Society of pediatric liver transplantation: Current registry status 2011-2018

BACKGROUND

SPLIT was founded in 1995 in order to collect comprehensive prospective data on pediatric liver transplantation, including waiting list data, transplant, and early and late outcomes. Since 2011, data collection of the current registry has been refined to focus on prospective data and outcomes only after transplant to serve as a foundation for the future development of targeted clinical studies.

OBJECTIVE

To report the outcomes of the SPLIT registry from 2011 to 2018.

METHODS

This is a multicenter, cross-sectional analysis characterizing patients transplanted and enrolled in the SPLIT registry between 2011 and 2018. All patients, <18 years of age, received a first liver-only, a combined liver-kidney, or a combined liver-pancreas transplant during this study period.

RESULTS

A total of 1911 recipients from 39 participating centers in North America were registered. Indications included biliary atresia (38.5%), metabolic disease (19.1%), tumors (11.7%), and fulminant liver failure (11.5%). Greater than 50% of recipients were transplanted as either Status 1A/1B or with a MELD/PELD exception score. Incompatible transplants were performed in 4.1%. Kaplan-Meier estimates of 1-year patient and graft survival were 97.3% and 96.6%. First 30 days of surgical complications included reoperation (31.7%), hepatic artery thrombosis (6.3%), and portal vein thrombosis (3.2%). In the first 90 days, biliary tract complications were reported in 13.6%. Acute cellular rejection during first year was 34.7%. At 1 and 2 years of follow-up, 39.2% and 50.6% had normal liver tests on monotherapy (tacrolimus or sirolimus). Further surgical, survival, allograft function, and complications are detailed.

Isozyme Variation among 40 Frankia Strains

Forty Frankia strains belonging to the Alnus and Elaeagnus host specificity groups and isolated from various plant species from different geographical areas were characterized by the electrophoretic separation of isozymes of eight enzymes. All the enzyme systems that were investigated showed large variation. Diaphorases and esterases gave multiple band patterns and confirmed the identification of specific Frankia strains. Less variability was observed with enzymes such as phosphoglucose isomerase, leucine aminopeptidase, and malate dehydrogenase, which allowed for the delineation of larger groups of Frankia strains. Cluster analysis, based on the pair-wise similarity coefficients calculated between strains, delineated three large, dissimilar groups of Frankia strains, although each of these groups contained a large amount of heterogeneity. However, numerous Frankia strains, mainly from the Alnus host specificity group, demonstrated a perfect homology for all the enzymes tested.

Comparative analysis of nutrition data from national, household, and individual levels: results from a WHO-CINDI collaborative project in Canada, Finland, Poland, and Spain

STUDY OBJECTIVE

This project determined to what extent data on diet and nutrition, which were collected in a non-uniform manner, could be harmonised and pooled for international and national comparison.

DESIGN

Direct comparisons of dietary data between studies were made using food balance sheets (FBS), household budget surveys (HBS), and individual dietary data (IDS); comparisons were also made within countries. Differences in study design and methodological approaches were taken into consideration. Data from research projects from the following four World Health Organisation (WHO) Countrywide Integrated Noncommunicable Disease Intervention (CINDI) countries were included-Canada, Finland, Poland, and Spain.

MAIN RESULTS

FBS overestimated food consumption and nutrient intake compared to IDS. Results between HBS and IDS were quite similar, except for fish, meat, pulses and vegetables, which were underestimated by HBS, and sugar and honey and cereals, which were overestimated. Percentages of energy from fat, carbohydrates and proteins were higher when estimated from FBS, HBS, and IDS respectively.

CONCLUSIONS

Results suggest that estimations from these three sources of dietary data are difficult to compare because they are measuring different levels of dietary information. The understanding of their relations may be important in formulating and evaluating a nutrition policy.

Modulation of L-type Ca2+ channels in UMR 106 cells by parathyroid hormone-related protein

The effects of rat parathyroid hormone-related protein (rPTHrP) and bovine and rat parathyroid hormone (bPTH and rPTH) on L-type Ca2+ channels in UMR 106 cells were investigated using the patch clamp technique. rPTHrP increased the whole cell L-type Ca2+ channel currents and the increase was concentration dependent. rPTHrP, at a concentration of 62.5 nM, increased the L-type Ca2+ channel current by 122+/-25%. bPTH was less potent. A concentration of 7.5 microM bPTH increased the current by 99+/-24%. Results obtained with rPTH were similar to those obtained using bPTH. Single channel measurements, using the cell-attached version of the patch clamp technique, showed an increase in both the number of channel openings and the mean open time when the cells were exposed to rPTHrP. This suggested that rPTHrP affected the gating of L-type Ca2+ channels in UMR 106 cells. This study demonstrates that the actions of bPTH and rPTHrP in UMR cells are mediated in part by extracellular Ca2+ entry. PTHrP, a paracrine agent important in development, is more potent in regulating Ca2+ entry than PTH.

