Hematocrit and the risk of coronary heart disease mortality in the TAMRISK study, a 28-year follow-up.

OBJECTIVE: To evaluate whether hematocrit (HCT) is associated with coronary heart disease (CHD) mortality in men over 55 years of age in Finland. METHODS: Health survey data were recorded in 1980 from 670 men, aged 55 years. The causes of deaths during a 28-year follow-up were obtained from official records. Statistical comparisons were done by Cox proportional hazard regression model after dividing the men into two groups, one with HCT<50% and the other, HCT> or =50%. RESULTS: There were altogether 412 deaths of all causes, including 140 from CHD. In men having HCT<50%, the crude CHD mortality rate per 10,000 population was 2203, while in men with HCT> or =50%, the corresponding figure was 4255. Men with HCT> or =50% were 2.4 times (95% CI 1.6-3.5) more likely to die from CHD than were men with HCT<50%. After adjusting for established coronary risk factors, the increased risk remained 1.8-fold (95 % CI, 1.1-2.7). CONCLUSIONS: Borderline polycythemia was associated with increased CHD mortality. The cut-off value in our study was > or =50%, proposing that for men over 55 years of age such HCT levels might be an additional risk factor.

Serum matrix metalloproteinase-9 and venous bypass graft occlusion.

OBJECTIVE: The primary results after coronary artery bypass grafting are good, but early clinical events as a result of graft occlusion are still a problem. Early occlusions are thought to be due to thrombosis or fibrointimal hyperplasia superimposed by thrombosis, but the etiology of these phenomena is not fully understood. Matrix metalloproteinase-9 has been suggested to have a role in graft occlusion ex vivo. MATERIAL AND METHODS: We investigated whether the level of serum matrix metalloproteinase-9 reflects its proposed role in occlusion of vein grafts. The study population consisted of 30 men with a history of myocardial infarction and 31 men without myocardial infarction who had undergone coronary artery bypass grafting. All the men were asymptomatic. RESULTS: Among the patients with no previous myocardial infarction, serum matrix metalloproteinase-9 level was significantly higher in those with graft occlusion than in those without occlusion (54.0+/-11.0 microg/L and 41.7+/-10.4 microg/L, respectively, p = 0.006), and it correlated positively with the number of occluded grafts (R = 0.55, p = 0.001). In the patients with myocardial infarction, this effect was not detected. CONCLUSIONS: Serum matrix metalloproteinase-9 reflected the occurrence of vein graft occlusion in subjects with no previous history of myocardial infarction.

Serum matrix metalloproteinase-9 is elevated in men with a history of myocardial infarction.

Elevated serum inflammatory markers have been reported in coronary heart disease. Levels of serum matrix metalloproteinase-9 (MMP-9), C-reactive protein (CRP), C3-complement (C3) and autoantibodies against oxidized low-density lipoprotein (oxLDL) in 120 male subjects with a history of myocardial infarction (MI) were compared with those in 250 age-matched controls, both groups from a large cross-sectional population survey, the FINRISK study. The concentrations of serum MMP-9 and autoantibodies against oxLDL were measured by enzyme-linked immunosorbent assay, CRP and C3 by immunonephelometry. MMP-9, CRP and C3 concentrations were higher in the subjects with a history of MI than in the controls (p=0.037, p=0.004, and p=0.006, respectively). There was no difference between the groups in serum levels of autoantibodies against oxLDL. In other background characteristics, men in the MI group had higher body mass index (BMI) and serum triglyceride values and lower serum HDL cholesterol values compared to controls (p=0.009, p=0.001, and p<0.001, respectively). When analyzed by stepwise multiple logistic regression using BMI, HDL cholesterol, triglycerides, CRP, C3 and MMP-9 as independent variables, the significant predictors for MI were HDL cholesterol (p=0.002) and MMP-9 (p=0.015). These results suggest that increased serum MMP-9 may reflect inflammatory pathologic processes that are related to progression of atherosclerosis.

