Diversity and spacio‐temporal distribution of mushrooms in a Nigerian savanna: implication for their conservation

We surveyed the macrofungi of an area dominated by northern Guinea savanna habitats in north‐east Nigeria. A total of 93 different species of mushrooms were found in the study area. These species belong to 29 different families, most species belonging to the family Agaricaceae, Lyophyllaceae, Bolbitiaceae, Pluteaceae and Polyporaceae. A total of 48 species belonged to the Agaricaceae, followed by Lyophyllaceae represented by 6 species. The micro‐habitats of mushrooms in the study area include wood, soil around dead tree stump, waste dump, cow dung, fallow, arable land, and 22 different living trees species. The most important habitats in term of mushroom species diversity were Parkia biglobosa, Tamarindus indica and dead wood. The Parkia biglobosa tree had the highest species richness (45) and species diversity (Shannon diversity index, SDI: 3.6). Tamarindus indica was the second, having 28 species richness and 2.7 SDI. These were followed by dead wood where 22 different mushroom species were recorded and has of 2.1 SDI. Also, these three habitats (Parkia biglobosa, dead wood and Tamarindus indica) had the highest number of mushroom species (14, 8 and 6 respectively) that were confined to them. Most of the other mushroom species were confined to only one microhabitat. There was no statistically significant difference in mushroom abundance between arable land and fallow. Collectively, the indigenous trees were associated by more mushroom species (63) than the exotic trees (20) and the indigenous trees also had significantly higher mushroom abundance than the exotic trees. However, the non‐indegenous trees had more species forming mycorrhiza than the indegenous trees, presumaby because the former were able to form symbioses with both native fungi and introduced species from their origina habitats. Inter‐annual variation of mushroom species diversity was also observed. Human activities contribute positively to mushroom diversity in the study area by creating some unique micro‐habitats that support the growth of certain unique mushroom species. Therefore, for maximum conservation of mushroom diversity, conservation measures excuding all human activities should be avoided.     

Green synthesis of tellurium-doped SnO2 nanoparticles with sulfurized g-C3N4: Insights into methylene blue photodegradation and antibacterial capability

The construction of SnO₂ nanoparticles (NPs), specifically Te-doped SnO₂ NPs, using a simple and economical co-precipitation technique has been thoroughly described in this work. NH₃ served as the reducing agent in this procedure, whilst polyethylene glycol served as the capping agent. The primary goals of our work were to investigate the physicochemical properties of the synthesized SnO₂ NPs and assess their potential use as antibacterial agents and photocatalysts. Scanning electron microscopy–energy dispersive X-ray, ultraviolet light, Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and other analytical techniques were used to thoroughly analyze the NPs. Based on the full width at half maximum of the most noticeable peaks in the XRD spectrum, the Debye–Scherrer equation was used to calculate the crystallite sizes, which indicated the presence of a single tetragonal SnO₂ phase. Particularly noteworthy was the exceptional photocatalytic activity of graphene-assisted Te-doped SnO₂ NPs, achieving an impressive decomposition efficiency of up to 98% in the photo-oxidation of methylene blue. Furthermore, our investigation delved into the antibacterial attributes of the synthesized SnO₂ NPs against Escherichia coli and Staphylococcus aureus, demonstrating inhibitory effects on both bacteria strains. This suggests potential applications for these NPs in various environmental and medical contexts.     

Histo- and cytochemical demonstration of guanosine triphosphatase activity in the outer segments of rods in the rat retina by means of a newly developed method

Summary Guanosine triphosphatase (GTPase) activity was studied histo- and cytochemically in the rod outer segments of the rat retina by means of a newly developed method. Differences in the distribution pattern of the enzyme activity exist within the outer segment: the activity is more intense at the tip of the rod outer segments near the pigment epithelium than in their proximal portion. Ultracytochemically, the new procedure reveals the reaction product of GTPase activity partly (i) on the extradisk membrane side and (ii) on the disk membranes. This result is in contrast to the cytochemical localization of guanylate cyclase (GCLase), an enzyme also localized at the tip of the rod outer segments: GCLase activity is restricted to the intradisk membrane area of the rod outer segments. The functional role of GTPase activity in the outer segments of rods is discussed.The authors dedicate this paper to Professor K. Ogawa     

2,3-dimethylnonacosane and tropane alkaloids from Hyoscyamus albus

In addition to hyoscine and hyoscyamine, a new compound isolated from the leaves and stems of Hyoscyamus albus has been characterized as 2,3-dimethylnonacosane by spectral studies.     

