A method of endoscopic endotracheal intubation in rabbits.

Endotracheal intubation in rabbits is a formidable task and has led to the devising of a new endoscopic method. Sixty New Zealand White rabbits (2.0-3.5 kg) underwent experimental left thoracotomy requiring mechanical ventilation. After anaesthetic induction was achieved, the animal was placed in a supine position. A rigid 30 degrees endoscope was passed through a 4.5 mm endotracheal tube (ET) and then used to advance, under direct vision, through the oropharynx and vocal cords. Once passing the vocal cords, the ET was advanced into the trachea as the endoscope was withdrawn. All animals were successfully intubated within 30 s to 2 min and then ventilated. No complications or deaths occurred during or after intubation, or postoperatively. No instances of oesophageal intubation occurred. All animals survived long-term. Thirty animals underwent necropsy at 10 days and, 30 at 30 days, with no postoperative evidence of orotracheal injury. We have established a new method of endotracheal intubation in rabbits. It is reliable, effective, non-traumatic, safe, and expeditious.     

Video-assisted orotracheal intubation in mice

Orotracheal intubation in mice is a complicated technique because of the peculiar oropharyngeal anatomy and the difficulty in visualizing the laryngis aditus. Here we report a new and simple method for rapid endotracheal intubation by using a small bore, straight fibre-optic arthroscope. Under endoscope-assisted visualization of the laryngis aditus, a polyethylene cannula, inserted on a guide-wire in order to facilitate the introduction of the tip across the vocal cords, was advanced in the trachea. The success rate of intubation was 100%. We were also able to re-intubate the mice 4 and 8 weeks later without any major complications. We conclude that this method can be easily and safely used for studies where controlled pulmonary ventilation is necessary.     

Simplified rat intubation using a new oropharyngeal intubation wedge.

Our new oropharyngeal intubation wedge made from a plastic 3-ml syringe has been used successfully for the expansion of the oropharyngeal cavity and visualization of vocal cords for endotracheal intubation in the rat. All the animals we used tolerated the intubation and ventilation procedures in a series of experiments. After the proper setting of the respirator, vital signs were maintained within normal range. The postmortem examination and measurements in the upper airway confirmed that the endotracheal tube was properly sited and also demonstrated the precise size of the device that should be used. The main advantages of this method include low cost, simplicity, and reliability. Furthermore, because no expensive, elaborate, difficult-to-operate, or hard-to-get special equipment is needed, this technique can be used in every laboratory.     

A technique for retrograde intubation in mice

Endrotracheal intubation is critical for some experimental studies in mice, but the animals' small size makes the procedure difficult. The authors describe a new, easily learned retrograde intubation method using angioplasty guide wire. They twice intubated anesthetized mice successfully with no airway complications caused by puncture of the trachea.     

大鼠气管插管方法学概述

由于大鼠呼吸频率较快、口腔狭小、声门较高,医学实验中气管内插管操作具有较多困难,多年来很多学者对大鼠气管内插管方法进行了大量研究。本文主要对大鼠气管内插管时动物和气管导管的选择、麻醉方式、插管的体位以及各种插管工具和方法等作一简要的综述。     

麻醉大鼠左心室插管新方法

目的：探索在0．014’’经皮冠状动脉（PTCA）指引导丝引导下行大鼠左心室插管的方法。方法：30只Wistar大鼠,先后在PTCA导丝引导经右侧颈外动脉,左侧颈外动脉插管至左心室并行血流动力学测定：结果：30只大鼠成功完成一次左心室重复插管,27只大鼠完成重复插管：结论：PTCA指引导丝引导下左心室插管安全并可重复操作。     

A novel and simple method for endotracheal intubation of mice

Endotracheal intubation in mice is necessary for experiments involving intratracheal instillation of various substances, repeated pulmonary function assessments and mechanical ventilation. Previously described methods for endotracheal intubation in mice require the use of injection anaesthesia to immobilize the animal during the intubation procedure or the use of a volatile anaesthetic prior to intubation for immobilization. With these methods, the control of anaesthetic depth during the intubation procedure is absent. We describe a method for simple and rapid intratracheal intubation in mice for mechanical ventilation, using a self-built plastic support to facilitate the intubation procedure. General anaesthesia is maintained by means of inhalation through a non-rebreathing circuit connected to the plastic support. This set-up gives the operator control of anaesthetic depth and sufficient time to perform the intubation procedure. A purpose-made laryngoscopic blade is used to facilitate the intubation tube entering the trachea. The blade of the purpose-made laryngoscope is constructed as a retraction guide and is curved for easy handling. Under direct vision, the epiglottis is gently lifted by the laryngoscopic blade while the intubation tube is pushed into the trachea. Following this novel intubation technique, we were able to mechanically ventilate mice for at least 2 h without severely disturbing blood gases. Histological evaluation of the lungs and microscopic evaluation of the trachea and larynx showed no signs of trauma related to the intubation technique or mechanical ventilation.     

