Biomedical subjects

J Liesivuori

Publications and source records attributed to J Liesivuori.

At least 19 recordsLinked to original sources

PubMed2004

A controlled study of tryptophan and cortisol in violent offenders.

Changes in the metabolism of tryptophan, other amino acids, and steroid hormones have been implicated in aggression. We compared tryptophan, competing long amino acids (CAAs), and cortisol in serum (S) and CSF in 22 violent offenders and 15 healthy controls. Offenders had significantly increased S-L-tryptophan, S-free tryptophan, S-CAAs, S-cortisol and CSF-cortisol, indicating abnormal neurophysiological processes. Larger studies on the interplay between violence, serotonin precursors, and stress hormones need to integrate personality traits, life situations, and physiological adaptation.

Adolescent↗

PubMed2003

The effects of wood dusts on the redox status and cell death in mouse macrophages (RAW 264.7) and human leukocytes in vitro.

Wood dusts are classified as carcinogenic to humans and also produce other toxic, allergic, and acute effects in woodworkers. However, little is known about causative agents in wood dusts and their mechanisms of action. The effects of different tree species and particle size for biological activity were studied. The differences in the production of reactive oxygen species (ROS) and cell death (necrotic and apoptotic) between mouse macrophage (RAW 264.7) cells and human polymorphonuclear leukocytes (PMNL) for pine, birch, and beech dust exposures were investigated in vitro. The pine and birch dust exposure (1-100 microg/ml) produced concentration-dependent ROS production in both the cells, which was one order of magnitude higher with pine dust. The ROS production was faster in human PNML than murine RAW cells. The higher concentrations (500 and/or 1000 microg/ml) decreased ROS formation. With pine and birch dust exposure, this was probably due to the necrotic cell death. The pine dust concentrations of 500 and 1000 microg/ml were cytotoxic to human PMNL. The beech dust exposure activated the ROS production and decreased the cell viability only at the highest concentrations, being least potent of the three dusts. A sign of the apoptotic cell death in the murine RAW cells was observed at the pine dust concentration of 100 microg/ml. The exposure to the birch and beech dusts with a smaller particle size (<5 microm) produced greater ROS production than exposure to the corresponding dust with a wide range of particle sizes. However, changing the particle size did not affect the cell viability. The results indicate that the type of wood dust (tree species and possibly particle size) has a significant impact on the function and viability of phagocytic cells.

Animals↗

PubMed2003

Total plasma l-tryptophan, free l-tryptophan and competing amino acid levels in a homicidal male adolescent with conduct disorder.

OBJECTIVE: Several studies have shown abnormal findings in human serotonin metabolism, such as increased total plasma l-tryptophan and free l-tryptophan levels among habitually violent antisocial offenders. It is not clear if these increased l-tryptophan levels are associated with adult antisocial personality disorder (ASP) or history of substance abuse, or if these levels are already present in adolescent subjects with conduct disorder (CD). METHOD: Total plasma and free l-tryptophan and competing amino acids (CAAs) were measured in a 15-year-old adolescent offender, who was convicted for two homicides, and in 10 healthy male controls of similar age and body mass index (BMI). RESULTS: In the juvenile offender, plasma total l-tryptophan/CAA was 84% and free l-tryptophan/CAA 143% higher than average mean among controls. CONCLUSION: From this very aggressive boy with CD, findings of free l- and total l-tryptophan/CAA values were similar to those of habitually violent adult ASP offenders. As severe CDs in adolescence tend to develop into adults with ASP, increased l-tryptophan/CAA and free l-tryptophan/CAA values may serve as early indicators for the development of habitually violent adult offenders.

Adolescent↗

PubMed2003

The 3-year follow-up study in a block of flats - experiences in the use of the Finnish indoor climate classification.

Indoor climate of two new blocks of flats was investigated. The case building was built for people with respiratory diseases by following the instructions of the Finnish Classification of Indoor Climate, Construction and Finishing Materials, while the control building was built using conventional building technology. The main indoor air parameters (temperature, relative humidity and levels of CO, CO2, ammonia, total volatile organic compounds, total suspended particles, fungal spores, bacteria and cat, dog and house dust mite allergens) were measured in six apartments of both the buildings on five occasions during the 3-year occupancy. In addition, a questionnaire to evaluate symptoms of the occupants and their satisfaction with their home environment was conducted in connection with indoor air quality (IAQ) measurements. The levels of indoor air pollutants in the case building were, in general, lower than those in the control building. In addition, the asthmatic occupants informed that their symptoms had decreased during the occupancy in the case building. This case study showed that high IAQ is possible to reach by careful design, proper materials and equipment and on high-quality construction with reasonable additional costs. In addition, the study indicated that good IAQ can also be maintained during the occupancy, if sufficient information on factors affecting IAQ and guidance on proper use and care of equipment are available for occupants.

