Biomedical subjects

P Eriksson

Publications and source records attributed to P Eriksson.

At least 37 records · Page 2Linked to original sources

PubMed2004

Matrix metalloproteinase-26 (matrilysin-2) expression is high in endometrial hyperplasia and decreases with loss of histological differentiation in endometrial cancer.

OBJECTIVE: Matrix metalloproteinases (MMPs) are key players in the degradation of extracellular matrix and basement membranes, and are thus important in tumor invasion. Recently, MMP-26 (endometase), a novel matrilysin-type member of the MMP family, was cloned from an endometrial tumor. This study examines the expression of MMP-26 mRNA in hyperplastic, premalignant and malignant endometrial samples, and compares with normal endometrial tissue. METHODS: Endometrial carcinoma samples (19) were histologically classified as well, intermediately and poorly differentiated. Samples with hyperplasia (n = 15) were classified as simple, complex, or complex with atypia. Normal endometrial specimens (n = 39) were classified according to an ideal 28-day menstrual cycle and subsequently grouped in the early, middle, and late parts of the cycle. All samples were analyzed using in situ hybridization and real time PCR. The probes used for in situ hybridization and real time PCR recognized non-overlapping sequences. MMP-26 protein was localized by immunohistochemistry. RESULTS: MMP-26 mRNA was exclusively localized in the epithelial component of normal, hyperplastic, premalignant, as well as malignant samples. It was not found in the stroma of any tissue category. Quantifications with real time PCR as well as semi-quantifications of the in situ hybridization signal revealed maximal levels in normal tissue at midcycle and in endometrial hyperplasia both with and without atypia. The amount of MMP-26 mRNA decreased progressively with loss of histological differentiation in malignant samples. Immunostaining localized MMP-26 in epithelial glandular and luminal cells, in vessel walls, and in tumor cells. Since the pattern of MMP-26 expression mimicked that of ER-alpha, we searched the MMP-26 promoter region for a potential estrogen response element (ERE). A sequence at position -130 to -116 had high homology to the consensus sequence of an ERE. Based on these observations, we suggest that ER-alpha is involved in regulation of the MMP-26 gene. CONCLUSIONS: MMP-26 mRNA is selectively localized in the epithelial compartment of normal, hyperplastic, and malignant endometrial tissue. Expression is high in normal and hyperplastic endometria, but is downregulated in the late part of the cycle and in malignant tumors. The expression pattern of MMP-26 mRNA mimics that of ER-alpha, and the promoter region of the MMP-26 gene has a potential ERE.

Adult↗

PubMed2004

Relationship between beta-2 adrenoceptor gene haplotypes and adipocyte lipolysis in women.

BACKGROUND AND AIMS: The beta(2)-adrenergic receptors are important for adipocyte lipolysis regulation by catecholamines in humans. The beta(2)-adrenoceptor gene is highly polymorphic. The role of these genetic variations for adipocyte lipolysis was investigated. DESIGN AND METHODS: Six single-nucleotide polymorphisms (SNPs) in the promotor region and four SNPs in the coding region (leading to amino-acid substitution) of the beta(2)-adrenoceptor gene were determined in 141 overweight or obese, but otherwise healthy women. Lipolysis experiments were performed on isolated subcutaneous adipocytes. RESULTS: Three homozygous haplotypes (6/6, 4/4 and 2/2) were found that differed about 500-fold in noradrenaline sensitivity or beta(2)-adrenoceptor sensitivity (6/6>2/2>4/4, P=0.01). The haplotypes also differed by 100% in maximum noradrenaline-induced lipolysis rates (6/6>2/2>4/4). However, there was no influence on beta(1)-, beta(3)- or alpha(2)A-adrenoceptor sensitivity. Heterozygosity at one or several SNPs in the haplotypes influenced the beta(2)-adrenoceptor sensitivity significantly. CONCLUSION: Multiple SNPs in the beta(2)-adrenoceptor gene form several haplotypes that markedly influence beta(2)-receptor function- and catecholamine-induced lipolysis in fat cells. These haplotypes may be important genetic factors behind impaired lipolysis in obesity.

