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Biomedical subjects

F Golini

Publications and source records attributed to F Golini.

13 recordsLinked to original sources
PubMed1994

Expert systems in the control of animal cell culture processes: potentials, functions, and perspectives.

In recent years, the development of advanced systems for bioprocess monitoring and control has become an area of intensive research. Along with traditional techniques, there are several new approaches which are increasingly being applied to bioprocess operations. Among these, of special note is expert system technology, which provides possibilities for the design of efficient bioprocess control systems with new functional capabilities. This technology has been successfully applied to variety of microbial processes at laboratory and industrial scale. The present paper analyzes the possibility for application of expert systems to animal cell cultures processes whose high complexity is well suited to expert control. The discussion focuses on the organization and the functionality of the intelligent control systems, and covers some practical aspects of their design.

Animals↗
PubMed1994

Real-time biomass-concentration monitoring in animal-cell cultures.

The accurate, on-line measurement of cell concentration in animal-cell cultures is an on-going problem in bioprocess engineering, and the development of new monitoring techniques is an area of intensive and fruitful research. This article summarizes the recent advances, trends and problems in this field and focuses, in particular, on optical sensors, including the latest laser and infrared probes. Alternative methods, such as multiple-extinction fluorimetry, real-time imaging and particle-size analysis, are also discussed. Although many of these techniques are still at an experimental stage, we believe that some of them have been developed sufficiently that we advocate their routine use in bioprocess monitoring and control.

Animals↗
PubMed1985

A soluble transcription system derived from purified vaccinia virions.

A soluble extract from purified vaccinia virus particles has been developed which displays site-specific initiation of transcription on exogenous DNA templates that carry cloned vaccinia virus early gene sequences. Bacterial plasmid vectors with segments of a strongly expressed early region of the vaccinia virus genome were active templates, whether in supercoiled or linear, truncated forms. Correct initiation, corresponding to that found in vivo, was observed for all early genes tested. The involvement of other factors besides the viral RNA polymerase was demonstrated by the loss of specific initiation upon partial purification of the enzyme. Initiation activity was restored by reconstitution of the system with factors lacking polymerase activity. The soluble system retained properties of transcription characteristic of intact viral cores, including (i) similar relative rates of initiation of various genes, (ii) multiple requirement for ATP, (iii) methylation and polyadenylation of transcripts, and (iv) inhibition by a topoisomerase antagonist.

Base Sequence↗
PubMed1984

Transcriptional and translational analysis of a strongly expressed early region of the vaccinia virus genome.

A transcriptional and translational map was obtained for a 7-kilobase pair EcoRI fragment of vaccinia virus DNA containing 4% of the viral genome. This particular region contains a cluster of early genes which are transcribed in viral cores in vitro and in infected cells before uncoating of the viral DNA. Expression of this region was characterized by using vaccinia virus DNA sequences cloned in phage and plasmid vectors. Polypeptides encoded on the 7-kilobase pair fragment were identified by cell-free translation of viral mRNA selected by hybridization to immobilized DNA fragments. Early RNA programmed the synthesis of six proteins having apparent molecular weights of 63,000, 38,000, 37,000, 25,000, 15,000, and 13,000. The same result was obtained with RNA synthesized in vitro. A new species of 40 kilodaltons was synthesized in response to late RNA. Of the six "early" polypeptides, only the 13-kilodalton component was synthesized from late mRNA. RNA derived from the 7-kilobase pair region was analyzed by a variety of methods including hybridization blot, in vitro recapping, and S1 nuclease techniques. A surprisingly complex pattern of early transcription was found, indicating the existence of families of overlapping RNA species which share common 5'-proximal sequences. In addition, larger RNAs were identified spanning two or more adjacent genes. These RNAs appear to possess a common 5' terminus with transcripts derived from the first gene and are coterminal at the 3' end with RNAs from the downstream gene. Late RNA encoding the 40-kilodalton protein was shown to be heterogeneous in size. A single 5' terminus but no unique 3' terminus was identified for this class of transcripts. RNA species synthesized by cores in vitro were of similar size to authentic transcripts isolated from infected cells at early times.

