Application of the Red List Index as an indicator of habitat change

For the first time ever, the International Union for Conservation of Nature Red List Index for habitat types was calculated for an entire country, Finland. The RLIs were based on species threat assessments from 2000 and 2010 and included habitat definitions for all 10,131 species of 12 organism groups. The RLIs were bootstrapped to track statistically significant changes. The RLI changes of species grouped by habitats were negative for all habitat types except for forests and rural biotopes which showed a stable trend. Trends of beetles and true bugs were positive in rural and forest habitats. Other 16 observed trends of species group and habitat combinations were negative. Several trends observed were in accordance with studies focusing on particular taxa and habitats, and drivers for their change. This study demonstrates the usefulness of the RLI as a tool for observing habitat change based on species threat assessment data.     

Cellular origin of fibronectin in interspecies hybrid kidneys

The cellular origin of fibronectin in the kidney was studied in three experimental models. Immunohistochemical techniques that use cross-reacting or species-specific antibodies against mouse or chicken fibronectin were employed. In the first model studied, initially avascular mouse kidneys cultured on avian chorioallantoic membranes differentiate into epithelial kidney tubules and become vascularized by chorioallantoic vessels. Subsequently, hybrid glomeruli composed of mouse podocytes and avian endothelial-mesangial cells form. In immunohistochemical studies, cross-reacting antibodies to fibronectin stained vascular walls, tubular basement membranes, interstitium, and glomeruli of mouse kidney grafts. The species-specific antibodies reacting only with mouse fibronectin stained interstitial areas and tubular basement membranes, but showed no reaction with hybrid glomeruli and avian vascular walls. In contrast, species-specific antibodies against chicken fibronectin stained both the interstitial areas and the vascular walls as well as the endothelial-mesangial areas of the hybrid glomeruli, but did not stain the mouse-derived epithelial structures of the kidneys. In the second model, embryonic kidneys cultured under avascular conditions in vitro develop glomerular tufts, which are devoid of endothelial cells. These explants showed fluorescence staining for fibronectin only in tubular basement membranes and in interstitium. The avascular, purely epithelial glomerular bodies remained unstained. Finally, in outgrowths of separated embryonic glomeruli, the cross-reacting fibronectin antibodies revealed two populations of cells: one devoid of fibronectin and another expressing fibronectin in strong fibrillar and granular patterns. These results favor the idea that the main endogenous cellular sources for fibronectin in the embryonic kidney are the interstitial and vascular cells. All experiments presented here suggest that fibronectin is not synthesized by glomerular epithelial cells in vivo.     

Exogenous fibronectin is not required for organogenesis in vitro

The biological effect of plasma fibronectin on the differentiation of embryonic mouse kidney and tooth was studied in organ cultures. Transferrin (50 micrograms/ml) was a strong mitogen for kidney cells, whereas the addition of soluble fibronectin (50 to 250 micrograms/ml) had no detectable effect on differentiation or proliferation. The same serum-free, transferrin-containing medium did not support tooth differentiation. However, fibronectin was not a necessary serum component because fibronectin-free serum supported tooth development. It was demonstrated with antibodies specific for human fibronectin that the exogenously added human fibronectin at 50 micrograms/ml did not become incorporated to the cultured organs. Only minimal incorporation to the kidney basement membrane area was observed when fibronectin concentration was 250 micrograms/ml. The mesenchymal stroma and the basement membranes of the kidney and tooth rudiments cultured in fibronectin-free media stained intensely with conventional fibronectin antibodies, indicating endogenous production of fibronectin. Outgrowing epithelial cells from isolated kidney tubules produced fibronectin as well as laminin. The results suggest that the fibronectin found in the stroma and basement membranes is an endogenous product of the developing tissues and that plasma fibronectin is not required for in vitro organogenesis. The results also indicate that it is difficult to study the effect of fibronectin on morphogenetic processes because it may not penetrate the organ explants in vitro.     

Binding and activation of plasminogen at the surface of Staphylococcus aureus. Increase in affinity after conversion to the Lys form of the ligand.

