The kinetics of the photocurrent in both rod and cone retinal photoreceptors are independent of membrane voltage over the physiological range (-30 to -65 mV). This is surprising since the photocurrent time course is regulated by the influx of Ca(2+) through cGMP-gated ion channels (CNG) and the force driving this flux changes with membrane voltage. To understand this paradigm, we measured Pf, t...

a topical preparation containing aceclofenac was developed using an o/w microemulsion system. isopropyl myristate was chosen as the oil phase as it showed a good solubilising capacity. pseudo-ternary phase diagrams were used to obtain the concentration ranges of the oil, surfactant (labrasol) and co-surfactant (plurol oleique) for microemulsion formation. five different formulations were formul...

OBJECTIVE In recent studies focusing on the prognostic significance of histologic features of NSCLC tumors, vessel invasion was correlated to survival across all surgical stages. We similarly analyzed whether intra-tumoral permeation could affect survival in subgroups of stage I and II NSCLC. METHODS A retrospective single institution analysis of a prospectively computed database. Specimens w...

I would like to address two key issues related to the Perspectives on Ion Permeation . The first is the estimate of the size of the physical forces relevant for ion transport. Any good physical model of ion permeation requires the identification of the dominant forces. The second subject concerns a careful definition of the terms “mean field” and “mean field approximation.” Several articles in ...

Outer membrane permeation of Bacteroides fragilis by cephalosporins was examined by a previously described method. The permeation parameters of cephalosporins in B. fragilis were close to 10(-5) cm3/min per microgram of cell dry weight. These values were about an order of magnitude lower than those in Escherichia coli. In B. fragilis, the permeation was not directly proportional to the hydrophi...

I would like to address two key issues related to the Perspectives on Ion Permeation . The first is the estimate of the size of the physical forces relevant for ion transport. Any good physical model of ion permeation requires the identification of the dominant forces. The second subject concerns a careful definition of the terms “mean field” and “mean field approximation.” Several articles in ...

Antimicrobial therapy remains to be the most important method of wound infection treatment. Systemically administered antimicrobials may not achieve therapeutic level in wound. On the other hand, in the absence of surgical debridement (due to any reason), most topically applied antimicrobials cannot penetrate the wound in therapeutic amount due to the presence of eschar. Burn eschar is a protei...

Many properties of chemicals depend on their stereochemistry. Among these, the effects of stereoisomerism on percutaneous absorption of drugs are not well studied. We have previously shown that permeation of tretinoin and isotretinoin (two geometric isomers) through hydrophilic enhancers-treated rat skin is stereoselective. As, depending on their lipophilicity, penetration enhancers can change ...

Many properties of chemicals depend on their stereochemistry. Among these, the effects of stereoisomerism on percutaneous absorption of drugs are not well studied. We have previously shown that permeation of tretinoin and isotretinoin (two geometric isomers) through hydrophilic enhancers-treated rat skin is stereoselective. As, depending on their lipophilicity, penetration enhancers can change ...

The permeability of the cornea to drugs is clinically important because it is the major factor determining the efficacy of topically applied ophthalmic preparations. With this perspective, the present article gives a brief update and overview of corneal structure and proposed mechanisms of permeation. Physiological, physicochemical and formulation factors affecting drug permeation through corne...