Small interfering RNA–mediated gene suppression as a therapeutic intervention in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the lethal and difficult-to-cure cancers worldwide. Owing to the late diagnosis and drug resistance of malignant hepatocytes, treatment of this cancer by conventional chemotherapy agents is challenging, and researchers are seeking new alternative treatment options to overcome therapy resistance in this neoplasm. RNA interference (RNAi) is a potent and specific approach in targeting gene expression and has emerged as a novel therapeutic tool for many diseases, including cancers. Small interfering RNA (siRNA) is a type of RNAi that is produced intracellularly from exogenous synthetic oligonucleotides and can selectively knock down target gene expression in a sequence-specific manner. Various factors play roles in the initiation and progression of HCC and provide multiple candidate targets for siRNA intervention. In addition, due to the liver's unique architecture and availability of some hepatic siRNA delivery methods, this organ has received much more attention as a target tissue for such oligonucleotide action. Recent advances in designing nanoparticle systems for the in vivo delivery of siRNAs have markedly enhanced the potency of siRNA-mediated gene silencing under clinical development for HCC therapy. The utility of siRNAs as anti-HCC agents is the subject of the current review. siRNA-based gene therapies could be one of the main feasible approaches for HCC therapy in the future.     

Mammalian peroxisomes and reactive oxygen species

The central role of peroxisomes in the generation and scavenging of hydrogen peroxide has been well known ever since their discovery almost four decades ago. Recent studies have revealed their involvement in metabolism of oxygen free radicals and nitric oxide that have important functions in intra- and intercellular signaling. The analysis of the role of mammalian peroxisomes in a variety of physiological and pathological processes involving reactive oxygen species (ROS) is the subject of this review. The general characteristics of peroxisomes and their enzymes involved in the metabolism of ROS are briefly reviewed. An expansion of the peroxisomal compartment with proliferation of tubular peroxisomes is observed in cells exposed to UV irradiation and various oxidants and is apparently accompanied by upregulation of PEX genes. Significant reduction of peroxisomes and their enzymes is observed in inflammatory processes including infections, ischemia-reperfusion injury, and allograft rejection and seems to be related to the suppressive effect of tumor necrosis factor- on peroxisome function and peroxisome proliferator activated receptor-. Xenobiotic-induced proliferation of peroxisomes in rodents is accompanied by the formation of hepatic tumors, and evidently the imbalance in generation and decomposition of ROS plays an important role in this process. In PEX5^–/– knockout mice lacking functional peroxisomes severe alterations of mitochondria in various organs are observed which seem to be due to a generalized increase in oxidative stress confirming the important role of peroxisomes in homeostasis of ROS and the implications of its disturbances for cell pathology.     

Upper eyelid ptosis repair after cataract extraction and the importance of Hering's test.

Blepharoptosis is a well-documented complication of cataract extraction and other ocular procedures. Few authors have described the surgical findings and outcomes of postcataract blepharoptosis repair. The authors present a review of the causes of postcataract blepharoptosis with emphasis on both clinical findings and recommendations for treatment on the basis of their experience with 13 eyelids in eight patients over the past 10 years. They found that all patients had either partial or total disinsertion of the levator muscle from the tarsal plate. Of the eight patients in this series, five had bilateral blepharoptosis after bilateral cataract extraction. Although a multifactorial cause for postcataract blepharoptosis is commonly assumed, the authors propose that the mechanical forces of intraoperative traction on the levator aponeurosis during cataract surgery are the primary cause. This is further supported by their operative findings in the five patients who developed bilateral ptosis after bilateral cataract extraction. All eyelids in this series were repaired by levator muscle advancement and attachment to the tarsal plate with favorable outcomes and no recurrences during a 1-year follow-up. The importance of Hering's phenomenon of equal innervation is also discussed as it applies to bilateral and to apparent unilateral blepharoptosis. The authors propose "Hering's test" as an important indicative study in the preoperative evaluation of all patients with eyelid ptosis.     

Multiplex Pyrosequencing

We describe here the development of a new and simple single-tube multiplex Pyrosequencing assay. Genomic DNA or cDNA was employed to PCR amplify region(s) using biotinylated and normal primer(s). Subsequent to capture of PCR products on streptavidin-coated beads, single-stranded DNA separation and hybridization of multiple sequencing primers, Pyrosequencing was performed. The obtained pyrogram resulted in a unique pattern in which the intensity of the signal determined the number of incorporated nucleotide(s). Here, we demonstrate the use of this multiplex Pyrosequencing for single nucleotide polymorphisms genotyping and microbial typing.     

