Clinical School (Royal Melbourne Hospital) - Research Publications
Now showing items 1-28 of 28
The Australian laparoscopic radical prostatectomy learning curve
BACKGROUND: International estimates of the laparoscopic radical prostatectomy (LRP) learning curve extend to as many as 1000 cases, but is unknown for Fellowship-trained Australian surgeons. METHODS: Prospectively collected data from nine Australian surgeons who performed 2943 consecutive LRP cases was retrospectively reviewed. Their combined initial 100 cases (F100, n = 900) were compared to their second 100 cases (S100, n = 782) with two of nine surgeons completing fewer than 200 cases. RESULTS: The mean age (61.1 versus 61.1 years) and prostate specific antigen (7.4 versus 7.8 ng/mL) were similar between F100 and S100. D'Amico's high-, intermediate- and low-risk cases were 15, 59 and 26% for the F100 versus 20, 59 and 21% for the S100, respectively. Blood transfusions (2.4 versus 0.8%), mean blood loss (413 versus 378 mL), mean operating time (193 versus 163 min) and length of stay (2.7 versus 2.4 days) were all lower in the S100. Histopathology was organ confined (pT2) in 76% of F100 and 71% of S100. Positive surgical margin (PSM) rate was 18.4% in F100 versus 17.5% in the S100 (P = 0.62). F100 and S100 PSM rates by pathological stage were similar with pT2 PSM 12.2 versus 9.5% (P = 0.13), pT3a PSM 34.8 versus 40.5% (P = 0.29) and pT3b PSM 52.9 versus 36.4% (P = 0.14). CONCLUSION: There was no significant improvement in PSM rate between F100 and S100 cases. Perioperative outcomes were acceptable in F100 and further improved with experience in S100. Mentoring can minimize the LRP learning curve, and it remains a valid minimally invasive surgical treatment for prostate cancer in Australia even in early practice.
Accuracy and safety of ward based pleural ultrasound in the Australian healthcare system
BACKGROUND AND OBJECTIVE: Ultrasound has been shown to improve the accuracy and safety of pleural procedures. Studies to date have been performed in large, specialized units, where pleural procedures are performed by a small number of highly specialized physicians. There are no studies examining the safety and accuracy of ultrasound in the Australian healthcare system where procedures are performed by junior doctors with a high staff turnover. METHODS: We performed a retrospective review of the ultrasound database in the Respiratory Department at the Royal Melbourne Hospital to determine accuracy and complications associated pleural procedures. RESULTS: A total of 357 ultrasounds were performed between October 2010 and June 2013. Accuracy of pleural procedures was 350 of 356 (98.3%). Aspiration of pleural fluid was successful in 121 of 126 (96%) of patients. Two (0.9%) patients required chest tube insertion for management of pneumothorax. There were no recorded pleural infections, haemorrhage or viscera puncture. CONCLUSION: Ward-based ultrasound for pleural procedures is safe and accurate when performed by appropriately trained and supported junior medical officers. Our findings support this model of pleural service care in the Australian healthcare system.
Evaluation of the transferability of survival calculators for stage II/III colon cancer across healthcare systems
Adjuvant! Online Inc (A!O), the Memorial Sloan Kettering Cancer Center (MSKCC), MD Anderson (MDA) and Mayo Clinic (MC) provide calculators to predict survival probabilities for patients with resected early-stage colon cancer, trained on data from United States (US) patient cohorts or patients enrolled in international clinical trials. Limited data exist on the transferability of calculators across healthcare systems. Calculator transferability to Australian community practice was evaluated for 1,401 stage II/III patients. Calibration and discrimination were assessed for overall (OS), cancer-specific (CSS) or recurrence-free survival (RFS). The US patient cohort-based calculators, A!O, MSKCC and MDA, significantly overestimated risks of recurrence and death in Australian patients, with 5-year OS, CSS and RFS prediction differences of -6.5% to -9.9%, -9.1% to -14.4% and - 3.8% to -6.8%, respectively (p < 0.001). Significant heterogeneity in calibration was observed for subgroups by tumor stage and treatment, age, gender, tumor location, ECOG and ASA score. Calibration appeared acceptable for the clinical trial patient-based MC calculator, but restricted tool applicability (stage III patients, ≥12 examined lymph nodes, receiving adjuvant treatment) limited the sample size. Compared to AJCC 7th edition tumor staging, calculators showed improved discrimination for OS, but no improvement for CSS and RFS. In conclusion, deficiencies in calibration limited transferability of US patient cohort-based survival calculators for early-stage colon cancer to the setting of Australian community practice. Our results demonstrate the utility for multi-feature survival calculators to improve OS predictions but highlight the importance for performance assessment of tools prior to implementation in an external health care setting.
Robotic-assisted radical cystectomy with intracorporeal urinary diversion versus open: early Australian experience
BACKGROUND: The aim of this study was to describe our initial Australian single surgeon experience with robotic-assisted radical cystectomy (RARC) and intracorporeal urinary diversion (ICUD) and to compare the outcomes with open radical cystectomy (ORC). METHODS: Between January 2014 and June 2016, consecutive patients diagnosed with muscle invasive and high-risk non-muscle invasive bladder cancer undergoing radical cystectomy were included. Treatment modalities included either RARC with ICUD or ORC. ICUD consisted of either intracorporeal ileal conduit or orthotopic neobladder formation. Prospectively collected perioperative and oncological outcomes were analysed. RESULTS: Twenty-six RARC and 13 ORC were performed. Median operating times were 362 and 240 min for RARC and ORC, respectively (P < 0.001). Estimated blood loss for RARC was 300 mL compared with 500 mL for ORC (P = 0.01). Post-operative haemoglobin drop was less in the RARC cohort (20% versus 24%, P = 0.03). There was no statistical difference in overall 90-day complication rates (81% versus 62%, P = 0.25) and 90-day major complication rates (19% versus 23%, P = 0.67) between the RARC and ORC groups, respectively. Positive surgical margins for RARC were 4% and 8% for ORC (P = 1.0). CONCLUSION: Early results demonstrate that the safe introduction of RARC with ICUD in Australia is potentially feasible without compromising perioperative and oncological outcomes. Future randomized trial with larger numbers will be required for further analysis in the Australian setting.
