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At least 19 recordsLinked to original sources
PubMed1979

Pneumocystis carinii pneumonia. An approach to rapid laboratory diagnosis.

Laboratory procedures used to establish the diagnosis of Pneumocystis carinii pneumonia were evaluated using an experimental murine model. Touch preparations and suspension smears were prepared from lung tissue know to contain Pneumocystis cysts. These preparations were stained by a variety of methods known to demonstrate either cyst forms or sporozoites and trophozoites. Suspension smears proved to be superior to touch preparations in terms of cyst content and homogeneity of staining. Also, methods that stain cyst forms were superior to those that stain sporozoites and trophozoites for location and identification of organisms. The authors believe that suspension smears prepared from lung tissue and stained with toluidine blue O should be examined initially as a rapid screening method for Pneumocystis cysts. When the results of this initial screen are negative or inconclusive, additional suspension smears stainded by the modified Gomori methenamine silver nitrate method should be examined, pending availability of histologic sections.

Animals↗
PubMedDate not supplied

[Metrological problems of laboratory diagnosis].

Medical laboratory diagnosis is progressing from one analysis to a group of analysis with rather intricate statistical processing of data via multidimensional analysis, at the same time it is necessary to define a patient's individual normal levels, i.e. a "health certificate". In this regard, the process may be achieved when complex analyzers, which have a reliable metrological support, and systems for collection of both clinical and laboratory information and its simultaneous analysis are put into laboratories' practical work.

Clinical Laboratory Techniques↗
PubMed1999

Basic problems of serological laboratory diagnosis.

Serological laboratory diagnosis is inflicted with at least two kinds of basic problems. One type relates to the fact that the serological diagnosis of infectious diseases is double indirect: First, to diagnose an infectious disease, the identification of the microbial agent is sought that caused the disease. Second, to identify this infectious agent, the patient's immune response to potential agents is measured. So, the serological test is neither measuring directly disease nor the cause of the disease, but the patient's immune system. Another type of problem is based on the fact that each person's immune system is very individual. The exact physicochemical properties of antibodies are unique for each clone of antibodies. The way an individual's immune system sees an infectious agent depends not only on the genetic makeup of the person but also on the personal experience from former encounters with infectious agents. Both types of problems lead to complexities in selecting the appropriate test, in interpreting the results, and in standardizing serological tests. Therefore, a close collaboration of the laboratory with the clinic is mandatory to avoid erroneous conclusions from serological test results, which might lead to wrong decisions in patient care.

Clinical Laboratory Techniques↗
PubMed2004

Basic problems of serological laboratory diagnosis.

Serological laboratory diagnosis of infectious diseases is inflicted with several kinds of basic problems. One difficulty relates to the fact that the serological diagnosis of infectious diseases is double indirect: The first indirect aim in diagnosing an infectious disease is to identify the microbial agent that caused the disease. The second indirect aim is to identify this infectious agent by measuring the patient's immune response to the potential agent. Thus, the serological test is neither measuring directly disease nor the cause of the disease, but the patient's immune system. The latter poses another type of problem, because each person's immune system is unique. The immune response to an infectious agent is usually of polyclonal nature, and the exact physicochemical properties of antibodies are unique for each clone of antibody. The clonal makeup and composition and, therefore, the way an individual's immune system sees an infectious agent, depends not only on the genetic background of the person but also on the individual experience from former encounters with various infectious agents. In consequence, the reaction of a patient's serum in an analytical system is not precisely predictable. Also, the antigenic makeup of an infectious agent is not always foreseeable. Antigenic variations leading to different serotypes is a quite common phenomenon. Altogether, these biological problems lead to complexities in selecting the appropriate tests and strategies for testing, in interpreting the results, and in standardizing serological test systems. For that reason, a close collaboration of the laboratory with the clinic is mandatory to avoid erroneous conclusions from serological test results, which might lead to wrong decisions in patient care.

Antibody Affinity↗
PubMed1991

Laboratory diagnosis of pneumocystosis.

Laboratory diagnosis of pneumocystosis requires that appropriate specimens be properly obtained, that these specimens be appropriately processed in the laboratory, examined by competent personnel, and reported in a timely fashion. The laboratory section that performs the evaluation and the methods and stains used vary depending on the interests and capabilities of persons at each institution.

