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1.
J Infect Dis ; 210(8): 1217-27, 2014 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-24740633

RESUMEN

BACKGROUND: The iPrEx study demonstrated that combination oral emtricitabine and tenofovir disoproxil fumarate (FTC/TDF) as preexposure prophylaxis (PrEP) protects against HIV acquisition in men who have sex with men and transgender women. Selection for drug resistance could offset PrEP benefits. METHODS: Phenotypic and genotypic clinical resistance assays characterized major drug resistant mutations. Minor variants with FTC/TDF mutations K65R, K70E, M184V/I were measured using 454 deep sequencing and a novel allele-specific polymerase chain reaction (AS-PCR) diagnostic tolerant to sequence heterogeneity. RESULTS: Control of primer-binding site heterogeneity resulted in improved accuracy of minor variant measurements by AS-PCR. Of the 48 on-study infections randomized to FTC/TDF, none showed FTC/TDF mutations by clinical assays despite detectable drug levels in 8 participants. Two randomized to FTC/TDF had minor variant M184I detected at 0.53% by AS-PCR or 0.75% by deep sequencing, only 1 of which had low but detectable drug levels. Among those with acute infection at randomization to FTC/TDF, M184V or I mutations that were predominant at seroconversion waned to background levels within 24 weeks after discontinuing drug. CONCLUSIONS: Drug resistance was rare in iPrEx on-study FTC/TDF-randomized seroconverters, and only as low-frequency minor variants. FTC resistance among those initiating PrEP with acute infection waned rapidly after drug discontinuation. Clinical Trials Registration.NCT00458393.


Asunto(s)
Fármacos Anti-VIH/farmacología , Farmacorresistencia Viral , Infecciones por VIH/prevención & control , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , Adenina/administración & dosificación , Adenina/análogos & derivados , Adenina/uso terapéutico , Fármacos Anti-VIH/administración & dosificación , Desoxicitidina/administración & dosificación , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapéutico , Emtricitabina , Femenino , Genotipo , VIH-1/genética , Homosexualidad Masculina , Humanos , Masculino , Mutación , Organofosfonatos/administración & dosificación , Organofosfonatos/uso terapéutico , ARN Viral/genética , Tenofovir , Personas Transgénero , Carga Viral
2.
Proc Natl Acad Sci U S A ; 107(52): 22722-7, 2010 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-21149696

RESUMEN

Plant vascular networks are central to botanical form, function, and diversity. Here, we develop a theory for plant network scaling that is based on optimal space filling by the vascular system along with trade-offs between hydraulic safety and efficiency. Including these evolutionary drivers leads to predictions for sap flow, the taper of the radii of xylem conduits from trunk to terminal twig, and how the frequency of xylem conduits varies with conduit radius. To test our predictions, we use comprehensive empirical measurements of maple, oak, and pine trees and complementary literature data that we obtained for a wide range of tree species. This robust intra- and interspecific assessment of our botanical network model indicates that the central tendency of observed scaling properties supports our predictions much better than the West, Brown, and Enquist (WBE) or pipe models. Consequently, our model is a more accurate description of vascular architecture than what is given by existing network models and should be used as a baseline to understand and to predict the scaling of individual plants to whole forests. In addition, our model is flexible enough to allow the quantification of species variation around rules for network design. These results suggest that the evolutionary drivers that we propose have been fundamental in determining how physiological processes scale within and across plant species.


Asunto(s)
Modelos Biológicos , Transpiración de Plantas/fisiología , Haz Vascular de Plantas/fisiología , Agua/metabolismo , Acer/fisiología , Algoritmos , Evolución Biológica , Transporte Biológico , Pinus/fisiología , Haz Vascular de Plantas/anatomía & histología , Quercus/fisiología , Especificidad de la Especie , Xilema/anatomía & histología , Xilema/fisiología
3.
Nat Genet ; 29(2): 194-200, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11586301

RESUMEN

Expressed-sequence tag (EST) maps are an adjunct to sequence-based analytical methods of gene detection and localization for those species for which such data are available, and provide anchors for high-density homology and orthology mapping in species for which large-scale sequencing has yet to be done. Species for which radiation hybrid-based transcript maps have been established include human, rat, mouse, dog, cat and zebrafish. We have established a comprehensive first-generation-placement radiation hybrid map of the mouse consisting of 5,904 mapped markers (3,993 ESTs and 1,911 sequence-tagged sites (STSs)). The mapped ESTs, which often originate from small-EST clusters, are enriched for genes expressed during early mouse embryogenesis and are probably different from those localized in humans. We have confirmed by in situ hybridization that even singleton ESTs, which are usually not retained for mapping studies, may represent bona fide transcribed sequences. Our studies on mouse chromosomes 12 and 14 orthologous to human chromosome 14 show the power of our radiation hybrid map as a predictive tool for orthology mapping in humans.


