An outbreak of poliomyelitis caused by poliovirus type I in captive black and white colobus monkeys (Colobus abyssinicus kikuyuensis) in Kenya

In the latter part of 1982, three black and white colobus monkeys, Colobus abyssinicus kikuyuensis, from a small breeding group maintained at the Institute of Primate Research in Kenya, became paralysed within one month. Two of these cases were fatal and the third animal survived. The clinical and pathological findings suggested a poliomyelitis-like disease. This was confirmed by the isolation of wild strains of poliomyelitis virus type I from faeces, spleen, kidney, lung and central nervous system from affected animals.

Mouse strain-specific central nervous system lesions associated with lactate dehydrogenase-elevating virus infection

The histopathologic and virologic features of several mouse strains inoculated with the C strain of lactate dehydrogenase-elevating virus are described. Young C58 and AKR mice were found to develop histologic poliomyelitis when injected with cyclophosphamide prior to peripheral inoculation of lactate dehydrogenase-elevating virus. None of the C58 mice developed serious hindlimb paralysis, but some of the AKR mice did. Chronic poliomyelitis persisted for many weeks after infection in some C58 mice, but a spongioform poliomyopathy of the anterior horn was found in others. In contrast, inoculation of young C57BR/cd mice with lactate dehydrogenase-elevating virus produced inflammatory lesions restricted to central nervous system white matter that could be detected many weeks after infection. The most frequent findings were moderate leptomeningitis and myelitis localized to the white matter, however, radiculitis was also occasionally observed. Severe necrosis of spinal cord white matter was seen rarely. Development of lesions in C57BR/cd mice did not require immunosuppression prior to peripheral inoculation with virus and was not age related, sex linked, or exclusively controlled by the H-2 histocompatibility locus. Lactate dehydrogenase-elevating virus-infected C57L, C57BL/6, and RF mice did not develop poliomyelitis; however, C57L and C57BL/6 mice displayed a low incidence of mild encephalomyelitis. Poliomyelitis-susceptible C58 mice had the highest levels of viral infectivity in plasma and central nervous system tissues. White matter disease-susceptible C57BR/cd mice had viral titers in plasma and central nervous system tissues comparable to poliomyelitis-resistant C57L, C57BL/6, and RF mice. These studies demonstrate that different strains of mice have differing susceptibilities to the development of central nervous system inflammatory diseases.

A clinical study of post polio infantile paralysis

This study reports on 3,000 cases of poliomyelitis seen at the Rehabilitation and Artificial Limb Centre at Lucknow between January 1976 and December 1980. Factors such as age and sex incidence, extremity involvement, incidence of deformities at hip, knee and ankle, lower limb discrepancy, treatment and orthoses prescribed are discussed.

The effects of long-term immobilization on the histomorphology of human cortical bone

The cortical bone histomorphometrics, total visible osteon density, and mean osteonal cross-sectional area were determined for the major long bones and sixth ribs of two individuals with neurological deficit. One was a multiple sclerosis patient who had been in a wheelchair for 15 years. The other was a quadriplegic as a result of poliomyelitis. Statistically significant differences in osteon densities occurred only in the case of the quadriplegic. Nevertheless, in that subject, the total visible osteon densities for bones of the right arm were not statistically different from these of their age-matched (control) radii. Medical history records revealed that there had been partial use of this limb. These results support the belief that mechanical stress is an important factor in the maintenance of normal cortical bone remodeling. In addition, since there were subnormal osteon densities and normal mean osteonal cross-sectional areas, immobilization appears to be characterized by reduced activation frequency with a normal amount of bone turnover per BMU.

Mechanical determinants of bone modeling

In angulated long bone malunions in children, bone architectural changes arise which act consistently in kind, location, and direction, while the associated bone strain-stress patterns become definable as qualitative differences from the norm. Comparison of such information reveals that bone architectural adaptations correlate one-to-one with dynamic flexural strain orientation and magnitude but not with any single principal stress. The above plus other facts suggest six axioms which can explain many of the observed architectural adaptations of lamellar bone in response to specific mechanical bone-loading phenomena in normal as well as pathologic states. In essence those axioms state: In growing mammals and under repetitive, uniformly oriented, nontrivial, dynamic flexural strains, all lamellar bone surfaces drift in the concave-tending direction. As a result of these strains, a bone would adopt a size and configuration that minimize its flexural deformation during normal activities. The axioms provide reasonable explanations for inwaisting of vertebral bodies and long bone metaphyses, correction of malunions, increasing outside diameter and cortical thickness during growth, circular, elliptical, and triangular cross-sections, natural curvatures of whole bones, many architectural changes due to neuromotor abnormalities arising in early life, and the more rapid modeling seen in very young children or after recent fractures.

