February 2012: This Month in JoVE

Summary

Here are some highlights from the February 2012 Issue of Journal of Visualized Experiments (JoVE).

Protocol

MALDI Imaging Mass Spectrometry of Neuropeptides in Parkinson's Disease

Jörg Hanrieder^{1, 2}, Anna Ljungdahl¹, Malin Andersson^1
1Department of Pharmaceutical Biosciences, Uppsala University, ²Department of Chemical and Biological Engineering, Chalmers University of Technology

Dopamine replacement pharmacotherapy using L-DOPA is the most commonly used symptomatic treatment of Parkinson's disease, but is accompanied by side effects including involuntary abnormal movements, termed dyskinesia ¹. Here, a protocol for MALDI imaging mass spectrometry is presented that detects changes in rat brain neuropeptide levels related to dyskinesia.

Detection of Microregional Hypoxia in Mouse Cerebral Cortex by Two-photon Imaging of Endogenous NADH Fluorescence

Oksana Polesskaya¹, Anita Sun², Gheorghe Salahura², Jharon N. Silva¹, Stephen Dewhurst¹, Karl Kasischke^3
1Department of Microbiology and Immunology, University of Rochester Medical Center, ²Center for Neural Development and Disease, University of Rochester Medical Center, ³Deptartment of Neurology, Center for Neural Development and Disease, University of Rochester Medical Center

Here we describe a method to directly visualize microregional tissue hypoxia in the mouse cortex in vivo. It is based on concurrent two-photon imaging of nicotinamide adenine dinucleotide (NADH) and the cortical microcirculation. This method is useful for high resolution analysis of tissue oxygen supply.

MAME Models for 4D Live-cell Imaging of Tumor: Microenvironment Interactions that Impact Malignant Progression

Mansoureh Sameni¹, Arulselvi Anbalagan¹, Mary B. Olive¹, Kamiar Moin^{1, 2}, Raymond R. Mattingly^{1, 2}, Bonnie F. Sloane^{1, 2
1}Department of Pharmacology, Wayne State University , ²Barbara Ann Karmanos Cancer Institute, Wayne State University

We have developed 3D coculture models for live-cell imaging in real-time of interactions among breast tumor cells and other cells in their microenvironment that impact progression to an invasive phenotype. These models can serve as preclinical screens for drugs to target paracrine-induced proteolytic, chemokine/cytokine and kinase pathways implicated in invasiveness.

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

Sven Möbius-Winkler, Marcus Sandri, Norman Mangner, Phillip Lurz, Ingo Dähnert, Gerhard Schuler
University of Leipzig Heart Center

The accompanying video describes a procedure for percutaneous placement of the WATCHMAN Left Atrial Appendage (LAA) Device. The WATCHMAN is a nitinol device designed to be permanently implanted at, or slightly distal to, the opening of the left atrial appendage (LAA) to trap blood clots before they exit the LAA, preventing thromboembolic stroke.

Measuring Left Ventricular Pressure in Late Embryonic and Neonatal Mice

Victoria P. Le¹, Attila Kovacs², Jessica E. Wagenseil^1
1Department of Biomedical Engineering, Saint Louis University, ²Department of Internal Medicine, Washington University School of Medicine

Measuring left ventricular pressure (LV) in embryonic and neonatal mice is described. Pressure is measured by inserting a needle connected to a fluid-filled transducer into the LV under ultrasound guidance. Care must be taken to maintain normal cardiac function during the experimental protocol.

In vitro Mesothelial Clearance Assay that Models the Early Steps of Ovarian Cancer Metastasis

Rachel A. Davidowitz, Marcin P. Iwanicki, Joan S. Brugge
Department of Cell Biology, Harvard Medical School

The mesothelial clearance assay described here takes advantage of fluorescently labeled cells and time-lapse video microscopy to visualize and quantitatively measure the interactions of ovarian cancer multicellular spheroids and mesothelial cell monolayers. This assay models the early steps of ovarian cancer metastasis.

Saliva, Salivary gland, and Hemolymph Collection from Ixodes Scapularis Ticks

Toni G. Patton¹, Gabrielle Dietrich², Kevin Brandt¹, Marc C. Dolan², Joseph Piesman², Robert D. Gilmore Jr.^1
1Microbiology and Pathogenesis Activity, Bacterial Diseases Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, ²Tick-Borne Diseases Activity, Bacterial Diseases Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention

The collection of infected tick hemolymph, salivary glands, and saliva is important to study how tick-borne pathogens cause disease. In this protocol we demonstrate how to collect hemolymph and salivary glands from feeding Ixodes scapularis nymphs. We also demonstrate saliva collection from female I. scapularis adults.

A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation

Dietmar Bänsch, Ralph Schneider, Ibrahim Akin, Cristoph A. Nienaber
Heart Center Rostock, University Hospital of Rostock, Germany

Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the Linox^SMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the second electrode.