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At least 307 records · Page 17Linked to original sources
PubMed2001

Occupational exposure to wood, formaldehyde, and solvents and risk of nasopharyngeal carcinoma.

Our objective was to evaluate the link between occupational exposures to wood dust, formaldehyde, and solvents and the development of nasopharyngeal carcinoma (NPC). A case-control study was conducted among 375 newly diagnosed cases of NPC in Taipei, Taiwan, and 325 community controls matched to cases on sex, age, and geographical residence (99 and 87% response rates, respectively). Most cases (>90%) were diagnosed with WHO Types 2 or 3 (nonkeratinizing and undifferentiated carcinomas), whereas the remaining cases were diagnosed with WHO Type 1 (squamous cell carcinomas). A complete occupational history was obtained via a personal interview and blindly assessed by an industrial hygienist for intensity and probability of exposure to wood dust, formaldehyde, and solvents. Information on socio-demographic characteristics, cigarette smoking, dietary consumption of nitrosamines, and other potential confounding factors was obtained via a personal interview. Blood specimens were tested for human leukocyte antigen class I/II genotypes, polymorphisms in cytochrome P450 2E1 genotype, and various anti-EBV antibodies known to be associated with NPC. Analysis was performed using logistic regression; relative risk (RR) estimates and 95% confidence intervals (CI) were calculated. Individuals exposed to wood dust had an adjusted RR of 1.7 (95% CI = 1.0-3.0). Those exposed to wood dust for >10 years had an adjusted RR of 2.4 (95% CI = 1.1-5.0; p(trend) = 0.02). Risk was strongest for those first exposed before the age of 25 years and those seropositive to EBV. Individuals exposed to formaldehyde were at a more modest and nonsignificant increased risk of NPC (RR = 1.4; 95% CI = 0.93-2.2). Those exposed to formaldehyde for >10 years had an adjusted RR of 1.6 (95% CI = 0.91-2.9). The association between formaldehyde and NPC was stronger in analyses restricted to EBV seropositive individuals (RR = 2.7; 95% CI = 1.2-5.9). However, no dose response was observed with increasing duration or cumulative use. No association was observed between solvent exposure and NPC (RR = 1.2; 95% CI = 0.86-1.7). Occupational exposure to wood dust is likely to be involved in the development of NPC, a finding that is consistent with the known link between wood exposure and nasal adenocarcinomas. Formaldehyde exposure is less clearly linked to NPC, whereas exposure to solvents is unlikely to be involved in NPC pathogenesis.

Adolescent↗
PubMed2001

Asthma from inhalation of Triplochiton scleroxylon (Samba) wood dust.

The inhalation of wood dust may produce allergic rhinitis, asthma, or contact dermatitis in sensitized patients. We describe a patient with occupational asthma induced by the inhalation of samba (Triplochiton scleroxylon) wood dust. A specific bronchial provocation test was conducted, and the patient showed a significant decrease in forced-expiratory volume in first second (FEV1) after the inhalation of nebulized samba wood allergens. We suggest an IgE-mediated mechanism since the patient had a positive skin test and positive specific IgE determinations using an extract of samba wood. SDS-PAGE immunoblots revealed IgE binding to proteins with molecular weights of 17 kDa, 28 kDa and less intense binding to a band with an approximate molecular weight of 60 kDa. Two asymptomatic skin test-negative subjects, also occupationally exposed to samba, did not show any signs of bronchoconstriction when challenged with the samba wood extracts. We conclude that the occupational asthma suffered by this patient is related to sensitization and occupational exposure to samba wood dust.

Allergens↗
PubMed2004

Investigation into the material properties of beech wood and cortical bone.

When testing medical implants it is very important to be able to test the implant using a suitable material. In the case of orthopaedic implants the optimum material is bone. Beech wood is considered a suitable substitute for bone as it has a similar Young's modulus in tension. Although it is widely used, no actual comparison of the two materials has been undertaken. The aim of this study was to compare the material properties of beech wood and cortical bone using conventional compression tests. Cortical bone samples 4 mm in diameter and 20 mm in length, were prepared from the tibia of an amputated leg. Beech wood samples were prepared to the same specifications. In compression, the Young's modulus for cortical bone was found to be 27+/-9.9 GPa (mean +/- standard deviation) and for beech wood 2.6+/-1.7 GPa. The failure load for cortical bone was 911+/-207 N and 732+/-62 N for beech wood. Although beech wood has been used as a substitute for bone in some studies, this study has shown that there are significant differences in the properties of the two materials when they are subjected to compression.

