Adolescent depression, alcohol and drug abuse

The Diagnostic Interview Schedule was employed to ascertain the prevalence of major depressive disorder (MDD), alcohol and substance abuse in a sample of 424 college students aged 16 to 19 years. Applying DSM III criteria, the prevalence of MDD was 6.8 per cent; of alcohol abuse, 8.2 per cent; and of substance abuse 9.4 per cent. Alcohol abuse was associated with MDD, but not with other psychiatric diagnoses. Substance abuse was associated both with MDD and with other psychiatric diagnoses as well. The onset of MDD almost always preceded alcohol or substance abuse suggesting the possibility of self-medication as a factor in the development of alcohol or substance abuse.

Identification of an autocrine negative growth factor: mouse beta-galactoside-binding protein is a cytostatic factor and cell growth regulator

Murine beta-galactoside-binding protein, a protein classified as a soluble lectin, is shown to be a cell growth-regulatory molecule and a cytostatic factor. The growth-inhibitory effect is not related to lectin properties, and competition assays indicate that the protein binds to specific cell surface receptors with high affinity. It exerts control in G0 and at G2, both as a regulator of cell replication and as a cytostatic factor.

Beta-galactoside-binding protein secreted by activated T cells inhibits antigen-induced proliferation of T cells

We have used mRNA differential display PCR to search for genes induced in activated T cells and have found the LGALS1 (lectin, galactoside-binding, soluble) gene to be strongly up-regulated in effector T cells. The protein coded by the LGALS1 gene is a beta-galactoside-binding protein (betaGBP), which is released by cells as a monomeric negative growth factor but which can also associate into homodimers (galectin-1) with lectin properties. Northern blot analysis revealed that ex vivo isolated CD8+ effector T cells induced by a viral infection expressed high amounts of LGALS1 mRNA, whereas LGALS1 expression was almost absent in resting CD8+ T cells. LGALS1 expression could be induced in CD4+ and CD8+ T cells upon activation with the cognate peptide antigen and high levels of LGALS1 expression were found in concanavalin A-activated T cells but not in lipopolysaccharide-activated B cells. Gel filtration and Western blot analysis revealed that only monomeric betaGBP was released by activated CD8+ T cells and in vitro experiments further showed that recombinant betaGBP was able to inhibit antigen-induced proliferation of naive and antigen-experienced CD8+ T cells. Thus, these data indicate a role of betaGBP as an autocrine negative growth factor for CD8+ T cells.

FimA, a major virulence factor associated with Streptococcus parasanguis endocarditis

Adherence of microorganisms to damaged heart tissue is a crucial event in the pathogenesis of infective endocarditis. In the present study, we investigated the role of the FimA protein as a potential virulence factor associated with Streptococcus parasanguis endocarditis. FimA is a 36-kDa surface protein that is a recognized adhesin in the oral cavity where it mediates adherence to the salivary pellicle. An insertion mutant and a deletion mutant of S. parasanguis were employed in the rat model of endocarditis to determine the relevance of FimA in endocarditis pathogenesis. Catheterized rats were infected with either the fimA deletion mutant VT929, the fimA insertion mutant VT930, or the isogenic, wild-type S. parasanguis FW213. Rats inoculated with FW213 developed endocarditis more frequently (50.9%) than animals inoculated with either the deletion mutant (2.7%) or the insertion mutant (7.6%) (P < 0.001). A series of in vitro assays were performed to explore the mechanism(s) by which FimA enhanced the infectivity of S. parasanguis. FimA did not inhibit the uptake or the subsequent killing of S. parasanguis by phagocytic granulocytes. Similarly, FimA did not play a role in the adherence to or the aggregation of platelets. Significant differences were noted between FW213 and VT929 (P < 0.05) and FW213 and VT930 (P < 0.001) in their abilities to bind to fibrin monolayers. The mean percent adherence of FW213 to fibrin monolayers (2.1%) was greater than those of VT929 (0.5%) and VT930 (0.12%). Taken together, these results indicate that FimA is a major virulence determinant associated with S. parasanguis endocarditis and further suggest that its role is associated with initial colonization of damaged heart tissue.

