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1.
Gastroenterol Rep (Oxf) ; 11: goad008, 2023.
Article in English | MEDLINE | ID: mdl-37082451

ABSTRACT

Background: The purpose of this study was to review the current management of gastro-oesophageal reflux disease (GORD), including treatment costs, safety profile and effectiveness. Methods: A literature review was performed of randomized-controlled trials, systematic reviews, Cochrane reports and National/Societal guidelines of the medical, endoscopic and surgical management of GORD. Proton pump inhibitor (PPI) prescribing patterns and expenditure were reviewed in different countries, including Australia, Canada, New Zealand, UK and USA. Results: Proton pump inhibitors (PPIs) are primarily indicated for control of GORD, Helicobacter pylori eradication (combined with antibiotics), preventing NSAID-induced gastrointestinal bleeding and treating peptic ulcer disease. There is widespread overprescribing of PPIs in Western and Eastern nations in terms of indication and duration, with substantial expense for national health providers. Despite a favourable short-term safety profile, there are observational associations of adverse effects with long-term PPIs. These include nutrient malabsorption, enteric infections and cardiovascular events. The prevalence of PPI use makes their long-term safety profile clinically relevant. Cost-benefit, symptom control and quality-of-life outcomes favour laparoscopic fundoplication rather than chronic PPI treatment. Laparoscopic fundoplication in long-term management of PPI-responsive GORD is supported by SAGES, NICE and ACG, and PPI-refractory GORD by AGA and SAGES guidelines. The importance of establishing a definitive diagnosis prior to invasive management is emphasized, especially in PPI-refractory heartburn. Conclusions: We examined evidence-based guidelines for PPI prescribing and deprescribing in primary care and hospital settings and the need for PPI stewardship and education of health professionals. This narrative review presents the advantages and disadvantages of surgical, endoscopic and medical management of GORD, which may assist in shared decision making and treatment choice in individual patients.This paper was presented (GS020) at the 88th RACS Annual Scientific Conference, 6-10 May, 2019.

2.
Int J Mol Sci ; 24(7)2023 Mar 24.
Article in English | MEDLINE | ID: mdl-37047163

ABSTRACT

The study aimed to perform a systematic review and meta-analysis of the evidence for the prevention of future cancers following bariatric surgery. A systematic literature search of the Cochrane Library, Embase, Scopus, Web of Science and PubMed databases (2007-2023), Google Scholar and grey literature was conducted. A meta-analysis was performed using the inverse variance method and random effects model. Thirty-two studies involving patients with obesity who received bariatric surgery and control patients who were managed with conventional treatment were included. The meta-analysis suggested bariatric surgery was associated with a reduced overall incidence of cancer (RR 0.62, 95% CI 0.46-0.84, p < 0.002), obesity-related cancer (RR 0.59, 95% CI 0.39-0.90, p = 0.01) and cancer-associated mortality (RR 0.51, 95% CI 0.42-0.62, p < 0.00001). In specific cancers, bariatric surgery was associated with reduction in the future incidence of hepatocellular carcinoma (RR 0.35, 95% CI 0.22-0.55, p < 0.00001), colorectal cancer (RR 0.63, CI 0.50-0.81, p = 0.0002), pancreatic cancer (RR 0.52, 95% CI 0.29-0.93, p = 0.03) and gallbladder cancer (RR 0.41, 95% CI 0.18-0.96, p = 0.04), as well as female specific cancers, including breast cancer (RR 0.56, 95% CI 0.44-0.71, p < 0.00001), endometrial cancer (RR 0.38, 95% CI 0.26-0.55, p < 0.00001) and ovarian cancer (RR 0.45, 95% CI 0.31-0.64, p < 0.0001). There was no significant reduction in the incidence of oesophageal, gastric, thyroid, kidney, prostate cancer or multiple myeloma after bariatric surgery as compared to patients with morbid obesity who did not have bariatric surgery. Obesity-associated carcinogenesis is closely related to metabolic syndrome; visceral adipose dysfunction; aromatase activity and detrimental cytokine, adipokine and exosomal miRNA release. Bariatric surgery results in long-term weight loss in morbidly obese patients and improves metabolic syndrome. Bariatric surgery may decrease future overall cancer incidence and mortality, including the incidence of seven obesity-related cancers.