Adipocytes↗

PubMed2004

Continuous ST-segment monitoring of patients with left bundle branch block and suspicion of acute myocardial infarction.

OBJECTIVES: Patients with left bundle branch block comprise 5-9% of all patients with acute myocardial infarction. Limited data exist on the usefulness of continuous electrocardiographic monitoring of these patients. We have investigated prospectively the usefulness of real-time continuous vectorcardiography for monitoring patients with left bundle branch block and suspicion of acute myocardial infarction. DESIGN: A prospective multi-centre study. SETTING: Fourteen Swedish coronary care units. SUBJECTS: Patients with left bundle branch block and suspicion of acute myocardial infarction with <6-h symptom duration were included. MAIN OUTCOME MEASURES: All patients were monitored with continuous vectorcardiography for 12-24 h. RESULTS: One hundred thirty-three patients were included, 47% had acute myocardial infarction. Patients with acute myocardial infarction showed a marked relative decrease in ST-vector than those without (P = 0.0002). These changes were most marked in the first 90 min. When comparing patients with acute myocardial infarction receiving thrombolytic therapy or not, those treated with thrombolytics showed more marked decline in ST-vector magnitude (P < 0.0001) and in shorter time (P = 0.0017). All patients showed STC-vector magnitude changes that were more marked in patients with acute myocardial infarction (P = 0.0002). An STC-vector magnitude cut-off value of 65 microV after 90 min of monitoring gave 54% sensitivity and 72% specificity for diagnosis of acute myocardial infarction. CONCLUSION: Real-time continuous vectorcardiographic monitoring of patients with left bundle branch and suspicion of acute myocardial infarction shows significant differences between those with and without acute myocardial infarction and could be of use for early diagnosis and subsequent monitoring.

Aged↗

PubMed2004

Use of gene therapy in central nervous system repair.

Recent advances have increased our molecular understanding of the central nervous system (CNS), in both health and disease. In order to realize the clinical benefits of these findings, new molecular-based therapies need to be developed, such as CNS gene therapy. Although the field has suffered setbacks, it remains an attractive technology for providing new therapies in the post-genomic world. The development of new vectors, and their extensive application in animal models of CNS disease, provides evidence suggesting that gene therapy will eventually become an accepted clinical option. In fact, the first gene therapy clinical trial for Parkinson's disease has recently begun. This review discusses how gene therapy has been applied in animal models, and how it may be used to repair the damage caused by CNS diseases and trauma in human beings. Furthermore, it explores how such treatments may be combined with, and augment, more conventional therapeutic approaches.

Animals↗

PubMed2004

Relationship between serum levels of IL-18 and IgG1 in patients with primary Sjögren's syndrome, rheumatoid arthritis and healthy controls.

Primary Sjögren's syndrome (SS) is characterized by inflammation in salivary and lachrymal glands, with a local predominance of Th1-like cytokines, as well as the pleiotropic cytokine interleukin (IL) 18. High serum levels of polyclonal IgG are common, with a subclass imbalance in which IgG1 is increased and IgG2 is normal or low. IL-18 is also of pathogenetic importance in rheumatoid arthritis. In the present study we looked for any relationship between serum IL-18 as well as transforming growth factor (TGF) beta1 versus IgA, IgM, and IgG subclass levels in SS (n = 16), rheumatoid arthritis (RA) (n = 15), and healthy controls (n = 15). SS was defined by the revised American-European classification criteria. IL-18 and TGF-beta1 were analyzed with enzyme immunoassays (EIA), and IgG1, IgG2 and IgG3 by single radial immunodiffusion. In the composite group of RA, SS and normal controls, IgG1 and IL-18 were related (R = 0.52, P = 0.0005). No relation was found neither between IL-18 versus IgG2, IgG3 or IgA, nor between serum TGF-beta1 versus any of the immunoglobulins. Since serum levels of IL-18 are related to serum IgG1, IL-18 may be of importance for IgG1 switch and/or release.

Adult↗

PubMed2004

Genetic and structural evaluation of fatty acid transport protein-4 in relation to markers of the insulin resistance syndrome.

