Mental distress and its associations with behavioral outcomes during the COVID-19 pandemic: a national survey of Chinese adults.

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.

Tumorigenic potential is restored during differentiation in fusion-reprogrammed cancer cells.

Detailed understanding of the mechanistic steps underlying tumor initiation and malignant progression is critical for insights of potentially novel therapeutic modalities. Cellular reprogramming is an approach of particular interest because it can provide a means to reset the differentiation state of the cancer cells and to revert these cells to a state of non-malignancy. Here, we investigated the relationship between cellular differentiation and malignant progression by the fusion of four independent mouse cancer cell lines from different tissues, each with differing developmental potentials, to pluripotent mouse embryonic stem (ES) cells. Fusion was accompanied by loss of differentiated properties of the four parental cancer cell lines and concomitant emergence of pluripotency, demonstrating the feasibility to reprogram the malignant and differentiative properties of cancer cells. However, the original malignant and differentiative phenotypes re-emerge upon withdrawal of the fused cells from the embryonic environment in which they were maintained. cDNA array analysis of the malignant hepatoma progression implicated a role for Foxa1, and silencing Foxa1 prevented the re-emergence of malignant and differentiation-associated gene expression. Our findings support the hypothesis that tumor progression results from deregulation of stem cells, and our approach provides a strategy to analyze possible mechanisms in the cancer initiation.

Spin coupling and orbital angular momentum quenching in free iron clusters.

Magnetic spin and orbital moments of size-selected free iron cluster ions Fe{n}{+} (n=3-20) have been determined via x-ray magnetic circular dichroism spectroscopy. Iron atoms within the clusters exhibit ferromagnetic coupling except for Fe{13}{+}, where the central atom is coupled antiferromagnetically to the atoms in the surrounding shell. Even in very small clusters, the orbital magnetic moment is strongly quenched and reduced to 5%-25% of its atomic value while the spin magnetic moment remains at 60%-90%. This demonstrates that the formation of bonds quenches orbital angular momenta in homonuclear iron clusters already for coordination numbers much smaller than those of the bulk.

Psychological factors in association with uptake of voluntary counselling and testing for HIV among men who have sex with men in Hong Kong.

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.

Cyclooxygenase inhibitors differentially modulate p73 isoforms in neuroblastoma.

p73 encodes multiple functionally distinct isoforms. Proapoptotic TAp73 isoforms contain a transactivation (TA) domain, and like p53, have tumor suppressor properties and are activated by chemotherapies to induce cell death. In contrast, antiapoptotic DeltaNp73 isoforms lack the TA domain and are dominant-negative inhibitors of p53 and TAp73. DeltaNp73 proteins are overexpressed in a variety of tumors including neuroblastoma. Thus, identification of drugs that upregulate TAp73 and/or downregulate DeltaNp73 represents a potential therapeutic strategy. Here, we report that cyclooxygenase (COX) inhibitors induce apoptosis independent of p53, and differentially modulate endogenous p73 isoforms in neuroblastoma and other tumors. COX inhibitor-mediated apoptosis is associated with the induction of TAp73beta and its target genes. COX inhibitors also downregulate the alternative-spliced DeltaNp73(AS) isoforms, Deltaexon2 and Deltaexon2/3. Furthermore, forced expression of DeltaNp73(AS) results in diminished apoptosis in response to the selective COX-2 inhibitor celecoxib. Celecoxib-mediated downregulation of DeltaNp73(AS) is associated with decreased E2F1 levels and diminished E2F1 activation of the p73 promoter. These results provide the first evidence that COX inhibitors differentially modulate p73 isoforms leading to enhanced apoptosis, and support the potential use of COX inhibitors as novel regulators of p73 to enhance chemosensitivity in tumors with deregulated E2F1 and in those with wild-type (wt) or mutant p53.

Knowledge about cataract, glaucoma, and age related macular degeneration in the Hong Kong Chinese population.

