Subacute sclerosing panencephalitis: a review

Measles virus-specific plasma cells are prominent in subacute sclerosing panencephalitis CSF

OBJECTIVE

To demonstrate the specificity of expanded CD138(+) plasma cell clones recovered from the CSF of a patient with subacute sclerosing panencephalitis (SSPE) for measles virus (MV).

METHODS

IgG variable region sequences of single-antibody-secreting CD138(+) cells sorted from SSPE CSF were amplified by single-cell PCR and analyzed. Human IgG1 recombinant antibodies (rAbs) were produced from four expanded CD138(+) clones and assayed for immunoreactivity against MV proteins.

RESULTS

Clonal expansion was a prominent feature of the SSPE plasma cell repertoire, and each of the four rAbs assayed was specific for either the MV fusion or the MV nucleocapsid protein.

CONCLUSIONS

Expanded plasma cell clones in the CSF of patients with subacute sclerosing panencephalitis produce disease-relevant antibodies. Recombinant antibodies derived from CSF B cells could provide a tool to identify target antigens in idiopathic inflammatory disorders.

Environmental risk factors for subacute sclerosing panencephalitis (SSPE)

In Israel, SSPE has been shown to be much more frequent among Sephardic Jews and Arabs than among Ashkenazic Jews. In the present study, we tried to explore environmental factors that may be of etiological importance and explain these differences in prevalence. The study is a case-control one, which includes 95 patients and 2 groups of controls, with 95 people in each. The general population controls were group-matched to the case group by sex, age, and ethnic origin. The family controls consisted of the sibling closest in age to each patient. A statistically significant positive correlation was found between risk of SSPE and early measles infection, large family, overcrowding in the home, older age of the mother, higher birth order, fewer years of schooling of the parents, fewer cultural activities, and rural place of birth. All these factors are interpreted as contributing to a higher risk of early measles infections, which thus may well be the main risk factor for SSPE.

Measles virus antigen in macrophage/microglial cells and astrocytes of subacute sclerosing panencephalitis

In two patients with subacute sclerosing panencephalitis (SSPE) of 10 and 25 months duration we demonstrated by immunohistochemistry the presence of measles-virus nucleocapsid antigen (MVNA) in CD68+ cells and astrocytes of brain tissues. In both cases, CD68+ hematogenous monocyte/ macrophages and perivascular microglial cells (Mphi) were found infiltrating the brain parenchyma, and often partially or completely invested by perivascular reactive astrocytes expressing glial fibrillary acidic protein (GFAP). Mphi with cytoplasmic MVNA were often seen in the Virchow-Robin spaces and in close association with perivascular astrocytes, which often also contained MVNA+ intracytoplasmic inclusions. Reactive astrocytosis was more severe in the patient with long-standing illness, and a correspondingly elevated number of strongly GFAP+ MVNA+ or MVNA- perivascular binucleated astrocytes was observed. An uptake of MVNA+ cell debris by reactive astrocytes was evident in areas of white matter displaying extensive demyelination and necrosis. Taken together, these observations seem to indicate that the brain infiltration by Mphi carrying measles virus could represent one pathway of virus entry and dissemination in the central nervous system. Virus transfer to perivascular astrocytes via cell-to-cell contacts with infected macrophages is also suggested.

Central nervous system virion detection in acute measles: histopathological, ultrastructural and pathogenetic aspects

Histopathological and ultrastructural studies of 23 patients who died with clinical diagnosis of measles were carried out. In 12 cases viral nucleocapsids were searched by electron microscopy and detected in 100% of the cases in the lungs and in 50% of the cases in the central nervous system. They were mostly intranuclear. Histopathological changes associated to neurological alterations and the detection of virion are discussed in relation to acute and delayed clinical manifestations.

Aspects of canine distemper virus and measles virus encephalomyelitis

Canine distemper (CD) is a frequently fatal, systemic morbillivirus infection in the dog and other carnivores: encephalomyelitis is the common cause of death. Susceptibility to canine distemper virus (CDV) is now recognized in a wide range of non-domestic animals, most recently in captive lions, tigers and leopards. Furthermore, closely related viruses have produced CD-like diseases in marine mammals. CDV induces an inclusion-body encephalomyelitis in the dog and demyelination is often a conspicuous feature. Myelin injury is associated with the presence of virus but the mechanism of demyelination remains incompletely understood. Oligodendrocyte infection may be defective, as has been shown in vitro. CDV and measles virus (MV) produce similar systemic disorders in their respective hosts but differ markedly in the frequency of central nervous system (CNS) involvement, and in the pathogenesis of the more common neurological sequelae. Both CDV and MV have been considered as multiple sclerosis agents, and the association of CDV with other human disease has been suggested.

