bluuebunny/crossref_metadata_2025 huggingface dataset:
Extractable herpesvirus antigens from chickens with marek's disease
Authors: Ahmed Mumtaz , Leech Judith B. , Slattery Susan M. , Schidlovsky George
Published: February 2007

Marek's disease herpesvirus (MDHV) antigens are demonstrable by indirect immunofluorescence and micro‐immunodiffusion tests in epithelial cells of feather follicles (FF) of chickens infected with GA strain of MDHV; but lymphoid tumor cells are devoid of virus particles and virus‐associated antigens. The antigens extracted from virus‐containing epithelial cells growing in vivo or in vitro were found to be of a similar nature. Electron microscopy showed that antibody‐positive chicken sera caused specific coating of MDHV particles extracted from feather follicular cells.
Decrease in tumor‐producing capacity of mouse cell lines following infection with mouse leukemia viruses
Authors: Barbieri D. , Belehradek J. , Barski G.
Published: February 2007

Two neoplastic cell strains derived from the C57BL/6 mice, P4bis originating from normal adult lung tissue “spontaneously” transformed in vitro, and TBLC2 developed from a methylcholanthrene‐induced sarcoma, were both infected in vitro with Rauscher leukemia virus. Consecutive to this infection, the tumor‐producing capacity of these cells, which continued to multiply normally in vitro, dropped considerably when checked in syngeneic mice. This was evidenced by a dramatic decrease of takes and a significant prolongation of latency period. The high leukemogenic RRL+ and the low leukemogenic RCL− virus variants were equally efficient in infecting cells in vitro and producing a decrease of their tumorigenic potential in vivo. This decrease coincided with the massive appearance in the cells and culture supernatant of C‐type particles and of a new surface antigen reacting specifically in the immunofluorescence test with anti‐Rauscher virus serum. The specific immunological nature of decreased tumorigenicity was confirmed by the fact that the rejection of the virus‐infected cells could be prevented by total irradiation of intact recipient animals, whereas animals preimmunized and later irradiated continued to reject the infected cells. On the other hand, the rare tumors which appeared in non‐irradiated adults after a long latency period were composed of virus‐free cells whereas cells from tumors obtained by inoculation of new‐born animals regularly contained the virus and were rejected when grafted on normal adults.

In another series of experiments, in P4bis cell cultures, subjected in vitro to the action of methylcholanthrene for several months, the appearance of C‐type particles and of a new cell‐surface antigen reacting specifically in the immunofluorescence test with anti‐Gross leukemia serum, was observed. The untreated control cultures remained negative for C particles and antigen. The appearance of this chronic C‐type virus infection coincided, here again, with a considerable decrease in tumor‐producing capacity of the P4bis cells as checked in syngeneic mice.

The reported results are discussed in the context of the possible role played by chronic infections, especially by widely spread non‐pathogenic variants of leukemia viruses, in the “heterogenization” of tumor cells contributing to their rejection triggered by an immune reaction of the host.
Characteristics of established myeloma and lymphoblastoid cell lines derived from an e myeloma patient: A comparative study
Authors: Nilsson Kenneth
Published: February 2007

The in vitro characteristics of two types of cell lines established from bone marrow and peripheral blood of an E myeloma patient have been compared. Both types, one with a lymphoblast morphology and the other with plasma cell/plasmablast morphology, secreted monoclonal immunoglobulins in vitro. The former produced IgGK while the latter synthesized the IgEL myeloma protein, which in a previous report was shown to be identical with the myeloma protein in vivo.

The myeloma cells were difficult to establish and more stringent in their in vitro requirements than the lymphoblastoid cells. Myeloma cells could only grow in the presence of feeder cells or medium harvested from such cells, while lymphoblasts were capable of independent growth in standard media. The lymphoblastoid line was principally similar to those obtainable from normal lymph nodes (Nilsson et al., 1968; Nilsson, 1971a) and is therefore regarded as being of non‐neoplastic origin. It is thus possible to obtain permanent immunoglobulin‐secreting lines of non‐neoplastic origin as well as myeloma lines of neoplastic origin from patients with myelomatosis. The dynamic and static morphology of the former most closely correspond to the appearance described for lymphoblasts or “immunoblasts”,i.e. lymphocytes stimulated by phyto‐hemagglutinin, while myeloma cells resemble plasma cells of varying maturity. The reasons for the morphologic differences are unknown, but they were sufficiently distinctive to permit unequivocal distinction between the two types of lines.
Mechanism of resistance of yoshida sarcoma to nitrogen mustard
Authors: Inaba Makoto , Sakurai Yoshio
Published: February 2007

Uptake and binding of methyl‐bis(2‐chloroethyl)amine hydrochloride (HN2) to the cells of Yoshida sarcoma during their acquisition of resistance to this drug was investigated. With the increase of resistance index, drug uptake by the cells decreased. A good parallelism was found between resistance index and binding rate of the drug with cellular constituents when the intact cells were kept contacted in vitro with the drug in an incubation medium. When the cells were homogenized before contact with the drug, there was no difference in binding rate of the drug between sensitive and resistant cell lines. Suppression of cell membrane transport seemed to play a role in the acquisition of resistance by the cells.
Detection of tumor‐specific cell surface antigen of simian virus 40‐induced tumors by the isotopic antiglobulin technique
Authors: Ting Chou‐Chik , Herberman Ronald B.
Published: February 2007

