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Waterbirth: a national retrospective cohort study of factors associated with its use among women in England. BMC Pregnancy Childbirth 2021; 21:256. [PMID: 33771115 PMCID: PMC8004456 DOI: 10.1186/s12884-021-03724-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 03/16/2021] [Indexed: 11/15/2022] Open
Abstract
Background Waterbirth is widely available in English maternity settings for women who are not at increased risk of complications during labour. Immersion in water during labour is associated with a number of maternal benefits. However for birth in water the situation is less clear, with conclusive evidence on safety lacking and little known about the characteristics of women who give birth in water. This retrospective cohort study uses electronic data routinely collected in the course of maternity care in England in 2015–16 to describe the proportion of births recorded as having occurred in water, the characteristics of women who experienced waterbirth and the odds of key maternal and neonatal complications associated with giving birth in water. Methods Data were obtained from three population level electronic datasets linked together for the purposes of a national audit of maternity care. The study cohort included women who had no risk factors requiring them to give birth in an obstetric unit according to national guidelines. Multivariate logistic regression models were used to examine maternal (postpartum haemorrhage of 1500mls or more, obstetric anal sphincter injury (OASI)) and neonatal (Apgar score less than 7, neonatal unit admission) outcomes associated with waterbirth. Results 46,088 low and intermediate risk singleton term spontaneous vaginal births in 35 NHS Trusts in England were included in the analysis cohort. Of these 6264 (13.6%) were recorded as having occurred in water. Waterbirth was more likely in older women up to the age of 40 (adjusted odds ratio (adjOR) for age group 35–39 1.27, 95% confidence interval (1.15,1.41)) and less common in women under 25 (adjOR 18–24 0.76 (0.70, 0.82)), those of higher parity (parity ≥3 adjOR 0.56 (0.47,0.66)) or who were obese (BMI 30–34.9 adjOR 0.77 (0.70,0.85)). Waterbirth was also less likely in black (adjOR 0.42 (0.36, 0.51)) and Asian (adjOR 0.26 (0.23,0.30)) women and in those from areas of increased socioeconomic deprivation (most affluent versus least affluent areas adjOR 0.47 (0.43, 0.52)). There was no association between delivery in water and low Apgar score (adjOR 0.95 (0.66,1.36)) or incidence of OASI (adjOR 1.00 (0.86,1.16)). There was an association between waterbirth and reduced incidence of postpartum haemorrhage (adjOR 0.68 (0.51,0.90)) and neonatal unit admission (adjOR 0.65 (0.53,0.78)). Conclusions In this large observational cohort study, there was no association between waterbirth and specific adverse outcomes for either the mother or the baby. There was evidence that white women from higher socioeconomic backgrounds were more likely to be recorded as giving birth in water. Maternity services should focus on ensuring equitable access to waterbirth. Supplementary Information The online version contains supplementary material available at 10.1186/s12884-021-03724-6.
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A novel multimodal treatment strategy for cancer cachexia; rationale and motivation for the MENAC (Multimodal – Exercise, Nutrition and Anti-inflammatory medication for Cachexia) trial. Ann Oncol 2017. [DOI: 10.1093/annonc/mdx388.068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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OR45: Body Composition in Non-Small Cell Lung Cancer (Nsclc) Patients with Cachexia and Improved Anorexia-Cachexia Symptoms: Anamorelin Phase 3 Trials Pooled Analysis. Clin Nutr 2016. [DOI: 10.1016/s0261-5614(16)30284-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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SUN-P086: Weight Loss and Survival in Advanced Cancer in Relation to Inadequate Energy Intake. Clin Nutr 2016. [DOI: 10.1016/s0261-5614(16)30429-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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1606 Nutritional support in cancer - more formal recommendations are required. Eur J Cancer 2015. [DOI: 10.1016/s0959-8049(16)30694-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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1603 ROMANA 3: A safety extension study of anamorelin in advanced non-small cell lung cancer (NSCLC) patients with cachexia. Eur J Cancer 2015. [DOI: 10.1016/s0959-8049(16)30691-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Nutritional Support in Cancer–Survey Results Identify a Need for More Education. Ann