1
|
Affiliation(s)
- David A Singleton
- University of Liverpool, Institutes of Infection, Veterinary Science and Ecology, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE
| | - P J Noble
- University of Liverpool, Institutes of Infection, Veterinary Science and Ecology, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE
| | - Beth Brant
- University of Liverpool, Institutes of Infection, Veterinary Science and Ecology, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE
| | - Gina L Pinchbeck
- University of Liverpool, Institutes of Infection, Veterinary Science and Ecology, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE
| | - Alan D Radford
- University of Liverpool, Institutes of Infection, Veterinary Science and Ecology, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE
| |
Collapse
|
2
|
Singleton DA, Noble PJ, Radford AD, Brant B, Pinchbeck GL, Greenberg D, Appleton C, Jewell C, Newton R, Cuartero CT, Sánchez-Vizcaíno F. Prolific vomiting in dogs. Vet Rec 2020; 186:191. [PMID: 32054807 DOI: 10.1136/vr.m553] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- David A Singleton
- University of Liverpool, Institutes of Infection and Global Health and Veterinary Science, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE
| | - P J Noble
- University of Liverpool, Institutes of Infection and Global Health and Veterinary Science, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE
| | - Alan D Radford
- University of Liverpool, Institutes of Infection and Global Health and Veterinary Science, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE
| | - Beth Brant
- University of Liverpool, Institutes of Infection and Global Health and Veterinary Science, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE
| | - Gina L Pinchbeck
- University of Liverpool, Institutes of Infection and Global Health and Veterinary Science, Leahurst Campus, Chester High Road, Neston, Wirral CH64 7TE
| | | | | | - Chris Jewell
- The Liverpool Vets, 11 Cleveland Square, Liverpool L1 5BE
| | - Richard Newton
- CHICAS, Furness College, Lancaster University, Lancaster LA1 4YG
| | | | | |
Collapse
|
3
|
Affiliation(s)
- Heather Davies
- University of Liverpool, Leahurst Campus, Chester High Road, Neston CH64 7TE
| | - P J Noble
- University of Liverpool, Leahurst Campus, Chester High Road, Neston CH64 7TE
| | - Gina Pinchbeck
- University of Liverpool, Leahurst Campus, Chester High Road, Neston CH64 7TE
| | - David Killick
- University of Liverpool, Leahurst Campus, Chester High Road, Neston CH64 7TE
| |
Collapse
|
4
|
Smith SL, Singleton DA, Noble PJ, Radford AD, Brant B, Pinchbeck GL, Appleton C, Jewell C, Newton R, Cuartero CT, Sánchez-Vizcaíno F. Possible cause of outbreak of prolific vomiting in dogs. Vet Rec 2020; 186:324. [PMID: 32165525 DOI: 10.1136/vr.m972] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Shirley L Smith
- Institutes of Infection and Global Health and Veterinary Science, Leahurst Campus, University of Liverpool, Chester High Road, Neston, Wirral CH64 7TE
| | - David A Singleton
- Institutes of Infection and Global Health and Veterinary Science, Leahurst Campus, University of Liverpool, Chester High Road, Neston, Wirral CH64 7TE
| | - P J Noble
- Institutes of Infection and Global Health and Veterinary Science, Leahurst Campus, University of Liverpool, Chester High Road, Neston, Wirral CH64 7TE
| | - Alan D Radford
- Institutes of Infection and Global Health and Veterinary Science, Leahurst Campus, University of Liverpool, Chester High Road, Neston, Wirral CH64 7TE
| | - Beth Brant
- Institutes of Infection and Global Health and Veterinary Science, Leahurst Campus, University of Liverpool, Chester High Road, Neston, Wirral CH64 7TE
| | - Gina L Pinchbeck
- Institutes of Infection and Global Health and Veterinary Science, Leahurst Campus, University of Liverpool, Chester High Road, Neston, Wirral CH64 7TE
| | | | - Chris Jewell
- CHICAS, Furness College, Lancaster University, Lancaster LA1 4YG
| | - Richard Newton
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU
| | - Carmen Tamayo Cuartero
- Bristol Veterinary School, University of Bristol, Churchill Building, Langford Campus, Bristol BS40 5DU
| | - Fernando Sánchez-Vizcaíno
- Bristol Veterinary School, University of Bristol, Churchill Building, Langford Campus, Bristol BS40 5DU