Simian virus 40 (SV40) tumor‐specific cell surface antigen (TSSA) was assayed by the isotopic antiglobulin technique. Antisera were produced by immunization of A/LN mice with syngeneic SV40‐induced tumor designated SV‐A/LN. Positive reactions were only obtained with SV40‐transformed mouse or hamster cells which possessed both SV40 TSTA (tumor‐specific transplantation antigen) and T antigen. Negative reactions were obtained with untransformed cells or non‐SV40 tumors. The T antigen‐negative cells (“T‐ S+” by Tevethia et al., 1968), which lack TSTA and viral RNA or viral DNA, also gave negative reactions. Absorption experiments further confirmed the specificity. These results showed that the SV40 TSSA detected by the isotopic antiglobulin technique was virus‐specific, and was correlated with the expression of TSTA.
Ultrastructure of giant cells in tumours induced in golden hamsters by murine sarcoma virus‐harvey
Authors: Hallowes R. C. , Chesterman F. C.
Published: February 2007

Tumours induced in golden hamsters by murine sarcoma virus‐Harvey were studied in four situations: in subcutaneous tissue, on paws or distal ends of limbs, in muscle and in association with bone destruction. Most of the tumours contained multinucleate giant cells. In subcutaneous tumours, a “filament ous” type of giant cell was seen with long filamentous cell processes and bizarre‐shaped nuclei. Also present was an “interlocking” type which had short cell processes that interlocked with those of surrounding uninuclear cells. The groups of cells formed in this way resembled a granuloma. Degenerating multinucleate sarcolemmal cells were seen at the edge of muscle tumours and “vegetative” muscle cells were also present. A “pleomorphic” type of giant cell was seen in paw, muscle and bone‐eroding tumours. This was a multinucleate cell differentiated to respond to cellular damage caused by tumour infiltration. Groups of cells resembling those seen in granulomas were also present in these tumours.
Epidemiologic evidence for multi‐stage theory of carcinogenesis
Authors: Hakama Matti
Published: February 2007

A multi‐stage model of carcinogenesis is proposed assuming time homogeneous transition intensities from stage to stage. The model shows a fairly close agreement with the observed age incidence curves, not only for epithelial tumors, but also for tumors showing a more irregular age pattern. The model is applied to throw light on the mechanisms of carcinogenesis. Selected primary sites are considered and it is proposed that tumors of peripheral nerves in children and young adults are a result of a single change or hit, acute leukemia in children is probably a two‐hit disease, whereas most tumors of epithelial origin require several changes. Tumors with a bimodal incidence curve, like Hodgkin's disease and breast cancer, are likely to consist of two entities.

It is stressed that the assumption of constant transition intensities may not be true, especially in regard to tumors with conceivably long periods of exposure.

Different incidence patterns have required different interpretations on the mechanisms of carcinogenesis. The model presented in this paper provides a synthetic explanation for the genesis of different types of tumors with apparently different shapes in the age‐specific incidence curves.
An epidemiological analysis of cancer vaccines
Authors: Higginson John , de‐Thé Guy , Geser Anton , Day Nicholas
Published: February 2007

The logistic and epidemiological problems associated with the development of an effective virus vaccine for cancer are discussed. It is shown that if human tumours are caused by viruses with short latent periods, it will be possible to test the effectiveness and safety of the vaccine without following up unrealistically large control and experimental groups.

On the other hand, if the viruses concerned are non‐specific, and only a small proportion of the infected population develops cancer after a long and varied latent period, it will be very difficult to test the effectiveness of such vaccines in present society. This is due to the large number of individuals who would have to be followed up for prolonged periods.
Enhanced growth of primary moloney virus‐induced sarcomas in mice
Authors: Pierce George E.
Published: February 2007

Pre‐treatment of BALB/c mice with an intraperitoneal injection of heat‐inactivated serum obtained from BALB/c mice with progressively growing Moloney‐virus‐induced sarcomas (“progressor” mice) shortens the latent period and increases the growth rate and maximum size of primary sarcomas induced in these mice by Moloney virus inoculation 24 h after the serum injection.

Pre‐treatment with heat‐inactivated serum obtained from BALB/c mice after the complete regression of Moloney sarcomas (“regressor” mice) decreases the growth of subsequently induced Moloney sarcomas in mice so treated.

These observations are discussed in relation to the recent findings of Hellström and Hellström (1969, 1970) that serum fiom “progressor” mice blocks the cytotoxic effects of specifically immune lymph‐node cells when tested against target Moloney sarcoma cells in vitro arid that serum from “regressor” mice competes with or abrogates the blocking effect of “progressor” serum.
The mechanisms of action of anti‐tumour polysaccharides. I. The effects of antilymphocyte serum on the anti‐tumour activity of lentinan
Authors: Maeda Yukiko Y. , Hamuro Junji , Chihara Goro
Published: February 2007