Animals↗
PubMed1980

Protein-linked RNA of poliovirus is competent to form an initiation complex of translation in vitro.

Poliovirus RNA that had been labelled with 125I in the 5'-terminal protein (VPg) was found competent to form an initiation complex of translation in a cell-free reticulocyte lysate. In conditions of ribosome binding, no cleavage occurred between VPg and RNA. We conclude that removal of VPg from poliovirus RNA is not a prerequisite for this RNA to initiate translation in vitro.

Cell-Free System↗
PubMed1980

Picornaviral VPg sequences are contained in the replicase precursor.

It has previously been shown that the RNA replicase of encephalomyocarditis virus contains two virus-coded proteins, D and E, which are produced in two successive proteolytic steps: (i) C leads to D + ?; and (ii) D leads to p22 + E. It is here shown (i) that virus protein H (molecular weight, 12,000) is the previously unidentified product of the first step and (ii) that VPg, a protein linked covalently to the virion RNA, yields two tryptic peptides found in protein C but not in protein D. The results suggest that VPg is derived by cleavage of protein C and that protein H may be intermediate. Preliminary experiments with VPg sequences in polioviral noncapsid protein 1b, the counterpart of encephalomyocarditis viral protein C, were inconclusive.

Encephalomyocarditis virus↗
PubMed1977

The 5'-terminal structures of poliovirion RNA and poliovirus mRNA differ only in the genome-linked protein VPg.

The 5'-terminal, RNase T1-resistant oligonucleotide of poliovirus mRNA has been isolated. Its sequence is pU-U-A-A-A-A-C-A-Gp, which is identical to that of virion RNA except that the genome-linked protein VPg is absent [Nomoto, A., Detjen, B., Pozzatti, R. & Wimmer, E. (1977) Nature 268, 208-213]. Because all newly synthesized viral RNAs are VPg-linked, we propose that VPg is cleaved from progeny RNA at the linkage between protein and nucleic acid prior to polyribosome formation. This may represent a new mode of processing of viral macromolecules. Virion RNA from which VPg has been cleaved proteolytically retains its specific infectivity, an observation suggesting that VPg is not involved in early steps (penetration and translation) of the infectious cycle initiated by RNA.

Base Sequence↗
PubMed1976

Competition between cellular and viral mRNAs in vitro is regulated by a messenger discriminatory initiation factor.

Encephalomyocarditis viral RNA has previously been shown to outcompete host cellular mRNA has for translation in vitro in crude and fractionated protein synthesizing systems. In the present communication it is shown that the competition is regulated by an initiation factor or complex of factors, and not the 40S initiation complex per se. The factor primarily involved is the murine equivalent of a component present in a partially purified preparation of rabbit initiation factor M3. Both the murine and rabbit factors are clearly messenger discriminatory.

Animals↗
PubMed1974

The mechanism of viral replication. Structure of replication complexes of encephalomyocarditis virus.

The structure of the purified replicative intermediate of encephalomyocarditis virus was determined by electron microscopy. Approximately 80% of the replicative intermediate complexes were characterized by a filament of double-stranded RNA of widely variable length, which had a "bush" of single-stranded RNA at one end. In many examples one or more additional single-stranded bushes were appended internally to the double-stranded RNA filament. These results support the view that before deproteinization, replicative intermediate contains little if any double-stranded RNA.

Centrifugation, Density Gradient↗
PubMed1970

A new protein synthesis factor from Escherichia coli.

A new factor that effects protein synthesis by Escherichia coli extracts was partially purified from the 1 M NH(4)Cl wash of E. coli ribosomes. This factor stimulates the binding of aminoacyl-tRNA to 30S ribosomes, and it increases the rate of synthesis of polyphenylalanine in the presence of 30S and 50S subunits.

Bacterial Proteins↗