Christina M Buchanan

University of Auckland, Auckland, Auckland, New Zealand

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Publications (7)20.01 Total impact

  • Article: A brief relaxation intervention reduces stress and improves surgical wound healing response: a randomised trial.
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    ABSTRACT: Psychological stress has been shown to impair wound healing, but experimental research in surgical patients is lacking. This study investigated whether a brief psychological intervention could reduce stress and improve wound healing in surgical patients. This randomised controlled trial was conducted at a surgical centre. Inclusion criteria were English-speaking patients over 18 years booked to undergo elective laparoscopic cholecystectomy; exclusion criteria were cancellation of surgery, medical complications, and refusal of consent. Seventy five patients were randomised and 15 patients were excluded; 60 patients completed the study (15 male, 45 female). Participants were randomised to receive standard care or standard care plus a 45-min psychological intervention that included relaxation and guided imagery with take-home relaxation CDs for listening to for 3 days before and 7 days after surgery. In both groups ePTFE tubes were inserted during surgery and removed at 7 days after surgery and analysed for hydroxyproline as a measure of collagen deposition and wound healing. Change in perceived stress from before surgery to 7-day follow-up was assessed using questionnaires. Intervention group patients showed a reduction in perceived stress compared with the control group, controlling for age. Patients in the intervention group had higher hydroxyproline deposition in the wound than did control group patients (difference in means 0.35, 95% CI 0.66-0.03; t(43)=2.23, p=0.03). Changes in perceived stress were not associated with hydroxyproline deposition. A brief relaxation intervention prior to surgery can reduce stress and improve the wound healing response in surgical patients. The intervention may have particular clinical application for those at risk of poor healing following surgery.
    Brain Behavior and Immunity 06/2011; 26(2):212-7. · 4.72 Impact Factor
  • Article: A novel two-chain IGF-II-derived peptide from purified β-cell granules.
    Christina M Buchanan, Anthony R J Phillips, Garth J S Cooper
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    ABSTRACT: Insulin-like growth factor II (IGF-II) is a potent mitogen that regulates prenatal growth and development in both humans and rodents. Its role in post-natal life is less clear although immunohistochemical studies have observed IGF-II-like immunoreactivity (IGF-II-LI) associated with insulin-producing pancreatic β-cells. Here we isolated secretory granules from a β-cell line, βTC6-F7, and characterized the nature of the IGF-II-LI located therein. Secretory granules were isolated from cultured mouse βTC6-F7 cells by ultracentrifugation. Granule protein content was separated by reversed-phase HPLC, and assayed for IGF-II (radioimmunoassay) prior to identification by gas-phase NH(2)-terminal sequencing and MALDI-TOF MS. Effects of glucose incorporation into muscle glycogen were determined by incubating with isolated rat soleus muscle strips. βTC6-F7 cells contained 60 ± 8 pmol of IGF-II-LI per 10⁶ cells compared to 340 ± 44 pmol insulin-LI per 10⁶ cells. IGF-II immunoreactive fractions were found to contain an IGF-II-like molecule with a molecular mass of 6847.6 Da. The protein was found to be a two-chain insulin-like product of Igf2 that corresponds to mouse des(37-40)IGF-II, which we termed 'vesiculin'. This molecule was also detectable in βTC6-F7 cells by intact-cell mass spectrometry. Mouse vesiculin evoked concentration-dependent stimulation of muscle glycogen synthesis ex vivo with an EC(50) value of 131 nM ± 1.35. Vesiculin, des(37-40)IGF-II, is a novel two-chain insulin-like hormone and the major "IGF-II-like" peptide found in purified mouse βTC6-F7 secretory granules. It stimulated ex vivo muscle glycogen synthesis with an efficacy greater than or equal to the intrinsic potency of IGF-II when compared to insulin derived from the same species.
    Growth hormone & IGF research: official journal of the Growth Hormone Research Society and the International IGF Research Society 10/2010; 20(5):360-6. · 2.35 Impact Factor
  • Article: Proteins associated with immunopurified granules from a model pancreatic islet beta-cell system: proteomic snapshot of an endocrine secretory granule.
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    ABSTRACT: beta-Cell granules contain proteins involved in fuel regulation, which when altered, contribute to metabolic disorders including diabetes mellitus. We analyzed proteins present in purified granules from the INS-1E beta-cell model. Fifty-one component proteins were identified by LC-MS/MS including hormones, granins, protein processing components, cellular trafficking components, enzymes implicated in cellular metabolism and chaperone proteins. These findings may increase understanding of granule secretion and the processes leading to protein aggregation and beta-cell death in type-2 diabetes.
    Journal of Proteome Research 01/2009; 8(1):178-86. · 5.11 Impact Factor
  • Article: The proteome of rodent mesenteric lymph.
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    ABSTRACT: Mesenteric lymph contributes to normal homeostasis and has an emerging role in the pathogenesis of multiple organ dysfunction syndrome. The aim of this study was to define the proteome of normal rodent mesenteric lymph in the fasted and fed states. Eight male Wistar rats fed a standard rodent diet were randomized to two groups. Group 1 (fasted, n = 4) were fasted for 24 h before anesthetized collection of mesenteric lymph. Group 2 (fed, n = 4) were allowed ad libitum access to food before lymph collection. Mesenteric lymph was subjected to proteomic analysis using iTRAQ and liquid chromatography-tandem mass spectrometry (LC-MS/MS). One hundred fifty proteins, including 26 hypothetical proteins, were identified in this study. All proteins were identified in lymph from both the fasted and fed states. The relative distribution profiles of protein functional classes in the mesenteric lymph differed significantly from that reported for plasma. The most abundant classes identified in lymph were protease inhibitors (16%) and proteins related to innate immunity (12%). In conclusion, this study provides the first detailed description of the normal mesenteric lymph proteome in the fed and fasted states using iTRAQ and LC-MS/MS.
