Mechanisms of PDGFRalpha promiscuity and PDGFRbeta specificity in association with PDGFB

Platelet-derived growth factor receptor alpha (PDGFRalpha) interacts with PDGFs A, B, C and AB, while PDGFRbeta binds to PDGFs B and D, thus suggesting that PDGFRalpha is more promiscuous than PDGFRbeta. The structural analysis of PDGFRalpha-PDGFA and PDGFRalpha-PDGFB complexes and a molecular explanation for the promiscuity of PDGFRalpha and the specificity of PDGFRbeta remain unclear. In the present study, we modeled the three extracellular domains of PDGFRalpha using a previous crystallographic structure of PDGFRbeta as a template. Additionally, we analyzed the interacting residues of PDGFRalpha-PDGFA and PDGFRalpha-PDGFB complexes using docking simulations. The validation of the resulting complexes was evaluated by molecular dynamics simulations. Structural analysis revealed that changes of non-aromatic amino acids in PDGFRalpha to aromatic amino acids in PDGFRbeta (I139F, P267F and N204Y) may be involved in the promiscuity of PDGFRalpha. Indeed, substitution of amino acids with few probabilities of rotamer changes in PDGFRbeta (M133A, N163E and N179S) and energy stability due to the formation of hydrogen bond in PDGFRbeta could explain the specificity of PDGFRbeta. These results may be used as an input for a better and more specific drug and peptide design targeting diseases related with the malfunction of PDGFs and PDGFRalpha such as cancer and atherosclerosis.

Sealing Composite With Defective Margins, Good Care or Over Treatment? Results of a 10-year Clinical Trial

Purpose

The objective of this study was to clinically evaluate sealed composite restorations after 10 years and compare their behavior with respect to controls.

Methods and Materials

The cohort consisted of 20 patients aged 18 to 80 years with 80 composite restorations. All participants in the sealing and no-treatment groups presented with clinical features for the marginal adaptation that deviated from the ideal and were rated Bravo (United States Public Health Service criteria). Composites with Alfa values for the marginal adaptation were used as the positive control.

Results

The marginal adaptation behavior was similar between the sealing and control (+) groups, with a high frequency of Bravo values in the 10th year (80% and 51%, respectively). Most of the no-treatment (-) group maintained the Bravo values (91%) for 10 years, although some restorations (9%) progressed to Charlie values. The anatomy parameter differed significantly between the first and 10th years, with deterioration in all three groups (p<0.05). The secondary caries parameter had a similar behavior in the three groups (p>0.05).

Conclusions

Sealing the margins of the composite resin restorations had no significant effect compared with the control groups, under the conditions of this study. Sealing the restorations substantially improved the marginal staining and marginal adaptation parameters, although by the tenth year they were similar to the group without intervention.

Síndrome del canal radial: nueva técnica de liberación endoscópica

El objetivo de este trabajo es presentar una nueva técnica endoscópica para la liberación de la rama motora del nervio radial en el síndrome del canal radial.

El síndrome del canal radial es la neuropatía compresiva de la rama motora del nervio radial que, muy a menudo, requiere la liberación quirúrgica mediante la apertura completa de las estructuras que producen la compresión.

Las vías de abordaje convencionales son amplias, requieren disecciones agresivas y laboriosas. El pequeño tamaño del nervio y su posición profunda entre vientres musculares hace que, fácilmente, pueda ser dañado durante su disección si la visualización no es correcta en todo momento.

Presentamos una nueva técnica que combina el marcaje preoperatorio de la posición del nervio mediante ecografía y liberación mediante técnica endoscópica.

Esta técnica permite un abordaje quirúrgico mucho menor, una mejor visualización del nervio en todo su recorrido y de las estructuras anatómicas durante la disección.

Se presenta una serie de 22 intervenciones en 20 pacientes intervenidos entre 2010 y 2014. En 14 casos los resultados fueron excelentes, 5 buenos y 3 regulares. Las complicaciones fueron en un caso una lesión parcial del nervio durante la cirugía y 4 casos de paresia a la extensión de los dedos que se recuperaron completamente en todos los casos entre las 3 y 6 semanas.

