N-(4-Trifluoromethylphenyl)amide group of the synthetic histamine receptor agonist inhibits nicotinic acetylcholine receptor-mediated catecholamine secretion

The therapeutic targeting of nicotinic receptors requires the identification of drugs that selectively activate or inhibit a limited range of nicotine acetylcholine receptors (nAChRs). In this study, we identified N-(4-trifluoromethylphenyl)amide group of the synthetic histamine receptor ligands, histamine-trifluoromethyltoluide, that act as potent inhibitors of nAChRs in bovine adrenal chromaffin cells. Catecholamine secretion induced by the nAChRs agonist, 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP), was significantly inhibited by histamine-trifluoromethyltoluide. Real time carbon-fiber amperometry confirmed the ability of histamine-trifluoromethyltoluide to inhibit DMPP-induced exocytosis in single chromaffin cells. We also found that histamine-trifluoromethyltoluide inhibited DMPP-induced [Ca(2+)](i) and [Na(+)](i) increases, as well as DMPP-induced inward currents in the absence of extracellular calcium. Histamine-trifluoromethyltoluide had no effect on [(3)H]nicotine binding or on calcium increases induced by high K(+), bradykinin, veratridine, histamine, and benzoylbenzoyl ATP. Among the synthetic histamine receptor ligands, clobenpropit exhibited similarity. In addition, 4'-nitroacetanilide also significantly attenuated nAChR-mediated catecholamine secretion. In conclusion, the N-(4-trifluoromethylphenyl)amide group of the histamine-trifluoromethyltoluide might be the critical moiety in the inhibition of nAChR-mediated CA secretion.

Regulation of p53 by activated protein kinase C-delta during nitric oxide-induced dopaminergic cell death

Selective cell death of dopaminergic neurons in the substantia nigra is the major cause of Parkinson disease. Current evidence suggests that this cell death could be mediated by nitric oxide by-products such as nitrate and peroxynitrite. Because protein kinase C (PKC)-delta is implicated in apoptosis of various cell types, we studied its roles and activation mechanisms in nitric oxide (NO)-induced apoptosis of SN4741 dopaminergic cells. When cells were treated with sodium nitroprusside (SNP), a NO donor, endogenous PKC-delta was nitrated and activated. Immunoprecipitation revealed that p53 co-immunoprecipitated with PKC-delta and was phosphorylated at the 15th serine residue in SNP-treated cells. An in vitro kinase assay revealed that p53 was directly phosphorylated by SNP-activated PKC-delta. The p53 Ser-15 phosphorylation was suppressed in SNP-treated cells when the NO-mediated activation of PKC-delta was inhibited by rottlerin or (-)-epigallocatechin gallate. Within 3 h of p53 phosphorylation, its protein levels increased because of decreased ubiquitin-dependent proteosomal proteolysis, whereas the protein levels of MDM2, ubiquitin-protein isopeptide ligase, were down-regulated in a p53 phosphorylation-dependent fashion. Taken together, these results demonstrate that nitration-mediated activation of PKC-delta induces the phosphorylation of the Ser-15 residue in p53, which increases its protein stability, thereby contributing to the nitric oxide-mediated apoptosis-like cell death pathway. These findings may be expanded to provide new insight into the cellular mechanisms of Parkinson disease.

Inhibition of store-operated calcium entry-mediated superoxide generation by histamine trifluoromethyltoluide independent of histamine receptors

Store-operated calcium entry (SOCE) plays an important role in shaping the Ca(2+) response of various tissues and cell types. In this report, we show that thapsigargin (TG)-induced SOCE was inhibited by the histamine receptor agonist, histamine-trifluoromethyltoluide (HTMT), in U937 and HL-60 human promyelocytes. Preincubation of HTMT resulted in a significant inhibition of subsequent TG-induced Ca(2+) elevation without affecting Ca(2+) release from intracellular stores. HTMT also inhibited TG-induced Ca(2+) current and Ba(2+)/Mn(2+) influx in a concentration-dependent manner. In contrast with HTMT, other H1 histamine receptor agonists, histamine, 2-methylhistamine and 2-thiazolylethylamine, did not affect TG-induced SOCE. In addition, HTMT also attenuated TG-induced cytosolic superoxide generation. Taken together, our data clearly suggest that the anti-inflammatory effect of HTMT may occur through direct inhibition of SOCE.

