Chemical lesion technique

The transmitter pool of glutamate may be quantified after selective degeneration of the glutamate terminals by surgical or chemical lesions. By this technique the transmitter glutamate pool has been found to be 20-30% of the total glutamate content in neostriatum, thalamus, lateral septum, nucleus accumbens, and... 

There is no specific treatment for human papilloma virus infection (condylomata accuminata). Therapeutic modalities consist of chemically or physically destructive agents including the podo-phylllin (applied weekly as a 10% solution in benzoin) or the less toxic podophyllotoxin 0.5% (applied twice daily for three consecutive days every week for up to 4 weeks cure rates are generally <50% and relapses are common). For older lesions various surgical techniques are advocated that are beyond the scope of this contribution. 

Table 12.19. Chemical repair rates for 02-dependent free-radical precursors of lesions in V70 cells measured using the gas explosion technique. (Prise et al. 1992)...

For the detection of free-radical-induced DNA damage and its repair, biochemical techniques are increasingly applied. It would exceed the allocated space to discuss these techniques here, and the reader is referred to the original literature. However, to assist biologists and biophysicists, some of the chemical techniques for measuring typical DNA lesions are discussed. Most of the kinetic data concerning the free-radical chemistry of DNA and its model systems has been obtained by pulse radiolysis. This technique is only available in a few laboratories worldwide. For this reason, it will be described in some detail here. 

Evaluation of the effects of a toxicant on renal function can be accomplished by several methods. The method used depends on the complexity of the question to be answered. For example, unanesthetized or anesthetized animals may be used to determine if a chemical has an effect on kidney function. Investigations also may be conducted in vitro to examine specific biochemical or functional lesions. Finally, histopathologic techniques can provide a great deal of information about structural integrity. 

There are a number of surgical techniques and procedures used to treat eyelid and periocular lesions and anomalies. These techniques include chemical and thermal cautery, used to destroy tissue incision, used to cut into and/or separate tissue and excision, used to remove tissue. 

This chapter describes the results of an ongoing study we are conducting into the nanoscale mechanical properties, chemical composition and structure of healthy enamel, carious lesions and the acquired salivary pellicle layer. A variety of material characterization techniques are being used, including nanoindentation, scanning electron microscopy (SEM), electron microprobe analysis (EMPA), scanning acoustic microscopy, atomic force microscopy (AFM) and time-of-flight secondary ion mass spectroscopy (TOF SIMS). 

The chemical composition and structure throughout the lesions were evaluated using an SEM in conjunction with X-ray microprobe analysis (EMPA) and TOF SIMS. EMPA senses the chemistry of the sample to a depth of around 1 xm, while TOF SIMS is a surface technique that only identifies the surface atoms/ions. 

The study of Parkinson s disease is often done in animal models where one side of the brain is lesioned, generally via administration of a chemical, such as l-methyl-4-phenyl-l,2,3,6-tetrahydropyridine (MPTP) or 6-hydroxydopamine (6-OHDA), that disrupts the dopaminergic pathway. Differences in protein expression between the lesioned and unlesioned sides of the brain have been analyzed via MALDI MS. One study revealed significantly decreased levels of Purkinje cell protein 4 (PCP-4 or PEP-19) in the striatum of MPTP-lesioned mice compared to control [48], This result was in agreement with data acquired from a variety of other analytical techniques,... 

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