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Excellent Method (excellent + method)
Selected AbstractsChemInform Abstract: An Excellent Method for Cbz-Protection of Amines.CHEMINFORM, Issue 32 2010Khiangte Vanlaldinpuia Abstract The method is simple, does not require aqueous work-up and gives excellent yields. [source] Poly(methacrylic acid-ethylene glycol dimethacrylate) monolith in-tube solid-phase microextraction applied to simultaneous analysis of some amphetamine derivatives in urine by capillary zone electrophoresisELECTROPHORESIS, Issue 16 2005Fang Wei Abstract A method based on in-tube solid-phase microextraction and capillary zone electrophoresis (CZE) was proposed for simultaneously determining four amphetamines (amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, and 3,4-methylenedioxymethamphetamine) in urine. A poly(methacrylic acid-ethylene glycol dimethacrylate) monolithic capillary column, which can provide sufficient extraction efficiency, was introduced for the extraction of amphetamines from urine samples. The hydrophobic main chains and acidic pendant groups of the monolithic column make it a superior material for extraction of basic analytes from aqueous matrix. After extraction, the samples were analyzed by CZE. The best separation was achieved using a buffer composed of 0.1,M disodium hydrogen phosphate (adjusted to pH,4.5 with 1,M hydrochloric acid) and 20% methanol v/v, with a temperature and voltage of 25°C and 20,kV, respectively. By applying electrokinetic injection with field-amplified sample stacking, detection limits of 25,34,µg/L were achieved. Excellent method of reproducibility was found over a linear range of 0.1,5,mg/L. Determination of these analytes from abusers' urine sample was also demonstrated. [source] Utility of a Bilayered Banner Transposition Flap in Reconstruction of the Lower Third of the PinnaDERMATOLOGIC SURGERY, Issue 7 2000Dania Tannir MD Background. Reconstruction of the entire ear lobule is challenging and complex. We present a case in which a banner transposition flap from the preauricular and mandibular area of the cheek resulted in an excellent cosmetic outcome. Objective. To demonstrate the utility of a bilayered banner transposition flap to reconstruct a full-thickness defect of the inferior one-third of the pinna. Methods., The technique employed in this reconstruction is described and previously reported techniques are reviewed. Results., A symmetrical earlobe with normal tissue consistency was created, as noted at 4 months postoperatively. Conclusion. Utilization of a banner transposition flap should be considered as an excellent method for reconstruction of full-thickness defects of the lower one-third of the ear. [source] Coupling Capillary Electrophoresis and Pulsed Electrochemical DetectionELECTROANALYSIS, Issue 13 2005Carlos Abstract Pulsed electrochemical detection (PED) is an excellent method for detection of analytes that normally foul electrodes. In PED, the detection electrode is first cleaned at a high positive potential, then reactivated at a negative potential dissolving the surface oxide, and finally used to oxidize the analyte at a moderate positive potential. Due to the advantages and versatility of PED, many different variations of the detection waveform can be found in literature. This review focuses on application of PED to CE and in particular, the most commonly used modes: pulsed amperometric detection (PAD) and integrated pulsed amperometric detection (iPAD). [source] Comparison of Intrinsic Optical Signals Associated with Low Mg2+, and 4-Aminopyridine,Induced Seizure-Like Events Reveals Characteristic Features in Adult Rat Limbic SystemEPILEPSIA, Issue 6 2000Katharina Buchheim Summary: Purpose: To analyze the intrinsic optical signal change associated with seizure-like events in two frequently used in vitro models,the low-Mg2+ and the 4-aminopyridine (4-AP) models,and to monitor regions of onset and spread patterns of these discharges by using imaging of intrinsic optical signals (IOS). Methods: Combined hippocampal,entorhinal,cortex slices of adult rats were exposed to two different treatments: lowering extracellular Mg2+ concentrations or application of 100 ,M 4-AP. The electrographic features of the discharges were monitored using extracellular microelectrodes. Optical imaging was achieved by infrared transillumination of the slice and analysis of changes in light transmission using a subtraction approach. The electrographic features were compared with