Sprayed cultured autologous keratinocytes in the treatment of severe burns: a retrospective matched cohort study.

The standard treatment of burns is early excision followed by autologous skin grafting. The closure of extensive deep burns poses a considerable challenge. Cultured autologous keratinocytes have been used since 1981 in an effort to improve healing. However, the time required to culture the cells and the lack of a dermal component limit the expectations of outcome. Our aim was to compare the duration of hospital stay between patients who were treated with autologous skin grafts and cultured autologous keratinocytes and those who were treated with autologous skin grafting without cultured autologous keratinocytes. In this retrospective study all patients treated with cultured autologous keratinocytes between 2012 and 2015 were matched by size and depth of burn with patients not treated with cultured autologous keratinocytes. Multivariable regression was used to analyse associations between duration of hospital stay and treatment adjusted for age, mortality, size and depth of the burn. Then, we investigated the possibility of differentiation of human bone marrow stem cell line to keratinocyte- like cells as a future direction. The regression analysis showed a coefficient of 17.36 (95% CI -17.69 to 52.40), p= 0.32, for hospital stay in the treatment group, compared with the matched group. Our results showed no difference in the duration of hospital stay between the two treatments. Autologous stem cells should be considered as a future modality of burn management, although further studies are needed.

Le traitement de référence des brûlures est l'excision- greffe précoce, qui est problématique en cas d'atteinte étendue. La culture de kératinocytes autologues est utilisée depuis 1981 dans le but de répondre à cette problématique mais se heure au temps nécessaire à sa mise en oeuvre, ainsi qu'à l'absence de feuillet dermique, génératrice de séquelles. Cette étude a comparé la durée de séjour des patients traité par excision- greffe et culture de kératinocytes à celle des patients traités de manière conventionnelle. Les patients hospitalisés entre 2012 et 2015 ont été comparés à des patients de même surface et profondeur traités conventionnellement, en utilisant une analyse multivariée ajustée sur l'âge, la mortalité, la surface et la profondeur de la brûlure. L'analyse n'est pas significative (coefficient 17,36 ; IC95 -17,69 à 52,4 ; p= 0,32). Il serait utile d'étudier l'utilisation des cellules souches médullaires, différentiées en kératinocytes, dans un protocole de culture.

Treatment with a Toll-like Receptor 7 ligand evokes protective immunity against atherosclerosis in hypercholesterolaemic mice.

BACKGROUND: The interplay between innate and adaptive immunity is central in life-threatening clinical complications of atherosclerosis such as myocardial infarction and stroke. The specific mechanisms involved and their protective versus detrimental effects in the disease process remain poorly understood. We have previously shown that higher levels of Toll-like receptor 7 (TLR7) expression in human atherosclerotic lesions are correlated with better patient outcome. OBJECTIVE: In this study, we explored whether TLR7 activation can ameliorate disease in experimental atherosclerosis in mice. METHODS: Apolipoprotein E deficient mice (Apoe-/- ) with established disease were injected for five weeks intraperitoneally with the TLR7 ligand R848. Local effects were evaluated by characterization of the lesion. Systemic effects of the treatment were investigated by immune composition analysis in the spleen and plasma measurements. RESULTS: The in vivo treatment arrested lesion progression in the aorta. We also detected expansion of marginal zone B cells and Treg in the spleen together with increased plasma IgM antibodies against oxidized low-density lipoprotein (oxLDL) and reduced plasma cholesterol levels. These changes were accompanied by increased accumulation of IgM antibodies, decreased necrosis and fewer apoptotic cells in atherosclerotic lesions. CONCLUSIONS: Our findings show that TLR7 stimulation could ameliorate atherosclerotic lesion burden and reduce plasma cholesterol in Apoe-/- mice. TLR7 stimulation was associated with an atheroprotective B-cell and Treg response, which may have systemic and local effects within lesions that could prevent arterial lipid accumulation and inflammation.

Neural reflex control of vascular inflammation.

