Home About us Contact
|
Home About us Contact | ||
|
|
||
Long-term Analysis (long-term + analysis)
Selected AbstractsPlasma lipid concentrations after 1.5 years of exposure to nevirapine or efavirenz together with stavudine and lamivudineHIV MEDICINE, Issue 6 2006F Van Leth Objectives To assess long-term changes in lipids and lipoproteins concentrations associated with exposure to non-nucleoside reverse transcriptase inhibitors. Methods Long-term analysis of plasma lipid concentrations was performed in patients starting first-line antiretroviral therapy with stavudine (d4T) and lamivudine, and either nevirapine or efavirenz. Results Concentrations of total cholesterol, low-density lipoprotein cholesterol and triglycerides continued to increase, while high-density lipoprotein cholesterol showed a slight decrease compared with earlier reported increases after 48 weeks. Conclusions Changes in body fat distribution expected to occur with continued exposure to d4T could offer a potential explanation for these findings. [source] Temporal variation in the genetic structure of host-associated populations of the small ermine moth Yponomeuta padellus (Lepidoptera, Yponomeutidae)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2000LÉON E. L. RAIJMANN Temporal changes in allele frequencies were studied in host-associated populations of the small ermine moth Yponomeuta padellus. At one site, populations from three host plants (Sorbus aucuparia, Amelanchier larnarckii, and Crataegus spp.) were sampled annually during a four-year-period and analysed with 20 polymorphic allozyme markers. At two other sites, allele frequencies at 5- 6 enzyme loci of Y. padellus populations from two different host plants were also tested for consistency over a 13-year-pcriod. Significant allele frequency changes occurred in the short-term analysis, whereas allele frequencies remained relatively stable through time in the long-term analyses. Furthermore, allele frequencies of Y. padellus populations from Crataegus spp. were relatively stable compared to the other host populations. The role of the agents responsible for the observed patterns is discussed. [source] One Hundred Fifty Years of Change in Forest Bird Breeding Habitat: Estimates of Species DistributionsCONSERVATION BIOLOGY, Issue 6 2005LISA A. SCHULTE aptitud del hábitat; ecología aviar; ecología de paisaje; planificación de conservación Abstract:,Evaluating bird population trends requires baseline data. In North America the earliest population data available are those from the late 1960s. Forest conditions in the northern Great Lake states (U.S.A.), however, have undergone succession since the region was originally cut over around the turn of the twentieth century, and it is expected that bird populations have undergone concomitant change. We propose pre-Euro-American settlement as an alternative baseline for assessing changes in bird populations. We evaluated the amount, quality, and distribution of breeding bird habitat during the mid-1800s and early 1990s for three forest birds: the Pine Warbler (Dendroica pinus), Blackburnian Warbler (D. fusca), and Black-throated Green Warbler (D. virens). We constructed models of bird and habitat relationships based on literature review and regional data sets of bird abundance and applied these models to widely available vegetation data. Original public-land survey records represented historical habitat conditions, and a combination of forest inventory and national land-cover data represented current conditions. We assessed model robustness by comparing current habitat distribution to actual breeding bird locations from the Wisconsin Breeding Bird Atlas. The model showed little change in the overall amount of Pine Warbler habitat, whereas both the Blackburnian Warber and the Black-throated Green Warbler have experienced substantial habitat losses. For the species we examined, habitat quality has degraded since presettlement and the spatial distribution of habitat shifted among ecoregions, with range expansion accompanying forest incursion into previously open habitats or the replacement of native forests with pine plantations. Sources of habitat loss and degradation include loss of conifers and loss of large trees. Using widely available data sources in a habitat suitability model framework, our method provides a long-term analysis of change in bird habitat and a presettlement baseline for assessing current conservation priority. Resumen:,La evaluación de tendencias de las poblaciones de aves requiere de datos de referencia. En Norte América, los primeros datos disponibles de poblaciones son del final de la década de 1960. Sin embargo, las condiciones de los bosques en los estados de los Grandes Lagos (E.U.A.) han experimentado sucesión desde que la región fue talada en los inicios del siglo veinte, y se espera que las poblaciones de aves hayan experimentado cambios concomitantes. Proponemos que se considere al período previo a la colonización euro americana como referencia alternativa para evaluar los cambios en las poblaciones de aves. Evaluamos la cantidad, calidad y distribución del hábitat para reproducción de tres especies de aves de bosque (Dendroica pinus, D. fusca y D. virens) a mediados del siglo XIX e inicios del XX. Construimos modelos de las relaciones entre las aves y el hábitat con base en la literatura y conjuntos de datos de abundancia de aves y los aplicamos a los datos de vegetación ampliamente disponibles. Los registros topográficos de tierras públicas originales representaron las condiciones históricas del hábitat, y una combinación de datos del inventario forestal