THE BEHAVIOR OF POX VIRUSES IN THE RESPIRATORY TRACT : II. THE RESPONSE OF MICE TO THE NASAL INSTILLATION OF VARIOLA VIRUS

Variola virus was cultivated in embryonated eggs from smallpox crusts and maintained through 85 passages. Therein it produced foci of cellular proliferation and necrosis on the chorioallantoic membrane but did not affect the embryo. The virus from egg cultures was inactive in the skin of the rabbit on primary injection and in the testis both initially and on passage. In the monkey it provoked a cutaneous eruption of short duration after an incubation period of 5 days. On nasal instillation in the mouse the virus caused no symptoms and failed to survive on the mucous membrane of the upper air passages. Beginning with the 64th egg passage it was regularly recoverable from the lung, on subinoculation in eggs, through the 5th day and occasionally through the 7th day. Its presence in the lung was attended by progressive pathological changes.     

THE BEHAVIOR OF POX VIRUSES IN THE RESPIRATORY TRACT : IV. THE NASAL INSTILLATION OF FOWL POX VIRUS IN CHICKENS AND IN MICE

Fowl pox virus from active skin lesions was established in the upper respiratory tract of normal chickens by nasal instillation and maintained for 12 successive passages. The nasal infection was not communicable by direct contact but did afford protection, for at least 6 weeks, against subsequent development of the virus in the skin. Multiplication of the virus in the nasal passages was only irregularly attended by specific mucosal changes and was not accompanied by the vigorous counter-reaction engendered by the causal agents of roup. The same strain of virus on propagation in embryonated eggs also survived and multiplied in the nasal tract but with somewhat reduced activity, the 34th egg transfer failing to afford complete protection. Nasal instillation in mice was followed only by a reaction in the lung from which the virus was recoverable through the 7th day.     

STUDIES ON THE ETIOLOGY OF RABBIT POX : III. TESTS OF THE RELATION OF RABBIT POX VIRUS TO OTHER VIRUSES BY CROSSED INOCULATION AND EXPOSURE EXPERIMENTS

Experiments are reported in which it was shown that rabbits which had recovered from experimental or spontaneous rabbit pox were refractory to inoculation of pox virus injected by various routes, and in addition did not develop clinical manifestations of the disease under conditions of exposure to florid cases of pox. It was found that pox recovered rabbits were susceptible to inoculation with the virus of virus III disease of rabbits and that virus III recovered rabbits could be successfully inoculated with pox virus. Furthermore, virus III recovered rabbits developed pox when subjected to room exposure in the same manner as did normal rabbits. It thus appears that there is no specific relationship between the two viruses. Rabbits which had recovered from experimental or spontaneous pox were found to be just as susceptible to inoculation with the virus of infectious myxoma of rabbits as were normal rabbits, a result which demonstrates that there is no specific relationship between these viruses. Rabbits which had recovered from experimental or spontaneous pox were refractory to inoculation with culture dermovaccine virus, but vaccine recovered rabbits were not completely refractory to inoculation with pox virus. Under conditions of exposure to clinical cases of pox, adult vaccine immune rabbits did not develop clinical manifestations of pox, but young, recently weaned vaccinated rabbits did contract mild but definite clinical pox. Experimental pox recovered rabbits were partially refractory to inoculation with neurovaccine virus and neurovaccine recovered rabbits were partially refractory to inoculation with pox virus. The refractory condition of the pox immune rabbits appeared to be more pronounced than that of the neurovaccine immunes. The cutaneous lesions which developed from the intradermal injection of pox, neurovaccine, and culture vaccine viruses showed definite differences with respect to the rate and persistence of active growth, amount of edema, hemorrhage, and necrosis, and the degree of tissue destructiveness. These features were most pronounced in the lesions of pox virus and were least marked in the lesions of culture vaccine virus. The differences were particularly apparent in normal rabbits, but they were also present in the lesions which developed in immune animals. It was found that the calf was susceptible to inoculation with pox virus applied to a scarified skin area. There were many similarities in the appearance and course of the pox lesions to those resulting from culture vaccine virus, the New York Board of Health vaccine, and neurovaccine virus similarly inoculated. But the pox lesions were most numerous, much the largest and most destructive, and by far the most persistent while next in order were those of the Board of Health dermovaccine. The results of these various experiments showed that a close relationship obtains between pox virus, on the one hand, and vaccine virus and neurovaccine virus, on the other, but it cannot be said that pox virus is identical in all respects with either one of these viruses. The findings indicated that the relationship between pox and neurovaccine viruses is closer than that between pox and culture vaccine viruses. Upon the basis of the results observed in culture (dermo) vaccine immune rabbits inoculated with or exposed to pox, it appeared that vaccination with vaccine virus offered a method of protection against rabbit pox.     

