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Objectives: This study aimed to evaluate associations between mental distress and COVID-19-related changes in behavioral outcomes and potential modifiers (age, gender, educational attainment) of such associations., Study Design: This was a cross-sectional study., Methods: An online survey using anonymous network sampling was conducted in China from April to May 2020 using a 74-item questionnaire. A national sample of 10,545 adults in 31 provinces provided data on sociodemographic characteristics, COVID-19-related mental distress, and changes in behavioral outcomes. Structural equation models were used for data analyses., Results: After adjusting for covariates, greater mental distress was associated with increased smoking (odds ratio [OR] = 1.42, 95% confidence interval [CI]: 1.20-1.68 and OR = 1.54, 95% CI: 1.31-1.82 per one standard deviation [SD] increase in mental distress) and alcohol consumption (OR = 1.67, 95% CI: 1.45-1.92 and OR = 1.47, 95% CI: 1.24-1.75 per one SD increase in mental distress) among current smokers and drinkers and with both increased and decreased physical activity (ORs ranged from 1.32 to 1.56). Underweight adults were more likely to lose body weight (≥1 kg; OR = 1.63, 95% CI: 1.30-2.04), whereas overweight adults were more likely to gain weight (OR = 1.61, 95% CI: 1.46-1.78) by the same amount. Association between mental distress and change in physical activity was stronger in adults aged ≥40 years (ORs ranged from 1.43 to 2.05) and those with high education (ORs ranged from 1.43 to 1.77). Mental distress was associated with increased smoking in males (OR = 1.60, 95% CI: 1.37-1.87) but not females (OR = 1.11, 95% CI: 0.82-1.51)., Conclusions: Greater mental distress was associated with some positive and negative changes in behavioral outcomes during the pandemic. These findings inform the design of tailored public health interventions aimed to mitigate long-term negative consequences of mental distress on outcomes., (Copyright © 2021 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.)

Essentials The role of von Willebrand factor (VWF) domains in regulating platelet adhesion was studied in vivo. Multimeric VWF with spacers at the N- and C-terminus of VWF-A1 were systematically tested. N-terminal modified VWF avidly bound platelet GpIbα, causing VWD Type2B like phenotype in mice. Novel anti-D'D3 mAbs suggest that changes at the D'D3-A1 interface may be biologically relevant., Summary: Background Previous ex vivo studies using truncated VWF (von Willebrand factor) suggest that domain-level molecular architecture may control platelet-GpIbα binding function. Objective We determined if this is the case with multimeric VWF in vivo. Methods Full-length human VWF ('hV') was modified with a 22-amino acid mucinous stretch at either the N-terminus of VWF-A1 to create 'hNV' or C-terminus to yield 'hCV'. This extends the physical distance between VWF-A1 and the adjacent domains by ~6 nm. Similar mucin inserts were also introduced into a human-murine chimera ('h[mA1]V') where murine-A1 replaced human-A1 in hV. This yielded 'h[mA1]NV' and 'h[mA1]CV', with N- and C-terminal inserts. The constructs were tested ex vivo and in vivo. Results Mucin insertion at the N-terminus, but not C-terminus, in both types of constructs resulted in >50-fold increase in binding to immobilized GpIbα. N-terminal insertion also resulted in greater shear-induced platelet activation, more thrombus formation on collagen, enhanced platelet accumulation and slower platelet translocation on immobilized VWF in microfluidics assays. Hydrodynamic injection-based expression of h[mA1]NV, but not h[mA1]V or h[mA1]CV, in VWF -/- mice caused profound thrombocytopenia, reduced plasma VWF concentrations, lower multimer distribution, and incessant tail bleeding that is reminiscent of von Willebrand disease type 2B. Platelet plugs were noted in the portal veins and hepatic arteries. An anti-D'D3 mAb DD3.3 that displays enhanced binding to VWF containing the N-terminal mucin insert also exhibited increased binding to wild-type VWF under shear and upon ristocetin addition. Conclusion Conformation changes at the VWF D'D3-A1 interface may be a key regulator of thrombosis in vivo. Structural features at the A1-A2 interface are likely of less significance., (© 2017 International Society on Thrombosis and Haemostasis.)

