatment. DISCUSSION: Genetic testing for these syndromes should become routine clinical practice for those with PCC or sPGL. Patients should be referred to a clinical geneticist. Patients and family members with proven mutations should be entered into a standardized screening protocol. The preferred treatment of PCC and PGL is surgical resection; to avoid the lifelong consequences of bilateral adrenalectomy, cortex-sparing adrenalectomy is the treatment of choice.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/cirugía , Adrenalectomía/métodos , Neoplasia Endocrina Múltiple Tipo 2a/cirugía , Neoplasias del Sistema Nervioso/cirugía , Paraganglioma/cirugía , Enfermedad de von Hippel-Lindau/cirugía , Adolescente , Neoplasias de las Glándulas Suprarrenales/diagnóstico , Neoplasias de las Glándulas Suprarrenales/genética , Adulto , Niño , Preescolar , Pruebas Genéticas , Humanos , Lactante , Persona de Mediana Edad , Neoplasia Endocrina Múltiple Tipo 2a/diagnóstico , Neoplasia Endocrina Múltiple Tipo 2a/genética , Mutación/genética , Neoplasias del Sistema Nervioso/diagnóstico , Neoplasias del Sistema Nervioso/genética , Paraganglioma/diagnóstico , Paraganglioma/genética , Feocromocitoma/diagnóstico , Feocromocitoma/genética , Feocromocitoma/cirugía , Síndrome , Enfermedad de von Hippel-Lindau/diagnóstico , Enfermedad de von Hippel-Lindau/genética
9.
Gesundheitswesen ; 70(5): 267-80, 2008 May.
Artículo en Alemán | MEDLINE | ID: mdl-18604765

RESUMEN

The Health Advisory Board of the German Federal Association for Rehabilitation (BAR) describes future trends and challenges in rehabilitation as deriving from the socio-demographic development in Germany and the structural characteristics of its Social and Health Care Insurance System. The focus is on elder employees to sustain and regenerate their capacity for employment, on people which are no longer employed to activate their autonomy and ability for self-support, and on rehabilitation as a holistic and integrative process extending through the social security and health insurances. There is an urgent need and a real chance to benefit from already existing scientific findings more frequently and to integrate them effectively into adequate further education and training programmes for professionals. Finally the conclusion summarises 8 theses to facilitate rehabilitation as an integral and essential part of the German social security and health sector. This paper was fully accredited by the members of the BAR Managing Board.


Asunto(s)
Comités Consultivos , Predicción , Rehabilitación/tendencias
11.
Dis Aquat Organ ; 74(2): 113-8, 2007 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-17432040

RESUMEN

The ability of a range of doses of ultraviolet irradiation (UV) to inactivate the waterborne actinospore or triactinomyxon stages (TAMs) of Myxobolus cerebralis was evaluated by infectivity for juvenile rainbow trout Oncorhynchus mykiss. TAMs were UV-irradiated using a low pressure mercury vapour lamp collimated beam apparatus. All doses 40, 80, 120 and 160 mJ cm(-2) were found to completely inactivate the TAMs as demonstrated by the absence of microscopic lesions, myxospores and parasite DNA detected by quantitative PCR (qPCR) among rainbow trout 5 mo post-exposure. In contrast, rainbow trout receiving the same concentrations of untreated TAMs (1000 fish(-1)) developed clinical signs of whirling disease at 2 mo post-exposure and had severe microscopic lesions, high myxospore counts and high qPCR values when examined at 5 mo following exposure to the parasite.


Asunto(s)
Eucariontes/efectos de la radiación , Enfermedades de los Peces/parasitología , Oncorhynchus mykiss , Infecciones Protozoarias en Animales/parasitología , Rayos Ultravioleta , Animales , Relación Dosis-Respuesta en la Radiación , Eucariontes/patogenicidad , Esporas Protozoarias/patogenicidad , Esporas Protozoarias/efectos de la radiación , Factores de Tiempo , Agua/parasitología
12.
J Control Release ; 117(1): 51-8, 2007 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-17150277

RESUMEN

Poly(butyl cyanoacrylate) nanoparticles coated with poloxamer 188 (Pluronic) F68) and also, as shown previously, polysorbate 80 (Tween 80) considerably enhance the anti-tumour effect of doxorubicin against an intracranial glioblastoma in rats. The investigation of plasma protein adsorption on the surface of the drug-loaded nanoparticles by two-dimensional electrophoresis (2-D PAGE) revealed that both surfactants, besides other plasma components, induced a considerable adsorption of apolipoprotein A-I (ApoA-I). It is hypothesized that delivery of doxorubicin to the brain by means of nanoparticles may be augmented by the interaction of apolipoprotein A-I that is anchored on the surface of the nanoparticles with the scavenger receptor class B type I (SR-BI) located at the blood-brain barrier. This is the first study that shows a correlation between the adsorption of apolipoprotein A-I on the nanoparticle surface and the delivery of the drug across the blood-brain barrier.


