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Genotyping of knockout (KO) mice

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Knockout (KO) mice are genetically modified (transgenic) mice in which one or more genes are turned off. Such animal models can be helpful tools in providing information of the biological function of a gene.

At the institute we use several mouse strains with different gene modifications. The genotypes of these mice are determined by PCR (polymerase chain reaction), a method used to amplify a specific region of a DNA strand. The PCR products are analysed by agarose gel electrophorersis to check for precence or not of DNA fragments of interest.

The figure shows results from genotyping of mice with an inducible cardiomyocyte-specific excision of the Atp2a2 (Serca2) gene (SERCA2 KO) (K. Andersson, G. Christensen). The upper band represents Cre-recombinase wich is expressed in the KO only , the lower band represents an internal control, thus samples with two bands are from SERCA2 KO mice, samples with one band are from control mice.


Cell function

Many projects at IEMR studies the activity and function of individual cells in health and disease. Currently, most focus is given to cardiac and skeletal muscle cells. These cells have the ability to contract in response to electrical stimulation. In diseases such as heart failure, all levels of the process linking electrical stimulation to contraction and relaxation are affected in muscle cells. It is therefore important to study both the electrical properties (patch-clamp technique and field-stimulation) and contractile properties of cells (edge detection and single-fiber measurements).

Patch-clamp technique: An electrical circuit is established between the cell interior and exterior by the aid of ultra-fine glass pipettes. Control and measurements of current and voltage is possible for the study of ion-channels and ion fluxes.

Field-stimulation: Individual cells or groups of cells are stimulated by applying an electrical field to the cell bath. Contraction and ion fluxes are elicited and measured.

Edge detection: The cell borders are marked an traced by the aid of specialised video-based equipment. Speed and amplitude of contractions are measured.

Single-fiber measuremenets: The two ends of a single muscle fiber are attached to an a power meter for measurements of power, amplitude and speed of contractions.

Mechanical stretch of cell cultures: Cells cultured in petri-dishes are exposed to quantifiable passive stretch, eliciting responses in expression and activity of proteins.


In vivo cardiac function

Echo with VisualSonics Vevo 2100
Echo with VisualSonics Vevo 2100

At the institute, we have equipment for advanced in vivo cardiac
phenotyping.

Echocardiography
A high resolution VisualSonics Vevo 2100 is available. With a 25 and 35 MHz
scanhead, the scanner can be used for smaller species. The equipment allows
detailed mapping of both cardiac structure and function, but is also
available for eg. cancer research.

We also have a Vivid 7 echocardiograph equipped with a M3S, M12L, i13L and
T6 scanheads. Thus, both standard echocardiography and transesophageal
examinations can be performed; the latter in larger species.

Telemetry
DSI telemetry with 16 transmitters allows high throughput monitoring of
cardiac rhythm, motion, temperature and blood pressure.

Pressure and PV-catheters
We have pressure catheters from Millar and Samba, and PV-catheters from
Millar. Pressure catheters allows invasive hemodynamic measurements and
accurate detection of cardiac function. Pressure-volume analysis allows pre-
and afterload-independent hemodynamic studies and measurement of cardiac
contractility in vivo, among others suitable for studying cardiac signaling
pathways and drug testing.

Exercise training
Treadmills from Columbus/Linton is available for exercise training of
smaller species.

Skeletal muscle function
In vivo skeletal muscle function can be tested with both isometric and
dynamic protocols. Setups from Aurora Instruments allows superior dynamic
control of force and length, and can be used for eg. acute exercise and
fatigue protocols.


Cell imaging


In our laboratory, we predominantly image cells using fluorescence. This is a technique in which cells are labeled with compounds called fluorescent probes or dyes. When excited, these compounds emit light (fluoresce) which we then detect by two different techniques; whole-cell photometry and laser confocal microscopy. The whole-cell photometry technique allows for stable fluorescence recordings from the entire cell over long periods without cell damage. When greater spatial resolution is required, we employ laser confocal microscopy which allows recording of fluorescence from only a specific layer of the cell while excluding regions which are out of focus.

We routinely employ Ca2+-sensitive dyes to examine Ca2+ homeostasis in cardiac muscle cells. In these experiments the dye is loaded into the cytosol, and by recording the fluorescence of the dye we can estimate the cytosolic [Ca2+]. Using the same principles, we employ other dyes to measure cytosolic [Na+] and pH. Fluorescent probes can also be used to examine cell structure. For example, dyes which label the cell membrane or nuclei can be used to determine whether these structures are altered in pathological conditions. With high resolution imaging, the precise localization of specific proteins, such as ion channels and pumps, can also be investigated. In these experiments, the proteins are often labeled with a specific antibody in combination with a secondary antibody which carries the fluorescent probe. By simultaneously labeling two different proteins, we can determine if they are located nearby each other (“co-localized”). We can gain even greater insight into co-localization by employing the newest technique available in our lab, called FRET. This technique relies on measuring fluorescence resulting from energy transfer between two nearby proteins. In combination, these fluorescence techniques give us significant insight into ionic homeostasis, by providing information on both ionic concentrations and the localization of proteins which control these levels.


