A case of left atrial myxoma accompanied by pancytopenia and pathological findings suggestive of pulmonary hypertension

A case of left atrial myxoma accompanied by peculiar symptoms is reported. A 15-year old boy had progressive congestive heart failure and three episodes of acute attacks of panctyopenia. The anemia was accompanied by helmet-shaped, broken red blood cells, erythroid hyperplasia and elevation of indirect bilirubin. The thrombocytopenia gave rise to hemorrhagic tendency of the skin and mucous membrane. The leukocytopenia was seen at the same time. The patient also had general constitutional disturbances showing generalized malaise, persistent fever, elevation of erythrocyte sedimentation rate, positive C-reactive protein, pulmonary infection and anginal attacks. Postmortem examinations revealed a left atrial myxoma and intricated pulmonary changes. There was obliterative endarteritis of the left coronary branch and pulmonary arteries. The interstitial pulmonary fibrosis was also prominent. The pancytopenia should have been induced by the mechanical damage of circulating blood cells by the left atrial myxoma. The pathological findings of the lungs were highly suggestive of pulmonary hypertension, which was assumed to be due to mitral block caused by the atrial myxoma.</p

Relationship between immune reactivity and developement of thymic lymphoma by N,N'-dimethylnitrosourea in C3Hf-Bi mice

By subcutaneous inoculation of N, N'-dimethylnitrosourea to adult male C3Hf/Bi mice once a week for 10 consecutive weeks the authors studied the correlation between immunological functions and histological changes in lymphatic tissues at the latent period of thymic lymphoma whose development is known to occur in 100 per cent. As a result, it was found that PFC of the spleen to sheep erythrocytes decreased to about one third the normal level by two weeks, and to one tenth by 8 weeks after initial inoculation of this compound. Hemolysin and hemagglutinin titers of the serum became less than 1 : 2 after 6 weeks and later. As for histological changes in the thymus, disappearance of lymphocytes became marked by 2 weeks, and there appeared tumor cells by 8 weeks. Also the peripheral lymphocytes as well as the total spleen cells decreased in number along with increase of the frequency of inoculation of N,N'-dimethylnitrosourea. These results seem to suggest that the immunosuppressive effect of carcinogen facilitates the development and proliferation of tumor cells possessing tumor specific antigenicity in the course of N, N'-dimethylnitrosourea- carcinogenesis.</p

Brain tumors induced in rats by human adenovirus type 12

Oncogenesis of human adenovirus type 12 in the brain of rats was examined. Newborn rats of Sprague-Dawley and Donryu&#12288;strains were injected intracranially with human adenovirus type 12.&#12288;The incidence of intracranial tumors was 91% (30/33) in SpragueDawley&#12288;and 56% (14/25) in Donryu rats. Except for one tumor nodule&#12288;located in the parietal cortex of a Sprague.Dawley rat, all tumors&#12288;developed in the paraventricular areas or in the meninges. Tumors were quite similar histologically to those induced in hamsters and&#12288;mice resembling the undifferentiated human brain tumors such as medulloblastoma,&#12288;ependymoblastoma and embryonic gliomas. From&#12288;the histological features and primary sites of tumor development, it is&#12288;suggested that the tumors in the brain of rats induced by adenovirus type 12 originate from the embryonic cells in the&#12288;paraventricular area&#12288;and also from the undifferentiated supporting cells of the peripheral&#12288;nerves in the&#12288;leptomeninges.</p

A case of histoplasmosis Report 1. Cinical, mycological and pathological observations

In our country it has been believed that there is no histoplasmosis here in Japan. However, from the above clinical signs, radiological characteristics, laboratory tests, pathological and mycological examinations, and experimental findings, we believe this is the first case of histoplasmosis in Japan.</p

Effect of oncogenic nitrosourea on intraocular tumor induction by adenovirus in rats.

Interference of oncogenic N-nitrosourea in intraocular tumor induction by human adenovirus type 12 in rats was examined. Transplacental administration of methylnitrosourea to rat embryo reduced significantly the latent period of the intraocular adenovirus tumor in each animal whereas in groups preadministered with ethylnitrosourea the decrease in the latent period showed marked individual variation. Preadministration of N-nitrosourea caused little change in the morphology and incidence of adenovirus tumors. The histological picture of adenovirus induced intraocular tumors which developed in each group of rats was that of retinoblastoma-like tumor identical to the tumor induced by single virus injection.</p

Brain tumors in hamsters induced by murine sarcoma virus (Moloney).

&lt;p&gt;Murine sarcoma virus, CS-Moloney substrain, was inoculated intracranially into 2 litters of newborn Syrian hamsters within 24 h of birth. Seven of 12 hamsters which survived more than 30 days developed brain tumors in the cerebral cortex 104 to 153 days, 139 days on the average, after the virus inoculation. The tumors consisted of spindle-shaped, round or polygonal astrocytes which showed a positive reaction for glial fibrillary acidic protein by the immunoperoxidase method.&lt;/p&gt;</p

Pseudomyxoma peritonei of ovarian origin--an autopsy case.

The autopsy case of an 80-year-old female with pseudomyxoma peritonei arising in the left ovary is reported. The patient was admitted with complaints of anorexia, sense of fullness and abdominal distension of two months' duration, and died of intestinal obstruction four months later. The autopsy revealed extensive tumor dissemination over the entire peritoneal cavity without any visceral invasion or distant metastasis. A part of the sigmoid colon showed marked stenosis and perforation with abscess formation. Histologically, the tumor was composed of various sized multiple cysts which were completely or incompletely lined by a layer of mucin-producing columnar epithelial cells with moderate nuclear hyperchromatism, and of a papillary pattern in some parts, indicating low grade malignancy.</p

Immunohistochemical demonstration of lysozyme in normal, reactive and neoplastic cells of the mononuclear phagocyte system.

Using the peroxidase antiperoxidase (PAP) method, lysozyme (LZM) was shown to exist in normal, reactive and neoplastic cells belonging to the mononuclear phagocyte system (MPS), but was not detected in histiocytosis X cells. Immunostaining for cytoplasmic LZM by the PAP method is useful for identification of mononuclear phagocytes and for diagnosis of the diseases in which these cells participate.</p

An immunofluorescent study on anti-synovial tissue antibody in the body fluid from patients with rheumatoid arthritis

There is as yet no plausible and convincing explanation for the etiology of rheumatoid arthritis. The authors investigated anti-synovial tissue antibody in the body fluid of rheumatoid arthritis by means of indirect immunofluorescent technic using non-affected synovial tissues as antigen. As the result the anti-synovial tissue antibody was detected in 7 cases of the 15 synovial fluid samples of rheumatoid arthritis and in two out of the six serum samples. The site of the localization of this antibody was demonstrated to be in the synovial membrane, especially in synovial cells and in the small blood vessel walls situated immediately adjacent to the synovial surface, but it was found in no connective tissues other than synovial membrane. It seems that this anti-synovial tissue antibody should be considered as an independent factor from rheumatoid factor, and that rather than the rheumatoid factor it is more actively associated with the localization and progression of chronic inflammation within the rheumatoid arthritis joint.</p