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result(s) for
"Hopkins, Peter MA"
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Airway Telomere Length in Lung Transplant Recipients
2021
Chronic lung allograft dysfunction (CLAD) represents the major impediment to long term survival following lung transplantation. Donor and recipient telomere length have been shown to associate with lung transplant outcomes, including CLAD. In this study we aimed to measure the telomere lengths of bronchial and bronchiolar airway cells in lung allografts early after transplantation and to investigate associations with CLAD and all-cause mortality.
This prospective, longitudinal study was performed at The Prince Charles Hospital, Australia. Airway cells were collected
bronchial and bronchiolar airway brushings at post-transplant bronchoscopies. The relative telomere length in airway cells was determined by quantitative PCR based on the T/S ratio. All patients were censored for CLAD and all-cause mortality in August 2020.
In total 231 bronchoscopies incorporating transbronchial brush and bronchial brush were performed in 120 patients. At the time of censoring, 43% and 35% of patients, respectively, had developed CLAD and had died. Airway bronchiolar and bronchial telomere lengths were strongly correlated (r=0.78, p<0.001), confirming conservation of telomere length with airway branch generation. Both the bronchiolar (r = -0.34, p<0.001) and bronchial (r = -0.31, p<0.001) telomere length decreased with age. Shorter airway telomere length was associated with older donor age and higher donor pack-year smoking history. Neither the bronchiolar nor the bronchial airway telomere length were associated with the development of CLAD (HR 0.39 (0.06-2.3), p=0.30; HR 0.66 (0.2-1.7), p=0.39, respectively) or all-cause mortality (HR 0.92 (0.2-4.5), p=0.92; HR 0.47 (0.1-1.9), p=0.28, respectively).
In this cohort, airway telomere length was associated with donor age and smoking history but was not associated with the future development of CLAD or all-cause mortality.
Journal Article
An atlas of substrate specificities for the human serine/threonine kinome
2023
Protein phosphorylation is one of the most widespread post-translational modifications in biology
1
,
2
. With advances in mass-spectrometry-based phosphoproteomics, 90,000 sites of serine and threonine phosphorylation have so far been identified, and several thousand have been associated with human diseases and biological processes
3
,
4
. For the vast majority of phosphorylation events, it is not yet known which of the more than 300 protein serine/threonine (Ser/Thr) kinases encoded in the human genome are responsible
3
. Here we used synthetic peptide libraries to profile the substrate sequence specificity of 303 Ser/Thr kinases, comprising more than 84% of those predicted to be active in humans. Viewed in its entirety, the substrate specificity of the kinome was substantially more diverse than expected and was driven extensively by negative selectivity. We used our kinome-wide dataset to computationally annotate and identify the kinases capable of phosphorylating every reported phosphorylation site in the human Ser/Thr phosphoproteome. For the small minority of phosphosites for which the putative protein kinases involved have been previously reported, our predictions were in excellent agreement. When this approach was applied to examine the signalling response of tissues and cell lines to hormones, growth factors, targeted inhibitors and environmental or genetic perturbations, it revealed unexpected insights into pathway complexity and compensation. Overall, these studies reveal the intrinsic substrate specificity of the human Ser/Thr kinome, illuminate cellular signalling responses and provide a resource to link phosphorylation events to biological pathways.
Analysis of the kinase activity of 300 protein Ser/Thr kinases reveals that the substrate specificity of the kinome is substantially more diverse than expected and is driven extensively by negative selectivity
Journal Article
Benefits and harm of systemic steroids for short- and long-term use in rhinitis and rhinosinusitis: an EAACI position paper
2020
Because of the inflammatory mechanisms of most chronic upper airway diseases such as rhinitis and chronic rhinosinusitis, systemic steroids have been used for their treatment for decades. However, it has been very well documented that—potentially severe—side-effects can occur with the accumulation of systemic steroid courses over the years. A consensus document summarizing the benefits of systemic steroids for each upper airway disease type, as well as highlighting the potential harms of this treatment is currently lacking. Therefore, a panel of international experts in the field of Rhinology reviewed the available literature with the aim of providing recommendations for the use of systemic steroids in treating upper airway disease.
Journal Article
Intestinal Parasite Prevalence in an Area of Ethiopia after Implementing the SAFE Strategy, Enhanced Outreach Services, and Health Extension Program
by
Hopkins, Donald R.
