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result(s) for
"Hewitt, Phillip"
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Assessing the mechanism and therapeutic potential of modulators of the human Mediator complex-associated protein kinases
by
Dale, Trevor C
,
Court, Will
,
Weigt, Stefan
in
Animals
,
Anti-Inflammatory Agents - administration & dosage
,
Anti-Inflammatory Agents - adverse effects
2016
Mediator-associated kinases CDK8/19 are context-dependent drivers or suppressors of tumorigenesis. Their inhibition is predicted to have pleiotropic effects, but it is unclear whether this will impact on the clinical utility of CDK8/19 inhibitors. We discovered two series of potent chemical probes with high selectivity for CDK8/19. Despite pharmacodynamic evidence for robust on-target activity, the compounds exhibited modest, though significant, efficacy against human tumor lines and patient-derived xenografts. Altered gene expression was consistent with CDK8/19 inhibition, including profiles associated with super-enhancers, immune and inflammatory responses and stem cell function. In a mouse model expressing oncogenic beta-catenin, treatment shifted cells within hyperplastic intestinal crypts from a stem cell to a transit amplifying phenotype. In two species, neither probe was tolerated at therapeutically-relevant exposures. The complex nature of the toxicity observed with two structurally-differentiated chemical series is consistent with on-target effects posing significant challenges to the clinical development of CDK8/19 inhibitors. Healthy cells in the human body can become cancerous if they gain genetic mutations that allow them to rapidly grow and divide. Some types of cancer respond better to drug treatments than others and tumors often develop resistance to a particular drug treatment after a while. Because of this, researchers are always searching for new molecules to develop into anticancer drugs. Recently, a team of researchers identified some small molecules that could inactivate two closely related proteins called CDK8 and CDK19. CDK8 is essential for the WNT signaling pathway – which enables cells to communicate with one another – and has been extensively studied in various cancers. Previous studies indicate that this protein can either promote or inhibit the growth of tumors, depending on the type and stage of the cancer. Furthermore, CDK8 regulates a type of molecular switch called a “super-enhancer”, which controls the activity of many genes. In contrast, the role of CDK19 in cells was not as well understood. Here Clarke, Ortiz-Ruiz et al. investigated whether two different classes of small molecules that target CDK8 and CDK19 (referred to as “prototype CDK8/19 drugs”) could inhibit the growth of cancers, and whether they have any harmful side effects on healthy cells. For the experiments, human cancer cells were implanted into mice. Treating these mice with prototype CDK8/19 drugs inhibited the activity of CDK8 and CDK19 in the cancer cells and slowed the growth of colorectal tumors. A type of blood cancer called acute myeloid leukaemia was particularly sensitive to the drugs. However, Clarke, Ortiz-Ruiz et al. also observed that the prototype drugs altered the activity of many genes with roles in healthy tissues such as immune, bone and stem cells. Further experiments in mice and cells grown in the laboratory confirmed that these prototype drugs have adverse effects on healthy intestinal and bone marrow stem cells and trigger changes to immune cells. These concerning side effects were also evident when the prototype drugs were tested in rats and dogs. Furthermore, the experiments indicate that there is not a suitable range of doses of these drugs in which the therapeutic benefits outweigh the toxic side effects. Clarke, Ortiz-Ruiz et al. conclude that the clinical development of CDK8/19 drugs will be extremely challenging and that their prototype drugs would not currently be suitable for use as cancer treatments. However, the small molecules they describe will be important probes in research to study exactly how CDK8/19 regulate gene activity in both healthy cells and cancers.
Journal Article
M'DONALD WINS AFTER EARLY LOSS
1931
LONDON, Jan. 21.--(AP)-- Prime Minister Ramsay MacDonald's labor government was defeated by 23 votes in a division on the controversial education bill in the house of commons to night, but some hours later carried the bill victoriously through third reading by 256 voted against 238--a...
