Discharge characteristics of steady-state high-density plasma source based on cascade arc discharge with hollow cathode.

We developed a steady-state high-density plasma source by applying a hollow cathode to a cascade arc discharge device. The hollow cathode is made of a thermionic material (LaB6) to facilitate plasma production inside it. The cascade arc discharge device with the hollow cathode produced a stationary plasma with an electron density of about 1016 cm-3. It was found that the plasma source produces a strong pressure gradient between the gas feed and the vacuum chamber. The plasma source separated the atmospheric pressure (100 kPa) and a vacuum (100 Pa) when the discharge was performed with an argon gas flow rate of 5.0 l/min and a discharge current of 40 A. An analysis of the pressure gradient along the plasma source showed that the pressure difference between the gas feed and the vacuum chamber can be well described by the Hagen-Poiseuille flow equation, indicating that the viscosity of the neutral gas is the dominant factor for producing this pressure gradient. A potential profile analysis suggested that the plasma was mainly heated within cylindrical channels whose inner diameter was 3 mm. This feature and the results of the pressure ratio analysis indicated that the temperature, and, thus, viscosity, of the neutral gas increased with the increasing number of intermediate electrodes. The discharge characteristics and shape of the hollow cathode are suitable for plasma window applications.

Pharmacology and toxicology of Bupleurum root-containing Kampo medicines in clinical use.

Kampo (Japanese traditional herbal) medicines have been produced by combining multiple crude drugs, almost all of plant origin but with some of animal or mineral origin, and contain a great many substances. Their effect is a combination of the various interactions of the constituent substances, whether they are enhancing, synergistic or suppressive. Kampo medicine has an overall effect that is different from the combined effects of individual crude drugs, and several side effects such as anorexia, slight fever and nausea have been reported in the treatment of certain disorders and disease states with Kampo medicines. Among 210 medical formulations used in Japan, some relevant information on the clinical uses, pharmacology and toxicology of six manufactured Kampo medical formulations, Shosaikoto, Daisaikoto, Saikokeishito, Hochuekkito, Saibokuto and Saireito, containing Bupleurum root are reviewed. Studies of some potential interactions between Kampo medicine and western drugs are also considered.

[Five cases of erythema infectiosum in adults].

The similarities between clinical features of erythema infectiosum and collagen disease or other viral infections prompted us to investigate clinical manifestations and laboratory data of parvovirus B19 (B19) infection in adults. We diagnosed all five patients as acute B19 infection by antibody assays. The age of patients ranged from 18 to 39 years old (mean 29), and all patients were female. All five patients showed high fever, arthralgia and edema of the extremities. Four of the five patients showed skin rash of the extremities or cheeks. Two patients were diagnosed as erythema infectiosum by family physicians before coming to us. The three remaining patients were suspected to be systemic lupus erythematosus, adult Still disease or rubella indivisually and referred to our hospital. A-27-old female (case 5) visited our hospital because of polyarthralgia and butterfly rash on her face. A test for antinuclear antibodies (ANA) was positive at a dilution of 1:320. Rheumatoid factor (RF) was also detected by latex fixation test. Her AST was 51 IU/L, ALT 68 IU/L and LDH 568 IU/L. Her symptoms persisted for 3 weeks and hepatic dysfunction recovered within 3 weeks. Five months later. ANA was negative at the dilution of less than 1:40. We suggest that the similarities between some symptoms of B19 infection and clinical and serological manifestation of collagen diseases merit closer attention.

[Longitudinal study of serological response to Bartonella henselae by indirect fluorescence assay in cat scratch disease].

Sequential serologic testing for IgG and IgM titers to Bartonella henselae were evaluated by an indirect fluorescence assay (IFA) in patients with CSD. The IFA test for the detection of IgG and IgM antibodies to B. henselae in 52 CSD patients showed that 40 (76.9%) were positive for IgG antibody and 9 (17.3%) were positive for IgM antibody. Two or more consecutive serum samples from 30 patients with CSD were assessed. In regard to the detection of IgG antibody, 5 patients had rapidly elevated titers in the acute phase, 12 patients had high titers from the acute phase, and 5 patients had a positive titer 24 weeks after the onset. B. henselae IgM antibody kinetics varied widely between patients with CSD. The seropositive rate for the antibody to B. henselae was analyzed at overtime after the onset and we found that the IgG-seropositive rate was high from 2 weeks after the onset and low after 25 weeks. The sensitivity of the IgM IFA was low, and IgM antibody to B. henslelae was not detected from 9 weeks. The detection from consecutive serum samples of antibodies to B. henselae by IFA is very useful for diagnosis in the case of clinically suspected CSD.

