Name typification of Umbelliferae taxa described by Joseph Franz Freyn

Thirty-three new species and 12 new infraspecific taxa of the Umbelliferae have been described by Bohemian botanist Joseph Franz Freyn (1845–1903). The names of these taxa are typified, in most cases by material preserved at the Herbarium of the Moravian Museum (BRNM) in Brno. The names of nine species proposed by Freyn are accepted in the present-day nomenclature of the family; five others are the basionyms of presently accepted names. Type material from BRNM has enabled rehabilitation of the specific status of Angelica brachyradia Freyn from Bosnia and Pastinaca dentata Freyn & Sint. from Turkey. A new nomenclatural combination is proposed (Taeniopetalum urbani (Freyn & Sint. ex H. Wolff) Pimenov). Notes on the distribution of the taxa concerned are added.     

Ectoparasites of terrestrial vertebrates inhabiting the Georgia Barrier Islands, USA: an inventory and preliminary biogeographical analysis

Aim To document ectoparasitic arthropods of terrestrial vertebrates inhabiting barrier islands and to offer preliminary interpretations. Location The coast of Georgia, USA, with most data presented for St Catherines, Sapelo, Jekyll, and Cumberland islands. Methods Ectoparasites were collected and identified from hundreds of live‐trapped mammals, birds, and reptiles. Ticks and louse‐flies were also collected by dragging or flagging a white cloth through vegetation. Some ectoparasites were recovered from host nests or roosting sites. Literature records and specimen records from the US National Tick Collection supplemented these data. Results Inventories of ectoparasite species recovered from vertebrates on each island are provided. Many new records and a small number of undescribed species are reported. Main conclusions Compared with most ectoparasite faunas associated with the same host species on the adjacent mainland, ectoparasite species diversity on the barrier islands is depauperate. Possible reasons for this phenomenon are discussed including ecological, geological, and vicariant factors. Tick faunas do not appear to be depauperate on the islands probably because immature stages attach to visiting or migrating birds. Some host‐ectoparasite associations that we recorded are atypical for mainland faunas. This trend has also been recorded in some previous surveys of insular ectoparasites and may be related to vacant ectoparasite niches on some islands.     

The hypogean invertebrate fauna of Georgia (Caucasus)

Information about the cave invertebrates of Georgia, Caucasus, is summarised, resulting in 43 troglo- and 43 stygobiont taxa reported from 64 caves. Species distribution analyses were conducted for 61 caves harbouring 58 invertebrate taxa, with the majority of caves (39) located in Apkhazeti (north-western Georgia). In 22 caves from central-west Georgia (Samegrelo, Imereti and Racha-Lechkhumi regions of west Georgia) 31 taxa are reported. Composition of cave fauna differed strongly between the caves in Apkhazeti and the central-west of Georgia. Only two taxa of the total 86 were shared, resulting in negligible similarity (Sørensen-Dice coefficient S_s=4.8%). Rarefaction indicated an increase in number of species with additional sampling could increase species richness from 58 to 76 for caves in Apkhazeti and from 31 to 69 for caves in central-west Georgia. These findings suggest that the low invertebrate species richness observed in caves of western Georgia is the result of insufficient sampling. A pairwise approach to analysing species co-occurrence showed ten positive spatial associations in 7 out of 86 cave species, all from Kveda Shakurani and Tsebelda caves. The species co-occurring in the same microhabitat require further study to understand their relationships.     

Novel influenza polymerase PB2 inhibitors for the treatment of influenza A infection

Exploration of the chemical space of known influenza polymerase PB2 inhibitor Pimodivir, was performed by our group. We synthesized and identified compounds 16a and 16b, two novel thienopyrimidine derivatives displaying anti-influenza A activity in the single digit nanomolar range in cell culture. Binding of these unique compounds in the influenza polymerase PB2 pocket was also determined using molecular modeling.     

