ATF6 protects against protein misfolding during cardiac hypertrophy

Cardiomyocytes activate the unfolded protein response (UPR) transcription factor ATF6 during pressure overload-induced hypertrophic growth. The UPR is thought to increase ER protein folding capacity and maintain proteostasis. ATF6 deficiency during pressure overload leads to heart failure, suggesting that ATF6 protects against myocardial dysfunction by preventing protein misfolding. However, conclusive evidence that ATF6 prevents toxic protein misfolding during cardiac hypertrophy is still pending. Here, we found that activation of the UPR, including ATF6, is a common response to pathological cardiac hypertrophy in mice. ATF6 KO mice failed to induce sufficient levels of UPR target genes in response to chronic isoproterenol infusion or transverse aortic constriction (TAC), resulting in impaired cardiac growth. To investigate the effects of ATF6 on protein folding, the accumulation of poly-ubiquitinated proteins as well as soluble amyloid oligomers were directly quantified in hypertrophied hearts of WT and ATF6 KO mice. Whereas only low levels of protein misfolding was observed in WT hearts after TAC, ATF6 KO mice accumulated increased quantities of misfolded protein, which was associated with impaired myocardial function. Collectively, the data suggest that ATF6 plays a critical adaptive role during cardiac hypertrophy by protecting against protein misfolding.

Current approaches in glioblastoma multiforme immunotherapy

Glioblastoma multiform (GBM) is the most prevalent CNS (central nervous system) tumor in adults, with an average survival length shorter than 2 years and rare metastasis to organs other than CNS. Despite extensive attempts at surgical resecting, the inherently permeable nature of this disease has rendered relapse nearly unavoidable. Thus, immunotherapy is a feasible alternative, as stimulated immune cells can enter into the remote and inaccessible tumor cells. Immunotherapy has revolutionized patient upshots in various malignancies and might introduce different effective ways for GBM patients. Currently, researchers are exploring various immunotherapeutic strategies in patients with GBM to target both the innate and acquired immune responses. These approaches include reprogrammed tumor-associated macrophages, the use of specific antibodies to inhibit tumor progression and metastasis, modifying tumor-associated macrophages with antibodies, vaccines that utilize tumor-specific dendritic cells to activate anti-tumor T cells, immune checkpoint inhibitors, and enhanced T cells that function against tumor cells. Despite these findings, there is still room for improving the response faults of the many currently tested immunotherapies. This study aims to review the currently used immunotherapy approaches with their molecular mechanisms and clinical application in GBM.

mTORC1 inhibition impairs activation of the unfolded protein response and induces cell death during ER stress in cardiomyocytes

The mechanistic target of rapamycin complex 1 (mTORC1) is a central regulator of protein synthesis that senses and responds to a variety of stimuli to coordinate cellular metabolism with environmental conditions. To ensure that protein synthesis is inhibited during unfavorable conditions, translation is directly coupled to the sensing of cellular protein homeostasis. Thus, translation is attenuated during endoplasmic reticulum (ER) stress by direct inhibition of the mTORC1 pathway. However, residual mTORC1 activity is maintained during prolonged ER stress which is thought to be involved in translational reprogramming and adaption to ER stress. By analyzing the dynamics of mTORC1 regulation during ER stress, we unexpectedly found that mTORC1 is transiently activated in cardiomyocytes within minutes at the onset of ER stress before being inhibited during chronic ER stress. This dynamic regulation of mTORC1 appears to be mediated, at least in part, by ATF6, as its activation was sufficient to induce the biphasic control of mTORC1. We further showed that protein synthesis remains dependent on mTORC1 throughout the ER stress response and that mTORC1 activity is essential for posttranscriptional induction of several unfolded protein response elements. Pharmacological inhibition of mTORC1 increased cell death during ER stress, indicating that the mTORC1 pathway serves adaptive functions during ER stress in cardiomyocytes potentially by controlling the expression of the protective unfolded protein response.

