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Biomedical subjects

R Heikkilä

Publications and source records attributed to R Heikkilä.

At least 19 recordsLinked to original sources

Tumour microvessel density as predictor of chemotherapy response in breast cancer patients.

The aim of this study was to evaluate the predictive value of intratumoural microvessel density in breast cancer. We studied immunohistochemically primary tumours of 104 patients with metastasised breast cancer who took part in a randomised multicentre trial comparing docetaxel to sequential methotrexate and 5-fluorouracil. Vessels were highlighted with factor VIII staining and counted microscopically. Microvessel density was compared with clinical response to chemotherapy and patient survival. The microvessel density of the primary tumour was not significantly associated with patient's response to chemotherapy, time to progression or overall survival in the whole patient population or in the docetaxel or methotrexate and 5-fluorouracil groups. However, disease-free survival was longer in patients with low microvessel density (P=0.01). These findings suggest that microvessel density of the primary tumour cannot be used as a predictive marker for chemotherapy response in advanced breast cancer.

Antineoplastic Combined Chemotherapy Protocols↗

Fluorescence-based method for measuring and determining the mechanisms of recombination in quantitative PCR.

We quantitatively measured the amount of recombinant molecules formed during PCR when the break point cluster region (BCR) cDNA was coamplified with a homologous internal standard using Taq polymerase. The products were analysed under denaturing conditions using capillary electrophoresis followed by detection of the fluorescently labelled products and the recombinant molecules were differentiated by their size. Early termination of chain synthesis and reannealing of incomplete fragments, to each other as well as to BCR and internal standard, is one mechanism for generating recombinants during PCR since prolonging extension time reduced, but did not totally suppress recombinant molecule formation. Template switching by the extending chain is another mechanism since recombinant molecules could be detected even after only one round of primer extension. The latter mechanism is probably facilitated by increasing number of templates. Thus, the large increase of recombinant molecules formed in plateau phase is mediated by direct amplification of the recombinants and de novo synthesis by template switching. The effect of additives on recombination could be quantitatively measured and both betaine and DMSO were effective in suppressing recombination. Thus, prolonging extension time, reducing the number of amplification cycles and incorporating additives in the PCR reaction, reduced recombinant molecule formation.

Base Sequence↗

Quantitative analysis of cytokeratin 20 gene expression using RT-PCR and capillary electrophoresis with fluorescent DNA detection.

OBJECTIVE: We developed a quantitative reverse-transcription polymerase chain reaction (RT-PCR) to determine CK20 expression in colorectal tumor and hematopoietic tissue. DESIGN AND METHODS: Our method incorporates a calibrated PCR with an internal competitor and an external standard. RESULTS: The RT-PCR assay is sensitive detecting 10 target molecules of CK20 in solution with one round of 38 amplification cycles. Genomic DNA contamination was eliminated by Dnase I digestion of total RNA. The inclusion of a calibrator in the quantitative RT-PCR analysis allowed for a high throughput of unknown samples within the same assay improving comparative analysis between the samples tested. Analysis of peripheral blood and bone marrow from 20 healthy volunteers revealed a low level of CK20 expression in all samples. CONCLUSION: To study the clinical significance of CK20 expression as a marker of systemic metastatic disease it is essential to measure CK20 mRNA levels in hematopoietic tissue with sensitive quantitative RT-PCR. A sensitive and reproducible method, which is easily performed, is described.

Biomarkers, Tumor↗

Serum testosterone and sex hormone-binding globulin concentrations and the risk of prostate carcinoma: a longitudinal study.

BACKGROUND: It has been hypothesized that high androgen levels are determinants of prostate carcinoma. METHODS: Serum concentrations of testosterone, sex hormone-binding globulin (SHBG), and androstenedione were analyzed to determine their role as predictors of prostate carcinoma in a longitudinal, population-based, nested case-control study. The serum concentrations of testosterone, SHBG, and androstenedione were determined from serum samples collected by the Finnish Mobile Clinic Health Examination Survey between 1968-1972 and stored at -20 degrees C. During a follow-up period of 24 years, a total of 166 prostate carcinoma cases occurred among men who originally were cancer free. Two controls (matched for age and municipality) were chosen. RESULTS: There was no association between serum testosterone, SHBG, or androstenedione concentrations and the occurrence of subsequent prostate carcinoma in the total study population or in subgroups determined based on age or body mass index. The association was not strengthened by simultaneous adjustment for the hormonal variables. CONCLUSIONS: The results of the current study do not appear to corroborate the hypothesis that serum testosterone, SHBG, or androstenedione are determinants of the subsequent occurrence of prostate carcinoma.

