Significance of soil moisture on temperature dependence of Hg emission.

Soil moisture is a key factor for mercury (Hg) emission from soil. Despite its significance for Hg emissions, the effect of soil moisture on Hg flux and fractions has not been thoroughly investigated. The objective of this study was to elucidate the influences of soil moisture and temperature on Hg fluxes from soils and Hg fractions. A kinetic study was performed to measure Hg emission fluxes of six soil samples under different temperature (T) (15 °C, 20 °C, 25 °C, 30 °C, and 35 °C) and moisture conditions (0%, 10%, and 20% added water). The results showed that the Hg fluxes increased with increases in T and soil moisture. A linear correlation was found between ln (Hg emission flux) and 1/T for the six soil samples at different moisture contents (R2 = 0.73-0.99). The range of activation energy (Ea) values was 25.31-57.86 kJ/mol. The Hg fractions in soils of different moisture content were determined by a sequential extraction method. The results demonstrated that soil moisture affected the Hg fractions in soils. The Ea values had different relationships with soil moisture in different soils. There were correlations between Ea and the elemental and mercuric sulfide fractions for air-dried soils. However, for moist soils, Ea was negatively correlated with the water-soluble and acid-soluble fractions. Collectively, the combination of the Hg emission kinetics and Hg fraction measurement of different moist soils indicated that Hg emission was affected by both total Hg concentration and Hg fractions.

Effects of N loading rate on CH4 and N2O emissions during cultivation and fallow periods from forage rice fields fertilized with liquid cattle waste.

The use of liquid cattle waste (LCW) as a fertilizer for forage rice is important for material recycling because it can promote biomass production, and reduce the use of chemical fertilizer. Meanwhile, increase in emission of greenhouse gases (GHGs), especially CH4 and N2O would be concerned. We conducted a field study to determine the optimum loading rate of LCW as N to promote forage rice growth with lower GHG emissions. The LCW was applied to forage rice fields, N100, N250, N500, and N750, at four different N loading rates of 107, 258, 522, and 786 kg N ha(-1), respectively, including 50 kg N ha(-1) of basal chemical fertilizer. The above-ground biomass yields increased 14.6-18.5 t ha(-1) with increases in N loading rates. During the cultivation period, both the CH4 and N2O fluxes increased with increases in LCW loading rates. In the treatments of N100, N250, N500, and N750, the cumulative CH4 emissions during the entire period, including cultivation and fallow period were 29.6, 18.1, 54.4, and 67.5 kg C ha(-1), respectively, whereas those of N2O were -0.15, -0.02, 1.49, and 5.82 kg N ha(-1), respectively. Considering the greenhouse gas emissions and above-ground biomass, the yield-scaled CO2-equivalents (CO2-eqs) were 66.3, 35.9, 161, and 272 kg CO2 t(-1) for N100, N250, N500, and N750, respectively. These results suggest that N250 is the most appropriate LCW loading rate for promoting forage rice production with lower GHG emissions.

Shifts between Nitrospira- and Nitrobacter-like nitrite oxidizers underlie the response of soil potential nitrite oxidation to changes in tillage practices.

Despite their role in soil functioning, the ecology of nitrite-oxidizing bacteria, NOB, and their response to disturbances such as those generated by agricultural practices are scarcely known. Over the course of 17 months, we surveyed the potential nitrite oxidation, PNO, the abundance of the Nitrobacter- and Nitrospira-like NOB (by quantitative PCR) and the community structure of the Nitrobacter-like NOB (by PCR-DGGE and cloning-sequencing targeting the nxrA gene) in soils for four treatments: after establishment of tillage on a previously no-tillage system, after cessation of tillage on a previously tillage system, and on control tillage and no-tillage systems. Key soil variables (moisture, organic carbon content and gross mineralization--i.e. ammonification--measured by the 15N dilution technique) were also surveyed. PNO was always higher for the no-tillage than tillage treatments. Establishment of tillage led to a strong and rapid decrease in PNO whereas cessation of tillage did not change PNO even after 17 months. PNO was strongly and positively correlated to the abundance of Nitrobacter-like NOB and was also strongly related to gross mineralization, a proxy of N-availability; in contrast, PNO was weakly and negatively correlated to the abundance of Nitrospira-like NOB. Selection of a dominant population was observed under no-tillage, and PNO was loosely correlated to the community structure of Nitrobacter-like NOB. Our results demonstrate that Nitrobacter-like NOB are the key functional players within the NOB community in soils with high N availability and high activity level, and that changes in PNO are due to shifts between Nitrospira-like and Nitrobacter-like NOB and to a weaker extent by shifts of populations within Nitrobacter-like NOB.