Asunto(s)
Genoma , Células Híbridas/efectos de la radiación , ARN Mensajero/genética , Animales , Mapeo Cromosómico , Etiquetas de Secuencia Expresada , Hibridación in Situ , Ratones
4.
Acta Psychiatr Scand ; 123(1): 12-20, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20712828

RESUMEN

OBJECTIVE: The experience sampling method (ESM) represents a valuable way of assessing clinical phenomena in real world settings and across time. Despite its theoretical advantages, using this methodology in psychiatric populations is challenging. This paper acts as a guide to researchers wishing to employ this approach when investigating mental illness. METHOD: The contents represent the opinions of researchers around the United Kingdom and the Netherlands who are experienced at using the ESM. RESULTS: In ESM studies, participants are required to fill in questions about their current thoughts, feelings and experiences when prompted by an electronic device (e.g. a wristwatch, PDA). Entries are typically made at fixed or random intervals over 6 days. This article outlines how to design and validate an ESM diary. We then discuss which sampling procedure to use and how to increase compliance through effective briefing and telephone sessions. Debriefing, data management and analytical issues are considered, before suggestions for future clinical uses of the ESM are made. CONCLUSION: The last decade has seen an increase in the number of studies employing the ESM in clinical research. Further research is needed to examine the optimal equipment and procedure for different clinical groups.


Asunto(s)
Investigación Conductal , Entrevista Psicológica/métodos , Trastornos Mentales/psicología , Enfermos Mentales/psicología , Proyectos de Investigación/normas , Investigación Conductal/métodos , Investigación Conductal/organización & administración , Protocolos Clínicos , Metodologías Computacionales , Adhesión a Directriz , Guías como Asunto , Humanos , Países Bajos , Selección de Paciente , Muestreo , Medio Social , Reino Unido
5.
Cytopathology ; 22(2): 121-9, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20482715

RESUMEN

OBJECTIVES: To examine temporal trends in the use of vault cytology tests in primary and secondary care and the demographics of those women tested. METHODS: Retrospective analysis of routinely collected data concerning women who had a vault cytology test processed during a 10-year period (1 April 1995 to 31 March 2005) at Birmingham Women's NHS Foundation Trust. RESULTS: A total of 8457 vault cytology tests from 3164 women (range 1-17 tests, median = 2) were processed, representing approximately 2% of the cervical cytology workload of the Department of Cytopathology at Birmingham Women's Hospital. There was a significant reduction in annual numbers processed (Pearson correlation -0.958, P < 0.001). Significant abnormalities (mild dyskaryosis or worse) were detected in 4.5%, with malignancy being detected in <0.1%. The unsatisfactory cytology test rate was 10.7% overall. There was a reduction in the numbers of vault cytology tests coming from the community, hospital outpatient clinics and operating theatres over time (χ(2) for linear trend = 139.53, 9 d.f., P < 0.0001). Tests originating from community settings had the lowest disease detection rates: no malignancies and only two severe abnormalities were detected from almost 4000 primary care samples; abnormal results represented 2.8% (n = 113), of which the majority (n = 73) were borderline results. All cancers (n = 8) were detected in samples taken in gynaecology and colposcopy clinics. CONCLUSIONS: Vault cytology test usage appears to be reducing, particularly from outpatient clinics and primary care. Community detection rates are very low. Further research is required to establish the true costs and benefits of vaginal vault cytology.


