Commonly applied positive end-expiratory pressures do not prevent functional residual capacity decline in the setting of intra-abdominal hypertension: a pig model

Introduction Intra-abdominal hypertension is common in critically ill patients and is associated with increased morbidity and mortality. The optimal ventilation strategy remains unclear in these patients. We examined the effect of positive end-expiratory pressures (PEEP) on functional residual capacity (FRC) and oxygen delivery in a pig model of intra-abdominal hypertension. Methods Thirteen adult pigs received standardised anaesthesia and ventilation. We randomised three levels of intra-abdominal pressure (3 mmHg (baseline), 18 mmHg, and 26 mmHg) and four commonly applied levels of PEEP (5, 8, 12 and 15 cmH2O). Intra-abdominal pressures were generated by inflating an intra-abdominal balloon. We measured intra-abdominal (bladder) pressure, functional residual capacity, cardiac output, haemoglobin and oxygen saturation, and calculated oxygen delivery. Results Raised intra-abdominal pressure decreased FRC but did not change cardiac output. PEEP increased FRC at baseline intra-abdominal pressure. The decline in FRC with raised intra-abdominal pressure was partly reversed by PEEP at 18 mmHg intra-abdominal pressure and not at all at 26 mmHg intra-abdominal pressure. PEEP significantly decreased cardiac output and oxygen delivery at baseline and at 26 mmHg intra-abdominal pressure but not at 18 mmHg intra-abdominal pressure. Conclusions In a pig model of intra-abdominal hypertension, PEEP up to 15 cmH2O did not prevent the FRC decline caused by intra-abdominal hypertension and was associated with reduced oxygen delivery as a consequence of reduced cardiac output. This implies that PEEP levels inferior to the corresponding intra-abdominal pressures cannot be recommended to prevent FRC decline in the setting of intra-abdominal hypertension

Objective measures for the assessment of post-operative pain in bos indicus bull calves following castration

The aim of the study was to assess pain in Bos indicus bull calves following surgical castration. Forty-two animals were randomised to four groups: no castration (NC, n = 6); castration with pre-operative lidocaine (CL, n = 12); castration with pre-operative meloxicam (CM, n = 12); and, castration alone (C, n = 12). Bodyweight was measured regularly and pedometers provided data on activity and rest from day −7 (7 days prior to surgery) to 13. Blood was collected for the measurement of serum amyloid A (SAA), haptoglobin, fibrinogen, and iron on days 0, 3 and 6. Bodyweight and pedometry data were analysed with a mixed effect model. The blood results were analysed with repeated measure one-way analysis of variance (ANOVA). There was no treatment effect on bodyweight or activity. The duration of rest was greatest in the CM group and lowest in the C group. There was a significant increase in the concentrations of SAA, haptoglobin, and fibrinogen in all of the groups from day 0 to 3. Iron concentrations were not different at the time points it was measured. The results of this study suggest that animals rest for longer periods after the pre-operative administration of meloxicam. The other objective assessments measured in this study were not able to consistently differentiate between treatment groups

Improving pregnancy outcomes in humans through studies in sheep

Experimental studies that are relevant to human pregnancy rely on the selection of appropriate animal models as an important element in experimental design. Consideration of the strengths and weaknesses of any animal model of human disease is fundamental to effective and meaningful translation of preclinical research. Studies in sheep have made significant contributions to our understanding of the normal and abnormal development of the fetus. As a model of human pregnancy, studies in sheep have enabled scientists and clinicians to answer questions about the etiology and treatment of poor maternal, placental, and fetal health and to provide an evidence base for translation of interventions to the clinic. The aim of this review is to highlight the advances in perinatal human medicine that have been achieved following translation of research using the pregnant sheep and fetus

Injury to the tunica media initiates atherogenesis in the presence of hyperlipidemia

Background and aimsFatty streaks initiating the formation of atheromatous plaque appear in the tunica intima. The tunica media is not known to be a nidus for lipid accumulation initiating atherogenesis. We assessed changes to the tunica media in response to a micro-injury produced in the pig aorta. In addition, we assessed human carotid endarterectomy plaques for indication of atheroma initiation in the tunica media.MethodsThree healthy landrace female pigs underwent laparotomy to inject autologous blood and create micro-hematomas at 6 sites within the tunica media of the infrarenal abdominal aorta. These pigs were fed a high-fat diet (HFD) for 4–12 weeks. Post-mortem aortas from all pigs, including a control group of healthy pigs, were serially stained to detect lipid deposits, vasa vasora (VV), immune cell infiltration and inflammatory markers, as well as changes to the vascular smooth muscle cell (vSMC) compartment. Moreover, 25 human carotid endarterectomy (CEA) specimens were evaluated for their lipid composition in the tunica media and intima.ResultsHigh lipid clusters, VV density, and immune cell infiltrates were consistently observed at 5 out of 6 injection sites under prolonged hyperlipidemia. The hyperlipidemic diet also affected the vSMC compartment in the tunica media adjacent to the tunica adventitia, which correlated with VV invasion and immune cell infiltration. Analysis of human carotid specimens post-CEA indicated that 32% of patients had significantly greater atheroma in the tunica media than in the arterial intima.ConclusionThe arterial intima is not the only site for atherosclerosis initiation. We show that injury to the media can trigger atherogenesis