Air Pollution, Indoor↗

PubMed2001

Free L-tryptophan plasma levels in antisocial violent offenders.

RATIONALE: Several studies have shown that impulsive violent behavior is associated with reduced serotonin metabolism in the brain, but no data exist on possible alterations of the serotonin precursor (free L-tryptophan) levels among violent offenders. OBJECTIVES: To study free L-tryptophan and kynurenine plasma levels among antisocial violent offenders. METHODS: Free L-tryptophan and competing amino acid (CAA) plasma levels were measured among 19 male impulsive antisocial violent offenders and 19 age-matched healthy male controls. RESULTS: Mean free L-tryptophan/(CAA) plasma levels were 160% (95% CI 116%-204%) higher among offenders than controls (P=0.000). Seventeen of the 19 offenders (89.5%) had values of more than 2 SD above the mean value of controls. The levels of kynurenine, the major metabolite of tryptophan, were slightly increased in offenders. CONCLUSION: Free plasma L-tryptophan/CAA levels were markedly increased among antisocial violent offenders indicating a disturbed tryptophan metabolism.

Adult↗

PubMed2000

Indicators of L-arginine metabolism and cardiovascular risk factors--a cross-sectional study in healthy middle-aged men.

This study examines the relationship between traditional risk factors of coronary artery disease and indicators involved in the metabolism of L-arginine (plasma and urine L-arginine, plasma L-citrulline, serum creatinine and urine orotic acid). Our study population consisted of 40 healthy male volunteers aged between 35 and 55 years. We found an inverse association between serum creatinine and blood pressure, between plasma L-citrulline and blood pressure, as well as between urine L-arginine and blood pressure. We also found a positive association between plasma LDL-cholesterol and urine L-arginine and a negative correlation between plasma L-arginine and LDL-cholesterol. Orotic acid measured from urine was not associated with any of the indicators of L-arginine metabolism. Our results indicate that L-arginine metabolism is of profound significance for cardiovascular health. However, our study does not answer questions relating to causality. Further studies are needed to clarify the causal relationship between cardiovascular risk factors, especially elevated blood pressure and high LDL-cholesterol, and indicators of L-arginine metabolism.

Adult↗

PubMed2000

Preliminary report on the results of the second phase of a round- robin endotoxin assay study using cotton dust.

In an on-going endotoxin assay study, a two-part interlaboratory endotoxin assay study has been completed. The purpose of the study was to compare the variation in assay results between different laboratories, and, if the variation was high, to see if a common protocol would reduce the variation. In both parts of the study, membrane filters laden with the same approximate amount and type of cotton dust were sent for analysis to laboratories that "routinely" perform endotoxin analyses. First, each of these laboratories performed the analysis using the methodology common to its laboratory. In the second part of the study, membrane filters with cotton dust were again sent to the same laboratories where the analyses were performed as before but with a common extraction protocol. The preliminary results from the first phase of the study have been collected and showed that intra-laboratory variations were small, but large and significant interlaboratory variation was observed. The results were reported elsewhere. The preliminary results from the second part of the study consisting of the data currently collected are presented here. Again, intra-laboratory variations were small, but, also again, large and significant inter-laboratory variation was observed. However, in this part of the study, the range between the highest and lowest average results was narrower than in the first part of the study. Influence of the assay kit type was examined. The variation within assay kit type was small but significant differences in results were observed between assay kit types. The findings suggest that endotoxin concentration in samples can be ranked within laboratories, but not necessarily between laboratories. However, some of the variation between laboratories has been reduced by a common extraction protocol which suggests the possibility of further standardization that may lead to better comparability between laboratories.

Air Pollution, Indoor↗

PubMed1999

Evaluation of sensory irritation of delta3-carene and turpentine, and acceptable levels of monoterpenes in occupational and indoor environment.