| |
Collapse
|
5
|
Affiliation(s)
- Nicola Robinson
- VPIS, 2nd Floor, Godfree Court, Apex Yard, 29 Long Lane, London SE1 4PL
| | - Bethaney Brant
- SAVSNET, University of Liverpool, Chester High Road, Neston, Cheshire CH64 7TE
| | - Alan Radford
- SAVSNET, University of Liverpool, Chester High Road, Neston, Cheshire CH64 7TE
| | - P J Noble
- SAVSNET, University of Liverpool, Chester High Road, Neston, Cheshire CH64 7TE
| | - Gina Pinchbeck
- SAVSNET, University of Liverpool, Chester High Road, Neston, Cheshire CH64 7TE
| |
Collapse
|
6
|
Sánchez-Vizcaíno F, Wardeh M, Heayns B, Singleton DA, Tulloch JSP, McGinley L, Newman J, Noble PJ, Day MJ, Jones PH, Radford AD. Canine babesiosis and tick activity monitored using companion animal electronic health records in the UK. Vet Rec 2016; 179:358. [PMID: 27484328 PMCID: PMC5099196 DOI: 10.1136/vr.103908] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2016] [Indexed: 11/12/2022]
Abstract
Recent publications highlighting autochthonous Babesia canis infection in dogs from Essex that have not travelled outside the UK are a powerful reminder of the potential for pathogen emergence in new populations. Here the authors use electronic health data collected from two diagnostic laboratories and a network of 392 veterinary premises to describe canine Babesia cases and levels of Babesia concern from January 2015 to March 2016, and the activity of ticks during December 2015–March 2016. In most areas of the UK, Babesia diagnosis in this population was rare and sporadic. In addition, there was a clear focus of Babesia cases in the affected area in Essex. Until February 2016, analysis of health records indicated only sporadic interest in Babesia largely in animals coming from overseas. Following media coverage in March 2016, there was a spike in owner concern that was geographically dispersed beyond the at-risk area. Tick activity (identified as ticks being removed from animals in veterinary consultations) was consistent but low during the period preceding the infections (<5 ticks/10,000 consultations), but increased in March. This highlights the use of electronic health data to describe rapidly evolving risk and concern that follows the emergence of a pathogen.
Collapse
Affiliation(s)
- F Sánchez-Vizcaíno
- Institutes of Infection and Global Health University of Liverpool, Leahurst Campus, Chester High Road, Neston, S. Wirral CH64 7TE, UK
| | - M Wardeh
- Institutes of Infection and Global Health University of Liverpool, Leahurst Campus, Chester High Road, Neston, S. Wirral CH64 7TE, UK
| | - B Heayns
- Institutes of Infection and Global Health University of Liverpool, Leahurst Campus, Chester High Road, Neston, S. Wirral CH64 7TE, UK
| | - D A Singleton
- Institutes of Infection and Global Health University of Liverpool, Leahurst Campus, Chester High Road, Neston, S. Wirral CH64 7TE, UK
| | - J S P Tulloch
- Institutes of Infection and Global Health University of Liverpool, Leahurst Campus, Chester High Road, Neston, S. Wirral CH64 7TE, UK
| | - L McGinley
- Institutes of Infection and Global Health University of Liverpool, Leahurst Campus, Chester High Road, Neston, S. Wirral CH64 7TE, UK
| | - J Newman
- Institutes of Infection and Global Health University of Liverpool, Leahurst Campus, Chester High Road, Neston, S. Wirral CH64 7TE, UK
| | - P J Noble
- Veterinary Science, University of Liverpool, Leahurst Campus, Chester High Road, Neston, S. Wirral CH64 7TE, UK
| | - M J Day
- University of Bristol, School of Veterinary Sciences, Langford, Bristol BS40 5DU, UK
| | - P H Jones
- Institutes of Infection and Global Health University of Liverpool, Leahurst Campus, Chester High Road, Neston, S. Wirral CH64 7TE, UK
| | - A D Radford
- Institutes of Infection and Global Health University of Liverpool, Leahurst Campus, Chester High Road, Neston, S. Wirral CH64 7TE, UK
| |
Collapse
|
7
|
