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Results for “Processing factor”

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PubMed1990

[The principles of the combined and simultaneous action of industrial factors].

The laws of the development of tension of the main systems and regulatory mechanisms of the organism of people working both under exposure to occupational factors altogether and to various combinations of ergometric indices of work. Joint action of unfavourable labour conditions (dust, industrial noise, insufficient lighting) and of working process factors (local muscular stress, hardness and tension of labour), as a rule, cause potentiation of unfavourable changes in the functional status of the organism. In the majority of occupational groups the factors studied predetermine in 76-96% of cases changes in the functional state of the major systems of the workers' organism.

Humans↗

PubMed1990

Quality assurance for psychiatric emergencies. An analysis of assessment and feedback methodologies.

Improvement in the quality of evaluation and treatment of behavioral emergencies presenting to hospital emergency rooms requires a multicomponent assessment of resources, clinician performance, and outcome. The authors present a summary of data and conclusions derived from index-based assessment of quality of care in over 2000 psychiatric emergencies. The study revealed that emergency room physicians rendered high-quality medical care, but were deficient in crucial aspects of psychiatric evaluation and treatment including evaluation of dangerousness and substance abuse and provision of appropriate follow-up care. A positive association was observed between quality of care and compliance with referral. Subsequent review with the staff pointed to issues such as staffing, emergency room and community resources, and adequacy of documentation as significant influences on quality of care, as assessed by the chart-audit, index approach. A pilot study demonstrated uniform improvement of quality scores in a small group of physicians receiving written and oral feedback about their performance. The use of focused quality assessment studies that examine both structural and process factors, and their correlation with outcome, is discussed in light of the information obtained from the previously described study. A feedback methodology that emphasizes an interactive process to identify deficiencies in care and to explore their causes and remedies is presented.

Aftercare↗

PubMed1991

Unmet service needs in methadone maintenance.

Most drug abuse treatment agencies maintain a wide array of ancillary services, either on-site or through off-site referral resources, for helping meet the diverse social, medical, and psychological needs of clients. The extent to which these needs are met may be an important factor in client retention and outcomes. Perceived unmet service needs and their relationship to client outcomes were therefore studied in relationship to a framework for studying drug abuse treatment process factors. The outcomes in the present study were time in treatment and relapse to opioid use during treatment, and these were examined in relation to perceived need for services and their delivery (whether or not these services were received). The sample consisted of 590 methadone maintenance clients in 21 clinics in the RTI/TOPS data system. The results showed that the measure of unmet needs for services was not significantly related to time to relapse or to time in treatment. However, there appeared to be an indirect effect. There were differences for clinic type and a few significant interactions with other predictor variables used to study treatment process.

Combined Modality Therapy↗

PubMedDate not supplied

Comprehension of temporal terms by good and poor readers.

Poor beginning readers often have difficulty comprehending spoken sentences with complex syntactic structures. This study attempts to identify the reasons for this difficulty. Second-grade good and poor readers were tested for comprehension of spoken sentences containing the temporal terms before and after. Processing load was varied systematically while holding syntax constant in an effort to determine whether processing factors contribute to poor readers' comprehension problems, or whether poor readers are simply lacking the structural knowledge required to understand sentences containing temporal terms. The poor readers' high level of performance under conditions of reduced processing demands suggests that their misinterpretations in spoken language understanding may be due, in large part, to limitations in verbal working memory.

Attention↗

PubMed1992

Varied poly(A) site efficiency in the adenovirus major late transcription unit.