The standard mouse bioassay was used for obtaining the RD50 (i.e., the concentration that causes a 50% decrease in respiratory frequency) and for estimating the irritation properties of d-delta3-carene (i.e., (+)-delta3-carene) and commercial turpentine. The chemicals studied possess mainly sensory irritation properties similar to the previously studied monoterpenes, pinenes. The irritation potency of d-delta3-carene (RD50 = 1345 ppm) was almost equal to that of d-pinenes. Thus, d-delta3-carene was about four times more potent as a sensory irritant than I-beta-pinene, whereas the difference with I-alpha-pinene was more marked; as a sensory irritant, I-alpha-pinene is almost inactive. Based on sensory irritation potency and physicochemical and structural properties of pinenes and delta3-carene, the potency of a closely related monoterpene, limonene, is discussed. For commercial turpentine, a mixture of monoterpenes (mainly d-delta3-carene, I-beta-pinene, alpha-pinenes, and limonenes), the RD50 (1173 ppm) was the same order of magnitude as those of d-pinenes and d-delta3-carene. Apparently, d-monoterpenes are responsible for the sensory irritation caused by turpentine. In the wood industry and in the indoor air of nonindustrial environments, monoterpenes are thought to be one of the causative agents for irritation symptoms. The occupational exposure limit (OEL) of turpentine (100 ppm in Finland and the United States) is also used for individual monoterpenes, excluding limonene. Using results from this and our previous study, proposed OELs and recommended indoor levels (RILs) for selected monoterpenes and turpentine were determined based on their RD50 values. According to our studies, the present OEL of turpentine (100 ppm; 560 mg/m3) in Finland and in the United States seems to be suitable only for I-pinenes. For d-monoterpenes and turpentine, an OEL about three times lower is suggested. Our results show that recommended indoor levels (RILs) for monoterpenes are high compared to the concentrations measured indoors in nonindustrial environments. Thus, it is very unlikely that monoterpenes alone can cause irritation symptoms in homes or offices under normal conditions.

Air↗

PubMed1999

Endotoxins and IgG antibodies as indicators of occupational exposure to the microbial contaminants of metal-working fluids.

OBJECTIVES: The aim of this study was to evaluate workers' exposure to microbes and bacterial endotoxins during the use of metal-working fluids (MWF). METHODS: Air and bulk sampling with biomonitoring of workers' serum IgG antibodies were used to estimate the exposure to biological agents at 18 workplaces. The types of emulsified MWF used were synthetic fluid, mineral oil or rape seed oil, in grinding, turning and drilling work. RESULTS: The endotoxin concentrations in the air ranged from 0.04 to 600 ng/m(3) when the endotoxin levels in MWF were 0.03-25,000 ng/ml. A high correlation was found between the endotoxin levels and the bacterial counts from MWF, as well as between the total culturable bacteria and the gram-negative bacteria concentrations in the air. Comamonas testosteroni and C. acidovorans were the most common strains in the samples but also colonies of Ochrobactrum anthropi, Pantoea agglomerans and Stenotrophomonas maltophilia were isolated from the workplaces. Fungi like Aspergillus, Cladosporium and Penicillium species were identified in the air but only rarely in the MWF. Positive IgG antibodies were found in the sera of 22 of the 25 MWF workers examined. Antibodies against S. maltophilia, P. agglomerans and C. acidovorans were the most common, appearing in 72%, 64% and 64%, respectively, of the cases. The MWF workers showed significantly higher IgG antibody responses to bacterial antigens than did the controls. CONCLUSIONS: The results clearly proved that in occupational hygiene measurements, endotoxins serve as excellent indicators of exposure to the microbial contaminants of MWF. IgG antibodies against antigens identified from workplace samples could be a practical tool for occupational health physicians.

Air Microbiology↗

PubMed1999

Occupational exposure to alkoxysilanes in a fibreglass manufacturing plant.

OBJECTIVE: To assess the exposure of workers to alkoxysilanes and to determine the main route of exposure during the manufacture of fibreglass. METHODS: Occupational hygiene samples were taken from workers and their environment in a fibreglass factory during filament forming and the handling of coated fibres. The total exposure of workers to silanes was assessed by the collection of air samples into impinger flasks at stationary sampling sites, by the use of absorbent patch samples on workers' clothes or skin and from handwash samples. During the time of our field survey, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane were being used in different sizing mixtures. The samples were analysed by gas and liquid chromatography. RESULTS: The silane concentrations in the air samples were below the detection limits of the analytical methods. The mean dermal exposure to 3-glycidoxypropyltrimethoxysilane, analysed from the patch samples, was 2,800 mg h(-1) in the forming room and 800 mg h(-1) in the winder room. The corresponding figures for 3-methacryloxypropyl-trimethoxysilane were 3 and 9 mg h(-1). As determined in the handwash samples, the mean exposure to 3-glycidoxypropyltrimethoxysilane through the hands was 1,500 mg h(-1) in the forming room and 1,800 mg h(-1) in the winder room, the respective values for 3-methacryloxypropyltrimethoxysilane being 110 mg h(-1) and 90 mg h(-1). Only small quantities of 3-aminopropyltriethoxysilane were found in a few handwash samples. CONCLUSIONS: Our results showed that the workers in the fibreglass factory were clearly exposed to silanes. The main route of potential exposure was through the skin, especially the hands, which emphasised the importance of wearing appropriate protective gloves. According to the patch sampling, on average two thirds of the total dermal exposure was caused by exposure of the forearm, as indicated by the amounts of silanes analysed in the forearm patches. Since almost every worker was wearing protective gloves, the main occupational health finding concerning exposure to silanes was that short-sleeved T-shirts did not provide any protection to the arms.

