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Phillips RS, Sung L, Amman RA, Riley RD, Castagnola E, Haeusler GM, Klaassen R, Tissing WJE, Lehrnbecher T, Chisholm J, Hakim H, Ranasinghe N, Paesmans M, Hann IM, Stewart LA. Predicting microbiologically defined infection in febrile neutropenic episodes in children: global individual participant data multivariable meta-analysis. Br J Cancer 2016; 114:623-30. [PMID: 26954719 PMCID: PMC4800297 DOI: 10.1038/bjc.2016.28] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 01/13/2016] [Accepted: 01/16/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Risk-stratified management of fever with neutropenia (FN), allows intensive management of high-risk cases and early discharge of low-risk cases. No single, internationally validated, prediction model of the risk of adverse outcomes exists for children and young people. An individual patient data (IPD) meta-analysis was undertaken to devise one. METHODS The 'Predicting Infectious Complications in Children with Cancer' (PICNICC) collaboration was formed by parent representatives, international clinical and methodological experts. Univariable and multivariable analyses, using random effects logistic regression, were undertaken to derive and internally validate a risk-prediction model for outcomes of episodes of FN based on clinical and laboratory data at presentation. RESULTS Data came from 22 different study groups from 15 countries, of 5127 episodes of FN in 3504 patients. There were 1070 episodes in 616 patients from seven studies available for multivariable analysis. Univariable analyses showed associations with microbiologically defined infection (MDI) in many items, including higher temperature, lower white cell counts and acute myeloid leukaemia, but not age. Patients with osteosarcoma/Ewings sarcoma and those with more severe mucositis were associated with a decreased risk of MDI. The predictive model included: malignancy type, temperature, clinically 'severely unwell', haemoglobin, white cell count and absolute monocyte count. It showed moderate discrimination (AUROC 0.723, 95% confidence interval 0.711-0.759) and good calibration (calibration slope 0.95). The model was robust to bootstrap and cross-validation sensitivity analyses. CONCLUSIONS This new prediction model for risk of MDI appears accurate. It requires prospective studies assessing implementation to assist clinicians and parents/patients in individualised decision making.
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Weber C, Schwieterman M, Fier K, Berni J, Swartz N, Phillips RS, Reneker JC. Reliability and Validity of the Functional Gait Assessment: A Systematic Review. PHYSICAL & OCCUPATIONAL THERAPY IN GERIATRICS 2016. [DOI: 10.3109/02703181.2015.1128509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Phillips RS, Friend AJ, Gibson F, Houghton E, Gopaul S, Craig JV, Pizer B. Antiemetic medication for prevention and treatment of chemotherapy-induced nausea and vomiting in childhood. Cochrane Database Syst Rev 2016; 2:CD007786. [PMID: 26836199 PMCID: PMC7073407 DOI: 10.1002/14651858.cd007786.pub3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Nausea and vomiting remain a problem for children undergoing treatment for malignancies despite new antiemetic therapies. Optimising antiemetic regimens could improve quality of life by reducing nausea, vomiting, and associated clinical problems. This is an update of the original systematic review. OBJECTIVES To assess the effectiveness and adverse events of pharmacological interventions in controlling anticipatory, acute, and delayed nausea and vomiting in children and young people (aged less than 18 years) about to receive or receiving chemotherapy. SEARCH METHODS Searches included the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, PsycINFO, conference proceedings of the American Society of Clinical Oncology, International Society of Paediatric Oncology, Multinational Association of Supportive Care in Cancer, and ISI Science and Technology Proceedings Index from incept to December 16, 2014, and trial registries from their earliest records to December 2014. We examined references of systematic reviews and contacted trialists for information on further studies. We also screened the reference lists of included studies. SELECTION CRITERIA Two review authors independently screened abstracts in order to identify randomised controlled trials (RCTs) that compared a pharmacological antiemetic, cannabinoid, or benzodiazepine with placebo or any alternative active intervention in children and young people (less than 18 years) with a diagnosis of cancer who were to receive chemotherapy. DATA COLLECTION AND ANALYSIS Two review authors independently extracted outcome and quality data from each RCT. When appropriate, we undertook meta-analysis. MAIN RESULTS We included 34 studies that examined a range of different antiemetics, used different doses and comparators, and reported a variety of outcomes. The quality and quantity of included studies limited the exploration of heterogeneity to narrative approaches only.The majority of quantitative data related to the complete control of acute vomiting (27 studies). Adverse events were reported in 29 studies and nausea outcomes in 16 studies.Two studies assessed the addition of dexamethasone to 5-HT3 antagonists for complete control of vomiting (pooled risk ratio (RR) 2.03; 95% confidence interval (CI) 1.35 to 3.04). Three studies compared granisetron 20 mcg/kg with 40 mcg/kg for complete control of vomiting (pooled RR 0.93; 95% CI 0.80 to 1.07). Three studies compared granisetron with ondansetron for complete control of acute nausea (pooled RR 1.05; 95% CI 0.94 to 1.17; 2 studies), acute vomiting (pooled RR 2.26; 95% CI 2.04 to 2.51; 3 studies), delayed nausea (pooled RR 1.13; 95% CI 0.93 to 1.38; 2 studies), and delayed vomiting (pooled RR 1.13; 95% CI 0.98 to 1.29; 2 studies). No other pooled analyses were possible.Narrative synthesis suggests that 5-HT3 antagonists are more effective than older antiemetic agents, even when these agents are combined with a steroid. Cannabinoids are probably effective but produce frequent side effects. AUTHORS' CONCLUSIONS Our overall knowledge of the most effective antiemetics to prevent chemotherapy-induced nausea and vomiting in childhood is incomplete. Future research should be undertaken in consultation with children, young people, and families that have experienced chemotherapy and should make use of validated, age-appropriate measures. This review suggests that 5-HT3 antagonists are effective in patients who are to receive emetogenic chemotherapy, with granisetron or palonosetron possibly better than ondansetron. Adding dexamethasone improves control of vomiting, although the risk-benefit profile of adjunctive steroid remains uncertain.
