Showing papers in "Journal of Clinical Laboratory Analysis in 1999"
TL;DR: In this article, the authors report reference ranges for serum levels of albumin, transferrin, and transthyretin based on a cohort of over 124,000 Caucasian individuals from northern New England, tested in their laboratory between 1986 and 1998.
Abstract: Inflammation is associated with diverse clinical conditions accompanied by characteristic changes in serum levels of the acute-phase proteins that can be used to stage the inflammatory process and evaluate the impact of treatment. Some acute-phase proteins increase during inflammation, while others, such as albumin, transferrin, and transthyretin, decrease. The current study reports reference ranges for serum levels of albumin, transferrin, and transthyretin based on a cohort of over 124,000 Caucasian individuals from northern New England, tested in our laboratory between 1986 and 1998. Measurements were standardized against CRM 470 (RPPHS) and analyzed using a previously validated statistical approach. Individuals with laboratory evidence of inflammation (C-reactive protein of 10 mg/L or higher) were excluded. The levels of all three analytes varied by age, generally rising until the second or third decade of life and then decreasing thereafter. Albumin and transthyretin levels were higher during midlife among males as compared to females; the maximum being at 25 years for albumin (5%) and 35 years for transthyretin (16%). In contrast, above the age of 10 years, transferrin levels were increasingly higher among females (7% at 20 years). When values were expressed as multiples of the age- and gender-specific median levels, the resulting distributions fitted a log-Gaussian distribution. When patient data are normalized in this manner, the distribution parameters can be used to assign a corresponding centile to an individual's measurement simplifying interpretation. The ultimate interpretation of an individual's measurement relies upon the clinical setting.
260 citations
TL;DR: The observations suggest that levels of IGFs and their binding proteins are varied with age, gender, and types of specimen and that these variations need to be taken into consideration when IGF's and theirbinding proteins are utilized in clinic and research.
Abstract: Insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) play an important role in cell growth and differentiation. Clinical and epidemiological studies have indicated that measuring IGFs and IGFBPs in blood has potential implications in assessing growth-related abnormalities and risks of certain types of cancer. To facilitate the application, we reported a large collection of reference ranges of IGFs and IGFBPs in normal population and evaluations of these molecules in serum and plasma as well as the impact of freeze-thaw cycles on the measurement. IGF-I, IGFBP-3 and ALS showed a similar pattern of change associated with age. Levels of these molecules were low at birth and increased with age through puberty. After puberty the levels declined slowly with age. Overall, IGF-I, IGFBP-3 and ALS were slightly higher in females than in males. Free IGF-I accounted for about 1% of the total IGF-I and its variation with age was similar to total IGF-I. IGF-II levels were also increased with age from birth to puberty, but became stable after puberty. There was little difference in IGF-II levels between genders. IGFBP-2 levels declined with age from birth to puberty. Levels of IGFBP-6 in contrast were increased with age. These IGF binding proteins were higher in males than in females. IGFs, IGFBP-3 and ALS were 5-10% higher in serum than in plasma. IGFBP-2 and IGFBP-6 differed substantially between serum and plasma. Freeze-thaw treatment up to five cycles had little impact on plasma levels of IGFs and IGFBP-3. Our observations suggest that levels of IGFs and their binding proteins are varied with age, gender, and types of specimen and that these variations need to be taken into consideration when IGFs and their binding proteins are utilized in clinic and research. J. Clin. Lab. Anal. 13:166–172, 1999. © 1999 Wiley-Liss, Inc.
193 citations
TL;DR: PCR was clearly interfered with when heparinized blood was used as a source of template DNA, and the degree of interference was affected by the following three factors; type of Taq DNA polymerase; leukocyte count in blood; and concentration of heparIn contained.
Abstract: Polymerase chain reaction (PCR) has been used with increasing frequency to diagnose infectious and genetic diseases. In this study, the effects of heparin on PCR were investigated, because heparinized blood may sometimes be used in PCR studies. HLA-DQA1 gene amplification was used as a model. PCR was clearly interfered with when heparinized blood was used as a source of template DNA, and the degree of interference was affected by the following three factors; (1) type of Taq DNA polymerase; (2) leukocyte count in blood; and (3) concentration of heparin contained. When additional tests were conducted with additions of definite heparin concentrations to a PCR reaction mixture, specimens with large amounts of DNA tended to exhibit less interference by heparin. The addition of > or = 0.1 to 0.0016 U of heparin per reaction mixture (50 microl) suppressed DNA amplification in a dose-dependent fashion. We therefore concluded that much care should be taken when heparinized blood is used as a PCR material.
121 citations
TL;DR: This assay provides a reproducible and accurate laboratory test for diagnosing the Glucose‐Transporter‐Protein Syndrome (GTPS), characterized by infantile epilepsy, developmental delay, and acquired microcephaly.
Abstract: Glucose transport into the brain is mediated by a facilitative glucose-transporter protein, GLUT-1. A GLUT-1 defect results in the Glucose-Transporter-Protein Syndrome (GTPS), characterized by infantile epilepsy, developmental delay, and acquired microcephaly. The diagnosis is currently based on clinical features, low to normal lactate levels and low glucose levels (hypoglycorrhachia) in the cerebrospinal fluid, and the demonstration of impaired GLUT-1 function in erythrocytes as described here. Blood samples were collected in sodium-heparin or citrate-phosphate-dextrose solution and uptake of 14C-labeled 3-O-Methyl-D-glucose (3OMG into erythrocytes (0.5 mmol/L 3OMG; 1 microCi/mL) was measured at 4C and pH 7.4. Three-OMG influx was terminated at 5-second intervals, washed cells were lysed, and uptake was quantitated by liquid scintillation counting. Patients' uptake (n = 22) was 44 +/- 8% of controls (100 +/- 22%, n = 70). Statistical analyses showed an uptake cut-off point at 60% uptake, a sensitivity of 86% (95%-confidence interval 78 to 94%), and a specificity of 97% (95%-confidence interval 93 to 100%). Gender, age, and ketosis did not influence 3OMG uptake. This assay provides a reproducible and accurate laboratory test for diagnosing the GTPS.
