Biomedical subjects
P Ebbesen
Publications and source records attributed to P Ebbesen.
Complement-fixing antibody to Epstein-Barr virus soluble antigen in populations at high and low risk for nasopharyngeal carcinoma.
Greenland Eskimos comprise an ethnic group with one of the highest recorded incidence rates for nasopharyngeal carcinoma in the world. Sera from 625 Eskimos and 73 Danes (Caucasians) living in Greenland, as well as from 62 Danes living in Denmark, were tested for complement-fixing antibody to Epstein-Barr virus (EBV) soluble antigen and, from this study group, 129 donors were matched by age and sex for a study comparing antibody to viral capsid antigen, early antigen, and soluble antigen. Both Eskimos and Danes living in Greenland had significantly higher titers of EBV antibodies than Danes living in Denmark, suggesting that environment was more important than genetics or socio-economic factors in determining the antibody response to EBV. Age and sex were also factors, higher titers occurring in females and young Eskimos.
[The immune suppression syndrome in homosexual men. An epidemiological study from the Cancer Research Institute in Arhus].
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Dying old mice: occurrence of non-viable lymphocytes and autoagressive cells.
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Influences of age and anatomical site on ultraviolet carcinogenesis in BALB/c mice.
Young adult BALB/c mice were mor susceptible to the induction of skin tumors from FS40 sunlamps than were 18-month-old animals. The relative contributions of tissue and host factors to this difference in susceptibility to carcinogenesis were analyzed by reciprocal grafting of skin between young and old animals, followed by repeated exposure of the grafts to UV radiation. More tumors developed in ear skin grafted to the middorsum of young recipients than in that of old recipients, regardless of the age of the skin donor. These ear skin grafts were more susceptible to tumor induction than were comparable grafts of back skin. When large areas of dorsal skin (16 cm2) were grafted to young adult mice, very old skin (greater than 2 yr) was more susceptible to tumor induction than skin that was 1 year old at the start of irradiation.
[Infectious mononucleosis in Greenland. Assessment on the basis of statistical notifications and a 10 year hospital material].
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Stimulatory effect on DNA synthesis of thymus and spleen extract from leukemic AKR mice.
A 30,000-50,000 molecular weight (MW) extract of thymus and spleen from 11 age groups of untreated AKR mice, 1-210 days old, was tested for in vitro effect on thymidine incorporation into normal AKR lymph node cells, normal spleen cells, and leukemic thymocytes. Extracts from mice up to 5 months of age mostly had slightly inhibitory effect but concomitant with emergence of thymus leukemia in the 6-month-old mice, the extract acquired a strongly mitogenic effect on normal lymph node cells. Seven-month-old, non-leukemic animals again yielded extracts with inhibitory effect.
Inhibitory effect of a revertant cell on in vivo growth of its parental transformed cell line.
A revertant cell line, KSR-4111, cloned from a sarcoma virus transformed non-virus producing murine 3T3 cell line, K-BALB-23, was found to inhibit in vivo growth in newborn syngeneic mice of the transformed cells when grafted to the same locus, but not when grafted separately from the grafted tumor cells. No inhibition of outgrowth of the transformed K-BALB-23 cells was obtained with another revertant, KSR-12121, also cloned from the transformed K-BALB-23 cell, nor with the normal 3T3 cell. Furthermore, grafting of two syngeneic mammary tumors was unaffected by the presence of the protective revertant cells. The protective revertant KSR-4111 was furthermore characterized by inducing cytoxic non-theta-antigen-bearing spleen lymphocytes in grafted syngeneic recipients.
In vitro susceptibilities of normal human skin fibroblasts to oncoviruses, and the decreased susceptibility to HSV of fibroblasts from untreated Hodgkin's patients.
Fibroblast cultures established from the skin of 56 healthy controls and 15 untreated Stages I and II Hodgkin's patients (HD) were studied in their 3rd, 4th and 5th in vitro passage with respect to transformation with Simian sarcoma virus (SSV) and SV40 and with respect to replication of herpes simplex virus (HSV) Types 1 and 2, pox virus and interferon release. Susceptibility to the 5 viruses varied independently, except for an inverse correlation between susceptibility to SSV and HSV. HD cultures showed a depressed replication of both types of HSV. There was a borderline (P = 0.02) correlation between magnitude of HSV replication and presence of HL-A type B-w44, but this does not explain the HD control difference. Furthermore, the level of serum antibodies to HSV common antigen was not related to magnitude of in vitro replication. The results thus speak against generally enhanced cellular susceptibility to HSV as a reason for the high titres of serum antibodies to HSV in HD patients.
