Genetic diversity and population structure of a rare flowering tree endemic to Appalachia, Stewartia ovata.

Stewartia ovata (cav.) Weatherby, commonly known as mountain stewartia, is an understory tree native to the southeastern United States (U.S.). This relatively rare species occurs in isolated populations in Virginia, Kentucky, Tennessee, North Carolina, South Carolina, Georgia, Alabama, and Mississippi. As a species, S. ovata has largely been overlooked, and limited information is available regarding its ecology, which presents obstacles to conservation efforts. Stewartia ovata has vibrant, large white flowers that bloom in summer with a variety of filament colors, suggesting potential horticultural traits prized by ornamental industry. However, S. ovata is relatively slow growing and, due to long seed dormancy, propagation is challenging with limited success rates. This has created a need to assess the present genetic diversity in S. ovata populations to inform potential conservation and restoration of the species. Here, we employ a genotyping-by-sequencing (GBS) approach to characterize the spatial distribution and genetic diversity of S. ovata in the southern Appalachia region of the eastern United States. A total of 4475 single nucleotide polymorphisms (SNPs) were identified across 147 individuals from 11 collection sites. Our results indicate low genetic diversity (He = 0.216), the presence of population structure (K = 2), limited differentiation (F ST = 0.039), and high gene flow (Nm = 6.16) between our subpopulations. Principal component analysis corroborated the findings of STRUCTURE, confirming the presence of two distinct S. ovata subpopulations. One subpopulation mainly contains genotypes from the Cumberland Plateau, Tennessee, while the other consists of genotypes present in the Great Smoky Mountain ranges in Tennessee, North Carolina, and portions of Nantahala, Chattahoochee-Oconee national forests in Georgia, highlighting that elevation likely plays a major role in its distribution. Our results further suggested low inbreeding coefficient (F IS = 0.070), which is expected with an outcrossing tree species. This research further provides necessary insight into extant subpopulations and has generated valuable resources needed for conservation efforts of S. ovata.

Closing the knowledge gap on the composition of the asbestos bodies.

Asbestos bodies (AB) form in the lungs as a result of a biomineralization process initiated by the alveolar macrophages in the attempt to remove asbestos. During this process, organic and inorganic material deposit on the foreign fibers forming a Fe-rich coating. The AB start to form in months, thus quickly becoming the actual interface between asbestos and the lung tissue. Therefore, revealing their composition, and, in particular, the chemical form of Fe, which is the major component of the AB, is essential to assess their possible role in the pathogenesis of asbestos-related diseases. In this work we report the result of the first x-ray diffraction measurements performed on single AB embedded in the lung tissue samples of former asbestos plant workers. The combination with x-ray absorption spectroscopy data allowed to unambiguously reveal that Fe is present in the AB in the form of two Fe-oxy(hydroxides): ferrihydrite and goethite. The presence of goethite, which can be explained in terms of the transformation of ferrihydrite (a metastable phase) due to the acidic conditions induced by the alveolar macrophages in their attempt to phagocytose the fibers, has toxicological implications that are discussed in the paper.

Malignant pleural mesothelioma in a female lion (Panthera leo).

An 18-year-old female lion (Panthera leo) was referred to the Department of Animal Pathology of the University of Turin (Italy). At necropsy, multiple nodular, 4-20-mm, confluent white firm nodules were scattered throughout the pleural surfaces of the thoracic wall and of the lungs. Histological lesions were represented by proliferations of papillary structures lined by cuboidal basophilic mesothelial cells with large, oval nuclei and abundant granular eosinophilic cytoplasm. Immunohistochemistry revealed immunoreactivity for pancytokeratin and vimentin. None of the cells expressed calretinin antigen. Asbestos fibers and asbestos bodies were not detected respectively by light microscopy and by Scanning Electron Microscope-Energy Dispersive Spectrometer investigations. On the contrary, chrysotile asbestos were identified in samples from shelter material. Histological and immunohistochemical findings were consistent with the diagnosis of an epithelial malignant mesothelioma. To our best knowledge, this is the first report of a pleural mesothelioma in a lion.

Mycophenolate mofetil and roscovitine decrease cyclin expression and increase p27(kip1) expression in anti Thy1 mesangial proliferative nephritis.

