Preliminary results of a vaginal constraint for reducing G2 late vaginal complications after postoperative brachytherapy in endometrial cancer: a prospective analysis.

PURPOSE: To evaluate the preliminary results of the use of 68 Gy EQD2(α/ß=3 Gy) as a dose limit to the lowest dose in the most exposed 2 cm3 of the vagina in order to reduce G2 late vaginal problems in postoperative endometrial carcinoma (EC). METHODS: From November 2016 to October 2019, 69 postoperative EC patients receiving vaginal brachytherapy (VBT) ± external beam radiotherapy (EBRT) were prospectively analyzed. The median EBRT dose was 45 Gy (range: 44-50.4 Gy), 1.8-2 Gy/day, 5 fractions(Fr)/week. VBT was administered with the following schedule: 1Fr of 7 Gy after EBRT and 2 daily Fr × 7.5 Gy in exclusive VBT. The dose was prescribed at 0.5 cm from the applicator surface with an active length of 2.5 cm; 56 patients were treated with vaginal cylinders (49-3.5 cm, 6-3 cm, and 1-2.5 cm) and 13 with the colpostat technique. The overall VBT dose was adjusted to meet the vaginal restriction of < 68 Gy EQD2(α/ß=3 Gy) at 2 cm3. Late toxicity was prospectively assessed using RTOG scores for bladder and rectum, and the objective LENT-SOMA criteria for vagina. RESULTS: With a median follow-up of 31.0 months, no vaginal-cuff recurrences were found. Late toxicity: only 1G1(1.4%) rectal toxicity; 21G1(30.4%) and 3G2(4.3%) vaginal complications. Only one (1.4%) of 3 G2 manifested as vaginal shortening. CONCLUSIONS: In postoperative EC patients treated with VBT, only one developed G2 vaginal stenosis with the use of 68 Gy EQD2(α/ß=3 Gy) as a dose constraint. These preliminary results seem to indicate the value of this dose limit for reducing G2 vaginal stenosis. Nonetheless, these findings should be confirmed in a larger number of patients with longer follow-up.

Is one brachytherapy fraction of 7 Gy similar to more fractions after external beam irradiation in postoperative endometrial carcinoma?

PURPOSE: To determine whether brachytherapy with a single hypofractionated dose of 7 Gy provides the similar vaginal-cuff relapses and safety profile in terms of complications compared to schedules of 2 or 3 fractions of lower doses in patients treated previously with external beam irradiation in postoperative endometrial carcinoma. METHODS/MATERIAL: From June 2003 to December 2016, 325 patients were treated with 3 different schedules of high-dose-rate brachytherapy after external beam irradiation for postoperative endometrial carcinoma. The patients were divided into 3 groups: Group-1: 125 patients were treated with 3 fractions of 4-6 Gy per fraction (3 fractions/week) between 2003 and 2008; Group-2: 93 patients were treated with 2 consecutive daily fractions of 5-6 Gy between 2008 and 2011; Group-3: 107 patients received a single fraction of 7 Gy between 2011 and 2016. Bladder and rectum complications were assessed using RTOG scores and with the objective scores of LENT-SOMA for the vagina. STATISTICS: the chi-square test. RESULTS: The mean follow-up of Groups 1, 2 and 3 was 95, 67 and 51 months, respectively. Three patients in Group-1, 2 in Group-2, 1 in Group-3 developed vaginal-cuff relapse (p = 0.68). No differences were found in late toxicity among the three groups. CONCLUSIONS: One single dose of 7 Gy is safe and effective and may be the best treatment schedule with a similar incidence of vaginal-cuff relapses, complications and patient comfort with less hospital attendance.

Author Correction: Unprecedented rains decimate surface microbial communities in the hyperarid core of the Atacama Desert.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Unprecedented rains decimate surface microbial communities in the hyperarid core of the Atacama Desert.

