1. Case Presentation
<ol>
	<li>The patient is set up for a visit at the gynecological clinic, often due to the occurrence of bleeding disorders. A physical examination is performed.
	<ol>
		<li>If deemed appropriate, the patient is scheduled for a hysterectomy. The paperwork is prepared, and the patient is given the premedication for the day of surgery.</li>
		<li>Patients 60 years and older must first submit blood samples and monitored by electrocardiography (or ECG) prior to the procedure.</li>
	</ol>
	</li>
	<li>On the day of surgery, the patient is not allowed to consume anything by mouth for six hours prior to admittance.
	<ol>
		<li>An exception is made for sweet clear drinks without pulp, which are allowed until two hours prior to admittance.</li>
		<li>The patient takes the premedication (t.Paracetemol 1 g + t.Etodolac 300 mg + t.Dexamethason 8 mg) with the last drink.</li>
	</ol>
	</li>
	<li>The patient is admitted app. one hour prior to the scheduled time of surgery.
	<ol>
		<li>The ward nurse first prepares the patient for surgery.</li>
		<li>The anesthesiologist examines the patient and prepares the papers for anesthesia.</li>
	</ol>
	</li>
	<li>When the operation room is prepared and the team is ready, the gynecologist transports the patient to the operating room.
	<ol>
		<li>The patient lies down on the operating table and is covered with a surgical blanket.</li>
		<li>An i.v. line is placed in the left hand and 1,000 ml of saline is started. Monitoring equipment is attached.</li>
		<li>Anesthesia is induced with propofol and remifentanil until Loss Of Consciousness (LOC) occurs, and maintained using TOF.</li>
		<li>For facilitating intubation, a small dose of rocuronium (15 mg) is administered.</li>
		<li>Direct laryngoscopy is performed. If it is difficult to visualize the vocal cord, the McGrath videolaryngoscop is used. Intubation is subsequently performed.</li>
	</ol>
	</li>
	<li>Insufflation of the abdomen is started at 12 mm Hg CO2.
	<ol>
		<li>The ports are placed.</li>
		<li>The procedure is started.</li>
		<li>The surgeons are told when Train Of Four (TOF) ratio is &gt; 90%, corresponding to the neuromuscular blockade is weaned off.</li>
		<li>At the neck of the grasper the distance from the promontory to the surface of the skin at the umbilicus is marked.</li>
		<li>The grasper is placed on the surgical table. With measuring tape, the distance between the end of the grasper and the neck of the grasper (at surgeon's finger) is marked, and then calculated distance is measured in centimeters.</li>
	</ol>
	</li>
	<li>The insufflations pressure of CO2 is lowered to 8 mm Hg.
	<ol>
		<li>At the neck of the grasper the distance from the promontory to the surface of the skin at the umbilicus is marked.</li>
		<li>The grasper is placed at the table. With measuring tape the marked distance is interpreted to centimeters.</li>
	</ol>
	</li>
	<li>CO2 insufflation pressure is adjusted to 12 mm Hg.
	<ol>
		<li>Deep neuromuscular blockade is applied to a Post Tetanic Count (PTC) &lt; 2.</li>
		<li>At the neck of the grasper the distance from the promontory to the surface of the skin at the umbilicus is marked.</li>
		<li>The grasper is placed at the table. With measuring tape the marked distance is measured to centimeters.</li>
	</ol>
	</li>
	<li>CO2 insufflation pressure is lowered to 8 mm Hg.
	<ol>
		<li>At the neck of the grasper the distance from the promontory to the surface of the skin at the umbilicus is marked.</li>
		<li>At the neck of the grasper the distance from the promontory to the surface of the skin at the umbilicus is marked.</li>
	</ol>
	</li>
	<li>The procedure is finished.
	<ol>
		<li>Infusions of propofol and remifentanil are terminated.</li>
		<li>The patient is woken up and moved to his or her bed.</li>
		<li>The patient is transferred to the Recovery Room.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Jones, R. K., Caldwell, J. E., Sorin, C. B., Brull, J., Soto, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversal+of+Profound+Rocuronium-induced+Blockade+with+Sugammadex.">Reversal of Profound Rocuronium-induced Blockade with Sugammadex.</a> Anesthesiology. 109, 816-824 (2008).</li><li>Berg, H., Roed, J., Viby-Mogensen, J., Mortensen, C. R., Enfbaek, J., Skovgaard, L. T., Krintel, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Residual+neuromuscular+block+is+a+risk+factor+for+post-operative+pulmonary+complications:+A+prospective,+randomized,+and+blinded+study+of+postoperative+pulmonary+complications+after+atracurium,+vecuronium+and+pancuronium.">Residual neuromuscular block is a risk factor for post-operative pulmonary complications: A prospective, randomized, and blinded study of postoperative pulmonary complications after atracurium, vecuronium and pancuronium.