Glassy Magnetic Behavior and Correlation Length in Nanogranular Fe-Oxide and Au/Fe-Oxide Samples.

In nanoscale magnetic systems, the possible coexistence of structural disorder and competing magnetic interactions may determine the appearance of a glassy magnetic behavior, implying the onset of a low-temperature disordered collective state of frozen magnetic moments. This phenomenology is the object of an intense research activity, stimulated by a fundamental scientific interest and by the need to clarify how disordered magnetism effects may affect the performance of magnetic devices (e.g., sensors and data storage media). We report the results of a magnetic study that aims to broaden the basic knowledge of glassy magnetic systems and concerns the comparison between two samples, prepared by a polyol method. The first can be described as a nanogranular spinel Fe-oxide phase composed of ultrafine nanocrystallites (size of the order of 1 nm); in the second, the Fe-oxide phase incorporated non-magnetic Au nanoparticles (10-20 nm in size). In both samples, the Fe-oxide phase exhibits a glassy magnetic behavior and the nanocrystallite moments undergo a very similar freezing process. However, in the frozen regime, the Au/Fe-oxide composite sample is magnetically softer. This effect is explained by considering that the Au nanoparticles constitute physical constraints that limit the length of magnetic correlation between the frozen Fe-oxide moments.

Multicentre observational cohort study of implementation and outcomes of laparoscopic distal pancreatectomy.

BACKGROUND: Laparoscopic distal pancreatectomy (LDP) is increasingly being performed as an alternative to open surgery. Whether the implementation and corresponding learning curve of LDP have an impact on patient outcome is unknown. The aim was to investigate the temporal trends in practice across UK centres. METHODS: This was a retrospective multicentre observational cohort study of LDP in 11 tertiary referral centres in the UK between 2006 and 2016. The learning curve was analysed by pooling data for the first 15 consecutive patients who had LDP and examining trends in surgical outcomes in subsequent patients. RESULTS: In total, 570 patients underwent LDP, whereas 888 underwent open resection. For LDP the median duration of operation was 240 min, with 200 ml blood loss. The conversion rate was 12·1 per cent. Neuroendocrine tumours (26·7 per cent) and mucinous cystic neoplasms (19·7 per cent) were commonest indications. The proportion of LDPs increased from 24·4 per cent in 2006-2009 (P1) to 46·0 per cent in 2014-2016 (P3) (P < 0·001). LDP was increasingly performed for patients aged 70 years or more (16 per cent in P1 versus 34·4 per cent in P3; P = 0·002), pancreatic ductal adenocarcinoma (6 versus 19·1 per cent; P = 0·005) and advanced malignant tumours (27 versus 52 per cent; P = 0·016). With increasing experience, there was a trend for a decrease in blood transfusion rate (14·1 per cent for procedures 1-15 to 3·5 per cent for procedures 46-75; P = 0·008), ICU admissions (32·7 to 19·2 per cent; P = 0·021) and median duration of hospital stay (7 (i.q.r. 5-9) to 6 (4-7) days; P = 0·002). After 30 procedures, a decrease was noted in rates of both overall morbidity (57·7 versus 42·2 per cent for procedures 16-30 versus 46-75 respectively; P = 0·009) and severe morbidity (18·8 versus 9·7 per cent; P = 0·031). CONCLUSION: LDP has increased as a treatment option for lesions of the distal pancreas as indications for the procedure have expanded. Perioperative outcomes improved with the number of procedures performed.