Asunto(s)
Antibióticos Antineoplásicos/administración & dosificación , Antibióticos Antineoplásicos/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Cianoacrilatos , Doxorrubicina/administración & dosificación , Doxorrubicina/uso terapéutico , Glioblastoma/tratamiento farmacológico , Nanopartículas , Tensoactivos/química , Adsorción , Animales , Apolipoproteína A-I/metabolismo , Proteínas Sanguíneas/química , Barrera Hematoencefálica , Neoplasias Encefálicas/patología , Fenómenos Químicos , Química Física , Dextranos , Electroforesis en Gel de Poliacrilamida , Glioblastoma/patología , Tamaño de la Partícula , Poloxámero , Ratas , Análisis de Supervivencia
13.
Ann N Y Acad Sci ; 1073: 138-48, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17102080

RESUMEN

Pheochromocytomas (PCCs) are neuroendocrine tumors of chromaffin tissue that produce catecholamines. They are usually located in the adrenal medulla, although in about 10% the tumors arise from extra-adrenal chromaffin tissue. The majority of PCCs arise sporadically, but PCCs occur also in the context of hereditary cancer syndromes. Familial PCC is inherited as an autosomal dominant trait alone or as a component of the multiple endocrine neoplasia Type 2 (MEN2) syndrome (RET gene), Von Hippel-Lindau (VHL) disease (VHL gene), neurofibromatosis Type 1 (NF1 gene), or familial pheochromocytoma-paraganglioma (PCC-PGL) syndrome (SDHD/B and C genes). It has been reported that 24% of apparently sporadic PCCs patients harbor germline mutations in these PCC-causing genes. We investigated the contribution of the inherited PCC-causing genes in a partly retrospectively and partly prospectively obtained series of 213 apparently sporadic PCCs. Mutation analysis was performed for RET (56 cases), VHL (136 cases), and SDHD (126 cases) and SDHB (47 cases). No germline RET mutations, six (4.4%) germline VHL mutations, two (1.5%) germline SDHD mutations, and one germline (1.6%) SDHB mutation were found. In total we found germline mutations in about 7.5% of the investigated apparently sporadic PCCs. Although 7.5% germline mutations in a series of apparently sporadic PCCs are far less than the more than 20% reported in the literature, the figure is significant enough to consider germline mutation testing for each patient with PCC.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/genética , Feocromocitoma/genética , Predisposición Genética a la Enfermedad , Mutación de Línea Germinal , Humanos , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas c-ret/genética , Succinato Deshidrogenasa/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética
14.
J Pathol ; 209(2): 274-80, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16538614

RESUMEN

Mutations of the 'phosphatase and tensin homologue deleted on chromosome 10' (PTEN/MMAC1) gene have been associated with a variety of human cancers, including prostate cancer, glioblastoma, and melanoma. The gene is thought to be one of the most frequently mutated tumour suppressor genes and inactivation of PTEN is associated with disease progression and angiogenesis. High vascularization and resistance to chemo- and radio-therapy are two well-established features of phaeochromocytomas (PCCs). Furthermore, benign and malignant PCCs are found in several PTEN knockout mouse models. This study therefore evaluated whether inactivation of PTEN may be involved in the tumourigenesis of PCC in man and whether PTEN abnormalities may help to define the malignant potential of these tumours. Tumour and germline DNA was analysed from 31 patients with apparently sporadic PCC, including 14 clinically benign and 17 malignant tumours, for loss of the PTEN gene locus, mutations in the PTEN gene, and for PTEN protein expression by immunohistochemistry. Loss of heterozygosity (LOH) analysis showed loss of PTEN in four malignant tumours (40%) and in one benign tumour (14%). However, no mutations of PTEN were observed. Immunohistochemistry showed no correlation with clinical behaviour and/or LOH status. The results indicate that inactivation of the PTEN/MMAC1 gene may play a minor role in the development of malignant phaeochromocytomas.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/genética , Genes Supresores de Tumor/fisiología , Proteínas de Neoplasias/genética , Fosfohidrolasa PTEN/genética , Feocromocitoma/genética , Adolescente , Adulto , Anciano , Análisis Mutacional de ADN/métodos , ADN de Neoplasias/genética , Femenino , Silenciador del Gen/fisiología , Humanos , Inmunohistoquímica/métodos , Pérdida de Heterocigocidad/genética , Masculino , Persona de Mediana Edad , Polimorfismo Conformacional Retorcido-Simple
15.
J Biol Rhythms ; 16(2): 125-41, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11302555

