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Technical Improvements (technical + improvement)
Selected AbstractsA Technical Improvement in Sialendoscopy to Enter the Salivary DuctsTHE LARYNGOSCOPE, Issue 5 2006Cyrille Chossegros MD No abstract is available for this article. [source] Critical review of indications for renal artery stenting: Do randomized trials give the answer?,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 2 2009Uwe Schwarzwälder MD Abstract Significant renal artery stenosis (RAS) is a well accepted cause of deterioration of arterial hypertension and of renal insufficiency. Just recently, more interest has been focused on the impact of RAS on structural heart disease and patient survival. Technical improvements of diagnostic and interventional endovascular tools have lead to a more widespread use of endoluminal renal artery revascularization and extension of the indications for this type of therapy during the past 2 decades. Since the first renal artery angioplasties performed by Felix Mahler and Andreas Grüntzig, numerous single centre studies have reported the beneficial effect of percutaneous transluminal renal angioplasty, and since the early 1990's stenting of renal artery stenosis caused either by atherosclerosis or fibromuscular dysplasia. However, none of the so far published or presented randomized controlled trials (RCT) could prove a beneficial outcome of RAS revascularization compared with medical management. As a result of these negative trials including the recently presented ASTRAL trial, referrals to endovascular renal artery revascularization went down and moreover, reimbursement of these procedures became a matter of debate. This article summarizes the background and the limitations of the so far published and still ongoing controlled trials. Moreover, we discuss why well-designed registries might give important insight on the impact of endovascular revascularization of hemodynamically relevant atherosclerotic RAS. © 2009 Wiley-Liss, Inc. [source] Carotid artery stenting: Do procedural complications relate to the side intervened upon?,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 1 2009Registry of the Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte (ALKK), Results From the Carotid Artery Stent (CAS) Abstract Objectives: To determine the influence of the side intervened upon on outcomes during carotid artery stenting (CAS). Background: Anatomic and technical aspects may influence the results of CAS. The value of the side intervened upon has not been analyzed yet. Methods: We analyzed data from the Carotid Artery Stent (CAS) , Registry.Results: A total of 3,165 CAS procedures, 1,613 (51%) at the left and 1,552 (49%) at the right carotid artery were included. There was a higher proportion of patients treated for symptomatic stenoses when CAS was performed at the left carotid artery (50.1% versus 45.8%, P = 0.016) and more patients already had prior carotid endarterectomy (8.5% versus 5.8%, P = 0.003). Interventions at the left side took 3 min longer than interventions at the right side (46.6 ± 24.3 versus 43.8 ± 23.6, P = 0.003). In patients treated at the left carotid artery amaurosis fugax (0.7% versus 0.1%, P = 0.005), ipsilateral stroke (3.1% versus 1.8%, P = 0.017), and the primary endpoint of in-hospital death or stroke (4.1% versus 2.3%, P = 0.005) occurred significantly more often. Even after adjusting for confounding parameters, CAS procedures performed at the left carotid arteries remained an independent predictor of death or stroke (OR = 1.77, 95% CI: 1.15,2.72, P = 0.009). Conclusions: In current clinical practice, CAS is performed frequently at the right carotid artery as at the left carotid artery. CAS interventions have a higher in-hospital complication rate if performed at the left carotid artery. Technical improvements might help to overcome this situation. © 2009 Wiley-Liss, Inc. [source] Testing automated liquid-based cytology samples with a manual liquid-based cytology method using residual cell suspensions from 500 ThinPrep casesDIAGNOSTIC CYTOPATHOLOGY, Issue 6 2006John A. Maksem M.D. Abstract We report a technical improvement upon a previously disclosed manual liquid-based cytology (MLBC) method; and, we use the improved method to prepare slides from residual ThinPrep specimens in order to see how often ThinPrep diagnoses correspond to diagnoses derived from exhaustive examination of their parent sample suspensions. Residual cell suspensions from 500 ThinPrep cases comprising (1) 20 low-grade squamous intraepithelial lesions (LSILs); (2) 200 high risk (HR) negatives and 20 ASC-US; and (3) 260 screening cytology specimens were studied. Institutional review committee guidelines allowed us to know diagnoses by groups of specimens, but did not allow us to know individual patient diagnoses, so we could not perform case-by-case matched outcome-comparisons. Cells were concentrated by conventional centrifugation and sedimented into a polymer gel that was then vortex-mixed and converted into a viscous cell-rich suspension. The cell suspension was smeared between two clean glass slides, which were air-dried and stained with the Papanicolaou stain. Two study-sets were created, comprising one slide from each case. Each of the two study sets was examined by two cytopathologists, and discordant diagnoses were adjudicated. Because of the ambiguity involved in the "atypical" (ASC-US, ASC-H, AGC) diagnosis categories, only outcomes at the level of LSIL or greater were recorded. All MLBC SILs were digitally imaged and abnormal slides plus digital images were sent to the laboratory that provided the residual automated liquid-based cytology (ALBC) suspensions. The final diagnoses were confirmed by the laboratory that provided the residual ALBC specimens. MLBC slides of the 20 LSIL cases afforded 2 high-grade squamous intraepithelial lesions (HSILs) and 18 LSILs. Those of the 200 HR-Negatives showed 3 HSILs and 30 LSILs; and those of the 20 HR-ASC-US showed 3 HSILs and 9 LSILs. MLBC slides of the 260 screening cytology specimens showed 1 Carcinoma, 3 HSILs and 20 LSILs; affording 3 HSILs and 14 LSILs more than originally diagnosed. The MLBC method of this report is useful for preparing cell suspensions for cytological examination. Our analytical method was exhaustive and used nearly all of the cell material that was provided to us for analysis; therefore, we conclude that this approach is useful for determining how well ALBC instruments represent their parent sample suspensions. It appears that "rare events" may be overlooked when limited sample aliquots are analyzed by ALBC instruments, and this probably accounts for our increased discovery of SILs by the MLBC method. Also, SILs often present as aggregates of cohesive cells which, if overlooked or ineffectively transferred to ALBC slides, would not be diagnosed. Diagn. Cytopathol. 2006;34:391,396. © 2006 Wiley-Liss, Inc. [source] Antireflux stents for palliation of malignant esophagocardial stenosisDISEASES OF THE ESOPHAGUS, Issue 2 2007K. Schoppmeyer SUMMARY., Placement of self-expanding metal stents (SEMS) for palliation of malignant stenoses at the gastroesophageal junction is often associated with stent migration and reflux symptoms. SEMS with an antireflux mechanism have been developed to overcome the latter problem. The aim of this study was to evaluate the safety and efficacy of antireflux Z-stents. Patients with advanced squamous cell or adenocarcinoma of the distal esophagus or cardia suffering from dysphagia received an antireflux Z-stent. Technical success, complications of the procedure, clinical symptoms before and after stent placement, reinterventions and survival were recorded. Follow-up was accomplished by patient interviews and a standardized questionnaire for primary care physicians. Eighteen consecutive patients received an antireflux Z-stent. Seventeen of 18 stents were placed technically successful in a single endoscopic procedure. Mean dysphagia score improved from 2.2 to 0.6. Four patients (22%) had permanent reflux symptoms, an additional nine (50%) were taking proton pump inhibitors on a regular basis. In 10 patients, a re-intervention was necessary mainly due to dislocation of the stent. To ensure adequate nutrition three and two patients received a percutaneous gastrostomy and a jejunostomy, respectively. Median survival from stent insertion was 54 days (range, 3,201). Although placement of an antireflux Z-stent is technically feasible, its application is hampered by frequent stent migration and insufficient prevention of gastroesophageal reflux. Further technical improvements of stents or alternative methods like brachytherapy are required for satisfactory palliation of malignant gastroesophageal stenosis. [source] Neutron Activation Analysis, Atomic Absorption and X-Ray Fluorescence Spectrometry Review for 2006,2007GEOSTANDARDS & GEOANALYTICAL RESEARCH, Issue 4 2008L. Paul Bédard These mature analytical techniques do not show any change in publication level from the previous two years and AAS remains dominant in terms of the number of publications. The last two years have seen fewer technical improvements than in the previous review