Protective effect of a novel vitamin E derivative on experimental traumatic brain edema in rats--preliminary study

Oxygen free radicals have been proposed to be one of the major mechanisms of secondary brain damage in traumatic brain injury. Protective effect by vitamin E against oxidative damage has attracted much attention. Recent studies have demonstrated a novel vitamin E derivative, 2-(alpha-D-glucopyranosyl)methyl-2,5,7,8-tetramethylchroman-6-ol (TMG), has excellent water-solubility and antioxidant activity. The purpose of this study was to investigate protective effects of TMG on experimental traumatic brain edema (BE). Male Wistar rats were anaesthetized with chloral hydrate. Traumatic BE was produced by a cortical freezing lesion. Animals were separated into three groups: saline-treated rats (n = 4), TMG-treated (4 mg/kg) rats (n = 7) and TMG-treated (40 mg/kg) rats (n = 8). Saline or TMG was administered intravenously before lesion production. Animals were sacrificed at 6 hours after lesion production and the brain water content was determined by the dry-wet weight method. Half-life of TMG after intravenous administration of TMG was also investigated. The half life of TMG was approximately 5 minutes. TMG (40 mg/kg) significantly attenuated BE following cryogenic brain injury (p < 0.01). In conclusion, this preliminary study has demonstrated that a novel vitamin E derivative might be promising in the treatment of traumatic BE.

In vivo radioprotection by alpha-TMG: preliminary studies

alpha-TMG is a novel water-soluble derivative of Vitamin E that has shown excellent antioxidant activity. The parent compound has demonstrated protection against radiation induced chromosomal damage in vivo. Hence, the preliminary experiments to determine the radioprotective activity of alpha-TMG were carried out in adult Swiss albino mice. Acute toxicity of the drug was studied taking 24h, 72 h and 30 day mortality after a single intraperitoneal injection of 500-2000 mg/kg body weight of the drug. The drug LD(50) for 24h and 72 h/30 day survival were found to be 1120 and 1000 mg/kg body weight, respectively. The optimum time of drug administration and drug dose-dependent effect on in vivo radiation protection of bone marrow chromosomes was studied in mice. Injection of 600 mg/kg of the drug 15 min before or within 5, 15 or 30min after 3Gy whole body gamma radiation resulted in a significant decrease in the aberrant metaphases percent at 24h post-irradiation; the maximum effect was seen when the drug was given immediately after irradiation. Injection of 200-800 mg/kg TMG within 5 min of irradiation with 3 Gy produced a significant dose-dependent reduction in the radiation induced percent aberrant metaphases and in the frequency of micronucleated erythrocytes at 24h after exposure, with a corresponding decrease in the different types of aberrations. The optimum dose for protection without drug toxicity was 600 mg/kg body weight. At this dose, TMG produced 70 and >60% reduction in the radiation induced percent aberrant metaphases and micronucleated erythrocytes, respectively. The high water solubility and effectiveness when administered post-irradiation favor TMG as a likely candidate for protection in case of accidental exposures.

Intraocular pressure-lowering efficacy of latanoprost in patients with normal-tension glaucoma or primary open-angle glaucoma

We investigated the intraocular pressure (IOP)-lowering potential of latanoprost in patients with normal-tension glaucoma (NTG) or primary open-angle glaucoma (POAG). This prospective study included 59 NTG and 20 POAG patients treated with the following four dosing regimens of latanoprost: patients on no previous medication received latanoprost as initial therapy (Group 1, n=31), patients on beta-blocker therapy received latanoprost as adjunctive therapy (Group II, n=9), patients on unoprostone monotherapy were switched to latanoprost monotherapy (Group III, n=14), and patients previously on dual therapy with isopropyl unoprostone and beta-blocker were switched to a combined treatment of latanoprost and beta-blocker (Group IV, n=25). IOP significantly decreased 8 weeks after initiation of latanoprost therapy by 19.9% in Group I, 20.5% in Group II, 16.6% in Group III, and 12.2% in Group IV. In Groups I and II, there was a significant positive correlation between the magnitude of IOP reduction induced by latanoprost and the IOP level before latanoprost therapy. The IOP level before latanoprost therapy is a contributing factor in the IOP-lowering efficacy of latanoprost. Latanoprost is more effective in lowering IOP than isopropyl unoprostone.

