Seroprevalence and risk factors for Helicobacter pylori infection in Greenlanders

BACKGROUND: In contrast to most populations worldwide, the incidence of gastric cancer increases among Inuit in Greenland. Contributing factors to this increase are unknown, but Helicobacter pylori may be involved. However, little is known regarding the epidemiology of H. pylori in Arctic communities. With the aim of determining age-specific prevalence, risk factors, and association with clinical conditions of H. pylori infection, we carried out a population-based study of H. pylori in Sisimiut, the second biggest town of Greenland. MATERIALS AND METHODS: A population-based sample of 685 persons had serum drawn that was analyzed for H. pylori IgG antibodies using enzyme-linked immunosorbent assay (ELISA). Risk factors analyses were carried out using multivariate logistic regression models. RESULTS: The seroprevalence was lowest among children aged 0-4 years (6%), but increased rapidly thereafter. In persons aged 15-87 years the seroprevalence had stabilized around 58%. Total number of children in household, number of older, but not younger, siblings and narrow age gap to closest older sibling were associated with H. pylori seropositivity. In contrast, number of adults in household and socioeconomic status did not influence serostatus. CONCLUSIONS: The age-specific prevalence pattern in Greenland is intermediate between that of developing and developed countries. The risk factor pattern indicates crowding and older siblings in particular to be key elements in risk of infection.     

The blood group B type-4 heptaglycosylceramide is a minor blood group B structure in human B kidneys in contrast to the corresponding A type-4 compound in A kidneys. Structural and in vitro biosynthetic studies

Blood group A glycolipid antigens have been found based upon at least four different core saccharides (types 1 to 4). The biological significance of this structural polymorphism is not known, although the successful outcome of transplantations of blood group A₂ kidneys to blood group O individuals have been partly explained by the low expression of A type-3 and -4 chain glycolipid antigens in A₂ kidneys. If graft rejection due to ABO incompatibility is, in any way, correlated to the expression of type-3 and -4 chain blood group glycolipids, it is of interest to identify possible blood group B structures based on these core saccharides. In a non-acid glycosphingolipid fraction isolated from human blood group B kidneys, mass spectrometry, high-temperature gas chromatography-mass spectrometry and probing of thin-layer chromatograms with Galα1–4Gal-specific Escherichia coli and monoclonal anti-B antibodies provided evidence for minute amounts of Gaα1–3(Fucα1–2)Galβ-HexNac-Galα1–4Galβ-Hex-Ceramide structure consistent with a B type-4 chain heptaglycosylceramide. In contrast, blood group A kidneys have the corresponding A type-4 chain heptaglycosylceramide as the predominant glood group A glycolipid. No, or very low activity of the blood group B gene enzyme on the type-4 chain blood group H hexaglycosylceramide precursor was found by biosynthetic experiments in vitro, which migh explain the low expression of type-4 chain blood group heptaglycosylceramides in human blood group B kidneys.     

Seminal fluid excretion of cytomegalovirus related to immunosuppression in homosexual men.

Seminal fluid samples from 84 Danish homosexual men were successfully cultured to determine the prevalence of cytomegalovirus excretion. Ten (15%) out of 66 men positive for the antibody were found to be excreting the virus. Although the proportion excreting was inversely related to age (p less than 0.01), three men aged over 30 and with many years of homosexual experience excreted the virus. In addition, a 50 year old man with Kaposi''s sarcoma excreted the virus. A further study of the ratio of T cell helpers to suppressors in the men aged over 30 and a series of age matched non-excreting homosexual control or heterosexual men showed that those excreting cytomegalovirus in their seminal fluid had statistically lower ratios (all less than 0.77) than the controls (p less than 0.05). Excretion of cytomegalovirus may be related to re-emergence of latent infection in immunosuppressed homosexual men.     

Use of a β1 Integrin-deficient Human T Cell to Identify β1 Integrin Cytoplasmic Domain Sequences Critical for Integrin Function

T cell activation rapidly and transiently regulates the functional activity of integrin receptors. Stimulation of CD3/T cell receptor, CD2 or CD28, as well as activation with phorbol esters, can induce within minutes an increase in β1 integrin-mediated adhesion of T cells to fibronectin. In this study, we have produced and utilized a mutant of the Jurkat T cell line, designated A1, that lacks protein and mRNA expression of the β1 integrin subunit but retains normal levels of CD2, CD3, and CD28 on the cell surface. Activation-dependent adhesion of A1 cells to fibronectin could be restored upon transfection of a wild-type human β1 integrin cDNA. Adhesion induced by phorbol 12-myristate 13-acetate-, CD3-, CD2-, and CD28 stimulation did not occur if the carboxy-terminal five amino acids of the β1 tail were truncated or if either of two well-conserved NPXY motifs were deleted. Scanning alanine substitutions of the carboxy-terminal five amino acids demonstrated a critical role for the tyrosine residue at position 795. The carboxy-terminal truncation and the NPXY deletions also reduced adhesion induced by direct stimulation of the β1 integrin with the activating β1 integrin-specific mAb TS2/16, although the effects were not as dramatic as observed with the other integrin-activating signals. These results demonstrate a vital role for the amino-terminal NPXY motif and the carboxy-terminal end of the β1 integrin cytoplasmic domain in activation-dependent regulation of integrin-mediated adhesion in T cells. Furthermore, the A1 cell line represents a valuable new cellular reagent for the analysis of β1 integrin structure and function in human T cells.     

