Colony Volume Research Articles

Synergistic effects of zinc and cadmium on phytoremediation potential of Christmas moss (Vesicularia montagnei)

The hyperaccumulation potential of zinc (Zn) and cadmium (Cd) and their synergistic effects were examined in relation to Christmas moss (Vesicularia montagnei (Bél) Broth., Hypnaceae), an aquatic and terrestrial moss, dosed with Cd (Cd1 and Cd2), Zn (Zn1 and Zn2) and combined Zn and Cd (Cd1Zn1 and Cd2Zn2). Zinc promoted plant growth and development, particularly in the highest Zn and combined Zn/Cd treatments (Zn2 and Cd2Zn2). The Zn treatment resulted in substantial moss chlorophyll content and highest percentage relative growth rate in biomass value (0.23 mg L−1 and 106.8%, respectively); however, the Cd2Zn2 treatment achieved maximal production of chlorophyll a and total chlorophyll (0.29 and 0.51 mg L−1, respectively) due to synergistic effects. These findings suggest that Christmas moss is a highly metal-tolerant and adaptable bryophyte species. Zinc was essential for reducing the detrimental effects of Cd while simultaneously promoting moss growth and biomass development. Furthermore, Christmas moss exhibited hyperaccumulation potential for Cd and Zn in the Cd2Zn2 and Zn alone treatments, as evidenced by highest Cd and Zn values in gametophores (1002 and 18,596 mg per colony volume, respectively). Using energy dispersive X-ray fluorescence (EDXRF) spectrometry, atomic percentages of element concentrations in moss gametophores in the Zn2, Cd2 and combined Zn/Cd treatments were generally in the order: K > Ca > P > Zn > Cd. When comparing the atomic percentages of Zn and Cd in gametophores, it is likely that the higher atomic percentage of Zn was because this element is essential for plant growth and development.

Effect of light-mediated variations of colony morphology on the buoyancy regulation of Microcystis colonies

Light is an important driver of algal growth and for the formation of surface blooms. Long-term buoyancy maintenance of Microcystis colonies is crucial for their aggregation at the water surface and the following algal bloom development. However, the effect of light-mediated variations of colony morphology on the buoyancy regulation of Microcystis colonies remains unclear. In this study, growth parameters, colony morphology and floatation/sinking performance of Microcystis colonies were determined to explore how variations in colony morphology influence the buoyancy of colonies under different light conditions. We quantified colony compactness through the cell volume to colony volume ratio (VR) and found different responses of colony size and VR under different light intensities. Microcystis colonies with higher VR could stay longer at the water surface under low light conditions, which was beneficial for the long-term growth and buoyancy maintenance. However, increased colony size and decreased compactness were observed at a later growth stage under relatively higher light intensity (i.e., >108 µmol photons m−2 s−1). Interestingly, we found a counterintuitive negative correlation between colony size and buoyancy of Microcystis under high light intensity. Additionally, we found that the influence of colony morphology on buoyancy was stronger at high light intensity. These results indicate that light could regulate the buoyancy via colonial morphology and that the role of colony morphology in buoyancy regulation needs to be accounted for in further studies under variable environmental conditions.

Study of Ecological Characteristics of Lasius niger (Hymenoptera, Formicidae) Using Vegetation Data

When assessing the condition of Lasius niger (Linnaeus, 1858) nest complexes, plant communities should be considered. The aim of this work is to analyse ecological characteristics and structure of L. niger nest complexes using vegetation data. The study was conducted in Ukraine, in June 2017 (a nest complex on a territory near Vyshneve, Kyiv Oblast, 502 nest mounds) and in June 2022 (Chaika, Kyiv Oblast, 72 nest mounds, Stara Ushytsia, Khmelnytskyi Oblast, 134 nest mounds). Morphometric parametres of the mounds (diameter, height), their relative position and size classes in squares of 100 m2 were studied. At the same time, vegetation plots were carried out. Differences in the structure of L. niger nest mounds discussed previously are at least partly result from differences in the ecological conditions of the localities. Of the six ecological indicators (Hd — Tm), three — soil acidity and nitrogen, and the hemeroby indicator, which assesses the degree of anthropogenic pollution — have a significant influence on the abundance of L. niger nest mounds. These factors were shown to have a significant influence on the ant colony volume indicator. For most indicators, except moisture and light, the optimum for L. niger was close to 50 points (middle of the scale). For the anthropogenic factor, the range of values was the widest, which indirectly confirms the relative tolerance of this species to the anthropogenic influence of moderate intensity and allows its existence in urban conditions where competitive pressure from other species is lower. The sign of regression coefficient, especially the positive sign for the acidity and nitrogen indicators, demonstrates positive effect of these factors on the ant colony structure indicators.