Oncol 2014. [DOI: 10.1093/annonc/mdu356.54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Anamorelin for the Treatment of Cancer Anorexia-Cachexia in Nsclc: Results from the Phase 3 Studies Romana 1 and 2. Ann Oncol 2014. [DOI: 10.1093/annonc/mdu438.62] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Early recognition of malnutrition and cachexia in the cancer patient: a position paper of a European School of Oncology Task Force. Ann Oncol 2014; 25:1492-9. [DOI: 10.1093/annonc/mdu085] [Citation(s) in RCA: 203] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Validation of the Consensus-Definition for Cancer Cachexia and evaluation of a classification model--a study based on data from an international multicentre project (EPCRC-CSA). Ann Oncol 2014; 25:1635-42. [PMID: 24562443 DOI: 10.1093/annonc/mdu086] [Citation(s) in RCA: 164] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Weight loss limits cancer therapy, quality of life and survival. Common diagnostic criteria and a framework for a classification system for cancer cachexia were recently agreed upon by international consensus. Specific assessment domains (stores, intake, catabolism and function) were proposed. The aim of this study is to validate this diagnostic criteria (two groups: model 1) and examine a four-group (model 2) classification system regarding these domains as well as survival. PATIENTS AND METHODS Data from an international patient sample with advanced cancer (N = 1070) were analysed. In model 1, the diagnostic criteria for cancer cachexia [weight loss/body mass index (BMI)] were used. Model 2 classified patients into four groups 0-III, according to weight loss/BMI as a framework for cachexia stages. The cachexia domains, survival and sociodemographic/medical variables were compared across models. RESULTS Eight hundred and sixty-one patients were included. Model 1 consisted of 399 cachectic and 462 non-cachectic patients. Cachectic patients had significantly higher levels of inflammation, lower nutritional intake and performance status and shorter survival. In model 2, differences were not consistent; appetite loss did not differ between group III and IV, and performance status not between group 0 and I. Survival was shorter in group II and III compared with other groups. By adding other cachexia domains to the model, survival differences were demonstrated. CONCLUSION The diagnostic criteria based on weight loss and BMI distinguish between cachectic and non-cachectic patients concerning all domains (intake, catabolism and function) and is associated with survival. In order to guide cachexia treatment a four-group classification model needs additional domains to discriminate between cachexia stages.
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PP095-SUN COMPUTED TOMOGRAPHY AND BIOELECTRICAL IMPEDANCE: RELEVANCE FOR BODY COMPOSITION ASSESSMENT IN ONCOLOGY. Clin Nutr 2013. [DOI: 10.1016/s0261-5614(13)60140-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Guidelines for perioperative care in elective colonic surgery: Enhanced Recovery After Surgery (ERAS(®)) Society recommendations. World J Surg 2013; 37:259-84. [PMID: 23052794 DOI: 10.1007/s00268-012-1772-0] [Citation(s) in RCA: 804] [Impact Index Per Article: 73.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Guidelines for perioperative care in elective colonic surgery: Enhanced Recovery After Surgery (ERAS®) Society recommendations. Clin Nutr 2012; 31:783-800. [PMID: 23099039 DOI: 10.1016/j.clnu.2012.08.013] [Citation(s) in RCA: 441] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 08/19/2012] [Indexed: 12/16/2022]
Abstract
BACKGROUND This review aims to present a consensus for optimal perioperative care in colonic surgery and to provide graded recommendations for items for an evidenced-based enhanced perioperative protocol. METHODS Studies were selected with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohorts. For each item of the perioperative treatment pathway, available English-language literature was examined, reviewed and graded. A consensus recommendation was reached after critical appraisal of the literature by the group. RESULTS For most of the protocol items, recommendations are based on good-quality trials or meta-analyses of good-quality trials (quality of evidence and recommendations according to the GRADE system). CONCLUSIONS Based on the evidence available for each item of the multimodal perioperative-care pathway, the Enhanced Recovery After Surgery (ERAS) Society, International Association for Surgical Metabolism and Nutrition (IASMEN) and European Society for Clinical Nutrition and Metabolism (ESPEN) present a comprehensive evidence-based consensus review of perioperative care for colonic surgery.
