Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Packaging”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources
PubMed1983

Construction of a retrovirus packaging mutant and its use to produce helper-free defective retrovirus.

A mutant of Moloney murine leukemia virus (M-MuLV), pMOV-psi-, was constructed by deletion of about 350 nucleotides from an infectious proviral DNA clone between the putative env mRNA 5' splice site and the AUG that initiates the coding sequence for Pr65gag. Although the parent wild-type proviral clone, pMOV-psi+, quickly causes a high level of reverse-transcriptase-containing virus particles to be released from transfected NIH/3T3 cells, transfection of pMOV-psi- into these cells initially results in very little release. By 9 to 10 days after transfection, however, pMOV-psi- -transfected cells produce infectious virus. Thus pMOV-psi- has a defect that can be repaired in transfected NIH/3T3 cells, presumably by recombination with a sequence normally present in the cells. Cell lines with pMOV-psi- stably integrated into chromosomal DNA produce reverse-transcriptase-containing particles that lack detectable M-MuLV RNA but the cells efficiently complement replication-defective, packagable retroviruses. Thus pMOV-psi- has a defect in the packaging of genomic RNA into virions but can provide in trans the products necessary for virion production. The deletion in pMOV-psi- appears to define a site required in cis for packaging of MuLV RNA into virions. Cell lines carrying pMOV-psi- can be used to produce helper-free stocks of natural or synthetic defective retroviruses.

Chromosome Deletion↗
PubMed1985

Evidence that a phage T4 DNA packaging enzyme is a processed form of the major capsid gene product.

A phage T4 DNA packaging enzyme appears to arise as a processed form of the major T4 capsid structural protein gp23. The enzyme activity and antigen are missing from all head gene mutants that block the morphogenetic proteolytic processing reactions of the head proteins in vivo. The enzyme antigen can be formed in vitro by T4 (gp21) specific processing of gp23 containing extracts. Enzyme antigen is found in active processed proheads but not in full heads. The enzyme and the major capsid protein show immunological cross-reactivity, produce common peptides upon proteolysis, and share an assembly-conformation-dependent ATP binding site. The packaging enzyme and the mature capsid protein (gp23*) both appear to arise from processing of gp23, the former as a minor product of a specific gp23 structure in the prohead, acting in DNA packaging as a DNA-dependent ATPase, and a headful-dependent terminase.

Adenosine Triphosphatases↗
PubMed1986

Synthesis of bacteriophage phi X174 in vitro: mechanism of switch from DNA replication to DNA packaging.

Replication of a replicative form DNA of bacteriophage phi X174 initiates by rolling-circle synthesis of the viral DNA followed by discontinuous synthesis of the complementary DNA. Gene C protein of phi X174, which is involved in DNA packaging, inhibits the rolling-circle DNA synthesis by binding to the initiation complex in vitro. The gene C protein-associated initiation complex can synthesize and package the viral DNA to produce infectious phage when supplemented with phi X174 gene J protein and the prohead. Multiple rounds of phage synthesis occur without dissociation of the gene C protein from the complex. These results indicate that gene C protein is central in the switch from replication of a replicative form DNA to synthesis and concomitant packaging of viral DNA into phage capsid, which occurs in the late stage of infection.

Bacteriophage phi X 174↗
PubMed1989

Comparison of pregnancy rates achieved with frozen semen using two packaging methods.

The pregnancy rate achieved with frozen semen using two packaging methods was compared in two separate experiments. The sperm-rich fraction of the semen was collected and immediately extended in an egg-yolk based extender to a final concentration of 100 x 10(6) sperm/ml. Half of each ejaculate was packaged in 4.0-ml plastic straws and the other half in 10-to 12-ml flattened aluminum tubes. After detection of a 35-mm follicle, mares were inseminated daily until ovulation. Pregnancy was detected, and embryonic vesicle size was measured by ultrasonic echography Days 14 to 26 after ovulation. The one-cycle pregnancy rate achieved using both packaging methods was 50% overall (23 46 ), with 46% (12 26 ) and 55% (11 20 ) rates achieved, respectively, using straws and aluminum tubes. These rates were not significantly different.

