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2 Other Domains6%
Distribution within Medical Sciences
Nursing General28%
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Neurology6%
Cardiovascular Disease3%
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28 Other Subdomains40%

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    • Selected Abstracts

    Democracy and Cultural Rights: Is There a New Stage of Citizenship?

    CONSTELLATIONS: AN INTERNATIONAL JOURNAL OF CRITICAL AND DEMOCRATIC THEORY, Issue 2 2002
    María Pía Lara
    First page of article [source]

    Crystal structure of 4-(1-methyl-1-mesitylcyclobutane-3-yl)-2-aminothiazole

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2006
    . Aksoy
    Abstract The crystal structure of 4-(1-methyl-1-mesitylcyclobutane-3-yl)-2-aminothiazole (C17H22N2S1) has been determined by X-ray crystallographic techniques. The compound crystallizes in the triclinic space group P-1 with Z = 6. The crystal structure was solved by direct methods and refined by full-matrix least squares to a final R-value of 0.052 for 2298 observed reflections [I > 2, ( I ) ]. There are three crystallographically independent molecules, I, II and III. These molecules are held together by intermolecular N-H...N hydrogen bonds. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim [source]

    A Comparison of Four Mohs Tissue Preparation Methods Using Porcine Skin

    DERMATOLOGIC SURGERY, Issue 9 2010
    FRCPC, WILLIAM LEAR MD
    OBJECTIVE Mohs surgery relies on high-quality, rapid tissue preparation and processing. This study evaluated four currently performed tissue preparation and processing methods for speed of processing and depth of cut into the tissue block to achieve a complete high-quality section. METHODS The following four methods were tested: cryoEMBEDDER, float, heat sink, and slide. Standardized specimens of porcine skin were used to ensure uniformity. We measured the time required for a technician to flatten, embed, and cut to the first complete section of each specimen. Additionally, we measured the depth in microns required to cut into an embedded specimen to achieve a complete section. RESULTS There were advantages and disadvantages of each method, and our findings suggest that the heat sink and float methods are more time efficient but that the slide and cryoEMBEDDER methods require less cutting into the specimen to obtain a complete section. The cryoEMBEDDER device used in this study was loaned by cryoEMBEDDER (Salt Lake City, Utah). [source]

    Use of High-Frequency, High-Resolution Ultrasound Before Mohs Surgery

    DERMATOLOGIC SURGERY, Issue 6 2010
    ELLEN S. MARMUR MD
    BACKGROUND Although ultrasound imaging is employed ubiquitously today, its use to examine and assess the skin is a relatively new technology. We explored the clinical application and use of high-frequency, high-resolution ultrasound in Mohs micrographic surgery. OBJECTIVE To evaluate the ability of ultrasound to accurately determine lesion length and width of tumor borders in order to reduce the number of surgical stages. METHODS AND MATERIALS This was an institutional review board,approved single-center study of 26 Mohs surgery patients. Ultrasound images were taken to record lesion dimensions, and then the investigator documented clinical estimation of the first stage. Extirpation of the tumor and histological analysis were performed thereafter. RESULTS The results of 20 patients were included in the analysis. A paired-samples t -test revealed no significant difference between clinical and ultrasound widths (t=,1.324, p=.20). Similarly, there was no significant difference between the lengths found from clinical assessment and ultrasound (t=,1.093, p=.29). For different tumor types, there was no significant difference between clinical and ultrasound widths or lengths for basal cell carcinoma (t=,1.307, p=.23; t=,1.389, p=.20) or squamous cell cancer (t=,0.342, p=.73; t=0.427, p=.68). CONCLUSION There is a diagnostic role for high-resolution ultrasound in Mohs surgery regarding the delineation of surgical margins, but its limitations preclude its practical adoption at this time. The ultrasound equipment was loaned to the investigators. Funding for the study was provided by Longport, Inc. [source]

    Viability of Preadipocytes In Vitro: The Influence of Local Anesthetics and pH

    DERMATOLOGIC SURGERY, Issue 8 2009
    MAIKE KECK MD
    BACKGROUND Autogenous fat transfer with lipoinjection for soft tissue augmentation is a commonly used surgical technique. Abundant donor tissue availability and relative ease of harvesting have made autologous fat an attractive soft tissue filler. The overall reliability of this technique is often disputed, and different authors describe different results after autologous fat transplantation despite using similar techniques. In this study, we examined the influence of different local anesthetics commonly used in fat harvest and the pH of the anesthetic solution on the viability of harvested preadipocytes. METHODS AND MATERIALS Preadipocytes were incubated with 1% lidocaine, 1% articaine plus epinephrine 1:200,000, 0.75% ropivacaine, and 1% prilocaine or our standardized tumescent solution (1 L of 0.9% sodium chloride solution plus 25 mL of 1% articaine plus epinephrine 1:200,000 plus 25 mL of bicarbonate) for 30 minutes. Additionally, we incubated cells with the local anesthetics as described above but diluted 1:2 with phosphate buffered saline (pH 7.4). Viability was measured using trypan blue dying as well as propidium iodine staining and fluorescence-activated cell sorting analysis. RESULTS There are significant differences in the viability of preadipocytes under the influence of various local anesthetics. DISCUSSION Our data could partially explain the varying results after autogenous fat transfer. [source]

    Surgical Monotherapy Versus Surgery Plus Adjuvant Radiotherapy in High-Risk Cutaneous Squamous Cell Carcinoma: A Systematic Review of Outcomes

