Recovery of an urbanised estuary: Clean-up, de-industrialisation and restoration of redundant dock-basins in the Mersey.

For much of the 20th century, the Mersey in North West England was one of the worst polluted estuaries in Europe. Water from a range of polluting industries plus domestic sewage was discharged into the Mersey Catchment and Estuary. Recovery came through a concerted clean-up campaign and tightening environmental regulations, partly driven by European Commission Directives, coupled with de-industrialisation from the 1970s onward. Recovery of oxygen levels in the Estuary led to the return of a productive ecosystem. This led to conservation designations, but also concerns about transfer of pollutants to higher trophic levels in fish, birds and humans. As part of urban renewal, ecosystems in disused dock basins were restored using mussel biofiltration and artificial de-stratification, facilitating commercial redevelopment and creation of a tourist destination. The degradation and recovery of the Mersey from peak-pollution in the mid-20th century is put in the context of wider environmental change and briefly compared to other systems to develop a hysteresis model of degradation and recovery, often to novel ecosystems.

A paediatric ECMO case of plasma leakage through a polymethylpentene oxygenator.

Polymethylpentene (PMP) oxygenators, utilised for ECMO, are commonly believed to be resistant to plasma leakage. Whilst uncommon, plasma leakage has been previously reported with PMP fibres, both in vivo and in vitro. We describe a paediatric ECMO case during which plasma leakage occurred and oxygenator function gradually deteriorated, ultimately necessitating device replacement. To our knowledge, this is the first case of plasma leakage described using a PMP device during paediatric ECMO. Subsequent investigation is described, demonstrating that a protein coating reduces the free passage of solution across the PMP membrane.

Insensible water loss from the Hilite 2400LT oxygenator: an in vitro study.

BACKGROUND: Neonatal extracorporeal membrane oxygenation (ECMO) patients are particularly vulnerable to the effects of uncompensated insensible water loss resulting in hypernatraemia. There exists a long-standing relationship between hypernatraemia and varying degrees of cerebral dysfunction. The aim of this study is to explore the degree to which free water loss occurs across a commonly used ECMO oxygenator, the polymethylpentene (PMP) membrane Hilite 2400LT (Medos, Medizintechnik AG, Stolberg, Germany). The secondary aim is to assess to what extent the addition of heat and/or humidity ameliorates this water loss. METHODS: An ECMO circuit consisting of a centrifugal pump and a Hilite 2400LT oxygenator was primed with crystalloid and albumin. Each experimental trial was carried out in triplicate, with gas flow rates of 1, 3 and 4.8 L/min being investigated. Fluid loss was assessed at six time points over a 24-hour period. RESULTS: Water loss increased significantly from 1 to 3 L/min gas flow (p=0.05) and from 3 to 4.8 L/min gas flow (p=0.025). The mean water loss differences between the differing gas flow trials per L/min gas flow were non-significant (72.4 ±3.9 ml/24 hrs). The effect of heating the gas to 37 °C did not significantly alter water loss, whereas heat and humidity reduced water loss significantly (p=0.009). CONCLUSIONS: Insensible water loss from a Hilite 2400LT oxygenator is approximately 72 ml/day per L/min gas flow over 24 hrs. Heating and humidifying the gas reduces the fluid loss significantly to approximately 8 ml/L/min gas flow over 24 hrs (p=0.009).

Further study of chromosome 7p22 to identify the molecular basis of familial hyperaldosteronism type II.

Familial hyperaldosteronism type II (FH-II) is an inherited form of hyperaldosteronism associated with hypertension in most patients. The mutations that cause FH-II are unknown, but linkage analysis has mapped them to chromosome 7p22. As FH-II is clinically indistinguishable from sporadic primary aldosteronism, a common and treatable condition, unravelling the cause of FH-II has important implications for these sporadic cases. To investigate whether FH-II is caused by large deletions or insertions, we examined the virtual karyotype of four pairs of affected and unaffected individuals using high-density bead chips. We also sequenced the coding regions of five 7p22 candidate genes that were prioritized because of their putative role in cell growth. We found no evidence of single-nucleotide polymorphism (SNP) copy number variation between pairs, and from the widest gap on the chip, chromosome 7p22 deletions or insertions exceeding ∼50 kb in these pedigrees can be excluded. We found 15 SNPs (two of which were novel), but none of them were non-synonymous and segregated with the disease in the FH-II pedigrees. We have been able to exclude large genomic deletions or insertions at 7p22 and refine the candidate gene list for this locus, but the mutations causing FH-II remain elusive.