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Morgan JE, McKeever K, Tyerman KS, Henderson M, Picton S, Phillips RS. Aminoaciduria in the prediction of ifosfamide-induced tubulopathy after childhood cancer: a feasibility study. Pilot Feasibility Stud 2016; 2:4. [PMID: 27965825 PMCID: PMC5154030 DOI: 10.1186/s40814-015-0040-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 12/03/2015] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Ifosfamide, an alkylating agent used widely in the treatment of childhood malignancy, can cause many side effects including a proximal tubulopathy. Studies suggest that aminoaciduria is seen most commonly of all the biochemical abnormalities of ifosfamide-induced tubulopathy. A recent systematic review has found a paucity of data regarding the value of early markers indicating clinically significant tubulopathy. We undertook a pilot study to determine the feasibility of examining whether patients can be risk-stratified on the basis of aminoaciduria for the development of future significant ifosfamide-induced tubulopathy, to allow the evolution of appropriate follow-up strategies. We also aimed to define accrual rates, costs and clinical demands for a future larger study. METHODS This observational study recruited 21 patients from the Leeds Paediatric Oncology service. The medical notes of each patient were reviewed for demographic and clinical data. Simultaneous samples of blood and urine were obtained. RESULTS The investigations in the feasibility study were acceptable to patients and were minimally demanding on both clinical and laboratory staff. Financially, the cost per patient was minimal. This study was not powered to detect significant associations with TmP/GFR (ratio of renal tubular maximum reabsorption rate of phosphate to glomerular filtration rate), growth and electrolyte supplementation. However, all patients with minimal aminoaciduria (≤2 elevated urinary amino acids) had normal TmP/GFR and no need for electrolyte supplementation. CONCLUSIONS This pilot study has shown that a larger study is feasible and may provide clinically useful data to change current practice. This should aim to establish whether the number of abnormal amino acids or the degree of abnormality is most significant in predicting clinically significant proximal tubulopathy.
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Morgan JE, Cleminson J, Atkin K, Stewart LA, Phillips RS. Systematic review of reduced therapy regimens for children with low risk febrile neutropenia. Support Care Cancer 2016; 24:2651-60. [PMID: 26757936 DOI: 10.1007/s00520-016-3074-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 01/03/2016] [Indexed: 12/01/2022]
Abstract
PURPOSE Reduced intensity therapy for children with low-risk febrile neutropenia may provide benefits to both patients and the health service. We have explored the safety of these regimens and the effect of timing of discharge. METHODS Multiple electronic databases, conference abstracts and reference lists were searched. Randomised controlled trials (RCT) and prospective observational cohorts examining the location of therapy and/or the route of administration of antibiotics in people younger than 18 years who developed low-risk febrile neutropenia following treatment for cancer were included. Meta-analysis using a random effects model was conducted. I (2) assessed statistical heterogeneity not due to chance. REGISTRATION PROSPERO (CRD42014005817). RESULTS Thirty-seven studies involving 3205 episodes of febrile neutropenia were included; 13 RCTs and 24 prospective observational cohorts. Four safety events (two deaths, two intensive care admissions) occurred. In the RCTs, the odds ratio for treatment failure (persistence, worsening or recurrence of fever/infecting organisms, antibiotic modification, new infections, re-admission, admission to critical care or death) with outpatient treatment was 0.98 (95% confidence interval (95%CI) 0.44-2.19, I (2) = 0 %) and with oral treatment was 1.05 (95%CI 0.74-1.48, I (2) = 0 %). The estimated risk of failure using outpatient therapy from all prospective data pooled was 11.2 % (95%CI 9.7-12.8 %, I (2) = 77.2 %) and using oral antibiotics was 10.5 % (95%CI 8.9-12.3 %, I (2) = 78.3 %). The risk of failure was higher when reduced intensity therapies were used immediately after assessment, with lower rates when these were introduced after 48 hours. CONCLUSIONS Reduced intensity therapy for specified groups is safe with low rates of treatment failure. Services should consider how these can be acceptably implemented.