The response of mesangial cells to a phlogistic challenge includes cell proliferation and mesangial matrix expansion. Cell proliferation is a highly regulated process which includes enhancing factors such as cyclins, cyclin dependent kinases, and inhibitory proteins, such as p27(kip1). The aim of the study was to evaluate the effects of Mycophenolate mofetil (MMF), and roscovitine (R), on the cell cycle regulatory system when administered in the florid phase of the experimental model of mesangial proliferative nephritis induced by the anti Thy-1 antigen monoclonal antibody. Three days after nephritis induction, different groups were given MMF and R. Rats treated with MMF or R showed a slight decrease in mesangial proliferation and matrix expansion. Samples of cortical tissue were tested by 'real time' RT-PCR in order to study gene expression of cyclins B, D1, D2, D3, E, and the cyclin inhibitor p27(kip1). Localization of mRNA was evaluated by in situ hybridization. Real time RT-PCR analysis showed a significant decrease in cyclins B, D1, D2, and D3 in rats treated with either MMF or R as compared to controls. Both MMF and R treatment induced a significant increase in p27(kip1) mRNA expression. In situ hybridization showed a mesangial-endothelial expression pattern in glomeruli. The number of labelled cells per glomerulus, the number of positive glomeruli in each examined slide as well as cyclin D2 and D3 signal intensity was significantly lower in rats treated with MMF or R as compared to controls, whereas MMF or R treatment up-regulated p27(kip1) mRNA expression. Immunohistochemical evaluation of p27(kip1) aimed to examine the influence of MMF or R on protein expression confirmed up-regulation.

[Mineral fibers and bladder cancer. Morphological and minerological investigations in a subject without professional exposure]. / Fibre minerali e carcinoma vescicale. Indagine morfologica e mineralogica in un soggetto non professionalmente esposto.

It is confirmed that occupational and paraoccupational exposure to mineral fibres, particularly asbestos fibres, plays a fundamental role in the induction of lung cancer and pleural mesothelioma. The possible association with other human cancers (e.g. larynx cancer, gastro-intestinal cancer, uro-genital cancer and emolinfopoietic cancer) is not yet demonstrated, even if some mineral fibres are identified in tissues different from the lung ones, such as kidney, bladder, and some biological fluids (e.g. urine of subjects with occupational exposure to asbestos). The possibility of damage caused to tissues in consequence of exposure to low concentration of mineral fibres (e.g. environmental exposure) has still to be defined. In this work we report the results of a mineralogical study by means of scanning electron microscopy with microprobe of a case of bladder cancer in a subject without professional exposure to mineral fibres where asbestos bodies are identified by optical microscopy.

[Aggressive digital papillary adenocarcinoma: a case report]. / Adenocarcinoma digitale papillare aggressivo: descrizione di un caso.

AIM: We describe a case of Aggressive Digital Papillary Adenocarcinoma, a rare skin neoplasm with acral location. RESULTS: The patient, a 66 year old man, presented with an ulcerated mass of the fifth toe of the left foot, 4.4 cm in size. Histologically the tumour was characterized by a solid-cystic structure, with extensive papillary component, comedo necrosis and focal eccrine differentiation. Immunohistochemistry showed diffuse positivity for cytokeratins AE1/AE3 and 7, and, focal staining for Muscle Specific Actin, Vimentin and EMA. Chest CT scan showed the presence of a single pulmonary node, whose cytological features were consistent with a metastatic disease. CONCLUSIONS: The clinico-pathological features of the present are similar to those previously reported in the literature and confirms the aggressive nature of this neoplasm.

Mapping airborne lead contamination near a metals smelter in Derbyshire, UK: spatial variation of Pb concentration and 'enrichment factor' for tree bark.

Samples of tree bark, collected over an area of 4 km2 near a small non-ferrous metals smelter in Derbyshire, UK, were analysed for Pb and Al by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Analyte concentrations varied from 100 to over 25,000 mg kg-1 and 5 to 1000 mg kg-1, respectively. While an inverse relationship between the Pb content of bark and distance from the smelter was observed, concentrations fluctuated, indicating a variability in sample collection efficiency and problems in standardization. To overcome these effects, the Pb/Al ratio was calculated and subsequently normalized to the average Pb/Al ratio in continental crust (0.00015). On the assumption that the time-averaged concentration of airborne Al in this area is relatively constant and derived principally from wind-blown soil, the measurement represents an anthropogenic 'enrichment factor' (PbEF). PbEF varied from 10,000 to over 1,000,000, and showed a consistent reduction with distance from the smelter. Isolines of equal PbEF were subsequently defined on a map of the sampled area. Pb contamination was greatest in the vicinity of the smelter, and preferential transport along the NW-SE axis of the valley (in which the smelter is situated) was observed. The use of enrichment factors thus proved valuable in defining the relative level of airborne-derived Pb pollution.

Airborne uranium contamination--as revealed through elemental and isotopic analysis of tree bark.