Asunto(s)
Vagina/patología , Frotis Vaginal/estadística & datos numéricos , Frotis Vaginal/tendencias , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Colposcopía/estadística & datos numéricos , Colposcopía/tendencias , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Reino Unido/epidemiología , Neoplasias del Cuello Uterino/patología
6.
Bone ; 131: 115111, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31726107

RESUMEN

As bone is used in a dynamic mechanical environment, understanding the structural origins of its time-dependent mechanical behaviour - and the alterations in metabolic bone disease - is of interest. However, at the scale of the mineralized fibrillar matrix (nanometre-level), the nature of the strain-rate dependent mechanics is incompletely understood. Here, we investigate the fibrillar- and mineral-deformation behaviour in a murine model of Cushing's syndrome, used to understand steroid induced osteoporosis, using synchrotron small- and wide-angle scattering/diffraction combined with in situ tensile testing at three strain rates ranging from 10-4 to 10-1 s-1. We find that the effective fibril- and mineral-modulus and fibrillar-reorientation show no significant increase with strain-rate in osteoporotic bone, but increase significantly in normal (wild-type) bone. By applying a fibril-lamellar two-level structural model of bone matrix deformation to fit the results, we obtain indications that altered collagen-mineral interactions at the nanoscale - along with altered fibrillar orientation distributions - may be the underlying reason for this altered strain-rate sensitivity. Our results suggest that an altered strain-rate sensitivity of the bone matrix in osteoporosis may be one of the contributing factors to reduced mechanical competence in such metabolic bone disorders, and that increasing this sensitivity may improve biomechanical performance.


Asunto(s)
Nanoestructuras , Osteoporosis , Animales , Matriz Ósea , Huesos , Ratones , Osteoporosis/inducido químicamente , Esteroides , Estrés Mecánico
7.
Acta Biomater ; 76: 295-307, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29902593

RESUMEN

Glucocorticoid-induced osteoporosis (GIOP) is a major secondary form of osteoporosis, with the fracture risk significantly elevated - at similar levels of bone mineral density - in patients taking glucocorticoids compared with non-users. The adverse bone structural changes at multiple hierarchical levels in GIOP, and their mechanistic consequences leading to reduced load-bearing capacity, are not clearly understood. Here we combine experimental X-ray nanoscale mechanical imaging with analytical modelling of the bone matrix mechanics to determine mechanisms causing bone material quality deterioration during development of GIOP. In situ synchrotron small-angle X-ray diffraction combined with tensile testing was used to measure nanoscale deformation mechanisms in a murine model of GIOP, due to a corticotrophin-releasing hormone promoter mutation, at multiple ages (8-, 12-, 24- and 36 weeks), complemented by quantitative micro-computed tomography and backscattered electron imaging to determine mineral concentrations. We develop a two-level hierarchical model of the bone matrix (mineralized fibril and lamella) to predict fibrillar mechanical response as a function of architectural parameters of the mineralized matrix. The fibrillar elastic modulus of GIOP-bone is lower than healthy bone throughout development, and nearly constant in time, in contrast to the progressively increasing stiffness in healthy bone. The lower mineral platelet aspect ratio value for GIOP compared to healthy bone in the multiscale model can explain the fibrillar deformation. Consistent with this result, independent measurement of mineral platelet lengths from wide-angle X-ray diffraction finds a shorter mineral platelet length in GIOP. Our results show how lowered mineralization combined with altered mineral nanostructure in GIOP leads to lowered mechanical competence. SIGNIFICANCE STATEMENT: Increased fragility in musculoskeletal disorders like osteoporosis are believed to arise due to alterations in bone structure at multiple length-scales from the organ down to the supramolecular-level, where collagen molecules and elongated mineral nanoparticles form stiff fibrils. However, the nature of these molecular-level alterations are not known. Here we used X-ray scattering to determine both how bone fibrils deform in secondary osteoporosis, as well as how the fibril orientation and mineral nanoparticle structure changes. We found that osteoporotic fibrils become less stiff both because the mineral nanoparticles became shorter and less efficient at transferring load from collagen, and because the fibrils are more randomly oriented. These results will help in the design of new composite musculoskeletal implants for bone repair.


Asunto(s)
Densidad Ósea/efectos de los fármacos , Matriz Ósea/metabolismo , Glucocorticoides/efectos adversos , Osteoporosis , Animales , Matriz Ósea/patología , Modelos Animales de Enfermedad , Femenino , Glucocorticoides/farmacología , Humanos , Ratones , Ratones Transgénicos , Osteoporosis/inducido químicamente , Osteoporosis/metabolismo , Osteoporosis/patología
8.
PLoS One ; 12(9): e0183015, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28957353

