[The role of DFO in Al (mal) (3)-induced ferroptosis in PC12 cells].

Objective: To investigate the mechanism of Al (mal) (3)-induced ferroptosis in rat adrenal pheochromocytoma cells (PC12), to explore the effect of deferoxamine (DFO) . Methods: Taken PC12 cells growing at logarithmic phase and divided into 6 groups: control group, 200 µmol/L Al (mal) (3) group, 0.5% DMSO group, 200 µmol/L DFO group, Al (mal) (3)+DMSO group, Al (mal) (3)+DFO group. DMSO and DFO were added to the DMSO group and the Al (mal) (3)+DMSO group, the DFO group and the Al (mal) (3)+DFO group for 2 h, respectively, Al (mal) (3) was then added to the Al (mal) (3) group, Al (mal) (3)+DMSO group, and the Al (mal) (3)+DFO group to a final concentration of 200 µmol/L. The cell viability was detected by CCK8, the morphology and ROS levels of PC12 cells was observed by inverted microscope, the cell proliferation toxicity and intracellular iron ion content were detected by colorimetry, the GSH content and GSH-PX activity were detected by biochemical method. Results: Al (mal) (3) exposure significantly inhibited the growth of PC12 cells and destroyed the cell morphological structure, resulting in increased LDH activity and intracellular iron ion content in PC12 cells, decreased GSH content and GSH-PX activity, increased ROS levels; the combined treatment of Al (mal) (3)+DFO can significantly improve the cell viability of PC12 cells, improved cell morphology, decreased cell LDH activity and intracellular iron ion content (P>0.05), increased GSH content and GSH-PX activity, decreased ROS levels. Conclusion: Al (mal) (3) can induce ferroptosis in PC12 cells, DFO may inhibit ferroptosis by reducing intracellular iron levels and reducing oxidative damage.

A comprehensive study of risk factors for post-operative pneumonia following resection of meningioma.

BACKGROUND: Post-operative pneumonia (Pop) following meningioma surgery is the dominant systemic complication which could cause serious threats to patients. It is unclear whether hematological biochemical markers are independently associated with the Pop. This study attempted to perform a more comprehensive study of taking both clinical factors and hematological biomarkers into account to promote the management of patients after meningioma surgery. METHODS: We collected clinical and hematological parameters of 1156 patients undergoing meningioma resection from January 2009 to January 2013. According to whether the symptoms of pneumonia had manifested,patients were divided into the Pop group and the Non-Pop group. We analyzed the distinctions of clinical factors between the two groups. We successively performed univariate and multivariate regression analysis to identify risk factors independently associated with the Pop. RESULTS: 4.4% patients infected with the Pop (51 of 1156). The median age at diagnosis of the Pop patients was significantly older than the Non-Pop group (p = 0.002). There were strike distinctions of post-operative hospital stays between two groups, with 21 days and 7 days each (p < 0.001). On multivariate analysis, tumor relapse (p < 0.001), skull base lesions (p = 0.001), intra-operative blood transfusion (p = 0.018) and cardiovascular diseases (p = 0.001) were linked with increased risk of the Pop following meningioma resection. For hematological biochemical markers, it was the factor of Red blood cell distribution width-standard deviation (RDW-SD) (OR 5.267, 95%CI 1.316, 21.078; p = 0.019) and Neutrophils lymphocytes ratio (NLR) (OR 2.081, 95%CI 1.063, 4.067; p = 0.033) that could appreciably predict the Pop. CONCLUSIONS: Apart from tumor recurrence, localizations, intra-operative blood transfusion and cardiovascular diseases are independent risk factors for the Pop. We initially found hematological RDW-SD and NLR are also important predictors.

Effects of epidermal growth factor and transforming growth factor-beta on insulin-induced differentiation in rat dental pulp cells.

An established pulp cell line (RPC-C2A) was used to study the regulatory effect of insulin on dentinogenesis. Insulin increased alkaline phosphatase activity and the incorporation of [2,3-3H]-proline into collagenase-digestible protein, whereas [3H]-thymidine incorporation by the cells was inhibited by insulin. The enhancing effect of insulin on alkaline phosphatase activity was inhibited by epidermal growth factor (EGF) or transforming growth factor-beta (TGF-beta). The stimulatory effect of insulin on collagen synthesis was also inhibited when insulin was combined with EGF, but was accelerated by the addition of TGF-beta. Inhibitory effects of insulin on the [3H]-thymidine incorporation were potentiated by EGF, though EGF alone strongly increased the effect; whereas the addition of TGF-beta had no significant effect on the insulin action. These findings suggest that insulin may be concerned with the differentiation of pulp cells in dentinogenesis and that EGF or TGF-beta regulate the insulin effects.