Aged↗

Sensitive and quantitative one-step polymerase chain reaction using capillary electrophoresis and fluorescence detection for measuring cytokeratin 19 expression.

An improved quantitative assay to measure cytokeratin 19 (CK19) expression has been developed. The assay utilizes reverse transcription and a one-step polymerase chain reaction (PCR), with capillary electrophoresis and fluorescent labelling, to separate and detect the PCR products. Calibration curves were constructed from a serial dilution of CK19 cDNA coamplified with a fixed amount of CK19 internal standard, which was found to be linear between 10 and 500 molecules. Quantitative measurement of CK19 in samples was carried out by coamplifying the cDNA with a fixed amount of internal standard. The values were calculated from the calibration curve. The integrity of RNA and cDNA synthesis was checked by quantitative measurement of the breakpoint cluster region (BCR) gene expression. The assay is sensitive, detecting < 10 CK19 transcripts, and reproducible with a coefficient of variation of approximately 10%. CK19 expression showed overlapping values when measured in samples from peripheral blood and bone marrow in operable breast cancer patients, in healthy volunteers or patients without epithelial cancer and in blood samples from patients with metastatic breast cancer. As the assay is easier to perform than traditional quantitative competitive PCR assays, it might be useful for quantitative measurement of other specific transcripts.

Bone Marrow↗

Serum androgen-anabolic hormones and the risk of rheumatoid arthritis.

OBJECTIVE: It has been hypothesised, mainly on the basis of indirect evidence, that low serum concentrations of androgen-anabolic hormones would play a causal part in the aetiology of rheumatoid arthritis (RA). METHODS: A case-control study was nested with a Finnish cohort of 19,072 adults who had neither arthritis nor a history of it at the baseline examination during 1973-1977. Pre-illness serum specimens for the assay of testosterone and dehydroepiandrosterone sulphate (DHEAS) were available from 116 cases who had developed RA by late 1989. Three controls per each incident case were individually matched for sex, age, and municipality. RESULTS: The mean testosterone concentration was 1.4 nmol/l in those 84 women who developed RA and 1.4 nmol/l in their controls; the corresponding figures for DHEAS were 5.2 mumol/l and 5.5 mumol/l, respectively. Mean testosterone concentration in the 32 male cases was 26.1 nmol/l and 26.4 nmol/l in their controls; the corresponding figures for DHEAS were 11.2 mumol/l and 10.1 mumol/l, respectively. Analysis by subgroups (rheumatoid factor positive and negative disease, pre-menopausal and postmenopausal women) and by hormone distributions showed no differences. CONCLUSION: The findings are not in line with the contention that low concentrations of testosterone and DHEAS play a part in the aetiology of RA.

Adult↗

Purification of filaggrin from human epidermis and measurement of antifilaggrin autoantibodies in sera from patients with rheumatoid arthritis by an enzyme-linked immunosorbent assay.

BACKGROUND: The so-called antikeratin antibody (AKA) and the antiperinuclear factor (APF) that recognize proteins related to human epidermal filaggrin belong to the most specific serological markers of rheumatoid arthritis (RA). However, assays for the detection of AKA and APF are currently based on immunofluorescence, a method that is subject to arbitrary interpretation and inadequate standardization of the substrates. METHODS: Proteins extracted from human epidermis were separated by reversed-phase high-performance liquid chromatography (HPLC). Filaggrin-containing fractions, identified in immunoblotting by monoclonal antifilaggrin antibodies, were then subjected to gel filtration HPLC and, finally, to a second reversed-phase HPLC step. Tryptic digestion, amino acid sequencing and mass spectrometry were used to confirm the identity of the purified protein. Filaggrin was used as antigen in enzyme-linked immunosorbent assay (ELISA) to measure IgG class antifilaggrin antibodies. RESULTS: The filaggrin preparation obtained gave a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, binding monoclonal antifilaggrin antibody in immunoblotting. Amino acid sequences of all 10 tryptic peptides analyzed were shown to originate from human filaggrin. Antifilaggrin antibody levels exceeded the 99th percentile level of 100 middle-aged blood donors in 26/55 (47%) RA sera. At a similar cutoff level 28/55 (51%) of the RA sera were positive in the AKA test. Of the 26 antifilaggrin-positive sera, 21 were also AKA-positive. CONCLUSION: Human filaggrin can be purified by standard biochemical techniques, despite the heterogeneity of the protein, and used in ELISA for testing autoantibodies to filaggrin. The sensitivity of the assay equals that of the AKA test.

