Biomedical subjects

I Penttilä

Publications and source records attributed to I Penttilä.

At least 19 recordsLinked to original sources

PubMed2002

Relation of sex hormones to bone mineral density in middle-aged men during a 4 year exercise intervention trial.

Recent studies have emphasized the symbiotic role of estradiol and testosterone on bone metabolism. Several anthropomorphic-, lifestyle-, and dual-energy X-ray (DXA)-derived parameters were measured with respect to estradiol (E(2)), testosterone (T), free T (fT), and sex hormone-binding globulin (SHBG) in 140 men (aged 53-62 years) participating in a controlled, randomized exercise intervention trial. After 4 years of intervention, 132 (94.3%) men remained as participants. During the period of study, aerobic threshold increased significantly in the exercise intervention group compared with the reference group (13.4% vs. -1.9%: p < 0.023). Serum E(2) and fT were not convincingly related to bone mineral density (BMD) or BMD change. Aerobic threshold or the change in aerobic threshold were not associated with sex hormone or SHBG levels. Body mass index was a significant determinant of T (beta = -0.337), fT (beta = -0.293), and SHBG (beta = -0.306), and smoking predicted T (beta = 0.231) and fT (beta = 0.245). Alcohol intake was a significant determinant of E(2) (beta = 0.213). Ultimately there was no convincing relation between sex hormone levels and BMD or BMD change in middle-aged men.

Bone Density↗

PubMed2002

Serum and plasma as alternative sample types in analysis of cardiac markers in the clinical routine.

There is an increasing demand for the results of cardiac markers (troponin I or T, creatine kinase MB mass and myoglobin) to be made available promptly after sample-taking. In order to shorten the turnaround time, the possibility of using EDTA- or heparin-plasma instead of serum was investigated. The study population comprised 391 patients with acute chest pain. Four different instruments and systems routinely used in Finland giving quantitative results were studied for the assays of creatine kinase isoenzyme MB mass, myoglobin, and troponin I or troponin T. In addition to serum samples, heparin-plasma seems to be useful for all three assays using the Access and Immulite systems, while EDTA-plasma seems to be useful for all three assays with the Access and Elecsys systems. For the AxSYM assays, serum samples seem to be the best alternative. In conclusion, it is possible to use a single EDTA- or heparin-plasma sample for Access, Elecsys and Immulite analysers, and thereby to shorten the turnaround time. In this way the quantitative analyses from plasma can be performed 30 min after taking the sample.

Biomarkers↗

PubMed2001

Differences in the diagnosis of myocardial infarction by troponin T compared with clinical and epidemiologic criteria.

We investigated the difference in the number of myocardial infarction (MI) diagnoses based on troponin T compared with clinical and epidemiologic (modified FINnish Multinational MONItoring of trends and determinants in CArdiovascular diseases) diagnoses, and the prognosis of patients with discordant diagnoses. Five hundred fifty-nine consecutive patients (315 men and 244 women, median age 69 years) were admitted to the hospital with a suspected acute coronary syndrome. Median follow-up time was 17 months. Of the 559 patients, 127 had a clinical and 137 an epidemiologic diagnosis of MI. When a diagnosis of MI was primarily based on troponin T (>0.10 microg/L), the number of MIs was 169, which increased by 33% compared with the number of MIs by clinical diagnosis, and by 23% compared with those by epidemiologic diagnosis. However, troponin T was not elevated in 13% of the 127 patients with the clinical diagnosis and in 14% of the 137 patients with the epidemiologic diagnosis of MI. Among patients in whom clinical diagnosis of MI was not made, the prognosis with regard to coronary death or nonfatal MI was not significantly worse in patients with troponin T >0.10 microg/L than < or =0.10 microg/L (hazard ratio 1.07; 95% confidence interval 0.62 to 1.84). In patients with a suspected acute coronary syndrome, troponin T-based diagnostics leads to an increase in the number of patients diagnosed with MI compared with clinical or epidemiologic diagnosis. The prognostic impact of troponin T in patients without clinical diagnosis of MI based on elevations in conventional enzyme activities needs further study in larger series of patients.

