Correlation of egg counts of Clonorchis sinensis by three methods of fecal examination

The Kato-Katz (KK) method is a well-known method of fecal examination for helminthiases. Its diagnostic sensitivity was found very high for clonorchiasis. The present study evaluated the correlation of Clonorchis sinensis egg counts by the KK method with those by direct smear and formalin-ether (FE) technique. The egg counts obtained by the KK method (Y) were correlated with the counts by direct smear (X) with the equation of Y = 659.4 + 0.266X (r2 = 0.738), but not with those by the FE method. The present study demonstrated that the KK method and direct smear were useful for both qualitative and quantitative diagnosis of clonorchiasis, especially in the field.     

Improved methods for the diagnosis of African trypanosomosis

The diagnosis of trypanosomosis in animals with low parasitaemia is hampered by low diagnostic sensitivity of traditional detection methods. An immunodiagnostic method based on a direct sandwich enzyme-linked immunosorbent assay (ELISA), using monoclonal antibodies, has been examined in a number of African laboratories for its suitability for monitoring tsetse control and eradication programmes. Generally, the direct sandwich ELISAs for the detection of trypanosomal antigens in serum samples have proved to be unsatisfactory with respect to diagnostic sensitivity when compared with traditional parasitological methods such as the dark ground/phase contrast buffy-coat technique. Consequently, antigen-detection systems exploiting various other direct, indirect and sandwich ELISA systems and sets of reagents are being developed to improve diagnosis. In addition, an existing indirect ELISA for the detection of antibodies has been improved and is being evaluated in the field in order to detect cattle that are or have been recently infected with trypanosomes. Developments and advantages of other diagnostic techniques, such as dip-stick assay and tests based on the polymerase chain reaction are also considered.     

Modification of the Microtiter Reading Mirror for Use in the Standardized Micro Complement Fixation Test

Modification of the Microtiter reading mirror used in the standardized diagnostic complement fixation method permits convenient estimation of the results in per cent hemolysis by direct visual comparison with the hemolytic standards.     

Use of Victoria blue in the detection of intrahepatocyte HBs Ag: comparison with other methods

The authors tested Victoria blue staining in intrahepatocytic HBs Ag detection and compared the results with those obtained by the following methods: direct immunofluorescence, orcein and peroxidase-antiperoxidase (PAP). Although PAP appears to be the best technique for diagnostic research, Victoria blue is a sound method for routine diagnosis in hepatology.     

Use of an in vitro allergy test for the differential diagnosis of human brucellosis and yersiniosis

The degree of the allergic reorganization in the body of brucellosis and yersiniosis patients was determined by the study of their blood and serum samples in the in vitro allergy test (the direct and indirect leukocytolysis test). The allergy test is highly specific and recommended as a differential diagnostic method in brucellosis and yersiniosis infections.     

Sensitivity of diagnostic tests for human soil-transmitted helminth infections: a meta-analysis in the absence of a true gold standard

Reliable, sensitive and practical diagnostic tests are an essential tool in disease control programmes for mapping, impact evaluation and surveillance. To provide a robust global assessment of the relative performance of available diagnostic tools for the detection of soil-transmitted helminths, we conducted a meta-analysis comparing the sensitivities and the quantitative performance of the most commonly used copro-microscopic diagnostic methods for soil-transmitted helminths, namely Kato-Katz, direct microscopy, formol-ether concentration, McMaster, FLOTAC and Mini-FLOTAC. In the absence of a perfect reference standard, we employed a Bayesian latent class analysis to estimate the true, unobserved sensitivity of compared diagnostic tests for each of the soil-transmitted helminth species Ascaris lumbricoides, Trichuris trichiura and the hookworms. To investigate the influence of varying transmission settings we subsequently stratified the analysis by intensity of infection. Overall, sensitivity estimates varied between the different methods, ranging from 42.8% for direct microscopy to 92.7% for FLOTAC. The widely used double slide Kato-Katz method had a sensitivity of 74–95% for the three soil-transmitted helminth species at high infection intensity, however sensitivity dropped to 53–80% in low intensity settings, being lowest for hookworm and A. lumbricoides. The highest sensitivity, overall and in both intensity groups, was observed for the FLOTAC method, whereas the sensitivity of the Mini-FLOTAC method was comparable with the Kato-Katz method. FLOTAC average egg count estimates were significantly lower compared with Kato-Katz, while the compared McMaster counts varied. In conclusion, we demonstrate that the Kato-Katz and Mini-FLOTAC methods had comparable sensitivities. We further show that test sensitivity of the Kato-Katz method is reduced in low transmission settings.     

