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Chambers P, Forster MD, Patel A, Duncan N, Kipps E, Wong ICK, Jani Y, Wei L. Development and validation of a risk score (Delay-7) to predict the occurrence of a treatment delay following cycle 1 chemotherapy. ESMO Open 2023; 8:100743. [PMID: 36542904 PMCID: PMC10024092 DOI: 10.1016/j.esmoop.2022.100743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/09/2022] [Accepted: 11/21/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The risk of toxicity-related dose delays, with cancer treatment, should be included as part of pretreatment education and be considered by clinicians upon prescribing chemotherapy. An objective measure of individual risk could influence clinical decisions, such as escalation of standard supportive care and stratification of some patients, to receive proactive toxicity monitoring. PATIENTS AND METHODS We developed a logistic regression prediction model (Delay-7) to assess the overall risk of a chemotherapy dose delay of 7 days for patients receiving first-line treatments for breast, colorectal and diffuse large B-cell lymphoma. Delay-7 included hospital treated, age at the start of chemotherapy, gender, ethnicity, body mass index, cancer diagnosis, chemotherapy regimen, colony stimulating factor use, first cycle dose modifications and baseline blood values. Baseline blood values included neutrophils, platelets, haemoglobin, creatinine and bilirubin. Shrinkage was used to adjust for overoptimism of predictor effects. For internal validation (of the full models in the development data) we computed the ability of the models to discriminate between those with and without poor outcomes (c-statistic), and the agreement between predicted and observed risk (calibration slope). Net benefit was used to understand the risk thresholds where the model would perform better than the 'treat all' or 'treat none' strategies. RESULTS A total of 4604 patients were included in our study of whom 628 (13.6%) incurred a 7-day delay to the second cycle of chemotherapy. Delay-7 showed good discrimination and calibration, with c-statistic of 0.68 (95% confidence interval 0.66-0.7), following internal validation and calibration-in-the-large of -0.006. CONCLUSIONS Delay-7 predicts a patient's individualised risk of a treatment-related delay at cycle two of treatment. The score can be used to stratify interventions to reduce the occurrence of treatment-related toxicity.
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Affiliation(s)
- P Chambers
- Department of Practice and Policy, School of Pharmacy, University College London, London, UK; The Centre for Medicines Optimisation Research and Education, University College London NHS Foundation Trust, London, UK.
| | - M D Forster
- University College London Cancer Institute, London, UK
| | - A Patel
- The Royal Marsden Hospital, London, UK
| | - N Duncan
- University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - E Kipps
- The Royal Marsden Hospital, London, UK
| | - I C K Wong
- Department of Practice and Policy, School of Pharmacy, University College London, London, UK; The Centre for Medicines Optimisation Research and Education, University College London NHS Foundation Trust, London, UK
| | - Y Jani
- Department of Practice and Policy, School of Pharmacy, University College London, London, UK; The Centre for Medicines Optimisation Research and Education, University College London NHS Foundation Trust, London, UK
| | - L Wei
- Department of Practice and Policy, School of Pharmacy, University College London, London, UK; The Centre for Medicines Optimisation Research and Education, University College London NHS Foundation Trust, London, UK
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Watson M, Chambers P, Shiu KK, Bridgewater J, Desai M, Roylance R, Tailor A, Masento S, Forster M, Al Moubayed N. 1859P Using deep learning with demographic and laboratory values from baseline to cycle 2 to predict subsequent renal and hepatic function. Ann Oncol 2021. [DOI: 10.1016/j.annonc.2021.08.746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Karna SR, Chambers P, Singh P, Lopez-Villalobos N, Kongara K. Evaluation of analgesic interaction between morphine, maropitant and dexmedetomidine in dogs undergoing ovariohysterectomy. N Z Vet J 2021; 70:10-21. [PMID: 33950785 DOI: 10.1080/00480169.2021.1927231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
ABSTRACTAims: To compare the analgesic effect of morphine combined with maropitant and/or dexmedetomidine to morphine alone but at a higher dose, and to evaluate the pharmacokinetics of the drug combinations, in dogs undergoing ovariohysterectomy (OHE).Methods: Forty client-owned dogs were randomised into four treatment groups (n = 10 per group) each to receive a different analgesic protocol. After premedication with I/M acepromazine, anaesthesia was induced with propofol to effect and maintained with isoflurane in 100% oxygen delivered via a circle system. The heart rate, respiratory rate, blood pressure, haemoglobin oxygen saturation, end-tidal partial pressure of carbon dioxide, electrocardiogram and rectal temperature were monitored during anaesthesia. The test drugs (Mor: 0.6 mg/kg morphine; Maro + Mor: 0.3 mg/kg morphine and 1 mg/kg maropitant; Dex + Mor: 0.3 mg/kg morphine and 10 μg/kg dexmedetomidine; Dex + Maro + Mor: 0.2 mg/kg morphine, 7 μg/kg dexmedetomidine and 0.7 mg/kg maropitant) were administered I/M after induction of anaesthesia and 30 minutes before the expected start time of ovariohysterectomy, which was carried out by veterinary students under veterinary supervision. The short form of the Glasgow composite measure pain scale (CMPS-SF) and visual analogue scale (VAS) were used for pain assessment at 15 and 30 minutes and 1, 2, 3, 6, 9 and 24 hours after extubation. Dogs with CMPS-SF pain score ≥ 6 received rescue analgesia with S/C buprenorphine (0.02 mg/kg). Blood samples were collected before, 15, 30, 60 and 120 minutes after injection of the test drugs and concentration of the test drugs in plasma was determined by liquid chromatography-mass spectrometry.Results: Dogs that received Dex + Mor had significantly lower CMPS-SF (estimate of difference = -1.53 (SE 0.58); p = 0.010) and VAS (estimate of difference = -0.67 (SE 0.25); p = 0.007) scores compared to the dogs that received morphine alone. There was no evidence of a difference in the number of dogs requiring rescue between groups. All dogs that received dexmedetomidine showed cardiac arrhythmia and second-degree heart block. Mean (SD) maximum concentrations (Cmax,) of morphine in plasma were 6.8 (4.56), 9.56 (8.29), 9.30 (3.35) and 18.99 (9.41) ng/mL for the groups Dex + Mor, Dex + Maro + Mor, Maro + Mor and Mor respectively. The Cmax of morphine was significantly lower in the Dex + Mor (p = 0.004), Dex + Maro + Mor (p = 0.034) and Maro + Mor (p = 0.018) groups compared to the Mor group.Conclusions For dogs undergoing ovariohysterectomy, lower doses of morphine (0.2 and 0.3 mg/kg) combined with dexmedetomidine or maropitant may provide analgesia equivalent to or better than morphine when given alone at a higher dose (0.6 mg/kg).Abbreviations: AUC: Area under curve; Cmax: Maximum concentration in plasma; CMPS-SF: Glasgow composite measure pain scale - short form; NK1: Neurokinin-1; OHE: Ovariohysterectomy; Tmax: Time to Cmax; T1/2: Half-life of terminal elimination phase; VAS: Visual analogue scale.