(+-)-Octahydro-2-methyl-trans-5 (1H)-isoquinolone methiodide: a probe that reveals a partial map of the nicotinic receptor's recognition site.

A new, semirigid, nicotinic agonist (+-)-octahydro-2-methyl-trans-5 (1H)-isoquinolone methiodide was synthesized. The disposition of this agonist's nitrogen and carbonyl group conforms well to the prevailing notion of a pharmacophore for the nicotinic receptor. Comparing its structure and electrostatic potential surfaces, we predicted that its activity would be similar to that of carbamylcholine at the frog neuromuscular junction. Instead, the potency of the isoquinolone was only 0.015 times as potent as (+)-carbamylcholine. We conclude, after eliminating other possibilities, that the vicinity of the carbonyl group of an agonist must be planar to fit a confined space within the receptor's recognition site. The isoquinolone is a weak agonist because its methylene group beta to the carbonyl intrudes on this space.

Effects of transforming growth factor-beta and epidermal growth factor on clonal rat pulp cells.

These factors influence proliferation and differentiation in various cell types. Their effects on a clonal cell line (RPC-C2A) having high ALPase activity were examined by assay of [3H]-thymidine incorporation and ALPase activity. Neither factor (at a dose of 0.5 ng/ml) altered the shape of the pulp cells. DNA synthesis was not affected by transforming growth factor-beta either in growing cells or in those nearly confluent, but epidermal growth factor, in doses ranging from 0.5 to 10 ng/ml, stimulated the incorporation of [3H]-thymidine in nearly confluent cells. Both factors inhibited ALPase activity in a dose-dependent manner. Indomethacin did not affect this inhibition, suggesting that this effect of growth factors may not be mediated by prostaglandin synthesis. Inhibitory effects of ALPase antagonists (L-phenylalanine, L-homoarginine, levamisole) were not affected by transforming growth factor-beta. Thus epidermal growth factor stimulates DNA synthesis and both transforming growth factor-beta and epidermal growth factor inhibit ALPase activity of clonal rat pulp cells, suggesting that both factors may act as regulators of biological function, including cell differentiation, in pulp cells.

[Effects of various growth factors and hormones on clonal rat pulp cells].

Effects of transforming growth factor (TGF)-beta, epidermal growth factor (EGF), insulin, 1, 25-dihydroxyvitamin D3 (1, 25 (OH)2D3), and parathyroid hormone (PTH) on the proliferation and differentiation of clonal dental pulp cells of rats were investigated. Interaction between growth factors (TGF-beta and EGF) and two hormones insulin and 1, 25 (OH)2D3, which have been noticed to accelerate the differentiation of the cells, were also studied, and the following results were obtained: 1) TGF-beta decreased alkaline phosphatase (ALPase) activity in a dose-dependent manner, and the inhibitory effect was not blocked by indomethacin, suggesting that the effect of TGF-beta on the cells may not be mediated by prostaglandins. Inhibitory effects of ALPase antagonists (L-phenylalanine, L-homoarginine, levamisole) on the activity were not affected by TGF-beta. TGF-beta showed no evident effect on the DNA synthesis (incorporation of [3H] thymidine) and collagen synthesis (incorporation of [2, 3-3H] proline into the collagenase-digestible protein) of the cells. 2) EGF stimulated the incorporation of [3H] thymidine and inhibited the ALPase activity. The inhibitory effect was not blocked by indomethacin, indicating that the EGF effect is not mediated by prostaglandins. Collagen synthesis was significantly inhibited by EGF. 3) Insulin showed a weak but significant inhibition of the DNA synthesis. Insulin increased the ALPase activity evidently, and accelerated the collagen synthesis significantly. 4) The vitamin 1, 25 (OH)2D3 significantly increased the ALPase activity though no significant changes were observed in the DNA synthesis and collagen synthesis. 5) PTH had no evident effect on the DNA synthesis and ALPase activity, but did tend to accelerate the collagen synthesis. 6) A study on the interaction between insulin and EGF or TGF-beta revealed that the acceleration of DNA synthesis induced by EGF was inhibited when the factor was combined with insulin, and the increase in ALPase activity elicited by insulin was inhibited by EGF and weakened by TGF-beta significantly when these factors were added simultaneously with the insulin. Or viewed another way, the inhibitory effect of EGF or TGF-beta on the ALPase activity was antagonized by insulin. The accelerative action of insulin on collagen synthesis was antagonized by EGF and potentiated by TGF-beta. 7) A study on the interaction between 1, 25 (OH)2D3 and EGF or TGF-beta revealed that 1, 25 (OH)2D3 inhibited the accelerating effect of EGF on the DNA synthesis and that the increasing effect of 1, 25 (OH)2D3 on ALPase activity was strongly inhibited by EGF.(ABSTRACT TRUNCATED AT 400 WORDS)

[Effects of oral administration of various non-steroidal anti-inflammatory drugs on bone growth and bone wound healing in mice].

