bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of metastatic potential of tumor cells in young nude mice is correlated with low levels of natural killer cell‐mediated cytotoxicity
Authors: Hanna Nabil 
Published: February 2007

AbstractOf 6‐ and 3‐week‐old nude mice given intravenous injections of murine tumor cells with well‐defined metastatic properties, only the 3‐week‐old mice developed lung tumor colonies in significant numbers. The quantitative differences in metastatic potential among tumor cell lines injected into syngeneic recipients were also maintained following intravenous injection into young nude mice. Successful metastasis in 3‐week‐old nude mice is correlated with the low levels of natural killer cell activity detected in these young recipients. Boosting of the natural killer cell activity of 3‐week‐old nude mice by the administration of bacterial adjuvants and interferon inducers significantly inhibited metastasis formation. The differences in metastasis development could not be attributed to differences in the initial arrest of tumor cells in the pulmonary vascular bed, but rather to a better survival of the arrested cells in the lungs of 3‐week‐old nude mice as compared with 6‐week‐old counterparts. We conclude that low levels of NK cell activity are associated with increased incidence of experimental metastasis.
Association of hepatitis b virus infection with hepatocellular carcinoma in american patients
Authors: Yarrish Robert L. , Werner Barbara G. , Blumberg Baruch S. 
Published: February 2007

AbstractThirty‐four patients from the Philadelphia area with hepatocellular carcinoma (HCC) were matched with colon cancer patients, lung cancer patients and blood donors according to age and sex. Sera from the four groups were tested to determine the prevalence of hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti‐HBs), and antibody to hepatitis B core antigen (anti‐HBc). Five of the HCC patients (14.7%) and none of the controls were positive for HBsAg. At least one of the three serologic markers of hepatitis B virus (HBV) infection was found in 51.5 % of the HCC patients, 5.3 % of the colon cancer patients, 11.1% of the lung cancer patients, and 10.7% of the blood donors. Twelve of the seventeen seropositive HCC patients (70.6%) were positive for anti‐HBc alone, while all of the seropositive lung cancer patients and donors were positive for anti‐HBs alone. Sera positive for any HBV marker were also tested for e antigen (HBeAg) and its antibody (anti‐HBe). Four of the HCC patients (23.5 % of the seroposi‐tives) had anti‐HBe, while none of the sera tested had HBeAg. A history of alcoholism did not appear to influence HBV seropositivity in the HCC patients. This study supports the hypothesis that HBV infection is closely associated with HCC even in areas where both conditions are uncommon. The wide disparity between seropositivity for HBsAg and anti‐hbc in the HCC patients is an unusual feature, for which an age effect may be the best explanation.
Prognosis of stage I melanoma of the skin. Who collaborating centres for evaluation of methods of diagnosis and treatment of melanoma
Authors: Cascinelii N. , Morabito A. , Bufalino R. , Esch E. P. Vander , Preda F. , Vaglini M. , Rovini D. , Orefice S. 
Published: February 2007

AbstractPrognosis of stage I melanoma of the skin was evaluated in 747 previously untreated patients observed by the WHO Collaborating Centres for Evaluation of Methods of Diagnosis and Treatment of Melanoma from September 1967 to September 1975. The mean follow‐up period of these patients was 8.9 years. Sex, maximum diameter of melanoma, elevation on skin surface, histologic type, levels of invasion and maximum tumor thickness were found to be significantly related to survival when considered one by one. However, multifactorial analysis showed that sex and maximum thickness only had a significant impact on survival of stage I melanoma patients.The effect of sex was not evident in patients with maximum tumor thickness not exceeding 2 mm (81 % 5‐year survival for males and 87% for females and a p value >0.05), while females did significantly better (p <10−4) when maximum thickness of primary was over 2 mm.
A case‐control study of diet and colo‐rectal cancer
Authors: Jain M. , Cook G. M. , Davis F. G. , Grace M. G. , Howe G. R. , Miller A. B. 
Published: February 2007

