266 research outputs found
Editorial : Adult neurogenesis as a regenerative strategy for brain repair
Funding Information: This work was supported by Biological Sciences Research Council (BBSRC) BB/W008068/1 to DB, National Research Foundation of Korea (NRF) (2019R1A2C1003958 and 2021R1A4A5028966) to K-OC, and NIH (R01CA242158 and R01AG058560) to M-HJ.Peer reviewedPublisher PD
Dual quadratic differentials and entire minimal graphs in Heisenberg space
We define holomorphic quadratic differentials for spacelike surfaces with
constant mean curvature in the Lorentzian homogeneous spaces
with isometry group of dimension 4, which are dual to
the Abresch-Rosenberg differentials in the Riemannian counterparts
, and obtain some consequences. On the one hand, we
give a very short proof of the Bernstein problem in Heisenberg space, and
provide a geometric description of the family of entire graphs sharing the same
differential in terms of a 2-parameter conformal deformation. On the other
hand, we prove that entire minimal graphs in Heisenberg space have negative
Gauss curvature.Comment: 19 page
Tissue expression and antibacterial activity of host defense peptides in chicken
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the Creative Commons license, and indicate if changes were made.Abstract
Background
Host defence peptides are a diverse group of small, cationic peptides and are important elements of the first line of defense against pathogens in animals. Expression and functional analysis of host defense peptides has been evaluated in chicken but there are no direct, comprehensive comparisons with all gene family and individual genes.
Results
We examined the expression patterns of all known cathelicidins, β-defensins and NK-lysin in multiple selected tissues from chickens. CATH1 through 3 were predominantly expressed in the bone marrow, whereas CATHB1 was predominant in bursa of Fabricius. The tissue specific pattern of β-defensins generally fell into two groups. β-defensin1-7 expression was predominantly in bone marrow, whereas β-defensin8-10 and β-defensin13 were highly expressed in liver. NK-lysin expression was highest in spleen. We synthesized peptide products of these gene families and analysed their antibacterial efficacy. Most of the host defense peptides showed antibacterial activity against E.coli with dose-dependent efficacy. β-defensin4 and CATH3 displayed the strongest antibacterial activity among all tested chicken HDPs. Microscopic analyses revealed the killing of bacterium by disrupting membranes with peptide treatment.
Conclusions
These results demonstrate dose-dependent antimicrobial effects of chicken HDPs mediated by membrane damage and demonstrate the differential tissue expression pattern of bioactive HDPs in chicken and the relative antimicrobial potency of the peptides they encode
Clinical Impact of Prophylactic Antibiotic Treatment for Self-Expandable Metallic Stent Insertion in Patients with Malignant Colorectal Obstruction
Purpose. The aim of this study was to determine the efficacy of prophylactic antibiotics (PA) for reducing the infectious complications and the potential risk factors responsible for the infectious complications after stent insertion for malignant colorectal obstruction. Methods. We performed a retrospective review of 224 patients who underwent self-expandable metallic stent (SEMS) insertion for malignant colorectal obstruction from May 2004 to December 2012. Results. There were 145 patients in the PA group and 79 in non-PA group. The CRP level in PA group was significantly higher than that in non-PA. Abdominal tenderness and mechanical ileus were significantly more frequent in PA group than those in non-PA. The frequency of post-SEMS insertion fever, systemic inflammatory response syndrome (SIRS), and bacteremia was not significantly different between PA and non-PA groups. In multivariate analysis, the CRP level was risk factor related to post-SEMS insertion SIRS. However, in propensity score matching analysis, there was no independent risk factor related to post-SEMS insertion fever, SIRS, and bacteremia. Conclusion. The use of PA in patients with malignant colorectal obstruction may be not effective to prevent the development of infectious complications after SEMS insertion
Effects of a single nucleotide polymorphism in the chicken NK-lysin gene on antimicrobial activity and cytotoxicity of cancer cells
NK-lysin is an effector protein of the innate immune system and an important component of host protection. We isolated a SNP in the NK-lysin coding sequence among different chicken breeds. This A to G substitution at the position 271 nucleotide in the ORF results in an Asn (N) to Asp (D) amino acid alteration. We synthesized two 30-aa peptides (N29N and N29D) to compare the biological activity of the helix 2-loop-helix 3 region of NK-lysin resulting from the polymorphic gene. Both peptides were found to be cytotoxic in bacteria and tumor cell cultures at micromolar concentrations. The N29N peptide, however, exhibited greater antibacterial and anticancer activity than the N29D peptide. Circular dichroism spectroscopy of the two peptides in negatively charged single unilamellar vesicles showed spectra typical of α-helical peptides. The helical profile of N29D was reduced substantially compared with that of N29N. However, no structural change was observed in neutral vesicles. ζ-Potential measurements of liposomes incubated with increasing peptide concentrations allowed surface charge neutralization with a negatively charged lipid, but not with a zwitterionic lipid. This result suggests that a difference in electrostatic interaction between lipid membranes and the helical peptides results from the polymorphic gene and is subsequently an important factor in cell lytic activity of variant NK-lysin peptides