Effects of Acute Potassium Chloride Administration on Ventricular Dysrhythmias after Myocardial Infarction in a Rat Model of Ischemia/Reperfusion

Background: Acute myocardial infarction is an important cause of morbidity. This study aimed to investigate the effects of the administration of potassium chloride (KCl) on reperfusion-induced injuries in a rat model of myocardial ischemia/reperfusion. Methods: Thirty-six male Wistar rats, weighing 200 to 250 g, were randomly assigned to 3 experimental groups: control, K1 (10 µg/kg of KCl), and K2 (20 µg/kg of KCl). Twenty minutes before ischemia, a single dose of 10 and 20 µg/kg of KCl was intraperitoneally administered in the K1 and K2 groups, respectively. The coronary artery was occluded for 30 minutes (ischemia); thereafter, it was opened for 60 minutes (reperfusion) to measure hemodynamic parameters and ventricular arrhythmias. Blood sampling was performed after the reperfusion period to determine the serum levels of lactate dehydrogenase, troponin I, creatine kinase (CK)-MB, malondialdehyde, and pro-oxidant-antioxidant balance. Results: Serological parameters significantly decreased in the potassium groups compared with the control group. In particular, the decline was more pronounced for the serum levels of lactate dehydrogenase (1180.25±69.48 vs 1556.67±77.02 U/L; P=0.011), troponin I (21.98±0.61 vs 28.76±1.65 ng/mL; P=0.020), and pro-oxidant-antioxidant balance (15.51±0.72 vs 20.63±1.42 HK; P=0.041) in the K2 group compared with the K1 group. Moreover, the administration of 20 µg/kg of KCl significantly decreased the incidence of ventricular tachycardias and fibrillations compared with the control group (P=0.002). Additionally, no considerable differences were observed between the control group and the groups with 10 µg/kg and 20 µg/kg of KCl regarding the number of ventricular ectopic beats.  Conclusion: The administration of KCl before ischemia could reduce ventricular arrhythmias and reperfusion-induced injuries by reducing oxidative stress.

Brain aging in major depressive disorder

Depression and anxiety are common and often comorbid mental health disorders that represent risk factors for aging-related conditions. Brain aging has shown to be more advanced in patients with Major Depressive Disorder (MDD). Here, we extend prior work by investigating multivariate brain aging in patients with MDD and/or anxiety disorders and examine which factors contribute to older appearing brains. Adults aged 18-57 years from the Netherlands Study of Depression and Anxiety underwent structural MRI. A pre-trained brain age prediction model based on >2,000 samples from the ENIGMA consortium was applied to obtain brain-predicted age differences (brain-PAD, predicted brain age minus chronological age) in 65 controls and 220 patients with current MDD and/or anxiety. Brain-PAD estimates were associated with clinical, somatic, lifestyle, and biological factors. After correcting for antidepressant use, brain-PAD was significantly higher in MDD (+2.78 years, Cohen’s d=0.25, 95% CI -0.10-0.60) and anxiety patients (+2.91 years, Cohen’s d=0.27, 95% CI -0.08-0.61), compared to controls. There were no significant associations with lifestyle or biological stress systems. A multivariable model indicated unique contributions of higher severity of somatic depression symptoms (b=4.21 years per unit increase on average sum score) and antidepressant use (-2.53 years) to brain-PAD. Advanced brain aging in patients with MDD and anxiety was most strongly associated with somatic depressive symptomatology. We also present clinically relevant evidence for a potential neuroprotective antidepressant effect on the brain-PAD metric that requires follow-up in future research.

