Glycocalyx modulation is a physiological means of regulating cell adhesion

Here we present experimental evidence that phagocytic cells use modulation of specific components of their glycocalyx to regulate their binding capacity. Particles coated with antibodies specific for the CD32 medium affinity IgG receptor were driven along human monocytic THP-1 cells (expressing CD32) in a flow chamber operated at low shear rate. Surprisingly, only minimal adhesion was observed. However, when cells were activated by exposure to fibronectin-coated surfaces and/or soluble γ interferon, adhesion efficiency was dramatically increased, whereas the apparent glycocalyx thickness displayed 20% decrease, and the surface density of CD43/leukosialin carbohydrate epitopes displayed 30–40% decrease on activated cells. The existence of a causal link between adhesion increase and glycocalyx alteration was strongly supported by the finding that (i) both phenomena displayed similar kinetics, (ii) an inverse relationship between THP-1 cell binding capacity and glycocalyx density was demonstrated at the individual cell level, and (iii) adhesion enhancement could not be ascribed to an increased binding site density or improved functional capacity of activated cells. Additional experiments revealed that cell-to-particle adhesion resulted in delayed (i.e. more than a few minutes) egress of CD43/leukosialin from contact areas. Since the time scale of particle attachment was less than a second, surface mobility should not affect the potential of CD43 to impair the initial step of adhesion. Finally, studies performed with fluorescent lectins suggested that THP-1 cell activation and increased adhesive potential were related to a decrease of O-glysosylation rather than N-glycosylation of surface glycoproteins.

Refined-cereal intake and risk of selected cancers in italy

BACKGROUND

Although consumption of whole-grain foods seems to reduce the risk of several types of neoplasms, the potential influence of a diet rich in starches and refined grains is less clear.

OBJECTIVE

We studied the relation between the frequency of consumption of refined cereals (bread, pasta, or rice) and the risk of selected neoplasms.

DESIGN

This was an integrated series of case-control studies conducted in northern Italy between 1983 and 1993. The subjects were patients admitted to the major teaching and general hospitals in Milan and Pordenone with incident, histologically confirmed cancers: 343 with cancer of the oral cavity and pharynx, 94 with cancer of the esophagus, 146 with cancer of the larynx, 745 with cancer of the stomach, 955 with cancer of the colon, 625 with cancer of the rectum, and 428 with cancer of the thyroid. The control subjects were 3526 patients admitted to the same network of hospitals for acute nonneoplastic conditions unrelated to long-term modification of diet. Odds ratios (ORs) for consecutive tertiles of refined-cereal consumption were computed after allowance for sociodemographic variables, education, smoking status, alcohol consumption, body mass index, and consumption of fruit, vegetables, and whole-grain foods.

RESULTS

The ORs for the highest tertile of refined-cereal intake were 1.6 for cancer of the oral cavity, pharynx, esophagus, or larynx; 1.5 for stomach cancer; 1.5 for colon cancer; 1.3 for cancer of the rectum; and 2.0 for thyroid cancer. The trends in risk were significant for all neoplasms considered.

CONCLUSION

Consumption of refined cereals was associated with an increased risk of cancers of the large bowel, the stomach, and other selected digestive and nondigestive sites.

Medical conditions in patients with pancreatic and biliary diseases: validity and agreement between data from questionnaires and medical records. PANKRAS II Study Group

The aims of the study were to assess the agreement between data from personal interviews and medical records on selected medical conditions, to evaluate the validity of each source of information, and to estimate the prevalence of these conditions in pancreatobiliary pathology. Between 1992 and 1995, 602 patients with pancreatobiliary diseases were included in the PANKRAS II Study. Information from interview and medical records was available in 88% of cases. The agreement between both data sources was poor only for cholecystitis and mental disorders. The validity of both sources of information was high or acceptable for all conditions except for cholecystitis. Prevalence of past medical conditions was similar to that reported previously and varied according to diagnosis, gender, age, educational level, and hospital of admission. Research aimed at assessing the prevalence of less common diseases should consider subject- and health-related factors in collecting information.

Body weight and risk of soft-tissue sarcoma

The relation between body mass (BMI) and soft-tissue sarcoma (STS) risk was evaluated in a case-control study from Northern Italy based on 217 incident STS and 1297 hospital controls. The risk of STS rose with BMI, with multivariate odds ratios of 3.49 (95% confidence interval (CI) 1.06-11.55) among men and 3.26 (95% CI 1.27-8.35) among women with a BMI > 30 kg m(-2) compared to those with BMI < or = 20 kg m(-2).