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Affiliation(s)
- S R Karna
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - P Chambers
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - P Singh
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - N Lopez-Villalobos
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - K Kongara
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
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Wareing J, Wareing S, Power A, Chambers P. “Pseudoaneurysm” of a nasogastric tube. Br J Oral Maxillofac Surg 2020; 58:1052-1053. [DOI: 10.1016/j.bjoms.2020.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 03/12/2020] [Indexed: 10/24/2022]
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Sano H, Chambers P, Bridges J. Effects of preemptive norepinephrine infusion prior to hypotension on anesthetic management in dogs undergoing ovariohysterectomy. Vet Anaesth Analg 2019. [DOI: 10.1016/j.vaa.2019.08.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Payne H, Jamieson L, Prentice M, O'Connor A, Wong ICK, Chambers P. Preferences for Toxicity Monitoring of Patients on Abiraterone Acetate Plus Prednisone. Clin Oncol (R Coll Radiol) 2018; 30:674-675. [PMID: 30149920 DOI: 10.1016/j.clon.2018.07.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 07/19/2018] [Indexed: 11/15/2022]
Affiliation(s)
- H Payne
- University College London Hospitals NHS Foundation Trust, London, UK
| | - L Jamieson
- UCL School of Pharmacy, London, UK; UCLH-UCL Centre for Medicines Optimisation Research and Education, London, UK
| | - M Prentice
- University College London Hospitals NHS Foundation Trust, London, UK
| | - A O'Connor
- University College London Hospitals NHS Foundation Trust, London, UK
| | - I C K Wong
- UCL School of Pharmacy, London, UK; UCLH-UCL Centre for Medicines Optimisation Research and Education, London, UK; Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong
| | - P Chambers
- University College London Hospitals NHS Foundation Trust, London, UK; UCLH-UCL Centre for Medicines Optimisation Research and Education, London, UK
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Pike TW, Mushtaq F, Mann RP, Chambers P, Hall G, Tomlinson JE, Mir R, Wilkie RM, Mon‐Williams M, Lodge JPA. Operating list composition and surgical performance. Br J Surg 2018; 105:1061-1069. [PMID: 29558567 PMCID: PMC6032881 DOI: 10.1002/bjs.10804] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Revised: 10/30/2017] [Accepted: 11/27/2017] [Indexed: 12/25/2022]
Abstract
BACKGROUND Recent reviews suggest that the way in which surgeons prepare for a procedure (warm up) can affect performance. Operating lists present a natural experiment to explore this phenomenon. The aim was to use a routinely collected large data set on surgical procedures to understand the relationship between case list order and operative performance. METHOD Theatre lists involving the 35 procedures performed most frequently by senior surgeons across 38 private hospitals in the UK over 26 months were examined. A linear mixed-effects model and matched analysis were used to estimate the impact of list order and the cost of switching between procedures on a list while controlling for key prognosticators. The influence of procedure method (open versus minimally invasive) and complexity was also explored. RESULTS The linear mixed-effects model included 255 757 procedures, and the matched analysis 48 632 pairs of procedures. Repeating the same procedure in a list resulted in an overall time saving of 0·98 per cent for each increase in list position. Switching between procedures increased the duration by an average of 6·48 per cent. The overall reduction in operating time from completing the second procedure straight after the first was 6·18 per cent. This pattern of results was consistent across procedure method and complexity. CONCLUSION There is a robust relationship between operating list composition and surgical performance (indexed by duration of operation). An evidence-based approach to structuring a theatre list could reduce the total operating time.
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Affiliation(s)
- T. W. Pike
- Faculty of Medicine and HealthUniversity of LeedsLeedsUK
- Leeds Teaching Hospitals NHS TrustLeedsUK
| | - F. Mushtaq
- Faculty of Medicine and HealthUniversity of LeedsLeedsUK
| | - R. P. Mann
- School of MathematicsUniversity of LeedsLeedsUK
| | - P. Chambers
- Leeds Institute for Data Analytics, University of LeedsLeedsUK
| | - G. Hall
- Leeds Institute for Data Analytics, University of LeedsLeedsUK
- Leeds Teaching Hospitals NHS TrustLeedsUK
| | - J. E. Tomlinson
- Department of OrthopaedicsSheffield Teaching HospitalsSheffieldUK
- Department of Medical EducationSheffield UniversitySheffieldUK
| | - R. Mir
- Faculty of Medicine and HealthUniversity of LeedsLeedsUK
- Leeds Teaching Hospitals NHS TrustLeedsUK
| | - R. M. Wilkie
- Faculty of Medicine and HealthUniversity of LeedsLeedsUK
| | | | - J. P. A. Lodge
- Faculty of Medicine and HealthUniversity of LeedsLeedsUK
- Leeds Teaching Hospitals NHS TrustLeedsUK
- Spire Healthcare, Spire Leeds HospitalLeedsUK
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Wotherspoon R, Chambers P. Uncommonly reported effects of methamphetamine. Br J Oral Maxillofac Surg 2017; 55:344-345. [DOI: 10.1016/j.bjoms.2016.08.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 08/23/2016] [Indexed: 10/20/2022]
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Oakley C, Chambers P, Board R, Gallagher C, Young E, Purcell S, Mansi J. Good practice guideline: Promoting Early Identification of Systemic Anti-Cancer Therapies Side Effects: – Two Approaches. ACTA ACUST UNITED AC 2016. [DOI: 10.7748/cnp.15.9.19.s20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Smith T, Mehta S, Chambers P. A Study into the Benefits of Medication Usage Reviews (MURs) in Patients being Treated for Prostate Cancer. Clin Oncol (R Coll Radiol) 2016. [DOI: 10.1016/j.clon.2015.12.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ponchel F, Chambers P, Droop A, Parmar R, Halstead-Rastrick J, Emery P. A1.22 NaÏve and memory CD4 +T-cell DNA methylation profile in RA. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-207259.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Janssen PWM, Lentle RG, Chambers P, Reynolds GW, De Loubens C, Hulls CM. Spatiotemporal organization of standing postprandial contractions in the distal ileum of the anesthetized pig. Neurogastroenterol Motil 2014; 26:1651-62. [PMID: 25251369 DOI: 10.1111/nmo.12447] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 08/30/2014] [Indexed: 02/08/2023]
Abstract
BACKGROUND Spatiotemporal (ST) mapping has mainly been applied to ex vivo preparations of the gut. We report the results of ST mapping of the spontaneous and remifentanil-induced motility of circular and longitudinal muscles of the distal ileum in the postprandial anaesthetized pig. METHODS Spatiotemporal maps of strain rate were derived from image sequences of an exteriorized loop of ileum on a superfusion tray at laparotomy. Parameters were obtained by direct measurement from these maps, and by auto- and cross-correlation of map segments. KEY RESULTS Localized domains of standing longitudinal and circular activity that alternated between neighboring domains occurred spontaneously and both were promptly extinguished following intraluminal dosage with lidocaine. Longitudinal or circular contractions within a domain typically occurred at times that would coincide with every second or third cycle of the slow wave but propagated within the domain at a rate consistent with that reported within spike patches. Shortly after intravenous administration of remifentanil, longitudinal and circular contractions at the reported slow wave frequency propagated over longer distances at a high speed before slowing to a rate similar to that reported for slow waves. CONCLUSIONS & INFERENCES ST mapping based on cross-correlation is a robust tool for the analysis of intestinal movement and minimizing movement artefacts. We propose that the ST pattern of standing longitudinal and circular contractions arises from variation in the refractory period of smooth muscle, and hence, in its response to successive slow waves with neural stimuli influencing the former and having a mainly permissive role.
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Affiliation(s)
- P W M Janssen
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
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Lentle RG, Janssen PWM, Deloubens C, Lim YF, Hulls C, Chambers P. Mucosal microfolds augment mixing at the wall of the distal ileum of the brushtail possum. Neurogastroenterol Motil 2013; 25:881-e700. [PMID: 23941237 DOI: 10.1111/nmo.12203] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 07/19/2013] [Indexed: 02/08/2023]
Abstract
BACKGROUND Recent work suggests that mixing in the small intestine takes place in central luminal and peripheral compartments. However, while movements of villi have been described, the mechanisms by which peripheral mixing are engendered remain unclear. METHODS We examined the disposition and movement of mucosa and associated villi during contractions of the everted terminal ileum of the brushtail possum. We then simulated the effect of these movements on peripheral mixing. KEY RESULTS Compression of the intestinal mucosa by phasic longitudinal or radial contractions created short-lived microfolds, which were of similar scale to the attached villi. The packing density of the villous tips increased in the concavities and decreased on the crests of these microfolds. Simulations showed that these caused liquid digesta to be expelled from, or drawn into, intervillous spaces, significantly augmenting peripheral, but not bulk, luminal mixing. CONCLUSIONS & INFERENCES We describe a mechanism by which peripheral mixing may be engendered by mucosal microfolds without requiring the coordinated contraction of individual villi or groups of villi.
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Affiliation(s)
- R G Lentle
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
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Lim YF, Williams MAK, Lentle RG, Janssen PWM, Mansel BW, Keen SAJ, Chambers P. An exploration of the microrheological environment around the distal ileal villi and proximal colonic mucosa of the possum (Trichosurus vulpecula). J R Soc Interface 2013; 10:20121008. [PMID: 23389898 PMCID: PMC3627112 DOI: 10.1098/rsif.2012.1008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 01/17/2013] [Indexed: 12/15/2022] Open
Abstract
Multiple particle-tracking techniques were used to quantify the thermally driven motion of ensembles of naked polystyrene (0.5 µm diameter) microbeads in order to determine the microrheological characteristics around the gut mucosa. The microbeads were introduced into living ex vivo preparations of the wall of the terminal ileum and proximal colon of the brushtail possum (Trichosurus vulpecula). The fluid environment surrounding both the ileal villi and colonic mucosa was heterogeneous; probably comprising discrete viscoelastic regions suspended in a continuous Newtonian fluid of viscosity close to water. Neither the viscosity of the continuous phase, the elastic modulus (G') nor the sizes of viscoelastic regions varied significantly between areas within 20 µm and areas more than 20 µm from the villous mucosa nor from the tip to the sides of the villous mucosa. The viscosity of the continuous phase at distances further than 20 µm from the colonic mucosa was greater than that at the same distance from the ileal villous mucosa. Furthermore, the estimated sizes of viscoelastic regions were significantly greater in the colon than in the ileum. These findings validate the sensitivity of the method and call into question previous hypotheses that a contiguous layer of mucus envelops all intestinal mucosa and restricts diffusive mass transfer. Our findings suggest that, in the terminal ileum and colon at least, mixing and mass transfer are governed by more complex dynamics than were previously assumed, perhaps with gel filtration by viscoelastic regions that are suspended in a Newtonian fluid.