Structure-from-motion photogrammetry demonstrates variability in coral growth within colonies and across habitats.

Coral growth is an important metric of coral health and underpins reef-scale functional attributes such as structural complexity and calcium carbonate production. There persists, however, a paucity of growth data for most reef-building regions, especially for coral species whose skeletal architecture prevents the use of traditional methods such as coring and Alizarin staining. We used structure-from-motion photogrammetry to quantify a range of colony-scale growth metrics for six coral species in the Mexican Caribbean and present a newly developed workflow to measure colony volume change over time. Our results provide the first growth metrics for two species that are now major space occupiers on Caribbean reefs, Agaricia agaricites and Agaricia tenuifolia. We also document higher linear extension, volume increase and calcification rates within back reef compared to fore reef environments for four other common species: Orbicella faveolata, Porites astreoides, Siderastrea siderea and Pseudodiploria strigosa. Linear extension rates in our study were lower than those obtained via computed tomography (CT) scans of coral cores from the same sites, as the photogrammetry method averages growth in all dimensions, while the CT method depicts growth only along the main growth axis (upwards). The comparison of direct volume change versus potential volume increase calculated from linear extension emphasizes the importance of assessing whole colony growth to improve calcification estimates. The method presented here provides an approach that can generate accurate calcification estimates alongside a range of other whole-colony growth metrics in a non-invasive way.

Uncertainties of cell number estimation in cyanobacterial colonies and the potential use of sphere packing

Cyanobacteria are notorious bloom formers causing various water quality concerns, such as toxin production, extreme diurnal variation of oxygen, pH, etc., therefore, their monitoring is essential to protect the ecological status of aquatic systems. Cyanobacterial cell counts and biovolumes are currently being used in water management and water quality alert systems. In this study, we investigated the accuracy of traditional colonial biovolume and cell count estimation approaches used in everyday practice. Using shape realistic 3D images of cyanobacterial colonies, we demonstrated that their shape cannot be approximated by ellipsoids. We also showed that despite the significant relationship between overall colony volume and cell biovolumes, because of the considerable scatter of cell count data the regressions give biased estimates for cyanobacterial cell counts. We proposed a novel approach to estimate cell counts in colonies that was based on the random close sphere packing method. This method provided good results only in those cases when overall colony volumes could be accurately measured. The visual investigation of colonies done by skilled experts has given precise but lower estimates for cell counts. The estimation results of several experts were surprisingly good, which suggests that this capability can be improved and estimation bias can be reduced to the level acceptable for water quality estimations.

Recovery of Microcystis surface scum following a mixing event: Insights from a tank experiment

Cyanobacteria of the genus Microcystis produces surface scum that negatively affects water quality in inland waters. This scum layer can be disintegrated and vertically dispersed by external forces (e.g., wind mixing), followed by reformation of surface scum as buoyant Microcystis colonies migrate upward. However, the recovery dynamics of Microcystis surface scum following a strong mixing event have rarely been studied. Here, we used a tank experiment to investigate the process of Microcystis surface scum recovery after a mixing event with focus on dynamics of colonies of different size classes and their contribution to that process. Microcystis colony size distribution and colony volume concentration was measured using a laser in-situ scattering and transmissometry instrument. The dynamics of Microcystis in the water column and upward colony migration velocity were strongly dependent on colony size. Larger colonies (>180 μm) with fast upward migration rates contributed the most to surface scum formation shortly after turbulence subsided. The contribution of slowly migrating smaller colonies to scum formation was observed over notably longer time. The estimated floating velocities of large colonies ranged 0.15 to 0.46 m h−1 depending on colony size and were 5–15 times higher than those of smaller colonies (~0.03 m h−1). The changes in colony size distribution of Microcystis in the water column reflect the dynamics of surface scum. Analysis of size distribution of Microcystis colonies can be used for better understanding and prediction of Microcystis surface scum development in water bodies.

