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Tadross JA, Patterson M, Suzuki K, Beale KE, Boughton CK, Smith KL, Moore S, Ghatei MA, Bloom SR. Augurin stimulates the hypothalamo-pituitary-adrenal axis via the release of corticotrophin-releasing factor in rats. Br J Pharmacol 2010; 159:1663-71. [PMID: 20233222 DOI: 10.1111/j.1476-5381.2010.00655.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE The functional characterization of secreted peptides can provide the basis for the development of novel therapeutic agents. Augurin is a recently identified secreted peptide of unknown function expressed in multiple endocrine tissues, and in regions of the brain including the hypothalamus. We therefore investigated the effect of hypothalamic injection of augurin on the hypothalamo-pituitary-adrenal (HPA) axis in male Wistar rats. EXPERIMENTAL APPROACH Augurin was given as a single injection into the third cerebral ventricle (i.c.v.) or into the paraventricular nucleus (iPVN) of the hypothalamus. Circulating hormone levels were then measured by radioimmunoassay. The effect of augurin on the release of hypothalamic neuropeptides was investigated ex vivo using hypothalamic explants. The acute effects of iPVN augurin on behaviour were also assessed. KEY RESULTS i.c.v. injection of augurin significantly increased plasma ACTH and corticosterone, compared with vehicle-injected controls, but had no effect on other hypothalamo-pituitary axes hormones. Microinjection of lower doses of augurin into the PVN caused a similar increase in plasma ACTH and corticosterone, without significant alteration in behavioural patterns. Incubation of hypothalamic explants with increasing doses of augurin significantly elevated corticotrophin-releasing factor (CRF) and arginine vasopressin release. In vivo, peripheral injection of a CRF(1/2) receptor antagonist prevented the rise in ACTH and corticosterone caused by i.c.v. augurin injection. CONCLUSIONS AND IMPLICATIONS These data suggest that augurin stimulates the release of ACTH via the release of hypothalamic CRF. Pharmacological manipulation of the augurin system may therefore be a novel target for regulation of the HPA axis.
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Keun HC, Sidhu J, Pchejetski D, Lewis JS, Marconell H, Patterson M, Bloom SR, Amber V, Coombes RC, Stebbing J. Serum Molecular Signatures of Weight Change during Early Breast Cancer Chemotherapy. Clin Cancer Res 2009; 15:6716-23. [DOI: 10.1158/1078-0432.ccr-09-1452] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Patterson M, Hughes S, Combrié S, Tran NVQ, De Rossi A, Gabet R, Jaouën Y. Disorder-induced coherent scattering in slow-light photonic crystal waveguides. PHYSICAL REVIEW LETTERS 2009; 102:253903. [PMID: 19659077 DOI: 10.1103/physrevlett.102.253903] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 02/27/2009] [Indexed: 05/13/2023]
Abstract
Light transmission measurements and frequency-delay reflectometry maps for GaAs photonic crystal membranes are presented and analyzed, showing the transition from propagation with a well-defined group velocity to a regime completely dominated by disorder-induced coherent scattering. Employing a self-consistent optical scattering theory, with only statistical functions to describe the structural disorder, we obtain excellent agreement with the experiments using no fitting parameters. Our experiments and theory together provide clear physical insight into naturally occurring light localization and multiple coherent-scattering phenomena in slow-light waveguides.
