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P J Karhunen

Publications and source records attributed to P J Karhunen.

At least 19 recordsLinked to original sources
PubMed2006

Indoleamine 2,3-dioxygenase activity in nonagenarians is markedly increased and predicts mortality.

Indoleamine 2,3-dioxygenase (IDO), an enzyme degrading tryptophan (trp) to kynurenine (kyn), suppresses T cell activity. Ageing of the immune system, immunosenescence, includes a decline in T cell function. We therefore sought to establish whether IDO activity is involved in immunosenescence and whether it predicts mortality in aged subjects. We measured kyn/trp, reflecting IDO activity, in 284 nonagenarians and 309 blood donor controls. IDO activity was significantly higher in nonagenarians compared with controls and IDO activity at study entry predicted subsequent mortality in nonagenarians. Thus, increased IDO activity might be a mechanism involved in the decline of T cell responses in immunosenescence.

Adult↗
PubMed2006

Toll-like receptor 4 polymorphism is associated with coronary stenosis but not with the occurrence of acute or old myocardial infarctions.

OBJECTIVE: Atherosclerosis is considered to be a chronic inflammatory disease. Toll-like receptor 4 (TLR-4), a key mediator in activating inflammatory cascade, has an A-to-G functional polymorphism that changes aspartic acid to glycine at position 299. TLR-4 is activated by, for example, lipopolysaccharides. The purpose of this study was to investigate the role of a common Asp299Gly polymorphism of the TLR-4 gene in atherosclerosis. MATERIAL AND METHODS: The study comprised autopsy material from 657 men (the Helsinki Sudden Death Study; mean age 53, range 33-70 years). RESULTS: Fewer G-allele carriers had 3-vessel coronary artery disease compared with AA homozygotes (OR 0.32; 95 % CI, 0.12-0.88, p = 0.027), and they also had a lower mean value for maximal coronary stenosis (p = 0.019). TLR-4 polymorphism was not significantly associated with the occurrence of acute or old myocardial infarction (MI). CONCLUSIONS: The G allele of the TLR-4 gene, which is associated with a lower inflammation response, was associated with a lower risk of coronary stenosis but not with the occurrence of MI and hence is not a major factor in the development of coronary atherosclerosis.

Acute Disease↗
PubMed2006

Radiographic assessment of dental health in middle-aged men following sudden cardiac death.

Poor oral health has been suggested to be a risk factor for myocardial infarction. To study if dental pathology might predispose to pre-hospital sudden cardiac death, and using a sum index of panoramic tomography findings, we compared the oral health of middle-aged (33-69 yrs) male victims (Helsinki Sudden Death Study) of sudden cardiac death (n = 117) with that of controls, who died of non-cardiac diseases (n = 63) or suffered unnatural sudden death (n = 120). The mean number of teeth was 15.2, and 17.4% of the men were edentulous. Frequent age-associated findings in dentate victims were fillings (79.9%), horizontal bone loss (72.1%), periapical lesions (45.6%), residual roots (38.2%), and vertical pockets (30.9%). In multivariate analysis with coronary heart disease risk factors and number of teeth as covariates, poor oral health was associated (p = 0.053) with the risk of sudden cardiac death along with age, smoking, and body mass index. This association was especially strong (p = 0.009) among victims < 50 yrs.

Adult↗
PubMed2005

Interleukin-6 -174G/C polymorphism and longevity: a follow-up study.

Increased rate of inflammation has been observed to be associated with aging. This is manifested, e.g. as increased blood levels of proinflammatory cytokines, such as interleukin-6 (IL-6). The production of IL-6 is, at least partially, genetically determined the single nucleotide polymorphism (SNP) at the promoter (-174G/C) being decisive. Consequently, some studies have demonstrated that the -174G/C genotype frequencies are different in very old persons as compared to younger ones. However, the results published this far have been conflicting. One of the main confounding factors in these kind of case/control association studies is the undetected difference in the population structure. To avoid this, we now have collected the mortality data of our cohort of 285 nonagenarians (representing mortality between 90 and 95 years of age) and correlated these to the IL-6 genotype. The frequency of -174 allele G was clearly higher in the survivors (n = 114) than in the non-survivors (n = 171).

