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1.
Antiviral Res ; 222: 105783, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38145755

RESUMEN

The human respiratory syncytial virus (hRSV) is the leading etiologic agent causing respiratory infections in infants, children, older adults, and patients with comorbidities. Sixty-seven years have passed since the discovery of hRSV, and only a few successful mitigation or treatment tools have been developed against this virus. One of these is immunotherapy with monoclonal antibodies against structural proteins of the virus, such as Palivizumab, the first prophylactic approach approved by the Food and Drug Administration (FDA) of the USA. In this article, we discuss different strategies for the prevention and treatment of hRSV infection, focusing on the molecular mechanisms against each target that underly the rational design of antibodies against hRSV. At the same time, we describe the latest results regarding currently approved therapies against hRSV and the challenges associated with developing new candidates.


Asunto(s)
Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Lactante , Niño , Humanos , Anciano , Antivirales/uso terapéutico , Palivizumab/uso terapéutico , Infecciones por Virus Sincitial Respiratorio/tratamiento farmacológico , Infecciones por Virus Sincitial Respiratorio/prevención & control , Anticuerpos Monoclonales/uso terapéutico
2.
Expert Opin Pharmacother ; 24(10): 1143-1158, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37165859

RESUMEN

INTRODUCTION: The human respiratory syncytial virus (hRSV) is the leading cause of respiratory infections in children, older adults, and patients with comorbidities. Since the hRSV discovery, multiple efforts have been made to generate therapies that control the devastating effects on the population at risk in winter. AREAS COVERED: This article describes the development of different drugs and treatments approved for use in the risk-population against hRSV infection. In addition, an exhaustive bibliographical review is presented here describing new candidate molecules under evaluation and showing promising results in different assays in animal models and clinical studies. Additionally, we highlight antiviral molecules, monoclonal antibodies, and nanobodies among the new candidate treatments. EXPERT OPINION: hRSV is a major burden for the health systems, promoting their collapse worldwide. Therefore, developing new therapies is an essential goal to decrease hospitalization rates caused by hRSV infection in high-risk populations. For this, injecting resources and exploring new targets in addition to the F protein is an interesting alternative to achieve this goal.


Asunto(s)
Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Infecciones del Sistema Respiratorio , Niño , Animales , Lactante , Humanos , Anciano , Antivirales/farmacología , Antivirales/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Infecciones del Sistema Respiratorio/tratamiento farmacológico
3.
Theriogenology ; 196: 214-226, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36427390

RESUMEN

Much effort has been employed to improve the quality of embryos obtained by in vitro production (IVP) given the relevance of this technology to current livestock systems. In this context, dynamic IVP systems have proved beneficial to the embryo once they mimic fluid flows and mechanical forces resulting from the movement of ciliated cells and muscle contraction in the reproductive tract. In the present study, we sought to confirm these initial findings as well as assess potential molecular consequences to the embryo by applying micro-vibration (45 Hz for 5 s once per 60 min) during both oocyte maturation and embryo culture in cattle. As a result, micro-vibration led to lower incidence of apoptosis in blastocysts following vitrification-thawing. Further analyses revealed epigenetic and transcriptional changes in blastocysts derived from the micro-vibration treatment, with a total of 502 differentially expressed genes. Enrichment analyses linked differentially expressed genes to 'Oxidative phosphorylation', 'Cytokine-cytokine receptor interaction', and 'Signaling pathways regulating pluripotency of stem cells'. Yet, a meta-analysis indicated that the transcriptional changes induced by micro-vibration were not toward that of in vivo-derived embryos. In conclusion, micro-vibration increases the cryoresistance of bovine embryos, but caution should be taken given the unclear consequences of epigenetic and transcriptional abnormalities induced by the treatment.