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Anaemia and Hypoproteinaemia in Pregnant Sheep during Anaesthesia

The aim of this study was to document the packed cell volume (PCV), haemoglobin concentration and total protein concentration of maternal blood before, during and after anaesthesia. Six singleton Merino-cross pregnant ewes at 116-117 days of gestation were premedicated with intramuscular acepromazine (0.02 mg/kg) and buprenorphine (0.01 mg/kg), and anaesthesia was induced with intravenous midazolam and ketamine. Anaesthesia was maintained with isoflurane in 100% oxygen. Serial blood samples were collected the day before anaesthesia (baseline), immediately prior to induction of anaesthesia (pre-op), at the end of the procedure (intra-op) and the following day (post-op). There was a significant change in the PCV during the study (p = 0.003) with an initial decrease of 12.5% from the baseline (0.36 (0.36&#8211;0.4) to 0.315 (0.29&#8211;0.34), p = 0.044), a further intraoperative decrease of 41.7% from the baseline (0.21 (0.195&#8211;0.245), p = 0.002) and an increase the day afterwards (0.3 (0.285&#8211;0.35), p &gt; 0.99 compared with baseline). The haemoglobin concentration also changed (p &lt; 0.0001) (baseline: 114 (111.8&#8211;123); pre-op: 97 (77.25&#8211;104.5), 14.9% decrease, p = 0.022; intra-op: 70 (61.5&#8211;83.25), 38.5% decrease, p = 0.0009; post-op: 101.5 (96.25&#8211;114) g/L, p &gt; 0.99). Likewise the change in total protein during the study was significant (p = 0.0003) and decreased from the baseline [70 (67.25&#8211;70.75) g/L] prior to anaesthesia (61 (58.25&#8211;64.5) g/L, 12.9% decrease, p = 0.0437) and further during anaesthesia (55.5 (53.75&#8211;63.25) g/L, 20.7% decrease, p = 0.0021) with an increase [63 (61.25&#8211;67) g/L, p &gt; 0.99] on the first post-op day. In conclusion, intraoperative anaemia and hypoproteinaemia occurred in this study. These alterations are attributed to a combination of the side effects of acepromazine and haemodilution

Target-controlled infusion of propofol in dogs – evaluation of four targets for induction of anaesthesia

Article deposited according to publisher policies posted on SHERPA/RoMEO, January 4, 2011.Ye

Plasmagestuetzte Oberflaechenmodifizierung von Polypropen

The employment of polypropylene in clothing industry is restricted due to its low dye absorption. An increase in wettability of polypropylene fibers and a simultaneous increase of the interaction between dyes and fibres should be suitable procedure in order to increase the dye absorption. The author investigates the possibilities of plasma-assisted hydrophilization in order to improve the colouring properties. There is an increased water wettability of the surface of polypropylene in comparison to the untreated material with an increase in time of treatment in oxygen plasma, with an increase of the microwave input and with decreasing distance between probe material and microwave input. The degree of hydrophilization of polypropylene fibres treated by barriere discharge increases with increasing exposition time nearly being independent of the microwave performance. The oxygen supply does not influence the wettability during the plasma-assisted hydrophilization. The wettability of the surface of propylene foils decreases with increasing storage at atmosphere due to a reorientation of the plasma induced functional groups towards the interior of the foils. The wettability of plasma-assisted propylene foils in water nearly is unchanged. The functional groups are on the surface. With increasing duration of treatment in oxygen plasma and in barriere discharges, there is an increase of oxygen containing functional groups in the surface of polypropylene foils. XPS experiments at oxygen plasma treated polypropylene foils increases and then decreases with increasing duration of storage. This decrease is due to a reorientation of the oxygen containing groups from the surface into the bulk medium. With increasing duration of treatment, the surface roughness of the probe increases leading to a reduction of the contact angle with water and to an increase of the oxygen content in the surface. Beside the plasma induced insertion of oxygen containing groups, the author observes plasma induced etching processes resulting in degradation substances. The author also investigates the mount behavior of the dispersion colour Resolin Red FB and the mount behavior of the solution colours Sudan Blue II and Sudan Red B on polypropylene fibres treated by oxygen plasma and barriere discharge, respectively. The mount performance of all three colours on plasma treated fibres is greater in comparison to untreated materials. Polypropylene fibres treated by barriere discharge do not show this behavior due to the low degree of hydrophilization of the fibre surface. Sudan Blue II has the highest mount rate according to untreated and plasmatreated polypropylene fibres.SIGLEAvailable from: <a href=http://deposit.ddb.de/cgi-bin/dokserv?idn=966432460 target=NewWindow>http://deposit.ddb.de/cgi-bin/dokserv?idn=966432460</a> / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman