Quantitative prediction of the growth inhibition of various harmful chemicals by statistical analysis of delayed fluorescence decay curves obtained from the green alga Raphidocelis subcapitata

The toxicity of chemical substances to algal growth is generally measured by the 72-96 h algal growth inhibition test. We have developed a method to assess the toxicity of chemicals in aquatic environments more quickly and simply than conventional testing methods by delayed fluorescence (DF), which reflects the photosynthetic capacity of algae. The DF method is based on a technique for evaluating the amount of change in the decay curve due to the effects of chemicals ([Formula: see text], DF inhibition). Various studies on DF have been reported; however, few reports have evaluated the decay curve of DF by approach using inductive modeling based on measurement data such as principal component analysis (PCA) and partial least squares regression analysis (PLS). Therefore, the purpose of this study is to examine methods for estimating the magnitude and type of toxicity of chemicals by means of a principal component model (PC model) and multiple regression model (MR model) derived from changes in the decay curves of DF of algae exposed to a wide range of 37 toxic substances that have an effect of clear magnitude on algal growth. The changes in the DF decay curves due to exposure the 37 toxic substances to algae were summarized in the PC model composed of eigenvectors and scores of four principal components. For validation of usefulness, a hierarchical cluster analysis (HCA) of the amount of change in four PC scores revealed that the growth inhibition rate was more influential than the chemical type. We also found the possibility of quantitatively predicting the growth inhibition of chemicals by MR model by the amount of change in the PC scores.

Succession of delayed fluorescence correlated with coral bleaching in the hermatypic coral Acropora tenuis

We investigated coral bleaching by monitoring colour changes and measuring the delayed fluorescence (DF) of symbiotic dinoflagellates in the hermatypic coral Acropora tenuis, exposed to 1.0 μg/L Irgarol 1051 (photosystem II herbicide) for 14 d. The Irgarol concentration corresponded to those from international port regions of the world. The coral colour and DFs under the control treatment were stable throughout the experiment, whereas under the Irgarol treatment the corals showed gradual bleaching. The Irgarol treatment caused a rapid decrease in the slow decay DF component (10.1-60.0 s), while the fast decay DF component (0.1-10.0 s) decreased significantly after 6 d. The significant correlation between the latter values and the coral colour indicates that if the electron accumulation function of quinones Q_A and Q_B is compromised, corals will bleach. The present study will contribute to the understanding of the mechanism involved in bleaching of coral exposed to herbicides.

Evaluation of the toxicity of leaches from hydrothermal sulfide deposits by means of a delayed fluorescence-based bioassay with the marine cyanobacterium Cyanobium sp. NIES-981

The commercial use of metals such as copper, lead, and zinc has markedly increased in recent years, resulting in increased interest in deep-sea mining of seafloor hydrothermal sulfide deposits. However, the full extent of the impact of deep-sea mining at hydrothermal field deposits on the environment remains unclear. In addition to impacting the deep sea, the leaching of heavy metals from extracted sulfide mineral may also affect the upper ocean zones as the sulfide rock is retrieved from the seafloor. Here, we used a delayed fluorescence-based bioassay using the marine cyanobacterium Cyanobium sp. NIES-981 to evaluate the toxicity of three sulfide core samples obtained from three drill holes at the Izena Hole, middle Okinawa Trough, East China Sea. Leaches from two of the cores contained high concentrations of zinc and lead, and they markedly inhibited delayed fluorescence in Cyanobium sp. NIES-981 compared with control. By examining the toxicity of artificial mixed-metal solutions with metal compositions similar to those of the leaches, we confirmed that this inhibition was a result of high zinc and lead concentrations into the leaches. In addition, we conclude that this delayed fluorescence-based bioassay is a viable method for use by deep-sea mining operations because it is quicker and requires less laboratory space and equipment than the standard assay.

Validation of rapid algal bioassay using delayed fluorescence in an interlaboratory ring study

Algal growth inhibition tests are generally used to determine the toxic effects of chemical substances on algae growth. In this report, we describe a rapid and simple test procedure using delayed fluorescence (DF) to determine chemical toxicities more rapidly than the conventional 72h or 96h growth inhibition tests. We assess the suitability of DF to serve as an alternative endpoint for biomass production and determine the variability by an interlaboratory ring study using a typical reference toxicant 3,5-dichlorophenol (DCP). The results suggest that DF has the potential to be used as a surrogate measure of photosynthetically-active biomass in the algal growth inhibition tests. The half maximal effective concentration (EC₅₀) values of DCP determined from the DF inhibition test in 6h and 24h (1.2±0.3mg/L and 2.7±0.5mg/L respectively) are in reasonable agreement with the EC₅₀ value of DCP determined by the 72h conventional method (1.8mg/L). In the interlaboratory ring study, the intralaboratory and interlaboratory variabilities of the EC₅₀ of the DF inhibition test for a 24h exposure period are 12% and 28% respectively. DF intensity can be considered as a surrogate of living biomass with active photosynthesis, and we conclude that a 24h exposure duration better estimates the toxic effects measured using conventional surrogate measures for dry weight such as cell counts, volume, optical density or fluorescence.

Delayed fluorescence as an indicator of the influence of the herbicides Irgarol 1051 and Diuron on hard coral Acropora digitifera

We examined the effect of two herbicides (Irgarol 1051 and Diuron) on symbiotic dinoflagellates in the hard coral Acropora digitifera using delayed fluorescence (DF), specifically assessing changes in molecular membrane transport, i.e. inflow and outflow rates, and the binding of the herbicides to target proteins in photosystem II. The DF approach is rapid (e.g. measurement time, 60 s) and non-invasive, and can provide data on the extent of a photosynthetic system and the activity of its electron carriers. The DF of A. digitifera is inhibited 2 h after exposure to 1 μg/L of either Irgarol or Diuron. Analysis of DF inhibition over time by a compartment model suggests that Irgarol exposure results in a relatively higher inflow rate and lower outflow rate than does Diuron exposure. This suggests that Irgarol exposure more strongly inhibits photosynthesis and that the coral symbiotic dinoflagellates recover less from inhibition.

