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Biomedical subjects

K Laitinen

Publications and source records attributed to K Laitinen.

At least 55 records · Page 3Linked to original sources
PubMed1996

Expression of adhesion molecules on endothelial cells stimulated by Chlamydia pneumoniae.

Previous studies have shown that C. pneumoniae is able to infect human endothelial cells in vitro. In this report, the ability of C. pneumoniae to induce the expression of E-selectin or endothelial-leukocyte adhesion molecule 1 (ELAM-1), intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) on human umbilical vein endothelial (HUVE) cell surface was investigated. C. pneumoniae was found to cause a moderate upregulation of the adhesion molecules. Maximal expression of E-selectin was noted at 6 h post infection (p.i.) and that of ICAM-1 and VCAM-1 at 20 h p.i. The capability of C. pneumoniae to grow in endothelial cells and to stimulate the expression of adhesion molecules essential for leukocyte-endothelial cell interactions suggests a role for C. pneumoniae as a local pathogenetic factor in vascular inflammatory alterations, including atherogenesis.

Cells, Cultured↗
PubMed1996

Common polymorphism of the vitamin D receptor gene is associated with variation of peak bone mass in young finns.

Previous studies suggested a relation between polymorphism of the vitamin D receptor (VDR) gene and bone mineral density (BMD) at perimenopausal age. To enlighten the possible association of the VDR gene polymorphism and BMD, we studied young (20-29 years) adults whose BMD provides a measure of their maximal bone mass. After sequencing the DNA regions flanking the polymorphic BsmI site, we set up a specific solid-phase minisequencing technique to assay this allelic variation. BMD values were adjusted for age, sex, weight, physical activity, smoking, and calcium intake. Young subjects homozygous for the b allele (BsmI site present) had a significantly higher BMD in lumbar spine and femoral neck than those homozygous for the B allele (BsmI site absent). This data shows that the BsmI polymorphism of the VDR gene is associated with peak bone mass. The implication of this result regarding the prevention of osteoporosis deserves further attention.

Adult↗
PubMed1996

Biological markers of alcohol consumption and effect of calcitonin in nonalcoholic men: a prospective, double-blind study.

The objective of this study was to study the ability of biological markers of alcohol consumption in differentiating subjects below weekly consumption of 400 or 600 g of absolute ethanol from those above, and to study the effect of intranasal calcitonin on alcohol drinking. A prospective 12-week double-blind study that used anonymous data collection with drinking diaries was done. The drug that was studied (calcitonin or placebo) was used during study weeks 5-8. This study was performed at the research unit of a university hospital. The subjects consisted of 59-nine men aged 26 to 57 years who considered themselves as regular but modest drinkers and were recruited by advertisements. The measurements were obtained from monthly questionnaires and daily anonymous diaries for alcohol drinking data, and biological markers of alcohol consumption (aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transpeptidase, beta hexosaminidase, and carbohydrate deficient transferrin). The results indicated intranasal calcitonin with a dose of 200 IU three times a week had no effect on alcohol use. All biological markers studied had only a modest ability to differentiate those with weekly alcohol consumption of 400 or 600 g or over from those below these limits. The areas under receiver operating characteristic (ROC) curve with the limit 400 g/week were 0.71 for aspartate aminotransferase, 0.61 for alanine aminotransferase, 0.74 for gamma-glutamyl transpeptidase, 0.68 for beta-hexosaminidase, and 0.78 for carbohydrate deficient transferrin. Respective numbers for the 600-g limit were more uniform. As evaluated by ROC analysis, carbohydrate deficient transferrin was the best biological marker to find men with weekly alcohol consumption over 400 g. Intranasal salmon calcitonin had no affect on alcohol drinking.

Administration, Intranasal↗
PubMed1996

Reactivation of Chlamydia pneumoniae infection in mice by cortisone treatment.

Reactivation of Chlamydia pneumoniae infection was studied by inducing immunosuppression by cortisone acetate treatment given every other day for 14 days in intranasally infected NIH/s mice. The treatment started 2 or 4 weeks after primary infection, when no C. pneumoniae was detected. C. pneumoniae could be recovered from the lung cultures on days 7 and 9 in 10 and 60% of the mice, respectively, when cortisone treatment was begun 30 days after infection. These results confirm the persistent nature of C. pneumoniae infection.

Animals↗
PubMed1995

Experimental Chlamydia pneumoniae infection in mice: effect of reinfection and passive immunization.

