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Ebba Nexo

Publications and source records attributed to Ebba Nexo.

At least 19 recordsLinked to original sources
PubMed2007

Inhibition of the epidermal growth factor receptor in bladder cancer cells treated with the DNA-damaging drug etoposide markedly increases apoptosis.

OBJECTIVE: To investigate the effect of the epidermal growth factor receptor (EGFR) on the induction of apoptosis by the chemotherapeutic agent etoposide (VP16), and to examine the effect of combining VP16 with gefitinib to see if the cell-survival mechanism can be prevented. MATERIALS AND METHODS: The bladder cancer cell lines RT4 and T24, representing low- and high-malignancy grades respectively, were treated with VP16 (10 or 50 microM) and the level of apoptosis determined using a commercial kit. EGFR receptor activity was determined by western blotting using antibodies against phosphorylated EGFR. The EGFR was either activated by heparin-binding (HB)-EGF (1 nM) or inhibited with the specific EGFR inhibitor gefitinib (1 or 5 microM). The pan-caspase inhibitor Z-VAD (30 microM) was used to test the involvement of caspase activity. RESULTS: Treatment of T24 bladder cancer cells with VP16 (50 microM) for 48 h induced phosphorylation of the EGFR and activation of the EGFR prevented the apoptosis induced by VP16. Thus, treatment of T24 cells with 50 microM VP16 for 48 h resulted in 19% apoptosis. However, activation of the EGFR with HB-EGF (1 nM) with VP16 (50 microM) significantly reduced the level of apoptosis by 25% (P < 0.05) showing that activating the EGFR has a cell-survival function. Inhibiting the EGFR with gefitinib (5 microM) blocked the VP16-induced activation of the EGFR. Combined treatment with gefitinib and VP16 resulted in 45% apoptotic cells, i.e. more than double the percentage of apoptotic cells with VP16 alone. This was found in both T24 and RT4 cells. Gefitinib used alone (1 and 5 microM) generated no apoptosis in the cells. Treatment of T24 cells with Z-VAD showed that apoptosis induced by both VP16 alone and VP16 with gefitinib was caspase-mediated. CONCLUSION: These results suggest that activation of the EGFR induced a cell-survival function when bladder cancer cells were treated with the DNA-damaging drug VP16, and that combined treatment with VP16 and the EGFR inhibitor gefitinib might improve the efficacy of treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2006

Diagnosis and treatment of vitamin B12 deficiency--an update.

We represent an update on diagnosing and treatment of vitamin B12 deficiency. Vitamin B12 deficiency should be suspected in all patients with unexplained anaemia and/or neurological symptoms,as well as in patients at risk of developing vitamin B12 deficiency such as the elderly and patients with intestinal diseases. Measurement of plasma cobalamins is suggested as the primary analysis followed by measurement of plasma methylmalonic acid in unsettled cases. Accumulating evidence indicates that the biologically active cobalamin,plasma holotranscobalamin (holoTC),may be superior to plasma cobalamins, and measurement of holoTC is currently introduced in the clinical setting. No consensus exists concerning evaluation of the cause for vitamin B12 deficiency,and pros and cons on the different tests mainly aiming at evaluation of the function of the gastric mucosa are presented. Once the diagnosis of vitamin B12 deficiency has been confirmed efficient treatment can be ensured either by injections every 2-3 month or by a daily dose of 1 mg vitamin B12.

Humans↗
PubMed2006

The chemotherapeutic agent VP16 increases the stability of HB-EGF mRNA by a mechanism involving the 3'-UTR.