Atherosclerosis is a multifactorial chronic inflammatory disease that underlies myocardial infarction and stroke. Efficacious treatment for hyperlipidemia and hypertension has significantly reduced morbidity and mortality in cardiovascular disease. However, atherosclerosis still confers a considerable risk of adverse cardiovascular events. In the current mechanistic understanding of the pathogenesis of atherosclerosis, inflammation is pivotal both in disease development and progression. Recent clinical data provided support for this notion and treatment targeting inflammation is currently being explored. Interestingly, neural reflexes regulate cytokine production and inflammation. Hence, new technology utilizing implantable devices to deliver electrical impulses to activate neural circuits are currently being investigated in treatment of inflammation. Hopefully, it may become possible to target vascular inflammation in cardiovascular disease using bioelectronic medicine. In this review, we discuss neural control of inflammation and the potential implications of new therapeutic strategies to treat cardiovascular disease.

Dietary nitrate attenuates high-fat diet-induced obesity via mechanisms involving higher adipocyte respiration and alterations in inflammatory status.

Emerging evidence indicates that dietary nitrate can reverse several features of the metabolic syndrome, but the underlying molecular mechanisms still remain elusive. The aim of the present study was to explore mechanisms involved in the effects of dietary nitrate on the metabolic dysfunctions induced by high-fat diet (HFD) in mice. Four weeks old C57BL/6 male mice, exposed to HFD for ten weeks, were characterised by increased body weight, fat content, increased fasting glucose and impaired glucose clearance. All these metabolic abnormalities were significantly attenuated by dietary nitrate. Mechanistically, subcutaneous primary mouse adipocytes exposed to palmitate (PA) and treated with nitrite exhibited higher mitochondrial respiration, increased protein expression of total mitochondrial complexes and elevated gene expression of the thermogenesis gene UCP-1, as well as of the creatine transporter SLC6A8. Finally, dietary nitrate increased the expression of anti-inflammatory markers in visceral fat, plasma and bone marrow-derived macrophages (Arginase-1, Egr-2, IL-10), which was associated with reduction of NADPH oxidase-derived superoxide production in macrophages. In conclusion, dietary nitrate may have therapeutic utility against obesity and associated metabolic complications possibly by increasing adipocyte mitochondrial respiration and by dampening inflammation and oxidative stress.

The impact of contracts on outsourcing computed tomography examinations from a Swedish public university hospital to a private radiology unit.

INTRODUCTION: After years of outsourcing without detailed contracts from one of Sweden's largest university hospitals to external radiology units, the hospital started to use a specific contract for outsourcing computed tomography (CT) examinations. The purpose of this study was to compare the cost-effectiveness of two outsourcing approaches, where examinations were performed either with a detailed, specific contract (with-contract) or without (no-contract), between a hospital radiology department and private external units. METHODS: This retrospective study included a group of electively outsourced CT-examinations (n = 132) and a control group of in-house CT-examinations (n = 132), selected from the three different types of CT-examinations referred from the Departments of Oncology and Hematology. These examinations were randomly selected from four different groups over two time periods of one year each, one being outsourcing without a contract (no-contract, during 2013), one time period with a specific contract (with-contract, during 2014) and two control groups of examinations performed in-house within both these time periods. We compared outsourced examinations (both no-contract and with-contract groups) and in-house examinations. The comparison of these groups include five parameters; management-time, patient waiting-time, the quality of the examinations, - image interpretations and costs. RESULTS: During 2013, management-time for CT-examinations was longer in the outsourced group (no-contract) than in the in-house group, with a statistical significance (P = 0.002). Fewer examinations performed in-house and in the with-contract group needed re-interpretation than in the no-contract group. CT-examinations in the with-contract group were associated with shorter overall management-time, patient waiting time and lower costs compared to the no-contract group. CONCLUSION: Using a contract with detailed specifications for outsourcing CT-examinations may be an effective way of reducing patient waiting time. Outsourcing based on a well-founded contract can be cost-effective, compared with outsourcing without a detailed plan for the services required.

Plausible scenarios for the radiography profession in Sweden in 2025.

