Simplification in locating and dissecting the levator muscle of the upper eyelid in surgery for ptosis

BACKGROUND: While repairing eyelid ptosis by aponeurotic resection by anterior approach, the risk of damaging the levator complex and the conjunctiva is significant. In order to simplify the dissection between Müller's muscle and the underneath conjunctiva, we use a modification of the usual surgical technique. METHODS: Before the skin incision, the eversion of the upper eyelid allows to dissect the conjunctiva from the Müller's muscle under direct visual control, starting from the upper tarsal margin. A silicone band is then passed through the so created horizontal subconjunctival tunnel. The upper eyelid can be physiologically replaced, and the levator muscle aponeurosis exposed. The two ends of the band are then pulled on surface through two lateral incision performed close to the upper tarsal edge. Now the band plays the role of a useful landmark: every tissue above the band is levator complex; when stretched downwards, it points the upper edge of the tarsal plate. We operated by this technique 24 eyes, affected of acquired or congenital ptosis. Fourteen eyelids had already undergone ptosis surgery elsewhere. RESULTS: We achieved good-to-excellent results in all cases, without any important postoperative complications. CONCLUSIONS: The proposed manoeuvre makes easier the dissection of the inner aspect of the levator complex, because of the material control. Therefore it minimises the tissue trauma and the postoperative complications, particularly in complicated cases characterised by scarring and fibrosis.     

Traumatic myositis ossificans of the levator scapulae muscle

The Chou-Fasman method has been widely used for predicting protein secondary structure. It is based on knowledge of the potential of amino acid residues to form alpha-helical or beta-sheet regions in proteins. Our main interest in this study was to examine the reliability of these Chou-Fasman parameters. We calculated the Chou-Fasman parameters, with 95% confidence limits, of 144 non-homologous proteins consisting of 155 chains, and a total of 33 118 amino acid residues. All of the protein chains used were X-ray structures known at a resolution of at least 2.5 A. We compared the results of our calculations with those previously done by Chou and Fasman. Our results show that Chou and Fasman classified four amino acid residues wrongly in alpha-helical regions and one in a beta-sheet region. This is so, because the confidence limits we calculated did not include the values determined by Chou and Fasman. Moreover, the confidence limit calculations contradict most of the Chou-Fasman classification of amino acid residues.     

Difficulties with hydroxyapatite orbital implants in two patients with dysfunctional levator/superior rectus muscle complex

OBJECTIVE: To study the effect of foreign retinoblastoma (Rb) gene mediated by recombinant adenovirus vector on vascular smooth muscle cell (SMC) and the possibility by using Rb gene for gene therapy of atherosclerosis and artery restenosis. METHODS: Rb gene recombinant adenovirus vector was constructed to transfect into rabbits' aortic SMC in vitro. The efficiency of transfection and expression was detected by biochemical staining, immunocytochemical analysis and polymerase chain reaction technique. The role of Rb gene for SMC proliferation, DNA synthesis and cell cycle were observed by cell counting. 3H-incorporation and cytometer respectively. RESULTS: Adenovirus vector transfered the Rb gene into SMC effectively. The expression of Rb gene restricted the proliferation of SMC, decreased the DNA synthesis and plaaied a role in the cell cycle. CONCLUSION: Rb gene mediated by adenovirus can be used to treat atherosclerosis.     

Optical isometric force transducer for measurement of rat skeletal muscle contraction in the NMR spectrometer

Chronic hematomas are a common problem during infancy and usually occur as the consequence of trauma. They tend to enlarge and are often managed successfully with repeated subdural taps. In patients with collections that fail to respond to percutaneous drainage, the choice of operative management, including burr hole evacuation, shunting, or craniotomy, remains controversial. A new technique, called endoscopic washout, was successfully used in 7 children under the age of 2 years who presented with irritability, vomiting, seizures, and rapid head growth. Preoperative computerized tomography (CT) scans demonstrated enlarging, bilateral, chronic subdural collections; these failed to respond to repeated percutaneous taps over 10 days. With the patient positioned supine, bilateral linear incisions were made anterior to the coronal suture in the midpupillary lines and burr holes were placed. After the dura and outer membrane were opened and coagulated with bipolar cautery, a 4-mm steerable fiberscope was introduced into the subdural space to visualize the collections, evacuate any residual clot, and continuously irrigate the space with lactated Ringer's solution warmed to physiologic temperature. No bridging vessels or synechiae were violated; nitrous oxide and hyperventilation were discontinued before removing the fiberscope. The subdural space was irrigated again prior to closure. At follow-up (range 18 months to 8 years), CT scans showed reexpansion of the brain and no reaccumulation of the hematomas. We conclude that the endoscopic washout is a safe, uncomplicated treatment for chronic subdural hematomas in infants; is more effective than treatment with conventional burr holes alone, and eliminates the need for shunting or craniotomy.     

