The role of pre-operative assessment and ringfencing of services in the control of methicillin resistant Staphlococcus aureus infection in orthopaedic patients.

BACKGROUND: MRSA is a major economic and health issue internationally and as such is of particular importance in the appropriate management of orthopaedic patients. Bone, joint and implant infection can lead to unfavourable outcomes with a long protracted in hospital stay inevitable. The cost for the patient, the hospital and society are substantial. MATERIALS AND METHODS: This study was a review of a prospectively maintained database from our unit over three time points from 2005 to 2007. At each time point a new infection control measure was implemented in an effort to reduce MRSA infections. Total rates of MRSA infection and colonisation in all orthopaedic patients were recorded, before and after separation of trauma and elective services, and after the introduction of a screening pre assessment clinic. RESULTS: 12259 orthopaedic patients were reviewed over the three years. The mean age of MRSA infected patients was 71. A higher proportion of female patients were infected than male patients. The mean length of stay for infected patients was 23.4 days. The rate of infection dropped from 0.49% in 2005 to 0.24%in 2007. After the introduction of these measures there was a substantial reduction in organ space and deep tissue infections. CONCLUSION: The separation of emergency and elective orthopaedic services coupled with effective pre-operative screening has resulted in a significant reduction in MRSA infection despite an ever increasing prevalance.

Improving patient care--the first year in a dedicated surgical assessment unit.

A surgical assessment unit (SAU) was established in October 2009 at the Mid-Western Regional Hospital. We assessed this servic in its initial year and compared it to Emergency Department (ED) services. We audited SAU and ED databases and theatre logbooks from November 2009 to October 2010. 1949 patients were referred to the SAU and 857 patients were admitted (44%). Only 44 SAU patients (6%) waited more than 6 hours for a bed compared to 828 patients (68%) admitted through the ED. SAU patients who required emergency surgery had a shorter waiting time before theatre (37 (18.6%) vs 9(6%) waited less than 6 hours, p < 0.05). To summarise, we found that almost 2,000 patients who would otherwise have presented to the ED were referred to the SAU. Waiting times for admission and theatre were significantly shorter. Further resource allocation could expand the service and improve it further, by diverting more patients from the ED.

Cytoskeletal function in CD8- and T cell receptor-mediated interaction of cytotoxic T lymphocytes with class I protein.

Cloned allospecific cytolytic T lymphocytes (CTL) adhere to purified class I alloantigen immobilized on plastic and degranulate in response to it. Binding and degranulation are inhibited by drugs that impair cytoskeletal function. Cytochalasins D and E, which interfere with microfilament function, and colchicine, which disrupts microtubules, were used and gave qualitatively similar results. Concentrations of these drugs that inhibited degranulation in response to alloantigen did not inhibit response to immobilized anti-T cell receptor (TCR) antibody. Neither did they inhibit response when alloantigen was co-immobilized with an antibody against class I on the CTL to promote adhesion between the CTL and antigen-bearing surface. Thus, neither transmembrane signal generation via the TCR nor degranulation per se were prevented. Instead, the drugs act to prevent the initial adhesion to alloantigen. CTL binding to alloantigen depends in part on CD8-class I interaction, and adhesion via CD8 is "activated" by crosslinking the TCR with soluble anti-TCR antibody. This adhesion, too, is shown to be cytoskeleton dependent.

Contribution of lymphocyte function-associated-1/intercellular adhesion molecule-1 binding to the adhesion/signaling cascade of cytotoxic T lymphocyte activation.

A rapid induction of adhesion to immobilized intercellular adhesion molecule (ICAM)-1 occurs when cytotoxic T lymphocytes (CTL) are stimulated with either soluble anti-T cell receptor (TCR) monoclonal antibodies (mAb) or with immobilized alloantigen, and this binding is blocked by the addition of anti-lymphocyte function-associated (LFA)-1 mAbs. Requirements for activating LFA-1 adhesion to ICAM-1 are similar to those found for induction of binding to immobilized fibronectin (FN), but distinct from those for activating CD8-mediated adhesion to class I major histocompatibility complex. A distinct role for LFA-1 in co-signaling for TCR-dependent degranulation could not be demonstrated. In contrast, both CD8 and the FN-binding integrin provide costimulatory signals for this response. Thus, if co-signaling via LFA-1 occurs, it clearly differs from that provided by CD8 or the FN-binding integrin. On the basis of antibody blocking effects, alloantigen-dependent activation of adhesion to ICAM-1 involves both the TCR and CD8. These results support a view of CTL activation as a cascade of adhesion and signaling events, with different coreceptors making distinct contributions.