Regulation of adenovirus major late transcription unit (MLTU) mRNA biosynthesis involves poly(A) site selection between five available sites, L1 through L5. The 5' proximal site completely dominates during early infection, whereas all five sites are used during late infection with L3 being favored slightly over the others. Previous studies have shown this early to late poly(A) switch will occur in the absence of MLTU-specific splicing patterns and hinges in large part on the character of the first poly(A) site. We have used in vitro assays to characterize basic features of the L1 and L3 pre-mRNAs which may help define how processing at poly(A) sites is controlled. We have found that L1 is 5-10-fold less efficient than L3 as a substrate for RNA cleavage. A primary difference between the L1 and L3 sites lies in the kinetics of their use, with cleavage at L3 occurring at twice the rate of cleavage at L1. In addition, L1 is 20-fold less effective than L3 in competing for processing factors. To investigate the sequence elements that contribute to poly(A) site efficiency, we have used competition assays in which the competitor RNAs lack upstream or downstream elements.

DNA-Binding Proteins↗

PubMed1991

Fish meal as a protein supplement in ruminant diets: a review.

Fish meal (FM) as a protein supplement in ruminant diets is presented to illustrate production responses to FM supplementation and to explain the possible factors that may affect the magnitude of these responses. Positive responses are consistently detected when FM is fed to nonruminants, but the responses when fed to ruminants have lacked consistency. Research indicates that ruminal protein degradation of FM is affected by processing factors including type and freshness of fish, addition of preservatives, stabilization of fat, type of dryer used, temperature and duration of heating, and the amount of fish solubles added back to the meal. Performance data published in the last two decades have been categorized into body weight gain and milk yield and composition. Fish meal was more effective in improving body weight gain in young than in finishing ruminants and in males than in females or castrated males. Daily gains and feed efficiencies were higher when FM supplemented medium- or poor-quality silages than when it was added to high-quality silages. No significant advantage was found for replacing protein sources that were highly ruminally degradable with FM in high-corn diets fed to growing ruminants. Milk yield and milk protein concentration were improved by FM supplementation of low-concentrate diets fed to cows in early lactation. However, milk fat percentage was negatively affected by FM supplementation. Reproduction data indicated that body gain and conception rates of high-producing cows were improved by supplementing their diets with FM during early lactation. Results suggest a significant advantage of FM supplementation to ruminant diets if the physiological status of the animal and the quality of the dietary ingredients are taken into account.

Animal Feed↗

PubMed1991

Complex factors in hydrocarbon/water, soil/water and fish/water partitioning.

Many partitioning and toxicological events that appear to correlate simply with log P (octanol/water) can be resolved into greater detail by a factoring process. Log P can be separated into lipophilic (PL) and hydrophilic (PH) contributions that combine well with polarizability (MR) and hydrogen-bonding (HB) to describe partitioning and non-specific binding in phases that differ greatly from n-octanol. In addition, hydrogen-bonding can be factored into donor groups (HBD) and acceptor groups (HBA) for stronger correlations and greater mechanistic insight. These descriptors are applied to a variety of problems in simple partitioning, soil organic matter binding, bioaccumulation in fish, and aquatic narcosis and toxicity.

Animals↗

PubMed1991

Proper and improper folding of proteins in the cellular environment.

Protein folding in the cellular environment involves an interplay between the intrinsic biophysical properties of a protein, in both its folded and unfolded states, and various accessory proteins that aid the process. Factors such as peptidyl prolyl isomerase, protein disulfide isomerase, thioredoxin, and SecB may interact with the unfolded forms of specific classes of proteins, while members of the hsp70/DnaK and hsp60/GroEL molecular chaperone families may play a more general role in folding. Secretion, proteolysis, and aggregation are other in vivo processes that depend greatly on the folding behavior of a given protein. Intrinsic folding rates, or even translation rates, of nascent proteins may be optimized by natural selection to ensure smooth coordination with all the cellular components required for a successful folding reaction.

Bacterial Proteins↗

PubMed2025

The RNA splicing factor PRPF8 is required for left-right organiser cilia differentiation and determination of cardiac left-right asymmetry via regulation of Arl13b splicing.