Fibreoptic endoscopic palliative intubation of inoperable oesophagogastric neoplasms.

Palliative intubation for inoperable malignant strictures at the cardia was done on 16 occasions in 13 patients using fiberoptic endoscopy. Preliminary dilatation was performed, and the Celestin tube was mounted on an introducer and passed over a guide wire inserted with a fiberoptic endoscope. Only one death resulted from the procedure and all the 12 patients who left hospital were swallowing satisfactorily on discharge. The method provided a simple and relatively safe means of relieving dysphagia and improving nutrition.     

A Simple Guide Screw Method for Intracranial Xenograft Studies in Mice

The grafting of human tumor cells into the brain of immunosuppressed mice is an established method for the study of brain cancers including glioblastoma (glioma) and medulloblastoma. The widely used stereotactic approach only allows for the injection of a single animal at a time, is labor intensive and requires highly specialized equipment. The guide screw method, initially developed by Lal et al.,¹ was developed to eliminate cumbersome stereotactic procedures. We now describe a modified guide screw approach that is rapid and exceptionally safe; both of which are critical ethical considerations. Notably, our procedure now incorporates an infusion pump that allows up to 10 animals to be simultaneously injected with tumor cells.To demonstrate the utility of this procedure, we established human U87MG glioma cells as intracranial xenografts in mice, which were then treated with AMG102; a fully human antibody directed to HGF/scatter factor currently undergoing clinical evaluation^2-5. Systemic injection of AMG102 significantly prolonged the survival of all mice with intracranial U87MG xenografts and resulted in a number of complete cures. This study demonstrates that the guide screw method is an inexpensive, highly reproducible approach for establishing intracranial xenografts. Furthermore, it provides a relevant physiological model for validating novel therapeutic strategies for the treatment of brain cancers.     

Endotracheal Intubation in Mice via Direct Laryngoscopy Using an Otoscope

Mice, both wildtype and transgenic, are the principal mammalian model in biomedical research currently. Intubation and mechanical ventilation are necessary for whole animal experiments that require surgery under deep anesthesia or measurements of lung function. Tracheostomy has been the standard for intubating the airway in these mice to allow mechanical ventilation. Orotracheal intubation has been reported but has not been successfully used in many studies because of the substantial technical difficulty or a requirement for highly specialized and expensive equipment. Here we report a technique of direct laryngoscopy using an otoscope fitted with a 2.0 mm speculum and using a 20 G intravenous catheter as an endotracheal tube. We have used this technique extensively and reliably to intubate and conduct accurate assessments of lung function in mice. This technique has proven safe, with essentially no animal loss in experienced hands. Moreover, this technique can be used for repeated studies of mice in chronic models.     

PRIMARY SQUAMOUS CELL CARCINOMA OF THE FALSE VOCAL CORD

Primary squamous cell carcinoma of the false vocal cord may arise on the surface mucosa or may arise beneath it and continue to grow deeply, presenting only a smooth tumescence of the area. These lesions may not cause hoarseness until late in the course of development. Diagnosis of submucosal primary lesions may present difficulty.Widefield laryngectomy is recommended for small primary lesions of the surface mucosa of the false vocal cord. Such lesions do not show edema of the tissues or deep ulceration and do not cause limitation of motion of the false or true vocal cords.For advanced lesions of the false vocal cord which arise on the surface mucosa and cause edema, ulceration and limitation of motion without enlargement of cervical nodes, widefield laryngectomy and elective block dissection of the neck should be done at the primary operation. Patients with such a primary lesion and metastasis to cervical lymph nodes, which are resectable, should be treated in a like manner.Patients with submucosal primary squamous cell carcinoma of the false vocal cord should be treated with widefield laryngectomy and block dissection of the neck, whether or not palpable resectable lymph nodes are noted in the neck. Apparently these lesions metastasize early and widely.     

