Pulmonary valve perforation with multiple cardiac anomalies: a case report.

BACKGROUND: Large pulmonary valve perforation, which is rarely seen with infective endocarditis, general atrophy, or congenital fenestration, often leads to potentially fatal outcomes, including heart failure. CASE PRESENTATION: Transthoracic and transesophageal echocardiographic evaluation of a 69-year-old woman revealed a severely eccentric pulmonary regurgitation with concomitant pulmonary valve stenosis, patent ductus arteriosus, patent foramen ovale, and pulmonary artery aneurysm. In the operation, a large perforation was found in the pulmonary valve leaflet. She underwent complicated surgery that involved closure of the congenital heart defects and replacement of a pulmonary valve with successful results. But the cause of her pulmonary valve perforation remained undetermined. CONCLUSION: This case highlights two important points: the need for timely management of congenital heart disease and being aware of the possibility of pulmonary valve perforation, which in this case was indicated by an eccentric pulmonary regurgitant jet seen on echocardiography.

Computational design of co-assembling protein-DNA nanowires.

Biomolecular self-assemblies are of great interest to nanotechnologists because of their functional versatility and their biocompatibility. Over the past decade, sophisticated single-component nanostructures composed exclusively of nucleic acids, peptides and proteins have been reported, and these nanostructures have been used in a wide range of applications, from drug delivery to molecular computing. Despite these successes, the development of hybrid co-assemblies of nucleic acids and proteins has remained elusive. Here we use computational protein design to create a protein-DNA co-assembling nanomaterial whose assembly is driven via non-covalent interactions. To achieve this, a homodimerization interface is engineered onto the Drosophila Engrailed homeodomain (ENH), allowing the dimerized protein complex to bind to two double-stranded DNA (dsDNA) molecules. By varying the arrangement of protein-binding sites on the dsDNA, an irregular bulk nanoparticle or a nanowire with single-molecule width can be spontaneously formed by mixing the protein and dsDNA building blocks. We characterize the protein-DNA nanowire using fluorescence microscopy, atomic force microscopy and X-ray crystallography, confirming that the nanowire is formed via the proposed mechanism. This work lays the foundation for the development of new classes of protein-DNA hybrid materials. Further applications can be explored by incorporating DNA origami, DNA aptamers and/or peptide epitopes into the protein-DNA framework presented here.

Highly multiplexed and quantitative cell-surface protein profiling using genetically barcoded antibodies.

Human cells express thousands of different surface proteins that can be used for cell classification, or to distinguish healthy and disease conditions. A method capable of profiling a substantial fraction of the surface proteome simultaneously and inexpensively would enable more accurate and complete classification of cell states. We present a highly multiplexed and quantitative surface proteomic method using genetically barcoded antibodies called phage-antibody next-generation sequencing (PhaNGS). Using 144 preselected antibodies displayed on filamentous phage (Fab-phage) against 44 receptor targets, we assess changes in B cell surface proteins after the development of drug resistance in a patient with acute lymphoblastic leukemia (ALL) and in adaptation to oncogene expression in a Myc-inducible Burkitt lymphoma model. We further show PhaNGS can be applied at the single-cell level. Our results reveal that a common set of proteins including FLT3, NCR3LG1, and ROR1 dominate the response to similar oncogenic perturbations in B cells. Linking high-affinity, selective, genetically encoded binders to NGS enables direct and highly multiplexed protein detection, comparable to RNA-sequencing for mRNA. PhaNGS has the potential to profile a substantial fraction of the surface proteome simultaneously and inexpensively to enable more accurate and complete classification of cell states.

Aortic Chordae Tendineae Strands with Significant Aortic Regurgitation.

The aortic chordae tendineae strands are suggested to be embryonic remnants of the cusp formation process. We herein describe a 70-year-old male who was admitted to our hospital for shortness of breath and chest tightness. During echocardiographic examination, severe aortic regurgitation with a ruptured fibrous strand was detected. Moreover, another fibrous strand was found by three-dimensional transesophageal echocardiography (TEE). To our knowledge, this is the first literature review of aortic chordae tendineae strands, including diagnosis, management, and mechanisms of aortic regurgitation due to such informal strands.

