ForCenS-LGM: a dataset of planktonic foraminifera species assemblage composition for the Last Glacial Maximum

Species assemblage composition of marine microfossils offers the possibility to investigate ecological and climatological change on time scales inaccessible using conventional observations. Planktonic foraminifera - calcareous zooplankton - have an excellent fossil record and are used extensively in palaeoecology and palaeoceanography. During the Last Glacial Maximum (LGM; 19,000 - 23,000 years ago), the climate was in a radically different state. This period is therefore a key target to investigate climate and biodiversity under different conditions than today. Studying LGM climate and ecosystems indeed has a long history, yet the most recent global synthesis of planktonic foraminifera assemblage composition is now nearly two decades old. Here we present the ForCenS-LGM dataset with 2,365 species assemblage samples collected using standardised methods and with harmonised taxonomy. The data originate from marine sediments from 664 sites and present a more than 50% increase in coverage compared to previous work. The taxonomy is compatible with the most recent global core top dataset, enabling direct investigation of temporal changes in foraminifera biogeography and facilitating seawater temperature reconstructions.

Continuous reproduction of planktonic foraminifera in laboratory culture

Planktonic foraminifera were long considered obligate sexual outbreeders but recent observations have shown that nonspinose species can reproduce by multiple fission. The frequency of multiple fission appears low but the survival rate of the offspring is high and specimens approaching fission can be distinguished. We made use of this observation and established a culturing protocol aimed at enhancing the detection and frequency of fission. Using this protocol, we selectively cultured specimens of Neogloboquadrina pachyderma and raised the frequency of reproduction by fission in culture from 3% in randomly selected specimens to almost 60%. By feeding the resulting offspring different strains of live diatoms, we obtained a thriving offspring population and during the subsequent 6 months of culturing, we observed two more successive generations produced by fission. This provides evidence that in nonspinose species of planktonic foraminifera, reproduction by multiple fission is likely clonal and corresponds to the schizont phase known from benthic foraminifera. We subsequently tested if a similar culturing strategy could be applied to Globigerinita glutinata, representing a different clade of planktonic foraminifera, and we were indeed able to obtain offspring via multiple fission in this species. This work opens new avenues for laboratory-based experimental work with planktonic foraminifera.

Shared ancestry of algal symbiosis and chloroplast sequestration in foraminifera

Foraminifera are unicellular organisms that established the most diverse algal symbioses in the marine realm. Endosymbiosis repeatedly evolved in several lineages, while some engaged in the sequestration of chloroplasts, known as kleptoplasty. So far, kleptoplasty has been documented exclusively in the rotaliid clade. Here, we report the discovery of kleptoplasty in the species Hauerina diversa that belongs to the miliolid clade. The existence of kleptoplasty in the two main clades suggests that it is more widespread than previously documented. We observed chloroplasts in clustered structures within the foraminiferal cytoplasm and confirmed their functionality. Phylogenetic analysis of 18S ribosomal RNA gene sequences showed that H. diversa branches next to symbiont-bearing Alveolinidae. This finding represents evidence of of a relationship between kleptoplastic and symbiotic foraminifera.. Analysis of ribosomal genes and metagenomics revealed that alveolinid symbionts and kleptoplasts belong to the same clade, which suggests a common ancestry.

Collection of X-ray micro computed tomography images of shells of planktic foraminifera with curated taxonomy

Calcite shells of planktic foraminifera (Protista, Rhizaria) constitute a large portion of deep-sea sediments. The shells are constructed by sequential addition of partly overlapping chambers with diverse shapes, resulting in complex shell architectures, which are genetically fixed and diagnostic at the species level. The characterisation of the complete architecture requires three-dimensional imaging of the shell, including the partially or entirely covered juvenile chambers. Here we provide reconstructed x-ray micro computed tomography image stacks of 179 specimens of extant planktic foraminifera collected from plankton tows, sediment traps and surface sediments. The specimens have fully resolved and curated taxonomy and represent 43 of the currently recognised 48 holoplanktic species and subspecies. The image stacks form a basis for further applications, such as the characterisation of the architectural morphospace of the extant taxa, allowing studies of species functional ecology, calcification intensity and reconstructions of phylogenetic relationships.

Invasion success of a Lessepsian symbiont-bearing foraminifera linked to high dispersal ability, preadaptation and suppression of sexual reproduction

Among the most successful Lessepsian invaders is the symbiont-bearing benthic foraminifera Amphistegina lobifera. In its newly conquered habitat, this prolific calcifier and ecosystem engineer is exposed to environmental conditions that exceed the range of its native habitat. To disentangle which processes facilitated the invasion success of A. lobifera into the Mediterranean Sea we analyzed a ~ 1400 bp sequence fragment covering the SSU and ITS gene markers to compare the populations from its native regions and along the invasion gradient. The genetic variability was studied at four levels: intra-genomic, population, regional and geographical. We observed that the invasion is not associated with genetic differentiation, but the invasive populations show a distinct suppression of intra-genomic variability among the multiple copies of the rRNA gene. A reduced genetic diversity compared to the Indopacific is observed already in the Red Sea populations and their high dispersal potential into the Mediterranean appears consistent with a bridgehead effect resulting from the postglacial expansion from the Indian Ocean into the Red Sea. We conclude that the genetic structure of the invasive populations reflects two processes: high dispersal ability of the Red Sea source population pre-adapted to Mediterranean conditions and a likely suppression of sexual reproduction in the invader. This discovery provides a new perspective on the cost of invasion in marine protists: The success of the invasive A. lobifera in the Mediterranean Sea comes at the cost of abandonment of sexual reproduction.

The FORCIS database: A global census of planktonic Foraminifera from ocean waters

Planktonic Foraminifera are unique paleo-environmental indicators through their excellent fossil record in ocean sediments. Their distribution and diversity are affected by different environmental factors including anthropogenically forced ocean and climate change. Until now, historical changes in their distribution have not been fully assessed at the global scale. Here we present the FORCIS (Foraminifera Response to Climatic Stress) database on foraminiferal species diversity and distribution in the global ocean from 1910 until 2018 including published and unpublished data. The FORCIS database includes data collected using plankton tows, continuous plankton recorder, sediment traps and plankton pump, and contains ~22,000, ~157,000, ~9,000, ~400 subsamples, respectively (one single plankton aliquot collected within a depth range, time interval, size fraction range, at a single location) from each category. Our database provides a perspective of the distribution patterns of planktonic Foraminifera in the global ocean on large spatial (regional to basin scale, and at the vertical scale), and temporal (seasonal to interdecadal) scales over the past century.

