ABSTRACT
Infrared radiation and 1-2 micron microwaves influenced the infectivity of Newcastle Disease Virus (NDV) upon chick embryo tracheal tissue in such a way that the expected destruction of ciliated epithelium turned out to be incomplete or did not take place at all, respectively. Due to the fact that direct damaging of viruses following such radiation was not shown and that it was our intention to arrange the experimental set-up as if natural rhinolaryngeal conditions had induced the infection of the mucous membrane of the respiratory tract a study was performed in order to establish the radiation influence on mediator substances involved in the virus infection of mucous membranes. The mucopolysaccharides, chondroitine sulphate and hyaluronic acid, as well as mucin served as models; in addition protamine sulphate was used for reasons of comparison. The influence of the above substances upon NDV-infection in organ cultures and the effect of electromagnetic waves upon such influence were studied. By choosing a virus concentration of 10(-8)/ml on chick embryo tracheal tissue it was established that the application of infrared radiation (Osram Siccatherm Infrared Radiator,- 1-2 micron) and cm-waves (Klystron Raytheon Comp. Mass. USA, - 1.35 cm) for a length of 10 min. inhibited Newcastle Disease Virus (NDV) infectivity. The suspension fluid was treated with infrared and the tissue with cm-waves. Previous experiments revealed that direct radiation influence upon viruses cannot be taken for granted which is why the agents, chondroitine sulphate (polyanion) 5-10 microgram/ml, and hyaluronic acid (polyanion) 10-50 microgram/ml, were used in order to study such influence upon NDV-infected tracheal mucous membrane. In addition, protamine sulphate (polycation), 5-10 microgram/ml, and mucin were used. All the above mentioned substances influenced viral infectivity in organ cultures-expressed in terms of quotients: quotient 1 means no influence on the motility of the ciliated mucous membrane cells and quotient 0.01 means the complete destruction of the cells. Chondroitine sulphate inhibited strong but promoted weak virus infectivity, hyaluronic acid inhibited strong virus infectivity, protamine sulphate inhibited strong but promoted weak virus infectivity and mucin promoted weak virus infectivity in accordance with the used virus concentrations (Table 2). Under the influence of infrared radiation the mediator substances exercised a different influence upon viral infectivity: 25 times out of 32 experiments chondroitine sulphate was inhibited and hyaluronic acid increased in 8 out of 12 experiments (Table 2). The influence of protamine sulphate on viral infectivity was found to be increased 39 times and inhibited 14 times out of 54 experiments, mucin was inhibited 6 times. Furthermore, it is to be added that additional radiation with cm-waves increased the influence of infrared radiation (Table 1)...
Subject(s)
Glycosaminoglycans/radiation effects , Infrared Rays , Microwaves , Mucins/radiation effects , Newcastle disease virus/radiation effects , Protamines/pharmacology , Adsorption , Animals , Chick Embryo , Chondroitin Sulfates/pharmacology , Chondroitin Sulfates/radiation effects , Hyaluronic Acid/pharmacology , Hyaluronic Acid/radiation effects , Mucins/pharmacology , Newcastle disease virus/growth & development , Organ Culture TechniquesABSTRACT
A loss of nerve cells in the cortex after encephalitis was reported already in the classical work by Nissl, Spielmeyer, and Spatz. A loss of nerve cells will become only noticeable if it amounts to at least 50%. But as such clear pictures are rarely found, estimations were always considered as doubtful and incorrect. Not only the number of cells is important in consideration of the morphological change in the cortex but also the size of cells. The development of a new apparatus made is possible to consider two structural parameters: the surface and the perimeter of cells. In 497 histological serial preparations obtained from 43 mouse brains we determined the number, the surface, and the perimeter of nerve cells. 39 animals were infected intracerebraly with yellow fever 17 D; 4 normal animals served as controls. Among the infected animals, 8 were treated with a mucopolysaccharide. The cells were counted within a determined area (standard unity); this area was taken from the angle between the curbura exterior and the sulcus anterior-posterior of the brain. There was a significant difference between the number of nerve cells in normal (278) and in infected (202) animals. The animals treated with mucopolysaccharide showed a normal quantity of nerve cells but surface and perimeter corresponded to the data of the infected ones. The surface of normal animals was at 23.39, that of infected at 14.29. There was also a significant difference with regard to the cell perimeter: normal 14.97, infected 12.02. This means a shrinking of cells. The cell shrinkage revealed that the nerve cells were affected. The measurement of these three parameters presents new and exact statistical findings which enable a reconsideration of neurovirulence.
Subject(s)
Cerebral Cortex/pathology , Encephalitis/pathology , Glycosaminoglycans/therapeutic use , Neurons/pathology , Yellow Fever/pathology , Animals , Cell Count , Computers , Encephalitis/drug therapy , Histological Techniques/instrumentation , Mice , Sulfuric Acids/therapeutic use , Yellow Fever/drug therapyABSTRACT
The counting of nerve cells give an answer to the question whether there is a significant loss of cells in the cortex in the course of viral encephalitis. For normal animals, average cell numbers of 275.42 were counted; for infected animals divided into two groups depending on the severity of illness, 144.95 and 192.87 cells, respectively (p = 0.0001).