Measles virus-specific human T cell clones: studies of alloreactivity and antigenic cross-reactivity

Cross-reactivity between altered self and foreign major histocompatibility complex (MHC) may be of etiologic importance in autoimmune disease. We have studied 29 measles virus-specific cloned and uncloned T cell lines from a patient with multiple sclerosis (MS) and from a normal subject. Two of the T cell clones derived from the normal subject reacted with foreign MHC determinants. No cross-reactivity between measles virus and either myelin basic protein (BP) or galactocerebroside (GC) was detected. T cell clones which are specific for nominal antigen and which also recognize alloantigen were detected with much smaller frequency than that reported in murine systems. Our data do not support a role for alloreactive measles-specific T cells, nor for cross-reactivity between measles virus and either BP or GC, in the pathogenesis of MS.

Immunohistochemical and electron microscopic techniques in the diagnosis of viral encephalitides

Electron microscopy and in particular, immunohistochemical examination techniques have substantially improved the chances to attain an etiologic diagnosis in viral encephalitis. The application of these techniques is needed first of all in the examination of cerebral biopsy specimens, but they can contribute to the clearing of the etiology at post mortem study of the brain, too. This review outlines the basic techniques and their application fields. In immunohistochemistry beside the demonstration of specific viral antigens the analysis of the humoral and cellular immune reactions and the identification of the cell types involved by cell specific markers is also important. The second part of the review gives a synopsis of the results of electron microscopic and immunohistochemical studies in the most important acute, subacute and chronic encephalitides occurring in Europe.

Natural history of restricted synthesis and expression of measles virus genes in subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a slow infection caused by measles virus in which several years separate recovery from typical acute measles and the development of a slowly progressive neurological disease. We have investigated replication of measles virus in brain tissue obtained after the onset of neurological disease and in the terminal phase. With a hybridization tomographic technique that combines in situ hybridization with macroradioautographic screening of large areas of tissue, we analyzed the spatial and temporal distribution of virus genes in vivo, using region- and strand-specific probes for the nucleocapsid and matrix genes. We show that early in the course of SSPE there is a global repression in the synthesis and expression of the genome. In the final stage of SSPE most infected cells still have depressed levels of plus- and minus-strand viral RNA and contain nucleocapsid protein but lack matrix protein. These findings provide further evidence for a unified view of slow infections of the nervous system, where the general constraints on virus gene expression provide an explanation for persistence of virus in the face of the host's immune response, and the slow evolution of pathological change. In the final phases of SSPE the more specific block in virus replication accounts for the cell-associated state of the virus and the difficulty in virus isolation.

Cloning of DNA corresponding to four different measles virus genomic regions

Hybrid plasmids containing sequences corresponding to four different regions of the measles virus genome inserted in pBR322 were obtained by use of polyadenylated 50 S viral RNA as template for reverse transcription. One class of plasmids contains inserts corresponding to the 3' terminal region of the virus genome. The sequence of one of these inserts (605 nucleotides) partially overlaps with the cloned cDNA sequence corresponding to a part of the nucleocapsid protein (N) mRNA (M. Gorecki and S. Rozenblatt (1980). Proc. Natl. Acad. Sci. USA 77, 3686-3690). This insert region shows only one long open reading frame defining the N-terminal part of the nucleocapsid protein. The nucleocapsid protein mRNA starts at about 60 nucleotides from the genome end as revealed by nuclease S1 mapping. Three other classes of plasmid clones contain inserts derived from unidentified regions of the viral genome; they hybridize with viral mRNA species less abundant than those from which cDNA clones have been isolated so far (S. Rozenblatt, C. Gesang, V. Lavie, and F. S. Neumann (1982) J. Virol. 42, 790-797.

