Phytochemical Investigation of Annulohypoxylon ilanense,an Endophytic Fungus Derived from Cinnamomum Species

Cultivation of the fungal strain Annulohypoxylon ilanense, an endophytic fungus isolated from the wood of medicinal plant Cinnamomum species, resulted in the isolation of one new furanoid derivative, ilanefuranone ( 1 ), one new pyrrole alkaloid, ilanepyrrolal ( 2 ), and one new biarylpropanoid derivative, ilanenoid ( 3 ), together with 22 known compounds, of which one α‐tetralone analog, (?)‐(4R)‐3,4‐dihydro‐4,6‐dihydroxynaphthalen‐1(2H)‐one ( 4 ) was isolated for the first time from a natural source. The structures were elucidated on the basis of physicochemical evidence, in‐depth NMR spectroscopic analysis, and high‐resolution mass spectrometry, and the antimycobacterial activities were also evaluated.     

Equilibrium-Phase High Spatial Resolution Contrast-Enhanced MR Angiography at 1.5T in Preoperative Imaging for Perforator Flap Breast Reconstruction

Objectives

The aim was (i) to evaluate the accuracy of equilibrium-phase high spatial resolution (EP) contrast-enhanced magnetic resonance angiography (CE-MRA) at 1.5T using a blood pool contrast agent for the preoperative evaluation of deep inferior epigastric artery perforator branches (DIEP), and (ii) to compare image quality with conventional first-pass CE-MRA.

Methods

Twenty-three consecutive patients were included. All patients underwent preoperative CE-MRA to determine quality and location of DIEP. First-pass imaging after a single bolus injection of 10 mL gadofosveset trisodium was followed by EP imaging. MRA data were compared to intra-operative findings, which served as the reference standard.

Results

There was 100% agreement between EP CE-MRA and surgical findings in identifying the single best perforator branch. All EP acquisitions were of diagnostic quality, whereas in 10 patients the quality of the first-pass acquisition was qualified as non-diagnostic. Both signal- and contrast-to-noise ratios were significantly higher for EP imaging in comparison with first-pass acquisitions (p<0.01).

Conclusions

EP CE-MRA of DIEP in the preoperative evaluation of patients undergoing a breast reconstruction procedure is highly accurate in identifying the single best perforator branch at 1.5Tesla (T). Besides accuracy, image quality of EP imaging proved superior to conventional first-pass CE-MRA.     

Antifouling substances of natural origin: Activity of benzoquinone compounds from Maesa Lanceolata against marine crustaceans

A screening of antifouling activity from plants extracts led to selection and further study of Maesa lanceolata Forssk. Two p‐benzoquinone compounds were isolated from the fruits and found to be active against Artemia salina. The anti‐crustacean activity of both p‐benzoquinones is reported for the first time.     

The synchrony effect revisited: chronotype,time of day and cognitive performance in a semantic analogy task

ABSTRACT

The synchrony effect (i.e. superior performance at optimal, inferior performance at suboptimal times of day) has been broadly studied within the context of circadian rhythms. Whether one chronotype copes better with the synchrony effect than the other received only insufficient empirical attention. We report on an applied experimental study investigating the impact of chronotype on the synchrony effect in a semantic analogy task. To detect an analogy, 36 participants (12 males) aged between 18 and 40 had to decide whether the relation between events of a source pair was mirrored by the relation between events of a target pair (e.g. to cook: to eat = to saddle: to ride). Temporal orientation of the relation within each event pair was varied corresponding either to the chronological or reverse order. Response times (RTs), error rates, as well as the psychophysiological parameters pre-experimental pupil baseline and peak pupil dilation replicate findings of a synchrony effect (shorter RTs and allocation of less cognitive resources at optimal times of day) and show an impact of chronotype (morning types generally outperforming evening types). Most importantly, morning types appeared to cope better with the synchrony effect than evening types: At suboptimal times, morning types solved the analogy detection task more efficient; that is faster with the same accuracy and without the investment of more cognitive resources. They also showed greater alertness and wakefulness indexed by greater pre-experimental pupil baselines. At optimal times of day, morning types have more cognitive resources available to allocate these to the more demanding conditions to outperform evening types. We interpret these findings to suggest that morning types are more able to adapt to unfavourable circumstances (for instance, by avoiding wasteful resource allocation when there are less cognitive resources available). Evening types appear less able to adapt to suboptimal times than morning types, because they have to deal with social jetlag and decreased self-control.     

