Speeding through the pandemic: Perceptual and psychological factors associated with speeding during the COVID-19 stay-at-home period.

During the COVID-19 stay-at-home period there were observed increases in both the percentage of cars engaged in extreme speeding, and the percentage of cars traveling below the speed limit. These changes have been attributed to unusually low traffic volume during the stay-at-home period. We develop a novel theoretical account, based on existing empirical research, of perceptual and psychological processes that may account for changes in speeding behavior under low traffic volume conditions. These include impaired ability to accurately perceive and control speed due to change in visual information, decreased salience of certain norms about socially appropriate speeds, lower perceived risk of speeding, and increased boredom leading to risk-taking behaviors. Further, we consider that individual attitude functions may account for the observed split in speeding behavior.

Characterization of the nucleolar gene product, treacle, in Treacher Collins syndrome.

Treacher Collins syndrome (TCS) is an autosomal dominant disorder of craniofacial development caused by mutations in the gene TCOF1. Its gene product, treacle, consists mainly of a central repeat domain, which shows it to be structurally related to the nucleolar phosphoprotein Nopp140. Treacle remains mostly uncharacterized to date. Herein we show that it, like Nopp140, is a highly phosphorylated nucleolar protein. However, treacle fails to colocalize with Nopp140 to Cajal (coiled) bodies. As in the case of Nopp140, casein kinase 2 appears to be responsible for the unusually high degree of phosphorylation as evidenced by its coimmunoprecipitation with treacle. Based on these and other observations, treacle and Nopp140 exhibit distinct but overlapping functions. The majority of TCOF1 mutations in TCS lead to premature termination codons that could affect the cellular levels of the full-length treacle. We demonstrate however, that the cellular amount of treacle varies less than twofold among a collection of primary fibroblasts and lymphoblasts and regardless of whether the cells were derived from TCS patients or healthy individuals. Therefore, cells of TCS patients possess a mechanism to maintain wild-type levels of full-length treacle from a single allele.

Analysis of foetal expression sites of human type II DNA topoisomerase alpha and beta mRNAs by in situ hybridisation.

We present the first analysis of the sites of expression of DNA topoisomerase II alpha and II beta mRNAs in human foetal tissues by in situ hybridisation, using 35S-radiolabelled probes. This revealed differential localisation of topoisomerase II alpha and II beta mRNAs in a range of foetal organs, including foetal kidney (developing structures within the neogenic zone), brain (cortical layers), small intestine (crypt epithelium and muscle), liver (hepatocytes), lung (smooth muscle, and epithelium in the lining of primitive lung buds) and placenta (trophoblastic epithelium). The intensity of expression of topoisomerase II alpha mRNA appeared higher than that of topoisomerase II beta, although topoisomerase II beta mRNA was expressed in a broader range of cell types. The distinct patterns of expression of topoisomerase II alpha and beta mRNAs indicate differential regulation of these genes, suggesting that the two isoforms may play important but different roles in foetal development, with topoisomerase II alpha being expressed most strongly in zones of proliferation.

Co-solvent exfoliation and suspension of hexagonal boron nitride.

A simple method is presented for exfoliating and suspending hexagonal boron nitride using a co-solvent approach. A 60 w/w% concentration of tert-butanol in water is very effective at exfoliating boron nitride especially when compared to the individual components alone as indicated by UV-vis and transmission electron microscopy. Molecular weight and surface tension are found to play inverse roles in the exfoliation.

Amsacrine-promoted DNA cleavage site determinants for the two human DNA topoisomerase II isoforms alpha and beta.

Site-specific DNA cleavage by topoisomerase II (EC 5.99.1.3) is induced by many antitumour drugs. Although human cells express two genetically distinct topoisomerase II isoforms, thus far the role and determinants of drug-induced DNA cleavage have been examined only for alpha. Here we report the first high-resolution study of amsacrine (mAMSA) induced DNA breakage by human topoisomerase II beta (overexpressed and purified from yeast) and a direct comparison with the recombinant alpha isoform. DNA cleavage in plasmid pBR322 and SV40 DNA was induced by alpha or beta in the absence or presence of the antitumour agent mAMSA, and sites were mapped using sequencing gel methodology. Low-resolution studies indicated that recombinant human alpha promoted DNA breakage at sites akin to those of beta, although some sites were only cleaved by one enzyme and different intensities were observed at some sites. However, statistical analysis of 70 drug-induced sites for beta and 70 sites for alpha revealed that both isoforms share the same base preferences at 13 positions relative to the enzyme cleavage site, including a very strong preference for A at +1. The result for recombinant alpha isoform is in agreement with previous studies using alpha purified from human cell lines. Thus, alpha and beta proteins apparently form similar ternary complexes with mAMSA and DNA. Previous studies have emphasized the importance of DNA topoisomerase II alpha; the results presented here demonstrate that beta is an in vitro target with similar site determinants, strongly suggesting that beta should also be considered a target of mAMSA in vivo.

