Antibodies against platelet glycosphingolipids: detection in serum by quantitative HPTLC-autoradiography and association with autoimmune and alloimmune processes

In order to assess the importance of glycosphingolipids (GSL) in the immunology of the platelet, serum antibody binding to immobilized, purified platelet GSLs have been quantitatively measured via high- performance thin-layer chromatography (HPTLC), 125I-radio- immunolabeling, autoradiography, and densitometry. Thirteen neutral GSL bands were detected at Rf.03 through .64 (CHCl3-CH3OH-H2O, 65:25:4) after extraction and chromatography (DEAE-Sephadex and Bio-sil A). Both IgM and IgG serum antibody binding was determined for 50 subjects from four groups: normal blood donors (NBD, n = 18); leukemia patients with nonimmune thrombocytopenia (NIT, n = 10); patients with systemic lupus erythematosus (SLE, n = 10); and patients with chronic autoimmune thrombocytopenia (CATP, n = 12). The ABO typing of these 50 subjects also allowed correlation of serum antibody binding with A blood group antigen expression. These studies reveal: (1) anti-GSL binding at band .06 is associated with blood group A alloantigen expression for both IgG and IgM (P less than .0001) antibodies; (2) binding at bands .17, .27, and/or .46 is associated with general autoimmunity (SLE and CATP) for IgM (P less than .0001); (3) binding at bands .35 and/or .38 is associated with platelet-specific autoimmunity (CATP) for IgG and/or IgM (P less than .005); and (4) binding at bands .03, .20, .23, and/or .43 is frequently observed for sera from all groups. The platelet specificity of bands .35 and .38 was confirmed by comparative studies with human intestinal smooth muscle GSLs. Quantitation of the intensity of CATP-associated anti-GSL binding (86 +/- 88 mm2) is comparable to anti-A alloantigen binding (57 +/- 52 mm2). Two of the GSL bands associated with SLE and CATP appear to be the long-chain fatty-acyl forms of globotriaosyl ceramide (.27) and globotetraosyl ceramide (.17), which are the Pk and P blood group antigens, respectively. These studies indicate that neutral GSLs may be important antigens in both autoimmune and alloimmune processes involving the blood platelet.     

MGMT and MLH1 methylation in Helicobacter pylori-infected children and adults

AIM:To evaluate the association between Helicobacter pylori(H.pylori) infection and MLH1 and MGMT methylation and its relationship with microsatellite instability(MSI).METHODS:The methylation status of the MLH1 and MGMT promoter region was analysed by methylation specific methylation-polymerase chain reaction(MSPPCR) in gastric biopsy samples from uninfected or H.pylori-infected children(n = 50),from adults with chronic gastritis(n = 97) and from adults with gastric cancer(n = 92).MLH1 and MGMT mRNA expression were measured by real-time PCR and normalised to a constitutive gene(β actin).MSI analysis was performed by screening MSI markers at 4 loci(Bat-25,Bat-26,D17S250 and D2S123) with PCR;PCR products were analysed by single strand conformation polymorphism followed by silver staining.Statistical analyses were performed with either the χ 2 test with Yates continuity correction or Fisher’s exact test,and statistical significance for expression analysis was assessed using an unpaired Student’s t-test.RESULTS:Methylation was not detected in the promoter regions of MLH1 and MGMT in gastric biopsy samples from children,regardless of H.pylori infection status.The MGMT promoter was methylated in 51% of chronic gastritis adult patients and was associated with H.pylori infection(P < 0.05);this region was methylated in 66% of gastric cancer patients,and the difference in the percentage of methylated samples between these patients and those from H.pylori-infected chronic gastritis patients was statistically significant(P < 0.05).MLH1 methylation frequencies among H.pylori-infected and non-infected chronic gastritis adult patients were 13% and 7%,respectively.We observed methylation of the MLH1 promoter(39%) and increased MSI levels(68%) in samples from gastric cancer patients in comparison to samples from H.pylori-infected adult chronic gastritis patients(P < 0.001 and P < 0.01,respectively).The frequency of promoter methylation for both genes was higher in gastric cancer samples than in H.pylori-positiv     

Effects of particle exposure and particle-elicited inflammatory cells on mutation in rat alveolar epithelial cells

