Central Pitting of Molluscum Contagiosum

Histological examination of 42 early lesions of molluscum contagiosum was performed. At the top of the molluscum papule, the epidermis cylindrically hung down into the dermis, thus forming an epidermal cylinder with a narrow canal. Acanthomatous change occurred at the bottom of the epidermal cylinder. Thirteen of the 42 molluscum lesions showed a direct connection with components of hair follicle. It is suggested that the central pitting of molluscum contagiosum may be the ostium of pilar infundibulum.     

Sulphhydryl and disulphide stainings of subepidermal hyaline bodies

The localization of sulphhydryl (-SH) groups and disulphide (-S-S-) bonds in subepidermal hyaline bodies was examined using histochemical techniques with the specific fluorescent thiol reagent (DACM). In lichen planus, hyaline bodies showed -S-S- but not -SH staining, suggesting that erythematosus and dermatomyositis, there were not only -S-S-positive hyaline bodies, considered of epidermal origin, but also -S-S- negative ones. The latter may consist of dermal components, since no dermal components are stainable with DACM. DACM staining therefore seems to be of help in determining the origin of hyaline bodies.     

Transient anuria requiring nephrostomy after intravesical bacillus Calmette-Guérin instillations for superficial bladder cancer

A 76-year-old man received intravesical bacillus Calmette-Guérin (BCG) instillations for recurrent superficial bladder cancer. He had undergone right nephroureterectomy for right renal pelvic cancer 9 months previously. He presented with anuria and left hydronephrosis after the fourth instillation, with serum creatinine increasing up to 15.7 mg/dL. Percutaneous nephrostomy was indwelled, and antegrade pyelography showed left vesicoureteral obstruction. There was no sign of recurrent bladder cancer or ureteral cancer. He started spontaneous voiding on day 4 and the nephrostomy was removed on day 8. Most of the side-effects of intravesical BCG therapy are minor, and major adverse reactions are rare. Life-threatening ureteral obstruction would be a rare complication of BCG immunotherapy. Although BCG intravesical instillation after nephroureterectomy is a common practice, special care should be taken of renal function in patients with unilateral kidney during BCG therapy.     

Effects of caffeine on event-related potentials: Comparison of oddball with single-tone paradigms

We investigated the acute effects of caffeine (500 mg) on event-related potentials (ERP) in 10 healthy subjects using standard oddball and single-tone paradigms. Event-related potentials were recorded before oral ingestion of caffeine or placebo and 30 min and 210 min after. The oddball paradigm, but not the single-tone paradigm, showed that the P300 amplitude and the area were significantly increased 30 min after ingestion of caffeine and significantly decreased 30 min after ingestion of placebo. The effects of caffeine disappeared at 210 min. Neither the P300 latency nor the reaction time changed significantly with the oddball paradigm. However, the reaction time was shortened 30 min after ingestion of caffeine with the single-tone paradigm. These findings suggest that the caffeine-induced increase in the P300 amplitude may have resulted from the increased allocation of attentional resources to the discriminating process which was not, however, accompanied by facilitation of the process and that caffeine may specifically stimulate the discriminating process involved in the oddball paradigm. In addition, the simple psychomotor performance of button-pressing in response to a tone signal was accelerated by caffeine.