Neuroblastoma cell fusion by a temperature-sensitive mutant of vesicular stomatitis virus.

A temperature sensitive mutant of vesicular stomatitis virus which does not mature properly when grown at 39°C promoted extensive fusion of murine neuroblastoma cells at this nonpermissive temperature. Polykaryocytes apparently formed as a result of fusion from within the cells that requires low doses of infectious virions for its promotion and is dependent on viral protein synthesis. Although 90% of infected N-18 neuroblastoma cells were fused by 15 h after infection, larger polykaryocytes continued to form, leading to an average of 28 nuclei per polykaryocyte as a result of polykaryocytes fusing to each other. Two neuroblastoma cell lines have been observed to undergo fusion, whereas three other cell lines (BHK-21, CHO, and 3T3) were incapable of forming polykaryocytes, suggesting that nervous system-derived cells are particularly susceptible to vesicular stomatitis virus-induced fusion. Although the normal assembly of the protein components of this virus is deficient at 39°C, the G glycoprotein was inserted into the infected cell membranes at this temperature. Two lines of evidence suggest that the expression of G at the cell surface promotes this polykaryocyte formation: (i) inhibition of glycosylation, which may be involved in the migration of the G protein to the cellular plasma membranes, will inhibit the cell fusion reaction; (ii) addition of antiserum, directed toward the purified G glycoprotein, will also inhibit cell fusion

Síndrome de Ekbom acompanhada de automutilação Ekbom's syndrome followed by self-mutilation

O delírio parasitário (ou síndrome de Ekbom) é uma condição rara, onde o paciente apresenta uma forte convicção de que está infestado por pequenos parasitas ou organismos. Muitas vezes, os delírios são tão intensos que levam esses pacientes à automutilação. Relatamos aqui um caso de um senhor de 67 anos, isolado socialmente, solteiro, apresentando delírio parasitário em região perineal, culminando em lesões por automutilação.<br>Delusional parasitosis (or Ekbom's syndrome) is a rare condition, in which the patient has a strong conviction that he or she is infested by small parasites or organisms. These delusions are often so intense that they lead the patient to self-mutilation. We report a case of a 67-year-old man, socially isolated, single, with delusional parasitosis in the perineal area, culminating in self-mutilation lesions