Adult↗

[Secondary myelodysplastic syndrome].

Secondary or therapy related myelodysplastic syndrome may develop following treatment with alkylating agents and radiotherapy. The condition may also follow high dose therapy for malignant lymphomas. We describe two patients who developed secondary myelodysplasia. The first is a 76-year old female with a low grade lymphoma who developed pancytopenia with monosomy 7. Secondary myelodysplasia was diagnosed 24 months after treatment with chlorambucil (total dose of 900 mg) and 12 months after treatment with trophosphamide (total dose of 24 g). The second patient was a 48-year old male who underwent autologous bone marrow transplantation for a relapsed low grade lymphoma. Following autografting he had persistent anemia and trombocytopenia. Secondary myelodysplastic syndrome with complex karyotype was diagnosed 54 months after high dose therapy. He died nine months later of bone marrow failure.

Adult↗

Serum immunoglobulins and the risk of rheumatoid arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is associated with several autoantibodies that can precede the clinical disease. The immunoglobulin concentrations in serum samples before illness were studied to learn more about the immunological process before RA. METHODS: A case-control study was nested within a Finnish cohort of 19,072 adults who had neither arthritis nor a history of it at the baseline examination during 1973-1977. By late 1989, 124 had developed RA, of which 89 were positive for rheumatoid factor (RF). Three controls per each incident case were individually matched for sex, age, and municipality. The concentrations of IgG, IgA, and IgM were measured from stored serum samples. RESULTS: Serum IgG before illness was found to be directly proportional to the risk of RF positive RA, and a non-linear association was present between serum IgA and the risk of RF positive RA. These associations were constant between men and women and other subgroups of the study population and not confounded by serum orosomucoid concentration, level of education, smoking, alcohol intake or body mass index. As adjusted for these factors, the odds ratios (95% confidence intervals) of RF positive RA in the lowest, mid, and highest tertiles of IgG distribution were 1.00, 1.55 (0.81, 2.97), and 2.22 (1.16, 4.26), and in the tertiles of IgA 1.00, 2.23 (1.14, 4.36), and 1.78 (0.89, 3.57), respectively. The associations persisted throughout the entire observation period but were most distinct when the period to the onset of clinical RA was > or = 10 years. IgM carried no predictive significance. None of the serum immunoglobulins predicted the development of RF negative RA. CONCLUSIONS: Increased IgG levels may reflect some, at present unknown process in the early events leading to the development of RA, typically occurring > or = 10 years before the onset of clinical disease.

Adult↗

[Diagnosis and follow-up in chronic myeloid leukemia. Detection and quantification of specific transcripts with the help of reverse transcriptase-polymerase chain reaction].

The Philadelphia chromosome in cells of patients with chronic myeloid leukemia and acute lymphoblastic leukemia can be detected by reverse transcriptase-polymerase chain reaction (RT-PCR). We have tested two new methods for this purpose. For diagnostic purposes, three different BCR-ABL translocations (b3a2, b2a2 and ela2) can be detected in a multiprimed, one step PCR reaction. By using a competitor DNA construct and a two-step, nested PCR reaction, a quantitative measure of the number of specific BCR-ABL transcripts can be estimated. We tested five patients with chronic myeloid leukemia. All of them showed positive BCR-ABL translocations in the diagnostic test. Patients with other myeloproliferative disorders, used as controls, were all negative. Quantitative measurements of specific BCR-ABL mRNA showed that as few as ten transcripts could be quantified in the assay. The analysis showed that coefficients of variation between 15% and 30% were obtained for specific transcripts per micrograms RNA, whereas specific BCR-ABL per normal ABL showed a coefficient of variation of 10%. These new methods to detect BCR-ABL translocation by RT-PCR should provide easy and sensitive diagnosis, and possibilities of monitoring residual disease or relapse.

Humans↗

Sex difference in the regulation of plasma high density lipoprotein cholesterol by genetic and environmental factors.