Direct explanations for the development and use of a multi-layer perceptron network that classifies low-back-pain patients.

Using a new method published by the first author, this article shows how direct explanations can be provided to interpret the classification of any input case by a standard multilayer perceptron (MLP) network. The method is demonstrated for a real-world MLP that classifies low-back-pain patients into three diagnostic classes. The application of the method leads to the discovery of a number of mis-diagnosed training and test cases and to the development of a more optimal low-back-pain MLP network.     

Endometrial hyperplasia with berrylike squamous metaplasia and pilomatrixomalike shadow cells. Report of an intriguing cytohistologic case

BACKGROUND: The usefulness of endometrial cytology as a diagnostic method in asymptomatic women, especially in postmenopause, in the interpretation of composite pictures characterized by borderline features between atypical hyperplasia and well-differentiated adenocarcinoma, especially if associated metaplastic features are present, is somewhat controversial. CASE: An asymptomatic, 50-year-old, postmenopausal woman underwent a Pap smear and endometrial cytology for routine screening, disclosing three-dimensional, sometimes pseudopapillary groupings of hyperplastic endometrial glandular cells with focal atypia in direct continuity with large, squamoid cells of the keratinizing type and shadow cells. Histologic examination of endometrial tissue was advised, and two subsequent endometrial biopsies and hysteroscopic ablation were performed. The borderline character of the lesion (complex atypical hyperplasia vs. well-differentiated adenocarcinoma) with concomitant squamous metaplasia and pilomatrixomalike shadow cells prevented diagnostic agreement between several pathologists. CONCLUSION: Diagnostic cytology with direct endometrial sampling represents a valuable diagnostic screening tool for the differential diagnosis between normal and pathologic endometrium, a mucosal picture that deserves a subsequent (histologic) diagnostic procedure. In a few cases, as in the one presented above, even histologic examination, especially of so-called borderline lesions, reveals squamous or other types of metaplasia that can lead to interobserver discrepancies.     

A cytogenetic study of the human chorion for the purpose of the prenatal diagnosis of hereditary diseases

Cytogenetical investigation of 50 diagnostic chorionic villus samples from women with a high risk of giving birth to babies with chromosomal and genic pathology, and of 128 chorionic samples obtained from medical abortions, both on the 8-12th weeks of gestation was performed by means of original direct chromosomal analysis. Chromosomal anomalies were found in 6 cases of diagnostic chorion biopsies (12%) and in 4 cases (3%) of medical abortions. The former group included 5 embryos with autosomal trisomy (4--Ts21 and 1--Ts13) and one embryo with monosomy 18. The latter group contained 2 embryos with X-chromosome monosomy and 2 other with chromosomal mosaicism. A significant prevalence of the female sex was found in the diagnostic group (sex ratio 0.56), but not in the medical abortion one (sex ratio 1.0). Analysis of routine chromosomal preparations and those after in situ hybridization with X-chromosome alfoid-probe YAP 1-10 revealed polyploidy in average in 0.8-1% chorion cells. The feasible causes of sex ratio distortion in embryos of diagnostic group and factors responsible for the rate of polyploidy are discussed. High reliability of originally elaborated direct "shaking-blotting" method of chromosomal preparations from chorionic villus samples is stressed.     

