Influence of systematically varied nano-scale topography on cell morphology and adhesion

The types of cell-matrix adhesions and the signals they transduce strongly affect the cell-phenotype. We hypothesized that cells sense and respond to the three-dimensionality of their environment, which could be modulated by nano-structures on silicon surfaces. Human foreskin fibroblasts were cultured on nano-structures with different patterns (nano-post and nano-grate) and heights for 3 days. The presence of integrin alpha(5), beta(1), beta(3), paxillin and phosphorylated FAK (pFAK) were detected by western blot and immunofluorescence. Integrin beta(3) exhibited stronger signals on nano-grates. pFAK and paxillin were observed as small dot-like patterns on the cell-periphery on nano-posts and as elongated and aligned patterns on nano-grates. Collectively, our observations highlighted the presence of focal (integrin beta(1), beta(3), pFAK, paxillin), fibrillar (integrin alpha(5), beta(1)) and 3-D matrix (integrin alpha(5), beta(1), paxillin) adhesions on nano-structures. The presented nano-structures offer interesting opportunities to study the interaction of cells with topographical features comparable to the size of extracellular matrix components.     

Understanding the expanding role of primary care physicians (PCPs) to primary psychiatric care physicians (PPCPs): enhancing the assessment and treatment of psychiatric conditions

Aim In the current healthcare system primary care physicians (PCPs) have, in effect, become the primary psychiatric care physicians (PPCPs) for many of their patients. Being the PPCP in an already busy and stressful medical industry presents additional time management and treatment challenges to successfully manage patients' medical and psychiatric needs. The aim of the study was to ascertain PCPs' psychiatric assessment and treatment practices and to determine the extent to which PCPs have a need for using a structured psychiatric assessment tool.Method We sent 300 PCPs a survey to examine their psychiatric assessment and treatment practices. A one-page questionnaire was used to inquire about PCPs' psychiatric care practice habits including types of conditions treated, psychiatric medications prescribed, assessment methods used, interest in using a structured assessment tool and referral sources used. Sixty-eight usable surveys (23%) were returned.Results PCPs identify approximately one-third of their patients as mental health patients. They are treating a wide range of psychiatric conditions and prescribing a variety of psychiatric medications. The vast majority are using traditional clinical interviewing as their primary method of psychiatric assessment. However, the majority were willing to use a structured psychiatric assessment tool.Conclusion PCPs are serving a useful role in providing psychiatric treatment to many of their patients. Using a more structured psychiatric assessment method in practice could ultimately strengthen the assessment and treatment of psychiatric conditions in primary care settings.     

The enhanced expression of heat stress-related genes in scleractinian coral ‘Porites harrisoni’ during warm episodes as an intrinsic mechanism for adaptation in ‘the Persian Gulf’

Coral Reefs - Shallow water tropical reefs are widely threatened by anthropogenic ocean warming which sometimes exceeds their thermal tolerance limit. The majority of reefs have been currently...     

Apelin-13 Inhibits Apoptosis of Cortical Neurons Following Brain Ischemic Reperfusion Injury in a Transient Model of Focal Cerebral Ischemia

Stroke is the third leading cause of death world-wide, affecting 15 million people annually. Diminished blood supply to the brain cells is the main cause of damage following stroke. When focal ischemia occurs, the core of brain tissue influenced by reduced blood supply undergoes necrotic cell death. The adipocytokine Apelin is a peptide that was isolated from a bovine stomach for the first time. This peptide and its receptor are abundantly expressed in the nervous and cardiovascular systems. According to previous studies, Apelin-13 protects cardiomyocytes from ischemic injury and apoptosis. In addition, this peptide has neuroprotective effect on hippocampal and cultured mouse cortical neurons against NMDA receptor-mediated excitotoxicity as well as cortical neurons from ischemic injury. The present study was conducted to determine whether Apelin-13 inhibits apoptosis in the ischemic penumbra in transient focal cerebral ischemia. Focal cerebral ischemia was induced in male Wistar rats by 60 min middle cerebral artery occlusion (MCAO) using a filament method, followed by 23-h reperfusion. Saline as a vehicle and Apelin-13 at doses of 50 and 100 μg were injected intracerebro-ventriculary (ICV) at the beginning of ischemia. Apoptosis and neurological dysfunction were assessed 24-h after MCAO. Our results indicated that administration of Apelin-13 at doses of 50 and 100 μg ICV markedly reduced apoptosis by decreasing positive TUNEL cells (P < 0.001). In addition, Apelin-13 at doses of 100 μg significantly change neurological dysfunction (P < 0.05). Our findings demonstrate that treatment by Apelin-13 exerts its protective effects in ischemic models via blocking programmed cell-death. We suggest that Apelin-13 might be a promising therapeutic target for stroke, although more researches are necessary to take into account the potential therapeutic effects of Apelin-13 in stroke patients.     

