No funding sources.

1. Preparation of the placenta at delivery
<ol>
	<li>Label the umbilical cords of the twins with one (for the first-born) or two (for the second-born) clamps.</li>
	<li>Inspect the maternal and fetal surface of the placenta for completeness or disruption.</li>
	<li>Record the following data: type of cord insertion (central, eccentric, marginal or velamentous), number of blood vessels in the umbilical cord (usually one vein and two arteries, sometimes only one artery) and color difference between both placental shares. A section of the dividing membranes can be sent to Pathology to confirm the type of chorionicity.</li>
	<li>The placenta can then be placed in a plastic bowl and refrigerated until the final examination (best within one week) and color dye injection.</li>
	<li>The placenta must not be frozen or fixed (do not use formalin).</li>
</ol>
2. Catheterization of the umbilical vessels
<ol>
	<li>Wash the placenta with warm water or saline.</li>
	<li>Trim the peripheral membranes, remove the inter-twin dividing membrane and peel off the amnions (for better visualization of the vascular anastomoses and better quality of the placental pictures).</li>
	<li>Transect each umbilical cord at approximately 5 cm distance from the cord insertion.</li>
	<li>Gently squeeze out blood clots from the umbilical vessels and placental vessels.</li>
	<li>The umbilical vein is usually easy to identify due to its larger diameter, compared to the smaller diameter of the two umbilical arteries.</li>
	<li>Cannulate the umbilical vein with an appropriately sized catheter. Avoid false passages.</li>
	<li>Cannulate one umbilical artery with a smaller catheter. Use tweezers to widen the lumen of the umbilical artery. Avoid false passages. Only one of the 2 umbilical arteries needs to be catheterized since an anastomosis (of Hyrtl) connects the 2 arteries near the cord insertion.</li>
	<li>Repeat both steps for the other umbilical cord.</li>
	<li>Placement of the catheter can be facilitated by gentle back and forth massaging of the umbilical vessels. Any type of catheter can be used for this procedure. We choose to use (and recycle) the catheters used at our neonatology ward for umbilical catheterization in neonates.</li>
	<li>Tie a piece of tape around both cords to avoid back flow of the colored dye during dye injection.</li>
</ol>
3. Injection with colored dye
<ol>
	<li>Connect a 20 ml syringe filled with colored dye to each catheter.</li>
	<li>Any viscous colored dye can be used to visualize the placental angio-architecture. Use contrasting colors to allow good visualization of the anastomoses (dark colors for the arteries, bright colors for the veins).</li>
	<li>Gently inject (with low pressure) the colored dye in the vein while an assistant gently pushes the dye to allow the colored dye to fill all placental vessels, also the smallest ones.</li>
	<li>Pay particular attention to the small vessels near the vascular equator (the vascular equator is the place where the anastomoses from either twin connect with each other).</li>
	<li>Repeat the previous steps to inject colored dye into the artery. Of note: arteries may be more difficult to inject and require more patience.</li>
	<li>Repeat both steps for the other umbilical cord.</li>
</ol>
4. Evaluation and documentation of the placenta after colored dye injection
<ol>
	<li>Carefully examine the vascular equator and record the number and types of anastomoses.</li>
	<li>Place a measuring tape on the placenta to measure the diameters and placental shares on the digital picture.</li>
	<li>Use a high-resolution digital camera and take pictures of the injected placenta. Make sure that the pictures are taken perpendicular to the placenta.</li>
</ol>
5. Representative Results:
The placental angio-architecture in monochorionic twins varies according to the type of monochorionic twin pregnancy. Injection studies have demonstrated that AA, AV and VV anastomoses are present in respectively 80%, 95% and 20% of uncomplicated monochorionic twin pregnancies1 (Figure 1). AA anastomoses are considered to protect against the development of TTTS and TAPS6. Injections studies have shown that AA anastomoses occur in only 20% of TTTS placentas and 10% of TAPS placentas1,2,7 (Figure 2). In TTTS placentas treated with fetoscopic laser surgery, the scars caused by laser coagulation of the vascular anastomoses can be seen on the placental surface (Figure 3 and 4). TAPS placentas are characterized by the presence of only a few minuscule AV anastomoses2 (Figure 5). The placental share of the TAPS recipient is often plethoric, whereas the placental share of the donor is pale (Figure 6). In monochorionic twin pregnancies with birth weight discordance, the growth restricted fetus often has a velamentous cord insertion and a much smaller placental share (Figure 7). AA anastomoses are often present in monochorionic placentas from twins with birth weight discordance8. Monochorionic-monoamniotic placentas have a characteristic angio-architecture with a short distance between both cord insertions (Figure 8). The incidence of AA anastomoses in monoamniotic-monochorionic placentas is virtually 100% and prevents the development of TTTS in monoamniotic twins9. The figures in this article show the characteristic findings of monochorionic placentas injected at our center with color dye. We routinely use darker colors (blue or green) for arteries and lighter colors (yellow, pink or orange) for veins.
<img alt="Figure 1" src="/files/ftp_upload/3208/3208fig1.jpg" /> 
Figure 1. Monochorionic placenta from a normal, uncomplicated monochorionic twin pregnancy showing several AV anastomoses from green arteries to pink veins (white stars), several VA anastomoses from blue arteries to yellow veins (green stars) and 1 large AA anastomosis (identified by the mixing of the blue and green dye; blue star).
<img alt="Figure 2" src="/files/ftp_upload/3208/3208fig2.jpg" /> 
Figure 2. Monochorionic placenta in a TTTS pregnancy treated with serial amnioreduction showing the presence of only AV (white stars) and VA (green stars) anastomoses without an AA anastomosis.
<img alt="Figure 3" src="/files/ftp_upload/3208/3208fig3.jpg" /> 
Figure 3. TTTS placenta after fetoscopic laser coagulation of the vascular anastomoses using the selective laser technique in which a small residual anastomosis was inadvertently left patent (white star). With the selective laser technique, the vascular anastomoses are first identified and subsequently coagulated one by one.
<img alt="Figure 4" src="/files/ftp_upload/3208/3208fig4.jpg" /> 
Figure 4. TTTS placenta after fetoscopic laser coagulation using the Solomon technique in which, after identification and coagulation of each individual anastomosis, the complete vascular equator is coagulated from one placental margin to the other.
<img alt="Figure 5" src="/files/ftp_upload/3208/3208fig5.jpg" /> 
Figure 5. TAPS placenta in which only a few, minuscule VA anastomoses (white stars) are visible along the vascular equator.
<img alt="Figure 6" src="/files/ftp_upload/3208/3208fig6.jpg" /> 
Figure 6. The maternal side of the TAPS placenta (shown in Figure 5) demonstrates the characteristic color difference between both placental shares.
<img alt="Figure 7" src="/files/ftp_upload/3208/3208fig7.jpg" /> 
Figure 7. Monochorionic placenta of a twin pregnancy with selective intrauterine growth restriction of one twin. The growth restricted fetus has a velamentous cord insertion and a much smaller placental share. The white star indicates an AA anastomosis.
<img alt="Figure 8" src="/files/ftp_upload/3208/3208fig8.jpg" /> 
Figure 8. Monoamniotic placenta: Note the various AV (green star), VA (blue star) and the 2 AA anastomoses (white stars), and the short distance between both cord insertions.