Association between high density lipoprotein (HDL) cholesterol concentration and restriction fragment length polymorphisms at the cholesteryl ester transfer protein (CETP) gene locus was studied in a random population-based cohort of 526 Caucasian subjects (259 men, mean age 50.9 years, and 267 women, mean age 51.8 years). HDL cholesterol concentration was adjusted for age, body mass index, alcohol consumption, smoking and plasma triglyceride and low density lipoprotein cholesterol levels. In females, the HDL cholesterol levels were associated with TaqIB polymorphism (1.46 mmol/l in the B1B1 genotype, 1.56 mmol/l in B1B2 and 1.72 mmol/l in B2B2, P = 0.0001 for the trend). In contrast, this was not observed in men (1.24, 1.20, 1.27 mmol/l, NS). The association was seen even in women who were current smokers (1.41, 1.56, 1.75 mmol/l, n = 72, P = 0.007), but not in male smokers (1.26, 1.19, 1.14 mmol/l, n = 102, NS). In male non-smokers the association was weak (1.22, 1.20, 1.32 mmol/l, n = 157, P = 0.05). In postmenopausal women not receiving hormone replacement therapy (n = 108), the association continued to be present, although weaker (1.50, 1.58, 1.70 mmol/l, P = 0.06). CETP activity (n = 101) tended to be lower in subjects with the B2B2 genotype. In conclusion, a clear-cut sex difference was observed in the genotype effect on plasma HDL cholesterol levels. The slight attenuation of the gene dosage effect after menopause suggests that the gender difference may be, at least in part, due to sex hormones. A genetic subgroup (men with the B2B2 genotype) particularly susceptible to the HDL cholesterol decreasing effect of smoking could be demonstrated.

Adult↗

Diagnosis of brain metastases from a primary hemangiosarcoma of the spleen with magnetic resonance imaging.

BACKGROUND: Primary malignant splenic neoplasms are rare tumors. Apart from involvement of the spleen by malignant lymphoma, hemangiosarcoma is the most common form of primary malignant neoplasm in the spleen. The diagnosis often is made at autopsy or after spontaneous splenic rupture. The prognosis is usually poor, and widespread metastases soon occur. METHOD: Currently, no case of metastasis to the brain has been reported to the authors' knowledge. RESULTS: This case report describes a patient who, as the first sign of metastatic disease, had symptoms from brain metastases 3 months after splenectomy. CONCLUSION: Magnetic resonance imaging was diagnostic.

Aged↗

Isolated congenital heart block. Long-term outcome of mothers and characterization of the immune response to SS-A/Ro and to SS-B/La.

OBJECTIVE: To study the long-term outcome of mothers of children with isolated congenital heart block (CHB) and to characterize the maternal autoantibody response to SS-A/Ro and SS-B/La. METHODS: A retrospective clinical study of 33 mothers a mean of 11.2 years (SD 9.2 years, range 0-32 years) after the delivery of their first child with CHB. A clinical and immunologic study of 31 of these mothers, compared with 89 healthy mothers, 45 mothers with systemic lupus erythematosus (SLE), and 19 mothers with primary Sjögren's syndrome (SS), all of whom had healthy children. The specificity of the autoantibody responses to SS-A/Ro and SS-B/La was studied by enzyme-linked immunosorbent assays using purified human recombinant antigens and affinity-purified antigens. RESULTS: By the time of the analysis, 2 (6%) of the 33 mothers of CHB children had died and 6 (18%) had met the criteria for SLE. As a group, mothers of CHB children had clinical and immunologic characteristics more closely related to primary SS than to SLE or any other connective tissue disease. The predominant autoantibody response was to the SS-A/Ro antigens, notably to the 52-kd SS-A/Ro protein (prevalence 97%). Compared with controls with SLE, mothers of CHB children had higher titers of antibodies to recombinant 52-kd and 60-kd SS-A/Ro proteins and to the affinity-purified SS-A/Ro antigen (P < 0.05, P < 0.01, and P < 0.001, respectively). Compared with controls with primary SS, the autoantibody responses were similar. CONCLUSION: The predominant autoimmune disorder in mothers of children with CHB is subclinical primary SS. Antibodies to SS-A/Ro appear to be a prerequisite for the development of CHB.

Adolescent↗

Testicular ultrasonography and 18G biopty biopsy for clinically undetected cancer or carcinoma in situ in patients with germ cell tumours.

The 18G Biopty biopsy has been evaluated as a tool to detect carcinoma in situ in the remaining testes of patients with extragonadal germ cell tumours or unilateral germ cell tumours. In all, 68 biopsies were performed in 57 selected patients. Five carcinomas in situ and 1 infiltrative seminoma were detected. The biopsies were performed under local anaesthesia. Pain and/or haematomas occurred after 9 of the 68 biopsies but none of the haematomas required invasive measures. This method of performing biopsies from clinically tumour-free testes seems promising but longer follow-up is required to evaluate the sensitivity of the method compared with open surgical biopsy.

Adult↗