Frequency of the Mating-Type (MAT1) in Histoplasma capsulatum Isolates from Buenos Aires,Argentina

Sex is genetically determined in Histoplasma capsulatum, governed by a sex-specific region in the genome called the mating-type locus (MAT1). We investigate the distribution of isolates of two H. capsulatum mating types in the clades circulating in Buenos Aires, Argentina. Forty-nine H. capsulatum isolates were obtained from the culture collection of the Mycology Center. The MAT1 locus was identified by PCR from the yeast suspension. The analysis of forty-eight isolates from clinical samples exhibited a ratio of 1.7 (MAT1-1:MAT1-2) and the only isolate from soil was MAT1-1. Forty-five H. capsulatum isolates belonged to the LAm B clade (H. capsulatum from Latin American group B clade) and showed a ratio of 1.8 (MAT1-1:MAT1-2). These results suggest an association between the mating types in isolates belonging to the LAm B clade. It remains to be defined whether a greater virulence should be attributed to the differences between the strains of the opposite mating type of the LAm B clade.

     

Improvement in cyst recovery and molecular detection of Giardia duodenalis from stool samples

Molecular Biology Reports - Molecular detection of Giardia duodenalis by polymerase chain reaction (PCR) is difficult in faecal samples due to inhibitors that contaminate DNA preparations, or due...     

Molecular Identification of Candida Species in the Oral Microbiota of Individuals with Down Syndrome: A Case–Control Study

Mycopathologia - Candida species are common in the human oral microbiota and may cause oral candidiasis (OC) when the microbiota equilibrium is disturbed. Immunosuppressed individuals are...     

DNA damage response in peripheral mouse blood leukocytes in vivo after variable,low-dose rate exposure

Environmental contamination and ingestion of the radionuclide Cesium-137 (137Cs) is a large concern in fallout from a nuclear reactor accident or improvised nuclear device, and highlights the need to develop biological assays for low-dose rate, internal emitter radiation. To mimic low-dose rates attributable to fallout, we have developed a VAriable Dose-rate External 137Cs irradiatoR (VADER), which can provide arbitrarily varying and progressive low-dose rate irradiations in the range of 0.1–1.2 Gy/day, while circumventing the complexities of dealing with radioactively contaminated biomaterials. We investigated the kinetics of mouse peripheral leukocytes DNA damage response in vivo after variable, low-dose rate 137Cs exposure. C57BL/6 mice were placed in the VADER over 7 days with total accumulated dose up to 2.7 Gy. Peripheral blood response including the leukocyte depletion, apoptosis as well as its signal protein p53 and DNA repair biomarker γ-H2AX was measured. The results illustrated that blood leukocyte numbers had significantly dropped by day 7. P53 levels peaked at day 2 (total dose = 0.91 Gy) and then declined; whereas, γ-H2AX fluorescence intensity (MFI) and foci number generally increased with accumulated dose and peaked at day 5 (total dose = 2.08 Gy). ROC curve analysis for γ-H2AX provided a good discrimination of accumulated dose < 2 Gy and ≥ 2 Gy, highlighting the potential of γ-H2AX MFI as a biomarker for dosimetry in a protracted, environmental exposure scenario.     

Armored with skin and bone: A combined histological and μCT-study of the exceptional integument of the Antsingy leaf chameleon Brookesia perarmata (Angel, 1933)

Madagascar's endemic ground-dwelling leaf chameleons (Brookesiinae: Brookesia Gray, 1865 + Palleon Glaw, et al., Salamandra, 2013, 49, pp. 237–238) form the sister taxon to all other chameleons (i.e., the Chamaeleoninae). They possess a limited ability of color change, a rather dull coloration, and a nonprehensile tail assisting locomotion in the leaf litter on the forest floor. Most Brookesia species can readily be recognized by peculiar spiky dorsolateral projections (“Rückensäge”), which are caused by an aberrant vertebral structure and might function as body armor to prevent predation. In addition to a pronounced Rückensäge, the Antsingy leaf chameleon Brookesia perarmata (Angel, 1933) exhibits conspicuous, acuminate tubercle scales on the lateral flanks and extremities, thereby considerably enhancing the overall armored appearance. Such structures are exceptional within the Chamaeleonidae and despite an appreciable interest in the integument of chameleons in general, the morphology of these integumentary elements remains shrouded in mystery. Using various conventional and petrographic histological approaches combined with μCT-imaging, we reveal that the tubercle scales consist of osseous, multicusped cores that are embedded within the dermis. Based on this, they consequently can be interpreted as osteoderms, which to the best of our knowledge is the first record of such for the entire Chamaeleonidae and only the second one for the entire clade Iguania. The combination of certain aspects of tissue composition (especially the presence of large, interconnected, and marrow-filled cavities) together with the precise location within the dermis (being completely enveloped by the stratum superficiale), however, discriminate the osteoderms of B. perarmata from those known for all other lepidosaurs.     