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.

Serum matrix metalloproteinase-9 concentration in angiographically assessed coronary artery disease.

Expression of several matrix metalloproteinases (MMPs) in atherosclerotic plaques has been well documented, and there are findings to indicate that arterial inflammation is reflected in increased serum concentration of matrix metalloproteinase-9 (MMP-9). In coronary atherosclerosis, there is enhanced expression of this MMP, which may be predictive of the severity of the disease. We determined the concentrations of serum MMP-9 in 61 patients (47 males, 14 females) who had >50% obstruction in one or more coronary arteries as assessed by coronary angiography before bypass surgery. In a control group of 19 patients (9 males, 10 females) there were no pathological findings in coronary angiography. ANOVA showed that serum MMP-9 concentrations were highest in patients with 3-vessel coronary artery disease (CAD) (57.3+/-39.1 microg/L, p=0.011). The difference remained statistically significant after adjustment for age, diabetes and sex (p=0.025, ANCOVA). When the groups were compared with each other, serum MMP-9 concentration was higher in the patients with 3-vessel CAD than in those with 1- or 2-vessel CAD (40.4+/-25.1 microg/L, p=0.044) or in the controls (32.2+/- 16.1 microg/L, p=0.007). These results show that serum MMP-9 is elevated in patients with severe coronary stenosis compared with controls. Since MMP-9 has been suggested to reflect inflammation in atherosclerotic plaques, it may be useful in the evaluation of the severity of cardiovascular disease.

Matrix metalloproteinase-9 is elevated in serum of alcohol abusers.

BACKGROUND: Moderate alcohol consumption has been shown to protect against coronary heart disease. However, excessive alcohol use has been suggested to have detrimental effects on the cardiovascular system. We examined whether there is an association between alcohol abuse and circulating levels of matrix metalloproteinase-9 (MMP-9), which has been linked to unstable coronary heart disease and arterial inflammation. DESIGN: Serum MMP-9 concentrations were compared between 40 male alcoholics (mean age 42 years) with ethanol consumption > 1000 g week(-1) and 40 social drinker males with an ethanol consumption of < 200 g week(-1) (mean age 45 years). RESULTS: The mean serum MMP-9 concentration was significantly higher in sera of alcoholics compared to control subjects (70.9 +/- 47.7 g L(-1) and 43.1 +/- 19.2 g L(-1), respectively; P = 0.001). Within the alcoholic group, MMP-9 concentration did not correlate with age, gamma glutamyl transferase, carbohydrate-deficient transferrin, aspartate aminotransferase, alanine aminotransferase or alkaline phosphatase. CONCLUSION: Our finding of elevated MMP-9 concentrations in sera of chronic alcohol abusers helps understand the mechanisms of cardiovascular risk among these subjects.

Association of serum MMP-9 with autoantibodies against oxidized LDL.

Monocyte-derived macrophages in atherosclerotic plaques secrete matrix metalloproteinases (MMPs), which may contribute to plaque rupture. There has been much speculation as to which factors precipitate in the arterial inflammation. Oxidized low density lipoprotein (oxLDL) has been suggested to have proinflammatory properties, and it has been shown to increase matrix metalloproteinase-9 (MMP-9) secretion by macrophages in vitro. We determined serum MMP-9 concentration and autoantibodies against oxLDL by ELISA in men with angina pectoris (n=243) and age-matched controls (n=238). The association between serum MMP-9 concentration and autoantibodies against oxLDL was evaluated. Autoantibody level against oxLDL, expressed in optical density units, was significantly higher in subjects with angina pectoris compared to controls (0.100+/-0.064 versus 0.088+/-0.051, respectively, P=0.030), but serum levels of MMP-9 did not differ significantly between these groups (54.2+/-29.9 versus 50.6+/-23.1 microg/l). However, autoantibodies against oxLDL correlated positively with serum MMP-9 (r=0.21, P<0.001). In a multiple regression model (including age, diastolic blood pressure, cholesterol, HDL cholesterol, triglycerides, BMI, smoking and MMP-9) serum MMP-9 (beta=0.200, P<0.001) and smoking (beta=0.179, P<0.001) were significantly associated with autoantibodies against oxLDL. In conclusion, autoantibodies against oxLDL were positively associated with angina pectoris and serum MMP-9. Since autoantibody level against oxLDL could be expected to reflect the degree of oxLDL in the vessel wall, our results suggest that oxLDL is associated with MMP-9 in vivo.

