Comparison of Tc-99m MAA Planar Versus SPECT/CT Imaging for Lung Shunt Fraction Evaluation Prior to Y-90 Radioembolization: Are We Overestimating Lung Shunt Fraction?

CardioVascular and Interventional Radiology - To compare lung shunt fraction (LSF) prior to Y-90 radioembolization calculated using planar imaging versus SPECT/CT in patients with hepatocellular...     

Meta-analysis of Intraprocedural Comparative Effectiveness of Vascular Plugs Vs Coils in Proximal Splenic Artery Embolization and Associated Patient Radiation Exposure

PurposeTo compare vascular plugs to coil embolization of the proximal splenic artery and evaluate differences in radiation exposure to the patients.MethodsAn electronic literature search was performed for relevant studies from January 2000 to July 2018 that compared the efficacy of vascular plugs vs coils in splenic artery embolization. Only studies that investigated coil or vascular plug use, without combination with other embolic agents, were included. Meta-analysis was performed using a fixed effects model approach with the inverse variance-weighted average method to determine pooled differences in time to vessel occlusion, procedure time, fluoroscopy time, total number of devices used, and radiation exposure. Heterogeneity was assessed using the I square statistic. Pooled outcomes were compared, and quality assessments were evaluated using the Newcastle Ottawa Scale.ResultsEight studies met inclusion criteria. 81 patients were embolized with vascular plugs and 52 patients with coils only. The most common indication for splenic artery embolization was trauma. Time to vessel occlusion was shorter in the vascular plug group by 7.11 minutes (P = 0.003). Fluoroscopy time was shorter by 13.82 minutes in the vascular plug cohort, and these patients received less radiation (?439 mGy) compared to the coil group (P = 0.006 and P = 0.02, respectively). The number of devices was significantly fewer in the vascular plug group (?3.54; P < 0.001). Procedure time was not statistically significant.ConclusionOur data supports the vascular plug is superior to coils for embolization of the proximal splenic artery with respect to occlusion time, fluoroscopy time, patient radiation exposure, and number occlusive devices used.     

Photodynamic inactivation of Streptococcus mutans by curcumin in combination with EDTA

ObjectiveThis study aimed to test the efficacy of photodynamic inactivation (PDI) mediated by curcumin with EDTA against Streptococcus mutans in planktonic suspension using blue LED light.MethodsAntibacterial activity of curcumin and EDTA was evaluated by determination of their minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The fractional inhibitory concentration index (FICI) was used to estimate the synergistic effect of various combination ratios of curcumin and EDTA against S. mutans. Cultures of S. mutans (18 h, 37 °C, 5% C0₂) were prepared to test the effect of curcumin-mediated PDI (50 μM and 500 μM) with or without 0.4% EDTA and 40 s of light-activation with blue light. EDTA and each concentration of curcumin were also tested individually. Chlorhexidine (0.2%), was used as positive control. Planktonic suspensions were also analyzed by viable colony counts (VCC), confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and polymerase chain reaction (PCR).ResultsThe MIC values of curcumin and EDTA were 5 mM and 0.125% respectively. FICI showed a synergistic interaction between curcumin and EDTA. All the combinations with curcumin and blue LED light resulted in a complete inactivation of the S. mutans and CLSM confirms these results, TEM showed morphological changes produced by the PDI. No damage on DNA structure was detected by PCR.SignificanceCurcumin-mediated PDI with EDTA using a blue light, shows a strong inhibitory effect against S. mutans in planktonic culture. Because of the unspecific target mechanism, it could be a promising technique for disinfection of dental tissues.     

In vitro and in vivo evaluation of heparin mediated growth factor release from tissue‐engineered constructs for anterior cruciate ligament reconstruction

Anterior cruciate ligament (ACL) rupture is a common injury often necessitating surgical treatment with graft reconstruction. Due to limitations associated with current graft options, there is interest in a tissue‐engineered substitute for use in ACL regeneration. While they represent an important step in translation to clinical practice, relatively few in vivo studies have been performed to evaluate tissue‐engineered ACL grafts. In the present study, we immobilized heparin onto electrospun polycaprolactone scaffolds as a means of incorporating basic fibroblast growth factor (bFGF) onto the scaffold. In vitro, we demonstrated that human foreskin fibroblasts (HFFs) cultured on bFGF‐coated scaffolds had significantly greater cell proliferation. In vivo, we implanted electrospun polycaprolactone grafts with and without bFGF into athymic rat knees. We analyzed the regenerated ACL using histological methods up to 16 weeks post‐implantation. Hematoxylin and eosin staining demonstrated infiltration of the grafts with cells, and picrosirius red staining demonstrated aligned collagen fibers. At 16 weeks postop, mechanical testing of the grafts demonstrated that the grafts had approximately 30% the maximum load to failure of the native ACL. However, there were no significant differences observed between the graft groups with or without heparin‐immobilized bFGF. While this study demonstrates the potential of a regenerative medicine approach to treatment of ACL rupture, it also demonstrates that in vitro results do not always predict what will occur in vivo. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:229–236, 2015.     