Chronic encephalomyelitis with specific increase in intrathecal mumps antibodies

Symptoms of severe encephalomyelitis developed in a 31-year-old man in 1967. He had a high serum antibody titre to mumps virus associated with a polymorphic cell reaction and an increased protein concentration in cerebrospinal fluid (CSF). He recovered considerably within a year and was able to resume work. In 1975 his condition deteriorated again; it improved during the following few years, but a further deterioration then occurred. In March, 1981, the complement-fixing antibody titre to mumps virus was 1/32 in the serum and 1/4 in the CSF. In November, 1981, the CSF IgG index was increased and the altered serum/CSF antibody ratio persisted. The specificity of the altered antibody ratio was confirmed by the single radial haemolysis test and an immunoassay specific for mumps virus. Antibodies against the mumps virus envelope glycoprotein, M-protein, and nucleoprotein could be demonstrated by immunoprecipitation and the antibody patterns in serum and CSF were similar. Antibodies against other microorganisms were not detected in the patient's CSF, and mumps antibodies were not found in the CSF specimens of 57 control patients. This case may be an example of a new disease-chronic mumps virus infection in the central nervous system.

A comparative analysis of measles virus RNA by oligonucleotide fingerprinting

Isolates from two cases of acute measles, one case of acute measles encephalitis and three patients with subacute sclerosing panencephalitis were compared. This comparison was based upon the electrophoretic analysis of T1 oligonucleotides from single-stranded, full-length RNA isolated from cytoplasmic nucleocapsids. Although all viruses have oligonucleotides in common, each isolate generated a unique pattern of oligonucleotides. However, no group of oligonucleotides was observed which would allow a differentiation between viruses isolated from acute infections and those isolated from CNS diseases; indicating that probably all measles viruses differ in their nucleotide sequence, regardless of origin.

Distribution of measles antigen and immunoglobulin-containing cells in the CNS in subacute sclerosing panencephalitis (SSPE) and atypical measles encephalitis

The immunoperoxidase technique has been used to study the distribution of measles virus antigen and immunoglobulin (Ig)-containing cells within the CNS, in 5 cases of subacute sclerosing panencephalitis (SSPE) and 1 case of atypical measles encephalitis. Measles virus antigen was demonstrated within the brain in all cases, and in the spinal cord in 1 case of SSPE. Ig-containing cells were also demonstrated in all cases, the proportions of the different light and heavy chain types varying somewhat from case to case. In SSPE IgG constituted the major and IgA the principal minor heavy chain demonstrated. In all cases of SSPE there was significant excess of light-chain-containing over heavy-chain-containing cells. In the case of atypical measles encephalitis there was a paucity of Ig-containing cells and a relatively high proportion (39%) of these contained IgM. The case of atypical measles encephalitis differed from those of SSPE also in the presence of multinucleate giant cells, some of which contained measles virus antigen.

Antibody response to structural proteins of measles virus in patients with natural measles and subacute sclerosing panencephalitis

By immunoprecipitation and SDS-polyacrylamide gel electrophoresis, antibody responses to the structural proteins of measles virus were examined on patients with various forms of natural measles, atypical measles, and subacute sclerosing panencephalitis (SSPE). The serum of atypical measles most strongly reacted with four structural proteins, i.e., hemagglutinin (H), nucleocapsid (NC), fusion (F), and matrix (M) proteins. In natural measles, antibodies to the four structural proteins were detected at such an early convalescent stage as one month after the onset of disease. In late convalescent serums taken 9 years after natural measles, however, only low level antibody to M protein was present, whereas antibodies to H, NC and F proteins persisted. The serums and cerebrospinal fluid of SSPE patients showed patterns similar with those of the late convalescent serums. In Vero cells infected with cell-associated SSPE viruses (Niigata-1, ZH, and SI strains), M protein was not clearly demonstrated with serum of either atypical measles or SSPE patients, whereas H protein was demonstrated.

