Search PubMed⌕ Search

Biomedical subjects

M Fogel

Publications and source records attributed to M Fogel.

At least 55 records · Page 3Linked to original sources
PubMed1979

Differences in resistance of metastatic tumor cells and cells from local tumor growth to cytotoxicity of natural killer cells.

Cells from local tumor growth (L-3LL) were compared to metastatic tumor cells (M-3LL) for their susceptibility to the cytotoxicity of natural killer (NK) cells. M-3LL cells were more resistant in vitro to NK cells from normal spleens than were L-3LL cells. A similar phenomenon of relative resistance of metastatic cells to NK activity was found when L-3LL and M-3LL cells were admixed with normal spleen cells and then inoculated into syngeneic mice. Because hybrid resistance was shown to be based on mechanisms that in principle are similar to mechanisms involved in NK activity, we tested the growth of M-3LL and L-3LL cells in semiallogeneic F1 mice. The in vitro effect of NK cells from semiallogeneic mice on M-3LL and L-3LL cells was tested in parallel. In vitro tests showed that irrespective of the haplotype of the spleen cell donors, L-3LL cells were more susceptible to NK activity than were M-3LL cells. In vivo experiments indicated that whereas M-3LL and L-3LL cells grew similarly in syngeneic recipients, M-3LL cells grew far more in F1 mice than did L-3LL cells. Thus metastatic cells are more resistant to NK activity than are cells of the local tumor growth. This relative resistance may determine, among other factors, the metastatic spread and progression of tumor cells.

Animals↗
PubMed1978

Specific cytotoxic lymphocytes against syngeneic tumors are generated in culture in the presence of syngeneic, but not xenogeneic, serum.

Experiments were performed to test the effect of xenogeneic (fetal calf) serum (FCS) , as compared to syngeneic mouse serum (SMS) on the generation in culture of specific cytotoxic lymphocytes (CL) against syngeneic tumors. Sensitization in FCS against 3LL tumor cells resulted in CL cross-reacting with B-16 tumor cells and vice versa. Anti-syngeneic fibroblast CL also cross-reacted with 3LL. Such cross-reactivities were shown to be derived from CL directed against FCS determinants. In contrast, sensitization in the presence of SMS resulted in CL directed against tumor-specific antigens. Anti-3LL generated in SMS lysed 3LL targets but not B-16, and anti-B-16 lysed B-16 but not 3LL. The two types of CL had two distinct reactivities in vivo. Anti-3LL CL generated in FCS enhanced tumor growth in vivo, whereas anti-3LL CL generated in SMS had an inhibiting effect on the growth of tumor cells. These results indicate that the application of syngeneic serum during in vitro sensitization against syngeneic tumors may open up new possibilities for the analysis of tumor-specific antigens and for eliciting specific immune reactions against such antigens.

Animals↗
PubMed1978

Pituitary-gonadal function in XYY and XXY men identified in a population survey.

Evidence on pituitary-gonadal function in XYY subjects has been inconclusive and based, for the most part, on selected samples such as institutionalized individuals or subjects examined for particular behavioural or medical characteristics. We report the results of a double-blind hormonal study of a sample from an entire well-defined birth cohort of men. The starting population included all males born in Copenhagen during the period 1944-1947 comprising 31,436 individuals. Chromosome determinations conducted on 4139 men representing the top 15.9% of the height distribution of the sample identified 12 XYY and 16 XXY men. All the XYY subjects and 14 XXYs consented to participate in an individual case study and were individually matched to XY controls selected from the total sample. The XYY men had significantly higher plasma concentrations of LH, FSH and testosterone than matched XY controls. There were no differences in testicular size and in the reported number of children between the XYYs and control group. XXY men from the same population showed significantly higher LH and FSH, lower concentrations of testosterone, had smaller testes and reported fewer children than their matched controls.

Adult↗
PubMed1978

Effect of caffeine on the replication of nonirradiated and ultraviolet-irradiated cytomegalovirus.