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Stebbing J, Keun HC, Sidhu J, Patterson M, Bloom SR, Amber V, Coombes C, Marconell H, Pshezhetskiy D. Serum molecular signatures of weight change during early breast cancer chemotherapy. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e11534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e11534 Background: Weight gain in women receiving chemotherapy following breast cancer diagnosis has negative implications on quality of life and those who gain weight during treatment appear to be at higher risk of disease recurrence. The mechanism(s) implicated in chemotherapy associated weight gain are poorly understood. Methods: To investigate this further, we assessed the metabolic, cytokine and appetite related peptide alterations before and during adjuvant FEC chemotherapy for early breast cancer in post-menopausal women, and correlated these with body mass measurements. Specifically, we performed global metabolic profiling (metabonomics/ metabolomics) using 1H nuclear magnetic resonance spectroscopy of sequential sera, examined ghrelin immunoreactivity, performed radioimmunoassays for glucagon like peptide-1 (GLP-1) and peptide YY (PYY) and electro-chemiluminescent cytokine analyses (tumor necrosis factor-α and interleukin-6; TNF-α, IL-6) on the sequential samples. Results: In those who gained ≥ 1.5kg (on average ∼5% of initial body weight), several metabolite levels were positively associated with weight change, in particular lactate which was 55% greater in patients with increased body weight during chemotherapy compared to those with stable weight during chemotherapy (p<0.01; the pre-specified primary end-point). A significant inverse relationship was also observed between levels of TNF-α and weight change group (ρ 0.476, p<0.05). Baseline lactate, alanine and body fat were all prognostic for weight gain (ROC AUC >0.77, p<0.05). No significant associations were observed between any other parameter and weight gain, nor any parameter and tumor burden, including cytokine and appetite peptide alterations. Conclusions: Metabonomics identifies pathways perturbed during early chemotherapy for breast cancer, and establishes a positive association between serum lactate, body fat, TNF-α and substantive weight changes during chemotherapy. Interventions that target these processes may be clinically useful in breast cancer. No significant financial relationships to disclose.
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Paff Z, Flesch L, Davies S, Patterson M. Multidisciplinary Simulation Training for Transplant Staff to Improve Response to Inpatient Medical Emergencies. Biol Blood Marrow Transplant 2009. [DOI: 10.1016/j.bbmt.2008.12.458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Thompson EL, Amber V, Stamp GWH, Patterson M, Curtis AE, Cooke JH, Appleby GF, Dhillo WS, Ghatei MA, Bloom SR, Murphy KG. Kisspeptin-54 at high doses acutely induces testicular degeneration in adult male rats via central mechanisms. Br J Pharmacol 2009; 156:609-25. [PMID: 19226253 PMCID: PMC2697701 DOI: 10.1111/j.1476-5381.2008.00061.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Revised: 10/07/2008] [Accepted: 10/10/2008] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE The kisspeptins are critical regulators of reproduction and a therapeutic target for reproductive disease. Intracerebroventricular (i.c.v.) or peripheral injection of kisspeptin potently stimulates the hypothalamic-pituitary gonadal (HPG) axis via gonadotrophin-releasing hormone (GnRH). However, little is known regarding the effects of kisspeptin administration on testicular function. We investigated the mechanism(s) of kisspeptin-induced testicular degeneration in the rat. EXPERIMENTAL APPROACH Kisspeptin-54 (50 nmol.day(-1)) was continuously administered subcutaneously (6 h to 3 days) to male Wistar rats and reproductive hormones and testicular histology analysed. We also investigated the effects of a single subcutaneous injection of 0.5, 5 or 50 nmol kisspeptin-54. In order to determine whether the testicular degeneration observed is peripherally or centrally mediated, we investigated effects of i.c.v. injections of 5 nmol kisspeptin-54 and pre-administered a GnRH-receptor antagonist (cetrorelix) to rats peripherally treated with kisspeptin-54. KEY RESULTS Continuous subcutaneous administration of kisspeptin-54 caused testicular degeneration after only 12 h, when gonadotrophins were still markedly raised, suggesting that the degeneration is independent of the desensitization of the HPG axis to kisspeptin-54. Furthermore, a single subcutaneous injection of kisspeptin-54 caused dose-dependent testicular degeneration. Continuous kisspeptin-54 administration is thus not required to cause testicular degeneration. Pretreatment with cetrorelix blocked kisspeptin-induced testicular degeneration, and a single i.c.v. injection of kisspeptin-54 caused testicular degeneration, suggesting it is GnRH-mediated. CONCLUSIONS AND IMPLICATIONS Kisspeptin-induced testicular degeneration appears to be centrally mediated, and result from acute hyper-stimulation of the HPG axis. Doses must be carefully considered if kisspeptin is to be used therapeutically.