Analysis of the addition products of alpha-tocopherol with phosphatidylcholine-peroxyl radicals by high-performance liquid chromatography with chemiluminescent detection

A chemiluminescence-based high-performance liquid chromatographic method was developed for the analysis of the addition products of alpha-tocopherol with phosphatidylcholine-peroxyl radicals (TOO-PC). The TOO-PC eluted from a reversed-phase column was reacted with a chemiluminescent reagent consisting of a Cypridina luciferin analog and a lipid-soluble iron chelate in acidic methanol at 50 degrees C, and the generated chemiluminescence was monitored. The detection limit for TOO-PC by this method was about 1 pmol. This method was applied to the detection of TOO-PC in the peroxidized membranes prepared from rabbit erythrocyte ghosts. When the erythrocyte ghosts were peroxidized by the addition of a water-soluble free radical initiator, a peak corresponding to TOO-PC was detected on the chromatogram with chemiluminescent detection. The amount of TOO-PC in the erythrocyte membranes increased with the depletion of endogenous alpha-tocopherol. The results indicate that this method proved useful for the detection of the TOO-PC formed by the peroxyl-radical scavenging reactions of alpha-tocopherol in biological systems.

Helicobacter pylori water extract induces interleukin-8 production by gastric epithelial cells

In Helicobacter pylori-associated gastric mucosal injury, interleukin (IL) -8, a potent leukocyte chemoattractant, is produced by epithelial cells infected by H. pylori and directs neutrophils to the gastric mucosa. According to previous studies, the IL-8 production requires direct contact between the bacteria and epithelial cells. The aims of the present study were to determine whether an H. pylori water extract (HPE) induces IL-8 production by gastric epithelial cells and to characterize IL-8-inducing substances in HPE. Extracts were prepared from a standard strain and from strains obtained from patients with gastric ulcers. After addition of HPE to MKN 45 cells, a gastric cancer cell line, IL-8 in supernatants and IL-8 mRNA were measured by immunoassay and reverse transcription-polymerase chain reaction, respectively. For characterization, active fractions obtained by gel filtration of standard-strain HPE were treated by heating or trypsinization. To study the signal pathway leading to IL-8 production, inhibitors for protein kinase A (PKA), protein kinase C (PKC), or protein tyrosine kinase (PTK) were incubated with MKN45 cells before HPE stimulation. HPE from the standard strain and one of these clinical strains induced IL-8 production. Lipopolysaccharide or cagA in the strains showed no correlation with IL-8 concentration. Standard-strain HPE induced IL-8 mRNA expression in MKN 45 cells. Gel filtration localized activity to a low-molecular-weight fraction of about 7 kDa, which was resistant to heat and trypsin digestion. PKC inhibitors significantly blocked HPE-induced IL-8 production by MKN 45 cells; however, the PKA inhibitor or PTK inhibitors showed a partial inhibitory effect. HPE contains a nonprotein substance of low molecular weight that is responsible for IL-8 induction in gastric epithelial cells. This induction is mainly dependent on the activation of PKC but partially also dependent on PKA or PTK.

A novel water-soluble vitamin E derivative protects against experimental colitis in rats

This study was designed to investigate the effects of water-soluble vitamin E derivative, 2-(alpha-D-glucopyranosyl)methyl-2,5,7,8-tetramethylchroman-6-ol (TMG), on experimental colitis in rats. Colitis was induced in male Wistar rats weighing 200 grams using an enema of trinitrobenzene sulfonic acid (TNBS) dissolved in 50% ethanol; 1 ml of TMG dissolved in physiological saline (0.2 mg/ml, 2 mg/ml, 20 mg/ml) was injected intraperitoneally every day for 1 week after the enema. The damage score, wet weight of the colon, and increase in body weight were estimated 1 week after the enema of TNBS. Thiobarbituric acid-reactive substances (TBA-RS), an index of lipid peroxidation, and the level of alpha-tocopherol or TMG in the colonic mucosa were measured 1 week after the induction of colitis. As a result, increase in body weight was inhibited by the induction of colitis, although the inhibition was reduced in the group treated with TMG. The damage score, wet weight and TBA-RS were increased significantly in the colitis group; however, they were inhibited by the administration of TMG. The alpha-tocopherol level in the colonic mucosa was reduced by the induction of colitis, wheres TMG could not be detected in the colonic mucosa of rats treated with TMG. These results suggest that TMG is effective for the treatment of colitis in rats induced by TNBS.

