Peroxidase cytochemistry and ultrastructure of resident macrophages in fetal rat liver: A developmental study

The peroxidase cytochemistry and the ultrastructural characteristics of resident macrophages in fetal rat liver have been investigated. Livers of 10-, 11-, 14-, 17-, and 20-day-old fetuses were fixed by immersion or perfusion, incubated for peroxidase, and processed for transmission electron microscopy. Some 17- and 20-day-old fetuses were injected prior to sacrifice with carbon or 0.8-μm latex particles through the umbilical vein. Some livers were additionally processed for scanning electron microscopy (SEM). The endogenous peroxidase was present in the nuclear envelope (NE) and endoplasmic reticulum (ER) of fetal macrophages with a negative reaction in the Golgi apparatus, a distribution pattern identical to that in Kupffer cells of adult rat liver. Such peroxidase-positive cells avidly took up the injected latex and carbon particles and were the only cell type in fetal liver involved in erythrophagocytosis. Furthermore, they were associated with erythropoietic elements, forming close contacts with such cells, especially normoblasts. The peroxidase pattern in leukopoietic cells differed at all stages of maturation from that in macrophages. By SEM the macrophages exhibited ruffles and lamellopodia on their surfaces and protruded often into the lumen of fetal sinusoids. Macrophages in fetal liver underwent mitotic divisions. The macrophages were first seen on gestation day 11, whereas the first mature monocytes were found on gestation day 17. These observations suggest that resident macrophages in fetal rat liver form a self-replicating cell line independent of the monocytopoietic series, although they may both arise from a common precursor cell.     

Potential effects and relevant lead compounds of Vigna mungo (L.) Hepper seeds against bacterial infection,helminthiasis, thrombosis and neuropharmacological disorders

Multidrug-resistant bacterial infections, helminthiasis, thrombosis, anxiety and insomnia are some of the major global health concerns. Vigna mungo (L.) Hepper (VM) has been used traditionally to treat microbial infection, helminthic disorder, schizophrenia, memory loss, and blood circulatory problem. This research aims to discover antibacterial, anthelmintic, thrombolytic and neuropharmacological effects of the methanol extract of Vigna mungo seeds (MESVM), and also in-silico prediction of relevant lead compounds by molecular docking and ADME/T analysis. The crude extracts and subsequent fractions of MESVM were investigated for antibacterial activity by disc diffusion method, anthelmintic activity by paralysis and death test on earthworms, and thrombolytic activity by in vitro blood clot dissolution test. Open-field test and elevated plus maze test were performed for evaluating anxiolytic activity of the extracts. Using molecular docking, ligand poses of selected VM seeds’ phytoconstituents were predicted targeting tubulin, GlcN-6-P synthase, and human tissue plasminogen activator proteins for anthelmintic, antibacterial, and thrombolytic activity, respectively. In the antibacterial activity test, the MESVM at 10000 μg/mL concentration created highest and significant (P < 0.001) zone of inhibition against Staphylococcus aureus (15.42 mm) and Escherichia coli (12 mm) compared with tetracycline. The MESVM exhibited remarkable anthelmintic activity at 50 mg/mL concentration with 35.4 min paralysis time, 75.2 min death time and were closer to the durations of standard drug albendazole. No test extract showed anxiolytic activity. In thrombolytic activity test, all concentrations of MESVM produced clot lytic activity with high significance (P < 0.001) in comparison with the blank. In docking, 2′-hydroxygenistein, cyclokievitone hydrate, and aureol displayed maximum affinity to the target proteins for anthelmintic, antibacterial, and thrombolytic activity, respectively. This research revealed that the MESVM demonstrated potential anthelmintic, antibacterial and thrombolytic effects that confirmed the folkloric uses of VM and the found relevant lead compounds might be further optimized in future drug development.     