Tibolone protects T98G cells from glucose deprivation

The steroidal drug Tibolone is used for the treatment of climacteric symptoms and osteoporosis in post-menopausal women. Although Tibolone has been shown to exert neuroprotective actions after middle cerebral artery occlusion, its specific actions on glial cells have received very little attention. In the present study we have assessed whether Tibolone exerts protective actions in a human astrocyte cell model, the T98G cells, subjected to glucose deprivation. Our findings indicate that Tibolone decreases the effects of glucose deprivation on cell death, nuclear fragmentation, superoxide ion production, mitochondrial membrane potential, cytoplasmic calcium concentration and morphological parameters. These findings suggest that glial cells may participate in the neuroprotective actions of Tibolone in the brain.

Direct imaging of the magnetization reversal in microwires using all-MOKE microscopy

We report a method of imaging of the magnetization reversal process using analysis of real-time images of magnetic domain structures in cylindrically shaped microwires. This method uses wide-field polarizing optical microscopy and is based on the magneto-optical Kerr effect (MOKE). The aperture diaphragm in MOKE microscope was used to control the incident angles of the light rays that reached the non-planar surface of the microwire and also determined the MOKE geometries. The movement of the non-central position of the hole in this diaphragm leads to a change in the orientation of the plane of incidence of the light along the perpendicular or the parallel direction to the axial direction of the wire. The visualization of the surface magnetic domain structures is obtained using polar and longitudinal MOKE geometries. The hysteresis loops were obtained by plotting the averaged image contrast as a function of the external magnetic field. The separation of the all-magnetization components is performed using different MOKE geometries in a microscope. We demonstrate the use of vector magnetometry to analyze the orientation of the magnetization in a cylindrically shaped microwire under the influence of an external magnetic field.

HIV status and viral loads among men testing positive for rectal gonorrhoea and chlamydia, Maricopa County, Arizona, USA, 2011-2013

OBJECTIVES

Men diagnosed with rectal gonorrhoea (GC) and chlamydia (CT) have engaged in unprotected receptive anal intercourse. We reviewed the HIV positivity and HIV viral loads (VLs) of men who had rectal GC and CT testing to evaluate potential HIV acquisition and transmission risk.

METHODS

Rectal GC and CT testing data for men attending the Maricopa County STD clinic during the period from 1 October 2011 to 30 September 2013 were cross-matched with HIV surveillance data to identify men with HIV coinfection. We examined HIV status, HIV diagnosis date, and the values of VL collected nearest to the date of reported rectal infection.

RESULTS

During the 2-year time period, 1591 men were tested for rectal GC and CT. Of the men tested, 506 (31.8%) were positive for GC (13.2%), CT (12.2%) or both (6.4%); 119 (23.5%) of those with rectal GC or CT were coinfected with HIV. Among the 275 men with HIV at the time of rectal testing, 54 (19.6%) had no reported VL; 63 (22.9%) had an undetectable VL (< 20 HIV-1 RNA copies/mL) and 158 (57.4%) had a detectable VL collected within 1 year of rectal diagnosis. Mean VL was higher among HIV and rectal GC/CT coinfected cases compared with men with HIV alone (174 316 vs. 57 717 copies/mL, respectively; P = 0.04).

CONCLUSIONS

Approximately one-third of men undergoing rectal testing were positive for GC or CT and one-quarter of men with rectal GC or CT also had HIV infection. Of the HIV-infected men tested for rectal GC or CT, more than half had a detectable VL collected near the time of rectal testing, demonstrating a risk for transmitting HIV.

Astrocytic modulation of blood brain barrier: perspectives on Parkinson's disease

The blood–brain barrier (BBB) is a tightly regulated interface in the Central Nervous System (CNS) that regulates the exchange of molecules in and out from the brain thus maintaining the CNS homeostasis. It is mainly composed of endothelial cells (ECs), pericytes and astrocytes that create a neurovascular unit (NVU) with the adjacent neurons. Astrocytes are essential for the formation and maintenance of the BBB by providing secreted factors that lead to the adequate association between the cells of the BBB and the formation of strong tight junctions. Under neurological disorders, such as chronic cerebral ischemia, brain trauma, Epilepsy, Alzheimer and Parkinson’s Diseases, a disruption of the BBB takes place, involving a lost in the permeability of the barrier and phenotypical changes in both the ECs and astrocytes. In this aspect, it has been established that the process of reactive gliosis is a common feature of astrocytes during BBB disruption, which has a detrimental effect on the barrier function and a subsequent damage in neuronal survival. In this review we discuss the implications of astrocyte functions in the protection of the BBB, and in the development of Parkinson’s disease (PD) and related disorders. Additionally, we highlight the current and future strategies in astrocyte protection aimed at the development of restorative therapies for the BBB in pathological conditions.

