THE RELATION BETWEEN BODY AND ORGAN WEIGHTS IN THE RABBIT

Data from 645 normal rabbits were used as the basis of an investigation of the relation existing between body and organ weights. Actual and relative weights were correlated with both gross and net body weight. The results obtained varied with different classes of organs but it was found that, in general, there was an agreement between the form and degree of the correlation shown and the structural and functional properties of the organs concerned.     

STUDIES BASED ON A MALIGNANT TUMOR OF THE RABBIT : VI. VARIATIONS IN GROWTH AND MALIGNANCY OF TRANSPLANTED TUMORS. PART 1. RESUTLTS OF TRANSPLANTATION FOR THE FIRST TWENTY GENERATIONS.

A report is given of the results obtained by intratesticular inoculation of a malignant tumor of the rabbit based on a study of the first twenty generations. The subject is presented from the standpoint of variations in growth and malignancy as they occurred with continued transplantation. Essential features of the experimental conditions and of clinical and postmortem observations are condensed and recorded graphically. On analyzing the results of these experiments, it was found that many changes had occurred in the behavior of the tumor during transplantation, but that the changes were of a very irregular character and as a rule did not proceed constantly in any given direction. Moreover, the evidence as to the effect of transplantation on the growth and malignancy of the tumor was contradictory in that there was a great deal of evidence to show that there had been a decided increase in the activity and capacity for growth on the part of the tumor cells. But, with the exception of a few generations, there was an apparent reduction in the incidence and percentage distribution of secondary tumors, while the death rate was unaltered or actually diminished. It was believed that this paradoxical situation afforded a basis for an explanation of the results that had been obtained by transplantation.     

PENETRATION OF NORMAL MUCOUS MEMBRANES OF THE RABBIT BY TREPONEMA PALLIDUM AND THE INFLUENCE OF THIS MODE OF INFECTION UPON THE COURSE OF THE DISEASE

Experiments were carried out with three strains of Treponema pallidum to determine whether infection could be produced by applying an emulsion, rich in spirochetes, to normal mucous membranes of rabbits and whether an infection produced in this manner differed in any respect from one produced by other methods of inoculation. It was found that a simple instillation of a spirochete emulsion into the conjunctival sac or the sheath was all that was necessary to obtain an infection. Still, the infection produced in this manner differed from that produced by intracutaneous or testicular inoculations in that it tended to pursue a mild or asymptomatic course and frequently without the development of a characteristic chancre. It is pointed out that these experiments may have a bearing on problems pertaining to obscure and atypical cases of human syphilis as well as the more immediate question of the infectivity of Treponema pallidum.     

STUDIES BASED ON A MALIGNANT TUMOR OF THE RABBIT : I. THE SPONTANEOUS TUMOR AND ASSOCIATED ABNORMALITIES.

A malignant tumor which developed at the site of a primary syphilitic lesion in the scrotum of a rabbit, about 4 years after inoculation, and eventually led to the death of the animal, has formed the basis for an extensive series of investigations beginning with the study of the spontaneous tumor. The present report contains the clinical history of the animal from the time of inoculation to its death and the results of pathological examinations. The most important events recorded may be summarized as follows: 1. A mild but persistent syphilitic infection with an occasional relapse and the eventual development of chronic inflammatory lesions in the skin associated with atypical epithelial proliferations. 2. The occurrence, at about the same time, of extensive degenerative changes in the dermis accompanied by an atypical growth of hair follicles, with the production of diffuse and nodular areas of thickening and induration (scleroderma). 3. The development of a growth in the skin of the left scrotum which recurred after removal and spread diffusely over adjacent parts of the skin, and metastasized to the regional lymph nodes and to internal organs. 4. The transplantation of the growth to other rabbits by intratesticular inoculation and the successful propagation of the growth over a period of nearly 2 years (twenty generations). 5. The development of a cachexia and of pressure phenomena from metastases involving the cervical and lumbar regions of the spinal column which eventually led to the death of the animal. 6. The discovery, post mortem, of an extensive leucoplakia of the tongue and buccal mucosa, chronic inflammatory lesions in the esophagus with atypical epithelial proliferation, and a nodular growth in the left testicle differing in character from that in the scrotum. 7. The presence of extensive degenerative changes in the vascular system, degeneration of the parenchymatous organs, atrophy of the thymus and lymphoid system, with chronic lymphadenitis, atrophy, degeneration, and necrosis of the suprarenals, and atrophy and hyperplasia of the thyroid with chronic thyroiditis. The conclusion was reached that the growth in the scrotum represented a neoplasm of epithelial origin which was composed of cells allied to those found in the bulb and root sheath of the hair. No explanation was offered for the origin or unusual malignancy displayed by the tumor pending the introduction of experimental data. It was stated, however, that the evidence presented was sufficient to warrant the assumption that the factor of foremost importance in the development of the tumor was constitutional rather than local.     