NIH/S mice were infected intranasally with Chlamydia pneumoniae isolate Kajaani 6 and rechallenged after either 28 or 70 days. A partial resistance to reinfection, indicated by a reduced recovery of live organisms, was noted at both time points of rechallenge: positive isolations from lung homogenates and/or bronchoalveolar lavage fluids were observed in fewer mice and the yields of isolated chlamydiae remained smaller, as compared to primary infection. However, a previous infection did not confer any protection against inflammatory changes. A strong peribronchial and perivascular inflammation with infiltrating lymphocytes and plasma cells was noted in the lungs of primary infected, as well as reinfected, mice. The effect of passive immunization was also studied. When mice were given convalescent or hyperimmune sera intraperitoneally before inoculation, lower C. pneumoniae isolation yields were detected. As in the rechallenge experiment, marked inflammation could still be seen in the lungs, now with polymorphonuclear leukocyte infiltration. The results suggest that immunological reactions play a role in the pathogenesis of C. pneumoniae infection. Antibodies may be important in reducing the amount of infective elementary bodies, but complete clearing of C. pneumoniae could not be achieved in these experiments, even less a protection against inflammatory lung changes.

Animals↗
PubMed1995

Effects of needle age, long-term temperature and CO(2) treatments on the photosynthesis of Scots pine.

Naturally regenerated 20-25-year-old Scots pine (Pinus sylvestris L.) trees were grown in open-top chambers in the presence of an elevated temperature or CO(2) concentration, or both. The elevated temperature treatment was administered year-round for 3 years. The CO(2) treatment was applied between April 15 and September 15 for 2 years. The photosynthetic responses of 1- and 2-year-old needles to varying photon flux densities (0-1500 micro mol m(-2) s(-1)) and CO(2) concentrations (350, 700 and 1400 micro mol mol(-1)) during measurement were determined. The CO(2) treatment alone increased maximum photosynthetic rate and light-use efficiency, but decreased dark respiration rate, light compensation and light saturation regardless of needle age. In contrast, the temperature treatment decreased maximum photosynthetic rate and photosynthetic efficiency, but increased dark respiration rate, light compensation and light saturation. The aging of needles affected the photosynthetic performance of the shoots; values of all parameters except photosynthetic efficiency were less in 2- than in 1-year-old needles. The CO(2) treatment decreased and the temperature treatment enhanced the reduction in maximum photosynthesis due to needle aging.

Journal Article↗
PubMed1995

Role of plasma vasopressin in changes of water balance accompanying acute alcohol intoxication.

Acute alcohol intoxication causes diuresis presumably resulting from inhibition of vasopressin (also called antidiuretic hormone) release from the posterior pituitary gland. In contrast, in alcoholics during withdrawal from alcohol, vasopressin release is stimulated, resulting in water retention (antidiuresis) and dilutional hyponatremia. The purpose of this study was to evaluate the role of this biphasic response of vasopressin secretion to alcohol in normal persons. We studied eight healthy men who took part in two study sessions: one involving the ingestion of ethanol (1.2 g/kg of body weight) and the other the ingestion of the same volume of fruit juice during 3 hr from 6 to 9 PM. Starting at 6 AM the following morning, subjects were loaded with water (20 ml/kg of body weight within 15 min). During the first 3 hr of the study, ethanol intake increased diuresis, whereas from midnight to 6 AM, a phase of antidiuresis was obtained. Antidiuresis continued during water loading when the retention of water was 44 +/- 6% during the alcohol experiment and 12 +/- 4% during the control session (p < 0.05). During the alcohol-induced diuresis, the plasma arginine vasopressin levels did not differ from the control experiment, but were higher during the phase of antidiuresis from 10 PM to 6 AM (p < 0.05- < 0.01). Also, after water loading at 8 and 9 AM, they were higher in the alcohol study than in the control experiment (p < 0.05). After alcohol ingestion, serum osmolality was higher than the corresponding control values from 8 PM to 2 AM (p < 0.01- < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Gonadal function and morphology in non-cirrhotic female alcoholics: a controlled study with hormone measurements and ultrasonography.