Adult↗

PubMed2001

Effects of 50 Hz magnetic fields on cancer induced by ionizing radiation in mice.

PURPOSE: To evaluate the effects of 50 Hz magnetic fields (MF) on the development of cancer induced by ionizing radiation. MATERIALS AND METHODS: A total of 150 female CBA/S mice were randomized into three equal groups at the age of 3-5 weeks. One of the groups served as a 'cage-control group'. The two other groups were exposed to ionizing radiation in the beginning of the study. One of these two groups was exposed 24 h per day, for 1.5 years, to a 50Hz vertical MF, the intensity of which varied regularly between 1.3, 13 and 130 muT. The other served as a control group and was sham-exposed to MF in similar, but unenergized, exposure racks. Body weights, clinical signs, and food and water consumption were recorded regularly. Haematological examination, and the histopathological analysis of all lesions and major tissues were performed on all animals. RESULTS: MF exposure did not increase the incidence of any primary neoplasms. However, the incidence of basophilic liver foci, a probable pre-neoplastic change in liver, was increased. The incidence of hepatocellular adenomas was unchanged, whereas the incidence of hepatocellular carcinomas was slightly, but not statistically significantly, elevated. CONCLUSIONS: It is concluded that overall the results of this study do not support a role for MF as a tumour promoter.

Animals↗

PubMed2001

Ruling out myocardial infarction with troponin T and creatine kinase MB mass: diagnostic and prognostic aspects.

OBJECTIVE: To investigate the time window for ruling out myocardial infarction (MI) with troponin T (TnT) and creatine kinase isoenzyme MB mass (CK-MBm) and the prognosis of patients with ruled-out MI diagnosis. DESIGN: The study was based on 397 patients admitted with a suspected acute coronary syndrome but with relief of symptoms within 24 h. RESULTS: MI diagnosis was confirmed with elevated TnT (>0.10 microg/l) in 108 patients. in 91% within 12-24 h from the onset of symptoms, and in 99% within 12 h from admission. In 94 of these patients CK-MBm became elevated (>5.0 microg/l). in 95% within 10-12 h from the onset of symptoms, and in 99% within 6 h from admission. Among patients with ruled-out MI diagnosis, the 1-year incidence of recurrent coronary events was 29% in those with positive history of coronary heart disease (CHD) but only 7% in those without prior CHD (p < 0.001). CONCLUSION: Using TnT or CK-MBm, MI can be ruled out within 12 h from admission in the majority of patients. Among patients with ruled-out MI diagnosis, positive history of CHD is an important determinant of prognosis.

Adult↗

PubMed2001

Chlamydia pneumoniae does not increase atherosclerosis in the aortic root of apolipoprotein E-deficient mice.

In epidemiological studies, an association between cardiovascular disease and Chlamydia pneumoniae (C pneumoniae) infection has been observed. Although C pneumoniae has been shown to be present in atherosclerotic lesions, a causal relationship between C pneumoniae infection and atherosclerosis has not been demonstrated. To study this question, we used 2 strains of apolipoprotein (apo) E-deficient mice. Eight-week-old mice on an FVB background that were maintained on either a low- or a high-fat diet were infected 3 times at 1-week intervals with C pneumoniae, and atherosclerotic lesions were measured in the aortic root at 10 weeks after the primary infection. In each of the diet groups, no difference in the extent of atherosclerosis could be observed between the C pneumoniae-infected and control animals. In further studies, 2 strains of apoE-deficient mice (FVB or C57BL/6J background) were infected 4 times at 3- to 4-week intervals, and the extent of atherosclerosis was analyzed 18 weeks later. The mice were kept on either a low- or a high-fat diet. The high-fat diet increased atherosclerosis, and a difference in atherosclerosis susceptibility between the mouse strains was observed. However, C pneumoniae infection did not influence lesion size in either mouse strain. On the other hand, C pneumoniae could not be demonstrated by polymerase chain reaction in any of the atherosclerotic lesions of the infected animals studied. A small decrease in serum cholesterol and triglyceride levels 3 days after the primary infection occurred, but after that no differences in serum lipid levels compared with those in noninfected animals were evident. In the myocardium of C pneumoniae-infected mice, no inflammatory signs could be observed. We conclude that under the experimental conditions used, C pneumoniae infection does not accelerate atherogenic changes in the aortic root of apoE-deficient mice.

