Three-dimensional gradient index microlens arrays for light-field and holographic imaging and displays.

The geometric, intensity, and chromatic distortions that are a result of the limitations of the material and processes used to fabricate micro-optical lens arrays (MLAs) degrade the performance of light-field systems. To address these limitations, inkjet print additive manufacturing is used to fabricate planar gradient index (GRIN) lenslet arrays, in which volumetric refractive index profiles are used to embed optical functions that would otherwise require multiple homogeneous index MLA surfaces. By tailoring the optical ink feedstock refractive index spectra, independent control over dispersion is achieved, and achromatic performance is made possible.

Gradient-index Alvarez lenses.

Gradient-index Alvarez lenses (GALs), a new, to the best of our knowledge, type of freeform optical component, are surveyed in this work for their unique properties in generating variable optical power. GALs display similar behavior to conventional surface Alvarez lenses (SALs) by means of a freeform refractive index distribution that has only recently been achievable in fabrication. A first-order framework is described for GALs including analytical expressions for their refractive index distribution and power variation.

Stem cells in burn wound healing: A systematic review of the literature.

Introduction: Severe burns are often associated with high morbidity and unsatisfactory functional and esthetic outcomes. Over the last two decades, stem cells have generated great hopes for the treatment of numerous conditions including burns. The aim of this systematic review is to evaluate the role of stem cell therapy as a means to promote burn wound healing.

Stem Cell Mobilization Is Lifesaving in a Large Animal Preclinical Model of Acute Liver Failure.

Introduction: Acute liver failure (ALF) affects 2000 Americans each year with no treatment options other than liver transplantation. We showed previously that mobilization of endogenous stem cells is protective against ALF in rodents. The objective of this study was to assess whether stem cell mobilizing drugs are lifesaving in a large animal preclinical model of ALF, to assess readiness for a clinical trial.

Pharmacological Mobilization of Endogenous Bone Marrow Stem Cells Promotes Liver Regeneration after Extensive Liver Resection in Rats.

Rapid regeneration of the remnant liver is critical for preventing liver failure and promoting recovery after extensive liver resection. Numerous studies have demonstrated the involvement of bone marrow-derived stem cells in liver regeneration and the potential benefits of bone marrow stem cell therapy. To avoid the preparation of stem cells, we proposed in this study to mobilize endogenous bone marrow stem cells pharmacologically with a combination of AMD3100 (A), an antagonist of CXCR4 and low-dose FK506 (F).

Fibrosis in small syngeneic rat liver grafts because of damaged bone marrow stem cells from chronic alcohol consumption.

A patient with liver failure due to chronic and acute alcohol abuse under consideration for an urgent liver transplant shortly after stopping alcohol may have residual abnormalities that threaten transplant success, particularly for a small graft. To address this, we studied a model in which reduced-size (50%) Lewis rat livers are transplanted into green fluorescence protein transgenic Lewis recipients after they are fed alcohol or a control diet for 5 weeks. Here we show that normal small Lewis grafts transplanted to alcohol-fed Lewis hosts developed fibrosis, whereas no fibrosis was observed in control-fed recipients.

Pharmacological mobilization of endogenous stem cells significantly promotes skin regeneration after full-thickness excision: the synergistic activity of AMD3100 and tacrolimus.

Stem cell therapy has shown promise in treating a variety of pathologies including skin wounds, but practical applications remain elusive. Here, we demonstrate that endogenous stem cell mobilization produced by AMD3100 and low-dose tacrolimus is able to reduce by 25% the time of complete healing of full-thickness wounds created by surgical excision. Equally important, healing was accompanied by reduced scar formation and regeneration of hair follicles.

Interleukin-6 is required for cell cycle arrest and activation of DNA repair enzymes after partial hepatectomy in mice.

Background: Interleukin-6 (IL-6) has been shown to be vital for liver regeneration, however the specific mechanisms and factors involved remain incompletely defined. The present study aimed to investigate whether IL-6 exerts its protective effects via arresting the cell cycle allowing base excision and repair of oxidized DNA after hepatectomy.

Results: Following seventy percent partial hepatectomy (PH) in wild type (WT) mice IL-6 serum levels increased reaching peak levels at 3 hours.

Contribution of extrahepatic small cells resembling small hepatocyte-like progenitor cells to liver mass maintenance in transplantation model of retrorsine-pretreated liver.

Purpose: Retrorsine selectively inhibits hepatocyte proliferation and following liver injury evokes small hepatocyte-like progenitor cells. The aim of this study is to find out whether endogenous extrahepatic cells contribute to small hepatocyte-like progenitor cells after retrorsine treatment.

