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Biomedical subjects

Staffan Nilsson

Publications and source records attributed to Staffan Nilsson.

At least 19 recordsLinked to original sources

Genome-wide linkage scan for breast cancer susceptibility loci in Swedish hereditary non-BRCA1/2 families: suggestive linkage to 10q23.32-q25.3.

The two breast cancer genes BRCA1 and BRCA2 were identified more than 10 years ago and, depending on population, mutations in these genes are responsible for a varying percentage of familial breast cancer. In more than half the families, the increased risk of breast cancer cannot be explained by mutations in these genes, and the goal of this study was to locate novel susceptibility genes. One of the main difficulties in identifying the cause of hereditary non-BRCA1/BRCA2 breast cancer is genetic heterogeneity, possibly due to multiple, incompletely penetrant susceptibility genes, along with ethnic and geographic differences. In this study, one large family and 13 small to medium-sized families with multiple cases of breast cancer were analyzed by genome-wide linkage analysis. The genome scan was performed by genotype analysis of 10,000 SNP markers on microarrays. The strongest evidence of linkage (HLOD 2.34) was obtained on chromosome region 10q23.32-q25.3. A further two regions were identified, with LOD scores above 2.10 on 12q14-q21 and 19p13.3-q12. In a subset of families of western Swedish origin, two regions generated LOD scores exceeding 1.8: 10q23.32-q25.3 and 19q13.12-q13.32. The large family in the study exceeded LOD 1.5 in three regions: 10q23.32-q25.3, 19q13.12-q13.32, and 17p13. Our results indicate that one or more of the suggested regions may harbor genes that are involved in the development of breast cancer.

Breast Neoplasms↗

Nanoparticle-based continuous full filling capillary electrochromatography/electrospray ionization-mass spectrometry for separation of neutral compounds.

Highly efficient reversed-phase capillary electrochromatography (CEC) separations (plate numbers up to 700 000/m), with electrospray ionization mass spectrometry detection were achieved utilizing novel dextran-coated polymer nanoparticles as a pseudostationary phase. A continuous full filling (CFF) technique in which nanoparticles are continuously introduced into the capillary was employed for separation of neutral analytes (dialkyl phthalates), utilizing an orthogonal electrospray interface to prevent nanoparticles from entering the mass spectrometer. CFF-CEC benefits from that an entirely fresh column is employed for every analysis, avoiding carryover effects associated with stationary-phase contamination. The highly efficient separations obtained were accomplished by optimizing the organic modifier concentration in the electrolyte and by using a high nanoparticle concentration (5 mg/mL), to improve interparticle mass transfer and gain sufficient retention. Nanoparticles, with an average diameter of 600 nm, were prepared by polymerization of methacrylic acid and trimethylolpropane trimethacrylate, which in turn were coated with dextran. These nanoparticles formed stable suspensions in electrolytes having broad ranges of polarities, enabling straightforward optimization of the reversed-phase conditions.

Capillary Electrochromatography↗

The very obese woman and the very old woman: tension-free vaginal tape for the treatment of stress urinary incontinence.

A mailed questionnaire was sent to 970 consecutive women who underwent a tension-free vaginal tape (TVT) procedure between 1995 and 2001 at the Department of Obstetrics and Gynecology in Falun Hospital. Seven hundred and sixty (78.4%) women responded. The outcome was compared between women older than 75 years (n=113) and younger women, and between women with a body mass index (BMI) above 35 (n=61) and those who had normal weight. Mean follow-up was 5.7 years. Thirty-six elderly women and one of the obese women were deceased at the long-term follow-up. TVT was easy to perform and was a safe procedure for women in all groups. There was a sharp decrease in cure rate of any urinary incontinence problems among women aged 75 years or more (55.7%), as compared to those who were younger (79.7%). The cure rate moderately decreased from BMI groups 19-24 to 30-34. BMI > or =35 seemed to be the best explanatory cutoff level. The overall cure rate in women of normal weight was 81.2%, as compared to 52.1% in the very obese. The cure rate for urinary incontinence with tension-free vaginal tape in women above 75 years of age and in women with a BMI above 35 was acceptable, but lower as compared to the remaining study population.

