OBJECTIVETo prepare a zinc porphyrinated polyimide nanofibrous membrane for rapid detection of trace amount of ammonia.

METHODSZinc porphyrin chromophore was copolymerized into polyimide backbones and the according nanofibrous membrane was prepared by electrospinning technique. Ammonia detection was achieved by recording the color and spectral changes of the membrane before and after exposing to the target gas. The sensitivity, selectivity and detection limit of prepared membrane were further studied.

RESULTSThe obtained nanofibrous membrane preserved typical photophysical properties of zinc porphyrin chromophores. When exposed to ammonia, a dual chromo and spectrum responses of the nanofibrous membrane were observed. The binding affinity constant and the detection limit of zinc porphyrinated polyimide nanofibrous membrane calculated from surface plasmon resonance (SPR) analysis and UV-vis were 3.33 X10³ L/mol and 3.13 mg/m³, respectively.

CONCLUSIONThe membrane prepared in this study exhibits good sensitivity, selectivity and reproducibility towards ammonia detection.

Ammonia ; analysis ; Imides ; Membranes, Artificial ; Metalloporphyrins ; Nanostructures ; Sensitivity and Specificity ; Surface Plasmon Resonance ; methods

The results of study showed no significant differences on the stability of eye drop preparation containing vitamin B5 kept in neutral glass bottle and in PE vial. Light and high temperature make impact on the stability of the preparation so it needs to be kept from light in a cool place. With selected formula, the eye drop containing vitamin B5 kept in PE vial has stability at least 12 months at room conditions
Ophthalmic Solutions ; Pantothenic Acid

Adult ; Dermatitis, Occupational ; etiology ; Drug Eruptions ; etiology ; Humans ; Male ; Phthalimides ; adverse effects

BACKGROUND: Recently, the phannacologic and therapeutic significance of various types of potassium channels are being realized. Thus it was attempted to delineate the role of voltage-gated K+ -channels on the excitation-contraction coupling in skeletal muscle. METHODS: The effects of tetraethylammonium, a well known K+ -channel blocker, on the electrically-evoked twitch response, train-of-four and tetanic stimulation, and the influence of various agents on the these effects were studied in the isolated rat hemi-diaphragm preparation. RESULTS: Tetraethylammonium (1 & 3 mM) increased the electrically-evoked twitch response, but the large dose (10 mM) decreased the twitch response. And tetraethylammonium decreased the TOF- and tetanus-ratio in a dose-related fashion. d-Tubocurarine(1 microM) decreased the twitch response, and tetraethylammonium recovered the d-tubocurarine-induced-depression of twitch response. When the Ca++(6x) and K+ (2x) concentration of the medium were increased, the twitch response caused by tetraethylammonium were slightly inhibited than that observed in the normal solution, but the fade phenomenon was potentiated. The tetraethylammonium (10 mM)-induced depression of twitch response were reduced by reducing the stimulus frequency to 0.01 Hz and choline (400 microM) treatment. And N-ethylmaleimide inhibited the tetraethylammonium-induced increment of twitch response and also potentiated the tetraethylammonium-induced fade phenomenon. However, it is noteworth the 4-aminopy- ridine, another K+ -channel bloker, potentiated the electrically-evoked twitch response but did not affect the TOF-and tetanusratio. CONCLUSION: These result indicate that tetraethylammonium elicited two districtive types of response in the rat phrenic-hemidiaphragm preparation. The potentiating effects of twitch response is mediated by blocking delayed K+ -rectifier channel and decreasing effects of twitch response, TOF-and tetanus-ratio is may be due to decreased the acetylcholine release from presynaptic nerve terminal.
Acetylcholine ; Animals ; Choline ; Depression ; Ethylmaleimide ; Muscle, Skeletal ; Potassium Channels ; Rats* ; Tetraethylammonium*