period. Some interesting papers dealing with uncertainty and quality assurance in INAA were published during 2006,2007. It is suggested that photon activation should be reconsidered because the source of electron accelerators has recently improved. A technique to preconcentrate Se for INAA determination has also been proposed. In the case of AAS, papers on analyte preconcentration continue to be more abundant than those relating to instrumental modification. Sample preparation for AAS is also active and ultrasound-assisted leaching shows some promising applications. There were an unusual number of reviews concerned with AAS and those important to geological samples are cited here. A technique to preconcentrate Cr in water is presented and a new device to determine As and Se is showing some potential uses. Confocal X-ray mapping continues to show interesting developments. One group developed a technique to perform XRF inside an oyster and an interesting application of ,-XRF mapping of sediments is presented. Determination of platinum-group elements (at ,g g1 concentrations) can be carried out very quickly with an improved XRF technique. [source] Multicenter quality control of the detection of HIV-1 genome in semen before medically assisted procreationJOURNAL OF MEDICAL VIROLOGY, Issue 7 2006Christophe Pasquier Abstract Couples in whom the man is HIV-1-positive may use medically assisted procreation in order to conceive a child without contaminating the female partner. But, before medically assisted procreation, the semen has to be processed to exclude HIV and tested for HIV nucleic acid before and after processing. The performance was evaluated of the technical protocols used to detect and quantify HIV-1 in 11 centers providing medically assisted procreation for couples with HIV-1 infected men by testing panels of seminal plasma and cells containing HIV-1 RNA and/or DNA. The performance of these tests varied due to the different assays used. False positive results were obtained in 14,19% of cases. The sensitivity for RNA detection in seminal plasma was 500,1,000 RNA copies/ml, over 500 RNA copies/106 cells in semen cells, and for DNA detection in semen cells 50,500 DNA copies/106 cells. The use of silica-based extraction seemed to increase the assay performance, whereas the use of internal controls to detect PCR inhibitor did not. This first quality control highlights the need for technical improvements of the assays to detect and quantify HIV in semen fractions and for regular evaluation of their performance. J. Med. Virol. 78:877,882, 2006. © 2006 Wiley-Liss, Inc. [source] Systematic review: caspase-cleaved fragments of cytokeratin 18 , the promises and challenges of a biomarker for chronic liver diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 11-12 2009Y. YILMAZ Summary Background, Biomarkers hold great promise for detecting chronic liver disease without the use of liver biopsy. Aim, To review the usefulness of cytokeratin (CK) 18 fragments, a marker of hepatocyte apoptosis, to predict the presence of chronic liver injury. Methods, Available literature identified from PubMed was reviewed. Results, Levels of CK18 fragments have been shown to be elevated in hepatocellular carcinoma, viral hepatitis, alcoholic hepatitis, nonalcoholic fatty liver disease and cholestatic liver disease. In the setting of nonalcoholic fatty liver disease, CK18 fragments may distinguish nonalcoholic steatohepatitis from simple fatty liver. Conclusions, Undoubtedly, the most promising application of CK18 fragments is currently in nonalcoholic fatty liver disease, and especially for distinguishing patients with nonalcoholic steatohepatitis vs. those with simple steatosis. Further investigations and technical improvements are required to cross the boundary from research to the clinical application of CK18 fragments as a marker of chronic liver disease. [source] Atrial Linear Lesions: Feasibility Using CryoablationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2006KLAUS KETTERING Background: Long linear lesions are created in the left atrium to modify the atrial substrate, thereby curing atrial fibrillation. The creation of long linear left atrial lesions using radiofrequency (RF) ablation is time consuming and difficult. Furthermore, it might result in significant complications. Cryoablation might overcome some of the disadvantages of RF ablation. Therefore, the aim of our study was to assess whether the creation of a long linear lesion is possible using cryotherapy. Methods: A right atrial septal linear lesion was created in six pigs (median weight: 