In Situ Collection and Preservation of Intact Microcystis Colonies to Assess Population Diversity and Microcystin Quotas.

Understanding of colony specific properties of cyanobacteria in the natural environment has been challenging because sampling methods disaggregate colonies and there are often delays before they can be isolated and preserved. Microcystis is a ubiquitous cyanobacteria that forms large colonies in situ and often produces microcystins, a potent hepatotoxin. In the present study a new cryo-sampling technique was used to collect intact Microcystis colonies in situ by embedding them in a sheet of ice. Thirty-two of these Microcystis colonies were investigated with image analysis, liquid chromatography-mass spectrometry, quantitative polymerase chain reaction and high-throughput sequencing to assess their volume, microcystin quota and internal transcribed spacer (ITS) genotype diversity. Microcystin quotas were positively correlated to colony volume (R2 = 0.32; p = 0.004). Individual colonies had low Microcystis ITS genotype diversity and one ITS operational taxonomic unit predominated in all samples. This study demonstrates the utility of the cryo-sampling method to enhance the understanding of colony-specific properties of cyanobacteria with higher precision than previously possible.

Non-Invasive Quantification of the Growth of Cancer Cell Colonies by a Portable Optical Coherence Tomography.

Investigation of tumor development is essential in cancer research. In the laboratory, living cell culture is a standard bio-technology for studying cellular response under tested conditions to predict in vivo cellular response. In particular, the colony formation assay has become a standard experiment for characterizing the tumor development in vitro. However, quantification of the growth of cell colonies under a microscope is difficult because they are suspended in a three-dimensional environment. Thus, optical coherence tomography (OCT) imaging was develop in this study to monitor the growth of cell colonies. Cancer cell line of Huh 7 was used and the cells were applied on a layer of agarose hydrogel, i.e., a non-adherent surface. Then, cell colonies were gradually formed on the surface. The OCT technique was used to scan the cell colonies every day to obtain quantitative data for describing their growth. The results revealed the average volume increased with time due to the formation of cell colonies day-by-day. Additionally, the distribution of cell colony volume was analyzed to show the detailed information of the growth of the cell colonies. In summary, the OCT provides a non-invasive quantification technique for monitoring the growth of the cell colonies. From the OCT images, objective and precise information is obtained for higher prediction of the in vivo tumor development.

Open-Source High-Throughput Phenomics of Bacterial Promoter-Reporter Strains.

Open-source electronics are becoming more prevalent in biological sciences, enabling novel and unique means of data acquisition. Here, we present 3D-printed, open-source tools to acquire fluorescence phenotypes with high temporal resolution. Printed fluorescence imaging boxes (PFIboxes) cost approximately 200US dollars to assemble, can be placed in incubators or hypoxic chambers, and accurately read high-density colony arrays of microorganisms. We demonstrate the utility of PFIboxes using a timecourse gene expression approach, examining globalEscherichia coli promoter activity using a fluorescent reporter library across a diverse panel of 15 antibiotics, each at several concentrations. Many secondary and indirect effects were observed when E.coli was challenged with various drugs, including increased gene expression in carbon metabolism processes. Further, kinetic data acquisition enabled non-destructive time course gene expression, clustering of which revealed patterns of co-expression. In all, PFIboxes provide an open solution to gene expression, for about 2US dollars per treatment condition, including technical replicates.

Volumetric Analysis of 3-D-Cultured Colonies in Wet Alginate Spots Using 384-Pillar Plate.