[Significance of segmentary reversal defects in the myocardial SPECT with 99mTC-tetrofosmin myocardial SPECT]

OBJECTIVES

To evaluate segmentary reverse defects (RD) (uptake higher in exercise than in rest) in 99mTc-tetrofosmin SPECT.

METHODS AND RESULTS

1,124 consecutive SPECT studies were reviewed and 80 (7%) segmentary RD were identified. Thirty-eight patients with RD attributed to artifact (extra cardiac uptake) were excluded. Thus, 42 patients (3.6%), 21 with and 21 without previous infarct, were studied. Thirteen out of 21 RD in patients without previous infarct corresponded to inferior region and 8 to the anterior region. In three out of 8 patients in whom the coronary angiography was performed, the coronary arteries were angiographically normal and 5 had stenosis of between 50% to 70% of coronary arteries corresponding to RD. Of the 21 RD in patients with previous infarct, the RD site corresponded to the same region of the necrosis (15 inferior and 6 anterior). All had viability criteria (uptake higher than 40% in more than 50% of the region) in rest uptake SPECT quantification. In nine out of 11 patients in whom a coronary angiography was carried out, patency of the artery responsible for the infarct was verified.

CONCLUSIONS

3.6% of segmentary RD, which were not attributed to the artifact, were observed in myocardial perfusion 99mTc-tetrofosmin SPECT studies. Half of these cases corresponded to regions without previous infarct and with normal coronary arteries or non-severe coronary stenosis. The remaining corresponded to regions with previous infarct and with viability criteria.

Hypertension and hormone-related neoplasms in women

The relation between hypertension and the risk of selected hormone-related neoplasms in women was investigated in a network of case-control studies conducted in Italy during 1983-1996. Cases were women younger than 75 years with histologically confirmed cancer of the breast (n=3406), endometrium (n=745), ovary (n=970), and thyroid (n=145). Controls were 3054 women admitted in the same geographic area for acute, nonneoplastic, non-hormone-related diseases. Odds ratios (ORs) of treated hypertension were computed after allowance for sociodemographic factors, smoking habits, alcohol consumption, parity, menopausal status, and body mass index (BMI) by means of unconditional logistic regression. The ORs were 1.2 (95% CI, 1.1 to 1.4) for breast cancer and 1.6 (95% CI, 1.3 to 1.9) for endometrial cancer, and the elevated ORs persisted after >/=5 years since diagnosis of hypertension. No significant association was observed for ovarian and thyroid cancer. For breast cancer, the association was apparently stronger at age 55 years or over and consequently after menopause. No appreciable effect modification was evident for endometrial cancer. Allowance for BMI did not explain the association of postmenopausal breast cancer and endometrial cancer with hypertension. The OR of postmenopausal breast cancer was 1.5 (95% CI, 1.1 to 2.0) in hypertensive women with BMI >/=30 kg/m(2) compared with normotensive women with BMI <25 kg/m(2). The corresponding figure for all endometrial cancers was 4.9 (95% CI, 3. 4 to 6.9). Even in the absence of a clear understanding of biological mechanisms, the definition of a role of hypertension on female hormone-related cancers can have relevant implications on individual risk assessment.

Cytokine profile of human bronchoalveolar macrophages and bronchial epithelial cells in response to inhalation particles of the cyclosporine derivative IMM 125

Administration of antiasthmatic drugs in the form of inhalation particles may alter the cytokine network in the airways, independently of their pharmacological actions. Changes induced by drugs not well tolerated may potentially contribute to the immunopathology of the disease, a strongly undesirable effect. In this study, cell viability assays and characterization of the cellular profile of cytokines and chemokines were performed in order to investigate the response of human bronchoalveolar macrophages and bronchial epithelial cells in culture to inhalation particles of the cyclosporine derivative IMM 125. Interleukin 1beta (IL-1beta), tumor necrosis factor alpha (TNFalpha), and IL-8 were assayed by enzyme-linked immunosorbent assay (ELISA) in the supernatants of bronchoalveolar macrophages, and RANTES, granulocyte--macrophage colony-stimulating factor (GM-CSF), and IL-8 in those of bronchial epithelial cells. Cells were studied both under basal and stimulated conditions (lipopolysaccharide and TNFalpha were used for activating macrophages and epithelial cells, respectively). The immunosuppressant FK 506 and the glucocorticoid Budesonide served as comparison. IMM 125 did not affect cell viability (except at high concentrations and long time periods). Moreover, IMM 125 did not induce an increase in the secretion of any of the cytokines and chemokines measured with respect to nontreated cells, except for a slight increase in IL-8, an effect that was also observed for FK 506, Budesonide, and inert latex particles, and was therefore regarded as nonspecific. Furthermore, IMM 125 significantly decreased the secretion of TNFalpha, IL-1beta by macrophages, and GM-CSF by epithelial cells, suggesting an antiinflammatory potential. In conclusion, the present in vitro results point to a good tolerance of human airways to IMM 125 inhalation particles.