The hyperarid core of the Atacama Desert, the driest and oldest desert on Earth, has experienced a number of highly unusual rain events over the past three years, resulting in the formation of previously unrecorded hypersaline lagoons, which have lasted several months. We have systematically analyzed the evolution of the lagoons to provide quantitative field constraints of large-scale impacts of the rains on the local microbial communities. Here we show that the sudden and massive input of water in regions that have remained hyperarid for millions of years is harmful for most of the surface soil microbial species, which are exquisitely adapted to survive with meager amounts of liquid water, and quickly perish from osmotic shock when water becomes suddenly abundant. We found that only a handful of bacteria, remarkably a newly identified species of Halomonas, remain metabolically active and are still able to reproduce in the lagoons, while no archaea or eukaryotes were identified. Our results show that the already low microbial biodiversity of extreme arid regions greatly diminishes when water is supplied quickly and in great volumes. We conclude placing our findings in the context of the astrobiological exploration of Mars, a hyperarid planet that experienced catastrophic floodings in ancient times.

Are endometrial cancer radiotherapy results age related?

OBJECTIVE: To analyze the impact of age on radiotherapy results based on cancer-specific survival (CSS), vaginal-cuff relapses (VCR) and complications analysis in 438 patients with endometrial carcinoma (EC) receiving postoperative radiotherapy (PRT) divided into three age groups for analysis. MATERIALS AND METHODS: From 2003 to 2015, 438 patients with EC were treated with PRT and divided into three age groups: Group-1: 202 patients < 65 years; Group-2: 210 patients ≥ 65 and < 80 years; Group-3: 26 patients ≥ 80 years. Vaginal toxicity was assessed using the objective LENT-SOMA criteria and RTOG scores were recorded for the rectum, bladder, and small bowel. STATISTICS: Chi square and Student's t tests, Kaplan-Meier survival study for analysis of CSS. RESULTS: The mean follow-up was 5.6 years in Group-1, 5.6 years in Group-2 and 6.3 years in Group-3 (p = 0.38). No differences were found among the groups in distribution of stage, grade, myometrial invasion, Type 1 vs. 2 EC and VLSI (p = 0.97, p = 0.52, p = 0.35, p = 0.48, p = 0.76, respectively). There were no differences in rectal, bladder and vagina late toxicity (p = 0.46, p = 0.17, p = 0.75, respectively). A better CSS at 5 years was found in Group-1 (p = 0.006), and significant differences were found in late severe small bowel toxicity in Group-3 (p = 0.005). VCR was increased in Group-3 (p = 0.017). CONCLUSIONS: Patients ≥ 65 years had a worse outcome in comparison to younger patients. Late vaginal, rectal and bladder toxicities were similar in the three groups, although an increase of severe late small bowel toxicity led to IMRT in patients ≥ 80 years. Further larger studies are needed including quality of life analysis in patients ≥ 80 years.

Vaginal-cuff control and toxicity results of a daily HDR brachytherapy schedule in endometrial cancer patients.

PURPOSE: To analyze the vaginal-cuff local control (VCC) and toxicity in postoperative endometrial carcinoma patients (EC) underwent high-dose-rate brachytherapy (HDR-BT) administered daily. MATERIALS AND METHODS: 154 consecutive patients received postoperative HDR-BT for EC from January 2007 to September 2011. FIGO-staging I-IIIC2 patients were divided into two groups according to risk classification: Group 1 (94/154) included high-risk or advanced disease patients and Group 2 (60/154) included intermediate-risk EC patients. Group 1 underwent external beam irradiation (EBI) plus HDR-BT (2 fractions of 5 Gy) and Group 2 underwent HDR-BT alone (4 fractions of 5 Gy). Toxicity evaluation was done with RTOG scores for bladder and rectum, and the objective criteria of LENT-SOMA for vagina. RESULTS: With a median follow-up of 46.7 months (36.6-61 months) only two patients developed vaginal-cuff recurrence in Group 1 (2.1 %) and none in group 2 (0 %). Early toxicity in Group 1 appeared 5.3 % in rectum, 7.5 % in bladder (G1-G2) and 2.1 % in vagina (G1); late toxicity was present in 7.3 % in rectum (all G1-G2 but 1 G3) and in 27.7 % in vagina (all G1-G2 but one G4). In Group 2, 6.7 % developed acute G1-G2 bladder and 6.6 % acute vaginal (G1-G2) toxicity. No late rectal or bladder toxicity was observed; 21.7 % of G1-G2 presented late problems in vagina. CONCLUSIONS: The present HDR-BT schedule of 2 fractions of 5 Gy after EBI and 4 fractions of 5 Gy administered daily showed excellent results in terms of VCC and toxicity.