Disturbances in fatty acid metabolism are involved in the etiology of insulin resistance and the related dyslipidemia, hypertension, and procoagulant state. The fatty acid transport proteins (FATPs) are implicated in facilitated cellular uptake of nonesterified fatty acids (NEFAs), thus potentially regulating NEFA concentrations and metabolism. The aim of this study was to investigate polymorphic loci in the FATP4 gene with respect to associations with fasting and postprandial lipid and lipoprotein variables and markers of insulin resistance in 608 healthy, middle-aged Swedish men and to evaluate possible mechanisms behind any associations observed. Heterozygotes for a Gly209Ser polymorphism (Ser allele frequency 0.05) had significantly lower body mass index and, correcting for body mass index, significantly lower triglyceride concentrations, systolic blood pressure, insulin concentrations, and homeostasis model assessment index compared with common homozygotes. A three-dimensional model of the FATP4 protein based on structural and functional similarity with adenylate-forming enzymes revealed that the variable residue 209 is exposed in a region potentially involved in protein-protein interactions. Furthermore, the model indicated functional regions with respect to NEFA transport and acyl-coenzyme A synthase activity and membrane association. These findings propose FATP4 as a candidate gene for the insulin resistance syndrome and provide a structural basis for understanding FATP function in NEFA transport and metabolism.

Amino Acid Sequence↗

PubMed2004

[Endometrial expression profiles of mRNA for selected matrix metalloproteinases and tissue inhibitor of metalloproteinases-1].

OBJECTIVE: To examine the endometrial expression pattern of messenger RNA (mRNA) for selected matrix metalloproteinases (MMP) and tissue inhibitor of metalloproteinases-1 (TIMP-1). DESIGN: Experimental study. SETTING: Department of Obstetrics and gynecology of the Palacky University Medical School and University Hospital, Olomouc, Czech Republic, Department of Obsterics and Gynecology, University Hospital, Luna, Sweden. METHODS: We studied MMP-1, -3, -7, -10, -11, -12, -13, -14, -16, -26 and TIMP-1 mRNA in 39 normal endometrial samples obtained across the menstrual cycle. Based on histological examination, all specimens were classified according to an ideal 28 day menstrual cycle as early (n=8), mid (n=6) and late (n=7) proliferative phase, early (n=4), mid (n=4) and late (n=8) secretory phase and menstrual (n=3) phase. mRNA extracted from frozen tissue samples was quantitated using real time PCR. RESULTS: Four distinct patterns of MMP mRNA expression were detected in cycling endometrium. MMP-1, -3, -10, and -12 were expressed predominantly in perimenstrual period, MMP-7 and -11 had highest levels in proliferative phase, MMP-13, -14 and -16 were expressed throughout the cycle and MMP-26 was found to be maximal in periovulatory period. Levels of TIMP-1 mRNA remained unchanged during the cycle. CONCLUSION: The specific endometrial expression profiles of MMPs during menstrual cycle point to their specific biologic roles during the cycle. MMP-26 exhibits a unique expression pattern.

Adult↗

PubMed2003

Gene expression and intracellular pathways involved in endothelial dysfunction induced by VLDL and oxidised VLDL.

OBJECTIVES: The molecular mechanisms underlying the relationship between elevated plasma concentrations of triglyceride-rich lipoproteins and coronary artery disease remain uncertain. In the present work, we investigated the gene expression pattern and intracellular pathways in human endothelial cells incubated with very low density lipoproteins (VLDL). Moreover, as VLDL can enter the arterial wall and undergo oxidative modification, we compared the VLDL-induced expression pattern with the one of oxidised VLDL (Ox-VLDL). METHODS: Total RNA from endothelial cells incubated with 75 microg/ml VLDL or Ox-VLDL and total RNA from endothelial cells under basal conditions were hybridised to identical microarrays containing 8411 genes. Seven clusters of expression profiles were identified. This pattern was validated by quantitative real-time PCR of selected genes. The intracellular pathway involved in VLDL or Ox-VLDL mediated endothelial responses were also investigated. RESULTS AND CONCLUSION: VLDL predominantly activated the ERK1/2 pathway while P38 MAPK was the main target of Ox-VLDL. CREB and NF-kappa B were activated by both VLDL and Ox-VLDL. Real-time PCR demonstrated that VLDL induced matrix metalloproteinase-2 (5.47+/-1.74 fold), CD38 (2.38+/-0.23) and transforming growth factor-alpha (2.51+/-0.30) expression. Ox-VLDL was found to induce interleukin-15 (2.10+/-0.48) and macrophage migration inhibitory factor (3.19+/-0.07) expression. In addition, several genes implicated in endothelial cell activation and damage/proliferation were identified by the array analysis. Ox-VLDL was found to promote the generation of reactive oxygen species and exert a cytotoxic effect, while VLDL lacks these effects. These findings confirm the involvement of VLDL and Ox-VLDL in endothelial dysfunction and suggest new genes and molecular mechanisms involved in these actions.

