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Background: Sheehan's syndrome occurs because of severe postpartum hemorrhage causing ischemic pituitary necrosis. Sheehan's syndrome is a well-known condition that is generally diagnosed several years postpartum. However, acute Sheehan's syndrome is rare, and clinicians have little exposure to it. It can be life-threatening. There have been no reviews of acute Sheehan's syndrome and no reports of successful pregnancies after acute Sheehan's syndrome. We present such a case, and to understand this rare condition, we have reviewed and discussed the literature pertaining to it. An electronic search for acute Sheehan's syndrome in the literature from January 1990 and May 2014 was performed.Case Presentation: A 27-year-old woman had massive postpartum hemorrhage (approximately 5000 mL) at her first delivery due to atonic bleeding. She was transfused and treated with uterine embolization, which successfully stopped the bleeding. The postpartum period was uncomplicated through day 7 following the hemorrhage. However, on day 8, the patient had sudden onset of seizures and subsequently became comatose. Laboratory results revealed hypothyroidism, hypoglycemia, hypoprolactinemia, and adrenal insufficiency. Thus, the patient was diagnosed with acute Sheehan's syndrome. Following treatment with thyroxine and hydrocortisone, her condition improved, and she was discharged on day 24. Her next pregnancy was established 2 years after her first delivery. She required induction of ovulation for the next conception. The pregnancy, delivery, and postpartum period were uneventful. An electronic search of the literature yielded 21 cases of acute Sheehan's syndrome. Presenting signs varied, including adrenal insufficiency (12 cases), diabetes insipidus (4 cases), hypothyroidism (2 cases), and panhypopituitarism (3 cases), with a median time of presentation after delivery for each of those conditions being 7.9, 4, 18, and 9 days, respectively. Serial changes in magnetic resonance imaging were reported in some cases of acute Sheehan's syndrome.Conclusion: Clinicians should be aware of the risk of acute Sheehan's syndrome after a massive postpartum hemorrhage in order to diagnose it accurately and treat it promptly. [ABSTRACT FROM AUTHOR]

Here, we report the direct visualization of the assembly/disassembly processes of photoresponsive DNA origami nanostructures which can be placed on a lipid bilayer surface. The observation relies on controlled interactions between the bilayer components and cholesterol moieties introduced to the hexagonal origami structures, one of whose outer edges carries Azo-ODNs. The bilayer-placed hexagonal dimer was disassembled into monomer units by UV irradiation, and reversibly assembled again during visible light irradiation. These dynamic processes were directly monitored with high-speed atomic force microscopy. The successful application of our approach should facilitate studies of interactive and functional behaviors of various DNA nanostructures. [ABSTRACT FROM AUTHOR]

Site-specific recombination involves reciprocal exchange between defined DNA sites. The reaction initiates from the formation of a recombinase-DNA synaptic complex, in which two recombination sites arrange in an appropriate configuration. However, there is incomplete information about how the topological state of the substrate influences the synapsis and outcome of the reaction. Here, we show that Cremediated recombination can be regulated by controlling the orientation and topology of the loxP substrate in a DNA frame nanoscaffold. High-speed atomic force microscopy analyses revealed that the loxP-containing substrate strands in the antiparallel orientation can be recombined only through formation of synaptic complexes. By tethering Holliday junction (HJ) intermediates to DNA frames in different connection patterns and using them as a starting substrate, we found that the topological state of the HJ intermediates dictates the outcome of the resolution. Our approach should provide a new platform for structural-functional studies of various DNA targeting enzymes, especially which require formation of synaptic complexes. [ABSTRACT FROM AUTHOR]

HIV-1 nucleocapsid proteins (NCps) facilitate remodeling of nucleic acids to fold thermodynamically stable conformations, and thus called nucleic acid chaperones. To date only little is known on the stoichiometry, NCp--NCp interactions, chaperone activity on G-quadruplex formation, and so on. We report here the direct and real-time analysis on such properties of proteolytic intermediate NCp 15 and mature NCp7 using DNA origami. The protein particles were found to predominantly exist in monomeric form, while dimeric and multimeric forms were also observed both in free solution and bound to the quadruplex structure. The formation and the dissociation events of the G-quadruplexes were well documented in real-time and the intermediate-like states were also visualized. We anticipate that this pioneering study will strengthen our understanding on the chaperone activity of HIV-1 proteins which in turn will be helpful for the drug design based on G-quadruplex and also for the development of drugs against AIDS. [ABSTRACT FROM AUTHOR]