Adult↗

Frequency of de novo urgency in 463 women who had undergone the tension-free vaginal tape (TVT) procedure for genuine stress urinary incontinence--a long-term follow-up.

BACKGROUND: To determine risk factors for the appearance of de novo urgency symptoms, and subsequent accompanying problems, after the tension-free vaginal tape (TVT) procedure in women with stress urinary incontinence. METHOD: A structured preoperative analysis of the incontinence symptoms was made. A mailed questionnaire was distributed to 970 women that underwent the TVT procedure between 1995 and 2001. Average follow-up was 5.2 years (range 2-8 years). The questionnaire included specific questions on current urinary symptoms and incontinence. The disease-specific quality of life instruments IIQ-7 and UDI-6 were used to compare women with, and those without de novo urgency. RESULTS: Seven hundred and sixty women (78.3%) responded and 463 of those were identified as genuine stress incontinence preoperatively. De novo urgency occurred in 67 (14.5%) of the women. The frequency was similar irrespective of duration since the TVT procedure. The women that reported de novo urgency symptoms were compared with those without symptoms. Risk factors for occurrence of de novo urgency symptoms were older age (64.7 years versus 60.9 years; p=0.01), parity (2.6 versus 2.3; p=0.05), history of cesarean section (9.5% versus 2.5%; odds ratio 5.4), and history of recurrent urinary infections (29.7% versus 18.8%; odds ratio 1.6, but non-significant. De novo urgency had a severe impact on quality of life, as compared to the remaining study population. CONCLUSION: Old age, parity and history of cesarean section were risk factors for de novo urgency after TVT surgery. Postoperative de novo urgency symptoms are as bothersome for the patient as the preoperative stress urinary incontinence.

Age Factors↗

Serum C-reactive protein concentration and genotype in relation to ischemic stroke subtype.

BACKGROUND AND PURPOSE: C-reactive protein (CRP) has evolved as an inflammatory risk marker of cardiovascular disease. Several single-nucleotide polymorphisms at the CRP locus have been found to be associated with CRP levels. The aim of the present study was to investigate CRP levels and genetic variants in etiological subtypes of ischemic stroke. METHODS: The Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS) comprises 600 consecutive ischemic stroke cases (18 to 69 years) and 600 matched controls from western Sweden. Stroke subtypes were defined by the TOAST classification. Serum CRP levels were determined by a high-sensitivity immunometric assay. RESULTS: CRP levels were significantly higher for all ischemic stroke subtypes compared with controls, both in the acute phase and at the 3-month follow-up. After adjustment for traditional risk factors, CRP at follow-up was related to higher odds ratios (ORs) of overall ischemic stroke (OR, 1.25; 95% CI, 1.09 to 1.43) and large-vessel disease (OR, 1.48; 95% CI, 1.09 to 2.00). The CRP -286C>T>A, 1059G>C, and 1444C>T single-nucleotide polymorphisms showed significant associations with CRP levels. However, neither CRP genotypes nor haplotypes showed an association to overall ischemic stroke. CONCLUSIONS: This is the first large study on CRP in different TOAST subtypes in a young ischemic stroke population. CRP levels differed between etiological subtypes of ischemic stroke both in the acute phase and at the 3-month follow-up. CRP at follow-up was associated with overall ischemic stroke and the large-vessel disease subtype. Genetic variants at the CRP locus were associated with CRP levels, but no association was detected for overall ischemic stroke.

Adult↗

Interleukin-1 system gene polymorphisms are associated with fat mass in young men.

