The maternal nudel protein of Drosophila has two distinct roles important for embryogenesis

The nudel gene is maternally required to define dorsoventral polarity of the Drosophila embryo. It encodes an unusual mosaic protein with a protease domain that may trigger the protease cascade required for ventral development. We describe phenotypic and molecular analyses of nudel mutations that provide further insight into nudel protein function. Surprisingly, nudel mutations primarily cause either dorsalized embryos in which dorsal cell fates are expanded over ventral and lateral cell fates or fragile eggs that fail to develop beyond early embryonic stages. The nudel protein is therefore required not only for embryonic dorsoventral polarity but also for structural integrity of the egg. Complementation and antagonistic interactions between nudel alleles suggest that the nudel protein is functionally modular and that protein-protein interactions are important for nudel protein function. Three nudel mutations that produce dorsalized embryos map to the protease domain of nudel, suggesting that this domain is specifically required for defining embryonic dorsoventral polarity. Finally, certain combinations of nudel alleles simultaneously produce completely dorsalized and normal embryos yet very few embryos of intermediate mutant phenotypes. The unusual biphasic distribution of phenotypes may indicate that nudel activity above a threshold is required to generate embryonic dorsoventral polarity.     

Analysis of the genes encoding the variable regions of human IgG rheumatoid factor

OBJECTIVE: To better understand the immunoglobulin variable (V) region repertoire of rheumatoid factors (RF). METHODS: We characterized the heavy (H) and light (L) chain gene segments utilized in a monospecific IgG RF secreting hybridoma (AEE111F) which were derived from a patient with rheumatoid arthritis (RA). The hybridoma was established by fusion of a mouse myeloma cell line with bone marrow derived mononuclear cells from a patient with RA. First strand complementary DNA (cDNA) was generated and used for a polymerase chain reaction amplification of the H and L chain V domains. The amplified V domains were sequenced and compared with an extensive database of germline and cDNA V gene segments. RESULTS: The VH sequence was found to be 96% homologous to a previously described fetal VH3 cDNA (60P2). The VL sequence was also highly homologous to the previously described V lambda II gene (96%) derived from a patient with systemic lupus erythematosus which correlated with an 8.12 idiotype (Id), and to an antibacterial antibody against the Haemophilus influenzae type b capsular polysaccharide (94.7%). CONCLUSION: The overlap among this RF VL gene and the 2 reported V lambda sequences of antibodies that expressed anti-DNA related Id and an environmental pathogen specificity suggests that a part of the IgG RF isolated from patients with RA may thus be derived from the physiological natural antibody repertoire during an abnormal immune response and then develop high affinity, monospecific RF by the selection of an antigen driven mechanism.     

Environmental effect on room- temperature ductility of isothermally forged tial- base alloys

Isothermally forged TiAl-base alloys (Al-rich, Mn-containing, and Cr-containing TiAl) were heat-treated in various conditions, and equiaxed grain structures consisting of γ and α₂ or Β phases were obtained. The heat-treated alloys were tensile tested in vacuum and air at room temperature, and the environmental effect on tensile elongation was studied. The ductility of the alloys consisting of equiaxed γ grains and a large amount of α₂ grains was not largely affected by laboratory air, and a decrease in the amount of α₂ grains resulted in a large reduction of ductility in air. The Β phase in the Cr-containing alloy improved the ductility in vacuum, but it resulted in a large reduction of ductility in air. Formerly with Kougakuin University, Shinjyuku-ku, Tokyo, Formerly with National Research Institute for Metals, Meguro-ku, Tokyo,     

Intra-arterial preventive chemotherapy for residual liver after resection of hepatic metastasis from colorectal cancer

We treated 18 cases with intra-hepatic arterial infusion chemotherapy after resection of hepatic metastasis from colorectal cancer (June 1991-September 1997). Eight cases were H1, 7 were H2, and 3 were H3. Hepatic lobectomy was done in 3 cases, lobectomy + partial resection in 2 cases, and partial resection in 13 cases. All cases received high-dose intermittent 5-FU infusion (WHF = 5-FU 1,000 mg/m2/5 hrs/w) on an outpatient basis. The total frequency of WHF was 4-54 times (average 29), and total 5-FU doses ranged from 6.0 to 81.0 g (average 40 g). The 1- and 5-year cumulative survival rates were 100% and 77.5% in all patients 100% and 87.5% in H1 group and 100% and 64.3% in H2 + H3 group, respectively. There was no significant difference of survival between the H1 and H1 + H3 groups. The 1- and 5-year recurrence rates in residual liver were 5.9% and 14.4%, respectively. One of 2 cases with residual liver recurrence was resected for metastasis again, and the patient is now in a disease-free state. WHF after resection of hepatic metastasis from colorectal cancer has a preventive effect for their survival, not only in H1 group but also in H2 + H3 group.     