Noninvasive Intratracheal Intubation to Study the Pathology and Physiology of Mouse Lung

The use of a model that mimics the condition of lung diseases in humans is critical for studying the pathophysiology and/or etiology of a particular disease and for developing therapeutic intervention. With the increasing availability of knockout and transgenic derivatives, together with a vast amount of genetic information, mice provide one of the best models to study the molecular mechanisms underlying the pathology and physiology of lung diseases. Inhalation, intranasal instillation, intratracheal instillation, and intratracheal intubation are the most widely used techniques by a number of investigators to administer materials of interest to mouse lungs. There are pros and cons for each technique depending on the goals of a study. Here a noninvasive intratracheal intubation method that can directly deliver exogenous materials to mouse lungs is presented. This technique was applied to administer bleomycin to mouse lungs as a model to study pulmonary fibrosis.     

Murine Model of Femoral Artery Wire Injury with Implantation of a Perivascular Drug Delivery Patch

Percutaneous interventions including balloon angioplasty and stenting have been used to restore blood flow in vessels with occlusive vascular disease. While these therapies lead to the rapid restoration of blood flow, these technologies remain limited by restenosis in the case of bare metal stents and angioplasty, or reduced healing and possibly enhanced risk of thrombosis in the case of drug eluting stents. A key pathophysiological mechanism in the formation of restenosis is intimal hyperplasia caused by the activation of vascular smooth muscle cells and inflammation due to arterial stretch and injury. Surgeries that induce arterial injury in genetically modified mice are useful for the mechanistic study of the vascular response to injury but are often technically challenging to perform in mouse models due to the their small size and lack of appropriate sized devices. We describe two approaches for a surgical technique that induces endothelial denudation and arterial stretch in the femoral artery of mice to produce robust neointimal hyperplasia. The first approach creates an arteriotomy in the muscular branch of the femoral artery to obtain vascular access. Following wire injury this arterial branch is ligated to close the arteriotomy. A second approach creates an arteriotomy in the main femoral artery that is later closed through localized cautery. This method allows for vascular access through a larger vessel and, consequently, provides a less technically demanding procedure that can be used in smaller mice. Following either method of arterial injury, a degradable drug delivery patch can be placed over or around the injured artery to deliver therapeutic agents.     

一种非手术性小鼠胚胎移植技术

为了提高非手术性小鼠胚胎移植技术的成功率,利用塑料移植导管模拟非手术胚胎移植过程,通过观察染料在子宫角的分布而评估胚胎移植效果,并在此基础上将自然妊娠3.5 d的小鼠囊胚经子宫颈移植受体小鼠。结果表明:将CD-1小鼠囊胚移植假孕2.5 d小鼠单侧子宫角,平均70.9%的胚胎能够发育至成活新生仔鼠,建立了高效非手术性小鼠胚胎移植技术。该方法简便快捷、不易污染、费用低,无需专业的手术器械,且符合实验动物伦理原则,完全可以取代手术法胚胎移植技术,更重要的是,它为人类和其他大动物的胚胎移植提供了研究模型。     

A rapid and non-surgical procedure for jugular catheterization of pigs

A rapid and non-surgical method for jugular catheterization in pigs was set up in 30 piglets of 6.2 kg, 23 pigs of 46 kg and 84 kg and two lactating multiparous sows. The animal was restrained on a V-shaped table (piglets) or with a rope around the mandible (slaughter pigs and sows). The vein was located with the Vacutainer system and a wire guide was inserted into the Vacutainer needle up to the vein lumen. When the needle was removed, the catheter was inserted over the wire guide and advanced until it penetrated the skin and thereafter, the vein wall. The catheter was fixed outside by a large tape and coiled inside a patch just behind the ears. The technique utilizes readily available material and is no more risky for the animal than a single blood sampling. Moreover, it can be performed within 15 to 20 min (including animal restraint) within pens. This new approach might have important implications not only for research purposes by facilitating repeated blood samplings but also for projects which require a rapid and easy method for testing of any kind of pharmaceutical or other type of products under husbandry conditions.     

