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PubMed2006

[Crystalluria].

Crystalluria is often present in routine urinalysis. The precipitation of crystals occurs in supersaturated urine. "Non-specific crystalluria" may be caused by food intake, pH and/or temperature changes of the urine, specially when urine is not analysed immediately. This randomly observed "non-specific crystalluria" is of no clinical value. In contrast, "specific" crystalluria can be associated with diseases such as nephrolithiasis, primary hyperoxaluria or ethylene glycol poisoning. Some drugs are excreted as crystals and may cause heavy crystalluria leading to kidney injury; this is the case of retroviral drugs and some antibiotics used in clinical practice. In these situations the diagnosis can be made by urinalysis and therapy be adapted accordingly. Important for the analysis of crystalluria is the correct handling of the fresh urine, knowledge of urinary pH and, of course, training in microscopic techniques.

Crystallization↗
PubMedDate not supplied

The need for vigilance in the pathologic evaluation of sentinel lymph nodes: a report of two illustrative cases.

The advent of sentinel lymph node (SLN) biopsy for breast cancer has had a considerable impact on clinical oncology. The SLN procedure has been widely adopted, but major clinical issues remain unresolved pending the outcome of randomized trials. Pathologic handling of SLNs is less controversial; however, significant pitfalls in their handling have been reported. Herein we report two additional uncommon situations that demonstrate the need for the utmost vigilance in both the macroscopic examination (i.e., trimming of "positive" nodal tissue) and microscopic examination (i.e., presence of nevus cell aggregates mimicking metastatic carcinoma) of SLN specimens.

Aged↗
PubMed1987

The evaluation and treatment of the sexually assaulted patient.

There are several significant problems encountered in treating the assault victim in the Emergency Department setting. In a busy Emergency Department, the patient who has been assaulted may be prioritized behind other patients with more significant life-threatening illnesses or injuries. The delay in treatment that ensues may aggravate the emotional trauma already experienced. Additionally, the legal and technical aspects involved in the evaluation and subsequent testimony may erect a psychological barrier on the part of the physician or nurse. This article provides guidelines and handling all of the above problems with regard to the sexually assaulted patient.

Contraceptives, Oral↗
PubMed1982

Factor XI assay results in the CAP survey (1981).

Data from the 1981 CAP Survey for factor XI assay is reviewed. Different instrument reagent combinations are ranked according to precision and sensitivity. Results of the survey questionnaire are analyzed. There is poor correlation between precision and sensitivity of most systems (i.e., instrument and reagent combinations). For any given system, precision appears to decrease with increasing severity of the factor XI deficiency of the specimen. Some comparisons are made to recent CAP surveys of factor VIII and IX activity. Considerable interlaboratory variation is noted with respect to technical aspects of factor assays (i.e., dilution of normal plasma used to construct the standard curve, etc.). Procedures used by some laboratories in handling patient specimens for factor assays, such as freezing the patient specimen, may decrease the chance of identifying a mild factor XI deficiency. The need for standardization of factor assays is evident from the survey data.

Factor XI↗
PubMed2006

Ashkenazi levites' "Y modal haplotype" (LMH)-- an artificially created phenomenon?

The article on the Y chromosomes of Ashkenazi Levites (Behar et al., 2003. Am. J. Hum. Genet. 73, 768-779) is the fourth in a series on the Y chromosomes of the three Jewish male castes: Cohanim (priests), Levites (priests' helpers) and Israelites (lay people). It became apparent that there is a problem with omission of samples when the second article "Origins of Old Testament priests" (Thomas et al., 1998. Nature 394, 138-140) was published. In the fourth article a remarkable 55% of the Ashkenazi Levite samples from the earlier 1998 study are not included. This causes the "Levite modal haplotype" to double its frequency from 21% of the Ashkenazi Levite sample in 1998 to 42% of the Ashkenazi Levite sample in 2003. The authors offer three main explanations: (1) The studies are independent using different sample sets.(2) Typing errors and poor quality exclude samples from future studies.(3) Correction of typing errors means that some samples are classified under different haplotypes. The explanations offered to the problem of omitting samples from subsequent studies after their haplotypes or partial haplotypes are known, are not convincing. Consequently their sample sets cannot be considered random and non-biased. At the least, these laboratories have bad practices of sample handling and many typing errors, which are enough to invalidate their studies.

