A new airway device for small laboratory animals

There is a need for a device for improved management of the airway of small laboratory animals during general anaesthesia. This report introduces such a device, referred to here as the airway device (AD). The AD has some similarity to the laryngeal mask airway (LMA) developed for human patients, but the mask portion of the device is specifically designed for small laboratory animals. In addition, the device has an oesophageal extension and unlike the LMA does not have a cuff associated with the mask. This report also shares experience of tests of one prototype AD with six New Zealand white rabbits. The AD was used for administering isoflurane and its effectiveness was evaluated during conditions of spontaneous and controlled intermittent positive pressure ventilation. The results provide encouragement for further development of the AD for airway management of small laboratory animals.     

Airway management with the laryngeal tube in rabbits

The rabbit's oropharyngeal anatomy complicates the use of endotracheal intubation for airway management during surgical procedures. To determine if the laryngeal tube is useful for airway management in rabbits, the authors applied the device and evaluated its efficacy to ventilate the lungs. The laryngeal tube was inserted blindly and without difficulty in six healthy male New Zealand White rabbits; all of the rabbits were ventilated adequately with and without neuromuscular blockade. The authors conclude that the laryngeal tube can be used as an alternative means of airway management in rabbits.     

双管喉罩在小儿眼科手术中应用的临床研究

目的：研究双管喉罩（PLMA）在小儿眼科麻醉中应用的可行性和安全性。方法：择期小儿眼科手术患者180例,随机均分为（P组）双管喉罩组、（L组）普通喉罩组、（T组）气管插管组。记录麻醉诱导前（T0）,置入喉罩（导管）后（T1）,手术开始1分钟后（T2）,手术刺激最强（T3）,拔出喉罩（导管）前（T4）,出手术室前（T5）,的心率（HR）,平均动脉压（MAP）,脑电双频指数（BIS）值。记录手术时间、拔管时间、麻醉药用量（丙泊酚用量）、苏醒时间及拔管后不良反应（呛咳、低氧血症、喉痉挛、声音嘶哑、咽喉痛）。结果：P组、L组喉罩一次性置入成功率高于T组气管导管一次性插入成功率。P组和L组丙泊酚用量明显低于T组（P〈0.05）。与T组比较P组、L组在T1、T2、T3、T4时HR较慢,MAP较低,BIS值较高（P〈0.05）,T组血流动力学波动明显大于P组、L组。P组和L组苏醒时间明显短于T组（P〈0.05）。结论：在小儿眼科手术麻醉中,PLMA放置成功率高,血流动力学平稳,术中通气情况良好,发生反流、误吸、分泌物增多等并发症少,苏醒迅速,是一种安全有效的麻醉方法。     

The laryngeal mask airway in experimental pig anaesthesia

The pig is used as a large animal model in many research projects. Standard practice for airway maintenance under general anaesthesia is using endotracheal (ET) intubation after intravenous induction to a near surgical plane. This is a technically demanding skill, requiring the assistance of an experienced technician. A technique is required which simplifies pig anaesthesia. This study examined the feasibility and potential advantages of using the laryngeal mask airway (LMA) in 10 pigs during laparotomy under spontaneous breathing anaesthesia. The results show that the LMA can be inserted rapidly, with minimal time for airway control by researchers relatively inexperienced in anaesthesia and is associated with few complications. By removing the need for intravenous induction, an entire step in the anaesthetic process is removed. The LMA designed for humans fits well in the pig hypopharynx; all pigs could be manually ventilated with no detectable gas leak. Although the pigs in this study were spontaneously breathing it is proposed that the LMA should be further investigated in studies of artificially ventilated pigs.     

The rabbit as an animal model for haemoperfusion: surgical preparation and use

In this paper the authors describe the surgical procedure to prepare rabbits for haemoperfusion experiments. The carotid artery and jugular vein are cannulated and a simple shunt device inserted to maintain patency of the vessels over a period of time. The cannulas and shunt remain patent and free of infection for some months. Specially designed outflow and inflow extracorporeal tubing sets minimize blood volume outside the body of the rabbit. The authors also illustrate the efficacy of this system in haemoperfusion trials to remove specific antibodies. Recently a system was described to remove mercury from the bloodstream of poisoned animals. The rabbit is a useful experimental animal for this type of haemoperfusion trial.     

