[Gene therapy against aging: possible or not?].
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Aging↗
Biomedical subjects
M Christiansen
Publications and source records attributed to M Christiansen.
[Maternal serum screening for Down syndrome].
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Denmark↗
Hepatic gluconeogenic fluxes and glycogen turnover during fasting in humans. A stable isotope study.
Fluxes through intrahepatic glucose-producing metabolic pathways were measured in normal humans during overnight or prolonged (60 h) fasting. The glucuronate probe was used to measure the turnover and sources of hepatic UDP-glucose; mass isotopomer distribution analysis from [2-13C1]glycerol for gluconeogenesis and UDP-gluconeogenesis; [U-13C6]glucose for glucose production (GP) and the direct UDP-glucose pathway; and [1-2H1]galactose for UDP-glucose flux and retention in hepatic glycogen. After overnight fasting, GP (fluxes in milligram per kilogram per minute) was 2.19+/-0.09, of which 0.79 (36%) was from gluconeogenesis, 1.40 was from glycogenolysis, 0.30 was retained in glycogen via UDP-gluconeogenesis, and 0.17 entered hepatic UDP-glucose by the direct pathway. Thus, total flux through the gluconeogenic pathway (1.09) represented 54% of extrahepatic glucose disposal (2.02) and the net hepatic glycogen depletion rate was 0.93 (46%). Prolonging [2-13C1]glycerol infusion slowly increased measured fractional gluconeogenesis. In response to prolonged fasting, GP was lower (1. 43+/-0.06) and fractional and absolute gluconeogenesis were higher (78+/-2% and 1.11+/-0.07, respectively). The small but nonzero glycogen input to plasma glucose (0.32+/-0.03) was completely balanced by retained UDP-gluconeogenesis (0.31+/-0.02). Total gluconeogenic pathway flux therefore accounted for 99+/-2% of GP, but with a glycogen cycle interposed. Prolonging isotope infusion to 10 h increased measured fractional gluconeogenesis and UDP-gluconeogenesis to 84-96%, implying replacement of glycogen by gluconeogenic-labeled glucose. Moreover, after glucagon administration, GP (1.65), recovery of [1-2H1]galactose label in plasma glucose (25%) and fractional gluconeogenesis (91%) increased, such that 78% (0.45/0.59) of glycogen released was labeled (i.e., of recent gluconeogenic origin). In conclusion, hepatic gluconeogenic flux into glycogen and glycogen turnover persist during fasting in humans, reconciling inconsistencies in the literature and interposing another locus of control in the normal pathway of GP.
Carbon Isotopes↗
Dual-label time-resolved immunofluorometric assay for simultaneous determination of pregnancy-associated plasma protein A and free beta-subunit of human chorionic gonadotrophin.
Using time-resolved fluorometry, a simple one-step dual-label immunometric assay has been developed, which allows simultaneous determination of pregnancy-associated plasma protein A (PAPP-A) and free beta-subunit of human chorionic gonadotrophin (beta-hCG) in first-trimester maternal serum samples. Two monoclonal antibodies were biotinylated and immobilized onto the surface of streptavidin-coated microtitration plates, and used to capture PAPP-A and beta-hCG. respectively. Europium (Eu) and Samarium (Sm) chelates were conjugated to two additional monoclonal antibodies acting as detection antibodies for PAPP-A and beta-hCG. The assay was performed using a 4-h one-step format. The within-run precision with buffer-based calibrators was below 8% over the working range of PAPP-A (40-10000 mIU/l) and beta-hCG (7.3-525 micrograms/l) and no hook effect was observed. The intra- and inter-assay coefficients of variation were below 7.1% for serum samples. PAPP-A and beta-hCG concentrations measured by the dual assay in 39 first-trimester serum samples correlated excellently with those obtained by DELFIA single-label PAPP-A (r = 0.997) and the beta-hCG part (r = 0.993) of the DELFIA AFP/beta hCG dual-label assay.