Chromosomes, Human, Y↗
PubMed1982

Evaluation of the cutaneous-irritation potential of 56 compounds.

The primary cutaneous irritation of 56 chemicals was tested in the rabbit using three different procedures. The three protocols selected for the tests were the method published by the French authorities for the testing of cosmetics and toiletries (Journal Officiel 21 April 1973, p. 3862; ibid 5 June 1973, p. 3953) and the methods proposed for the testing of chemicals by the Association Française de Normalisation (AFNOR) and, in 1979, by the Organisation for Economic Co-operation and Development. The results of the three sets of tests were compared and the effects of differences in procedure and numbers of animals were studied, together with the possible relation between irritancy and the pH of the test material. It was concluded that the AFNOR protocol best met the requirements for such tests and that gloves should be worn for the handling of all substances classified as moderately or severely irritant on that scale.

Animals↗
PubMed2003

Housing and husbandry of Xenopus for oocyte production.

Despite their importance as a research model, particularly in developmental toxicology investigations, there are few established standards for maintaining Xenopus spp. frogs in the laboratory. The authors review the literature on handling, housing, nutrition, and breeding of Xenopus spp. for optimal oocyte production.

Animal Husbandry↗
PubMed1999

Procurement of population-based cancer tissue in Iowa.

We describe the first systematic survey of pathology laboratories serving Iowans to assess attitudes concerning assistance with cancer research efforts. Previous reports suggested that pathologists are reluctant to loan slides and/or paraffin tissue blocks for research purposes because of potential loss or damage, medicolegal concerns, or lack of compensation for time and effort spent in retrieving materials. In this study, we obtained survey responses from laboratory directors of 54 of the 56 pathology laboratories serving Iowans. The survey covered issues related to the availability of research materials, reimbursement for the retrieval of materials, and turnaround time for returning borrowed materials. Contrary to previous reports, we found that the laboratory directors surveyed were willing to loan slides and blocks for research purposes, provided that confidentiality is maintained, that the materials are handled properly and returned in a timely manner, and that compensation is provided.

Data Collection↗
PubMed1986

Nonsquamous neoplasms of the larynx.

While squamous cell carcinoma is the most common neoplasm to involve the larynx, several other histologic tumor types can occur. The laryngologist should consider a nonsquamous neoplasm when the tumor is long-standing, pigmented, covered by intact mucosa, or there is a history of neoplasia. Careful endoscopy, often using microlaryngoscopy, and careful handling of the tissue will ensure accurate diagnosis.

Adenoma↗
PubMed1995

The effect of storage on immunophenotyping of sheep peripheral blood lymphocytes by flow cytometry.

We have shown that when a whole blood method of cell staining is used for flow cytometric analysis of sheep lymphocytes (i.e. red cell lysis after addition of antibody), staining may be delayed for up to 48 h after blood collection without significant effect on expression of CD4, CD5, CD8 or B cell markers. If cells were stained immediately after blood collection, using the same whole blood method, and then fixed with paraformaldehyde, cell samples could be stored for 24 h without change in marker expression. However, by 7 days there was a significant decrease in the percentage of cells expressing CD8, T19 and B cell markers. Cryopreservation prior to staining was found to markedly affect the expression of all cell surface markers investigated. These results indicate that storage of sheep blood prior to flow cytometric analysis is feasible but may affect the results obtained. Thus is it important to standardise the handling of samples, especially when comparative studies are being undertaken.

Animals↗
PubMed1997

Assessment of homocysteine status.

Plasma total homocysteine (tHcy) determination is used in the diagnosis of homocystinuria, in cobalamin and folate deficiency and in cardiovascular risk assessment. However, determination of tHcy includes many pitfalls which complicate the assessment of homocysteine status. In the present article, we review basic knowledge for a rational use of plasma tHcy in diagnostic as well as scientific work. The subjects dealt with are procedures for sample handling and processing, the principles of tHcy analyses, and genetic and acquired determinants of the plasma tHcy concentration.