Mechanisms of the regression of transplantated tumours in mice caused by lentinan, an anti‐tumour polysaccharide, were examined. 1) Lentinan showed a marked anti‐tumour effect when the animal was pretreated, starting 12 days before tumour inoculation. 2) The anti‐tumour effect of lentinan was blocked by injection of anti‐lymphocyte serum from 24 h after tumour transplantation. Lymphoid cells attacked by this serum apparently play an important role in tumour regression induced by lentinan. 3) Considering the selective actions of anti‐lymphocyte serum as an immunosuppressor, one of the mechanisms responsible for the anti‐tumour effect of lentinan may be the stimulation of cell‐mediated responses. 4) Humoral antibodies against lentinan do not seem to participate in tumour regression.
Study of the in vivo fixation of antibodies on tumors provoked in hamsters by injection of SV40‐transformed cells (TSV5Cl2)
Authors: Sobczak E. , Cyr Ch. de Vaux Saint
Published: February 2007

Large particle fraction obtained by the technique of Sjögren and Motet (1969) can be treated at acid pH, to elute immunoglobulins from hamster tumors induced by injection of SV‐40 transformed fibroblasts (TSV5Cl2). The eluate contains IgG27S, as well as two fragments having molecular weights of about 67,000; one of these, Fc, migrates in the β region, and the other, F(ab), migrates in the slow y region. This eluate, tested on TSV5Cl2in culture, contains some cytotoxic antibodies and antibodies against T antigen and cytoplasmic antigen.
Rat serum lipoproteins during carcinogenesis of the liver in the preneoplastic and the neoplastic state
Authors: Narayan K. Ananth
Published: February 2007

The serum lipoproteins of rats during carcinogenesis of the liver, induced by N‐2‐fluorenylacetamide, were investigated by disc electrophoresis, preparative ultracentrifugation and lipid and protein analyses. In the case of rats with preneoplastic livers, the very low‐density lipoproteins increased by about 100%, whereas both low‐density and high‐density lipoproteins increased by about 200% as compared with control rats. The serum lipoprotein concentrations were also determined in an additional control group of rats which were given a restricted amount of normal diet. The results established that the reduced intake of feed in carcinogen‐supplemented animals was not responsible for the elevation in serum high‐density lipoproteins. In rats bearing large, primary hepatomas, the total lipids and two lipid classes were significantly increased whereas the total serum proteins were unaffected as compared with control rats. At three different gel concentrations, no striking changes were observed in the total serum electrophoretic patterns of normal and tumor‐bearing animals. The lipoprotein concentrations obtained in this study provided the most conclusive proof to date that most of the serum lipoproteins, including HDL2(1.063 < d < 1.12.5), were significantly elevated in tumor‐bearing animals. On the basis of these and other observations, it was argued that the host serum high‐density lipoprotein concentrations were perhaps related to lipoprotein synthesis by liver tumors or the lack of it by non‐hepatic tumors such as Walker carcinosarcoma, mammary tumor or Ehrlich ascites tumor. In view of certain similarities between serum high‐density lipoproteins and cellular membraneous lipoproteins, it was proposed that these serum lipoproteins were perhaps utilized in the formation of cellular membranes.
Antigènes cellulaires transitoires du foie de rat. I. Sécrétion et synthèse des protéines sériques fetospécifiques au cours du développement et de la régénération hépatiques
Authors: de Néchaud B. , Uriel J.
Published: February 2007

Transitory cell antigens of rat liver. I. The secretion and synthesis of fetospecific serum proteins during hepatic development and regeneration

Changes in the serum concentration of albumin and α‐fetoprotein (αFP) from rat fetuses and newborns were followed by a quantitative immunoprecipitation method, using specific antisera. The concentration curves of the two proteins intersected between 1 and 2 weeks after birth. On the 32nd day, when the albumin concentration was almost at the adult level, no traces of αFP were detectable. Similarly, data have been obtained for the αFP concentration in amniotic fluid and sera from pregnant rats.

Radioimmunodiffusion techniques were used to show the incorporation of radiolabelled compounds into several fetospecific and adult serum proteins during normal development as well as during compensatory regeneration after acute poisoning of the liver.

When newborn rats and rats aged between 30 and 50 days are subjected to a series of injections of CCl4, one or several waves of αFP secretion are observed. The reappearance of αFP cannot be provoked by CCl4in rats older than 7 weeks. These facts suggest that the resurgence of αFP in hepatic injury of newborn rats and young rats is a consequence of the enhanced activity of some incompletely differentiated cell clones.
The thoracic duct lymph in Hodgkin's disease. II. Quantitative analysis of the cellular composition of the lymph
Authors: Engeset A. , Cooper E. H. , Brennhovd I. , Hoeg K.
Published: February 2007

The rate of cell output from catheterized thoracic ducts was studied in 15 patients with Hodgkin's disease. The thoracic duct lymphocyte and the peripheral blood lymphocyte were correlated. There was no correlation between the total lymphocyte output and involvement of the abdominal nodes. Abdominal node involvement increased the numbers of lymphoblasts in the lymph, and also the number of macrophages and histiocytes. Reed‐Sternberg cells and Hodgkin's cells were present in the thoracic duct lymph in all patients with involvement of the para‐aortic nodes above the L IV level. Quantitative cytochemical studies were made on the cell population.
Treatment of Kaposi's sarcoma with actinomycin‐D and cyclophosphamide: Results of a randomtzed cltnical trial
Authors: Vogel Charles L. , Templeton Christina J. , Templeton Alexander C. , Taylor John F. , Kyalwazi Sebastian K.
Published: February 2007

A randomized trial of cytotoxic drugs in the treatment of florid and infiltrative types of Kaposi's sarcoma is reported. One of 10 patients treated with cyclophosphamide and nine of 12 patients treated with actinomycin D had tumour regression, demonstrating the superiority of the latter form of therapy. Patients with florid lesions responded more rapidly and completely than those with infiltrative lesions. Histologically, those tumours with the monocellular pattern accompanied by marked fibrosis or those with anaplastic variants proved to be refractory to therapy.
Rates per 100,000 births and incidence of choriocarcinoma and malignant mole in Singapore Chinese and Malays. Comparison with connecticut, Norway and Sweden
Authors: Shanmugaratnam K. , Muir C. S. , Tow S. H. , Cheng W. C. , Christine B. , Pedersen E.
Published: February 2007

Malignant trophoblastic neoplasia (MTN), i.e. choriocarcinoma (CC) and malignant mole (MM), has long been held to be very frequent in the Far East, but reliable data have not been hitherto available for either morbidity or mortality.