A large-scale national survey was conducted in 2008 across 61 cities throughout China, covering over 18,000 men who have sex with men (MSM). The prevalence of human immunodeficiency virus (HIV) was 4.9% and incidence ranged from 2.6 to 5.4 per 100 person-years. The prevalence of sexually transmitted diseases ranged from 2.0% to 29.9% among MSM in different parts of China. Syphilis status, recruitment of sexual partners mainly from gay saunas, duration of MSM experience, and unprotected sex with regular male sex partners and multiple male sex partners predicted HIV seroconversion. The prevalence of consistent condom use was low during anal sex, ranging from 29.4% to 37.3%. Within this context, this paper considers the factors surrounding HIV prevention activity, and identifies a number of public health challenges which need to be considered if optimum outcomes are to be achieved. HIV prevention targeting MSM is a delayed response. The high risk associated with gay saunas and the need for steady condom supply at these venues needs urgent consideration. In addition, approximately one-third of MSM in China reported bisexual behavior, which may be attributed to sociocultural reasons and stigma against MSM. Female sex partners of MSM are seldom aware of their exposure to high risk of HIV transmission. Finally, the primitive nature of non-government organizations for HIV prevention and issues around their sustainability pose another serious challenge for the future of HIV prevention campaigns targeting MSM in China., (Copyright © 2011 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.)

Objectives: To investigate the prevalence and factors associated with uptake of voluntary counselling and testing (VCT) for human immunodeficiency virus (HIV) among men who have sex with men (MSM) in Hong Kong., Study Design: Cross-sectional study., Methods: A total of 389 MSM were recruited from gay venues. An additional 188 MSM were recruited through the Internet. Data were collected via face-to-face interviews using a self-administered anonymous questionnaire or via an electronic questionnaire accessible via local gay-friendly websites. The associations between independent and dependent variables (VCT uptake in lifetime and in last 12 months) were examined by logistic regression models., Results: The prevalence rates for lifetime and 12-month uptake of VCT were 56.5% and 39.4%, respectively. Adjusting for significant background variables, all cognitive variables (attitudes, subjective norms, perceived control and behavioural intention) that were derived from the Theory of Planned Behaviours (TPB) were significantly associated with both lifetime and 12-month uptake of VCT [adjusted odds ratio (AOR) 0.56-4.71, P < 0.05]. Perceived fear of contracting HIV and perceived discrimination towards local MSM were associated with a lower likelihood of 12-month uptake of VCT (AOR 0.63, P < 0.05) and lifetime uptake (AOR 0.65, P < 0.05). In the summary models, variables derived from the TPB (subjective norms, perceived control and behavioural intention) were independently associated with lifetime and 12-month uptake of VCT (OR 0.64-2.78, P < 0.05; OR 2.39-3.21, P < 0.05, respectively). Fear of contracting HIV was associated with VCT uptake in the last 12 months (OR 0.55, P < 0.05)., Conclusions: Psychological factors are associated with VCT uptake. The TPB and other health behavioural theories should be taken into account when designing VCT promotion campaigns., (Copyright © 2011 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.)

Objectives: University students, both travelling abroad on holiday or exchange students entering a country, can serve as mobile carriers of infectious diseases during a pandemic, and thus require special attention when considering preventive measures. The objectives of this study were to evaluate student compliance and opinions on preventive measures of a university before and during an H1N1 influenza pandemic, and to explore environmental and behavioural factors that might contribute towards compliance., Study Design: Cross-sectional, self-administered questionnaire., Methods: Local and foreign students attending an international summer school programme were invited to participate in a self-administered survey., Results: Respondents complied with most of the preventive measures, excluding website viewing and mask wearing. Significant differences in compliance and perceived necessity were found amongst students from Singapore, Hong Kong and the USA. Singaporean students were significantly more likely to comply with all measures and consume antiviral medication in response to the pandemic than students studying in the US., Conclusions: Students' responses towards university pandemic measures were largely positive, but sensitivity towards these measures varied between groups by country of study. This should be considered in further comparative studies., (Copyright 2010 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.)