Aged↗
PubMed2005

Identification of different bacterial DNAs in human coronary arteries.

BACKGROUND: Various studies have suggested a link between infection, atherosclerosis and coronary artery disease. We studied whether bacterial DNA is present in coronary specimens obtained from left anterior descending coronary arteries of subjects having sudden deaths of cardiovascular and other causes, as verified by an autopsy. MATERIALS AND METHODS: Coronary specimens were obtained from five subjects who died of sudden coronary causes and five controls. Broad-range 16-s rDNA PCR (Br-PCR) amplification, cloning and sequencing were used to detect bacterial rDNA. RESULTS: Bacterial rDNA sequences of oral pathogens were detected from the coronary samples in all cases regardless of the cause of death. CONCLUSIONS: Br-PCR is a powerful method to detect bacterial rDNA. By this method we were able to detect wide palette of oral bacteria from coronary tissues. Our findings suggest that atheromas may act as mechanical sieves collecting bacteria from the circulation.

Adult↗
PubMed2003

Fibrinogen gene promoter -455 A allele as a risk factor for lacunar stroke.

BACKGROUND AND PURPOSE: Elevated fibrinogen levels are suggested to increase the risk of myocardial infarction and stroke. Carriers of the A allele of the fibrinogen -455G/A polymorphism have increased plasma fibrinogen levels. We studied the association of this polymorphism with stroke subtype in the Stroke Aging Memory (SAM) cohort. METHODS: The SAM cohort comprises 486 consecutive patients 55 to 85 years of age who, 3 months after ischemic stroke, completed a detailed stroke assessment. Stroke subtypes were examined with MRI. -455G/A genotype was determined by polymerase chain reaction. MRI and genotype data were available for the 299 patients who constitute the present study population. RESULTS: Genotype distributions were 64.9% (GG), 31.8% (GA), and 3.3% (AA). In a logistic regression model with age, sex, hypertension, diabetes, hypercholesterolemia, hypertriglyceridemia, myocardial infarction, arrhythmia, atrial fibrillation, peripheral arterial disease, and smoking as possible confounders, there was a significant association between A+ genotype and >or=3 lacunar infarcts (odds ratio [OR], 2.57; 95% CI, 1.23 to 5.36; P=0.01). Hypertensive patients carrying the A allele had increased risk (OR, 4.24; 95% CI, 1.29 to 13.99; P=0.02) for >or=3 lacunar infarcts. A similar increase in risk was observed among smokers with the A+ genotype (OR, 2.67; 95% CI, 0.92 to 7.77; P=0.07). CONCLUSIONS: Stroke patients carrying the A allele of the Bbeta-fibrinogen -455G/A polymorphism frequently presented with multiple lacunar infarcts. This association was stronger among hypertensives and smokers. These associations suggest that the A allele may predispose to atherothrombotic events in cerebrovascular circulation.

Aged↗
PubMed2003

Do temporal arteritis lesions contain bacterial DNA?

BACKGROUND: Temporal arteritis is a primary vascular inflammatory disease. The aetiology of temporal arteritis is unknown, but the influence of environmental factors such as infections has been suggested. MATERIALS AND METHODS: We used broad-range PCR, targeting conserved regions of the gene encoding for ribosomal RNA, to detect bacterial DNA in 27 temporal artery biopsies. Five uninvolved temporal arteries were also included. A lung sample of confirmed bacterial pneumonia served as a positive control. Inflammation was examined by histochemistry and light microscopy. RESULTS: The sensitivity of the broad-range PCR assay was 5.0 fg of DNA. Bacterial DNA sequences were neither detected in 27 temporal arteritis specimens nor in the normal temporal artery samples. However, bacterial DNA was successfully amplified from the lung sample of a subject with pneumonia. In addition, human DNA was amplified by primers for human beta-actin from all clinical specimens, suggesting lack of significant inhibitors of the molecular amplification reaction. Histochemistry showed signs of strong inflammation in the arteritis samples. CONCLUSIONS: The lack of detectable amounts of bacterial DNA suggests that viable bacteria do not have a role in chronic stages of temporal arteritis. However, these findings do not rule out the possibility of bacterial degradation products as stimulants of chronic inflammation, or of viable microbes as triggering factors of acute temporal arteritis.