RESUMEN

Implicit intergroup bias emerges early in development, are typically pro-ingroup, and remain stable across the lifespan. Such findings have been interpreted in terms of an automatic ingroup bias similar to what is observed with minimal groups paradigms. These studies are typically conducted with groups of high cultural standing (e.g., Caucasians in North America and Europe). Research conducted among culturally lower status groups (e.g., African-Americans, Latino-Americans) reveals a notable absence of an implicit ingroup bias. Understanding the environmental factors that contribute to the absence of an implicit ingroup bias among people from culturally lower status groups is critical for advancing theories of implicit intergroup cognition. The present study aimed to elucidate the factors that shape racial group bias among African-American children and young adults by examining their relationship with age, school composition (predominantly Black schools or racially mixed schools), parental racial attitudes and socialization messages among African-American children (N = 86) and young adults (N = 130). Age, school-type and parents' racial socialization messages were all found to be related to the strength of pro-Black (ingroup) bias. We also found that relationships between implicit and explicit bias and frequency of parents' racial socialization messages depended on the type of school participants attended. Our results highlight the importance of considering environmental factors in shaping the magnitude and direction of implicit and explicit race bias among African-Americans rather than treating them as a monolithic group.


Asunto(s)
Negro o Afroamericano , Racismo , Niño , Femenino , Humanos , Masculino , Padres , Instituciones Académicas , Universidades , Adulto Joven
9.
Stroke ; 37(6): 1385-90, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16675738

RESUMEN

BACKGROUND AND PURPOSE: Phosphodiesterase 4D (PDE4D) underlies the STRK1 linkage peak for stroke on chromosome 5q12 identified in Iceland. We tested association of 13 single-nucleotide polymorphisms (SNPs) and 1 microsatellite in a nested case-control sample of elderly white women (>65 years of age) from the Study of Osteoporotic Fractures (SOF) in the United States. METHODS: The genotypes of 248 women who experienced an incident ischemic stroke during an average of 5.4 years of follow-up were compared with 560 controls. RESULTS: Marginal associations with stroke (P<0.10) were found for 3 polymorphisms. Stratification of the population by hypertension markedly strengthened the association. SNPs 9 (hazard ratio [HR], 0.48; 95% CI, 0.26 to 0.91), 42 (HR, 1.73; 95% CI, 1.10 to 2.70), 219 (HR, 1.73; 95% CI, 1.13 to 2.64), and 220 (HR, 1.56; 95% CI, 1.05 to 2.32) showed significant association with stroke (P<0.05) under a dominant model in subjects without hypertension at baseline, and SNP 175 was significantly associated with stroke under an additive model (HR, 0.76; 95% CI, 0.59 to 0.98) in subjects with hypertension. Furthermore, the microsatellite AC008818-1 showed association with stroke only in the nonhypertensive subjects. Based on results in Iceland, specific haplotypes were tested in SOF, and stratification by hypertension also affected these association results. CONCLUSIONS: These data are consistent with an association of the PDE4D gene with stroke in a non-Icelandic sample and suggest an effect of hypertension status.


Asunto(s)
3',5'-AMP Cíclico Fosfodiesterasas/genética , Isquemia Encefálica/complicaciones , Hipertensión/complicaciones , Polimorfismo Genético , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/genética , Anciano , Alelos , Estudios de Casos y Controles , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 3 , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4 , Femenino , Haplotipos , Humanos , Islandia/etnología , Repeticiones de Microsatélite , Polimorfismo de Nucleótido Simple , Estados Unidos
10.
Biotechnol Prog ; 22(5): 1335-45, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17022672

RESUMEN

With the applications of DNA vaccines extending from infectious diseases to cancer, achieving the most efficient, reproducible, robust, scalable, and economical production of clinical grade plasmid DNA is paramount to the medical and commercial success of this novel vaccination paradigm. A first generation production process based on the cultivation of Escherichia coli in a chemically defined medium, employing a fed-batch strategy, delivered reasonable volumetric productivities (500-750 mg/L) and proved to perform very well across a wide range of E. coli constructs upon scale-up at industrial scale. However, the presence of monosodium glutamate (MSG) in the formulation of the cultivation and feed solution was found to be a potential cause of process variability. The development of a second generation process, based on a defined cultivation medium and feed solution excluding MSG, was undertaken. Optimization studies, employing a plasmid coding for the HIV gag protein, resulted in cultivation conditions that supported volumetric plasmid titers in excess of 1.2 g/L, while achieving specific yields ranging from 25 to 32 microg plasmid DNA/mg of dry cell weight. When used for the production of clinical supplies, this novel process demonstrated applicability to two other constructs upon scale-up in 2,000-L bioreactors. This second generation process proved to be scalable, robust, and highly productive.