NMDARs in neurological diseases: a potential therapeutic target

N-methyl-D-aspartate ionotropic glutamate receptor (NMDARs) is a ligand-gated ion channel that plays a critical role in excitatory neurotransmission, brain development, synaptic plasticity associated with memory formation, central sensitization during persistent pain, excitotoxicity and neurodegenerative diseases in the central nervous system (CNS). Within iGluRs, NMDA receptors have been the most actively investigated for their role in neurological diseases, especially neurodegenerative pathologies such as Alzheimer's and Parkinson's diseases. It has been demonstrated that excessive activation of NMDA receptors (NMDARs) plays a key role in mediating some aspects of synaptic dysfunction in several CNS disorders, so extensive research has been directed on the discovery of compounds that are able to reduce NMDARs activity. This review discusses the role of NMDARs on neurological pathologies and the possible therapeutic use of agents that target this receptor. Additionally, we delve into the role of NMDARs in Alzheimer's and Parkinson's diseases and the receptor antagonists that have been tested on in vivo models of these pathologies. Finally, we put into consideration the importance of antioxidants to counteract oxidative capacity of the signaling cascade in which NMDARs are involved.

Prediction of extracapsular disease with multiparametric magnetic resonance imaging in high risk localized prostate cancer patient

OBJECTIVES

To assess the usefulness of multiparametric magnetic resonance imaging (MRI) in the staging of patients with localized prostate cancer (PC) and high risk of extracapsular disease (ECD).

METHODS

Retrospective study including 30 patients with localized PC and high risk of ECD. Pathologist and radiologist established an ECD suspicion according to the evaluation of the prostatic biopsy specimens and the multiparametric MRI analysis, respectively. Radical prostatectomy (RP) specimen analysis was used as a definitive confirmatory reference. Kappa (k)test was used to assess the degree of consistency between the initial suspicion provided by both specialists and the reference RP specimen.

RESULTS

When the prostatic gland was analyzed as a single unit, the pathological evaluation of the biopsy specimens did not correctly detect the risk of ECD in 46.6% of the patients (14/30; 10 FN; k=-0.035, 95%CI [-0.29-0.36]), while multiparametric MRI did not do in 36% of the cases (11/30, 9 FP; k=0.27, 95%CI [-0.03-0.61]). Whereas, if each side of the prostate (i.e. right and left) was considered as an independent observation, the pathologist wrongly predicted the risk of ECD in 35% of the cases (21/60; 18 FN; k=0.19, 95%CI [-0.03-0.40]), while the radiologist erred only in 18.3% of the cases (11/60; 7 FN and 4 FP; k=0, 61, 95%CI [0.40-0.81]).

CONCLUSIONS

Data from our experience suggest an added value of multiparametric MRI in the clinical staging of localized PC in cases of high risk of ECD. Multiparametric MRI may be used as a helpful tool in the surgical planning and the decision-making process regarding the management of this entity.

Paracrine factors of human mesenchymal stem cells increase wound closure and reduce reactive oxygen species production in a traumatic brain injury in vitro model

Traumatic brain injury (TBI) consists of a primary and a secondary insult characterized by a biochemical cascade that plays a crucial role in cell death in the brain. Despite the major improvements in the acute care of head injury victims, no effective strategies exist for preventing the secondary injury cascade. This lack of success might be due to that most treatments are aimed at targeting neuronal population, even if studies show that astrocytes play a key role after a brain damage. In this work, we propose a new model of in vitro traumatic brain-like injury and use paracrine factors released by human mesenchymal stem cells (hMSCs) as a neuroprotective strategy. Our results demonstrate that hMSC-conditioned medium increased wound closure and proliferation at 12 h and reduced superoxide production to control conditions. This was accompanied by changes in cell morphology and polarity index, as both parameters reflect the ability of cells to migrate toward the wound. These findings indicate that hMSC is an important regulator of oxidative stress production, enhances cells migration, and shall be considered as a useful neuroprotective approach for brain recovery following injury.

