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At least 1,063 records · Page 59Linked to original sources
PubMed2006

Procalcitonin is not sufficiently reliable to be the sole marker of neonatal sepsis of nosocomial origin.

BACKGROUND: It has recently been suggested that serum procalcitonin (PCT) is of value in the diagnosis of neonatal sepsis, with varying results. The aim of this prospective multicenter study was to assess the usefulness of PCT as a marker of neonatal sepsis of nosocomial origin. METHODS: One hundred infants aged between 4 and 28 days of life admitted to the Neonatology Services of 13 acute-care teaching hospitals in Spain over 1-year with clinical suspicion of neonatal sepsis of nosocomial origin were included in the study. Serum PCT concentrations were determined by a specific immunoluminometric assay. The reliability of PCT for the diagnosis of nosocomial neonatal sepsis at the time of suspicion of infection and at 12-24 h and 36-48 h after the onset of symptoms was calculated by receiver-operating characteristics (ROC) curves. The Youden's index (sensitivity + specificity - 1) was used for determination of optimal cutoff values of the diagnostic tests in the different postnatal periods. Sensitivity, specificity, and the likelihood ratio of a positive and negative result with the 95% confidence interval (CI) were calculated. RESULTS: The diagnosis of nosocomial sepsis was confirmed in 61 neonates. Serum PCT concentrations were significantly higher at initial suspicion and at 12-24 h and 36-48 h after the onset of symptoms in neonates with confirmed sepsis than in neonates with clinically suspected but not confirmed sepsis. Optimal PCT thresholds according to ROC curves were 0.59 ng/mL at the time of suspicion of sepsis (sensitivity 81.4%, specificity 80.6%); 1.34 ng/mL within 12-24 h of birth (sensitivity 73.7%, specificity 80.6%), and 0.69 ng/mL within 36-48 h of birth (sensitivity 86.5%, specificity 72.7%). CONCLUSION: Serum PCT concentrations showed a moderate diagnostic reliability for the detection of nosocomial neonatal sepsis from the time of suspicion of infection. PCT is not sufficiently reliable to be the sole marker of sepsis, but would be useful as part of a full sepsis evaluation.

Biomarkers↗
PubMedDate not supplied

[Screening for Down syndrome using triple marker testing in the second trimester of pregnancy].

The aim of this study was to check the validity of the biochemical screening of pregnancies with Down's syndrome during the second trimester of pregnancy, in order to reduce the incidence of invasive diagnostic procedures. We used the optimal balance between sensitivity and specificity to determine the "cut off" values to estimate the results of the biochemical screening. Between January 1995 and December 2000, 2000 pregnancies were checked by double (determining hCG and AFP serum levels) and triple test, (determining hCG, AFP and uE3 serum levels). Competitive radioimmunochemical procedures (2nd trimester Amerlax-M, Ortho Clinical Diagnostics, USA) were used. The risk of Down's syndrome was calculated by Prenata program (Ortho Clinical Diagnostics, USA). The "cut off" median MoM values in pregnancies with Down's syndrome were 0.73 (AFP); 2.02 (hCG) and 0.74 (nE3). The calculated risk was compared with possibility 1:300 to estimate the results of biochemical screening. Our results were checked in the cytogenetic laboratory where samples of amniotic fluid, that we also took, were sent. We observed lower AFP levels (0.96 +/- 0.09 MoM), uE3 levels (0.65 +/- 0.1 MoM) and higher levels of hCG (1.57 +/- 0.27 MoM) in pregnancies with Down's syndrome, in comparison with euploid pregnancies of the corresponding gestational age. With 1:200 risk, the sensitivity of triple test is 80%, with acceptable number of false-positive results. This cut-off value showed to be acceptable for separating positive from negative results. Invasive procedures should be performed in pregnancies with positive screening result, with the aim of getting the tissue sample of the fetus for further cytogenetic analysis.

Adult↗
PubMed1999

Evidence to support a change in follow-up policy for patients with breast cancer: time to first relapse and hazard rate analysis.