The functional significance of genetic variation within the beta-adrenoceptor.

The beta-1 adrenoceptor is an archetypal G-coupled protein receptor that controls sympathetic responses in the heart, kidney and adipocytes. It has been widely exploited as a drug target with the development of antagonists to treat cardiovascular diseases such as hypertension, angina and heart failure. Signalling through the receptor is modulated by desensitization and beta1- adrenoceptor down-regulation. It is also affected by in vitro substitution of specific amino acid residues within the beta-1 adrenoceptor. Amino acid substitutions also occur naturally due to polymorphic variation within the human beta-1 adrenoceptor gene itself. Since these variants are common (typically being present in > 5% of the population), the pharmacogenetic implications are enormous. A number of these variants have been identified, although two have been the particular focus of recent publications: a serine to glycine substitution at position 49 (49S > G) and an arginine to glycine at position 389 (389R > G). The data on the in vitro behaviour of these two receptor variants is reviewed here, along with the evidence that they may affect both the risk of cardiovascular disease and the therapeutic response to beta-1 adrenoceptor antagonists.

Greater inotropic and cyclic AMP responses evoked by noradrenaline through Arg389 beta 1-adrenoceptors versus Gly389 beta 1-adrenoceptors in isolated human atrial myocardium.

1. We studied the biochemical and contractile responses of isolated human myocardial tissue expressing native receptor variants of the 389G>R beta(1)-adrenoceptor polymorphism. 2. Right atrial appendage was obtained from homozygous RR patients (n=37) and homozygous GG patients (n=17) undergoing elective cardiac surgery. The positive inotropic effect of noradrenaline in these tissues, mediated through beta(1)-adrenoceptors, was studied using electrically stimulated (1 Hz) atrial strips, as well as the effects of noradrenaline on cyclic AMP levels and cyclic AMP-dependent protein kinase. 3. Tissue from RR homozygotes (n=14) showed significantly increased inotropic potency to noradrenaline (-log EC(50), M=6.92+/-0.12) compared to GG homozygotes (n=8, -log EC(50), M=6.36+/-0.11, P<0.005). This difference was not dependent on tissue basal force. 4. Tissue cyclic AMP levels (pmol mg(-1)) were also greater in RR homozygotes (basal 34.8+/-3.7 n=12, 300 nM noradrenaline 41.4+/-7.6 n=9, 30 micro M noradrenaline 45.2+/-3.2 n=22, 0.2 mM isoprenaline 48.3+/-4.2 n=16) compared to GG homozygotes (basal 30.7+/-4.4 n=5, 300 nM noradrenaline 32.6+/-6.92 n=5, 30 micro M noradrenaline 38.1+/-3.1 n=8, 0.2 mM isoprenaline 42.6+/-5.2 n=6, P=0.007). There were no differences between the variants in terms of cyclic AMP-dependent protein kinase activity. 5. These data provide the first evidence that enhanced G-protein coupling of the R389 beta(1)-adrenoceptor variant reported in rodent fibroblast expression systems is also present in native human receptors. The functional consequence of this is to significantly alter the inotropic potency of beta(1)-adrenoceptor activation depending on its genotype at the 389 position.

Dalitz plot analysis of the decay D(+)-->K(-)pi(+)pi(+) and indication of a low-mass scalar Kpi resonance.

We study the Dalitz plot of the decay D(+)-->K(-)pi(+)pi(+) with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known Kpi resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the K(*)(0)(1430) to float, we obtain values consistent with those from PDG but the chi(2) per degree of freedom of the fit is still unsatisfactory. A good fit is found when we allow for the presence of an additional scalar resonance, with mass 797+/-19+/-43 MeV/c(2) and width 410+/-43+/-87 MeV/c(2). The mass and width of the K(*)(0)(1430) become 1459+/-7+/-5 MeV/c(2) and 175+/-12+/-12 MeV/c(2), respectively. Our results provide new information on the scalar sector in hadron spectroscopy.