the optical changes. Regions of onset and spread patterns were analyzed in relevant anatomic regions of the slice. Results: Both lowering extracellular Mg2+ concentrations and application of 4-AP induced seizure-like events. The relative duration of the intrinsic optical signal change associated with seizure-like events in the low-Mg2+ model was significantly longer compared with that seen with those occurring in the 4-AP model, although duration of field potentials did not differ significantly in the two models. Seizure-like events of the low-Mg2+ model originated predominantly in the entorhinal cortex, with subsequent propagation toward the subiculum and neocortical structures. In contrast, no consistent region of onset or spread patterns were seen in the 4-AP model, indicating that the seizure initiation is not confined to a particular region in this model. Conclusions: We conclude that different forms of spontaneous epileptiform activity are associated with characteristic optical signal changes and that optical imaging represents an excellent method to assess regions of seizure onset and spread patterns. [source] Dynamic T1-weighted monitoring of vascularization in human carcinoma heterotransplants by magnetic resonance imaging,INTERNATIONAL JOURNAL OF CANCER, Issue 1 2003Fabian Kiessling Abstract Studies on tumor angiogenesis and antiangiogenic therapies are commonly performed with tumor heterotransplants in nude mice. To monitor therapeutic effects, improved noninvasive analyses of functional data are required, in addition to the assessment of tumor volume and histology. Here, we report on sequential monitoring of vascularization of human squamous cell carcinomas growing as heterotransplants in nude mice using MRI. Using a custom-developed animal coil in a conventional whole-body 1.5 T MRI scanner, dynamic T1w sequences were recorded after i.v. injection of Gd-DTPA in tumors grown for 17, 21, 25, 29 and 33 days. Amplitude and the exchange rate constant (kep) were calculated according to a 2-compartment model, discriminating intravascular and interstitial spaces, and correlated with tumor size and histology. High-resolution imaging of small heterotransplants from 100 to 1,000 mm3 was achieved, clearly discriminating vital and necrotic areas. Preceding the development of necroses, which were hyperintense in T2w images and confirmed with histology, a local decrease of amplitude and kep values was observed. Significantly higher amplitudes were found in tumor periphery than in central parts, correlating well with the vascular pattern obtained by immunocytochemistry. Tumor size correlated negatively with amplitude, probably as a result of increasing necrotic areas, whereas the reason for the observed increase of kep value with tumor size remains unclear. These data demonstrate that dynamic MRI is an excellent method for noninvasive assessment of tumor vascularization in small animals using a clinical whole-body scanner with little technical modifications. This technique provides functional data characterizing essential features of tumor biology and is thus appropriate for monitoring antiangiogenic therapies. © 2002 Wiley-Liss, Inc. [source] Duplex Doppler sonography of transplant renal artery stenosisJOURNAL OF CLINICAL ULTRASOUND, Issue 3 2003Ruth Helena de Morais MD Abstract Purpose The aim of this study was to evaluate the accuracy of duplex Doppler sonography in diagnosing transplant renal artery stenosis (TRAS) and to determine which parameter is the most reliable for making that diagnosis. Methods Over a 3-year period, we sonographically evaluated patients who were referred for investigation of possible TRAS. We investigated the following parameters: peak systolic velocity (PSV) in the external iliac and renal arteries, acceleration time and acceleration in the intrarenal arteries, acceleration time in the renal artery, resistance index, and the ratio of the PSVs in the renal and external iliac arteries. We also used MR angiography and digital subtraction arteriography to verify the degree of stenosis. After the evaluations, the patients were classified into 2 groups, 1 with and the other without significant stenosis (> 50% narrowing of the lumen) on digital subtraction arteriography. We also included a control group of patients who had undergone renal transplantation at least 6 months before, had had a good course after transplantation, had a diastolic blood pressure of 90 mm Hg or less, and were taking a maximum of 1 antihypertensive