Subject(s)
Bariatric Surgery , Metabolic Syndrome , Neoplasms , Obesity, Morbid , Male , Humans , Female , Obesity, Morbid/complications , Obesity, Morbid/surgery , Metabolic Syndrome/complications , Risk , Incidence , Neoplasms/etiology , Neoplasms/complications
3.
Mov Disord ; 38(6): 970-977, 2023 06.
Article in English | MEDLINE | ID: mdl-36928898

ABSTRACT

BACKGROUND: Friedreich's ataxia (FRDA), most commonly caused by a GAA triplet repeat (GAA-TR) expansion in intron 1 of the FXN gene, is characterized by deficiency of frataxin protein and clinical features such as progressive ataxia, dysarthria, impaired proprioception and vibration, abolished deep tendon reflexes, Babinski sign, and vision loss in association with non-neurological features such as skeletal anomalies, hearing loss, cardiomyopathy, and diabetes. Pathogenic GAA-TRs range in size from 60 to 1500 triplets and negatively correlate with age of onset. Clinical severity is predicted by a combination of GAA-TR length and disease duration (DD) via multivariable regressions, which cannot typically be used for the small sample sizes in most studies on this rare disease. OBJECTIVE: We aimed to develop a single metric, which we call "disease burden" (DB), that encompasses both GAA-TR length and DD for predicting disease features of FRDA in small sample sizes. METHODS: Linear regression and multivariable regression analysis was used to determine correlation coefficients between different disease features of FRDA. RESULTS: Using large datasets for validation, we found that DB predicts measures of neurological dysfunction in FRDA better than GAA-TR length or DD. Analogous results were found using small datasets. CONCLUSIONS: FRDA DB is a novel metric of disease severity that has utility in small datasets to demonstrate correlations that would not otherwise be evident with either GAA-TR or DD alone. This is important for discovering new biomarkers, as well as improving the prediction of severity of disease features in FRDA. © 2023 International Parkinson and Movement Disorder Society.


Subject(s)
Friedreich Ataxia , Humans , Friedreich Ataxia/genetics , Trinucleotide Repeats , Trinucleotide Repeat Expansion/genetics , Introns , Severity of Illness Index , Iron-Binding Proteins/genetics , Iron-Binding Proteins/metabolism
4.
Dis Model Mech ; 16(5)2023 05 01.
Article in English | MEDLINE | ID: mdl-36107856

ABSTRACT

Friedreich ataxia, the most common hereditary ataxia, is a neuro- and cardio-degenerative disorder caused, in most cases, by decreased expression of the mitochondrial protein frataxin. Cardiomyopathy is the leading cause of premature death. Frataxin functions in the biogenesis of iron-sulfur clusters, which are prosthetic groups that are found in proteins involved in many biological processes. To study the changes associated with decreased frataxin in human cardiomyocytes, we developed a novel isogenic model by acutely knocking down frataxin, post-differentiation, in cardiomyocytes derived from induced pluripotent stem cells (iPSCs). Transcriptome analysis of four biological replicates identified severe mitochondrial dysfunction and a type I interferon response as the pathways most affected by frataxin knockdown. We confirmed that, in iPSC-derived cardiomyocytes, loss of frataxin leads to mitochondrial dysfunction. The type I interferon response was activated in multiple cell types following acute frataxin knockdown and was caused, at least in part, by release of mitochondrial DNA into the cytosol, activating the cGAS-STING sensor pathway.


Subject(s)
Friedreich Ataxia , Induced Pluripotent Stem Cells , Interferon Type I , Humans , Induced Pluripotent Stem Cells/metabolism , Myocytes, Cardiac/metabolism , Interferon Type I/metabolism , Iron-Binding Proteins/genetics , Iron-Binding Proteins/metabolism , Friedreich Ataxia/genetics , Friedreich Ataxia/metabolism , Mitochondrial Proteins/metabolism , Iron/metabolism , DNA, Mitochondrial/metabolism , Nucleotidyltransferases/metabolism , Sulfur/metabolism , Frataxin
5.
J Lipid Res ; 63(9): 100255, 2022 09.
Article in English | MEDLINE | ID: mdl-35850241

