Preliminary results for the use of knee mega‐endoprosthesis in the treatment of musculoskeletal complications of haemophilia

Complications of haemophilia in the knee region are rare and difficult to treat. Use of surgical treatments such as total knee arthroplasty cannot satisfactorily restore knee function in patients with these complications, which include massive haemophilic pseudotumour, fracture around the knee and haemarthrosis. To analyse the postoperative results of patients suffering from complications of haemophilia and treated with a knee mega‐endoprosthesis, to discuss and compare this type of surgical management with other types of treatments used in similar cases. We retrospectively analyse the surgical results of patients who were treated with a knee mega‐endoprosthesis for complications of haemophilia. Three severe haemophilic arthritic knees, of which two were combined with femoral condylar fractures, were treated in a one‐stage surgery, and another two knees which presented with massive haemophilic pseudotumours and bony defects were treated in a two‐stage operation. Mean age at time of surgery was 28.5 years old and mean follow‐up time was 22.8 months; the mega‐endoprosthesis surgery was successfully performed in four cases and the mean range of motion increased from 29.5° preoperatively to 96.75° postoperatively. The Knee society score function score value increased from 25 to 82.5. One knee was amputated because of uncontrollable recurrent haemorrhage. Roentgenograms did not show any signs of loosening of the prostheses. Use of Mega‐endoprosthesis in the treatment of complications of haemophilia can offer patients suffering from massive pseudotumours with bone defect, severe contracture knee haemophilic arthritis and fractures around a haemophilic knee a viable treatment option.     

Validation of the 25-Item Stanford Faculty Development Program Tool on Clinical Teaching Effectiveness

Construct: The 25-item Stanford Faculty Development Program Tool on Clinical Teaching Effectiveness assesses clinical teaching effectiveness. Background: Valid and reliable rating of teaching effectiveness is helpful for providing faculty with feedback. The 25-item Stanford Faculty Development Program Tool on Clinical Teaching Effectiveness was intended to evaluate seven dimensions of clinical teaching. Confirmation of the structure of this tool has not been previously performed. Approach: This study sought to validate this tool using a confirmatory factor analysis, testing a 7-factor model and compared its goodness of fit with a modified model. Acceptability of the use of the tool was assessed using a 6-item survey, completed by final year medical students (N = 119 of 156 students; 76%). Results: The testing of the goodness of fit indicated that the 7-factor model performed poorly, χ²(254) = 457.4, p < .001 (root mean square error of approximation [RMSEA] = 0.08, comparative fit index [CFI] = 0.91, non-normed fit index [NNFI] = 0.89). Only standardized root mean square residual (SRMR) indicated acceptable fit (0.06). Further exploratory analysis identified 10 items that cross-loaded on 2 factors. The remainder of the items loaded on factors as originally intended. By removing these 10 items, repeat confirmatory factor analysis on the modified 15-item, 5-factor model demonstrated a better fit than the original model: SRMR = 0.075, NNFI = 0.91, χ²(80) = 150.1, p < .001; RMSEA = 0.09; CFI = 0.93. Although 75% of the participants stated they were willing to fill the tool on their preceptors on a biweekly basis, only 25% were willing to do so on a weekly basis. Conclusions: Our study failed to confirm factor structure of the 25-item tool. A modified tool with fewer, more conceptually distinct items was best fit by a 5-factor model. Further, the acceptability of use for the 25-item tool may be poor for rotations with a new preceptor weekly. The abbreviated tool may be preferable in that setting.     

