This work was supported by the United States Federal Drug Administration (FDA) contract HHSF223201310224C and the United States National Institutes of Health/FDA grant 1U01FD004573-01.

The authors have nothing to disclose.

على الرغم، كما سبق ذكره، فإن مفهوم المخدرات العلاجية ومراقبة التزام تاكروليماس بناء على بقع الدم المجفف جذابة، هناك تحديات التحليلية التي تتجاوز تلك التي ترتبط عادة مع تحليل LC-MS / MS التاكروليموس في EDTA وريدي عينات الدم الكامل. وتشمل هذه، ولكن ليس على سبيل الحصر، أن ال?...

تاكروليماس هو immonosuppressant قوية 7/1 التي لديها بنية ماكروليد 8 (الشكل 1). نظرا لرابطة الدول المستقلة - تصاوغ العابر للسندات CN أنها تشكل اثنين rotamers في حل 9 التي يمكن أن تكون مفصولة مرحلة عكس الكروماتوغرافيا السائلة عالية الأداء (HPLC) التاكروليموس هو محبة للدهون وقابل للذوبان في الكحول (الميثانول: 653 غرام / لتر، والإيثانول: 355 ز / L)، والهيدروكربونات الهالوجينية (كلوروفورم: 573 غرام / لتر) والأثير. وهو قابل للذوبان لماما في الهيدروكربونات الأليفاتية (الهكسان: 0.1 جرام / لتر والمياه (درجة الحموضة 3: 0.0047 جم / L) 9 لا يحتوي جزيء أي حامل اللون والحد الأقصى للأشعة فوق البنفسجية امتصاصه هو 192 نانومتر التاكروليموس الأعمال عن طريق تثبيط الكالسينيورين. وقد تم استعراض آلية العمل في المراجع 10،11. ويستخدم حاليا في أكثر من 80٪ من مرضى زرع الأعضاء الصلبة، في الولايات المتحدة 12. المؤشر العلاجي للتاكروليماس هو considereد أن يكون ضيقا 13. وبالإضافة إلى ذلك، فإن العلاقة بين الجرعات تاكروليماس وتركيزات الدم ضعيف والدوائية هو متغير 14،15. مراقبة الأدوية العلاجية لتوجيه تاكروليماس الجرعات في مرضى زرع هو الممارسة السريرية ولالعامة 16-20. الهدف هو الحفاظ على تركيزات تاكروليماس الدم ضمن نطاق العلاجية المحددة مسبقا. تركيزات تاكروليماس الدم أقل من المستوى العلاجي قد يؤدي إلى زيادة نشاط التفاعلات ألو المناعة المزمنة أو الحادة، بينما تركيزات أعلى من النافذة العلاجية تزيد من خطر الإفراط في كبت المناعة والسرطان والسميات، مثل الكلوي، العصبية، ارتفاع ضغط الدم، ومرض السكري. عالية التباين داخل الفرد الدوائية التاكروليموس قد يكون ضارا لكلا زرع الأعضاء وبقاء المريض 21،22. في حين تقلب بين الفردية الدوائية تاكروليماس تسببه أساسا الأشكال CYP3A5، أسباب داخل الفردتقلب تشمل، ولكنها لا تقتصر على، المخدرات المخدرات، والمرض للعقاقير والمخدرات التفاعلات الغذاء 14،15. تفتقر أيضا الانضمام إلى مناعة العلاجية نظام المخدرات هو أحد العوامل المساهمة والسبب الرئيسي لفقدان الكسب غير المشروع 23،24. وتشير هذه الاعتبارات أن المخدرات العلاجية المنزل المتكرر ومراقبة التزام تاكروليماس تركيزات الدم كله قد يكون مفيدا للتأكد من أن المرضى الذين لديهم التعرض تاكروليماس ضمن إطار العلاجي المطلوب في جميع الأوقات. ومع ذلك، والخدمات اللوجستية وتكلفة أكثر تواترا مراقبة الأدوية العلاجية كما هو الممارسة السريرية الحالية 15 باهظة. أحد الأسباب هو أن المريض لديه لمعرفة فصاد أن يكون عينة من الدم الوريدي المطلوب استخلاصها. وقد ظهرت مؤخرا بقع الدم الجافة كمفهوم جذابة 25-28. بعد إصبع بسيطة عصا المريض بجمع قطرة دم على ورقة ورقة فلتر خاصة وبعد أن د بقعة الدمرييد، فإنه يمكن أن ترسل إلى المختبر المركزي لتحليل تاكروليماس وأي مناعة أخرى أن المريض قد تكون آخذة في الوقت الراهن. وقد أصبح هذا ممكنا بفضل تطور فحوصات LC-MS / MS حساسة للغاية ومحددة لتقدير حجم تاكروليماس ومناعة أخرى في حجم الدموية الصغيرة جدا مثل بقع الدم المجفف (عادة 20 ميكرولتر من الدم) 25،29-43. ميزة أخرى هي أنه، استراتيجيات جمع الغازية الحد الأدنى منخفضة عينة حجم مثل بقع الدم المجفف يسهل إلى حد كبير مراقبة الأدوية العلاجية والدراسات الدوائية في الأطفال الصغار 28. وعادة ما تقاس تاكروليماس في EDTA وريدي كله الدم 15. الأسباب التي تاكروليماس يوزع على نطاق واسع في خلايا الدم وأن الدراسات السريرية وأفادت علاقة أفضل بين تركيزات تاكروليماس الحوض الصغير في الدم من البلازما في الأحداث السريرية 15،18. في المقارنة، وتحليل تاويستند crolimus في بقع الدم المجفف على الدم الشعرية التي يختلط مع مصفوفة ورق الترشيح. هذه تحديات من حيث الإذابة التاكروليموس والتدخلات المحتملة مع تحليل LC-MS / MS. هنا نقدم مقايسة إنشاء والتحقق من صحتها على أساس تجانس بقعة الدم المجفف باستخدام خلاط رصاصة في توليفة مع ارتفاع تدفق عينة العمود الانترنت تنظيف الداخلي وتحليل LC-MS / MS. اعتبارا من اليوم، وقد تم بنجاح استخدام هذا الاختبار لتقدير حجم أكثر من خمسة آلاف تاكروليماس المجففة عينات بقعة الدم لرصد الالتزام في التجارب السريرية.