AIMS: Patients' knowledge and participation in their care are important in prevention of blindness from common eye diseases such as cataract, glaucoma, and age related macular degeneration (AMD). The aim of this study was to measure knowledge of these conditions in the Hong Kong Chinese population. METHODS: Subjects aged 40 and above in the Shatin district of Hong Kong were randomly selected as part of a larger study of causes of adult visual loss. The subjects received eye examinations in which the primary cause of visual disability was recorded. The respondents were asked by trained interviewers in a standardised fashion about their knowledge of cataract, glaucoma, and AMD. Their answers were rated for accuracy by a senior ophthalmologist. RESULTS: Out of the 2538 eyes examined, 7.0% had visual acuity less than 6/18. Fully 69.6% of the visual disability for those aged 60 or above was caused by cataract, AMD, or glaucoma. Awareness of cataract in particular was high, in that over 90% of respondents had heard of it. However, only 22.9% of them could describe cataract symptoms correctly, and these percentages were even lower in glaucoma (10.2%) and AMD (<1%). Over 40% of subjects did not know that surgery was an appropriate treatment for cataract. CONCLUSION: This sample of the Hong Kong Chinese population had limited knowledge of common eye diseases. Educational programmes to enhance public awareness may be needed to improve the effectiveness of health promotion and thus prevent unnecessary blindness.

Size-dependent magnetism of deposited small iron clusters studied by x-ray magnetic circular dichroism.

The size-dependent magnetic properties of small iron clusters deposited on ultrathin nickel films have been studied with circularly polarized synchrotron radiation. With the use of sum rules, orbital and spin magnetic moments have been extracted from x-ray magnetic circular dichroism spectra. The ratio of orbital to spin magnetic moments varies considerably with cluster size, reflecting the dependence of magnetic properties on cluster size and geometry. These variations can be explained in terms of enhanced orbital moments in small clusters.

Mouse ST6Gal sialyltransferase gene expression during mammary gland lactation.

The sialyltransferase ST6Gal mediates the biosynthetic addition of sialic acid, via an alpha2,6 linkage, to the nonreducing end of terminal lactosamine structures. Transcription of the murine ST6Gal gene, Siat1, is regulated by the selective use of multiple promoters in a tissue- and development-specific manner. Here we report that Siat1 mRNA expression is dramatically elevated in lactating (relative to virgin) mouse mammary gland. The predominant ST6Gal mRNA species expressed in lactating mammary gland is a heretofore undocumented isoform containing a unique 5'-untranslated region originating from the mouse Siat1 genetic region, now defined as Exon L, residing 549-bp 5' of the previously characterized Exon X(2). Thus, the novel ST6Gal mRNA form initiates transcription from the region designated as p4 and incorporates the unique sequence from Exon L in 5'-juxtaposition to commonly shared sequences encoded on Exon I to Exon VI. In contrast, cells derived from virgin mammary tissue expressed only the housekeeping mRNA form derived from p3, with Exon O sequence preceding Exons I-VI. The Exon L-containing, p4 class of mRNA was also not detected in a survey of eight other mouse tissues. Previous reports have indicated a strong correlation between mammary cancers and elevated ST6Gal expression in rats and in human patients. However, we uncovered neither elevated expression of ST6Gal mRNA nor appearance of p4 class in mouse breast carcinomas experimentally induced by transformation with the polyoma-middle T oncogene. A number of established breast carcinoma cell lines were also examined, with ST6Gal mRNA and activity generally low. Moreover, with the exception of the Shionogi cell line, p4 class of ST6Gal mRNA was not expressed in any of the mouse breast carcinoma specimens examined. Taken together, our data indicate that murine ST6Gal induction during lactation is achieved by de novo recruitment of a normally silent promoter. Furthermore, the data provide no support for elevated Siat1 expression on the mRNA level in association with murine mammary gland carcinogenesis. With the single exception of the Shionogi cell line, the p3 class remains the predominant ST6Gal mRNA expressed in all other murine mammary carcinoma cells examined.

Studies on common illnesses and medical care utilization patterns of adolescents in Hong Kong.

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.

Overexpression of the alpha2,6-sialyltransferase, ST6Gal I, in a low metastatic variant of a murine lymphoblastoid cell line is associated with appearance of a unique ST6Gal I mRNA.

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.

Hepatic acute phase induction of murine beta-galactoside alpha 2,6 sialyltransferase (ST6Gal I) is IL-6 dependent and mediated by elevation of exon H-containing class of transcripts.