50 kg; range: 40,60 kg). The ablation procedure was performed with a 7-F Freezor cryocatheter. The nonfluoroscopic mapping system LocaLisa was used as a navigation tool. At each point, freezing was maintained at the lowest attainable temperature (,75°C) for 4 minutes. The CARTO system was used for the evaluation of the linear lesions. Furthermore, all animals were sacrificed immediately after the ablation procedure and a postmortem examination of the lesions was performed. Additionally, an analysis of the amplitudes of the intracardiac electrograms registered via the ablation catheter was performed before and after the ablation procedure. Results: A right atrial septal linear lesion could be created successfully in all six pigs. For the performance of this ablation line, a median number of 16 cryoapplications (range, 11,26) was necessary. The amplitudes of the intracardiac electrograms registered via the ablation catheter decreased significantly after ablation. The CARTO bipolar voltage map revealed very low potentials along the ablation line and showed a sharply demarcated ablation area at the septum in all pigs. Further analysis of the CARTO map revealed an incomplete conduction block in all cases. Most of the pigs had a small gap close to the fossa ovalis. The postmortem examination of 2,3,5-triphenyl-tetrazolium chloride-stained specimens showed sharply demarcated lesions without any ulcerations. There were no major complications during the procedure. Conclusions: The creation of long linear lesions using cryoablation is feasible and safe. Lesion characteristics are different and more favorable than those created by RF. However, the aim of creating a transmural lesion and a complete conduction block remains an unsolved problem even with current cryoablation techniques. Nevertheless, growing experience and technical improvements might overcome some of the current limitations of this new technique. [source] Popliteal artery injury: Royal Perth experience and literature reviewANZ JOURNAL OF SURGERY, Issue 10 2005Mazri M. Yahya Background: Popliteal artery injury is uncommon but poses a significant challenge in Australian trauma care. Blunt trauma and knee dislocations appear to be associated with higher amputation rates. The aim of the present study was to review the authors' experience with this condition and discuss the best approach to investigation and management. Methods: The medical records of all patients with popliteal artery injury (n = 19) who were entered prospectively onto the Royal Perth Hospital Trauma Registry from 1995 to 2003 were reviewed. Their demographic data, investigations, primary operative procedures, fasciotomy, primary and secondary amputation rates and mortality were determined. Results: There were 17 male and two female patients with a median age of 34 years (range 17,62 years). Most patients (84%) were under 40 years in age. Blunt trauma was the commonest cause of popliteal artery injury (68.4%), and 84.6% of the patients had associated skeletal injury. The amputation rate in the present study was 26.3% (5/19). There were no intraoperative or in-hospital deaths. Three of 13 patients (23%) with blunt trauma underwent amputation, compared to two of six (33.3%) with penetrating injury. Two of three amputee patients in the blunt trauma group had dislocated knees. Conclusion: Despite technical improvements in management of popliteal artery injury, a high amputation rate is still seen, especially in patients with one or more of the following factors: extensive soft-issue injury, associated skeletal trauma, knee dislocation, and prolonged ischaemia time. Measures to reduce the amputation rate, ranging from more prompt diagnosis to modified surgical treatment techniques, are discussed. [source] High-resolution X-ray crystal structure of bovine H-protein at 0.88,Å resolutionACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2010Akifumi Higashiura Recent technical improvements in macromolecular X-ray crystallography have significantly improved the resolution limit of protein structures. However, examples of high-resolution structure determination are still limited. In this study, the X-ray crystal structure of bovine H-protein, a component of the glycine cleavage system, was determined at 0.88,Å resolution. This is the first ultrahigh-resolution structure of an H-protein. The data were collected using synchrotron radiation. Because of limitations of the hardware, especially the dynamic range of the CCD detector, three data sets (high-, medium- and low-resolution data sets) were measured in order to obtain a complete