Prolactin rescues and primes autoreactive B cells directly and indirectly through dendritic cells in B6.Sle3 mice

The lupus susceptibility interval Sle3/5 confers responsiveness to prolactin in C57BL/6 (B6) mice and hyperprolactinaemia induces a lupus-like phenotype in B6.Sel3/5 mice. In this study, the immunostimulatory effects of prolactin in B6 mice containing the Sle3 portion of the Sel3/5 interval (B6.Sle3 mice) were dissected. Because of the Sle3 interval's involvement in activation of myeloid cells, the effect of dendritic cells (DCs) from prolactin-treated B6.Sle3 mice on the phenotype of B6 mice was also evaluated. B cells from prolactin-treated B6 and B6.Sle3 mice and from B6 recipients of prolactin-modulated DCs from B6.Sle3 mice were tested for DNA-reactivity and resistance to B cell receptor (BCR)-mediated apoptosis. The expression of co-stimulatory molecules on lymphocytes and myeloid cells was also evaluated. In prolactin-treated B6.Sle3 mice, transitional type 2 B cells increased while type 1 B cells decreased as a consequence of prolactin-induced resistance to BCR-mediated apoptosis leading to the survival of DNA-reactive B cells. Follicular B cells from prolactin-treated mice expressed increased levels of CD40, B7·2 and IA(b), and DCs and monocytes had higher levels of CD44 and B7·2 than placebo-treated mice. Adoptive transfer of DCs from prolactin-treated B6.Sle3 mice to B6 recipients demonstrated the intrinsic ability of prolactin-modulated DCs to induce a development of lupus-like characteristics in B6 mice. Based on these results, prolactin accelerates the breakdown of immune tolerance in B6.Sle3 mice by promoting the survival, maturation and activation of autoreactive B cells, DCs and macrophages.

Abstract P6-05-02: Endocrine biomarkers in response to AR-inhibition with bicalutamide for the treatment of AR(+), ER/PR(−) metastatic breast cancer (MBC) (TBCRC011)

Background: Our group and others have identified a subset of ER/PR(−) breast cancers characterized by expression of the androgen receptor (AR) and androgen-dependent growth (Doane 2006). We conducted a proof-of-concept multicenter phase II study to test the efficacy of the AR-antagonist, bicalutamide for the treatment of AR(+) ER/PR(−) MBC (NCT00468715). Results of the primary endpoint, clinical benefit rate (CBR), were presented at ASCO (Gucalp 2012). Data for the impact of bicalutamide on circulating hormone levels in women are limited. Elevations in serum testosterone (T) and estradiol (E) have been observed for men treated with bicalutamide. We hypothesized comparable patterns of change in circulating endocrine markers in response to bicalutamide for women with MBC.

Methods: Patients (pts) with AR(+) (IHC ≥10%), ER/PR(−) (IHC &lt;10%) MBC were eligible for treatment (tx) if ECOG performance status ≤2 and normal organ function regardless of menopausal status. There was no limit to prior tx except prior trastuzumab required if HER2(+). Tx consisted of bicalutamide 150mg orally daily in 28-day cycles (C). Toxicity assessed q4 weeks, response q12wks. Primary endpoint was CBR. Peripheral blood was collected for total and free T, E and sex hormone binding globulin (SHBG) at baseline, start of C2 (C2) and at end of study (EOS). Standard institutional assays were used. A Wilcoxon signed-rank test was done to compare baseline to C2 and EOS values.

Results: 26 patients with AR(+) ER/PR(−) MBC were treated on study. Evaluable number (n) of pts at baseline, C2 and EOS are 26, 26 and 19 respectively. Two pts remain on study. Menopausal status: pre=2, post=24. Baseline median total and free T and estradiol were consistent with expected norms, however a wide range was observed (Table). There were no significant differences observed for median free T, total T, E or SHBG between baseline and C2 or baseline and EOS. Changes in hormone levels could not be stratified by menopausal status or response to bicalutamide given small sample size. Given the wide range of baseline values, we examined the percent change for each endocrine biomarker from baseline to C2 and EOS. As shown in the Table, there was no difference in median percent change observed across time points for each biomarker.

Abstract P6-11-10: IBL2001: Phase I/II study of a novel dose-dense schedule of oral indibulin for the treatment of metastastic breast cancer

Background: Indibulin (ZI0-301) is a novel, oral, synthetic small molecule microtubule inhibitor which binds tubulin at a different site than taxanes and vinca alkaloids. Preclinical data demonstrate indibulin does not interact with acetylated (neuronal) tubulins and in clinical studies has not exhibited the neurotoxicity associated with other tubulin binders. Indibulin has potent antitumor activity in human cancer cell lines, including multidrug-, taxane-, and vinblastine-resistant. Norton-Simon modeling based on cell line data suggested that dose dense (dd) administration could optimize efficacy while limiting toxicity.