Hepatic expression of CMP-NeuAc:Gal beta 1,4GlcNAc alpha 2,6-sialyltransferase (ST6Gal I) is induced as part of the acute phase response in mammals by mechanisms that remain poorly understood. Previous work suggests that murine liver ST6Gal I mRNA contains an additional and novel region that is not found on ST6Gal I mRNA from human HepG2 hepatoma cells and from rat liver. This novel region, residing 5' of the common Exon I sequence, is encoded by a discrete upstream exon, Exon H. Here we provide evidence that the Exon H-containing transcript is the murine counterpart of the human and rat ST6Gal I mRNAs transcribed from the hepatic-specific promoter, P1. Exon H-containing ST6Gal I mRNA is expressed in all three mice strains examined: balb/c, C57B46, and 129Sv. Furthermore, murine RNA tissue survey indicates that presence of Exon H-containing transcripts is restricted to the liver. When mice are subjected to subcutaneous injection of turpentine to elicit the hepatic acute phase response, greater than 4-fold elevation in liver ST6Gal I mRNA was observed. Consistent with the view that Exon H-containing transcripts is regulated by the murine P1 promoter, 5'-RACE analysis indicates that the majority of these transcripts contains the Exon H sequence. This is consistent with the view that Exon H-containing transcripts are regulated by the murine P1 region. To assess the mechanism of ST6Gal I response in the hepatic acute phase reaction, mice harboring lesions in both alleles of the IL-6 gene were examined. IL-6(-/-) animals expressed normal levels of ST6Gal I mRNA in liver, with Exon H-containing transcripts remaining the predominant mRNA isoform. However, hepatic ST6Gal I is not elevated upon turpentine injection in the IL-6(-/-) animals. These results indicate that ST6Gal I induction in mouse liver during the acute phase reaction is mediated predominantly by the IL-6 pathway, and results in the induction of the Exon H-containing class of ST6Gal I mRNA that is specific to the liver.

Transcription of the beta-galactoside alpha2,6-sialyltransferase gene (SIAT1) in B-lymphocytes: cell type-specific expression correlates with presence of the divergent 5'-untranslated sequence.

A single gene, SIAT1, encodes ST6Gal I, the sialyltransferase that mediates transfer of alpha2,6-linked sialic acids to Galbeta1, 4GlcNAc termini of N-linked glycoproteins. In vivo, multiple SIAT1 mRNA forms, differing only in the 5'-untranslated region, are expressed in a tissue-specific manner. This mRNA heterogeneity has been attributed, at least in part, to transcription from a number of physically distinct promoter regions. In mature B-lymphocytes, SIAT1 transcription initiates at P2, a regulatory region known to function only in B-lineage cells. Bacterial chloramphenicol acetyltransferase (CAT) under the control of the P2 region encompassing 415 bp 5'- and 125 bp 3' of the transcriptional initiation site is efficiently expressed in Louckes, a mature B-lymphoblastoid cell line. In contrast, CAT expression in Reh, a T-null/B-null precursor line, and in HepG2, a hepatoma line, are 14-fold and >25-fold less than in Louckes, respectively. The data is consistent with the presence of cis -acting regulatory elements residing both 5' and 3' of the P2 transcriptional initiation site. At least 370 bp of 5'-flanking sequence, coinciding with the inclusion of AP2 and NF-kappaB sites, is necessary for high level expression in Louckes. Exon sequences 3' of the transcription start site are also important for expression. A segment from(+)32 to(+)125 (position(+)1 is transcription start site) is capable of exerting promoter-like activity in Louckes, but not in Reh or HepG2. CAT expression by P2 is negligible in Reh cells. However, enhanced CAT activity is not accompanied by elevated mRNA levels. This observation is consistent with the relief of translational restraints imposed by the(+)32 to(+)125 region. Together, the data demonstrate that efficient and cell-specific transcription regulation in mature B lymphocytes is contained in a 495 bp P2 segment that is comprised of 370 bp of 5'-flanking region and 125 bp of transcribed region of Exon X.

Prevalence and correlates of physical abuse in Hong Kong Chinese adolescents: a population-based approach.