大鼠心脏插管留置术的探讨

目的探讨大鼠右心房插管留置术实验方法。方法20只SD大鼠进行右心房导管置入术,术后随机分为2组（导管穿弹簧正内孔组、导管穿弹簧侧边入内孔组）,每组各10只。导管在体内固定后由颈背部引出,穿过弹簧,导管另一端固定于饲养笼外的支架上,导管外接三通管等。结果24 h对两组模型进行实验观察。（1）导管穿弹簧正内孔组：只有1只导管弹簧设备未完全破坏,另9只模型的导管被咬断或拉出了出来,10只模型都不能从导管抽取血液样本。（2）导管穿弹簧侧边入内孔组：导管和弹簧设备都完好,其中9只模型都能从导管抽取血液样本。结论导管穿弹簧侧边入内孔组模型方法是成功的,有一定的推广价值。     

A dose-rate meter of visible laser radiation

To measure the laser radiation power in the experimental and clinical medicine the authors developed a compact, easily inserted in any laser medical installation power measurer. The measurer consists of the photodetector--silicon photoresistor, temperature-compensating photoresistor, operational amplifier and feeding block. The merit of the measurer is its constructive simplicity, reliability in work.     

Feasibility of the laryngeal tube airway for artificial ventilation in pigs and comparison with the laryngeal mask airway

Airway management in anesthetized pigs is known to be technically demanding, and the 'gold standard' technique of endotracheal intubation is particularly difficult to master. The authors investigated the feasibility of the laryngeal tube as an alternative technique for airway management in German Landrace pigs (n = 5). They compared this method with the laryngeal mask, which is considered to be an effective yet relatively straightforward tool for porcine airway management. One after the other, investigators attempted to establish an airway in each anesthetized, artificially ventilated pig using each device. The laryngeal tube was too short to intubate the largest pig (weighing 45 kg), and it took investigators slightly longer to insert this device compared with the laryngeal mask. With the laryngeal mask, there were several incidents of gastric insufflation. Despite these complications, all investigators were able to establish a secure airway and maintain oxygenation with the laryngeal tube, and all subjectively rated both devices as easy to use.     

Novel Vitamin and Gold-Loaded Nanofiber Facial Mask for Topical Delivery

l-ascorbic acid has been widely used in cosmetic and dermatological products because of its ability to scavenge free radicals and destroy oxidizing agents. However, it is chemically unstable and can easily be oxidized. The current cosmetic facial masks available in the market are pre-moistened, which means that the aqueous fluid content of the mask may oxidize some of the unstable active ingredients such as ascorbic acid. This work presents an anti-wrinkle nanofiber face mask containing ascorbic acid, retinoic acid, gold nanoparticles, and collagen. This novel face mask will only be wetted when applied to the skin, thus enhancing product stability. Once moistened, the content of the mask will gradually dissolve and release the active ingredients and ensure maximum skin penetration. The high surface area-to-volume ratio of the nanofiber mask will ensure maximum contact with the skin surface and help to enhance the skin permeation to restore its healthy appearance. Electrospun fiber mats may provide an attractive alternative to the commercial facial cotton masks.     

A face mask for estimation of whole body leucine turnover in unanesthetized beagle dogs

As part of a long-term study of protein and energy metabolism in Beagle dogs, a latex face mask was developed to facilitate respiratory gas collection. The mask described here is easily assembled using readily available materials and meets the following criteria: small dead air space, lightweight, readily acceptable by conscious dogs over a prolonged period of time, leakproof , and inexpensive. The mask has been successfully used with L-[1-13C] leucine to measure 13CO2 excretion rates in studies of leucine metabolism.     