The local change in the three different structures of restriction enzyme BamHI, which include DNA-free dimer and non-specific and specific complexes with DNA, were detected by the fluorescence from a site-selectively introduced solvatochromic fluorophore Nβ-l-alanyl-5-(N,N-dimethylamino)naphthalene-1-sulfonamide (DanAla). According to the crystal structure, α-helices of the non-specific complex containing Ile82, Glu86 and Trp206 residues are converted into random coil by the formation of specific complex with a substrate. To understand the microenvironmental change caused by the structural transition around these positions, the DanAla probe was site-specifically introduced into the positions, and steady-state and time-resolved fluorescence was observed. The steady-state fluorescence gave us information that the rigidity of the polypeptide chains would be enhanced by the formation of the specific complex. The time-resolved fluorescence supported that the change in a water molecule-accessible space was induced by DNA-binding. We revealed that the change in rigidity and solvation around the specific positions was detected by the characteristic fluorescence using the combination of steady-state and time-resolved fluorescence techniques. [ABSTRACT FROM AUTHOR]

To detect the local structural change in an interface between proteins induced by the substrate binding and dissociation, a solvatochromic fluorescent N-L-alanyl-5-(N,N-dimethylamino)-naphthalene-1-sulfonamide (DanAla) was introduced into 132 position of the dimer interface in BamHI. Before addition of the substrate, the fluorescence from the normal planer excited state of DanAla moiety was observed as a main emission, and thereby the DanAla in the dimer interface is located in the hydrophobic microenvironment. The incubation with the substrate for 20 min induced the gradual increase in fluorescence intensity around 430 nm. The fact reflects that the polarity is reduced by the slight structural change initiated by the formation of the complex with the substrate. Furthermore, the incubation for more than 20 min caused the slight decrease in fluorescence around 430 nm and an appearance of fluorescence (560 nm) due to twisted intramolecular charge transfer (TICT) excited state. Therefore, the DanAla is exposed to comparative polar environment after the dissociation of the substrate. The fluorescence lifetime as a minor component, which is attributed to the TICT excited state, was reduced by addition of the substrate. The results provide that the hydrophobicity in the dimer interface is increased by the substrate binding. Interestingly, we found that the structure of an initial form is different from that of a refolded form after the dissociation of the substrate using a spectral subtraction technique. We have achieved detection of the changing structure induced by the substrate binding and dissociation using a steady-state and time-resolved fluorescence. [ABSTRACT FROM AUTHOR]

To create a nanoscale dual switch, two responsive DNA motifs, azobenzene-modified DNAs and G-telomeric repeat sequences, were introduced together into the nanoframe system. The dualswitching behaviors controlled by photoirradiation and K+ were successfully visualized in real time by high-speed atomic force microscopy. [ABSTRACT FROM AUTHOR]

Background: Placenta percreta is a rare obstetric condition associated with the risk of massive intraoperative hemorrhage. Recently, conservative management of placenta percreta has been performed to reduce maternal morbidity. However, various complications have been reported during such management. Only a few cases of asymptomatic disseminated intravascular coagulation (DIC) or fever without infection have been reported. Here, we discuss such a case and review the related literature to understand this rare condition better. For this, we performed an electronic literature review.Case Presentation: We present the clinical course, results of blood tests, and serial magnetic resonance images of a 35-year-old female (gravida 5, para 2) with placenta percreta complicated by placenta previa that was managed conservatively. The patient successfully delivered a healthy baby by a cesarean delivery via a transverse uterine fundal incision at 36 weeks of gestation. We did not observe intraoperative complications during cesarean delivery, and the postoperative course remained uncomplicated until 47 days after the delivery. However, asymptomatic DIC developed after 47 days, and her serum fibrinogen level declined to 42 mg/dL, which was successfully treated with anticoagulant therapy by a therapeutic dose of intravenous heparin for 22 days (postoperative days 48-69). Although DIC resolved, subsequent fever persisted for approximately 1 month (postoperative days 67-103). Infection was ruled out, and conservative management was successfully continued. Literature review revealed that successful conservative management of a patient with asymptomatic DIC and subsequent fever without infection is extremely rare.Conclusions: Some patients with DIC and fever can continue conservative management of placenta percreta, although careful examination and monitoring are needed. [ABSTRACT FROM AUTHOR]