    AJP Gastrointestinal and Liver Physiology 10/2008; 295(5):G895-903. · 3.43 Impact Factor
  • Article: Probing the urinary proteome of severe acute pancreatitis
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    ABSTRACT: Background. Proteinuria is a characteristic feature of severe acute pancreatitis (SAP) that may allow unique insights into AP pathophysiology. This study used a proteomic approach to differentiate the abundant urinary proteins in AP patients. Materials and methods. Urine samples were prospectively collected from 4 groups (5 SAP, 10 mild gallstone AP, 7 mild alcohol AP, 7 controls). Reverse-phase high-performance liquid chromatography (RP-HPLC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (LC MALDI) were used to identify urinary proteins and determine any differences between the groups. Results. There were 17 RP-HPLC major peaks in SAP groups of significantly greater absorbance magnitude than the corresponding ones in mild and control groups. Various mass spectrometry methods were used to identify 21 different parent proteins from these SAP peaks. They included fibrinogen, serum amyloid A, insulin and calcitonin gene-related peptides. There were no identifiable protein peaks at the corresponding elution times in the mild pancreatitis and controls samples. Discussion. Proteomic techniques offer a unique unexplored window into AP pathophysiology. The utility of these proteins as markers of pancreatitis severity now need to be further investigated and the identification extended to the full urinary proteome as technology permits.
    HPB 11/2007; 9(6):447 - 455. · 1.60 Impact Factor
  • Article: Direct visualisation of peptide hormones in cultured pancreatic islet alpha- and beta-cells by intact-cell mass spectrometry.
    Christina M Buchanan, Arpita S Malik, Garth J S Cooper
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    ABSTRACT: The application of intact-cell mass spectrometry (ICM) by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry to achieve direct protein-profiling of bacterial species is now well established. However, this methodology has not to our knowledge been applied to the analysis of mammalian cells in routine culture. Here, we describe a novel application of ICM by which we have identified proteins in intact cells from two lines representative of pancreatic islet alpha- and beta-cells. Adherent alphaTC1 clone 9 and betaTC6 F7 cells were harvested into phosphate-buffered saline (PBS) using enzyme-free dissociation buffer before 1 microL of cell suspension was spotted onto MALDI plates. Cells were overlaid with sinapinic acid then washed with pure water before application of a final coat of sinapinic acid. Data in the 2000-20,000 m/z range were acquired in linear mode on a Voyager DE-Pro mass spectrometer. The proteins which ionised were composed in large part of peptide hormones (e.g. insulin and glucagon) known to be packaged into the secretory granules of the beta- and alpha-cells respectively. However, in addition to visualising the peptides expected to be associated with these cells, a mass consistent with oxyntomodulin was identified in the cultured alpha-cells, a finding not previously reported to our knowledge. In summary, this paper describes, for the first time, a rapid and direct method useful for identifying secretory products in intact endocrine cells.
    Rapid Communications in Mass Spectrometry 02/2007; 21(21):3452-8. · 2.79 Impact Factor
  • Article: A novel two-chain IGF-II-derived peptide from purified β-cell granules
    Christina M. Buchanan, Anthony R.J. Phillips, Garth J.S. Cooper
    [show abstract] [hide abstract]
    ABSTRACT: ObjectiveInsulin-like growth factor II (IGF-II) is a potent mitogen that regulates prenatal growth and development in both humans and rodents. Its role in post-natal life is less clear although immunohistochemical studies have observed IGF-II-like immunoreactivity (IGF-II-LI) associated with insulin-producing pancreatic β-cells. Here we isolated secretory granules from a β-cell line, βTC6-F7, and characterized the nature of the IGF-II-LI located therein.DesignSecretory granules were isolated from cultured mouse βTC6-F7 cells by ultracentrifugation. Granule protein content was separated by reversed-phase HPLC, and assayed for IGF-II (radioimmunoassay) prior to identification by gas-phase NH2-terminal sequencing and MALDI-TOF MS. Effects of glucose incorporation into muscle glycogen were determined by incubating with isolated rat soleus muscle strips.ResultsβTC6-F7 cells contained 60 ± 8 pmol of IGF-II-LI per 106 cells compared to 340 ± 44 pmol insulin-LI per 106 cells. IGF-II immunoreactive fractions were found to contain an IGF-II-like molecule with a molecular mass of 6847.6 Da. The protein was found to be a two-chain insulin-like product of Igf2 that corresponds to mouse des(37–40)IGF-II, which we termed ‘vesiculin’. This molecule was also detectable in βTC6-F7 cells by intact-cell mass spectrometry. Mouse vesiculin evoked concentration-dependent stimulation of muscle glycogen synthesis ex vivo with an EC50 value of 131 nM ± 1.35.ConclusionsVesiculin, des(37–40)IGF-II, is a novel two-chain insulin-like hormone and the major “IGF-II-like” peptide found in purified mouse βTC6-F7 secretory granules. It stimulated ex vivo muscle glycogen synthesis with an efficacy greater than or equal to the intrinsic potency of IGF-II when compared to insulin derived from the same species.
    Growth Hormone & IGF Research.