Identification and quantification of natural isoxazolinone compounds by capillary zone electrophoresis.

A capillary zone electrophoresis (CZE) method that is specific, simple, rapid and also cheap was developed to analyse some natural UV-absorbing isoxazolinone compounds with toxic potential present in legume seedlings. The six most common natural isoxazolinone compounds were separated within 10 min with 25 mM potassium phosphate (pH 7.5) containing 8% 1-propanol as running buffer. A 60 cm coated fused-silica capillary (52.6 cm effective length x 75 microm I.D.), with an electric field of 375 V/cm at 30 degrees C was used. The limit of detection ranged from 0.01 mM (3.0 microg/ml) to 0.03 mM (7.7 microg/ml). Linearity between peak areas and concentrations ranging from 0.05 mM to 1.75 mM were determined for each isoxazolinone. The correlation coefficient was 0.9954 or greater. Both relative migration time and peak area were reproducible. The RSD of relative migration time is between 0.44 and 1.94% and RSD of peak area is between 1.26 and 6.86%. The concentrations of isoxazolinones in Lathyrus odoratus and L. sativus seedlings obtained by CZE were in agreement with the previous results from HPLC.

Ardisiphenols A-C, novel antioxidants from the fruits of Ardisia colorata.

Novel alk(en)ylphenols, named ardisiphenols A--C (1--3) were isolated from the fruits of Ardisia colorata, together with known alk(en)ylresorcinols (4--6). Their structures were determined by the NMR and MS/MS analyses. All compounds showed scavenging activities towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and cytotoxicities against murine breast cancer cell line, FM3A.

[Evaluation of serological response to Bartonella henselae by enzyme immunoassay in cat scratch disease].

The IgG and IgM titers to Bartonella henselae were determined by an enzyme immunoassay (EIA). The EIA test for detection of IgG and IgM antibodies to B. henselae concerning CSD showed that 8 (40%) of 20 patients with CSD had a serum IgG antibody titer of 12 EIA unit or more and that 5 (25%) patients had a serum IgM titer of 12 EIA unit or more. Totally 12 (60%) of the 20 patients with CSD were seropositive for B. henselae. The mean age of IgG positive patients were higher than IgM positive patients. The IgM antibodies to B. henselae disappeared within 4 to 12 weeks after onset of disease. The IgG antibodies to B. henselae disappeared within 3 to 8 weeks after onset of the symptoms in 2 cases of CSD. Another 2 cases CSD produced high levels of IgG antibodies in the acute phase of the disease. Different course of IgG and IgM antibody titers were found in sera from patients.

Immunomodulatory constituents from three ascomycetes, Gelasinospora heterospora, G. multiforis, and G. longispora.

Three new 2-pyrones (2H-pyran-2-ones) called multiforisins G (3), H (1), and I (4), and a known hexaketide sordarial (2) have been isolated from an Ascomycete Gelasinospora heterospora. Among them, 1, 2, and 3 have been proved to be the immunosuppressive components of the fungus. Compounds 1, 3, and 4 have also been isolated from G. multiforis together with multiforisin A (5), which was formerly isolated from this fungus as its main immunosuppressive feature, and 1-5 have also been isolated from G. longispora. The absolute stereostructure of 2, which was not previously certain, has finally been determined to be (3'R,4'S). It has been found that the multiforisins 1, 3, and 5 in which one of the two substituents at positions 3 and 5 is a hydroxymethyl group and the other is a formyl or an acetoxymethyl group, show high immunosuppressive activity; the immunosuppressive activity of 3 does not seem to be due to inhibition of interleukin 2 (IL-2) production.

Distinctive portal venographic pattern in patients with sclerotherapy resistant oesophageal varices.

We performed prophylactic sclerotherapy in 350 patients with 'high risk' oesophageal varices (F2 or F3 with a moderate or severe red colour sign). Of these patients, eight exhibited sclerotherapy resistance (i.e. no significant reduction in the size of varices after five sessions of sclerotherapy). Thus, the prevalence of sclerotherapy resistant varices was 2%. Of 350 patients, 97 underwent haemodynamic investigation before sclerotherapy. This group consisted of seven patients with sclerotherapy resistant varices and 90 patients with non-resistant varices. Portal pressure, assessed by portal venous pressure gradient, was similar in these two groups (21.5 +/- 4.8 vs 19.8 +/- 5.0 mmHg, respectively; NS). However, the prevalence of the 'pipe-line' form of variceal feeding pattern (a large dilated left gastric vein running up the oesophagus) was higher in patients with resistant varices than in those with non-resistant varices (100 vs 3%, respectively; P < 0.01) and the diameter of the left gastric vein was larger in patients with resistant varices than in those with non-resistant varices (12.4 +/- 2.0 vs 7.8 +/- 2.3 mm, respectively; P < 0.01). Moreover, the extravariceal portosystemic shunt was poorly developed in patients with resistant varices compared with non-resistant varices (0 vs 52%, respectively; P < 0.05). We conclude that the pipe-line pattern, fed by a large left gastric vein and associated with poorly developed extravariceal portosystemic shunt, is a distinctive portal venographic feature of sclerotherapy resistant varices.