VP16 is a chemotherapeutic agent that introduces DNA damage. We demonstrate that cellular stress induced by VP16 in the human cervix cancer cell line HeLa increases the HB-EGF (heparin binding epidermal growth factor like growth factor) mRNA level dose dependently. Maximal induction (10-fold) was observed at 20-40 microM VP16. Increased HB-EGF peptide levels accompanied the increase in HB-EGF mRNA. We investigated the molecular mechanism involved in HB-EGF mRNA induction by VP16. Transcription was only slightly increased (60%) as determined by real-time PCR quantification of transcription from a reporter plasmid containing the HB-EGF promoter in front of the luciferase gene. In contrast, HB-EGF mRNA stability was increased significantly by VP16 as demonstrated by monitoring HB-EGF mRNA decay in cells treated with the transcriptional inhibitor actinomycin D. The 3'-UTR (3'-untranslated region) of HB-EGF was inserted at the 3'-end of LacZ mRNA. VP16 treatment of the cells caused a 5-fold increase in this chimeric mRNA, as compared to LacZ without this 3'-UTR. A 186 nucleotide region of HB-EGF contains five of the six AUUUA sequences found in the 1454 nucleotide 3'-UTR of HB-EGF and we demonstrate that this region caused an approximately 3-fold induction of LacZ mRNA when inserted at the 3'-end, as compared to LacZ without any insertion at the 3'-end, demonstrating that a significant proportion of the effect resides in this region. Induction of HB-EGF by VP16 has important implications as HB-EGF has been reported to prevent cell death, which might lower the efficacy of chemotherapy. We demonstrate that mRNA stability and in particular the HB-EGF 3'-UTR is involved in the HB-EGF mRNA induction.

3' Untranslated Regions↗
PubMed2006

Plasma holotranscobalamin compared with plasma cobalamins for assessment of vitamin B12 absorption; optimisation of a non-radioactive vitamin B12 absorption test (CobaSorb).

BACKGROUND: A recently developed non-radioactive vitamin B(12) absorption test (CobaSorb) was further explored to identify the best marker for reflection of vitamin B(12) absorption and to determine the duration of the test. METHODS: Seventy-eight healthy individuals (age 21-81 years) were given three oral doses of 9 microg vitamin B(12) per day for 5 successive days. Non-fasting blood samples were collected on days 1 to 5 before administration of vitamin B(12) and on day 8. Cobalamins and holotranscobalamin were measured. RESULTS: Performance of the vitamin B(12) absorption test was evaluated in individuals with holotranscobalamin or cobalamins below the 75% percentiles. We used a change greater than 2xCV(day-to-day) in holotranscobalamin (22%) and cobalamins (12%) to indicate a change caused by absorption of vitamin B(12). Among individuals with a baseline holotranscobalamin below the 75% percentile (<75 pmol/L, n=57), 98% had an increase in holotranscobalamin >22% from day 1 to day 3. In contrast, only 72% of the individuals with baseline cobalamins below the 75% percentile (<335 pmol/L, n=57) had an increase in cobalamins >12%. CONCLUSIONS: In healthy individuals with baseline holotranscobalamin <75 pmol/L, vitamin B(12) absorption is well reflected by an increase in holotranscobalamin after 2 days administration of oral vitamin B(12).

Adult↗
PubMed2006

Increased TGF-alpha and EGF Receptor mRNA expression in response to neonatal unilateral partial ureter obstruction in rats.

AIM: To evaluate the potential role of members of the epidermal growth factor (EGF) family in altered renal growth caused by partial ureteral obstruction in the developing obstructed and non-obstructed kidneys. METHODS: During anesthesia either the upper fourth (n = 6-7) or the upper two-thirds of the left ureter (n = 6-7) were embedded into the psoas muscle in newborn rats resulting in mild or severe partial unilateral obstruction, respectively, which was maintained during the following 24 weeks. Sham-operated control rats were prepared in parallel (n = 6-7). Real time PCR assays were used to quantify mRNA encoding EGF, TGF-alpha, HB-EGF and EGF receptor. The expression of ribosomal RNA was determined to relate the specific mRNA expression of members of the EGF system. RESULTS: Relative expression of TGF-alpha and EGF receptor mRNA levels were elevated significantly both in the severe and mild obstructed kidney compared with the contralateral or sham-operated kidneys after 24 weeks of obstruction. However, the expression of neither EGF nor HB-EGF was changed after obstruction. CONCLUSION: The increased expression of TGF-alpha and its receptor in the obstructed kidney might be related to a cell-survival function in the affected cells possibly by protecting them from entering apoptosis.

