Brief report: Self-blame and PTSD symptoms in adolescents exposed to terrorism: Is school connectedness a mediator?

Previous research has shown that self-blame predicts increased risk of posttraumatic stress disorder (PTSD) in youth exposed to terrorism, but little is known about the factors mediating such relationship. This study aimed to explore whether school connectedness (SC) mediates the effect of self-blame on PTSD in 60 adolescents (aged 14–18 years) who survived the 2004 terrorist attack against school no. 1 in Beslan, Russia. Participants completed measures of coping, SC, and PTSD three years after the traumatic event. Endorsement of self-blaming behaviors was found to be significantly positively related to the presence of PTSD; self-blame was negatively associated with SC, which in turn was negatively related to PTSD. The mediation hypothesis was supported, with SC partially mediating the link between self-blame and PTSD. Adolescents affected by terrorism may benefit from school-based interventions aimed at fostering students' sense of belonging and emotional bonding to teachers, peers, and the school environment.     

Protein Kinase C ζ Isoform is Critical for Proliferation in Human Glioblastoma Cell Lines

Previous studies have confirmed that proliferation in glioblastoma cell lines can be blocked by non-isoform specific protein kinase C (PKC) inhibitors, e.g calphostin C, staurosporine. However, the exact mechanism of PKC involvement is poorly understood. The aim of this study was to explore the role of specific PKC isoforms in the aberrant growth of glioblastoma. Identification of the isoform(s) critical for proliferation in glioblastoma would present a better target for the design of chemotherapeutic strategies. To this end, we screened expression on PKC isoforms in four human glioblastoma cell lines both when proliferating and in a quiescent state using western assays. PKC isoforms , I, II and were found to be expressed in all cell lines. PKC was detected in three out of four cell lines and PKC was detected in one out of four cell lines. Quiescence of growth resulted in down-regulation of PKC. We examined the role of these isoforms by studying the effect of PKC isoform-specific inhibitors bisindolylmaleimide-I and Gö6976 on proliferation in a panel of four human glioblastoma cell lines. Inhibition of PKC and had no effect on proliferation, suggesting that previous studies targeting PKC may not be of therapeutic benefit. More significantly, it was shown that inhibition of PKC blocked proliferation. This suggests that the inhibition of PKC may be an important chemotherapeutic target for arresting growth in glioblastoma.     

Preoperative clonidine blunts hyperadrenergic and hyperdynamic responses to prolonged tourniquet pressure during general anesthesia

Although the mechanism of tourniquet-induced hypertension is still unclear, plasma norepinephrine concentrations continuously increase in parallel to arterial blood pressure during tourniquet inflation. Clonidine attenuates hyperadrenergic and hyperdynamic responses. We investigated the effects of clonidine on prolonged tourniquet inflation. Twenty-nine patients scheduled for elective orthopedic surgery were randomly assigned to receive IV clonidine (3 microg/kg; n = 14) or placebo (n = 15) before tourniquet inflation of the lower limbs under general anesthesia in a double-blinded manner. Arterial blood pressure, heart rate, epinephrine, and norepinephrine plasma concentrations were measured before tourniquet inflation, 60 min after tourniquet inflation, just before tourniquet deflation, and 20 min after tourniquet deflation. Mean arterial blood pressure and norepinephrine plasma-concentrations were significantly lower in the Clonidine group compared with Control after 60 min tourniquet inflation (P = 0.016; P = 0.006). Immediately before deflation of the tourniquet, the difference for mean arterial pressure between groups was even more pronounced (P = 0.005). Twenty minutes after deflation mean arterial blood pressure in the Control group was still increased and significantly higher compared with the Clonidine group (P = 0.002). In conclusion, preoperative IV clonidine blunts hyperadrenergic and hyperdynamic responses resulting from prolonged tourniquet inflation under general anesthesia in ASA class I--II patients. IMPLICATIONS: Tourniquet inflation is associated with a continuous increase in arterial blood pressure and sympathetic outflow. This study shows that IV clonidine effectively blunts increases of both arterial blood pressure and plasma norepinephrine concentrations.     

Decrease of carbohydrate in membrane glycoproteins during human erythrocyte ageing in vivo

Membrane glycoproteins from young human erythrocytes and erythrocytes aged in vivo were fractionated by gel filtraton. Three major groups of glycoproteins were obtained.The neutral hexoses and sialic acid contents of each group of glycoproteins from the old cells were found to be significantly reduced by comparison to the values found in the glycoproteins of the young cells. Thus, the previously observed decrease in neutral hexoses and in sialic acid contents of the full erythrocyte membrane during in vivo ageing does not affect only one particular group of glycoproteins but each of the groups of glycoproteins tested, including the major glycoproteins of the erythrocyte membrane, that is to say glycophorins.It is shown in addition, that the previously observed decrease per cell of the surface galactose and N-acetylgalactosamine residues of the ageing erythrocyte affect several groups of membrne glycoproteins including band 3, PAS-1, PAS-4 and PAS-3.The physiological significance of these experimental data is discussed.     

Bone turnover markers for osteoporotic status assessment? A systematic review of their diagnosis value at baseline in osteoporosis

ObjectiveOsteoporosis diagnosis is based on bone mineral density (BMD) but bone remodeling is also a crucial issue. It can be assessed by bone turnover markers (BTMs). Their interest for the positive and etiological diagnosis of osteoporosis at baseline, and their predictive value for past asymptomatic vertebral fractures, were evaluated by a systematic review of the literature.MethodsMedline database was searched to identify all published reports analyzing BTMs and BMD or fractures. We conducted meta-analyses on BTMs levels according to osteoporotic status using random effects models.ResultsModerate and negative correlations were found, mainly in postmenopausal women, between BTMs and BMD, especially with bone alkaline phosphatase (bone ALP), osteocalcin, serum C-terminal and urine N-terminal crosslinking telopeptides of type I collagen (sCTX and uNTX). Bone ALP and sCTX levels are higher in osteoporotic patients compared to controls. High levels of bone ALP in primary hyperparathyroidism and low levels of osteocalcin in endogenous hypercorticism are the most relevant data reported in endocrine diseases associated with osteoporosis. High levels of BTMs, especially osteocalcin, bone ALP or sCTX, may be associated with prevalent vertebral fractures.ConclusionThe diagnosis value of BTMs at baseline in osteoporosis is very low. The interest of BTMs for the etiological diagnostic of secondary osteoporosis has not been demonstrated. Data are lacking to address the interest of BTMs assessment to screen for vertebral fractures in asymptomatic patients with high risk factors of fractures.