    DERMATOLOGIC SURGERY, Issue 4 2009
    ANOKHI Jambusaria-PAHLAJANI MD
    BACKGROUND Adjuvant radiotherapy (ART) has been recommended for squamous cell carcinoma (SCC) with a high risk of recurrence, particularly perineurally invasive disease. The utility of ART is unknown. This study compares reported outcomes of high-risk SCC treated with surgical monotherapy (SM) with those of surgery plus ART (S+ART). METHODS The Medline database was searched for reports of high-risk SCC treated with SM or S+ART that reported outcomes of interest: local recurrence, regional or distant metastasis, or disease-specific death. RESULTS There were no controlled trials. Of the 2,449 cases of high-risk SCC included, 91 were treated with S+ART. Tumor stage and surgical margin status before ART were generally unreported. In 74 cases of perineural invasion (PNI), outcomes were statistically similar between SM and S+ART. In 943 high-risk SCC cases in which clear surgical margins were explicitly documented, risks of local recurrence, regional metastasis, distant metastasis, and disease-specific death were 5%, 5%, 1%, and 1%, respectively. CONCLUSIONS High cure rates are achieved in high-risk cutaneous SCC when clear surgical margins are obtained. Current data are insufficient to identify high-risk features in which ART may be beneficial. In cases of PNI, the extent of nerve involvement appears to affect outcomes, with involvement of larger nerves imparting a worse prognosis. [source]

    Randomized Nonblinded Comparison of Convalescence for 2 and 7 Days After Split-Thickness Skin Grafting to the Lower Legs

    DERMATOLOGIC SURGERY, Issue 4 2009
    BEN TALLON MBChB
    BACKGROUND There is an increasing expectation of shortened postoperative recovery times and a suggestion that shorter convalescence times may not compromise lower leg split-thickness skin graft results. OBJECTIVE To determine whether mobilization after 2 days of convalescence compromises graft survival or patient morbidity. METHODS AND MATERIALS A pilot study was initiated in which patients undergoing split-thickness skin grafting to the lower legs were randomized to 2 or the routine 7 days of convalescence. Baseline characteristics were determined, and patients were followed up in dressing clinics and with a standardized telephone interview. RESULTS There was no difference in baseline patient comorbidities and no significant difference in the number of grafts lost, the number of dressing clinics, bleeding, or wound infections. CONCLUSION The results suggest that 2 days of convalescence after split-thickness skin grafting to the lower legs may not compromise graft survival or increase patient morbidity. Further study with larger numbers is required to confirm this finding. [source]

    Treatment of Melasma Using Variable Square Pulse Er: YAG Laser Resurfacing

    DERMATOLOGIC SURGERY, Issue 3 2009
    RUNGSIMA WANITPHAKDEEDECHA MD
    BACKGROUND Treatment of melasma remains a challenge. Laser treatments show limited efficacy, with a high rate of recurrence and side effects. Recently, variable-pulsed erbium:yttrium aluminum garnet (Er:YAG) lasers have shown favorable results in skin resurfacing, with minimal downtime and adverse effects. OBJECTIVE To determine the efficacy and side effects of variable square pulsed (VSP) Er:YAG laser resurfacing for treatment of epidermal type melasma. METHODS Twenty Thai women with epidermal-type melasma were treated with two passes of VSP Er:YAG laser resurfacing using a 7-mm spot size, pulse duration of 300 ,s, and a fluence of 0.4 J/cm2. Two treatments were given 1 month apart. Visual analog scale (VAS), Melasma Area and Severity Index (MASI) score and melanin index (MI) were measured at baseline and 1, 2, and 4 months after treatment. RESULTS There was a significant improvement in VAS from baseline at 1-, 2-, and 4-month follow-up visits (p<.001). Significant improvement in MASI score at the 2-month visit from baseline (p=.004) was also observed. The average MI measured using melanin reflectance spectrometry measurements corresponded to MASI score rating. CONCLUSIONS VSP Er:YAG laser resurfacing effectively but temporarily improved epidermal-type melasma. Recurrence was observed after the treatment was discontinued. [source]

    Hydrogen Peroxide and Wound Healing: A Theoretical and Practical Review for Hair Transplant Surgeons

    DERMATOLOGIC SURGERY, Issue 6 2008
    SARA WASSERBAUER MD
    BACKGROUND In most hair restoration practices, hydrogen peroxide has been routinely used to remove blood during and after hair transplant surgery. In other specialties, hydrogen peroxide is also used in these ways: wound cleaning, prevention of infection, hemostasis, and removal of debris. Despite its widespread use, there are still concerns and controversy about the potential toxic effect of hydrogen peroxide. OBJECTIVE The objective was to review all available literature including in vivo and in vitro effects of hydrogen peroxide, as well as general wound healing research. MATERIAL AND METHODS Literature up to and including the past three decades was investigated. RESULTS Two pilot studies were found, and there are not enough data examining the real impact of using hydrogen peroxide in hair transplant surgery. In other specialties, H2O2 appears to have positive effects, such as stimulation of vascular endothelial growth factor, induction of fibroblast proliferation, and collagen, or negative effects, such as cytotoxicity, inhibition of keratinocyte migration, disruption of scarless fetal wound repair, and apoptosis. CONCLUSIONS There are not enough data in hair restoration surgery about the use of hydrogen peroxide, and it is unknown and unclear what the optimum dilution should be. Positive and negative effects were found in other specialties. Further studies are recommended. [source]

    A Randomized Trial to Determine the Influence of Laser Therapy, Monopolar Radiofrequency Treatment, and Intense Pulsed Light Therapy Administered Immediately after Hyaluronic Acid Gel Implantation