Effects of Pressure Support Ventilation Mode on Emergence Time and Intra-Operative Ventilatory Function: A Randomized Controlled Trial

We tested the hypothesis that pressure-support ventilation (PSV) allows a reduction in emergence time and laryngeal mask airway (LMA) removal time after general anesthesia compared to volume-controlled mechanical ventilation (CMV). Because spontaneous breathing (SB) is often used with LMA under general anesthesia, patients were allocated randomly to three groups (CMV, SB and PSV). Thirty-six consecutive ASA I–II patients scheduled for knee arthroscopic surgery under general anesthesia with a LMA and breathing throughout the ventilator circuit were included. Hemodynamic and ventilatory variables were recorded before and 10-min after general anesthesia-induction, at the surgical incision, at the end of anaesthetic drugs infusion and when the patient was totally awake (which defines emergence time). LMA removal time, drug consumption were recorded at the end of the surgical procedure. Leak fraction around the LMA was also evaluated. LMA removal time was significantly higher in the CMV-group (18±6 min) compared to both SB (8±4 min) and PSV (7±4 min, P<0.05) groups as well as for emergence time: CMV-group (32±12 min), SB (17±7 min) and PSV (13±6 min, P<0.05) groups. Total propofol consumption was significantly lower in the PSV-group (610±180 mg) than in both CMV (852±330 mg) and SB (734±246 mg, P<0.05) groups. Air leaks around the LMA was significantly higher in the CMV-group than in the SB and PSV groups (16% vs 3% and 7%, all P<0.05). In conclusion, in knee arthroscopic surgery, in comparison to CMV, PSV use during general anesthesia in unparalyzed patients decreases LMA removal time, propofol consumption and leaks around LMA while improving ventilatory variables without adverse effects.

Trial Registration

Controlled-Trials.com ISRCTN17382426     

丙泊酚联合瑞芬太尼靶控输注在小儿短小手术中的效果分析

目的:探讨不同浓度丙泊酚联合瑞芬太尼靶控输注喉罩麻醉在小儿短小手术中的临床效果。方法:127例采用小儿短小手术治疗的患儿按丙泊酚给药目标浓度分为A组(2 ng/mL)、B组(3 ng/mL)和C组(4 ng/mL),分别与瑞芬太尼2 ng/mL联合应用靶控输注,行喉罩置入,失败则逐次增加瑞芬太尼剂量0.5 ng/mL直至成功置入。将各组成功率最高时浓度下的患儿分为A1、B1和C1,比较三个亚组不良反应发生情况、以及各时段HR、BIS值和MAP。结果:A组、B组和C组患儿中分别在3 ng/mL、2.5 ng/mL和2 ng/mL时置入成功率最高,满意/可接受比也最高,与其它浓度比较差异有统计学意义(P0.05)。B1组满意/可接受比值高于A1组和C1组,差异有统计学意义(x2=5.189,x2=7.031,P0.05)。不良反应发生率A1组最高,其次是C1组,与B1组比较差异均有统计学意义(P0.05)。组内行方差分析发现,A1组和C1组有较大波动,差异有统计学意义(P0.05),而B1组总体平稳,差异无统计学意义(P0.05)。结论:2.5 ng/mL瑞芬太尼与3 ng/mL丙泊酚靶控输注时喉罩麻醉在小儿短小手术中的应用效果最好,各临床指标较为平稳,不良反应发生率低。     

The proximal femoral nail antirotation (PFNA) in the treatment of proximal femoral fractures

