Comparison of ERCC1/XPF genetic variation, mRNA and protein levels in women with advanced stage ovarian cancer treated with intraperitoneal platinum.

Objective: Approximately 20% of patients receiving platinum-based chemotherapy for epithelial ovarian cancer (EOC) are refractory or develop early recurrence. Identifying these patients early could reduce treatment-associated morbidity and allow quicker transfer to more effective therapies. Much attention has focused on ERCC1 as a potential predictor of response to therapy because of its essential role in the repair of platinum-induced DNA damage.

A telephone survey of cancer awareness among frontline staff: informing training needs.

Background: Studies have shown limited awareness about cancer risk factors among hospital-based staff. Less is known about general cancer awareness among community frontline National Health Service and social care staff.

Methods: A cross-sectional computer-assisted telephone survey of 4664 frontline community-based health and social care staff in North West England.

Evaluating selenium poisoning.

Selenium poisoning in humans is reviewed from the perspective of the clinical laboratory. While evaluation of selenium poisoning is straightforward when the analytic results are markedly elevated and the patient is acutely symptomatic, distinguishing toxic from non-toxic elevations is a more frequent issue and more challenging. A significant problem is that selenium is determined as its total concentration in spite of the fact that different chemical forms of selenium have different toxic potentials.

Interpreting hair mercury levels in individual patients.

Evaluation of mercury exposure in an individual patient ideally includes the presenting history, physical examination, consideration of the differential diagnosis, and mercury analysis of blood and urine specimens. Analysis of mercury in hair specimens may supply useful supplemental information about exposure to organic compounds such as methylmercury, particularly to help reconstruct the pattern of prior exposure. The most appropriate specimen is generally terminal-type hair from the occipital-neck junction, clamped to maintain strand alignment, and oriented to the scalp.

Interpreting mercury in blood and urine of individual patients.

The effects of mercury exposure are determined by: (a) chemical form, (b) route of exposure, (c) dose, and (d) patient factors. Patient factors include age, genetics, environmental aspects, and nutritional status, and are responsible for different individual responses to similar doses. When blood and urine are collected to evaluate exposure, the results are influenced by (a) specimen collection, (b) analysis, and (c) the time elapsed from exposure.

Reference limits for copper and iron in liver biopsies.

Using 141 liver biopsy results (103 adults, 38 children) and a rank-order approach, the following reference limits were found: copper 55 microg/g dry weight, iron 1800 microg/g dry weight (adults only), and iron index 1.0. The study was made feasible by the fact that both copper and iron were measured as standard practice in every liver biopsy received for either test.

Abnormal chromatographic patterns of porphyrins in urine.

Urine is the most frequent specimen used in the initial evaluation of adult patients who present with photosensitivity. When urine porphyrins are abnormal, characterization of the chromatogram is facilitated by calculation of uroporphyrin-to-heptacarboxylate porphyrin (uro/hepta) and uroporphyrin-to-isocoproporphyrin (uro/iso) ratios. The most frequent abnormal pattern, and that most consistent with porphyria cutanea tarda (PCT), is an uro/hepta ratio < or =2.

Maternal serum alpha-fetoprotein and altitude.

Maternal serum alpha-fetoprotein (MS-alphaFP) testing is widely used to screen for fetal defects. MS-alphaFP concentrations are affected by a number of variables such as gestational age, maternal weight, number of fetuses, race, and insulin-dependent diabetes. Undefined geographic factors may also influence MS-alphaFP.

Identifying delayed separation in plasma homocysteine specimens.

The delayed separation of plasma from the cellular components of blood can lead to falsely elevated homocysteine results. The incidence of delayed separation in patient specimens was examined by using the ratio of arginine to the sum of arginine plus ornithine [arg/(arg + orn)], a ratio <0.50 being consistent with delayed separation.

Evaluating serum alpha-tocopherol (vitamin E) in terms of a lipid ratio.

