Markers of microbial translocation predict hypertension in HIV-infected individuals

OBJECTIVES

The aim of the study was to test the hypothesis that microbial translocation, quantified by levels of lipopolysaccharide (LPS) and subsequent monocyte activation [soluble (sCD14)], is associated with hypertension in HIV-infected individuals.

METHODS

In this exploratory substudy, 42 patients were recruited from a larger, longitudinal HIV-infected cohort study on blood pressure. LPS and sCD14 levels were measured retrospectively at the time of nadir CD4 cell count, selecting untreated HIV-infected patients with both advanced immunodeficiency and preserved immunocompetence at the time of nadir. Patients with later sustained hypertension (n = 16) or normotension (n = 26) throughout the study were identified. LPS was analysed using the Limulus Amebocyte Lysate colorimetric assay (Lonza, Walkersville, MD) and sCD14 using an enzyme-linked immunosorbent assay (ELISA). Nonparametric statistical tests were applied.

RESULTS

In the HIV-infected patients [median (interquartile range) age 42 (32-46) years; 79% male and 81% Caucasian], LPS and sCD14 levels were both negatively correlated with nadir CD4 cell count. Plasma levels of LPS (P < 0.001) and sCD14 (P = 0.024) were elevated in patients with later hypertension compared with patients with normotension. There was a stepwise increase in the number of patients with hypertension across tertiles of LPS (P = 0.001) and sCD14 (P = 0.007). Both LPS and sCD14 were independent predictors of elevated blood pressure after adjustment for age and gender. For each 10-unit increase in LPS (range 66-272 pg/ml), the increment in mean blood pressure in the first period of blood pressure recording was 0.86 (95% confidence interval 0.31-1.41) mmHg (P = 0.003).

CONCLUSIONS

As LPS and sCD14 were both independently associated with elevated blood pressure, microbial translocation may be linked to the development of hypertension.

Circulating levels of HMGB1 are correlated strongly with MD2 in HIV-infection: possible implication for TLR4-signalling and chronic immune activation

Progressive HIV infection is characterized by profound enterocyte damage, microbial translocation and chronic immune activation. We aimed to test whether High Mobility Group Box protein 1(HMGB1), a marker of cell death, alone, or in combination with LPS, might contribute to HIV-associated immune activation and progression. Altogether, 29 untreated HIV-infected individuals, 25 inflammatory bowel disease (IBD) patients and 30 controls were included. HIV-infected patients had lower plasma LPS levels than IBD patients, but higher levels of soluble CD14 and Myeloid Differentiation (MD) 2, which interacts with TLR4 to initiate LPS-signalling. Furthermore, plasma levels of HMGB1 and MD2 were correlated directly within the HIV-infected cohort (r = 0.89, P < 0.001) and the IBD-cohort (r = 0.85, P < 0.001), implying HMGB1 signalling through the MD2/TLR4-pathway. HMGB1 and LPS, although not inter-correlated, were both moderately (r = 0.4) correlated with CD38 density on CD8+ T cells in HIV progressors. The highest levels of CD38 density and MD2 were found in progressors with plasma levels of both LPS and HMGB1 above the fiftieth percentile. Our results could imply that, in some patients, immune activation is triggered by microbial translocation, in some by cell death and in some by HMGB1 in complex with bacterial products through activation of the MD2/TLR4-pathway.

High levels of HMGB1 in plasma may be due to ex vivo cell necrosis

BACKGROUND

High mobility group box 1 protein (HMGB1) is considered an important biological marker during inflammation and malignancies. Here, we evaluated sample handling and effects of ex vivo necrosis on HMGB1 levels.

MATERIALS AND METHODS

Plasma samples were obtained from healthy volunteers (n=14) simulating the standard laboratory conditions, overnight incubations and harsh treatment. HMGB1 levels were evaluated by ELISA or western blot. Additionally, levels of hemoglobin, hemolysis index and lactate dehydrogenase were measured.

RESULTS

Plasma levels of HMGB1 were 9-fold increased in samples stored overnight at room temperature, as compared to those processed directly. The rapid centrifugation prevented the increase of HMGB1 in stored samples. Hemoglobin, hemolysis index and lactate dehydrogenase concentrations showed significant correlations with HMGB1 levels.