</a> Acta Anaesthesiol. Scand. 41, 1095-1103 (1997).</li><li>Abrishami, A., Ho, J., Wong, J., Yin, L., Chung, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sugammadex,+a+selective+reversal+medication+for+preventing+postoperative+residual+neuromuscular+blockade.">Sugammadex, a selective reversal medication for preventing postoperative residual neuromuscular blockade.</a> The Cochrane Collaborations. , (2009).</li><li>Plaud, B., Debaene, B., Donati, F., Marty, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Residual+Paralysis+after+Emergence+from+Anesthesia.">Residual Paralysis after Emergence from Anesthesia.</a> Anesthesiology. 112, 1013-1022 (2010).</li><li>Lee, D. W., Kim, M. J., Lee, Y. K., Lee, H. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Does+Intraabdominal+Pressure+Affect+Development+of+Subcutaneous+Emphysema+at+Gynecologic+Laparoscopy?.">Does Intraabdominal Pressure Affect Development of Subcutaneous Emphysema at Gynecologic Laparoscopy?.</a> Minimally Invasive Gynecology. , 761-765 (2011).</li><li>Sandhu, T., Yamada, S., Ariyakachon, V., Chakrabandhu, T., Chongruksut, W., Ko-iam, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-pressure+pneumoperitoneum+versus+standard+pneumoperitoneum+in+laparoscopic+cholecystectomy,+a+prospective+randomized+clinical+trial.">Low-pressure pneumoperitoneum versus standard pneumoperitoneum in laparoscopic cholecystectomy, a prospective randomized clinical trial.</a> Surg. Endosc. 23, 1044-1047 (2009).</li><li>Sarli, L., Coisti, R., Sansebastiano, G., Trivelli, M., Roncoroni, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prospective+randomized+trial+of+low-pressure+pneumoperitoneum+for+reduction+of+shoulder-tip+pain+following+laparoscopy.">Prospective randomized trial of low-pressure pneumoperitoneum for reduction of shoulder-tip pain following laparoscopy.</a> British Journal of Surgery. 87, 1161-1165 (2000).</li><li>Kandil, T. S., El Hefnawy, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shoulder+pain+following+laparoscopic+cholecystectomy:+factors+affecting+the+incidence+and+severity.">Shoulder pain following laparoscopic cholecystectomy: factors affecting the incidence and severity.</a> J. Laparoendosc. Adv. Surg. Tech. A. 8, 677-682 (2010).</li><li>Mulier, J. P., Dillemans, B. R. S., Crombach, M., Missant, C., Sels, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+abdominal+pressure+volume+relationship.">On the abdominal pressure volume relationship.</a> The internet Journal of Anesthesiology. 21, (2009).</li><li>Srvastava, A., Niranjan, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Secrets+of+safe+laparoscopic+surgery:+Anaesthetic+and+surgical+considerations.">Secrets of safe laparoscopic surgery: Anaesthetic and surgical considerations.</a> J. Minim. Access. Surg. 6, 91-94 (2010).</li><li>Grosse-Sundrup, M., Henneman, J. P., Sandberg, W. S., Bateman, B. T., Uribe, J. V., Nguyen, N. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intermediate+acting+non-depolarizing+neuromuscular+blocking+agents+and+risk+of+postoperative+respiratory+complications:+prospective+propensity+score+matched+cohort+study.">Intermediate acting non-depolarizing neuromuscular blocking agents and risk of postoperative respiratory complications: prospective propensity score matched cohort study.</a> BMJ. 345, e6329 (2012).</li><li>Kaneko, G., Miyajima, A., Yazawa, S., Yuge, K., Kikuchi, E., Asanuma, H., Nakagawa, K., Oya, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=What+is+the+predictor+of+prolonged+operative+time+during+laparoscopic+radical+prostatectomy?.">What is the predictor of prolonged operative time during laparoscopic radical prostatectomy?.</a> Int. J. Urol. 20 (3), 330-336 (2012).</li><li>Drahonovsky, J., Haakova, L., Otcenasek, M., Krofta, L., Kucera, E., Feyereisl, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+prospective+randomized+comparison+of+vaginal+hysterectomy,+laparoscopically+assisted+vaginal+hysterectomy,+and+total+laparoscopic+hysterectomy+in+women+with+benign+uterine+disease.">A prospective randomized comparison of vaginal hysterectomy, laparoscopically assisted vaginal hysterectomy, and total laparoscopic hysterectomy in women with benign uterine disease.</a> Eur. J. Obstet. Gynecol. Reprod. Biol. 148 (2), 172-176 (2010).</li></ol>

