ED50 G Na Block Predictions for Phenyl Substituted and Unsubstituted n-Alkanols

To study the role the phenyl group plays in producing local anesthetic block, a sequence of n-alkanols and phenyl-substituted alkanols (Φ-alkanols) were characterized in their ability to block Na channels. The sequence of n-alkanols studied possess 3–5 carbons (propanol-pentanol). The action of phenol and 3-Φ-alkanols (benzyl alcohol, phenethyl alcohol, 3-phenyl-1-propanol) were also studied. Na currents (I _Na ) were recorded from single frog skeletal muscle fibers using the Vaseline-gap voltage clamp technique. I _Na s were recorded prior to, during, and following the removal of the solutes in Ringer's solution. All alkanols and phenol acted to block I _Na in a dose-dependent manner. Effective doses to produce half block (ED₅₀) of I _Na or Na conductance (G _Na ) were obtained from dose-response relations for all solutes used. The block of G _Na depended on voltage, and could be separated into voltage-dependent and -independent components. Each solute acted to shift G _Na -V relations in a depolarized direction and reduce the maximum G _Na and slope of the relation. All solutes acted to speed up I _Na kinetics and cause hyperpolarizing shifts in steady-state inactivation. The magnitude of the kinetic changes increased with dose. Size was an important variable in determining the magnitude of the changes in I _Na ; however, size alone was not sufficient to predict the changes in I _Na . ED₅₀s for G _Na and AP block could be predicted as a function of intrinsic molar volume, hydrogen bond acceptor basicity (β) and donor acidity (α), and polarity (P) of the solutes. The equivalency of ED₅₀ predictions for AP and G _Na block can be explained by the fact that AP block arises from channel block and solute-induced changes in I _Na kinetics. Φ-alkanols were more effective at blocking and inactivating Na channels than their unsubstituted counterparts. Phenyl-substituted alkanols are more likely to interact with the channel than their unsubstituted counterparts. Received: 11 August 2000/Revised: 21 December 2000     

Effect of Physicochemical Parameters on the Formation of Chitosan-Based Gels

The possibility for forming physical gels based on Pchelozan (bee chitosan with a molecular weight of 230 kDa and an acetylation degree of 26–65%) has been demonstrated. Conditions for obtaining the gels (1% solution in 1% glycolic acid, 25°C, pH 5.5–7.5) were selected. The effects of (1) the concentration of the original solution, (2) the degree of acetylation of Pchelozan, and (3) the value of pH on the process of gel formation, were studied. The gels obtained may be classified with reversible toxotropic systems. These gels are stable for a long time when stored within a temperature range of 18–55°C. The gel with a degree of acetylation of 34% was characterized by irreversible syneresis.     

Phenyl pyrazolones--novel oxidoreductase redox-mediators for degradation of xenobiotics

An approach was developed to screening organic compounds for putative activity of redox mediators of oxidoreductases, including laccases and peroxidases, applicable for xenobiotic degradation. The study was carried out with a homogenous laccase preparation from the basidiomycete Trametes hirsuta and horse-radish root peroxidase. Compounds belonging to 1-phenyl-3-methylpyrazolones were selected. Spectroscopic and electrochemical investigation of two of the compounds, sodium 1-phenyl-2,3-dimethyl-4-aminopyrazolon 5n(4)-methanesulfonate (PPNa) and 1-(3'-sulfophenyl)-3-methylpyrazolone (SPP), was performed. Electrochemical oxidation of both PPNa and SPP gave rise to high-potential intermediates capable of oxidizing veratryl alcohol; a lignin-modeling compound. Kinetic indices of these compounds were determined in enzymatic reactions with the presence of laccase. It was shown that enzymatic oxidation of SPP by laccase produced high-potential intermediates capable of oxidizing veratryl alcohol to veratric acid. Veratryl alcohol did not oxidize during enzymatic oxidation of SPP by peroxidase. This points to a difference between the mechanisms of enzymatic oxidation of PPNa and SPP by laccase and peroxidase.     

Characterisation of STREAMLINETM Phenyl

STREAMLINE Phenyl is a new hydrophobic interaction chromatography support designed for use in expanded bed adsorption. The phenyl groups are linked to STREAMLINE matrix via highly stable ether linkages. Within this development project the chemical and chromatographic stability as well as the breakthrough capacity for human IgG has been studied. The chemical stability was monitored as the carbon leakage from the matrix to the storage solution, pH 1–14 at 20 and 40 °C. The carbon content in the supernatant was determined with Total Organic Carbon (TOC) technique. In the chromatographic stability study STREAMLINE Phenyl was stored in eight different storage solutions under ambient conditions for 12 weeks and then tested in a chromatographic function test. The results show that the adsorbent is chemically stable and that the chromatographic properties are retained under the tested conditions. The breakthrough capacity study demonstrates the importance of the bed height for obtaining maximal dynamic capacity. Further, there is a good correlation between breakthrough data generated from packed bed and expanded bed runs.     