ABSTRACT

Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disorder caused by a triplet guanine-adenine-adenine (GAA) repeat expansion in intron 1 of the FXN gene, which leads to decreased levels of the frataxin protein. Frataxin is involved in the formation of iron-sulfur (Fe-S) cluster prosthetic groups for various metabolic enzymes. To provide a better understanding of the metabolic status of patients with FRDA, here we used patient-derived fibroblast cells as a surrogate tissue for metabolic and lipidomic profiling by liquid chromatography-high resolution mass spectrometry. We found elevated HMG-CoA and ß-hydroxybutyrate-CoA levels, implying dysregulated fatty acid oxidation, which was further demonstrated by elevated acyl-carnitine levels. Lipidomic profiling identified dysregulated levels of several lipid classes in FRDA fibroblast cells when compared with non-FRDA fibroblast cells. For example, levels of several ceramides were significantly increased in FRDA fibroblast cells; these results positively correlated with the GAA repeat length and negatively correlated with the frataxin protein levels. Furthermore, stable isotope tracing experiments indicated increased ceramide synthesis, especially for long-chain fatty acid-ceramides, in FRDA fibroblast cells compared with ceramide synthesis in healthy control fibroblast cells. In addition, PUFA-containing triglycerides and phosphatidylglycerols were enriched in FRDA fibroblast cells and negatively correlated with frataxin levels, suggesting lipid remodeling as a result of FXN deficiency. Altogether, we demonstrate patient-derived fibroblast cells exhibited dysregulated metabolic capabilities, and their lipid dysfunction predicted the severity of FRDA, making them a useful surrogate to study the metabolic status in FRDA.


Subject(s)
Friedreich Ataxia , 3-Hydroxybutyric Acid , Adenine/metabolism , Carnitine/metabolism , Ceramides/metabolism , Coenzyme A/metabolism , Fibroblasts/metabolism , Friedreich Ataxia/genetics , Friedreich Ataxia/metabolism , Guanine/metabolism , Humans , Iron/metabolism , Phosphatidylglycerols , Sulfur/metabolism , Triglycerides/metabolism
6.
Front Physiol ; 13: 868578, 2022.
Article in English | MEDLINE | ID: mdl-35557972

ABSTRACT

Background: Long-chain polyunsaturated fatty acids (PUFAs) are important modulators of red blood cell (RBC) rheology. Dietary PUFAs are readily incorporated into the RBC membrane, improving RBC deformability, fluidity, and hydration. However, enriching the lipid membrane with PUFAs increases the potential for peroxidation in oxidative environments (e.g., refrigerated storage), resulting in membrane damage. Substitution of bis-allylic hydrogens with deuterium ions in PUFAs decreases hydrogen abstraction, thereby inhibiting peroxidation. If lipid peroxidation is a causal factor in the RBC storage lesion, incorporation of deuterated linoleic acid (DLA) into the RBC membrane should decrease lipid peroxidation, thereby improving RBC lifespan, deformability, filterability, and post-transfusion recovery (PTR) after cold storage. Study Design and Methods: Mice associated with good (C57BL/6J) and poor (FVB) RBC storage quality received diets containing 11,11-D2-LA Ethyl Ester (1.0 g/100 g diet; deuterated linoleic acid) or non-deuterated LA Ethyl Ester (control) for 8 weeks. Deformability, filterability, lipidomics, and lipid peroxidation markers were evaluated in fresh and stored RBCs. Results: DLA was incorporated into RBC membranes in both mouse strains. DLA diet decreased lipid peroxidation (malondialdehyde) by 25.4 and 31% percent in C57 mice and 12.9 and 79.9% in FVB mice before and after cold storage, respectively. In FVB, but not C57 mice, deformability filterability, and post-transfusion recovery were significantly improved. Discussion: In a mouse model of poor RBC storage, with elevated reactive oxygen species production, DLA attenuated lipid peroxidation and significantly improved RBC storage quality.