Journal Article↗
PubMed1990

Endothelial cell response to polyvinyl chloride-packaged GORETEX: effect of surface contamination.

A Fourier transform infrared spectroscopic study of polyvinyl chloride packaged GORETEX vascular prostheses indicated that their internal and external surfaces were coated with an additive layer presumed to be derived from the polyvinyl chloride packaging. This layer was not removed by washing in phosphate buffered saline but was soluble in trimethyl pentane and hexane. Some other treatments of GORETEX and the packaging were shown to remove the contaminant from the surface and this correlated with an inferior in vitro aortic endothelial cell response. Analyses of materials extracted from both the polyvinyl chloride and the GORETEX surface indicated that the major surface component was a long chain aliphatic ester, either a plasticizer or a lubricant constituent.

Animals↗
PubMed1990

Irradiation of pre-packaged sliced cooked meat products with low and normal sodium content.

Irradiation experiments were carried out with pre-packaged sliced cooked meat products with different initial counts of Enterobacteriaceae and mesophilic aerobic bacteria. In low-sodium meat products Enterobacteriaceae could effectively be inactivated in refrigerated or frozen products by irradiation with a dose of 1 or 2 kGy respectively, provided the number of these bacteria was below 10(3) to 10(4) per g. The low-sodium meat products involved endured above treatment without being seriously affected as to sensory qualities. Shelf-life of salted cooked meat products could be prolonged by irradiating the frozen product. Irradiation with a dose of 2 kGy enabled uncooled storage of the product for a restricted period (5-7 days). Best results were obtained for meat products with a salt content in the brine phase of greater than 4.0% (w/w) and having a good hygienic quality, i.e. an initial bacterial count below 10(4)/g. Packaging in a gas atmosphere (CO2) slightly enhanced protection as compared to vacuum packaging. Off-flavours as a result of irradiation of salted cooked meat products varied from slight to strong and depended on the type of product.

Animals↗
PubMed1990

Growth and toxigenesis of C. botulinum type E in fishes packaged under modified atmospheres.

Modified atmosphere packaging of fresh fish is used to market high quality products in some European countries. The potential risk of C. botulinum growth in these extended shelf-life foods is still a concern; especially since toxigenesis may precede organoleptic spoilage. This paper will present toxigenic data from rockfish, salmon and sole muscle tissues which were inoculated with a pool of non-proteolytic C. botulinum type E at seven levels (10(-2)-10(4) spores/sample), and stored under vacuum and 100% CO2, at incubation temperatures between 30 and 4 degrees C, for up to 60 days. Factorial experimental design allowed predictive formulae to be developed able to describe the lag time prior to C. botulinum toxigenesis and the probability of one spore to initiate toxigenesis based upon the storage conditions. Accurate characterization of the microbial ecology of C. botulinum in modified atmosphere-packaged fish, will support safe exploitation of these packaging systems in the market place, and identify critical control points for potential product or process abuses.

Animals↗
PubMed1996

Thermotolerance of meat spoilage lactic acid bacteria and their inactivation in vacuum-packaged vienna sausages.

Heat resistance of three meat spoilage lactic acid bacteria was determined in vitro. D-values at 57, 60 and 63 degrees C were 52.9, 39.3 and 32.5 s for Lactobacillus sake, 34.9, 31.3 and 20.2 s for Leuconostoc mesenteroides and 22.5, 15.6 and 14.4 s for Lactobacillus curvatus, respectively. The three lactic acid bacteria were heat sensitive, as one log reductions in numbers were achieved at 57 degrees C in less than 60 s. Z-values could not be accurately determined as D-values did not change by a factor of 10 over the temperature range studied. In-package pasteurization processes were calculated using the highest in vitro D-value and applied to vacuum-packaged vienna sausages. Microbiological shelf life (time for lactic acid bacteria count to reach 5 x 10(6) CFU/g) increased from 7 days for non-pasteurized samples to 67, 99 and 119 days for samples of the three pasteurization treatments at 8 degrees C storage. Enterobacteriaceae were detected at levels of log 4.0 CFU/g in non-pasteurized samples, but were reduced to < log 1.0 CFU/g in pasteurized samples. The incidence of listeriae in non-pasteurized samples was low as only one Listeria innocua strain was isolated. No Listeria spp. were isolated from pasteurized samples. Numbers of Clostridium isolates increased from one in non-pasteurized samples to 25 in pasteurized samples. Increasing incidences of clostridia, and the presence of C. perfringens in pasteurized samples indicated that in-package pasteurization could compromise product safety.