Macroevolutionary patterns in intragenomic rDNA variability among planktonic foraminifera

Ribosomal intragenomic variability in prokaryotes and eukaryotes is a genomic feature commonly studied for its inflationary impact on molecular diversity assessments. However, the evolutionary mechanisms and distribution of this phenomenon within a microbial group are rarely explored. Here, we investigate the intragenomic variability in 33 species of planktonic foraminifera, calcifying marine protists, by inspecting 2,403 partial SSU sequences obtained from single-cell clone libraries. Our analyses show that polymorphisms are common among planktonic foraminifera species, but the number of polymorphic sites significantly differs among clades. With our molecular simulations, we could assess that most of these mutations are located in paired regions that do not affect the secondary structure of the SSU fragment. Finally, by mapping the number of polymorphic sites on the phylogeny of the clades, we were able to discuss the evolution and potential sources of intragenomic variability in planktonic foraminifera, linking this trait to the distinctive nuclear and genomic dynamics of this microbial group.

Plankton response to global warming is characterized by non-uniform shifts in assemblage composition since the last ice age

Biodiversity is expected to change in response to future global warming. However, it is difficult to predict how species will track the ongoing climate change. Here we use the fossil record of planktonic foraminifera to assess how biodiversity responded to climate change with a magnitude comparable to future anthropogenic warming. We compiled time series of planktonic foraminifera assemblages, covering the time from the last ice age across the deglaciation to the current warm period. Planktonic foraminifera assemblages shifted immediately when temperature began to rise at the end of the last ice age and continued to change until approximately 5,000 years ago, even though global temperature remained relatively stable during the last 11,000 years. The biotic response was largest in the mid latitudes and dominated by range expansion, which resulted in the emergence of new assemblages without analogues in the glacial ocean. Our results indicate that the plankton response to global warming was spatially heterogeneous and did not track temperature change uniformly over the past 24,000 years. Climate change led to the establishment of new assemblages and possibly new ecological interactions, which suggests that current anthropogenic warming may lead to new, different plankton community composition.

Decadal trend of plankton community change and habitat shoaling in the Arctic gateway recorded by planktonic foraminifera

The Fram Strait plays a crucial role in regulating the heat and sea-ice dynamics in the Arctic. In response to the ongoing global warming, the marine biota of this Arctic gateway is experiencing significant changes with increasing advection of Atlantic species. The footprint of this 'Atlantification' has been identified in isolated observations across the plankton community, but a systematic, multi-decadal perspective on how regional climate change facilitates the invasion of Atlantic species and affects the ecology of the resident species is lacking. Here we evaluate a series of 51 depth-resolved plankton profiles collected in the Fram Strait during seven surveys between 1985 and 2015, using planktonic foraminifera as a proxy for changes in both the pelagic community composition and species vertical habitat depth. The time series reveals a progressive shift towards more Atlantic species, occurring independently of changes in local environmental conditions. We conclude that this trend is reflecting higher production of the Atlantic species in the Nordic Seas, from where they are advected into the Fram Strait. At the same time, we observe the ongoing extensive sea-ice export from the Arctic and associated cooling-induced decline in density and habitat shoaling of the subpolar Turborotalita quinqueloba, whereas the resident Neogloboquadrina pachyderma persists. As a result, the planktonic foraminiferal community and vertical structure in the Fram Strait shift to a new state, driven by both remote forcing of the Atlantic invaders and local climatic changes acting on the resident species. The strong summer export of Arctic sea ice has so far buffered larger plankton transformation. We predict that if the sea-ice export will decrease, the Arctic gateway will experience rapid restructuring of the pelagic community, even in the absence of further warming. Such a large change in the gateway region will likely propagate into the Arctic proper.

The combined effects of rising temperature and salinity may halt the future proliferation of symbiont-bearing foraminifera as ecosystem engineers

Rising sea surface temperatures and extreme heat waves are affecting symbiont-bearing tropical calcifiers such as corals and Large Benthic Foraminifera (LBF). In many ecosystems, parallel to warming, global change unleashes a host of additional changes to the marine environment, and the combined effect of such multiple stressors may be far greater than those of temperature alone. One such additional stressor, positively correlated to temperature in evaporation-dominated shallow-water settings is rising salinity. Here we used laboratory culture experiments to evaluate the combined thermohaline tolerance of one of the most common LBF species and carbonate producer, Amphistegina lobifera. The experiments were done under ambient (39 psu) and modified (30, 45, 50 psu) salinities and at optimum (25 °C) and warm temperatures (32 °C). Calcification of the A. lobifera holobiont was evaluated by measuring alkalinity loss in the culturing seawater, as an indication of carbonate ion uptake. The vitality of the symbionts was determined by monitoring pigment loss of the holobiont and their photosynthetic performances by measuring dissolved oxygen. We further evaluated the growth of Peneroplis (P. pertusus and P. planatus), a Rhodophyta bearing LBF, which is known to tolerate high temperatures, under elevated salinities. The results show that the A. lobifera holobiont exhibits optimal performance at 39 psu and 25 °C, and its growth is significantly reduced upon exposure to 30, 45, 50 psu and under all 32 °C treatments. Salinity and temperature exhibit a significant interaction, with synergic effects observed in most treatments. Our results confirm that Peneroplis has a higher tolerance to elevated temperature and salinity compared to A. lobifera, implying that a further increase of salinity and temperatures may result in a regime shift from Amphistegina- to Peneroplis-dominated assemblages.

High variability in SSU rDNA gene copy number among planktonic foraminifera revealed by single-cell qPCR

Metabarcoding has become the workhorse of community ecology. Sequencing a taxonomically informative DNA fragment from environmental samples gives fast access to community composition across taxonomic groups, but it relies on the assumption that the number of sequences for each taxon correlates with its abundance in the sampled community. However, gene copy number varies among and within taxa, and the extent of this variability must therefore be considered when interpreting community composition data derived from environmental sequencing. Here we measured with single-cell qPCR the SSU rDNA gene copy number of 139 specimens of five species of planktonic foraminifera. We found that the average gene copy number varied between of ~4000 to ~50,000 gene copies between species, and individuals of the same species can carry between ~300 to more than 350,000 gene copies. This variability cannot be explained by differences in cell size and considering all plausible sources of bias, we conclude that this variability likely reflects dynamic genomic processes acting during the life cycle. We used the observed variability to model its impact on metabarcoding and found that the application of a correcting factor at species level may correct the derived relative abundances, provided sufficiently large populations have been sampled.

474 Effectiveness of Platelet Rich Plasma in the Treatment of Recalcitrant Shoulder Pathology

Aim

To assess the outcome of platelet rich plasma injections (PRP) in patients with recalcitrant shoulder pathology using steroid injections as a control.

Method

This was a pragmatic retrospective analysis of patients treated for recalcitrant shoulder pathology between October 2018 to March 2019 with either PRP or steroid injection.