Activation of polyphosphoinositide hydrolysis in T cells by H-2 alloantigen but not MLS determinants.

Murine minor lymphocyte-stimulating (Mls) determinants are cell surface antigens that stimulate strong primary T cell responses; the responding T cells display restricted T cell receptor (TCR) V beta gene usage. Interaction of T cells with mitogens or major histocompatibility complex (MHC) antigens activated the polyphosphoinositide (PI) signaling pathway, but this pathway was not triggered by Mls recognition. However, interleukin-2 (IL-2) secretion and proliferation to all three stimuli were comparable. Thus, although recognition of both allo-H-2 and Mls determinants is thought to be mediated by the TCR, these antigens appear to elicit biochemically distinct signal transduction pathways.

Surgical site infection with methicillin-resistant Staphylococcus aureus after primary total hip replacement.

We have analysed the management and clinical outcome of a series of consecutive patients who had a total hip replacement and developed post-operative surgical site infection (SSI) with methicillin-resistant Staphylococcus aureus. The incidence of this infection was 1% over a period of five years. We studied SSI in 15 patients (16 infections) with a mean age of 72.7 years (53 to 81). In all, 12 of the infections occurred early and half of the infections involved the prosthesis, resulting in an increase of 11-fold in the cumulative hospital stay. Methicillin-resistant Staph. aureus was successfully eradicated in all the patients after a mean follow-up of 53.6 months (25 to 88). Superficial incisional infections resolved after antibiotic therapy alone while deep infections required multiple operative debridements. Attempted retention of the implant in early organ space infections was successful in only one of five patients. Only three patients with implant-level infections obtained a pain-free, functional prosthesis while a further three required excision arthroplasty. We have formulated a protocol of treatment which may serve as a guide in the management of these infections.

An electrode array that minimizes blood loss for radiofrequency-assisted hepatic resection.

Hepatic resection is currently the standard treatment for liver cancer. During hepatic resection part of the liver containing the tumor is surgically removed. This type of surgery is accompanied by high blood loss of approximately 0.6-1.35 L. Blood loss is associated with increased complication rates, prolonged hospital stay, and reduced patient survival, especially when transfusion is required. Other researchers have suggested using radiofrequency (rf) or microwave ablation to coagulate a tissue slice before resection to reduce blood loss, but conventional devices typically take several hours. We developed a device consisting of a linear array of blade-shaped, 1 cm wide radiofrequency (rf) electrodes 1.5 cm apart. Bipolar rf power is applied between pairs of adjacent electrodes, leading to high tissue temperatures between the electrodes that promote coagulation of large vessels (>3 mm) in the resection plane. Rapid switching of applied power between pairs of adjacent electrodes allows simultaneous heating and coagulation of the entire resection plane within 3-6 min. In seven in vivo trials in a porcine model, resection along a plane pre-coagulated with the device resulted in little (<20 mL) to no blood loss, while coagulating all vessels (up to 4.5 mm diameter in this study). Average treatment time (from placement of the device to transection) was 6.8+/-0.5 min when four electrodes were used, and 11.3+/-1.2 min when 5-7 electrodes were used. This device may reduce blood loss related morbidity during resection and reduce treatment time by coagulating all vessels in the resection plane.

The pharyngeal contractile integral is a useful indicator of pharyngeal swallowing impairment.

