15 research outputs found
Differential actions of glycodelin-A on Th-1 and Th-2 cells: A paracrine mechanism that could produce the Th-2 dominant environment during pregnancy
Background: The maternalfetal interface has a unique immunological response towards the implanting placenta. It is generally accepted that a T-helper type-2 (Th-2) cytokine prevailing environment is important in pregnancy. The proportion of Th-2 cells in the peripheral blood and decidua is significantly higher in pregnant women in the first trimester than in non-pregnant women. Glycodelin-A (GdA) is a major endocrine-regulated decidual glycoprotein thought to be related to fetomaternal defence. Yet the relationship between its immunoregulatory activities and the shift towards Th-2 cytokine profile during pregnancy is unclear. Methods GdA was immunoaffinity purified from human amniotic fluid. T-helper, T-helper type-1 (Th-1) and Th-2 cells were isolated from the peripheral blood. The viability of these cells was studied by XTT assay. Immunophenotyping of CD4/CD294, cell death and GdA-binding were determined by flow cytometry. The mRNA expression, surface expression and secretion of Fas/Fas ligand (FasL) were determined by quantitative polymerase chain reaction, flow cytometry and ELISA, respectively. The activities of caspase-3, -8 and -9 were measured. The phosphorylation of extracellular signal-regulated kinases (ERK), p38 and, c-Jun N-terminal kinase was determined by western blotting. Results Although GdA bound to both Th-1 and Th-2 cells, it had differential actions on the two cell-types. GdA induced cell death of the Th-1 cells but not the Th-2 cells. The cell death was mediated through activation of caspase -3, -8 and -9 activities. GdA up-regulated the expression of Fas and inhibited ERK activation in the Th-1 cells, which might enhance the vulnerability of the cells to cell death caused by a trophoblast-derived FasL. Conclusions The data suggest that GdA could be an endometrial factor that contributes to the Th-2/Th-1 shift during pregnancy. © 2011 The Author.postprin
Artificial neural networks for energy analysis of office buildings with daylighting
An artificial neural network (ANN) model was developed for office buildings with daylighting for subtropical climates. A total of nine variables were used as the input parameters - four variables were related to the external weather conditions (daily average dry-bulb temperature, daily average wet-bulb temperature, daily global solar radiation and daily average clearness index), four for the building envelope designs (solar aperture, daylight aperture, overhang and side-fins projections), and the last variable was day type (i.e. weekdays, Saturdays and Sundays). There were four nodes at the output layer with the estimated daily electricity use for cooling, heating, electric lighting and total building as the output. Building energy simulation using EnergyPlus was conducted to generate daily building energy use database for the training and testing of ANNs. The Nash-Sutcliffe efficiency coefficient for the ANN modelled cooling, heating, electric lighting and total building electricity use was 0.994, 0.940, 0.993, and 0.996, respectively, indicating excellent predictive power. Error analysis showed that lighting electricity use had the smallest errors, from 0.2% under-estimation to 3.6% over-estimation, with the coefficient of variation of the root mean square error ranging from 3% to 5.6%.Energy analysis Artificial neural networks Daylighting Office buildings Optimisation
Impact of climate change on commercial sector air conditioning energy consumption in subtropical Hong Kong
Past and future trend of electricity use for air conditioning in the entire commercial sector in subtropical climates using 1979-2008 measured meteorological data as well as predictions for 2009-2100 from a general circulation model (MIROC3.2-H) was investigated. Air conditioning consumption showed an increasing trend over the past 30Â years from 1979 to 2008. Principal component analysis (PCA) of measured and predicted monthly mean dry-bulb temperature, wet-bulb temperature and global solar radiation was conducted to determine a new climatic index Z for 1979-2008 and future 92Â years (2009-2100) based on two emissions scenarios B1 and A1B (low and medium forcing). Through regression analysis, electricity use in air conditioning for the 92-year period was estimated. For low forcing, average consumption in 2009-2038, 2039-2068 and 2069-2100 would be, respectively, 5.7%, 12.8% and 18.4% more than the 1979-2008 average, with a mean 12.5% increase for the entire 92-year period. Medium forcing showed a similar increasing trend, but 1-4% more. Standard deviations of the monthly air conditioning consumption were found to be smaller suggesting possible reduction in seasonal variations in future years.Commercial sector Electricity use Air conditioning Global warming
Long-term trends of heat stress and energy use implications in subtropical climates
