648 research outputs found
Transcatheter arterial embolization for traumatic mesenteric bleeding: a 15-year, single-center experience
PURPOSE:We aimed to assess the safety and effectiveness of transcatheter arterial embolization (TAE) for mesenteric bleeding following trauma.METHODS:From 2001 to 2015, 12 patients were referred to our interventional unit for mesenteric bleeding following trauma, based on clinical decisions and computed tomography (CT) images. After excluding one patient with no bleeding focus and one patient who underwent emergency surgery, a total of 10 patients (male:female ratio, 9:1; mean age, 52.1 years) who underwent super selective TAE of visceral arteries were included in this study. Technical and clinical success, complications, and 30-day mortality rate were analyzed.RESULTS:In 10 patients who underwent TAE, the types of trauma were motor vehicle collision (n=6), fall (n=2), assault (n=1), and penetrating injury (n=1), and the bleeding arteries were in the pancreaticoduodenal arterial arcade (n=4), jejunal artery (n=3), colic artery (n=2), and sigmoid artery (n=1). N-butyl-2-cyanoacrylate (NBCA) (n=2), microcoils (n=2), and combinations of NBCA, microcoils, or gelatin sponge particles (n=6) were used as embolic agents. Technical success was achieved in all 10 patients, with immediate cessation of bleeding. Clinical success rate was 90% (9/10), and all patients were discharged with no further treatment required for mesenteric bleeding. However, one patient showed rebleeding 10 days later and underwent repeated TAE with successful result. There were no TAE-related ischemic complications such as bowel infarction. The 30-day mortality rate was 0%.CONCLUSION:Our clinical experience suggests that TAE used to control mesenteric bleeding following trauma is safe and effective as a minimally invasive alternative to surgery
A novel de novo mutation in the serine-threonine kinase STK11 gene in a Korean patient with Peutz-Jeghers syndrome
BACKGROUND: Peutz-Jeghers syndrome (PJS) is an unusual autosomal dominant disorder characterized by mucocutaneous pigmentation and multiple gastrointestinal hamartomatous polyps. Patients with PJS are at an increased risk of developing multi-organ cancer, most frequently those involving the gastrointestinal tract. Germline mutation of the STK11 gene, which encodes a serine-threonine kinase, is responsible for PJS. METHODS: Using DNA samples obtained from the patient and his family members, we sequenced nine exons and flanking intron regions of the STK11 gene using polymerase chain reaction (PCR) and direct sequencing. RESULTS: Sequencing of the STK11 gene in the proband of the family revealed a novel 1-base pair deletion of guanine (G) in exon 6 (c.826delG; Gly276AlafsX11). This mutation resulted in a premature termination at codon 286, predicting a partial loss of the kinase domain and complete loss of the C-terminal domain. We did not observe this mutation in both parents of the PJS patient. Therefore, it is considered a novel de novo mutation. CONCLUSION: The results presented herein enlarge the spectrum of mutations of the STK11 gene by identifying a novel de novo mutation in a PJS patient and further support the hypothesis that STK11 mutations are disease-causing mutations for PJS with or without a positive family history
Adjacent Segment Pathology after Anterior Cervical Fusion
Anterior cervical fusion has become a standard of care for numerous pathologic conditions of the cervical spine. However, subsequent development of clinically significant disc disease at levels adjacent to fused discs is a serious long-term complication of this procedure. As more patients live longer after surgery, it is foreseeable that adjacent segment pathology (ASP) will develop in increasing numbers of patients. Also, ASP has been studied more intensively with the recent popularity of motion preservation technologies like total disc arthroplasty. The true nature and scope of ASP remains poorly understood. The etiology of ASP is most likely multifactorial. Various factors including altered biomechanical stresses, surgical disruption of soft tissue and the natural history of cervical disc disease contribute to the development of ASP. General factors associated with disc degeneration including gender, age, smoking and sports may play a role in the development of ASP. Postoperative sagittal alignment and type of surgery are also considered potential causes of ASP. Therefore, a spine surgeon must be particularly careful to avoid unnecessary disruption of the musculoligamentous structures, reduced risk of direct injury to the disc during dissection and maintain a safe margin between the plate edge and adjacent vertebrae during anterior cervical fusion