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Vinuela A, Hallett PJ, Reske-Nielsen C, Patterson M, Sotnikova TD, Caron MG, Gainetdinov RR, Isacson O. Implanted reuptake-deficient or wild-type dopaminergic neurons improve ON L-dopa dyskinesias without OFF-dyskinesias in a rat model of Parkinson's disease. Brain 2008; 131:3361-79. [PMID: 18988638 PMCID: PMC2639209 DOI: 10.1093/brain/awn192] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 07/02/2008] [Accepted: 07/29/2008] [Indexed: 11/16/2022] Open
Abstract
OFF-L-dopa dyskinesias have been a surprising side-effect of intrastriatal foetal ventral mesencephalic transplantation in patients with Parkinson's disease. It has been proposed that excessive and unregulated dopaminergic stimulation of host post-synaptic striatal neurons by the grafts could be responsible for these dyskinesias. To address this issue we transplanted foetal dopaminergic neurons from mice lacking the dopamine transporter (DATKO) or from wild-type mice, into a rat model of Parkinson's disease and L-dopa-induced dyskinesias. Both wild-type and DATKO grafts reinnervated the host striatum to a similar extent, but DATKO grafts produced a greater and more diffuse increase in extra-cellular striatal dopamine levels. Interestingly, grafts containing wild-type dopaminergic neurons improved parkinsonian signs to a similar extent as DATKO grafts, but provided a more complete reduction of L-dopa induced dyskinesias. Neither DATKO nor wild-type grafts induced OFF-L-dopa dyskinesias. Behavioural and receptor autoradiography analyses demonstrated that DATKO grafts induced a greater normalization of striatal dopaminergic receptor supersensitivity than wild-type grafts. Both graft types induced a similar downregulation and normalization of PEnk and fosb/Deltafosb in striatal neurons. In summary, DATKO grafts causing high and diffuse extra-cellular dompamine levels do not per se alter graft-induced recovery or produce OFF-L-dopa dyskinesias. Wild-type dopaminergic neurons appear to be the most effective neuronal type to restore function and reduce L-dopa-induced dyskinesias.
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Burnett HC, Nemec S, Patterson M. A review of Florida citrus blight and its association with soil edaphic factors, nutrition andFusarium solani. ACTA ACUST UNITED AC 2008. [DOI: 10.1080/09670878209370749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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McGowan BM, Stanley SA, Donovan J, Thompson EL, Patterson M, Semjonous NM, Gardiner JV, Murphy KG, Ghatei MA, Bloom SR. Relaxin-3 stimulates the hypothalamic-pituitary-gonadal axis. Am J Physiol Endocrinol Metab 2008; 295:E278-86. [PMID: 18492777 PMCID: PMC2519759 DOI: 10.1152/ajpendo.00028.2008] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The hypothalamus plays a key role in the regulation of both energy homeostasis and reproduction. Evidence suggests that relaxin-3, a recently discovered member of the insulin superfamily, is an orexigenic hypothalamic neuropeptide. Relaxin-3 is thought to act in the brain via the RXFP3 receptor, although the RXFP1 receptor may also play a role. Relaxin-3, RXFP3, and RXFP1 are present in the hypothalamic paraventricular nucleus, an area with a well-characterized role in the regulation of energy balance that also modulates reproductive function by providing inputs to hypothalamic gonadotropin-releasing hormone (GnRH) neurons. Other members of the relaxin family are known to play a role in the regulation of reproduction. However, the effects of relaxin-3 on reproductive function are unknown. We studied the role of relaxin-3 in the regulation of the hypothalamo-pituitary-gonadal (HPG) axis. Intracerebroventricular (5 nmol) and intraparaventricular (540-1,620 pmol) administration of human relaxin-3 (H3) in adult male Wistar rats significantly increased plasma luteinizing hormone (LH) 30 min postinjection. This effect was blocked by pretreatment with a peripheral GnRH antagonist. Central administration of human relaxin-2 showed no significant effect on plasma LH. H3 dose-dependently stimulated the release of GnRH from hypothalamic explants and GT(1)-7 cells, which express RXFP1 and RXFP3, but did not influence LH or follicle-stimulating hormone release from pituitary fragments in vitro. We have demonstrated a novel role for relaxin-3 in the stimulation of the HPG axis, putatively via hypothalamic GnRH neurons. Relaxin-3 may act as a central signal linking nutritional status and reproductive function.