Molecular characterization of LbpB, the second lactoferrin-binding protein of Neisseria meningitidis

The lbpA gene of Neisseria meningitidis encodes an outer membrane lactoferrin-binding protein and shows homology to the transferrin-binding protein, TbpA. Previously, we have detected part of an open reading frame upstream of lbpA . The putative product of this open reading frame, tentatively designated lbpB showed homology to the transferrin-binding protein TbpB, suggesting that the lactoferrrin receptor, like the transferrin receptor, consists of two proteins. The complete nucleotide sequence of lbpB was determined. The gene encodes a 77.5 kDa protein, probably a lipoprotein, with homology, 33% identity to the TbpB of N . meningitidis . A unique feature of LbpB is the presence of two stretches of negatively charged residues, which might be involved in lactoferrin binding. Antisera were raised against synthetic peptides corresponding to the C-terminal part of the putative protein and used to demonstrate that the gene is indeed expressed. Consistent with the presence of a putative Fur binding site upstream of the lbpB gene, expression of both LbpA and LbpB was proved to be iron regulated in Western blot experiments. The LbpB protein appeared to be less stable than TbpB in SDS-containing sample buffer. Isogenic mutants lacking either LbpA or LbpB exhibited a reduced ability to bind lactoferrin. In contrast to the lbpB mutant, the lbpA mutant was completely unable to use lactoferrin as a sole source of iron.     

High-throughput proteomics of breast carcinoma cells: a focus on FTICR-MS

Discovery of better biomarkers for diagnosis, prognosis and therapy-response prediction is the most critical task of a scientific quest aimed at developing novel, tailormade therapies for patients with cancer. Consequently, a proteome-wide analysis, in addition to genomic studies, is an absolute requirement for a complete functional understanding of tumor biology. Ultra-sensitive, high-performance Fourier-transform ion-cyclotron resonance (FTICR) mass spectrometry (MS) currently holds an important role in fulfilling the demands of biomarker discovery. In this review, we describe the applicability of FTICR-MS for breast cancer proteomics, particularly for the analysis of complex protein mixtures obtained from a limited number of cells typically available from clinical specimens.     

Targeted nanoparticles for imaging incipient pancreatic ductal adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDAC) carries an extremely poor prognosis, typically presenting with metastasis at the time of diagnosis and exhibiting profound resistance to existing therapies. The development of molecular markers and imaging probes for incipient PDAC would enable earlier detection and guide the development of interventive therapies. Here we sought to identify novel molecular markers and to test their potential as targeted imaging agents.

Methods and Findings

Here, a phage display approach was used in a mouse model of PDAC to screen for peptides that specifically bind to cell surface antigens on PDAC cells. These screens yielded a motif that distinguishes PDAC cells from normal pancreatic duct cells in vitro, which, upon proteomics analysis, identified plectin-1 as a novel biomarker of PDAC. To assess their utility for in vivo imaging, the plectin-1 targeted peptides (PTP) were conjugated to magnetofluorescent nanoparticles. In conjunction with intravital confocal microscopy and MRI, these nanoparticles enabled detection of small PDAC and precursor lesions in engineered mouse models.

Conclusions

Our approach exploited a well-defined model of PDAC, enabling rapid identification and validation of PTP. The developed specific imaging probe, along with the discovery of plectin-1 as a novel biomarker, may have clinical utility in the diagnosis and management of PDAC in humans.