Recent developments in the synthesis of regioregular thiophene-based conjugated polymers for electronic and optoelectronic applications using nickel and palladium-based catalytic systems

Thiophene-based conjugated polymers hold an irreplaceable position among the continuously growing plethora of conjugated polymers due to their exceptional optical and conductive properties, which has made them a centre of attention for the past few decades and many researchers have contributed tremendously by designing novel strategies to reach more efficient materials for electronic applications. This review aims to highlight the recent (2012–2019) findings in design and synthesis of novel thiophene-based conjugated polymers for optical and electronic devices using organometallic polycondensation strategies. Nickel- and palladium-based protocols are the main focus of this account. Among them nickel-catalyzed Kumada catalyst-transfer polycondensation, nickel-catalyzed deprotonative cross-coupling polycondensation, palladium-catalyzed Suzuki–Miyaura and Migita–Kosugi–Stille couplings are the most popular strategies known so far for the synthesis of functionalized regioregular polythiophenes exhibiting fascinating properties such as electronic, optoelectronic, chemosensitivity, liquid crystallinity and high conductivity. This account also presents a brief overview of direct arylation polymerization (DArP) protocol that has shown a great potential to lessen the drawbacks of conventional polymerization techniques. DArP is a cost-effective and green method as it circumvents the need for the synthesis of arylene diboronic acid/diboronic ester and distannyl arylenes using toxic precursors. DArP also puts off the need to preactivate the C–H bonds, hence, presenting a facile route to synthesize polymers with controlled molecular weight, low polydispersity index, high regioregularity and tunable optoelectronic properties using palladium-based catalytic systems.

Thiophene-based conjugated polymers are important conjugated polymers due to their exceptional optical and conductive properties, over the past few decades many researchers have designed novel strategies to reach more efficient materials for electronic applications.     

Effects of pirfenidone on experimental head injury in rats

Traumatic brain injury (TBI) continues to be a significant public healthcare concern. Neuroinflammation that occurs in the secondary phase of TBI leads to cognitive and physical dysfunction. A number of therapeutic modalities have been evaluated in an attempt to find a suitable treatment. The only drug approved for the treatment of idiopathic pulmonary fibrosis, pirfenidone, has been evaluated for its antifibrotic, anti-inflammatory, and anti-oxidant properties for various disorders, but this is the first study to examine its effects in an experimental TBI model. Twenty-four Wistar rats were randomly divided into three groups: control, trauma, and pirfenidone. The two latter groups underwent experimental diffuse cortical injury mimicking TBI. Neurological assessment was performed using the Garcia test, histological analysis was performed to examine neuroprotective and anti-inflammatory effects, and biochemical analyses of neuron-specific enolase (NSE), S-100B, caspase-3, and thiobarbituric acid reactive substances were performed. The pirfenidone group had a better Garcia test score (P=0.001), an increased anti-inflammatory effect (P<0.001), and an enhanced neuroprotective effect (P=0.007) along with decreased NSE, S100B, and TBARS levels compared to the trauma group. However, pirfenidone did not show a beneficial effect on caspase-3 levels. Pirfenidone may help decrease mortality and morbidity rates after TBI through its anti-inflammatory and antioxidant effects.     

The neutralization effect of montelukast on SARS-CoV-2 is shown by multiscale in silico simulations and combined in vitro studies

Small molecule inhibitors have previously been investigated in different studies as possible therapeutics in the treatment of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In the current drug repurposing study, we identified the leukotriene (D4) receptor antagonist montelukast as a novel agent that simultaneously targets two important drug targets of SARS-CoV-2. We initially demonstrated the dual inhibition profile of montelukast through multiscale molecular modeling studies. Next, we characterized its effect on both targets by different in vitro experiments including the enzyme (main protease) inhibition-based assay, surface plasmon resonance (SPR) spectroscopy, pseudovirus neutralization on HEK293T/hACE2+TMPRSS2, and virus neutralization assay using xCELLigence MP real-time cell analyzer. Our integrated in silico and in vitro results confirmed the dual potential effect of montelukast both on the main protease enzyme inhibition and virus entry into the host cell (spike/ACE2). The virus neutralization assay results showed that SARS-CoV-2 virus activity was delayed with montelukast for 20 h on the infected cells. The rapid use of new small molecules in the pandemic is very important today. Montelukast, whose pharmacokinetic and pharmacodynamic properties are very well characterized and has been widely used in the treatment of asthma since 1998, should urgently be completed in clinical phase studies and, if its effect is proved in clinical phase studies, it should be used against coronavirus disease 2019 (COVID-19).     

Enthesopathy in patients with familial Mediterranean fever: increased prevalence in M694 V variant

Enthesopathy is pathology of bony insertions of tendons, ligaments or joint capsules. It is a frequent finding in rheumatic diseases, like ankylosing spondylitis (AS) and Behçet’s disease. Musculoskeletal complaints are common in patients with familial Mediterranean fever (FMF), and these could be a clinical manifestation of enthesopathy. Hence, we investigated the possible association between FMF and enthesopathy. Fifty-six patients with FMF and 11 patients with FMF-associated spondyloarthropathy (FMFS) were enrolled. Forty-seven healthy individuals and 36 patients with AS formed the healthy and diseased control groups. Musculoskeletal complaints were meticulously questioned, and all patients underwent a detailed physical and ultrasonographic (US) examination of the lower limbs. US scorings of enthesopathy was performed according to the Glasgow Ultrasound Enthesitis Scoring System (GUESS). Demographic data, disease characteristics, MEFV genotypes and HLA B27 results were retrieved from the medical records. Patient-reported pain and physical examination findings consistent with enthesopathy were frequent in all groups with the highest prevalence in the FMFS group. Heel was the most common region affected in all patient groups. FMF patients harboring M694 V variant had higher GUESS scores compared to patients with other variants (2.78 ± 2.43 vs. 1.37 ± 1.67, p = 0.026). There was no statistically significant difference in the mean ± SD GUESS scores between healthy subjects and those FMF patients with genetic variants other than M694 V (1.38 ± 1.42 vs. 1.37 ± 1.67, p > 0.05). Enthesopathy may not be a feature of general FMF population; rather, it might be specifically associated with the presence of M694 V variant. Our results further support the previous evidence regarding M694 V mutation and spondyloarthropathy association.     