ANTECEDENTES: Cada día se utiliza más la pancreatectomía distal laparoscópica (laparoscopic distal pancreatectomy, LDP) como una alternativa a la cirugía abierta. Se desconoce si la implementación y la correspondiente curva de aprendizaje de la LDP tienen impacto en los resultados. El objetivo fue investigar las tendencias relacionadas con su implementación en los centros del Reino Unido a los largo del tiempo. MÉTODOS: Se realizó el estudio observacional retrospectivo y multicéntrico de una cohorte de LDP en once centros de referencia terciarios del Reino Unido entre 2006-2016. Se analizó la curva de aprendizaje agrupando los 15 primeros pacientes consecutivos de LDP y se compararon los resultados quirúrgicos con los obtenidos en los pacientes subsiguientes. RESULTADOS: En total, se incluyeron 570 pacientes con LDP y 888 con resección abierta. Para el LDP, la mediana de tiempo operatorio fue de 240 minutos con 200 ml de pérdida de sangre. La tasa de conversión fue del 12,2%. Las indicaciones más frecuentes fueron los tumores neuroendocrinos (26,7%) y las neoplasias quísticas mucinosas (19,7%). La proporción de LDP aumentó del 24% al 46% (de 2006-2009 a 2014-2016; P < 0,001). La LDP se realizó cada vez con mayor frecuencia en pacientes de ≥ 70 años (15,8% versus 34,4%, P = 0,002), en pacientes con adenocarcinoma ductal pancreático (6,5% versus 19,1%, P = 0,005) y en pacientes con tumores malignos avanzados (27,3% versus 51,85%, P = 0,016). Con el aumento de la experiencia, disminuyeron las tendencias de la tasa de transfusión sanguínea (14,1% al 3,5%, P = 0,008), los ingresos en la UCI (32,7% a 19,2%, P = 0.021) y la mediana de la duración de la estancia hospitalaria (7 (rango intercuartílico 5-9) a 6 (rango intercuartilico 4-7) días, P = 0,002). Tras 30 procedimientos, disminuyeron tanto la morbilidad global (57,7% versus 42,2%, P = 0,009) como las tasas de morbilidad grave (21,5% versus 14,6%, P = 0,022). CONCLUSIÓN: La pancreatectomía distal laparoscópica se ha incrementado como una opción de tratamiento para las lesiones del páncreas distal a medida que se han ido ampliando las indicaciones del procedimiento. Los resultados perioperatorios mejoran con el número de procedimientos realizados.

The effect of non-steroidal anti-inflammatory drugs on severity of acute pancreatitis and pancreatic necrosis.

Introduction Acute pancreatitis (AP) is a common emergency presentation and can be disabling. There is significant morbidity and mortality associated with AP, and it places a considerable burden on the healthcare system. Non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to have a protective effect in some elective contexts. This retrospective study aimed to evaluate the effect of NSAIDs on the course of AP and the severity of the disease. Methods A retrospective analysis was carried out of 324 patients admitted as an emergency with a diagnosis of AP to two UK hospitals. Patients were divided into two groups: those already taking NSAIDs for other co-morbidities and those not taking NSAIDs. Variables compared included: admission to a high dependency or intensive care unit; pancreatic necrosis; pseudocyst development; need for surgery; serum inflammatory markers; modified early warning scores on days 1, 3 and 5; length of stay; and mortality. Results Patients not taking NSAIDs were more likely to have a C-reactive protein level of ≥150mg/l (p=0.007). Patients in the NSAID group experienced less pancreatic necrosis (p=0.019) and lower rates of pseudocyst formation (p=0.010). Other variables showed no difference between the two groups, specifically length of stay and mortality. Conclusions Routine NSAID use may exert a protective effect on the development of AP, its severity, and complications. Therapeutic use of NSAIDs in acute presentations with pancreatitis should be further evaluated.

Elevated preoperative recipient neutrophil-lymphocyte ratio is associated with delayed graft function following kidney transplantation.