CONTEXT: There is growing evidence for interactions between the regulation of body fat and the immune system. Studies of knockout mice indicate that IL-1 has an antiobesity effect. OBJECTIVE: The objective of the study was to investigate our hypothesis that common polymorphisms of the IL-1 system, which are associated with IL-1 activity, also are associated with fat mass. DESIGN, SETTING, AND STUDY SUBJECTS: The Gothenburg Osteoporosis and Obesity Determinants (GOOD) study is a population-based cross-sectional study of 18- to 20-yr-old men (n = 1068), mostly Caucasian, from the Gothenburg area (Sweden). Three different polymorphisms, IL-1beta +3953 C/T, IL-1beta-31 T/C, and IL-1 receptor antagonist (IL-1RN) variable number tandem repeat of 86 bp, were investigated in relation to body fat mass. MAIN OUTCOME MEASURE: The main outcome measures were genotype distributions and their association with body fat mass in different compartments, measured with dual-energy x-ray absorptiometry. RESULTS: Carriers of the T variant (CT and TT) of the +3953 C to T (F(T) = 0.25) IL-1beta gene polymorphism had significantly lower total fat mass (P = 0.013) and also significantly reduced arm, leg, and trunk fat, compared with CC individuals. IL-1RN*2 carriers with two repeats of the IL-1RN variable number tandem repeat polymorphism had increased total fat (P = 0.036), serum leptin, and fat of trunk and arm as well as serum levels of IL-1RN and IL-1RN production ex vivo. The IL-1beta-31 polymorphism did not correlate with the fat measurements. CONCLUSIONS: The IL-1 system, recently shown to affect fat mass in experimental animals, contains gene polymorphisms that are associated with fat mass in young men.

Absorptiometry, Photon↗

Nanoparticle-based pseudostationary phases in capillary electrochromatography.

During the past decades, research has been performed to enhance selectivity in CE by introducing different types of additives into the electrolyte. Research concerning this has taken many directions, especially during the last 5 years. A promising technique, which benefits from no packing or frits, is to use nanoparticles as the pseudostationary phase (PSP) in CEC. PSPs have the advantage of introducing a novel interaction phase for every analysis, which greatly simplify column exchange and circumvent contamination inherited from complex mixtures, e.g., biological samples. The field of nanoparticle-based PSPs used in CEC is covered in this review. The term CEC will be used consequently throughout this review, although some authors used the term EKC to categorize their work. Important requirements for the nanoparticles used and possible reasons for band broadening will be discussed. Applications with silica nanoparticles, polymer nanoparticles, molecularly imprinted polymer nanoparticles, gold nanoparticles, dendrimers, and polymeric surfactants as PSP will also be discussed.

Chromatography, Micellar Electrokinetic Capillary↗

Analysis of chromosome 5q31-32 and psoriasis: confirmation of a susceptibility locus but no association with SNPs within SLC22A4 and SLC22A5.

We have previously reported a region on chromosome 5q as a possible susceptibility region for psoriasis. This cytokine cluster-rich region has also been suggested as a susceptibility locus in other autoimmune or inflammatory diseases including Crohn's disease (CD) and rheumatoid arthritis (RA). Three specific single-nucleotide polymorphisms (SNPs) have been reported to associate with RA and CD and to change the functional activity of two organic cation transporters, solute carrier family 22 member 4/5 (SLC22A4) and (SLC22A5). In this study, we have analyzed these SNPs for an association with psoriasis. We have also performed a denser linkage analysis of this region with an additional 31 microsatellite markers. We were not able to detect any association with any of the three SNPs analyzed. However, our linkage result supports the involvement of this region in the etiology of psoriasis. We obtained a peak non-parametric linkage value of 3.1 for marker D5S436 in a subgroup of patients with joint complaints. This result supports the findings in another study of psoriasis patients originating from Iceland in which the authors obtained a peak logarithm of the odds score of 2.6 for marker D5S2090, only 2 Mb from D5S436. This suggests a psoriasis susceptibility locus on chromosome 5q32 that is involved in the arthritic phenotype of the disease.

Chromosome Mapping↗

Pubertal timing predicts previous fractures and BMD in young adult men: the GOOD study.