通用PCR法在痰标本真菌检测中的临床应用价值分析

目的:探讨通用PCR法在痰标本真菌检测中的临床应用价值。方法:选择2015年9月至2017年9月本院收治的免疫力低下患者178例作为研究资料,各收集痰标本2份,其中一份用于PCR扩增,另一份经培养后若观察到真菌或可疑菌落,则提取后在此进行PCR扩增测序。比较3种方法对真菌的检出情况、真菌阳性率,与组织病理学结果进行比较,分析3种方法的诊断效能。结果:178份痰标本经平板培养可观察到107份真菌生长,其余71份未见真菌生长。挑取真菌及可疑菌落行PCR结果显示阳性、阴性分别115、63份。对痰标本直接PCR结果显示,阳性、阴性分别124、54份。PCR扩增产物测序结果显示大多是白色念珠菌感染,仅3份是曲霉菌感染。内对照扩增验证结果显示有1份阴性标本存在扩增抑制现象。3种方法的真菌阳性率:直接PCR法痰培养后PCR法痰培养,但组间无显著差异(P0.05)。3种方法诊断效能总体趋势:直接PCR法痰培养后PCR法痰培养,其中直接PCR法与痰培养后PCR法的特异度、准确度均显著高于痰培养法(P0.05),直接PCR法的敏感度显著高于痰培养法(P0.05)。结论:通用PCR法在痰标本真菌检测中的临床应用价值较高,直接PCR具有操作简单、快速等优势。     

Toxoplasmosis II. Studies of Animal Sera Using Complement-Fixation Tests

Serological studies were performed in guinea pigs, a sheep, calf, goat and two pigs experimentally infected with toxoplasmosis. The direct complement-fixation method was effective in detecting antibodies in guinea-pig, goat and sheep sera. The modified complement-fixation technique supplementing complement with normal bovine serum fraction, was required when testing bovine serum. With swine sera best reactions occurred in the indirect complement-fixation test and definite but low grade reactions were produced in the direct test after pro-complementary activity was removed by pH treatment of the sera. Allergic skin reactions were produced in the experimental animals but improvement in the antigen is necessary before the test could be used generally in the field as a diagnostic method for animal toxoplasmosis.     

Traditional and innovative diagnostic tools: when and why they should be applied

The development of new technological methods surely improves the quality of the Diagnostic Services in Parasitology offered to the National Sanitary Service, however, cost and simplicity have not to be neglected, even when the prime consideration is efficiency. Moreover, the mere fact that something can be done by one of these new approaches does not mean that it should be done that way or that it is most cost-effective to do it that way. A review of diagnostic tools in Parasitology is proposed, to evaluate when and why each of them should be applied. Traditional procedures for the diagnosis of parasitosis are only based on the "direct" recovery and recognition of the parasite, with the microscope as main tool and few other instruments as co-operator. The innovative procedures, recently adjusted on the basis of new scientific knowledge and made possible by the development of the laboratory instrument weapons, can evidence the parasites both directly and indirectly. If it is obvious that the direct identification of a pathogen is more reliable than that indirect, is not so evident what is the most useful direct method, and when it would be better to use indirect diagnostic tools. Advantages and disadvantages of each procedure, cost as well as the purpose of the test (diagnosis, post-treatment, research), and the general condition in which the test have to been applied must be taken into account when we are choosing. In general, we can say that the rationale for their use can be summarised as follows: 1) The macroscopic/microscopic analysis of samples is always recommended (with the exception of samples coming from tissues that need surgery). This "old" procedure allows the identification in 20 minutes of all the parasites present in mixed infections, and the evaluation of the parasite load. It is a cost-effective method which relies ultimately on the skill of the observer to detect and identify parasite stages; 2) Parasite antigen detection is an innovative and expensive immunological diagnostic, which can suffer of sensitivity and specificity. It could be useful to directly diagnose "occult" infections; 3) Parasite DNA/RNA direct detection is an innovative, sensitive and specific procedure, which can also identify sibling species. It is expensive, therefore its use is restricted to reference laboratories; 4) Host antibody detection is an innovative indirect tool to evaluate the presence of a parasite by means the evaluation of the host response to infection. It can suffer of sensitivity and specificity, and the interpretation of the test results may be difficult. It could be applied as first step to evaluate the presence of tissue parasites, whose direct diagnosis would require surgery. Some tests can be performed in well-equipped laboratories; other tests are available through research laboratories. The specimens, appropriately collected and preserved, have always to be processed in security for potential risk of infection hazard, and submitted to tests appropriate to the laboratory's goals, where, therefore, field and research diagnostic tools shouldn't be applied. The test selected for routine use has to be chosen taking into account value and limitations of each method. Reduction in excessive and often unnecessary testing is mandatory, and therefore it is critical for the clinical Parasitology to perform relevant testing while maintaining appropriate quality. To date, the microscopic analysis of samples is the only direct method that allows all identifications in short times, at a reduced cost, independently from geographical origin and peculiar status of the patient. It has to be regarded as the first step in diagnostic procedures for all laboratories. Some molecular techniques have greater sensitivity than traditional methods, but at least at the present time, their costs may well preclude their routine use. It is difficult to know, exactly, where diagnostic Parasitology will be moving in the next few years, although many soothsayers feel very strongly that the area of molecular diagnostics will replace more traditional means. It is also possible that immunological or perhaps cytometric procedures will replace our more standard diagnostic approach; nevertheless they will continue to remain oddities on the outside of the general practice and be confined to a few reference laboratories. As far as semi-automated or automated instruments and robotics-based techniques, they are useful when large numbers of the same test are performed. Supposing that they will enter in our laboratory, that will happen in central facility rather than in each local facility. So, the great interest in using new technological methods to solve old problems probably will have to be seen in the right perspective.     