Hyperphosphatemia,Phosphoprotein Phosphatases,and Microparticle Release in Vascular Endothelial Cells

Hyperphosphatemia in patients with advanced CKD is thought to be an important contributor to cardiovascular risk, in part because of endothelial cell (EC) dysfunction induced by inorganic phosphate (Pi). Such patients also have an elevated circulating concentration of procoagulant endothelial microparticles (MPs), leading to a prothrombotic state, which may contribute to acute occlusive events. We hypothesized that hyperphosphatemia leads to MP formation from ECs through an elevation of intracellular Pi concentration, which directly inhibits phosphoprotein phosphatases, triggering a global increase in phosphorylation and cytoskeletal changes. In cultured human ECs (EAhy926), incubation with elevated extracellular Pi (2.5 mM) led to a rise in intracellular Pi concentration within 90 minutes. This was mediated by PiT1/slc20a1 Pi transporters and led to global accumulation of tyrosine- and serine/threonine-phosphorylated proteins, a marked increase in cellular Tropomyosin-3, plasma membrane blebbing, and release of 0.1- to 1-μm-diameter MPs. The effect of Pi was independent of oxidative stress or apoptosis. Similarly, global inhibition of phosphoprotein phosphatases with orthovanadate or fluoride yielded a global protein phosphorylation response and rapid release of MPs. The Pi-induced MPs expressed VE-cadherin and superficial phosphatidylserine, and in a thrombin generation assay, they displayed significantly more procoagulant activity than particles derived from cells incubated in medium with a physiologic level of Pi (1 mM). These data show a mechanism of Pi-induced cellular stress and signaling, which may be widely applicable in mammalian cells, and in ECs, it provides a novel pathologic link between hyperphosphatemia, generation of MPs, and thrombotic risk.     

Soluble α-synuclein–antibody complexes activate the NLRP3 inflammasome in hiPSC-derived microglia

Parkinson’s disease is characterized by accumulation of α-synuclein (αSyn). Release of oligomeric/fibrillar αSyn from damaged neurons may potentiate neuronal death in part via microglial activation. Heretofore, it remained unknown if oligomeric/fibrillar αSyn could activate the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome in human microglia and whether anti-αSyn antibodies could prevent this effect. Here, we show that αSyn activates the NLRP3 inflammasome in human induced pluripotent stem cell (hiPSC)-derived microglia (hiMG) via dual stimulation involving Toll-like receptor 2 (TLR2) engagement and mitochondrial damage. In vitro, hiMG can be activated by mutant (A53T) αSyn secreted from hiPSC-derived A9-dopaminergic neurons. Surprisingly, αSyn–antibody complexes enhanced rather than suppressed inflammasome-mediated interleukin-1β (IL-1β) secretion, indicating these complexes are neuroinflammatory in a human context. A further increase in inflammation was observed with addition of oligomerized amyloid-β peptide (Aβ) and its cognate antibody. In vivo, engraftment of hiMG with αSyn in humanized mouse brain resulted in caspase-1 activation and neurotoxicity, which was exacerbated by αSyn antibody. These findings may have important implications for antibody therapies aimed at depleting misfolded/aggregated proteins from the human brain, as they may paradoxically trigger inflammation in human microglia.