Infection with a novel human DNA virus (TTV) has no pathogenic significance in patients with liver diseases

BACKGROUND/AIMS

A recently identified DNA virus, termed TT virus (TTV), has been associated with post-transfusional hepatitis, and a high prevalence of TTV infection in patients with acute or chronic liver disease of unknown etiology has been reported from Japan, but few data are available about TTV infection in other countries.

METHODS

Using hemi-nested-PCR amplification to detect TTV-DNA sequences in serum, we investigated TTV infection in blood donors and in patients with liver diseases of varied etiology.

RESULTS

The prevalence of TTV infection was 13.7% in blood donors (23/168), 18.6% in chronic hepatitis C (19/102), 28.6% in chronic hepatitis B (16/56), 29.9% in hepatocellular carcinoma (20/67), 9.1% in cryptogenic chronic liver disease (2/22) and 39.6% in fulminant hepatitis (19/48). The prevalence of TTV infection in patients with virus-induced or idiopathic fulminant hepatitis was similar. Comparison of TTV-infected and non-infected patients did not reveal significant differences concerning demographic, epidemiological or histopathological features. In patients with hepatitis C, response to interferon therapy was not related to TTV infection. Phylogenetic analysis of TTV isolates showed that at least three different types of TTV are present in Spain.

CONCLUSIONS

Our data suggest that TTV infection is frequent among blood donors and patients with acute liver disease. However, pathogenic effects associated with TTV infection were not observed.

[Laboratory diagnosis to dengue virus infections]

Currently, laboratory diagnosis of Dengue virus infection has a special importance because of its emerging character, showing a great geographic propagation of viral activity through out the American Continent. In general, the laboratory diagnosis of Dengue infections is similar to other human infecting viruses, the difference and difficulty of the process lies in the cross reaction activity with other flavivirus that can co-exist in the same region. The effectiveness of the diagnosis depends on the quality of the samples obtained, so it is absolutely necessary to monitor carefully the timing, conditions as well as the accompanying information during the gathering of the samples. The present article describes some of the serologic technics used in the diagnosis of dengue infection: hemaglutination inhibition, plaque reduction neutralization and IgM and IgG ELISA assays, in the same way it outlines the principles and importance of viral isolation and identification as well as the advantages of a new diagnosis technic like PCR.

Diet, alcohol, coffee and pancreatic cancer: final results from an Italian study

The relation between selected indicator foods, alcohol and coffee intake, and the risk of pancreatic cancer was evaluated in a case-control study conducted between 1983 and 1992 in northern Italy on 362 patients with histologically confirmed, incident cancers of the pancreas, and 1,552 controls in hospital for acute, non-neoplastic diseases. Odds ratios (ORs) for subsequent tertiles of intake were computed after allowance for sociodemographic factors and tobacco smoking. Pancreatic cancer risk was directly associated with consumption of meat (OR for the highest frequency tertile = 1.43), liver (OR = 1.43) and ham and sausages (OR = 1.64), and inversely with consumption of fresh fruit (OR = 0.59), fish (OR = 0.65) and olive oil (OR = 0.58). No appreciable association was found with coffee (OR = 1.21) and alcohol consumption (OR = 1.20). A summary score was derived by summing the six related food items; compared to the lowest level, the OR was 2.7 for the highest quintile, and the population attributable risk was 36% (95% confidence interval, 15-57%), indicating the scope of diet for the prevention of this common neoplasm in the Italian population.