INTRODUCTION: Radiography is a healthcare speciality with many technical challenges. Advances in engineering and information technology applications may continue to drive and be driven by radiographers. The world of diagnostic imaging is changing rapidly and radiographers must be proactive in order to survive. To ensure sustainable development, organisations have to identify future opportunities and threats in a timely manner and incorporate them into their strategic planning. Hence, the aim of this study was to analyse and describe plausible scenarios for the radiography profession in 2025. METHOD: The study has a qualitative design with an inductive approach based on focus group interviews. The interviews were inspired by the Scenario-Planning method. RESULTS: Of the seven trends identified in a previous study, the radiographers considered two as the most uncertain scenarios that would have the greatest impact on the profession should they occur. These trends, labelled "Access to career advancement" and "A sufficient number of radiographers", were inserted into the scenario cross. The resulting four plausible future scenarios were: The happy radiographer, the specialist radiographer, the dying profession and the assembly line. CONCLUSION: It is suggested that "The dying profession" scenario could probably be turned in the opposite direction by facilitating career development opportunities for radiographers within the profession. Changing the direction would probably lead to a profession composed of "happy radiographers" who are specialists, proud of their profession and competent to carry out advanced tasks, in contrast to being solely occupied by "the assembly line".

A novel flexible cuff-like microelectrode for dual purpose, acute and chronic electrical interfacing with the mouse cervical vagus nerve.

OBJECTIVE: Neural reflexes regulate immune responses and homeostasis. Advances in bioelectronic medicine indicate that electrical stimulation of the vagus nerve can be used to treat inflammatory disease, yet the understanding of neural signals that regulate inflammation is incomplete. Current interfaces with the vagus nerve do not permit effective chronic stimulation or recording in mouse models, which is vital to studying the molecular and neurophysiological mechanisms that control inflammation homeostasis in health and disease. We developed an implantable, dual purpose, multi-channel, flexible 'microelectrode' array, for recording and stimulation of the mouse vagus nerve. APPROACH: The array was microfabricated on an 8 µm layer of highly biocompatible parylene configured with 16 sites. The microelectrode was evaluated by studying the recording and stimulation performance. Mice were chronically implanted with devices for up to 12 weeks. MAIN RESULTS: Using the microelectrode in vivo, high fidelity signals were recorded during physiological challenges (e.g potassium chloride and interleukin-1ß), and electrical stimulation of the vagus nerve produced the expected significant reduction of blood levels of tumor necrosis factor (TNF) in endotoxemia. Inflammatory cell infiltration at the microelectrode 12 weeks of implantation was limited according to radial distribution analysis of inflammatory cells. SIGNIFICANCE: This novel device provides an important step towards a viable chronic interface for cervical vagus nerve stimulation and recording in mice.

Temporary coverage of burns with a xenograft and sequential excision, compared with total early excision and autograft.

During the 80s and 90s, early and total excision of full thickness burns followed by immediate autograft was the most common treatment, with repeated excision and grafting, mostly for failed grafts. It was hypothesized, therefore, that delayed coverage with an autograft preceded by a temporary xenograft after early and sequential smaller excisions would lead to a better wound bed with fewer failed grafts, a smaller donor site, and possibly also a shorter duration of stay in hospital. We carried out a case control study with retrospective analysis from our National Burn Centre registry for the period 1997-2011. Patients who had been managed with early total excision and autograft were compared with those who had had sequential smaller excisions covered with temporary xenografts until the burn was ready for the final autograft. The sequential excision and xenograft group (n=42) required one-third fewer autografts than patients in the total excision and autograft group (n=45), who needed more than one operation (p<0.001). We could not detect any differences in duration of stay in hospital / total body surface area burned% (duration of stay/TBSA%) (2.0 and 1.8) (p=0.83). The two groups showed no major differences in terms of adjusted duration of stay, but our findings suggest that doing early, smaller, sequential excisions using a xenograft for temporary cover can result in shorter operating times, saving us the trouble of making big excisions. However, costs tended to be higher when the burns were > 25% TBSA.

