摘要:

In in vitro tissue cultures of human bone tumors (osteoclastomas, chondroblastomas) containing numerous multinucleated cells, the finding of tri-, quadri- and other types of multipolar mitosis has been studied. The presence of multipolar mitosis in the cultures and its role in the formation of multinucleated cells suggest the existence of a combined mechanism of mitosis and fusion for the formation of multinucleated cells in human bone tumors in in vitro tissue cultures.

ISSN:0030-2414    

DOI:10.1159/000224816

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

The development of resistance of animal tumour tissue in vivo toward pyrimidine and purine analogues is generally accounted for by a process of mutation and selection, although in some cases metabolic alterations leading to the emergence of resistant cells are epigenetic. Neoplastic cells may develop resistance in vitro toward a pyrimidine analogue while they carry a repressed oncogenic virus genome; upon withdrawal of the drug, the synthesis of virus particles appears. Following the administration of one analogue, resistance in various tumours develops in different patterns. The underlying biochemical lesions resulting in the emergence of resistance following 6-azauridine, 5-fluorouracil and 5-azacytidine is the deletion of uridine kinase which is the rate-limiting enzyme along the salvage pathway. There is an indication that at least in some cases the decreased activity of this enzyme is due to its structural and/or conformational changes. The development of resistance toward 5-iodo- and 5-bromo-2′-deoxyuridine is accompanied by the deletion of thymidine kinase activity; resistance towards cytosine arabinoside is associated with the deletion of deoxycytidine kinase. Different means of circumventing the emergence of resistance are surveye

ISSN:0030-2414    

DOI:10.1159/000224817

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

The orthodox teaching has long been that lymph transports cancer cells to ‘lymph nodes’, while blood transports them to extra-nodal structures called ‘organs’. This dual classification dates back to over a century ago when extra nodal tissues were called ‘conglomerate glands’, whereas lymph nodes were segregated from the rest and called ‘conglobate glands’. Today, this archaic division is no longer valid. Correctly defined, lymph nodes are organs in their own right. Definition aside, since lymph nodes are nourished through the aorta like the other structures hitherto called organs, it is erroneous to assume that blood-borne cancer cells invade these other structures and spare the lymph nodes. For the uniformities in the mechanism of metastasis to crystallize completely, the organ status of lymph nodes requi

ISSN:0030-2414    

DOI:10.1159/000224818

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Sodium warfarin was studied for its in vitro effect on nuclei acid synthesis of L1210 leukemic cells and Walker 256 carcinosarcoma cells. Moderate inhibition was noted in the incorporation of thymidine and uridine into DNA and RNA in L1210 cells, but only at very high concentrations, and no inhibition was seen in Walker tumor cells. The survival of L1210-bearing mice was not influenced by various regimens of sodium warfarin treatment. These data indicate that sodium warfarin probably has no direct in vivo antitumor activity against L1210 leukemia of mice or Walker 256 carcinosarcoma of rats.

ISSN:0030-2414    

DOI:10.1159/000224819

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

The case described is that of a patient who initially presented with bleeding tendency characterized by epistaxis, bruises, and purpura for 6 years which was subsequently diagnosed as autoimmune thrombocytopenia. The patient was found to have Hodgkin’s disease, stage III-A, after biopsy of submandibular node and laparotomy. The thrombocytopenia responded initially to steroid therapy followed by splenectomy. Treatment of Hodgkin’s disease with radiation has had no effect on the course of the autoimmune thrombocytopenia, even though the Hodgkin’s disease is in complete remission. The test for platelet factor-3 antiplatelet autoantibody was positive, while no isoantiplatelet antibody was found as a result of the complement fixation test. The thrombocytopenia is responding to Cytoxan therapy after failure of splenectomy and ste

ISSN:0030-2414    

DOI:10.1159/000224820

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Atypical endometrial hyperplasia with squamous metaplasia was misdiagnosed as adenoacanthoma in a 27-year-old unmarried woman. The urinary testosterone and 11-deoxy-17-ketosteroids (dehydroepiandrosterone, etiocholanolone and androsterone) were found markedly above normal. Retroperitoneal pneumography revealed an adrenocortical tumor on the right adrenal. Treatment with dexamethasone was followed by right adrenalectomy. After this treatment, the patient resumed a normal menstrual cycle. The endometrium examined in the premenstrual period after surgery presented a normal progestational pattern and the urinary androgenic metabolites a normal value.