Cilia function in the left-right organizer (LRO) is critical for determining internal organ asymmetry in vertebrates. To further understand the genetics of left-right asymmetry, we isolated a mouse mutant with laterality defects, l11Jus27, from a random mutagenesis screen. l11Jus27 mutants carry a missense mutation in the pre-mRNA processing factor, Prpf8. cephalophŏnus (cph) mutant zebrafish, carrying a protein truncating mutation in prpf8, phenocopy the laterality defects of l11Jus27 mutants. Prpf8 mutant mouse and fish embryos have increased expression of an alternative transcript encoding the cilium-associated protein, ARL13B, that lacks exon 9. In zebrafish, over-expression of the arl13b transcript lacking exon 9 perturbed cilium formation and caused laterality defects. The shorter ARL13B protein isoform lacked interactions with intraflagellar transport proteins. Our data suggest that PRPF8 plays a prominent role in LRO cilia by through the regulation of alternative splicing of ARL13B, thus uncovering a new mechanism for cilia-linked developmental defects.

ARL13B↗

PubMed1992

Arginine specific endopeptidases modify the aggregation properties of a synthetic peptide derived from Alzheimer beta/A4 amyloid.

A synthetic peptide corresponding to the first 28 amino acids of the Alzheimer disease amyloid beta/A4 peptide (3.2 kDa) aggregated to a high molecular weight (15 kDa) on SDS/urea polyacrylamide gels. Proteinase K, V8 protease, trypsin, and endopeptidase Lys-C readily degraded the aggregate. By contrast, when digested by endopeptidase Arg-C, a new polypeptide aggregate of higher molecular weight (16 kDa) was observed on denaturing gels without degraded smaller products. The new aggregate was comprised of three peptides: an intact beta/A4(1-28) and partially degraded peptides beta/A4(1-5) plus beta/A4(6-28). The results were confirmed by treatment of beta/A4 with other arginine-specific proteases: the gamma subunit of nerve growth factor and clostripain. The results indicate that arginine-specific proteases, including a growth factor processing enzyme, can nick aggregated beta/A4(1-28) amyloid and alter the configuration to produce a more complex aggregated form. If similar highly specific proteolytic mechanisms occur in the Alzheimer disease brain, the processing may promote the formation of high molecular weight aggregates that contribute to the development of relatively insoluble senile plaque core protein.

Alzheimer Disease↗

PubMed1990

In vitro polyadenylation is stimulated by the presence of an upstream intron.

The majority of vertebrate pre-mRNAs are both spliced and polyadenylated. To investigate the mechanism whereby processing factors recognize last exons containing both splicing and polyadenylation consensus elements, chimeric precursor RNAs containing a single intron and a poly(A) site were constructed and assayed for in vitro splicing and polyadenylation. Chimeric RNAs underwent splicing and polyadenylation. Both reactions occurred in a single RNA. The presence of an intron enhanced the rate of polyadenylation at a downstream poly(A) site. The extent of stimulation varied from two- to fivefold, depending on the magnesium concentration. Maximal stimulation of polyadenylation by an upstream intron required a 3' splice site but not a 5' splice site, suggesting that the structure of the terminal exon was more important than the presence of a complete upstream intron. We suggest that splicing and polyadenylation factors interact to recognize terminal, poly(A) site-containing exons. Such interaction may explain why all known intron-containing eukaryotic pre-mRNAs generate their 3' ends by polyadenylation.

Base Sequence↗

PubMed2024

STAG2 loss in Ewing sarcoma alters enhancer-promoter contacts dependent and independent of EWS::FLI1.