83 citations
TL;DR: A system that minimized nonspecific binding by the dye through the use of polymethyl vinyl ethers and bis‐(heptapropylene glycol) carbonate showed a greater chemical specificity for albumin when compared to most other proteins.
Abstract: We developed a dye-binding method for albumin in urine based on bis (3',3"-diiodo4'4"-dihydroxy-5'5"-dinitrophenyl)-3,4,5,6-tetrabr omosulfonphthalein (DIDNTB), a dye that has a higher chemical sensitivity and specificity for albumin when compared to two other commonly used dyes. We prepared urine dipsticks with DIDNTB and certain other compounds to prevent "nonspecific" binding to the dipstick matrix. The detection limit for albumin with DIDNTB as the dye is about 10 mg/L. The extent of dye binding to proteins and other compounds was studied using ultracentrifugation and a selectively permeable membrane that permitted the passage of free but not bound dye; we believe this method is superior to photometric titration. The affinity of the dyes for albumin was found to be pH dependent with stronger binding at pH 1.8 than at pH 7.0. At pH 1.8, DIDNTB had a ca.10-fold greater binding coefficient to albumin when compared to the widely used dyes, tetrabromophenol blue (CI 4430-25-5) or bromophenol blue (CI 115-39-9). We developed a system that minimized nonspecific binding by the dye through the use of polymethyl vinyl ethers and bis-(heptapropylene glycol) carbonate. DIDNTB showed a greater chemical specificity for albumin when compared to most other proteins. The new albumin dipsticks are resistant to many potential interferences at substantial concentrations, making the dipsticks suitable to screen for albuminuria.
54 citations
TL;DR: The method is not suitable for early detection of metastases but is a valuable tool for further investigating biological characteristics of circulating melanoma cells.
Abstract: We developed a cellular approach to the identification of circulating melanoma cells in peripheral blood using immunomagnetic cell sorting. One hundred seventy-eight blood samples from 129 melanoma patients and 30 samples from healthy persons and nonmelanoma patients were examined. After density gradient centrifugation the interphase was incubated with the mAb 9.2.27. Positive cells were labeled with magnetic microbeads and enriched by immunomagnetic cell sorting. Cells were stained using an alkaline phosphatase-antialkaline phosphatase assay and examined by light microscopy. In spiking experiments, melanoma cells seeded at a concentration of one melanoma cell per ml whole blood could be detected reliably with the assay. Circulating melanoma cells were not found in 30 controls examined, nor were 9.2.27-positive cells found in 41 patients with primary malignant melanoma. In patients with regional lymph node metastases and in patients with disseminated disease, circulating 9.2.27-positive cells could be detected in 3 out of 22 patients (13.6%) and 10 out of 66 patients (15.2%) examined. We present a sensitive and specific immunocytological approach to detect circulating melanoma cells in peripheral blood. The method is not suitable for early detection of metastases but is a valuable tool for further investigating biological characteristics of circulating melanoma cells.
51 citations
TL;DR: This meta‐analysis provides support for the reliability of the recently published methodology and reference data for the clinical interpretation of individual albumin, transferrin, and transthyretin values.
Abstract: Clinical interpretation of the acute-phase proteins--albumin, transferrin, and transthyretin--has been hampered by the lack of accurate and precise methods for quantifying the levels and a stable and respected reference material. Now that these issues have been addressed, the community is faced with the need for credible age- and gender-specific reference values. The number of publications that address this issue, even for an analyte as familiar as albumin, is small and, in most cases, such publications lack the relevant data that would allow a combined experience to be created. We have identified 40 studies that meet our criteria: a description of the study participants' health status, of the statistical methodology, and of the laboratory technique and/or reference material used. Few of these studies reported values stratified by gender. A summary of the published median levels by age is presented for the three analytes, along with our own age- and gender-specific medians based on a large cohort. Ten of the studies presented a 95 percent reference range, in close agreement with ours where selection was based upon reported diagnosis rather than upon determination of individual health status. This meta-analysis provides support for the reliability of our recently published methodology and reference data for the clinical interpretation of individual albumin, transferrin, and transthyretin values. As with most laboratory measurements, clinical interpretation requires that other laboratory and clinical factors be considered.
49 citations
TL;DR: This work investigated the performances of HbA1c determination by a latex enhanced turbidimetric immunoassay using the specific monoclonal antibodies (Unimate, Roche) against the β‐N‐terminal fragments.
Abstract: We investigated the performances of HbA1c determination by a latex enhanced turbidimetric immunoassay using the specific monoclonal antibodies (Unimate, Roche) against the beta-N-terminal fragments. The coefficients of variation ranges from 1.7 to 3.8% within assay (n = 30) and from 3.9 to 4.9% between assay (n = 20). The assay was linear from 2.5 to 14.9% of HbA1c. No interferences was found from fetal, carbamylated, or variant (S) hemoglobins and from labile Schiff adduct with glucose. The following relationship was derived from fresh sample comparison between HPLC (Diamat-BioRad) (x) and immunoassay (y) method: y = 0.971 x + 0.87%, r=0.98, n = 115. The immunoassay provides a highly precise and specific method for HbA1c.