Gastric mucus generation in cirrhotic patients with portal hypertension. Effects of tetraprenylacetone.

We have evaluated gastric mucus generation (study 1) and the effects of tetraprenylacetone on gastric mucus generation (study 2) in cirrhotic patients with portal hypertension. Study 1: Included were 50 noncirrhotics (group A), 25 cirrhotics without portal hypertension (group B), and 25 cirrhotics with portal hypertension (group C). The antrum, corpus, and fundus mucus generation was assessed by hexosamine concentration using biopsy specimens. In groups A and B, the antrum hexosamine concentration was significantly higher compared with the corpus (P < 0.01, P < 0.01) and the fundus (P < 0.01). In contrast, the hexosamine concentration at each location was similar in group C. Furthermore, the antrum hexosamine concentration of group C was significantly lower compared with that of group A (P < 0.05). In study 2, a double-blind design, 300 mg of tetraprenylacetone was administered for four weeks in 10 cirrhotics with portal hypertension and placebo in 10. The regional hexosamine concentrations were measured before and after drug administration. Placebo administration did not change hexosamine concentration at each location. In contrast, tetraprenylacetone increased the antrum and corpus hexosamine concentration (P < 0.01, P < 0.05), although the fundus concentration did not change. These data suggest that cirrhotics with portal hypertension have reduced gastric antral mucus generation and tetraprenylacetone normalizes this.

Evaluation of patient outcome following sclerotherapy for esophageal varices.

After excluding terminally all patients, we evaluated a total of 718 patients treated with endoscopic injection sclerotherapy. They involved 350 episodes of acute hemorrhage and 368 prophylactic procedures in patients with risky varices. The 1-year cumulative survival rate was significantly lower in the acute hemorrhage group than in the prophylactic group (P < 0.05). The difference in survival between the two groups was primarily due to the number of deaths in the first 2 months after sclerotherapy (20.1% vs 0.8%, P < 0.0005). Improvements in the sclerotherapy technique significantly reduced the number of deaths from bleeding (9.3% vs 3.4%, P < 0.05), but not those from liver failure following variceal hemorrhage. Prophylactic EIS is advantageous in the treatment of esophageal varices, i.e. it may prevent deaths from liver failure attributed to variceal hemorrhages. The present study shows that preliminary prevention of variceal hemorrhage provides favorable hemostatic efficacy in patients with risky varices.

Vasopressin plus oxygen vs vasopressin alone in cirrhotic patients with portal-hypertensive gastropathy: effects on gastric mucosal haemodynamics and oxygenation.

The effects of vasopressin plus oxygen and vasopressin alone on gastric mucosal perfusion and oxygenation were studied using reflectance spectrophotometry and laser Doppler velocimetry in 23 cirrhotic patients with portal-hypertensive gastropathy. The measurements were performed under basal conditions and after double-blinded administration of placebo (n = 7), vasopressin (0.3 U/min; n = 8) or vasopressin (0.3 U/min) plus nasal oxygen (4 L/min; n = 8). No significant effects on gastric mucosal haemodynamics and oxygenation were observed after placebo. In contrast, vasopressin and vasopressin plus oxygen induced a similar reduction in haemoglobin content (-26 +/- 2 and -21 +/- 4%, respectively P < 0.01), and laser Doppler signal (-23 +/- 2 and -22 +/- 2%, respectively, P < 0.01). Although each treatment induced a significant reduction in oxygen saturation (-21 +/- 2 and -7 +/- 1%, respectively P < 0.01), the effect was less pronounced in patients receiving the combination than in those receiving vasopressin alone (P < 0.01). These data suggest that vasopressin and vasopressin plus oxygen reduce gastric mucosal hyperaemia and that the oxygen supplement partially protects against gastric mucosal hypoxia during vasopressin infusion in cirrhotic patients with portal-hypertensive gastropathy.

Echo-Doppler measurements of portal vein and superior mesenteric artery blood flow in humans: inter- and intra-observer short-term reproducibility.