Animals↗
PubMed1991

Commentary: the acquisition and use of human brain tissue in neuropsychiatric research.

Witelson and McCulloch (1991) report on the establishment of a collection of normal human brain tissue that was secured through a unique method of premortem and postmortem assessments. Their work highlights the growing need in neuro-scientific research for carefully characterized collections of human brain tissue from both normal control subjects and patients with specific neuropsychiatric disorders. Brain tissue of this type, however, has not been readily available. Patients with mental disorders may not be competent to consent to a postmortem brain donation; other obstacles include various socioeconomic and legal impediments to autopsies. In addition, a number of methodologic issues exist regarding human brain tissue collections, including the problem of standardized postmortem diagnostic assessment and difficulty in establishing uniform procedures for processing formalin-fixed and frozen tissue. Various proposals to enhance brain-tissue collections are discussed. These include the establishment of networks for tissue donation and use, the linking of ultimate postmortem brain tissue collection to prospective clinical studies, and promulgation of standardized procedures for methods of postmortem diagnosis and tissue handling.

Adult↗
PubMed2005

Validation of the Nova CRT8 for the measurement of ionized magnesium in feline serum.

BACKGROUND: Evaluation of serum magnesium (Mg) concentration is becoming important in human and veterinary critical care medicine. An ion-selective electrode can measure the physiologically active ionized fraction. OBJECTIVES: The purpose of this study was to validate an ion-specific electrode analyzer and assay for measuring ionized Mg in feline serum and to determine a reference interval for this analyte in cats. METHODS: Venous blood samples were collected anaerobically from clinically healthy cats, and the serum was used to validate the analyzer and assay. This included investigating the stability of samples stored at different temperatures, intra- and interassay precision, linearity, analytical sensitivity, and potential interferences from bilirubin, lipemia, hemoglobin, or serum separator tubes. A reference interval was calculated. RESULTS: Serum samples evaluated for ionized Mg concentrations can be stored at 20 degrees C for < or =24 hours, at 4 degrees C for < or =72 hours, and at 20 degrees C for < or =4 weeks, when samples are minimally exposed to air. Intra- and interassay precisions had coefficients of variation (CVs) of 1.23% and 2.02%, respectively. There was good linearity using serum (r = .998; y = -0.0057 + 1.0256x) and manufacturer-supplied aqueous solutions and quality control materials (r = .999; y = 0.0110 + 0.9213x). Apparent analytical sensitivity was at least 0.015 mmol/L. Mean recovery was good for ionized Mg in samples with 1+ icterus (104%), 4+ lipemia (99.3%) and 1-4+ hemolysis (98.6%). There was no significant difference (P = .52) in ionized Mg concentrations in serum collected in tubes containing no additives compared with serum collected in glass separator tubes. The serum ionized Mg reference interval was 0.47-0.63 mmol/L (n = 40). CONCLUSIONS: The Nova CRT8 analyzer and assay provide a precise and reliable method of measuring ionized Mg concentration in feline serum. Strict adherence to sampling techniques, handling, and storage are necessary for reliable results.

Animals↗
PubMed1995

[Sources of error in the pre-analytical phase of blood gas analysis].

Analysis of blood gases and blood pH yield important information in many situations of clinical emergencies. We report on a patient in whom pre-analytic errors in blood gas and blood pH measurements resulted in unnecessary further investigations. We therefore studied various pre-analytic sources of error in blood pH and blood gas analysis. Delay in sample processing for more than one hour resulted in an increase of pO2 and pCO2 and a decrease of pH. Excess sodium heparin solution as an anticoagulant (> or = 10% of total volume) led to a significant decrease of pH and pCO2 and to an increase of pO2. Air bubbles (10% of total volume) left in the syringe for 10 min significantly increased pO2. For accurate estimations of pO2, pCO2 and pH, it is necessary to keep the heparin solution below 10% of total volume, to expel all air bubbles from the syringe and to process the blood sample within one hour. Instructions to medical staff on handling blood samples for blood gas analysis should include these possible sources of errors.

Aged↗