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Laboratory Diagnosis (laboratory + diagnosis)
Selected AbstractsLaboratory diagnosis of variant Creutzfeldt,Jakob diseaseHISTOPATHOLOGY, Issue 1 2000J W Ironside The neuropathological and biochemical features of 33 cases of variant Creutzfeldt,Jakob disease (vCJD) diagnosed up to the end of 1998 are analysed in relation to the 646 cases of suspected CJD referred to the CJD Surveillance Unit laboratory from 1990 to 1998. Morphological studies of the central nervous system, lymphoid tissues and other organs were accompanied by immunocytochemistry; Western blot analysis of PrPRES was performed on frozen brain tissue. The findings were analysed in relation to clinical and genetic data. The pathology of vCJD showed morphological and immunocytochemical characteristics distinct from other cases of CJD. PrP accumulation was widespread in lymphoid tissues in vCJD, but was not identified in other non-neural tissues. PrPRES accumulation in vCJD brain tissue showed a uniform glycotype pattern distinct from sporadic CJD. All analysed cases of vCJD were methionine homozygotes at codon 129 of the PrP gene. No evidence currently exists to suggest that cases of CJD diagnosed in individuals who are MV or VV at codon 129 of the PrP gene represent ,human bovine spongiform encaphalopathy (BSE)'. Continued surveillance is required to further investigate this possibility, with the need to investigate autopsy tissues from suspected cases by histological and biochemical techniques. [source] Laboratory diagnosis of Mycoplasma pneumoniae infectionCLINICAL MICROBIOLOGY AND INFECTION, Issue 4 2003F. Daxboeck Diagnosis of Mycoplasma pneumoniae infection is challenging due to the fastidious nature of the pathogen, the considerable seroprevalence, and the possibility of transient asymptomatic carriage. During recent years, various new techniques have been adapted for the diagnosis of M. pneumoniae infection, notably in the field of molecular biology. Standard polymerase chain reaction (PCR) is currently the method of choice for direct pathogen detection, but several PCR-related methods provide enhanced sensitivity or more convenient handling procedures, and have been successfully applied for research purposes. Among these techniques are real-time PCR, nested PCR, reverse transcriptase PCR (RT-PCR) and multiplex PCR. Generally, amplification-based methods have replaced hybridization assays and direct antigen detection. Serology, which is the basic strategy for mycoplasma diagnosis in routine clinical practice, has been improved by the widespread availability of sensitive assays for separate detection of different antibody classes. For the diagnosis of mycoplasma pneumonia, serology and direct pathogen detection should be combined. Extrapulmonary diseases may be diagnosed by direct pathogen detection alone, but the value of this diagnostic approach is limited by the probably immunologically mediated pathogenesis of some manifestations. This review summarizes the current state of Mycoplasma pneumoniae diagnosis, with special reference to molecular techniques. The value of different methods for routine diagnosis and research purposes is discussed. [source] Evaluation of extracts of Jatropha curcas and Moringa oleifera in culture media for selective inhibition of saprophytic fungal contaminantsJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 3 2009Grace Mebi Ayanbimpe Abstract Most fungi occur in nature and utilize simple sources of carbohydrates and nitrogen for growth. Sabouraud's dextrose agar has been an ideal medium for primary isolation of fungi from clinical specimens, but for specimens from nonsterile sites or heavily contaminated ones, it has been necessary to include inhibitory substances such as antibiotics like chloramphenicol (antibacterial) and cycloheximide (antifungal). The problems we have in the our laboratory owing to frequent contamination of cultures and the delays in the procurement of cycloheximide have stimulated a search for alternatives in our local environment to enhance effective laboratory diagnoses of fungal infections. Purified extracts of the leaves and bark of Jatropha curcas and Moringa oleifera (common plants in our locality) were tested against clinical isolates of fungi at various