The reproducibility of echo-Doppler measurements of portal vein and superior mesenteric artery blood flow has not been extensively studied. In the present study, two groups of subjects were examined to test inter- and intra-observer reproducibility. Each study population consisted of 15 nonportal hypertensive and 15 portal hypertensive subjects. With a standardized technique, the crosssectional area and velocity of blood flow in the portal vein and superior mesenteric artery were recorded in triplicate by skilled operators. The flow volume of each vessel was calculated by multiplying the cross-sectional area by the velocity of blood flow. The measurements were performed in a blind fashion over a 60 min period. The reproducibility of measurements was assessed by calculation of intraclass correlation coefficients and coefficients of variation. The intra-observer intraclass correlation coefficient was 0.77 for portal vein blood flow and 0.84 for superior mesenteric artery blood flow, suggesting good reproducibility. The intra-observer coefficient of variation was 11 and 9%, respectively. In contrast, the interobserver intraclass correlation coefficient was calculated to be 0.49 for portal blood vein blood flow and 0.57 for superior mesenteric artery blood flow, indicating fair reproducibility. In addition, the interobserver coefficients of variation were calculated to be 20 and 18%, respectively. These data suggest that intra-observer reproducibility in echo-Doppler measurements of portal vein and superior mesenteric artery blood flow is acceptable but inter-observer reproducibility is not. Examination by a single operator, rather than multiple operators, is therefore advisable. Even when measurements are performed by a single investigator an approximate variance of 10% in the measurement in a single subject should be expected.

Serological study of Bartonella henselae in cat scratch disease in Japan.

It has become clear that Bartonella henselae is a common cause of cat scratch disease (CSD). The indirect fluorescence antibody (IFA) test for detection of IgG and IgM antibodies to B. henselae concerning CSD showed that 5 (50%) of 10 patients with CSD had a serum IgG antibody titer of 1:128 or more and that 2 (20%) patients had a serum IgM antibody titer of 1:20 or more. One of 7 asymptomatic members of patients' families (14%) had IgG antibody to B. henselae at a titer of 1:256. IgM antibody to B. henselae was not detected in sera from the patients' families. Both IgG and IgM antibodies to B. henselae were not detected in sera from the healthy control group. These data suggest that B. henselae may be a cause of CSD in Japan.

Supplemental oxygen during endoscopic variceal ligation: effects on arterial oxygenation and cardiac arrhythmia.

OBJECTIVES: Endoscopic variceal ligation may affect cardiopulmonary function. The aim of this study was to determine the effect of either nasal oxygen (2 L/min) or no oxygen on arterial oxygenation and cardiac arrhythmia during variceal ligation. METHODS: A prospective, endoscopy team-blinded, randomized, cross-over study (first session vs second session) was conducted in 30 cirrhotic patients undergoing variceal ligation. Oxygen saturation (SaO2) and cardiac arrhythmia were assessed by a pulse oximeter. In this study, 15 patients received supplemental oxygen in the first sessions, and 15 received oxygen in the second sessions. RESULTS: Oxygen desaturation (nadir SaO2 < 90%) occurred in 23% of patients breathing room air but was prevented by oxygen (p < 0.01), and the nadir SaO2 was significantly lower in patients breathing room air than in those receiving oxygen (93.2 +/- 0.7% vs 98.3 +/- 0.3%, p < 0.01). During the procedure, premature ventricular contraction was more frequently observed in patients breathing room air than in those receiving oxygen (14.0 +/- 3.2/h vs 5.4 +/- 1.5/r, p < 0.05). CONCLUSIONS: These data suggest that oxygen desaturation and cardiac arrhythmia are common in patients undergoing variceal ligation and that low flow nasal oxygen can alleviate these events. Supplemental oxygen is therefore advisable to avoid potential serious cardiopulmonary accidents in patients undergoing variceal ligation.

Ethanolamine oleate versus butyl cyanoacrylate for bleeding gastric varices: a nonrandomized study.