UNLABELLED: The importance of pubertal timing for adult BMD in males was studied through association of pubertal timing with young adult bone phenotype. Pubertal timing was found to predict both cortical and trabecular volumetric BMD and previous fractures in young adult men. Thus, late puberty is a risk factor for low BMD and previous fractures in young adult men. INTRODUCTION: Peak bone mass (PBM), achieved during puberty, is a determinant of the risk for osteoporosis and future fractures. The role of variations within the normal range in pubertal timing for fractures during pubertal development and for adult bone mass in men is unknown. MATERIALS AND METHODS: The aim of this study was to investigate the importance of pubertal timing for adult BMD and for fractures before achievement of PBM in men. The population-based Gothenburg Osteoporosis and Obesity Determinants (GOOD) study is a well-characterized cohort of young adult Swedish males 18-20 years of age. Detailed growth charts from birth to 18-20 years of age were retrieved for 642 men participating in the GOOD study. Age at peak height velocity (PHV) was estimated and used as an assessment of pubertal timing. The skeletal phenotype was analyzed at young adult age using DXA and pQCT and previous fractures were assessed by questionnaires. RESULTS: Age at PHV was a negative independent predictor of both adult cortical and trabecular volumetric BMD and of total body and radius areal BMD. Moreover, age at PHV was associated with previous fractures in a logistic regression analysis. The OR for cortical osteopenia was 2.49 (95% CI, 1.91-3.24; p < 0.001) and for previous upper limb fractures was 1.35 (95% CI, 1.04-1.75; p < 0.05) per year increment in age at PHV. CONCLUSIONS: Age at PHV is a negative independent predictor of BMD and a positive predictor of previous fractures in young adult men. Longitudinal studies to determine if pubertal timing also predicts BMD and fractures in elderly men are required.

Absorptiometry, Photon↗

Pubertal timing is an independent predictor of central adiposity in young adult males: the Gothenburg osteoporosis and obesity determinants study.

The role of puberty and normal variations in pubertal timing for the development of obesity in men is unclear. The aim of the current study was to investigate the impact of pubertal timing and prepubertal BMI (kg/m(2)) for young adult BMI and fat mass distribution. Detailed growth charts from birth to age 18-20 years were retrieved for the men participating in the population-based Gothenburg Osteoporosis and Obesity Determinants study. Age at peak height velocity (PHV) and BMI at age 10 years were estimated for 579 subjects, and PHV was used as an assessment of pubertal timing. The fat mass characterization and distribution were analyzed using dual X-ray absorptiometry and peripheral as well as abdominal computed tomography at age 18.9 +/- 0.5 years. We demonstrate that age at PHV is an independent negative predictor of young adult BMI and whole-body fat mass. Interestingly, age at PHV is an independent negative predictor of central, but not peripheral, fat mass. In contrast, BMI at 10 years of age predicts both central and peripheral subcutaneous fat mass. In conclusion, we demonstrate that early pubertal onset specifically predicts a central fat mass distribution, while a predominantly subcutaneous obese phenotype is strongly predicted by a high prepubertal BMI.

Absorptiometry, Photon↗

Fibrinolytic gene polymorphism and ischemic stroke.

BACKGROUND AND PURPOSE: The tissue-type plasminogen activator (tPA) -7351C>T and the plasminogen activator inhibitor type 1 (PAI-1) -675 4G>5G polymorphisms influence transcriptional activity. Both variants have been associated with myocardial infarction, with increased risk for the T and 4G allele, respectively. In this study we investigated the possible association between these polymorphisms, the respective plasma protein levels, and ischemic stroke. METHODS: In the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS), 600 patients with acute ischemic stroke aged 18 to 69 years and 600 matched community controls were recruited. Stroke subtype was determined using Trial of Org 10172 in Acute Treatment criteria. RESULTS: There were no associations between individual genetic variants and ischemic stroke. The multivariate-adjusted odds ratio for overall ischemic stroke was 1.11 (95% CI 0.87 to 1.43) for tPA T allele carriers, and 0.84 (95% CI, 0.64 to 1.11) for subjects homozygous for the PAI-1 4G allele. When genotypes were combined, a protective effect for the tPA CC/PAI-1 4G4G genotype combination was observed (odds ratio 0.65, 95% CI 0.43 to 0.98; P<0.05). Plasma levels of tPA and PAI-1 antigen at follow-up were independently associated with overall ischemic stroke. tPA-antigen differed by stroke subtype and was highest among those with large-vessel disease and cardioembolic stroke. CONCLUSIONS: Neither the tPA -7351C>T nor the PAI-1 to 675 4G>5G polymorphism showed significant association with ischemic stroke. For the tPA CC/PAI-1 4G4G genotype combination, a protective effect was observed. Collectively, these results are consistent with a more complex role for tPA and PAI-1 in the brain as compared with the heart.

Adolescent↗

Interaction of polymorphisms in the genes encoding interleukin-6 and estrogen receptor beta on the susceptibility to Parkinson's disease.

