Biomedical subjects

Colin Harwood

Publications and source records attributed to Colin Harwood.

5 recordsLinked to original sources

PubMed2006

Effectiveness of intermediate-fidelity simulation training technology in undergraduate nursing education.

AIM: The aim of this paper is to present the results of a study designed to determine the effect of scenario-based simulation training on nursing students' clinical skills and competence. BACKGROUND: Using full-scale, realistic, medical simulation for training healthcare professionals is becoming more and more common. Access to this technology is easier than ever before with the opening of several simulation centres throughout the world and the availability on the market of more sophisticated and affordable patient simulators. However, there is little scientific evidence proving that such technology is better than more traditional techniques in the education of, for example, undergraduate nursing students. METHODS: A pretest/post-test design was employed with volunteer undergraduate students (n = 99) from second year Diploma of Higher Education in Nursing programme in United Kingdom using a 15-station Objective Structured Clinical Examination. Students were randomly allocated to either a control or an experimental group. The experimental group, as well as following their normal curriculum, were exposed to simulation training. Subsequently, all students were re-tested and completed a questionnaire. The data were collected between 2001 and 2003. RESULTS: The control and experimental groups improved their performance on the second Objective Structured Clinical Examination. Mean test scores, respectively, increased by 7.18 and 14.18 percentage points. The difference between the means was statistically significant (P < 0.001). However, students' perceptions of stress and confidence, measured on a 5-point Likert scale, was very similar between groups at 2.9 (1, not stressful; 5, very stressful) and 3.5 (1, very confident; 5, not confident) for the control group, and 3.0 and 3.4 for the experimental group. CONCLUSIONS: Intermediate-fidelity simulation is a useful training technique. It enables small groups of students to practise in a safe and controlled environment how to react adequately in a critical patient care situation. This type of training is very valuable to equip students with a minimum of technical and non-technical skills before they use them in practice settings.

Adult↗

PubMed2005

12-lead ECG training: the way forward.

The teaching of electrocardiography (ECG) monitoring has not changed for decades and still very much relies on access to real patients for practice. However there is nowadays an even greater need for modern training tools in this field as more healthcare professionals than ever before need to be trained on 12-lead ECG monitoring techniques. For example in many parts of the UK ambulance paramedics use features observed from 12-lead ECG monitoring equipment to determine whether or not a patient can receive pre-hospital thrombolytic therapy. Because important decisions are made without the presence of a cardiologist, it is essential that the training is carried out with the most realistic tools, including tools which give realistic feedback of the consequences of incorrect electrode placement. Current mannequins for ECG training are designed with protruding electrodes on the chest, which act as cues for trainees. There is therefore a need for a realistic simulation training tool to teach 12-lead ECG interpretation which includes the ability to give this feedback. We are currently working on the development of such a training tool and it is expected that it will be of great interest to medical, nursing and paramedic schools.

Clinical Competence↗

PubMed2003

Fed-batch production of recombinant beta-galactosidase using the universal stress promoters uspA and uspB in high cell density cultivations.

A high-level production system using the universal stress promoters uspA and uspB in a fed-batch cultivation based on minimal medium was designed. In development it was shown that a standard industrial fed-batch protocol could not be used for this purpose since it failed to induce the levels of product as compared to the basal level. Instead, a batch protocol followed by a low constant feed of glucose was shown to give full induction. The levels of the product protein, beta-galactosidase, corresponded to approximately 25% of the total protein. Higher levels were found using the uspA than uspB vectors where uspA showed considerably higher basal level. The data indicate that the sigma(70) regulated promoter, uspA, although affected by the alarmone guanosine tetraphosphate, ppGpp, worked partly in a similar manner to constitutive promoters. An industrial high cell density fed-batch cultivation on the basis of the suggested fed-batch protocol and the uspA promoter gave a final beta-galatosidase concentration of 7 g/L and a final cell concentration of 65 g/L. The heterogeneity in production of the individual cell was measured by fluorescence microscopy. The data show that there is a process time independent heterogeneity in production, which is suggested to be caused by heterogeneity in the substrate uptake rate of the individual cell.

Bacterial Proteins↗

PubMed2003

Limiting factors in Escherichia coli fed-batch production of recombinant proteins.

Fed-batch production of recombinant beta-galactosidase in E. coli was studied with respect to the specific growth rate at induction. The cultivations were designed to induce protein production by IPTG at a glucose feed rate corresponding to high mu = 0.5 h(-1)) or low (mu = 0.1 h(-1)) specific growth rate. Protein production rate was approximately 100% higher at the higher specific growth rate, resulting in the accumulation of beta-galactosidase up to 30% of the total cell protein. Transcription analysis showed that beta-galactosidase-specific messenger RNA was immediately formed after induction (<5 min), but the amount was the same in both cases and was thus not the initial limiting factor. The content of ribosomes, as represented by rRNA, rapidly decreased with specific growth rate from a relative level of 100%, at the high specific growth rate, to 20% at the low specific growth rate. At high specific growth rate, ribosomes were additionally degraded upon induction due to the high production level. Translation therefore seemed to be the initial limiting factor of the protein synthesis capacity. The alarmone guanosine tetraphosphate increased at both high and low feed level inductions, indicating an induction-forced starvation of charged tRNA and/or glucose. The altered physiological status was also detected by the formation of acetic acid. However, the higher production rate resulted in high-level accumulation of acetic acid, which was absent at low feed rate production. Acetic acid production is thus coupled to the high product formation rate and is proposed to be due either to a precursor drain of Krebs cycle intermediates and a time lag before induction of the glyoxalate shunt, or to single amino acid overflow, since the model product is relatively poor in glycin and alanin. In conclusion, it is proposed that production at high specific growth rate becomes precursor-limited, while production at low specific growth rate is carbon- and/or energy-limited.

Acetic Acid↗

PubMed2000

Cell-associated degradation affects the yield of secreted engineered and heterologous proteins in the Bacillus subtilis expression system.

A series of chimeric alpha-amylase genes derived from amyL, which encodes the liquefying alpha-amylase from Bacillus licheniformis, were constructed in vitro using gene splicing techniques. The gene constructs were cloned in Bacillus subtilis, where their ability to direct the synthesis and secretion of active alpha-amylase was determined. Detectable alpha-amylase activity was observed for some, but not all, of the chimeric proteins. Studies on the secretion of wild-type AmyL and its chimeric derivatives revealed that, whilst these proteins were stable in the extracellular milieu, all were subject to some degree of degradation during secretion. The chimeric enzymes were degraded to a greater extent than the native enzyme. These findings suggest that cell-associated proteolysis is a significant problem affecting the use of B. subtilis as host bacterium for the production of heterologous proteins.

Bacillus subtilis↗