Expanding controlled donation after the circulatory determination of death: statement from an international collaborative

A decision to withdraw life-sustaining treatment (WLST) is derived by a conclusion that further treatment will not enable a patient to survive or will not produce a functional outcome with acceptable quality of life that the patient and the treating team regard as beneficial. Although many hospitalized patients die under such circumstances, controlled donation after the circulatory determination of death (cDCDD) programs have been developed only in a reduced number of countries. This International Collaborative Statement aims at expanding cDCDD in the world to help countries progress towards self-sufficiency in transplantation and offer more patients the opportunity of organ donation. The Statement addresses three fundamental aspects of the cDCDD pathway. First, it describes the process of determining a prognosis that justifies the WLST, a decision that should be prior to and independent of any consideration of organ donation and in which transplant professionals must not participate. Second, the Statement establishes the permanent cessation of circulation to the brain as the standard to determine death by circulatory criteria. Death may be declared after an elapsed observation period of 5 min without circulation to the brain, which confirms that the absence of circulation to the brain is permanent. Finally, the Statement highlights the value of perfusion repair for increasing the success of cDCDD organ transplantation. cDCDD protocols may utilize either in situ or ex situ perfusion consistent with the practice of each country. Methods to accomplish the in situ normothermic reperfusion of organs must preclude the restoration of brain perfusion to not invalidate the determination of death.

Urinary nephrospheres indicate recovery from acute kidney injury in renal allograft recipients - a pilot study

Background

Acute kidney injury represents a major threat to the transplanted kidney. Nevertheless, these kidneys have the potential to fully recover. Tubular regeneration following acute kidney injury is driven by the regenerative potential of tubular cells originating from a tubular stem cell pool. We investigated urinary sediments of acute kidney injury transplanted patients and compared it to those of non-transplanted patients. Thereby we discovered tubular cell agglomerates, which have not been described in vivo. We hypothesized that these so-called nephrospheres were associated with recovery from acute kidney injury.

Methods

Urine sediment of 45 kidney-transplanted and 19 non-transplanted individuals was investigated. Nephrospheres were isolated and stained for several molecular markers including aquaporin 1 (AQP1) and calcium sensing receptor (CASR). Nephrospheres were cultured to examine their growth behavior in vitro. In addition, quantitative PCR for CASR, AQP1, and podocin (NPHS2) was performed.

Results

Nephrospheres were excreted in the urine of 17 kidney-transplant recipients 7 days after onset of acute kidney injury and were detectable over several days until kidney function was recovered to baseline creatinine levels. None were found in the urine of non-transplanted individuals. Nephrospheres were either AQP1+/CASR+ or AQP1−/CASR+ and could be cultured for 27 days. Mitotic cells could still be visualized after 17 days in culture. Quantitative PCR detected AQP1 in both kidney-transplanted and non-transplanted individuals during the phase of creatinine decline. As a limitation qPCR was only performed for the entire urinary sediment.

Conclusions

Nephrospheres are three dimensional tubular cell agglomerates which appeared in urine of kidney transplant recipients recovering from acute kidney injury. Appearance of nephrospheres in urine was independent of the duration after kidney transplantation. Nephrospheres proliferated in cell culture and kept expressing kidney specific marker. Presence of nephrospheres in urine showed a specificity of 100% and a sensitivity of 60.71% for recovery.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1454-3) contains supplementary material, which is available to authorized users.

Heterogeneity of Stem Cells in the Thyroid

Identification of thyroid stem cells in the past few years has made important contributions to our understanding of the cellular and molecular mechanisms that induce tissue regeneration and repair. Embryonic stem (ES) cells and induced-pluripotent stem cells have been used to establish reliable protocols to obtain mature thyrocytes and functional follicles for the treatment of thyroid diseases in mice. In addition, the discovery of resident thyroid progenitor cells, along with other sources of stem cells, has defined in detail the mechanisms responsible for tissue repair upon moderate or severe organ injury.In this chapter, we highlight in detail the current state of research on thyroid stem cells by focusing on (1) the description of the first experiments performed to obtain thyroid follicles from embryonic stem cells, (2) the identification of resident stem cells in the thyroid gland, and (3) the definition of the current translational in vivo and in vitro models used for thyroid tissue repair and regeneration.

Design and validation of a clinical-scale bioreactor for long-term isolated lung culture

The primary treatment for end-stage lung disease is lung transplantation. However, donor organ shortage remains a major barrier for many patients. In recent years, techniques for maintaining lungs ex vivo for evaluation and short-term (<12 h) resuscitation have come into more widespread use in an attempt to expand the donor pool. In parallel, progress in whole organ engineering has provided the potential perspective of patient derived grafts grown on demand. As both of these strategies advance to more complex interventions for lung repair and regeneration, the need for a long-term organ culture system becomes apparent. Herein we describe a novel clinical scale bioreactor capable of maintaining functional porcine and human lungs for at least 72 h in isolated lung culture (ILC). The fully automated, computer controlled, sterile, closed circuit system enables physiologic pulsatile perfusion and negative pressure ventilation, while gas exchange function, and metabolism can be evaluated. Creation of this stable, biomimetic long-term culture environment will enable advanced interventions in both donor lungs and engineered grafts of human scale.