Search PubMed⌕ Search

Biomedical subjects

N Cajal

Publications and source records attributed to N Cajal.

At least 91 records · Page 5Linked to original sources

Protein kinase C and the antiviral effect of human interferon.

Protein kinase C (PKC) inhibitors: Hidaka's compounds H-7 (10 microM) and H-8 (20 microM), palmitoyl-carnitine (10 microM) and phloretin (50 microM), did not modify the antiviral effect of human natural or recombinant interferon alpha and of natural interferon beta. The tumor promoter 12-o-tetradecanoyl-phorbol-13-acetate (TPA) (200 nM), known as activator of PKC induced an antiviral state when tested on human embryo fibroblasts challenged with the vesicular stomatitis virus. The battery of PKC inhibitors used inhibited the antiviral effect induced by TPA. Palmitoyl-carnitine (10 microM) exerted a toxic effect that was reversed by interferon treatment (2,000 IU/ml interferon alpha). These results suggest that PKC, possibly activated by interferon-receptor interaction, is not essential for inducing the antiviral effect of interferon, but, probably, mediates the antiviral effect of TPA.

Animals↗

[The antiproliferative effects associated with vincristine and human interferons in experimental in vitro systems].

Cytotoxic potential of suboptimal doses of vincristine associated with human interferon was studied in two cell lines of tumoral origin, as compared to the action of or gamma type interferon preparations. Results show that the vincristine cytotoxic effect may be synergistically augmented in both culture types by simultaneous interferon administration.

Cell Division↗

Epstein-Barr virus (EBV). VII. Established lymphoid cell line (IVPat-88) obtained from synovial fluid of a patient with aseptic arthritis.

Attempts have been made to culture mononuclear cells from synovial fluid of 8 patients with arthropathy, and have led to the development of the lymphoid cell line IVPat-88. Cell line has been propagated by serial passages for more than 14 weeks in continuous culture. The cells grew as single, free-floating individuals, or in dense clumps without adherence to glass or plastic surface. All these cells were identified as altered lymphoblasts because of their growth pattern and uniform morphology, and the presence of Epstein-Barr Viral Capsid Antigen (VCA) in 5 to 10% of the cells. The cell concentration varied during the period of culture from about 300,000 to 1,700,000 cells per ml, and mean doubling time during phases of active growth was 42 and 60 hours in MEM and RPMI 1640 tissue culture media, respectively. The methods used and the characteristics of the cell line are described.

Antibodies, Viral↗

[Gamma interferon induced in human leukocytes by phytohemagglutinin: its production and biological characteristics].

Human gamma type interferon (IFN) preparations were obtained through phytohemagglutinin stimulation of leukocytes from the peripheral blood. Biological value of these preparations varied between 160 u and 800 u/ml, depending on leukocyte incubation medium, culture system and inductor conservation. The rising of the antiviral activity through association between gamma (3 u) and alpha (27 u) interferons was revealed by the virus quantity reduction (in this case the vesicular stomatitis virus was used) during a 24-hour multiplication cycle. The protection ensured by the mixture of the two types of interferon was about ten times higher than the additive effect of the two preparations. Study of the antiproliferative activity of a gamma interferon preparation was conducted on two human cell lines of tumoral origin (T-10 from a glioblastoma, and HEp-2) and revealed the difficulties to quantify precisely this property of the crude gamma interferon preparations.

Cell Division↗

Investigation of humoral and cell-mediated immunity aspects in mice with experimental latent herpes infection.

An experimental latent herpes infection was established by intradermal inoculation of the mouse ear or of the footpad with a wild strain and a temperature-sensitive (ts) mutant of herpes virus type 2. The wild strain was latency-positive irrespective of the inoculation site; the ts mutant induced latent ganglionic infection only when inoculated in the footpad. Neutralizing antibodies could be detected only after inoculation of the wild strain. The establishment of latency was not prevented by the presence of either a humoral or a cell-mediated immune response.

Animals↗

Structural particularities of parainfluenza type 1 (Sendai) virus progens obtained by cultivation in the presence of ceruloplasmin.

Sendai virus multiplication in the presence of ceruloplasmin resulted in the appearance of qualitatively modified progens. There was an increase in the proportion of incomplete virus particles and a decrease in hemagglutinin and neuraminidase activities, in virus infectivity and antigenicity (with the exception of subviral fractions with predominant hemagglutinating activity). Virus progens obtained in the presence of ceruloplasmin had a higher sensitivity to detergent treatment; virus ghosts formed by re-aggregation of envelope fragments could be observed in the electron microscope.

Animals↗

Preliminary data on the encapsulation of biologically active materials in liposomes.

Multilamellar and unilamellar phospholipid liposomes were prepared and investigated as regards their properties and the capacity of encapsulating biologically active materials, such as CrO4-(2-)ions, basic dyes, proteins, DNA, as well as Sendai virus particles. The efficiency of encapsulation ranged from 10% for CrO4-(2-)ions to about 80% for toluidine blue; it was found to depend not only on the type of encapsulated material, but also on the method used for liposome preparation and on liposome composition.

Animals↗

[Anti-proliferative and antiviral effects of human alpha-interferon on tumor cells].

Antiproliferative and antiviral activities of a type alpha human leukocytic interferon on several heteroploidic cell lines: HeLa, HEp-2, and T-10, a cell line of malignant origin (glioblastoma) were investigated, as compared to subcultures of human embryo fibroblasts. The tumor cell multiplication rate decreased proportionally to the amount of interferon in the culture medium. The highest interferon concentration used in our experiments (1,000 mu/ml) induced a decrease of the normal cell multiplication rate (human embryo fibroblasts). The same amount of interferon had a cytotoxic effect against the T-10 cells, but this phenomenon is reversible if the interferon is excluded after 24 h from the culture medium. There was no quantitative relation between the magnitude of the antiviral and of the cytotoxic effects of the type alpha human interferon on the tested cellular substrates.

Antineoplastic Agents↗

Computerized studies of influenza epidemiology in the Sibiu county between 1968 and 1986.

The report presents a statistical synthesis (a microcomputer Junior was used) concerning the incidence of various acute infections of the upper respiratory tract (AIURT), the stages of their evolution, the distribution of cases among the population groups, the seasonal incidence and the values of epidemiologic parameters. We used clinical and epidemiologic data on AIURT of viral etiology (especially influenza). The structure of a data base on the epidemiology of AIURT of viral etiology is also presented.

Absenteeism↗

[Assessment of the epidemiological parameters of the most widespread viral diseases in the Socialist Republic of Romania and in Sibiu County for period 1967-1986].

Essential peculiarities of the kinetics of the morbidity evolution of most frequent virus diseases were explained using a determinant mathematical model. The main epidemiological parameters for the whole territory of the S.R. of Romania and of Sibiu County were evaluated for the 1967-1986 period.

Epidemiologic Methods↗

[Different modalities for registering AIDS cases. Their importance for the European epidemic].

The high number of AIDS cases diagnosed in different European countries imposed to reconsider the opinion that European epidemic is just reflecting the American epidemic. The whole morbidity des not point out the peculiar elements of HIV infection propagation in Europe. The exponential rise of reported case number during 1987 imposes to analyse the new epidemiological situation.

Acquired Immunodeficiency Syndrome↗