Biomimetic Materials↗
PubMed2004

Compost odor control using high carbon wood ash.

A pilot study on the feasibility of using high carbon wood ash to control composting odor emissions was conducted at a green material composting facility. The study's treatments consisted of adding 0%, 12.5%, and 25% high carbon wood ash by volume to green-material compost feedstock in three separate windrows. The wood ash has properties similar to activated carbon with an active surface area of 105 square metres per gram on a dry weight basis. The odorant emission data suggest that the higher percentage wood ash treatment results in the most effective control of most compost odors and that wood ash provides effective treatment of volatile fatty acids and some aldehydes and ketones. The 25% wood ash treatment resulted in more effective treatment of odors for a longer time period than the 12.5% treatment. Acetaldehyde had the highest concentration in the control (14,000 times its odor threshold concentration), was reduced by high carbon ash by over 97% but remained 386 times its reported odor threshold concentration after 14 days. Ethyl mecaptan and ammonia were produced in the process and were also over their reported human detection limits.

Adsorption↗
PubMedDate not supplied

[Longitudinal changes of pulmonary function in workers with high wood dust exposure levels].

BACKGROUND: It is well know that wood dust exposure can induce sino-nasal cancers, rhinitis and asthma; induction of chronic bronchial obstruction, pulmonary fibrosis and lung cancer are also suggested, but data are often inconclusive and in disagreement. OBJECTIVES: The study evaluated the decrease in lung function in a group of 31 non-smokers exposed to high levels of wood dust (> 5 mg/m3 also) and in 2 non-smokering control groups with comparable lung function tests at first examination: 39 mechanical workers without respiratory hazards (group 1) and 30 forestry workers (group 2). METHODS: Assessment of lung function was repeated at least 5 times during 11.2 +/- 2.4 years for wood workers and 12.3 +/- 4.2 years for group 1 (n.s.) and 15.0 +/- 2.6 years for group 2 (p < 0.0005). Linear regression for annual loss of VC and FEV1 was calculated from observed data for each subject. RESULTS: No significant differences were observed in VC loss or FEV1 loss between woodworkers and control group1 (20.67 +/- 16.9 vs 19.0 +/- 23.2 and 31.37 +/- 22.3 vs 36.2 +/- 22.4 ml/year respectively), while control group 2 showed an accelerated (p < 0.005) VC and FEV1 loss (32.8 +/- 22.1 and 46.6 +/- 21.2 ml/years respectively). In conclusion, the study did not show any alterations in the longitudinal decrease in pulmonary function due to high wood dust exposure levels, perhaps due to the poor inhalability of wood particles that are mostly trapped in the nose; further studies are needed to investigate chronic effects of wood dust exposure on development of Chronic Obstructive Pulmonary Disease, pulmonary fibrosis and also lung cancer.

Adult↗
PubMed1997

[Pneumoconiosis and exposure to wood].

The authors report a case of an employee in the wood processing industry. The clinical presentation was respiratory with dyspnoea on effort. The chest x-ray showed bilateral interstitial changes. Following bronchioalveolar lavage electron microscopic studies showed evidence of silica particles. Respiratory function tests showed pulmonary performance of 51%-64% of theoretical values depending on the test used. His working position involved the up keep of the boilers and also the drainage of the silos for wood dust. The wood used was corupixa, a brazilian wood containing crystalline silica; 0.1% in fresh wood dust. Numerous analyses have specified the percentage of silica in the ashes in magma. The diagnosis of pneumoconiosis of the silicotic type was sustained. The occupational risk linked to using this type of wood should be understood and the need to take protective measures for the employees concerned.

Adult↗
PubMed1993

Metabolism, thermogenesis and daily rhythm of body temperature in the wood lemming, Myopus schisticolor.

