Activation of epidermal growth factor receptors is responsible for mucin synthesis induced by cigarette smoke

Mucus hypersecretion from hyperplastic airway goblet cells is a hallmark of chronic obstructive pulmonary disease (COPD). Although cigarette smoking is thought to be involved in mucus hypersecretion in COPD, the mechanism by which cigarette smoke induces mucus overproduction is unknown. Here we show that activation of epidermal growth factor receptors (EGFR) is responsible for mucin production after inhalation of cigarette smoke in airways in vitro and in vivo. In the airway epithelial cell line NCI-H292, exposure to cigarette smoke upregulated the EGFR mRNA expression and induced activation of EGFR-specific tyrosine phosphorylation, resulting in upregulation of MUC5AC mRNA and protein production, effects that were inhibited completely by selective EGFR tyrosine kinase inhibitors (BIBX1522, AG-1478) and that were decreased by antioxidants. In vivo, cigarette smoke inhalation increased MUC5AC mRNA and goblet cell production in rat airways, effects that were prevented by pretreatment with BIBX1522. These effects may explain the goblet cell hyperplasia that occurs in COPD and may provide a novel strategy for therapy in airway hypersecretory diseases.

Enhanced bone regeneration with a gold nanoparticle–hydrogel complex

A hybrid hydrogel composed of gelatin and gold nanoparticles (GNPs) was designed to evaluate the effect of new bone formation and proves itself to be useful as an implant material for treating defected bone tissues.

Multicentre randomized clinical trial of mechanical bowel preparation in elective colonic resection

Background

Recent studies have suggested that MBP does not lower the risk of postoperative septic complications after elective colorectal surgery. This randomized clinical trial assessed whether preoperative MBP is beneficial in elective colonic surgery.

Methods

A total of 1505 patients, aged 18–85 years with American Society of Anesthesiologists grades I–III, were randomized to MBP or no MBP before open elective surgery for cancer, adenoma or diverticular disease of the colon. Primary endpoints were cardiovascular, general infectious and surgical-site complications within 30 days, and secondary endpoints were death and reoperations within 30 days.

Results

A total of 1343 patients were evaluated, 686 randomized to MBP and 657 to no MBP. There were no significant differences in overall complications between the two groups: cardiovascular complications occurred in 5·1 and 4·6 per cent respectively, general infectious complications in 7·9 and 6·8 per cent, and surgical-site complications in 15·1 and 16·1 per cent. At least one complication was recorded in 24·5 per cent of patients who had MBP and 23·7 per cent who did not.

Conclusion

MBP does not lower the complication rate and can be omitted before elective colonic resection. Registration number: ISRCTN28535118 (http://www.controlled-trials.com).

What do American nephologists think about dialysis modality selection?

In the United States, 87.3% of the patients with end-stage renal disease (ESRD) requiring dialysis are treated with hemodialysis (HD) and 12.7% with peritoneal dialysis (PD). This represents a greater use of HD than in many other nations. We mailed a survey questionnaire to members of the National Kidney Foundation Council on Dialysis to better understand the attitudes of American nephrologists toward dialysis modality decisions. We received responses from 240 of 507 nephrologists (47.3%). The respondents were heavily involved in clinical dialysis work. Results showed that decisions regarding modality selection were strongly based on patient preference (4.54 on a scale of 1 to 5), quality of life (4.18), morbidity (4.02), and mortality (3.90), whereas the least important factors reported were facility reimbursement (2.09) and physician reimbursement (1.98). When asked about the current use of modalities, hospital-based HD and full-care HD were believed to be overused (2.63 for each on a scale of 1 [vastly overused] to 5 [vastly underused]), whereas home HD (4.29), continuous ambulatory PD (3.71), and cycler PD (3.59) were underused. A hypothetical question about optimal modality distribution to maximize survival or cost-effectiveness showed that HD should constitute 71% or 66% of dialysis (with 11% or 14% in the form of home HD, respectively). PD use would increase between two- and threefold over current practices. Our results suggest that American nephrologists believe home therapies are underused. Because modality distribution is an important determinant of costs and possibly outcomes in patients with ESRD, there is an urgent need for further research in this area.