Assessment of Water Quality of Soan River using Physicochemical Parameters and Aquatic Insects Diversity

Biology Bulletin - In the present study, the effect of pollutants produced by human dwelling, agricultural and industrial activities on aquatic invertebrate’s communities of Soan River,...     

Application of Physicochemical Properties and Process Parameters in the Development of a Neural Network Model for Prediction of Tablet Characteristics

The importance of in silico modeling in the pharmaceutical industry is continuously increasing. The aim of the present study was the development of a neural network model for prediction of the postcompressional properties of scored tablets based on the application of existing data sets from our previous studies. Some important process parameters and physicochemical characteristics of the powder mixtures were used as training factors to achieve the best applicability in a wide range of possible compositions. The results demonstrated that, after some pre-processing of the factors, an appropriate prediction performance could be achieved. However, because of the poor extrapolation capacity, broadening of the training data range appears necessary.     

Correlations Between Predominant Heterotrophic Bacteria and Physicochemical Water Quality Parameters in Two Canadian Rivers

The heterotrophic bacterial populations in two contrasting rivers have been examined over a period of 1 year. The populations were analyzed (i) as total heterotrophic counts, (ii) as species numbers, using numerical taxonomy, (iii) by diversity indices, and (iv) by factor analysis. Isolates were obtained by plating directly from water samples and by chemostat enrichment. Four factors emerged which profiled the bacterial community and were common to both rivers. They were, in order of decreasing importance, fermentative metabolism, inorganic nitrogen metabolism, fluorescence-oxidative metabolism, and lack of starch hydrolysis. Several factors produced significant correlations with a range of physicochemical parameters, which were also measured. The correlations suggested an intricate algal-bacterial interaction. The oxidative metabolism factor correlated with rainfall in one river, suggesting that the oxidative bacteria may be washed in from the surrounding land. In the other river, the oxidative-fermentative factor correlated negatively with sunshine. Factor analysis was the most effective method for revealing correlations between bacterial characteristics and the environmental parameters; however, the use of a variety of methods provided more insight into the ecological aspects.     

Physicochemical Parameters of the Blood Serum and Renal Function in Children with Some Internal Diseases

The blood serum osmolality and ion concentrations were studied in 144 children (healthy or having some diseases), and no deviations from the universally accepted normal values were found. Although the mean values were in the normal range, the diseases were associated with an increased variation of serum osmolality and ion concentrations, indicating an imbalance of the regulatory system. Normally, human urine is hyperosmolal and the urination depends on the excretion of osmotically active substances. This determines a physiological paradox: an increase in diuresis is accompanied by a concurrent increase in reabsorption of osmotically free water.     

SATE (Aryl) Phosphotriester Series. II. Stability Studies and Physicochemical Parameters

Abstract

The stability of phosphotriester derivatives of 3′-azido-2′,3′-dideoxythymidine (AZT) bearing a S-pivaloyl-2-thioethyl (tBuSATE) group and various aryl residues derived from L-tyrosine was evaluated in biological media. The results demonstrate that such compounds give rise to intracellular delivery of the parent mononucleotide through esterase and phosphodiesterase hydrolytic steps, successively.     

Antioxidant Properties of Phenyl Styryl Ketones

Phenolic and non phenolic derivatives of phenyl styryl ketones were synthesized and evaluated as in vitro inhibitors of iron and cumene hydroperoxide dependent lipid peroxidation in rat brain homogenates. The compounds were also tested for antioxidant activity in phosphatidylcholine liposomes. Phenyl 3, 5-ditert-butyl-4-hydroxystyryl ketone was found to be the most potent inhibitor of peroxidation among all the compounds tested. It was found to be more active than vitamin E. It also reduced the stable free radical l,l-diphenyl-2-picrylhydrazyl to an appreciable extent.     

Substituted polymethylglutamate membrane for immobilization of urease

Poly-γ-methyl-l-glutamate (PMG) was modified and used for enzyme immobilization. Trichloroethyl ester (TCE) and three kinds of amino groups (ethylenediamine, ED; 1,8-diamino-4-amino-methyloctane, TA; polyethyleneimine, PEI) were introduced into the pendant group of PMG. A membrane was prepared from these polymers for enzyme immobilization. Urease was immobilized on each membrane using glutaraldehyde or water-soluble carbodiimide. Urease was very stable when it was immobilized with water-soluble carbodiimide on the membrane having PEI in the pendant group. The characteristics of immobilized urease were also discussed.     