Analysis of structural proteins of measles, canine distemper, and rinderpest viruses

Serological relationships among measles virus (MV), canine distemper virus (CDV), and rinderpest virus (RV), which constitute morbillivirus subgroup of paramyxoviridae, were investigated by immunoprecipitation and SDS-polyacrylamide gel electrophoresis for their major structural proteins, i.e., hemagglutinin (H), nucleocapsid (NC), fusion (F), and matrix (M) proteins. The molecular weights of the four structural proteins of MV and CDV were confirmed to correspond to those previously reported by several investigators. Structural proteins of RV were analyzed for the first time in the present study and found to have molecular weights of 74,000, 62,000, 44,000, and 40,000 for H, HC, F, and M proteins, respectively. By labeling with glucosamine, the presence of carbohydrate moiety was found in H protein for all the three viruses and in F protein of CDV. The serums from the convalescent animals infected with respective virus disclosed one-way cross pattern depending on the combinations of virus and antiserums, but failed to show the reciprocal cross reactivity. On the other hand, hyperimmune serums to respective virus showed the reciprocal cross-reactivity with the four structural proteins indicating that each of the major structural proteins possesses the antigen common to all three morbilliviruses.

Cerebrospinal fluid IgG changes in subacute sclerosing panencephalitis in the various stages of the disease and during isoprinosine therapy

The cerebrospinal fluid (CSF) levels of IgG and the separation of the CSF and serum proteins by isoelectric focusing (IEF) were studied in 5 patients with subacute sclerosing panencephalitis (SSPE). Oligoclonal IgG fractions were found in the CSF of all the patients. The CSF IgG, IgG-Index and IgG SYN values were higher in the patients observed in the earlier than in those seen in the later stages of the disease. 1 of the 3 patients treated with isoprinosine presented a partial clinical remission accompanied by an increase in the parameters of intrathecal IgG synthesis.

A rapid immunoperoxidase assay for determination of IgG antibodies to measles virus

A new indirect peroxidase antibody to membrane antigen (IPAMA) technique for the detection of IgG specific antibodies against measles virus is described. The technique utilizes as antigen measles-infected Vero cells dried on glass slides and stored at --70 degrees C. Sera of 509 healthy medical students and laboratory workers and 24 sera of measles, encephalitis, and subacute sclerosing panencephalitis (SSPE) patients were checked by IPAMA and the results have been compared with the results obtained by the hemagglutination-inhibition (HI) test. There is good agreement between the results of both techniques as to the presence or absence of antibody in 48 out of the 50 tested. The advantages of the techniques are discussed.

Antibody-mediated destruction of virus-infected cells

This chapter describes the effect of antibody on virus-infected cells with special reference to the human system. The destruction by antibody of the infected cells through the mediation of complement is described in detail based in considerable part on the contributions of the authors. Activation of the alternative pathway by the various infected cells is of special interest. The interesting effect of the antibody-dependent cell-mediated cytotoxicity (ADCC) system involving viral antigens in cell killing is also presented. Multiple additional topics are also covered, such as the effect of antibody on the expression of viral proteins both on the surface of the cell and intracellularly. Serum antibody, produced in response to virus infections, is of major importance in preventing the spread of infection by virtue of neutralizing free virus in extracellular fluids. Virus neutralization by antibody is enhanced by complement. Antibody binding to the surface of virus-infected cells can affect virus production and release in the absence of an effector system. Immunoglobulin (IgG) antibody can mediate the destruction of virus-infected cells in conjunction with complement or cytotoxic lymphocytes. In addition, at a conceptual level there is evidence to suggest that antibody may enhance and confer specificity on basic nonspecific humoral and cell-mediated defense mechanisms.

Chronic canine distemper virus encephalitis in mature dogs

Five dogs 2 to 8 years old with old dog encephalitis were compared to five other dogs, 4 to 8 1/2 years old, with prolonged multifocal demyelinating distemper encephalitis. The dogs with old dog encephalitis had a diffuse panencephalitis involving most areas of the central nervous system with relative sparing of the cerebellum. The clinical signs were related to the cortical and subcortical lesions. The other dogs had severe focal necrotizing lesions mostly in the cerebellum and in the vicinity of the fourth ventricle; clinical signs were related to brainstem and spinal cord lesions. Viral isolation attempts were unsuccessful in the dogs with old dog encephalitis. In two dogs with multifocal encephalitis, canine distemper virus was isolated in tissue culture. The differences in lesions, clinical signs and observations in vitro indicate differences in pathogenesis between old dog encephalitis and multifocal demyelinating distemper encephalitis although both diseases may be caused by the same agent.

