Local anaesthesia for surgical extraction of mandibular third molars: a systematic review and network meta-analysis

Clinical Oral Investigations - Pain management for the extraction of the mandibular third molar is a challenge as compelling evidence in comparative anaesthetics is currently lacking. Thorough...     

Role of anti-allergic agents on attenuating transfusion reactions in adults: A systematic review and meta-analysis

BackgroundAnti-allergic agents (e.g. dexamethasone, chlorpheniramine or promethazine) are commonly administered to patients prior to blood product transfusions. However, the use of these agents is largely experience-based instead of evidence-based. This meta-analysis aimed to explore the evidence behind using anti-allergic agents to attenuate transfusion reactions.Materials and MethodsThe Pubmed, EMBASE, Cochrane Library, Wanfang, Chinese National Knowledge Infrastructure (CNKI), and Chinese Biomedical literature (CMB) databases were all queried for related articles. Data from groups treated with and without anti-allergic agents were collected for meta-analysis using RevMan 5.3. Baseline characteristics and univariate statistics between groups were compared using SPSS 19.0.ResultsEight eligible articles (six case control studies and two randomized controlled trials, all with high risks of bias) were identified (22060 total cases). Administered anti-allergic agents in these studies only included dexamethasone, chlorpheniramine or promethazine. Baseline characteristics showed no significant age or gender differences between treatment or control groups. There were no significant differences between the pooled experimental or control groups (for each of the three medications) in terms of fever, pruritis, rash, airway spasm or overall transfusion reaction rates.ConclusionThere is no evidence that dexamethasone, chlorpheniramine or promethazine can prevent transfusion reactions. Avoiding the arbitrary use of such anti-allergic agents before blood transfusions may potentially avoid needless adverse drug reactions.     

A Standardized Framework for Fluorescence-Guided Margin Assessment for Head and Neck Cancer Using a Tumor Acidosis Sensitive Optical Imaging Agent

Molecular Imaging and Biology - Intra-operative management of the surgical margin in patients diagnosed with head and neck squamous cell carcinoma (HNSCC) remains challenging as surgeons still have...     

Effect of specific surface area on syngas production performance of pure ceria in high-temperature thermochemical redox cycling coupled to methane partial oxidation

Specific surface area is a key parameter determining the rates of thermochemical redox reactions in metal oxides. We have experimentally investigated the effect of specific surface area on syngas production of pure ceria powders under two experiments such as a heating experiment without syngas production and an isothermal thermochemical redox cycling experiment using carbon dioxide splitting and methane partial oxidation. The specific surface area of ceria powders decreased relatively slowly during 50 hours of ceria powder heating without syngas production due to a combination of oriented attachment and grain-boundary diffusion. When cycled thermochemically, the specific surface area of ceria powders rapidly decreased only in the initial 10 minutes of reduction in the 1st cycle due to evaporation and condensation. A significant decrease of specific surface area during the initial stage of thermochemical ceria powder cycling is unavoidable even if temperatures as low as T = 1173 K are used in the reduction reaction coupled to methane partial oxidation.

Specific surface area is a key parameter determining the rates of thermochemical redox reactions in metal oxides.     

Controllable stripping of radiolabeled group in vivo to optimize nuclear imaging via NO-responsive bioorthogonal cleavage reaction

A novel “turn-off” strategy for controllable radionuclide clearance is established. 1,4-dihydropyridine (DHP) is used as a conditional linker to connect a radioisotope labeled moiety and nano-agent. A highly specific, sensitive and effective C–C bond cleavage of DHP happens in vivo when treated with nitric oxide which is provided by glyceryl trinitrate (GTN). The radioactive cut-off part from the nanoparticle is observed to be cleared quickly by microSPECT-CT. 3–5 times decreases of radioactivity in the blood, kidneys, intestine, heart and lungs are observed after GTN treatment in a biodistribution assay. The radioactivity redistribution indicates that the radioactive leaving part is indeed cut off and the radionuclide metabolism accelerated. Organ level internal dose assessment reveals the GTN treated groups carry only ½ the radiation dose of the control group. Collectively, a feasible pathway for controllable radionuclide clearance is for the first time provided for high contrast and low radiation nuclear imaging.

A novel “turn-off” strategy was developed for controllable radionuclide clearance in organisms.