<ol>
	<li>Lopriore, E., Middeldorp, J. M., Sueters, M., Vandenbussche, F. P., Walther, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Twin-to-twin+transfusion+syndrome:+from+placental+anastomoses+to+long-term+neurodevelopmental+outcome.">Twin-to-twin transfusion syndrome: from placental anastomoses to long-term neurodevelopmental outcome.</a> Curr. Pediatr. Rev. 1, 191-203 (2005).</li><li>Slaghekke, F., Kist, W. J., Oepkes, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Twin+anemia-polycythemia+sequence:+diagnostic+criteria,+classification,+perinatal+management+and+outcome.">Twin anemia-polycythemia sequence: diagnostic criteria, classification, perinatal management and outcome.</a> Fetal Diagn. Ther. 27, 181-190 (2010).</li><li>Lopriore, E., Middeldorp, J. M., Oepkes, D., Klumper, F. J., Walther, F. J., Vandenbussche, F. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Residual+anastomoses+after+fetoscopic+laser+surgery+in+twin-to-twin+transfusion+syndrome:+frequency,+associated+risks+and+outcome.">Residual anastomoses after fetoscopic laser surgery in twin-to-twin transfusion syndrome: frequency, associated risks and outcome.</a> Placenta. 28, 204-208 (2007).</li><li>Lopriore, E., Slaghekke, F., Middeldorp, J. M., Klumper, F. J., Oepkes, D., Vandenbussche, F. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Residual+anastomoses+in+twin-to-twin+transfusion+syndrome+treated+with+selective+fetoscopic+laser+surgery:+localization,+size,+and+consequences.">Residual anastomoses in twin-to-twin transfusion syndrome treated with selective fetoscopic laser surgery: localization, size, and consequences.</a> Am. J. Obstet. Gynecol. , (2009).</li><li>Lewi, L., Jani, J., Cannie, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intertwin+anastomoses+in+monochorionic+placentas+after+fetoscopic+laser+coagulation+for+twin-to-twin+transfusion+syndrome:+is+there+more+than+meets+the+eye.">Intertwin anastomoses in monochorionic placentas after fetoscopic laser coagulation for twin-to-twin transfusion syndrome: is there more than meets the eye.</a> Am. J. Obstet. Gynecol. 194, 790-795 (2006).</li><li>Denbow, M. L., Cox, P., Taylor, M., Hammal, D. M., Fisk, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Placental+angioarchitecture+in+monochorionic+twin+pregnancies:+relationship+to+fetal+growth,+fetofetal+transfusion+syndrome,+and+pregnancy+outcome.">Placental angioarchitecture in monochorionic twin pregnancies: relationship to fetal growth, fetofetal transfusion syndrome, and pregnancy outcome.</a> Am. J. Obstet. Gynecol. 182, 417-426 (2000).</li><li>van Meir, H., Slaghekke, F., Lopriore, E., van Wijngaarden, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Arterio-arterial+anastomoses+do+not+prevent+the+development+of+twin+anemia-polycythemia+sequence.">Arterio-arterial anastomoses do not prevent the development of twin anemia-polycythemia sequence.</a> Placenta. 31, 163-165 (2010).</li><li>De Paepe, M. E., Shapiro, S., Young, L., Luks, F. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Placental+characteristics+of+selective+birth+weight+discordance+in+diamniotic-monochorionic+twin+gestations.">Placental characteristics of selective birth weight discordance in diamniotic-monochorionic twin gestations.</a> Placenta. 31, 380-386 (2010).</li><li>Umur, A., van Gemert, M. J., Nikkels, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monoamniotic-versus+diamniotic-monochorionic+twin+placentas:+anastomoses+and+twin-twin+transfusion+syndrome.">Monoamniotic-versus diamniotic-monochorionic twin placentas: anastomoses and twin-twin transfusion syndrome.</a> Am. J. Obstet. Gynecol. 189, 1325-1329 (2003).