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Biomedical subjects

F Wild

Publications and source records attributed to F Wild.

At least 37 records · Page 2Linked to original sources
PubMed1992

Characterization of an R-binding site mediating the R-induced activation of the Epstein-Barr virus BMLF1 promoter.

In cells latently infected with Epstein-Barr virus, the switch from latency to productive infection is linked to the expression of two Epstein-Barr virus transcription factors called EB1 and R. R is an enhancer factor, and an R-responsive element (RRE) has been identified in the BMLF1 promoter. In this study, we have used bidirectional deletion mutagenesis to delineate the BMLF1 RRE (RRE-M) to a 44-bp sequence. We also show that R expressed from a recombinant vaccinia virus protects RRE-M against digestion by DNase I. Using mobility shift assays and dimethyl sulfate interferences, we have characterized the contact points between in vitro-translated R and the DNA. R binds in vitro to one site by simultaneously contacting two sequences within the site, which are separated by 8 bp: 5'-catGTCCCtctatcatGGCGCagac-3'. Site-directed mutagenesis of this sequence completely impaired the binding of R in vitro and rendered the BMLF1 promoter nonresponsive to R. The results suggest that the R-inducible BMLF1 enhancer is composed of a single R-binding site, called RRE-M.

Binding Sites↗
PubMed1991

[Infection with Serratia marcescens in newborn infants. Clinical aspects, therapy and disease course].

Until the 1950's Serratia marcescens was generally considered as non-pathogenic for humans. Since then the organism has been reported repeatedly as a cause of nosocomial infections. The major clinical concern about Serratia marcescens is its implication in epidemic infections and its resistance to usual antibiotics causing therapy to be difficult. We report the occurrence of Serratia marcescens as the cause of severe septicemia in three premature infants. Two infants showed a severe course of sepsis, the third infant suffered from additional meningitis and a brain abscess. All infants survived, but only one had no sequela.

Anti-Bacterial Agents↗
PubMed1991

[Physiologic and pathologic rebound nystagmus. Description and comparison].

Using a binocular, infrared charged coupled device (CCD), an eye tracker coupled with an Olivetti M24 PC (resolution up to 0.1 degrees, scanning with 80 frames/s), the eye movements of 20 normal individuals with normal visual acuity and binocular function were recorded to detect physiological endpoint (EPN) and rebound nystagmus (RN). Each subject was asked to fixate a target located in the primary position (PP) and after 5 s of recording time, to look at a target either 50 degrees to the right or left of the PP for approximately 20 s and then return for the last few seconds to the PP, EPN recordings were made with the room lights on and RN recordings were made both with the lights on and in total darkness. A forehead and chin rest with bite board were used. Twelve of the 20 subjects showed EPN and RN with the lights on. The 8 subjects that did not demonstrate EPN also showed no RN with the lights on. Recordings from all 20 subjects showed RN in darkness. No differences in amplitude were found between the abducted and adducted eyes. Although clear differences in the characteristics of gaze paretic or drug-related lateral gaze nystagmus and EPN have been found, no systematic differences in RN under lighted conditions had been observed between patients and normal subjects.

Adult↗
PubMed1990

Effect of drugs which inhibit cholesterol synthesis on syncytia formation in vero cells infected with measles virus.

We found that nontoxic doses of two inhibitors of cholesterol synthesis, namely W-7 and cerulenin, delayed syncytia formation in vero cells infected with measles virus. To correlate syncytia formation and lipidic membrane changes induced by these drugs, we labelled cell lipids with [14C]acetate. Measles virus infection increased the incorporation of radiolabel into fatty acids, triacylglycerol, cholesterol ester, and decreased its incorporation into cholesterol and 1,2-diacylglycerol. The ratios phosphatidylcholine/sphingomyelin and free cholesterol/lanosterol-dihydrolanosterol also decreased during the infection. W-7 and cerulenin greatly altered lipid metabolism. Both decreased the phosphatidylcholine to sphingomyelin and the cholesterol to lanosterol-dihydrolanosterol ratios. Z-D-Phe-L-Phe-L-Gly, a tripeptide which corresponds to the N-terminal sequence of the viral fusion protein (responsible for syncytia formation) and which inhibits virus-induced cell fusion without affecting virus synthesis also perturbed cholesterol metabolism. The tripeptide reversed the phosphatidylcholine to sphingomyelin ratio in infected cells. At non-toxic doses, W-7 inhibited the synthesis of infectious virus. Cerulenin which inhibited strongly the lipid synthesis did not. Finally, the well characterized inhibitors of cholesterol synthesis, mevinolin, ketoconazole and miconazole were shown to inhibit the syncytia formation. We conclude that the inhibition of syncytia by W-7 and cerulenin is associated with their capacity to alter the cholesterol metabolism, whereas the antiviral effect of W-7 does not seem related to this capacity.