The combination effect of Prominin1 (CD133) suppression and Oxaliplatin treatment in colorectal cancer therapy

Colorectal cancer (CRC) is considered one of the leading types of cancer in the world. CD133, as a cancer stem cell marker, has a pivotal role in the development of drug resistance, migration, and stemness properties of CRC cells. This study was designed to check the combined effect of CD133 siRNA and Oxaliplatin on proliferation, migration, apoptosis, and stemness properties of CRC cells in the HT-29 cell line. MTT assay was performed to define the combined effect of CD133 siRNA and Oxaliplatin on the viability of HT-29 cells, and it showed that the combination of CD133 siRNA and Oxaliplatin could reduce the IC50 of this drug from 32.85 to 19.75 nmol. In order to figure out the effect of this combination therapy on CD133 expression at the gene and protein level, qRT-PCR and western blot were exploited, respectively. The results demonstrated that the silencing of CD133 could reduce the relative expression of this marker to about 0.00001 compared to the control group and reduce the protein level to 0.01. The ability of cell migration was tested by wound healing assay as well. Also, colony formation and sphere formation were conducted to assess the stemness properties in the combination group. Flow cytometry was conducted to investigate the apoptosis (15%), cell cycle (about 10% arresting in G0-G1 phase), and surface expression of CD133 in different groups (from 39.3% in the control group to 2.41 in the combination group). Finally, the expression of migration-, and stemness-associated genes were measured by qRT-PCR. We indicated that silencing of CD133 reduces the migration and stemness properties of colorectal cancerous cells. This suppression makes HT-29 cells more sensitive to Oxaliplatin and reduces the effective dose of this chemical drug. Therefore, the suppression of CD133 in combination with Oxaliplatin treatment might be a promising therapeutic approach in the treatment of colorectal cancer.

Cardioprotective effects of acute sleep deprivation on ischemia/reperfusion injury

OBJECTIVES

Modulation of sympathetic activity during acute sleep deprivation can produce various effects on body functions. We studied the effects of acute sleep deprivation before ischemia/reperfusion on myocardial injury in isolated rat hearts, and the role of sympathetic nervous system that may mediate these sleep deprivation induced effects.

METHODS

The animals were randomized into four groups (n = 11 per group): Ischemia- Reperfusion group (IR), Acute sleep deprivation group (SD), Control group for sleep deprivation (CON-SD) and Sympathectomy + ASD group (SYM-SD). In SD group, sleep deprivation paradigm was used 24 h prior to induction of ischemia/reperfusion. In SYM-SD group, the animals were chemically sympathectomized using 6-hydroxydopamine, 24 h before sleep deprivation. Then, the hearts of animals were perfused using Langendorff setup and were subjected to 30 min regional ischemia followed by 60 min of reperfusion. Throughout the experiment, the hearts were allowed to beat spontaneously and left ventricular developed pressure (LVDP) and rate pressure product (RPP) were recorded. At the end of study, infarct size and percentage of the area at risk were determined.

RESULTS

We found that SD increased LVDP and RPP, while reducing the myocardial infarct size. Moreover, sympathectomy reversed SD induced reduction in infarct size and showed no differences as compared to IR.

CONCLUSION

This study shows cardioprotective effects of acute sleep deprivation, which can be abolished by chemical sympathectomy in isolated hearts of rats.

CD133 suppression increases the sensitivity of prostate cancer cells to paclitaxel

One of the major barriers in cancer therapy is the resistance to conventional therapies and cancer stem cells (CSCs) are among the main causes of this problem. CD133 as a CSC marker displays stem cell-like properties, tumorigenic capacity, and drug resistance in various cancers. However, the molecular mechanism behind CD133 function in prostate cancer (PC) still remains unclear. This research aimed to illustrate the probabilistic mechanism of CD133-siRNA and paclitaxel in the reduction of chemoresistance in PC cells. To measure the cell viability, migratory capacity, CSCs properties, invasive potential, apoptosis and cell cycle progression of the cells, the MTT, wound healing, spheroid assay, colony formation assay, DAPI staining and flow cytometry assays were applied in the LNCaP cell line, respectively. Also, quantitative real-time PCR (qRT-PCR) and western blot method were used for measuring the expression of CD133 and the effects of CD133 silencing on the AKT/mTOR/c-myc axis and pro-metastatic genes expression. We showed that the CD133-siRNA considerably decreased the CD133 expression. Moreover, CD133-siRNA and paclitaxel treatment significantly decreased cell proliferation and also inhibited the ability of cell migration and invasion and reduced pro-metastatic genes expression. Additionally, we found that the simultaneous use of CD133-siRNA and paclitaxel increased the paclitaxel-induced apoptosis. Our results confirmed that CD133 silencing combined with paclitaxel synergistically could suppress cell migration, invasion, and proliferation and enhance the chemosensitivity compared with mono treatment. Therefore, CD133 silencing therapy could be viewed as a promising and efficient strategy in PC targeted therapies.

