β-endorphin degradation and the individual reactivity to traumatic stress

Reactivity to traumatic stress varies between individuals and only a minority of those exposed to trauma develops stress-induced psychopathologies. Currently extensive effort is made to unravel the specific mechanisms predisposing to vulnerability vs. resilience to stress. We investigated in rats the role of β-endorphin metabolism in vulnerability to acute traumatic stress. Responders (showing extreme anxiety; n=7) and resilient non-responders (not differing from the non-stressed individuals; n=8) to traumatic foot-shock stress were compared for their blood levels of stress hormones as well as brain levels and activity of two opioid-degrading enzymes. β-endorphin is a substrate to insulin degrading enzyme, which also degrades insulin. Therefore, the effects of insulin application on behavioral and hormonal responses and on β-endorphin degradation were tested. Pre- and post-stress levels of serum corticosterone, and post-stress plasma β-endorphin concentration differentiated between the responders and the non-responders. In brain, responders showed enhanced degradation rates of β-endorphin, assessed by Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS), in hippocampal and amygdalar slices as compared to non-responders. Application of insulin to the amygdala, prior to exposure to traumatic stress, reduced post-stress anxiety and serum corticosterone levels only in the responders. In parallel, amygdalar β-endorphin degradation rate was also reduced by insulin. These results suggest that slowing down β-endorphin degradation rate may constitute an integral part of the normal stress-response, upon a failure of which an extreme anxiety develops. Modulation of opioid degradation may thus present a potential novel target for interference with extreme anxiety.     

First case of childhood Takayasu arteritis with renal artery aneurysms

Takayasu arteritis is a large vessel systemic granulomatous vasculitis characterized by stenosis or obliteration of large and medium sized arteries. It commonly involves elastic arteries such as the aorta and its main branches. Renal artery involvement is rare and has not been reported in a child. We report a 12-year-old boy with Takayasu arteritis who developed severe hypertension, proteinuria, microscopic hematuria and renal dysfunction. Conventional angiography demonstrated aneurysms of both renal arteries and multiple microaneurysms of the superior mesenteric artery. This case report illustrates that the children with Takayasu arteritis can develop renal involvement resulting in hematuria, proteinuria and even renal failure.     

Systemic therapy in the management of metastatic or advanced salivary gland cancers

Salivary gland cancers are very rare tumors. They are characterized by a histologic heterogeneity and a poor outcome. According to this rarity, few prospective data are available to date. No standard recommendations could be held for the use of systemic therapy in these tumors. Several case reports and small studies have investigated the contribution of different agents of chemotherapy. With the extension of molecular biology approach in oncology several signaling pathways have been discovered in different cancers including salivary gland cancers; thus a number of targeted therapies have been investigated. This paper reviewed exhaustively the studies investigating the role of systemic therapies (chemotherapy, targeted therapy, hormone therapy) in salivary gland cancers.     

Wireless,accelerometry-triggered functional electrical stimulation of the peroneal nerve in spastic paresis: A randomized,controlled pilot study

In hemiparesis, Wireless, Accelerometry-Triggered Functional Electrical Stimulation (WAFES) of the common peroneal nerve may hold intrinsic rehabilitative properties. The present pilot study analyzes WAFES against conventional therapy. Twenty adults with chronic hemiparesis (time since lesion 7(6) years; median (interquartile range)) were randomized into 2 10-week rehabilitation programs: a 45-minute (min) daily walk using WAFES (n = 10) and conventional physical therapy (CPT), 3 × 45 min per week (n = 10). The outcomes were 3D sagittal speed measurements, step length, cadence, maximal amplitude and velocity of hip, knee, and ankle during gait at free and fast speed without WAFES and clinical assessments of plantar flexor angles of shortening, spasticity, and weakness, before (D1) and after the program (W10). Kinematic and spasticity improvements occurred in the WAFES group only: (i) ankle dorsiflexion velocity (D1 versus W10, free speed, WAFES, +4(5)°/sec, p = 0.002; CPT, ?3(8)°/sec, p = 0.007; fast, WAFES, +8(6)°/sec, p = 0.03; CPT, ?1(4)°/sec, NS); (ii) maximal passive ankle dorsiflexion (WAFES,+26(85)%; CPT,+0(27)%; group-visit, p = 0.007) and knee flexion (WAFES, +13(17)%; CPT, ?1(11)%; group-visit, p = 0.006) at fast speed only; (iii) 15% plantar flexor spasticity grade reduction with WAFES. Over 10 weeks, gait training using WAFES improved ankle and knee kinematics and reduced plantar flexor spasticity compared with CPT. Studies with longer WAFES use should explore functional effects.     