Effect of pravastatin in mildly hypercholesterolemic young men on serum matrix metalloproteinases.

Pravastatin decreases serum MMP-9 concentration in clinically healthy men. This may reflect reduction of nonsymptomatic chronic arterial inflammation.

Serum homocysteine does not associate with uncomplicated coronary heart disease.

BACKGROUND: Elevated serum homocysteine concentrations have been related to coronary heart disease. However, the association has not indisputably been proven, and the mechanisms by which homocysteine may be atherogenic have only partially been elucidated. The objective of the present study was to investigate whether serum homocysteine is associated with angina pectoris and myocardial infarction. METHODS: We compared serum homocysteine concentrations in subjects with clinical evidence of angina pectoris or history of myocardial infarction to age-matched controls. The study included 248 males, who participated in a large cross-sectional risk factor survey carried out in five geographic areas in Finland. RESULTS: Serum homocysteine concentration was significantly higher in subjects with a history of myocardial infarction compared to controls (15.3 micromol L-1 and 13.9 micromol L-1 respectively, P = 0.037). In a logistic regression model including several cardiovascular risk factors, serum homocysteine was significantly associated with myocardial infarction (95% CI 1.0157-1.2990, P = 0.027). Serum homocysteine concentrations did not differ between subjects with angina pectoris and age-matched controls (13.9 micromol L-1 and 14.2 micromol L-1 respectively). CONCLUSIONS: Our results suggest that elevated serum homocysteine is associated with myocardial infarction but not with uncomplicated coronary heart disease.

Association of carbohydrate-deficient transferrin (CDT) and gamma-glutamyl-transferase (GGT) with serum lipid profile in the Finnish population.

BACKGROUND: Moderate consumption of alcohol may reduce mortality from vascular diseases. The beneficial effects of alcohol may partly be mediated by its effects on lipoprotein metabolism. We studied the connection between alcohol consumption and the serum lipid profile from a well-documented national health program study. METHODS AND RESULTS: Carbohydrate-deficient transferrin (CDT) and gamma-glutamyl-transferase (GGT) were used as biochemical markers for alcohol consumption. The laboratory analyses were carried out on 5675 subjects (3097 males and 2578 females). The subjects were divided into quartiles on the basis of CDT or GGT value. The highest CDT quartile and the lowest GGT quartile seemed to be associated with a favorable lipid profile and the lowest CDT quartile and the highest GGT quartile were associated with an unfavorable lipid profile. Serum high density lipoprotein (HDL) cholesterol values were significantly higher and triglycerides lower with increasing serum CDT concentrations for both men and women. Increasing serum GGT was associated with higher serum total cholesterol and higher triglycerides in both men and women and lower HDL cholesterol in men. CONCLUSIONS: CDT and GGT seem to detect different populations of subjects in regard to lipid metabolism. These observations may lead to a better understanding of the effects of alcohol consumption on lipids as well as mechanisms behind favorable and detrimental effects of alcohol on vascular diseases. CONDENSED ABSTRACT: Carbohydrate-deficient transferrin (CDT) and gamma-glutamyl-transferase (GGT) were used as biochemical markers for alcohol consumption. A total of 3097 males and 2578 females were divided into quartiles on the basis of their CDT or GGT values. The highest CDT quartiles had higher HDL and lower triglycerides, whereas the highest GGT quartiles appeared to be associated with higher total cholesterol and triglycerides in both genders and lower HDL in men. CDT and GGT seem to detect different populations of subjects in regard to lipid metabolism. These observations may have important clinical and public health implications.