Asunto(s)
Epigenómica , Transducción de Señal , Animales , Bovinos/genética , Células Madre
4.
New Microbes New Infect ; 49: 101041, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36320316

RESUMEN

Introduction: Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has spread globally, becoming a long-lasting pandemic. Dengue is the most common arboviral disease in tropical and subtropical regions worldwide. COVID-19 and dengue coinfections have been reported, associated with worse outcomes with significant morbidity and mortality. Therefore, this study aims to determine the epidemiological situation of COVID-19 and dengue coinfection in Latin America. Methods: A systematic literature review was performed using PubMed, Scopus, Embase, Web of Science, LILACS, and BVS databases from January 1, 2020, to September 4, 2021. The key search terms used were "dengue" and "COVID-19". Results: Nineteen published articles were included. The studies were case reports with a detailed description of the coinfection's clinical, laboratory, diagnostic, and treatment features. Conclusion: Coinfection with SARS-CoV-2 and dengue virus is associated with worse outcomes with significant morbidity and mortality. The similar clinical and laboratory features of each infection are a challenge in accurately diagnosing and treating cases. Establishing an early diagnosis could be the answer to reducing the estimated significant burden of these conditions.

5.
West Indian med. j ; West Indian med. j;67(2): 157-159, Apr.-June 2018. tab
Artículo en Inglés | LILACS | ID: biblio-1045829

RESUMEN

ABSTRACT Objective: To identify cardiac risk factors that contribute to sudden cardiac death in a haemodialysis population and thus optimize them, in an effort to minimize death in this population. Methods: This was a retrospective study and audit. The medical records of the patients receiving chronic haemodialysis were reviewed for the period January to December 2014. Data collected included age, gender, comorbidities, types of access, length of time on haemodialysis, laboratory indices, and main electrocardiographic and echocardiographic findings. Results: All patients had elevated intact parathyroid hormone. Some patients had hypocalcaemia, hyperphosphataemia and mild anaemia. Prominent echocardiographic findings were left ventricular hypertrophy and pulmonary hypertension. Conclusion: Sudden cardiac death in end-stage renal disease patients on haemodialysis may be predicted by certain abnormal laboratory findings and echocardiographic findings which may all be positively correlated.


RESUMEN Objetivo: Identificar los factores de riesgo cardíaco que contribuyen a la muerte cardíaca súbita en una población de hemodiálisis, y de este modo optimizarlos, en un esfuerzo por minimizar los fallecimientos por tal motivo en esta población. Métodos: Se trata de un estudio retrospectivo y auditoría. Se revisaron las historias clínicas de los pacientes que recibían hemodiálisis crónica, correspondientes al período de enero a diciembre de 2014. Los datos recogidos incluyeron edad, sexo, comorbilidades, tipos de acceso, tiempo de hemodiálisis, índices de laboratorio, y los principales hallazgos electrocardiográficos y ecocardiográficos. Resultados: Todos los pacientes tenían hormona paratiroides intacta elevada. Algunos pacientes tenían hipocalcemia, hiperfosfatemia y anemia leve. Los resultados ecocardiográficos más sobresalientes fueron la hipertrofia ventricular izquierda y la hipertensión pulmonar. Conclusión: La muerte cardíaca repentina en pacientes con la enfermedad renal en fase terminal sujetos a hemodiálisis, puede predecirse por ciertos resultados de laboratorio anormales y los resultados de la ecocardiografía, todos los cuales se pueden correlacionar positivamente.


Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Anciano , Adulto Joven , Diálisis Renal , Muerte Súbita Cardíaca/prevención & control , Trinidad y Tobago , Ecocardiografía , Estudios Retrospectivos , Factores de Riesgo , Electrocardiografía
6.
J Environ Sci Health B ; 51(4): 215-21, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26766580