Air Pollutants, Occupational↗

PubMed1999

Gas chromatographic determination of some alkoxysilanes for use in occupational exposure assessment.

The manufacture and application of organosilicon compounds, especially silanes, have increased dramatically during recent decades. This has led to an increase in the number of exposed workers in different areas of industry. Therefore, there is an urgent need for an analytical method which can assess exposure to these compounds. A capillary column gas chromatographic (GC) method was developed for detecting 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane and 3-aminopropyltriethoxysilane. The silanes diluted in heptane were analysed by GC using flame ionisation detection. Gas chromatography-mass spectrometry was used to confirm the identity of the GC peaks. The analytical range of the method varied from 1 or 5 micrograms ml-1 to 500 micrograms ml-1 depending on the silane being studied. The detection limits were 1 microgram ml-1 for 3-methacryloxypropyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane and 5 micrograms ml-1 for 3-aminopropyltriethoxysilane. The mean recovery of silanes tested with patch samples was > 95% for all of the silanes. The repeatability of the patch sample method for silanes varied from 6.5 to 10.1%. This new GC method allows the simultaneous determination of three organosilicon compounds for occupational exposure assessment.

Chromatography, Gas↗

PubMed1999

Exposure to airborne microorganisms and volatile organic compounds in different types of waste handling.

Occupational exposure of workers to airborne microorganisms and volatile organic compounds (VOC) in different types of waste treatment situations was examined during summer time. Microorganisms were collected as stationary samples using a six-stage Andersen impactor, while for VOCs both personal and stationary sampling was conducted. The exposure at the waste handling facility was considerably greater than at landfill sites or in waste collection. The concentrations of viable fungi were maximally 10(5) cfu/m3, and the concentrations of both total culturable bacteria and Gram-negative bacteria exceeded the proposed occupational exposure limit values (OELV), being 10(4) and 10(3) cfu/m3, respectively. Exposure to VOCs in the waste handling facility was three times higher than at the landfill sites, being at highest 3000 microg/m3, considered to be the limit for discomfort. The use of personal protective equipment at work, thorough hand washing and changing clothes after the work shift are strongly recommended in the waste handling facility and the landfill sites.

Air Microbiology↗

PubMed1998

Urinary NAG and GAG as biomarkers of renal effects in exposure to 2-alkoxyalcohols and their acetates.

Many sensitive biomarkers are available for the surveillance of the early health effects of chemicals on humans. This study was conducted to evaluate the usefulness of glycosaminoglycans (GAG) as biomarkers of early kidney effects in exposure to 2-alkoxyethanols and their acetates. GAG were compared with effects on the urinary beta-N-acetylglycosaminidase activity (NAG). According to the results of the present study, the excretion rate of GAG was higher among women than men. On the other hand, the excretion rate of GAG was lower among exposed subjects than among the controls, and the level was decreased at the tested levels of exposure. The NAG activity was higher in most of the exposed groups than in the controls. The data indicated that an appropriate urinary limit value for ethoxyacetic acid was 30 mmol/mol creatinine in postshift samples and that this value corresponded to an 8-hour exposure level of 2 cm3/m3 2-ethoxyethylacetate. Urinary butoxyacetic acid excretion of 60 mmol/mol creatinine corresponded to the inhalation exposure level of 5 cm3/m3 2-butoxyethanol and its acetate in postshift samples.

Acetates↗

PubMed1998

Qualitative identification of volatile metabolites from two fungi and three bacteria species cultivated on two media.