The effect of buffer system, adjustment substance pH, pH of solution, antioxygen and antiseptic on the stability of eye drop solution with vitamin B5 was studied. The result: at pH 5,5, buffer system of acetat, of citrat and of phosphat strictly influence to the stability of eye drop solution containing vitamin B5. This solution also sustained with antioxygen dinatri edetat 0,02%, combining with natri metabisulfid 0,1% -0,3% don’t make increase the stability of product. The antiseptic of benzalkonium clorid and chlorobutanol don’t influence to the stability of this solution. But benzalkonium clorid is appropriate than chlorobutanol because of it don’t absorb through PE plastic, the antiseptic efficacy increase with the presence of dinatri edetat and this make increase the bioavailability of drug
Ophthalmic Solutions ; Pantothenic Acid ; Pharmaceutical Preparations

PURPOSE: Replication error is an important mechanism in carcinogenesis. The microsatellite instability (MSI-H) of colorectal cancers is associated with the development of multiple cancers. The influence of MSI-H on the development of multiple gastric cancers in sporadic gastric cancer patients has not been defined. This study was performed to reveal the association between the clinicopathologic features and MSI in sporadic gastric cancers. MATERIALS AND METHODS: Between July 2004 and March 2009, the clinicopathologic characteristics, including MSI status, were evaluated in 128 consecutive patients with sporadic gastric cancers. None of the patients had hereditary non-polyposis colorectal cancer of familial gastric cancer. The markers that were recommended by the NCI to determine the MSI status for colorectal cancers were used. RESULTS: MSI-H cancers were found in 10.9% of the patients (14/128). Synchronous gastric cancers were shown in 4 patients (3.1%). Synchronous cancers were found in 2 of 14 patients with MSI-H gastric cancer (14.3%) and 2 of 114 patients with MSS gastric cancer (1.8%; P=0.059, Fisher's exact test). Among the patients with synchronous cancer 50% (2/4) had MSI-H cancer, but 9.7% of the patients (12/124) without synchronous cancer had MSI-H cancer. MSI-H (RR, 24.7; 95% CI, 1.5~398.9; P=0.024) was related with to synchronous gastric cancer, but age, gender, family history, histologic type, location, gross morphology, size, and stage were not related to synchronous gastric cancer. CONCLUSIONS: MSI is associated with the intestinal-type gastric cancer and the presence of multiple gastric cancers in patients with sporadic gastric cancer. Special attention to the presence of synchronous and the development of metachronous multiple cancer in patients with MSI-H gastric cancer is needed.
Colorectal Neoplasms ; Humans ; Microsatellite Instability ; Microsatellite Repeats ; Stomach Neoplasms ; Succinimides

OBJECTIVE: Microscrew implants (MSIs) offer many advantages, but some complications are known to occur during their insertion. One of the most commonly reported complications is root injury. Our aim was to identify factors associated with root injury and to evaluate their qualitative and quantitative values. METHODS: Thirty-five orthodontists placed MSIs (AbsoAnchor(R), Dentos Co. Ltd, Daegu, Korea) in the upper jaw of typodonts, labially between the second premolar and the first molar, in low and high vertical positions. Root contacts were counted, and distances between MSI apices and roots were measured. Fear level of the orthodontists was surveyed before and after the experiment. Wilcoxon's test, chi-square test, and Mann-Whitney test were used for statistical analysis. RESULTS: Overall root contact rate of MSI insertion was 23.57%. The root contact rate was significantly higher in MSIs inserted at 90degrees (45.71%) than at 30degrees (1.43%). The distance between the dental root and MSI also increased significantly in MSIs inserted at 30degrees. Mean fear level before MSI insertion (4.6) significantly decreased after insertion (3.2); the causative factors were risk of injury to dental root and maxillary sinus or mandibular canal. CONCLUSIONS: Root injury is relatively rare, and oblique angulation reduces the risk of root and MSI contact.
Bicuspid ; Evaluation Studies as Topic ; Jaw ; Maxillary Sinus ; Molar ; Succinimides