Complementation of temperature-sensitive topoisomerase II mutations in Saccharomyces cerevisiae by a human TOP2 beta construct allows the study of topoisomerase II beta inhibitors in yeast.

We show herein that human DNA topoisomerase II beta is functional in yeast. It can complement a yeast temperature-sensitive mutation in topoisomerase II. The effect on human topoisomerase II beta of a number of topoisomerase II inhibitors was analysed in a yeast in vivo system and compared with that of human topoisomerase II alpha and wild-type yeast topoisomerase II. A drug permeable yeast strain (JN394 top2-4) was used to analyse the in vivo effects of known anti-topoisomerase II agents on human topoisomerase II beta transformants. A parallel analysis on human topoisomerase II alpha transformants provides the first in vivo analysis of the responses of yeast bearing the individual isoforms to these drugs. The strain was analysed at 35 degrees C, a non-permissive temperature at which only plasmid-borne topoisomerase II is active. A shuttle vector with either human topoisomerase II beta, human topoisomerase II alpha or yeast topoisomerase II under the control of a GAL1 promoter was used. The key findings were that amsacrine produced comparable levels of cell killing with both alpha and beta, whilst etoposide, doxorubicin and mitoxantrone produced higher degrees of cell killing with alpha than with beta or yeast topoisomerase II. Merbarone had the greatest effect on the yeast strain bearing plasmid-borne yeast topoisomerase II. Suramin, quercetin and genistein showed little cell killing in this system. This yeast in vivo system provides a powerful way to analyse the effects of anti-topoisomerase II agents on transformants bearing the individual human isoforms. This system also provides a means of analysing putative drug-resistance mutations in human topoisomerase II beta or to select for drug-resistance mutations in human topoisomerase II beta.

Conducting meta-analyses of HIV prevention literatures from a theory-testing perspective.

Using illustrations from HIV prevention research, the current article advocates approaching meta-analysis as a theory-testing scientific method rather than as merely a set of rules for quantitative analysis. Like other scientific methods, meta-analysis has central concerns with internal, external, and construct validity. The focus of a meta-analysis should only rarely be merely describing the effects of health promotion, but rather should be on understanding and explaining phenomena and the processes underlying them. The methodological decisions meta-analysts make in conducting reviews should be guided by a consideration of the underlying goals of the review (e.g., simply effect size estimation or, preferably theory testing). From the advocated perspective that a health behavior meta-analyst should test theory, the authors present a number of issues to be considered during the conduct of meta-analyses.

A computer simulation of the electrophoretic separation and detection of the isozymes of creatine kinase.

A program is described, written in BASIC for the Apple II + Computer, which allows for the simulation of a typical experiment in electrophoresis. The subject of the simulation is the separation and detection of the isozymes of creatine kinase, which are important in the diagnosis of several disorders, including myocardial infarction. The program allows the user to investigate the effects of several variables on electrophoretic mobility and includes simulations of isozyme patterns characteristic of specific pathological conditions.

Condoms + pleasure = safer sex? A missing addend in the safer sex message.

Since the emergence of HIV, sexual risk-reduction intervention and prevention programmes have promoted the 'condoms equal safer sex' message with a particular focus on the preventative aspects of condoms (i.e. disease or pregnancy prevention). Yet despite the pervasiveness of this message, research has found that most people fail to use condoms consistently. Using the thought-listing technique, we asked men who have sex with men (MSM) and heterosexuals to list thoughts that immediately came to mind when thinking about condoms. Results show that MSM have more sexual/sensory associations to condoms than heterosexuals, suggesting that interventions highlighting the sexual/sensory aspects of condoms might be an important component to increase condom use among MSM while a combined approach (i.e. messages that integrate preventative, interpersonal, and sexual/sensory components) might be more appealing to heterosexuals.

Sex differences in opioid addiction careers.

Differences between the opioid addiction careers of 84 female and 91 male addicts were examined longitudinally. Data were collected from clients participating in methadone maintenance treatment programs between 1969 and 1972 as part of the Drug Abuse Reporting Program (DARP). Clients were interviewed prior to and during treatment, as well as 6 and 12 years after treatment. No differences between male and female addicts were found for demographic characteristics or treatment histories. Further, differences in behavioral outcomes for criminality and employment found at 12-year follow-up were shown to be a function of pretreatment differences, and were not related to differential treatment effects. Males and females did differ, however, in psychological status at 12-year follow-up, and in their reasons for quitting drug use and entering treatments. These differences, along with significantly greater financial and medical needs for females, indicate systematic long-term differences between female and male addiction careers which should be considered in prevention and treatment of opioid addiction.