Difficult intubation in obese patients: incidence, risk factors, and complications in the operating theatre and in intensive care units

BACKGROUND

Intubation procedure in obese patients is a challenging issue both in the intensive care unit (ICU) and in the operating theatre (OT). The objectives of the study were (i) to compare the incidence of difficult intubation and (ii) its related complications in obese patients admitted to ICU and OT.

METHODS

We conducted a multicentre prospective observational cohort study in ICU and OT in obese (BMI≥30 kg m(-2)) patients. The primary endpoint was the incidence of difficult intubation. Secondary endpoints were the risk factors for difficult intubation, the use of difficult airway management techniques, and severe life-threatening complications related to intubation (death, cardiac arrest, severe hypoxaemia, severe cardiovascular collapse).

RESULTS

In cohorts of 1400 and 11 035 consecutive patients intubated in ICU and in the OT, 282 (20%) and 2103 (19%) were obese. In obese patients, the incidence of difficult intubation was twice more frequent in ICU than in the OT (16.3% vs 8.2%, P<0.01). In both cohorts, risk factors for difficult intubation were Mallampati score III/IV, obstructive sleep apnoea syndrome, and reduced mobility of cervical spine, while limited mouth opening, severe hypoxaemia, and coma appeared only in ICU. Specific difficult airway management techniques were used in 66 (36%) cases of difficult intubation in obese patients in the OT and in 10 (22%) cases in ICU (P=0.04). Severe life-threatening complications were significantly more frequent in ICU than in the OT (41.1% vs 1.9%, relative risk 21.6, 95% confidence interval 15.4-30.3, P<0.01).

CONCLUSIONS

In obese patients, the incidence of difficult intubation was twice more frequent in ICU than in the OT and severe life-threatening complications related to intubation occurred 20-fold more often in ICU.

CLINICAL TRIAL REGISTRATION

Current controlled trials. Identifier: NCT01532063.

Ultra-deep next-generation sequencing of plasma cell-free DNA in patients with advanced lung cancers: results from the Actionable Genome Consortium

BACKGROUND

Noninvasive genotyping using plasma cell-free DNA (cfDNA) has the potential to obviate the need for some invasive biopsies in cancer patients while also elucidating disease heterogeneity. We sought to develop an ultra-deep plasma next-generation sequencing (NGS) assay for patients with non-small-cell lung cancers (NSCLC) that could detect targetable oncogenic drivers and resistance mutations in patients where tissue biopsy failed to identify an actionable alteration.

PATIENTS AND METHODS

Plasma was prospectively collected from patients with advanced, progressive NSCLC. We carried out ultra-deep NGS using cfDNA extracted from plasma and matched white blood cells using a hybrid capture panel covering 37 lung cancer-related genes sequenced to 50 000× raw target coverage filtering somatic mutations attributable to clonal hematopoiesis. Clinical sensitivity and specificity for plasma detection of known oncogenic drivers were calculated and compared with tissue genotyping results. Orthogonal ddPCR validation was carried out in a subset of cases.

RESULTS

In 127 assessable patients, plasma NGS detected driver mutations with variant allele fractions ranging from 0.14% to 52%. Plasma ddPCR for EGFR or KRAS mutations revealed findings nearly identical to those of plasma NGS in 21 of 22 patients, with high concordance of variant allele fraction (r = 0.98). Blinded to tissue genotype, plasma NGS sensitivity for de novo plasma detection of known oncogenic drivers was 75% (68/91). Specificity of plasma NGS in those who were driver-negative by tissue NGS was 100% (19/19). In 17 patients with tumor tissue deemed insufficient for genotyping, plasma NGS identified four KRAS mutations. In 23 EGFR mutant cases with acquired resistance to targeted therapy, plasma NGS detected potential resistance mechanisms, including EGFR T790M and C797S mutations and ERBB2 amplification.

CONCLUSIONS

Ultra-deep plasma NGS with clonal hematopoiesis filtering resulted in de novo detection of targetable oncogenic drivers and resistance mechanisms in patients with NSCLC, including when tissue biopsy was inadequate for genotyping.

Radiotherapy in addition to radical surgery in rectal cancer: evidence for a dose-response effect favoring preoperative treatment

PURPOSE

This study explored the relationship between radiation dose and reduction in local recurrence rate after preoperative and postoperative radiotherapy in rectal cancer.