OBJECTIVE: The objectives were to estimate the prevalence and correlates of physical abuse-related outcomes in the family setting in Hong Kong's adolescent population. METHOD: A cross-sectional study design was used. A randomly selected sample of 3,355 secondary school students in Kwai Tsing District of Hong Kong was surveyed. The response rate was 98%. RESULTS: The prevalence rates of corporal punishment, being beaten by parents for no apparent reason, being beaten to injury by family members in the past 3 months and any one of the above three were 4.9% (95% CI, 4.2% to 5.6%), 2.0% (95% CI, 1.5% to 2.5%), 1.1% (95% CI, .98% to 1.2%) and 6.6% (95% CI, 5.7% to 7.5%), respectively. Students who had experienced the above physical abuse-related outcomes were at a significant disadvantage for a wide range of morbidity indicators, including self-perceived bad health, anxiety and stress, somatic illnesses (such as asthma and epigastric pain), injuries and accidents, and hospitalization. They were more likely to have poor familial relations and coping skills, and to take up habits which potentially put their health at risk, such as smoking, alcohol consumption, and fighting with others. CONCLUSIONS: Our prevalence estimates of physical abuse in the family setting for a student population in Hong Kong is an improvement over previous local estimates of physical abuse occurrence, which were mainly based on case notifications and clinical samples. The results also show that the abused adolescents are growing up in an environment filled with physical, psychological, and familial adversities.

Differential expression of the hepatic transcript of beta-galactoside alpha2,6-sialyltransferase in human colon cancer cell lines.

The activity of beta-galactoside alpha2,6-sialyltransferase (ST6Gal.1), the enzyme responsible for the addition of sialic acid in alpha2,6-linkage to N-acetyllactosaminic (Gal beta1,4GlcNAc) units of glycoconjugates, is increased in the vast majority of colon cancer specimens, and a positive correlation with an invasive phenotype has been suggested by several studies. In many tissues, ST6Gal.1 is regulated mainly at the transcriptional level through the use of different cell-specific promoters which generate transcripts differing in their 5'-untranslated regions. With the aim of understanding the molecular bases of the increased ST6Gal.1 expression in colon cancer, we investigated the expression of mRNA species in colon cancer cell lines and the relationship with enzyme activity and extent of alpha2,6-sialylation of cell glycoproteins. All cell lines examined express the form containing the 5'-untranslated exons Y and Z, typical of the "basal" expression of the gene, while others express also the liver transcript. This indicates that colon cancer cell lines can be grouped according to expression of the liver transcript of ST6Gal.1. The cell lines expressing only the Y+Z form display, in general, a lower activity:mRNA ratio, which might indicate reduced translational efficiency. The level of alpha2,6-sialylation of cell glycoproteins, as determined by reactivity with the Sambucus nigra lectin, is closely associated with the level of enzyme activity.

Tarsal tunnel syndrome: a review of the literature.

Tarsal tunnel syndrome is an uncommon clinical entity. This article will review the published reports on tarsal tunnel syndrome with respect to its anatomy, cause, pathophysiology, clinical presentation, diagnosis, treatment, and results of treatment in an attempt to improve understanding of this problem.

Cell surface n-acetylneuraminic acid alpha2,3-galactoside-dependent intercellular adhesion of human colon cancer cells.

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.

Stigmata of hemorrhage in bleeding peptic ulcers: an interobserver agreement study among international experts.

BACKGROUND: Stigmata of hemorrhage predict rebleeding and outcome of patients with bleeding peptic ulcers. There are variabilities in reported incidences of stigmata and their respective rebleeding risks. We sought to study the interobserver agreement among experts. METHODS: Between June 1994 and July 1994, 100 consecutive patients with bleeding peptic ulcers underwent videoendoscopy within 24 hours of their admissions. An edited videotape of these ulcers was compiled and sent to an international panel of 14 experts. They independently rated these ulcers exclusively into one of the six categories: spurting, oozing, nonbleeding visible vessel, adherent clot, flat pigmented spot, or clean based. Agreement between any two experts was expressed by a kappa estimate (kappa). Agreements over individual stigmata and a composite kappa estimate (kappa(w)) signifying overall agreement were also computed. RESULTS: Out of the possible 91 pairwise kappa estimates among 14 experts, 35 (38.5%) were less than or equal to 0.40, indicating poor agreement. None of the kappa estimates was greater than 0.75. Composite kappa estimates for individual stigmata were as follows: spurting kappa = 0.664, oozing kappa = 0.420, nonbleeding visible vessel kappa = 0.342, adherent clot kappa = 0.426, flat pigmented spot kappa = 0.393, and clean-based ulcer kappa = 0.371. The weighted kappa estimate was 0.426. CONCLUSION: Agreement between experts was poor in more than a third of occasions. Although the overall interobserver agreement was fair (0.4 < kappa < 0.75), agreements for nonbleeding visible vessels, flat pigmented spots, and clean-based ulcers were poor.

