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At least 487 records · Page 27Linked to original sources

Digital scanned projection radiography: optimization of image characteristics.

Fast interactive programs for the investigation of the effects of different processing methods were developed in an attempt to optimize the diagnostic value of digital scanned projection radiography (SPR) data. Filters from two classes of functions with varied frequency characteristics were evaluated. Arbitrary combinations of filtered and unfiltered images were generated. Speed was achieved by implementing the filtering as a convolution operation with standard computed tomography hardware (20 sec/image). The criteria for the choice of the reconstruction parameters are discussed. The clinical results show that suppressing the low-frequency content of the image, as in smoothing, low-pass filtering, and subtracting the background from the original image, optimizes the diagnostic value of SPR images.

Filtration↗

Multiplex PCR: optimization and application in diagnostic virology.

PCR has revolutionized the field of infectious disease diagnosis. To overcome the inherent disadvantage of cost and to improve the diagnostic capacity of the test, multiplex PCR, a variant of the test in which more than one target sequence is amplified using more than one pair of primers, has been developed. Multiplex PCRs to detect viral, bacterial, and/or other infectious agents in one reaction tube have been described. Early studies highlighted the obstacles that can jeopardize the production of sensitive and specific multiplex assays, but more recent studies have provided systematic protocols and technical improvements for simple test design. The most useful of these are the empirical choice of oligonucleotide primers and the use of hot start-based PCR methodology. These advances along with others to enhance sensitivity and specificity and to facilitate automation have resulted in the appearance of numerous publications regarding the application of multiplex PCR in the diagnosis of infectious agents, especially those which target viral nucleic acids. This article reviews the principles, optimization, and application of multiplex PCR for the detection of viruses of clinical and epidemiological importance.

Humans↗

Taking advantage of sophisticated pacemaker diagnostics.

The ever-increasing complexity of pacing systems, combined with functions that vary from one manufacturer to another, can pose challenges during analysis of device function. Standard pacemaker diagnostics are measured data, electrogram telemetry, maker annotations and event counters, albeit with their current limitations. New diagnostic features discussed include time-based diagnostics, histograms of sensed amplitudes, pacing thresholds, or impedance trending. Mode-switching algorithms, combined with diagnostic features, facilitate the use of dual-chamber devices in patients with paroxysmal atrial tachyarrhythmias. The introduction of electrogram storage into pacemakers further improves diagnostic capabilities and allows a permanent validation and optimization of diagnostic and therapeutic algorithms. External diagnostic devices, which provide Holter recordings with continuous marker annotations and patient-triggered diagnostics, are additional features that will become increasingly important.

Arrhythmias, Cardiac↗

Optimal use of infertility diagnostic tests and treatments. The ESHRE Capri Workshop Group.

The general definition of infertility is a lesser capacity to conceive than the mean capacity of the general population and infertile couples can be characterized in two groups: those unable to conceive without therapy and those who are hypofertile, but conceive without therapy. The initial diagnostic tests for infertility should include a midluteal phase progesterone assay, a semen analysis and a test for tubal patency such as a hysterosalpingogram. Measuring progesterone is the best test for confirming ovulation. To predict ovulation, evaluating the luteinizing hormone (LH) surge is the best single assay while measurement of LH plus preovulatory oestrogen is the best prediction. Today primary investigation of the morphology of the uterus and tubes should be by hysterosalpingography. However, ultrasound, particularly with simple contrast media, is likely to gain in importance. Laparoscopy should be reserved as a further diagnostic procedure or in combination with endoscopic surgery. There are situations in which semen analysis is of utmost importance and of absolute predictive value, namely, in cases of azoospermia. In general semen analysis remains a substantial part of the fertility workup, but any consideration of its predictive value has to be cautious. Performing genetic tests before, during and after assisted reproductive techniques (ART) is an intrinsic part of good clinical practice. These tests allow one to reach a correct diagnosis, to give adequate genetic counselling to the couple and their families in cases such as (i) women with Turner syndrome; (ii) men with 47, XXY; (iii) men or women with structural chromosomal aberration; (iv) men with Yq11 deletion or (v) men with congenital bilateral absence of vas deferens. Patients should, of course, be made aware of the occurrence of de-novo mutations taking place in the testis and in the embryo. Treatment of some causes of infertility are of proven value. For example induction of ovulation. Others are more controversial. Among the many empirical treatments suggested for the treatment of the various form of subfertility, surgical treatment of varicocele in the male, treatment of pelvic endometriosis in the female and the efficacy of the ART strategies offered to the subfertile couple are considered. Many varicocele studies are of poor quality. A few are good, but small in size. They do not show an improvement in pregnancy rates. Therefore, at the moment, there is insufficient scientific evidence for recommending routinely surgical treatment in subfertile and/or oligozoospermic men with a varicocele. Randomized, double-blind controlled trials demonstrated the modest efficacy of endometriosis ablation in increasing the pregnancy rate in infertile women while drugs suppressing ovulation are of no benefit to infertile women with endometriosis. Although the largest body of evidence available suggests that IVF success declines in repeated ART cycles, an accurate estimate of the true success rate in the 'nth' cycle of IVF treatment is not possible. Similarly little is still known of the reasons for the overall low continuation rates with IVF treatment.

