Dissection of the hyperadhesive phenotype of airway eosinophils in asthma

Asthma is characterized by appearance of eosinophils in the airway. Eosinophils purified from the airway 48 h after segmental antigen challenge are described as exhibiting greater adhesion to albumin-coated surfaces via an unidentified beta2 integrin and increased expression of alphaMbeta2 (CD11b/18) compared with purified blood eosinophils. We have investigated the determinants of this hyperadhesive phenotype. Airway eosinophils exhibited increased reactivity with the CBRM1/5 anti-alphaM activation-sensitive antibody as well as enhanced adhesion to VCAM-1 (CD106) and diverse ligands, including albumin, ICAM-1 (CD54), fibrinogen, and vitronectin. Purified blood eosinophils did not adhere to the latter diverse ligands. Enhanced adhesion of airway eosinophils was blocked by anti-alphaMbeta2. Podosomes, structures implicated in cell movement and proteolysis of matrix proteins, were larger and more common on airway eosinophils adherent to VCAM-1 when compared with blood eosinophils. Incubation of blood eosinophils with IL-5 replicated the phenotype of airway eosinophils. That is, IL-5 enhanced recognition of alphaM by CBRM1/5; stimulated alphaMbeta2-mediated adhesion to VCAM-1, albumin, ICAM-1, fibrinogen, and vitronectin; and increased podosome formation on VCAM-1. Thus, the hyperadhesion of airway eosinophils after antigen challenge is mediated by upregulated and activated alphaMbeta2.     

Elevated serum 8-oxo-dG in hemodialysis patients: a marker of systemic inflammation?

Does inflammation, as assessed by high sensitivity C-reactive protein (hs-CRP), in patients with end-stage renal disease (ESRD) tightly associate with increased serum levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8- oxo-dG)? Increased oxidative stress and inflammation have both been highlighted among several nontraditional risk factors for cardiovascular disease, which is the main cause of mortality in ESRD patients. In contrast to oxidative stress effects on proteins and lipids, DNA base damage has not been well demonstrated in ESRD. Two groups of hemodialysis patients were studied, one group with persistent inflammation (n = 13, with constant elevation of CRP > 10 mg/L for 6 months) and one group of noninflamed patients (n = 19, with constant CRP < 10 mg/L for 6 months). Serum 8-oxo-dG was significantly elevated in persistent inflammation in comparison to noninflamed patients. At an individual level, a significant correlation was found between serum 8-oxo-dG and hsCRP. Extracellular 8-oxo-dG leads to intracellular oxidative damage on the nucleotide pool, thus providing a sensitive marker for inflammatory response. Serum levels of 8-oxo-dG, in combination with other inflammatory markers, serve as useful diagnostic tools for identification of patients in risk for inflammatory complications.     

Prediction of inspiratory flow shapes during sleep with a mathematic model of upper airway forces

STUDY OBJECTIVES: To predict the airflow dynamics during sleep using a mathematic model that incorporates a number of static and dynamic upper airway forces, and to compare the numerical results to clinical flow data recorded from patients with sleep-disordered breathing on and off various treatment options. DESIGN: Upper airway performance was modeled in virtual subjects characterized by parameter settings that describe common combinations of risk factors predisposing to upper airway collapse during sleep. The treatments effect were induced by relevant changes of the initial parameter values. SETTING: Computer simulations at our website (http://www.utu.fi/ml/sovmat/bio/). PARTICIPANTS: Risk factors considered in the simulation settings were sex, obesity, pharyngeal collapsibility, and decreased phasic activity of pharyngeal muscles. INTERVENTIONS: The effects of weight loss, pharyngeal surgery, nasal continuous positive airway pressure, and respiratory stimulation on the inspiratory flow characteristics were tested with the model. MEASUREMENTS AND RESULTS: Numerical predictions were investigated by means of 3 measurable inspiratory airflow characteristics: initial slope, total volume, and flow shape. The model was able to reproduce the inspiratory flow shape characteristics that have previously been described in the literature. Simulation results also supported the observations that a multitude of factors underlie the pharyngeal collapse and, therefore, certain medical therapies that are effective in some conditions may prove ineffective in others. CONCLUSIONS: A mathematic model integrating the current knowledge of upper airway physiology is able to predict individual treatment responses. The model provides a framework for designing novel and potentially feasible treatment alternatives for sleep-disordered breathing.     