Singapore cases of MTN diagnosed histologically between April, 1959, and December, 1964, were related to the population‐at‐risk by race and 5‐year age‐group, and to the numbers of live‐born infants by maternal age. As in other series, the risk increased with advancing maternal age.

The age‐standardized rates for histologically‐diagnosed MTN, CC and MM were respectively, for Chinese 1.45, 1.00 and 0.45 and, for Malays, 2.14, 1.17 and 0.97 per 100,000 per annum. The rate for histologically‐diagnosed MTN per 100,000 live births and still‐births was 18 for both races. However, as the age‐standardized gynaecological biopsy rates for Malays were but 40% of those for Chinese, and as necropsies are infrequent in Malays, the “true” rates in Malays could well be higher.

MTN histological material in Connecticut (1935–1964) was reviewed using the same criteria as for Singapore. A sample of Norwegian material (1957–1966) was examined and the Swedish data (1958–1965) published by Ringertz (1970) were based on the same histological criteria.

The age‐standardized rates for MTN, CC and MM were for Connecticut 0.09, 0.07 and 0.02, for Norway 0.22, 0.19 and 0.03, and for Sweden 0.13, 0.08 and 0.04 per 100,000 per annum. The MTN rates per 100,000 live births and still‐births were respectively 2, 6 and 4.

The Singapore incidence rates for histologically‐diagnosed CC and MM were thus significantly higher, and the number of cases of MTN per 100,000 births some three to nine times greater than in Connecticut and Scandinavia.
Serum factors in tumor‐free patients cancelling the blocking of cell‐mediated tumor immunity
Authors: Hellström Ingegerd , Hellström Karl Erik , Sjögren Hans Olov , Warner Glenn A.
Published: February 2007

It has been previously shown that lymphocytes from cancer patients can kill cultivated neoplastic cells of the type carried by the lymphocyte donors and that sera from patients with growing tumors of the respective types can specifically block the tumor‐cell destruction. The present study demonstrates that sera from all of seven tumor patients tested (one with melanoma, one with colonic carcinoma and four with breast carcinoma), who had become clinically tumor‐free, could “unblock” ( = abrogate) the blocking effect of sera from patients bearing tumors of the respective types, thus making it possible for immune lymphocytes to kill cultivated neoplastic cells in the combined presence of the “unblocking” and blocking sera.
Epidemiologic patterns of Hodgkin's Disease
Authors: Correa Pelayo , O'Conor Gregory T.
Published: February 2007

The epidemiology mid histology of Hodgkin's disease in Cali, Colombia is reported on the basis of data from the Cancer Registry and a review of slides from several of the city's departments of pathology. Comparison of the results with incidence data published by UICC and with other reports on histologic subclassification has led to the identification of several epidemiologic patterns. Pattern I is characterized by high rates in children and predominance of histologic subtypes associated with poor prognosis. Pattern III is characterized by high rates in young adults and predominance of histologic subtypes associated with better prognosis. Pattern II is intermediate. These patterns are related to the economic stratification of the communities studied, and it is suggested that many of the epidemiological variegations of Hodgkin's disease may be explained on the basis of the interplay of environmental and host etiologic factors.
Susceptibility of chromosomes from patients with Down's syndrome to 7,12‐dimethylbenz(a) anthracene‐induced aberrations in vitro
Authors: O'Brien R. L. , Poon P. , Kline E. , Parker J. W.
Published: February 2007

The susceptibility of chromosomes from seven patients with Down's syndrome to damage in vitro by 7,12‐dimethylbenz (a)anthracene (DMBA) was significantly greater than that of the chromosomes from ten healthy donors. Chromatid gaps or breaks comprised the vast majority of aberrations produced in the chromosomes of both groups. Small numbers of isochromatid exchanges and dicentric chromosomes were also observed. The lymphocytes of patients with Down's syndrome were not deficient in their ability to repair DNA damage induced by ultraviolet light or 4‐nitro‐quinoline‐N‐oxide and, at the doses used to produce chromosomal aberrations, DMBA did not significantly inhibit either replicative DNA synthesis or the repair of damage induced by ultraviolet light or 4‐nitroquinoline‐N‐oxide in normal lymphocytes or in those from patients with Down's syndrome. DMBA did not stimulate unscheduled DNA synthesis in the lymphoeytes from patients with Down's syndrome or from normal controls.
Relationship between the EBV‐associated membrane antigen on burkitt lymphoma cells and the viral envelope, demonstrated by immunoferritin labelling
Authors: Silvestre D. , Kourilsky F. M. , Klein G. , Yata Y. , Neauport‐Sautes C. , Levy J. P.
Published: February 2007

The localization of EBV‐induced, cell membrane antigens (MA) and intracellular viral capsid antigens (VCA) was studied by immunoferritin labelling. Human sera with known concordant or discordant anti‐MA and anti‐ VCA reactivities were allowed to react with intact, viable EBV‐carrier cells, and with naked and enveloped EBV‐particles. The reaction was visualized by the indirect immunoferritin test, using a rabbit anti‐human immunoglobulin conjugate. The following conclusions were drawn:

MA is a structural constituent of the viral envelope. Anti‐MA positive sera gave a consistently strong labelling of viral envelopes and of virus‐free patches on the cell membrane as well.