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Affiliation(s)
- Y. F. Lim
- Institute of Food, Nutrition and Human Health, Massey University, Private Bag 11222, Palmerston North, New Zealand
| | - M. A. K. Williams
- Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand
- Riddet Institute, Massey University, Private Bag 11222, Palmerston North, New Zealand
- MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington, New Zealand
| | - R. G. Lentle
- Institute of Food, Nutrition and Human Health, Massey University, Private Bag 11222, Palmerston North, New Zealand
- Riddet Institute, Massey University, Private Bag 11222, Palmerston North, New Zealand
| | - P. W. M. Janssen
- Institute of Food, Nutrition and Human Health, Massey University, Private Bag 11222, Palmerston North, New Zealand
| | - B. W. Mansel
- Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand
- MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington, New Zealand
| | - S. A. J. Keen
- Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand
- MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington, New Zealand
| | - P. Chambers
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand
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Abdulkareem FB, Sanni LA, Richman SD, Chambers P, Hemmings G, Grabsch H, Quirke P, Elesha SO, Banjo AF, Atoyebi OA, Adesanya AA, Onyekwere CA, Ojukwu J, Anomneze EE, Rotimi O. KRAS and BRAF mutations in Nigerian colorectal cancers. West Afr J Med 2012; 31:198-203. [PMID: 23310942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
PURPOSE Activation of the KRAS oncogene is implicated in colorectal carcinogenesis and mutations have been reported in 30-50% of cases. BRAF mutation, though less common, is also reported and importantly associated with shorter progression-free interval. This study aims to determine the KRAS and BRAF mutation statuses of Nigerian colorectal cancers (CRC). METHODS Mutation analysis was carried out on archival paraffin-embedded blocks of CRC tissues. KRAS codons 12, 13 and 61 and BRAF V600E were assessed by pyrosequencing after DNA extraction from 200 cases at the Leeds Institute of Molecular Medicine, St. James's University Hospital, UK. Mutation rates and the spectra were determined. RESULTS Pyrosequencing was successful in 112 of 200 cases. KRAS mutation in codons 12 and 13 was demonstrated in 23 of 112 cases (21%); none in codon 61. BRAF mutation in codon 600 was demonstrated in 4.5%. CONCLUSION This study shows that 21% of Nigerian CRC patients carry a KRAS mutation; half the rate in Caucasians; and that BRAF mutation also occurs in Nigerian CRC cancers.
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Affiliation(s)
- F B Abdulkareem
- Department of Morbid Anatomy, College of Medicine University of Lagos
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Abstract
BACKGROUND In cancer patients with a large Body Surface Area, chemotherapy drug doses are often reduced, as studies have suggested that their pharmacokinetics may be altered. However, this strategy may result in underdosing obese patients. PATIENTS AND METHODS In three Medical Research Council trials of chemotherapy for advanced colorectal cancer, dose reductions were not mandated. This provided the opportunity to compare the toxicity levels in those obese patients fully dosed and to investigate if those under dosed experienced a worse survival. Body Mass Index (BMI) was used to classify patients as normal weight (BMI < 25), overweight (BMI 25-29), or obese (BMI 30+). RESULTS Of the 4781 patients, 2158 (45%) were classified as normal weight, 1753 (37%) as overweight, and 870 (18%) as obese. There was no evidence that, in those patients fully dosed, obese patients experienced more toxicity or that dose-reducing obese patients resulted in less toxicity. However, there was a suggestion that those obese patients who were given reduced doses had a worse progression-free survival [hazard ratio (HR) 1.21, 95% confidence interval (CI) 1.06-1.39, P = 0.006] and a slightly worse overall survival (HR 1.12, 95% CI 0.96-1.30, P = 0.152). CONCLUSION These results, although not a randomised comparison, do not support the policy of reducing chemotherapy doses for obese patients with colorectal cancer.
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Affiliation(s)
- P Chambers
- Pharmacy, University College London Hospital, London
| | - S H Daniels
- Pharmacy, University College London Hospital, London
| | - L C Thompson
- Medical Research Council Clinical Trials Unit, London, UK.
| | - R J Stephens
- Medical Research Council Clinical Trials Unit, London, UK
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Hill K, Gieseg M, Kingsbury D, Lopez-Villalobos N, Bridges J, Chambers P. The Efficacy and Safety of a Novel Lipophilic Formulation of Methimazole for the Once Daily Transdermal Treatment of Cats with Hyperthyroidism. J Vet Intern Med 2011; 25:1357-65. [DOI: 10.1111/j.1939-1676.2011.00799.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 07/31/2011] [Accepted: 08/12/2011] [Indexed: 11/29/2022] Open
Affiliation(s)
- K.E. Hill
- Institute of Veterinary and Animal Biomedical Sciences; Massey University; Palmerston North; New Zealand
| | - M.A. Gieseg
- Institute of Veterinary and Animal Biomedical Sciences; Massey University; Palmerston North; New Zealand
| | - D. Kingsbury
- Institute of Veterinary and Animal Biomedical Sciences; Massey University; Palmerston North; New Zealand
| | - N. Lopez-Villalobos
- Institute of Veterinary and Animal Biomedical Sciences; Massey University; Palmerston North; New Zealand
| | - J. Bridges
- Institute of Veterinary and Animal Biomedical Sciences; Massey University; Palmerston North; New Zealand
| | - P. Chambers
- Institute of Veterinary and Animal Biomedical Sciences; Massey University; Palmerston North; New Zealand
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Abstract
Butorphanol tartrate (2 mg/kg) was injected intravenously in 18 healthy broiler chickens to study its pharmacokinetics. Plasma samples were analysed by a highly sensitive high-performance liquid chromatography with diode-array detection method and pharmacokinetic parameters were calculated from the mean pooled data. With non-compartmental analysis, the terminal half-life (T(1/2.z)) was 71.3 minutes, clearance was 67.6 ml/minute/kg and the apparent volume of distribution was 6.9 l/kg. The concentration-time curve was also fitted to a two-compartmental model. In this analysis, elimination half-life (T(1/2β)) was 69.3 minutes, clearance was 74.6 ml/minute/kg and volume of distribution at steady state was 5.6 l/kg. The micro rate constants k(21), k(12) and k(10) were 0.034, 0.050 and 0.029, respectively. Butorphanol was well distributed in the chickens with rapid clearance. It remained above the minimum effective concentration for analgesia in mammals for approximately two hours in the chickens.
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Affiliation(s)
- P M Singh
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11-222, Palmerston North, 4442, New Zealand.
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Seymour MT, Brown SR, Richman S, Middleton GW, Maughan T, Olivier C, Gwyther SJ, Wadsley J, Chau I, Hickish T, Dawson LK, Falk S, O'Callaghan A, Benstead K, Wadd N, Oliver A, Chambers P, Marshall H, Napp V, Quirke P. Addition of panitumumab to irinotecan: Results of PICCOLO, a randomized controlled trial in advanced colorectal cancer (aCRC). J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.3523] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Janssen PWM, Lentle RG, Asvarujanon P, Chambers P, Stafford KJ, Hemar Y. Characterization of flow and mixing regimes within the ileum of the brushtail possum using residence time distribution analysis with simultaneous spatio-temporal mapping. J Physiol 2007; 582:1239-48. [PMID: 17495038 PMCID: PMC2075256 DOI: 10.1113/jphysiol.2007.134403] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 04/11/2007] [Accepted: 05/10/2007] [Indexed: 11/08/2022] Open
Abstract
We studied the flow and mixing regimes in isolated segments of the terminal ileum of brushtail possums during spontaneous circumferential and longitudinal contractions under conditions that allowed backflow and compared them with those of inactive segments. Residence time distributions (RTDs) were determined by perfusion with two probes of different rheological properties to which an inert dye marker was added. Ileal segment volume and oscillatory flow during the period of RTD determination were derived from spatiotemporal maps. High viscosity guar gum solution generated RTDs characteristic of laminar flow in inactive ileal segments which confirmed that no slip was occurring at the mucosal layer. In active segments, motility and consequent oscillatory flow imparted significant additional axial dispersion to the flow patterns of both probes. Mixing occurred episodically during periods when intestinal volume was reduced and onflow was augmented by peristalsis, which may prevent the establishment of steady state conditions. Marker concentration rose more steeply when active ileal segments were being perfused with a probe of similar viscosity to normal digesta than with low viscosity Earle's/Hepes solution, each being subject to similar levels of oscillatory flow. This indicated that a coarser mixing regime prevailed and that absorption of nutrients from viscous digesta would rely to a greater degree on molecular diffusion.