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QUALITY AND SAFETY OF ART THERAPIES. Hum Reprod 2012. [DOI: 10.1093/humrep/27.s2.86] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Is there a genetic cause for cancer cachexia? - a clinical validation study in 1797 patients. Br J Cancer 2011; 105:1244-51. [PMID: 21934689 PMCID: PMC3208484 DOI: 10.1038/bjc.2011.323] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Cachexia has major impact on cancer patients' morbidity and mortality. Future development of cachexia treatment needs methods for early identification of patients at risk. The aim of the study was to validate nine single-nucleotide polymorphisms (SNPs) previously associated with cachexia, and to explore 182 other candidate SNPs with the potential to be involved in the pathophysiology. METHOD A total of 1797 cancer patients, classified as either having severe cachexia, mild cachexia or no cachexia, were genotyped. RESULTS After allowing for multiple testing, there was no statistically significant association between any of the SNPs analysed and the cachexia groups. However, consistent with prior reports, two SNPs from the acylpeptide hydrolase (APEH) gene showed suggestive statistical significance (P=0.02; OR, 0.78). CONCLUSION This study failed to detect any significant association between any of the SNPs analysed and cachexia; although two SNPs from the APEH gene had a trend towards significance. The APEH gene encodes the enzyme APEH, postulated to be important in the endpoint of the ubiquitin system and thus the breakdown of proteins into free amino acids. In cachexia, there is an extensive breakdown of muscle proteins and an increase in the production of acute phase proteins in the liver.
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Lenalidomide in solid tumor patients with inflammatory cancer cachexia: A multicenter, randomized, double-blind, proof-of-concept study of fixed dose or CRP-response-guided dose or placebo. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.tps239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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271 Genotyping – does it matter in clinical practice for pain and cachexia? EJC Suppl 2009. [DOI: 10.1016/s1359-6349(09)70228-9] [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] Open
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274 Treatment of cachexia-a preventive or symptomatic approach? EJC Suppl 2009. [DOI: 10.1016/s1359-6349(09)70230-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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ESPEN Guidelines on Parenteral Nutrition: surgery. Clin Nutr 2009; 28:378-86. [PMID: 19464088 DOI: 10.1016/j.clnu.2009.04.002] [Citation(s) in RCA: 373] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Accepted: 04/01/2009] [Indexed: 12/15/2022]
Abstract
In modern surgical practice it is advisable to manage patients within an enhanced recovery protocol and thereby have them eating normal food within 1-3 days. Consequently, there is little room for routine perioperative artificial nutrition. Only a minority of patients may benefit from such therapy. These are predominantly patients who are at risk of developing complications after surgery. The main goals of perioperative nutritional support are to minimize negative protein balance by avoiding starvation, with the purpose of maintaining muscle, immune, and cognitive function and to enhance postoperative recovery. Several studies have demonstrated that 7-10 days of preoperative parenteral nutrition improves postoperative outcome in patients with severe undernutrition who cannot be adequately orally or enterally fed. Conversely, its use in well-nourished or mildly undernourished patients is associated with either no benefit or with increased morbidity. Postoperative parenteral nutrition is recommended in patients who cannot meet their caloric requirements within 7-10 days orally or enterally. In patients who require postoperative artificial nutrition, enteral feeding or a combination of enteral and supplementary parenteral feeding is the first choice. The main consideration when administering fat and carbohydrates in parenteral nutrition is not to overfeed the patient. The commonly used formula of 25 kcal/kg ideal body weight furnishes an approximate estimate of daily energy expenditure and requirements. Under conditions of severe stress requirements may approach 30 kcal/kg ideal body weights. In those patients who are unable to be fed via the enteral route after surgery, and in whom total or near total parenteral nutrition is required, a full range of vitamins and trace elements should be supplemented on a daily basis.
