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Studies on arboviruses - Infection of undernourished mice by cocal virus
Exp. Pathol. 1988; 35: 189-195 VEB Gustav Fischer Verlag Jena
1) Departments of Pathology and Virology, School of Medicine and Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Brasil
Studies on arboviruses - Infection of undernourished mice by cocal virus l ) By F. DUARTE 2), D. DE PAOLA 2), K. MADI2) and M. C. CABRAU) With 5 figures Addressfor correspondence: Prof. Dr. FRANCISCO DUARTE, Av. Atlantica 700 ap. 501, Rio de Janeiro, Brasil. CEP. 22.010 Key words: arnazonic arboviruses; vesiculovirus; cocal virus; nervous system; panencephalitis; poliomyelitis; malnutrition; encephalitis; myelitis
Summary Normal and undernourished mice inoculated orally and intraperitoneally with cocal virus show panencephalitis and acute poliomyelitis, which is more accentuated in cases of malnutrition. Speculations are made regarding viral penetration and progression in the nervous system. Introduction The relationship between malnutrition and infection, particularly of a viral nature, is still unclear. Nevertheless, knowledge of this interrelation is fundamental to the understanding of the dynamics of viral infections with a violent or even fatal progression. Various experimental models implemented by researchers exhibit a classical approach to arboviral infections, using recently-born animals (DE PAOLA 1973). These models, however, give an incomplete idea of the reaction of the host to viral attack, as compared with a more recent proposal having been made using an older host, one modified by diet deficiency. This situation permits a longer course of infection, producing an extremely wide range of lesions (G6ES et al. 1981). In this study, it has been demonstrated that infection by the VSV (Piry) virus is synergic with the state of malnutrition, reproducing lesions uncommonly similar to those from poliomyelitis. Another modification found in this study involved intraperitoneal inoculation rather than intracerebral, which should have been favored by metameric structures, the medullary lesions. During recent years, an experimental model has been developed at the Departments of Pathology and Microbiology at UFRJ, using rats and mice submitted to preand postnatal proteincaloric malnutrition (CAMPOS and MADI 1975), which has already been utilized in association with viral infections (DE PAOLA et al. 1972; DE PAOLA 1973; G6ES et al. 1981). Experimental studies using vesiculoviruses have also been published by our group, analyzing the infection of recently-born mice and hamsters (BRUNO-LoBO et al. 1968). The cocal virus belongs to the vesiculovirus group and was discovered by JONKERS et al. (1964), leading to studies by other researchers such as WOODALL (1967), BUCKLEY (1964), DITCHFIELD and ALMEIDA (1964), DONALDSON (1970), and FEDERER et al. (1967), in addition to other investigations carried out by the JONKERS group (1964, 1965), and our group (NOZAWA 1976).
2) Professors at UFRJ, Researchers at National Research Center (CNPq). CNPq Procedures 30,1234179; 30,5266179; 30,5285176
Exp. Pathol. 35 (1988) 3
189
Materials and Methods
Eight lots of albino Swiss mice were used, provided by the UFRJ Institute of Microbiology. With ages ranging from 18 to 23 days (6 animals with the mother), four lots were given D-5 ration (6.7% protein) in order for them to become accustomed to it, in addition to being given commercial (normal) rations. At the age of 23 days, D-4 ration (3.2 % protein) was given to lots selected for undernourishment (D). Both these animals and those with normal diet (N) were given unlimited water, being placed in wire cages and either individually isolated (D) or grouped by twos (N) (table 1). Table 1. Rations Rations**
D-4
D-5
SCM*
SCM Manioc meal Maizena Com meal Brown sugar Soybean oil
350 g 150 g 400 g 500 g 400ml 120 ml
750 g 200 g 230 g 300 g 400ml 120 ml
Complete commercial ration for mice and rats with approximately 20 % protein.