Rapid ecotoxicological bioassay using delayed fluorescence in the marine cyanobacterium Cyanobium sp. (NIES-981)

The use of delayed fluorescence intensity as an endpoint for rapid estimation of the effective concentration (EC_x) has been reported as an alternative to standard growth inhibition (at 72 h after exposure) in some algal species including Pseudokirchneriella subcapitata. In marine algae, although an approach of bioassaying using delayed fluorescence measurements has not been performed yet, its development would provide many benefits for marine environmental risk assessment. In this study, we selected marine cyanobacterium Cyanobium sp. (NIES-981) as our test algal species and demonstrated that this species is valid for the standard growth inhibition test based on criteria provide by Organization for Economic Co-operation and Development guidelines. Furthermore, standard inhibition tests and shorter period test using DF were performed in NIES-981 using five chemicals (3,5-DCP, simazine, diflufenican, K₂Cr₂O₇, and CuSO₄), and their EC₅₀ and low-toxic-effect values (EC₁₀, EC₅, and NOEC) were determined from two dose-response curves. Based on comparisons of the two dose-response curves and the EC₅₀ values, we conclude that DF intensity is useful as an endpoint for rapid estimation of EC₅₀ in NIES-981.

Dangerous Mixture of Household Detergents in an Old-style Toilet: a Case Report with Simulation Experiments of the Working Environment and Warning of Potential Hazard Relevant to the General Environment

A housewife cleaned toilet porcelain connected directly to a sewage storage tank with a mixture of cleaning agents; sodium hypochlorite (NaOCl) and hydrochloric acid (HCl) solutions. She complained of insomnia on the night after cleaning and suffered from severe metabolic acidosis with extremely low blood pH, PCO2 and bicarbonate values. She recovered from the acidosis after bicarbonate transfusion, plasmapheresis and plasma exchange. Permanent blindness ensued, however, from the third day after the event. These clinical symptoms suggested that the toxic substances responsible were chloramine and methyl chloride. Their generation was confirmed by in-vitro experiments, mixing NaOCl, HCl and pooled urine from normal people. In the simulation, the methyl chloride level far exceeded (100 000 ppm) the maximal allowable concentration recommended (ca 400 ppm) by the American Conference of Governmental Industrial Hygienists (ACGIH). Chloramine's toxic actions were confirmed using purified enzyme assay, and the inhibition of carbonic anhydrase and aldehyde dehydrogenase and the enhancement of superoxide dismutase activity were confirmed in neutral pH. The patient's clinical symptoms suggested that insomnia and permanent blindness seemed to be partly ascribable to chronic repetitive exposure to methyl chloride; catching a cold, drug intake and alcohol intake, in addition, precipitated the patient's visual loss. The possibility of this kind of intoxication with such a mixture of agents may lie latent in any situation where sewage or garbage are exposed to the open air.

Nondestructive evaluation of photosynthesis by delayed luminescence in Arabidopsis in Petri dishes

Nondestructive evaluation of photosynthesis is a valuable tool in the field and laboratory. Delayed luminescence (DL) can reflect charge recombination through the backflow of electrons. However, DL detection has not yet been adapted for whole plants in Petri dishes. To compensate for differences in DL decay between sibling Arabidopsis plants grown under the same conditions, we developed a time-sequential double measurement method. Using this method, we examined the influence of photosynthetic electron flow inhibitors, and differences in the DL decay curves were categorized by considering the initial and late phases of the decay curves, as well as their intermediate slopes. The appearance of concavity and convexity in DL curves in Arabidopsis was different from unicellular algae, suggesting complexity in the photosynthetic machinery of higher plants. This detection method should be invaluable for evaluating photosynthetic defects in higher plants under sterile conditions without interrupting plant culture.

Lunisolar tidal synchronism with biophoton emission during intercontinental wheat-seedling germination tests

Synchronic measurements of spontaneous ultra-weak light emission from germinating wheat seedlings both in Brazil and after transportation to Japan, and with a simultaneous series of germinations with local seedlings in the Czech Republic, are presented. A series of tests was also performed with samples returned from Japan to Brazil and results compared with those from undisturbed Brazilian seedlings. Native seedlings presented semi-circadian rhythms of emission which correlated with the gravimetric tidal acceleration at their locality, as did seeds which had been transported from Brazil to Japan, and then returned to Brazil. Here, however, there were very small disturbances within the periodicity of emissions, perhaps as a result of similar tidal profiles at locations whose longitudes are 180° apart, as in this case, different from previous results obtained in Brazil-Germany tests with other longitude shift. This feature of the Brazil and Japan locations may have minimized the requirement for the acclimatization of the transported seed to their new location.

Simultaneous monitoring of superoxides and intracellular calcium ions in neutrophils by chemiluminescence and fluorescence: evaluation of action mechanisms of bioactive compounds in foods

We have developed a measuring system for simultaneous monitoring of chemiluminescence and fluorescence, which indicate respectively, (i) generation of superoxide anion radicals (O2(-•)) and (ii) change in the intracellular calcium ion concentration ([Ca(2+)]i) of neutrophils triggered by the mechanism of innate immune response. We applied this measuring system for establishing a method to distinguish between anti-inflammatory actions and antioxidant actions caused by bioactive compounds. We evaluated anti-inflammatory agents (zinc ion [Zn(2+)] and ibuprofen) and antioxidants (superoxide dismutase [SOD] and ascorbic acid). It was shown that ibuprofen and Zn(2+) were anti-inflammatory while SOD and ascorbic acid were anti-oxidative. We conclude that it is possible to determine the mechanism of action of bioactive compounds using this method.

Production of monozygotic twins following the transfer of bisected embryos in the goats

Embryos at the morula, blastocyst and hatched blastocyst stage were obtained from superovulated and naturally ovulated Japanese native goats. They were bisected into halves with a glass needle, and transferred immediately or after culture (for morula) to recipients. None of five does which received bisected morula became pregnant. Three of nine goats became pregnant after transfer of bisected hatched blastocysts, six of eleven recipients became pregnant. Four of them produced monozygotic twins and the remaining two produced singles. The present study demonstrated that the hatched blastocyst is suitable for bisection in the goat.