Loss of heterozygosity at chromosome 9p in ductal carcinoma in situ and invasive carcinoma of the breast.

Twenty-three cases of ductal carcinoma in situ (DCIS), ten of which had an associated invasive component, were studied for loss of heterozygosity (LOH) of microsatellite markers on chromosome 9p and the results compared with a panel of 20 invasive breast carcinomas. In addition to the gene encoding p16, chromosome 9p is also thought to contain other putative tumour-suppressor genes. If the three panels of breast tumours showed LOH of markers in this region this would suggest that such putative genes were important in breast carcinogenesis. By studying both preinvasive and invasive breast tumours, it should also be possible to gain further information about the relationship between lesions of a different stage and to determine whether DCIS is indeed a precursor of invasive ductal carcinoma. Levels of LOH were low in the invasive-only set of tumours. Surprisingly, considerably higher levels of loss were observed in the tumours with an in situ component. Also, much heterogeneity was observed between different DCIS ducts or invasive tumour and DCIS from the same case.

Frequent alterations of cell cycle regulators in early-stage breast lesions as detected by immunohistochemistry.

Progression through G1 phase of the eukaryotic cell cycle is tightly controlled by cyclin-dependent kinases (CDK). These proteins form part of a regulatory pathway including the cyclin-dependent kinase inhibitor (CKI) p16, D-type cyclins and the product of the retinoblastoma gene pRb. Aberration of any one of these components may lead to uncontrolled proliferation contributing to neoplasia. Three of these proteins, cyclin D1, pRb and p16, were analysed by immunohistochemistry on archival paraffin sections to determine whether expression patterns were different in preinvasive ductal carcinoma in situ (DCIS) and invasive breast tumours relative to normal. Genetic analysis of the gene encoding cyclin D1 (CCND1) was also carried out, using an intragenic restriction fragment-length polymorphism (RFLP) to assess possible allelic imbalance. A majority of the tumours studied (approximately 90%) showed abnormalities in expression of at least one of these proteins. Overexpression of cyclin D1 was found in approximately 49% cases, reduced expression of p16 in approximately 46% and reduced expression of pRb in approximately 37%. Allelic imbalance of cyclin D1 was found in approximately 57% cases.

Eukaryotic DNA topoisomerase II beta.

Type II DNA topoisomerase activity is required to change DNA topology. It is important in the relaxation of DNA supercoils generated by cellular processes, such as transcription and replication, and it is essential for the condensation of chromosomes and their segregation during mitosis. In mammals this activity is derived from at least two isoforms, termed DNA topoisomerase II alpha and beta. The alpha isoform is involved in chromosome condensation and segregation, whereas the role of the beta isoform is not yet clear. DNA topoisomerase II beta was first reported in 1987. Here we review the research on DNA topoisomerase II beta over the last 10 years.

Mutations in the Treacher Collins syndrome gene lead to mislocalization of the nucleolar protein treacle.

Treacher Collins syndrome (TCS) is an autosomal dominant disorder of craniofacial development, the features of which include conductive hearing loss and cleft palate. The TCS gene ( TCOF1 ), which is localized to chromosome 5q32-q33.1, recently has been identified by positional cloning. Analysis of TCOF1 revealed that the majority of TCS mutations result in the creation of a premature termination codon. The function of the predicted protein, treacle, is unknown, although indirect evidence from database analyses suggests that it may function as a shuttling nucleolar phosphoprotein. In the current study, we provide the first direct evidence that treacle is a nucleolar protein. An antibody generated against treacle shows that it localizes to the nucleolus. Fusion proteins tagged to a green fluorescent protein reporter were shown to localize to different compartments of the cell when putative nuclear localization signals were deleted. Parallel experiments using conserved regions of the murine homologue of TCOF1 confirmed these results. Site-directed mutagenesis has been used to recreate mutations observed in individuals with TCS. The resulting truncated proteins are mislocalized within the cell, which further supports the hypothesis that an integral part of treacle's function involves shuttling between the nucleolus and the cytoplasm. TCS is, therefore, the first Mendelian disorder resulting from mutations which lead to aberrant expression of a nucleolar protein.

Heart versus reason in condom use: implicit versus explicit attitudinal predictors of sexual behavior.