The C-terminal region of Bfl-1 sensitizes non-small cell lung cancer to gemcitabine-induced apoptosis by suppressing NF-κB activity and down-regulating Bfl-1
Gemcitabine is used to treat several cancers including lung cancer. However, tumor cells often escape gemcitabine-induced cell death via various mechanisms, which include modulating bcl-2 family members and NF-κB activation. We previously reported that the C-terminal region of Bfl-1 fused with GFP (BC) is sufficient to induce apoptosis in 293T cells. In the present study, we investigated the anti-tumor effect of combined BC gene therapy and gemcitabine chemotherapy in vitro and in vivo using non-small cell lung cancer cell lines and a xenograft model. Cell lines were resistant to low dose gemcitabine (4-40 ng/ml), which induced NF-κB activation and concomitant up-regulation of Bfl-1 (an NF-κB-regulated anti-apoptotic protein). BC induced the apoptosis of A549 and H157 cells with caspase-3 activation. Furthermore, co-treatment with BC and low dose gemcitabine synergistically and efficiently induced mitochondria-mediated apoptosis in these cells. When administered alone or with low dose gemcitabine, BC suppressed NF-κB activity, inhibited the nuclear translocation of p65/relA, and down-regulated Bfl-1 expression. Furthermore, direct suppression of Bfl-1 by RNA interference sensitized cells to gemcitabine-induced cell death, suggesting that Bfl-1 importantly regulates lung cancer cell sensitivity to gemcitabine. BC and gemcitabine co-treatment also showed a strong anti-tumor effect in a nude mouse/A549 xenograft model. These results suggest that lung cancer cells become resistant to gemcitabine via NF-κB activation and the subsequent overexpression of Bfl-1, and that BC, which has both pro-apoptotic and NF-κB inhibitory effects, could be harnessed as a gene therapy to complement gemcitabine chemotherapy in non-small cell lung cancer
Crystal structure of hyperthermophilic esterase EstE1 and the relationship between its dimerization and thermostability properties
<p>Abstract</p> <p>Background</p> <p>EstE1 is a hyperthermophilic esterase belonging to the hormone-sensitive lipase family and was originally isolated by functional screening of a metagenomic library constructed from a thermal environmental sample. Dimers and oligomers may have been evolutionally selected in thermophiles because intersubunit interactions can confer thermostability on the proteins. The molecular mechanisms of thermostabilization of this extremely thermostable esterase are not well understood due to the lack of structural information.</p> <p>Results</p> <p>Here we report for the first time the 2.1-Å resolution crystal structure of EstE1. The three-dimensional structure of EstE1 exhibits a classic α/β hydrolase fold with a central parallel-stranded beta sheet surrounded by alpha helices on both sides. The residues Ser154, Asp251, and His281 form the catalytic triad motif commonly found in other α/β hydrolases. EstE1 exists as a dimer that is formed by hydrophobic interactions and salt bridges. Circular dichroism spectroscopy and heat inactivation kinetic analysis of EstE1 mutants, which were generated by structure-based site-directed mutagenesis of amino acid residues participating in EstE1 dimerization, revealed that hydrophobic interactions through Val274 and Phe276 on the β8 strand of each monomer play a major role in the dimerization of EstE1. In contrast, the intermolecular salt bridges contribute less significantly to the dimerization and thermostability of EstE1.</p> <p>Conclusion</p> <p>Our results suggest that intermolecular hydrophobic interactions are essential for the hyperthermostability of EstE1. The molecular mechanism that allows EstE1 to endure high temperature will provide guideline for rational design of a thermostable esterase/lipase using the lipolytic enzymes showing structural similarity to EstE1.</p
Long-term Results of Primary Total Knee Arthroplasty with and without Patellar Resurfacing