A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects

We previously reported that 2-night/3-day trips to forest parks enhanced human NK activity, the number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that this increased NK activity lasted for more than 7 days after the trip in both male and female subjects. In the present study, we investigated the effect of a day trip to a forest park on human NK activity in male subjects. Twelve healthy male subjects, aged 35-53 years, were selected after giving informed consent. The subjects experienced a day trip to a forest park in the suburbs of Tokyo. They walked for two hours in the morning and afternoon, respectively, in the forest park on Sunday. Blood and urine were sampled in the morning of the following day and 7 days after the trip, and the NK activity, numbers of NK and T cells, and granulysin, perforin, and granzyme A/B-expressing lymphocytes, the concentration of cortisol in blood samples, and the concentration of adrenaline in urine were measured. Similar measurements were made before the trip on a weekend day as the control. Phytoncide concentrations in the forest were measured. The day trip to the forest park significantly increased NK activity and the numbers of CD16(+) and CD56(+) NK cells, perforin, granulysin, and granzyme A/B-expressing NK cells and significantly decreased CD4(+) T cells, the concentrations of cortisol in the blood and adrenaline in urine. The increased NK activity lasted for 7 days after the trip. Phytoncides, such as isoprene, alpha-pinene, and beta-pinene, were detected in the forest air. These findings indicate that the day trip to the forest park also increased the NK activity, number of NK cells, and levels of intracellular anti-cancer proteins, and that this effect lasted for at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity.

Effect of phytoncide from trees on human natural killer cell function

We previously reported that the forest environment enhanced human natural killer (NK) cell activity, the number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that the increased NK activity lasted for more than 7 days after trips to forests both in male and female subjects. To explore the factors in the forest environment that activated human NK cells, in the present study we investigate the effect of essential oils from trees on human immune function in twelve healthy male subjects, age 37-60 years, who stayed at an urban hotel for 3 nights from 7.00 p.m. to 8.00 a.m. Aromatic volatile substances (phytoncides) were produced by vaporizing Chamaecyparis obtusa (hinoki cypress) stem oil with a humidifier in the hotel room during the night stay. Blood samples were taken on the last day and urine samples were analysed every day during the stay. NK activity, the percentages of NK and T cells, and granulysin, perforin, granzyme A/B-expressing lymphocytes in blood, and the concentrations of adrenaline and noradrenaline in urine were measured. Similar control measurements were made before the stay on a normal working day. The concentrations of phytoncides in the hotel room air were measured. Phytoncide exposure significantly increased NK activity and the percentages of NK, perforin, granulysin, and granzyme A/B-expressing cells, and significantly decreased the percentage of T cells, and the concentrations of adrenaline and noradrenaline in urine. Phytoncides, such as alpha-pinene and beta-pinene, were detected in the hotel room air. These findings indicate that phytoncide exposure and decreased stress hormone levels may partially contribute to increased NK activity.

Utility of delayed fluorescence as endpoint for rapid estimation of effect concentration on the green alga Pseudokirchneriella subcapitata

Algal growth inhibition tests for environmental risk assessment require improved efficiency to evaluate large numbers of chemicals. As an endpoint for rapid estimation of the effect concentration of test chemicals, we propose the delayed fluorescence (DF) measurement from an alga 24 h after exposure. Eight chemicals (bifenox, bromoxynil, bensulfuronmethyl, diuron, diflufenican, thiobencarb, m-chlorophenylhydrazone and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone) were tested. The EC50 values from the 24 h DF measurement were similar to those from the conventional 72 h growth test for seven tested chemicals excepting thiobencarb. We conclude that 24 h DF measurement is a possible endpoint for rapid estimation of the EC50 values obtained in the 72 h growth test for those seven chemicals.

Visiting a forest, but not a city, increases human natural killer activity and expression of anti-cancer proteins

We previously reported that a forest bathing trip enhanced human NK activity, number of NK cells, and intracellular anti-cancer proteins in lymphocytes. In the present study, we investigated how long the increased NK activity lasts and compared the effect of a forest bathing trip on NK activity with a trip to places in a city without forests. Twelve healthy male subjects, age 35-56 years, were selected with informed consent. The subjects experienced a three-day/two-night trip to forest fields and to a city, in which activity levels during both trips were matched. On day 1, subjects walked for two hours in the afternoon in a forest field; and on day 2, they walked for two hours in the morning and afternoon, respectively, in two different forest fields; and on day 3, the subjects finished the trip and returned to Tokyo after drawing blood samples and completing the questionnaire. Blood and urine were sampled on the second and third days during the trips, and on days 7 and 30 after the trip, and NK activity, numbers of NK and T cells, and granulysin, perforin, and granzymes A/B-expressing lymphocytes in the blood samples, and the concentration of adrenaline in urine were measured. Similar measurements were made before the trips on a normal working day as the control. Phytoncide concentrations in forest and city air were measured. The forest bathing trip significantly increased NK activity and the numbers of NK, perforin, granulysin, and granzyme A/B-expressing cells and significantly decreased the concentration of adrenaline in urine. The increased NK activity lasted for more than 7 days after the trip. In contrast, a city tourist visit did not increase NK activity, numbers of NK cells, nor the expression of selected intracellular anti-cancer proteins, and did not decrease the concentration of adrenaline in urine. Phytoncides, such as alpha-pinene and beta-pinene were detected in forest air, but almost not in city air. These findings indicate that a forest bathing trip increased NK activity, number of NK cells, and levels of intracellular anti-cancer proteins, and that this effect lasted at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone may partially contribute to the increased NK activity.