To investigate mechanisms underlying development of lung adenomas and carcinomas in rats exposed to poorly soluble particles the relationships between particle exposure, inflammation and mutagenesis in rat alveolar type II cells were characterized. Rats were exposed to saline or saline suspensions of 10 and 100 mg/kg of alpha-quartz, carbon black or titanium dioxide by intratracheal instillation. Fifteen months after exposure, bronchoalveolar lavage (BAL) cells were characterized as to number and type and lung histopathology performed. The alveolar type II cells were isolated and cultured in 6 thioguanine (6TG) containing media to select for mutation in the hprt gene. The potential contribution of lung inflammatory cells to in vivo mutagenic responses, were evaluated by co-culturing BAL cells with the rat alveolar epithelial cell line, RLE-6TN for 24 h and the RLE-6TN cells selected for 6TG resistance. Neutrophilic inflammation was detected in all rats exposed to 10 and 100 mg/kg of alpha-quartz and carbon black and 100 mg/kg titanium dioxide; epithelial hyperplasia was observed in rats exposed to 10 and 100 mg/kg of alpha-quartz and 100 mg/kg carbon black. Hprt mutation frequency was increased in alveolar type II cells from rats exposed to 10 and 100 mg/kg of alpha-quartz, 100 mg/kg carbon black and 100 mg/kg titanium dioxide. In vitro exposure of RLE-6TN cells to BAL cells from rats treated with 10 and 100 mg/kg of alpha- quartz or 100 mg/kg carbon black increased hprt mutant frequency. Both macrophage and neutrophil enriched BAL cell populations were mutagenic to RLE-6TN cells, however, the mutagenic activity appeared greatest for neutrophils. Addition of catalase to BAL cell:RLE-6TN co-cultures inhibited the increase in hprt mutation frequency. These studies demonstrate exposure of rats to doses of particles producing significant neutrophilic inflammation is associated with increased mutation in rat alveolar type II cells. The ability of particle- elicited macrophages and neutrophils to exert a mutagenic effect on epithelial cells in vitro supports a role for these inflammatory cells in the in vivo mutagenic effects of particle exposure. The inhibition of BAL cell-induced mutations by catalase implies a role for cell- derived oxidants in this response.      

Early severe weight loss in newborns after discharge from regular nurseries

Aims: To study incidence and risk factors of early neonatal dehydration in a Norwegian population based cohort. Methods: Term neonates admitted to a paediatric department during 2002–2008 with a weight loss ≥ 12% within three weeks of age were identified retrospectively through review of medical records. For each patient a sex‐matched control group of two full‐term infants was selected to assess risk factors for dehydration. Results: A total of 38 of 37 321 infants (1.0‰) were admitted at a median age of 6 (interquartile range 5–12) days, and the admission rate increased during the study period (p for trend = 0.008). Simultaneously, mean nursery stay decreased from 3.5 to 2.7 days (p = 0.022). Mean weight loss was 15.0% of birth weight and 17 of 29 (58.6%) had serum sodium above 145 mmol/L. The only significant difference between patients and controls was that mothers of patients were older (32.3 ± 5.0 vs. 29.4 ± 5.4 years, p = 0.005). Conclusion: Short nursery stay may be a risk factor for dehydration in newborn infants.     

Nummular headache: a series with symptomatic and primary cases

Nummular headache (NH) is a primary headache adopting the form of local pain in a circumscribed area of < 7 cm in diameter in the tuber parietale, albeit it may also be located in other areas of the head. Although it is chronic, it is commonly associated with exacerbations and short periods of remission. Here we report four cases. Two of them could not be considered primary: in one the pain was related to an underlying, pointed and benign lesion disclosed only by magnetic resonance imaging (case 1); the second one had persistent NH days after trans-sphenoidal surgery for a pituitary adenoma, similar to a postcraniotomy headache (case 2). The two final patients suffered from typical forms of primary NH, one associated with migraine without aura, the other with chronic tension-type headache. The response to pain-related treatments and to preventive drugs was poor in the symptomatic as well as in the primary cases. The mechanisms are not clear, and peripheral (case 1) and also central pathways (case 2) could be involved. In the end, secondary forms of NH might coexist with classical primary NH. Particular attention should be paid to tiny skull lesions and to key events preceding the pain.