A new strategy for characterisation of airborne uranium contamination based on ICP mass spectrometric analysis of tree bark is described. The uranium content of tree barks (50 samples) obtained from diverse locations (remote, rural, industrial) varied over almost four orders of magnitude (0.001-8.3 micrograms/g U) with maximum concentrations recorded in the vicinity of a nuclear fuel fabrication plant (0.70-8.3 micrograms/g U). Elevated concentrations were also observed near a coal-fired power station (0.25-0.38 microgram/g U). Isotopic analysis revealed significant deviation from the natural uranium isotope ratio (235U/238U, 0.00725) at four nuclear installations (235U/238U, 0.0055-0.0097). These findings indicate that tree bark serves as an effective biomonitor for uranium and, with isotopic analysis, discrimination between nuclear and non-nuclear emissions is realised.

The potential of elemental and isotopic analysis of tree bark for discriminating sources of airborne lead contamination in the UK.

Samples of tree bark, which accumulate airborne material, were collected from seven locations in the UK to provide an indication of the magnitude and source of lead pollution. Measurement of the Pb content and 206/207Pb stable isotope ratio by inductively coupled plasma mass spectrometry revealed significant differences between the sites. The concentration of Pb varied over almost four orders of magnitude from 7.2 to 9,600 micrograms g-1, the maximum values being found near a 'secondary' Pb smelter. The 206/207Pb isotope ratios varied from 1.108 +/- 0.002 to 1.169 +/- 0.001. The lowest Pb concentrations and highest isotope ratios were detected in bark samples from the Scilly Isles, reflecting the low-level of industry and road traffic. In contrast, samples obtained from a city centre (Sheffield) and near a motorway (M1) contained 25-46 micrograms g-1 Pb and recorded the lowest 206/207Pb ratios. Higher concentrations in the vicinity of a coal-fired power station recorded a 206/207Pb ratio of 1.14, suggesting a significant contribution from fly-ash. The relative contribution of lead from petrol (206/207Pb = 1.08) and other sources such as coal (206/207Pb = 1.18) were thus estimated using mass balance equations. Tree bark near the lead smelter recorded an intermediate 206/207Pb ratio of 1.13 reflecting the processing of material of mixed origin.

Characterisation of airborne uranium and thorium contamination in northern England through measurement of U, Th and 235U/238U in tree bark.

Samples of tree bark were collected from four locations in Northern England (a typical rural site, a coal-fired power station, a uranium (isotopic) enrichment plant and a nuclear fuel fabrication facility), to assess the nature and extent of airborne uranium and thorium contamination. The U and Th concentrations of bark were determined by inductively coupled plasma mass spectrometry after conventional nebulisation of bark digests, whilst measurement of 235U/238U isotopic ratio utilised high efficiency nebulisation. Uranium concentrations varied between and within the sites (range, 0.01-12 micrograms g-1), with maximum values recorded within 1 km of the nuclear fuel fabrication plant (Springfields). In comparison, the concentration of Th in bark was low (mean, 0.018 microgram g-1) at all sites with the exception of the area affected by coal combustion (0.2-0.8 microgram g-1). The U/Th ratio varied from 0.5 to 3900 compared with the average crustal ratio of 0.3. Low values (< 2) were recorded at the 'coal' and 'rural' sites whilst Capenhurst and Springfields showed high values indicating the relative magnitude of uranium elevation. Significant enrichment of the natural 235U/238U ratio (0.00725) was observed near the nuclear installations, in particular, the enrichment plant (Capenhurst).

Airborne emission of enriched uranium at Tokai-mura, Japan.

A new strategy for characterisation of airborne uranium contamination based on elemental/isotopic analysis of tree bark is described. Bark samples collected at Tokai-mura (Japan) were subjected to high sensitivity ICP mass spectrometric analysis; for control purposes, samples from the remote Yakushima island (Southern Japan) and central Tokyo were also analysed. The uranium contents of tree bark for Tokyo and Yakushima were of similar magnitude to that at Tokai-mura (U, 0.01-1.0 microg/g - all samples), however, there were marked differences in isotope ratio values between the sites. Whereas natural uranium isotope ratio values (235U/238U, 0.0072) were observed for Yakushima and Tokyo, non-natural and natural signatures (235U/238U, 0.00697-0.01448) were realised at Tokai-mura. These findings are consistent with the release of enriched uranium at Tokai-mura.