Overexpression of FNTB and the activation of Ras induce hypertrophy and promote apoptosis and autophagic cell death in cardiomyocytes.

Farnesyltransferase (FTase) is an important enzyme that catalyses the modification of protein isoprene downstream of the mevalonate pathway. Previous studies have shown that the tissue of the heart in the suprarenal abdominal aortic coarctation (AAC) group showed overexpression of FTaseß (FNTB) and the activation of the downstream protein Ras was enhanced. FTase inhibitor (FTI) can alleviate myocardial fibrosis and partly improve cardiac remodelling in spontaneously hypertensive rats. However, the exact role and mechanism of FTase in myocardial hypertrophy and remodelling are not fully understood. Here, we used recombinant adenovirus to transfect neonatal rat ventricular cardiomyocytes to study the effect of FNTB overexpression on myocardial remodelling and explore potential mechanisms. The results showed that overexpression of FNTB induces neonatal rat ventricular myocyte hypertrophy and reduces the survival rate of cardiomyocytes. FNTB overexpression induced a decrease in mitochondrial membrane potential and increased apoptosis in cardiomyocytes. FNTB overexpression also promotes autophagosome formation and the accumulation of autophagy substrate protein, LC3II. Transmission electron microscopy (TEM) and mCherry-GFP tandem fluorescent-tagged LC3 (tfLC3) showed that FNTB overexpression can activate autophagy flux by enhancing autophagosome conversion to autophagolysosome. Overactivated autophagy flux can be blocked by bafilomycin A1. In addition, salirasib (a Ras farnesylcysteine mimetic) can alleviate the hypertrophic phenotype of cardiomyocytes and inhibit the up-regulation of apoptosis and autophagy flux induced by FNTB overexpression. These results suggest that FTase may have a potential role in future treatment strategies to limit the adverse consequences of cardiac hypertrophy, cardiac dysfunction and heart failure.

Targeting Phosphotyrosine in Native Proteins with Conditional, Bispecific Antibody Traps.

Engineering sequence-specific antibodies (Abs) against phosphotyrosine (pY) motifs embedded in folded polypeptides remains highly challenging because of the stringent requirement for simultaneous recognition of the pY motif and the surrounding folded protein epitope. Here, we present a method named phosphotyrosine Targeting by Recombinant Ab Pair, or pY-TRAP, for in vitro engineering of binders for native pY proteins. Specifically, we create the pY protein by unnatural amino acid misincorporation, mutagenize a universal pY-binding Ab to create a first binder B1 for the pY motif on the pY protein, and then select against the B1-pY protein complex for a second binder B2 that recognizes the composite epitope of B1 and the pY-containing protein complex. We applied pY-TRAP to create highly specific binders to folded Ub-pY59, a rarely studied Ub phosphoform exclusively observed in cancerous tissues, and ZAP70-pY248, a kinase phosphoform regulated in feedback signaling pathways in T cells. The pY-TRAPs do not have detectable binding to wild-type proteins or to other pY peptides or proteins tested. This pY-TRAP approach serves as a generalizable method for engineering sequence-specific Ab binders to native pY proteins.

Giant Right Coronary Artery Aneurysm Resembling Cardiac Tumor: A Case Report.

BACKGROUND: Coronary artery aneurysms are not uncommon vascular anomalies, but giant coronary artery aneurysms mimicking cardiac tumors are extremely rare and easily misdiagnosed as tumors. The management and prognosis are not well defined. CASE REPORT: We describe a case of a 50-year-old woman, who had a transthoracic echocardiogram that suggested a cardiac tumor in the right ventricle adjacent to the tricuspid valve and without ventricular wall akinesia. Her medical history was unremarkable, and she had no obvious symptoms. A transesophageal echocardiogram and computed tomography angiogram examination suggested the tumor-like structure was a giant coronary aneurysm, originating from the distal portion of right coronary artery. The patient underwent surgical intervention and recovered uneventfully. Histopathology of the excised aneurysm showed fibrous tissue hyperplasia with collagenization and calcification in the wall of the artery. CONCLUSION: Giant coronary artery aneurysms resembling heart tumors are extremely rare. Differentiating them from cardiac tumors can sometimes be difficult. This rare case emphasizes the importance of combining multiple imaging methods, which helps make accurate diagnosis. For treatment, surgical intervention may be the appropriate therapeutic strategy for the rare lesion.