Ytterbium-decreasing Streptomyces sp. and its naphthoquinone-pigment production in the presence of rare-earth elements

We screened for oligotrophic microorganisms capable of decreasing the concentration of ytterbium (Yb), a representative of the heavy rare-earth elements, in a culture medium. From 476 strains of oligotrophic microorganisms (grown on 1/100 diluted nutrient agar) isolated from soil and river water samples, 5 strains capable of reducing the concentration of Yb in diluted nutrient broth containing 5 ppm Yb were selected. Among them, a strain capable of reducing the concentration of all rare-earth elements to a great extent was identified as Streptomyces sp. (strain YB-1). This strain produced redish-purple pigment(s) only in the presence of rare earths, but not in that of other metals. The pigment was extracted with ethyl acetate and purified by a series of column chromatography steps. From the results of structural analysis using ultraviolet or infrared absorption spectrometry and 13C-NMR, the pigment was determined to be a kind of naphthoquinone similar to nanaomycin produced by a Streptomyces sp. These results suggested that rare earths might affect the physiological activity of this strain.

In vivo and in vitro effects of AVP and V1a receptor antagonist on Cushing's syndrome due to ACTH-independent bilateral macronodular adrenocortical hyperplasia

We examined the possibility that AVP and V1a receptors were involved in regulating cortisol production in a 49 year old man with ACTH-independent bilateral macronodular adrenocortical hyperplasia (AIMAH), and investigated the effects of a V1a receptor antagonist. An i.v. injection of a small dose (0.1 or 0.3 U) of AVP, insulin-induced hypoglycaemia, upright posture tests, and oral administration of a V1a receptor antagonist (OPC-21268; 300 mg), and its repeated administration at a dose of 600 mg/day for 8 days were performed. An in vitro study of dispersed cells obtained from resected AIMAH tissue was also conducted. Plasma ACTH, AVP and cortisol levels and 24-h urinary free cortisol excretion were measured in the in vivo studies and cortisol concentrations in incubation media in the in vitro study. Injection of small doses of AVP stimulated cortisol secretion without any elevation of plasma ACTH. Insulin-induced hypoglycaemia caused a rise in plasma AVP followed by an increase in plasma cortisol. Although plasma cortisol levels were not affected by single or repeated administrations of OPC-21268, 24-h urinary free cortisol excretion was significantly decreased by the repeated treatment. In the in vitro study, more cortisol was stimulated by AVP from adrenal cells of the AIMAH tissue than from those of a normal adrenal gland, and this secretion was completely suppressed by OPC-21268. These results suggested that hypersensitivity to AVP may have contributed to overproduction of cortisol in this case of ACTH-independent bilateral macronodular adrenocortical hyperplasia, and may have contributed to its pathogenesis.

Antioxidant activity of a novel vitamin E derivative, 2-(alpha-D glucopyranosyl)methyl-2,5,7,8-tetramethylchroman-6-ol

A novel vitamin E derivative, 2-(alpha-D-glucopyranosyl)methyl-2,5,7,8-tetramethylchroman-6-ol (TMG), has excellent water-solubility (> 1 x 10[3] mg/ml). The antioxidant activity of TMG was investigated. Kinetic studies of the inhibition of radical-chain reaction of methyl linoleate in solution demonstrated that the peroxyl radical-scavenging activity was not changed by the replacement of phytiyl side chain of vitamin E to glucosyl group. TMG acted as an effective inhibitor on lipid peroxidation of egg yolk phosphatidylcholine (PC)-liposomal suspension induced by a water-soluble and a lipid-soluble radical generator, 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) and 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN). Its effectiveness was higher than that of ascorbic acid (AsA) when liposomal suspension was exposed to a lipid-soluble radical generator, AMVN. TMG also showed an excellent antioxidant activity on cupric ion-induced lipid peroxidation of PC-liposomal suspension, and suppressed the oxidation of rat brain homogenate which contained trace level of iron ion. On the other hand, AsA acted as a prooxidant on both the cupric ion-induced liposomal peroxidation and the oxidation of rat brain homogenate. When human plasma was exposed to either AAPH or AMVN, the accumulation of cholesteryl ester hydroperoxides was retarded by the addition of TMG.

Effect of glucocorticoid receptor antagonist RU 38486 on acute glucocorticoid-induced insulin resistance in rat adipocytes

We examined the mechanism of acute glucocorticoid-induced insulin resistance in rat adipocytes using the glucocorticoid receptor antagonist RU 38486. Pretreatment with dexamethasone (DEX) and prednisolone for 60 minutes resulted in 50% inhibition of insulin-induced [3H]2-deoxyglucose (DOG) uptake at 10(-8) and 10(-7) mol/L, respectively, in rat adipocytes and 20% and 25% inhibition of insulin-induced [3H]2-DOG uptake, respectively, in soleus muscles. Our previous experiments indicated that DEX and prednisolone alone stimulate protein kinase C (PKC) in rat adipocytes. Accordingly, we examined [3H]DEX binding to PKC from MonoQ column-purified rat brain cytosol. Specific [3H]DEX binding to MonoQ column-purified PKC was observed (kd, 56.8 nmol/L; Bmax, 725 fmol/mg protein). Thus, insulin-induced PKC translocation from the cytosol to the membrane was suppressed by pretreatment with 10(-7) mol/L DEX and 10(-6) mol/L prednisolone for 80 minutes. During treatment with RU 38486 for 60 minutes, there was no change in the glucocorticoid-induced inhibitory effect on insulin-induced [3H]2-DOG uptake and PKC translocation from the cytosol to the membrane. Moreover, pretreatment with RU 38486 for 120 minutes slightly prevented the DEX-mediated inhibition of insulin-induced glucose uptake. These results suggest that acute glucocorticoid-induced insulin resistance may be mainly mediated through the other non-glucocorticoid receptor pathway.

