Establishment and Fractionation of Metastatic Axillary Lymph Node Cell Suspension for Determination of Protein Expression Levels of Nuclear cFOS and Cytosolic TGFβ1 from Breast Cancer Patients

Background. Metastatic Axillary Lymph Node (mALN) status is currently the most important prognostic factor in the management of primary breast cancer (BC). Thus, development of specimens which enable identification of new mALN markers, involved in the progression of the disease, are of considerable interest. The specific aim of this work was to describe the method of establishment of Metastatic Axillary Nodal Cell Suspension and its fractionation, termed Fractionated Nodal Cell Suspension (FNCS), into nuclear and cytosolic extracts to enable determination of protein expression levels of nuclear cFOS and cytosolic Transforming Growth Factor β1 (TGFβ1) in BC patients. Results. To standardize the procedure, HeLa cells were successfully fractionated into nuclear/cytosolic extracts with confirmed presence of nuclear cFOS and cytosolic TGFβ1 proteins. Subsequently, the ALN Cell Suspension specimens were obtained and further fractionated from a pilot sample of six ALN tissue pairs, mALN versus autologous normal ALN (nALN), dissected from invasive BC patients. The mALN results revealed statistically significant overexpression in nuclear cFOS and cytosolic TGFβ1 protein levels, which was proportional to the respective values of mALN diameter of tumor deposits. Conclusions. Detailed protocol for establishment and fractionation of mALN cell suspension specimens, termed FNCS, into nuclear and cytosolic extracts is here described for the first time. This approach might be a convenient ex vivo model for simultaneous analysis of protein, RNA and DNA biomarkers from nuclear/cytosolic extracts of the same mALN tissue sample. It might have potential to enable, in the age of genomics and personalized medicine, an identification of novel mALN biomarkers and thus improve the screening, diagnosis and prognosis of invasive BC.

PERAN SEL NODUS SINOATRIAL SEBAGAI PENGATUR IRAMA JANTUNG

The heart has a special system that provokes impulses and conducts these in the whole heart, resulting in a contraction. Normally, the sinoatrial node (SA-node) functions as a natural pace maker of the heart which plays a very important role in heart beat regulation. In the SA-node, there are two kinds of cells: P cell, a specialized nodal cell; and T cell, the transition cell. The P cell, the main SA-nodal cell, is a small cell and contains a small amount of sarcoplasma reticulum, mitochondria, and myofilaments. The T cell has a larger size, and contains more mitochondria than the P cell. The action potential in the SA-node begins in the middle of the node (P cells), spreads to the periphery (T cells), and then gets into the atrial muscle tissues. P cells provoke a slower and lower action potential than that of atrial muscles and their surroundings; meanwhile the T cells provoke a faster and larger action potential. In the P cells, the upstroke action potential occurs slowly since these cells contain a small number of Na+ channels, or none. Although Ca2+ L-type channels are responsible for the upstroke action potential in the P cells, the Na+ channels in the T cells still play some important roles. Keywords: sinoatrial node, P cell, T cell, ion channels. Abstrak: Jantung dilengkapi dengan suatu sistem khusus untuk membangkitkan impuls-impuls dan menghantarkannya dengan cepat ke seluruh jantung sehingga terjadi kontraksi otot jantung. Dalam keadaan normal, nodus sinoatrial (SA) di atrium kanan berperan sebagai pacu alami jantung dan berperan penting dalam mengatur irama jantung. Pada nodus SA terdapat sel P (sel-sel khas nodal) dan sel T (sel transisi). Sel P merupakan sel utama dalam nodus sinoatrial, berukuran kecil, dan hanya mengandung sedikit retikulum sarkoplasma, mitokondria dan miofilamen. Sel T berukuran lebih besar dan mempunyai mitokondria yang lebih banyak dari pada sel P. Potensial aksi pada nodus SA dimulai di daerah tengah nodus SA (sel P), kemudian merambat ke daerah tepi (sel T), lalu masuk ke dalam jaringan otot atrium. Sel P menimbulkan potensial aksi yang lebih lambat dan kecil dibandingkan potensial aksi pada otot atrium dan sekitarnya, sedangkan pada sel T ditemukan potensial aksi yang lebih cepat dan lebih besar. Pada sel P, potensial aksi upstroke (depolarisasi) terjadi lambat karena sel ini hanya mengandung sedikit saluran Na+, bahkan biasanya tidak ada. Meskipun saluran Ca2+ L-type (tipe lambat) yang bertanggung jawab dalam potensial aksi upstroke pada sel P, pada sel T saluran Na+ tetap berperan penting.13 Kata kunci: nodus sinoatrial, sel P, sel T, saluran ion.

Modeling and Simulation of Opposite Type MATA Using MEMS Nodal Cell Library

In MEMS nodal analysis method, more available libraries of nodal models are needed. By analyzing the mathematic model and the equivalent model of the electro-thermal-mechanical beam, this paper shows the steps of building a library of a nodal element for HSPICE. Then the cell library is used to simulate the opposite type micro-array thermal actuator (MATA). At last it shows the DC sweep performance and the transient performance of opposite type MATA. In this paper, to verify the reusability of the beam cell, opposite type MATA is all consisted of the electro-thermal-mechanical beam cell in library.

Electrotonic modulation of electrical activity in rabbit atrioventricular node myocytes

Electrotonic effects of electrically coupling atrioventricular (AV) nodal cells to each other and to real and passive models of atrial and ventricular cells were studied using a technique that does not require functional gap junctions. Membrane potential was measured in each cell using suction pipettes. Mutual entrainment of two spontaneously firing AV nodal cells was achieved with a junctional resistance (Rj) of 500 M omega, which corresponds to only 39 junctional channels, assuming a single-channel conductance of 50 pS. Coupling of AV nodal and atrial cells at Rj of 50 M omega caused hyperpolarization of the nodal cell, decreasing its action potential duration and either slowing or blocking diastolic depolarization in the AV node myocyte. Opposite changes occurred in the atrial action potential. When AV nodal and ventricular cells were coupled at Rj of 50 M omega, nodal diastolic potential was markedly hyperpolarized and diastolic depolarization was completely blocked with little change in ventricular diastolic potential. However, coupling did elicit marked changes in the action potential duration of both cells, with prolongation in the nodal cell and shortening in the ventricular cell. Nodal maximum upstroke velocity was increased by both atrial and ventricular coupling, as expected from the hyperpolarization that occurred. With an Rj of 50 M omega, spontaneous firing was blocked in all single AV nodal pacemaker cells during coupling to a real or passive model of an atrial or ventricular cell. These results demonstrate that action potential formation and waveform in a single AV nodal cell is significantly affected by electrical coupling to other myocytes.