Asunto(s)
Reactores Biológicos , Biotecnología/métodos , ADN/química , Plásmidos/metabolismo , Separación Celular , Cromatografía Líquida de Alta Presión , Medios de Cultivo/metabolismo , Escherichia coli/metabolismo , Citometría de Flujo , Glicerol/química , Concentración de Iones de Hidrógeno , Espectrometría de Fluorescencia , Factores de Tiempo , Vacunas de ADN/química
11.
Eur J Pain ; 20(4): 499-511, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26424514

RESUMEN

BACKGROUND AND OBJECTIVE: Spinal cord stimulation (SCS) is believed to exert supraspinal effects; however, these mechanisms are still far from fully elucidated. This systematic review aims to assess existing neurophysiological and functional neuroimaging literature to reveal current knowledge regarding the effects of SCS for chronic neuropathic pain on brain activity, to identify gaps in knowledge, and to suggest directions for future research. DATABASES AND DATA TREATMENT: Electronic databases and hand-search of reference lists were employed to identify publications investigating brain activity associated with SCS in patients with chronic neuropathic pain, using neurophysiological and functional neuroimaging techniques (fMRI, PET, MEG, EEG). Studies investigating patients with SCS for chronic neuropathic pain and studying brain activity related to SCS were included. Demographic data (age, gender), study factors (imaging modality, patient diagnoses, pain area, duration of SCS at recording, stimulus used) and brain areas activated were extracted from the included studies. RESULTS: Twenty-four studies were included. Thirteen studies used neuroelectrical imaging techniques, eight studies used haemodynamic imaging techniques, two studies employed both neuroelectrical and haemodynamic techniques separately, and one study investigated cerebral neurobiology. CONCLUSIONS: The limited available evidence regarding supraspinal mechanisms of SCS does not allow us to develop any conclusive theories. However, the studies included appear to show an inhibitory effect of SCS on somatosensory evoked potentials, as well as identifying the thalamus and anterior cingulate cortex as potential mediators of the pain experience. The lack of substantial evidence in this area highlights the need for large-scale controlled studies of this kind.


Asunto(s)
Encéfalo/fisiopatología , Dolor Crónico/fisiopatología , Dolor Crónico/terapia , Neuralgia/fisiopatología , Neuralgia/terapia , Estimulación de la Médula Espinal , Adulto , Anciano , Electroencefalografía , Potenciales Evocados Somatosensoriales , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad
12.
Bone ; 84: 15-24, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26657825

RESUMEN

A serious adverse clinical effect of glucocorticoid steroid treatment is secondary osteoporosis, enhancing fracture risk in bone. This rapid increase in bone fracture risk is largely independent of bone loss (quantity), and must therefore arise from degradation of the quality of the bone matrix at the micro- and nanoscale. However, we lack an understanding of both the specific alterations in bone quality n steroid-induced osteoporosis as well as the mechanistic effects of these changes. Here we demonstrate alterations in the nanostructural parameters of the mineralized fibrillar collagen matrix, which affect bone quality, and develop a model linking these to increased fracture risk in glucocorticoid induced osteoporosis. Using a mouse model with an N-ethyl-N-nitrosourea (ENU)-induced corticotrophin releasing hormone promoter mutation (Crh(-120/+)) that developed hypercorticosteronaemia and osteoporosis, we utilized in situ mechanical testing with small angle X-ray diffraction, synchrotron micro-computed tomography and quantitative backscattered electron imaging to link altered nano- and microscale deformation mechanisms in the bone matrix to abnormal macroscopic mechanics. We measure the deformation of the mineralized collagen fibrils, and the nano-mechanical parameters including effective fibril modulus and fibril to tissue strain ratio. A significant reduction (51%) of fibril modulus was found in Crh(-120/+) mice. We also find a much larger fibril strain/tissue strain ratio in Crh(-120/+) mice (~1.5) compared to the wild-type mice (~0.5), indicative of a lowered mechanical competence at the nanoscale. Synchrotron microCT show a disruption of intracortical architecture, possibly linked to osteocytic osteolysis. These findings provide a clear quantitative demonstration of how bone quality changes increase macroscopic fragility in secondary osteoporosis.


