Liver transplantation in 100 children: Cambridge and King's College Hospital series.

To review the results of the Addenbrooke''s and King''s College Hospital children''s liver transplantation programme.Retrospective analysis of the first 100 children to receive liver grafts at Addenbrooke''s Hospital, Cambridge, from December 1983 to March 1990.Addenbrooke''s Hospital, Cambridge, and King''s College Hospital, London.153 children assessed for liver transplantation, of whom 22 died before a donor became available and 31 were considered unsuitable. 100 children received grafts, of whom 27 had second grafts.One year actuarial patient survival was 71%, with 57% one year graft survival. In the last two years survival rates had improved considerably, with 86% of patients and 63% of grafts surviving for at least one year. Sixty five children were alive 12 to 86 months after transplantation; 63 were well and leading normal active lives and 56 had entirely normal liver function. Children''s growth and development were essentially normal, with many showing remarkable catch up growth.Liver transplantation offers children with terminal liver disease a high chance of a return to full quality life and normal development. Improved surgical and medical care have progressively improved survival. The timing of transplantation is critical but has been constrained particularly by the availability of donors and resources.     

Ampicillin induced septum formation in Bacillus cereus

Cells of Bacillus cereus grown in the presence of subinhibitory concentrations of ampicillin at either 30 degrees or 45 degrees C exhibited an increase in the numbers of centres of septum formation per unit cell length. Under identical conditions of cultivation, cells of Escherichia coli grew as aseptate filaments. In general, untreated B. cereus cells grown at 45 degrees C were longer than those grown at 30 degrees C. The strain of E. coli used was unaffected in terms of filamentation by elevated growth temperature. Results are discussed in terms of the presence and availability of penicillin binding proteins and autolysins involved in cell growth, division and separation.     

Effect of neurotensin on pancreatic function in man

The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs.     

P2X<Subscript>7</Subscript>R modulation of visually evoked synaptic responses in the retina

P2X₇Rs are distributed throughout all layers of the retina, and thus, their localisation on various cell types puts into question their specific site(s) of action. Using a dark-adapted, ex vivo mouse retinal whole mount preparation, the present study aimed to characterise the effect of P2X₇R activation on light-evoked, excitatory RGC ON-field excitatory post-synaptic potentials (fEPSPs) and on outer retinal electroretinogram (ERG) responses under comparable conditions. The pharmacologically isolated NMDA receptor-mediated RGC ON-fEPSP was reduced in the presence of BzATP, an effect which was significantly attenuated by A438079 and other selective P2X₇R antagonists A804598 or AF27139. In physiological Krebs medium, BzATP induced a significant potentiation of the ERG a-wave, with a concomitant reduction in the b-wave and the power of the oscillatory potentials. Conversely, in the pharmacologically modified Mg²⁺-free perfusate, BzATP reduced both the a-wave and b-wave. The effects of BzATP on the ERG components were suppressed by A438079. A role for P2X₇R function in visual processing in both the inner and outer retina under physiological conditions remains controversial. The ON-fEPSP was significantly reduced in the presence of A804598 but not by A438079 or AF27139. Furthermore, A438079 did not have any effect on the ERG components in physiological Krebs but potentiated and reduced the a-wave and b-wave, respectively, when applied to the pharmacologically modified medium. Therefore, activation of P2X₇Rs affects the function in the retinal ON pathway. The presence of a high concentration of extracellular ATP would most likely contribute to the modulation of visual transmission in the retina in the pathophysiological microenvironment.     

Individual Dopaminergic Neurons of Lamprey SNc/VTA Project to Both the Striatum and Optic Tectum but Restrict Co-release of Glutamate to Striatum Only

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Characterization and the broad cross‐species applicability of 20 anonymous nuclear loci isolated from the Taiwan Hwamei (Garrulax taewanus)

We isolated 20 anonymous nuclear loci (8556 bp in total) from the Taiwan Hwamei (Garrulax taewanus), an endemic songbird of Taiwan. A panel of nine to 15 individuals with unknown relationship was used to characterize polymorphism of these loci. We identified 46 single nucleotide polymorphic sites (SNPs) in 15 polymorphic loci. Frequency of SNPs was one per every 186 bp in average. Nucleotide diversity, θ, ranged from 0.00054 to 0.00371 per locus. We also tested cross‐species applicability of these loci on 17 species from eight different passerine families. All 20 loci could be successfully amplified (ranged from one to 16 species, mean = 7.9 species).     

Soil carbonate drives local adaptation in Arabidopsis thaliana

High soil carbonate limits crop performance especially in semiarid or arid climates. To understand how plants adapt to such soils, we explored natural variation in tolerance to soil carbonate in small local populations (demes) of Arabidopsis thaliana growing on soils differing in carbonate content. Reciprocal field‐based transplants on soils with elevated carbonate (+C) and without carbonate (?C) over several years revealed that demes native to (+C) soils showed higher fitness than those native to (?C) soils when both were grown together on carbonate‐rich soil. This supports the role of soil carbonate as a driving factor for local adaptation. Analyses of contrasting demes revealed key mechanisms associated with these fitness differences. Under controlled conditions, plants from the tolerant deme A1_(+C) native to (+C) soil were more resistant to both elevated carbonate and iron deficiency than plants from the sensitive T6_(?C) deme native to (?C) soil. Resistance of A1_(+C) to elevated carbonate was associated with higher root extrusion of both protons and coumarin‐type phenolics. Tolerant A1_(+C) also had better Ca‐exclusion than sensitive T6_(?C). We conclude that Arabidopsis demes are locally adapted in their native habitat to soils with moderately elevated carbonate. This adaptation is associated with both enhanced iron acquisition and calcium exclusion.     

Arsenic hyperaccumulation in gametophytes of Pteris vittata. A new model system for analysis of arsenic hyperaccumulation

The sporophyte of the fern Pteris vittata is known to hyperaccumulate arsenic (As) in its fronds to >1% of its dry weight. Hyperaccumulation of As by plants has been identified as a valuable trait for the development of a practical phytoremediation processes for removal of this potentially toxic trace element from the environment. However, because the sporophyte of P. vittata is a slow growing perennial plant, with a large genome and no developed genetics tools, it is not ideal for investigations into the basic mechanisms underlying As hyperaccumulation in plants. However, like other homosporous ferns, P. vittata produces and releases abundant haploid spores from the parent sporophyte plant which upon germination develop as free-living, autotrophic haploid gametophyte consisting of a small (<1 mm) single-layered sheet of cells. Its small size, rapid growth rate, ease of culture, and haploid genome make the gametophyte a potentially ideal system for the application of both forward and reverse genetics for the study of As hyperaccumulation. Here we report that gametophytes of P. vittata hyperaccumulate As in a similar manner to that previously observed in the sporophyte. Gametophytes are able to grow normally in medium containing 20 mm arsenate and accumulate >2.5% of their dry weight as As. This contrasts with gametophytes of the related nonaccumulating fern Ceratopteris richardii, which die at even low (0.1 mm) As concentrations. Interestingly, gametophytes of the related As accumulator Pityrogramma calomelanos appear to tolerate and accumulate As to intermediate levels compared to P. vittata and C. richardii. Analysis of gametophyte populations from 40 different P. vittata sporophyte plants collected at different sites in Florida also revealed the existence of natural variability in As tolerance but not accumulation. Such observations should open the door to the application of new and powerful genetic tools for the dissection of the molecular mechanisms involved in As hyperaccumulation in P. vittata using gametophytes as an easily manipulated model system.