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Randomized clinical trial of the effect of postoperative intravenous fluid restriction on recovery after elective colorectal surgery. Br J Surg 2007; 93:1469-74. [PMID: 17078116 DOI: 10.1002/bjs.5593] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Use of intravenous fluids is an important part of perioperative management. The aim of this study was to compare outcome following administration of restricted or standard postoperative intravenous fluids and sodium in patients undergoing elective colorectal surgery. METHODS Eighty patients were randomized to restricted fluids (less than 2 litres water and 77 mmol sodium for 24 h after surgery) or a standard postoperative fluid regimen (3 litres water and 154 mmol sodium per day for as long as necessary). The primary endpoint was hospital stay. RESULTS The median (i.q.r.) total intravenous fluid intake in the restricted group was 4.50 (4.00-5.62) litres compared with 8.75 (8.00-9.80) litres in the standard group (P < 0.001). Intravenous sodium intake was also significantly less in the restricted group (229 (131-332) versus 560 (477-667) mmol; P < 0.001). There was no difference in median time to first flatus (2.9 versus 2.9 days; hazard ratio (HR) 0.85 (95 per cent confidence interval (c.i.) 0.54 to 1.32); P = 0.466) or first bowel motion (4.7 versus 4.9 days; HR 1.06 (95 per cent c.i. 0.68 to 1.65); P = 0.802) between the restricted and standard groups, or in median hospital stay (7.2 versus 7.2 days; HR 1.03 (95 per cent c.i. 0.66 to 1.61); P = 0.902). CONCLUSION Restriction of postoperative intravenous fluid and sodium does not reduce hospital stay following elective colorectal surgery.
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Patterns in current anaesthesiological peri-operative practice for colonic resections: a survey in five northern-European countries. Acta Anaesthesiol Scand 2006; 50:1152-60. [PMID: 16939479 DOI: 10.1111/j.1399-6576.2006.01121.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND For colorectal surgery, evidence suggests that optimal management includes: no pre-operative fasting, a thoracic epidural analgesia continued for 2 days post-operatively, and avoidance of fluid overload. In addition, no long-acting benzodiazepines on the day of surgery and use of short-acting anaesthetic medication may be beneficial. We examined whether these strategies have been adopted in five northern-European countries. METHODS In 2003, a questionnaire concerning peri-operative anaesthetic routines in elective, open colonic cancer resection was sent to the chief anaesthesiologist in 258 digestive surgical centres in Scotland, the Netherlands, Denmark, Sweden and Norway. RESULTS The response rate was 74% (n = 191). Although periods of pre-operative fasting up to 48 h were reported, most (> 85%) responders in all countries declared to adhere to guidelines for pre-operative fasting and oral clear liquids were permitted until 2-3 h before anaesthesia. Solid food was permitted up to 6-8 h prior to anaesthesia. In all countries more than 85% of the responders indicated that epidural anaesthesia was routinely used. Except for Denmark, long-acting benzodiazepines were still widely used. Short-acting anaesthetics were used in all countries except Scotland where isoflurane is the anaesthetic of choice. With the exception of Denmark, intravenous fluids were used unrestrictedly. CONCLUSION In northern Europe, most anaesthesiologists adhere to evidence-based optimal management strategies on pre-operative fasting, thoracic epidurals and short-acting anaesthetics. However, premedication with longer-acting agents is still common. Avoidance of fluid overload has not yet found its way into daily practice. This may leave patients undergoing elective colonic surgery at risk of oversedation and excessive fluid administration with potential adverse effects on surgical outcome.
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ESPEN Guidelines on Enteral Nutrition: Non-surgical oncology. Clin Nutr 2006; 25:245-59. [PMID: 16697500 DOI: 10.1016/j.clnu.2006.01.020] [Citation(s) in RCA: 386] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Accepted: 01/20/2006] [Indexed: 02/06/2023]
Abstract
Enteral nutrition (EN) by means of oral nutritional supplements (ONS) and tube feeding (TF) offers the possibility of increasing or ensuring nutrient intake in cases where normal food intake is inadequate. These guidelines are intended to give evidence-based recommendations for the use of ONS and TF in cancer patients. They were developed by an interdisciplinary expert group in accordance with officially accepted standards, are based on all relevant publications since 1985 and were discussed and accepted in a consensus conference. Undernutrition and cachexia occur frequently in cancer patients and are indicators of poor prognosis. EN should be started if undernutrition already exists or if food intake is markedly reduced for more than 7-10 days. Standard formulae are recommended for EN. Nutritional needs generally are comparable to non-cancer subjects. In cachectic patients metabolic modulators such as progestins, steroids and possibly eicosapentaenoic acid may help to improve nutritional status. EN is indicated preoperatively for 5-7 days in cancer patients undergoing major abdominal surgery. During radiotherapy of head/neck and gastrointestinal regions dietary counselling and ONS prevent weight loss and interruption of radiotherapy. Routine EN is not indicated during (high-dose) chemotherapy.
