新型塑质夹板的力学性能测试和分析

目的探讨新型塑质克雷氏夹板在不同力学状态下的力学参数,为临床应用提供依据.方法取6套塑质夹板和6套柳木夹板,随机分为2组,每组再随机编号,分别进行横向及纵向弯曲测试,得出两个方向的弯曲最大载荷和对应位移,并进行对比,从而也计算出两种夹板的弹性模量.结果在横向弯曲方向塑质夹板明显大于柳木夹板(P<0.01);在纵向弯曲方向两者无显著性差异(P>0.05).新型塑质夹板在不同受力状态下的弹性模量相同,而柳木夹板在不同受力状态下弹性模量不同,两者间有显著性差异(P<0.01).结论新型塑质夹板力学性质稳定,是一种理想的外固定材料.     

Reduced ischemia-reperfusion injury in muscle Experiments in rats with EPC-K1, a new radical scavenger

L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1 -benzopyran-6-yl hydrogen phosphate] potassium salt (EPC-K1), a phosphate diester of alpha-tocopherol and ascorbic acid, is a potent antioxidant. We examined the effects of EPC-K1 on ischemia-reperfusion injury in the skeletal muscle of rats, using an ischemic revas-cularized hind limb model. Warm ischemia (25 C), produced by vascular pedicle clamping, was sustained for 4 hours. After 24 hours of reperfusion, skeletal muscle injury was evaluated in 2 groups: one group treated by intravenous injection of EPC-K1 (10 mg/kg) prior to ischemia, and a group of controls. The EPC-K1 -treated group showed a statistically significant amelioration in the reduction of the isometric muscle contraction, inhibition of the elevation of the muscle wet- to dry-weight ratio, limitation of the muscle level of thiobarbituric acid reactive substances and the serum levels of creatine phos-phokinase, lactate dehydrogenase and mitochondrial glutamic oxaloacetic transaminase, and reduction of the extent of muscle injury according to the histological findings. These observations indicate that EPC-K1 acted effectively on ischemia-reperfusion injury in the rat skeletal muscle and thereby improved muscle function.     

Glucose infusion test: a new screening test for vascular access recirculation

BACKGROUND: Vascular access recirculation is an important cause of diminished dialysis efficiency. We propose a new screening test based on glucose infusion as a tracer for recirculation. METHODS: The glucose infusion test (GIT) protocol comprises a basal blood sample (A) from the arterial port, a 5 mL bolus of 20% glucose into the venous chamber (time 0), followed by a second sample (B) in four seconds (from 13 to 17 s with QB 300 mL/min) from the same port. The blood glucose level is determined at the bedside on A and B with a reflectance photometer (CV 1.8%). Interpretation of the test is straightforward: If B = A, there is no recirculation, whereas if B > A, recirculation can be calculated from the regression equation: 0.046 x (B - A) + 0.07, obtained from in vitro tests reproducing artificial recirculation at 0, 5, and 10%. To validate this new method in vivo, we compared GIT and the urea test on 39 hemodialysis patients, obtaining a good correlation (r = 0.93). The two tests were considered positive (recirculation present) when the lower 95% confidence intervals were more than zero. RESULTS: Our patients were divided into two groups: those with (22 out of 39, mean recirculation 11.8%) or without recirculation (17 out of 39, mean 0.06%). The urea test did not recognize 7 out of 22 patients because they had a small recirculation below the urea test limit of detection. CONCLUSIONS: GIT was more sensitive (detection limit 0.3%), simpler, and immediate in showing the results than the urea test. It is an accurate and low-cost technique for screening and follow-up of vascular access in a dialysis unit.     

Digital videoproctoscopy: a new diagnostic test in proctology

The proctological examination is usually simple, it can be done even without specific preparation. It is completed by proctoscopy, enabling the surgeon to confirm a clinical suspicion and make a differential diagnosis. Proctoscopy, however, may present a number of difficulties: the embarrassing position (both in the Sims and in the genupectural position; the operator is very close to the perineum of the patient); it is not possible to provide visual evidence of the pathology; there are no data archives; no comparison of two examinations can be made after a certain period of time (e.g. to test the validity of the therapy adopted). For these reasons patients are often invited to undergo a video-colonoscopy, which also presents limitations such as low patient compliance, difficult medium- and short-term repetition; ineffective discrimination of anal canal diseases, and, last but not least, the cost, which is substantially higher than that of anoscopy. The Author presents the results of experimentation with digital Videoproctoscopye (Proctomedia s.r.l., Rome, Italy), performed with the aid of a bar on which is situated a separate-head digital camera, a solid light source with an optical fibre guide, and an insufflation channel. The top of the bar can be attached with a bayonet coupling to a disposable rigid proctoscope. The tool is connected to a high-resolution LCD monitor and to a high-definition digital tape with an ethernet card, allowing the surgeon to record images on an SD card. Three hundred and seventy-six digital videoproctoscopies were carried out, enabling the author to make a correct diagnosis of the anal, perianal and rectal pathologies.     

A new clinical test for radial tunnel syndrome--the Rule-of-Nine test: a cadaveric study

PURPOSE: Radial tunnel syndrome refers to pain on the lateral aspect of the forearm as a result of compression of the posterior interosseous nerve within a tunnel with specific anatomical boundaries. Diagnosis of the condition is difficult because of its close association with lateral epicondylitis, which warrants different methods of treatment. Based on a cadaveric study, a new clinical test, the Rule-of-Nine test, is proposed to improve the diagnostic accuracy in radial tunnel syndrome. The test involves constructing 9 equal squares on the anterior aspect of the forearm and noting those squares where tenderness can be elicited. METHODS: 19 upper limbs were dissected to delineate the path of the posterior interosseous nerve through the radial tunnel, and the relationship of the path of the nerve with the 9 squares. RESULTS: A consistent mapping of the posterior interosseous nerve to the lateral column of 3 squares was observed. CONCLUSION: The Rule-of-Nine test is proposed as a reliable method of diagnosing radial tunnel syndrome.     

Comparison of acromioaxillosuprasternal notch index (a new test) with modified Mallampati test in predicting difficult visualization of larynx

BackgroundWe aimed to compare the efficacy of a new bedside screening test named acromioaxillosuprasternal notch index (AASI) with modified Mallampati (MMP).MethodsA total of 603 adult patients, who were candidates for tracheal intubation in elective surgery, were enrolled in this prospective study. Preoperative airway assessment was carried out with AASI and MMP. The new AASI score is calculated based on the following measurements: (1) using a ruler, a vertical line is drawn from the top of the acromion process to the superior border of the axilla at the pectoralis major muscle (line A); (2) a second line is drawn perpendicular to line A from the suprasternal notch (line B); and (3) the portion of line A that lies above the point where line B intersects it is line C. AASI is calculated by dividing the length of line C by that of line A (AASI = C/A). After induction of anesthesia, the laryngeal view was recorded according to the Cormack–Lehane grading system. Receiver operating characteristic curve analysis was employed to compare between AASI and MMP.ResultsDifficult visualization of larynx (DVL, Cormack–Lehane III and IV) was observed in 38 (6.3%) patients. The best cutoff point for DVL was defined at AASI > 0.49. AASI had a lower false negative rate and higher predictive values (sensitivity, positive predictive value, and accuracy) in comparison with MMP.ConclusionAASI was associated with higher predictive values than MMP and could be used for estimation of DVL.