High diversity and widespread occurrence of mitotic spore mats in ectomycorrhizal Pezizales.

Fungal mitospores may function as dispersal units and/ or spermatia and thus play a role in distribution and/or mating of species that produce them. Mitospore production in ectomycorrhizal (EcM) Pezizales is rarely reported, but here we document mitospore production by a high diversity of EcM Pezizales on three continents, in both hemispheres. We sequenced the internal transcribed spacer (ITS) and partial large subunit (LSU) nuclear rDNA from 292 spore mats (visible mitospore clumps) collected in Argentina, Chile, China, Mexico and the USA between 2009 and 2012. We collated spore mat ITS sequences with 105 fruit body and 47 EcM root sequences to generate operational taxonomic units (OTUs). Phylogenetic inferences were made through analyses of both molecular data sets. A total of 48 OTUs from spore mats represented six independent EcM Pezizales lineages and included truffles and cup fungi. Three clades of seven OTUs have no known meiospore stage. Mitospores failed to germinate on sterile media, or form ectomycorrhizas on Quercus, Pinus and Populus seedlings, consistent with a hypothesized role of spermatia. The broad geographic range, high frequency and phylogenetic diversity of spore mats produced by EcM Pezizales suggests that a mitospore stage is important for many species in this group in terms of mating, reproduction and/or dispersal.

Ectomycorrhizal fungal communities of oak savanna are distinct from forest communities.

Oak savanna is one of the most endangered ecosystems of North America, with less than 0.02% of its original area remaining. Here we test whether oak savanna supports a unique community of ectomycorrhizal fungi, a higher diversity of ectomycorrhizal fungi or a greater proportional abundance of ascomycete fungi compared with adjacent areas where the absence of fire has resulted in oak savanna conversion to oak forest. The overall fungal community was highly diverse and dominated by Cenococcum geophilum and other ascomycetes, Cortinarius, Russula, Lactarius and Thelephoraceae. Oak savanna mycorrhizal communities were distinct from oak forest communities both aboveground (sporocarp surveys) and belowground (RFLP identification of ectomycorrhizal root tips); however total diversity was not higher in oak savanna than oak forests and there was no evidence of a greater abundance of ascomycetes. Despite not having a higher local diversity than oak forests, the presence of a unique fungal community indicates that oak savanna plays an important role in maintaining regional ectomycorrhizal diversity.

Assembling the Fungal Tree of Life: constructing the structural and biochemical database.

A major goal of the Assembling the Fungal Tree of Life project is to create a searchable database of selected ultrastructural and biochemical characters from published and new data for use in phylogenetic and other analyses. While developing this database such issues as evaluating specimen fixation quality in published micrographs, organizing data to accommodate characters that were dependent on location and developmental stage, and requiring accountability of data contributors were addressed. Character states for three traits, septal pore apparatus, nuclear division and spindle pole body cycle, are illustrated, and character states are resolved with maximum parsimony and plotted on a summary cladogram of known phylogenetic relationships of the Fungi. The analysis illustrates the inherent phylogenetic signal of these characters, the paucity of comparable characters and character states in subcellular studies and the challenges in establishing a comprehensive structural and biochemical database of the Fungi.

Convergent coevolution in the domestication of coral mushrooms by fungus-growing ants.

Comparisons of phylogenetic patterns between coevolving symbionts can reveal rich details about the evolutionary history of symbioses. The ancient symbiosis between fungus-growing ants, their fungal cultivars, antibiotic-producing bacteria and cultivar-infecting parasites is dominated by a pattern of parallel coevolution, where the symbionts of each functional group are members of monophyletic groups. However, there is one outstanding exception in the fungus-growing ant system, the unidentified cultivar grown only by ants in the Apterostigma pilosum group. We classify this cultivar in the coral-mushroom family Pterulaceae using phylogenetic reconstructions based on broad taxon sampling, including the first mushroom collected from the garden of an ant species in the A. pilosum group. The domestication of the pterulaceous cultivar is independent from the domestication of the gilled mushrooms cultivated by all other fungus-growing ants. Yet it has the same overall assemblage of coevolved ant-cultivar-parasite-bacterium interactions as the other ant-grown fungal cultivars. This indicates a pattern of convergent coevolution in the fungus-growing ant system, where symbionts with both similar and very different evolutionary histories converge to functionally identical interactions.

Dose reduction to radiosensitive tissues in CT. Do commercially available shields meet the users' needs?