Real-world outcomes for neoadjuvant capecitabine versus infusional 5-fluorouracil in the treatment of locally advanced rectal cancer
BACKGROUND: Neoadjuvant chemoradiation therapy is standard-of-care treatment for locally advanced rectal cancer (LARC). A pathological complete response (pCR) following chemoradiation therapy is an early indicator of treatment benefit and associated with excellent survival outcomes, with capecitabine largely replacing infusional 5-fluorouracil as the choice in routine care of LARC. AIMS: To analyse the uptake of capecitabine usage over time, and on the back of clinical trial data demonstrating equivalence between fluoropyrimidines, confirm that efficacy is maintained in the real-world setting. METHODS: We analysed data from a prospectively maintained colorectal cancer database at three Australian hospitals including patients diagnosed from January 2009 to December 2018. Pathological response was determined as either complete or incomplete and compared for patients receiving 5-FU or capecitabine. RESULTS: A total of 657 patients was analysed, 498 receiving infusional 5-FU and 159 capecitabine. Capecitabine use has markedly increased from approval in 2014 in Australia, now being used in more than 80% of patients. Patient characteristics were similar by treatment, including age, tumour location and pre-treatment stage. pCR was reported in 22/159 (13.8%) of capecitabine-treated patients and 118/380 (23.7%) that received 5-FU (P ≤ 0.01). More capecitabine-treated patients received post-operative oxaliplatin (44.2% vs 6.3%, P < 0.01). Two-year progression-free survival was similar (84.9% vs 88.0%, P = 0.34). CONCLUSIONS: Capecitabine is now the dominantly used neoadjuvant chemotherapy in LARC. Capecitabine use was associated with a lower rate of pCR versus infusional 5-FU, a difference not explained by examined patient or tumour characteristics. Poor treatment compliance with oral therapy in the real-world setting is one possible explanation.
Vertebral fractures following stereotactic body radiotherapy for spine metastases
Stereotactic body radiotherapy has emerged as one of the preferred treatments for patients with spine metastases, with the potential for long-term control from lesion irradiation. Post-treatment vertebral compression fractures are a known complication of this therapy, contributing to worsening pain and reduced quality of life, sometimes requiring surgical intervention. This review explores the current knowledge of post-radiotherapy fractures, in terms of the rates and associated predictive factors. A search of databases including Medline, Embase and the Cochrane Library was conducted using keywords such as 'vertebral compression fracture', 'stereotactic body radiotherapy' and 'spine metastases'. The search was limited to published studies up to March 2019, reporting clinical outcomes including both the post-treatment fracture rate and statistical identification of associated risk factors. Rates of post-treatment fractures ranged from 4 to 39%. A variety of factors were found to increase the risk, including the appearance of lytic vertebral disease, degree of pre-existing compression, spinal malalignment, increased dose per fraction and a Spinal Instability Neoplastic Score >6. This knowledge can enable clinicians to counsel patients when considering management options for spine metastases, maintaining the balance between local tumour control and the risk of subsequent fracture.
Linkage to chromosome 2q32.2-q33.3 in familial serrated neoplasia (Jass syndrome)
Causative genetic variants have to date been identified for only a small proportion of familial colorectal cancer (CRC). While conditions such as Familial Adenomatous Polyposis and Lynch syndrome have well defined genetic causes, the search for variants underlying the remainder of familial CRC is plagued by genetic heterogeneity. The recent identification of families with a heritable predisposition to malignancies arising through the serrated pathway (familial serrated neoplasia or Jass syndrome) provides an opportunity to study a subset of familial CRC in which heterogeneity may be greatly reduced. A genome-wide linkage screen was performed on a large family displaying a dominantly-inherited predisposition to serrated neoplasia genotyped using the Affymetrix GeneChip Human Mapping 10 K SNP Array. Parametric and nonparametric analyses were performed and resulting regions of interest, as well as previously reported CRC susceptibility loci at 3q22, 7q31 and 9q22, were followed up by finemapping in 10 serrated neoplasia families. Genome-wide linkage analysis revealed regions of interest at 2p25.2-p25.1, 2q24.3-q37.1 and 8p21.2-q12.1. Finemapping linkage and haplotype analyses identified 2q32.2-q33.3 as the region most likely to harbour linkage, with heterogeneity logarithm of the odds (HLOD) 2.09 and nonparametric linkage (NPL) score 2.36 (P = 0.004). Five primary candidate genes (CFLAR, CASP10, CASP8, FZD7 and BMPR2) were sequenced and no segregating variants identified. There was no evidence of linkage to previously reported loci on chromosomes 3, 7 and 9.
