Urea nitrate is a powerful explosive. It has not found use as a legitimate explosive but is commonly used as an improvised explosive.

Pyrimidine is an aromatic heterocyclic organic compound with nitrogen atoms at positions 1 and 3 in the ring. The pyrimidine ring system has wide occurrence in nature as substituted and ring fused compounds and derivatives, including the nucleotides cytosine, thymine and uracil, thiamine (vitamin B1) and alloxan. It is also found in many synthetic compounds such as barbiturates and the HIV drug, zidovudine. Pyrimidines serve essential functions in human metabolism as ribonucleotide bases in RNA (uracil and cytosine), and as deoxyribonucleotide bases in DNA (cytosine and thymine), and are linked by phosphodiester bridges to purine nucleotides in double-stranded DNA, in both the nucleus and the mitochondria. Pyrimidine activated sugars are also involved in polysaccharide and phospholipid synthesis, glucuronidation in detoxification processes, glycosylation of proteins and lipids and in the recently identified novel endothelium-derived vasoactive dinucleotides.

An acute attack may be precipitated by drugs affecting the liver, by infection and by diet. The discovery of porphobilinogen in urine is a critical value that can eliminate or reduce adverse effects from drugs or anesthetics.

N, N – Dimethylarginine, more known as asymmetric dimethylarginine (ADMA), a naturally occurring chemical found in blood plasma. It is formed by methylation of arginine residues in proteins and released after proteolysis. ADMA is an endogenous inhibitor of all isoforms of nitric oxide synthase, the enzyme that synthesizes nitric oxide from arginine. Elevated plasma concentrations of ADMA are associated with hypertension and other risk factors for cardiovascular disease. It is known, that chronic kidney disease (CDK) is associated with increased risk of renal and cardiovascular events and it has been claimed that asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), are contributing factors. Nevertheless, the recent comprehensive analysis of methylarginines in a cohort of patients with non-dialysis CKD have revealed, the potential pathophysiological role of SDMA in CKD progression and atherosclerotic cardiovascular disease among non-dialysis CKD patients. Thus SDMA predicts CKD progression and future atherosclerotic cardiovascular events more consistently than other methylarginines. In addition, was also shown, that the maternal plasma ADMA concentration is an important indicator of fetal growth restriction in women with impaired placental perfusion independent of NO.

7-Oxocholesterol (7-Ketocholesterol) is a major oxidation product of cholesterol (oxysterol) found in human atherosclerotic plaque and is more atherogenic than cholesterol in some animal studies. Oxysterols (oxygenated forms of cholesterol) are present at low levels in the circulation and accumulate is plasma and tissues in some pathologies. In atherosclerotic lesions, 7-oxygenated oxysterols, predominantly 7-ketocholesterol, accumulate and have been implicated in the pathology of the disease. There is some in vivo and in vitro evidence that sterol 27-hydroxylase acts on 7-ketocholesterol to initiate its degradation to more polar, water-soluble products. Recent studies indicate an alternative mechanism, in which 7-ketocholesterol is reduced to 7 beta-hydroxycholesterol by 11 beta-hydroxysteroid dehydrogenase type 1. 7-Ketocholesterol can inhibit cholesterol 7 alpha-hydroxylase, the rate-limiting step in bile acid biosynthesis, as well as strongly inhibiting HMG-CoA reductase, the rate-limiting enzyme in cholesterol biosynthesis. It has even been suggested that 7-ketocholesterol is formed enzymically as an endogenous regulator of cholesterol biosynthesis. However, when tested as a pharmacological cholesterol-lowering agent, inhibition of HMG-CoA reductase was rapidly overcome and the 7-ketocholesterol metabolised. In vitro, 7-ketocholesterol has wide-ranging and potent effects, most of which have the potential to contribute to atherosclerosis. For example, 7-ketocholesterol can be cytotoxic and can induce apoptosis in vascular cells. These effects, either individually or more likely, in combination, all implicate 7-ketocholesterol in the initiation and development of atherosclerosis, but further work is needed to establish whether or not its role is a direct causal one. 7-Ketocholesterol is the second most abundant oxysterol found in human atherosclerotic plaque, after the enzymically formed 27-hydroxycholesterol (cholest-5-ene-3beta,27-diol). 7-Ketocholesterol differs from cholesterol by a ketone functional group present at the 7-position. It is produced from cholesterol via the epimeric cholesterol 7-hydroperoxides (cholest-5-ene-3beta-ol-7-hydroperoxide) which decompose to the epimeric 7-hydroxycholesterols (cholest-5-ene-3beta,7-diol) and 7-ketocholesterol. 7-Ketocholesterol is a major dietary oxysterol. It has also been widely suggested that 7-ketocholesterol present in atherosclerotic tissue may be derived from the diet. Certainly, 7-ketocholesterol is a major oxysterol found in cholesterol-rich processed foodstuffs. Dietary 7-ketocholesterol is rapidly metabolised by the liver to 7beta-hydroxycholesterol (cholest-5-ene-3beta,7beta-diol), unusual bile acids and perhaps even cholesterol itself. Its conversion to 7beta-hydroxycholesterol is well documented.