Animals↗

PubMed2000

Relationship between lipid peroxidation and plasma fibrinogen in middle-aged men.

The relationship between lipid peroxidation (plasma malondialdehyde [MDA] concentration) and plasma fibrinogen level was analyzed in 144 men, aged 53-62 years. MDA was measured colorimetrically and fibrinogen with the thrombin method. Mean plasma MDA concentration was 12.6 (SD 1.2) micromol/L, plasma fibrinogen level 2.91 (0.47) g/L, and body mass index 27.1 (3.5) kg/m(2). Prevalence of smoking was 17%. MDA correlated moderately with fibrinogen. Both MDA and fibrinogen correlated positively with waist hip ratio (WHR) and blood leukocyte count, but inversely with VO(2)max. Both MDA and fibrinogen levels were higher in smokers than in non-smokers (p<0. 01). In multiple stepwise regression analysis, plasma MDA, VO(2)max, smoking, and leukocyte count explained 38.1% of the variance in plasma fibrinogen level, with the individual contributions reaching 20.6%, 9.7%, 5.5%, and 2.3%, respectively. WHR, serum triglycerides, and age did not enter the model. These data suggest that increased lipid peroxidation is associated with elevated plasma fibrinogen level in middle-aged men.

Arteriosclerosis↗

PubMed2000

Adenosine with cold blood cardioplegia during coronary revascularization.

OBJECTIVE: To investigate whether adenosine in association with blood cardioplegia results in more rapid cardiac arrest or improved myocardial protection. DESIGN: A prospective, randomized, placebo-controlled double-blind clinical study. SETTING: Operative and intensive care units in a university hospital, Finland. PARTICIPANTS: Forty patients undergoing primary, elective coronary revascularization. INTERVENTION: Adenosine as a bolus dose, 12 mg intravenously, was given immediately before the induction of blood cardioplegia. MEASUREMENTS AND MAIN RESULTS: There were nonsignificantly higher serial serum values of CK (MB) (p = 0.33), troponin-T (p = 0.23), and troponin-I (p = 0.10) in the adenosine group. There were no differences between the groups in arrest time, blood pressure decrease, or lactate extraction. CONCLUSIONS: The adenosine regimen used in this study did not cause more rapid arrest with blood cardioplegia. The effect on cardioprotection was insignificant.

Adenosine↗

PubMed2000

Growth hormone and cortisol in serum and saliva.

Salivary diagnosis is a developing area in clinical chemistry and dentistry. Cortisol analyses from saliva have been used in pediatric practice and as doping tests. Growth hormone (hGH), also a stress hormone, has not been analyzed from saliva. We studied the serum and saliva of 51 healthy subjects. The samples were taken at 8:00 in the morning after 12 h fasting. Cortisol concentrations were analyzed using RIA. An immunoradiometric assay was applied for analyzing serum and salivary hGH. The validity of this method developed in our laboratory was found to be good. The results showed correlation of salivary cortisol with that of serum (r = 0.47, P < 0.001). Salivary hGH concentrations were 1000-fold lower than the respective values in serum, but a clear correlation was found between salivary and serum hGH levels (r = 0.59, P < 0.001).

Adult↗

PubMed2000

Laboratory diagnosis of patients with acute chest pain.

