DSI Monitor - Fall 2015 (Issue 3)

  • Blood Pressure Measurement in the News

    A landmark NIH clinical trial ended last week, showing that intensive blood pressure management may save lives and improve health. This announcement is sure to bring a great deal of discussion about what these findings mean for patient care. DSI is proud of its 25 year history providing scientists with blood pressure solutions for their nonclinical work. Many blood pressure medications in use today were tested during development with DSI blood pressure telemetry. We look forward to providing today’s scientists with the tools they need to deliver the next generation of treatments to control hypertension.

    Read our white paper on the current state-of-the-art technology that meets the AHA guidelines for blood pressure measurement in animals. 

  • Adjustment to sensitization and challenge protocols restores allergy-induced asthmatic responses in guinea pig models

    Allergic asthma is a condition that causes coughing, wheezing, shortness of breath, rapid breathing and tightness in the chest. These symptoms are the result of the immune system overreacting to harmless antigens (allergens), such as tree pollen. Allergic asthma is characterized by early and late asthmatic responses (EARs and LARs) following the introduction of an allergen. An EAR is an asthma response that occurs immediately and usually resolves after a couple hours; a LAR is a delayed asthma response, which can occur hours after exposure to an allergen. LARs are followed by airway hyperresponsiveness (AHR)—increased airway sensitivity to a bronchoconstrictor stimulus. Among humans, the time point at which the response occurs is highly variable.

    Researchers are learning more about asthmatic responses to allergens by using guinea pigs as a model for functional parameters of the condition. Guinea pigs are a valuable animal model because compared to humans they have a similar distribution of mast cells, which play a key role in inflammation. Also, compared to mice models, guinea pig EAR bronchoconstriction is pronounced and responsive to more inflammatory mediators. However, studies in recent years have shown that guinea pigs have become less sensitive to a standard protocol used for eliciting EAR, LAR, AHR and airway inflammation. Thus, to re-establish the conditions necessary to use guinea pigs in asthma research, this studyassessed lung function and inflammation in relation to several different protocols.

    The study used the antigen ovalbumin (Ova)—the main protein found in egg white—to elicit asthmatic responses. (Ova is commonly used in allergen challenges, and an Ova protocol had been previously developed and successfully used in guinea pig studies.) Six male guinea pigs were sensitized with Ova injections. Aluminum hydroxide (Al(OH)3) was administered with the Ova to enhance immune response.  After allowing time for antibodies and immune responses to develop, the guinea pigs underwent an allergen challenge: exposure to inhaled Ova for one hour. A control group was sensitized in the same way, but exposed to aerosolized saline. Six different sensitization and challenge conditions were performed, with variable Ova challenge doses, numbers of sensitizations, Ova sensitization doses, Al(OH)3 doses, and challenge days. Following the allergen challenges, specific airway conductance (sGaw) measurements were used to assess EAR and LAR. Airway response to histamine was measured to assess AHR. After lung function tests, the guinea pigs were euthanized. Lung tissue was sampled and eosinophils, macrophages, lymphocytes, and neutrophils were counted to determine the effect of the sensitization and challenges on pulmonary inflammation.

    For this study, functional asthmatic responses were assessed using DSI’s Buxco® respiratory solutions. Using the patented Allay™ restraint in a double-chamber plethysmograph, Buxco Non-Invasive Airway Mechanics (NAM) technology measured sGaw in conscious, spontaneously breathing guinea pigs. Airway responses to aerosolized histamine before and after the Ova challenge were also measured using the same technology.

    Results confirmed the protocol that had been used in previous studies no longer achieved the full range of desired effects. Ultimately, the authors found that increasing the Ova sensitization and challenge concentrations restored AHR, increased the peak of the EAR, and increased eosinophils. From that point, either increasing the Al(OH)3 concentration during sensitization or extending the duration between Ova sensitization and challenge induced EAR, LAR, AHR and pulmonary inflammation. In addition, allowing more time for the immune response to develop before the challenge prolonged the EAR and LAR. Interestingly, there was also a dissociation between AHR and the influx of inflammatory cells, highlighting the importance of assessing asthmatic responses directly, rather than relying on cell counts alone.

