Specific Infectious Agents Research Articles

Granulombildungen in der Lunge des Huhnes

The granuloma is a significant form of inflammatory response in chickens, and the various bacteria, fungi, viruses and protozoa which elicit granulomas are discussed. The granuloma is a frequent and important lesion of the lung in chickens, the inciting infection reaching this organ by the hematogenous or aerogenous route. The anatomy of the avian respiratory tract influences the pathogenesis of granulomatous inflammation; these anatomic features are described. It has not yet been determined whether any pulmonary necrosis, given sufficient time, can develop into a granuloma, or whether the process requires the participation of certain specific infectious agents.

Nonspecific spondylitis of infants and children.

It is our purpose to present 6 cases of self-limited spondylitis of infants and children. All were characterized by failure to identify a specific infectious agent, a mild clinical course, positive roentgen findings, and recovery without antibiotics. The radiographic findings were indistinguishable from those of pyogenic osteomyelitis of the spine. In 1950 Saenger reported 4 cases of spondylarthritis in children, with systemic signs of infection but negative diagnostic tests for a specific infective agent (16). The radiographic changes, consisting in narrowing of an intervertebral disk space and mild destructive lesions in the contiguous surfaces of the involved vertebral bodies, were progressive for one to two months and then regressed over another two to eight months, with only partial restoration of a normal picture. Saenger pointed out that Smith had reported a group of similar cases in 1933 in adults. Reference was also made to a paper by Ghormley et al. in 1940 (7), in which an analogous syndrome was described under the title “Acute Infectious Lesions of the Intervertebral Disks,” but again most of the patients were adults. Dupont and Andersen (5), in 1956, reported 4 cases of what they called “nonspecific spondylitis in childhood,” with an age range from twenty-one months to nine years. The illness pursued a subacute course and manifested the same radiographic changes and time sequence as Saenger's cases. Dupont and Andersen also emphasized the four clinical syndromes which spondylitis may assume. The first and most usual is back pain with spinal muscle spasm; the second is the hip joint or hip-leg syndrome with limitation of weight-bearing due to pain in the hip or leg plus flexion contracture of the thigh; the third is the abdomen-chest syndrome; the fourth is the meningeal, with stiff neck and positive Kernig or Brudzinski tests. The cases of Dupont and Andersen also yielded no proof of a specific etiology. The 6 cases which we have encountered in the past five years will be briefly reviewed and compared with those reported by Saenger and Dupont and Andersen. The accompanying tables include a fourth series reported by Bremner and Neligan in the British Medical Journal under the title “Benign Form of Acute Osteitis of the Spine in Young Children” (1). Some of the features of the previously mentioned groups of cases are compared with our series, from the University of California at Los Angeles, in Table I. As seen here, the sex incidence was equal in all series. This is in contrast to pyogenic osteomyelitis of the spine which has a higher incidence in the male (21). The age spread was increased in the current series, with 2 infants of seven months. The initial symptom complex varied among the four major syndromes; only 3 of the 14 cases reported by Saenger, Dupont and Andersen, and the authors of this paper clearly presented with back pain. The hip-leg syndrome was the most common, occurring in 6 of the 14 patients.

A new form of respiratory disease in premature infants.

Considerable attention has been focused recently on respiratory distress syndromes occurring in newborn infants, particularly in premature infants. Most of these illnesses are acute, occurring immediately or very shortly after birth and soon terminating in either death or complete recovery. Since 1956, five cases of an entirely different kind of respiratory syndrome have been seen at the Los Angeles County Hospital premature nursery. The clinical courses have all been similar, in that dyspnea and cyanosis developed gradually and cor pulmonale tended to appear. A most striking and consistent finding has been the extensive radiographic changes seen in all the infants. Exhaustive laboratory tests have failed to demonstrate specific infectious agents or systemic illnesses associated with pulmonary pathology. Clinically these cases resembled the socalled interstitial plasma-cell pneumonia, but histological examination of the lungs unequivocally differentiated the two. 3,6 Histological appearance of the lungs of two infants, however, closely resembled that seen

The Effect of Penicillin on Early Mortality and Growth in Poults

Poult mortality occurring during the first two week brooding period, in absence of specific infectious agents detectable in routine pathological examination, is commonly reported. Losses of this nature observed at the Oregon Station begin about the fourth day, reach a peak the eighth day and are generally over by the twelfth day. Sanitation precautions in hatchery and brooding management beyond those generally employed have not been found helpful in reducing this loss. With introduction of antibiotics to starting diets it was noted that mortality from the non-specific causes was reduced in many instances. Observations on poult brooding trials are reported showing the relation of penicillin to early losses at time of starting poults.Chilson and Patrick (1946) reported that withholding feed and water for 24, 48 and 72 hours after hatching resulted in 4.8, 11.5 and 29.3 percent mortality, respectively, up to 12 weeks of age. Previously Hammond (1944) ascribed .