Synthesis of a novel vitamin E derivative, 2-(alpha-D-glucopyranosyl) methyl-2,5,7,8-tetramethylchroman-6-ol, by alpha-glucosidase-catalyzed transglycosylation

A novel derivative of vitamin E, vitamin E glucoside, was synthesized from 2-hydroxymethyl-2,5,7,8-tetramethylchroman-6-ol and maltose in a solution containing DMSO by transglycosylation with alpha-glucosidase from Saccharomyces species. The glycosylated product was identified as 2-(alpha-D-glucopyranosyl)methyl-2,5,7,8-tetramethylchroman-6-ol (TMG) by mass spectrometry and nuclear magnetic resonance spectroscopy. The optimal pH of transglycosylation was 5.5, and the yield of TMG increased as the concentration of maltose increased. TMG has high solubility in water (> 1 x 10(3) mg/mL). The 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of TMG was found to be nearly the same as those of alpha-tocopherol, Trolox (2-carboxy-2,5,7,8-tetramethylchroman-6-ol), and ascorbic acid.

Design of an acclimation system capable of controlling carbon dioxide concentration

The production system for grafted seedlings mainly consists of three processes; 1) growth of seedlings, 2) grafting of seedlings, and 3) acclimation of grafted seedlings. Of the three processes, the duration of acclimation is highly influenced by the acclimation conditions. The acclimation environment after grafting was controlled to be satisfied the demands of grafted seedlings in the point of the physiological reaction such as photosynthesis, respiration, transpiration, and translocation nutrients. In the present study, a preliminary experiment was conducted to understand the relationship between the factors concerned with the acclimation of grafted seedlings, using a new acclimation apparatus. The factors of interest were air temperature, relative humidity, light, and carbon dioxide concentration. In the presence of light, the air temperature and relative humidity were interfered each other, so that both factors were difficult to keep at a constant value. Furthermore, the concentration of carbon dioxide was remarkably fluctuated by the relative humidity regulated by the humidifier and dehumidification which was controlled by the temperature differences between water and ambient air. A new device of acclimation system which is automatically controlled would be expected to construct in near future. Such a device will make it possible to shorten the duration of acclimation and produce high quality of grafted seedlings.

Development of centrifugal phytotron to study the gravity effect on vegetable plant growth

The present Spacetron is used to cultivate plants over a long term by controlling environment condition. The cultivation drum was rotated in perpendicular direction creating fluctuation in gravity. Centrifugal force plus 1 G ground gravity, are distributed unevenly over the cultivation drum. This fluctuation effect on plant growth was not clear. In the modified Spacetron the cultivation drum rotates horizontally whereas the plant stage rotated in the perpendicular direction. To find the basic information for design of centrifugal phytotron the two axes Spacetron Junior (clinostat) was developed to formulate the micro and hypergravity environment. It would be used to study the effect on a plant growth process of different gravity conditions. In order to produce the different values of gravity, the clinostat's axis was rotated with a stepping motor at different angular velocity. The axis rotated at 5.2 revolutions per minute (rpm) to create a centrifugal force equivalent to 0.01 G and the plant stage was rotated at 5.2 rpm. The chlorophyll value is higher in the plants under microgravity condition of 0.01 G whereas the fresh weight and dry weight are higher in the plants under control condition of 1 G earth gravity. The result of this study showed that the plant growth was affected by microgravity along with other known factors such as vibration and unknown factors.