METHODS AND MATERIALS

All randomized trials initiated prior to 1988 comparing preoperative and postoperative radiotherapy with surgery alone or with each other were included. Local failure rates were available in 5626 randomized patients. The linear quadratic formula was used to compensate for different radiotherapy schedules.

RESULTS

For preoperative radiotherapy, a clear dose-response relationship could be established. For postoperative radiotherapy, the range of doses was narrow, and a dose-response relationship could not be demonstrated. At similar doses, preoperative radiotherapy appeared to be more efficient in reducing local failure rate than postoperative. The only trial comparing preoperative with postoperative radiotherapy confirms this notion. A 15-20 Gy higher dose may be required postoperatively than preoperatively to reach similar efficacy. Neither approach alone significantly influences survival, although it is likely that a small survival benefit may be seen after preoperative radiotherapy.

CONCLUSIONS

The information from the entire randomized experience suggests that preoperative radiotherapy may be more dose efficient than postoperative radiotherapy.

Capecitabine can induce acute coronary syndrome similar to 5-fluorouracil

Capecitabine is a member of a new class of oral fluoropyrimidines. It is a 5-fluorouracil (5-FU) prodrug, activated by a series of enzymes. Activation has been demonstrated to occur preferentially in tumor tissue, which may explain the favorable balance of efficacy and toxicity of this drug. Cardiotoxicity, a rare but potentially serious adverse effect of 5-FU, has not been reported for capecitabine to date. Here we report a patient who experienced a severe and prolonged acute coronary syndrome during treatment with capecitabine. He had previously developed similar symptoms during treatment with infusional 5-FU. Capecitabine should thus be considered an agent with cardiotoxic potential. This adverse effect should be specifically monitored in all patients treated with capecitabine. Patients with symptoms suggestive of cardiotoxicity during previous treatment with a fluoropyrimidine should not be treated with capecitabine.

Reduction of the severe sepsis or septic shock associated mortality by reinforcement of the recommendations bundle: a multicenter study

INTRODUCTION

We determined whether the implementation of a bundle of 10 recommendations leads to the reduction of mortality in ICU patients with severe sepsis or septic shock.

METHODS

All patients with severe sepsis or septic shock during two consecutive phases: a 6-month quality control period (observational) and secondly a 6-month intervention period based on the implementation of a bundle of 10 recommendations adapted from the Surviving Sepsis Campaign guidelines (initial bacteriological samples and initiating antibiotics, measurement of arterial lactate, volume expansion > or =20 ml/kg, targeted mean arterial pressure > or =65 mmHg and the assessments of central venous pressure and Scv(O2); glucose control, low doses of corticosteroids, a tidal volume < or =8 ml/kg in mechanically ventilated patients with ALI; adequate use of recombinant human activated protein C) were evaluated in 15 ICUs. The primary endpoint was the 28-day mortality rate and the secondary endpoint was the compliance with the recommendations of the care bundle.

MEASUREMENT AND RESULTS

Four hundred and forty-five patients (230 and 215 in the observational and intervention periods, respectively) were included. In the two periods, the patients had similar characteristics. The 28-day mortality rate significantly decreased from 40% in the observational period to 27% in the intervention period (P=0.02). According to each recommendation, compliance with the care bundle was achieved in 9 to 100% of patients.

CONCLUSION

The implementation of a care bundle adapted from the Surviving Sepsis Campaign guidelines decreases the 28-day mortality rate in patients with severe sepsis and/or septic shock.

Morphologic and histochemical studies on the differing radiosensitivity of ductular and acinar cells of the rat submandibular gland