Embryonic hearing organs after maternal rubella.

AbstractThree temporal bones of two four‐month embryos, operatively removed from mothers who suffered rubella in the second month of pregnancy, were histologically examined. Hyperemia and free hemorrhages were seen, while the nervous elements of the inner ear were found to be in a condition corresponding to the fetal age.This being the period in which the organ of Corti is differentiating along the basilar membrane, any possible disturbance in the delicate mechanism of adjustment, e.g., the lagging behind of certain sections, has to be closely watched as a possible source of hearing defects.The specific infectious agent causes arrest of development of the end‐organ in the most critical period and vascular damage, possibly the latter being the primary change. Vulnerability of the vessels shows up at the end of the pregnancy in an increased tendency for birth injuries. This way a series of factors collaborate to produce the picture of defective hearing in the progeny, after rubella of the mother.As far as a survey can be given today, there are two ways in which damage results by exposure to the virus of rubella: One being arrest of development, the other vascular changes. The two can be formulated into a monistic theory by assuming that the vessels are the first to suffer, and lack in nutrition is then followed by developmental arrest. Here is a field of research of rare interest with many problems unsolved. The first decade after the basic discovery of Gregg yielded a rich crop of investigative results, among which, however, pathological findings are negligible. Aycock said that rubella now takes on the status of a disease worthy of the best in diagnosis, treatment, prevention and research. In attacking the problem of the pathology of aural damage it is desirable that the otologist should assume the leading rǒle before the initiative is definitely lost to borderline disciplines

Rèticulosarcome Généralisé, A Point De Départ Cutané

SummaryAnatomo-clinical study of a case of reticulosarcomatosis originating in the skin of the frontal region. Gradual extension to most of the face, to several lymph-glands, the mammary gland. Death by thrombosis of both renal veins resulting from the extensive metastatic involvement of both kidneys.Discussion of the mode of metastasis in similar cases, and the possibility of extracellular transmission of a specific infective agent.

Erythema Nodosum (Nodal Fever, Dermatitis contusiformis)

A partial review of the literature dealing with erythema nodosum and an analysis of the cases observed during a 15 year period in a pediatric hospital in New York City brings to the fore the concept that erythema nodosum is an episode of hypersensitiveness which reflects an allergic response to a specific agent—usually an infection, occasionally a drug. In current American experience, the majority of cases are causally related to infection with beta-hemolytic streptococcus, tuberculosis occupying second rank, and a variety of other infectious diseases bringing up the rear. Cases related to sulfonamide therapy are on the wane, parallel with the diminishing use of sulfathiazole, but are still encountered occasionally in connection with sulfadiazine or other sulfonamide administration. The sensitivity of the skin may be demonstrated by intracutaneous injection of suspensions of killed organisms, or of some of their protein derivatives, or, in appropriate circumstances, of material containing inactivated filtrable virus. On the basis of such tests, the relation of erythema nodosum to the responsible underlying infection can usually be clearly demonstrated. Except in those cases in which the eruption results from medication, the significance to the patient of the development of erythema nodosum is the fact that it reflects the surge of the allergic response to a specific infectious agent and thus calls for adequate measures for identification of the underlying disease of which it is itself merely a surface phenomenon. The course of the underlying infection depends on other factors than the patient's high degree of sensitivity, and the outlook is not necessarily more grave because of the associated eruption; but along with the change in allergy there may occur changes in immunity which are potentially of great import. For the clinician, then, erythema nodosum should properly serve as a flash signal calling for a more probing search into the patient's total problem.

STUDIES ON THE ETIOLOGY OF SPONTANEOUS CONJUNCTIVAL FOLLICULOSIS OF MONKEYS

Spontaneous folliculosis of Macacus rhesus monkeys—a type of follicular conjunctivitis associated with marked, local, inflammatory reactions—is apparently a disease sui generis, due to a specific infectious agent. It can be transmitted from monkey to monkey by means of subconjunctival injection of suspensions, and by conjunctival swabbing of the secretions, of affected tissues, or by contact of normal animals with folliculosis monkeys. The agent causing folliculosis has failed in our hands to pass through Berkefeld and Seitz filters, even those of an unusual degree of permeability; and the lesions that it causes show no cellular inclusions suggestive of the action of a virus. The condition is due apparently to an organism of low grade pathogenicity. The essential histopathological structure corresponds to that of a folliculoma (16) which, while not identical with a granuloma, bears certain resemblances to the latter. The studies here reported concern only one species of monkey, Macacus rhesus. Further investigations will be carried out on different species of Anthropoidea and other animals.