Endometriosis↗

Optimization of CH fluorescence diagnostics in flames: range of applicability and improvements with hydrogen addition.

This study quantifies the range of premixed flame conditions for which CH fluorescece diagnostics are applicable, and it shows that the CH fluorescence signal can be increased if some of the hydrocarbon fuel is replaced with hydrogen. The CH fluorescence signal is found to be adequate for fuel-air equivalence ratios (phi) as small as 0.85 for both methane-air and propane-air flames. The CH signal increases until a maximum at phi = 1.25 and phi = 1.35 for methane-air and propane-air flames, respectively, and then decreases for richer conditions. A strategy to increase the CH fluorescence signal and decrease interference from soot precursors is proposed by addition of the proper amount of hydrogen to the hydrocarbon fuel. Hydrogen addition reduces the background signal from soot precursors by as much as afactor of 10 and increases the CH fluorescence signal by as much as 80%. The normalized CH fluorescence measurements are compared with computations that utilize GRI-MECH 3.0 chemistry. Sources experimental uncertainties are discussed.

Journal Article↗

[Optimization of therapeutic and diagnostic processes in the system of obligatory medical insurance in an outpatient ENT department].

How to organize effective activity of an outpatient ENT department in the system of obligatory medical insurance (OMI) is considered. To achieve this purpose, an analysis of everyday activity of an outpatient department was made with estimation of reference morbidity, epidemiological data on the residents of the Central Moscow District. Measures for introduction of novel technologies in therapeutic outpatient ENT practice are proposed. They include introduction of new otorhinolaryngological services, intensification of the work of ENT specialists, stimulation of their interest in mastering allied specialties, stimulation of medical assistants interest in mastering new procedures, estimation of ENT services cost and minimizing the difference between the cost of the service and salaries of the medical personnel.

Ambulatory Care Facilities↗

[Methods of statistical analysis in differential diagnostics of the degree of brain glioma anaplasia during preoperative stage].

The authors proposed a possible preoperative diagnostics of the degree of supratentorial brain gliom anaplasia using statistical analysis methods. It relies on a complex examination of 934 patients with I-IV degree anaplasias, which had been treated in the Institute of Neurosurgery from 1990 to 2004. The use of statistical analysis methods for differential diagnostics of the degree of brain gliom anaplasia may optimize a diagnostic algorithm, increase reliability of obtained data and in some cases avoid carrying out irrational operative intrusions. Clinically important signs for the use of statistical analysis methods directed to preoperative diagnostics of brain gliom anaplasia have been defined

Adult↗

Evaluation of the OptiMAL test for rapid diagnosis of Plasmodium vivax and Plasmodium falciparum malaria.