A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects

We previously reported that forest bathing trips enhanced human NK activity, number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that the increased NK activity lasted for more than 7 days after the trip in male subjects. In the present study, we investigated the effect of forest bathing trip on human NK activity in female subjects. Thirteen healthy nurses, age 25-43 years, professional career 4-18 years, were selected with informed consent. The subjects experienced a three-day/two-night trip to forest fields. On day 1, the subjects walked for two hours in the afternoon in a forest field; on day 2, they walked for two hours each in the morning and afternoon in two different forest fields; and on day 3, the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire. Blood and urine were sampled on the second and third days during the trip, and on days 7 and 30 after the trip. NK activity, numbers of NK and T cells, and granulysin, perforin, and granzymes A/B-expressing lymphocytes in the blood samples, the concentrations of estradiol and progesterone in serum, and the concentrations of adrenaline and noradrenaline in urine were measured. Similar control measurements were made before the trip on a normal working day. The concentrations of phytoncides in the forests were measured. The forest bathing trip significantly increased NK activity and the numbers of NK, perforin, granulysin, and granzymes A/B-expressing cells and significantly decreased the percentage of T cells, and the concentrations of adrenaline and noradrenaline in urine. The increased NK activity lasted for more than 7 days after the trip. Phytoncides, such as alpha-pinene and beta-pinene were detected in forest air. These findings indicate that a forest bathing trip also increased NK activity, number of NK cells, and levels of intracellular anti-cancer proteins in female subjects, and that this effect lasted at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity.

New feature of delayed luminescence: preillumination-induced concavity and convexity in delayed luminescence decay curve in the green alga Pseudokirchneriella subcapitata

A new method for measuring delayed luminescence (delayed fluorescence) employs preillumination and a dark waiting period before normal excitation. The preillumination results in a concavity and a convexity in the decay curve in delayed luminescence in the green alga Pseudokirchneriella subcapitata. Formation of the concavity and the convexity is not affected by excitation wavelength (680 nm and 700 nm). However, the concavity and the convexity progressively decrease as the dark waiting period increases after preillumination. The formation of the concavity and the convexity was inhibited by exposure to the electron transport inhibitors DBMIB (644 microg/L, 2.0 microM) and Antimycin A (55 microg/L, 0.1 microM). Samples exposed to DBMIB exhibited noticeable reduction in the concavity, whereas samples exposed to Antimycin A exhibited pronounced reduction in the convexity. There is a possibility that the formation and disappearance of the concavity and the convexity are due to the reduction-oxidation state of the plastoquinone pool and the cyclic electron transport. We expect this method being useful in evaluating the effects of chemicals (particularly toxic chemicals) on photosynthetic reactions, and the method may also help to resolve questions regarding the source of long delayed luminescence.

Forest bathing enhances human natural killer activity and expression of anti-cancer proteins

In order to explore the effect of forest bathing on human immune function, we investigated natural killer (NK) activity; the number of NK cells, and perforin, granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields. Twelve healthy male subjects, age 37-55 years, were selected with informed consent from three large companies in Tokyo, Japan. The subjects experienced a three-day/two-night trip in three different forest fields. On the first day, subjects walked for two hours in the afternoon in a forest field; and on the second day, they walked for two hours in the morning and afternoon, respectively, in two different forest fields. Blood was sampled on the second and third days, and NK activity; proportions of NK, T cells, granulysin, perforin, and granzymes A/B-expressing cells in PBL were measured. Similar measurements were made before the trip on a normal working day as the control. Almost all of the subjects (11/12) showed higher NK activity after the trip (about 50 percent increased) compared with before. There are significant differences both before and after the trip and between days 1 and 2 in NK activity. The forest bathing trip also significantly increased the numbers of NK, perforin, granulysin, and granzymes A/B-expressing cells. Taken together, these findings indicate that a forest bathing trip can increase NK activity, and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins.

Effects of orally administered glycine on myofibrillar proteolysis and expression of proteolytic-related genes of skeletal muscle in chicks

We examined the effects of orally administered glycine on myofibrillar proteolysis in food-deprived chicks. Food-deprived (24 h) chicks were orally administered 57, 113, and 225 mg glycine/100 g body weight and killed after 2 h. The plasma N(tau)-methylhistidine concentration, used as myofibrillar proteolysis, was decreased by glycine. We also examined the expression of proteolytic-related genes by real-time PCR of cDNA from chick skeletal muscles. The mRNA expression of atrogin-1/MAFbx, proteasome C2 subunit, m-calpain large subunit, and cathepsin B was decreased by glycine in a dose-dependent manner. The plasma corticosterone concentration was also decreased by glycine, but the plasma insulin concentration was unaffected. These results indicate that orally administered glycine suppresses myofibrillar proteolysis and expression of proteolytic-related genes of skeletal muscle by decreasing the plasma corticosterone concentration in chicks.

Effect of heat exposure on uncoupling protein-3 mRNA abundance in porcine skeletal muscle

Exposure to cold increases abundance of mRNA for uncoupling protein-3 (UCP3) in skeletal muscle, whereas the influence of exposure to heat is unknown. Thus, we conducted a study to investigate the influence of heat exposure on UCP3 mRNA abundance in porcine skeletal muscle. Three pigs aged 110 to 120 d, with an average BW of 75 kg, from each of eight litters were used. Each littermate was assigned to one of three treatment groups; one group was reared at 32 degrees C and fed ad libitum (32AL) for 4 wk, whereas the other two groups were maintained at 23 degrees C for the same period, and either pair-fed the intake of their 32AL littermates (23PF), or fed ad libitum (23AL). The RNase protection assay revealed that UCP3 mRNA abundance in longissimus dorsi and rhomboideus muscles was higher (P < 0.05) in the 32AL group than the 23PF group. The 23AL group also had significantly higher UCP3 mRNA abundance than the 23PF group in these muscles. Plasma total 3,5,3'-triiodothyronine concentration of the 32AL group was lower (P < 0.05) than that of the 23PF group, whereas mRNA abundance of thyroid hormone receptor (TR) isoforms, TRalpha1 and TRalpha2, in these muscles was not affected, suggesting that the 32AL group was in a relatively hypo-thyroid state. Because thyroid hormone up-regulates UCP3 expression, these results indicate that factors other than thyroid hormone may play a role in regulating UCP3 mRNA abundance in skeletal muscle of heat-exposed pigs.