Acetates↗
PubMed1990

Fowlpox virus recombinant encoding the measles virus fusion protein: protection of mice against fatal measles encephalitis.

A recombinant Fowlpox virus engineered to encode the measles virus fusion protein was shown to protect mice against a challenge measles infection. A vaccine dose of about 10(6) p.f.u. was needed to protect nearly 100% of the animals. Mice failed to develop a significant level of antibodies directed against measles virus suggesting that other components of the immune system may be involved.

Animals↗
PubMed1990

Contribution of measles virus fusion protein in protective immunity: anti-F monoclonal antibodies neutralize virus infectivity and protect mice against challenge.

To study the contribution of the measles virus fusion (F) protein in the immune response, anti-F monoclonal antibodies were prepared by using a vaccinia-measles virus F recombinant. In contrast to previously described anti-F monoclonal antibodies, these antibodies not only neutralized virus infectivity and inhibited fusion but also passively protected mice. Since these monoclonal antibodies recognize a configurational epitope, presentation of the antigen during infection may play an important role in the immune response. These factors are discussed in relation to vaccination.

Animals↗
PubMed1989

Expression of measles virus nucleoprotein in Escherichia coli: use of deletion mutants to locate the antigenic sites.

Three distinct antigenic determinants on the nucleoprotein (NP) of measles virus were localized. These epitopes were defined by three monoclonal antibodies, one of which recognized all measles virus field strains examined, whereas the other two were variable. A measles virus NP cDNA subclone representing 502 of the 525 amino acids was cloned into a bacterial expression vector plasmid (pRIT) and expressed as a Protein A-NP fusion protein in Escherichia coli. The expressed protein reacted with all three monoclonal antibodies. A series of NP gene deletion was constructed in order to locate the antigenic sites. The antigenic site identified on all measles virus strains studied, which was designated site I, was located between amino acids 122 and 150. The two variable epitopes were located at the C terminus of the protein (site II at 457 to 476; site III at 519 to 525). The structural and biological implications of these observations are discussed.

Amino Acid Sequence↗
PubMed1989

[Sonographic diagnosis of alobar holoprosencephaly].

The alobar form of holoprosencephaly is characterised by a huge spherical ventricle localized in the midline. The monoventricle communicates with a large occipital cyst, the "dorsal sac". Both thalami and plexus chorioidei are fused in the midline. The interhemisperic fissure and the falx cerebri are absent as well as the corpus callosum and the septum pellucidum.

Abnormalities, Multiple↗
PubMed1988

Relationship between membrane sterol composition and responsiveness to 12-O-tetradecanoylphorbol 13-acetate in HL-60 human promyelocytic leukaemia cell lines.

We have examined the sterol composition and metabolism of promyelocytic leukaemia cell lines (HL-60) after treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA). A variant cell line (Blast II cells) which is resistant to TPA was used as control. Analysis of the sterols of TPA-sensitive cells radiolabelled with [3H]leucine, [14C]acetate or [14C]pyruvate showed a high incorporation into cholesterol and a low incorporation in lanosterol + dihydrolanosterol. The inverse relationship was observed in TPA-resistant cells. Experiments with other cellular variants representing TPA-sensitive and TPA-resistant classes gave similar results. Analysis of the cellular sterol composition by gas chromatography confirmed that TPA-resistant cells are particularly rich in lanosterol/dihydrolanosterol. TPA treatment enhanced the incorporation of [14C]pyruvate into the sterol fraction of both cell types. This was accompanied by an alteration of incorporation into several lipids, particularly phospholipids. Pulse-chase studies with [14C]acetate revealed that TPA induced the release of radioactive lipids into the medium from HL-60 and Blast II cells. However this treatment released phospholipids from the TPA-sensitive cells and sterols and fatty acids from the TPA-resistant cells. We conclude that the sterol composition can regulate specific biochemical processes in the membrane and can be considered as a factor that plays a role in the responsiveness of HL-60 cells to TPA.

Acetates↗
PubMed1988

Protection of mice from fatal measles encephalitis by vaccination with vaccinia virus recombinants encoding either the hemagglutinin or the fusion protein.