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Fu S, Chintala L, Madoff D, Hong DS, Naing A, Moulder SL, Wheler JJ, Ng CS, Lim J, Patterson M, Kurzrock R. A phase I study of hepatic arterial infusion of oxaliplatin plus intravenous fluorouracil, leucovorin, and bevacizumab in patients with predominant hepatic metastases. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.2534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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English PJ, Ashcroft A, Patterson M, Dovey TM, Halford JCG, Harrison J, Eccleston D, Bloom SR, Ghatei MA, Wilding JPH. Metformin prolongs the postprandial fall in plasma ghrelin concentrations in type 2 diabetes. Diabetes Metab Res Rev 2007; 23:299-303. [PMID: 16952199 DOI: 10.1002/dmrr.681] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Weight loss is difficult to achieve in type 2 diabetes and many therapies are associated with weight gain, an effect attenuated by metformin. We studied the effects of metformin on energy expenditure, appetite and the regulation of PYY and ghrelin in type 2 diabetes. METHODS Plasma peptide YY (PYY), ghrelin, resting metabolic rate (RMR), postprandial thermogenesis (PPTG), and appetite ratings were measured at baseline and following a mixed meal in 11 type 2 diabetic subjects treated with diet alone (T2D) and 10 treated with metformin monotherapy (T2MF). The groups were similar in age, gender and adiposity. RESULTS There were no differences in baseline anthropometric, or metabolic variables between the groups. Postprandially, plasma ghrelin fell equally in both groups (23% versus 24.5%, p < 0.05 versus baseline, p = NS between groups) but were reduced for longer in T2MF (below baseline 60-240 min T2MF versus 60-180 min T2D) coincidentally with a prolonged sensation of fullness and suppression of hunger in the metformin-treated group. There were no differences in PYY concentrations, RMR or PPTG. CONCLUSIONS Metformin prolongs the postprandial fall in ghrelin concentrations. These effects may prolong the inter-meal interval, thereby decreasing snack intake and daily energy intake, promoting weight loss.
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Hutchinson A, Cooper KL, Dean JE, McIntosh A, Patterson M, Stride CB, Laurence BE, Smith CM. Use of a safety climate questionnaire in UK health care: factor structure, reliability and usability. Qual Saf Health Care 2007; 15:347-53. [PMID: 17074872 PMCID: PMC2565820 DOI: 10.1136/qshc.2005.016584] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To explore the factor structure, reliability, and potential usefulness of a patient safety climate questionnaire in UK health care. SETTING Four acute hospital trusts and nine primary care trusts in England. METHODS The questionnaire used was the 27 item Teamwork and Safety Climate Survey. Thirty three healthcare staff commented on the wording and relevance. The questionnaire was then sent to 3650 staff within the 13 NHS trusts, seeking to achieve at least 600 responses as the basis for the factor analysis. 1307 questionnaires were returned (36% response). Factor analyses and reliability analyses were carried out on 897 responses from staff involved in direct patient care, to explore how consistently the questions measured the underlying constructs of safety climate and teamwork. RESULTS Some questionnaire items related to multiple factors or did not relate strongly to any factor. Five items were discarded. Two teamwork factors were derived from the remaining 11 teamwork items and three safety climate factors were derived from the remaining 11 safety items. Internal consistency reliabilities were satisfactory to good (Cronbach's alpha > or =0.69 for all five factors). CONCLUSIONS This is one of the few studies to undertake a detailed evaluation of a patient safety climate questionnaire in UK health care and possibly the first to do so in primary as well as secondary care. The results indicate that a 22 item version of this safety climate questionnaire is useable as a research instrument in both settings, but also demonstrates a more general need for thorough validation of safety climate questionnaires before widespread usage.
