ABSTRACT
The aim of this study was to develop and evaluate an online, interprofessional education programme for clinicians commencing work in rural mental health services in New South Wales, Australia. Twenty-eight participants, including nurses, psychologists, social workers and occupational therapists, completed a 24-week education programme (Introduction to Rural Mental Health Practice programme) that orientated clinicians to working in rural settings. The online programme included an orientation to online learning and clinical skills such as risk assessment, therapeutic communication and de-escalation skills applied in rural settings. Twenty-four participants provided pre- and post-evaluation responses that were matched and analysed using paired t-tests to identify any significant differences in mean scores across the domains of interest. Fifty per cent (n= 13) of participants had a background in nursing and 49% were allied health clinicians (psychologists, social workers and occupational therapists). Statistically significant improvements (P < 0.05) were detected in participant confidence in responding to common mental health problems, knowledge about the role of different services in rural mental health care, perceived safety of work and perceived self-efficacy in dealing with challenging or aggressive behaviours. The Introduction to Rural Mental Health Practice programme was successful in orienting clinicians to rural mental health but the small sample size highlights the need to evaluate the programme with a larger cohort of rural clinicians. The attrition at the early stages of the study highlights significant challenges in the retention of rural clinicians in online education programmes. Factors that promoted participation and retention included the provision of study leave and orientation to the online environment.
Subject(s)
Computer-Assisted Instruction/methods , Education, Distance/organization & administration , Education, Nursing, Continuing/organization & administration , Psychiatric Nursing/education , Rural Health Services/organization & administration , Adult , Attitude of Health Personnel , Female , Humans , Male , Mental Health Services/organization & administration , Middle Aged , New South Wales , Nursing Education Research , Program Evaluation , Surveys and Questionnaires , Young AdultABSTRACT
Subsurface drip irrigation systems apply effluent from onsite wastewater systems in a more uniform manner at a lower rate than has been possible with other effluent dispersal methods. The effluent is dispersed in a biologically active part of the soil profile for optimal treatment and where the water and nutrients can be utilized by landscape plants. Container tests were performed to determine the fate of water and nitrogen compounds applied to packed loamy sand, sandy loam, and silt loam soils. Nitrogen removal rates measured in the container tests ranged from 63 to 95% despite relatively low levels of available carbon. A Hydrus 2D vadose zone model with nitrification and denitrification rate coefficients calculated as a function of soil moisture content fit the container test results reasonably well. Model results were sensitive to the denitrification rate moisture content function. Two-phase transport parameters were needed to model the preferential flow conditions in the finer soils. Applying the model to generic soil types, the greatest nitrogen losses (30 to 70%) were predicted for medium to fine texture soils and soils with restrictive layers or capillary breaks. The slow transport with subsurface drip irrigation enhanced total nitrogen losses and plant nitrogen uptake opportunity.
Subject(s)
Models, Theoretical , Nitrogen/chemistry , Waste Disposal, Fluid , Groundwater/chemistry , Soil/chemistry , Water Pollutants, ChemicalABSTRACT
INTRODUCTION: Emergency Departments (EDs) are often the first point of contact for people with acute mental health problems. The impact of the Mental Health Emergency Care (MHEC) online learning program on the knowledge and skills development of clinicians and support staff was evaluated, and options for sustainable implementation of the program were proposed. METHODS: Participants were recruited from the four rural health services and the rural areas of one metropolitan health service in New South Wales, Australia. The MHEC course was conducted online over 24 weeks and comprised four sequential modules, each based on a clinical scenario that demonstrated a typical, acute mental health presentation to a general hospital ED. The course was designed to model collaborative practice in mental health emergency care. RESULTS: Participants were surveyed before and after completing the MHEC course. Statistically significant improvements were detected in participant confidence in managing key mental health problems, perceived self-efficacy in dealing with challenging, aggressive behaviours and confidence in key online learning skills. Participants also reported very positive experiences in relation to the course content and structure, instructor support, multidisciplinary discussion and feedback, and improvements in their knowledge and skills about emergency mental healthcare. CONCLUSIONS: This study provides evidence for the effectiveness and acceptability of an online educational program in developing the capacity of front-line staff to respond effectively to people who present to EDs with acute mental health problems. The positive outcomes and evaluations of the MHEC course provide support for the deployment of online learning programs that address mental health emergency care.