set of data. To improve the quality of the merged data, the reference data set was optimized for merging and the merged data were assessed by comparing merging statistics and R factors against the final model and the number of visualized H atoms. In addition, the advantages of merging three data sets were evaluated. The omission of low-resolution reflections had an adverse effect on visualization of H atoms in hydrogen-omit maps. Visualization of hydrogen electron density is a good indicator for assessing the quality of high-resolution X-ray diffraction data. [source] Comparison of synovial tissues from the knee joints and the small joints of rheumatoid arthritis patients: Implications for pathogenesis and evaluation of treatmentARTHRITIS & RHEUMATISM, Issue 8 2002Maarten C. Kraan Objective Serial synovial biopsy samples are increasingly being used for the evaluation of novel therapies for rheumatoid arthritis (RA). Most studies have used tissues from knee biopsies, but technical improvements have made serial small joint arthroscopy feasible as well. Theoretically, there could be differences in the features of synovial inflammation between various joints as a result of mechanical factors, differences in innervation, and other factors. We therefore undertook this study to compare the cell infiltrate in paired synovial biopsy samples from inflamed knee joints and paired inflamed small joints of patients with RA. Methods Nine RA patients with both an inflamed knee joint and an inflamed small joint (wrist or metacarpophalangeal joint) underwent an arthroscopic synovial biopsy of both joints on the same day. Multiple biopsy specimens were collected and stained for macrophages, T cells, plasma cells, fibroblast-like synoviocytes, and interleukin-6 (IL-6) by immunohistochemistry. Sections were evaluated by digital image analysis. Results There were no significant differences in mean cell numbers for all markers investigated in samples from the knee joint compared with samples from the small joints. We detected statistically significant correlations for the numbers of sublining macrophages, T cells, and plasma cells, as well as for IL-6 expression, between the knee joint and the small joints. However, there was no significant correlation between different joints for the numbers of intimal macrophages or fibroblast-like synoviocytes. Conclusion The results of this study show that the inflammation in one inflamed joint is generally representative of that in other inflamed joints. Therefore, it is possible to use serial samples from the same joint, selecting either large or small joints, for the evaluation of antirheumatic therapies. [source] Sources of Growth and Structural Change in the Vietnamese Economy, 1996,2003: A Computable General Equilibrium Analysis,ASIAN ECONOMIC JOURNAL, Issue 2 2009James A. Giesecke C68; D58; F14; O12 We use the MONASH-VN model, a dynamic computable general equilibrium model of the Vietnamese economy, to investigate Vietnam's rapid growth and structural change over the period 1996 to 2003. We do this in two steps. First, we estimate changes in variables representing production technologies, consumer preferences, government policy and other structural features of the economy. Movements in these structural and policy variables are then used to explain the recent history of Vietnam's rapid growth and structural change. We find the most important sources of growth and change to be technical improvements, favorable shifts in foreign demand for Vietnamese goods and employment growth. Other important factors include movement in household preferences away from primary products and towards manufactures and services, expansion in agricultural land supply, and tax reform. [source] Laparoscopic colorectal cancer surgery: Japanese experienceASIAN JOURNAL OF ENDOSCOPIC SURGERY, Issue 2 2009F Konishi Abstract In Japan, laparoscopic colectomy for cancer started in 1992. A national survey has revealed that, since that time, the number of cases that have undergone this procedure has steadily increased, and by 2007, there were over 9000 cases. This figure includes an increase in the percentage of more advanced cases, which has occurred due to technical improvements in lymph node dissection. A Japanese randomized controlled trial comparing laparoscopic to open surgery started in November 2004, with enrollment ending in April 2009 with 1050 cases. For this study, preoperative stage T3 and T4 cases were selected for inclusion, and D3 dissection was required. To assess the technical skill of surgeons, the Japan Society of Endoscopic Surgery