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Michael Wright

Publications and source records attributed to Michael Wright.

At least 19 recordsLinked to original sources
PubMed2026

Toward a unified approach: Considerations for bioinformatic and sequencing activities & data in wastewater surveillance of biologic public health threats.

Genomic technologies such as PCR and next-generation sequencing (NGS) have greatly advanced public health surveillance, especially during COVID-19, by enabling detailed tracking of pathogen spread, origins, and variants. While PCR is vital for targeted detection, falling NGS costs have made large-scale, high-throughput sequencing more feasible, supporting broader pathogen monitoring-including the detection of vaccine escape variants and new strains. Applying NGS to wastewater offers valuable population-level insights but faces challenges such as variable sample complexity, the need for skilled staff, suitable platforms, and robust IT infrastructure. Although there are currently a lot of efforts towards defining guidelines for sampling, analysis, and integrating wastewater data into public health policy, such as the recently published International Cookbook for Wastewater Practitioners, they often lack universal applicability, emphasizing the analytical approaches in favour of the NGS-based approaches. However, standardising protocols for sampling, sequencing, and analysis is crucial to ensure reliable, comparable data across surveillance systems worldwide. Pilot studies and continuous refinement are recommended to overcome implementation hurdles and fully realise the benefits of NGS in wastewater surveillance. This work attempts to outline these challenges and opportunities across the entire wastewater surveillance workflow, from data generation to reporting, and provide some concrete suggestions and considerations across the spectrum of activities. We further highlight that the infrastructure, funding and government-policy context in which surveillance operates acts as an enabling condition for these activities, and that technical standardisation alone is unlikely to deliver durable, comparable surveillance in its absence.

considerations↗
PubMed2006

Design and synthesis of conformationally constrained tri-substituted ureas as potent antagonists of the human glucagon receptor.

A series of conformationally constrained tri-substituted ureas were synthesized, and their potential as glucagon receptor antagonists was evaluated. This effort resulted in the identification of compound 4a, which had a binding IC50 of 4.0 nM and was shown to reduce blood glucose levels at 3 mg/kg in glucagon-challenged mice containing a humanized glucagon receptor. Compound 4a was efficacious in correcting hyperglycemia induced by a high fat diet in transgenic mice at an oral dose as low as 3 mg/kg.

Animals↗
PubMed2006

Novel FGFR3 mutations creating cysteine residues in the extracellular domain of the receptor cause achondroplasia or severe forms of hypochondroplasia.

Achondroplasia (ACH) and hypochondroplasia (HCH) are two autosomal-dominant skeletal disorders caused by recurrent missense FGFR3 mutations in the transmembrane (TM) and tyrosine kinase 1 (TK1) domains of the receptor. Although 98% of ACH cases are accounted for by a single G380R substitution in the TM, a common mutation (N540K) in the TK1 region is detected in only 60-65% of HCH cases. The aim of this study was to determine whether the frequency of mutations in patients with HCH was the result of incomplete mutation screening or genetic heterogeneity. Eighteen exons of the FGFR3 gene were entirely sequenced in a cohort of 25 HCH and one ACH patients in whom common mutations had been excluded. Seven novel missense FGFR3 mutations were identified, one causing ACH and six resulting in HCH. Six of these substitutions were located in the extracellular region and four of them creating additional cysteine residues, were associated with severe phenotypes. No mutations were detected in 19 clinically diagnosed HCH patients. Our results demonstrate that the spectrum of FGFR3 mutations causing short-limb dwarfism is wider than originally recognised and emphasise the requirement for complete screening of the FGFR3 gene if appropriate genetic counselling is to be offered to patients with HCH or ACH lacking the most common mutations and their families.

Achondroplasia↗
PubMed2006

Hydrogel polymer appears to mimic the performance of the GroEL/GroES molecular chaperone machine.

Controlled protein folding/refolding remains a substantial challenge to the biotechnology industry. Robust and adaptable artificial polymer molecular chaperones could make important contributions towards solving this problem. Taking inspiration from the mechanism of the GroEL/GroES molecular chaperone machine, we report the preparation and testing of a selection of cross-linked thermo-responsive hydrogels, one of which is shown to assist quantitative refolding of a stringent unfolded protein substrate (mitochondrial malate dehydrogenase [mMDH]) during temperature cycling between hydrophobic and hydrophilic states. To our knowledge, this is the first hydrogel-only artificial polymer molecular chaperone to be derived, which is also potentially a generic artificial polymer molecular chaperone for use in a folding bioreactor.