Subject(s)
Computer-Assisted Instruction , Education, Distance/methods , Emergency Medical Services/organization & administration , Mental Health Services/organization & administration , Outcome Assessment, Health Care , Program Evaluation , Rural Health Services/organization & administration , Adult , Clinical Competence , Cooperative Behavior , Education, Distance/organization & administration , Educational Measurement , Educational Status , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Mental Health , Middle Aged , New South Wales , Online Systems , Patient Care Team , Qualitative Research , Statistics, Nonparametric , Surveys and Questionnaires , Young AdultABSTRACT
AIMS: To discuss the practical aspects of conducting research in a primary care setting, from the perspectives of the practitioner and the research team. METHODS: Various issues are discussed, including the relevance of research questions being generated in this setting, the advantages to both parties and the processes involved in conducting a study in specialist practice. This paper describes two recent studies (a randomized clinical trial and a qualitative study) conducted within specialist practice, to illustrate some of the potential difficulties. CONCLUSIONS: The success of conducting a study in primary care is determined by a variety of factors, including an interested specialist practitioner, motivated staff in a well-organized practice and the close support of an academic-based research team.
Subject(s)
Dental Research , Orthodontics, Corrective , Primary Health Care , Communication , Confidentiality , Dental Staff/education , Ethics, Dental , General Practice, Dental , Humans , Informed Consent , Interprofessional Relations , Orthodontics, Corrective/ethics , Patient Selection , Pilot Projects , Publishing , Randomized Controlled Trials as Topic , Research Design , Research Support as Topic , Treatment OutcomeABSTRACT
A resequencing approach was adopted to identify sequence variants in the PRNP gene that may affect susceptibility or resistance to bovine spongiform encephalopathy. The entire PRNP gene (>21 kb) was sequenced from 26 chromosomes from a group of Holstein-Friesian cows, as well as exon 3 of PRNP (>4 kb) from a further 24 chromosomes from six diverse breeds. We identified 51 variant sequences of which 42 were single nucleotide polymorphisms and nine were insertion/deletion (indel) events. The study was extended to exon 3 of the sheep PRNP gene where 23 sequence variants were observed, four of which were indels. The level of nucleotide diversity in the complete bovine PRNP gene was pi = 0.00079, which is similar to that found at the bovine T-cell receptor alpha delta joining region (pi = 0.00077), but somewhat less than that observed for the bovine leptin (pi = 0.00265). Sequence variation within exon 3 of PRNP in both cattle (pi = 0.00102) and sheep (pi = 0.00171) was greater than that for the complete PRNP gene, with sheep showing greater sequence variation in exon 3 than cattle. The level of sequence variation reported here is greater than previously thought for the bovine PRNP gene in cattle. This study highlights the contribution that recombination plays in increasing allelic diversity in this species.
Subject(s)
Amyloid/genetics , Cattle/genetics , Genetic Variation , Protein Precursors/genetics , Sheep/genetics , Animals , Chromosome Mapping , DNA Primers , Encephalopathy, Bovine Spongiform/genetics , Genotype , Prions , Sequence Analysis, DNAABSTRACT
UNLABELLED: Auxiliary shocks (AS) from electrodes sutured to the left ventricle (LV) prior to primary biphasic shocks (PS) have been shown to reduce defibrillation thresholds (DFT). Two capacitors are required to generate these waveforms. We investigate delivery of AS from one capacitor using a novel waveform. The epicardial surface of the LV is accessed transvenously via the middle cardiac vein (MCV) avoiding a thoracotomy. METHODS: A defibrillation electrode was placed in the right ventricle (RV) and superior vena cava (SVC) in 12 pigs (37+/-2 kg). A 50x1.8 mm electrode was inserted in the MCV through a guide catheter. A can was placed in the left pectoral region. A monophasic AS (100 microF, 1.5 J) was delivered along one pathway before switching to deliver a biphasic waveform (40% tilt, 2 ms phase 2) along another. DFTs (PS+AS) were assessed using a binary search. Two configurations not incorporating AS acted as controls. DFTs were compared using repeated measures analysis of variance. RESULTS: DFTs of the four novel configurations (AS/PS) were: RV-->Can/MCV-->Can=14.9+/-3.7 J, MCV-->Can/RV-->Can=17.2+/-5.7 J, RV-->SVC+Can/MCV-->SVC+Can=13.4+/-4.6 J, MCV-->SVC+Can/RV-->SVC+Can=17.1+/-5.9 J. Delivering AS in the RV followed by PS in the MCV reduced the DFT (RV-->Can (19.9+/-7.3 J, P<0.01) and RV-->SVC+Can (19.2+/-6.0 J, P<0.05)). CONCLUSIONS: Delivering AS prior to PS in the MCV reduces the DFT by up to a third compared to conventional configurations of RV-->Can and RV-->SVC+Can. This is possible using only a single capacitor and an entirely transvenous approach to the LV.