The submandibular glands of male rats were exposed to 50 Gy X-irradiation as a single dose, with or without pre-treatment with either alpha-adrenergic agonists (noradrenaline, phenylephrine) or a cholinergic antagonist (atropine). The effects were analyzed by morphometric, cytochemical and biophysical methods. When X-irradiated without drug pre-treatment, many serous epithelial cells of the intralobular convoluted ducts displayed morphologic evidence of irreversible radiation damage, in contrast to neighbouring mucous and other cells which were unaffected. The effect was maximal 96 h after irradiation. Serous cells from animals irradiated after pre-treatment with atropine showed much more wide-spread injury than those of animals exposed to X-irradiation only. In contrast , serous cells suffered considerably less damage if their secretory granules had been depleted 1 or 2 h before irradiation with either noradrenaline or phenylephrine. Other epithelial cells showed no modulation of their slight radioresponsiveness by these drugs. The observations were substantiated by morphometry of three cell types: (a) mucous cells, (b) non-granulated serous and intralobular striated duct cells, and (c) granulated serous cells. The findings suggest that the striking radiosensitivity of salivary gland serous epithelial cells is linked to their content of secretory granules. These granules are rich in heavy metals, as demonstrated cytochemically with the sulphide silver method (SSM). Using particle-induced X-ray emission ( PIXE ) spectroscopy, the principal metals were shown to be Zn, Mn and Fe. It is conceivable that membranes which enclose organelles rich in metals with the ability to form redox systems (e.g. Fe2+ in equilibrium Fe3+) show enhanced sensitivity to radiation damage due to the metal-catalyzed induction of lipid peroxidation by ionizing radiation. Disruption of secretory granules would be expected to release lytic enzymes into the cell sap, resulting in autolysis. This hypothesis is supported by the findings that atropine--which increases the number of granulated serous cells--enhances radiosensitivity, while noradrenaline and phenylephrine--which cause degranulation of serous cells--decrease radiosensitivity.

Quantitative 1H-magnetic resonance spectroscopy of human brain: Influence of composition and parameterization of the basis set in linear combination model-fitting

Localized short-echo-time (1)H-MR spectra of human brain contain contributions of many low-molecular-weight metabolites and baseline contributions of macromolecules. Two approaches to model such spectra are compared and the data acquisition sequence, optimized for reproducibility, is presented. Modeling relies on prior knowledge constraints and linear combination of metabolite spectra. Investigated was what can be gained by basis parameterization, i.e., description of basis spectra as sums of parametric lineshapes. Effects of basis composition and addition of experimentally measured macromolecular baselines were investigated also. Both fitting methods yielded quantitatively similar values, model deviations, error estimates, and reproducibility in the evaluation of 64 spectra of human gray and white matter from 40 subjects. Major advantages of parameterized basis functions are the possibilities to evaluate fitting parameters separately, to treat subgroup spectra as independent moieties, and to incorporate deviations from straightforward metabolite models. It was found that most of the 22 basis metabolites used may provide meaningful data when comparing patient cohorts. In individual spectra, sums of closely related metabolites are often more meaningful. Inclusion of a macromolecular basis component leads to relatively small, but significantly different tissue content for most metabolites. It provides a means to quantitate baseline contributions that may contain crucial clinical information.

Population-based data from the Swedish Colon Cancer Registry

BACKGROUND

Evaluating the external validity of clinical trials requires knowledge not only of the study population but also of a relevant reference population. The main aim of this study was to present data from a large, contemporary, population-based cohort of patients with colonic cancer.

METHODS

Data on patients diagnosed between 2007 and 2011 were extracted from the Swedish Colon Cancer Registry. The data, registered prospectively in a national population of almost 10 million, included over 99 per cent of all diagnosed adenocarcinomas of the colon.

RESULTS

This analysis included 18,889 patients with 19,526 tumours (3·0 per cent had synchronous tumours). The sex distribution was fairly equal, and the median age was 74·1 (interquartile range 65-81) years. The overall and relative (cancer-specific) survival rates after 3 years were 62·7 and 71·4 per cent respectively. Some 88·0 per cent of the patients were operated on, and 83·8 per cent had tumours resected. Median blood loss during bowel resection was 200 (mean 311) ml, and the median operating time was 160 min; 5·6 per cent of the procedures were laparoscopic. Preoperative chemotherapy was administered to 2·1 per cent of patients; postoperative chemotherapy was planned in 90·1 per cent of fit patients aged less than 75 years with stage III disease. In patients operated on in an emergency setting (21·5 per cent), the preoperative evaluation was less extensive, the proportion of R0 resections was lower, and the outcomes were poorer, in both the short and long term.

CONCLUSION

These population-based data represent good-quality reference points.

4D-MR flow analysis in patients after repair for tetralogy of Fallot

OBJECTIVES

Comprehensive analysis of haemodynamics by 3D flow visualisation and retrospective flow quantification in patients after repair of tetralogy of Fallot (TOF).

