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Biomedical subjects

N Robinson

Publications and source records attributed to N Robinson.

At least 37 records · Page 2Linked to original sources

Optimized production of high-titer recombinant adeno-associated virus in roller bottles.

Adeno-associated viral (AAV) vectors are used for in vivo gene transfer in a number of preclinical models of genetic diseases (including large-animal models) and are currently being tested in clinical trials for treatment of hemophilia B and cystic fibrosis. Protocols for production of AAV vectors in a helper virus-free system are available and are based on transient transfection of HEK-293 cells with multiple plasmids. Scale-up of vector production has been labor intensive and inefficient because of a lack of larger culture vessels suitable for growth of adherent cells, large-scale transfection, and vector production. Here we report efficient production of AAV vector in roller bottles, which represents a 10-fold scale-up from the conventional flask or plate method. Optimized production yielded greater than 10(13) vector genomes per bottle and was as cost effective as published protocols using plates. Successful vector production by this method was dependent on optimization of transfection by calcium phosphate precipitation, of monitoring of cell growth (by measurement of glucose consumption), of cell culture conditions, and CO2/air exchange with the culture vessel.

Cell Count↗

The scope of guidelines to prevent healthcare-associated infections.

As care is increasingly delivered in the community rather than acute settings, there has been concern that this might be accompanied by a rise in healthcare-associated infection. Consequently, the National Institute for Clinical Excellence (NICE) has commissioned a set of infection prevention guidelines for healthcare workers in community and primary care. The guideline developers were anxious to concentrate this guidance on the areas of most concern to practitioners, particularly in relation to devices. This article describes how a survey and focus groups were employed to identify the areas for guideline development, namely standard principles, long-term indwelling urinary catheters, enteral feeds and central intravascular devices.

Community Health Services↗

Detection of nandrolone metabolites in urine after a football game in professional and amateur players: a Bayesian comparison.

Nandrolone (19-nortestosterone) is a widely used anabolic steroid in sports where strength plays an essential role. Once nandrolone has been metabolised, two major metabolites are excreted in urine, 19-norandrosterone (NA) and 19-noretiocholanolone (NE). In 1997, in France, quite a few sportsmen had concentrations of 19-norandrosterone very close to the IOC cut off limit (2ng/ml). At that time, a debate took place about the capability of the human male body to produce by itself these metabolites without any intake of nandrolone or related compounds. The International Football Federation (FIFA) was very concerned with this problematic, especially because the World Cup was about to start in France. In this respect, a statistical study was held with all football players from the first and second divisions of the Swiss Football National League. All players gave a urine sample after effort and around 6% of them showed traces of 19-norandrosterone. These results were compared with amateur football players (control group) and around 6% of them had very small amounts of 19-norandrosterone and/or 19-noretiocholanolone in urine after effort, whereas none of them had detectable traces of one or the other metabolite before effort. The origin of these compounds in urine after a strenuous physical activity is still unknown, but three hypotheses can be put forward. First, an endogenous production of nandrolone metabolites takes place. Second, nandrolone metabolites are released from the fatty tissues after an intake of nandrolone, some related compounds or some contaminated nutritive supplements. Finally, the sportsmen may have taken something during or just before the football game.

Adult↗

Characterization of BALB/c mice B lymphocyte autoimmune responses to skin basement membrane component type XVII collagen, the target antigen of autoimmune skin disease bullous pemphigoid.

Bullous pemphigoid is an autoimmune blistering skin disease characterized by IgG autoantibodies targeting the skin basement membrane component type XVII collagen (BPAg2). To gain understanding of the disease's induction phase, we subcutaneously immunized adult BALB/c mice with peptides of human and/or the murine-equivalent BPAg2 pathogenic NC16A domain. Female mice were injected with peptides (human, murine, or combined human and murine), or PBS control emulsified in CFA, on a four-week interval. At the fourth and subsequent immunizations, all peptide-immunized mice were given murine peptides. Two weeks after the sixth immunization, ELISA detected IgG circulating autoantibodies against self peptides in 92% (47/51) of mice immunized with murine peptides; whereas none of the preimmune sera or the sera from PBS control-immunized mice reacted to the self peptides. In four mice their autoantibodies labeled mouse skin basement membrane. Breaking B-cell tolerance to BPAg2 sets the first step in dissecting the disease's induction phase.

Amino Acid Sequence↗

S100A7, S100A10, and S100A11 are transglutaminase substrates.