concentrations to determine the minimum inhibitory concentration at which common fungal contaminants are inhibited, without affecting the growth of the pathogenic fungi sought for. At a concentration of 0.75,mg,ml,1 contaminants were totally inhibited by the leaf extracts. The bark extracts did not inhibit any fungus even at higher concentrations. From the results it was evident that the leaf extracts of both plants have potentials for use as inhibitory substances in culture media against contaminant fungi including Aspergillus spp., Penicillium spp., etc. J. curcas and M. oleifera are very common plants in our locality. They can be obtained at almost no cost and at any time needed. The benefits of these findings to mycology laboratories in a developing country are enormous. J. Clin. Lab. Anal. 23:161,164, 2009. © 2009 Wiley-Liss, Inc. [source] Mycoplasma pneumoniae -associated myelitis: a comprehensive reviewEUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2006S. Tsiodras Myelitis is one of the most severe central nervous system complications seen in association with Mycoplasma pneumoniae infections and both acute transverse myelitis (ATM) as well as acute disseminated encephalomyelitis (ADEM) have been observed. We reviewed all available literature on cases of Mycoplasma spp. associated ATM as well as ADEM with dominant spinal cord pathology and classified those cases according to the strength of evidence implicating M. pneumoniae as the cause. A wide range of data on diagnosis, epidemiology, immunopathogenesis, clinical picture, laboratory diagnosis, neuroimaging and treatment for this rare entity is presented. The use of highly sensitive and specific molecular diagnostic techniques may assist in clearly elucidating the role of M. pneumoniae in ATM/ADEM syndromes in the near future. Immunomodulating therapies may have a role in treating such cases. [source] Use of a new silica clotting time for diagnosing lupus anticoagulant in patients who meet the clinical criteria for antiphospholipid syndromeJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 1 2006Panagiotis Grypiotis Abstract The silica clotting time (SCT) is a phospholipid-dependent coagulation assay used for the laboratory diagnosis of lupus anticoagulant (LA) antibodies. The sensitivity and specificity of a new commercial SCT for identifying LA in patients who meet the clinical criteria for antiphospholipid syndrome (APS), and its association with thrombotic events were evaluated here. Forty-five patients who met the clinical criteria for APS according to the Sapporo International Consensus Statement were examined. Sixty-nine patients who did not meet the clinical criteria for APS, and 20 blood donors were used as controls. Plasma samples from the patients and controls were tested for LA using a new commercial SCT with low and high synthetic phospholipid concentrations. The results were compared with those obtained by diluted Russell's viper venom time (dRVVT) and activated partial thromboplastin time (APTT). SCT's sensitivity for identifying LA in patients who met the clinical criteria of APS was higher compared to APTT and dRVVT (53.3% vs. 31.1% and 31.1%), and the specificities of these assays were 96.6%, 100%, and 98.9%, respectively. When dRVVT was combined with SCT, and dRVVT was combined with APTT their sensitivities were 57.7% and 48.8%, and their specificities were 96.6% and 98.9%, respectively. A stepwise logistic regression analysis indicated that the combination of dRVVT with SCT was associated with total thrombotic events (odds ratio (OR)=11.5, 95% confidence interval (CI)=1.25,106.3, P=0.031) as well as with venous thrombosis (OR=4.09, 95% CI=1.16,14.43, P=0.028). According to our results, SCT is the most sensitive assay for identifying LA in patients who meet the clinical criteria for APS. Moreover, the highest sensitivity was reached with a combination of SCT and dRVVT. The method's association with total thrombotic events and venous thrombosis was in fact significant. J. Clin. Lab. Anal. 20:15,18, 2006. © 2006 Wiley-Liss, Inc. [source] Increased detection of HBV DNA in HBsAg-positive and HBsAg-negative South African HIV/AIDS patients enrolling for highly active antiretroviral therapy at a Tertiary HospitalJOURNAL OF MEDICAL VIROLOGY, Issue 3 2009Azwidowi Lukhwareni Abstract This retrospective study investigated the prevalence of hepatitis B virus (HBV) in 192 stored sera from human immunodeficiency virus (HIV) positive South African patients initiating antiretroviral therapy (ART), and explored the implications of HBV,HIV co-infection on laboratory diagnosis of HBV. HBV serology (HBsAg, anti-HBs and anti-HBc) and nested HBV PCR assays targeting the HBV polymerase gene were performed, with HBV DNA positive samples being quantified with Cobas Taqman HBV test 48 assay (Roche Diagnostics). The study found that 63% (121/192) of patients had past or present HBV infection, and 40.6% (78/192) had detectable HBV DNA. Also, 22.9% (44/192) of patients were HBsAg positive and HBV DNA positive, while 23% (34/148) of HBsAG negatives had occult HBV infections. Of the 78 HBV DNA positive samples, 62.8% had viral loads ranging from 102 to ,108 IU/ml, and 37.2% had HBV viral loads <200 IU/ml. There was a statistically significant positive association between HBsAg-positivity and high viral loads, with 27% (12/44) of HBsAg positives having HBV viral loads between 104 and ,108 IU/ml, compared to only 5.9% (2/34) of HBsAg negatives (relative risk: 4.64; 95% confidence interval: 1.11, 19.35; chi-square P -value,=,0.015). The study shows that the majority of HIV/AIDS patients initiating ART have either acute or chronic HBV infections, and further confirms that HIV remains a risk factor for occult HBV infections in South African patients as previously shown. The findings strongly support HBV screening in all HIV-positive patients initiating ART in South Africa, considering that current ART regimens include drugs with anti-HBV activity (e.g., lamivudine). J. Med. Virol. 81:406,412, 2009. © 2009 Wiley-Liss, Inc. [source] HIV antigen,antibody combination enzyme immunoassay,the experience of a London Teaching HospitalJOURNAL OF MEDICAL VIROLOGY, Issue S1 2007Simon Goldenberg Abstract The introduction of the fourth generation HIV antigen,antibody combination enzyme immunoassay (HIV Ag,Ab EIA) has led to a reduction in the diagnostic "window period" when HIV antibody is negative during primary infection. This facilitates earlier laboratory diagnosis during sero-conversion. An HIV Ag,Ab EIA (AxSYM, Abbott Laboratories, Kent, UK) was introduced to a London Teaching Hospital since 2004 as the primary screening test. Confirmation was performed using another HIV Ag,Ab EIA (Vironostika, BioMérieux, Hampshire, UK) and an HIV Ab only assay (Bispot, Orgenics, Yavne, Israel). Retrospective analysis identified a total of 20 sero-converting patients who would have been missed if the standard antibody-only HIV tests had been used as the primary screening test. This accounted for approximately 3% of the new diagnoses made by the laboratory. The median time from onset of illness to sero-conversion was 18 days. Two patients had multiple samples analyzed between initial presentation and eventual sero-conversion. One had a prolonged sero-conversion illness lasting for over 137 days; the other sero-converted within 17 days. A plotting of the signal to cut-off ratio with time of the two HIV Ag,Ab EIAs showed a V-shaped curve and both tests were below cut-off at some time-points during sero-conversion. These two cases highlighted the difficulties in diagnosing HIV infection during sero-conversion. On the basis of these results, it is recommended that a fourth generation HIV Ag,Ab EIA could be considered for use as the standard of care, particularly in any population with a high rate of HIV infection. J. Med. Virol. 79:S23,S26, 2007. © 2007 Wiley-Liss, Inc. [source] Parvovirus B19 infection in pregnancy: Quantitative viral DNA analysis using a kinetic fluorescence detection system (TaqMan PCR)JOURNAL OF MEDICAL VIROLOGY, Issue 2 2002Antje Knöll M.D. Abstract Human parvovirus B19 infections are common in the general population, and infection during pregnancy may cause hydrops fetalis and fetal death. To initiate adequate treatment, accurate laboratory diagnosis is essential. The most sensitive tests are nested PCR systems, but these assays provide semiquantitative results at best. A parvovirus B19 DNA assay was developed based on the real time TaqMan PCR. This method was calibrated on the basis of serial plasmid dilutions and tested