The enzyme activities of creatine kinase (CK), its isoenzyme MB (CK-MB) and of lactate dehydrogenase isoenzyme 1 (LD-1) have been used for years in diagnosing patients with chest pain in order to differentiate patients with acute myocardial infarction (AMI) from non-AMI patients. These methods are easy to perform as automated analyses, but they are not specific for cardiac muscle damage. During the early 90's the situation changed. First creatine kinase MB mass (CK-MB mass) replaced the measurement of CK-MB activity. Subsequently cardiac-specific proteins troponin T (cTnT) and troponin I (cTnI) appeared on the scene, displacing LD-1 analysis. However, troponin concentrations in blood increase only from four to six hours after onset of chest pain. Therefore a rapid marker such as myoglobin, fatty acid binding protein or glycogen phosphorylase BB could be used in early diagnosis of AMI. On the other hand, CK-MB isoforms alone may also be useful in rapid diagnosis of cardiac muscle damage. Myoglobin, CK-MB mass, cTnT and cTnI are nowadays widely used in diagnosing patients with acute chest pain. Myoglobin is not cardiac-specific and therefore requires supplementation with some other analyses such as troponins to support the myoglobin value. Troponins are very highly cardiac-specific. Only the sera of some patients with severe renal failure, which requires hemodialysis, have elevated cTnT and/or cTnI without there being any evidence of cardiac damage. On the other hand, the latest studies have shown that elevated troponin levels in sera of hemodialysis patients point to an increased risk of future cardiac events in a similar manner to the elevated troponin values in sera of patients with unstable angina pectoris. In addition, the bedside tests for cTnT and cTnI alone or together with myoglobin and CK-MB mass can be used instead of quantitative analyses in the diagnosis of patients with chest pain. These rapid tests are easy to perform and they do not require expensive instrumentation. For routine clinical laboratory practice we suggest that in diagnosis of patients with chest pain, myoglobin and CK-MB mass measurements should be performed whenever they are requested (24 h/day) and cTnT or cTnI on admission to the hospital and then 4-6 and 12 hours later.

Creatine Kinase↗

PubMed2000

Regulation of immunoreactive inhibin A and B secretion in cultured human granulosa-luteal cells by gonadotropins, activin A and insulin-like growth factor type-1 receptor.

Inhibins are gonadal glycoproteins with endocrine effects on pituitary FSH secretion and para/autocrine effects on ovarian and testicular function. The purpose of this study was to investigate the endocrine and para/autocrine regulation of inhibin A and inhibin B secretion in human ovarian granulosa-luteal cells. The cells were obtained from women undergoing in vitro fertilization, and the primary cultures were treated with FSH, LH, human chorionic gonadotropin (hCG), activin A, 8-bromo cyclic AMP (8-BrcAMP), staurosporine (a protein kinase C inhibitor) and an antagonist of IGF action (type-1 IGF receptor antibody alpha IR3). The secretion of inhibins was measured by ELISA assays capable of reliably distinguishing between inhibin A and B. FSH, LH, hCG and 8-BrcAMP increased inhibin A secretion on average up to 180% (P<0.01), 192% (P<0.05), 210% (P<0.01) and 243% (P<0.01) respectively of the control level, while their stimulatory effect on inhibin B secretion was less pronounced (up to 167%, P<0.01; 139%, P<0.05; 127%, P>0.05; 133%, P>0.05 of the controls respectively). alpha IR3 decreased inhibin A and B secretion down to 70% (P<0.01) and 50% (P<0.01) respectively of the control. Staurosporine decreased inhibin B secretion down to 49% (P<0.01) of the control; its effect on inhibin A secretion was not significant. Activin A increased inhibin B secretion up to fourfold of the control (P<0.05) while its effect on inhibin A secretion was insignificant. We conclude that gonadotropins via the protein kinase A signal transduction pathway are the main positive regulators of inhibin A and B secretion in human granulosa-luteal cells. The protein kinase C signal transduction pathway seems to be important especially for inhibin B secretion. Locally produced IGFs are probably important inducers of the production of both forms of inhibin in human ovaries while activins seem to upregulate inhibin B secretion.

Activins↗

PubMed2000

The RsaI polymorphism in the alpha-fibrinogen gene and response of plasma fibrinogen to physical training--a controlled randomised clinical trial in men.

