For instance, VP16 plays an important role in IE transcription and the virus particle apparently brings it into the host cell, so that it does not need to be produced first. Similarly, the IE proteins RS1 (ICP4), UL54 (ICP27), and ICP0 promote the transcription of the early (E) genes. Like IE genes, early gene promoters contain binding sites for cellular transcription factors. One early protein, ICP8, is necessary for both transcription of late genes and DNA replication.Later in the life cycle of HSV, expression of immediate early and early genes is shut down. This is mediated by specific virus proteins, e.g. ICP4, which represses itself by binding to elements in its own promoter. As a consequence, the down-regulation of ICP4 levels leads to a reduction of early and late gene expression, as ICP4 is important for both.Importantly, HSV shuts down host cell RNA, DNA and protein synthesis to direct cellular resources to virus production. First, the virus  protein vhs induces the degradation of existing mRNAs early in infection. Other viral genes impede cellular transcription and translation. For instance, ICP27 inhibits RNA splicing, so that virus mRNAs (which are usually not spliced) gain an advantage over host mRNAs. Finally,  virus proteins destabilize certain cellular proteins involved in the host cell cycle, so that both cell division and host cell DNA replication disturbed in favor of virus replication. Evolution
The herpes simplex 1 genomes can be classified into six clades.
Sodium calcium edetate (sodium calcium EDTA), also known as edetate calcium disodium among other names, is a medication primarily used to treat lead poisoning, including both short-term and long-term lead poisoning. Sodium calcium edetate came into medical use in the United States in 1953. Chelation agent
Sodium calcium edetate is in the chelating agent family of medication. It is a salt of edetate with two sodium and one calcium atoms. It works by binding to a number of heavy metals, which renders them almost inert and allows them to leave the body in the urine.Edetate disodium is a different formulation which does not have the same effects. Medical use
Sodium calcium edetates primary use is to treat lead poisoning,
for which it is an alternative to succimer. It is given by slow injection into a vein or into a muscle.For lead encephalopathy sodium calcium edetate is typically used together with dimercaprol. It may also be used to treat plutonium poisoning. It does not appear to be useful for poisoning by tetra-ethyl lead. Side effects
Common side effects include pain at the site of injection. Other side effects may include kidney problems, diarrhea, fever, muscle pains, and low blood pressure. Benefits when needed in pregnancy are likely greater than the risks. History
Sodium calcium edetate came into medical use in the United States in 1953. It is on the World Health Organizations List of Essential Medicines. References
External links
"Sodium calcium edetate". U.S. National Library of Medicine. Drug Information Portal. U.S. National Institutes of Health.