</li><li>Senat, M. V., Deprest, J., Boulvain, M., Paupe, A., Winer, N., Ville, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+laser+surgery+versus+serial+amnioreduction+for+severe+twin-to-twin+transfusion+syndrome.">Endoscopic laser surgery versus serial amnioreduction for severe twin-to-twin transfusion syndrome.</a> N. Engl. J. Med. 351, 136-144 (2004).</li><li>Lopriore, E., Sueters, M., Middeldorp, J. M., Vandenbussche, F. P., Walther, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Haemoglobin+differences+at+birth+in+monochorionic+twins+without+chronic+twin-to-twin+transfusion+syndrome.">Haemoglobin differences at birth in monochorionic twins without chronic twin-to-twin transfusion syndrome.</a> Prenat. Diagn. 25, 844-850 (2005).</li><li>Papathanasiou, D., Witlox, R., Oepkes, D., Walther, F. J., Bloemenkamp, K. W., Lopriore, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monochorionic+twins+with+ruptured+vasa+previa:+double+trouble!.">Monochorionic twins with ruptured vasa previa: double trouble!.</a> Fetal Diagn. Ther. 28, 48-50 (2010).</li><li>Weingertner, A. S., Kohler, A., Kohler, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+and+placental+characteristics+in+four+new+cases+of+twin+anemia-polycythemia+sequence.">Clinical and placental characteristics in four new cases of twin anemia-polycythemia sequence.</a> Ultrasound Obstet. Gynecol. 35, 490-494 (2010).</li><li>Lewi, L., Cannie, M., Blickstein, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Placental+sharing,+birthweight+discordance,+and+vascular+anastomoses+in+monochorionic+diamniotic+twin+placentas.">Placental sharing, birthweight discordance, and vascular anastomoses in monochorionic diamniotic twin placentas.</a> Am. J. Obstet. Gynecol. 197, 587-588 (2007).</li><li>Lewi, L., Gucciardo, L., Huber, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+outcome+and+placental+characteristics+of+monochorionic+diamniotic+twin+pairs+with+early-+and+late-onset+discordant+growth.">Clinical outcome and placental characteristics of monochorionic diamniotic twin pairs with early- and late-onset discordant growth.</a> Am. J. Obstet. Gynecol. , (2008).</li><li>De Paepe, M. E., Friedman, R. M., Poch, M., Hansen, K., Carr, S. R., Luks, F. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Placental+findings+after+laser+ablation+of+communicating+vessels+in+twin-to-twin+transfusion+syndrome.">Placental findings after laser ablation of communicating vessels in twin-to-twin transfusion syndrome.</a> Pediatr. Dev. Pathol. 7, 159-165 (2004).</li><li>De Paepe, M. E., DeKoninck, P., Friedman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+distribution+patterns+in+monochorionic+twin+placentas.">Vascular distribution patterns in monochorionic twin placentas.</a> Placenta. 26, 471-475 (2005).</li><li>Nikkels, P. G., Hack, K. E., vanGemert, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathology+of+twin+placentas+with+special+attention+to+monochorionic+twin+placentas.">Pathology of twin placentas with special attention to monochorionic twin placentas.</a> J. Clin. Pathol. 61, 1247-1253 (2008).</li><li>Quintero, R. A., Martinez, J. M., Lopez, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Individual+placental+territories+after+selective+laser+photocoagulation+of+communicating+vessels+in+twin-twin+transfusion+syndrome.">Individual placental territories after selective laser photocoagulation of communicating vessels in twin-twin transfusion syndrome.</a> Am. J. Obstet. Gynecol. 192, 1112-1118 (2005).</li><li>Quintero, R. A., Comas, C., Bornick, P. W., Allen, M. H., Kruger, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+versus+non-selective+laser+photocoagulation+of+placental+vessels+in+twin-to-twin+transfusion+syndrome.">Selective versus non-selective laser photocoagulation of placental vessels in twin-to-twin transfusion syndrome.</a> Ultrasound Obstet. Gynecol. 16, 230-236 (2000).</li></ol>

