Extremely small-diameter, high-density, radio frequency, plasma sources and central gas feeding for next-generation electrodeless plasma thrusters.

Radio frequency (RF) waves including helicon waves can readily produce high-electron-density (ne up to 1013 cm-3) plasmas with a broad range of external operating parameters. Various featured RF and helicon sources in a wide range of scales are suitable for plasma propulsion schemes. Electrodeless RF plasmas have no direct contact between electrodes and antennas, which enables long-life operation. However, one of the crucial problems is to reduce the plasma size for future applications in nano- and pico-satellites. Diagnostics of the plasma parameters in a small area should also be improved. Furthermore, to increase plasma performance, it is important to consider the radial electron density (ne) profile with an increasing upper limit, observed in high-density helicon sources due to the depletion of neutrals. This problem may be controlled by the location of neutral gas feeding and knowledge of the gas pressure distribution. Here, production of RF plasmas, with extremely small diameters from 3-mm down to 0.5-mm including 1-mm, was demonstrated, and characterization of ne and the electron temperature was performed with a collisional radiative model. Finally, to improve plasma performance such as ne and the thrust force, internal gas feeding was demonstrated using a developed Pirani gauge to measure neutral density.

Extraction of heavy metals from MSW incinerator fly ash using saponins.

An extraction process with saponins was evaluated for removing heavy metals from MSW (municipal solid waste) incinerator fly ashes. Two different fly ashes, A and B, were treated on a laboratory scale with three triterpene-glycoside type of saponins, M, Q, and T, in the pH range 4-9. The results were compared with those of the HCI and EDTA treatment. The treatment with saponins extracted 20-45% of Cr from the fly ashes. Saponins were also effective in extracting Cu from fly ash A attaining 50-60% extraction. Saponin T extracted 100% of Pb from fly ash A at pH around 4. The extraction of Zn with the saponin treatment was similar to that of the HCl treatment. Further, Cr, Cu, Pb, and Zn were fractionated by sequential extraction to investigate the effect of saponins on each fraction. Extraction behavior of other elements during the saponin treatment was also studied. The leaching test on the residues received after the saponin treatment showed that the fly ashes were successfully detoxified to meet the landfilling guideline.

A decrease in the amount and function of inhibitory GTP-binding protein in the resistance small artery from spontaneously hypertensive rats.

The inhibitory GTP-binding protein (Gi protein) plays an important role in regulation of vascular tone. Many studies have implicated the role of Gi protein in conduit vessels. However, the physiological role of Gi protein in the control of peripheral microvascular tone in hypertension has not been established yet. Therefore, we investigated the concentration of Gi protein in the peripheral resistance arteries and aorta in the spontaneously hypertensive rats (SHR), normotensive Wistar-Kyoto rats (WKY) and renovascular hypertensive rats (RHR), using immunohistochemical methods semiquantitatively. Changes in the function of Gi protein in relation to alpha2-adrenoceptor were also investigated by microcannulation techniques. We have shown that the amount of alpha2 subunits of Gi protein in the cremaster small artery was significantly lower in SHR aged 4 weeks and older than in age-matched WKY and that there were no significant differences between RHR and WKY. We also demonstrated that the function of Gi protein in relation to alpha2-adrenoceptor was already lower in SHR before the onset of hypertension. The quantitative and functional decline in Gi protein in the smooth muscle cells of peripheral small arteries were observed in SHR even before the onset of hypertension, whereas rats with secondary hypertension did not exhibit this finding.

Tuning micelles of a bioactive heptapeptide biosurfactant via extrinsically induced conformational transition of surfactin assembly.

