Invasive Nature (invasive + nature)

Distribution by Scientific Domains

Selected Abstracts

Perspective: Reconsidering the Effects of Antiresorptive Therapies in Reducing Osteoporotic Fracture

C. H. Chesnut III
Abstract Concepts of what constitutes osteoporosis have evolved from the single criterion of low bone mass to a more inclusive consideration of bone strength, based on both quantity and quality. The evidence driving this shift is drawn from many sources. For example, recent studies of bone geometry have shown what engineers have always known: material properties and structural strength are inseparable. Genetic factors also argue against a one-dimensional (1D) view of osteoporosis. Large-scale family studies present a strong case for genetic influences on bone mass and predisposition to fracture. The contribution of aging to fracture risk has long been known, but we are only now beginning to understand what happens to bone remodeling and microstructure in an aging skeleton. The recognition that osteoporosis is far more complex than previously thought suggests that factors in addition to bone mineral density (BMD) may be useful for evaluating bone fragility and therapeutic effectiveness. Although assessment of BMD is noninvasive and widely available, the degree of increase in BMD alone fails to account for the broader effectiveness of antiresorptive agents in reducing the risk of fractures related to osteoporosis. Indeed, the very multiplicity of factors that determine fracture risk implies that response to therapy may be equally complex. Studies of response to antiresorptive agents and the cellular processes they induce are at best preliminary at this time. Although new technologies have been applied to studying bone microarchitecture, their invasive nature limits wide use. New methods are needed to provide insight into the causes and effects of bone fragility. The definition of osteoporosis, meanwhile, must still be considered a work in progress. [source]

Western corn rootworm (Diabrotica virgifera virgifera LeConte) population dynamics

Lance J. Meinke
Abstract 1,The western corn rootworm Diabrotica virgifera virgifera LeConte is a major insect pest of field maize, Zea mays L. Larvae can cause substantial injury by feeding on maize roots. Larval feeding may destroy individual roots or root nodes, and reduce plant growth, stability, and yield. Costs associated with managing corn rootworms in continuous maize are annually one of the largest expenditures for insect management in the United States Corn Belt. 2,Even though D. virgifera virgifera has been studied intensively for over 50 years, there is renewed interest in the biology, ecology, and genetics of this species because of its ability to rapidly adapt to management tactics, and its aggressive invasive nature. 3,This article provides a comprehensive review of D. virgifera virgifera population dynamics, specifically: diapause, larval and adult development, seasonality, spatial and temporal dynamics at local and landscape scales, invasiveness in North America and Europe, and non-trophic interactions with other arthropods. 4,Gaps in current knowledge are identified and discussed especially within the context of challenges that scientists in North America and Europe are currently facing regarding pest dynamics and the need to develop appropriate management strategies for each geographic area. [source]

Lung Function Tests in Neonates and Infants with Chronic Lung Disease: Forced Expiratory Maneuvers

Sooky Lum PhD
Abstract This fourth paper in a review series on the role of lung function testing in infants and young children with acute neonatal disorders and chronic lung disease of infancy (CLDI) addresses measurements of forced expiration using rapid thoraco-abdominal compression (RTC) techniques and the forced deflation technique. Following orientation of the reader to the subject area, we focus our comments on the areas of inquiry proposed in the introductory paper to this series. The quality of the published literature is reviewed critically, and recommendations are provided to guide future investigation in this field. All studies on infants and young children with CLDI using forced expiratory or deflation maneuvers demonstrated that forced flows at low lung volume remain persistently low through the first 3 years of life. Measurement of maximal flow at functional residual capacity (V,maxFRC) is the most commonly used method for assessing airway function in infants, but is highly dependent on lung volume and airway tone. Recent studies suggested that the raised volume RTC technique, which assesses lung function over an extended volume range as in older children, may be a more sensitive means of discriminating changes in airway function in infants with respiratory disease. The forced deflation technique allows investigation of pulmonary function during the early development of CLDI in intubated subjects, but its invasive nature precludes its use in the routine setting. For all techniques, there is an urgent need to establish suitable reference data and evaluate within- and between-occasion repeatability, prior to establishing the clinical usefulness of these techniques in assessing baseline airway function and/or response to interventions in subjects with CLDI. Pediatr Pulmonol. 2005 Wiley-Liss, Inc. [source]