Hematogenous origin of the inflammatory response in acute poliomyelitis

To determine the origin of the inflammatory response, and in particular the microglial rod cell response, in acute viral encephalitis, 4-week-old Swiss mice were injected with tritiated thymidine to label actively dividing cells prior to infection with the Lansing type 2 strain of poliovirus. As expected, the majority of polymorphonuclear and mononuclear leukocytes within the central nervous system perivascular infiltrates were shown to be hematogenous in origin. As early as 24 hours after infection, isotope-labeled cells having light histological and ultrastructural features consistent with microglia and microglial rod cells were identified within brain parenchyma and were shown to participate in neuronophagia and formation of glial nodules. Supraependymal and suprachoroidal cells were also shown to contain the label. However, neither endothelial cells nor pericytes contained label as determined by electron microscopy. These studies support a hematogenous origin for all cellular elements of the classic inflammatory response in viral infections of brain.

Autonomic neurons of the sacral spinal cord in amyotrophic lateral sclerosis, anterior poliomyelitis and "neuronal intranuclear hyaline inclusion disease": distribution of sacral autonomic neurons

Further evidence is presented that the Onuf's nucleus (or "colonne en torsade" of Laruelle) and the intermediolateral nucleus of the sacral cord share common selective vulnerability with the thoracolumbar intermediolateral nucleus in ALS, anterior poliomyelitis and "neuronal intranuclear hyaline inclusion disease". Sparing of the sacral nuclei in the motor neuron diseases and neuronal loss of the nuclei in the multisystem atrophy are correlated well with normal and disturbed vesicorectal function. The clinicopathological evidence strongly supports the view that the Onuf's nucleus represents autonomic neurons much as the intermediolateral nucleus.

Detection of Theiler's virus RNA in mouse central nervous system by in situ hybridization

The location and distribution of viral RNA were examined in the central nervous system tissues of weanling mice acutely infected with the GDVII strain of Theiler's murine encephalomyelitis virus. Viral RNA was detected by autoradiography following in situ hybridization of a 3H-labeled DNA synthesized in vitro complementary to purified viral RNA. Viral RNA was detected in pyramidal neurons of the hippocampus, cerebral cortex, brainstem nuclei, thalamus, basal ganglia, and spinal cord. Autoradiographic grains could be detected in the axonal and dendritic processes of many infected neurons. No viral RNA was detected in any cell of the cerebellum or white matter. In addition to demonstrating the location of viral RNA in infected central nervous system tissues, and hence the sites of viral replication during this acute polioencephalomyelitis, they indicate that necrosis of hippocampal neurons is due to lytic infection, rather than to hypoxia.

Spongiform polioencephalomyelopathy caused by a murine retrovirus. II. Ultrastructural localization of virus replication and spongiform changes in the central nervous system

The development of murine retrovirus induced spongiform polioencephalomyelopathy was studied sequentially by electron microscopy. During the initial 30 days, viral infection of the central nervous system, as evidenced by viral budding from membranes, was limited to the endothelial cells and pericytes. Viral particles were observed in the lumen of blood vessels, extracellular spaces and astrocytic endfeet surrounding blood vessels, but no morphological evidence of productive infection was found in astrocytes or neurons during early development of vacuolation. The earliest lesions in the neuropil consisted of swelling of astroglia followed by vacuolation, initially in axons and dendrites and later in neuronal and astrocytic soma, where vacuoles appeared to arise from dilated cisternae of the Golgi apparatus. Vacuoles contained only amorphous debris and fragments of membranes. Virions budding aberrantly into vacuoles were seen only in mice surviving beyond 35 days. Numerous reactive astrocytes were observed, but inflammatory cells were absent. The ultrastructural changes were remarkably similar to those described in scrapie, Kuru, and Creutzfeldt-Jakob disease.

Non-suppurative encephalomyelitis in cats suggestive of a viral origin

In 10 of 16 domestic cats with spontaneous non-suppurative encephalomyelitis, lesions were multifocal but relatively few and were considered nonspecific as to cause, although viral agents could not be excluded. Six cats had polioencephalomyelitis or polioencephalitis suggestive of viral infection. The clinical and morphological features are compared with those of previous reports of feline encephalitis possibly of viral origin. Some previously reported epidemiological and serological surveys suggest a possible role for arboviruses.

Muscle lipids in Duchenne muscular dystrophy

The lipids of muscle and adipose tissue from normal males and of muscle from males with Duchenne muscular dystrophy were investigated. Triglyceride, the major neutral lipid, showed similar fatty acid compositions in all tissues examined. When the phospholipids of dystrophic muscle and of normal adipose tissue were compared with those of normal muscle, it was found that there was an increase in the proportion of sphingomyelin in dystrophic muscle, while adipose tissue had higher proportions of sphingomyelin and lysophosphatidylcholine but lower choline phosphoglyceride. In dystrophic muscle only small alterations from normal were observed in the fatty acid compositions of the individual phospholipids, whereas the phospholipids of adipose tissue had quite distinctive fatty acid compositions. An atrophic muscle sample resulting from poliomyelitis consisted almost entirely of connective tissue and fat and had a phospholipid composition similar to that of adipose tissue. From a comparison of the results for all the types of tissue studied, it is evident that the increase in sphingomyelin in dystrophic muscle biopsies and the changes in the fatty acid compositions of individual phospholipids may be accounted for by the increased amounts of fat and connective tissue which are present in dystrophic muscle samples. In a case each of polymyositis, limb girdle muscular dystrophy and an autosomal recessive form of muscular dystrophy, the results obtained for the phospholipid composition of the muscle sample were also normal or consistent with some contamination from fat and connective tissue.