Cell Death↗

PubMed2003

A common polymorphism in the fatty acid transport protein-1 gene associated with elevated post-prandial lipaemia and alterations in LDL particle size distribution.

The fatty acid transport proteins (FATPs) have been implicated in facilitated cellular uptake of non-esterified fatty acids (NEFAs), thus having the potential to regulate local and systemic NEFA concentrations and metabolism. Hypothesising that genetic variation within the FATP genes may affect lipid metabolism, we investigated a G/A substitution at position 48 in intron 8 of the fatty acid transport-1 (FATP1) gene with respect to associations with fasting and post-prandial plasma lipid and lipoprotein variables in 628 healthy 50-year-old Swedish men and 426 Swedish women, aged 37-65 years. A subset of 105 men with the apoE3/E3 genotype underwent an oral fat tolerance test. Although fasting plasma TG concentrations were not different, male A/A individuals had significantly higher post-prandial TG concentrations and VLDL(1) (S(f) 60-400 apoB100)-to-VLDL(2) (S(f) 20-60 apoB100) ratio compared to male G/A and G/G individuals. A/A individuals apparently failed to suppress plasma NEFA concentrations during the oral fat tolerance test. Furthermore, fasting plasma concentrations of the largest, most buoyant LDL subfraction (LDL-I) were significantly lower in carriers of the A allele in the male cohort. Electromobility shift assays and reporter gene studies indicated that binding of nuclear factors and effect on transcriptional activity differ between the intron 8 alleles. These findings suggest that through regulation of NEFA trafficking, FATP1 might play a role in post-prandial lipid metabolism and development of cardiovascular disease.

Adult↗

PubMed2003

Epithelial expression of matrix metalloproteinase-26 is elevated at mid-cycle in the human endometrium.

The human endometrium is a dynamic tissue, which undergoes extensive tissue remodelling during the menstrual cycle. Due to their involvement in such processes, several well-characterized matrix metalloproteinases (MMP) have previously been studied in the endometrium. MMP-26 is a newly described matrilysin. We studied MMP-26 mRNA in 39 normal endometrial samples obtained across the menstrual cycle. Tissue distribution and cycle variation was examined using in-situ hybridization, Northern blot analyis and real time PCR. The probes for Northern blot analysis and real time PCR recognized non-overlapping sequences. MMP-26 was localized exclusively in epithelial cells of both glands and the luminal surface. Expression increased during the proliferative phase to a maximum at mid-cycle, then decreased to non-detectable levels in the late secretory and menstrual phases. Expression of MMP-26 mRNA in endometrial tissue explants in vitro required stimulation with both estradiol and progesterone. The tissue content of c-jun mRNA was assayed, since c-jun, as part of the enhancer complex AP-1, may be involved in regulation of MMP-26 gene transcription. The pattern of c-jun expression over the menstrual cycle was similar to that of MMP-26. Epithelial expression in the peri- and post-ovulatory stages of the menstrual cycle suggests the involvement of MMP-26 in reproductive processes.

Actins↗

PubMed2002

The influence of 4G/5G polymorphism in the plasminogen activator inhibitor-1 gene promoter on the incidence, growth and operative risk of abdominal aortic aneurysm.