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Affiliation(s)
- P W M Janssen
- Institute of Food, Nutrition and Human Health, Massey University, Private Bag 11222, Palmerston North, New Zealand.
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Affiliation(s)
- D Generali
- Molecular Oncology Laboratories, Weatherall Institute of Molecular Medicine
| | - R Leek
- Nuffield Department of Clinical Laboratory Sciences, University of Oxford, John Radcliffe Hospital, Headington, Oxford, UK
| | - S B Fox
- Peter MacCallum Cancer Centre, St Andrews Place, East Melbourne, Victoria, Australia
| | - J W Moore
- Molecular Oncology Laboratories, Weatherall Institute of Molecular Medicine
| | - C Taylor
- Mutation Detection Facility-CRUK, St James's University Hospital, Leeds, UK
| | - P Chambers
- Mutation Detection Facility-CRUK, St James's University Hospital, Leeds, UK
| | - A L Harris
- Molecular Oncology Laboratories, Weatherall Institute of Molecular Medicine.
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Chapman EJ, Hurst CD, Pitt E, Chambers P, Aveyard JS, Knowles MA. Expression of hTERT immortalises normal human urothelial cells without inactivation of the p16/Rb pathway. Oncogene 2006; 25:5037-45. [PMID: 16619045 DOI: 10.1038/sj.onc.1209513] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The CDKN2A locus is frequently inactivated in urothelial cell carcinoma (UCC), yet how this alteration contributes to bladder tumorigenesis is not known. Although most UCC express telomerase, inactivation of the p16/Rb pathway is generally required for in vitro immortalisation. This and the involvement of p16 in senescence of normal human urothelial cells (NHUC) suggest that CDKN2A deletion may aid bypass of senescence and allow immortalisation. CDKN2A encodes p16 and p14ARF and therefore inactivation of this locus can disrupt both the Rb and p53 tumour suppressor pathways. Retrovirus-mediated transduction was used to specifically modulate the p16/Rb and/or p53 tumour suppressor pathways in NHUC and to express human telomerase reverse transcriptase (hTERT). Expression of hTERT bypassed Rb and p53 pathway-dependent barriers to proliferation and immortalised NHUC. TERT-NHUC had normal karyotypes, were non-tumorigenic and unexpectedly retained CDKN2A. Thus, the phenotypic significance of inactivation of CDKN2A in UCC may not be solely related to bypass of senescence. Phenotypic assays in human urothelial cells have relied on cell strains derived from invasive tumours or NHUC immortalised by expression of SV40-large T. The production of genetically normal but immortal NHUC lines now provides a valuable platform for experiments to examine the timing and combination of events necessary for UCC tumorigenesis.
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Affiliation(s)
- E J Chapman
- Cancer Research UK Clinical Centre, St James's University Hospital, Leeds, UK
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Abstract
BACKGROUND AND AIMS The aetiology of systemic scleroderma remains poorly understood. Twin studies suggest a low genetic input. Of the incriminated environmental agents, silica and vinyl chloride monomer exposure appear the most convincing. Spatiotemporal clustering has been demonstrated only three times previously. We now report a fourth cluster around Edenhope, western Victoria in terms of numerator and denominator estimates, cumulative incidence, distribution in time and space, and possible aetiological factors. METHODS Prevalence/cumulative incidence numerator and denominator values were obtained and validated. Each case was age-and gender-matched with two controls. A standardized postal questionnaire was used to obtain data on current, past history, family history, and occupational and non-occupational environmental exposure. RESULTS Six systemic scleroderma cases and one mixed connective tissue disease patient with a predominance of scleroderma features were identified. The 5-year cumulative incidence was 6.1/10,000, tenfold higher than the Sydney estimates for a similar, though non-identical time period. The gender ratio was 1:1. No cases were genetically related. A family history of scleroderma was validated in one instance and a family history of Raynaud's was noted in first degree relatives of two cases and one control. In all instances, Edenhope residence preceded disease onset. No one environmental agent was implicated in all cases. CONCLUSION A spatiotemporal cluster of systemic scleroderma was confirmed and validated. It occurred with a tenfold increased cumulative incidence to that expected and also extended beyond the initially defined 50 km radius of Edenhope. The cases identified were not related. Although no one specific environmental agent was identified, the spatiotemporal clustering would be compatible with an agent occurring at relatively high frequency, but with low disease conversion rates, such as silica inhalation (assuming sufficiently small particle size) or reaction to an infective agent.
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Affiliation(s)
- H Englert
- Rheumatology Department, Westmead Hospital, Westmead, NSW 2145, Australia
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Englert H, Joyner E, Thompson M, Garcia H, Chambers P, Horner D, Hunt C, Makaroff J, O'Connor H, Russell N, March L. Augmentation mammoplasty and 'silicone-osis'. Intern Med J 2004; 34:668-76. [PMID: 15610211 DOI: 10.1111/j.1445-5994.2004.00670.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Claims have been made that breast augmentation induces a previously unrecognized disease ("silicone-osis"). AIMS To confirm the existence of "silicone-osis", qualify and quantify its characteristics. METHODS In this population-based retrospective cohort study, the health status of 458 female Sydney residents who had augmentation mammoplasty for cosmetic reasons ("augmentation mammoplasty-exposed" or "exposed" cohort) between 1979 and 1983 was compared with the health status of 687 female Sydney residents who had non-silicone-associated plastic surgery ("augmentation mammoplasty-nonexposed" or "non-exposed" cohort). Both groups were matched for age (+/- 5 years), year of plastic surgery (+/- 2 years), plastic surgeon, anaesthetist and mode of anaesthesia. Outcome measures comprised dummy symptoms to assess reporting bias, as well as symptoms and symptom clusters from a comprehensive 78-symptom list. RESULTS Dummy variables were not over-reported by the exposed cohort. The following individual symptoms developed more commonly in the exposed cohort after index plastic surgery: "memory loss/confusion", "altered bowel habit", "chest pain made worse by deep breathing", "shortness of breath after walking up 10 steps", "breast pain", "sweating mainly at night" and "tunnel vision". Of eight identified symptom clusters, three were rejected as biologically unimportant: "joint swelling of the bunion joint", "haemorrhoids" and "breast lumps" (the latter two occurring more commonly in the non-exposed cohort). In contrast, five symptom clusters were thought to have potential biological importance and occurred more commonly in the exposed cohort. The symptom "night sweats" was common to all five clusters, and comprised the sole symptom in one instance. The other four multisymptom clusters were also characterized by "low energy" (lethargy) and "pins and needles", whereas "breast pain", "impaired memory", "muscle pain" and "reflux", occurred in three of the four clusters. CONCLUSION Cluster analysis suggested the existence of a multisystem disorder occurring more commonly in the exposed cohort and characterized by night sweats, lethargy, breast pain, impaired mentation, reflux, paraesthesiae, hand muscle weakness and myalgia. The argument against this being a new disease entity --"silicone-osis"-- however, was its presence, albeit at lower frequency, in the silicone-unexposed cohort. Thus this study did not confirm the existence of a new disease entity "silicone-osis" uniquely and causally associated with silicone exposure. The possible interpretations of these findings are discussed.
