Randomized clinical trial of the effect of intraoperative humidified carbon dioxide insufflation in open laparotomy for colorectal resection.

BACKGROUND: Animal studies have shown that peritoneal injury can be minimized by insufflating the abdominal cavity with warm humidified carbon dioxide gas. METHODS: A single-blind RCT was performed at a tertiary colorectal unit. Inclusion criteria were patient aged 18 years and over undergoing open elective surgery. The intervention group received warmed (37°C), humidified (98 per cent relative humidity) carbon dioxide (WHCO2  group). Multiple markers of peritoneal inflammation and oxidative damage were used to compare groups, including cytokines and chemokines, apoptosis, the 3-chlorotyrosine/native tyrosine ratio, and light microscopy on peritoneal biopsies at the start (T0 ) and end (Tend ) of the operation. Postoperative clinical outcomes were compared between the groups. RESULTS: Of 40 patients enrolled, 20 in the WHCO2 group and 19 in the control group were available for analysis. A significant log(Tend /T0 ) difference between control and WHCO2 groups was documented for interleukin (IL) 2 (5·3 versus 2·8 respectively; P = 0·028) and IL-4 (3·5 versus 2·0; P = 0·041), whereas apoptosis assays documented no significant change in caspase activity, and similar apoptosis rates were documented along the peritoneal edge in both groups. The 3-chlorotyrosine/tyrosine ratio had increased at Tend by 1·1-fold in the WHCO2 group and by 3·1-fold in the control group. Under light microscopy, peritoneum was visible in 11 of 19 samples from the control group and in 19 of 20 samples from the WHCO2 group (P = 0·006). The only difference in clinical outcomes between intervention and control groups was the number of days to passage of flatus (2·5 versus 5·0 days respectively; P = 0·008). CONCLUSION: The use of warmed, humidified carbon dioxide appears to reduce some markers related to peritoneal oxidative damage during laparotomy. No difference was observed in clinical outcomes, but the study was underpowered for analysis of surgical results. Registration number: NCT02975947 ( www.ClinicalTrials.gov/).

ANTECEDENTES: Los estudios en animales han demostrado que la lesión peritoneal se puede minimizar insuflando gas de dióxido de carbono caliente y humidificado (warm, humidified carbon dioxide gas,WHCO2(g) ) en la cavidad abdominal. El objetivo de este ensayo fue investigar los marcadores de inflamación peritoneal y de daño oxidativo en pacientes sometidos a cirugía colorrectal y abdominal tratados dióxido de carbono calentado humidificado en comparación con controles. El objetivo secundario fue evaluar los resultados clínicos perioperatorios. MÉTODOS: Se llevó a cabo un ensayo aleatorizado, controlado y simple ciego en una unidad colorrectal terciaria. Se incluyeron pacientes de > 18 años de edad sometidos operaciones electivas por vía abierta. El grupo de intervención recibió CO2(g) calentado (37°C) y humidificado (98% humedad relativa). Para la comparación de los grupos, se determinaron múltiples marcadores de inflamación peritoneal y daño oxidativo, incluyendo citocinas y quimiocinas, apoptosis (actividad Caspasas -3 y -7 y DeadEndTM TUNEl sistema fluorométrico), la tasa 3-clorotirosina/tirosina nativa (HPLC-MS) y microscopía electrónica de biopsias peritoneales al inicio (T0 ) y al término (Tfinal ) de la operación. Los resultados clínicos postoperatorios se compararon entre los grupos. RESULTADOS: De los 40 pacientes incluidos en el estudio, se dispuso de datos para el análisis en 20 pacientes asignados al grupo de CO2 y en 19 asignados al grupo control. Se observó una diferencia significativa Log(Tend/T0) entre los grupos respecto a IL-2 (grupo control: 5,34, grupo CO2: 2,78, P = 0,028) y IL-4 (grupo control: 3,53, grupo CO2: 2,00, P = 0,04), en tanto que los análisis relativos a la apoptosis no pusieron de manifiesto cambios significativos en la actividad de la caspasa, y se observaron tasas de apoptosis similares a lo largo del borde peritoneal en ambos grupos. La tasa 3-clorotirosina/tirosina nativa aumentó en 1,05 veces en el grupo del CO2 y en 3,1 veces en el grupo control. Por microscopía óptica el peritoneo era visible en el 57,9% de los sujetos del grupo control y en el 95% de los que recibieron tratamiento con WHCO2(g) (P = 0,006). La única diferencia en los resultados clínicos entre los grupos de intervención y control fue el número de días para el paso de gases (2,5 en el grupo de CO2 versus 5,0 días en el grupo control, P = 0,008). CONCLUSIÓN: El uso de WHCO2(g) parece disminuir algunos de los marcadores relacionados con el daño peritoneal por estrés oxidativo durante la laparotomía. Aunque no se observaron diferencias en los resultados clínicos, el estudio no tenía la suficiente potencia para analizar los resultados quirúrgicos.