The ideal follow-up for patients with cancer should be sensitive to the likelihood of relapse, for prompt investigation and treatment if indicated, together with the support of patient confidence. The current British Association of Surgical Oncologists guidelines for patients with breast cancer suggest intensive follow-up, including 3-monthly clinic visits during the first 2 years. These recommendations place increasing demands on clinical resources. The combined outcome of screening, early detection, dedicated clinical services that emphasize rapid diagnosis and concomitant improved survival, have resulted in increasing absolute numbers of diagnosed breast cancer patients in follow-up clinics. This article examines the follow-up of breast cancer patients to determine if the convention should be adjusted to obtain more from current resources while maintaining equivalent patient care. The data on all patients with breast cancer attending one general oncology clinic were examined in order to determine the pattern of relapse. Analyses identified: (1) the time to relapse at any site and at specific sites; and (2) the prognostic significance of three factors for subsequent relapse, namely nodal status, menopausal status and T stage at diagnosis. In 416 consecutive patients, the annual rate of relapse of breast cancer was found to increase progressively over the first 4 years. Nodal disease was the most important single variable as a predictor of relapse. The annual hazard rate for relapse for node positive patients in the first year was 5%; this increased to 10% and 14% in years three and four respectively. In contrast, in those patients who were node negative at diagnosis (302/416; 73%), the hazard rate for relapse was 1% in year one, increasing to 5% in years three and four. Intensive early follow-up of breast cancer patients provides no clear clinical gain for the great majority of patients, since early relapse is rare in the first year. The use of clinical funds and staff resources might be optimized to focus clinical follow-up on those patients at risk of recurrence. We suggest that all patients should continue to be monitored and receive psychological care through access to their general practitioner, skilled breast care nurses and specialized counsellors. Any patient at risk, or developing symptoms of relapse, would have immediate clinical access to the oncologist for diagnostic investigations. This strategy would optimize psychological patient care and use the full backup of clinical resources during the prolonged period over which relapse becomes more probable.

Adult↗
PubMed2001

[Need and quality assurance: can the introduction of the new generation mobile systems change the reference standards?].

The new generation of radiological mobile systems, by lowering the installation and depreciation expenses, has led to start new low volume catheterization laboratories. These equipments allow to obtain good quality images, but they are not so reliable for extended performances, so that they are not suitable for interventional procedures. On the other hand, the extension of the indications to coronary angiography and angioplasty, with the related increase in the population needs, leads the resetting of the reference areas to start new catheterization laboratories. Anyhow lowering of expenses and of the extension of the reference areas does not change the need for maintaining high activity levels of centers and first operators in order to guarantee the quality of diagnostic and interventional procedures. The optimal levels of centers in national standards are 800 coronary angiographies and 400 coronary angioplasties per year: these numbers indicate the experience necessary to warrant the quality of procedures, with optimal results and low rate of complications, therefore they should not be changed. The spreading of laboratories due to the new low cost radiological equipments leads to an increase in inappropriate procedures and in the total expenses for the management of cardiac patients, without a proportional advantage in prognosis and quality of life. In order to ensure a quick diagnostic and therapeutic process to all the patients who need invasive procedures, instead of starting new centers, it is worthwhile to perfect the efficiency of links among small and main centers following shared pathways.

Angioplasty↗
PubMed2002

[Work-up of soft tissue masses].

Imaging plays a major role in the diagnosis and follow-up of soft tissue masses. Echography including color-coded and Doppler studies is performed as a first step procedure. MRI contributes essential topographic and semeiologic information but may have a poor sensitivity and specificity for the characterization of malignant lesions showing features atypical for benignity. Early recognition of malignancy enables appropriate diagnostic work-up, including biopsy, and optimal management.

Biopsy↗
PubMed2000

Interferon-gamma-primed monocytoid cell lines: optimizing their use for in vitro detection of bacterial pyrogens.