When reduced glutathione(GSH) was incubated at neutral pH and at 37degrees, its concentration decteased slowly with formation of oxidized glutathione(GSSG). Autooxidation of GSH was accelerated by Cu2+ and Hg2+, but not by other common mono-, di-, and tri-valent cations. Tranthyretin was found to stimulate autooxidation of GSH in the presence or absence of Cu2+ and Hg2+. EDTA inhibited perfectly the autooxidation of GSH regardless of the presence of transthyretin. The stimulating activity of transthyretin was maximal at pH 7.0, declining progressively with increase or decrease of pH from 7.0. Sulfhydryl-blocking agents such as p-hydroxymercuribenzoic acid and N-ethylmaleimide markedly inhibited the stimulating activity of transthyretin. Transthyretin stimulated autooxidation of other sulfhydryl compounds such as dithiothreitol and cysteine. However, it did not show a significant effect on autooxidation of sulfhydryl group of egg albumin and eye lens proteins. And transthyretin did not cause any oxidative change to thyroxine(T4), 3, 5, 3'-tri iodo thyronine(T3) and 3, 3', 5'-triiodothyronine(rT3) bound to it in the presence of GSH and Cu2+. The above results suggest that transthyretin may play a role in regulation of oxidized status of sulfhydryl groups in blood plasma and cerebrospinal fluid.
Cations ; Cerebrospinal Fluid ; Crystallins ; Cysteine ; Dithiothreitol ; Edetic Acid ; Ethylmaleimide ; Glutathione* ; Hydrogen-Ion Concentration ; Ovum ; Plasma ; Prealbumin* ; Sulfhydryl Compounds

BACKGROUNDQacA, a main exporter mediating the multidrug-resistance of Staphylococcus aureus to a variety of antiseptics and disinfectants, possesses a topology of 14 alpha-helical transmembrane segments (TMS). Our study aimed to determine the importance and topology of amino acid residues in and flanking the cytoplasmic end of TMS5.

METHODSSite-directed mutagenesis was used to mutate 5 residues, including L146, A147, V148, W149 and S150, into cysteine. A minimum inhibitory concentration (MIC) and transport assay with or without N-ethylmaleimide (NEM) were performed to analyse the function of these mutants.

RESULTSAll of the mutants showed comparable protein expression levels. MIC analysis suggested that mutant W149C showed low resistance levels to the drugs, but the mutations at L146, A147, V148, and S150C had little or no effect on the resistance level. And the results of the fluorimetric transport assay were in agreement with those of MIC analysis, that is to say, W149C did not allow transport to the substrates to be tested, while the other mutants retained significant transport ability. The reaction of the different mutant proteins with Fluorescein-NEM revealed that the mutant L146C was highly reactive with NEM; the W149C and S150C mutants were moderately reactive; A147C was barely reactive and V148C showed no reactivity.

CONCLUSIONSThe study identified that residues W149 and S150 situated at the interface of the aqueous: lipid junction as functionally important residues, probably involved in the substrate binding and translocation of QacA.

Bacterial Proteins ; chemistry ; physiology ; Drug Resistance, Bacterial ; Ethylmaleimide ; pharmacology ; Indoles ; metabolism ; Membrane Transport Proteins ; chemistry ; physiology ; Structure-Activity Relationship

In this study, we determined mode of action of a novel carbamoyloxy arylalkanoyl arylpiperazine compound (SKL-NP) on hyperpolarization-activated cyclic nucleotide-gated (HCN) channel currents (Ih) that plays important roles in neuropathic pain. In small or medium-sized dorsal root ganglion (DRG) neurons (<40 microm in diameter) exhibiting tonic firing and prominent Ih, SKL-NP inhibited Ih and spike firings in a concentration dependent manner (IC50=7.85 microM). SKL-NP-induced inhibition of Ih was blocked by pretreatment of pertussis toxin (PTX) and N-ethylmaleimide (NEM) as well as 8-Br-cAMP, a membrane permeable cAMP analogue. These results suggest that SKL-NP modulates Ih in indirect manner by the activation of a Gi-protein coupled receptor that decreases intracellular cAMP concentration. Taken together, SKL-NP has the inhibitory effect on HCN channel currents (I h) in DRG neurons of rats.
Animals ; Diagnosis-Related Groups ; Ethylmaleimide ; Fires ; Ganglia, Spinal ; Membranes ; Neuralgia ; Neurons ; Pertussis Toxin ; Rats ; Spinal Nerve Roots