New emerging roles of CD133 in cancer stem cell: Signaling pathway and miRNA regulation

Cancer stem cells (CSC) are rare immortal cells within a tumor that are able to initiate tumor progression, development, and resistance. Advances studies show that, like normal stem cells, CSCs can be both self-renewed and given rise to many cell types, therefore form tumors. A number of cell surface markers, such as CD44, CD24, and CD133 are frequently used to identify CSCs. CD133, a transmembrane glycoprotein, either alone or in collaboration with other markers, has been mainly considered to identify CSCs from different solid tumors. However, the exactness of CD133 as a cancer stem cell biomarker has not been approved yet. The clinical importance of CD133 is as a CSC marker in many cancers. Also, it contributes to shorter survival, tumor progression, and tumor recurrence. The expression of CD133 is controlled by many extracellular or intracellular factors, such as tumor microenvironment, epigenetic factors, signaling pathways, and miRNAs. In this study, it was attempted to determine: 1) CD133 function; 2) the role of CD133 in cancer; 3) CD133 regulation; 4) the therapeutic role of CD133 in cancers.

Acute sleep deprivation preconditions the heart against ischemia/ reperfusion injury: the role of central GABA-A receptors

OBJECTIVES

Central γ-aminobutyric acid (GABA) neurotransmission modulates cardiovascular functions and sleep. Acute sleep deprivation (ASD) affects functions of various body organs via different mechanisms. Here, we evaluated the effect of ASD on cardiac ischemia/reperfusion injury (IRI), and studied the role of GABA-A receptor inhibition in central nucleus of amygdala (CeA) by assessing nitric oxide (NO) and oxidative stress.

MATERIALS AND METHODS

The CeA in sixty male Wistar rats was cannulated for saline or bicuculline (GABA-A receptor antagonist) administration. All animals underwent 30 min of coronary occlusion (ischemia), followed by 2 hr reperfusion (IR). The five experimental groups (n=12) included are as follows: IR: received saline; BIC+IR: received Bicuculline; MLP+IR: received saline, followed by the placement of animals in an aquarium with multiple large platforms; ASD+IR: underwent ASD in an aquarium with multiple small platforms; and BIC+ASD+IR: received bicuculline prior to ASD.

RESULTS

Bicuculline administration increased the malondialdehyde levels and infarct size, and decreased the NO metabolites levels and endothelial nitric oxide synthase (eNOS) gene expression in infarcted and non-infarcted areas in comparison to IR group. ASD reduced malondialdehyde levels and infarct size and increased NO metabolites, corticosterone levels and eNOS expression in infarcted and non-infarcted areas as compared to the IR group. Levels of malondialdehyde were increased while levels of NO metabolites, corticosterone and eNOS expression in infarcted and non-infarcted areas were reduced in the BIC+ASD+IR as compared to the ASD+IR group.

CONCLUSION

Blockade of GABA-A receptors in the CeA abolishes ASD-induced cardioprotection by suppressing oxidative stress and NO production.

Social functioning in patients with depressive and anxiety disorders

OBJECTIVE

Adaptive social functioning is severely impeded in depressive and anxiety disorders, even after remission. However, a comprehensive overview is still lacking.