Epilepsy, hippocampal sclerosis and febrile seizures linked by common genetic variation around SCN1A
(OXFORD UNIV PRESS, 2013-10-01)
Epilepsy comprises several syndromes, amongst the most common being mesial temporal lobe epilepsy with hippocampal sclerosis. Seizures in mesial temporal lobe epilepsy with hippocampal sclerosis are typically drug-resistant, and mesial temporal lobe epilepsy with hippocampal sclerosis is frequently associated with important co-morbidities, mandating the search for better understanding and treatment. The cause of mesial temporal lobe epilepsy with hippocampal sclerosis is unknown, but there is an association with childhood febrile seizures. Several rarer epilepsies featuring febrile seizures are caused by mutations in SCN1A, which encodes a brain-expressed sodium channel subunit targeted by many anti-epileptic drugs. We undertook a genome-wide association study in 1018 people with mesial temporal lobe epilepsy with hippocampal sclerosis and 7552 control subjects, with validation in an independent sample set comprising 959 people with mesial temporal lobe epilepsy with hippocampal sclerosis and 3591 control subjects. To dissect out variants related to a history of febrile seizures, we tested cases with mesial temporal lobe epilepsy with hippocampal sclerosis with (overall n = 757) and without (overall n = 803) a history of febrile seizures. Meta-analysis revealed a genome-wide significant association for mesial temporal lobe epilepsy with hippocampal sclerosis with febrile seizures at the sodium channel gene cluster on chromosome 2q24.3 [rs7587026, within an intron of the SCN1A gene, P = 3.36 × 10(-9), odds ratio (A) = 1.42, 95% confidence interval: 1.26-1.59]. In a cohort of 172 individuals with febrile seizures, who did not develop epilepsy during prospective follow-up to age 13 years, and 6456 controls, no association was found for rs7587026 and febrile seizures. These findings suggest SCN1A involvement in a common epilepsy syndrome, give new direction to biological understanding of mesial temporal lobe epilepsy with hippocampal sclerosis with febrile seizures, and open avenues for investigation of prognostic factors and possible prevention of epilepsy in some children with febrile seizures.
Mortality in dialysis patients may not be associated with ESA dose: a 2-year prospective observational study
BACKGROUND: Anaemia of chronic kidney disease increases the risk of death and adverse events, but can be managed using erythropoiesis stimulating agents (ESAs). However, recent evidence suggests that targeting a higher haemoglobin concentration ([Hb]) increases mortality risk, and both higher [Hb] targets and ESA doses have been implicated. Nonetheless, a causative role has not been demonstrated, and this potential relationship requires further appraisal in such a complex patient group. METHODS: The relationship between the haematopoietic response to ESAs and patient survival in 302 stable, prevalent dialysis patients was explored in a prospective, single-centre study. Clinical and laboratory parameters influencing mortality and ESA resistance were analysed. Patients were stratified into 5 groups, according to their [Hb] and ESA dosage, and were followed for 2 years. RESULTS: Little difference in co-morbidities between groups was identified. 73 patients died and 36 were transplanted. Initial analysis suggested a direct relationship between mortality and ESA dosage. However, Cox proportional hazards multivariate analysis demonstrated mortality risk was associated only with age (adjusted HR per year: 1.061, 95% CI 1.031-1.092), dialysis duration (adjusted HR: 1.010, 95% CI 1.004-1.016), peripheral vascular disease (adjusted HR: 1.967, 95% CI 1.083-3.576) and CRP (adjusted HR: 1.024, 95% CI 1.011-1.039). Mortality was increased in patients poorly responsive to ESAs (55.5%). CONCLUSION: ESA dose does not appear to contribute substantially to mortality risk in dialysis patients. Instead, age and co-morbidities appear to be the critical determinants. A poor response to ESAs is a marker of overall poor health status.
Investigating the Potential Role of Genetic and Epigenetic Variation of DNA Methyltransferase Genes in Hyperplastic Polyposis Syndrome
(PUBLIC LIBRARY SCIENCE, 2011-02-10)
BACKGROUND: Hyperplastic Polyposis Syndrome (HPS) is a condition associated with multiple serrated polyps, and an increased risk of colorectal cancer (CRC). At least half of CRCs arising in HPS show a CpG island methylator phenotype (CIMP), potentially linked to aberrant DNA methyltransferase (DNMT) activity. CIMP is associated with methylation of tumor suppressor genes including regulators of DNA mismatch repair (such as MLH1, MGMT), and negative regulators of Wnt signaling (such as WIF1). In this study, we investigated the potential for interaction of genetic and epigenetic variation in DNMT genes, in the aetiology of HPS. METHODS: We utilized high resolution melting (HRM) analysis to screen 45 cases with HPS for novel sequence variants in DNMT1, DNMT3A, DNMT3B, and DNMT3L. 21 polyps from 13 patients were screened for BRAF and KRAS mutations, with assessment of promoter methylation in the DNMT1, DNMT3A, DNMT3B, DNMT3L MLH1, MGMT, and WIF1 gene promoters. RESULTS: No pathologic germline mutations were observed in any DNA-methyltransferase gene. However, the T allele of rs62106244 (intron 10 of DNMT1 gene) was over-represented in cases with HPS (p<0.01) compared with population controls. The DNMT1, DNMT3A and DNMT3B promoters were unmethylated in all instances. Interestingly, the DNMT3L promoter showed low levels of methylation in polyps and normal colonic mucosa relative to matched disease free cells with methylation level negatively correlated to expression level in normal colonic tissue. DNMT3L promoter hypomethylation was more often found in polyps harbouring KRAS mutations (p = 0.0053). BRAF mutations were common (11 out of 21 polyps), whilst KRAS mutations were identified in 4 of 21 polyps. CONCLUSIONS: Genetic or epigenetic alterations in DNMT genes do not appear to be associated with HPS, but further investigation of genetic variation at rs62106244 is justified given the high frequency of the minor allele in this case series.
Increased serum kallistatin levels in type 1 diabetes patients with vascular complications.
