An assessment of the delayed hypersensitivity reaction to methylated bovine serum albumin in the mouse and its use in the evaluation of drug effects on cell mediated immune reactions

A delayed hypersensitivity (DH) reaction is induced by a sensitizing intradermal injection of methylated bovine serum albumin (MBSA) into the abdomen of mice and a subsequent challenge injection of MBSA into the hind paw. Paw volume increase is measured by mercury plethysmography. The conditions for sensitization have been investigated. Sensitization with a 0.25% MBSA emulsion resulted in a small but significant swelling of the paw following the challenge injection. The magnitude of the footpad response to the challenge injection was increased if the antigen administered in the sensitizing injection was emulsified with Freund's incomplete adjuvant. Incorporation ofMycobacterium butyricum in the emulsion greatly increased the footpad response if added at doses of 0.05 and 1 mg per animal. A higher dose (4 mg), however, resulted in a lower response. The time course of development of the delayed hypersensitivity reaction has been studied. An 8-day interval between sensitization and challenge resulted in a greater delayed hypersensitivity response than a shorter (3-day) or longer (15-, 21-, 28-day) interval. Cyclophosphamide (250 mg kg^–1) administered 3 days prior to the sensitizing injection of MBSA produced a modest enhancement of the DH reaction.On the basis of these studies a protocol for conducting the DH reaction to MBSA was established and the activity of drugs on processes underlying the sensitization phase of the reaction or processes underlying the elicitation phase of the reaction have been examined. Steroid and immunosuppressant drugs were found to inhibit the DH footpad response when dosed during the sensitization whereas several specific-anti-rheumatic and immunoactive compounds were without effect. Indomethacin and sudoxicam inhibited the DH reaction if dosed during the elicitation of the reaction but other non-steroidal anti-inflammatories tested did not significantly reduce the response. The clinically used anti-rheumatic drugsd-penicillamine and levamisole did not inhibit the elicitation phase of the DH response but niridazole at 100 mg kg^–1 did reduce the inflammatory response.This paper has been presented in part as a poster presentation to the British Pharmacological Society, 4–6 January 1978.     

A scoping review of the progress of the evolution of the Doctor of Nursing Practice in the USA to inform consideration of future transformation of Nurse Practitioner education in Australia

Background

In 2004 a consensus was reached through a vote of membership of the American Association of Colleges of Nursing to move Nurse Practitioner education from the masters to the doctoral level by 2015.

Acute surgical unit safely reduces unnecessary after-hours cholecystectomy

Introduction

The acute surgical model has been trialled in several institutions with mixed results. The aim of this study was to determine whether the acute surgical model provides better outcomes for patients with acute biliary presentation, compared with the traditional emergency surgery model of care.

Methods

A retrospective review was carried out of patients who were admitted for management of acute biliary presentation, before and after the establishment of an acute surgical unit (ASU). Outcomes measured were time to operation, operating time, after-hours operation (6pm – 8am), length of stay and surgical complications.

Results

A total of 342 patients presented with acute biliary symptoms and were managed operatively. The median time to operation was significantly reduced in the ASU group (32.4 vs 25.4 hours, p=0.047), as were the proportion of operations performed after hours (19.5% vs 2.5%, p<0.001) and the median length of stay (4 vs 3 days, p<0.001). The median operating time, rate of conversion to open cholecystectomy and wound infection rates remained similar.

Conclusions

Implementation of an ASU can lead to objective differences in outcomes for patients who present with acute cholecystitis. In our study, the ASU significantly reduced time to operation, the number of operations performed after hours and length of stay.     

Management of choledocholithiasis in an emergency cohort undergoing laparoscopic cholecystectomy: a single-centre experience

Introduction

Minimally-invasive options for the management of choledocholithiasis in patients undergoing laparoscopic cholecystectomy include laparoscopic and endoscopic approaches. This study reviews the effectiveness of both approaches in an emergency setting.

Methods

A retrospective chart review was performed for a cohort of patients who underwent laparoscopic cholecystectomy. Outcomes assessed were duct clearance, the number of procedures performed (NPP), length of stay (LOS) and complication rate.

Results

A total of 182 patients who underwent emergency laparoscopic cholecystectomies received intervention for choledocholithiasis. The duct clearance rate was lower in the laparoscopic group, 63% versus 86% (P = 0.001). However, the median NPP was also lesser in the laparoscopic group, 1 (interquartile range (IQR) 1–2) versus 2 (IQR 2–2) (P < 0.001), as was the median LOS, 5 days (IQR 3–8) versus 7 days (IQR 6–10) (P = 0.009). Forty-eight laparoscopic endobiliary stents were attempted; stent deployment was successful in 37 patients. A larger proportion of patients with laparoscopic endobiliary stents had duct clearance by endoscopic retrograde cholangiopancreatography (ERCP) compared with those without, although this was not statistically significant (P = 0.208).

Conclusion

Laparoscopic clearance is not as effective as post-operative ERCP in an emergency cohort, but is associated with fewer procedures required and a shorter inpatient stay. Thus, laparoscopic clearance may still be an attractive option for surgeons especially where conditions are favourable during an emergency laparoscopic cholecystectomy.