Glaucomatous neurodegeneration and the concept of neuroprotection

Glaucomatous neurodegeneration is a progressive pathological affair morphologically characterized by RGC death resulting in functional visual deterioration. Although a variety of primary insults ranging from mechanical trauma to ischemia to genetic susceptibility can initiate disease onset, apparently loss of trophic support and excitotoxin release remain the common themes responsible for neuronal damage and eventual cell death by apoptosis. The spread of this damage is perpetuated by secondary degeneration that allows directly injured neurons to release noxious and degenerative substances into the surrounding cells. Neuroprotection is a collective therapeutic approach the aim of which is to provide resilience to such neurons in an effort to prevent or delay progressive neuronal degeneration. At present, definitive neuroprotective therapy remains unachieved despite a variety of approaches having been defined and intensely pursued. However, the evolution in our understanding of glaucoma continues to offer reason for optimism. To this end, we remain unreservedly hopeful in the labor and committed work of dedicated investigators. We are all indebted to them.

Simultaneous determination of diazepam and pyridoxine in synthetic mixtures and pharmaceutical formulations using graphical and multivariate calibration-prediction methods

Several methods are reported for the simultaneous determination of diazepam and pyridoxine: two graphical methods (zero-crossing and derivative quotient spectra); and two numerical methods (multiple linear regression and partial least-squares regression). The methods have been applied in the concentration ranges 1.4-4.0 micrograms ml-1 diazepam and 4.0-12.0 micrograms ml-1 pyridoxine. The accuracy and precision of the methods have been determined and they have been validated by analysing synthetic mixtures containing the two drugs in variable proportions. The methods were also applied to the determination of diazepam and pyridoxine in pharmaceutical preparations. The analytical results were quite good in all cases.