Jacob Lavee

Patient Characteristics and Cell Source Determine the Number of Isolated Human Cardiac Progenitor Cells

Background— The identification and isolation of human cardiac progenitor cells (hCPCs) offer new approaches for myocardial regeneration and repair. Still, the optimal source of human cardiac progenitor cells and the influence of patient characteristics on their number remain unclear. Using a novel method to isolate human cardiac progenitor cells, we aimed to define the optimal source and association between their number and patient characteristics. Methods and Results— We developed a novel isolation method that produced viable cells (7×106±6.53×105/g) from various tissue samples obtained during heart surgery or endomyocardial biopsies (113 samples from 94 patients 23 to 80 years of age). The isolated cardiac cells were grown in culture with a stem cell expansion medium. According to fluorescence-activated cell sorting analysis, cultured cells derived from the right atrium generated higher amounts of c-kit+ (24±2.5%) and Islet-1+ cells (7%) in culture (mean of passages 1, 2, and 3) than did cultured cells from the left atrium (7.3±3.5%), right ventricle (4.1±1.6%), and left ventricle (9.7±3%; P=0.001). According to multivariable analysis, the right atrium as the cell source and female sex were associated with a higher number of c-kit+ cells. There was no overlap between c-kit+ and Islet-1 expression. In vitro assays of differentiation into osteoblasts, adipocytes, and myogenic lineage showed that the isolated human cardiac progenitor cells were multipotent. Finally, the cells were transplanted into infarcted myocardium of rats and generated myocardial grafts. Conclusion— Our results show that the right atrium is the best source for c-kit+ and Islet-1 progenitors, with higher percentages of c-kit+ cells being produced by women.

A Novel Nonthermal Energy Source for Surgical Epicardial Atrial Ablation: Irreversible Electroporation

BACKGROUND All currently used energy sources in surgical ablation for atrial fibrillation create lesions via thermal injury. We report for the first time the in vivo results of a new nonthermal modality of epicardial atrial ablation called irreversible electroporation (IRE). IRE utilizes a sequence of electrical pulses that produce permanent nonthermal damage to tissue in a few seconds with sharp borders between affected and unaffected regions. METHODS Five pigs underwent beating heart surgical epicardial ablations of their right and/or left atrial appendages, utilizing a sequence of 8, 16, or 32 direct current pulses of 1500 to 2000 V, 100 micros each, at a frequency of 5 per second, applied between two 4-cm long parallel electrodes with an IRE pulse generator. Local temperature measurements were performed during ablations followed by electrical isolation testing by pacing. Animal hearts were excised 24 hours after surgery and processed histologically to evaluate the degree of myocardial tissue necrosis and transmurality. RESULTS A clear demarcation line between ablated and normal tissue, with no tissue disruption or charring, was observed on gross inspection of all lesions. Staining results showed complete transmural destruction of atrial tissue at the site of the electrode application in all 10 atrial lesions, measuring a mean of 0.9 cm in depth. Each 3- to 3.5-cm long lesion was created in 1 to 4 seconds with no local temperature change and with demonstration of electrical isolation. CONCLUSIONS We propose a new modality to perform atrial ablations, which holds the potential of providing very swift, precise, and complete transmurality with no local heating effects.