METHOD

Using data from the Netherlands Study of Depression and Anxiety (NESDA), behavioural (network size, social activities, social support) and affective (loneliness, affiliation, perceived social disability) indicators of social functioning were analyzed in patients with anxiety (N = 540), depressive (N = 393), comorbid anxiety and depressive disorders ('comorbid', N = 748), remitted participants (N = 621), and healthy control subjects (N = 650).

RESULTS

Analyses revealed an increasing trend of social dysfunction among patient groups, in patients with comorbid anxiety and depressive disorders, showing the most severe impairments, followed by depressed and anxious patients (P's < 0.001 for all social functioning indicators). Affective indicators showed the largest effect sizes (Cohen's d range from 0.13 to 1.76). We also found impairments in social functioning among remitted patients. Furthermore, perceived social disability among patients was predictive of still having a depressive and/or anxiety diagnosis 2 years later (P < 0.01).

CONCLUSIONS

Behavioural but especially affective indicators of social functioning are impaired in patients with anxiety or depressive disorders and most in patients with comorbid disorders. After remission of affective psychopathology, residual impairments tend to remain, while social dysfunction in patients seems predictive of future psychopathology.

Post-infarct sleep disruption and its relation to cardiac remodeling in a rat model of myocardial infarction

Sleep disruption after myocardial infarction (MI) by affecting ubiquitin-proteasome system (UPS) is thought to contribute to myocardial remodeling and progressive worsening of cardiac function. The aim of current study was to test the hypothesis about the increased risk of developing heart failure due to experience of sleep restriction (SR) after MI. Male Wistar rats (n = 40) were randomly assigned to four experimental groups: (1) Sham, (2) MI, (3) MI and SR (MI + SR) (4) Sham and SR (Sham + SR). MI was induced by permanent ligation of left anterior descending coronary artery. Twenty-four hours after surgery, animals were subjected to chronic SR paradigm. Blood sampling was performed at days 1, 8 and 21 after MI for determination of serum levels of creatine kinase-MB (CK-MB), corticosterone, malondialdehyde (MDA) and nitric oxide (NO). Finally, at 21 days after MI, echocardiographic parameters and expression of MuRF1, MaFBx, A20, eNOS, iNOS and NF-kB in the heart were evaluated. We used H&E staining to detect myocardial hypertrophy. We found out that post infarct SR increased corticosterone levels. Our results highlighted deteriorating effects of post-MI SR on NO production, oxidative stress, and echocardiographic indexes (p < 0.05). Moreover, its detrimental effects on myocardial damage were confirmed by overexpression of MuRF1, MaFBx, iNOS and NF-kB (p < 0.001) in left ventricle and downregulation of A20 and eNOS (p < 0.05). Furthermore, histological examination revealed that experience of SR after MI increased myocardial diameter as compared to Sham subjects (p < 0.05). Our data suggest that SR after MI leads to an enlargement of the heart within 21 days, marked by an increase in oxidative stress and NO production as well as an imbalance in UPS that ultimately results in cardiac dysfunction and heart failure.

Depressed Immune Responses and Accelerated Splenic Apoptosis due to Experience of Food Deprivation and Inequality but not Unstable Social Status in Balb/c Mice

OBJECTIVE(S)

We aimed to show that the immune system is sensitive to the detrimental effects of inequality and social injustice, and splenic vulnerability to apoptosis may also increase.

METHODS

In order of better determination of immune responses to chronic social stress, we implemented food deprivation, food intake inequality, and unstable social status (a change of cage-mate every 3 days) for a period of 14 days in 60 male Balb/c mice. At the end of this stress period, nitric oxide (NO) production by peritoneal adherent cells and the serum concentration of corticosterone were measured. Moreover, the viability of peritoneal adherent cells and spleen lymphocytes was evaluated by MTT assay. The terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay was done to reveal the TUNEL-reactive apoptotic bodies in the spleen.