Shortening of Müller''s muscle for the cure of sympathetic ptosis

The procedure of shortening of Müller's muscle was performed on 23 eyes of 21 patients with sympathetic ptosis. All the patients obtained satisfactory results. The patient selection and the operation techniques were described. The pathogenesis of sympathetic ptosis and the physiological function of the Müller muscle were discussed. The authors believe that shortening of Müller's muscle is the best procedure for sympathetic ptosis.     

Ipsilateral omovertebral bones in the levator scapulae muscle and the rhomboid muscle in a Sprengel deformity: case report

Two cases of successful angioplasty of bifurcational left anterior descending and diagonal lesions treated with a new side branch accessible Jomed stent in the LAD are discussed. A balloon dilatation of the side branch using kissing balloon technique in the first case and stenting the side branch followed by kissing balloon dilatation in the second case are described.     

Evaluation of respiratory muscle strength in patients with interstitial lung changes based on simultaneous measurement of esophageal and mouth pressure

A well know good relation between nasal and oesophageal inspiratory pressures exists in healthy and in COPD patients "sniff manoeuvres. Similar results are obtained using "gasp" maneuvers. The aim of the study was to appreciate the usefulness of "gasp" for evaluation of inspiratory muscles strength in ILD patients. 18 ILD patients were examined: group A consisted of 9 pts (8M+IF) aged 35 +/- 8.6 yrs, with static compliance > 70% pred. (mean 98.6 +/- 16.3), group B consisted of 9 pts (6M + 3F) (aged 52 +/- 13.0) with static compliance < 70% pred. (mean 37.2 +/- 12.0), Pmo and Poe (Milic-Emili method) were measured simultaneously during breathing with Pflex device (1.7 mm diameter). Results were stored in a computer for further analysis. In all patients spirometry, plethysmography and maximal inspiratory (MIP) and maximal expiratory (MEP) pressure measurements were performed. Poe and Pmo in group A were nearly the same (8.16 +/- 1.82 vs. 8.35 +/- 2.74 kPa), but in the group B Pmo was lower than Poe (4.81 +/- 1.59 vs. 6.19 +/- 2.03 kPa; p < 0.0005). We conclude that "gasp" - Pmo is a useful method for inspiratory muscle strength measurement only in ILD patients with normal static compliance but in ILD patients with decreased compliance "gasp" - Poe measurement in necessary.     

Pin force measurement in a halo-vest orthosis, in vivo

Salmon calcitonin (sCT) is an example of one of the many bioactive peptides that require amidation of the carboxy terminus for full potency. We describe a method for the production of amidated sCT in the mammary gland of transgenic rabbits. Expression of a fusion protein comprising human alpha lactalbumin joined by an enterokinase cleavable linker to sCT was directed to the mammary gland under the control of the ovine beta lactoglobulin promoter. C-terminal amidation in vivo was achieved by extending the sCT by a single glycine residue that provides a substrate for endogenous amidating activity in the mammary gland. Full characterization of the released sCT demonstrated it to be equivalent to synthetic standard in terms of structure, purity, and potency.     