Miniaturized Raman instrumentation detects carotenoids in Mars-analogue rocks from the Mojave and Atacama deserts.

This study is primarily focused on proving the potential of miniaturized Raman systems to detect any biomolecular and mineral signal in natural geobiological samples that are relevant for future application of the technique within astrobiologically aimed missions on Mars. A series of evaporites of varying composition and origin from two extremely dry deserts were studied, namely Atacama and Mojave. The samples represent both dry evaporitic deposits and recent evaporitic efflorescences from hypersaline brines. The samples comprise halite and different types of sulfates and carbonates. The samples were analysed in two different ways: (i) directly as untreated rocks and (ii) as homogenized powders. Two excitation wavelengths of miniaturized Raman spectrometers were compared: 532 and 785 nm. The potential to detect carotenoids as biomarkers on Mars compared with the potential detection of carbonaceous matter using miniaturized instrumentation is discussed.

Fluorescent fingerprints of endolithic phototrophic cyanobacteria living within halite rocks in the Atacama Desert.

Halite deposits from the hyperarid zone of the Atacama Desert reveal the presence of endolithic microbial colonization dominated by cyanobacteria associated with heterotrophic bacteria and archaea. Using the λ-scan confocal laser scanning microscopy (CLSM) option, this study examines the autofluorescence emission spectra produced by single cyanobacterial cells found inside halite rocks and by their photosynthetic pigments. Photosynthetic pigments could be identified according to the shapes of the emission spectra and wavelengths of fluorescence peaks. According to their fluorescence fingerprints, three groups of cyanobacterial cells were identified within this natural extreme microhabitat: (i) cells producing a single fluorescence peak corresponding to the emission range of phycobiliproteins and chlorophyll a, (ii) cells producing two fluorescence peaks within the red and green signal ranges, and (iii) cells emitting only low-intensity fluorescence within the nonspecific green fluorescence signal range. Photosynthetic pigment fingerprints emerged as indicators of the preservation state or viability of the cells. These observations were supported by a cell plasma membrane integrity test based on Sytox Green DNA staining and by transmission electron microscopy ultrastructural observations of cyanobacterial cells.

Three or four fractions per week in postoperative high-dose-rate brachytherapy for endometrial carcinoma. The long-term results on vaginal relapses and toxicity.

BACKGROUND: High-dose-rate brachytherapy (HDR-BT) is an accepted part of treatment for endometrial carcinoma and is usually performed in 1-2 fractions per week using different total doses and doses per fraction. To reduce the overall treatment time, HDR-BT was administered with a 3-4 days/week schedule. PATIENTS AND METHODS: From June 2003 to December 2008, 164 patients with stage I-IIIc endometrial carcinoma were treated with HDR-BT (4-5 Gy per fraction). The patients were divided into two groups; Group 1 (40/164 patients) was treated with HDR-BT alone (6 fractions; 4 fractions/week) and Group 2 (124/164 patients) was treated with both (External Beam Radiotherapy [EBRT] + HDR-BT: 3 fractions/week). Complications were analyzed using RTOG scores for rectum and bladder and the objective scores of LENT-SOMA for vaginal complications. RESULTS: The mean followup was 48 months. In Group 1, 35 % of patients underwent treatment in ≤10 days and 65 % in >10 days. In Group 2, 53.2 % received treatment in ≤5 days and in 46.8 % in >5 days. Vaginal relapse was observed in only two patients (1.2 %), both having received adjuvant EBRT + HDR-BT. Acute vaginal toxicity appeared in 8.5 % and late vaginal toxicity in 20.7 % of patients with 13.4 % being G1, 6.7 % G2 and only 0.6 % being G4. No statistically significant differences were found in complications in either brachytherapy group regardless of the overall time. CONCLUSION: In our series, three fractions given in 3-5/days after EBRT or six fractions in 10 days, is a safe regimen in terms of complications and local control.