SWINE INFLUENZA : II. A HEMOPHILIC BACILLUS FROM THE RESPIRATORY TRACT OF INFECTED SWINE

1. A hemophilic bacillus has been regularly obtained in culture from the respiratory tract of a series of swine experimentally infected with swine influenza and from a small number of spontaneous field cases of the disease. It has not been observed in respiratory tract cultures from a group of swine free from influenza. 2. The cultural and morphological characters of the organism have been described and the name Hemophilus influenzas (variety suis) suggested. The organism exhibits marked serological diversity, since only two out of eight strains studied were serologically identical. It is usually non-pathogenic for rabbits and white rats, and irregularly pathogenic for white mice. One strain of the organism was pathogenic for guinea pigs while two others were not. 3. Eleven out of thirteen attempts to induce symptoms of disease in swine by intranasal inoculation with pure cultures of H. influenzae suis were entirely negative. The remaining two attempts which suggested a positive result have been discussed. 4. Attention has been called to the marked similarity which exists between non-indol-producing strains of H. influenzae and H. influenzae suis.     

EXPERIMENTS ON THE SURVIVAL OF THE FEBRILE HERPETIC AND ALLIED VIRUSES IN VITRO

These studies fail to confirm the statements previously made that microorganisms of the class of the globoid bodies of poliomyelitis may be cultivated in the Smith-Noguchi medium from the so called virus of encephalitis lethargica. They show equally that the herpes virus does not multiply in this medium. The experiments indicate, moreover, that the medium is unfavorable to the survival of the virus, while ordinary broth under aerobic conditions is more favorable for maintaining the activity of both the encephalitic and the herpes viruses. Probably no multiplication of either takes place in the latter medium but merely a survival, and for a maximum period of 6 days in the broth itself, and 12 days in the fragment of brain tissue immersed in the broth. Finally, it has been shown that with a suitable technique the viruses can be passed from the brain of one rabbit to that of another through a long series without contamination with cocci or other common bacterial forms. Hence we regard all reports of the finding of ordinary bacteria in the brain of cases of epidemic or lethargic encephalitis as instances of mixed or secondary infection arising during life, or examples of postmortem invasion of the body, or of faulty technique at the autopsy.     

GENERAL ALVEOLAR HYPOVENTILATION: A SYNDROME OF RESPIRATORY AND CARDIAC FAILURE IN PATIENTS WITH NORMAL LUNGS

Chronic alveolar hypoventilation has been considered in termsof its pathogenesis. Distinction has been made between generalalveolar hypoventilation, which arises from failure of the ventilatoryapparatus, and net alveolar hypoventilation which is secondaryto bronchopulmonary disease. Examples are presented to ifiustratethe pathogenesis of general alveolar hypoventilation in variousdisorders of the ventilatory apparatus. The common end-pointsfor all of these are arterial hypoxaemia and hypercapnia; theseabnormalities in the blood gases are responsible for the cardiorespiratoryfailure of chronic alveolar hypoventilation. However, the clinicalexpression of these abnormal blood gases is modified by thepathogenetic background: in failure of the respiratory centre,the consequences of arterial hypoxaemia and hypercapnia aremanifest in the purest forms, free of the complications of abnormallungs or mechanics of breathing; in severe kyphoscoliosis, thecompressed distorted lung restricts the pulmonary hypertensionand cor pulmonale; in obesity, the hypermetabolic and hypervolemicstates provide a background of left ventricular, as well asright ventricular overload, for the consequences of arterialhypoxaemia and hypercapnia. The clinical importance of recognizingthe syndrome of general alveolar hypoventilation lies in itsreversibility following adequate relief of the hypoxaemia andhypercapnia. ² At present Fellow of the Commonwealth Fund at the NuffleldInstitute for Medical Research, Oxford, England.     