RESUMEN

The aims of this research were to evaluate the efficacy of copper oxychloride (CuCl2.3Cu(OH)2), copper hydroxide (Cu(OH)2) and diquat (1.1'-ethylene-2.2'-bipyridyldiylium dibromide), isolated and in association with 0.1% of both copper sources, in the control of the unicellular algae Ankistrodesmus gracilis and the filamentous algae Pithophora kewesis, and to determine the acute toxicity of the tested chemicals in Hyphressobrycon eques, Pomacea canaliculata, Lemna minor and Azolla caroliniana. The efficacy was estimated by the methods of chlorophyll a and pheophytin a readings, changed into growth inhibition percentage. Both algae were exposed to the following concentrations: 0.2; 0.4; 0.8; 1.2 mg L(-1) of diquat and its association with the copper sources; and 0.1; 0.3; 0.5; 0.7; 1.0 and 1.5 mg L(-1) in the isolated applications of copper hydroxide and copper oxychloride. An untreated control was kept. The acute toxicity was estimatedby 50% lethal concentration (LC50). The copper sources were effective for A. gracilis control, at rates as high as 0.1 mg L(-1) (>95% efficacy). Isolated diquat and its association with copper hydroxide were both effective at rates as high as 0.4 mg L(-1), with 95 and 88% control efficacy, respectively. The copper oxychloride was effective at 0.2 mg L(-1), with 93% efficacy. None of the tested chemicals and associations was effective on P. kewesis control. The most sensitive non target organism to the tested chemicals was L. minor; the less sensitive was H. eques.


Asunto(s)
Chlorophyta/efectos de los fármacos , Cobre/farmacología , Diquat/farmacología , Ecotoxicología/métodos , Hidróxidos/farmacología , Araceae/efectos de los fármacos , Clorofila/metabolismo , Clorofila A , Cobre/toxicidad , Diquat/toxicidad , Hidróxidos/toxicidad , Feofitinas/metabolismo , Especificidad de la Especie , Pruebas de Toxicidad Aguda/métodos
7.
Arq. bras. neurocir ; 34(2): 148-152, jun. 2015. ilus
Artículo en Portugués | LILACS | ID: biblio-1979

RESUMEN

Angiolipomas são neoplasias benignas compostas por adipócitos maduros e proliferação vascular angiomatosa de rara ocorrência no Sistema Nervoso Central. É relatado o caso de angiolipoma em cisterna silviana adjacente a aneurisma sacular de artéria cerebral média. São discutidas as características imagenológicas do tumor e a possibilidade de uma origem comum com lesões vasculares intracranianas. Este é o primeiro caso relatado de angiolipoma intracraniano associado a aneurisma de artéria cerebral média.


Angiolipomas are benign neoplasms composed of mature fat cells and vascular angiomatous proliferation of rare incidence in Central Nervous System.It's related a case of angiolipoma in Sylvian fissure associated with cerebral saccular aneurysm of medial cerebral artery. Imagenologic characteristics of the tumor and a possible common origin with intracranial vascular lesions are discussed. This is the first reported case of intracranial angiolipoma involving medial cerebral artery aneurysm.


Asunto(s)
Humanos , Masculino , Adulto , Neoplasias Encefálicas , Angiolipoma/complicaciones , Arteria Cerebral Media/patología , Aneurisma/complicaciones , Cefalea/etiología
8.
Acta biol. colomb ; 20(1): 129-139, ene.-abr. 2015. ilus, tab
Artículo en Español | LILACS | ID: lil-734906