Results

In the PRP group 10 patients (n = 15) had previous steroid injections and 7 had previous surgery. 2 progressed to shoulder replacement. 5 have progressed to arthropathy. 4 patients were discharged due to improving symptoms. In the steroid group 2 patients (n = 15) were lost to follow up, 0 had previous surgery and 1 had a previous steroid injection. 6 were discharged due to improving symptoms. The average time to discharge post procedure was 241 days for PRP and 173 days for the steroid group. No complications were noted in either group.

Conclusions

Our findings show that PRP injections are a safe and effective treatment for cases of recalcitrant shoulder pathology leading to a 27% success rate for patients who have required steroid injections or arthroscopy in the past. In patients with arthropathy, PRP only has a short effect and should only be offered to patients that are unable to have surgery either due to high risk or patient choice. PRP requires a centrifuge machine and an operating theatre, thus incurring higher costs compared to steroid injections which may be given in clinic. Steroid injections should therefore remain the first line of treatment for recalcitrant shoulder pathology.

Liver transplantation using grafts from donors after circulatory death - the first Czech Republic experience

INTRODUCTION

Liver transplantation is established as a lifesaving procedure for patients with acute and chronic liver failure, as well as certain selected malignancies. Due to a continuing organ shortage and ever-growing patient waiting lists, donation after cardiac death (DCD) is becoming more frequently utilized in order to close the gap between “supply and demand”.

METHODS

A retrospective analysis of DCD and subsequent liver transplantations was performed.

RESULTS

From May 2016 to September 2019, a total of 9 DCD liver transplantations were performed in our institution. All cases except one were primary liver transplantations. The recipients comprised 5 (56%) males and 4 (44%) females. The mean DCD donor age was 41±12 (22-57) years, with ventilation duration of 7±1 days and warm ischemia time 19±3 minutes. The average recipient age was 51±22 (4-73) years, with an average cold ischemia 3h:59m±27m and manipulation time of 23±5 minutes. Periprocedural mortality was 1 (11%). Hepatitis C recurrence was documented in 1 (11%) patient. The mean follow-up time was 19±13 (7-37) months. Until now, we have not observed any signs of ischemic cholangiopathy.

CONCLUSION

DCD liver transplantation allows us to enlarge the pool of potential liver grafts, thus decreasing the time spent on the liver recipient waiting list. This paper documents the first series of DCD liver transplantations in the Czech Republic.

Planktonic foraminifera eDNA signature deposited on the seafloor remains preserved after burial in marine sediments

Environmental DNA (eDNA) metabarcoding of marine sediments has revealed large amounts of sequences assigned to planktonic taxa. How this planktonic eDNA is delivered on the seafloor and preserved in the sediment is not well understood. We address these questions by comparing metabarcoding and microfossil foraminifera assemblages in sediment cores taken off Newfoundland across a strong ecological gradient. We detected planktonic foraminifera eDNA down to 30 cm and observed that the planktonic/benthic amplicon ratio changed with depth. The relative proportion of planktonic foraminiferal amplicons remained low from the surface down to 10 cm, likely due to the presence of DNA from living benthic foraminifera. Below 10 cm, the relative proportion of planktonic foraminifera amplicons rocketed, likely reflecting the higher proportion of planktonic eDNA in the DNA burial flux. In addition, the microfossil and metabarcoding assemblages showed a congruent pattern indicating that planktonic foraminifera eDNA is deposited without substantial lateral advection and preserves regional biogeographical patterns, indicating deposition by a similar mechanism as the foraminiferal shells. Our study shows that the planktonic eDNA preserved in marine sediments has the potential to record climatic and biotic changes in the pelagic community with the same spatial and temporal resolution as microfossils.

Intraspecific size variation in planktonic foraminifera cannot be consistently predicted by the environment

The size structure of plankton communities is an important determinant of their functions in marine ecosystems. However, few studies have quantified how organism size varies within species across biogeographical scales. Here, we investigate how planktonic foraminifera, a ubiquitous zooplankton group, vary in size across the tropical and subtropical oceans of the world. Using a recently digitized museum collection, we measured shell area of 3,799 individuals of nine extant species in 53 seafloor sediments. We first analyzed potential size biases in the collection. Then, for each site, we obtained corresponding local values of mean annual sea-surface temperature (SST), net primary productivity (NPP), and relative abundance of each species. Given former studies, we expected species to reach largest shell sizes under optimal environmental conditions. In contrast, we observe that species differ in how much their size variation is explained by SST, NPP, and/or relative abundance. While some species have predictable size variation given these variables (Trilobatus sacculifer, Globigerinoides conglobatus, Globigerinella siphonifera, Pulleniatina obliquiloculata, Globorotalia truncatulinoides), other species show no relationships between size and the studied covariates (Globigerinoides ruber, Neogloboquadrina dutertrei, Globorotalia menardii, Globoconella inflata). By incorporating intraspecific variation and sampling broader geographical ranges compared to previous studies, we conclude that shell size variation in planktonic foraminifera species cannot be consistently predicted by the environment. Our results caution against the general use of size as a proxy for planktonic foraminifera environmental optima. More generally, our work highlights the utility of natural history collections and the importance of studying intraspecific variation when interpreting macroecological patterns.

High dispersal capacity and biogeographic breaks shape the genetic diversity of a globally distributed reef-dwelling calcifier

Understanding the role of dispersal and adaptation in the evolutionary history of marine species is essential for predicting their response to changing conditions. We analyzed patterns of genetic differentiation in the key tropical calcifying species of large benthic foraminifera Amphistegina lobifera to reveal the evolutionary processes responsible for its biogeographic distribution. We collected specimens from 16 sites encompassing the entire range of the species and analyzed hypervariable fragments of the 18S SSU rDNA marker. We identified six hierarchically organized genotypes with mutually exclusive distribution organized along a longitudinal gradient. The distribution is consistent with diversification occurring in the Indo-West Pacific (IWP) followed by dispersal toward the periphery. This pattern can be explained by: (a) high dispersal capacity of the species, (b) habitat heterogeneity driving more recent differentiation in the IWP, and (c) ecological-scale processes such as niche incumbency reinforcing patterns of genotype mutual exclusion. The dispersal potential of this species drives the ongoing range expansion into the Mediterranean Sea, indicating that A. lobifera is able to expand its distribution by tracking increases in temperature. The genetic structure reveals recent diversification and high rate of extinction in the evolutionary history of the clade suggesting a high turnover rate of the diversity at the cryptic level. This diversification dynamic combined with high dispersal potential, allowed the species to maintain a widespread distribution over periods of geological and climatic upheaval. These characteristics are likely to allow the species to modify its geographic range in response to ongoing global warming without requiring genetic differentiation.

