Deciphering the inflection points to achieve proficiency for each procedure step during training in laparoscopic appendicectomy.

BACKGROUND: Laparoscopic appendicectomy is a common procedure early in surgical training. A minimum number is usually required for certification in general surgery. However, data on proficiency are scarce. This study aimed to investigate steps towards proficiency in laparoscopic appendicectomy. METHODS: This was a prospective observational cohort study of laparoscopic appendicectomies performed by junior trainees under supervision scored on a six-point performance scale. Structured assessment was done within a defined programme. Procedures performed for uncomplicated appendicitis in adults were included. The procedures were evaluated with LOWESS graphs generated to investigate inflection points. Factors associated with proficiency rates were reported with odds ratios and 95 per cent confidence intervals. RESULTS: In total 142 laparoscopic procedures were included for 19 trainees (58 per cent female). The cumulative number of procedures during the study was a median of 20 (i.q.r. 8-33). For overall proficiency, an inflection point occurred at 30 procedures. Proficiency rate increased from 51 per cent for 30 or fewer procedures to 93 per cent for more than 30 procedures (odds ratio 11.9 (95 per cent c.i. 3.4 to 40.9); P < 0.001). Inflection points for proficiency for each procedure step varied considerably, with lowest numbers (fewer than 15 procedures) for removing the specimen, and highest for dividing the mesoappendix (more than 55 procedures). Operating time was significantly reduced by a median of 7 minutes after 30 procedures, from median 62 (i.q.r. 25-120) minutes to median 55 (i.q.r. 30-110) minutes for more than 30 procedures. CONCLUSION: For junior trainees, variation in proficiency is related to specific procedure steps. Targeted training on specific procedure skills may reduce numbers needed to achieve proficiency in laparoscopic appendicectomy during training.

Gamma nail vs compression screw for trochanteric femoral fractures. 15 reoperations in a prospective, randomized study of 378 patients.

A total of 378 trochanteric and subtrochanteric femoral fractures were randomized to treatment with Gamma nail (177) or Hip Compression Screw (HCS) (201). After a median follow-up time of 17 (10-27) months, 15 patients needed reoperations; 13 had been treated with Gamma nail and 2 with HCS. 10 patients, all treated with Gamma nail, were reoperated because of a femoral shaft fracture. 5 of these fractures occurred 8 (4-10) days postoperatively and were related to intraoperative complications. The other 5 shaft fractures occurred a median of 2 (1-3) months postoperatively after falls, and may be related to stress concentration at the tip of the solid nail. The lag screw cut out or penetrated the femoral head in 5 patients, 3 of them treated with Gamma nail and 2 with HCS.

Proteolysis of factor Va by factor Xa and activated protein C.

Bovine Factor Va, produced by selective proteolytic cleavage of Factor V by thrombin, consists of a heavy chain (D chain) of Mr = 94,000 and a light chain (E chain) of Mr = 74,000. These peptides are noncovalently associated in the presence of divalent metal ion(s). Each chain is susceptible to proteolysis by activated protein C and by Factor Xa. Sodium dodecyl sulfate electrophoretic analysis indicates that cleavage of the E chain by either activated protein C or Factor Xa yields two major fragments: Mr = 30,000 and Mr = 48,000. Amino acid sequence analysis indicates that the Mr = 30,000 fragments have identical NH2-terminal sequences and that this sequence corresponds to that of intact E chain. The Mr = 48,000 fragments also have identical NH2-terminal sequences, indicating that activated protein C and Factor Xa cleave the E chain at the same position. Sodium dodecyl sulfate electrophoretic analysis indicates that activated protein C cleavage of the D chain yields two products: Mr = 70,000 and Mr = 24,000. Amino acid sequence analysis indicates that the Mr = 70,000 fragment has the same NH2-terminal sequence as intact D chain, whereas the Mr = 24,000 fragment does not. Factor Xa cleavage of the D chain also yields two products: Mr = 56,000 and Mr = 45,000. The Mr = 56,000 fragment corresponds to the NH2-terminal end of the D chain and Factor V. Functional studies have shown that both chains of Factor Va may be entirely cleaved to products by Factor Xa without loss of activity, whereas activated protein C cleavage results in loss of activity. Since activated protein C and Factor Xa cleave the E chain at the same position, the cleavage of the D chain by activated protein C is responsible for the inactivation of Factor Va.

Diabetic control is improved by guar gum and wheat bran supplementation.

Twenty-eight insulin-dependent diabetics were treated with different dietary regimes for three periods of three months. Initially they used a white flour bread (run-in period), then their daily bread ration was enriched with guar gum (mean dose: 29 g), and then with wheat bran (mean dose: 33 g) in a randomized crossover pattern. Fasting and postprandial blood glucose levels were measured on filter paper spots collected once weekly at home, and other biochemical values were measured monthly. No improvement in diabetic control was seen during the run-in period. Mean postprandial blood glucose decreased from 12.0 +/- 3.8 mmol/l (mean +/- SD) in the run-in period to 9.7 +/- 2.8 mmol/l (p less than 0.01) in the guar period and to 9.7 +/- mmol/l (p less than 0.01) in the bran period. HbA1 decreased from 10.5 +/- 2.1% in the run-in period to 9.7 +/- 1.6% (less than 0.05) at the end of the guar period and 9.9 +/- 1.2% (not significant) at the end of the bran period. Only modest changes were seen in serum-lipids--total cholesterol decreased significantly in the guar period, but not in the bran period. In this study both guar gum and wheat bran were well tolerated and produced a substantial decrease in postprandial blood glucose.

Purification of six human vitamin K-dependent proteins in a single chromatographic step using immunoaffinity columns.

The major human vitamin K-dependent proteins were purified from plasma using immunoadsorbents made with antibodies specific for each protein. Monoclonal antibodies to Factor VII, Factor IX, Factor X, Protein C, and Protein S were prepared from mice immunized with isolated vitamin K-dependent antigens. Purified monoclonal antibodies and a purified burro polyclonal anti-prothrombin immunoglobulin were individually coupled to Sepharose and used in a tandem series of columns to purify each of the vitamin K-dependent proteins from eluates of barium citrate precipitates of plasma. The proteins were eluted from the columns by sodium thiocyanate and retained functional activity following dialysis. Prothrombin, Factor VII, Factor IX, Factor X and Protein C were essentially homogeneous as judged by NaDodSO4-PAGE; Protein S was isolated as a Protein S-C4b binding protein complex. These results indicate the utility of monoclonal antibody immunoadsorbents for purifying the human vitamin K-dependent proteins and represent a considerable simplification over other purification schemes.