43 citations
TL;DR: Results of this study showed that BTR is a good index of the hepatic parenchymal damage and that it may be a useful marker for monitoring response to nutritional therapy in patients with chronic liver disease.
Abstract: The branched-chain amino acid (BCAA)/tyrosine (Tyr) ratio (BTR) recently has been reported to be a good indicator of the severity of hepatic parenchymal injury in patients with chronic liver disease. In the present study, sequential changes of BTR after BCAA administration were determined in patients with chronic liver disease to evaluate the value of BTR as a marker of the clinical response to nutritional therapy in these patients. This study comprised 75 patients with chronic hepatitis and 96 with liver cirrhosis. BTR was significantly decreased in patients with cirrhosis and hepatitis compared with healthy subjects. BTR was significantly correlated with the Child-Pugh score and with other liver function tests. BCAA increased significantly 2 hr after BCAA administration and decreased gradually thereafter. Tyr significantly decreased 4 hr after BCAA administration. BTR significantly increased 2 and 4 hr after BCAA therapy. The increase in BTR 3 hr after BCAA administration was low in patients with decreased basal BTR. The results of this study showed that BTR is a good index of the hepatic parenchymal damage and that it may be a useful marker for monitoring response to nutritional therapy in patients with chronic liver disease.
38 citations
TL;DR: A procedure including sample collection, DNA purification, and PCR analysis of CTG repeat length without using 7‐deaza‐dGTP is described, which could be very useful in clinical and prenatal diagnosis as well as in prevalence study of DM.
Abstract: Myotonic dystrophy (DM) is caused by a CTG trinucleotide expansion mutation at exon 15 of the myotonic dystrophy protein kinase gene. The clinical severity of this disease correlates with the length of the CTG trinucleotide repeats. Determination of the CTG repeat length has been primarily relied on by Southern blot analysis of restriction enzyme-digested genomic DNA. The development of PCR-based Southern blotting methodology provides a much more sensitive and simpler protocol for DM diagnosis. However, the quality of the template and the high (G+C) ratio of the amplified region hamper the use of PCR on the diagnosis of DM. A modified PCR protocol to amplify different lengths of CTG repeat region using various concentrations of 7deaza-dGTP has been reported (1). Here we describe a procedure including sample collection, DNA purification, and PCR analysis of CTG repeat length without using 7-deaza-dGTP. This protocol is very sensitive and convenient because only a small number of nucleate cells are needed for detection of CTG expansion. Therefore, it could be very useful in clinical and prenatal diagnosis as well as in prevalence study of DM.
35 citations
TL;DR: In this article, the authors found that decreased p27 protein expression was associated with an increased likelihood of lymph node metastases in colon cancers, independent of the depth of tumor invasion.
Abstract: p27, a cyclin-dependent kinase inhibitor, suppresses proliferation of normal and neoplastic cells. Expression of p27 is correlated with survival in colon cancer. To some degree, right-sided colon cancers differ biologically and clinically from left-sided colon cancers. We analyzed 41 patients with right-sided colon cancers, including 18 cases with regional lymph node metastases and 23 cases with negative lymph nodes. Immunostaining for p27 was performed on histologic sections of primary cancers and scored. Correlation of p27 protein expression with histologic parameters was performed by t-test and multivariate analysis. Decreased p27 protein expression was associated with large tumor size. As percentages of positively stained tumor cells decreased from 70 to 29%, the mean tumor size increased from 1.9 to 7.3 cm. p27 protein expression significantly decreased in primary cancers with angiolymphatic invasion or with positive lymph nodes in comparison with those without angiolymphatic invasion (26 +/- 6 vs. 44 +/- 5%, P < 0.03) or with negative lymph nodes (23 +/- 4 vs. 47 +/- 6%, P < 0.003). p27 expression was not statistically different in terms of depth of tumor invasion (T1/T2 vs. T3/T4), tumor type or tumor differentiation. Multivariate analysis revealed that low p27 expression in primary cancers was correlated with lymph node metastases (P = 0.01). However, it did not correlate with any other histologic parameters. In summary, decreased p27 expression was associated with an increased likelihood of lymph node metastases in colon cancers, independent of depth of tumor invasion. This implies that p27 is a potentially important predictor for tumor metastasis and patient's prognosis in right-sided colon cancers.
TL;DR: These highly sensitive assays for estrone and 17 β‐estradiol are useful in measuring low levels of estrogen in postmenopausal women, and monitoring estrogen levels in women receiving CEE as hormone replacement therapy.
Abstract: We developed a highly sensitive assay for estrone and 17 β-estradiol in serum. Estrone and 17 β-estradiol, obtained by solid-phase extraction using a Sep pak tC18 cartridge, were purified by high-performance liquid chromatography (HPLC). Quantitation of estrone and 17 β-estradiol were carried out by radioimmunoassay. Not insignificantly, this automatic system of extraction and HPLC succeeded in analyzing 80 samples a week. Intra-assay coefficients of variation (CV) for estrone and 17 β-estradiol ranged from 19.5 to 28.7%, and from 8.5 to 13.7%, respectively. The minimum detectable dose for estrone and 17β-estradiol were 1.04 pg/ml and 0.64 pg/ml, respectively. The serum levels of 17 β-estradiol using our method strongly correlated with those by Gas chromatography mass spectrometry (GC-MS). The serum levels of estrone and 17 β-estradiol in 154 peri- and postmenopausal women were estimated to be between 15 and 27 pg/ml and between 3.5 and 24.0 pg/ml, respectively, while the serum level of 17 β-estradiol in postmenopausal women, in particular, was estimated to be from 3.5 to 6.3 pg/ml. For postmenopausal women who suffered from vasomotor symptoms, the mean levels of estrone and 17 β-estradiol at 12 to 18 hours after treatment with daily 0.625 mg conjugated equine estrogen (CEE) and 2.5 mg medroxyprogesterone acetate (MPA) were 135.0 and 21.3 pg/ml at 12 months, respectively. On the other hand, levels of estrone and 17 β-estradiol at 12 to 18 hours after treatment with CEE and MPA every other day, were 73.4 and 15.3 pg/ml, respectively. These highly sensitive assays for estrone and 17 β-estradiol are useful in measuring low levels of estrogen in postmenopausal women, and monitoring estrogen levels in women receiving CEE as hormone replacement therapy. J. Clin. Lab. Anal. 13:266–272, 1999. © 1999 Wiley-Liss, Inc.