The development of rapid and specific diagnostic tests to identify individuals infected with malaria is of paramount importance in efforts to control the severe public health impact of this disease. This study evaluated the ability of a newly developed rapid malaria diagnostic test, OptiMAL (Flow Inc., Portland, Oreg.), to detect Plasmodium vivax and Plasmodium falciparum malaria during an outbreak in Honduras. OptiMAL is a rapid (10-min) malaria detection test which utilizes a dipstick coated with monoclonal antibodies against the intracellular metabolic enzyme parasite lactate dehydrogenase (pLDH). Differentiation of malaria parasites is based on antigenic differences between the pLDH isoforms. Since pLDH is produced only by live Plasmodium parasites, this test has the ability to differentiate live from dead organisms. Results from the OptiMAL test were compared to those obtained by reading 100 fields of traditional Giemsa-stained thick-smear blood films. Whole-blood samples were obtained from 202 patients suspected of having malaria. A total of 96 samples (48%) were positive by blood films, while 91 (45%) were positive by the OptiMAL test. The blood films indicated that 82% (79 of 96) of the patients were positive for P. vivax and 18% (17 of 96) were infected with P. falciparum. The OptiMAL test showed that 81% (74 of 91) were positive for P. vivax and 19% (17 of 91) were positive for P. falciparum. These results demonstrated that the OptiMAL test had sensitivities of 94 and 88% and specificities of 100 and 99%, respectively, when compared to traditional blood films for the detection of P. vivax and P. falciparum malaria. Blood samples not identified by OptiMAL as malaria positive normally contained parasites at concentrations of less than 100/microl of blood. Samples found to contain P. falciparum were further tested by two other commercially available rapid malaria diagnostic tests, ParaSight-F (Becton Dickinson, Cockeysville, Md.) and ICT Malaria P.f. (ICT Diagnostics, Sydney, Australia), both of which detect only P. falciparum. Only 11 of the 17 (65%) P. falciparum-positive blood samples were identified by the ICT and ParaSight-F tests. Thus, OptiMAL correctly identified P. falciparum malaria parasites in patient blood samples more often than did the other two commercially available diagnostic tests and showed an excellent correlation with traditional blood films in the identification of both P. vivax malaria and P. falciparum malaria. We conclude that the OptiMAL test is an effective tool for the rapid diagnosis of malaria.

Humans↗

Comparison of adenosine and exercise stress test for quantitative perfusion imaging in patients on beta-blocker therapy.

UNLABELLED: Beta-blocker therapy is used to decrease myocardial ischemia during exercise but may cause suboptimal diagnostic performance in exercise stress testing. The aim of the present study was to compare results of quantitative technetium-99-sestamibi single photon emission tomography (SPECT), following exercise stress test or pharmacological stress test with adenosine. We chose adenosine as comparison, since betablockers may not interfere with adenosine induced vasodilatation and therefore possibly may not interfere with its diagnostic performance. Sixteen patients with angiographically documented coronary disease (5 single-vessel, 6 two-vessel and 5 three-vessel disease), who were chronically treated with beta-blockers, performed SPECT imaging at rest, following bicycle exercise and following adenosine infusion in random order. The SPECT data were analyzed visually and quantitatively, using dedicated computer software (CEqual). According to both visual and quantitative SPECT analysis, adenosine was superior to show reversibility. Higher reversibility extent (50 +/- 15 vs. 26 +/- 12 pixels, p < 0.01) and more intense reversibility severity (110 +/- 29 vs. 49 +/- 23 sum of SDs, p < 0.05) were observed during adenosine than exercise. CONCLUSIONS: Less myocardial perfusion abnormalities during exercise than during adenosine stress in patients treated with beta-blockers may indicate less ischemia but also an impaired diagnostic performance. Thus adenosine stress test should be preferred to optimize the diagnostic sensitivity in patients during beta-blocker treatment.

Adenosine↗

Evaluation of OptiMAL Assay test to detect imported malaria in Italy.

This study evaluated a newly developed rapid malaria diagnostic test, OptiMAL Assay, to detect "Plasmodium falciparum malaria" and "non Plasmodium falciparum malaria" in blood samples from 139 individuals with a presumptive clinical diagnosis of imported malaria in Italy. OptiMAL Assay utilizes a dipstick coated with monoclonal antibodies against the intracellular metabolic enzyme, plasmodium Lactate Dehydrogenase (pLDH) present in and released from parasite-infected erythrocytes. Blood samples from 56 cases out of 139 were found "Plasmodium falciparum malaria" positive by microscopy; with these samples OptiMAL Assay and the ParaSight-F test, which is a kit detecting the P. falciparum histidin-rich protein 2 (HRP-2), showed an overall sensitivity of 83% and 94%, respectively, in comparison with microscopy. Parasitemia levels tested in the 56 P. falciparum positive blood samples by microscopy ranged from <0.004% to 20%. A correlation between sensitivity and parasitemia was evident and OptiMAL Assay and ParaSight-F test were more sensitive (96-100%; 100%) with samples with 0.1%-20% levels of parasitemia, while proved less sensitive (0-44%; 50-88%) with <0.004-0.01% levels of parasitemia.