Direct detection of double-stranded DNA: Molecular methods and applications for DNA diagnostics

Methodologies to detect DNA sequences with high sensitivity and specificity have tremendous potential as molecular diagnostic agents. Most current methods exploit the ability of single-stranded DNA (ssDNA) to base pair with high specificity to a complementary molecule. However, recent advances in robust techniques for recognition of DNA in the major and minor groove have made possible the direct detection of double-stranded DNA (dsDNA), without the need for denaturation, renaturation, or hybridization. This review will describe the progress in adapting polyamides, triplex DNA, and engineered zinc finger DNA-binding proteins as dsDNA diagnostic systems. In particular, the sequence-enabled reassembly (SEER) method, involving the use of custom zinc finger proteins, offers the potential for direct detection of dsDNA in cells, with implications for cell-based diagnostics and therapeutics.     

Semi-parametric area under the curve regression method for diagnostic studies with ordinal data

The classification accuracy of new diagnostic tests is based on receiver operating characteristic (ROC) curves. The area under the ROC curve (AUC) is one of the well-accepted summary measures for describing the accuracy of diagnostic tests. The AUC summary measure can vary by patient and testing characteristics. Thus, the performance of the test may be different in certain subpopulation of patients and readers. For this purpose, we propose a direct semi-parametric regression model for the non-parametric AUC measure for ordinal data while accounting for discrete and continuous covariates. The proposed method can be used to estimate the AUC value under degenerate data where certain rating categories are not observed. We will discuss the non-standard asymptotic theory, since the estimating functions were based on cross-correlated random variables. Simulation studies based on different classification models showed that the proposed model worked reasonably well with small percent bias and percent mean-squared error. The proposed method was applied to the prostate cancer study to estimate the AUC for four readers, and the carotid vessel study with age, gender, history of previous stroke, and total number of risk factors as covariates, to estimate the accuracy of the diagnostic test in the presence of subject-level covariates.     

Painless Jaundice Caused by Clonorchis sinensis Infection: A Case Report

A man with only yellowing of the skin and eye sclera was diagnosed with clonorchiasis, which rarely manifested jaundice as the initial symptom. However, because of a lack of evidence for a diagnostic gold standard, the time until definitive diagnosis was more than a week. The diagnostic process relied on inquiring about the patient’s history, including the place of residence, dietary habits, and symptoms, as well as on serological findings, an imaging examination, and pathological findings. MRCP and CT results showed mild dilatation of intrahepatic ducts and increased periductal echogenicity. The eggs were ultimately found in stool by water sedimentation method after the negative report through direct smear. DNA sequencing of PCR production of the eggs demonstrated 98-100% homology with ITS2 of Clonorchis sinensis. After anti-parasite medical treatment, the patient’s symptoms were gradually relieved. Throughout the diagnostic procedure, besides routine examinations, the sedimentation method or concentration method could be used as a sensitive way for both light and heavy C. sinensis infection in the definite diagnosis.     

