Phototropic fluence-response curves for Pilobolus crystallinus sporangiophore

Fluence-response relationships were examined for positive and negative phototropism induced by blue (450 nm) and ultraviolet-B (UV-B, 280 nm) light, respectively, in the Pilobolus crystallinus sporangiophore. Fluence-response curves for both blue and UV-B light obtained by changing the fluence by varying exposure time only showed the classical first and second positive bending. However, fluence-response curves obtained by varying the fluence rate were bell-shaped irrespective of the length of the exposure time. With increasing exposure time the peak became higher along the ascendant arm and the descendant arm was shifted toward the higher fluence. The Bunsen-Roscoe reciprocity law was valid only when the fluence was less than approx. 400 pmol·m^-2 for both blue and UV-B light. Because the shapes of the fluence-response curves for blue and UV-B light were nearly the same, the photoreceptor systems for both blue and UV-B light are considered to be the same.Abbreviation UV-B ultraviolet-B     

Monoclonal Antibodies Specific for NADH-Ferricyanide Reductase Domain of Spinach Leaf Nitrate Reductase

Two monoclonal antibodies, 17(3)9 and 36(79)4, were preparedagainst nitrate reductase from Spinacia oleracea L. leaves.An enzyme-linked immunosorbent assay showed that 17(3)9, butnot 36(79)4, reacted more strongly to heat-denatured than nativeantigen. These antibodies inhibited NADH-nitrate reductase aswell as its various partial activities including reduced methylvilogen-nitrate reductase, reduced flavin mononucleotide-nitratereductase and NADH-cytochrome c reductase activities, but notNADH-ferricyanide reductase activity. Immunoblotting after electrophoreticseparation of nitrate reductase fragments obtained by Staphyrococcusaureus V8 protease digestion of native enzyme revealed thatthe two monoclonal antibodies bind to different epitopes locatedon the 28 kDa of the NADH-ferricyanide reductase domain. (Received October 2, 1987; Accepted June 9, 1988)     

Effects of ingested phytoecdysteroids on the growth and development of two Lepidopterous larvae

The effects of ingested or injected 20-hydroxyecdysone on silkworm larvae (Bombyx mori) including death without moulting, death following completion of promoted moulting, death during promoted moulting (ecdysis inhibition) and inhibition in growth with and without effects on moulting, are dependent upon the concentration of exogenous hormone, the precise developmental stage of the treated larvae, and the duration of exposure to the exogenous ecdysteroid. Comparisons of 20-hydroxyecdysone with other phytoecdysteroids in the silkworm and pink bollworm, Pectinophora gossypiella, show a similar but more potent effect induced by ponasterone A, while cyasterone causes an ‘antiecdysone’ effect.     

Effect of hip joint angle at seat-off on hip joint contact force during sit-to-stand movement: a computer simulation study

Background

Sit-to-stand movements are a necessary part of daily life, and excessive mechanical stress on the articular cartilage has been reported to encourage the progression of osteoarthritis. Although a change in hip joint angle at seat-off may affect hip joint contact force during a sit-to-stand movement, the effect is unclear. This study aimed to examine the effect of the hip joint angle at seat-off on the hip joint contact force during a sit-to-stand movement by using a computer simulation.

Methods

A musculoskeletal model was created for the computer simulation, and eight muscles were attached to each lower limb. Various sit-to-stand movements were generated using parameters (e.g., seat height and time from seat-off to standing posture) reported by previous studies. The hip joint contact force for each sit-to-stand movement was calculated. Furthermore, the effect of the hip joint angle at seat-off on the hip joint contact force during the sit-to-stand movement was examined. In this study, as the changes to the musculoskeletal model parameters affect the hip joint contact force, a sensitivity analysis was conducted.

Results and conclusions

The hip joint contact force during the sit-to-stand movement increased approximately linearly as the hip flexion angle at the seat-off increased. Moreover, the normal sit-to-stand movement and the sit-to-stand movement yielding a minimum hip joint contact force were approximately equivalent. The effect of the changes to the musculoskeletal model parameters on the main findings of this study was minimal. Thus, the main findings are robust and may help prevent the progression of hip osteoarthritis by decreasing mechanical stress, which will be explored in future studies.

     

Mitogen activation of human chronic lymphatic leukemia cells. I. Synthesis and secretion of immunoglobulin.

The response of CLL (chronic lymphatic leukemia) lymphocytes to PHA, PWM, and Con A with respect to changes in surface markers and synthesis and secretion of immunoglobulin were examined. After PHA stimulation the percentage of cells bearing readily detectable surface immunoglobulin (SmIg) diminished rapidly whereas cells forming rosettes with sheep erythrocytes (E-rosettes) increased from less than 1% to 30 to 50%. The great majority of blast-transformed cells were E-rosette-positive cells with a small population of SmIg-positive blast cells also observed. Ig production in four of seven CLL lymphocyte populations was increased 2.5 to greater than 40-fold after 4 to 6 days of culture in the presence of PHA. In contrast, pokeweed mitogen did not affect Ig synthesis. Furthermore, the Ig secreted into the culture supernatant fluids from seven of eight CLL cases examined consisted almost entirely of free light chain molecules. In contrast, the cell lysates contained a significant proportion of intact Ig molecules. These results indicate that CLL cells can, under certain circumstances, be stimulated to synthesize and secrete increased amounts of Ig, but that there is a basic defect in the biosynthetic mechanism of these cells which result in the secretion of free light chains rather than intact immunoglobulin molecules.     