Parkinson’s disease (PD) is characterized by accumulation of α-synuclein (αSyn; encoded by the SNCA gene) (1). Release of oligomeric/fibrillar αSyn from damaged neurons may potentiate neuronal cell death in part via microglial activation (2, 3). Moreover, misfolded proteins in general are thought to interact with brain microglia, triggering microglial activation that contributes to neurodegenerative disorders, although microglial phagocytosis may also initially clear aberrant proteins to afford some degree of protection (2, 4). Additionally, in Alzheimer’s disease (AD), amyloid-β peptide (Aβ) is thought to trigger similar processes in microglia (5–7); however, the mechanism for this trigger is still poorly understood.Microglial cells contribute to neuroinflammation, specifically that mediated by the inflammasome. In particular, the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome has been associated with several neurodegenerative disorders, although other types of inflammation may also be important in this regard (8). The NLRP3 inflammasome is a multiprotein complex that responds to cell stress and pathogenic stimuli to promote activation of caspase-1, which in turn mediates maturation and release of proinflammatory cytokines, including interleukin-1β (IL-1β) and IL-18 (9–11). NLRP3 inflammasome activation is a two-step process, involving an initial priming step and a secondary trigger. Priming involves a proinflammatory stimulus, such as endotoxin, a ligand for Toll-like receptor 4 (TLR4), that increases the abundance of NLRP3 and promotes de novo synthesis of pro–IL-1β via nuclear factor κB (11). The secondary trigger promotes inflammasome complex assembly and caspase-1 activation that in turn mediates the cleavage of pro–IL-1β and subsequent release of mature IL-1β. There are various secondary triggers, including adenosine triphosphate (ATP), microparticles, and bacterial toxins, all of which somehow lead to mitochondrial damage and release of oxidized mitochondrial DNA (11). Neuroinflammation has been reported in both human PD and AD brains (12–15), and NLRP3 inflammasome activation in particular has been observed in mouse models of PD and AD (7, 16). Importantly, in these PD models, dopaminergic (DA) neurons in the substantia nigra are resistant to damage in NLRP3-deficient mice compared with wild-type (WT) mice (16). Interestingly, a recent report identified an NLRP3 polymorphism that confers decreased risk in PD (17). Several groups have reported that fibrillar αSyn can activate the NLRP3 inflammasome in mice and in human monocytes (18–22), but it remains unknown if human brain microglia can be activated in this manner. Critically, antibodies targeting misfolded proteins are being tested in human clinical trials for several neurodegenerative diseases, including AD and PD; however, it is still unclear how antibodies to αSyn might affect this inflammatory response. In this study, we characterized the response of human induced pluripotent stem cell (hiPSC)-derived microglia (hiMG) to oligomeric/fibrillar αSyn in vitro and in vivo, using engraftment of hiMG in humanized mice. We used these immunocompromised mice because they prevent human cell rejection and express three human genes that support human cell engraftment (23). We show that αSyn and, even more so, αSyn–antibody complexes activate the NLRP3 inflammasome. Moreover, this process is further sensitized by the presence of Aβ and its cognate antibodies. These observations are of heightened interest because recent studies have shown that both misfolded Aβ and αSyn are present in several neurodegenerative disorders such as AD and Lewy body dementia (LBD), a form of dementia that can occur in the setting of PD (24–26).     

A Randomized Clinical Trial of Insulin Glargine and Aspart,Compared to NPH and Regular Insulin in Children with Type 1 Diabetes Mellitus

Objective

Appropriate treatment of patients with Type 1 diabetes mellitus (T1DM) is necessary to avoid further complications. This study was performed to compare the efficacy of insulin Glargine and Aspart with NPH insulin and regular insulin regimen in a group of children with T1DM.

Methods

Forty patients with T1DM were enrolled in this study. During run-in, all subjects were treated with conventional therapy consisting of twice-daily NPH and thrice-daily regular. Following randomization, 20 subjects received Glargine and Aspart and 20 subjects received NPH and Regular insulin.

Findings

Mean HbA1c was 8.8% and 8.6% at first and 8.4% and 8.2% at the end of study for subjects randomized initially to Glargine and Aspart and for those randomized to NPH and Regular, respectively (P>0.05). Mean fasting blood glucose (FBS) of the subjects randomized initially to Glargine and Aspart was 217±101 mg/dL, with no significant difference to 196±75 mg/dL for those randomized to NPH and Regular (P=0.48). This was also true at the end of the study. The difference in total cholesterol and triglyceride between the two groups in the beginning of study and at the end did not show any significance.

Conclusion

The current study showed no significant difference in glycemic control [Glycated hemoglobin (HbA1c) and FBS] and lipid profile (total cholesterol and triglyceride) between two regimes.     

Improved bone regeneration through amniotic membrane loaded with buccal fat pad-derived MSCs as an adjuvant in maxillomandibular reconstruction

BackgroundHuman amniotic membranes (HAMs), as a biological membrane with healing, osteogenic, and cell therapy potential, has been in the spotlight to enhance the outcomes of treating bone defects. Present study aims to clinically assess the potential of HAM loaded with buccal fat pad-derived stem cells (BFSCs) as an osteogenic coverage for onlay bone grafts to maxillomandibular bone defects.Materials and methodsNine patients with jaw bone defects were enrolled in the present study. The patients were allocated to two study groups: Iliac crest bone graft with HAM coverage (n = 5), and Iliac bone grafts covered with HAM loaded with BFSCs (n = 4). Five months following the grafting and prior to implant placement, cone beam computed tomography was performed for radiomorphometric analysis.ResultsThe mean increase in bone width was found to be significantly greater in the HAM + BFSCs group (4.42 ± 1.03 mm versus 3.07 ± 0.73 mm, p < 0.05). Further, the changes in vertical dimension were greater in the HAM + BFSCs group (4.66 ± 1.06 mm versus 4.14 ± 1.03 mm, p > 0.05).ConclusionCombined use of HAM with mesenchymal stem cells may enhance bone regeneration specifically in the horizontal dimension. Moreover, this methodology reduces the amount of harvested autogenous bone and diminish secondary bone resorption.