Endoscopic treatment of symptomatic refluxing renal transplant ureteroneocystostomies in children

Vijaya M. Vemulakonda
Vemulakonda VM, Koyle MA, Lendvay TS, Risk MC, Kirsch AJ, Cheng EY, Cisek LJ, Campbell JB. Endoscopic treatment of symptomatic refluxing renal transplant ureteroneocystostomies in children. Pediatr Transplantation 2010:14:212,215. 2009 John Wiley & Sons A/S. Abstract:, To present a multi-center experience with the use of Dx/HA copolymer for treatment of symptomatic refluxing renal transplant UNC in children. A multi-center, retrospective chart review was performed. Eleven patients with a mean age of eight yr underwent renal transplantation with an anti-refluxing UNC. Data were collected to determine the safety and effectiveness of the procedure and to identify possible predictors of success. Endoscopic treatment was successful in one of five males and five of six females, for an overall success rate of 54.5%. The etiology of renal failure was associated with success of treatment, with 4/6 (67%) patients with upper tract pathology demonstrating resolution of the VUR, as compared with one of three (33%) patients with lower tract pathology. Male patients had a higher incidence of lower tract pathology. No complications were associated with the endoscopic procedure. Endoscopic injection of Dx/HA remains a safe option for the treatment of symptomatic refluxing transplant UNC in children. Although the success rate is lower than that seen in the treatment of primary VUR, the minimally invasive nature and safety of this technique may offer advantages over open reconstruction of the refluxing transplant ureter. [source]

Effect of a new infrared light device (1100,1800 nm) on facial lifting

J. Y. Ahn
Summary Laser skin resurfacing procedures can be classed into two categories , invasive and non-invasive. The last several decades have witnessed a host of advancements in ablative laser therapy and other ablative modalities for the rejuvenation of skin, including the CO2 laser, the erbium : yttrium aluminum garnet laser, chemical peels, and dermabrasion. Despite the excellent results that can result from the practice of these techniques by experienced surgeons, the invasive nature of these devices is associated with inherent risks and patient discomfort. Therefore, much of the focus has been on non-ablative lasers and intense-pulsed light devices. We evaluated the efficacy and safety of treatment with the new infrared light device (1100,1800 nm), Titan, and assessed the degree of improvement associated with two-time laser treatments, as compared to one-time laser treatment. [source]

Estimating Subglottal Pressure via Airflow Redirection,

Christopher D. Baggott
Abstract Subglottal pressure (SGP) is a valuable parameter in the research and clinical assessment of laryngeal function. The lungs serve as a constant pressure source during sustained phonation, and that pressure, SGP, can be used to determine the efficiency with which the larynx converts aerodynamic power to acoustic power. As the larynx serves as an aerodynamic transducer, the vocal efficiency (Ve) coefficient, defined as acoustic power (dB) divided by aerodynamic power (SGP glottal airflow) has been shown to reliably reflect vocal health. However, current SGP measurement techniques are hesitantly used because of either an invasive nature or the requirement of intensive patient training. This study tests a novel device that has been designed to noninvasively estimate SGP through mechanical airflow redirection, producing a numeric output on completion of the trial, which lasts only a few seconds. The novelty of this design lies in the ease of use for both the patient and the clinician. Multiple mechanical airflow redirections occlude the airway for only 135 ms, which is predicted to limit the effect of confounding laryngeal reflexes that may occur during the trials. Additionally, the airflow redirection into a retention device allows for the pneumatic in-trial comparison of the estimated SGP with the pressure achieved by the patient, providing a numeric output to the clinician on completion. [source]

Aerodigestive Tract Invasion by Well-Differentiated Thyroid Carcinoma: Diagnosis, Management, Prognosis, and Biology