[Electron microscopic study on muscle spindles in poliomyelitis (author's transl)]

The ultrastructures of the fifteen muscle spindles in poliomyelitis were studied especially concerning the structural alterations of intrafusal muscle fibers, sensory and motor nerve endings, though light microscopically previous workers have yielded no significant findings. Simultaneously performed light microscopic study of the same specimens revealed degenerative changes of the capsules in four muscle spindles and less significant changes in the remaining eleven muscle spindles. Ultrastructural findings of intrafusal muscle fibers consist or small vacuoles with irregular loss of myofilaments. Electron density of mitochondria in sensory nerve endings have increased and its cristae have disappeared. Plasma membranes of sensory nerve endings and intrafusal fibers are discontinuous. Mitochondria in motor nerve endings showed same findings, and basal lamina and junctional folds are also discontinuous or partially obscure. These findings seem to be neuropathic alterations of muscle spindles in poliomyelitis.

Poliomyelitis: immunoglobulin-containing cells in the central nervous system in acute and convalescent phases of the human disease

The immunoperoxidase method has been used to demonstrate the presence of immunoglobulin-containing cells in the central nervous system in acute and convalescent phases of poliomyelitis. These cells were found in considerable numbers in the areas of damage during the acute phase, and persisted at the same sites, though in smaller numbers, during the convalescent phase for at least 8 months. Most of the positively stained cells were plasma cells. IgA was the commonest heavy chain type demonstrated, with lesser amounts also of IgG and, during the acute phase, IgM. In the acute phase more lambda than kappa light chain was demonstrated but in the convalescent phase this ratio was reversed. More light chain than heavy chain was demonstrable during the acute phase. The significance of these results is briefly discussed.

Motor neuron disease following poliomyelitis. Bioptic study of five cases

5 cases of late motor neuron degeneration following poliomyelitis are presented. CPK, CSF, EMG and spine radiology were studied. In all cases, muscle biopsy evidenced neurogenic alterations both in previously affected limbs and in newly affected ones. Mitochondrial abnormalities were found in 1 case. The findings are discussed in the light of the literature with particular regard to the pathogenesis of the disease. The case with abnormal mitochondria is stressed for the possible relationship of this pathology with systemic degenerative diseases.

Mitochondrial abnormalities of late motor neuron degeneration following poliomyelitis and other neurogenic muscular atrophies

A case of late motor neuron degeneration following poliomyelitis with abnormal mitochondria in muscle fibers is presented with two additional cases of systemic neurogenic muscular atrophy (Charcot-Marie-Tooth disease). Muscle biopsy revealed a neurogenic pattern of variable severity in all cases. Subsarcolemmal zones of hyperactivity and hyperpositive intermyofibrillar collections of granular material present in a variable proportion of type I fibers were demonstrated by oxidative enzymes. Ultrastructurally they corresponded to abnormal mitochondria, with paracrystalline inclusions in one case. The finding is discussed in the light of the previous literature on mitochondrial myopathies. Mitochondrial alterations are not specific and their significance in neurogenic conditions is debated.

Roentgenmorphological muscle changes in anterior horn cell lesions

The author examined muscles in the extremities of 42 poliomyelitis patients using a special roentgenological technique. This method made it possible to objectively determine the size of the muscles in the soft tissues of the extremities. The volume and distribution of the increased amounts of fatty tissue in the muscle and the volume of normal muscle tissue led to draw conclusions regarding the histological state of the muscle. Roentgenmorphological changes are closely linked to muscle dysfunction. Roentgenological examination of the soft tissue provides a useful supplement to a muscle biopsy and to electromyographic examinations and is of value for the rehabilitation of the patients.

"Glial bundles" in the spinal cord late after paralytic anterior poliomyelitis

"Glial bundles" in the proximal portion of the anterior spinal roots, identical to those in Werdnig-Hoffmann disease, were observed in 3 patients many years after attacks of acute paralytic anterior poliomyelitis. These structures should therefore be considered a nonspecific astrocytic reaction secondary to the destruction of motor neurons and their axons rather than a malformation specific for Werdnig-Hoffman disease.

Sparing of the Onufrowicz nucleus in sacral anterior horn lesions

Sacral anterior horns were examined with special reference to the Onufrowicz nucleus in 3 patients with Werdnig-Hoffman disease, 2 with healed anterior poliomyelitis, and 1 who had undergone amputation of both legs above the knee. None of these patients showed symptoms of either urethral or anal sphincter disturbances. The Onufrowicz nucleus of the second sacral anterior horn appeared normal in all the patients examined, though the lateral portion of that horn and the medial nuclear group of the third sacral segment were frequently involved. These findings support the view that the Onufrowicz nucleus may be innervating the external sphincter muscle of the urethra and the anus.