Animals↗
PubMed2006

Clinical relevance of low serum vitamin B12 concentrations in older people: the Banbury B12 study.

BACKGROUND: low vitamin B12 concentrations are common in older people, but the clinical relevance of biochemical evidence of vitamin B12 deficiency in the absence of anaemia is uncertain. OBJECTIVE: to examine associations of cognitive impairment, depression and neuropathy with blood measurements of vitamin B12 and folate status in older people. DESIGN: cross-sectional study in general practice in Banbury, England. PARTICIPANTS: a total of 1,000 individuals aged 75 years or older living in the community. RESULTS: low vitamin B12 concentrations were identified in 13% of older people and were associated with memory impairment and depression. After adjustment for age, sex and smoking, individuals with vitamin B12 or holotranscobalamin (holoTC) in the bottom compared with top quartiles had a 2-fold risk (OR = 2.17; 95% CI 1.11-4.27) and a 3-fold risk (OR = 3.02; 95% CI 1.31-6.98) of cognitive impairment, respectively. Low vitamin B12 status was also associated with missing ankle tendon jerks but not with depression. Treatment with vitamin B12 for 3 months corrected the biochemical abnormalities but had no effect on any of the clinical measurements. CONCLUSIONS: low vitamin B12 concentrations are associated with cognitive impairment and missing ankle tendon jerks in older people in the absence of anaemia. Large-scale trials of vitamin B12 supplementation are required to assess the clinical significance of these associations.

Aged↗
PubMed2006

The effect of recombinant human intrinsic factor on the uptake of vitamin B12 in patients with evident vitamin B12 deficiency.

We report on the use of recombinant human intrinsic factor (rhIF) in a new vitamin B12 absorption test. Holotranscobalamin (holoTC) was measured before and 24 hours after intake of three 9-mg doses of vitamin B12 (B12) and again 24 hours after intake of the same dose of B12 together with rhIF (rhIF-B12). Nine patients with evident vitamin B12 deficiency had a significantly higher increase in holoTC after intake of rhIF-B12 than after intake of B12. Twenty-eight patients with suspected vitamin B12 deficiency showed no additional increase in holoTC after intake of rhIF-B12. We conclude that rhIF promotes B12 absorption among patients with evident vitamin B12 deficiency.

Biological Transport↗
PubMed2006

Circulating tyrosinase and MART-1 mRNA does not independently predict relapse or survival in patients with AJCC stage I-II melanoma.

The detection of melanoma cells in peripheral blood has been proposed to select patients with a high risk of relapse. In this study, tyrosinase and melanoma antigen recognized by T cells 1 (MART-1) mRNA expression was evaluated in serial samples obtained before definitive surgery and during follow-up in patients with American Joint Committee on Cancer stage I-II melanoma. Serial samples (n=2,262) were collected from 236 patients from 1997 to 2002. Analyses of the RNA samples were performed with a calibrated reverse transcriptase-PCR assay. Gender, age, primary tumor site, ulceration, thickness, Clark level, and histological subtype were analyzed together with tyrosinase and MART-1 mRNA treated as updated covariates in a Cox proportional-hazard model. After a median follow-up time of 66 months, 42 out of 236 patients (18%) had relapsed. The following variables were significantly associated with relapse-free survival in the univariate analyses: tyrosinase, MART-1, gender, ulceration, thickness, Clark level, and histological subtype. Entering these covariates into a multivariate Cox analysis resulted in thickness as the single independent prognostic factor (P<0.0001), whereas MART-1 (P=0.07) approached significance at the 5% significance level. The serial measurements of tyrosinase and MART-1 mRNA in peripheral blood of stage I-II melanoma patients cannot be demonstrated to have independent prognostic impact on relapse-free survival.

Adult↗
PubMed2006

Insulin-induced proliferation of bladder cancer cells is mediated through activation of the epidermal growth factor system.