Methods: Wild-type Lewis rat liver exposed to retrorsine was transplanted into GFP transgenic Lewis rat.

Host stem cells repopulate liver allografts: reverse chimerism.

Liver transplant has become life-saving therapy for thousands of patients with end stage liver disease in the United States, but chronic rejection and the toxicities of immunosuppression remain significant obstacles to the further expansion of this modality and "transplant tolerance" remains a central goal in the field. So we and others are looking for alternative post-transplant strategies. We set out to 'engineer' repopulation after transplantation in a strain combination [dark agouti (DA) to Lewis green fluorescent protein+ (LEW GFP+)] which rejects liver grafts strongly, a model that more closely resembles the situation in humans.

Interleukin-6 is an important mediator for mitochondrial DNA repair after alcoholic liver injury in mice.

Unlabelled: We investigated the hypothesis that a prominent effect of chronic ethanol consumption is mitochondrial DNA (mtDNA) injury and compared this injury in IL-6 knockout (KO) and wild-type (WT) mice. Ethanol feeding for 4 weeks resulted in steatosis and oxidative mtDNA damage (8-OHdG) in both IL-6KO and WT mice. However, the WT mice were able to repair the injury by increased production of mtDNA repair enzymes (OGG-1, Neil 1) and check point (p21, p53) proteins and avoid the mtDNA mutations.

Recruitment of host progenitor cells in rat liver transplants.

Despite major histocompatibility complex incompatibility, liver transplants from Lewis rats to dark agouti (DA) rats survive indefinitely without immunosuppression, and the studies we report sought the mechanism(s) responsible for this. At 1 year, most of the liver reacted positively to host anti-DA antibody. When small (50%) grafts were transplanted, recruitment was more rapid because most of the organ assumed the host phenotype at 3 months.

Amelioration of oxidative mitochondrial DNA damage and deletion after renal ischemic injury by the KATP channel opener diazoxide.

Renal ischemia was induced in the rat by constriction of the renal artery for 45 min, and the ability of the ATP-sensitive K(+) (K(ATP)) channel opener diazoxide (DZ) to ameliorate renal ischemia-reperfusion (I/R) injury was evaluated. In this model, blood urea nitrogen and creatinine were elevated 2 days after I/R injury but returned closer to normal levels by 7 days after reperfusion. Histological staining for reactive oxygen species (ROS) was clearly positive and oxidized DNA, detected by the presence of the stable adduct 8-hydroxy-2'-deoxyguanosine, was clearly present in the cytoplasm of tubular cells after 1 h of reperfusion and declined 7 days after reperfusion.

3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors reduce the risk of perioperative stroke and mortality after carotid endarterectomy.

Objective: There is increasing evidence that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) reduce cardiovascular and cerebrovascular events through anti-inflammatory, plaque stabilization, and neuroprotective effects independent of lipid lowering. This study was designed to investigate whether statin use reduces the incidence of perioperative stroke and mortality among patients undergoing carotid endarterectomy (CEA).

Methods: All patients undergoing CEA from 1994 to 2004 at a large academic medical center were retrospectively reviewed.

Oxidative mitochondrial DNA damage and deletion in hepatocytes of rejecting liver allografts in rats: role of TNF-alpha.

An orthotopic liver transplant model in the rat was used to evaluate the role of tumor necrosis factor alpha (TNF-alpha) in liver transplant rejection. There were significantly increased levels of TNF-alpha mRNA and parallel increases in 8-hydroxy-2' deoxyguanosine (8-OHdG) indicative of oxidative DNA damage present 7 to 12 days after transplantation. Cells staining positively for 8-OHdG were localized to the cytoplasm of hepatocytes adjacent to the TNF-alpha expressing inflammatory cells in the portal areas or in patches surrounded by inflammatory cells in the hepatic sinusoids.

Over-expression of AIF-1 in liver allografts and peripheral blood correlates with acute rejection after transplantation in rats.

Early and accurate detection of acute cellular rejection (ACR) is important in the management of liver allograft recipients. We hypothesized that expression of allograft inflammatory factor (AIF)-1 would be associated with liver allograft rejection as previous studies have shown that a relationship exists between kidney and heart transplantation. Indeed using rat orthotopic transplant models we found that the expression of allograft inflammatory factor-1 (AIF-1) can be detected in both allograft and peripheral blood leukocytes with peak levels detected 7 days following liver transplantation.