Expression of the 2-5A system during the cell cycle

To determine whether the 2-5A system has a role in the regulation of cell growth we have examined all constituents of the 2-5A pathway in mouse embryo fibroblasts undergoing one cycle of division at the tertiary stage under conditions where a high degree of uniformity is maintained within each stage of the cycle. Levels of the 2-5A synthetase increased up to tenfold late in S phase and declined as cells moved through G2. A similar but smaller increase in the 2-5A-dependent ribonuclease was observed, whereas activity of the 2'5' phosphodiesterase was highest in quiescent cells. At the time of maximum synthetase levels no phosphorylated 2-5A could be detected in the intact cell. Endogenous interferon (IFN) was found in the culture supernatants in increasing concentration with cell cycle progression and addition of antibodies to IFN reduced the increase in synthetase seen in late S. Treatment of cells with a growth inhibitor that cells produce also affected synthetase activity.

Properties of a cell growth inhibitor produced by mouse embryo fibroblasts

Secondary mouse embryo fibroblasts produce a growth inhibitor with the character of a thermolabile, nondialysable protein. The inhibitor was harvested from conditioned medium, and following G-75 Sephadex fractionation it was isolated in one peak which consisted of two fractions eluting at approximately two thirds of the bed volume of the column where approximately 80 percent of the original activity was recovered with an increase in specific activity of about tenfold. Polyacrylamide gradient gel electrophoresis of fractions from L-[35S] methionine-labelled conditioned medium showed that the two fractions with growth inhibitory activity contained some 4-5 bands and shared the two major components. Cell cycle studies showed that the growth inhibitory effect was exerted after addition during early and late G1 and during S phase, and morphological studies showed that where growth was inhibited the morphological expression of the cells was altered.

Cell cycle arrest and induction of apoptosis by beta galactoside binding protein (beta GBP) in human mammary cancer cells. A potential new approach to cancer control

Conflict between mitogenic pressure, as is the case in tumour cells and an imposed inability to proceed through the cell cycle may result in cell death. In the present study we examined the effect of beta galactoside binding protein (beta GBP), a negative growth factor which controls cell cycle transition from S phase into G2, on three human mammary cell lines which differ for oncogenic potential, oestrogen receptor expression and expression of the EGF receptor family. We found that in all cases beta GBP induced a cell cycle block prior to the cells' entry into G2 and that this was followed by progressive apoptotic death. This evidence on epithelial cancer cells parallels previous data on tumour cells of mesenchymal origin and suggests that beta GBP has potential therapeutic implications in the treatment of cancers.

Cohort and case-control analyses of workers exposed to vinyl chloride: an update

The mortality in a cohort of workers at a vinyl chloride polymerization plant has been updated, extending the period of observation in the original study from 1974 to 1986. Workers at this plant may have been exposed to vinyl chloride monomer and/or polyvinyl chloride dust, or may have had no exposure to either substance. Seventy-six percent of the work force worked in jobs with potential exposure to vinyl chloride monomer. Among the total cohort, statistically significant excess risks were observed for liver, lung, and brain cancer. For the subcohort of workers exposed to vinyl chloride monomer, the standardized mortality ratio (SMR) for liver cancer was 333 (90% confidence interval (CI) 202 to 521). However, there were no significant excesses of either brain (SMR = 145, 90% CI 78 to 249) or lung cancer (SMR = 115, 90% CI 96 to 141). To investigate dose response, nested case-control studies for liver, brain, and lung cancer were conducted among the total cohort (including the nonexposed). For these studies there were two exposure variables, cumulative dose of vinyl chloride monomer and cumulative dose of polyvinyl chloride dust. Cumulative dose was defined as the product of level and duration of exposure. The only significant association between disease risk and cumulative dose was for liver cancer and cumulative dose of vinyl chloride monomer. Further division of the liver cancers into angiosarcoma (n = 12) and other liver cancers (n = 7), based on review of death certificates and medical records, showed that the dose response existed only for angiosarcomas.

