Studies on thyroidal protein biosynthesis in relation to thyroid hormone biosynthesis

1. The object of the study was the isolation from thyreoglobulin of peptides containing iodothyronines or iodotyrosines, followed by investigation of these peptides as the actual or potential sites of thyroid hormone synthesis in thyreoglobulin.2. A cell free preparation capable of incorporating amino acids into protein was isolated from rat thyroid. Some of the unusual properties of this preparation were studied.3. Thyroglobulin containing ¹⁴C-amino acids was isolated from whole rat thyroids after Incubation with ¹⁴C-amino acids. Under similar conditions sheep thyroid slices rapidly incorporated ¹⁴C- amino acids and ¹³¹I⁻ yielding thyroglobulia highly labelled with both isotopes.4. Thyroglobulin isolated from sheep thyroid slices was purified, by fractionation with ammonium sulphate or by gel filtration on Sephadex G-200. The purity of the preparation was determined by a variety of methods including gel filtration, electrophoresis and ultraoentrifugation. Suorose gradient centrifugation revealed a highly iodinated lighter protein fraction.5. Labelled thyroglobulin was hydrolysed by α-chymotrypsin and the resulting hydrolysate subjected to electrophoresis followed by chromatography at right angles (peptide mapping). Autoradiograms of these peptide maps revealed the presence of a number of peptides labelled with ¹³¹I₂ and a larger number labelled with ¹⁴C-tyrosine. None of the ¹³¹I-peptides was unequivocally labelled with ¹⁴C- tyrosine.6. The most highly labelled ¹³¹ I-peptides were isolated, in some cases purified by electrophoresis at pH 8.2, and their iodoamino acid contents found after pronase hydrolysis and chromatography. Each peptide contained only one iodotyrosine confirming the specific nature of tyrosyl iodination indicated by the small number of intensely labelled ¹³¹I-peptides compared with a larger number of ¹⁴C—tyrosine peptides.7. The approximate sizes of the ¹³¹I-peptides were determined by estimation ©i the bonds hydrolysed by αC-chymotrypsin and by gel filtration of the peptides on Sephadex 0-25.8. During the incorporation of ¹³¹I⁻ into thyroid slices over a period of 5 hr. the activity of each ¹³¹I-peptide, as a percentage of the total ¹³¹I₂ in thyroglobulin, did not alter although the ratio of the ¹³¹I-activities of mono- to diiodotyrosine fell throughout this period.9. Monoiodotyrosyl peptide A₅ was iodinated chemically with ¹³¹I₂. The product was not identical with already isolated diiodotyrosyl peptides of similar mobilities on peptide mapping.10. Peptide A₅ was associated with another peptide (separated by electrophoresis at pH 8.2) whose products of iodination were identical with those of A₅ and which, it is suggested, is the unlodinated form of A₅.11. This latter peptide taken together with A₅, is present as 4 moles per mole of thyroglobulin as determined by iodination with 131I₂ of known specifio aotivity. Two other peptides, N₉ and N₉ₐ' are each present as 5 moles per mole of thyroglobulin. It ya is suggested that this confirms the evidence that thyroglobulin oomprises four identioal sub-units and that iodotyrosyl residues can remain partially uniodinated as well as being mono- or diiodinated

Adjunctive strategies in the management of resistant, 'undilatable' coronary lesions after successfully crossing a CTO with a guidewire.

Successful revascularisation of chronic total occlusions (CTOs) remains one of the greatest challenges in the era of contemporary percutaneous coronary intervention (PCI). Such lesions are encountered with increasing frequency in current clinical practice. A predictable increase in the future burden of CTO management can be anticipated given the ageing population, increased rates of renal failure, graft failure and diabetes mellitus. Given recent advances and developments in CTO PCI management, successful recanalisation can be anticipated in the majority of procedures undertaken at high-volume centres when performed by expert operators. Despite advances in device technology, the management of resistant, calcific lesions remains one of the greatest challenges in successful CTO intervention. Established techniques to modify calcific lesions include the use of high-pressure non-compliant balloon dilation, cutting-balloons, anchor balloons and high speed rotational atherectomy (HSRA). Novel approaches have proven to be safe and technically feasible where standard approaches have failed. A step-wise progression of strategies is demonstrated, from well-recognised techniques to techniques that should only be considered when standard manoeuvres have proven unsuccessful. These methods will be described in the setting of clinical examples and include use of very high-pressure non-compliant balloon dilation, intentional balloon rupture with vessel dissection or balloon assisted micro-dissection (BAM), excimer coronary laser atherectomy (ECLA) and use of HSRA in various 'offlabel' settings