New MR

Magnet

Our new Varian 9.4 T MR machine is now installed and the first experiments have been performed.


Constructions at IEMR

operation theatre

After a long period with a lot of construction work at the Institute, the new laboratory facilities on 4th floor are now ready to use. We have also got new offices and new operation theaters on 5th floor.


homepage IEMR


Institute for Experimental Medical Research (IEMR)

Cover-Pages from IEMR-annual report 2013

Institutt for eksperimentell medisinsk forskning (IEMF): www.iemf.no
Head of Institute: Professor Ole M. Sejersted, MD, Ph.D.

Address:
Institute for Experimental Medical Research (IEMR),
Oslo University Hospital, Ullevål
PB 4956 Nydalen, NO-0424 Oslo, Norway

Visiting and Delivery address:
Kirkeveien 166 (Ullevål sykehus), Building 7, 4th floor, 0450 Oslo, Norway

Phone: +47 23 01 68 00 Fax: +47 23 01 67 99

Please read the documents:
- Research Groups & Available Methods
- VISION AND STRATEGY, IEMR
- IEMR Annual report 2013


About Institute for Experimental Medical Research (IEMR)

Norwegian: Institutt for eksperimentell medisinsk forskning (IEMF)

The IEMR was established in 1951 at the initiative of Carl B. Semb (1895 - 1971), Professor of Surgery, and made possible through a grant from shipowner Anders Jahre (1891- 1982). Their idea was to create an environment that promoted research in collaboration with the clinical departments at Oslo University Hospital - Ullevål. The links to the hospital's Department of Surgery have always been close.

Professor Fredrik Kiil (1921 - 2015 ) served as Head of Institute from 1961 to 1991. He developed the first extensively used artificial kidney and established renal physiology as the major research area at the Institute. Through several years professor Morten Harboe (1929- ) built up a strong group in immunology and leprosy research. This field was abandoned when Harboe moved his group to the National Hospital in 1983. Kiil also initiated research in cardiac and vascular physiology, and professor Arnfinn Ilebekk (1941- ) has headed this research until he retired in 2011. Morten G. Ræder (1939-2012) joined the IEMR in 1982 following his appointment as Professor of Surgical Pathophysiology. He has since been investigating mechanisms of biliary and pancreatic secretion. Professor Ræder retired at the age of 70 in January 2009. Professor of Anesthesia, Petter A. Steen (1947- ) , has supervised research activity relating to heart and lung resuscitation since 1982 and retired in 2014.

Ole M. Sejersted  was appointed Professor and Head of Department in1991. Since then, renal physiology ceased to be an area of investigation, and the focus shifted to cardiovascular research in addition to continued activity in biliary and pancreatic research. Cellular and molecular biological techniques have been introduced. He retired in 2017.

Geir Christensen MD, PhD was appointed Director of Research in 1998 and professor in 2003. Ivar Sjaastad VMD, MD, PhD succeeded Professor Ræder in 2009. Alessandro Cataliotti MD, PhD succeeded Professor Ilebekk in 2013.

Ivar Sjaastad was appointed Acting Head of Department in 2017.

The Institute now has three research Groups. ( See Group leaders).

Other investigators from the hospital also use facilities at the Institute for their Research. (see Associated group leaders).

Please read the document: VISION AND STRATEGY, IEMR

Address: www.iemr.no

Logo:

LOGO IEMR


Brief history

The IEMR was established in 1951 at the initiative of Carl B. Semb, Professor of Surgery, and made possible through a grant from shipowner Anders Jahre. Their idea was to create an environment that promoted research in collaboration with the clinical departments at Oslo University Hospital - Ullevål. The links to the hospital's Department of Surgery have always been close.

Professor Fredrik Kiil served as Head of Institute from 1961 to 1991. He developed the first extensively used artificial kidney and established renal physiology as the major research area at the Institute. Through several years professor Morten Harboe built up a strong group in immunology and leprosy research. This field was abandoned when Harboe moved his group to the National Hospital in 1983. Kiil also initiated research in cardiac and vascular physiology, and professor Arnfinn Ilebekk has headed this research for many years. Morten G. Ræder joined the IEMR in 1982 following his appointment as Professor of Surgical Pathophysiology. He has since supervised his own group investigating mechanisms biliary and pancreatic secretion. Professor Ræder retired at the age of 70 in January 2009. Professor of Anesthesia, Petter A. Steen, has supervised research activity relating to heart and lung resuscitation since 1982.

Ole M. Sejersted was appointed Professor and Head of Institute in 1991. Since then, renal physiology ceased to be an area of investigation, and the focus shifted to cardiovascular research in addition to continued activity in biliary and pancreatic research. Cellular and molecular biological techniques have been introduced. Geir Christensen MD, Ph.D. was appointed Director of Research in 1998 and professor in 2003.

The Institute now has four research groups headed by Christensen, Sejersted, Ilebekk and Steen. Other investigators from the hospital also use facilities at the Institute for their research. Thus, professor Jarle Vaage at Ullevål has had a laboratory at the Institute at his disposal for some years


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