(Publiverse Online S.R.L, 2010-09-22)
BACKGROUND: Kallistatin, a serpin widely produced throughout the body, has vasodilatory, anti-angiogenic, anti-oxidant, and anti-inflammatory effects. Effects of diabetes and its vascular complications on serum kallistatin levels are unknown. METHODS: Serum kallistatin was quantified by ELISA in a cross-sectional study of 116 Type 1 diabetic patients (including 50 with and 66 without complications) and 29 non-diabetic controls, and related to clinical status and measures of oxidative stress and inflammation. RESULTS: Kallistatin levels (mean(SD)) were increased in diabetic vs. control subjects (12.6(4.2) vs. 10.3(2.8) μg/ml, p = 0.007), and differed between diabetic patients with complications (13.4(4.9) μg/ml), complication-free patients (12.1(3.7) μg/ml), and controls; ANOVA, p = 0.007. Levels were higher in diabetic patients with complications vs. controls, p = 0.01, but did not differ between complication-free diabetic patients and controls, p > 0.05. On univariate analyses, in diabetes, kallistatin correlated with renal dysfunction (cystatin C, r = 0.28, p = 0.004; urinary albumin/creatinine, r = 0.34, p = 0.001; serum creatinine, r = 0.23, p = 0.01; serum urea, r = 0.33, p = 0.001; GFR, r = -0.25, p = 0.009), total cholesterol (r = 0.28, p = 0.004); LDL-cholesterol (r = 0.21, p = 0.03); gamma-glutamyltransferase (GGT) (r = 0.27, p = 0.04), and small artery elasticity, r = -0.23, p = 0.02, but not with HbA1c, other lipids, oxidative stress or inflammation. In diabetes, geometric mean (95%CI) kallistatin levels adjusted for covariates, including renal dysfunction, were higher in those with vs. without hypertension (13.6 (12.3-14.9) vs. 11.8 (10.5-13.0) μg/ml, p = 0.03). Statistically independent determinants of kallistatin levels in diabetes were age, serum urea, total cholesterol, SAE and GGT, adjusted r2 = 0.24, p < 0.00001. CONCLUSIONS: Serum kallistatin levels are increased in Type 1 diabetic patients with microvascular complications and with hypertension, and correlate with renal and vascular dysfunction.
The devil is in the detail - a multifactorial intervention to reduce blood pressure in coexisting diabetes and chronic kidney disease: a single blind, randomized controlled trial
BACKGROUND: About 30-60% of individuals are non-adherent to their prescribed medications and this risk increases as the number of prescribed medications increases. This paper outlines the development of a consumer-centred Medicine Self-Management Intervention (MESMI), designed to improve blood pressure control and medication adherence in consumers with diabetes and chronic kidney disease recruited from specialist outpatients' clinics. METHODS: We developed a multifactorial intervention consisting of Self Blood Pressure Monitoring (SBPM), medication review, a twenty-minute interactive Digital Versatile Disc (DVD), and follow-up support telephone calls to help consumers improve their blood pressure control and take their medications as prescribed. The intervention is novel in that it has been developed from analysis of consumer and health professional views, and includes consumer video exemplars in the DVD. The primary outcome measure was a drop of 3-6 mmHg systolic blood pressure at three months after completion of the intervention. Secondary outcome measures included: assessment of medication adherence, medication self-efficacy and general wellbeing. Consumers' adherence to their prescribed medications was measured by manual pill count, self-report of medication adherence, and surrogate biochemical markers of disease control. DISCUSSION: The management of complex health problems is an increasing component of health care practice, and requires interventions that improve patient outcomes. We describe the preparatory work and baseline data of a single blind, randomized controlled trial involving consumers requiring cross-specialty care with a follow-up period extending to 12 months post-baseline. TRIAL REGISTRATION: The trial was registered with the Australian and New Zealand Clinical Trials Register (ACTRN12607000044426).
Unaccustomed Eccentric Contractions Impair Plasma K+ Regulation in the Absence of Changes in Muscle Na+, K+- ATPase Content
(PUBLIC LIBRARY SCIENCE, 2014-06-24)
The Na+,K+-ATPase (NKA) plays a fundamental role in the regulation of skeletal muscle membrane Na+ and K+ gradients, excitability and fatigue during repeated intense contractions. Many studies have investigated the effects of acute concentric exercise on K+ regulation and skeletal muscle NKA, but almost nothing is known about the effects of repeated eccentric contractions. We therefore investigated the effects of unaccustomed maximal eccentric knee extensor contractions on K+ regulation during exercise, peak knee extensor muscle torque, and vastus lateralis muscle NKA content and 3-O-MFPase activity. Torque measurements, muscle biopsies, and venous blood samples were taken before, during and up to 7 days following the contractions in six healthy adults. Eccentric contractions reduced peak isometric muscle torque immediately post-exercise by 26±11% and serum creatine kinase concentration peaked 24 h post-exercise at 339±90 IU/L. During eccentric contractions, plasma [K+] rose during Set 1 and remained elevated at ∼4.9 mM during sets 4-10; this was despite a decline in work output by Set 4, which fell by 18.9% at set 10. The rise in plasma [K+] x work(-1) ratio was elevated over Set 2 from Set 4- Set 10. Eccentric contractions had no effect on muscle NKA content or maximal in-vitro 3-O-MFPase activity immediately post- or up to 7 d post-exercise. The sustained elevation in plasma [K+] despite a decrease in work performed by the knee extensor muscles suggests an impairment in K+ regulation during maximal eccentric contractions, possibly due to increased plasma membrane permeability or to excitation-contraction uncoupling.
