Cotrimoxazole enhances the in vitro susceptibility of Coccidioides posadasii to antifungals

The aim of the present study was to evaluate the effect of cotrimoxazole on the in vitro susceptibility of Coccidioides posadasii strains to antifungals. A total of 18 strains of C. posadasii isolated in Brazil were evaluated in this study. The assays were performed in accordance with the Clinical and Laboratory Standards Institute guidelines and the combinations were tested using the checkerboard method. The minimum inhibitory concentrations were reduced by 11, 2.4, 4.3 and 3.5 times for amphotericin B, itraconazole, fluconazole and voriconazole, respectively. Moreover, it was seen that cotrimoxazole itself inhibited C. posadasii strains in vitro. The impairment of folic acid synthesis may be a potential antifungal target for C. posadasii.     

A simple and rapid method for separation and isolation of marine algal species from naturally evolved populations

To improve the study of mixed microalgal populations, three naturally evolved marine microalgal cultures were subjected to a light crushing mechanical treatment using a silicon spatula coupled with zymolyase treatment at four concentrations: 5, 10, 20 and 25 U/ml, for 15, 30, 45 and 60 min before being observed under a microscope. The enzyme concentration of 20 U/ml after 45 min reduces the size of macroscopic microalgal aggregates and improves the microscopic observation of the different microalgal species comprising the population. There was no improvement using the higher enzyme concentration. This paper proposes a new approach to the study of naturally evolved microalgal populations which is useful for distinguishing the morphology of the different species present in the population and allowing for the identification by classical keys, and also to obtain a pure culture from an inoculum of mixed species by using a micromanipulator for cell counting.     

F1FO ATP Synthase Is Expressed at the Surface of Embryonic Rat Heart‐Derived H9c2 Cells and Is Affected by Cardiac‐Like Differentiation

Taking advantage from the peculiar features of the embryonic rat heart‐derived myoblast cell line H9c2, the present study is the first to provide evidence for the expression of F₁F_O ATP synthase and of ATPase Inhibitory Factor 1 (IF₁) on the surface of cells of cardiac origin, together documenting that they were affected through cardiac‐like differentiation. Subunits of both the catalytic F₁ sector of the complex (ATP synthase‐β) and of the peripheral stalk, responsible for the correct F₁‐F_O assembly/coupling, (OSCP, b, F6) were detected by immunofluorescence, together with IF₁. The expression of ATP synthase‐β, ATP synthase‐b and F6 were similar for parental and differentiated H9c2, while the levels of OSCP increased noticeably in differentiated cells, where the results of in situ Proximity Ligation Assay were consistent with OSCP interaction within ecto‐F₁F_O complexes. An opposite trend was shown by IF₁ whose ectopic expression appeared greater in the parental H9c2. Here, evidence for the IF₁ interaction with ecto‐F₁F_O complexes was provided. Functional analyses corroborate both sets of data. i) An F₁F_O ATP synthase contribution to the exATP production by differentiated cells suggests an augmented expression of holo‐F₁F_O ATP synthase on plasma membrane, in line with the increase of OSCP expression and interaction considered as a requirement for favoring the F₁‐F_O coupling. ii) The absence of exATP generation by the enzyme, and the finding that exATP hydrolysis was largely oligomycin‐insensitive, are in line in parental cells with the deficit of OSCP and suggest the occurrence of sub‐assemblies together evoking more regulation by IF₁. J. Cell. Biochem. 9999: 1–13, 2015. © 2015 Wiley Periodicals, Inc. J. Cell. Biochem. 117: 470–482, 2016. © 2015 Wiley Periodicals, Inc.     

Molecular phylogeny of Cryptocercus wood-roaches based on mitochondrial COII and 16S sequences, and chromosome numbers in Palearctic representatives

Woodroaches of the genus Cryptocercus are subsocial and xylophagous cockroaches, distributed in North America and Asia. Studies on male chromosome number in Nearctic species have shown that diploid numbers vary from 2n=37 to 2n=47; numbers from Palearctic species were heretofore unknown. Two hypotheses have been proposed to explain the varying number of chromosomes among Nearctic species: the serial reduction hypothesis, and the parallel scenario. We performed phylogenetic analyses of the COII gene in these species and found evidence for the topology (47(45(43(39,37), which is congruent with the serial reduction hypothesis. We also determined chromosome numbers for the first time in Palearctic species, and found Cryptocercus primarius and Cryptocercus relictus to have relatively low chromosome numbers (2n=17-21) compared to their Nearctic relatives. Finally, our study determined the phylogenetic position of Cryptocercus primarius among other Asian taxa.     