,
Utzinger, Jürg
,
Ngondi, Jeremiah
in
Adolescent
,
Animals
,
Care and treatment
2013
The SAFE strategy aims to reduce transmission of Chlamydia trachomatis through antibiotics, improved hygiene, and sanitation. We integrated assessment of intestinal parasites into large-scale trachoma impact surveys to determine whether documented environmental improvements promoted by a trachoma program had collateral impact on intestinal parasites.
We surveyed 99 communities for both trachoma and intestinal parasites (soil-transmitted helminths, Schistosoma mansoni, and intestinal protozoa) in South Gondar, Ethiopia. One child aged 2-15 years per household was randomly selected to provide a stool sample of which about 1 g was fixed in sodium acetate-acetic acid-formalin, concentrated with ether, and examined under a microscope by experienced laboratory technicians.
A total of 2,338 stool specimens were provided, processed, and linked to survey data from 2,657 randomly selected children (88% response). The zonal-level prevalence of Ascaris lumbricoides, hookworm, and Trichuris trichiura was 9.9% (95% confidence interval (CI) 7.2-12.7%), 9.7% (5.9-13.4%), and 2.6% (1.6-3.7%), respectively. The prevalence of S. mansoni was 2.9% (95% CI 0.2-5.5%) but infection was highly focal (range by community from 0-52.4%). The prevalence of any of these helminth infections was 24.2% (95% CI 17.6-30.9%) compared to 48.5% as found in a previous study in 1995 using the Kato-Katz technique. The pathogenic intestinal protozoa Giardia intestinalis and Entamoeba histolytica/E. dispar were found in 23.0% (95% CI 20.3-25.6%) and 11.1% (95% CI 8.9-13.2%) of the surveyed children, respectively. We found statistically significant increases in household latrine ownership, use of an improved water source, access to water, and face washing behavior over the past 7 years.
Improvements in hygiene and sanitation promoted both by the SAFE strategy for trachoma and health extension program combined with preventive chemotherapy during enhanced outreach services are plausible explanations for the changing patterns of intestinal parasite prevalence. The extent of intestinal protozoa infections suggests poor water quality or unsanitary water collection and storage practices and warrants targeted intervention.
Journal Article
Mapping EQ5D utilities from forced vital capacity and diffusing capacity in fibrotic interstitial lung disease
by
Cox, Ingrid A.
,
Navaratnam, Vidya
,
Fisher, Jolene H.
in
Algorithms
,
Australia
,
Biology and Life Sciences
2023
Fibrotic interstitial lung disease (ILD) includes a large group of conditions that lead to scarring of the lungs. The lack of available 5-level EuroQol 5D (EQ5D) data has limited the ability to conduct economic evaluations in ILD. The purpose of this study was to develop and validate a mapping algorithm that predicts EQ5D utilities from commonly collected pulmonary function measurements (forced vital capacity [FVC] and diffusing capacity of the lung for carbon monoxide [DLCO]) in fibrotic ILDs.
EQ5D utility and pulmonary function measurements from the Canadian Registry for Pulmonary Fibrosis were included. Ordinary least squares (OLS), beta regression, two-part, and tobit models were used to map EQ5D utilities from FVC or DLCO. Model performance was assessed by comparing the predicted and observed utilities. Subgroup analyses were also conducted to test how well models performed across different patient characteristics. The models were then externally validated in the Australian Idiopathic Pulmonary Fibrosis Registry.
The OLS model performed as well as other more complex models (root mean squared error: 0.17 for FVC and 0.16 for DLCO). As with the other models, the OLS algorithm performed well across the different subgroups (except for EQ5D utilities < 0.5) and in the external validation cohort.
We developed a mapping algorithm that predicts EQ5D utilities from FVC and DLCO, with the intent that this algorithm can be applied to clinical trial populations and real-world cohorts that have not prioritized collection of health-related utilities. The mapping algorithm can be used in future economic evaluations of potential ILD therapies.
Journal Article
Health-Related Quality of Life Impairment Among Patients with Severe Chronic Rhinosinusitis with Nasal Polyps in the SINUS-24 Trial
2023
Chronic rhinosinusitis with nasal polyps (CRSwNP) is a predominantly type 2 inflammatory disease with a high symptom burden. Data are lacking on the comparative health status of patients with CRSwNP. This analysis compared baseline physical and mental health-related quality of life (HRQoL) and overall health status of patients with severe CRSwNP enrolled in a Phase 3 clinical trial with general population norms and with other chronic diseases.