Purpose: To estimate the prevalences of common illnesses in Hong Kong adolescents, the sociodemographic and selected risk factors associated with these illnesses, and their health care utilization behavior and attitudes., Methods: A cross-sectional questionnaire survey of 3355 participating secondary school students (response rate = 98%)., Results: Self-reported 3-month prevalences were obtained for cough/cold/influenza (55.2%), digestive disorders (34.6%), accidental injuries (29.5%), headache/dizziness (23.6%), chronic anxiety/insomnia (20.1%), skin problems (9.5%), asthma (3.8%), liver disease (1.3%), and menstrual pain (13.8% of female students). Self-perceived poor health, smoking, and alcohol consumption were associated with many of these illnesses. Treatment choice depended on the illness suffered (e.g., most students with respiratory problems consulted medical practitioners, whereas most with chronic anxiety/insomnia did not). Many students lacked trust in their doctors, doctor-shopped, relied heavily on self-medication, did not comply with prescribed treatments, would not seek help about medical problems, felt they had insufficient access to health information, and wanted confidential health care., Conclusions: This study examined for the first time the common illnesses and health care utilization patterns of Hong Kong adolescents. Students with chronic anxiety/insomnia were much less likely to seek care, indicating a need for better education on mental health. Efforts to prevent smoking and alcohol consumption among adolescents need to be strengthened. The students' attitudes, poor compliance and help-seeking behaviors suggest suboptimal use of the health care system. Our findings are useful for international comparisons by medical practitioners, health care managers, and researchers.

Multiple mRNA isoforms are generated from Siat1, the gene encoding ST6Gal I (beta-galactoside alpha2,6-sialyltransferase, SiaT-1, ST6N, alpha2,6ST). These isoforms, transcriptionally initiated from a number of physically distinct promoter regions, differ only in the 5'-most untranslated region and share an identical ST6Gal I coding region. W16 cells, a spontaneous mutant from MDAY-D2, the highly metastatic murine lymphoid tumor cell line, is considerably less metastatic and exhibits significantly slower tumor growth characteristics [R. Takano, E. Muchmore, and J. W. Dennis (1994) Glycobiology 4, 665-674]. Takano et al. further reported that ST6Gal I mRNA in W16 is elevated 40-fold compared to the parental cells. Here, by means of 5'-RACE analysis, we demonstrate a heretofore undocumented ST6Gal I mRNA form expressed in W16 cells. This ST6Gal I mRNA contains a novel 5'-most untranslated region with 96% sequence similarity to the retroviral-like transposable element, intracisternal particle A (IAP). This observation suggests the notion that elevated ST6Gal I expression in W16 cells is the result of DNA rearrangement in the Siat1 locus. Atypical transcriptional activation of Siat1 is the result of this IAP transposition., (Copyright 1999 Academic Press.)

Sialoglycans on the cell surface of human colon cancer (HCC) cells have been implicated in cellular adhesion and metastasis. To clarify the role of N-acetylneuraminic acid (NeuAc) linked alpha2,3 to galactose (Gal) on the surface of HCC cells, we studied the intercellular adhesion of HCC cell lines expressing increasing NeuAcalpha2,3Gal-R. Our model system consisted of the HCC SW48 cell line, which inherently possesses low levels of cell surface alpha2,3 and alpha2,6 sialoglycans. To generate SW48 clonal variants with elevated cell surface NeuAcalpha2,3Gal-R linkages, we transfected the expression vector, pcDNA3, containing either rat liver cDNA encoding Galbeta1,3(4)GlcNAc alpha2,3 sialyltransferase (ST3Gal III) or human placental cDNA encoding Galbeta1,3GalNAc/Galbeta1,4GlcNAc alpha2,3 sialyltransferase (ST3Gal IV) into SW48 cells. Selection of neomycin-resistant clones (600 microgram G418/ml) having a higher percentage of cells expressing NeuAcalpha2,3Gal-R (up to 85% positive Maackia amurenis agglutinin staining compared with 30% for wild type cells) was performed. These ST3Gal III and ST3Gal IV clonal variants demonstrated increased adherence to IL-1beta-activated human umbilical vein endothelial cells (HUVEC) (up to 90% adherent cells compared with 63% for wild type cells). Interestingly, ST3Gal III and ST3Gal IV clonal variants also bound non-activated HUVEC up to 4-fold more effectively than wild type cells. Cell surface NeuAcalpha2,3Gal-R expression within the various SW48 clonal variants correlated directly with increased adhesion to HUVEC (r=0.84). Using HCC HT-29 cells, which express high levels of surface NeuAcalpha2,3Gal-R, addition of synthetic sialyl, sulfo or GalNAc Lewis X structures were found to specifically inhibit intercellular adhesion. At 1.0mM, NeuAcalpha2,3Galbeta1,3(Fucalpha1, 4)GlcNAc-OH and Galbeta1,4(Fucalpha1,3)GlcNAcbeta1,6(SE-6Galbeta1++ +, 3)GalNAcalpha1-O-methyl inhibited HT-29 cell adhesion to IL-1beta-stimulated HUVEC by 100% and 68%, respectively. GalNAcbeta1, 4(Fucalpha1,3)GlcNAcbeta1-O-methyl and GalNAcbeta1,4(Fucalpha1, 3)GlcNAcbeta1,6Manalpha1,6Manbeta1-0-C30H61, however, did not possess inhibitory activity. In conclusion, these studies demonstrated that cell surface NeuAcalpha2,3Gal-R expression is involved in HCC cellular adhesion to HUVEC. These specific carbohydrate-mediated intercellular adhesive events may play an important role in tumor angiogenesis, metastasis and growth control., (Copyright 1999 Academic Press.)