Radiolabeled compounds with biological activity, or radiotracers, have been widely used for nuclear imaging and radiation therapy. Compared with other imaging modalities, a unique problem in radiotracer-based imaging is that the radioactivity cannot be simply “turned off”. As a result, it is impossible to carry out multi-scans of the same organ with different tracers in a short period. For instance, there are three kinds of marker receptors (ER, PR, HER2) expressed in breast cancer. Different type of breast cancer expresses a different combination of these three. Therefore, three kinds of radiotracers that aim to bind the corresponding receptors will be used to distinguish individual breast cancer phenotype. The uptake of a second tracer can''t be quantified accurately before the radioactivity of the first tracer decayed to background level, which may need one or two days depending on the half-life of radionuclide. So, it''s necessary to develop a strategy to “quench” the radioactivity. Furthermore, nonspecific binding is inevitable, and the “noise” or “background” from non-specific binding of radiotracers to non-target proteins cannot be easily differentiated from the specific binding component.Therefore, it''s meaningful to develop a kind of reaction that could strip the radiation by control. To achieve this goal, the metabolism of the radioactive part should be accelerated. The biorthogonal cleavage reaction would perfectly meet the needs, if (1) cleavable reactions could happen by the control in vivo; (2) the cut-off part has a relatively fast metabolism; (3) radionuclide is linked on the cut-off part.¹ One of the key issues that bio-orthogonal reactions resolve is to bind two components into one, and make the different metabolic rate of different components synchronized.² As the reaction in the opposite direction of bio-orthogonal reaction, the bio-orthogonal cleavage reaction can extinguish the radiation by diversifying the metabolism of radionuclides and the slow metabolic targeting components.Dihydropyridine (DHP) and its cleavage-triggering partner nitric oxide (NO) can perfectly meet the three conditions. NO, a hydrophobic signal molecule, could spread without any transmembrane transporter, which means NO could spread quickly and spend little energy.^3–5 Many kinds of NO donor drugs are commercially available, such as glyceryl trinitrate (GTN), sodium nitroprusside, etc. In our previous work,⁶ it was demonstrated that the physiological concentration of NO is high enough to cleave the C–C bond of DHP. Furthermore, NO donor drugs could offer a circumstance with higher NO concentration than normal physiological concentration. Therefore, it is possible for the reaction between DHP and NO from donor drugs to occur in vivo. Herein, a NO-triggerred “turn-off” system to extinguish the radiation by cleaving the radionuclides from nanoparticles is present. Benzyl group substituted 1,4-dihydropyridine can be cleaved through controlled NO stimulation by intraperitoneal injection of GTN.Nanoparticles as the major kind of theranostic agents have been developed quickly over these years.^7–11 During the process of synthesis, nanoparticles with similar shape, scale and dispersion properties would be obtained by manipulating conditions precisely. Therefore, the metabolism of nanoparticles in the living body is more predictable than diverse small molecules. Especially, radionuclides labeled nanoparticles not only play roles in diagnosis but also work well on tumor therapy. Enhanced permeability and retention (EPR) effect make nanoparticles wonderful radiotherapy reagents.^12–15 However, nanoparticles mean to be easily captured by the mononuclear phagocyte system (MPS), which makes the nanoparticles mostly enriched in liver besides in tumor.^16–20 Furthermore, metabolism of nanoparticles are quite slow than most of the small molecules, which means the radionuclides labeled on nanoparticles have similar slow metabolism to their carriers. Unnecessarily loaded radiation from the nanoparticles will also harm normal liver cells where the nanoparticles accumulate heavily.     

Drug treatment of chronic subdural hematoma

ABSTRACT

Introduction: Chronic subdural hematoma (CSDH) is a common neurosurgical disease, whose incidence has been steadily increasing with our aging population. While not common, CSDH can also occur in children. CSDH is often associated with traumatic head injury, but its underlying mechanism remains poorly understood. The first line treatment for CSDH is surgery. However, surgery is contraindicated in some patients and has a high rate of recurrence. Effective non-surgical treatment is therefore highly desirable.

Areas covered: This review discusses the pathogenesis of CSDH and drugs that have been used to treat CSDH either as monotherapy or an adjuvant to surgery, including controlled clinical trials.

Expert opinion: The pathophysiology of CSDH remains poorly understood. Developing effective drug treatments is therefore challenging. Most drugs discussed in this review are evaluated in small clinical studies without sufficient sample size and controls for confounding variables. More controlled clinical trials are therefore needed to carefully evaluate drugs for the non-surgical treatment of CSDH, especially for drugs targeting specific pathogenic pathways of CSDH.