Antibodies, Monoclonal↗
Monoclonal antibodies against human tetranectin, epitope characterization and use in immunohistochemistry.
Two IgG2a/kappa- and three IgG1/kappa monoclonal antibodies (MAbs) were produced against human tetranectin (TN): this is the first report of stable hybridomas producing MAbs against TN. All the MAbs reacted with non-conformational epitopes located within amino acid residues 50-181 of the primary sequence. In relative epitope mapping with enzyme immunoassay and isotachophoresis the five MAbs defined two independent epitope groups. One of them is suggested to be immunodominant in rabbits, since MAbs inhibited binding of a polyclonal rabbit antibody. Several combinations of MAbs were suitable for TN-ELISA and two MAbs could be used for immunohistochemical detection of TN in both fresh frozen and paraffin-embedded tissues. The MAbs will facilitate future studies on structure, function, clinical significance and immunolocalization of TN.
Animals↗
Schwangerschaftsprotein 1 (SP1) as a maternal serum marker for Down syndrome in the first and second trimesters.
The potential of the maternal serum concentration of schwangerschaftsprotein 1 (MSSP1) as a marker for Down syndrome (DS) pregnancies was evaluated in the fifth to the 20th gestational week using 156 DS pregnancies and 546 unaffected control pregnancies. In DS pregnancies, the median of the multiple of the median (MOM) of MSSP1 was 0.27 [95 per cent confidence interval (CI) 0.11-0.59] in weeks 5-9 (n = 25) and 1.28 (CI 1.11-1.49) in weeks 14-20 (n = 117), significantly different from controls (P < 10(-6). In weeks 10-12, the median MSSP1 MOM was 0.89 (CI 0.20-2.09) (n = 14), not different from controls (P = 0.42). Using MSSP1 alone as a marker for DS gave--in empirical receiver-operator-characteristics (ROC) analysis--a detection rate of about 44 percent for a false-positive rate of about 5 per cent in weeks 5-9 (using MSSP1 MOM < or = cut-off), whereas a sensitivity of about 20 percent was found for a false-positive rate of 5 percent in weeks 14-20 (using MSSP1 MOM > or = cut-off). In parameterized ROC analysis, the detection rates were 38 and 18 percent for a false-positive rate of 5 per cent in weeks 5-9 and 14-20, respectively.
Down Syndrome↗
Double-monoclonal immunofluorometric assays for pregnancy-associated plasma protein A/proeosinophil major basic protein (PAPP-A/proMBP) complex in first-trimester maternal serum screening for Down syndrome.
Four double-monoclonal time-resolved immunofluorometric assays (TrIFMAs) have been developed for the specific determination of pregnancy-associated plasma protein A/proeosinophil major basic protein (PAPP-A/ proMBP) complex in first-trimester maternal serum samples. The assays have a functional sensitivity of < 4 mIU/L and a working range from 4 to 1000 mIU/L. These 4 assays, together with a polyclonal sandwich TrIFMA, were compared for their ability to discriminate between normal pregnancies (n = 149) and pregnancies carrying a Down syndrome fetus (n = 36) in maternal serum screening samples from gestational weeks 4-13. In 26 Down syndrome pregnancies from gestational weeks 7-12, the median PAPP-A multiples of the median concentration in controls (MoMs) determined by monoclonal antibody combinations 234-3/234-2*, 234-4/234-2*, 234-4/234-5*, and 234-5/234-6* were 0.35, 0.37, 0.42, and 0.44, respectively, whereas the median MoM determined by the polyclonal assay was 0.56. ROC curve analysis also showed that better overall diagnostic accuracy and detection rates were achieved by the monoclonal TrIFMAs than by the polyclonal TrIFMA. This report is the first to describe assays that specifically measure PAPP-A/proMBP complex without possible interference from other proMBP-containing complexes.
