1,231 research outputs found

    Modulation of NKG2D expression in human CD8(+) T cells corresponding with tuberculosis drug cure.

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    BACKGROUND: Biomarkers predicting tuberculosis treatment response and cure would facilitate drug development. This study investigated expression patterns of the co-stimulation molecule NKG2D in human tuberculosis and treatment to determine its potential usefulness as a host biomarker of tuberculosis drug efficacy. METHODS: Tuberculosis patients (n = 26) were recruited in Lahore, Pakistan, at diagnosis and followed up during treatment. Household contacts (n = 24) were also recruited. NKG2D expression was measured by qRT-PCR in RNA samples both ex vivo and following overnight mycobacterial stimulation in vitro. Protein expression of NKG2D and granzyme B was measured by flow cytometry. RESULTS: NKG2D expression in newly diagnosed tuberculosis patients was similar to household contacts in ex vivo RNA, but was higher following in vitro stimulation. The NKG2D expression was dramatically reduced by intensive phase chemotherapy, in both ex vivo blood RNA and CD8(+) T cell protein expression, but then reverted to higher levels after the continuation phase in successfully treated patients. CONCLUSION: The changes in NKG2D expression through successful treatment reflect modulation of the peripheral cytotoxic T cell response. This likely reflects firstly in vivo stimulation by live Mycobacterium tuberculosis, followed by the response to dead bacilli, antigen-release and finally immunopathology resolution. Such changes in host peripheral gene expression, alongside clinical and microbiological indices, could be developed into a biosignature of tuberculosis drug-induced cure to be used in future clinical trials

    Parallel analysis of ribonucleotide-dependent deletions produced by yeast Top1 in vitro and in vivo

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    Ribonucleotides are the most abundant non-canonical component of yeast genomic DNA and their persistence is associated with a distinctive mutation signature characterized by deletion of a single repeat unit from a short tandem repeat. These deletion events are dependent on DNA topoisomerase I (Top1) and are initiated by Top1 incision at the relevant ribonucleotide 3′-phosphodiester. A requirement for the re-ligation activity of Top1 led us to propose a sequential cleavage model for Top1-dependent mutagenesis at ribonucleotides. Here, we test key features of this model via parallel in vitro and in vivo analyses. We find that the distance between two Top1 cleavage sites determines the deletion size and that this distance is inversely related to the deletion frequency. Following the creation of a gap by two Top1 cleavage events, the tandem repeat provides complementarity that promotes realignment to a nick and subsequent Top1-mediated ligation. Complementarity downstream of the gap promotes deletion formation more effectively than does complementarity upstream of the gap, consistent with constraints to realignment of the strand to which Top1 is covalently bound. Our data fortify sequential Top1 cleavage as the mechanism for ribonucleotide-dependent deletions and provide new insight into the component steps of this process

    Nonflammable Lithium Metal Full Cells with Ultra-high Energy Density Based on Coordinated Carbonate Electrolytes

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    Coupling thin Li metal anodes with high-capacity/high-voltage cathodes such as LiNi0.8Co0.1Mn0.1O2 (NCM811) is a promising way to increase lithium battery energy density. Yet, the realization of high-performance full cells remains a formidable challenge. Here, we demonstrate a new class of highly coordinated, nonflammable carbonate electrolytes based on lithium bis(fluorosulfonyl)imide (UFSI) in propylene carbonate/fluoroethylene carbonate mixtures. Utilizing an optimal salt concentr ation (4 M LiFSI) of the electrolyte results in a unique coordination structure of Li+-FSI-solvent cluster, which is critical for enabling the formation of stable interfaces on both the thin Li metal anode and high-voltage NCM811 cathode. Under highly demanding cell configuration and operating conditions (Li metal anode = 35 mu m, areal capacity/charge voltage of NCM811 cathode = 4.8 mAh cm(-2)/4 .6 V, and anode excess capacity [relative to the cathode] = 0.83), the Li metal-based full cell provides exceptional electrochemical performance (energy densities = 679 Wh kg(cell)(-1)/1,024 Wh L-cell(-1)) coupled with nonflammability

    Initial serum sodium concentration determines the decrease in sodium level after terlipressin administration in patients with liver cirrhosis