Effects of human recombinant calcitonin on a rat osteopenia model induced by TPTX and arotinoid

Recombinant human calcitonin (rh-CT) has been developed as an agent for patients with excessive bone resorption to replace calcitonins from animal species, which are associated with tolerance problems. In this study, inhibitory effects of rh-CT against bone resorption were examined in thyroparathyroidectomized (TPTX) rats, the animal model of accelerated bone resorption induced by administering a synthetic retinoid (arotinoid). The arotinoid-treated TPTX rats exhibited signs of stimulated bone resorption, such as hypercalcemia, reduced bone mineral density, and inferior bone strength. Significant improvements were seen in all of these changes after a daily treatment with rh-CT (30, 300 U/kg s.c.) for 1 week. A histomorphometrical analysis showed that the treatment with rh-CT markedly suppressed the reduction of trabecular bone volume and that of cortical thickness in the femur of arotinoid-treated TPTX rats. These results suggest that rh-CT may prevent osteopenia caused by accelerated bone resorption.

Nutrition-hormone receptor-gene interactions: implications for development and disease

Nutrition profoundly alters the phenotypic expression of a given genotype, particularly during fetal and postnatal development. Many hormones act as nutritional signals and their receptors play a key role in mediating the effects of nutrition on numerous genes involved in differentiation, growth and metabolism. Polypeptide hormones act on membrane-bound receptors to trigger gene transcription via complex intracellular signalling pathways. By contrast, nuclear receptors for lipid-soluble molecules such as glucocorticoids (GC) and thyroid hormones (TH) directly regulate transcription via DNA binding and chromatin remodelling. Nuclear hormone receptors are members of a large superfamily of transcriptional regulators with the ability to activate or repress many genes involved in development and disease. Nutrition influences not only hormone synthesis and metabolism but also hormone receptors, and regulation is mediated either by specific nutrients or by energy status. Recent studies on the role of early environment on development have implicated GC and their receptors in the programming of adult disease. Intrauterine growth restriction and postnatal undernutrition also induce striking differences in TH-receptor isoforms in functionally-distinct muscles, with critical implications for gene transcription of myosin isoforms. glucose transporters, uncoupling proteins and cation pumps. Such findings highlight a mechanism by which nutritional status can influence normal development, and modify nutrient utilization. thermogenesis. peripheral sensitivity to insulin and optimal cardiac function. Diet and stage of development will also influence the transcriptional activity of drugs acting as ligands for nuclear receptors. Potential interactions between nuclear receptors, including those for retinoic acid and vitamin D, should not be overlooked in intervention programmes using I or vitamin A supplementation of young and adult human populations

Gelatin potentiates lead toxicity due to improper preparation of a Chinese tea drug, choreito. A study based on our previously published case report of long-term choreito use

A woman who had used a Chinese tea drug, choreito, for treatment of chronic renal diseases over years, experienced lead poisoning with blood lead concentration over 600 μg/l on admission to the hospital. We found that one of the ingredients in choreito, kasseki, was commonly contaminated by lead (30-50 μg/g of kasseki), but this level of lead contamination in the drug had never caused poisoning previously. Our experiment indicates that another ingredient, gelatin, has lead-extracting ability and an adhesive quality on the walls of teapots. Thus, the possible causes of the toxicity seemed to be: (1) the lead in the kasseki, which was extracted by gelatin that had adhered to the wall of the pot, accumulated in large quantities for a long period of time (the patient used the same pot for more than a year without washing); and (2) a large quantity of the accumulated lead was released into the decoted drug day by day and induced the intoxication. In all, 37.2 mg of lead was extracted by 10 extractions of 4% acetic acid from the patient's pot. Repeated extraction (four times) of lead from the pot which was made by the same manufacturer in the same lot of the patient's pot with acetic acid, only totally 18.5 μg of lead was detected.Also, it is evident that the intoxication was due to an improper method of decoction, that is, the patient did not prepare the tea according to Japanese pharmsacopoedia. The patient decocted all of the ingredients at the same time.

[A study of metallic mercury polluting a room after being spilled from a sphygmomanometer]

Mercury spilled from a mercurial sphygmomanometer on a hot carpet can vaporize and pollute the environment. We observed the vaporization of mercury in model experiments. Mercury (0.15g) was heated on a hot carpet and the near-by air was sampled with a midget impinger. The evaporated mercury levels were 5.0, 6.3, 8.1 and 10.0mg/m(3) at 20, 40, 60 and 80 minutes, respectively at a height of 30cm from carpet. The result indicated that even if a small quantity of mercury remained on the hot carpet, it could evaporate and pollute the indoor air. Little is known about the influence on human health of low mercury exposure, especially on children. In order not to pollute the air, we need to pay attention to mercury.

Growth hormone receptor gene expression in porcine skeletal and cardiac muscles is selectively regulated by postnatal undernutrition

During mild postnatal undernutrition, growth hormone receptor (GHR) mRNA abundance decreases in liver but increases in longissimus dorsi muscle. We tested the following hypotheses: 1) GHR gene expression is related to the metabolic and contractile characteristics of different muscles, and 2) the GHR response to nutrition depends on muscle type. Eight pairs of littermate pigs were weaned at 3 wk and given an optimal [60 g/(kg.d)] or low [(20 g/(kg.d)] food intake for the next 3 wk. All pigs grew, but at a slower rate in the low food intake group (P: < 0.001). Functionally distinct muscles were assessed for GHR mRNA (RNase protection analysis), oxidative myofibers (succinate dehydrogenase histochemistry) and type I slow myofibers (myosin immunocytochemistry). There were striking muscle-specific differences in GHR gene expression (P: < 0.001) and in its regulation by nutritional status. Relative expression of GHR mRNA in the optimal food intake group occurred in ascending order as follows: longissimus < diaphragm approximately rhomboideus < cardiac < soleus. There was a positive correlation with the proportion of oxidative myofibers (P: < 0.001) but not with type I myofibers (P: > 0.10). Compared with the high intake pigs, hepatic GHR mRNA was downregulated in the low intake pigs by 59% (P: < 0.01), whereas in the four muscles examined it was upregulated as follows: longissimus, 124% (P: < 0.05); rhomboideus, 19% (P: > 0.4); soleus, 65% (P: < 0. 05); cardiac, 51% (P: < 0.05). Moreover, the proportion of skeletal muscle fibers with high oxidative capacity was also greater in the low intake group (P: < 0.05). We conclude that postnatal GHR gene expression and its regulation by mild undernutrition are related to the metabolic, contractile and specific functional properties of different muscles.