TL;DR: Moderate or high aCL concentrations and their association with aβ2GPI seems to be useful for the assessment of the risk of venous thrombosis in unselected patients with SLE or APS.
Abstract: Antiphospholipid antibodies (aPL) react with negatively charged phospholipids, which may often be complexed with a protein cofactor such as β2 glycoprotein (β2GPI) and prothrombin. Cofactor requirements may be assessed by measuring antibodies to β2GPI or by adding Tween 20 to some reagents in the assays for aPL (anticardiolipin and antiphosphatidylserine). We have measured anticardiolipin antibodies (aCL), antiphosphatidylserine antibodies (aPS), and anti β2 glycoprotein antibodies (aβ2GPI) in the serum of 10 normal subjects, 20 patients with systemic autoimmune diseases (SAD) diagnosed as having systemic lupus erythematosus (SLE) or antiphospholipid syndrome (APS), and 12 patients with HIV infection. Adding Tween 20 to aPS, the assay couldn't differentiate protein cofactor dependent from independent antibodies, but this can be done by measuring aβ2GPI (P = 0.0008). There was a significant correlation between aCL and aβ2GPI in the control group and in the patients with SAD, but not in the HIV-positive (HIV+) patients. After excluding the HIV+ patients, the best Spearman correlation was obtained between aβ2GPI and aCL (0.64, P < 0.0005). In 3 out of 7 patients with positive aβ2GPI and in 5 out of 6 patients with moderate or high positive aCL of the group of SAD, there was a history of venous thrombosis. The presence of moderate or high values of aCL either alone or together with aβ2GPI was significantly associated with a history of venous thrombosis (P < 0.05). Moderate or high aCL concentrations and their association with aβ2GPI seems to be useful for the assessment of the risk of venous thrombosis in unselected patients with SLE or APS. J. Clin. Lab. Anal. 13:59–64, 1999. © 1999 Wiley-Liss, Inc.
TL;DR: Normal elevations in 3rd trimester serum Her2/neu p105 and CA 15‐3 assay values should be considered when monitoring a pregnant patient with malignant disease.
Abstract: We sought to determine the maternal serum levels of four tumor-associated antigens during the three trimesters of pregnancy in healthy women. CEA, CA 228, CA 15-3, and Her2/neu oncogene product p105 assay values were determined for 90 healthy pregnant women during the three trimesters of pregnancy at five participating evaluation sites. Results were compared to means and cut-off values determined for healthy nonpregnant women. Differences in assay values in the 1st and 3rd trimester were analyzed for statistical significance (Student's t-test). CEA, CA 228 and CA 15-3 assay values in general were found to be within the normal range. CA 15-3 and Her2/neu p105 serum assay values were above the cut-off (3.3% and 8.2%, respectively) and were significantly elevated in the 3rd trimester as compared to the 1st trimester of pregnancy (P < 0.05 and P < 0.001, respectively). CEA and CA 228 may be of potential value in monitoring pregnant women with malignant disease. Normal elevations in 3rd trimester serum Her2/neu p105 and CA 15-3 assay values should be considered when monitoring a pregnant patient with malignant disease.
TL;DR: It is concluded that diagnostically challenging cases can only be subtyped by combining the cytomorphology with EC, FCI, and subsequent cytogenetic results, particularly true in recognizing the hypogranular variant of AML,M3 (AML, M3m) and distinguishing it from other subtypes.
Abstract: This study reports findings from a retrospective, comprehensive review of 80 cases of adult AML in regard to cytomorphology, enzyme cytochemistry (EC), flow cytometric immunophenotyping (FCI), and chromosomal analysis. From this review, we conclude that diagnostically challenging cases can only be subtyped by combining the cytomorphology with EC, FCI, and subsequent cytogenetic results. This is particularly true in recognizing the hypogranular variant of AML,M3 (AML, M3m) and distinguishing it from other subtypes. Nonlineage expression of markers (CD1, CD2, CD4, CD5, CD7, and CD56) was nonspecific as to AML subtype. Of interest, CD2 coexpression in acute myelomonocytic leukemia with eosinophilia (M4-Eo) was exclusively associated with inversion of chromosome 16 (inv 16) and was not observed in the other M4-Eo's without inv16. We also recognized a previously undescribed M3m with CD56 coexpression, heightening awareness of this entity which needs to be distinguished from the unique subtype of CD56+ AML with otherwise similar immunophenotypic and morphologic characteristics. In addition, nonlineage expression of CD19 alone was exclusively associated with the cytogenetic finding of t (8;21) (q22; q22) and thus may represent a favorable prognostic indicator by FCI. J. Clin. Lab. Anal. 13:19–26, 1999. © 1999 Wiley-Liss, Inc.
