Laboratory evaluation in the diagnosis of Lyme disease

PURPOSE: To provide a qualitative evaluation of the predictive value of the laboratory diagnosis of Lyme disease and to use the resultant data to formulate guidelines for clinical diagnosis. DATA SOURCES: A MEDLINE search of English-language articles or articles with English-language abstracts published from 1982 to 1996. DATA EXTRACTION: Sensitivity, specificity, and likelihood ratios were calculated, and a random-effects model was used to combine the proportions from the eligible studies. Prespecified criteria were used to determine which studies were eligible for analysis. DATA SYNTHESIS: Laboratory testing in general is not clinically useful if the pretest probability of Lyme disease is less than 0.20 or greater than 0.80. When the pretest probability is 0.20 to 0.80, sequential testing with enzyme-linked immunosorbent assay and Western blot is the most accurate method for ruling in or ruling out the possibility of Lyme disease. CONCLUSIONS: Laboratory testing is recommended only in patients whose pretest probability of Lyme disease is 0.20 to 0.80. If the pretest probability is less than 0.20, testing will result in more false-positive results than true-positive results; a negative test result in this situation effectively rules out the disease.     

Laboratory evaluation of tissue heart valves. A comparative assessment

Tissue of commercially prepared tissue heart valves were evaluated and compared with aluminium treated, fixed porcine valve tissue in vitro (tensile strength, scanning and transmission electron microscopy) and in vivo (calcification potential after subcutaneous implantation in the rat model). Valve leaflets (n = 40) were divided into four groups according to the method of treatment: Group I (fixed in 0.652% glutaraldehyde, control), Group II (fixed and treated with aluminium), Group III (fixed and treated with Toluidine blue) and Group IV (fixed and treated with watersoluble alkyl sulphate). Tensile strength was not influenced in Group II and III (p > 0.05). Group IV indicated a significant (p < 0.05) reduction in tensile strength. Scanning electron microscopy revealed damage and loss of surface endothelium in Group III and IV respectively. Transmission electron microscopy indicated damage to underlying matricial cells in Group III and IV. Calcification potential was significantly (p < 0.001) reduced in Group II to IV. We conclude that damage ultrastructure could contribute to the reduced tensile strength in Group IV and that reduced tensile strength might have an influence on the long-term durability of tissue heart valves. Antimineralization treatment of tissue heart valves does retard calcification but is yet unable to inhibit the process completely.     

Pertussis in Missouri: evaluation of nasopharyngeal culture, direct fluorescent antibody testing, and clinical case definitions in the diagnosis of pertussis

No diagnostic test for pertussis in routine use in the United States has both high sensitivity and high specificity. During a statewide increase in the incidence of pertussis in Missouri, we studied the clinical features of 153 patients with suspected pertussis in the Greater St. Louis area from whom a specimen for pertussis culture had been taken between 15 May and 19 September 1989. In this cross-sectional study, nasopharyngeal cultures were more likely to be positive for persons whose specimens were collected < 21 days after cough onset (adjusted rate ratio [RRa] and 95% confidence interval = 3.4; 1.5-8.0) and who were not receiving erythromycin/sulfamethoxazole prior to the culture [RRa = 5.8; 0.8-40.6], who had received fewer than three prior doses of pertussis vaccine [RRa = 1.8; 0.8-4.2], and whose specimen was in transit to the laboratory for < 4 days [RRa = 2.0; 0.8-5.5]. Among children < 5 years of age, spasmodic cough plus a lymphocytosis of > 10,000/mm3 was the acute symptom complex associated with the highest predictive value for a positive culture result (67%). Cough for > or = 14 days plus whoop was sensitive (81%) and specific (58%) for identifying children with culture-confirmed pertussis. Direct fluorescent antibody staining performed well as a screening test for pertussis but requires substantial commitment of personnel and resources. In the absence of a positive culture result, clinical case definitions should be used for decision making (e.g., initiation of antimicrobial therapy and routine case reporting).     

