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PubMed1982

Single-cell protein production in alkaline mesquite wood extracts.

A nine-member, mixed, cellulolytic, bacterial culture was used to evaluate the effects of sodium hydroxide normality, length and temperature of treatment, and the ratio of volume of alkali to mesquite wood on the suitability of alkali mesquite wood extractives as nutrients for bacterial growth. The presence or absence of air during the extraction process did not significantly affect results. The amount of lignin extracted and the total loss in weight of the wood during extraction were correlated to both alkali concentration and temperature. Neutralized extracts supported bacterial growth; growth was inversely related to the final salt concentration of the neutralized extract. Deionized extracts were superior to acid-neutralized extracts for the support of bacterial growth. The optimum conditions for extraction were 2.5 N NaOH at 30 degrees C for 12 h. The study demonstrated that nutrients as well as growth inhibitory compounds are released from wood by alkali treatment. This study of alkali wood extracts and the previous study of washed alkali treated wood residues provide a data base for the optimization of alkali treatments of hard woods that are to be used as nutrients for the growth of cellulolytic cultures.

Journal Article↗
PubMed1994

Pyranose Oxidase, a Major Source of H(2)O(2) during Wood Degradation by Phanerochaete chrysosporium, Trametes versicolor, and Oudemansiella mucida.

The production of the H(2)O(2)-generating enzyme pyranose oxidase (POD) (EC 1.1.3.10) (synonym, glucose 2-oxidase), two ligninolytic peroxidases, and laccase in wood decayed by three white rot fungi was investigated by correlated biochemical, immunological, and transmission electron microscopic techniques. Enzyme activities were assayed in extracts from decayed birch wood blocks obtained by a novel extraction procedure. With the coupled peroxidase-chromogen (3-dimethylaminobenzoic acid plus 3-methyl-2-benzothiazolinone hydrazone hydrochloride) spectrophotometric assay, the highest POD activities were detected in wood blocks degraded for 4 months and were for Phanerochaete chrysosporium (149 mU g [dry weight] of decayed wood), Trametes versicolor (45 mU g), and Oudemansiella mucida (1.2 mU g), corresponding to wood dry weight losses of 74, 58, and 13%, respectively. Mn-dependent peroxidase activities in the same extracts were comparable to those of POD, while lignin peroxidase activity was below the detection limit for all fungi with the veratryl alcohol assay. Laccase activity was high with T. versicolor (422 mU g after 4 months), in trace levels with O. mucida, and undetectable in P. chrysosporium extracts. Evidence for C-2 specificity of POD was shown by thin-layer chromatography detection of 2-keto-d-glucose as the reaction product. By transmission electron microscopy-immunocytochemistry, POD was found to be preferentially localized in the hyphal periplasmic space of P. chrysosporium and O. mucida and associated with membranous materials in hyphae growing within the cell lumina or cell walls of partially and highly degraded birch fibers. An extracellular distribution of POD associated with slime coating wood cell walls was also noted. The periplasmic distribution in hyphae and extracellular location of POD are consistent with the reported ultrastructural distribution of H(2)O(2)-dependent Mn-dependent peroxidases. This fact and the dominant presence of POD and Mn-dependent peroxidase in extracts from degraded wood suggest a cooperative role of the two enzymes during white rot decay by the test fungi.

Journal Article↗
PubMed1992

Mycobacteria in Crohn's disease: DNA probes identify the wood pigeon strain of Mycobacterium avium and Mycobacterium paratuberculosis from human tissue.

Mycobacterium paratuberculosis is known to cause Johne's disease, a granulomatous ileitis in ruminants, and may be involved in some cases of Crohn's disease. Like M. paratuberculosis, the wood pigeon strain of Mycobacterium avium may also show mycobactin dependence on primary isolation that is attenuated on further subculturing. A wood pigeon strain, M. avium restriction fragment length polymorphism (RFLP) type A/I, is also capable of causing granulomatous ileitis in experimental animal models but is not known to cause disease in humans. M. avium RFLP type A is associated with disease in immunocompromised hosts. Three DNA probes, pMB22 and the two subclones pMB22/S4 and pMB/S12, were found to be capable of distinguishing among M. paratuberculosis, M. avium type A, and M. avium type A/I (wood pigeon strain) on the basis of RFLPs. These DNA probes were used to identify two mycobacterial isolates (M. paratuberculosis and M. avium type A/I, wood pigeon strain) derived from the intestinal tissues of two patients with Crohn's disease. In addition, the wood pigeon strain of M. avium was identified from a patient with ulcerative colitis, and M. avium RFLP type A was identified from a patient with colonic carcinoma. This is the first time that M. avium A/I (wood pigeon strain) is known to have been isolated from human tissue. There are too few isolates to speculate about the etiological significance of mycobacteria and inflammatory bowel disease, but it is reasonable to conjecture that M. paratuberculosis may be responsible for some cases of Crohn's disease and that the wood pigeon strain of M. avium may also be an inflammatory bowel disease pathogen in humans.