Fast and robust optic disc detection using pyramidal decomposition and Hausdorff-based template matching

We report about the design and test of an image processing algorithm for the localization of the optic disk (OD) in low-resolution (about 20 micro/pixel) color fundus images. The design relies on the combination of two procedures: 1) a Hausdorff-based template matching technique on edge map, guided by 2) a pyramidal decomposition for large scale object tracking. The two approaches are tested against a database of 40 images of various visual quality and retinal pigmentation, as well as of normal and small pupils. An average error of 7% on OD center positioning is reached with no false detection. In addition, a confidence level is associated to the final detection that indicates the "level of difficulty" the detector has to identify the OD position and shape.

Identification of endomycorrhizal fungi colonizing roots by fluorescent single-strand conformation polymorphism-polymerase chain reaction

A method to identify arbuscular endomycorrhizal fungi based on the amplification of portions of the nuclear gene coding for the small subunit rRNA is presented. By coupling the sensitivity of the polymerase chain reaction and the specificity afforded by taxon-specific primers, a variety of samples can be analyzed, including small amounts of colonized roots. Family-specific primers as well as generic primers are described and can be used to amplify small subunit rRNA fragments from endomycorrhizal fungi by polymerase chain reaction. The amplified products are then subjected to single-strand conformation polymorphism analysis to detect sequence differences. Among the advantages of this approach is the possibility of directly identifying the fungi inside field-collected roots, without having to rely on the fortuitous presence of spores. This technique should have obvious applications in the study of arbuscular endomycorrhizal fungi populations and allow closer examination of their host specificity.

Rapid quantitation by PCR of endomycorrhizal fungi colonizing roots

The VANS1/NS21 primer pair is useful for specifically amplifying a 550-bp ribosomal (r) DNA fragment from arbuscular endomycorrhizal fungi, directly from colonized root extracts. A procedure to quantitate these obligatory biotrophs rapidly, based on competitive PCR, was developed by constructing a suitable internal standard to be used with these primers. A 130-bp deletion in the Glomus mossae VANS1/NS21 amplified rDNA fragment was produced by amplifying separately external portions of that fragment, followed by ligation and amplification using the original external primers. When this deleted fragment was added to G. mossae rDNA, amplification using VANS1/NS21 primers yielded the two expected products of 430 bp and 550 bp, respectively, resolved by agarose electrophoresis. This fragment was cloned into the pCL1920 plasmid, a low-copy-number vector (five copies per cell), and mixed with the roots to be analyzed. This provides for a rapid quantitative assay because both steps--extraction of DNA from colonized roots and PCR amplification--are taken into account by the same internal standard. Using this procedure, a sample of colonized leek roots (Allium porum x Glomus vesiculiferum) was shown to contain 5 x 10(4) copies of arbuscular endomycorrhizal fungi rDNA genes per milligram of fresh weight.

Effect of ABA on freezing resistance of Betula papyrifera and Alnus incana woody plant cell suspensions

Treatment of birch (Betula papyrifera Marsh) and alder (Alnus incana (L.) Moench) cell suspension cultures with ABA increased the freezing resistance of the cells. After 7 days of treatment with 10(-5) M ABA, birch cells grown at 23 and 4 degrees C attained an LT(50) of -16.9 and -14.1 degrees C, respectively, whereas control cells had an LT(50) of -9.1 degrees C. In alder cell suspensions, treatment with 10(-5) M ABA at 23 degrees C induced a small increase in freezing resistance from -7.3 to -10.8 degrees C. Exposure to 4 degrees C alone did not induce a significant increase in hardiness in birch cell suspensions. Addition of 10(-5) M ABA to the medium inhibited fresh weight increase over 10 days of 3-g inocula of birch and alder by 70 and 52%, respectively. With the same concentration of ABA in the medium we found different intracellular ABA concentrations in 3- and 6-g inocula. We conclude that the concentration of ABA in the medium does not reflect the intracellular concentration of tissue cultures, and that cultural conditions may influence ABA accumulation by cell cultures.