Phenyl indane from acorus calamus

Besides three known compounds, two new compounds, namely Z-3-(2,4,5-trimethoxy phenyl)-2-propenal and a new phenyl indane have been isolated from the rhizomes of Acorus calamus. These compounds have been characterized from their spectral data and by synthesis.     

Physicochemical Parameters for Growth of the Sea Ice Bacteria Glaciecola punicea ACAM 611T and Gelidibacter sp. Strain IC158

The water activity and pH ranges for growth of Glaciecola punicea (a psychrophile) were extended when this organism was grown at suboptimal rather than optimal temperatures. No such extension was observed for Gelidibacter sp. strain IC158 (a psychrotolerant bacterium) at analogous temperatures. Salinity and pH may be primary physicochemical parameters controlling bacterial community development in sea ice.     

Phenyl sulfur mustard derivatives of distamycin A

The design, synthesis, and cytotoxic activity of novel benzoyl and cinnamoyl sulfur mustard derivatives of distamycin A are described and structure activity relationships are discussed. These sulfur mustards are more potent cytotoxics than corresponding nitrogen mustards in spite of the lower alkylating power, while their sulfoxide analogues are substantially inactive. Cinnamoyl sulfur mustard derivative (7) proved to be one of the most active distamycin-derived cytotoxics, about 1000 times more potent than melphalan.     

HBV整合片段对人PCNA基因启动子的调控

Ｈ７Ｃ是从一例肝癌组织中克隆得到的ＨＢＶ整合片段,其中保留有ｐｒｅＳ２基因的启动子及Ｃ端缺失的ｐｒｅＳ／Ｓ蛋白的阅读框架,我们用共转染方法研究了该整合片段地增殖细胞核抗原启动子的影响。结合表明在ＨｅｐＧ２细胞中,含有上述ＨＢＶ整合片段ＤＮＡ的质粒ＰＫＳＨ７Ｃ－ＨｐａＩ能以剂量依赖方式激活ＰＣＮＡ启动子。对ＳＶ４０启动子而言,ＰＣＮＡ启动子有１－２倍的更高激活。而破坏ｐｒｅＳ／Ｓ表达的两个亚克隆ＰＫ     

Inhibition of Monoamine Oxidase by Phenyl Azides

We had previously shown that 4-fluoro-3-nitrophenyl azide (FNPA) is a competitive inhibitor of both types of monoamine oxidase (MAO) in the dark, but it is a preferential photoaffinity label for only the type B MAO (MAO-B). Recently we synthesized a number of arylazido compounds with structures related to FNPA and determined the effects of these compounds on the two types of MAO in rat brain cortex. We found that the fluoro group of FNPA was not required for the inhibition of MAO activities because neither the presence nor the position of the fluoro group affected its inhibition of MAO. On the other hand, both the nitro and the azido groups of FNPA were shown to be important for FNPA inactivation of two types of MAO. The inhibitory potency was significantly lower for compounds without either group. Furthermore, we found that all nitrophenyl azide isomers except 2-nitrophenyl azide were photodependent inhibitors of MAO-B. Under the same experimental conditions none of the compounds photoinactivated MAO-A. On the basis of these findings, mechanisms for FNPA inhibition of the two types of MAO are discussed.     

Tissue 1,2-Glycol Localization with Phenyl Iodosoacetate

A solution of phenyl iodosoacetate in glacial acetic acid is capable of splitting the 1,2-glycol linkage in tissue sections to produce a histological picture with leucofuchsin resembling that obtained under similar conditions with lead tetraacetate.     

Influence of Physicochemical Parameters on the Abundance of Coliform Bacteria in an Industrial Site of the Hooghly River, India

Industrial effluents from jute, paper, pulp mills and sewage from households are regularly discharged into the Hooghly River. It generates a potential risk for both humans and animals of the area concerned. In the present study, water quality of the Hooghly River passing by the site of a growing township (Naihati, North 24 Parganas, West Bengal, India) was assessed throughout the year 2010 on the basis of the data collected on the physicochemical and microbiological parameters. The water samples collected on each month revealed the presence of higher amount of coliform bacteria, Streptococcus sp. and Escherichia coli, than the standard limit. Different physicochemical parameters like chemical oxygen demand, biological oxygen demand, dissolved oxygen (DO), total suspended solids, total dissolved solids (TDS), total hardness, alkalinity, chlorinity, nitrate and nitrite of the water at the sampling sites were found to be considerably higher than the levels standardized by WHO (2006). It was found that the relative abundance of Streptococcus and E. coli was influenced by two independent variables (water quality parameters), namely, DO and TDS. The abundance of coliform bacteria in the water sample warrants the adoption of proper measures to reduce the pollution level at the point source on way of scientific disposal of industrial effluents.