Crohn Disease↗
PubMed1999

Dusky-footed wood rats (Neotoma fuscipes) as reservoirs of granulocytic Ehrlichiae (Rickettsiales: Ehrlichieae) in northern California.

Dusky-footed wood rats (Neotoma fuscipes) and Peromyscus sp. mice (P. maniculatus and P. truei) were collected from one site in Placer County, one site in Santa Cruz County, and two sites in Sonoma County in northern California. Serum or plasma samples from 260 rodents were tested for antibodies to the agent of human granulocytic ehrlichiosis. Of these, samples from 25 wood rats (34% of those tested) and 10 (8%) Peromyscus sp. mice were found to be seropositive, but only those from one site. PCR assays targeting the groESL heat shock operon were conducted on all seropositive specimens and a subset of seronegative blood specimens. Ehrlichial DNA was identified in 17 (68%) of the 25 seropositive wood rat blood samples and in 1 of the 10 (10%) Peromyscus sp. specimens. None of 40 seronegative blood samples was PCR positive. Both seropositive and PCR-positive animals were collected during each trapping period. One male tick out of 84 Ixodes pacificus adults collected was PCR positive; samples of Dermacentor occidentalis nymphs and adults were negative. Nucleotide sequences of amplicons from three wood rat blood specimens and from the single PCR-positive tick differed by one and two bases, respectively, from a sequence previously obtained from Ehrlichia equi. At one site in Sonoma County, wood rats had a concurrent high prevalence of seropositivity and PCR positivity, while other sigmodontine rodents collected at the site were only occasionally infected. We suggest that dusky-footed wood rats serve as reservoirs of granulocytic ehrlichial agents in certain areas of northern California. The tick species involved in the transmission of granulocytic ehrlichiae among wood rats remains unknown.

Animals↗
PubMed2001

Effect of gonadotrophins on the ovarian interstitial tissue of the wood mouse, Apodemus sylvaticus.

The ovarian interstitial tissue of the wood mouse (Apodemus sylvaticus) is extensively developed. The effect of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) on ovarian interstitial tissue was investigated in wood mice from a laboratory stock. The tissue was assessed by measuring the relative size of the cells, cell nucleus diameter and (in adults) nuclear shape. Hormone-treated wood mice had larger interstitial cells and larger cell nuclei than untreated animals. In addition, the cell nuclei of adult hormone-treated wood mice had a smooth round or oval outline, whereas those of untreated animals had an irregular outline with spiky projections. Electron microscopy showed that the irregular spiky outline of the cell nuclei in untreated wood mice was caused by distortions of the nuclear membrane by a large number of intracellular lipid droplets; the droplets were less abundant in the hormone-treated animals. These experiments indicate that the cells of the interstitial tissue of the wood mouse are under the control of gonadotrophins, and that these cells are likely to be a site of the synthesis and release of steroid hormones. The methods used in this study to assess the state of the cells could be applied to animals from the field to investigate the role of interstitial tissue in the reproductive biology of wood mice.

Aging↗
PubMed1997

Haemoproteus greineri in wood ducks from the Atlantic flyway.

Thin smears of blood were examined from 157 wood ducks (Aix sponsa) trapped at Savannah National Wildlife Refuge (South Carolina, USA) and Harris Neck National Wildlife Refuge (Georgia, USA) during spring and summer, 1994 and 1995. Thirteen wood ducks (8%) were infected with blood parasites. Eleven of these birds were infected with Haemoproteus nettionis, seven with Leucocytozoon simondi, and five with unidentified microfilariae. Additionally, eight wood ducks (5%) were infected with Haemoproteus greineri. This is the first record of H. greineri in anatids trapped along the Atlantic Flyway south of Labrador and the first record of this species in wood ducks. To further characterize the distribution of H. greineri in the wood duck, blood smears were examined from hatching year ducks trapped at 10 different Atlantic flyway locations during spring and summer, 1980 to 1983. Haemoproteus greineri was found in wood ducks trapped in all 10 locations which extend from 46 degrees N latitude in New Brunswick to 37 degrees N latitude in Virginia. These findings indicate that H. greineri is not exclusively boreal in distribution, but also is found, at least in wood ducks, along much of the Atlantic Flyway.