We have previously reported cross-sectional data on an interaction effect between physical activity and alpha-fibrinogen RsaI polymorphism on fibrinogen in postmenopausal women. In the present controlled randomised study, we investigated the role of the RsaI polymorphism in determining the response of fibrinogen to long-term regular exercise. Middle-aged men (n = 140), randomly selected from the population registry, were randomised into an exercise or a reference group for a 3-year low intensity exercise intervention. Complete data were available in 125 men. The RsaI restriction enzyme detects threonine (Thr) to alanine change in the fibrinogen alpha codon 312. Anaerobic ventilatory threshold increased by 4%, but decreased by 2% in the exercise and reference groups, respectively. Mean fibrinogen did not decrease in either study group. However, in the exercise group, individual changes in anaerobic threshold explained 48% of the variance in fibrinogen changes in the Thr homozygotes. Our data offer a new aspect of beneficial effects of regular physical exercise on risk factors for coronary heart disease.

Amino Acid Substitution↗

PubMed1999

Myoglobin, creatine kinase MB, troponin T, and troponin I - rapid bedside assays in patients with acute chest pain.

Three new rapid, qualitative bedside immunoassays were evaluated in the diagnosis of patients with acute chest pain. The subjects, 122 patients in group 1 (bedside tests for myoglobin, creatine kinase MB) and 233 patients in group 2 (bedside tests for troponin I and sensitive troponin T) were admitted to hospital with acute chest pain for less than 12 h. The bedside tests were performed on admission, and 2, 4, and 6 h later. The correlation between the two parts of the rapid creatine kinase MB/myoglobin test during the first 12 h after the onset of chest pain was moderate in all patients (kappa=0.401, 95% confidence interval 0.321-0.483). The highest correlation was seen with the patients with definite and probable myocardial infarction. The correlations were smaller but significant also in other diagnostic groups (unstable angina pectoris, prolonged chest pain, and non-cardiac chest pain). The correlation between the rapid sensitive test for troponin T and rapid test for troponin I was significant in all groups (kappa=0.776, 95% confidence interval 0.711-0.841). The myoglobin part of the rapid creatine kinase MB/myoglobin test may be too non-specific for clinical diagnostic purposes [in non-infarct patients the myoglobin part was significantly more often positive than creatine kinase MB or troponin tests (P<0.001)].

Adult↗

PubMed1999

Regular exercise, plasminogen activator inhibitor-1 (PAI-1) activity and the 4G/5G promoter polymorphism in the PAI-1 gene.

The aim of this controlled randomised clinical trial was to investigate the effects of regular low to moderate intensity physical activity on plasminogen activator inhibitor-1 (PAI-1) activity during three years while taking into account the 4G/5G polymorphism in the promoter of the PAI-1 gene. Male subjects (age 52-62 years, n = 132) were randomised into an exercise or a (non-intervention) reference group. Aerobic threshold increased by 8.8% (p = 0.025) in the exercise group, and decreased by 1.1% in the non-intervention group, while PAI-1 activity did not change significantly in either study group. However, homozygotes for the 4G allele in the exercise group showed a 36% reduction in PAI-1 (p = 0.025). In conclusion, although regular moderate physical activity did not decrease PAI-I activity in the whole group, regular exercise may be effective for controlling elevated PAI-1 level in subjects homozygous for the 4G allele.

Alleles↗

PubMed1998

High-performance liquid chromatography method for analyzing citalopram and desmethylcitalopram from human serum.

This report describes a sensitive and specific method for analyzing a serotonin reuptake blocker, citalopram, and its active metabolite, desmethylcitalopram, in human serum. For high-performance liquid chromatography (HPLC) analysis, samples and standards are prepared with ASPEC automatic sample preparator using 100 mg Bond-Elut C-18 solid-phase extraction columns. The method is an isocratic HPLC method with a mobile phase of acetonitrile:methanol:50 mM dipotassium hydrogenphosphate, pH 4.7 (40:100). Detection is performed with diode array detector at 220 nm and the peak purity analyses at 210 to 365 nm. The intraassay coefficient of variation ranges from 3.7% to 7.3%, and the interassay coefficient of variation ranges from 6.9% to 9.9% at therapeutic drug concentrations. The detection limit is 15 nmol/l. The method is suitable for therapeutic drug monitoring in a clinical laboratory. A clear correlation, r = 0.72 (y = 0.36x + 17.94), between citalopram and its metabolite levels is observed in routine therapeutic drug monitoring service. A linear correlation between serum concentration and daily dose of citalopram in patient groups is also observed.

