Photosynthesis and dark respiration of leaves of terrestrial carnivorous plants

Using CO₂ gasometry, net photosynthetic (P _N) and dark respiration rates (R _D) were measured in leaves or traps of 12 terrestrial carnivorous plant species usually grown in the shade. Generally, mean maximum P _N (60 nmol CO₂ g⁻¹(DM) s⁻¹ or 2.7 μmol m⁻² s⁻¹) was low in comparison with that of vascular non-carnivorous plants but was slightly higher than that reported elsewhere for carnivorous plants. After light saturation, the facultatively heliophytic plants behaved as shade-adapted plants. Mean R _D in leaves and traps of all species reached about 50% of maximum P _N and represents the high photosynthetic (metabolic) cost of carnivory.     

Steroid sulfatase and sulfuryl transferase activities in human brain tumors

Neuroactive steroids (dehydroepiandrosterone, pregnenolone) and their sulfates act as modulators of glutamate and γ-aminobutyrate type A receptors in the brain The physiological ratio of these neuromodulators is maintained by two enzymes present in the brain, namely, steroid sulfatase (STS) and steroid sulfuryl transferase (SULT).

Following previous determination of their activities in monkey brains, their activities were evaluated in human brain tumors. Radioimmunoassay and GC-MS were used for determination of products. Both enzyme activities were measured in the 55 most frequent human brain tumors (glioblastomas, pituitary adenomas, meningiomas, astrocytomas).

Significant differences were found in STS activity among investigated types of tumors except the pair of pituitary adenomas-glioblastomas, while significant differences were found in SULT activity among investigated types of tumors.

Spontaneous tendency to form clusters was revealed when both enzyme activities were taken as coordinates. Clustering indicated an individual metabolic behavior of glioblastomas and 72.7% of pituitary adenomas. Astrocytomas, meningiomas and remaining 27.3% pituitary adenomas showed similarities in both enzymes’ activities. Differences in STS and SULT activity did not depend on the sex or age of subjects.     

Systematics of the parasitic wasp genus Oxyscelio Kieffer (Hymenoptera,Platygastridae s.l.), Part I: Indo-Malayan and Palearctic fauna