Compaction of bulky DNA is a universal issue for all DNA-based life forms. Chloroplast nucleoids (chloroplast DNA-protein complexes) are critical for chloroplast DNA maintenance and transcription, thereby supporting photosynthesis, but their detailed structure remains enigmatic. Our proteomic analysis of chloroplast nucleoids of the green alga Chlamydomonas reinhardtii identified a protein (HBD1) with a tandem repeat of two DNA-binding high mobility group box (HMG-box) domains, which is structurally similar to major mitochondrial nucleoid proteins transcription factor A, mitochondrial (TFAM), and ARS binding factor 2 protein (Abf2p). Disruption of the HBD1 gene by CRISPR-Cas9-mediated genome editing resulted in the scattering of chloroplast nucleoids. This phenotype was complemented when intact HBD1 was reintroduced, whereas a truncated HBD1 with a single HMG-box domain failed to complement the phenotype. Furthermore, ectopic expression of HBD1 in the mitochondria of yeast ?abf2 mutant successfully complemented the defects, suggesting functional similarity between HBD1 and Abf2p. Furthermore, in vitro assays of HBD1, including the electrophoretic mobility shift assay and DNA origami/atomic force microscopy, showed that HBD1 is capable of introducing U-turns and cross-strand bridges, indicating that proteins with two HMG-box domains would function as DNA clips to compact DNA in both chloroplast and mitochondrial nucleoids. [ABSTRACT FROM AUTHOR]

We report the use of DNA origami nanostructures, functionalized with aptamers, as a vehicle for delivering the antibacterial enzyme lysozyme in a specific and efficient manner. We test the system against Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) targets. We use direct stochastic optical reconstruction microscopy (dSTORM) and atomic force microscopy (AFM) to characterize the DNA origami nanostructures and structured illumination microscopy (SIM) to assess the binding of the origami to the bacteria. We show that treatment with lysozyme-functionalized origami slows bacterial growth more effectively than treatment with free lysozyme. Our study introduces DNA origami as a tool in the fight against antibiotic resistance, and our results demonstrate the specificity and efficiency of the nanostructure as a drug delivery vehicle. [ABSTRACT FROM AUTHOR]

Due to the small size of a nanoconfinement, the property of water contained inside is rather challenging to probe. Herein, we measured the amount of water molecules released during the folding of individual G-quadruplex and i-motif structures, from which water activities are estimated in the DNA nanocages prepared by 5 × 5 to 7 × 7 helix bundles (cross-sections, 9 × 9 to 15 × 15 nm). We found water activities decrease with reducing cage size. In the 9 × 9-nm cage, water activity was reduced beyond the reach of regular cosolutes such as polyethylene glycol (PEG). With this set of nanocages, we were able to retrieve the change in water molecules throughout the folding trajectory of G-quadruplex or i-motif. We found that water molecules absorbed from the unfolded to the transition states are much fewer than those lost from the transition to the folded states. The overall loss of water therefore drives the folding of G-quadruplex or i-motif in nanocages with reduced water activities. [ABSTRACT FROM AUTHOR]

Holliday junctions, four-stranded DNA structures formed during homologous recombination, are disentangled by resolvases that have been found in prokaryotes and eukaryotes but not in plant organelles. Here, we identify monokaryotic chloroplast 1 (MOC1) as a Holliday junction resolvase in chloroplasts by analyzing a green alga Chlamydomonas reinhardtii mutant defective in chloroplast nucleoid (DNA-protein complex) segregation. MOC1 is structurally similar to a bacterial Holliday junction resolvase, resistance to ultraviolet (Ruv) C, and genetically conserved among green plants. Reduced or no expression of MOC1 in Arabidopsis thaliana leads to growth defects and aberrant chloroplast nucleoid segregation. In vitro biochemical analysis and high-speed atomic force microscopic analysis revealed that A. thaliana MOC 1 (AtMOC1) binds and cleaves the core of Holliday junctions symmetrically. MOC1 may mediate chloroplast nucleoid segregation in green plants by resolving Holliday junctions. [ABSTRACT FROM AUTHOR]

