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Data were retrieved from the Cambrige Structural Database for crystal structures containing metal complexes of ethylenediamine (en), tetramethylethylenediamine (tmeda), bis(dimethylphosphino)ethane (dmpe), bis(diphenyl-phosphino)e...
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Data were retrieved from the Cambrige Structural Database for crystal structures containing metal complexes of ethylenediamine (en), tetramethylethylenediamine (tmeda), bis(dimethylphosphino)ethane (dmpe), bis(diphenyl-phosphino)ethane (dppe) chelate complexes [M(en)(279 structures, 468 fragments), M(tmeda) (156 structures, 181 fragments), M(dmpe) (205 structures, 288 fragments) and M(dppe) (273 structures, 338 fragments)] and fused five-membered chelate ring systems [complexxes of diethylenetriamine, M(dien) (91 structures, 108 fragments), tris(2-aminoethyl)amine, M(nn_3) (49 structures, 54 fragments), tris(2-diphenylphosphinoethyl)]phosphine, M(pp_3), and tris(2-diphenylphosphinoethyl)amine, M(np_3) (54 structures, 56 fragments)], and have been analysed using principal component analysis (PCA) of the intra-ring torsion angles. A limited number of preferred conformers is observed for each system: enantiomeric twist conformations (#delta# or #lambda#) for M(en), M(trmeda), M(dppe) and M(dmpe); three unique conformers: #delta##delta# (and its enantiomer #lambda##lambda#), #lambda##delta# or #delta##lambda# for M(dien); and two types for M(nn_3) or M(xp_3) (x=n or p): two enantiomeric C_3 symmetric A (#lambda##lambda##lambda#,#delta##delta##delta#) and six equivalent B (#delta##lambda##delta#, #delta##delta##lambda#, #lambda##delta##delta#, #delta##lambda##lambda#, #lambda##lambda##lambda##delta#, and #lambda##delta##lambda#) conformers of lower symmetry: The pseudorotation pathway for #delta#<-> #lambda# interconversion in teh single ring systems is clear for M(dppe) and also for M(dmpe) but less so for M(en) and, M(tmeda). The #delta##lambda# and #lambda##delta# comformers of M(dien) apparently interconvert through #delta##delta# (or #lambda##lambda#) intermediates with one ring a time inverting. Similarly the interconversion of conformers in the M(xp_3) and M(nn_3) systems seems likely, on the basis of the distribution of structures in conformation space, to follow a sequence #delta##delta##delta#<->#delta##lambda##delta#<->#lambda##lambda##delta#<->#lambda##lambda##lambda# (or its equivalent) but ont #delta##delta##delta#<->#delta##lambda##delta#<->#lambda##lambda##delta#<->#lambda##lambda##lambda# . In the M(dien), M(nn_3), and M(xp_3) systems the conformation preferred is linked to the metal coordination geometry. In particular, teh presence of an N-M-N angle approaching 180 deg in a mer-octahedral or square-based pyramid stereochemistry in M(dien) species enforces a #delta##lambda# conformation. Similarly, related mer-like stereochemistry in M(nn_3) and M(xp_3) complexes leads to a B-type conformation. Longer M-N (or M-P) distances enforce more puckered, symmetrical, twist conformations of five-membered rings. A new pseudo-principal component analysis method is introduced which allows quantitative comparison of conformations in analogous but not identical ring systems. Conformations in M(en) are compared with M(dien) or M(nn_3), with the single-ring system exhibiting less distorted conformations. Phosphine systems exhibit greater variation of conformation than their amine counterparts. In particular M(dmpe) systems exhibit greater variation of conformation than their amine counterparts. In particular M(dmpe) systems show considerably ore variation than M(tmeda) whereas M(dppe) species are more varied in conformation than are M(dmpe).
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Introduction Pancreatic cancer (PC), even in the absence of metastatic disease, has a dismal prognosis. One-third of them are borderline resectable (BRPC) or locally advanced unresectable PC (LAUPC) at diagnosis. There are limited...