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Early results from instituting an enhanced recovery program after colorectal surgery at two different surgical institutions in the EU. Clin Nutr 2003. [DOI: 10.1016/s0261-5614(03)80281-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Dietary effect on blood pressure. Lancet 2002; 360:1785-6; author reply 1786. [PMID: 12480455 DOI: 10.1016/s0140-6736(02)11695-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Gene expression analysis by massively parallel signature sequencing (MPSS) on microbead arrays. Nat Biotechnol 2000; 18:630-4. [PMID: 10835600 DOI: 10.1038/76469] [Citation(s) in RCA: 1017] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We describe a novel sequencing approach that combines non-gel-based signature sequencing with in vitro cloning of millions of templates on separate 5 microm diameter microbeads. After constructing a microbead library of DNA templates by in vitro cloning, we assembled a planar array of a million template-containing microbeads in a flow cell at a density greater than 3x10(6) microbeads/cm2. Sequences of the free ends of the cloned templates on each microbead were then simultaneously analyzed using a fluorescence-based signature sequencing method that does not require DNA fragment separation. Signature sequences of 16-20 bases were obtained by repeated cycles of enzymatic cleavage with a type IIs restriction endonuclease, adaptor ligation, and sequence interrogation by encoded hybridization probes. The approach was validated by sequencing over 269,000 signatures from two cDNA libraries constructed from a fully sequenced strain of Saccharomyces cerevisiae, and by measuring gene expression levels in the human cell line THP-1. The approach provides an unprecedented depth of analysis permitting application of powerful statistical techniques for discovery of functional relationships among genes, whether known or unknown beforehand, or whether expressed at high or very low levels.
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Abstract
Cancer cachexia is a syndrome of progressive wasting which has been suggested to be mediated by tumour-necrosis factor-alpha, interleukins 1 and 6, interferon-gamma and leukaemia-inhibitory factor. It has proved difficult to correlate levels of tumour-necrosis factor-alpha and interleukin-6 with cancer cachexia, and the weight loss induced by leukaemia-inhibitory factor may be due to toxicity. In the murine adenocarcinoma MAC16, cachexia is mediated by circulatory catabolic factors, which we have now isolated using an antibody cloned from splenocytes of mice transplanted with the MAC16 tumour, with a delayed cachexia. The material is a proteoglycan of relative molecular mass 24K which produces cachexia in vivo by inducing catabolism of skeletal muscle. The 24K material was also present in urine of cachectic cancer patients, but was absent from normal subjects, patients with weight loss due to trauma, and cancer patients with little or no weight loss. This suggests that cachexia in mice and humans may be produced by the same material.
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Real time kinetics of restriction endonuclease cleavage monitored by fluorescence resonance energy transfer. Nucleic Acids Res 1994; 22:3155-9. [PMID: 8065930 PMCID: PMC310290 DOI: 10.1093/nar/22.15.3155] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The kinetics of PaeR7 endonuclease-catalysed cleavage reactions of fluorophor-labeled oligonucleotide substrates have been examined using fluorescence resonance energy transfer (FRET). A series of duplex substrates were synthesized with an internal CTCGAG PaeR7 recognition site and donor (fluorescein) and acceptor (rhodamine) dyes conjugated to the opposing 5' termini. The time-dependent increase in donor fluorescence resulting from restriction cleavage of these substrates was continuously monitored and the initial rate data was fitted to the Michaelis-Menten equation. The steady state kinetic parameters for these substrates were in agreement with the rate constants obtained from a gel electrophoresis-based fixed time point assay using radiolabeled substrates. The FRET method provides a rapid continuous assay as well as high sensitivity and reproducibility. These features should make the technique useful for the study of DNA-cleaving enzymes.