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Miroddi M, Sterrantino C, Simonelli I, Ciminata G, Phillips RS, Calapai G. Risk of grade 3-4 diarrhea and mucositis in colorectal cancer patients receiving anti-EGFR monoclonal antibodies regimens: A meta-analysis of 18 randomized controlled clinical trials. Crit Rev Oncol Hematol 2015; 96:355-71. [DOI: 10.1016/j.critrevonc.2015.06.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 05/07/2015] [Accepted: 06/10/2015] [Indexed: 12/22/2022] Open
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Ridgel AL, Phillips RS, Walter BL, Discenzo FM, Loparo KA. Dynamic High-Cadence Cycling Improves Motor Symptoms in Parkinson's Disease. Front Neurol 2015; 6:194. [PMID: 26388836 PMCID: PMC4557094 DOI: 10.3389/fneur.2015.00194] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 08/20/2015] [Indexed: 02/03/2023] Open
Abstract
RATIONALE Individuals with Parkinson's disease (PD) often have deficits in kinesthesia. There is a need for rehabilitation interventions that improve these kinesthetic deficits. Forced (tandem) cycling at a high cadence improves motor function. However, tandem cycling is difficult to implement in a rehabilitation setting. OBJECTIVE To construct an instrumented, motored cycle and to examine if high cadence dynamic cycling promotes improvements in motor function. METHOD This motored cycle had two different modes: dynamic and static cycling. In dynamic mode, the motor maintained 75-85 rpm. In static mode, the rider determined the pedaling cadence. UPDRS Motor III and Timed Up and Go (TUG) were used to assess changes in motor function after three cycling sessions. RESULTS Individuals in the static group showed a lower cadence but a higher power, torque and heart rate than the dynamic group. UPDRS score showed a significant 13.9% improvement in the dynamic group and only a 0.9% improvement in the static group. There was also a 16.5% improvement in TUG time in the dynamic group but only an 8% improvement in the static group. CONCLUSION These findings show that dynamic cycling can improve PD motor function and that activation of proprioceptors with a high cadence but variable pattern may be important for motor improvements in PD.
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Ward EJ, Henry LM, Friend AJ, Wilkins S, Phillips RS. Nutritional support in children and young people with cancer undergoing chemotherapy. Cochrane Database Syst Rev 2015; 2015:CD003298. [PMID: 26301790 PMCID: PMC8752126 DOI: 10.1002/14651858.cd003298.pub3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND It is well documented that malnutrition is a common complication of paediatric malignancy and its treatment. Malnutrition can often be a consequence of cancer itself or a result of chemotherapy. Nutritional support aims to reverse malnutrition seen at diagnosis, prevent malnutrition associated with treatment and promote weight gain and growth. The most effective and safe forms of nutritional support in children and young people with cancer are not known. OBJECTIVES To determine the effects of any form of parenteral (PN) or enteral (EN) nutritional support, excluding vitamin supplementation and micronutrient supplementation, in children and young people with cancer undergoing chemotherapy and to determine the effect of the nutritional content of PN and EN. This is an update of a previous Cochrane review. SEARCH METHODS We searched the following databases for the initial review: CENTRAL (The Cochrane Library, Issue 2, 2009), MEDLINE (1950 to 2006), EMBASE (1974 to 2006), CINAHL (1982 to 2006), the National Research Register (2007) and Dissertations & Theses (2007). Experts in the field were also contacted for information on relevant trials. For this update, we searched the same electronic databases from 2006 to September 2013. We also scrutinised the reference lists of included articles to identify additional trials. SELECTION CRITERIA Randomised or quasi-randomised controlled trials comparing any form of nutritional support with another, or control, in children or young people with cancer undergoing chemotherapy. DATA COLLECTION AND ANALYSIS Two authors independently selected trials. At least two authors independently assessed quality and extracted data. We contacted trialists for missing information. MAIN RESULTS The current review included the eight trials from the initial review and six new trials which randomised 595 participants (< 21 years of age) with leukaemias or solid tumours undergoing chemotherapy. The trials were all of low quality with the exception of two of the trials looking at glutamine supplementation. One small trial found that compared to EN, PN significantly increased weight (mean difference (MD) 4.12, 95% CI 1.91 to 6.33), serum albumin levels (MD 0.70, 95% CI 0.14 to 1.26), calorie intake (MD 22.00, 95% CI 5.12 to 38.88) and protein intake (MD 0.80, 95% CI 0.45 to 1.15). One trial comparing peripheral PN and EN with central PN found that mean daily weight gain (MD -27.00, 95% CI -43.32 to -10.68) and energy intake (MD -15.00, 95% CI -26.81 to -3.19) were significantly less for the peripheral PN and EN group, whereas mean change in serum albumin was significantly greater for that group (MD 0.47, 95% CI 0.13 to 0.81, P = 0.008). Another trial with few participants found an increase in mean energy intake (% recommended daily amount) in children fed an energy dense feed compared to a standard calorie feed (MD +28%, 95% CI 17% to 39%). Three studies looked at glutamine supplementation. The evidence suggesting that glutamine reduces severity of mucositis was not statistically significant in two studies (RR 0.64, 95% CI 0.19 to 2.2 and RR 0.85, 95% CI 0.66 to 1.1) and differences in reduction of infection rates were also not significant in two studies (RR 1.0, 95% CI 0.72 to 1.4 and RR 0.98, 95% CI 0.63 to 1.51). Only one study compared olive oil based PN to standard lipid containing PN. Despite similar calorie contents in both feeds, the standard lipid formula lead to greater weight gain (MD -0.34 z-scores, 95% CI -0.68 to 0.00). A single study compared standard EN with fructooligosaccharide containing EN. There was no difference in weight gain between groups (mean difference -0.12, 95% CI -0.57 to 0.33), with adverse effects (nausea) occurring equally between the groups (RR 0.92, 95% CI 0.48 to 1.74). AUTHORS' CONCLUSIONS There is limited evidence from individual trials to suggest that PN is more effective than EN in well-nourished children and young people with cancer undergoing chemotherapy. The evidence for other methods of nutritional support remains unclear. Limited evidence suggests an energy dense feed increases mean daily energy intake and has a positive effect on weight gain. Evidence suggesting glutamine supplementation reduces incidence and severity of mucositis, infection rates and length of hospital stay is not statistically significant. Further research, incorporating larger sample sizes and rigorous methodology utilising valid and reliable outcome measures, is essential.
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Phillips RS, Scott B, Carter SJ, Taylor M, Peirce E, Davies P, Maconochie IK. Systematic review and meta-analysis of outcomes after cardiopulmonary arrest in childhood. PLoS One 2015; 10:e0130327. [PMID: 26107958 PMCID: PMC4479568 DOI: 10.1371/journal.pone.0130327] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 05/19/2015] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Cardiopulmonary arrest in children is an uncommon event, and often fatal. Resuscitation is often attempted, but at what point, and under what circumstances do continued attempts to re-establish circulation become futile? The uncertainty around these questions can lead to unintended distress to the family and to the resuscitation team. OBJECTIVES To define the likely outcomes of cardiopulmonary resuscitation in children, within different patient groups, related to clinical features. DATA SOURCES MEDLINE, MEDLINE in-Process & Other non-Indexed Citations, EMBASE, Cochrane database of systematic reviews and Cochrane central register of trials, Database of Abstracts of Reviews of Effects (DARE), the Health Technology Assessment database, along with reference lists of relevant systematic reviews and included articles. STUDY ELIGIBILITY CRITERIA Prospective cohort studies which derive or validate a clinical prediction model of outcome following cardiopulmonary arrest. PARTICIPANTS AND INTERVENTIONS Children or young people (aged 0 - 18 years) who had cardiopulmonary arrest and received an attempt at resuscitation, excluding resuscitation at birth. STUDY APPRAISAL AND SYNTHESIS METHODS Risk of bias assessment developed the Hayden system for non-randomised studies and QUADAS2 for decision rules. Synthesis undertaken by narrative, and random effects meta-analysis with the DerSimonian-Laird estimator. RESULTS More than 18,000 episodes in 16 data sets were reported. Meta-analysis was possible for survival and one neurological outcome; others were reported too inconsistently. In-hospital patients (average survival 37.2% (95% CI 23.7 to 53.0%)) have a better chance of survival following cardiopulmonary arrest than out-of-hospital arrests (5.8% (95% CI 3.9% to 8.6%)). Better neurological outcome was also seen, but data were too scarce for meta-analysis (17% to 71% 'good' outcomes, compared with 2.8% to 3.2%). LIMITATION Lack of consistent outcome reporting and short-term neurological outcome measures limited the strength of conclusions that can be drawn from this review. CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS There is a need to collaboratively, prospectively, collect potentially predictive data on these rare events to understand more clearly the predictors of survival and long-term neurological outcome. SYSTEMATIC REVIEW REGISTRATION NUMBER PROSPERO 2013:CRD42013005102.
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Nealon CM, Musa MM, Patel JM, Phillips RS. Controlling Substrate Specificity and Stereospecificity of Alcohol Dehydrogenases. ACS Catal 2015. [DOI: 10.1021/cs501457v] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Haeusler GM, Phillips RS, Lehrnbecher T, Thursky KA, Sung L, Ammann RA. Core outcomes and definitions for pediatric fever and neutropenia research: a consensus statement from an international panel. Pediatr Blood Cancer 2015; 62:483-9. [PMID: 25446628 DOI: 10.1002/pbc.25335] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 10/03/2014] [Indexed: 11/05/2022]
Abstract
BACKGROUND There are no specific recommendations for the design and reporting of studies of children with fever and neutropenia (FN). As a result, there is marked heterogeneity in the variables and outcomes that are reported and new definitions continue to emerge. These inconsistencies hinder the ability of researchers and clinicians to compare, contrast and combine results. The objective was to achieve expert consensus on a core set of variables and outcomes that should be measured and reported, as a minimum, in pediatric FN studies. PROCEDURE The Delphi method was used to achieve consensus among an international group of clinicians, pharmacists, researchers, and patient representatives. Four surveys focusing on (i) the identification of a core set of variables and outcomes; and (ii) definitions of these variables and outcomes, were administered electronically. Consensus was predefined as more than 80% agreement on any statement. RESULTS There were forty-five survey participants and the response rate ranged between 84 and 96%. There was consensus on eight core variables and 10 core outcomes that should be collected and reported in all studies of children with FN. Consensus definitions were identified for all of the core outcomes. CONCLUSION Using the Delphi method, expert consensus on a set of core variables and outcomes, and their corresponding definitions, was achieved. These core sets represent the minimum that should be collected and reported in all studies of children with FN. This will promote collaboration and ensure consistency and comparability between studies.