Wood lemmings (Myopus schisticolor) were captured during their autumnal migration in September and October. The animals were maintained at 12 degrees C and under 12L:12D photoperiod. Basal metabolic rate and thermogenic capacity of the wood lemming were studied. Basal metabolic rate was 3.54 ml O2.g-1.h-1, which is 215-238% of the expected value. The high basal metabolic rate seems to be typical of rodents living in high latitudes. The body temperature of the wood lemming was high (38.0-38.8 degrees C), and did not fluctuate much during the 24-h recording. The high basal metabolic rate and the high body temperature are discussed with regard to behavioural adaptation to a low-quality winter diet. Thermogenic capacity, thermal insulation and non-shivering thermogenesis of the wood lemming displayed higher values than expected: 53.0 mW.g-1, 0.53 mW.g-1.degrees C-1 and 53.2 mW.g-1, respectively. Brown adipose tissue showed typical thermogenic properties, although its respiratory property was fairly low, but mitochondrial protein content was high compared to other small mammals. The 24-h recording of body temperature and motor activity did not reveal whether the wood lemming is a nocturnal animal. Possibly, the expression of a circadian rhythm was masked by peculiar feeding behaviour. It is concluded that the wood lemming is well adapted to living in cold-temperature climates.

Acclimatization↗
PubMed2001

The Influence of Competition between Tropical Fungi on wood colonization in Streams.

Wood blocks inoculated with fungi were placed in a stream in order to investigate their interactions with the native mycota. Wood blocks were inoculated with single or paired isolates of tropical fungi, whereas no fungi were inoculated onto controls. After 3 months, the wood blocks were collected and the number of newly colonizing fungi were identified. More fungi were found on uninoculated than on wood blocks pre-inoculated with Chaetosphaeria sp. Neither Nais aquatica or Annulatascus velatisporus inhibited colonization when inoculated singly. However, in combination, they inhibited colonization by other fungi, indicating an interaction between the two species. Inoculated wood blocks were generally first colonized by hyphomycetes, with a low occurrence of ascomycetes. The study also showed that autoclaving wood for use in experiments affects the outcome of the experiments, i.e., affects the structure of the fungal community.

Journal Article↗
PubMed2006

Limited transfer of nitrogen between wood decomposing and ectomycorrhizal mycelia when studied in the field.

Transfer of (15)N between interacting mycelia of a wood-decomposing fungus (Hypholoma fasciculare) and an ectomycorrhizal fungus (Tomentellopsis submollis) was studied in a mature beech (Fagus sylvatica) forest. The amount of (15)N transferred from the wood decomposer to the ectomycorrhizal fungus was compared to the amount of (15)N released from the wood-decomposing mycelia into the soil solution as (15)N-NH(4). The study was performed in peat-filled plastic containers placed in forest soil in the field. The wood-decomposing mycelium was growing from an inoculated wood piece and the ectomycorrhizal mycelium from an introduced root from a mature tree. The containers were harvested after 41 weeks when physical contact between the two foraging mycelia was established. At harvest, (15)N content was analyzed in the peat (total N and (15)NH(4) (+)) and in the mycorrhizal roots. A limited amount of (15)N was transferred to the ectomycorrhizal fungus and this transfer could be explained by (15)NH(4) (+) released from the wood-decomposing fungus without involving any antagonistic interactions between the two mycelia. Using our approach, it was possible to study nutritional interactions between basidiomycete mycelia under field conditions and this and earlier studies suggest that the outcomes of such interactions are highly species-specific and depend on environmental conditions such as resource availability.

Basidiomycota↗
PubMed2006

Wood creosote prevents CRF-induced motility via 5-HT3 receptors in proximal and 5-HT4 receptors in distal colon in rats.