RESUMEN

Un paso crucial en el desarrollo de un inmunosensor piezoeléctrico para la detección de tuberculosis (TB), es la selección y obtención de los inmunoreactivos empleados en el inmunoensayo y la estrategia para la biofuncionalización del transductor. Diversos estudios han reportado el uso del antígeno proteico 38kDa (Ag38kDa) de Mycobacterium tuberculosis (Mtb) como un buen biomarcador de la enfermedad y el cumplimiento de las características físicas y bioquímicas para ser inmovilizado por monocapas autoensambladas (SAMs), en la superficie del electrodo de oro de cristales piezoeléctricos. Un inmunosensor piezoeléctrico desarrollado a partir de un antígeno nativo purificado de Mtb podría ser un método alternativo simple para la detección de Mtb con ventajas de rapidez y reusabilidad, contribuyendo al control y el tratamiento oportuno de la enfermedad. En este estudio se presenta el proceso de purificación del Ag38kDa a partir de proteínas de secreción filtradas de cultivo (CFP) de Mtb para ser usado como inmunoreactivo con potencial aplicación en la detección de Mtb con inmunosensores piezoeléctricos. Se obtuvieron cristales funcionalizados mediante la técnica modificada de monocapas autoensambladas (SAMs), con el antígeno nativo purificado y CFP. Las superficies biofuncionalizadas fueron caracterizadas cualitativamente con microscopía de fuerza atómica (AFM) para validar las condiciones de optimización del protocolo de inmovilización con antígenos de secreción de Mtb. Estos cristales modificados pueden ser acoplados a un sistema de caracterización de un inmunosensor piezoeléctrico para la detección de Mtb mediante un inmunoensayo competitivo directo.


The selection and procurance of the immunoreagents used in the immunoassay and biofunctionalisation transducer strategy, are a key in the piezoelectric immunosensor development for the detection of tuberculosis (TB). Many have reported the use of 38kDa protein antigen (Ag38kDa) from Mycobacterium tuberculosis (Mtb) such as good biomarker of TB disease and compliance with physical and biochemical characteristics to be immobilized by self-assembled monolayers (SAMs), in the gold electrode of piezoelectrics crystals surfaces. A piezoelectric immunosensor developed from purified native antigens of Mtb may be an alternative simple method for detection of Mtb with speed and reusable advantages, contributing to the control and early treatment of disease. In this paper, the purification process of Ag38kDa Mtb from secretory proteins filtered culture (CFP) from Mtb is presented as an immunoreactive with potential application in the detection of Mtb by piezoelectric immunosensors. Functionalized crystals were obtained by using the modified self-assembled monolayers (SAMs) technique, with purified native antigen and CFP. The functionalized surfaces were qualitatively characterized using atomic force microscopy (AFM) in order to validate the immobilization protocol optimal conditions for secretion antigens from Mtb. These modified crystals may be coupled to piezoelectric immunosensor characterization system for detecting of Mtb by a direct competition immunoassay.

9.
In. Caribbean Public Health Agency. Caribbean Public Health Agency: 60th Annual Scientific Meeting. Kingston, The University of the West Indies. Faculty of Medical Sciences, 2015. p.[1-75]. (West Indian Medical Journal Supplement).
Monografía en Inglés | MedCarib | ID: med-17954

RESUMEN

OBJECTIVE: The objective of the study was to examine the extent of, and factors related to, condom use in Turks and Caicos Islands (TCI). DESIGN AND METHODS: The study was based on secondary analysis of 775 sexually active respondents who completed the interviewer administered Knowledge, Attitudes, Practices and Beliefs survey in 2011. Condom use at last sex was modelled in logistic regression with demographics, HIV awareness, condom use self-efficacy (CUSE), sexual behaviors and substance use as predictors. Moderation between self-efficacy and age of sexual partner was also assessed in the model. Finally, the frequency of reasons expressed for non-condom use was explored. RESULTS: Most (54%) respondents did not use condoms at last sexual intercourse. Additionally, lower age (OR = 0.97; 95% CI = 0.95 – 0.99), not being married (OR = 3.87; (95% CI = 2.50 – 5.99), more than one sexual partner (OR = 4.70; 95% CI = 2.83 – 7.82), and having sex while intoxicated (OR = 2.34; 95% CI = 1.25 – 4.39) were all related to condom use. Higher CUSE was also related to higher condom use but only when the sexual partner was younger. Finally, the greatest expressed reason for non-condom use was trust in one’s partner. CONCLUSION: The study found condom use to be related to several of the factors examined. This information can be used to forge a targeted condom promotion campaign; an approach that may prove both efficient and cost effective in resource limited TCI. Suggestions for tailored messages and implications for future research are discussed.