Epidermal growth factor receptor: a promising therapeutic target for colorectal cancer

The epidermal growth factor receptor is a 170,000-kd transmembrane glycoprotein involved in signaling pathways affecting cellular growth, differentiation, and proliferation. An abnormal expression of the epidermal growth factor receptor (EGFR) has been described in many human tumors and implicated in the development and prognosis of malignancies, thus representing not only a possible prognostic marker, but primarily a rational molecular target for a new class of anticancer agents. The aim of this analysis is to review the available data about the biology of the EGFR and its use as a target for a new class of anticancer agents for colorectal cancer. Several clinical trials have been reported with the use of EGFR-targeted monoclonal antibodies and tyrosine kinase inhibitors, mainly in combination with chemotherapy for advanced colorectal cancer patients. Results available so far demonstrated a manageable and acceptable toxicity profile and a promising level of activity. Many critical issues are yet unresolved, such as the optimal chemotherapy regimen to combine with anti-EGFR treatment and the most adequate patient setting. Moreover, the biological selection of colorectal tumors more likely to benefit from this treatment approach is still to be defined.     

The Medicago truncatula lysin [corrected] motif-receptor-like kinase gene family includes NFP and new nodule-expressed genes

Rhizobial Nod factors are key symbiotic signals responsible for starting the nodulation process in host legume plants. Of the six Medicago truncatula genes controlling a Nod factor signaling pathway, Nod Factor Perception (NFP) was reported as a candidate Nod factor receptor gene. Here, we provide further evidence for this by showing that NFP is a lysin [corrected] motif (LysM)-receptor-like kinase (RLK). NFP was shown both to be expressed in association with infection thread development and to be involved in the infection process. Consistent with deviations from conserved kinase domain sequences, NFP did not show autophosphorylation activity, suggesting that NFP needs to associate with an active kinase or has unusual functional characteristics different from classical kinases. Identification of nine new M. truncatula LysM-RLK genes revealed a larger family than in the nonlegumes Arabidopsis (Arabidopsis thaliana) or rice (Oryza sativa) of at least 17 members that can be divided into three subfamilies. Three LysM domains could be structurally predicted for all M. truncatula LysM-RLK proteins, whereas one subfamily, which includes NFP, was characterized by deviations from conserved kinase sequences. Most of the newly identified genes were found to be expressed in roots and nodules, suggesting this class of receptors may be more extensively involved in nodulation than was previously known.     

Insulin/insulin-like growth factor I hybrid receptors have different biological characteristics depending on the insulin receptor isoform involved

The insulin receptor (IR) and the insulin-like growth factor I receptor (IGF-IR) have a highly homologous structure, but different biological effects. Insulin and IGF-I half-receptors can heterodimerize, leading to the formation of insulin/IGF-I hybrid receptors (Hybrid-Rs) that bind IGF-I with high affinity. As the IR exists in two isoforms (IR-A and IR-B), we evaluated whether the assembly of the IGF-IR with either IR-A or IR-B moieties may differently affect Hybrid-R signaling and biological role. Three different models were studied: (a) 3T3-like mouse fibroblasts with a disrupted IGF-IR gene (R(-) cells) cotransfected with the human IGF-IR and with either the IR-A or IR-B cDNA; (b) a panel of human cell lines variably expressing the two IR isoforms; and (c) HepG2 human hepatoblastoma cells predominantly expressing either IR-A or IR-B, depending on their differentiation state. We found that Hybrid-Rs containing IR-A (Hybrid-Rs(A)) bound to and were activated by IGF-I, IGF-II, and insulin. By binding to Hybrid-Rs(A), insulin activated the IGF-I half-receptor beta-subunit and the IGF-IR-specific substrate CrkII. In contrast, Hybrid-Rs(B) bound to and were activated with high affinity by IGF-I, with low affinity by IGF-II, and insignificantly by insulin. As a consequence, cell proliferation and migration in response to both insulin and IGFs were more effectively stimulated in Hybrid-R(A)-containing cells than in Hybrid-R(B)-containing cells. The relative abundance of IR isoforms therefore affects IGF system activation through Hybrid-Rs, with important consequences for tissue-specific responses to both insulin and IGFs.     

Exceptional record of submarine cave communities from the Pleistocene of Sicily (Italy)

An Early Pleistocene benthic community, discovered inside the Rumena Cave in NW Sicily, Italy, was studied. Analysis of the community led to the recognition of several encrusting species – notably scleractinians, bryozoans, serpuloideans, cirripeds, foraminifera and brachiopods – and borings mostly referable to the ichnogenus Gastrochaenolites. All fossils detected are typical of the present‐day hard‐surface submarine cave biota, at both high taxonomic rank and species level. The biogenic crust, restricted to a few sectors of the cave but locally up to few centimetres thick, largely consist of scleractinians, mainly represented by dendrophylliids. Bryozoans and serpuloideans are also present with Hippaliosina depressa and Spiraserpula massiliensis, locally forming multi‐layered sheets and dense specimen aggregates, respectively. Basing mostly on the composition of the encrusting community and on morphological/morphometric features of some species, it has been hypothesized that at least part of the cave was blind when the crust formed, possibly at relatively shallow depth in a sheltered setting or, more probably, at higher depths, below the fair weather swell zone. Encrustations and borings on the rocky cave ceiling and on occasional speleothems broken surfaces document subsequent phases of cave submersion/colonization separated by emersion/erosion phases. The importance of the Early Pleistocene fossils of the Rumena Cave for the knowledge of submarine cave communities through time and for the understanding of sea‐level variations and the uplift of the area has been remarked.