established the Endoscopic Surgical Skill Qualification System to encourage high-level surgical techniques. Assessment is conducted by reviewing unedited videos. The success rate for colon and rectal surgeries has ranged between 37%,40%. The Endoscopic Surgical Skill Qualification System has contributed to the establishment of standard technical skills in laparoscopic surgery, the development of an educational system for laparoscopic surgeons, and a reduction in the number complications. Technical difficulties still exist in laparoscopic rectal cancer surgery, but with the technical progress in laparoscopic colorectal surgery, the number of laparoscopic rectal cancer surgeries has been gradually increasing in number. A multicentric phase II study on the feasibility and long-term outcome for stage I and II rectal cancer started in 2008. In this study, the short-term outcomes including anastomotic leakage rate and long-term survival, will be clarified. Combined with continuously improved technologies, training techniques and surgical standards, laparoscopic colorectal surgery is steadily progressing in Japan. [source] Evaluation of findings during re-exploration for obstructive ileus after radical cystectomy and ileal-loop urinary diversion: insight into potential technical improvementsBJU INTERNATIONAL, Issue 4 2007Ioannis M. Varkarakis Authors from Greece evaluated their experience of findings during re-exploration for small bowel obstruction after radical cystectomy. They found several abnormalities, more particularly unexpected, to account for this, and drew some conclusions as to the operative technique that might help to prevent them. OBJECTIVE To retrospectively evaluate the findings during re-exploration for obstructive ileus after radical cystectomy (RC) and ileal conduit diversion. PATIENTS AND METHODS During a 12-year period, 434 patients who had RC and ileal conduit diversion were retrospectively evaluated for the diagnosis of early (,30 days after RC) or late abdominal re-exploration. The operative reports of patients requiring a second abdominal procedure were reviewed, evaluating in particular the reason for small bowel obstruction (SBO). In addition, the type of entero-enteric anastomosis and the retroperitonealization of the uretero-enteric anastomosis were compared between patients who required abdominal re-exploration for SBO and those who did not. RESULTS Abdominal re-exploration for SBO was necessary for 14 (3.2%) and 32 (7.3%) patients in the early and late postoperative period, respectively. The most common reasons for SBO were anastomotic malfunction (1.4%) and malignant recurrence (2.8%). Adhesions were the second most common cause leading to ileus in both periods (1.1% and 2.3%, respectively). When there was no retroperitonealization of the uretero-enteric anastomosis, SBO occurred more often both early and late (P = 0.06). Early anastomotic malfunction leading to SBO was more common (but not statistically significant, P = 0.06) when the entero-enteric anastomosis was hand-sutured end-to-end. CONCLUSIONS Anastomotic malfunction, bowel adhesions and internal hernias are responsible for SBO early after surgery. The above reasons, in addition to malignant recurrence, are the most common reasons for SBO in the late postoperative period. [source] Ophthalmic imaging today: an ophthalmic photographer's viewpoint , a reviewCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 1 2009Timothy J Bennett FOPS Abstract Ophthalmic imaging has changed dramatically since the 1960s with increasingly complex technologies now available. Arguably, the greatest changes have been the development of the digital camera and the speed, processing power and storage of electronic data. Already, ophthalmic practices in many major institutions overseas have paperless medium storage and electronically generated reporting from all equipment that use a computer interface. It is hard to remember the widespread use of photographic film with its attendant costs, or even to remember the days before optical coherence tomography (OCT). These latest technical improvements in ophthalmic imaging are now standard in large Australian institutions and becoming more widespread in smaller private practices. The technicians that operate and maintain this ever-increasing plethora of gadgetry have seen their work practices change from the darkroom to the complexities of data-based imaging and storage. It is a fitting time to examine the contemporary state of ophthalmic imaging and what lies on the horizon as we move towards 2020. [source] | ||||||||||||||||||||||