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Affiliation(s)
- H Englert
- Rheumatology Department, Westmead Hospital, Sydney, New South Wales, Australia
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McKeever U, Barman S, Hao T, Chambers P, Song S, Lunsford L, Hsu YY, Roy K, Hedley ML. Protective immune responses elicited in mice by immunization with formulations of poly(lactide-co-glycolide) microparticles. Vaccine 2002; 20:1524-31. [PMID: 11858858 DOI: 10.1016/s0264-410x(01)00509-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Parenteral administration of microparticle encapsulated DNA elicits immune responses to the encoded antigens. Experiments were performed to test whether the addition of certain lipophilic agents to such formulations enhanced the activity of a beta-galactosidase (beta-gal) DNA vaccine. Addition of either taurocholic acid (TA) or monomethoxy polyethylene-glycol-distearoylphosphatidylehanolamine (PEG-DSPE) increased the efficiency of DNA encapsulation. Immunization of mice with encapsulated DNA formulations containing either compound significantly increased the number of antibody positive responders over that achieved with non-lipid containing particles. Moreover, responding animals demonstrated trends towards higher antibody titers and increased T cell responses. Tumor protection against the CT26.CL25 tumor cell line was demonstrated with lipid and non-lipid containing formulations. These results are the first demonstration of protection obtained by parenteral administration of PLG encapsulated DNA vaccines.
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Affiliation(s)
- U McKeever
- Zycos Inc., 44 Hartwell Avenue, Lexington, MA 02421, USA
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Englert H, Joyner E, Mcgill N, Chambers P, Horner D, Hunt C, Makaroff J, O'Connor H, Russell N, March L. Women’s health after plastic surgery. Intern Med J 2001. [DOI: 10.1046/j.1445-5994.2001.00006.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Englert H, Joyner E, McGill N, Chambers P, Horner D, Hunt C, Makaroff J, O'Connor H, Russell N, March L. Women's health after plastic surgery. Intern Med J 2001; 31:77-89. [PMID: 11480483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
BACKGROUND Allegations that exposure to endogenous silicone, especially related to breast implants, might be causally related to connective tissue disease originated from case studies. More recent comparative studies have implied no such increased risk. The aims of the present study were to compare the prevalence and/or incidence of autoimmune and connective tissue disorders in a population-based cohort of female Sydney residents stratified by augmentation mammoplasty status. METHODS In this population-based retrospective cohort study, the health status of female Sydney residents who had augmentation mammoplasty for cosmetic reasons between 1979 and 1983 was compared with that of female Sydney residents who had non-silicone-associated plastic surgery over the same period. Both groups were matched for age (+/- 5 years), year of plastic surgery (+/- 2 years), plastic surgeon, anaesthetist and mode of anaesthesia. Outcome measures comprised rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, sicca symptoms polymyositis/ dermatomyositis, connective tissue disease overlap, digital vasospasm, abnormal nailfold capillaroscopy, elevated antinuclear antibody titre, carpal tunnel syndrome, tendonitis, osteoarthritis, psoriatic arthritis, livedo reticularis, thyroid disease, multiple sclerosis, axillary lymphadenopathy, fibromyalgia and breast carcinoma. RESULTS There was no difference in the occurrence of connective tissue diseases or connective tissue disease-related parameters, thyroid disorders, fibromyalgia or multiple sclerosis between cohorts. However, axillary adenopathy and low titre positive antinuclear antibody (ANA) occurred with a significantly greater frequency in the exposed cohort (odds ratio (OR) = 3.50, 95% confidence interval (CI) = 2.10-5.84 and OR = 1.29, 95% CI = 1.03-1.62, respectively). Axillary adenopathy correlated with capsular contracture (relative risk (RR) = 2.07, 95% CI = 1.22-3.51) and also the self-reported development of digital vasospasm (RR = 3.20, 95% CI = 1.46-7.03) after breast augmentation. CONCLUSIONS No association was found between augmentation mammoplasty exposure and various connective tissue diseases and/or their related features. However, axillary adenopathy and low titre ANA were detected more frequently in the exposed cohort. Women with axillary adenopathy were more likely to have breast capsular contracture and report digital vasospasm post-dating surgery. Given comparable frequencies of higher titre ANA of both cohorts, the finding of elevations of low titre ANA is of dubious clinical significance.
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Affiliation(s)
- H Englert
- Westmead Hospital, Sydney, New South Wales, Australia
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Englert H, Joyner E, Mcgill N, Chambers P, Horner D, Hunt C, Makaroff J, O'Connor H, Russell N, March L. Women's health after plastic surgery. Intern Med J 2001. [DOI: 10.1111/j.1444-0903.2001.00006.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Abstract
DNA can be formulated with synthetic polymers such as poly(lactide-co-glycolide) (PLG) to generate microparticles. Researchers have used either UV spectroscopy or fluorometry with PicoGreen((R)) dye to quantify PLG-encapsulated DNA. While the sensitivity of DNA detection and quantification by PicoGreen is higher ( approximately 12 pg/ml) compared to UV ( approximately 0.5 microg/ml), each method as an analytical tool has limitations. The premise of this work addresses the usefulness and limitations of each method to determine encapsulation efficiencies in PLG microspheres post-process, and to quantify release of DNA from microspheres during in vitro release experiments. In addition, assay conditions for accurate and reproducible extraction of DNA from PLG microspheres using a biphasic (aqueous/organic) solvent system are described. It was also determined that residual poly(vinyl alcohol) and DNA isoforms (linear, nicked, supercoiled) affected PicoGreen/DNA fluorescence values.
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Affiliation(s)
- S P Barman
- ZYCOS Inc., 44 Hartwell, Lexington, MA 02421, USA
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Hardy LA, Harvey IJ, Chambers P, Gillespie JI. A putative alternatively spliced variant of the P2X(1) purinoreceptor in human bladder. Exp Physiol 2000; 85:461-3. [PMID: 10918085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Activation of purinergic P2X receptors, putatively P2X1, may be important in the initiation of contraction in human detrusor. Purinergic transmission may be more important in muscle taken from patients with bladder instability. In this study the presence of the P2X1 receptor subtype was confirmed using RT-PCR. In addition, the results indicate, at the mRNA level, the presence of a splice variant of P2X1 that is lacking part of the second transmembrane domain. It is therefore possible that human bladder expresses multiple isoforms of the P2X1 receptor which may be potential sites for modifying or regulating putative purinergic activation of the human bladder.
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Affiliation(s)
- L A Hardy
- Department of Surgery, School of Surgical and Reproductive Sciences, The Medical School, University of Newcastle, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
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Taylor DL, Ahmed PS, Tyms AS, Wood LJ, Kelly LA, Chambers P, Clarke J, Bedard J, Bowlin TL, Rando RF. Drug resistance and drug combination features of the human immunodeficiency virus inhibitor, BCH-10652 [(+/-)-2'-deoxy-3'-oxa-4'-thiocytidine, dOTC]. Antivir Chem Chemother 2000; 11:291-301. [PMID: 10950391 DOI: 10.1177/095632020001100405] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The heterosubstituted nucleoside analogue dOTC [( )-2'-deoxy-3'-oxa-4'-thiocytidine, BCH-10652] is a racemic compound structurally related to 3TC (lamivudine), but has the oxygen and sulphur in the furanosyl ring transposed. Both the enantiomers (-)dOTC (BCH-10618) and (+)dOTC (BCH-10619) had equivalent activity against wild-type strains of HIV-1 in C8166 T-cells (EC50 1.0-10.0 microM) and in PBMCs (EC50 0.1-3.0 microM). Investigation of the activity of dOTC and its enantiomers against laboratory strains of HIV-1 with defined resistance to 3TC, AZT (zidovudine), ddl (didanosine), PMEA (adefovir), nevirapine and saquinavir indicated that sensitivity was maintained (<3-fold change in EC50) in all cases, with the exception of HIV-1RF 3TC-resistant viruses. The degree of resistance recorded for dOTC (four- to sevenfold), (-)dOTC (five- to eightfold) and (+)dOTC (five- to >18-fold) against these M1841 or M184V mutants, was significantly less than that recorded for 3TC (>100-fold). In addition, the inhibitory effect of the compounds against clinical isolates of HIV-1 recovered from patients with suspected resistance to 3TC and AZT was investigated. Clinical isolates were genotyped using the Murex Line Probe Assay (LiPA) and subgrouped into wild-type, 3TC-resistant and dual 3TC/AZT-resistant, as well as undefined or mixed genotype populations. Compared with the mean EC50 values obtained with genotypically and phenotypically wild-type clinical isolates, the mean EC50 values calculated for isolates phenotypically resistant to 3TC or 3TC and AZT were only 2.6-, 1.6- and 8.2-fold higher for dOTC, (-)dOTC and (+)dOTC, respectively. When the rate of emergence of virus resistant to dOTC and its enantiomers in vitro was investigated, virus resistant to (+)dOTC was readily selected for (<10 passages), and a methionine (ATG) to isoleucine (ATA) amino acid change at codon 184 was identified. In contrast, virus resistant to dOTC and (-)dOTC took longer to appear (15-20 passages), with a methionine (ATG) to valine (GTG) amino acid change at position 184 identified in both cases. In addition, virus passaged 20 times in the presence of dOTC also had a partial lysine (AAA) to arginine (AGA) exchange at position 65. These viruses showed only low-level resistance to dOTC and its enantiomers, but were highly resistant to 3TC. The antiviral effects of dOTC in combination with the nucleoside RT inhibitors AZT, 3TC, d4T (stavudine) and ddl, the non-nucleoside RT inhibitor nevirapine and the protease inhibitors saquinavir, ritonavir and indinavir was investigated. Two-way drug combination assays were carried out in peripheral blood mononuclear cell (PBMC) cultures by measuring the reduction in p24 viral antigen levels, and data was analysed using the MacSynergy II program. dOTC in combination with 3TC or d4T showed a moderate synergistic effect while all other combinations had an additive interaction.