Aged↗
PubMed2003

A functional variant of the iNOS gene flanking region is associated with LAD coronary artery disease: an autopsy study.

BACKGROUND: Recent studies using reporter gene constructs have indicated significant differences in the promoter activity of inducible nitric oxide synthase (iNOS) gene variants. Although the exact role of iNOS in atherogenesis is unclear, it is possible that this variation site may influence the extent of coronary artery disease (CAD). METHODS: We amplified these (AAAT) repeat variants from the NOS2A gene (denoted iNOS R4 and iNOS R5) from 325 Finnish men included in the Helsinki Sudden Death Study, and studied their association with indices of stenosis and atherosclerosis of the left anterior descending artery (LAD), right coronary artery (RCA) and left circumflex artery (LCX). In order to understand the effect of iNOS genotype on different stages of CAD, our study population was divided into age groups. RESULTS: In the LAD, the progression of atherosclerosis seemed to be more pronounced in the 4/5 genotype carriers than in those with the 4/4 genotype when the different age groups were compared. More specifically, statistically significant differences between the genotypes were found in the subgroup of men aged > 55 years. In this group, men carrying the rare R4/5 genotype presented higher mean values of stenosis percentages (55% vs. 42%, P = 0.008), larger areas of fatty streaks (10.4% vs. 5.9%; P = 0.01) and complicated lesions (3.5% vs. 1.3%; P = 0.001) compared with the R4/4 carriers. No significant association of iNOS genotypes with stenosis and atherosclerosis of RCA and LCX was found. CONCLUSIONS: It appears unlikely the R4/5 genotype plays a major role in the pathogenesis of CAD, as it was not associated with stenosis and atherosclerosis in RCA and LCX. However this genotype may have some role in more pronounced CAD, as seen in the LAD.

Adult↗
PubMed2001

Platelet glycoprotein Ibalpha HPA-2 Met/VNTR B haplotype as a genetic predictor of myocardial infarction and sudden cardiac death.

BACKGROUND: Sudden cardiac death (SCD) is one of the leading manifestations of coronary heart disease in early middle age. Platelet glycoprotein (GP) Ib-IX-V receptor complexes play a key role in the initial adhesion of platelets to collagen during the formation of a coronary thrombus. The HPA-2 (Thr145 Met) and VNTR polymorphisms of the gene for GP Ibalpha have been studied previously in hospitalized patients with acute coronary syndromes. The significance of these polymorphisms in victims of sudden cardiac death is not known. METHODS AND RESULTS: The association of these 2 polymorphisms with coronary atherosclerosis, coronary artery stenosis, coronary thrombosis, myocardial infarction (MI), and SCD was studied in the Helsinki Sudden Death Study, which comprised 2 large autopsy series, collected 10 years apart during 1981 to 1982 and 1991 to 1992, of 700 middle-aged white Finnish men who suffered sudden or violent out-of-hospital death. The 2 polymorphisms showed an almost complete linkage disequilibrium. Men with acute MI (n=80) and coronary thrombosis (n=65) were more likely to be carriers of the HPA-2 Met allele (OR 2.0 and 2.6, respectively, P<0.005 for both) than were control subjects who died of noncardiac causes (n=367). In men <55 years old, the Met allele was overrepresented (OR 2.2) among victims of SCD (n=98) compared with control subjects (n=249). In men <55 years old, 17 of 29 men with acute MI (58.6%) and 16 of 23 men with coronary thrombosis (69.6%) were carriers of the HPA-2 Met allele compared with the 49 of 249 (19.7%) who had died of noncardiac causes (ORs 5.6 and 9.2, respectively). Similar associations were observed in the separate analyses of both autopsy series. CONCLUSIONS: Our results suggest that the HPA-2 Met/VNTR B haplotype of the platelet von Willebrand factor and thrombin receptor protein GP Ib-V-IX may be considered to be a major risk factor of coronary thrombosis, fatal MI, and SCD in early middle age.

Adult↗
PubMed2001

Polymorphisms within the tumor necrosis factor locus and prevalence of coronary artery disease in middle-aged men.