Clostridium↗
PubMed1986

Plasmid pKUN9, a versatile vector for the selective packaging of both DNA strands into single-stranded DNA-containing phage-like particles.

A versatile vector plasmid, pKUN9, has been constructed which, simply by infecting cells harboring this plasmid with either bacteriophage IKe or Ff (M13, fd, and fl), permits the selective packaging of both of its DNA strands into, single-stranded (ss) DNA-containing, phage-like particles. The plasmid, which is a derivative of plasmid pUC9 [Vieira and Messing, Gene 19 (1982) 269-276], contains in opposite orientations the replication origins and contiguous packaging signals of the distantly related filamentous phages IKe and Ff. As a result of the selective packaging, both strands of a DNA fragment cloned in pKUN9 can be obtained in a single-stranded form and can be sequenced by the dideoxy method using commercially available (+) and (-) sequencing primers. In addition, plasmid pKUN9 possesses all unique properties incorporated in the M13mp phages and the pUC plasmids.

Base Sequence↗
PubMed1990

A phosphate group at the cos ends of phage lambda DNA is not a prerequisite for in vitro packaging: an alternative method for constructing genomic libraries using a new phasmid vector, lambda pGY97.

It is shown here that the phosphate groups at the cos ends of phage lambda DNA are not a prerequisite for in vitro packaging. Molecules with phosphatase-treated cos ends are packaged in vitro as efficiently as native lambda DNA. This observation can be used for an alternative strategy to improve the efficiency of gene library construction, since cos-cos ligation decreases in vitro encapsidation and infectivity. Dephosphorylated cos ends and a new phasmid vector lambda pGY97 have been used to construct a representative gene bank of alfalfa in a Mcr- (5-methylcytosine restriction deficient) Escherichia coli host strain. These recombinant clones can be propagated as phages or more conveniently as plasmids in recA- E. coli, to prevent possible homologous recombination events between repetitive sequences of the insert that would otherwise interfere with clone stability. The 5-19-kb inserts can be easily recloned as plasmids from the recombinant phasmids with simple EcoRI digestion and re-ligation. This observation also implies that the construction of gene libraries in cosmid vectors can be made more efficient if cos-cos ligates were cleaved by lambda terminase just before in vitro packaging.

Bacteriophage lambda↗
PubMed1993

An expression-packaging-processing vector which selects and maintains 7-kb DNA inserts in the blue T4 phage genome.

We have developed an efficient positive-selection vector to insert foreign DNA segments fused to the T4 ipIII gene (encoding internal protein IPIII) into the bacteriophage T4 genome. By using partial deletions of the T4 e gene, which encodes phage lysozyme, lysozyme activity required for plaque formation is used to select plasmid integrants which restore the e gene. In this work, we demonstrate that DNA inserts more than 7.0 kb in length can be incorporated into a T4 genome lacking the alt gene. In addition, the recombinant T4 not only contains a fusion gene driven by the T4 ipIII promoters, but also packages the fusion protein into the T4 capsid due to targeting by the IPIII portion. This expression-packaging-processing system shows that active IPIII::beta Gal fusion reporter protein is produced and packaged during phage infection.

Bacteriophage T4↗
PubMed1987

Increasing positive social interactions by handicapped individuals during a recreational activity using a multicomponent treatment package.