Mouse genetics identifies unique and overlapping functions of fibroblast growth factor receptors in keratinocytes

Fibroblast growth factors (FGFs) are key regulators of tissue development, homeostasis and repair, and abnormal FGF signalling is associated with various human diseases. In human and murine epidermis, FGF receptor 3 (FGFR3) activation causes benign skin tumours, but the consequences of FGFR3 deficiency in this tissue have not been determined. Here, we show that FGFR3 in keratinocytes is dispensable for mouse skin development, homeostasis and wound repair. However, the defect in the epidermal barrier and the resulting inflammatory skin disease that develops in mice lacking FGFR1 and FGFR2 in keratinocytes were further aggravated upon additional loss of FGFR3. This caused fibroblast activation and fibrosis in the FGFR1/FGFR2 double‐knockout mice and even more in mice lacking all three FGFRs, revealing functional redundancy of FGFR3 with FGFR1 and FGFR2 for maintaining the epidermal barrier. Taken together, our study demonstrates that FGFR1, FGFR2 and FGFR3 act together to maintain epidermal integrity and cutaneous homeostasis, with FGFR2 being the dominant receptor.     

Induced pluripotent stem cell‐derived myeloid cells expressing OX40 ligand amplify antigen‐specific T cells in advanced melanoma

Immune checkpoint inhibitors improved the survival rate of patients with unresectable melanoma. However, some patients do not respond, and variable immune‐related adverse events have been reported. Therefore, more effective and antigen‐specific immune therapies are urgently needed. We previously reported the efficacy of an immune cell therapy with immortalized myeloid cells derived from induced pluripotent stem cells (iPS‐ML). In this study, we generated OX40L‐overexpressing iPS‐ML (iPS‐ML‐Zsgreen‐OX40L) and investigated their characteristics and in vivo efficacy against mouse melanoma. We found that iPS‐ML‐Zsgreen‐OX40L suppressed the progression of B16‐BL6 melanoma, and prolonged survival of mice with ovalbumin (OVA)‐expressing B16 melanoma (MO4). The number of antigen‐specific CD8⁺ T cells was higher in spleen cells treated with OVA peptide‐pulsed iPS‐ML‐Zsgreen‐OX40L than in those without OX40L. The OVA peptide‐pulsed iPS‐ML‐Zsgreen‐OX40L significantly increased the number of tumor‐infiltrating T lymphocytes (TILs) in MO4 tumor. Flow cytometry showed decreased regulatory T cells but increased effector and effector memory T cells among the TILs. Although we plan to use allogeneic iPS‐ML in the clinical applications, iPS‐ML showed the tumorgenicity in the syngeneic mice model. Incorporating the suicide gene is necessary to ensure the safety in the future study. Collectively, these results indicate that iPS‐ML‐Zsgreen‐OX40L therapy might be a new method for antigen‐specific cancer immunotherapy.     

Knock Out of S1P3 Receptor Signaling Attenuates Inflammation and Fibrosis in Bleomycin-Induced Lung Injury Mice Model

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid metabolite involved in many critical cellular processes, including proliferation, migration, and angiogenesis, through interaction with a family of five G protein–coupled receptors (S1P1–5). Some reports have implicated S1P as an important inflammatory mediator of the pathogenesis of airway inflammation, but the role of S1P3 in the pathogenesis of lung diseases is not completely understood. We used S1P3-deficient (knockout (KO)) mice to clarify the role of S1P3 receptor signaling in the pathogenesis of pulmonary inflammation and fibrosis using a bleomycin-induced model of lung injury. On the seventh day after bleomycin administration, S1P3 KO mice exhibited significantly less body weight loss and pulmonary inflammation than wild-type (WT) mice. On the 28th day, there was less pulmonary fibrosis in S1P3 KO mice than in WT mice. S1P3 KO mice demonstrated a 56% reduction in total cell count in bronchoalveolar lavage fluid (BALF) collected on the seventh day compared with WT mice; however, the differential white blood cell profiles were similar. BALF analysis on the seventh day showed that connective tissue growth factor (CTGF) levels were significantly decreased in S1P3 KO mice compared with WT mice, although no differences were observed in monocyte chemotactic protein-1 (MCP-1) or transforming growth factor β1 (TGF-β1) levels. Finally, S1P levels in BALF collected on the 7th day after treatment were not significantly different between WT and S1P3 KO mice. Our results indicate that S1P3 receptor signaling plays an important role in pulmonary inflammation and fibrosis and that this signaling occurs via CTGF expression. This suggests that this pathway might be a therapeutic target for pulmonary fibrosis.     

A novel difucosylated neutral glycosphingolipid from the eggs of the sea urchin, Hemicentrotus pulcherrimus: I. Purification and structural determination of the glycolipid.

A novel fucose-containing neutral glycosphingolipid (GL-5) was purified from the eggs of the sea urchin, Hemicentrotus pulcherrimus. The chemical structure was determined to be Fuc alpha 1-3GalNAc beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-4Glc beta 1-1Cer by methylation analysis, partial acid hydrolysis, fast atom bombardment mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The unique characteristics of GL-5 are that: the reducing terminal disaccharide portion is not Gal beta 1-4Glc but GlcNAc beta 1-4Glc; it includes a GalNAc beta 1-4GlcNAc sequence and a Fuc-GalNAc linkage; the defucosylated core is a novel trisaccharide chain; and the sugar structure is one of the smallest ever characterized for a difucosylated glycolipid. The major fatty acids were 22:1 and 22h:1, and about 30% of the total acids was 2-hydroxylated. All the long-chain bases were phytosphingosines, of which about 90% was n-t18:0. The similarity of the ceramide moiety to that of glucosylceramide from the same eggs [Kubo, H. et al. (1992) J. Biochem. 111, 726-731] suggests a close biosynthetic relationship between GL-5 and the glucosylceramide.