CONCLUSION

Handling of blood samples is important for the accurate estimation of systemic HMGB1. We propose that all samples with high HMGB1 concentrations should be evaluated for markers of ex vivo necrosis.

Familial predisposition to vasovagal syncope

OBJECTIVE

A handful of studies suggest a familial predisposition to vasovagal syncope (WS) but the scope of information available to date is poor. The aim of our study was to evaluate the prevalence of vasovagal syncope and its familial occurrence in the young.

METHODS AND RESULTS

The studied group consisted of 281 women and 111 men, aged 18-32 years. Forty-seven percent of the population had one brother or sister, and the mean number of individuals per family was 4.4 +/- 1.0. The questionnaire consisted of 30 questions regarding syncopal history. Syncope was reported in 32.1% of the patients studied (36.7% in women vs. 20.7% in men; P < 0.05), 29.1% of mothers, 16.8% of fathers, 30.9% of sisters and 14.2% of brothers. Logistic regression analysis revealed that positive history regarding the syncope in the whole group of students was related to the female gender (OR 2.17; CI: 1.28-3.7), the history of a syncope in mother (OR 1.74; CI: 1.09-2.78) and the history of a syncope in father (OR 2.22; CI: 1.28-3.86; P < 0.001).

CONCLUSIONS

A positive history of syncope in male relatives increases the risk of syncope in men and women, whereas a positive history of syncope in female relatives increases the risk of syncope in women only. Female gender independently of the family history increases the risk of syncope. The genetics of the vasovagal syncope could be polygenic but the mechanisms of a transmission remain unclear to date.

Virolysis of feline calicivirus and human GII.4 norovirus following chlorine exposure under standardized light soil disinfection conditions

The relationship between the infectivity of the feline calicivirus (FCV) vaccine strain F-9 and capsid destruction (virolysis) in response to available chlorine was investigated under standardized light soil disinfection conditions. Virolysis was measured using RNase pretreatment (in order to destroy exposed RNA following chlorine treatment) and quantitative reverse transcription PCR. A comparison between the results of plaque assays and virolysis following exposure of FCV F-9 grown in tissue culture to different concentrations of available chlorine showed a similar log-linear relationship, with >4-log reductions occurring at 48 and 66 ppm, respectively. Three non-epidemiologically linked human GII.4 noroviruses (NoVs) present in dilute clinical samples showed behavior similar to each other and were 10 times more resistant to virolysis than cultured FCV F-9. FCV F-9 when present in dilute human GII.4 samples acquired increased resistance to virolysis approaching that of human NoVs. This study represents a direct comparison between the virolysis of a surrogate virus (FCV F-9) and that of human GII.4 NoVs within the same matrix in response to available chlorine. The results support the view that matrix effects have a significant effect on virus survival.

Cyanines as efficient photosensitizers in photodynamic reaction: photophysical properties and in vitro photodynamic activity

The purpose of the present study was to explore the potential application of cyanines in photodynamic treatment. The photophysical features of four cyanines (KF570, HM118, FBF-749, and ER-139) were investigated by elemental and spectral analyses. Two malignant cell lines (MCF-7/WT and MCF-7/DOX) were used to test the potential for use in the photodynamic therapy. The cytotoxic effects of these dyes were determined by the MTT assay after 4 and 24 h of incubation with the cyanine. KF570 and HM118 were irradiated with red light (630-nm filter) and FBF-749 and ER-139 with green light (435-nm filter). The results showed that the cyanine HM118 demonstrated a major phototoxic effect. It was also noted that the efficiency of photodynamic therapy was higher in the doxorubicin-resistant cell line (MCF-7/DOX).