Discovery of a very X-ray luminous galaxy cluster at z=0.89 in the WARPS survey

We report the discovery of the galaxy cluster ClJ1226.9+3332 in the Wide Angle ROSAT Pointed Survey (WARPS). At z=0.888 and L_X=1.1e45 erg/s (0.5-2.0 keV, h_0=0.5) ClJ1226.9+3332 is the most distant X-ray luminous cluster currently known. The mere existence of this system represents a huge problem for Omega_0=1 world models. At the modest (off-axis) resolution of the ROSAT PSPC observation in which the system was detected, ClJ1226.9+3332 appears relaxed; an off-axis HRI observation confirms this impression and rules out significant contamination from point sources. However, in moderately deep optical images (R and I band) the cluster exhibits signs of substructure in its apparent galaxy distribution. A first crude estimate of the velocity dispersion of the cluster galaxies based on six redshifts yields a high value of 1650 km/s, indicative of a very massive cluster and/or the presence of substructure along the line of sight. While a more accurate assessment of the dynamical state of this system requires much better data at both optical and X-ray wavelengths, the high mass of the cluster has already been unambiguously confirmed by a very strong detection of the Sunyaev-Zel'dovich effect in its direction (Joy et al. 2001). Using ClJ1226.9+3332 and ClJ0152.7-1357 (z=0.835), the second-most distant X-ray luminous cluster currently known and also a WARPS discovery, we obtain a first estimate of the cluster X-ray luminosity function at 0.8<z<1.4 and L_X>5e44 erg/s. Using the best currently available data, we find the comoving space density of very distant, massive clusters to be in excellent agreement with the value measured locally (z<0.3), and conclude that negative evolution is not required at these luminosities out to z~1. (truncated)Comment: accepted for publication in ApJ Letters, 6 pages, 2 figures, uses emulateapj.st

The WARPS survey - IV: The X-ray luminosity-temperature relation of high redshift galaxy clusters

We present a measurement of the cluster X-ray luminosity-temperature relation out to high redshift (z~0.8). Combined ROSAT PSPC spectra of 91 galaxy clusters detected in the Wide Angle ROSAT Pointed Survey (WARPS) are simultaneously fit in redshift and luminosity bins. The resulting temperature and luminosity measurements of these bins, which occupy a region of the high redshift L-T relation not previously sampled, are compared to existing measurements at low redshift in order to constrain the evolution of the L-T relation. We find a best fit to low redshift (z1 keV, to be L proportional to T^(3.15\pm0.06). Our data are consistent with no evolution in the normalisation of the L-T relation up to z~0.8. Combining our results with ASCA measurements taken from the literature, we find eta=0.19\pm0.38 (for Omega_0=1, with 1 sigma errors) where L_Bol is proportional to (1 + z)^eta T^3.15, or eta=0.60\pm0.38 for Omega_0=0.3. This lack of evolution is considered in terms of the entropy-driven evolution of clusters. Further implications for cosmological constraints are also discussed.Comment: 11 pages, 7 figures, accepted for publication in MNRA

Using Molecular Data to Identify Lungless Salamander Kinds

Baraminology is the study of God’s created kinds as described in Genesis 1. Holobaramins are scientific approximations of these kinds, identified by building up monobaramins (smaller, continuous groups of organisms) and dividing apobaramins (larger, discontinuous groups of organisms). The lungless salamander family (Caudata: Plethodontidae), composed of over 500 species in 29 genera, have been grouped together by herpetologists for almost 200 years. Our previous research indicates that lungless salamander holobaramin(s) are found somewhere between the genus and family levels. The goal of this study is to further investigate the baraminology of these organisms by reanalyzing a prominent study of lungless salamander phylogeny using molecular baraminology techniques. DNA sequences from two mitochondrial (CYTB, ND4) and one nuclear gene (RAG-1) were gathered from the GenBank database and aligned using MEGA. Sequences from each gene (plus a concatenated dataset of all genes combined) were analyzed using hierarchical clustering and classic multidimensional scaling in RStudio as well as distance correlation analysis in BARCLAY. These analyses indicate that all lungless salamanders cluster into one large group, separate from the outgroups, and are therefore an apobaramin. The data also suggest the presence of at least five major groups of genera, clustering in two subgroups that correspond to modern subfamilies (Plethodontinae and Hemidactyliinae). Hemidactylium (Tribe Hemidactyliini) clusters separately from members of Tribe Spelerpini. Batrachoseps (Tribe Batrachosepini) also seems to cluster separately from members of Tribe Bolitoglossini. Desmognathus and Phaeognathus (Tribe Desmognathini), on the other hand, cluster with other members of Subfamily Plethodontinae. These five groups represent monobaramins, possibly holobaramins according to DCA analyses, and indicate that lungless salamander holobaramin(s) lie between the tribe and subfamily levels. Morphological, hybridization, and historical taxonomic research by our team are consistent with these results. We will continue to identify holobaramins by increasing the number of species we include in our analyses and using genetic distance data to expand our hybridization analysis. Despite the preliminary nature of our conclusions, we are the first to conduct baraminological analyses in this family of salamanders