Asunto(s)
Condones , Región del Caribe
10.
Med. lab ; 21(7/8): 311-332, 2015. tab, ilus
Artículo en Español | LILACS | ID: biblio-907779

RESUMEN

Resumen: la tuberculosis es un problema de salud pública que afecta a millones de personas, siendo la cuarta causa de muerte por enfermedad infecciosa en el mundo. En su más reciente reporte, la Organización Mundial de la Salud (OMS) menciona que la infección tuberculosa es curable con un tratamiento adecuado; sin embargo, es una necesidad la detección precoz de casos y la mejora del diagnóstico como medida de control. En esta revisión se presenta una recopilación de los métodos de detección de tuberculosis desde los tradicionales hasta las nuevas alternativas en desarrollo. Como métodos convencionales de diagnóstico para la detección de la tuberculosis se han usado el examen directo con coloración de esputo y el cultivo para determinar la presencia de la micobacteria; estos métodos presentan desventajas importantes que afectan la sensibilidad y tiempo para el diagnóstico.Recientes avances en pruebas rápidas incluyen el desarrollo de técnicas moleculares e inmunoensayosque pueden detectar micobacterias resistentes a antibióticos y anticuerpos de la respuesta inmune del hospedero. Sin embargo, esta enfermedad no cuenta con una prueba de diagnóstico precisa que permita la detección y el diagnóstico rápido con la mínima pérdida de pacientes. Frente a estos retos, en la actualidad se encuentran en desarrollo nuevas pruebas basadas en biosensores mediante el uso de biomarcadores adecuados de la enfermedad.


Abstract: Tuberculosis is a public health problem that affects millions of people, being the fourth common cause of death due infectious disease in the world. In a recent report, the World Health Organization (WHO) argues that tuberculosis infection is curable with proper treatment; however its early detection and improved diagnosis tools are necessary for tuberculosis control. In this review, a compilation of methods for detecting tuberculosis from traditional to new developing alternatives are presented. As conventional diagnostic methods for detecting tuberculosis have been used direct sputumsmear and cell culture to establish the presence of mycobacteria; however, these methods have significant disadvantages which include sensitivity and time for diagnosis. Among recent advances in rapid tests are the development of molecular techniques and immunoassays to detect antibiotics mycobacteria resistance and antibodies from the host immune response. However, this disease does not have an accuracy diagnostic test that allows rapid detection and diagnosis with minimal loss of patients. Currently, to deal with these challenges, new tests based on biosensors are developing, using appropriate biomarkers of disease.


Asunto(s)
Humanos , Técnicas Biosensibles , Medios de Cultivo , Prueba de Tuberculina , Tuberculosis
11.
Univ. psychol ; 11(1): 207-215, ene.-abr. 2012. tab
Artículo en Español | LILACS-Express | LILACS | ID: lil-659548

RESUMEN

Este estudio presenta el proceso de desarrollo del Cuestionario de Experiencias de Violencia en las Relaciones de Pareja y Familia en Estudiantes Universitarios, así como sus propiedades psicométricas y hallazgos a través de un estudio piloto. El diseño utilizado fue no experimental, transversal correlacional con una muestra por disponibilidad de 267 estudiantes. En la versión final, el instrumento consta de 41 reactivos y cuatro subescalas: Violencia de la Pareja hacia el Estudiante, Violencia del Estudiante hacia la Pareja, Violencia Observada entre los Padres y Violencia de los Padres hacia el Estudiante. La escala total y las subescalas obtuvieron índices de confiabilidad adecuados. En promedio, la muestra endosó diez experiencias de violencia en diversos contextos. Los hallazgos de este estudio aportan al conocimiento de la prevalencia de la violencia en múltiples contextos, viabilizando el diseño de intervenciones pertinentes en el manejo y prevención de la violencia en poblaciones universitarias.