Subject(s)
Coronary Vessels/physiology , Coronary Vessels/surgery , Defibrillators, Implantable , Electric Countershock/instrumentation , Sensory Thresholds/physiology , Animals , Electric Impedance , Electrodes, Implanted , Electrophysiologic Techniques, Cardiac/instrumentation , Equipment Design , Heart Ventricles/surgery , Models, Animal , Models, Cardiovascular , Swine , Ventricular FunctionABSTRACT
The doppel protein (Dpl) is a prion-like protein encoded by the gene PRND, which has been found downstream of the prion gene, PRNP, in human and mouse. This paper describes the isolation and structural organization of the bovine and ovine PRND genes, which are composed of two exons compared with the three of human and mouse. Intergenic distances between PRNP and PRND were covered by means of long-range PCR and found to be 16.8 and 20 kb, in cattle and sheep respectively. The 5' and 3' untranslated regions (UTR) were analyzed to identify transcription regulatory sequences and compared with those from the PRND and PRNP sequences published for other species. Three polymorphisms (R50H, N110H, and R132Q) were revealed in the cattle coding region; two synonymous substitutions (I12I, A26A) were found in sheep. None of the polymorphisms was significantly associated with either Bovine Spongiform Encephalopathy (BSE) in cattle or scrapie in sheep.
Subject(s)
Cattle/genetics , Polymorphism, Genetic/genetics , Prions/genetics , Sheep/genetics , Animals , DNA Primers/chemistry , Exons , GPI-Linked Proteins , Genotype , In Situ Hybridization, Fluorescence , Introns , Polymerase Chain Reaction , Prions/chemistry , Promoter Regions, Genetic , Sequence Analysis, DNASubject(s)
Amyloid/genetics , Cattle/genetics , Polymorphism, Genetic , Promoter Regions, Genetic/genetics , Protein Precursors/genetics , Animals , Base Sequence , DNA/chemistry , DNA/genetics , Gene Library , Molecular Sequence Data , Polymerase Chain Reaction/veterinary , Prions , Sequence Alignment , Sequence Analysis, DNAABSTRACT
Nonthoracotomy leads (NTLs) with an iridium oxide (IROX) coating exhibit lower defibrillation thresholds (DFTs) than uncoated NTLs. We tested whether adding an IROX coating to an active pectoral can would influence defibrillation efficacy. However, the primary purpose of this study was to examine the impedance changes that occur at different voltages for uncoated titanium NTLs and identical NTLs with an IROX coating. We studied anesthetized pigs with an NTL placed in the right ventricle and coupled this to an active pectoral can. Biphasic waveform DFTs were obtained for the four NTLs and can combinations: uncoated NTL and uncoated can, uncoated NTL and IROX can, IROX NTL and uncoated can, and IROX NTL and IROX can. The respective energy DFTs were: 23.6 +/- 6.9, 24.1 +/- 6.7, 21.3 +/- 6.0, and 21.4 +/- 7.0 J. The IROX NTL DFTs were significantly lower (P < 0.05) than the uncoated NTL DFTs (either can), confirming our previous study. We then used a low tilt monophasic waveform to assess impedance changes. The impedance rise for each NTL/can combination was measured at 50, 100, 300, and 700 V. Comparisons of impedance changes between voltage levels showed that the impedance rise was inversely related to voltage and was greatest with uncoated NTLs. The IROX coating of the NTL reduced the impedance rise at all shock voltages, but was particularly beneficial at the lower voltages. No advantage was seen when the pectoral can was coated with IROX regardless of which NTL was used. Our results suggest that low voltage applications, such as atrial defibrillation, would benefit most from the IROX-coated NTL, and further studies are warranted in this area.