Effect of rottlerin, a PKC-δ inhibitor, on TLR-4-dependent activation of murine microglia

In microglia, Toll-like receptors have been shown to recognize pathogen-associated molecular patterns and initiate innate immune responses upon interaction with infectious agents. The effect of rottlerin, a PKC-delta specific inhibitor, on TLR-4-mediated signaling was investigated in murine microglia stimulated with lipopolysaccharide and taxol. Pretreatment of microglia cells with rottlerin decreased LPS- and taxol-induced nitric oxide production in a concentration-dependent manner (IC50 = 99.1+/-1.5 nM). Through MTT and FACS analysis, we found that the inhibition effect of rottlerin was not due to microglial cell death. Rottlerin pretreatment also attenuated LPS-induced phosphorylation of IkappaB-alpha, nuclear translocation of NF-kappaB, and expression of type II nitric oxide synthase. In addition, microglial phagocytosis in response to TLR-4 activation was diminished in which rottlerin was pretreated. Together, these data raise the possibility that certain PKC-delta specific inhibitors can modulate TLR-4-derived signaling and inflammatory target gene expression, and can alter susceptibility to microbial infection and chronic inflammatory diseases in central nervous system.

A fatal case of Vibrio vulnificus meningoencephalitis

The objective of this paper is to report a rare case of Vibrio vulnificus presenting as meningoencephalitis without a wound infection. Vibrio vulnificus is capable of causing severe and often fatal infections in susceptible individuals. It commonly causes necrotizing wound infections, primary septicemia, and gastroenteritis. A 69-year-old man had meningoencephalitis with lesion on the red nucleus, substantia nigra, basal ganglia, and dentate nucleus as the initial clinical manifestation of a V. vulnificus infection. This is the first case of V. vulnificus infection in which MRI demonstrated the involvement of deep nuclei of the brain.

Magnesium sulfate does not reduce postoperative analgesic requirements

BACKGROUND

Because magnesium blocks the N-methyl-D-aspartate receptor and its associated ion channels, it can prevent central sensitization caused by peripheral nociceptive stimulation. However, transport of magnesium from blood to cerebrospinal fluid (CSF) across the blood-brain barrier is limited in normal humans. The current study was designed to evaluate whether perioperative intravenous magnesium sulfate infusion affects postoperative pain.

METHODS

Sixty patients undergoing abdominal hysterectomy received 50 mg/kg intravenous magnesium sulfate as a bolus dose followed by a continuous infusion of 15 mg x kg(-1) x h(-1) for 6 h (magnesium group) or the same volume of isotonic saline (control group). At the end of surgery, serum and CSF magnesium concentration were measured in both groups. The cumulative postoperative analgesic consumption was measured to assess the analgesic effect using a patient-controlled epidural analgesia device. Pain intensities at rest and during forced expiration were evaluated at 6, 24, 48, and 72 h postoperatively.

RESULTS

At the end of surgery, patients in the magnesium group had significantly greater postoperative serum magnesium concentrations compared with both preoperative and control group values (P < 0.001). Despite significantly higher serum magnesium concentrations in the magnesium group, there was no significant difference in magnesium concentration measured in postoperative CSF. Cumulative postoperative analgesic doses were similar in both groups. However, there was observed an inverse relation between cumulative postoperative analgesic consumption and the CSF magnesium concentration in both groups. Visual analog pain scores at rest and during forced expiration were similar and less than 4 in both groups.

CONCLUSIONS

Perioperative intravenous administration of magnesium sulfate did not increase CSF magnesium concentration and had no effects on postoperative pain. However, an inverse relation between cumulative postoperative analgesic consumption and the CSF magnesium concentration was observed. These results suggest that perioperative intravenous magnesium infusion may not be useful for preventing postoperative pain.