Pendant ces dernières décades, l'excision précoce et totale des brûlures profondes, suivie immédiatement d'autogreffe a constitué le traitement le plus habituel avec souvent, en cas d'échec, des excisions répétées et de nouvelles greffes. Nous avons pensé, cependant, que la couverture par autogreffe retardée, précédée par une couverture temporaire par xénogreffe après des excisions itératives et moins larges permettait d'obtenir un meilleur lit receveur avec moins d'échecs, des sites donneurs plus petits et une durée d'hospitalisation moindre. Nous avons ainsi mené une étude analytique rétrospective dans notre Centre National de Brûlés pendant la période 1997-2011. Les patients qui avaient été traités par une excision précoce totale suivie d'autogreffe ont été comparés à ceux qui avaient eu des petites excisions séquentielles, couvertes de façon temporaire par des xénogreffes jusqu'à ce que la brûlure soit prête pour une autogreffe finale. Le groupe excision séquentielle et xénogreffe (n=42) a nécessité un tiers de moins d'autogreffes que les patients qui avaient une excision totale suivie d'autogreffe (n=45) et plus d'une seule opération (p<0001). Nous n'avons pas remarqué de différence dans la durée d'hospitalisation en fonction de l'étendue de la surface brûlée (durée du séjour TBSA%) (2,0 et 1,8) (p=0,83). Les deux groupes n'ont pas montré de différence majeure en terme de durée d'hospitalisation, mais l'excision précoce, limitée et séquentielle avec une xénogreffe temporaire, permet de réduire le temps opératoire et évite les excisions trop généreuses. Cependant les coûts ont tendance à être plus élevés avec les brûlures de 25% ou plus de TBSA.

The collagen cross-linking enzyme lysyl oxidase is associated with the healing of human atherosclerotic lesions.

BACKGROUND: Acute clinical complications of atherosclerosis such as myocardial infarction (MI) and ischaemic stroke are usually caused by thrombus formation on the ruptured plaque surface. Collagen, the main structural protein of the fibrous cap, provides mechanical strength to the atherosclerotic plaque. The integrity of the fibrous cap depends on collagen fibre cross-linking, a process controlled by the enzyme lysyl oxidase (LOX). METHODS AND RESULTS: We studied atherosclerotic plaques from human carotid endarterectomies. LOX was strongly expressed in atherosclerotic lesions and detected in the regions with ongoing fibrogenesis. Higher LOX levels were associated with a more stable phenotype of the plaque. In the studied population, LOX mRNA levels in carotid plaques predicted the risk for future MI. Within the lesion, LOX mRNA levels correlated positively with levels of osteoprotegerin (OPG) and negatively with markers of immune activation. The amount of LOX-mediated collagen cross-links in plaques correlated positively also with serum levels of OPG. CONCLUSIONS: Lysyl oxidase may contribute to the healing of atherosclerotic lesions and to the prevention of its lethal complications. Mediators of inflammation may control LOX expression in plaques and hence plaque stability.

HMGB1 mediates splenomegaly and expansion of splenic CD11b+ Ly-6C(high) inflammatory monocytes in murine sepsis survivors.

BACKGROUND: More than 500,000 hospitalized patients survive severe sepsis annually in the USA. Recent epidemiological evidence, however, demonstrated that these survivors have significant morbidity and mortality, with 3-year fatality rates higher than 70%. To investigate the mechanisms underlying persistent functional impairment in sepsis survivors, here we developed a model to study severe sepsis survivors following cecal ligation and puncture (CLP). METHODS: Sepsis was induced in mice by CLP and survivors were followed for twelve weeks. Spleen and blood were collected and analyzed at different time points post-sepsis. RESULTS: We observed that sepsis survivors developed significant splenomegaly. Analysis of the splenic cellular compartments revealed a major expansion of the inflammatory CD11b+ Ly-6CHigh pool. Serum high-mobility group box 1 (HMGB1) levels in the sepsis surviving mice were significantly elevated for 4-6 weeks after post-sepsis, and administration of an anti-HMGB1 monoclonal antibody significantly attenuated splenomegaly as well as splenocyte priming. Administration of recombinant HMGB1 to naive mice induced similar splenomegaly, leukocytosis and splenocyte priming as observed in sepsis survivors. Interestingly analysis of circulating HMGB1 from sepsis survivors by mass spectroscopy demonstrated a stepwise increase of reduced form of HMGB1 (with known chemo-attractant properties) during the first 3 weeks, followed by disulphide form (with known inflammatory properties) 4-8 weeks after CLP. DISCUSSION: Our results indicate that prolonged elevation of HMGB1 is a necessary and sufficient mediator of splenomegaly and splenocyte expansion, as well as splenocyte inflammatory priming in murine severe sepsis survivors.

