Journal of Laboratory and Clinical Medicine最新文献

In our genome-wide survey of gene expression in human peripheral blood cells using both an expressed sequence tag (EST) and a microarray hybridization approach, we identified the expression of a large proportion (approximately 80%) of the genes encoded in the human genome. Comparison of the peripheral blood transcriptome with genes expressed in nine different human tissue types revealed that expression of over 80% was shared with any given tissue. We also sought to determine whether those gene transcripts undetected by these methods were also expressed in peripheral blood cells. Using reverse-transcriptase-polymerase chain reaction, we detected additional tissue-specific gene transcripts including beta-myosin heavy chain (heart specific) and insulin (specific to pancreatic islet beta cells), in circulating blood cells. Arguably, the detection of low levels of tissue-specific transcripts could be considered products of “illegitimate” transcription; however, our study also demonstrates that environmental conditions affect the transcriptional regulation of insulin in the peripheral blood. We thus hypothesize that blood cells can act as sentinels of disease and that we could capitalize on this property of blood for the diagnosis/prognosis of disease (the “Sentinel Principle”). Peripheral blood is an ideal surrogate tissue as it is readily obtainable, provides a large biosensor pool in the form of gene transcripts, and response to changes in the macro- and micro-environments is detectable as alterations in the levels of these gene transcripts.

Cytotoxic drugs were designed to kill tumor cells, whereas agents of molecular targeted therapy inhibit various molecular functions of the tumor cell. Consequently, their toxicity profiles also differ. Molecular targeted agents, except for monoclonal antibodies, are enumerated here in three classes: compounds active extracellularly, extra/intracellularly, and intracellularly. Although no major breakthrough has occurred in the drug treatment of neoplastic diseases yet, such compounds as trastuzumab, cetuximab, bevacizumab, gefitinib, erlotinib, imatinib, and bortezomib have shown considerable clinical promise. Major obstacles to the further development of molecular targeted compounds are described. The use of different endpoints, positron emission tomography for evaluation, and predictive genetic markers are recommended. Combination therapy with cytotoxic drugs and studies in an adjuvant setting are also recommended. It is concluded that cautious optimism about the future of molecular targeted therapy is reasonable.

Although “unmeasured” anions contribute to metabolic acidosis in a variety of disease states, they are generally not measured directly but estimated from the calculation of “gaps.” Among the most commonly used method, the anion gap (AG) is not only a function of “unmeasured” anions, but also it is a function of plasma non-carbonate buffers (albumin and phosphate), the plasma pH, and the method of measurement. To clarify the contribution of non-carbonate buffers to the AG, the Figge–Fencl–Waston model of human plasma was applied to laboratory values obtained from two novel populations, patients with nephrotic syndrome and patients with diabetic ketoacidosis (DKA). The model performed adequately, justifying the common clinical practice of correcting the AG for the net protein charge.

In a rat model of macrophage-dependent glomerular immune injury induced by administration of antibody against the glomerular basement membrane (anti-GBM), the authors assessed the anti-proteinuric effect of Heme Oxygenase-1 (HO-1) induction. Rats received anti-GBM antibody alone, anti-GBM antibody and treatment with the HO-1 inducer, hemin, or non-immune serum (controls). Urine protein, creatinine, and nitrite/nitrate excretion were measured on days 5, 7, and 14 after administration of the anti-GBM antibody. In hemin-treated animals with anti-GBM antibody-induced immune injury, HO-1 immunolocalized in macrophages infiltrating glomeruli and in tubular epithelial cells. In these animals, proteinuria was decreased. There was also a decrease in blood urea nitrogen (BUN) levels without a change in serum creatinine or systemic blood pressure. The observations establish the anti-proteinuric effect of hemin induction. This effect could be mechanistically linked to blunting of the ability of infiltrating macrophages to cause injury or to changes in tubular handling of filtered protein.

