Biomedical subjects

M G Karlsson

Publications and source records attributed to M G Karlsson.

At least 19 recordsLinked to original sources

PubMed2004

The prognostic significance of thymidine phosphorylase, thymidylate synthase and dihydropyrimidine dehydrogenase mRNA expressions in breast carcinomas.

Thymidine phosphorylase (TP), thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) have been indicated as possible predictive markers for epithelial malignancies. All these three enzymes are actively involved in 5-FU metabolism. In this report, we investigated mRNA expression of these factors with real-time quantitative PCR in a series of 86 micro-selected breast carcinomas and 8 micro-selected tumour-adjacent normal breast epithelial specimens. Highly variable mRNA expressions of these factors were observed in both normal and cancerous samples. TP and TS mRNA expressions in breast carcinomas were elevated, but only TS mRNA expression showed a trend for statistical difference, compared with the expression in normal breast epithelial samples. Although the DPD mRNA expression range in tumours was also elevated, the average mean was reduced in tumours compared to that in normal samples. No association between mRNA expressions of TP, TS and DPD and clinicopathological features such as histological grade, tumour size, node status, S-phase fraction, ploidy, and clinical stage was found. A negative association between DPD mRNA expression and age was, however, revealed. Ten-year follow-up analysis showed no association between TP and DPD mRNA expression and clinical outcome. An high level of TS mRNA expression, however, was associated with a shorter clinical survival, indicating its potential role as a clinical marker in breast carcinoma.

Adult↗

PubMed2004

Human saphenous vein and coronary bypass surgery: ultrastructural aspects of conventional and "no-touch" vein graft preparations.

Coronary artery bypass graft surgery (CABG) is routinely used to restore blood flow to diseased cardiac muscle due to coronary artery disease. The patency of conventional grafts decreases with time, which is due to thrombosis and formation of neointima. A primary cause of graft failure is the mechanical damage inflicted to the graft during harvesting, including removal of surrounding tissue accompanied by high pressure saline distension to overcome vasospasm (both causing considerable mechanical trauma). The aim of this study was to compare the ultrastructural features of human saphenous vein (SV) grafts harvested conventionally and grafts prepared using an atraumatic 'no-touch' harvesting technique introduced by Souza (1996). The results of this study showed a better preservation of the lumenal endothelium and medial vascular smooth muscle (SM) in 'no-touch' versus conventional grafts. A 'fast' (within 30 min) response of SM cells to conventional harvesting was noted where features of both SM cell division and apoptosis were observed. It is concluded that the 'preserved' nature of the 'no-touch' aortocoronary SV grafts renders them less susceptible to thrombotic and atherosclerotic factors than grafts harvested conventionally. These features are suggested to contribute to the improved early patency rate described using the no-touch technique of SV harvesting.

Aged↗

PubMed2004

Relation between HPV-DNA and expression of p53, bcl-2, p21WAF-1, MIB-1, HER-2/neu and DNA ploidy in early cervical carcinoma: correlation with clinical outcome.

The purpose of the present study was to analyze the relation between the expression of p53, bcl-2, p21WAF1, MIB-1, HER-2/neu, DNA ploidy and HPV16 or 18 infections with clinical parameters. HPV-DNA was evaluated in 171 early cervical carcinomas treated from 1965 to 1990 and detected by PCR (polymerase chain reaction) on paraffin specimens obtained before therapy was started. HPV-DNA of any type was detected in 78% (86/110) of all tumors, HPV16 was the predominant type and was seen in 56% (62/110), HPV18 in 8% (9/110) and HPV35 in 21% (23/110). Patients with HPV16 or 18 were significantly (P=0.011) younger than patients with tumors not containing these two HPV subtypes. Lymph node metastases were seen more frequently (P=0.047) in tumors expressing HPV16 or 18. Tumor size was associated with the HPV-type. The frequency of DNA aneuploidy was lower in high-risk HPV tumors than in tumors with other HPV subtypes (P=0.014). MIB-1 expression was highly significantly (P=0.00007) associated with presence of HPV16 or 18. The cancer-specific survival rate was lower for patients with HPV16 and 18 positive tumors, but the difference was not statistically significant. The overall 5-year survival rate of the complete series was 91%. In conclusion, the HPV DNA subtype was a prognostic factor in early stage cervical cancer and it was associated with age, positive lymph nodes, tumor size, DNA ploidy and the proliferation marker MIB-1.