Isotopic analysis of uranium in tree bark by ICP mass spectrometry: a strategy for assessment of airborne contamination

Isotopic analysis of uranium in tree bark by ICP mass spectrometry is proposed as a new measurement strategy for monitoring airborne contamination and for discrimination of nuclear and nonnuclear emission sources. A quadrupole-based ICP mass spectrometer equipped with a microconcentric nebulizer and membrane desolvator was used to provide high-sensitivity measurement. The limit of detection for uranium (238U) was 0.004 ng L(-1). Measurement precision (235U/238U) was between 0.2 and 0.5% RSD for isotopic SRMs (U005 and U015; concentration, 1 microg L(-1)) and ranged from 0.4 to 3.1% RSD for tree bark extracts (U concentration, 0.03-0.08 microg L(-1)). Bark samples collected from the Peak District National Park in Derbyshire (U.K.) exhibited a natural 235U/238U isotope ratio value (0.0072) whereas samples from Sellafield, West Cumbria (U.K.) showed depletion in 235U (235U/238U = 0.0053-0.0064).

Determination of trace elements including platinum in tree bark by ICP mass spectrometry.

The increasing emission of Pt-group metals from automobile catalytic converters requires the development of highly sensitive procedures for ultratrace analysis of environmental and biological systems. Tree bark, located close to motorway or industrial areas, was utilised as a substrate for collection of airborne particulate matter and samples after digestion (microwave assisted dissolution with HNO3 and HCl) were analysed by ICP mass spectrometry. The study targeted Pt and other metallic contaminants and involved analysis of some 57 tree bark samples using both quadrupole and double-focusing sector field ICP mass spectrometers. Detection limits for platinum determination in tree bark were 0.03 ng/g (DF-ICP-MS) and 0.2 ng/g (ICP-QMS). The platinum content of the bark samples ranged from 0.07-5.4 ng/g.

Role of iron in asbestos-body-induced oxidant radical generation.

Asbestos bodies (AB) were harvested from human lung tissue digests and isolated from uncoated asbestos fibers. Samples containing 1000 AB were added to a reactive solution to investigate the ability of AB to oxidize deoxy-D-ribose and generate reactive oxygen species (ROS) in the presence of ascorbate and hydrogen peroxide as determined by formation of thiobarbituric acid (TBA)-reactive products. Three types of asbestos fibers were tested for comparison, since they are known to be able to produce ROS. The absorbance values measured with 1000 AB were significantly higher than those observed with 1000 fibers of the three types of asbestos. Since in our reaction system the only source of transition metals was the iron-rich AB, data suggest iron derived from the ferritin coating of AB was involved in oxidant generation. Addition of iron to AB enhanced TBA-reactive product formation, while chelation of Fe with deferoxamine reduced this reaction. Hydroxyl radical scavengers 1,3-dimethyl-2-thiourea (DMTU) and mannitol (MN) also effectively blocked TBA-reactive product generation. Data indicate the importance of Fe in AB-induced oxidant damage. With the addition of polymorphonuclear leukocytes (PMN) to AB, incubation in the reactive solution gave very high amounts of TBA-reactive products, but using a reactive solution devoid of ascorbate, very low amounts of TBA-reactive products were generated. In the latter condition, the superoxide of cell membranes probably reduced and removed iron from AB-coating ferritin, but less effectively than ascorbate. Further after the possible reoxidation of Fe2+, Fe3+ could be coordinated by lactoferrin. Since such availability of reductant is never approached in living systems, the iron in the AB coating is unlikely to function as a catalyst of Fenton-type reactions in vivo.

Asbestos lung burden and asbestosis after occupational and environmental exposure in an asbestos cement manufacturing area: a necropsy study.

OBJECTIVE: The largest Italian asbestos cement factory had been active in Casale Monferrato until 1986: in previous studies a substantial increase in the incidence of pleural mesothelioma was found among residents without occupational exposure to asbestos. To estimate exposure to asbestos in the population, this study evaluated the presence of histological asbestosis and the lung burden of asbestos fibres (AFs) and asbestos bodies (ABs). METHODS: The study comprises the consecutive series of necropsies performed at the Hospital of Casale Monferrato between 1985 and 1988. A sample of lung parenchima was collected and stored for 48 out of 55 necropsies. The AF concentration was measured with a TEM electron microscope with x ray mineralogical analysis. The ABs were counted and fibrosis evaluated by optical microscopy. The nearest relative of each subject was interviewed on occupational and residential history. Mineralogical and histological analyses and interviews were conducted in 1993-4. RESULTS: Statistical analyses included 41 subjects with AF, AB count, and interview. Subjects without occupational exposure who ever lived in Casale Monferrato had an average concentration of 1500 AB/g dried weight (gdw); Seven of 18 presented with asbestosis or small airway lung disease (SAL). G2 asbestosis was diagnosed in two women with no occupational asbestos exposure. One of them had been teaching at a school close to the factory for 12 years. Ten subjects had experienced occupational asbestos exposure, seven in asbestos cement production: mean concentrations were 1.032 x 10(6) AF/gdw and 96,280 AB/gdw. Eight of the 10 had asbestosis or SAL. CONCLUSION: The high concentration of ABs and the new finding of environmental asbestosis confirm that high asbestos concentration was common in the proximity of the factory. Subjects not occupationally exposed and ever living in Casale Monferrato tended to have higher AB concentration than subjects never living in the town (difference not significant). The concentrations of ABs and AFs were higher than those found in other studies on nonoccupationally exposed subjects.

