1,721,164 research outputs found
Repeat laparoscopic hepatectomy for recurrent tumors is safe and feasible. An Invited Commentary on "Perioperative outcomes comparing laparoscopic with open repeat liver resection for post-hepatectomy recurrent liver cancer: a systematic review and meta-analysis" (Int J Surg 2020; Epub ahead of print)
Full text linkProphylactic drains in totally laparoscopic distal gastrectomy: Are they always necessary?
No full textprophylactic drains have always been a useful tool to detect early complications and prevent postoperative fluid collections, particularly in gastrointestinal surgery. recently, the utilization of such drains has been debated, due to mounting evidence that they could be harmful rather than beneficial. based on recent published articles, liu et al reported that the routine use of prophylactic drains in total laparoscopic distal gastrectomy might not be necessary for all patients. herein, we express our opinion regarding this interesting publication
Using a weaning immunosuppression protocol in liver transplantation recipients with hepatocellular carcinoma: A compromise between the risk of recurrence and the risk of rejection?
Full text linkHepatocellular carcinoma (HCC) recurrence rate after liver transplantation (LT) is still up to 1520%, despite a careful selection of candidates and optimization of the management within the waiting list. To reduce tumour recurrence, the currently adopted post-transplant strategies are based on the administration of a tailored immunosuppression (IS) regimen. Drug-induced depression of the immune system is essential in preventing graft rejection, however has a well-established association with oncogenesis. The immune system has a key role as a defending mechanism against cancer development, preventing vascular invasion and metastasis. Thus, IS drugs represent one of few modifiable non-oncological risk factors for tumour recurrence. In HCC recipients, a tailored IS therapy, with the aim to minimize drugs' doses, is essential to gain the optimal balance between the risk of rejection and the risk of tumour recurrence. So far, a complete withdrawal of IS drugs after LT is reported to be safely achievable in 25% of patients (defined as "operational tolerant"), without the risk of patient and graft loss. The recent identification of non-invasive "bio-markers of tolerance", which permit to identify patients who could successfully withdraw IS therapies, opens new perspectives in the management of HCC after LT. IS withdrawal could potentially reduce the risk of tumour recurrence, which represents the major drawback in HCC recipients. Herein, we review the current literature on IS weaning in patients who underwent LT for HCC as primary indication and we report the largest experiences on IS withdrawal in HCC recipients
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Cytosine to uracil conversion through hydrolytic deamination of cytidine monophosphate hydroxy-alkylated on the amino group: a liquid chromatography – electrospray ionization – mass spectrometry investigation.
No full textA novel pathway for cytosine to uracil conversion performed in a micellar environment, leading to the generation of uridine
monophosphate (UMP), was evidenced during the alkylation reaction of cytidine monophosphate (CMP) by dodecyl epoxide.
Liquid chromatography-electrospray ionization – ion trap - mass spectrometry was used to separate and identify the reaction
products and to follow their formation over time. The detection of hydroxy-amino-dodecane, concurrently with free UMP, in
the reaction mixture suggested that, among the various alkyl-derivatives formed, CMP alkylated on the amino group of
cytosine could undergo tautomerization to an imine and hydrolytic deamination, generating UMP. Interestingly, no evidence
for this peculiar conversion pathway was obtained when guanosine monophosphate (GMP), the complementary ribonucleotide
of CMP, was also present in the reaction mixture, due to the fact that NH2-alkylated CMP was not formed in this case. The last
finding emphasized the role played by CMP–GMP molecular interactions, mediated by a micellar environment, in hindering the
alkylation reaction at the level of the cytosine amino group
Alkylation of complementary ribonucleotides by 1,2-dodecyl-epoxide in a micellar environment: a liquid chromatography – electrospray ionization – sequential mass spectrometry investigation
No full textAlkylation of a pair of complementary ribonucleotides, adenosine monophosphate (AMP) and uridine monophosphate (UMP), was accomplished by 1,2-dodecyl-epoxide (DE) in a oil-in-water microemulsion based on the cationic surfactant Cetyl-trimethylammonium-bromide, providing a suitable catalytic interface for the reagents. Several, often isomeric, alkylation products, bearing one or two hydroxy-dodecyl moieties on their structures, were identified in the reaction mixtures by high-performance liquid chromatography coupled to electrospray ionization ion trap mass spectrometry. In particular, mass spectrometry (MS)/MS spectra, implemented by extracted ion chromatograms obtained for peculiar MS/MS product ions, indicated alkylation to occur on uracil and on uracil/phosphate OH groups in singly and doubly alkylated LIMP, respectively. Adenine NH(2) group and phosphate or ribose OH groups were found to be involved as such (single alkylation) or in combination, in the case of alkylated derivatives of AMP. The reaction of both endocyclic N and C=O groups (tautomerized to C-OH groups) of uracil and the predominance of nucleophilic attack to the more accessible carbon of the DE epoxydic bridge (the only exception being the reaction by the NH(2) group of adenine) were inferred from MS(3) spectra with the help of extracted ion chromatograms for specific fragment ions, after their structural characterization. Interestingly, alkylation on one of the uracil C=O groups and, partially, on the adenine NH(2) group, both potentially involved in AMP/UMP base pairing in the micellar environment, were found to be hindered when both ribonucleotides were present in the reaction mixtures
Surfactant curvilinear diffusion in giant wormlike micelles
No full textWe present the first experimental measurements of surfactant curvilinear diffusion in giant wormlike micelles. The surfactant diffusion was monitored by pulsed field gradient NMR for various observation times t ranging from 0.020 to 1.5 s. The surfactant mean-square displacement was found to scale as t(1/2). A model of lateral diffusion along wormlike micellar aggregates with Gaussian statistics is found to describe the echo attenuation well. This type of diffusion is analogous to polymer segment diffusion in the tube-reptation model
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