A STUDY OF BACILLUS PYOGENES

Bacillus pyogenes is probably quite common in this country, as it is known to be in Europe. A careful study of twelve strains from cattle and one from a hog has disclosed the following characteristics which have not been reported or have been in dispute. Bacillus pyogenes is Gram-positive and pleomorphic, producing forms ranging from short chains of streptococcoid elements to branching filaments. It is hemolytic, producing the beta type of hemolysis in blood agar. It is not hemoglobinophilic, though its growth is greatly favored by some higher protein material such as egg albumin, serum, or blood. It ferments xylose in addition to the substances previously reported. The coagulation of milk by Bacillus pyogenes is primarily an enzyme coagulation and the subsequent digestion of the curd takes place in an acid medium. The intravenous injection of rabbits was invariably fatal. The lesions most commonly developed were those of the bones. Paralysis was frequently produced, and in each case was caused by lesions in the vertebrae exerting pressure against the ventral columns of the spinal cord. Muscle abscesses were also frequently produced. The authors regard the organism as belonging to the Corynebacteria rather than to the influenza group.     

EXPERIMENTAL SYPHILIS IN THE RABBIT : VI. AFFECTIONS OF BONE,CARTILAGE, TENDONS,AND SYNOVIAL MEMBRANES. PART 1. LESIONS OF THE SKELETAL SYSTEM.

From a study of a series of rabbits inoculated with two old strains of Treponema pallidum, it was found that localized infection of bones and tendons was of frequent occurrence and led to the formation of a variety of lesions. The bones usually involved were those of the face and the feet and legs. Most often the lesions arose from the periosteum but developed also within the bone or marrow cavities and at lines of epiphyseal union. Grossly, the periosteal lesions were of two types—one being a circumscribed, indurated, and nodular mass and the other a process of a more diffuse character. Histologically, the lesions presented the typical appearance of syphilitic granulomata composed of more or less distinct layers which corresponded roughly with structural divisions of the periosteum. The composition of lesions of membrane and of cartilage bones differed somewhat in this respect, especially in the development of an osteoclastic layer. Invasion of the bone with absorption and necrosis were constant features of periosteal affections and were most marked in the case of the facial bones and the small bones of the feet. Lesions in the bone and marrow cavities were detected chiefly by radiographs or by the occurrence of bone destruction in the absence of periosteal involvement. They were characterized by a loss of structural detail in the bone, rarefication, increased fragility, necrosis, pathological fracture, and epiphyseal separation associated with more or less granulomatous reaction. Histologically, the bone lesions presented essentially the same picture as those of the periosteum, while the lesions which arose from the marrow cavities were composed chiefly of polyblastic infiltrations. In this group of affections, the most important were those which developed at the epiphyses. The destructive effects produced by all classes of lesions varied from a slight surface erosion or rarefication to extensive necrosis resulting in the formation of bony defects or in disintegration or fracture of the bone. These conditions differed very decidedly with the particular bones involved. Of especial importance in this connection was the occurrence of a peculiar form of mass necrosis which at times resulted in the destruction of considerable areas of bone even in parts where the granulomatous type of lesion was comparatively slight. The most characteristic injuries were the saddle-nose deformities and the epiphyseal separation in the small bones of the tarsus and hind feet. The marks of permanent injury were, on the whole, comparatively slight, but they also differed both with the degree of the original injury and with the bone affected. Granulomatous lesions of tendons or tendon sheaths were occasionally seen, and in a few instances, lesions of synovial cavities were demonstrated microscopically.     

A bibliometric analysis of occupational therapy publications

Background: Bibliometrics involves the statistical analysis of the publications in a specific discipline or subject area. A bibliometric analysis of the occupational therapy refereed literature is needed.

Aim: A bibliometric analysis was completed of the occupational therapy literature from 1991-2014, indexed in the Science Citation Index-Expanded or the Social Sciences Citation Index.

Method: Publications were searched by title, abstract, keywords, and KeyWords Plus. Total number of article citations, citations per journal, and contributions per country, individual authors, and institution were calculated.

Results: 5,315 occupational therapy articles were published in 821 journals. It appears that there is a citation window of an approximate 10-year period between the time of publication and the peak number of citations an article receives. The top three most highly cited articles were published in Developmental Medicine and Child Neurology, JAMA, and Lancet. AJOT, BJOT and AOTJ published the largest number of occupational therapy articles with the United States, Australia, and Canada producing the highest number of publications. McMaster University, the University of Queensland, and the University of Toronto were the institutions that published the largest number of occupational therapy journal articles.

Conclusion: The occupational therapy literature is growing and the frequency of article citation is increasing.