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Biomedical subjects

B Gustavsson

Publications and source records attributed to B Gustavsson.

At least 37 records · Page 2Linked to original sources
PubMed1998

Rapid quantitative PCR determination of relative gene expression in tumor specimens using high-pressure liquid chromatography.

A reverse transcriptase polymerase chain reaction (rt-PCR) for quantification of gene expression has been optimized for analysis of folylpolyglutamate synthase (FPGS) and thymidylate synthase (TS), using beta-actin as an internal standard (house-keeping gene). Total RNA was isolated from tumor tissue, reversely transcribed to cDNA and PCR amplified with primers specific for TS, FPGS and beta-actin in separate vials. PCR products were separated and quantified by high-pressure liquid chromatography (HPLC) without addition of radioactive or fluorescent markers, which minimizes labor and occupational hazards. The day-to-day variation in the HPLC analysis was 2.7% and the within sample variations for rt-PCR/HPLC analysis of TS and FPGS were 18.5% for both assays. This method provides a tool for convenient gene expression analysis in clinical biopsies.

Chromatography, High Pressure Liquid↗
PubMed1998

Open, randomized, multicenter trial of raltitrexed versus fluorouracil plus high-dose leucovorin in patients with advanced colorectal cancer. Tomudex Colorectal Cancer Study Group.

PURPOSE: To compare raltitrexed (Tomudex; Zeneca Pharmaceuticals Ltd, Macclesfield, United Kingdom) a direct, specific thymidylate synthase (TS) inhibitor with fluorouracil (5-FU) plus high-dose leucovorin (LV) as first-line treatment for advanced colorectal cancer (ACC). PATIENTS AND METHODS: A total of 495 patients were randomized to raltitrexed (3 mg/m2) once every 3 weeks or 5-FU (400 mg/m2) plus LV (200 mg/m2) daily for 5 days every 4 weeks. RESULTS: The randomized groups were well balanced demographically. With a minimum 17-month follow-up, median survival was comparable between groups (10.9 months raltitrexed v 12.3 months 5-FU/LV; hazards ratio, 1.15; 95% confidence interval [CI], 0.93 to 1.42; P=.197), although time to progression was statistically significantly shorter in the raltitrexed group. Overall objective responses were comparable (19% raltitrexed v 18% 5-FU/LV), with more than 50% of patients in each group having stable disease. Significantly less World Health Organization (WHO) grade 3 and 4 stomatitis (2% v 16%, P < .001) and a reduced incidence of leukopenia (6% v 13%) and diarrhea (10% v 19%) occurred in the raltitrexed group (particularly at cycle 1 ). This resulted in fewer dose reductions at cycle 2 (4% raltitrexed v 28% 5-FU/LV) and early quality-of-life (QoL) benefits for raltitrexed patients. Reversible, clinically insignificant increases in transaminases were reported in 13% of raltitrexed patients. Palliative benefits of weight gain, improved performance status, and reduced disease-related symptoms were evident in both groups. CONCLUSION: Raltitrexed is confirmed as an effective option in the first-line palliative management of ACC, with comparable efficacy to and tolerability advantages (in terms of reduced incidence of stomatitis, diarrhea, and leukopenia) over 5-FU/LV. Raltitrexed has the added convenience of an every 3 weeks dosing schedule.

Adenocarcinoma↗
PubMed1998

Chemical stability and human plasma pharmacokinetics of reduced folates.

The in vitro stability and plasma pharmacokinetics of 5,10-methylenetetrahydrofolic acid (CH2FH4), tetrahydrofolic acid (FH4), 5-methyltetrahydrofolic acid (CH3FH4), and 5-formyltetrahydrofolic acid (5-CHOFH4) were studied in view of their potential usefulness in cancer chemotherapy. Analysis of reduced folates was done on a high-performance liquid chromatography (HPLC) system. The high sensitivity of FH4 and CH2FH4 to oxidation can be circumvented by use of high concentrations of the folates, addition of ascorbate, and by thorough exclusion of atmospheric O2. Intravenous injection of 200 mg FH4 or CH2FH4 resulted in average peak concentrations of 69.2 +/- 3.2 nmol/ml and 46.3 +/- 2.6 nmol/ml, respectively. The plasma concentration curves support the concept that these highly oxygen-sensitive reduced folates can be reliably administered as pharmaceuticals to cancer patients through the use of a suitable air-occlusive system for their preparation and administration.