The volumetric analysis of three-dimensional (3-D)-cultured colonies in alginate spots has been proposed to increase drug efficacy. In a previously developed pillar/well chip platform, colonies within spots are usually stained and dried for analysis of cell viability using two-dimensional (2-D) fluorescent images. Since the number of viable cells in colonies is directly related to colony volume, we proposed the 3-D analysis of colonies for high-accuracy cell viability calculation. The spots were immersed in buffer, and the 3-D volume of each colony was calculated from the 2-D stacking fluorescent images of the spot with different focal positions. In the experiments with human gastric carcinoma cells and anticancer drugs, we compared cell viability values calculated using the 2-D area and 3-D volume of colonies in the wet and dried alginate spots, respectively. The IC50 value calculated using the 3-D volume of the colonies (9.5 μM) was less than that calculated in the 2-D area analysis (121.5 μM). We observed that the colony showed a more sensitive drug response regarding volume calculated from the 3-D image reconstructed using several confocal images than regarding colony area calculated in the 2-D analysis.

Biodiversity of the community associated with Pocillopora verrucosa (Scleractinia: Pocilloporidae) in the Red Sea

The symbiotic community associated with a scleractinian coral Pocillopora verrucosa has been studied along the Red Sea coast of Saudi Arabia from Al Wajh to the entrance of the Gulf of Aqaba. Forty colonies have been sampled from 2- to 15-m depth in 2 areas, southern and northern. Thirty-six associated species were found, including 15 symbionts and 21 species with uncertain status (SUS). The number of recorded symbiotic species was close to the statistically expected value, while SUS were rare and did not reach the value expected from the Chao 2 model. Species number and abundance positively correlated with the colony volume. Mean abundance of all species and symbionts and the number of SUS per covariate colony volume were higher in the northern area than in the southern area. This may be related to a higher habitat diversity of the surrounding reefs and to the presence of colonies with partially dead tissues in the north. These two factors have a weak impact on symbionts, but strongly affect SUS. The diversity of the pocilloporid-associated communities range from 36 to 127 species along the Indo-Pacific and Tropical East Pacific, with 9 to 19 of them being symbionts. The total species diversity varies owing to the SUS number, while the core of true symbionts includes much fewer species and is less variable. The diversity of Pocillopora symbionts in the Saudi Arabian coast (15 species) is among the highest for the studied areas in the Indo-Pacific.

Collagen gel droplet-embedded culture drug sensitivity testing in squamous cell carcinoma cell lines derived from human oral cancers: Optimal contact concentrations of cisplatin and fluorouracil.

The collagen gel droplet-embedded culture drug sensitivity test (CD-DST) is an anticancer drug sensitivity test that uses a method of three-dimensional culture of extremely small samples, and it is suited to primary cultures of human cancer cells. It is a useful method for oral squamous cell carcinoma (OSCC), in which the cancer tissues available for testing are limited. However, since the optimal contact concentrations of anticancer drugs have yet to be established in OSCC, CD-DST for detecting drug sensitivities of OSCC is currently performed by applying the optimal contact concentrations for stomach cancer. In the present study, squamous carcinoma cell lines from human oral cancer were used to investigate the optimal contact concentrations of cisplatin (CDDP) and fluorouracil (5-FU) during CD-DST for OSCC. CD-DST was performed in 7 squamous cell carcinoma cell lines derived from human oral cancers (Ca9-22, HSC-3, HSC-4, HO-1-N-1, KON, OSC-19 and SAS) using CDDP (0.15, 0.3, 1.25, 2.5, 5.0 and 10.0 µg/ml) and 5-FU (0.4, 0.9, 1.8, 3.8, 7.5, 15.0 and 30.0 µg/ml), and the optimal contact concentrations were calculated from the clinical response rate of OSCC to single-drug treatment and the in vitro efficacy rate curve. The optimal concentrations were 0.5 µg/ml for CDDP and 0.7 µg/ml for 5-FU. The antitumor efficacy of CDDP at this optimal contact concentration in CD-DST was compared to the antitumor efficacy in the nude mouse method. The T/C values, which were calculated as the ratio of the colony volume of the treatment group and the colony volume of the control group, at the optimal contact concentration of CDDP and of the nude mouse method were almost in agreement (P<0.05) and predicted clinical efficacy, indicating that the calculated optimal contact concentration is valid. Therefore, chemotherapy for OSCC based on anticancer drug sensitivity tests offers patients a greater freedom of choice and is likely to assume a greater importance in the selection of treatment from the perspectives of function preservation and quality of life, as well as representing a treatment option for unresectable, intractable or recurrent cases.