In order to reduce animal testing for quality control of pharmaceutical agents intended for parenteral use, the Limulus amebocyte lysate (LAL) assay is now being accepted in many cases as an alternative to measuring pyrogenic activity of samples in rabbits. However, since the LAL test is specific for cell wall components from Gram-negative bacteria and is sometimes difficult to perform in samples containing large amounts of protein, this alternative still leaves a considerable diagnostic gap. Here, we have optimized a previously established test based on assessing the formation of neopterin or nitrite in interferon-gamma-treated human (THP-1) or murine (J774A.1, RAW264.7) monocytoid cell lines, respectively, in response to bacterial pyrogens. Optimal results were obtained either with THP-1 cells in serum-containing media and using a high concentration of interferon-gamma (IFN-gamma) or with RAW264.7 cells in serum-free media and independent of the IFN-gamma dose. Results were significantly correlated with those obtained by another cell-culture-based assay in which formation of tumor necrosis factor-alpha by THP-1 1G3 cells was assessed. Also in RAW264.7 murine monocytoid cells, formation of nitrite and of tumor necrosis factor-alpha in response to a variety of samples was correlated. Samples shown to be pyrogenic in rabbits in a previous study were unambiguously detected with the test presented here. As expected, the LAL test was negative with cell-free supernatants from Staphylococcus aureus66 kDa). Taken together, these results indicate that the use of monocytoid cell lines and the detection of metabolites which are triggered in the course of immunostimulation could fill the gap left by the LAL test and help to further reduce animal testing for pyrogens.

Animal Testing Alternatives↗
PubMed2000

An update on the diagnosis and assessment of osteoporosis with densitometry. Committee of Scientific Advisors, International Osteoporosis Foundation.

In 1994 the WHO proposed guidelines for the diagnosis of osteoporosis based on measurement of bone mineral density. They have been widely used for epidemiological studies, clinical research and for treatment strategies. Despite the widespread acceptance of the diagnostic criteria, several problems remain with their use. Uncertainties concern the optimal site for assessment, thresholds for men and diagnostic inaccuracies at different sites. In addition, the development of many new technologies to assess the amount or quality of bone poses problems in placing these new tools within a diagnostic and assessment setting. This review considers the recent literature that has highlighted the strengths and weaknesses of diagnostic thresholds and their use in the assessment of fracture risk, and makes recommendations for actions to resolve these difficulties.

Absorptiometry, Photon↗
PubMed2003

Decision analysis of antibiotic and diagnostic strategies in ventilator-associated pneumonia.

The optimal strategy for ventilator-associated pneumonia remains controversial. To clarify the tradeoffs involved, we performed a decision analysis. Strategies evaluated included antibiotic therapy with and without diagnostic testing. Tests that were explored included endotracheal aspirates, bronchoscopy with protected brush or bronchoalveolar lavage, and nonbronchoscopic mini-bronchoalveolar lavage (mini-BAL). Outcomes included dollar cost, antibiotic use, survival, cost-effectiveness, antibiotic use per survivor, and the outcome perspective of financial cost-antibiotic use per survivor. Initial coverage with three antibiotics was better than expectant management or one or two antibiotic approaches, leading to both improved survival (54% vs. 66%) and decreased cost (US dollars 55447 vs. US dollars 41483 per survivor). Testing with mini-BAL did not improve survival but did decrease costs (US dollars 41483 vs. US dollars 39967) and antibiotic use (63 vs. 39 antibiotic days per survivor). From the perspective of minimizing cost, minimizing antibiotic use, and maximizing survival, the best strategy was three antibiotics with mini-BAL.

Anti-Bacterial Agents↗
PubMed1999

[Up-dated progress in diagnosis and treatment of echinococcosis].

Diagnostic proces and choice of optimal management of cystic echinococcosis have to be related to the natural history of the parasite. The early and the late stages of invasion require a careful differential diagnosis with non-parasitic diseases. These are also the stages that many not require surgery. Chemotherapy, PAIR and "wait and observe approach" are alternative ways of cystic echinococcosis management. Em-18 WB test has a good diagnostic value in alveolar echinococcosis. Management of alveolar echinococcosis is based on radical surgery, prolonged chemotherapy and long-term observation.

Animals↗
PubMed1989

Radioimmunoscintigraphy with 111In labelled monoclonal antibody fragments (F(ab')2 BW 431/31) against CEA: radiolabelling, antibody kinetics and distribution, findings in tumour and non-tumour patients.