False Positive Reactions↗

Neonatal screening for glutaric aciduria type I: strategies to proceed.

Acute encephalopathic crisis in glutaric aciduria type I results in an unfavourable disease course and poor outcome, dominated by dystonia, feeding problems, seizures and reduced life expectancy. A conditio sine qua non for the prevention of irreversible brain damage is timely diagnosis and start of therapy, i.e. before the onset of neurological disease. As there are no specific clinical signs or symptoms that allow a reliable detection of these patients before the manifestation of encephalopathic crises, neonatal screening programmes for glutaric aciduria type I have been established in some countries using analysis of glutarylcarnitine in dried blood spots by tandem mass spectrometry. This article summarizes recent strategies, pitfalls and shortcomings of mass screening for glutaric aciduria type I, focusing on the relevant risk of missing patients with a mild biochemical phenotype (i.e. low excretors). Furthermore, it evaluates a binary strategy--using glutarylcarnitine as primary variable and glutarylcarnitine/acylcarnitine ratios as secondary variable--to improve the diagnostic sensitivity and specificity of neonatal screening for glutaric aciduria type I. An optimization of diagnostic as well as therapeutic procedures must be achieved before screening for glutaric aciduria type I can be regarded as reliable and beneficial for all patients.

Amino Acid Metabolism, Inborn Errors↗

Evaluation of five computer programs in the diagnosis of second-degree AV block.

Five electrocardiogram (ECG) analyzing systems were tested with a microcomputer-based ECG signal generator to assess the accuracy of the systems in interpreting Wenckebach periodicity. Although normal sinus rhythm with normal PR intervals and sinus rhythms with first-degree atrioventricular (AV) block were diagnosed by all five systems, second-degree AV block with classic Wenckebach periodicity was routinely misdiagnosed by four of the five systems. No system recognized the atypical Wenckebach periods in a total of 200 trials, misinterpreting the phenomenon as atrial fibrillation, supraventricular rhythm, sinoatrial block, and other rhythm disturbances. In advanced AV block and a variety of ventricular arrhythmias, none of the five systems diagnosed second-degree AV block with Wenckebach periods. Marked unsatisfactory performance with regard to the diagnosis of Wenckebach periodicity indicates the urgent need for accelerated and comprehensive testing of ECG diagnostic equipment. The present generating device was seen as an effective troubleshooter in optimizing the diagnostic competency of computerized ECG systems.

Computer Simulation↗

Nanodiagnostics: a new frontier for clinical laboratory medicine.

BACKGROUND: The use of nanotechnologies for diagnostic applications shows great promise to meet the rigorous demands of the clinical laboratory for sensitivity and cost-effectiveness. New nanodiagnostic tools include quantum dots (QDs), gold nanoparticles, and cantilevers. QDs, which are the most promising nanostructures for diagnostic applications, are semiconductor nanocrystals characterized by high photostability, single-wavelength excitation, and size-tunable emission. QDs and magnetic nanoparticles can be used for barcoding of specific analytes. Gold and magnetic nanoparticles are key components of the bio-barcode assay, which has been proposed as a future alternative to the PCR. METHODS: We examined articles published over the past 10 years investigating the use of QDs, gold nanoparticles, cantilevers, and other nanotechnologies in promising diagnostic applications. RESULTS: Several nanodiagnostic assays have been developed, including a QD-based assay capable of detecting biotinylated prostate-specific antigen (PSA) at 0.38 ng/L, a bio-barcode assay capable of detecting 30 amol/L PSA in a 10-microL sample, and another able to detect 50 molecules of the Alzheimer marker amyloid beta-derived diffusible ligand in 10 microL of cerebrospinal fluid. CONCLUSIONS: Nanodiagnostics promise increased sensitivity, multiplexing capabilities, and reduced cost for many diagnostic applications as well as intracellular imaging. Further work is needed to fully optimize these diagnostic nanotechnologies for clinical laboratory setting and to address the potential health and environmental risks related to QDs.