We have studied the effects of extrinsic environmental conditions on the conformation of surfactin, a heptapeptide biosurfactant from Bacillus subtilis, in aqueous solutions. It has been made clear that temperature, pH, Ca2+ ions and the synthetic nonionic surfactant hepta-ethylene glycol (C12E7) affect the conformation of surfactin in aqueous solutions. The beta-sheet formation reached a maximum at 40 degrees C both in presence and absence of (C12E7) and the nonionic surfactant enhances the beta-sheet formation even at 25 degrees C. Ca2 + induced the formation of alpha-helices and caused this transition at 0.3 mM with surfactin monomers or at 0.5 mM with surfactin micelles, but above these transition concentrations of Ca2+ beta-sheets were observed. In micellar solution the beta-sheet structure was stabilized at pH values below 7 or upon addition of Ca2+ in concentrations above 0.5 mM. Our results indicated that the bioactive conformation of surfactin is most likely the beta-sheets when the molecules are assembled in micelles. The beta-sheet structure in micelles could be retained by tuning the micelles. Surfactin micelles could be tuned in the bioactive conformation by manipulating pH, temperature, Ca2+ or (C12E7) concentrations in surfactin solutions. Our results strongly indicated that Ca2+ and other molecules (such as C12E7) may function as directing templates in the assembly and conformation of surfactin in micelles. Thus, we suggest environmental manipulation and template-aided micellation (TAM) as a new approach for preparing predesigned micelles, microemulsions or micro-spheres for specific application purposes.

Interferon induces insulin resistance in patients with chronic active hepatitis C.

AIM/METHODS: To elucidate the metabolic effect of interferon alpha, the following tests were performed on 14 patients with chronic active hepatitis C before and after interferon therapy (6 million units/day for 2 weeks): (1) oral glucose tolerance tests to measure insulin secretion; (2) euglycemic hyperinsulinemic clamp with oral glucose load to measure peripheral and hepatic insulin sensitivity (splanchnic glucose uptake); and (3) measurements of plasma levels of glucoregulatory hormones. RESULTS: The oral glucose tolerance test showed that a 2-week treatment with interferon did not induce apparent change in plasma glucose and insulin profiles. Nevertheless, interferon therapy worsened insulin-mediated glucose uptake in the peripheral tissues by 17% from 44.4+/-3.2 to 37.3+/-3.0 micromol x kg(-1) x min(-1) (p<0.05). Furthermore, interferon therapy significantly decreased splanchnic glucose uptake by 38% from 47+/-2% to 29+/-3% (p<0.01). No changes were noted for plasma glucoregulatory hormones, such as epinephrine, norepinephrine, cortisol and growth hormone, after interferon therapy. CONCLUSIONS: These results indicate that interferon therapy for 2 weeks induces insulin resistance in the splanchnic, as well as peripheral tissues, in patients with chronic active hepatitis C. Therefore, more careful observation may be needed during interferon therapy in subjects with impaired glucose tolerance.

Three extracellular chitinases in suspension-cultured rice cells elicited by N-acetylchitooligosaccharides.

In rice suspension culture, a large part (about 90% of total activity in the culture) of the chitinase activity was found in the medium. Two extracellular chitinases (which we named RCH-A and -B) were separated from the cell suspension by DEAE-cellulofine column chromatography. When cells were treated with N-acetylchitooligosaccharides (chitin oligosaccharides) for 3 days, extracellular chitinase activity increased about 3-fold over the control culture. After the treatment, another extracellular chitinase (named RCH-C) appeared in addition to increases in the levels of RCH-A and -B. Partial amino acid sequences of these enzymes indicated that RCH-A (33.5 kDa) and -B (34 kDa) were class Ib chitinases but RCH-C (27 kDa) was a class III chitinase. RCH-A and -B were capable of actively degrading water-insoluble chitin with high affinities, while RCH-C had less affinity for the substrate. However, when a water-soluble chitin derivative, 6-O-hydroxyethylchitin (glycolchitin) was used, RCH-C as well as RCH-A and -B degraded actively with a high affinity. A synergistic effect was observed when these three chitinases acted simultaneously in the hydrolysis of chitin.

[Epidemiological study of osteoporosis].