Newspaper Article
AMERICAN RADIO LAUDED
1927
\"This is London calling the British Isles. Here is the weather forecast.\" The best-known voice in England comes through 2,000,000 radio receiving seats. Uncle Rex, chief announcer of 3LO, is beginning his evening duty. He reads the weather forecast and the first general news bulletin to the
Newspaper Article
Retinal genes are differentially expressed in areas of primary versus secondary degeneration following partial optic nerve injury
by
Melton, Phillip E.
,
LeVaillant, Chrisna J.
,
Bartlett, Carole A.
in
Activating transcription factor 3
,
Apoptosis
,
Axons
2018
Partial transection (PT) of the optic nerve is an established experimental model of secondary degeneration in the central nervous system. After a dorsal transection, retinal ganglion cells (RGCs) with axons in ventral optic nerve are intact but vulnerable to secondary degeneration, whereas RGCs in dorsal retina with dorsal axons are affected by primary and secondary injuries. Using microarray, we quantified gene expression changes in dorsal and ventral retina at 1 and 7 days post PT, to characterize pathogenic pathways linked to primary and secondary degeneration.
In comparison to uninjured retina Cryba1, Cryba2 and Crygs, were significantly downregulated in injured dorsal retina at days 1 and 7. While Ecel1, Timp1, Mt2A and CD74, which are associated with reducing excitotoxicity, oxidative stress and inflammation, were significantly upregulated. Genes associated with oxygen binding pathways, immune responses, cytokine receptor activity and apoptosis were enriched in dorsal retina at day 1 after PT. Oxygen binding and apoptosis remained enriched at day 7, as were pathways involved in extracellular matrix modification. Fewer changes were observed in ventral retina at day 1 after PT, most associated with the regulation of protein homodimerization activity. By day 7, apoptosis, matrix organization and signal transduction pathways were enriched. Discriminant analysis was also performed for specific functional gene groups to compare expression intensities at each time point. Altered expression of selected genes (ATF3, GFAP, Ecel1, TIMP1, Tp53) and proteins (GFAP, ECEL1 and ATF3) were semi-quantitatively assessed by qRT-PCR and immunohistochemistry respectively.
There was an acute and complex primary injury response in dorsal retina indicative of a dynamic interaction between neuroprotective and neurodegenerative events; ventral retina vulnerable to secondary degeneration showed a delayed injury response. Both primary and secondary injury resulted in the upregulation of numerous genes linked to RGC death, but differences in the nature of these changes strongly suggest that death occurred via different molecular mechanisms.
Journal Article
Meta-analysis of human methylation data for evidence of sex-specific autosomal patterns
by
Moses, Eric K
,
Yazar, Seyhan
,
McCarthy, Nina S
in
Analysis
,
Animal Genetics and Genomics
,
Biomedical and Life Sciences
2014
Background
Several individual studies have suggested that autosomal CpG methylation differs by sex both in terms of individual CpG sites and global autosomal CpG methylation. However, these findings have been inconsistent and plagued by spurious associations due to the cross reactivity of CpG probes on commercial microarrays. We collectively analysed 76 published studies (n = 6,795) for sex-associated differences in both autosomal and sex chromosome CpG sites.
Results
Overall autosomal methylation profiles varied substantially by study, and we encountered substantial batch effects. We accounted for these by conducting random effects meta-analysis for individual autosomal CpG methylation associations. After excluding non-specific probes, we found 184 autosomal CpG sites differentially methylated by sex after correction for multiple testing. In line with previous studies, average beta differences were small. Many of the most significantly associated CpG probes were new. Of note was differential CpG methylation in the promoters of genes thought to be involved in spermatogenesis and male fertility, such as
SLC9A2
,
SPESP1
,
CRISP2
, and
NUPL1
. Pathway analysis revealed overrepresentation of genes differentially methylated by sex in several broad Gene Ontology biological processes, including RNA splicing and DNA repair.
Conclusions
This study represents a comprehensive analysis of sex-specific methylation patterns. We demonstrate the existence of sex-specific methylation profiles and report a large number of novel DNA methylation differences in autosomal CpG sites between sexes.
Journal Article
Fosfomycin for Treatment of Prostatitis: New Tricks for Old Dogs
by
Grayson, M. Lindsay
,
Hewitt, Nicholas H.