TL;DR: A microparticle‐enhanced nephelometric immunoassay was developed for κ‐casein quantification in human milk and was applied to 862 samples milk, collected from 82 mothers, to investigate the changes in casein concentrations during the first twelve weeks of lactation.
Abstract: A microparticle-enhanced nephelometric immunoassay was developed for κ-casein quantification in human milk. Together with a previously reported β-casein comparable immunoassay, it was applied to 862 samples milk, collected from 82 mothers, to investigate the changes in casein concentrations in human milk during the first twelve weeks of lactation. κ-casein immunoassay is sensitive (detection limit in the reaction mixture, 0.02 mg/L) and can be performed in diluted milk, excluding any interference or sample pretreatment. It allowed the quantitation of κ-casein over a large range of concentrations (0.14–4.56 g/L) with accuracy and precision (coefficients of variation from 3 to 10%). β- and κ-casein concentrations and percentages among milk total proteins increase between colostrum (2.6 g/L, 14.3% and 1.2 g/L, 6.5%, respectively) and transitional milk (4.4 g/L, 33.2% and 1.3 g/L, 9.5%), decrease at different rates from the third to the eighth week, then remain stable at least up to the end of the third month of lactation (2.7 g/L, 25.3% and 0.9 g/L, 8.5%). The β-casein/κ-casein ratio is higher in colostrum (0.61) than in transitional and mature milk (0.30) and could be related to a better digestibility of colostrum casein micelles by the neonate during the first days of life. J. Clin. Lab. Anal. 13:213–218, 1999. © 1999 Wiley-Liss, Inc.
TL;DR: By amplifying four target‐sequences of HCMV simultaneously with minimum incubation time at each temperature, a quadriplex, highly sensitive PCR assay was performed and allowed the detection of variants and achieved maximal sensitivity and specificity which are essential for a diagnostic utilization.
Abstract: The development of a quadriplex PCR method with amplification of HCMV in a single-step procedure using primers taken from four different regions of the viral genome is described. Different concentrations of dNTPs and MgCl2 were assayed in order to optimize the constitution of the buffer for the multiplex PCR. The specificity of the PCR was tested with 100 ng, 10 ng, and 1 ng of genomic MRC-5 cell DNA infected with CMV in the presence of 10 microg of uninfected MRC-5 cell DNA. The sensitivity of the PCR was evaluated by the amplification of various amounts (100 ng, 10 ng, 1 ng, and 0.1 ng) of genomic MRC-5 cell DNA infected with CMV. The specificity and sensitivity assays were performed for each pair of primers and for the combined four primer pairs in the multiplex PCR. CMV was consistently detected from 10 ng of genomic MRC-5 cell DNA with each primer pair. When all four sets of primers were combined in a single reaction tube, the sensitivity of the assay was equivalent to 10 ng of genomic MRC-5 cell DNA, whereas amplification from 1 ng genomic MRC-5 cell DNA produced only a subset of the amplimers. By amplifying four target-sequences of HCMV simultaneously with minimum incubation time at each temperature, a quadriplex, highly sensitive PCR assay was performed. The use of four primer sets designed in different genomic regions of HCMV allowed the detection of variants and achieved maximal sensitivity and specificity which are essential for a diagnostic utilization.
TL;DR: The results indicate that Ava II and Hinc II polymorphisms at the LDLR locus contribute to the variability of total cholesterol and LDL‐C levels in HRG individuals, and suggest that the HDLR polymorphism remains a useful genetic marker for predicting CHD risk.
Abstract: Coronary heart disease (CHD) has presented high prevalence in the Brazilian population. Nevertheless, studies of genetic risk factors for CHD in our country are insufficiently carried out. We have investigated the effects of Ava II (exon 13) and Hinc II (exon 12) polymorphisms at the low-density lipoprotein receptor (LDLR) gene on circulating lipids of 170 white unrelated individuals presenting a lipid profile with high risk for CHD (HRG) and 130 controls (CG) from Sao Paulo City, Brazil. Ava II and Hinc II polymorphic regions at the LDLR gene were amplified by PCR and analyzed by enzymatic isotyping. The frequency of the genotypes A+A+ (Ava II) and H+H+ (Hinc II) was greater in HRG group compared to that of the controls (32 vs. 16% and 32 vs. 18%, respectively). Moreover, in the HRG group, A+A+ and H+H+ genotypes were associated with high concentrations of total cholesterol and LDL-C in serum (P = 0.0001). Our results indicate that Ava II and Hinc II polymorphisms at the LDLR locus contribute to the variability of total cholesterol and LDL-C levels in HRG individuals. These data suggest that the LDLR polymorphism remains a useful genetic marker for predicting CHD risk. J. Clin. Lab. Anal. 13:251–258, 1999. © 1999 Wiley-Liss, Inc.
TL;DR: FCM‐FNA was found to be particularly useful in the differential diagnosis of mantle‐cell and small‐lymphocytic lymphoma and in the identification of lymphoblastic lymphoma/leukemia.
Abstract: In order to determine the value of flow cytometric (FCM) immunophenotyping of fine-needle aspirates (FNA) in the diagnosis and classification of lymphoproliferative diseases, 61 tissue samples were studied and compared with the cytologic/histological results. In vivo and ex vivo FNA biopsy yielded the material for FCM, which comprised an extensive number of lymphoid cell markers. In all but three cases sufficient cells were collected. Overall, malignancy was diagnosed in 33 cases from a total of 47 (70.2%), and in the remaining cases malignancy was not detected. Eleven cases were correctly diagnosed as reactive processes (11/11). There were no false positive cases of malignancy, as diagnosed by FCM-FNA. The best accuracy was achieved in the low-grade B-cell lymphomas and lymphoblastic lymphoma/leukemia. We conclude that in a significant number of cases, FCM-FNA permits the separation between lymphoid malignancies and reactive processes without false positive results. It was found to be particularly useful in the differential diagnosis of mantle-cell and small-lymphocytic lymphoma and in the identification of lymphoblastic lymphoma/leukemia. J. Clin. Lab. Anal. 13:224–228, 1999. © 1999 Wiley-Liss, Inc.