Specific amplification of 18S fungal ribosomal genes from vesicular-arbuscular endomycorrhizal fungi colonizing roots

The first DNA sequences obtained from arbuscular endomycorrhizal fungi are reported. They were obtained by directly sequencing overlapping amplified fragments of the nuclear genes coding for the small subunit rRNA. These sequences were used to develop a polymerase chain reaction primer (VANS1) that enables the specific amplification of a portion of the vesicular-arbuscular endomycorrhizal fungus small subunit rRNA directly from a mixture of plant and fungal tissues. The specificity of this primer for arbuscular endomycorrhizal fungi was demonstrated by testing it on a number of organisms and by sequencing the fragment amplified from colonized leek (Allium porum) roots. This approach, coupled with other molecular techniques, will facilitate rapid detection, identification, and possibly quantitation of arbuscular endomycorrhizal fungi.

Gene transfer by electroporation in betulaceae protoplasts: Alnus incana

The Escherichia coli β-glucuronidase gene (GUS) was introduced into Alnus incana (L.) Moench protoplasts by electroporation. Level of GUS transient gene expression was increased by increasing DNA concentrations of pBI 221 plasmid and was affected by the amplitude and duration of the applied electric pulse as well as by the presence of polyethylene glycol (PEG) in the electroporation medium. An optimal level of GUS activity was obtained after electroporation with a capacitive discharge of 500 V/cm and 71 ms-duration. This transformation procedure is simple and efficient. These results motivated us to investigate this method as a possible way of achieving the stable transformation of actinorhizal alder.

Genetic transformation of 9 in vitro clones of Alnus and Betula by Agrobacterium tumefaciens

Crown gall tumorigenesis, integration and expression of T-DNA encoded genes from Agrobacterium tumefaciens were investigated in 9 clones of Alnus glutinosa, A. incana and Betula papyrifera. Tumor formation on in vitro shoots was frequent in all clones with strain Ach5 and present in 8 clones with strain C58. Tumors excised from shoots were selected for autotrophic growth in vitro and axenic cultures were established. Octopine or nopaline, respective of the strain type used for inoculation, was detected in tumorous cultures. Southern blot analyses demonstrated T-DNA integration by hybridization of DNA from tumors with tmr and nos gene probes. One clone of B. papyrifera produced tumors with a morphogenic character, unusual in calli of this species, generating viable shoots which did not synthesize opine.

Separation of various Frankia strains in the Alnus and Elaeagnus host specificity groups using sugar analysis

To confirm the role of glycosides in the taxonomy of Frankia, 79 strains initially isolated from Alnus spp., Myrica spp., Comptonia sp., Elaeagnus spp., Shepherdia spp., and Hippophaë sp. host plants were tested for relative sugar content after 2 and 8 weeks of growth. Gas chromatography was used to separate the trimethylsilyl derivatives of sugars present in whole-cell hydrolysates of the Frankia strains; six sugars were quantitatively analyzed including 2-O-methyl-D-mannose, a sugar ubiquitous in the genus Frankia. The separation of the Frankia strains into their appropriate host specificity group (Alnus or Elaeagnus), based only on the sugar content, was achieved using statistical analyses of observations at 2 and 8 weeks. All statistical analyses correlated together and showed a significant separation between both host specificity groups. 2-O-Methyl-D-mannose, the concentration of which varied greatly between the Alnus and Elaeagnus host specificity groups, was the most discriminant sugar. Moreover, it was constant at both ages. From discriminant analysis, the separation of the various Frankia strains tested into their respective host specificity group was more precise at 2 weeks with a classification success of 97%, as compared with 78% at 8 weeks. The Myrica gale isolates that nodulated host plants from both host specificity groups were generally intermediate in their sugar content between the Alnus and Elaeagnus host specificity groups.

Allozyme variability in natural populations of green alder (Alnus crispa) in Quebec

Vegetative and sexual tissues from 22 populations of Alnus crispa (Ait.) Pursh (green alder, Betulaceae) in Quebec were analyzed for electrophoretically demonstrable diversity of 11 enzymes encoded by 16 structural loci in sexually mature populations. Of these 16 loci, 9 were found polymorphic. A total of 28 different alleles were detected with no more than three alleles per locus. No two-locus linkage disequilibrium was observed between eight polymorphic loci analyzed. Assuming a diploid model, average level of expected heterozygosity was 0.14 in the mature generation, with nearly all populations in Hardy–Weinberg equilibrium for the set of polymorphic loci investigated. Mean outcrossing rate was 0.95. Fixation indices revealed low inbreeding with no specific subpopulation structure. Hence, an important level of gene flow would exist within the populations. Without any strong evidence for polyploidy, and in the light of results obtained, the species could be classified equally well as a diploid or a diploidized allotetraploid.