RNA is a biopolymer that is attractive for constructing nano-scale objects with complex structures. Threedimensional (3D) structures of naturally occurring RNAs often have modular architectures. The 3D structure of a group I (GI) ribozyme from Tetrahymena has a typical modular architecture, which can be separated into two structural modules ("P5 and P5abc). The fully active ribozyme can be reconstructed by assembling the two separately prepared modules through highly specific and strong assembly between "P5 ribozyme and P5abc RNA. Such non-covalent assembly of the two modules allows the design of polygonal RNA nano-structures. Through rational redesign of the parent GI ribozyme, we constructed variant GI ribozymes as unit RNAs for polygonal-shaped (closed) oligomers with catalytic activity. Programmed trimerization and tetramerization of the unit RNAs afforded catalytically active nano-sized RNA triangles and squares, the structures of which were directly observed by atomic force microscopy (AFM). [ABSTRACT FROM AUTHOR]

A light-driven artificial molecularnanomachine was constructed based on DNA scaffolding. Pyrene-modifiedwalking strands and disulfide bond-connected stator strands, employedas anchorage sites to support walker movement, were assembled intoa 2D DNA tile. Pyrene molecules excited by photoirradiation at 350nm induced cleavage of disulfide bond-connected stator strands, enablingthe DNA walker to migrate from one cleaved stator to the next on theDNA tile. The time-dependent movement of the walker was observed andthe entire walking process of the walker was characterized by distributionof the walker-stator duplex at four anchorage sites on the tile under different irradiation times.Importantly, the light-fuelled mechanical movements on DNA tile werefirst visualized in real time during UV irradiation using high-speedatomic force microscopy (HS-AFM). [ABSTRACT FROM AUTHOR]

DNAdendrimers consisting of several branched DNA units connectedto each other using DNA ligase were quite effective for the deliveryof immunostimulatory CpG DNA to immune cells. Therapeutic applicationof such DNA dendrimers, however, is hampered by the use of the ligase.Here, we report that self-assembling DNA dendrimers with high immunostimulatorypotency can be prepared without DNA ligases. Annealing of DNA consistingof DNA units with elongated adhesive ends resulted in the formationof DNA dendrimers. Atomic force microscopy revealed that the severalpreparations of DNA dendrimers resulted in dendritic structures asdesigned. The cellular uptake of DNA dendrimers by mouse macrophage-likeRAW264.7 cells and subsequent release of tumor necrosis factor-αwere dependent on the structural complexity of the dendrimers. Theseresults indicate that the ligation-free, self-assembling DNA dendrimersare a potent system for the delivery of immunostimulatory CpG DNAto immune cells. [ABSTRACT FROM AUTHOR]

Controllable fabrication of DNA origami structures was achieved using cationic comb-type copolymers (CCCs) as locks and polyvinyl sulphonic acid (PVS) as a key. A CCC binds to the phosphate backbone of either M13mp18/staples alone or both together and restricts origami folding, while PVS unlocks the CCC, restoring the formation of origami structures. [ABSTRACT FROM AUTHOR]

Aims and Objectives: Ethanol is widely used for the embolization treatment of vascular malformations, but it can also cause serious complications such us pulmonary hypertension, cardiopulmonary collapse and death. The complications are considered secondary to pulmonary vasospasm and ethanol-induced sludge embolism, etc., We studied the hemodynamic effects of intravenous absolute ethanol injection and ethanol sludge injection in pigs. Materials and Methods: A total of 5 pigs underwent intravenous injection of ex vivo generated ethanol-induced sludge in which residual ethanol was removed (Group S) and 4 pigs underwent intravenous injection of absolute ethanol (Group E). Hemodynamic parameters related to the pulmonary and systemic circulation were compared between the groups. Results: Transient pulmonary hypertension was observed in both groups and the hemodynamic changes were similar in both groups. Conclusions: Sludge can induce transient pulmonary hypertension or cardiopulmonary collapse, without ethanol and may be the mechanism by which ethanol induces its adverse hemodynamic effects. [ABSTRACT FROM AUTHOR]