Collagenous vasculopathy: a report of three cases.

Cutaneous collagenous vasculopathy (CCV) is an idiopathic microangiopathy involving the superficial blood vessels that was initially reported in a 54-year-old male. We recently have identified this rarely reported entity in three Caucasian males. The first patient was a 59-year-old male with diabetes, hypertension and hypercholesterolemia who presented with multiple, red, blanchable, asymptomatic telangiectasias covering the extensor surface of the forearms, the lower abdomen and parts of the chest. The second patient was a 62-year-old male with psoriasis and extensive arthritis who presented with prominent telangiectasias on the left lateral distal thigh with mild overlying epidermal atrophy. The third patient was an 80-year-old male with atrial fibrillation who presented with blanching, telangiectatic areas on the abdomen, thighs and back. Histologically, the skin lesions showed ectatic superficial small blood vessels with laminated, hyalinized concretions around vessels that were highlighted with periodic acid-Schiff staining following diastase digestion and reactive by immunohistochemical staining with an antibody to collagen type IV. CCV is a rare and poorly understood entity with distinct histopathological features that may clinically resemble generalized essential telangiectasia (GET), yet which may affect a different demographic population than GET. Awareness of this uncommon entity may further help to elucidate its etiology.

Methamphetamine-induced spectrin proteolysis in the rat striatum.

Methamphetamine (METH) is a widely abused psychostimulant. Multiple high doses of METH cause long-term toxicity to dopamine (DA) and serotonin (5-HT) nerve terminals in the brain, as evidenced by decreases in DA and 5-HT content, decreases in tyrosine and tryptophan hydroxylase activities, decreases in DA and 5-HT re-uptake sites, and nerve terminal degeneration. Multiple high doses of METH are known to elicit a rapid increase in DA release and hyperthermia. Although METH also produces a delayed and sustained rise in glutamate, no studies have shown whether METH produces structural evidence of excitotoxicity in striatum, or identified the receptors that mediate this toxicity directly, independent of alterations in METH-induced hyperthermia. These experiments investigated whether METH can cause excitotoxicity as evidenced by cytoskeletal protein breakdown in a glutamate receptor-dependent manner. METH increased calpain-mediated spectrin proteolysis in the rat striatum 5 and 7 days after METH administration without affecting caspase 3-dependent spectrin breakdown. This effect was completely blocked with the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, GYKI 52466, but not the NMDA receptor antagonist, MK-801. However, AMPA or NMDA receptor antagonism did not attenuate the METH-induced depletions of the dopamine transporter (DAT). Independent mechanisms involved in mediating spectrin proteolysis and DAT protein loss are discussed.