Chromatography, High Pressure Liquid↗

PubMed1998

Metabolic effects of a low-pressure tourniquet system compared with a high-pressure tourniquet system in arthroscopic anterior crucial ligament reconstruction.

BACKGROUND: Bloodless field is an integral part of orthopedic surgery. Use of tourniquet is associated with a risk of skeletal muscle ischemia and reperfusion injury. The purpose of this prospective, open-randomized study was to determine if the use of a tourniquet system using low pressure, with a wide, curved cuff connected to a microprocessor pump is safer than a standard tourniquet system with a narrow, straight cuff using higher inflation pressures. METHODS: Test parameters used as markers of muscular injury and anaerobic metabolism were femoral vein blood lactate, pH, pCO2, pO2, potassium, aspartate aminotransferase activity, myoglobin, creatine kinase and creatine kinase-MM activity levels after release of tourniquet. Twenty-six ASA I-II patients were studied. RESULTS: Tourniquet times varied between 30 and 144 min. Deflation of the tourniquet caused a significant release of lactate, myoglobin and potassium detected in the femoral vein blood. pCO2 increased, but pH and pO2 decreased after tourniquet deflation. There were no differences between the study groups. The tourniquet time showed a significant correlation with femoral vein lactate. CONCLUSION: The main finding of this study was that the metabolic changes were more pronounced with the longer tourniquet time. The results of the study did not show any difference on metabolic markers of muscular injury during the first hour after release of tourniquet between the two tourniquet systems.

Adolescent↗

PubMed1998

Characterisation and evaluation of external quality assessment scheme serum. Discussion paper from the European External Quality Assessment (EQA) Organisers Working Group C.

This work reviews the procurement, specification and manufacture of serum for external quality assessment (EQA) and provides a checklist for scheme organisers. Guidance on the assessment of commutability and notes on the use of EQA materials to assess assay problems are provided. The importance of the appropriateness of materials in respect of scheme design and objectives, and the essential nature of a detailed specification prior to manufacture are emphasised.

Blood↗

PubMed1998

Hyperglycemia and compositional lipoprotein abnormalities as predictors of cardiovascular mortality in type 2 diabetes: a 15-year follow-up from the time of diagnosis.

OBJECTIVE: We studied the 15-year cardiovascular mortality and morbidity of newly diagnosed patients with type 2 diabetes and of nondiabetic control subjects and the predictors of cardiovascular mortality in diabetic patients. RESEARCH DESIGN AND METHODS: We performed a 15-year prospective study of 133 middle-aged patients with newly diagnosed type 2 diabetes and 144 control subjects. Cardiovascular risk factors were assessed in both groups at baseline and after 5 and 10 years. RESULTS: Total mortality was markedly higher in patients with type 2 diabetes (total: 44.3 vs. 12.9% for men, age-adjusted odds ratio [OR] 5.0, P < 0.001; 44.4 vs. 11.0% for women, OR 5.2, P < 0.001), which was due to increased cardiovascular mortality (ORs for men and women: 6.2 and 11.2, respectively, P < 0.001 for both). The incidences of fatal and nonfatal myocardial infarction and stroke were likewise higher in diabetic patients. In univariate analyses and various multiple logistic regression analyses, hyperglycemia was a constant predictor of cardiovascular mortality assessed at the time of diagnosis or at 5- or 10-year examinations. Moreover, lipoprotein abnormalities characteristic of type 2 diabetes (low HDL cholesterol, high LDL triglycerides or apolipoprotein B levels, and low LDL cholesterol/apolipoprotein B ratio as a marker for LDL size) were predictive of cardiovascular death in these analyses. CONCLUSIONS: This long-term study of a well-characterized group of newly diagnosed patients strengthens the view that the prognosis in middle-aged subjects is markedly impaired and that both hyperglycemia and compositional lipoprotein abnormalities are predictors of cardiovascular mortality in patients with type 2 diabetes.

Age Factors↗