No conflicts of interest declared.

Directly calculating the working volume available for laproscopic surgery is difficult, but the relationship between insufflating CO2 pressure and abdominal volume is easier to measure9. Here, we present a method to use the surgical grasper to estimate the space within the abdomen during insufflation, as an alternative to the method of recording the volume of insufflated CO2. These measurements have demonstrated that it is possible to maintain a steady volume when loweri...

Neuromuscular blocking agents are commonly used to facilitate tracheal intubation, and, during anesthesia, to facilitate surgery. The use of pharmacological agents to achieve deep relaxation throughout the laparoscopic procedure allows the surgeons either to proceed at the same level of CO2 insufflation while benefitting from better surgical conditions, or lowering the insufflating pressure to lower the risk of surgical complications. Several studies have shown the positive effect of lowering the working pressure 5,6,7. One symptom that is often seen after laparoscopic hysterectomies is shoulder pain, which is often stated as a major problem and the most important issue when speaking to the patient at follow up.8
Laproscopic myomectomy or hysterectomy is usually recommended when more conservative methods fail to control the symptoms caused by uterine fibroids. At our institution, these procedures are performed at an insufflating CO2 pressure of 12 mm Hg. There are two highly experienced gynecologists performing all the gynecologic cases. All our cases are anaesthetized with propofol and remifentanil, and intubation is often facilitated with a low dose of rocuronium (15 mg).
From our daily clinical work we have identified shoulder pain as one of the most disturbing side effects after laparoscopic hysterectomies, which is supported by the literature 8. Studies have shown that reducing the intraabdominal pressure can also reduce shoulder pain. In an effort to reduce the CO2 insufflation pressure, one of our prior concerns was if the surgical field and visibility during the procedure would be compromised. Trying to determine the overview during the procedure, we set up a method to compare the intraabdominal working space. However, it can be very difficult to monitor the exact intra-abdominal volume within a patient during surgery. In a Belgian study, the volume-pressure relationship has been described, but the study authors concluded that there are major inter individual variations 9. In order to get a more reliable statement of the intraabdominal space, we use the distance from the promontory to the skin as the metric.

deep neuromuscular blockade leads to a larger intraabdominal volume during laparoscopy

Shoulder pain is a commonly reported symptom following laparoscopic procedures such as myomectomy or hysterectomy, and recent studies have shown that lowering the insufflation pressure during surgery may reduce the risk of post-operative pain. In this pilot study, a method is presented for measuring the intra-abdominal space available to the surgeon during laproscopy, in order to examine whether the relaxation produced by deep neuromuscular blockade can increase the working surgical space sufficiently to permit a reduction in the CO2 insufflation pressure. Using the laproscopic grasper, the distance from the promontory to the skin is measured at two different insufflation pressures: 8 mm Hg and 12 mm Hg. After the initial measurements, a neuromuscular blocking agent (rocuronium) is administered to the patient and the intra-abdominal volume is measured again. Pilot data collected from 15 patients shows that the intra-abdominal space at 8 mm Hg with blockade is comparable to the intra-abdominal space measured at 12 mm Hg without blockade. The impact of neuromuscular blockade was not correlated with patient height, weight, BMI, and age. Thus, using neuromuscular blockade to maintain a steady volume while reducing insufflation pressure may produce improved patient outcomes.