    DERMATOLOGIC SURGERY, Issue 5 2007
    MITCHEL P. GOLDMAN MD
    BACKGROUND Hyaluronic acid-based dermal fillers, such as hyaluronic acid gel (Restylane, Q-Medical AB, Uppsala, Sweden), are widely used for tissue augmentation of the nasolabial folds. Additional dermatologic treatments using infrared light, radiofrequency (RF), and intense pulsed light (IPL) are also important tools for facial rejuvenation. This study was designed to evaluate whether these therapies could be safely administered immediately after hyaluronic acid gel treatment without compromising the effect of the dermal filler. OBJECTIVE The objective of this study was to confirm or refute any possible subtractive effects of augmentation of the nasolabial folds when followed by 1,320-nm Nd:YAG laser, 1,450-nm diode laser, monopolar RF, and/or IPL treatments. METHODS Thirty-six patients with prominent nasolabial folds were treated with hyaluronic acid gel implantation on one side of the face and hyaluronic acid gel followed by one of the nonablative laser/RF/IPL therapies on the contralateral side of the face. RESULTS There were no statistically significant differences between wrinkle severity or global aesthetic scores for hyaluronic acid gel implantation alone and hyaluronic acid gel with laser/RF/IPL treatment at any time point. In a small sample, histologic changes were not apparent after laser/RF/IPL treatment. CONCLUSIONS Based on this small pilot study, laser, RF, and IPL treatments can safely be administered immediately after hyaluronic acid gel implantation without reduction in overall clinical effect. [source]

    High-Risk Cutaneous Squamous Cell Carcinoma without Palpable Lymphadenopathy: Is There a Therapeutic Role for Elective Neck Dissection?

    DERMATOLOGIC SURGERY, Issue 4 2007
    JUAN-CARLOS MARTINEZ MD
    PURPOSE The beneficial role of elective neck dissection (END) in the management of high-risk cutaneous squamous cell carcinoma (CSCC) of the head and neck remains unproven. Some surgical specialists suggest that END may be beneficial for patients with clinically node-negative (N0) high-risk CSCC, but there are few data to support this claim. We reviewed the available literature regarding the use of END in the management of both CSCC and head and neck SCC (HNSCC). METHODOLOGY The available medical literature pertaining to END in both CSCC and HNSCC was reviewed using PubMed and Ovid Medline searches. RESULTS Many surgical specialists recommend that END be routinely performed in patients with N0 HNSCC when the risk of occult metastases is estimated to exceed 20%; however, patients who undergo END have no proven survival benefit over those who are initially staged as N0 and undergo therapeutic neck dissection (TND) after the development of apparent regional disease. There is a lack of data regarding the proper management of regional nodal basins in patients with N0 CSCC. In the absence of evidence-based data, the cutaneous surgeon must rely on clinical judgment to guide the management of patients with N0 high-risk CSCC of the head and neck. CONCLUSIONS Appropriate work-up for occult nodal disease may occasionally be warranted in patients with high-risk CSCC. END may play a role in only a very limited number of patients with high-risk CSCC. [source]

    So You Want to Be a Dermasurgeon: How to Get Training or Choose a Fellowship

    DERMATOLOGIC SURGERY, Issue 9 2006
    MURAD ALAM MD
    BACKGROUND There are many routes to obtaining training in dermasurgery. OBJECTIVE The objective is to discuss some considerations that may guide selection of dermasurgery training. METHODS Current training options are reviewed. RESULTS Some considerations that may guide selection of type of dermasurgery training include: (1) individual temperament; (2) the subtype of dermasurgery in which training is desired (Mohs, cosmetic surgery, laser); (3) family and geographic factors; (4) preference for private practice versus academic career; and (5) proportion of future practice to be devoted to dermasurgery. CONCLUSIONS There are a growing number of training choices for budding dermasurgeons, with multiple options available for each set of particular circumstances. [source]

    Frequency of Use of Suturing and Repair Techniques Preferred by Dermatologic Surgeons

    DERMATOLOGIC SURGERY, Issue 5 2006
    BETH ADAMS MD
    BACKGROUND There are many closure techniques and suture types available to cutaneous surgeons. Evidence-based data are not available regarding the frequency of use of these techniques by experienced practitioners. OBJECTIVE To quantify, by anatomic site, the frequency of use of common closure techniques and suture types by cutaneous surgeons. METHOD A prospective survey of the members of the Association of Academic Dermatologic Surgeons that used length-calibrated visual-analog scales to elicit the frequency of use of specific suture techniques. RESULTS A response rate of 60% (61/101) indicated reliability of the received data. Epidermal layers were closed most often, in descending order, by simple interrupted sutures (38,50%), simple running sutures (37,42%), and vertical mattress sutures (3,8%), with subcuticular sutures used more often on the trunk and extremities (28%). The most commonly used superficial sutures were nylon (51%) and polypropylene (44%), and the most common absorbable suture was polyglactin 910 (73%). Bilayered closures, undermining, and electrocoagulation were used, on average, in 90% or more sutured repairs. The median diameters (defined as longest extent along any axis) of most final wound defects were 1.1 to 2.0 cm (56%) or 2.1 to 3.0 cm (37%). Fifty-four percent of wounds were repaired by primary closure, 20% with local flaps, and 10% with skin grafting, with the remaining 15% left to heal by second intent (10%) or referred for repair (5%). Experience-related differences were detected in defect size and closure technique: defects less than 2 cm in diameter were seen by less experienced surgeons, and defects greater than 2 cm by more experienced surgeons (Wilcoxon's rank-sum test: p=.02). But more experienced surgeons were less likely to use bilayered closures (r=,0.28, p=.036) and undermining (r=,0.28, p=.035). CONCLUSIONS There is widespread consensus among cutaneous surgeons regarding optimal suture selection and closure technique by anatomic location. More experienced surgeons tend to repair larger defects but, possibly because of their increased confidence and skill, rely on less complicated repairs. [source]

    Prevention of Nosocomial Infection During Dermoscopy?