We test the hypothesis that explicit and implicit measures of attitudes would differentially predict deliberate versus spontaneous behavior in the domain of condom use. Students completed explicit attitudinal and thought-listing measures about using condoms and implicit measures using attitude priming and Implicit Association Test (IAT) procedures. An attitude IAT measured the association between condom images and affective images; a self-identity IAT measured association of condoms with the self. We predicted and found that condom use with main partners was predicted by explicit measures but not implicit measures; the opposite was true for condom use with casual partners. Although the attitude priming measure was not positively correlated with casual condom use, the IATs were. The patterns of relations, however, were unexpectedly complex, due to a strong decrease in IAT effects over time, and different IATs assessing unique attitudinal dimensions.

Threonine 1342 in human topoisomerase IIalpha is phosphorylated throughout the cell cycle.

To investigate the relationship between the modulation of topoisomerase II activity and its phosphorylation state during the cell cycle, a monoclonal antibody against C-terminal peptide (residues 1335-1350) of topoisomerase IIalpha containing a consensus sequence of casein kinase II, TDDE and its phosphorylated threonine were prepared. In an enzyme-linked immunosorbent assay, the antibody, named PT1342, recognized the immunogenic phosphopeptide but not the non-phosphorylated form of the peptide. The PT1342 antibody reacted only with a 170-kDa protein from HeLa cells and recognized anti-topoisomerase IIalpha immunoprecipitants. Furthermore, the antibody did not react with the human topoisomerase IIalpha mutated at codon 1342 from threonine to alanine, showing that PT1342 was directed against the phosphorylated threonine 1342. To examine the level of phosphorylation of threonine 1342 of topoisomerase IIalpha through the cell cycle, HeLa cells were stained simultaneously for phosphorylated topoisomerase IIalpha and DNA and analyzed by flow cytometry. Cells in the G2-M phase contained about double the PT1341-reacted topoisomerase IIalpha than did cells in G1 or S phases. The antibody stained the nuclei in interphase and mitotic chromosomes and its periphery, as seen with anti-topoisomerase IIalpha antibody. Thus, threonine 1342 in topoisomerase IIalpha is phosphorylated throughout the cell cycle.

Nuclear distribution of human DNA topoisomerase IIbeta: a nuclear targeting signal resides in the 116-residue C-terminal tail.

We have analyzed the subcellular distribution of the beta isoform of human topoisomerase II using both isoform-specific antisera and an epitope-tagging approach. Previous immunocytochemical studies have yielded differing results with one reporting this isoform to be predominantly nucleolar. Later studies seem to refute this finding, as do our results with isoform-specific antisera reported here. Epitope tagging minimizes potential complications arising from the use of anti-topoisomerase II antisera that may recognize epitopes that are modified or masked in vivo and could lead to misleading results in immunocytochemical studies. A second strength of this approach is that it allowed a comparison with similarly tagged control proteins (derived from the nucleolar transcription factor UBF) that were known to localize unambiguously to the cytoplasmic, nucleoplasmic, or nucleolar compartments. We report that the C-terminal domain of topoisomerase IIbeta fused to a beta-galactosidase tag localizes to the nucleus (but not the nucleolar compartment) and that this is indistinguishable from the localization of native topoisomerase IIbeta detected by isoform-specific antisera. Further analysis revealed that the nuclear localization determinant lies within the 116-residue C-terminal tail of human topoisomerase IIbeta.

Expression, domain structure, and enzymatic properties of an active recombinant human DNA topoisomerase II beta.

Human cells express two genetically distinct isoforms of DNA topoisomerase II, alpha and beta, which catalyze ATP-dependent DNA strand passage and are an important antitumor drug target. Here we report for the first time the successful overexpression of human topoisomerase II beta in yeast by cloning a topoisomerase II beta cDNA in a yeast shuttle vector under the control of a galactose-inducible promoter. Recombinant human topoisomerase II beta (residues 46-1621 fused to the first 5 residues of yeast topoisomerase II) was purified to homogeneity, yielding an enzymatically active polypeptide in sufficient quantity to allow analysis of its domain structure and comparison with that of recombinant human topoisomerase II alpha. Partial digestion of beta with either trypsin or protease SV8 generated fragments of approximately 130, 90, 62, and 45-50 kDa, arising from cleavage at three limited and discrete regions of the protein (A, B, and C) indicating the presence of at least four structural domains. Recombinant human topoisomerase II alpha and beta induced DNA breakage which was promoted by a variety of agents. Isoform differences in drug-induced DNA breakage were observed. These studies of human topoisomerase II beta in concert with alpha should aid the determination of their individual roles in cancer chemotherapy and should facilitate the design, targeting, and testing of cytotoxic antitumor agents.