Polymorphism of the Y-chromosome diallelic loci in the ethnic populations of the Altai-Sayan region

Using the data on five biallellic Y-chromosome loci (DYS199, 92R7, SRY1532, RBF5 and DYS287) polymorphism, genetic structures of the five Turkic-speaking ethnic groups of the Altai-Sayan highland (Tuvinians, Sojots, Shorians, Khakassians, and Southern Altaians (Altai-Kizhi), were described. The gene pools of the populations examined were characterized by the presence of pronounced paleo-Caucasoid component (92R7-T-lineages). The frequency of this component increased westward, reaching more than 70% in Shorians and Southern Altaians. Haplotype TAT-C (RBF5 locus) was observed in all populations, except Shorians, with the frequencies varying from 5.4% in Altai-Kizhi to 18.8% in Khakassians. The Alu-insertion in the DYS287 locus was revealed only in the Altaian sample with the frequency of 3.3%. It was established that the Altai-Sayan populations studied split into two statistically significantly different groups. One of the groups was represented by Tuvinians, Sojots, and Khakassians, while another one was comprised of Shorians and Altaians.     

Venom of the crotaline snake Atropoides nummifer (jumping viper) from Guatemala and Honduras: comparative toxicological characterization,isolation of a myotoxic phospholipase A2 homologue and neutralization by two antivenoms

A comparative study was performed on the venoms of the crotaline snake Atropoides nummifer from Guatemala and Honduras. SDS-polyacrylamide gel electrophoresis, under reducing conditions, revealed a highly similar pattern of these venoms, and between them and the venom of the same species from Costa Rica. Similar patterns were also observed in ion-exchange chromatography on CM-Shephadex C-25, in which a highly basic myotoxic fraction was present. This fraction was devoid of phospholipase A₂ activity and strongly reacted, by enzyme-immunoassay, with an antiserum against Bothrops asper myotoxin II, a Lys-49 phospholipase A₂ homologue. A basic myotoxin of 16 kDa was isolated to homogeneity from the venom of A. nummifer from Honduras, showing amino acid composition and N-terminal sequence similar to those of Lys-49 phospholipase A₂ variants previously isolated from other crotaline snake venoms. Guatemalan and Honduran A. nummifer venoms have a qualitatively similar toxicological profile, characterized by: lethal; hemorrhagic; myotoxic; edema-forming; coagulant; and defibrinating activities, although there were significant quantitative variations in some of these activities between the two venoms. Neutralization of toxic activities by two commercially-available antivenoms in the region was studied. Polyvalent antivenom produced by Instituto Clodomiro Picado was effective in the neutralization of: lethal; hemorrhagic; myotoxic; coagulant; defibrinating; and phospholipase A₂ activities, but ineffective against edema-forming activity. On the other hand, MYN polyvalent antivenom neutralized: hemorrhagic; myotoxic; coagulant; defibrinating; and phospholipase A₂ activities, albeit with a lower potency than Instituto Clodomiro Picado antivenom. MYN antivenom failed to neutralize lethal and edema-forming activities of A. nummifer venoms.     

Plant wounding affects the oviposition of Hellula undalis(F.). The impact of leaf chemistry

Crucifer specialists, such as the tropical pest Hellula undalis (F.), developed a close association to their hosts and depend on characteristic secondary plant compounds, the glucosinolates (GS), in many cases. Following tissue damage, GS undergo hydrolysis catalyzed by the enzyme myrosinase to produce a complex array of products which include isothiocyantes, cyanides, and thiocyanates depending on reaction condition and the chemical nature of the side chain. We found that mechanical plant damage to the tropical crop plant Brassica campestris L. ssp. chinensis (pak-choi) leads to increased GS content, especially of indolyl GS and affected the oviposition behaviour of H. undalis negatively. GS were detected in methanolic leaf surface extracts from intact B chinensis and Sinapis alba (L.) plants, but no hydrolysis products of GS were found in leaf extracts with methylene chloride. Furthermore, the oviposition stimulant activity of GS extracts for H. undalis was greatly reduced after hydrolysis of GS by myrosinase. These results suggest the importance of GS for inducing oviposition, thus excluding hydrolysis products as active principle. Specific produced slightly volatile hydrolysis products of GS (3-indolylmethyl-cyanide and 5-vinyloxazolidine-2-thione) reduced oviposition, when applied to the host-plant. Leaf chemistry, including volatile and non-volatile compounds, may determine oviposition in H. undalis indicating a suitable host-plant.     