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Reference Materials</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tacrolimus</td>
			<td>U.S. Pharmacopeial Convention</td>
			<td>1642802</td>
		</tr>
		<tr>
			<td>D2,13C-Tacrolimus</td>
			<td>Toronto Research Chemicals Inc.</td>
			<td>F370002</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Test Materials</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Red blood cells</td>
			<td>University of Colorado Hospital</td>
			<td>W20091305500 V</td>
		</tr>
		<tr>
			<td>Plasma</td>
			<td>University of Colorado Hospital</td>
			<td>W2017130556300Q</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Solvents</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Acetone CHROMASOLV, HPLC, &#8805; 99,9 %</td>
			<td>Sigma-Aldrich</td>
			<td>439126-4 L</td>
		</tr>
		<tr>
			<td>Acetonitrile Optima LC/ MS, UHPLC- UV</td>
			<td>Thermo Fisher Scientific</td>
			<td>A955-4</td>
		</tr>
		<tr>
			<td>Isopropanol 99.9 %, HPLC</td>
			<td>Fisher Scientific</td>
			<td>BP2632-4</td>
		</tr>
		<tr>
			<td>Methanol Optima LC/ MS</td>
			<td>Thermo Fisher Scientific</td>
			<td>A452-4</td>
		</tr>
		<tr>
			<td>Water Optima LC/ MS, UHPLC- UV</td>
			<td>Thermo Fisher Scientific</td>
			<td>W6-4</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Other Chemicals</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Formic acid</td>
			<td>Thermo Fisher Scientific</td>
			<td>A118P-500</td>
		</tr>
		<tr>
			<td>Phosphate-buffered saline (PBS)</td>
			<td>Sigma-Aldrich</td>
			<td>D8537</td>
		</tr>
		<tr>
			<td>Zinc sulfate</td>
			<td>Thermo Fisher Scientific</td>
			<td>Z68-500</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Laboratory Instruments and Consumables</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>0.5 &#8211; 10 &#181;l pipet, VoluMate LIQUISYSTEMS</td>
			<td>Mettler Toledo</td>
			<td>17008649</td>
		</tr>
		<tr>
			<td>1,5 mL- Eppendorf tube</td>
			<td>Thermo Fisher Scientific</td>
			<td>02-682-550</td>
		</tr>
		<tr>
			<td>10 &#8211; 100 &#181;L pipet, VoluMate LIQUISYSTEMS</td>
			<td>Mettler Toledo</td>
			<td>17008651</td>
		</tr>
		<tr>
			<td>10 &#956;L- pipet tips with filter, sterile</td>
			<td>Neptune</td>
			<td>BT 10XLS3</td>
		</tr>
		<tr>
			<td>100 &#8211; 1000 &#181;l pipet, VoluMate LIQUISYSTEMS</td>
			<td>Mettler Toledo</td>
			<td>17008653</td>
		</tr>
		<tr>
			<td>100 &#956;L- pipet tips with filter, sterile</td>
			<td>Neptune</td>
			<td>BT 100</td>
		</tr>
		<tr>
			<td>1000 &#956;L- pipet tips with filter, sterile</td>
			<td>Multimax</td>
			<td>2940</td>
		</tr>
		<tr>
			<td>2 &#8211; 20 &#181;L pipet, VoluMate LIQUISYSTEMS</td>
			<td>Mettler Toledo</td>
			<td>17008650</td>
		</tr>
		<tr>
			<td>2 mL- Eppendorf tube</td>
			<td>Thermo Fisher Scientific</td>
			<td>02-681-258</td>
		</tr>
		<tr>
			<td>20 &#8211; 200 &#181;L pipet, VoluMate LIQUISYSTEMS</td>
			<td>Mettler Toledo</td>
			<td>17008652</td>
		</tr>
		<tr>
			<td>20 &#956;L- pipet tips with filter, sterile</td>
			<td>GeneMate</td>
			<td>P-1237-20</td>
		</tr>
		<tr>
			<td>200 &#956;L- pipet tips with filter</td>
			<td>Multimax</td>