Judith Czaja McCaffrey MD
Objectives/Hypothesis: 1) To describe the clinical entity invasive well-differentiated thyroid carcinoma (IWDTC), 2) to determine prognostic factors for survival in patients with IWDTC, 3) to describe and compare types of surgical resection to determine treatment efficacy, 4) to offer a staging system and surgical algorithm for management of patients with IWDTC, 5) to examine alterations in expression of E-cadherin and ,-catenin adhesion molecules in three groups of thyroid tissue and propose a cellular mechanism for invasion of the aerodigestive tract. Study Design: Basic science: quantification of expression of E-cadherin and ,-catenin in three groups of thyroid tissue. Clinical: retrospective review of patients with IWDTC surgically treated and followed over a 45-year time period. Methods: Basic science: immunohistochemical staining was used with antibodies against E-cadherin and ,-catenin in three groups of tissue: group 1, normal control thyroid tissue (n = 10); group 2, conventional papillary thyroid carcinoma (n = 20); group 3, IWDTC (n = 12). Intensity scores were given on the basis of protocol. One-way analysis of variance (ANOVA) was used to evaluate differences between groups. Post hoc ANOVA testing was completed. P < .05 was significant. Clinical: patients were divided into three surgical groups within the laryngotracheal subset: group 1, complete resection of gross disease (n = 34); group 2, shave excision (n = 75); group 3, incomplete excision (n = 15). Cox regression analysis was used to determine significance of prognostic factors. Kaplan-Meier plots were used to evaluate survival. P < .05 was significant. Results: Basic science: a significant difference between the three thyroid tissue groups for E-cadherin expression was demonstrated on one-way ANOVA testing. When controls were compared with either experimental group in post hoc ANOVA testing, differences between all groups were demonstrated (P < .001). For ,-catenin, the intensities of the three groups were not different by one-way ANOVA testing. Similar nonsignificant results were found on post hoc ANOVA testing. Clinical: there was a statistically significant difference in survival for patients with and without involvement of any portion of the endolarynx or trachea (P < .01). There was a significant difference among all three surgical groups when compared (P < .001). When complete and shave groups were compared with gross residual group there was a significant decrease in survival in incomplete resection group (P < .01). Cox regression analysis demonstrated invasion of larynx and trachea were significant prognostic factors for poor outcome. The type of initial resection was significant on multivariate analysis. Removal of all gross disease is a major factor for survival. Conclusions: Basic science: there is a decrease in membrane expression of E-cadherin in IWDTC, and loss of this tumor suppressor adhesion molecule may contribute to the invasive nature of well-differentiated thyroid carcinomas. Clinical: laryngotracheal invasion is a significant independent prognostic factor for survival. Patients undergoing shave excision had similar survival when compared with those undergoing radical tumor resection if gross tumor did not remain. Gross intraluminal tumor should be resected completely. Shave excision is adequate for minimal invasion not involving the intraluminal surfaces of the aerodigestive tract. [source]

980-nm laser therapy versus varicose vein surgery in racially diverse Penang, Malaysia

Murli N. Lakhwani
Abstract Background:, Chronic venous disorders are conditions of increasing prevalence in the developing world, and venous ulceration is the terminal sequel. Currently there are only limited data on all aspects of this from Southeast Asia. The aim of the present study was to assess differences in the demography and outcome between varicose vein surgery (VVS) and the relatively new endovenous laser therapy (EVT) in patients from Penang, Malaysia. Methods:, A retrospective study was performed. Patients who presented to the outpatient clinic of the surgical department with saphenofemoral junction and/or saphenopopliteal junction incompetence associated with reflux of the great saphenous vein or small saphenous vein, respectively, underwent either surgery (1999,2004) or laser therapy (2004,2006). A single surgeon at a single institution performed all procedures. Results:, A total of 350 limbs were treated from 292 patients. Demographics, symptoms, outcomes and complications that arose in both groups were compared. There were significant improvements in pains, swelling, cramps and heaviness postoperatively (P < 0.001) in both groups. Deep venous thrombosis was present as a complication in the VVS group at 3.0%, but was absent altogether in the EVT group. Conclusions:, Although both are highly effective procedures, laser therapy has become popular as an elective procedure with its minimally invasive nature, cosmesis, rapid recovery and other advantages. Surgery remains an important and very cost-effective procedure, especially in a developing society such as Penang. [source]