METHODS

Time-resolved flow-sensitive 4D MRI (spatial resolution ~ 2.5 mm, temporal resolution = 38.4 ms) was acquired in ten patients after repair of TOF and in four healthy controls. Data analysis included the evaluation of haemodynamics in the aorta, the pulmonary trunk (TP) and left (lPA) and right (rPA) pulmonary arteries by 3D blood flow visualisation using particle traces, and quantitative measurements of flow velocity.

RESULTS

3D visualisation of whole heart haemodynamics provided a comprehensive overview on flow pattern changes in TOF patients, mainly alterations in flow velocity, retrograde flow and pathological vortices. There was consistently higher blood flow in the rPA of the patients (rPA/lPA flow ratio: 2.6 ± 2.5 vs. 1.1 ± 0.1 in controls). Systolic peak velocity in the TP was higher in patients (1.9 m/s ± 0.7 m/s) than controls (0.9 m/s ± 0.1 m/s).

CONCLUSIONS

4D flow-sensitive MRI permits the comprehensive evaluation of blood flow characteristics in patients after repair of TOF. Altered flow patterns for different surgical techniques in the small patient cohort may indicate its value for patient monitoring and potentially identifying optimal surgical strategies.

Potential advantages of protons over conventional radiation beams for paraspinal tumours

BACKGROUND AND PURPOSE

Conformal treatment planning with megavoltage X-rays and protons was studied in an attempt to determine if there are advantage of boost therapy with protons instead of X-rays for a patient with a tumour growing around the cervical spinal cord.

MATERIALS AND METHODS

A patient with a Ewing sarcoma was selected for the model study. The proton boost plan was realised with a six beam patched technique. Several X-ray boost techniques were planned, some not yet practically realisable. The techniques giving the best dose distributions and the best tumour control probabilities in the absence of significant late toxicity were looked for. The boost techniques were added to two large lateral X-ray beams covering the planning target volume (PTV) and the main risk organ, the spinal cord. The evaluation was made with two biological models, i.e. the tumour control probability (TCP) model, proposed by Webb and Nahum (Webb, S. and Nahum, A.E. A model for calculating tumour control probability in radiotherapy including the effect of inhomogeneous distributions of dose and clonogenic cell density. Phys. Med. Biol. 38: 653-666, 1993), and the normal tissue complication probability (NTCP) model, first derived by Lyman (Lyman, J.T. Complication probability as assessed from dose-volume histograms. Radiat. Res. 104: s13-s19, 1985).

RESULTS

The comparison showed small but clear advantages of protons for the boost. At 1% NTCP in the spinal cord, the calculated TCP was on average 5% higher. However, depending on the values of the parameters chosen in the biological models, the gain for protons varied from 0-10%. The smallest gains were seen in radiosensitive tumours for which the TCP was close to 100% with any of the techniques and in radioresistant tumours for which neither technique resulted in any appreciable probability of local cure.

CONCLUSION

Protons appear to have therapeutic advantages over conventional radiotherapy in tumours with relatively high radiosensitivity situated close to the spinal cord.

Acute lumbosacral plexopathy during and after preoperative radiotherapy of rectal adenocarcinoma

The benefit of preoperative radiotherapy of adenocarcinoma of the rectum with respect to a reduced local recurrence rate and an improved survival should be weighed against adverse effects. For 14 years a three-beam, isocentric technique was employed at our hospital to deliver five fractions (5.0 or 5.1 Gy), over 5 or 7 days preoperatively, to patients with rectal cancer which was considered primarily resectable. The adverse effects of the radiotherapy were few, but acute pain and subacute neurological symptoms and signs did occur. An apparent increase in the frequency of these symptoms/signs was noted during 1993. The pain and neurological symptoms are described in case reports and the individual treatments are reviewed. The three-beam technique was analyzed in detail with individual, CT-based, three-dimensional dose-planning and dose distributions in the vicinity of the lumbar nerve plexus are presented. The major result of this analysis showed that technical errors could be excluded, that human errors were unlikely, and that the culprit probably was an unexpected sensitivity to marginal changes in the daily dose and unknown or unexpected radiosensitizing effects of concurrent diseases or medication.

