Herpes simplex virus encephalitis in suckling mice: ultrastructural studies of virus replication.

Ultrastructural studies concerning the replication and release of a neuro-adapted strain of herpes simplex virus were carried out on acutely encephalitic mice. It was found that envelopment of nucleocapsid particles at the nuclear membrane of brain cells was inefficient, resulting in accumulation of unenveloped nucleocapsids in the cell cytoplasm. These nucleocapsids were associated with arrays of microtubules within cytoplasmic processes. Enveloped particles were rarely present in tissur spaces. Those that were seen appeared to be in a state of disintegration. This replication process of herpes simplex virus in the murine encephalitis model differs from that observed in tissue culture cells. The implications of these differences are discussed.

Comparative effects of herpes simplex virus types 1 and 2 in organotypic cultures of mouse dorsal root ganglion.

Mature organized cultures of mouse dorsal root ganglion (MDRG) were infected with herpes simplex virus, type 1 (HSV 1) and type 2 (HSV 2). Onset of infectious virus production occurred faster and reached higher levels in HSV 2-infected cultures. Neurons, supporting cells and myelin were affected in both types of infection, but morphological changes occurred significantly earlier and more dramatically with the type 2 infection. The pattern of myelin changes was distinctly different in the two types of infection. Within 20 hours post infection nerve cells infected with HSV 2 developed several types of intranuclear inclusions consisting of membranes and filaments; no such neuronal inclusions were seen with HSV 1 infection. HSV 2 infection showed frequent, large, membranous inclusions in supporting cell nuclei whereas, only rare, small inclusions of this type were seen in supporting cells infected with HSV 1. The observations demonstrate that the two virus types produced different virus replication patterns and different morphologic changes in long term cultures of MDRG. There appears to be a differential response of neurons and non-neuronal elements to the virus in this tissue substrate. Viral latency was not induced in this system by direct inoculation of the virus under the conditions described.

Latent herpes simplex virus infection of mice. Infectious virus in homogenates of latently infected dorsal root ganglia.

C-57 albino weanling mice were latently infected with herpes simplex virus (Mp strain, type 1) by inoculation of 10(4) plaque forming units in the right hind footpad. The virus was demonstrable in explant cultures of the sacral dorsal root ganglia of these mice for as long as 18 months following inoculation. In addition, the virus was detectable when homogenates of these latently infected ganglia were placed on to differentiated organotypic cultures of fetal mouse dorsal root ganglia for as long as 8 months following inoculation of the mice. Virus was not demonstrable in these homogenates when they were placed on the Hela cells. The results suggest that during herpes simplex virus latent infection in mice there is continuous synthesis of infectious virus, probably in a highly localized area, which is detectable if a sensitive indicator substrate, such as these organotypic cultures, is used.

Herpes simplex virus types 1 and 2 in organotypic cultures of mouse central and peripheral nervous system. I. Light microscopic observations of myelin degeneration.

Mature mouse spinal cord-ganglion cultures, which contain both peripheral and central nervous system as one unit, were infected with herpes simplex virus type 1 (HSV 1) or type 2 (HSV 2) and observed by bright field microscopy for up to 72 hours. There was degeneration of both central and peripheral myelin in cultures infected with either virus, but the pattern of peripheral myelin degeneration associated with HSV 1-infected cultures was differrnt from that in HSV 2-infected cultures. Type 1 was charcterized by focal dilatations; type 2 by "sausage-shaped" swellings, and the cytopathic effect of HSV 2 both began (6 hours p.i.) and was completed (36 hours p.i.) earlier than in cultures infected with HSV 1 (12 hours and 48 hours p.i. respectively). In central nervous tissue, the apperance of degenerating myelin after infection with HSV 1 was indistinguishable from that in HSV 2-infected cultures, but the rate of myelin loss was greater in cultures infected with the type 2 virus. Evidence is presented which suggests that, at least in the peripheral nervous system,myelin degeneration did not appear to be dependent on neuronal or axonal dysfunction or death, but was a direct result of virus infection.

Further characterization of brain actin by electron microscopy.

The physical state of actin in nerve ending preparations and its relationship to the membranes was studied at the ultrastructural level by negative staining with uranyl acetate before and after treatment with muscle heaving meromyosin (HMM). Actin prepared from synaptosomal or synaptic membrane preparations did not polymerize to fiber formation as readily as striated muscle actin under the same conditions. Treatment of these brain actin preparations with HMM, however, resulted in formation of fibers characteristically decorated with arrowheads which were quite similar to those formed with muscle actin. Treatment of the synaptosomal or synaptic membrane fractions themselves with HMM caused the formation of numerous decorated fibers although fibers were not evident before HMM treatment. This did not occur with the presynaptic vesicle fraction. The studies suggest that at least part of the actin is associated with synaptic membranes and is in a partially polymerized or non-polymerized state; polymerization can be induced by HMM.