with an international parvovirus B19 standard. The assay was capable of quantifying parvovirus B19 DNA from one to about 5,×,107 genome equivalents per reaction (corresponding to 100 to 5,×,109 genome equivalents per ml serum). Samples from 51 pregnant women with suspected acute parvovirus B19 infection were tested, and positive PCR results were obtained in at least one of the materials investigated in 41 cases. The median viral DNA load in maternal blood samples was 1.3,×,104 copies/ml (range 7.2,×,102,2.6,×,107). Maternal virus DNA concentration was not associated with the presence of maternal symptoms and/or fetal complications. As the stage of infection was not known in the majority of cases, our data do not exclude an association between peak levels of parvovirus B19 DNA and the development of complications. Maternal sera and corresponding fetal material were available for concurrent testing from 15 DNA-positive cases: in most fetal samples, viral DNA concentrations were several orders of magnitude higher (up to 2.1,×,1012 copies/ml) compared to the corresponding maternal blood samples. J. Med. Virol. 67:259,266, 2002. © 2002 Wiley-Liss, Inc. [source] Guidelines for the laboratory diagnosis of trichomoniasis in East European countriesJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 10 2010M Domeika Abstract The laboratory diagnosis of sexually transmitted infections in many Eastern European countries remains suboptimal. The main objective of the present evidence-based guidelines is to provide comprehensive information regarding the laboratory diagnosis of infections caused by Trichomonas vaginalis in East European countries. In particular, the present guidelines recommend: (i) to encourage examination of the wet mounts of vaginal exudates, instead of stained smears, at all clinical settings; (ii) nucleic acid amplification tests (NAATs) or culture could be employed if no trichomonads are detected on microscopic examination of the wet preparation and there is a strong indication of infection and (iii) the use of NAATs is encouraged in screening, using non-invasive specimens, or high volume testing situations. In the absence of internationally recognized commercial NAAT systems, tests developed in-house should be validated using obtainable international standards and quality assured strictly. Individual East European countries may be required to make minor national adjustments to these guidelines as a result of lack of accessibility to some reagents or equipment, or laws in a specific country. [source] Guidelines for the laboratory diagnosis of Chlamydia trachomatis infections in East European countriesJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 12 2009M Domeika Abstract The present guidelines aim to provide comprehensive information regarding the laboratory diagnosis of infections caused by Chlamydia trachomatis in East European countries. These recommendations contain important information for laboratory staff working with sexually transmitted infections (STIs) and/or STI-related issues. Individual East European countries may be required to make minor national adjustments to these guidelines as a result of lack of accessibility to some reagents or equipment, or laws in a specific country. [source] Guidelines for the laboratory diagnosis of syphilis in East European countriesJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 6 2009E Sokolovskiy Abstract The present guidelines aim to provide comprehensive and precise information regarding the laboratory diagnosis of the sexually transmitted infection (STI) syphilis in East European countries. These recommendations contain important information for laboratory staff working with STIs and/or STI-related issues. Individual East European countries may be required to make minor national adjustments to these guidelines as a result of lack of accessibility to some reagents or equipment, or laws in a specific country. Conflicts of interest None declared. [source] Anti- ,2-glycoprotein I antibody testing in the laboratory diagnosis of antiphospholipid syndromeJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 6 2005V. PENGO No abstract is available for this article. [source] Candida dubliniensis: first identification in Sfax hospital, TunisiaMYCOSES, Issue 2 2009M. Khlif