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McGowan BM, Stanley SA, White NE, Spangeus A, Patterson M, Thompson EL, Smith KL, Donovan J, Gardiner JV, Ghatei MA, Bloom SR. Hypothalamic mapping of orexigenic action and Fos-like immunoreactivity following relaxin-3 administration in male Wistar rats. Am J Physiol Endocrinol Metab 2007; 292:E913-9. [PMID: 17132825 DOI: 10.1152/ajpendo.00346.2006] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The insulin superfamily, characterized by common disulphide bonds, includes not only insulin but also insulin-like peptides such as relaxin-1 and relaxin-3. The actions of relaxin-3 are largely unknown, but recent work suggests a role in regulation of food intake. Relaxin-3 mRNA is highly expressed in the nucleus incertus, which has extensive projections to the hypothalamus, and relaxin immunoreactivity is present in several hypothalamic nuclei. In the rat, relaxin-3 binds and activates both relaxin family peptide receptor 1, which also binds relaxin-1, and a previously orphaned G protein-coupled receptor, RXFP3. These receptors are extensively expressed in the hypothalamus. The aims of these studies were twofold: 1) map the hypothalamic site(s) of the orexigenic action of relaxin-3 and 2) examine the site(s) of neuronal activation following central relaxin-3 administration. After microinjection into hypothalamic sites, human relaxin-3 (H3; 180 pmol) significantly stimulated 0- to 1-h food intake in the supraoptic nucleus (SON), arcuate nucleus (ARC), and the anterior preoptic area (APOA) [SON 0.4+/-0.2 (vehicle) vs. 2.9+/-0.5 g (H3), P<0.001; ARC 0.7+/-0.3 (vehicle) vs. 2.7+/-0.2 g (H3), P<0.05; and APOA 0.8+/-0.1 (vehicle) vs. 2.2+/-0.2 g (H3), P<0.05]. Cumulative food intake was significantly increased<or=8 h following administration into the SON and 4 h into the APOA. A significant increase in Fos-like immunoreactivity was seen in the SON following central relaxin-3 administration. Relaxin-3 stimulates feeding in several hypothalamic nuclei, and these studies provide additional support for relaxin-3 as an important peptide in appetite regulation.
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Milton JE, Sananthanan CS, Patterson M, Ghatei MA, Bloom SR, Frost GS. Glucagon-like peptide-1 (7-36) amide response to low versus high glycaemic index preloads in overweight subjects with and without type II diabetes mellitus. Eur J Clin Nutr 2007; 61:1364-72. [PMID: 17299480 DOI: 10.1038/sj.ejcn.1602654] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND OBJECTIVE Glucagon-like-peptide-1 (7-36) amide (GLP-1) is an insulin secretagogue and potential treatment for type II diabetes mellitus. An alternative to GLP-1 administration is endogenous dietary stimulation. We described a greater GLP-1 release following ingestion of liquids versus solids. We add to this work studying the effect of fluid preloads with differing glycaemic indices (GI) on the metabolic response to a meal. SUBJECTS AND DESIGN GLP-1, insulin and glucose responses were measured in six overweight individuals and six subjects with type II diabetes on three occasions, after preload (milk, low GI; Ovaltine Light, high GI; or water, non-nutritive control) and meal ingestion. RESULTS In people with and without diabetes, the high GI preload produced the greatest glucose incremental area under the curve (IAUC)(0-20), followed by the low GI preload, and water (P<0.001). In both groups, insulin IAUC(0-20) was higher following high and low GI preloads compared with water (NS). In people without diabetes, the GLP-1 response was higher when high and low GI preloads were consumed compared with water (P=0.041), with no significant difference between nutritive preloads. GLP-1 response did not differ between preloads in people with diabetes. Despite initial differences, total IAUCs(0-200) for biochemical variables did not differ by preload. CONCLUSION We confirm that nutritive liquids stimulate GLP-1 to a greater extent than water in subjects without diabetes; however, this does not influence subsequent meal-induced response. The GI of preloads does not influence the degree of GLP-1 stimulation.