BACKGROUND: a single base pair deletion/insertion (4G/5G) polymorphism in the plasminogen activator inhibitor (PAI-1) promoter appears to influence PAI-1 synthesis (increased PAI-1 and inhibition of fibrinolysis with the 4G allele) and survival after severe trauma. OBJECTIVE: to identify whether the 4G/5G polymorphism influences the natural history of abdominal aortic aneurysm (AAA). METHODS: Four hundred and sixty patients with small AAA were genotyped for the 4G/5G polymorphism. AAA growth was assessed from serial ultrasonographic measurements, subject to linear regression analysis. Mortality following eventual elective surgery was recorded. RESULTS: the frequency of the 3 genotypes (4G4G, 4G5G and 5G5G) was in Hardy-Weinberg equilibrium and similar to that in a healthy population. The mean aneurysm growth rate was 0.37, 0.35 and 0.44 cm/year respectively for patients of 4G4G, 4G5G and 5G5G genotype respectively, p = 0.07. The 30d mortality following open elective aneurysm repair was 8% (7/87), 8% (11/145) and 0% (0/56) for patients of 4G4G, 4G5G and 5G5G genotype respectively, giving a higher mortality for those carrying a 4G allele p = 0.03. CONCLUSIONS: polymorphism of the PAI-1 gene promoter does not influence the development of AAA, although AAA growth is faster for patients of 5G5G genotype. However, this genotype (5G5G), which is associated with enhanced fibrinolysis, appears protective following open aneurysm repair. This effect of PAI-1 genotype on survival following surgery is likely to have widespread significance in vascular and general surgery.

Aged↗

PubMed2002

Plasma tumour necrosis factor-alpha and early carotid atherosclerosis in healthy middle-aged men.

AIMS: Tumour necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine, which is implicated in some metabolic disorders and may play a role in the development of cardiovascular disease. We examined whether plasma TNF-alpha is related to established cardiovascular risk indicators, plasma levels of soluble cellular adhesion molecules and carotid artery intima-media thickness determined by ultrasound examination in a population-based cohort of 96 healthy 50-year-old men. METHODS AND RESULTS: TNF-alpha and cellular adhesion molecules were measured with enzyme-linked immunosorbent assays. Plasma TNF-alpha concentration was associated with systolic and diastolic blood pressure, degrees of alimentary lipaemia, plasma very low density lipoprotein triglyceride, low density lipoprotein (LDL) cholesterol concentrations and peak LDL particle size. Two indices of insulin resistance as well as all soluble cellular adhesion molecules correlated positively with TNF-alpha. The plasma TNF-alpha concentration was associated with common carotid intima-media thickness in univariate analysis. In contrast, soluble E-selectin and postprandial triglycerides, but not TNF-alpha, were independent determinants of common carotid intima--media thickness. CONCLUSION: The plasma TNF-alpha concentration is associated with degrees of early atherosclerosis and correlates with metabolic and cellular perturbations that are considered important for the vascular process.

ATPases Associated with Diverse Cellular Activitie↗

PubMed2002

A polymorphism in the leptin promoter region (-2548 G/A) influences gene expression and adipose tissue secretion of leptin.

There is a large inter-individual variation in circulating leptin concentrations at each level of body fat content. The reason for this is unknown. We investigated whether a polymorphism in the promoter region of the leptin gene (-2548G/A) influences gene transcription and leptin expression in 39 non-obese female subjects. Eleven subjects were homozygous for the AA genotype, 18 were heterozygous (GA) and 10 carried the GG genotype. AA subjects had higher levels of serum leptin than did GA/GG subjects (14.5 +/- 2.1 vs. 9.7 +/- 0.9 ng/ml, p = 0.02). Adipose tissue leptin secretion rate in AA subjects was twice as high as in GA/GG subjects: 1158 +/- 288 vs. 626 +/- 84 ng/2 h/10 (7) cells (p = 0.02). These differences were also statistically significant with leptin levels adjusted for body mass index (p = 0.03 - 0.04). Adipose tissue leptin mRNA levels were 60 % higher in AA subjects, as compared to GA/GG subjects, 74 +/- 10 vs. 46 +/- 4 amol/ micro g RNA (p = 0.01). EMSA revealed that nuclear extracts derived from both U937 cells and human adipocytes form a protein-DNA complex with the leptin -2548G/A polymorphic site and bind with higher affinity to the -2548A-site. In conclusion, a common polymorphism in the promoter of the human leptin gene (-2548G/A) influences leptin expression, possibly at the transcriptional level, and therefore also adipose secretion levels of the hormone.