High mobility group box protein-1 in HIV-1 infection

Chronic immune activation driven by microbial translocation from a damaged gut plays a fundamental role in HIV-1 progression. However, the exact link between a leaky gut and immune activation remains to be established. A growing body of evidence suggests that high mobility group box protein-1 (HMGB1) may be involved in this process. HMGB1 is a DNA binding protein present in every nucleated cell, which might be actively secreted to the extracellular milieu by activated cells or passively released from damaged or dying cells. The biological effect depends on its ability to form complexes: HMGB1 alone signals through the receptor of advanced glycosylated end products (RAGE) and promotes regeneration and repair, whereas HMGB1 in complex with bacterial products signal via toll like receptors (TLRs) and promotes immune activation. Plasma levels of HMGB1 are elevated in HIV-1 infected patients and reduced by antiretroviral therapy. The protein might be released from necrotic and apoptotic HIV-1 infected cells. HMGB1 may stimulate or inhibit HIV-1 replication in vitro, depending on the stage of infection, type of cell and purity of the protein: The protein has been suggested to reduce viral replication by interfering with viral entry in acute infection and to increase viral replication in latently infected cells. Finally, HMGB1 in combination with microbial products/TLR ligands seems to be associated with increased viral replication in vitro and in vivo.

Intracranial Radiosurgery in the Netherlands. A Planning Comparison of Available Systems with Regard to Physical Aspects and Workload

Different planning and treatment systems for intracranial stereotactic radiosurgery available in the Netherlands are compared. The systems for intracranial radiosurgery include: Gamma Knife, Cyberknife, Novalis, and Tomotherapy. Electronic data of 5 patients was transferred to all participating centres and treatment plans were generated according to 2 different prescription protocols. For this study, plans were also generated for a conventional linac. Even systems with a high resolution (Gammaknife and Novalis) have conformity indices in violation with RTOG guidelines (CI > 2.5) when target volumes of <0.5 cc are treated. For medium sized targets (0.5–1 cc) all systems performed reasonably well, but for the different systems a large range of conformity indices was seen (1.1 to 3.7). The differences are partly system dependent but depend also on specific planning choices made. For larger target volumes (>1 cc), all systems perform well. The workload of the different techniques was comparable although the treatment times were usually longer for Gamma Knife radiosurgery. We conclude that small targets should be treated by dedicated systems, larger volumes (>0.5–1 cc) can also be treated using conventional treatment systems equipped with a MLC.

The role of polyphenols in cardiovascular disease

Epidemiological studies suggest that diets rich in polyphenols may be associated with reduced incidence of cardiovascular disorders (mainly coronary heart disease and myocardial infarction). However, the mechanisms explaining this correlation have not been fully elucidated. Current evidence suggests that polyphenols, acting at the molecular level, improve endothelial function and inhibit platelet aggregation. In view of their antithrombotic, anti-inflammatory, and anti-aggregative properties, these compounds may play a roles in the prevention and treatment of cardiovascular disease.

Implications of the release of high-mobility group box 1 protein from dying cells during human immunodeficiency virus type 1 infection in vitro

Plasma levels of high-mobility group box 1 protein (HMGB1) are elevated during the course of human immunodeficiency virus type 1 (HIV-1) infection and the molecule has an impact on virus replication. This study investigated the mode of cell death and release of HMGB1 during HIV-1 infection in vitro. MT4 cells and primary CD4(+) T cells were infected with HIV-1 isolates, and HMGB1 release was monitored in relation to cytopathic effects (CPE) and apoptosis. HMGB1 release from cells was analysed by Western blotting. For MT4 cells, an enzyme-linked immunosorbent spot (ELISPOT) assay was adapted to measure the release during necrosis. Lactate dehydrogenase (LDH) activity was quantified using a commercial assay. Flow cytometry was used to determine the level of infection and apoptosis. MT4 cells were > or =90 % infected at 48 h post-infection (p.i.). CPE was first observed at 60 h and correlated with release of HMGB1, LDH activity and caspase-3 (C3) activation. HMGB1 spots were clearly detected by ELISPOT assay at 72 h p.i. Annexin V and C3 staining showed that apoptosis was substantially involved in HIV-1-related cell death. Addition of Z-VAD (a caspase inhibitor) in a single dose at 24 or 40 h p.i. decreased both the number of caspase-positive cells and the release of HMGB1. Infection of primary CD4(+) T cells showed a 22 % (median) infection rate at 96 h. Related CPE corresponded to LDH and HMGB1 release. Both necrosis and apoptosis contributed to HMGB1 liberation during HIV-1-induced cell death and the protein could induce tumour necrosis factor-alpha release from peripheral mononuclear blood cells. These data imply that passive HMGB1 release contributes to the excessive immune activation characteristic of HIV-1 pathogenesis.