BACKGROUND: A limitation to the expanded use of high-resolution pharyngeal manometry (HRPM) in clinical practice is the lack of useful pharyngeal parameters that are easy to interpret, generalizable between patients, and do not require specialized software. In this study, we sought to test the relationship between the pharyngeal contractile integral (PhCI) with videofluoroscopic abnormalities as assessed with the Modified Barium Swallow Impairment Profile© ™. METHODS: Adult dysphagic patients were recruited to undergo simultaneous HRPM and videofluoroscopy during a standardized swallowing protocol. KEY RESULTS: Thirty-six patients were included in the study. The mean PhCI was 247 mm Hg·cm·s (range 2-488 mm Hg·cm·s). The lower pharyngeal total (PT) group (N=20; mean PT=3.9) had a mean PhCI of 299 mm Hg·cm·s, while the higher PT group (N=16; mean PT=12.7) had a mean PhCI score of 188 mm Hg·cm·s (P=.01). There was also a significant negative correlation between normalized PhCI to PT scores (r=-.47; P=.004). Patients with higher PhCIs exhibited less severe penetration-aspiration scores on thin liquids (1.44 vs 3.78; P=.03) and all consistencies combined (1.21 vs 1.99; P=.03). CONCLUSIONS & INFERENCES: The PhCI is a useful indicator of the presence of pharyngeal swallowing impairment and is technically simple to calculate with currently available software programs. Advancement of software is necessary to refine the clinical value of this parameter. High-resolution pharyngeal manometry has the potential to be a valuable adjunct procedure for the evaluation and treatment of dysphagic individuals.

Methicillin-resistant Staphylococcus aureus in an Irish orthopaedic centre: a five-year analysis.

This prospective five-year study analyses the impact of methicillin-resistant Staphylococcus aureus (MRSA) on an Irish orthopaedic unit. We identified 318 cases of MRSA, representing 0.76% of all admissions (41,971). A total of 240 (76%) cases were colonised with MRSA, while 120 (37.7%) were infected. Patients were admitted from home (218; 68.6%), nursing homes (72; 22.6%) and other hospitals (28; 8.8%). A total of 115 cases (36.6%) were colonised or infected on admission. Many patients were both colonised and infected at some stage. The length of hospital stay was almost trebled because of the presence of MRSA infection. Encouragingly, overall infection rates have not risen significantly over the five years of the study despite increased prevalence of MRSA. However, the financial burden of MRSA is increasing, highlighting the need for progress in understanding how to control this resistant pathogen more effectively.

Glucose, glutamine and ketone body utilisation by resting and concanavalin A activated rat splenic lymphocytes.

The utilisation of glucose, glutamine, acetoacetate and D-3-hydroxybutyrate were investigated over 72 h of incubation of rat splenic lymphocytes, with and without concanavalin A. Lymphocytes consumed both ketone bodies; acetoacetate was consumed preferentially. The ketone bodies reduced glucose consumption by 30-50%, but had little effect on lactate production. Glutamine uptake was concentration dependent up to 4 mM, and consumption was increased in the presence of concanavalin. Glutamine stimulated glucose consumption and lactate production in both resting and activated cells. Complete oxidation contributed 65% of glucose-derived ATP, but less than 40% of glutamine-derived ATP. Glutamine metabolism makes only a minor contribution to lymphocyte ATP generation.

The 'expert patient': empowerment or medical dominance? The case of weight loss, pharmaceutical drugs and the Internet.

Do 'informed' or 'expert' patients challenge dominant traditions in biomedicine or simply adopt these as conventional ways of thinking about body shape and size, illness and health? This paper examines this question in relation to the use of the weight-loss drug Xenical by participants in an Internet forum for obese and overweight people. Ethnographic and interview data from the forum provides evidence that participants share information and support each other as they use Xenical, and in the process emerge as 'expert patients' in relation to their body shape and its treatment. However, it is argued that while an 'expert patient' can be perceived as desirable, enabling the democratisation of healthcare, it can also be constraining. The exchanges between the users in the forum perpetuate a biomedical model of overweight as a condition to be overcome. The discussion critically considers a number of options for the development of the expert patient, including the emergence of an 'informed consumer'.

IgE receptor-mediated arachidonic acid release by rat basophilic leukemia (RBL-2H3) cells: possible role in activating degranulation.