Phase transition in force during ramp stretches of skeletal muscle

Active glycerinated rabbit psoas fibers were stretched at constant velocity (0.1-3.0 lengths/s) under sarcomere length control. As observed by previous investigators, force rose in two phases: an initial rapid increase over a small stretch (phase I), and a slower, more modest rise over the remainder of the stretch (phase II). The transition between the two phases occurred at a critical stretch (LC) of 7.7 +/- 0.1 nm/half-sarcomere that is independent of velocity. The force at critical stretch (PC) increased with velocity up to 1 length/s, then was constant at 3.26 +/- 0.06 times isometric force. The decay of the force response to a small step stretch was much faster during stretch than in isometric fibers. The addition of 3 mM vanadate reduced isometric tension to 0.08 +/- 0.01 times control isometric tension (P0), but only reduced PC to 0.82 +/- 0.06 times P0, demonstrating that prepowerstroke states contribute to force rise during stretch. The data can be explained by a model in which actin-attached cross-bridges in a prepowerstroke state are stretched into regions of high force and detach very rapidly when stretched beyond this region. The prepowerstroke state acts as a mechanical rectifier, producing large forces during stretch but small forces during shortening.     

Protective effect of hypothermia on contractile force in skeletal muscle

The clinical success of limb replantation and tissue transfer is partly dependent on the duration of ischemia experienced by the amputated part. This study focused primarily on the damage that occurs during this ischemic period. An experimental system was implemented that allowed the observation of contractile function in totally isolated skeletal muscle after ischemia. Contractile function was selected as an indicator of ischemic damage because normal function is the ultimate goal of replantation. All experiments were performed on the rat extensor digitorum longus. The muscles were subjected to ischemic periods of 1.5, 3.0, and 5.0 hours and were stored in either a hypothermic (4 degrees C) or a room-temperature (23 degrees C) environment during the ischemic interval. After the ischemic period, all muscles were transferred to a tissue bath and were subjected to contractility testing, followed by fatigue testing. In both groups, muscle function decreased as the ischemic interval was increased. A significant difference in function between the normal control and the muscles of both ischemic groups implied that ischemic injury had occurred in the hypothermic and room-temperature muscles, even with the relatively short 1.5-hour ischemic interval. After each ischemic interval however, the hypothermic muscles produced significantly greater contractile force than the room-temperature muscles in both the contractility and the fatigue tests. After 1.5 hours of ischemia, the contractile force in the hypothermic group was about three times as great as that observed in the room-temperature group. These results indicated that muscle function after a period of totally isolated ischemia is protected by hypothermic preservation. They also support the advisability of storage of amputated parts and free muscle flaps in hypothermic environments before replantation even after relatively brief intervals of ischemia.     

升力测量技术在减摇鳍控制系统中的应用

基于升力反馈控制减摇鳍系统,分析升力测量原理及所存在的非线性特性,并在升力控制减摇鳍伺服系统中采用升力/鳍角综合控制减摇鳍控制方法,修正升力反馈信号的检测问题.构建基于小波降噪的数据融合模型,该模型综合升力、鳍角传感器不同频带信息,消除信息之间的冗余和矛盾,利用信息之间的互补来获得对升力信号相对完整一致的描述.仿真结果表明,应用数据融合模型的控制系统在各种海况下均可达到良好平稳的减摇效果.     

Evaluation of continuous measurement of cardiac output with thermodilution in critical patients

Pregnant women with inflammatory bowel disease and their physicians should be aware of factors that may affect the outcome of the pregnancy. Proper patient education, along with a physician team approach, usually ensure completion of an uneventful pregnancy.     

Modified adjustable technique to anchor the levator muscle to the flap used in total upper eyelid reconstruction

Lipomatous pseudohypertrophy of the pancreas was found at autopsy in a 52-year-old Japanese woman with cirrhosis due to chronic hepatitis B. Clinically, there were no clear symptoms of pancreatic insufficiency during the entire course. Marked atrophy and fat deposition of the pancreas had already been detected by computed tomography (CT) at least 6 years before her death. She died of hepatic failure due to decompensated cirrhosis. Autopsy revealed uniform enlargement of the pancreas due to massive fat replacement (lipomatous pseudohypertrophy): the exocrine glandular elements showed marked atrophy and loss, while the islets of Langerhans were preserved. Although the etiology and pathogenesis of lipomatous pseudohypertrophy is still unclear, this case suggests that this condition is causally related to chronic hepatitis B or other chronic advanced hepatic lesions.     