Expression of activated signal transducer and activator of transcription-3 predicts poor prognosis in cervical squamous-cell carcinoma.

BACKGROUND: Stat3 is a member of the Janus-activated kinase/STAT signalling pathway. It normally resides in the cytoplasm and can be activated through phosphorylation. Activated Stat3 (p-Stat3) translocates to the nucleus to activate the transcription of several molecules involved in cell survival and proliferation. The constitutive activation of Stat3 has been shown in various types of malignancies, and its expression has been reported to indicate a poor prognosis. However, the correlation between the constitutive activation of Stat3 and the prognosis of cervical cancer patients has not been reported. METHODS: The immunohistochemical analysis of p-Stat3 expression was performed on tissues from 125 cervical squamous-cell carcinoma patients who underwent extended hysterectomy and pelvic lymphadenectomy, and the association of p-Stat3 expression with several clinicopathological factors and survival was investigated. RESULTS: Positive p-Stat3 expression was observed in 71 of 125 (56.8%) cases and was significantly correlated with lymph node metastasis, lymph vascular space invasion, and large tumour diameter (>4 cm) by Fisher's exact test. Kaplan-Meier survival analysis showed that p-Stat3 expression was statistically indicative of a poor prognosis for overall survival (P=0.006) and disease-free survival (P=0.010) by log-rank test. CONCLUSION: These data showed that p-Stat3 expression in cervical cancer acts as a predictor of poor prognosis.

Experimental and simulation analysis of community structure of nitrifying bacteria in a membrane-aerated biofilm.

Until now, only few attempts have been made to assess biofilm models simulating microenvironments in a biofilm. As a first step, we compare the microenvironment observed in a membrane aerated biofilm (MAB) to that derived from a two-dimensional computational model with individual ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) embedded in a continuum EPS matrix. Gradients of oxygen were determined by means of microelectrodes. The change in nitrifying bacterial populations with the biofilm depth was quantified using fluorescence in situ hybridization (FISH) in combination with a confocal laser scanning microscopy (CLSM). Microelectrode measurements revealed that oxic and anoxic or anaerobic regions exist within the MAB. The oxygen profile predicted by the model showed good agreement with that obtained by microelectrode measurements. The oxic part of the biofilm was dominated by NSO190 probe-hybridized AOB, which formed relatively large clusters of cells directly on the membrane surface, and by the NOB belonging to genus Nitrobacter sp. On the other hand, NOB belonging to genus Nitrospira sp. were abundant at the oxic-anoxic interface. The model prediction regarding AOB and Nitrobacter sp. distribution was consistent with the experimental counterpart. Measurements of AOB cluster size distribution showed that colonies are slightly larger adjacent to the membrane than at the inner part of the biofilm. The sizes predicted by the current model are larger than those obtained in the experiment, leading to the arguments that some factors not contained in the model would affect the cluster size.

Efficacy and Safety of Salmeterol/fluticasone Combination Therapy in Infants and Preschool Children with Asthma Insufficiently Controlled by Inhaled Corticosteroids.

BACKGROUND: Clinical evidences of inhaled salmeterol/fluticasone propionate combination (SFC) therapy are insufficient in early childhood asthma. OBJECTIVES: To examine the effects of SFC50, a combination product of salmeterol xinafoate (50 µg/day) and fluticasone propionate (100 µg/day), in infants and preschool children with asthma. METHODS: The study was conducted at 31 sites in Japan. 35 patients (6 months to 5 years old) with asthma insufficiently controlled by inhaled corticosteroids (100 µg/day) were initiated to treat with SFC50 twice a day for 12 weeks with pressurized metered dose inhalers. The efficacy of SFC50 was assessed using nighttime sleep disorder score as the primary endpoint and the other efficacy measurements. The safety measurement included the incidences of adverse event (AE). RESULTS: Mean patient age was 3.1 years, and 94.2% had mild-to-moderate persistent asthma (atopic type: 65.7%). Nighttime sleep disorder scores, assessed by a nighttime sleep diary, significantly decreased after treatment with SFC50 throughout the study period (p<0.01). SFC50 also significantly improved other efficacy outcomes including asthma symptom score, frequency of short-acting beta-agonist treatment, frequency of unscheduled visits to clinic, frequency of exacerbation due to virus infection, asthma control score and patient QOL score (p<0.01). AEs of cold, upper respiratory inflammation and asthmatic attack occurred in each of the 3 patients (8.6%); however, these were not regarded as treatment-related AEs. CONCLUSIONS: SFC50 improved nighttime sleep disorder score and other efficacy outcome measures with no safety concerns. The results suggest that SFC50 treatment is useful to control the mild-to-moderate asthma in infant and preschool-aged children.