Cadherin 11 promotes invasive behavior of fibroblast-like synoviocytes

Hans P. Kiener
Objective To define the expression pattern of cadherin 11 in the destructive pannus tissue of patients with rheumatoid arthritis, and to determine whether cadherin 11 expression in fibroblast-like synoviocytes controls their invasive capacity. Methods Cadherin 11 expression in rheumatoid synovial tissue was evaluated using immunohistochemistry. To examine the role of cadherin 11 in regulating the invasive behavior of fibroblast-like synoviocytes, we generated L cell clones expressing wild-type cadherin 11, mutant cadherin 11, and empty vector,transfected controls. The invasive capacity of L cell transfectants and cultured fibroblast-like synoviocytes treated with a blocking cadherin 11,Fc fusion protein or control immunoglobulin was determined in Matrigel invasion assays. Results Immunohistochemical analysis revealed that cadherin 11 is abundantly expressed in cells at the cartilage,pannus junction in rheumatoid synovitis. Assays to determine invasion demonstrated a 2-fold increased invasive capacity of cadherin 11,transfected L cells compared with L cells transfected with E-cadherin or control vector. The invasive behavior of L cells stably transfected with a cadherin 11 construct that lacked the juxtamembrane cytoplasmic domain was diminished to the level of vector control L cells. Furthermore, treatment with the cadherin 11,Fc fusion protein diminished the invasive capacity of fibroblast-like synoviocytes. Conclusion The results of these in vitro studies implicate a role for cadherin 11 in promoting cell invasion and contribute insight into the invasive nature of fibroblast-like synoviocytes in chronic synovitis and rheumatoid arthritis. [source]

Keloid-derived fibroblasts show increased secretion of factors involved in collagen turnover and depend on matrix metalloproteinase for migration

M. Fujiwara
Summary Background, ,A keloid is a specific skin lesion that expands beyond the boundaries of the original injury as it heals. Histologically, it is characterized by the excessive accumulation of collagen. However, the reasons for the expansion and the invasive nature of keloids remain unknown. Objectives, We evaluated collagen degradation and migration by cultured keloid fibroblasts based on the assumption that these variables were of functional relevance to the expanding and invasive nature of keloid lesions. Methods, Collagen production was investigated by the detection of type 1 collagen (procollagen type 1C peptide: P1P). Matrix metalloproteinase (MMP)-1 (interstitial collagenase) and MMP-2 (gelatinase-A), were investigated as elements of the collagen degradation system. Enzyme immunoassays were performed to measure the production of P1P, MMP-1, MMP-2, and tissue inhibitor of metalloproteinase (TIMP)-1. To assess the production of MMP-2 its gelatinolytic activity was measured by zymography using gelatin-containing gels. The participation of transforming growth factor-,1 (TGF-,1) in the production and degradation of collagen was also investigated. Finally, the migratory activity of keloid fibroblasts was evaluated using a colony dispersion assay. Results, The production of type 1 collagen, MMP-1, MMP-2, and TIMP-1 by keloid fibroblasts was 3-fold, 6-fold, 24-fold, and 2-fold greater than that of normal dermal fibroblasts, respectively. Production of P1P was increased when TGF-,1 was added to cultures of keloid fibroblasts, while it was decreased when anti-TGF-,1 antibody was added to the cultures. In contrast, the production of MMP-1 was decreased by the addition of TGF-,1 to cultured keloid fibroblasts, while it was increased when anti-TGF-,1 antibody was added to the cultures. The production of MMP-2 increased after treatment with TGF-,1, but did not change significantly when anti-TGF-,1 antibody was added to the cultures. Production of TIMP-1 did not change significantly when either TGF-,1 or anti-TGF-,1 antibody was added to the cultures. Keloid fibroblasts showed a 25-fold increase of migratory activity compared with normal dermal fibroblasts, while the migratory activity of these fibroblasts was reduced to the control level by treatment with a broad-spectrum MMP inhibitor (GM 6001). Conclusions, Cultured keloid fibroblasts showed increased production of collagen and MMPs, and TGF-,1 played a role in this regulation of production. In addition, increased production of MMPs had a role in the high migratory activity of cultured keloid fibroblasts. [source]