Towards a more realistic picture of in situ biocide actions: combining physiological and microscopy techniques.

In this study, we combined chlorophyll a fluorescence (ChlaF) measurements, using pulse-amplitude-modulate (PAM) equipment, with scanning electron microscopy in backscattered electron mode (SEM-BSE) and transmission electron microscopy (TEM) images to evaluate the actions of Koretrel at lower concentrations on Verrucaria nigrescens colonising a dolostone. ChlaF measurements are good indicators of the damaging effects of biocides. However, these indicators only provide an incomplete view of the mechanism of biocides used to control biodeterioration agents. The death of the V. nigrescens photobiont at two biocide concentrations was revealed by PAM, SEM-BSE and TEM. Once Koretrel was applied, the Fv/Fm ratios markedly fell in the first few hours after the 1.5% treatment, and ratios for the 3% dilution remained close to zero throughout the study. The algal zone shows the plasmolysed appearance of the photobiont cells, and important aspects related to the action of the biocide on free and lichenised fungi were also detected using SEM-BSE. Many of the mycobiont cells had only their cell walls preserved; although, some fungal hyphae in lichen thalli and some microorganisms in endolithic clusters maintained lipid storage in their cytoplasm. These results indicated that the combination of physiological and microscopy techniques improves the assessment of biocide action in situ and this will help to optimize protocols in order to reduce the emission of these compounds to the environment.

Whole lichen thalli survive exposure to space conditions: results of Lithopanspermia experiment with Aspicilia fruticulosa.

The Lithopanspermia space experiment was launched in 2007 with the European Biopan facility for a 10-day spaceflight on board a Russian Foton retrievable satellite. Lithopanspermia included for the first time the vagrant lichen species Aspicilia fruticulosa from Guadalajara steppic highlands (Central Spain), as well as other lichen species. During spaceflight, the samples were exposed to selected space conditions, that is, the space vacuum, cosmic radiation, and different spectral ranges of solar radiation (λ ≥ 110, ≥200, ≥290, or ≥400 nm, respectively). After retrieval, the algal and fungal metabolic integrity of the samples were evaluated in terms of chlorophyll a fluorescence, ultrastructure, and CO(2) exchange rates. Whereas the space vacuum and cosmic radiation did not impair the metabolic activity of the lichens, solar electromagnetic radiation, especially in the wavelength range between 100 and 200 nm, caused reduced chlorophyll a yield fluorescence; however, there was a complete recovery after 72 h of reactivation. All samples showed positive rates of net photosynthesis and dark respiration in the gas exchange experiment. Although the ultrastructure of all flight samples showed some probable stress-induced changes (such as the presence of electron-dense bodies in cytoplasmic vacuoles and between the chloroplast thylakoids in photobiont cells as well as in cytoplasmic vacuoles of the mycobiont cells), we concluded that A. fruticulosa was capable of repairing all space-induced damage. Due to size limitations within the Lithopanspermia hardware, the possibility for replication on the sun-exposed samples was limited, and these first results on the resistance of the lichen symbiosis A. fruticulosa to space conditions and, in particular, on the spectral effectiveness of solar extraterrestrial radiation must be considered preliminary. Further testing in space and under space-simulated conditions will be required. Results of this study indicate that the quest to discern the limits of lichen symbiosis resistance to extreme environmental conditions remains open.

Microbial colonization of Ca-sulfate crusts in the hyperarid core of the Atacama Desert: implications for the search for life on Mars.