Antinociceptive activity of deltorphin analogs in the formalin test

Two deltorphin (DLT: Tyr-D-Met-Phe-His-Leu-Met-Asp-NH2) analogs, [N alpha-n-butyl-Gly6]DLT ([nBuG6]DLT) and [N alpha-iso-butyl-Gly6]DLT ([isoBuG6]DLT), were examined for their antinociceptive activities by a formalin test in mice after subcutaneous (s.c.) injection. [nBuG6]DLT exhibited potent dose-dependent antinociceptive activities at doses of more than 0.02 mumol/kg at the first and second phases, while morphine similarly inhibited of the pain responses at doses more than 0.01 mumol/kg in the formalin test. [isoBuG6]DLT showed potent antinociceptive activity at the second phase, but did not inhibit the pain response at the first phase. This phenomenon may be caused by a mu-antagonist/delta-agonist property of this compound. The antinociceptive effects of these analogs were antagonized by delta-antagonist naltrindole, but not by the mu-antagonist naloxone. These findings suggest that the antinociceptive effects were mediated via delta-receptors. These compounds may be useful as delta-agonists for clarifying the mechanism of analgesia mediated by delta-opioid receptors.

Performance of a centrifugal phytotron

It is possible to cultivate plants under an artificial gravity field generated by a centrifugal device in space. In order to determine an optimal magnitude of gravity, there is a need to investigate the relationship between plant and growth and gravity, including not only reduced gravity but also gravity greater than 1G. A prototype centrifugal phytotron was designed and fabricated in order to investigate the relationship between plant growth and increased gravity. This device enables us to cultivate plants over the long term by controlling environmental conditions in the phytotron such as temperature, relative humidity, CO2 concentration and light intensity. The results of our experiment indicate that plant seeds can germinate and grow even under an artificial gravity which changes sinusoidally from 2G to 4G.

Manganese ions penetrate via L-type Ca2+ channels and induce contraction in high-K+ medium in ileal longitudinal muscle of guinea-pig

1. Mn2+ (5 mM) completely inhibited the K+ (10-60 mM)-induced ileal tonic tension to the baseline, however, the tension and Mn2+ uptake increased progressively, depending on the K+ concentration of above 35 mM. 2. The L-type Ca2+ channel blocker, D-600 and nifedipine inhibited the tension development and Mn2+ uptake after addition of Mn2+ in the high-K+ (60 mM) medium, however, T-type Ca2+ channel blocker, Ni2+ and amiloride had no effect on it. 3. D-600 and nifedipine inhibited the tension development and Mn2+ uptake in the presence of 5 mM Mn2+ in the Ca(2+)-free, high-K+ (60 mM) medium. 4. The results suggest that Mn2+ penetrates via L-type Ca2+ channels in the ileal cell membrane in a state of prolonged depolarization and activates the contractile elements.

[A case of Sjögren's syndrome with rheumatoid arthritis manifesting transverse myelitis with antineuronal antibody]

We report a sixty-year-old woman with transverse myelitis who had suffered from rheumatoid arthritis since age of 52. She was admitted to our department because of muscle weakness and painful tonic spasm in the bilateral lower extremities, sensory disturbance below the mamillary level and bladder disturbance. She had sicca symptoms. As a result of sialography, Sjögren's syndrome was diagnosed. Antineuronal antibody was found in the sera of the patient. She had no symptom of systemic vasculitis. Lupus anticoagulant and anticaldiolipin antibody were negative. The pathogenesis of transverse myelitis in rheumatic disease is still uncertain. Vasculitis and the immunological reaction of antineuronal antibody have been suggested as possible causes. This report suggests the influence of direct immunological reaction on the central nervous system.

Heterotransplantation of human parathyroid glands into nude mice

Heterotransplantation of human parathyroid tissues into nude mice was performed to investigate the characteristics of grafted tissues. Grafts prepared from hyperplasia, adenoma and normal glands which were resected at operation were implanted in the gluteus muscle of the recipient mice (female, KSNnu/nu strain). Graft function was evaluated by measuring human intact PTH concentrations in sera of the mice. Serum PTH concentrations 12 weeks after transplantation were correlated with the tissue volume in the mice which received one, two, four or eight pieces of 1 mm3 hyperplastic tissues. Changes in graft function were examined in the mice which received four grafts prepared from hyperplasia, adenoma or normal glands. Transplantation of parathyroid tissues resulted in an increase in PTH concentrations for 4 weeks, reaching a plateau thereafter. The level remained unchanged for 8 weeks. Serum PTH levels in the mice with grafts prepared from hyperplasia or adenoma were significantly higher than in those with grafts from normal glands, though without a significant difference between the mice with grafts from adenoma and from hyperplasia. Serum calcium levels were similar in all three groups. We also observed the response of grafted parathyroid tissue to a low calcium level in sera: there was higher PTH secretion four weeks after the administration of the low calcium diet. The success of heterotransplantation was histologically proven by the presence of grafts which were not atrophic in the muscle 12 weeks after transplantation. Nucleoli were found more frequently, and nuclear pleomorphism was observed in the cells of heterografts.