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Affiliation(s)
- D L Taylor
- Virogen Drug Discovery Ltd, Mill Hill, London, UK.
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Abstract
OBJECTIVE To measure the concentrations of nerve growth factor (NGF) in tissue biopsies taken from subjects with a normal bladder and from patients diagnosed to have idiopathic detrusor instability (associated with a reduction in the density of motor nerves), and to use an in vitro model to study the mechanisms of NGF expression. MATERIALS AND METHODS Biopsy specimens were obtained during endoscopic and open surgery from patients undergoing routine bladder surgery. The patients were divided into two categories based upon urodynamic characterization. The NGF content in samples from 11 normal bladders and seven idiopathic unstable bladders were measured using an enzyme-linked immunosorbent assay. The mechanisms influencing net NGF production were explored using detrusor cells in vitro. RESULTS The mean (SEM) NGF content was significantly higher in unstable tissues, at 0.96 (0.05) pg/microg protein, than in the normal bladder, at 0.53 (0.05) pg/microg protein. In the cell model, acetylcholine (10 micromol/L), noradrenaline (1 and 10 micromol/L) and ATP (1 micromol/L) caused a significant increase in net NGF production; acetylcholine at 1 micromol/L had no effect. Direct stimulation of protein kinase C (PKC) by phorbol ester (33 ng/mL) or elevation of cAMP using forskolin (10 micromol/L) increased NGF, suggesting that at least two intracellular pathways (PKC- and PKA-dependent) are involved. The expression of c-Fos was increased by phorbol 12-myristate 13-acetate added before NGF, suggesting that c-Fos may be involved in regulating NGF production. CONCLUSION These data suggest a role for NGF in the physiology and pathophysiology of the human bladder, and indicate some of the possible mechanisms which might regulate NGF production.
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Affiliation(s)
- R Tanner
- Department of Surgery, School of Surgical and Reproductive Sciences, The Medical School, University of Newcastle, Newcastle upon Tyne, UK
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Englert H, Small-McMahon J, Davis K, O'Connor H, Chambers P, Brooks P. Male systemic sclerosis and occupational silica exposure-a population-based study. Aust N Z J Med 2000; 30:215-20. [PMID: 10833113 DOI: 10.1111/j.1445-5994.2000.tb00810.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND The continuing uncertainty about the silica-systemic sclerosis relationship led to the investigation of its role as a disease determinant in a large population-based study of systemic sclerosis. AIMS To compare the frequency, socioeconomic and educational status, age-specific prevalence and duration of occupational silica exposure in males with and without systemic sclerosis. To assess the temporal relationship between exposure and disease onset. To estimate disease latency. To compare disease characteristics between silica-exposed and non-silica-exposed male cases. METHODS The study was case-control in design. The exposure variable was occupational silica exposure as assessed by an occupational health officer blinded to case/control status and the outcome variable was systemic sclerosis. The employed instrument comprised either a standardised telephone questionnaire (interviewed cases and controls) or medical records (deceased or living-status-unknown cases). RESULTS Sixty of 160 cases (37.5%) and 11 of 83 (13.3%) controls had occupational silica exposure (OR=3.93; 1.84-8.54). Comparison of data between 64 interviewed cases and all controls demonstrated initial occupational silica exposure occurring before age 40, comparable educational status but significantly different cumulative socioeconomic status with cases being over-represented in semi-skilled and unskilled occupations. Cross-sectional 'current' occupational data underestimated cumulative silica exposure by more than 50%. Silica exposure uniformly preceded onset of second disease symptoms and disease diagnosis. In most, it also preceded onset of first disease symptoms. Disease latency approximated two decades. No disease features distinguished silica-associated systemic sclerosis from idiopathic systemic sclerosis. The duration of silica exposure in the interviewed silica-exposed cases did not significantly exceed that of silica-exposed controls. CONCLUSIONS Male systemic sclerosis displays socioeconomic dependence. Silica is a disease determinant in male systemic sclerosis, with disease features including a long latency and clinical characteristics indistinguishable from idiopathic disease. Cross-sectional 'current' occupational data underestimate cumulative occupational silica exposure.
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Abstract
OBJECTIVE To compare and quantify, in a morphological study, the changes that occur in the connective tissue elements (elastin and collagen), muscle fibre diameters and nerve densities between normal, idiopathic and neuropathic bladders. MATERIALS AND METHODS Bladder tissue was obtained from 27 patients undergoing cystectomy for carcinoma, from 12 with idiopathic instability and from seven neuropathic patients who were undergoing ileocystoplasty. A combination of histochemical and immunohistochemical techniques were used to detect detrusor muscle, connective tissue and nerve profiles in the bladder tissue. RESULTS In both idiopathic and neuropathic bladder tissue the structural changes were highly punctate. From the density of nerve profiles, three areas were defined: (i) apparently unaffected normal fascicles with a high density of nerves, no hypertrophy of the muscle and no infiltration of elastin and collagen. The nerve density in these areas was similar to that in normal bladder tissue. (ii) Fascicles with a low density of nerve profiles, muscle hypertrophy but no connective tissue infiltration. (iii) Areas with few nerve profiles, muscle hypertrophy and extensive elastin and collagen infiltration within the fascicles. The mean (sem) density of nerve profiles in control tissue was 752 (53) nerves/mm2 and in the idiopathic bladders was 905 (91), 81 (20) and 74 (38) nerves/mm2 in the three defined areas, respectively. In the neuropathic tissues the nerve profile densities were 672 (249), 57 (23) and 37 (28) nerves/mm2, respectively. Fibre diameter, elastin and collagen content and nerve density were measured in normal and unstable bladder tissue using these three defined areas. The mean (sem) fibre diameter was 6.81 (0.52) in normal bladder; in idiopathic bladder tissue the fibre diameters in the three areas were 6.72 (0.62), 7.06 (0.62) and 7.34 (1.15) micrometer, respectively, and in neuropathic bladders were 6.75 (0.62), 8.24 (0.62) and 9.35 (0.62) micrometer, respectively. The relative areas of elastin were 0.79 (0.70), 0.56 (0.45) and 18.3 (4.1)% for the control, normal and affected areas of the neuropathic bladders, respectively, and the relative areas of collagen were 3.5 (1.3), 6.15 (3.6) and 15.7 (5. 0)%, respectively. The pattern was similar in idiopathic bladders. CONCLUSION These observations suggest that the primary defect in the idiopathic and neuropathic bladders is a loss of nerves accompanied by a hypertrophy of the cells. These changes may continue with further hypertrophy of the cells and an increased production of elastin and collagen within the muscle fascicles.
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Affiliation(s)
- R G Charlton
- Department of Histopathology, The Freeman Hospital, Newcastle upon Tyne, UK
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Ahmadian G, Chambers P, Easton AJ. Detection and characterization of proteins encoded by the second ORF of the M2 gene of pneumoviruses. J Gen Virol 1999; 80 ( Pt 8):2011-2016. [PMID: 10466798 DOI: 10.1099/0022-1317-80-8-2011] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The nucleotide sequence of the M2 gene of pneumonia virus of mice (PVM) was determined. The sequence showed that the gene encoded a protein of 176 amino acids with a predicted molecular mass of 20165 Da from a major ORF, which is smaller than the equivalent proteins encoded by human, bovine and ovine respiratory syncytial (RS) viruses. The PVM M2 protein is conserved, having 41% similarity to the equivalent human RS virus protein. In common with the M2 genes of the RS viruses and avian pneumovirus (APV), the PVM mRNA also contained a second ORF (ORF2) that partially overlaps the first ORF and which is capable of encoding a 98 residue polypeptide. No significant sequence identity could be detected between the putative M2 ORF2 proteins of PVM, APV and the RS viruses. The expression of the M2 ORF2 proteins of the pneumoviruses was investigated by using monospecific antisera raised against GST fusion proteins. Western blot analysis demonstrated the presence of polypeptides encoded by M2 ORF2 of PVM and RS virus corresponding with those predicted by in vitro translation studies, but this was not the case for APV. The PVM polypeptide was present as three distinct products in vivo. The PVM and RS virus polypeptides were also detected in cells by immunofluorescence, which showed that both were present in the cytoplasm with a degree of localization in inclusion bodies. No APV M2 ORF2 protein could be detected in vivo. The RS virus M2 ORF2 polypeptide was shown to accumulate during infection and the potential implications of this are discussed.