			<td>2938T</td>
		</tr>
		<tr>
			<td>200 &#956;L- pipet tips with filter, sterile</td>
			<td>Multimax</td>
			<td>2936J</td>
		</tr>
		<tr>
			<td>50 mL- Falcon tube</td>
			<td>BD Falcon</td>
			<td>352070</td>
		</tr>
		<tr>
			<td>300 &#956;L inserts for&#160; HPLC vials</td>
			<td>Phenomenex</td>
			<td>ARO-9973-13</td>
		</tr>
		<tr>
			<td>Balance PR2002</td>
			<td>Mettler Toledo</td>
			<td>1117050723</td>
		</tr>
		<tr>
			<td>Balances AX205 Delta Range</td>
			<td>Mettler Toledo</td>
			<td>1119343379</td>
		</tr>
		<tr>
			<td>Bullet Blender Homogenizer</td>
			<td>Next Advance</td>
			<td>BBX24</td>
		</tr>
		<tr>
			<td>Centrifuge Biofuge Fresco</td>
			<td>Heraeus</td>
			<td>290395</td>
		</tr>
		<tr>
			<td>Disposable Wipes</td>
			<td>PDI</td>
			<td>Q55172</td>
		</tr>
		<tr>
			<td>Glass v ials, 4 mL</td>
			<td>Thermo Fisher Scientific</td>
			<td>14-955-334</td>
		</tr>
		<tr>
			<td>Glass vials, 20 mL</td>
			<td>Thermo Fisher Scientific</td>
			<td>B7800-20</td>
		</tr>
		<tr>
			<td>Gloves, nitrile</td>
			<td>Titan Brand Gloves</td>
			<td>44-100S</td>
		</tr>
		<tr>
			<td>HPLC vials, 9 mm, 2 mL, clear</td>
			<td>Phenomenex</td>
			<td>ARO- 9921-13</td>
		</tr>
		<tr>
			<td>Lids for HPLC vials</td>
			<td>Phenomenex</td>
			<td>ARO- 8952-13-B</td>
		</tr>
		<tr>
			<td>Needle, 18G 1.5</td>
			<td>Precision Glide</td>
			<td>305196</td>
		</tr>
		<tr>
			<td>Rack for Eppendorf tubes</td>
			<td>Thermo Fisher Scientific</td>
			<td>03-448-11</td>
		</tr>
		<tr>
			<td>Rack for HPLC Vials</td>
			<td>Thermo Fisher Scientific</td>
			<td>05-541-29</td>
		</tr>
		<tr>
			<td>Steel beads 0.9 &#8211; 2 mm</td>
			<td>Next Advance</td>
			<td>SSB14B</td>
		</tr>
		<tr>
			<td>Storage boxes for freezers / refrigerators</td>
			<td>Thermo Fisher Scientific</td>
			<td>03-395-464</td>
		</tr>
		<tr>
			<td>Standard multi-tube vortexer</td>
			<td>VWR Scientific Products</td>
			<td>658816-115</td>
		</tr>
		<tr>
			<td>Whatman Paper, 903 Protein Saver US 100/PK</td>
			<td>GE Whatman&#160;</td>
			<td>2016-05</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>HPLC Equipment and Columns</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Autosampler</td>
			<td>CTC PAL&#160;</td>
			<td>PAL.HTCABIx1</td>
		</tr>
		<tr>
			<td>Binary pump, Agilent 1260 Infinity</td>
			<td>Agilent Technologies</td>
			<td>1260 G1312B</td>
		</tr>
		<tr>
			<td>Binary pump, Agilent 1290 Infinity</td>
			<td>Agilent Technologies</td>
			<td>1290 G4220A</td>
		</tr>
		<tr>
			<td>Micro vacuum degasser, Agilent 1260</td>
			<td>Agilent Technologies</td>
			<td>1260 G13798</td>
		</tr>
		<tr>
			<td>Column oven,&#160; Agilent 1290 with 2 position&#160;</td>
			<td>Agilent Technologies</td>
			<td>1290 G1216C</td>
		</tr>
		<tr>
			<td>Thermostated column compartment with integrated 6 port switching valve</td>
			<td>Agilent Technologies</td>
			<td>1290 G1316C</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>HPLC pre-column cartridge, Zorbax XDB C8 (5 &#181;m particle size), 4.6 &#183; 12.5 mm</td>
			<td>Phenomenex</td>
			<td>820950-926</td>
		</tr>
		<tr>
			<td>HPLC analytical column, Zorbax Eclipse-XDB-C8 (5 &#181;m particle size), 4.6 &#183; 150 mm</td>
			<td>Phenomenex</td>
			<td>993967-906</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tandem Mass Spectrometer</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>API5000 MS/MS with TurboIonspray source</td>
			<td>AB Sciex</td>
			<td>4364257</td>
		</tr>
		<tr>
			<td>Mass spectrometry software</td>
			<td>AB Sciex</td>
			<td>Analyst 1.5.1</td>
		</tr>
	</tbody>
</table>