Asunto(s)
Matriz Ósea/patología , Matriz Ósea/fisiopatología , Fracturas Óseas/fisiopatología , Osteoporosis/inducido químicamente , Osteoporosis/fisiopatología , Esteroides/efectos adversos , Animales , Matriz Ósea/diagnóstico por imagen , Femenino , Fémur/patología , Fémur/fisiopatología , Fémur/ultraestructura , Fracturas Óseas/diagnóstico por imagen , Fracturas Óseas/patología , Ratones Endogámicos C57BL , Osteoporosis/diagnóstico por imagen , Sincrotrones , Resistencia a la Tracción , Microtomografía por Rayos X
13.
Biotechnol Prog ; 21(4): 1038-47, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16080681

RESUMEN

For many microbial fermentation processes, the inoculum train can have a substantial impact on process performance in terms of productivity, profitability, and process control. In general, it is understood that a well-characterized and flexible inoculum train is essential for future scale-up and implementation of the process in a pilot plant or manufacturing setting. A fermentation process utilizing E. coli DH5 for the production of plasmid DNA carrying the HIV gag gene for use as a vaccine is currently under development in our laboratory. As part of the development effort, we evaluated inoculum train schemes that incorporate one, two, or three stages. In addition, we investigated the effect of inoculum viable-cell concentrations, either thawed or actively growing, over a wide range (from 2.5 x 10(4) to 1.0 x 10(8) viable cells/mL or approximately 0.001% to 4% of final working volume). The various inoculum trains were evaluated in terms of final plasmid yield, process time, reproducibility, robustness, and feasibility at large scale. The results of these studies show that final plasmid yield remained in the desired range, despite the number of stages or inoculation viable-cell concentrations comprising the inoculum train. On the basis of these observations and because it established a large database, the first part of these investigations supports an exceptional flexibility in the design of scalable inoculum trains for this DNA vaccine process. This work also highlighted that a slightly higher level of process reproducibility, as measured by the time for the culture to reach mid-exponential growth, was observed when using actively growing versus frozen cells. It also demonstrated the existence of a viable-cell concentration threshold for the one-stage process, since we observed that inoculation of the production stage with very low amounts of viable cells from a frozen source could lead to increased process sensitivity to external factors such as variation in the quality of the raw materials used in the medium formulation. However, our analysis indicates that, despite this slight disadvantage, a one-stage inoculum train was a viable option in many situations, especially if the inoculation viable-cell concentration was kept above 4.8 x 10(6) viable cells/mL. Because it leads to a reduction in process steps and eliminates some capital investments (i.e., inoculum fermenter), when feasible a one-stage process configuration will positively impact process economics.


Asunto(s)
Escherichia coli/genética , Microbiología Industrial/métodos , Vacunas de ADN , Reactores Biológicos , Medios de Cultivo/química , Medios de Cultivo/farmacología , Detergentes/química , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Fermentación , Productos del Gen gag/genética , Microbiología Industrial/instrumentación , Plásmidos/genética
14.
J Med Genet ; 40(4): 249-56, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12676894

RESUMEN

Imprinted gene(s) on human chromosome 7q32-qter have been postulated to be involved in intrauterine growth restriction associated with Silver-Russell syndrome (SRS) as 7-10% of patients have mUPD(7). Three imprinted genes, MEST, MESTIT1, and COPG2IT1 on chromosome 7q32, are unlikely to cause SRS since epigenetic and sequence mutation analyses have not shown any changes. One hundred kilobases proximal to MEST lies a group of four carboxypeptidase A (CPA) genes. Since most imprinted genes are found in clusters, this study focuses on analysing these CPAs for imprinting effects based on their proximity to an established imprinted domain. Firstly, a replication timing study across 7q32 showed that an extensive genomic region including the CPAs, MEST, MESTIT1, and COPG2IT1 replicates asynchronously. Subsequently, SNP analysis by sequencing RT-PCR products of CPA1, CPA2, CPA4, and CPA5 indicated preferential expression of CPA4. Pyrosequencing was used as a quantitative approach, which confirmed predominantly preferential expression of the maternal allele and biallelic expression in brain. CPA5 expression levels were too low to allow reliable evaluation of allelic expression, while CPA1 and CPA2 both showed biallelic expression. CPA4 was the only gene from this family in which an imprinting effect was shown despite the location of this family of genes next to an imprinted cluster. As CPA4 has a potential role in cell proliferation and differentiation, two preferentially expressed copies in mUPD patients with SRS syndrome would result in excess expression and could alter the growth profiles of these subjects and give rise to intrauterine growth restriction.


