Meisterfeldia bitsevi—new testate amoeba of the family Cryptodifflugiidae Jung, 1942 (Amoebozoa: Arcellinida) from the tree hollow in the urban park (Moscow, Russia) with a key to species of the genus Meisterfeldia

The new testate amoeba species Meisterfeldia bitsevi is described from the linden-tree trunk hollow in the urban park in Moscow (Russia). New species is characterized by elongated ovoid bilaterally symmetrical shell, which is laterally not compressed. The shell is composed of proteinaceous material without mineral particles. Almost circular subterminal aperture is placed on ventral side. The key to the species of the genus Meisterfeldia is developed.

Cutaneous apocrine cystomatosis in three slaughter-aged pigs

Apocrine cystomatosis is a rare condition characterized by clusters of cystically dilated sweat glands or other specialized apocrine glands. Cystic dilation of cutaneous sweat glands has been described in humans, dogs, and cats, but not in pigs, to our knowledge. We describe herein linear, brown, colloid-filled cavities < 1 cm diameter within the subcutaneous fat of the entire dorsal region of carcasses of three 6-mo-old pigs. These incidental findings were detected during meat inspection in 3 different slaughterhouses in Catalonia, Spain. Histopathology revealed multiple cystic cavities lined by flattened glandular epithelium, filled with proteinaceous material, and corresponding to cystic hyperplasia of sweat glands.

Proteins are a major component of dissolved organic nitrogen (DON) leached from terrestrially aged Eucalyptus camaldulensis leaves

Environmental contextDissolved organic nitrogen often constitutes the largest portion of the dissolved nitrogen pool yet is a commonly overlooked nutrient source in aquatic systems. Terrestrially aged Eucalyptus camaldulensis, a common lowland leaf litter species, rapidly released proteinaceous dissolved organic nitrogen during the first 24h of leaching. The results indicate that terrestrial leaf litter may play an important role in satisfying nutrient demand within aquatic systems through both direct deposition and floodplain interactions. AbstractUnderstanding sources and forms of dissolved nitrogen is of critical importance to the management of aquatic systems worldwide. Dissolved organic nitrogen (DON) often constitutes the largest portion of the dissolved nitrogen pool, yet is commonly overlooked as a nutrient source to aquatic food webs, likely owing to its bound nature within organic material and the non-specific methods by which it is measured. In this study, we determined the protein and peptide (dissolved combined amino acid (DCAA)) contribution to DON leached from Eucalyptus camaldulensis leaves over 24h. The distribution of proteinaceous material in unleached and leached leaves was characterised using Fourier-transform infrared (FTIR) microspectroscopy to determine the likely source of DCAA within the leaf tissue. DCAAs were found to be a significant component (38.5%) of the leached DON; however, >90% of the leaf protein remained in the leaves after 24h. FTIR microspectroscopy shows that proteinaceous material is strongly partitioned to fungal colonised palisade cells in the leaf mesophyll, with evidence for depletion of this material after leaching. Comparison of leaching kinetics in the presence and absence of a microbial inhibitor (sodium azide) suggests that microbial uptake or adsorption commences within the timescales of these leaching experiments. The work shows that DON in the form of peptides and proteins leached from leaf litter is a likely source of bioavailable nutrients to in-stream and floodplain systems.

Acid-resistant Cretaceous thecamoebian tests from the Arabian Peninsula: a suggestion for study of agglutinated rhizopods in palynological slides

Rare specimens of Centropyxis aculeata (Ehrenberg, 1832), cf. Difflugia oblonga (Ehrenberg, 1832), Amphitrema flavum (Archer, 1869) and an unidentified spherical form (similar to a protozoan ‘cyst’ in van Hengstum et al., 2007) were observed in the palynological preparations of cutting samples from a drill-hole in southern Saudi Arabia. These thecamoebians were found in Cretaceous formations in association with typical Cretaceous spore, pollen and dinoflagellate cysts. Since the youngest rock formation in this drill-hole is of Cretaceous age, contamination due to caving from post-Cretaceous sediments is thus ruled out. Although the oldest record of thecamoebians comes from Neoproterozoic strata, their pre-Holocene occurrences are rare and patchy. Since many thecamoebian tests are autogenous and are made of acid-resistant proteinaceous material, they occur in the palynological preparations of fossil sediments. It is suggested that careful observation and search for thecamoebians in palynological slides could potentially lead to new discoveries of these microfossils from Phanerozoic sediments from all over the world.

Histopathological effects of chronic exposure to lead on kidneys of brown trout (Salmo trutta m. Fario)

The aim of the present study was to investigate the histopathological changes on the kidneys of the brown trout (Salmo trutta m. Fario) inflicted by per os lead poisoning in the 46-week experimental period. The fish were kept in well-oxygenated freshwater basins. Approximately calculated toxic doses of lead-acetate for fish were 550 mg/kg. Following the experimental period, fish organs, in particular kidneys, were examined by light microscopy. Only fish with lesions observed in kidneys were further examined by electron microscopy. An accumulation of proteinaceous material in the glomeruli of the kidneys, and thickening of the basal membrane were observed histopathologically. This proteinaceous material was also observed in the lumina of the kidney tubules. Electron microscopic examination completely supported this finding. Furthermore, to the authors' previous knowledge, undocumented damage of the brush borders of the proximal kidney tubules was also observed.

A Method for Preparing Low-Allergen Natural Rubber Latex

The free radical polymerization of dimethylaminoethyl methacrylate (DMAEMA) on the surface of particles in natural rubber latex (NRL) was carried out using an iron(ii)/tetraethylenepentamine (TEPA) redox couple initiation system, which results in significant grafting of poly(DMAEMA) to the surface of the particles. Because poly(DMAEMA) functions as an electrosteric stabilizer, this leads to increased colloidal stability, which suggests that the proteinaceous material which normally provides the colloidal stability in NRL can be displaced. This opens the way to preparing barrier products of low allergenicity, because the allergic response from NRL products arises from this proteinaceous material. Dipped and cast films were prepared from the modified NRL and were shown to be of low allergenicity using the IgE-ELISA inhibition assay. Vulcanized films prepared from the modified latex were also found to be of low allergenicity compared to a compounded film of unmodified NRL prepared under similar conditions. The barrier integrity, tensile strength, and elongation at break values of vulcanized films prepared from the modified latex were also equivalent to the unmodified film, and their water sensitivity and ageing characteristics were not significantly different. This suggests that this modified NRL can be used as an effective low-allergy latex for personal barrier products such as surgical gloves.