y de cobertura de suelo representaron las condiciones actuales. Evaluamos la robustez del modelo mediante la comparación de la distribución de hábitat actual con sitios de reproducción de aves registrados en el Wisconsin Breeding Bird Atlas. El modelo mostró poco cambio en la cantidad total de hábitat de Dendroica pinus, mientras que tanto D. fusca como D. virens han experimentado pérdidas sustanciales de hábitat. Para las especies examinadas, la calidad del hábitat se ha degradado desde antes de la colonización y la distribución espacial del hábitat cambió entre ecoregiones, con la expansión del rango acompañando la incursión de bosques en hábitats anteriormente abiertos o el reemplazo de bosques nativos con plantaciones de pinos. Las fuentes de pérdida y degradación de hábitats incluyen la pérdida de coníferas y de árboles grandes. Mediante la utilización de fuentes de datos ampliamente disponibles en un modelo de aptitud de hábitat, nuestro método proporciona un análisis a largo plazo de los cambios en el hábitat de aves y una referencia precolonización para evaluar prioridades de conservación actuales. [source] The Use of Phosphatidylcholine for Correction of Lower Lid Bulging Due to Prominent Fat PadsDERMATOLOGIC SURGERY, Issue 4 2001Patrícia Guedes Rittes MDArticle first published online: 20 DEC 200 Background. Patients with prominent periorbital fat pads often complain of having a persistent "tired" look and seek treatment from their dermatologist. Objective. A non-surgical treatment of fat pads. Methods. Thirty patients were treated for prominent lower eyelid fat pads with phosphatidylcholine injection. Pre- and posttreatment photographs were taken for long-term analysis. Results. A marked reduction of the lower eyelid fat pads was noted over the 2-year follow-up period. There were no recurrences. Conclusion. The injection of phosphatidylcholine (250 mg/5 ml) into the fat pads is a simple office procedure that may postpone or even substitute for lower eyelid blepharoplasty. [source] Femur window,a new approach to microcirculation of living bone in situJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2005N. Hansen-Algenstaedt Abstract Background: The processes of osteogenesis, bone remodelling, fracture repair and metastasis to bone are determined by complex sequential interactions involving cellular and microcirculatory parameters. Consequently studies targeting the analysis of microcirculatory parameters on such processes should mostly respect these complex conditions. However these conditions could not yet be achieved in vitro and therefore techniques that allow a long-term observation of functional and structural parameters of microcirculation in bone in vivo at a high spatial resolution are needed to monitor dynamic events, such as fracture healing, bone remodelling and tumor metastasis. Methods: We developed a bone chamber implant (femur window) for long-term intravital microscopy of pre-existing bone and its microcirculation at an orthotopic site in mice preserving the mechanical properties of bone. After bone chamber implantation vascular density, vessel diameter, vessel perfusion, vascular permeability and leukocyte-endothelial interactions (LEIs) in femoral bone tissue of c57-black mice (n = 11) were measured quantitatively over 12 days using intravital fluorescence microscopy. Furthermore a model for bone defect healing and bone metastasis in the femur window was tested. Results: Microvascular permeability and LEIs showed initially high values after chamber implantation followed by a significant decrease to a steady state at day 6 and 12, whereas structural parameters remained unaltered. Bone defect healing and tumor growth was observed over 12 and 90 days respectively. Conclusion: The new femur window design allows a long-term analysis of structural and functional properties of bone and its microcirculation quantitatively at a high spatial resolution. Altered functional parameters of microcirculation after surgical procedures and their time dependent return to a steady state underline the necessity of long-term observations to achieve unaltered microcirculatory parameters. Dissection of the complex interactions between bone and microcirculation enables us to evaluate physiological and pathological processes of bone and may give new insights especially in dynamic events e.g. fracture healing, bone remodeling and tumor metastasis. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Novel polymerase chain reaction primers for the specific detection of bacterial copper P-type ATPases gene sequences in environmental isolates and metagenomic DNALETTERS IN APPLIED MICROBIOLOGY, Issue 6 2010R. De la Iglesia Abstract Aims:, In the last decades, the worldwide increase in copper wastes release by industrial activities like mining has driven environmental metal contents to toxic levels. For this reason, the study of the biological copper-resistance mechanisms in natural environments is important. Therefore, an appropriate molecular tool for the detection and tracking of copper-resistance genes was developed. Methods and Results:, In this work, we designed a PCR primer pair to specifically detect copper P-type ATPases gene sequences. These PCR primers were tested in bacterial isolates and metagenomic DNA from intertidal marine environments impacted by copper pollution. As well, T-RFLP fingerprinting of these gene sequences was used to compare the genetic composition of such genes in microbial communities, in normal and copper-polluted coastal environments. New copper P-type ATPases gene sequences were found, and a high degree of change in the