Colorectal Neoplasms↗
PubMed1997

Differential regulation of the plasminogen activator inhibitor-1 (PAI-1) gene expression by growth factors and progesterone in human endometrial stromal cells.

Plasminogen activator inhibitor-1 (PAI-1) has important regulatory functions in haemostasis, extracellular matrix turn-over and cell adhesion. We studied PAI-1 gene expression in primary cultures of endometrial stromal cells, and found that PAI-1 protein and mRNA were increased both by agents associated with differentiation, i.e. progesterone and transforming growth factor beta1 (TGFbeta1), and by those promoting proliferation, i.e. epidermal growth factor (EGF), TGFalpha and basic fibroblast growth factor (bFGF). In order to further elucidate the mechanism of regulation, we transfected stromal cells with an expression construct containing 804 bp of the PAI-1 promoter fused to a chloramphenicol acetyl transferase (CAT) reporter gene. After stimulation with the polypeptide growth factors TGFbeta1, EGF and bFGF we found increased CAT activity, indicating that these stimulators had initiated interaction with the transfected promoter fragment. On the other hand, stimulation with progesterone did not increase CAT activity, even though these cells were perfectly able to respond with increased secretion of PAI-1 protein. Run off experiments demonstrated that progesterone increased the stability of PAI-1 mRNA in endometrial stromal cells. We conclude that the polypeptide growth factors TGFbeta1, EGF and bFGF increase PAI-1 expression by increasing gene transcription. Progesterone, on the other hand, does not interact with the 804 bp promoter region, but increases the stability of PAI-1 mRNA.

Adult↗
PubMed1997

Detection of thymidylate synthase gene expression levels in formalin-fixed paraffin embedded tissue by semiquantitative, nonradioactive reverse transcriptase polymerase chain reaction.

We describe a new, simple and reliable semiautomated strategy for quantifying mRNA from archival specimens by using oligo(dT)25 paramagnetic beads and the reverse-transcriptase polymerase chain reaction (PCR) coupled with quantitative digital image analysis (Q-DIA). To evaluate the experimental conditions, we examined thymidylate synthase (TS) gene expression in mRNA isolated from both flash-frozen and formalin-fixed paraffin-embedded human biopsy samples using biopsy material obtained from 2 patients prior to chemotherapy with 5-fluorouracil. Following the electrophoretic separation of the PCR products through a 20% polyacrylamide gel, quantitation of the perimeters of the silver-nitrate-stained PCR products will be done by Q-DIA using a video frame-grabber board attached to a CCD camera using Image-Pro+ software. Validation of this approach will involve a comparison of the observed gene expression levels to TS protein levels obtained by tissue homogenization assays of TS, tetrahydrofolate, 5,10-methylenetetrahydrofolate, 2'-deoxyuridine-5'-monophosphate and 5-fluoro-2'-deoxyuridylate (FdUMP), by established [3H]FdUMP ligand-binding assays. The novelty of this method is that it offers a low-cost means whereby Q-DIA is performed directly from the gel to rapidly and accurately determine the level of TS gene expression, which is standardized against the beta-actin housekeeping gene. In the protocol described herein, gene expression studies can be done quickly and without the use of radioactive substances in both normal clinical samples shock frozen at the time of surgical excision and in formalin-fixed paraffin-embedded archival samples, which are commonly available in all hospital pathology departments. To demonstrate the utility of this method, mRNA was extracted from both nonpathological and tumor biopsies originating from both types of material from the same patients. TS gene expression in the flash-frozen and archival materials was compared to the level of TS intracellular enzyme activity in the same samples and a correlation of 89 and 80% between the shock-frozen and archival material relative to TS intracellular enzyme activity levels was observed. These findings suggest that routine semiautomated quantitative analysis of rare mRNA transcripts, e.g. TS, from archival material can be applied for retrospective studies.

DNA, Complementary↗
PubMed1997

Effects of intravesical instillation of 5-fluorouracil and interferon in patients with recurrent superficial urinary bladder carcinoma. A clinical and pharmacodynamic study.