Mycobacterium ulcerans infection in a child from Angola: diagnosis by direct detection and culture

The purpose of this study is to listen to and interpret the experiences of independent older women in the community regarding their medication use. Their experiences were examined regarding medication information, sources of information, types of medication used, relationships with health care professionals and social support systems. The techniques used for data collection included guided qualitative semistructured interviews based on the principle of empowerment and notions of ideal and nonhierarchical communication. The emergent themes show that for these older women general practitioners were important in their medication experiences. Whilst trusted as carers in the acute care setting, registered nurses did not play a role in the medication experiences of these older women. Registered nurses are perceived as 'traditional carers' associated with medical and acute care settings. Although medication issues emerged that ideally required attention, the older women in this study generally perceived themselves to be capable of actively managing their health and medication use.     

Laboratory diagnosis of plague

Recently, progress of studies and technique developments on human and mammalian fertilization and early embryonic development in vitro are markedly. At the present time, however, some problems are remaining. In mammalian embryo culture, the major obstacles to progress in analysing epigenic regulation of development in other than the mouse and rabbit are the infamous blocks to development in vitro. At the present time, further studies are needed to dissolve the precise mechanism of these blocks. Factors which affect on embryo development are a great number and analysis of them is considered to be important for clinical application of the embryo culture system. Intracytoplasmic sperm injection(ICSI), at the present time, is employed widely for basic research and the treatment of male infertility. Using ICSI, recent studies are showing that mouse round spermatids can fertilize mature oocyte and the fertilized oocytes(embryos) develop into normal offspring after embryo transfer to foster mothers. Also, a recent report indicates development of normal mice from oocytes injected with secondary spermacyte nuclei. However, since some unsolved problems on spermatogenic cells such as round spermatids and secondary spermacytes remain, further studies are needed.     

Chemotherapy of advanced malignant lymphomas comparative evaluation of results with single agent and combination therapy

86 patients with advanced malignant lymphomas (stage III and IV) were treated either with Vinblastine given as a single agent (49 cases) or with combination chemotherapy MOPP or COP (37 cases). In both, Hodgkin's disease and non-Hodgkin's lymphomas, induction of remission, relaps-free survival and prognostic significance of initial clinical stage were evaluated, in relation to the therapeutic modality. In patients with Hodgkin's disease, combination chemotherapy was found to produce significantly more durable remissions, when compared with single agent therapy. However, difference in the response rate, which was found to be more effective following the combination chemotherapy, was not statistically significant. In patients with non-Hodgkin's lymphomas overall lower response was recorded, regardless of the therapy applied. In all patients, better response rate and longer lasting remissions correlated with initial stage III.     

Differential diagnosis of a vascular leukoencephalopathy within a CADASIL family: use of skin biopsy electron microscopy study and direct genotypic screening

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a condition caused by mutations of Notch3 gene on chromosome 19. Ultrastructural analysis of skin vessels discloses typical granular osmiophilic material (GOM) within the vascular smooth muscle basal lamina. We describe a CADASIL family in which two members suffering from a vascular leukoencephalopathy were shown to be CADASIL phenocopies: clinical and magnetic resonance imaging (MRI) findings in these two patients were similar to those observed in their affected relatives. However, the skin biopsy performed on one of them did not reveal any GOM in the vascular smooth muscle cells, and the Notch3 mutation present in this family was shown to be absent in these two individuals. We emphasize the role of a direct DNA test for gene mutation to make a differential diagnosis between CADASIL and other forms of vascular leukoencephalopathy.     