Radford AD, Noble PJ, Coyne KP, Gaskell RM, Jones PH, Bryan JGE, Setzkorn C, Tierney Á, Dawson S. Antibacterial prescribing patterns in small animal veterinary practice identified via SAVSNET: the small animal veterinary surveillance network. Vet Rec 2011; 169:310. [PMID: 21911433 DOI: 10.1136/vr.d5062] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In this study, data from veterinary clinical records were collected via the small animal veterinary surveillance network (SAVSNET). Over a three-month period, data were obtained from 22,859 consultations at 16 small animal practices in England and Wales: 69 per cent from dogs, 24 per cent from cats, 3 per cent from rabbits and 4 per cent from miscellaneous species. The proportion of consults where prescribing of antibacterials was identified was 35.1 per cent for dogs, 48.5 per cent for cats and 36.6 per cent for rabbits. Within this population, 76 per cent of antibacterials prescribed were β-lactams, including the most common group of clavulanic acid-potentiated amoxicillin making up 36 per cent of the antibacterials prescribed. Other classes included lincosamides (9 per cent), fluoroquinolones and quinolones (6 per cent) and nitroimidazoles (4 per cent). Vancomycin and teicoplanin (glycopeptide class), and imipenem and meropenem (β-lactam class) prescribing was not identified. Prescribing behaviour varied between practices. For dogs and cats, the proportion of consults associated with the prescription of antibacterials ranged from 0.26 to 0.55 and 0.41 to 0.73, respectively.
Collapse
Affiliation(s)
- A D Radford
- University of Liverpool, Institute of Infection and Global Health and School of Veterinary Science, Leahurst Campus, Chester High Road, Neston, South Wirral, CH64 7TE, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Radford A, Tierney A, Coyne KP, Gaskell RM, Noble PJ, Dawson S, Setzkorn C, Jones PH, Buchan IE, Newton JR, Bryan JGE. Developing a network for small animal disease surveillance. Vet Rec 2010; 167:472-4. [PMID: 20871079 DOI: 10.1136/vr.c5180] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
9
|
|
10
|
Abstract
Late sodium current in cardiac cells is very small compared with the fast component, but as it flows throughout the action potential it may make a substantial contribution to sodium loading during each cardiac cycle. Late sodium current may contribute to triggering arrhythmia in two ways: by causing repolarisation failure (early after depolarisations); and by triggering late after depolarisations attributable to calcium oscillations in sodium-calcium overload conditions. Reduction of late sodium current would therefore be expected to have therapeutic benefits, particularly in disease states such as ischaemia in which sodium-calcium overload is a major feature.
Collapse
Affiliation(s)
- D Noble
- University Laboratory of Physiology, Parks Road, Oxford OX1 3PT, UK.
| | | |
Collapse
|
11
|
Abstract
The experimental and clinical possibilities for studying cardiac arrhythmias in human ventricular myocardium are very limited. Therefore, the use of alternative methods such as computer simulations is of great importance. In this article we introduce a mathematical model of the action potential of human ventricular cells that, while including a high level of electrophysiological detail, is computationally cost-effective enough to be applied in large-scale spatial simulations for the study of reentrant arrhythmias. The model is based on recent experimental data on most of the major ionic currents: the fast sodium, L-type calcium, transient outward, rapid and slow delayed rectifier, and inward rectifier currents. The model includes a basic calcium dynamics, allowing for the realistic modeling of calcium transients, calcium current inactivation, and the contraction staircase. We are able to reproduce human epicardial, endocardial, and M cell action potentials and show that differences can be explained by differences in the transient outward and slow delayed rectifier currents. Our model reproduces the experimentally observed data on action potential duration restitution, which is an important characteristic for reentrant arrhythmias. The conduction velocity restitution of our model is broader than in other models and agrees better with available data. Finally, we model the dynamics of spiral wave rotation in a two-dimensional sheet of human ventricular tissue and show that the spiral wave follows a complex meandering pattern and has a period of 265 ms. We conclude that the proposed model reproduces a variety of electrophysiological behaviors and provides a basis for studies of reentrant arrhythmias in human ventricular tissue.
