Porcine dentin sialoprotein glycosylation and glycosaminoglycan attachments

<p>Abstract</p> <p>Background</p> <p>Dentin sialophosphoprotein (Dspp) is a multidomain, secreted protein that is critical for the formation of tooth dentin. Mutations in <it>DSPP </it>cause inherited dentin defects categorized as dentin dysplasia type II and dentinogenesis imperfecta type II and type III. Dentin sialoprotein (Dsp), the N-terminal domain of dentin sialophosphoprotein (Dspp), is a highly glycosylated proteoglycan, but little is known about the number, character, and attachment sites of its carbohydrate moieties.</p> <p>Results</p> <p>To identify its carbohydrate attachment sites we isolated Dsp from developing porcine molars and digested it with endoproteinase Glu-C or pronase, fractionated the digestion products, identified fractions containing glycosylated peptides using a phenol sulfuric acid assay, and characterized the glycopeptides by N-terminal sequencing, amino acid analyses, or LC/MSMS. To determine the average number of sialic acid attachments per N-glycosylation, we digested Dsp with glycopeptidase A, labeled the released N-glycosylations with 2-aminobenzoic acid, and quantified the moles of released glycosylations by comparison to labeled standards of known concentration. Sialic acid was released by sialidase digestion and quantified by measuring β-NADH reduction of pyruvic acid, which was generated stoichiometrically from sialic acid by aldolase. To determine its forms, sialic acid released by sialidase digestion was labeled with 1,2-diamino-4,5-methyleneoxybenzene (DMB) and compared to a DMB-labeled sialic acid reference panel by RP-HPLC. To determine the composition of Dsp glycosaminoglycan (GAG) attachments, we digested Dsp with chondroitinase ABC and compared the chromotagraphic profiles of the released disaccharides to commercial standards. N-glycosylations were identified at Asn³⁷, Asn⁷⁷, Asn¹³⁶, Asn¹⁵⁵, Asn¹⁶¹, and Asn¹⁷⁶. Dsp averages one sialic acid per N-glycosylation, which is always in the form of N-acetylneuraminic acid. O-glycosylations were tentatively assigned at Thr²⁰⁰, Thr²¹⁶and Thr³¹⁶. Porcine Dsp GAG attachments were found at Ser²³⁸and Ser²⁵⁰and were comprised of chondroitin 6-sulfate and chondroitin 4-sulfate in a ratio of 7 to 3, respectively.</p> <p>Conclusions</p> <p>The distribution of porcine Dsp posttranslational modifications indicate that porcine Dsp has an N-terminal domain with at least six N-glycosylations and a C-terminal domain with two GAG attachments and at least two O-glycosylations.</p

Prevention and treatment of cardiovascular instability during spinal anaesthesia for caesarean section

Spinal anaesthesia is the method of choice for caesarean section. There is however a significant associated morbidity and mortality in South Africa, particularly in inexperienced hands. This review provides recommendations for safe practice for anaesthetists at all levels of expertise, with particular reference to the management of haemodynamic instability. S Afr Med J 2004; 94: 367-372

Optimization viewpoint on Kalman smoothing, with applications to robust and sparse estimation

In this paper, we present the optimization formulation of the Kalman filtering and smoothing problems, and use this perspective to develop a variety of extensions and applications. We first formulate classic Kalman smoothing as a least squares problem, highlight special structure, and show that the classic filtering and smoothing algorithms are equivalent to a particular algorithm for solving this problem. Once this equivalence is established, we present extensions of Kalman smoothing to systems with nonlinear process and measurement models, systems with linear and nonlinear inequality constraints, systems with outliers in the measurements or sudden changes in the state, and systems where the sparsity of the state sequence must be accounted for. All extensions preserve the computational efficiency of the classic algorithms, and most of the extensions are illustrated with numerical examples, which are part of an open source Kalman smoothing Matlab/Octave package.Comment: 46 pages, 11 figure