Using response surface methodology optimize culture conditions for human lactoferrin production in desert Chlorella.

To optimize the expression conditions for human lactoferrin production, we have constructed the transgenic chlorella with human lactoferrin named as GTD8A1-HLF, the original chlorella was separated from Gurbantunggut Desert in Xinjiang China. To further improve the production of human lactoferrin, a sequential methodology was used to optimize human lactoferrin production by GTD8A1-HLF. First, a screening trial using a Plackett-Burman design was done, and variables with statistically significant effects on human lactoferrin bio-production were identified. These were further optimized by central composite design experiments and response surface methodology. Finally, we found that the maximum human lactoferrin production (52.70 mg/L) was achieved under the following optimized conditions: Initial pH 5.0, NaNO3 concentration of 0.600 mol/L, FeSO4 concentration of 0.006 mol/L, and a CuSO4 concentration of 0.002 mol/L, with the other medium components constituting the basal culture medium BBM. The yield of HLF protein under optimized culture conditions was approximately 4-fold higher than that obtained by using the basal culture medium BBM. The findings are significant for the potential industrial use of GTD8A1-HLF.

Engineering Improved Antiphosphotyrosine Antibodies Based on an Immunoconvergent Binding Motif.

Phosphotyrosine (pY) is one of the most highly studied posttranslational modifications that is responsible for tightly regulating many signaling pathways in eukaryotes. Pan-specific pY antibodies have emerged as powerful tools for understanding the role of these modifications. Nevertheless, structures have not been reported for pan-specific pY antibodies, greatly impeding the further development of tools for integrating this ubiquitous posttranslational modification using structure-guided designs. Here, we present the first crystal structures of two widely utilized pan-specific pY antibodies, PY20 and 4G10. The two antibodies, although developed independently from animal immunizations, have surprisingly similar modes of recognition of the phosphate group, implicating a generic binding structure among pan-specific pY antibodies. Sequence alignments revealed that many pY binding residues are predominant in the mouse V germline genes, which consequently led to the convergent antibodies. On the basis of the convergent structure, we designed a phage display library by lengthening the CDR-L3 loop with the aid of computational modeling. Panning with this library resulted in a series of 4G10 variants with 4 to 11-fold improvements in pY binding affinities. The crystal structure of one improved variant showed remarkable superposition to the computational model, where the lengthened CDR-L3 loop creates an additional hydrogen bond indirectly bound to the phosphate group via a water molecule. The engineered variants exhibited superior performance in Western blot and immunofluorescence.

Multiphoton structured thin-plane imaging with a single optical path.

Optical sectioning has become an indispensable technique for high-speed volumetric imaging in the past decade. Here we present a novel optical-sectioning method that produces a thin plane of illumination by exploiting the spatial and temporal properties of multiphoton excitation. Critically, the illumination and detection share the same optical path, as in a conventional epi-fluorescence microscope configuration. Therefore, the imaged sample can be prepared as for standard fluorescence microscopy. Our method also leads to a laterally structured illumination pattern, and this feature can be utilized in structured illumination microscopy to further enhance the imaging performance. We show an example of such an approach, which achieves axial resolution finer than confocal microscopy. We also demonstrate the potential of the new method for biological applications by performing three-dimensional imaging of living Caenorhabditis elegans.

Enhanced light extraction of deep ultraviolet light-emitting diodes by using optimized aluminum reflector.

Deep ultraviolet light-emitting diodes (DUV-LEDs) have become a promising UV light source for sterilization, disinfection, and purification. However, the challenge in practical application of DUV-LEDs still remains in their low light efficiency. In this paper, we propose an optimized aluminum (Al) reflector for the light extraction enhancement of DUV-LEDs. The optical model of DUV-LEDs was established, and the optical simulations were performed to achieve the optimized reflector. The DUV-LEDs exhibit the highest light efficiency when the reflector has the optimized feature sizes with an angle of 60°, a height of 2.0 mm, and an internal radius of 2.5 mm. Furthermore, the optimized reflector with different reflectance was fabricated and applied for the packaging of DUV-LEDs. Consequently, the light output powers of DUV-LEDs are enhanced by 28.8%, 37.0%, and 43.8%, respectively, by using the different reflectors at the driving current of 100 mA. It is attributed to the remarkable reflection effect of the Al reflector, which increases the light extraction of the sidewall emission from the DUV-LED chip.