quantification of the immunosuppressant tacrolimus on dried blood spots using lc-ms/ms

وتاكروليموس الكالسينيورين المانع هو حجر الزاوية في معظم بروتوكولات العلاج المثبطة للمناعة بعد زرع الأعضاء الصلبة في الولايات المتحدة. تاكروليماس هو ضيق مؤشر المخدرات العلاجية ومثل يتطلب مراقبة الأدوية العلاجية وتعديل الجرعة بناء على تركيزات كلها في الحوض الصغير الدم. لتسهيل المخدرات العلاجية الداخل ومراقبة الالتزام، وجمع من بقع الدم المجفف هو مفهوم جذابا. بعد عصا إصبع، والمريض بجمع قطرة دم على ورق الترشيح في المنزل. بعد تجفيفها الدم، وإرساله إلى المختبر التحليلي حيث كميا تاكروليماس باستخدام السائل عالي الأداء اللوني، جنبا إلى جنب قياس الطيف الكتلي (HPLC-MS / MS) في توليفة مع يدوية بسيطة من البروتين هطول خطوة واستخراج العمود الانترنت. لتحليل تاكروليماس، واللكم 6 ملم القرص من مركز المشبعة من بقعة الدم. والمتجانس بقعة الدم باستخدام رصاصة خلاط لالثانية ثم يتم عجلت البروتينات مع الميثانول / 0.2 M ZnSO 4 التي تحتوي على مستوى D الداخلي 2، 13 C-تاكروليماس. بعد vortexing لوالطرد المركزي، ويتم حقن 100 ميكرولتر من طاف في عمود استخراج الانترنت وغسلها مع 5 مل / دقيقة 0.1 الفورميك حمض / الأسيتونتريل (7: 3، ت: ت) لمدة 1 دقيقة. الآخرة، يتم تنشيط صمام التحويل وتحليلها يتم مسح الظهر على العمود التحليلي (وفصلها باستخدام 0.1٪ حمض الفورميك / الأسيتونتريل التدرج). وكميا تاكروليماس في وضع إيجابي متعدد رد فعل (MRM) باستخدام مطياف الكتلة جنبا إلى جنب. فحص خطي 1-50 نانوغرام / مل. التباين بين فحص (3.6٪ -6.1٪) والدقة (91.7٪ -101.6٪) وفقا لتقييم أكثر من 20 أيام تلبية معايير القبول. متوسط ​​الانتعاش الاستخراج 95.5٪. لا توجد صلة المرحل، التدخلات المصفوفة والآثار المصفوفة. تاكروليماس مستقر في بقع الدم الجافة في RT وفي +4 درجة مئوية لمدة 1 أسبوع. العينات المستخرجة فيالاوتوماتيكى مستقرة في +4 درجة مئوية لمدة 72 ساعة على الأقل.

الاستشرابية أيون التمثيلية لعينة فارغة، ارتفعت عينة على الحد الأدنى من تقدير وعينة المرضى في الشكل 3. منحنيات المعايرة وكان الحد الأدنى للكشف 0.5 نانوغرام / مل وكان الحد الأد...

Watch this Scientific Journal Video about Quantification of the Immunosuppressant Tacrolimus on Dried Blood Spots Using LC-MS/MS at JoVE.com

Quantification of the Immunosuppressant Tacrolimus on Dried Blood Spots Using LC-MS/MS

Here we describe a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) assay to quantify the immunosuppressant tacrolimus in dried blood spots using a simple manual protein precipitation step and online column extraction.

الكمي للمناعة tacrolimus على وبقع الدم الجافة عن طريق LC-MS / MS

The calcineurin inhibitor tacrolimus is the cornerstone of most immunosuppressive treatment protocols after solid organ transplantation in the United ...

quantification-immunosuppressant-tacrolimus-on-dried-blood-spots

Research

JoVE Journal

Medicine

16.8K Views.  University of Colorado, Anschutz Medical Campus. Here we describe a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) assay to quantify the immunosuppressant tacrolimus in dried blood spots using a simple manual protein precipitation step and online column extraction.