S100 proteins are a family of 10-14 kDa EF-hand-containing calcium binding proteins that function to transmit calcium-dependent cell regulatory signals. S100 proteins have no intrinsic enzyme activity but bind in a calcium-dependent manner to target proteins to modulate target protein function. Transglutaminases are enzymes that catalyze the formation of covalent epsilon-(gamma-glutamyl)lysine bonds between protein-bound glutamine and lysine residues. In the present study we show that transglutaminase-dependent covalent modification is a property shared by several S100 proteins and that both type I and type II transglutaminases can modify S100 proteins. We further show that the reactive regions are at the solvent-exposed amino- and carboxyl-terminal ends of the protein, regions that specify S100 protein function. We suggest that transglutaminase-dependent modification is a general mechanism designed to regulate S100 protein function.

3T3 Cells↗

Expression of interleukin-4 in the epidermis of transgenic mice results in a pruritic inflammatory skin disease: an experimental animal model to study atopic dermatitis.

Atopic dermatitis, a common, chronic, inflammatory skin disease that occurs with increasing prevalence, is characterized by hyperactivated cytokines of helper T cell subset 2 and is frequently associated with staphylococcal infection. An experimental animal model of atopic dermatitis induced by transgenically introduced cytokine is not available. We generated a transgenic mouse line expressing epidermal interleukin-4, a critical cytokine of helper T cell subset 2. Here we show that transgenic mice spontaneously developed a pruritic inflammatory skin disease reproducing all key features of human atopic dermatitis, including xerosis, conjunctivitis, inflammatory skin lesions, Staphylococcus aureus infection, histopathology of chronic dermatitis with T cell, mast cell, macrophage-like mononuclear cell, and eosinophil infiltration, and elevation of total serum IgE and IgG1. The onset and early progression of skin disease coincided with increased total serum IgE and IgG1. The mouse disease occurred at a 43% annual incidence rate and primarily affected the poorly haired skin: ear (100%), neck (65%), eye (53%), face (29%), tail (12%), leg (12%), and torso (6%). As a group the affected transgenic mice manifested with a skin disorder that fulfilled the clinical diagnostic criteria established for atopic dermatitis in human patients. Pending further characterization to authenticate it as a model of atopic dermatitis, this experimental animal model of pruritic inflammatory skin disease may facilitate investigations for the roles of interleukin-4 in cutaneous inflammation and skin infection in human patients.

Animals↗

Kaleidoscope: a 5-year action research project to develop nursing confidence in caring for patients with HIV disease in west India.

As the national epidemic of human immunodeficiency virus (HIV) infection and the acquired immune deficiency syndrome (AIDS) epidemic rapidly unfolds in India, nurses have to acquire new competencies in order to provide appropriate care to an increasing number of affected persons. In response, an Indo-British action research collaboration was initiated to build clinical confidence and facilitate relevant changes in nursing practice. During a 10-day educational programme, a change intervention was applied, culminating in the development of individual and partnership action plans focused on bringing about changes in nursing practice within well-defined fields of action. Following implementation of their action plans, participants were reassembled 12 months later for a follow-up workshop to discuss their progress and describe those factors that either helped or hindered them in achieving their objectives. They then developed new action plans for the next 12-month period. This article reports on the results from six cohorts (n = 160) in India who participated in this project between 1995 and 1999. Action plans were frequently focused on infection control, primary prevention, curriculum development in preregistration nursing programmes and in-service nursing education. The majority of participants reported significant achievements in realizing their action-plan objectives. Data analysis revealed that the change intervention itself, together with multidisciplinary support from colleagues, the senior status of the participant, and anticipating and attending the follow-up workshop, were all positively correlated with achievement. The lack of personal authority and resistance from managers were the two major factors negatively correlated with achievement. This method for facilitating changes in nursing practice has been successfully adapted and replicated by our group in other countries.

Acquired Immunodeficiency Syndrome↗

The epic project: developing national evidence-based guidelines for preventing healthcare associated infections. Phase I: Guidelines for preventing hospital-acquired infections. Department of Health (England).