,
Zeglinski, Phillip T.
in
Aged
,
Aged, 80 and over
,
Anti-Bacterial Agents - administration & dosage
2015
Treatment options for prostatitis caused by multidrug-resistant gram-negative bacilli are limited. We report two cases cured with oral fosfomycin and provide a pharmacokinetic analysis of fosfomycin predose concentrations during treatment.
Journal Article
Surgery versus cast immobilisation for adults with a bicortical fracture of the scaphoid waist (SWIFFT): a pragmatic, multicentre, open-label, randomised superiority trial
2020
Scaphoid fractures account for 90% of carpal fractures and occur predominantly in young men. The use of immediate surgical fixation to manage this type of fracture has increased, despite insufficient evidence of improved outcomes over non-surgical management. The SWIFFT trial compared the clinical effectiveness of surgical fixation with cast immobilisation and early fixation of fractures that fail to unite in adults with scaphoid waist fractures displaced by 2 mm or less.
This pragmatic, parallel-group, multicentre, open-label, two-arm, randomised superiority trial included adults (aged 16 years or older) who presented to orthopaedic departments of 31 hospitals in England and Wales with a clear bicortical fracture of the scaphoid waist on radiographs. An independent remote randomisation service used a computer-generated allocation sequence with randomly varying block sizes to randomly assign participants (1:1) to receive either early surgical fixation (surgery group) or below-elbow cast immobilisation followed by immediate fixation if non-union of the fracture was confirmed (cast immobilisation group). Randomisation was stratified by whether or not there was displacement of either a step or a gap of 1–2 mm inclusive on any radiographic view. The primary outcome was the total patient-rated wrist evaluation (PRWE) score at 52 weeks after randomisation, and it was analysed on an available case intention-to-treat basis. This trial is registered with the ISRCTN registry, ISRCTN67901257, and is no longer recruiting, but long-term follow-up is ongoing.
Between July 23, 2013, and July 26, 2016, 439 (42%) of 1047 assessed patients (mean age 33 years; 363 [83%] men) were randomly assigned to the surgery group (n=219) or to the cast immobilisation group (n=220). Of these, 408 (93%) participants were included in the primary analysis (203 participants in the surgery group and 205 participants in the cast immobilisation group). 16 participants in the surgery group and 15 participants in the cast immobilisation group were excluded because of either withdrawal, no response, or no follow-up data at 6, 12, 26, or 52 weeks. There was no significant difference in mean PRWE scores at 52 weeks between the surgery group (adjusted mean 11·9 [95% CI 9·2–14·5]) and the cast immobilisation group (14·0 [11·3 to 16·6]; adjusted mean difference −2·1 [95% CI −5·8 to 1·6], p=0·27). More participants in the surgery group (31 [14%] of 219 participants) had a potentially serious complication from surgery than in the cast immobilisation group (three [1%] of 220 participants), but fewer participants in the surgery group (five [2%]) had cast-related complications than in the cast immobilisation group (40 [18%]). The number of participants who had a medical complication was similar between the two groups (four [2%] in the surgery group and five [2%] in the cast immobilisation group).
Adult patients with scaphoid waist fractures displaced by 2 mm or less should have initial cast immobilisation, and any suspected non-unions should be confirmed and immediately fixed with surgery. This treatment strategy will help to avoid the risks of surgery and mostly limit the use of surgery to fixing fractures that fail to unite.
National Institute for Health Research Health Technology Assessment Programme.
Journal Article
Retrospective Analysis of Pneumonic Tularemia in Operation Whitecoat Human Subjects: Disease Progression and Tetracycline Efficacy
by
Baker, Marianne R.
,
Pittman, Phillip R.
,
Lanning, Lynda
in
Antibiotics
,
Conscientious objectors
,
Data collection
2019
is a highly infectious Gram-negative bacterium that is the etiologic agent of tularemia in animals and humans. The incidence of tularemia is very low with a lack of comprehensive data that describe disease in humans due to difficulty in understanding time and routes of exposure. Under the title Operation Whitecoat, researchers at Ft. Detrick, MD conducted 40 clinical studies of tularemia from 1958 to 1968. In these studies, one of the objectives was to evaluate candidate countermeasures for treatment or prophylaxis of disease after exposure to
strain Schu S4 by inhalation. These studies were reviewed retrospectively to delineate the early signs and symptoms or natural history of pneumonic tularemia and examine the efficacy of tetracycline in controlled human clinical studies. Using vital signs, onset of fever was objectively defined and calculated for each subject, while Adverse Events reported after exposure were also used to define the timing of disease onset and symptoms of early disease. There was a dose response relationship between time to fever onset and exposed dose at 200 cfu (172.8 h), 700 cfu (163.2 h), 2,500 cfu (105.3 h), and 25,000 cfu (75.5 h). Onset of fever was typically the earliest sign of disease at all doses but was often accompanied by symptoms such as headache, myalgia, chest pain, and nausea, irrespective of dose except at 200 cfu where only 50% of subjects exhibited fever onset or symptoms. Examining the efficacy of different treatment regimens of tetracycline, ineffective treatments were indicated by relapse of disease (fever and Adverse Events) after cessation of antibiotic treatment. Stratification of the data suggested that treatment for <14 days or doses <2g/day was associated with increased percentage of subjects with relapse of disease symptoms. Although these types of human challenge studies would not be ethically possible now, the climate post-World War II supported human testing under rigorous conditions with informed consent. Thus, going back and analyzing these unique clinical human challenge studies has helped describe the course of infection and disease induced by a biothreat pathogen and possible countermeasures for treatment under controlled conditions.
Journal Article
A prime-boost concept using a T-cell epitope-driven DNA vaccine followed by a whole virus vaccine effectively protected pigs in the pandemic H1N1 pig challenge model
by
Gauger, Phillip
,
Hewitt, Joshua S.
,
De Groot, Anne S.
in
Allergy and Immunology
,
Antigens
,
control methods
2019
Influenza A virus (IAV) vaccines in pigs generally provide homosubtypic protection but fail to prevent heterologous infections. In this pilot study, the efficacy of an intradermal pDNA vaccine composed of conserved SLA class I and class II T cell epitopes (EPITOPE) against a homosubtypic challenge was compared to an intramuscular commercial inactivated whole virus vaccine (INACT) and a heterologous prime boost approach using both vaccines. Thirty-nine IAV-free, 3-week-old pigs were randomly assigned to one of five groups including NEG-CONTROL (unvaccinated, sham-challenged), INACT-INACT-IAV (vaccinated with FluSure XP® at 4 and 7 weeks, pH1N1 challenged), EPITOPE-INACT-IAV (vaccinated with PigMatrix EDV at 4 and FluSure XP® at 7 weeks, pH1N1 challenged), EPITOPE-EPITOPE-IAV (vaccinated with PigMatrix EDV at 4 and 7 weeks, pH1N1 challenged), and a POS-CONTROL group (unvaccinated, pH1N1 challenged). The challenge was done at 9 weeks of age and pigs were necropsied at day post challenge (dpc) 5. At the time of challenge, all INACT-INACT-IAV pigs, and by dpc 5 all EPITOPE-INACT-IAV pigs were IAV seropositive. IFNγ secreting cells, recognizing vaccine epitope-specific peptides and pH1N1 challenge virus were highest in the EPITOPE-INACT-IAV pigs at challenge. Macroscopic lung lesion scores were reduced in all EPITOPE-INACT-IAV pigs while INACT-INACT-IAV pigs exhibited a bimodal distribution of low and high scores akin to naïve challenged animals. No IAV antigen in lung tissues was detected at necropsy in the EPITOPE-INACT-IAV group, which was similar to naïve unchallenged pigs and different from all other challenged groups. Results suggest that the heterologous prime boost approach using an epitope-driven DNA vaccine followed by an inactivated vaccine was effective against a homosubtypic challenge, and further exploration of this vaccine approach as a practical control measure against heterosubtypic IAV infections is warranted.
Journal Article