The multifunctional cytokine interleukin-6 (IL-6) is involved in inflammatory processes in the central nervous system and increased levels of IL-6 have been found in patients with Parkinson's disease (PD). It is known that estrogen inhibits the production of IL-6, via action on estrogen receptors, thereby pointing to an important influence of estrogen on IL-6. In a previous study, we reported an association between a G/A single nucleotide polymorphism (SNP) at position 1730 in the gene coding for estrogen receptor beta (ERbeta) and age of onset of PD. To investigate the influence of a G/C SNP at position 174 in the promoter of the IL-6 gene, and the possible interaction of this SNP and the ERbeta G-1730A SNP on the risk for PD, the G-174C SNP was genotyped, by pyrosequencing, in 258 patients with PD and 308 controls. A significantly elevated frequency of the GG genotype of the IL-6 SNP was found in the patient group and this was most obvious among patients with an early age of onset (</=50 years) of PD. When the GG genotypes of the IL-6 and ERbeta SNPs were combined, the combination was much more robustly associated with PD, and especially with PD with an early age of onset, than respective GG genotype when analyzed separately. Our results indicate that the G-174C SNP in the IL-6 promoter may influence the risk for developing PD, particularly regarding early age of onset PD, and that the effect is modified by interaction of the G-1730A SNP in the ERbeta gene.

Age of Onset↗

Investigation of genes coding for inflammatory components in Parkinson's disease.

Several findings obtained recently indicate that inflammation may contribute to the pathogenesis in Parkinson's disease (PD). Genetic variants of genes coding for components involved in immune reactions in the brain might therefore influence the risk of developing PD or the age of disease onset. Five single nucleotide polymorphisms (SNPs) in the genes coding for interferon-gamma (IFN-gamma; T874A in intron 1), interferon-gamma receptor 2 (IFN-gamma R2; Gln64Arg), interleukin-10 (IL-10; G1082A in the promoter region), platelet-activating factor acetylhydrolase (PAF-AH; Val379Ala), and intercellular adhesion molecule 1 (ICAM-1; Lys469Glu) were genotyped, using pyrosequencing, in 265 patients with PD and 308 controls. None of the investigated SNPs was found to be associated with PD; however, the G1082A polymorphism in the IL-10 gene promoter was found to be related to the age of disease onset. Linear regression showed a significantly earlier onset with more A-alleles (P = 0.0095; after Bonferroni correction, P = 0.048), resulting in a 5-year delayed age of onset of the disease for individuals having two G-alleles compared with individuals having two A-alleles. The results indicate that the IL-10 G1082A SNP could possibly be related to the age of onset of PD.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

Defining women who are prone to have twins in in vitro fertilization--a necessary step towards single embryo transfer.

PURPOSE: The aim of the present study was to identify subsets of women undergoing two-embryo transfer in in vitro fertilization (IVF) who are prone to give birth to twins. METHODS: During 1990 to 2002 4580 day 2 or day 3 two-embryo transfers were conducted and these constituted the study population. RESULTS: By selecting combinations of factors, some subsets of patients where single-embryo transfer might be conducted would reduce the estimated twin rate by 60%, but requiring single-embryo transfer in only approximately one third of the patients. Examples of such selected groups were patients less than 33 years of age with two top quality embryos, patients less than 39 years of age with two top quality embryos and conducting their first IVF cycle, and patients less than 39 years of age with two top quality embryos and two optimal cleavage cells. CONCLUSION: By combining factors, subsets of patients with both a high birth and twin rate that could be recommended single embryo transfer were identified.

Adult↗

Low expression of reduced folate carrier-1 and folylpolyglutamate synthase correlates with lack of a deleted in colorectal carcinoma mRNA splice variant in normal-appearing mucosa of colorectal carcinoma patients.