Two fungal species, Aspergillus fumigatus and Penicillium brevicompactum and three bacteria, Klebsiella pneumoniae, Enterobacter agglomerans and Streptomyces albus were cultivated on two media, malt extract agar and dichloran glycerol agar. The volatile metabolite samples from the cultures were adsorbed on Tenax TA and analyzed qualitatively by thermal desorption gas chromatography and with a mass selective detector. Various hydrocarbons, alcohols, ketones, esters and terpenes were identified. The production was highly dependent on both the medium and the microbial species. 2-Methyl-1-propanol, 2-methyl-1-butanol and 3-methyl-1-butanol were the most commonly produced substances. The bacterial species did not produce any hydrocarbons that were characteristic to the fungi (e.g. methyl-1,3-pentadiene, 1-octene and 1,3-octadiene or 8-carbon alcohols 1-octen-3-ol and 3-octanol). Instead, K. pneumoniae and E. agglomerans produced 3-hydroxy-2-butanone and 1-hydroxy-2-propanone, which were not produced by the fungi. Geosmin and a large number of sesquiterpenes were produced by S. albus.

Air Microbiology↗

PubMed1997

Biological monitoring of occupational exposure to 1-methoxy-2-propanol.

At the end of a workweek 23 silkscreen printers gave a urine sample for capillary gas chromatographic analysis for 1,2-propanediol. The mean concentration was 2.52 (S.D. 2.01) mmol mol creatinine(-1) (median=1.76, n=23). The urinary excretion of 1,2-propanediol was linearly dependent on the preceding 1-methoxy-2-propanol exposure measured in the worker's breathing zone [y=0.99+0.28x, n=23, r=0.67, where y is the urinary 1,2-propanediol concentration, in mmol mol creatinine(-1) and x is the concentration, in cm3 m(-3), of 1-methoxy-2-propanol (90.2%), 1-ethoxy-2-propyl acetate (5.8%), 1-methoxy-2-propyl acetate (2.1%) and 1-ethoxy-2-propanol (1.9%) in the air].

Chromatography, Gas↗

PubMed1996

Biological monitoring of deltamethrin exposure in greenhouses.

This study examined the possibility of using biological monitoring to assess deltamethrin exposure among greenhouse workers. The synthetic pyrethroid deltamethrin was sprayed in five greenhouses by cold for generators, and the exposure was biologically monitored by analysing the concentration of its metabolite, 3-phenoxybenzoic acid, by a gas chromato-graphic method after derivatization with pentafluorobenzyl bromide. 3-Phenoxybenzoic acid was found in the urine of two of the ten workers studied. The urine concentration of the metabolite varied from 2.4 to 51.7 micrograms/l. These results show that 3-phenoxybenzoic acid is suitable for biological monitoring for the assessment of exposure to deltamethrin.

Adult↗

PubMed1996

Determination of urinary 2-mercaptobenzothiazole (2-MBT), the main metabolite of 2-(thiocyanomethylthio)benzothiazole (TCMTB) in humans and rats.

A method for biological monitoring of urinary 2-(thiocyanomethylthio)benzothiazole (TCMTB), a wood preservative and an industrial chemical, was developed. Three different doses of TCMTB in olive oil were given to male rats by gavage for 3 weeks. Urine was collected daily and the metabolites were analysed as thioethers by derivatization with pentafluorobenzyl-bromide by gas chromatography-mass spectrometry. The parent chemical was not detected in urine samples, but two metabolites of TCMTB were identified. 2-Mercaptobenzothiazole (2-MBT) was the main metabolite, and its excretion varied according to the dose. The second metabolite was 2-(mercaptomethylthio)benzothiazole. The amount of 2-MBT excreted in rat urine was 66 +/- 12% (SD), 51 +/- 20% and 44 +/- 9% for TCMTB doses of 15, 75 and 150 mg/kg, respectively. Two doses, 75 and 150 mg/kg, caused diuresis in rats during the 1 week of dosing. During the 3-week TCMTB treatment, rat liver microsomal CYP enzyme profile was not significantly changed. Urine samples of sawmill workers exposed to TCMTB were collected after their work shifts for exposure assessment. TCMTB could not be detected in the urine samples of exposed workers. Most concentrations of 2-MBT were below the limit of the detection, 0.12 mumol/l, the concentrations were 0.12-0.15 mumol/l only in few cases. The determination of 2-MBT in urine, when a sample is taken immediately after a work shift, is a suitable indicator of workers' exposure to TCMTB.

Animals↗

PubMed1996

Reactions of hydrated formaldehyde in nasal mucus.

Formaldehyde is a well known toxic air impurity affecting the upper respiratory tract. It rapidly forms methylene glycol in water. Reactions of the hydrated formaldehyde with nasal mucus were studied by C-13 NMR spectroscopy. In the NMR spectra methylene glycol dominated and only minor signals from possible reactions were observed. This finding suggests that nasal mucus effectively protects nasal epithelium against formaldehyde.

Carbon Isotopes↗