Methods and reproducibility of cardiac/respiratory double-triggered (1)H-MR spectroscopy of the human heart

Localized (1)H-MR spectroscopy is sensitive to motion and has mostly been applied to the brain. For the human heart, cardiac and respiratory motion lead to displacements on the order of the localized voxel and lead to substantial variations of voxel content, lineshape, water suppression, and signal phase and amplitude. Combined respiratory and cardiac double triggering can avoid these complications to a large extent. Three methods of double triggering are evaluated, with reproducibility established in nine subjects for a method based on respiratory modulation of the ECG amplitude and a visual feedback mechanism. Quantitated with respect to water, within-subject reproducibilities for this setup were 9% for trimethylammonium compounds, 10% for creatine/phosphocreatine, and 13% for lipids. ANOVA showed significant differences between subjects which may relate to natural variability between subjects or exact location within the heart. Unresolved issues for this technique are its susceptibility to precise placement of ECG electrodes and the reasons for failure in 20% of examination. With this technique it is possible to investigate open questions in cardiac pathophysiology, such as the creatine content in chronic heart disease. Variants of this triggering method may also improve cardiovascular MRI methods relying on data acquired in several heartbeats. Magn Reson Med 42:903-910, 1999.

Restoration of electrophysiological signals distorted by inductive effects of magnetic field gradients during MR sequences

A generally applicable method for almost complete suppression of signal artifacts on electrophysiological signals caused by B0-gradient switching (gradient noise) is presented. The method is demonstrated for electrocardiograms (ECGs) but can also be used for other electrophysiological signals. It takes advantage of the fact that under certain conditions, the effect of switching the B0-field gradient upon an electrophysiological signal can be modeled as a linear time-invariant system and fully characterized by pulse response functions. It is shown how the system's pulse response functions of the X, Y, and Z gradients can be determined and how gradient noise can be eliminated efficiently. The elimination of gradient noise by the proposed method causes in the current arrangement a constant delay of 128 msec, which is acceptable for patient monitoring and magnetic resonance sequence triggering.

Effects of lysophospholipid supplementation to lower nutrient diets on growth performance, intestinal morphology, and blood metabolites in broiler chickens

The purpose of this research was to investigate the effects of dietary lysophospholipid (LPL) supplementation on low-energy, crude protein, and selected amino acids on growth performance, intestinal morphology, blood metabolites, inflammatory response, and carcass traits in broiler chickens. A total of 300 one-day-old male chicks (Ross 308) were assigned to 5 treatments, with 6 replications of 10 birds each in a completely randomized design. The 5 treatments were: positive control (PC) without LPL supplementation and adequate in all nutrients, negative control (NC) without LPL, and reduced 150 kcal/kg of metabolizable energy and reduced 5 to 6% of crude protein and selected amino acids including Lys, Met, Thr, and Trp in a calculated amount relative to the PC, NC + 0.05% LPL (LPL05), NC + 0.10% LPL (LPL10), and NC + 0.15% LPL (LPL15). Feeding LPL linearly improved growth performance, feed conversion ratio, ether extract, and protein digestibility. LPL supplementation on low-energy and nitrogenous diets showed significant enhancements in metabolic profiles of blood glucose, protein utilization, and immune system functions. These improvements influenced carcass composition, especially in relative weights of pancreas and breast muscle. In contrast, LPL addition showed no significant effects on relative weights of immune organs, gizzard, and abdominal fat. The NC birds were more susceptible to inflammation via modulating the secretion of interleukin-1 (IL-1) and increasing crypt depth in the jejunal and duodenal segments. However, the inclusion of 0.05% LPL to the NC diet could alleviate inflammation with increased jejunal villi height, ratio of villi height to crypt depth, and decreased IL-1 level. Overall, LPL promotes growth performance, nutrient utilization, gut health, anti-inflammation, and muscle yields when applied to diets of broiler chickens with lower levels of energy, crude protein, and selected amino acids.