A robust platform for chemical genomics in bacterial systems.

While genetic perturbation has been the conventional route to probing bacterial systems, small molecules are showing great promise as probes for cellular complexity. Indeed, systematic investigations of chemical-genetic interactions can provide new insights into cell networks and are often starting points for understanding the mechanism of action of novel chemical probes. We have developed a robust and sensitive platform for chemical-genomic investigations in bacteria. The approach monitors colony volume kinetically using transmissive scanning measurements, enabling acquisition of growth rates and conventional endpoint measurements. We found that chemical-genomic profiles were highly sensitive to concentration, necessitating careful selection of compound concentrations. Roughly 20,000,000 data points were collected for 15 different antibiotics. While 1052 chemical-genetic interactions were identified using the conventional endpoint biomass approach, adding interactions in growth rate resulted in 1564 interactions, a 50-200% increase depending on the drug, with many genes uncharacterized or poorly annotated. The chemical-genetic interaction maps generated from these data reveal common genes likely involved in multidrug resistance. Additionally, the maps identified deletion backgrounds exhibiting class-specific potentiation, revealing conceivable targets for combination approaches to drug discovery. This open platform is highly amenable to kinetic screening of any arrayable strain collection, be it prokaryotic or eukaryotic.

Abstract 3483: Synergistic combination therapy with molecular targeted drugs in glioma stem-like cells

Abstract [Introduction] The prognosis of patients with malignant gliomas is poor despite multimodality therapies underscoring the need for novel therapeutic strategies. The majority of glioblastomas have aberrant receptor tyrosine kinase (RTK)/RAS/phosphoinositide 3 kinase (PI3K) signaling pathways and malignant glioma cells are thought to be addicted to these aberrant signaling pathways for their survival and proliferation. However, a large number of clinical trials have demonstrated that monotherapies have limited efficacy. Tumor heterogeneities and signaling redundancy and crosstalk in intracellular signaling network may imply necessity of combination treatments. Recent studies also suggested that effective methods to personalize antitumor therapy are required. However, drug sensitivity testing using tumor cells from each patient, which is one of the potent methods for personalized tumor therapy, has been unsuccessful. One possible reason of this is a technical issue regarding evaluation of clonogenicity of glioma stem-like cells (GSCs) that are thought to be key players in gliomagenesis and the disease progression and recurrence and thus targets of glioma therapy. We previously presented an effective method to evaluate clonogenicity of GSCs by using agarose-based culture system. In this study, we tested the therapeutic effects of combination treatments on GSCs using targeted drugs that affect the signaling pathways to which most glioma cells are thought to be addicted. [Materials and Methods] Human GSCs were cultured in agarose and treated with inhibitors of RTKs, non-receptor kinase or transcription factor. The colony number and volume were analyzed using GelCountTM colony counter system (Oxford Optronix Inc., UK) and Chou-Talalay combination index was analyzed. Phosphorylation of proteins was evaluated by reverse phase protein array and immunoblotting. [Results] While GSCs showed diverse sensitivity to targeted therapies even in the cells of the same glioma subtype, combinations of EGFR inhibitors with sorafenib, EGFR inhibitors with MEK inhibitors, Sorafenib with U0126, and erlotinib with BKM120 showed synergy in different GSC lines, indicating effectiveness of suppressing RTK and its downstream molecule. Combination of erlotinib with sorafenib, synergistic in the GSC11 cells, induced apoptosis and autophagic cell death associated with synergistic suppression of Akt and ERK signaling pathways and with decreased nuclear PKM2 and beta-catenin in vitro, and significantly improved survival of nude mice bearing GSC11 brain tumors compared with control and monotherapy groups. [Conclusions] Inhibition of RTK and its downstream molecule induced synergistic antitumor effects but sensitivity of GSC lines to therapies was diverse. Examining colonies initiated by GSCs obtained from individual patients may be useful for drug sensitivity testing in personalized cancer therapy. Citation Format: Takashi Shingu, Lindsay Holmes, Verlene Henry, Khatri Latha, Anupama E. Gururaj, Laura A. Gibson, Tiffany Doucette, Frederick F. Lang, Ganesh Rao, Liang Yuan, Erik P. Sulman, Nicholas P. Farrell, Waldemar Priebe, Kenneth R. Hess, Yaoqi A. Wang, Jian Hu, Oliver Bogler. Synergistic combination therapy with molecular targeted drugs in glioma stem-like cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3483. doi:10.1158/1538-7445.AM2015-3483