    1Lowe, A. P. P., Broadley, K. J., Nials, A. T., Ford, W. R. & Kidd, E. J. (2015). Adjustment of sensitisation and inflammatory responses to ovalbumin in guinea-pigs. Journal of Pharmacological and Toxicological Methods, 72: 85-93. doi: 10.1016/j.vascn.2014.10.007 

    To read the complete article, visit: http://www.ncbi.nlm.nih.gov/pubmed/25450500

  • Tips and Tricks from Scientific Services: Verifying Catheter Tip in Mouse Carotid Surgery

    To ensure catheter patency throughout the duration of the study, the catheter tip must be positioned inside the aortic arch. If the catheter tip remains in the carotid artery, it will clot and patency will be lost. Depending on the mouse strain, gender and weight, the catheter may have to be advanced to different lengths to reach the aortic arch. It is recommended, before any survival surgery is performed, to verify the catheter tip placement for each type of mouse to be implanted. This can be done by performing a sternotomy on a cannulated, euthanized mouse and locating the aortic arch. Measurements can be taken to determine the appropriate length to insert the catheter. Follow the directions below to locate the catheter tip in an implanted animal. 

    1. Euthanize the animal by standard technique. Do not use cervical dislocation. This can damage the catheter.
    2. Using a small surgical scissors, cut the subcutaneous pocket open where the transmitter is positioned. Start at the caudal aspect of the pocket and incise cranially, taking care not to cut the catheter.
    3. Remove the transmitter from the pocket and continue to incise cranially to the ventral neck region, taking care not to cut the catheter.
    4. Once the catheter is free from all connective tissue, gently pick up the transmitter and place it on the table near the animal’s head. This will prevent accidental cutting of the catheter.
    5. Using a small surgical scissors, make a midline incision over the abdomen and extend the incision cranially to cut through the diaphragm and sternum.
    6. Using a small surgical scissors, cut through the rib cage on both the right and left lateral sides to fully expose the thoracic cavity.
    7. Locate the heart. The thymus will first need to be dissected before the aortic arch can be visualized. The thymus is white in color and can be gently removed. Be careful to only grasp the thymus during the dissection. Avoid grasping any vessels as the catheter will be located underneath the thymus in the aortic arch.
    8. Once the thymus is removed, locate the aortic arch. Gently isolate the arch from the surrounding tissue.
    9. Place a fine-tipped forceps under the arch to locate the catheter tip. If the catheter tip cannot be visualized inside of the arch, move cranially with the vessel to locate the tip.
    10. Determine where the tip of the catheter is positioned in relation to the aortic arch. If the catheter is in the optimal location, then the distance the catheter was inserted was correct. If the catheter is not in the optimal location, then adjustments will need to be made before any survival surgery is performed. The recommended procedure is to measure from the carotid bifurcation or the most cranial ligation suture to the junction of the carotid artery and aortic arch and add an additional 2-3 mm.
    11. By verifying catheter tip placement, adjustments can be made, if needed, for subsequent surgeries involving the same strain, gender and weight of animal.
    12. Repeat this process when changing to a new strain, gender or weight of animal.

    Optimal catheter placement in aortic arch

    Optimal catheter placement in aortic arch

  • New Online Tools! Get Answers to your Data and Validation Services Questions

    Do you have questions about how to best acquire or analyze your data? How about questions regarding validation of DSI products? We have made it easier to get those questions answered. Provide some information to help us understand your questions or concerns and we'll be in touch with you soon!

    Submit this form for Data Services questions (located on our Data Services webpage):

    Submit this form for Validation Services questions: (located on our Validation Services webpage): http://www.datasci.com/services/dsi-validation-services/validation-services-inquiry
  • Technical Note Spotlight: Storing Your Implants

    Check out our tech note to learn the best way to store your new or exchanged implants.
  • Ask DSI Technical Support

    Q: I am unable to hear my PhysioTel™ Digital implants using the AM radio or locate them when scanning in the software. What am I doing wrong?

    A:   To successfully power ON and configure PhysioTel Digital implants, keep the following in mind:

    1. PhysioTel Digital implants operate on a different frequency than legacy PhysioTel devices. Legacy implants operated on a frequency of 455 kHz, which could be heard on an AM radio. PhysioTel Digital implants operate on a different frequency range (EU 863-868 MHz and US 908-920 MHz). AM radio will not pick up the PhysioTel Digital implant signal and cannot be used as an indicator. 
    2. Non-implanted devices may not be discovered during system configuration because of environmental noise. The implant antenna was designed and programmed for optimal performance when implanted. Therefore, low-level environmental noise can interfere with implants that are in the package.

    To reduce environmental noise and simulate implantation, hold a packaged implant between your hands or place between two saline bags while scanning in the setup wizard. This will help block ambient noise and allow a packaged implant to be detected and configured. Once a device is successfully configured, the sensitivity can be adjusted through the Diagnostics page. Adjusting the sensitivity will ensure the packaged implant can communicate with the system during pre-surgery testing, such as pressure or temperature verification.

