Yeast replicative aging is a process resembling replicative aging in mammalian cells. During aging, wild-type haploid yeast cells enlarge, become sterile, and undergo nucleolar enlargement and fragmentation; we sought gene expression changes during the time of these phenotypic changes. Gene expression studied via microarrays and quantitative real-time reverse-transcription polymerase chain reaction (qPCR) has shown reproducible, statistically significant changes in messenger RNA (mRNA) of genes at 12 and 18-20 generations. Our findings support previously described changes towards aerobic metabolism, decreased ribosome gene expression, and a partial environmental stress response. Our findings include a pseudostationary phase, downregulation of methylation-related metabolism, increased nucleotide excision repair-related mRNA, and a strong upregulation of many of the regulatory subunits of protein phosphatase I (Glc7). These findings are correlated with aging changes in higher organisms as well as with the known involvement of protein phosphorylation states during yeast aging.

Composite tissue allotransplantation (CTA) now represents a valid therapeutic option after the loss of a hand, forearm or digits and has become a novel therapeutic entity in reconstructive surgery. However, long term high-dose multi-drug immunosuppressive therapy is required to ensure graft survival, bearing the risk of serious side effects which halters broader application. Further progression in this field may depend on better understanding of basic immunology and ischemia reperfusion injury in composite tissue grafts.To date, orthotopic hind limb transplantation in rats has been the preferred rodent model for reconstructive transplantation (RT), however, it is an extremely demanding procedure that requires extraordinary microsurgical skills for reattachment of vasculature, bones, muscles and nerves.We have introduced the vascular cuff anastomosis technique to this model, providing a rapid and reliable approach to rat hind limb transplantation. This technique simplifies and shortens the surgical procedure and enables surgeons with basic microsurgical experience to successfully perform the operation with high survival and low complication rates. The technique seems to be well suited for immunological as well as ischemia reperfusion injury (IRI) studies. For the operative procedure a sterile set of microsurgical instruments is utilized. The surgeon should wear proper attire including sterile gloves, which have to be changed prior to the start of the surgical procedure. 2. The rat is anesthetized with an intraperitoneal injection of pentobarbital (50mg/kg IP) and placed supine on a heated operation field, which facilitates a stable animal body temperature throughout the entire surgical procedure. 3. Prior to skin incision the filed of operation is sanitized three times each with both, a disinfectant and alcohol. To prevent the animal's corneas from drying out, eyes are lubricated with an ophthalmic ointment (Vidisic) prior to surgery. 4. A skin incision is made across the right groin approximately at the level of the inguinal ligament. The femoral vessels are dissected free with bipolar cautery and blunt dissection; deep branches are ligated with 8-0 silk. 5. 300μl (50 IU) of heparin are injected via the penile vein for anti-coagulation. 6. Femoral vessels are ligated at the level of the inguinal ligament and cut distal to the ligature. 7. The hind limb is flushed with ice-cold (4°C) HTK solution (5ml) via the femoral artery over 5 minutes. 8. All muscle groups are sharply divided with scissors and osteotomy is performed with a rotating electrical saw at the level of the distal third of the femur. 9. The harvested limb is then submerged in 20mL of ice-cold HTK solution for preservation and cold storage until transplantation. Protocol Donor Operation and1. The rat is anesthetized with an intraperitoneal injection of pentobarbital and placed supine on the operation field. 2. A skin incision is made across the right groin approximately at the level of the inguinal ligament. The femoral vessels are dissected ...

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y These authors contributed equally to this study.Vascularized composite allotransplantation (VCA) has emerged as a treatment option for treating nonlife-threatening conditions. Therefore, in order to make VCA a safe reconstruction option, there is a need to minimize immunosuppression, develop tolerance-inducing strategies and elucidate the mechanisms of VCA rejection and tolerance. In this study we explored the effects of hIL-2/Fc (a long-lasting human IL-2 fusion protein), in combination with antilymphocyte serum (ALS) and short-term cyclosporine A (CsA), on graft survival, regulatory T cell (Treg) proliferation and tolerance induction in a rat hind-limb transplant model. We demonstrate that hIL-2/Fc therapy tips the immune balance, increasing Treg proliferation and suppressing effector T cells, and permits VCA tolerance as demonstrated by long-term allograft survival and donor-antigen acceptance. Moreover, we observe two distinct types of acute rejection (AR), progressive and reversible, within hIL-2/Fc plus ALS and CsA treated recipients. Our study shows differential gene expression profiles of FoxP3 versus GzmB, Prf1 or interferon-g in these two types of AR, with reversible rejection demonstrating higher Treg to Teff gene expression. This correlation of gene expression profile at the first clinical sign of AR with VCA outcomes can provide the basis for further inquiry into the mechanistic aspects of VCA rejection and future drug targets.

Although the O'Brien modification allows approximately 50 percent further advancement than the Z-plasty modification compared with the standard Moberg flaps, the increase correlates to a large area of exposed neurovascular bundles at the volar base of the thumb, which requires secondary coverage. However, all Z-plasty donor-sites could be closed primarily. Primary closure of all donor sites will decrease healing time, wound complications, digital nerve sensitivity, and cosmetic appearance. This study is the first to show a significant increase in Moberg flap advancement using Z-plasty lengthening at the thumb base while avoiding any increased morbidity.