Contribution of high p34cdc2 kinase activity to premature chromosome condensation of injected somatic cell nuclei in rat oocytes

The present study was undertaken to clarify the relationship between the p34cdc2 kinase activity of in vitro-aged or enucleated rat oocytes and the premature chromosome condensation (PCC) of microinjected cumulus cell nuclei. Wistar rat oocytes were placed in vitro up to 120 min after the animal was killed. The p34cdc2 kinase activity of the oocytes decreased in a time-dependent manner. The incidence of PCC was higher when nuclear injection into intact oocytes was completed in 15-45 min rather than 46-120 min. When rat oocytes were enucleated for subsequent nuclear injection, the p34cdc2 kinase activity transiently increased soon after enucleation but drastically decreased after 30 min. Removal of the cytoplasm instead of the meta-phase-plate did not affect the p34cdc2 kinase activity even after 60 min. PCC occurred in intact and cytoplasm-removed oocytes but not in enucleated oocytes. In contrast, oocytes from BDF1 mice exhibited a p34cdc2 kinase level twice that of rat oocytes and supported PCC despite enucleation. The p34cdc2 kinase level of intact rat oocytes was reduced to the equivalent level of aged (120 min) or enucleated (+60 min) oocytes by a 45 min treatment with roscovitine, an inhibitor of p34cdc2 kinase. None of the roscovitine-treated oocytes supported PCC while half of the control oocytes did. When rat oocytes were treated with MG132, a proteasome inhibitor, delayed inactivation of the p34cdc2 kinase was observed in the MG132-treated oocytes. A significantly higher proportion of the MG132-treated oocytes supported PCC when compared with the control oocytes. Moreover, a higher proportion of MG132-treated and enucleated oocytes carried two pseudo-pronuclei after cumulus cell injection and developed to the two-cell stage when compared with the enucleated oocytes at the telophase-II stage. These results suggest that the decreased level of p34cdc2 kinase activity in aged or enucleated rat oocytes is responsible for their inability to support PCC of microinjected donor cell nuclei and that inhibition of p34cdc2 kinase inactivation by chemicals such as MG132 is in part effective for rat oocytes to promote PCC and further development.     

Depression during interferon therapy in chronic hepatitis C patients--a prospective study

The number of patients treated with interferon (IFN) has increased markedly in Japan since 1992, when the Health and Welfare Ministry approved the use of IFN for treating chronic active hepatitis C. It is important to identify and treat depression, which is one of the psychiatric complications of IFN therapy and often leads to discontinuation of the therapy, in patients with chronic hepatitis C. In this study we prospectively investigated the incidence of depression during IFN therapy in patients with chronic active hepatitis C. The psychiatric status of 85 patients (53 men, 32 women; mean age 49.1 years) with chronic active hepatitis C who began receiving IFN at Showa University Hospital was assessed before and 2, 4, 12 and 24 weeks after the start of IFN therapy, using the major depressive episode diagnostic criteria listed in the DSM-III-R and the Hamilton Depression Scale HDS). All of the patients provided informed consent prior to participation in this study. IFN therapy was discontinued in 5 cases (5.9%) because of physical side effects and in 4 cases (4.7%) because of depression. Two, 11, 14, 25 and 16 patients were diagnosed as having major depressive episodes before and 2, 4, 12 and 24 weeks after the start of IFN therapy, respectively. The number of patients who were asymptomatic before the start of IFN therapy but were diagnosed as having a major depressive episode at least once during IFN therapy was 31 (31/83 = 37.3%). The mean HDS scores at 2, 4, 12 and 24 weeks (5.4, 6.0, 8.8 and 6.6) were significantly higher than that before the start of IFN therapy (3.0). The patients whose first diagnosed major depressive episodes occurred more than 4 weeks after the start of IFN therapy tended to be more severely depressed than those in whom it occurred less than 4 weeks after the start of IFN therapy. Compared to the 47 patients who completed 24 weeks of IFN therapy without experiencing depression, the 31 patients who were diagnosed as experiencing major depressive episodes during IFN therapy had significantly higher neuroticism scores determined using the Eysenck Personality Questionnaire, showed a more severely depressed mood and experienced more severe sleep disturbances before the start of IFN therapy. The latter group of patients also tended to have comorbid chronic physical disorders such as hypertension or diabetes mellitus and the histories of mental disorders before the IFN therapy; however these differences were not statistically significant. There were no differences between the two groups in patient age or sex, the severity of hepatitis before the IFN therapy, the type of IFN used in the therapy or the efficacy of IFN in the treatment of the hepatitis C. Our results indicate that the decision as to whether to treat chronic active hepatitis C with IFN should be made carefully and that early intervention and careful monitoring of depression are required during IFN therapy in the treatment of chronic active hepatitis C.     