The scarcity of liquid water in the hyperarid core of the Atacama Desert makes this region one of the most challenging environments for life on Earth. The low numbers of microbial cells in the soils suggest that within the Atacama Desert lies the dry limit for life on our planet. Here, we show that the Ca-sulfate crusts of this hyperarid core are the habitats of lithobiontic micro-organisms. This microporous, translucent substrate is colonized by epilithic lichens, as well as endolithic free-living algae, fungal hyphae, cyanobacteria and non photosynthetic bacteria. We also report a novel type of endolithic community, "hypoendoliths", colonizing the undermost layer of the crusts. The colonization of gypsum crusts within the hyperarid core appears to be controlled by the moisture regime. Our data shows that the threshold for colonization is crossed within the dry core, with abundant colonization in gypsum crusts at one study site, while crusts at a drier site are virtually devoid of life. We show that the cumulative time in 1 year of relative humidity (RH) above 60% is the best parameter to explain the difference in colonization between both sites. This is supported by controlled humidity experiments, where we show that colonies of endolithic cyanobacteria in the Ca-sulfate crust undergo imbibition process at RH >60%. Assuming that life once arose on Mars, it is conceivable that Martian micro-organisms sought refuge in similar isolated evaporite microenvironments during their last struggle for life as their planet turned arid.

Microbial colonization of halite from the hyper-arid Atacama Desert studied by Raman spectroscopy.

The hyper-arid core of the Atacama Desert (Chile) is the driest place on Earth and is considered a close analogue to the extremely arid conditions on the surface of Mars. Microbial life is very rare in soils of this hyper-arid region, and autotrophic micro-organisms are virtually absent. Instead, photosynthetic micro-organisms have successfully colonized the interior of halite crusts, which are widespread in the Atacama Desert. These endoevaporitic colonies are an example of life that has adapted to the extreme dryness by colonizing the interior of rocks that provide enhanced moisture conditions. As such, these colonies represent a novel example of potential life on Mars. Here, we present non-destructive Raman spectroscopical identification of these colonies and their organic remnants. Spectral signatures revealed the presence of UV-protective biomolecules as well as light-harvesting pigments pointing to photosynthetic activity. Compounds of biogenic origin identified within these rocks differed depending on the origins of specimens from particular areas in the desert, with differing environmental conditions. Our results also demonstrate the capability of Raman spectroscopy to identify biomarkers within rocks that have a strong astrobiological potential.

Laboratory-induced endolithic growth in calcarenites: biodeteriorating potential assessment.

This study is aimed to assess the formation of photosynthetic biofilms on and within different natural stone materials, and to analyse their biogeophysical and biogeochemical deterioration potential. This was performed by means of artificial colonisation under laboratory conditions during 3 months. Monitoring of microbial development was performed by image analysis and biofilm biomass estimation by chlorophyll extraction technique. Microscopy investigations were carried out to study relationships between microorganisms and the mineral substrata. The model applied in this work corroborated a successful survival strategy inside endolithic microhabitat, using natural phototrophic biofilm cultivation, composed by cyanobacteria and algae, which increased intrinsic porosity by active mineral dissolution. We observed the presence of mineral-like iron derivatives (e.g. maghemite) around the cells and intracellularly and the precipitation of hausmannite, suggesting manganese transformations related to the biomineralisation.

Renal expression of adhesion molecules in anca-associated disease.

INTRODUCTION: Anti-neutrophil cytoplasmic autoantibodies (ANCA)-associated disease among other manifestations can underlie rapidly progressive glomerulonephritis (RPGN), with crescentic and necrotizing GN. Differences in pathogenic immune mechanisms in RPGN may provide differences in the renal expression of adhesion molecules mediating these lesions. METHODS: Renal intercellular adhesion molecule 1 (ICAM-1; CD54) and vascular cell adhesion molecule 1 (VCAM-1; CD106) were assessed in 40 patients with type I RPGN (anti-glomerular basement membrane antibodies, n = 4), type II (immune complexes, n = 17), and type III (ANCA, n = 19). Enzyme-linked immunosorbent assay (ELISA) for detection of immunoglobulin G antibodies against the Goodpasture's antigen and indirect immunofluorescence and ELISA for myeloperoxidase (MPO) and proteinase 3 (PR3) were performed for ANCA testing. Ten normal renal tissues were used as controls. Relationships between ICAM-1 and VCAM-1, histopathologic features, and CD18, CD14, and CD3 cells were analyzed. RESULTS: Abnormal ICAM-1 and VCAM-1 in tubule was seen in >80% of biopsies with RPGN. Abnormal VCAM-1 in glomerular tuft was seen in >60% of biopsies with RPGN. Glomerular ICAM-1 was associated with less glomerulosclerosis (chi (2) = 6.719, p = 0.01), less interstitial fibrosis (chi (2) = 4.322, p < 0.05), and less tubular atrophy (chi (2) = 8.547, p < 0.005). Glomerular VCAM-1 was associated with glomerular leukocyte infiltration (chi (2) = 4.698, p < 0.05). Glomerular tuft stains of ++/+++ for VCAM-1 was observed in 10% from MPO-ANCA-GN patients but in 60% from PR3-ANCA-GN (Fi = 8.538, p = 0.03). CONCLUSIONS: The following conclusions can be made from this study. (1) The renal expression of ICAM-1 and VCAM-1 is upregulated in RPGN, and this is associated with the histological activity. (2) De novo expression of VCAM-1 on glomerular tuft suggests that endothelial cells play a role in RPGN. (3) De novo tubular expression of ICAM-1 and VCAM-1 suggests that epithelial cells may participate in adhesive interactions in RPGN. (4) De novo expression of VCAM-1 at the glomerular tuft in PR3-ANCA positive patients seems greater than in MPO-ANCA positive patients, which suggests that testing specific immune activation mechanisms may play a role in ANCA-associated GN.

