Colored Fluorescent Silk Made by Transgenic Silkworms

Silk is a protein fiber used to weave fabrics and as a biomaterial in medical applications. Recently, genetically modified silks have been produced from transgenic silkworms. In the present study, transgenic silkworms for the mass production of three colors of fluorescent silks, (green, red, and orange) are generated using a vector originating from the fibroin H chain gene and a classical breeding method. The suitability of the recombinant silks for making fabrics is investigated by harvesting large amounts of the cocoons, obtained from rearing over 20 thousand silkworms. The application of low temperature and a weakly alkaline solution for cooking and reeling enables the production of silk fiber without loss of color. The maximum strain tolerated and Young's modulus of the fluorescent silks are similar to those of ordinary silk, although the maximum stress value of the recombinant silk is slightly lower than that of the control. Fabrics with fluorescent color are demonstrated using the recombinant silk, with the color persisting for over two years. The results indicate that large amounts of genetically modified silk can be made by transgenic silkworms, and the silk is applicable as functional silk fiber for making fabrics and for use in medical applications.     

Proteolysis of the phage lambda CII regulatory protein by FtsH (HflB) of Escherichia coli

BACKGROUND: It has been suggested that the expression of psychosis may reflect an active morbid process that is associated with increasingly poor outcome unless ameliorated by antipsychotic drugs. METHODS: The subjects of this study were 48 in-patients with schizophrenia, many of whom had been admitted before the introduction of antipsychotic drugs to rural Irish psychiatric hospitals in the late 1950s. Each patient was assessed for positive and negative symptoms, and for general and executive (frontal) cognitive function. RESULTS: After controlling for age and for duration and continuity of subsequent antipsychotic treatment, current severity both of negative symptoms and of general cognitive impairment was predicted strongly by increasing duration of initially untreated psychosis; duration of illness following initiation of antipsychotic medication failed to predict the severity thereof. Neither of these indices of illness duration predicted the severity of positive symptoms or of executive dyscontrol. CONCLUSIONS: Increasing duration of initially untreated psychosis was associated specifically with heightened accrual of prominent negative symptoms and general cognitive impairment. Executive dyscontrol, though also prominent in these patients, may be 'locked-in' at an earlier phase of the illness.     

A study on the accuracy of surface charge measurement

The measurement of accumulated surface charge for thick specimens requires multipoint probe outputs to establish the inverse calculation for the determination of an unknown charge distribution. Until now, studies on the various errors associated with the measurement have been conducted only for simplified arrangements mainly in axisymmetric geometry where the charged surface is parallel to the ground. We have numerically analyzed a model measurement set-up more comparable to practical conditions by a highly efficient surface charge method. We have studied the effect of probe position, the induction from charge existing not directly beneath the (probe) sensor and the difference in matrix components computed by two numerical methods. In particular, we have studied the accuracy of the reconstructed charge distributions by numerical simulations of the inverse calculation. It has been shown that the assumed measurement errors make much larger differences in the reconstructed charge distributions, although the influence depends considerably on the assumed charge distribution. Reducing the condition number of the matrix improves the accuracy of the inverse calculation for uniform and linearly changing charge distributions     

Reducing future CO2 emissions — The role of nuclear energy

A study was made to analyze the potential of reducing CO₂ emissions and to identify important energy and technology options in future energy systems of Japan. The energy market optimum allocation model MARKAL was used for the analysis with a time horizon from 1990 to 2050.

The analytical procedures were as follows. First, a reference energy system was established by incorporating all important energy sources, energy carriers, and energy technologies that existed already or that might be introduced during the above time horizon. Second, future demand for energy services was estimated based on the two economic growth scenarios, high and low. Also, assumptions were made about the evolution of imported fuel prices, availability of energy resources, and so on. Third, under the above assumptions, the optimum energy and technology options were selected by minimizing a discounted system cost under different carbon tax schemes, and thereby the potential of reducing CO₂ emissions was analyzed.

The following results were obtained by the analysis. Without utilization of nuclear energy, the CO₂ emissions can be hardly stabilized at the 1990 emission level even in the case of the low economic growth and large scale deployment of CO₂ recovery and disposal assumed. A significant amount of fossil fuels will be used for power generation in order to meet the rapidly growing demand for electricity. Nuclear energy, by substituting fossil fuels for electric power generation, is expected to contribute to the reduction of CO₂ emissions. In addition, the average cost of reducing the emissions will be substantially lowered compared with a non nuclear scenario.     