Assessing forest availability for wood supply in Europe

The quantification of forests available for wood supply (FAWS) is essential for decision-making with regard to the maintenance and enhancement of forest resources and their contribution to the global carbon cycle. The provision of harmonized forest statistics is necessary for the development of forest associated policies and to support decision-making. Based on the National Forest Inventory (NFI) data from 13 European countries, we quantify and compare the areas and aboveground dry biomass (AGB) of FAWS and forest not available for wood supply (FNAWS) according to national and reference definitions by determining the restrictions and associated thresholds considered at country level to classify forests as FAWS or FNAWS. FAWS represent between 75 and 95 % of forest area and AGB for most of the countries in this study. Economic restrictions are the main factor limiting the availability of forests for wood supply, accounting for 67 % of the total FNAWS area and 56 % of the total FNAWS AGB, followed by environmental restrictions. Profitability, slope and accessibility as economic restrictions, and protected areas as environmental restrictions are the factors most frequently considered to distinguish between FAWS and FNAWS. With respect to the area of FNAWS associated with each type of restriction, an overlap among the restrictions of 13.7 % was identified. For most countries, the differences in the FNAWS areas and AGB estimates between national and reference definitions ranged from 0 to 5 %. These results highlight the applicability and reliability of a FAWS reference definition for most of the European countries studied, thereby facilitating a consistent approach to assess forests available for supply for the purpose of international reporting.

Genetic and morphological divergence in the warm-water planktonic foraminifera genus Globigerinoides

The planktonic foraminifera genus Globigerinoides provides a prime example of a species-rich genus in which genetic and morphological divergence are uncorrelated. To shed light on the evolutionary processes that lead to the present-day diversity of Globigerinoides, we investigated the genetic, ecological and morphological divergence of its constituent species. We assembled a global collection of single-cell barcode sequences and show that the genus consists of eight distinct genetic types organized in five extant morphospecies. Based on morphological evidence, we reassign the species Globoturborotalita tenella to Globigerinoides and amend Globigerinoides ruber by formally proposing two new subspecies, G. ruber albus n.subsp. and G. ruber ruber in order to express their subspecies level distinction and to replace the informal G. ruber "white" and G. ruber "pink", respectively. The genetic types within G. ruber and Globigerinoides elongatus show a combination of endemism and coexistence, with little evidence for ecological differentiation. CT-scanning and ontogeny analysis reveal that the diagnostic differences in adult morphologies could be explained by alterations of the ontogenetic trajectories towards final (reproductive) size. This indicates that heterochrony may have caused the observed decoupling between genetic and morphological diversification within the genus. We find little evidence for environmental forcing of either the genetic or the morphological diversification, which allude to biotic interactions such as symbiosis, as the driver of speciation in Globigerinoides.

Unassigned diversity of planktonic foraminifera from environmental sequencing revealed as known but neglected species

Most research on extant planktonic foraminifera has been directed towards larger species (>0.150 mm) which can be easily manipulated, counted and yield enough calcite for geochemical analyses. This has drawn attention towards the macroperforate clade and created an impression of their numerical and ecological dominance. Drawing such conclusions from the study of such “giants” is a dangerous path. There were times in the evolutionary history of planktonic foraminifera when all species were smaller than 0.1 mm and indeed numerous small taxa, mainly from the microperforate clade, have been formally described from the modern plankton. The significance of these small, obscure and neglected species is poorly characterized and their relationship to the newly discovered hyperabundant but uncharacterized lineages of planktonic foraminifera in metabarcoding datasets is unknown. To determine, who is hiding in the metabarcoding datasets, we carried out an extensive sequencing of 18S rDNA targeted at small and obscure species. The sequences of the newly characterized small and obscure taxa match many of the previously uncharacterized lineages found in metabarcoding data. This indicates that most of the modern diversity in planktonic foraminifera has been taxonomically captured, but the role of the small and neglected taxa has been severely underestimated.

Diverse Internal Symbiont Community in the Endosymbiotic Foraminifera Pararotalia calcariformata: Implications for Symbiont Shuffling Under Thermal Stress

Many shallow-water tropical and subtropical foraminifera engage in photosymbiosis with eukaryotic microalgae. Some of these foraminifera appear to harbor a diverse consortium of endosymbiotic algae within a single host. Such apparent ability to contain different symbionts could facilitate change in symbiont community composition (symbiont shuffling) and mediate the ecological success of the group in a changing environment. However, the discovery of the intra-individual symbiont diversity was thus far based on symbiont culturing, which provides strong constraints on the vitality of the identified algae but provides poor constraints on their initial abundance and thus functional relevance to the host. Here we analyze the algal symbiont diversity in Pararotalia calcariformata, a benthic foraminifera sampled at four stations, inside and outside of a thermal plume in the eastern Mediterranean coast of Israel. This species has recently invaded the Mediterranean, is unusually thermally tolerant and was described previously to host at least one different diatom symbiont than other symbiont-bearing foraminifera. Our results using genotyping and isolation of algae in culture medium, confirm multiple associations with different diatom species within the same individual. Both methods revealed spatially consistent symbiont associations and identified the most common symbiont as a pelagic diatom Minutocellus polymorphus. In one case, an alternative dominant symbiont, the diatom Navicula sp., was detected by genotyping. This diatom was the third most abundant species identified using standard algae culturing method. This method further revealed a spatially consistent pattern in symbiont diversity of a total of seventeen identified diatom species, across the studied localities. Collectively, these results indicate that P. calcariformata hosts a diverse consortium of diatom endosymbionts, where different members can become numerically dominant and thus functionally relevant in a changing environment.

Foraminiferal single chamber analyses of heavy metals as a tool for monitoring permanent and short term anthropogenic footprints

In order to establish environmentally sustainable industries there is a need for high-resolution temporal and spatial monitoring of heavy metal pollutants even at low concentrations before they become hazardous for local ecosystems. Here we present single chamber records of Cu, Zn and Pb in shells of two benthic foraminifera species with different shell types from two shallow coastal stations in Israel: An area adjacent to an electrical power plant and desalination factory (Hadera) and an industrially free nature reserve (Nachsholim). Records of both foraminifera species show elevated metal concentrations in Hadera clearly identifying the footprint of the local industrial facilities. Moreover, short-term events of elevated Cu and Pb concentrations were detected by single chamber analyses. This study demonstrates the potential of using heavy metals anomalies in foraminiferal single chambers as a tool for detecting the industrial footprint of coastal facilities as well as short term events of elevated heavy metals.