RESULTS

Our results showed that food deprivation and inequality caused significant changes in the apoptosis of splenic cells in comparison with the control group (p < 0.05). Moreover, the vital activities of lymphocytes and peritoneal adherent cells, as well as NO production by the latter, increased significantly (p < 0.05). However, the experience of unstable social status did not cause a further increase in the viability of lymphocytes and peritoneal adherent cells, or NO production in animals that were food-deprived or experienced inequality. Serum concentration of corticosterone in all experimental groups, except for animals that experienced unstable social status only, significantly decreased versus the control group (p < 0.05).

CONCLUSIONS

The results suggest that poverty and social inequality, but not unstable social status, affect immune responses and are likely involved in the induction of splenic apoptosis in mice.

Conserved OprF as a Selective Immunogen against Pseudomonas aeruginosa

BACKGROUND & OBJECTIVES

Due to the importance of Pseudomonas aeruginosa in severe inpatient infections and high mortality, the need for an efficient vaccine against these bacteria is increasing. In this regard, the general outer membrane porin of the most problematic microorganism P. aeruginosa, outer membrane protein F (OprF), is a good vaccine candidate.

METHODS

The databank of NCBI was used to retrieve protein sequences recorded for OprF in P. aeruginosa.The current study aimed at investigating the conservation of the OprF in 150 reference sequences, clinical, and environmental strains of P. aeruginosa from different countries via bioinformatic tools.T-COFFEE and PRALINE software were used for alignment.

RESULTS

Of these, 134 strains were isolated from clinical specimens and other strains from environmental samples. Evaluation of alignment by the mentioned software clearly showed that this protein was conserved. Antigenicity and grand average of hydropathicity were favorable.

CONCLUSION

Conservation of OprF in all pathogenic and environmental strains of P. aeruginosa indicated that it can be considered as a good immunogen; however, the protectivity of OprF should be validated experimentally.

Epidemiology and trend of common cancers in Iran (2004-2008)

BACKGROUND

Cancer is one of the most important causes of mortality worldwide. It includes approximately 13% of death cases. This study aimed to investigate the incidence trend of common cancers in Iran during 2004-2008 to improve reporting distribution the disease.

METHODS

This was a retrospective study. The study population was all cases of cancer diagnosed in Iran during 2004-2008. The crude incidence rate of cancers was calculated per 100 000 people by age groups and sex. Age-standardised incidence rates (ASRs) were calculated using direct standardisation and the world standard population. Data were analysed using SPSS (version 17) and Microsoft Office Excel 2007.

RESULTS

In this study, a total of 301 055 cases of cancer were diagnosed. ASRs were 60.51 and 84.51 in women and men respectively. Most common cancers in men were skin (ASR = 18.85), stomach (15.02), bladder (ASR = 11.25), prostate (ASR = 8.93) and colorectal (ASR = 8.29). Most common cancers in women were breast (ASR = 18.24), skin (ASR = 12.01), colorectal (ASR = 7.75), stomach (ASR = 7.05) and haematocyte (ASR = 4.01).

CONCLUSION

A significant increase was observed in the incidence of cancers in the country. Therefore, it is necessary to perform screening, early diagnosis and treatment in early stages of cancers.

Comparison of the effects of intra-articular sole ropivacaine and combined ketorolac and ropivacaine for pain control after knee arthroscopy surgery

INTRODUCTION

Effective pain relief is important after arthroscopic knee surgery to permit initiation of daily activities of life. This study is performed in order to investigate the effect of multi-model therapy for pain control after surgery. This clinical, randomized and double-blind trial is conducted on patients who get knee arthroscopy surgery.

METHODS

Of these patients, 40 were divided into two groups by Block Randomization method: 1 - sole ropivacaine group (150 mg); 2 - combined ketorolac (30 mg); and ropivacain (150 mg) group. These drugs were injected intra-articularly at the end of knee arthroscopic surgery. The first consequence including measurement of pain severity after entrance to recovery room and 2, 4, 8, 12, 18 and 24 hours after surgery were evaluated according to the visual analogue pain score. The second consequence, including nausea, vomiting and sedation, was assessed by expert nurses in the recovery room and surgery part according to nausea and vomiting scale and Ramsay sedation scale, respectively.