MULTIPLICATION AND SPREAD OF THE VIRUS OF ST. LOUIS ENCEPHALITIS IN MICE WITH SPECIAL EMPHASIS ON ITS FATE IN THE ALIMENTARY TRACT

1. Beginning at 24 hours after intravenous injection of about 10 million intracerebral LD₅₀ of virus there was evidence of simultaneous, progressive multiplication in the brain and intestinal tract. 2. When the virus was introduced directly into the brain or the nasal cavities and mouth, none was found in the intestinal tract until there was general centrifugal spread from the central nervous system during the last stages of the infection at 96 or 120 hours after inoculation when the virus in the entire brain had reached a concentration of about 3 billion LD₅₀. 3. Centrifugal spread began when the virus in the brain reached a concentration of about 400 million LD₅₀ and virus appeared in the pharynx, tongue, and adrenals before it was demonstrable in the intestinal tract, blood, or viscera such as the spleen, liver, and kidneys. 4. Despite the high concentrations of virus which developed in the intestinal tract following intravenous inoculation, it was not demonstrable in the stools, differing in this respect from Theiler''s virus in mice and poliomyelitis virus in human beings and monkeys. 5. No antiviral agent was found in the stools, but the urine of normal mice having a pH of 5.6, inactivated large amounts of St. Louis encephalitis virus. 6. There was no evidence of multiplication in the nasal mucosa of mice which succumbed with encephalitis following nasal instillation of the virus, the course of events being comparable in this respect to the behavior of the M.V. poliomyelitis virus in rhesus monkeys. 7. At the terminal stage of infection the virus content per milligram of tissue was as great in the leg muscles as in the sciatic nerves. Since this was also true for the urinary bladder, heart, lungs, and tongue among other tissues, and since the amount in the blood was too negligible to account for it, it would appear that the virus either accumulated in these tissues by diffusion from the nerve fibers, along which it was spreading from the central nervous system, or that it multiplied in some constituent other than the nerve fibers.     

REACTIONS OF RABBITS TO INTRACUTANEOUS INJECTIONS OF PNEUMOCOCCI AND THEIR PRODUCTS : VII. THE RELATION OF HYPERSENSITIVENESS TO LESIONS IN THE LUNGS OF RABBITS INFECTED WITH PNEUMOCOCCI

1. The intratracheal injection of egg albumin or pneumococcus protein induces an inflammatory reaction in the lungs of rabbits previously inoculated with the respective antigen. 2. A similar reaction occurs following intratracheal injection of pneumococcus protein into the lungs of rabbits previously inoculated with heat-killed suspensions of the bacteria. 3. This reaction appears to be related to the presence of circulating antibody and to have the nature of the Arthus reaction. 4. A study of the reaction of the lung of rabbits to infection caused by intravenous injections of Pneumococcus reveals that (a) reactions occur irregularly in the lung; (b) in the lungs in which reactions do occur, the histological changes are not different in normal rabbits and in rabbits made resistant by previous intravenous or intracutaneous injections of pneumococci. 5. Intratracheal injection of pneumococcus protein followed by intravenous injection of virulent pneumococci on the next day does not alter the course and character of the infection in resistant rabbits. 6. The experiments reported in this paper bring no evidences to support the view that the lesions in the lungs of rabbits following the intravenous injection of pneumococci are modified by any previous state of sensitivity.     