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Kadirvelraj R, Sennett NC, Custer GS, Phillips RS, Wood ZA. Correction to Hysteresis and Negative Cooperativity in Human UDP-Glucose Dehydrogenase. Biochemistry 2015. [DOI: 10.1021/bi501527p] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Phillips RS. Chemistry and diversity of pyridoxal-5'-phosphate dependent enzymes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1167-74. [PMID: 25615531 DOI: 10.1016/j.bbapap.2014.12.028] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/22/2014] [Accepted: 12/23/2014] [Indexed: 12/01/2022]
Abstract
Pyridoxal-5'-phosphate (PLP) is a versatile cofactor that enzymes use to catalyze a wide variety of reactions of amino acids, including transamination, decarboxylation, racemization, β- and γ-eliminations and substitutions, retro-aldol and Claisen reactions. These reactions depend on the ability of PLP to stabilize, to a varying degree, α-carbanionic intermediates. Furthermore, oxidative decarboxylations and rearrangements suggest that PLP can stabilize radical intermediates as well. The reaction mechanisms of two PLP-dependent enzymes are discussed, kynureninase and tyrosine phenol-lyase (TPL). Kynureninase catalyzes a retro-Claisen reaction of kynurenine to give anthranilate and alanine. The key step, hydration of the γ-carbonyl, is assisted by acid-base catalysis with the phosphate of the PLP, mediated by a conserved tyrosine, and an oxyanion hole. TPL catalyzes the reversible elimination of phenol, a poor leaving group, from l-tyrosine. In TPL, the Cβ-Cγ bond cleavage is accelerated by ground state strain from the bending of the substrate ring out of the plane with the Cβ-Cγ bond. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.
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Abdelgadir IS, Phillips RS, Moncreiff MP, Lumsden JL. Video-laryngoscopy versus direct laryngoscopy for tracheal intubation in children (excluding neonates). Cochrane Database Syst Rev 2014. [DOI: 10.1002/14651858.cd011413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Jakes AD, Marec-Berard P, Phillips RS, Stark DP. Critical Review of Clinical Practice Guidelines for Fertility Preservation in Teenagers and Young Adults with Cancer. J Adolesc Young Adult Oncol 2014; 3:144-152. [PMID: 25538859 PMCID: PMC4270154 DOI: 10.1089/jayao.2014.0032] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Purpose: The 5-year survival of teenagers and young adults (TYAs; 13-24 years old) with cancer has continued to rise, but as a result more patients experience late effects of treatment, such as infertility. Advice regarding fertility preservation in relation to cancer is provided in numerous clinical practice guidelines, but the rigor of their development is unclear. Methods: A systematic search was undertaken for clinical practice guidelines regarding fertility preservation in TYAs with cancer. All guidelines were reviewed according to the Appraisal of Guidelines for Research and Evaluation (AGREE-II) criteria. Five out of 13 identified guidelines scored over 75% in the "rigor of development" section and were further appraised. Content, scope, and consistencies between recommendations were also examined. Results: All five of the reviewed guidelines encouraged oncologists to have discussions with their patients about potential fertility issues associated with treatment and available fertility preservation methods. The cryopreservation of sperm, oocytes, and embryos were all recommended as first-line interventions in postpubertal patients. Recommendations surrounding pre- or peripubescent adolescents were few, with many techniques only recommended as part of a clinical trial. The risk of subfertility associated with different treatment regimens was poorly described. Conclusions: The methodology and development of guidelines describing fertility preservation in TYA cancer patients varied greatly. Methodological quality did not clearly influence key recommendations. Those involved with the development of guidelines are encouraged to clearly define their development methods to allow users to be confident of the quality.