The peroxisome: an update on mysteries

Peroxisomes contribute to several crucial metabolic processes such as β-oxidation of fatty acids, biosynthesis of ether phospholipids and metabolism of reactive oxygen species, which render them indispensable to human health and development. Peroxisomes are highly dynamic organelles that rapidly assemble, multiply and degrade in response to metabolic needs. In recent years, the interest in peroxisomes and their physiological functions has significantly increased. This review intends to highlight recent discoveries and trends in peroxisome research, and represents an update as well as a continuation of a former review article. Novel exciting findings on the biological functions, biogenesis, formation and degradation of peroxisomes, on peroxisomal dynamics and division, as well as on the interaction and cross-talk of peroxisomes with other subcellular compartments are addressed. Furthermore, recent findings on the role of peroxisomes in the brain are discussed.     

Normalization of miRNA qPCR high-throughput data: a comparison of methods

Low-density quantitative real-time PCR (qPCR) arrays are often used to profile expression patterns of microRNAs in various biological milieus. To achieve accurate analysis of expression of miRNAs, non-biological sources of variation in data should be removed through precise normalization of data. We have systematically compared the performance of 19 normalization methods on different subsets of a real miRNA qPCR dataset that covers 40 human tissues. After robustly modeling the mean squared error (MSE) in normalized data, we demonstrate lower variability between replicates is achieved using various methods not applied to high-throughput miRNA qPCR data yet. Normalization methods that use splines or wavelets smoothing to estimate and remove Cq dependent non-linearity between pairs of samples best reduced the MSE of differences in Cq values of replicate samples. These methods also retained between-group variability in different subsets of the dataset.     

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.     

Effect of annealing temperature and dopant concentration on the thermoluminescence sensitivity in LiF:Mg,Cu,Ag material

LiF:Mg,Cu,Ag is a new dosimetry material that is similar to LiF:Mg,Cu,P in terms of dosimetric properties. The effect of the annealing temperature in the range of 200 to 350°C on the thermoluminescence (TL) sensitivity and the glow curve structure of this material at different concentrations of silver (Ag) was investigated. It has been demonstrated that the optimum values of the annealing temperature and the Ag concentration are 240°C and 0.1 mol% for better sensitivity, respectively. The TL intensity decreases at annealing temperatures lower than 240°C or higher than 240°C, reaching a minimum at 300°C and then again increases for various Ag concentrations. It was observed that the glow curve structure altered and the area under the low temperature peak as well as the area under the main dosimetric peak decreased with increasing annealing temperature. The position of the main dosimetric peak moved in the direction of higher temperatures, but at 320 and 350°C annealing temperatures, it shifted to lower temperatures. It was also observed that the TL sensitivity could partially be recovered by a combined annealing procedure.     

The prosegments of furin and PC7 as potent inhibitors of proprotein convertases. In vitro and ex vivo assessment of their efficacy and selectivity

All proprotein convertases (PCs) of the subtilisin/kexin family contain an N-terminal prosegment that is presumed to act both as an intramolecular chaperone and an inhibitor of its parent enzyme. In this work, we examined inhibition by purified, recombinant bacterial prosegments of furin and PC7 on the in vitro processing of either the fluorogenic peptide pERTKR-MCA or the human immunodeficiency virus envelope glycoprotein gp160. These propeptides are potent inhibitors that display measurable selectivity toward specific proprotein convertases. Small, synthetic decapeptides derived from the C termini of the prosegments are also potent inhibitors, albeit less so than the full-length proteins, and the C-terminal P1 arginine is essential for inhibition. The bacterial, recombinant prosegments were also used to generate specific antisera, allowing us to study the intracellular metabolic fate of the prosegments of furin and PC7 expressed via vaccinia virus constructs. These vaccinia virus recombinants, along with transient transfectants of the preprosegments of furin and PC7, efficiently inhibited the ex vivo processing of the neurotrophins nerve growth factor and brain-derived neurotrophic factor. Thus, we have demonstrated for the first time that PC prosegments, expressed ex vivo as independent domains, can act in trans to inhibit precursor maturation by intracellular PCs.     

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.     

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.