Scale-up of stirring as foam disruption (SAFD) to industrial scale

Foam disruption by agitation—the stirring as foam disruption (SAFD) technique—was scaled up to pilot and production scale using Rushton turbines and an up-pumping hydrofoil impeller, the Scaba 3SHP1. The dominating mechanism behind SAFD—foam entrainment—was also demonstrated at production scale. The mechanistic model for SAFD defines a fictitious liquid velocity generated by the (upper) impeller near the dispersion surface, which is correlated with complete foam disruption. This model proved to be scalable, thus enabling the model to be used for the design of SAFD applications. Axial upward pumping impellers appeared to be more effective with respect to SAFD than Rushton turbines, as demonstrated by retrofitting a 12,000 l bioreactor, i.e. the triple Rushton configuration was compared with a mixed impeller configuration from Scaba with a 20% lower ungassed power draw. The retrofitted impeller configuration allowed 10% more broth without risking excessive foaming. In this way a substantial increase in the volumetric productivity of the bioreactor was achieved. Design recommendations for the application of SAFD are given in this paper. Using these recommendations for the design of a 30,000 l scale bioreactor, almost foamless Escherichia coli fermentations were realised. Electronic Publication     

A new coating method for cemented femur shaft implants--biocompatibility, stability during sterlization and adhesive strength]

The main cause of aseptic loosening of cemented stems in total hip arthroplasty is the hydrolytic degradation of the metal-cement interface. In order to prevent this debonding a new multilayer method of coating the implant surface involving the use of a silica-/silane technique to create a durable adhesive bond between metal stem and bone cement has been developed. The biocompatibility of all the elements of the multilayer system was confirmed using a human osteoblast cell culture test. For sterilization purposes, gamma irradiation with a 25 kGy effective dose proved to be the method of choice. The proven biocompatibility and successful sterilization of the coated implants are the main prerequisites for in-vivo usage. On the technical side, the bonding effectiveness of the multilayer coating system was demonstrated by the tensile test, which revealed a significant improvement in the adhesive strength of the cement-metal bond under prolonged moist conditions similar to those met with in the human body.     

Enzymes Related to Monoamine Transmitter Metabolism in Brain Microvessels

The activities of tyrosine hydroxylase, aromatic L-aminoacid decarboxylase, monoamine oxidase, and catechol-O-methyltransferase were measured in microvessel (capillaries and venules), parenchymal arterioles, and pial vessels from rat brains, and the decarboxylase activity was compared in brain microvessels from rabbit, cat, dog, pig, cow, baboon, and man. Cranial sympathectomy was performed to estimate the neuronal contribution to the enzyme activities. All vascular regions had substantial activities of the various enzymes studied. The activity of aromatic L-aminoacid decarboxylase in cerebral microvessels was high in rat, dog, pig, cow, and man; intermediate in rabbit and cat; and low in baboon. In addition to this enzyme, cerebral microvessels also contained tyrosine hydroxylase and monoamine oxidase. Aromatic aminoacid decarboxylase and monoamine oxidase serve an enzymatic barrier function at the microvascular level, whereas the main function of tyrosine hydroxylase is probably to synthesize monoamines within nerve terminals that remain in close association with microvessels under the conditions used for preparation of the microvascular fraction. In larger intracerebral and pial vessels monoamine oxidase was present both in the wall itself and in perivascular sympathetic nerves; the remaining two enzymes had a primarily neuronal localization. The latter types of vessels also contained catechol-O-methyltransferase in their walls.     

West Africa - A Safe Haven for Frogs? A Sub-Continental Assessment of the Chytrid Fungus (Batrachochytrium dendrobatidis)