Pooled genome wide association detects association upstream of FCRL3 with Graves' disease
BACKGROUND: Graves' disease is an autoimmune thyroid disease of complex inheritance. Multiple genetic susceptibility loci are thought to be involved in Graves' disease and it is therefore likely that these can be identified by genome wide association studies. This study aimed to determine if a genome wide association study, using a pooling methodology, could detect genomic loci associated with Graves' disease. RESULTS: Nineteen of the top ranking single nucleotide polymorphisms including HLA-DQA1 and C6orf10, were clustered within the Major Histo-compatibility Complex region on chromosome 6p21, with rs1613056 reaching genome wide significance (p = 5 × 10-8). Technical validation of top ranking non-Major Histo-compatablity complex single nucleotide polymorphisms with individual genotyping in the discovery cohort revealed four single nucleotide polymorphisms with p ≤ 10-4. Rs17676303 on chromosome 1q23.1, located upstream of FCRL3, showed evidence of association with Graves' disease across the discovery, replication and combined cohorts. A second single nucleotide polymorphism rs9644119 downstream of DPYSL2 showed some evidence of association supported by finding in the replication cohort that warrants further study. CONCLUSIONS: Pooled genome wide association study identified a genetic variant upstream of FCRL3 as a susceptibility locus for Graves' disease in addition to those identified in the Major Histo-compatibility Complex. A second locus downstream of DPYSL2 is potentially a novel genetic variant in Graves' disease that requires further confirmation.
Genes implicated in multiple sclerosis pathogenesis from consilience of genotyping and expression profiles in relapse and remission
BACKGROUND: Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Although the pathogenesis of MS remains unknown, it is widely regarded as an autoimmune disease mediated by T-lymphocytes directed against myelin proteins and/or other oligodendrocyte epitopes. METHODS: In this study we investigated the gene expression profiles of peripheral blood cells from patients with RRMS during the relapse and the remission phases utilizing gene microarray technology. Dysregulated genes encoded in regions associated with MS susceptibility from genomic screens or previous transcriptomic studies were identified. The proximal promoter region polymorphisms of two genes were tested for association with disease and expression level. RESULTS: Distinct sets of dysregulated genes during the relapse and remission phases were identified including genes involved in apoptosis and inflammation. Three of these dysregulated genes have been previously implicated with MS susceptibility in genomic screens: TGFbeta1, CD58 and DBC1. TGFbeta1 has one common SNP in the proximal promoter: -508 T>C (rs1800469). Genotyping two Australian trio sets (total 620 families) found a trend for over-transmission of the T allele in MS in females (p < 0.13). Upregulation of CD58 and DBC1 in remission is consistent with their putative roles in promoting regulatory T cells and reducing cell proliferation, respectively. A fourth gene, ALOX5, is consistently found over-expressed in MS. Two common genetic variants were confirmed in the ALOX5 putative promoter: -557 T>C (rs12762303) and a 6 bp tandem repeat polymorphism (GGGCGG) between position -147 and -176; but no evidence for transmission distortion found. CONCLUSION: The dysregulation of these genes tags their metabolic pathways for further investigation for potential therapeutic intervention.
Barriers and strategies to achieve a cure for HIV
(ELSEVIER INC, 2018-06-01)
9 years since the report of a cure for HIV after C-C chemokine receptor type 5 Δ32 stem cell transplantation, no other case of HIV cure has been reported, despite much research. However, substantial progress has been made in understanding the biology of the latent HIV reservoir, and in measuring the amount of virus that persists after antiretroviral therapy (ART) with increasingly sophisticated approaches. This knowledge is being translated into a long pipeline of clinical trials seeking to reduce viral persistence in participants on suppressive treatment and ultimately to allow safe cessation of ART. In this Review, we discuss the main barriers preventing the development of an HIV cure, methods used to measure HIV persistence in individuals on ART, clinical strategies that aim to cure HIV, and future directions for studies in the field of HIV cure research.
Understanding factors influencing physical activity and exercise in lung cancer: a systematic review
PURPOSE: Despite evidence and clinical practice guidelines supporting physical activity (PA) for people with lung cancer, this evidence has not translated into clinical practice. This review aims to identify, evaluate and synthesise studies examining the barriers and enablers for patients with lung cancer to participate in PA from the perspective of patients, carers and health care providers (HCPs). METHODS: Systematic review of articles using electronic databases: MEDLINE (1950-2016), CINAHL (1982-2016), EMBASE (1980-2016), Scopus (2004-2016) and Cochrane (2016). Quantitative and qualitative studies, published in English in a peer-reviewed journal, which assessed the barriers or enablers to PA for patients with lung cancer were included. Registered-PROSPERO (CRD4201603341). RESULTS: Twenty-six studies (n = 9 cross-sectional, n = 4 case series, n = 11 qualitative) including 1074 patients, 23 carers and 169 HCPs were included. Barriers and enablers to PA were identified (6 major themes, 18 sub-themes): Barriers included patient-level factors (physical capability, symptoms, comorbidities, previous sedentary lifestyle, psychological influences, perceived relevance), HCP factors (time/knowledge to deliver information) and environmental factors (access to services, resources, timing relative to treatment). Enablers included anticipated benefits, opportunity for behaviour change and influences from HCPs and carers. CONCLUSION: This systematic review has identified the volume of literature demonstrating that barriers and enablers to PA in lung cancer are multidimensional and span diverse factors. These include patient-level factors, such as symptoms, comorbidities, sedentary lifestyle, mood and fear, and environmental factors. These factors should be considered to identify and develop suitable interventions and clinical services in attempt to increase PA in patients with lung cancer.