Tumor necrosis factor (TNF) is an important cytokine in the inflammation process of atherosclerosis and is also involved in lipid metabolism. Two biallelic polymorphisms within TNF gene locus-TNFA at the position -308 in the promoter region of the TNF gene and TNFB in the first intron of the lymphotoxin-alpha (LT-alpha) have been reported to be associated with TNF production and with susceptibility to inflammatory diseases. We studied the association of these polymorphisms within the major histocompatibility complex (MHC) III region with coronary atherosclerosis and its manifestations. The autopsy series comprised 700 Caucasian Finnish men, aged 33-70 years (The Helsinki Sudden Death Study). Coronary stenosis and surface area of atherosclerotic changes (fatty streaks, fibrous plaques, complicated lesions and calcification) were measured and the presence of myocardial infarction and coronary thrombosis recorded. TNFA and TNFB genotypes were determined by the PCR-RFLP technique. The allele frequencies were TNFA1/TNFA2=0.88/0.12 and TNFB1/TNFB2=0.30/0.70. There was a strong linkage disequilibrium between the two polymorphisms. There were no differences in coronary stenosis and in the frequency of old or recent myocardial infarction or coronary thrombosis between men with different genotype status in either locus. Men with TNFA22 or TNFB11 genotype tended to have more fibrous lesions and calcification in their coronary arteries. TNFA and TNFB polymorphisms are unlikely to contribute to progression of atherosclerosis in a way clinically important.

Adult↗
PubMed2001

The GPIIIa (beta3 integrin) PlA polymorphism in the early development of coronary atherosclerosis.

The GPIIIa (beta3 integrin) is an integral part of two glycoprotein receptors - the GP(IIb/IIIa) fibrinogen receptors in platelets and the GP(V/IIIa) vitronectin receptors in endothelium and vascular smooth muscle cells (vSMC). The PlA polymorphism of the gene for GPIIIa (beta3 integrin) has been suggested to play an important role in the progression of coronary artery disease (CAD) and in coronary thrombosis. Whether the action of the PlA polymorphism is due to differences in platelet aggregability or function of the vSMC and endothelial GPIIIa is not known. The association of the PlA polymorphism with the early, non-complicated atherosclerosis and CAD was studied in the Helsinki Sudden Death Study (HSDS) comprising two independent, autopsy series of altogether 700 middle-aged Caucasian Finnish men (33-70 year) suffering sudden out-of-hospital death. The burden of complicated lesions was greater in men with the A2 allele (heterozygotes or homozygotes for A2) (P=0.01) compared with PlA1/A1 homozygotes in the entire series. To further estimate the role of platelet-independent GPIIIa receptors, we excluded all cases with coronary thrombosis and thrombus-overlaid complicated lesions. In this subset of men, fibrous coronary lesions were more frequent (OR 2.9; P<0.01) in the coronary arteries of PlA1/A1 homozygotes compared with men with the PlA2 allele. Moreover, men with the PlA1/A1 genotype also had more stenotic coronary arteries (P<0.05) compared with men with the A2 allele at this early, non-complicated stage of atherosclerosis. The findings of this study suggest that Pl(A1/A1) homozygotes may be prone to early atherosclerosis and more rapid progression of stable CAD whereas carriers of the PlA2 allele are more prone to thrombotic complications. We hypothesize that the PlA polymorphism may account for the early atherosclerosis by affecting the function of endothelial and vSMC GP(V/IIIa) receptors, whereas the PlA polymorphism on platelet GP(IIb/IIIa) receptors may play a major role in coronary thrombosis.

Adult↗
PubMed2001

Promoter polymorphism of the CD14 endotoxin receptor gene as a risk factor for alcoholic liver disease.