Aneuploidy↗

PubMed2003

Clinicopathological associations of CD44 mRNA and protein expression in primary breast carcinomas.

AIMS: The purpose of this study was to examine the occurrence of CD44 isoforms in breast carcinomas and their role in predicting clinical outcome. METHODS AND RESULTS: Shock-frozen tumour tissues from 110 patients with breast carcinoma were examined by immunohistochemistry using antibodies directed against CD44s, v5, v6, v7 and v3-10. In addition, 80 of these tumours were available for quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of CD44s and CD44v6. Immunohistochemically, the positive tumours showed cytoplasmic and/or membranous staining with all antibodies. Staining results did not correlate with histological subtype, lymph node status, status of steroid receptors, tumour size or age. Neither was any correlation found for overall and disease-free survival. Quantitative real-time RT-PCR of CD44s and CD44v6, however, revealed that expression of CD44v6 mRNA was significantly associated with lower pathological grade (Pearson chi(2) test P = 0.009; linear-by-linear association P = 0.003). Linear-by-linear association between CD44s mRNA expression and lower pathological grade was also seen (P = 0.02). Survival analysis with the Kaplan-Meier method demonstrated that increased CD44s mRNA expression was significantly associated with both disease-free survival and overall survival (P = 0.0185 and P = 0.0344, respectively). A similar trend for CD44v6 mRNA expression was seen in these cases, but the difference was not significant. CONCLUSIONS: Quantitative real-time RT-PCR revealed clinical correlations of CD44s and CD44v6 mRNA expression in breast carcinomas while immunohistochemistry for the protein expression of CD44s and other CD44 variants did not. This contradictory result merits further studies concerning the clinical impact of CD44 molecules in breast carcinomas.

Adenocarcinoma↗

PubMed2001

Estrogen receptor-alpha and C-ERBB-4 expression in breast carcinomas.

The presence of estrogen receptors (ERs) in breast carcinomas is important for clinical response to endocrine therapy. However, the cellular mechanisms following ER activation are not fully understood. It has been indicated that expression of the ER is associated with the expression of c-erbB-4. To address this question, 103 breast carcinoma samples were studied using reverse transcriptase polymerase chain reaction (RT-PCR) analysis after application of a microselection method for RNA isolation. Total RNA for RT-PCR was isolated from 20-microm-thick frozen sections, which were made from microselected areas. Paraffin blocks from 98 of these 103 tumors were also immunohistochemically examined. Significant associations between ER-alpha and c-erbB-4 mRNA and protein expressions were found in the present study with both methods. One-fourth of the tumors did not express ER-alpha (22%, 24%, and 26% with chemical binding, immunohistochemistry, and RT-PCR, respectively). About one-half of the ER-alpha negative tumors did not express c-erbB-4 on both mRNA and protein levels (48% with RT-PCR and 46% with immunohistochemistry, P=0.001 for both methods). The endocrine therapy responsive breast cancer cell lines MCF-7 and T47-D were positive for both ER-alpha and c-erbB-4 expression, while the endocrine therapy nonresponsive breast cancer cell lines MDA-MD-231 and SK-BR-3 were not. Thus, we confirm the association between the expression of ER-alpha and c-erbB-4 mRNA and protein in breast carcinomas, indicating a role for c-erbB-4 in estrogen signal transduction.

Breast Neoplasms↗

PubMed2001

Expression of topoisomerase IIalpha in the G0/G1 cell cycle phase of fresh leukemic cells.