Immunolocalization of four antioxidant enzymes in digestive glands of mollusks and crustaceans and fish liver

The aim of this work was to determine the immunolocalization of the antioxidant enzymes catalase, Cu,Zn-superoxide dismutase (SOD), Mn-SOD, and glutathione peroxidase (GPX) in the bivalve mollusks Mytilus galloprovincialis and Crassostrea sp., the crab Carcinus maenas, and the teleostean fish Mugil cephalus. By immunoblotting, crossreactivity between antibodies and the corresponding proteins in the digestive gland/hepatopancreas of invertebrates and the fish liver was demonstrated. Immunohistochemical studies showed that the stomach epithelium was strongly immunostained for catalase in mollusks. In crabs, ducts showed stronger immunostaining than tubules and in mullet hepatocytes the reaction appeared in discrete granules corresponding to peroxisomes. With regard to Cu,Zn-SOD, the apex of the tubule cells in mussels and crabs was distinctly immunostained, whereas in oysters the reaction was more marked in ducts and in mullet liver a uniform diffuse cytoplasmic staining was found. Mn-SOD was strongly positive in mollusk and crab ducts and in mullet periportal hepatocytes. Finally, GPX was not detected in mussels while in oysters a slight reaction was noted in all cell types. In crabs, connective tissue cells and the apex of duct cells were immunostained, but in mullet liver only erythrocytes appeared reactive. Immunoelectron microscopy revealed that catalase was localized in peroxisomes with a dense labeling in fish and less intense labeling in invertebrates. Cu,Zn-SOD was mainly a cytosolic protein although additional positive subcellular sites (peroxisomes, nuclei) were also observed, while Mn-SOD was restricted to mitochondria. GPX was localized in the cytosol, nucleus, and lysosomes, occurring also in peroxisomes of the fish liver. The results presented here provide a basis for future application of the immunodetection techniques to study the possible differential induction of antioxidant enzymes in aquatic organisms subjected to oxidative stress as a result of exposure to environmental pollutants.     

Osteosynthesis and bony healing between two consecutive free fibular bone grafts

This case report describes a recurrent squamous cell carcinoma in the oral cavity requiring two consecutive free fibula transfers at different times. In a unique application of the fibula, rigid miniplate fixation was used between the two independent free flaps to reconstitute the contour of the mandible for an extensive composite oromandibular defect, extending from the left angle to the right ascending ramus. This application underscores the utility of the free osteocutaneous fibular flap for reconstruction of complex mandibular defects.     

Everything in Moderation - Dietary Diversity and Quality,Central Obesity and Risk of Diabetes

Diet guidelines recommend increasing dietary diversity. Yet, metrics for dietary diversity have neither been well-defined nor evaluated for impact on metabolic health. Also, whether diversity has effects independent of diet quality is unknown. We characterized and evaluated associations of diet diversity and quality with abdominal obesity and type II diabetes (T2D) in the Multi-Ethnic Study of Atherosclerosis. At baseline (2000–02), diet was assessed among 5,160 Whites, Hispanic, Blacks, and Chinese age 45–84 y and free of T2D, using a validated questionnaire. Three different aspects of diet diversity were characterized including count (number of different food items eaten more than once/week, a broad measure of diversity), evenness (Berry index, a measure of the spread of the diversity), and dissimilarity (Jaccard distance, a measure of the diversity of the attributes of the foods consumed). Diet quality was characterized using aHEI, DASH, and a priori pattern. Count and evenness were weakly positively correlated with diet quality (r with AHEI: 0.20, 0.04), while dissimilarity was moderately inversely correlated (r = -0.34). In multivariate models, neither count nor evenness was associated with change in waist circumference (WC) or incident T2D. Greater food dissimilarity was associated with higher gain in WC (p-trend<0.01), with 120% higher gain in participants in the highest quintile of dissimilarity scores. Diet diversity was not associated with incident T2D. Also, none of the diversity metrics were associated with change in WC or incident T2D when restricted to only healthier or less healthy foods. Higher diet quality was associated with lower risk of T2D. Our findings provide little evidence for benefits of diet diversity for either abdominal obesity or diabetes. Greater dissimilarity among foods was actually associated with gain in WC. These results do not support the notion that “eating everything in moderation” leads to greater diet quality or better metabolic health.     

Consequences of fission in the coral <Emphasis Type="Italic">Siderastrea siderea</Emphasis>: growth rates of small colonies and clonal input to population structure

Colony age and size can be poorly related in scleractinian corals if colonies undergo fission to form smaller independent patches of living tissue (i.e., ramets), but the implications of this life-history characteristic are unclear. This study explored the ecological consequences of the potential discrepancy between size and age for a massive scleractinian, first by testing the effect of colony origin on the growth of small colonies, and second by quantifying the contribution of ramets to population structure. Using Siderastrea siderea in St. John (US Virgin Islands) as an experimental system, the analyses demonstrated that the growth of small colonies derived from sexual reproduction was 2.5-fold greater than that of small ramets which were estimated to be ≈100 years older based on the age of the parent colonies from which they split. Although fission can generate discrete colonies, which in the case of the study reef accounted for 42% of all colonies, it may depress colony success and reef accretion through lowered colony growth rates.