This pilot study of 15 patients was performed to assess the impact of deep neuromuscular blockade during laparoscopic surgery.
The method illustrated here was used to obtain measurements of intra-abdominal space in patients undergoing laparoscopic hysterectomy (Figure 1). In each patient, measurements of intra-abdominal space were taken under the following conditions: 12 mm Hg pressure without deep neuromuscular blockade, 12 mm Hg with blockade, 8 mm Hg without blockade, and ...

Watch this Scientific Journal Video about Deep Neuromuscular Blockade Leads to a Larger Intraabdominal Volume During Laparoscopy at JoVE.com

Deep Neuromuscular Blockade Leads to a Larger Intraabdominal Volume During Laparoscopy

This article presents a method for measuring the working abdominal volume during laproscopic myomectomy using the surgical grasper, and applies this technique to obtain pilot data on whether deep neuromuscular blockade (NMB) can enable the use of lower insufflation pressure. Reduced insufflation pressure during laproscopic surgery has been shown to reduce post-operative pain, and thus the use of NMB during surgery may enable improved patient outcomes.

Shoulder pain is a commonly reported symptom following laparoscopic procedures such as myomectomy or hysterectomy, and recent studies have shown that ...

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13.0K Views.  Aleris-Hamlet Hospitals, Soeborg, Denmark.  This article presents a method for measuring the working abdominal volume during laproscopic myomectomy using the surgical grasper, and applies this technique to obtain pilot data on whether deep neuromuscular blockade (NMB) can enable the use of lower insufflation pressure. Reduced insufflation pressure during laproscopic surgery has been shown to reduce post-operative pain, and thus the use of NMB during surgery may enable improved patient outcomes. 

Video: Deep Neuromuscular Blockade Leads to a Larger Intraabdominal Volume During Laparoscopy

Intra-Operative Behavioral Tasks in Awake Humans Undergoing Deep Brain Stimulation Surgery

Deep brain stimulation (DBS) is a surgical procedure that directs chronic, high frequency electrical stimulation to specific targets in the brain through implanted electrodes. Deep brain stimulation was first implemented as a therapeutic modality by Benabid et al. in the late 1980s, when he used this technique to stimulate the ventral intermediate nucleus of the thalamus for the treatment of tremor 1. Currently, the procedure is used to treat patients who fail to respond adequately to medical management for diseases such as Parkinson's, dystonia, and essential tremor. The efficacy of this procedure for the treatment of Parkinson's disease has been demonstrated in well-powered, randomized controlled trials 2. Presently, the U.S. Food and Drug Administration has approved DBS as a treatment for patients with medically refractory essential tremor, Parkinson's disease, and dystonia. Additionally, DBS is currently being evaluated for the treatment of other psychiatric and neurological disorders, such as obsessive compulsive disorder, major depressive disorder, and epilepsy. 
DBS has not only been shown to help people by improving their quality of life, it also provides researchers with the unique opportunity to study and understand the human brain. Microelectrode recordings are routinely performed during DBS surgery in order to enhance the precision of anatomical targeting. Firing patterns of individual neurons can therefore be recorded while the subject performs a behavioral task. Early studies using these data focused on descriptive aspects, including firing and burst rates, and frequency modulation 3. More recent studies have focused on cognitive aspects of behavior in relation to neuronal activity 4,5. This article will provide a description of the intra-operative methods used to perform behavioral tasks and record neuronal data with awake patients during DBS cases. Our exposition of the process of acquiring electrophysiological data will illuminate the current scope and limitations of intra-operative human experiments.