Subject(s)
Coated Materials, Biocompatible , Defibrillators, Implantable , Electrocardiography , Iridium , Titanium , Animals , Electrodes, Implanted , Endocardium , SwineABSTRACT
Standard orthodontic facebows may accidentally detach from the appliance buccal tubes at night; this could reduce the effectiveness of extra oral traction and occasionally cause an injury. To try and prevent facebow detachment at night a facebow with a locking mechanism was introduced. This study assessed the ability of 706 consecutively treated patients to learn to wear and use this facebow. The facebows were fitted in 9 different practices supervised by 12 orthodontists. Data from the patients and orthodontists were collected over a 2-year period and covered approximately 166,550 nights. All the orthodontists were able to fit and adjust the facebow; a total of 697 patients successfully used the facebow. Accidental detachment of the facebow at night was reported to be less than 1%. This indicates a significant improvement in the safety of the facebow and should help to improve compliance by increasing the number of hours of wear achieved by the patients.
Subject(s)
Extraoral Traction Appliances , Orthodontic Appliance Design , Accident Prevention , Adolescent , Adult , Child , Equipment Failure , Evaluation Studies as Topic , Extraoral Traction Appliances/adverse effects , Extraoral Traction Appliances/classification , Female , Follow-Up Studies , Humans , Male , Orthodontic Appliances, Functional , Orthodontic Appliances, Removable , Patient Compliance , Safety , Surface PropertiesABSTRACT
EGFRvIII is a ligand-independent, constitutively active variant of the epidermal growth factor receptor (EGFR) that is specifically expressed in gliomas and various other human malignancies and has been proposed as a target for directed tumor therapy. We have recently constructed a highly potent single-chain antibody-toxin, scFv(14E1)-ETA, which consists of the variable domains of the antibody 14E1 specific for human full-length EGFR genetically fused to a truncated form of Pseudomonas exotoxin A. We demonstrate here binding of 14E1 antibody to both full-length and variant EGFR. In contrast to a recombinant toxin containing transforming growth factor-alpha (TGF-alpha) as a cell targeting domain, scFv(14E1)-ETA was highly active on cells expressing EGFRvIII. Surprisingly, scFv(14E1)-ETA displayed cell killing activity on EGFRvIII-expressing cells that was up to 100-fold higher than on control cells expressing full-length EGFR. No differences in the binding affinities of scFv(14E1)-ETA to full-length EGFR or EGFRvIII were observed, suggesting that events downstream of immunotoxin binding are responsible for the increased sensitivity of EGFRvIII-expressing cells. This might have implications for the development of therapeutic reagents simultaneously targeting different forms of the EGFR.
Subject(s)
Antibodies, Monoclonal/immunology , ErbB Receptors/immunology , Immunotoxins/toxicity , 3T3 Cells , Animals , Antibodies, Monoclonal/chemistry , Antibody Specificity , Cell Survival , Humans , Mice , Recombinant Proteins , TransfectionABSTRACT
OBJECTIVE: To determine the efficacy and cost of a simplified superovulation regimen compared with traditional control ovarian hyperstimulation with gonadotropins (HMG). STUDY DESIGN: This was a retrospective study in a university referral center with 99 infertile couples undergoing 225 treatment cycles. The outcome was compared to outcomes of previously published studies. The simplified superovulation regimen included clomiphene citrate 100 mg on cycle days 5 through 9 and HMG 75 IU on cycle days 5, 7, 9, and 11, with estradiol and ultrasound monitoring on day 13. If adequate follicular maturity was documented, HCG 10,000 IU was administered, followed by intrauterine insemination 40 hours later. RESULTS: Fecundity rates were assessed by life table analysis. Average cycle fecundity was 8%, with a cumulative rate of 29% over 4 cycles, compared to 10% monthly fecundity with HMG/IUI and background rates of 1 to 3%. Costs averaged $662 per cycle compared to $1,854 with HMG/IUI. CONCLUSION: A simplified protocol of CC/HMG/ IUI is almost as effective as HMG/IUI and costs only one-third as much.