Aggregation of the IgE receptor on rat basophilic leukemia (RBL-2H3) cells triggers increased hydrolysis of polyphosphoinositides (PI), secretion of arachidonic acid (AA) and its metabolites, and degranulation to release 5-hydroxytryptamine. Despite the documented involvement of second messengers produced by the PI pathway in RBL cell exocytosis, recent evidence has suggested that additional signalling events are also necessary. We have, therefore, examined PLA2 activation and AA metabolite production by these cells in response to Ag stimulation, and evaluated the potential role of these in activating degranulation. The time course and antigen dose dependence for release of AA and its metabolites were comparable to those for degranulation and production of inositol phosphates (InsPs) when examined in parallel. Stimulated fatty acid release was highly selective for AA (compared with oleic or linoleic acids) and appeared to result predominantly from PLA2 activation. AA released upon antigen stimulation is rapidly metabolized to produce prostaglandin and leukotrienes. These are not required for activating degranulation, since BW755c completely inhibited AA metabolite production without affecting AA release, degranulation or InsP production. In contrast, the PLA2 inhibitors quinacrine and quercetin inhibited both AA release and degranulation in parallel, without significantly affecting levels of InsP production, and this inhibition could be partially reversed by exogenous addition of AA and lysophospholipid. These results demonstrate that activation of IgE-receptor mediated exocytosis of RBL cells does not require AA metabolites, and strongly suggest that PLA2 activation and release of AA and lysophospholipid may be involved in triggering this response.

An evaluation of a group-based motivational intervention for substance misusers in an Irish forensic setting.

OBJECTIVE: The purpose of this pilot study was to evaluate a 12-session group-based motivational intervention for substance misusers in a prison setting. The intervention aimed to increase both participants awareness of problem substance use and motivation to change their substance use behaviour. METHOD: Participants were recruited for the intervention through active outreach in the prison. Participants of the intervention group completed a structured interview before the group commencing and standardised pre- and post-outcome measures. The results of the intervention group (n=31) were compared with a waiting list control group (n=11). RESULTS: Non-parametric analysis showed retention rates on this programme at 2, 4 and 6 weeks were 88%, 79% and 76%, respectively. Outcome data were consistent with the predicted direction for the treatment group compared with the wait-list control with significant between-group differences found on ambivalence and taking steps scores. CONCLUSION: This group-based intervention demonstrated positive levels of client engagement and retention. The intervention was also successful in reducing participant ambivalence about their drug use. Implications for service provision are discussed and design limitations of the present study are considered. Overall, findings indicate the potential utility of a group-based motivational intervention for substance misusers in forensic settings.

Use of a ground beef model to assess the effect of the lactoperoxidase system on the growth of Escherichia coli O157:H7, Listeria monocytogenes and Staphylococcus aureus in red meat.

The ability to preserve food in a state that is both appetising and nutritious is a basic requirement for health. Food poisoning represents a major source of illness and loss of productivity in many developed countries. Of particular concern in recent years are outbreaks of food poisoning associated with Escherichia coli O157:H7 or Listeria monocytogenes, many of which have been associated with the consumption of ground meat. Many of the chemicals presently licensed for use as food preservatives are increasingly being questioned with regard to their effects on humans, creating pressure on food suppliers to consider the use of 'natural' alternatives to these chemical agents. The potential use of one such agent, the lactoperoxidase system (LPS), for use in ground meat preparations is examined in this study. The degree of inhibition of growth of E. coli O157:H7, L. monocytogenes L45 and S. aureus R37 by LPS was examined in a broth system at 37 degrees C and in a ground beef system at 0, 6 and 12 degrees C. The degree of inhibition by LPS of natural populations of microorganisms present in ground beef obtained from eight retail outlets and incubated at room temperature was also examined. For each of the strains examined, sensitivity from most to least sensitive followed the order L. monocytogenes L45, S. aureus R37 and E. coli O157:H7. In each case the ability of LPS to inhibit growth was highly temperature dependent and maximal at a temperature permissive but not optimal for growth of the test strain. The numbers of bacteria detected in ground beef obtained from retail outlets varied considerably between the eight samples. In all cases, numbers of bacteria increased markedly in the uninhibited control over the 4 h incubation time and, with the exception of one faecal coliform count, growth of the microbial populations was strongly inhibited by the presence of LPS. It was concluded that LPS could potentially be applied to a considerably wider range of food products than those to which it is presently restricted.

Questionnaire development: an examination of the Nordic Musculoskeletal questionnaire.

This paper describes the outcome of user trials of the Nordic Musculoskeletal Questionnaire which encompassed the views of the following groups: data entry clerks, technical staff, administrative clerks and 481 subjects employed in 10 supermarkets. A significant number of improvements was identified, especially concerning its wording, layout and administration. This has led to a standardized version being produced for use in studying the prevalence of reported symptoms in many types of occupational groups.