The Indo-Malayan and Palearctic species of Oxyscelio (Hymenoptera: Platygastridae s.l.) are revised. A total of 90 species are recognized as valid, 19 of which are redescribed - Oxyscelio acutiventris (Kieffer), Oxyscelio brevinervis (Kieffer), Oxyscelio carinatus (Kieffer), Oxyscelio ceylonensis (Dodd), Oxyscelio consobrinus (Kieffer), Oxyscelio crassicornis (Kieffer), Oxyscelio cupularis (Kieffer), Oxyscelio dorsalis (Kieffer), Oxyscelio excavatus (Kieffer), Oxyscelio flavipennis (Kieffer), Oxyscelio florus Kononova, Oxyscelio foveatus Kieffer, Oxyscelio kiefferi Dodd, Oxyscelio magnus (Kieffer), Oxyscelio marginalis (Kieffer), Oxyscelio naraws Kozlov & Lê, Oxyscelio perpensus Kononova, Oxyscelio rugosus (Kieffer) and Oxyscelio spinosiceps (Kieffer), and 71 which are described as new - Oxyscelio aclavae Burks, sp. n., Oxyscelio amrichae Burks, sp. n., Oxyscelio anguli Burks, sp. n., Oxyscelio angustifrons Burks, sp. n., Oxyscelio angustinubbin Burks, sp. n., Oxyscelio arcus Burks, sp. n., Oxyscelio arvi Burks, sp. n., Oxyscelio asperi Burks, sp. n., Oxyscelio aureamediocritas Burks, sp. n., Oxyscelio bipunctuum Burks, sp. n., Oxyscelio brevidentis Burks, sp. n., Oxyscelio caesitas Burks, sp. n., Oxyscelio capilli Burks, sp. n., Oxyscelio capitis Burks, sp. n., Oxyscelio cavinetrion Burks, sp. n., Oxyscelio chimaerae Burks, sp. n., Oxyscelio codae Burks, sp. n., Oxyscelio convergens Burks, sp. n., Oxyscelio cordis Burks, sp. n., Oxyscelio crateris Burks, sp. n., Oxyscelio crebritas Burks, sp. n., Oxyscelio crustum Burks, sp. n., Oxyscelio cuculli Burks, sp. n., Oxyscelio cyrtomesos Burks, sp. n., Oxyscelio dasymesos Burks, sp. n., Oxyscelio dasynoton Burks, sp. n., Oxyscelio dermatoglyphes Burks, sp. n., Oxyscelio doumao Burks, sp. n., Oxyscelio fistulae Burks, sp. n., Oxyscelio flabellae Burks, sp. n., Oxyscelio flaviventris Burks, sp. n., Oxyscelio fodiens Burks, sp. n., Oxyscelio fossarum Burks, sp. n., Oxyscelio fossularum Burks, sp. n., Oxyscelio genae Burks, sp. n., Oxyscelio granorum Burks, sp. n., Oxyscelio granuli Burks, sp. n., Oxyscelio greenacus Burks, sp. n., Oxyscelio halmaherae Burks, sp. n., Oxyscelio intermedietas Burks, sp. n., Oxyscelio jaune Burks, sp. n., Oxyscelio jugi Burks, sp. n., Oxyscelio kramatos Burks, sp. n., Oxyscelio labis Burks, sp. n., Oxyscelio lacunae Burks, sp. n., Oxyscelio latinubbin Burks, sp. n., Oxyscelio latitudinis Burks, sp. n., Oxyscelio limae Burks, sp. n., Oxyscelio longiventris Burks, sp. n., Oxyscelio mesiodentis Burks, sp. n., Oxyscelio mollitia Burks, sp. n., Oxyscelio nasolabii Burks, sp. n., Oxyscelio nodorum Burks, sp. n., Oxyscelio noduli Burks, sp. n., Oxyscelio nubbin Burks, sp. n., Oxyscelio obsidiani Burks, sp. n., Oxyscelio ogive Burks, sp. n., Oxyscelio operimenti Burks, sp. n., Oxyscelio peludo Burks, sp. n., Oxyscelio planocarinae Burks, sp. n., Oxyscelio praecipitis Burks, sp. n., Oxyscelio reflectens Burks, sp. n., Oxyscelio regionis Burks, sp. n., Oxyscelio sinuum Burks, sp. n., Oxyscelio spinae Burks, sp. n., Oxyscelio striarum Burks, sp. n., Oxyscelio tecti Burks, sp. n., Oxyscelio unguis Burks, sp. n., Oxyscelio vadorum Burks, sp. n., Oxyscelio vittae Burks, sp. n. and Oxyscelio zeuctomesos. Neotypes are designated for nine species, including the type species O. foveatus Kieffer, Oxyscelio brevinervis (Kieffer), Oxyscelio bifurcatus (Kieffer), Oxyscelio frontalis (Kieffer), Oxyscelio crassicornis (Kieffer), Oxyscelio cupularis (Kieffer), Oxyscelio foveatus Kieffer, Oxyscelio kiefferi Dodd, Oxyscelio magnus (Kieffer) and Oxyscelio marginalis (Kieffer). Oxyscelio bifurcatus (Kieffer) syn. n. and Oxyscelio frontalis (Kieffer) syn. n. are synonymized under Oxyscelio consobrinus (Kieffer). The fauna is divided into 13 species groups, with six species unplaced to a group. A phylogenetic analysis employing 73 morphological characters did not find most of these groups to be monophyletic, but they are retained to aid in specimen identification. Potential biogeographical patterns are discussed, including regional variation in surface sculpture and a morphological link between Sri Lankan and Australian species.     

The same drug but a different mechanism of action: comparison of free doxorubicin with two different N-(2-hydroxypropyl)methacrylamide copolymer-bound doxorubicin conjugates in EL-4 cancer cell line