Advances in the ultrastructural study of the implant-bone interface by backscattered electron imaging.

The biocompatibility of titanium implants in bone depends on the response shown by cells in contact with the implant surface. Several developments have been targeted at achieving successful implant treatment. The aim of this study was to develop a novel preparation procedure to evaluate the bone cell response produced at the bone-implant interface using the technique scanning electron microscopy with backscattered electron imaging (SEM-BSE). Dental prostheses with an SLA-modified or TOP-modified surface were implanted in a toothless part of the mandibula in female pigs. The animals were sacrificed 12 weeks after surgery, at which time block specimens containing the implants were obtained. These specimens were then processed for SEM-BSE by optimizing a protocol involving chemical fixation and heavy metal staining. In addition, element distribution maps for the implant-bone tissue interface were obtained using a microanalytical system based on energy-dispersive X-ray spectrometry (EDS). This novel visualisation approach enabled a comprehensive study of the extracellular matrix and cell components of the host tissues neoformed around the implant. SEM-BSE images also provided ultrastructural details of the bone cells. This technique appears to be an effective and very promising tool for detailed studies on the implant-bone tissue interface and the host response to the bone incorporation process.

Reduction in the prevalence and intensity of infection in Onchocerca volvulus microfilariae according to ethnicity and community after 8 years of ivermectin treatment on the island of Bioko, Equatorial Guinea.

Bioko is the only island known in the world with endemic onchocerciasis. The island's rural communities consist of villages and cocoa plantations inhabited by Bubi and Fang ethnic groups. The aim of this study was to evaluate the impact of 8 years of vertical ivermectin distribution on the prevalence and intensity of Onchocerca volvulus infection in the rural population by means of pre- (1989) and post-long term treatment (1998) epidemiological surveys. In both surveys, the entire population of 12 randomly selected communities (1723 and 1082 individuals) was examined. The mean ivermectin therapeutic coverage for the 8 years was 53.2%. Iliac crest skin snips were used for differential diagnosis between O. volvulus and Mansonella streptocerca. The crude O. volvulus infection prevalence before ivermectin intervention was 74.5% (1284/1723); after the intervention it was 38.4% (415/1082). The Community Microfilarial Load (CMFL) before and after ivermectin intervention was 28.29 microfilariae/snip vs. 2.32 microfilariae/snip. The reduction in prevalence and CMFL after eight annual rounds of ivermectin treatment corroborates the drug microfilaricidal activity and good tolerability. In the pre-treatment survey, the prevalence was higher in the Bubi group (77.1%, 1126/1461); post-treatment it was higher among the Fang (51.1%, 92/180). The reduction in prevalence and intensity of O. volvulus infection differed between ethnic groups and communities.

Renal expression of ICAM-1 and VCAM-1 in ANCA-associated glomerulonephritis--are there differences among serologic subgroups?