Summary Candida dubliniensis, a newly described fungal pathogen associated mainly to immunocompromised host's infection, is phenotypically closely related to C. albicans. In this study, we report for the first time, isolation and identification, in Tunisia, of 14 isolates of C. dubliniensis from 12 human immunodeficiency virus-negative patients hospitalised in the intensive care unit (ICU) at Habib Bourguiba Sfax Hospital. Our study was firstly based on the failure to grow at 45 °C. This presumptive identification was completed by other tests: chlamydospore production, culture on Candiselect4 (Bio-Rad) and the commercial test Bichro-Dubli fumouze®, which specifically identify C. dubliniensis. The confirmation of the discrimination between both species was performed by PCR, targeting the hyphal wall protein (HWP1) gene. The recovery of C. dublinensis by routine laboratory diagnosis is recommended for elucidating the epidemiology of this novel pathogen. [source] Epidemiology, treatment and outcome of candidemia: a five-year review at three Canadian hospitalsMYCOSES, Issue 5-6 2002Behandlung und ausgang von Candidämien: Eine Fünfjahresübersicht an drei kanadischen Hospitälern, Epidemiologie Candidämie; Epidemiologie; Kanada Summary. To determine treatment regimens and epidemiological patterns in the occurrence of candidemia, a review of cases occurring from 1992 to 1996 in three large Canadian hospitals, University of Alberta Hospital (UAH) and Royal Alexandra Hospital (RAH), Edmonton, and Foothills Medical Center (FMC), Calgary, was carried out. Cases were detected by reviewing microbiology laboratory records. There were 202 cases in all (UAH 104, FMC 70, RAH 28). For the five study years the candidemia rate was 4.5/10 000 discharges (UAH 7.6, FMC 4.9, and RAH 1.7; P < 0.05 for all interhospital comparisons). The rate remained stable between 1992 and 1995 but rose dramatically in 1996 to 7.6/10 000 (P < 0.01 compared to 1995) as a result of increases at UAH and RAH. Of the 208 species identified, Candida albicans accounted for 135 (65%). During hospitalization 93 (46%) patients died. Species did not influence outcome. Antifungal treatment with fluconazole alone was given to 14% of patients, and increased in frequency throughout the study. No antifungal therapy was given to 47 patients (23%). This group had a much higher mortality (68%) than those who received treatment (39% P < 0.01). Twenty of the untreated patients had already died by the time the blood culture had been reported as growing a yeast. Candidemia rates vary significantly between hospitals and increased in some but not all over the five study years. As many patients with candidemia will have died by the time laboratory diagnosis is made, presumptive antifungal therapy in high-risk patients may be necessary if outcome is to be improved. Zusammenfassung. Um epidemiologische Muster zu erkennen und Behandlungsmethoden zu optimieren, wurden die Candidämiefälle in der Zeit von 1992 bis 1996 in drei großen kanadischen Kliniken analysiert: University of Alberta Hospital (UAH) Royal Alexander Hospital (RAH), Edmonton und Foothills Medical Center (FMC), Calgary. Es wurden die archivierten mikrobiologischen Laborbefunde ausgewertet, insgesamt 202 Fälle (UAH 104, FMC 70, RAH 28). Im 5-Jahreszeitraum betrug die Candidämierate 4.5/10 000 Entlassungen (UAH 7.6, FMC 4.9, RAH 1.7, P < 0.05 für den Interklinikvergleich). Die Rate blieb zwischen 1992 und 1995 stabil, stieg aber im Jahr 1996 auf 7.6/10 000 (P < 0.01 im Vergleich zu 1995) infolge der Zunahme im UAH und RAH. Unter den 208 identifizierten Isolaten waren 135 Candida albicans (65%). Während der Hospitalisierung verstarben 93 Patienten (46%). Die Erregerart hatte keinen Einfluß auf den Krankheitsausgang. Fluconazol allein wurde 14% der Patienten verabreicht, die Verordnungshäufigkeit stieg während der Studie an. Keine antimykotische Therapie wurde 47 Patienten verordnet (23%). Diese Gruppe hatte eine wesentlich höhere Mortalität, nämlich 68%, im Vergleich zu der behandelten mit 39% (P < 0.01). 