"Borderline" myocarditis: an indication for repeat endomyocardial biopsy

Repeat endomyocardial biopsy was performed in 28 patients with dilated cardiomyopathy of less than or equal to 12 months' duration and either symptomatic heart failure or life-threatening ventricular arrhythmias. Myocarditis was strongly suspected clinically in all cases, yet was unconfirmed on initial right ventricular biopsy. Seventeen patients underwent both right and left ventricular biopsy, seven patients had a repeat right ventricular biopsy and four patients underwent repeat left ventricular biopsy alone. The interval between initial and repeat biopsy averaged 31 +/- 6 days. Myocarditis was confirmed on repeat biopsy in 4 of 6 patients whose initial biopsy revealed "borderline" myocarditis (that is, interstitial inflammation but absence of myocyte necrosis) compared with none of the 22 patients whose initial biopsy showed either myocyte hypertrophy or interstitial fibrosis, or both (p = 0.0007). "Borderline" myocarditis on initial biopsy was the only clinical or histologic finding predictive of myocarditis on subsequent biopsy. Repeat endomyocardial biopsy can identify and potentially modify the treatment of an additional group of patients with dilated cardiomyopathy and nondiagnostic initial endomyocardial histologic features. Right ventricular sampling should be repeated in patients whose initial biopsy demonstrates "borderline" myocarditis.     

Bromocriptine alters hormone rhythms and lipid metabolism in swine

Hormones, metabolites and activities involved in lipid synthesis were assayed in pigs made leaner by bromocriptine treatment. Market size female swine were allowed free access to food under natural lighting conditions and implanted with bromocriptine pellets designed to release 10 mg/pig/day for 28 days in an effort to inhibit prolactin secretion. Between the 2nd and 3rd week of treatment, plasma samples were obtained from each group at 4-hour intervals throughout the day for assays of prolactin, cortisol, insulin, triglyceride, cholesterol and glucose concentrations. Twenty-eight or thirty days after the implantations, all animals were sacrificed for determinations of backfat thickness and insulin binding in the liver. At sacrifice, bromocriptine treatment reduced backfat thickness by 14% and insulin binding to partially purified hepatic membranes by 39% compared with control values. At 14 days following implantations, there were dramatic daily variations in plasma cortisol and prolactin levels in the control pigs and these rhythms were markedly altered in phase and amplitude in the bromocriptine-treated pigs. Bromocriptine reduced by 45, 20 and 13% the high levels of triglyceride, glucose, and cholesterol, respectively, that were found in control pigs near sunset. Plasma insulin concentrations did not vary during the day in control pigs and bromocriptine did not influence the insulin levels. The findings support important roles for a temporal synergism of cortisol and prolactin rhythms in maintaining hepatic lipogenic responsiveness to insulin. Bromocriptine treatment alters these hormonal relations and reduces lipid synthesis.     

Echicetin: a snake venom protein that inhibits binding of von Willebrand factor and alboaggregins to platelet glycoprotein Ib

Echicetin, a new protein isolated from Echis carinatus venom by reverse phase and ion exchange chromatography specifically inhibited agglutination of fixed platelets induced by several platelet glycoprotein Ib (GPIb) agonists, such as bovine von Willebrand factor (vWF), alboaggregins, and human vWF in the presence of botrocetin. Unlike alboaggregins, echicetin bound to GPIb but did not induce agglutination of washed or fixed platelets. In contrast to disintegrins, it did not block adenosine 5'-diphosphate (ADP)-induced platelet aggregation in the presence of fibrinogen. The apparent molecular weight of echicetin measured on sodium dodecyl sulfate (SDS) gel electrophoresis was 26 Kd under nonreducing conditions. On reduction, echicetin showed 16 and 14-Kd subunits suggesting that the molecule is a dimer. Reduced echicetin retained its binding activity and its inhibitory effect on the agglutination of fixed platelets induced by bovine vWF. 125I-echicetin bound to fixed platelets with high affinity (kd = 30 +/- 1.8 nmol/L) at 45,000 +/- 2,400 binding sites per platelet. The binding was selectively inhibited by a monoclonal antibody to the 45-Kd N-terminal domain of platelet GPIb, but not by monoclonal antibodies to other regions on GPIb. Binding of 125I-bovine vWF to fixed platelets was strongly inhibited by echicetin. In contrast, bovine vWF showed a much weaker inhibitory activity on binding of 125I-echicetin to platelets. The half life of echicetin in blood was approximately 170 minutes with no detectable degradation. Echicetin significantly prolonged the bleeding time of mice, suggesting that it may inhibit vWF binding to GPIb in vivo as well as in vitro.     