The transport of a reversible proton pump antagonist, 5, 6-dimethyl-2-(4-Fluorophenylamino)-4-(1-methyl-1,2,3, 4-tetrahydroisoquinoline-2-yl) pyrimidine hydrochloride (YH1885), across caco-2 cell monolayers

5,6-Dimethyl-2-(4-fluorophenylamino)-4-(1-methyl-1,2,3, 4-tetrahydroisoquinoline-2-yl) pyrimidine hydrochloride (YH1885) is under development as a novel acid pump antagonist by Yuhan Research Center. Previous studies have suggested that the AUC and C(max) of orally dosed YH1885 are dose-dependent in the range of 2 to 500 mg/kg. The objective of the present study was to investigate the absorption mechanism of YH1885 using a human colon carcinoma cell line, Caco-2. The cells were grown to confluency on a permeable polycarbonate membrane insert to permit loading of YH1885 on either the apical or basolateral side of the cell monolayer. The flux across the monolayer from the apical to basolateral side was 3 to 5 times greater than that from the basolateral to apical side. The uptake of YH1885 into the Caco-2 cell monolayer was saturable and appeared to be mediated by a high-affinity transporter, with an apparent K(m) of 1.47+/-0.21 microM and a V(max) of 25.14+/-1.16 pmol/cm(2)/40 s. The apical to basolateral transport across the monolayer was Na(+)-independent, H(+)-sensitive, and energy-dependent. The transport was inhibited significantly by the presence of structural analogs of YH1885 (e.g., YH957, YH1070, and YH1041), some pyrimidine nucleobases (uracil and 5-methyluracil), and nucleobase transport inhibitors (e.g., papaverine, dipyridamole, and phloridzin). These results demonstrate that the apical to basolateral transport of YH1885 across the Caco-2 cell monolayer is partially mediated by a nucleobase transport system, which exhibits high-affinity and energy-dependent properties for YH1885. Saturation of this transport system, in addition to the limited solubility of YH1885 (i.e., approximately 5.3 microM), appears to contribute to the dose-dependent bioavailability of the drug.

Application of spinel-type cobalt chromite as a novel catalyst for combustion of chlorinated organic pollutants

Various chromium-containing catalysts were tested for the total oxidation of trichloroethylene (TCE) as a model reaction for the catalytic combustion of chlorinated organic pollutants. A spinel-type cobalt chromite (CoCr2O4) among others was proven to be a very promising catalyst showing higher activity and higher CO2 selectivity than traditional alumina supported chromia. Even if both Cr3+ and Cr6+ species were observed on the surface of CoCr2O4, the Cr6+ species was stable under reducing environment. The presence of Cr3+-Cr6+ pair sites and the effect of redox treatments on the activity were investigated to explain the nature of possible active sites for TCE decomposition. Higher selectivity to CO2 of CoCr2O4 was ascribed to the abundance of its Cr3+ species, together with its activity for water gas shift reaction.

Synthesis and biological activity of 1beta-methyl-2-[5'-isoxazoloethenylpyrrolidin-3'-ylthio]carbapenems

A new series of 1beta-methylcarbapenems 1a-i bearing isoxazoloethenyl groups on the pyrrolidine ring has been prepared and evaluated for in vitro antibacterial activity and stability to DHP-I. Most compounds showed excellent antibacterial activity and high stability to DHP-I superior to that of meropenem. Of these new carbapenems, 1a,b,h exhibited the best combination of antibacterial activity and DHP-I stability.

Synthesis and biological properties of new 1beta-methylcarbapenems having tetrazolothioether moiety

The synthesis and biological activities of a series of new 1beta-methylcarbapenems 1a-l having tetrazolothioether moiety at C-5 position of pyrrolidine were described. Among these compounds, 1c showed the most potent antibacterial activity and advanced pharmacokinetics compared with imipenem and meropenem.

Compartment syndrome in a patient with X-linked agammaglobulinaemia and ecthyma gangrenosum. Case report

Compartment syndrome is a surgical emergency that requires immediate decompression. We know of no documented cases that describe ecthyma gangrenosum as a primary cause of compartment syndrome. We present a case of a baby with x-linked agammaglobulinaemia who developed compartment syndrome associated with systemic Pseudomonas aeruginosa infection and ecthyma gangrenosum of the leg. He was treated by debridement and fasciotomies followed by primary closure and skin grafting and made an uneventful recovery.

Synthesis and anti-inflammatory and analgesic activities of pyridyloxy- and phenoxyalkanoic acid derivatives

Synthesis of pyridyloxy-, pyridyloxyphenoxy- and phenoxylphenoxyalkanate derivatives and their anti-inflammatory and analgesic activities were investigated. Analysis of structure-activity relationships showed that in pyridyloxyalkanoic acid derivatives anti-edematous potency was associated with the presence of chlorophenoxypropionic acid moiety and 2-nitrated methyl propionates contributed to the analgesic activity.