A polymorphism of the human matrix gamma-carboxyglutamic acid protein promoter alters binding of an activating protein-1 complex and is associated with altered transcription and serum levels.

Matrix gamma-carboxyglutamic acid protein (MGP) is a mineral-binding extracellular matrix protein synthesized by vascular smooth muscle cells (VSMCs) and chondrocytes that is thought to be a key regulator of tissue calcification. In this study, we identified four polymorphisms in the promoter region of the human MGP gene. Transfection studies showed that the G-7A and T-138C polymorphisms have an important impact on in vitro promoter activity when transiently transfected into VSMCs. We found that one of these polymorphisms (T-138C) is significantly correlated with serum MGP levels in human subjects. Promoter deletion analysis showed that this polymorphism lies in a region of the promoter critical for transcription in VSMCs. This region contains a potential activating protein-1 (AP-1) binding element located between -142 and -136. We have demonstrated that the T-138C polymorphism results in altered binding of an AP-1 complex to this region. The -138T allelic variant binds AP-1 complexes consisting primarily of c-Jun, JunB and its partners Fra-1 and Fra-2 in rat VSMC. Furthermore, the -138T variant form of the promoter was induced following phorbol 12-myristate 13-acetate treatment, while the -138C variant was refractive to phorbol 12-myristate 13-acetate treatment, confirming that AP-1 factors preferentially bind to the -138T variant. This study therefore suggests that a common polymorphism of the MGP promoter influences binding of the AP-1 complex, which may lead to altered transcription and serum levels. This could have important implications for diseases such as atherosclerosis and aortic valve stenosis, since it strongly suggests a genetic basis for regulation of tissue calcification.

Direct measurement of the pion valence-quark momentum distribution, the pion light-cone wave function squared.

We present the first direct measurements of the pion valence-quark momentum distribution which is related to the square of the pion light-cone wave function. The measurements were carried out using data on diffractive dissociation of 500 GeV/c pi(-) into dijets from a platinum target at Fermilab experiment E791. The results show that the /q&q> light-cone asymptotic wave function describes the data well for Q2 approximately 10 (GeV/c)(2) or more. We also measured the transverse momentum distribution of the diffractive dijets.

Observation of color-transparency in diffractive dissociation of pions.

We have studied the diffractive dissociation into dijets of 500 GeV/c pions scattering coherently from carbon and platinum targets. Extrapolating to asymptotically high energies (where t(min)-->0), we find that when the per-nucleus cross section for this process is parametrized as sigma = sigma0Aalpha, alpha has values near 1.6, the exact result depending on jet transverse momentum. These values are in agreement with those predicted by theoretical calculations of color-transparency.

Search for rare and forbidden Charm Meson decays D0 --> Vl+l- and hhll.

We report results of a search for flavor-changing neutral current (FCNC), lepton flavor, and lepton-number violating decays of the D0 (and its antiparticle) into three and four bodies. Using data from Fermilab charm hadroproduction experiment E791, we examine modes with two leptons (muons or electrons) and a rho(0), K( *0), or straight phi vector meson or a nonresonant pi(pi), Kpi, or KK pair of pseudoscalar mesons. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 27 decay modes examined (18 new).

Glycerol-enhanced mini-polyacrylamide gel electrophoresis for the separation of differentially expressed DNA fragments in cDNA representational difference analysis.

Representational difference analysis (RDA) is a widely used technique in molecular biology. However, in practice, its efficiency depends on a rapid and reliable separation of the RDA fragments prior to cloning. To achieve this, we have compared and combined the separation efficiencies of conventional and MetaPhor agarose gel electrophoresis (MAGE) with a glycerol-enhanced mini-polyacrylamide gel electrophoresis (PAGE) system (Gem-PAGE). As anticipated, MetaPhor agarose provided significantly improved resolution over conventional agarose electrophoresis, but the latter remains useful to rapidly confirm the presence of RDA-enriched difference products and direct the concentration of MetaPhor agarose subsequently used for further fragment separation. Additional improvements in resolution were possible by using the Gem-PAGE system. The effect of glycerol on band definition of PAGE was most noticeable as the acrylamide to glycerol ratio (A:G) approached 1:2. Gels in which the A:G ratio was significantly above or below this resulted in both poor morphology and impaired resolution of the bands. By exploiting sequentially agarose-based and Gem-PAGE electrophoresis, the goal in RDA of "one band one product" is now realizable.