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Patterson M, Jones M, Lloyd DA. Development, implementation and prospective evaluation of guidelines for transfer of severely injured children to specialist centres. Br J Surg 2006; 93:1418-23. [PMID: 17016792 DOI: 10.1002/bjs.5356] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Most injured children are appropriately treated at a district general hospital (DGH), but some require transfer to a specialist centre. The objectives of this study were to develop, implement and evaluate triage guidelines for the rapid recognition of injured children who require transfer. METHODS This was a prospective, interventional cohort study of the 592 seriously injured children who presented to five regional DGHs during a 51-month period. A multispecialty steering group representing all participating DGHs developed and implemented the guidelines. Data were collected for 24 months before the guidelines were introduced, over the 3-month implementation period and for 24 months afterwards. Outcome measures were referral and management patterns before and after introduction of the guidelines. RESULTS For level I (unstable) patients, after the implementation of guidelines there was a 29 per cent increase in the proportion of transfers to a specialist centre (from 40 (68 per cent) of 59 to 32 (97 per cent) of 33; P = 0.003), no admissions to a DGH intensive care unit and all 12 operations were performed at a specialist centre. Guideline users indicated that they were familiar with the guidelines. CONCLUSION The introduction of triage guidelines within an effective communication network was associated with changes in the management of severely injured children.
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Druce MR, Neary NM, Small CJ, Milton J, Monteiro M, Patterson M, Ghatei MA, Bloom SR. Subcutaneous administration of ghrelin stimulates energy intake in healthy lean human volunteers. Int J Obes (Lond) 2006; 30:293-6. [PMID: 16247504 DOI: 10.1038/sj.ijo.0803158] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The gastric hormone ghrelin appears a useful agent to stimulate food intake in people with anorexia of illness. The loss of ghrelin's acyl group renders it inactive, thus it has been thought that subcutaneous administration may be problematic. OBJECTIVE To investigate whether human subjects are sensitive to the effects of ghrelin administered by single subcutaneous injection. STUDY DESIGN Randomized, double-blind, placebo-controlled trial. SUBJECTS Sixteen healthy lean volunteers (eight men and eight women). PROTOCOL Fasted subjects received subcutaneous injections of ghrelin (3.6 nmol/kg) or saline. After 30 min, a buffet breakfast was served. RESULTS Ghrelin injection increased energy intake by 27% (ghrelin 5076 +/- 691 kJ versus saline 4230+/-607 kJ, P = 0.04). Ghrelin appeared to enhance the perceived palatability of the food offered (palatability score: ghrelin 81.1 +/- 3.6 versus saline 70.0 +/- 4.4; P = 0.03). CONCLUSIONS These results suggest that subcutaneous ghrelin is effective at stimulating energy intake and improving palatability and may be of direct use in the treatment of appetite loss.
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Patterson M, Murphy KG, Thompson EL, Smith KL, Meeran K, Ghatei MA, Bloom SR. Microinjection of galanin-like peptide into the medial preoptic area stimulates food intake in adult male rats. J Neuroendocrinol 2006; 18:742-7. [PMID: 16965292 DOI: 10.1111/j.1365-2826.2006.01473.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Galanin-like peptide (GALP) is a neuropeptide implicated in the regulation of feeding behaviour, metabolism and reproduction. GALP is an endogenous ligand of the galanin receptors, which are widely expressed in the hypothalamus. GALP is predominantly expressed in arcuate nucleus (ARC) neurones, which project to the paraventricular nucleus (PVN) and medial preoptic area (mPOA). Intracerebroventricular or intraparaventricular (iPVN) injection of GALP acutely increases food intake in rats. The effect of GALP injection into the mPOA on feeding behaviour has not previously been studied. In the present study, intra-mPOA (imPOA) injection of GALP potently increased 0-1-h food intake in rats. The dose-response effect of imPOA GALP administration on food intake was similar to that previously observed following iPVN administration. The effects of GALP (1 nmol) or galanin (1 nmol) on food intake were then compared following injection into the PVN, mPOA, ARC, dorsal medial nucleus (DMN), lateral hypothalamus and rostral preoptic area (rPOA). GALP (1 nmol) increased food intake to a similar degree when injected into the imPOA or iPVN, but produced no significant effect when injected into the ARC, DMN, lateral hypothalamus or rPOA. Similarly, galanin (1 nmol) significantly increased food intake following injection imPOA and iPVN. However, the effect was significantly smaller than that following administration of GALP (1 nmol). Galanin also had no significant effect on food intake when administered into the ARC, DMN, lateral hypothalamus and rPOA. These data suggest that the mPOA and the PVN may have specific roles in mediating the orexigenic effect of GALP and galanin.