drug. Results Our study population consisted of 22 patients suspected to have TRAS (10 without and 12 with confirmed significant stenosis) and 19 control patients. We found statistically significant differences between the mean values of these 3 groups except for the PSV in the iliac artery and the resistance index in the intrarenal arteries. The most accurate parameters to use in diagnosing TRAS were an acceleration time of 0.1 second or higher in the renal and intrarenal arteries, a PSV of greater than 200 cm/second in the renal artery, and a ratio of PSVs in the renal and external iliac arteries of greater than 1.8. Conclusions Duplex Doppler sonography is an excellent method for screening patients suspected to have TRAS and can help select which of those patients should undergo digital subtraction arteriography. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:135,141, 2003 [source] Clinical two-photon microendoscopyMICROSCOPY RESEARCH AND TECHNIQUE, Issue 5 2007K. König Abstract Two-photon medical imaging has found its way into dermatology as an excellent method for noninvasive skin cancer detection without need of contrast agents as well as for in situ drug screening of topically-applied cosmetical and pharmaceutical components. There is an increasing demand to apply the multiphoton technology also for deep-tissue skin imaging as well as for intracorporal imaging. We report on the first clinical use of multiphoton endoscopes, in particular of a miniaturized rigid two-photon GRIN lens endoscope. The microendoscope was attached to the multiphoton tomograph DermaInspect and employed to detect the extracellular matrix proteins collagen and elastin in the human dermis of volunteers and patients with ulcera by in vivo second harmonic generation and in vivo two-photon autofluorescence. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. [source] Non-radioactive in situ detection of mRNA in ES cell-derived cardiomyocytes and in the developing heartMICROSCOPY RESEARCH AND TECHNIQUE, Issue 5 2002Arnoud C. Fijnvandraat Abstract Non-radioactive in situ hybridisation is an excellent method to visualise mRNA molecules within their topographical context. Recently we have reported a new non-radioactive in situ hybridisation procedure on tissue sections that is essentially based on the whole mount in situ hybridisation procedure. This method is superior in spatial resolution and sensitivity compared to the radioactive in situ hybridisation procedure. Generally, low levels of gene expression, such as found with the developmental onset of gene expression and in differentiating embryonic stem cells, are difficult to detect by in situ hybridisation. Here an application of the protocol is presented which is based on tyramide signal amplification, which enables the detection of very low abundant mRNAs. The significance of this method is two-fold: (1) the molecular phenotype of embryonic stem cell-derived cardiomyocytes can be examined at the cellular level with high sensitivity, and (2) the number of cells that express the gene of interest can be assessed. Microsc. Res. Tech. 58:387,394, 2002. © 2002 Wiley-Liss, Inc. [source] Assessment of the patency of microvascular anastomoses using microscope-integrated near-infrared angiography: A preliminary studyMICROSURGERY, Issue 7 2009Charlotte Holm M.D., Ph.D. Background: Technical problems at the site of the anastomosis compromise an underappreciated proportion of microsurgical free tissue transfers. Intraoperative identification of technical errors may be able to prevent reexploration surgery and early flap failure. We report the first human study on a new microscope-integrated fluorescence angiography technique, which allows for intraoperative imaging of the anastomotic site. Methods: Fifty consecutive patients undergoing reconstructive microsurgical procedures were enrolled in the study. Intraoperative near infrared indocyanine green videoangiography (ICGA) was performed on all microsurgical anastomoses, after they had been assessed by the operating surgeon by conventional clinical patency tests. Anastomoses deemed to be occluded by the ICG-angiography were intraoperatively revised, and the result of revision was compared with angiographic findings. Results: In 11/50 (22%) of patients, where the surgeon had classified the anastomoses as patent, microangiography identified a total luminal occlusion (six) and/or significant alterations in blood flow (five), potentially predisposing toward postoperative flap failure. Intraoperative