A multicomponent treatment package increased the rate of positive statements among handicapped youth during a social/leisure activity at a work training setting. The package of role playing, graphic feedback, contingent reinforcement, and self-monitoring was directly replicated across three experiments in producing normative rates of positive verbal statements. There was no evidence of generalization to other stimulus activities. There was limited response generalization to a class of negative verbal statements. The study further examined the critical components of the maintenance package through a withdrawal design. It was found that contingent reinforcement and self-monitoring could maintain substantial rates of positive behaviors. In the third experiment it was further demonstrated that self-monitoring alone could maintain positive statements in three of the four students in the group.

Adolescent↗
PubMedDate not supplied

Component analysis and stimulus control assessment of a behavior deceleration treatment package.

A treatment package that included two setting condition manipulations and visual occlusion was implemented to gain control over the high-intensity screaming and whining of a 16-year-old female with developmental disabilities. The study included an analysis of the individual and combined components of the treatment package and a stimulus control analysis of three salient features of the visual occlusion apparatus (i.e., opaque screen, secured helmet, and cranial pressure). Results showed that the treatment package occasioned a deceleration in the two targeted vocal behaviors and a reduction in the amount of time the participant was required to wear the occlusion apparatus. An analysis of the apparatus suggested that the critical element needed to control inappropriate vocalizations appeared to be cranial pressure, which was naturally produced by the helmet. Consequently, the helmet was eliminated and cranial pressure was produced by a woman's headband. Follow-up data, collected 1, 2, and 3 months after termination of systematic intervention, revealed near-zero levels of screaming and whining behaviors. A 9-month follow-up investigation involving the removal and subsequent reinstatement of the headband procedure supported the use of the headband for the maintenance of behavioral gains.

Adolescent↗
PubMedDate not supplied

Analyze: a comprehensive, operator-interactive software package for multidimensional medical image display and analysis.

A comprehensive software package, called ANALYZE, has been developed (1) which permits detailed investigation and evaluation of multidimensional biomedical images. ANALYZE can be used with 3-D imaging modalities based on x-ray computed tomography, radionuclide emission tomography, ultrasound tomography, and magnetic resonance imaging. The software is written entirely in "C" and runs on standard UNIX workstations. The ANALYZE package features integrated, complimentary tools for fully interactive display, manipulation and measurement of multidimensional image data. The software architecture permits systematic enhancements and upgrades which has fostered development of a readily expandable package. It provides an effective shell for custom software prototyping and turnkey applications. This paper provides a general description of this software as well as specific details on the methodology employed to develop it, both conceptual and technical. Applications of the software are illustrated.

Image Processing, Computer-Assisted↗
PubMed2004

CDtool-an integrated software package for circular dichroism spectroscopic data processing, analysis, and archiving.

CDtool is a software package written to facilitate circular dichroism (CD) spectroscopic studies on both conventional lab-based instruments and synchrotron beamlines. It takes format-independent input data from any type of CD instrument, enables a wide range of standard and advanced processing methods, and, in a single user-friendly graphics-based package, takes raw data through the entire processing procedure and, importantly, uses data-mining techniques to retain in the final output all the information associated with the processing. It permits the facile comparison of data obtained from different instruments without the need for reformatting and displays it in graphical formats suitable for publication. It also includes the ability to automatically archive the processed data. This latter feature may be especially useful in light of recent funding institution directives with regard to data sharing and archiving and requirements for "good practice" and "traceability" within the pharmaceutical industry. In addition, CDtool includes a means of interfacing with protein data bank coordinate files and calculating secondary structures from them using alternate definitions and algorithms. This feature, along with a function that permits the facile production of new reference databases, enables the creation of specialized databases for secondary structural analyses of specific types of proteins. Thus the CDtool software not only enables rapid data processing and analyses but also includes many enhanced features not available in other CD data processing/analysis packages.

Archives↗
PubMed2005

The role of an over-the-counter vaginal pH self-test device package insert: can subjects learn what the device is for and how to use it?