Chaperonin 10↗
PubMed2006

Diadenosine polyphosphate analog controls postsynaptic excitation in CA3-CA1 synapses via a nitric oxide-dependent mechanism.

Previously, we have described the modulatory effect of diadenosine polyphosphates Ap4A and Ap5A on synaptic transmission in the rat hippocampal slices mediated by presynaptic receptors (Klishin et al., 1994). In contrast, we now describe how nonhydrolyzable Ap4A analog diadenosine-5',5'''-P1,P4-[beta,beta'-methylene]tetraphosphate (AppCH2ppA) at low micromolar concentrations exerts strong nondesensitizing inhibition of orthodromically evoked field potentials (OFPs) without affecting the amplitude of excitatory postsynaptic currents and antidromically evoked field potentials, as recorded in hippocampal CA1 zone. The effects of AppCH2ppA on OFPs are eliminated by a P2 receptor antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS) but not mimicked by purinoceptor agonists alpha,beta-methylene-ATP and adenosine 5'-O-(3-thio)-triphosphate, indicating that a P2-like receptor is involved but not one belonging to the conventional P2X/P2Y receptor classes. Diadenosine polyphosphate receptor (P4) antagonist Ip4I (diinosine tetraphosphate) was unable to modulate AppCH2ppA effects. Thus, the PPADS-sensitive P2-like receptor for AppCH2ppA seems to control selectively dendritic excitation of the CA1 neurons. The specific nitric oxide (NO)-scavenger 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide is shown to significantly attenuate AppCH2ppA-mediated inhibitory effects, indicating that NO is involved in the cascade of events initiated by AppCH2ppA. Further downstream mediation by adenosine A1 receptors is also demonstrated. Hence, AppCH2ppA-mediated effects involve PPADS-sensitive P2-like receptor activation leading to the production of NO that stimulates intracellular synthesis of adenosine, causing in turn postsynaptic A1 receptor activation and subsequent postsynaptic CA1 dendritic inhibition. Such spatially selective postsynaptic dendritic inhibition may influence dendritic electrogenesis in pyramidal neurons and consequently mediate control of neuronal network activity.

Adenosine↗
PubMed2006

Investigation into the interactions between diadenosine 5',5'''-P1,P4-tetraphosphate and two proteins: molecular chaperone GroEL and cAMP receptor protein.

Diadenosine 5',5'''-P(1),P(4)-tetraphosphate (Ap(4)A) is a dinucleoside polyphosphate found ubiquitously in eukaryotic and prokaryotic cells. Despite Ap(4)A being universal, its functions have proved to be difficult to define, although they appear to have a strong presence during cellular stress. Here we report on our investigations into the nature and properties of putative Ap(4)A interactions with Escherichia coli molecular chaperone GroEL and cAMP receptor protein (CRP). We confirm previous literature observations that GroEL is an Ap(4)A binding protein and go on to prove that binding of Ap(4)A to GroEL involves a set of binding sites (one per monomer) distinct from the well-known GroEL ATP/ADP sites. Binding of Ap(4)A to GroEL appears to enhance ATPase rates at higher temperatures, encourages the release of bound ADP, and may promote substrate protein release through differential destabilization of the substrate protein-GroEL complex. We suggest that such effects should result in enhanced GroEL/GroES chaperoning activities that could be a primary reason for the improved yields of the refolded substrate protein observed during GroEL/GroES-assisted folding and refolding at >or=30 degrees C in the presence of Ap(4)A. In contrast, we were unable to obtain any data to support a direct role for Ap(4)A interactions with CRP.

Base Sequence↗
PubMed2006

The mechanism of GroEL/GroES folding/refolding of protein substrates revisited.