VCA is not present on the viral envelope and on the cell membrane. It is expressed on the surface of naked virus particles.

A multispecific anti‐HL.A serum gave a faint labelling with a small proportion of the enveloped viral particles. It could not be resolved whether this was due to the presence of HL.A antigens on some viral envelopes or, alternatively, to low anti‐MA levels in the anti‐HL.A sera.
Low molecular weight dextran and experimental metastasis growth
Authors: Hagmar Björn
Published: February 2007

The effect of low molecular weight dextran (LMD; M 4 × 104) was tested on intravenously‐induced metastases in a syngeneic tumour‐host system in mice. When given as intravenous pretreatment LMD increased the total number of gross extra‐pulmonary metastases, without significantly changing the planimetrically estimated lung and liver metastases. When, on the other hand, the same volume of LMD was given in the cell suspension, there was a further increase in gross extrapulmonary metastases and also in pulmonary metastases.

There was an interesting parellelism between these results and the effect of cell and systemic treatment with LMD on the subcutaneous transplantability of tumour cells. Both types of treatment increased the frequency of subcutaneous takes but cell pretreatment with LMD alone increased resulting tumour volumes.

The effects of LMD were not reflected in any alteration of the viability index in dye exclusion test or in the aggregability of the tumour cells.
Perfusion of isolated human fetal liver: Synthesis and release of α‐fetoprotein and albumin
Authors: Kekomäki M. , Seppälä M. , Ehnholm C. , Schwartz A. L. , Raivio K.
Published: February 2007

The synthesis of α‐fetoprotein and other fetal plasma proteins was studied by perfusion of isolated human fetal livers with an artificial medium containing leucine‐1‐14C. The rates of release by fetal liver of α‐fetoprotein and albumin were analyzed by measuring the changes in their concentrations in the perfusion medium after the first hour of perfusion. The release of α‐fetoprotein from the liver of a 14‐week fetus was 19 μg/min. At 17 weeks of gestation, the rate was 26 μg/min and, at 20 weeks, 21 μg/min. The corresponding values for albumin were 50 μg/min, 92 μ/min, and 196 μ/min. Within the same period of gestation, the plasma concentration of α‐fetoprotein decreased and that of albumin increased with advancing fetal age. The results suggest a more rapid turnover of α‐fetoprotein than albumin in vivo.

The incorporation of leucine‐1‐14Cinto serum proteins was determined by autoradiography after electrophoresis on cellulose acetate, immunoelectrophoresis, or immunodiffusion. Radioactivity was found in α‐fetoprotein, albumin, α1‐antitrypsin, Gc‐protein and α‐lipoprotein — indicating hepatic synthesis of these proteins. No radioactivity was found in IgG present in the perfusion medium, and no haptoglobin was found in the medium.
Demonstration of two distinct components in the early antigen complex of epstein‐barr virus‐infected cells
Authors: Henle Gertrude , Henle Werner , Klein George
Published: February 2007

Examination of numerous sera from patients with infectious mononucleodis (IM), Burkitt's lymphoma (BL) or nasopharyngeal carcinoma (NPC) for antibodieh to Epstein‐Barr virus (EBV) induced early antigens (EA) revealed two distinct patterns of immunofluorescence in abortively EBV‐infected Raji cells. One showed diguse (D) staining of the nucleus and cytoplasm of invaded cells, the other (R) was restricted to masses in the cytoplasm. Although D‐ or R‐reactive Raji cells became detectable at similar times after exposure to EBV, the percentages of D‐positive cells initially exceeded R‐positive cells but ultimately both were nearly equal in number. R‐positive cells almost invariably contained also D. In EBV‐exposed RPM1 64–10 cells, frequently only D was synthesized. D antigen, in contrast to R, resisted fixation by methanol or ethanol, whereas R proved more resistant than D to proteolytic enzymes. Comparative serum titration on acetone, respectively ethanol‐fixed Raji‐EBV cell smears revealed that the transitory anti‐EA response observed in many IM patients was restricted almost exclusively to anti‐D. Anti‐EA positive sera from NPC patients also showed dominantly anti‐D activity whereas, in BL sera, anti‐R was usually, but not always, dominant, often being the only antibody to the EA complex present. Preliminary tests with pronase‐treated Raji‐EBV cell smears indicated that dominantly anti‐D reactive sera from IM patients were free of anti‐R whereas such sera from NPC or BL patients usually gave positive reactions which in part, however, failed to conform with the R pattern. The possible implications of these results have been discussed.
Studies of carcino‐fetal proteins. II. Biochemical comparison of α‐fetoprotein from human fetuses and patients with hepatocellular cancer
Authors: Ruoslahti Erkki , Seppälä Markku , Pihko Helena , Vuopio Pekka
Published: February 2007