20 der nichtbehandelten Patienten waren schon zu dem Zeitpunkt verstorben, als der Befund ,Hefewachstum' aus der Blutkultur erhoben wurde. Die Candidämieraten unterschieden sich signifikant zwischen den Kliniken und stiegen in einigen, aber nicht allen im 5-Jahreszeitraum an. Da viele Patienten bereits während des Zeitraumes der Labordiagnostik verstarben, erscheint bei Hochrisikopatienten eine empirische Frühtherapie unabdingbar, wenn der Krankheitsausgang optimiert werden soll. [source] JC virus persistence following progressive multifocal leukoencephalopathy in multiple sclerosis patients treated with natalizumab,ANNALS OF NEUROLOGY, Issue 3 2010Caroline F. Ryschkewitsch MT JC virus (JCV) DNA in the cerebrospinal fluid (CSF) provides the laboratory confirmatory diagnosis of progressive multifocal leukoencephalopathy (PML) in patients whose clinical symptoms and magnetic resonance imaging findings are consistent with PML. The Laboratory of Molecular Medicine and Neuroscience (LMMN), National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), made the confirmatory laboratory diagnosis in 35 multiple sclerosis (MS) patients treated with natalizumab. Thirteen patients had 3 or more CSF samples taken from weeks to months following PML diagnosis. Seven of the 13 patients demonstrated persistence of JCV DNA in the CSF even though all patients experienced immune reconstitution inflammatory syndrome (IRIS), 11 patients had plasma exchange, and 2 had immunoabsorption. Specific anti-JCV antibody was measured in plasma/sera samples from 25 of the 35 patients. Most of the samples showed moderate to high or rising antibody levels from the time of PML diagnosis. However, plasma from 1 patient at or near the time of PML diagnosis had a titer considered seronegative and 2 other plasma samples from patients had titers considered at baseline for seropositivity. In several PML cases, viral persistence and neurological deficits have continued for several years, indicating that once initiated, JCV infection may not entirely clear, even with IRIS. Ann Neurol 2010;68:384,391 [source] A novel monoclonal antibody recognizing ,(1,3) glucans in intact cells of Candida and Cryptococcus,APMIS, Issue 10 2008N. KONDORI The cell walls of all medically important fungi contain a unique polyglucose compound, ,(1,3) glucan. In the present study, murine monoclonal antibodies were produced against linear and ,(1,6) branched ,(1,3) glucans, and their specificities were characterized for reactivity to other , glucans, fungal cell wall fragments, and fungal cells. Their reactivity was also compared with that of rabbit polyclonal antibodies raised against the same immunogens. Two mouse monoclonal antibodies (AG and BG) recognized immunoreactive epitopes in ,(1,3)(1,6) glucan by ELISA. In an inhibition assay of the anti-,(1,3)(1,6) activity of the monoclonals, the homologous antigen effectively inhibited the activity as expected, while ,(1,3) also inhibited the assay but to a much lesser extent. No inhibition was obtained by ,(1,3)(1,4) or ,(1,6), while a cell wall extract of Candida albicans (PPM) effectively inhibited both monoclonals. Cell wall fragments of C. albicans (CaCW) and Cryptococcus neoformans (CnCW) inhibited the anti-,(1,3)(1,6) activity of AG, while BG was much less or not inhibited at all. Immunofluorescence confirmed the unique antibody specificity of AG by its recognition of a ,(1,3)(1,6)-associated epitope on the cell surfaces of C. albicans,C. krusei, C. glabrata, and nonencapsulated C. neoformans. The epitope for the AG antibody is suggested to be present in the branching point of ,(1,3)(1,6), or in the randomly coiled ,(1,3) polyglucan due to the presence of branches. Thus, monoclonal antibodies to ,(1,3)(1,6) glucans may have potential as tools in the laboratory diagnosis of invasive yeast infections. [source] Comparison of microscopy, culture and in-house PCR and NASBA assays for diagnosis of Neisseria gonorrhoeae in Russia,APMIS, Issue 2 2008ELENA SHIPITSYNA This study aimed to assess the laboratory diagnosis of Neisseria gonorrhoeae in St. Petersburg, Russia. In total, 334 consecutive symptomatic patients were enrolled. Cervical and urethral specimens from women (n=286) and urethral specimens from men (n=48) were analyzed by microscopy, culture and two in-house NAATs, i.e. polymerase chain reaction (PCR) and nucleic acid sequence-based amplification (NASBA), developed in Russia. All N. gonorrhoeae- positive samples were confirmed using porA pseudogene and 16S rRNA gene sequencing. All