Untreated Staphylococcus aureus cells, strain Cowan I, specifically bound 125I-Glu-plasminogen. The binding was inhibited by both unlabeled Glu-plasminogen and Glu-plasmin. The Lys form of plasminogen, which lacks the 8-kDa amino-terminal activation peptide, was approximately 100-fold more effective than the Glu form in competing with the binding of 125I-labeled Glu-plasminogen. This suggests an increase in binding affinity upon removal of the activation peptide. Fibronectin, fibrinogen and IgG, plasma components known to bind to the staphylococcal surface, did not significantly interfere with the binding. The competing activity in plasma was abolished by specifically absorbing plasminogen from the plasma sample. L-Lysine and a fragment of plasminogen containing three of the first five protein attachment domains present in the molecule (kringle structures) also competed with plasminogen for binding suggesting that the lysine-binding sites of plasminogen were involved in its interaction with staphylococci. Scatchard analysis revealed high- and low-affinity binding sites. Kd and the number of high-affinity binding sites were 1.7 nM and 780 binding sites/bacterial cell, respectively. 125I-Glu-plasminogen bound to staphylococcal surface was converted to plasmin by tissue-type plasminogen activator. The conversion took place also in the presence of plasma. If the conversion was carried out in the absence of low-molecular-mass plasmin inhibitors such as aprotinin, the bound Glu-plasmin was further converted to Lys-plasmin. The surface-bound plasmin was enzymically active, as judged by digestion of the synthetic substrate, S-2251. The plasminogen conversion shown by the present experiments not only leads to the surface-bound plasmin but seems to considerably increase the affinity of plasmin for its binding site. This may represent a physiologically relevant method for a bacterial cell to retain surface-bound active plasmin which is also protected from its soluble plasma inhibitors. This novel mechanism for staphylococci to adopt surface-bound proteolytic activity, without the interference of plasma components, may have some role in the tissue penetration and invasion of microbes during infection.     

The rate of calcium extraction during EDTA decalcification from thin bone slices as assessed with atomic absorption spectrophotometry

Summary The rate of calcium extraction with EDTA (ethylenediamine tetraacetic acid) from thin bone slices (300 m-2mm thick) was determined by aid of an atomic absorption spectrophotometer. A 0.5 mm thick bone slice was completely decalcified with 15% (0.40 M), 8% (0.22 M), and 4% (0.11 M) EDTA in 24 h, 3 days, and 5 days, respectively (vol. 15 ml, temp. 4° C, pH 7.4). At 37 and 60° C the speed of demineralization was slightly increased as compared with that at 20° C, while no difference was observed between 4 and 20° C. Bone slices with a thickness of 0.3, 0.5, 1 and 2 mm were decalcified-in the same order-in 24 h, 2, 3, and 5 days (8% EDTA, 4° C, pH 7.4). At pH 7.4, the decalcification rate was a little slower than at pH 5.0 and 8.5. Agitation did not affect the decalcifying velocity, nor did the volume of the agent, except when the volume was very small. The demineralization of ordinary bone, containing both compact and spongy bone, was found to be more rapid than that of homogeneous bone reported earlier. The acidic buffers and New Decalc^®, which served as reference substances, exerted a more vigorous decalcifying effect than EDTA. K formate/formic acid buffer, pH 3.15, demineralized a 1 mm thick bone slice in 24 h, and 2 days was needed with Na lactate/lactic acid buffer, pH 3.70. With New Decalc^®, pH 0.9, the corresponding demineralization was accomplished in 1.5 h. Atomic absorption spectrophotometer proved to be a useful tool in the evaluation of calcium extraction velocity from bone slices.     

Fibroblast surface antigen (SF): Molecular properties,distribution in vitro and in vivo,and altered expression in transformed cells

We have recently described a cell type-specific surface (SF) antigen that is deleted in chick fibroblasts transformed by Rous sarcoma virus. SF antigen is a major surface component and makes up about 0.5% of the total protein on normal cultured fibroblasts. The antigen is shed from normal cells and is present in circulation (serum, plasma), and in vivo, also, in tissue boundary membranes. The molecular equivalents of both cellular and serum SF antigen are distinct, large polypeptides, one of which (SF210, MW 210,000) is glycosylated and, on the cell surface, highly susceptible to proteases and accessible to surface iodination. Immunofluorescence and scanning electron microscopy have indicated that the antigen is located in fibrillar structures of the cell surface, membrane ridges, and processes. Human SF antigen is present in human fibroblasts and in human serum. We have recently shown that human SF antigen is identical to what has been known as the “cold-insoluble globulin” and that it shows affinity toward fibrin and fibrinogen. Our results also indicate that loss of the transformation-sensitive surface proteins is due not to loss of synthesis but to lack of insertion of the protein in the neoplastic cell surface. Both normal and transformed cells produce the SF antigen, but the latter do not retain it in the cell surface. The loss of SF antigen, a major cell surface component, from malignant cells creates an impressive difference between the surface properties of normal and malignant cells. The possible significance of SF antigen to the integrity of the normal membrane and its interaction to surrounding structures is discussed.     