The influence of fire-coral colony size and agonistic behaviour of territorial damselfish on associated coral reef fish communities

Branching hydrocorals from the genus Millepora play an important ecological role in South Atlantic reefs, where branching scleractinian corals are absent. Previous studies have shown a high proportion of reef fish species using branching fire-coral colonies as shelter, breeding, and feeding sites. However, the effects of Millepora spp. colony size and how the agonistic behaviour of a competitive damselfish affect the associated reef fish community are still unknown. The present study examined how fire-coral colony volume and the presence of a highly territorial and aggressive damselfish (Brazilian endemic Stegastes fuscus) affects the reef fish community associated with the fire-coral Millepora alcicornis. M. alcicornis colonies were surveyed from September 2012 to April 2013 at Tamandaré Reefs off Northeast Brazil. Our results show that the abundance and richness of coral associated fish was positively correlated with M. alcicornis coral colony volume. Additionally, behaviour of S. fuscus, the most abundant reef fish species found associated with fire-coral colonies (almost 57% of the fish community), was also influenced by fire-coral colony volume. There was a clear trend of increased agonistic behaviour and feeding on coral polyps as colony volume increased. This trend was reversed for the non-occupational swimming category, which decreased as M. alcicornis colony volume increased. Behavioural ontogenetic changes were also detected for S. fuscus individuals. Juveniles mainly showed two distinct behaviours: sheltered on coral branches and feeding on coral polyps. In contrast, adults presented greater equitability among the behavioural categories, mostly non-occupational swimming around coral colonies and agonistic behaviour. Lastly, S. fuscus individuals actively defended fire-coral colonies from intruders. A large number of agonistic interactions occurred against potential food competitors, which were mainly roving herbivores, omnivores, and sessile invertebrate feeders. To our knowledge, the present study provides the first evidence that through habitat competition, the presence of S. fuscus may affect reef fish communities associated with M. alcicornis coral colonies. Our findings also indicate that S. fuscus uses M. alcicornis coral colonies as part of their territory for shelter and foraging. In conclusion, M. alcicornis fire-coral colonies are extremely important habitats for reef fishes and the size and presence of a territorial damselfish are relevant variables for associated reef fish community.

Cell Survival and DNA Damage in Normal Prostate Cells Irradiated Out-of-Field

Interest in out-of-field radiation dose has been increasing with the introduction of new techniques, such as volumetric modulated arc therapy (VMAT). These new techniques offer superior conformity of high-dose regions to the target compared to conventional techniques, however more normal tissue is exposed to low-dose radiation with VMAT. There is a potential increase in radiobiological effectiveness associated with lower energy photons delivered during VMAT as normal cells are exposed to a temporal change in incident photon energy spectrum. During VMAT deliveries, normal cells can be exposed to the primary radiation beam, as well as to transmission and scatter radiation. The impact of low-dose radiation, radiation-induced bystander effect and change in energy spectrum on normal cells is not well understood. The current study examined cell survival and DNA damage in normal prostate cells after exposure to out-of-field radiation both with and without the transfer of bystander factors. The effect of a change in energy spectrum out-of-field compared to in-field was also investigated. Prostate cancer (LNCaP) and normal prostate (PNT1A) cells were placed in-field and out-of-field, respectively, with the PNT1A cells being located 1 cm from the field edge when in-field cells were being irradiated with 2 Gy. Clonogenic and γ-H2AX assays were performed postirradiation to examine cell survival and DNA damage. The assays were repeated when bystander factors from the LNCaP cells were transferred to the PNT1A cells and also when the PNT1A cells were irradiated in-field to a different energy spectrum. An average out-of-field dose of 10.8 ± 4.2 cGy produced a significant reduction in colony volume and increase in the number of γ-H2AX foci/cell in the PNT1A cells compared to the sham-irradiated control cells. An adaptive response was observed in the PNT1A cells having first received a low out-of-field dose and then the bystander factors. The PNT1A cells showed a significant increase in γ-H2AX foci formation when irradiated to 20 cGy in-field in comparison to out-of-field. However, no significant difference in cell survival or colony volume was observed whether the PNT1A cells were irradiated in-field or out-of-field. Out-of-field radiation dose alone can have a damaging effect on the proliferation of PNT1A cells when a clinically relevant dose of 2 Gy is delivered in in-field. Out-of-field radiation with the transfer of bystander factors induces an adaptive response in the PNT1A cells.