Neuroblastoma growth factors derived from neurofibroma (NF1): participation of uridine in a neuroblastoma growth

Human glioma cell extracts were found to elicit a marked growth-promoting activity on human neuroblastoma cells. This activity was also detected in the extracts of neurofibroma type 1 (NF1; von Recklinghausen neurofibromatosis) comprising aberrant Schwann cell growth. The purified substance from the NF1 extracts by HPLC on ODS columns was identical to a pyrimidine nucleoside, uridine, the chemical structure of which was identified by gas chromatography-mass spectrometry. The authentic uridine showed a strong growth-promoting activity on human neuroblastoma cells. Other purine or pyrimidine nucleotides, their derivatives, and ribose sources for their syntheses were employed to test the activity; a purine nucleoside, adenosine, showed a stronger activity than uridine. The current study raises the possibility that human neuroblastoma cells may be affected by dysfunctions of the de novo pathway of both purine and pyrimidine nucleotide biosyntheses.     

Clonal analysis of urothelial carcinomas in C3H/HeN<-->BALB/c chimeric mice treated with N-butyl-N-(4-hydroxybutyl)nitrosamine

The histological background for multifocal and metachronous development of urothelial carcinomas remains equivocal, although accumulated genetic evidence suggests monoclonal origin of multiple urothelial carcinomas. Clonal development of various preneoplastic and neoplastic urothelial lesions of C3H<-->BALB/c chimeric mice induced by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) was immunohistochemically investigated using a C3H strain-specific antibody. All tumor masses induced in the mice treated with 0.05% BBN for 20 weeks were composed of neoplastic cells of a single parental type, which is indicative of monoclonal lesions. Three of 10 animals harbored two or more separate carcinomas of different clonal type, which is indicative of multicentric development applicable in this model. Using DNAs derived from urothelial carcinomas and tumor-adjacent urothelium of chimeric mice, polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and direct sequencing were performed for p53 gene exons 5-7. p53 mutations were identified in four of 11 (36%) dysplasias and non-invasive carcinomas (carcinoma in situ and pTa tumor) and 13 of 22 (59%) invasive carcinomas. Only in a single case were identical p53 mutations found in separate urinary bladder carcinomas. In contrast to the random distribution of urothelial proliferating units in chimeric mice without chemical supplement, invasive carcinomas in BBN-treated mice were accompanied by widely-distributed preneoplastic and neoplastic lesions of the same clonality, which occasionally had frequent foci of microinvasion. This is indicative of lateral clonal expansion of the clones, which precedes the bulk of invasive carcinomas. Thus, two aspects of 'field change' of the urothelium became evident in this model: either independent transformation events or lateral clonal expansion might, respectively, result in multicentric and monoclonal carcinoma development in the urinary tract.     

Optimal surface chemistry for peptide immobilization in on-chip phosphorylation analysis

We investigated the optimal surface chemistry of peptide immobilization for on-chip phosphorylation analysis. In our previous study, we used a heterobifunctional cross-linker sulfosuccinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxalate (SSMCC) to immobilize cysteine-terminated peptides on an amine-modified gold surface. The study revealed that the phosphorylation efficiency and rate were low (only 20% at 2 h) comparing with the reaction in solution. In this study, to improve the phosphorylation efficiency, the kinase substrates were immobilized via poly(ethylene glycol) (PEG), a flexible, hydrophilic polymer. An improvement in cSrc phosphorylation was achieved (60% at 1 h) from using a PEG-inserted peptide and SSMCC. However, no phosphorylation could be detected when the peptide was immobilized with a PEG-containing cross-linker. Fluorescence-labeled peptide studies revealed that the use of longer cross-linkers resulted in lower immobilization density. We considered that the flexible PEG linker was preferable to secure high phosphorylation efficiency for the immobilized peptide, probably due to the improvement of cSrc accessibility and peptide mobility, but the immobilization protocol is critical for keeping high density of the peptide immobilization. In addition, such an accelerating effect of PEG linker against on-chip phosphorylation of an immobilized peptide may depend on kinase structures or the position of the active center, because no improvement of on-chip peptide phosphorylation was observed in protein kinase A. However, PEG linker also did not suppress the phosphorylation in protein kinase A. Thus, we concluded that SSMCC and PEGylated peptide will be a good combination for the surface chemistry of on-chip phosphorylation in peptide array.     

A New Route to Perfluoro(Propyl Vinyl Ether) Monomer: Synthesis of Perfluoro(2‐propoxypropionyl) Fluoride from Non‐Fluorinated Compounds

Perfluoro(2‐propoxypropionyl) fluoride ( 1a ), which is the precursor of the perfluorinated propyl vinyl ether (PPVE) monomer of an industrially important perfluoroalkoxy copolymer (PFA), was synthesized by utilizing direct fluorination of the non‐fluorinated counterpart for the first time. The partially‐fluorinated ester 7 synthesized from the desired perfluorinated acid fluoride 1a itself and the non‐fluorinated alcohol 5 , which has a carbon skeleton corresponding to the desired compound 1a , was perfluorinated by liquid‐phase direct fluorination with elemental fluorine. Degradation of the resulting perfluorinated ester 8 gave 2 mols of the desired acid fluoride 1a . In a sense, this process can be called self‐multiplication of a perfluorinated acid fluoride from a non‐fluorinated alcohol.