BACKGROUND: Cellular folate deficiency leads to DNA strand breaks, mutations, and aberrant methylation and might be a risk factor for colorectal cancer (CRC). The putative tumor suppressor gene deleted in colorectal carcinoma (DCC) is one of several genes the expression of which seems to be affected by the folate concentration at the tissue level. Decreased expression of DCC may be caused by LOH or hypermethylation, i.e. by events that might be linked to folate deficiency. The purpose of this study was to analyze if the folate level and the gene expression levels of reduced folate carrier (RFC-1) and folylpolyglutamate synthase (FPGS) had impact on the expression of DCC splice variants. METHODS: Quantification of RFC-1 and FPGS expression in mucosa of 53 CRC patients was performed using real-time PCR whereas DCC splicing variants were detected by automated capillary gel electrophoresis. Total reduced folate concentration was measured with the FdUMP-binding assay (n = 22). RESULTS: Significantly higher expression levels of RFC-1 (p = 0.026) and FPGS (p = 0.05) were found in mucosa expressing the splice variant DCC342 compared to mucosa that did not. Furthermore, multivariate analysis showed that RFC-1 and FPGS (r = 0.49, p = 0.01) as well as folate and RFC-1 (r = 0.56, p = 0.023) were correlated only in mucosa expressing DCC342. CONCLUSIONS: In conclusion, the present study points to a potential influence of folates in regulating DCC expression at multiple levels involving post-transcriptional pathways. The results may provide a basis for a detailed investigation of molecular mechanisms involved in folate regulation of DCC expression.

Adenocarcinoma↗

Imbalance of the mitochondrial pro- and anti-apoptotic mediators in neuroblastoma tumours with unfavourable biology.

It has been proposed that a lack of apoptosis plays an important role in neuroblastoma (NB) progression. We therefore screened cDNA array filters, including 198 apoptotic genes, in order to identify mRNA transcripts that are differentially expressed in tumours with unfavourable versus favourable biology. Twenty-one genes were analysed further using real-time reverse-transcriptase-polymerase chain reaction (RT-PCR). Significantly lower levels of DNCL1 (PIN; P(c)(corrected) = 0.0054) and NTRK1 (TrkA; P(c) = 0.039) were found in NB tumours with unfavourable biology. In addition, BID, BCL2, APAF1, CASP2, CASP3 and CASP9 were found to be preferentially expressed in tumours with favourable biology, whereas CDKN1A (p21), IL2RA, and MCL1, were found to be preferentially expressed in NB tumours with unfavourable biology. In conclusion, mRNA levels of transcripts encoding pro-apoptotic mediators of the mitochondrial apoptotic pathway were found to be expressed to a lower extent in tumours with unfavourable biology. Our data also suggest that the mitochondrial pathway is suppressed in advanced stages of NB tumours, due to an imbalance between anti-apoptotic and pro-apoptotic mediators which is a finding that may have therapeutic significance.

Apoptosis↗

Promising results with 306 single blastocyst transfers.

Single blastocyst transfer was performed in 306 IVF patients during 2002 to August 2003 in women younger than 39 years of age with at least five fertilized oocytes. Viable pregnancy rate per single blastocyst transfer was 40.7% during 2002 and 47.6% during 2003 (amounting to 35% of all IVF cycles), which in our experience are acceptable results.

Adult↗

Sex steroid-related genes and male-to-female transsexualism.

Transsexualism is characterised by lifelong discomfort with the assigned sex and a strong identification with the opposite sex. The cause of transsexualism is unknown, but it has been suggested that an aberration in the early sexual differentiation of various brain structures may be involved. Animal experiments have revealed that the sexual differentiation of the brain is mainly due to an influence of testosterone, acting both via androgen receptors (ARs) and--after aromatase-catalyzed conversion to estradiol--via estrogen receptors (ERs). The present study examined the possible importance of three polymorphisms and their pairwise interactions for the development of male-to-female transsexualism: a CAG repeat sequence in the first exon of the AR gene, a tetra nucleotide repeat polymorphism in intron 4 of the aromatase gene, and a CA repeat polymorphism in intron 5 of the ERbeta gene. Subjects were 29 Caucasian male-to-female transsexuals and 229 healthy male controls. Transsexuals differed from controls with respect to the mean length of the ERbeta repeat polymorphism, but not with respect to the length of the other two studied polymorphisms. However, binary logistic regression analysis revealed significant partial effects for all three polymorphisms, as well as for the interaction between the AR and aromatase gene polymorphisms, on the risk of developing transsexualism. Given the small number of transsexuals in the study, the results should be interpreted with the utmost caution. Further study of the putative role of these and other sex steroid-related genes for the development of transsexualism may, however, be worthwhile.

Adult↗