A Modified Post-Transplant Cyclophosphamide Regimen,for Unmanipulated Haploidentical Marrow Transplantation,in Acute Myeloid Leukemia: A Multicenter Study

We report a modified post-transplant cyclophosphamide (PT-CY) regimen, for unmanipulated haploidentical marrow transplants, in 150 patients with acute myeloid leukemia (AML). All patients received a myeloablative regimen, cyclosporine A (CsA) on day 0, mycophenolate on day +1, and PT-CY 50?mg/kg on days +3 and +5. The median age was 51 (range, 17–74) years, 51 (34%) patients had active disease at transplant, and the median follow-up of surviving patients 903 (range, 150-1955) days. The cumulative incidence (CI) of engraftment, acute graft-versus-host disease (GVHD) grade II to IV, and moderate/severe chronic GVHD was 92%, 17%, and 15%, respectively. The 4-year CI of transplant-related mortality (TRM) and relapse was 20% and 24%, respectively. Four-year survival for remission patients was 72% (74% versus 67% for <60 or ≥60 years of age) and 26% for advanced patients (17% versus 41% for <60 or ≥60 years of age). In a multivariate analysis, active disease at transplant was the only negative predictor of survival, TRM and relapse. The original PT-CY regimen can be modified with CsA on day 0, still providing protection against GVHD, low toxicity, and encouraging low relapse incidence in AML patients, also over 60 years of age.     

Pronase independent flow cytometry crossmatching of rituximab treated patients

ABO-incompatible (ABOi) kidney transplantation has become an established strategy to increase the number of available living donors. At our center, the conditioning protocol for ABOi patients is based on anti-A/B antibody removal and depletion of B cells with the anti-CD20 mAb rituximab (Mabthera®). It is known that even low amounts of remaining rituximab in serum of patients results in false positive B cell cross match results, masking detection of potentially harmful donor human leukocyte antigen (HLA) specific antibodies. Treatment of donor cells with high concentrations (>1?mg/mL) of pronase is currently standard procedure for elimination of rituximab (RIT) interference. It is, however, troublesome that recent reports indicate that pronase treatment per se can induce incorrect flow cytometry cross match (FCXM) results. The aim of this study was to evaluate an alternative pronase-free FCXM for crossmatching of patients treated with rituximab.FCXM with an anti-RIT monoclonal antibody (mAb) pre-blocking step were evaluated on normal human sera (NHS) and patient sera supplemented with RIT. NHS supplemented with RIT or patient sera, without donor specific antibodies (DSA), resulted in high B cell median channel shift (>200 IgG) above background. This shift was eliminated by a serum pre-blocking step with 2-fold excess of anti-RIT (clone MB2A4). Blocking with anti-RIT did not influence the T cells crossmatch results. We present data supporting proof-of-concept that blocking with anti-RIT antibody prior to XM can enable reliable detection of anti-HLA class I and II donor specific antibodies without use of pronase treated donor cells.     

A randomized controlled trial of guided Internet-delivered cognitive behavioral therapy for erectile dysfunction

IntroductionMen with erectile dysfunction are often worried about their condition, have interpersonal difficulties, and have a reduced quality of life. Internet‐delivered cognitive behavior therapy (ICBT) has been shown effective for a number of health problems but evidence is limited concerning the treatment of erectile dysfunction.AimThe study investigated the effects of ICBT for erectile dysfunction.MethodsSeventy‐eight men were included in the study and randomized to either ICBT or to a control group, which was an online discussion group. Treatment consisted of a 7‐week Web‐based program with e‐mail‐based therapist support. Each therapist spent an average of 55 minutes per participant.Main Outcome MeasureThe International Index of Erectile Functioning five‐item version was administered via the telephone at pretreatment, post‐treatment, and 6 months after receiving ICBT.ResultsAt post‐treatment, the treatment group had significantly greater improvements with regard to erectile performance compared with the control group. Between‐group differences at post‐treatment were small (d = 0.1), but increased at the 6‐month follow‐up (d = 0.88).ConclusionsThis study provides support for the use of ICBT as a possible treatment format for erectile dysfunction. Andersson E, Walén C, Hallberg J, Paxling B, Dahlin M, Almlöv J, Källström R, Wijma K, Carlbring P, and Andersson G. A randomized controlled trial of guided Internet‐delivered cognitive behavioral therapy for erectile dysfunction. J Sex Med 2011;8:2800–2809.     