Wood creosote has been used as an herbal medicine against acute diarrhea caused by food poisoning and has an inhibitory effect on colonic motility and enterotoxin-induced ion secretion. Since no previous studies have examined the effects of wood creosote on stress-induced alteration of colonic motility, we examined the effects on the colonic motility altered by intracerebroventricular (i.c.v.) injection of corticotropin-releasing factor (CRF), which is a key mediator in responses to stress. We recorded motor activity in proximal and distal colon of unrestrained conscious rats via two manometory catheters. The frequencies of phase III-like contraction and the % motor indices in both proximal and distal colon were measured. At the same time the number of fecal pellets excreted was counted. I.c.v. injection of CRF increased the motor activity in both proximal and distal colon, and these effects were completely antagonized by i.c.v. injection of a selective CRF type 1 antagonist but not by a CRF type 2 antagonist. Changes in colonic motility induced by CRF were reversed by intravenously administered wood creosote. Intraluminal administration of the 5-HT(3) receptor antagonist granisetron, or the 5-HT(4) receptor antagonist SB 204070 blocked the increase in colonic motility induced by i.c.v. injection of CRF. Wood creosote prevented the increase in colonic motility induced by the 5-HT(3) receptor agonist SR57227A in the proximal colon, while it prevented the increase in colonic motility induced by the 5-HT(4) receptor agonist RS67506 in the distal colon. These results indicate that wood creosote prevents the increase in colonic motility induced by CRF via 5-HT(3) receptors in the proximal colon, and via 5-HT(4) receptors in the distal colon, suggesting that wood creosote might be useful to treat stress-induced diarrhea.

Animals↗
PubMed2006

Diversity and community structure of ectomycorrhizal fungi in a wooded meadow.

Wooded meadows are seminatural plant communities that support high diversity of various taxa. Due to changes in land use, wooded meadows have severely declined during the last century. The dominant trees in wooded meadows acquire mineral nutrients via ectomycorrhizal fungi. Using anatomotyping and sequencing of root tips, interpolation and extrapolation methods, we studied the diversity and community structure of ectomycorrhizal fungi in two soil horizons of both managed and forested parts of a wooded meadow in Estonia. Species of Thelephoraceae, Sebacinaceae and the genus Inocybe dominated the whole ectomycorrhizal fungal community of 172 observed species. Forested and managed parts of the wooded meadow harboured different communities of ectomycorrhizal fungi, whereas soil horizon had a negligible effect on the fungal community composition. Diverse soil conditions and host trees likely support the high richness of ectomycorrhizal fungi in the wooded meadow ecosystem. Direct sequencing integrated with interpolation and extrapolation methods are promising to identify the fungi at the species level and to compare species richness between communities of ectomycorrhizal fungi.

Agaricales↗
PubMed2002

Potential risk to wood storks (Mycteria americana) from mercury in Carolina Bay fish.

Carolina bays are freshwater wetlands that serve as important feeding habitats for the endangered wood stork (Mycteria americana). Water levels in these bays fluctuate greatly and tend to be acidic and rich in dissolved organic carbon (DOC), factors that favor mercury (Hg) methylation and bioaccumulation in fish. To assess potential risks to wood storks consuming mercury contaminated fish in bays, we sampled fish from 10 bays on the Savannah River Site (SRS), South Carolina, an area with documented use by wood storks. Whole body mercury concentrations in 258 fishes of three species (Erimyzon sucetta, Acantharchuspomotis and Esox americanus) commonly consumed by wood storks were determined. Risk factors for nestlings and free-ranging adults were calculated using published no and lowest observable adverse effect concentration (NOAEC and LOAEC) values for birds. Fish from higher trophic levels and those from wetlands with relatively shallow maximum depths and fluctuating water levels were more likely to exceed NOAEC and LOAEC values. Calculation of exposure rates of nestling wood storks indicated they are at highest risk during the first 10 days of the nestling period. These calculations suggest that there is potential concern for wood storks foraging in relatively shallow bays with fluctuating water levels, even though there is no obvious local source of mercury to these wetlands.

Animal Feed↗
PubMed1997

A new substance (Yoshixol) with an interesting antibiotic mechanism from wood oil of Japanese traditional tree (Kiso-Hinoki), Chamaecyparis obtusa.