No conflicts of interest declared.

TTTS and TAPS are two severe disorders that can occur in monochorionic twins. Both disorders are due to AV anastomoses causing imbalanced intertwin blood flow. In the last 2 decades, fetoscopic laser surgery became available and was shown to be the best method for treatment of TTTS10. The aim of fetoscopic laser treatment is to interrupt the inter-twin circulation through coagulation of the vascular anastomoses on the placental surface. However, the laser treatment for TTTS is far from perfect. Treatment with ...

<table border="1">
	<tbody>
		<tr>
			<th>Name of reagent</th>
			<th>Company</th>
			<th>Catalogue number</th>
			<th>Comments</th>
		</tr>
		<tr>
			<td>Umbilical catheters
(various dimensions, Length 40 cm)		
</td>
			<td>Vygon</td>
			<td>1270.08 (8 F) 
1270.08 (5 F)
1270.04 (4 F)
1270.03 (3.5 F)
1270.02 (2.5 F)	</td>
			<td>Any type of catheter can be used</td>
		</tr>
		<tr>
			<td>20 ml syringes</td>
			<td>BD Plastipak</td>
			<td>300613</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Color dye
(different colors)	
	
</td>
			<td>Royal Talens Schoolverf	</td>
			<td>36716010 (blue)36715010 (green)
36712350 (yellow)
36713570 (pink)</td>
			<td>Any viscous color dye can be used</td>
		</tr>
	</tbody>
</table>

accurate and simple evaluation of vascular anastomoses in monochorionic placenta using colored dye

The presence of placental vascular anastomoses is a conditio sine qua non for the development of twin-to-twin transfusion syndrome (TTTS) and twin anemia polycythemia sequence (TAPS)1,2. Injection studies of twin placentas have shown that such anastomoses are almost invariably present in monochorionic twins and extremely rare in dichorionic twins1. Three types of anastomoses have been documented: from artery to artery, from vein to vein and from artery to vein. Arterio-venous (AV) anastomoses are unidirectional and are referred to as "deep" anastomoses since they proceed through a shared placental cotyledon, whereas arterio-arterial (AA) and veno-venous (VV) anastomoses are bi-directional and are referred to as "superficial" since they lie on the chorionic plate. Both TTTS and TAPS are caused by net imbalance of blood flow between the twins due to AV anastomoses. Blood from one twin (the donor) is pumped through an artery into the shared placental cotyledon and then drained through a vein into the circulation of the other twin (the recipient). Unless blood is pumped back from the recipient to the donor through oppositely directed deep AV anastomoses or through superficial anastomoses, an imbalance of blood volumes occurs, gradually leading to the development of TTTS or TAPS. The presence of an AA anastomosis has been shown to protect against the development of TTTS and TAPS by compensating for the circulatory imbalance caused by the uni-directional AV anastomoses1,2. 
Injection of monochorionic placentas soon after birth is a useful mean to understand the etiology of various (hematological) complications in monochorionic twins and is a required test to reach the diagnosis of TAPS2. In addition, injection of TTTS placentas treated with fetoscopic laser surgery allows identification of possible residual anastomoses3-5. This additional information is of paramount importance for all perinatologists involved in the management and care of monochorionic twins with TTTS or TAPS. Several placental injection techniques are currently being used. We provide a simple protocol to accurately evaluate the presence of (residual) vascular anastomoses using colored dye injection.