Computational design and experimental verification of a symmetric protein homodimer.

Homodimers are the most common type of protein assembly in nature and have distinct features compared with heterodimers and higher order oligomers. Understanding homodimer interactions at the atomic level is critical both for elucidating their biological mechanisms of action and for accurate modeling of complexes of unknown structure. Computation-based design of novel protein-protein interfaces can serve as a bottom-up method to further our understanding of protein interactions. Previous studies have demonstrated that the de novo design of homodimers can be achieved to atomic-level accuracy by ß-strand assembly or through metal-mediated interactions. Here, we report the design and experimental characterization of a α-helix-mediated homodimer with C2 symmetry based on a monomeric Drosophila engrailed homeodomain scaffold. A solution NMR structure shows that the homodimer exhibits parallel helical packing similar to the design model. Because the mutations leading to dimer formation resulted in poor thermostability of the system, design success was facilitated by the introduction of independent thermostabilizing mutations into the scaffold. This two-step design approach, function and stabilization, is likely to be generally applicable, especially if the desired scaffold is of low thermostability.

Thermally stable multi-color phosphor-in-glass bonded on flip-chip UV-LEDs for chromaticity-tunable WLEDs.

In this paper, we propose a thermally stable multi-color phosphor-in-glass (PiG) for chromaticity-tunable white light-emitting diodes (WLEDs). The multi-color PiG has a red, green, and blue (RGB) phosphor glass layer, which was screen-printed and co-sintered on a glass plate with a low temperature of 600°C. The WLED with ultra-compact structure was fabricated by the RGB-PiG directly bonded on a flip-chip ultraviolet (UV) LED. By controlling the weight ratio of R∶G∶B phosphors, the thickness of the RGB layer, and the weight ratio of phosphors to glass powders (PtG), the chromaticity of RGB-PiG based WLEDs can be effectively tuned with high color quality. With the R∶G∶B ratio of 2∶3∶2, the RGB thickness of 75 µm, and the PtG ratio of 2∶1, the RGB-PiG based WLED achieves a natural white light with a luminous efficacy (LE) of 27.8 lm/W, a correlated color temperature of 4245 K, and a color rendering index of 92.6 at the current of 350 mA. The LE losses of the RGB-PiG based and RGB phosphor-in-silicone based WLEDs are 4.7% and 14.6% after the aging tests of 1000 h at 100°C, respectively. The results demonstrate that the multi-color PiG is a promising converter for UV-excited WLEDs.

Alteration of RhoA Prenylation Ameliorates Cardiac and Vascular Remodeling in Spontaneously Hypertensive Rats.

BACKGROUND: In our previous study, farnesyl pyrophosphate synthase (FPPS) was shown to be increased in spontaneously hypertensive rats (SHR) and in mice with angiotensin-II induced cardiac hypertrophy. Overexpression of FPPS induced cardiac hypertrophy and fibrosis in mice, accompanied by an increase in the synthesis of farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). In the present study, we investigated the mechanisms of reversing cardiovascular remodeling in SHR by inhibiting FPPS. METHODS AND RESULTS: Six-week-old rats were given vehicle or an FPPS inhibitor (alendronate, 100 ug/kg/d) daily for twelve weeks by osmotic mini-pump. The results demonstrated that FPPS inhibition attenuated cardiac hypertrophy and fibrosis in SHR as shown by the heart weight to body weight ratio, echocardiographic parameters, and histological examination. In addition, FPPS inhibition attenuated aortic remodeling as shown by reduced media thickness, media cross-sectional area and collagen of the aorta as well as SBP, DBP, MBP. Furthermore, 12 weeks of alendronate treatment significantly decreased FPP and GGPP levels, RhoA activation and geranylgeranylation in the heart and aorta, all of which were significantly upregulated in SHR compared with normotensive Wistar-Kyoto rats. CONCLUSION: Taken together, these results indicate that chronic treatment with alendronate decreases the development of cardiac and aortic remodeling, by a pathway which involves inhibition of the geranylgeranylation and activation of RhoA.