genetic composition because of copper exposure was also determined. Conclusions:, This PCR based method is useful to track bacterial copper-resistance gene sequences in the environment. Significance and Impact of the Study:, This study is the first to report the design and use of a PCR primer pair as a molecular marker to track bacterial copper-resistance determinants, providing an excellent tool for long-term analysis of environmental communities exposed to metal pollution. [source] Growth and long-term lung function in cystic fibrosis: A longitudinal study of patients diagnosed by neonatal screeningPEDIATRIC PULMONOLOGY, Issue 3 2009Baroukh Maurice Assael MD Abstract Objective So far there is no long-term analysis relating the achievement of growth milestones (such as prepubertal and pubertal take-off and peak velocity) to the course of respiratory function from childhood to adulthood in cystic fibrosis. This study was designed to evaluate linear growth and severity of lung disease, find a correlation between growth and disease severity throughout childhood. Patients One hundred sixty-three patients from one center were selected according to: diagnosis by neonatal screening, complete follow-up available (four height measurements/year) until the age of 20, respiratory tests available from the age of 5,6 years until adulthood, lung transplantation, or death. Disease was classified as mild or severe according to FEV1 (group 1 and group 2). A third group of patients (group 3) consisted of those who died or underwent lung transplantation before the age of 18. Methods Individual growth profiles were fitted with a seven-constant nonlinear growth function. A multivariate linear model was fitted, with gender and severity of disease as covariates, and age, height, and height velocity at growth milestones as dependent variables. Data were compared with those of the normal Italian population. Results Lung disease severity correlates with delayed prepubertal and pubertal growth milestones. Peak height velocities were significantly reduced in relation to the severity of the disease. Conclusions Patients with severe forms of cystic fibrosis exhibit reduced growth velocity values at an early age, before a clear decline in pulmonary function. Pediatr Pulmonol. 2009; 44:209,215. © 2009 Wiley-Liss, Inc. [source] The Effects of Smoking on Short-Term Quality of Life Outcomes in Sinus Surgery,THE LARYNGOSCOPE, Issue 12 2007Subinoy Das MD Abstract Objective: The purpose of this study was to prospectively compare the short-term benefit of endoscopic sinus surgery for smokers and nonsmokers using a disease specific, clinically validated, quality of life outcomes measure, the Sinonasal Outcomes Test-20 (SNOT-20). Study Design: Prospective clinical trial. Methods: A total of 235 patients were prospectively enrolled at a single tertiary academic center. Preoperative SNOT-20 scores and comprehensive demographic data were obtained. All patients underwent endoscopic sinus surgery under the supervision of the senior author. Preoperative SNOT-20 scores were compared to short-term postoperative SNOT-20 scores. Results: Short-term postoperative results were available for 221 patients for comparison. Preoperative SNOT-20 scores in 49 smokers (mean: 27.8) and 172 nonsmokers (mean: 26.2) were statistically similar. Both smokers and nonsmokers achieved a highly significant reduction in SNOT-20 scores at short-term follow-up evaluations. (P < .0005) Smokers achieved a greater reduction in SNOT-20 scores (mean difference: 22.1) at short-term follow-up compared to nonsmokers (mean difference: 16.1). This result was statistically significant (P < .044). Conclusions: This study confirms that smokers and nonsmokers achieve a highly significant short-term benefit from endoscopic sinus surgery using a clinically-validated symptom severity scale in a prospective study. Interestingly, smokers achieved a greater short-term benefit than nonsmokers did. This study calls into question the notion that current smokers are poorer candidates for endoscopic sinus surgery. Further prospective studies to confirm these results and provide long-term analysis should be performed. [source] Natural course of benign thyroid nodules in a moderately iodine-deficient areaCLINICAL ENDOCRINOLOGY, Issue 6 2006Murat Faik Erdogan Summary Objective, Few studies using ultrasonographic evaluation have addressed the natural course of benign thyroid nodules. In this study, we present the long-term analysis of benign, untreated thyroid nodules in a moderately iodine-deficient area. Design, We collected the retrospective data for 531 nodules in 420 patients followed by ultrasonography for a mean time period of 39·7 ± 27·8 months (range 12,168 months). Results, When we considered significant nodule size decrease criteria as decreases in nodule volume of at least 15% and 30%, we found that 33·1% and 20·7% of thyroid nodules decreased in size, respectively. Using the criteria of a greater than 15% and 30% increase in volume showed that 32% and 24·1% increased in size, respectively. A logistic regression analysis using mixed models to predict thyroid nodule growth (volume change , 15%), including age, TSH, sex and time between evaluations, failed to predict nodule growth. Only hypoechoic echo pattern remained as a statistically significant predictor of growth. Conclusion, In 40 months' follow-up, we found that benign thyroid nodules exhibited a mostly favourable clinical natural course. One-third of benign thyroid nodules showed continuous growth, one-third remained unchanged, and the other third decreased in size. [source] | |||||||||||||