Cohesin complexes carrying STAG1 or STAG2 organize the genome into chromatin loops. STAG2 loss-of-function mutations promote metastasis in Ewing sarcoma, a pediatric cancer driven by the fusion transcription factor EWS::FLI1. We integrated transcriptomic data from patients and cellular models to identify a STAG2-dependent gene signature associated with worse prognosis. Subsequent genomic profiling and high-resolution chromatin interaction data from Capture Hi-C indicated that cohesin-STAG2 facilitates communication between EWS::FLI1-bound long GGAA repeats, presumably acting as neoenhancers, and their target promoters. Changes in CTCF-dependent chromatin contacts involving signature genes, unrelated to EWS::FLI1 binding, were also identified. STAG1 is unable to compensate for STAG2 loss and chromatin-bound cohesin is severely decreased, while levels of the processivity factor NIPBL remain unchanged, likely affecting DNA looping dynamics. These results illuminate how STAG2 loss modifies the chromatin interactome of Ewing sarcoma cells and provide a list of potential biomarkers and therapeutic targets.

Sarcoma, Ewing↗

PubMed1989

Regulation of poly(A) site selection in adenovirus.

We have investigated the mechanisms involved in the early-to-late RNA-processing switch which regulates the mRNA species generated from the adenovirus major late transcription unit (MLTU). In particular, polyadenylation choice mechanisms were characterized by using a reconstructed adenovirus E1A gene as a site for insertion of MLTU poly(A) regulation signals (L1 and L3). Adenovirus constructs containing the variant poly(A) recognition elements were used to compare E1A poly(A) signal utilization with wild-type MLTU (L1 to L5) utilization. In both early and late stages of infection, either polyadenylation site (L1 or L3) is capable of being utilized when presented as the only operational poly(A) site. In an early infection, a virus which contains multiple elements presented in tandem (L13) uses the first poly(A) site, L1, preferentially (ratio of L1 to L3, 8:1) in both E1A and MLTU loci. Transcription termination is not involved in restricting the utilization of the downstream L3 site. In a late infection, when each of the five MLTU poly(A) sites is used, a switch also occurs for the E1AL13 construct, with utilization of both the L1 and L3 poly(A) sites. The switch from early to late was not the result of altered processing factors in the late infection, as demonstrated by superinfecting the E1AL13 construct into cells which had already entered a late stage of infection. The superinfecting virus gave an L1-only phenotype; therefore, a cis mechanism is involved in adenovirus poly(A) regulation.

Adenoviridae↗

PubMed2026

Comprehensive study on pesticide residues and mycotoxins in freeze-dried strawberries and raspberries.

Freeze-dried fruit has gained popularity because it preserves the flavour and nutritional value of fresh fruit while providing extended shelf life. Despite this, there are concerns regarding its chemical safety. This study evaluated 58 freeze-dried fruit products from the Czech retail market, focusing on potential contamination. Pesticide residues and mycotoxins were determined using LC-MS/MS and GC-MS/MS. Overall, 111 pesticide residues (or their metabolites) and 3 mycotoxins were quantified. After applying processing factors, 12 pesticide residues exceeded EU maximum residue limits. Prohibited substances, including carbofuran, omethoate, and haloxyfop, were detected. Tenuazonic acid was found in 71% of samples, while alternariol and tentoxin were detected less frequently. More than half (54%) of strawberry samples contained 10 or more pesticide residues, indicating potential cumulative exposure concerns, particularly for children with lower body weight. These findings highlight the need for continued monitoring of freeze-dried fruits and further assessment of dietary exposure.

Pesticide Residues↗

PubMedDate not supplied

Measurement of protein-DNA interaction parameters by electrophoresis mobility shift assay.

Native gel electrophoresis (mobility shift) assays may be used to obtain quantitative information about the site distribution, equilibria and kinetics of protein-DNA interactions. These applications depend on the ability of the electrophoretic system to resolve the reaction components, and on their stabilities during the separation process. Factors which affect the lifetimes and mobilities of protein-DNA complexes during electrophoresis include reaction and electrophoresis buffer composition, pH, and ionic strength; the presence of low molecular weight effectors and enzymatic substrates; the nature and concentration of the gel matrix; the temperature; the molecular weights of protein and DNA; the stoichiometric ratios of their complexes; and the possibility of conformational and configurational isomerization of reaction components. We discuss how these factors influence the acquisition of quantitative data from electrophoretic patterns and band intensities, and present formulas for the estimation of equilibrium constants and rate constants for prototypical DNA-protein interactions.