Hidden acidosis: an explanation of acid-base and lactate changes occurring in umbilical cord blood after delayed sampling.

OBJECTIVE: To explore the 'hidden acidosis' phenomenon, in which there is a washout of acid metabolites from peripheral tissues in both vaginal and abdominal deliveries, by investigating temporal umbilical cord blood acid-base and lactate changes after delayed blood sampling. DESIGN: Prospective comparative study. SETTING: University hospital. SAMPLE: Umbilical cord blood from 124 newborns. METHODS: Arterial and venous cord blood was sampled immediately after birth (T0), and at 45 seconds (T45), from unclamped cords with intact pulsations taken from 66 neonates born vaginally and 58 neonates born via planned caesarean section at 36-42 weeks of gestation. Non-parametric tests were used for statistical comparisons, with P < 0.05 considered significant. MAIN OUTCOME MEASURES: Temporal changes (T0-T45) in umbilical cord blood pH, the partial pressure of CO2 (PCO2) and O2 (PO2), and in the concentrations of lactate, haematocrit (Hct), and haemoglobin (Hb). RESULTS: In both groups all arterial parameters, except for PCO2 in the group delivered by caesarean section, changed significantly (pH decreased and the other variables increased). There were corresponding changes in venous acid-base parameters. When temporal arterial changes were compared between the two groups, the decrease in pH and increase in PCO2 were more pronounced in the group delivered vaginally. Neonates born vaginally had significantly lower pH and higher lactate, Hct, and Hb concentrations at T0 and T45 in both the artery and the vein. At T45, arterial PCO2 and PO2 levels in the group delivered vaginally were also significantly higher. CONCLUSIONS: Delayed umbilical cord sampling affected the acid-base balance and haematological parameters after both vaginal and caesarean deliveries, although the effect was more marked in the group delivered vaginally. The hidden acidosis phenomenon explains this change towards acidaemia and lactaemia. Arterial haemoconcentration was not the explanation of the acid-base drift.

Finemapping of the arthritis QTL Pia7 reveals co-localization with Oia2 and the APLEC locus.

In this study, we sought to determine the effect of the quantitative trait locus Pia7 on arthritis severity. The regulatory locus derived from the arthritis-resistant E3 rat strain was introgressed into the arthritis-susceptibility DA strain through continuous backcrossing. Congenic rats were studied for their susceptibility to experimental arthritis using pristane and adjuvant oil. In addition, cell number and function of various leukocyte populations were analyzed either under naive or stimulated conditions. We found that the minimal congenic fragment of DA.E3-Pia7 rats overlapped with the minimal fragment in DA.PVG-Oia2 congenic rats, which has been positionally cloned to the antigen-presenting lectin-like receptor complex (APLEC) genes. DA.E3-Pia7 congenic rats were protected from both PIA and OIA, but the protection was more pronounced in OIA. In adoptive transfer experiments we observed that the Pia7 locus controlled the priming of arthritogenic T cells and not the effector phase. In addition, Pia7 congenic rats had a significant higher frequency of B cells and granulocytes as well as TNFalpha production after stimulation, indicating a higher activation state of cells of the innate immune system. In conclusion, this study shows that the APLEC locus is a major locus regulating the severity of experimentally induced arthritis in rats.

Pulsations in the umbilical vein during labor are associated with increased risk of operative delivery for fetal distress.

