ABSTRACT
The inner nuclear envelope (NE) proteins interact with the nuclear lamina and participate in the architectural compartmentalization of chromosomes. The association of NE proteins with DNA contributes to the spatial rearrangement of chromosomes and their gene expression. Sun1 is an inner nuclear membrane (INM) protein that locates to telomeres and anchors chromosome movement in the prophase of meiosis. Here, we have created Sun1-/- mice and have found that these mice are born and grow normally but are reproductively infertile. Detailed molecular analyses showed that Sun1-/- P14 testes are repressed for the expression of reproductive genes and have no detectable piRNA. These findings raise a heretofore unrecognized role of Sun1 in the selective gene expression of coding and non-coding RNAs needed for gametogenesis.
Subject(s)
Meiosis , Microtubule-Associated Proteins/metabolism , RNA, Untranslated/genetics , Reproduction/genetics , Animals , Argonaute Proteins , Gene Expression Regulation, Developmental , Male , Mice , Mice, Knockout , Microtubule-Associated Proteins/deficiency , Microtubule-Associated Proteins/genetics , Oligonucleotide Array Sequence Analysis , Proteins/genetics , Proteins/metabolism , Spermatogenesis , Testis/metabolismABSTRACT
The CentriMag left ventricular assist system can be used for perioperative or postcardiotomy circulatory support of the failing heart. The device resides at the patient's bedside, and the cannulae are usually inserted through a midline sternotomy, with the inflow cannula in the left ventricle or right superior pulmonary vein and the outflow cannula in the aorta. In a patient whose chest has been closed and who has a delayed need for temporary mechanical support, a less invasive method of left ventricular assist device cannula insertion is preferred. In these cases, the CentriMag cannulae can be inserted through a right minithoracotomy with the inflow cannula in the right superior pulmonary vein and the outflow cannula in the aorta, with no heparinization. Herein, we describe this approach in a patient who experienced postcardiotomy cardiogenic shock after aortocoronary bypass surgery. This technique may facilitate ambulation and recovery in selected patients.
Subject(s)
Cardiac Catheterization/methods , Heart-Assist Devices , Prosthesis Implantation/methods , Shock, Cardiogenic/therapy , Coronary Artery Bypass/adverse effects , Female , Humans , Middle Aged , Shock, Cardiogenic/etiology , ThoracotomyABSTRACT
BACKGROUND: Implantation of a HeartMate II or a Jarvik 2000 FlowMaker left ventricular assist system (LVAS) usually involves a mid-line sternotomy and the use of cardiopulmonary bypass (CPB). In patients with numerous co-morbid conditions, however, surgical trauma may be minimized by implanting the LVAS via a minimally invasive approach, preferably without CPB. METHODS: In 6 patients with end-stage heart failure and other serious co-morbidities, we implanted a HeartMate II (n = 3) or a Jarvik 2000 FlowMaker (n = 3) LVAS via a right mini-thoracotomy and a left sub-costal incision. Patients included 3 men and 3 women with a mean age of 41 years. In 3 cases, the LVAS was implanted without CPB. RESULTS: After a mean follow-up period of 6 months, 5 patients are alive and well and on the transplant waiting list. Seven months after LVAS implantation, the remaining patient developed a hemorrhagic stroke necessitating Jarvik 2000 replacement with a new pump of the same type. CONCLUSIONS: In this small series, the combined sub-costal and mini-thoracotomy incision proved safe and technically feasible. It may be useful for other LVAS candidates who have serious co-morbidities that preclude traditional implant operations.
Subject(s)
Heart Failure/surgery , Heart-Assist Devices , Minimally Invasive Surgical Procedures , Adult , Blood Transfusion , Cerebral Hemorrhage/complications , Feasibility Studies , Female , Follow-Up Studies , Heart Failure/complications , Humans , Male , Middle Aged , Minimally Invasive Surgical Procedures/methods , Postoperative Care , Postoperative Complications/surgery , Reoperation , Stroke/etiology , Stroke/surgery , ThoracotomyABSTRACT
In 2 patients with the Jarvik 2000 left ventricular assist device (LVAD), we assessed left ventricular systolic function through pressure-volume loops and E(max) at the beginning and end of the support period to potentially predict the possibility of pump removal without transplantation. Immediately before LVAD implantation and explantation, pressure and volume measurements were made with catheters and echocardiography, respectively, the E(max) being calculated from the slope of the pressure-volume loops, and the left ventricular ejection fraction (LVEF) being estimated by echocardiography. Transplantation was performed after 14 and 62 days, respectively, during which the LVEF increased by 75% (from 12% to 21%) in Patient 1 and remained unchanged (from 16% to 18%) in Patient 2, whereas the E(max) increased from 0.63 and 0.42 mm Hg/ml, respectively, to 1.31 and 1.07 mm Hg/ml, reflecting a 107% and 155% improvement. In these 2 cases, the E(max) was a more reliable indicator of intrinsic myocardial contractility than was the LVEF.