Effect of surfaces on fluid-phase prekallikrein activation

The activation of prekallikrein by factor XII fragments (XIIf), during incubation in plastic tubes was previously noted to be increased by high molecular weight (HMW) kininogen as well as other plasma proteins. In this report, we investigated the mechanism responsible for this increase. Although we confirmed that HMW kininogen, bovine serum albumin, fibrinogen, cold insoluble globulin, and mixed phospholipids apparently increased prekallikrein activation, we found that the product of prekallikrein activation (kallikrein) lost substantial activity in less than 0.5 min after exposure to a variety of fresh surfaces. This loss was partially prevented by the presence of various proteins and phospholipids. Similar protection against inactivation of XIIf, the enzyme in this reaction, was also found. In contrast, no loss of the substrate, prekallikrein, was observed during incubation. The loss of kallikrein activity was found to be proportional to the surface area of the incubation vessel as well as the concentration of kallikrein. Further loss of kallikrein activity could also be prevented by pretreating the vessel with kallikrein. We therefore conclude that various substances apparently affect prekallikrein activation in a purified system by preventing the enzyme and product in the reaction mixture from losing activity due to adsorption to a surface.     

Fractionated total-body irradiation and high-dose etoposide as a preparatory regimen for bone marrow transplantation for 94 patients with chronic myelogenous leukemia in chronic phase

Ninety-four consecutive patients with chronic myelogenous leukemia in first clinical chronic phase, median age of 34.0 years (range, 6.8 to 52.4 years), with a histocompatible sibling donor, were treated with fractionated total body irradiation (1,320 cGy) and high-dose etoposide (60 mg/kg) followed by allogeneic bone marrow transplantation (BMT). The median time from diagnosis to BMT was 7.0 months (range, 2.3 to 72.0 months). Sixty patients were treated before BMT with hydroxyurea alone, four patients with busulfan alone, one patient with interferon alone, and the other 29 patients were treated with various combinations of these drugs. Cumulative probabilities of overall survival, event- free survival, and relapse at 5 years were 73%, 64%, and 14%, respectively. The median follow-up time for surviving patients was 38 months, ranging from 12 to 88 months. By stepwise Cox regression analysis, significant prognostic variables were age at transplant, acute graft-versus-host disease > or = grade II, cytomegalovirus- associated interstitial pneumonitis, and years from diagnosis to BMT.     

八年制医学教育临床导师制探索

在八年制医学教育专业临床医学课程学习、见习、实习阶段实施临床导师制是我校一项颇具特色的探索.通过对2005、2006级学生实施临床导师制的情况进行分析和总结发现,临床导师对培养学生临床思维、职业精神,提升其临床和科研能力有着积极作用.但存在导师专业性过强、业务繁忙、对培养目标定位不清等问题,需要对导师制进一步优化和完善,以更好地适应八年制医学人才培养的需要,并为国内八年制医学教育改革提供参考.     

The power of words: sources of anxiety in patients undergoing local anaesthetic plastic surgery

INTRODUCTION

With local or regional anaesthesia being employed for more as well as more complex surgical procedures, an increasing number of patients remain fully conscious during their operation. This is generally perceived as being advantageous to the patient as less time is spent in hospital and the side effects of general anaesthesia are avoided. However, there is no direct measure of the patient experience during ‘awake surgery’, in particular of which aspects of the process may be distressing.

METHODS

Seventy patients undergoing day case plastic surgery under local anaesthesia were asked to complete a short questionnaire immediately following their operation. This was designed to identify specific factors likely to either increase or reduce anxiety during surgery. The questionnaire was initially validated on a pilot group of ten patients.

RESULTS

Unsurprisingly, painful stimuli such as injections were identified as potential stressors. More interestingly, the data highlighted that some commonly used surgical terms such as ‘knife’ and ‘scalpel’ provoke considerable anxiety in the conscious patient. This varied according to age and sex with younger and female patients being most vulnerable. Other events identified as potential stressors, such as casual conversations and movements among theatre staff, were actually shown to be non-stressful and, in some cases, stress relieving.

CONCLUSIONS

Technical jargon used by surgical staff can elevate anxiety levels among patients who are awake for their operation. Careful consideration of the words we use may reduce this, particularly in female patients.