The mechanism behind the growth-promoting effect of insulin is a subject of debate. Employing RT4 bladder cancer cells, we examined the cross-talk between insulin and the epidermal growth factor system. We found that insulin induced a time- and dose-dependent (25-1000 nmol.L(-1) insulin) increase in mRNA expression of three ligands from the epidermal growth factor system. Times for peak increase and fold increase after incubation with 250 nmol.L(-1) insulin were as follows: heparin-binding epidermal growth factor-like growth factor, 0.5 h, 1.4-fold, P < 0.05; epiregulin, 3 h, 14-fold, P < 0.0001; and amphiregulin, 3 h, 12-fold, P < 0.001. Induction of heparin-binding epidermal growth factor-like growth factor and amphiregulin was verified at the protein level. We demonstrate that incubation of RT4 bladder cancer cells for 24 h with 250 nmol.L(-1) insulin increases proliferation by 43% (P < 0.0001) as compared to untreated cells. At the same time, phosphorylation and thereby activation of the epidermal growth factor receptor (HER1) was observed. Both phosphorylation and insulin-induced proliferation were almost completely inhibited by the HER1 inhibitor Iressa (P < 0.0001). This shows that insulin leads to activation of HER1, and that HER1 plays an essential role in mediating the growth-promoting effect of insulin. Iressa inhibited not only the activation of HER1 caused by insulin but also the insulin-induced increase in the three ligands (heparin-binding epidermal growth factor-like growth factor, epiregulin and amphiregulin). As heparin-binding epidermal growth factor-like growth factor was induced before epiregulin and amphiregulin upon insulin stimulation, we speculated that the insulin-induced heparin-binding epidermal growth factor-like growth factor initiated the activation of HER1, and that this in turn led to increased expression of epiregulin and amphiregulin and thereby to continued activation of HER1. Earlier reports have shown that insulin-like growth factor receptor can activate HER1 via its ligand heparin-binding epidermal growth factor-like growth factor. In accord with this, we found that treatment of RT4 cells with recombinant heparin-binding epidermal growth factor-like growth factor mimicked the effect of insulin, with induction of mRNA for the three ligands. However, the insulin-induced increase in mRNA expression of amphiregulin and epiregulin could not be prevented by the heparin-binding epidermal growth factor-like growth factor inhibitor CRM197, demonstrating that heparin-binding epidermal growth factor-like growth factor is not essential for the insulin-induced increase in the expression of these ligands. In conclusion, we show that insulin-induced growth in RT4 cells requires activated HER1. Furthermore, activation of HER1 is required for the insulin-induced increase in expression of the HER1 ligands heparin-binding epidermal growth factor-like growth factor, amphiregulin and epiregulin.

Cell Proliferation↗
PubMed2005

The cobalamin-binding proteins transcobalamin and haptocorrin in maternal and cord blood sera at birth.

BACKGROUND: Two proteins carry vitamin B12 in plasma. Transcobalamin (TC) carries approximately 25% of total plasma vitamin B12 and is 6% to 20% saturated with cobalamin. Haptocorrin (HC) binds approximately 80% of total cobalamin and is largely saturated with cobalamin. METHODS: We investigated the distribution and the relationship between concentrations of cobalamin, total and holo forms of TC, and HC in blood samples from pregnant women just before delivery (n = 92) and in cord blood samples from their newborn babies. We also investigated the relationship between these proteins and concentrations of methylmalonic acid (MMA), the functional marker of vitamin B12 status. RESULTS: Concentrations of total serum cobalamin, total HC, holoHC, and percentage of HC saturation were higher in cord blood than in the maternal blood (mean cobalamin, 268 vs 188 pmol/L; total HC, 648 vs 538 pmol/L; holoHC, 441 vs 237 pmol/L; HC saturation, 70% vs 47%). Moreover, total TC was low in cord blood, whereas both holoTC and TC saturation were higher in cord blood than in the maternal blood (mean total TC, 654 vs 1002 pmol/L; holoTC, 118 vs 53 pmol/L; TC saturation, 19.8% vs 5.4%). Higher maternal serum cobalamin was associated with higher cord blood holoTC and TC saturation (P <0.05). Gestational age was also a significant determinant of baby total TC, TC saturation, total HC, and holoHC. CONCLUSION: The close correlation between the amounts of holoTC present in cord blood and in maternal serum supports the importance of maternal cobalamin status for ensuring a sufficient supply to the baby.