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Morgan JE, Stewart L, Phillips RS. Protocol for a systematic review of reductions in therapy for children with low-risk febrile neutropenia. Syst Rev 2014; 3:119. [PMID: 25336249 PMCID: PMC4234526 DOI: 10.1186/2046-4053-3-119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 10/02/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Febrile neutropenia is a common complication of therapy in children with cancer. Some patients are at low risk of complications, and research has considered reduction in therapy for these patients. A previous systematic review broadly considered whether outpatient treatment and oral antibiotics were safe in this context and concluded that this was likely to be the case. Since that review, there has been further research in this area. Therefore, we aim to provide a more robust answer to these questions and to additionally explore whether the exact timing of discharge, including entirely outpatient treatment, has an impact on outcomes. METHODS/DESIGN The search will cover MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, CDSR, CENTRAL, LILACS, HTA and DARE. A full search strategy is provided. Key conference proceedings and reference lists of included papers will be hand searched. Prominent authors/clinicians in the field will be contacted. We will include randomised and quasi-randomised controlled trials along with prospective single-arm studies that examine the location of therapy and/or the route of administration of antibiotics in children or young adults (aged less than 18 years) who attend paediatric services with fever and neutropenia due to treatment for cancer and are assessed to be at low risk of medical complications. Studies will be screened and data extracted by one researcher and independently checked by a second. All studies will be critically appraised using tools appropriate to the study design. Data from randomised controlled trials (RCTs) will be combined to provide comparative estimates of treatment failure, safety and adequacy. Information from quasi-randomised trials and single-arm studies will provide further data on the safety and adequacy of regimes. Random effects meta-analysis will be used to combine studies. A detailed analysis plan, including assessment of heterogeneity and publication bias, is provided. DISCUSSION This study will aim to specifically define the features of a low-risk strategy that will maintain levels of safety and adequacy equivalent to those of traditional treatments. This will both inform the development of services and provide patients and families with data to help them make an informed decision about care. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42014005817.
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Cutler HG, Jacyno JM, Phillips RS, VonTersch RL, Cole PD, Montemurro N. Cyclonerodiol from a Novel Source,Trichoderma koningii: Plant Growth Regulatory Activity. ACTA ACUST UNITED AC 2014. [DOI: 10.1080/00021369.1991.10870569] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Patel JM, Musa MM, Rodriguez L, Sutton DA, Popik VV, Phillips RS. Mutation of Thermoanaerobacter ethanolicus secondary alcohol dehydrogenase at Trp-110 affects stereoselectivity of aromatic ketone reduction. Org Biomol Chem 2014; 12:5905-10. [PMID: 24984815 DOI: 10.1039/c4ob00794h] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Alcohol dehydrogenases (ADHs) are enzymes that catalyze the reversible reduction of carbonyl compounds to their corresponding alcohols. We have been studying a thermostable, nicotinamide-adenine dinucleotide phosphate (NADP(+))-dependent, secondary ADH from Thermoanaerobacter ethanolicus (TeSADH). In the current work, we expanded our library of TeSADH and adopted the site-saturation mutagenesis approach in creating a comprehensive mutant library at W110. We used phenylacetone as a model substrate to study the effectiveness of our library because this substrate showed low enantioselectivity in our previous work when reduced using W110A TeSADH. Five of the newly designed W110 mutants reduced phenylacetone at >99.9% ee, and two of these mutants exhibit an enantiomeric ratio (E-value) of over 100. These five mutants also reduced 1-phenyl-2-butanone and 4-phenyl-2-butanone to their corresponding (S)-configured alcohols in >99.9% ee. These new mutants of TeSADH will likely have synthetic utility for reduction of aromatic ketones in the future.
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Faleev NG, Zakomirdina LN, Vorob'ev MM, Tsvetikova MA, Gogoleva OI, Demidkina TV, Phillips RS. A straightforward kinetic evidence for coexistence of "induced fit" and "selected fit" in the reaction mechanism of a mutant tryptophan indole lyase Y72F from Proteus vulgaris. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1844:1860-7. [PMID: 25084024 DOI: 10.1016/j.bbapap.2014.07.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/30/2014] [Accepted: 07/21/2014] [Indexed: 11/25/2022]
Abstract
The interaction of the mutant tryptophan indole-lyase (TIL) from Proteus vulgaris Y72F with the transition state analogue, oxindolyl-l-alanine (OIA), with the natural substrate, l-tryptophan, and with a substrate S-ethyl-l-cysteine was examined. In the case of wild-type enzyme these reactions are described by the same kinetic scheme where binding of holoenzyme with an amino acid, leading to reversible formation of an external aldimine, proceeds very fast, while following transformations, leading finally to reversible formation of a quinonoid intermediate proceed with measureable rates. Principally the same scheme ("induced fit") is realized in the case of mutant Y72F enzyme reaction with OIA. For the reaction of mutant enzyme with l-Trp at lower concentrations of the latter a principally different kinetic scheme is observed. This scheme suggests that binding of the substrate and formation of the quinonoid intermediate are at fast equilibrium, while preceding conformational changes of the holoenzyme proceed with measureable rates ("selected fit"). For the reaction with S-ethyl-l-cysteine the observed concentration dependence of kobs agrees with the realization of both kinetic schemes, the "selected fit" becoming predominant at lower concentrations of substrate, the "induced fit"- at higher ones. In the reaction with S-ethyl-l-cysteine the formation of the quinonoid intermediate proceeds slower than does catalytic α,β-elimination of ethylthiol from S-ethyl-l-cysteine, and consequently does not play a considerable role in the catalysis, which may be effected by a concerted E2 mechanism.