Doxorubicin is one of the most potent anti-tumor drugs with a broad spectrum of use. To reduce its toxic effect and improve its pharmacokinetics, we conjugated it to an HPMA copolymer carrier that enhances its passive accumulation within solid tumors via the EPR effect and decreases its cytotoxicity to normal, noncancer cells. In this study, we compared the antiproliferative, pro-survival, and death signals triggered in EL-4 cancer cells exposed to free doxorubicin and doxorubicin conjugated to a HPMA copolymer carrier via either enzymatically (PK1) or hydrolytically (HYD) degradable bonds. We have previously shown that the intracellular distribution of free doxorubicin, HYD, and PK1 is markedly different. Here, we demonstrated that these three agents greatly differ also in the antiproliferative effect and cell death signals they trigger. JNK phosphorylation sharply increased in cells treated with HYD, while treatment with free doxorubicin moderately decreased and treatment with PK1 even strongly decreased it. On the other hand, treatment with free doxorubicin greatly increased p38 phosphorylation, while PK1 and HYD increased it slightly. PK1 also significantly increased ERK phosphorylation, while both the free doxorubicin and HYD conjugate slightly decreased it. Long-term inhibition of JNK significantly increased both proliferation and viability of EL-4 cells treated with free doxorubicin, showing that the JNK signaling pathway could be critical for mediating cell death in EL-4 cells exposed to free doxorubicin. Both activation of caspase 3 and decreased binding activity of the p50 subunit of NFkappaB were observed in cells treated with free doxorubicin and HYD, while no such effects were seen in cells incubated with PK1. Analysis of the expression of genes involved in apoptosis and regulation of the cell cycle demonstrated that free doxorubicin and HYD have very similar mechanisms of action, while PK1 has very different characteristics.     

Structural and computational basis for potent inhibition of glutamate carboxypeptidase II by carbamate-based inhibitors

A series of carbamate-based inhibitors of glutamate carboxypeptidase II (GCPII) were designed and synthesized using ZJ-43, N-[[[(1S)-1-carboxy-3-methylbutyl]amino]carbonyl]-l-glutamic acid, as a molecular template in order to better understand the impact of replacing one of the two nitrogen atoms in the urea-based GCPII inhibitor with an oxygen atom. Compound 7 containing a C-terminal 2-oxypentanedioic acid was more potent than compound 5 containing a C-terminal glutamic acid (2-aminopentanedioic acid) despite GCPII’s preference for peptides containing an N-terminal glutamate as substrates. Subsequent crystallographic analysis revealed that ZJ-43 and its two carbamate analogs 5 and 7 with the same (S,S)-stereochemical configuration adopt a nearly identical binding mode while (R,S)-carbamate analog 8 containing a d-leucine forms a less extensive hydrogen bonding network. QM and QM/MM calculations have identified no specific interactions in the GCPII active site that would distinguish ZJ-43 from compounds 5 and 7 and attributed the higher potency of ZJ-43 and compound 7 to the free energy changes associated with the transfer of the ligand from bulk solvent to the protein active site as a result of the lower ligand strain energy and solvation/desolvation energy. Our findings underscore a broader range of factors that need to be taken into account in predicting ligand-protein binding affinity. These insights should be of particular importance in future efforts to design and develop GCPII inhibitors for optimal inhibitory potency.     

Population ecology of the endangered aquatic carnivorous macrophyte Aldrovanda vesiculosa at a naturalised site in North America

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Long‐term vegetation changes in bogs exposed to high atmospheric deposition,aerial liming and climate fluctuation

Questions: Is vegetation composition of ombrotrophic bogs with an undisturbed water regime resistant or sensitive to ongoing high atmospheric deposition and climatic changes? Location: The Sudeten Mountains (Czech Republic). Methods: Species composition of bryophytes and vascular plants was sampled in 25 permanent plots in suboceanic bogs of the Jizerské hory Mountains and in 26 permanent plots in subcontinental bogs of the Hrubý Jeseník Mountains. The permanent plots were established and first sampled in 1991. These plots were re‐sampled after 14 and 17 years, respectively. We also used historical vegetation plots (1947–1949; 1980) from the same localities in order to reveal possible changes that might start earlier. Water chemistry was analysed annually, usually three times a year. Compositional changes were analysed by PERMANOVA, β‐diversity changes by PERMDISP and other changes by t‐test and Fisher's exact test. Results: At the community level, no statistically significant changes were detected in permanent plots (PERMANOVA, PERMDISP), either in hollows or in hummocks, but the vegetation composition changed between the oldest (historical) and the newest data sets. At the level of functional groups, cover of Cyperaceae significantly decreased and cover of other herbs (excluding graminoids) and Sphagna increased in the Hrubý Jeseník Mountains, whereas no changes were detected in the Jizerské hory Mountains. Cover of ericoid dwarf shrubs has not changed in either area. At the level of particular species, the frequency of Sphagnum magellanicum, Carex limosa, Scheuchzeria palustris and Vaccinium myrtillus decreased, while the frequency of Straminergon stramineum, Sphagnum recurvum agg., Eriophorum angustifolium and Luzula sylvatica increased. These changes were more evident when recent and historical data were compared. Conclusions: When water regime is not affected, the bog vegetation seems to be rather resistant to high atmospheric deposition and climate fluctuation. A significant change of the species composition occurs only in the long‐term perspective. Particular species could, however, decrease or increase their frequencies more rapidly. For some of these species a positive or negative response to nitrogen availability was also found in other studies, whereas for other species further research is needed in order to separate the effects of atmospheric deposition and internal ecosystem dynamics.     