Forty seven patients with suspected malignant disease (mainly colorectal cancer) were studied with 111In labelled F(ab')2 fragments of an anti-CEA monoclonal antibody (BW 431/31). The kinetic data revealed a long whole body retention of the label (62% after 4 days) and a rapid blood clearance (77% within 24 h, 89% within 48 h) leading to an early positive tumour contrast 24 h p.i. and optimal scintigrams 48 h p.i. Diagnostic results were promising in local recurrences of colorectal cancer (8/10 positive = 80%) though false positive findings in patients with inflammatory bowel disease occurred probably due to cross-reaction with a human granulocyte antigen. Liver metastases and tumours neighbouring liver and spleen were often missed (10/27 = 37%) because of high nonspecific uptake in these organs. Thus BW 431/31 proved to be a suitable compound for radioimmunodetection, however, further improvements to optimize tumour affinity and specificity of the antibody are mandatory.

Aged↗
PubMed2002

Application of the development stages of a cluster randomized trial to a framework for valuating complex health interventions.

INTRODUCTION: Trials of complex health interventions often pose difficult methodologic challenges. The objective of this paper is to assess the extent to which the various development steps of a cluster randomized trial to optimize antibiotic use in nursing homes are represented in a recently published framework for the design and evaluation of complex health interventions. In so doing, the utility of the framework for health services researchers is evaluated. METHODS: Using the five phases of the framework (theoretical, identification of components of the intervention, definition of trial and intervention design, methodological issues for main trial, promoting effective implementation), corresponding stages in the development of the cluster randomized trial using diagnostic and treatment algorithms to optimize the use of antibiotics in nursing homes are identified and described. RESULTS: Synthesis of evidence needed to construct the algorithms, survey and qualitative research used to define components of the algorithms, a pilot study to assess the feasibility of delivering the algorithms, methodological issues in the main trial including choice of design, allocation concealment, outcomes, sample size calculation, and analysis are adequately represented using the stages of the framework. CONCLUSIONS: The framework is a useful resource for researchers planning a randomized clinical trial of a complex intervention.

Aged↗
PubMed2001

Recent advances in genetics, diagnosis, localization, and treatment of pheochromocytoma.

Pheochromocytoma is a rare but important tumor of chromaffin cells that is frequently considered in the evaluation of hypertension, arrhythmias, or panic disorder and in the follow-up of patients with particular genetic diseases. This report provides an update about the genetics, neurochemical diagnosis, localization by imaging, and surgical management of pheochromocytoma. Specific mutations of the RET proto-oncogene cause familial predisposition to pheochromocytoma in multiple endocrine neoplasia type II, and mutations in the von Hippel-Lindau tumor suppressor gene cause familial disposition to pheochromocytoma in von Hippel-Lindau disease. Recent findings demonstrating extraordinarily high sensitivity of plasma levels of metanephrines for detecting pheochromocytoma have led to an algorithm for clinical diagnostic steps. Nuclear imaging approaches, such as(123) I-metaiodobenzylguanidine scintigraphy and 6-[(18) F]fluorodopamine positron emission tomography, enhance both diagnosis and localization of the tumor, as described in an algorithm for patients with positive biochemical test results. Since pheochromocytoma is often benign, surgical resection by laparoscopic adrenalectomy can be curative. Areas requiring further work include determining appropriate follow-up of patients with familial pheochromocytoma, elucidating the bases for phenotypic differences, improving both specificity and sensitivity of biochemical tests, optimizing cost-effectiveness of diagnostic imaging, and testing the risk for tumor recurrence after partial adrenalectomy.

Adrenal Gland Neoplasms↗
PubMed1994

DSM-IV field trials for oppositional defiant disorder and conduct disorder in children and adolescents.

OBJECTIVE: The purpose of the field trials for oppositional defiant disorder and conduct disorder was to select valid diagnostic thresholds for these disorders and to compare the psychometric properties of DSM-IV criteria for oppositional defiant disorder and conduct disorder with previous DSM diagnostic formulations. METHOD: Structured diagnostic interviews, standardized clinician's validation diagnoses, and multiple measures of impairment were obtained for 440 clinic-referred children and adolescents aged 4-17 years. RESULTS: A diagnostic threshold of four symptoms of oppositional defiant disorder optimized identification of impaired children, improved agreement somewhat with the clinician's validation diagnosis, and had somewhat better test-retest agreement than DSM-III-R. In the case of conduct disorder, the optimal time window for ascertainment of symptoms was clarified. A diagnostic threshold of three symptoms of conduct disorder maximized accurate identification of impaired children and agreement with the clinician's validation diagnosis and resulted in slightly better test-retest agreement than DSM-III-R. Compared with the DSM-III-R definition, the DSM-IV definition of oppositional defiant disorder was somewhat more prevalent, but the prevalence of conduct disorder was essentially unchanged. CONCLUSIONS: DSM-IV definitions of oppositional defiant disorder and conduct disorder are somewhat better than DSM-III-R definitions in terms of internal consistency and test-retest agreement, and the validity of the DSM-IV definition of oppositional defiant disorder is slightly better than that of DSM-III-R.