OBJECTIVE: To study the occurrence and mechanisms of gonadal dysfunction in women with alcohol abuse. DESIGN: Prospective study. SETTING: Helsinki University Central Hospital. SUBJECTS: Fifteen consecutive chronic female alcoholics without liver cirrhosis admitted for withdrawal treatment, were studied after cessation of alcohol intake. Twelve women had regular menstrual cycles, two appeared to be menopausal and one had hypothalamic amenorrhoea. The women with regular cycles were compared with eleven healthy controls. INTERVENTION: Blood was sampled for hormone measurements three times on cycle days 5 to 7, 11 to 14, and 19 to 22, and ultrasonography was performed on the same days as the first two hormonal studies. MAIN OUTCOME MEASURES: Serum LH, FSH, prolactin, estrone, estradiol, progesterone, testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS), sex hormone-binding globulin (SHBG), the ovarian volume, the follicular diameter, the endometrial thickness. RESULTS: During the luteal phase of the menstrual cycle the serum concentration of testosterone was 65% (p < 0.01) higher and that of progesterone 23% (p > 0.05) lower in patients than in controls. During the follicular phase serum DHEAS level was decreased by 39% (p < 0.05) in patients. Otherwise the serum concentrations of the hormones studied were similar in patients and in controls. As assessed by ultrasonography, patients and controls did not differ with regard to size of the ovaries, follicle development, or the endometrial thickness. CONCLUSIONS: Even heavy alcohol use has only minor permanent effects on ovarian function, at least until development of liver cirrhosis.

Age Factors↗
PubMed1994

Exercise, smoking, and calcium intake during adolescence and early adulthood as determinants of peak bone mass. Cardiovascular Risk in Young Finns Study Group.

OBJECTIVE: To evaluate the contribution to peak bone mass of exercise, smoking, and calcium intake in adolescents and young adults. DESIGN: Prospective cohort study with end point measurement (bone mineral density) after 11 years' follow up for lifestyle. SETTING: Five university hospital clinics. SUBJECTS: 264 (153 females, 111 males) subjects aged 9 to 18 years at the beginning of the follow up and 20 to 29 years at the time of measurement of bone mineral density. MAIN OUTCOME MEASURE: Bone mineral density of lumbar spine and femoral neck by dual energy x ray absorptiometry; measures of physical activity and smoking and estimates of calcium intake repeated three times during follow up. RESULTS: In the groups with the lowest and highest levels of exercise the femoral bone mineral densities (adjusted for age and weight) were 0.918 and 0.988 g/cm2 for women (P = 0.015, analysis of covariance) and 0.943 and 1.042 g/cm2 for men (P = 0.005), respectively; at the lumbar spine the respective values were 1.045 and 1.131 (P = 0.005) for men. In men the femoral bone mineral densities (adjusted for age, weight, and exercise) were 1.022 and 0.923 g/cm2 for the groups with the lowest and highest values of smoking index (P = 0.054, analysis of covariance). In women the adjusted femoral bone mineral density increased by 4.7% together with increasing calcium intake (P = 0.089, analysis of covariance). In multiple regression analysis on bone mineral density of the femoral neck, weight, exercise, age, and smoking were independent predictors for men; with weight, exercise, and age for women. These predictors together explained 38% of the variance in bone mineral density in women and 46% in men. At the lumbar spine, weight, smoking, and exercise were predictors for men; and only weight for women. CONCLUSIONS: Regular exercise and not smoking is important in achieving maximal peak bone mass in adolescents and young adults.

Absorptiometry, Photon↗
PubMed1994

Bone mineral density measured by dual-energy x-ray absorptiometry and novel markers of bone formation and resorption in patients on antiepileptic drugs.

In patients on antiepileptic drugs, bone loss has been mainly demonstrated at radial sites using old technology and has been ascribed to drug-induced vitamin D deficiency rather than to any direct effects of the treatment on bone cells. We examined 38 epileptic patients (24 women and 14 men) aged 20-49 years who were using either carbamazepine or phenytoin or both. Bone mineral density (BMD) at the lumbar spine and three femoral sites was measured by dual-energy x-ray absorptiometry (DXA) and serum and urine markers of bone and mineral metabolism were determined. The latter included the C-terminal extension peptide of type I procollagen (PICP), a putative serum marker of bone formation, and the cross-linked carboxyl-terminal telopeptide of human type I collagen (ICTP), a novel serum marker of bone matrix degradation. In female patients on phenytoin, weight- and height-adjusted BMD was reduced at the femoral neck and the Ward's triangle (p < 0.05) but was at the control level in the other patient groups at all four measurement sites. Compared with controls, the serum concentrations of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were reduced by 26% (p < 0.01) and by 27% (p < 0.001) in female patients. These changes were independent of the therapy used. They were not present in male patients. For both genders the serum levels of vitamin D binding protein were normal. Both female and male patients had hypocalcemia, but women only showed hypocalciuria.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1994

Chlamydia pneumoniae multiplies in human endothelial cells in vitro.