Loss of H19 imprinting and up-regulation of H19 and SNRPN in a case with malignant mixed Müllerian tumor of the uterus

An unusual clinical presentation of a patient with neuronal intestinal dysplasia is presented. A 46-year-old male noted a palpable mass in the right lower quadrant of his abdomen for two months. A computed axial tomographic scan showed a thickened wall of the cecum with a tumor-like appearance. The excised specimen consisted of a mass caused by the thickened, edematous wall of the dilated cecum and appendix. The wall of the cecum and appendix measured up to 2.5 and 0.8 cm, respectively, in thickness. Microscopic studies showed extensive hyperplasia and hypertrophy of the ganglia and nerve plexuses and hypertrophy of the muscularis propria, consistent with neuronal intestinal dysplasia.     

Instrumentation for dual-probe scanning near-field optical microscopy

To investigate local carrier motions, we developed a dual-probe scanning near-field optical microscope (SNOM) with two fiber probes where one is for photoexcitation and the other is for light collection. This instrumentation is based on two important techniques: the design of probe structures and distance control between the sample surface and the two probes. A finite-difference time-domain method numerically analyzed and optimized the design for high efficiency photoexcitation and light collection, while a dual band modulation realized distance control. Real time detection of the oscillations of the probe tips using different frequencies independently controls the distance between the probe tip and the sample surface as well as the distance between the two probes. Thus, the collection probe can be scanned around an illumination probe without destroying the probe tips. To demonstrate our SNOM, we performed photoluminescence spectroscopy under the dual-probe configuration and observed carrier motions in an InGaN quantum well.     

Preparation of Porous Cr3C2 Grains with Cr2O3

Porous Cr₃C₂ grains (∼300 to 500 μm) with ∼10 wt% of Cr₂O₃ were prepared by heating a mixture of MgCr₂O₄ grains and graphite powder at 1450° to 1650°C for 2 h in an Al₂O₃ crucible covered by an Al₂O₃ lid with a hole in the center. The porous Cr₃C₂ grains exhibited a three-dimensional network skeleton structure. The mean open pore diameter and the specific surface area of the porous grains formed at 1600°C for 2 h were ∼3.5 (μm and ∼6.7 m²/g, respectively. The present work investigated the morphology and the formation conditions of the porous Cr₃C₂ grains, and this paper will discuss the formation mechanism of those grains in terms of chemical thermodynamics.     

High-speed melt spinning of bicomponent fibers: Mechanism of fiber structure development in poly(ethylene terephthalate)/polypropylene system

High-speed bicomponent spinning of poly(ethylene terephthalate)(PET)(core) and poly-propylene (PP) (sheath) was carried out and the structure development in the individual components, PET and PP, was investigated. The orientation and crystallinity development in the PET component was enhanced as compared to that of the single-component spinning while the PP component remained in a low orientation state and had a pseudohexagonal crystal structure even at high take-up speeds. To clarify the mutual interaction between the two components in bicomponent spinning, a semiquantitative numerical simulation was performed. The simulation results obtained using the Newtonian fluid model showed that the solidification stress in the PET component was enhanced while that of the PP component was decreased in comparison with the corresponding single-component spinning. This is due to the difference in the temperature dependence of their elongational viscosity. Simulation with an upper-convected Maxwell model as the constitutive equation suggested that significant stress relaxation of the PP component can occur in the spinline if the PET component solidifies earlier than does PP. Based on the structural characterization results, and the simulation results, it was concluded that the difference in the activation energy of the elongational viscosity and solidification temperature between the two polymers are the main factors influencing the mutual interaction in the bicomponent spinning process. © 1996 John Wiley & Sons, Inc.