BACKGROUND AND STUDY AIMS: Sclerotherapy may be useful in patients with bleeding gastric varices. The aim of this study was to compare the effects of two sclerosants in these patients. PATIENTS AND METHODS: In a prospective nonrandomized trial, we performed single sclerotherapy for bleeding gastric varices using ethanolamine oleate (n = 24) or butyl cyanoacrylate (n = 29). The patients were followed for a mean of 14 months. RESULTS: The rate of initial hemostasis (no bleeding occurred for 48 hours after sclerotherapy) was significantly higher in the butyl cyanoacrylate group (93%) than in the ethanolamine oleate group (67%) (p = 0.014). The rate of initial hemostasis in cardiac variceal bleeding did not differ significantly between the ethanolamine oleate and butyl cyanoacrylate groups (83% vs. 100%, p = 0.140). In contrast, the hemostasis rate for fundal variceal bleeding was significantly higher in the butyl cyanoacrylate group than in the ethanolamine oleate group (88% vs. 50%, p = 0.023). Although the rebleeding rate did not differ between the two groups (30% vs. 25%, p = 0.921), the mortality rate was significantly higher in the ethanolamine oleate group (67% vs. 38%, p = 0.043). In addition, the incidence of complications in the butyl cyanoacrylate group was similar to that in the ethanolamine oleate group (46% vs. 41%, p = 0.745). CONCLUSIONS: These results suggest that initial control of fundal varices is more difficult than it is with cardiac varices, but butyl cyanoacrylate is superior to ethanolamine oleate, and the survival advantage from butyl cyanoacrylate seems to be partially related to the increased early bleeding deaths in the ethanolamine oleate group.

Effects of exercise-induced sympathoadrenergic activation on portal blood flow.

We examined the relationship between portal venous blood flow and sympathoadrenergic activation after muscle exercise. For this purpose, we used echo Doppler and measured plasma noradrenaline concentration before and after mild (7 metabolic units, N = 8) and maximal exercise (14 metabolic units, N = 8) in 16 patients without significant disease. Portal venous flow did not change after mild exercise. In contrast, a significant reduction in portal venous flow was observed after maximal exercise (P < 0.01). This was due to reductions in both cross-sectional area of the portal vein (P < 0.01) and portal venous velocity (P < 0.01). Overall, there were significant inverse relationships between the change in plasma noradrenaline concentration and that in cross-sectional area of the portal vein [r = -0.44, P < 0.01 (absolute change); r = -0.47, P < 0.01 (relative change)], that in portal venous velocity (r = -0.63, P < 0.01; r = -0.61, P < 0.01), and that in portal venous flow (r = -0.54, P < 0.01; r = -0.59, P < 0.01). These results suggest that the reduction in portal venous flow after exercise is related to the degree of sympathoadrenergic activation. This reduction may be due mainly to splanchnic vasoconstriction.

Wedged hepatic venous pressure reflects portal venous pressure during vasoactive drug administration in nonalcoholic cirrhosis.

Hepatic venous catheterization is widely used to assess portal pressure. However, it remains unclear whether wedged hepatic venous pressure is a close indicator of portal venous pressure during vasoactive drug administration in nonalcoholic cirrhosis. To address this issue, we analyzed the data from our previous published studies. Forty patients with nonalcoholic cirrhosis (HBV infection in five, HCV infection in 28, and cryptogenic in seven) were available in this analysis. A vasoconstrictor (N = 14), vasodilator (N = 10), or combination (N = 16) was administered. The agreement of the changes between portal and wedged hepatic venous pressures during pharmacological manipulation was assessed by an intraclass correlation coefficient. The intraclass correlation coefficient in each subgroup was more than 0.60 (0.62 in vasoconstrictor group, 0.87 in vasodilator group, and 0.73 in combination group). When the analysis was performed according to the cause of liver disease, the values were 0.67 in HBV infection, 0.73 in HCV infection, and 0.74 in cryptogenic cirrhosis. These results suggest that wedged hepatic venous pressure reflects portal venous pressure during vasoactive drug administration in patients with nonalcoholic cirrhosis.

Portal pressure after prophylactic sclerotherapy in patients with high-risk varices.

Portal hemodynamics and transhepatic portal venographic findings were studied before and after prophylactic sclerotherapy (mean duration = 40 +/- 14 days) in 16 patients with high-risk esophageal varices. Portal pressure, evaluated by the portal venous pressure gradient, increased by a mean of 21% in eight patients (50%) and decreased by a mean of 20% in eight patients (50%) with no statistically significant change overall. The two groups were further analyzed separately to identify the mechanism of the change in portal pressure. Intrahepatic vascular resistance did not change significantly in either group. However, the prevalence of extravariceal portosystemic shunts was greater in patients with decreased portal pressure than in those with increased portal pressure (88% vs. 25%, p < 0.05). Further, the enlargement of extravariceal portosystemic shunts was more marked in patients with decreased portal pressure than in those with increased portal pressure (88% vs. 0%, p < 0.01). In addition, liver function, assessed by intrinsic clearance, was not modified in the two groups. We conclude that prophylactic sclerotherapy increases or decreases portal pressure without modifying liver function. Although the mechanism of these portal pressure changes is not clear, intrahepatic vascular resistance does not play an important role and the presence of extravariceal portosystemic shunts may prevent further increases in portal pressure.