Proximal femoral fractures, especially in elderly persons with osteoporosis, present a challenge for the traumatologist. While the dynamic hip screw (DHS) became the implant of choice for the treatment of stable fractures, the ideal implant for the treatment of unstable fractures remains an issue. In our experience, Proximal Femoral Nail Antirotation (PFNA) is an excellent device for osteosynthesis as it can be easily inserted, it provides angular and rotational stability and allows early weight bearing on the affected limb. Between February 2007 and August 2009, 76 patients underwent the PFNA fixation for proximal femoral fractures (15 men and 61 women). Forty seven fractures were pertrochanteric, 14 subtrochanteric, 2 pathological and 5 ipsilateral trochanteric and diaphyseal fractures whereas in 8 cases the PFNA was used in reosteosynthesis. The mean age of patients was 73.4 years (range 22-91 years). The fractures were reduced on a traction table and the implant was inserted using minimally invasive technique. Four patients developed superficial postoperative wound infection. No cases of implant breakage have been recorded; there was one cut-out; delayed union was noted in three patients. The majority of patients regained their pre-injury mobility status. The PFNA is an excellent implant for stabilisation of both trochanteric and complex combination fractures as well as an exceptional device for reosteosynthesis. It is easily inserted with few intra- and postoperative complications and allows early weight bearing on the affected limb as well as quicker rehabilitation of patients.     

创新型单手操作新生儿复苏器的研制

该复苏器操作简便、安全。只要把面罩盖住新生儿口鼻,用一只手即可对手泵吸球进行加压给氧。加压过高时能排余气并发声报警,避免发生气胸,提高抢救效果。另外,该手泵吸球可一物两用,按瘪后将长嘴放人新生儿口内或鼻孔口,放松时可吸羊水等黏液。节约原材料,降低成本,大有利于新生儿窒息复苏的推广普及。     

Skull expansion in experimental craniosynostosis

Bilateral coronal suture immobilization was performed in 9-day-old rabbits to simulate the brachycephaly deformity characteristic of coronal synostosis. Growth abnormalities were documented by serial radiographic cephalometry. A "corrective" linear craniectomy procedure was performed on the rabbits with an immobilized coronal suture at 60 days of age. The degree of amelioration of the induced abnormalities by the surgery in these animals was compared with a similar group of animals that had the same surgery plus supplemental implantation of a spring expansion device at the coronal suture craniectomy site. The mean marker separation at the coronal suture was significantly greater (5.61 mm +/- 0.52 SE versus 2.53 mm +/- 0.38 SE; p less than 0.05) following spring expander implantation than with linear craniectomy alone. Similarly, induced anterior cranial base shortening and distortion of craniofacial cephalometrics were more significantly improved by the additional use of the spring expansion device.     

Leaf thickness controls variation in leaf mass per area (LMA) among grazing-adapted grasses in Serengeti

Leaf mass per area (LMA) is a primary plant functional trait that represents the cost of constructing a leaf. Ultimately, plants modify LMA by altering leaf thickness (LT), leaf dry matter content (LDMC), or both. While LMA can be modified through both of these constituents, studies of LMA have found that there is variation in whether LT or LDMC changes are responsible for LMA—and the relationships change depending on the species or functional groups being compared. In this study, we used a phylogenetic framework to determine that evolutionary shifts in LMA are driven by LT, and not LDMC, among 45 Serengeti grass species. We considered two alternative hypotheses that could result in evolutionary correlation of LMA on LT but not LDMC: either (1) LT is more labile than LDMC—and is therefore a less costly means to change LMA or (2) LDMC is tightly coupled to a different dimension of leaf variation (e.g., leaf hydraulics), leaving LT as the source of variation in LMA. LT was not more labile than LDMC, leading us to conclude that the evolution of LMA has been shaped by LT because LDMC is responding to other demands on leaf physiology. We speculate that leaf hydraulics provide this constraint on LDMC. The decoupling of LDMC from LT may allow plants to better optimize resource allocation in ecosystems where gradients in light competition, herbivory, and aridity place competing demands on leaf economics.     

Implantable device for intravenous drug delivery in the rat.

The experimental design of studies using small laboratory animals may require repeated venous access for the application of drugs or diagnostics. An appropriate device should provide quick intravenous access without causing severe handling stress to the animals or the necessity of anaesthesia. In addition, the system should be suitable for repeated injections over several weeks. A silicone catheter is connected to an intravenous indwelling cannula with fixation wings. A closure stopper with injection port completes this system. The device is fixed subcutaneously on the back of the animal and the catheter is inserted into the jugular vein. The device is easily and quickly assembled and is more economic than commercial systems. It is easily implanted and allows repeated intravenous injections for several weeks without anaesthesia or restraint of the animals. The method allows repeated intravenous drug delivery over a couple of weeks in small animals.     