Methods: Eligible patients (pts) have metastatic or unresectable locally advanced breast cancer, ECOG performance status ≤ 2, adequate organ function, measurable or nonmeasurable disease and any number of prior therapies. Uncontrolled gastrointestinal malabsorption syndrome and grade 2 or higher peripheral neuropathy are the principal exclusions. Adverse events (AEs) are graded by CTCAE v. 4.0. Objective disease status is evaluated according to RECIST 1.1. The primary objective of the phase (Ph) I portion of the study is to determine the maximum tolerated dose (MTD) of indibulin when given in dd fashion 5 days treatment, 9 days rest using standard 3+3 dose escalation schema.

Evaluation of progressive multifocal leukoencephalopathy treatments in a Spanish cohort of HIV-infected patients: do protease inhibitors improve survival regardless of central nervous system penetration-effectiveness (CPE) score?

OBJECTIVES

The aim of the study was to investigate whether survival after progressive multifocal leukoencephalopathy (PML) diagnosis in HIV-1-infected patients was associated with central nervous system penetration-effectiveness (CPE) score and the presence or absence of protease inhibitors in the treatment regimen.

METHODS

In the absence of treatments demonstrated to be effective for PML in HIV-1-infected patients and in the light of the controversy surrounding the use of CPE scores to make decisions on treatment after diagnosis, we determined whether there were differences in survival at 1 year depending on the type and characteristics of treatment. A multicentre retrospective observational study including three Spanish hospitals was carried out for the period from 1 January 1994 to 31 December 2009. Patients with a PML diagnosis were included in the study if they were symptomatic and met at least two of the following three criteria: (1) compatible radiological findings; (2) a positive polymerase chain reaction for John Cunningham virus (JCV) in the cerebrospinal fluid (CSF); (3) an absence of findings suggesting another infection in the central nervous system, after general CSF cultures for virus, bacteria and mycobacteria.

RESULTS

A total of 98 patients were included in the study; 24.5% were diagnosed in the period 1994-1999, 39.8% in 2000-2004 and 35.7% in 2005-2009. The median follow-up time was 363 days (interquartile range 108-1946 days). The median CD4 count was 76 cells/uL (interquartile range 30-166 cells/uL) and 62% of patients had an HIV viral load >50 HIV-1 RNA copies/ml. Thirty-eight per cent of patients received high-penetrance treatment, and 58% received treatment that included protease inhibitors. In the analysis of survival at 1 year, a higher CPE score did not result in an improvement in survival, but the presence of protease inhibitors in the regimen was associated with a statistically significant (P = 0.03) reduction in mortality (hazard ratio 0.40; 95% confidence interval 0.18-0.91).

CONCLUSIONS

We consider that the lower mortality observed in the protease inhibitor group may be clinically relevant, and, if this is the case, a treatment based on protease inhibitors may be indicated for patients diagnosed with PML.

Rumination, gender, and depressive symptoms associated with caregiving strain in bipolar disorder

OBJECTIVE

To evaluate the associations between indices of caregiving strain, ruminative style, depressive symptoms, and gender among family members of patients with bipolar disorder.

METHOD

One hundred and fifty primary caregivers of patients enrolled in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) participated in a cross-sectional study to evaluate the role of ruminative style in maintaining depressive symptoms associated with caregiving strain. Patient lifetime diagnosis and current episode status were evaluated by the Affective Disorder Evaluation and the Clinical Monitoring Form. Caregivers were evaluated within 30 days of the patient on measures of family strain, depressive symptoms, and ruminative style.

RESULTS

Men and women did not differ on depression, caregiver strain, or ruminative style scores. Scores suggest an overall mild level of depression and moderate caregiver strain for the sample. Greater caregiver strain was significantly associated (P<0.05) with rumination and level of depressive symptoms, controlling for patient clinical status and demographic variables. Rumination reduced the apparent association between strain and depression by nearly half. Gender was not significantly associated with depression or rumination.

CONCLUSION

Rumination helps explain depressive symptoms experienced by both male and female caregivers of patients with bipolar disorder. Interventions for caregivers targeted at decreasing rumination should be considered.