Morphometric and microdensitometric studies on normal bone growth and bone wound healing in growing ICR strain male mice were carried out as preliminary investigations. Then the effects of oral administration of non-steroidal anti-inflammatory drugs on bone growth and bone wound healing were studied. Femur length and width, and bone mineral contents in the femur as judged by microdensitometry of the soft x-ray films of the cortical portion of the femur showed time-dependent linear increase between 3 and 6 weeks of age. Wound holes were made in the parietal bones of mice with a dental bar at 4 weeks of age, and uncalcified area in the holes was determined by image analysis of soft x-ray films. The area decreased their size with the advance in age, especially a marked decrease was observed 2 weeks after the operation. From the above results, 4 week-old male mice were employed and 8 kinds of non-steroidal anti-inflammatory drugs (indomethacin, 1 mg/kg; mefenamic acid, 10 mg/kg; flufenamic acid, 10 mg/kg; diclofenac sodium, 1 mg/kg; ibuprofen, 10 mg/kg; naproxen, 10 mg/kg; phenylbutazone, 10 mg/kg and aspirin, 50 mg/kg) and dexamethasone (1 mg/kg), a steroidal anti-inflammatory drugs were administered orally every day for 9 or 11 days except Sunday, and 15 days after the initial administration, the length and width of the femur were measured. The bone mineral contents were determined by microdensitometry of the soft x-ray film of the femur. Hydroxyproline contents of the femur were also determined. Wound holes were made in the parietal bones at 4 week-old and administered the drugs from one day before the operation for 9 days and the uncalcified area in the wound hole was determined 2 weeks after the operation with an image analyzer. The results obtained were as follows: 1. A significant inhibition of the growth in length of the femur was observed by dexamethasone, diclofenac sodium and naproxen administration for 9 and 11 days. A significant inhibition of the growth in width was also observed by dexamethasone and diclofenac sodium administration for 9 days and by dexamethasone administration for 11 days.(ABSTRACT TRUNCATED AT 400 WORDS)

Synthesis, pharmacology, and molecular modeling studies of semirigid, nicotinic agonists.

Eight nicotinic agonists were synthesized, and their potencies were estimated by contracture of the frog rectus abdominis muscle. The most potent, 1-methyl-4-acetyl-1,2,3,6-tetrahydropyridine methiodide (3b), 50 times as potent as carbamylcholine, served as a template for the rest. Although all of the agonists could easily conform to the putative nicotinic pharmacophore, their potencies spanned a nearly 10,000-fold range. This pharmacophore, therefore, may be necessary but deficient. Computer-assisted molecular modeling studies helped to delineate additional factors that may contribute to potency. The factors are (1) the ground-state conformation, (2) superimposability of the hydrogen bond acceptor and the cationic head onto the template, (3) electrostatic potential at the cationic head and at the hydrogen bond acceptor site, and (4) the presence of a methyl group bonded to the carbon atom that bears the hydrogen bond acceptor. A new program, ARCHEM, was used to calculate and to visualize electrostatic potentials at the van der Waals surfaces of the agonists.

Structural and electronic requirements for potent agonists at a nicotinic receptor.

A new agonist, isoarecolone methiodide (1,1-dimethyl-4-acetyl-1,2,3,6-tetrahydropyridinium iodide) was tested at the frog neuromuscular junction. It was 50 times more potent than carbamylcholine, making it one of the most potent nicotinic agonists known. In addition, its cyclic structure and conjugated carbonyl bond endow it with near rigidity. An analogous compound, 1,1-dimethyl-4-acetylpiperazinium iodide, was synthesized because of its similar geometry and rigidity. It was 2.6 times as potent as carbamylcholine but only 0.053 times as potent as isoarecolone methiodide. Computer assisted molecular modeling and molecular orbital calculations revealed steric and electrostatic field differences between these two compounds.