A new law for allocation of donor organs in Israel

Israel’s system for organ donation has been based, since its inception in 1968, on a model in which organs for transplantation are retrieved from brain-dead donors only after consent has been obtained from the appropriate fi rst-degree relatives. This consent is needed even if the potential donor has expressed a wish for posthumous organ donation by signing a donor card, which is a government form that allows people to voluntarily indicate their wish to donate specifi ed organs after their death. The consent rate for organ donation in Israel, defi ned as the proportion of actual donors of total number of medically eligible brain-dead donors, has consistently been 45% during the past decade, much lower than in most western countries. Similarly, the proportion of adults with donor cards in Israel is only 10%. In January, 2008, 864 candidates were listed for kidney, heart, lung, or liver transplantation, but only 221 patients were given transplants from deceased donors that year. In two formal surveys of public attitudes towards organ donation, which were done by the Israel National Transplant Centre in 1999 (n=758) and 2004 (n=417), 55% of individuals in each survey indicated their willingness to donate organs in exchange for prioritisation in organ allocation. In both surveys, the proportion of individuals who chose this option was much greater than the proportions choosing the second and third preferred options, which were direct (26%) or indirect fi nancial compensation (25%), respectively, for organ donation. The basis of this public reaction is mainly a perceived need to rectify the unfairness of free riders—people who are willing to accept an organ but refuse to donate one— as practised by a small yet prominent proportion of the Israeli public. These individuals are opposed to the idea of brain death and organ donation, yet they do not abstain from becoming candidates for transplantation when they need an organ for themselves. The results of the surveys of attitudes of Israeli people resemble those noted in similar surveys done in the USA in 1990 and 2004, in which 52% and 53% of responders, respectively, ranked a preferred status in organ allocation as their top-ranked option for compensation for organ donation. With the grim national statistics for organ donation, and the knowledge that relatives of potential donors who were holders of donor cards have consistently given their consent for organ donation, a national plan for prioritisation of organ allocation was devised to increase the number of individuals with donor cards in the hope that such an increase would lead to an increase in organ donation. The plan to increase the national number of individuals who have a donor card by giving priority in organ allocation to transplant candidates who had signed a donor card before their listing date was fi rst suggested to the Israel National Transplant Council (INTC) in March, 2006. This council established a special interdisciplinary committee—inclu ding leading ethicists, philosophers, legal advisers, representatives of the main religions, transplant physicians, surgeons, and coordinators—to review the various relevant ethical, legal, medical, and social issues. After long discussions, the committee recommended to the INTC that any candidate for a transplant who had a donor card for at least 3 years before being listed as a candidate will be given priority in organ allocation. Similar priority will be granted to transplant candidates with a fi rst-degree relative who was a deceased organ donor and to any live donor of a kidney, liver lobe, or lung lobe who subsequently needs an organ. Because the new plan includes, for the fi rst time, implementation of non-medical criteria in organ allocation, legal advisers said the policy could not be implemented by administrative rules and required legislation by the Israeli Parliament. After the approval of these recommendations by the INTC, the Ministry of Health has asked Israel’s Parliament to incorporate the prioritisation plan into the new bill for organ transplantation. After a long debate within the Israeli Parliament, clause 9(B)4 was added to the recently approved law for organ transplantation (panel). The Israeli law has increased the number of benefi ciaries for organ allocation from the signatory on the donor card to the fi rst-degree relatives (parents, children, sibling, or spouse) on the basis of past experience, whereby relatives who were holders of the card had always given their consent to organ donation even if the donor did not sign it, yet reduced the number of benefi ciaries by excluding living-directed donors. This restriction, which contradicts the INTC’s original recommendation, is being prepared by the Ministry of Health for an appeal for reconsideration by Parliament, because we strongly believe all living donors should be granted prioritisation in organ allocation. On the basis of a new law, the steering committee for Israel’s National Transplant Centre decided to set up three allocation priority categories with diff erent levels for each transplanted organ (table). On the one hand, a transplant candidate with a fi rst-degree relative who has signed a donor card would be given half the allocation priority that is given to a transplant candidate who has signed his or her own donor card. On the other hand, a transplant candidate with a fi rst-degree relative who donated organs after death or who was an eligible live non-directed organ donor would be given allocation priority 1·5 times greater than that given to candidates who have signed their own donor cards. Among candidates with an equal number of allocation points, organs will be allocated fi rst to prioritisation-eligible candidates. Lancet 2010; 375: 1131–33

Preliminary Marked Increase in the National Organ Donation Rate in Israel Following Implementation of a New Organ Transplantation Law