Using Taxonomic and Hybridization Data to Identify Lungless Salamander Kinds

Baraminology is the study of God’s created kinds as described in Genesis 1. Holobaramins (groups of known organisms sharing continuity and bounded by discontinuity) are scientific approximations of these kinds identified by building up monobaramins (smaller, continuous groups) and dividing apobaramins (larger, discontinuous groups). The lungless salamanders (Caudata: Plethodontidae), composed of over 500 species in 29 genera, have been grouped together by herpetologists for almost 200 years. This consistent taxonomic history suggests that the family represents a cognitum (group of organisms recognized through the human cognitive senses as belonging together) and possibly apobaramin. The goals of the present study are to: 1) identify characteristics from the herpetological literature shared by all or most of the lungless salamanders; 2) survey the three major taxonomic schemes from the past 60 years to identify consistent groupings of genera over time; and 3) compile records of hybridization to demonstrate continuity among various groups of species. Our literature search suggests that lungless salamanders do, in fact, share a tremendous number of unique characteristics (or combinations of characteristics) and are therefore an apobaramin. The survey of taxonomic schemes identifies seven monobaramins ranging from supergenus to tribe or subfamily level. Many records of interspecific hybridization (but not intergeneric or intertribal) reveal fourteen monobaramins at the genus level ranging in size from 2-14 species. These data suggest that lungless salamander holobaramin(s) are found somewhere between the genus and family levels (possibly modern tribe level). Other research by our team, utilizing morphological and molecular datasets, yields similar results. We will continue our attempts to identify holobaramin(s) by conducting additional morphological and molecular analyses and utilizing genetic distance data to expand our hybridization analysis. Despite the preliminary nature of our conclusions, we are the first to conduct baraminological analyses in this family of salamanders

The Butcher-Oemler Effect in High Redshift X-ray Selected Clusters

We are engaged in a wide-field, multi-colour imaging survey of X-ray selected clusters at intermediate and high redshift. We present blue fractions for the first 8 out of 29 clusters, covering almost a factor of 100 in X-ray luminosity. We find no correlation of blue fraction with redshift or X-ray luminosity. The lack of a correlation with L$_{X}$, places strong constraints on the importance of ram-pressure stripping as a driver of the Butcher-Oemler effect.Comment: 4 pages, 4 figures, to be puplished in the proceedings of the ''Sesto 2001-Tracing Cosmic Evolution with Galaxy Clusters'', Sesto 3-6 July 2001, Italy, eds, Stefano Borgan

A randomized, blinded, controlled trial investigating the gastrointestinal health effects of drinking water quality.

A double-blinded, randomized, controlled trial was carried out in in Melbourne, Australia, to determine the contribution of drinking water to gastroenteritis. Melbourne is one of the few major cities in the world that draws drinking water from a protected forest catchment with minimal water treatment (chlorination only). Six hundred families were randomly allocated to receive either real or sham water treatment units (WTUs) installed in their kitchen. Real units were designed to remove viruses, bacteria, and protozoa. Study participants completed a weekly health diary reporting gastrointestinal symptoms during the 68-week observation period. There were 2,669 cases of highly credible gastroenteritis (HCG) during the study (0.80 cases/person/year). The ratio of HCG episode rates for the real WTU group compared to the sham WTU group was 0.99 (95% confidence interval, 0.85-1.15, p = 0.85). We collected 795 fecal specimens from participants with gastroenteritis, and pathogens were not more significantly common in the sham WTU group. We found no evidence of waterborne disease in Melbourne. The application of this methodology to other water supplies will provide a better understanding of the relationship between human health and water quality