Deep brain stimulation surgery offers a unique opportunity to examine information encoding in the awake human brain. This article will describe intra-operative methods used to perform cognitive and behavioral tasks while simultaneously acquiring physiological data such as EMG, single-unit neuronal activity and/or local field potentials.

Deep brain stimulation (DBS) is a surgical procedure that directs chronic, high frequency electrical stimulation to specific targets in the brain through ...

Dorsal Column Steerability with Dual Parallel Leads using Dedicated Power Sources:  A Computational Model

In spinal cord stimulation (SCS), concordance of stimulation-induced paresthesia over painful body regions is a necessary condition for therapeutic efficacy. Since patient pain patterns can be unique, a common stimulation configuration is the placement of two leads in parallel in the dorsal epidural space. This construct provides flexibility in steering stimulation current mediolaterally over the dorsal column to achieve better pain-paresthesia overlap. Using a mathematical model with an accurate fiber diameter distribution, we studied the ability of dual parallel leads to steer stimulation between adjacent contacts on dual parallel leads using (1) a single source system, and (2) a multi-source system, with a dedicated current source for each contact. The volume conductor model of a low-thoracic spinal cord with epidurally-positioned dual parallel (2 mm separation) percutaneous leads was first created, and the electric field was calculated using ANSYS, a finite element modeling tool. The activating function for 10 um fibers was computed as the second difference of the extracellular potential along the nodes of Ranvier on the nerve fibers in the dorsal column. The volume of activation (VOA) and the central point of the VOA were computed using a predetermined threshold of the activating function. The model compared the field steering results with single source versus dedicated power source systems on dual 8-contact stimulation leads. The model predicted that the multi-source system can target more central points of stimulation on the dorsal column than a single source system (100 vs. 3) and the mean steering step for mediolateral steering is 0.02 mm for multi-source systems vs 1 mm for single source systems, a 50-fold improvement. The ability to center stimulation regions in the dorsal column with high resolution may allow for better optimization of paresthesia-pain overlap in patients.

Using a mathematical model of spinal cord stimulation, we found that a multi-source system with independent power sources for each contact can target more central points of stimulation on the dorsal column (100 vs 3) and has 50-fold more field steering resolution (0.02mm vs 1mm) than a single-source system.

In spinal cord stimulation (SCS), concordance of stimulation-induced paresthesia over painful body regions is a necessary condition for therapeutic ...

Utilizing Transcranial Magnetic Stimulation to Study the Human Neuromuscular System

Transcranial magnetic stimulation (TMS) has been in use for more than 20 years 1, and has grown exponentially in popularity over the past decade. While the use of TMS has expanded to the study of many systems and processes during this time, the original application and perhaps one of the most common uses of TMS involves studying the physiology, plasticity and function of the human neuromuscular system. Single pulse TMS applied to the motor cortex excites pyramidal neurons transsynaptically 2 (Figure 1) and results in a measurable electromyographic response that can be used to study and evaluate the integrity and excitability of the corticospinal tract in humans 3. Additionally, recent advances in magnetic stimulation now allows for partitioning of cortical versus spinal excitability 4,5. For example, paired-pulse TMS can be used to assess intracortical facilitatory and inhibitory properties by combining a conditioning stimulus and a test stimulus at different interstimulus intervals 3,4,6-8. In this video article we will demonstrate the methodological and technical aspects of these techniques. Specifically, we will demonstrate single-pulse and paired-pulse TMS techniques as applied to the flexor carpi radialis (FCR) muscle as well as the erector spinae (ES) musculature. Our laboratory studies the FCR muscle as it is of interest to our research on the effects of wrist-hand cast immobilization on reduced muscle performance6,9, and we study the ES muscles due to these muscles clinical relevance as it relates to low back pain8. With this stated, we should note that TMS has been used to study many muscles of the hand, arm and legs, and should iterate that our demonstrations in the FCR and ES muscle groups are only selected examples of TMS being used to study the human neuromuscular system.

Transcranial magnetic stimulation (TMS) is a non-invasive tool to gain insight on the physiology and function of the human nervous system. Here, we present our TMS techniques to study cortical excitability of the upper limb and lumbar musculature.

