Enhanced RAGE-mediated NFkappaB stimulation in inflamed hemodialysis patients

Advanced glycation end-products (AGEs), a group of carbohydrate-derived compounds formed by non-enzymatic glycation and oxidation, are markedly elevated in end-stage renal disease (ESRD) and may be related to both inflammation and oxidative stress. The cellular effects of AGE are largely mediated by their interaction with specific surface receptors, such as RAGE. Measurements of biomarkers of inflammation and oxidative stress were conducted in 7 hemodialysis (HD) patients (5 males) with persistent high-grade inflammation (C-reactive protein [CRP] > 10 mg/L) and 11 HD-patients (6 males) with low-grade inflammation (CRP < 10 mg/L) for at least 6 months. Measured biomarkers for inflammation included hs-CRP, interleukin (IL)-6, white blood cells, neutrophils, S-albumin, peroxisome proliferator-activated receptors (PPAR , β, γ) and nuclear factor κB (NFκB) activity. Markers for oxidative stress were advanced oxidation products (AOPP), myeloperoxidase (MPO)-activity, pentosidine and carboxymethyl lysine (CML). In addition, the effect of increasing doses of CML-modified human serum albumin on NFκB activity was tested in mononuclear cells isolated from each patient. As expected, HD-patients with high-grade inflammation had significantly elevated levels of IL-6 (median 9.2 pg/mL versus 2.5 pg/mL; p < 0.01), MPO-activity (134.5 ± 14.6 ΔOD₆₃₀/(min mg protein) versus 80.5 ± 12.9 ΔOD₆₃₀/(min mg protein); p < 0.05), PPAR-γ (0.65 ± 0.01 OD₆₅₅ versus 0.56 ± 0.01 OD₆₅₅; p < 0.01), and AOPP (269 ± 54 μM versus 163 ± 15 μM; p < 0.05) compared with low-grade inflamed patients. Significant associations were demonstrated between hs-CRP and NFκB (ρ = 0.58; p < 0.05), AOPP (ρ = 0.49; p < 0.05) and PPAR-γ (ρ = 0.62; p < 0.05), respectively. In the patient group with high-grade inflammation, stimulation of mononuclear cells with CML-modified human serum albumin caused a rapid dose-dependent rise (p < 0.0001) in NFκB activity that could be completely blocked by an anti-RAGE antibody. Inflammation and oxidative stress biomarkers are interrelated in ESRD. Inflammatory cell signal pathways, such as NFκB, are activated by CML-modification of proteins via RAGE.     

Antibodies to cytokeratin and vimentin in testicular tumour diagnosis

Summary Thirteen primary and metastatic testicular germ cell tumours, including classical and anaplastic seminomas, and non-seminomatous testicular tumours were examined for their intermediate filament protein (IFP) types. The seminomas were shown to react with a monoclonal and a polyclonal antibody to bovine lens vimentin, while non-seminomatous germ cell tumours were strongly positive for a polyclonal and a monoclonal antibody to cytokeratin.In one case of seminoma with elevated serum levels ofHCG andFP, cytokeratin positive tumour cells were found. In the case of teratocarcinoma, several components of the tumour could be distinguished using a combination of antisera in double-label immunofluorescence microscopy. The glandular component of this tumour was positive with the polyclonal antikeratin, but also with the monoclonal cytokeratin antibody specific for glandular epithelia (RGE 53). However, the squamous component was negative with this latter antibody. Strikingly, the spindle cell component showed focal positivity for vimentin, with coexpression of cytokeratin and vimentin in some cells.Our data show that antibodies to cytokeratin and vimentin can be helpful in the diagnosis of testicular germ cell tumours, especially in the differentiation between seminomas and non-seminomatous tumours.This study was supported by a grant from the Dutch Cancer Foundation, The Queen Wilhelmina Fund (KWF), project NUKC 1981-12     

Do airway clearance mechanisms influence the local and systemic effects of inhaled corticosteroids?

