Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0596263 (carcinogenesis)
 64,820 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

(1) Passive hemagglutination and radioimmunoassay are suitable methods for the detection of AFP in the low concentration range. (2) In 3.72% of the cases a clinically unknown carcinoma was found in an unselected group of patients with liver cirrhosis. (3) 21.9% of the patients showed AFP elevations up to 2000 ng/ml. In 10.6% of this group, increasing titers demonstrated a primary liver cell carcinoma. In 89.4% a transitory rise of AFP was not associated with tumor growth. Levels return to normal values within three months in 90% of the cases. (4) Transitory AFP elevations are not correlated to clinical conditions (praecoma, coma, delirium, bleeding, ascites, shunt) or to biochemical parameters (GOT, GPT, bilirubin, prothrombin complex time, gamma-globulin). (5) A temporary rise in AFP is more frequently observed in groups with high hepatoma incidence than in groups with low hepatoma incidence. (6) Therefore, it may be suggested that a transitory rise of AFP could reflect a "primary reaction" of carcinogenesis. (7) Primary liver cell carcinoma is found to be more frequent in posthepatitic than in postalcoholic, cryptogenic, and other cirrhosis and to be more frequent in australia-antigen positive than in australia-antigen negative cases. (8) Routine serological tumor antigen screening of patients with a precancerous disease is useful.
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PMID:Early detection of hepatoma: prospective study in liver cirrhosis using passive hemagglutination and the radioimmunoassay. 5 21

The central theme of this communication is the interaction of herpes simplex virus type 2 with its host. In addition to the productive infection, we are confronted by latency and, as suggested by recent studies, by cancer. The possible mechanisms of latency and the role it may play as a precursor of carcinogenesis are discussed. If virus is to coexist with its host, a defined level of molecular interaction between host and viral gene products must exist. The association of AG-4 with active tumor growth and its identification as a minor virion protein, also exposed on the surface of the infected cell, open new vistas in the understanding of the role virus-host cell interactions may play in tumor growth. The modulation of the host immune response by the results of this interaction may play a significant role in cancer control. In these terms, the observation that antibody to AG-4 is a macroglobulin and that, therefore, immunity to AG-4 may be T-cell independent, should be given further consideration.
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PMID:Herpesvirus type 2-related antigens and their relevance to humoral and cell-mediated immunity in patients with cervical cancer. 17 45

During carcinogenesis, induced by diethylnitrosamine in rats Wistar (in doses of 2.5 mg per Kg of weight daily with drinking water), the hexokinase (HK) activity in blood serum was observed with the appearance of the first morphological symptoms of tumor growth. It is observed mainly starting from the first months. At the end of the experimental period (8-9th month), when hepatomas develop in the liver, the HK activity in blood serum was noted almost in all cases. No serum HK activity was found in control rats.
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PMID:[Hexokinase activity in blood serum during carcinogenesis]. 19 94

The relationship of aging to carcinogenesis was immunologically examined in the hamster-bovine adenovirus type 3 system. The age of animals at the time of virus inoculation influenced the tumor growth and latency period, but not the tumor incidence. The immunological competence of hamsters to sheep red blood cells became matured around 4 weeks after birth and was not affected by the infection of bovine adenovirus type 3 (BAV-3). The strength of transplant immunity was dependent on the age of animals at the time of immunization. The growth of progressive type of tumors induced by inoculation with BAV-3 into younger animals was inhibited by the repeated inoculation of excess dose of BAV-3, administration of BCG and transfer of sensitized lymphocytes during the tumor latency. The growth of non-progressive type of tumors induced by inoculation with BAV-3 into adult hamsters was accelerated by administration of antithymocyte serum or thymectomy. The tolerance to tumor specific transplantation antigens did not play a critical role in the present system. The blocking activity to sensitized lymphocytes was demonstrated in the sera taken from hamsters developing a progressive type of tumor even in the early period of carcinogenesis.
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PMID:The relationship between age-dependent immunological competence of host and tumor growth in the hamster-bovine adenovirus type 3 system. 33 64

A number of animal carcinogenesis experiments have demonstrated that the time from initial exposure to first detection of tumors increases with decreasing dose. This observation has led to some speculation that at very low doses tumors would take so long to develop that life would end before tumors appeared. We show that the apparent increase in tumor development time can be easily seen as nothing more than a manifestation of the mathematical fact that decreasing the incidence necessarily increases the first time-to-tumor. No physical increase in tumor growth time need be postulated to explain the observations. Existing methods of low-dose risk extrapolation implicitly account for the increase in time-to-tumor statistics insofar as they account for the decrease in tumor incidence.
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PMID:The effect of dose on cancer latency period. 55 34

Recent concepts may provide the basis for new insights into the etiology and prognosis of bladder cancer. Experimental observations related to the physiology, carcinogenesis and tumor growth of the bladder epithelium are providing useful information to the urologist and may soon extend our understanding of the characteristics of this disease. This article provides an overview of some of these theoretical and experimental considerations.
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PMID:Current concepts in the study of bladder cancer. 64 31