protein
3.2%
6.7%
20%
* Sao Cristovao Mill ** Supplement with vitamin mixture twice weekly Following 12 days of deprivation, half of each group was inoculated with a sample of the cocal arbovirus as follows: oral injection was done with a syringe and a fine-point needle with rounded white gold tip, holding the mouse by the dorsal hair and introducing the needle into the esophagus. The virus dosage injected was 104 DLso, with a total volume of 0.2 ml. Inoculation was intraperitoneal (2 D lots and 2 N lots) and oral 0 D lot and I N lot), with 1 N lot and I D lot injected with the inoculation vehicle in the peritoneum and the esophageal needle. Identical controls were performed with the vehicle (1). The mice were anesthetized with ether, decapitated and immediately fixed with FAM (formol 10%, acetic acid 10%, methanol 80%) after removing the abdominothoracic viscera, jaw and anterior neck; they were then dehydrated in alcohol for 24 h, clarified in xylol and embedded in paraffin. Sections measuring 4 micrometers were obtained, mounted in synthetic resin and stained by the following methods: hematoxylin and eosin, cresylviolet (Nissl), and Holmes, for neurofibrils (16). Results
Observation of animals The mice showed onset of symptoms 3 days after inoculation, which intensified, after 5 days. They became apathetic, with bristling, dirty hair, being more exaggerated in group D, with a large number of dying animals being killed. Autopsy was performed on two-thirds of the total on the 4th and 5th days, with the remainder put to death 9 days following inoculation (at 44 days of age, 21 on protein-deficient diet). Histopathologic analysis Histologic lesions were mainly characterized by encephalomyelitis with selective topography at the level of the cerebral cortex, base nuclei, mesencephalon, and more rarely in the protuberance and cerebellar nuclei. Cortical and deep nuclei lesions were predominantly located in neuron cell bodies with chromatolysis, vacuolations, dysplasia and even neuronal necrosis, along with diffuse and focal microglial proliferation with neuronophagic figures, at times multiple and at times located 190
Exp. Pathol. 35 (1988) 3
paravascularly. On rare occasions there were necrotic areas with neuropile dissolution, usually located close to vessels (severe lesions + + +). In milder lesions (+), sparse neuronophagic foci with regressive neuronal changes were rarely found , and possibly in the cerebellum when it takes on a "glial shrub" appearance with Purkinje cell alterations. Less frequently found were small cortical vessels with endothelial tumefaction and mononuclear cuff with rare polymorphonuclear forms, as well as discrete mononuclear subarachnoid infiltrate. In only one case we did find subependymal
Fig. 1. Cerebral cortex showing diffuse and focal microglial proliferation with neuronophagic figures and discrete perivascular inflammatory cuff. H.E., X 100. glial lesions characterized by karyorrhexis. And only very rarely we found the scant presence of neutrophils , especially at the level of the necrotic lesions (fig. I, 2, 3 and 4). Medullar lesions were located at all levels and with variable predominance in the cervicothoracic and lumbar regions. These lesions were of varying intensity , being located with selective predominance at the level of the neurons of the anterior medullar tip (lesions from + to + + +). At this level , the neurons exhibited tumefaction, chromatolysis and necrosis with neuronophagic figures, and more rarely evident capillaries and endothelial tumefaction. Occasionally slight alterations with cellular retraction and discrete microglial proliferation could be seen at the level of the posterior columns. The posterior roots and dorsal ganglia showed no histological alterations. No lesions were found at the central canal level nor at that of the subarachnoid space. Other organs examined showed no histological changes related to viral aggression (table 2; fig. 5). Discussion
The correlative study of histological changes in undernourished animals suggests a clear predominance of the most serious and frequent lesions in undernourished animals inoculated through the peritoneum. There is also a correlation with findings of previous studies involving the piry virus (11). The role of malnutrition in the course of lesion development can therefore be affirmed. Low-intensity lesions in undernourished mice infected orally were less frequently observed, a finding we feel to be important in the analysis of lesion pathophysiology, making allowances for a probable epidemiologic correlation. Exp. Pathol. 35 (1988) 3