Eleven patients with recurrent superficial bladder tumours were treated with 6 weekly instillations of 10 million IU Introna and 1000 mg 5-fluorouracil for 1 h. Before and immediately after the first treatment biopsies were taken from normal urothelium and tumour for analysis of thymidylate synthase (TS). One papillary tumour was left as a marker. Tumour tissue had 9 times higher TS concentrations than normal urothelium (0.97 versus 0.11 pmol/g, p < 0.005). Despite a large variation in TS concentration in the tumours between different patients (range 0.02-2.24 pmol/g), after instillation the TS concentration decreased significantly in all but one patient. Six patients had complete and 2 had partial tumour regression after treatment. The effect was inversely correlated to the initial TS value. A low TS value seemed to predict a good response. The data suggest that weekly administrations are not sufficient in those with high TS concentrations. New treatment schedules may be beneficial in those with highly proliferating bladder tumours.

Administration, Intravesical↗
PubMed1996

Decreased growth rate and tumour formation of human anaplastic thyroid carcinoma cells transfected with a human thyrotropin receptor cDNA in NMRI nude mice treated with propylthiouracil.

The effect of the human TSH-receptor (TSHR) on the growth of human anaplastic thyroid carcinoma cells lacking the endogenous expression of TSHR, was studied both in vitro and in vivo in NMRI nude mice. Cells from a human anaplastic thyroid carcinoma cell line (C643) were transfected with a TSHR cDNA, and clones were isolated after neomycin selection. The expression of a functional receptor protein was ensured by analysis of the specific binding of 125I-TSH and measurement of TSH-induced cAMP. Incorporation of [3H]thymidine and increase in cell number was slightly inhibited by TSH in TSHR-expressing cells in vitro. In order to investigate whether the regained expression of a functional TSHR protein in C643 cells could influence the in vivo growth, cells were injected subcutaneously into NMRI nude mice. To manipulate the endogenous level of TSH, animals were given 6n-propyl-2-thiouracil (PTU; resulting in a high TSH level), T4 (a low TSH level) or no treatment (as a control). There seemed to be a TSH induced inhibition of tumour growth, since tumours in mice treated with PTU grew after a longer take rate and with a slower growth rate. The present results suggest a TSH-mediated growth inhibition in the TSHR-transfected C 643 anaplastic thyroid carcinoma cells.

Animals↗
PubMed1996

The role of reactive oxygen metabolites in the transcriptional regulation of IFN-gamma gene expression by histamine in NK cells following IL-2 stimulation.

The secretion of interferon-gamma (IFN-gamma) by natural killer (NK) cells following in vitro stimulation with interleukin-2 (IL-2) is inhibited by co-incubation with autologous monocytes at a transcriptional level by more than sixty-fold. In this study, we investigate the nature of the inhibitory signal and particularly the role of reactive oxygen metabolites (ROMs). It was found that the inhibition of IFN-gamma was operating at a pre-translational level, this was indicated by the inability of CD 56(+)-enriched natural killer cells to accumulate IFN-gamma mRNA in the presence of elutriated monocytes. Both catalase, a scavenger of hydrogen peroxide and histamine, a biogenic amine which inhibits the generation of ROMs by monocytes, strongly abrogated the inhibition of IFN-gamma production. We thereby conclude that histamine behaves synergistically with IL-2 at a transcriptional level to induce IFN-gamma even in an admixture of NK cells and monocytes.

Base Sequence↗
PubMed1996

A phase II trial of 5-fluorouracil and 1-leucovorin in patients with metastatic colorectal cancer.

We undertook a multicenter phase II trial of 5-fluorouracil (5FU) + 1-leucovorin (1-LV) in previously untreated patients with metastatic colorectal cancer to determine the response rate, response duration, time to progression, survival, and toxicity. Patients were treated with i.v. 5FU 370 mg/m2/day and 1-LV 100 mg/m2/day x 5 every 28 days. Toxicity and response were determined by WHO criteria. One hundred and twenty-six patients were entered, and 119 patients were eligible and evaluable. Eighty-eight patients had colon cancer and 37 had rectal cancer. The male:female ratio was 58:68. The mean age was 62.2 years. ECOG performance status distribution was 0 (39.7%), 1 (46%), and 2 (11.9%). The median number of courses of therapy administered was 4.5. Severe- or life-threatening stomatitis or diarrhea, nausea, and granulocytopenia occurred in 17.6, 23.2, 17.6, and 15.9% of patients, respectively. The response rate was 22/119 [18.5%; 95% confidence interval (CI) of 12.0-26.6]. Median response duration was 188 days (95% CI of 111-248 days). Median survival was 379 days (95% confidence interval of 289-452 days). These results indicate that when 1-LV is combined with 5FU, toxicity is similar in pattern and severity to that of the d,1 racemic mixture. The overall efficacy of 1-LV + 5FU is comparable to a recent metaanalysis.