An epidemiological investigation of osteoporosis was carried out in a community in which fishing is the primary industry, and correlations were investigated between the bone mass and various risk factors for osteoporosis and biochemical findings. In 852, who could be examined directly, of the 3541 males and females aged 40 years or above living in Nansei Town, Watarai District, Mie Prefecture, the age, sex, height, body weight, years after menopause, married or unmarried, area of residence, daily activity, and intakes of milk, fish, and alcohol were studied by direct oral inquiry, and the serum calcium, inorganic phosphorus, alkaline phosphatase, and total protein were measured. The subjects were divided into a decreased bone mass group who showed grade I or more advanced loss in bone mass and a normal bone mass group who showed no or only slight loss in bone mass on the basis of microdensitometry (MD). Eighty-two subjects (9.6%) were classified as the decreased bone mass group. Items that showed a close correlation with sigma GS/D, which is an index of bone density, were age, years after menopause, serum alkaline phosphatase level, height, and body weight in females, age and serum alkaline phosphatase level in males. In the decreased bone mass group, 79 of the 82 subjects were females. Significant differences were observed between the decreased bone mass group and the normal bone mass group in age, years after menopause, serum alkaline phosphatase level, height, and body weight. From these results, a high age, being a female, low height, and a low body weight were found to be factors correlated with osteoporosis. Also, the bone mass was correlated with the serum alkaline phosphatase level and years after menopause.

Gastric mucosal cell proliferation and TGF alpha in the healing of peptic ulcers in human subjects.

We investigated the role of gastric mucosal proliferation and mucosal transforming growth factor-alpha (TGF alpha) in the healing of peptic ulcers in human subjects. During endoscopic observation, mucosal biopsy specimens were taken from the ulcer margin for flow cytometric analysis of the mucosal cell cycle and ELISA for mucosal TGF alpha content. Immunohistochemistry confirmed that biopsy specimens contained proliferating gastric epithelial cells, TGF alpha, and the TGF alpha receptor. When the stage of ulcer healing was categorized according to Sakita and Miwa, mucosal cell proliferation was less at active stages and gradually increased during the healing process. The mucosal TGF alpha level at the ulcer margin was not detectable at the A1 stage but increased to within the normal range during ulcer healing. After re-establishment of the epithelial layer at the site of the ulcer, cell proliferation returned to normal and TGF alpha remained within the normal range. Immunohistochemistry showed coexistence of TGF alpha and its receptor within PCNA-positive proliferating cells. These results suggest that TGF alpha and its receptor play an important role in gastric epithelial cell replication. The increase in TGF alpha at the ulcer margin might indicate a role in stimulation of gastric cell replication during ulcer healing.

[Glucose intolerance during interferon therapy in patients with chronic hepatitis type C].

A new side effect of interferon (IFN) therapy, glucose intolerance was investigated using insulin-clamp study. In 75 g oral glucose tolerance tests before and after the IFN therapy showed no significant difference, whereas clamp study showed a significant decrease of glucose disposal. Our data suggested that insulin resistance was the main reason for glucose intolerance observed during INF therapy in the patients with chronic active hepatitis C. Early detection and strict control of glucose intolerance could avoid the progress of glucose intolerance.

Clinical applications of ICG Finger Monitor in patients with liver disease.

The indocyanine green (ICG) Finger Monitor system is a non-invasive indication of ICG concentrations in the blood. In this study, significant correlation was found between the sensor signal voltage and plasma ICG concentrations ranging from 0.04 mg/dl to 1.0 mg/dl (r = 0.998, P < 0.001) in vivo. The ICG clearance curve showed an initial sharp rise 20-30 s after bolus injection, followed by a small rise. The concentration then deceased exponentially. In 196 patients with chronic liver disease, there was a close correlation between the KICG (plasma disappearance rate) and R15 (blood retention ratio at 15 min) (r = 0.886, P < 0.001, r = 0.912, P < 0.001) and corresponding values calculated by the conventional ICG method. In 263 cases with chronic liver disease, the plasma disappearance rates calculated using this monitor (mean +/- S.D.) were 0.156 +/- 0.064 (n = 20) in the control group, 0.129 +/- 0.060 (n = 92) in the chronic hepatitis group, 0.048 +/- 0.025 (n = 59) in the cirrhosis group and 0.059 +/- 0.03, (n = 92) in the group with hepatocellular carcinoma. A significant difference in the plasma disappearance rate and blood retention ratios 15 min after injection of ICG using this system was observed between control cases and the chronic hepatitis and cirrhosis groups (P < 0.0001). In 36 cases, the time from injection to the appearance of ICG in the fingertip significantly decreased in the cirrhosis group (P < 0.01). The ICG Finger Monitor system was shown to be useful clinically as well as for research due to its accuracy and non-invasive nature.

[A study of osteopenia in liver cirrhosis by dual energy X-ray absorptiometry (DXA)].