Multiple mRNA isoforms are generated from SIAT1, the gene encoding the beta-galactoside alpha 2,6-sialyltransferase (ST6Gal I, SiaT-1, ST6N, alpha 2,6ST). These isoforms are transcriptionally initiated from a number of physically distinct promoter regions. In human B-lymphocytic cells, two SIAT1 mRNA isoforms have been identified. In order to determine if additional SIAT1 mRNA isotypes exist, RNA from Louckes, a human cell line with the mature B-phenotype, was subjected to 5'-RACE analysis. In addition to the two previously characterized mRNA forms, three additional SIAT1 mRNA forms were identified. The new mRNA isoforms incorporate novel sequence blocks into their 5'-UT regions. The data strongly suggest that these novel sequence blocks originate from previously undocumented 5'-noncoding exons and are incorporated into mRNA by alternative splicing events and/or usage of additional transcriptional promoter regions. BLAST analysis reveals no similarity of these novel regions, Exons U, V, and W, to sequences in GenBank. The only exception is Exon V, which contains a portion of Alu, a repetitive element. The data suggest that two of these novel mRNA isotypes are likely to be minor components. However, one form may contribute significantly to the SIAT1 mRNA pool in Louckes cells.

Lipoprotein(a) (Lp(a)) is an independent marker of cardiovascular disease which is relatively unresponsive to treatment with most of the commonly prescribed lipid lowering drugs. Concentrations of Lp(a) increase after the menopause, and the primary aim of this study was to determine whether combined hormone replacement therapy was effective in lowering levels of Lp(a) in postmenopausal women. An open longitudinal study was conducted among 42 women who had undergone a spontaneous menopause and were attending the outpatient clinic of the Prince of Wales Hospital, Hong Kong. All subjects were treated with 2 mg oral estradiol daily and 5 mg medroxyprogesterone acetate for 12 days each calendar month. Fasting blood samples for lipoprotein measurement were taken before the commencement of treatment and at 6 and 12 months. Lp(a) levels showed a skewed distribution with a median value before treatment of 9.45 mg/dl (range 1.47-95.62 mg/dl). After 6 months, there was a reduction to 7.70 mg/dl (1.12-72.59 mg/dl) (P < 0.01), and after 12 months the median concentration was 7.14 mg/dl (0.63-69.23 mg/dl) (P < 0.001 0-12 months). There were also significant reductions in the concentrations of apo B from 116.13 to 111.62 mg/dl and LDL-C from 3.02 to 2.74 mmol/l (P < 0.05), plus a lowering of TC of borderline significance. Apo A-I increased from 162.56 to 173.35 mg/dl (P < 0.01), but there were no significant changes in HDL-C or the HDL-C subfractions. TC, LDL-C, apo B and TG concentrations were higher and HDL-C and HDL2-C concentrations were lower when blood was sampled during combined treatment with estrogen and progesterone than when estrogen was being taken alone. Levels of Lp(a) were also lower during the estrogen only phase of treatment, but none of these differences were statistically significant. This study demonstrates that combined cyclical hormone replacement therapy is effective in reducing concentrations of Lp(a). The trend towards a more atherogenic lipid profile during the combined phase of treatment suggests that attention should be given to the timing of blood sampling in future studies of this nature.

A role of alpha 2,6-linked sialic acid in the development of an invasive phenotype in colon cancer has been suggested by several observations but never conclusively demonstrated. An experimental model to clarify this tissue was established by the creation and characterization of a bank of cell lines that differ mainly, if not exclusively, in the degree of alpha 2,6-sialylation. Human colon cancer cell lines SW48 and SW948, normally unable to elaborate the alpha 2,6-sialyl linkage, were transfected with the beta-galactoside alpha 2,6-sialyltransferase (alpha 2,6ST) cDNA driven by the cytomegaloviral promoter and screened for cell surface alpha 2,6-sialylated sugar chains using fluorescein isothiocyanate-conjugated Sambucus nigra agglutinin (SNA-FITC). A panel of SNA-FITC-positive clones was established that expresses alpha 2,6ST activity of varying degrees. Only the SNA-FITC-positive recombinants express the 1.2 Kb mRNA predicted to be generated from the transfected sequence. No 4.3-4.7 Kb transcripts that are indicative of transcription from the native alpha 2,6ST gene were detected.