1. A neutral wood oil was extracted from Chamaecyparis obtusa (Kiso-Hinoki), which has been trusted nationally and preserved historically in the central part of Japan (Kiso, Nagano). 2. Hinokitiol, or thujaplicin (C10H12O2), which has been believed to exist in Cupressaceae, was not found in this neutral wood oil. Some differences between the extracting processes of the natural products are discussed. 3. A new chemical substance (Yoshixol, 4,4-dimethyl-6-methylene-2-cyclohexen-1-one) was simulated by several criteria (details in the text) as a major candidate of the neutral wood oil from Chamaecyparis obtusa. Thus, Yoshixol was newly synthesized. 4. The antibiotic effects of hinokitiol, the neutral wood oil and Yoshixol on methicillin-resistant Staphylococcus aureus (MRSA) were examined bacteriologically and morphologically. 5. All of the aforementioned three test materials showed complete antibiotic effects on MRSA by the bacteriological examination. However, the morphological findings showed entirely different aspects of cell death. 6. Hinokitiol caused an aggregative, degenerative and/or necrotic aspect, but the neutral wood oil and Yoshixol produced characteristic aspects: separation of contacted cells, blebbing, bugging-like eruption, formation of granules and an extensive reduction of individual cell size of MRSA. 7. Yoshixol was able to enhance those antibiotic effects on MRSA distinctly more than the neutral wood oil. 8. Yoshixol also showed a strong antibiotic effect on Escherichia coli, Mycobacterium chelonei, Pseudomonas aureginosa and Candida albicans. Morphological observations of those bacilli after Yoshixol revealed characteristic aspects of separation of contacted cells, bugging-like swelling, granulation, ballooning and reduction of cell size. 9. A possible mechanism of Yoshixol is discussed in regard to a molecular orbital theory on the basis of its electron orbits and to a thermodynamic interaction with the prokaryotic cell membrane. On the basis of the molecular properties of Yoshixol, future biological interests and possible biological effects of Yoshixol are suggested.

Anti-Bacterial Agents↗
PubMed2002

Host specificity of Trypanosoma (Herpetosoma) species: evidence that bank voles (Clethrionomys glareolus) carry only one T. (H.) evotomys 18S rRNA genotype but wood mice (Apodemus sylvaticus) carry at least two polyphyletic parasites.

The strongest evidence for host specificity of mammalian trypanosomes comes from parasites of the subgenus Trypanosoma (Herpetosoma). Laboratory studies have shown that T. (Herpetosoma) species will not infect an alternative host. However, this has not been demonstrated in wild populations. We screened 560 bank voles (Clethrionomys glareolus) and 148 wood mice (Apodemus sylvaticus) for trypanosomes by PCR amplification of the 18S rRNA gene. In total, 109 (19%) bank voles and 12 (8%) wood mice were infected. A HaeIII restriction site was discovered that could be used to discriminate between T. (H.) evotomys of the bank vole and T. (H.) grosi of the wood mouse. All the parasites in the bank voles were identified as T. (Herpetosoma) evotomys by RFLP-PCR. Out of the 12 wood mouse infections 10 were due to T. grosi. Two of the wood mice were infected with parasites with a novel genotype that was most similar to those of T. evotomys and T. microti of voles. Fifty-six fleas collected from the rodents were also screened for trypanosomes; 9 were infected with T. evotomys and 1 with T. grosi. One of the fleas infected with T. evotomys was collected from a wood mouse.

Animals↗
PubMed2004

Wood density and anatomy of water-limited eucalypts.

We hypothesized that seedlings grown under water-limited conditions would develop denser wood than seedlings grown under well-watered conditions. Three Eucalyptus species (E. grandis Hill (ex Maiden), E. sideroxylon Cunn. (ex Woolls) and E. occidentalis Endl.) were grown in a temperature-controlled greenhouse for 19 weeks with watering treatments (well-watered and water-limited) applied at six weeks. The water-limitation treatment consisted of four drought cycles. Wood density increased by between 4 and 13% in the water-limited seedlings, but this increase was mainly due to extractive compounds embedded in the cell wall matrix. Once these compounds were removed, the increase was 0-9% and was significant for E. grandis only. Water-limitation significantly reduced mean vessel lumen area; however, this was balanced by a trend toward greater vessel frequency in water-limited plants, and consequently there was no difference in the proportion of stem area allocated to vessels. Conduit efficiency value was lowest in the water-limited plants, indicating that there was a cost in terms of stem hydraulic conductivity for decreasing vessel lumen area. Wood density was negatively correlated with vessel lumen fraction in well-watered plants, but this relationship broke down in the water-limited plants, possibly because of the significantly larger proportion of the stem taken up by pith in water-limited seedlings. Diurnal variation in leaf water potential was positively correlated with wood density in well-watered plants. This relationship did not hold in the water-limited plants owing to the collapse of the pressure gradient between soil and leaf. We conclude that drought periods of greater than 1 month are required to increase wood density in these species and that increases in wood density appear to result in diminished capacity to supply water to leaves.