191
Table 2. Histopathologic lesions Mice aged 18 - 23 days inoculated with cocal virus Animals' number
Inoculation method
Dose
1223 N 1225 N 1227 N 1235 N 1241 D 1242 D 1247 D 1249 D 1250D 1251 D 1252 D 1253 D
peritoneal peritoneal peritoneal oral oral oral peritoneal peritoneal peritoneal peritoneal peritoneal peritoneal
0.25 0.25 0.25 0.25 0.25 0.25
rnl rnl rnl rnl rnl ml
0.25 0.25 0.25 0.25 0.25
rnl rnl ml rnl ml
Encephalitis
Myelitis WID lesions
+ ++ ++ ++ + + ++ ++ + +++ ++
+++ ++
7 4
++ + +++ ++
N = Normal diet; D = Undernourished; Fixative = FAM; Staining methods: H. E., Nissl, Holmes; No. animals examined: 48 (12 with and 12 without changes). 36 inoculated (l8N and 18D) with 12 not inoculated. 11 were unfit for evaluation. The finding of medullary lesions at the level of the anterior tip and more rarely in the posterior columns suggests the possibility of viral aggression stemming from initial peritoneal infection, by means of viremia and the penetration of nervous tissue by the posterior root region and dorsal ganglia where, according to BODIAN (1), HORSTMANN (12), BRIERLEY (2) an~ WAKSMAN (21), there is a break in the hematonervous and hematoganglial barrier. From this site of penetration, the virus would be capable of advancing through axons until reaching the anterior medullary tip with minimal lesions along its route through the dorsal and intermediolateral column (table 2). Conclusions
1. Experimental infection of mice by cocal virus shows definite central nervous system tropism provoking the histological condition of acute encephalomyelitis. 2. Lesions in undernourished animals are more frequent and of higher intensity than those given a normal diet. 3. In this study, perhaps for the first time ever, evidence was found of encephalomyelitis lesions from cocal virus by means of oral inoculation. 4. The histological picture, well-defined and constant, involving panencephalitis and acute anterior poliomyelitis during the effective period of oral and intraperitoneal inoculations and in addition to their increased seriousness in undernourished animals, allows for epidemiologic speculations in the case of Amazon arbovirus infections. 5. The experimental infection of mice by cocal virus provides an excellent model of encephalomyelitis for the future study of the pathophysiology, penetration and progress of the virus in the nervous system of experimental animals.
192
Exp. Pathol. 35 (1988) 3
Fig. 2. Base nucleus showing severe lesions with necrosis and neuron destruction. H.E., x 250.
Fig. 3. Cerebellar cortex showing Purkinje cell lesion and formation of "glial shrub". H.E., x450. Exp. Pathol. 35 (1988) 3
193
Fig. 4. Lateral ventricular ependyma showing karyorrhexis with subependymal glial lesions. H.E., X 250.
Fig. 5. Detail of anterior medullary tip with neuron lesions and neurophagia. Nissl's, 194
Exp. Pathol. 35 (1988) 3
X
450.
References 1. BOD!AN, D.: Polymyelitis. In: Pathology of the nervous system (ed. MINCKLER, J.), vol. 3, chapt. 170. McGrawHill, New York 1972. 2. BRIERLEY, J. B.: Acta Psychiatr. Scand. 1955; 30: 553. 3. BRUNO-LoBO, M., BRUNO-LoBO, G. G., PERALTAG, P. H., DE PAOLA, D.: Pathogenesis of vesicular stomatitis virus in the infant hamster and mouse. Ann. Microbiol. 1968; 15: 53-68. 4. BUCKLEY, S. M.: Applicability of the Hela (Gey) strain of human malignant epithelial cells to the propagation of arboviruses. Proc. Soc. Exp. BioI. Med. 1964; 116: 354-358. 5. CAMPOS, D. G., MAD!, K.: Estudos sobre desnutric;ao pre e p6s natal em ratos albinos. Parcial recuperac;ao ponderal e bioquimica. Rev. Bras. Pesq. Med. BioI. 1985; 8: 301-306. 6. DE PAOLA, D., MAD!, K., DUARTE, F., BRUNO-LoBO, G. G., BRUNO-LoBO, M.: Alterac;6es histoquimicas em ratos desnutridos inoculados com virus Oriboca. Ann. Microbiol. 1972; 19: 13-19. 7. - : Interac;ao virus-celula. Introduc;ao de modelos experimentais de infec<;ao arboviral. Gernasa Ed., Rio de Janeiro, RJ 1973. 8. DITCHFIELD, J., ALMEIDA, J. D.: The fine structure of cocal virus. Virology 1964; 24: 232-235. 9. DONALDSON, A. 1.: Am. J. Epidemiol. 1970; 92: 132. Cited in: Internat. cataloque of arbovirus (ed. BERGE, T. 0.), 2nd ed. Dept. of Health, Education and Welfare, Atlanta 1975. 