THE ENHANCING EFFECT OF CONCURRENT INFECTION WITH PNEUMOTROPIC VIRUSES ON PULMONARY TUBERCULOSIS IN MICE

The course of pulmonary tuberculosis in the mouse appears to be accelerated as a result of concurrent infection of the lung with either of two pneumotropic viruses. This effect is obtained with virus inocula sufficiently small as to induce little or no definite viral pneumonia.     

VIRUS-INDUCED DIABETES MELLITUS : I. HYPERGLYCEMIA AND HYPOINSULINEMIA IN MICE INFECTED WITH ENCEPHALOMYOCARDITIS VIRUS

Infection of DBA/2N male mice with encephalomyocarditis virus resulted in a diabeteslike syndrome characterized by hyperglycemia, glycosuria, hypoinsulinemia, polydipsia, and polyphagia. Blood glucose levels were elevated within 4 days after infection and reached a maximum mean level of 320 mg/100 ml within 12 days. Approximately 60–80% of the animals developed a transient hyperglycemia while 10–15% of the animals remained hyperglycemic for well over 6 mo. The remaining animals failed to become hyperglycemic but many had abnormal glucose tolerance curves. Hyperglycemia was most pronounced when animals were allowed free access to food, and the incidence of byperglycemia was related both to the strain and sex of the animals, with few females developing hyperglycemia. The amount of immunoreactive insulin in the plasma of infected hyperglycemic mice was significantly lower than in appropriate controls, and injection of exogenous insulin resulted in a rapid drop in the blood glucose levels. Despite the fact that certain animals were hyperglycemic for many months, virus could not be recovered from the pancreas after the first 10 days of the infection.     

SPECIFICITY OF THE INFLAMMATORY RESPONSE IN VIRAL ENCEPHALITIS : I. ADOPTIVE IMMUNIZATION OF IMMUNOSUPPRESSED MICE INFECTED WITH SINDBIS VIRUS

The viral-induced perivascular inflammatory response in Sindbis virus encephalitis of mice was shown to be immunologically specific. Mice were inoculated intracerebrally with Sindbis virus, and 24 hr later a single dose of cyclophosphamide was given which ablated the inflammatory response. 3 days after virus inoculation, cells and/or sera from specifically and nonspecifically sensitized donor mice were given, and the inflammatory reactions, virus content, and antibody response of recipients were examined 5 days later. Reconstitution of the viral inflammatory response required virus-specific sensitized lymph node cells and was enhanced when these lymph node cells were combined with bone marrow cells. Reconstitution was not achieved with Sindbis virus immune serum even when combined with nonspecifically sensitized cells. Combination of immune serum with Sindbis virus-sensitized cells did not produce an accentuation of the reaction. In distinction, reconstitution of the inflammatory reaction surrounding the stab wound was reconstituted with bone marrow cells from mice inoculated with Sindbis virus or control antigens. Reconstitution of the perivascular reaction was associated with a reduction in brain virus content. Although the transfer of Sindbis virus-sensitized lymph node cells and bone marrow cells resulted in the limited production of neutralizing antibody in the immunosuppressed recipient, the reduction in virus was significantly greater with the transfers of Sindbis virus-sensitized lymph node cells than with the passive transfer of immune serum alone.     

反复呼吸道感染儿童血浆MBL水平及基因突变特征

目的探讨血浆甘露聚糖结合凝集素（MBL）水平及基因多态性与儿童反复呼吸道感染（RRTI）的关系。方法选择110例RRTI儿童及111例健康儿童（均为汉族）为研究对象。应用酶联免疫吸附试验（ELISA）方法检测其血浆MBL水平,聚合酶链反应-限制性片段长度多态性（PCR-RFLP）方法检测MBL基因第一外显子54密码子、57密码子基因型和多态性。结果 RRTI儿童血浆MBL水平显著低于健康儿童组（t=7.19,P〈0.01）;各年龄段RRTI儿童血浆MBL水平均明显低于同年龄段健康儿童组（t=2.15～3.55,P〈0.05、0.01）,但RRTI儿童各年龄段间比较差异无显著性（P〉0.05）。RRTI组MBL水平低下者检出率（23%）显著高于健康儿童组（6%）（χ2=9.12,P〈0.01）,MBL基因第一外显子54密码子基因型GGC/GGC、GGC/GAC、GAC/GAC分别对应高、中及低血清MBL水平。RRTI组MBL基因第一外显子54密码子等位基因GAC及GGC/GAC型突变杂合子频率显著高于健康儿童组（χ2=4.47～5.64,P〈0.05）。两组均未检出57密码子突变个体。结论 MBL缺陷是RRTI的重要原因,与低MBL水平相关的MBL基因第一外显子54密码子等位基因GAC是儿童RRTI的危险因素。     