In this post hoc cross-sectional analysis of baseline data from the SINUS-24 study (NCT02912468), HRQoL was measured using the 36-item Short Form (SF-36) questionnaire and general health status was measured using the EuroQol-5 Dimension visual analog scale (EQ-VAS). Analyses included the intention-to-treat (ITT) population and subgroups defined by prior sinonasal surgery, systemic corticosteroid use, and coexisting asthma or non-steroidal anti-inflammatory drug-exacerbated respiratory disease (NSAID-ERD). Scores were compared with published values for population norms (50 for SF-36 physical component summary (PCS) and mental component summary (MCS), 70.4-83.3 for EQ-VAS) and for rheumatoid arthritis, type 2 diabetes, and asthma.
In the ITT population (n=276), mean SF-36 physical component summary (PCS), SF-36 mental component summary (MCS), and EQ-VAS scores were below general population norms (46.4, 48.6, and 66.0, respectively). Mean SF-36 PCS and EQ-VAS scores were below population norms across all subgroups; mean SF-36 MCS scores were below the population norm in all subgroups except no prior surgery. SF-36 PCS and MCS scores from SINUS-24 were generally similar to other chronic diseases, except SF-36 PCS which was lower in rheumatoid arthritis. EQ-VAS scores in SINUS-24 were lower than in other chronic diseases. HRQoL scores weakly correlated with objective measures of disease severity.
In patients with severe CRSwNP, including those with coexisting asthma/NSAID-ERD, HRQoL was worse than population norms and as burdensome as diseases such as type 2 diabetes, asthma, and rheumatoid arthritis.
Journal Article
Invitation methods for Indigenous New Zealand Māori in lung cancer screening: Protocol for a pragmatic cluster randomized controlled trial
by
Parker, Kate
,
Crengle, Sue
,
Brown, Rachel
in
Biology and Life Sciences
,
Cancer
,
Cancer screening
2023
Lung cancer screening can significantly reduce mortality from lung cancer. Further evidence about how to optimize lung cancer screening for specific populations, including Aotearoa New Zealand (NZ)’s Indigenous Māori (who experience disproportionately higher rates of lung cancer), is needed to ensure it is equitable. This community-based, pragmatic cluster randomized trial aims to determine whether a lung cancer screening invitation from a patient’s primary care physician, compared to from a centralized screening service, will optimize screening uptake for Māori. Participating primary care practices (clinics) in Auckland, Aotearoa NZ will be randomized to either the primary care-led or centralized service for delivery of the screening invitation. Clinic patients who meet the following criteria will be eligible: Māori; aged 55–74 years; enrolled in participating clinics in the region; ever-smokers; and have at least a 2% risk of developing lung cancer within six years (determined using the PLCO M2012 risk prediction model). Eligible patients who respond positively to the invitation will undertake shared decision-making with a nurse about undergoing a low dose CT scan (LDCT) and an assessment for Chronic Obstructive Pulmonary Disease (COPD). The primary outcomes are: 1) the proportion of eligible population who complete a risk assessment and 2) the proportion of people eligible for a CT scan who complete the CT scan. Secondary outcomes include evaluating the contextual factors needed to inform the screening process, such as including assessment for Chronic Obstructive Pulmonary Disease (COPD). We will also use the RE-AIM framework to evaluate specific implementation factors. This study is a world-first, Indigenous-led lung cancer screening trial for Māori participants. The study will provide policy-relevant information on a key policy parameter, invitation method. In addition, the trial includes a nested analysis of COPD in the screened Indigenous population, and it provides baseline (T0 screen round) data using RE-AIM implementation outcomes.