10. FEDERER, K. F., BURROWS, R., BROOKSBY, J. B.: Vesicular stomatitis virus. The relationship between some strain Indiana serotypes. Res. Vet. Sci. 1967; 8: 103-117. II. GOES, P., DE PAOLA, D., DUARTE, F., MAD!, K., CABRAL, M. C.: Estudos sobre os arbovirus. XVIII. Acao experimental do virus Piry em camundongos desnutridos. Ann. Microbiol. 1981; 26: 7-18. 12. HORSTMANN, D. M.: Am. J. Med. 1949; 6: 535. 13. JONKERS, A. H. et al.: Am. J. Vet. Res. 1965; 26: 758-763. Cited in: Internat. cataloque of arbovirus (ed. BERGE, T. 0.), 2nd ed. Dept. of Health, Education and Welfare, Atlanta 1975. 14. - SPENCE, L., COAKWELL, C. A., THORNTON, J. J.: Laboratory studies with rodents and viruses native to Trinidad. I. Studies on the behavior of cocal virus. Am. J. Trop. Med. Hyg. 1964; 13: 613-619. 15. - SHOPE, R. E., AITKEN, T. H. G., SPENCE, L.: Cocal virus: a new agent in Trinidad related to vesicular stomatitis virus, type Indiana. Am. J. Vet. Res. 1964; 25: 236-242. 16. LUNA, G. L.: Manual of histologic staining methods of the Armed Forces Institute of Pathology. 3rd. ed. McGraw-Hill, New York 1968. 17. MAD!, K.: Contribic;ao 11 confecc;ao de urn modelo experimental de deficiencia proteica. Thesis, Univ. Rio de Janeiro 1970. 18. - JERVIS, H., ANDERSON, P. L., ZIMMERMANN, M. L.: A protein-deficient diet: effect on the liver, pancreas, stomach and small intestine of the rat. Arch. Pathol. 1970; 89: 38-52. 19. NOZAWA, C. M.: Relacionamento sorologico entre os differentes virus do grupo da estomatite vesicular. Master's thesis, Ed. Inst. Microbiol., UFJR 1976. 20. WOODALL, J. P.: Virus research in Amazonia. Atas do Simp6sio sobre a Biota Amazonica. 1967; 6: 31-63. 21. WAKSMAN, B. H.: J. Neuropathol. Exp. Neurol. 1961; 20: 35. (Received May 16, 1988; Accepted May 24, 1988)
Exp. Pathol. 35 (1988) 3
195
1) Departments of Pathology and Virology, School of Medicine and Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Brasil
Studies on arboviruses - Infection of undernourished mice by cocal virus l ) By F. DUARTE 2), D. DE PAOLA 2), K. MADI2) and M. C. CABRAU) With 5 figures Addressfor correspondence: Prof. Dr. FRANCISCO DUARTE, Av. Atlantica 700 ap. 501, Rio de Janeiro, Brasil. CEP. 22.010 Key words: arnazonic arboviruses; vesiculovirus; cocal virus; nervous system; panencephalitis; poliomyelitis; malnutrition; encephalitis; myelitis
Summary Normal and undernourished mice inoculated orally and intraperitoneally with cocal virus show panencephalitis and acute poliomyelitis, which is more accentuated in cases of malnutrition. Speculations are made regarding viral penetration and progression in the nervous system. Introduction The relationship between malnutrition and infection, particularly of a viral nature, is still unclear. Nevertheless, knowledge of this interrelation is fundamental to the understanding of the dynamics of viral infections with a violent or even fatal progression. Various experimental models implemented by researchers exhibit a classical approach to arboviral infections, using recently-born animals (DE PAOLA 1973). These models, however, give an incomplete idea of the reaction of the host to viral attack, as compared with a more recent proposal having been made using an older host, one modified by diet deficiency. This situation permits a longer course of infection, producing an extremely wide range of lesions (G6ES et al. 1981). In this study, it has been demonstrated that infection by the VSV (Piry) virus is synergic with the state of malnutrition, reproducing lesions uncommonly similar to those from poliomyelitis. Another modification found in this study involved intraperitoneal inoculation rather than intracerebral, which should have been favored by metameric structures, the medullary lesions. During recent years, an experimental model has been developed at the Departments of Pathology and Microbiology at UFRJ, using rats and mice submitted to preand postnatal proteincaloric malnutrition (CAMPOS and MADI 1975), which has already been utilized in association with viral infections (DE PAOLA et al. 1972; DE PAOLA 1973; G6ES et al. 1981). Experimental studies using vesiculoviruses have also been published by our group, analyzing the infection of recently-born mice and hamsters (BRUNO-LoBO et al. 1968). The cocal virus belongs to the vesiculovirus group and was discovered by JONKERS et al. (1964), leading to studies by other researchers such as WOODALL (1967), BUCKLEY (1964), DITCHFIELD and ALMEIDA (1964), DONALDSON (1970), and FEDERER et al. (1967), in addition to other investigations carried out by the JONKERS group (1964, 1965), and our group (NOZAWA 1976).