    To adjust sensitivity of an implant that has been configured:

    1. Access the Diagnostics page for the CLC to which your implant is assigned.
    2. Select Implant Commands from the left-hand menu.
    3. On the Implant Commands page, select the Implant ID from the Implant ID drop-down box.
    4. Select Set RSSI Threshold from the Implant Command drop-down box. A box will appear above the Send button with a value of ‘ff’.
    5. Replace ‘ff’ with the desired RSSI Threshold value of 12.
    6. Click the Send button to set the RSSI threshold. 

    Once implanted, turning the device OFF and ON again will reset the sensitivity to the level needed for optimal implanted performance.

    Please contact DSI Technical Support at support@datasci.com for additional questions or concerns.


  • New Analysis Software: Automated detection of data patterns, arrhythmias and other anomalies

    Data Insights features custom searches, interactive tools, and sophisticated display settings to accelerate your research and reveal new possibilities. Contact your DSI representative to schedule a demonstration and learn how you can optimize your data analysis process.

    Ponemah v5.20-SP7, compatible with Data Insights, is also available now!

  • Ponemah™ v6.10: Get More From Your Telemetry Data

    Ponemah v6.10 is now available! The new Ponemah v6.10 integrates PhysioTel Digital, glucose monitoring, and remote notification for smart data collection and analysis.
  • Transition Reminders

    PA-C40 Discontinuation
    DSI will be discontinuing production of the PA-C40 implants. Please see our Discontinued Products page for discontinuation dates.
    The HD-S10 is the successor to the PA-C40. The HD-S10 features several improvements:
    • Addition of body temperature parameter
    • An extra month of battery life
    • Smaller size for improved tolerance

    The HD-S10 implant includes the technological advancements of the PhysioTel™ HD platform: battery life monitoring, auto-configuration, and encoded ID.

    DSI is providing special transition pricing to help customers convert to HD-S10 implants. 

    D70 Discontinuation
    DSI will be discontinuing production of the the D70 implant models. Please see our Discontinued Products page for a list of discontinuation dates by model.
    The PhysioTel Digital platform provides several technological advancements compared to the D70 implants. PhysioTel Digital enhancements include:
    • Auto-configuration to reduce setup time and cost 
    • Improved physiologic measurement sensitivity
    • Social housing capability to enhance animal welfare
    • Longer transmission range
    • Clean, digital data to improve data accuracy
    • Automated positive animal ID to avoid animal handling mistakes

    Thank you if you have already transitioned to the recommended replacement models. If you still need to do so, please contact your DSI sales representative to develop a transition plan.

  • Glucose News

    • DSI's continuous glucose telemetry implant was selected as a finalist for the R&D 100RD100_2015Finalist_Logo Awards!
    • Will continuous glucose monitoring enhance science and animal welfare? Partner with NC3Rs and DSI to prove and share the value of continuous glucose monitoring. Learn more here.
    • See our glucose testimonials to learn how researchers are using continuous glucose monitoring to advance their research.
  • Data Acquisition Survey

    Help us better understand your data acquisition sampling protocol by participating in this brief survey. The survey will take less than five minutes to complete.
  • Upcoming Events

    User Group Meetings: See and Share the Latest in Science

    Fall 2015

    The 2015 DSI East Coast User Group Meeting is just two months away! We have an exciting agenda of presentations covering a variety of scientific topics, and will also offer ample time for networking with your peers and DSI team members. Our technical support team will be present to field questions and demonstrate our latest solutions. We are looking forward to a great meeting!

    Please visit our website for agenda updates and meeting details. Additional questions about the 2015 DSI East Coast User Group Meeting can be sent to Meeting and Event Planner Jennifer Seidl.

    Spring 2016: Stay Tuned for Additional Details!

    • United States West Coast User Group Meeting
    • 9th Dutch Telemetry User Group Meeting - March 17, 2016

    Scientific Meetings

    If you plan to attend any of these upcoming meetings, please visit the DSI booth! (Read more here.)

    Hypertension: Scientific Sessions, September 16-19

    3rd Annual Helmholtz-Nature Medicine Diabetes Conference, September 19-21   

    ISAN2015, September 26-29  

    Safety Pharmacology 15th Annual Meeting September 28-October 31  Don’t miss DSI’s hosted presentations at the annual SPS meeting. Click here for details.

    Glucose Clamp Seminar October 7  

    Association of Inhalation Toxicologists (AIT) Annual Conference October 15-19 

    Society for Neuroscience October 17-21 

    AALAS workshop; Animal Handling Techniques for Respiratory Research Applications in Rodents November 3 

    36th Annual American College of Toxicology Meeting November 8-11