revision confirmed angiographic findings in 100% of cases, and was always associated with flap survival. The decision not to revise despite anastomotic occlusion by the intraoperative angiogram was always followed by flap loss or early reexploration. A delayed return of venous blood from the flap predisposed toward postoperative flap failure. Conclusions: Hand-sewn anastomoses are subject to technical errors, and conventional patency tests have a low sensitivity for revealing anastomotic failure. Microscope integrated microangiography is an excellent method for identifying significant anastomotic problems, which would have otherwise gone unnoticed. The potential impact on early flap failure and reexploration surgery is considerable. © 2009 Wiley-Liss, Inc. Microsurgery 2009. [source] Simultaneous quantitative determination of cyclosporine A and its three main metabolites (AM1, AM4N and AM9) in human blood by liquid chromatography/mass spectrometry using a rapid sample processing methodRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2006Nozomu Koseki We have developed a sensitive and specific liquid chromatography/mass spectrometry (LC/MS) method for the simultaneous determination of cyclosporine A (CsA) and its three main metabolites (AM1, AM4N and AM9) in human blood. Following protein precipitation, supernatant was directly injected into the LC/MS system. Chromatographic separation was accomplished on a Symmetry C8 (4.6,×,75,mm, 3.5,µm) column with a linear gradient elution prior to detection by atmospheric pressure chemical ionization (APCI) MS using selected ion monitoring (SIM) in positive mode. This method can be applied to single mass equipment. The analytical range for each analyte was set at 1,2500,ng/mL using 100,µL of blood sample. The analytical method was fully validated according to FDA guidance. Intra-day mean accuracy and precision were 95.2,113.5% and 0.9,8.9%, respectively. Inter-day mean accuracy and precision were 95.8,107.0% and 1.5,10.7%, respectively. In blood all analytes were stable during three freeze/thaw cycles, for 24,h at room temperature and for 12 months at or below ,15°C. Stability was also confirmed in processed samples for 24,h at 10°C and for 6 months at 4°C in methanol. In addition, we confirmed the method could avoid matrix effects from transplant subjects' samples. This LC/MS technique provided an excellent method for simultaneous quantitative determination of CsA and its three metabolites for evaluation of their pharmacokinetic profiles. Copyright © 2006 John Wiley & Sons, Ltd. [source] SARS: clinical virology and pathogenesisRESPIROLOGY, Issue 2003John NICHOLLS Severe acute respiratory syndrome (SARS) is caused by a novel coronavirus, called the SARS coronavirus (SARS-CoV). Over 95% of well characterized cohorts of SARS have evidence of recent SARS-CoV infection. The genome of SARS-CoV has been sequenced and it is not related to any of the previously known human or animal coronaviruses. It is probable that SARS-CoV was an animal virus that adapted to human-human transmission in the recent past. The virus can be found in nasopharyngeal aspirate, urine and stools of SARS patients. Second generation reverse transcriptase polymerase chain reaction assays are able to detect SARS-CoV in nasopharyngeal aspirates of approximately 80% of patients with SARS within the first 3 days of illness. Seroconversion for SARS-CoV using immunofluorescence on infected cells is an excellent method of confirming the diagnosis, but antibody responses only appear around day 10 of the illness. Within the first 10 days the histological picture is that of acute phase diffuse alveolar damage (DAD) with a mixture of inflammatory infiltrate, oedema and hyaline membrane formation. Desquamation of pneumocytes is prominent and consistent. After 10 days of illness the picture changes to one of organizing DAD with increased fibrosis, squamous metaplasia and multinucleated giant cells. The role of cytokines in the pathogenesis of SARS is still unclear. [source] Feasibility and Outcome of Endoscopic Staple-Assisted Esophagodiverticulostomy for Zenker's Diverticulum,THE LARYNGOSCOPE, Issue 9 2001Erica R. Thaler MD Abstract Objectives/Hypothesis Endoscopic staple-assisted esophagodiverticulostomy (ESED) is a newly described method of surgically correcting Zenker's diverticulum. Initial reports on the ease and success of the surgery have been quite enthusiastic, making it seem the procedure of choice. We initiated the procedure in an