Ozone increases root respiration but decreases leaf CO2 assimilation in cotton and melon

It is well established that exposure of plant foliage to tropospheric ozone (O3) inhibits photosynthetic gas exchange in leaves and the translocation of current photosynthate to sink tissues. It is less clear what impact O3-reduced source strength has on the physiological responses of sink tissue such as fine roots. The responses were investigated of carbon acquisition in leaves and carbon utilization in the respiration of fine roots, following chronic (weeks) and acute (hours) exposures to O3 in open top chambers. Previous reports indicate increased, decreased, and unchanged rates of root respiration following exposure to O3. A decline in source activity is confirmed, but an increase in sink respiration is reported in fine roots of Pima cotton (cv. S-6) and muskmelon (cv. Ambrosia hybrid). Leaf source strength and root sink activity changed in opposing directions, thus there was no positive correlation that might indicate direct substrate control of root function. Additional linkages between shoot and root following exposure to O3 may be involved.     

Inhibition of Rho/Rho-kinase signaling downregulates plasminogen activator inhibitor-1 synthesis in cultured human monocytes

Increased production of plasminogen activator inhibitor-1 (PAI-1) in plaques plays a role in the pathogenesis of atherosclerosis. This study was conducted to investigate the effect of blockade of Rho/Rho-kinase signaling on the synthesis of PAI-1 in cultured human peripheral blood monocytes. HMG-CoA reductase inhibitors (statins) and inhibitors of Rho and Rho-kinase were added to monocyte cultures. The levels of PAI antigen and mRNA were determined by Western blotting and RT-PCR, respectively, and PAI-1 expression was assessed by immunohistochemistry. We performed pull-down assays to determine the activity of Rho by measuring the GTP-bound form of Rho A. In unstimulated and lipopolysaccharide (LPS)-stimulated cultured monocytes, statins reduced the levels of PAI-1 antigen and mRNA. The suppressive effects of statins on PAI-1 synthesis were reversed by geranylgeranylpyrophosphate (GGPP) and were mimicked by C3 exoenzyme. Immunohistochemistry confirmed the role of lipid modification by GGPP in suppressive effect of statins in PAI-1 synthesis. Pull-down assays demonstrated that statins decreased the levels of the GTP-bound form of Rho A. Our findings suggest that statins decrease the activity of Rho by inhibiting geranylgeranylation. Moreover, Rho-kinase inhibitors, Y-27632 and fasudil, suppressed the synthesis of PAI-1 in this culture system. We show that inhibition of Rho/Rho-kinase signaling downregulates the synthesis of PAI-1 in human monocytes.     

The free deltoid flap: microscopic anatomy studies and clinical application to oral cavity reconstruction

The deltoid free flap is a fasciocutaneous flap that should be thin, hairless, of an adequate size, and capable of sensory reinnervation. Because of its excellent color-matching and texture-matching characteristics, it has recently been widely used for the reconstruction of soft-tissue defects during oral and maxillofacial surgery. Furthermore, a characteristic of oral and maxillofacial soft-tissue defects is that they are not large; therefore, flap size will be small, allowing the donor site to be directly closed. Because of natural variation in parts of the anatomy, there has sometimes been great difficulty in clinical application. The authors decided to study this by performing anatomical studies of the deltoid region on 21 cadavers. The result indicates that the pedicle of the deltoid free flap penetrates the "quadrangular space" in 90 percent of cases but passes and does not penetrate the quadrangular space in the remaining cases. The authors also confirmed that the skin has a vascular network comprising five layers and, furthermore, that the vascular network of the deep fascia is dense. The authors also report six cases of its clinical use complicated by anatomic variation and local infection in which the deltoid flap showed a completely successful outcome.     

Lysophospholipids transactivate HER2/neu (erbB-2) in human gastric cancer cells

The ligand-less receptor HER2/neu (erbB-2) has been proposed as a prognostic marker of gastric cancer that correlates with poor clinical outcome, indicating that HER2 signals play an important role in gastric cancer progression. This study demonstrated that two major natural lysophospholipids, lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P), induce rapid and transient phosphorylation of HER2 in two human gastric cancer cell lines, MKN28 and MKN74 cells. We also revealed that tyrosine phosphorylation of HER2 induced by both lysophospholipids was significantly attenuated by two inhibitors, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, AG1478, and a broad-spectrum matrix metalloproteinase inhibitor, GM6001. This suggests that the pathway of HER2 transactivation induced by these lysophospholipids is dependent on the proteolytically released EGFR ligands. Our results indicate that LPA and S1P act upstream of HER2 in gastric cancer cells, and thus may act as potent stimulators of gastric cancer.     

Species-specific color-pattern modifications of butterfly wings

We have previously shown that the systemic injection of sodium tungstate, a general protein-tyrosine phosphatase (PTPase) inhibitor, efficiently produces characteristic color-pattern modifications on the wings of the Painted Lady butterfly, Vanessa cardui. By using this method in the present study, we analyzed modification patterns of six species of Japanese butterflies. Whereas in Vanessa indica the black spots on the forewings reduced in size in response to the treatment, in Lycaena phlaeas the morphologically similar black spots enlarged in size. However, the metallic blue spots on the forewings of V. indica did enlarge in size, showing different behavior even within a single wing surface. The response patterns of Ypthima argus differed markedly from those of other species in that ectopic color-pattern elements were created. Colias erate showed minor modifications that coincidentally resembled the natural color-pattern of a closely related species, Colias palaeno. Through a comprehensive literature search, we confirmed the existence of naturally occurring aberrant color patterns with close similarities to the experimentally induced phenocopies in each of the modified species. Our results point out the possibility that a hypothetical transduction pathway with a PTPase for the scale-cell differentiation globally coordinates the wing-wide color-pattern development in butterflies.     

Color-pattern modifications and speciation in butterflies of the genus Vanessa and its related genera Cynthia and Bassaris

We have previously shown that the systemic injection of sodium tungstate, a protein-tyrosine phosphatase (PTPase) inhibitor, to pupae immediately after pupation efficiently produces characteristic color-pattern modifications on the wings of many species of butterflies including Vanessa indica and Cynthia cardui. In these species, the black spots reduced in size in response to the treatment. Similar modifications are occasionally seen in the field-caught aberrant individuals. Exceptionally, however, a C. cardui individual with enlarged black spots ("reversed" modification pattern) has been reported. Here we show that these modified patterns of V. indica and C. cardui are quite similar to the normal color-patterns of other Vanessa species. V. indica with tungstate-induced modifications resembled V. tameamea, V. samani, and Bassaris itea, whereas V. dilecta, V. atalanta, and V. dejeanii are similar to the "reversed" individual. Most features seen in the experimentally-modified V. indica were observed throughout the fore- and hindwings of V. samani. In contrast, the experimentally-induced color-patterns of C. cardui did not parallel variation of Cynthia butterflies. Since it has been proposed that a hypothetical transduction pathway with a PTPase for the scale-cell differentiation globally coordinates the wing-wide color-patterns, our findings suggest that spontaneous mutations in genes in this hypothetical pathway might have played a major role in creating new color-patterns and species in the Vanessa genus but not in the Cynthia genus. This evolutionary mechanism may probably be shared more widely in Lepidoptera, although this would not be a sole determinant for the color-pattern development and evolution.