Differential binding of P. aeruginosa and S. aureus to corneal epithelium in culture

Adherence of bacteria to corneal epithelium is a prerequisite for corneal infection. We used two methods to study the binding of Pseudomonas aeruginosa and Staphylococcus aureus to rabbit corneal epithelial cells in culture. In the first method, rabbit corneal epithelial cells grown on glass slides were incubated with P. aeruginosa or S. aureus (10(7) CFU/ml) at room temperature for 90 min, and the bacterial binding to the epithelial cells was examined by light microscopy. Both P. aeruginosa and S. aureus bound to epithelial cells. P. aeruginosa was bound to the cell periphery whereas S. aureus was bound randomly to the cell surface. In the second method, suspension cultures of corneal epithelial cells were used. In contrast to the findings in cultures on slides, binding pattern with cells in suspension was similar for both species and resembled that for S. aureus in cultures on slides. A much greater number of P. aeruginosa (186 +/- 11 bacteria/epithelial cell) than S. aureus (30 +/- 1.5 bacteria/epithelial cell) bound to epithelial cells grown on glass slides. In contrast, a similar number of P. aeruginosa (25 +/- 5.1) and S. aureus (20 +/- 4.7) bound to epithelial cells grown in suspension cultures. Using either method, Escherichia coli and Streptococcus pyogenes did not bind significantly (less than 5/cell) to corneal epithelial cells. The above methods should prove useful for characterization of bacterial binding to corneal epithelial cells in culture.     

Videothoracoscopy in the treatment of early empyema: an initial experience.

Seventeen consecutive patients were referred for management of empyema between April 1991 and March 1992. Fourteen patients defined as having an 'early' empyema were initially treated by videothoracoscopy. The other three patients, defined as having a 'late' empyema proceeded directly to thoracotomy. Videothoracoscopy was successful in 10 out of the 14 patients. The mean postoperative stay was 7.8 days. At a mean follow-up at 16.7 months, these patients were rendered apyrexial with full lung expansion and no residual pleural collection. The postoperative results were at least equivalent to other conventional forms of treatment without an undue level of complications. In this series, thoracoscopy was found to be successful when symptoms had been present up to 31 days before presentation at the first hospital, and the mean length of treatment before referral to Harefield was 47 days. It is now our policy to videothoracoscope all patients with empyema thoracis, regardless of the length of referral. It may circumvent the need for a thoracotomy, it does not add any increased risk of complications, and does not appreciably increase the length of hospital stay should thoracotomy ultimately be required.     

P07Reduction of Allogeneic Red Cell Transfusion using Autologous Blood Cell Salvage in Knee Arthroplasty

Recent Hospital Transfusion Committee (HTC) audit at the Royal Bournemouth Hospital (RBH) confirmed an allogeneic red cell transfusion rate of 20% for primary Total Knee Replacement (TKR). Current policy at RBH states that when blood stocks reach 67% of normal (amber alert) then surgery with a >20% likelihood of blood transfusion will be cancelled. At current transfusion rates this would include primary TKR. Recent studies have shown a reduction in allogeneic transfusion rates when autologous transfusion drains are utilized. The purpose of this study was to see whether the current rate of allogeneic transfusion could be reduced with the introduction of the CellTransTM Autologous Knee Drainage Blood Transfusion System (ABT) in TKR at RBH. Over a 3 month period all patients undergoing primary, bilateral or revision knee arthroplasty received an ABT. Demographic data was collected from the orthopaedic pre‐assessment clinic. Following surgery further data was collected relating to volume of blood loss into the drain, volume of autologous blood re‐transfused, units of allogeneic blood required and the transfusion trigger, postoperative haemoglobin levels, infection rates and length of stay in hospital. We then compared this data set with retrospective data. Of 170 patients undergoing knee arthroplasty 141 received the ABT. The data collected was compared retrospectively with 169 patients from the previous 3 month period. We demonstrated a reduction in transfusion rates of 13% for primary TKR, 42% for bilateral TKR and 57% for revision TKR with the use of the ABT. In addition we demonstrated a reduction in total allogeneic blood use (99 units to 26 units) and a reduction in mean length of stay in hospital (8.6 days to 7.5 days) with the ABT. Further analysis of the data collected showed a 46% reduction in the allogeneic transfusion rate and a reduction in total allogeneic blood usage (99 units to 9 units) of anaemic patients presenting for surgery. This study has demonstrated a dramatic reduction in allogeneic blood transfusion rates with the use of the CellTransTM Autologous Blood Transfusion System. We have also shown a reduction in length of stay in hospital. Prior to the study primary total knee replacement would have been cancelled during times of limited blood availability (amber alert). The use of the ABT is good for the patient in reducing the need for allogeneic blood, and in addition has demonstrated a significant cost saving due to the reduced blood usage and potential prevention of cancelled operation lists.     