AbstractA case‐control study of cancer of the colon and rectum has been conducted in Calgary, Alberta and Toronto, Ontario, Canada. A total of 348 cases of cancer of the colon and 194 cases of cancer of the rectum were individually matched by age, sex and neighbourhood of residence to 542 population controls and frequency matched to 535 hospital controls who had undergone an abdominal operation. Each subject received a personal medical history questionnaire and a quantitative diet history questionnaire. Data on a number of potential non‐nutrient risk factors for bowel cancer and on the consumption of 9 nutrients in the 2‐month period up to 6 months before interview were analysed. The dietary data thus refer to recent diet consumed in a period antedating the diagnosis of, and in most cases symptoms from, large‐bowel cancer in the cases, and a corresponding time period in the controls. The major findings were an elevated risk for those with a history of bowel polyps, and for those with an elevated intake of calories, total fat, total protein, saturated fat, oleic acid and cholesterol. No association was seen with an elevated intake of crude fibre, Vitamin C and linoleic acid. The nutrients for which an increased risk was demonstrated were highly correlated, though multivariate analysis using logistic regression indicated highest risk for saturated fat, with evidence of a dose‐response relationship. The findings in both cancer sites, both sexes and with both sets of controls were quantitatively very similar. The population‐attributable risk for colon and rectal cancer combined was estimated from the neighbourhood controls to be 41% for males and 44% for females for saturated fat intake and 9.8% and 6.4% respectively for any history of polyps.
Comparison of steroid receptor levels in renal‐cell carcinoma and autologous normal kidney
Authors: Hemstreet George P. , Wittliff James L. , Sarrif Awni M. , Hall Miles L. , McRae Lillian J. , Durant John R. 
Published: February 2007

AbstractSince a number of renal‐cell carcinomas regress with hormonal manipulation, we have identified and measured the levels of estrogen, progestin and glucocorticoid receptors in 47 autologous pairs of normal and neoplastic kidney tissues. High‐affinity receptors for these hormones were detected in kidney tissues of both sexes by means of a dextran‐coated charcoal assay. Glucocorticoid receptors were demonstrated in renal cancer tissues for the first time, and were higher in the tumor (mean 31.3 ± sem 5.6) than in the normal tissue (mean 18.5 ± sem 3.1 fmol/mg cytosol protein). There was a significant difference in the quantities of progestin receptors (expressed as fmol/mg cytosol protein) in normal (mean 18.4 ± sem 3.3) versus neoplastic (mean 10.4 ± sem 4.0) kidney specimens (p < 0.007). There was a significant difference between the binding affinity of the progestin receptor in the male tumors (Kd = 2.2 ± sem 0.9 nM, n = 10) and that of the females, (Kd = 9.3 ± sem 6.5 nM) (p < 0.04). When an affinity of < 9.9 × I0−9M and > 10 fmol/mg cytosol protein were used as criteria for classifying a tissue as positive for progestin receptors, only 17% of tumors contained these receptors while 45% of normal tissues exhibited them. According to these criteria, no differences were observed in the frequency of occurrence of either estrogen receptors or glucocorticoid receptors in tumor versus normal kidney. Data from this study suggest that the use of endocrine therapy should be re‐examined in the treatment of renal‐cell carcinoma.
Effect of lentinan on the production of migration inhibitory factor induced by syngeneic tumor in mice
Authors: Zákány József , Chihara Goro , Fachet József 
Published: February 2007

AbstractAttempts were made to reveal the mechanism of the inhibitory effect of lentinan on methylcholanthrene‐in‐duced transplantable fibrosarcoma (A/Ph.MC.SI) isografts. Since the involvement of a delayed‐type hypersensitivity response can be supposed to operate against this syngeneic tumor, the enlargement of regional lymph nodes, the DNA synthesis activity and the migration inhibitory factor producing capacity of the regional lymph‐node cells were studied in the control and lentinan‐treated, tumor‐bearing mice at different times after tumor implantation. The only parameter affected until the first sign of tumor inhibition on the 8th day was the MIF‐producing capacity. Regional lymph‐node cells in the lentinan‐treated mice showed a peak response at this time while practically no MIF was produced by cells of non‐treated mice. The early phase of the developing anti‐tumor reaction (enlargement of and proliferation in the lymph nodes) was initiated in all recipients but only some of them could reject the tumor in the non‐treated group in contrast to lentinan‐treated animals that rejected the tumors in all cases. It can be supposed that a tumor‐induced immunosuppression emerges in the tumor‐bearers and can be overcome by lentinan treatment, most likely through enhancement of the MIF production. For measurement of MIF activity a continuously dividing in vitro macrophage‐like cell line was established and employed in the microwound migration assay.
In vitro NK‐activity and in vivo resistance to leukemia: Studies of beige, beige/nude and wild‐type hosts on C57BL background
Authors: Kärre Klas , Klein Gunnar O. , Kiessling Rolf , Klein George , Roder John C. 
Published: February 2007