Collapse
Affiliation(s)
- K H W J ten Tusscher
- Department of Theoretical Biology, Utrecht University, 3584 CH Utrecht, The Netherlands.
| | | | | | | |
Collapse
|
12
|
Sugiura Y, Makita N, Li L, Noble PJ, Kimura J, Kumagai Y, Soeda T, Yamamoto T. Cold induces shifts of voltage dependence in mutant SCN4A, causing hypokalemic periodic paralysis. Neurology 2003; 61:914-8. [PMID: 14557559 DOI: 10.1212/01.wnl.0000086820.54065.a0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [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: 11/15/2022] Open
Abstract
BACKGROUND The authors reported a mutation, P1158S, of the human skeletal muscle sodium channel gene (SCN4A) in a family with cold-induced hypokalemic periodic paralysis (hypoKPP) and myotonia. OBJECTIVE To identify mechanisms of temperature dependency in this channelopathy. METHODS Using the amphotericin B perforated patch clamp method, sodium currents were recorded at 22 and 32 degrees C from the wild-type (WT) and P1158S mutant SCN4A expressed in tsA201 cells. Computer simulation was performed, incorporating the gating parameters of the P1158S mutant SCN4A. RESULTS P1158S mutant SCN4A exhibited hyperpolarizing shifts in voltage dependence of both activation and inactivation curves at a cold temperature and a slower rate of inactivation than the WT. Computer simulation reproduced the abnormal skeletal muscle electrical activities of both paralysis at a low potassium concentration in the cold and myotonia at a normal potassium concentration. CONCLUSIONS Both paralysis and myotonia are attributable to the biophysical properties of the SCN4A mutation associated with hypoKPP. This is the first report of an SCN4A mutation that exhibits temperature-dependent shifts of voltage dependence in sodium channel gating.
Collapse
Affiliation(s)
- Y Sugiura
- Department of Neurology, Fukushima Medical University School of Medicine, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
13
|
|
14
|
Pagliocca A, Wroblewski LE, Ashcroft FJ, Noble PJ, Dockray GJ, Varro A. Stimulation of the gastrin-cholecystokinin(B) receptor promotes branching morphogenesis in gastric AGS cells. Am J Physiol Gastrointest Liver Physiol 2002; 283:G292-9. [PMID: 12121875 DOI: 10.1152/ajpgi.00056.2002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Epithelial organization is maintained by cell proliferation, migration, and differentiation. In the case of the gastric epithelium, at least some of these events are regulated by the hormone gastrin. In addition, gastric epithelial cells are organized into characteristic tubular structures (the gastric glands), but the cellular mechanisms regulating the organization of tubular structures (sometimes called branching morphogenesis) are uncertain. In the present study, we examined the role of the gastrin-cholecystokinin(B) receptor in promoting branching morphogenesis of gastric epithelial cells. When gastric cancer AGS-G(R) cells were cultured on plastic, gastrin and PMA stimulated cell adhesion, formation of lamellipodia, and extension of long processes in part by activation of protein kinase C (PKC) and phosphatidylinositol (PI)-3 kinase. Branching morphogenesis was not observed in these circumstances. However, when cells were cultured on artificial basement membrane, the same stimuli increased the formation of organized multicellular arrays, exhibiting branching morphogenesis. These effects were reversed by inhibitors of PKC but not of PI-3 kinase. We conclude that, in the presence of basement membrane, activation of PKC by gastrin stimulates branching morphogenesis.