STUDIES ON THE RELATION BETWEEN TUMOR SUSCEPTIBILITY AND HEREDITY : IV. THE INHERITANCE OF SUSCEPTIBILITY TO TAR-INDUCED TUMORS IN THE LUNGS OF MICE.

Evidence has previously been submitted in favor of the theory that susceptibility to spontaneous tumors of various types is inherited. The question arose whether susceptibility to tumors induced by tar could be shown to be hereditary by experimenting with the same strains of mice which had already been shown to differ significantly in respect to their spontaneous tumor rates. Two strains of mice were selected for observation. One strain, the Bagg albinos, has a low rate of mammary gland tumors but a higher rate of spontaneous lung tumors. The other strain, No. 1194, agouti, has a higher rate of mammary gland tumors but a lower rate of tumors of the lung. A previous test showed no difference in the percentages of skin tumors which arose after tar painting. It has already been shown that the difference in the lung tumor rates is mathematically significant. When the two stocks are treated with tar by applying the irritant, not in the same spot, but on different areas successively, the percentage of lung tumors is increased in each stock, Text-fig. 11. The rate of the Bagg albinos increased from 37.04 to 85 per cent, that of Strain 1194 from 6.73 to 22 per cent. But a difference between them is still maintained, and this difference also is significant mathematically. When the two strains are crossed and the offspring subjected to the tar treatment, the latter give a high percentage of lung tumors—79 per cent in 28 individuals—about the same as the parental high tumor strain. When the F₁ sons are backcrossed to the original See PDF for Structure stocks, the cross to the high tumor strain maintains the high tumor rate, 81 per cent in 37 mice, while in the cross to the low tumor strain the percentage drops to 39 per cent in 38 mice. This result indicates that susceptibility to tar-induced tumors in the lung is hereditary. The number of factors concerned has not yet been ascertained. Possibly one or more of them is dominant. In general, the conception that susceptibility to pulmonary tumors is hereditary seems to be upheld by the fact that the two strains of mice described differ conspicuously in respect to spontaneous tumor rates under ordinary laboratory conditions; the strains differ also under experimental conditions, as described in this report; and when crossed, their offspring by suitable backcrosses, will again show significant differences.     

THE DEMONSTRATION OF LESIONS AND VIRUS IN THE LUNGS OF MICE RECEIVING LARGE INTRA-PERITONEAL INOCULATIONS OF EPIDEMIC INFLUENZA VIRUS

Following the intraperitoneal inoculation of mice with large doses of epidemic influenza virus (50,000 to 1 million intranasal M.L.D.) it can be recovered from the lungs in high concentration, and pulmonary lesions of moderate extent may be observed. The virus reaches its highest titer in the lungs 48 to 72 hours after intraperitoneal injection and may persist for 10 days. Virus may be recovered from the blood in the first 24 hours, but is readily detected in the omentum and peritoneum for 5 to 6 days. Mice which as a result of the intraperitoneal injection of virus show a high concentration of virus in the lungs do not die but become solidly immune to intranasal infection. Moreover, as early as 24 to 48 hours after intraperitoneal inoculation of large amounts of virus the animals may exhibit resistance to infection with fatal doses of virus given intranasally. Influenza virus given intravenously to mice is rapidly removed from the blood but persists in the lungs and induces pulmonary lesions. Virus can also be recovered from the liver for several days. With subcutaneous inoculation of influenza virus, however, the virus does not reach the blood or lungs in detectable amounts although the regional lymph nodes may yield considerable quantities of the agent. A brief consideration is presented of the mechanisms of infection and resistance which may be involved.     