A striking biochemical alteration to the epithelium of the small intestine upon weaning is the loss of microvillar sialic acids. Antibody and cDNA probes to the beta-galactoside alpha 2,6-sialyltransferase (SiaT-1, EC 2.4.99.1) were used to characterize the expression of this sialyltransferase in the small intestine of suckling rats. SiaT-1 mRNA and protein in the intestinal epithelium are rapidly lost upon weaning, in agreement with the loss of mucosal sialic acids and general sialyltransferase activity. Developmental repression of SiaT-1 is manifested in a proximal to distal gradient; SiaT-1 mRNA and protein are lost first from the duodenum and persist the longest in the ileum. We have previously documented that SiaT-1 gene expression can be transcriptionally initiated from a number of distinct tissue-specific promoter regions. Here, by criteria of mRNA mobility on agarose gels, primer extension analysis, and differential Northern hybridization, we show that the promoter previously considered to be liver-specific is operative in SiaT-1 expression in the small intestine of suckling animals. Comparison of this SiaT-1 promoter region with promoter regions of other genes exhibiting dual intestine-hepatic tissue specificity revealed a number of striking sequence similarities. Regulatory implications and consequences of small intestinal SiaT-1 expression in suckling but not in weaned animals are discussed.

Two mongoloid patients with Hirschsprung's disease are presented. Mongoloid children who have severe constipation should be investigated for Hirschsprung's disease.

A probe generated from the coding sequence of the rat hepatic beta-galactoside alpha 2,6-sialyltransferase was used to screen a human cDNA library constructed of human submaxillary gland mRNA lambda gt-11. We report the isolation and characterization of a human cDNA, HSM-ST1, that is putatively the human homolog of the beta-galactoside alpha 2,6-sialyltransferase. The largest human clone contains a 1.3 kb cDNA insert and is predicted to encompass 75% of the coding sequence as well as a small portion of the 3' untranslated region. Comparative analysis of this insert with the rat hepatic alpha 2,6-sialyltransferase sequence indicates 79% nucleotide similarity between the two sequences in the predicted coding region. On the amino acid level, the degree of conservation is 86%. Substantial sequence similarity is observed in the 3'-untranslated region between the rat and human sequences as well. S1 nuclease analysis was performed to demonstrate the expression of HSM-ST1 transcripts in the human hepatoma cell line, HepG2, and in the human colonic adenocarcinoma cell lines, LS174T.

Previous in vivo studies using drugs that inhibit the N-glycosylation of proteins have demonstrated that newly synthesized N-linked glycoproteins are required for gastrulation in embryos of two species of sea urchins, Strongylocentrotus purpuratus and Arbacia punctulata. To understand the biochemical events regulating glycoprotein synthesis during gastrulation in S. purpuratus embryos, we examined the in vitro activities of enzymes catalyzing several of the early steps in N-linked glycoprotein synthesis. The activities of glycosyl transferases responsible for production of N,N-diacetylchitobiosylpyrophosphoryldolichol and glucosylphosphoryldolichol, two intermediates in the formation of oligosaccharylpyrophosphoryldolichol (the carbohydrate donor for N-glycosylation), were low but detectable in membranes from eggs. After fertilization these activities remained constant or increased slowly up to the blastula stage and thereafter increased rapidly at gastrulation. In agreement with these in vitro findings, in vivo labeling experiments revealed that the rate of incorporation of [3H]Man into oligosaccharylpyrophosphoryldolichol and into protein increased three- to fourfold prior to gastrulation and then slightly more at the prism stage. In contrast, in vitro activity of mannosylphosphoryldolichol synthase, another enzyme in the pathway of N-linked glycosylation, was maximal in membranes from egg and embryos in the early stages of development and declined prior to gastrulation. Furthermore, the level of this activity was at least 100-fold greater than that for enzymes involved in the formation of the chitobiosyl and glucosyl lipids. With the exception of mannosylphosphoryldolichol synthase activity, these data indicate that there is a general activation of the glycosylation apparatus before gastrulation in sea urchin embryos. Possible explanations for the decrease in mannosylphosphoryldolichol synthase activity are discussed.