Selegiline in the treatment of Parkinson's disease--long term experience.

L-deprenyl (selegiline) has been reported as a safe effective adjunctive agent to levodopa in the control of Parkinson's symptoms, as well as a means of preventing the progressive nature of the disease process. In an ongoing study, now in its 12th year, L-deprenyl has been administered 1. as monotherapy or 2. in combination with levodopa, to previously untreated patients in the early phases of the disease; 3. added to an existing regimen of levodopa when optimal therapeutic results are not being obtained. This report reviews our experience in each of these three treatment categories. Results obtained to date, indicate that L-deprenyl administered alone does not prevent the occurrence of signs of Parkinson's disease. Its administration with levodopa, as initial therapy, allows for use of lower dosage and less side-effects of the latter agent. When L-deprenyl is added to sub-optimal responders to levodopa, it attenuates fluctuating responses, particularly those of the 'end-of-dose' variety.

Nucleic acid homology studies of viral nucleic acids in idiopathic Parkinson's disease.

Reassociation kinetics analyses with radioiodinated herpes simplex type 1 DNA and influenza A/NWS RNA were performed in the presence of tissue nucleic acids from defined loci of the brains of nine patients with idiopathic Parkinson's disease, one normal control brain, and the brains of uninfected mice or mice infected with either herpes simplex type 1 virus or influenza A/NWS virus. Herpes simplex type 1 DNA was detected by an increased reassociation rate in the herpes simplex type 1 virus-infected mouse brains. Influenza A/NWS RNA was detected by reassociation in the influenza A/NWS virus-infected mouse brains. Experimental limits for the detection of homologous nucleic acids are given for each separate experiment with human or mouse tissue. Within these detection limits, nucleic acids complementary to herpes simplex type 1 DNA or influenza A/NWS RNA were not detected in any of the brains of patients with idiopathic Parkinson's disease.

HLA-B14 antigen and postencephalitic Parkinson's disease. Their association in an American-Jewish ethnic group.

Eighteen unrelated American-Jewish patients of Eastern European extraction who had classical postencephalitic Parkinson's disease were typed for HLA-A, HLA-B, and HLA-C antigenic determinants. Compared with 147 ethnically matched controls, the HLA-B14 antigen showed a highly significantly increased frequency in the postencephalitic Parkinson's group (corrected P = .001). This association, though not necessarily reflecting genetic susceptibility to the disease, strongly suggests such a possibility in the pathogenesis of at least this particular variant of parkinsonism.

Early combination of selegiline and low-dose levodopa as initial symptomatic therapy in Parkinson's disease. Experience in 26 patients receiving combined therapy for 26 months.

Thirty-eight patients newly diagnosed as having Parkinson's disease (mean age, 57.3 years; mean Parkinson's disease duration, 2.7 years) in the earlier phase of the disease (mean Hoehn/Yahr stage, 2; mean motor scores, 11.4) were given selegiline (Deprenyl), 10 mg daily, and maintained on this drug alone until significant clinical worsening warranted the addition of low-dose levodopa (Sinemet, 25/100 three to four doses per day). Five of these patients were not yet receiving additional levodopa despite some worsening of motor scores. Of the 33 patients now taking combined therapy, seven have been followed up for 6 months or less. Twenty-four (92%) of the 26 patients taking combined therapy for a mean of 26 months (8.5 to 99 months) who have had Parkinson's disease for 6 years showed a dramatic improvement in their parkinsonism shortly after the addition of levodopa, with significant decreases in their rated motor scores, such improvement being maintained at their latest neurologic evaluation. Eighteen (75%) of these 24 patients responded to the combined selegiline/levodopa therapy with degrees of improvement equal to or greater than 50%, compared with their motor status at the start of combined therapy just before the addition of levodopa. This degree of "reversal" of parkinsonism on addition of levodopa (mean carbidopa/levodopa dose, 98/389 mg) was not observed in any of these same patients receiving selegiline alone for an average of 13.8 months. Four patients taking combined therapy developed mild, transient, abnormal involuntary movements, and end-of-dose pattern of response after more than 2 years of combined therapy (24.75 and 33.5 months, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies against arboviruses in postencephalitic and idiopathic Parkinson's disease.

Serum and CSF from patients with classic von Economo's postencephalitic Parkinson's disease, idiopathic Parkinson's disease and non-Parkinsonian neurological controls were tested for hemagglutination-inhibition antibodies to 17 arboviruses. All 35 CSF specimens from patients with idiopathic Parkinson's disease and controls were negative (ie, no inhibition of hemagglutination) with all the antigens. Of the total of 124 serums from the three study groups, 105 were also negative with all antigens tested. The only positive results were given by 19 serum specimens against one or more of group B arbovirus antigens, and/or against Batai and western equine encephalomyelitis antigens. There were no definitive differences in the distribution of these positive serum titers among controls, idiopathic Parkinson's, and postencephalitic Parkinson's cases. A causal relationship of the arboviruses tested with either the classical postencephalitic or idiopathic Parkinson's disease is not supported by the results of this study.