Dehydration↗
PubMed1984

Screening wood decayed by white rot fungi for preferential lignin degradation.

A screening procedure in which scanning electron microscopy was used indicated that 26 white rot fungi selectively removed lignin from various coniferous and hardwood tree species. Delignified wood from field collections had distinct micromorphological characteristics that were easily differentiated from other types of decay. The middle lamella was degraded, and the cells were separated from one another. Secondary cell wall layers that remained had a fibrillar appearance. Chemical analyses of delignified wood indicated that the cells were composed primarily of cellulose. Only small percentages of lignin and hemicellulose were evident. Delignified wood was not uniformly distributed throughout the decayed wood samples. White-pocket and white-mottled areas of the various decayed wood examined contained delignified cells, but adjacent wood had a nonselective removal of lignin where all cell wall components had been degraded simultaneously. This investigation demonstrates that selective delignification among white rot fungi is more prevalent than previously realized and identifies a large number of fungi for use in studies of preferential lignin degradation.

Journal Article↗
PubMed1964

Degradation of Wood Preservatives by Fungi.

Wood-inhabiting fungi, not necessarily responsible for major decay, are shown to be capable of degrading a toxic compound into a less potent form, thus rendering it less effective in protecting wood from decay by less-tolerant basidiomycetous wood-destroyers. Sweetgum or pine sapwood blocks treated with preservatives (ammoniacal copper arsenate, fluor-chrome-arsenate-dinitrophenol, a creosote or pentachlorophenol) were exposed progressively to two different wood-inhabiting fungi with sterilization between the first and second exposure. The fungus in the first exposure was usually an Ascomycete or a Fungi Imperfecti-Chaetomium globosum, Phoma, Orbicula, Graphium, Pestalozzia, or Trichoderma species, isolated from wood below the ground. In one experiment, the fungus in the first exposure was a basidiomycete, Lenzites trabea or Polyporus versicolor. The second fungus, a prominent Basidiomycete-Coniophora puteana, Lentinus lepideus, or Lenzites trabea-was the bioassay fungus, since its purpose was to show whether the first fungus had degraded the preservative. Generally, the treated block, except where exposed to another fungus, remained virtually untouched by the bioassay fungus. Clearly, therefore, the first fungus had rendered the preservative ineffective but without appreciably decaying the wood itself Chemical analyses of treated blocks indicated that in the first exposure the fungi had substantially depleted sodium arsenate and pentachlorophenol.

Journal Article↗
PubMed2003

Multiple-dose escalation, safety, and tolerability study of wood creosote, the principal active ingredient of seirogan, an herbal antidiarrheal medication, in healthy subjects.

Seirogan, an herbal medicine containing wood creosote (CAS 8021-39-4), a mixture of simple phenolic compounds, has been marketed for the past century in Asia for the treatment of acute diarrhea and associated symptoms, such as abdominal discomfort and cramping. The present study was designed to assess the safety and tolerability of an anticipated acute antidiarrheal dosing regimen. Sixty healthy males were randomized into five groups of 12 subjects each (9 wood creosote; 3 placebo) to receive 45-, 90-, 135-, 180-, and 225-mg tablets every 2 hours for five doses. Serial sitting and standing vital signs, ECG rhythm strips, and continuous telemetry monitoring were obtained predose and for 24 hours after the first dose. Clinical laboratory tests and 12-lead resting ECGs were obtained predose and 24 hours postdose. Of the subjects, 27% (12/45) receiving wood creosote and 27% (4/15) receiving placebo reported adverse events. The most common adverse events were altered taste and somnolence, reported more often with 180- and 225-mg doses. Wood creosote had no clinically significant effects on vital signs, ECG intervals or interpretations, or clinical laboratory tests. No clinically significant or serious dysrhythmias were reported on continuous telemetry monitoring. It was concluded that oral doses of wood creosote 45 to 225 mg every 2 hours for up to five doses were safe and well tolerated in 45 healthy subjects. Wood creosote doses ranging from 45 to 135 mg per dose, which are commonly administered antidiarrheal doses in Asia, were associated with minimal side effects.

Administration, Oral↗