Periodontal Treatment Is Associated With Improvement in Gastric Helicobacter pylori Eradication: An Updated Meta-analysis of Clinical Trials

ObjectivesThe efficacy of conventional systemic antibiotic therapy for eradication of Helicobacter pylori has been seriously challenged by antibiotic resistance. Identification of alternative therapeutic strategies might help to overcome this limitation. The aim of this study was to update previous meta-analyses that investigated the effect of periodontal treatment on gastric H. pylori eradication.MethodsA systematic electronic search of the literature was conducted to identify all published clinical trials that compared the effect of adjunct periodontal treatment on conventional systemic H. pylori eradication therapy.ResultsThe updated analysis (consisting of 541 participants representing six studies) demonstrated that, compared with conventional systemic eradication therapy alone, the addition of periodontal treatment resulted in improvements in gastric H. pylori eradication rates with OR 4.11 (P = 0.01). Moreover, not to lose any data, the previously presented Chinese results that could not be assessed by any available mechanism deduced from previously published meta-analysis and with other records were re-analysed. Similarly, the second meta-analysis adding up to a final cluster of 10 studies (909 participants) gives further credence to periodontal treatment as a useful concomitant therapy in the H. pylori eradication therapy (odds ratio [OR] = 2.65; P = 0.0002). Finally, the meta-analysis of four trials consisting of 177 cases and 161 controls showed that periodontal treatment also improved non-recurrence rates of gastric H. pylori infection, with an OR of 5.36 (P-value = 0.0002).ConclusionAlthough the inclusion of five additional clinical trials in this updated meta-analysis has not changed the result of the previous review, the current meta-analysis is superior for having removed one study involving the use of chlorhexidine, which did not meet appropriate criteria for inclusion. Our results strengthen the value of periodontal treatment as an adjunctive remedy. Consistency of these results suggests that the incorporation of professional periodontal treatment with systemic eradication therapy may be a wise strategy, enhancing the efficacy of H. pylori eradication therapy. Systematic review registration: in PROSPERO ID number: CRD42019119347.     

Pulmonary cement embolism: a complication of percutaneous vertebroplasty

Background: Percutaneous vertebroplasty (PV) has recently become a very common procedure for vertebral compression fractures. Extravasation of cement, a common event associated with vertebroplasty, may lead to cement emboli in the lungs.

Purpose: To determine the frequency of pulmonary cement embolism after percutaneous vertebroplasty.

Material and Methods: Between 2002 and 2006, 128 percutaneous vertebroplasties were performed in 73 patients (56 women and 17 men) in our institution. Postprocedural chest radiographs were obtained for all patients and assessed for the presence of pulmonary cement emboli.

Results: Pulmonary cement embolism was detected on chest radiographs and confirmed with chest computed tomography (CT) in four patients treated with percutaneous vertebroplasty for osteoporotic collapse and one patient treated for multiple myeloma. The imaging finding of pulmonary cement embolism was solitary or multiple fine radiodense lines with occasional branching patterns. The frequency of pulmonary cement embolism was 6.8%.

Conclusion: An incidence of pulmonary cement embolism of 6.8% during PV was found. Close clinical follow-up, postprocedural chest radiographs, and chest CT scans, if necessary, are important for the detection of pulmonary cement embolism at an early stage.     

The role of posterior instrumentation and fusion after anterior radical debridement and fusion in the surgical treatment of spinal tuberculosis: experience of 127 cases

Long periods of immobilization, progressive kyphosis and graft failure are the major postoperative problems encountered after anterior radical surgical treatment for tuberculosis of the spine. Posterior fusion and instrumentation can be an effective solution for these problems. Effectiveness of posterior fusion and instrumentation was investigated in this study on the basis of the cases with anterior procedure only, and with combined anterior-posterior procedures. One hundred twenty-seven cases of tuberculosis of the spine were surgically treated between 1987 and 1995. All had either 1 or more of conditions such as spinal cord compression and neurological deficit, vertebral body collapse and kyphosis, or wide paravertebral abscess unresponsive to medical treatment. Of these, 57 had only anterior radical procedure between the years 1987 and 1993. Seventy cases had posterior instrumentation and fusion after the anterior procedure between the years 1991 and 1995. In about two third of the patients (81) autogenous iliac strut graft and in one third of them (40) autogenous fibular strut graft (cases with more than 2 level involvement) was used along with rib grafts after debridement. Twenty-one of the 57 patients who had only anterior procedure demonstrated a postoperative increase of kyphosis of more than 10 degrees. Increased kyphosis was due to graft slippage in 3, resorption in 2 and subsidence in 16 patients. No such increase or graft failure was noted in cases of combined anterior-posterior procedure. The difference in terms of kyphosis was found to be statistically significant (P=0.047). Anterior radical debridement and strut graft is the golden standard in the surgical treatment of spinal tuberculosis, but it should always be accompanied by posterior instrumentation and fusion to shorten the immobilization period and hospital stay, obtain good and long lasting correction of kyphosis, and prevent further collapse and graft failure.