Transient Manifestation of Antegrade Conduction Over a Kent Bundle After Ventricular Pacing

Postventricular Pacing Preexcitation. Antegrade conduction over a Kent bundle was transiently manifested after the cessation of ventricular overdrive pacing in two patients; otherwise, the heart behaved as if it had a concealed accessory pathway. Conventional electrophysiologic study suggested either a longitudinal dissociation of an accessory pathway or closely located double accessory pathways. The mechanism of the transient manifestation of ventricular preexcitation was discussed. (J Cardiovasc Electrophysiol, Vol. 3, pp. 423–430, October 1992)     

A Clinical Trial of Topical Bleaching Treatment with Nanoscale Tretinoin Particles and Hydroquinone for Hyperpigmented Skin Lesions

BACKGROUND: Although combined use of tretinoin (all-trans-retinoic acid; atRA) and hydroquinone improves various hyperpigmented lesions, the pharmacologic instability of atRA and atRA-induced irritant dermatitis are difficult unsolved problems. OBJECTIVE: The objective was to evaluate the efficacy and adverse effects of a newly formulated gel containing inorganic-coated atRA nanoscale particles (nano-atRA gel). METHODS: Nano-atRA gel was used in our two-phased bleaching protocol: 5% hydroquinone and 7% lactic acid ointment were used along with nano-atRA gel in the bleaching phase (2-8 weeks), and 5% hydroquinone and 7% ascorbic acid ointment were used alone during the healing phase (4-8 weeks). Eighty-four patients with facial hyperpigmented lesions were enrolled in this study, and 77 of them (88 lesions) followed up for more than 10 weeks were analyzed. RESULTS: Hyperpigmentation was improved in 84 of 88 lesions (95.5%) after a mean treatment period of 14.3 weeks and was almost eliminated in 52 lesions (59.1%). Nano-atRA gel caused exfoliation and scaling similar to that seen with conventional atRA gel, whereas the erythema seen in the bleaching phase appeared to be weaker. CONCLUSION: Nano-atRA gel can improve hyperpigmentation to a similar extent as conventional atRA gel. It also induces irritant dermatitis, but with less erythema.     

Chemical modification of superoxide dismutase Extension of plasma half life of the enzyme through its reversible binding to the circulating albumin

Protection of organisms from oxidative stress is one of the major prerequisites for aerobic life. Since intravenously injected Cu⁺⁺/Zn⁺⁺ -type superoxide dismutase (SOD) rapidly undergoes renal glomerular filtration and appears in urine in its intact form, its clinical use as a scavenger for superoxide radicals has been highly limited. To test whether reversible interaction of SOD with plasma albumin might decrease the rate of disappearance of the enzyme from the circulation, the lysyl residues of the human erythrocyte-type enzyme were covalently linked with poly-(styrene-co-maleic acid) butyl ester (SMA) via amide linkage. Affinity chromatographic analysis by an albumin-Sepharose column revealed that the enzyme samples labeled with SMA (SMA-SOD) tightly bound to the column, while unmodified SOD was eluted in the unbound fractions. SMA-SOD bound to the column could be eluted by the buffer solution containing 0.1% sodium dodecylsulfate. In vivo analysis revealed that intravenously administered SMA-SOD circulated bound to albumin with an extremely long half-life (6 h), while unmodified SOD rapidly underwent renal glomerular filtration with a plasma half-life of 4min. Thus, SMA-SOD may effectively dismutate superoxide radicals in the circulation.