Topoisomerase IIalpha (topo IIalpha) is the target enzyme for several antineoplastic drugs. Correlation between low expression of topo IIalpha and drug resistance has been shown in vitro, but there is limited evidence of a correlation to initial response to treatment or to overall prognosis. Normal cells express topo IIalpha in S/G2/M phase of the cell cycle but not in G0/G1 phase. However, some data suggest that topo IIalpha could be expressed in G0/G1 phase in malignant cells. We have investigated the expression of topo IIalpha in leukemic cells from 25 patients with acute leukemia by flow cytometry, separating cells of different cell cycle phases. We demonstrated that 9/25 samples showed >50% positive cells in G0/G1, and another five samples showed >20%. This finding could possibly provide an explanation to previous difficulties in correlating topo IIalpha expression with clinical outcome. Six of eight patients, where >20% of the cells in G0/G1 were positive for topo IIalpha, entered CR, compared to one of five patients with <20% topo IIalpha positive cells in G0/G1. We suggest that topo IIalpha expression in G0/G1 in leukemic cells may be of predictive value for clinical response to cytostatic drugs.

Acute Disease↗

PubMed2001

Chlamydia pneumoniae in children undergoing adenoidectomy.

UNLABELLED: Chlamydia pneumoniae is a common respiratory pathogen which is often found in paediatric populations. Little is known about the true colonization rate and the localization of the bacteria in the respiratory tract. In this study, immunohistochemistry was used to examine adenoids from 69 children undergoing elective adenoidectomy. Throat swabs for polymerase chain reaction (PCR) and blood samples for serology were also obtained. Chlamydia pneumoniae was demonstrated in the adenoids by immunohistochemistry in 68 of the children. Five children (7%) had a positive C. pneumoniae PCR test from throat swabs and 14 children (20%) had detectable antibodies by the microimmunofluorescence technique. CONCLUSION: The results suggest that C. pneumoniae is a common finding in the adenoids of children undergoing adenoidectomy. Whether or not C. pneumoniae plays a pathogenic role in this patient population could not be determined from the data obtained in this investigation.

Adenoidectomy↗

PubMed2000

Tumor mapping of regional immunostaining for p21, p53, and mdm2 in locally advanced bladder carcinoma.

BACKGROUND: The aim of this study was to elucidate the associations among immunostaining for p53, p21, and mdm2; their respective expression within each tumor; and the value of these variables for predicting treatment outcome after cystectomy for patients with locally advanced bladder carcinoma. METHODS: The hospital records from all 173 patients treated with cystectomy for locally advanced urothelial bladder carcinoma between 1967 and 1992 were retrospectively reviewed. Three consecutive sections from biopsies taken before any treatment were stained using the standard immunohistochemical technique for p53, p21, and mdm2, respectively. The cutoff limit was 20% or more for positive p53 expression and 10% or more for positive p21 and mdm2 expression. RESULTS: Positive immunostaining was observed for p53 in 98 tumors (57%), for p21 in 89 tumors (51%), and for mdm2 in only 16 tumors (9%). The only association found between immunostaining for the three antibodies was that most mdm2-positive tumors had positive p21 expression. Tumor mapping of regional immunostaining showed no association between immunostaining for p53 and p21. In a proportional hazards analysis, no association was found between the results of immunostaining for the three antibodies and treatment outcome. CONCLUSIONS: Positive or negative expression of p53, p21, or mdm2, or combinations of these, was not associated with cancer specific mortality after cystectomy for bladder carcinoma. There was no association between immunostaining for p21 and p53, whereas positive immunostaining for mdm2 was observed in a minority of the tumors. These results indicate that, in addition to p21, p53, and mdm2, there are other oncoproteins and tumor suppressor proteins along the p53 pathway that are involved in tumor development and progression.

Adult↗

PubMed2000

Th1-like dominance in high-risk first-degree relatives of type I diabetic patients.