Consideration is made of the problems involved in determining the effects of a chronic disease process, such as stomach cancer, on the observed mortality of the U.S. population. Specifically, since the time of initiation of tumor growth is unknown and the tumor becomes clinically manifest only after reaching considerable size, the early rate and pattern of tumor growth is unobserved. As a possible solution to the analysis of such problems, it is proposed to use stochastic compartment modelling techniques which deal with the problems of estimating the transition probabilities of a partially observed stochastic process. Implementation of the stochastic compartment techniques in this case depends on the selection of certain mathematical expressions from theories of carcinogenesis, epidemiologic studies and animal studies which allow the calculation of transition probabilities to unobserved states by making them explicit functions of time or age. Though the selection of the specific functions might be subject to debate, the general strategy of explicitly selecting such functions, and thereby exposing them for review in terms of biologic reasonableness and consistency with the data, seems to be a valid and useful methodology. Furthermore, various ways of viewing the model results (say from its internal behavior, e.g., from implied distributions of waiting times in various disease states) yield different insights into the various factors in carcinogenesis. The model, with parameters representing tumor incidence, time to tumor death given onset, genetic susceptibility to tumor growth and the effects of competing forces of mortality, is fitted to data on deaths due to stomach cancer for male U.S. residents age 25 and over in 1969. Two basic forms of the model, one with a waiting time distribution for occupants of the latent state and another with a single latency time, achieved excellent fits to the data. Examination of parameter estimates and compartment waiting time distributions are consistent with theoretical expectations and intuition. It is concluded that such strategies, involving the integration of clinical, experimental and vital statistics data into a comprehensive model of population carcinogenesis, are potentially powerful tools for investigation of the temporal dimensions of disease development in a human population.
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PMID:Compartment model approach to the estimation of tumor incidence and growth: investigation of a model of cancer latency. 71 21

Some parallels and differences are considered between the nutritional circumstances that favor carcinogenesis and those that favor tumor growth and host cachexia. From evidence on deletion of physiological feeding controls and changes in feeding behavior during tumor growth and from evidence on differences in sets of available feeding controls and in feeding behavior among normal individuals, it is suggested that acquisition of possibly carcinogenic dietary habits may originate, in part, from innate deficits in physiological feeding controls.
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PMID:Origins of nutritional imbalance in cancer. 105 3

Tumors in rats of the Nb strain, arising either spontaneously or after prolonged treatment with s.c. pellets of estrogen, were transplanted to establish whether hormone conditioning was required for their growth. Whereas all spontaneous tumors arising in males and many of those in females were autonomous on transplant, most of those arising in estrogenized rats continued to require hormones for growth after transplantation. The latter included carcinomas of the adrenal cortex, breast, pituitary ectopic tissue, ovary (thecomas), Leydig cells of testis, thymus, pancreas,salivary glands, oribital gland (fibroadenoma), liposarcoma, and lymphoma. Many of the tissues of origin of the tumors have not been considered to be under theinfluence of estrogens. A type of hormone-responsive tumor that was inhibited by estrogen and that grew only in normal rats is described. Ali estrogens tested, including estriol , were interchangeable in action. The incidence of the more common tumors of the adrenal, breast, and pituitary was very low in normal rats, but higher in females. All tumors were more common after estrogenization in both sexes, particularyly in older animals. The secretion of steroids and pitiutary hormones by many tumors led to obvious biological effects. Pituitary secretion led to severe lesions frequently associated with diseases in humans, but the signs of such diseases in the rat apparently were hormone dependent and disappeared if the tumor was removed. The overall results raised the possiblity that estrogens were not carcinogenic per se but stimulated the growth of previously altered cells and that, following their transplantation, this hormone requirement was retained. Irrespective of the mechanism of carcinogenesis, hormone-dependent tumor growth was not irreversible but was controlled in an unexpectedly wide spectrum of organs by exogenous estrogen. Host factors may play a major role in controlling the growth of many tumors and the ultimate course of the disease.
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PMID:Spontaneous and estrogen-produced tumors in Nb rats and their behavior after transplantation. 116 9

Prostate cancer is a major health problem for the aging male population. Despite hormonal dependence, the inevitable emergence of androgen insensitive tumors, which have a dismal prognosis, highlights the need to develop prevention strategies such as chemoprevention. An acceptable agent must interfere with either the process of carcinogenesis or tumor growth, and have minimal toxicity. In clinical studies, 5 alpha-reductase inhibitors have been shown to suppress serum and intraprostatic levels of dihydrotestosterone, an important promoter of prostate cancer, leading to reduction in prostate size and suppression of glandular cell activity as measured by prostate specific antigen secretion. In addition, 5 alpha-reductase inhibitors have demonstrated an excellent safety profile and tolerability in 12 month controlled clinical trials. No significant metabolic effects have been observed in gonadotropin secretion, spermatogenesis, serum lipids or glucose tolerance. The efficacy and safety of 5 alpha-reductase inhibitors in studies to date, combined with the androgen dependence of tumor production, strongly supports investigating their use for chemoprevention of prostate cancer.
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PMID:Chemoprevention strategies for prostate cancer: the role of 5 alpha-reductase inhibitors. 128 94


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