Journal Article
Association of Minimal Rejection in Lung Transplant Recipients with Obliterative Bronchiolitis
by
Plit, Marshall L
,
Hopkins, Peter M
,
Aboyoun, Christina L
in
Adolescent
,
Adult
,
Age Distribution
2004
The clinical significance of minimal acute rejection (grade A1) in lung transplant recipients is unknown. We prospectively analyzed 1,159 transbronchial lung biopsies in 184 patients. Two hundred seventy-nine biopsies in 128 participants confirmed A1 histology at a mean postoperative day of 229 +/- 340. Sixty four of 255 surveillance A1 lesions progressed to high-grade acute rejection by 3 months of follow-up, whereas 40 developed new lymphocytic bronchiolitis. Twenty-four A1 biopsies were symptomatic, with only two cases progressing to high-grade rejection after steroid therapy. Seventy-eight of 184 patients experienced multiple (> or = 2) A1 biopsies in the first 12 months after transplant. Bronchiolitis obliterans syndrome developed in 68% of patients with multiple A1 lesions at a mean of 599 +/- 435 days, compared with 43% of patients with one or less A1 lesions at a mean of 819 +/- 526 (p = 0.022). Eighteen patients experienced multiple A1 biopsies after transplant in the absence of high-grade rejection episodes yet also developed earlier obliterative bronchiolitis (456 +/- 245 days, p = 0.020). We conclude that for A1 transbronchial lung biopsies, the conventional treatment of observation only is now challenged even in patients who are asymptomatic. Patients who experience multiple A1 lesions develop an earlier onset of obliterative bronchiolitis and may warrant alternative immunosuppressive strategies.
Journal Article
Identification of a new gene mutated in Fraser syndrome and mouse myelencephalic blebs
by
Hopkins, Jason
,
Jackson, Ian
,
van Haelst, Mieke
in
Agriculture
,
Amino acids
,
Animal Genetics and Genomics
2005
Fraser syndrome is a recessive, multisystem disorder presenting with cryptophthalmos, syndactyly and renal defects
1
,
2
and associated with loss-of-function mutations of the extracellular matrix protein FRAS1.
Fras1
mutant mice have a blebbed phenotype characterized by intrauterine epithelial fragility generating serous and, later, hemorrhagic blisters. The myelencephalic blebs (
my
) strain has a similar phenotype. We mapped
my
to
Frem2
, a gene related to
Fras1
and
Frem1
, and showed that a
Frem2
gene-trap mutation was allelic to
my
. Expression of
Frem2
in adult kidneys correlated with cyst formation in
my
homozygotes, indicating that the gene is required for maintaining the differentiated state of renal epithelia. Two individuals with Fraser syndrome were homozygous with respect to the same missense mutation of
FREM2
, confirming genetic heterogeneity. This is the only missense mutation reported in any blebbing mutant or individual with Fraser syndrome, suggesting that calcium binding in the CALXβ-cadherin motif is important for normal functioning of
FREM2
.
Journal Article
Management of Thromboembolic Complications During Aneurysm Coiling: 2-Dimensional Operative Video
by
Martinez Santos, Jaime L
,
Domingo, Ricardo A
,
Tawk, Rabih G
in
Aneurysm, Ruptured - complications
,
Aneurysm, Ruptured - diagnostic imaging
,
Aneurysm, Ruptured - surgery
2021
Abstract
Thromboembolic complications during aneurysm coiling are rare, with higher rates noted in ruptured aneurysms as patients are not usually premedicated with dual antiplatelet therapy.1,2 Management includes a series of escalating strategies, including medical therapy and intra-arterial thrombolysis.3-6 Additional strategies include mechanical thrombectomy with suction aspiration and stent retrievers.3 Intracranial stenting can be used as a last resource, especially in ruptured cases given the need for dual antiplatelets to prevent stent thrombosis.2
We present the case of a 42-yr-old man with a ruptured left internal carotid artery aneurysm with associated intracranial and intraventricular hemorrhage. The patient was initially presented to an outside facility after he was found in bed unable to speak and with right hemiparesis. The patient consented for surgery and underwent external ventricular drain (EVD) placement for the treatment of obstructive hydrocephalus, followed by diagnostic cerebral angiogram and aneurysm coiling. After the deployment of the last coil, control angiogram showed a small filling defect at the interface between the aneurysm neck and the distal vessel. The patient received intravenous heparin for therapeutic ACT and aspirin load. After progressive enlargement of the thrombus, the patient received intra-arterial glycoprotein (GP) IIB/IIIA inhibitors with a microcatheter positioned proximal to the thrombus. As the thrombus mass continued to enlarge, mechanical thrombectomy with an aspiration catheter was performed twice. Follow-up angiogram 20 min after the second aspiration demonstrated near-complete resolution of the thrombus. The patient recovered from his right hemiparesis, and he was discharged to rehabilitation on POD #21.
Journal Article