Antibodies, Monoclonal↗
[Prenatal screening for Down's syndrome].
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Biomarkers↗
Time-resolved immunofluorometric assay of pregnancy-associated plasma protein A in maternal serum screening for Down's syndrome in first trimester of pregnancy.
A low maternal serum concentration of pregnancy associated plasma protein-A (MS-PAPP-A) in the first trimester has been suggested as a marker for the presence of a Down's syndrome (DS) fetus. We developed a time-resolved immunofluorometric assay (TrIFMA) for PAPP-A with a sensitivity < 3.9 mIU/l. In the 7-12 gestational weeks interval the median multiples of the median (MoM) was 0.57 (95%-confidence interval; 0.47-0.99) in DS pregnancies (n = 29) and lower than in controls (n = 223) (P < 0.005). The efficiency of MS-PAPP-A alone was evaluated using empirical receiver-operator-characteristics (ROC) and a sensitivity of about 25% was found for a false-positive rate of about 10% in the 7-12 gestational weeks interval. In parameterized ROC analysis a sensitivity of 9% was found for a false-positive rate of 5%. The TrIFMA PAPP-A assay seems to fulfil the quality criteria for an assay to be used in large-scale serum screening for Down's syndrome.
Down Syndrome↗
Quantitative detection of male DNA by polymerase chain reaction using a single primer set: application to sex determination and counting of rare fetal cells.
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DNA↗
[Plasma calprotectin. A new prognostic marker of survival in alcoholic liver cirrhosis].
The purpose of this study was to determine plasma concentrations of calprotectin in patients with different severity of alcoholic cirrhosis. Additionally, the prognostic value of calprotectin for recurrent infections and for survival was investigated after a median observation period of 19 months. No difference was found in calprotectin levels when comparing healthy controls (n = 16), compensated (n = 50) and decompensated cirrhotics (n = 34). However, high calprotectin concentrations (> median) was a significant prognostic marker of poor survival (p = 0.001, Log-rank test). Calprotectin levels (> median) showed an independent and much higher prognostic value than variables of liver disease (multivariate Cox model). During follow-up calprotectin levels (> median) were also a predictor of recurrent infection (p = 0.009, Log-rank test). Thus, in patients with alcoholic cirrhosis, plasma calprotectin appears to be a new prognostic marker of survival, which seems independent of severity of liver disease. Furthermore, high plasma calprotectin levels may characterize a group of cirrhotics with recurring bacterial infections.
Adult↗
Qualitative assessment of intrathecal IgG synthesis by isoelectric focusing and immunodetection: interlaboratory reproducibility and interobserver agreement.
Detection of intrathecal IgG synthesis is important in patients with suspected multiple sclerosis (MS). The recommended method for the detection of intrathecal synthesis of IgG is isoelectric focusing and immunodetection of oligoclonal bands. Recently "The Committee for European Concerted Action for Multiple Sclerosis" has recommended that the results of isoelectric focusing for the detection of intrathecal synthesis of oligoclonal bands should not only be stated as positive or negative for intrathecal synthesis; instead, the laboratory should provide a detailed description of the IgG pattern in both cerebrospinal fluid (CSF) and serum together with a conclusion concerning the presence of intrathecal synthesis. We studied the interlaboratory reproducibility and interobserver agreement of isoelectric focusing, and the recommended classification system for the assessment of intrathecal IgG synthesis, in two separate patient groups employing kappa statistics. We found a high degree of interlaboratory reproducibility (133 patients; kappa = 0.95 +/- 0.05) and interobserver agreement (356 patients; kappa = 0.97 +/- 0.04) when the presence or absence of intrathecal IgG synthesis was assessed. The agreement was less pronounced, although still fully satisfactory, when the results were classified according to the detailed system by two laboratories (133 patients; kappa = 0.86 +/- 0.08) and two observers (356 patients; kappa = 0.88 +/- 0.08). Two specific problems in the interpretation of isoelectric focusing patterns were identified: one related to the discrimination of a pattern with several closely spaced bands which may represent a monoclonal protein; the other related to determining whether systemic band synthesis was present. We conclude that isoelectric focusing and immunodetection is a very reproducible technique for the detection of intrathecal IgG synthesis. Well defined criteria and extensive standardization may, however, be necessary when more elaborate classification systems are employed.