8.
Int J Mol Sci ; 21(17)2020 Sep 03.
Article in English | MEDLINE | ID: mdl-32899442

ABSTRACT

Helicobacter pylori is a class one carcinogen which causes chronic atrophic gastritis, gastric intestinal metaplasia, dysplasia and adenocarcinoma. The mechanisms by which H. pylori interacts with other risk and protective factors, particularly vitamin C in gastric carcinogenesis are complex. Gastric carcinogenesis includes metabolic, environmental, epigenetic, genomic, infective, inflammatory and oncogenic pathways. The molecular classification of gastric cancer subtypes has revolutionized the understanding of gastric carcinogenesis. This includes the tumour microenvironment, germline mutations, and the role of Helicobacter pylori bacteria, Epstein Barr virus and epigenetics in somatic mutations. There is evidence that ascorbic acid, phytochemicals and endogenous antioxidant systems can modify the risk of gastric cancer. Gastric juice ascorbate levels depend on dietary intake of ascorbic acid but can also be decreased by H. pylori infection, H. pylori CagA secretion, tobacco smoking, achlorhydria and chronic atrophic gastritis. Ascorbic acid may be protective against gastric cancer by its antioxidant effect in gastric cytoprotection, regenerating active vitamin E and glutathione, inhibiting endogenous N-nitrosation, reducing toxic effects of ingested nitrosodimethylamines and heterocyclic amines, and preventing H. pylori infection. The effectiveness of such cytoprotection is related to H. pylori strain virulence, particularly CagA expression. The role of vitamin C in epigenetic reprogramming in gastric cancer is still evolving. Other factors in conjunction with vitamin C also play a role in gastric carcinogenesis. Eradication of H. pylori may lead to recovery of vitamin C secretion by gastric epithelium and enable regression of premalignant gastric lesions, thereby interrupting the Correa cascade of gastric carcinogenesis.


Subject(s)
Ascorbic Acid/pharmacology , Carcinogenesis/drug effects , Helicobacter Infections/complications , Helicobacter pylori/isolation & purification , Phytochemicals/pharmacology , Stomach Neoplasms/prevention & control , Animals , Antioxidants/pharmacology , Carcinogenesis/metabolism , Carcinogenesis/pathology , Gastric Juice/metabolism , Helicobacter Infections/microbiology , Humans , Stomach Neoplasms/etiology , Stomach Neoplasms/metabolism , Stomach Neoplasms/pathology
9.
J Clin Pathol ; 2020 Aug 27.
Article in English | MEDLINE | ID: mdl-32855180

ABSTRACT

Cancer lineage/tissue-of-origin assignment in cancers of unknown primary remains a challenge even when aided by massively parallel sequencing. The stakes are high for patients as many contemporary therapeutic strategies are disease-specific, and the biological differences can influence the patients' responses. Herein, we provide an example of how Bayesian analysis can be used to merge data from clinical history, histology, immunohistochemistry (IHC) and cancer DNA sequencing to assist in tissue-of-origin assignment. Iterative Bayesian analysis is performed through a set of simple calculations to calculate the OR between the differential diagnoses. We illustrate a clinical case, where the distinction between a primary lung versus metastatic bladder cancer was aided meaningfully by iterative Bayesian analyses, incorporating IHC and sequencing data.

10.
ACS Chem Neurosci ; 11(17): 2535-2542, 2020 09 02.
Article in English | MEDLINE | ID: mdl-32786299

ABSTRACT

Friedreich ataxia (FRDA) is an inherited neurodegenerative disorder for which there is no cure or approved treatment. It is characterized by the loss or impaired activity of frataxin protein, which is involved in the biogenesis of iron-sulfur clusters. Our previous studies suggested that cell death in FRDA may involve ferroptosis, an iron-dependent form of cell death requiring lipid peroxidation. Based on reports that oleic acid acts as a ferroptosis inhibitor, we evaluated whether it, other fatty acids, and fatty acid derivatives could rescue viability in cellular models of FRDA. We identified a trifluoromethyl alcohol analog of oleic acid that was significantly more potent than oleic acid itself. Further evaluation indicated that the effects were stereoselective, although a specific molecular target has not yet been identified. This work provides a potential starting point for therapeutics to treat FRDA, as well as a valuable probe molecule to interrogate FRDA pathophysiology.