Stress tolerance in flax plants inoculated with Bacillus and Azotobacter species under deficit irrigation

Drought stress affects not only crop growth but also its morpho-physiological and biochemical traits to reduce crop productivity. The study reported in this article was designed and implemented to determine the effects of deficit irrigation and bacterial inoculation on flax plants. For this purpose, seeds were inoculated with Bacillus amyloliquefaciens (B₁), Bacillus sp. Strain1 (B₂), and Azotobacter chroococcum (A) as plant growth promoting rhizobacteria (PGPR). The individual inoculated plants were then grown under field conditions in 2015, while individually and in combination in pots in 2016. The irrigation regimes in either experiments included 50, 75 and 100% crop water requirement. Bacterial cultures were observed to produce ammonia (except B₂), indole acetic acid and siderophores. Results showed that the PGPRs significantly mitigated the effects of water deficit. Compared with the control plants, the bacterially-inoculated plants had an enhanced relative water content, plant height, water-soluble carbohydrate and proline contents and antioxidant enzyme activities, but a decreased malondialdehyde content. B₁ exhibited greater effects on most of the traits investigated under the field conditions rather than those with moderate and severe drought stress, while application of the triple bacteria in pots had greater effects on relative water content, carbohydrate and proline contents as well as malondialdehyde. The significant differences in abiotic stress indicators in PGPR-treated plants suggest that these bacteria could be used as biofertilizers to assist plant growth and to reduce the adverse effects of deficit irrigation.     

Impaired striatal Akt signaling disrupts dopamine homeostasis and increases feeding

Background

The prevalence of obesity has increased dramatically worldwide. The obesity epidemic begs for novel concepts and therapeutic targets that cohesively address “food-abuse” disorders. We demonstrate a molecular link between impairment of a central kinase (Akt) involved in insulin signaling induced by exposure to a high-fat (HF) diet and dysregulation of higher order circuitry involved in feeding. Dopamine (DA) rich brain structures, such as striatum, provide motivation stimuli for feeding. In these central circuitries, DA dysfunction is posited to contribute to obesity pathogenesis. We identified a mechanistic link between metabolic dysregulation and the maladaptive behaviors that potentiate weight gain. Insulin, a hormone in the periphery, also acts centrally to regulate both homeostatic and reward-based HF feeding. It regulates DA homeostasis, in part, by controlling a key element in DA clearance, the DA transporter (DAT). Upon HF feeding, nigro-striatal neurons rapidly develop insulin signaling deficiencies, causing increased HF calorie intake.

Methodology/Principal Findings

We show that consumption of fat-rich food impairs striatal activation of the insulin-activated signaling kinase, Akt. HF-induced Akt impairment, in turn, reduces DAT cell surface expression and function, thereby decreasing DA homeostasis and amphetamine (AMPH)-induced DA efflux. In addition, HF-mediated dysregulation of Akt signaling impairs DA-related behaviors such as (AMPH)-induced locomotion and increased caloric intake. We restored nigro-striatal Akt phosphorylation using recombinant viral vector expression technology. We observed a rescue of DAT expression in HF fed rats, which was associated with a return of locomotor responses to AMPH and normalization of HF diet-induced hyperphagia.

Conclusions/Significance

Acquired disruption of brain insulin action may confer risk for and/or underlie “food-abuse” disorders and the recalcitrance of obesity. This molecular model, thus, explains how even short-term exposure to “the fast food lifestyle” creates a cycle of disordered eating that cements pathological changes in DA signaling leading to weight gain and obesity.     

Development of optical biosensor technologies for cardiac troponin recognition

Acute myocardial infarction (AMI) is the leading cause of death among cardiovascular diseases. Among the numerous attempts to develop coronary marker concepts into clinical strategies, cardiac troponin is known as a specific marker for coronary events. The cardiac troponin concentration level in blood has been shown to rise rapidly for 4–10 days after onset of AMI, making it an attractive approach for a long diagnosis window for detection. The extremely low clinical sensing range of cardiac troponin levels consequently makes the methods of detection highly sensitive. In this review, by taking into consideration optical methods applied for cardiac troponin detection, we discuss the most commonly used methods of optical immunosensing and provide an overview of the various diagnostic cardiac troponin immunosensors that have been employed for determination of cardiac troponin over the last several years.     

The fate of Amazonian ecosystems over the coming century arising from changes in climate,atmospheric CO2, and land use

There is considerable interest in understanding the fate of the Amazon over the coming century in the face of climate change, rising atmospheric CO₂ levels, ongoing land transformation, and changing fire regimes within the region. In this analysis, we explore the fate of Amazonian ecosystems under the combined impact of these four environmental forcings using three terrestrial biosphere models (ED2, IBIS, and JULES) forced by three bias‐corrected IPCC AR4 climate projections (PCM1, CCSM3, and HadCM3) under two land‐use change scenarios. We assess the relative roles of climate change, CO₂ fertilization, land‐use change, and fire in driving the projected changes in Amazonian biomass and forest extent. Our results indicate that the impacts of climate change are primarily determined by the direction and severity of projected changes in regional precipitation: under the driest climate projection, climate change alone is predicted to reduce Amazonian forest cover by an average of 14%. However, the models predict that CO₂ fertilization will enhance vegetation productivity and alleviate climate‐induced increases in plant water stress, and, as a result, sustain high biomass forests, even under the driest climate scenario. Land‐use change and climate‐driven changes in fire frequency are predicted to cause additional aboveground biomass loss and reductions in forest extent. The relative impact of land use and fire dynamics compared to climate and CO₂ impacts varies considerably, depending on both the climate and land‐use scenario, and on the terrestrial biosphere model used, highlighting the importance of improved quantitative understanding of all four factors – climate change, CO₂ fertilization effects, fire, and land use – to the fate of the Amazon over the coming century.