AIMS/HYPOTHESIS: The humoral part of the immune system, including autoantibodies, is known to predict manifest Type I (insulin-dependent) diabetes mellitus in first-degree relatives but the cell-mediated immune process preceding the manifest disease still is not known. The aim of this investigation was to estimate the immunological balance of Th-like lymphocytes (Th1/Th2) in high-risk first-degree relatives of Type I diabetic children. METHODS: Peripheral blood mononuclear cells (PBMC) from 21 healthy high-risk first-degree relatives (ICA > or = 20) were examined and compared with the response seen in PBMC from children with newly diagnosed Type I diabetes and healthy control subjects of similar age, sex and HLA-type. Expression of interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) mRNA were determined by RT-PCR and as protein by ELISPOT after stimulation with specific epitopes of GAD65 (a.a. 247-279, 509-528, 524-543), bovine serum albumin, the ABBOS peptide (a.a. 152-169) and insulin. RESULTS: High-risk relatives had a high ratio of IFN-gamma:IL-4 compared with both diabetic children (p = 0.0005) and healthy control subjects (p = 0.004). Production of IFN-gamma seen in high-risk relatives was negatively correlated to production of GADA (r = -0.44, p = 0.05). The high concentration of IFN-gamma from high-risk relatives, decreased after stimulation with peptides of GAD65, the ABBOS peptide, BSA and insulin. Increased secretion of IL-4 was observed after stimulation with two peptides of GAD65 (a.a. 509-528 and 524-543), the ABBOS peptide and insulin. CONCLUSION/INTERPRETATION: Overwhelming production of IFN-gamma seen in peripheral blood mononuclear cells from high-risk first-degree relatives of children with Type I diabetes suggests a Th1-like immune deviation in the prediabetic phase.

Adolescent↗

PubMed2000

The ABBOS-peptide from bovine serum albumin causes an IFN-gamma and IL-4 mRNA response in lymphocytes from children with recent onset of type 1 diabetes.

The ABBOS-peptide from bovine serum albumin (BSA) in cow's milk has been suggested to initiate the autoimmune process against the beta-cells leading to type 1 diabetes. The aim of this study was to elucidate if the ABBOS-peptide is a possible trigger of type I diabetes. The cytokines IL-4 and IFN-gamma were determined at the level of transcription as mRNA in lymphocytes, stimulated with the ABBOS-peptide. Sixteen children with newly diagnosed type 1 diabetes were compared with 10 healthy controls matched for the diabetes associated HLA-type DR3/4. Antibodies to bovine serum albumin (BSA), insulin antibodies (IA), and antibodies against islet cells (ICA) were determined, as well as serum C-peptide. Increased mRNA expression for IFN-gamma and/or IL-4 could be observed in lymphocytes from 13/16 children with recent onset of diabetes after in vitro stimulation with the ABBOS-peptide. Low expression of IFN-gamma mRNA was associated with high secretion of C-peptide, whereas a positive relationship could be observed between expression of IL-4 mRNA and insulin antibodies. Expression of IFN-gamma and/or IL-4 mRNA was also detected in lymphocytes from 6/10 healthy controls. ABBOS may have a role as a reactive epitope in the upregulation of the autoimmune process against the beta-cells but ABBOS does not seem to cause any specific Th1 response. An increased mRNA expression could also be seen in lymphocytes from healthy controls. Thus, the ABBOS-peptide might just cause or reflect an unspecific immune activity.

Adolescent↗

PubMed1999

Epidermal growth factor receptor expression: predictive value for the outcome after cystectomy for bladder cancer?

OBJECTIVE: To determine whether epidermal growth factor receptor (EGFR) immunostaining of tumour cells is associated with cancer-specific death after cystectomy for locally advanced bladder cancer. PATIENTS AND METHODS: The hospital records of all patients treated with cystectomy for urothelial cancer of the urinary bladder between 1967 and 1992 were reviewed retrospectively. The paraffin-embedded specimens obtained before treatment from 173 patients were processed for immunohistochemical staining, using the monoclonal antibody NCL-EGFR (Novocastra, UK). EGFR immunostaining was considered positive if membrane staining was found in at > or = 20% of tumour cells in one or more fields at > or = 200 (area 0.59 mm2). RESULTS: Most patients (149) received preoperative irradiation and one had neoadjuvant chemotherapy. The mean observation time was 81.3 months; 63 patients (36%) had tumour recurrence within 1-80 months (mean 18.3). Positive EGFR immunostaining was found in 100 patients (58%). The proportion of T2-4 tumours was higher in those EGFR-positive than in those EGFR-negative. Proportional-hazards analysis revealed that clinical stage was significantly associated with cancer-specific death, but EGFR expression was not. CONCLUSION: Although positive immunostaining for EGFR was more frequent in higher stages of locally advanced bladder cancer, this variable was not an independent predictor of outcome after cystectomy.