AbstractThe bg mutation in C57BL mice causes a partial impairment of NK activity, and has therefore been proposed as a model to evaluate the in vivo function of NK cells. In thepresent report, we studied natural resistance against the ascitic lines of one chemically and two virally induced syngeneic leukemias in C57BL bg/bg mice and their phenotypically normal heterozygous +/ bg littermates. S.c. threshold inocula of all three leukemia lines grew faster and caused death earlier in bg/bg than in +/bg mice, and two of the lines were rejected completely at a significantly higher frequency in +/bg control animals. The +/bg mice also eliminated [125]‐IdUrd‐labelled leukemia cells at a faster rate than bg/bg mice, as measured by pulmonary, hepatic and splenic radioactivity retained 18‐30 h after i.v. injection Direct splenic killing of 51Cr‐labelled leukemia cells was also studied in vitro, and was found to be severely depressed in bg/bg compared to +/bg. This natural killer activity was independent of adherent cells and showed a rapid, but transient, increase after inoculation of the tumor cell doses used in the transplantation tests. It was also possible to study the bg mutation in T‐cell‐free mice, by combining it with the nu mutation on a C57BL background. The NK activity of such beige‐nude mice was found to be partially impaired compared to nude (non‐beige) or wild‐type animals, but higher than that of beige (non‐nude) mice. Our results suggest that NK cells may be responsible for elimination of small numbers of tumor cells in the intact syngeneic host. The further use of beige and beige‐nude mice in studies of transplanted and primary tumors is discussed.
THE EFFECT OF DIET ON AUTOGENOUS IMMUNITY TO MOUSE MAMMARY TUMOR VIRUS IN C3H/Bi MICE
Authors: Day Noorbibi K. , Fernandes Gabriel , Witkin Steven S. , Thomas Edward S. , Sarkar Nurul H. , Good Robert A. 
Published: February 2007

AbstractAntibody levels to mouse mammary tumor virus (MuMTV) in sera of C3H/BI, C57BL/6 and AKR mice were assayed by an enzyme‐linked immunosorbent assay (ELISA). It was found that antibody levels to MuMTV were highest in sera of C3H/Bi females which have a high incidence of breast cancer and low in male C3H/Bi and female C3H/Bi foster‐nursed on C57BL/‐6 females. Sera of C57BL/6 and AKR mice showed very low or undetectable levels of antibody to MuMTV. Reduction of caloric intake sufficient to inhibit mammary tumor formation strikingly inhibited formation of antibody against MuMTV. The lowest levels of antibody were observed in sera of mice fed 10 cal/day of a defined diet. Significantly higher levels developed in the sera of mice fed 16 cal/day of the same defined diet. The highest antibody levels against MuMTV, however, were seen in sera of mice fed lab chow ad libitum but no correlation was evident between levels of antibody and tumor size. These studies indicate that dietary caloric restriction has a profound influence on the development of both mammary adenocarcinoma and antibody responses to MuMTV.
Inhibition of endogenous murine retrovirus expression by L‐β‐3, 4‐dihydroxyphenylalanine (l‐dopa) methyl ester
Authors: Suk William A. , Ceccorulli Lisa M. , Long Cedric W. 
Published: February 2007

AbstractInduction of endogenous xenotropic type‐C virus from Kirsten sarcoma‐virus‐transformed BALB/c (K‐BALB) mouse cells was inhibited by short‐term exposure to L‐β‐3, 4‐dihydroxyphenylalanine (L‐dopa) methylester. Partially synchronized cells cultured for 1–4 h with 0.8–1.6 mM L‐dopa methyl ester and subsequently induced with 5‐iododeoxyuridine (IdUrd), cycloheximide and histidinol showed inhibition of virus activation. Incorporation of thymidine, uridine and leucine was measured at the end of the drug treatment and during the subsequent induction period. L‐dopa methyl ester had a pronounced effect on DNA synthesis, reducing it by more than 85% during a 4‐h incubation period, whereas RNA and protein synthesis remained largely unaffected. Removal of the drug and replacement with fresh medium did not reverse DNA synthesis or virus activation during the subsequent induction interval. L‐dopa methyl ester was also shown to potentially function as an analogue of tyrosine in this cell system. These results suggest that inhibition of virus induction may be caused by inhibiting the normal progressing of cells through the S phase of the cell cycle.
Lymphotoxin: An anticarcinogenic lymphokine as measured by inhibition of chemical carcinogen or ultraviolet‐irradiation‐induced transformation of syrian hamster cells
Authors: Evans Charles H. , Dipaolo Joseph A. 
Published: February 2007