Synthesis and antiinflammatory activity of [(cycloalkylmethyl)phenyl]acetic acids and related compounds.

[(Cycloalkylmethyl)phenyl]acetic acid derivatives and related compounds were synthesized to test their antiinflammatory and analgesic activities. Some of the compounds in this series were found to have good activity in the carrageenan edema test. Among them, sodium 2-[4-[(2-oxocyclopentyl)methyl] phenyl]propionate dihydrate (15) and 2-[4-[(2-oxocyclohexylidene)methyl]phenyl]propionic acid (13b) showed potent analgesic and antiadjuvant arthritis activities with excellent antipyretic properties.

Synthesis and thromboxane synthetase inhibitory activity of di- or tetrahydrobenzo[b]thiophenecarboxylic acid derivatives.

1-Imidazolylalkyl-substituted di- or tetrahydrobenzo[b]thiophenecarboxylic acid derivatives and related compounds were synthesized from tetrahydrobenzo[b]thiophene derivatives (1 or 4) in order to study the structure-activity relationships of the inhibition of thromboxane A2 synthetase in vitro. Sodium 2-(1-imidazolylmethyl)-4,5-dihydrobenzo[b]thiophene-6-carboxylate (26) and 2-(1-imidazolylmethyl)-4,5,6,7-tetrahydrobenzo[b]thiophene-6-carbo xylic acid hydrochloride (28) showed the most potent and specific activity in vitro for thromboxane A2 synthetase inhibition.

Effect of intravenous administration of EM523L on gastric emptying and plasma glucose levels after a meal in patients with diabetic gastroparesis: a pilot study.

EM523L, a newly developed erythromycin derivative, has a powerful motilin-like biologic effect and no antibacterial activity. In this pilot study, EM523L was administered to six patients with diabetic gastroparesis, and its effects on gastric emptying function and the change in plasma glucose levels after eating were examined. Gastric emptying was evaluated by the simultaneous measurement of solid and liquid food intake using 99mTc-Sn-colloid and acetaminophen, respectively. Eggs labeled with isotope and milk with added acetaminophen were used as the test meals. The change in plasma glucose level after ingestion of the test meal was also examined. A total of 2 mg of EM523L dissolved in 100 mL of physiologic saline was administered by intravenous infusion over a period of 15 minutes after ingestion of the test meal. The retention rates of the gastric isotope decreased following the administration of EM523L at 20 to 120 minutes after ingestion of the test meal. Plasma acetaminophen concentrations following EM523L administration increased at 20 and 30 minutes. The plasma glucose levels showed an increase at 30 to 60 minutes after eating--the result of improved gastric emptying function. From these results, we concluded that intravenous administration of EM523L in patients with severe diabetic gastroparesis promotes gastric emptying of a solid and liquid meal and, as a result, plasma glucose levels increase after eating.

Effect of omeprazole on changes in gastric and upper small intestine pH levels in patients with chronic pancreatitis.

Gastric and upper small intestine pH levels were measured continuously over 24 hours in patients with chronic pancreatitis, and values obtained before and after the administration of omeprazole were compared. Additionally, omeprazole was administered for 2 weeks and the fecal excretion of fat was compared before and after drug therapy. Postprandial gastric pH levels, initially 2.9 to 3.2, increased by 1.6 to 2.1 after treatment. Postprandial upper small intestine pH levels, initially 5.1 to 5.5, increased by 0.7 to 1.0. The lowest pH value of the upper small intestine was 2.2 to 2.4 postprandially; this was increased by > 1.0 after omeprazole, and the amplitude of pH variation was reduced. The cumulative proportions of intraintestinal pH strata of < or = 3, < or = 4, or < or = 5, and higher, initially being 16.4% to 17.1%, 27.4% to 31.7%, and 52.6% to 57.8%, respectively, were remarkably improved after drug treatment. Gastric pH and upper small intestine pH levels showed a positive correlation; an increase in gastric pH levels by 2 corresponded to an increase in small intestine pH levels by 1. After omeprazole administration, mean fecal excretion of fat was decreased to 4.1 +/- 2.6 g/d (range, 1.1 to 9.8 g/d) from 6.5 +/- 3.9 g/d (range, 1.6 to 13.5 g/d). Decreases in excretion of fat averaged 3.4 g/d (range, 2.2 to 4.5 g/d) in patients with steatorrhea. It was concluded that steatorrhea due to chronic pancreatitis can be improved to some extent by improving upper small intestine pH levels following the elevation of gastric pH levels after administration of omeprazole.