Investigation of articular cartilage surface morphology with a semiquantitative scanning electron microscopic method

A semiquantitative scanning electron microscopic method for analysis of the articular cartilage surface morphology was developed. The method was based on a survey of large picture montages (ca. 70 X 100 cm) and classification of the cartilage surface changes at three levels. Computer technique was utilized in the analysis. The method ensured numerical expression and statistical treatment of the results. With this method we investigated the effects of physical exercise and immobilization on the articular cartilage of rabbit patella.     

Abundance and diversity of human-biting flies (Diptera: Ceratopogonidae, Culicidae, Tabanidae, Simuliidae) around a nickel-copper smelter at Monchegorsk, northwestern Russia.

In the summers of 2001 and 2002, we quantitatively sampled human-biting flies in twelve sites located 1.6 to 63 km from a large copper-nickel smelter at Monchegorsk on the Kola Peninsula, Russia. We collected 429 specimens of three species of Ceratopogonidae, 92 specimens of seven species of Culicidae, 76 specimens of seven species of Tabanidae, and 4,788 specimens of 19 species of Simuliidae. Culicoides chiropterus was for the first time reported from the Kola Peninsula. Catches of Culicidae and Simuliidae decreased near the smelter, presumably due to the combined action of toxicity of pollutants, pollution-induced forest damage, and decline in vertebrate density. An abundance of Ceratopogonidae and Tabanidae, the size of the most common black fly species, Simulium pusillum, and the diversity of all families did not change along the pollution gradient.     

Temporin/VesCP (T/V)-like antibiotic peptides, derived from frogs and wasps, induce migration of human monocytes and neutrophils

Summary  Several naturally occurring antimicrobial peptides, from mammals and insects, have previously been shown to be chemotactic for human inflammatory cells. Based on this evidence, ten synthetic analogs of naturally occurring antibiotic peptides from the skin secretions of three species of Ranid frogs and the venom of one species of Vespid wasp (i.e., T/V-like peptides) were tested for their abilities to induce migration of human neutrophils and monocytes. These included temporin A (TA fromRana temporaria), temporin 1P (T1P fromR. pipens), ranateurin 6 (Rana-6 fromR. catesbeiana)], three TA analogs [all D-amino acids (D-TA), reversed sequence (Rev-TA), and Pro3→Gly (G3-TA)], two frog skin-related T/V-like peptide consensus sequences (I4S10-Con and I4G10-Con), VesCP-M (VCP-M fromVespa mandarinia), and a hybrid peptide composed of portions of the insect antibiotic peptide, cecropin A (CA), and TA (CATA). TA, T1P, Rana-6, VCP-M, G3-TA, I4S10-Con, I4G10-Con, and CATA all induced cell migration at micromolar concentrations. D-TA and Rev-TA did not induce cell migration, suggesting that this process involves a chiral interaction, such as receptor binding, and also depends on the order of amino acids within TA. The results demonstrate, for the first time, that certain T/V-like antibiotic peptides are capable of inducing chemotaxis of human phagocytes and suggest that these peptides are multifunctional molecules with antimicrobial, hemolytic, and chemotactic capabilities.     

Temporin/VesCP (T/V)-like antibiotic peptides,derived from frogs and wasps,induce migration of human monocytes and neutrophils

Summary Several naturally occurring antimicrobial peptides, from mammals and insects, have previously been shown to be chemotactic for human inflammatory cells. Based on this evidence, ten synthetic analogs of naturally occurring antibiotic peptides from the skin secretions of three species of Ranid frogs and the venom of one species of Vespid wasp (i.e., T/V-like peptides) were tested for their abilities to induce migration of human neutrophils and monocytes. These included temporin A (TA fromRana temporaria), temporin 1P (T1P fromR. pipens), ranateurin 6 (Rana-6 fromR. catesbeiana)], three TA analogs [all D-amino acids (D-TA), reversed sequence (Rev-TA), and Pro3→Gly (G3-TA)], two frog skin-related T/V-like peptide consensus sequences (I4S10-Con and I4G10-Con), VesCP-M (VCP-M fromVespa mandarinia), and a hybrid peptide composed of portions of the insect antibiotic peptide, cecropin A (CA), and TA (CATA). TA, T1P, Rana-6, VCP-M, G3-TA, I4S10-Con, I4G10-Con, and CATA all induced cell migration at micromolar concentrations. D-TA and Rev-TA did not induce cell migration, suggesting that this process involves a chiral interaction, such as receptor binding, and also depends on the order of amino acids within TA. The results demonstrate, for the first time, that certain T/V-like antibiotic peptides are capable of inducing chemotaxis of human phagocytes and suggest that these peptides are multifunctional molecules with antimicrobial, hemolytic, and chemotactic capabilities.