Learning from case reports: diagnostic issues in an epidemiologic study of pancreatic cancer

Epidemiologic studies on exocrine pancreatic cancer show a large heterogeneity in diagnostic criteria applied to define "caseness." Reanalyses conducted after review of diagnostic information have yielded substantially different results than those based on more crude classifications of disease. During a multicenter prospective study on mutations in the K-ras gene in pancreatic and biliary diseases, hospital diagnoses from 602 patients were reviewed by a panel of experts. There were two main motivations to do so: a generic interest for the quality of the diagnostic data, and the anticipation that a firm diagnosis could be needed to assess whether patients whose tumors did not harbor the mutation were true negatives or false negatives. In addition, the review of diagnoses was helpful to minimize tissue misclassification, and it had a high educational value for clinicians and epidemiologists. This article illustrates why and how this was so through a brief presentation of the 10 most significant cases. With respect to selection and classification of subjects, the main issues that studies on pancreatic cancer need to address are the differential diagnosis of exocrine pancreatic cancer and pancreatitis, the differential diagnosis of exocrine pancreatic cancer and other abdominal tumors, and the use of survival as a hallmark of pancreatic cancer. In epidemiologic studies of pancreatic cancer, it is warranted that a panel of experts centrally reviews all the existing diagnostic evidence (cytohistological and other) of all patients, regardless of whether they have cytohistological confirmation and of their hospital discharge diagnosis.

[The use of ELISA and ultramicro ELISA in identifying a Coxsackie A9 strain isolated during the epidemic of neuropathy in Cuba]

During 1993 an outbreak of epidemic neuropathy characterized by 2 major clinical forms: the optic neuropathy and peripheral neuropathy, occurred in our country. Although the cause of the disease was considered to be multifactorial (mainly due to neurotoxic agents and to nutritional deficiency) an Enterovirus was isolated from the cerebrospinal fluid of a patient (strain 47/93, IPK) which was subsequently classified as a Coxsackie A9 virus (Cox A9) by the neutralization test, and using pools of Lim Benyesh Melnick (LBM) serum. Results obtained during the application of ELISA and ultramicro ELISA techniques for the identification of this agent from the supernatant of a culture of infected cells are reported, as well as the detection of antibodies to the strain found within populations with high and low incidence rates of the disease.

Delayed haemolytic transfusion reaction due to anti-M antibody

A female patient with delayed haemolytic transfusion reaction due to anti-M antibody is described. Diagnosis was based on laboratory evidence of haemolysis and on characteristic serological findings. Anti-M was detected in the recipient's serum 7 d after the last transfusion episode. This alloantibody had not been present in the pretransfusion serum. In addition, the direct antiglobulin test was positive on post-transfusion testing and the implicated antibody was eluted from post-transfused red cells. Delayed haemolytic transfusion reactions have long been recognized as a potential hazard of transfusion therapy, but such cases due to anti-M are extremely rare.

Females are responsible for ejection of cuckoo eggs in the rufous bush robin

Rufous bush robin, Cercotrichas galactotes, nests were experimentally parasitized in order to test which sex is responsible for egg ejection. We tested nests belonging to the same individuals (male, female or pair) in 2 consecutive years. Whether the eggs were rejected did not depend on environmental variables such as laying date and clutch size, and did not change between tests, when the two consecutive nests tested belonged to the same pair members, supporting the idea that some individuals reject odd eggs, while others accept them. The expected frequencies for rejection and acceptance, if females were the sex responsible for ejection behaviour, did not differ from the observed frequencies when the same female owned both the nests tested. However, the expected frequencies calculated for males as if they were the sex responsible differed from those observed, when the same male owned both the nests tested. A lower percentage of females than males changed ejection behaviour. These results show that female rufous bush robins are responsible for egg ejection. Copyright 1998 The Association for the Study of Animal Behaviour.

Adhesion-related glycocalyx study: quantitative approach with imaging-spectrum in the energy filtering transmission electron microscope (EFTEM)

Large polysaccharide molecules composing the glycocalyx have been shown to prevent cell adhesion. However, this process was not observed microscopically. Terbium labeling, combined with a new quantitative imaging method based on electron energy loss spectroscopy, allowed specific glycocalyx staining with excellent contrast. Image analysis enabled us to compare glycocalyx structure in free membrane areas and contacts between monocytic cells and bound erythrocytes. Apparent glycocalyx thickness, in contact areas, was half of the sum of glycocalyx thicknesses in free areas without label density increase. Ultrastructural immunogold localization of CD43 molecules, a major component of glycocalyx, was also demonstrated to be excluded from contact areas during adhesion. Thus, both approaches strongly suggest that some glycocalyx elements must exit from contact to allow binding of adhesion molecules.