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Ohne Zusammenfassung     

Health Centre X-ray Unit

An analysis of the types and numbers of x-ray films requested in the first year of a health centre x-ray unit showed that chest films represented the largest proportion of these. The unit is most valuable when it is inmediately available to the patient and general practitioner at the time of consultation, and thus it should be open for at least five sessions per week. The likely referral rate for the health centre x-ray unit is 84 patients per 1,000 at risk, and a unit functioning for five sessions a week can examine 60 patients during that time. This minimum of five sessions would be fully used by a population of 30,000 patients. The running costs were found to be about the same as those of a hospital x-ray unit.     

Sexual transmission of hepatitis C virus: cohort study (1981-9) among European homosexual men.

OBJECTIVE--To determine the prevalence, incidence, and persistence of positivity for antibodies to hepatitis C virus (anti-HCV) and the potential for sexual transmission of the virus. DESIGN--A cohort analysis covering 1981-9 comparing estimated cumulative incidences of and seroconversion rates for anti-HCV with those of hepatitis B core antibody (anti-HBc) and antibodies to the human immunodeficiency virus (anti-HIV). SETTING--Copenhagen and Aarhus, Denmark. SUBJECTS--259 Male members of a Danish homosexual organisation. MAIN OUTCOME MEASURES--Correlations of prevalence and incidence with a wide range of sexual lifestyle variables. RESULTS--Only four (1.6%) subjects were positive for anti-HCV in 1981. The estimated cumulative incidence of positivity for anti-HCV was 4.1% in 1984 (seroconversion rate during 1981-4 (2.5%)) and remained at 4.1% in 1989 (seroconversion rate nil during 1984-9). In contrast, positivity for anti-HBC rose from 44.0% in 1981 to 52.7% in 1984 (seroconversion rate 15.5%) and 58.8% in 1989 (seroconversion rate 12.9%), and that for anti-HIV rose from 8.8% to 24.0% (seroconversion rate 16.7%) and 30.1% (seroconversion rate 8.0%) respectively. Three anti-HCV positive patients seroreverted three to five years later. None of the anti-HCV positive subjects had had a transfusion and only one gave a past history of intravenous drug use. Variables in sexual lifestyle correlated with the presence of anti-HBc but not with that of anti-HCV. CONCLUSIONS--In contrast with hepatitis B virus and HIV, sexual transmission of hepatitis C virus seems to be a rare event. Furthermore, antibodies to the virus may become undetectable after several years.     

Strategy for the investigation of O-linked oligosaccharides from mucins based on the separation into neutral, sialic acid- and sulfate-containing species

A method for the separation of O-linked oligosaccharides into neutral, sialic acid-containing and sulfated species was applied to oligosaccharides released by alkaline borohydride from mucin glycopeptides from porcine small intestine. The released mixture of reduced oligosaccharides was applied to an anion exchange column, and the neutral oligosaccharides were collected as the unretarded fraction. A mixture of dimethyl sulfoxide and iodomethane was passed through the column to convert the sialic acid-containing oligosaccharides into methyl esters that were eluted and converted to methyl amides by methyl amine. Finally the sulfated oligosaccharide fraction was eluted with salt. The neutral and the derivatized sialic acid-containing oligosaccharides were analysed by gas chromatography-mass spectrometry after permethylation and the sulfated oligosaccharide fraction was analysed by high performance anion exchange chromatography.Abbreviations GC gas chromatography - GC/MS gas chromatography-mass spectrometry - HPAEC-PAD high performance anion exchange chromatography-pulsed amperometric detection - Hex hexose - HexNAc N-acetyl hexosamine - HexNAcol N-acetyl hexosaminitol - Fuc Fucose - NeuAc N-acetyl neuraminic acid - NeuGc N-glycolyl neuraminic acid     

Seroepidemiology of HTLV-III antibody in Danish homosexual men: prevalence,transmission, and disease outcome.

Sera taken from 250 Danish homosexual men in December 1981 as part of a prospective study of the acquired immunodeficiency syndrome (AIDS) were examined for the presence of HTLV-III antibody with an enzyme-linked immunosorbent assay. Antibody was present in 22 (8.8%) of the men. Seropositivity was most strongly associated with sexual exposure to men in the United States (relative risk 3.5; p less than 0.007). Increased frequency of anal receptive intercourse was also independently associated with seropositivity (p less than 0.05), but age, years of homosexual experience, number of homosexual partners, and use of nitrite inhalant were not independent risk factors. The frequency of seroconversion from absence to presence of HTLV-III antibody appeared to be about 1% a month in this community during December 1981 to February 1983. Of the 22 men who were originally seropositive, two (9%) subsequently developed AIDS as defined by the Centre for Disease Control and two (9%) others the AIDS related complex. Blood was taken in addition from two of the men to develop AIDS earliest in Denmark (diagnosed 1981) at the same time as the initial survey in 1981; both were seropositive. The spread of HTLV-III from high to low risk areas and the subsequent appearance of illnesses related to AIDS in the seropositive group support the hypothesis that HTLV-III is causally related to the development of AIDS.