Further studies on subacute encephalitis and hydrocephalus in hamsters caused by measles virus from persistently infected cell cultures

Newborn hamsters were inoculated intracerebrally (IC) with disrupted measles carrier Lu 106 cells. No acute neurological disease developed, but limited, persistent neural infection was identified by immune fluorescence and by virus isolation. By ten days after inoculation, virus could be recovered only by cocultivation of explant cultures of central nervous system (CNS) tissue and Vero cells. Virus was still demonstrable in CNS by both techniques 50 days after inoculation, the latest sample collected. Animals inoculated as newborns developed a poor hemagglutination-inhibiting (HI) antibody response. In three-week-old hamsters inoculated IC no detectable replication of carrier virus occurred. The serum HI antibody response was more than 20 times higher than that in animals inoculated as newborns. Hydrocephalus developed in a fraction of animals inoculated at birth or at the age of three weeks. Both infectious and heat-inactivated disrupted virus carrier material, but not control material of Lu 106 cells, gave hydrocephalus. The precise mechanism leading to hydrocephalus is unclear. Carrier virus material may produce a meningeal irritation causing disturbances of the extraventricular flow or resorption of cerebrospinal fluid, leading to communicating hydrocephalus. Infectious carrier virus may replicate in and destroy ependymal cells, further contributing to hydrocephalus.

In vitro studies on Borna virus. II. Properties of the virus

Successful cultivation and titration of Borna disease virus in cell cultures enabled detailed studies of the virus properties. Borna virus is labile towards treatment with heat, pH 3.0 and lipid solvents. It is relatively stable at low temperatures and in frozen state. It is easily inactivated by ultraviolet light as e.g. vesicular stomatitis virus. After ultrafiltration studies, the size of the infectious virus unit is between 80 and 100 nm. Its buoyant density in cesium chloride is 1.165 g per ml. The one step multiplication curve shows that Borna virus has a replication cycle of about 2 days in BSC 1 cells. In growth experiments using antimetabilites it behaves like certain RNA containing viruses. As its multiplication is not inhibited by bromo- and iododeoxyuridine and actinomycin D, no DNA step seems to be involved in virus synthesis. Regarding these properties and the intracellular antigen distribution as shown by fluorescent antibodies, it is not possible to attribute Borna virus to any of the established virus groups.

Characterization of the cold-sensitive murine hepatitis virus mutants rescued from latently infected cells by cell fusion

Mouse hepatitis virus, a coronavirus, was rescued from latently infected mouse neuroblastoma cells by polyethylene glycol-induced fusion to permissive cells. The isolated viruses grew to equal or higher titers than parental JHM virus at 39° but were restricted in replication at 32° and hence were cold-sensitive mutants. Neither isolate synthesized RNA at the nonpermissive temperature (32°), and temperature shift experiments indicated that the restrictive cold-sensitive step in replication occurred during an early viral function. The isolates were unable to complement each other at 32°. Although coinfection between each mutant and parental JHM virus often resulted in decreased yields of both infecting viruses, interference could not be convincingly demonstrated. Both mutants were more thermostable than parental JHM virus and could be distinguished from each other and from parental JHM virus by their thermal inactivation kinetics. The isolates were obtained from single cell clones and therefore presumed to be homogeneous; however, thermal inactivation of one (S-3JHM) indicated the possible existence of a second population. Subclones of virus prepared from each isolate were also found to be thermally stable and to retain the cold sensitive defect. No indication of a second population of S-3JHM virus was detected.

Early events in canine distemper demyelinating encephalomyelitis

The early neuropathological development of demyelinating Canine Distemper Encephalomyelitis (CDE) was studied in SPF dogs. Neural tissues were examined up to 30 days post infection (PI). Three phases of activity were observed. The primary event (first observed 8 days PI) was a nonsuppurative encephalomyelitis associated with the initiation of central nervous system (CNS) infection by virus-laden lymphocytes. At 24 days PI noninflammatory demyelination occurred in well defined, subependymal foci. Cell fusion and syncytia formation accompanied this early demyelination. The third phase, found at day 30 PI in one dog showing signs of recovery, was a second wave of nonsuppurative inflammation. The initial encephalomyelitis was widely disseminated throughout the CNS but subsequent demyelination appeared to be initiated from within the ventricular system. Myelin was phagocytosed by endogeneous CNS macrophages often infected with Canine Distemper Virus (CDV). The possible importance of viral induced cell fusion as well as immune factors in the mechanism of demyelination are discussed.