Impaired Ca/calcineurin pathway in in vivo anergized CD4 T cells

Clonal anergy is one of the mechanisms that may account for self tolerance induced in T cells in the periphery. In this study we used the well-documented system of in vivo administration of a superantigen, staphylococcal enterotoxin B (SEB), to induce a state of hyporesponsiveness (anergy) in murine peripheral T cells to decipher the intracellular biochemical basis for this process. The TCR-induced Ca response of in vitro activated T cells was found to be impaired with significant defects in the phosphorylation of phospholipase C-gamma 1. Experiments with calcium ionophore and newly established transgenic mouse lines that express an active form of calcineurin suggested that in vivo SEB-induced anergy is established and/or maintained by a selective impairment in the TCR-induced activation of the Ca/calcineurin pathway.

Suboptimal energy balance selectively up-regulates muscle GLUT gene expression but reduces insulin-dependent glucose uptake during postnatal development

The major facilitative glucose transporters in muscle, GLUT1 (insulin-independent) and GLUT4 (insulin-dependent), are essential for normal growth and metabolism, but factors controlling their expression during postnatal development are poorly understood. We have therefore determined the role of energy status in regulating muscle GLUT gene expression and function in young, growing pigs on a high (H) or low (L) food intake (H =2L) at 35 degrees C or 26 degrees C. RNase protection assays revealed selective up-regulation of GLUT1 and GLUT4 by mild undernutrition 20-24 h after feeding: mRNA levels were elevated in longissimus dorsi (P<0.001) and rhomboideus (P<0.05), but not in diaphragm or cardiac muscles. Assessment of 2-deoxy-glucose uptake in a small isolated muscle, flexor carpi radialis, showed that the 26L group, which had suboptimal energy balance and the greatest GLUT4 expression, had the highest insulin-independent glucose uptake but the lowest insulin-dependent increment: 20% compared with 70% in the other groups. These novel findings are directly relevant to an understanding of mechanisms underlying the development of insulin resistance and demonstrate 1) muscle-specific up-regulation of GLUT gene expression by postnatal undernutrition that is not related simply to myofiber type, but to whole-body function; and 2) that the degree of GLUT up-regulation and the subcellular distribution and function of GLUT proteins are dependent on energy status.

Two novel oleanolic acid saponins having a sialyl Lewis X mimetic structure from Achyranthes fauriei root

Two novel triterpene glycosides, achyranthosides E and F, were isolated as methyl esters from the root of Achyranthes fauriei, an antiinflammatory medicinal plant. Their structures were characterized as oleanolic acid glucuronides having unique substituents composed of C6H9O5 and C9H15O7, respectively, at the C-3 position of glucuronic acid. These compounds are active components which can inhibit the excess recruiting of neutrophiles to injured tissues 1,000 times more potently than sialyl Lewis X.

Biological monitoring of metabolites of sarin and its by-products in human urine samples

More than 20,000 passengers of Tokyo underground trains were intoxicated with warfare toxic chemicals. Most of the patients examined had marked miosis and decreased serum cholinesterase activity. Transient increase of serum CPK activity after 3 days of the exposure was the another sign. We intensively analyzed the metabolites in the urine of 4 patients. The following analytic results indicated the exposure to sarin as well as contaminated compounds such as diisopropyl methylphosphonate (DIMP), ethyl methylphosphonate fluoridate (EMPF, or ethylsarin), diethyl methylphosphonate (DEMP), and ethyl isopropyl methylphosphonate (EIMP). (1) Isopropanol (IPA) and ethanol (EtOH) were detected of large quantities in the urine samples, and were thought to be derived from sarin and the sarin counterpart, EMPF, DIMP, DEMP and EIMP. (2) Monoalkyl methylphosphonic acids (isopropyl methylphosphonic acid (IMPA) and ethyl methylphosphonic acid (EMPA) also were excreted in large amounts with taking the similar excretion pattern of IPA and EtOH. (3) The metabolite only derived from sarin and ethylsarin is F anions whose integral output in the urine was less than the equimolar level of the excreted (IMPA + EMPA + IPA + EtOH). (4) Other corroborative findings were low lethality: of more than 5,510 patients treated, 11 were acutely dead. (5) Nine exposed males had higher sister chromatid exchange (SCE) rate (5.00 +/- 1.48/cell) than the control (3.81 +/- 0.697/cell), because dialkyl methylphosphonates seemed to have alkylating activity and producing DNA adducts. The SCE rate also increased after the in vitro exposure of lymphocytes to dialkyl methylphosphonates.

Method for the analysis of the methylphosphonic acid metabolites of sarin and its ethanol-substituted analogue in urine as applied to the victims of the Tokyo sarin disaster

An analysis method for the methylphosphonic acid metabolites of sarin in urine using trimethylsilyl derivatization and flame photometric detection is described in this report. Authentic reference standards of isopropyl methylphosphonic acid (IMPA) and ethyl methylphosphonic acid (EMPA) as well as methylphosphonic acid were employed to estimate the concentration in human urine. A sample pretreatment procedure was developed for urine using a column of cation-loaded ion-exchange resins (Ag+ -, Ba2+ - or H+ -Dowex) and adjusting the pH of the eluate from the column to 3.75-3.85 improved recovery of the target compounds. The eluate was evaporated to dryness under vacuum prior to trimethylsilylation, to remove water and any hydroxy- or amino-carrying volatile substances. The sarin metabolites, because of their low volatility, were concentrated and could be derivatized for analysis. The use of synthesized authentic sarin and ethylsarin metabolites, i.e., IMPA and EMPA, made it possible to establish the necessary sample pretreatment procedures for derivatization and gas chromatography-flame photometric detection (GC-FPD) analysis. The detection limits were 0.025 ppm both for EMPA and [MPA, and 0.625 microM for MPA, respectively. This method can be useful for estimating the exposure level to sarin by assaying the metabolites in urine and it is applicable to a large numbers of samples.