Effects of CS-518, a thromboxane synthase inhibitor, on the asthmatic response.

The anti-asthmatic effects of CS-518 (sodium 2-(1-imidazolylmethyl)-4,5-dihydrobenzo[b]thiophene-6-carboxylate) , a specific thromboxane A2 (TXA2) synthase inhibitor, were investigated in the ovalbumin-sensitized guinea pig asthmatic model. Although CS-518 slightly inhibited (about 25%) whole bronchoconstriction, it significantly inhibited the antigen-induced bronchoconstriction mediated by slow-reacting substance of anaphylaxis (SRS-A), which was not reduced by chlorpheniramine, a histamine H1 antagonist. On the other hand, indomethacin, a cyclooxygenase inhibitor, potentiated the SRS-A-mediated constriction. CS-518 strongly, and indomethacin slightly, suppressed the leukotriene D4-induced bronchoconstriction. CS-518 clearly inhibited the antigen-induced airway hyperresponsiveness, but this compound had no effect on the airway hyperresponsiveness induced by U-46619, a TXA2-mimetic agent, and propranolol. These results suggest that CS-518 suppresses the development of bronchoconstriction and airway hyperresponsiveness in asthmatic models by inhibition of TXA2 synthesis with the concomitant increase in bronchodilating prostaglandins such as prostaglandin E2 and prostaglandin I2.

Correlation between bile acid malabsorption and pancreatic exocrine dysfunction in patients with chronic pancreatitis.

Fecal bile acid and fecal fat were determined in 18 normal subjects and 22 patients with chronic pancreatitis, and the relation of fecal bile acid excretion to exocrine pancreatic dysfunction was studied. In chronic pancreatitis fecal bile acid was approximately three times that of control subjects, and large amounts of primary bile acid were detected. A significant correlation between fecal bile acid excretion and bicarbonate secreted from the pancreas was found. This evidence of bile acid malabsorption was not observed until bicarbonate output was < 0.05 mEq/h/kg. A slight correlation between fecal bile acid and absorption rates of fat was demonstrated. These results suggest that bile acid malabsorption observed in chronic pancreatitis is related to an impairment of pancreatic bicarbonate secretion.

Effects of intestinal bacteria on the development of colonic neoplasm: an experimental study.

Effects of intestinal microflora on the development of colonic neoplasm induced by 1,2-dimethylhydrazine (DMH) were observed using conventionalized and gnotobiotic mouse models. The incidence of colonic adenoma in germ-free mice (IQI/jic) (GF), mice conventionalized after DMH injection (Cvz-post-DMH) and conventionalized mice (Cvz, conventionalized before DMH injection) was 74%, 69% and 58%, respectively. The mean number of adenomas per mouse in the three groups was 2.6, 2.0 and 1.4, respectively. However, the adenoma in Cvz was larger than in GF. The incidence of adenoma in mice mono-associated with Mitsuokella multiacida, Clostridium butyricum, Bifidobacterium longum, Clostridium paraputrificum, Escherichia coli and Lactobacillus acidophilus was 68%, 68%, 63%, 50%, 50% and 30%, respectively. However, the adenoma in the Cl. paraputrificum group and the Cl. butyricum group was larger than in GF. Faecal pH in Cvz and the L. acidophilus group was significantly lower than in GF. The deconjugation rate of faecal bile acids in Cvz, the Cl. paraputrificum group and the Cl. butyricum group was significantly higher than in GF. These findings suggested two different effects of microflora on the development of DMH-induced adenoma: either an inhibition of the incidence of adenoma or a promotion of tumour growth. Effects of L. acidophilus may be mediated by faecal pH and effects of Cl. paraputrificum and Cl. butyricum by deconjugated bile acids.