一种喉部疾病口语声诊断新方法

本文提出了声带的三质量块模型,并应用这模型模拟病噪产生的嘶哑语声,这些嘶声包括有声带闭合不全,声带小结,声带麻痹,喉炎,声带淀粉样变和声门癌等十六种典型情况。采用快速傅里叶变换,线性预测,倒谱技术和离荼余弦变换等分析各类喉病引起的嘶哑语声,实验结果表明声带模型分析法是喉病诊断的一种有效方法。     

改良气管插管法在小鼠心肌梗死模型制备中的应用

目的：小鼠心肌梗死模型制备中采用改良气管插管方法,提高模型制备成功率。方法：小切口暴露小鼠气管,直视下进行经口气管插管,左冠状动脉前降支结扎制备心肌梗死模型,观察、记录小鼠心脏颜色和心电图、术后14d存活情况和心肌组织病理学变化。结果：采用改良气管插管,成功完成40只小鼠心肌梗死模型制作,均可见冠状动脉结扎后,心室前壁颜色变暗,心电图Ⅱ导联ST段明显抬高。除去手术过程中意外死亡,术后14d存活27只,心肌梗死小鼠实际成活率达到87．1％。开胸后,肉眼可见模型组小鼠左室心腔明显扩大,心室壁变薄;病理切片HE染色,镜下可见心肌纤维断裂溶解,心肌细胞坏死,大量炎性细胞浸润。结论：在小鼠心肌梗死模型制备中,采用改良气管插管法,操作简单、易行、创伤小,模型制备成功率高。     

Refinement of intrathymic injection in mice

Direct intrathymic injection is a common procedure used in several types of experimental protocols in the mouse. Currently available approaches involve major surgical procedures that expose the thoracic cavity, resulting in an increased risk of poor recovery and postsurgical complications. The authors sought to refine this surgery to reduce animal pain and distress without compromising overall efficiency of the technique. Using a minimally invasive method that does not expose the thoracic cavity, the authors gave accurately placed intrathymic injections, as confirmed by analyses with a reporter dye. They describe this new approach for intrathymic injection in mice that reduces complications associated with lengthy periods of anesthesia and thoracic cavity exposure.     

A technique for recording from intact phrenic nerve afferents

Recent evidence has suggested that phrenic nerve afferents can influence respiratory motor drive. This paper presents a technique whereby the activity of single phrenic nerve afferents can be recorded from uncut dorsal root filaments. Cervical dorsal roots 4, 5, and 6 were exposed by dorsal laminectomy in 10 anesthetized, spontaneously breathing cats. A stimulating electrode was placed on the right whole phrenic nerve low in the neck. The animal was then placed in a spinal suspension frame. Dissection of the dorsal root filaments was performed with probes made of fine tungsten wire. Single filaments were isolated intact from the dorsal root fascicles and placed across a tungsten electrode. Fiber classification was performed by determining conduction velocity. Monopolar recordings were made from a total of 38 fibers. Tonic activity was observed in 21, respiratory-related activity was evident in 15, and two fibers were silent but could be recruited by phrenic nerve stimulation. The conduction velocities ranged from 2.2 to 103 m/s. Approximately one-half of the fibers had conduction velocities of less than 20 m/s. This technique offers a way to record the activity of diaphragm afferents while maintaining the integrity of possible reflex pathways. Application of this method should prove helpful in elucidating the possible role of the various diaphragm afferents in the control of respiratory motor drive.     

Alterations in the release calls of six European anura (amphibia) after partial or total extirpation of the vocal cords

In the interior of the larynx of Ranidae there are two sturdy vocal cords. The Bufonidae have more delicate vocal cords, and in addition paired cushions of tissue anterior to the cords and paired folds posterior to the cords.In the three ranids Rana esculenta, Rana ridibunda and Rana temporaria, partial or total extirpation of the vocal cords results in loss of voice or atypical release calls. In such remnants of calls as are retained, the frequency composition is little affected, whereas the intensity is always greatly reduced. The most severe impairment is evident in the formation of sound pulses and in the rhythmicity of the pulse sequence.In the three bufonids Bufo bufo, Bufo calamita and Bufo viridis loss of voice is a less common result of the various operations than in the ranids. The most marked deterioration follows removal of all or part of the vocal cords. The tissue cushions and the posterior folds participate, along with the vocal cords, in production of the release calls. Post-operative alterations in the release calls are therefore quite variable.