Androgen levels, insulin sensitivity, and early insulin response in women with polycystic ovary syndrome: a long-term follow-up study

Thirty-four women with polycystic ovary syndrome who previously had participated in studies with intravenous glucose tolerance test and hyperinsulinemic, euglycemic clamp between 1987 and 1995 underwent anthropometric, endocrine (T and sex-hormone binding globulin serum concentration), and metabolic (intravenous glucose tolerance test, hyperinsulinemic, euglycemic clamp, and androgens) measurements. Free androgen levels and β-cell function decreased over time in women with polycystic ovary syndrome, but insulin sensitivity remained unaltered.     

GABA is localized in dopaminergic synaptic vesicles in the rodent striatum

Recently, electrophysiological evidence was given for inhibitory postsynaptic responses at dopaminergic striatal synapses. These responses were independent of the vesicular GABA transporter, VGAT, but dependent on the vesicular dopamine transporter VMAT2. The identity and the exact source of the released molecule, as well as the presence of the putative inhibitory transmitter in VMAT2 containing synaptic vesicles remain to be shown. To clarify this, in particular to determine whether GABA is responsible for the inhibitory response at dopaminergic synapses, we used the electron microscopic immunogold method to label in vivo perfusion fixed striatal tissue with antibodies recognising GABA, VGAT, VMAT2 and tyrosine hydroxylase. We show that about 13 % of tyrosine hydroxylase positive and 11 % of VMAT2 axonal terminals in the caudo-putamen contain significant labelling for GABA. Immunogold signals for tyrosine hydroxylase and VGAT was totally segregated into different pools of nerve terminals. Quantitative analyses of the distance between gold particles signalling GABA and synaptic vesicles showed that GABA was as closely associated with synaptic vesicles in tyrosine hydroxylase positive as in tyrosine hydroxylase negative nerve terminals. Likewise, in dopaminergic terminals GABA and VMAT2 immunogold particles showed a close spatial localization, strongly suggesting the presence of GABA in VMAT2 positive synaptic vesicles. Our results suggest that GABA is exocytosed together with dopamine from dopaminergic nerve terminals in the caudo-putamen through VGAT negative and VMAT2 positive synaptic vesicles.     

Sleep Homeostasis During Repeated Sleep Restriction and Recovery: Support from EEG Dynamics

Study Objectives:

Sleep reduction normally causes a homeostatic response during subsequent recovery sleep, but this does not seem to be true for repeated partial sleep loss. The aim of the present study was to test the response to repeated partial sleep loss through detailed focus on spectral data and parts of sleep.

Design:

The experiment involved 4 h of sleep across 5 days in the laboratory (partial sleep deprivation [PSD]), followed by 3 days of recovery sleep. PSD was achieved through a delayed bedtime. Nine individuals participated. To avoid “laboratory monotony,” subjects were permitted to leave the lab for a few hours each day.

Measurements and results:

All sleep stages and the latencies to sleep and slow wave sleep (SWS) showed a significant reduction during PSD. However, SWS and TST (total sleep time) during the first half of sleep increased gradually across days with PSD. During the first recovery sleep, SWS was significantly increased, while stage 1 and latency to stage 3 were reduced. All were back to baseline on the second night of recovery sleep. Summed spectral power during the first 3.8 h of sleep showed a gradual and robust increase (50% above baseline) in the range 1.25–7.25 Hz across days with PSD up to first recovery sleep and then returned to baseline.

Conclusions:

SWS and summed power density in a broad low-frequency band respond to repeated partial sleep deprivation in a dose-response fashion during the first 4 h sleep, apparently reflecting a robust and stable homeostatic response to sleep loss.

Citation:

Åkerstedt T; Kecklund G; Ingre M; Lekander M; Axelsson J. Sleep homeostasis during repeated sleep restriction and recovery: support from EEG dynamics. SLEEP 2009;32(2):217–222.