Organic mental syndrome and confusional states in Parkinson's disease. Relationship to computerized tomographic signs of cerebral atrophy.

Ninety-three patients with a diagnosis of Parkinson's disease, otherwise unselected, were specifically evaluated for organic mental syndrome (OMS) and other neurologic motor signs other than those referrable to extrapyramidal dysfunction; in addition, they had cranial computerized tomography (CT) to measure any structural changes in brain parenchyma. Cortical (sulci) atrophy and ventricular enlargement as CT signs of cerebral atrophy were correlated with different clinical patterns of the disease. An age-adjusted control population, with intact mentation, was similarly studied. The presence of classic OMS in a sizable segment of the usual parkinsonian population was invariably associated with CT signs of cerebral atrophy. Atrophic changes on CT scans, however, were not necessarily correlated with any intellectual dysfunction, or only weakly so, independent of age. The "typical" parkinsonian patients without evidence of OMS were indistinguishable from an age-adjusted control group with regard to structural changes in their scans. However, the parkinsonian patients with definite, permanent OMS and other focal neurologic deficit probably constitute a separate or distinct subset of the parkinsonian population, with a pathologic substrate more likely to be similar to that of the so-called Alzheimer-type dementias. Duration of the parkinsonian syndrome was not predictive of either mental status or scan findings, after adjustment for age as a factor.

Selegiline use to prevent progression of Parkinson's disease. Experience in 22 de novo patients.

To test the hypothesis that selegiline (L-deprenyl), a selective inhibitor of B-type monoamine oxidase, can halt the natural progression of Parkinson's disease, its use in 22 naive patients (mean age, 58 years; mean Parkinson's disease duration, 2.3 years) in the early stages (1 to 2) of the disease was studied. Patients were started and maintained on a daily dose of 10 mg of selegiline, and they underwent neurologic examinations at 3-month intervals using our center's disease staging and total rated disability scores. The criterion set for disease progression was defined as either the appearance of a new objective sign and/or a definite, persistent worsening (greater than 25%) of existing signs after the initiation of the selegiline trial. Patients remained on a regimen of selegiline [corrected] for periods ranging from 7 to 84 months. At the time of their latest neurologic examination, 17 (77%) of the 22 patients had conditions that demonstrably worsened with selegiline alone at an average of 10.8 months from the start of the drug therapy. Six of these 17 patients with worsening conditions (or 27% of the original 22) eventually required the addition of levodopa with carbidopa (Sinemet) on average at 13 months from the start of selegiline therapy; they have continued, to date, taking this combination for an additional mean follow-up period of 20.7 months. Four of the original 22 patients had relatively unchanged, stable neurologic status at the time of their latest examination (average follow-up period, 11.6 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Selegiline as an adjunct to conventional levodopa therapy in Parkinson's disease. Experience with this type B monoamine oxidase inhibitor in 200 patients.

Two hundred patients at a median age of 63 years, receiving conventional levodopa therapy for 8 years, who had had Parkinson's disease for 10 years, tried a regimen of selegiline (L-deprenyl), a type B monoamine oxidase inhibitor, at a daily dose of 10 mg, for varying periods from less than 6 months to more than 24 months (28% over 24 months). Selegiline does improve parkinsonism during the initial 6 months to 12 to 24 months of combined therapy in one third to almost half of patients with an end-of-dose type of response to long-term levodopa therapy. However, even this particular class of patients is unable to maintain such an improvement by 36 months, much less by 48 months, from the start of the selegiline trial. About one quarter of poor responders to levodopa and those with random deterioration show improvement in their parkinsonian status in the first 6 months of the selegiline trial, but their conditions quickly deteriorate by 1 year. The predominant pattern of response to previous levodopa therapy and the severity of the total disability score at the initiation of the selegiline trial were the two variables that were predictive of risk of failure with the drug. No evidence suggested that selegiline decreases the excess mortality rate of Parkinson's disease above that achieved with the use of levodopa alone. Selegiline as an adjunctive agent to conventional levodopa therapy was not unduly impressive with regard to preventing progression of Parkinson's disease.

Serologic studies of MS patients, controls, and patients with other neurologic diseases: antibodies to HTLV-I, II, III.