Forebrain ischemia: effect on pharmacologically induced seizure thresholds in the rat

Seizures are common after severe cerebral ischemia. To examine the mechanisms underlying these seizures, we determined the impact of prior forebrain ischemia on the seizure thresholds of four convulsants with differing modes of action: lidocaine, pentylenetetrazol (PTZ), N-methyl-D-aspartate (NMDA), and picrotoxin. Anesthetized Sprague-Dawley rats were chronically instrumented with screw electrodes and vascular catheters, and then subjected to 10 min of forebrain ischemia, produced by carotid occlusion and hypotension (mean arterial pressure to 30 mmHg). Animals were then awakened. 6, 24 or 48 h later, groups of awake animals received intravenous infusions of the four drugs. The total dose of drug infused prior to either electrical seizures (lidocaine, PTZ, and picrotoxin) or tonic-clonic convulsions (all drugs) were noted. For each drug, a group of Sham animals (no ischemia) served as controls. There were markedly different patterns of changes in the convulsant thresholds for the drugs. For example, at 6 h post-ischemia, rats treated with lidocaine died before convulsing, while the threshold for PTZ increased by 86%. There was no change in the picrotoxin threshold at 6 h, but the dose of NMDA needed to induce tonic-clonic seizure activity was reduced by 70%. By 48 h, lidocaine and PTZ thresholds had returned to values similar to those in Shams, but the NMDA threshold had now increased to a value 62% greater than Sham. Ten minutes of cerebral ischemia is followed by a complex and changing pattern of susceptibility to chemical convulsants. Finding suggests that early post-ischemic seizures may be related to increased NMDA receptor sensitivity.

Explosive burns during abusive inhalation of butane gas

Explosion burns during abusive inhalation of butane gas rarely occurred in the past, but recently it has become a social problem among groups of teenagers. This cause constitutes 1.6% of admissions due to flame burn at the burn unit of Hallym Medical Center. A retrospective review during a five-year period identified 48 patients. The male to female ratio was 3:1. The mean age of patients was 16 years and 8 months. The places where the accidents occurred were commonly bedrooms or motel rooms. There were nine group settings of 27 patients at the time of the accident. Inhalation injury (n = 12) was noted on admission. The average burn size was 28.5 percent of the total body surface area. All patients sustained burn injury on the face, arms and hands and 24 patients among them had extended burn areas on the trunk and/or lower extremity. 22 patients (mean hospital stay; 51.6 d) required skin grafting and 12 patients (mean hospital stay; 22.3 d) were treated with conservative management. The mortality rate was 10.4 percent. Explosion burns during abusive inhalation of butane gas can result in mortality as well as major burn injuries.

The indications for and techniques and outcomes of ablative procedures of the distal ulna. The Darrach resection, hemiresection, matched resection, and Sauvé-Kapandji procedure

Several ablative procedures exist for the treatment of distal radio-ulnar joint arthritis. This article describes the indications, techniques, pitfalls, and outcomes for the four most popular procedures: Darrach, hemiresection-interposition, Sauvé-Kapandji, and matched ulnar resection. The authors explain their personal algorithm for treatment selection, emphasizing patient requirements versus the physiologic characteristics of each procedure.

Absorption effect in the calculation of a second-order nonlinear coefficient from the data of a maker fringe experiment

The effect of light absorption by sample in the analysis of Makerfringe data for estimating a second-order nonlinear coefficient hasbeen studied experimentally. Two theories, one by Jerphagnon andKurtz that neglects the absorption effect and one by Herman and Haydenthat takes into account the absorption effect, were compared with theexperimental results. It was found that Jerphagnon and Kurtz'sformula was unable to predict correctly not only the magnitude but alsothe incident angle dependence or the sample thickness dependence of thesecond harmonic signal generated by the sample with strong absorption, whereas the theory by Herman and Hayden was able to make thosepredictions fairly well. It was also found that the error in theestimated nonlinear coefficient when one uses Jerphagnon and Kurtz'sformula could be as large as 2-4 times the true value, depending onsample thickness.