2) Professors at UFRJ, Researchers at National Research Center (CNPq). CNPq Procedures 30,1234179; 30,5266179; 30,5285176
Exp. Pathol. 35 (1988) 3
189
Materials and Methods
Eight lots of albino Swiss mice were used, provided by the UFRJ Institute of Microbiology. With ages ranging from 18 to 23 days (6 animals with the mother), four lots were given D-5 ration (6.7% protein) in order for them to become accustomed to it, in addition to being given commercial (normal) rations. At the age of 23 days, D-4 ration (3.2 % protein) was given to lots selected for undernourishment (D). Both these animals and those with normal diet (N) were given unlimited water, being placed in wire cages and either individually isolated (D) or grouped by twos (N) (table 1). Table 1. Rations Rations**
D-4
D-5
SCM*
SCM Manioc meal Maizena Com meal Brown sugar Soybean oil
350 g 150 g 400 g 500 g 400ml 120 ml
750 g 200 g 230 g 300 g 400ml 120 ml
Complete commercial ration for mice and rats with approximately 20 % protein.
protein
3.2%
6.7%
20%
* Sao Cristovao Mill ** Supplement with vitamin mixture twice weekly Following 12 days of deprivation, half of each group was inoculated with a sample of the cocal arbovirus as follows: oral injection was done with a syringe and a fine-point needle with rounded white gold tip, holding the mouse by the dorsal hair and introducing the needle into the esophagus. The virus dosage injected was 104 DLso, with a total volume of 0.2 ml. Inoculation was intraperitoneal (2 D lots and 2 N lots) and oral 0 D lot and I N lot), with 1 N lot and I D lot injected with the inoculation vehicle in the peritoneum and the esophageal needle. Identical controls were performed with the vehicle (1). The mice were anesthetized with ether, decapitated and immediately fixed with FAM (formol 10%, acetic acid 10%, methanol 80%) after removing the abdominothoracic viscera, jaw and anterior neck; they were then dehydrated in alcohol for 24 h, clarified in xylol and embedded in paraffin. Sections measuring 4 micrometers were obtained, mounted in synthetic resin and stained by the following methods: hematoxylin and eosin, cresylviolet (Nissl), and Holmes, for neurofibrils (16). Results
Observation of animals The mice showed onset of symptoms 3 days after inoculation, which intensified, after 5 days. They became apathetic, with bristling, dirty hair, being more exaggerated in group D, with a large number of dying animals being killed. Autopsy was performed on two-thirds of the total on the 4th and 5th days, with the remainder put to death 9 days following inoculation (at 44 days of age, 21 on protein-deficient diet). Histopathologic analysis Histologic lesions were mainly characterized by encephalomyelitis with selective topography at the level of the cerebral cortex, base nuclei, mesencephalon, and more rarely in the protuberance and cerebellar nuclei. Cortical and deep nuclei lesions were predominantly located in neuron cell bodies with chromatolysis, vacuolations, dysplasia and even neuronal necrosis, along with diffuse and focal microglial proliferation with neuronophagic figures, at times multiple and at times located 190
Exp. Pathol. 35 (1988) 3
paravascularly. On rare occasions there were necrotic areas with neuropile dissolution, usually located close to vessels (severe lesions + + +). In milder lesions (+), sparse neuronophagic foci with regressive neuronal changes were rarely found , and possibly in the cerebellum when it takes on a "glial shrub" appearance with Purkinje cell alterations. Less frequently found were small cortical vessels with endothelial tumefaction and mononuclear cuff with rare polymorphonuclear forms, as well as discrete mononuclear subarachnoid infiltrate. In only one case we did find subependymal