TL;DR: The presence of two fractions of serum fluorine: diffusible and nondiffusible (or protein bound) is established and a technique for their clinical estimation is described.
Abstract: This article describes a technique for the measurement of total and diffusible F content of serum, at clinical significant concentrations of F (1–10 μM). The proposed procedure avoids the interference of unknown serum components with the ion-specific electrode. Sample F is concentrated fivefold through distillation of hydrofluoric acid (Taves' method). Ionic fluoride is presented to the electrode in a simple solution at concentrations within the linear response of the electrode. Average recoveries of F from serum or its ultrafiltrate were 96 ± 7% (21%) and 97 ± 12% (53%) (mean ± SEM [CV]), respectively. With four replicates of each sample, the technique produce within-run standard deviations of 0.6 μM and 2.2 μM at 1 and 10 μM F, respectively. Total precision assessment gave standard deviations of 0.6 μM and 2.6 μM at 1 and 10 μM F, respectively. The fasting serum F levels of normal climacteric women, 45 to 65 years, showed an asymmetric distribution. The data obtained started at the detection limit of the technique (0.1 mM). The 75 percentile was 1.85 μM for total and 0.5 μM for diffusible F. In patients (n = 25) treated with NaF (30 mg F/day) the fasting levels of total serum F (4.5 ± 1.7 μM) did not differ from those of diffusible F (4.2 ± 1.5 μM). In patients (n = 50) treated with sodium monofluorophosphate (15 mg F/day) the fasting levels of total and diffusible serum F were 6.5 ± 1.7 μM and 0.5 ± 0.03 μM, respectively.In conclusion, this paper establishes the presence of two fractions of serum fluorine: diffusible and nondiffusible (or protein bound) and describes a technique for their clinical estimation. In untreated subjects and in patients receiving NaF, the former fraction contains ionic fluoride. In patients treated with MFP, diffusible serum fluorine is composed by ionic fluoride and low molecular weight, peptide-bound, acid-labile fluorine. J. Clin. Lab. Anal. 13:151–157, 1999. © 1999 Wiley-Liss, Inc.
TL;DR: Chromogranin A, a marker for neuroendocrine cells, is associated with poor prognosis when detected by immunohistochemical technique in prostate tumors.
Abstract: Chromogranin A (CgA), a marker for neuroendocrine cells, is associated with poor prognosis when detected by immunohistochemical technique in prostate tumors. We have developed an ELISA on microplates for serum CgA and established the normal reference range. We also attempted to find out whether elevated serum CgA levels could be found in patients with various malignant diseases. Because of non-Gaussian distribution, both medians and 97.5 percentiles of serum CgA levels for men and women of four different age groups were determined. For women, the median and 97.5 percentiles are 20.7 and 63.9 ng/mL for ages 20 to 50, and 32 and 93.8 for 50 to 80 years of age, respectively; for men, they are 27.9 and 78.4 ng/mL for ages 18 to 40 and 41.6 and 92 for 40 to 80 years old, respectively. Elevated serum concentrations of CgA were detectable in patients with prostate cancer not undergoing hormonal treatment, and in patients with various malignant diseases including nonendocrine carcinomas. Most elevated serum CgA levels were associated with sera containing highly elevated serum tumor markers. Drugs targeting neuroendocrine cells should be administered for cancer patients with elevated serum CgA levels.
TL;DR: The authors conclude that, in view of its high sensitivity, the DIAMEDIX assay may be useful in screening for H. pylori infection and in identifying anti‐CagA antibodies.
Abstract: The authors compare efficacy of two ELISA assays (one supplied by DIAMEDIX [Delta Biological s.r.l.], and the other by RADIM [RADIM I]) in detecting total anti-H. pylori antibodies, and of two further ELISA methods (one supplied by EUROSPITAL [Helori CTX IgG] and the other by RADIM [RADIM 2]) in identifying anti-CagA antibodies, using sera from 69 controls (20 adults and 49 children) and from 96 patients, obtained before endoscopy. Seventy-three of the patients had H. pylori infection, while the remaining 23 were H. pylori negative (histology and polymerase chain reaction [PCR]). Fifty-two of the H. pylori positive patients, had cagA-positive strain infection, identified by PCR. The DIAMEDIX assay was found to be more sensitive (92%) than RADIM 1 (79%) in identifying H. pylori positive patients, irrespective of the infecting strain. On the other hand, the DIAMEDIX assay was less specific than RADIM 1 for H. pylori-negative patients (43% vs. 83%). However, when patients already treated for H. pylori infection were excluded from the group of H. pylori-negative patients, the DIAMEDIX assay had a specificity of 89%. In identifying anti-CagA antibodies, the kit supplied by RADIM (RADIM 2) had a sensitivity of 90% and a specificity of 94%, whereas that supplied by EUROSPITAL had a sensitivity of 100% and a specificity of 76%. The performances of the two methods in the identification of anti-CagA antibodies were found to be similar. The authors conclude that, in view of its high sensitivity, the DIAMEDIX assay may be useful in screening for H. pylori infection. J. Clin. Lab. Anal. 13:194–198, 1999. © 1999 Wiley-Liss, Inc.
