Effects of supplementation with higher levels of manganese and magnesium on immune function

The magnesium (Mg) and manganese (Mn) were evaluated for its effectiveness as an immunomodulator in rats. The treatments were as follows: Group 1, AIN-93M diet (0.05% Mg, 0.001% Mn); Group 2, high-dose Mg (0.1% Mg, 0.001% Mn); and Group 3, high dose Mn (0.05% Mg, 0.01% Mn) (n-12/group). After 12 weeks of supplementation, rats were sacrificed to assess the effect on a range of innate responses (tumoricidal activity, oxidative burst and nitric oxide) and the mitogen-stimulated lymphoproliferative response. Immune function was significantly affected in both the high dose Mg and the Mn group. Lymphocyte proliferative responses and NK cell activity were measured in pooled spleen from each group. The mitogen response of lymphocytes to LPS in the spleen was significantly reduced in high dose Mg-treated groups, whereas the response to ConA was not affected in both high dose minerals-treated groups. The reactive oxygen species level of macrophages was decreased in both groups. These effects were more pronounced in high dose Mg-treated group. Nitric oxide production was also decreased in high dose minerals-treated group. In addition, tumoricidal activities of splenic NK cell and peritoneal macrophage in mineral exposed rats were significantly increased. Moreover, percent death of macrophage was reduced in two groups receiving high dose mineral supplements. Taken together, the present data suggest that high dose trace min erals exert a differential effect on the function of immune cells.     

Orbital metastasis in patients with rhabdomyosarcoma: case series and review of the literature

We present 3 cases of children who developed recurrent rhabdomyosarcoma with metastases to the orbit and review the medical literature. Eight additional cases have previously been reported. Alveolar rhabdomyosarcoma was diagnosed in 7 cases. All 11 patients had stage 3 or 4 tumors at diagnosis, but none had orbital involvement initially. The mechanism of orbital recurrence is hematogenous in nature. Ten of the patients died; 7 of them succumbed with progressive disease within 6 months of the orbital recurrence.     

Cyclooxygenase 2 rescues LNCaP prostate cancer cells from sanguinarine-induced apoptosis by a mechanism involving inhibition of nitric oxide synthase activity

Expression of cyclooxygenase-2 (Cox-2), an inducible enzyme responsible for the production of prostaglandins from arachidonic acid, is elevated in human prostate tumor samples. The aim of this study was to investigate whether expression of Cox-2 is effective against prostate cancer cell apoptosis triggered by sanguinarine, the quaternary benzophenanthridine alkaloid with antineoplastic properties. Sanguinarine effectively induced apoptosis in LNCaP human prostate cancer epithelial cells as assessed by caspase-3 activation assay, Annexin V staining assay, or by visual analysis for the apoptotic morphology changes. Sanguinarine-mediated apoptosis was associated with the increase of nitric oxide (NO) formation in prostate cancer cells as assessed by measurements of nitrites with Sievers nitric oxide analyzer as well as flow cytometry analysis using NO fluorescent sensor. Activation of NO synthase (NOS) activity was crucial for sanguinarine-induced cell death because NOS inhibitor L-NMMA efficiently protected cells from apoptosis. Adenovirus-mediated transfer of Cox-2 into LNCaP cells inhibited sanguinarine-induced apoptosis and prevented an increase in NO production. Surprisingly, NO donors failed to induce apoptosis in LNCaP cells, suggesting that constitutive NO generation is not sufficient for triggering apoptosis in these cells. Besides NO generation, NOS is also capable of producing superoxide radicals. Sanguinarine-induced production of superoxide radicals, and the addition of MnTBAP, a scavenger of superoxide radicals, efficiently inhibited sanguinarine-mediated apoptosis. These results suggest that Cox-2 expression rescues prostate cancer cells from sanguinarine-induced apoptosis by a mechanism involving inhibition of NOS activity, and that coadministration of Cox-2 inhibitors with sanguinarine may be developed as a strategy for the management of prostate cancer.     

Differential potentiative effects of glutamate receptor antagonists in the production of antinociception induced by opioids administered intrathecally in the mouse

The effect of (+/-)-5-methyl-10,11-dihydro-5H-dibenzo(a,d) cyclohepten-5, 10-imine maleate (MK-801) or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) injected intrathecally (i.t.) on the inhibition of the tail-flick response induced by morphine, D-Ala(2)-NmePhe(4)-Gly-ol-enkephalin (DAMGO), beta-endorphin, D-Pen(2,5)-enkephalin (DPDPE), or ?(trans-3, 4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl) cyclohexyl] benzeocetamide)? (U50, 488H) administered i.t. was studied in ICR mice. The i.t. injection of MK-801 (2 microg) or CNQX (1 microg) alone did not affect the basal tail-flick response. Morphine (0.2 microg), DAMGO (0.8 ng), beta-endorphin (0.1 microg), DPDPE (0.5 microg) or U50, 488H (6 microg) caused only slight inhibition of the tail-flick response. CNQX injected i.t., but not MK-801, enhanced the inhibition of the tail-flick response induced by i.t. administered morphine, DAMGO, DPDPE or U50, 488H. However, CNQX or MK-801 injected i.t. was not effective in enhancing the inhibition of the tail-flick response induced by beta-endorphin administered i.t. The potentiating effect of CNQX on tail-flick inhibition induced by morphine, DAMGO, DPDPE or U50, 488H was blocked by naloxone (from 1 to 20 microg), yohimbine (from 1 to 20 microg) or methysergide (from 1 to 20 microg) injected i.t. in a dose-dependent manner. Our results suggest that the blockade of AMPA/kainate receptors located in the spinal cord appears to be involved in enhancing the inhibition of the tail-flick response induced by stimulation of spinal mu-, delta-, and kappa-opioid receptors. Furthermore, this potentiating action may be mediated by spinal noradrenergic and serotonergic receptors. However, N-methyl-D-aspartate receptors may not be involved in modulating the inhibition of the tail-flick response induced by various opioids administered spinally.     