SOME FACTORS IN THE EPIDEMIOLOGY OF POLIOMYELITIS

Notwithstanding the brilliant work of the last three years upon the experimental transmission of poliomyelitis, and the numerous painstaking epidemiologic studies of the disease, there remains, in the minds of practically all who have studied the subject, considerable doubt as to the means by which this infection is actually disseminated in nature. The explanation of this uncertainty is to be found, not in the incompleteness of the experimental work, nor altogether in the paucity of epidemiologic data, but rather in the seeming lack of harmony between experimental results and epidemiologic observations. Experimentally it has been shown that poliomyelitis is an infectious disease, due to a filterable virus, easily, almost constantly transmissible to monkeys. It has quite recently been shown that the virus which is the specific infective agent may be present in the discharges from the naso-pharynx, the trachea and the intestines of persons suffering from poliomyelitis. It has also been shown that monkeys may, though not constantly, be infected through the nasal mucous membrane, and under somewhat artificial conditions, through the mucous membrane of the gastro-intestinal tract. Lower animals other than the monkey have not been found susceptible to laboratory infection with poliomyelitis, with the exception of the rabbit, in which an atypical form of the infection may occasionally be produced. The virus of poliomyelitis has been found, in nature, only in the organs and discharges of persons suffering with or recently dead of the disease.* To this statement there is one exception, namely, the finding of the virus in the dust of a room occupied by a patient suffering with poliomyelitis. The dust was presumably contaminated with the discharges from the patient and attendants. The experiments showing the infectiousness of the discharges from patients and the possibility of infection taking place through mucous membranes not grossly injured, form a very convincing chain of evidence, if not actual proof that the disease is, in nature, transmissible directly from person to person. The doubt as to whether this is the real means of transmission in nature

A CASE OF ACUTE ENDOCARDITIS CAUSED BY MICROCOCCUS ZYMOGENES (NOV. SPEC.), WITH A DESCRIPTION OF THE MICROORGANISM

From a case of acute endocarditis of the aortic and mitral valves with infarctions m the spleen and kidneys a micrococcus was twice isolated in pure culture from the blood during life and was demonstrated after death both microscopically and in pure culture in large numbers in the valvular vegetations, the infarctions and other parts. No other species of microorganism was found. This micrococcus is very small, occurs mainly in pairs, sometimes in short chains, stains by Gram's method, grows in small, pale, grayish-white colonies on gelatine and agar, at first clouds bouillon, which then becomes clear with a whitish sediment, does not produce gas in glucose media, liquefies gelatine slowly and to some extent also blood serum, and is especially characterized by its behavior in milk, which it acidifies, coagulates and subsequently liquefies. It produces a milk-curdling ferment and also a proteolytic ferment, each of which is separable from the bacterial cells. It remains viable for months in old cultures and is tolerably resistant to the action of heat and antiseptics. The micrococcus is pathogenic for mice and rabbits, causing either abscesses or general infections. Typical acute vegetative endocarditis was experimentally produced by intravenous inoculation of the organism in a rabbit and a dog, and the cocci were demonstrated in pure culture in the vegetations and other parts of these animals after death. Although the micrococcus here described has some points of resemblance to the pneumococcus and Streptococcus pyogenes on the one hand and to the pyogenic staphylococci on the other, it is readily distinguished from each of these species by cultural features which have been described and which are so obvious that the differentiation of these species from our micrococcus need not be discussed in detail. We have searched through the records concerning microorganisms described in association with endocarditis and other diseases, as well as those isolated from water, soil and other sources, and have been unable to find a description of a micrococcus identical in all particulars with that here described. Such points as staining by Gram, liquefaction of gelatine, coagulation and peptonization of milk, served singly or in combination to distinguish our micrococcus from other forms which in some respects might resemble it. We feel justified, therefore, in recognizing this organism as a new species and from its fermentative properties propose for it the name "Micrococcus zymogenes." Micrococcus zymogenes must be added to the already considerable list of bacteria which have been found as the specific infective agents in endocarditis. That it was the cause of this affection in our case was conclusively demonstrated by its repeated isolation in pure culture from the blood during life, by its presence in pure culture and large numbers after death in the cardiac vegetations, the infarctions, and other parts of the body, and by the experimental proof of its pathogenic properties, and notably its capacity to produce vegetative endocarditis by intravenous inoculation in animals.

SCIENTIFIC RESEARCHES RELATING TO THE SPECIFIC INFECTIOUS AGENT OF SMALLPOX AND THE PRODUCTION OF ARTIFICIAL IMMUNITY FROM THIS DISEASE.

<h3>Gentlemen:</h3> —A complete review of the experimental researches which have been made with a view to demonstrating the exact nature and biologic characters of the specific infectious agent which by its multiplication in the body of a susceptible individual gives rise to the disease known to us as variola, or smallpox, would require a volume. But at the end of this volume I would be obliged to record as the principal conclusion reached, the fact that the specific infectious agent in this disease has not been demonstrated. It does not follow from this statement that the researches made have been without value. If this were so I might dismiss this portion of my subject without further remark. But the present occasion calls for something more than this; for, while we are here chiefly to celebrate the centennial of Jenner's great discovery and to consider the beneficent results which have followed