Subject(s)
Ferroptosis , Friedreich Ataxia , Friedreich Ataxia/drug therapy , Friedreich Ataxia/metabolism , Humans , Iron-Binding Proteins/metabolism , Lipid Peroxidation , Mitochondria/metabolism , Oleic Acid/metabolism , Oleic Acid/pharmacology
12.
Int J Mol Sci ; 21(11)2020 Jun 10.
Article in English | MEDLINE | ID: mdl-32532126

ABSTRACT

In chronic peritoneal diseases, mesothelial-mesenchymal transition is determined by cues from the extracellular environment rather than just the cellular genome. The transformation of peritoneal mesothelial cells and other host cells into myofibroblasts is mediated by cell membrane receptors, Transforming Growth Factor ß1 (TGF-ß1), Src and Hypoxia-inducible factor (HIF). This article provides a narrative review of the reprogramming of mesothelial mesenchymal transition in chronic peritoneal diseases, drawing on the similarities in pathophysiology between encapsulating peritoneal sclerosis and peritoneal metastasis, with a particular focus on TGF-ß1 signaling and estrogen receptor modulators. Estrogen receptors act at the cell membrane/cytosol as tyrosine kinases that can phosphorylate Src, in a similar way to other receptor tyrosine kinases; or can activate the estrogen response element via nuclear translocation. Tamoxifen can modulate estrogen membrane receptors, and has been shown to be a potent inhibitor of mesothelial-mesenchymal transition (MMT), peritoneal mesothelial cell migration, stromal fibrosis, and neoangiogenesis in the treatment of encapsulating peritoneal sclerosis, with a known side effect and safety profile. The ability of tamoxifen to inhibit the transduction pathways of TGF-ß1 and HIF and achieve a quiescent peritoneal stroma makes it a potential candidate for use in cancer treatments. This is relevant to tumors that spread to the peritoneum, particularly those with mesenchymal phenotypes, such as colorectal CMS4 and MSS/EMT gastric cancers, and pancreatic cancer with its desmoplastic stroma. Morphological changes observed during mesothelial mesenchymal transition can be treated with estrogen receptor modulation and TGF-ß1 inhibition, which may enable the regression of encapsulating peritoneal sclerosis and peritoneal metastasis.


Subject(s)
Epithelial-Mesenchymal Transition , Estrogen Receptor Modulators/pharmacology , Peritoneal Diseases/drug therapy , Peritoneal Diseases/pathology , Transforming Growth Factor beta1/antagonists & inhibitors , Animals , Cancer-Associated Fibroblasts/drug effects , Cancer-Associated Fibroblasts/metabolism , Cancer-Associated Fibroblasts/pathology , Chronic Disease , Epithelial Cells/drug effects , Fibroblasts/drug effects , Fibroblasts/pathology , Flavonoids/pharmacology , Glycolysis/drug effects , Glycolysis/physiology , Humans , NF-kappa B/metabolism , Peritoneal Diseases/metabolism , Peritoneal Fibrosis/drug therapy , Peritoneal Fibrosis/metabolism , Peritoneal Fibrosis/pathology , Peritoneum/cytology , Receptors, Estrogen/metabolism , Tamoxifen/therapeutic use , Transforming Growth Factor beta1/metabolism , Tumor Microenvironment/drug effects
13.
Int J Mol Sci ; 20(21)2019 Oct 31.
Article in English | MEDLINE | ID: mdl-31683709

