Evaluation of varicella vaccine in childhood leukemia. Observation over 6 years

Since 1977, we have used a live attenuated varicella vaccine to immunize 10 children with acute leukemia. 8 patients had no adverse clinical reaction but 2 patients developed mild fever and papulovesicular rash after vaccination. All 9 tested children became seropositive after the vaccination. Also in all 3 children who were observed for more than 4 years, persistence of neutralizing antibody was detected. Most of the recipients were prevented from developing symptoms of varicella in spite of contact exposure. Two patients developed varicella when they were in severe immunosuppressive states but their symptoms were mild. None of the children developed herpes-zoster during the 6 year follow-up period. The results suggest that the varicella vaccine is effective in children with acute leukemia, and that long-term effectiveness can be expected.     

Novel Genetic Resources in the Genus Vigna Unveiled from Gene Bank Accessions

The genus Vigna (Fabaceae) consists of five subgenera, and includes more than 100 wild species. In Vigna, 10 crops have been domesticated from three subgenera, Vigna, Plectrotropis, and Ceratotropis. The habitats of wild Vigna species are so diverse that their genomes could harbor various genes responsible for environmental stress adaptation, which could lead to innovations in agriculture. Since some of the gene bank Vigna accessions were unidentified and they seemed to be novel genetic resources, these accessions were identified based on morphological traits. The phylogenetic positions were estimated based on the DNA sequences of nuclear rDNA-ITS and chloroplast atpB-rbcL spacer regions. Based on the results, the potential usefulness of the recently described species V. indica and V. sahyadriana, and some wild Vigna species, i.e., V. aconitifolia, V. dalzelliana, V. khandalensis, V. marina var. oblonga, and V. vexillata, was discussed.     

Molecular feature of the nerve growth factor in human serum

High molecular weight binding components which bind [¹²⁵I] mouse β nerve growth factor exist in human serum. The binding of β nerve growth factor to the serum components was inhibited at alkaline condition. After gel filtration of human serum on a Sephadex G-150 column at neutral condition, the nerve growth factor-like immunoreactivity was observed in only one peak, differing from the high molecular weight serum components. However, at alkaline condition two peaks with nerve growth factor-like immunoreactivity appeared; one was almost at the position observed at neutral pH, and the other was a new peak eluted approximately to the column volume. these results suggest that there are at least two nerve growth factor-like molecules in human serum and most of the nerve growth factor in the serum exists in a complex form associated with serum components with high molecular weight.     

Rapid identification of Plasmodium-carrying mosquitoes using loop-mediated isothermal amplification

With an aim to develop a quick and simple method to survey pathogen-transmitting vectors, LAMP (loop-mediated isothermal amplification) was applied to the identification of Plasmodium-carrying mosquitoes, specifically a Plasmodium-transmitting experimental model using rodent malaria parasite (Plasmodium berghei) and anopheline mosquitoes (Anopheles stephensi). The detection sensitivity limit of the LAMP reaction amplifying the SPECT2 gene was determined to be 1 × 10² purified Plasmodium parasites, estimated to be sufficient for reliable identification of infectious mosquitoes. The robustness of the LAMP reaction was revealed by its ability to detect both Plasmodium oocysts and sporozoites from an “all-in-one” template using whole mosquito bodies. Moreover, LAMP successfully identified an infectious mosquito carrying just a single oocyst in its midgut, a level that can be easily overlooked in conventional microscopic analysis. These observations suggest that LAMP is more reliable and useful for routine diagnosis of vector mosquitoes in regions where vector-borne diseases such as malaria are endemic.     

4-Hydroxydocosahexaenoic acid, a potent peroxisome proliferator-activated receptor gamma agonist alleviates the symptoms of DSS-induced colitis

(5E,7Z,10Z,13Z,16Z,19Z)-4-Hydroxy-5,7,10,13,16,19-docosahexaenoic acid (4-OHDHA) is a potential agonist of peroxisome proliferator-activated receptor-γ (PPARγ) and antidiabetic agent as has been previously reported. As PPARγ agonists may also have anti-inflammatory functions, in this study, we investigated whether 4-OHDHA has an inhibitory effect on expression of inflammatory genes in vitro and whether 4-OHDHA could relieve the symptoms of dextran sodium sulfate (DSS)-induced colitis in a murine model of inflammatory bowel disease. 4-OHDHA inhibited production of nitric oxide and expression of a subset of inflammatory genes including inducible nitric oxide synthase (Nos2/iNOS) and interleukin 6 (Il6) by lipopolysaccharide (LPS)-activated macrophages. In addition, 4-OHDHA-treated mice when compared to control mice not receiving treatment recovered better from the weight loss caused by DSS-induced colitis. Changes in disease activity index (DAI) of 4-OHDHA-treated mice were also more favorable than for control mice and were comparable with mice treated with a typical anti-inflammatory-drug, 5-aminosalichylic acid (5-ASA). These results suggest that 4-OHDHA has potentially clinically useful anti-inflammatory effects mediated by suppression of inflammatory gene expression.     