STUDIES ON THE PROPAGATION IN VITRO OF POLIOMYELITIS VIRUSES : III. THE PROPAGATION OF POLIOMYELITIS VIRUSES IN TISSUE CULTURES DEVOID OF NERVE CELLS

Cells like fibroblasts, having no resemblance whatever to nerve cells were obtained in morphologically pure cultures from monkey testicular tissue and were found to support the growth in vitro of poliomyelitis virus, Type 2, Yale-SK strain. Moreover, these cells were destroyed as a result of the multiplication of this virus within them. Similarly, "fibroblasts" propagated in primary explant cultures of testicle were destroyed by poliomyelitis viruses, Types 1 and 2. Type specific antibodies neutralized the pathogenic effect of poliomyelitis virus on monkey testicular fibroblasts.     

GENETIC INFLUENCES AFFECTING THE OCCURRENCE OF A DIABETES MELLITUS-LIKE DISEASE IN MICE INFECTED WITH THE ENCEPHALOMYOCARDITIS VIRUS

The M variant of encephalomyocarditis virus produces a diabetes mellitus-like disease in DBA/2 mice but not in animals of the C3H strain. Fewer than one-third of infected F₁ (DBA/2 x C3H) progeny exhibit the disease, whereas the prevalence in backcrosses (F₁ x DBA/2, F₁ x C3H) is comparable to the parental inbred strain. Thus, the mode of inheritance of the diabetic predisposition appears to be polygenic. DBA/2 animals develop striking inflammatory and necrotizing lesions of the islets of Langerhans; in contrast, alterations of the insular tissue in the C3H mice are minimal. Although metabolic abnormalities appear to be consequent to lesions of beta cells, the factors influencing the severity of these insular changes are incompletely understood.     

STUDIES ON THE ETIOLOGY OF RABBIT POX : IV. TESTS ON THE RELATION OF RABBIT POX VIRUS TO OTHER VIRUSES BY SERUM NEUTRALIZATION EXPERIMENTS

The results of serum neutralizing tests with the viruses of pox, vaccinia, and virus III disease herewith reported generally agree and supplement the results of reinoculation experiments on immune rabbits reported in the previous paper (1). The finding that pox virus is neutralized by pox immune serum indicates that the refractory state of recovered pox rabbits to reinoculation with pox virus and the failure of recovered pox rabbits to contract a second pox infection after adequate exposure is to be explained upon the basis of the development of an active immunity. The failure of virus III immune serum to neutralize pox virus is in agreement with the previous conclusion drawn from the positive results of reinoculation and exposure experiments that there is no specific relationship between pox virus and virus III. Rabbits which had recovered from a pox infection were completely refractory to inoculation with dermo-(culture) vaccine, while rabbits which had recovered from vaccinia were partially refractory to inoculation with pox virus. Vaccine immune adult rabbits did not show any clinical evidence of pox upon exposure to florid cases, but young recently weaned vaccine immunes developed definite although comparatively mild pox infections. The serum neutralization tests showed that pox immune serum neutralized vaccine virus although the action was not complete as shown by the positive results obtained with high dilutions of serum; vaccine immune serum possessed some but comparatively slight neutralizing properties against pox virus. The results of the crossed inoculation and serum neutralizing experiments with pox and neurovaccine viruses resembled those obtained with pox and dermo-(culture) vaccine but the differences were less pronounced. The differences in virus neutralizing ability on the part of the three immune sera paralleled the differences in virus potency as indicated by the character of the local lesions at the site of injection and by the general character of the clinical manifestations of the infection. The potency or virulence of pox virus was much greater than that of neurovaccine and vastly greater than that of dermo-(culture) vaccine. The complete identity of pox and vaccine virus could not be established, but a definite relationship between them was demonstrated and this was shown to have an immunological basis. From a practical standpoint vaccination with vaccine virus as a prophylactic measure against rabbit pox was clearly indicated.