RESULTS

All groups had excellent analgesia at 0 and 4 hours, postoperatively. Group-combined ketorolac and ropivacaine had significantly lower visual analogue pain score as well as higher sedative scale at 8, 12, 18 and 24 hours after surgery at rest and during movement compared with the other group (p < 0.05). Moreover, there was no statistical difference between groups in regard of nausea and vomiting.

CONCLUSION

Addition of ketolorac to ropivacaine intra-articularly in arthroscopic knee surgery enhances analgesic efficacy of local anaesthetics and cause more sedation after surgery.

Priorities of continuing training for global practitioners in Kashan University of Medical Sciences 2013

Introduction: Continuing the medical education has already been a concern, as a universal principle and necessity in the universe, so that the World Health Organization (WHO) has specified it as an urgent necessity. This research objective was the assay of priorities of continuing training for global practitioners at Kashan University of Medical Sciences. Methods and Materials: In this cross-sectional study, 212 out of 600 general practitioners take parting in the keeping on the medical education programmes held by KUMS were covered. After being interviewed about their needs and interest in the programmers, a survey including demographic information such as the education needed, way of teaching, etc., was given to them. The data were then analyzed by SPSS v 11.5. Results: 137 (64.6%) cases were males and 75 (48.3%) were women. Also, 38 (17.9%) individuals were working in emergency wards. Findings indicated that the first priority of the programs was the internal diseases emergency, and then the pediatric common diseases. The third priority was the infectious common diseases. Conclusions: The needs of the CME and the use of the appropriate methods to match the content of the training needed the assessment of the GP training program design painting by the learners, thus enhancing quality and the efficiency of CME applications.

Altered white-matter architecture in treatment-naive adolescents with clinical depression

BACKGROUND

Depressive disorders are highly prevalent in adolescence and confer a heightened risk of recurrence in adulthood. Insight into the developmental neurocircuitry of depression could advance our understanding of depression and aid the development of effective treatment strategies. Whereas white-matter (WM) abnormalities are strongly implicated in adult depression, we still lack a firm understanding of WM architecture in adolescent depression. Using diffusion tensor imaging (DTI), we set out to investigate WM microstructure in a sample of clinically depressed adolescents relative to matched controls.

METHOD

We employed tract-based spatial statistics (TBSS) to examine WM microstructure in 25 treatment-naive adolescents with clinical depression relative to 21 matched controls. Using TBSS, we examined fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD). Threshold-free cluster enhancement (TFCE) with family-wise error (FWE) correction was used to control for multiple comparisons.

RESULTS

Our analysis revealed abnormal WM microstructure in clinically depressed adolescents. More specifically, whole-brain analysis revealed that patients had lower FA values in the body of the corpus callosum (CC), coupled with elevated RD and MD, and preserved AD. Conversely, region-of-interest analysis revealed that patients had higher FA values in the uncinate fasciculus (UF), coupled with elevated AD, reduced RD and preserved MD.

CONCLUSIONS

In line with neurocircuitry models of depression, our findings suggest that WM abnormalities within pathways facilitating cognitive and emotional functioning are involved in the pathophysiology of depression. Importantly, our findings show that these WM abnormalities are already present early in the course of the disorder.