Characteristics of model polyelectrolyte multilayer films containing laponite clay nanoparticles

Polyelectrolyte films structure formed by the "layer-by-layer" (LbL) technique can be enriched by addition of charged nanoparticles like carbon nanotubes and silver or hydroxyapatite nanoparticles, which can improve properties of the polyelectrolyte films or modify their functionality. In our paper we examined the formation and properties of model polyelectrolyte multilayers containing a synthetic layered silicate, Laponite. The Laponite nanoparticles were incorporated into multilayer films, which were formed from weak, branched polycation PEI and strong polyanion PSS. Since charge of PEI is pH-dependent, we build up multilayer films in two deposition conditions: pH = 6 when PEI was strongly charged and pH = 10.5 when charge density of PEI was low. Thicknesses of the films constructed with various numbers of Laponite layers were measured by single wavelength ellipsometry. We also determined the differences in permeability for selected electroactive molecules using cyclic voltamperometry. Properties of the films containing clay nanoparticles were compared with model polyelectrolyte multilayer films PEI/PSS formed at the same conditions. We found that Laponite nanoparticles strongly influenced PEI/PSS multilayer film properties. Replacement of PSS by Laponite eliminated the oscillations of the film thickness in the case when PEI was weakly charged. PSS layer adsorbed on top of PEI/Laponite bilayers increased the thickness of multilayer films and improved their barrier properties so synergistic effects between these properties for polyelectrolytes and Laponite nanoparticles could be observed.

Kinetics of plasma cytokines and chemokines during primary HIV-1 infection and after analytical treatment interruption

BACKGROUND

There are strong theoretical arguments for initiating antiretroviral therapy (ART) during primary HIV-1 infection (PHI) to preserve HIV-1-specific T-cell responses and to decrease immune activation.

METHODS

We assessed the degree of immune activation during PHI and after analytical treatment interruption (ATI) in plasma samples from 22 subjects by measuring 13 cytokines/chemokines with the Luminex system. Subjects initiated quadruple ART at PHI (the QUEST cohort) and were classified as responders or nonresponders according to their HIV-1 viral load (VL) 6 months post-ATI.

RESULTS

During PHI, nonresponders had higher levels of HIV-1 RNA, interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-10 and eotaxin than responders (P</=0.05). A positive correlation was found between VL and IFN-alpha, TNF-alpha, IL-1beta, macrophage inflammatory protein (MIP)-1alpha and MIP-1beta, respectively. Post ATI, responders had higher levels of IFN-gamma, MIP-1beta and monocyte chemotactic protein (MCP)-1 than nonresponders, while nonresponders had higher levels of HIV-1 RNA, IL-15 and eotaxin. Cytokine/chemokine levels were higher during PHI than post-ATI.

CONCLUSIONS

High levels of immune activation during PHI are associated with a worse virological outcome post-ATI. In contrast, VL post-ATI is negatively correlated with IFN-gamma and chemokines. Therefore, the degree of immune activation during PHI is associated with both the VL at PHI and the viral set-point post-ART.

[Early result of femur neck fracture treated with modular hemiarthroplasty fenix]

The aim of the study is clinical assessment of modular arthroplasty Fenix and early assessment of 77 patient with femoral neck fracture treated with Fenix hemiarthroplasty. The mean age of the group was 77 years. There were 51 woman and 16 men in the group. Size of the used steam and head, the way of steam implantation, time of the operation and early complication was assessed. Operated patients were evaluated with Harris Hip Score, Larson I and Larson II score. The most common used steams were number 3 and 4, and the most common used head was number 44 with -4 mm offset. Mean operation time was 68.9 minute. The following early complication occurs: superficial wound infection treated with antibiotics--8 cases, pneumonia--8 cases, urinary tract infection--6 cases, intra operative femur shaft fracture during steam implantation, treated with plate osetosynthesis--1 cases. There were 14 cases of death in the group. 22 patients were evaluated with HHS and Larson. Mean score in HHS was 71 point, in Larson I--76 point, in Larson II--72 point. There was found that operating technique is similar like in the others hemiarthroplasty system and system is easy to use. Most of the stems were cemented. There was found that there are a high percent of death in femur neck fracture patient group during the first year after the operation and this kind of fractures handicap patient locomotion in spite of good hip joint function.