AIM: To assess the effectiveness and economy of routinely using commercially available in-plane bismuth shielding during CT scanning of the chest and brain. METHODS AND MATERIALS: Forty patients were scanned with thermoluminescent dosemeters (TLDs) in situ to measure the radiation dose to the thyroid and eye during CT scanning of the brain and chest. Half of the patients had the "AttenuRad" shield in place during scanning. RESULTS: Use of the shielding reduced the mean dose to the eye from 6.0 +/- 0.3 mGy to 4.9 mGy +/- 0.2 mGy and the thyroid dose from 16.4 mGy +/- 1.2 mGy to 7.1 mGy +/- 0.5 mGy. CONCLUSION: Use of the thyroid shield is recommended for all CT scanning of the chest. The eye shield does not produce as marked a reduction in radiation dose to the lens of the eye, when an angled gantry is used, since the eyes are not in the primary beam. Use of the eyeshield is justifiable where irradiation of the orbit is unavoidable, although whether artifacts would be a problem if the shield was used in this way was not assessed.

Do graduated compression stockings and pneumatic boots have an additive effect on the peak velocity of venous blood flow?

Graduated compression stockings and intermittent pneumatic compression boots reduce the incidence of deep vein thrombosis. Recent studies suggest that the simultaneous use of these devices may have a synergistic prophylactic effect; however, conflicting reports also exist. Using duplex imaging, we analyzed the effect on peak venous velocity in the superficial femoral vein produced by the individual and simultaneous use of graduated compression stockings and intermittent pneumatic compression boots. Normal volunteers and postoperative patients were examined. The use of intermittent pneumatic compression boots significantly increased the peak venous velocity relative to rest, whereas the use of graduated compression stockings did not alter the peak venous velocity. Also, the addition of graduated compression stockings to legs already being treated with intermittent pneumatic compression boots did not produce a further augmentation of peak venous velocity. This study demonstrates that the simultaneous use of graduated compression stockings and intermittent pneumatic compression boots does not produce a synergistic augmentation of peak venous velocity in the superficial femoral vein.

A prospective randomized study comparing surgical and percutaneous removal of intraaortic balloon pump.

This prospective randomized study of 50 patients compares the prevalence of complications between surgical and percutaneous methods of removal of intraaortic balloons. All patients who had percutaneous placement of a 9.5F intraaortic balloon during a 6-month period were eligible for the study. Patients were excluded if the intraaortic balloon was placed surgically, if a coagulopathy was present, or if acute leg ischemia developed at any time after insertion. After informed consent, 25 patients were randomized to each method of removal. Two complications occurred in the surgical group, including a wound infection and a lymph fistula. In one patient in the percutaneous group, a false aneurysm of the femoral artery developed. There was no significant difference between the mean of 59 minutes for percutaneous removal and 47 minutes for operative removal of the balloon (p = 0.74). The percutaneous method is therefore more cost-effective, because it does not require the use of operating room personnel or equipment necessary for surgical removal. The results of this study indicate that the majority of percutaneously placed intraaortic balloons may be safely removed percutaneously. Surgical removal of 9.5F intraaortic balloons is recommended for patients with bleeding diatheses, hemorrhagic or ischemic complications, or for those in whom the intraaortic balloon was inserted with a surgical procedure.

The organization of microtubules during anaphase and telophase spindle elongation in the rust fungus Puccinia.

The entire framework of microtubules (MTs) in the meiotic spindle of the rust fungus Puccinia has been reconstructed during the later stages of meiosis I, by tracking MTs through transverse serial sections. This spindle is of special interest because it elongates considerably during anaphase spindle elongation, from 5 microns at metaphase to 15 microns at telophase. The spindle is composed mainly of MTs from opposite poles which interdigitate or overlap in the middle of the spindle. In the overlap region, MTs from one pole seek out as near neighbors, MTs from the opposite pole at a preferred spacing of 43 to 55 nm. During anaphase elongation three changes in spindle structure occur: 1) the region of overlap decreases, but this reduction in overlap cannot account for all the increase in spindle length; 2) interdigitated MTs (MTs from one pole that are within 80 nm of a MT from the opposite pole) dramatically increase in length by MT polymerization and; 3) kinetochore MTs, free MTs (those unattached to the poles) and non-interdigitated polar MTs shorten and disappear. The mechanism of anaphase elongation and the control over MT polymerization and depolymerization during anaphase are discussed.

Golgi apparatus in the postmeiotic basidium of Coprinus lagopus.

A golgi apparatus believed to be involved in basidiospore formation has been found in Coprinus lagopus following meiosis in the basidium.

Centrosomes and microtubules during meiosis in the mushroom Boletus rubinellus.

The double centrosome in the basidium of Boletus rubinellus has been observed in three planes with the electron microscope at interphase preceding nuclear fusion, at prophase I, and at interphase I. It is composed of two components connected by a band-shaped middle part. At anaphase I a single, enlarged centrosome is found at the spindle pole, which is attached to the cell membrane. Microtubules mainly oriented parallel to the longitudinal axis of the basidium are present at prefusion, prophase I and interphase I. Cytoplasmic microtubules are absent when the spindle is present. The relationship of the centrosome in B. rubinellus to that in other organisms and the role of the cytoplasmic microtubules are discussed.