Clinical Chemistry Tests↗

Criteria for the diagnosis of alcoholism.

Manifestations of alcoholism in general hospital patients were studied retrospectively by review of medical records to determine their frequency of occurrence. Pathophysiological indications of alcoholism were far more commonly recorded than were behavioral or psychological changes, although most diagnostic clues were notable by their absence from a majority of the records. Optimizing the diagnostic efficacy of those features of alcoholism that did occur may require application of the methods of statistical decision making. Absence from the charts of behavioral criteria and of indications of tolerance reflects deficiencies in both patient interviewing and medical record keeping. The traditional structure of the medical history may require modification to ensure recording of these more specific manifestations. In addition, continued efforts are needed to improve the undergraduate and the direct-care education of physicians.

Adult↗

mTHPC-mediated photodynamic diagnosis of malignant brain tumors.

Radical tumor resection is the basis for the prolonged survival of patients suffering from malignant brain tumors such as glioblastoma multiforme. We have carried out a phase-II study involving 22 patients with malignant brain tumors to assess the feasibility and the effectiveness of the combination of intraoperative photodynamic diagnosis and fluorescence-guided resection (FGR) mediated by the second-generation photosensitizer meta-tetrahydroxyphenylchlorin (mTHPC). In addition, intraoperative photodynamic therapy (PDT) was performed. Several commercially available fluorescence diagnostic systems were investigated for their applicability in clinical practice. We have adapted and optimized a diagnostic system that includes a surgical microscope, an excitation light source (filtered to 370-440 nm), a video camera detection system and a spectrometer for clear identification of the mTHPC fluorescence emission at 652 nm. Especially in regions of faint fluorescence, it turned out to be essential to maximize the spectral information by optimizing and matching the spectral properties of all components, such as excitation source, camera and color filters. To sum up, on the basis of 138 tissue samples derived from 22 tumor specimens, we have been able to achieve a sensitivity of 87.9% and a specificity of 95.7%. This study demonstrates that mTHPC-mediated intraoperative FGR followed by PDT is a highly promising concept in improving the radicality of tumor resection combined with a therapeutic approach.

Adult↗

Asthma: The yoga perspective. Part I. The somatopsychic imbalance in asthma: towards a holistic therapy.

While the standard physiological and even certain psychological characteristics of asthmatic patients are well known, the current diagnostic and therapeutic approach to asthma remains inadequate, as it neglects certain interrelated somatopsychic factors vital to an optimal diagnostic-therapeutic programme. These include the role of skeletal muscle tension and posture, the role of the 'voluntary' respiratory musculature, especially the diaphragm, as well as anxiety, emotional suppression and excessive self-consciousness, all of which may be precipitants rather than the outcome of the onset of asthma. On the basis of these neglected factors and others, implications for an optimally effective therapy are discussed. The physical medicine or physiotherapeutic, as well as other recent therapeutic approaches, are reviewed and evaluated. It is concluded that all of these therapies are too "specific," and that a more holistic approach is necessary (which is provided in 'Asthma: The Yoga Perspective,' Part II-"Yoga Therapy in the Treatment of Asthma").

Asthma↗

Rapid development of polyclonal antisera against infectious salmon anaemia virus and its optimization and application as a diagnostic tool.

Infectious salmon anaemia is an important disease of Atlantic salmon. One of the current methods of diagnosis is the indirect fluorescent antibody test (IFAT), using a monoclonal antibody specific to the haemagglutinin of the virus. The conformationally dependent nature of this antibody could be a drawback in its usefulness in other tests. This study describes the development and optimization of a polyclonal antiserum against infectious salmon anaemia virus, including a method of separating virus from cell culture components within culture supernatant. The antiserum was subsequently optimized for use in a variety of immunological diagnostic tests, including IFAT and an alkaline phosphatase-based immunoassay, and Western blot.

Alkaline Phosphatase↗