Mechanisms and patient compliance of dust-mite avoidance regimens in dwellings of mite-allergic rhinitic patients

We report on the mechanisms, the environmental changes and patient compliance with regard to conventional and new dust and mite avoidance measures to prevent allergic symptoms caused by mite allergens, taking into account both allergen contamination and the developmental success of pyroglyphid Acari. Twenty patients with persisting rhinitic complaints were selected and matched. Although the patients had performed some conventional dust and mite avoidance measures (patient compliance was 90%), the dwellings proved to be a stimulus for mite development. Moisture problems due to faulty construction and excessive moisture production were common. Since humidity conditions could not be changed at short notice, the 20 homes were subjected to the new variants of mite allergen avoidance based on intensive cleaning without (control) and with an acaricide incorporated (acaricidal cleaner [Acarosan]). After the carrying out of conventional avoidance measures, these patients still had allergic symptoms, and dust from only 23 to 52% of their textile objects was under the proposed guanine (mite faeces indicator) risk level. Only the acaricidal cleaner was able to decrease the allergenic mite load (and the burden of the patients) significantly in this 12 month period. With respect to mite-extermination, acaricidal cleaning was 88% better than intensive cleaning. Reduction of guanine was 38% better in the Acarosan treatment group. Clinical results have been reported elsewhere. A significant difference in favour of the acaricidal cleaning was seen in both subjective (as regards symptoms) and in objective data (total IgE). Another 50 patients were questioned. About 90% were willing to spend two weekends (70%), or at the most one weekend (20%) per year sanitizing the dwelling by cleaning it with the whole family. The authors of this report consider acaricidal cleaning to be a significant improvement in the management of mite-allergic diseases, such as rhinitis. Compared with the replacement of home textiles, this treatment is less expensive and more effective. Patient compliance is acceptable, but depends on acceptance by physicians and the initial motivation and consequent burden on the patient.     

Complications associated with the use of an infusion pump during knee arthroscopy.

This is a report of four complications from the use of an automated arthroscopy pump in 283 patients undergoing knee arthroscopy. The first patient had extravasation of fluid into the thigh, requiring discontinuation of the procedure. The second patient developed a compartment syndrome of the leg, necessitating a four-compartment fasciotomy of the leg. The third patient developed severe fluid extravasation into the anterior thigh compartment. A limited fasciotomy of the anterior thigh compartment was performed. The fourth patient developed moderate extravasation into the anterior part of the thigh and groin, necessitating discontinuation of pump irrigation and conversion to gravity irrigation to complete a partial medial meniscectomy. During a 15-month period, a complication rate of 1.4% from fluid extravasation during knee arthroscopy was noted. This review represents our initial experience with the infusion pump. No cases of fluid extravasation have occurred subsequently during a 12-month period.     

Control of feeding and sexual behaviors by neuropeptide Y: physiological implications

Recent evidence suggests that a variety of hypothalamic neuropeptides may mediate interneuronal communication to coordinate diverse neuroendocrine and behavioral functions. In this work, we describe the effects of neuropeptide Y (NPY) on feeding and sexual behaviors. We observed that central administration of bolus NPY stimulated a robust, dose-related feeding response in satiated male and female rats. Continuous NPY receptor activation also evoked dose-related, intermittent feeding in a manner normally observed during nocturnal feeding. It appears that the paraventricular nucleus in the hypothalamus may be the primary site of NPY action because the anticipated reciprocal changes in NPY concentrations, in response to food deprivation followed by ad libitum food intake, occurred only in this site. Additional findings revealed that NPY-induced feeding may follow either substantial reduction or complete restraint of an inhibitory influence on feeding mediated by alpha 2-adrenoreceptor systems in satiated rats. Further, NPY was found to suppress male and female sexual behaviors. The suppressive effects on sexual behavior were apparent prior to or at the time of the onset of feeding after NPY administration. These observations may provide a neurochemical basis for clinical and animal studies on disorders of feeding associated with diminished reproductive functions.