Adult↗
PubMed1996

Rapid detection of thymidylate synthase gene expression levels by semi-quantitative competitive reverse transcriptase polymerase chain reaction followed by quantitative digital image analysis.

We describe a simplified and reliable polymerase chain reaction (PCR) method to quantify thymidylate synthase (TS) gene expression levels from clinical human tumor biopsy samples as small as 100 mg using the beta-actin housekeeping gene as a reference standard. The semiquantitative RT-PCR is carried out by the coamplification of the target template and an external competitor using primer pairs common to both templates in the same reaction vessel. Quantitative digital image analysis is performed directly after electrophoresis, thus mRNA quantification is done quickly and without the use of radioactive substances. The observed relative TS gene expression levels varied between 3- and 40-fold, but most of the values were grouped within a 10-fold range. There is an observed 89% correlation between TS mRNA expression and protein levels. These findings suggest that preliminary experiments used to determine the linear range of RT-PCR amplification in non-competitive semiquantitative PCR experiments, and the use of radioactive substances to quantify PCR products may be unnecessary.

Base Sequence↗
PubMed1996

Sonification as a means of enhancing the detection of gene expression levels from formalin-fixed, paraffin-embedded biopsies.

We describe a novel approach for the isolation and quantification of mRNA from archival specimens by using oligo(dT)25 paramagnetic beads and the reverse transcription polymerase chain reaction (RT-PCR). A preliminary study is conducted to evaluate experimental conditions and the effects of varied periods of sonification on the yield of mRNA isolated from formalin-fixed, paraffin-embedded human biopsy samples. Validation of this approach will involve the comparison of observed beta-actin gene expression levels among different samples from the same patient after various periods of sonification. The novelty of this method is that it offers a means of analyzing archival samples using semiquantitative RT-PCR following sonification-enhanced mRNA extraction. The utility of this protocol allows for gene expression studies to be done effectively using the formalin-fixed, paraffin-embedded archival samples that are commonly available in all hospital pathology departments.

Actins↗
PubMed1996

Different intravenous administration techniques for 5-fluorouracil. Pharmacokinetics and pharmacodynamic effects.

The pharmacokinetics after 20 min intravenous infusion or a 2 min bolus (push) injection of 5-fluorouracil (500 mg/m2) were studied in 14 colorectal cancer patients. Treatment effects and toxicity related to the administration technique of 5-fluorouracil were retrospectively analysed in 198 colorectal cancer patients. The AUC after bolus injection was 6158 +/- 874 micromol/l*min compared to 3355 +/- 428 micromol/l*min after short-time infusion of 5-fluorouracil (p < 0.01). The mean peak-level after bolus injection was 341 +/- 34 microM versus 161 +/- 17 microM after a short-time infusion (p < 0.01). Patients receiving bolus injections had significantly better treatment result (32% partial remission) than patients receiving infusion (10% partial remissions, p < 0.001). Toxic side-effects were more frequently encountered after bolus injection but subjective improvement was also more frequently experienced by these patients. Bolus 5-fluorouracil push injection rather than a short-time infusion appears to be the more efficient administration technique.

Aged↗
PubMed1996

Thymidylate synthase in advanced gastrointestinal and breast cancers.

Knowledge of population thymidylate synthase (TS) levels in malignant tumors and normal tissues is essential for the use of TS as a predictor for 5-fluorouracil treatment. Tumor tissue TS levels in fresh frozen surgical biopsies from 136 patients with gastrointestinal or breast cancer, not previously subjected to chemotherapy, were analysed by [3H]FdUMP radioligand binding assay. TS levels were 2.4 +/- 0.31 pmol/g in liver metastases of colorectal cancer (n = 87), 4.2 +/- 1.0 pmol/g in primary colorectal cancer (n = 13), 2.7 +/- 0.93 pmol/g in gastric cancer (n = 13), 3.1 +/- 1.7 pmol/g in pancreatic cancer (n = 10), 3.4 +/- 1.4 pmol/g in breast cancer (n = 13) and 0.58 +/- 0.075 pmol/g in normal liver parenchyma (n = 24). TS levels were significantly higher in malignant tumor tissues compared to normal liver parenchyma.

Antimetabolites, Antineoplastic↗
PubMed1996

Fibrolamellar hepatic carcinoma in an area with a low incidence of primary liver cancer: a retrospective study.

