摘要:

AbstractT‐2 toxin is an important representative of trichothecenes produced by various species of imperfect fungi, mainly Fusarium genus. It is a naturally occurring toxin that can cause severe diseases in human and animals. No definite data demonstrating the carcinogenic potential of T‐2 toxin had been reported up to now. We demonstrated that T‐2 toxin reproducibly induced chromosomal structural aberrations both in cultured human peripheral blood lymphocytes as well as in V79Chinese hamster fibroblasts. The mean percentage of cells with aberration of human lymphocytes from normal individuals induced by T‐2 toxin is 49‐fold (9.8%) of the mean percentage of corresponding control cultures without T‐2 toxin (0.2%). T‐2 toxin induced chromosome type (76%) as well as chromatid type (24%) of aberrations; among them, acentric fragment (46%) was the most common type, and chromatid gap, deletion, and chromosome gap were the next most common. T‐2 toxin can induce aberrations in cells at different phases of the cell cycle. There are definite dose‐effect relationships within a certain range of dosage of T‐2 toxin in experiments with both human peripheral blood lymphocytes and V79cells. T‐2 toxin exhibited three types of effects on cells, namely, mitogenic at lowest concentration, clastogenic (chromosome aberration) at median concentration, and cytotoxic at higher concentration. The dose‐effect curves of these three effects are partly overlapping. There is some interindividual difference in sensitivity of response for the clastogenic effect of T‐2 toxin, but no resistant individual was observed. Sex or age effect was not observed. The above results suggest that T‐2 toxin has carcinogenic potentials. The dosage of aflatoxin that can induce chromosomal aberration of human peripheral blood lymphocytes is thousands‐fold of the dosage of T‐2 toxin as shown in this report. T‐2 toxin might have more hazardous potentials than had been previously considered. The carcinogenic potential of T‐2 toxin and related trichothecenes and their possible roles in carcinogenesis of upper gastrointestinal (G.I.) tract canc

ISSN:0021-9541    

DOI:10.1002/jcp.1041290413

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

ISSN:0021-9541    

DOI:10.1002/jcp.1041290414

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractHepatitis B virus (HBV) had been considered as the main causative factor of primary hepatocellular carcinoma and universal immunization of newborns was recommended as the major approach to control hepatitis and hepatoma in areas of prevalence. As the initial phase of the first vaccination program for such a purpose, a pilot study was done from September 1983 to May 1984 in a high incidence rural area of China. In an area of 214,343 inhabitants, 1,703 newborns (99% of all births) were vaccinated. Ninety‐seven percent of all vaccinees were followed up at 1 year. The vaccine used was Hep‐B Vax, given intramuscularly at 0, 1, and 6 months after birth. Four immunization regimes were used: 5‐μg or 2,5‐μg doses with or without hepatitis B immune globulin (HBIG) added in the case of carriers children. These groups were defined by drawing lots at community level. A matched control was selected on a voluntary basis. Each group consisted of 400 infants. Vaccination was proven to be very safe and well accepted by the public. The prevalence of HBV infection in the area was further demonstrated by the high HBsAg‐positive rate measured: 14.2% of the 1,180 mothers (3.9% were also e‐antigen positive), 7.6% and 10.1% of the unvaccinated children at 6.5 months and 1 year of age, respectively. It was shown that vaccination with a 5‐μg or 2.5‐μg dose significantly lowered the HBsAg positives to a level close to 1.5% versus 10% in the control group at 1 year. An 85% protection was thus achieved. A 5‐μg dose plus HBIG did not show additional benefit. A 2.5‐μg dose plus HBIG gave less protection, and anti‐HB levels were also significantly lower than in other groups. Among the 12 failures found in the 5‐μg and 2.5‐μg groups, 11 were born to HBsAg‐positive mothers, nine of whom also had e‐antigen. Available data showed that 29% of children born by e‐antigen‐positive and 2.7% of children born by e‐antigen‐negative carriers had the risk of becoming carriers during the first year of life following vaccination. The present study demonstrated the feasibility and rationale of conducting universal immunization of newborns in endemic rural area for controlling hepatitis and hepatoma. The significance of the possible use of the vac

ISSN:0021-9541    

DOI:10.1002/jcp.1041290415

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractBiotherapy represents a new modality of cancer treatment. It utilizes biologicals and biological response modifiers in the treatment of cancer. Many of these substances are of “natural” origin emanating from mammalian cells as physiologic mediators of immune response and as substances active in the regulation of growth and maturation. With the advent of molecular biological techniques, hybridoma technology, and computer applications, it is now possible to prepare these biological substances in highly purified form and in large quantities for use as medicinals. The expertise required to apply these biotherapeutic approaches to the treatment of cancer often involves the use of immunological and/or molecular biological capabilities. Because of the rather specialized expertise needed to understand and apply these substances as anticancer approaches, those individuals with expertise in the application of chemotherapy to patients with cancer are not necessarily well prepared for the translation of biotherapy to the clinic. Biotherapeutic approaches are broad and involve a whole range of physiological responses inherent in cancer biology. The approaches necessary to bring these biotherapeutic capabilities to the clinic need to be considered carefully, and the use of new techniques and new methods of application should be encouraged so as not to inhibit these potentially powerful anticancer approaches. As natural mediators, many biologicals have much less inherent toxicity than the drugs previously used in systemic cancer therapy. Therefore, the systems for translating these substances from the laboratory to the clinic should be restructured for the rapid translation of biotherapy to the pati

ISSN:0021-9541    

DOI:10.1002/jcp.1041290416

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

ISSN:0021-9541    

DOI:10.1002/jcp.1041290402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY