Initial blood washout during organ procurement determines liver injury and function after preservation and reperfusion

Organ procurement is the first step toward effective liver preservation and comprises a thorough washout of blood components from the microvasculature. To study the efficacy of optimal blood washout of the liver, three groups were compared including low-pressure perfusion with UW-CSS (12 mmHg, group A), which is the routine method in clinical practice, high-pressure perfusion with UW-CSS (100 mmHg, group B) and low-pressure perfusion with modified UW solution (12 mmHg, group C). After procurement all livers were preserved in original UW-CSS for 0, 24 or 48 h, followed by reperfusion in oxygenated Williams Medium E for 24 h at 37 degrees C. Histology results of livers procured in group A, showed good hepatocyte viability but also remaining erythrocytes. However, injury parameters were high and ATP concentrations were low. No functional differences were found. Group B, high pressure, and group C, modified UW-CSS, both showed better results. High-pressure washout is preferable since the warm ischemia time during procurement is short. We propose to use high-pressure UW-CSS perfusion for the initial blood washout of the donor liver instead of the usually used low-pressure washout

No recurrent structural abnormalities apart from i(12p) in primary germ cell tumors of the adult testis

Malignant transformation may be caused by gene deregulation resulting from specific chromosomal rearrangements, by amplification, by mutations in proto-oncogenes, by loss of tumor suppressor genes, or a combination of these. We investigated the role of numerical and structural chromosomal abnormalities in 102 cytogenetically abnormal cases of primary testicular germ cell tumors of adolescents and adults (TGCT) [32 seminomas (SE) and 70 nonseminomatous germ cell tumors (NS)]. We confirmed that an isochromosome for 12p, i(12p), is the only consistent structural chromosomal abnormality in TGCT, present in about 70% of our cases. Both the frequency and the number of copies of i(12p) are higher in NS than in SE. This may suggest that i(12p) is involved in tumor progression. Besides i(12p), several clonal structural chromosomal abnormalities were found, bur none appeared to be specific. SE and NS had chromosome numbers in the triploid range, with significantly higher numbers in SE than in NS (average modal chromosome number of 73.4 in SE and 65.0 in NS). Both in SE and NS, some chromosomes were significantly underrepresented (e.g., 11, 13, 18, and Y) and others overrepresented (e.g., 7, 8, 12, 21, and X). In SE, a significantly higher copy number of chromosomes 7, 15, 19, and 22 was found and a significantly lower number of chromosome 17, compared with NS. These chromosomes may play an important role in the differentiation of TGCT. (C) 1995 Wiley-Liss, Inc

Precision-cut bile duct slices as a model to study regeneration of bile ducts of human donor livers after ischemic preservation injury

Introduction Clinical studies have shown a high incidence of biliary epithelial injury after cold ischemic preservation of donor livers. Insufficient epithelial regeneration from the peribiliary glands (PBGs) has been proposed as a critical mechanism in the pathogenesis of biliary strictures after transplantation. Severe biliary epithelial injury requires proliferation and mobilization of biliary progenitor cells nested in PBGs. Studies on the pathogenesis and prevention of biliary strictures are hampered by the lack of suitable laboratory and animal models. Precision-cut tissue slices are a widely used ex vivo technique, in which thin slices of human tissue are cultured and kept viable with intact intercellular and cell-matrix interactions for up to several days. Aims The aim of this study was to generate precision-cut bile duct slices and study their suitability as a model to study the regenerative capacity of PBGs in donor bile ducts. Methods Large bile ducts of cold preserved livers declined for transplantation (n=10) were isolated and sliced, using a Krumdieck slicer. Bile duct slices were cultured in Williams’ medium E up to 144 hr. Histology and immunohistochemistry (HE, Ki-67, and K19) were performed to assess cell morphology. Results Viable K19-positive PBG cells were observed at all time points. Cell proliferation rate, as assessed by Ki-67 staining, increased from 0% at 24 hr to 25% at 96 hr of culture. Proliferation rate was significantly higher in bile ducts of donors <60 years, compared to donors ≥60 years (21% vs. 11%, p = 0.026) Conclusions Precision-cut bile duct slices are a feasible model to study biliary epithelial regeneration of ischemic injured donor liver bile ducts. This model provides a new ex vivo tool to develop pharmacological strategies to prevent post-transplant biliary strictures