The in vitro antiviral activity as well as the mechanism of action of a new antiviral agent, a kanamycin analogue, 1-N-pentadecanoyl-3''-N-trifluoroacetyl kanamycin A (PTKA) against herpes simplex virus type 2 (HSV-2) was investigated. The drug showed excellent antiviral action with negligible cytotoxic effect on the culture cells. Based on plaque reduction assays the 50% inhibitory dose (ID50) of the drug was 1 microgram/ml, and at 20 micrograms/ml plaque formation was totally suppressed. The compound inhibited viral protein synthesis in infected cells without affecting RNA and DNA synthesis, when added to the cultures after virus adsorption. Moreover, pretreatment of the cells with PTKA before HSV-2 infection, increased the antiviral activity significantly. Dot-blot hybridization analysis revealed that the drug reduced the level of immediate early viral mRNA if applied before infection. There was no detectable action at the level of virus adsorption, penetration or uncoating. These results indicate that PTKA exerted its antiviral action at the early stage of viral replication as well as at the level of viral protein synthesis.

Animals↗

PubMedDate not supplied

Epidemiology of acute childhood encephalitis. Aichi Prefecture, Japan, 1984-90.

The case records for 256 patients with acute encephalitis, including meningoencephalitis, acute encephalopathy and Reye syndrome, were obtained from 36 departments of pediatrics in large hospitals through questionnaires which were sent in 1990-92. The incidence rate per 100,000 child years was 3.3, and was more frequent in children aged 0-4 years (rate 6.6) than 5-15 years (rate 2.0), with statistical significance. The disease in the 105 etiologically diagnosed patients was due to measles virus (24), herpes simplex (21), rubella (24), and other agents (36), including two cases of human herpesvirus 6. A third of the infants with measles encephalitis were first seen at less than 18 months of age. Eighteen cases of rubella encephalitis occurred during an epidemic of rubella in Aichi Prefecture, 1987-88. The short-term outcome (mean length of follow-up: 2 years 3 months) of encephalitis was death in 20 cases (7.8%) and sequelae in 58 (24%). Eleven patients died within 7 days and five by the 8-14th day from onset. Thirty-six children had multiple residual impairments, including twelve who were severely handicapped. The prognosis for both life and sequelae was significantly poor for herpes simplex encephalitis in etiologically diagnosed patients. We stress the importance of an increase in the vaccination rate and the establishment of an early diagnostic system.

Adolescent↗

PubMedDate not supplied

Pigmented median raphe cysts of the penis.

Two cases of median raphe cysts of the penis with melanosis are presented. The presence of melanocytes was observed in the lining of the cysts by light and electron microscopy. The possible mechanism of the embryological development of the cysts is discussed in the context of the published literature.

Child, Preschool↗

PubMedDate not supplied

Vidarabine therapy for severe chronic active Epstein-Barr virus infection.

PURPOSE: Severe chronic active Epstein-Barr virus infection (SCAEBV) is an intractable disease with a poor prognosis, and a definitive treatment has not been established. We administered vidarabine to patients with natural killer (NK) cell-type SCAEBV and evaluated clinical and virologic effects. PATIENTS AND METHODS: Four patients with SCAEBV were enrolled in this study. These patients had various symptoms, including fever, chronic hepatitis, hepatosplenomegaly, and hypersensitivity to mosquito bites. All patients had increased numbers of NK cells in their peripheral blood, and most of these were infected with EBV. Viral load was measured by in situ hybridization and quantitative polymerase chain reaction (PCR). RESULTS: The patients all responded to the therapy, and their symptoms improved. After the therapy, the number of NK cells in their peripheral blood decreased. In two patients who were closely monitored, the viral load measured by in situ hybridization and quantitative PCR decreased in parallel with the symptomatic improvement. After discontinuing this drug, the patient's symptoms returned and the Epstein-Barr virus load increased again. CONCLUSION: These results indicate that vidarabine therapy is a therapeutic choice to control SCAEBV, although its effect may be transient.

Adolescent↗