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Premature translation termination mutations are efficiently suppressed in a highly conserved region of yeast Ste6p, a member of the ATP-binding cassette (ABC) transporter family. J Biol Chem 1994; 269:17802-8. [PMID: 7517933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The requirements for efficient translation termination are incompletely understood. Since the local context surrounding stop codons can influence the efficiency of translation termination, premature termination codons introduced by random mutation may not always terminate at the optimal efficiencies expected of naturally occurring stop codons. To investigate whether this could result in physiologically significant levels of read through, we examined the suppression of premature translation termination mutations within a sequence motif of the yeast Ste6 protein (Ste6p) that is highly conserved among members of the ATP-binding cassette (ABC) transporter family. The human cystic fibrosis transmembrane conductance regulator (CFTR), which is defective in individuals with the disease cystic fibrosis, is also a member of this protein family. The mutations examined in Ste6p were chosen because a premature termination codon at the corresponding residue of CFTR has previously been reported to cause less severe pulmonary involvement than some missense mutations, suggesting that low level suppression of this stop codon could be occurring. Our results indicate that these premature stop codons in Ste6p can be suppressed at frequencies as high as 10%. Characterization of this phenomenon using a beta-galactosidase read through assay system showed that a limited sequence context surrounding this site contained information that was sufficient to cause suppression of translation termination. Amino acid sequence analysis of the full-length translation products produced by read through of an amber codon demonstrated that termination suppression was mediated by near-cognate tRNA mispairing that resulted in the insertion of tyrosine, lysine, or tryptophan.
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Abstract
African trypanosomes are protozoan parasites that cause a number of diseases of man and domesticated animals in large regions of sub-Saharan Africa. The diseases have proven to be particularly difficult to prevent or to effectively treat due to features of both the trypanosome and the insect vector, the tsetse fly. The habitat of the tsetse and its resistance to insecticides have rendered vector control efforts ineffective. Attempts to develop a vaccine against the African trypanosomes has been dwarfed by the parasite's ability to change the composition of its exposed surface antigens. This process of antigenic variation allows the parasite to avoid the host's immune response and presents the host with a seemingly endless antigenic repertoire. Since conventional approaches to the control of African trypanosomiasis have largely met with failure, there has been a renewed interest in identifying novel aspects of the biology, biochemistry, and molecular biology of trypanosomes that might be exploited to develop new targets for vaccines or chemotherapy. Importantly, this research has opened a virtual Pandora's box of exciting biochemical and molecular surprises, which makes the African trypanosomes not only important medical pathogens but also an exciting experimental system for the basic scientist. In this review, the authors will describe some of the most recent and intriguing developments in the field of molecular parasitology.
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Structure and function of MRP20 and MRP49, the nuclear genes for two proteins of the 54 S subunit of the yeast mitochondrial ribosome. J Biol Chem 1992; 267:5162-70. [PMID: 1544898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
MRP20 and MRP49 are proteins of the large subunit of the mitochondrial ribosome in Saccharomyces cerevisiae. Their genes were identified through immunological screening of a genomic library in the expression vector lambda gt11. Nucleotide sequencing revealed that MRP49 is tightly linked to TPK3 and encodes a 16-kDa, basic protein with no significant relatedness to any other known protein. MRP20 specifies a 263-amino-acid polypeptide with sequence similarity to members of the L23 family of ribosomal proteins. The levels of the mRNAs and proteins for both MRP20 and MRP49 were regulated in response to carbon source. In [rho0] strains lacking mitochondrial rRNA, the levels of the two proteins were reduced severalfold, presumably because the unassembled proteins are unstable. Null mutants of MRP20 converted to [rho-] or [rho0], a characteristic phenotype of mutations in essential genes for mitochondrial translation. Inactivation of MRP49 caused a cold-sensitive respiration-deficient phenotype, indicating that MRP49 is not an essential ribosomal protein. The mrp49 mutants were defective in the assembly of stable 54 S ribosomal subunits at the nonpermissive temperature. With the results presented here, there are now published sequences for 14 yeast mitochondrial ribosomal proteins, only five of which bear discernable relationships to eubacterial ribosomal proteins.
