Genomic structure around joining segments and constant regions of swine T-cell receptor alpha/delta (TRA/TRD) locus

A complete genomic region of 131.2 kb including the swine T-cell receptor alpha/delta constant region (TRAC/TRDC) and joining segments (TRAJ/TRDJ) was sequenced. The structure of this region was strikingly conserved in comparison to that of human or mouse. All of the 61 TRAJ segments detected in the human genomic sequence were detected in the swine sequence and the sequence of the protein binding site of T early alpha, the sequence of the alpha enhancer element and the conserved sequence block between TRAJ3 and TRAJ4 are highly conserved. Insertion of the repetitive sequences that interspersed after the differentiation of the species in mammals such as short interspersed nucleotide elements is markedly suppressed in comparison to other genomic regions, while the composition of the mammalian-wide interspersed sequences is relatively conserved in human and swine. This observation indicates the existence of a highly selective pressure to conserve this genomic region around TRAJ throughout the evolution of mammals.     

Notch-RBP-J signaling is involved in cell fate determination of marginal zone B cells

RBP-J is a key mediator of Notch signaling that regulates cell fate determination in various lineages. To investigate the function of Notch-RBP-J in mature B cell differentiation, we generated mice that selectively lacked B cell RBP-J expression using conditional mutagenesis. Absence of RBP-J led to the loss of marginal zone B (MZB) cells with a concomitant increase in follicular B cells; in contrast, B1 cells in the peritoneal cavity were unaffected. Lack of RBP-J caused no defects in B cells maintenance, survival, plasma cell differentiation or activation. It is therefore likely that Notch-RBP-J signaling regulates the lineage commitment of mature B cells into follicular versus MZB cells. In addition, in mice with RBP-J-deficient B cells, had no obvious changes in immunoglobulin production in response to Ficoll, lipopolysaccharide or chicken gammaglobulin. In contrast, these mice exhibited increased mortality rates after blood-borne bacterial infection, which indicates that MZB cells play pivotal roles in the clearance of these bacteria.     

Activity of anthocyanins from fruit extract of Ribes nigrum L. against influenza A and B viruses

Earlier, we have detected antiviral activity in an extract from Ribes nigrum L. fruits ("Kurokarin", name of the one species of black currant in Japanese) against influenza A and B viruses, and herpes simplex virus 1 (Knox et al., Food Processing 33, 21-23, 1998). In the present study, the antiviral activity of constituents of a Kurokarin extract and the mechanism of its antiviral action were examined. Kurokarin extracts were separated to fractions A to D by column chromatography. The major constituents of the fraction D were estimated as anthocyanins. The fraction D was further fractionated by thin-layer chromatography (TLC) to fractions A' to G'. The fraction E' consisted of 3-O-alpha-L-rhamnopyranosyl-beta-D-glucopyranosyl-cyanidin and 3-O-beta-D-glucopyranosyl-cyanidin, and the fraction F' consisted of 3-O-alpha-L-rhamnopyranosyl-beta-D-glucopyranosyl-delphinidin and 3-O-beta-D-glucopyranosyl-delphinidin, identified by high performance liquid chromatography (HPLC) with standards and by high resolution mass spectrometry. The fractions D' to G' showed potent antiviral activity against influenza viruses A and B. The additive antiviral effect of a combination of the fractions E' and F' was assessed. Anthocyanins in the fraction F' did not directly inactivate influenza viruses A and B, but they inhibited virus adsorption to cells and also virus release from infected cells.     

Expression of S-100 protein in intercalated duct cells of bovine pancreas

Although Mutoh et al. have found intercalated ducts in the pancreatic islets of avians, including the chicken, moorhen (Gallinula chloorpus), and Japanese quail (Coturnix coturnix japonica), and even demonstrated the functions of intercalated duct cells in pancreatic islets, to our knowledge, there have been only a few reports on the relationship between intercalated ducts and islets in mammalia. Accordingly, in this study, we investigated whether intercalated ducts are morphologically related to the islets of cattle, by using S-100 protein as a ductal cell marker for immunocytochemistry and examining the ultrastructure of intercalated ducts and islets electron-microscopically. The results revealed intercalated ducts that reacted positively for S-100 protein within and near islets, with approximately 12% of the islets having intercalated ducts in the vicinity and approximately 1.5% containing intercalated ducts within them. Ultrastructurally, intercalated ducts were also seem to be closely related to the islets. In conclusion, the results of the present study indicate that a close relationship exists between intercalated ducts and islets.     