TL;DR: The most consistent finding was the positive association between the cyst fluid K+/Na+ ratio and the free to bound PSA ratio, which was confirmed by Spearman correlation as well as by Wilcoxon and chi‐square analysis.
Abstract: We have analyzed matched serum and breast cyst fluid samples for total PSA from 148 patients with fibrocystic breast disease. We have also determined the molecular forms of PSA (free PSA and PSA bound to alpha1-antichymotrypsin) in 78 breast cyst fluid samples. We found that total PSA can be detected in all cyst fluids and in about 75% of female sera. The median total PSA concentration in breast cyst fluid (bcf) is about 30 times higher than the median in the corresponding sera. Breast cyst fluid and serum PSA are not correlated with each other. Total serum PSA is inversely associated with patient age but the inverse association between bcf PSA and age is weak. Lower total PSA in bcf was seen in women who breast feed, and higher bcf PSA is associated with multiple cysts. Type I cysts (with a high K+/ Na+ ratio) tend to have higher total PSA than Type II cysts. All but three of the fractionated cyst fluids (75/78; 96%) had free PSA as the predominant molecular form. The most consistent finding of our study was the positive association between the cyst fluid K+/Na+ ratio and the free to bound PSA ratio. This association was confirmed by Spearman correlation as well as by Wilcoxon and chi-square analysis. Secretory/apocrine cysts (Type I) tend to have more total PSA and proportionally more free PSA than transudative/flattened cysts (Type II).
TL;DR: Serum adenosine deaminase activities of patients with tuberculosis was compared with those of control groups with (+) and (–) PPD results and were found to be higher than the controls and may be used in adjunction with other methods in the follow‐up of tuberculosis with high sensitivity, specificity, and ease in applicability and specimen collection.
Abstract: Three methods in the diagnosis and treatment of tuberculosis have been compared in this study. Serum adenosine deaminase activities of patients with tuberculosis was compared with those of control groups with (+) and (–) PPD (purified protein derivative) results and were found to be higher than the controls. Within the controls the PPD (+) group displayed higher adenosine deaminase activities in comparison to the PPD (–) group. All patients had growth of B. Tuberculosis in the culture medium and all but one had positive polymerase chain reaction (PCR) results. Control patients were negative for culture and PCR. The sensitivity of ADA (adenosine deaminase) assay was 91.7% and specificity was 94.5%, whereas PCR had a sensitivity of 95.8% and a specificity of 100%. The ADA assay may be used in adjunction with other methods in the follow-up of tuberculosis with high sensitivity, specificity, and ease in applicability and specimen collection. J. Clin. Lab. Anal. 13:209–212, 1999. © 1999 Wiley-Liss, Inc.
TL;DR: Comparisons of the HCV screening results from 161 patients in long‐term maintenance haemodialysis as assessed by the recently developed Enzyme Linked Immunosorbant Assay III (ELISA III), confirmed by the Recombinant Immunoblot 3rd generation assay (RIBA 3rd) and determined by the qualitative RT‐PCR method suggest that ELISA III remains still a highly reliable and valuable assay.
Abstract: Hepatitis C virus (HCV) serotyping assays have evolved from simple antibody screening tests to complex RNA-based qualitative and quantitative methods. The objective of this study was to compare the HCV screening results from 161 patients in long-term maintenance haemodialysis (HD) as assessed by the recently developed Enzyme Linked Immunosorbant Assay III (ELISA III), confirmed by the Recombinant Immunoblot 3rd generation assay (RIBA 3rd) and determined by the qualitative HCV reverse transcription polymerase chain reaction (RT-PCR) method. One hundred sixty-one HD patients were tested for the presence of anti-HCV antibodies by the ELISA III and confirmed by the RIBA 3rd. HCV RNA was determined by an HCV RT-PCR method. All reported results that were designated as discrepant, anti-HCV (+) and/or HCV RNA (+) were further investigated by means of a quantitative HCV RT-PCR assay. Reported results obtained from ELISA III and qualitative RT-PCR assays were HCV positive for 16/161 patients (9,93%) and these were designated as anti-HCV (+)/HCV RNA (+). Subsequently, these 16 anti-HCV positive/161 HD patients were confirmed by the RIBA 3rd. Three individuals anti-HCV (–)/RIBA (+)/ HCV RNA (–)], the viral load that was reported from the quantitative RT-PCR was less than the assay detection level (< 2,000 viral copies/ml). In view of previous observations, our findings suggest that ELISA III remains still a highly reliable and valuable assay. However, despite the cost, the combination of both ELISA III and qualitative RT-PCR allows a definitive classification on HCV diagnosis. J. Clin. Lab. Anal. 13:122–125, 1999. © 1999 Wiley-Liss, Inc.
TL;DR: The lysozyme ratio showed similar clinical sensitivity and specificity as to adenosine deaminase, and the results showed a good serial precision.
Abstract: A microparticle-enhanced nephelometric immunoassay, based on polystyrene beads coated with antihuman lysozyme antibody, has been developed for lysozyme quantification in sera and pleural effusions. The standard curve extends from 0.58 mg/l to 18.75 mg/l and no antigen effect was observed. The results showed a good serial precision. The intra-assay precision (n = 20) expressed as CV was between 2.2 and 4.2 in three different concentrations. The inter-assay precision, with different calibration curves (n = 12) was between 6.4 and 7.1. The analytical assay showed a sufficient linearity (r > 0.999). There were no interferences either with haemoglobin (up to 4 g/l), lipids (up to 0.5%, expressed as 1% Lipofundina content), or bilirubin (up to 5 mg/dl). The analytical sensitivity was lower than 0.6 mg/l. The correlation with a Micrococcus lysodeikticus turbidimetric assay showed a correlation coefficient of 0.915. We have studied 92 patients with pleural effusion. In each case, pleural fluid adenosine deaminase activity and pleural fluid to plasma lysozyme ratio were determined. The lysozyme ratio showed similar clinical sensitivity and specificity as to adenosine deaminase.