Effects of dominant/subordinate social status on formalin-induced pain and changes in serum proinflammatory cytokine concentrations in mice

Current investigations regarding social stress primarily focus on the health consequences of being in stressful social hierarchies. The repetitive nature of social conflicts seems to favor an induction of hyperalgesia or hypoalgesia, both in rodents and humans. Additionally, social conflicts may affect the immune system. In order to better establish the pain and immune responses to stress, the present study implemented a sensory contact model on 32 male BALB/c mice. Subsequent to establishing a dominance/submissive social relationship, each mouse was injected with formalin (20 μl, 2%) and their pain behavior was scored and serum concentrations of proinflammatory cytokines IL-1 and IL-6, and corticosterone were also measured. Test results revealed that subordinate mice were hypoalgesic during chronic phase of formalin test compared to control and dominant mice (P<0.05). On the other hand, subordinate mice were hyperalgesic compared to dominant mice during the whole acute phase of formalin test (P<0.05). Corticosterone, IL-1 and IL-6 concentrations were much higher in serum of dominant and subordinate mice than in the control group (p<0.05). The results indicated that, although both dominant and subordinate animals displayed an increase in serum corticosterone and proinflammatory cytokines during social interactions, their response to pain perception differently was affected with the social status.

The effect of social stress on chronic pain perception in female and male mice

The current investigations on social stress primarily point to the negative health consequences of being in a stressful social hierarchy. The repetitive nature of such stressors seems to affect behavioral response to pain both in rodents and humans. Moreover, a large discrepancy in the possibility of social stresses affecting pain perception in the two genders exists. The present study examined the effect of chronic social stress on nociceptive responses of both sexes by implementing of food deprivation, food intake inequality and unstable social status (cage-mate change every 3 days) for a period of 14 days in 96 Balb/c mice. In this regard we injected 20 µl formalin 2% into the plantar surface of hind paw at the end of stress period and scored pain behaviors of all subjects, then serum concentrations of proinflammatory cytokines were measured. Our results showed that there was significant difference in chronic phase of formalin test following implementation of food deprivation and inequality (P<0.05) as compared to control group, so that pain perception was decreased considerably and this decline in inequality exposed subjects was well above isolated ones (P<0.05); whereas unstable social situation did not affect pain perception. Moreover, IL-1 and IL-6 concentrations in serum of stressed mice of both genders were well above control group (p<0.05). Finally, despite chronic pain perception in control and unstable male subjects was larger than females; the decrease of chronic pain perception in male stressed animals (poverty and inequality experienced subjects) was much more than stressed females. These results revealed that although food deprivation and social inequality can induce hypoalgesia, some socioeconomic situations like social instability don't affect pain sensation, whereas there were similar increases of proinflammatory cytokines level in all socially stressed subjects. In addition, males display larger hypoalgesic responses to inequality as compared with females.

Relation of assertiveness and anxiety among Iranian University students

ACCESSIBLE SUMMARY

• The findings from the present study revealed that less than 30% of nursing and midwifery students have high assertiveness and only half of them have low anxiety. • Assertiveness and anxiety have negative correlations in nursing and midwifery students and affect the mental health and educational and occupational performance of the students. • Many factors such as years of education and working while studying influence the level of assertiveness in the students. • The anxiety in students had a significant relation with the father's level of education, family income, etc.

ABSTRACT

The simultaneous existence of low assertiveness and high anxiety in nursing and midwifery students leads to the disruption of study performance. There exists little information concerning their assertiveness. The purpose of this study was to determine the relation of assertiveness and anxiety in nursing and midwifery students. In this correlational, cross-sectional study, 173 nursing students (68 males and 105 females) and 77 midwifery students were recruited from the Tehran University of Medical Sciences in Iran. Data were collected using a questionnaire including personal-social factors, the Spielberger Trait Anxiety Inventory and the Assertion Inventory of Gambrill and Richey. More than half of the nursing and midwifery students (59.5% and 59.7%, respectively) had moderate assertiveness. Also, 43.3% and 36.4% of them had moderate and high levels of anxiety. Pearson correlation test revealed that assertiveness and anxiety had negative correlations in nursing (r=-0.51, P < 0.001) and midwifery (r=-0.449, P < 0.001) students. Some demographic variables had significant correlations with assertiveness and anxiety among the students. Considering the relation of assertiveness and anxiety and its effects on mental health and educational and occupational performance, students should be informed of the required skills for positive interaction with others and to increase assertiveness and decrease anxiety.