Intensive care discharge delay is associated with increased hospital length of stay: A multicentre prospective observational study
(PUBLIC LIBRARY SCIENCE, 2017-07-27)
BACKGROUND: Some patients experience a delayed discharge from the intensive care unit (ICU) where the intended and actual discharge times do not coincide. The clinical implications of this remain unclear. OBJECTIVE: To determine the incidence and duration of delayed ICU discharge, identify the reasons for delay and evaluate the clinical consequences. METHODS: Prospective multi-centre observational study involving five ICUs over a 3-month period. Delay in discharge was defined as >6 hours from the planned discharge time. The primary outcome measure was hospital length stay after ICU discharge decision. Secondary outcome measures included ICU discharge after-hours, incidence of delirium, survival to hospital discharge, discharge destination, the incidence of ICU acquired infections, revocation of ICU discharge decision, unplanned readmissions to ICU within 72 hours, review of patients admitting team after ICU discharge decision. RESULTS: A total of 955 out of 1118 patients discharged were included in analysis. 49.9% of the patients discharge was delayed. The most common reason (74%) for delay in discharge was non-availability of ward bed. The median duration of the delay was 24 hours. On univariable analysis, the duration of hospital stay from the time of ICU discharge decision was significantly higher in patients who had ICU discharge delay (Median days-5 vs 6; p = 0.003). After-hours discharge was higher in patients whose discharge was delayed (34% Vs 10%; p<0.001). There was no statistically significant difference in the other secondary outcomes analysed. Multivariable analysis adjusting for known confounders revealed delayed ICU discharge was independently associated with increased hospital length of stay. CONCLUSION: Half of all ICU patients experienced a delay in ICU discharge. Delayed discharge was associated with increased hospital length of stay.
Early acid-base and blood pressure effects of continuous renal replacement therapy intensity in patients with metabolic acidosis
PURPOSE: In acute kidney injury patients, metabolic acidosis is common. Its severity, duration, and associated changes in mean arterial pressure (MAP) and vasopressor therapy may be affected by the intensity of continuous renal replacement therapy (CRRT). We aimed to compare key aspects of acidosis and MAP and vasopressor therapy in patients treated with two different CRRT intensities. METHODS: We studied a nested cohort of 115 patients from two tertiary intensive care units (ICUs) within a large multicenter randomized controlled trial treated with lower intensity (LI) or higher intensity (HI) CRRT. RESULTS: Levels of metabolic acidosis at randomization were similar [base excess (BE) of -8 ± 8 vs. -8 ± 7 mEq/l; p = 0.76]. Speed of BE correction did not differ between the two groups. However, the HI group had a greater increase in MAP from baseline to 24 h (7 ± 3 vs. 0 ± 3 mmHg; p < 0.01) and a greater decrease in norepinephrine dose (from 12.5 to 3.5 vs. 5 to 2.5 μg/min; p < 0.05). The correlation (r) coefficients between absolute change in MAP and norepinephrine (NE) dose versus change in BE were 0.05 and -0.37, respectively. CONCLUSIONS: Overall, LI and HI CRRT have similar acid-base effects in patients with acidosis. However, HI was associated with greater improvements in MAP and vasopressor requirements (clinical trial no. NCT00221013).
Diagnosis of interstitial cystitis/bladder pain syndrome in women with chronic pelvic pain: a prospective observational study
(SPRINGER LONDON LTD, 2012-10-01)
INTRODUCTION AND HYPOTHESIS: This study assesses the prevalence of interstitial cystitis (IC)/bladder pain syndrome (BPS) in women with chronic pelvic pain (CPP). METHODS: This was a prospective study of 150 women undergoing laparoscopy as investigation for CPP in an Endometriosis and Pelvic Pain unit. Preoperative questionnaires [demographic details, pelvic pain symptoms, the Pelvic Pain and Urgency/Frequency (PUF) and O'Leary-Sant (OLS) Symptom and Problem Index scores] were completed, and concurrent standardized cystoscopy with hydrodistention performed at laparoscopy. The primary outcome measures the proportion of IC in this group, defined by presence of glomerulations with CPP and urinary symptoms (urinary frequency, nocturia, urgency). The secondary outcome measures the proportion of BPS [defined by the European Society of the Study of Interstitial Cystitis (ESSIC)]. RESULTS: IC was diagnosed in 48/150 (32%) individuals, and 80/150 (53%) had BPS. There were no significant differences in symptomatology or questionnaire results between groups with and without IC. Women with BPS had higher PUF (17.2 vs 12.9, p < 0.001), OLS Symptom (8.2 vs 6.0, p = 0.001) and Problem (7.5 vs 4.2, p < 0.001) scores and more severe pain symptoms. Visually proven endometriosis was seen in 90/150 (60%), and 27/150 (18%) had both endometriosis and IC. Of the 80 women with BPS, 45/80 (60%) had endometriosis. CONCLUSIONS: The prevalence of IC/BPS varies depending on the definition used. This study showed IC in 32% of women with CPP based on symptoms and presence of glomerulations. BPS as defined by ESSIC was diagnosed in 53%. History and questionnaires did not correlate with positive cystoscopic findings.
The role of impairment of mesenchymal stem cell function in osteoporotic bone fracture healing
With demographic change and increasing life expectancy, osteoporotic fractures have become one of the most prevalent trauma conditions seen in daily clinical practice. A variety of factors are known to affect the rate of healing in osteoporotic conditions (e.g. both biochemical and biomechanical environment of callus cells). However, the influence of impairment of mesenchymal stem cell function in the osteoporotic condition on bone fracture healing has not been fully understood. In the present study, we develop a mathematical model that quantifies the change in biological processes within the fracture callus as a result of osteoporosis. The model includes special features of osteoporosis such as reduction in mesenchymal stem cell (MSC) number in osteoporotic bone, impaired response of osteoporotic MSCs to their biomechanical microenvironment and the effects of configuration of locking compression plate (LCP) system on healing in this context. The results presented here suggest that mechanically-mediated MSCs differentiation at early stages of healing are significantly affected under osteoporotic conditions, while it is predicted that the flexible fixation achieved by increasing bone-plate distance of LCP could alleviate the negative effects of osteoporosis on healing. The outcomes of this study could potentially lead to patient specific surgical solutions, and thus achieve optimal healing outcomes in osteoporotic conditions.