Disentangling thermal stress responses in a reef-calcifier and its photosymbionts by shotgun proteomics

The proliferation of key marine ecological engineers and carbonate producers often relies on their association with photosymbiotic algae. Evaluating stress responses of these organisms is important to predict their fate under future climate projections. Physiological approaches are limited in their ability to resolve the involved molecular mechanisms and attribute stress effects to the host or symbiont, while probing and partitioning of proteins cannot be applied in organisms where the host and symbiont are small and cannot be physically separated. Here we apply a label-free quantitative proteomics approach to detect changes of proteome composition in the diatom-bearing benthic foraminifera Amphistegina gibbosa experimentally exposed to three thermal-stress scenarios. We developed a workflow for protein extraction from less than ten specimens and simultaneously analysed host and symbiont proteomes. Despite little genomic data for the host, 1,618 proteins could be partially assembled and assigned. The proteomes revealed identical pattern of stress response among stress scenarios as that indicated by physiological measurements, but allowed identification of compartment-specific stress reactions. In the symbiont, stress-response and proteolysis-related proteins were up regulated while photosynthesis-related proteins declined. In contrast, host homeostasis was maintained through chaperone up-regulation associated with elevated proteosynthesis and proteolysis, and the host metabolism shifted to heterotrophy.

Younger Dryas ice margin retreat triggered by ocean surface warming in central-eastern Baffin Bay

The transition from the last ice age to the present-day interglacial was interrupted by the Younger Dryas (YD) cold period. While many studies exist on this climate event, only few include high-resolution marine records that span the YD. In order to better understand the interactions between ocean, atmosphere and ice sheet stability during the YD, more high-resolution proxy records from the Arctic, located proximal to ice sheet outlet glaciers, are required. Here we present the first diatom-based high-resolution quantitative reconstruction of sea surface conditions from central-eastern Baffin Bay, covering the period 14.0-10.2 kyr BP. Our record reveals warmer sea surface conditions and strong interactions between the ocean and the West Greenland ice margin during the YD. These warmer conditions were caused by increased Atlantic-sourced water inflow combined with amplified seasonality. Our results emphasize the importance of the ocean for ice sheet stability under the current changing climate.

Geochemical signatures of benthic foraminiferal shells from a heat-polluted shallow marine environment provide field evidence for growth and calcification under extreme warmth

Shallow marine calcifiers play an important role as marine ecosystem engineers and in the global carbon cycle. Understanding their response to warming is essential to evaluate the fate of marine ecosystems under global change scenarios. A rare opportunity to test the effect of warming acting on natural ecosystems is by investigation of heat-polluted areas. Here, we study growth and calcification in benthic foraminifera that inhabit a thermally polluted coastal area in Israel, where they are exposed to elevated temperatures reaching up to ~42°C in summer. Live specimens of two known heat-tolerant species Lachlanella sp. 1 and Pararotalia calcariformata were collected over a period of 1 year from two stations, representing thermally polluted and undisturbed (control) shallow hard bottom habitats. Single-chamber element ratios of these specimens were obtained using laser ablation, and the Mg/Ca of the most recently grown final chambers were used to calculate their calcification temperatures. Our results provide the first direct field evidence that these foraminifera species not only persist at extreme warm temperatures but continue to calcify and grow. Species-specific Mg/Ca thermometry indicates that P. calcariformata precipitate their shells at temperatures as high as 40°C and Lachlanella sp. 1 at least up to 36°C, but both species show a threshold for calcification at cold temperatures: calcification in P. calcariformata only occurred above 22°C and in Lachlanella sp. 1 above 15°C. Our observations from the heat-polluted area indicate that under future warming scenarios, calcification in heat-tolerant foraminifera species will not be inhibited during summer, but instead the temperature window for their calcification will be expanded throughout much of the year. The observed inhibition of calcification at low temperatures indicates that the role of heat-tolerant foraminifera in carbonate production will most likely increase in future decades.

ForCenS, a curated database of planktonic foraminifera census counts in marine surface sediment samples

Census counts of marine microfossils in surface sediments represent an invaluable resource for paleoceanography and for the investigation of macroecological processes. A prerequisite for such applications is the provision of data syntheses for individual microfossil groups. Specific to such syntheses is the necessity of taxonomical harmonisation across the constituent datasets, coupled with dereplication of previous compilations. Both of these aspects require expert knowledge, but with increasing number of records involved in such syntheses, the application of expert knowledge via manual curation is not feasible. Here we present a synthesis of planktonic foraminifera census counts in surface sediment samples, which is taxonomically harmonised, dereplicated and treated for numerical and other inconsistencies. The data treatment is implemented as an objective and largely automated pipeline, allowing us to reduce the initial 6,984 records to 4,205 counts from unique sites and informative technical or true replicates. We provide the final product and document the procedure, which can be easily adopted for other microfossil data syntheses.

Reef calcifiers are adapted to episodic heat stress but vulnerable to sustained warming

Shallow marine ecosystems naturally experience fluctuating physicochemical conditions across spatial and temporal scales. Widespread coral-bleaching events, induced by prolonged heat stress, highlight the importance of how the duration and frequency of thermal stress influence the adaptive physiology of photosymbiotic calcifiers. Large benthic foraminifera harboring algal endosymbionts are major tropical carbonate producers and bioindicators of ecosystem health. Like corals, they are sensitive to thermal stress and bleach at temperatures temporarily occurring in their natural habitat and projected to happen more frequently. However, their thermal tolerance has been studied so far only by chronic exposure, so how they respond under more realistic episodic heat-event scenarios remains unknown. Here, we determined the physiological responses of Amphistegina gibbosa, an abundant western Atlantic foraminifera, to four different treatments––control, single, episodic, and chronic exposure to the same thermal stress (32°C)––in controlled laboratory cultures. Exposure to chronic thermal stress reduced motility and growth, while antioxidant capacity was elevated, and photosymbiont variables (coloration, oxygen-production rates, chlorophyll a concentration) indicated extensive bleaching. In contrast, single- and episodic-stress treatments were associated with higher motility and growth, while photosymbiont variables remained stable. The effects of single and episodic heat events were similar, except for the presumable occurrence of reproduction, which seemed to be suppressed by both episodic and chronic stress. The otherwise different responses between treatments with thermal fluctuations and chronic stress indicate adaptation to thermal peaks, but not to chronic exposure expected to ensue when baseline temperatures are elevated by climate change. This firstly implies that marine habitats with a history of fluctuating thermal stress potentially support resilient physiological mechanisms among photosymbiotic organisms. Secondly, there seem to be temporal constraints related to heat events among coral reef environments and reinforces the importance of temporal fluctuations in stress exposure in global-change studies and projections.

Coupling of equatorial Atlantic surface stratification to glacial shifts in the tropical rainbelt

The modern state of the Atlantic meridional overturning circulation promotes a northerly maximum of tropical rainfall associated with the Intertropical Convergence Zone (ITCZ). For continental regions, abrupt millennial–scale meridional shifts of this rainbelt are well documented, but the behavior of its oceanic counterpart is unclear due the lack of a robust proxy and high temporal resolution records. Here we show that the Atlantic ITCZ leaves a distinct signature in planktonic foraminifera assemblages. We applied this proxy to investigate the history of the Atlantic ITCZ for the last 30,000 years based on two high temporal resolution records from the western Atlantic Ocean. Our reconstruction indicates that the shallowest mixed layer associated with the Atlantic ITCZ unambiguously shifted meridionally in response to changes in the strength of the Atlantic meridional overturning with a southward displacement during Heinrich Stadials 2–1 and the Younger Dryas. We conclude that the Atlantic ITCZ was located at ca. 1°S (ca. 5° to the south of its modern annual mean position) during Heinrich Stadial 1. This supports a previous hypothesis, which postulates a southern hemisphere position of the oceanic ITCZ during climatic states with substantially reduced or absent cross-equatorial oceanic meridional heat transport.