α‐fetoprotein from human fetuses and patients with a hepatocelhlar cancer was isolated and characterized. In accordance with earlier reports, the two proteins had similar electrophoretic mobilities and gave a reaction of immunological identity. They had very similar amino acid compositions. Each was composed of a single polypeptide chain with a molecular weight of 70,000. Protein from both sources had about 4 % carbohydrate with 2 moles of sialic acid per mole of protein. Tryptic digests of the isolated fetal and cancer α‐fetoproteins were compared by peptic mapping. About 30 peptides were seen and the patterns given by the two proteins were indistinguishable. Thus both fetal and cancerous liver cells produce α‐fetoproteins which are structurally indistinguishable and probably identical.
Biochemical mechanisms of drug resistance — XII. Uridine kinases from mouse leukemic cells sensitive and resistant to 5‐azacytidine
Authors: Veselý J. , Dvořák M. , Čihák A. , Šorm F.
Published: February 2007

Partially purified uridine kinases from 5‐azacytidine‐sensitive and ‐resistant leukemic cells of AKR mice were separated on a Sephadex G‐200 column. The elution profile of both enzymes was similar although specific activity of uridine kinase from 5‐azacytidine‐resistant cells was more than 50% lower than that isolated from the parental cell line. The apparent Km constants with respect to the concentration of phosphate donor and acceptor were identical for both uridine kinases, while Vmax for enzymes from the resistant line were significantly decreased.

The enzymes under study were tested for their sensitivity to SH‐blocking agents—p‐chloromercuribenzoate, N‐ethylmaleimide and iodoacetamide—and to urea, trypsin and cytidine 5′‐triphosphate. Inactivation following p‐chloromercuribenzoate affected the activity of uridine kinase from sensitive cells more markedly than that of uridine kinase from resistant ones. When the feedback effect of cytidine 5′‐triphosphate was examined, the results indicated, in both cases, a non‐competitive inhibition with respect to phosphate acceptor, Ki constant being the same (0.079 mM). Furthermore, vi/vo ratios for the intact and trypsin‐digested uridine kinases from both cell lines plotted against varying amounts of cytidine 5′‐triphosphate yielded a single curve in each instance. The significance of these findings is discussed.
Methylcholanthrene‐induced neoplasms in germ‐free RFM mice
Authors: Walburg H. E. , Cosgrove G. E.
Published: February 2007

Five‐ to six‐week‐old germ‐free RFM mice treated orally three times a week with 0.1 ml of 0.8% solution of 20‐methylcholanthrene in olive oil developed a high incidence of thymic lymphoma but no myeloid leukemia. On the other hand, 11% of males painted on the abdomen twice a week with a 5% solution of croton oil in benzene and receiving the same oral methylcholanthrene treatment developed myeloid leukemia. Methylcholanthrene with or without the croton oil in benzene treatment increased the incidence of pulmonary adenomas, but papillomas of the skin and stomach and squamous cell carcinomas of the skin were seen only in mice treated with both methylcholanthrene and croton oil in benzene. The croton oil in benzene acted as a co‐carcinogen for the induction of papillomas of the skin and stomach and squamous cell carcinomas of the skin, but not for pulmonary adenomas or thymic lymphomas. Methylcholanthrene induction of myeloid leukemia in mice painted with croton oil in benzene gives further evidence of the relationship between granulocytopoiesis and induction of myeloid leukemia.
Cellular and humoral immunity against human malignant melanoma
Authors: Fossati Giuseppe , Colnaghi Maria I. , Porta Giuseppe Della , Cascinelli Natale , Veronesi Umberto
Published: February 2007

The humoral and cellular immunological responses of melanoma patients against tumor‐associated antigens were studied by means of the indirect membrane immunofluorescence test and a microassay for cell‐mediated cytotoxicity. Melanoma target cells obtained from 22 different surgical specimens were used.

A total of 15 different sera were tested in 27 fluorescence assays. Humoral antibodies were found in all the 13 autochthonous sera tested: eight out of ten sera cross‐reacted with one or two allogeneic melanoma cells.

The 31 microassays performed with lymphocytes from 16 patients showed that effector cells specifically killed the melanoma target cells in seven out of 12 autochthonous tests and in 14 out of 19 allogeneic tests. No cytotoxicity was found when melanoma‐patient lymphocytes were tested against control cells or when control lymphocytes were tested against melanoma cells.

The observed cross‐reactivity pattern indicates that more than one tumor‐specific antigen may be present in melanoma cells.
Observations on the ultrastructure of two hamster lymphomas with particular reference to infiltrating macrophages
Authors: Birbeck M. S. C. , Carter R. L.
Published: February 2007

Two transplantable hamster lymphomas, one of which (ML) metastasizes, while the other (NML) only grows at the site of implantation, were examined in the electron microscope. The tumour cells of the two lymphomas were found to be identical except for a slightly greater amount of ER on ML; both contain the typical ultrastructural features of experimental tumour cells, including viral particles. The difference between the two tumours was found to be in the invading host macrophages. The macrophages in NML are large cells containing phagosomes filled with tumour cells in varying stages of digestion. ML also contains macrophages but these are small cells without phagosomes, which accounts for their not being found in earlier light microscope studies. That these latter cells are macrophages is evident from their membrane processes and the presence of primary lysosomes. It is therefore concluded that the difference between these two lymphomas lies not in the ability of the host macrophages to invade ML, but rather in the inability of the latter macrophages to become activated.
Tumor thromboplastin activity In vitro
Authors: Holyoke E. Douglas , Frank Arthur L. , Weiss Leonard
Published: February 2007

