[Alphaherpesvininae--dermatology]

The subfamily alphaherpesuvirinae contains herpes simplex virus(HSV) and varicella-zoster virus(VZV) in the Dermatology. HSV infectious diseases are herpetic gingivostomatitis, herpes labialis, facial herpes simplex, Kaposi's varicelliform eruption, genital herpes, lumbosacral herpes simplex, and herpetic whitlow. The primary form of VZV infection is varicella, and the reactivation form is herpes zoster. These infectious diseases in the dermatological clinics usually occur in adult. In this paper we mention clinical manifestations and treatment.

[Transplantation associated alpha herpes virus infection]

Immunosuppression after organ or bone marrow transplantation changes its severity with the time lapse. After bone marrow transplantation, HSV infection occurs in early period and VZV infection, in intermediate period. Aciclovir prophylaxis is effective for preventing HSV in early period and also for elevating the compliance of drug intake. It delays onset of VZV infection on the other hand. VZV infection is usually very severe if it is occurred early, before 100 days after transplant. There was some case of VZV infection with severe abdominal pain without any skin involvement. The incidence of VZV infection in bone marrow recipients was 29%. Even in stable period it caused considerable mental problems in some patient.

[Alpha herpes virus and facial palsy]

Alpha herpes virus is the major causes of peripheral facial palsy such as Bell's palsy or Ramsay Hunt syndrome. Ramsay Hunt syndrome is caused by varicella zoster virus (VZV) infection, and can be diagnosed by facial nerve paralysis associated with herpetic eruption on the pinna, and complication of by vestibulo-cochlear dysfunction. On the other hand, Bell's palsy presents only facial palsy and its diagnosis is made by the exclusion of known conditions. The causes of Bell's palsy had been unknown for many years, however, recently it was revealed that herpes simplex type 1 was the major cause of Bell's palsy by PCR. Because early treatment with acyclovir and prednisone was proven to be effective, we should make efforts to diagnose these diseases as early as possible.

Clinical disease associated with simian agent 8 infection in the baboon

Simian agent 8 (SA8) is an alphaherpesvirus that was first reported as a spontaneous natural infection in a captive baboon colony in 1988. It was first isolated from an African vervet monkey in 1958 and was classified as a simian agent. Simian agent 8 was later isolated from a baboon rectal swab specimen in 1969 and from an oral lesion in a vervet monkey in 1972. Restriction endonuclease analysis was used to identify the virus as SA8. In a 1-year period, 70 baboons housed in two outside 6-acre breeding corrals developed lesions principally on the genitalia and oral cavity. The incidence was the same for males and females, with recurrence rate, severity of the lesions, and duration for the lesions to resolve being greater in the female baboons. Lesions involving the mouth, tongue, and lips were most commonly observed in the juvenile population. The lesions tended to start as small multiple papules or vesicles, which advanced to large pustular or ulcerative areas. Using an every-other-day treatment regimen consisting of Nolvasan cleaning and procaine penicillin G injections, it took an average of 14 to 21 days for the lesions to resolve totally. Thirty-seven percent of the baboons with herpetic lesions experienced another episode of SA8 infection, usually within 1 year of development of the primary lesion. Several complications have been documented to be associated with SA8 infections. Partial or total vaginal obstruction is most common, leading to impaired breeding performance and pyelonephritis. A vaginal corrective surgical procedure has been developed to allow these females to return to productive breeding status within the colony. Penile urethral obstruction, also causing pyelonephritis, was observed in the male baboons. A case of sciatic neuritis was reported in a baboon that presented with self mutilation of the foot; viral isolation revealed the etiologic agent to be SA8. Four female baboons with chronic SA8 infections went on to develop perineal neoplasms. This is an economically important disease entity in captive baboons because it causes severe morbidity, decreased reproductive performance, and ultimately death in 1% of the baboon colony each year. The baboon is a promising animal model in which to study genital herpes as it relates to disease in human beings.

New therapeutic approaches to the alphaherpesvirus infections

The character of diseases caused by alphaherpesviruses has changed over the last decade. The severity of disease and the frequency of acyclovir resistance has increased with the increase in the number of immunocompromised patients. Compounding the trend towards more virulent herpes disease is the current emphasis towards outpatient management of many diseases. Much of the current antiviral research focuses on providing drugs with (i) improved oral bioavailability and pharmacokinetics which permit less frequent oral or topical dosing for suppressive treatment of herpes simplex virus (HSV) infections, (ii) different mechanisms of action for synergic effects in treating resistant HSV infections in the immunocompromised host and (iii) improved efficacy. Future antiviral agents will probably target enzymes or viral factors essential for infection or will inhibit other steps in the viral infection cycle, such as viral entry, protein synthesis or capsid assembly. Medications that augment the immune response constitute another pathway for combating herpes viral infections. Many of the newer experimental agents target essential processes unique to herpesvirus replication and, therefore, potentially have high selectivity.

Cloning and sequence analysis of a Marek's disease virus origin binding protein (OBP) reveals strict conservation of structural motifs among OBPs of divergent alphaherpesviruses

Marek's disease virus (MDV) is a highly cell-associated avian herpesvirus. In its natural host, MDV induces Marek's disease (MD), a lethal condition characterized by malignant lymphoma of T cells. Although symptoms of MD may be prevented by vaccination, no practical pharmacological method of control has been widely accepted. Viral replication represents a point at which pharmacological control of herpesvirus infection may be most successful. However, this requires detailed knowledge of viral replication proteins. Studies in HSV-1 DNA replication implicate the UL9 protein as a key initiator of replication. For example, binding of UL9 to HSV-1 origins is a prerequisite for assembly of additional replication proteins. In this study, a protein, whose apparent molecular size is similar to that of HSV-1 UL9, was identified in extracts of MDV infected cells by western blot analysis with anti-HSV-1 UL9 antibody. A putative MDV UL9 gene was subsequently identified through sequencing of MDV genome fragments (BamHI G and C). Extended DNA sequence analysis revealed an open reading frame (ORF) which could encode a protein homologous to HSV-1 UL9. The MDV UL9 ORF encodes 841 amino acids, producing a sequence 49% identical to HSV-1 UL9 and 46% identical to VZV gene 51 product (VZV UL9). MDV UL9 shares numerous structural motifs with HSV-1 and VZV UL9 proteins, including six conserved N-terminal helicase motifs, an N-terminal leucine zipper motif, a C-terminal pseudo-leucine zipper sequence, and a putative helix-turn-helix structure.