Adult↗
PubMed2005

Holotranscobalamin and total transcobalamin in human plasma: determination, determinants, and reference values in healthy adults.

BACKGROUND: We developed microbiological assays (MBAs) to identify determinants and to establish reference values for cobalamin bound to transcobalamin [holotranscobalamin (holoTC)] and total TC in plasma. METHODS: We captured holoTC with magnetic beads with TC antibodies and used a conventional MBA for cobalamin measurements. Total TC was determined as holoTC after TC was saturated with cyanocobalamin. The new assays were compared with published methods. Determinants and reference values were determined in 500 blood donors, ages 18-69 years. RESULTS: Determination of cobalamin, holoTC, and TC by MBA required <150 microL. HoloTC and TC by MBA correlated with holoTC by RIA (r = 0.95) and TC by ELISA (r = 0.79), respectively. Between-day CVs for holoTC and total TC were 4%-9%. Women had lower holoTC than men, but only at age < or = 45 years. In multivariate regression analyses, holoTC was positively associated with age (in women only), creatinine (in men only), and plasma concentrations of total TC, folate, and cysteine, but inversely correlated with homocysteine and methylmalonic acid. For all study participants, total TC was associated with holoTC and number of TCN2 766C alleles; in female participants only, total TC was also associated with age, homocysteine, and cysteine. Reference values were 670-1270 pmol/L for TC and 42-157 pmol/L for holoTC, but they differed according to age and sex. CONCLUSIONS: Our MBAs for TC and holoTC required low plasma volume and performed acceptably compared with other methods. Determinants of holoTC and TC differed between men and women and according to age. Separate reference intervals for holoTC should be considered in younger women.

Adolescent↗
PubMed2005

Nonradioactive vitamin B12 absorption test evaluated in controls and in patients with inherited malabsorption of vitamin B12.

BACKGROUND: Current tests for evaluation of vitamin B(12) absorption are problematic because they involve the use of radioactively labeled vitamin B(12). We describe a vitamin B(12) absorption test that circumvents this problem. METHODS: We measured cobalamin or transcobalamin saturated with cobalamin (holo-TC) 24 h after three 9-microg doses of vitamin B(12) given orally at 6-h intervals. We studied 17 patients with inherited malabsorption of vitamin B(12) attributable to Imerslund-Grasbeck syndrome (n = 13) or intrinsic factor deficiency (n = 4), their obligate heterozygous biological parents (n = 19), and healthy controls (n = 44). RESULTS: In the patients, the median (range) change of holo-TC after the B(12) load was not significant [1 (-42 to 5) pmol/L], nor was the change of cobalamin [-3 (-32 to 22) pmol/L], consistent with a lack of measurable active or passive absorption. In controls, however, the median (range) increases of holo-TC and cobalamin were 26 (-6 to 63) pmol/L and 41 (-37 to 109) pmol/L, respectively. Similarly, the parents showed increases of 23 (-2 to 47) pmol/L and 27 (-15 to 94) pmol/L. The mean areas under the ROC curves (95% confidence intervals) were 0.97 (0.93-1.0) for holo-TC and 0.87 (0.79-0.94) for cobalamin, distinguishing patients from controls. At a cutoff of 6 pmol/L for holo-TC, the diagnostic sensitivity (95% confidence interval) was 100 (81-100)%, and the diagnostic specificity was 92 (82-97)%. CONCLUSION: Measurement of holo-TC after administration of vitamin B(12) is a promising approach for evaluating vitamin B(12) absorption.