    DERMATOLOGIC SURGERY, Issue 4 2006
    SUSAN C. KELLY DO
    BACKGROUND Dermatoscopes are applied directly to cutaneous or mucocutaneous surfaces with immersion fluid (IF) such as oil or alcohol to reduce light reflection. Recently, Staphylococcus aureus has been isolated from dermatosopes that used mineral oil as the IF. Thus, dermatoscopes might be a potential source of nosocomial infection. OBJECTIVE In this study we propose the use of an alcohol-based antibacterial gel to reduce nosocomial infection transmission while optimizing optical resolution during dermatoscopic examination. MATERIALS AND METHODS Aerobic bacterial cultures were performed on three dermatoscopes used in an outpatient setting after routine examination of 31 patients with an alcohol-based antibacterial gel as IF. RESULTS There was no bacterial growth after using the antibacterial gel with the dermatoscopes. The optical resolution for the antibacterial gel appeared equal to the ,dermatoscopy oil' and superior to alcohol wipes. CONCLUSIONS Alcohol-based antibacterial gel appears to inhibit bacterial colonization while offering excellent optical resolution during dermoscopic examination. The use of alcohol-based IF appears to obviate the risk of nosocomial infections. [source]

    A new endoscopic technique for suspension of esophageal prosthesis for refractory caustic esophageal strictures

    DISEASES OF THE ESOPHAGUS, Issue 3 2008
    E. Ancona
    SUMMARY., There is no clear consensus concerning the best endoscopic treatment of benign refractory esophageal strictures due to caustic ingestion. Different procedures are currently used: frequent multiple dilations, retrievable self-expanding stent, nasogastric intubation and surgery. We describe a new technique to fix a suspended esophageal silicone prosthesis to the neck in benign esophageal strictures; this permits us to avoid the frequent risk of migration of the expandable metallic or plastic stents. Under general anesthesia a rigid esophagoscope was placed in the patient's hypopharynx. Using transillumination from the optical device, the patient's neck was pierced with a needle. A n.0 monofilament surgical wire was pushed into the needle, grasped by a standard foreign body forceps through the esophagoscope and pulled out of the mouth (as in percutaneous endoscopic gastrostomy procedure). After tying the proximal end of the silicone prosthesis with the wire, it was placed through the strictures under endoscopic view. This procedure was successfully utilized in four patients suffering from benign refractory esophageal strictures due to caustic ingestion. The prosthesis and its suspension from the neck were well-tolerated until removal (mean duration 4 months). A postoperative transitory myositis was diagnosed in only one patient. One of the most frequent complications of esophageal prostheses in refractory esophageal strictures due to caustic ingestion is distal migration. Different solutions were proposed. For example the suspension of a wire coming from the nose and then fixed behind the ear. This solution is not considered optimal because of patient complaints and moreover the aesthetic aspect is compromised. The procedure we utilized in four patients utilized the setting of a silicone tube hanging from the neck in a way similar to that of endoscopic pharyngostomy. This solution is a valid alternative both for quality of life and for functional results. [source]

    Gastroesophageal reflux: prevalence of psychopathological disorders and quality of life implications

    DISEASES OF THE ESOPHAGUS, Issue 5 2006
    Á. Díaz de Liaño
    SUMMARY., There is evidence in the literature that psychosocial aspects affect the symptoms and results of surgery for gastroesophageal reflux. The purpose of this study was to estimate the prevalence of psychopathological disorders measured using the General Health Questionnaire (GHQ-28) in a sample of patients with gastroesophageal reflux, and to assess the influence of such disorders on their quality of life. A prospective study was conducted in 74 consecutive patients before gastroesophageal reflux surgery; patients answered the GHQ-28, the health questionnaire SF-36, and the Gastrointestinal Quality of Life Index (GIQLI). The convergent validity of the GHQ-28 questionnaire as compared to the other two questionnaires and preoperative quality of life was tested. A pathological result of the GHQ-28 questionnaire was found in 38.3% of patients. A correlation was seen between the results of the GHQ-28 questionnaire and all categories of the SF-36 and GIQLI questionnaires. Patients with pathological results in the GHQ-28 questionnaire had poorer results in all dimensions of the SF-36 and GIQLI quality of life questionnaires as compared to patients with a normal result in the GHQ-28 questionnaire. In conclusion, 38.3% of patients with gastroesophageal reflux showed psychopathological disorders when administered the GHQ-28 questionnaire. These patients also had poorer results in quality of life studies. [source]

    Association of ablation of Barrett's esophagus with high grade dysplasia and adenocarcinoma of the gastric cardia

    DISEASES OF THE ESOPHAGUS, Issue 4 2006
    R. E. Sampliner
    SUMMARY., There has been increasing application of endoscopic ablation therapy for patients with high-grade dysplasia (HGD) and Barrett's esophagus (BE). Three cases are reported in which the patient developed adenocarcinoma of the gastric cardia after thermal ablation of HGD. A definition of BE including endoscopic abnormality and intestinal metaplasia by biopsy was used. Strict and standardized criteria were utilized for the endoscopic landmarks. Three cases are reported with long-segment BE and a nodule or mass in the endoscopic cardia post-thermal ablation. Biopsies documented adenocarcinoma of the gastric cardia. The development of adenocarcinoma of the cardia is unexpected. Speculation is offered as to the potential of increased proliferation and mutations at the new squamocolumnar interface after endoscopic ablation therapy to explain this association. [source]