Video: Quantification of the Immunosuppressant Tacrolimus on Dried Blood Spots Using LC-MS/MS

A Contusive Model of Unilateral Cervical Spinal Cord Injury Using the Infinite Horizon Impactor

While the majority of human spinal cord injuries occur in the cervical spinal cord, the vast majority of laboratory research employs animal models of spinal cord injury (SCI) in which the thoracic spinal cord is injured. Additionally, because most human cord injuries occur as the result of blunt, non-penetrating trauma (e.g. motor vehicle accident, sporting injury) where the spinal cord is violently struck by displaced bone or soft tissues, the majority of SCI researchers are of the opinion that the most clinically relevant injury models are those in which the spinal cord is rapidly contused.1 Therefore, an important step in the preclinical evaluation of novel treatments on their way to human translation is an assessment of their efficacy in a model of contusion SCI within the cervical spinal cord. Here, we describe the technical aspects and resultant anatomical and behavioral outcomes of an unilateral contusive model of cervical SCI that employs the Infinite Horizon spinal cord injury impactor.
Sprague Dawley rats underwent a left-sided unilateral laminectomy at C5. To optimize the reproducibility of the biomechanical, functional, and histological outcomes of the injury model, we contused the spinal cords using an impact force of 150 kdyn, an impact trajectory of 22.5&deg; (animals rotated at 22.5&deg;), and an impact location off of midline of 1.4 mm. Functional recovery was assessed using the cylinder rearing test, horizontal ladder test, grooming test and modified Montoya's staircase test for up to 6 weeks, after which the spinal cords were evaluated histologically for white and grey matter sparing.
The injury model presented here imparts consistent and reproducible biomechanical forces to the spinal cord, an important feature of any experimental SCI model. This results in discrete histological damage to the lateral half of the spinal cord which is largely contained to the ipsilateral side of injury. The injury is well tolerated by the animals, but does result in functional deficits of the forelimb that are significant and sustained in the weeks following injury. The cervical unilateral injury model presented here may be a resource to researchers who wish to evaluate potentially promising therapies prior to human translation.

A reliable and repeatable way to produce a cervical unilateral spinal cord injury using the Infinite Horizon impactor is described. The method takes advantage of a custom designed frame and clamp to stabilize the spine. The standardized procedure and biomechanical injury parameters result in sufficient and sustained injuries.

نموذج من جانب واحد راض عنق الرحم لاصابة النخاع الشوكي باستخدام المتصادم الأفق اللانهائي

While the majority of human spinal cord injuries occur in the cervical spinal cord, the vast majority of laboratory research employs animal models of ...

Formation of Human Prostate Epithelium Using Tissue Recombination of Rodent Urogenital Sinus Mesenchyme and Human Stem Cells

Progress in prostate cancer research is severely limited by the availability of human-derived and hormone-na&iuml;ve model systems, which limit our ability to understand genetic and molecular events underlying prostate disease initiation. Toward developing better model systems for studying human prostate carcinogenesis, we and others have taken advantage of the unique pro-prostatic inductive potential of embryonic rodent prostate stroma, termed urogenital sinus mesenchyme (UGSM). When recombined with certain pluripotent cell populations such as embryonic stem cells, UGSM induces the formation of normal human prostate epithelia in a testosterone-dependent manner. Such a human model system can be used to investigate and experimentally test the ability of candidate prostate cancer susceptibility genes at an accelerated pace compared to typical rodent transgenic studies. Since Human embryonic stem cells (hESCs) can be genetically modified in culture using inducible gene expression or siRNA knock-down vectors prior to tissue recombination, such a model facilitates testing the functional consequences of genes, or combinations of genes, which are thought to promote or prevent carcinogenesis.
The technique of isolating pure populations of UGSM cells, however, is challenging and learning often requires someone with previous expertise to personally teach. Moreover, inoculation of cell mixtures under the renal capsule of an immunocompromised host can be technically challenging. Here we outline and illustrate proper isolation of UGSM from rodent embryos and renal capsule implantation of tissue mixtures to form human prostate epithelium. Such an approach, at its current stage, requires in vivo xenografting of embryonic stem cells; future applications could potentially include in vitro gland formation or the use of induced pluripotent stem cell populations (iPSCs).

To unravel the earliest molecular mechanisms underlying prostate cancer initiation, novel and innovative human model systems and approaches are desperately needed. The potential of pre-prostatic urogenital sinus mesenchyme (UGSM) to induce pluripotent stem cell populations to form human prostate epithelium is a powerful experimental tool in prostate research.

تشكيل الظهارة البروستاتا الذي يصيب الانسان عن طريق إعادة التركيب الأنسجة من القوارض البولي التناسلي اللحمة المتوسطة الجيوب الأنفية والخلايا الجذعية البشرية

Progress in prostate cancer research is severely  limited by the availability of human-derived and hormone-na&iuml;ve model systems,  which limit our ...