Animals↗
PubMed2005

Wood dust exposure and the association with lung cancer risk.

BACKGROUND: Wood dust was designated as a human carcinogen based on increased sinus and nasal cancer rates among exposed workers. However, data on an association with lung cancer have been inconclusive. METHODS: Self-reported wood dust exposure was compared between 1,368 lung cancer patients and 1,192 cancer-free adults, in a lung cancer case-control study. Epidemiological information was collected through a detailed personal interview. RESULTS: Using several definitions of wood dust exposure we consistently observed statistically significant elevated adjusted risk estimates; for example, the adjusted odds ratio (OR) for combined wood dust related occupations and industries was 3.15 (95% confidence intervals (CI) 1.45-6.86) and for an overall summary exposure measure it was 1.60 (95% CI 1.19-2.14). The association was maintained when stratified by histopathological type. Among those exposed to cigarette smoke and wood dust, 21% of the cases were attributable to biologic interaction. CONCLUSIONS: Wood dust exposure is a potential risk factor for lung cancer.

Air Pollutants, Occupational↗
PubMed1993

Genotoxic effects of subacute treatments with wood dust extracts on the nasal epithelium of rats: assessment by the micronucleus and 32P-postlabelling.

Human exposure to wood dust has been epidemiologically linked to a number of enhanced incidences of various neoplasias, including those of the nose. Among different suspected woods, long-term exposure to the dust of beech (Fagus silvatica) is strongly associated with development of these tumors. Experimentally, it has been shown that a simple alcoholic extract of beech wood dust is mutagenic toward some bacteria and tumorigenic on mouse skin. For the present study, different groups of male Wistar rats were treated with aqueous, ethanol, or methanol extract of untreated beech wood dust via nasal drip at three concentrations for 48 h. Animals were killed 24 h after the last treatment and the nasal tissues were isolated to be examined for possible induction of micronuclei and DNA adducts. A clear dose-dependent increase in the number of micronuclei (P < 0.01) was observed after treatment of rats with each alcoholic extract of wood dust. In contrast, no DNA adducts could be detected with these extracts using the 32P-postlabelling technique. No increased number of micronucleated cells was found with solvents alone or with aqueous extract of dust. These data might support the early hypothesis that wood dust per se contains some in vivo genotoxic and thus possibly carcinogenic components extractable by an alcohol.

Animals↗
PubMed1988

Risks for respiratory and gastric cancer in wood-working occupations in Denmark.

Cases of cancer notified to the Danish Cancer Registry during the period 1970 to 1984 in the age groups 16 to 66 years have been linked to information on employment kept on file in the nationwide Supplementary Pension Fund since 1964. Industrial hygienists classified industrial groups as defined by the Pension Fund with regard to exposure to wood dust, and a list of industries with major exposure to wood dust was defined. The risk for cancer of the respiratory system and the gastrointestinal tract was evaluated by means of a proportional cancer incidence analysis. A fourfold increase in risk for sinonasal cancer was found among men involved in the manufacture of wooden furniture, and a twofold increase in risk for gastric cancer was seen in all of the component industries of basic wood-processing. In contrast, no excess of gastric cancer could be detected in men working in the manufacture of wooden building materials and wooden furniture, and a risk below unity was seen for those in carpentry and joinery. The elevated risk for gastric cancer in some wood-processing industries is probably due to social factors also common to men in agriculture and manufacturing. The absence of an increased risk for gastric cancer in trades in which a high risk for sinonasal cancer is seen indicates that wood dust is not of aetiological importance for gastric cancer. No excess of total lung cancer or of the adenocarcinoma subtype was seen in any of the wood-processing industries.

Denmark↗
PubMed2003

Biotechnology in the wood industry.

Wood is a natural, biodegradable and renewable raw material, used in construction and as a feedstock in the paper and wood product industries and in fuel production. Traditionally, biotechnology found little attention in the wood product industries, apart from in paper manufacture. Now, due to growing environmental concern and increasing scientific knowledge, legal restrictions to conventional processes have altered the situation. Biotechnological approaches in the area of wood protection aim at enhancing the treatability of wood with preservatives and replacing chemicals with biological control agents. The substitution of conventional chemical glues in the manufacturing of board materials is achieved through the application of fungal cultures and isolated fungal enzymes. Moreover, biotechnology plays an important role in the waste remediation of preservative-treated waste wood.