TL;DR: The clinical laboratory will soon be able to provide powerful new molecular diagnostic tools along with multianalytic assays for expression of genes and proteins in different patterns of diseases, disease progression, and predisposition to diseases.
Abstract: Future trends in healthcare delivery will focus on preventive medicine that will require integration of molecular medicine with advanced information and computer technology. Molecular medicine will shift from costly intervention and treatment of established diseases to proactive prediction and prevention of disease risks. This approach will require new informatic systems that will link large scale databanks and special programs for data mining and retrieval in bioinformatics, cheminformatics, and population genetics. The clinical laboratory will soon be able to provide powerful new molecular diagnostic tools along with multianalytic assays for expression of genes and proteins in different patterns of diseases, disease progression, and predisposition to diseases.
TL;DR: It is concluded that both low‐avidity IgG and IgA tests are helpful and reliable for the diagnosis of recent primary infection by rubella virus.
Abstract: 2National Health Centers for Microbiology, Virology, and Immunology, Madrid, Spain The detection of IgA and low-avidity IgG and antibodies in serum is a potentially useful marker of recent infection by a microorganism. We studied the reliability of IgG avidity and presence of IgA for the diagnosis of recent acute infection by rubella virus. Low-avidity IgG (Avy-EIA test) was determined with a modified commercial test using 8 molar urea (indirect ELISA, DiaSorin, Italy) and IgA was determined with a homemade indirect ELISA test. Twenty-five patients with recent primary infection by rubella virus (group I) and 50 healthy subjects (group II) were studied. In group I low-avidity IgG varied between 100 and 0% (67.3 ± 21.8%); IgA was present in 24 patients (96%). In group II low-avidity IgG varied from 50.4 to 0% (19.8 ± 16.9%). IgA was present in 2 subjects (4%). The sensitivity of the Avi-EIA and the IgA test was 92 and 96%, respectively; specificity was 100 and 96%, respectively. We conclude that both low-avidity IgG and IgA tests are helpful and reliable for the diagnosis of recent primary infection. J. Clin. Lab. Anal. 13:1‐4, 1999. © 1999 Wiley-Liss, Inc.
TL;DR: The albumin strip gave a lower risk of false negatives than a protein strip based on tetrabromophenol blue (TBPB) dye and was more sensitive to disease condition and the protein strip was not sensitive to low levels of albumin and the agreement between TBPB dye strip and the quantitative analysis was not as affected by the albumin content.
Abstract: An albumin selective urine strip based on bis (3',3''-diiodo-4', 4''-dihydroxy-5',5''-dinitrophenyl)-3,4,5,6-tetrabromo sulfonphthalein dye (DIDNTB) dye was examined in populations with clinical proteinuria. The relationship of albumin to the sum concentration of all protein in urine was found to vary widely even though the albumin concentration generally increased with the total protein concentration. The albumin reagent strips correlated well with immuno-nephrometric assays for albumin on specimens from hypertensives, diabetics, and renal disease which tended to have albumin contents of >/= 50.0%. High proteinuria concentrations of > 250 mg/l, with low albumin contents of
TL;DR: In vitro findings, together with the in vivo data, suggest that free sialic acid might have an inhibitory effect on the activation of C3 and the following complement cascade, and might also have been responsible for the improvement of hypocomplementemia.
Abstract: The role of free sialic acid on complement activation was investigated. The serum levels of free sialic acid and total sialic acid were measured by previously described methods in 16 patients with acute post-infectious glomerulonephritis (AGN), 27 patients with systemic lupus erythematosus (SLE), 15 patients with persistent hypocomplementemic membranoproliferative glomerulonephritis (MPGN), and 13 healthy controls. A statistical study demonstrated an increased level of free sialic acid in patients with AGN and SLE in which the hypocomplementemia improved throughout the course and a decreased level of free sialic acid in patients with MPGN and SLE in which hypocomplementemia continued throughout the course. The levels of total sialic acid were significantly increased in patients with AGN and SLE and were significantly decreased in patients with MPGN. There was no correlation between the levels of free sialic acid and total sialic acid in patients with AGN, in whom the levels of both total and free sialic acids were increased. To examine the effect of free sialic acid on the complement cascade, lipopolysaccharide (LPS) was incubated with normal human serum (NHS) in the various concentrations of N-acetyl neuraminic acid (NANA), a member of the sialic acid group. The incubation mixtures were examined by enzyme immunoassay using monoclonal anti-iC3b antibody or anti-Bb antibody. Native C3 or Factor B in NHS broke down less following the addition of NANA. To elucidate the role of NANA on the hemolytic function of C3, a rabbit erythrocyte (Ra E) hemolytic assay was carried out. Ra E lysed completely in the presence of R3 with native C3. However, hemolysis occurred to a lesser degree in C3-depleted serum (R3) or R3 with NANA-treated C3. To investigate the influence of NANA on complement components, the levels of complement components were measured in the incubation mixture with various doses of NANA and NHS. The levels of C3 and C5 were significantly decreased after the addition of NANA, even though the levels of Factor H and Factor I were not markedly changed. These data indicate that NANA exerts an influence on the complement components even though it has no effect on the regulatory proteins of complement. Our in vitro findings, together with the in vivo data, suggest that free sialic acid might have an inhibitory effect on the activation of C3 and the following complement cascade, and might also have been responsible for the improvement of hypocomplementemia.