Oxidative stress and glutathione S-transferase genetic polymorphisms in medical staff professionally exposed to ionizing radiation

Purpose: Ionizing radiation (IR) is considered as a diagnostic and therapeutic tool in medicine. However, chronic occupational exposure of medical staff to IR may affect the antioxidant status and, as a result, DNA damage and cancers as well. The objective of our study was to evaluate the oxidative stress profile caused by IR in 29 Tunisian medical staff from radiology and radiotherapy departments, and to find an association between the GSTM1 null, GSTT1 null, and GSTP1 Ile105Val polymorphisms and oxidative stress biomarkers.

Materials and methods: The oxidant biomarkers malondialdehyde (MDA) and advanced oxidation protein product (AOPP) and the activities of the antioxidant superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) enzymes were spectrophotometrically determined in erythrocytes hemolysates. The analysis of GSTT1 null, GSTM1 null, and GSTP1 Ile105Val polymorphisms was determined for each participant using PCR methods.

Results: A significant increase of white blood cell (WBC) numbers (p?<?.05) and a significant decrease by 11% of hemoglobin (Hb) (p?<?.01) were noted in the exposed subjects in our study. Moreover, we report a significant increase of MDA level and the activities of SOD and CAT enzymes of the IR-exposed group compared to controls (p?<?.001). Interestingly, a close association was noted between the genotypes GSTP1 low active, GSTT1 null, GSTM1 null, and both GSTT1/GSTM1 null and oxidative stress biomarkers, especially with MDA level, SOD, and CAT activities.

Conclusions: Our findings indicate that the medical staff exposed to low IR levels were under risk of significant oxidative stress that was enhanced by their glutathione S-transferase (GST) polymorphisms.     

Improving the Validity of Peripheral Venous Blood Gas Analysis as an Estimate of Arterial Blood Gas by Correcting the Venous Values with SvO2

Background

Peripheral venous blood gas (pVBG) analysis in replacement of arterial blood gas (ABG) is limited by the unpredictable differences between arterial and venous values, especially for PCO₂ and pH (ΔPCO₂ and ΔpH).

Objectives

We hypothesized that, using the theoretical relationship linking SvO₂ and blood flow, we could diminish the effect of local circulatory conditions on ΔPCO₂ and ΔpH and thereby increase pVBG validity.

Methods

This was a prospective cross-sectional study performed in emergency patients requiring a blood gas analysis in which ABG and pVBG were performed simultaneously. The data of 50 randomly selected patients (model group) were used for developing two equations to correct PvCO₂ and pHv according to the peripheral SvO₂ (SpvO₂) level. The formulas derived were PvCO_2cor = PvCO₂ − 0.30 × (75 − SpvO₂), and pHv_cor = pHv + 0.001 × (75 − SpvO₂). The validity of the corrected values was then tested on the remaining population (validation group).

Results

There were 281 patients included in the study, mainly for dyspnea. ΔPCO₂ and ΔpH were strongly correlated with SpvO₂ (r² = 0.62 and r² = 0.53, respectively, p < 0.001). Using the data of the model group, we developed equations that we applied on the validation group. We found that the corrected values were more valid than the raw values for detecting a PaCO₂ > 45 mm Hg (AUC ROC = 0.96 ± 0.01 vs. 0.89 ± 0.02, p < 0.001), a PaCO₂ < 35 mm Hg (AUC = 0.95 ± 0.02 vs. 0.84 ± 0.03, p < 0.001), a pHa < 7.35 (AUC = 0.97 ± 0.01 vs. 0.95 ± 0.02, p < 0.05), or a pHa > 7.45 (AUC = 0.91 ± 0.02 vs. 0.81 ± 0.04, p < 0.001).

Conclusions

The variability of ΔPCO₂ and ΔpH is significantly lowered when the venous values are corrected according to the SpvO₂ value, and pVBG is therefore more accurate and valid for detecting an arterial abnormality.     

Clinical and single-photon emission computed tomography study of pure akinesia with freezing of gait

The clinical syndrome of pure akinesia (PA) is considered the third phenotype of progressive supranuclear palsy (PSP), and is characterized by freezing of gait and prominent speech disturbance without rigidity or tremor. It is frequently considered one of the dopamine resistant motor syndromes, and its pathophysiology remains unclear. We report a patient followed in the Department of Neurology of Razi Hospital, Tunisia, with PA with gait freezing (PAGF) with a frontal hypoperfusion on single photon emission CT and non-responsive dopa therapy. We discuss the clinical features of PAGF and efficiency of treatment options.