Principles for reconstruction of traumatic ear defects

Summary Traumatic defects of the auricle are quite common. The eventual success of the repair is considerably influenced by the initial treatment. The different parts of the auricle require different approaches. This paper presents our methods for repairing damage to the cartilaginous frame using autologous ear cartilage grafts, and local flaps from the mastoid region to cover soft tissue defects.     

用荧光探剂DPH研究家蝇线粒体膜脂流动性

本文探讨了用ＤＰＨ作为荧光探剂，研究家蝇飞翔肌线粒体膜脂流动性的方法。实验表明：ＤＰＨ确是用来研究家蝇生物膜流动性的有效探剂。同时，初步观察了不同杀虫剂对ＤＰＨ与线粒体膜结合后荧光强度的影响。其中氯菊酯和倍硫磷、马拉硫磷、敌百虫、氧化乐果，可使ＤＰＨ探剂与线粒体膜结合后的荧光相对强度增加；而氰戊菊酯、氯氰菊酯，溴氰菊酯及辛硫磷、乙酰甲胺磷，则可使荧光强度减弱。     

Transfer of lumbosacral load to iliac bones and legs Part 1: Biomechanics of self-bracing of the sacroiliac joints and its significance for treatment and exercise

This study deals primarily with the stability of the base of the spine. The sacroiliac joints are vulnerable to shear loading on account of their predominantly flat surfaces. This raises the question of what mechanisms are brought into action to prevent dislocation of the sacroiliac joints when they are loaded by the weight of the upper part of the body and by trunk muscle forces. First a model is introduced to compare load transfer in joints with spherical and with flat joint surfaces. Next we consider a biomechanical model for the equilibrium of the sacrum under load, describing a self-bracing effect that protects the sacroiliac joints against shear according to ‘the sacroiliac joint compression theory’, which has been demonstrated in vitro. The model shows joint stability by the application of bending moments and the configuration of the pelvic arch. The model includes a large number of muscles (e.g. the gluteus maximus and piriformis muscles), ligaments (e.g. the sacrotuberous, sacrospinal, and dorsal and interosseous sacroiliac ligaments) as well as the coarse texture and the ridges and grooves of the joint surfaces.     

Muscular performance after a 3 month progressive physical exercise program and 9 month follow-up in subjects with low back pain. A controlled study

The purpose of this study was to assess, in subjects with low back pain, the changes and their permanence in muscular performance after a 3 month progressive physical exercise program. Ninety subjects with chronic low back pain participated in the study. The study design was controlled and it was carried out in three groups: intensive training, home exercise, and control group. Isometric and dynamic muscle strength of the trunk and lower limb were measured, at the beginning of the study and after the 3 months exercise program, and then during each of the follow-up sessions. The Oswestry Index and back pain intensity were also determined. Both exercise groups received benefit from the progressive exercise program. Their muscular performance improved and their back pain intensity decreased significantly. Among the home exercise group, the Oswestry Index also changed positively. The results demonstrate that the home exercise program could be as effective as the intensive training program in increasing muscle strength, as well as decreasing back pain and functional disability among low back pain patients with mild functional limitations.     

In vivo 31P NMR studies of paraplegics' muscles activated by functional electrical stimulation

The bioenergetics of paralyzed muscles of spastic paraplegic patients under functional electrical stimulation (FES) was studied in vivo using ³¹P NMR. The protocol included rest, 3 min of induced tetanic isometric contraction through surface electrodes and 40 min of recovery. The continuous stimulation, the force recording and the ³¹P NMR measurements were sampled simultaneously inside the whole body imager. Normal values were found for the phosphorous metabolite ratios at rest. During contraction, prominent changes were detected including: a) accumulation of inorganic phosphate (P) accompanied by an unusually strong signal in the phosphomonoester (PME) region, b) phosphocreatine (PCr) decline, and c) a decrease in the intracellular pH. In the following recovery period the physiological state of the muscle was monitored and quantitated by ³¹P NMR. No metabolic and mechanical irreversible damage was detected in the paraplegics' muscles activated by FES under our experimental conditions.     