The ability of three C. pneumoniae isolates, Kajaani 6, Helsinki 12 and TW-183, to grow in human umbilical vein endothelial cells (HUVEC) and in an immortalized endothelial cell line EA.hy 926 was studied. All C. pneumoniae isolates were capable of multiplying in endothelial cells. EA.hy926 cells could support the growth of C. pneumoniae better than HUVEC, yet less efficiently than HL and HEp-2 cells that are conventionally used in C. pneumoniae culturing. Although centrifugation of the inoculum greatly increased the inclusion yields, it was not necessary for infectivity. In addition, a persistent infection of C. pneumoniae in EA.hy 926 and HL cells ensued and it was followed up for two months. The fact that endothelial cells can serve as hosts to C. pneumoniae might be a significant contributing factor in the pathogenesis of atherosclerosis, a disease which recent studies show to be associated with chronic C. pneumoniae infection.

Cells, Cultured↗
PubMed1994

Nocturnal rise in markers of bone resorption is not abolished by bedtime calcium or calcitonin.

As assessed by urine pyridinium cross-links, bone resorption increases at night. This has been ascribed to either the nocturnal rise of serum parathyroid hormone (PTH) or immobilization. ICTP is the carboxyterminal telopeptide region of type I collagen in bone, cross-linked via pyridinium cross-links and liberated during the degradation of type I collagen. To study whether the nocturnal rise in bone resorption is seen also in serum type I collagen carboxyterminal telopeptide (ICTP) and whether this rise is abolished by bedtime calcium or calcitonin, nine healthy postmenopausal women participated in three 24 hour sessions. At 2200 hours, either 1 g of oral calcium or 200 IU of intranasal calcitonin or no treatment (control session) were given. The participants were recumbent from 2200 hours to 0600 hours. Like urinary pyridinolines, serum ICTP showed a clearcut nocturnal rise during the control session, increasing from 3.7 +/- 0.3 micrograms/liter (mean +/- SE) at 2000 hours to 4.9 +/- 0.4 micrograms/liter at 0600 hours (P < 0.001). Administration of calcium did not affect either serum ICTP or urinary pyridinolines, although it decreased serum intact PTH by 18% (P < 0.001) as assessed by areas under curve (AUC) after 2200 hours. Serum ICTP and urinary pyridinolines remained unchanged also after administration of calcitonin which increased the AUC for serum intact PTH by 9% (P < 0.05). In conclusion, serum ICTP follows a circadian rhythm in healthy postmenopausal women. The nocturnal rise in markers of bone resorption is not due to PTH, and its dependency on the function of osteoclasts is open to question.

Administration, Intranasal↗
PubMed1994

Mechanisms of hypocalcemia and markers of bone turnover in alcohol-intoxicated drinkers.

Studies of hypocalcemia and osteoporosis frequently encountered in heavy users of alcohol have previously been performed on alcoholic people who have already recovered from alcohol intoxication. Bone and mineral metabolism during and after the intoxication may be different. We measured serum parameters of bone and mineral metabolism in 26 alcohol-intoxicated men and in 19 healthy control men. Although serum ionized calcium was 12% (P < 0.0001) lower in the patients than in the controls, serum intact parathyroid hormone was similar in the study groups. As reflected by decreased serum levels of osteocalcin (-43%; P < 0.001), bone formation was depressed in the patients. Serum cross-linked carboxyterminal telopeptide of human type I collagen (ICTP), a novel parameter of bone matrix degradation, was 9% higher in the patients (P = 0.03) than controls. The positive correlation between serum osteocalcin and ICTP in the controls (r = 0.59, P < 0.01) was absent in the patients (r = 0.05, P = 0.8). We conclude that in alcohol-intoxicated alcohol users, the parathyroid glands do not respond normally to a hypocalcemic stimulus, and that depressed bone formation is uncoupled from accelerated bone resorption.

Adult↗
PubMed1994

Carbohydrate-deficient transferrin during 3 weeks' heavy alcohol consumption.

To study the effect of controlled heavy drinking of 60 g ethanol/day for 3 weeks on carbohydrate-deficient transferrin (CDT), a commercial double antibody kit (CDTect) was used. By the end of the third drinking week, a statistically significant increase in the mean CDT level was observed. When compared to AST and gamma-glutamyltransferase, CDT was a more informative marker. However, only in 2 of the 10 volunteers did CDT exceed the upper normal level (20 units/liter) recommended by the manufacturer. This indicates that the sensitivity of CDT to detect heavy drinking is lower than that previously reported. The higher accuracy has in general been obtained in studies comparing healthy controls with a low alcohol consumption to alcoholics with an alcohol consumption higher than that used in the present experiment. Our results suggest that it remains to be established whether CDT, although better than AST and gamma-glutamyltransferase, will provide a clinically useful tool in identifying heavy drinkers in populations covering a wide range of alcohol consumption.

Adult↗