A putative driver of global amphibian decline is the panzootic chytrid fungus Batrachochytrium dendrobatidis (Bd). While Bd has been documented across continental Africa, its distribution in West Africa remains ambiguous. We tested 793 West African amphibians (one caecilian and 61 anuran species) for the presence of Bd. The samples originated from seven West African countries - Bénin, Burkina Faso, Côte d''Ivoire, Ghana, Guinea, Liberia, Sierra Leone - and were collected from a variety of habitats, ranging from lowland rainforests to montane forests, montane grasslands to humid and dry lowland savannahs. The species investigated comprised various life-history strategies, but we focused particularly on aquatic and riparian species. We used diagnostic PCR to screen 656 specimen swabs and histology to analyse 137 specimen toe tips. All samples tested negative for Bd, including a widespread habitat generalist Hoplobatrachus occipitalis which is intensively traded on the West African food market and thus could be a potential dispersal agent for Bd. Continental fine-grained (30 arc seconds) environmental niche models suggest that Bd should have a broad distribution across West Africa that includes most of the regions and habitats that we surveyed. The surprising apparent absence of Bd in West Africa indicates that the Dahomey Gap may have acted as a natural barrier. Herein we highlight the importance of this Bd-free region of the African continent - especially for the long-term conservation of several threatened species depending on fast flowing forest streams (Conraua alleni (“Vulnerable”) and Petropedetes natator (“Near Threatened”)) as well as the “Critically Endangered” viviparous toad endemic to the montane grasslands of Mount Nimba (Nimbaphrynoides occidentalis).     

The inhibitory chloride channel activated by glutamate as well asγ-amino-butyric acid (GABA)

Summary Outside-out and inside-out patches of membrane were excised from different muscles of crayfish (Austropotamobius torrentium) and single channel currents elicited by synaptic transmitters and their analogues were measured with the patchclamp technique. If the Cl^–-concentration was high on both sides of the membrane, glutamate even at concentrations <1 M elicited low amplitude single channel currents, which were identified to be Cl^–-currents. The same channels were also activated by 10 M GABA. Glutamate and GABA showed competition in activating these inhibitory channels. Amplitude histograms of the single channel currents presented well defined peaks corresponding to 3 channel substatesI ₁,I ₂ andI ₃, with conductances of about(I₁)=22 pS in high chloride corresponding to a permeability _Cl(I₁)=3.5× 10^–14 cm³/s),(I₂)=2(I₁) and(I₃)=3(I₁). Glutamate activated preferably stateI ₁, and GABA stateI ₂, but both could activate all states at sufficient concentration. Distributions of the open times in the different states were plotted and could be fitted each with one or two exponentials described by time constants of(I₁) of 1 and 6 ms,(I₂) of 2 to 3 ms, and(I₃) or 1 to 2 ms. The burst durations had components of 3 to 4 and of 30 to 40 ms. All these durations were approximately the same when the channels were activated by glutamate and GABA. The analogue quisqualate of glutamate, as well as the GABA analogue-guanidino propionic acid also elicited the respective patterns of states of the inhibitory channel. Quisqualate is by far the most effective agonist and glutamate is more effective than GABA at the inhibitory receptor. Picrotoxin blocked activation of the inhibitory channel by GABA more effectively than by glutamate. The importance of the activation of the inhibitory channel by glutamate as well as by GABA and their analogues is discussed. Elements of a tentative reaction schema are proposed.     

Recombinant expression of ShPI-1A, a non-specific BPTI-Kunitz-type inhibitor, and its protection effect on proteolytic degradation of recombinant human miniproinsulin expressed in Pichia pastoris

Pichia pastoris is a highly successful system for the large-scale expression of heterologous proteins, with the added capability of performing most eukaryotic post-translational modifications. However, this system has one significant disadvantage - frequent proteolytic degradation by P. pastoris proteases of heterologously expressed proteins. Several methods have been proposed to address this problem, but none has proven fully effective. We tested the effectiveness of a broad specificity protease inhibitor to control proteolysis. A recombinant variant of the BPTI-Kunitz protease inhibitor ShPI-1 isolated from the sea anemone Stichodactyla helianthus, was expressed in P. pastoris. The recombinant inhibitor (rShPI-1A), containing four additional amino acids (EAEA) at the N-terminus, was folded similarly to the natural inhibitor, as assessed by circular dichroism. rShPI-1A had broad protease specificity, inhibiting serine, aspartic, and cysteine proteases similarly to the natural inhibitor. rShPI-1A protected a model protein, recombinant human miniproinsulin (rhMPI), from proteolytic degradation during expression in P. pastoris. The addition of purified rShPI-1A at the beginning of the induction phase significantly protected rhMPI from proteolysis in culture broth. The results suggest that a broad specificity protease inhibitor such as rShPI-1A can be used to improve the yield of recombinant proteins secreted from P. pastoris.