Supraspinal NMDA and non-NMDA receptors are differentially involved in the production of antinociception by morphine and beta-endorphin administered intracerebroventricularly in the formalin pain model

Our previous studies have demonstrated that supraspinal glutamate receptors are differentially involved in the antinociception induced by morphine and beta-endorphin given intracerebroventricularly (i.c.v.) in the tail-flick and hot-plate tests. The formalin pain test was used in the present study. Injection of mice with formalin solution (2%, 10 microl) into the hindpaw intraplantarly produced the first (0-5 min) and second (20-40 min) phases of formalin responses. The formalin responses in the both phases were attenuated dose-dependently by morphine (0.125-1 microg) or beta-endorphin (0.125-1 microg) administered i.c.v. 5 min before. The antinociceptive effect of morphine was slightly more potent in the second phase whereas the effect of beta-endorphin was more pronounced in the first phase. MK-801 (0.1-1 microg), a non-competitive NMDA receptor antagonist, and CNQX (0.05-0.5 microg), a non-NMDA antagonist, given i.c.v., produced antinociceptive effect in the both phases, but only in a partial manner. Both MK-801 (0.05 microg) and CNQX (0.01 microg), at the dose which had no intrinsic effect, reversed the antinociceptive effect of beta-endorphin (1 microg) observed during the second, but not the first, phase partially but significantly. However, the antinociceptive effect of morphine (1 microg) was not affected by the same dose of MK-801 or CNQX given i.c.v. Our results indicate that, at the supraspinal level, both NMDA and non-NMDA receptors are involved in the production of antinociception induced by supraspinally administered beta-endorphin, but not morphine, in the formalin pain model.     

Effect of melatonin on the regulation of proenkephalin and prodynorphin mRNA levels induced by kainic acid in the rat hippocampus

The in vivo short-term effect of melatonin on kainic acid (KA)-induced proenkephalin (proENK) or prodynorphin (proDYN) mRNA, and on AP-1 protein levels in the rat hippocampus, were studied. Melatonin (5 mg/kg) or saline was administered intraperitoneally (i.p.) to rats 30 min prior to and immediately after i.p. injection of KA (10 mg/kg). Rats were sacrificed 1 and 3 h after KA injection. The proENK and proDYN mRNA levels were significantly increased 3 h after KA administration. The elevations of both proENK and proDYN mRNA levels induced by KA were significantly inhibited by the preadministration with melatonin. The increases of proENK and proDYN mRNA levels induced by KA were well-correlated with the increases of c-Fos, Fra-2, FosB, c-Jun, and JunB protein levels, which were significantly increased 3 h after KA administration and effectively inhibited by administration with melatonin. In an electrophoretic mobility shift assay, both AP-1 and ENKCRE-2 DNA binding activities were increased by KA, which were also attenuated by the administration of melatonin. In addition, cross-competition studies revealed that AP-1 or ENKCRE-2 DNA binding activity was effectively reduced by the 50x unlabeled cross-competitor. Therefore, these data suggest that melatonin has an inhibitory role in KA-induced gene expression, such as proENK and proDYN mRNA expression, and this may be due to a reduction of KA-induced AP-1 or ENKCRE-2 DNA binding activity.     

In vitro effects of hydroxybenzaldehydes from Gastrodia elata and their analogues on GABAergic neurotransmission, and a structure-activity correlation.

The present study was designed to characterize the modulatory effects of the constituents of Gastrodia elata and their analogues on the GABAergic neurotransmission. 4-Hydroxybenzaldehyde (1) and 4-hydroxy-3-methoxybenzaldehyde (4) inhibited potently the activity of GABA transaminase (IC(50) = 4.1 and 5.4 microg/ml, respectively), while the activity of another constituent, 4-hydroxybenzyl alcohol (2), was very weak. Further investigation with 10 analogues revealed a structure-activity correlation, suggesting that the aldehyde group and the hydroxy group at C-4 are necessary for the inhibitory effect on the enzyme activity. Some potent enzyme inhibitors were examined for the effect on the radioligands to the GABA(A) receptor complexes of rat cerebral cortices. Among them, the component 4 dose-dependently increased (20 - 30 %) the binding of [(3)H]flunitrazepam in the presence of GABA.