Connexin 43 contributes to differentiation of retinal pigment epithelial cells via cyclic AMP signaling

Retinal pigment epithelium (RPE) cells play important roles in the visual system that supports neurosensory retina homeostasis. Connexin (Cx) 43-mediated gap-junctional intercellular communication (GJIC) participates in the regulation of retinal organogenesis, but much of the function of Cx43 on the differentiation of RPE cells is unclear. Here, we report the involvement of Cx43 in RPE differentiation. Knockdown of Cx43 in RPE cells dramatically inhibited the differentiation, whereas Cx43-overexpression successfully induced RPE cell differentiation under de-differentiation conditions. From the experiments using GJIC inhibitors and C-terminus-truncated mutant of Cx43, it was clearly demonstrated that the regulation of RPE cell differentiation by Cx43 did not result from Cx43-mediated GJIC. The RPE cell differentiation induced by Cx43-overexpression was abolished by a cAMP antagonist. In contrast, the treatment with forskolin and phosphodiesterase inhibitor rolipram induced RPE cell differentiation under de-differentiation conditions. These findings indicate that Cx43 contributes to RPE differentiation via cAMP signaling.     

Dynamic functional relay between insulin receptor substrate 1 and 2 in hepatic insulin signaling during fasting and feeding

Insulin receptor substrate (Irs) mediates metabolic actions of insulin. Here, we show that hepatic Irs1 and Irs2 function in a distinct manner in the regulation of glucose homeostasis. The PI3K activity associated with Irs2 began to increase during fasting, reached its peak immediately after refeeding, and decreased rapidly thereafter. By contrast, the PI3K activity associated with Irs1 began to increase a few hours after refeeding and reached its peak thereafter. The data indicate that Irs2 mainly functions during fasting and immediately after refeeding, and Irs1 functions primarily after refeeding. In fact, liver-specific Irs1-knockout mice failed to exhibit insulin resistance during fasting, but showed insulin resistance after refeeding; conversely, liver-specific Irs2-knockout mice displayed insulin resistance during fasting but not after refeeding. We propose the concept of the existence of a dynamic relay between Irs1 and Irs2 in hepatic insulin signaling during fasting and feeding.     

Placental folate transport during pregnancy

The aim of this study was to elucidate the mechanism of folate transport in the placenta over the course of pregnancy. We found that folate receptor alpha (FRalpha) and reduced folate carrier (RFC) localized on the apical side of human placental villi. Since folate binding to placental brush-border membrane vesicles (BBMVs) was strongly inhibited by phosphatidylinositol-specific phospholipase C (PI-PLC) treatment, it is possible that FRalpha, a glycosyl phosphatidylinositol linked glycoprotein, is a candidate for folate uptake from maternal blood to the placenta. Moreover, additional inhibitory effects of thiamine pyrophosphate (TPP) and hemin on folate uptake after PI-PLC treatment suggested that not only FRalpha but also RFC and heme carrier protein 1 (HCP1) are involved in the folate transport mechanism in the human placenta. It was also found that accumulation of folate after intravenous injection increased with the progress of gestation in the rat placenta and the fetus. Furthermore, increases in the expression levels of mRNA of rFRalpha, rRFC, and rHCP1 in the rat placenta during pregnancy were observed. These findings suggest that FRalpha, RFC, and HCP1 are important carriers of folate in the placenta during pregnancy. The results of this study suggest that increases in the expression levels of FRalpha, RFC, and HCP1 in the placenta play an important role in the response to increased need for folate for the placenta and fetus during development with the progress of gestation.     

Cell lineage in mammalian craniofacial mesenchyme

We have analysed the contributions of neural crest and mesoderm to mammalian craniofacial mesenchyme and its derivatives by cell lineage tracing experiments in mouse embryos, using the permanent genetic markers Wnt1-cre for neural crest and Mesp1-cre for mesoderm, combined with the Rosa26 reporter. At the end of neural crest cell migration (E9.5) the two patterns are reciprocal, with a mutual boundary just posterior to the eye. Mesodermal cells expressing endothelial markers (angioblasts) are found not to respect this boundary; they are associated with the migrating neural crest from the 5-somite stage, and by E9.5 they form a pre-endothelial meshwork throughout the cranial mesenchyme. Mesodermal cells of the myogenic lineage also migrate with neural crest cells, as the branchial arches form. By E17.5 the neural crest-mesoderm boundary in the subectodermal mesenchyme becomes out of register with that of the underlying skeletogenic layer, which is between the frontal and parietal bones. At E13.5 the primordia of these bones lie basolateral to the brain, extending towards the vertex of the skull during the following 4-5 days. We used DiI labelling of the bone primordia in ex-utero E13.5 embryos to distinguish between two possibilities for the origin of the frontal and parietal bones: (1) recruitment from adjacent connective tissue or (2) proliferation of the original primordia. The results clearly demonstrated that the bone primordia extend vertically by intrinsic growth, without detectable recruitment of adjacent mesenchymal cells.