BACKGROUND: Antineutrophil cytoplasmic autoantibodies (ANCA) play a role in the expression of adhesion molecules. Differences in ANCA test results in ANCA-associated vasculitis may provide differences in their renal expression. PATIENTS AND METHODS: We assessed the renal expression of ICAM-1 and VCAM-1 with monoclonal antibodies in 19 patients with ANCA-vasculitis: 7 microscopic polyangiitis, 5 Wegener's granulomatosis, 4 renal-limited vasculitis and 3 Churg-Strauss disease. Immunofluorescence and ELISA for myeloperoxidase (MPO) and proteinase 3 (PR3) were performed for ANCA-testing. 10 normal renal tissues were used as controls. RESULTS: The ANCA staining pattern was perinuclear in 14 patients, with MPO-ANCA 31 - 220 EU/ml, and cytoplasmic in 5, with PR3-ANCA 37 - 144 EU/ml. Abnormal tubular expression of ICAM-1 and VCAM-1 was seen in more than 80% of biopsies and abnormal expression of VCAM-1 in glomerular tuft was seen in 60%. Glomerular tuft stains of ++ or +++ for VCAM-1 were observed in 10% of renal biopsies from MPO-ANCA-GN patients, but in 60% of biopsies from PR3-ANCA-GN patients (Fi = 8.538, p = 0.03). IN CONCLUSION: De novo expression of VCAM-1 on glomerular tuft suggests that the endothelial cells play a role in ANCA-GN. De novo glomerular expression of VCAM-1 is associated more with ANCA directed against PR3 than with ANCA directed against MPO. Upregulated glomerular expression of VCAM-1 may reflect a higher histological activity in patients with PR3-ANCA, and supports the existence of specific immune activation mechanisms in the different serologic subgroups in ANCA-GN. The de novo tubular expression of ICAM-1 and VCAM-1 suggests that the epithelial cells may participate in adhesive interactions in ANCA-GN.

Endolithic growth of two Lecidea lichens in granite from continental Antarctica detected by molecular and microscopy techniques.

Through the combined use of molecular and microscopy techniques, the endolithic lichens Lecidea cancriformis and Lecidea sp. were identified, even in the absence of fruiting bodies, and positioned under epilithic lichens. Cells of both algal and fungal symbionts were observed in fissures and cracks of the lithic substrate with no clear heteromerous structure. At the ultrastructural level, the two lichens differed in terms of their algal-fungal relationships. Only one genotype of Trebouxia ITS sequence was identified from specimens of Lecidea sp., Umbilicaria aprina and Buellia frigida from the same zone, which could be mainly determined by low availability of alga in these extreme environments. These lichens showed features typical of both chasmoendolithic and euendolithic microorganisms. Signs of biogeophysical and biogeochemical action on the substrate were detected close to fungal cells. This action seemed to be mainly conditioned by the local physico-chemical features of the substrate. Evidence for the biomobilization of elements by these endolithic lichens was found. L. cancriformis was observed to accumulate substantial amounts of calcium-rich biominerals. The combined approach proposed is useful for mapping the distribution of endolithic lichens and analysing the processes that occur in their microscopic environment.

Viability of endolithic micro-organisms in rocks from the McMurdo Dry Valleys of Antarctica established by confocal and fluorescence microscopy.

The rocks of the McMurdo Dry Valleys desert in Antarctica harbour endolithic communities of micro-organisms such as lichens, fungi, cyanobacteria and bacteria. Establishing the physiological status and viability of these microbial colonies in their natural microhabitat has far-reaching implications for understanding the microbial ecology of the harsh environment of this polar desert. Here we describe the use of confocal microscopy and a specific fluorescent probe (FUN-1) to evaluate the metabolic activity of fungal cells. Application of confocal microscopy also served to identify living and dead bacteria or cyanobacteria using the fluorescent assay reagents Live/Dead SYTO 9 and propidium iodide or SYTOX Green, respectively. In addition, through the use of epifluorescence microscopy, live/dead bacteria and cyanobacteria could be detected by estimating fluorescence from their cell components provoked by simultaneously staining with nucleic acids stains such as DAPI and SYTOX Green.