Collapse
Affiliation(s)
- A Pagliocca
- Physiological Laboratory, University of Liverpool, United Kingdom
| | | | | | | | | | | |
Collapse
|
15
|
Abstract
Stimulation of airway myocytes by contractile agents such as acetylcholine (ACh) activates a Ca2+-activated Cl- current (I(ClCa)) which may play a key role in calcium homeostasis of airway myocytes and hence in airway reactivity. The aim of the present study was to model I(ClCa) in airway smooth muscle cells using a computerised model previously designed for simulation of cardiac myocyte functioning. Modelling was based on a simple resistor-battery permeation model combined with multiple binding site activation by calcium. In order to validate the model, a combination of equations, used to mimic [Ca2+]i response to ACh stimulation, were incorporated into the model. The results indicate that the model developed in this article accounts for experimental recordings and electrophysiological characteristics of this current in airway smooth muscle cells, with parameter values consistent with those calculated from experimental data. Such a model may thus be used to predict I(ClCa) functioning, though additional experimental data from airway myocytes would be useful to more accurately determine some parameter values of the model.
Collapse
Affiliation(s)
- E Roux
- Laboratoire de Physiologie cellulaire respiratoire, EMI 9937, Université Victor, Segalen Bordeaux 2, France.
| | | | | | | |
Collapse
|
16
|
Varro A, Noble PJ, Wroblewski LE, Bishop L, Dockray GJ. Gastrin-cholecystokinin(B) receptor expression in AGS cells is associated with direct inhibition and indirect stimulation of cell proliferation via paracrine activation of the epidermal growth factor receptor. Gut 2002; 50:827-33. [PMID: 12010885 PMCID: PMC1773243 DOI: 10.1136/gut.50.6.827] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND Activation of the gastrin-cholecystokinin(B) (CCK(B)) receptor stimulates cell proliferation and increases production of ligands for the epidermal growth factor receptor (EGF-R). AIMS To determine the role of gastrin-CCK(B) activation in stimulation of cell proliferation via paracrine activation of EGF-R. METHODS AGS cells were transfected with the gastrin-CCK(B) receptor (AGS-G(R) cells) or with green fluorescent protein (AGS-GFP cells). Proliferation was determined by [(3)H] thymidine incorporation, flow cytometry, and cell counting. RESULTS Gastrin inhibited proliferation of AGS-G(R) cells by delaying entry into S phase. However, when AGS-G(R) cells were cocultured with AGS-GFP cells, gastrin stimulated proliferation of the latter. Immunoneutralisation and pharmacological studies using metalloproteinase and kinase inhibitors indicated that the proliferative response was mediated by paracrine stimulation of EGF-R and activation of the mitogen activated protein kinase pathway through release of heparin binding EGF. CONCLUSIONS Gastrin can directly inhibit, and indirectly stimulate, proliferation of gastric AGS cells.
Collapse
Affiliation(s)
- A Varro
- Physiological Laboratory, University of Liverpool, Liverpool, UK.
| | | | | | | | | |
Collapse
|
17
|
Mangoni ME, Fontanaud P, Noble PJ, Noble D, Benkemoun H, Nargeot J, Richard S. Facilitation of the L-type calcium current in rabbit sino-atrial cells: effect on cardiac automaticity. Cardiovasc Res 2000; 48:375-92. [PMID: 11090833 DOI: 10.1016/s0008-6363(00)00182-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE The L-type Ca(2+) current (I(Ca,L)) contributes to the generation and modulation of the pacemaker action potential (AP). We investigated facilitation of I(Ca,L) in sino-atrial cells. METHODS Facilitation was studied in regularly-beating cells isolated enzymatically from young albino rabbits (0.8-1 kg). We used the whole-cell patch-clamp technique to vary the frequency of the test depolarizations evoked at -10 mV or the conditioning diastolic membrane potential prior to the test pulse. RESULTS High frequencies (range 0.2-3.5 Hz) slowed the decay kinetics of I(Ca,L) evoked from a holding potential (HP) of -80 mV in 68% of cells resulting in a larger Ca(2+) influx during the test pulse. The amount of facilitation increased progressively between 0.2 and 3.0 Hz. When the frequency was changed from 0.1 to 1 Hz, the averaged increase in the time integral of I(Ca,L) was 27+/-7% (n=22). Application of conditioning voltages between -80 and -50 mV induced similar facilitation of I(Ca,L) in 73% of cells. The maximal increase of Ca(2+) entry occurred between -60 and -50 mV, and was on average 38+/-14% for conditioning prepulses of 5 s in duration (n=15). Numerical simulations of the pacemaker activity showed that facilitation of I(Ca,L) promotes stability of sino-atrial rate by enhancing Ca(2+) entry, thus establishing a negative feedback control against excessive heart rate slowing. CONCLUSION Facilitation of I(Ca,L) is present in rabbit sino-atrial cells. The underlying mechanism reflects modulation of I(Ca,L) decay kinetics by diastolic membrane potential and frequency of depolarization. This phenomenon may provide an important regulatory mechanism of sino-atrial automaticity.