INTRODUCTION: The neutrophil-lymphocyte ratio (NLR) is an indicator of inflammatory status. We studied the effect of preoperative elevated NLR in the recipient in relation to the risk of developing delayed graft function (DGF) after kidney transplantation. METHODS: We retrospectively analysed the preoperative white blood cell count of renal transplant recipients between 2003 and 2005. An NLR >3.5 was considered elevated. There were 398 kidney transplant recipients of whom 249 received organs from donors after brain death (DBD), 61 from donors after circulatory death (DCD), and 88 from living donors. RESULTS: One hundred three patients (26%) developed DGF, of which 67 (65%) had NLRs >3.5. Of 295 recipients with primary graft function, only 44 (15%) had elevated NLR. Univariate analysis revealed three factors that significantly influenced graft function: NLR >3.5, cold ischemic time (CIT) >15 hours, and donor type. On multivariate analysis, both donor type (DCD: hazard ratio [HR] = 2.421, confidence interval [CI] = 1.195-4.905, P = .014; LD: HR = 0.289, CI = 0.099-0.846, P = .024) and NLR (HR = 10.673, CI = 6.151-18.518, P < .0001) remained significant. CONCLUSIONS: Elevated recipient preoperative NLR could contribute to increase the risk of developing DGF, which appears to be more pronounced in patients receiving grafts from living donors.

Systematic review: the prognostic role of alpha-fetoprotein following liver transplantation for hepatocellular carcinoma.

BACKGROUND: Liver transplantation (LT) offers a possible cure for carefully selected patients with hepatocellular carcinoma (HCC). Studies report that preoperative alpha-fetoprotein (AFP) is a prognostic indicator that can predict survival and recurrence in these patients. AIM: To undertake a systematic review of available literature on preoperative AFP as a predictor of survival and recurrence following LT for HCC. METHODS: A literature search was performed using Medline, Embase, Cochrane Library, CINAHL and Google scholar databases to identify studies reporting AFP as a prognostic marker in LT for HCC. Primary outcomes of interest were overall survival and recurrence. Secondary outcomes were correlation of pre-LT AFP with vascular invasion and grade of tumour differentiation. RESULTS: A total of 13 studies met the inclusion criteria (12,159 patients). The majority were male (9603, 78.9%). All were observational studies and only one prospective. Methodological quality was rated as poor for all studies, with selection and observer bias apparent for most cohorts. Reported survival rates and recurrence rates varied widely between the studies although overall demonstrated better outcomes for those with lower (<1000 ng/mL) pre-LT AFP levels. Similarly, rates of vascular invasion and poor tumour differentiation were higher in those with high pre-LT AFP levels. CONCLUSIONS: A quantity of AFP >1000 ng/mL is associated with poorer outcomes from liver transplantation for hepatocellular carcinoma. The quality of studies was generally poor and precluded valid statistical meta-analysis. There is a need to improve the performance and reporting of primary prognostic studies to facilitate high quality systematic review and meta-analysis.

Morphologic, immunophenotypic and in vitro growth characteristics of blood and bone marrow associated with stem cell mobilisation in patients with lymphoma.

The proportion of CD34+ cells in the bone marrow (BM) is predictive of the size of progenitor cell mobilisation into the blood (PB). To investigate which other PB and BM parameters may be related to mobilisation, we analysed at steady state PB and BM of 23 patients with relapsed or resistant lymphoma before administering high-dose cyclophosphamide and G-CSF Cell morphology, number of CD34+ cells, and growth in clonogenic assay and in long-term cultures (LTC) were determined and then correlated with mobilisation extent (CD34+ and GM-CFC) and quality (growth of harvested cells in LTC). We found that the good mobilising patients (CD34 > 50 x 10(3)/ml, n=10) had several baseline BM characteristics (number of CD34+ MNC, GM-CFC, BFU-E, production of CFCs in LTC) similar to a group of 12 healthy controls, while patients with reduced mobilisation (CD34 < 50 x 10(3)/ml, n=13) had clearly reduced BM progenitors and LTC growth (p< 0.05). In a multivariate analysis including baseline clinical, blood and bone marrow characteristics, the most significant PB and BM factors independently associated with a higher number and/or quality of mobilised cells were a higher number of CD34+ and GM-CFC in the BM and a higher baseline haemoglobin, platelet, and CD34+ blood count. The capacity to release progenitor cells into the circulation is therefore not predicted by the distribution of morphologically distinguishable cells, marginally predicted by the BM content of highly undifferentiated cells (growth in long term culture), while it is proportional to the number of BM progenitors (CD34+, GM-CFC and BFU-E).