Adhesives↗
PubMed2005

Public perception as a barrier to introducing wood in rivers for restoration purposes.

Reintroduction of wood in rivers for restoration purposes is now recognized in a positive way by scientists. Nevertheless, the perception of wood in riverscapes is strongly affected by the socio-cultural environment. This cultural influence might explain why wood reintroduction is accepted and promoted in some regions of the world but not in others, despite the demonstrated ecological benefits. From an extensive student perception survey, we show that most of the groups from nine countries in the world considered riverscapes with wood to be less aesthetic, more dangerous, and needing more improvement than riverscapes without wood. By contrast, this way of thinking was not observed in Germany, Sweden, and Oregon (USA), where the first instances of wood reintroduction occurred.

Attitude↗
PubMed2004

Agrobacterium-mediated in vitro transformation of wood-producing stem segments in eucalypts.

The genetic manipulation of perennial woody tree species presents a range of additional challenges compared to that of annual weedy crop species. These include long generation times and reproductive cycle, the heterogeneity of plants under investigation and, when investigating wood properties, a number of physical and biochemical limitations to microscopical and molecular experimentation. The use of in vitro wood formation systems for molecular studies and Agrobacterium-mediated introduction of transgenes overcomes many of these obstacles. Using a commercially relevant Eucalyptus species as model organism, we demonstrate here that in vitro wood formation systems can be readily employed to introduce transgenes into growing wood-producing tissue, initially leading to frequent transient gene expression in a range of cell types. Stable transformation events were observed as sectors of transformed tissue derived from primary transformation events in individual cells. The usefulness of such systems for the analysis of gene function during the process of wood formation and wood quality determination, as well as for constructing developmental fate maps of cambial derivatives, is discussed.

Cells, Cultured↗
PubMed2003

Does tree diversity increase wood production in pine forests?

Recent experimental advances on the positive effect of species richness on ecosystem productivity highlight the need to explore this relationship in communities other than grasslands and using non-synthetic experiments. We investigated whether wood production in forests dominated by Aleppo pine (Pinus halepensis) and Pyrenean Scots pine (Pinus sylvestris) differed between monospecific and mixed forests (2-5 species) using the Ecological and Forest Inventory of Catalonia (IEFC) database which contains biotic and environmental characteristics for 10,644 field plots distributed within a 31,944 km(2) area in Catalonia (NE Spain). We found that in Pyrenean Scots pine forests wood production was not significantly different between monospecific and mixed plots. In contrast, in Aleppo pine forests wood production was greater in mixed plots than in monospecific plots. However, when climate, bedrock types, radiation and successional stage per plot were included in the analysis, species richness was no longer a significant factor. Aleppo pine forests had the highest productivity in plots located in humid climates and on marls and sandstone bedrocks. Climate did not influence wood production in Pyrenean Scots pine forests, but it was highest on sandstone and consolidated alluvial materials. For both pine forests wood production was negatively correlated with successional stage. Radiation did not influence wood production. Our analysis emphasizes the influence of macroenvironmental factors and temporal variation on tree productivity at the regional scale. Well-conducted forest surveys are an excellent source of data to test for the association between diversity and productivity driven by large-scale environmental factors.

Ecosystem↗
PubMed1994

Effects of wood and cotton smoke on the surface properties of pulmonary surfactant.

The effects of wood and cotton smoke and several known smoke components on the dynamic surface activity of pulmonary surfactant were characterized with a modified Wilhelmy balance. Surfactant was harvested by saline lavage from dog lungs, placed in the balance and a control surface tension/area isotherm (y-A) and surface tension at minimum area (control y/min = 6.6 +/- 1.6 dynes/cm) measured. Hysteresis area (HA), recruitment index (RI), and stability index (SI) were calculated. Following control measurements, smoke (wood or cotton) was gently blown over the surfactant in the balance. Similarly, each of the individual smoke components or Liquid smoke (prepared by bubbling wood smoke through saline) were injected onto the balance. Wood smoke significantly (P < 0.05) altered all surface properties measured, increasing ymin (22.0 +/- 1.6 dynes/cm) and decreasing HA, RI, and SI as compared to control; cotton smoke exposure had almost no effect on surfactant function. A supplementary dose of surfactant was added to the balance, following wood smoke exposure, which decreased ymin (9.4 +/- 2.6 dynes/cm, P = NS vs control) but not the other parameters to control. Acrolein, formaldehyde, and HCl had little effect on any of the surface properties measured whereas isobutyraldehyde and liquid smoke altered the y-A curve but did not increase ymin. These data demonstrate that wood but not cotton smoke inhibit surfactant function, however, surfactant function can be restored, following deactivation by smoke, suggesting that surfactant replacement therapy for victims of severe smoke inhalation may be of benefit.