Pharmacological Characterization of a Betaine/GABA Transporter 1 (BGT1) Inhibitor Displaying an Unusual Biphasic Inhibition Profile and Anti-seizure Effects

Neurochemical Research - Focal epileptic seizures can in some patients be managed by inhibiting γ-aminobutyric acid (GABA) uptake via the GABA transporter 1 (GAT1) using tiagabine...     

Expression of the Arcelin 1 gene from Phaseolus vulgaris L. in cowpea seeds (Vigna unguiculata L.) confers bruchid resistance

Persistent decrease in the productivity of cowpea (Vigna unguiculata L.) has been partly due to attack by bruchids including Zabrotes subfasciatus and Callosobruchus maculatus. Resistance to these insects in Phaseolus vulgaris L. has been shown to be associated with arcelins, a family of seed proteins encoded by a multigenic family of lectins on the APA locus. In this work, we report the construction of an expression vector containing Arc1 gene isolated from P. vulgaris and introduced into cowpea as a strategy to confer resistance to insect attack. Following transformation and selection, feeding experiments in which C. maculatus and Z. subfasciatus were fed with transgenic (L3 and L5) and non-transgenic (control) grains showed that introduced gene protected the transgenic line. Significant differences (p < .05 and p < .01) were found in the number of eggs laid, the number of emerging insects and the loss of grain mass in L3, compared with control, for both insects. Similar observations were made in L5 with the exception of the number of laid eggs. The strategy here described may form the basis for the development of a cowpea variety tolerant to bruchids in a crop cultivated by farmers throughout Latin America and Africa.     

A synthetic biology approach for the fabrication of functional (fluorescent magnetic) bioorganic–inorganic hybrid materials in sponge primmorphs

During evolution, sponges (Porifera) have honed the genetic toolbox and biosynthetic mechanisms for the fabrication of siliceous skeletal components (spicules). Spicules carry a protein scaffold embedded within biogenic silica (biosilica) and feature an amazing range of optical, structural, and mechanical properties. Thus, it is tempting to explore the low-energy synthetic pathways of spiculogenesis for the fabrication of innovative hybrid materials. In this synthetic biology approach, the uptake of multifunctional nonbiogenic nanoparticles (fluorescent, superparamagnetic) by spicule-forming cells of bioreactor-cultivated sponge primmorphs provides access to spiculogenesis. The ingested nanoparticles were detected within intracellular vesicles resembling silicasomes (silica-rich cellular compartments) and as cytosolic clusters where they lent primmorphs fluorescent/magnetic properties. During spiculogenesis, the nanoparticles initially formed an incomplete layer around juvenile, intracellular spicules. In the mature, extracellular spicules the nanoparticles were densely arranged as a surface layer that rendered the resulting composite fluorescent and magnetic. By branching off the conventional route of solid-state materials synthesis under harsh conditions, a new pathway has been opened to a versatile platform that allows adding functionalities to growing spicules as templates in living cells, using nonbiogenic nanoscale building blocks with multiple functionalities. The magnet-assisted alignment renders this composite with its fluorescent/magnetic properties potentially suitable for application in biooptoelectronics and microelectronics (e.g., microscale on-chip waveguides for applications of optical detection and sensing).     

Side-by-side comparability of batch and continuous downstream for the production of monoclonal antibodies

Continuous processing is the future production method for monoclonal antibodies (mAbs). A fully continuous, fully automated downstream process based on disposable equipment was developed and implemented inside the MoBiDiK pilot plant. However, a study evaluating the comparability between batch and continuous processing based on product quality attributes was not conducted before. The work presented fills this gap comparing both process modes experimentally by purifying the same harvest material (side-by-side comparability). Samples were drawn at different time points and positions in the process for batch and continuous mode. Product quality attributes, product-related impurities, as well as process-related impurities were determined. The resulting polished material was processed to drug substance and further evaluated regarding storage stability and degradation behavior. The in-process control data from the continuous process showed the high degree of accuracy in providing relevant process parameters such as pH, conductivity, and protein concentration during the entire process duration. Minor differences between batch and continuous samples are expected as different processing conditions are unavoidable due to the different nature of batch and continuous processing. All tests revealed no significant differences in the intermediates and comparability in the drug substance between the samples of both process modes. The stability study of the final product also showed no differences in the stability profile during storage and forced degradation. Finally, online data analysis is presented as a powerful tool for online-monitoring of chromatography columns during continuous processing.