Expression of beta-galactoside alpha 2,6-sialyltransferase does not alter the susceptibility of human colon cancer cells to NK-mediated cell lysis.

The extent of processing of N-linked oligosaccharides and the sialylation of the target cell membranes has been positively correlated with resistance to lysis mediated by NK cells, but a conclusive evidence has never been reached. Colon cancer tissues express an increased activity of beta-galactoside alpha 2,6-sialyltransferase (EC 2.4.99.1, alpha 2,6ST), which catalyzed the addition of sialic acid in alpha 2,6-linkage to Gal beta 1,4GlcNAc (N-acetyllactosamine) sequences of glycoprotein N-linked chains. The resulting increased level of membrane alpha 2,6-sialylation appears to be related with a more invasive behavior of cancer cells. This phenomenon may depend on a decreased sensitivity of colon cancer cells to NK cells. To obtain conclusive evidence on the role played by sialylation of N-linked chains in determining the target cell susceptibility to NK-mediated lysis, human colon cancer cell lines not expressing sialyltransferases acting on N-linked chains were transfected with a rat alpha 2,6ST cDNA. Stable transfectants expressed different levels of alpha 2,6ST activity, were reactive with the Sambucus nigra lectin, specific for alpha 2,6-linked sialic acid, and compared with control transfectants, showed a remarkable decrease in the number of unsubstituted Gal beta 1,4GlcNAc terminal sequences. The NK susceptibility of these clones was found to be identical to that of control transfectants, either when unstimulated- or IL-2-stimulated lymphocytes were used as effectors. Neuraminidase treatment of target cells does not result in significant changes to NK susceptibility. Our data demonstrate that sialic acid alpha 2,6-linked to N-linked chains of target cell glycoproteins does not play a major role in recognition of the target by human NK cells.

The relationship between upper gastrointestinal hemorrhage and drug use: a case control study.

The relationship between upper gastrointestinal hemorrhage and drug use was studied in 251 Chinese patients (179 men, 72 women) admitted to the Prince of Wales Hospital, Hong Kong, and control subjects matched for age and sex. There was a highly significant difference between the cases and control subjects in the use of NSAIDs (odds ratio 14.0, p < 0.00001), ulcer healing drugs (odds ratio 12.5, p < 0.00001), and Chinese proprietary medicines (odds ratio 16.0, p < 0.00001). There was also a significant difference in the use of analgesics (odds ratio 14.0, p = 0.001), paracetamol (odds ratio 2.5, p = 0.01), antacids (odds ratio 2.7, p < 0.001) and unknown drugs (odds ratio 4.7, p < 0.001). Cases also differed from control subjects regarding the use of tobacco (odds ratio 2.3, p < 0.001) and alcohol (odds ratio 1.7, p = 0.02), and the presence of peptic ulcer symptoms (odds ratio 29.8, p < 0.00001). Significantly more control subjects than cases were receiving aspirin, cardiovascular drugs, bronchodilators, oral hypoglycemic drugs/lipid-lowering drugs, and anticonvulsants/hypnotics, due to the inevitable differences in disease pattern between the 2 groups. NSAID use was a major factor associated with upper gastrointestinal hemorrhage from primarily peptic ulcers. Differences in the use of other drugs may reflect variations in disease patterns between cases and controls, the common practice of self-medication in Hong Kong, and the concomitant use of NSAIDs and ulcer healing drugs/antacids.