It is well known that accurate assessment of serum alpha-tocopherol requires knowledge of the serum lipids also present. Patient specimens (n = 307) within the standard reference limit of 5-18 mg/L were used to determine the following 95 percent reference interval for a lipid ratio of alpha-tocopherol to the sum of cholesterol and triglycerides [E/(C + T)]: 1.4 (1.

Delayed separation and the plasma amino acids arginine and ornithine.

When collecting blood for amino acid testing, leaving plasma in contact with cells at room temperature lowers the concentration of arginine and raises that of ornithine. This is presumably due to the arginase content of red blood cells. In contrast, the sum of arginine and ornithine is constant over the first hour, and defines a reference interval of 74-148 mumol/L (mean +/- 2 SD, n = 20) which is more insensitive to delayed separation.

The incidence of elevations in urine 5-hydroxyindoleacetic acid.

A 24-hour urine collection for 5-hydroxyindoleacetic acid (HIAA) is commonly performed to evaluate patients with suspected carcinoid syndrome. However, carcinoids are rare, and elevated results are common even when using an analytically specific method. To characterize this problem, the incidence of elevated results was examined in a population of 947 patient specimens received in a clinical reference laboratory setting.

Suspected lead poisoning in a public school.

Reports of lead exposure can generate considerable public concern, particularly when children are involved. In December, 1996, a public elementary school in rural Utah was found to have elevated concentrations of lead in its drinking water. The local public health department responded by instituting remediation of the water supply and by warning parents of the possible danger to their children.

Effect of storage on serum vitamin B12 and folate stability.

To facilitate transport from remote locations, the stability of vitamin B12 and folate was investigated in serum specimens. Serum vitamin B12 proved to be highly unstable, emphasizing that specimens should be frozen if not analyzed immediately. Light protection is necessary if the sample cannot be analyzed within 4 hours.

The adequacy of capillary specimens for determining whole blood lead.

In response to demands for reliable alternatives to collection of venous specimens for determination of whole blood lead levels in children, the Centers for Disease Control has called for increased research into capillary methodologies. In this study, a three tiered approach was developed to assess the adequacy of capillary specimens for determining whole blood lead. Patient blood lead results from capillary and venous specimens were compared for obvious differences.

Serum succinate by capillary zone electrophoresis: marker candidate for hypoxia.

Serum succinate may offer an alternate analyte to lactate for the evaluation of hypoxia. To evaluate the potential uses of succinate, a relatively rapid capillary zone electrophoresis assay was developed for use in the clinical laboratory setting. Employing a simple indirect ultraviolet detection method with commercially available instrumentation, the limit of detection for serum succinate was determined to be 0.

Testing for inborn errors of metabolism in the acutely ill newborn.

The differential diagnosis of the acutely ill newborn should include inborn errors of metabolism along with much more common conditions such as sepsis and hypoxemia. Testing recommendations, which can take place simultaneously with other studies, are presented for the evaluation of inborn errors in acutely ill newborns. Initial hospital-based tests include arterial blood gases, glucose, electrolytes, urinalysis, complete blood count, and cultures.

Orotic acid in clinical urine specimens by capillary zone electrophoresis using polyvinyl alcohol coated capillaries.

Orotic acid is an important compound in the investigation of several inherited metabolic diseases, and capillary zone electrophoresis provides an effective assay method for this analyte in the clinical laboratory setting. Capillaries with a polyvinyl alcohol (PVA) coating performed well in this application. However, it was necessary to employ several specimen preparation steps to achieve good assay precision.

Reference intervals for 24-hour and random urine porphyrins.

Urine porphyrin analysis is an important part in evaluation of photosensitivity. Since porphyrin excretion is variable throughout the day, analysis is traditionally based on 24-hour collections. To facilitate the use of random specimens, as well as poorly collected 24-hour specimens, reference limits based on the porphyrin to creatinine ratio have been developed.