Modeling of DNA transport in viscoelastic electro-hydrodynamic flows for enhanced size separation.

DNA separation and analysis have advanced over recent years, benefiting from microfluidic systems that reduce sample volumes and analysis costs, essential for sequencing and disease identification in body fluids. We recently developed the µLAS technology that enables the separation, concentration, and analysis of nucleic acids with high sensitivity. The technology combines a hydrodynamic flow actuation and an opposite electrophoretic force in viscoelastic polymer solutions. Combining hydrodynamics first principles and statistical mechanics, we provide, in this paper, a quantitative model of DNA transport capable of predicting device performance with the exclusive use of one adjustable parameter associated with the amplitude of transverse viscoelastic forces. The model proves to be in remarkable agreement with DNA separation experiments, and allows us to define optimal conditions that result in a maximal resolution length of 7 bp. We finally discuss the usefulness of our model for separation technologies involving viscoelastic liquids.

The nitroxide 4-methoxy TEMPO inhibits neutrophil-stimulated kinase activation in H9c2 cardiomyocytes.

After acute myocardial infarction (AMI), neutrophils are recruited to the affected myocardium. Hypochlorous acid (HOCl) produced by neutrophil myeloperoxidase (MPO) damages cardiomyocytes and potentially expands the primary infarct. Rat cardiomyocyte-like cells were incubated with isolated human neutrophils treated with chemical activators in the absence or presence of nitroxide 4-methoxy-Tempo (MetT; 25 µM) for 4, 6 or 24 h; studies with reagent HOCl served as positive control. Treating cardiomyocytes with activated neutrophils or reagent HOCl resulted in a marked increase in protein tyrosine chlorination and a decline in protein tyrosine phosphatase (PTP) activity. On balance our data also supported an increase in phosphorylation of MAPK p38 and ERK1/2 suggestive of an intracellular hyperphosphorylation status and this was accompanied by decreases in cell viability, as judged by assessing caspases-3/7 activity. For cells exposed to activated neutrophils receptor-mediated uptake of transferrin decreased although total matrix metalloproteinase (MMP) activity was unaffected. Addition of MetT ameliorated protein tyrosine chlorination, decreased MAPK activity and restored receptor-mediated transferrin uptake and PTP activity in cardiomyocytes. Overall, adverse effects of neutrophil-derived HOCl on cultured cardiomyocytes were ameliorated by MetT suggesting that nitroxides may be beneficial to inflammatory pathologies, where neutrophil recruitment/activation is a prominent and early feature.

The rise and fall of insulin signaling in Alzheimer's disease.

The prevalence of both diabetes and Alzheimer's disease (AD) are reaching epidemic proportions worldwide. Alarmingly, diabetes is also a risk factor for Alzheimer's disease. The AD brain is characterised by the accumulation of peptides called Aß as plaques in the neuropil and hyperphosphorylated tau protein in the form of neurofibrillary tangles within neurons. How diabetes confers risk is unknown but a simple linear relationship has been proposed whereby the hyperinsulinemia associated with type 2 diabetes leads to decreased insulin signaling in the brain, with downregulation of the PI3K/AKT signalling pathway and its inhibition of the major tau kinase, glycogen synthase kinase 3ß. The earliest studies of post mortem AD brain tissue largely confirmed this cascade of events but subsequent studies have generally found either an upregulation of AKT activity, or that the relationship between insulin signaling and AD is independent of glycogen synthase kinase 3ß altogether. Given the lack of success of beta-amyloid-reducing therapies in clinical trials, there is intense interest in finding alternative or adjunctive therapeutic targets for AD. Insulin signaling is a neuroprotective pathway and represents an attractive therapeutic option. However, this incredibly complex signaling pathway is not fully understood in the human brain and particularly in the context of AD. Here, we review the ups and downs of the research efforts aimed at understanding how diabetes modifies AD risk.

[Study of 206 transfused sickle cell disease patients: immunization, transfusion safety and red blood cell supply]. / Etude d'une cohorte de 206 patients drépanocytaires adultes transfusés: immunisation, risque transfusionnel et ressources en concentrés globulaires.