OBJECTIVE: This study was undertaken to determine whether subjects could read and understand the package insert of a vaginal pH self-test device to improve self-diagnostic accuracy. STUDY DESIGN: This study was performed at 8 clinic locations with 206 women of varying ages, ethnicity, and education. A package insert explaining the indications and clinical facts associated with the use of a vaginal pH self-test device was used. A 16-item questionnaire was administered to assess comprehension. RESULTS: The cumulative probability of having 12 or more correct answers of 16 was P = .038, significantly different than by chance alone, representing 200 (97.1%) of subjects in this trial. CONCLUSION: The package insert for the vaginal pH self-test device was read and understood by subjects. Indeed, they correctly understood the role of vaginal pH as an aid in the diagnosis of vaginal symptoms while improving decisions to use an over-the-counter antifungal medication or to see a health care provider.

Adolescent↗
PubMed2004

Specificity of neomycin analogues bound to the packaging region of human immunodeficiency virus type 1 RNA.

The packaging region of HIV-1 RNA contains a number of structural features which are important in the life cycle of the virus, making this segment of RNA a potential target for new types of AIDS-directed drugs. We studied the binding of three neomycin analogues (neo-guanidino, neo-acridine, and neo-neo) to a 171-mer RNA molecule from the packaging region of HIV-1 using quantitative footprinting and circular dichroism. Neo-guanidino produced footprinting patterns and effects on the CD similar to those observed for neomycin and paromomycin, indicating that all three compounds bind to the same regions of the 171-mer. Neo-guanidino binds to SL 1 where it joins the large internal loop, near a bulge in the stem of SL 1, and on SL 2. Neo-acridine, which has an acridine attached to neomycin, and neo-neo, which has two neomycins linked by a flexible tether, bind bivalently, and give very different footprinting and CD results from the other compounds. The neomycin portion of neo-acridine binds to the same sites as neomycin, while the attached acridine group appears to bind to a duplex region in the main stem of the folded 171-mer. Since the footprinting data for this analogue show few enhancements, bivalent binding of neo-acridine appears to stabilize the folded structure of RNA by effectively 'stapling' parts of the structure together. Neo-neo induces significant structural changes in RNA where neomycin binds. This may be related to the inability of both neomycins of neo-neo it find optimal binding sites adjacent to one another without changing RNA structure. The intensity of a strong negative CD band in the spectrum of psi-RNA at 208 nm is sensitive to drug-induced changes in RNA structure. Neo-guanidino and neo-neo (also neomycin and paromomycin), which change RNA structure, cause an increase in intensity while neo-acridine, which induces little distortion to RNA, causes a decrease in intensity. Molecular modeling analysis shows that C-5' of ribose of neo-acridine and neo-neo must be directed away from the binding pocket when these analogues are bivalently bound to RNA. This study showed how variations in the structure of aminoglycosides lead to different binding specificity to part of the packaging region of HIV-1. Such knowledge will be important in design of drugs to target this region.

Base Sequence↗
PubMed2004

Atomic snapshots of an RNA packaging motor reveal conformational changes linking ATP hydrolysis to RNA translocation.

Many viruses package their genome into preformed capsids using packaging motors powered by the hydrolysis of ATP. The hexameric ATPase P4 of dsRNA bacteriophage phi12, located at the vertices of the icosahedral capsid, is such a packaging motor. We have captured crystallographic structures of P4 for all the key points along the catalytic pathway, including apo, substrate analog bound, and product bound. Substrate and product binding have been observed as both binary complexes and ternary complexes with divalent cations. These structures reveal large movements of the putative RNA binding loop, which are coupled with nucleotide binding and hydrolysis, indicating how ATP hydrolysis drives RNA translocation through cooperative conformational changes. Two distinct conformations of bound nucleotide triphosphate suggest how hydrolysis is activated by RNA binding. This provides a model for chemomechanical coupling for a prototype of the large family of hexameric helicases and oligonucleotide translocating enzymes.

Adenosine Triphosphatases↗