methods displayed 100% specificity, i.e. positive predictive values of 100%. Compared to the PCR (most sensitive method in the present study), in women the sensitivity of both microscopy and culture was 31.8%, and that of NASBA was 90.9%. In men, microscopy, culture and NASBA displayed a sensitivity of 75%, 50% and 100%, respectively. The negative predictive values of microscopy, culture, and NASBA were 97.3%, 97.3%, and 99.6% in women, and 97.8%, 95.7%, and 100% in men, respectively. According to the PCR, the prevalences of N. gonorrhoeae were 4.5% (women) and 8.3% (men). In conclusion, both the investigated Russian NAATs displayed a high sensitivity and specificity. However, in general the diagnosis of gonorrhoea in Russia is suboptimal and crucially requires validation, improvements and quality assurance. [source] Use of Quantitative Broad-based Polymerase Chain Reaction for Detection and Identification of Common Bacterial Pathogens in Cerebrospinal FluidACADEMIC EMERGENCY MEDICINE, Issue 7 2010Richard Rothman MD ACADEMIC EMERGENCY MEDICINE 2010; 17:741,747 © 2010 by the Society for Academic Emergency Medicine Abstract Background:, Conventional laboratory diagnosis of bacterial meningitis based on microscopy followed by culture is time-consuming and has only moderate sensitivity. Objectives:, The objective was to define the limit of detection (LOD), analytic specificity, and performance characteristics of a broad-based quantitative multiprobe polymerase chain reaction (PCR) assay for rapid bacterial detection and simultaneous pathogen-specific identification in patients with suspected meningitis. Methods:, A PCR algorithm consisting of initial broad-based detection of Eubacteriales by a universal probe, followed by pathogen identification using either pathogen-specific probes or Gram-typing probes, was employed to detect pathogens. The 16S rRNA gene, which contains both conserved and variable regions, was chosen as the target. Pathogen-specific probes were designed for Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes. Gram-positive and -negative typing probes were designed based on conserved regions across all eubacteria. The LOD and time to detection were assessed by dilutional mocked-up samples. A total of 108 convenience cerebrospinal fluid (CSF) clinical samples obtained from the Johns Hopkins Hospital (JHH) microbiology laboratory were tested, and results were compared with hospital microbiologic culture reports. Results:, The LOD of the assay ranged from 101 to 102 colony-forming units (CFU)/mL. Pathogen-specific probes showed no cross-reactivity with other organisms. Time to detection was 3 hours. In clinical specimens, the universal probe correctly detected 16 of 22 culture-positive clinical specimens (sensitivity = 72.7%; 95% confidence interval [CI] = 49.8% to 89.3%), which were all correctly characterized by either pathogen-specific or Gram-typing probes. Adjusted sensitivity after removing probable microbiologic laboratory contaminants was 88.9% (95% CI = 65.3% to 98.6%). The universal probe was negative for 86 of 86 culture-negative specimens. Conclusions:, A broad-based multiprobe PCR assay demonstrated strong analytic performance characteristics. Findings from a pilot clinical study showed promise in translation to human subjects, supporting potential utility of the assay as an adjunct to traditional diagnostics for early identification of bacterial meningitis. [source] Effects of Presentation and Electrocardiogram on Time to Treatment of HyperkalemiaACADEMIC EMERGENCY MEDICINE, Issue 3 2008Kalev Freeman MD Abstract Objectives:, To assess the time to treatment for emergency department (ED) patients with critical hyperkalemia and to determine whether the timing of treatment was associated with clinical characteristics or electrocardiographic abnormalities. Methods:, The authors performed a retrospective chart review of ED patients with the laboratory diagnosis of hyperkalemia (potassium level > 6.0 mmol/L). Patients presenting in cardiac arrest or who were referred for hyperkalemia or dialysis were excluded. Patient charts were reviewed to find whether patients received specific treatment for hyperkalemia and, if so, what clinical attributes were associated with the time to initiation of treatment. Results:, Of 175 