In 1998, the Department of Health (England) commissioned the first phase of national evidence-based guidelines for preventing healthcare associated infections. These focused on developing a set of standard principles for preventing infections in hospitals together with guidelines for preventing hospital-acquired infections (HAI) associated with the use of short-term indwelling ureteral catheters in acute care and with central venous catheters in acute care. These guidelines are systematically developed broad statements (principles) of good practice that all practitioners can use and which can be incorporated into local protocols. A nurse-led, multi-professional team composed of infection prevention practitioners, clinical microbiologists/retrovirologist, epidemiologists, and researchers developed the guidelines. A rigorous guideline development process was used to inform the systematic reviews, the clinical and critical appraisal of relevant evidence, and linking that evidence to evolving guidelines. Both general and specialist clinical practitioners were involved in all stages of developing these guidelines, as were representatives from relevant Royal Colleges, learned societies, other professional organisations and key stakeholders. The introduction to these guidelines describes a robust and validated guideline development model that can be used by others to develop future guidelines. This model is described in more detail in the associated technical reports that can be found on the project web site http://www.epic.tvu.ac.uk. Locating and appropriately using good quality evidence to inform guideline development in this field is challenging. Evidence from rigorously conducted experimental studies was frequently limited and consequently a range of other types of evidence were systematically retrieved and carefully appraised. The concluding discussion on implementation highlights potential issues for clinical governance and areas for future research and suggests issues that need to be addressed to allow practitioners to successfully incorporate these guidelines into routine clinical practice.

Acute Disease↗

Safety of the new macrolide immunomodulators.

With the wide acceptance of cyclosporine in the treatment of skin disease, there has been an effort to find new immunomodulating agents with superior safety profiles for use in dermatology. Among the most promising of the classes are the new macrolide immunomodulators, including tacrolimus and pimecrolimus. Of these, only tocrolimus has had widespread use for nondermatologic indications, primarily solid organ transplantation. Both of these agents have been studied for inflammatory diseases of the skin. In this article, we review the systemic and topical toxicities of these macrolide immunomodulators.

Humans↗

Identification of a contaminating Mycobacterium tuberculosis strain with a transposition of an IS6110 insertion element resulting in an altered spoligotype.

Molecular fingerprinting with the IS6110 insertion sequence is useful for tracking transmission of Mycobacterium tuberculosis within a population or confirming specimen contamination in the laboratory or through instrumentation. Secondary typing with other molecular methods yields additional information as to the relatedness of strains with similar IS6110 fingerprints. Isolated, relatively rare, random events within the M. tuberculosis genome alter molecular fingerprinting patterns with any of the methods; therefore, strains which are different by two or more typing methods are usually not considered to be closely related. In this report, we describe two strains of M. tuberculosis, obtained from the same bronchoscope 2 days apart, that demonstrated unique molecular fingerprinting patterns by two different typing methods. They were closely linked through the bronchoscope by a traditional epidemiologic investigation. Genetic analysis of the two strains revealed that a single event, the transposition of an IS6110 insertion sequence in one of the strains, accounted for both the differences in the IS6110 pattern and the apparent deletion of a spacer in the spoligotype. This finding shows that a single event can change the molecular fingerprint of a strain in two different molecular typing systems, and thus, molecular typing cannot be the only means used to track transmission of this organism through a population. Traditional epidemiologic techniques are a necessary complement to molecular fingerprinting so that radical changes within the fingerprint pattern can be identified.

Bacterial Typing Techniques↗

An observational survey of emergency department rapid sequence intubation.

OBJECTIVES: To study the current practice of rapid sequence intubations (RSIs) in four different emergency medicine training programmes in the UK. METHODS: Observational study design involving four regional training programmes (Wessex, North West, Yorkshire, Avon). Data were collected in real time using a previously piloted survey tool. Data were collected by specialist registrars in emergency medicine over a continuous 28 day period. Data collected included: indications for RSI; key timings of RSI procedures; details of RSI practitioner; complications and outcome of procedure. RESULTS: Data from 60 RSIs were recorded and collected. The majority of decisions to perform RSIs were made by emergency physicians (74% cases). Over 50% of the RSIs occurred after 4 pm. Emergency physicians performed 26% of RSIs although the majority were performed by anaesthetists. Most of the given indications for RSIs were based on an assessment of airway protection. Hypoxia was an uncommon reason for RSI in this study (5%). In two thirds of cases the time taken from the decision being made to perform an RSI, to the achievement of successful intubation, was greater than 20 minutes. No failed intubations were recorded, although six other complications (all minor problems) were recorded. There was no significant difference in the response times between anaesthetists and emergency physicians. CONCLUSIONS: This study shows that emergency physicians are currently performing RSIs in emergency departments in the UK. It also suggests improvements could be made to patient care. In particular, standards of care should be agreed for the provision of RSI in the emergency department, including the personnel involved and the appropriate training of individuals. RSI activity in emergency departments in the UK should be audited nationally using an agreed audit tool.

Adolescent↗

In patients with head injury undergoing rapid sequence intubation, does pretreatment with intravenous lignocaine/lidocaine lead to an improved neurological outcome? A review of the literature.