The true hanging columella: simplified diagnosis and treatment using a modified direct approach

An imbalance between the alar rim and the columella border can be a disturbing aesthetic deformity. If the cause is a pseudohanging columella, the therapy should be directed to the alar rims. When the deformity is a true hanging columella with unusually wide medial crural cartilages, balance can be restored by excising a C-shaped crescent of cartilage from the cranial border of the medial crura of the alar cartilages in a direct approach. This condition was present in approximately 15 percent of the patients reviewed. The treatment of a true hanging columella adds a subtle beneficial enhancement to the results of a rhinoplasty. The authors describe a simplified diagnostic method and present their experience treating the true hanging columella using a modified "direct approach" through a closed endonasal rhinoplasty.     

Mediastinoscopy Under Local Anesthesia—A Valuable Diagnostic Technique

Mediastinoscopy is an important, new endoscopic diagnostic technique. The simplicity of the technique and low morbidity and mortality associated with the procedure when carried out under local anesthesia suggest that in many instances mediastinoscopy for direct visualization and excision of biopsy specimens may replace diagnostic thoracotomy in many cases.     

The evaluation of liquid-based ''Cyto-SEDTM'' cytology of bronchioalveolar lavage specimens in the diagnosis of pulmonary neoplasia against conventional direct smears

Historically, bronchioalveolar lavage (BAL) samples have been prepared by a direct smear (DS) technique. Recent advances in liquid-based cytology have led to a revolution in cytological specimen preparation. Cyto-SED system (CS) is a manual liquid-based cytology system, designed for small-scale use. A total of 137 samples from patients with radiographically detectable lesions underwent BAL procedures at Papworth Hospital NHS Trust over a 4-month period. After preparation for diagnostic purposes with the DS method, the remaining sample was prepared using the CS system. The slides produced were allocated a blind study number and screened by three independent screeners. The cellular morphology was well preserved and comparable between both techniques. Of the 137 patients, 38% were confirmed as malignant by cytology or histology; 71% of these malignant diagnosis were confirmed by the DS technique and 91% confirmed by the CS. The results demonstrate that the CS is a viable alternative to the DS technique. The cytological detail is clearly defined without a loss of three-dimensional information, thus aiding the differential diagnosis of malignancy. Cyto-SED cytology system yields a higher diagnostic accuracy than the conventional direct smear technique without compromising on cytological detail.     

The use of optical spectroscopy in combinatorial chemistry.

Infrared and Raman spectroscopy allow direct spectral analysis of the solid-phase, thus avoiding the tedious cleavage of compounds from the solid support. With diagnostic bands in starting materials or products, infrared and Raman spectroscopy are efficient in monitoring each reaction step directly on the solid phase. Consequently, infrared and Raman spectroscopy have evolved as the premier analytical methodology for direct analysis on the solid support. While infrared transmission spectroscopy is a general analytical method for resin samples, internal reflection spectroscopy is especially suited for solid polymer substrates known as "pins" or "crowns." Single bead analysis is done best by infrared microspectroscopy, whereas photoacoustic spectroscopy allows totally nondestructive analysis of resin samples. With an automated accessory, diffuse reflection spectroscopy provides a method for high throughput on-bead monitoring of solid-phase reactions. Providing identification based on molecular structure, HPLC-FTIR is, therefore, complementary to LC-MS. Additionally, Raman spectroscopy as a complement to infrared spectroscopy can be applied to resin samples and-using a Raman microscope-to single beads. Fluorometry as an extremely sensitive spectroscopic detection method allows rapid quantification of organic reactions directly on the resin.     

Negative staining in diagnostic virology

Negative staining has been quickly developed since the early 1960s to a world wide used technique for the direct visualization of viruses and macromolecules by electron microscopy (see Hayat and Miller, 1990). In particular, negative staining has become an indispensable method in the rapid diagnosis of viral diseases.In this article we describe briefly the history and development and discuss some methodological and diagnostic aspects of negative staining in virology.