Preliminary results of ultrasound-guided laser ablation for unresectable metastases to retroperitoneal and hepatic portal lymph nodes.

BACKGROUND: Laser ablation with a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser is a minimally invasive approach which is able to achieve a precise tissue necrosis. The study was aimed to assess the feasibility and efficiency of laser ablation in the treatment of retroperitoneal and hepatic portal unresectable metastatic lymph nodes. METHODS: Eight patients including 11 pathologically proven metastatic lymph nodes, 4 in retroperitoneal, 7 in hepatic portal region, were treated by laser ablation. Primary cancers were cholangiocarcinoma (n = 4) and hepatocellular carcinoma (n = 4). Under sonographic guidance, the laser ablation was performed percutaneously. Follow-up contrast computed tomography or magnetic resonance image was performed. RESULTS: The treatments were completed in single process in all the patients. No severe complications occurred. Follow-up contrast computed tomography or magnetic resonance imaging at 1 and 3 months showed partial responses in 11 lymph nodes. The local response rate at the 6 month follow-up was 75.0 %. The overall response rate was 62.5 %. Abdominal pain scores decreased significantly in all patients. Tumor marker levels decreased in six patients. The Child-Pugh grade did not change. CONCLUSIONS: The results suggest that sonographically guided laser ablation is technically feasible for the local treatment of unresectable retroperitoneal and hepatic portal lymph nodes from hepatic cancer. Although further study is needed to evaluate its long time efficacy, abdominal pain relief is prominent.

Transient cardiac injury during H7N9 infection.

BACKGROUND: Recent reports have characterized virological and clinical features of the novel reassortant avian-origin influenza A (H7N9) virus. However, cardiovascular involvement during H7N9 infection is still unclear. In this study, we evaluate cardiac injury among H7N9-infected patients. MATERIALS AND METHODS: A total of 40 patients who were laboratory-confirmed with H7N9 infection were retrospectively included and grouped by Acute Physiology and Chronic Health Evaluation II (APACHE II) score into four subgroups I(0-10), II(11-20), III(21-30) and IV(31-71). Cardiovascular complications and markers of cardiac injury including creatinine kinase (CK), CK iso-enzyme (CK-MB), cardiac troponin I (cTNI) and brain natriuretic peptide (BNP) were assessed. Electrocardiogram (ECG) and echocardiography (ECHO) were also performed. RESULTS: Half of patients manifested with cardiovascular complications, with hypotension (47.5%) and heart failure (40.0%) the most prevalent. CK, CK-MB and cTNI showed marked increase with H7N9 virus infection but significantly decreased after H7N9 viral tests turned negative. More than half of patients presented with an abnormal ECG, but most of them are benign changes. ECHO examination showed different degree of impairment of cardiac function. Pulmonary artery systolic pressure was increased in all groups. Cardiac damage was more evident in patients with higher APACHE II score. CONCLUSIONS: H7N9 virus exerts a transient impairment on the cardiovascular system. Patients with a higher APACHE II score are more susceptible to cardiac damage.

Late stent migration into the right ventricle in a patient with nutcracker syndrome.

BACKGROUND: Stent migration into the right ventricle is rare in patients treated with endovenous stenting, but can have potentially serious complications including endocarditis, cardiac arrhythmias, and heart failure. METHODS: We present a case of stent migration into the right ventricle 5 months after stent placement in a patient with nutcracker syndrome. RESULTS: Echocardiography revealed a stent caught within the subvalvular chordal structures, with significant tricuspid regurgitation. Subsequent severe damage to the tricuspid apparatus necessitated prosthetic valve replacement, as tricuspid valvuloplasty failed after stent removal. CONCLUSIONS: Because stent migration is a potential complication in left renal vein stenting that can occur up to 5 months after intervention therapy, follow-up using ultrasonography is necessary. In addition, knowing the precise location of the stent, which is important for subsequent treatment, is essential when transabdominal ultrasonography reveals the absence of the stent in the left renal vein.

Autophagy protects against senescence and apoptosis via the RAS-mitochondria in high-glucose-induced endothelial cells.