We studied osteopenia in patients with liver cirrhosis by dual energy X-ray absorptiometry (DXA). Total body bone mineral density showed a positive correlation with the lumbar spine bone mineral density, and % age matched total body bone mineral density under 90% was defined as osteopenia. The incidence of osteopenia in 54 patients with liver cirrhosis was 20.4%. Since this osteopenia had no relationship to the general risk factors for osteoporosis, it was suggested that it is a complication specific to liver cirrhosis. Because the level of serum total bilirubin and the activity of serum total alkaline phosphatase in the group with osteopenia were usually higher than those in the group without osteopenia, it was suggested that osteopenia in liver cirrhosis might be related to hepatic dysfunction.

Computer-assisted two-dimensional analysis of gastric mucosal hemoglobin distribution using electronic endoscopy.

An electronic endoscope was modified to assess the imaging of two-dimensional distribution of gastrointestinal mucosal hemoglobin with the aid of a computer and image analyzing system. The band-pass filters ranging from 530-470 nm (G'), and 770-830 nm (IR) replaced ordinary filters in a conventional electronic endoscope (Olympus V-10 or EVIS-200). As the hemoglobin is the most abundant biological pigment in the gastrointestinal mucosa absorbing the green light with little absorption in the infrared region, we used the algorithm of 32 [log2(Vir/Vg)] as a reflection of hemoglobin content in the surface mucosa. The algorithm had a good correlation with the spectrophotometrically measured hemoglobin concentration. The mucosal distribution of hemoglobin was displayed in patients with gastric ulcer. In conclusion, the computer and image analyzing system were successfully applied in an attempt to determine gastric mucosal hemoglobin content and its distribution. The possible applications of computers in endoscopic image analysis are discussed.

Effect of intravascular ethanol on modulation of gastric mucosal integrity: possible role of endothelin-1.

The influences of intravascular ethanol on gastric mucosal integrity and its relation to gastric circulation were investigated in rats. Ulcer formation of the gastric mucosa correlated with the blood ethanol concentration in the presence of 150 mM HCl in the rat stomach. Furthermore, the gastric mucosal hemoglobin concentration (IHb) and hemoglobin oxygen saturation (ISO2), estimated using organ reflectance spectrophotometry, decreased in a concentration-dependent manner with blood ethanol. In isolated, vascularly perfused rabbit stomach, various concentrations (10-400 mM) of ethanol infused into the celiac artery increased the perfusion pressure and released endothelin-1 (ET-1) from the gastric vasculature in a concentration-dependent manner. Moreover, a significant correlation existed between changes in the perfusion pressure and ET-1 concentration in effluents from the gastric vasculature. Furthermore, anti-ET-1 antibody reduced 100 mM ethanol-induced vasoconstriction in a concentration-dependent manner. The results indicate that intravascular ethanol increases the susceptibility of gastric mucosa to injury induced by intraluminal HCl by causing gastric vasoconstriction mediated by ET-1. Thus intravascular ethanol may play an important role in the mechanism of ethanol-induced gastric mucosal injury.

Effect of ethanol on endothelin-1 release from gastric vasculature.

The effects of ethanol on gastric vasculature in isolated vascularly perfused rabbit stomach was investigated. The isolated stomach was perfused with Krebs-Henseleit solution containing 3% dextran bubbled with 95% O2 and 5% CO2 at a rate of 12 ml/min. After mixture and perfusion of 10 mM to 400 mM of ethanol, perfusion pressure and endothelin-1 concentration in effluent from gastric vasculature were measured. Perfusion pressure and endothelin-1 concentration in effluent increased in a dose-dependent manner with increasing ethanol concentrations. In conclusion, the data suggest that ethanol may stimulate the release of endothelin from gastric vasculature and may cause gastric ischemia due to vasoconstriction resulting in acute gastric mucosal injury.

Penetration enhancement across a model membrane by liposomally entrapped drugs using N,N'-diacylcystine as a bilayer lipid.

A liposomal system for percutaneous absorption and transdermal drug delivery was developed and evaluated using a model apparatus connecting two chambers by a membrane. When N,N'-long chain diacyl L-cystine was incorporated into the liposomal bilayer as well as lecithin and cholesterol, liposomally entrapped calcein as the model drug transferred well across the keratin membrane functioning as the skin model.