How to preoxygenate in operative room: healthy subjects and situations "at risk"

Intubation is one of the most common procedures performed in operative rooms. It can be associated with life-threatening complications when difficult airway access occurs, in patients who cannot tolerate even a slight hypoxemia or when performed in patients at risk of oxygen desaturation during intubation, as obese, critically-ill and pregnant patients. To improve intubation safety, preoxygenation is a major technique, extending the duration of safe apnoea, defined as the time until a patient reaches an arterial saturation level of 88% to 90%, to allow for placement of a definitive airway. Preoxygenation consists in increasing the lung stores of oxygen, located in the functional residual capacity, and helps preventing hypoxia that may occur during intubation attempts. Obese, critically-ill and pregnant patients are especially at risk of reduced effectiveness of preoxygenation because of pathophysiological modifications (reduced functional residual capacity (FRC), increased risk of atelectasis, shunt). Three minutes tidal volume breathing or 3-8 vital capacities are recommended in general population, mostly allowing achieving a 90% end-tidal oxygen level. Recent studies have indicated that in order to maximize the value of preoxygenation (i.e, oxygenation stores) obese and critically-ill patients can benefit from the combination of breathing 100% oxygen and non-invasive positive pressure ventilation (NIV) with end-expiratory positive pressure (PEEP) in the proclive position (Trendelenburg reverse). Recruitment manoeuvres may be of interest immediately after intubation to limit the risk of lung derecruitment. Further studies are needed in the field of preoxygenation in pregnant women.

Crystal structure of human macrophage elastase (MMP-12) in complex with a hydroxamic acid inhibitor

Human macrophage elastase (MMP-12) is a member of the family of matrix metalloproteinases (MMPs) that plays, like other members of the family, an important role in inflammatory processes contributing to tissue remodelling and destruction. In particular, a prominent role of MMP-12 in the destruction of elastin in the lung alveolar wall and the pathogenesis of emphysema has been suggested. It is therefore an attractive therapeutic target. We describe here the crystal structure of the catalytic domain of MMP-12 in complex with a hydroxamic acid inhibitor, CGS27023A. MMP-12 adopts the typical MMP fold and binds a structural zinc ion and three calcium ions in addition to the catalytic zinc ion. The enzyme structure shows an ordered N terminus close to the active site that is identical in conformation with the superactivated form of MMP-8. The S1'-specificity pocket is large and extends into a channel through the protein, which puts MMP-12 into the class of MMPs 3, 8 and 13 with large and open specificity pockets. The two crystallographically independent molecules adopt different conformations of the S1'-loop and its neighbouring loop due to differing crystal packing environments, suggesting that flexibility or the possibility of structural adjustments of these loop segments are intrinsic features of the MMP-12 structure and probably a common feature for all MMPs. The inhibitor binds in a bidentate fashion to the catalytic zinc ion. Its polar groups form hydrogen bonds in a substrate-like manner with beta-strand sIV of the enzyme, while the hydrophobic substituents are either positioned on the protein surface and are solvent-exposed or fill the upper part of the specificity pocket. The present structure enables us to aid the design of potent and selective inhibitors for MMP-12.

Progression and NSAID-induced apoptosis in malignant melanomas are independent of cyclooxygenase II

Cyclooxygenase-II (Cox-II) overexpression is involved in the progression of various subtypes of cancer. We investigated the significance of Cox-II in the progression of malignant melanomas (MMs). Using immunohistology we determined that Cox-II is not expressed in 70 benign and malignant melanocytic tumours. Basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) were also analysed as controls: the BCCs were consistently Cox-II negative (n = 11), whereas the SCCs showed moderate to strong Cox-II expression in 53% (n = 17). Reverse transcription-polymerase chain reaction and Western blotting of MM cell lines and MM tissues confirmed the lack of Cox-II expression in MM. However, in vitro the Cox-inhibiting non-steroidal anti-inflammatory drug (NSAID) sulindac sulphide (SIS) was significantly more effective in inducing apoptosis than sulindac sulphone (SOS), a derivative with a negligible effect on Cox (P < 0.01). The SIS doses needed for the induction of apoptosis were not significantly different in MM cell lines versus a Cox-II-positive colon carcinoma cell line (HT29). Furthermore, add-back experiments with high doses of the prostaglandins PGE2 and PGF2beta, major Cox-II products, did not abrogate this effect. We conclude that Cox-II expression is not involved in the progression of MM, and NSAID-induced apoptosis in MM cell lines seems to follow pathways independent of Cox-II. Nevertheless, Cox-II inhibitors are still candidates for therapy, though they act via an unknown mechanism.