Micrometric segregation of fluorescent membrane lipids: relevance for endogenous lipids and biogenesis in erythrocytes

Micrometric membrane lipid segregation is controversial. We addressed this issue in attached erythrocytes and found that fluorescent boron dipyrromethene (BODIPY) analogs of glycosphingolipids (GSLs) [glucosylceramide (BODIPY-GlcCer) and monosialotetrahexosylganglioside (GM1BODIPY)], sphingomyelin (BODIPY-SM), and phosphatidylcholine (BODIPY-PC inserted into the plasma membrane spontaneously gathered into distinct submicrometric domains. GM1BODIPY domains colocalized with endogenous GM1 labeled by cholera toxin. All BODIPY-lipid domains disappeared upon erythrocyte stretching, indicating control by membrane tension. Minor cholesterol depletion suppressed BODIPY-SM and BODIPY-PC but preserved BODIPY-GlcCer domains. Each type of domain exchanged constituents but assumed fixed positions, suggesting self-clustering and anchorage to spectrin. Domains showed differential association with 4.1R versus ankyrin complexes upon antibody patching. BODIPY-lipid domains also responded differentially to uncoupling at 4.1R complexes [protein kinase C (PKC) activation] and ankyrin complexes (in spherocytosis, a membrane fragility disease). These data point to micrometric compartmentation of polar BODIPY-lipids modulated by membrane tension, cholesterol, and differential association to the two nonredundant membrane:spectrin anchorage complexes. Micrometric compartmentation might play a role in erythrocyte membrane deformability and fragility.     

Ubiquitination of the glycosomal matrix protein receptor PEX5 in Trypanosoma brucei by PEX4 displays novel features

Trypanosomatids contain peroxisome-like organelles called glycosomes. Peroxisomal biogenesis involves a cytosolic receptor, PEX5, which, after its insertion into the organellar membrane, delivers proteins to the matrix. In yeasts and mammalian cells, transient PEX5 monoubiquitination at the membrane serves as the signal for its retrieval from the organelle for re-use. When its recycling is impaired, PEX5 is polyubiquitinated for proteasomal degradation. Stably monoubiquitinated TbPEX5 was detected in cytosolic fractions of Trypanosoma brucei, indicative for its role as physiological intermediate in receptor recycling. This modification's resistance to dithiothreitol suggests ubiquitin conjugation of a lysine residue. T. brucei PEX4, the functional homologue of the ubiquitin-conjugating (UBC) enzyme responsible for PEX5 monoubiquitination in yeast, was identified. It is associated with the cytosolic face of the glycosomal membrane, probably anchored by an identified putative TbPEX22. The involvement of TbPEX4 in TbPEX5 ubiquitination was demonstrated using procyclic ?PEX4 trypanosomes. Surprisingly, glycosomal matrix protein import was only mildly affected in this mutant. Since other UBC homologues were upregulated, it might be possible that these have partially rescued PEX4's function in PEX5 ubiquitination. In addition, the altered expression of UBCs, notably of candidates involved in cell-cycle control, could be responsible for observed morphological and motility defects of the ?PEX4 mutant.     

Reciprocal epithelial:endothelial paracrine interactions during thyroid development govern follicular organization and C-cells differentiation

The thyroid is a highly vascularized endocrine gland, displaying a characteristic epithelial organization in closed spheres, called follicles. Here we investigate how endothelial cells are recruited into the developing thyroid and if they control glandular organization as well as thyrocytes and C-cells differentiation. We show that endothelial cells closely surround, and then invade the expanding thyroid epithelial cell mass to become closely associated with nascent polarized follicles. This close and sustained endothelial:epithelial interaction depends on epithelial production of the angiogenic factor, Vascular Endothelial Growth Factor-A (VEGF-A), as its thyroid-specific genetic inactivation reduced the endothelial cell pool of the thyroid by >90%. Vegfa KO also displayed decreased C-cells differentiation and impaired organization of the epithelial cell mass into follicles. We developed an ex vivo model of thyroid explants that faithfully mimicks bilobation of the thyroid anlagen, endothelial and C-cells invasion, folliculogenesis and differentiation. Treatment of thyroid explants at e12.5 with a VEGFR2 inhibitor ablated the endothelial pool and reproduced ex vivo folliculogenesis defects observed in conditional Vegfa KO. In the absence of any blood supply, rescue by embryonic endothelial progenitor cells restored folliculogenesis, accelerated lumen expansion and stimulated calcitonin expression by C-cells. In conclusion, our data demonstrate that, in developing mouse thyroid, epithelial production of VEGF-A is necessary for endothelial cells recruitment and expansion. In turn, endothelial cells control epithelial reorganization in follicles and C-cells differentiation.     

Pollen morphology of Trichosanthes (Cucurbitaceae)

The pollen morphology of 37 species of Trichosanthes was examined, using light microscopy, and scanning and transmission electron microscopy. On the basis of the diverse exine ornamentation it is possible to distinguish five pollen types. With aperture characters, two of them can be subdivided into subtypes. Two types can be characterised with ultrastructural features as well. It appeared that several of the types (alt. subtypes) correspond very well to existing macromorphological groupings. The most deviating type, including only the monotypic section Trichosanthes (T. cucumerina), shows verrucate ornamentation, a thick granular infratectum and a thin, indistinctly delimited nexine. It is similar to that of the Madagascan genus Tricyclandra.     

A new pollen type in Old World Cucurbitaceae

Relatively small, microreticulate-gemmate acalymmate tetrads with coarsely verrucate inner nexine surfaces are described for the monotypic genus Borneosicyos. Tetrads represent a new pollen type in Old World Cucurbitaceae, while microreticulate-gemmate ornamentation and a verrucate inner nexine surface were unknown so far in the entire family.