Subject(s)
Cerebral Cortex/pathology , Encephalitis/pathology , Neurons/pathology , Yellow Fever/pathology , Animals , Behavior, Animal , Cell Count , Encephalitis/physiopathology , Life Expectancy , Mice , Yellow Fever/physiopathologyABSTRACT
The behavior of 1,072 mice that had recovered from encephalitic infection with intracerebrally injected yellow fever virus 17D and of 216 normal mice was tested in a maze and on a horizontal rod rotating around its axle. Infected animals needed more time (average, 8.90 min) to find their food in a maze than did normal animals (average, 4.37 min). Infected mice were able to stay on the rotating rod for a shorter time (average, 6.4 seconds) than were normal animals (average, 9.0 seconds). The correlation between the concentration of virus injected and the performance of the mice was confirmed by the extent of lesions found by histologic study: animals that had anatomic lesions after surviving encephalitic infection showed abnormal behavior.
Subject(s)
Brain Damage, Chronic/etiology , Encephalitis/complications , Learning Disabilities/etiology , Animals , Brain Damage, Chronic/pathology , Humans , Rats , Yellow fever virusABSTRACT
The archives of the Robert Koch Institute include a casket with preparations and handwritten notes by Robert Koch (Fig. 1). He made these preparations during his time as a rural doctor between October of 1878 and September of 1880. They refer to an outbreak of sheep-pox at Rackwitz, a place near his practice at Wollstein (Fig. 2). This work has not been published; we know of it from one of Robert Koch's private letters (11). To reconstruct his working scheme and reasoning, we consulted particularly his reports on rinderpest experiments which he began in 1896 (6). The preparations from this casket which had been stained with Bismarck brown (according to Weigert) date back to a period when Robert Koch developed the foundations of bacteriology and they are evidence of his preparedness to accept new operational procedures (1, 2, 3). Thus, we have to assume that these preparations were to serve as evidence of a bacteriological etiology of sheep-pox. A wrong conclusion as to associations between the superinfection present and etiology of the disease (7) was ruled out by maintaining his own postulate. Simultaneously with this preparation work, Robert Koch performed animal experiments (11). His experience from these studies was utilized later on in his rinderpest experiments (6). On account of his confrontation with viral disease - which had its starting point in his unpublished work on sheep-pox - Robert Koch stated his postulate to be valid in the same manner as if bacteriological etiology had been demonstrated (4,6). The importance of these preparations is also seen in the interpretation of viral tissue damage, i.e. increase of macrophages and plasma cells with subsequent necrosis (9) characteristic of vira infection (Figs. 3, 4).
Subject(s)
Ecthyma, Contagious/history , Virology/history , Animals , Ecthyma, Contagious/microbiology , History, 19th Century , SheepABSTRACT
Viral encephalitides in infants are very often followed by serious mental manifestations. To be able experimentally to investigate this pathological phenomenon, we established the following model. Mice having recovered from an intracerebral infection with yellow fever virus 17 D (routine test for the potency of yellow fever vaccine) and giving the impression of normal and healthy animals were examined for their psychical behaviour. As unit of measurement we took the time for running through a labyrith (fig. 1). At the entrance of the labyrith in a box there was placed the population of animals of one cage (6 animals in maximum) and at the opposite side there was deposited the food. The animals going to be examined had been without food for 24 hours. The time was taken having passed from the moment of placing the animals up to the moment of their nibbing at the food. We examined 11 groups of mice having past routine tests for the potency of the yellow fever vaccine. One of them had been tested twice at an interval of 54 days (table 1). The 791 mice which had passed the encephalitic infection showed an average running time of 8.90 min. The 164 controls, however, had an average running time of 4.37 min (table 2). This difference is significant (p=greater than 1/1000). The average running time is proportional to the injected virus quantity (table 3). The significance of each single virus dilution to the group of normal animals is always greater than 1/1000. The significance is more than 1/100 for each single virus dilution between 10(-1) and 10(-3) compared with the virus dilution of 10(-5). Immediately after the clinical period (21 days), no difference could be observed between the single virus dilutions. After 76 days only, the test showed the above mentioned differences (table 4). Therefore, the mice having found their food after a long running time had more serious postencephalitic lesions than those having had a shorter running time. To prove this statement, we examined histologically brains of 14 mice which had found their food after 20 min on an average and those of 16 mice having had an average running time of 6.58 min. The histological evaluation was performed in regard to eight pathological characteristica. The results were recorded on tables for each slide with a histological preparation. For this we used squared paper (fig. 2, 3). For each brain of mice, the so-called "index of lesions" was calculated by the proportion of labelled and all squares. .....