Asunto(s)
Carboxipeptidasas/genética , Cromosomas Humanos Par 7/genética , Retardo del Crecimiento Fetal/genética , Impresión Genómica , Familia de Multigenes/genética , Empalme Alternativo , Carboxipeptidasas A , ADN/química , ADN/genética , Análisis Mutacional de ADN , ADN Complementario/química , ADN Complementario/genética , Femenino , Retardo del Crecimiento Fetal/enzimología , Retardo del Crecimiento Fetal/patología , Regulación Enzimológica de la Expresión Génica , Genes/genética , Humanos , Datos de Secuencia Molecular , Polimorfismo de Nucleótido Simple/genética , Embarazo , Análisis de Secuencia de ADN , Síndrome
15.
Physiol Genomics ; 3(3): 145-8, 2000 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-11015609

RESUMEN

Several microsatellite genotyping panel sets have been developed that are polymorphic between C57BL/6J and CAST/Ei mice, or C57BL/6J and DBA/2J. One set of markers for each strain pair has an intermarker distance of approximately 20 cM, and a second set has an intermarker distance of 5 cM. The 20-cM set contains 105 markers for C57BL/6J x DBA/2J and 108 for C57BL/6J x CAST/Ei, divided into 13 panels. Each 5-cM set includes 350 markers arranged into 45 panels. A panel contains a number of primer pairs whose fluorescently labeled PCR products can be pooled together and separated on one lane of a polyacrylamide gel. The sets are arranged by the size of the PCR product and by the type of fluorescent dye; 5-cM sets are also arranged by chromosomal region. The 20-cM sets are most useful for full-genome scans, the 5-cM sets are useful for full-genome and/or for region-specific chromosome screens. Both sets were proven as useful tools for speed congenic development, quantitative trait loci (QTL) analysis and physical mapping. These panel sets provide a throughput of 1,536-2,304 mouse genotypes daily per one gel-based system. Whole genome scans of one animal require 13 or 48 gel lanes, with 20 cM or 5 cM density, respectively.


Asunto(s)
Cruzamientos Genéticos , Repeticiones de Microsatélite/genética , Animales , Mapeo Cromosómico , Cromosomas/genética , ADN/genética , Femenino , Genotipo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos DBA
16.
Inflamm Bowel Dis ; 5(4): 271-8, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10579120

RESUMEN

Chronic inflammatory bowel disease (IBD) presents as two major clinical forms, Crohn's disease (CD) and ulcerative colitis (UC). Genetic epidemiological studies and animal models suggest that inherited factors play significant roles in the susceptibility to both forms of IBD. From four genome-wide scans, putative susceptibility loci on chromosome 16 (IBD1 for CD), and on chromosomes 1, 3, 4, 6, 7, 10, and 12 for IBD, have been identified. Several other groups, including ours, have confirmed linkage to the loci on chromosomes 12 and 16. The aim of this study is to identify other potential susceptibility loci for CD with a genome-wide search approach. In our sample of 222 individuals from 46 families (20 Jewish and 26 non-Jewish), with a total of 65 sibpairs diagnosed with CD, we observed a novel locus with suggestive linkage [multipoint logarithm of the odds score (Mlod) > 2] at chromosome 14q11.2 (Mlod = 2.8, p = 0.0002). In addition, suggestive linkage was observed in our Jewish families at chromosome 17q21-q23 (Mlod = 2.1, p = 0.01) and chromosome 5q33-q35 (Mlod = 2.2, p = 0.0003). The syntenic regions of the latter locus are mapped within two putative loci on mouse chromosomes 11 and 18, which were identified in a mouse IBD model induced by dextran sulfate sodium (29). Our preliminary results provide potential evidence for several susceptibility loci contributing to the risk of CD. The observation of man-mouse synteny may accelerate the identification of CD susceptibility gene(s) on human chromosome 5.


Asunto(s)
Enfermedad de Crohn/genética , Predisposición Genética a la Enfermedad/genética , Pruebas Genéticas/métodos , Genoma Humano , Mapeo Cromosómico , Enfermedad de Crohn/epidemiología , Femenino , Ligamiento Genético , Marcadores Genéticos , Predisposición Genética a la Enfermedad/epidemiología , Genotipo , Humanos , Masculino , Sitios Menores de Histocompatibilidad , Sensibilidad y Especificidad
17.
Brain Res ; 347(2): 274-83, 1985 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-4063809

RESUMEN

The alpha-bungarotoxin (BGT) binding protein from rat brain has been purified and its polypeptide chain composition has been examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Polypeptide chains with Mrs of 55,000, 53,500 and 49,000 have been identified as constituents of the protein. The affinity ligand [3H]maleimidobenzyl trimethylammonium bromide ([3H]MBTA), used to identify the ligand binding site on neuromuscular junction acetylcholine receptors (NMJ AChRs), binds to the 55,000 dalton polypeptide chain. Using a technique where ligands are bound to the protein while the protein is immobilized on alpha-cobratoxin-Sepharose 4B, it was established that the brain BGT binding protein, like NMJ AChRs, possesses two binding sites for BGT. These experiments reinforce previous evidence that the brain BGT binding protein is closely related but not identical to NMJ AChRs.