Key words: actinorhizal plant, alder, allozymes, Alnus, fixation indices, heterozygosity, outcrossing rate, polyploidy.

Cloning of a multicopy plasmid from the actinorhizad nitrogen-fixing bacterium Frankia sp. and determination of its restriction map

An 8.3-kb multicopy plasmid, pFQ31, from the nitrogen-fixing Frankia sp. strain ArI3, was cloned into Escherichia coli plasmid vectors and analysed physically. pFQ31 has no detectable sequence homology with another Frankia plasmid, pFQ32, which is present in the same host. Derivatives of pFQ31 with an antibotic resistance marker were introduced into Streptomyces lividans, which is taxonomically related to Frankia, but no stable replication could be achieved.

Influence of phenolics on in vitro growth of Frankia strains

The influence of some common plant phenolics was tested on six Frankia strains isolated from both Alnus and Elaeagnus host plants. The addition of 1 mM of different phenolics to QmodB broth significantly influenced the growth and (or) the morphological development of Frankia. Ferulic, o-coumaric, and p-coumaric acids were extremely effective in inhibiting the growth of Frankia colonies, increasing the ramification of hyphae, and decreasing the number and size of sporangia produced in vitro. However, benzoic and p-hydroxybenzoic acids did not influence the total growth of Frankia colonies but stimulated the in vitro production of spherical septate vesicles on the two strains of Frankia type N tested. The possibility that these active phenolics, which are known to be present in Alnus actinorhizae, might act as "chemical mediators" between the host cell and its endophytic Frankia is suggested.

2-O-Methyl-D-mannose, a key sugar in the taxonomy of Frankia

The classification of actinomycetes in the genus Frankia Brunchorst has been based partly on morphology but primarily on their ability to form N2-fixing nodules on roots of actinorhizal host plants. To identify nonsporulating and noninfective Frankia isolates, biochemical tests are needed. Sugars present in whole-cell hydrolysates have proven useful in the taxonomy of other genera of actinomycetes. We, and others, have found a sugar in all Frankia isolates examined thus far that is absent in all other actinomycetes tested. After reduction with NaBD2H4 and acetylation, the characteristic sugar was found by gas chromatographic and mass spectrometric analyses to be a 2-O-methyl hexose. The sugar was partially purified by high pressure liquid chromatography and demethylated to give a major product of mannose. Authentic 2-O-methyl mannose as its alditol acetate and trimethylsilyl methyl glycoside derivatives cochromatographed with the sugar. By gas–liquid chromatography of its trimethylsilyl (−)-2-butyl glycoside, the marker sugar was found to be 2-O-methyl-D-mannose. The 2-O-methyl-D-mannose was present in all 68 strains of Frankia isolated from the actinorhizae of seven species of Alnus, two species of Elaeagnus, and one species each of Myrica, Comptonia, and Shepherdia. These actinorhizal host plants originated from different provenances in Canada, U.S.A., France, and Holland.

Plasmids in Frankia sp

A method to achieve cell lysis and isolate Frankia sp. plasmid DNA was developed. A screening of Frankia sp. strains belonging to different host compatibility groups (Alnus sp., Elaeagnus sp., Ceanothus sp.) showed that, of 39 strains tested, 4 (strains Cp11, ARgN22d, ArI3, and EUN1f) possessed plasmids ranging in size from 7.1 to 32.2 kilobase pairs as estimated from agarose gel electrophoresis and electron microscopy. A total of 11 plasmids were detected.

Evaluation of Frankia strains isolated from provenances of two Alnus species

Using the OsO4 isolation method, more than 200 Frankia strains were obtained from 27 provenances of the two alder species represented in Quebec, i.e., Alnus crispa (Ait.) Pursh. and Alnus rugosa (Du Roi) Spreng. The Frankia isolates were evaluated for morphological characteristics, infectivity, and efficiency. Variations in these factors were noted between provenances and also between isolates from a single provenance. The distribution of sporulating (Sp+) and nonsporulating (Sp−) type isolates was found to be related to host plants and provenance. The sporulating or nonsporulating endophytic character was found to significantly affect efficiency. This endophytic character was recognized as one of the valid criteria that should be used in the awaited species definition in the genus Frankia.

Role of lectins in plant--microorganism interactions. IV. Ultrastructural localization of soybean lectin binding sites of Rhizobium japonicum

The binding of purified, ferritin-labeled soybean seed lectin to the cell surfaces of Rhizobium japonicum 31 lb 138 has been examined by whole mount, thin section, and freeze-etch electron microscopy. The ferritin-labeled lectin binds in a biochemically specific manner to the capsular material of this bacterium. The lectin does not bind to the outer membranes of the cells or to flagella. Labeled lectin binds to sites throughout the capsular structure, although the density of labeling is somewhat greater on the outer surface of the capsule. Some cells appear to be partially encapsulated. Preservation of the capsular material proved difficult, and methods for retaining most of the capsular material were developed.