ABSTRACT

: Patients with peritoneal metastasis (PM) of gastrointestinal and gynecological origin present with a nutritional deficit characterized by increased resting energy expenditure (REE), loss of muscle mass, and protein catabolism. Progression of peritoneal metastasis, as with other advanced malignancies, is associated with cancer cachexia anorexia syndrome (CAS), involving poor appetite (anorexia), involuntary weight loss, and chronic inflammation. Eventual causes of mortality include dysfunctional metabolism and energy store exhaustion. Etiology of CAS in PM patients is multifactorial including tumor growth, host response, cytokine release, systemic inflammation, proteolysis, lipolysis, malignant small bowel obstruction, ascites, and gastrointestinal side effects of drug therapy (chemotherapy, opioids). Metabolic changes of CAS in PM relate more to a systemic inflammatory response than an adaptation to starvation. Metabolic reprogramming is required for cancer cells shed into the peritoneal cavity to resist anoikis (i.e., programmed cell death). Profound changes in hexokinase metabolism are needed to compensate ineffective oxidative phosphorylation in mitochondria. During the development of PM, hypoxia inducible factor-1α (HIF-1α) plays a key role in activating both aerobic and anaerobic glycolysis, increasing the uptake of glucose, lipid, and glutamine into cancer cells. HIF-1α upregulates hexokinase II, phosphoglycerate kinase 1 (PGK1), pyruvate dehydrogenase kinase (PDK), pyruvate kinase muscle isoenzyme 2 (PKM2), lactate dehydrogenase (LDH) and glucose transporters (GLUT) and promotes cytoplasmic glycolysis. HIF-1α also stimulates the utilization of glutamine and fatty acids as alternative energy substrates. Cancer cells in the peritoneal cavity interact with cancer-associated fibroblasts and adipocytes to meet metabolic demands and incorporate autophagy products for growth. Therapy of CAS in PM is challenging. Optimal nutritional intake alone including total parenteral nutrition is unable to reverse CAS. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) stabilized nutritional status in a significant proportion of PM patients. Agents targeting the mechanisms of CAS are under development.


Subject(s)
Anorexia/metabolism , Cachexia/metabolism , Energy Metabolism , Gastrointestinal Neoplasms/metabolism , Mitochondria/metabolism , Peritoneal Neoplasms/metabolism , Gastrointestinal Neoplasms/pathology , Humans , Nutritional Status , Oxidative Phosphorylation , Peritoneal Neoplasms/secondary , Syndrome
14.
Pleura Peritoneum ; 4(1): 20190003, 2019 Mar 01.
Article in English | MEDLINE | ID: mdl-31198853

ABSTRACT

Detachment of cells from the extracellular matrix into the peritoneal cavity initiates a cascade of metabolic alterations, leading usually to cell death by apoptosis, so-called anoikis. Glycolytic enzymes enable the switch from oxidative phosphorylation to aerobic glycolysis and allow resistance to anoikis of shed tumour cells. These enzymes also have moonlighting activities as protein kinases and transcription factors. Phosphoglycerate kinase (PGK) and pyruvate kinase are the only glycolytic enzymes generating ATP in the hexokinase pathway. Hypoxia, EGFR activation, expression of K-Ras G12V and B-Raf V600E induce mitochondrial translocation of phosphoglycerate kinase 1 (PGK1). Mitochondrial PGK1 acts as a protein kinase to phosphorylate pyruvate dehydrogenase kinase 1 (PDHK1), reducing mitochondrial pyruvate utilization, suppressing reactive oxygen species production, increasing lactate production and promoting tumourigenesis. PGK1 also plays a role as a transcription factor once transported into the nucleus. Resistance to anoikis is also facilitated by metabolic support provided by cancer-associated fibroblasts (CAFs). Our series of experiments in-vitro and in the animal model showed that PGK1 knock-out or inhibition is effective in controlling development and growth of peritoneal metastasis (PM) of gastric origin, establishing a causal role of PGK1 in this development. PGK1 also increases CXCR4 and CXCL12 expression, which is associated with a metastatic phenotype and plays a role in the metastatic homing of malignant cells. Thus, PGK1, its modulators and target genes may be exploited as therapeutic targets for preventing development of PM and for enhancing cytotoxic effects of conventional systemic chemotherapy.

15.
ANZ J Surg ; 89(9): 1102-1107, 2019 09.
Article in English | MEDLINE | ID: mdl-31115159

ABSTRACT

BACKGROUND: Acute abdomen is a time-critical condition, which requires prompt diagnosis, initiation of first-line preoperative therapy and expedient surgical intervention. The earliest opportunity to intervene occurs at presentation to the emergency department triage. The aim of this audit was to evaluate the relationship between emergency triage and time performance measures in the preoperative management of abdominal emergencies. METHODS: Retrospective audit of time performance measures of key clinical events from emergency triage. Patient characteristics, elapsed time from triage to commencement of fluid resuscitation, intravenous antibiotics and emergency surgery and post-operative outcomes were obtained from review of operative medical records data over a 1-year duration. RESULTS: There was variability in triage allocation of patients with acute abdomen requiring urgent surgery. Category 3 was the most commonly assigned triage category (65.6%). The majority of patients (94.8%) had initial clinical assessment within the National Emergency Access Target '4-hour' rule, and 41.7% seen within 1-h from triage. Despite this, in cases of intra-abdominal sepsis, there was nearly a fourfold elapsed time for first dose intravenous antibiotics, beyond the 1-h recommendation in the Sepsis Kills pathway. There was non-significant trend in faster overall time performances with successive higher triage category allocation. CONCLUSION: This study highlights an opportunity to consider alternative triage methods or fast-track of patients with acute abdomen to promote early surgical assessment, resuscitation, antibiotic therapy and definitive intervention.