The role of airway clearance in inhaled drug therapy is complex. Disease-induced bronchoconstriction results in a central drug-deposition pattern where mucociliary clearance is most efficient. When drug-induced bronchodilation is achieved, deposition and uptake becomes more peripheral, and because there is less mucociliary clearance in the periphery, this will lead to an unintentional increase in lung exposure and enhance the risk of systemic side effects. In addition, mucociliary clearance is pathologically reduced in both asthma and chronic obstructive pulmonary disease. Among inhaled corticosteroids, rate of dissolution and lung uptake differs considerably. For the slowly dissolving, lipophilic steroids, the contribution of mucociliary clearance to these findings appears significant, and variability in lung and systemic exposure resulting from variable mucociliary function appears to be amplified. In addition, dose optimisation of non-stable asthma becomes more complex. The present review highlights the impact of mucociliary clearance on inhaled corticosteroid disposition and identifies critical areas where more research is needed.     

Is the test result correct? A questionnaire study of blood collection practices in primary health care

Rationale, aims and objectives Venous blood tests are important for clinical decision making. Most errors in blood testing are due to human errors before the blood samples reach the laboratory. The present study was designed to investigate venous blood sampling (VBS) practices in primary health care centres (PHCs) compared with clinical laboratory staff. Method A cross‐sectional survey of 70 PHCs and two clinical laboratories is conducted. All staff responsible for VBS (317 respondents, response rate 94%) completed a questionnaire on VBS practices. Results Instructions for VBS were not followed in the surveyed PHCs. For example, only 54% reported that they always identified the patient by using name/Swedish identification number and only 5% reported that they always used photo‐ID, the two preferred means for patient identification. Only 12% reported that they always released venous stasis as soon as possible. Fewer PHC staff than clinical laboratory staff reported correct VBS practices. For example, 54% of the PHC staff reported that they always identified the patient by name and Swedish identification number, as compared with 95% of the clinical laboratory staff (P < 0.001). Documented VBS routines and re‐education in VBS were not clearly associated with reported correct VBS practices. Conclusions In the surveyed PHCs, there are clinically important risks for misidentification of patients and erroneous test results, with consequences for the diagnosis and treatment of patients. Quality interventions, aimed at improving VBS practices, are needed to ensure patient safety.     

IL-8 and tumor necrosis factor alpha in heart valves from patients with infective endocarditis

The embedding of bacteria in the vegetation of infective endocarditis impedes the penetration of phagocytic cells. IL-8 has a stimulating effect on the immune system, particularly with respect to chemotaxis and activation of granulocytes. Tumor necrosis factor alpha (TNF-alpha) is 1 of the major proinflammatory cytokines. IL-8 and TNF-alpha were visualized by means of immunohistochemistry in paraffin-embedded heart valve biopsies from 6 patients with infective endocarditis who required cardiac surgery during the active phase of the infection. In 5/6 patients there were signs of inflammation, and in these patients IL-8- and TNF-alpha-containing cells were visualized in the heart valve stromas or vegetations. The largest numbers of IL-8-containing cells, and the greatest amount of inflammation, were seen in patients with short preoperative treatment courses. No such relationships were seen with respect to TNF-alpha-containing cells. These observations may suggest that the occurrence of IL-8-containing cells in infected heart valves could be used as a marker of disease activity.     

Comparison of effects of a thrombin-based femoral artery closure device with those of a mechanical compression device on serum C-reactive protein and amyloid A after percutaneous coronary intervention

The present study evaluates whether the closing procedure of the femoral artery after percutaneous coronary intervention influences the degree of inflammation related to the procedure as measured by C-reactive protein (CRP) and serum amyloid A (SAA). A thrombin-based device (Duett sealing device) was compared with a mechanical compression device (FemoStop).     

Peripheral and central ventilatory responses in central sleep apnea with and without congestive heart failure

