Thus, by a variety of mechanisms arsenate leads to an impairment of cell respiration and subsequently diminished ATP formation. This is consistent with observed ATP depletion of exposed cells and histopathological findings of mitochondrial and cell swelling, glycogen depletion in liver cells and fatty change in liver, heart and kidney. Experiments demonstrated enhanced arterial thrombosis in a rat animal model, elevations of serotonin levels, thromboxane A[2] and adhesion proteins in platelets, while human platelets showed similar responses. The effect on vascular endothelium may eventually be mediated by the arsenic-induced formation of nitric oxide. It was demonstrated that +3 As concentrations substantially lower than concentrations required for inhibition of the lysosomal protease cathepsin L in B cell line TA3 were sufficient to trigger apoptosis in the same B cell line, while the latter could be a mechanism mediating immunosuppressive effects. Kinetics
The two forms of inorganic arsenic, reduced (trivalent As(III)) and oxidized (pentavalent As(V)), can be absorbed, and accumulated in tissues and body fluids. In the liver, the metabolism of arsenic involves enzymatic and non-enzymatic methylation; the most frequently excreted metabolite (≥ 90%) in the urine of mammals is dimethylarsinic acid or cacodylic acid, DMA(V). Dimethylarsenic acid is also known as Agent Blue and was used as herbicide in the American war in Vietnam. In humans inorganic arsenic is reduced nonenzymatically from pentoxide to trioxide, using glutathione or it is mediated by enzymes. Reduction of arsenic pentoxide to arsenic trioxide increases its toxicity and bio availability, Methylation occurs through methyltransferase enzymes. S-adenosylmethionine (SAM) may serve as methyl donor.
Benign Rolandic epilepsy or benign childhood epilepsy with centrotemporal spikes (BCECTS) is the most common epilepsy syndrome in childhood. Most children will outgrow the syndrome (it starts around the age of 3–13 with a peak around 8–9 years and stops around age 14–18), hence the label benign. The seizures, sometimes referred to as sylvian seizures, start around the central sulcus of the brain (also called the centrotemporal area, located around the Rolandic fissure, after Luigi Rolando). Signs and symptoms
The cardinal features of Rolandic epilepsy are infrequent, often single, focal seizures consisting of:
a. unilateral facial sensorimotor symptoms (30% of patients)
b. oropharyngolaryngeal manifestations (53% of patients)
c. speech arrest (40% of patients), and
d. hypersalivation (30% of patients)Hemifacial sensorimotor seizures are often entirely localised in the lower lip or spread to the ipsilateral hand. Motor manifestations are sudden, continuous or bursts of clonic contractions, usually lasting from a few seconds to a minute. Ipsilateral tonic deviation of the mouth is also common. Hemifacial sensory symptoms consist of unilateral numbness mainly in the corner of the mouth. Hemifacial seizures are often associated with an inability to speak and hypersalivation:
The left side of my mouth felt numb and started jerking and pulling to the left, and I could not speak to say what was happening to me. Negative myoclonus can be observed in some cases, as an interruption of tonic muscular activity
Oropharyngolaryngeal ictal manifestations are unilateral sensorimotor symptoms inside the mouth.