Distribution of acid hydrolases in subcellular fractions of proliferating vs non-proliferating fibroblasts

We have employed colloidal silica (Percoll) density-gradient subcellular fractionation technique to examine the distribution of lysosomal hydrolases between intermediate vesicles (primary lysosomes) and secondary lysosomes in contact-inhibited non-proliferating vs proliferating chicken embryo fibroblasts. We find that the activities of lysosomal specific enzymes from both phases of growth are distributed within two peaks; however, the relative amounts differ markedly. In normal, non-proliferating cells approx. 60% of the total activities of cathepsin B, beta-mannosidase, alpha-fucosidase, beta-galactosidase and hexosaminidase is recovered in the heavier density fraction corresponding to secondary lysosomes, while less than 9% of the enzyme activities are recovered in the light-density peak. With transformed cells, between 16 and 22% of activity for these enzymes are recovered in the lighter density intermediate vesicle fraction, when less than 40% of the enzyme activities recovered in the heavy density fraction. beta-Glucuronidase distribution was different from that of the above enzymes. First, a more even distribution between the two lysosomal fractions was found with non-proliferating normal cells (33% in heavy-density fraction and 21% in light-density fraction), whereas more than 40% of the total enzyme activity was recovered in the lighter density fraction from transformed cells. Also, the amount of cathepsin B contained in the vesicle fractions is increased severalfold relative to that of contact-inhibited normal cells. However, the apparent differences in enzyme distribution between confluent normal and transformed cells are not found when vesicles are prepared from subconfluent, actively proliferating cultures. We have also compared the Percoll density gradient patterns of membrane vesicles from proliferating and non-proliferating human fibroblasts, since most earlier studies utilized this system. Again, we find that the majority of beta-hexosaminidase activity (41%) of contact-inhibited, confluent cells is recovered in the heavier density fraction with less than 15% in the lighter density fraction. Also, the distribution of beta-hexosaminidase between the heavy density and light density vesicle fractions is altered in homogenates from exponentially growing cells, being 22% and 26% respectively. We conclude that the distribution of lysosomal hydrolases between the two vesicle populations is growth-phase dependent and is markedly heterogeneous in proliferating cells.     

Activation of yeast enolase by Cd(II)

Activation of yeast enolase by Cd2+ exhibits properties similar to activation by the physiological cofactor Mg2+. The activity is weakly stimulated, then inhibited by increasing ionic strength. The activity increases, then falls with increasing Cd2+ concentration. The effect of pH on activity produced by Cd2+ is very similar to that produced by Mg2+, except that the Cd2+ profile is shifted one pH unit to more alkaline values, and the maximum activity of the Cd2+-enzyme is about 10% of that of the Mg2+-enzyme. The apparent kinetic parameters of Cd2+ activation show little effect of pH except for inhibition by high concentrations of Cd2+: the apparent Ki increases sharply with pH. This is interpreted as the result of Cd2+ being a less effective "catalytic" metal ion, and Cd2+ being more effective in stabilizing the enzyme at alkaline pH's. The similarity of effects of ionic strength, divalent cation, and pH may be due to interaction with the same six sites per mole of enzyme. We also characterized the dependence of what is believed to be the enzyme-catalyzed enolization of a substrate analog, D-tartronate semialdehyde-2-phosphate (TSP) on similar parameters of pH, ionic strength, etc. The putative enolization is dependent on catalytic metal ion, although the TSP binds to the conformational Cd2+-enzyme complex. The reaction is very slow and very pH dependent, increasing with pH with a midpoint of reaction velocity at pH 8.7. There is a strong qualitative correlation between pH dependencies of reaction velocity of substrate conversion and TSP enolization and absorbance of the enzyme-bound TSP enolate, whether with Mg2+ or Cd2+ as cofactor. The slowness of the Cd2+-TSP reaction is not limited by proton release or any reaction involving covalent bonds to hydrogen. The apparent reaction rate constant increases linearly with Cd2+ concentration. Addition of excess ethylenediaminetetraacetic acid reverses the TSP reaction, but again very slowly. The binding of Cd2+ to the catalytic sites is characterized by low association and dissociation rate constants.     