[Lung cancers attributable to asbestos on a pathological basis]. / Carcinomi polmonari attribuibili ad asbesto su base patologica.

More than 1,000 asbestos bodies/gram dry weight (AB/gdw) were found by light microscopy in lung tissues, out of 429 non selected cases of pulmonary carcinoma (264 from surgery and 165 from autopsy). Asbestosis was detected by histology in 28% of the cases with AB > 1,000/gdw (in 19% of the surgical cases, and in 38% of the autopsy cases). A proportion of 4% of the total cases may be related to asbestos exposure.

Family treatment of symptomatic children with Helicobacter pylori infection.

BACKGROUND: Familial clustering of Helicobacter pylori infection has been reported. We tested the hypothesis that simultaneously treating all Helicobacter pylori positive family contacts of infected symptomatic children results in lower treatment failure. METHODS: Relatives of 47 children (index) with Helicobacter pylori gastritis had endoscopy to assess prevalence of infection in first degree cohabiting relatives. Controls included 60 children with dyspepsia and Helicobacter pylori gastritis whose infected family contacts were not treated. Index children, siblings younger than 18 years of age and control children received a 2-week course of amoxicillin and tinidazole. Parents of index children and their siblings over 18 years of age received a 2-week course of Colloidal Bismuth Subcytrate and tinidazole. The eradication rate in index children and their relatives was compared to controls whose infected family contacts were not treated. RESULTS: Helicobacter pylori was found in 67% of 31 siblings younger than 18, in 82% of 22 siblings older than 18 years, and in 87% of 92 parents. Endoscopy, repeated four to six weeks after the end of treatment, showed Helicobacter pylori eradication in 94% of children and siblings younger than 18, and in 70% of parents and siblings over 18 years in the family treatment group, compared with 75% of control children (p < .01). CONCLUSIONS: The high prevalence of the infection in family members suggests that person-to-person spread of Helicobacter pylori takes place. Furthermore our results show that if (or when) required, simultaneous treatment given to the whole family results in lower treatment failure, since it may promote compliance to treatment.

Lung adenocarcinoma and indicators of asbestos exposure.

A case-control study was carried out on 145 male lung-cancer patients diagnosed at autopsy and 178 controls, in order to investigate the relationship between asbestos exposure and the cell type of pulmonary carcinoma. Adenocarcinomas (AD) were individually matched with other cell types and with controls. The relative risk (RR) of developing AD in relation with lung asbestos body (AB) content as the exposure indicator was calculated by using logistic-regression analysis for matched sets. Two cutoff levels, 1,000 and 10,000 asbestos bodies per gram dry weight (AB/gdw), were used in the analysis. In addition, AB counts were treated as a continuous variable (log AB+I). A significant association was found between AD and asbestos exposure, using levels and logarithmic transformation. However, an association of asbestos exposure with cell types other than AD could not be ruled out.

Ostial stenosis of the left main coronary artery in a young woman 10 years after radiation therapy.

A 26-year-old woman developed critical stenosis of the left main coronary artery 10 years after radiation treatment for Hodgkins disease. She was operated on but died in the immediate postoperative period. At autopsy the pathological findings were indistinguishable from those described in "typical" atherosclerotic plaques.

Malignant peritoneal mesothelioma in a 17-year-old boy with evidence of previous exposure to chrysotile and tremolite asbestos.

We describe a case of malignant peritoneal mesothelioma arising in a 17-year-old boy. The diagnosis was based on a comprehensive study including light microscopy, histochemistry, immunohistochemistry, evaluation of the clinical course, and autopsy examination. Analytical transmission electron microscopy showed a concentration of 510,000 asbestos fibers/g dry lung tissue. The fibers were represented by chrysotile (62%) and tremolite (38%) asbestos. About 40% of the total fibers were longer than 5 microns. The presence of tremolite fibers was probably due to environmental exposure to contaminated cosmetic talc. This is the first reported case of pathologically proven exposure to asbestos dust in malignant mesothelioma of childhood and adolescence.