Adolescent↗
PubMed1985

DNA ploidy measurements in tissue sections.

Nuclear DNA ploidy measurements based on tissue sections, although technically tedious and time consuming, can provide useful diagnostic and prognostic information. Methods for minimizing distributional errors and optimizing interpretation of DNA histograms are presented, and the diagnostic and prognostic significance of DNA ploidy measurements in gynecologic cancer and its precursors is reviewed.

Cell Nucleus↗
PubMed1999

Diagnosis of urogenital Chlamydia trachomatis infection by use of DNA amplification.

Numerous studies on DNA amplification and diagnosis of C. trachomatis infections have been performed since the first PCR for detection of C. trachomatis in clinical samples was described in 1990, but optimal sample preparation procedures are still lacking. The major problem in evaluating the diagnostic performance of the DNA amplification methods is that there is no clinical or microbiological reference standard for C. trachomatis infection. The evaluated diagnostic performance will therefore always be a reflection of of the chosen comparator(s). Despite this, it seems that the DNA amplification methods are more sensitive than the cell culture techniques and the techniques based on immunology. Compared with the tests based on immunology the specificity is also improved, which makes the DNA amplification methods useful for sample types contaminated with organisms cross-reacting in the immunologically based methods, i.e. pharyngeal and rectal swab samples. However, the specificity and thereby the predictive value of a positive test is not optimal. Since the predictive value of a positive test is highly influenced by the prevalence in the tested population, evaluation of applied tests is constantly needed, especially since the prevalence may be expected to decrease with intensified test activity and due to changes in safe sex practices after the advent of AIDS. The improved sensitivity of the DNA amplification methods allows the use of sample material in which the content of Chlamydia organisms is lower than in conventional swab samples, i.e. urine, semen, and vaginal secretions can be used as sample material. these samples can be obtained by the individuals themselves, and since transport conditions seem less critical for the test performance, samples can also be taken in the privacy of the home and subsequently mailed by the individual directly to the diagnostic laboratory. Such strategy for testing has led to improved partner tracing and universal screening, compared with traditional swab examinations at physicians' offices. Tests with an optimal diagnostic performance have not yet been reached, and several sample categories have not been studied sufficiently. The societal implications of the use of self-collected samples and universal screening have not been studied in full, but a milestone for new strategies in detection and preventing urogenital C. trachomatis epidemics has been reached with the availability of DNA amplification techniques.

Chlamydia Infections↗
PubMed2003

Specific delayed-type hypersensitivity responses to ESAT-6 identify tuberculosis-infected cattle.

Human and bovine tuberculosis have long been detected by skin testing with purified protein derivative (PPD), a complex mix of partly denatured mycobacterial antigens with suboptimal specificity. In the present study, skin tests based on ESAT-6, a recombinantly produced antigen highly specific for tuberculosis infection, were investigated. Although ESAT-6 was strongly recognized in vitro and induced high levels of gamma interferon, initial investigations demonstrated that higher doses of ESAT-6 than of PPD were needed to induce substantial delayed-type hypersensitivity reactions. Also, the kinetics of the skin test response differed for the two reagents; PPD showed maximal response at 72 h, but the response to ESAT-6 often peaked later at 96 h. Tests based on an optimized strategy (400 micro g of ESAT-6 measured between 72 and 96 h), in cattle infected with Mycobacterium bovis (n = 22) and animals sensitized by exposure to environmental mycobacteria showed ESAT-6 to have a promising diagnostic potential (sensitivity, 82%; specificity, 100%; optimal cutoff, 3 mm), compared with PPD (sensitivity, 86%; specificity, 90%; optimal cutoff, 4 mm). Larger investigations are required to refine cutoff points for any new diagnostic test, but the present results indicate great potential for skin tests based on specific antigens for accurate in vivo diagnosis of tuberculosis.