Adult↗

PubMed1999

Methods for the determination of effective monitor chamber thickness.

There are a number of models, both analytical and Monte Carlo, which are used to describe the fluence from the treatment head of accelerators. One common problem in these simulations is to find relevant information about details in the treatment head. A complex unit in the treatment head for which reliable data is seldom given is the monitor chamber. In this work two methods are described for obtaining this information by analyzing the increased scattering of an electron beam when the monitor chamber is introduced in the beam. It was found that the effective thickness of the electrodes in a monitor chamber can be determined with sufficient accuracy by using experimental results combined with Fermi-Eyges theory or Monte Carlo simulations.

Biophysical Phenomena↗

PubMed1999

Treatment head design for multileaf collimated high-energy electrons.

This paper describes how a conventional treatment head can be modified for use of multileaf collimated electron beams. Automatic and dynamic beam delivery are possible for both electrons and photons by using the computer controlled multileaf collimator (MLC) for both photon and electron beams. Thereby, the electron beams can be mixed more freely into the treatment to take advantage of the specific depth modulation characteristics of electrons. The investigation was based on Monte Carlo calculations using the software package BEAM. The physical parameters used in this optimization were the beam penumbra and the virtual/effective point source position. These parameters are essential for shaping beams, beam matching and for dosimetry calculations. The optimization was carried out by modifying a number of parameters: replacing the air atmosphere in the treatment head with helium, adding a helium bag below the MLC, changing the position of the scattering foils, modifying the monitor chamber, and adjusting the position of the MLC. The beam characteristics for some of these designs were found to fulfil our criteria for clinically useful beams down to at least 9 MeV.

Computer Simulation↗

PubMed1998

Peptide from glutamic acid decarboxylase similar to coxsackie B virus stimulates IFN-gamma mRNA expression in Th1-like lymphocytes from children with recent-onset insulin-dependent diabetes mellitus.

At the clinical onset of insulin-dependent diabetes mellitus (type 1 diabetes), inflammation within the pancreatic islets of Langerhans causes insulitis. CD4+ or Th-lymphocytes will be activated after stimulation resulting in interferon-gamma (IFN-gamma) production by Th1-like lymphocytes and/or interleukin-4 (IL-4) secretion from Th2-like lymphocytes. The antigens responsible for this activation are unknown, but studies have suggested glutamic acid decarboxylase (GAD) to be a possible candidate. One peptide from this enzyme (amino acid 247-279) with a similar amino acid sequence to coxsackie B virus may cause lymphocyte proliferation in diabetic patients. In this study we have shown that this peptide activates Th1-like lymphocytes which produce increased amounts of IFN-gamma mRNA, but seldom mRNA for IL-4. Lymphocytes from healthy HLA-matched controls (DR3/4) did not respond with an upregulated mRNA expression for these cytokines when stimulated by the GAD-peptide (P<0.05). A low or absent expression of IFN-gamma mRNA was significantly correlated to a high fasting C-peptide at 3 months' duration (P<0.05). In conclusion, we suggest that GAD65 is involved in the development of type 1 diabetes and that the Th1-response may play a role in the destruction of beta cells.

Adolescent↗

PubMed1998

Differences in CD14 and alpha-naphthyl acetate esterase positivity and relation to prognosis in AML.

Alpha-naphthyl acetate esterase (ANAE) and CD14 expression, used for determination of monocytic cells, were compared and related to prognosis in 65 AML patients. Bone marrow aspiration material from AML patients has been used for the cytochemistry as well as flow cytometry. All non-erythroid cells have been included in the evaluation in both methods. 17/65 cases showed at least 15% difference between the proportion CD14 and ANAE positive cells. Cases with 20% or more CD14 positivity had poorer prognosis. For FAB classes M0-M3, presence of 10% or more CD14 was negative for overall survival (P = 0.01). ANAE did not show significant prognostic influence.