Dried Blood Spot Collection of Health Biomarkers to Maximize Participation in Population Studies

Biomarkers are directly-measured biological indicators of disease, health, exposures, or other biological information. In population and social sciences, biomarkers need to be easy to obtain, transport, and analyze. Dried Blood Spots meet this need, and can be collected in the field with high response rates. These elements are particularly important in longitudinal study designs including interventions where attrition is critical to avoid, and high response rates improve the interpretation of results. Dried Blood Spot sample collection is simple, quick, relatively painless, less invasive then venipuncture, and requires minimal field storage requirements (i.e.&#160;samples do not need to be immediately frozen and can be stored for a long period of time in a stable freezer environment before assay). The samples can be analyzed for a variety of different analytes, including cholesterol, C-reactive protein, glycosylated hemoglobin, numerous cytokines, and other analytes, as well as provide genetic material. DBS collection is depicted as employed in several recent studies.

Biomarkers are directly-measured biological indicators of disease or health. In population and social sciences, biomarkers need to be easy to obtain, transport, and analyze. Dried Blood Spot (DBS) collection meets this need, can be collected in the field with high response rates&#160;and analyzed for a variety of biomarkers.

المجففة الدم بقعة مجموعة من المؤشرات الحيوية الصحية لتحقيق أقصى قدر من المشاركة في الدراسات السكانية

Biomarkers are directly-measured biological indicators of disease, health, exposures, or other biological information. In population and social sciences, ...

Absolute Quantification of A&#946;1-42 in CSF Using a Mass Spectrometric Reference Measurement Procedure

Alzheimer's disease (AD) is the most common neurodegenerative disease among the elderly and accounts for 60-80% of all cases of dementia. Currently, the diagnosis of AD is based on cognitive tests and mental state exams, but the peptide amyloid-beta (A&#946;) in cerebrospinal fluid (CSF) is increasingly used in clinical trials and settings. As for most protein and peptide biomarkers, quantification is performed using antibody-based techniques, such as enzyme-linked immunosorbent assay (ELISA). However, intra- and inter-laboratory variability in these assays hamper its use as a diagnostic marker in clinical routine.
An antibody-independent Reference Measurement Procedure (RMP) was developed based on solid-phase extraction (SPE) and liquid chromatography (LC)-tandem mass spectrometry (MS/MS), where stable, isotope-labeled A&#946; peptides were used as internal standards, enabling absolute quantification. A high-resolution quadrupole-orbitrap hybrid instrument was used for the measurements. The method allows for the quantification of CSF A&#946;1-42 between 150-4,000 pg/mL.

Absolute Quantification of A&amp;#946;&lt;sub&gt;1-42&lt;/sub&gt; in CSF Using a Mass Spectrometric Reference Measurement Procedure

A reference measurement procedure for the absolute quantification of A&#946;1-42 in human CSF based on solid-phase extraction and liquid chromatography tandem mass spectrometry is described.

الكمي المطلق للAβ<sub&gt; 1-42</sub&gt; في السائل الدماغي الشوكي عن طريق مرجع إجراء قياس كتلة الطيف

Alzheimer's disease (AD) is the most common neurodegenerative disease among the elderly and accounts for 60-80% of all cases of dementia. Currently, the ...

Optimized LC-MS/MS Method for the High-throughput Analysis of Clinical Samples of Ivacaftor, Its Major Metabolites, and Lumacaftor in Biological Fluids of Cystic Fibrosis Patients

Defects in the cystic fibrosis trans-membrane conductance regulator (CFTR) are the cause of cystic fibrosis (CF), a disease with life-threatening pulmonary manifestations. Ivacaftor (IVA) and ivacaftor-lumacaftor (LUMA) combination are two new breakthrough CF drugs that directly modulate the activity and trafficking of the defective CFTR-protein. However, there is still a dearth of understanding on pharmacokinetic/pharmacodynamic parameters and the pharmacology of ivacaftor and lumacaftor. The HPLC-MS technique for the simultaneous analysis of the concentrations of ivacaftor, hydroxymethyl-ivacaftor, ivacaftor-carboxylate, and lumacaftor in biological fluids in patients receiving standard ivacaftor or ivacaftor-lumacaftor combination therapy has previously been developed by our group and partially validated to FDA standards. However, to allow the high-throughput analysis of a larger number of patient samples, our group has optimized the reported method through the use of a smaller pore size reverse-phase chromatography column (2.6 &#181;m, C8 100 &#197;; 50 x 2.1 mm) and a gradient solvent system (0-1 min: 40% B; 1-2 min: 40-70% B; 2-2.7 min: held at 70% B; 2.7-2.8 min: 70-90% B; 2.8-4.0 min: 90% B washing; 4.0-4.1 min: 90-40% B; 4.1-6.0 min: held at 40% B) instead of an isocratic elution. The goal of this study was to reduce the HPLC-MS analysis time per sample dramatically from ~15 min to only 6 min per sample, which is essential for the analysis of a large amount of patient samples. This expedient method will be of considerable utility for studies into the exposure-response relationships of these breakthrough CF drugs.

Ivacaftor and ivacaftor-lumacaftor combination are two new CF drugs. However, there is still a dearth of understanding on their PK/PD and pharmacology. We present an optimized HPLC-MS technique for the simultaneous analysis of ivacaftor and its major metabolites, and lumacaftor.