Adipose Tissue↗

PubMed2002

A brominated flame retardant, 2,2',4,4',5-pentabromodiphenyl ether: uptake, retention, and induction of neurobehavioral alterations in mice during a critical phase of neonatal brain development.

Polybrominated diphenyl ethers (PBDEs) are used in large quantities as flame retardant additives. In a recent study, we have seen that neonatal exposure to some brominated flame retardants can cause permanent aberrations in spontaneous motor behavior that seem to worsen with age. In view of an increasing amount of PBDEs in mother's milk and in the environment, the present study was undertaken to investigate whether there is a critical and limited phase, during neonatal life, for induction of persistent neurotoxic effects of 2,2',4,4',5-pentaBDE (PBDE 99). Neonatal NMRI male mice were exposed on day 3, 10, or 19 to 8 mg 2,2',4,4',5-pentaBDE/kg body weight. Uptake and retention of 2,2',4,4',5-penta[(14)C]BDE were studied in the mouse brain after exposure to 1.5 M becquerel (Bq) 2,2',4,4',5-penta[(14)C]BDE /kg body weight (bw) on postnatal day 3, 10, or 19. Spontaneous motor behavior was observed in 4-month-old mice. Mice exposed to 2,2',4,4',5-pentaBDE on day 3 or 10 showed significantly impaired spontaneous motor behavior, whereas no effect was seen in mice exposed on day 19. Neonatal mice exposed to 2,2',4,4',5-penta[(14)C]BDE 99 on postnatal day 3, 10, or 19 were sacrificed 24 h or 7 days posttreatment. The amount of radioactivity, given as per mille ( per thousand) of total amount administered, was between 3.7 and 5.1 per thousand in the three different age categories at 24 h after administration. Seven days after the administration, 2,2',4,4',5-penta[(14)C]BDE or its metabolites could still be detected in the brain. The amount of radioactivity in the brain was not higher in mice exposed on day 3 or 10 when compared to exposure on day 19. Thus, the behavioral disturbances observed in adult mice following neonatal exposure to 2,2',4,4',5-pentaBDE are induced during a defined critical period of neonatal brain development.

Animals↗

PubMed2001

Neurobehavioural defects in adult mice neonatally exposed to nicotine: changes in nicotine-induced behaviour and maze learning performance.

Neonatal exposure to low doses of nicotine has been shown to disturb the development of low-affinity nicotinic binding sites in the cerebral cortex and to elicit a deviant behavioural response to nicotine in adult mice. In this study, 10-day-old male NMRI mice were exposed to one of three different doses of nicotine (3.3, 33, or 66 microg nicotine-base/kg body wt.) s.c. twice daily on 5 consecutive days to study dose-response effects of nicotine on adult spontaneous and nicotine-induced motor behaviour. The nicotine-induced behaviour test revealed a hypoactive response to nicotine in 4-month-old mice neonatally exposed to 33 or 66 microg nicotine-base, whereas the response to nicotine in control animals and mice exposed to 3.3 microg nicotine-base was an increased activity. Learning and memory functions were also investigated in adult animals neonatally exposed to 66 microg nicotine-base/kg body wt. in the same manner, in the Morris water maze and in the Radial arm maze. In the swim maze and the Radial arm maze tests, no significant differences were observed between nicotine-treated and control animals at the age of 4 months. At 7 months, however, a significant difference in performance was evident, indicating a time-response/time-dependent effect. Furthermore, it was shown that in mice exposed neonatally to a nicotine dose known to inhibit the development of the nicotinic low affinity-binding site (LA), the response to nicotine could not cause any increase in spontaneous motor activity as seen in controls.

Age Factors↗

PubMed2001

Spt16-Pob3 and the HMG protein Nhp6 combine to form the nucleosome-binding factor SPN.

