Animal model for liver cell banking from non-heart beating donors after prolonged ischaemia time

BACKGROUND AND AIM: Although there is a growing interest on the use of non-heart beating donors to enlarge the liver donor pool, livers with prolonged warm ischaemia time are not currently considered for organ transplantation. We hypothesised that these organs may represent a source of hepatocytes for cell transplantation and/or use in bioartificial liver devices. Thus, we investigated if prolonged ischaemia could influence the recovery and viability of functional hepatocytes dissociated from rat livers. METHODS: Hepatocytes were isolated from the liver within 15 min after death (t=15 min) and after 4, 8 and 12h of ischaemia. Cells were either maintained in culture or cryopreserved. In all products, we evaluated cell recovery and viability, hepatocyte markers and cellular functions, including albumin and urea production. RESULTS: The number of cells per gram of tissue was similar at 15 min, 4 and 8h, while it was significantly decreased at 12h. About 0.2 x 10(6) viable cells expressing hepatocyte markers and producing albumin and urea were isolated up to 8h of ischaemia per gram of tissue. CONCLUSIONS: Recovery of viable and functional hepatocytes seems possible after prolonged ischaemia time. These data warrant the evaluation of hepatocyte isolation from human livers of non-heart beating donors.     

Understanding the "lucky few": The conundrum of HIV-exposed, seronegative individuals

It has been known for many years that not all individuals who are repeatedly exposed to HIV-1 show evidence of viral replication, seroconvert, and eventually develop disease. Quite apart from those who seroconvert but progress slowly to AIDS (ie, slow progressors, longterm nonprogressors, elite controllers), these rare, exposed seronegatives either resist infection or harbor extremely low levels of virus that may be detected only using ultrasensitive methods (occult infection). The correlates of protection that confer this unique status to a tiny minority of HIV-exposed individuals remain a subject of intense interest, investigation, and controversy, as no single genetic or immunologic parameter has yet been able to fully explain this phenomenon. However, there is general consensus that studying these individuals may provide invaluable information to aid in the design of vaccines and therapeutic approaches. This review describes the major findings on this important topic, with a focus on immunologic studies.     

Histologic evaluation of radiofrequency ablation in renal cancer.

AIM: To report on the histologic evaluation of renal tumors after intraoperative radiofrequency ablation (RFA) performed immediately before surgical nephrectomy. MATERIALS AND METHODS: Ten patients with renal tumors were studied. All tumors were confirmed to be renal cell carcinoma before radio frequency ablation treatment. All specimens were stained with hematoxylin and eosin and nicotinamide adenine dinucleotide (NADH). RESULTS: Mean tumor size was 29 mm (range 14 to 48 mm). Of the 10 tumors 5 were completely devitalized with a treatment margin ranged from 1 to 20mm. One tumor needed two treatment sessions. No complication related to radiofrequency treatment was recorded. CONCLUSIONS: Our data indicate that RFA can completely destroy renal tumors. However, in our study, complete tumor cell death was obtained only in 50% of cases. More studies are needed to ensure that is technique is an effective and reproducible treatment.