BACKGROUND: Prevention of hemolytic transfusion reactions depends upon our capacity to prevent allo-immunization and conflicts between antigens of transfused red blood cells and antibodies produced by the recipient. In this study, we show that to secure transfusion of sickle cell disease patients, it is necessary to take into account their immunohematologic characteristics in the organization of transfusion. METHODS AND RESULTS: Immunohematological data of 206 chronically transfused patients have been collected as well as phenotypes of transfused units. In order to prevent allo-immunization against C and E antigens for patients typed D+C-E-c+e+ (56%), 26% of the transfused units were D-C-E-c+e+. We found that 47% of the patients had a history of allo-immunization, whereas only 15% produced an antibody the day of inclusion in the study. The non-detectable antibodies were frequently known as dangerous for transfusion. Finally, this study shows the frequency of anti-D in D+ patients and anti-C in C+ patients, pointing out the question of partial antigens. CONCLUSION: To insure optimal transfusion safety for sickle cell disease patients, three points have to be improved: blood donation within the Afro-Caribbean community living in France, access to history of immuno-hematological data, detection of variant antigens, especially within the RH blood system.

Intracerebral hemorrhage survival: French register data.

Cerebral hemorrhages are subject to a heavy short- and long-term case fatality. A study of prognostic factors and of relative survival based on the data of a population registry is of great value to study patients having a hematoma of all ages, irrespective of the method of care. We have listed 183 patients having a cerebral hemorrhage between 1 January 1985 and 31 December 1996 and living in the city of Dijon, France. Eighteen clinical and CT-scanning variables have been studied. We have found four predictive factors of death at one month from cerebral hemorrhages. These are, in decreasing order: the existence of consciousness disorders at the initial clinical examination (OR = 5.80, p < 0.0001); an intraventricular hemorrhage (OR = 5.60, p < 0.0001); a hematoma volume over 11 cubic centimeters (OR = 3.53, p = 0.027); lastly, in male patients an age over 70 years (OR = 4.90, p = 0.039). With regard to long-term survival, the existence of consciousness disorders remains the principal predictive factor of case fatality in both crude and relative survival (OR = 5.52, p < 0.0001, in crude survival versus OR = 22.2 in relative survival, p < 0.0001), followed by age over 70 years (OR = 3.71, p < 0.0001 in crude survival and OR = 2.41 in relative survival, p = 0.086). The existence of consciousness disorders at the initial examination following a cerebral hemorrhage would seem to be the principal worst prognostic factor of short- and long-term survival and of relative survival, age and sex having less importance. Moreover, intraventricular hemorrhage and hematoma volume are short-term, pejorative factors. These data, based on a population-based registry, are an important consideration in the acute management of hemorrhagic therapy, and for the design of further therapeutic trials on this severe pathology.

Geographic distribution of 119 alleles of the alpha and beta globin genes detected in 432 French Caucasian carriers of haemoglobin variant.

The French population is the result of mixing of different peoples including the Celts, Saxons, Germans, Italians and Hispanics. Between 1981 and 1993 patients were selected during investigations in France for haematological disorders associated or otherwise with the presence of a haemoglobin (Hb) variant. Further carriers of abnormal Hb were identified by HPLC measurement of glycated Hb in diabetics and by neonatal screening. Four-hundred and thirty-two subjects were found to be heterozygous for one of the 119 different alpha and the beta gene alleles encountered. These variants were characterised by a combination of 6 electrophoretic methods and in some cases by protein structure determinations. Some mutants reflected the population movements in and into France. A few mutants are frequently described in the French Caucasian population: Hb Lepore Boston, Hb D Punjab, whereas others appear to be anthropological markers. Hb Winnipeg has only been found in the West of France (Normandy); Hb J Baltimore is mainly found in French subjects of Spanish origin. Several cases of sporadic and previously undescribed mutations of Hb were identified. The last immigration waves from Africa and Asia appear to have contributed to the evolution of the pattern of haemoglobinopathies in the French population (Hb S, Hb O Arab or Hb C).

Hemoglobin variants in North Africa.

The populations of Morocco, Algeria, and Tunisia are composed of different ethnic groups including Arabs, Berbers, Sub-Saharan Africans, Europeans, and Turks. Between 1981 and 1991, we studied more than 3,000 individuals from these North African countries. One-hundred and eighty-one carried one (or more) unusual hemoglobin variant(s) other than Hb S and Hb C which are the most frequent variants in these countries. Each of these 181 individuals was heterozygous for at least one of the 49 abnormal alpha or beta alleles identified by electrophoretic and/or structural studies, and some homozygotes were detected. A few mutants are common in North Africa: Hb O-Arab, Hb D-Punjab and Hb G-Philadelphia. Other mutants encountered in European or African populations are found in relatively few North African families. The observed polymorphisms in the populations of North Africa probably result largely from their complex ethnic origins.