Zidovudine and interferon therapy for adult T-cell leukaemia/lymphoma: results of a preliminary study at UHWI-Mona

Seven patients with adult T-cell leukaemia/lymphoma(ATL) were treated with a combination of zidovudine (AZT) and interferon after failed chemotherapy. One patient showed a major response for nine months. The remainder showed progressive disease further complicated by drug toxicity. The poor responses could be explained by patient selection, since most patients had advanced disease refractory to chemotherapy. A larger more protracted study is required for further evaluation of this treatment option. (AU)

Comparison of two human pathogenic strains with a commensal strain of Herpes Simplex virus isolated at the University Hospital of the West Indies

Comparision has been made between two human "neuropathogenic" and one "commensal" strains of herpes simplex virus. These terms are assigned to these viruses on the basis of their origin. The first two were related from patients with encephalitis and the third from a benign recurrent lesion. A number of physiochemical characteristics of these three strains were studied. The major differences observed between the "pathogens" and the "commensal" virus are: 1. The ability of the commensal herpes virus to infect adult mice while the pathogenic herpes could not. 2. The commensal herpes virus could not be neutralized by the hyperimmune sera of the pathogenic herpes and vice versa, although all crossreacted in complement fixation tests. 3. The commensal virus was significantly inactivated by chloroform, while the pathogens were not significantly affected under the same conditions. 4. Freezing and thawing followed by differential centrifugation rendered the commensal herpes vulnerable to inactivation of DNAse. Inactivation of the pathogens by this enzyme could only be acheived after chromatography on the anion exchanger, Diethyl aminoethyl. 5. The absorbtion spectrum gave a maximum peak at wave lenghts between 260-270 mu for the pathogenic virus. The peak absorption of the commensal herpes was at 280 mu. The peak at 260-270 mu by the pathogens is most likely due to the presence of nucleic acid. The peak absorption of the commensal virus is similar to that given by a typical protein. The relatively high concentration of protein which accompanies the commensal virus might account for the behaviour of this virus. 6. The "pathogenic" and "commensal" strains could be distinguished with respect to susceptibility to interferon. The commensal strain being more susceptible and also more effective in inducing interferon synthesis. 7. The method of comparision used in this investigation, and the results which reflect the marked difference between the strains of herpes simplex studied here produce some methods which may be used for differentiating between pathogenic and commensal strains of herpes simplex virus. It would appear that the methods used here are valuable to the study of viral genetics and the physiochemical study of herpes viruses. Evidence has been presented to show that there is molecular structural difference between the pathogenic and the commensal strains of herpes simplex virus. Such a difference or such differences may provide tools to probe into the pathogenic physiology of infected cells, or help to elucidate the factors responsible for neurotropicity and commensalism in herpes virus. The author is convinced that the differences cited above are genetically based. However, until further investigations are carried out, it is a subjective choice whether to consider the differences as sufficient basis for the subgrouping of herpes simplex virus. No claim is made that the distinction cited are attributes of other strains associated with encephalitis or limited lesions of recurrent herpes (AU)

The chemotherapy of viral infections

Only methisazone and amantadine of the synthetic antiviral agents are commercially available for general use, and they are used only prophylactically. Interferon inducers are promising but as yet untested in man. No doubt effective chemotherapeutic agents will in time become available but for the present and immediate future, vaccines will provide the first line of defence against disease. Methods of immunization are bound to improve and with an increasing awareness of public health measures the role of antiviral chemotherapeutic agents though important, will be minor. (Summary)