Selective responses of benthic foraminifera to thermal pollution

Persistent thermohaline pollution at a site along the northern coast of Israel, due to power and desalination plants, is used as a natural laboratory to evaluate the effects of rising temperature and salinity levels on benthic foraminifera living in shallow hard-bottom habitats. Biomonitoring of the disturbed area and a control station shows that elevated temperature is a more significant stressor compared to salinity, thus causing a decrease in abundance and richness. Critical temperature thresholds were observed at 30 and 35°C, the latter representing the most thermally tolerant species in the studied area Pararotalia calcariformata, which is the only symbiont-bearing species observed within the core of the heated area. Common species of the shallow hard-bottom habitats including several Lessepsian invaders are almost absent in the most exposed site indicating that excess warming will likely impede the survival of these species that currently benefit from the ongoing warming of the Eastern Mediterranean.

Nomenclature for the Nameless: A Proposal for an Integrative Molecular Taxonomy of Cryptic Diversity Exemplified by Planktonic Foraminifera

Investigations of biodiversity, biogeography, and ecological processes rely on the identification of "species" as biologically significant, natural units of evolution. In this context, morphotaxonomy only provides an adequate level of resolution if reproductive isolation matches morphological divergence. In many groups of organisms, morphologically defined species often disguise considerable genetic diversity, which may be indicative of the existence of cryptic species. The diversity hidden by morphological species can be disentangled through genetic surveys, which also provide access to data on the ecological distribution of genetically circumscribed units. These units can be identified by unique DNA sequence motifs and allow studies of evolutionary and ecological processes at different levels of divergence. However, the nomenclature of genetically circumscribed units within morphological species is not regulated and lacks stability. This represents a major obstacle to efforts to synthesize and communicate data on genetic diversity for multiple stakeholders. We have been confronted with such an obstacle in our work on planktonic foraminifera, where the stakeholder community is particularly diverse, involving geochemists, paleoceanographers, paleontologists, and biologists, and the lack of stable nomenclature beyond the level of formal morphospecies prevents effective transfer of knowledge. To circumvent this problem, we have designed a stable, reproducible, and flexible nomenclature system for genetically circumscribed units, analogous to the principles of a formal nomenclature system. Our system is based on the definition of unique DNA sequence motifs collocated within an individual, their typification (in analogy with holotypes), utilization of their hierarchical phylogenetic structure to define levels of divergence below that of the morphospecies, and a set of nomenclature rules assuring stability. The resulting molecular operational taxonomic units remain outside the domain of current nomenclature codes, but are linked to formal morphospecies as regulated by the codes. Subsequently, we show how this system can be applied to classify genetically defined units using the SSU rDNA marker in planktonic foraminifera and we highlight its potential use for other groups of organisms where similarly high levels of connectivity between molecular and formal taxonomies can be achieved.

Atherogenic versus non-atherogenic lipoprotein profiles in healthy individuals. is there a need to change our approach to diagnosing dyslipidemia?

The electrophoretic separation of lipoproteins on polyacrylamide gels enables the quantification of nonatherogenic and atherogenic plasma lipoproteins including small dense low density lipoprotein (sdLDL) particles, which represent the atherogenic lipoprotein subpopulations in plasma. This methodology could help distinguish between nonatherogenic hyperlipidemia, normolipidemia with an atherogenic lipoprotein profile, non-atherogenic normolipidemia, and atherogenic hyperlipidemia. According to our pilot research of a normolipidemic population, the atherogenic lipoprotein profile might be present in about 6% of normolipidemic young healthy individuals. Therefore, if confirmed by other studies, it will be necessary to consider a different diagnostic approach and risk stratification for patients with atherogenic normolipidemia (as well as non-atherogenic hypercholesterolemia).

Recent Invasion of the Symbiont-Bearing Foraminifera Pararotalia into the Eastern Mediterranean Facilitated by the Ongoing Warming Trend

The eastern Mediterranean is a hotspot of biological invasions. Numerous species of Indo-pacific origin have colonized the Mediterranean in recent times, including tropical symbiont-bearing foraminifera. Among these is the species Pararotalia calcariformata. Unlike other invasive foraminifera, this species was discovered only two decades ago and is restricted to the eastern Mediterranean coast. Combining ecological, genetic and physiological observations, we attempt to explain the recent invasion of this species in the Mediterranean Sea. Using morphological and genetic data, we confirm the species attribution to P. calcariformata McCulloch 1977 and identify its symbionts as a consortium of diatom species dominated by Minutocellus polymorphus. We document photosynthetic activity of its endosymbionts using Pulse Amplitude Modulated Fluorometry and test the effects of elevated temperatures on growth rates of asexual offspring. The culturing of asexual offspring for 120 days shows a 30-day period of rapid growth followed by a period of slower growth. A subsequent 48-day temperature sensitivity experiment indicates a similar developmental pathway and high growth rate at 28°C, whereas an almost complete inhibition of growth was observed at 20°C and 35°C. This indicates that the offspring of this species may have lower tolerance to cold temperatures than what would be expected for species native to the Mediterranean. We expand this hypothesis by applying a Species Distribution Model (SDM) based on modern occurrences in the Mediterranean using three environmental variables: irradiance, turbidity and yearly minimum temperature. The model reproduces the observed restricted distribution and indicates that the range of the species will drastically expand westwards under future global change scenarios. We conclude that P. calcariformata established a population in the Levant because of the recent warming in the region. In line with observations from other groups of organisms, our results indicate that continued warming of the eastern Mediterranean will facilitate the invasion of more tropical marine taxa into the Mediterranean, disturbing local biodiversity and ecosystem structure.