Humans↗
Alpha-fetoprotein and the acute phase response. A study using acute pelvic inflammatory disease as a model system.
Alpha-fetoprotein (AFP) is used as a tumor marker for hepatomas and germ cell tumors. In healthy non-pregnant adults the serum concentration (S-AFP) is very low and we examined whether it was affected when the acute phase response was activated, using patients with acute pelvic inflammatory disease (PID) as a model system. In 70 PID patients the median S-AFP was 1.2 kIU/l (range: 0.5-5.9 kIU/l), within the normal range. S-AFP did not correlate with the clinical grade of disease nor with the serum concentrations of acute phase reactants and albumin. Thus, S-AFP is not significantly affected by activation of the acute phase response and presence of infection should not per se interfere with the use of S-AFP as a tumor marker. However, a negative correlation was found with the serum concentration of alpha-2-macroglobulin (P = 0.05), but whether this has any biological significance remains to be clarified.
Acute-Phase Proteins↗
Plasma tetranectin and colorectal cancer.
The prognostic significance of plasma tetranectin (PL-TN) in colorectal cancer was retrospectively examined in 504 patients (80 Dukes' A, 174 Dukes' B, 98 Dukes' C and 152 Dukes' D). Follow-up time was 7-12 years. No significant prognostic variable was found for Dukes' A patients by Cox multivariate analysis. In stage B, PL-TN was the second strongest prognostic variable [relative hazard (RH) = 3.3 for patients with PL-TN < or = 7.5 mg/l]. The other prognostic variables were perineural invasion (RH = 3.7), tumour distance < or = 10 cm from the anal verge (RH = 3.0), postoperative radiotherapy (RH = 2.9) and a high carcinoembryonic antigen (CEA) score (RH = 1.8). In Dukes' C, only CEA score and gender were of prognostic significance. For Dukes' D, PL-TN was the only prognostic variable (RH = 1.7). Testing all patients in one multivariate analysis, Dukes' staging was the strongest and PL-TN the second strongest prognostic variable. The shortened survival for patients with low PL-TN levels is illustrated with lifetables.
Aged↗
Serum tetranectin in patients with acute pelvic inflammatory disease (PID). Correlation to clinical and laboratory findings.
AIM OF STUDY: To clarify the impact of the presence of pelvic inflammatory disease (PID) and activation of the acute phase response on the serum level of tetranectin (Se-TN), a potential new tumor marker for ovarian cancer. MATERIALS AND METHODS: The study group consisted of 70 patients with a laparoscopically verified PID and 47 healthy female controls. RESULTS: Lower Se-TN levels were found for the PID group compared to the control group (p < 0.0001). It was not possible to relate the decreases in Se-TN levels to any distinct bacterial strain. Neither was it possible to find any correlation between Se-TN and severity of PID (p = 0.5). A significant positive correlation was found between Se-TN and ALB (p < 0.001). A just significant negative correlation was found between Se-TN and C-reactive protein (CRP) (p = 0.04), while no correlation was found with any of the other acute phase reactants. Highly significant correlations were found between all the acute phase reactants and grade of PID. CONCLUSIONS: A slight, but significant reduction in Se-TN was found in PID patients. The decrease was minor compared to the reported findings of very low Se-TN levels for ovarian cancer patients. However, the finding is important in the assessment of TN used as a potential screening marker for ovarian cancer, or as a diagnostic tool for pelvic tumors. Furthermore, Se-TN does not seem to behave as a negative acute phase reactant.