Association of serum sialic acid and MMP-9 with lipids and inflammatory markers.

BACKGROUND: Inflammation of the arterial wall has emerged to be an important contributor to the process of atherosclerosis, the major cause of coronary heart disease. Several factors are currently under investigation as inflammatory markers of atherosclerosis. Serum sialic acid and matrix metalloproteinase-9 may provide such markers. We studied their association with the lipid profile and with the inflammatory markers C-reactive protein and leukocyte count in a clinically healthy population of men. MATERIALS AND METHODS: Cardiovascular risk-related laboratory tests were carried out in 65 consecutive male employees in connection with an occupational health survey in 1996. The subjects were divided into tertiles on the basis of serum sialic acid or matrix metalloproteinase-9 concentration. RESULTS: In a stepwise polychotomous logistic regression model adjusting for coronary heart disease risk factors, serum sialic acid concentration was not associated with markers of inflammation but rather with the lipid risk factors of atherosclerosis: inversely with HDL cholesterol (OR = 0.081, 95% CI 0.0068-0.97) and positively with total cholesterol (OR = 2.4, 95% CI 1-5.6). Matrix metalloproteinase-9 levels had a significant positive correlation with the leukocyte count (OR = 2.3, 95% CI 1.4-4). CONCLUSIONS: Serum sialic acid does not appear to be an indicator of inflammation but is somehow connected with the level of total and HDL cholesterol. Serum matrix metalloproteinase-9 may provide a useful marker of inflammation because it correlates with the leukocyte count and is not associated with the lipid profile.

Intracellular route of canine parvovirus entry.

The present study was designed to investigate the endocytic pathway involved in canine parvovirus (CPV) infection. Reduced temperature (18 degrees C) or the microtubule-depolymerizing drug nocodazole was found to inhibit productive infection of canine A72 cells by CPV and caused CPV to be retained in cytoplasmic vesicles as indicated by immunofluorescence microscopy. Consistent with previously published results, these data indicate that CPV enters a host cell via an endocytic route and further suggest that microtubule-dependent delivery of CPV to late endosomes is required for productive infection. Cytoplasmic microinjection of CPV particles was used to circumvent the endocytosis and membrane fusion steps in the entry process. Microinjection experiments showed that CPV particles which were injected directly into the cytoplasm, thus avoiding the endocytic pathway, were unable to initiate progeny virus production. CPV treated at pH 5.0 prior to microinjection was unable to initiate virus production, showing that factors of the endocytic route other than low pH are necessary for the initiation of infection by CPV.

Characterization of a nuclear localization signal of canine parvovirus capsid proteins.

We investigated the abilities of synthetic peptides mimicking the potential nuclear localization signal of canine parvovirus (CPV) capsid proteins to translocate a carrier protein to the nucleus following microinjection into the cytoplasm of A72 cells. Possible nuclear localization sequences were chosen for synthesis from CPV capsid protein sequences (VP1, VP2) on the basis of the presence of clustered basic residues, which is a common theme in most of the previously identified targeting peptides. Nuclear targeting activity was found within the N-terminal residues 4-13 (PAKRARRGYK) of the VP1 capsid protein. While replacement of Arg10 with glycine did not affect the activity, replacement of Lys6, Arg7, or Arg9 with glycine abolished it. The targeting activity was found to residue in a cluster of basic residues, Lys5, Arg7, and Arg9. Nuclear import was saturated by excess of unlabelled peptide conjugates (showing that it was a receptor-mediated process). Transport into the nucleus was an energy-dependent and temperature-dependent process actively mediated by the nuclear pores and inhibited by wheat germ agglutinin.