Laboratory diagnosis of allergic inflammation

Monitoring of allergic inflammation includes direct examination of biopsy specimens from mucosa and epithelium, and indirect study by sputum, bronchoalveolar and nasal lavage fluid and peripheral blood. Although, some of these detection assays are not applicable to clinical use, it is now possible to measure a number of inflammatory mediators released from cells participating in allergic disease. The release of performed histamine from peripheral blood basophils challenged with specific antigen remains a valuable in vitro correlate of immediate hypersensitivity reactions. However, other mediators such as LTC4 and IL-4 are also generated by basophils upon IgE dependent activation. Tryptase and PGD2 are released from mast cells upon activation. Eosinophils contain in their granules proteins that cause damage to the bronchial epithelium: MBP and ECP. It is possible to measure soluble markers from other cells (T cells, macrophages, platelets, endothelial cells) involved in allergic inflammation. Detection of mediators have produced data that have significantly added to our understanding of the mechanisms and allowed better pharmacological control of allergic inflammation.     

Renal transplant rejection. Role of color Doppler sonography and comparative evaluation of fluorometric and bioptic results

BACKGROUND: Aim of this work is to evaluate the morphological changes of the waveforms found in the parenchyma of the renal transplant rejection, establishing the prognostic significance. METHODS: 46 patients with symptomatic renal allograft underwent color Doppler ultrasound examination. The ultrasound characteristics were evaluated. The Resistive Index (RI), the morphological waveforms (divided into two groups: group A with regular waveforms, group B with irregular waveforms). Color Doppler pattern (R.I. and waveforms) were compared to histological and cytological specimens and to mean values of creatinine before and after therapy. RESULTS: In group A, the creatinine values varied between the start of rejection symptoms and after some days, giving a significant statistic result. Group B didn't show any important variations. The RI mean value was higher in group B. Significant results concerning correlation between Doppler parameters and histological specimens were not observed. CONCLUSIONS: The conclusion is drawn that in renal transplant rejection it is important to keep in mind also the variation of the waveforms to establish the clinical prognosis.     

Laboratory diagnosis of Lyme borreliosis

Three stages can be observed in Lyme borreliosis: the acute stage (with dermal and systemic disease), an intermediate stage (with neurological and cardiovascular complaints and myositis), and a chronic stage (with arthritis, low back pain, dermatological and neurological complaints). If no acute stage with erythema chronicum migrans is seen, laboratory tests must provide the diagnosis. In the so-called two-test protocol at least two different tests must be positive for a definite diagnosis. Because culture is difficult, serology (demonstration of specific IgM and IgG antibodies against spirochaetal antigens) is the preferred technique. Cross reactions, antigenic variations and differences in antigenic expression in American and European strains may cause false-negative and false-positive results with the current tests. Moreover, previous use of antibiotics can interfere with the production of specific antibodies, and the effect of therapy is not correlated with height and behaviour of antibody titres. Additional investigation with immunoblot techniques, demonstrating specific antibody patterns may be valuable. An interesting alternative, not yet fully developed, is detection of specific antigens in tissues.     

Laboratory diagnosis of bacterial vaginosis

Microbiological analysis of discharge from the genitals in passenger car conductors (5787 women and 1496 men aged 20 to 40) showed Gardnerella vaginalis to be the most frequent agent of urogenital infection. It was isolated in 26% cases, whereas Trichomonas were isolated in 2.5%, fungi in 1.5%, and gonococci in 0.27% cases. The diagnosis of gardnerellosis is reliable if the key cells are found. Monoinfection with G. vaginalis was diagnosed in 80% patients, the overwhelming majority (74%) of carriers of this bacterium had no inflammatory symptoms, and in only 26% the carrier state was associated with the presence of leukocytes and histiocytes, more often in the cervix. In men the carrier state was detected in 0.4% cases. The clinical picture of Gardnerella infection is similar to that of infection with Mobiluncus, which is little known. This infection occurred 10 times less frequently (2.5%) than gardnerellosis, but in 92% cases it was a component of mixed infection, most frequently in association with G. vaginalis. A little known fungus Leptothrix was found in the genital discharge of 4% examinees, mostly women, but sometimes in men as well; it is represented by 3 types of ramifying threads. The practitioners are to know these infections causing specific diseases, such as bacterial vaginosis, which are often responsible for serious complications in gynecology and obstetrics.     