Absorption↗
PubMed2005

Glycosylation independent measurement of the cobalamin binding protein haptocorrin.

BACKGROUND: Haptocorrin carries the major part of the circulating vitamin B12. The protein is heavily glycosylated and this may have implications for its measurement. METHODS: We used two different ELISA assays. In one assay, we employed antibodies against native HC and no pre-treatment of samples or calibrators. In the other assay, we used antibodies raised against deglycosylated HC, and deglycosylated the samples and calibrators by treatment with neuraminidase and PNGase prior to analysis. Plasma samples from healthy donors were analysed. RESULTS: The ELISA against native HC showed a high detection limit (71 pmol/l) and a poor linearity for serial dilutions of samples. The ELISA against deglycosylated HC showed a detection limit of 1.6 pmol/l, an excellent linearity between 1.6 and 100 pmol/l (r(2) = 0.99) and an inaccuracy of 5% for concentrations ranging from 250 to 840 pmol/l. The 95% reference interval was 240-680 pmol/l (n = 148). The concentration of HC showed a strong association to plasma cobalamins (p < 0.0001). CONCLUSIONS: An ELISA against native HC does not ensure an equimolar measurement of HC, while this is the case when a glycosylation independent assay is employed. Using this assay, a very strong correlation between total plasma HC and cobalamins in healthy donors is obtained.

Cross Reactions↗
PubMed2005

Pathologic assessment of melanoma sentinel nodes: a role for molecular analysis using quantitative real-time reverse transcription-PCR for MART-1 and tyrosinase messenger RNA.

PURPOSE: Molecular analysis of melanoma sentinel nodes (SN) is sensitive, but poorly specific because metastases cannot be distinguished from benign nevus inclusions (BNI). We investigated whether quantitative reverse transcription-PCR (RT-PCR) detection of MART-1 and tyrosinase mRNAs could improve this specificity and contribute to SN assessment. EXPERIMENTAL DESIGN: Two hundred twenty SNs from 95 melanoma patients analyzed by extensive immunohistopathology and real-time quantitative RT-PCR. RESULTS: Using histopathology, SNs and patients were allotted to three diagnostic groups: (a) metastasis positive, (b) BNI positive, and (c) melanocyte-free. Median MART-1 and tyrosinase mRNA levels in SNs were significantly different in patients with metastasis compared with patients with BNIs (P < 0.05) and patients without melanocytic lesions (P < 0.001). However, a "gray-zone" was observed where distinction, based on mRNA levels, could not be made between the three groups. For both genes, the highest mRNA level recorded in each RT-PCR-positive patient was positively correlated with Breslow's tumor thickness. For SNs with metastases, tumor burden was significantly correlated to the mRNA level. Using the presence of a MART-1 RT-PCR signal to detect patients with metastases, a sensitivity of 100% and a negative predictive value of 100% were achieved when extensive immunohistology was used as reference. CONCLUSIONS: Quantitative RT-PCR MART-1 and tyrosinase mRNA analysis cannot be used alone for SN diagnosis because of its poor specificity for melanoma metastasis. However, in approximately one third of cases without RT-PCR evidence of MART-1 expression, extensive histopathologic SN investigation is not necessary, thus substantially reducing the cost of SN analysis. The level of melanocyte-associated mRNA is associated with both tumor thickness and tumor burden as measured histopathologically, suggesting that this may be of prognostic value.

Adult↗
PubMed2005

Down-regulation of S100C is associated with bladder cancer progression and poor survival.