BACKGROUNDS: Autophagy is an important process in the pathogenesis of diabetes and plays a critical role in maintaining cellular homeostasis. However, the autophagic response and its mechanism in diabetic vascular endothelium remain unclear. METHODS AND RESULTS: We studied high-glucose-induced renin-angiotensin system (RAS)-mitochondrial damage and its effect on endothelial cells. With regard to therapeutics, we investigated the beneficial effect of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II type 1 receptor blockers (ARBs) against high-glucose-induced endothelial responses. High glucose activated RAS, enhanced mitochondrial damage and increased senescence, apoptosis and autophagic-responses in endothelial cells, and these effects were mimicked by using angiotensin II (Ang). The use of an ACEI or ARB, however, inhibited the negative effects of high glucose. Direct mitochondrial injury caused by carbonyl cyanide 3-chlorophenylhydrazone (CCCP) resulted in similar negative effects of high glucose or Ang and abrogated the protective effects of an ACEI or ARB. Additionally, by impairing autophagy, high-glucose-induced senescence and apoptosis were accelerated and the ACEI- or ARB-mediated beneficial effects were abolished. Furthermore, increases in FragEL™ DNA Fragmentation (TUNEL)-positive cells, ß-galactosidase activation and the expression of autophagic biomarkers were revealed in diabetic patients and rats, and the treatment with an ACEI or ARB decreased these responses. CONCLUSIONS: These data suggest that autophagy protects against senescence and apoptosis via RAS-mitochondria in high-glucose-induced endothelial cells.

Purification of recombinant nacre-associated mineralization protein AP7 fused with maltose-binding protein.

Formation of biominerals often involves specific proteins that modulate the process of matrix assembly, nucleation, and crystal growth. AP7 is an aragonite-associated protein of 7 kDa and is intrinsically disordered. The structural disorder of AP7 makes it very difficult to express in Escherchiacoli. In this work, we report the first successful expression and purification of recombinant AP7 using the maltose-binding protein (MBP) fusion approach. We obtain a high-yield production of recombinant MBP-AP7 protein inE. coli (∼60 mg/L). We also establish an efficient protocol to remove the MBP fusion protein by Factor Xa, followed by purification using size-exclusion chromatography. Characterization of the recombinant AP7 protein has been carried out using MALDI-TOF, peptide mass fingerprinting, and circular dichroism (CD). The mass data confirm that the purified recombinant protein is AP7. The CD data suggest that the recombinant AP7 protein exists as partially disordered structure at neutral pH. The calcium carbonate precipitation assay shows that both MBP-AP7 and AP7 exhibit morphological modification on calcite crystallites. The co-precipitation of MBP-tagged AP7 derivatives and calcium carbonate generate different types of AP7 composite calcite and vaterite crystals. This system should be helpful to establish a model for understanding the structure/function relationship between the protein and inorganic mineral interaction.

Giant uterine artery pseudoaneurysm after a missed miscarriage termination in a cesarean scar pregnancy.

BACKGROUND: Uterine artery pseudoaneurysms are dangerous and can lead to severe hemorrhage. We report an uncommon cause of a giant pseudoaneurysm in a missed miscarriage in a woman with a cesarean scar pregnancy. CASE PRESENTATION: The patient was a 25-year-old Chinese woman with a missed miscarriage in a cesarean scar pregnancy. Curettage was performed under ultrasound monitoring. A uterine artery pseudoaneurysm measuring 71 × 44 × 39 mm was detected the next day by Doppler ultrasonography. While waiting for admittance to an advanced institution to undergo embolization treatment, the pseudoaneurysm ruptured spontaneously. The subsequent severe hemorrhage necessitated hysterectomy. CONCLUSION: A delay in diagnosis of uterine artery pseudoaneurysms may result from a long period between the curettage and follow-up examination. Ultrasound and Doppler ultrasonography should be performed repeatedly at short intervals to rule out them, especially in cesarean scar pregnancies. For a giant uterine artery pseudoaneurysm, interventional embolization might be the first treatment choice. If time allows, intra-operative ligation of the feeding vessels should be attempted before any decision to perform a hysterectomy is made. However, hysterectomy remains a possibility when severe bleeding occurs.