We introduce an automated digital microfluidic (DMF) platform capable of performing immunoassays from sample to analysis with minimal manual intervention. This platform features (a) a 90 Pogo pin interface for digital microfluidic control, (b) an integrated (and motorized) photomultiplier tube for chemiluminescent detection, and (c) a magnetic lens assembly which focuses magnetic fields into a narrow region on the surface of the DMF device, facilitating up to eight simultaneous digital microfluidic magnetic separations. The new platform was used to implement a three-level full factorial design of experiments (DOE) optimization for thyroid-stimulating hormone immunoassays, varying (1) the analyte concentration, (2) the sample incubation time, and (3) the sample volume, resulting in an optimized protocol that reduced the detection limit and sample incubation time by up to 5-fold and 2-fold, respectively, relative to those from previous work. To our knowledge, this is the first report of a DOE optimization for immunoassays in a microfluidic system of any format. We propose that this new platform paves the way for a benchtop tool that is useful for implementing immunoassays in near-patient settings, including community hospitals, physicians' offices, and small clinical laboratories.

Summary The incidence of epiploic entrapment of the small intestine in horses undergoing celiotomy for colic was 5%. The condition was more prevalent in older (mean 9.81 years) gelding and Thoroughbred horses. Preoperative peritoneal protein level was a good prognostic indicator as it was significantly greater in the nonsurvivor (39.4 ± 5.10) group than in the survivor group (26.6 ± 14.0) (P<0.05). Abdominal ultrasonography allowed earlier diagnosis and surgical intervention in nonpainful cases with inconclusive rectal findings. Surgery was completed in 46 horses and 44 horses recovered from anaesthesia. Nine horses were either subjected to euthanasia in surgery (7 horses) or died in recovery (2 horses). Repeat laparotomies were pursued in 27% (12/44) of the horses. Seven horses (16%) showed post operative adynamic ileus which was the most common post operative complication. The incidence (6%) of adhesion formation was lower than previously reported. Other post operative complications included gastric ulceration, liver disease, diarrhoea and weight loss. Short and long term survival rates were 79% (35/44) and 70% (31/44) respectively. Improved rates were attributed to earlier referral and diagnosis and prompt surgical intervention. The aggressive use of repeat celiotomy and a more effective treatment of the endotoxic horse in the perioperative period contributed to survival.

Summary Laparoscopic intra‐abdominal ligation and removal of cryptorchid testes in horses was evaluated retrospectively in 50 horses that underwent the procedure between 1991 and 1996. Sixty‐one cryptorchid testes were removed by one of the following methods; the use of 1) an endoscoping stapling and transection device, 2) an endoscopic clipping device, 3) an endoscopic ligating loop. Monopolar electrosurgery was combined with these methods to facilitate coagulation and cutting of tissue. In 8 horses, 9 testes were retained between the internal and external inguinal rings. The inguinal testes were removed by cutting the internal inguinal ring and bringing the testis back into the abdomen for removal. No attempt was made to close the internal inguinal ring. The most frequently employed and most cost effective method for laparoscopic intra‐abdominal removal of cryptorchid testes in this study was the combined use of an endoscopic ligating loop and monopolar electrosurgery. One intra‐operative complication (perforation of the small intestine) occurred and was dealt with successfully. One horse developed a fever attributed to upper respiratory tract infection post operatively and was treated successfully with antibiotic. Intra‐abdominal ligation and transection of cryptorchid testes is an effective method for cryptorchid castration. This technique minimises the loss of insufflation, allows inspection of the cut tissue for haemorrhage and offers secure closure of the abdominal wall preventing inguinal herniation and excellent visualisation of the cryptorchid testis.

Summary Fifty‐three cases of equine mandibular fractures were managed surgically from 1988–1998, of which 16 (30%) were repaired by external skeletal fixation (ESF). Three surgical methods were utilised: transmandibular 4.76 or 6.35 mm Steinmann pins incorporated into fibreglass casting material or nonsterile dental acrylic (methyl methacrylate ‐ MMA) bars reinforced with steel; transmandibular 9.6 mm self‐tapping threaded pins ± 4.76 or 6.35 mm Steinmann pins incorporated into MMA bars reinforced with steel; and 4.5 mm or 5.5 mm ASIF cortical bone screws incorporated into MMA bars reinforced with steel or a ventral MMA splint. Fourteen horses were presented to the hospital for fixator removal at an average of 56.2 days. At removal, fractures were stable and occlusion of incisor and cheek teeth was considered adequate. Complications of the procedure occurred in 3 horses. Two horses with persistent drainage and ring sequestra from pin tracts required curettage 4 or 5 months after ESF removal. A third horse required replacement of the original fibreglass ESF with MMA bars to regain access to open, infected wounds. Another horse required removal of the second premolar at the time of fixator removal because the tooth root had been damaged in the original injury. ESF for the surgical management of mandibular fractures in horses has produced good results, with incisive and cheek tooth alignment reestablished in all horses. Horses that were managed via ESF had a rapid return to full feed and did not require any supplementation via nasogastric tube or oesophagostomy to maintain bodyweight or hydration status.

BACKGROUND:Whereas disease surveillance for infectious diseases such as rubella is important, it is critical to identify pregnant women at risk of passing rubella to their offspring, which can be fatal and can result in congenital rubella syndrome (CRS). The traditional centralized model for diagnosing rubella is cost-prohibitive in resource-limited settings, representing a major obstacle to the prevention of CRS. As a step toward decentralized diagnostic systems, we developed a proof-of-concept digital microfluidic (DMF) diagnostic platform that possesses the flexibility and performance of automated immunoassay platforms used in central facilities, but with a form factor the size of a shoebox.