algorithm of treatment of Zenker's diverticulum, to further explore the feasibility and outcome of this new technique. Study Design This is a case series of 23 patients with Zenker's diverticulum who have undergone surgical repair. For each patient, an attempt at ESED was made. If unsuccessful, an open approach was then taken. Results Seven of 23 patients (30%) were unable to be treated with ESED because of inability to expose the diverticulum or unfavorable anatomy of the diverticulum itself. Of the remaining 16 patients, ESED was successful in resolving the symptoms of diverticulum in 14 (87%). Two patients (13%) were somewhat improved but had persistent dysphagia. No significant complications occurred. All patients resumed oral diet within the first 24 hours after surgery. Conclusion Esophagodiverticulostomy is an excellent method of surgically correcting Zenker's diverticulum in many patients, but anatomical considerations may prevent its use, making open approaches of continued importance in a surgeon's armamentarium. [source] Evidence for downregulation of calcium signaling proteins in advanced mouse adenocarcinomaTHE PROSTATE, Issue 2 2005Viola C. Ruddat Abstract BACKGROUND Prostate cancer (PCa) is the leading cancer related death in America. Gleason grading is currently the predominant method for prediction, with only few biomarkers available. More biomarkers, especially as they relate to cancer progression are desirable. METHODS The abundance of several important proteins in prostate tissue was compared between wild-type mouse dorsal prostate and well-differentiated transgenic adenocarcinoma mouse prostate (TRAMP) mouse dorsal prostates, and between wild-type mouse dorsal prostate and poorly-differentiated TRAMP mouse tumor tissue. 2DIGE method in conjunction with MALDI-ToF and Western blots was used to determine differential expression. RESULTS In TRAMP dorsal prostates with well-differentiated adenocarcinoma, there were few significant changes in the protein abundances compared to wild-type dorsal prostates, with the exception of increases in proliferating cell nuclear antigen (PCNA) and beta tubulin, two proteins implicated in cell proliferation, and a more than 2-fold increase in Hsp60, a protein involved in the suppression of apoptosis. In the poorly-differentiated tumors, the changes in protein abundance were substantial. While some of those changes could be related to the disappearance of stromal tissue or the appearance of epithelial tissue, other changes in protein abundance were more significant to the cancer development itself. Most notable was the overall decrease in calcium homeostasis proteins with a 10-fold decrease in calreticulin and Hsp70 and a 40-fold decrease in creatine kinase bb in the cancerous tissue. CONCLUSIONS Proteomics of TRAMP mice provide an excellent method to observe changes in protein abundance, revealing changes in pathways during cancer progression. © 2005 Wiley-Liss, Inc. [source] Active Participation Instead of Passive Behaviour Opens Up New Vistas in Education of Veterinary Anatomy and HistologyANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2009J. Plendl Summary Teaching morphology, a fundamental part of medicine curricula is traditionally based on lectures and practical trainings. We introduced peer-assisted learning (PAL) and student expert teams to the courses to give the students the possibility to improve their free speech and self-confidence. We involved students in active preparation of online materials such as labelled e-slides and e-pics. We offered online digital microscopy (ZoomifyTM) and dissection (CyberPrep) allowing repeating the learned material and studying veterinary morphology outside the dissection theatre. Over 60% of first and third semester students profited from being a peer or being taught by a peer and 50% said the expert teams were an excellent method to learn the topographic anatomy. Almost all students applied ZoomifyTM and CyberPrep and 75% of them found the digital microscopy and dissection to be a helpful or very helpful learning tool. In face of reduced contact hours, these forms of education compensated in part the lost teaching time. We observed improvement of rhetoric and presentation skills and self-confidence. The approaches should therefore find their constant place in the veterinary medicine curricula. [source] Comparison of visual acuity measurements and Purkinje's vessel shadow perception for prediction of postoperative visual acuity in different