Yeast Spt16/Cdc68 and Pob3 form a heterodimer that acts in both DNA replication and transcription. This is supported by studies of new alleles of SPT16 described here. We show that Spt16-Pob3 enhances HO transcription through a mechanism that is affected by chromatin modification, since some of the defects caused by mutations can be suppressed by deleting the histone deacetylase Rpd3. While otherwise conserved among many eukaryotes, Pob3 lacks the HMG1 DNA-binding motif found in similar proteins such as the SSRP1 subunit of human FACT. SPT16 and POB3 display strong genetic interactions with NHP6A/B, which encodes an HMG1 motif, suggesting that these gene products function coordinately in vivo. While Spt16-Pob3 and Nhp6 do not appear to form stable heterotrimers, Nhp6 binds to nucleosomes and these Nhp6-nucleosomes can recruit Spt16-Pob3 to form SPN-nucleosomes. These complexes have altered electrophoretic mobility and a distinct pattern of enhanced sensitivity to DNase I. These results suggest that Spt16-Pob3 and Nhp6 cooperate to function as a novel nucleosome reorganizing factor.

Alleles↗

PubMed2001

Polymorphisms in the thrombopoietin gene are associated with risk of myocardial infarction at a young age.

Five polymorphisms in the thrombopoietin (TPO) gene were identified, one in the 5' untranslated region (UTR) (C1796T), two within intron 5 (C4830A and A4877C), and two in the 3' UTR (A5713G and A6160T). The allele frequencies were determined in a group of 450 healthy middle aged men from the UK and found to be 0.46 for 1796T, 0.38 for 4830A, 0.004 for 4877C, 0.47 for 5713G and 0.07 for 6160T. Genotypes for the three common polymorphisms were determined in a group of 176 young male Swedish survivors of a myocardial infarction (MI) and 186 age-matched controls and a group of 156 young Italian survivors of an MI and 147 age and sex matched controls. In both the Swedish and the Italian studies polymorphisms were found to be associated with increased risk of MI. In the Swedish sample the frequency of 4830A was significantly higher in controls (0.40) compared with patients (0.29) (P=0.003), with an odds ratio for AA homozygotes of 0.48 (0.25-0.92; P=0.03) compared with CC homozygotes. In the Italian sample the frequency of 5713G was significantly lower in controls (0.31) compared with cases (0.40) (P=0.03), with an odds ratio for GG homozygotes of 2.29 (1.08-4.89; P=0.03) compared with AA homozygotes. These risk associations are consistent since 4830A and 5713A show strong allelic association. After adjusting for other measured risk factors the effect on risk was still significant in the Italian sample 2.39 (1.02-5.58), but not in the Swedish sample 0.46 (0.16-1.32). The observation of frequency differences between cases and controls in two independent samples strongly suggests that the TPO gene is involved as a risk factor for developing MI at a young age, but the identified polymorphisms are probably acting as markers for an unidentified functional mutation elsewhere in the gene locus.

Adult↗

PubMed2001

The developing cholinergic system as target for environmental toxicants, nicotine and polychlorinated biphenyls (PCBs): implications for neurotoxicological processes in mice.

During neonatal life, offspring can be affected by toxic agents either by transfer via mother's milk or by direct exposure. In many mammalian species the perinatal period is characterized by a rapid development of the brain - "the brain growth spurt" (BGS). This period in the development of the mammalian brain is associated with numerous biochemical changes that transform the feto-neonatal brain into that of the mature adult. In rodents, the cholinergic transmitter system undergoes a rapid development during the neonatal period, a time when spontaneous motor behaviour also reaches peak activity. We have observed that low-dose exposure to environmental toxicants such as nicotine, polychlorinated biphenyls (PCBs) and polybrominated diphenylethers (PBDE, flame retardants) during the "BGS" can lead to irreversible changes in adult brain function in the mouse. The induction of persistent effects on behaviour and cholinergic nicotinic receptors in the adult animal appears to be limited to a short period during neonatal development. Furthermore, the neurotoxic effects were shown to develop over time, indicating a time-response/time-dependent effect. This indicates that environmental toxicants, such as nicotine, PCBs and probably PBDEs, might be involved in the slow, implacable induction of neurodegenerative disorders and/or interfere with normal aging processes.

Journal Article↗