    Taxonomic diversity gradients through geological time

    DIVERSITY AND DISTRIBUTIONS, Issue 4 2001
    J. Alistair Crame
    Abstract., There is evidence from the fossil record to suggest that latitudinal gradients in taxonomic diversity may be time-invariant features, although almost certainly not on the same scale as that seen at the present day. It is now apparent that both latitudinal and longitudinal gradients increased dramatically in strength through the Cenozoic era (i.e. the last 65 my) to become more pronounced today than at any time in the geological past. Present-day taxonomic diversity gradients, in both the marine and terrestrial realms, are underpinned by the tropical radiations of a comparatively small number of species-rich clades. Quite why these particular taxa proliferated through the Cenozoic is uncertain, but it could be that at least part of the explanation involves the phenomenon of evolutionary escalation. This is, in essence, a theory of biological diversification through evolutionary feedback mechanisms between predators and prey; first one develops an adaptive advantage, and then the other. However, there may also have been some form of extrinsic control on the process of tropical diversification, and this was most likely centred on the phenomenon of global climate change. This is especially so over the last 15 my Various Late Cenozoic (Neogene) vicariant events effectively partitioned the tropics into a series of high diversity centres, or foci. It has been suggested that, in the largest of these in the marine realm (the Indo-West Pacific or IWP centre), a critical patterns of islands acted as a template for rapid speciation during glacioeustatic sea level cycles. The same process occurred in the Atlantic, Caribbean and East Pacific (ACEP) centre, though on a lesser scale. Tropical terrestrial diversity may also have been promoted by rapid range expansions and contractions in concert with glacial cycles (a modified refugium hypothesis). We are beginning to appreciate that an integrated sequence of Neogene tectonic and climatic events greatly influenced the formation of contemporary taxonomic diversity patterns. [source]

    Mitral Regurgitation Associated with Mitral Annular Dilation in Patients with Lone Atrial Fibrillation: An Echocardiographic Study

    ECHOCARDIOGRAPHY, Issue 8 2009
    Takashi Kihara M.D.
    Background: Whether and how lone atrial fibrillation (AF) is associated with functional mitral regurgitation (MR) remain unclear. Method: We studied 12 lone AF patients without left ventricular (LV) dysfunction and/or dilatation, who underwent mitral valve annuloplasty for functional mitral regurgitation (MR). Ten lone AF patients without MR served as controls. Results: Lone AF Patients with MR had a greater mitral valve annular area and left atrial area than those without MR. There were no differences in LV volumes or LV ejection fraction. Conclusions: Therefore, we concluded that left atrial dilation and corresponding mitral annular dilation may cause MR in lone AF patients without LV dysfunction and/or dilatation. [source]

    ABSENCE OF CORRELATION BETWEEN QRS DURATION AND ECHOGRAPHIC PARAMETERS OF VENTRICULAR DESYNCHRONIZATION.

    ECHOCARDIOGRAPHY, Issue 2 2004
    CAN WE STILL TRUST THE ELECTROCARDIOGRAPHIC CRITERIA?
    Background: Identification of the responder candidates for multisite pacing is still difficult and severe heart failure, dilated left ventricle with reduced ejection fraction, prolonged QRS with left bundle branch block (LBBB) are still considered the principal indicators of ventricular desynchronization. The aim of the study was to assess if echographic ventricular desynchronization parameters measured in patients with dilated cardiomyopathy and severe heart failure are correlated with the duration of the QRS on surface electrocardiogram. Methods: This study included 51 patients aged 58.8 ± 7.4 years with idiopathic DCM. The following parameters were measured: QRS duration; effective contraction time (ECT) measured as the interval between QRS onset and closure of aortic valve, interventricular delay (IVD) measured as the time between onset of aortic and pulmonary flow, left ventricular mechanical delay (LVD) as the time from maximal interventricular septum contraction and posterior wall contraction, posterior (P), lateral (L), and posterolateral (PL) wall delays, as the time from QRS onset to maximal wall contraction. Regional post-systolic contraction was defined in a given wall as the difference (contraction delay , ECT)> 50 ms. Results: 29 patients presented complete LBBB, 22 patients had QRS duration < 120 ms. 39 patients had a post-systolic contraction of the PL wall (32 patients of the L wall and 26 patients of the P wall). 16 patients with QRS duration <120 had a post-systolic contraction of the PL wall (as for the LBBB the rest of 39 patients). In 40 patients the sequence of regional ventricular contraction was: P-L-PL wall (16 patients with QRS < 120). LVD was > 100 ms in 36 patients (26 patients with LBBB and 10 with QRS < 120). 27 patients with LBBB and 6 with QRS < 120 ms presented IVD > 30 ms. There was no correlation between the QRS duration and the parameters listed above. Conclusions: In a population of patients with severe heart failure and dilated cardiomyopathy there is no correlation between the duration of the QRS and echocardiographic parameters of ventricular desynchronization. These results show that mechanical ventricular desynchronization can be observed in patients with a QRS duration < 120 ms. Further studies are needed to evaluate if this population could beneficiate of multisite pacing therapy. [source]

    Genetic and environmental influences on cannabis use initiation and problematic use: a meta-analysis of twin studies