Negative cell cycle control of human T cells by beta-galactoside binding protein (beta GBP): induction of programmed cell death in leukaemic cells

The cell cycle is negatively regulated by diverse molecular events which originate in part from the interaction of secreted proteins with specific cell surface receptors. By exerting negative control on cell proliferation, these factors can help maintain cell number balance both through growth restraints and the induction of apoptosis and may thus contribute to prevent or control tumourigenesis. Here we report that betaGBP, a negative growth factor which controls transition from S phase into G2, causes an S/G2 growth arrest in both normal and leukaemic T cells. However, in leukaemic T cells but not in normal T lymphocytes, growth arrest is followed by apoptosis. Analysis of possible mechanisms of induction of apoptosis does not support Fas and Fas L as having a main role but points instead to Bcl-2 and Bax. The induction of apoptosis in leukaemic T cells is characterised by the decrease of Bcl-2 and consequent predominance of Bax. By contrast, in the normal T cells, which do not enter apoptosis, the quantitative relationship of Bcl-2 to Bax remains unchanged. The ability of betaGBP to selectively induce apoptosis in leukaemic cells suggests that betaGBP may play a role in cancer surveillance and that its use has potential therapeutic implications.

Structure and expression of the negative growth factor mouse beta-galactoside binding protein gene

Following the identification of murine beta-galactoside binding protein (mGBP) as an autocrine negative growth factor we have now isolated and characterized the genomic region spanning the mGBP gene and have determined the 5' end of the transcript by primer extension, S1 mapping and mRNA sequence. The gene is found to be contained within 4 kilobases and composed of four exons of 79, 80, 171 and 197 nucleotides separated by three introns of 1200, 1600 and 193 nucleotides. The DNA region upstream of the 5' end of the transcript contains canonical sequences for eukaryotic promoter elements including CAT and TATA boxes and several DNA motifs for potential transcription regulation. The gene is differentially expressed in a variety of normal tissues.

Functional inhibition of PI3K by the betaGBP molecule suppresses Ras-MAPK signalling to block cell proliferation

The mechanisms of signal transduction from cell surface receptors to the interior of the cell are fundamental to the understanding of the role that positive and negative growth factors play in cell physiology and in human diseases. Here, we show that a functional link between phosphatidylinositol-3-OH kinase (PI3K) and Ras is suppressed by the beta-galactoside binding protein (betaGBP) molecule, a cytokine and a negative cell-cycle regulator. Ras-mitogen-activated protein kinase (MAPK) signalling is blocked by betaGBP owing to its ability to inhibit the p110 catalytic subunit of PI3K, whose basal activity is required for Ras activation. Functional inhibition of p110 by betaGBP results in downregulation of PI3K activity, suppression of Ras-GTP loading, consequent loss of MAPK activation and block of cell proliferation. This study sheds light on the molecular mechanisms whereby betaGBP can control cell proliferation and, by extension, may potentially control tumorigenesis by controlling PI3K.

Molecular expression of the negative growth factor murine beta-galactoside binding protein (mGBP)

Characterisation of the negative growth factor mGBP at molecular and biological levels indicates that the protein has no lectin nature and suggests instead a participation in the cytokine network. The protein is shown to be expressed as a monomer in two forms, one of which is non-covalently linked to a glycan complex. This confers greater efficiency to the inhibitor and may favour a paracrine role. The two monomeric forms may oxidise into tetramers which retain biological activity, but lack ability to link to specific saccharide residues.