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Venkatesh M, Mukherjee S, Wang H, Li H, Sun K, Benechet AP, Qiu Z, Maher L, Redinbo MR, Phillips RS, Fleet JC, Kortagere S, Mukherjee P, Fasano A, Le Ven J, Nicholson JK, Dumas ME, Khanna KM, Mani S. Symbiotic bacterial metabolites regulate gastrointestinal barrier function via the xenobiotic sensor PXR and Toll-like receptor 4. Immunity 2014; 41:296-310. [PMID: 25065623 DOI: 10.1016/j.immuni.2014.06.014] [Citation(s) in RCA: 647] [Impact Index Per Article: 64.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 05/30/2014] [Indexed: 02/07/2023]
Abstract
Intestinal microbial metabolites are conjectured to affect mucosal integrity through an incompletely characterized mechanism. Here we showed that microbial-specific indoles regulated intestinal barrier function through the xenobiotic sensor, pregnane X receptor (PXR). Indole 3-propionic acid (IPA), in the context of indole, is a ligand for PXR in vivo, and IPA downregulated enterocyte TNF-α while it upregulated junctional protein-coding mRNAs. PXR-deficient (Nr1i2(-/-)) mice showed a distinctly "leaky" gut physiology coupled with upregulation of the Toll-like receptor (TLR) signaling pathway. These defects in the epithelial barrier were corrected in Nr1i2(-/-)Tlr4(-/-) mice. Our results demonstrate that a direct chemical communication between the intestinal symbionts and PXR regulates mucosal integrity through a pathway that involves luminal sensing and signaling by TLR4.
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Phillips RS, Demidkina TV, Faleev NG. The role of substrate strain in the mechanism of the carbon-carbon lyases. Bioorg Chem 2014; 57:198-205. [PMID: 25035301 DOI: 10.1016/j.bioorg.2014.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Revised: 06/09/2014] [Accepted: 06/11/2014] [Indexed: 12/24/2022]
Abstract
The carbon-carbon lyases, tryptophan indole lyase (TIL) and tyrosine phenol-lyase (TPL) are bacterial enzymes which catalyze the reversible elimination of indole and phenol from l-tryptophan and l-tyrosine, respectively. These PLP-dependent enzymes show high sequence homology (∼40% identity) and both form homotetrameric structures. Steady state kinetic studies with both enzymes show that an active site base is essential for activity, and α-deuterated substrates exhibit modest primary isotope effects on kcat and kcat/Km, suggesting that substrate deprotonation is partially rate-limiting. Pre-steady state kinetics with TPL and TIL show rapid formation of external aldimine intermediates, followed by deprotonation to give quinonoid intermediates absorbing at about 500nm. In the presence of phenol and indole analogues, 4-hydroxypyridine and benzimidazole, the quinonoid intermediates of TPL and TIL decay to aminoacrylate intermediates, with λmax at about 340nm. Surprisingly, there are significant kinetic isotope effects on both formation and subsequent decay of the quinonoid intermediates when α-deuterated substrates are used. The crystal structure of TPL with a bound competitive inhibitor, 4-hydroxyphenylpropionate, identified several essential catalytic residues: Tyr-71, Thr-124, Arg-381, and Phe-448. The active sites of TIL and TPL are highly conserved with the exceptions of these residues: Arg-381(TPL)/Ile-396 (TIL); Thr-124 (TPL)/Asp-137 (TIL), and Phe-448 (TPL)/His-463 (TIL). Mutagenesis of these residues results in dramatic decreases in catalytic activity without changing substrate specificity. The conserved tyrosine, Tyr-71 (TPL)/Tyr-74 (TIL) is essential for elimination activity with both enzymes, and likely plays a role as a proton donor to the leaving group. Mutation of Arg-381 and Thr-124 of TPL to alanine results in very low but measurable catalytic activity. Crystallography of Y71F and F448H TPL with 3-fluoro-l-tyrosine bound demonstrated that there are two quinonoid structures, relaxed and tense. In the relaxed structure, the substrate aromatic ring is in plane with the Cβ-Cγ bond, but in the tense structure, the substrate aromatic ring is about 20° out of plane with the Cβ-Cγ bond. In the tense structure, hydrogen bonds are formed between the substrate OH and the guanidinium of Arg-381 and the OH of Thr-124, and the phenyl rings of Phe-448 and 449 provide steric strain. Based on the effects of mutagenesis, the substrate strain is estimated to contribute about 10(8) to TPL catalysis. Thus, the mechanisms of TPL and TIL require both substrate strain and acid/base catalysis, and substrate strain is probably responsible for the very high substrate specificity of TPL and TIL.