Asunto(s)
Química Encefálica , Bungarotoxinas/metabolismo , Receptores Colinérgicos/aislamiento & purificación , Receptores Nicotínicos , Animales , Sitios de Unión/efectos de los fármacos , Química Encefálica/efectos de los fármacos , Proteínas Portadoras/aislamiento & purificación , Proteínas Neurotóxicas de Elápidos/metabolismo , Electroforesis en Gel de Poliacrilamida , Peso Molecular , Péptidos/análisis , Compuestos de Amonio Cuaternario/metabolismo , Ratas , Receptor Nicotínico de Acetilcolina alfa 7
18.
Poult Sci ; 63(7): 1444-5, 1984 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-6473258

RESUMEN

The seminal plasma from individual ejaculates of 13 males of a line of chickens selected for increased duration of fertility of frozen-thawed semen for 7 generations and 12 males of the control line were analyzed for proteins. The mean +/- SE total seminal plasma protein of the selected and control lines were 8.74 +/- .55 micrograms and 7.52 +/- .92 micrograms/microliter seminal plasma (P greater than .05). Crossed immunoelectrophoretic analysis of the seminal plasma generated, in general, 11 precipitant peaks in both lines. The protein corresponding to peak 11 of the electrophoretic pattern was significantly (P less than .01) higher in the selected line than in the control line, the mean +/- SE being 1.80 +/- .21 and .85 +/- .19 micrograms/microliter seminal plasma.


Asunto(s)
Pollos/genética , Fertilidad , Proteínas de Secreción Prostática , Proteínas/análisis , Preservación de Semen/veterinaria , Semen/fisiología , Animales , Congelación , Inmunoelectroforesis Bidimensional , Masculino , Semen/análisis , Proteínas de Plasma Seminal
19.
Ann Acad Med Singap ; 23(2): 244-8, 1994 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8080225

RESUMEN

Patients with haematological diseases do not have ready access to hospice services in South Australia. They remain in close contact with a specialist haematology or oncology unit, and are more likely than are patients with solid tumours to receive intensive therapy during a terminal admission. The course of the final month of life was compared for three groups of patients suffering from colorectal cancer, non-Hodgkins lymphoma and acute leukaemia by a review of hospital records. All leukaemia patients died in hospital and few received a palliative care consultation. Measures of symptom control and quality of life are not recorded for these patients. It seems probable that adults with acute leukaemia will continue to die in hospital. Some of the lessons learnt from hospice practice may be appropriately applied in hospital for those patients.


Asunto(s)
Neoplasias Colorrectales/psicología , Neoplasias Colorrectales/terapia , Investigación sobre Servicios de Salud , Leucemia/psicología , Leucemia/terapia , Linfoma no Hodgkin/psicología , Linfoma no Hodgkin/terapia , Pautas de la Práctica en Medicina/organización & administración , Calidad de Vida , Cuidado Terminal/organización & administración , Enfermedad Aguda , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Hospitales para Enfermos Terminales/organización & administración , Hospitalización , Humanos , Tiempo de Internación , Masculino , Auditoría Médica , Persona de Mediana Edad , Modelos Organizacionales , Cuidado Terminal/psicología
20.
Stud Health Technol Inform ; 81: 69-74, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11317820

RESUMEN

To provide data for the design of virtual environments and teleoperated systems for surgery, it is necessary to measure tissue properties under both in vivo and ex vivo conditions. The former provides information about tissue behavior in its physiological state, while the latter can provide better control over experimental conditions. We have developed devices to measure tissue properties under extension and indentation, as well as to record instrument-tissue interaction forces. We are creating a web database of data recorded from porcine abdominal tissues.


Asunto(s)
Instrumentos Quirúrgicos , Interfaz Usuario-Computador , Abdomen/cirugía , Animales , Simulación por Computador , Bases de Datos como Asunto , Internet , Laparoscopios , Porcinos
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