Regulation of type I collagen and interstitial collagenase mRNA expression in human dermal fibroblasts by colchicine and D-penicillamine

Sclerosis is a disease process in which idiopathic hardening occurs in the skin and/or internal organs as a result of the accumulation of type I collagen, induced mainly by transforming growth factor-beta. Colchicine and D-penicillamine are widely used for its treatment. Their effects are known to be due to post-translational down-regulation of type I collagen synthesis, with colchicine also up-regulating interstitial collagenase. To determine whether or not they have any pre-translational effect on type I collagen and MMP-1, and also to observe their effects on the action of TGF-beta, cultured neonatal foreskin fibroblasts were treated with colchicine and D-penicillamine, singly and together. The amount of type I collagen and MMP-1 mRNA were quantitated by Northern blot hybridization. Colchicine suppresses the basal level of type I collagen mRNA but minimally stimulates the mRNA expression of MMP-1, whereas D-penicillamine does not have any significant effects on either. Colchicine was also able to significantly suppress the TGF-beta-induced up-regulation of type I collagen mRNA expression.

Role of nitric oxide and superoxide in Giardia lamblia killing

Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO) donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine). Activated macrophages were cytotoxic to Giardia trophozoites (~60 per cent dead trophozoites). This effect was inhibited (>90 per cent) by an NO synthase inhibitor (200 muM) and unaffected by superoxide dismutase (SOD, 300 U/ml). Giardia trophozoites were killed by the NO donors S-nitroso-acetyl-penicillamine(SNAP)and sodium nitroprusside (SNP) in a dose-dependent manner (LD50 300 and 50 muM, respectively). A dual NO-superoxide anion donor, 3-morpholino-sydnonimine hydrochloride (SIN-1), did not have a killing effect in concentration up to 1 mM. However, when SOD (300 U/ml) was added simultaneously with SIN-1 to Giardia, a significant trophozoite-killing effect was observed (~35 per cent dead trophozoites at 1 mM). The mixture of SNAP or SNP with superoxide anion, which yields peroxynitrite, abolished the trophozoite killing induced by NO donors. Authentic peroxynitrite only killed trophozoites at very high concentrations (3 mM). These results indicate that NO accounts for Giardia trophozoite killing and this effect is not mediated by peroxynitrite.

Spectrophotometric determination of penicillamine

Spectrophotometric determination of penicillamine was achieved through its oxidation to penicillamine acid, using excess cerric ammonium sulfate in presence of i.m. sulfuric acid at room temperature for one hour. The amount of cerric equivalent to penicillamine is determined by measuring the absorbance of the blank against the experiment at 317 nm. Beer's law is obeyed over a concentration range of 48-288 mug% of penicillamine with mean percentage recovery of 99.80 +/- 0.565. The stoichiometry and the products of the reaction were studied as well as the mechanism of the reaction is presented. The method was applied to Artamin capsules and its validity was ascertained by st and ard addition technique. The proposed method is sensitive, accurate and precise as compared with the official method

Miastenia gravis inducida por D-Penicilamina. Presentación de un caso y revisión de la literatura / D-penicillamine induced miastenia gravis

La asociación entre miastenia gravis y D-penicilamina ha sido reportada en pacientes que recibían esta droga por presentar artritis reumatoidea, enfermedad de Wilson, esclerodermia o cistinuria. El cuadro es indistingible, clínica y electrofisiológicamente, de la miastenia gravis de aparición espontánea; solo se puede diferenciar por la mejoría clínica y por la caída del título de anticuerpos antirreceptor colinérgico luego de la suspensión del tratamiento con D-penicilamina. El mecanismo de inducción de los anticuerpos antirreceptor colinérgico en esta enfermedad es desconocido. Reportamos una paciente de 55 años de edad que padece artritis reumatoidea, que a los doce meses de ser tratada con D-penicilamina, presentó un cuadro de ptosis palpabral bilateral, diplopía, disartría, disfagia y debilidad en los miembros superiores. Ante la sospecha de miastenia gravis se realizaron: prueba de tensilon (edrofonio), electromiograma con estimulación repetitiva y dosaje de anticuerpos antirreceptor colinérgico, que confirmaron este diagnóstico. Al poco tiempo de suspender la D-penicilamina, e iniciar el tratamiento con piridostigmina la paciente mejoró, no requiriendo más esta última medicación.

Tissue sensitivity to acetylcholine, adrenaline, noradrenaline and serotonin and agents acting on sulphydryl groups.

Parachloromercury benzoate (PCMB), a sulphydryl inactivator, caused a progressively increasing inhibition of tissue responses to acetylcholine, adrenaline, noradrenaline and serotonin in vitro. This inhibition was progressively and completely reversed by penicillamine, a sulphydryl activator. It is inferred that intact sulphydryl groups are essential for constancy of responses of excitable tissues to the neurotransmitters.