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Structure and function of MRP20 and MRP49, the nuclear genes for two proteins of the 54 S subunit of the yeast mitochondrial ribosome. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42745-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Abstract
The heat-shock protein, HSP60, is abundant in prokaryotes and eukaryotes and is required in the assembly of specific proteins. We have cloned the Saccharomyces cerevisiae HSP60 gene from a lambda gt11 genomic library using monoclonal antibodies, have obtained its sequence, determined its transcription start point, and shown that it exists as a single copy. The predicted HSP60 contains a mitochondrial target sequence and exhibits striking amino acid sequence similarity to its counterparts in bacteria, plants, and humans. These data indicate a high level of evolutionary conservation and are consistent with the suggestion of evolutionarily conserved function [Hemmingsen et al., Nature 333 (1988), 330-334].
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34
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Structure and regulation of a nuclear gene in Saccharomyces cerevisiae that specifies MRP7, a protein of the large subunit of the mitochondrial ribosome. Mol Cell Biol 1988; 8:3636-46. [PMID: 2851722 PMCID: PMC365419 DOI: 10.1128/mcb.8.9.3636-3646.1988] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The gene for MRP7, a 40-kilodalton protein of the large subunit of the yeast mitochondrial ribosome, was identified in a lambda gt11 expression library by immunological screening with a monoclonal antibody to MRP7. An intact copy of MRP7 was then isolated from a yeast genomic library by colony hybridization. Gene disruption showed that MRP7 protein was essential for ribosomal function. Sequencing of MRP7 revealed a coding region for a basic (pI 10.6), 43.2-kilodalton protein containing 371 amino acid residues. Amino acid residues 28 to 112 of the deduced MRP7 sequence aligned with the 84 residues of the Escherichia coli ribosomal protein L27, but no significant similarity was detected between the carboxy-terminal 259 amino acids of MRP7 and other protein sequences in existing computer data bases. Within the aligned region, there was 49% amino acid identity between MRP7 and L27, compared with the 57% identity observed between L27 and its homolog in Bacillus stearothermophilus. The steady-state levels of the MRP7 protein and its mRNA were monitored in response to catabolite repression and to increased dosage of the MRP7 gene. The response to catabolite repression was characterized by a ninefold change in the level of the protein and little, if any, change in the level of the mRNA. In cells carrying the MRP7 gene on a high-copy-number plasmid, the mRNA was increased 20-fold, but there was no significant increase in MRP7 protein. Furthermore, MRP7 mRNA and protein accumulated at normal levels in [rho0] cells, which are devoid of 21S rRNA, indicating that the protein is relatively stable in the absence of ribosome assembly. Together, these results suggest that MRP7 is regulated posttranscriptionally, probably at the level of protein synthesis rather than protein turnover.
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Abstract
Eighteen patients with advanced cancer have been treated intravenously with human recombinant tumour necrosis factor (rhTNF). The drug produced febrile reactions at all doses although these were preventable by steroids and indomethacin. Doses at or above 9 x 10(5) units (400 micrograms)m-2 were associated with hypotension, abnormal liver enzymes, leucopenia and mild renal impairment in a substantial proportion of patients. RhTNF was cleared from plasma with a half life of approximately 20 minutes but non-linear pharmacokinetics lymphoma, improvements in their tumours were recorded. RhTNF was noted to produce rapid increases in serum C-reactive protein concentrations. Endogenous TNF levels were not found to be elevated in 72 cancer patients. TNF deserves further therapeutic evaluation and these observations support its biological importance as an endogenous pyrogen, mediator of acute phase protein responses, and a mediator of endotoxic shock.
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36
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Abstract
The pentapeptide BOC-Phe-Phe-difluorostatone-Leu-Phe-NH2 has been prepared and found to be a potent inhibitor of human renin. This compound contains a difluoromethylene ketone group that exists predominantly in the hydrated form in water. The difluorostatone-containing peptide is 7-fold and 22-fold more potent than the analogous statine- and statone-containing peptides, respectively. Structure/activity analysis of the most potent inhibitor was carried out by replacing some of the peptide bonds with trans-alkenes. In all cases, a dramatic loss in binding to renin was observed. A number of statine-containing inhibitors of renin have been reported and this work suggests that the replacement of statine with difluorostatone will yield more potent compounds.
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