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    BACKGROUND: Terlipressin, as a prodrug of vasopressin, has agonistic effects on the V1 receptor and partial agonistic effects on renal vasopressin V2 receptors. However, its effects on serum sodium concentration are controversial. METHODS: This study retrospectively investigated 127 patients with liver cirrhosis to examine the incidence and risk factors for the decrease in serum sodium level following terlipressin administration. RESULTS: Terlipressin was prescribed for bleeding control (99) and management of hepatorenal syndrome (28). Serum sodium level decreased from 134.0 ± 6.5 mmol/L to 130.4 ± 6.2 mmol/L during or after terlipressin treatment (P < 0.001) in all patients. In 45 patients (35.4%), the serum sodium concentration decreased by > 5 mmol/L, in 29 patients (22.8%); by 5–10 mmol/L; and in 16 patients (12.6%), by > 10 mmol/L. Five patients in the latter group showed neurological manifestations. In the univariate analysis, several factors including age, purpose of use, serum creatinine, and Model for End-Stage Liver Disease score, representing liver function, were significantly associated with the decrease in serum sodium after terlipressin administration. However, a multivariate analysis revealed that only initial sodium level was the most powerful predictor of terlipressin-induced reduction in serum sodium. CONCLUSION: An acute reduction in serum sodium concentration was not uncommon during terlipressin treatment, and the baseline serum sodium level was closely related to the reduction in serum sodium concentration

    Crowned dens syndrome as a rare cause of anterior neck pain after transurethral resection of the prostate: a case report

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    We describe the case of a 79-year-old man who presented with progressive aggravation of severe axial neck pain and fever 3 days after transurethral resection of the prostate (TURP), despite maintaining neutral neck posture during surgery. Laboratory examination revealed markedly elevated C-reactive protein levels and erythrocyte sedimentation rates. Computed tomography revealed crown-like calcifications surrounding the odontoid process. We diagnosed crowned dens syndrome (CDS) as the cause of acute-onset neck pain after TURP. The patient was treated with nonsteroidal anti-inflammatory drugs for 5 days, and his symptoms resolved completely. CDS is a rare disease characterized by calcific deposits around the odontoid process with acute onset of severe neck pain and restricted motion. Evidence of inflammation on serological testing and fever are typical of CDS. However, the prevalence and pathophysiology of CDS remain unclear. We hypothesized that systemic inflammation after prostate surgery may have induced a local inflammatory response involving calcification around the odontoid process

    A Case of Small Bowel Obstruction Due to a Paracecal Hernia

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    Internal hernias are rare causes of small bowel obstruction, and one such internal hernia is the paracecal hernia. We report a case of a small bowel obstruction related to a paracecal hernia in which a preoperative diagnosis was made on computed tomography. A laparotomy was performed for definitive diagnosis and treatment. The surgery achieved a good outcome

    Modeling and Re-Engineering of \u3cem\u3eAzotobacter vinelandii\u3c/em\u3e Alginate Lyase to Enhance Its Catalytic Efficiency for Accelerating Biofilm Degradation

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    Alginate is known to prevent elimination of Pseudomonas aeruginosa biofilms. Alginate lyase (AlgL) might therefore facilitate treatment of Pseudomonas aeruginosa-infected cystic fibrosis patients. However, the catalytic activity of wild-type AlgL is not sufficiently high. Therefore, molecular modeling and site-directed mutagenesis of AlgL might assist in enzyme engineering for therapeutic development. AlgL, isolated from Azotobacter vinelandii, catalyzes depolymerization of alginate via a β-elimination reaction. AlgL was modeled based on the crystal structure template of Sphingomonas AlgL species A1-III. Based on this computational analysis, AlgL was subjected to site-directed mutagenesis to improve its catalytic activity. The kcat/Km of the K194E mutant showed a nearly 5-fold increase against the acetylated alginate substrate, as compared to the wild-type. Double and triple mutants (K194E/K245D, K245D/K319A, K194E/K245D/E312D, and K194E/K245D/K319A) were also prepared. The most potent mutant was observed to be K194E/K245D/K319A, which has a 10-fold improved kcat value (against acetylated alginate) compared to the wild-type enzyme. The antibiofilm effect of both AlgL forms was identified in combination with piperacillin/tazobactam (PT) and the disruption effect was significantly higher in mutant AlgL combined with PT than wild-type AlgL. However, for both the wild-type and K194E/K245D/K319A mutant, the use of the AlgL enzyme alone did not show significant antibiofilm effect

    Post-mortem re-cloning of a transgenic red fluorescent protein dog

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    Recently, the world's first transgenic dogs were produced by somatic cell nuclear transfer. However, cellular senescence is a major limiting factor for producing more advanced transgenic dogs. To overcome this obstacle, we rejuvenated transgenic cells using a re-cloning technique. Fibroblasts from post-mortem red fluorescent protein (RFP) dog were reconstructed with in vivo matured oocytes and transferred into 10 surrogate dogs. One puppy was produced and confirmed as a re-cloned dog. Although the puppy was lost during birth, we successfully established a rejuvenated fibroblast cell line from this animal. The cell line was found to stably express RFP and is ready for additional genetic modification
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