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English PJ, Ashcroft A, Patterson M, Dovey TM, Halford JCG, Harrison J, Eccleston D, Bloom SR, Ghatei MA, Wilding JPH. Fasting plasma peptide-YY concentrations are elevated but do not rise postprandially in type 2 diabetes. Diabetologia 2006; 49:2219-21. [PMID: 16832662 DOI: 10.1007/s00125-006-0344-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Accepted: 05/20/2006] [Indexed: 11/26/2022]
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McGowan BM, Stanley SA, Smith KL, Minnion JS, Donovan J, Thompson EL, Patterson M, Connolly MM, Abbott CR, Small CJ, Gardiner JV, Ghatei MA, Bloom SR. Effects of acute and chronic relaxin-3 on food intake and energy expenditure in rats. ACTA ACUST UNITED AC 2006; 136:72-7. [PMID: 16764952 DOI: 10.1016/j.regpep.2006.04.009] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Revised: 03/31/2006] [Accepted: 04/28/2006] [Indexed: 11/20/2022]
Abstract
The effects of acute and repeated intraparaventricular (iPVN) administration of human relaxin-3 (H3) were examined on food intake, energy expenditure, and the hypothalamo-pituitary thyroid axis in male Wistar rats. An acute high dose iPVN injection of H3 significantly increased food intake 1 h post-administration [0.4+/-0.1 g (vehicle) vs 1.6+/-0.5 g (180 pmol H3), 2.4+/-0.5 g (540 pmol H3) and 2.2+/-0.5 g (1,620 pmol H3), p<0.05 for all doses vs vehicle]. Repeated iPVN H3 injection (180 pmol/twice a day for 7 days) significantly increased cumulative food intake in ad libitum fed animals compared with vehicle [211.8+/-7.1 g (vehicle) vs 261.6+/-6.7 g (ad libitum fed H3), p<0.05]. Plasma leptin was increased in the H3 ad libitum fed group. Plasma thyroid stimulating hormone was significantly decreased after acute and repeated administration of H3. These data suggest H3 may play a role in long-term control of food intake.
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Vara Prasad JVN, Boyer FE, Chupak L, Dermyer M, Ding Q, Gavardinas K, Hagen SE, Huband MD, Jiao W, Kaneko T, Maiti SN, Melnick M, Romero K, Patterson M, Wu X. Synthesis and structure-activity studies of novel benzocycloheptanone oxazolidinone antibacterial agents. Bioorg Med Chem Lett 2006; 16:5392-7. [PMID: 16901693 DOI: 10.1016/j.bmcl.2006.07.064] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 07/18/2006] [Accepted: 07/20/2006] [Indexed: 10/24/2022]
Abstract
We describe a novel class of benzocycloheptanone derived oxazolidinone antibacterial agents. The synthesis and antibacterial activities with structure variation is discussed.
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Abstract
See also Robinson A. Open access: the view of a commercial publisher. This issue, pp 1454–60.