Ornithine decarboxylase in colonic mucosa from patients with moderate or severe Crohn's disease and ulcerative colitis.

Polyamines, as well as ornithine decarboxylase (ODC), the enzyme involved in their synthesis, were reported to be closely related to cell proliferation. In Crohn's disease and ulcerative colitis, cell destruction and proliferation increase in the active stage. The aim of the present study was to determine the ODC in both involved and uninvolved areas of the colonic mucosa of active Crohn's disease and ulcerative colitis patients. The patients were divided in two groups, owing to the different level of activity (severe or moderate), by means of clinical endoscopy, laboratory, and histology evaluations. Subjects with suspected disease, but endoscopically unconfirmed, were used as controls. In all ulcerative colitis and Crohn's disease patients the ODC values both in involved and uninvolved mucosa were significantly lower than in controls. In severe Crohn's disease ODC was significantly reduced versus moderate Crohn's disease only in affected tissues. In all ulcerative colitis patients (moderate or severe) the ODC was significantly decreased in involved mucosa compared with uninvolved mucosa. Severe ulcerative colitis showed the significantly lowest ODC. We suggest that the significant decrease of ODC in the bowel mucosa is closely related to the severity of the disease. The highest decrease of ODC in ulcerative colitis patients would be due both to the enhanced cell destruction, and to the feed-back from exogenous increased polyamine production (bowel bacteria, cell desquamation). Therefore ODC would be considered a sensitive index of the inflammatory derangement of the mucosa, especially in acute ulcerative colitis. We conclude that this behaviour may result in an enhanced risk of neoplasia.

Distribution of mobilized progenitor cells in the buffy coat of the haemonetics MCS3p cell separator: a study to optimize the collection of progenitors by leukapheresis.

Hematopoietic progenitor and stem cells for transplantation can be mobilized into the circulation and collected by leukapheresis. In this procedure, the leukocytes are distributed in the buffy coat along a density gradient, and the composition of the final product depends on which layer was collected. For the Haemonetics MCS3p Cell Separator, the manufacturer recommended starting the progenitor cell collection at a light transmission of 30%-40% (compared with plasma) and continue it for 40-50 ml. To optimize the use of this machine, the buffy coat it produces was studied in 12 patients by collecting it in fractions of increasing specific weight. Each fraction was analyzed by morphology, immunocytometry, and cell culture. We found that the buffy coat uniformly contains 8 times more leukocytes than blood, but the proportion of each white cell type varies along a gradient. The lymphocyte-predominant lighter layers are richer in CD34+ cells when compared with the granulocyte-predominant denser layers (6-14 times versus 2-4 times more than blood). The majority of CD34+ cells are found at a light transmission of 10%-70% (hematocrit 6-9). We conclude that cells for transplantation should be collected in a lighter fraction of the buffy coat than originally suggested by the manufacturer.

Rapid determination of milligram amounts of uranium in organic complexes with pyridine-2,6-dicarboxylic acid as titrant and arzenazo I as indicator after oxygen-flask combustion.

A method is described which allows the determination of uranium in organic complexes following decomposition by the oxygen-flask procedure. Uranium is quantitatively determined by a direct titration with 0.01M pyridine-2,6-dicarboxylic acid, arsenazo I being used as the indicator. The end-point is sharp and the equilibrium is rapidly attained, so the titration can be carried out rapidly. The method is simple, rapid and highly reproducible.

Gravimetric determination of uranium(VI) with pyridine-2,6-dicarboxylic acid.

Uranium(VI) can be quantitatively precipitated from aqueous solution in the pH range 2.1-6.9 with pyridine-2,6-dicarboxylic acid in the presence of tetraphenylarsonium chloride. This provides a new rapid gravimetric method for uranyl ion as an organic chelate complex of high molecular weight. Sodium, aluminium, copper and nickel as well as nitrate, chloride, sulphate and acetate ions, do not interfere, but iron(III) and thorium(IV) do.