Immunogenic and protective response in mice immunized with a purified, inactivated, Dengue-2 virus vaccine prototype made in fetal rhesus lung cells.

The feasibility of a purified, inactivated vaccine (PIV) against dengue type 2 (DEN-2) virus was explored. Dengue-2 virus strain 16681 was used for producing a monotypic PIV. Virus adapted to fetal rhesus lung (FRhL-2) cells was harvested from roller bottle culture supernatant fluids, concentrated, and purified on sucrose gradients. Analysis of purified virus preparations by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting showed primarily envelope (E) and premembrane (prM) antigens. These preparations had a purity, estimated from silver-stained gels, of approximately 70%, and a yield, based on recovery of virus and viral antigen, of 10-20%. The purified virus was inactivated with 0.05% formalin at 22 degrees C, or alternatively, with 7 mRads from a 60Co source. Vaccinated mice developed high titers of anti-DEN-2 virus neutralizing antibody and were partially protected from virus challenge. These results warrant further testing and development of PIVs for the other DEN virus serotypes.

Influence of L-DOPA/carbidopa on pattern reversal VEP: behavioural difference in primary and secondary parkinsonism.

Data obtained from a total of 246 monocular VEPs performed on 46 patients, 35 with Parkinson's disease and 11 with arteriosclerotic parkinsonism, classed in the first 3 stages on the Hohen and Yahr disability scale, are reported. Our data show a delay of mean P100 latency in the primary parkinsonian group during the period of washout from L-DOPA therapy as well as in the secondary parkinsonian group. But the interocular mean difference in VEP P100 results significantly increased in primary parkinsonism only. A more important different behaviour between primary and secondary parkinsonism concerns a possible reduction of VEP delay related to L-DOPA/carbidopa treatment. An improvement of P100 delay can be noticed after acute and after chronic DOPA therapy in primary parkinsonism only. The above data confirm previous reports concerning VEP delays in Parkinson's disease, suggesting monitoring of different pharmacological sensitivity in idiopathic and arteriosclerotic parkinsonian patients as a useful method.

Brainstem auditory evoked potential (BAEP) abnormalities in subjects with craniovertebral malformations.

We report the data on 42 monaural BAEP recordings from 10 patients with craniovertebral malformations. Of 8 preoperative recordings from 3 patients 6 showed an increased I-III interpeak latency (IPL). Of 28 recordings taken shortly (1-12 months) after surgery 21 showed an abnormal I-III IPL. On the other hand, of 6 recordings from 3 patients 20 years after surgery 5 were in the normal range and 1 showed an abnormal I-III IPL. Although the most important site of craniovertebral malformations is the cervicomedullary junction, the results reported suggest unilateral or asymmetrical bilateral involvement of the medullary-pontine junction, on the evidence of BAEP wave III, in a large proportion of patients with these malformations.

Cephalic and noncephalic references in brain stem-evoked potential recording.

55 controls were studied to investigate the morphology of brain stem evoked potential, utilizing variable electrode arrays. In a first series the active electrodes placed at Cz and subocciput (SO) were referred to the linked earlobes. In a further 15 recording sessions, Cz, SO and A1A2 were connected to a noncephalic (hand) electrode. In the former array there was a reversed and depressed Vth wave in 95% of the cases at SO, while in the latter the peaks were phase and time-locked at all the recording sites coupled to a depressed IV-V complex from SO and A1A2 in respect to Cz.

Foveal versus peripheral retinal responses: a new analysis for early diagnosis of multiple sclerosis.

Visual potentials evoked by brief flashes (VEPs) were recorded in 85 patients with MS, 30 healthy controls and 25 neurological patients without demyelinating diseases. In a group of 44 patients, diffuse field stimulation was used, resutling in 15 altered responses (34%). In a second group of 41 patients with superimposable characteristics including age, sex, diagnosis of MS (definite, probable and possible) and score on the Rose's scale, the separate responses of central and peripheral retina were analysed. A total of 30 abnormal VEPs were recognized (73%) with the following distribution: 16 foveal VEPs (78%), 4 peripheral responses (13%) and 26 centreperiphery latency differences (CPLD, 60%). Twenty subjects of Group A with normal or slightly altered full field VEPs were retested with both stimulating methods with the following result: 3 altered full field VEPs (15%) and 15 abnormal CPLD (75%). With diffuse field stimulation, the correlation between the VEP scores and the results of other examinations (visual, pyramidal, etc.) were insignficant; on the contrary, the CPLD was clearly correlated with the involvement of the visual and other systems in the fluctuating clinical course of MS.