Management of arterial lines and blood sampling in intensive care: a threat to patient safety

In 2008, the UK National Patient Safety Agency (NPSA) made recommendations for safe arterial line management. Following a patient safety incident in our intensive care unit (ICU), we surveyed current practice in arterial line management and determined whether these recommendations had been adopted. We contacted all 241 adult ICUs in the UK; 228 (94.6%) completed the survey. Some NPSA recommendations have been widely implemented - use of sodium chloride 0.9% as flush fluid, two-person checking of fluids before use - and their practice was consistent. Others have been incompletely implemented and many areas of practice (prescription of fluids, two-person checking at shift changes, use of opaque pressure bags, arterial sampling technique) were highly variable. More importantly, the use of the wrong fluid as an arterial flush was reported by 30% of respondents for ICU practice, and a further 30% for practice elsewhere in the hospital. Our survey provides evidence of continuing risk to patients.

Cell cycle regulation (G1) by autocrine interferon and dissociation between autocrine interferon and 2',5'-oligoadenylate synthetase expression

In tertiary MEF undergoing cell cycle progression, autocrine interferon (IFN) is released and constitutive levels of 2',5'-oligoadenylate (2-5A) synthetase activity, low through the cell cycle, surge into a peak within S phase. Treatment of MEF with the autocrine IFN they produce elicits a 2-5A synthetase response from cells positioned in G0 but not from cells in G1 and from cells in S phase. Neutralization of the autocrine IFN by antibody shortens the length of G1 leaving unaltered the kinetics of progression through S and G2 and has no effect on the S phase-linked expression of 2-5A synthetase activity. The growth controlling effect of the autocrine IFN has been mapped to the second part of G1.

Mapping on human and mouse chromosomes of the gene for the beta-galactoside-binding protein, an autocrine-negative growth factor

The structural gene for beta-galactoside-binding protein (Lgals-1), a cell growth regulatory molecule and cystostatic factor, is assigned to the E-region of mouse chromosome 15 and to the region q12-q13.1 of human chromosome 22. The evolutionary conservation of these two regions has been previously suggested from comparative mapping of several loci. These include the murine SIS oncogene (Pdgfb) and its human homolog, the platelet-derived growth factor-beta polypeptide, PDGFB. The findings presented here extend the genetic homology of the two regions.

Nature-Based Early Childhood Education and Children's Physical Activity, Sedentary Behavior, Motor Competence, and Other Physical Health Outcomes: A Mixed-Methods Systematic Review

BACKGROUND

The purpose was to synthesize evidence on the association between nature-based Early Childhood Education (ECE) and children's physical activity (PA) and motor competence (MC).

METHODS

A literature search of 9 databases was concluded in August 2020. Studies were eligible if (1) children were aged 2-7 years old and attending ECE, (2) ECE settings integrated nature, and (3) assessed physical outcomes. Two reviewers independently screened full-text articles and assessed study quality. Synthesis was conducted using effect direction (quantitative), thematic analysis (qualitative), and combined using a results-based convergent synthesis.

RESULTS

1370 full-text articles were screened and 39 (31 quantitative and 8 qualitative) studies were eligible; 20 quantitative studies assessed PA and 6 assessed MC. Findings indicated inconsistent associations between nature-based ECE and increased moderate to vigorous PA, and improved speed/agility and object control skills. There were positive associations between nature-based ECE and reduced sedentary time and improved balance. From the qualitative analysis, nature-based ECE affords higher intensity PA and risky play, which could improve some MC domains. The quality of 28/31 studies was weak.

CONCLUSIONS

More controlled experimental designs that describe the dose and quality of nature are needed to better inform the effectiveness of nature-based ECE on PA and MC.

A cell cycle study of the effects of Con A on synchronized mouse embryo fibroblasts: arrest at two specific stages of the cycle and dissociation between uptake of thymidine and DNA synthesis

We have examined the effects of 50 microgram ml-1 of Con A added to synchronized mouse embryo fibroblasts at different times during the cell cycle. We found that Con A caused arrest of growth not solely by preventing G1-G0 cells from entering the S-phase but also by exerting a G2 block. We also found that Con A, which prevented commencement of S-phase, did not arrest cells already in S from reaching the G2 stage but inhibited the S-phase associated process of thymidine uptake. The inhibition was greater when the Con A receptors were extensively clustered.