This study describes the process of developing the Experiences of Violence in Couple and Family Relationships in University Students Questionnaire, its psychometric properties and the results of the pilot study. The research design used for this study was a nonexperimental, transversal co relational design. The nonrandomized sample consisted of 267 students. The final version of the questionnaire consisted of 41 items and four sub-scales which measured experiences with violence in a relationship as an Aggressor and as a Victim, Observed between the Parents and in the Parent-child relationship as a victim. The total scale and the subscales obtained adequate reliability indexes. On average, the sample reported ten experiences with violence in different contexts. The results of this study contribute data on the prevalence of violence in college students' romantic and family relationships which in turn, provide valuable information for planning prevention and early intervention efforts with this population.

12.
Med Vet Entomol ; 23 Suppl 1: 1-7, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19335824

RESUMEN

The economic devastation caused in the past by the New World screwworm fly Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) to the livestock industry in the U.S.A., Mexico and the rest of Central America was staggering. The eradication of this major livestock pest from North and Central America using the sterile insect technique (SIT) as part of an area-wide integrated pest management (AW-IPM) programme was a phenomenal technical and managerial accomplishment with enormous economic implications. The area is maintained screwworm-free by the weekly release of 40 million sterile flies in the Darien Gap in Panama, which prevents migration from screwworm-infested areas in Columbia. However, the species is still a major pest in many areas of the Caribbean and South America and there is considerable interest in extending the eradication programme to these countries. Understanding New World screwworm fly populations in the Caribbean and South America, which represent a continuous threat to the screwworm-free areas of Central America and the U.S.A., is a prerequisite to any future eradication campaigns. The Old World screwworm fly Chrysomya bezziana Villeneuve (Diptera: Calliphoridae) has a very wide distribution ranging from Southern Africa to Papua New Guinea and, although its economic importance is assumed to be less than that of its New World counterpart, it is a serious pest in extensive livestock production and a constant threat to pest-free areas such as Australia. In the 1980s repeated introductions and an expansion of Old World screwworm populations were reported in the Middle East; in the 1990s it invaded Iraq and since late 2007 it has been reported in Yemen, where a severe outbreak of myiasis occurred in 2008. Small-scale field trials have shown the potential of integrating the SIT in the control of this pest and various international organizations are considering using the release of sterile insects as part of an AW-IPM approach on a much wider scale. Wohlfahrtia magnifica (Schiner) (Diptera: Sarcophagidae) is a screwworm of temperate regions, which, although of limited agricultural importance, has invaded several new locations in the past few years. This special issue reports on the results of a 6-year project funded by the Joint Food and Agriculture Organization of the United Nations/International Atomic Energy Agency (FAO/IAEA) Programme of Nuclear Techniques in Food and Agriculture entitled 'Enabling Technologies for the Expansion of the SIT for Old and New World Screwworm'. A major goal of the project was to better understand population genetic variation in screwworms as an aid to the identification of isolated populations. The project also addressed issues related to genetic sexing, cuticular hydrocarbons, population dynamics, genetic transformation and chromosome analysis.


Asunto(s)
Infección por Gusano Barrenador/prevención & control , Infección por Gusano Barrenador/veterinaria , Animales , Animales Domésticos/parasitología , América Central , ADN/genética , Dípteros/patogenicidad , Femenino , Resistencia a los Insecticidas , Masculino , México , Infección por Gusano Barrenador/epidemiología , Cromosomas Sexuales/genética
13.
Genome ; 52(1): 20-30, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19132068

RESUMEN

The present study constitutes the first attempt to construct a polytene chromosome map of an Anastrepha species, Anastrepha ludens (Loew), a major agricultural pest. The mitotic karyotype has a diploid complement of 12 acrocentric chromosomes, including five pairs of autosomes and an XX/XY sex chromosome pair. The analysis of salivary gland polytene chromosomes has shown a total number of five polytene elements that correspond to the five autosomes. The characteristic features and the most prominent landmarks of each chromosome are described. By comparing chromosome banding patterns, the possible chromosomal homology between A. ludens and Ceratitis capitata (Wiedemann) is presented. This work shows that polytene maps of A. ludens are suitable for cytogenetic studies in this species and may be used as reference for other Anastrepha species, most of which are also serious agricultural pests.