أسلوب LC-MS/MS الأمثل لتحليل العينات السريرية إيفاكافتور، والايضات الرئيسية، ولوماكافتور في السوائل البيولوجية لمرضى التليف الكيسي الفائق

Defects in the cystic fibrosis trans-membrane conductance regulator (CFTR) are the cause of cystic fibrosis (CF), a disease with life-threatening ...

A Chronic Cardiac Ischemia Model in Swine Using an Ameroid Constrictor

Cardiovascular disease remains the number one cause of mortality in the United States. There are numerous approaches to treating these diseases, but regardless of the approach, an in vivo model is needed to test each treatment. The pig is one of the most used large animal models for cardiovascular disease. Its heart is very similar in anatomy and function to that of a human. The ameroid placement technique creates an ischemic area of the heart, which has many useful applications in studying myocardial infarction. This model has been used for surgical research, pharmaceutical studies, imaging techniques, and cell therapies.
There are several ways of inducing an ischemic area in the heart. Each has its advantages and disadvantages, but the placement of an ameroid constrictor remains the most widely used technique. The main advantages to using the ameroid are its prevalence in existing research, its availability in various sizes to accommodate the anatomy and size of the vessel to be constricted, the surgery is a relatively simple procedure, and the post-operative monitoring is minimal, since there are no external devices to maintain. This paper provides a detailed overview of the proper technique for the placement of the ameroid constrictor.

The purpose of this protocol is to demonstrate the placement of a delayed constricting device (an ameroid constrictor) around a coronary artery in a swine model. This device creates an ischemic area of the heart that is useful for studying new diagnostic imaging techniques and new methods of treatment.

نموذج الاسكيمية القلب مزمنة في الخنازير باستخدام العاصرة أميرويد

Cardiovascular disease remains the number one cause of mortality in the United States. There are numerous approaches to treating these diseases, but ...

Improved Method for the Establishment of an In Vitro Blood-Brain Barrier Model Based on Porcine Brain Endothelial Cells

The aim of this protocol presents an optimized procedure for the purification and cultivation of pBECs and to establish in vitro blood-brain barrier (BBB) models based on pBECs in mono-culture (MC), MC with astrocyte-conditioned medium (ACM), and non-contact co-culture (NCC) with astrocytes of porcine or rat origin. pBECs were isolated and cultured from fragments of capillaries from the brain cortices of domestic pigs 5-6 months old. These fragments were purified by careful removal of meninges, isolation and homogenization of grey matter, filtration, enzymatic digestion, and centrifugation. To further eliminate contaminating cells, the capillary fragments were cultured with puromycin-containing medium. When 60-95% confluent, pBECs growing from the capillary fragments were passaged to permeable membrane filter inserts and established in the models. To increase barrier tightness and BBB characteristic phenotype of pBECs, the cells were treated with the following differentiation factors: membrane permeant 8-CPT-cAMP (here abbreviated cAMP), hydrocortisone, and a phosphodiesterase inhibitor, RO-20-1724 (RO). The procedure was carried out over a period of 9-11 days, and when establishing the NCC model, the astrocytes were cultured 2-8 weeks in advance. Adherence to the described procedures in the protocol has allowed the establishment of endothelial layers with highly restricted paracellular permeability, with the NCC model showing an average transendothelial electrical resistance (TEER) of 1249 &#177; 80 &#937; cm2, and paracellular permeability (Papp) for Lucifer Yellow of 0.90 10-6 &#177; 0.13 10-6 cm sec-1 (mean &#177; SEM, n=55). Further evaluation of this pBEC phenotype showed good expression of the tight junctional proteins claudin 5, ZO-1, occludin and adherens junction protein p120 catenin. The model presented can be used for a range of studies of the BBB in health and disease and, with the highly restrictive paracellular permeability, this model is suitable for studies of transport and intracellular trafficking.

Improved Method for the Establishment of an In Vitro Blood-Brain Barrier Model Based on Porcine Brain Endothelial Cells

The aim of the protocol is to present an optimized procedure for the establishment of an in vitro blood-brain barrier (BBB) model based on primary porcine brain endothelial cells (pBECs). The model shows high reproducibility, high tightness, and is suitable for studies of transport and intracellular trafficking in drug discovery.

تحسين أسلوب لإنشاء في المختبر حاجز الدم – المخ نموذج استناداً إلى خلايا المخ الخنزيري بطانية

The aim of this protocol presents an optimized procedure for the purification and cultivation of pBECs and to establish in vitro blood-brain barrier (BBB) ...