Mammographic characteristics of 115 missed cancers later detected with screening mammography and the potential utility of computer-aided detection.

PURPOSE: To retrospectively determine the mammographic characteristics of cancers missed at screening mammography and assess the ability of computer-aided detection (CAD) to mark the missed cancers. MATERIALS AND METHODS: A multicenter retrospective study accrued 1,083 consecutive cases of breast cancer detected at screening mammography. Prior mammograms were available in 427 cases. Of these, 286 had lesions visible in retrospect. The 286 cases underwent blinded review by panels of radiologists; a majority recommended recall for 112 cases. Two experienced radiologists compared prior mammograms in 110 of these cases with the subsequent screening mammograms (when cancer was detected), noting mammographic characteristics of breast density, lesion type, size, morphology, and subjective reasons for possible miss. The prior mammograms were then analyzed with a CAD program. RESULTS: There were 110 patients with 115 cancers. On the prior mammograms with missed cancers, 35 (30%) of the 115 lesions were calcifications, with 17 of 35 (49%) clustered or pleomorphic. Eighty of the 115 (70%) were mass lesions, with 32 of 80 (40%) spiculated or irregular. For calcifications and masses, the most frequently suggested reasons for possible miss were dense breasts (12 of 35; 34%) and distracting lesions (35 of 80; 44%), respectively. CAD marked 30 (86%) of 35 missed calcifications and 58 (73%) of 80 missed masses. CONCLUSION: Detection errors affected cases with calcifications and masses. CAD marked most (77%; 88 of 115) cancers missed at screening mammography that radiologists retrospectively judged to merit recall.

The genetics of essential hypertension.

Essential hypertension is an escalating problem for industrialized populations. It is currently seen as a 'complex' genetic trait caused by multiple susceptibility genes the effects of which are modulated by gene-environment and gene-gene interactions. Nevertheless, the success to date in identifying these susceptibility genes has been very limited. A number of candidates has been proposed, but demonstrating consistently the linkage or association with hypertension has been problematic. The data for angiotensinogen is undoubtedly the most extensive and meta-analysis has confirmed a significant association overall, although the risk contributed by this gene appears to be modest (odds ratio of 1.2). Identifying further genes - probably conferring even smaller attributable risks - represents a major challenge for future developments in this area. This contrasts markedly with the success that has been achieved in the past 5 years in solving the molecular genetics of a number of rare familial hypertension syndromes. The true incidences of some of these disorders may be higher than first appreciated, but it is still unclear if the genes for these syndromes also play a part in essential hypertension. A more complete understanding of the genetic basis of essential hypertension should be possible in the coming years using new strategies that take advantage of the information provided by the human genome project. This knowledge will irrevocably change the way we approach this disease in terms of its diagnosis, risk assessment for end-points such as stroke and heart disease, and the customised treatment that might be offered in the future.

Study of the D(+)(s)-->pi(-)pi(+)pi(+) decay and measurement of f(0) masses and widths.

From a sample of 848+/-44 D(+)(s)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)(s)-->pi(-)pi(+)pi(+))/gamma(D(+)(s)-->straight phipi(+)) = 0.245+/-0.028(+0.019)(-0.012). Using a Dalitz plot analysis of this three body decay, we find significant contributions from the channels rho(0)(770)pi(+), rho(0)(1450)pi(+), f(0)(980)pi(+), f(2)(1270)pi(+), and f(0)(1370)pi(+). We also present the values obtained for masses and widths of the resonances f(0)(980) and f(0)(1370).

Experimental evidence for a light and broad scalar resonance in D(+) --> pi(-)pi(+)pi(+) decay.

From a sample of 1172 +/- 61 D(+)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)-->pi(-)pi(+)pi(+))/gamma(D(+)-->K-pi(+)pi(+)) = 0.0311 +/- 0.0018(+0.0016)(-0.0026). Using a coherent amplitude analysis to fit the Dalitz plot of these decays, we find strong evidence that a scalar resonance of mass 478(+24)(-23) +/- 17 MeV/c(2) and width 324(+42)(-40) +/- 21 MeV/c(2) accounts for approximately half of all decays.