The relationship between interfragmentary movement and cell differentiation in early fracture healing under locking plate fixation
(Springer Netherlands, 2016)
Interfragmentary movement (IFM) at the fracture site plays an important role in fracture healing, particularly during its early stage, via influencing the mechanical microenvironment of mesenchymal stem cells within the fracture callus. However, the effect of changes in IFM resulting from the changes in the configuration of locking plate fixation on cell differentiation has not yet been fully understood. In this study, mechanical experiments on surrogate tibia specimens, manufactured from specially formulated polyurethane, were conducted to investigate changes in IFM of fractures under various locking plate fixation configurations and loading magnitudes. The effect of the observed IFM on callus cell differentiation was then further studied using computational simulation. We found that during the early stage, cell differentiation in the fracture callus is highly influenced by fracture gap size and IFM, which in turn, is highly sensitive to locking plate fixation configuration. The computational model predicted that a small gap size (e.g. 1 mm) under a relatively flexible configuration of locking plate fixation (larger bone-plate distances and working lengths) could experience excessive strain and fluid flow within the fracture site, resulting in excessive fibrous tissue differentiation and delayed healing. By contrast, a relatively flexible configuration of locking plate fixation was predicted to improve cartilaginous callus formation and bone healing for a relatively larger gap size (e.g. 3 mm). If further confirmed by animal and human studies, the research outcome of this paper may have implications for orthopaedic surgeons in optimising the application of locking plate fixations for fractures in clinical practice.
A good resource for parents, but will clinicians use it?: Evaluation of a resource for paediatric end-of-life decision making
BACKGROUND: Communication with parents about end-of-life care and decisions is a difficult and sensitive process. The objective of the present study was to ascertain clinicians' views on the acceptability and usefulness of a handbook and web-based resource (Caring Decisions) that was designed as an aid for parents facing end-of-life decisions for their child. METHODS: Qualitative interviews were conducted with a range of health professionals who provide care to children facing life-limiting conditions. RESULTS: Data analysis confirmed the acceptability and usefulness of the resource. Two major themes were revealed: 1. Family empowerment, with sub-themes Giving words and clarity, Conversation starter, 'I'm not alone in this', and A resource to take away, highlighted how the resource filled a gap by supporting and enabling families in a multitude of ways; 2. Not just for families, with sub-themes A guide for staff, When to give the resource?, How to give the resource and Who should give the resource?, explored the significant finding that participants viewed the resource as a valuable tool for themselves, but its presence also brought into relief potential gaps in communication processes around end-of-life care. CONCLUSION: The interview data indicated the positive reception and clear value and need for this type of resource. However, it is likely that successful resource uptake will be contingent on discussion and planning around dissemination and use within the health care team.
e Analysis of Platelet-Rich Plasma Extraction Variations in Platelet and Blood Components Between 4 Common Commercial Kits
(SAGE PUBLICATIONS INC, 2017-01-01)
BACKGROUND: Platelet-rich plasma (PRP) has been extensively used as a treatment in tissue healing in tendinopathy, muscle injury, and osteoarthritis. However, there is variation in methods of extraction, and this produces different types of PRP. PURPOSE: To determine the composition of PRP obtained from 4 commercial separation kits, which would allow assessment of current classification systems used in cross-study comparisons. STUDY DESIGN: Controlled laboratory study. METHODS: Three normal adults each donated 181 mL of whole blood, some of which served as a control and the remainder of which was processed through 4 PRP separation kits: GPS III (Biomet Biologics), Smart-Prep2 (Harvest Terumo), Magellan (Arteriocyte Medical Systems), and ACP (Device Technologies). The resultant PRP was tested for platelet count, red blood cell count, and white blood cell count, including differential in a commercial pathology laboratory. Glucose and pH measurements were obtained from a blood gas autoanalyzer machine. RESULTS: Three kits taking samples from the "buffy coat layer" were found to have greater concentrations of platelets (3-6 times baseline), while 1 kit taking samples from plasma was found to have platelet concentrations of only 1.5 times baseline. The same 3 kits produced an increased concentration of white blood cells (3-6 times baseline); these consisted of neutrophils, leukocytes, and monocytes. This represents high concentrations of platelets and white blood cells. A small drop in pH was thought to relate to the citrate used in the sample preparation. Interestingly, an unexpected increase in glucose concentrations, with 3 to 6 times greater than baseline levels, was found in all samples. CONCLUSION: This study reveals the variation of blood components, including platelets, red blood cells, leukocytes, pH, and glucose in PRP extractions. The high concentrations of cells are important, as the white blood cell count in PRP samples has frequently been ignored, being considered insignificant. The lack of standardization of PRP preparation for clinical use has contributed at least in part to the varying clinical efficacy in PRP use. CLINICAL RELEVANCE: The variation of platelet and other blood component concentrations between commercial PRP kits may affect clinical treatment outcomes. There is a need for standardization of PRP for clinical use.
A Tablet-Based Retinal Function Test in Neovascular Age-Related Macular Degeneration Eyes and At-Risk Fellow Eye
(ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2018-03-01)
Purpose: To determine the feasibility of a tablet-based application to detect changes in retinal sensitivity and correlations with underlying pathology in neovascular age-related macular degeneration (nAMD) eyes undergoing treatment and in at-risk fellow eyes. Method: Participants with nAMD in at least one eye were recruited, examined, and imaged using spectral-domain optical coherence tomography (SD-OCT). Retinal sensitivity was measured within the central 5° at 12 locations using a customized test delivered on an iPad. Test points were superimposed on SD-OCT locations to investigate structure/function relationships. Results: Included in the study were 53 nAMD eyes and 21 at-risk fellow eyes. In nAMD eyes, the mean retinal sensitivity was 24.1 ± 1.8 dB with reduced retinal sensitivity associated with the presence of atrophy (P < 0.01), retinal pigment epithelium (RPE) disruption (P < 0.01), and absent ellipsoid zone (EZ) (P < 0.01), but not with the presence of subretinal fluid (P = 0.94) nor intraretinal fluid (P = 0.52). In at-risk eyes, the average retinal sensitivity was 28.8 ± 0.6 dB, with reduced sensitivity significantly associated with the presence of drusen, atrophy, RPE disruption, and absent EZ (P < 0.01). Conclusion: The tablet-based test of retinal sensitivity was able to be performed by an elderly cohort with nAMD. The ability to correlate differences in sensitivity with pathology is encouraging when considering using the tablet devices as a home monitoring tool with remote surveillance. Dual pathology often present with retinal fluid confounded our ability to correlate fluid with sensitivity. Translational Relevance: These findings highlight the potential of tablet-based devices in performing visual function measures as a home monitoring tool with remote surveillance for the earlier detection of nAMD.