Subject(s)
Infertility/drug therapy , Insemination, Artificial/economics , Superovulation , Adult , Clinical Protocols , Clomiphene/therapeutic use , Cost-Benefit Analysis , Female , Fertility , Fertility Agents, Female/therapeutic use , Humans , Infertility/etiology , Insemination, Artificial/methods , Male , Menotropins/therapeutic use , Pregnancy , Pregnancy Rate , Retrospective StudiesABSTRACT
The polarity of a monophasic and biphasic shocks have been reported to influence DFTs in some studies. The purpose of this study was to evaluate the effect of the first phase polarity on the DFT of a biphasic shock utilizing a nonthoracotomy "hot can" electrode configuration which had a 90-microF capacitance. We tested the hypothesis that anodal first phase was more effective than cathodal ones for defibrillation using biphasic shocks in ten anesthetized pigs weighing 38.9 +/- 3.9 kg. The lead system consisted of a right ventricular catheter electrode with a surface area of 2.7 cm2 and a left pectoral "hot can" electrode with 92.9 cm2 surface area. DFT was determined using a repeated "down-up" technique. A shock was tested 10 seconds after initiation of ventricular fibrillation. The mean delivered energy at DFT was 11.2 +/- 1.7 J when using the right ventricular apex electrode as the cathode and 11.3 +/- 1.2 J (P = NS) when using it as the anode. The peak voltage at DFT was also not significantly different (529.0 +/- 41.3 and 531.8 +/- 28.6 V, respectively). We concluded that the first phase polarity of a biphasic shock used with a nonthroracotomy "hot can" electrode configuration did not affect DFT.
Subject(s)
Electric Countershock , Electrodes , Ventricular Fibrillation/therapy , Animals , Cardiac Catheterization , Disease Models, Animal , Electric Countershock/instrumentation , Electric Countershock/methods , Electrocardiography , Swine , Treatment Outcome , Ventricular Fibrillation/physiopathologyABSTRACT
1. The CCKB/gastrin receptors mediating pentagastrin stimulation of gastric acid secretion by histamine release and by direct stimulation of oxyntic cells have been characterized in the immature rat isolated stomach assay. This was achieved by estimating antagonist affinity values for competitive antagonists from three distinct chemical classes (L-365,260, PD134,308 and JB93190) in the absence and presence of a high concentration of the histamine H2-receptor antagonist, famotidine (30 microM). 2. Pentagastrin produced concentration-dependent stimulation of gastric acid secretion in the absence and presence of famotidine. Famotidine depressed the maximum secretory response to pentagastrin although the degree of depression varied between experimental replicates (25-60%). This variation was attributed to the histamine-release mediated component of acid secretion, as judged by the consistency of the maximum responses obtained in the presence, but not absence, of famotidine. 3. All three CCKB/gastrin receptor antagonists behaved as surmountable antagonists in the absence and presence of famotidine. JB93190 (pKB approximately 9.1, approximately 8.9, in the absence and presence of famotidine, respectively) was approximately 30 fold more potent than either L-365,260 (pKB approximately 7.4, approximately 7.1) or PD134,308 (pKB approximately 7.6, approximately 7.4). 4. It was assumed that the famotidine treatment converted pentagastrin-stimulated acid secretion from a combination of an indirect action due to the release of histamine and a direct action on the oxyntic cell to solely a direct action on the oxyntic cell. A simple mathematical model of this two-receptor system was developed. The direct and indirect components were assumed to sum to produce the total response to pentagastrin obtained in the absence of famotidine. It was found that this model could account quantitatively for the behaviour of the three antagonists without invoking a difference in antagonist affinity for the CCKB/gastrin receptors mediating the direct and indirect actions of pentagastrin. However, a conclusion of receptor homogeneity has to be qualified because the model was also used to generate simulations which indicated that the analysis could only detect antagonist affinity differences of greater than one log-unit between enterochromaffin-like (ECL) and oxyntic cell CCKB/gastrin receptor populations.