Heterotopic transplantation of the failing rat heart as a model of left ventricular mechanical unloading toward recovery

The left ventricular assist device (LVAD) is usually used in patients with end-stage heart failure as a bridge to transplantation. Recently, some studies have reported functional recovery with the use of an LVAD, although the mechanisms responsible for recovery are not fully understood. We investigated the functional recovery of the infarcted, failing rat heart in response to mechanical unloading after heterotopic transplantation. Heart failure was induced in Lewis rats by ligating the left anterior descending artery. After 4 weeks, the infarcted hearts were harvested and heterotopically transplanted. The transplanted infarcted heart was removed after 2 weeks of unloading and examined for hypertrophy and fibrosis, as well as for mRNA levels encoding for brain natriuretic peptide, sarco(endo)plasmic reticulum Ca(2+)-ATPase2a (SERCA2a), and beta1- and beta2-adrenergic receptors. Normal and infarcted rats without transplantation served as control animals. The infarcted heart was hypertrophied as evidenced by an increase in heart weight and myocyte diameter. After unloading the infarcted heart for 2 weeks, there was a decrease in heart weight and myocyte diameter. However, the percentage of myocardial fibrosis increased after unloading. The mRNA expression of brain natriuretic peptide and the beta2-adrenergic receptor significantly improved after mechanical unloading. The levels of SERCA2a mRNA tended to increase after unloading. In conclusion, unloading the failing, infarcted heart can help normalize left ventricular hypertrophy and cardiac gene expression. This unloading model appears to partially mimic the conditions of hemodynamic support with an LVAD in heart failure patients and potentially offers insights into the mechanisms of functional recovery.     

Distribution of cocaine recognition sites in rat brain: In vitro and ex vivo autoradiography with [I]RTI-55

The distribution of binding sites of [¹²⁵I]RTI-55 (3β-(4-iodophenyl)tropan-2β-carboxylic acid methyl ester), a phenyl tropane analog of cocaine, and the selective labelling of the dopamine transporter (DAT) were studied by in vitro and ex vivo autoradiography in the rat whole brain. Recent evidence has shown that RTI-55 binds to not only DAT but also serotonin transporter (5HTT). In the present study, in vitro autoradiography revealed that [¹²⁵I]RTI-55 bound to the olfactory tubercle, the caudate putamen, the accumbens nucleus, the midline and lateral geniculate nuclei of the thalamus, the hypothalamic nuclei, the substantia nigra compact part, the subthalamic nucleus, the ventral tegmental area, the superior colliculus, the dorsal raphe nucleus, and the facial nucleus. Further, in the presence of clomipramine, a selective ligand for 5HTT, [¹²⁵I]RTI-55 binding was remarkably inhibited in the midline and lateral geniculate nuclei of the thalamus, the hypothalamic nuclei, the superior colliculus, the dorsal raphe nucleus, and the facial nucleus, while [¹²⁵I]RTI-55 binding remained in the olfactory tubercle, the caudate putamen, the accumbens nucleus, the substantia nigra compact part, the subthalamic nucleus, and the ventral tegmental area. These findings suggest that [¹²⁵I]RTI-55 binds to 5HTT in the former areas and to DAT in the latter areas. It is therefore concluded that RTI-55 is a suitable ligand for studying the action of cocaine in whole brain regions, including the thalamus, the hypothalamus and the dorsal raphe nucleus, regions in which cocaine is thought to act evoking several neurological effects, e.g., analgesia and elevation of adrenocorticotropic hormone. DAT was also labelled selectively both in vitro and in vivo using [¹²⁵I]RTI-55 combined with clomipramine. Therefore, radiolabelled RTI-55, combined with unlabelled clomipramine, which displaces its binding to 5HTT, also appears to be suitable for the selective imaging of DAT in vivo.     

Peroxyl radical scavenging capability of fish sauces measured by the chemiluminescence method

Oxygen-related free radicals have been suggested as a cause of aging and various diseases, for example, various cancers and rheumatoid arthritis. A radical scavenger as an antioxidant has been sought in foods. Fish sauces are traditional Asian fermented seasonings. Using the luminol chemiluminescence method, the peroxyl radical scavenging capability of fish sauces was examined. From the IC50 values, many fish sauces have been shown to have a strong scavenging capability as well as soy sauces. A scavenging mechanism is also proposed.