The effect of keyboard keyswitch make force on applied force and finger flexor muscle activity

The design of the force-displacement characteristics or 'feel' of keyboard keyswitches has been guided by preference and performance data; there has been very little information on how switch 'feel' alters muscle activity or applied force. This is a laboratory-based repeated measures design experiment to evaluate the effect of computer keyboard keyswitch design on applied finger force and muscle activity during a typing task. Ten experienced typists typed on three keyboards which differed in keyswitch make force (0.34, 0.47 and 1.02 N) while applied fingertip force and finger flexor electromyograms were recorded. The keyboard testing order was randomized and subjects typed on each keyboard for three trials, while data was collected for a minimum of 80 keystrokes per trial. No differences in applied fingertip force or finger flexor EMG were observed during typing on keyboards with switch make force of 0.34 or 0.47 N. However, applied fingertip force increased by approximately 40% (p < 0.05) and EMG activity increased by approximately 20% (p < 0.05) when the keyswitch make force was increased from 0.47 to 1.02 N. These results suggest that, in order to minimize the biomechanical loads to forearm tendons and muscles of keyboard users, keyswitches with a make force of 0.47 N or less should be considered over switches with a make force of 1.02 N.     

拉伸试验中测量不确定度的评定

根据实验室认可要求,对拉伸试验测量不确定度的评定过程和基本方法及试样形状、尺寸、试验人员、尺寸测量器具、试验机的影响因素做了简单的讨论.     

Relationship between sarcomere length and active force in rabbit papillary muscle

Isometric peak twitch force (stimulation frequency 0.5/s; 29.5-30.5 degrees C) was correlated with sarcomere length in isolated papillary muscles of the rabbit. Sarcomere length was measured from photographic recordings (1.5 ms exposure time) performed at rest between contractions and at the time of isometric peak twitch force. The sarcomere length at rest was found to be relatively uniform throughout the preparation and to be linearly related to the overall muscle length within the range Lmax-0.85Lmax. The distribution of sarcomere lengths increased considerably as the muscle went from rest to activity. Studies of surface markers showed different degrees of shortening (or elongation) of individual segments along the length of the preparation. The mean resting sarcomere length at Lmax (the optimum muscle length for force production) was 2.44 +/- 0.01 micron (grand mean +/- S.E., 7 muscles). The means active sarcomere length at Lmax was 2.29 +/- 0.04 micron. Active force declined steeply as the muscle length was reduced below Lmax. At a resting sarcomere length of 2.0 micron, active force was approximately 1/3 of the maximum. The observed differences between the length-tension relat-onships in myocardium (twitch responses) and skeletal muscle (tetanic contractions) are discussed on the basis of a length dependency of the activation process in cardiac muscle.     

Maximal isometric force and muscle cross-sectional area of the forearm in fencers

The maximal isometric force (MIF) of a muscle is directly related to its cross-sectional area (CSA). Strength training produces an increase in muscular force while muscular hypertrophy becomes appreciable at a later time; in asymmetric sports, training causes significant increases in force and muscular mass of the dominant limb of the athlete. The aim of this study was to analyse the differences in muscular force and trophism between the dominant and non-dominant forearms in fencers and in controls. The data of 17 male distance runners (age 21.4 +/- 2.4 years, body mass 74.0 +/- 5.0 kg, height 180 +/- 6 cm) were compared with those of 58 male fencers (age 23.0 +/- 6.7 years, body mass 71.9 +/- 9.3 kg, height 178 +/- 7 cm) drawn from the ranking lists of the National Fencing Committee. They trained for a mean of 11.4 +/- 6.0 (range 2-36) years, commencing at 10.7 +/- 4.5 years of age. Cross-sectional area (muscle plus bone) was estimated in the dominant and non-dominant forearm using a simplified anthropometric method. Maximal isometric force was determined using a mechanical handgrip dynamometer. The differences in CSA and isometric force between the two limbs and between fencers and controls were tested using paired and unpaired Student's t-tests, respectively. Significant differences in CSA and maximal force were observed between the dominant and non-dominant forearm in fencers (both P < 0.001) and in controls (P < 0.005 and P < 0.001, respectively). The fencers showed a greater CSA (P < 0.001) and force (P < 0.001) in the dominant forearm compared with the control group. Furthermore, the differences between the dominant and non-dominant limb of the fencers were significantly greater than the differences between the dominant and non-dominant limb of the controls (P < 0.001 for CSA and P < 0.05 for force). No significant differences in stress ratio (force/CSA) were obtained in either group.(ABSTRACT TRUNCATED AT 250 WORDS)