Neural crest origin of cardiac ganglion cells in the chick embryo: Identification and extirpation

Using interspecific grafting of neural crest between quail and chick embryos, it was determined that the cardiac ganglia originate from the cranial region (somites 1–2) of the vagal neural crest (somites 1–7). Neuronal uptake of [³H]choline was used as an index of neuronal development in the chick atrium. Normal uptake was found to be quite high between Days 8 and 14 of incubation. Following extirpation of neural crest over somites 1 to 3 at stages 8 to 10, neuronal uptake in 8-day chick atrium was decreased by 25–60% depending on the stage at which the lesion was performed. It is thought that the residual uptake represents preganglionic terminals from the dorsal motor nucleus of the vagus. Embryos with extirpations of neural crest over somites 1–3 performed at stage 9 showed the greatest decrease of neuronal choline uptake and did not live beyond 11 days of incubation. However, hearts from embryos with partial lesions (performed at stage 10) were treated on incubation Days 12 and 15 for demonstration of acetylcholinesterase in the subepicardial plexus. These hearts showed much less extensive neural plexus with sparse, small cardiac ganglia.     

Splanchnic and intestinal uptake and formation of estriol and estriol conjugates in the dog in vivo.

A loading dose of 3H-estriol was given to male dogs followed by a constant infusion. The concentrations of total radioactivity, conjugated estriol metabolites, estriol, estriol-o-glucosiduronate, estriol-16alpha-glucosiduronate, estriol-3-sulfate and estriol-3-sulfate, 16alpha-glucosiduronate were determined in plasma from the femoral artery(A), hepatic vein(HV) and superior mesenteric vein (SMV). From these values the splanchnic (100[1-HV/A]) and intestinal (100[1-SMV/A]) extractions were calculated. The mean splanchnic extraction of total radioactivity was positive (23, SE 3, P less than .01), indicating net uptake by the splanchnic area, possibly due to biliary excretion. The mean splanchnic extraction of estriol was 77, SE 1, P less than .01, also indicating net uptake. The splachnic extractions of estriol-3-glucosiduronate, estriol-16alpha-glucosiduronate and estriol-3-sulfate were negative (-15, SE 3, P less than .01; -23, SE 6, P less than .01; -31, SE 8, P less than .01 respectively) indicating net formation of these conjugates for release into the systemic circulation. The mean intestinal extraction of estriol was 12, SE 4, P less than .01, indicating net uptake by the intestine. This net uptake was associated with mean negative intestinal extractions of estriol-3-glucosiduronate (-15, SE 7, P approximately .05), estriol-3-sulfate (-33, SE 10, P less than .01) and estriol-3-sulfate, 16alpha-glucosiduronate (-53, SE 13, P less than .01), indicating net formation of these conjugates by the intestine.     

Syntheses,properties, and use of fluorescent N-(5′-phospho-4′-pyridoxyl)amines in assay of pyridoxamine (pyridoxine) 5′-phosphate oxidase

A sensitive and simple fluorometric assay has been developed for detection of pyridoxamine (pyridoxine) 5′-phosphate oxidase. This technique utilizes fluorescent N-(5′-phospho-4′-pyridoxyl)amines as substrates that, upon incubation with the oxidase, release the free fluorescent amine. The substrates were prepared by condensation of pyridoxal 5′-phosphate with fluorescent amines and subsequent hydrogenation of the Schiff bases. Since N-(1-naphthyl)ethylenediamine is 15 times less fluorescent in the intramolecularly quenched substrate than the product amine, the direct increase of fluorescence, as well as selective extraction of more fluorescent product, can be utilized for assay. The apparent K_m value for this substrate is 8 μm, which is slightly less than that of pyridoxamine 5′-phosphate; V is larger than the natural substrate value. The greater sensitivity gained by this fluorimetric method allows detection of the oxidase in smaller quantities than can be determined by the conventional colorimetric assay.