Subject(s)
Clinical Audit , Emergency Service, Hospital , Preoperative Care , Triage/methods , Abdomen, Acute , Adolescent , Adult , Aged , Aged, 80 and over , Child , Emergency Treatment , Female , Humans , Male , Middle Aged , Retrospective Studies , Time Factors , Young Adult
16.
J Pharmacol Exp Ther ; 369(1): 47-54, 2019 04.
Article in English | MEDLINE | ID: mdl-30635474

ABSTRACT

Friedreich ataxia (FRDA) is a progressive neuro- and cardio-degenerative disorder characterized by ataxia, sensory loss, and hypertrophic cardiomyopathy. In most cases, the disorder is caused by GAA repeat expansions in the first introns of both alleles of the FXN gene, resulting in decreased expression of the encoded protein, frataxin. Frataxin localizes to the mitochondrial matrix and is required for iron-sulfur-cluster biosynthesis. Decreased expression of frataxin is associated with mitochondrial dysfunction, mitochondrial iron accumulation, and increased oxidative stress. Ferropotosis is a recently identified pathway of regulated, iron-dependent cell death, which is biochemically distinct from apoptosis. We evaluated whether there is evidence for ferroptotic pathway activation in cellular models of FRDA. We found that primary patient-derived fibroblasts, murine fibroblasts with FRDA-associated mutations, and murine fibroblasts in which a repeat expansion had been introduced (knockin/knockout) were more sensitive than normal control cells to erastin, a known ferroptosis inducer. We also found that the ferroptosis inhibitors ethyl 3-(benzylamino)-4-(cyclohexylamino)benzoate (SRS11-92) and ethyl 3-amino-4-(cyclohexylamino)benzoate, used at 500 nM, were efficacious in protecting human and mouse cellular models of FRDA treated with ferric ammonium citrate (FAC) and an inhibitor of glutathione synthesis [L-buthionine (S,R)-sulfoximine (BSO)], whereas caspase-3 inhibitors failed to show significant biologic activity. Cells treated with FAC and BSO consistently showed decreased glutathione-dependent peroxidase activity and increased lipid peroxidation, both hallmarks of ferroptosis. Finally, the ferroptosis inhibitor SRS11-92 decreased the cell death associated with frataxin knockdown in healthy human fibroblasts. Taken together, these data suggest that ferroptosis inhibitors may have therapeutic potential in FRDA.


Subject(s)
Ferroptosis/drug effects , Friedreich Ataxia/drug therapy , Friedreich Ataxia/pathology , Molecular Targeted Therapy/methods , Animals , Cell Line , Friedreich Ataxia/metabolism , Gene Knockdown Techniques , Glutathione/biosynthesis , Humans , Iron/metabolism , Iron-Binding Proteins/genetics , Iron-Binding Proteins/metabolism , Lipid Peroxidation/drug effects , Mice , Mitochondria/drug effects , Mitochondria/metabolism , Oxidative Stress/drug effects , Piperazines/pharmacology , Frataxin
17.
Pathology ; 50(6): 654-658, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30177219