AbstractSyrian‐hamster‐derived lymphotoxin inhibits benzo(a)pyrene and ultraviolet carcinogen‐induced in vitro morphologic transformation of diploid secondary passage hamster embryo cells. When lymphotoxin is added up to 4 days post carcinogen, the reduction in the frequency of morphologic transformation 6 days after carcinogen treatment varies directly with lymphotoxin concentration. The frequency of transformation does not change following re‐feeding with lymphotoxin‐free medium and incubation for 6 additional days. Furthermore, transformation by ultraviolet is prevented when cells are pulsed with lymphotoxin for as few as 6 hours after irradiation. Thus, lymphotoxin has the potential to irreversibly inhibit the first recognizable morphologic step of carcinogenesis.
Lack of correlation between in vivo and in vitro assays for the detection of virus released from clones of friend erythroleukemia cells
Authors: Bertolini Luisa , Revoltella Roberto , Bendinelli Mauro , Friend Charlotte 
Published: February 2007

AbstractThe biological properties of the virus synthesized by 18 clones of a line of mouse bone‐marrow hematopoietic cells transformed in vitro by the polycythemic strain of Friend leukemia virus (FLV‐P) were compared. In vitro assays were performed to determine whether the virus released into the culture fluids was ecotropic or xenotropic, and in vivo assays were carried out to determine spleen focus formation and leukemogenicity in susceptible DBA/2J and BALB/c mice. A number of clones released virus which reproduced the entire range of effects typical of the FLV‐P complex. However, in other clones, there appeared to be no correlation between the assays for leukemogenicity and the assays for either ecotropic virus, reverse transcriptase activity, or virus antigens. Xenotropic virus was not detected in any of the cultures. These results suggest that the FLV‐P complex contains a heterogeneous population of viruses, but the possibility that the differences observed may be due to the inability of FLV‐P to be expressed fully in some clones cannot be excluded.
Metabolic inhibitors render ‘resistant’ target cells sensitive to natural killer cell‐mediated lysis
Authors: Kunkel Lori A. , Welsh Raymond M. 
Published: February 2007

AbstractL‐929 cells were lysed by activated but not by endogenous natural killer (NK) cells, as reported previously. Nevertheless, L‐929 cells bound to endogenous NK cells, as shown by target binding cell, cold target competition, and monolayer absorption assays. Treatment of L‐929 cells with actinomycin‐D or cycloheximide rendered them sensitive to lysis by endogenous NK cells and markedly increased their sensitivity to lysis by activated NK cells. Treatment with these drugs under the prescribed conditions did not affect the binding of L‐929 cells to NK cells. Since others have shown that treatment with these drugs inhibits membrane repair processes and renders cells more sensitive to complement‐mediated lysis, we hypothesize that membrane repair may be an important factor influencing a cell sensitivity to NK cells. This may be more important than NK‐binding ability, since most cells can be lysed by (and therefore bind to) activated NK cells.
Induction of a malignant lymphoreticular cell line which displays spontaneous killer‐cell activity
Authors: Kerbel R. S. , Roder C. , Pross H. F. 
Published: February 2007