The thermodynamics and kinetics of zinc-cytochrome c (ZnCyt c) interactions with Escherichia coli molecular chaperone GroEL (Chaperonin 60; Cpn60) are described. Zinc(II)-porphyrin represents a flexible fluorescent probe for thermodynamic complex formation between GroEL and ZnCyt c, as well as for stopped-flow fluorescence kinetic experiments. Data suggests that GroEL and GroEL/GroES-assisted refolding of unfolded ZnCyt c takes place by a mechanism that is quite close to the Anfinsen Cage hypothesis for molecular chaperone activity. However, even in the presence of ATP, GroEL/GroES-assisted refolding of ZnCyt c takes place at approximately half the rate of refolding of ZnCyt c alone. On the other hand, there is little evidence for refolding behaviour consistent with the Iterative Annealing hypothesis. This includes a complete lack of GroEL or GroEL/GroES-assisted enhancement of refolding rate constant k(2) associated with the unfolding of a putative misfolded state I (Zn) on the pathway to the native state. Reviewing our data in the light of data from other laboratories, we observe that all forward rate enhancements or reductions could be accounted for in terms of thermodynamic coupling (adjusting positions of refolding equilibria) due to binding interactions between GroEL and unfolded protein substrates, driven by thermodynamic considerations. Therefore, we propose that passive kinetic partitioning should be considered the core mechanism of the GroEL/GroES molecular chaperone machinery, wherein the core function is to bind unfolded protein substrates leading to a blockade of aggregation pathways and to increases in molecular flux through productive folding pathway(s).

Chaperonin 10↗
PubMed2006

Germline LEMD3 mutations are rare in sporadic patients with isolated melorheostosis.

To further explore the allelic heterogeneity within the group of LEMD3-related disorders, we have screened a larger series of patients including 5 probands with osteopoikilosis or Buschke-Ollendorff syndrome (BOS), 2 families with the co-occurrence of melorheostosis and BOS, and 12 unrelated patients with isolated melorheostosis. Seven novel LEMD3 mutations were identified, all predicted to result in loss-of-function of the protein. We confirm that loss-of-function mutations in the LEMD3 gene can result in either osteopoikilosis or BOS. However, LEMD3 germline mutations were only found in two melorheostosis patients belonging to a different BOS family and one sporadic patient with melorheostosis. The additional presence of osteopoikilosis lesions in these patients seemed to distinguish them from the group of sporadic melorheostosis patients where no germline LEMD3 mutation was identified. Somatic mosaicism for a LEMD3 mutation in the latter group was also not observed, and therefore we must conclude that the genetic defect in the majority of sporadic and isolated melorheostosis remains unknown.

Alleles↗
PubMed2006

The duality of LysU, a catalyst for both Ap4A and Ap3A formation.

Heat shock inducible lysyl-tRNA synthetase of Escherichia coli (LysU) is known to be a highly efficient diadenosine 5',5'''-P1,P4-tetraphosphate (Ap4A) synthase. However, we use an ion-exchange HPLC technique to demonstrate that active LysU mixtures actually have a dual catalytic activity, initially producing Ap4A from ATP, before converting that tetraphosphate to a triphosphate. LysU appears to be an effective diadenosine 5',5'''-P1,P3-triphosphate (Ap3A) synthase. Mechanistic investigations reveal that Ap3A formation requires: (a) that the second step of Ap4A formation is slightly reversible, thereby leading to a modest reappearance of adenylate intermediate; and (b) that phosphate is present to trap the intermediate (either as inorganic phosphate, as added ADP, or as ADP generated in situ from inorganic phosphate). Ap3A forms readily from Ap4A in the presence of such phosphate-based adenylate traps (via a 'reverse-trap' mechanism). LysU is also clearly demonstrated to exist in a phosphorylated state that is more physically robust as a catalyst of Ap4A formation than the nonphosphorylated state. However, phosphorylated LysU shows only marginally improved catalytic efficiency. We note that Ap3A effects have barely been studied in prokaryotic organisms. By contrast, there is a body of literature that describes Ap3A and Ap4A having substantially different functions in eukaryotic cells. Our data suggest that Ap3A and Ap4A biosynthesis could be linked together through a single prokaryotic dual 'synthase' enzyme. Therefore, in our view there is a need for new research into the effects and impact of Ap3A alone and the intracellular [Ap3A]/[Ap4A] ratio on prokaryotic organisms.

Blotting, Western↗
PubMed2005

Novel fluorescent labelled affinity probes for diadenosine-5',5'''-P1,P4-tetraphosphate (Ap4A)-binding studies.

Tandem synthetic-biosynthetic procedures were used to prepare two novel fluorescent labelled affinity probes for diadenosine-5',5'''-P1,P4-tetraphosphate (Ap4A)-binding studies. These compounds (dial-mant-Ap4A and azido-mant-Ap4A) are shown to clearly distinguish known Ap4A-binding proteins from Escherichia coli (LysU and GroEL) and a variety of other control proteins. Successful labelling of chaperonin GroEL appears to be allosteric with respect to the well-characterized adenosine 5'-triphosphate (ATP)-binding site, suggesting that GroEL possesses a distinct Ap4A-binding site.