Watch this Scientific Journal Video about Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye at JoVE.com

Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye

Twin-to-twin transfusion syndrome and twin anemia polycythemia sequence are two potentially devastating problems in perinatal medicine. Both disorders occur only in monochorionic twins and result from unbalanced blood flow through placental vascular anastomoses. We provide a simple protocol to accurately evaluate the presence of vascular anastomoses using colored dye injection of placental vessels after birth.

The presence of placental vascular anastomoses is a conditio sine qua non for the development of twin-to-twin transfusion syndrome (TTTS) and twin anemia ...

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Research

JoVE Journal

Medicine

26.6K Views.  Leiden University Medical Center. Twin-to-twin transfusion syndrome and twin anemia polycythemia sequence are two potentially devastating problems in perinatal medicine. Both disorders occur only in monochorionic twins and result from unbalanced blood flow through placental vascular anastomoses. We provide a simple protocol to accurately evaluate the presence of vascular anastomoses using colored dye injection of placental vessels after birth.

Video: Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye

Accurate and Simple Measurement of the Pro-inflammatory Cytokine IL-1&beta; using a Whole Blood Stimulation Assay

Inflammatory processes resulting from the secretion of soluble mediators by immune cells, lead to various manifestations in skin, joints and other tissues as well as altered cytokine homeostasis. The innate immune system plays a crucial role in recognizing pathogens and other endogenous danger stimuli. One of the major cytokines released by innate immune cells is Interleukin (IL)-1. Therefore, we utilize a whole blood stimulation assay in order to measure the secretion of inflammatory cytokines and specifically of the pro-inflammatory cytokine IL-1&beta; 1, 2, 3.
Patients with genetic dysfunctions of the innate immune system causing autoinflammatory syndromes show an exaggerated release of mature IL-1&beta; upon stimulation with LPS alone. In order to evaluate the innate immune component of patients who present with inflammatory-associated pathologies, we use a specific immunoassay to detect cellular immune responses to pathogen-associated molecular patterns (PAMPs), such as the gram-negative bacterial endotoxin, lipopolysaccharide (LPS). These PAMPs are recognized by pathogen recognition receptors (PRRs), which are found on the cells of the innate immune system 4, 5, 6, 7. A primary signal, LPS, in conjunction with a secondary signal, ATP, is necessary for the activation of the inflammasome, a multiprotein complex that processes pro-IL-1&beta; to its mature, bioactive form 4, 5, 6, 8, 9, 10.
The whole blood assay requires minimal sample manipulation to assess cytokine production when compared to other methods that require labor intensive isolation and culturing of specific cell populations. This method differs from other whole blood stimulation assays; rather than diluting samples with a ratio of RPMI media, we perform a white blood cell count directly from diluted whole blood and therefore, stimulate a known number of white blood cells in culture 2. The results of this particular whole blood assay demonstrate a novel technique useful in elucidating patient cohorts presenting with autoinflammatory pathophysiologies.

Accurate and Simple Measurement of the Pro-inflammatory Cytokine IL-1&amp;#946; using a Whole Blood Stimulation Assay

We describe a simple immunoassay to measure the production of pro-inflammatory cytokines, such as IL-1 beta production, in patients presenting with autoinflammatory phenotypes. By activating cells in whole blood cultures with pathogen-associated molecular patterns, specifically with lipopolysaccharide, cytokine secretion can be conveniently evaluated in whole blood supernatants.

Inflammatory processes resulting from the secretion of soluble mediators by immune cells, lead to various manifestations in skin, joints and other tissues ...

Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas

Monochorionic (MC) twin pregnancies are associated with significantly higher morbidity and mortality rates than dichorionic twins. Approximately 50% of MC twin pregnancies develop complications arising from the shared placenta and associated vascular connections1. Severe twin-to-twin syndrome (TTTS) is reported to account for approximately 20% of these complications2,3. Inter-twin vascular connections occur in almost all MC placentas and are related to the prognosis and outcome of these high-risk twin pregnancies. The number, size and type of connections have been implicated in the development of TTTS and other MC twin conditions. Three types of inter-twin vascular connections occur: 1) artery to vein connections (AVs) in which a branch artery carrying deoxygenated blood from one twin courses along the fetal surface of the placenta and dives into a placental cotyledon. Blood flows via a deep intraparenchymal capillary network into a draining vein that emerges at the fetal surface of the placenta and brings oxygenated blood toward the other twin. There is unidirectional flow from the twin supplying the afferent artery toward the twin receiving the efferent vein; 2) artery to artery connections (AAs) in which a branch artery from each twin meets directly on the superficial placental surface resulting in a vessel with pulsatile bidirectional flow, and 3) vein to vein connections (VVs) in which a branch vein from each twin meets directly on the superficial placental surface allowing low pressure bidirectional flow. In utero obstetric sonography with targeted Doppler interrogation has been used to identify the presence of AV and AA connections4. Prenatally detected AAs that have been confirmed by postnatal placental injection studies have been shown to be associated with an improved prognosis for both twins5. Furthermore, fetoscopic laser ablation of inter-twin vascular connections on the fetal surface of the shared placenta is now the preferred treatment for early, severe TTTS. 
Postnatal placental injection studies provide a valuable method to confirm the accuracy of prenatal Doppler ultrasound findings and the efficacy of fetal laser therapy6. Using colored dyes separately hand-injected into the arterial and venous circulations of each twin, the technique highlights and delineates AVs, AAs, and VVs. This definitive demonstration of MC placental vascular anatomy may then be correlated with Doppler ultrasound findings and neonatal outcome to enhance our understanding of the pathophysiology of MC twinning and its sequelae. Here we demonstrate our placental injection technique.

Vascular mapping of monochorionic (MC) twin placentas after birth provides a means for detailed demonstration of vascular connections between the twins&#x2019; circulations. 
Imbalance of these connections is thought to play a pivotal role in the development of complications of MC twinning including twin-to-twin transfusion syndrome.

Monochorionic (MC) twin pregnancies are associated with significantly higher morbidity and mortality rates than dichorionic twins. Approximately 50% of MC ...

A Simple Method of Mouse Lung Intubation

A simple procedure to intubate mice for pulmonary function measurements would have several advantages in longitudinal studies with limited numbers or expensive animal. One of the reasons that this is not done more routinely is that it is relatively difficult, despite there being several published studies that describe ways to achieve it. In this paper we demonstrate a procedure that eliminates one of the major hurdles associated with this intubation, that of visualizing the trachea during the entire time of intubation. The approach uses a 0.5 mm fiberoptic light source that serves as an introducer to direct the intubation cannula into the mouse trachea. We show that it is possible to use this procedure to measure lung mechanics in individual mice over a time course of at least several weeks. The technique can be set up with relatively little expense and expertise, and it can be routinely accomplished with relatively little training. This should make it possible for any laboratory to routinely carry out this intubation, thereby allowing longitudinal studies in individual mice, thereby minimizing the number of mice needed and increasing the statistical power by using each mouse as its own control.

This paper describes a striaghforward and efficient method of intubating mice for pulmonary function measurements or pulmonary instillation, that allows the mice to recover and be studied at later times. The procedure involves an inexpensive fiberoptic light source that directly illuminates the trachea.

A  simple procedure to intubate mice for pulmonary function measurements would  have several advantages in longitudinal studies with limited numbers or  ...

Technical Aspects of the Mouse Aortocaval Fistula

Technical aspects of creating an arteriovenous fistula in the mouse are discussed. Under general anesthesia, an abdominal incision is made, and the aorta and inferior vena cava (IVC) are exposed. The proximal infrarenal aorta and the distal aorta are dissected for clamp placement and needle puncture, respectively. Special attention is paid to avoid dissection between the aorta and the IVC. After clamping the aorta, a 25 G needle is used to puncture both walls of the aorta into the IVC. The surrounding connective tissue is used for hemostatic compression. Successful creation of the AVF will show pulsatile arterial blood flow in the IVC. Further confirmation of successful AVF can be achieved by post-operative Doppler ultrasound.

The goal is to produce an arteriovenous fistula that is simple and reproducible. This method does not use sutures or glue adhesive. Therefore the samples can be used with the least amount of foreign materials for analysis.

Technical aspects of creating an arteriovenous fistula in the mouse are discussed. Under general anesthesia, an abdominal incision is made, and the aorta ...

Fast and Accurate Exhaled Breath Ammonia Measurement

This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that uses a quantum cascade based laser. The monitor is coupled to a sampler that measures mouth pressure and carbon dioxide. The system is temperature controlled and specifically designed to address the reactivity of this compound. The sampler provides immediate feedback to the subject and the technician on the quality of the breath effort. Together with the quick response time of the monitor, this system is capable of accurately measuring exhaled breath ammonia representative of deep lung systemic levels. 
Because the system is easy to use and produces real time results, it has enabled experiments to identify factors that influence measurements. For example, mouth rinse and oral pH reproducibly and significantly affect results and therefore must be controlled. Temperature and mode of breathing are other examples. As our understanding of these factors evolves, error is reduced, and clinical studies become more meaningful. This system is very reliable and individual measurements are inexpensive. 
The sampler is relatively inexpensive and quite portable, but the monitor is neither. This limits options for some clinical studies and provides rational for future innovations.