ophthalmological diseasesACTA OPHTHALMOLOGICA, Issue 2 2007Stephan Schulze Abstract. Purpose:, Prediction of postoperative visual acuity (VA) is extremely important to the patient and highly relevant to the surgeon. However, objective evaluation of the macula is frequently impossible in cases such as mature cataract, cataract in high myopia or vitreous haemorrhage. This study compares different preoperative examination techniques used to predict postoperative VA. Methods:, We retrospectively evaluated the charts of all patients who underwent any of the following procedures at our hospital in 2004: phacoemulsification for mature cataract or cataract in high myopia; vitrectomy for diabetic vitreous haemorrhage; macular pucker, and macular hole. The following methods were evaluated: preoperative distance and reading VA; laser interferential VA; Purkinje's vessel shadow perception, and postoperative distance VA. Results:, Complete documentation was available for 136 patients (29 mature cataracts, 25 immature cataracts in high myopia, 42 vitreous haemorrhages, 19 macular puckers, 21 macular holes). In cases of preoperative mature cataract, a positive Purkinje's vessel shadow perception predicted a postoperative VA , 20/50 (odds ratio 11.2). In cases of high myopia, interferential VA correlated best with visual outcome (p < 0.05). In macular surgery laser interferential VA predicted postoperative VA to be better and preoperative reading VA predicted it to be worse than it actually turned out after surgery. Laser interferential VA and last known VA prior to vitreous haemorrhage (mean of 20 months previously) correlated best with postoperative VA (p < 0.05) in cases of vitreous haemorrhage. Purkinje's vessel shadow perception , if positive , predicted a postoperative VA , 20/300 in these cases (odds ratio 15.0). Conclusions:, Postoperative VA after vitrectomy for macular pucker or macular hole and in cases of cataract in high myopia is best predicted by laser interferential VA. Postoperative VA after vitrectomy for diabetic vitreous haemorrhage is best predicted by prehaemorrhage VA or laser interferential VA, especially when prehaemorrhage VA is unknown. Positive Purkinje's vessel shadow perception is an excellent method of predicting postoperative VA , 20/300 in cases of vitreous haemorrhage and VA = 20/50 in mature cataract. [source] Rapid diagnosis of coccidioidomycosis by nested PCR assay of sputumCLINICAL MICROBIOLOGY AND INFECTION, Issue 4 2007R. De Aguiar Cordeiro Abstract Coccidioidomycosis is a deep infection caused by two dimorphic fungi, Coccidioides immitis and Coccidioides posadasii. Diagnosis of the disease requires culture of suspicious clinical samples on mycological media. However, as these species are virulent pathogens, handling of their cultures is a high-risk activity, and is limited to Biosafety Level 3 laboratories. This study describes the direct detection of C. posadasii DNA in an inappropriate sputum sample by PCR amplification of the highly specific Ag2/PRA antigen gene. The results obtained suggest that direct detection of the Ag2/PRA sequence in sputum is an excellent method for rapid and specific diagnosis of coccidioidomycosis. [source] Age-specific size of the normal adenoid pad on magnetic resonance imagingCLINICAL OTOLARYNGOLOGY, Issue 5 2000R.C. Vogler Conclusions regarding the significance and appearance of the adenoids incidentally noted on magnetic resonance (MR) scans of the brain largely rely on observations of previously published plain film data. In order to determine the age specific appearance of normal adenoid tissue as measured on sagittal T1-weighted midline MR images, we evaluated 189 patients without a history or clinical evidence of adenoid disease, who were sequentially referred for an MR scan of the brain. The thickness of the adenoid pad was measured to the nearest 1 mm along a line through the pharyngeal tubercle constructed perpendicular to the anterior clival surface. Patients were grouped according to age. Normal subjects demonstrated an age specific variation in the size of the pad with the maximal size being attained in early childhood and then steadily decreasing in later childhood and adulthood (P = 0.0001). The adenoids were largest in the 7,10 years age group (mean, 14.59 mm) and steadily declined to 4.83 mm by 60 years of age. Previous surgery had no effect on adenoid measurement (P = 0.582). Magnetic resonance scans provide an excellent method for assessing the adenoid pad. [source] | ||||||||||||||||