Allosteric Site↗
PubMed2005

Direct observation (NMR) of the efficacy of glucagon receptor antagonists in murine liver expressing the human glucagon receptor.

The demonstration of pharmacodynamic efficacy of novel chemical entities represents a formidable challenge in the early exploration of synthetic lead classes. Here, we demonstrate a technique to validate the biological efficacy of novel antagonists of the human glucagon receptor (hGCGR) in the surgically removed perfused liver prior to the optimization of the pharmacokinetic properties of the compounds. The technique involves the direct observation by (13)C NMR of the biosynthesis of [(13)C]glycogen from [(13)C]pyruvate via the gluconeogenic pathway. The rapid breakdown of [(13)C]glycogen (glycogenolysis) following the addition of 50 pM exogenous glucagon is then monitored in real time in the perfused liver by (13)C NMR. The concentration-dependent inhibition of glucagon-mediated glycogenolysis is demonstrated for both the peptidyl glucagon receptor antagonist 1 and structurally diverse synthetic antagonists 2-7. Perfused livers were obtained from a transgenic mouse strain that exclusively expresses the functional human glucagon receptor, conferring human relevance to the activity observed with glucagon receptor antagonists. This technique does not provide adequate quantitative precision for the comparative ranking of active compounds, but does afford physiological evidence of efficacy in the early development of a chemical series of antagonists.

Animals↗
PubMed2005

Dominant negative mutations in the C-propeptide of COL2A1 cause platyspondylic lethal skeletal dysplasia, torrance type, and define a novel subfamily within the type 2 collagenopathies.

Platyspondylic lethal skeletal dysplasia (PLSD) Torrance type (PLSD-T) is a rare skeletal dysplasia characterized by platyspondyly, brachydactyly, and metaphyseal changes. Generally a perinatally lethal disease, a few long-term survivors have been reported. Recently, mutations in the carboxy-propeptide of type II collagen have been identified in two patients with PLSD-T, indicating that PLSD-T is a type 2 collagen-associated disorder. We studied eight additional cases of PLSD-T and found that all had mutations in the C-propeptide domain of COL2A1. The mutational spectrum includes missense, stop codon and frameshift mutations. All non-sense mutations were located in the last exon, where they would escape non-sense-mediated RNA-decay. We conclude that PLSD-T is caused by mutations in the C-propeptide domain of COL2A1, which lead to biosynthesis of an altered collagen chain (as opposed to a null allele). Similar mutations have recently been found to be the cause of spondyloperipheral dysplasia, a non-lethal dominant disorder whose clinical and radiographical features overlap those of the rare long-term survivors with PLSD-T. Thus, spondyloperipheral dysplasia and PLSD-T constitute a novel subfamily within the type II collagenopathies, associated with specific mutations in the C-propeptide domain and characterized by distinctive radiological features including metaphyseal changes and brachydactyly that set them apart from other type 2 collagenopathies associated with mutations in the triple-helical domain of COL2A1. The specific phenotype of C-propeptide mutations could result from a combination of diminished collagen fibril formation, toxic effects through the accumulation of unfolded collagen chains inside the chondrocytes, and alteration of a putative signaling function of the carboxy-propeptide of type 2 collagen.

Child, Preschool↗
PubMed2005

Factor XIII deficiency: new nonsense and deletion mutations in the human factor XIIIA gene.

We identified five disease-causing mutations in six factor XIII deficient patients from four unrelated families: two novel nonsense mutations (nucleotide 979C-->T corresponding to Arg326Stop; and nucleotide 2075G-->A corresponding to Trp691 Stop), one novel deletion of a single nucleotide (nucleotide 708G or 709G), one previously reported missense mutation (nucleotide 888C-->G corresponding to Ser295Arg), and a previously reported splice site mutation (nucleotide 319G-->T at the last position of exon 3). The phenotypic consequences of these mutations are discussed.

Adolescent↗
PubMed2004

Synthesis of novel fluorescent-labelled dinucleoside polyphosphates.