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Naqvi AZ, Hasturk H, Mu L, Phillips RS, Davis RB, Halem S, Campos H, Goodson JM, Van Dyke TE, Mukamal KJ. Docosahexaenoic Acid and Periodontitis in Adults: A Randomized Controlled Trial. J Dent Res 2014; 93:767-73. [PMID: 24970858 DOI: 10.1177/0022034514541125] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 08/03/2014] [Indexed: 01/08/2023] Open
Abstract
Periodontitis is a common chronic inflammatory disease initiated by bacteria, resulting in bone resorption, tooth loss, and systemic inflammation. Long-chain omega-3 fatty acids such as docosahexaenoic acid (DHA) reduce periodontitis in animals. We aimed to determine whether DHA supplementation with low-dose aspirin would reduce periodontitis in humans. We conducted a double-blind placebo-controlled parallel trial lasting 3 mo. Fifty-five adults with moderate periodontitis were randomized to 2,000 mg of DHA or identical soy/corn oil capsules. All participants received 81 mg of aspirin but received no other treatments. We analyzed the primary outcome of per-pocket change in pocket depth using mixed models among teeth with pocket depth ≥5 mm. Secondary outcomes assessed with generalized estimating equations included gingival index, plaque index, and bleeding on probing. Gingival crevicular fluid samples were analyzed for changes in high-sensitivity C-reactive protein (hsCRP) and interleukins 6 and 1β (IL-6 and IL-1β). Plasma was analyzed for changes in systemic inflammatory markers, including hsCRP. We confirmed adherence with erythrocyte fatty acid measurement. Forty-six participants completed the trial. While similar at baseline, the proportion of DHA in red blood cell plasma membranes increased from 3.6% ± 0.9% to 6.2% ± 1.6% in the intervention group but did not change among controls. DHA supplementation decreased mean pocket depth (-0.29 ± 0.13; p = .03) and gingival index (-0.26 ± 0.13; p = .04). Plaque index and bleeding on probing did not change. Significant adjusted differences were found between DHA and control for both gingival crevicular fluid hsCRP (-5.3 ng/mL, standard error [SE] = 2.4, p = .03) and IL-1β (-20.1 pg/mL, SE = 8.2, p = .02) but not IL-6 (0.02 pg/mL, SE = 0.71, p = .98) or systemic hsCRP (-1.19 mg/L, SE = 0.90, p = .20). In this randomized controlled trial, aspirin-triggered DHA supplementation significantly improved periodontal outcomes in people with periodontitis, indicating its potential therapeutic efficacy (clinicaltrials.gov NCT01976806).
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Phillips RS, Ridgel AL. Individuals With Parkinson’S Disease Benefit From A Single Bout Of Dynamic Cycling. Med Sci Sports Exerc 2014. [DOI: 10.1249/01.mss.0000496228.51228.56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Redman MG, Ward EJ, Phillips RS. The efficacy and safety of probiotics in people with cancer: a systematic review. Ann Oncol 2014; 25:1919-1929. [PMID: 24618152 DOI: 10.1093/annonc/mdu106] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Probiotics are living microorganisms that are generally thought of as being beneficial to the recipient. They have been shown to be effective in people with acute infectious diarrhoea, and cost-effective in antibiotic-associated diarrhoea. Probiotics may have a role in people with cancer, as various cancer treatments often lead to diarrhoea. However, as people with cancer are often immunocompromised, it is important to assess for adverse events (AEs) such as infection, which could potentially be a consequence of deliberate ingestion of living microorganisms. DESIGN A systematic review was carried out to collect, analyse and synthesise all available data on the efficacy and safety of probiotics in people with cancer (PROSPERO registration: CRD42012003454). Randomised, controlled trials, identified through screening multiple databases and grey literature, were included for analysing efficacy, while all studies were included for the analysis of safety of probiotics. Primary outcomes were the reduction in duration, severity and incidence of antibiotic-associated diarrhoea and chemotherapy-associated diarrhoea, and AEs, especially probiotic-associated infection. Where possible, data were combined for meta-analysis by a random-effects model, assessing causes of heterogeneity, including differences in strains, dosage and patient characteristics. RESULTS Eleven studies (N = 1557 participants) were included for assessing efficacy. Results show that probiotics may reduce the severity and frequency of diarrhoea in patients with cancer and may reduce the requirement for anti-diarrhoeal medication, but more studies are needed to assess the true effect. For example comparing probiotic use to control 25 groups on effect on Common Toxicity Criteria ≥2 grade diarrhoea, odds ratio (OR) = 0.32 [95% confidence interval (CI) of 0.13-0.79; P = 0.01]. Seventeen studies (N = 1530) were included in the safety analysis. Five case reports showed probiotic-related bacteraemia/fungaemia/positive blood cultures. CONCLUSIONS Probiotics may be a rare cause of sepsis. Further evidence needs to be collated to determine whether probiotics provide a significant overall benefit for people with cancer.
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Patel JM, Phillips RS. Effects of Hydrostatic Pressure on Stereospecificity of Secondary Alcohol Dehydrogenase from Thermoanaerobacter Ethanolicus Support the Role of Solvation in Enantiospecificity. ACS Catal 2014. [DOI: 10.1021/cs4010997] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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