PURPOSE: The goal of this study was to identify proteins down-regulated during bladder cancer progression. EXPERIMENTAL DESIGN: By using comparative proteome analysis and measurement of mRNA, we found a significant down-regulation of S100C, a member of the S100 family of proteins, in T24 (grade 3) as compared with RT4 (grade 1) bladder cancer cell lines. Moreover, quantification of the mRNA level revealed that decreased expression of the protein reflects a low level of transcription of the S100C gene. Based on this observation, we quantified the S100C mRNA expression level with real-time PCR in bladder cancer biopsy samples obtained from 88 patients followed for a median of 23 months (range, 1-97 months). RESULTS: We found a significantly lower mRNA expression of S100C in connective tissue invasive tumors (T1, P = 0.0030) and muscle invasive tumors [(T2-T4), P < 0.0001] compared with superficial tumors (Ta). A negative correlation between S100C and histopathologic grade (P = 0.0003) was also observed. Furthermore, the papillary type showed higher expression of S100C than did the solid type of the tumor (P < 0.0001). Importantly, we found that loss of S100C was associated with survival in bladder cancer patients (P = 0.0006). CONCLUSIONS: Our results show that low expression of S100C is associated with poor survival in patients with bladder cancer. Furthermore, loss of S100C in T1 as compared with Ta stage tumors emphasize that S100C expression is suppressed early during bladder cancer development.

Aged↗
PubMed2005

Tyrosinase messenger RNA in peripheral blood is related to poor survival in patients with metastatic melanoma following interleukin-2-based immunotherapy.

This study was conducted to examine the prognostic impact of four biomarkers [tyrosinase and MART-1 messenger RNA (mRNA), S100beta protein and lactate dehydrogenase (LDH)] in patients with metastatic melanoma, together with established clinical factors. Tyrosinase and MART-1 mRNA were measured by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). S100beta was measured using a commercially available immunoassay, and LDH was analysed conventionally. All markers were measured in blood samples before interleukin-2-based immunotherapy in 85 patients with metastatic melanoma. LDH, S100beta, tyrosinase, number of metastatic sites, location of metastatic sites and performance status were all significant factors for survival in univariate analyses. In multivariate analysis, tyrosinase [hazard ratio (HR)=1.6; 95% confidence interval (CI), 1.1-2.6; P=0.04] and LDH (HR=2.0; 95% CI, 1.1-3.5; P=0.02) were both independent prognostic factors for survival. A combination variable of tyrosinase and LDH remained independently associated with survival (P=0.04) after adjusting for the American Joint Committee on Cancer (AJCC) stage IV classification in a multivariate analysis involving both models. It can be concluded that tyrosinase mRNA and elevated LDH are independent prognostic factors for poor survival in this group of 85 patients. Additional studies are needed before the prognostic value of tyrosinase mRNA in metastatic melanoma can be firmly established. Further evaluation of the combined measurement of tyrosinase mRNA and LDH is warranted.

Adult↗
PubMed2005

Autoantibodies against intrinsic factor (IF) measured with an ELISA using recombinant human IF as both catching and detecting reagent.

The aim was to develop and validate an assay for measuring autoantibodies against human intrinsic factor (IF). For this purpose 1.25 pmol of recombinant IF was coupled to each well. Samples (100 microL of plasma diluted 1:1) were incubated for 1 h, followed by 30 min with the detection reagent (biotinylated IF, 3.3 pmol/mL). Samples were obtained from healthy blood donors (n = 141) and patients with suspected vitamin B(12) deficiency (n = 355). The initial assay results (n = 99 samples) were in reasonable agreement with those obtained using a commercial assay (Diagnostic Products Corporation). All donors but one showed a negative result. For the patient populations the fraction of positive results decreased with increasing levels of serum vitamin B 12 : 0.67 for <100 pmol/L (n = 13), 0.17 for 100-150 pmol/L (n = 23), 0.06 for 151-200 pmol/L (n = 65) and <0.01 for >200 pmol/L (n = 254). The imprecision was 11% as judged by repeat analyses. All samples remained positive when the catching reagent was exchanged with vitamin B 12 -saturated IF, suggesting that the samples contained both blocking (type I) and non-blocking (type II)antibodies. Results obtained with IF as the detection reagent correlated to those obtained when anti-immunoglobulin G was used instead. In conclusion, an ELISA using recombinant IF as both catching and detection reagent seems suitable for the detection of IF autoantibodies in plasma.

Adult↗