Subject(s)
Gastric Acid/metabolism , Gastric Mucosa/metabolism , Histamine/pharmacology , Pentagastrin/pharmacology , Receptors, Cholecystokinin/drug effects , Animals , Binding, Competitive/drug effects , Enterochromaffin Cells/drug effects , Enterochromaffin Cells/metabolism , Famotidine/pharmacology , Gastric Mucosa/drug effects , Histamine H2 Antagonists/pharmacology , In Vitro Techniques , Kinetics , Models, Biological , Rats , Rats, Wistar , Receptors, Cholecystokinin/antagonists & inhibitors , Stimulation, ChemicalABSTRACT
BACKGROUND: Multiple factors contribute to an improved defibrillation threshold of biphasic shocks. The leading-edge voltage of the second phase may be an important factor in reducing the defibrillation threshold. METHODS AND RESULTS: We tested two experimental biphasic waveforms with large voltage changes at phase reversal. The phase 2 leading-edge voltage was twice the phase 1 trailing-edge voltage. This large voltage change was achieved by switching two capacitors from parallel to series mode at phase reversal. Two capacitors were tested (60/15 microfarads [microF] and 90/22.5 microF) and compared with two control biphasic waveforms for which the phase 1 trailing-edge voltage equaled the phase 2 leading-edge voltage. The control waveforms were incorporated into clinical (135/135 microF) or investigational devices (90/90 microF). Defibrillation threshold parameters were evaluated in eight anesthetized pigs by use of a nonthoracotomy transvenous lead to a can electrode system. The stored energy at the defibrillation threshold (ion joules) was 8.2 +/- 1.5 for 60/15 microF (P < .01 versus 135/135 microF and 90/90 microF), 8.8 +/- 2.4 for 90/22.5 microF (P < .01 versus 135/135 microF and 90/90 microF), 12.5 +/- 3.4 for 135/135 microF, and 12.6 +/- 2.6 for 90/90 microF. CONCLUSIONS: The biphasic waveform with large voltage changes at phase reversal caused by parallel-series mode switching appeared to improve the ventricular defibrillation threshold in a pig model compared with a currently available biphasic waveform. The 60/15-microF capacitor performed as well as the 90/ 22.5-microF capacitor in the experimental waveform. Thus, smaller capacitors may allow reduction in device size without sacrificing defibrillation threshold energy requirements.
Subject(s)
Electric Countershock/methods , Animals , Differential Threshold , Electricity , Equipment Design , Swine , Ventricular FunctionABSTRACT
A truncated epidermal growth factor receptor (EGFR) expressed from a rearranged and amplified EGFR gene is present at high frequency in gliomas. In this work we show that when this receptor is expressed in NIH3T3 fibroblasts it is partially activated and confers tumorigenicity to this cell line in vivo but no growth advantage in in vitro anchorage-independent growth assays. Because the mutation occurs in the extracellular domain of the receptor, it can be considered to represent a glioma-specific tumour marker. Here we demonstrate that 2 monoclonal antibodies, DH1.1 and DH8.3, raised to a synthetic peptide spanning the unique junctional sequence, can recognise the mutant receptor but not the normal receptor in both denatured and native states. Furthermore, radiolabelled antibody DH8.3 successfully targets tumours expressing this antigen in nude mice.
Subject(s)
Antibodies, Monoclonal/metabolism , ErbB Receptors/metabolism , Glioblastoma/metabolism , Mutation , 3T3 Cells/metabolism , Amino Acid Sequence , Animals , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/pharmacokinetics , Antibody Specificity , Base Sequence , Cell Transformation, Neoplastic , Epitopes/immunology , Epitopes/metabolism , ErbB Receptors/genetics , ErbB Receptors/immunology , Glioblastoma/ultrastructure , Humans , Mice , Mice, Nude , Molecular Sequence Data , Neoplasm Transplantation , Phosphorylation , Rabbits , TransfectionABSTRACT
1. The cardiovascular actions of cholecystokinin and related peptides were investigated in the pithed rat. The receptors and the mechanisms involved in these experiments were characterized. 2. Sulphated cholecystokinin octapeptide (sCCK-8, 0.1-100 nmol kg-1, i.v.) elicited a dose-dependent bradycardia and increase in mean arterial blood pressure. Neither gastrin-17 nor pentagastrin had any effect at concentrations up to 100 nmol kg-1. 3. Both the pressor response and bradycardia elicited by sCCK-8 were reduced by the selective CCKA receptor antagonists, devazepide (0.5-50 nmol kg-1) and lorglumide (1-7 mumol kg-1). The selective CCKB receptor antagonists, CI-988 (1 mumol kg-1) and L-365,260 (15 mumol kg-1) did not inhibit the effects of sCCK-8. 4. The pressor response induced with sCCK-8 was reduced by treatment with either phentolamine (3 mumol kg-1) or guanethidine (2 mumol kg-1) and was unaffected by treatment with propranolol, atropine or hexamethonium. The pressor response also persisted following bilateral adrenalectomy. 5. The bradycardia induced with sCCK-8 was unaffected by treatment with phentolamine, propranolol, guanethidine, atropine, hexamethonium or bilateral adrenalectomy. 6. The tetrapeptide of cholecystokinin (CCK-4) elicited a dose-dependent pressor response but did not induce bradycardia. The pressor response was unaffected by devazepide (50 nmol kg-1), L-365260 (15 mumol kg-1) or phentolamine (3 mumol kg-1). 7. In the pithed rat, sCCK-8 acted via CCKA receptors to increase arterial blood pressure indirectly, at least in part, through activation of alpha-adrenoceptors. The observed bradycardia was also mediated byCCKA receptors but possibly through a direct action on the heart.