Fig. 1. Cerebral cortex showing diffuse and focal microglial proliferation with neuronophagic figures and discrete perivascular inflammatory cuff. H.E., X 100. glial lesions characterized by karyorrhexis. And only very rarely we found the scant presence of neutrophils , especially at the level of the necrotic lesions (fig. I, 2, 3 and 4). Medullar lesions were located at all levels and with variable predominance in the cervicothoracic and lumbar regions. These lesions were of varying intensity , being located with selective predominance at the level of the neurons of the anterior medullar tip (lesions from + to + + +). At this level , the neurons exhibited tumefaction, chromatolysis and necrosis with neuronophagic figures, and more rarely evident capillaries and endothelial tumefaction. Occasionally slight alterations with cellular retraction and discrete microglial proliferation could be seen at the level of the posterior columns. The posterior roots and dorsal ganglia showed no histological alterations. No lesions were found at the central canal level nor at that of the subarachnoid space. Other organs examined showed no histological changes related to viral aggression (table 2; fig. 5). Discussion
The correlative study of histological changes in undernourished animals suggests a clear predominance of the most serious and frequent lesions in undernourished animals inoculated through the peritoneum. There is also a correlation with findings of previous studies involving the piry virus (11). The role of malnutrition in the course of lesion development can therefore be affirmed. Low-intensity lesions in undernourished mice infected orally were less frequently observed, a finding we feel to be important in the analysis of lesion pathophysiology, making allowances for a probable epidemiologic correlation. Exp. Pathol. 35 (1988) 3
191
Table 2. Histopathologic lesions Mice aged 18 - 23 days inoculated with cocal virus Animals' number
Inoculation method
Dose
1223 N 1225 N 1227 N 1235 N 1241 D 1242 D 1247 D 1249 D 1250D 1251 D 1252 D 1253 D
peritoneal peritoneal peritoneal oral oral oral peritoneal peritoneal peritoneal peritoneal peritoneal peritoneal
0.25 0.25 0.25 0.25 0.25 0.25
rnl rnl rnl rnl rnl ml
0.25 0.25 0.25 0.25 0.25
rnl rnl ml rnl ml
Encephalitis
Myelitis WID lesions
+ ++ ++ ++ + + ++ ++ + +++ ++
+++ ++
7 4
++ + +++ ++
N = Normal diet; D = Undernourished; Fixative = FAM; Staining methods: H. E., Nissl, Holmes; No. animals examined: 48 (12 with and 12 without changes). 36 inoculated (l8N and 18D) with 12 not inoculated. 11 were unfit for evaluation. The finding of medullary lesions at the level of the anterior tip and more rarely in the posterior columns suggests the possibility of viral aggression stemming from initial peritoneal infection, by means of viremia and the penetration of nervous tissue by the posterior root region and dorsal ganglia where, according to BODIAN (1), HORSTMANN (12), BRIERLEY (2) an~ WAKSMAN (21), there is a break in the hematonervous and hematoganglial barrier. From this site of penetration, the virus would be capable of advancing through axons until reaching the anterior medullary tip with minimal lesions along its route through the dorsal and intermediolateral column (table 2). Conclusions
1. Experimental infection of mice by cocal virus shows definite central nervous system tropism provoking the histological condition of acute encephalomyelitis. 2. Lesions in undernourished animals are more frequent and of higher intensity than those given a normal diet. 3. In this study, perhaps for the first time ever, evidence was found of encephalomyelitis lesions from cocal virus by means of oral inoculation. 4. The histological picture, well-defined and constant, involving panencephalitis and acute anterior poliomyelitis during the effective period of oral and intraperitoneal inoculations and in addition to their increased seriousness in undernourished animals, allows for epidemiologic speculations in the case of Amazon arbovirus infections. 5. The experimental infection of mice by cocal virus provides an excellent model of encephalomyelitis for the future study of the pathophysiology, penetration and progress of the virus in the nervous system of experimental animals.
192
Exp. Pathol. 35 (1988) 3
Fig. 2. Base nucleus showing severe lesions with necrosis and neuron destruction. H.E., x 250.
Fig. 3. Cerebellar cortex showing Purkinje cell lesion and formation of "glial shrub". H.E., x450. Exp. Pathol. 35 (1988) 3
193
Fig. 4. Lateral ventricular ependyma showing karyorrhexis with subependymal glial lesions. H.E., X 250.
Fig. 5. Detail of anterior medullary tip with neuron lesions and neurophagia. Nissl's, 194
Exp. Pathol. 35 (1988) 3
X
450.