Acute-Phase Proteins↗
Plasma calprotectin: a new prognostic marker of survival in alcohol-induced cirrhosis.
Plasma levels of calprotectin were determined in 84 patients with alcohol-induced cirrhosis. Calprotectin is released from disintegrating neutrophils, and plasma levels seem to reflect activation and turnover of such cells. The purpose of the study was to investigate the degree of activation of neutrophils, which has been indicated to be increased and a cause of neutrophil exhaustion in these patients. Additionally, on follow-up after a median observation period of 559 days, we investigated the prognostic value of calprotectin for survival. No difference was found in calprotectin levels when comparing healthy controls with patients with compensated cirrhosis and those with decompensated cirrhosis. However, high calprotectin concentrations (> median) were a significant prognostic marker of poor survival (P = .001, log-rank test). Using a multivariate Cox proportional hazard model, the prognostic value of calprotectin seemed independent of severity of liver disease evaluated on eight clinical and biochemical variables of liver disease. Divided into groups by the median calprotectin concentration, analysis of survival was performed in the whole series of patients (n = 84) as well as in patients who were completely without signs of recent or actual infection (n = 54). In both groups, calprotectin levels (> median) showed a much higher prognostic value than albumin, prothrombin complex, bilirubin, and ascites. During follow-up, calprotectin levels (> median) were also a predictor of recurrent infection (P = .009). Thus, in patients with alcoholic cirrhosis, plasma calprotectin seems to be a new prognostic marker of survival, which seems independent of the severity of liver disease.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Sex hormone binding globulin phenotypes: their detection and distribution in healthy adults and in different clinical conditions.
Human sex hormone binding globulin (SHBG) is encoded by a normal and a variant allele. The resulting SHBG phenotypes (the homozygous normal SHBG, the heterozygous SHBG and the homozygous variant SHBG phenotype) can be distinguished by their electrophoretic patterns. We developed a novel detection system allowing us to distinguish between the different electrophoretic patterns in small amounts of plasma or serum (10 microliters). Small aliquots of Blue Sepharose were added to diluted sera or plasma samples for removal of albumin and the supernatants were subsequently applied to Western blotting. This method of detection was used to determine the distribution of SHBG phenotypes in healthy controls of both sexes and in five different pathological conditions characterized by changes in the SHBG level or endocrine disturbances (malignant and benign ovarian neoplasms, hirsutism, liver cirrhosis and alcoholism). The distribution of SHBG phenotypes was independent of such conditions and in agreement with the expected phenotype distribution of a bi-allelic gene in both healthy controls and patients (Hardy Weinberg law). An allele frequency of 0.13 was found for the SHBG variant allele based on the experimental values. Differences in SHBG phenotypes do not appear to have any clinical significance and no sex difference was found in the SHBG phenotype distribution.
Adolescent↗
Serum alpha-fetoprotein and alcohol consumption.
Fifty-nine persons, 23 chronic alcoholics and 36 normal healthy persons with a well described alcohol consumption, had the serum concentration of alpha-fetoprotein determined by a sensitive monoclonal immunofluorescent assay. A significant elevation in S-AFP was found in alcoholics, median 4.1 kIU/l as compared to 3.0 kIU/l in near-abstainers (< 12 g ethanol per day) (p < 0.02). This difference was not explained by differences in age. S-AFP correlated positively with age (p = 0.01). In non-alcoholics a borderline significant correlation with S-AFP was found with average daily alcohol consumption (self-reported) (p = 0.09) and a significant correlation with the serum concentration of carbohydrate-deficient transferrin (S-CDT) (p = 0.004). In 11 alcoholics 2 months of abstention from alcohol was accompanied by a median reduction of 21% in S-AFP (p < 10(-5)). In alcoholics, but not in social drinkers, S-AFP correlated with S-ASAT (p = 0.004). The increase of S-AFP with alcohol consumption may reflect reversible alcohol-induced liver affection.
Adult↗