Plant cell culture strategies for the production of natural products
Plants have evolved a vast chemical cornucopia to support their sessile lifestyles. Man has exploited this natural resource since Neolithic times and currently plant-derived chemicals are exploited for a myriad of applications. However, plant sources of most high-value natural products (NPs) are not domesticated and therefore their production cannot be undertaken on an agricultural scale. Further, these plant species are often slow growing, their populations limiting, the concentration of the target molecule highly variable and routinely present at extremely low concentrations. Plant cell and organ culture constitutes a sustainable, controllable and environmentally friendly tool for the industrial production of plant NPs. Further, advances in cell line selection, biotransformation, product secretion, cell permeabilisation, extraction and scale-up, among others, are driving increases in plant NP yields. However, there remain significant obstacles to the commercial synthesis of high-value chemicals from these sources. The relatively recent isolation, culturing and characterisation of cambial meristematic cells (CMCs), provides an emerging platform to circumvent many of these potential difficulties. [BMB Reports 2016; 49(3): 149-158
Comparison of Clinico-Radiological Features between Congenital Cystic Neuroblastoma and Neonatal Adrenal Hemorrhagic Pseudocyst
OBJECTIVE: To evaluate the radiological and clinical findings of congenital cystic neuroblastomas as compared with those of the cystic presentation of neonatal adrenal hemorrhage.
MATERIALS AND METHODS: We analyzed the US (n = 52), CT (n = 24), and MR (n = 4) images as well as the medical records of 28 patients harboring congenital cystic neuroblastomas (n = 16) and neonatal adrenal hemorrhagic pseudocysts (n = 14). The history of prenatal detection, location, size, presence of outer wall enhancement, internal septations, solid portion, calcification, turbidity, vascular flow on a Doppler examination, and evolution patterns were compared in two groups of cystic lesions, by Fischer's exact test.
RESULTS: All (100%) neuroblastomas and three (21%) of the 14 hemorrhagic pseudocysts were detected prenatally. Both groups of cystic lesions occurred more frequently on the right side; 11 of 16 (69%) for neuroblastomas and 11 of 14 (79%) for hemorrhagic pseudocysts. The size, presence of solid portion, septum, enhancement, and turbidity did not differ significantly (p > 0.05) between the two groups of cystic lesions. However, tiny calcifications (n = 3) and vascular flow on color Doppler US (n = 3) were noted in only neuroblastomas. The cystic neuroblastomas became complex solid and cystic masses, and did not disappear for up to 90 days in the three following cases, whereas 11 of the 14 (79%) hemorrhagic pseudocysts disappeared completely and the three remaining (27%) evolved to calcifications only.
CONCLUSION: Although the imaging findings of two groups of cystic lesions were similar, prenatal detection, the presence of calcification on initial images, vascularity on color Doppler US, and evolution to a more complex mass may all favor neuroblastomasope
Endovascular Stent in Traumatic Thoracic Aortic Dissection
Traumatic thoracic aortic injury is typically fatal. However, recent improvements in pre-hospital care and diagnostic modalities have resulted in an increased number of patients with traumatic aortic injury arriving alive at the hospital. Also, the morbidity and mortality associated with endovascular repair are significantly lower than with conventional open surgery in traumatic thoracic aorta injury. We experienced two cases of successful management of traumatic thoracic aortic dissection with endovascular stents caused by traffic accidents
Liver dysfunction induced by systemic hypersensitivity reaction to lamotrigine: case report
Lamotrigine is an anticonvulsant drug used to treat partial and generalized seizure disorders. Hypersensitivity to lamotrigine usually causes mild symptoms such as fever, rash, and slight invasion of internal organs. However, a 33-year-old male patient who was admitted with Stevens-Johnson syndrome after taking lamotrigine for 15 days experienced hepatic failure and died 5 days after admission. This case demonstrates the importance of realizing that lamotrigine can lead to fatal hepatic failure, and that tests for the normal liver function should be performed when administering lamotrigine
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