OBJECTIVES: Under physiological conditions the blood flow velocity waveform in the umbilical vein (UV) has an even non-pulsating pattern. Pulsations in the UV have been described in human fetuses exposed to chronic hypoxia and heart failure. Current techniques for fetal surveillance during labor and delivery involve a risk of both over- and underestimation of fetal hypoxia. We aimed to examine whether pulsations in the UV appear in the human fetus during suspected intrapartum hypoxia, and if so whether they are associated with increased risk of operative delivery for fetal distress (ODFD). METHODS: This was a prospective double blind study including 52 normal pregnancies. A Doppler examination of the UV was performed on 26 fetuses with pathological and 26 fetuses with normal cardiotocography (CTG) during labor. Presence or absence of pulsations in the UV were noted and related to perinatal outcome. RESULTS: Pulsations in the UV were seen in eight (30.8%) of the fetuses with pathological CTG, of which six (75%) underwent ODFD. No pulsations were seen in the other 18 (69.2%) fetuses with pathological CTG and these were all delivered without ODFD. No pulsations were seen in the UV in the fetuses with normal CTG and these were all delivered without ODFD. Among the fetuses with pathological CTG, there was an increased risk of ODFD in fetuses with vs. those without pulsations in the UV (P < 0.0001). CONCLUSIONS: Pulsations in the UV can be observed in human fetuses during suspected intrapartum hypoxia and these pulsations are associated with an increased risk of ODFD. Doppler examination of the UV might give important additional information on fetal condition during labor and delivery.

Multiple small bowel ligation compared to conventional primary repair after abdominal gunshot wound with haemorrhagic shock.

AIMS: The aim of this study was to evaluate the effects of early rapid control of multiple bowel perforations on cardiovascular function in combined abdominal missile trauma and haemorrhagic shock compared with conventional surgery. METHODS: Eighteen anesthetised pigs were injured with a standardised abdominal missile trauma. The animals were bled to a mean arterial pressure of 50 mm Hg for 30 minutes, after which they were resuscitated and had laparotomy. They were divided into conventional surgery group (n=9) with primary resection and anastomosis of bowel -injuries and early rapid multiple bowel ligation group (n?=?9). Repeated measurement analysis of variance was used for analysis. RESULTS: There was profound hypotension, reduced cardiac output, increased vascular resistance and lactic acidaemia in both groups. Lactic acidaemia persisted longer in the early rapid multiple bowel ligation group. There were no significant differences in mean arterial pressure, cardiac output , stroke volume or systemic vascular resistance between the groups. The mean operation time was significantly shorter in the early rapid multiple bowel ligation group (13.3 (1.5) (SEM) minutes, compared with 116.4 (1.74) (SEM) minutes in the conventional surgery group, p =0.001). CONCLUSIONS: Damage control principles have shortened the operating time in our model but did not improve the cardiovascular function and caused more lactic acidaemia than conventional repair.

Genetic variants of TNFSF4 and risk for carotid artery disease and stroke.

In two independent human cohorts, the minor allele of SNP rs3850641 in TNFSF4 was significantly more frequent in individuals with myocardial infarction than in controls. In mice, Tnfsf4 expression is associated with increased atherosclerosis. The expression of TNFSF4 in human atherosclerosis and the association between genotype and cerebrovascular disease have not yet been investigated. TNFSF4 messenger RNA (mRNA) levels were significantly higher in human atherosclerotic lesions compared with controls (730 +/- 30 vs 330 +/- 65 arbitrary units, p < 0.01). TNFSF4 was mainly expressed by macrophages in atherosclerotic lesions. In cell culture, endothelial cells upregulated TNFSF4 in response to tumor necrosis factor alpha (TNF-alpha; 460 +/- 110 vs 133 +/- 8 arbitrary units, p < 0.001 after 6 h of stimulation). We analyzed the TNFSF4 gene in 239 patients who had undergone carotid endarterectomy and 138 matching controls from The Biobank of Karolinska Carotid Endarterectomies and Stockholm Heart Epidemiology Program cohorts and 929 patients and 1,382 matching controls from the Sahlgrenska Academy Study on Ischemic Stroke and Case Control Study of Stroke cohorts, limiting inclusion to patients with ischemic stroke. Participants were genotyped for the rs3850641 SNP in TNFSF4. Genotype associations were neither found with TNFSF4 mRNA levels nor with atherosclerosis associated systemic factors or risk for stroke. This study shows that TNFSF4 is expressed on antigen-presenting cells in human carotid atherosclerotic lesions but provides no evidence for an association of TNFSF4 gene variation with the risk for ischemic stroke.

A pixel-based likelihood framework for analysis of fluorescence recovery after photobleaching data.