The thromboplastin activity of tissue culture media, before and after incubation with T‐241 Lewis sarcoma cells of mouse origin, or with embryonic mouse epithelial or muscle fibroblasts, was measured by means of a calcium reconstitution assay. Incubation of the embryonic epithelial or muscle fibroblasts increased the thromboplastin activity of the tissue culture media more than did incubation with tumor cells, even though analysis of protein showed that there were more tumor cells than normal cells present at the time of incubation. It is concluded that there is no evidence for a unique “Cancer Coagulative Factor” at least in this system. In vitro studies of the effect of trauma in increasing the release of thromboplastin activity from both normal and tumor tissues, suggest that the mutual destruction of both tissues could account for the elevated levels observed in some patients with cancer.
On the persistence of tumour initiation and the acceleration of tumour progression in mouse skin tumorigenesis
Authors: Roe F. J. C. , Carter R. L. , Mitchley B. C. V. , Peto R. , Hecker E.
Published: February 2007

Evidence has been obtained for the reversibility of initiation of carcinogenesis as evoked by 100 μ 7,12‐dimethylbenz (a)anthracene (DMBA) applied to the skin of Swiss mice. Mice exposed to twice‐weekly applications of a phorbol ester, TPA, for 15 weeks developed multiple papillomas when treatment was started 3 weeks after tumour initiation with DMBA, but very few when the interval was 50 weeks. This finding is not necessarily at variance with the postulate of the irreversibility of formation of “latent tumour cells” by subcarcinogenic doses of DMBA.

Intraperitoneal injections of urethane increased the risk of development of malignant skin tumours by mice bearing multiple papillomas as a result of previous treatment with 100 μMg DMBA and TPA as compared with intraperitoneal injections of distilled water. This finding may allow a more clear‐cut experimental definition of the stages in the process of tumour progression in mouse skin tumorigenesis.
Specific killing of tumor cells In vitro in the presence of normal lymphoid cells and sera from hosts immune to the tumor antigens
Authors: Pollack Sylvia , Heppner Gloria , Brawn R. James , Nelson Karen
Published: February 2007

Evidence is presented for specific in vitro killing of neoplastic target cells in the presence of non‐sensitized lymphoid cells and heat decomplemented sera from mice bearing the respective neoplasms or whose tumors had been removed. Such an effect was observed with sera from mice bearing Moloney sarcoma virus (MSV)‐induced and 3‐methylcholanthrene (MCA)‐induced sarcomas, and from mice whose mammary tumor virus (MTV)‐induced adenocarcinomas had been removed. Neoplastic target cell death was not characteristically mediated by such sera alone or by normal lymphoid cells in the presence of serum from animals bearing some other tumor, but appeared to be a specific, synergistically produced cytotoxicity.
Properties of an sv40‐transformed african green monkey kidney (bsc‐1) cell line
Authors: Suarez H. G. , Bourali M.‐F. , Wicker R. , Estrade S. , Cassingena R.
Published: February 2007

An SV40‐transformed BSC‐1 cell line (BSC‐SV Cl 1.1), that had been cloned twice under SV40 antiserum, sporadically produced small amounts of SV‐40 virus spontaneously. Most of the cells contained a defective virus genome, while some contained a non‐defective virus genome which was not readily reactivated. The BSC‐SV Cl 1.1 cell line was susceptible to superinfection by SV40 DNA and virus, but its capacity to support SV40 replication was consistently lower than that of infected BSC‐1 cells. This appeared to be a property of the individual cells. The ability of individual cells to initiate SV40 replication upon superinfection may depend on the multiplicity of infection. Following fusion with SV40‐transformed hamster cells containing a nondefective virus genome (TSV‐5 Cl 2), the BSC‐SV Cl 1.1 cells activated the production of SV40 virions in TSV‐5 Cl2 cells. The yield of virus depended on the cell line or subclone used.
Absence of circulating antibodies to carcinoembryonic antigen in patients with gastrointestinal malignancies
Authors: Gerfo P. Lo , Herter F. P. , Bennett S. J.
Published: February 2007

The zirconyl phosphate gel assay (Z‐gel) was used to assay sera of 265 patients for humoral activity against carcinoembryonic antigen (CEA). Included in the patients tested were 110 with non‐metastatic colon carcinoma, 122 with other gastrointestinal, breast and pulmonary neoplasms, 20 pregnant women and 13 healthy volunteers. Twenty‐five of the patients were also analyzed with molecular filtration column chromatography. Antibody activity directed against CEA could not be detected with either technique. Possible explanations for these results are discussed.
Metabolism and macromolecular binding of dibenz(a,c)anthracene and dibenz(a,h)anthracene by mouse embryo cells in culture
Authors: Duncan Margaret E. , Brookes P.
Published: February 2007