Revision of the Paridris nephtaspecies group (Hymenoptera, Platygastroidea, Platygastridae)

The Paridris nephta group is revised (Hymenoptera: Platygastridae). Fifteen species are described, 14 of which are new: Paridris atroxTalamas, sp. n.(Yunnan Province, China), Paridris bununTalamas, sp. n.(Taiwan), Paridris ferusTalamas, sp. n.(Thailand), Paridris kagemonoTalamas, sp. n.(Japan), Paridris minatorTalamas, sp. n.(Laos, Thailand), Paridris mystaxTalamas, sp. n.(Laos, Thailand), Paridris nephta(Kozlov) (Japan, North Korea, South Korea, Far Eastern Russia), Paridris nilakaTalamas, sp. n.(Thailand), Paridris reptilisTalamas, sp. n.(Taiwan), Paridris rugulosusTalamas, sp. n.(Laos, Vietnam), Paridris solarisTalamas, sp. n.(Laos, Thailand, Vietnam), Paridris teresTalamas, sp. n.(Vietnam), Paridris toketokiTalamas, sp. n.(Taiwan), Paridris verrucosusTalamas, sp. n.(Guangdong Province, China), Paridris yakTalamas, sp. n.(Thailand).     

Vegetation change in Southeast Greenland? Tasiilaq revisited after 40 years

Questions: Are there changes in species composition of the oceanic, Low‐Arctic tundra vegetation after 40 years? Can possible changes be attributed to climate change? Location: Ammassalik Island near Tasiilaq, Southeast Greenland. Methods: Species composition and cover of 11 key vegetation types were recorded in 110 vegetation survey plots in 1968–1969 and in 11 permanent plots in 1981. Recording was repeated in 2007. Temporal changes in species composition and cover between the surveys were tested using permutation tests linked with constrained ordinations for vegetation types, and Mann–Whitney tests for individual species. Changes in vegetation were related to climate change. Results: Although climate became warmer over the studied period, most of the vegetation types showed minor changes. The changes were most conspicuous in mire and snowbed vegetation, such as the Carex rariflora mire and Hylocomium splendens snowbed. In the C. rariflora mire, species number and cover of vascular plants and cover of bryophytes increased, whereas in the H. splendens snowbed species numbers of vascular plants, bryophytes, and also lichens increased. Lichen richness increased in the Carex bigelowii snowbed and cover of bryophytes in the Salix herbacea snowbed. No such changes occurred in the Alchemilla glomerulans meadow, Alchemilla alpina snowbed and Phyllodoce coerulea heath. There was no change of species composition within the Salix glauca scrub, A. alpina snowbed, lichen grassland and the Empetrum nigrum and Phyllodoce coerulea heaths. Most changes resulted from increasing frequency or cover of some species; there were very few decreasing species. Most of the increasing species indicate drier substrate conditions. Conclusions: Only minor changes in species composition and cover were detected in the vegetation types studied. These changes were probably caused by milder winters and warmer summers during the years before the 2007 sampling. Climate warming may have reduced the duration of snow cover and soil moisture, particularly in snowbed and mire habitats, where species composition change was most pronounced. However, its magnitude was insufficient to cause a major change in species composition. Thus, on the level of plant community types, tundra vegetation near Tasiilaq was rather stable over the last 40 years.