Israels organ donation rate has always been among the lowest in Western countries. In 2008 two new laws relevant to organ transplantation were introduced. The Brain‐Respiratory Death Law defines the precise circumstances and mechanisms to determine brain death. The Organ Transplantation Law bans reimbursing transplant tourism involving organ trade, grants prioritization in organ allocation to candidates who are registered donors and removes disincentives for living donation by providing modest insurance reimbursement and social supportive services. The preliminary impact of the gradual introduction and implementation of these laws has been witnessed in 2011. Compared to previous years, in 2011 there was a significant increase in the number of deceased organ donors directly related to an increase in organ donation rate (from 7.8 to 11.4 donors per million population), in parallel to a significant increase in the number of new registered donors. In addition the number of kidney transplantations from living donors significantly increased in parallel to a significant decrease in the number of kidney transplantations performed abroad (from 155 in 2006 to 35 in 2011). The new laws have significantly increased both deceased and living organ donation while sharply decreasing transplant tourism.

Platelet protection by low-dose aprotinin in cardiopulmonary bypass: Electron microscopic study

To evaluate the effect of low-dose aprotinin during cardiopulmonary bypass on platelet function and clinical hemostasis, 30 patients undergoing various cardiopulmonary bypass procedures employing bubble oxygenators were randomized to receive either low-dose aprotinin (2 x 10(6) KIU in the cardiopulmonary bypass priming solution, 15 patients [group A]) or placebo (15 patients [group B]). Blood samples were collected before and after cardiopulmonary bypass to assess platelet count and aggregation on extracellular matrix, which was studied by a scanning electron microscope. On a scale of 1 to 4 preoperative mean platelet aggregation grades were similar in both groups (3.8 +/- 0.5 and 3.5 +/- 0.5 for groups A and B, respectively). Postoperatively, platelet aggregation on extracellular matrix decreased slightly in group A (2.8 +/- 1.3; p < 0.01) and significantly in group B (1.3 +/- 0.5; p < 0.001). Eleven of the 15 patients in group A remained in aggregation grade 3 or 4 compared with none of the group B patients. Platelet count was similar in both groups preoperatively and postoperatively. Total 24-hour postoperative bleeding and blood requirement were lower in the aprotinin group (487 +/- 121 mL and 2.3 +/- 1.0 units) than in the placebo group (752 +/- 404 mL and 6.8 +/- 5.1 units; p < 0.01). These results show that the use of low-dose aprotinin during cardiopulmonary bypass provides improved postoperative hemostasis, which might be related to the protection of the platelet aggregating capacity.

Organ trafficking and transplant tourism: the role of global professional ethical standards-the 2008 Declaration of Istanbul.

By 2005, human organ trafficking, commercialization, and transplant tourism had become a prominent and pervasive influence on transplantation therapy. The most common source of organs was impoverished people in India, Pakistan, Egypt, and the Philippines, deceased organ donors in Colombia, and executed prisoners in China. In response, in May 2008, The Transplantation Society and the International Society of Nephrology developed the Declaration of Istanbul on Organ Trafficking and Transplant Tourism consisting of a preamble, a set of principles, and a series of proposals. Promulgation of the Declaration of Istanbul and the formation of the Declaration of Istanbul Custodian Group to promote and uphold its principles have demonstrated that concerted, strategic, collaborative, and persistent actions by professionals can deliver tangible changes. Over the past 5 years, the Declaration of Istanbul Custodian Group organized and encouraged cooperation among professional bodies and relevant international, regional, and national governmental organizations, which has produced significant progress in combating organ trafficking and transplant tourism around the world. At a fifth anniversary meeting in Qatar in April 2013, the DICG took note of this progress and set forth in a Communiqué a number of specific activities and resolved to further engage groups from many sectors in working toward the Declaration’s objectives.