Animals↗
PubMedDate not supplied

Contribution of wood stoves and fire places to mutagenic activity of airborne particulate matter inside homes.

Wood combustion produces compounds that are mutagenic in the Salmonella/microsome assay. As combustion products can be emitted in the home and the use of wood as a residential energy source is growing, an impact on human health might be of concern. In this study experiments were carried out to determine the contribution of wood combustion in stoves and fire places to indoor mutagenic activity under normal living conditions. Airborne particles from living rooms which were heated by stoves, or by fire places, and from outdoors were collected simultaneously. In each room two samples were collected during two consecutive weeks: one week the room was heated by central heating, the other week by wood combustion. Sampling took place in a total of 24 homes. Methanol extracts of the samples were tested in the Salmonella/mammalian microsome assay. Results show that mutagenic activity of outdoor air exceeds indoor mutagenicity. At the same time a correlation is found between in- and out-door mutagenicity, both with and without S9. However, a large difference is found between the ratio -S9/+S9 of in- and out-door mutagenic activity. Systematic differences in the ratio -S9/+S9 between control and experimental conditions are not observed. The use of wood stoves caused an increase of indoor mutagenicity in 8 out of 12 homes. It could be concluded that the use of an open fire consistently leads to an increase of mutagenic activity. This increase was caused by wood combustion products.

Air Pollutants↗
PubMed2004

Mechanical properties and decay resistance of wood-polymer composites prepared from fast growing species in Turkey.

Some mechanical properties of wood-polymer composites from maritime pine (Pinus pinaster Ait.) and poplar (Populus x. euramericana cv. I-214) wood were investigated. Three different monomers; styrene (ST), methyl methacrylate (MMA) and styrene/methyl methacrylate (ST/MMA) mixture were used in preparation of wood-polymer composites (WPCs). Full-loading (FL), half-loading (HL) and quarter-loading (QL) were used as polymer content levels. Untreated pine and pine-polymer composite samples were tested in compression strength parallel to grain and static bending strength. WPCs mechanical properties increased compared to untreated wood. The polymer had greater effect on the strengths of the ST/MMA treated pine than on the ST and MMA treated pine samples. Increasing of the mechanical properties should improve the structural competitiveness of WPCs made from fast growing-low density woods. Weight losses due to fungal attack for pine and poplar-polymer composites were also determined. Although polymers at full and half loading levels helped decreasing weight losses due to both fungi for each wood species, weight losses were still found to be higher.

Compressive Strength↗
PubMed2006

Modification of wood with isopropyl glycidyl ether and its effects on decay resistance and light stability.

China fir (Cunninghamia lanceolata var. lanceolata) and maple (Acer sp.) wood were etherified with isopropyl glycidyl ether and the decay resistance and light stability of the modified wood were assessed. CP/MAS (13)C NMR and FT-IR analyses indicated that new ether bonds containing isopropyl groups formed after reacting wood with isopropyl glycidyl ether. Modified wood samples were very resistant to decay when exposed to brown-rot fungus Laetiporus sulphureus or white-rot fungus Lenzites betulina for 60 days in the soil-block test. The isopropyl glycidyl ether treatment of wood was effective in decreasing formation of phenoxyl radicals upon UV irradiation and thus protecting wood from photodiscoloration.

Acer↗
PubMedDate not supplied

Lignification and tension wood.

Hardwood trees are able to reorient their axes owing to tension wood differentiation. Tension wood is characterised by important ultrastructural modifications, such as the occurrence in a number of species, of an extra secondary wall layer, named gelatinous layer or G-layer, mainly constituted of cellulose microfibrils oriented nearly parallel to the fibre axis. This G-layer appears directly involved in the definition of tension wood mechanical properties. This review gathers the data available in the literature about lignification during tension wood formation. Potential roles for lignin in tension wood formation are inferred from biochemical, anatomical and mechanical studies, from the hypotheses proposed to describe tension wood function and from data coming from new research areas such as functional genomics.

Biomechanical Phenomena↗