Binding, Competitive↗

PubMed1990

Observing interactions of abusive and nonabusive dyads: information extracted by accurate and inaccurate judges.

This study describes the reported observations of protective services workers who varied in the accuracy with which they could discriminate abusive from nonabusive mother-child interactions. Participants viewed videotapes of two abusive and two nonabusive dyads. They noted behaviors that suggested an abusive history and behaviors that suggested a nonabusive history for each dyad. Comparisons of more and less accurate judges indicated that accurate judges observed more evidence for abuse when the dyad actually was abusive. The informational advantage of experts was not limited to detecting interactional difficulties in abusive dyads; they also reported observations of more favorable behaviors of nonabusive dyads. Highly accurate judges were more likely to observe communication patterns, task-oriented behavior, and other-directed behaviors than were less accurate judges. These findings suggest that specific information-processing factors may vary with clinical expertise.

Child↗

PubMed1991

An apparent pause site in the transcription unit of the rabbit alpha-globin gene.

Transcription of the rabbit alpha-globin gene begins primarily at the cap site, although some upstream start sites are also observed. Analysis by RNA polymerase run-on assays in nuclei shows that transcription continues at a high level past the polyadenylation site, after which the polymerase density actually increases in a region of about 400 nucleotides, followed by a gradual decline over the 700 nucleotides. These features are also observed in the transcription unit of the rabbit beta-globin gene. The region with the unexpectedly high nascent RNA hybridization signal in the 3' flank contains a conserved sequence, KGCAGCWGGR (K = G or T, W = A or T, R = A or G), followed by an inverted repeat. The inverted repeat (perhaps with the conserved sequence) may be a pause site for RNA polymerase II, thus accounting for the increase in polymerase density. This sequence and inverted repeat are found in the 3' flank of several globin genes and the simian virus 40 (SV40) early genes, as well as in the regions implicated in pausing or termination of transcription of eight different genes. Deletion of the conserved sequence and inverted repeat from the 3' flank of the SV40 early region causes a small increase in the levels of transcription downstream from this site. Replacement with the conserved sequence and inverted repeat from the rabbit alpha-globin gene causes an accumulation of polymerases, supporting the hypothesis that polymerases pause at this site. This proposed pause site may affect the efficiency of termination at some sites further downstream, perhaps by loss of a processivity factor.

Amino Acid Sequence↗

PubMed2025

BET family BRD3 initiates DSB-induced chromatin remodeling with TIP60 to promote R-loop-mediated HR.

Mechanisms for genome stability in actively transcribed regions are essential for cellular homeostasis; however, these mechanisms are poorly understood. Herein, we identify the bromodomain and extraterminal domain (BET) family BRD3 as the genome caretaker in actively transcribed chromatin. We identify the protein network between BRD3 and chromatin remodeler TIP60. During transcription, BRD3 localizes to actively transcribed chromatin through its N-terminal bromodomains. Following DNA double-strand breaks (DSBs) at the actively transcribed chromatin, the C-terminal extraterminal (ET) domain of BRD3 recruits CHD4 via its KIKL-like motifs to replace HP1 with the TIP60 (Tat-interactive protein, 60 kDa) complex, promoting H4K16 acetylation and MBTD1 recruitment, which creates chromatin barriers to 53BP1. This process recruits BRCA1 and R-loop-processing factors to promote R-loop-mediated homologous recombination (HR) and suppress 53BP1 and mutagenic non-homologous end-joining. Our study elucidates the mechanism by which BRD3 initiates DSB-induced chromatin remodeling by CHD4 and TIP60 to promote R-loop-mediated HR on actively transcribed chromatin to maintain genome stability.

Humans↗