Collapse
Affiliation(s)
- M E Mangoni
- UPR 1142 CNRS, Institut de Génétique Humaine, 141 rue de la Cardonille, Cedex 5, Montpellier, France
| | | | | | | | | | | | | |
Collapse
|
18
|
Abstract
OBJECTIVE To emphasise the value of computed tomography even in the absence of symptoms in a case of penetrating injury of the upper eyelid. METHODS Case report. RESULTS Although clinically asymptomatic, penetration of upper eyelid was associated with intracranial penetration that left a track in the brain parenchyma. CONCLUSIONS Computed tomography of orbit and brain is an important investigation, even in seemingly trivial eyelid injury, to reveal the full extent of the damage.
Collapse
Affiliation(s)
- S Dinakaran
- Department of Ophthalmology, Doncaster Royal Infirmary
| | | |
Collapse
|
19
|
Abstract
BACKGROUND & AIMS GATA transcription factors may regulate gene expression in developing tissues, including gut epithelium. In the stomach, their expression has been linked to regulation of proton pump genes. However, GATA consensus sequences also occur in the promoter of the histidine decarboxylase gene, located in enterochrommafin-like cells. The aim of this study was to determine if GATA factors are located in gastric endocrine cells and to examine their expression during development and in response to changes in the gastric luminal environment. METHODS Polymerase chain reaction cloning, Northern blot, and gel shift assays were used to examine GATA expression in gastric endocrine cells; changes in GATA messenger RNA during development and in response to fasting, feeding, and gastric achlorhydria were determined by Northern blot. RESULTS GATA-6 was expressed strongly in rodent gastric endocrine cell fractions, in a human ECL cell tumor, and in an endocrine cell line (STC-1) derived from gut epithelium; proteins from STC-1 cells bound specifically to GATA consensus sequences in the human histidine decarboxylase promoter. GATA messenger RNA abundance was up-regulated during terminal differentiation of the rat stomach and on feeding after a fast. CONCLUSIONS The GATA-6 transcription factor is expressed in gastric endocrine cells and is a potential regulator of gastric differentiation and of genes involved in the response to feeding.
Collapse
Affiliation(s)
- R Dimaline
- Physiological Laboratory, University of Liverpool, England
| | | | | | | | | | | |
Collapse
|
20
|
Dimaline R, Miller SM, Evans D, Noble PJ, Brown P, Poat JA. Expression of immediate early genes in rat gastric myenteric neurones: a physiological response to feeding. J Physiol 1995; 488 ( Pt 2):493-9. [PMID: 8568687 PMCID: PMC1156687 DOI: 10.1113/jphysiol.1995.sp020983] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
1. Expression of the immediate early genes c-fos, c-jun and c-myc in rat stomach in response to feeding and gastric distension was examined by Northern blot analysis and in situ hybridization. 2. Refeeding of fasted rats induced a transient increase in c-fos mRNA abundance in gastric corpus and antrum that was sixfold within 15 min and declined within 4 h. The response was not mediated by gastrinergic or muscarinic cholinergic mechanisms; it was reduced but not abolished by hexamethonium. No changes in expression of c-jun, c-myc or the constitutively expressed protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were observed. 3. In conscious rats prepared with a gastric fistula, gastric distension with nutritive and non-nutritive solutions at a physiological pressure for 30 min induced expression of c-fos, c-jun and c-myc, but not GAPDH. 4. Messenger RNA encoding c-fos was localized by in situ hybridization to gastric myenteric neurones of animals that underwent gastric distension, but not of undistended controls. 5. The results suggest that expression of c-fos in gastric myenteric neurones is an early response to the physiological stretching of the stomach wall that accompanies feeding. With supraphysiological distension, other immediate early genes may be recruited.