Ammonia is an important physiologic metabolite relevant to various disease and wellness states. It is also a difficult molecule to measure in breath, which demands particular precautions be taken to obtain accurate results. Not all factors influencing ammonia are known, but progress can be difficult without accounting for these factors.

This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that ...

Evaluation of Tumor-infiltrating Leukocyte Subsets in a Subcutaneous Tumor Model

Specialized immune cells that infiltrate the tumor microenvironment regulate the growth and survival of neoplasia.&#160; Malignant cells must elude or subvert anti-tumor immune responses in order to survive and flourish. Tumors take advantage of a number of different mechanisms of immune &#8220;escape,&#8221; including the recruitment of tolerogenic DC, immunosuppressive regulatory T cells (Tregs), and myeloid-derived suppressor cells (MDSC) that inhibit cytotoxic anti-tumor responses. Conversely, anti-tumor effector immune cells can slow the growth and expansion of malignancies: immunostimulatory dendritic cells, natural killer cells which harbor innate anti-tumor immunity, and cytotoxic T cells all can participate in tumor suppression. The balance between pro- and anti-tumor leukocytes ultimately determines the behavior and fate of transformed cells; a multitude of human clinical studies have borne this out. Thus, detailed analysis of leukocyte subsets within the tumor microenvironment has become increasingly important. Here, we describe a method for analyzing infiltrating leukocyte subsets present in the tumor microenvironment in a mouse tumor model. Mouse B16 melanoma tumor cells were inoculated subcutaneously in C57BL/6 mice. At a specified time, tumors and surrounding skin were resected en bloc and processed into single cell suspensions, which were then stained for multi-color flow cytometry. Using a variety of leukocyte subset markers, we were able to compare the relative percentages of infiltrating leukocyte subsets between control and chemerin-expressing tumors. Investigators may use such a tool to study the immune presence in the tumor microenvironment and when combined with traditional caliper size measurements of tumor growth, will potentially allow them to elucidate the impact of changes in immune composition on tumor growth. Such a technique can be applied to any tumor model in which the tumor and its microenvironment can be resected and processed.

This protocol describes a method for the detailed evaluation of leukocyte subsets within the tumor microenvironment in a mouse tumor model. Chemerin-expressing B16 melanoma cells were implanted subcutaneously into syngeneic mice. Cells from the tumor microenvironment were then stained and analyzed by flow cytometry, allowing for detailed leukocyte subset analyses.

Specialized immune cells that infiltrate the tumor microenvironment regulate the growth and survival of neoplasia.&#160; Malignant cells must elude or ...

Using the Sleeve Technique in a Mouse Model of Aortic Transplantation - An Instructional Video

Orthotopic aortic transplantation using the sleeve technique reduces injury to the aorta with failure rate of only 10-20%. The time to anastomose the aorta in mice using the sleeve method was short and easy averaging 20 min, permitting studies of iso/allo grafts. The following article describes the aortic transplantation procedure used in our laboratory. The mice were anesthetized with a mixture of 1.5% volume isoflurane and 100% oxygen through a face mask. At this point, the segment of the aorta between the renal arteries and its bifurcation was separated from the vena cava, freely prepared and clampedat the proximal and distal segments with a single silk suture. Prior to the removal of the aorta, a saline solution containing heparin was injected into the inferior vena cava. Then the aorta was cut between the clamps and a saline heparin solution was used to flush the lumen. The sleeve technique with monofilament sutures was used in order to transplant the abdominal aorta in the orthotopic position.

We present an orthotopic aortic transplantation model using the sleeve technique in mice. It is a very rapid anastomosis method, which can be employed in studies of vascular disease.

Orthotopic aortic transplantation using the sleeve technique reduces injury to the aorta with failure rate of only 10-20%. The time to anastomose the ...