Twin concordance studies indicate that genetic factors influence the individual susceptibility for alcoholic liver disease (ALD). Both clinical and experimental data suggest that Kupffer cell activation by gut-derived endotoxins and other bacterial products is an important pathogenic factor. Activated Kupffer cells release proinflammatory cytokines, a process that is regulated by the CD14 endotoxin receptor (CD14). Recently, a C-->T (-159) polymorphism in the promoter region of the CD14 gene was detected and found to confer increased CD14 expression. In the present study, the association of CD14 promoter polymorphism with different forms of ALD was examined in 3 separate autopsy series. Among 442 men with valid alcohol-consumption data, 381 men had been moderate or heavy alcohol consumers. The allele frequency of the CD14 promoter genotype, determined by a modified cycle minisequencing technique, was 0.34 (CC), 0.51 (CT), and 0.16 (TT). The T allele was found to be associated with advanced ALD, i.e., with alcoholic hepatitis (odds ratio [OR]: 2.48; P = .018), and especially with cirrhosis (OR: 3.45; P = .004), but not with fatty liver, periportal fibrosis, or bridging fibrosis. The overall age-adjusted risk for cirrhosis was 3.08 (P = .01) for the carriers of the CT genotype, and 4.17 (P = .005) for the homozygous TT genotype. These results suggest that in the relatively isolated Finnish population, the T allele confers increased risk of alcoholic liver damage. In particular, TT homozygotes are at a high risk to develop cirrhosis.

Adult↗
PubMed2001

Prominent mitochondrial DNA recombination intermediates in human heart muscle.

Recombination intermediates containing four-way (Holliday) junctions are generated during DNA repair and replication in many systems, including yeast mitochondrial DNA (mtDNA). In contrast, convincing evidence for recombination in mammalian mtDNA is lacking. We have used two-dimensional agarose-gel electrophoresis to analyse non-linear forms of mtDNA in human heart muscle. Replication intermediates from both the coupled and strand-asynchronous mtDNA replication pathways were detected. An additional class of non-linear molecules, with the electrophoretic properties of four-way junctions, was also prominent. These molecules were insensitive to topoisomerase I or RNase H, but were diminished by branch migration or RuvC treatment. Junctional molecules were detected in all regions of the mitochondrial genome, were found in myocardial DNA from young and old adults, but were present at lower levels in skeletal muscle and placenta. We suggest that they could represent intermediates of mtDNA repair, given their prevalence in the oxyradical-rich environment of heart muscle mitochondria.

Blotting, Southern↗
PubMed2001

Testing genetic susceptibility loci for alcoholic heart muscle disease.

BACKGROUND: Although many heavy alcohol users have subclinical alcoholic heart muscle disease, only a very few develop severe dilated cardiomyopathy. Therefore, and because cardiac abnormalities correlate only weakly with the duration or quantity of drinking, individual susceptibility differences may exist. In this work we examined whether common gene variants previously associated with cardiac hypertrophy or altered alcohol metabolism could modify the effects of alcohol on the heart. METHODS: We studied 700 middle-aged male victims of sudden death who underwent a medicolegal autopsy. In addition to routine postmortem examination, the weights and the cavity and wall dimensions of the left and right ventricle were measured. Coronary artery stenoses were determined from a silicone rubber cast of the arteries. Alcohol consumption and cardiovascular risk factors were assessed by a structured interview of the spouse. The following gene polymorphisms were determined by using polymerase chain reaction restriction fragment length polymorphism and solid-phase minisequencing techniques: angiotensin converting enzyme I/D, angiotensin II type 1 receptor 1166A/C, aldosterone synthase -344C/T, alcohol dehydrogenases 2 and 3, acetaldehyde dehydrogenase 2, and cytochrome P-450 2E1 DraI, PstI, RsaI, and MspI. RESULTS: The most consistent effects of alcohol (p < 0.05) were a higher total heart weight and a larger right ventricle size with increasing daily drinking. However, these and other effects of alcohol were statistically fully independent of the studied genotypes. CONCLUSIONS: The gene polymorphisms selected for and analyzed in our study are unlikely to modify the effects of alcohol on the heart. Other unknown factors determine the individual susceptibility to alcoholic heart muscle disease.

Adult↗
PubMed2001

Association of neuropeptide y polymorphism with the occurrence of type 1 and type 2 alcoholism.