Application of protein lysate microarrays to molecular marker verification and quantification

This study presents the development and application of protein lysate microarray (LMA) technology for verification of presence and quantification of human tissue samples for protein biomarkers. Sub-picogram range sensitivity has been achieved on LMA using a non-enzymatic protein detection methodology. Results from a set of quality control experiments are presented and demonstrate the high sensitivity and reproducibility of the LMA methodology. The optimized LMA methodology has been applied for verification of the presence and quantification of disease markers for atherosclerosis. LMA were used to measure lipoprotein [a] and apolipoprotein B100 in 52 carotid endarterectomy samples. The data generated by LMA were validated by ELISA using the same protein lysates. The correlations of protein amounts estimated by LMA and ELISA were highly significant, with r² ≥ 0.98 (p ≤ 0.001) for lipoprotein [a] and with r² ≥ 0.94 (p ≤ 0.001) for apolipoprotein B100. This is the first report to compare data generated using proteins microarrays with ELISA, a standard technology for the verification of the presence of protein biomarkers. The sensitivity, reproducibility, and high-throughput quality of LMA technology make it a potentially powerful technology for profiling disease specific protein markers in clinical samples.     

An ultrastructural study of the dorsal lingual epithelium of the crab-eating frog,Rana cancrivora

The amphibian tongue contains two types of papilla which are believed to function in gustation and in the secretion of salivary fluid. Scanning electron microscopy reveals that columnar, filiform papillae are compactly distributed over nearly the entire dorsal surface of the tongue of the frog, Rana cancrivora, and fungiform papillae are scattered among the filiform papillae. Microridges and microvilli are distributed on the epithelial cell surface of the extensive area of the filiform papillae. Light microscopy shows that the apex of each filiform papilla is composed of stratified columnar and/or cuboidal epithelium and its base is composed of simple columnar epithelium. Transmission electron microscopy reveals that most of the epithelium of the filiform papillae is composed of cells that contain numerous round electron-dense granules 1–3 μm in diameter. Cellular interdigitation is well developed between adjacent cells. On the free-surface of epithelial cells, microridges or microvilli are frequently seen. Between these granular cells, a small number of ciliated cells, mitochondria-rich cells and electron-lucent cells are inserted. In some cases, electron-dense granules are present in the ciliated cells. At higher magnification, the electron-dense granules appear to be covered with patterns of spots and tubules. Overall, the morphology and ultrastructure of the lingual epithelium of the three species of Rana that have been studied are quite similar, but they can be easily distinguished from those of Bufo japonicus. Therefore, it appears that lingual morphology is phylogenetically constrained among members of the predominantly freshwater genus Rana to produce uniformity of papillary structure and this morphology persists in Rana cancrivora despite the distinct saline environment in which it lives. © 1993 Wiley-Liss, Inc.     

Contribution of supraglottal mechanoreceptor afferents to respiratory-related evoked potentials in humans.

We used the global field power (GFP) to estimate the magnitude and timing of activation of the somatosensory cortex by respiratory mechanoreceptor afferents in normal humans in response to brief, negative oral pressure pulses applied at the onset of inspiration. We compared responses before (test) and after insertion of a laryngeal mask airway (LMA) that prevented supraglottal airway receptors from sensing the applied stimulus. Evoked potential responses without supraglottic stimulation were smaller, with delayed or missing features, than those with all receptors stimulated. Supraglottic receptors contribute about one-half of the GFP summed over the 100 ms poststimulus, and subglottal receptors, including those in the larynx, provide a GFP response approximately 38% above baseline. The most obvious difference between test and LMA responses occurred at 55 ms on average, when the LMA GFP lacked activation features seen in the test condition. We conclude that mechanoreceptors above the larynx are responsible for a major portion of the midlatency afferent information arriving at the somatosensory cortex in response to applied pressure pulses.