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Affiliation(s)
- G Ahmadian
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK1
| | - P Chambers
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK1
| | - A J Easton
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK1
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Taylor DL, Ahmed PS, Chambers P, Tyms AS, Bedard J, Duchaine J, Falardeau G, Lavallée JF, Brown W, Rando RF, Bowlin T. Pyrido [1,2a] indole derivatives identified as novel non-nucleoside reverse transcriptase inhibitors of human immunodeficiency virus type 1. Antivir Chem Chemother 1999; 10:79-86. [PMID: 10335402 DOI: 10.1177/095632029901000204] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Pyrido [1,2a] indole derivatives were identified as potent inhibitors of human immunodeficiency virus type 1 (HIV-1) replication during a random screening programme. The compounds showed no antiviral activity against HIV-2 or in cells chronically infected with HIV-1, but had good inhibitory effect against purified HIV-1 reverse transcriptase (RT) in an in vitro assay. They were therefore classified as non-nucleoside RT inhibitors (NNRTI). The synthesis of additional compounds of the same class revealed a structure-activity relationship. The most potent compound of the series, BCH-1, had similar antiviral activity to the licensed NNRTI nevirapine against laboratory strains of HIV-1 cultured in cell lines and primary clinical isolates of HIV-1 cultured in peripheral blood mononuclear cells. However, BCH-1 showed greater cytotoxicity, providing a narrow selectivity index in the order of 35. BCH-1 had equivalent antiviral activity against viruses resistant to the nucleoside RT inhibitors zidovudine, didanosine and lamivudine and maintained better activity (less than threefold change in IC50) than nevirapine against viruses resistant to a range of NNRTIs with the single amino acid changes L100I, K103N, E138K or Y181C in the RT. Viruses with single V106A or Y188C amino acid changes showed five- and 10-fold resistance to BCH-1, respectively, in contrast to nevirapine, which had a > 100-fold change in IC50. However, virus with both V106A and Y188C amino acid changes showed higher level resistance (> 15-fold) to BCH-1. Virus with > 10-fold resistance to BCH-1 was rapidly selected for after growth in increasing concentrations of compound and was shown to be cross-resistant to nevirapine. Sequencing of this virus revealed two amino acid changes at positions 179 (V to D) and 181 (Y to C) in the RT. BCH-1 represents a new class of NNRTI, which may act as a lead to identify more selective compounds.
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Abstract
BACKGROUND Systemic sclerosis prevalence and mortality estimates have demonstrated wide variability. The sole Australian study published to date demonstrated high prevalence rates when compared to overseas estimates. The prevalence and mortality findings reported in this paper derive from a larger study which addressed the distribution and determinants of systemic sclerosis within Sydney. AIMS To determine systemic sclerosis prevalence and mortality rates within Sydney over 15 years, 1974-88. METHODS Cases were ascertained from multiple sources including death certificates, hospitals, physicians, vascular surgeons' and dermatologists' private practices, a systemic sclerosis self-help group and private medical laboratories. RESULTS Overall, 715 cases were identified. Females comprised 77% (95% CI: 74-80) of cases. Disease of the limited subtype accounted for 79% (95% CI: 76-82) of all systemic sclerosis, being relatively more frequent in living than deceased cases, and in females than males. Crude prevalence estimates appeared to rise between 1975 (4.52/100,000 95% CI:3.75-5.29/100,000) and 1988 (8.62/100,000 95% CI:7.64-9.60/100,000) as did estimates of diffuse disease. However, diffuse disease prevalence, when expressed as a proportion of total disease prevalence, showed no significant temporal change. Although crude mortality rates also showed apparent temporal increases (0.24/100,000 in 1975 to 0.80/100,000 in 1988) standardised mortality rates showed less convincing trends (0.41/100,000 in 1976 and 0.40/100,000 in 1988). Death certificate-derived mortality rates provided relatively large underestimates of total mortality. However, these underestimates were relatively constant over time. CONCLUSIONS This study has demonstrated systemic sclerosis prevalence and mortality rates comparable to overseas estimates, consistently higher prevalence and mortality rates in females than males, proportionally higher rates of diffuse disease in males than females and in deceased cases than living cases, a diffuse: limited disease ratio apparently stable over time, apparently increasing temporal prevalence and mortality rates and, by implication, rising incidence rates. The observed temporal rise in diffuse disease prevalence and the absence of a convincing fall in diffuse disease mortality suggests a rising temporal incidence rate of diffuse disease. Standardised mortality rates demonstrated less consistent trends than did crude mortality rates and failed to demonstrate convincing declines in mortality subsequent to the introduction of ACE inhibitors for management of systemic sclerosis renal disease. Death certificate-derived systemic sclerosis mortality rates considerably and consistently underestimated systemic sclerosis-all cause mortality.
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Affiliation(s)
- H Englert
- Rheumatology Department, Royal North Shore Hospital, Sydney, NSW
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Englert H, Small-McMahon J, Chambers P, O'Connor H, Davis K, Manolios N, White R, Dracos G, Brooks P. Familial risk estimation in systemic sclerosis. Aust N Z J Med 1999; 29:36-41. [PMID: 10200811 DOI: 10.1111/j.1445-5994.1999.tb01586.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Familial systemic sclerosis has been rarely reported. Assumptions have therefore been made implying no familial disease aggregation. This study critically challenges the assumption using a methodical population-based epidemiological approach to quantify the prevalence and characteristics of familial systemic sclerosis. METHODS In this retrospective cohort study the systemic sclerosis prevalence in first degree family members was compared between 715 systemic sclerosis patients (710 families) and 371 randomly ascertained age and gender group-matched general practice controls (371 families). These data, obtained by telephone questionnaire (living patients) or medical records review (deceased patients and untraceable patients of unknown living status), were validated, where necessary, and expressed in terms of relative risk, absolute risk and population point prevalence. RESULTS Systemic sclerosis affecting first degree members was validated in ten of 710 families. Reporting of systemic disease in another four more distant family members, and the co-occurrence of systemic and localised disease in three families was also documented. Observed and expected disease subtype concordance was 80% (44-97%) and 68% respectively and the female predominance among familial cases was similar to that for non-familial disease. The risk of disease in a subsequent first degree relative was compared to the risk in an initial first degree family member. Its estimated magnitude was wide (11-158). However, use of population prevalence data to determine the expected number of systemic sclerosis patients in the negative cohorts' families suggests the higher estimate is more realistic. Despite the high magnitude, the absolute disease risk in first degree family members remained low--approximating 1%. The population prevalence of familial systemic sclerosis approximated 1.4/million. CONCLUSIONS This study substantially increases the otherwise small list of documented instances of familial systemic sclerosis. More importantly, it quantifies the risk for the first time, ranking it as the disease's most powerful determinant identified to date.
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Affiliation(s)
- H Englert
- Department of Rheumatology, Royal North Shore Hospital, Sydney, NSW
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41
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Abstract
The role of intracellular Ca2+ release in the activation of human bladder smooth muscle is controversial. We have measured the expression of mRNA encoding for the ryanodine receptor (RyR) isoforms (RyR1, RyR2 and RyR3) in isolated human detrusor smooth muscle. mRNA for RyR2 was detected in all samples but no mRNA for RyR1 or RyR3 could be found. Human bladder smooth muscle cells in culture are unresponsive to caffeine, suggesting the absence of a functional RyR system. However, mRNA encoding for RyR2 was detected in these cells. Using saponin-permeabilized cells, a Ruthenium Red-sensitive Ca(2+)-dependent 45Ca2+ release could be demonstrated from the sarcoplasmic reticulum (SR). These data confirm the functional presence of Ca(2+)-induced Ca2+ release (CICR) in cells and suggest that the properties of the RyR2 isoform in human detrusor may change when the cells are maintained in culture. The implications of these observations to detrusor smooth muscle function are discussed.