ABSTRACT

Vitamin C is an essential micronutrient in the human diet. While large population studies measuring vitamin C have been performed in other countries, there are few studies of deficiency in the Australian population. This study aimed to quantify vitamin C deficiency, identify scorbutic symptoms and examine dietary associations in a cohort of preoperative general surgical patients. Vitamin C levels were determined in a cohort of patients referred to a single surgeon between January 2011 and December 2013. Baseline data were collected along with data on fruit consumption, weekly citrus fruit intake and presence of scorbutic symptoms. A total of 309 patients were included in the study and 21.4% of our cohort showed a vitamin C level ≤11.4 µmol/L (deficient). Mean citrus fruit intake was significantly higher in the normal vitamin C groups (>28.4 µmol/L) and patients with vitamin C levels ≤28.4 were more likely to consume no fruit (p=0.0004) which was also significant on multivariate analysis. Neither age nor gender appeared predictive of suboptimal vitamin C levels. No symptoms were significantly related to vitamin C levels on multivariate analysis. Vitamin C deficiency was common in Australian adults attending a surgical practice within south western Sydney. Review of the Australian recommended daily allowance for vitamin C is suggested, not only in clinically well patients but particularly in ICU and hospital inpatients. Larger studies examining the prevalence and impact of vitamin C deficiency in the Australian population are required to further investigate these findings.


Subject(s)
Ascorbic Acid Deficiency/epidemiology , Adult , Aged , Australia/epidemiology , Cohort Studies , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Prevalence
19.
Gastroenterol Rep (Oxf) ; 6(3): 157-166, 2018 Aug.
Article in English | MEDLINE | ID: mdl-30151199

ABSTRACT

Clostridium difficile is a major cause of hospital-associated diarrhoea, and in severe cases leads to pseudomembranous colitis and toxic megacolon. The frequency of C. difficile infection (CDI) has increased in recent decades, with 453 000 cases identified in 2011 in the USA. This is related to antibiotic-selection pressure, disruption of normal host intestinal microbiota and emergence of antibiotic-resistant C. difficile strains. The burden of community-acquired CDI has been increasingly appreciated, with disease identified in patients previously considered low-risk, such as young women or patients with no prior antibiotic exposure. C. difficile has been identified in livestock animals, meat products, seafood and salads. It has been postulated that the pool of C. difficile in the agricultural industry may contribute to human CDI. There is widespread environmental dispersal of C. difficile spores. Domestic households, turf lawns and public spaces are extensively contaminated, providing a potential reservoir for community-acquired CDI. In Australia, this is particularly associated with porcine-derived C. difficile UK PCR ribotype 014/020. In this article, the epidemiological differences between hospital- and community-acquired CDI are discussed, including some emerging evidence for community-acquired CDI being a possible zoonosis.

20.
Sci Rep ; 8(1): 5007, 2018 03 22.
Article in English | MEDLINE | ID: mdl-29568068

ABSTRACT

Friedreich ataxia (FRDA) is an autosomal recessive neuro- and cardio-degenerative disorder caused by decreased expression of frataxin, a protein that localizes to mitochondria and is critical for iron-sulfur-cluster (ISC) assembly. There are no proven effective treatments for FRDA. We previously screened a random shRNA library and identified a synthetic shRNA (gFA11) that reverses the growth defect of FRDA cells in culture. We now report that gFA11 decreases cytokine secretion in primary FRDA fibroblasts and reverts other changes associated with cell senescence. The gene-expression profile induced by gFA11 is remarkably similar to the gene-expression profile induced by the p38 MAPK inhibitor SB203580. We found that p38 phosphorylation, indicating activation of the p38 pathway, is higher in FRDA cells than in normal control cells, and that siRNA knockdown of frataxin in normal fibroblasts also increases p38 phosphorylation. Treatment of FRDA cells with p38 inhibitors recapitulates the reversal of the slow-growth phenotype induced by clone gFA11. These data highlight the involvement of the p38 MAPK pathway in the pathogenesis of FRDA and the potential use of p38 inhibitors as a treatment for FRDA.


Subject(s)
Friedreich Ataxia/drug therapy , Iron-Binding Proteins/metabolism , Mitogen-Activated Protein Kinase 14/metabolism , RNA, Small Interfering/metabolism , Cells, Cultured , Computational Biology , Enzyme Inhibitors/pharmacology , Fibroblasts , Friedreich Ataxia/etiology , Friedreich Ataxia/pathology , Gene Expression Profiling , Gene Knockdown Techniques , Humans , Imidazoles/pharmacology , Iron-Binding Proteins/genetics , Mitogen-Activated Protein Kinase 14/antagonists & inhibitors , Phosphorylation/drug effects , Primary Cell Culture , Pyridines/pharmacology , Signal Transduction/drug effects , Signal Transduction/genetics , Frataxin
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