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Introduction Pancreatic cancer (PC), even in the absence of metastatic disease, has a dismal prognosis. One-third of them are borderline resectable (BRPC) or locally advanced unresectable PC (LAUPC) at diagnosis. There are limited prospective data supporting the best approach on these tumours. Neoadjuvant chemotherapy (ChT) is being increasingly used in this setting.Methods This is a retrospective series of consecutive patients staged as BRPC or LAUPC after discussion in the multidisciplinary board (MDB) at an academic centre. All received neoadjuvant ChT, followed by chemoradiation (ChRT) in some cases, and those achieving enough downstaging had a curative-intent surgery. Descriptive data about patient’s characteristics, neoadjuvant treatments, toxicities, curative resections, postoperative complications, pathology reports and adjuvant treatment were collected. Overall survival (OS) and progression-free survival was calculated with Kaplan-Meier method and log-rank test.Results Between August 2011 and July 2019, 49 patients fulfilled the inclusion criteria, and all of them received neoadjuvant ChT. Fluorouracil+folinic?acid, irinotecan and oxaliplatin was the most frequently used scheme (77%). The most prevalent grade 3 or 4 toxicities were neutropenia (26.5%), neurotoxicity (12.2%), diarrhoea (8.2%) and nausea (8.2%). 18 patients (36.7%) received ChRT thereafter. In total, 22 patients (44,9%) became potentially resectable and 19 of them had an R0 or R1 pancreatic resection. One was found to be unresectable at surgery and two refused surgery. A vascular resection was required in 7 (35%). No postoperative deaths were observed. Postoperative ChT was given to 12 (66.7%) of resected patients. Median OS of the whole cohort was 24,9 months (95%?CI 14.1 to 35.7), with 30.6 months for resected and 13.1 months for non-resected patients, respectively (p<0.001).Conclusion A neoadjuvant approach in BRPC and LAUPC was well tolerated and allowed a curative resection in 38.8% of them with a potential improvement on OS.
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Abstract Purpose Several studies demonstrate an increased prevalence and concordance of inflammatory bowel disease among the relatives of patients. Other studies suggest that genetic influence is over-estimated. The aims of this s...
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Abstract Purpose Several studies demonstrate an increased prevalence and concordance of inflammatory bowel disease among the relatives of patients. Other studies suggest that genetic influence is over-estimated. The aims of this study are to evaluate the phenotypic expression and the treatment requirements in familial inflammatory bowel disease, to study the relationship between number of relatives and degree of kinship with disease severity and to quantify the impact of family aggregation compared to other environmental factors. Methods Observational analytical study of 1211 patients followed in our unit. We analyzed, according to the existence of familial association, number and degree of consanguinity, the phenotypic expression, complications, extraintestinal manifestations, treatment requirements, and mortality. A multivariable analysis considering smoking habits and non-steroidal-anti-inflammatory drugs was performed. Results 14.2% of patients had relatives affected. Median age at diagnosis tended to be lower in the familial group, 32 vs 29, p ?=?0.07. In familial ulcerative colitis, there was a higher proportion of extraintestinal manifestations: peripheral arthropathy (OR?=?2.3, p ?=?0.015) and erythema nodosum (OR?=?7.6, p ?=?0.001). In familial Crohn’s disease, there were higher treatment requirements: immunomodulators (OR?=?1.8, p ?=?0.029); biologics (OR?=?1.9, p ?=?0.011); and surgery (OR?=?1.7, p ?=?0.044). The abdominal abscess increased with the number of relatives affected: 5.1% (sporadic), 7.0% (one), and 14.3% (two or more), p =0.039. These associations were maintained in the multivariate analysis. Conclusions Familial aggregation is considered a risk factor for more aggressive disease and higher treatment requirements, a tendency for earlier onset, more abdominal abscess, and extraintestinal manifestations, remaining a risk factor analyzing the influence of some environmental factors.
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The reaction system consisting of copper, saccharinate, and the auxiliary ligands H_2O, PPh_3, and NH_3 produces a sequence of compounds in which saccharinate is coordinated to copper in four distinct manners.
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Background?Caustic ingestion is a potentially severe condition and early identification of poor outcome is essential to improve management; however, prediction based on endoscopy alone can overestimate severity. This study aimed t...
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Background?Caustic ingestion is a potentially severe condition and early identification of poor outcome is essential to improve management; however, prediction based on endoscopy alone can overestimate severity. This study aimed to develop and validate a prognostic score. Methods?A prospective cohort study was designed to include all consecutive patients aged >?15 years who presented with caustic ingestion between 1995 and 2017.?Adverse outcome was defined by intensive care unit admission, urgent surgery, or death. The predictive value of clinical, analytical, and endoscopic variables was assessed in the first cohort (derivation cohort) and a prognostic score based on the resulting risk factors was developed by logistic regression. Internal validation (bootstrapping) was performed and then external validation was checked in an independent sample of patients (validation cohort). Results?469 cases of caustic ingestion were included, 265 in the derivation cohort and 204 in the validation cohort. Ingestion of acidic substances (odds ratio [OR] 3.13, 95?% confidence interval [CI] 2.33?–?4.21), neutrophil count (OR 1.05, 95?%CI 1.04?–?1.06), metabolic acidosis (bicarbonate value, OR 0.82, 95?%CI 0.78?–?0.85), and endoscopic injury (OR 3.81, 95?%CI 3.35?–?4.34) were independent risk factors for poor outcome. The prognostic score based on these variables provided better accuracy than endoscopy alone (P?=?0.04), with high sensitivity, specificity, positive and negative predictive values (93.3?%, 92.7?%, 72.7?%, 98.5?%, respectively), and area under the curve (0.976, 95?%CI 0.973?–?0.979; P?收起
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Objectives The aim of this investigation was to evaluate the pancreatographic findings and dynamics of pancreatic duct diameter, as determined by secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP), in patients ...