Cell cycle study on the effect of interferon on synchronized mouse embryo fibroblasts

Mouse embryo fibroblasts synchronized by controlling cultural conditions were used to examine the effects of interferon (IFN) while undergoing a single synchronous cycle of division at the tertiary stage. IFN was added early in G1 and at the G1-S boundary and the duration of specific phases of the cycle were investigated together with biochemical events related to cell cycle progression. Assessment of population distribution by fluorimetric quantitation of DNA content showed that IFN extended G1 and G2 but had no effect on the duration of S phase. Assessment of transport and uptake of exogenous TdR and measurements of specific kinase activity under conditions where DNA synthesis and S phase were not altered showed that IFN had no effect on TdR transport but could markedly reduce TdR uptake, and delay the S phase associated increase of TdR-kinase activity.

Patient selection criteria for blastocyst culture in IVF/ICSI treatment

BACKGROUND

The development and refinement of blastocyst media in recent years has allowed embryos to be cultured in-vitro for 5 or 6 days post oocyte retrieval and has been established as an effective selection tool to aid embryo selection for IVF treatment. It is generally accepted that blastocyst culture is not an appropriate option for all patients but the criteria for patient selection varies between clinics. Our blastocyst culture programme started in February 2005; the patient criteria was set at a minimum of 4 oocytes retrieved, a minimum of 4 2PN pronuclear embryos and at least 4 8-cell embryos of any quality on Day 3 where the female patient was 34 years and under. In the female age group of 35 years and over the criteria was at least 6 oocytes retrieved, a minimum of 6 2PN pronuclear embryos and at least 6 8-cell embryos of any quality on day 3. Improvements in pregnancy rates demonstrated the effectiveness of blastocyst transfer and clinical opinion was that the criteria should be adjusted to allow this option to be available to an increased patient population. From February 2007 the blastocyst patient selection criteria was changed to at least 4 oocytes retrieved, at least 4 2PN pronuclear embryos and at least 2 8-cell and 2 6-cell or 7-cell embryos of top quality on Day 3 in women 38 years and under. For women 39 years and over the criteria was lowered to at least 5 eggs retrieved, at least 5 2PN and at least 3 8-cell embryos and 2 6-cell embryos of top quality on Day 3.

METHODS

Retrospective statistical analysis was carried out to determine the pregnancy rates, live birth rates and twin rate for the period under the initial criteria and to examine the impact that lowering the criteria for patient selection for blastocyst culture had on these parameters.

RESULTS

There was an overall fall in the ongoing pregnancy/live birth rate from 50.9% under the old criteria to 45.0% under the new criteria. However, the patients who had blastocyst culture under the new criteria but would have had day-3 embryo transfer under the initial criteria had a significantly increased live birth/ongoing pregnancy rate from 22.7% to 40.7%. There is an increase in the number of blastocyst culture cycles from 26.4% under the old criteria to 39.1% with the refined criteria. The twin pregnancy rate was reduced from 25.2% to 17.5%.

CONCLUSION

The result of this cohort study revealed that lowering the blastocyst selection criteria may lead to a lower overall clinical live birth rate from blastocyst culture; however, it will benefit a specific group of patients to achieve a better pregnancy and live birth rate. Furthermore, it increases the number of patients who will benefit from the blastocyst culture programme and also reduces multiple pregnancy rate.

Cell cycle position and expression of encephalomyocarditis virus in mouse embryo fibroblasts

Infection of mouse embryo fibroblasts in G1 or S phase with encephalomyocarditis virus gave different kinetics of viral RNA synthesis. In S phase cells, RNA synthesis was faster and reached higher levels than in G1 cells. Virus-specified proteins were fewer in G1 cells than in S cells during the early stage of the infection and c.p.e. in G1 cells appeared about 4 h later than in S cells. Addition of a cellular factor with ability to affect cell conformation had an inhibitory effect on viral RNA synthesis.