RESUMEN

Increasing evidence indicates that the accessory medulla is the circadian pacemaker controlling locomotor activity rhythms in insects. A prominent group of neurons of this neuropil shows immunoreactivity to the peptide pigment-dispersing hormone (PDH). In Drosophila melanogaster, the PDH-immunoreactive (PDH-ir) lateral neurons, which also express the clock genes period and timeless, are assumed to be circadian pacemaker cells themselves. In other insects, such as Leucophaea maderae, a subset of apparently homologue PDH-ir cells is a candidate for the circadian coupling pathway of the bilaterally symmetric clocks. Although knowledge about molecular mechanisms of the circadian clockwork is increasing rapidly, very little is known about mechanisms of circadian coupling. The authors used a computer model, based on the molecular feedback loop of the clock genes in D. melanogaster, to test the hypothesis that release of PDH is involved in the coupling between bilaterally paired oscillators. They can show that a combination of all-delay- and all-advance-type interactions between two model oscillators matches best the experimental findings on mutual pacemaker coupling in L. maderae. The model predicts that PDH affects the phosphorylation rate of clock genes and that in addition to PDH, another neuroactive substance is involved in the coupling pathway, via an all-advance type of interaction. The model suggests that PDH and light pulses, represented by two distinct classes of phase response curves, have different targets in the oscillatory feedback loop and are, therefore, likely to act in separate input pathways to the clock.


Asunto(s)
Sistema Nervioso Central/fisiología , Ritmo Circadiano/fisiología , Insectos/fisiología , Algoritmos , Animales , Drosophila melanogaster/fisiología , Cinética , Modelos Biológicos , Neuronas/fisiología
16.
Cell Tissue Res ; 296(3): 635-43, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10370150

RESUMEN

The accessory medulla with its associated pigment-dispersing hormone-immunoreactive neurons appears to be the pacemaker that controls the circadian locomotor activity rhythm of the cockroach Leucophaea maderae. To permit studies at the level of individual, identified, pacemaker neurons, we developed specific long-term primary cell cultures of fully differentiated adult neurons of the accessory medulla. As judged from soma diameter distribution, the cultures contain an unbiased representation of apparently all neuronal types of the accessory medulla. The cultured cells survive and grow processes for more than 2 months with or without additional hemocyte coculturing. However, a strong positive effect on initial outgrowth was observed with hemocyte coculturing. At least six different morphological cell types of the accessory medulla could be distinguished in vitro. Among these only one cell type, the monopolar type C cell, was recognized in vitro with an antiserum against the neuropeptide pigment-dispersing hormone. Thus, the identifiable monopolar type C cells are candidates for circadian pacemaker neurons and will be the focus of further physiological characterizations.


Asunto(s)
Ritmo Circadiano , Hormonas de Insectos/metabolismo , Neuronas/citología , Neuronas/fisiología , Animales , Técnicas de Cultivo de Célula/métodos , Supervivencia Celular , Insectos , Pigmentos Biológicos
17.
Genetics ; 146(3): 1035-48, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9215906

RESUMEN

Analysis of mitochondrial DNA control region sequences from 41 species of bats representing 11 families revealed that repeated sequence arrays near the tRNA-Pro gene are present in all vespertilionine bats. Across 18 species tandem repeats varied in size from 78 to 85 bp and contained two to nine repeats. Heteroplasmy ranged from 15% to 63%. Fewer repeats among heteroplasmic than homoplasmic individuals in a species with up to nine repeats indicates selection may act against long arrays. A lower limit of two repeats and more repeats among heteroplasmic than homoplasmic individuals in two species with few repeats suggests length mutations are biased. Significant regressions of heteroplasmy, theta and pi, on repeat number further suggest that repeat duplication rate increases with repeat number. Comparison of vespertilionine bat consensus repeats to mammal control region sequences revealed that tandem repeats of similar size, sequence and number also occur in shrews, cats and bighorn sheep. The presence of two conserved protein-binding sequences in all repeat units indicates that convergent evolution has occurred by duplication of functional units. We speculate that D-loop region tandem repeats may provide signal redundancy and a primitive repair mechanism in the event of somatic mutations to these binding sites.