Vaccinia virus recombinants encoding the hemagglutinin or fusion protein of measles virus have been constructed. Infection of cell cultures with the recombinants led to the synthesis of authentic measles proteins as judged by their electrophoretic mobility, recognition by antibodies, glycosylation, proteolytic cleavage, and presentation on the cell surface. Mice vaccinated with a single dose of the recombinant encoding the hemagglutinin protein developed antibodies capable of both inhibiting hemagglutination activity and neutralizing measles virus, whereas animals vaccinated with the recombinant encoding the fusion protein developed measles neutralizing antibodies. Mice vaccinated with either of the recombinants resisted a normally lethal intracerebral inoculation of a cell-associated measles virus subacute sclerosing panencephalitis strain.

Animals↗
PubMed1987

12-O-tetradecanoyl phorbol 13-acetate stimulates the myristylation of an approximately 82 kDa protein in HL-60 cells.

We have studied protein acylation using [3H]myristate in the two leukemia cell lines HL-60 and HL-60 Blast II. The latter is a variant which does not differentiate after treatment with 12-O-tetradecanoyl phorbol 13-acetate (TPA). The acylation profiles of the two cell lines as examined by SDS-PAGE differed. TPA induced the myristylation of an approximately 82 kDa protein in the sensitive cells, but not in the resistant cells. Myristic acid was shown to be covalently linked to these proteins. Analysis of the cell lipids labelled with [3H]myristate showed that in contrast to observations with the proteins, the changes induced by TPA were observed in both TPA-sensitive and TPA-resistant cells. We conclude that the induction of myristylation may be an important step in the mechanism of differentiation.

Acylation↗
PubMed1985

Paramyxovirus antigens in osteoclasts from Paget's bone tissue detected by monoclonal antibodies.

The fluorescent antibody technique using both monoclonal and specific polyclonal virus antibodies was applied to investigate the nature of the inclusions seen in the abnormal osteoclasts associated with Paget's bone disease. The results show that antigens of measles virus, simian virus 5 (SV5) and human parainfluenza virus type 3 (PF3) could be detected in the osteoclasts but not in control bone cells. Measles and SV5 nucleoprotein (NP) and haemagglutinin-neuraminidase (HN) antigens were apparently present in all the cases of Paget's disease examined, whereas PF3 NP and HN antigens were present only in some of the cases. These investigations suggest that paramyxoviruses may play a role in the aetiology of the bone disease.

Antibodies, Monoclonal↗
PubMed1983

Monoclonal antibodies against platelet membrane glycoproteins. Characterization and effect on platelet function.

The specificity of five monoclonal antibodies (P1-P6) against platelet surface components was determined by immunoprecipitation of surface-labelled platelets from normal donors and patients with known platelet glycoprotein defects, followed by analysis by gel electrophoresis. Three (P2, P4 and P6) precipitated glycoproteins IIb and IIIa and, in addition, P2 precipitated glycoprotein Ia. P1 precipitated normally only glycoprotein Ib also Ia when the platelets were pretreated with neuraminidase. P3 precipitated principally glycoprotein Ia but glycoprotein Ib was also weakly precipitated. The effects of the monoclonals on platelet function were tested. P1 and P2 completely inhibited and P3 slightly inhibited thrombin-induced platelet aggregation. P2 also inhibited collagen-induced aggregation and partially inhibited ADP-induced platelet aggregation. P3, P4 and P6 partially inhibited ADP-induced platelet aggregation. None had any effect on ristocetin-induced aggregation despite P1 and P3 binding to glycoprotein Ib. These results confirm the role of glycoproteins IIb and IIIa in aggregation induced by various agents and suggest that the function of glycoprotein Ib in thrombin-induced aggregation is more important than previously suspected and that glycoprotein Ia may also be involved in platelet functions.

Animals↗
PubMed1979

A study of the measles virus-induced proteins incorporated into the cell membrane.

The polypeptide composition of a measles virus isolate from a case of subacute sclerosing panencephalitis, the Halle strain, and the distribution of these polypeptides in the cell membrane have been investigated. In purified virus preparations, four major polypeptides were identified with molecular weights corresponding to 80K, 62K, 42K and 37K daltons. A minor band was found at 69K and several others with molecular weights +/- 100K. By specifically labeling the proteins exposed at the surface of BGM cells either persistently or lytically infected with the Halle virus, it was shown that only the 80K and 42K viral polypeptides were present in the cell membrane. Furthermore, it was observed that PAGE profiles of cellular polypeptides differed between infected and noninfected cells.

Antigens, Viral↗