We have studied the frequency of human retrovirus antibody (HTLV-I, II, III) in the serum and CSF of patients with MS, matched controls, and patients with optic neuritis, idiopathic and postencephalitic Parkinson's disease, neuropathies, polymyositis, ALS, and postpoliomyelitis. Except for the postpoliomyelitis samples, all samples were collected prior to 1980. Contrary to a previous published report, no significant levels of antibody to HTLV-I, II, or III were found in the MS patients or controls. No retrovirus antibody was detected in patients with the other neurologic diseases.

Astrogliosis in von Economo's and postencephalitic Parkinson's diseases supports probable viral etiology.

A marked generalized astrogliosis was observed in the frontal and temporal white matter from a case of von Economo's disease and another of postencephalitic Parkinson's disease, which areas were otherwise devoid of any other demonstrable microscopic lesions. No similar astrocytic reaction of any severity was observed in the same areas in a number of other brain diseases or controls, except when other kinds of lesions were present in the same section, with reactive astrocytes being present within the primary or defining lesion or immediately close by. The marked astrogliosis in von Economo's and postencephalitic Parkinson's diseases in areas "distant" from the primary lesions seeming to indicate extensive pathological involvement, added to the strong qualitative and quantitative similarity of this reaction to that observed in concurrently studied cases of encephalitides caused by the human immunodeficiency virus, lend further factual support to the hypothesis of a viral etiology, albeit unspecified, in both von Economo's and postencephalitic Parkinson's diseases.

DNA binding protein profiles in Alzheimer's disease.

Eleven frozen autopsy specimens from cerebral cortex were tested for DNA-binding protein profiles. Six were Alzheimer's disease (AD) brains, 1 was Parkinson's/senile dementia of the Alzheimer's type and 4 were age-matched control brains. Proteins were extracted in a guanidine thiocyanate-containing solvent and freed of all nucleic acids by density gradient sedimentation. The proteins were separated by sodium dodecyl sulfate gel electrophoresis and transferred to nitrocellulose by electroblotting under conditions which favor renaturation of proteins containing only one type of polypeptide. The nitrocellulose was treated with partially denatured radiolabeled DNA, washed and subjected to autoradiography. An Mr = 43 000 (43 K) DNA-binding protein was detected in 5 of the 6 AD brains and was found to be absent or at least greatly reduced in any of the other 6 brains. No other DNA-binding proteins were found which could be associated with AD brains. The nature of the 43 K protein has yet to be determined.

Antineurofilament antibodies in postencephalitic and idiopathic Parkinson's disease.

Autoantibodies to neurofilaments were found by the immunofluorescence technique in serum of patients with postencephalitic (von Economo's) and idiopathic Parkinson's disease in the same proportion as in age-matched neurological and non-neurological controls. In addition, similar neurofibrillary staining was detected in age groups of 29 years and younger, but rarely in the first year of life. Persons over 70, with or without disease, showed a prevalence of antibodies significantly higher than in persons under 70. Serum from 1 case of Alzheimer's disease out of 4 tested, was positive for neurofilament antibodies; serum from the only case of Creutzfeldt-Jakob disease tested was negative. A total of 298 serum specimens, each from a different person, was tested. The use of cryostat-frozen longitudinal sections of normal rat spinal cord as a substrate has been confirmed to be an effective, reproducible and simple procedure for the detection of antineurofilament antibodies in human sera by indirect immunofluorescence.

The viral hypothesis in parkinsonism.

The most crucial unanswered question in Parkinson's disease is its fundamental cause. Since Carlsson's original suggestion that dopamine may be a transmitter in the central nervous system involved in the control of motor function and that it may be involved in the Parkinsonian syndrome (Carlsson, 1959), and the now-classic paper by Ehringer and Hornykiewicz (1960) which definitively showed the significant reduction of dopamine concentration in the neostriatum of cases of idiopathic Parkinson and postencephalitic parkinsonism, the vast amount of work on the subject has focused on the biochemical and pharmacologic correlates of this dopaminergic system failure involving particularly the nigrostriatal pathways. The concept of a specific neurotransmitter deficiency associated with a specific neurological syndrome potentially amenable to replacement therapy, has appropriately generated a considerable degree of clinical and research interest for over 20 years, but, with few exceptions, there has been hardly any focused or concerted research effort on looking at direct causal factors or primary initiating events in this disease process. As in Alzheimer's disease, another of the degenerative diseases of the brain of unknown origin with a specific biochemical substrate, any etiologic hypothesis for Parkinson's disease--whether a virus, an age-related immune system dysfunction, a genetic factor, a "trophic" substance, or a toxin--would have to explain the selective involvement of specific transmitter-defined neuronal pathways, the non-specificity of the brain lesions that define the disease, and the clinical involvement of a sizeable segment of the aging population. Of the several plausible hypotheses mentioned earlier, which are not necessarily mutually exclusive, we would like to critically consider the possibility of a viral cause.