[Intracellular calcium level, lipid peroxidation, and development of gastric mucosal injury in rat hemorrhagic shock].

Although acute gastric mucosal lesions (AGMLs) develop after the mucosal ischemia and reperfusion, precise intracellular mechanism for the development of AGMLs remains unclear. In the present paper, we investigated intracellular calcium level, lipid peroxidation, and gastric mucosal lesion in rat hemorrhagic shock model. We estimated intracellular calcium by measuring phosphorylase a activity in the gastric mucosa. The mucosal phosphorylase a increased during hemorrhagic shock, while it returned to be normal after the reinfusion of shed blood. Although mucosal lipid peroxide and area of AGMLs did not increase significantly during hemorrhagic shock, they increased significantly after the reinfusion. Diltiazem, a calcium antagonist, prohibited both of the increase in mucosal phosphorylase a activity during hemorrhagic shock and the increase in lipid peroxide content and area of AGMLs after the reinfusion of the shed blood. Organ reflectance spectrophotometry revealed that the gastric corpus suffered mucosal ischemia and hypoxia during the hemorrhagic shock. The are of AGMLs had a good correlation with a level of lipid peroxidation in the gastric mucosa. These results suggest 1) that intracellular free calcium in gastric mucosa increases during the mucosal ischemia; 2) that a calcium antagonist prohibits the increased intracellular free calcium during mucosal ischemia; and 3) that a calcium antagonist prohibits the increased mucosal lipid peroxide and the development of AGMLs after the mucosal reperfusion. Thus it is concluded that the increased intracellular free calcium during ischemia plays a key role in the mucosal tissue injury in the ischemia-reperfusion state.

Role of blood ethanol on gastric mucosal injury and gastric hemodynamics.

The present series of studies were performed to test the hypothesis that ethanol in the blood may play a role in the pathogenesis of gastric mucosal injury. Another hypothesis to be examined was that endothelin may be involved in ethanol-induced gastric mucosal injury. Elevated levels of blood ethanol induced by intraperitoneal infusion of ethanol increased vulnerability of the stomach to hydrochloric acid in a dose-dependent manner in rats. This may be due to impaired gastric mucosal hemodynamics and oxygenation as demonstrated by the results obtained by organ reflectance spectrophotometry (decreases in indices of mucosal hemoglobin contents and hemoglobin oxygen saturation). Ethanol infusion caused a dose-dependent increase in gastric vascular resistance in perfused rabbit stomach, which was accompanied by an increased production of endothelin-1. The results suggest that endothelin may be involved in the pathogenesis of ethanol-induced gastric mucosal injury.

[Development and clinical application of ICG clearance meter].

We have developed a finger-piece method that can indicates an accurate concentration of ICG based on the two wavelength spectrophotometry. Seventy-eight subjects were evaluated by this new method. The ICG clearance curve obtained from ICG clearance meter showed a rapid increase 20 or 40 seconds after the bolus injection. The curve decreased gradually, and increased again at 60 or 70 seconds. Plasma disappearance rate (PDR) by this method (XK ICG) was calculated by the at least square method from 600 data obtained from 5 to 15 minutes after the injection. There was a significant correlation between conventional PDR (KICG) and new method (XK ICG) also. We assume that this method have a possibility to discover new aspect of pharmacokinetics of ICG.

A study of chemoreception based on membrane fluidity and circular dichroism of a membrane assembly model--role of protein penetrating into the lipid bilayer.

We attempted to reconstitute a chemical sensing assembly by mimicking the natural constituents of cell membranes. This liposomal arrangement is able to recognize chemical stimulants by detecting perturbation of the ordered lipid bilayer due to penetration by protein molecules. It was ascertained by measuring membrane fluidity using ESR that this assembly may be able to detect individually added chemical stimulants such as short-chain-bearing odorants (isovaleric acid, isovaleraldehyde, and isoamyl alcohol etc) at a concentration of 3 x 10(-4) parts to 1 part water. This recognition mechanism may clarify both the affinity of chemical stimulants for the liposomal arrangement and the trigger action of conformational changes in poly-L-lysine (PLL) due to the penetration of the bilayer of the PLL and sodium octylsulfate complex.