References 1. BOD!AN, D.: Polymyelitis. In: Pathology of the nervous system (ed. MINCKLER, J.), vol. 3, chapt. 170. McGrawHill, New York 1972. 2. BRIERLEY, J. B.: Acta Psychiatr. Scand. 1955; 30: 553. 3. BRUNO-LoBO, M., BRUNO-LoBO, G. G., PERALTAG, P. H., DE PAOLA, D.: Pathogenesis of vesicular stomatitis virus in the infant hamster and mouse. Ann. Microbiol. 1968; 15: 53-68. 4. BUCKLEY, S. M.: Applicability of the Hela (Gey) strain of human malignant epithelial cells to the propagation of arboviruses. Proc. Soc. Exp. BioI. Med. 1964; 116: 354-358. 5. CAMPOS, D. G., MAD!, K.: Estudos sobre desnutric;ao pre e p6s natal em ratos albinos. Parcial recuperac;ao ponderal e bioquimica. Rev. Bras. Pesq. Med. BioI. 1985; 8: 301-306. 6. DE PAOLA, D., MAD!, K., DUARTE, F., BRUNO-LoBO, G. G., BRUNO-LoBO, M.: Alterac;6es histoquimicas em ratos desnutridos inoculados com virus Oriboca. Ann. Microbiol. 1972; 19: 13-19. 7. - : Interac;ao virus-celula. Introduc;ao de modelos experimentais de infec<;ao arboviral. Gernasa Ed., Rio de Janeiro, RJ 1973. 8. DITCHFIELD, J., ALMEIDA, J. D.: The fine structure of cocal virus. Virology 1964; 24: 232-235. 9. DONALDSON, A. 1.: Am. J. Epidemiol. 1970; 92: 132. Cited in: Internat. cataloque of arbovirus (ed. BERGE, T. 0.), 2nd ed. Dept. of Health, Education and Welfare, Atlanta 1975. 10. FEDERER, K. F., BURROWS, R., BROOKSBY, J. B.: Vesicular stomatitis virus. The relationship between some strain Indiana serotypes. Res. Vet. Sci. 1967; 8: 103-117. II. GOES, P., DE PAOLA, D., DUARTE, F., MAD!, K., CABRAL, M. C.: Estudos sobre os arbovirus. XVIII. Acao experimental do virus Piry em camundongos desnutridos. Ann. Microbiol. 1981; 26: 7-18. 12. HORSTMANN, D. M.: Am. J. Med. 1949; 6: 535. 13. JONKERS, A. H. et al.: Am. J. Vet. Res. 1965; 26: 758-763. Cited in: Internat. cataloque of arbovirus (ed. BERGE, T. 0.), 2nd ed. Dept. of Health, Education and Welfare, Atlanta 1975. 14. - SPENCE, L., COAKWELL, C. A., THORNTON, J. J.: Laboratory studies with rodents and viruses native to Trinidad. I. Studies on the behavior of cocal virus. Am. J. Trop. Med. Hyg. 1964; 13: 613-619. 15. - SHOPE, R. E., AITKEN, T. H. G., SPENCE, L.: Cocal virus: a new agent in Trinidad related to vesicular stomatitis virus, type Indiana. Am. J. Vet. Res. 1964; 25: 236-242. 16. LUNA, G. L.: Manual of histologic staining methods of the Armed Forces Institute of Pathology. 3rd. ed. McGraw-Hill, New York 1968. 17. MAD!, K.: Contribic;ao 11 confecc;ao de urn modelo experimental de deficiencia proteica. Thesis, Univ. Rio de Janeiro 1970. 18. - JERVIS, H., ANDERSON, P. L., ZIMMERMANN, M. L.: A protein-deficient diet: effect on the liver, pancreas, stomach and small intestine of the rat. Arch. Pathol. 1970; 89: 38-52. 19. NOZAWA, C. M.: Relacionamento sorologico entre os differentes virus do grupo da estomatite vesicular. Master's thesis, Ed. Inst. Microbiol., UFJR 1976. 20. WOODALL, J. P.: Virus research in Amazonia. Atas do Simp6sio sobre a Biota Amazonica. 1967; 6: 31-63. 21. WAKSMAN, B. H.: J. Neuropathol. Exp. Neurol. 1961; 20: 35. (Received May 16, 1988; Accepted May 24, 1988)
Exp. Pathol. 35 (1988) 3
195