Asunto(s)
Quirópteros/genética , ADN Mitocondrial , Evolución Molecular , Secuencias Repetitivas de Ácidos Nucleicos , Animales , Secuencia de Bases , Gatos , Humanos , Mamíferos/genética , Datos de Secuencia Molecular , Mutación , Selección Genética , Homología de Secuencia de Ácido Nucleico
18.
J Neurosci ; 17(11): 4087-93, 1997 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-9151725

RESUMEN

An antiserum against the crustacean neuropeptide pigment-dispersing hormone stains a small set of neurons in the optic lobes of several hemimetabolous and holometabolous insects. These cells, the primary branches of which in the optic lobe lie in the accessory medulla, fulfill several criteria predicted for neurons of the circadian clock. For example, in fruit flies they express timeless and period, which are two molecular components of the circadian pacemaker. To test whether pigment-dispersing hormone fulfills a circadian function in the cockroach Leucophaea maderae, 150 fmol of synthetic peptide was injected into the vicinity of the accessory medulla. This resulted in a stable phase-dependent resetting of the phase of the circadian locomotor activity rhythm, which depended on the amount of pigment-dispersing hormone injected. The resulting phase-response curve differs from that obtained with light pulses, suggesting that pigment-dispersing hormone-immunoreactive neurons are not part of the visual input pathway to the pacemaker but an integral part of it and/or part of a nonphotic input into the clock. A possible role of these neurons in coupling the bilaterally paired circadian pacemakers is discussed.


Asunto(s)
Relojes Biológicos/efectos de los fármacos , Ritmo Circadiano/efectos de los fármacos , Péptidos/farmacología , Secuencia de Aminoácidos , Animales , Relojes Biológicos/fisiología , Ritmo Circadiano/fisiología , Cucarachas , Relación Dosis-Respuesta a Droga , Hormonas de Invertebrados/farmacología , Locomoción/efectos de los fármacos , Locomoción/fisiología , Microinyecciones , Datos de Secuencia Molecular , Neuropéptidos/farmacología
19.
Mol Ecol ; 6(3): 235-42, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9076978

RESUMEN

A hypervariable simple sequence locus and mitochondrial D-loop sequences were used to analyse genetically a natural population of the larger mouse-eared bat Myotis myotis in southern Bavaria. Tests for population subdivision and direct observations suggest that females return to their natal sites, while males disperse. The males present in female nursery colonies are not related to the females. Paternity assessment for 46 offspring from a particular nursery colony showed that there are no males that monopolize the reproduction, and that the resident males in the colony had only a small mating success. Instead, the results suggest that females actively seek matings outside their colony. Most interestingly, it appears that a group of males about 16 km away from the nursery colony had a relatively high mating success and that this group of males may be related to the females of the nursery colonies. If this finding can be confirmed in a larger study, it may have important consequences for future conservation strategies.


Asunto(s)
Quirópteros/genética , Animales , Secuencia de Bases , Quirópteros/fisiología , Cartilla de ADN/genética , ADN Mitocondrial/genética , Femenino , Genética de Población , Alemania , Masculino , Datos de Secuencia Molecular , Paternidad , Conducta Sexual Animal
20.
Biol Chem ; 377(10): 661-7, 1996 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8922595

RESUMEN

Mitochondrial heteroplasmy is shown to be extensive when amplification products from the mitochondrial control region are cloned and sequenced from a European bat species. In contrast, a mitochondrial ribosomal RNA gene does not exhibit substantial levels of heteroplasmy when analyzed in an identical way. In the bat, heteroplasmy with respect to length as well as sequence seems to be transmitted from mother to offspring. Thus, the intra-individual sequence diversity seems to accumulate within the female germ line and its extent to be controlled primarily by purifying selection. Similar experiments in humans and a marsupial suggest that heteroplasmy may not be as uncommon among mammals as hitherto thought.


Asunto(s)
Quirópteros/genética , ADN Mitocondrial/genética , Animales , Secuencia de Bases , Clonación Molecular , Femenino , Variación Genética , Impresión Genómica , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Secuencias Repetitivas de Ácidos Nucleicos
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