In vitro studies on Borna virus. I. The use of cell cultures for the demonstration, titration and production of Borna virus

Borna virus produces non-lytic infections in a wide spectrum of primary cell cultures and cell lines. The sensitivity and virus yields vary with the different cell systems. Accurate virus titrations can be performed in the RK 13 cell line by counting immunoflourescent microfoci between the 5th and 10th day after infection. Since the virus is not released from the cells and does not spread via the culture medium, the use of a semisolid overlay in unnecessary in virus titrations. The cell line most productive for Borna virus is the CV 1 line. The conditions for optimum virus production include a prolonged cultivation period of at least two weeks with regular changes of medium, and an incubation temperature of 35 degrees C. Harvest of the virus requires thorough disruption of the infected cells, preferably by ultrasonication, since Borna virus seems to be closely associated with cellular structures.

Subacute encephalitis and hydrocephalus in hamsters caused by measles virus from persistently infected cell cultures

Newborn hamsters were inoculated intracerebrally with measles virus materials from Lu 106 and Vero carrier cell lines. Extracellular and cell-associated materials from cultures incubated at 37 degrees C and at 33 degrees C were used. The lower temperature allows accentuated virus replication. No animals contracted acute encephalitis, but 8 animals developed advanced neurological disease (unsteady gait, serial myoclonic jerks, hypoactivity) 79 to 212 days after injection. Seven out of these 8 animals belonged to a group of 50 animals, which had been inoculated with cell-associated material from cultures incubated at 33 degrees C. Viral antigen and nucleocapsids were found in neurons and glial cells from diseased animals, which showed degenerative changes and inflammation, particularly in the mesencephalon. Some of these animals also had hydrocephalus, which, however, also occurred in many apparently healthy animals. Also this pathological alteration occurred most frequently (5 out of 11 animals examined 9--10 months after inoculation) in hamsters receiving cell-associated material from carrier cutlures incubated at 33 degrees C. Possible mechanisms for the appearance of hydrocephalus are discussed.

Virus infection in demyelinating diseases

Several animal and human demyelinating diseases of the central nervous system (CNS) are associated with RNA or DNA viruses. These viruses infect CNS cells lytically or persistently. They mainly belong to the group of envelope viruses which derive their envelope partly from the host cell membrane. The process of virus release may result in the appearance of new antigens of virus-infected cells or the incorporation of cell membrane material into the viral envelope. These changes may lead to an immune response which selectively injures the CNS. These alterations of host cell membranes and host cell functions, together with the immune mechanism, are central to many of the hypotheses regarding virus-induced demyelination. The role of virus infection in progressive multifocal leukoencephalopathy, subacute sclerosing panencephalitis, visna and mouse hepatitis virus infections, is discussed in relation to the demyelinating process of these diseases.

Measles inclusion-body encephalitis in a child with treated acute lymphoblastic leukaemia

A child with acute lymphoblastic leukaemia, being treated in the UKALL II Trial, had while in remission an attack of measles and made a normal recovery. Four months later she developed an acute encephalopathy and died within two weeks. The brain showed mild inflammatory features and widespread inclusion bodies in neurones and glial cells. Immunofluorescence proved an infection with measles virus. Similar cases have been called SSPE; reasons are given for preferring the term "measles inclusion-body encephalitis".

Experimental measles encephalitis: a genetic analysis

The encephalitogenic potential of nine temperature-sensitive mutants of measles virus was determined in newborn golden Syrian hamsters. The parental virus produced acute encephalitis without any prior adaptation. Six of the mutants were attenuated, two were virulent, and one was associated with hydrocephalus with acute onset. The attenuated mutants, blocked before measles virus antigen and ribonucleic acid synthesis at 39 C, were all members of one complementation group. The virulent temperature-sensitive mutants, defective in hemolysin antigen synthesis at 39 C, were members of a second complementation group. The hydrocephalus-inducing mutant was genetically distinct from the other mutants. The mechanism of attenuation most probably does not involve a temperature-induced inhibition of virus replication, but rather appears to be related to the partial defectiveness of the mutants under permissive conditions.