Transcranial magnetic stimulation (TMS) has been in use for more than 20 years 1, and has grown exponentially in popularity over the past decade.  While ...

Construction of Vapor Chambers Used to Expose Mice to Alcohol During the Equivalent of all Three Trimesters of Human Development

Exposure to alcohol during development can result in a constellation of morphological and behavioral abnormalities that are collectively known as Fetal Alcohol Spectrum Disorders (FASDs). At the most severe end of the spectrum is Fetal Alcohol Syndrome (FAS), characterized by growth retardation, craniofacial dysmorphology, and neurobehavioral deficits. Studies with animal models, including rodents, have elucidated many molecular and cellular mechanisms involved in the pathophysiology of FASDs. Ethanol administration to pregnant rodents has been used to model human exposure during the first and second trimesters of pregnancy. Third trimester ethanol consumption in humans has been modeled using neonatal rodents. However, few rodent studies have characterized the effect of ethanol exposure during the equivalent to all three trimesters of human pregnancy, a pattern of exposure that is common in pregnant women. Here, we show how to build vapor chambers from readily obtainable materials that can each accommodate up to six standard mouse cages. We describe a vapor chamber paradigm that can be used to model exposure to ethanol, with minimal handling, during all three trimesters. Our studies demonstrate that pregnant dams developed significant metabolic tolerance to ethanol. However, neonatal mice did not develop metabolic tolerance and the number of fetuses, fetus weight, placenta weight, number of pups/litter, number of dead pups/litter, and pup weight were not significantly affected by ethanol exposure. An important advantage of this paradigm is its applicability to studies with genetically-modified mice. Additionally, this paradigm minimizes handling of animals, a major confound in fetal alcohol research.

We demonstrate the construction of alcohol vapor chambers using readily available materials that simultaneously house 6 mouse cages. We further describe their use in a mouse model of fetal alcohol exposure equivalent to all 3&#160;trimesters of human pregnancy. This paradigm exposes animals during gestation and postnatal days 1-12.

Exposure to alcohol during development can result in a constellation of morphological and behavioral abnormalities that are collectively known as Fetal ...

Clinical Assessment of Spatiotemporal Gait Parameters in Patients and Older Adults

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and neurological patients1-4, but also in healthy older adults5,6. The quantitative gait analysis described in this protocol is performed with a recently-introduced photoelectric system (see&#160;Materials table) which has the potential to be used in the clinic because it is portable, easy to set up (no subject preparation is required before a test), and does not require maintenance and sensor calibration. The photoelectric system consists of series of high-density floor-based photoelectric cells with light-emitting and light-receiving diodes that are placed parallel to each other to create a corridor, and are oriented perpendicular to the line of progression7. The system simply detects interruptions in light signal, for instance due to the presence of feet within the recording area. Temporal gait parameters and 1D spatial coordinates of consecutive steps are subsequently calculated to provide common gait parameters such as step length, single limb support and walking velocity8, whose validity against a criterion instrument has recently been demonstrated7,9. The measurement procedures are very straightforward; a single patient can be tested in less than 5 min&#160;and a comprehensive report can be generated in less than 1&#160;min.

This protocol is used to evaluate spatial and temporal gait variables of neurological/orthopedic patients and older persons by means of a recently-introduced floor-based photocell system.

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and ...

Using Saccadometry with Deep Brain Stimulation to Study Normal and Pathological Brain Function

The oculomotor system involves a large number of brain areas including parts of the basal ganglia, and various neurodegenerative diseases including Parkinson's and Huntington's can disrupt it. People with Parkinson's disease, for example, tend to have increased saccadic latencies. Consequently, the quantitative measurement of saccadic eye movements has received considerable attention as a potential biomarker for neurodegenerative conditions. A lot more can be learned about the brain in both health and disease by observing what happens to eye movements when the function of specific brain areas is perturbed. Deep brain stimulation is a surgical intervention used for the management of a range of neurological conditions including Parkinson's disease, in which stimulating electrodes are placed in specific brain areas including several sites in the basal ganglia. Eye movement measurements can then be made with the stimulator systems both off and on and the results compared. With suitable experimental design, this approach can be used to study the pathophysiology of the disease being treated, the mechanism by which DBS exerts it beneficial effects, and even aspects of normal neurophysiology.