Model Surgical Training: Skills Acquisition in Fetoscopic Laser Photocoagulation of Monochorionic Diamniotic Twin Placenta Using Realistic Simulators

Fetoscopic laser coagulation of arterio-venous anastomoses (AVA) in a monochorionic placenta is the standard of care for twin-twin transfusion syndrome (TTTS), but is technically challenging and can lead to significant complications. Acquiring and maintaining the necessary surgical skills require consistent practice, a critical caseload, and time. Training on realistic surgical simulators can potentially shorten this steep learning curve and enables several proceduralists to acquire procedure-specific skills simultaneously. Here we describe realistic simulators designed to allow the user familiarity with the equipment and specific steps required in the surgical treatment of TTTS, including fetoscopic handling, approaches to anterior and posterior placenta, recognition of anastomoses, and efficient coagulation of vessels. We describe the skills that are especially important in conducting placental laser coagulation that the surgeon can practice on the model and apply in a clinical case. These models can be adapted easily depending on the availability of materials and require standard fetoscopy equipment. Such training systems are complementary to traditional surgical apprenticeships and can be useful aids for fetal medicine units that provide this clinical service.

Practicing the specific skills required for fetoscopic laser coagulation of monochorionic placental anastomoses on realistic models can aid less experienced surgeons in overcoming the steep learning curve associated with this procedure that is now regarded as the standard of care for twin-twin transfusion syndrome.

Fetoscopic laser coagulation of arterio-venous anastomoses (AVA) in a monochorionic placenta is the standard of care for twin-twin transfusion syndrome ...

Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery

Trans-mitral blood flow produces a three-dimensional rotational body of fluid, known as a vortex ring, that enhances the efficiency of left ventricular (LV) filling compared with a continuous linear jet. Vortex ring development is most often quantified with vortex formation time (VFT), a dimensionless parameter based on fluid ejection from a rigid tube. Our group is interested in factors that affect LV filling efficiency during cardiac surgery. In this report, we describe how to use standard two-dimensional (2D) and Doppler transesophageal echocardiography (TEE) to noninvasively derive the variables needed to calculate VFT. We calculate atrial filling fraction (&#946;) from velocity-time integrals of trans-mitral early LV filling and atrial systole blood flow velocity waveforms measured in the mid-esophageal four-chamber TEE view. Stroke volume (SV) is calculated as the product of the diameter of the LV outflow track measured in the mid-esophageal long axis TEE view and the velocity-time integral of blood flow through the outflow track determined in the deep transgastric view using pulse-wave Doppler. Finally, mitral valve diameter (D) is determined as the average of major and minor axis lengths measured in orthogonal mid-esophageal bicommissural and long axis imaging planes, respectively. VFT is then calculated as 4 &#215; (1-&#946;) &#215; SV/(&#960;D3). We have used this technique to analyze VFT in several groups of patients with differing cardiac abnormalities. We discuss our application of this technique and its potential limitations and also review our results to date. Noninvasive measurement of VFT using TEE is straightforward in anesthetized patients undergoing cardiac surgery. The technique may allow cardiac anesthesiologists and surgeons to assess the impact of pathological conditions and surgical interventions on LV filling efficiency in real time.

We describe a protocol to measure vortex formation time, an index of left ventricular filling efficiency, using standard transesophageal echocardiography techniques in patients undergoing cardiac surgery. We apply this technique to analyze vortex formation time in several groups of patients with differing cardiac pathologies.

Trans-mitral blood flow produces a three-dimensional rotational body of fluid, known as a vortex ring, that enhances the efficiency of left ventricular ...

Echocardiographic Evaluation of Atrial Communications before Transcatheter Closure

Transthoracic (TTE) and transesophageal echocardiography (TEE) is the standard imaging method for atrial septal defect (ASD) and patent foramen ovale (PFO) detection, for patient selection for transcatheter ASD/PFO closure,&#160;for intraoperative guidance and for long-term follow-up. The size, shape, location and the number of the atrial communications schould be determined. The accuracy of PFO detection can be improved by using agitated saline together with maneuvers to transiently increase the right atrial (RA) pressure. The appearance of microbubbles in the left atrium (LA) within 3 cardiac cycles after opacification of the RA is considered positive for the presence of an intracardiac shunt. Three dimensional TEE identifies further septal fenestrations and describes the dynamic morphology of ASD/PFO and atrial septal aneurysm. Follow-up evaluations with TTE is recommended at 1, 6, and 12 months after the procedure, with a subsequent evaluation every year. Previous studies showed an increased incidence of atrial arrhythmias early after device closure. Speckle tracking analysis may help to understand functional left atrial remodeling following percutaneous closure and its impact on atrial arrhythmias.

Transthoracic (TTE) and transesophageal (TEE) echocardiography represent the basic imaging tools for interatrial septum examination. Three dimensional (3D) TEE provides incremental information in the assessment of the interatrial septum. Further advanced echocardiography techniques using speckle tracking echocardiography are applied for sensitive volumetric and functional assessment of the heart chambers.&#160;

Transthoracic (TTE) and transesophageal echocardiography (TEE) is the standard imaging method for atrial septal defect (ASD) and patent foramen ovale ...