The metabolism and consequent macromolecular binding of dibenz(a,c)anthracene and dibenz(a,h) anthracene by mouse embryo cells in culture was compared at approximately equal, low doses of hydrocarbon in the medium. Both hydrocarbons were metabolized more slowly than other hydrocarbons tested previously. The binding index (the extent of reaction of the hydrocarbon with the particular macromolecule resulting from metabolism of 1 mμMmole of hydrocarbon per ml of medium to which the cells were exposed) to DNA and RNA was low for the non‐carcinogenic dibenz(a,c)anthracene and at least 10 times higher for the carcinogenic dibenz(a,h) anthracene.
The effect of transplacental administration of ddt on organ cultures of foetal mouse lung tissue
Authors: Shabad L. M. , Kolesnichenko T. S. , Nikonova T. V.
Published: February 2007

Recent data pointing to a possible oncogenic action of DDT‐one of the most widely used pesticides‐have led the World Health Organization to undertake, through the International Agency for Research on Cancer in Lyons, a collective international study on this compound. Organ cultures of foetal lung tissue from strain A mice exposed to DDT through the transplacental route showed intensive growth as compared to controls, a total of 1,076 DDT‐exposed explants and 712 controls being examined. A dose of 50 ppm (parts per million) DDT induced a diffuse hyperplasia and focal proliferations, i.e. pre‐adenomatous lesions, in the first generation. A progressively higher incidence of these lesions was observed at a dose level of 10 ppm, rising from 8.9% in the F1 generation to 39.9% in the Fa generation; however the incidence dropped in the F4 and F5 generations (30.1% and 20.1% respectively). These observations may be suggest that DDT an oncogenic agent but with only a relatively weak activity.
Progestin secretion in 3‐methylcholanthrene‐treated rats
Authors: Moon Richard C. , Young Stretton
Published: February 2007

The mechanism of deciduomata maintenance by 3‐methylcholanthrene (MCA) was investigated in normally cycling Sprague‐Dawley rats. Animals received daily injections of ovine prolactin (LTH) from days 1‐4 following estrus (pre‐trauma period). On days 5 to 8 (post‐trauma period), each rat received either daily injections of LTH, sesame oil intragastrically, or 10 mg 3‐methylcholanthrene (MCA) in 1 ml sesame oil intragastrically. Other rats were either adrenalectomized, ovariectomized or hypophysectomized at the time of uterine traumatization on day 4. Results showed that rats which were not treated with LTH but in which the uterus was traumatized did not develop deciduomata, whereas 80% of rats treated with 5 IU LTH during the post‐trauma period were positive. Rats receiving 10 IU LTH during the pre‐trauma period but untreated during the post‐trauma period did not develop deciduomata. However, 27% of rats were positive when fed oil during the post‐trauma period. In the second experiment, 1 ml oil prior to and during the pre‐trauma period resulted in all negative responses when oil was fed during the post‐trauma period. All rats receiving LTH during the pre‐trauma period followed by MCA during the post‐trauma period were positive. None of the ovariectomized or hypophysectomized rats exhibited deciduomata when treated with MCA during the post‐trauma period. However, 75% of the adrenalectomized rats showed positive reactions. These data indicated that MCA effects release of progestin in quantities sufficient to maintain deciduomata and that both the pituitary gland and ovary are essential for this reponse.
Immunological studies on mouse mammary tumors. vi. further characterization of a mammary tumor antigen and its distribution in lymphatic cells of allogeneic mice
Authors: Chang Shaoyuan , Nowinski Robert C. , Nishioka Kusuya , Irie Reiko F.
Published: February 2007

A new lymphatic cell antigen of some laboratory mice which also occurs as a tumor‐specific antigen of ascitic mammary tumors of C3H mice was discovered. This antigen is not present in normal cells of C3H/He mice and is therefore capable of eliciting tumor‐specific immune reactions in C3H/He mice carrying that particular tumor, and also appears as an alloantigen in many of the 24 strains of laboratory mice examined, such as C57Bl/6, AKR, C58, 129, C57L, H‐2H, 101, RF, SJL/J and Swiss mice.

The name “MM antigen” seems appropriate for this cross‐reacting antigen detected on the surface of lymphatic cells. The antigen is regulated by a dominant gene independent of other known alloantigens. A designation of the locus MMa was given for this newly discovered antigen.

The similarity and difference between this antigen and TL antigen are discussed.
Polycyclic hydrocarbon‐produced toxicity, transformation, and chromosomal aberrations as a function of aryl hydrocarbon hydroxylase activity in cell cultures
Authors: Benedict W. F. , Gielen J. E. , Nebert D. W.
Published: February 2007

The cytotoxic effect of benzo[a]pyrene alone in fetal rat hepatocytes in culture is prevented by phenobarbital. Benzo[a]pyrene is not toxic to HTC, A9, or HeLa cells in which aryl hydrocarbon hydroxylase activity is either absent or very low; however, benzo[a]pyrene is cytotoxic to each of these three established cell lines grown together with the liver cells in the presence of phenobarbital. Polycyclic hydrocarbon‐produced cytotoxicity is associated with chromatid breaks, whereas aneuploidy is more closely correlated with malignant transformation of hamster secondary cultures. Benz[a]anthracene or a‐naphthoflavone competitively inhibits the hydroxylation of other polycyclic hydrocarbons such as the carcinogens 7,12‐dimethylbenz[a]anthracene or benzo[a]pyrene. The exposure of fetal hamster secondary cells to excessive amounts of benz[a]anthracene prior to, during, and following treatment with 7,12‐dimethylbenz[a]anthracene prevents malignant cell transformation from occurring.