This paper describes the use of quantitative measurement of eye movements in conjunction with stimulation of focal areas of the deep brain in order to study physiology, pathophysiology, and the mechanisms of deep brain stimulation.

The oculomotor system involves a large number of brain areas including parts of the basal ganglia, and various neurodegenerative diseases including ...

Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise

Exercise is a stress to the pulmonary vasculature. With incremental exercise, the pulmonary diffusing capacity (DLCO) must increase to meet the increased oxygen demand; otherwise, a diffusion limitation may occur. The increase in DLCO with exercise is due to increased capillary blood volume (Vc) and membrane diffusing capacity (Dm). Vc and Dm increase secondary to the recruitment and distension of pulmonary capillaries, increasing the surface area for gas exchange and decreasing pulmonary vascular resistance, thereby attenuating the increase in pulmonary arterial pressure. At the same time, the recruitment of intrapulmonary arteriovenous anastomoses (IPAVA) during exercise may contribute to gas exchange impairment and/or prevent large increases in pulmonary artery pressure.
We describe two techniques to evaluate pulmonary diffusion and circulation at rest and during exercise. The first technique uses multiple-fraction of inspired oxygen (FIO2) DLCO breath holds to determine Vc and Dm at rest and during exercise. Additionally, echocardiography with intravenous agitated saline contrast is used to assess IPAVAs recruitment.
Representative data showed that the DLCO, Vc, and Dm increased with exercise intensity. Echocardiographic data showed no IPAVA recruitment at rest, while contrast bubbles were seen in the left ventricle with exercise, suggesting exercise-induced IPAVA recruitment.
The evaluation of pulmonary capillary blood volume, membrane diffusing capacity, and IPAVA recruitment using echocardiographic methods is useful to characterize the ability of the lung vasculature to adapt to the stress of exercise in health as well as in diseased groups, such as those with pulmonary arterial hypertension and chronic obstructive pulmonary disease.

To assess the pulmonary diffusion and vasculature responses to exercise, we describe the multiple-inspired oxygen diffusion capacity technique to determine capillary blood volume and membrane diffusing capacity, as well as agitated saline contrast echocardiography to assess the recruitment of intrapulmonary arteriovenous anastomoses.

Exercise is a stress to the pulmonary vasculature. With incremental exercise, the pulmonary diffusing capacity (DLCO) must increase to meet the increased ...

Laparoscopy-endoscopy Cooperative Surgery for the Treatment of Gastric Gastrointestinal Stromal Tumors

In view of the shortcomings of endoscopic or laparoscopic surgeries alone in the treatment of gastric gastrointestinal stromal tumors (G-GISTs), this approach makes an innovative improvement in the treatment of G-GISTs that are less than 5 cm in size. Laparoscopy-endoscopy cooperative surgery (LECS) is used to combine endoscopic and laparoscopic surgeries, fully realizing their respective advantages and avoiding their drawbacks. The main steps are as follows. First, gastroscopy and laparoscopy are combined to confirm the location and boundary of the tumor. Tumor resection is carried out laparoscopically, guided by a gastroscope. The specimen is removed orally and the gastric wound closed laparoscopically. Then, gastroscopy and laparoscopy are combined to determine whether there is wound bleeding, if the suture is satisfactory, and if the gastric cavity is deformed.
LECS has natural advantages in the treatment of G-GISTs that are less than 5 cm in size. The accurate estimation of tumor location and boundary greatly improves the complete resection rate of tumors. The risk of tumor rupture is substantially reduced, and the long-term prognosis of patients is significantly improved. The process allows for accurate resection of the tumor, maximum preservation of normal gastric tissue and organ function, and avoids postoperative gastric deformation. The patient's postoperative rehabilitation is greatly accelerated, and oral feeding can resume on the day of the operation. The specimen is taken out through the mouth to avoid the need for an extended abdominal incision. This greatly reduces the patient's postoperative pain and scarring. The method greatly shortens the postoperative hospital stay (i.e., discharge is possible on the day after the operation), increasing the turnover of hospital beds.