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Objectives The aim of this investigation was to evaluate the pancreatographic findings and dynamics of pancreatic duct diameter, as determined by secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP), in patients with acute alcoholic pancreatitis or chronic alcoholic pancreatitis and in a control group. Methods S-MRCP was performed in patients with acute alcoholic pancreatitis who did not manifest the functional and radiological (ultrasonography and computed tomography) criteria of chronic pancreatitis (n = 21), in patients with chronic alcoholic pancreatitis (n = 28) and in a control group (n = 16). The diameter of the main pancreatic duct (MPD) was monitored before secretin administration and at 3 and 10 min after secretin administration. Morphological features were also assessed before and after the administration of secretin. Results All ductal diameters were significantly larger in chronic alcoholic pancreatitis (P < 0.0001). There were no differences in MPD caliber between patients with acute alcoholic pancreatitis and the control group. The percentage of variation between basal MPD diameter and at 3 min post-secretin administration was lower in patients with chronic (35.5%) pancreatitis than in those with acute alcoholic pancreatitis (52.3%) and the control group (52.5%). There were no significant differences between patients with acute alcoholic pancreatitis and the control group in terms of the frequency of visualization of side branches, ductal narrowing, intraluminal filling defects, and ductal irregularity. One patient with acute alcoholic pancreatitis presented ductal criteria of chronic pancreatitis following the administration of secretin. Conclusions The dynamics of MPD visualized on S-MRCP in patients with acute alcoholic pancreatitis is similar to that observed in the control group and different from that observed in patients with chronic alcoholic pancreatitis. There were no significant differences between patients with acute alcoholic pancreatitis and the control group in terms of morphological pancreatographic features.
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The pseudo-octahedral complexes [Mo(η~3-allyl)Br(CO))_2(PPy_nPh_(3-n)-P,N)] (Py = 2-pyridyl; n = 2, 3) and Mo(η~3-allyl)Br(CO))_2(OPPy_mPh_(3-m)-O,N)] (m = 1, 2, 3) undergo three different dynamic processes in solution, dependin...
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The pseudo-octahedral complexes [Mo(η~3-allyl)Br(CO))_2(PPy_nPh_(3-n)-P,N)] (Py = 2-pyridyl; n = 2, 3) and Mo(η~3-allyl)Br(CO))_2(OPPy_mPh_(3-m)-O,N)] (m = 1, 2, 3) undergo three different dynamic processes in solution, depending on the clelating ligand. The complexes containing PPhPy_2 and PPy_3 as chelating P,N-donors undergo a novel "pivoted double switch" mechanism which scrambles two equatorial coordination sites with racemization, while maintaining the identity of the phosphorus atom trans to the allyl ligand. The complexes containing 2-pyridylphosphane oxides as chelating O,N-donors undergo a nondissociative intramolecular trigonal-twist (or turnstile) rearrangement which maintains the identity of the phosphane oxide oxygen atom coordinated in an equatorial position. All the complexes containing uncoordinated pyridyls undergo a slow dissociative exchange of pyridyls without coordination site scrambling. The structure of the complex [Mo(Mo(η~3-allyl)Br(CO)_2(OPPy_3-O,N)] has been determined by X-ray diffraction.
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Objectives This study aimed to compare primary surgical versus nonsurgical treatment in a series of patients with infected pancreatic necrosis (IPN) and to investigate whether the success of nonsurgical ...
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Objectives This study aimed to compare primary surgical versus nonsurgical treatment in a series of patients with infected pancreatic necrosis (IPN) and to investigate whether the success of nonsurgical approach is related to a less severe disease.
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Purpose Use of biosutures in animal models of colonic anastomoses is associated with decreased adhesions without affecting anastomotic strength. This study aimed to evaluate the effect of biosutures on colonic anastomoses kept fre...
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Purpose Use of biosutures in animal models of colonic anastomoses is associated with decreased adhesions without affecting anastomotic strength. This study aimed to evaluate the effect of biosutures on colonic anastomoses kept free of adhesions by peritoneal instillation of icodextrin 4%.
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Background Expanded adipose-derived stem cells (ASC) have been shown to be effective in treating Crohn’s patients with enterocutaneous fistulas. It is possible that unexpanded cells corresponding to the stromal vascular fraction ...
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Background Expanded adipose-derived stem cells (ASC) have been shown to be effective in treating Crohn’s patients with enterocutaneous fistulas. It is possible that unexpanded cells corresponding to the stromal vascular fraction (SVF) may also be effective.
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