RS-5186, a novel thromboxane synthetase inhibitor with a potent and extended duration of action.

RS-5186, sodium 6-[2-[1-(1H)-imidazolyl]methyl-4,5-dihydrobenzo[b]thiophene]- carboxylate, inhibited platelet thromboxane A2 (TXA2) synthetase with IC50 values of 6 nM and 13 nM for human and rabbit microsomes, respectively. It had a selectivity for TXA2 synthetase 10(5)-fold greater than that for cyclooxygenase, PGI2 synthetase, 5-lipoxygenase and phospholipase A2. When administered orally or intravenously to dogs at 1 mg/kg, RS-5186 suppressed serum TXB2 levels almost completely with sustained duration of action: the suppression during 0.5 hr to 8 hr after dosing was more than 90%, and was 70-80% at 24 hr. Similar suppression of serum TXB2 levels was observed in rats and rabbits. Such suppression by RS-5186 was more potent than that by OKY-046 and CV-4151. Serial administration of RS-5186 (0.1 mg/kg/day p.o.) to dogs for 7 days decreased the serum TXB2 levels constantly during the medication, and no rebound phenomenon was observed after the medication was stopped. In a thrombotic model induced by sodium arachidonate injection in rabbits, RS-5186 at 1 mg/kg p.o. completely protected against sudden death (ED50 = 0.12 mg/kg, 1 hr after dosing) and this protective effect extended over 8 hr. All these results show that RS-5186 is a potent and highly selective TXA2 synthetase inhibitor with a long duration of action, and suggest that the compound could be useful in diseases where TXA2 is involved.

Dietary analysis of Japanese patients with chronic pancreatitis in stable conditions.

In order to examine the malnutritional condition of outpatients with pancreatitis, a dietary investigation was conducted in Japanese patients with chronic pancreatitis (n = 38) and healthy subjects (n = 35) of the same age for 3-7 consecutive days, and the characteristics of their food intake were examined. The patients with pancreatitis took in less calories, fat, carbohydrate, and protein than the healthy subjects, by 900 kcal, 20 g, 150 g, and 20 g, respectively. On the other hand, the fat energy ratio in the patients was 20%, similar to that in the healthy subjects. Also, when the fat intake was classified according to origin, i.e., animal, marine, or plant, the proportions for animal (g) and plant (g) were low, while marine fat accounted for a significantly higher percentage than in the healthy subjects. The intake of cholesterol and Ca in the patients was significantly smaller than that in the healthy subjects, but no significant difference was observed in the intake per body weight of proteins and Ca. It seems, possible that the low calorie, low protein, low fat, and low carbohydrate intake may be factors in the malnutritional condition of the patients with chronic pancreatitis. Analysis of covariance and principal component analysis showed that the body weight of the patients was closely correlated with decreases of caloric intake and intake of carbohydrate. The above results revealed that low body weight in patients with chronic pancreatitis was closely related to the decrease of calorie and carbohydrate intake, in addition to maldigestion and malabsorption of nutrients.

Effect of a probiotic formula on intestinal immunoglobulin A production in healthy children.

The anti-infectious effect of probiotics has recently been reported and one mechanism may be the non-specific stimulation of immunity. This study was performed to elucidate the influence of a probiotic formula on intestinal microflora and local immunity in healthy children. A follow-up formula containing viable bifidobacteria was given to seven healthy Japanese children (15 to 31 months old) for 21 days. During intake of the formula, the administered strain was detected in feces from five subjects (71%) and total fecal bifidobacteria slightly increased. Fecal levels of total IgA and anti-poliovirus IgA during intake of the formula were significantly higher than those before intake (P < 0.05). The increase in local IgA levels resulting from ingestion of the probiotic formula may contribute to enhancement of the mucosal resistance against gastrointestinal infections.

Active oxygen species generation and cellular damage by additives of parenteral preparations: selenium and sulfhydryl compounds.