Comparative effects of ischemia and acute hypoxemia on muscle afferents from tibialis anterior in cats

Comparative effects of ischemia and acute hypoxemia (PaO₂ = 24 mm Hg) were studied in anesthetized cats on afferents from the tibialis anterior limb muscle. Metaboreceptors (groups III and IV fibers) and mechanoreceptors were identified by their activation by an intraarterial injection of lactic acid (LA) or high-frequency vibrations (HFV) applied to the extremity of the muscle tendon, respectively. Ischemia and hypoxemia exerted opposite influences on the two categories of muscle afferents: they depressed the response of mechanoreceptors to HFV, but markedly enhanced the spontaneous tonic activity of metaboreceptors. The effects of hypoxamia were delayed but slightly greater and lasted longer during the recovery period than those exerted by ischemia. The inhibitory action on mechanoreceptors exerted by a reduced oxyden supply to muscle is interpreted as a result from local acidosis. Indeed, under normoxic conditions, a LA bolus injection during the HFV test also reduced the firing rate of these receptors. © 1993 John Wiley & Sons, Inc.     

Is monoamine oxidase inhibitor induced myoclonus serotoninergically mediated?

Summary In the present study a single case observation of myoclonus during sleep-wave transition was monitored in a depressed patient treated with the monoamine oxidase inhibitor, phenelzine. The myoclonus had a rhythm of 1 c/second and lasted for two years, the duration of phenelzine treatment. Myoclonus appeared neither during wakefulness nor during sleep, but at wake-sleep-wake transitions. This switch myoclonus was associated with phasic muscle hyperactivity during REM sleep.Methysergide a 5-HT suppressor, decreased the switch myoclonus frequency and the REM muscle hyperactivity, indicating serotoninergic involvement in the mechanism of phenelzine induced myoclonus.     

Prospect for enzyme therapy in glycogenosis II variants: a study on cultured muscle cells

Summary Impairment of skeletal muscle function is the common feature of distinct clinical forms of glycogenosis type II. In the present study, muscle cultures from different patients were used to investigate the cause of clinical heterogeneity and the feasibility of enzyme replacement therapy. The activity of acid -glucosidase appears to be the primary factor in determining the extent of lysosomal glycogen storage in muscle, and thereby the clinical severity of the disease. Neutral -glucosidases do not seem influencial. Correction of the enzymatic defect was achieved in skeletal muscle cultures from patients by administration of a high-uptake form of acid -glucosidase, purified from human urine. The enzyme reaches the lysosomes, including the glycogen storage vacuoles, and the lysosomal glycogen content is reduced to control level. In normal muscle cells 20% of the total cellular glycogen pool is segregated in lysosomal compartments. This percentage is higher than in fibroblasts, which may partly explain why muscles are more prone to store glycogen. The relevance of this study for enzyme therapy is discussed.     

The depressing effect of tetracaine and ryanodine on the slow outward current correlated with that of contraction in voltage-clamped frog muscle fibres

The effects of tetracaine (10–50 M) and ryanodine (0.1–10 M) were tested on the slow outward K⁺ current (I _so) and the mechanical tension of isolated frog muscle fibres in a voltage-clamp device (double mannitol-gap) connected to a mechanoelectric transducer. In the concentration range tested, both drugs induced a simultaneous inhibition of tension and current. In all cases the effect on tension was twice that on current. The tetracaine-induced current and tension blocks were fully reversible and dose-dependent. In contrast the ryanodine effects on current and tension were not reversible and did not exhibit a dose dependence except for the delay before the onset of the response, which was shortened when the concentration was raised. Linear regression analysis of the time-dependent and dose-dependent effects of both drugs indicated a strong correlation between the decreases in tension and current. It is concluded that the slow outward current is partly under the control of the Ca²⁺ release from sarcoplasmic reticulum during contraction.