Subject(s)
Cholecystokinin/toxicity , Receptors, Cholecystokinin/drug effects , Sincalide/toxicity , Adrenalectomy , Adrenergic Agents/administration & dosage , Adrenergic Agents/pharmacology , Adrenergic Agents/therapeutic use , Animals , Benzodiazepinones/administration & dosage , Benzodiazepinones/pharmacology , Benzodiazepinones/therapeutic use , Blood Pressure/drug effects , Bradycardia/chemically induced , Decerebrate State , Devazepide , Dose-Response Relationship, Drug , Gastrins/administration & dosage , Gastrins/toxicity , Guanethidine/administration & dosage , Guanethidine/pharmacology , Guanethidine/therapeutic use , Heart Rate/drug effects , Hormone Antagonists/administration & dosage , Hormone Antagonists/pharmacology , Hormone Antagonists/therapeutic use , Hormones/administration & dosage , Hormones/toxicity , Hypertension/chemically induced , Indoles/administration & dosage , Indoles/pharmacology , Indoles/therapeutic use , Male , Meglumine/administration & dosage , Meglumine/analogs & derivatives , Meglumine/pharmacology , Meglumine/therapeutic use , Pentagastrin/administration & dosage , Pentagastrin/pharmacology , Phentolamine/administration & dosage , Phentolamine/pharmacology , Phentolamine/therapeutic use , Proglumide/administration & dosage , Proglumide/analogs & derivatives , Proglumide/pharmacology , Proglumide/therapeutic use , Rats , Receptors, Cholecystokinin/metabolism , Tetragastrin/administration & dosage , Tetragastrin/toxicityABSTRACT
Synthetic genes encoding the 146 and 155 amino acid forms of human basic fibroblast growth factor (bFGF) were constructed with codon usage biased towards the polyhedrin-encoding gene of Autographa californica nuclear polyhedrosis virus (AcNPV). Expression of both bFGF genes in Spodoptera frugiperda (SF-21) suspension cell culture using a recombinant baculovirus yielded approximately 2.5 mg of mitogenically fully active protein per 10(9) cells following heparin-affinity chromatography. To improve translational efficiency, the Kozak consensus sequence was introduced and it was found that neither the replacement of a pyrimidine by a purine at position -3, nor the nature of the base at position +4 had any noticeable effect on the final levels of bFGF expression in SF-21 cells. The bases at these critical points in the consensus do not therefore play a major role in expression levels of the bFGF synthetic genes. The two synthetic genes were also expressed in Escherichia coli as native proteins using the T7 expression system. 5 mg of mitogenically fully active bFGF were obtained from 1 l of bacterial culture. Both insect cell- and E. coli-derived bFGF were equally mitogenic for Swiss 3T3 fibroblasts.
Subject(s)
Consensus Sequence , Fibroblast Growth Factor 2/genetics , Genes, Synthetic , Nucleopolyhedroviruses/genetics , 3T3 Cells , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , DNA, Recombinant , Escherichia coli/genetics , Fibroblast Growth Factor 2/physiology , Genetic Vectors , Humans , Mice , Mitogens/genetics , Mitogens/physiology , Molecular Sequence Data , Recombination, Genetic , Sequence Homology, Amino Acid , SpodopteraABSTRACT
An In vitro comparison of the corrosion response of 316LVM stainless steel and MP35N (a CoNiCrMo alloy) electrodes under conditions appropriate to applications in functional electrical stimulation (FES) was made. Electrodes of both alloys were subjected to a cathodic 40 microC/cm2 charge injection protocol and the potential transient response was recorded over a 96 h period. The transient responses were compared with potentiodynamic polarization data used to establish the quasiequilibrium response of the alloys in the carbonate and phosphate-buffered saline electrolyte used in the study. The MP35N electrodes exhibited extensive pitting corrosion during charge injection, whereas little corrosion was observed on 316LVM electrodes. An explanation for the susceptibility of MP35N to corrosion during charge injection is found in the potentiodynamic polarization data, which reveal a breakdown potential (critical pitting potential) of 0.45 V (SCE) for MP35N compared with 1.05 V (SCE) for 316LVM. Factors that may influence corrosion response during charge injection from alloys exhibiting active-passive behavior are discussed.