Background: Fatty acid ethyl esters (FAEEs) are useful markers of ongoing alcohol use and may be associated with alcohol-induced damage to the liver and pancreas. In this article, we describe a novel method for rapid determination of the three major FAEEs found in human plasma. Methods: Internal standard, ethyl heptadecanoate, was added to plasma samples, and FAEEs were isolated by acetone precipitation, hexane lipid extraction, and amino-propyl silica solid phase extraction. FAEEs were quantitated by gas chromatography-mass spectrometry (GC-MS) using a nonpolar dimethylpolysiloxane column. The accuracy, precision, specificity, and sensitivity of the assay were defined from plasma samples from recently drinking and abstinent persons, with and without the addition of FAEEs. Results: Individual FAEE peaks demonstrated excellent resolution. Instrument time was reduced by more than 60%. The lower limit of detection was 5 to 10 nM, and the lower limit of quantitation for each FAEE was 60 nM (for 22 samples with known concentration 60 nM, × ±SD: 61 ± 5.7, 57 ± 5.7, and 57 ± 5.9 nM, for ethyl palmitate, ethyl oleate, and ethyl stearate, respectively). Instrument precision (coefficient of variance, CV) for these three FAEEs was 0.3%, 0.4%, and 0.7%, respectively. Intra-assay precision (CV) for total FAEEs was less than 7%. FAEEs were absent in 49 samples from abstinent persons. FAEEs were detected in all 76 samples with associated positive blood alcohol levels. Conclusions: Our method of FAEE analysis is rapid and potentially useful in research and clinical studies. FAEE determination using this method is precise, accurate, sensitive, and specific and deserves broader application.

Noninvasive methods to diagnose the infection status of Helicobacter pylori were a new developed trend. In this study, the authors sought to investigate the difference between a new office-based stool immunoassay (ImmunoCard STAT! HpSA) and ¹³C-Urea Breath Test (¹³C-UBT). We studied 254 dyspeptic patients (159 men, 95 women; mean age = 52.8 ± 14.3 years, range: 19–89 years). All of them underwent gastroendoscopy, ¹³C-UBT test, and delivered stool samples within 3 days after endoscopy for the ImmunoCard STAT! HpSA test. The exclusion criteria were those who (1) had received previous anti-Hp treatment, proton pump inhibitor, antibiotics, or bismuth within 1 month of endoscopic examination; (2) had bleeding peptic ulcers; (3) had previously undergone gastric surgery; (4) had long-term use of corticosteroid or immunosuppressant drugs; (5) were pregnant or lactating; and (6) had incomplete data. Hp infection was considered positive when either culture was positive, or both histology and rapid urea test were positive. Those patients were classified as pre- and post-Hp treatment groups. Those in the post-treatment group were patients who received Hp eradication therapy at our hospital more than 2 months ago. The overall sensitivity, specificity, and positive and negative predictive values of ¹³C-UBT and ImmunoCard STAT! HpSA were 96.3%, 87.6%, 85.4%, 96.9%, and 95.4%, 83.4%, 81.3%, 96.0%, respectively. The sensitivity, specificity, and accuracy of both tests are comparable in the pre- and post- treatment groups. The advantages of ImmunoCard STAT! HpSA over a breath test are that it is cheaper, more time-saving, and can be used in-office.

We investigated in detail the difference between serum and plasma potassium levels in patients with several conditions associated with pseudohyperkalemia. In total, 435 patients with either thrombocytoses, erythrocytoses, leucocytoses, or a mixed-type disorder and 30 healthy controls were included. In each case, the index Dk [serum potassium minus plasma potassium] and the index Dk100 (Dk × 100,000/platelets), which indicates the Dk value that corresponds to platelets of 100,000/mm³, were estimated. Median Dk was significantly higher in the groups with platelet, erythrocyte, or mixed-type disorders than in the controls (P = 0.001). Among these groups, Dk values were significantly higher in patients with thrombocytosis or mixed-type disorders compared with those with erythrocytosis (P < 0.001, for both). Furthermore, no significant difference was observed in Dk values between controls and patients with white blood cell disorders (P = 0.74). Dk values did not exceed 2.61 mmol/L, whereas Dk100 values were inversely related to platelet counts (r = −0.351, P < 0.01). In conclusion, pseudohyperkalemia is mainly present in patients with thrombocytosis or mixed-type disorders, probably as a result of the degranulation of platelets, which offers a potassium load to the surrounding plasma at the time of clot formation in vitro. However, the degree of pseudohyperkalemia does not increase proportionally with the increase of platelet counts, which may be associated with transfer of part of potassium load from the plasma back into red and white blood cells.