OBJECTIVE: To assess the incidence and prognosis of fibrolamellar hepatic carcinoma in a defined population. DESIGN: Retrospective study of histological slides. SETTING: University hospital, Sweden. SUBJECTS: The 532 patients (out of a total of 711 who were treated at the university hospital during a 22 year period 1 January 1958-31 December 1979) whose primary hepatocellular carcinoma was confirmed on review of the histological slides. MAIN OUTCOME MEASURES: Incidence and prognosis of fibrolamellar hepatic carcinoma. RESULTS: Two patients (women aged 22 and 46) were found to have fibrolamellar tumours and in both they were advanced and the patients died 2 weeks and 9 months, respectively, after exploratory laparotomy. If these are taken as a proportion of the 18 patients who were under the age of 50 at the time of diagnosis then the incidence of the fibrolamellar type of hepatocellular carcinoma is 11%. Since then (in 1993) we have come across one further case, a woman of 39 who was well 22 months after operation though she had metastatic disease. CONCLUSIONS: The fibrolamellar type of hepatocellular carcinoma is rare, and all three of our cases were young women (under the age of 50). It seems to have a slightly better prognosis than other types of primary hepatic tumours.

Adolescent↗
PubMed1995

Antitumour effects of pure diastereoisomers of 5-formyltetrahydrofolate in hepatic transplants of a rodent colon carcinoma model.

The effects of the two diastereoisomers of 5-formyltetrahydrofolate on tumour growth, thymidylate synthase (TS, EC 2.1.1.45) levels, and potentiation of 5-fluorouracil cytotoxicity were studied in an in vivo rat colon carcinoma model, transplanted to liver. The animals were randomized into eight groups, treated with daily i.v. tail vein injections of racemic (d,l)-5-formyltetrahydrofolate (5-CHO-FH4), 15 mg/kg, (1)-5-CHO-FH4 7.5 mg/kg, and (d)-5-CHO-FH4 7.5 mg/kg, 5-fluorouracil (FUra) 30 mg/kg, (d,l)-5-CHO-FH4 15 mg/kg+FUra 30 mg/kg, (l) 5-CHO-FH4 7.5 mg/kg+FUra 30 mg/kg, and (d)-5-CHO-FH4 7.5 mg/kg+FUra 30 mg/kg, and a sham-treated control group. The average tumour size of the groups was equal at the start of treatment. After six days' treatment the average tumour sizes were at laparotomy 3.3 +/- 1.0 g in the (d/l)-5-CHO-FH4 treated group, compared to 2.0 +/- 0.1 g in the FUra treated group and 7.1 +/- 3.1 g in the controls. Natural (l)-5-CHO-FH4 promoted tumour growth (average tumour weight 10.8 +/- 4.0 g), whereas the unnatural (d)-5-CHO-FH4 alone retarded it (average tumour weight 1.2 +/- 0.40 g). (l)-5-CHO-FH4 induced a significant increase in tumour tissue TS levels by [3H]FdUMP radioligand assay (27.5 +/- 8.4 pmol/g tumour tissue) compared to controls (16.8 +/- 6.1 pmol/g tumour tissue). Increases in 5,10-methylenetetrahydrofolate and tetrahydrofolate occurred with FUra alone, with a further statistically significant increase in both folates with the addition of (d)-5-CHO-FH4 to FUra.

Animals↗
PubMed1995

Functional analysis of a variant of the thyrotropin receptor gene in a family with Graves' disease.

Nucleotide sequence analysis of PCR fragments corresponding to the TSH-receptor (TSHR) amplified from genomic DNA collected from the four members of a family, two of which had Graves' thyrotoxicosis, revealed a nucleotide substitution in the first position of codon 36 of the TSH-receptor gene in the two patients. The nucleotide substitution was from G to C, leading to a 36D-->36H change (D36H) in the predicted amino acid sequence of the receptor. The altered sequence was also found in DNA obtained from their mother, but not in DNA from their father. We stably expressed the two receptor variants in NIH 3T3 cells, by transfection of cDNA encoding the wildtype (WT) and D36H variants of the TSHR. Neither the binding of 125I-TSH nor the responsiveness to TSH measured as cAMP formation, appeared to be different in the TSHR-D36H compared to the TSHR-WT. Furthermore, the D36H-receptor also became desensitized when exposed to TSH as did the WT-receptor.

3T3 Cells↗