MRI study on reversible and irreversible electroporation induced blood brain barrier disruption

Electroporation, is known to induce cell membrane permeabilization in the reversible (RE) mode and cell death in the irreversible (IRE) mode. Using an experimental system designed to produce a continuum of IRE followed by RE around a single electrode we used MRI to study the effects of electroporation on the brain. Fifty-four rats were injected with Gd-DOTA and treated with a G25 electrode implanted 5.5 mm deep into the striata. MRI was acquired immediately after treatment, 10 min, 20 min, 30 min, and up to three weeks following the treatment using: T1W, T2W, Gradient echo (GE), serial SPGR (DCE-MRI) with flip angles ranging over 5–25°, and diffusion-weighted MRI (DWMRI). Blood brain barrier (BBB) disruption was depicted as clear enhancement on T1W images. The average signal intensity in the regions of T1-enhancement, representing BBB disruption, increased from 1887±83 (arbitrary units) immediately post treatment to 2246±94 20 min post treatment, then reached a plateau towards the 30 min scan where it reached 2289±87. DWMRI at 30 min showed no significant effects. Early treatment effects and late irreversible damage were clearly depicted on T2W. The enhancing volume on T2W has increased by an average of 2.27±0.27 in the first 24–48 hours post treatment, suggesting an inflammatory tissue response. The permanent tissue damage, depicted as an enhancing region on T2W, 3 weeks post treatment, decreased to an average of 50±10% of the T2W enhancing volumes on the day of the treatment which was 33±5% of the BBB disruption volume. Permanent tissue damage was significantly smaller than the volume of BBB disruption, suggesting, that BBB disruption is associated with RE while tissue damage with IRE. These results demonstrate the feasibility of applying reversible and irreversible electroporation for transient BBB disruption or permanent damage, respectively, and applying MRI for planning/monitoring disruption volume/shape by optimizing electrode positions and treatment parameters.

Preliminary experience with FK506 in thoracic transplantation

FK506, a potent immunosuppressive macrolide antibiotic, underwent initial clinical trails in liver recipients with intractable rejection or refractory drug toxicity (1, 2). The dramatic results achieved by this agent in “rescue” therapy were followed shortly by its introduction as a primary immunosuppressant in kidney and liver recipients beginning in March 1989 at the Presbyterian University and Childrens Hospital of Pittsburgh (3, 4). In October 1989, a prospective clinical trial was begun using FK506 and low-dose steroids as the sole immunosuppression in patients undergoing orthotopic cardiac transplantation. The preliminary results using FK506 and low-dose steroids as primary immunosuppression in 23 patients following cardiac transplantation and in 4 patients as “rescue” therapy for refractory rejection or drug toxicity are reported here.

Impact of legal measures prevent transplant tourism: the interrelated experience of The Philippines and Israel

We describe the parallel changes that have taken place in recent years in two countries, Israel and The Philippines, the former once an “exporter” of transplant tourists and the latter once an “importer” of transplant tourists. These changes were in response to progressive legislation in both countries under the influence of the Declaration of Istanbul. The annual number of Israeli patients who underwent kidney transplantation abroad decreased from a peak of 155 in 2006 to an all-time low of 35 in 2011 while in the Philippines the annual number of foreign transplant recipients fell from 531 in 2007 to two in 2011. The experience of these two countries provides a “natural experiment” on the potential impact of legal measures to prevent transplant tourism.

The use of executed prisoners as a source of organ transplants in China must stop.

Internationally accepted ethical standards are unequivocal in their prohibition of the use of organs recovered from executed prisoners: yet this practice continues in China despite indications that Ministry of Health officials intend to end this abhorrent practice. Recently published articles on this topic emphasize the medical complications that result from liver transplantation from executed ‘donors’ but scant attention is given to the source of the organs, raising concern that the transplant community may be coming inured to unacceptable practice. Strategies to influence positive change in organ donation practice in China by the international transplant community are discussed. They include an absolutist policy whereby no clinical data from China is deemed acceptable until unacceptable donation practices end, and an incremental policy whereby clinical data is carefully evaluated for acceptability. The relative advantages and drawbacks of these strategies are discussed together with some practical suggestions for response available to individuals and the transplant community.