ED visits that occurred over a 1-year time period, 168 (96%) received specific treatment for hyperkalemia. The median time from triage to initiation of treatment was 117 minutes (interquartile range [IQR] = 59 to 196 minutes). The 7 cases in which hyperkalemia was not treated include 4 cases in which the patient was discharged home, with a missed diagnosis of hyperkalemia. Despite initiation of specific therapy for hyperkalemia in 168 cases, 2 patients died of cardiac arrhythmias. Among the patients who received treatment, 15% had a documented systolic blood pressure (sBP) < 90 mmHg, and 30% of treated patients were admitted to intensive care units. The median potassium value was 6.5 mmol/L (IQR = 6.3 to 7.1 mmol/L). The predominant complaints were dyspnea (20%) and weakness (19%). Thirty-six percent of patients were taking angiotensin-converting enzyme (ACE) inhibitors. Initial electrocardiograms (ECGs) were abnormal in 83% of patient visits, including 24% of ECGs with nonspecific ST abnormalities. Findings of peaked T-wave morphology (34%), first-degree atrioventricular block (17%), and interventricular conduction delay (12%) did not lead to early treatment. Vital sign abnormalities, including hypotension (sBP < 90 mmHg), were not associated with early treatment. The chief complaint of "unresponsive" was most likely to lead to early treatment; treatment delays occurred in patients not transported by ambulance, those with a chief complaint of syncope and those with a history of hypertension. Conclusions:, Recognition of patients with severe hyperkalemia is challenging, and the initiation of appropriate therapy for this disorder is frequently delayed. [source] Alternaria infections: laboratory diagnosis and relevant clinical featuresCLINICAL MICROBIOLOGY AND INFECTION, Issue 8 2008F. J. Pastor Abstract The genus Alternaria contains several species of melanized hyphomycetes that cause opportunistic human infections. The published literature contains 210 reported cases of human alternarioses between 1933 and the present day. The most frequent clinical manifestations are cutaneous and subcutaneous infections (74.3%), followed by oculomycosis (9.5%), invasive and non-invasive rhinosinusitis (8.1%) and onychomycosis (8.1%). Immunosuppression is frequently associated with cutaneous and subcutaneous infections and rhinosinusitis. The most important risk factors for cutaneous and subcutaneous infections are solid organ transplantation and Cushing's syndrome, and those for rhinosinusitis are bone marrow transplants. Having been exposed to soil and garbage is common in all cases of oculomycosis, with corticotherapy being a risk factor in 50% of these cases. Previous contact with soil and/or trauma to the nails is associated with most cases of onychomycosis. In general, alternariosis shows a good response to conventional antifungal drugs. On some occasions, steroid suppression or reduction is sufficient to resolve an infection. Itraconazole is the antifungal drug used most frequently to successfully treat onychomycosis and cutaneous and subcutaneous infections. Posaconazole and voriconazole are promising therapeutic options, with the latter being especially so for oculomycosis. [source] Autoimmune sensorineural hearing lossCLINICAL OTOLARYNGOLOGY, Issue 6 2003J. Mathews Autoimmune sensorineural hearing loss Autoimmune sensorineural hearing loss has been increasingly recognized as a clinical entity since its description by McCabe in 1979. Recognition and proper management of this condition is important, as it is one of the very few forms of sensorineural hearing loss that can be successfully treated by medical therapy. Recent studies have provided experimental evidence to suggest that immune processes can cause sensorineural hearing loss in animals and humans. However, antigenic targets within the inner ear are diverse and as a result conclusive evidence for specific autoimmune damage to the inner ear has been elusive. This review focuses on the recent progress in understanding of the aetio-pathogenesis of autoimmune hearing loss along with a description of the various clinical conditions in which they occur. Recent advances in the laboratory diagnosis and management of this interesting condition are also described. [source] | ||||||||||||||||||||||