BACKGROUND: The susceptibility to alcoholism can be explained partially by genetic factors. Neuropeptide Y (NPY) has emerged as one potential factor contributing the development of alcoholism. A recent study indicated that the NPY gene variant producing a leucine-to-proline substitution (T to C at position 1128) was associated with 34% higher average alcohol consumption. METHODS: The subjects consisted of 122 alcoholics classified as type 1 and type 2 subtypes by psychiatric evaluation. A random sample of 59 social drinkers was used as a control group to compare the distribution of NPY genotypes with those of alcoholics. RESULTS: In a logistical regression model, there was a significantly lower frequency of the leucine(7)/proline(7) heterozygotes among well characterized type 2 alcoholics, compared with the controls (10.8 vs. 24.1%, p = 0.028). CONCLUSIONS: We speculate that the genetic polymorphism producing the proline(7) substitution of NPY might not predispose to alcoholism, but indeed retard the transition to alcoholism.

Adult↗
PubMed2001

Dose dependent but non-linear effects of alcohol on the left and right ventricle.

OBJECTIVE: To assess how left (LV) and right ventricular (RV) size, wall thickness, and mass depend on daily alcohol consumption. Among alcoholics, most common findings have been LV hypertrophy and mild systolic or diastolic dysfunction, accompanied occasionally by ventricular dilatation resembling dilated cardiomyopathy. Although it is commonly agreed that chronic heavy alcohol use is injurious to the heart, the dose-injury relation remains a matter of dispute. DESIGN: Prospective series of 700 Finnish men aged 33-70 years who died out of hospital and underwent a medicolegal necropsy. METHODS AND RESULTS: Data on alcohol use and other risk factors were obtained from the spouse. At necropsy, a transversal slice of the heart was traced on a transparent sheet and analysed later for LV and RV cavity areas and wall thicknesses. Coronary artery stenoses were measured from silicone casts of the arteries. In analyses of all men, daily alcohol dose predicted heart weight (beta = 0.17, p < 0.001) and RV cavity area (beta = 0.14, p = 0.007) independent of body size, age, coronary artery disease, hypertension, diabetes, and smoking. In the subgroup of men free of significant coronary artery disease, LV area averaged (SEM) 11.0 (1.0) cm(2) in men drinking < 12 g/day, 7.7 (0.7) cm(2) in those drinking 72-180 g/day, and 10.0 (0.9) cm(2) in those drinking > 180 g/day (p = 0.054). Very heavy drinking (> 180 g/day) was associated with an increase in RV cavity area (p = 0.005). CONCLUSIONS: The effects of alcohol on the heart in middle aged men are dose dependent but partly non-linear. In the absence of coronary artery disease, LV size shows a U shaped reduction with increasing daily alcohol use accompanied by an increase in RV size with very heavy drinking. These findings question the idea of progressive LV dilatation with increasing alcohol consumption among male victims of sudden death.

Adult↗
PubMed2001

Association of apolipoprotein E polymorphism with outcome after aneurysmal subarachnoid hemorrhage: a preliminary study.

BACKGROUND AND PURPOSE: Variation in the outcome after aneurysmal subarachnoid hemorrhage (SAH) is not fully explained by known prognostic factors. APOE genotype is the most important genetic determinant of susceptibility to Alzheimer's disease, and it is also shown to be associated with the outcome after traumatic brain injury. We studied the association of apolipoprotein E polymorphism with the outcome after aneurysmal SAH. METHODS: A total of 160 consecutive patients were admitted after SAH to a neurosurgical unit. The clinical assessment after the SAH was performed with the Hunt and Hess grading scale. The severity of the bleeding as visualized on CT was assessed by Fisher's grading system. Outcome was assessed with the Glasgow Outcome SCALE: APOE genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: 126 patients had aneurysmatic SAH, and detailed information on outcome and APOE genotype was available for 108 patients (86%). Sixteen (40%) of 40 patients with APOE epsilon4 had an unfavorable outcome compared with 13 (19%) of 68 without the APOE epsilon4 allele (OR 2.8, 95% CI 1.18 to 6.77). Association was more significant after adjustment for age, rebleeding, clinical status on admission, and CT scan findings (OR 7.1, 95% CI 1.9 to 26.3; P=0.0035). CONCLUSIONS: Our findings show a significant genetic association of APOE polymorphism with outcome after spontaneous aneurysmal SAH. Genetic factors thus seem to explain a part of individual differences in the recovery of SAH.

Apolipoproteins E↗