It is well known that laryngeal instrumentation and endotracheal intubation is associated with a marked, transient rise in intracranial pressure (ICP). Patients with head injury requiring endotracheal intubation are considered particularly at risk from this transient rise in ICP as it reduces cerebral perfusion and thus may increase secondary brain injury. The favoured method for securing a definitive airway in this patient group is by rapid sequence intubation (RSI). In the United States the Emergency Airway Course teaches emergency physicians to routinely administer intravenous lidocaine as a pre treatment for RSI in this patient group in an attempt to attenuate this rise in ICP. A literature search was carried out to identify studies in which intravenous lidocaine was used as a pretreatment for RSI in major head injury. Any link to an improved neurological outcome was also sought. Papers identified were appraised in the manner recommended by the evidence based medicine group to ensure validity. There were no studies identified that answered our question directly and, furthermore, it is our belief that no such study, at present, exists in the literature. Six valid papers were found, which individually contained elements of the question posed and these are presented in a narrative and graphic form. There is currently no evidence to support the use of intravenous lidocaine as a pretreatment for RSI in patients with head injury and its use should only occur in clinical trials.

Anesthetics, Local↗

Coronary stent deployment in situs inversus.

Situs inversus with dextrocardia occurs in approximately one in 10 000 patients. Successful stent deployment for the treatment of unstable angina and situs inversus is presented. Three technical challenges associated with the procedure are highlighted. Firstly, the successful choice of diagnostic and interventional catheters is based on an understanding of the orientation of the aortic arch. With a right sided aorta Judkins catheters should be successful. Secondly, image reversal is not necessarily required for image interpretation. Thirdly, successful coronary engagement with catheters requires rotation in a direction opposite to that normally used.

Aged↗

Predictors of operative time in multicenter port-access valve registry: institutional differences in learning.

BACKGROUND: The predictors of operative time and the effects of learning in isolated valve operations using port-access techniques have not been defined. METHODS: Analysis of covariance was used to examine the determinants of procedure time, pump time, and aortic clamp time. In the largest prospective, registry of patients undergoing isolated aortic valve replacement (AVR, N=199), mitral repair (MVP, N=307), or mitral replacement (MVR, N=232) using port-access techniques 1997-1999 at 27 institutions. RESULTS: Institutional case volume ranged from one to 214 (median 6). Operative time was longer in redo procedures (5.3 +/- 1.6 vs. 4.4 +/- 1.3 hr, p = 0.0001), longer with MVP or MVR vs. AVR (4.8 +/- 1.2 vs. 5.0 +/- 1.5 vs. 3.8 +/- 1.2 hr, p = 0.0001), and decreased with case number (mean decrease 1.00 +/- 0.19 min/case, p = 0.04). Operative time also varied between institutions (p = 0.001). Rate of learning (decrease in time per case) varied significantly between institutions only for MVP (p = 0.03). Similar analysis showed that pump time and clamp times did not significantly change over time (p > 0.17) but varied significantly between institutions. Institutional volume did not affect operative, pump, or clamp times or rate of learning (decrease in operative time/case). CONCLUSIONS: These prospective registry data demonstrate that, for port-access valve procedures, procedure times continue to improve (learning) even after 100 cases. Procedure time and learning are affected by institutional differences and by the type of procedure, but are little affected by institutional volume. This data provides a model to understand learning of new surgical procedures, and this data suggests that port-access valve procedures can be mastered by a variety of institutions.

Analysis of Variance↗

Antimicrobial sensitivity of Haemophilus influenzae isolates from bacterial conjunctivitis.

Haemophilus influenzae is one of the common bacterial pathogens which affect children. Resistance to frequently used antibiotics is becoming a significant problem in community isolates of common pathogens. A retrospective review was conducted of the serotypes and antimicrobial sensitivity of H influenzae isolates from bacterial conjunctivitis, over an 18-month period. Data on antimicrobial sensitivity (obtained by the National Committee for Clinical Laboratory Standards disk diffusion method) and beta-lactamase production, and typing results, were analysed. Ninety-nine isolates were recovered, of which 87 were typed. Most isolates were recovered from children under one year of age. Ninety-three percent were unencapsulated and biotypes I and IV were most common. H influenzae type b was recovered only twice. beta-lactamase was produced by 41% isolates while four isolates were ampicillin-resistant but did not produce beta-lactamase. All isolates were sensitive to chloramphenicol and 45% were co-trimoxazole sensitive. H influenzae is commonly isolated from bacterial conjunctivitis in Barbados and, as elsewhere, the majority of isolates are from small children and are non-encapsulated. However, there is a high prevalence of beta-lactamase production, which may serve as a reservoir for transfer to more invasive encapsulated strains of H influenzae within the oropharyngeal flora.

Adult↗