The effect of caffeine on cytomegalovirus (CMV) replication in human embryo lung (HEL) and human embryo kidney (HEK) cells was studied. In HEL cultures, nonirradiated CMV yielded up to 6.7 times more plaques in caffeine-treated cultures than in control cultures. Virus growth curves exhibited different profiles, depending on the time of treatment of the cultures with the drug. Incorporation of [3H]TdR into virus DNA was enhanced and began about 24 h earlier in the caffeine-treated cultures than in the untreated cultures. A relationship between decreased incorporation of [3D]TdR into cellular DNA caused by caffeine and increased virus replication was observed in the HEL cells. In caffeine-treated HEK cultures, CMV replicated better than in untreated cultures in which virus growth was transitory and decreased after 10 days of incubation. The infectivity of CMV irradiated with UV light doses of 3,120-12,480 erg/mm2 decreased as a function of the UV dose. The extent of multiplicity reactivation of the irradiated virus increased when irradiated with higher UV doses. The effect of caffeine on the infectivity of UV-irradiated CMV depended on the dose with which the virus was irradiated. Caffeine increased the infectivity of CMV irradiated with lowest UV dose (3,120 erg/mm2) but did not increase the infectivity of virus irradiated with 12,480 erg/mm2. Multiplicity reactivation of the UV-irradiated CMV was inhibited by caffeine regardless of the UV dose with which the virus was irradiated.

Caffeine↗
PubMed1977

Luteinizing hormone and testosterone during nocturnal sleep: relation to penile tumescent cycles.

Variations of plasma LH and testosterone in relation to sleep-related penile tumescence were assessed. Plasma LH and testosterone were measured at 10-20 min intervals in five normal adult men during 2 nights of sleep. Blood samples were obtained by means of an indwelling venous catheter while sleep was monitored polygraphically and penile tumescence recorded with a penile mercury strain gauge. Tumescent episodes were recorded in all subjects during 9 of the 10 nights of the study, and the percentage of time during sleep, which was associated with tumescence, ranged from 13% to 34%. Simultaneous REM and tumescence comprised 57.7% of total tumescent time. Abrupt elevations of plasma LH and testosterone were observed during the night without a significant relationship to stages of sleep. The mean of all hormonal determinations for the five subjects did not show significant differences in plasma LH and testosterone between fully and partially tumescent episodes and nontumescent periods. Mean testosterone during REM sleep with tumescence, a state of autonomic activation involving sexual function, was consistently higher for the five subjects than during periods free from REM and tumescence.

Adult↗
PubMed1975

Activation of carcinogenic polycyclic hydrocarbons in polyoma-virus-transformed cells as a prerequisite for polyoma virus induction.

Polyoma-virus (PV)-transformed cell clones, which are inducible for virus synthesis by various physical and chemical agents, metabolize the chemically non-reactive carcinogen benzo(a)pyrene (BP) into water soluble products. In cultures of such clones, which metabolize BP to a level of 30-6-% of that of normal cells, up to 10.4% of the cells were induced for PV synthesis by BP, 20-methylcholanthrene (MCA) and 7,12-dimethylbenz(a)anthracene (CMBA). No PV induction was observed with the non-carcinogenic polycyclic hydrocarbons pyrene chrysene and benz(a)-anthracene. A proportion of subclones, isolated from a PV- inducible clone, which metabolized 0.1 mug or less BP per 10-6 cells were all inducible for PV synthesis by these carcinogens. Subclones isolated from an inducible clone pretreated with BP were shown to metabolize less than 0.1 mu BP per 10-6 cells and were resistant to virus induction by the carcinogenic polycyclic hydrocarbons. Benzoflavone, which inhibited the metabolism of BP in clones metabolizing high levels of this carcinogen, also prevented the induction of PV antigen and infectious virus synthesis in these clones. The data indicate a relationship between the carcinogenicity of polycyclic hydrocarbons and their ability to induce virus in the PV-transformed cells and suggest that virus induction depends on metabolic conversion of these hydrocarbons into similar reactive compounds that are responsible for malignant transformation and mutagenesis.

Animals↗
PubMed1972

Bioluminescence: mechanism and mode of control of scintillon activity.

Subcellular particles, termed scintillons, isolated from the luminescent dinoflagellate Gonyaulax, emit light when the pH is lowered from 8 to 5.7. The capacity to emit a second flash is regained by incubation of scintillons with the low molecular weight luciferin from Gonyaulax. This compound was previously demonstrated to be the substrate in the bioluminescent reaction catalyzed by a soluble luciferase isolated from the same cell. A model of the scintillon is presented that involves soluble elements structured within a membrane-bound particle.

Cell Membrane↗