Acute Disease↗

PubMed1998

Determination of mRNA expression for IFN-gamma and IL-4 in lymphocytes from children with IDDM by RT-PCR technique.

Insulin-dependent diabetes mellitus (IDDM) is characterized by infiltration of T-lymphocytes in the islets of Langerhans. Antigens are presented to Th-lymphocytes which can be divided into Th1- and Th2-lymphocytes, producing interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) respectively. The aim of our study was to determine the messenger-RNA (mRNA) for these cytokines by RT-PCR in antigen-stimulated lymphocytes from children with newly diagnosed IDDM. The expression of mRNA for IL-4, and to a lesser degree IFN-gamma, is increased in lymphocytes stimulated with tetanus toxoid (TT). Loss of activity after freezing and thawing could be compensated for, by increased amplification, while the use of EDTA or sodium heparin in the blood samples did not influence the results. In a pilot application, the lymphocytes from children with newly diagnosed IDDM were stimulated with a peptide of glutamic acid decarboxylase (GAD) (a.a. 247-279) known to have a similar aminoacid sequence as the Coxsackie B virus (a.a. 32-47). Increased IFN-gamma mRNA could be seen in two out of four children, whereas IL-4 showed a less pronounced mRNA expression. No increased mRNA expression for IFN-gamma and IL-4 could be seen in healthy HLA-matched controls. Further studies are needed to confirm whether increased IFN-gamma mRNA in Th1-like lymphocytes stimulated with this specific GAD-peptide play a role in the cell-mediated immune response seen in children early after the onset of IDDM.

Adolescent↗

PubMed1998

Intensity modulation with electrons: calculations, measurements and clinical applications.

Intensity modulation of electron beams is one step towards truly conformal therapy. This can be realized with the MM50 racetrack microtron that utilizes a scanning beam technique. By adjusting the scan pattern it is possible to obtain arbitrary fluence distributions. Since the monitor chambers in the treatment head are segmented in both x- and y-directions it is possible to verify the fluence distribution to the patient at any time during the treatment. Intensity modulated electron beams have been measured with film and a plane parallel chamber and compared with calculations. The calculations were based on a pencil beam method. An intensity distribution at the multileaf collimator (MLC) level was calculated by superposition of measured pencil beams over scan patterns. By convolving this distribution with a Gaussian pencil beam, which has propagated from the MLC to the isocentre, a fluence distribution at isocentre level was obtained. The agreement between calculations and measurements was within 2% in dose or 1 mm in distance in the penumbra zones. A standard set of intensity modulated electron beams has been developed. These beams have been implemented in a treatment planning system and are used for manual optimization. A clinical example (prostate) of such an application is presented and compared with a standard irradiation technique.

Calibration↗

PubMed1998

Predictive value of p53 and pRb immunostaining in locally advanced bladder cancer treated with cystectomy.

PURPOSE: We elucidate the association between altered immunostaining for retinoblastoma gene protein (pRb) and p53 nuclear proteins, and cancer specific death in patients treated with cystectomy for locally advanced bladder cancer. MATERIALS AND METHODS: The hospital records of 173 patients treated with cystectomy for advanced urothelial bladder cancer between 1967 and 1992 were retrospectively reviewed. Representative biopsies obtained before treatment were sectioned and stained using the standard immunohistochemical technique with antibody DO-7 (p53) and antibody PMG3-245 (pRb). A tumor was considered to have an altered p53 expression if 20% or more of tumor cells exhibited nuclear staining. Similarly, if no tumor cell had nuclear immunostaining the tumor was considered to have an altered pRb expression. RESULTS: An altered expression was observed for p53 in 98 tumors (57%) and for pRb in 60 (35%). In a proportional hazards analysis no association was found between an altered expression of pRb or p53 and cancer specific death. This finding was also true in another analysis when the results of immunostaining for pRb and p53 were combined. CONCLUSIONS: An altered expression for pRb and/or p53 was not correlated to cancer specific death. Thus, these parameters could not be used as predictors of treatment outcome after cystectomy for locally advanced bladder cancer.

Adult↗