Type IIn supernovae at z ~ 2 from archival data

Supernovae have been confirmed to redshift z ~ 1.7 for type Ia (thermonuclear detonation of a white dwarf) and to z ~ 0.7 for type II (collapse of the core of the star). The subclass type IIn supernovae are luminous core-collapse explosions of massive stars and, unlike other types, are very bright in the ultraviolet, which should enable them to be found optically at redshifts z ~ 2 and higher. In addition, the interaction of the ejecta with circumstellar material creates strong, long-lived emission lines that allow spectroscopic confirmation of many events of this type at z ~ 2 for 3 - 5 years after explosion. Here we report three spectroscopically confirmed type IIn supernovae, at redshifts z = 0.808, 2.013 and 2.357, detected in archival data using a method designed to exploit these properties at z ~ 2. Type IIn supernovae directly probe the formation of massive stars at high redshift. The number found to date is consistent with the expectations of a locally measured stellar initial mass function, but not with an evolving initial mass function proposed to explain independent observations at low and high redshift.Comment: 8 pages, 2 figures, includes supplementary informatio

LGBT+ Youth Perspectives on Sexual Orientation and Gender Identity Questions in the Growing Up in Ireland Survey: A Qualitative Study

The increasing importance of identifying lesbian, gay, bisexual and transgender (LGBT+) populations is a key driver in changes to demographic data collection in representative surveys of youth. While such population-based data are rare, Growing Up in Ireland (GUI), an Irish, government-funded, longitudinal survey, includes sexual orientation and gender identity (SOGI) measurements. This qualitative study responds to a query from the GUI study team and aims to identify how best to collect SOGI data in future waves of GUI. A university Human Research Ethics Committee granted approval for online consultations with LGBT+ youth (n = 6) with experiential expertise in policy making. The research is underpinned by rights-based public patient involvement (PPI) with recorded discussions, which were transcribed and imported into NVivo 12, generating the theme “recognition in research, policy and society”. This co-created article, with the LGBT+ young PPI Panel members, commends the inclusion of SOGI data in GUI and recommends changes in question placement and phrasing. Aligning with best practice, the PPI members provide a template for wording on consecutive sex and gender questions, expanded sexual orientation identity categories and maintaining the existing well-phrased transgender question from GUI. This offers potential to improve the quality of the SOGI data collected and the experience of those completing the questionnaire. These findings extend beyond GUI, with relevance for surveys with youth populations. This paper underscores the potential and benefits of participatory approaches to research with youth and views their role beyond simply as sources of data

Determinants and consequences of short birth interval in rural Bangladesh: a cross-sectional study.

BACKGROUND: Short birth intervals are known to have negative effects on pregnancy outcomes. We analysed data from a large population surveillance system in rural Bangladesh to identify predictors of short birth interval and determine consequences of short intervals on pregnancy outcomes. METHODS: The study was conducted in three districts of Bangladesh - Bogra, Moulavibazar and Faridpur (population 282,643, 54,668 women of reproductive age). We used data between January 2010 and June 2011 from a key informant surveillance system that recorded all births, deaths and stillbirths. Short birth interval was defined as an interval between consecutive births of less than 33 months. Initially, risk factors of a short birth interval were determined using a multivariate mixed effects logistic regression model. Independent risk factors were selected using a priori knowledge from literature review. An adjusted mixed effects logistic regression model was then used to determine the effect of up to 21-, 21-32-, 33-44- and 45-month and higher birth-to-birth intervals on pregnancy outcomes controlling for confounders selected through a directed acyclic graph. RESULTS: We analysed 5,571 second or higher order deliveries. Average birth interval was 55 months and 1368/5571 women (24.6%) had a short birth interval (<33 months). Younger women (AOR 1.11 95% CI 1.08-1.15 per year increase in age), women who started their reproductive life later (AOR 0.95, 0.92-0.98 per year) and those who achieve higher order parities were less likely to experience short birth intervals (AOR 0.28, 0.19-0.41 parity 4 compared to 1). Women who were socioeconomically disadvantaged were more likely to experience a short birth interval (AOR 1.42, 1.22-1.65) and a previous adverse outcome was an important determinant of interval (AOR 2.10, 1.83-2.40). Very short birth intervals of less than 21 months were associated with increased stillbirth rate (AOR 2.13, 95% CI 1.28-3.53) and neonatal mortality (AOR 2.28 95% CI 1.28-4.05). CONCLUSIONS: Birth spacing remains a reproductive health problem in Bangladesh. Disadvantaged women are more likely to experience short birth intervals and to have increased perinatal deaths. Research into causal pathways and strategies to improve spacing between pregnancies should be intensified