A novel tandem synthetic-biosynthetic procedure is described for the synthesis of four new fluorescent dinucleoside polyphosphates: mant-Ap4A, mant-AppCH2ppA, TNP-Ap4A and TNP-AppCH2ppA. These compounds are expected to supplement the existing etheno (epsilon) and 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) labelled derivatives, being the fluorescent probes of choice to investigate polyphosphate/enzyme binding behaviour.

Boron Compounds↗
PubMed2004

Interaction between luminance gratings and disparity gratings.

It was shown from geometry and photographic measurement that the shading pattern for a sinusoidal corrugated surface of frequency f approximates to a luminance-defined grating of frequency f, 2f or f + 2f in specific relative phase. It was confirmed that a luminance grating modifies the appearance of a suprathreshold stereoscopic corrugated surface, suggesting an interaction between shading and binocular disparity. Disparity thresholds for detecting random-dot, disparity-defined gratings of spatial frequency 0.2 or 0.4 c/deg were measured in the presence of luminance gratings of spatial frequency 0.4 c/deg with the same orientation. Phase-specific facilitation of disparity thresholds was greatest for a phase relationship inconsistent with shading of a corrugated surface, and was disrupted by positional uncertainty. The presence of texture-defined lines (which served to mark explicitly the successive spatial locations of salient depth features in the image) produced a similar pattern of facilitation, in the absence of shape-from-shading cues. The pattern of results indicates direct local interactions, including spatial cueing, rather than interaction of depth cues.

Adult↗
PubMed2004

A prospective study of the roles, responsibilities and stresses of chaplains working within a hospice.

Spiritual care is an integral part of palliative care and if asked, most members of a palliative care team would state they address spiritual issues. The majority of hospices have support from a chaplain. This study was to determine the roles of chaplains within hospices and to look at their levels of stress. A questionnaire containing both open and closed questions was sent to chaplains working within hospices in the UK. The questionnaire enquired about number of sessions, specific roles of chaplain, whether they were members of the multidisciplinary team and their sources of internal support. Stress was measured on a 10-point Likert scale and the GHQ12. One hundred and fifteen questionnaires were returned, with a 72% response rate. The majority (62%) defined their denomination as Church of England and Free Church (24%); 71% of respondents had parish commitments in addition to their hospice role. Roles were predominantly defined as spiritual care of patients and staff (95%) and bereavement support of relatives (76%) and 75% regularly attended the multidisciplinary meetings. Senior medical and nursing staff and other chaplains were perceived as providing most support. Median Likert score for stressfulness was 5, and 23% scored at or above the threshold on the GHQ12 for identifiable psychological morbidity. Clear role definition was associated with less perceived stress whereas the provision of bereavement support was associated with statistically significant increased perceived stress. The role of a chaplain within a hospice is varied and this study suggests that the provision of training and formal support is to be recommended.

Attitude of Health Personnel↗
PubMed2003

The predictive power of low-density lipoprotein cholesterol for coronary calcification.

BACKGROUND: Chronic elevation of low-density lipoprotein cholesterol is a major risk factor for developing atherosclerosis. The purpose of this study was to examine the correlation and predictive power of low-density lipoprotein cholesterol for calcified atheromatous disease as measured by electron beam computed tomography. METHODS: Six-thousand and ninety-three subjects underwent electron beam computed tomography of their coronary arteries, serum lipid testing, body fat determination and assessment of health status by questionnaire. Predictive power of low-density lipoprotein cholesterol for calcified atherosclerotic plaque was determined by correlations and multivariate logistic regression. RESULTS: The correlation between low-density lipoprotein cholesterol and calcified plaque score was very modest (r=0.055, P<0.001). There was a trend toward increasing calcified plaque with increasing levels of low-density lipoprotein cholesterol. Multivariate logistic regression revealed that low-density lipoprotein cholesterol is a modest but significant predictor of calcified coronary plaque. After adjusting for age, gender and high-density lipoprotein cholesterol, the risk of having any calcified plaque was 1.05-times higher for each 10 mg/dl increase in low-density lipoprotein cholesterol (P<0.001). Individuals with a low-density lipoprotein cholesterol level above 160 mg/dl had a 62% increase in odds for the presence of calcified plaque. CONCLUSIONS: Low-density lipoprotein cholesterol is weakly correlated with and predictive of calcified atherosclerotic plaque burden as measured by electron beam computed tomography. Higher levels of low-density lipoprotein cholesterol are associated with increased risk for the presence of calcified atheromas.

Aged↗