Collapse
Affiliation(s)
- R Dimaline
- Physiological Laboratory, University of Liverpool, UK
| | | | | | | | | | | |
Collapse
|
21
|
Abstract
A previous report has described the presence of t-[35S]-butylbicyclophosphorothionate binding sites and GABA-gated Cl- flux in the human neuroblastoma IMR-32 cell line. We now report the further characterisation of this binding site and, even more important, the identification of the GABAA receptor alpha 3 sub-unit expressed in these cells. Cell membranes prepared from IMR-32 cells were screened by immunoblotting for reactivity with various GABAA receptor alpha subunit-specific antibodies. Of these, only anti-Cys alpha 3 454-467 antibodies recognised specifically and in a dose-dependent manner an immunoreactive band. This M(r) 58,000 immunoreactive species and the N-deglycosylated derivatives were both coincident with the respective homologues found in both calf cerebral cortex membranes and purified receptor preparations. This is the first report of the identification of a specific GABAA receptor subunit expressed in a human cell line, and it therefore provides a convenient model for the study of receptor structure and regulation.
Collapse
Affiliation(s)
- P J Noble
- Department of Pharmaceutical Chemistry, School of Pharmacy, London, England
| | | | | | | | | |
Collapse
|
22
|
Noble PJ. HIV infection. N Z Med J 1991; 104:236. [PMID: 2052233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
23
|
Ghanta VK, Noble PJ, Brown ME, Cox PJ, Hiramoto NS, Hiramoto RN. Alloreactivity. I. Effects of age and thymic hormone treatment on cell-mediated immunity in C57B1/6NNia mice. Mech Ageing Dev 1983; 22:309-19. [PMID: 6415352 DOI: 10.1016/0047-6374(83)90085-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
C57B1/6NNia mice 1, 12, and 24 months old showed loss of cellular-mediated cytotoxicity with aging. Treatment of the three age groups with different thymic hormone preparations effected their cellular mediated cytotoxicity differently. When cytotoxicity of the thymic hormone treated groups was compared to that of the physiological saline treated group, 1-month-old mice treated with serum thymic factor (FTS) at 1 microgram/mouse and 10 ng/mouse had significantly higher activity, and lower to similar activities at 12 and 24 months; TP5 (active fragment of thymopoietin) at 1 microgram and 10 ng caused significantly higher activity in 1-month-old mice, and lower to higher and significantly lower to similar activity at 12 and 24 months, respectively; TM4 (an analogue of TP5) at 1 ng showed significantly depressed activity in 1-month-old mice, and significantly enhanced activity in 12- and 24-month-old mice; thymosin at 10 micrograms and 1 microgram had slightly lower, but not significant, depression at 1 month, similar activities at 12 months and significantly depressed to higher activity at 24 months. Unimmunized control mice showed significant protection in the 12-month-old mice in comparison to 1- and 24-month-old mice. Different hormone preparations showed age- and dose-dependent effects on the ability of spleen cells to kill P815 mastocytoma. Partial restoration of cytotoxicity was observed in 24-month-old mice treated with FTS, TP5 and thymosin fraction V.
Collapse
|
24
|
Schnitzerling HJ, Noble PJ, Macqueen A, Dunham RJ. RESISTANCE OF THE BUFFALO FLY, HAEMATOBIA IRRITANS EXIGUA (DE MEIJERE), TO TWO SYNTHETIC PYRETHROIDS AND DDT. ACTA ACUST UNITED AC 1982. [DOI: 10.1111/j.1440-6055.1982.tb01769.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
25
|
|
26
|
|