Sporadic bovine meningo-encephalitis-isolation of a paramyxovirus

Isolation of a viral agent (107) directly from brain explants of a 15-month-old heifer with symptoms of a sporadic encephalomyelitis is described. The virus shares properties with the paramyxovirus family. It grows in a variety of cell cultures from different species, and induces nuclear and cytoplasmic inclusion bodies in infected cells. Nucleocapsids measuring 17 nm in diameter were found in the nucleus and cytoplasm of these cells when studied electron microscopically, thus indicating a close relationship of the agent to the measles-distemper-rinderpest group. No infectious virus was released from infected cells, although alignment of nucleocapsids was observed beneath the cell membrane, and no hemagglutinating activity could be detected with the methods employed. The 107 agent was compared serologically with parainfluenza viruses type 1, 2 and 3, simian virus 5, mumps and Newcastle disease virus (NDV), two bovine respiratory syncytial viruses and measles/subacute sclerosing panencephalitis, distemper and rinderpest viruses, always using 107 virus infected CV1 cells and antiserum of the different viruses in indirect FA tests. Positive FA reactions were observed only with two sera obtained from SSPE patients with high antibody titer to SSPE virus, and with one rabbit-anti-rinderpest serum. The titers of these sera to 107 virus, however, were significantly lower than those against homologous viruses. Five out of 9 sera from randomly selected healthy cattle showed antibody titers between 1:10 and 1:80 to 107 virus in FA tests. The significance of these results is discussed with respect to the epidemiology of SSPE in children and its possible implication with rinderpest in Europe.

Progressive rubella panencephalitis. Late onset after congenital rubella

In children with congenital rubella infection the deficits remain stable; neurologic deterioration after the first few years of life is not believed to occur. We have encountered three patients with a definite or presumptive diagnosis of congenital rubella, in whom a progressive neurologic illness developed that began in the second decade and was characterized by spasticity, ataxia, intellectual deterioration, and seizures. High antibody titers to rubella virus in serum and spinal fluid were present in two, and all had increased cerebrospinal-fluid protein and gamma globulin. Extensive attempts to recover a virus from brain and body fluids were unsuccessful. The brains of two patients showed a widespread, progressive, subacute panencephalitis mainly affecting white matter. These data suggest that rubella virus may be a cause of progressive panencephalitis.

On the effect of brain phospholipase A1 on specifically labelled glycerophospholipids in the course of subacute sclerosing panencephalitis

The effect of phospholipase A1 of human brain on 1,2-diacyl-sn-glycero-3-phosphorylcholine, -ethanolamine and -serine, specifically labelled with different fatty acids at either the 1 or 2 position, was determined in subacute sclerosing panencephalitis. An increase of approximately 40% in the specific activity of phospholipase A1 could be observed for all substrates investigated during the demyelinating disorder. On investigating the specific activity of the enzyme with various molecular species of phosphatidylcholine and -ethanolamine, labelled at the 1 position with different radioactive fatty acids, we found that the phospholipase A1 preferentially removed those fatty acids from the 1 position of phosphatidylcholines that have the fewest double bonds, while oleic and linoleic acid were released at almost similar rates from phosphatidylethanolamine.

SSPE-like inclusion body disorder in treated childhood leukemia

Clinico-pathological report on a boy with cytostatically treated leukemia, dying with cerebral symptoms after passing clinical measles 10 weeks before death. At autopsy, numerous nuclear inclusion bodies in glial and nerve cells were found. By electron microscopy, nuclear inclusions appeared as loosely arranged smooth tubules, corresponding to paramyxovirus nucleocapsids. Frequently, cytoplasmic changes appeared too, consisting of incomplete tubular structures and an abundant dense "fuzzy" material. No regular tubuli of the coated granular type were present, as in common measles virus infection, nor any mature viral structures or differentiation of the surface membrane. The lack of maturation in cytoplasm together with a predominance of nuclear changes suggested a slow type of measles virus infection, while the particular cytoplasmic changes suggested a defect in synthesis of granular nucleocapsids, possibly a basic factor for the slow type of the viral infection. Possible pathogenetic factors are discussed.