Enhanced lymphoma incidence in BALB/c mice after ultraviolet light treatment.
Following UV irradiation of BALB/c mice three times a week for 9 months, lymphatic leukemia or reticulosarcoma developed in 44 (12%) of 378 mice whose backs were shaved and whose ears were intact. Only 11 (5%) of 224 UV-irradiated mice whose backs were shaved and whose ears were removed developed lymphomas. Among 311 unirradiated mice whose backs were shaved, 9 lymphomas (3%) occurred. The diagnosis of leukemia or reticulosarcoma was confirmed by microscopy and transplantation. Among irradiated mice, ear tumors developed in 24% of the mice with intact ear, whereas skin tumors developed on the shaved backs in 4% of the mice whose ears were removed and also in 4% of the mice with intact ears.
Mouse skin beta-irradiated 3 months earlier shows increased content of a 30-50,000 MW mitotic inhibitor and decreased susceptibility to an exogenous inhibitor.
A 30,000-50,000 MW extract of mouse skin beta-irradiated 3 months previously with 3,000 rads, exerted a stronger in vivo inhibitory effect on mitoses in the basal layer of normal skin than a similar extract from unirradiated skin. Furthermore, epidermis beta-irradiated 3 months previously showed a reduced mitotic rate and a decreased susceptibility to inhibition by the 30-50,000 MW extract. The pathogenesis of the long term effect of irradiation might include interference with the functioning of a local mitotic inhibitor.
Epidermal carcinogenesis in young and aging animals.
1) There is an enhanced susceptibility to carcinogen in senescent mouse skin which we believe should cause deliberations about safety regulations for humans; 2) both accumulation of variant cell and/or change in a local mitosis regulatory system should serve as working hypothesis for further studies.
Change in activity of fibroblast mitotic inhibitor from mouse embryo cells aging in vitro and undergoing spontaneous transformation.
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Increased susceptibility to beta-irradiation of senescent mouse skin irrespective of grafting to young recipients.
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Experimental studies of premature ageing.
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Elevated titer of antibodies to Simian sarcoma virus envelope antigen (gp70) and normal response to influenza virus in untreated Danish Hodgkin's patients.
Untreated Danish Hodgkin's disease (HD) patients and paired age- and sex-matched controls were tested for serum antibodies to Epstein-Barr virus (EBV), six strains of influenza virus and Simian sarcoma virus/Simian sarcoma-associated virus [SSV(SSAV)] antigens. HD sera showed significantly elevated titers against EBV and both increased incidence and mean titer of antibodies to the envelope glycoprotein of SSV(SSAV), whereas testing against the influenza viruses revealed no differences between HD and controls. A focus reduction assay demonstrated a low incidence in HD and controls of sera with neutralizing effects against SSV(SSAV) and the "baboon" C-type virus component of the human HL-23 virus complex, which seemed coupled to HL-A type W19.
Natural polyclonality of spontaneous AKR leukemia and its consequences for so-called specific immunotherapy.
Young female AKR mice made leukemic by iv inoculation of 10(3) spontaneous AKR thymoma cells were treated with repeated injections of irradiated cells from the same tumor. Treatment began 1 day after injection of the viable cells. The cytotoxicity of sera and lymphoid cells from healthy mice immunized with lymphoma cells from either treated or nontreated mice with leukemia grafts revealed that the tumor cells could be subdivided into four distinct antigenic types. One type (clone A) accounted for about 97% of the lymphoma cells in each mouse with spontaneous leukemia, whereas the remaining 3% were subdivided into three other distinct antigenic types (clones B, C, and D). Lymphoma cells from treated mice with grafted leukemia were never clone A type but either clone B, C, or D type. Repeated sc injections of 10(7) irradiated cells from spontaneous AKR thymomas induced from 15 to 34% cure in mice with grafts of leukemia cells. Treatment with only clone A induced about 32% cure, whereas treatment with clone B, C, or D had no beneficial effect. Treatment with 10(7) cells each of clone A plus clone B gave 33% cure; clone A plus clone B plus clone C, 45%; and all four clones cured 92% of the mice with leukemia grafts. The efficiency of immunotherapy may be influenced by the natural clonality of the tumor to be treated.
Arrest of cell membrane movements by in vitro incubation with polycation reversed by polyanion.
A total arrest of cell membrane movement occurred after incubation for 2 h of cultured fibroblasts with the polycation DEAE-dextran. The immobilized cells resumed normal membrane undulations after exposure for 5 min to the polyanion dextran-sulphate. The influence of DEAE-dextran on the electrophoretic mobility, which was seen after 10 min of incubation was also erased by a subsequent incubation with dextran-sulphate. No influence on growth of the culture was seen.