Fossil and genetic evidence for the polyphyletic nature of the planktonic foraminifera "Globigerinoides", and description of the new genus Trilobatus

Planktonic foraminifera are one of the most abundant and diverse protists in the oceans. Their utility as paleo proxies requires rigorous taxonomy and comparison with living and genetically related counterparts. We merge genetic and fossil evidence of "Globigerinoides", characterized by supplementary apertures on spiral side, in a new approach to trace their "total evidence phylogeny" since their first appearance in the latest Paleogene. Combined fossil and molecular genetic data indicate that this genus, as traditionally understood, is polyphyletic. Both datasets indicate the existence of two distinct lineages that evolved independently. One group includes "Globigerinoides" trilobus and its descendants, the extant "Globigerinoides" sacculifer, Orbulina universa and Sphaeroidinella dehiscens. The second group includes the Globigerinoides ruber clade with the extant G. conglobatus and G. elongatus and ancestors. In molecular phylogenies, the trilobus group is not the sister taxon of the ruber group. The ruber group clusters consistently together with the modern Globoturborotalita rubescens as a sister taxon. The re-analysis of the fossil record indicates that the first "Globigerinoides" in the late Oligocene are ancestral to the trilobus group, whereas the ruber group first appeared at the base of the Miocene with representatives distinct from the trilobus group. Therefore, polyphyly of the genus "Globigerinoides" as currently defined can only be avoided either by broadening the genus concept to include G. rubescens and a large number of fossil species without supplementary apertures, or if the trilobus group is assigned to a separate genus. Since the former is not feasible due to the lack of a clear diagnosis for such a broad genus, we erect a new genus Trilobatus for the trilobus group (type species Globigerina triloba Reuss) and amend Globoturborotalita and Globigerinoides to clarify morphology and wall textures of these genera. In the new concept, Trilobatus n. gen. is paraphyletic and gave rise to the Praeorbulina/Orbulina and Sphaeroidinellopsis/Sphaeroidinella lineages.

Pancreatic islet autotransplantation after completion pancreatectomy for pancreatic fistula after hemipancreatoduodenectomy for carcinoma

OBJECTIVE

Pancreatic islet autotransplantation (IAT) has a potential to prevent brittle diabetes in patients after total pancreatectomy. Because of the fear of tumor spread, IAT has rarely been used in case of malignancy. We report our experience with patients who underwent hemipancreatoduodenectomy for carcinoma and later completion pancreatectomy for pancreatic fistula with islet autotransplantation at our institution.

METHODS

From August 2007 to December 2012, 5 patients underwent IAT after completion pancreatectomy for pancreatic fistula after hemipancreatoduodenectomy for carcinoma. Islets were isolated from the pancreatic tail with the use of digestion with collagenase. Nonpurified islet suspension was infused into the portal vein during surgery.

RESULTS

The median number of islets transplanted was 175,000 islet equivalents (range, 70,000-365,000). One patient died after surgery for reasons unrelated to IAT. Another 3 patients had stable diabetes with partial graft function (fasting C-peptide levels 0.23, 0.41, and 0.61 nmol/L and HbA1c 4.8%, 4.6%, and 6.9% at 24, 24 and 9 months after IAT, respectively). The 1st patient, with pancreatic head carcinoma, was alive 28 months after IAT with lymph node and liver recurrence since 18 months after IAT. The 2nd patient, with gall bladder and distal bile duct carcinoma, died 47 months after IAT with tumor recurrence. The 3rd patient, with ampullary carcinoma, died 12 months after IAT with local recurrence and solitary liver metastasis. The last patient had been off insulin 9 months after IAT without tumor recurrence (fasting C-peptide, 0.89 nmol/L; HbA1c, 4.2%).

CONCLUSIONS

Autotransplantation of pancreatic islets isolated from the residual pancreatic tissue in patients who previously underwent hemipancreatoduodenectomy for cancer may provide stable glucose control and thus improve quality of life. In this small series we did not observe early development of multiple liver metastases caused by islet suspension contamination with malignant cells. Oncologic outcome of the patients was not worse than what would be expected without IAT.

Phylogeography of the tropical planktonic foraminifera lineage globigerinella reveals isolation inconsistent with passive dispersal by ocean currents

Morphologically defined species of marine plankton often harbor a considerable level of cryptic diversity. Since many morphospecies show cosmopolitan distribution, an understanding of biogeographic and evolutionary processes at the level of genetic diversity requires global sampling. We use a database of 387 single-specimen sequences of the SSU rDNA of the planktonic foraminifera Globigerinella as a model to assess the biogeographic and phylogenetic distributions of cryptic diversity in marine microplankton on a global scale. Our data confirm the existence of multiple, well isolated genetic lineages. An analysis of their abundance and distribution indicates that our sampling is likely to approximate the actual total diversity. Unexpectedly, we observe an uneven allocation of cryptic diversity among the phylogenetic lineages. We show that this pattern is neither an artifact of sampling intensity nor a function of lineage age. Instead, we argue that it reflects an ongoing speciation process in one of the three major lineages. Surprisingly, four of the six genetic types in the hyperdiverse lineage are biogeographically restricted to the Indopacific. Their mutual co-occurrence and their hierarchical phylogenetic structure provide no evidence for an origin through sudden habitat fragmentation and their limitation to the Indopacific challenges the view of a global gene flow within the warm-water provinces. This phenomenon shows that passive dispersal is not sufficient to describe the distribution of plankton diversity. Rather, these organisms show differentiated distribution patterns shaped by species interactions and reflecting phylogenetic contingency with unique histories of diversification rates.

Ancient origin of the modern deep-sea fauna

The origin and possible antiquity of the spectacularly diverse modern deep-sea fauna has been debated since the beginning of deep-sea research in the mid-nineteenth century. Recent hypotheses, based on biogeographic patterns and molecular clock estimates, support a latest Mesozoic or early Cenozoic date for the origin of key groups of the present deep-sea fauna (echinoids, octopods). This relatively young age is consistent with hypotheses that argue for extensive extinction during Jurassic and Cretaceous Oceanic Anoxic Events (OAEs) and the mid-Cenozoic cooling of deep-water masses, implying repeated re-colonization by immigration of taxa from shallow-water habitats. Here we report on a well-preserved echinoderm assemblage from deep-sea (1000-1500 m paleodepth) sediments of the NE-Atlantic of Early Cretaceous age (114 Ma). The assemblage is strikingly similar to that of extant bathyal echinoderm communities in composition, including families and genera found exclusively in modern deep-sea habitats. A number of taxa found in the assemblage have no fossil record at shelf depths postdating the assemblage, which precludes the possibility of deep-sea recolonization from shallow habitats following episodic extinction at least for those groups. Our discovery provides the first key fossil evidence that a significant part of the modern deep-sea fauna is considerably older than previously assumed. As a consequence, most major paleoceanographic events had far less impact on the diversity of deep-sea faunas than has been implied. It also suggests that deep-sea biota are more resilient to extinction events than shallow-water forms, and that the unusual deep-sea environment, indeed, provides evolutionary stability which is very rarely punctuated on macroevolutionary time scales.

