Numerical evaluation of the capping tendency of microcrystalline cellulose tablets during a diametrical compression test.

Capping is one of the major problems that occur during the tabletting process in the pharmaceutical industry. This study provided an effective method for evaluating the capping tendency during diametrical compression test using the finite element method (FEM). In experiments, tablets of microcrystalline cellulose (MCC) were compacted with a single tabletting machine, and the capping tendency was determined by visual inspection of the tablet after a diametrical compression test. By comparing the effects of double-radius and single-radius concave punch shapes on the capping tendency, it was observed that the capping tendency of double-radius tablets occurred at a lower compaction force compared with single-radius tablets. Using FEM, we investigated the variation in plastic strain within tablets during the diametrical compression test and visualised it using the output variable actively yielding (AC YIELD) of ABAQUS. For both single-radius and double-radius tablets, a capping tendency is indicated if the variation in plastic strain was initiated from the centre of tablets, while capping does not occur if the variation began from the periphery of tablets. The compaction force estimated by the FEM analysis at which the capping tendency was observed was in reasonable agreement with the experimental results.

Molecular cloning and characterization of the NADPH oxidase from the kuruma shrimp, Marsupenaeus japonicus: early gene up-regulation after Vibrio penaeicida and poly(I:C) stimulations in vitro.

Free radicals such as nitric oxide (NO) and reactive oxygen species (ROS) are involved in many physiological processes. In humans, there are 5 homologs of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (Noxes) that generate superoxide (O(2)(-)), which can dismute to produce ROS, and play significant roles in innate immunity and cell proliferation. Though Noxes have been identified in vertebrates (humans and fishes) and some insects, there are very few reports investigating Noxes in crustaceans. In the present study, we describe the entire cDNA sequence (4216 bp) of Marsupenaeus japonicus (kuruma shrimp) Nox (MjNox) generated using reverse transcriptase-polymerase chain reaction (RT-PCR) and random amplification of cDNA ends (RACE). The open reading frame of MjNox encodes a protein of 1280 amino acids with an estimated mass of 146 kDa that has 46.8% sequence homology with the Nox gene of the fruit fly, Drosophila melanogaster. Highly conserved amino acid sequences were observed in the NADPH binding domain. Transcriptional analysis revealed that MjNox mRNA is highly expressed in the lymphoid organ, hepatopancreas and hemocytes of the healthy kuruma shrimp. In the hemocytes, MjNox expression reached its peak 4 h after stimulation with either Vibrio penaeicida or poly(I:C) and decreased to its normal level after 12 h.This study is the first to identify and clone a Nox family member (MjNox) from a crustacean species.

Class B scavenger receptor, Croquemort from kuruma shrimp Marsupenaeus japonicus: Molecular cloning and characterization.

The scavenger receptor, Croquemort is a member of the CD36 superfamily comprising transmembrane proteins involved in the recognition of polyanionic ligands. Various researchers have proved that members of the CD36 superfamily are involved in immunity and developmental processes. In the present study, we report a cDNA encoding the kuruma shrimp, Marsupenaeus japonicus Croquemort scavenger receptor (MjSCRBQ) obtained from a cDNA library of lymphoid organ by RACE amplification. The full-length cDNA of 2098 bp consists an open reading frame of 1596 nucleotides that translates into a 532-amino acid putative protein, with a 5' untranslated region of 323 bp and 3' UTR of 153 bp. The MjSCRBQ is constitutively expressed in gills, heart, hemolymph, hepatopancreas, intestine, lymphoid organ, muscle, nerve, and stomach and at high levels in the brain. Expression analysis in lymphoid organs of shrimp infected with white spot syndrome virus (WSSV) revealed high levels of MjSCRBQ 72 and 120 h post-infection. The MjSCRBQ contains putative functional domains including transmembrane domains and a CD36 domain. Multiple alignments of MjSCRBQ amino acid sequences showed significant identity with Drosophila melanogaster SCRBQ (31%), Salmo salar SCRBQ (29%), Homo sapiens SCRBQ (28%) and Rattus norvegicus SCRBQ (30%). In a phylogenetic analysis, MjSCRBQ was identified in the invertebrate scavenger receptor cluster. This is the first report in crustaceans of the identification and characterization of a Croquemort scavenging receptor.