A new framework for the estimation of diffusion coefficients from data on fluorescence recovery after photobleaching (FRAP) with confocal laser scanning microscopy (CLSM) is presented. It is a pixel-based statistical methodology that efficiently utilizes all information about the diffusion process in the available set of images. The likelihood function for a series of images is maximized which gives both an estimate of the diffusion coefficient and a corresponding error. This framework opens up possibilities (1) to obtain localized diffusion coefficient estimates in both homogeneous and heterogeneous materials, (2) to account for time differences between the registrations at the pixels within each image, and (3) to plan experiments optimized with respect to the number of replications, the number of bleached regions for each replicate, pixel size, the number of pixels, the number of images in each series etc. To demonstrate the use of the new framework, we have applied it to a simple system with polyethylene glycol (PEG) and water where we find good agreement with diffusion coefficient estimates from NMR diffusometry. In this experiment, it is also shown that the effect of the point spread function is negligible, and we find fluorochrome-concentration levels that give a linear response function for the fluorescence intensity.

Abrogation of mitochondrial transcription in smooth muscle cells impairs smooth muscle contractility and vascular tone.

BACKGROUND: Smooth muscle cells (SMC) constitute the major contractile cell population of blood vessels and inner organs. SMC contraction depends on energy provided by adenosine triphosphate (ATP) catabolism, which can be generated through oxidative phosphorylation in mitochondria or by anaerobic glycolysis. Mitochondrial activity may also modulate smooth muscle tone by biotransformation of vasoactive mediators. Here, we study the role of mitochondrial DNA gene expression for vascular function in vivo. METHODS: Since loss of functional mitochondria in SMC may not be compatible with normal development, we generated mice with inducible SMC-specific abrogation of the mitochondrial transcription factor A (Tfam). Deletion of this gene leads to dysfunctional mitochondria and prevents aerobic ATP production in affected cells. RESULTS: Invasive blood pressure monitoring in live animals demonstrated that SMC specific Tfam deletion results in lower blood pressure and a defective blood-pressure response to stress, changes that were not compensated by increased heart rate. The contractility to agonists was reduced in arterial and gastric fundus strips from Tfam-deficient mice. Endothelium-dependent relaxation of arterial strips in response to ACh was also blunted. CONCLUSION: Our data show that mitochondrial function is needed for normal gastric contraction, vascular tone, and maintenance of normal blood pressure.

Delayed umbilical cord clamping at birth has effects on arterial and venous blood gases and lactate concentrations.

OBJECTIVE: To estimate the influence of delayed umbilical cord clamping at birth on arterial and venous umbilical cord blood gases, bicarbonate (HCO3-), base excess (BE) and lactate in vigorous newborns. SETTING: University hospital. DESIGN: Prospective observational. SAMPLE: Vaginally delivered term newborns. MATERIAL AND METHODS: Umbilical cord arterial and venous blood was sampled repeatedly every 45 seconds (T(0)= time zero; T(45)= 45 seconds, T(90)= 90 seconds) until the cord pulsations spontaneously ceased in 66 vigorous singletons with cephalic vaginal delivery at 36-42 weeks. Longitudinal comparisons were performed with the Wilcoxon signed-ranks matched pairs test. Mixed effect models were used to describe the shape of the regression curves. MAIN OUTCOME MEASURES: Longitudinal changes of umbilical cord blood gases and lactate. RESULTS: In arterial cord blood, there were significant decreases of pH (7.24-7.21), HCO3- (18.9-18.1 mmol/l) and BE (-4.85 to -6.14 mmol/l), and significant increases of PaCO(2) (7.64-8.07 kPa), PO(2) (2.30-2.74 kPa) and lactate (5.3-5.9 mmol/l) from T(0) to T(90), with the most pronounced changes at T(0)-T(45). Similar changes occurred in venous blood pH (7.32-7.31), HCO3- (19.54-19.33 mmol/l), BE (-4.93 to -5.19 mmol/l), PaCO(2) (5.69-5.81 kPa) and lactate (5.0-5.3 mmol/l), although the changes were smaller and most pronounced at T(45)-T(90). No significant changes were observed in venous PO(2). CONCLUSION: Persistent cord pulsations and delayed cord clamping at birth result in significantly different measured values of cord blood acid-base parameters.