Parameters that Influence the Establishment and Volume of Microcerotermes exiguus and Nasutitermes corniger Nests in an Atlantic Forest Fragment in Northeastern Brazil (Isoptera: Termitidae)

This study aimed to evaluate the parameters that influence the establishment and volume of Microcerotermes exiguus and Nasutitermes corniger nests in an Atlantic Forest fragment in northeastern Brazil. Between September and October 2011, five 1000 m² parcels (100 x 10 m; 10 m apart) were examined and the volume was estimated for all M. exiguus and N. corniger nests. Additionally, the following variables were measured: distance between nest and soil, height and diameter at breast height (DBH) of the supporting tree, and the minimum distance to the nearest nest. Data was checked for normality with the Shapiro-Wilk test and the variation between the parcels was calculated using the Kruskal-Wallis nonparametric test. The analyses were carried out using Bioestat 5.0. A total of 72 nests were sampled, of which 59 belonged to M. exiguus and 13 to N. corniger. Species occurred in different strata, which prevented direct competition between the two. DBH had the greatest influence on colony volume.

Clinical evaluation of inter-fractional organ motion using 3D ultrasound image-guided radiotherapy for positioning prostate cancer patients

Clinical evaluation of inter-fractional organ motion using 3D ultrasound image-guided radiotherapy for positioning prostate cancer patients

MORPHOLOGICAL ASSESSMENT OF EXPERIMENTAL CATHETER-ASSOCIATED INFECTION

Aim. To give morphological assessment of catheter-associated infection model in laboratory mice in conditions of immunosuppression caused by introduction of cyclophosphamide. Materials and methods. Modeling of catheter-associated infection for morphological assessment of changes in the surrounding tissues was carried out. Animals were implanted catheters with preliminary grown staphylococci biofilms; they were also once and repeatedly introduced bacterial suspensions into the tissues surrounding the catheter. Cellular composition of inflammatory infiltrate and microbial colony volume were assessed during three days. Results. Restrictive shaft round the catheter consisting of fibrin and cellular elements of inflammatory infiltrate with different thickness and composition depending on observation terms and experimental peculiarities was formed. Immunosuppression causes more marked growth of staphylococcus colonies and less pronounced inflammatory response than in case of introducing staphylococcus cultures without cyclophosphamide.

Chemosensitivity testing in ovarian cancer – prospects for the future

Individualization of treatment on the basis of in vitro chemosensitivity testing constitutes one of the aims of contemporary oncology Although previous studies report advantages resulting from chemosensitivity laboratory tests, the issue remains an area of interest. The aim of this study was to discuss chemosensitivity assay methods of ovarian cancer cells. ATP-TCA (ATP-based tumor chemosensitivity assay) is the most investigated chemosensitivity test in ovarian cancer with well-documented efficacy Potentially it is possible to use the xCELLigence system to evaluate chemosensitivity of ovarian cancer cells by measuring their colony volume but application of this method remains in the experimental phase. Optimization of ovarian cancer treatment would improve chemotherapy results, thus increasing the overall survival, improving the quality of patient life, decreasing chemotherapy-related toxicity and resulting in economic benefits owing to better drug use.