Age at first birth, parity and risk of breast cancer in a Swedish population

A case-control study was conducted over a period of 11 months in an area containing one-third of the Swedish population. One thousand and one patients participated, constituting 94% of all women newly diagnosed as having breast cancer within the area. They were compared with 1,001 age-matched, non-hospitalized controls without breast cancer, selected by paired sampling from a population register. The risk of breast cancer was slightly, but significantly, related to parity, the standardized relative risk (SRR) being 1.35 for nulliparous women as compared to ever parous. In the different parity groups a risk significantly lower than that for nulliparous women was found only for women with more than 2 children (SRR = 0.59) but the trend with parity was highly significant (P less than 0.001). Age at first birth was not found to be an important risk factor for breast cancer. SRR was lower than for nulliparous women in all groups of women with their first birth before the age of 35 years, but the difference was significant (P less than 0.05) only for those with the first birth between 20 and 24 (SSR = 0.69) and 25 and 29 (SRR = 0.69) years of age. The trend with age at first birth (P less than 0.05) disappeared after stratification for parity, suggesting that it was a confounding factor.

Cardiac gated MR imaging of cerebrospinal fluid flow

This is a preliminary investigation of the cerebrospinal fluid (CSF) spaces using cardiac gated magnetic resonance imaging. A variation of intensity of the signal from the cerebral aqueduct is demonstrated during the cardiac cycle. The pattern of this variation suggests pulsatile CSF flow. Calculations that have been verified by phantom measurements show that CSF flow rates less than 1 mm/s may be detectable. Magnetic resonance may therefore offer a new method for the demonstration and measurement of CSF flow.

Comparative treatment planning between proton and x-ray therapy in esophageal cancer

PURPOSE

Conformal treatment planning with megavoltage x-rays and protons for five patients with esophageal cancer has been studied in an attempt to determine if there are advantages of using protons instead of x-rays.

METHODS AND MATERIALS

For each of the five patients, two different proton plans, one x-ray plan, and one mixed plan with x-rays and protons were made. A three-dimensional treatment planning system, TMS, was used. The evaluation of the different plans was made by applying the tumor control probability (TCP) model proposed by Nahum and Webb and the normal tissue complication (NTCP) model proposed by Lyman on the dose distributions in terms of dose-volume histograms (DVHs).

RESULTS

The comparison shows advantages of using protons instead of x-rays for all five patients. The dose-limiting organs at risk are the spinal cord, the lungs, and the heart, but the proton plans also spare the kidneys better than the x-ray plan does. At 5% NTCP in any risk organ, the calculated mean TCP value for the five patients is increased by an average of 20%-units (from 2 to 23%-units) with the best proton plan compared with x-rays only. However, if we assume maximally a 1% risk in the spinal cord and a total NTCP for the two lungs of 100%, the mean TCP value for the five patients is increased from 6 to 49% with the best proton plan compared with x-rays only. The corresponding figure for the mixed plan is 27%. These gains are relatively insensitive to variations within reasonable limits in the biological parameters.

CONCLUSIONS

Protons appear to have clear therapeutic advantages over conventional external radiotherapy when treating esophageal carcinoma.

Tacrolimus and the risk of solid cancers after liver transplant: a dose effect relationship

Although increased rates of solid organ cancers have been reported following liver transplantation (LT), the impact of quantitative exposure to calcineurin inhibitors (CNI) remains unclear. We have therefore probed the relationship between the development of solid organ cancers following LT and the level of CNI exposure. This prospective single-center study was conducted between 1995 and 2008 and is based on 247 tacrolimus-treated liver transplant recipients who survived at least 1 year following surgery. The incidence of cancer was recorded, and the mean blood concentration of tacrolimus (TC) was determined at 1 and 3 years following LT. The study results indicate that 43 (17.4%) patients developed de novo solid cancers. Mean TC during the first year after LT was significantly higher in patients who developed solid organ tumors (10.3 ± 2.1 vs. 7.9 ± 1.9 ng/mL, p < 0.0001). Independent risks factors in multivariate analysis were tobacco consumption before LT (OR = 5.42; 95% CI [1.93-15.2], p = 0.0014) and mean annual TC during the first year after LT (p < 0.0001; OR = 2.01; 95% CI [1.57-2.59], p < 0.0001). Similar effects were observed in 216 patients who received tacrolimus continuously for ≥3 years. It appears therefore that CNI should be used with caution after LT, and that new immunosuppressive therapies could deliver significant clinical benefits in this regard.