Given that the apnea-ventilation cycle length during central sleep apnea (CSA) with congestive heart failure (CHF) is approximately 70 s, we hypothesized that rapidly responsive peripheral CO(2) ventilatory responses would be raised in CHF-CSA and would correlate with the severity of CSA. Sleep studies and single breath and rebreathe hypercapnic ventilatory responses (HCVR) were measured as markers of peripheral and central CO(2) ventilatory responses, respectively, in 51 subjects: 12 CHF with no apnea (CHF-N), 8 CHF with obstructive sleep apnea (CHF-OSA), 12 CHF-CSA, 11 CSA without CHF ("idiopathic" CSA; ICSA), and 8 normal subjects. Single breath HCVR was equally elevated in CHF-CSA and ICSA groups compared with CHF-N, CHF-OSA, and normal groups (0.58 +/- 0.09 [mean +/- SE] and 0. 58 +/- 0.07 versus 0.23 +/- 0.06, 0.25 +/- 0.04, and 0.27 +/- 0.02 L/min/PET(CO(2)) mm Hg, respectively, p < 0.001). Similarly, rebreathe HCVR was elevated in both CHF-CSA and ICSA groups compared with CHF-N, CHF-OSA, and normal groups (5.80 +/- 1.12 and 3.53 +/- 0. 29 versus 2.00 +/- 0.25, 1.44 +/- 0.16, and 2.14 +/- 0.22 L/min/PET(CO(2)) mm Hg, respectively, p < 0.001). Furthermore, in the entire CHF group, single breath HCVR correlated with central apnea-hypopnea index (AHI) (r = 0.63, p < 0.001) and percentage central/total apneas (r = 0.52, p = 0.022). Rebreathe HCVR correlated with awake Pa(CO(2)) (r = -0.61, p < 0.001), but not with central AHI or percentage central/total apneas independent of its relationship with single breath HCVR. In conclusion, in subjects with CHF, raised central CO(2) ventilatory response predisposes to CSA promoting background hypocapnia and exposing the apnea threshold to fluctuations in ventilation, whereas raised and faster-acting peripheral CO(2) ventilatory response determines the periodicity and severity of CSA.     

Syntaxin 1 interacts with the LD subtype of voltage-gated Ca2+ channels in pancreatic β cells

Interaction of syntaxin 1 with the alpha(1D) subunit of the voltage-gated L type Ca(2+) channel was investigated in the pancreatic beta cell. Coexpression of the enhanced green fluorescent protein-linked alpha(1D) subunit with the enhanced blue fluorescent protein-linked syntaxin 1 and Western blot analysis together with subcellular fractionation demonstrated that the alpha(1D) subunit and syntaxin 1 were colocalized in the plasma membrane. Furthermore, the alpha(1D) subunit was coimmunoprecipitated efficiently by a polyclonal antibody against syntaxin 1. Syntaxin 1 also played a central role in the modulation of L type Ca(2+) channel activity because there was a faster Ca(2+) current run-down in cells incubated with antisyntaxin 1 compared with controls. In parallel, antisyntaxin 1 markedly reduced insulin release in both intact and permeabilized cells, subsequent to depolarization with K(+) or exposure to high Ca(2+). Exchanging Ca(2+) for Ba(2+) abolished the effect of antisyntaxin 1 on both Ca(2+) channel activity and insulin exocytosis. Moreover, antisyntaxin 1 had no significant effects on Ca(2+)-independent insulin release trigged by hypertonic stimulation. This suggests that there is a structure-function relationship between the alpha(1D) subunit of the L type Ca(2+) channel and the exocytotic machinery in the pancreatic beta cell.     

Function and dysfunction of the colon and anorectum in adults: Working team report of the Swedish Motility Group (SMoG)

Symptoms of fecal incontinence and constipation are common in the general population. These can, however, be unreliably reported and are poorly discriminatory for underlying pathophysiology. Furthermore, both symptoms may coexist. In the elderly, fecal impaction always must be excluded. For patients with constipation, colon transit studies, anorectal manometry and defecography may help to identify patients with slow-transit constipation and/or pelvic floor dysfunction. The best documented medical treatments for constipation are the macrogols, lactulose and isphagula. Evolving drugs include lubiprostone, which enhances colonic secretion by activating chloride channels. Surgery is restricted for a highly selected group of patients with severe slow-transit constipation and for those with large rectoceles that demonstrably cause rectal evacuatory impairment. For patients with fecal incontinence that does not resolve on antidiarrheal treatment, functional and structural evaluation with anorectal manometry and endoanal ultrasound or magnetic resonance (MR) of the anal canal may help to guide management. Sacral nerve stimulation is a rapidly evolving alternative when other treatments such as biofeedback and direct sphincter repair have failed. Advances in understanding the pathophysiology as a guide to treatment of patients with constipation and fecal incontinence is a continuing important goal for translational research. The content of this article is a summary of presentations given by the authors at the Fourth Meeting of the Swedish Motility Group, held in Gothenburg in April 2007.