Asunto(s)
Cromosomas/ultraestructura , Mitosis , Tephritidae/genética , Animales , Bandeo Cromosómico , Mapeo Cromosómico , Citogenética , Cariotipificación , Larva/genética , Modelos Genéticos , Glándulas Salivales/patología , Cromosomas Sexuales
14.
Bull Entomol Res ; 97(5): 471-88, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17916266

RESUMEN

If species-specific male genitalia are courtship devices under sexual selection by cryptic female choice, then species-specific aspects of the morphology and behaviour of male genitalia should often function to stimulate the female during copulation. The morphology and behaviour of the complex, species-specific male genitalia of the tsetse fly, Glossina pallidipes Austen, were determined from both direct observations and dissections of flash-frozen copulating pairs; we found that some male genitalic traits probably function to stimulate the female, while others function to restrain her. The male clamps the ventral surface of the female's abdomen tightly with his powerful cerci. Clamping does not always result in intromission. Clamping bends the female's body wall and her internal reproductive tract sharply, posteriorly and dorsally, and pinches them tightly. The male performed sustained, complex, stereotyped, rhythmic squeezing movements with his cerci that were not necessary to mechanically restrain the female and appeared instead to have a stimulatory function. Six different groups of modified setae on and near the male's genitalia rub directly against particular sites on the female during squeezing. The designs of these setae correlate with the force with which they press on the female and the probable sensitivity of the female surfaces that they contact. As expected under the hypothesis that these structures are under sexual selection by female choice, several traits suspected to have stimulatory functions have diverged in G. pallidipes and its close relative, G. longipalpis. Additional male non-genitalic behaviour during copulation, redescribed more precisely than in previous publications, is also likely to have a courtship function. The elaborate copulatory courtship behaviour and male genitalia may provide the stimuli that previous studies showed to induce female ovulation and resistance to remating.


Asunto(s)
Evolución Biológica , Copulación , Genitales Femeninos/anatomía & histología , Genitales Masculinos/anatomía & histología , Moscas Tse-Tse/fisiología , Animales , Femenino , Genitales Femeninos/fisiología , Genitales Masculinos/fisiología , Masculino , Preferencia en el Apareamiento Animal , Especificidad de la Especie , Moscas Tse-Tse/anatomía & histología
17.
Genetica ; 116(1): 5-13, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12484522

RESUMEN

The introduction of genetic sexing strains (GSS) into medfly, Ceratitis capitata (Wiedemann), sterile insect technique (SIT) programmes started in 1994 and it was accompanied by extensive evaluation of the strains both in field cages and in open field situations. Two male-linked translocation systems, one based on pupal colour, wp, and the other based on temperature sensitivity, tsl, have been used in medfly SIT programmes and they have quite different impacts on mass rearing strategy. In strains based on tsl, female zygotes are killed using high temperature and for wp strains, female and male pupae are separated based on their colour. In all these systems the colony females are homozygous for the mutation requiring that the mutation is not too deleterious and the males are also semi-sterile due to the presence of a male-linked translocation. Managing strain stability during large-scale mass rearing has presented some problems that have been essentially solved by selecting particular translocations for GSS and by the introduction of a filter rearing system (FRS). The FRS operates by removing from the colony any recombinant individuals that threaten the integrity of the strain. The use of GSS opens up the possibility of using the SIT for suppression as opposed to eradication and different radiation strategies can be considered. Some of the many field trials of the strains that were carried out before the strains were introduced into operational programmes are reviewed and an overview is given of their current use.