    ADDICTION, Issue 3 2010
    Karin J. H. Verweij
    ABSTRACT Background Because cannabis use is associated with social, physical and psychological problems, it is important to know what causes some individuals to initiate cannabis use and a subset of those to become problematic users. Previous twin studies found evidence for both genetic and environmental influences on vulnerability, but due to considerable variation in the results it is difficult to draw clear conclusions regarding the relative magnitude of these influences. Methods A systematic literature search identified 28 twin studies on cannabis use initiation and 24 studies on problematic cannabis use. The proportion of total variance accounted for by genes (A), shared environment (C) and unshared environment (E) in (i) initiation of cannabis use and (ii) problematic cannabis use was calculated by averaging corresponding A, C and E estimates across studies from independent cohorts and weighting by sample size. Results For cannabis use initiation, A, C and E estimates were 48%, 25% and 27% in males and 40%, 39% and 21% in females. For problematic cannabis use A, C and E estimates were 51%, 20% and 29% for males and 59%, 15% and 26% for females. Confidence intervals of these estimates are considerably narrower than those in the source studies. Conclusions Our results indicate that vulnerability to both cannabis use initiation and problematic use was influenced significantly by A, C and E. There was a trend for a greater C and lesser A component for cannabis use initiation compared to problematic use for females. [source]

    Detection of chlorinated quinones using interdigitated electrodes coupled with capillary electrophoresis

    ELECTROPHORESIS, Issue 6 2003
    Keith B. Male
    Abstract An array of eight interdigitated microband gold electrodes (IDEs) has been developed together with electrophoretic separation for analysis of chlorinated hydroquinones (ClHQs) and benzoquinones (ClBQs). The IDE chip positioned very close to the separation capillary outlet served as an amplification/detection system without the requirement for frequent "capillary-electrode" alignment. ClHQs, electrophoretically migrating to the IDE surface, were oxidized at +1.1 V by seven electrodes of the array and then detected by the remaining electrode, poised at ,0.1 V. Conversely, ClBQs were detected at +1.1 V by the detecting electrode after having been reduced at the 7 adjacent electrodes poised at ,0.1 V. There was an amplification effect on both the detecting electrode as well as the adjacent electrodes because of the recycle between ClHQs and ClBQs. The detecting "amplification" current response was dependent on the potentials applied, the position of the detecting electrode on the array, the number of adjacent electrodes being used for recycling and the distance between the oxidative and reductive electrodes. Micellar electrokinetic chromatography (MEKC) separation of the analytes was achieved using 30 mM sodium dodecyl sulfate (SDS) with a detection limit in the range of 2,20 ,M. In addition to a facile "capillary-electrode" alignment, the important aspect described here was the capability of detecting through recycling a reduced compound (in the case of ClHQs) at a negative potential to circumvent fouling and electroactive interferences. An appealing feature was also the concurrent oxidation/reduction detection for each compound to ascertain peak assignment, as interfering compounds are less likely to exhibit the same oxidative/reductive characteristics and electrophoretic mobilities as the target analytes. [source]

    Labial Gland and Its Protein Patterns of Hydropsychid Caddisfly (Hydropsyche kozhantschikovi Martynov: Trichoptera)

    ENTOMOLOGICAL RESEARCH, Issue 1 2003
    Sang-Chan PARK
    ABSTRACT There is a pair of labial gland of hydropsychid caddisfly (Hydropsyche kozhantschikovi Martynov) larva. It is in ,Z' formation in the body and the total length is about 20 mm. Hydropsychid caddishfly larvae that were raised under the lab conditions were able to form a nest-spining by connecting the small grains of sand provided. By repeatedly treating the extracted labial gland with methanol/D.W., the cell layer was removed. Accordingly, only the matrix within the labial gland that did not dissolve in water was obtained. The matrix inside the methanol/D.W. treated labial gland was dissolved with 5% acetic acid. Then the results of an acidic electrophoresis with a number of conditions indicated that 5% acetic acid/ 5 M urea/ 8% PAGE was the most effective. Moreover, the result of 2-D PAGE on the labial gland of these hydropsychid caddisfly larva, the number of proteins in the labial gland including the cell layer was about 350 and the number of proteins in the labial gland treated with methanol/D.W. was about 80, showing a substantially small number of proteins. [source]

    Growth, activity and temperature responses of ammonia-oxidizing archaea and bacteria in soil microcosms

    ENVIRONMENTAL MICROBIOLOGY, Issue 5 2008
    Maria Tourna
    Summary Ammonia oxidation, as the first step in the nitrification process, plays a central role in the global cycling of nitrogen. Although bacteria are traditionally considered to be responsible for ammonia oxidation, a role for archaea has been suggested by data from metagenomic studies and by the isolation of a marine, autotrophic, ammonia-oxidizing, non-thermophilic crenarchaeon. Evidence for ammonia oxidation by non-thermophilic crenarchaea in marine and terrestrial environments is largely based on abundance of bacterial and archaeal ammonia monooxygenase (amo) genes, rather than activity. In this study, we have determined the influence of temperature on the response of ammonia-oxidizing bacteria and archaea in nitrifying soil microcosms using two approaches, involving analysis of transcriptional activity of 16S rRNA genes and of a key functional gene, amoA, which encodes ammonia monooxygenase subunit A. There was little evidence of changes in relative abundance or transcriptional activity of ammonia-oxidizing bacteria during nitrification. In contrast, denaturing gradient gel electrophoresis analysis of crenarchaeal 16S rRNA and crenarchaeal amoA genes provided strong evidence of changes in community structure of active archaeal ammonia oxidizers. Community structure changes were similar during incubation at different temperatures and much of the activity was due to a group of non-thermophilic crenarchaea associated with subsurface and marine environments, rather than soil. The findings suggest a role for crenarchaea in soil nitrification and that further information is required on their biogeography. [source]

    Cardiopulmonary, blood and peritoneal fluid alterations associated with abdominal insufflation of carbon dioxide in standing horses