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Xu H, Patterson M. Po-Thur Eve General-30: Determination of the optical properties of tissue-simulating phantoms by interstitial frequency domain measurements. Med Phys 2006. [DOI: 10.1118/1.2244657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Pekar J, Patterson M. Po-Thur Eve General-17: Design and Characterization of a CT Scanner for Small Animal Imaging. Med Phys 2006. [DOI: 10.1118/1.2244644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Patterson M, Murphy KG, Thompson EL, Patel S, Ghatei MA, Bloom SR. Administration of kisspeptin-54 into discrete regions of the hypothalamus potently increases plasma luteinising hormone and testosterone in male adult rats. J Neuroendocrinol 2006; 18:349-54. [PMID: 16629833 DOI: 10.1111/j.1365-2826.2006.01420.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Kisspeptin-54 is the peptide product of the KiSS-1 gene and an endogenous agonist of the GPR54 receptor. KiSS-1 was initially discovered as a metastasis suppressor gene, but recent studies demonstrate that the kisspeptin/GPR54 system is a key regulator of the reproductive system. Disrupted GPR54 signalling causes hypogonadotrophic hypogonadism in rodents and man. Intracerebroventricular or peripheral administration of kisspeptin potently stimulates the hypothalamic-pituitary-gonadal (HPG) axis via the hypothalamic gonadotrophin-releasing hormone system. We have investigated the effect of injection of kisspeptin-54 into discrete hypothalamic regions on the HPG axis. To construct a dose-response curve for the effects of intrahypothalamic kisspeptin administration, adult male Wistar rats were cannulated into the medial preoptic area (MPOA) at the level of the organum vasculosum laminae terminalis (OVLT). Kisspeptin-54 was injected into the MPOA at doses of 0.01, 0.1, 1, 10 and 100 pmol. At 60 min following injection of 1, 10 or 100 pmol kisspeptin-54, plasma luteinising hormone (LH) and total testosterone levels were significantly increased. Adult male Wistar rats were then cannulated into the rostral preoptic area at the level of the OVLT (RPOA), the MPOA, the paraventricular (PVN), dorsomedial (DMN) and arcuate hypothalamic nuclei, and the lateral hypothalamic area. A dose of 1 pmol kisspeptin-54 was administered into all areas. The circulating levels of LH and total testosterone were significantly increased 60 min postinjection of kisspeptin-54 into the RPOA, MPOA, PVN and arcuate nucleus. Our results suggest that kisspeptin may mediate its effects on the HPG axis via these regions of the hypothalamus.
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Martin NM, Houston PA, Patterson M, Sajedi A, Carmignac DF, Ghatei MA, Bloom SR, Small CJ. Abnormalities of the somatotrophic axis in the obese agouti mouse. Int J Obes (Lond) 2006; 30:430-8. [PMID: 16172617 DOI: 10.1038/sj.ijo.0803076] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Abnormalities of the melanocortin system produce obesity and increased linear growth. While the obesity phenotype is well characterised, the mechanism responsible for increased linear growth is unclear. The somatotrophic axis was studied in the obese agouti (A(y)/a) mouse as a model of a perturbed melanocortin system. DESIGN Adult obese A(y)/a mice were compared to age- and sex-matched wild-type (WT) controls. Weight and body length (nose-anus) were recorded. Plasma growth hormone (GH), insulin-like growth factor-I (IGFI), insulin and leptin were measured using radioimmunoassay. Since ghrelin is a potent GH secretagogue, plasma ghrelin, stomach ghrelin peptide and stomach ghrelin mRNA expression were studied. Hypothalamic periventricular (PeVN) somatostatin neurones and arcuate (Arc) neuropeptide Y (NPY) neurones inhibit the growth axis, whereas Arc growth hormone-releasing hormone (GHRH) neurones are stimulatory. Therefore, specific hypothalamic expression of somatostatin, NPY and GHRH was measured using quantitative in situ hybridisation. RESULTS Obese A(y)/a mice were significantly heavier and longer than WT controls. Plasma IGFI concentrations were 30% greater in obese A(y)/a mice. Obese A(y) /a mice were hyperinsulinaemic and hyperleptinaemic, yet plasma ghrelin, and stomach ghrelin peptide and mRNA were significantly reduced. In obese A(y)/a mice, PeVN somatostatin and Arc NPY mRNA expression were reduced by 50% compared to WT controls, whereas Arc GHRH mRNA expression was unchanged. CONCLUSION Increased body length in adult obese A(y)/a mice may result from reduced Arc NPY and PeVN somatostatin mRNA expression, which in turn, may increase plasma IGFI concentrations and upregulate the somatotrophic axis.
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