Asunto(s)
Ceratitis capitata/genética , Control Biológico de Vectores/métodos , Animales , Argentina , Islas del Atlántico , Australia , Ceratitis capitata/fisiología , Entomología/métodos , Estudios de Factibilidad , Femenino , Predicción , Genes Recesivos , Guatemala , Infertilidad Masculina/genética , Masculino , Control Biológico de Vectores/economía , Pupa , Selección Genética , Preselección del Sexo/métodos , Sudáfrica , Temperatura , Translocación Genética
19.
Biotechnol Bioeng ; 63(5): 552-8, 1999 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-10397811

RESUMEN

Misfolding and misassembly of proteins are major problems in the biotechnology industry, in biochemical research, and in human disease. Here we describe a novel approach for reversing aggregation and increasing refolding by application of hydrostatic pressure. Using P22 tailspike protein as a model system, intermediates along the aggregation pathway were identified and quantitated by size-exclusion high-performance liquid chromatography (HPLC). Tailspike aggregates were subjected to hydrostatic pressures of 2.4 kbar (35,000 psi). This treatment dissociated the tailspike aggregates and resulted in increased formation of native trimers once pressure was released. Tailspike trimers refolded at these pressures were fully active for formation of infectious viral particles. This technique can facilitate conversion of aggregates to native proteins without addition of chaotropic agents, changes in buffer, or large-scale dilution of reagents required for traditional refolding methods. Our results also indicate that one or more intermediates at the junction between the folding and aggregation pathways is pressure sensitive. This finding supports the hypothesis that specific determinants of recognition exist for protein aggregation, and that these determinants are similar to those involved in folding to the native state. An increased understanding of this specificity should lead to improved refolding methods.


Asunto(s)
Glicósido Hidrolasas/química , Proteínas de la Cola de los Virus/química , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Electroforesis en Gel de Poliacrilamida , Presión Hidrostática , Conformación Proteica , Pliegue de Proteína , Espectrometría de Fluorescencia
20.
Medicina (B Aires) ; 59(4): 327-31, 1999.
Artículo en Español | MEDLINE | ID: mdl-10752195

RESUMEN

Bone marrow (BM) and peripheral blood stem cell (PBSC) samples from patients undergoing autologous transplant were tested to evaluate the effects of cryopreservation. Cell viability was assessed as well as the proliferative capability of CFU-GM and BFU-E (myeloid and erythroid progenitors respectively). Moreover, long term culture (LTC) of stromal cells was used to test their functionality. A total of 23 samples were studied: 5 from AML patients, 7 MM, 6 NHL, 3 ALL and 2 HL. Nine patients received autologous bone marrow transplant (ABMT) and the remaining 14 PBSC. The cells were frozen during 24 to 33 days before infusion and 16 to 40 months before culture. Forty percent of AML and MM samples gave rise to colonies in vitro while the other hematology diseases tested showed colony growth in almost 100% of the cases. Samples from patients with lymphoid diseases exhibited a good correlation between the percentage of CD34+ cells and the number of colonies developed in culture. Nevertheless, there was no correlation when ALL and MM were tested suggesting that the underlying disease may have affected the growth in culture. The stromal layer was fully developed on BM samples, but on PBSC samples it only generated macrophages and fibroblasts. Our results suggest that the efficacy of cryopreservation of hematopoietic cells can be measured by means of CFU-GM and BFU-E culture and that the period the samples remained frozen did not affect the growth capability of the cells.


Asunto(s)
Criopreservación , Neoplasias Hematológicas/terapia , Células Madre Hematopoyéticas/fisiología , Adulto , Examen de la Médula Ósea , Trasplante de Médula Ósea , Supervivencia Celular , Humanos , Persona de Mediana Edad , Factores de Tiempo , Trasplante Autólogo
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