Vertical niche partitioning between cryptic sibling species of a cosmopolitan marine planktonic protist

A large portion of the surface-ocean biomass is represented by microscopic unicellular plankton. These organisms are functionally and morphologically diverse, but it remains unclear how their diversity is generated. Species of marine microplankton are widely distributed because of passive transport and lack of barriers in the ocean. How does speciation occur in a system with a seemingly unlimited dispersal potential? Recent studies using planktonic foraminifera as a model showed that even among the cryptic genetic diversity within morphological species, many genetic types are cosmopolitan, lending limited support for speciation by geographical isolation. Here we show that the current two-dimensional view on the biogeography and potential speciation mechanisms in the microplankton may be misleading. By depth-stratified sampling, we present evidence that sibling genetic types in a cosmopolitan species of marine microplankton, the planktonic foraminifer Hastigerina pelagica, are consistently separated by depth throughout their global range. Such strong separation between genetically closely related and morphologically inseparable genetic types indicates that niche partitioning in marine heterotrophic microplankton can be maintained in the vertical dimension on a global scale. These observations indicate that speciation along depth (depth-parapatric speciation) can occur in vertically structured microplankton populations, facilitating diversification without the need for spatial isolation.

[Liver transplantation in patients with portal vein thrombosis]

AIM

The aim of the study was to perform a retrospective assessment in a group of patients with portal vein thromboses who underwent consecutive liver transplantation.

MATERIAL AND METHODS

PVT was preoperatively diagnosed with ultrasound and CT portography. The follow up period was 1 to 6 years. Postoperative immunosuppressive medication was administered in combination with cyclosporin A, prednison and imuran upon initiation of the transplantation programme (8 patients). During the follow up period, the treatment protocol was replaced with FK 506, Cell Cept and prednisone. Liver biopsy was indicated when rejection was suspected.

RESULTS

During 1996-2009, the team of authors performed a total of 740 liver transplantations in 303 female and 437 male subjects. The procedures included 703 primary procedures, 33 retransplantations and four second retransplantations. Out of the total, 57 recipients (7.7%) had portal vein obliteration. These subjects included 42 male and 15 females, their mean age was 52 (9-67) years. 62 liver transplantations were performed in these 57 patients. The following complications were recorded in the patient group: graft dysfunction in 10.5%, revisions for bleeding in 28%, hepatic artery thrombosis in 10.5%, portal vein rethrombosis in 1.8%, biliary complications in 17.5%, acute rejections in 19.3%. Perioperative mortality rate was 15.8%.The mean blood derivates requirement was 17.1 (0-425) erythrocyte transfusion units, 27.1 (0-132) frozen plasma transfusion units and 2.6 (0-20) thrombocyte transfusion units.

CONCLUSION

The results of out retrospective study indicate that portal thrombosis is not a contraindication for liver transplantation. Current surgical techniques make liver transplantations in patients with complete splanchnic venous thrombosis possible.

[Early biliary complications following liver transplantation]

INTRODUCTION

Biliary complications (BC) after liver transplantation (LTx) are serious problems with an incidence rate of 6-35%. There are two types of BC, early and late. Early BC is observed for 30 days post LTx or during the entire period of the patient's first hospital stay after LTx. The main causes of early BC are ischemia of the biliary tree (the bile duct of the transplanted liver is supplied only from the right hepatic artery descendingly; the supply from the gastroduodenal artery is lacking) as well as implementation of the biliary anastomosis surgical technique. Treatment of BC is administered by a surgeon, a gastroenterologist and a radiologist.

AIM

To evaluate early biliary complications after LTx

PATIENTS AND METHODS

We reviewed patients with early BC after LTx from 4/2004 - 12/2009. We defined early BC as a complication that is present during the first 30 days post LTx or during the entire period of the patient's first hospital stay after LTx.

RESULTS

We performed 384 LTx during the above-mentioned period. We carried out reconstruction of the biliary tree in the form of a choledochocholedochostomy (CDD) in 312 cases and in the form of a choledochojejunostomy (CDJ) in 72 cases. Sixty-eight patients had early BC (17.7%), 25 patients experienced biliary leak (6.5%), 40 patients had anastomotic stenosis (10.4%) and 3 patients (0.8%) experienced both complications (biliary leak and stenosis). Most complications were eliminated by ERCP with a papilosfincterotomy, a balloon dilatation of stenosis, and a biliary stent implant with repeated stent replacements (45 cases in total- all patients with biliary stenosis). Twenty-two patients were reoperated on (16x CDJ, 3x re-CDD, 2x suture of aberrant bile duct, 1x suture common bile duct) and 1 patient was treated by percutaneous transhepatic bilary drainage (PTD). The mortality rate was zero.

CONCLUSION

BC after LTx continue to pose a serious surgical problem. The treatment of choice when dealing with BC is ERCP, which has more than a 70% success rate. If ERCP or PTD are not successful, or when biliary peritonitis is present, we perform a reanastomosis of the bile duct. The combined effort of the surgeon, gastroenterologist and radiologist is the most important factor for successful treatment. The incidence of BC after LTx at IKEM is similar to that of treatment centers all over the world.

Contribution of the atherogenic lipoprotein profile to the development of arterial hypertension

OBJECTIVES

Determination of non-atherogenic and atherogenic plasma lipoproteins, including small dense LDL, in patients with newly diagnosed arterial hypertension and identification of the phenotype of lipoprotein profile: non-atherogenic phenotype A vs. atherogenic lipoprotein phenotype B, in plasma of examined subjects.

BACKGROUND

Atherogenic lipoproteins play an important role in the pathogenesis of arterial hypertension. Impaired lipoprotein metabolism results in overproduction of triglyceride-rich particles and LDL 3-7 subfractions - small dense LDL - a strongly atherogenic LDL subpopulation accelerating the development of arterial hypertension.

METHODS

Total cholesterol and triglycerides were analyzed by enzymatic CHOD-PAP method, Roche Diagnostics, Germany. Lipoprotein profiles of plasma described as atherogenic lipoprotein phenotype B or a nonaterogenic lipoprotein phenotype A were examined by a new method of lipoprotein separation by means of electrophoresis on polyacrylamide gel (Lipoprint LDL system). Prostacyclin and thromboxane A2 in plasma were analysed by ELISA method. Score of Atherogenic Risk was determined as a ratio of atherogenic and non-atherogenic plasma lipoproteins.

RESULTS

1) High percentage of atherogenic hypertriacylglycerolemia (93%) and atherogenic mixed hyperlipemia (86 %) in subjects with arterial hypertension. 2) Low percentage of atherogenic hypercholesterolemia (52 %) in subjects with arterial hypertension. 3) Atherogenic normolipemia (7%) in control group of healthy subject.

CONCLUSION

Contribution of this method lies in benefits as follows: A) Quantification of non-atherogenic and atherogenic plasma lipoproteins. B) Identification of high percentage of atherogenic dyslipoproteinemia (86-93%) in subjects with arterial hypertension. C) Presence of small dense LDL in plasma is decisive for declaring the atherogenic lipoprotein profile in both hyperlipemia and normolipemia (Tab. 5, Ref. 24).