AbstractThe origin and properties of a new malignant „spontaneous killer”︁ cell line are described. The tumor, known as M9‐78, was produced by treatment of tissue cultures consisting mostly of dividing DBA/2 mouse macrophages with the chemical carcinogen, 3‐methyl‐cholanthrene. Logarithmic phase cultures were treated for 6 days followed by further culture for 1 month in the absence of carcinogen. Subcutaneous injection of normal DBA/2 mice with 2.0 × 105 cells led to the formation of palpable tumors at the site of inoculation within 14 days; the tumors grew progressively and were highly metastatic. The malignant cells, though Fc‐receptor‐positive, did not possess many other properties normally associated with macrophages; morphologically, they bore a strong resemblance to bone‐marrow‐derived promonocytes. Because promonocytes have been shown previously to possess both antibody‐dependent killer (K) cell as well as antibody‐independent spontaneous killer‐cell function, the M9‐78 cells were tested for these biologic activities. The following results were obtained: (1) adherent, but not non‐adherent, M9‐78 tissue culture cells spontaneously killed a wide variety of (though not all) tumor‐cell‐line targets in long‐term (18‐24 h) 51Cr release, whereas no killing was seen in short (4 h) assays; (2) the cells were not capable of killing nucleated targets by antibody‐dependent cell‐mediated cytotoxicity; (3) a number of clones were obtained and tested for spontaneous killer‐cell activity: some were highly active, whereas others were negative, with different patterns of specificity being evident; (4) the clones were unstable; (5) the pattern of target killing, when compared to normal spleen control NK cells, suggested the M9‐78 cells were similar to activated macrophages or promonocytes in their target selectivity, although no definitive evidence was obtained which could implicate a promonocyte or monocyte origin for the cells.
Mutants of adenovirus type 12 after adaptation to growth in tumor cell lines. II. Reproducible acquisition of additional sequences after adaptation to a human cervical cancer line
Authors: Kruczek Ingeborg , Schwarz Elisabeth , Hausen Harald Zur 
Published: February 2007

AbstractAdaptation of adenovirus type 12 to growth in a human cervical cancer line (C4/1) results in the reproducible selection of viral mutants carrying additional DNA sequences at the right‐hand end of the genome which range in size from 190 to 400 base pairs. The viral mutants have selective growth advantage in comparison to the non‐affected wild type, even after subsequent passages in human KB cells, commonly used for adenovirus propagation. Detailed restriction endonuclease analysis of one of the mutant DNAs shows that the additional sequences are located within the terminal 195 base pairs of the right end of the genome.
Sister chromatid exchange and growth kinetics in untreated acute leukemia
Authors: Becher Reinhard , Zimmer Gabriele , Schmidt Carl G. 
Published: February 2007

AbstractSister chromatid exchange (SCE) frequency has been analysed after short‐term culture of leukemic bone marrow cells of eight untreated patients with acute leukemia. Compared to normal bone marrow, results show a statistically significant decrease of SCE (p < 0.001) in euploid as well as in aneuploid leukemias, ranging from 2.11 to 2.97 SCE per metaphase. The different SCE values were not related to contraction status of chromosomes and could not be explained by the age of patients. Therefore, low SCE may be a typical feature of leukemic cells. An examination of growth rates by the SCE technique revealed a high turnover of normal bone marrow cells. About 80% of the cells did not need more than 50 h to run two or three cell cycles. Leukemic cells, however, apparently divided more slowly, which is in good agreement with data obtained by autoradiographic methods.
Antibody‐induced augmentation of murine natural killer cell activity
Authors: Brunda Michael J. , Herberman Ronald B. , Holden Howard T. 
Published: February 2007

AbstractAntibodies reactive with effector cells were shown to augment the cytotoxicity of spleen cells from athymic nude and euthymic mice. The addition of alloantibody to the assay or pretreatment of the effector cells with alloantibody resulted in increased cytotoxicity against the human cell K562, a relatively poor target for spontaneous mouse NK activity. When monoclonal antibodies were tested, cytotoxicity was markedly increased by some antibodies, such as anti‐H‐2, anti‐la, and anti‐Thy 1.2, while others had no effect. The degree of augmentation of cytotoxicity was dependent on the concentration of antibody added. Nylon‐wool‐nonadherent nu/nu splenic effector cells mediated the antibody‐induced cytotoxicity and anti‐asialo GMI plus complement abolished activity, indicating that the cells mediating the cytotoxicity were NK cells and not mature T cells, B cells or macrophages. When spleen cells from mice having different levels of NK activity were evaluated in this system, the magnitude of augmentation by antibody correlated with the level of spontaneous NK activity and no increased cytotoxicity was found with cell populations that had low spontaneous NK activity. Testing a panel of target cells, showed that certain human and mouse cell lines, with low to moderate susceptibility to spontaneous NK activity, were sensitive to antibody‐induced NK‐cell‐mediated cytotoxicity whereas others were completely resistant. Both Fc‐IgG receptor‐positive and ‐negative cell lines were susceptible target cells. These results indicate that antibodies reactive with murine NK cells can increase their cytolytic activity.