Evaluation of Cerebral Blood Flow Autoregulation in the Rat Using Laser Doppler Flowmetry

When investigating the body&#39;s mechanisms for regulating cerebral blood flow, a relative measurement of microcirculatory blood flow can be obtained using laser Doppler flowmetry (LDF). This paper demonstrates a closed skull preparation that allows cerebral blood flow to be assessed without penetrating the skull or installing a chamber or cerebral window. To evaluate autoregulatory mechanisms, a model of controlled blood pressure reduction via graded hemorrhage can be utilized while simultaneously employing LDF. This enables the real time tracking of the relative changes in the blood flow in response to reductions in arterial blood pressure produced by the withdrawal of circulating blood volume. This paradigm is a valuable approach to study cerebral blood flow autoregulation during reductions in arterial blood pressure and, with minor modifications in the protocol, is also valuable as an experimental model of hemorrhagic shock. In addition to evaluating autoregulatory responses, LDF can be used to monitor the cortical blood flow when investigating metabolic, myogenic, endothelial, humoral, or neural mechanisms that regulate cerebral blood flow and the impact of various experimental interventions and pathological conditions on cerebral blood flow.

This article demonstrates the use of laser Doppler flowmetry to evaluate the ability of the cerebral circulation to autoregulate its blood flow during reductions in arterial blood pressure.

تقييم التنظيم التلقائي لتدفق الدم الدماغي في الفئران باستخدام الليزر دوبلر الجريان

When investigating the body&#39;s mechanisms for regulating cerebral blood flow, a relative measurement of microcirculatory blood flow can be obtained ...

Validated LC-MS/MS Panel for Quantifying 11 Drug-Resistant TB Medications in Small Hair Samples

Drug resistant-tuberculosis (DR-TB) is a growing public health threat, and assessment of therapeutic drug levels may have important clinical benefits. Plasma drug levels are the current gold standard assessment, but require phlebotomy and a cold chain, and capture only very recent adherence. Our method uses hair, a matrix that is easily collected and reflective of long-term adherence, to test for 11 anti-TB medications. Previous work by our group shows that antiretroviral drug levels in hair are associated with HIV outcomes. Our method for DR-TB drugs uses 2 mg of hair (3 cm proximal to the root), which is pulverized and extracted in methanol. Samples are analyzed with a single LC-MS/MS method, quantifying 11 drugs in a 16 min run. Lower limits of quantification (LLOQs) for the 11 drugs range from 0.01 ng/mg to 1 ng/mg. Drug presence is confirmed by comparing ratios of two mass spectrometry transitions. Samples are quantified using the area ratio of the drug to the deuterated, 15N-, or 13C-labeled drug isotopologue. We used a calibration curve ranging from 0.001-100 ng/mg. Application of the method to a convenience sample of hair samples collected from DR-TB patients on directly observed therapy (DOT) indicated drug levels in hair within the linear dynamic range of nine of the eleven drugs (isoniazid, pyrazinamide, ethambutol, linezolid, levofloxacin, moxifloxacin, clofazimine, bedaquiline, pretomanid). No patient was on prothionamide, and the measured levels for ethionamide were close to its LLOQ (with further work instead examining the suitability of ethionamide&#8217;s metabolite for monitoring exposure). In summary, we describe the development of a multi-analyte panel for DR-TB drugs in hair as a technique for therapeutic drug monitoring during drug-resistant TB treatment.

Current methods of analyzing patients&#8217; adherence to complex drug resistant-tuberculosis (DR-TB) regimens can be inaccurate and resource-intensive. Our method analyzes hair, an easily collected and stored matrix, for concentrations of 11 DR-TB medications. Using LC-MS/MS, we can determine sub-nanogram drug levels that can be utilized to better understand drug adherence.

لوحة LC-MS/MS المعتمدة لقياس 11 دواءً مقاومًا للأدوية في عينات الشعر الصغيرة

Drug resistant-tuberculosis (DR-TB) is a growing public health threat, and assessment of therapeutic drug levels may have important clinical benefits. ...

Human Fetal Blood Flow Quantification with Magnetic Resonance Imaging and Motion Compensation

Magnetic resonance imaging (MRI) is an important tool for the clinical assessment of cardiovascular morphology and heart function. It is also the recognized standard-of-care for blood flow quantification based on phase contrast MRI. While such measurement of blood flow has been possible in adults for decades, methods to extend this capability to fetal blood flow have only recently been developed.
Fetal blood flow quantification in major vessels is important for monitoring fetal pathologies such as congenital heart disease (CHD) and fetal growth restriction (FGR). CHD causes alterations in the cardiac structure and vasculature that change the course of blood in the fetus. In FGR, the path of blood flow is altered through the dilation of shunts such that the oxygenated blood supply to the brain is increased. Blood flow quantification enables assessment of the severity of the fetal pathology, which in turn allows for suitable&#160;in utero&#160;patient management and planning for postnatal care.
The primary challenges of applying phase contrast MRI to the human fetus include small blood vessel size, high fetal heart rate, potential MRI data corruption due to maternal respiration, unpredictable fetal movements, and lack of conventional cardiac gating methods to synchronize data acquisition. Here, we describe recent technical developments from our lab that have enabled the quantification of fetal blood flow using phase contrast MRI, including advances in accelerated imaging, motion compensation, and cardiac gating.

Here we present a protocol for measuring fetal blood flow rapidly with MRI and retrospectively performing motion correction and cardiac gating.