ISSN:0030-2414    

DOI:10.1159/000224821

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Several investigators have shown that changes occur in isoenzyme activities of lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G-6-PD) as tissues become neoplastic [5, 7, 10]. Acrylamide-gel electrophoretic studies of two Syrian hamster tumors have demonstrated changes in the isoenzyme patterns of LDH and G-6-PD during tumor progression. A stilbestrol/testosterone-induced scent-gland tumor develops the typical LDH picture of malignant tissues (high concentration of the slowest moving isoenzyme) as it progresses to its final metastatic state [2, 3]. The G-6-PD isoenzyme pattern of a stilbestrol-induced and stilbestrol-dependent renal carcinoma differs from that of an autonomous hormone-independent variant derived from it [4]. Since the estrogen-induced tumor of the kidney of the Syrian hamster was first described [6], several hormone-independent autonomous variants and one spontaneous renal tumor have appeared in Kirkman’s hamster colony. The observations on these tumors described in this paper suggest the possibility of using (LDH) and (G-6-PD) isoenzymes analysis in distinguishing clinically between hormone-dependent and hormone-independent renal tumor

ISSN:0030-2414    

DOI:10.1159/000224822

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Use of the peripheral nucleated cell count (PNC) to assess response after single-dose or multiple-dose drug administration was demonstrated in mice showing 45,000–55,000 PNC/mm3 on day 20 after Rauscher virus inoculation. The dose-response study with single-dose administration showed that the decrease in PNC was dose-dependent and that alkylating agents were relatively more effective than antimetabolites. In the multiple-dose study, an inverse relationship was demonstrated between the levels of PNC and the increase in lifespan of the diseased mice. Mice with lower PNC levels (<55,000/mm3100 days showed a normal blood picture and the absence of infective material in their plasma. Di-2-chloro-ethylphenyl-N-(p-carboxyphenyI)carbamate, a new alkylating agent, increased the lifespan of the diseased mice significantly in both single- and multiple-dose studie

ISSN:0030-2414    

DOI:10.1159/000224823

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Chronic forced feeding of iodine in small doses accelerates mammary tumour appearance in female rats after treatment with 7,12-dimethylbenz-(a)anthracene; extended exposure to cold, which also results in acceleration of metabolism with a transient increase of thyroid function, does not influence carcinogenesis in this model in a similar way.

ISSN:0030-2414    

DOI:10.1159/000224824

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Planarians can form tumor-like outgrowths, either spontaneously, or as a result of various experimental interventions, especially the injection of substances that can be carcinogenic or indifferent. Some tumors represent abnormal excessive regenerates; the others are true neoplasms that rapidly lead to the animal’s death. Experimental factors that provoke the appearance of these neoplasms generally produce, in certain species, lethal regressions of head tissues caused by the cells’ incapacity to differentiate, a situation that is analogous to the one produced by X-rays. Injections of oil or water provoking these regressions stimulate the mitotic activity of the type I cell system, as do amputations, but only slightly increase the number of mitoses in dedifferentiated material (the syncytium). Planarians having received an injection are more resistant to X-rays; this confirms the concept that the stimulation of the type I cell system increases the production of nucleic acids. One can venture the hypothesis that in planarians cancer may be due to factors (injections and an overly rich diet) that increase the production of cells whose cytolysis frees nucleic ac

ISSN:0030-2414    

DOI:10.1159/000224825

出版商:S. Karger AG    

年代:1973

数据来源: Karger