Murine thioredoxin peroxidase delays neuronal apoptosis and is expressed in areas of the brain most susceptible to hypoxic and ischemic injury

Thioredoxin peroxidase (TPx) is an antioxidant protein that limits the activity of reactive oxygen species (ROS). We cloned the cDNA encoding the mouse homolog of TPx from an E14.5 brain cDNA library and analyzed its distribution and function in murine tissues. Comparison of the amino acid sequence of mouse TPx with those of other species revealed that TPx was highly conserved across all species. Mouse TPx had broad tissue distribution, but its expression was especially marked in cells that metabolize oxygen molecules at high levels such as erythroid cells, renal tubular cells, cardiac and skeletal muscle cells, and certain types of neurons. Levels of increased expression of TPx in the brain were coincident with regions known to be especially sensitive to hypoxic and ischemic injury in humans. Models of erythroid differentiation and neuronal survival were employed to study the function of TPx. Murine erythroleukemia cells (MEL cells) increased TPx transcription when in a chemically differentiated state. Furthermore, expression of mouse TPx in PC12 pheochromocytoma cells prolonged their survival in the absence of nerve growth factor (NGF) and serum, indicating that TPx could promote neuronal cell survival. We propose that TPx contributes to antioxidant defense in erythrocytes and neuronal cells by limiting the destructive capacity of oxygen radicals. These findings identify a novel gene that appears to be relevant to hypoxic brain injury and may be of importance in development of new approaches to abrogate the effects of ischemic- and hypoxic-related injury in the central nervous system (CNS).

Comparative sequence analyses of the genes coding for 16S rRNA of Lactobacillus casei-related taxa

The primary structures of the 16S rRNA genes of the type strains of Lactobacillus casei and related taxa were determined by PCR DNA-sequencing methods. The sequences of Lactobacillus casei, Lactobacillus zeae, Lactobacillus paracasei, and Lactobacillus rhamnosus were different. The Knuc values ranged from 0.0040 to 0.0126. On the basis of the Knuc values and the levels of DNA-DNA relatedness among the strains of these species, the L. casei-related taxa should be classified in the following three species: L. zeae, which includes the type strains of L. zeae and L. casei; a species that includes the strains of L. paracasei and L. casei ATCC 334; and L. rhamnosus.

Herbal medicine-associated lead intoxication

A female patient visited our hospital with abdominal pain and anemia. Examination for a gastrointestinal disease gave no diagnostic information. Laboratory studies of the parameters of heme biosynthesis revealed an enzymatic inhibition by lead. The diagnosis of lead poisoning was confirmed by detection of an elevated blood lead level. Excessive lead ingestion was thought to be caused by herbal medicines and/or by an earthen teapot.

bcl-2 alters the antigen-driven selection of B cells in mukappa but not in mu-only Xid transgenic mice

A point mutation in the pleckstrin homology domain of the mouse Bruton's tyrosine kinase (btk) gene results in an X-linked immune defect, Xid, characterized by immunologic unresponsiveness to polymeric carbohydrate Ags. In Xid mice, B cells specific for phosphocholine (PC) do not develop in peripheral lymphoid tissues because they either fail to be positively selected from the marrow or they are clonally deleted via an Ag-driven, receptor-mediated process. Overexpression of the bcl-2 gene allows PC-specific B cells to survive and mature in Xid mukappa anti-PC transgenic mice, but PC-specific B cells are not rescued by bcl-2 in Xid mu-only transgenic mice. The failure of bcl-2 to rescue PC-specific B cells, in mu-only transgenic mice suggests that either it does not correct the btk defect in the Ag-driven selection process that occurs in pre-B cells and/or in very immature B cells or that a btk-dependent proliferative phase is required for the selection and amplification of the PC-specific B cells in mu-only transgenic mice. The rescue of PC-specific B cells in mukappa transgenic mice indicates that bcl-2 can alter receptor-mediated B cell selection at late stages in B cell development. The rescued PC-specific B cells in Xid male mice do not exhibit an altered proliferation profile in response to B cell-stimulating agents compared with B cells from unmanipulated Xid mice; thus, they fail to respond to soluble anti-mu, or PC-dextran, but they proliferate in response to PC, anti-mu, or anti-id conjugated to Sepharose.

bcl-2 alters the antigen-driven selection of B cells in mukappa but not in mu-only Xid transgenic mice

A point mutation in the pleckstrin homology domain of the mouse Bruton's tyrosine kinase (btk) gene results in an X-linked immune defect, Xid, characterized by immunologic unresponsiveness to polymeric carbohydrate Ags. In Xid mice, B cells specific for phosphocholine (PC) do not develop in peripheral lymphoid tissues because they either fail to be positively selected from the marrow or they are clonally deleted via an Ag-driven, receptor-mediated process. Overexpression of the bcl-2 gene allows PC-specific B cells to survive and mature in Xid mukappa anti-PC transgenic mice, but PC-specific B cells are not rescued by bcl-2 in Xid mu-only transgenic mice. The failure of bcl-2 to rescue PC-specific B cells, in mu-only transgenic mice suggests that either it does not correct the btk defect in the Ag-driven selection process that occurs in pre-B cells and/or in very immature B cells or that a btk-dependent proliferative phase is required for the selection and amplification of the PC-specific B cells in mu-only transgenic mice. The rescue of PC-specific B cells in mukappa transgenic mice indicates that bcl-2 can alter receptor-mediated B cell selection at late stages in B cell development. The rescued PC-specific B cells in Xid male mice do not exhibit an altered proliferation profile in response to B cell-stimulating agents compared with B cells from unmanipulated Xid mice; thus, they fail to respond to soluble anti-mu, or PC-dextran, but they proliferate in response to PC, anti-mu, or anti-id conjugated to Sepharose.