Ultrastructural and immunological demonstration of the nodulation of the European Alnus glutinosa (L.) Gaertn. host plant by the North-American Alnus crispa var. mollis Fern. root nodule endophyte

The inoculation of the European Alnus glutinosa (L.) Gaertn. host plant by a crushed-nodule inoculum, prepared with the North-American Alnus crispa var. mollis Fern. root nodule, was successful. Fluorescein- and ferritin-labelled antibodies, specific against the A. crispa var. mollis root nodule endophyte (Lalonde et al. 1975), demonstrated the idenity of this endophyte in the resulting nodules. The nodulation process of this abnormal host-endophyte system was studied by light and electron microscopy. An excretion of host blebs containing electron-dense polysaccharide material, resulting in the formation of exo-encapsulation threads containing presumptive endophytic bacterial cells, was associated with deformed root hairs. Originating from an exoencapsulation thread, the endophyte penetrates the root hair cell and then migrates as a hypha toward the cortical cells of the root. Its migration in the cortical cells of the primary nodule results in the induction of a lateral root which develops as the true nodule. The ultrastructure of the A. crispa var. mollis endophyte developing in the primary and true nodule of the abnormal A. glutinosa host was similar to the one induced inside its normal A. crispa var. mollis host. The actinomycetal intruder was a branched and septate hypha able to produce septate vesicles. The endophyte was always encapsulated in an electron-dense polysaccharide material surrounded by a host plasma membrane envelope. However, in this abnormal host-endophyte system, the number of primary nodules formed per root system was drastically reduced, and their appearance was delayed by 1 to 2 weeks. The delayed nodules were effective in fixing nitrogen and able to support satisfactory plant growth in a nitrogen-free medium.

The physician and health promotion

Images

Demonstration of the isolation of non-infective Alnus crispa var. mollis Fern, nodule endophyte by morphological immunolabelling and whole cell composition studies

Two filamentous, branched, and septate actinomycetes were isolated from field-collected and from axenic in vitro produced root nodules of Alnus crispa var. mollis Fern. host plant. After their transfer to a chemically defined medium, these nodule isolates could not be distinguished from each other on the basis of morphology, cultural reactions, and whole cell composition and were considered to be the same species. They were morphologically similar to the root nodule endophyte, but were incapable of nodulating aseptic host plants growing in a nitrogen-deficient substrate. Whole cells of the nodule isolates were used for the production of rabbit antibodies. The resulting specific antiisolate antibodies were conjugated with fluorescein isothiocyanate and used in staining tests of the nodule endophyte. The immunofluorescence reactions demonstrated the homology of the nodule isolates with the nodule endophyte. After pectinase degradation of the endophyte capsule, the indirect immunoferritin method corroborated the fluorescent anti-body (FA) staining reactions. There was no antigenic relationship between the nodule isolates and 13 known strains of actinomycetes as determined by the FA techique. Fluorescent antibody reactions of adsorbed conjugates suggested that endophytes of both Alnus crispa var. mollis Fern. and Alnus rugosa (DuRoi) Spreng. root nodules belong to a common serotype. The LL and mesoisomers of diaminopimelic acid were present in similar proportions in the nodule endophyte and in the nodule isolates. Glucose, mannose, and an unknown sugar were the predominant whole cell sugars in the nodule isolates, although trace amounts of arabinose and rhamnose were also displayed. The unknown sugar found in the nodule isolates was also present in trace amounts in the endophyte-suspension hydrolysate.

Ultrastructure of the Alnus crispa var. mollis Fern. root nodule endophyte

Nitrogen-fixing, field-obtained root nodules of the silky green alder were studied by transmission electron microscopy. The nodule endophyte exhibited a prokaryotic cytology and was present in two forms: the hypha(0.3-1.0mum), which was branched and septate, and the vesicle (3-5mum), which was also septate and developed at the parental hypha tip. Bacteria-like cells, previously observed in light microscopy studies, were not seen in the present work. The actinomycete-like endophyte penetrated through the host cell wall and becane enveloped by a capsular material (0.1mum), the whole being enclosed by host membranes. In some host cells, the endophyte appeared to lyse and become a mass of shrunken debris. The fine structure of the Alnus crispa var. mollis root nodule endophyte was found to be similar to that of other nonleguminous root nodule endophytes.