Laparoscopy-endoscopy cooperative surgery is appropriate for the treatment of gastric gastrointestinal stromal tumors less than 5 cm in size. It can achieve the respective advantages of endoscopic and laparoscopic surgeries while avoiding their drawbacks.

In view of the shortcomings of endoscopic or laparoscopic surgeries alone in the treatment of gastric gastrointestinal stromal tumors (G-GISTs), this ...

Functional Assessment of the Donor Heart During Ex Situ Perfusion: Insights from Pressure-Volume Loops and Surface Echocardiography

Heart transplantation remains the gold standard treatment for advanced heart failure. However, the current critical organ shortage has resulted in the allocation of a growing number of donor hearts with extended criteria. These marginal grafts are associated with a high risk of primary graft failure and may benefit from ex situ perfusion before transplant. This technology allows for extended organ preservation using warm oxygenated blood perfusion with continuous metabolic monitoring. The only NESP device currently available for clinical practice perfuses the organ in an unloaded non-working state, which does not allow for functional assessment of the beating heart. We therefore developed an original platform of NESP in working mode conditions with adjustment of left ventricular preload and afterload. This protocol was applied in porcine hearts. Ex situ functional assessment of the heart was achieved with intracardiac conductance catheterization and surface echocardiography. Along with a description of the experimental protocol, we herein report the main results, as well as pearls and pitfalls associated with the acquisition of pressure-volume loops and myocardial power during NESP. Correlations between hemodynamic findings and ultrasound variables are of major interest, especially for further rehabilitation of donor hearts before transplantation. This protocol aims to improve the assessment of donor hearts to both increase the donor pool and reduce the incidence of primary graft failure.

Functional Assessment of the Donor Heart During Ex Situ Perfusion: Insights from Pressure-Volume Loops and Surface Echocardiography

A reliable noninvasive approach for functional assessment of the donor heart during normothermic ex situ heart perfusion (NESP) is lacking. We herein describe a protocol for ex situ assessment of myocardial performance using the epicardial echocardiography and conductance catheter method.

Heart transplantation remains the gold standard treatment for advanced heart failure. However, the current critical organ shortage has resulted in the ...

Using Nicotine in a Silica-Exposed Mouse Model to Promote Lung Epithelial-Mesenchymal Transition

Smoking and exposure to silica are common among occupational workers, and silica is more likely to injure the lungs of smokers than non-smokers. The role of nicotine, the primary addictive ingredient in cigarettes, in silicosis development is unclear. The mouse model employed in this study was simple and easily controlled, and it effectively simulated the effects of chronic nicotine ingestion and repeated exposure to silica on lung fibrosis through epithelial-mesenchymal transition in human beings. In addition, this model can help in the direct study of the effects of nicotine on silicosis while avoiding the effects of other components in cigarette smoke.
After environmental adaptation, mice were injected subcutaneously with 0.25 mg/kg nicotine solution into the loose skin over the neck every morning and evening at 12 h intervals over 40 days. Additionally, crystalline silica powder (1-5 &#181;m) was suspended in normal saline, diluted to a suspension of 20 mg/mL, and dispersed evenly using an ultrasonic water bath. The isoflurane-anesthetized mice inhaled 50 &#181;L of this silica dust suspension through the nose and were awoken via chest massage. Silica exposure was administrated daily on days 5-19.
The double-exposed mouse model was exposed to nicotine and then silica, which matches the exposure history of workers who are exposed to both harmful factors. In addition, nicotine promoted pulmonary fibrosis through epithelial-mesenchymal transformation (EMT) in mice. This animal model can be used to study the effects of multiple factors on the development of silicosis.

This study describes a mouse model to study the synergistic effect of nicotine on the progression of pulmonary fibrosis in experimental silicosis mice. The dual-exposure mouse model simulates the pathological progression in the lung after simultaneous exposure to nicotine and silica. The methods described are simple and highly reproducible.

Smoking and exposure to silica are common among occupational workers, and silica is more likely to injure the lungs of smokers than non-smokers. The role ...