Past and future trends of human comfort in terms of heat and cold stresses under the local subtropical climates using measured meteorological data as well as predictions from general climate models were investigated. Summer discomfort showed an increasing trend (and winter discomfort a decreasing trend) over the past 41Â years from 1968 to 2008. Monthly mean minimum and maximum temperatures and moisture content predictions from a general climate model (MIROC3.2-H) were used to determine summer and winter discomfort for future years (2009-2100) based on two emissions scenarios B1 and A1B (low and medium forcing). The 92-year (2009-2100) mean cold stress would be reduced from the 41-year (1968-2008) mean value of 8.7 to about three for both emissions scenarios. The 92-year mean heat stress would be 115.9 and 120.6 for B1 and A1B, respectively, representing 31.6% and 36.9% increase over the 1968-2008 long-term average of 88.1. These suggest that the already small winter heating requirement in subtropical Hong Kong would become even more insignificant in future years, whereas the increasing trend of summer discomfort would result in more cooling demand in the built environment.Comfort index Climate change Building energy Subtropical Hong Kong
Instagram for student learning and library promotions: a quantitative study using the 5E Instructional Model
Effects of native human zona pellucida glycoproteins 3 and 4 on acrosome reaction and zona pellucida binding of human spermatozoa
Acrosome reaction is crucial to the penetration of spermatozoa through the zona pellucida (ZP). Glycosylation of ZP glycoproteins is important in spermatozoa-ZP interaction. Human ZP glycoprotein-3 (ZP3) is believed to initiate acrosome reaction. Recently, human ZP4 was also implicated in inducing acrosome reaction. These studies were based on recombinant human ZP proteins with glycosylation different from their native counterparts. In the present study, the effects of native human ZP3 and ZP4 on acrosome reaction and spermatozoa-ZP binding were investigated. Native human ZP3 and ZP4 were immunoaffinity-purified. They induced acrosome reaction and inhibited spermatozoa-ZP binding time- and dose-dependently to different extents. These biological activities of human ZP3 and ZP4 depended partly on their glycosylation, with N-linked glycosylation contributing much more significantly than O-linked glycosylation. Studies with inhibitors showed that both human ZP3- and ZP4-induced acrosome reactions were protein kinase-C, protein tyrosine kinase, T-type Ca2+ channels, and extracellular Ca2+ dependent. G-protein also participated in human ZP3- but not in ZP4-induced acrosome reaction. On the other hand, protein kinase-A and L-type Ca 2+ channels took part only in human ZP4-induced acrosome reaction. This manuscript describes for the first time the actions of purified native human ZP3 and ZP4 on acrosome reaction and spermatozoa-ZP binding. © 2008 by the Society for the Study of Reproduction, Inc.link_to_subscribed_fulltex
Hepatitis B Reactivation in Patients With Previous Hepatitis B Virus Exposure Undergoing Rituximab-Containing Chemotherapy for Lymphoma: A Prospective Study
Differential actions of glycodelin-A on Th-1 and Th-2 cells: a paracrine mechanism that could produce the Th-2 dominant environment during pregnancy
Effects of Differential Glycosylation of Glycodelins on Lymphocyte Survival*S⃞
Glycodelin is a human glycoprotein with four reported glycoforms, namely
glycodelin-A (GdA), glycodelin-F (GdF), glycodelin-C (GdC), and glycodelin-S
(GdS). These glycoforms have the same protein core and appear to differ in
their N-glycosylation. The glycosylation of GdA is completely
different from that of GdS. GdA inhibits proliferation and induces cell death
of T cells. However, the glycosylation and immunomodulating activities of GdF
and GdC are not known. This study aimed to use ultra-high sensitivity mass
spectrometry to compare the glycomes of GdA, GdC, and GdF and to study the
relationship between the immunological activity and glycosylation pattern
among glycodelin glycoforms. Using MALDI-TOF strategies, the glycoforms were
shown to contain an enormous diversity of bi-, tri-, and tetra-antennary
complex-type glycans carrying Galβ1–4GlcNAc (lacNAc) and/or
GalNAcβ1–4GlcNAc (lacdiNAc) antennae backbones with varying levels
of fucose and sialic acid substitution. Interestingly, they all carried a
family of Sda (NeuAcα2–3(GalNAcβ1–4)Gal)-containing
glycans, which were not identified in the earlier study because of less
sensitive methodologies used. Among the three glycodelins, GdA is the most
heavily sialylated. Virtually all the sialic acid on GdC is located on the Sda
antennae. With the exception of the Sda epitope, the GdC N-glycome
appears to be the asialylated counterpart of the GdA/GdF glycomes. Sialidase
activity, which may be responsible for transforming GdA/GdF to GdC, was
detected in cumulus cells. Both GdA and GdF inhibited the proliferation,
induced cell death, and suppressed interleukin-2 secretion of Jurkat cells and
peripheral blood mononuclear cells. In contrast, no immunosuppressive effect
was observed for GdS and GdC