Bioactivity-guided identification and cell signaling technology to delineate the immunomodulatory effects of Panax ginseng on human promonocytic U937 cells

<p>Abstract</p> <p>Background</p> <p>Ginseng is believed to have beneficial effects against human diseases, and its active components, ginsenosides, may play critical roles in its diverse physiological actions. However, the mechanisms underlying ginseng's effects remain to be investigated. We hypothesize some biological effects of ginseng are due to its anti-inflammatory effects.</p> <p>Methods</p> <p>Human promonocytic U937 cells were used to investigate the immunomodulatory effects of ginseng following TNF-α treatment. A global gene expression profile was obtained by using genechip analysis, and specific cytokine expression was measured by quantitative RT-PCR and ELISA. HPLC was used to define the composition of ginsenosides in 70% ethanol-water extracts of ginseng. Activation of signalling kinases was examined by Western blot analysis.</p> <p>Results</p> <p>Seventy percent ethanol-water extracts of ginseng significantly inhibited the transcription and secretion of CXCL-10 following TNF-α stimulation. Nine ginsenosides including Rb₁, Rb₂, Rc, Rd, Re, Rf, Rg₁, Rg₃and Rh₁were identified in our extract by HPLC. Seven out of nine ginsenosides could significantly inhibit TNF-α-induced CXCL-10 expression in U937 cells and give comparable inhibition of CXCL-10 transcription to those with the extract. However, the CXCL-10 suppressive effect of individual ginsenosides was less than that of the crude extract or the mixture of ginsenosides. The CXCL-10 suppression can be correlated with the inactivation of ERK1/2 pathways by ginseng.</p> <p>Conclusion</p> <p>We showed ginseng suppressed part of the TNF-α-inducible cytokines and signalling proteins in promonocytic cells, suggesting that it exerts its anti-inflammatory property targeting at different levels of TNF-α activity. The anti-inflammatory role of ginseng may be due to the combined effects of ginsenosides, contributing in part to the diverse actions of ginseng in humans.</p

The Complete Star Formation History of the Universe

The determination of the star-formation history of the Universe is a key goal of modern cosmology, as it is crucial to our understanding of how structure in the Universe forms and evolves. A picture has built up over recent years, piece-by-piece, by observing young stars in distant galaxies at different times in the past. These studies indicated that the stellar birthrate peaked some 8 billion years ago, and then declined by a factor of around ten to its present value. Here we report on a new study which obtains the complete star formation history by analysing the fossil record of the stellar populations of 96545 nearby galaxies. Broadly, our results support those derived from high-redshift galaxies elsewhere in the Universe. We find, however, that the peak of star formation was more recent - around 5 billion years ago. Our study also shows that the bigger the stellar mass of the galaxy, the earlier the stars were formed. This striking result indicates a very different formation history for high- and low-mass formation.Comment: Accepted by Nature. Press embargo until publishe

Solar UV Doses of Young Americans and Vitamin D3 Production

Background: Sunlight contains ultraviolet B (UVB) radiation (290–315 nm) that affects human health in both detrimental (skin cancers) and beneficial (vitamin D3) ways. Serum 25-hydroxyvitamin D concentrations from young Americans (≤ 19 years) show that many have deficient (< 50 nmol/L, 20 ng/mL) or insufficient (< 75 nmol/L, 30 ng/mL) vitamin D levels, indicating that they are not getting enough sun exposure. Those findings are in conflict with some calculated, published values that suggest people make “ample” vitamin D3 (~ 1,000 IU/day) from their “casual,” or everyday, outdoor exposures even if they diligently use sunscreens with sun protection factor (SPF) 15