Animals↗
PubMed1998

Trypanotolerance, an option for sustainable livestock production in areas at risk from trypanosomosis.

Trypanosomosis is one of the major constraints on animal production in areas of Africa which have the greatest potential for significant increases in domestic livestock populations and livestock productivity. While the eradication of trypanosomosis from the entire continent is an unrealistic goal, considerable effort has been invested in the control of this disease through the use of trypanocidal drugs, management of the vector and exploitation of the genetic resistance exhibited by indigenous breeds. There is little hope that a conventional, anti-infection vaccine will be produced in the near future. Drug resistance is developing faster than generally thought. The control of the tsetse fly has been attempted over many decades. The decreasing efficacy of available trypanocidal drugs and the difficulties of sustaining tsetse control increase the imperative need to enhance trypanotolerance through selective breeding, either within breeds or through cross-breeding. Trypanotolerance has been defined as the relative capacity of an animal to control the development of the parasites and to limit their pathological effects, the most prominent of which is anaemia. A major constraint on selection for trypanotolerance in cattle, for both within-breed and cross-breeding programmes, has been the absence of practical reliable markers of resistance or susceptibility. Distinct humoral immune response to trypanosome infection is the major feature of bovine trypanotolerance. The role that these responses play in the control of infection or disease is being addressed by ongoing research, but remains a matter of speculation at present. Results in recent years have shown that packed cell volume (PCV) in particular and parasitaemia, the two principal indicators of trypanotolerance, are strongly correlated to animal performance. However, although direct effects of trypanosome infections on PCV and growth are obvious, more sensitive diagnostic methods for reflecting parasite control are required so that individual animals can be categorised reliably for their parasite control capability. One key finding is the major contribution made by each of the indicators evaluated to the overall trypanotolerance variance. Preliminary genetic parameters for PCV provide evidence that trypanotolerance is not only a breed characteristic but is also a heritable trait within the N'Dama population; this brings new opportunities for improved productivity through selection for trypanotolerance. More reliable estimation of genetic parameters of the indicators may well show that these parameters must be handled simultaneously for optimal progress. This would require diagnostics for assessing parasite control capability that identify trypanosome species more accurately, especially in mixed infections. A major advantage of trypanotolerant livestock, particularly N'Dama cattle, is the resistance or adaptation of this breed to many of the important pathogenes which prevail in the sub-humid and humid tropics. Research on practical indicators of resistance to these conditions will be required to establish relevant integrated strategies based on disease-resistant livestock. Selective breeding will require the integration of the traits that farmers hold important for their production systems.

Africa↗
PubMed2004

Serological method using recombinant S2 protein to differentiate equine infectious anemia virus (EIAV)-infected and EIAV-vaccinated horses.

We recently reported a highly protective attenuated live virus vaccine for equine infectious anemia virus (EIAV) based on a proviral construct (EIAVUKDeltaS2) with a genetically engineered mutation in the viral S2 gene that eliminates expression of this accessory protein. While the EIAVUKDeltaS2 vaccine provides protection from detectable infection by experimental challenge with highly virulent virus, the potential for commercial application of this vaccine is complicated by the fact that horses inoculated with the EIAVUKDeltaS2 vaccine strain become seropositive in various reference diagnostic assays based on detection of antibodies to virion core or envelope proteins. To address this issue, we describe here the development and optimization of a new serologic EIAV diagnostic enzyme-linked immunosorbent assay (ELISA) to detect serum antibodies to the EIAV S2 protein that are produced in infected horses but not in horses inoculated with the EIAVUKDeltaS2 vaccine virus. The test S2 protein antigen was developed using the S2 gene sequence from the EIAVUK strain of virus and a series of modifications to facilitate production and purification of the diagnostic antigen, designated HS2G. Using this HS2G as antigen, we describe the development of an affinity ELISA that provides a sensitive and specific detection of S2-specific serum antibodies in experimentally and field-infected horses (22 of 24), without detectable reactivity with immune serum from uninfected (12 of 12) or vaccinated (29 of 29) horses. These data indicate that the S2-based diagnostic ELISA has the potential to accurately differentiate horses infected with EIAV from horses inoculated with an attenuated EIAV vaccine strain with a mutant S2 gene.

Animals↗