We investigated the relationship between active oxygen species (AOS) generation and cultured vascular endothelial cellular damage caused by simultaneous exposure to selenium compounds and sulfhydryl compounds such as cysteine (Cys) or reduced glutathione (GSH). Selenium compounds, selenite, selenate or selenomethionine (SeMet), are added to total parenteral nutrition (TPN) and intravenously administered. We confirmed by luminol dependent chemiluminescence, an indicator of AOS generation, that selenite generates AOS in the presence of clinical concentrations of sulfhydryl compounds, 0.5 mM Cys or 0.5 mM GSH, and that the amount of AOS generated reaches the maximum when their mole ratio is 1:50. However, AOS generation was not observed after simultaneous administration of various concentrations of selenate or SeMet with sulfhydryl compounds. Moreover, simultaneous exposure to 10 microM selenite and sulfhydryl compounds was found to result in significant increases in the [3H]-adenine and lactate dehydrogenase (LDH) release rates from cells, a significant decrease in the amount of cellular protein, and enhancement of cellular damage as compared with after exposure to selenite alone. However, simultaneous exposure to 10 microM selenate or 10 microM SeMet together with sulfhydryl compounds did not induce cellular damage. These findings revealed that selenite generates AOS and causes cellular damage in the presence of sulfhydryl compounds. Accordingly, it seems better to choose selenate or SeMet instead of selenite when a selenium compound is to be added to TPN.

Age affects hibernation in Syrian hamsters (Mesocricetus auratus).

In this study, we aimed to show how age affects hibernation in the Syrian hamster. Experimentally, we used 30 male animals differing in age. The old animals were 20 months of age and the adults were 8 months of age at the end of the test. The young animals were 3 weeks old at the start of testing and 5 months old at the end of the testing period. The torpor observation started October 15, 1996, and ended March 11, 1997, in the laboratory colony maintained under natural photoperiod and outdoor air. Observations were performed around noon daily. Three measures (i.e., prehibernation period [hibernation latency], proportion of hibernation spent in torpor, and proportion of animals in torpor), all of which reflect the strength of occurrence of hibernation, indicated that the older hamsters (1) started hibernation earlier, (2) spent more time in torpor, and (3) had a higher chance of being in torpor than the younger ones during the hibernation season.

Selenium administration to a ten-year-old patient receiving long-term total parenteral nutrition (TPN)--changes in selenium concentration in the blood and hair.

Muscle pain in the lower limbs occurred in a child with short bowel syndrome who has been receiving longterm total parenteral nutrition (TPN). Biochemical parameters revealed that the plasma and erythrocyte selenium concentrations were below the normal range for children and intravenous injection of selenium prepared from selenious acid was started at a dose of 100 micrograms per day. Muscle pain in the lower limbs disappeared one month afterwards. At this point in time, the elevation of the plasma selenium concentration was noted but the erythrocyte selenium concentration remained low. When administration was suspended due to catheter-induced fever five months later, the whole blood selenium concentration decreased again and the symptoms recurred. Accordingly, the dose of selenium was increased to 200 micrograms/day. Subsequently, the blood selenium concentration recovered to the normal range for children. After the dose increase to 200 micrograms/day, concentrations in hair samples collected at every centimeter distance from the root end were determined. The selenium concentration at the root end was found to be higher than the normal range for children, indicating that this was an excessive dose case. Although the dose was decreased from 200 micrograms/day to 120 micrograms/day, the plasma and erythrocyte selenium levels did not go down. Furthermore, the selenium level in the hair reached a plateau, and no recurrence of symptoms was observed. The above results indicate the usefulness of monitoring the selenium concentration in hair in addition to determining the blood selenium level and GSH-Px activity in administering selenium to children undergoing TPN.

Influence of combined use of selenious acid and SH compounds in parenteral preparations.

The influence of the combined use of selenious acid and SH compounds (glutathione (GSH) and cysteine (Cys), or ascorbic acid (Asc)) on cultured venous vascular cells was investigated experimentally. When cultured human umbilical venous vascular endothelial cells were exposed to 10 microM of selenious acid combined with 0.5 mM-GSH or 0.5 mM-Cys, the release rates of [3H]-adenine and lactate dehydrogenase (LDH) from cells into the medium increased significantly as compared with after exposure to selenious acid alone, and damage to the vascular endothelial cells was found to be intensified. Addition of 1 microM of selenious acid simultaneously with 0.5 mM-GSH or 0.5 mM-Cys showed no differences in toxicity for the vascular endothelial cells as compared with the addition of selenious acid alone. On the other hand, simultaneous exposure to 10 microM of selenious acid and 1 mM-Asc induced no significant differences in the release rates of [3H]-adenine and LDH, and no damage was observed to the vascular endothelial cells. These results suggest that simultaneous addition of selenious acid together with GSH or Cys, which have the SH-group, may cause damage to the vascular endothelial cells. Therefore careful attention is warranted in total parenteral nutrition (TPN).