Undernutrition and malaria in pregnancy - a dangerous dyad?
BACKGROUND: In low-resource settings, malaria and macronutrient undernutrition are major health problems in pregnancy, contributing significantly to adverse pregnancy outcomes such as preterm birth and fetal growth restriction. Affected pregnancies may result in stillbirth and neonatal death, and surviving children are at risk of poor growth and infection in infancy, and of non-communicable diseases in adulthood. Populations exposed to macronutrient undernutrition frequently reside in malaria-endemic areas, and seasonal peaks of low food supply and malaria transmission tend to coincide. Despite these geographic and temporal overlaps, integrated approaches to these twin challenges are infrequent. DISCUSSION: This opinion article examines the current evidence for malaria-macronutrition interactions and discusses possible mechanisms whereby macronutrient undernutrition and malaria may interact to worsen pregnancy outcomes. Macronutrient undernutrition dysregulates the immune response. In pregnant women, undernutrition may worsen the already increased susceptibility to malarial infection and could impair development of protective immunity to malaria, and is likely to exacerbate the impact of placental malaria on fetal growth. Malarial infection, in turn, can drive nutritional depletion; poor gestational weight gain and weight loss in pregnancy increases the risk of adverse pregnancy outcomes. Despite a commendable number of studies and trials that, in isolation, attempt to address the challenges of malaria and undernutrition in pregnancy, few dare to venture beyond the 'single disease - single solution' paradigm. We believe that this may be a lost opportunity: researching malaria-nutrition interactions, and designing and implementing integrated interventions to prevent and treat these commonly co-existing and intertwining conditions, may markedly reduce the high burden of preterm birth and fetal growth restriction in affected areas. CONCLUSION: We call for more collaboration between researchers studying malaria and nutrition in pregnancy, and propose a research agenda to address this important twin health problem.
Quantitative Analysis of the Ellipsoid Zone Intensity in Phenotypic Variations of Intermediate Age-Related Macular Degeneration
(ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2017-04-01)
Purpose: Reduction of the ellipsoid zone (EZ) intensity has been reported in eyes with age-related macular degeneration (AMD). This study determined whether overall EZ intensity, in retinal locations undisturbed by pathologic features, is associated with the presence of clinical features, which are known important phenotypic risk factors for disease progression, large drusen, reticular pseudodrusen (RPD), and pigmentary abnormalities. Methods: A horizontal B-scan through the foveola on spectral-domain optical coherence tomography (SD-OCT) was performed in both eyes of 75 participants with bilateral intermediate AMD and 10 age-similar control participants. Eyes with AMD were classified as per the presence of large drusen, RPD, and hyperpigmentary changes. The relative EZ intensity profile, up to an eccentricity of 3400 μm, was averaged over seven 1000-μm retinal segments. The association between relative EZ intensity profile over seven retinal segments and AMD pathologic features was analyzed. Results: The average relative EZ intensities were significantly reduced in eyes with intermediate AMD compared to normal eyes (P ≤ 0.025) and with increasing age (P ≤ 0.020). On multivariate analyses, only the presence of hyperpigmentary changes and increasing age were significantly associated with reduced overall relative intensities (P ≤ 0.024), but not the presence of large drusen or RPD (P ≥ 0.115). Conclusions: The presence of hyperpigmentary change in the macula in association with large drusen, not large drusen alone, nor large drusen with RPD, was significantly associated with a generalised reduction in EZ intensity. Quantitative assessment of the relative EZ intensity may serve as an effective biomarker of disease severity and progression.
Common and Low Frequency Variants in MERTK Are Independently Associated with Multiple Sclerosis Susceptibility with Discordant Association Dependent upon HLA-DRB1*15:01 Status
(PUBLIC LIBRARY SCIENCE, 2016-03-01)
Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. The risk of developing MS is strongly influenced by genetic predisposition, and over 100 loci have been established as associated with susceptibility. However, the biologically relevant variants underlying disease risk have not been defined for the vast majority of these loci, limiting the power of these genetic studies to define new avenues of research for the development of MS therapeutics. It is therefore crucial that candidate MS susceptibility loci are carefully investigated to identify the biological mechanism linking genetic polymorphism at a given gene to the increased chance of developing MS. MERTK has been established as an MS susceptibility gene and is part of a family of receptor tyrosine kinases known to be involved in the pathogenesis of demyelinating disease. In this study we have refined the association of MERTK with MS risk to independent signals from both common and low frequency variants. One of the associated variants was also found to be linked with increased expression of MERTK in monocytes and higher expression of MERTK was associated with either increased or decreased risk of developing MS, dependent upon HLA-DRB1*15:01 status. This discordant association potentially extended beyond MS susceptibility to alterations in disease course in established MS. This study provides clear evidence that distinct polymorphisms within MERTK are associated with MS susceptibility, one of which has the potential to alter MERTK transcription, which in turn can alter both susceptibility and disease course in MS patients.