Fish androgen receptor: cDNA cloning, steroid activation of transcription in transfected mammalian cells, and tissue mRNA levels

The mutant form of human apoA1, known as apoA1 Milano, is formed as a result of arginine 173 to cysteine substitution and inhibits experimental atherosclerosis in cholesterol-fed animals. This study was designed to determine if apoA1 Milano would modify arterial thrombogenesis. Sprague Dawley rats were intravenously administered the carrier alone (n=8) or apoA1 Milano (20 mg. kg-1. d-1 for 4 to 10 days, n=17). The abdominal cavity was opened, and the abdominal aorta was isolated. Whatman paper impregnated with 35% FeCl3 was wrapped around the surface of the aorta, and aortic flow was recorded continuously. In carrier-treated rats, an occlusive platelet-fibrin-rich thrombus was formed in 21.2+/-4.1 (mean+/-SD) minutes. Treatment of rats with apoA1 Milano markedly delayed time to thrombus formation (38.8+/-11.9 versus 21.2+/-4.1 minutes, P<0. 01), inhibited platelet aggregation (25+/-7% versus 50+/-11%, P<0. 01), and reduced weight of the thrombus (18.5+/-1.8 versus 23.7+/-2. 3 mg/cm, P<0.01). Total cholesterol and HDL levels remained similar in both groups of rats, but plasma apoA1 Milano levels were elevated in apoA1 Milano-treated rats. In in vitro studies, incubation of platelets with apoA1 Milano reduced ADP-induced platelet aggregation by about 50%, but apoA1 Milano had no direct effect on vasoreactivity. This study provides further evidence for critical role of platelets in thrombosis. Use of apoA1 Milano offers a novel approach to inhibit arterial thrombosis.     

Strongly secure ramp secret sharing schemes for general access structures

Ramp secret sharing (SS) schemes can be classified into strong ramp SS schemes and weak ramp SS schemes. The strong ramp SS schemes do not leak out any part of a secret explicitly even in the case that some information about the secret leaks out from some set of shares, and hence, they are more desirable than the weak ramp SS schemes. In this paper, it is shown that for any feasible general access structure, a strong ramp SS scheme can be constructed from a partially decryptable ramp SS scheme, which can be considered as a kind of SS scheme with plural secrets. As a byproduct, it is pointed out that threshold ramp SS schemes based on Shamir's polynomial interpolation method are not always strong.     

Effects of osteoblast-like cell seeding on the mechanical properties of porous composite scaffolds

In tissue engineering technology, polymer–ceramics or polymer–polymer composites have been considered as advanced scaffolds having mechanical stability, biocompatibility, cell proliferation, and easy processability. However, the relationship between the mechanical properties and the cell proliferation behavior of such composite scaffolds has not been clarified yet. In this study, two types of composite scaffolds, poly(ethylene terephthalate) (PET) fiber/collagen and β-tricalcium phosphate (β-TCP)/gelatin scaffolds, were investigated. MC3T3-E1 cells were cultured in these scaffolds under appropriate conditions. Compression tests were then periodically conducted to evaluate the compressive elastic modulus. It was found that the modulus of the scaffolds containing cells increased with the cell culture period. It is noted that the modulus of the β-TCP/gelatin with cells was approximately seven times larger than that of the PET fiber/collagen with cells.     

Analysis of hair follicle penetration of lidocaine and fluorescein isothiocyanate-dextran 4 kDa using hair follicle-plugging method

Objective: Skin appendages including hair follicles (hfs) and the stratum corneum (sc) are beginning to be recognized as important permeation pathways for the skin permeation of drugs, but their detailed role is not yet clear. To investigate the contribution of hfs to drug permeation, we conducted skin permeation tests by controlling the hf contribution with a hf-plugging method.

Method: Lidocaine (LC) and fluorescein isothiocyanate-dextran 4?kDa (FD-4) were selected as model drugs and pig ear skin was used as model skin.

Results: Skin permeabilities of ionized LC and FD-4 decreased with hf-plugging, whereas no change was observed for the skin permeation of unionized LC. A fairly good correlation was found for ionized LC and FD-4 between skin permeability and the number of hfs plugged. Permeation parameters of model drugs for both skin pathways were calculated utilizing Fick's second law of diffusion. Consequently, the sc pathway could highly contribute to the permeation of unionized LC, since unionized LC shows markedly high partition to the sc. In contrast, the hf pathway could contribute to the permeation of ionized LC and FD-4, since these had high distributions to the hf pathway in spite of its very small surface area relative to whole skin surface area.

Conclusion: The hf pathway must be important for the skin permeation of ionized compounds and hydrophilic high molecular compounds. hf-plugging is also a useful method for assessing the skin permeability of compounds through the hf pathway.     

The stability of voltage oscillation modes in longitudinal power systems with SVC

In this paper, we investigate the stability of voltage oscillation modes in longitudinal power systems equipped with static var compensators (SVC). These modes are usually stable, so they do not appear without external force. The conventional harmonic resonance is a phenomenon in which an oscillation mode is excited with a harmonic source. Hence, it is solved by removing the source with a harmonic filter. For this reason, an SVC is equipped with several filters. However, there is a possibility that an oscillation mode itself may become unstable. If a mode is unstable, it can have a large amplitude without any harmonic source. Since it needs no harmonic source, its frequency is not limited to a harmonic frequency, but can have any value. The harmonic instability in direct‐current transmission systems is an example of such phenomena. The PLL (phase‐locked loop) is considered to be effective to suppress harmonic instability with an SVC. However, no theoretical reason has been shown as yet. This paper clarifies the effectiveness of PLL based on a stability condition for the voltage oscillation modes. Frequency responses of a thyristor‐controlled reactor (TCR), a component of the SVC, are largely influenced by the presence of the PLL. If a PLL exists, the stability condition is always satisfied, and all modes are stable. Lastly, we perform numerical simulations to show the validity of our investigation. © 2001 Scripta Technica, Electr Eng Jpn, 137(2): 8–17, 2001     

Mutational analysis of the p73 gene localized at chromosome 1p36.3 in colorectal carcinomas

A case of chordoid meningioma occurring in a 15-year-old girl is presented. The patient manifested seizures as the initial symptom and subsequently exhibited subclinical microcytic hypochromic anemia. The tumor, located in the falcotentorial region and associated with diffuse edema, was totally resected. On histological examination of the surgical specimen, the clustering pattern of partly vacuolated cells in the mucoid stroma mimicked chordoma; however, positive staining of individual cells for vimentin and epithelial membrane antigen led to a diagnosis of meningioma. Interestingly, the tumor cells were surrounded by a periodic acid-Schiff- and type IV collagen-positive substance. Electron microscopy demonstrated a strikingly dense and thick basal lamina. The patient's microcytic hypochromic anemia disappeared after the tumor was removed. Both the clinical and pathological features of this case resemble those of chordoid meningioma, a rare meningioma variant.     

A flexible decision method for transmission system expansion planning considering power interruption cost

Under the current deregulation of the electric utility industry, power system planning has become more complex. System planners are required to study how to use available resources to meet customer's demand economically with acceptable reliability and quality. Integrated resource planning has emerged recently as one effective approach for this problem, and the approach has been expanded to include the value of reliability, that is, power interruption cost. This paper is aimed at developing a flexible decision method to select a favorable plan among various transmission system expansion alternatives, not only from a power supplier's viewpoint, but also from the customer's perspective, including cost of interruption. Bellman-Zadeh's maximizing decision using a fuzzy decision set is applied as a flexible decision method which is able to reflect the planner's intentions. Numerical examples are given to ascertain the effectiveness of the proposed method.