Laboratory diagnosis of perinatal infections

The application of new technology to the diagnosis of infectious disease in neonates has markedly increased the potential for early clinical intervention. Although far from perfect, the new tests have increased knowledge of the nature of these diseases and give physicians the opportunity to apply current treatments more effectively as well as to develop new modes of therapy for this important class of diseases.     

Laboratory simulation of the direct rolling of steel

For the simulation of the casting process a special continuous-casting simulator with the possibility of varying the cooling condition during solidification was designed and built. The specimen geometry is suitable for the subsequent plane-strain hot-compression test with the hot-deformation simulator (Wumsi) for the simulation of hot rolling. By linking of both apparatuses a new design of a complete simulation of direct rolling or hot charging of steel has been developed for the range of initial thickness of plate-shaped specimens from 60 down to 20 mm.     

Laboratory evaluation of hypercoagulable states

The number of well-characterized hereditary and acquired hypercoagulable conditions is increasing, such that in many thrombophilic patients, the laboratory can now identify a hypercoagulable condition. This review describes the currently known hypercoagulable states that predispose patients to venous, and in some instances, arterial thrombosis. For each condition, the discussion includes the incidence, magnitude of the thrombotic risk in the general population in comparison with symptomatic families, synergistic interactions among the various hypercoagulable conditions, molecular pathogenesis, and interpretation of laboratory test results. In addition, recommendations for laboratory testing are summarized.     

Laboratory diagnosis of tuberculosis: past, present, and future

Resurgence of tuberculosis justifies extraordinary efforts to expedite TB diagnosis and susceptibility testing. This demands that laboratory support expand to a "second generation" of methods and procedures, including rapid availability of fluorochrome smears of concentrated specimens, faster techniques for detection (e.g., the BACTEC radiometric broth system and microcolony detection), quicker identification (e.g., high-pressure liquid chromatography, nonisotopic genetic probes), more rapid susceptibility testing methods (e.g., BACTEC), and reporting of these results as critical values. Guidelines have been established for turnaround time for results of smears, TB organism identification, and susceptibility testing to usual first-line drugs. A "third generation" of laboratory techniques soon will make testing not only more effective but also more efficient. These methods include direct testing of respiratory specimens through nonisotopic genetic probes as well as nucleic acid amplification techniques utilizing polymerase chain reaction (PCR) and other molecular procedures. These new procedures and protocols place heavy demands on laboratory test volume, technologist time and costs. For the healthcare system or clinical laboratory without the resources to deal with these new demands, referral of TB specimens represents a reasonable alternative, as long as transport is adequate to meet current CDC and other guidelines for turnaround time.     

Perceived susceptibility measures are not interchangeable: Absolute, direct comparative, and indirect comparative risk.

Objective: To provide an explanation of perceived susceptibility judgment that accounts for both inconsistencies among commonly used measures of perceived susceptibility (i.e., absolute risk, direct comparative risk, and indirect comparative risk) and their inconsistent relationships to disease risk factors. Inconsistencies are attributed to differential processing of general versus personal risk factors, coupled with the method of computation of the risk measures. Design and Measures: Study 1 characterized risk factors as general versus personal. In Studies 2 and 3, community-residing adult women (ns = 432 and 147, respectively) rated perceived susceptibility to osteoporosis, breast cancer, heart disease, and diabetes, rated risk factors, and reported personal medical history. Results: Correlations and regression analyses mainly supported our characterization of the source of inconsistencies among susceptibility measures and their relationships to risk factors. Conclusion: Perceived susceptibility measures are not interchangeable and can lead to opposite conclusions about correlates of perceived susceptibility. Researchers are cautioned against using indirect comparative measures, computed as difference scores, and are encouraged to use other methods to compel participants to consider the risk of others when making comparative judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)