Acquired Immunodeficiency Syndrome↗
PubMed1981

The centralized prenatal genetics screening program of New York City: II. Establishment of prenatal diagnosis laboratory.

Prenatal diagnosis of genetic disorders is now being made available to an increasing number of New York City women through the establishment of a large centralized laboratory. This laboratory contracts to provide genetic diagnostic services to municipal and private hospitals throughout the New York City area. It is the first project of such magnitude in the United States. Prior to the receipt of samples for diagnostic purposes, the laboratory was required to meet the highest technical standards, as established by a Cytogenetics Advisory Committee. A set of guidelines was drawn up detailing the procedure and protocols for all the analyses and the reporting of results, including a timetable according to which results were to be obtained. The Cytogenetics Advisory Committee continues to review cases on a regular schedule. One of the unique aspects of the laboratory has been the development of back-up agreements with other area laboratories to assist in dealing with any problem that might disrupt the routine diagnostic service. The first year of operation of the laboratory has shown that financial, legal, and physical problems associated with designing and instituting a megacenter can be over-come. Similar programs should be encouraged.

Female↗
PubMed1985

Laboratory diagnosis of herpesviruses.

Laboratory diagnosis is made either by demonstration of the presence of virus, viral antigens or virus-specific nucleic acid sequences in suitable specimens or by measurement of antibodies--rise in titer or presence of viral-specific IgM--in blood samples from the patients. A number of biological features characteristic for the herpes viruses can be utilised for detection: the infectivity (isolation in tissue culture), the morphology (visualisation by electronmicroscopy), the antigenicity of viral specified proteins produced by infected cells (immunofluorescence, ELISA and RIA), and unique sequences in viral DNA (hybridisation). The different methods are described and evaluated in regard to viral detectability and speed of performance. Concerning diagnostic serology only the ELISA systems for measurement of viral-specific IgG, total antibodies and IgM have been described because these methods now have been introduced in most viral diagnostic laboratories, and many commercial available kits also operate according to these techniques.

Antibodies, Viral↗
PubMed1999

Laboratory diagnosis of respiratory infections.

The laboratory diagnosis of infections of the respiratory tract is not an exact science, with many clinicians electing to empirically select antimicrobial therapy without the benefit of laboratory testing. With trained laboratory personnel and the proper selection of tests, accurate laboratory diagnosis is available. Progress is occurring most rapidly with molecular methods, such as polymerase chain reaction (PCR) testing. As molecular approaches are technically simplified and become less expensive, advances in the laboratory diagnosis of most respiratory tract infections caused by fastidious pathogens will occur. The diagnosis of non-fastidious bacteria, that require in-vitro antimicrobial testing, will continue to require conventional culture methods. New bronchoscopic methods, quantitative evaluation of cultures, and recognition of intracellular bacteria in stained smears do improve the usefulness of conventional culture and stain in the diagnosis of pneumonia.

Journal Article↗
PubMed1998

The laboratory diagnosis of haemoglobinopathies.

The laboratory diagnosis of haemoglobinopathies, including the thalassaemias, is of growing importance, particularly because of an increasing requirement for antenatal diagnosis of significant disorders of globin chain synthesis. This guideline discusses the laboratory tests which are most useful in the diagnosis of haemoglobinopathies and describes their role in specific clinical circumstances. Of the newer technical methods, high-performance liquid chromatography (HPLC) is of considerable importance whereas isoelectric focusing (IEF) and immunoassay for variant haemoglobins have a more minor role. Specific recommendations have been formulated for testing in relation to genetic counselling and for neonatal diagnosis. Methods used in specialized laboratories for fetal diagnosis have been tabulated. Genetic counselling requires: (i) identification of haemoglobins S, C, D-Punjab, O-Arab, E, Lepore and H, and (ii) the detection of carriers of alpha(0) and beta thalassaemia. It is recommended that subjects of all ethnic groups be screened for beta-thalassaemia trait, all except Northern European Caucasians for variant haemoglobins, and selected ethnic groups for alpha(0)-thalassaemia trait. Testing for beta-thalassaemia trait should be carried out when the mean cellular haemoglobin (MCH) is < 27 pg and testing for alpha(0)-thalassaemia trait should be considered when the MCH is < 25 pg. Appropriate methods include HPLC or haemoglobin electrophoresis for identification of variant haemoglobins and HPLC or microcolumn chromatography for quantification of haemoglobin A2.

Blood Cell Count↗