Formation mechanism of ZrSiO4 powders

The formation mechanism of ZrSiO₄ powders from ZrO₂ and colloidal SiO₂ sols has been studied. The change in the ZrSiO₄ yield rate with seeding and non-seeding has also been investigated. The induction period of the ZrSiO₄ yield-rate curve corresponded to the n=1 region, a simple nucleation region, on the Avrami plot. The n=1 region was a rather wide range at 1200–1300°C and the nucleation reaction was promoted in this temperature range. It was found that the ZrSiO₄ yield rate became high, even if seeding was not used, when the heating rate was controlled at less than 1 °C min^–1.     

Determination of optimal sending voltage profile in distribution systems with distributed generators

Sending voltage profile of distribution feeder is controlled by changing a tap of distribution transformer. In a distribution network with distributed generators, for reasons of effect of reversed flows from them and existence of a great number of sending voltage profile candidates, it is not easy to control sending voltage profile within the acceptable voltage limit. In this paper, in order to determine the optical sending voltage profile of distribution transformer in a distribution network with distributed generators, the authors propose a new method to determine the optimal sending voltage profile so as to minimize the total number of tap position's change per day under constraints of acceptable voltage limit. In the proposed method, after calculating acceptable range of three‐phase voltage of distribution feeder, the optimal profile of tap position within the calculated acceptable voltage range is determined among these candidates by using reduced ordered binary decision diagram (ROBDD) which is an efficient enumeration algorithm. In order to check the validity of the proposed method, numerical simulations are carried out for a distribution network model with a distributed generator. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(2): 16–24, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20393     

Effects of Particle Strength of Feedstock Powders on Properties of Warm-Sprayed WC-Co Coatings

Warm spray (WS) process, which can control the temperature of a combustion gas jet used to propel powder, has been successfully applied to deposit WC-Co coatings. Detrimental reactions resulting from dissolution of WC into Co binder and decarburization were suppressed effectively by keeping the WC-Co particles’ temperature below the m.p. of the binder phase. In this study, three nano-structured WC-12Co powders with different particle strengths were prepared by changing the sintering conditions of spray-dried powder and were deposited by WS. The deposition efficiency and porosity of the coatings decreased with increasing the particle strength. The coating deposited from the powder with very low particle strength showed significant phase changes, while those deposited from the higher particle strengths showed almost no change. Particle Image Velocimetry revealed significant disintegration of the weakest powder, which explains the changes observed. The hardness and wear properties of the former coating, therefore, were inferior to the other two.     

Recording characteristics of electroless-plated perpendicularrecording flexible disks with a perpendicular head

Perpendicular magnetic recording using a main-pole-driven perpendicular head was tested using electroless-plated flexible disks. Soft magnetic NiFeP films, also produced by electroless plating, were used as an underlayer of a perpendicular recording medium in this test. Two types of flexible double-layer media, composed of an electrodeless-plated CoNiReP film with two types of NiFeP underlayers with a coercivity of 2 and 5.5 Oe, were fabricated, and their recording characteristics were measured. A recording density value of 75 kFRPI was obtained for the medium with the softer magnetic 2-Oe underlayer, about twice as high a value as that for the medium with the 5.5-Oe underlayer     

Vertical seismic response of overhead crane

Vertical seismic response behavior is an important issue for the seismic design of equipments. The equipment, which is comparatively soft and unrestrained vertically, may resonate and its response is significantly magnified under vertical seismic excitation. Overhead crane is an example of equipment that is unrestrained vertically. The dynamic behavior of an 150-ton-capacity overhead crane under vertical seismic excitation was investigated by scale model excitation test and nonlinear time history analysis. The excitation tests were performed with several input levels and the vertical response with each input level was obtained. The simulation analysis approximately corresponded to the results of the excitation test.