    EQUINE VETERINARY JOURNAL, Issue 3 2003
    F. G. LATIMER
    Summary Reasons for performing study: Abdominal insufflation is performed routinely during laparoscopy in horses to improve visualisation and facilitate instrument and visceral manipulations during surgery. It has been shown that high-pressure pneumoperitoneum with carbon dioxide (CO2) has deleterious cardiopulmonary effects in dorsally recumbent, mechanically ventilated, halothane-anaesthetised horses. There is no information on the effects of CO2 pneumoperitoneum on cardiopulmonary function and haematology, plasma chemistry and peritoneal fluid (PF) variables in standing sedated horses during laparoscopic surgery. Objectives: To determine the effects of high pressure CO2 pneumoperitoneum in standing sedated horses on cardiopulmonary function, blood gas, haematology, plasma chemistry and PF variables. Methods: Six healthy, mature horses were sedated with an i.v. bolus of detomidine (0.02 mg/kg bwt) and butorphanol (0.02 mg/kg bwt) and instrumented to determine the changes in cardiopulmonary function, haematology, serum chemistry and PF values during and after pneumoperitoneum with CO2 to 15 mmHg pressure for standing laparoscopy. Each horse was assigned at random to either a standing left flank exploratory laparoscopy (LFL) with CO2 pneumoperitoneum or sham procedure (SLFL) without insufflation, and instrumented for measurement of cardiopulmonary variables. Each horse underwent a second procedure in crossover fashion one month later so that all 6 horses had both an LFL and SLFL performed. Cardiopulmonary variables and blood gas analyses were obtained 5 mins after sedation and every 15 mins during 60 mins baseline (BL), insufflation (15 mmHg) and desufflation. Haematology, serum chemistry analysis and PF analysis were performed at BL, insufflation and desufflation, and 24 h after the conclusion of each procedure. Results: Significant decreases in heart rate, cardiac output and cardiac index and significant increases in mean right atrial pressure, systemic vascular resistance and pulmonary vascular resistance were recorded immediately after and during sedation in both groups of horses. Pneumoperitoneum with CO2 at 15 mmHg had no significant effect on cardiopulmonary function during surgery. There were no significant differences in blood gas, haematology or plasma chemistry values within or between groups at any time interval during the study. There was a significant increase in the PF total nucleated cell count 24 h following LFL compared to baseline values for LFL or SLFL at 24 h. There were no differences in PF protein concentrations within or between groups at any time interval. Conclusions: Pneumoperitoneum with CO2 during standing laparoscopy in healthy horses does not cause adverse alterations in cardiopulmonary, haematology or plasma chemistry variables, but does induce a mild inflammatory response within the peritoneal cavity. Potential relevance: High pressure (15 mmHg) pneumoperitoneum in standing sedated mature horses for laparoscopic surgery can be performed safely without any short-term or cumulative adverse effects on haemodynamic or cardiopulmonary function. [source]

    Increased numbers of mononuclear cells from blood and CSF expressing interferon-gamma mRNA in multiple sclerosis are from both the CD4+ and the CD8+ subsets

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2000
    E. Wallström
    Activated, cytokine-producing lymphocytes may regulate central nervous system (CNS) inflammation in multiple sclerosis (MS). We utilize a novel combination of in situ hybridization (ISH) and immunocytochemical staining of peripheral blood lymphocytes (PBLs) to identify spontaneously interferon-gamma (IFN,) mRNA expressing cells as CD4+ or CD8+. A major proportion of the IFN, mRNA expressing lymphocytes belonged to the CD4+ lineage, which concords with the cellular composition of MS brain lesions, findings in experimental models and the HLA class II haplotype association in MS. There were also significantly more CD8+ IFN, mRNA expressing lymphocytes in the MS patients compared with healthy controls, further suggesting the contribution of activated cells from this lineage in the inflammatory response in MS. Both CD4+ and CD8+ IFN, mRNA expressing cells were enriched in the cerebrospinal fluid (CSF) as compared with the peripheral blood of the MS patients. Combined with emerging genetic data on HLA class I influences, our data argues for a joint role of activated CD8+ and CD4+ cells in the pathogenesis of MS. [source]

    Mechanosensitive hyaluronan secretion: stimulus,response curves and role of transcription,translation,translocation in rabbit joints

    EXPERIMENTAL PHYSIOLOGY, Issue 3 2009
    A. K. T. Wann
    Joint movement was recently shown to stimulate the secretion of the lubricant hyaluronan (HA); also, exercise therapy and intra-articular hyaluronan injections are used to treat moderate osteoarthritis. The present study quantifies the stimulus,response curves for HA secretion in vivo and reports a role of transcription,translation,translocation in the secretory response. After washing out endogenous HA from anaesthetized, cannulated rabbit knees, the joints were cycled passively at various frequencies and durations, with or without intra-articular inhibitors of protein synthesis and Golgi processing. Newly secreted HA was harvested for analysis after 5 h. Joints displayed graded, non-linear stimulus,response curves to both duration and frequency of movement; 1 min duration per 15 min or a frequency of 0.17 Hz raised HA secretion by 42,54%, while rapid (1.5 Hz) or prolonged cycling (9 min per 15 min) raised it by 110,130%. Movement-stimulated secretion and phorbol ester-stimulated secretion were partly inhibited by the translation inhibitor cycloheximide, by the transcription,translation inhibitors actinomycin D and puromycin and by the Golgi translocation inhibitor brefeldin A. There is thus a graded coupling between HA secretion and cyclic joint movement that depends partly on new protein synthesis. This is likely to be important for joint homeostasis, providing protection during repetitive cycling and potentially contributing to exercise therapy for osteoarthritis. [source]

    Child Weight Status and Young Adult Quality of Life: Is There a Reason for Concern?

