Ultrastructure of the normal human organ of Corti. New anatomical findings in surgical specimens

Conclusion A thorough scanning electron microscopy (SEM) investigation of immediately fixed human adult cochleae obtained during surgery for petro-clival meningiomas conveyed new information about morphology.

Objective To investigate the ultrastructure of human adult cochleae using SEM.

Material and methods Two human cochleae were decalcified, fixed with glutaraldehyde and osmium and prepared for SEM.

Results The excellently preserved morphology showed the pathways of nerve fibres through the organ of Corti. Undulating lateral cell membranes of Hensen and Claudius cells created an enlarged surface that may be important for homoeostasis. The distal attachment of the tectorial membrane to the reticular lamina was present in the shape of a marginal net, which was extended through marginal pillars. Stereocilia imprints extended as far as the distal end of the marginal pillars. The presence of an irregularly distributed fourth row of outer hair cells attached to the marginal pillars raises questions about differences in the excitation of the last row of outer hair cells as a result of differences in the composition of the tectorial membrane.     

嗅球、嗅束的显微解剖学研究

目的详尽了解嗅球、嗅束、嗅三角区的显微解剖学特点,为相关手术入路提供解剖学基础。方法 15例(30侧)颅骨干性标本,进行筛板区域的观察和测量。15例(30侧)头颅湿性标本,对嗅球、嗅束及嗅三角进行显微解剖学观察和拍照。结果筛孔分布在前颅底中线两侧,长(19.77±1.23)mm;中点处宽(3.15±0.45)mm的蝶形凹陷内;鼻甲侧筛孔数目明显多于鼻中隔侧(P<0.01),鸡冠两侧筛孔相对密集。嗅丝由嗅鞘包裹形成嗅神经,嗅神经于嗅窝内汇集形成嗅球。嗅球后极延续为嗅束,嗅束走形在前颅窝底直回与内侧眶回之间,并成为两者的分界,前部扁平,后部横断面呈三角形,前部相对后部较宽。嗅束于前穿质前部延续为嗅三角,以内侧嗅纹、外侧嗅纹分别进入脑实质而终。结论熟悉嗅丝、嗅球、嗅束及嗅三角的显微解剖特点,有利于提高相关手术入路中嗅觉通路的保护及嗅觉功能的保留,从而提高手术成功率,减少并发症的发生率。     

Effects of Extracorporeal Shock Wave-Mediated Transdermal Local Anesthetic Drug Delivery on Rat Caudal Nerves

Cavitation plays a substantial role in the clinical effects of extracorporeal shock wave therapy (ESWT). It is also generally accepted as a major mechanism in sonophoresis. To identify the enhancing effect of extracorporeal shock wave-mediated transdermal drug delivery, 24 Wistar rats were randomly assigned to four groups: (i) topical application of a eutectic mixture of local anesthetics (EMLA); (ii) 1-MHz ultrasound; (iii) ESWT pre-treatment combined with EMLA application; (iv) ESWT concurrent with EMLA application on rat tails. The degree of anesthesia was assessed using the amplitude and latency of sensory nerve action potentials within 5?min after a 60-min EMLA application. The results indicated that ESWT pre-treatment and concurrent ESWT accelerated the anesthetic effects of the EMLA cream on the tail nerve (p?<?0.05). This finding might indicate that shock wave-mediated transdermal drug delivery is possible during the ESWT period.     

Effect of progressive muscular relaxation exercises versus transcutaneous electrical nerve stimulation on tension headache: A comparative study

Tension-type headache (TTH) is most frequent among all types of headaches. According to the International Headache Classification Subcommittee of the International Headache Society (2004), TTH occurs in 30–78% of the population. Progressive muscular relaxation exercises have been shown to reduce TTH, and home-based relaxation programmes can result in significant improvement in headaches. Transcutaneous electrical nerve stimulation (TENS) is a method of electrical stimulation that primarily aims to provide a degree of symptomatic pain relief by exciting sensory nerves and stimulating either the pain gate mechanisms or the opioid systems. The objective of this study was to compare between the effects of progressive muscular relaxation exercises and TENS on pain intensity and stress in people with TTH. Thirty patients with TTH were allocated to either Group A or Group B. Group A practised progressive muscular relaxation exercise, whereas Group B received TENS. In the latter group, TENS electrodes were placed bilaterally either on the head at the site of pain or on the occiput. The treatment was carried out for 15 minutes a day, for 7 days. Patients were assessed for pain intensity (Visual Analogue Scale) and level of stress (Lakaev Academic Stress Response Scale) before and after the intervention period. The results showed that progressive muscular relaxation exercises were effective in reducing pain as well as stress (p < 0.001). TENS, by contrast, reduced stress significantly (p < 0.001), but not pain (p = 0.233). Between-group analysis revealed that there was no statistically significant difference in reduction of pain between the two groups (p = 0.595), but the amount of stress reduction in Group A (p = 0.002) was significantly more than that in Group B. In conclusion, progressive muscular relaxation exercises were more effective in reducing stress level than TENS in patients with TTH. The effect on pain reduction was similar between the two treatment methods.     

Optimal freezing and thawing for the survival of periphheral nerves in severed rabbit limbs

This study aimed to investigate the optimal freezing and thawing procedures for the survival of peripheral nerves in severed rabbit limbs. Twenty New Zealand White rabbits were randomized into four groups: normal control, slow-freezing fast-thawing, slow-freezing slow-thawing, fast-freezing fast-thawing, with five animals in each group. The hind limbs of the rabbits were severed at 1 cm above the knee joint. The severed limbs were cryopreserved with various freezing and thawing procedures. The sciatic nerves were harvested and trypsinized into single nerve fibers for morphological evaluation. The cell viability of the nerve fibers was examined by staining with Calcein-AM and propidium iodide. The fluorescent intensity of the nerve fibers was measured with a laser scanning confocal microscope. The morphology of the nerve fibers in the slow-freezing fast-thawing group was very similar with that of the normal control group, with only mild demyelination. The slow-freezing fast-thawing group and slow-freezing slow-thawing group showed severely damaged nerve fibers. The fluorescent intensities of the nerve fibers was significantly different among the four groups, with a decreasing order of normal control, slow-freezing fast-thawing, slow-freezing slow-thawing, and fast-freezing fast-thawing (P < 0.05). Of the various cryopreservative procedures, slow-freezing fast thawing has the minimal effects on the survival of nerve fibers in severed rabbit limbs.     

Liposome bupivacaine in peripheral nerve blocks and epidural injections to manage postoperative pain

Solifenacin is an antimuscarinic agent, administered once daily, which has been newly approved for the treatment of overactive bladder (OAB). Solifenacin administered at 5- and 10-mg once-daily doses shows efficacy for all the symptoms of OAB in both ‘wet’ and ‘dry’ patients, including improvements in patient quality of life and satisfaction. These improvements are observed as early as week 2 of treatment and are maintained over 12-week and 1-year time periods, without being compromised by the age or gender of the patient. Solifenacin demonstrates a favourable tolerability profile, with mild dry mouth as the most common adverse event associated with its use, both at the 5- and 10-mg doses; this allows for flexibility in the dosing regimen, in which physicians can administer solifenacin 5 mg, with the option to safely increase the dose to 10 mg if necessary based on the severity of patient’s symptoms. The favourable efficacy and safety profile of solifenacin, coupled with its dose flexibility, are consistent with solifenacin being a convenient treatment option for patients with OAB.