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Affiliation(s)
- P Chambers
- Department of Surgery, Medical School, University of Newcastle upon Tyne, UK
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42
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Abstract
The effects of hypotonic solutions on intracellular Ca2+ were determined on primary cultures of human detrusor smooth muscle cells. In the presence of external Ca2+, changing from a solution containing 290 mosmol l-1 to one containing 240 mosmol l-1 (80% normal tonicity) activated a rise in intracellular Ca2+. If the exposure to 240 mosmol l-1 was followed by exposure to 150 mosmol l-1 (50% normal tonicity) a further increase in Ca2+ was noted. Exposure to hypotonic solutions which contained nominally zero Ca2+ also resulted in a rise in intracellular Ca2+, suggesting that mechanical perturbation of the surface membrane can mobilize Ca2+ directly from intracellular stores. Stimulation of cells with a brief exposure to agonist (histamine, 5 microM) in the nominal absence of external Ca2+ produced a release of Ca2+ from intracellular stores. Under these conditions the response to a subsequent hypotonic stimulation was small or absent. These observations suggest that hypotonic stress induces a mobilization of Ca2+ from the same store as that activated by agonist. Detailed analysis of data from individual bladders revealed that there were significant differences between cells cultured from normal bladders and those from bladders with detrusor instability. On exposure to 240 mosmol l-1 cells from unstable bladders gave larger responses than cells from normal bladders. However, exposure of cells from unstable bladders to a subsequent stimulus of 150 mosmol l-1 resulted in a smaller rise in Ca2+ than was observed with normal cells. Overall, these data suggest that isolated detrusor smooth muscle cells are sensitive to membrane stretch by hyposmotic solutions and that the mechanisms involved include the direct mobilization of intracellular Ca2+. The data also suggest that there may be differences in the responsiveness of cells isolated from stable and unstable bladders.
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Affiliation(s)
- P Chambers
- Department of Surgery, Medical School, University of Newcastle, Newcastle upon Tyne, UK
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Abstract
We have assessed, in vitro, the effect of KTP laser strike on the reinforced laryngeal mask airway (RLMA) under a variety of conditions. At power densities normally encountered in clinical practice, using a divergent KTP laser beam, the RLMA could not be penetrated and did not ignite with laser strike. The RLMA was penetrated at a high power density of 6.94 W mm-2 after 45-60 s. A flame appeared over the RLMA shaft at this power density after 12-35 s. The black marker line on the RLMA shaft was somewhat more vulnerable to the effects of laser strike. The flow of oxygen and nitrous oxide within the shaft did not appreciably alter the laser-resistant properties of the RLMA. The RLMA cuff was more vulnerable to laser strike than was the shaft and was penetrated at very low power densities. Filling the cuff with saline had a protective effect and penetration did not occur at power densities which caused penetration of air-filled cuffs (0.37 W mm-2).
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Affiliation(s)
- J J Pandit
- Department of Anaesthetics, Milton Keynes General Hospital
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Abstract
The nucleotide sequences of the genes encoding the matrix (M) protein and the small hydrophobic (SH) protein of pneumonia virus of mice (PVM) are described. The matrix protein gene contains a large open reading frame encoding polypeptide of 257 residues which shows considerable (38.6-42.1%) amino acid identity with the matrix proteins of other pneumoviruses. The matrix gene also contains a second, smaller, open reading frame (ORF) as seen with the equivalent genes of other pneumoviruses. The PVM second open reading frame is capable of encoding a polypeptide of 46 residues and shows no significant similarity with the proteins encoded by the equivalent open reading frames of the other pneumoviruses. The gene adjacent to that encoding the matrix protein encodes a small, 92 residue, polypeptide which has a central hydrophobic domain and is structurally similar to the small hydrophobic protein of respiratory syncytial virus.
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Affiliation(s)
- A J Easton
- Department of Biological Sciences, University of Warwick, Coventry, UK
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45
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Abstract
It has been suggested that the isolation and culture of human detrusor smooth muscle cells may provide useful insights into the physiology of the intact detrusor muscle. In the present paper, data are presented from cultured human bladder smooth muscle cells isolated from small, routinely available biopsies. Since the initiation of contractions involves a rise in intracellular Ca2+, this study has focused on the mechanisms involved in the rise of Ca2+ in cultured cells. Exposure of cells to bathing solutions with elevated K+ concentrations resulted in an increase in Ca2+ consistent with the presence of voltage-activated Ca2+ channels. Agonists, including carbachol, histamine and ATP, also activated repetitive transient increases in Ca2+ in the presence and absence of external Ca2+. Spontaneous Ca2+ transients were recorded in 31% of cells isolated from normal bladders. Such spontaneous and agonist-induced oscillations were not abolished in depolarized cells, suggesting that the mechanisms underlying the oscillations are not dependent on the cyclical operation of voltage-operated Ca2+ channels. However, the spontaneous activity was inhibited by the Ca2+ blocker verapamil, pointing to the presence of Ca2+ channels. The operation of an IP3-sensitive Ca2+ release mechanism was examined using saponin-permeabilized cells, which demonstrated that IP3 increased the rate of 45Ca2+ efflux. The conclusion from this study is that many of the mechanisms described in the intact tissue are operational in cultured cells.
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Affiliation(s)
- P Chambers
- Department of Surgery, Medical School, University of Newcastle upon Tyne, UK
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Mellon JK, Cook S, Chambers P, Neal DE. Transforming growth factor alpha and epidermal growth factor levels in bladder cancer and their relationship to epidermal growth factor receptor. Br J Cancer 1996; 73:654-8. [PMID: 8605103 PMCID: PMC2074354 DOI: 10.1038/bjc.1996.114] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We have examined levels of epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha) in neoplastic and non-neoplastic bladder tissue using a standard radioimmunoassay technique. Tumour samples had much higher TGF-alpha levels compared with EGF and TGF-alpha levels in malignant tissue were significantly higher than in benign bladder samples. There was, in addition, a difference in mean EGF levels from 'normal' bladder samples from non-tumour bearing areas of bladder in patients with bladder cancer compared with 'normal' bladder tissue obtained at the time of organ retrieval surgery. Levels of EGF and TGF-alpha did not correlate with levels of EGF receptor (EGFR) as determined by a radioligand binding method but levels of TGF-alpha > 10 ng gm-1 of tumour tissue did correlate with EGFR positivity defined using immunohistochemistry. These data suggest that TGF-alpha is the likely ligand for EGFR in bladder tumours.
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Affiliation(s)
- J K Mellon
- Department of Urology, Freeman Hospital, Newcastle upon Tyne, UK
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Chambers P. Neurobehavioral methods and effects in occupational and environmental health Edited by Shunchi Araki (Ed.), Academic Press, San Diego. 1020 pp. $49. Toxicol Lett 1995. [DOI: 10.1016/0378-4274(95)90207-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Randhawa JS, Chambers P, Pringle CR, Easton AJ. Nucleotide sequences of the genes encoding the putative attachment glycoprotein (G) of mouse and tissue culture-passaged strains of pneumonia virus of mice. Virology 1995; 207:240-5. [PMID: 7871733 DOI: 10.1006/viro.1995.1071] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The sequences of the genes encoding the putative attachment (G) proteins of pathogenic (strain J3666) mouse lung-passaged and nonpathogenic (strain 15) tissue culture-passaged strains of pneumonia virus of mice (PVM) have been determined. In both cases the major polypeptide was synthesised from the second open reading frame (ORF), a feature also found in the G gene of respiratory syncytial (RS) virus, another pneumovirus. However, the ORFs of the G genes of the two PVM strains were initiated at different nucleotide positions in the mRNA and comparison of hydrophobicity profiles revealed the presence of the putative amino-terminal cytoplasmic domain in the strain J3666 G protein and its absence in the predicted G protein of PVM strain 15. In common with the G protein of RS virus, the gene product of both PVM strains contained a high serine, threonine, and proline content. Indirect immunofluorescence analysis of BSC-1 cells expressing the G gene products confirmed the surface location of the proteins. Thus, the absence of a cytoplasmic domain does not interfere with the translocation of the G protein of PVM strain 15. In vitro translation of mRNA from the two PVM genes directed the synthesis of a larger polypeptide with the G gene of PVM strain J3666 than was seen with strain 15 G gene. In addition, a second protein was seen with strain J3666 mRNA which was the same size as the strain 15 G protein.
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Affiliation(s)
- J S Randhawa
- Department of Biological Sciences, University of Warwick, Coventry, United Kingdom
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Chambers P. Closure of the donor defect following radial free flap transfer using full thickness ipsilateral forearm skin. Br J Oral Maxillofac Surg 1994. [DOI: 10.1016/0266-4356(94)90062-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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