    FAMILY & CONSUMER SCIENCES RESEARCH JOURNAL, Issue 1 2008
    Holly S. Kihm
    The purpose of the study was to examine the relationship between child weight status and young adult quality of life. One hundred sixty-four college students participated in the study. Students completed four questionnaires that were used to assess physical and psychosocial variables. Several statistical analyses, including correlations and hierarchal regression models, were employed to test the study's hypotheses. Results from the study showed that child weight status was negatively associated with adult quality of life, and child self-concept was a mediating variable within the relationship. Recognizing the relationship between child weight status and young adult quality of life stresses the importance of addressing psychosocial concerns related to weight status during childhood in efforts to achieve a greater quality of life in adulthood. [source]

    The effects of Daphnia on nutrient stoichiometry and filamentous cyanobacteria: a mesocosm experiment in a eutrophic lake

    FRESHWATER BIOLOGY, Issue 7 2002
    M. J. PATERSON
    1.,Stoichiometric theory predicts that the nitrogen : phosphorus (N : P) ratio of recycled nutrients should increase when P-rich zooplankton such as Daphnia become dominant. We used an enclosure study to test the hypothesis that an increased biomass of Daphnia will increase the relative availability of N versus P sufficiently to decrease the abundance of filamentous cyanobacteria. The experiment was conducted in artificially enriched Lake 227 (L227) in the Experimental Lakes Area (ELA), north-western Ontario, Canada. Previous studies in L227 have shown that the dominance of filamentous, N-fixing cyanobacteria is strongly affected by changes in the relative loading rates of N and P. 2.,We used a 2 × 2 factorial design with the addition or absence of D. pulicaria and high or low relative loading rates of N and P (+NH4, ,NH4) in small enclosures as treatment variables. If Daphnia can strongly affect filamentous cyanobacteria by altering N and P availability, these impacts should be greatest with low external N : P loading rates. The phytoplankton community of L227 was predominantly composed of filamentous Aphanizomenon spp. at the start of the experiment. 3.,Daphnia strongly reduced filamentous cyanobacterial density in all enclosures to which they were added. The addition of NH4 had only a small impact on algal community composition. Hence, we conclude that Daphnia did not cause reductions in cyanobacteria by altering the N : P ratio of available nutrients. 4.,Despite the lack of evidence that Daphnia affected filamentous cyanobacteria by altering the relative availability of N and P, we found changes in nutrient cycling consistent with other aspects of stoichiometric theory. In the presence of Daphnia, total P in the water column decreased because of an increase in P sedimentation. In contrast to P, a decrease in suspended particulate N was offset by an increase in dissolved N (especially NH4). Hence, dissolved and total N : P ratios in the water column increased with Daphnia as a result of differences in the fate of suspended particulate N versus P. There was minimal accumulation and storage of P in Daphnia biomass in the enclosures. 5.,Our experiment demonstrated that Daphnia can strongly limit filamentous cyanobacterial abundance and affect the biogeochemical cycling of nutrients. In our study, changes in nutrient cycling were apparently insufficient to cause the changes in phytoplankton community composition that we observed. Daphnia therefore limited filamentous cyanobacteria by other mechanisms. [source]

    Integration of lakes and streams in a landscape perspective: the importance of material processing on spatial patterns and temporal coherence

    FRESHWATER BIOLOGY, Issue 3 2000
    George W. Kling
    1. We studied the spatial and temporal patterns of change in a suite of twenty-one chemical and biological variables in a lake district in arctic Alaska, U.S.A. The study included fourteen stream sites and ten lake sites, nine of which were in a direct series of surface drainage. All twenty-four sites were sampled between one and five times a year from 1991 to 1997. 2. Stream sites tended to have higher values of major anions and cations than the lake sites, while the lake sites had higher values of particulate carbon, nitrogen, phosphorous and chlorophyll a. There were consistent and statistically significant differences in concentrations of variables measured at the inlet versus the outlet of lakes, and in variables measured at upstream versus downstream sites in the stream reaches which connect the lakes. In-lake processing tended to consume alkalinity, conductivity, H+, DIC, Ca2+, Mg2+, CO2, CH4, and NO3,, and produce K+ and dissolved organic carbon (DOC). In-stream processing resulted in the opposite trends (e.g. consumption of K+ and DOC), and the magnitudes of change were often similar to those measured in the lakes but with the opposite sign. 3. Observed spatial patterns in the study lakes included mean concentrations of variables which increased, decreased or were constant along the lake chain from high to low altitude in the catchment (stream sites showed no spatial patterns with any variables). The strongest spatial patterns were of increasing conductivity, Ca2+, Mg2+, alkalinity, dissolved inorganic carbon and pH with lake chain number (high to low altitude in the basin). These patterns were partly determined by the effect of increasing catchment area feeding into lakes further downslope, and partly by the systematic processing of materials in lakes and in the stream segments between lakes. 4. Synchrony (the temporal coherence or correlation of response) of variables across all lakes ranged from 0.18 for particulate phosphorus to 0.90 for Mg2+ the average synchrony for all twenty-one variables was 0.50. The synchronous behaviour of lake pairs was primarily related to the spatial location or proximity of the lakes for all variables taken together and for many individual variables, and secondarily, to the catchment to lake area ratio and the water residence time. 5. These results illustrate that, over small geographic areas, and somewhat independent of lake or stream morphometry, the consistent and directional (downslope) processing of materials helps produce spatial patterns which are coherent over time for many limnological variables. We combine concepts from stream, lake and landscape ecology, and develop a conceptual view of landscape mass balance. This view highlights that the integration of material processing in both lakes and rivers is critical for understanding the structure and function of surface waters, especially from a landscape perspective. [source]