Among patients that underwent total knee arthroplasty from June, 1990 to January, 1999, 61 cases (44 patients) that could be followed for more than 10 years were included in this study. The patients were divided into a patellar retention group and a patellar resurfacing group, and were compared with regard to their clinical and radiological outcomes. In patients undergoing primary TKA, a selective patellar resurfacing protocol was used. The indications for patellar retention were a small patella, nearly normal articular cartilage, minimal preoperative patellofemoral pain, poor patellar bone quality, and young patient age. When patellar retention was performed, osteophytes of the patella were removed and marginal electrocauterization was carried out. There were 25 cases (20 patients) in the patellar retention group and 36 cases (29 patients) in the patellar resurfacing group. The mean follow-up period was 140.7 months in the patellar retention group and 149.0 months in the patellar resurfacing group. The selective patellar resurfacing with total knee arthroplasty had a favorable outcome;there were a significant difference noted between the 2 groups in the functional scores, which showed better outcomes in the patellar resurfacing group than in the patellar retention group
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Carbon-Nanotube Optoacoustic Lens for Focused Ultrasound Generation and High-Precision Targeted Therapy
We demonstrate a new optical approach to generate high-frequency (>15 MHz) and high-amplitude focused ultrasound, which can be used for non-invasive ultrasound therapy. A nano-composite film of carbon nanotubes (CNTs) and elastomeric polymer is formed on concave lenses, and used as an efficient optoacoustic source due to the high optical absorption of the CNTs and rapid heat transfer to the polymer upon excitation by pulsed laser irradiation. The CNT-coated lenses can generate unprecedented optoacoustic pressures of >50 MPa in peak positive on a tight focal spot of 75 μm in lateral and 400 μm in axial widths. This pressure amplitude is remarkably high in this frequency regime, producing pronounced shock effects and non-thermal pulsed cavitation at the focal zone. We demonstrate that the optoacoustic lens can be used for micro-scale ultrasonic fragmentation of solid materials and a single-cell surgery in terms of removing the cells from substrates and neighboring cells
Use of Magnetic Nanoparticles to Visualize Threadlike Structures Inside Lymphatic Vessels of Rats
A novel application of fluorescent magnetic nanoparticles was made to visualize a new tissue which had not been detectable by using simple stereomicroscopes. This unfamiliar threadlike structure inside the lymphatic vessels of rats was demonstrated in vivo by injecting nanoparticles into lymph nodes and applying magnetic fields on the collecting lymph vessels so that the nanoparticles were taken up by the threadlike structures. Confocal laser scanning microscope images of cryosectioned specimens exhibited that the nanoparticles were absorbed more strongly by the threadlike structure than by the lymphatic vessels. Further examination using a transmission electron microscope revealed that the nanoparticles had been captured between the reticular fibers in the extracellular matrix of the threadlike structures. The emerging technology of nanoparticles not only allows the extremely elusive threadlike structures to be visualized but also is expected to provide a magnetically controllable means to investigate their physiological functions
Successful switching from insulin to sulfonylurea in a 3-month-old infant with diabetes due to p.G53D mutation in
Permanent neonatal diabetes mellitus is most commonly caused by mutations in the ATP-sensitive potassium channel (KATP) subunits. Prompt initiation of sulfonylurea treatment can improve glycemic control in children with KCNJ11 mutation. In this report, we present a case of permanent neonatal diabetes caused by a mutation in the KCNJ11 gene that was successfully treated via early switching of insulin to sulfonylurea treatment. A 53-day-old female infant presented with diabetic ketoacidosis. Insulin was administered for the ketoacidosis and blood glucose regulation. At 3 months of age, using genomic DNA extracted from peripheral lymphocytes, direct sequencing of KCNJ11 identified a heterozygous mutation of c.158G>A (p.G53D) and confirmed the diagnosis of permanent neonatal diabetes mellitus. Subsequently, treatment with sulfonylurea was initiated, and the insulin dose was gradually tapered. At 4 months of age, insulin therapy was discontinued, and sulfonylurea (glimepiride, 0.75 mg/kg) was administered alone. At 6 months after initiation of administration of sulfonylurea monotherapy, blood glucose control was stable, and no hypoglycemic events or developmental delays were reported. C-peptide levels increased during treatment with sulfonylurea. Early switching to sulfonylurea in infants with permanent diabetes mellitus owing to a KCNJ11 mutation could successfully help regulate glycemic control, which suggests the need for early genetic testing in patients presenting with diabetes before 6 months of age
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