TCR-beta transgenic mice fail to mediate a GVHR due to defects of allorecognition and subsequent IL-2 generation

All T cells of TCR-beta transgenic mice bear a single TCR-beta chain and consequently the diversity of the TCR may be reduced by as much as one million-fold. Despite this limited diversity, many measures of lymphocyte function in these mice are normal. We have previously demonstrated that lymphoid cells from TCR-beta mice are unable to mediate an intense graft-versus-host response (GVHR). In order to investigate the mechanism of this hyporesponsiveness, we studied in vivo allorecognition in diverse strains of TCR-beta mice. All tested strains of TCR-beta mice failed to mediate a substantial GVHR across multiple H-2 barriers. In addition, mixtures of cells from several strains of TCR-beta mice only generated mild GVHRs. Sensitive tests of in vitro allorecognition show that lymphoid cells from TCR-beta mice respond less vigorously to alloantigen as measured both by decreased proliferation and decreased IL-2 production in a MLR. In addition, cells from TCR-beta mice fail to use exogenous IL-2 appropriately in their response to alloantigen. We conclude that the fixed TCR-beta chain causes a defective response to alloantigen, which is measured as decreased IL-2 generation and utilization, and that this abnormality results in a decreased GVHR.

Inhibition of apoptosis and augmentation of lymphoproliferation in bcl-2 transgenic Fas/Fas ligand-defective mice

Mice defective in Fas (CD95 or APO-1) or its ligand (lpr or gld mice) develop age-dependent lymphadenopathy and systemic autoimmune disease. T cells accumulating in the lymph nodes of these mice express reduced levels of Bcl-2 protein and are susceptible to spontaneous and glucocorticoid-induced apoptosis. We backcrossed bcl-2 transgenic mice to lpr and gld mice to homozygosity to determine the effects of Bcl-2 overexpression. T cells in these mice were resistant to spontaneous and glucocorticoid-induced apoptosis in vitro. Moreover, the accumulation of CD4(-)CD8(-) T cells in the lymph nodes and the spleens was augmented, suggesting that a Bcl-2-dependent mechanism regulating the number of T cells residing in the peripheral lymphoid organs in addition to the Fas-mediated pathway exists.

Moloney murine leukemia virus infection accelerates lymphomagenesis in E mu-bcl-2 transgenic mice

E mu-bcl-2 transgenic mice bearing the bcl-2 proto-oncogene linked to the immunoglobulin enhancer (E mu) sporadically develop B or T cell lymphomas after a long latent period. To identify genes that play important roles in development of lymphoid malignancies, proviral insertional mutagenesis with Moloney murine leukemia virus (MMuLV) was carried out in two lines of transgenic mice expressing the bcl-2 gene primarily in B or T cells. MMuLV infection of non-transgenic mice induced primarily mature T cell lymphomas. By contrast, infection of newborn E mu-blc-2 mice with the virus accelerated lymphomagenesis, and nearly all of the mice eventually succumbed to clonal pre-B, B, or mainly immature T cell lymphoma, indicating the active contribution of the bcl-2 gene in lymphomagenesis. Southern blot analysis of tumor DNA from MMuLV-infected transgenic mice revealed a proviral insertion at the c-myc gene in 26% (9/35) of tumors, at the pim-1 gene in 6% (2/35) and at the pim-2 (recently renamed tic-1) gene in 23% (8/35). Some tumors carried two activated oncogenes. No insertion was detected at the bmi-1 gene. These data suggest the usefulness of this transgenic system for analysis of lymphomagenesis involving the activated bcl-2 gene.

Variation of urinary pH and bicarbonate concentrations of students in metropolitan and rural areas of Japan

Changes in urinary pH and bicarbonate levels were studied in urine collected before and after final examinations taken by 91 medical students (65 males, 26 females) in Tokyo and from 87 students (73 males, 14 females) in Kanazawa, a rural municipality. Bicarbonate levels and pH in the urine of students in both cities increased significantly after attending 2 h of final examinations. The highest pH value and highest bicarbonate level were 7.66 and 80.3 mM, respectively, found in the urine of a student in Kanazawa. Urinary pH and bicarbonate levels averaged 6.48 and 11.1 mM, respectively, for students in Tokyo and 6.26 and 8.91 mM, respectively, for students in Kanazawa. Given that the concentrations of carbon dioxide in the air of the classrooms in both cities increased drastically during the final examinations (i.e., from 700 ppm to 1 200 ppm in Tokyo and from 700 ppm to 1 500 ppm in Kanazawa), it appears that the increases in urinary pH and bicarbonate levels were correlated with the increase of carbon dioxide (known to be convertible to bicarbonate in blood) in the rooms. This was also supported by the increase in urinary pH and bicarbonate levels found in urine collected from 20 students who stayed in a cinema for 3 h, at which location carbon dioxide levels in air reached 1 200 ppm.

Prevention of breast tumour development in vivo by downregulation of the p185neu receptor

Certain strains of transgenic mice that express the rat neu oncogene (neuT) in mammary epithelial cells develop breast tumours at an average of 44 weeks of age. In this study, intraperitoneal injection of a monoclonal anti-receptor antibody specific for the rat neuT oncogene product dramatically affected tumour development in these transgenic mice in a dose-dependent manner. A significant proportion (50%) of mice, when injected with anti-receptor antibodies, did not develop tumours even after 90 weeks of age. The phosphotyrosine levels of the membrane fraction of breast tissues in the anti-receptor antibody-treated mice were almost completely abolished when a higher dose of antibodies was used. This study demonstrates, for the first time, that immunologic manipulation of an oncogene product can effectively prevent the development of tumours in a rodent transgenic model.