Playing it safe can be a dangerous game

CO 2 response curves can be measured with a field-portable closed-loop photosynthesis system D.K. McDermitt T.J. Arkebauer 2 J.M. Norman 2 *, J.M. Welles 1 J.T. Davis 3 nd S.R. Rc T.M. Ball 2 mer 1 T.J. Arkebauer J.M. Welles S.R. Roerner 1 1 LI-COR, Inc., Lincoln, NE 68504, 2 Department of Agronomy, University of Nebraska, Lincoln, NE 68583, 3 Department of Forestry, Fisheries and Wildlife, University of Nebras!ka, Lincoln, NE 68583, and 4 Carnegie Institution of Washington, Stanford, CA 94305, U.S.A. Introduction Assimilation rate versus internal C0 2 re- sponse curves provide an important tool for assessing the efficiency and capacity of the photosynthetic system. Until recent- ly, measurement of C0 2 response curves was limited to laboratory studies, where elaborate gas exchange systems were available, or to mobile field laboratories. Here we report the use of a portable pho- tosynthesis system (LI-6200, LI-COR, Inc.) for measurement of response curves. The LI-6200 uses a closed-loop design in which varying C0 2 concentrations are pro- vided as the leaf removes C0 2 from the system. A typical measurement requires 10-25 min, depending upon chamber volume, leaf area and assimilation rate. Response curves measured on well- watered soybean and cotton with the LI- 6200 are compared to those measured * Present address: Department of Soils, University of Wis with a fully controlled steady state system. The effects of system leaks and control of leaf temperature are discussed. Materials and Methods Data of Fig. 1 were obtained on well-watered soybeans (Glycine max (L.) Merrill, cv Hobbit) grown in soil and 12 in pots in a temperature- controlled (27 ± 3°C) greenhouse in Lincoln, NE. Measurements were made on upper cano- py fully exposed leaves when the plants were in the early pod-filling stage. PAR was supplied by one Metalarc 400 W lamp and one Lucolux 400 W lamp in a single water-cooled luminaire (Sun- brella, Environmental Growth Chambers, Cha- grin Falls, OH). 1’he 1 I chamber of the LI-6200 was mounted on a tripod and placed at a dis- tance beneath the lamp which gave the desired light intensity. Radiation from the lamp was fil- tered with 1/4 in plexiglas and external air flow was provided by a small 110 V fan. Response curves were constructed as described in results. consin, Madison. Wl 53706. U.S.A. * Present address: Department of Soils, University of Wisconsin, Madison. Wl 53706. U.S.A. ** Present address: Systems Ecology Group, California State University, San Diego, CA 92t 20, U.S.A. Data of Figs. 2, 3 and 4 were obtained on vegetative soybeans grown in vermiculite and 8 in pots in the greenhouse at Carnegie Institu- tion, Stanford, CA. Measurements were made in an adjacent laboratory with the steady state system described by Ball (1987), and with the LI-6200. Relative humidity sensor and IRGA calibrations were carefully compared and checked prior to measurement. PAR (1200-1300 UMO I- M-2-S-1) was supplied by a high intensity projector lamp filtered with a dichroic mirror. Comparative measurements were made on the same leaflets. Data reported in Figs. 2, 3 and 4 were obtained with chamber relative humidity (RH) above 72% in both sys- tems. A response curve measured on soybean with the LI-6200 at ambient humidity (32%) deviated from a concomitant curve measured with the steady state system at about 70% RH. The pattern of photosynthesis rates and internal C0 2 concentrations suggested that stomatal conductance was not uniform across the leaf at the lower Playing it safe can be a dangerous game Playing it safe can be a dangerous game Bởi: Joe Tye “The play-it-safe pessimists of the world never accomplish much of anything, because they don’t look clearly and objectively at situations, they don’t recognize or believe in their own abilities, and they won’t stretch those abilities to overcome even the smallest amount of risk.” Benjamin Hoff: The Tao of Pooh In Ken Kesey’s masterful novel One Flew Over the Cuckoo’s Nest, it didn’t take long at all for Randall Patrick McMurphy to realize that Billy and some of the other nuthouse inmates weren’t crazy at all – they were scared to death and it was easier for them to pretend to be mentally ill so they could stay in a place where they did not have to face the realities and the responsibilities of the real world If you’ve ever been to Key West you have no doubt visited Last Flight Out, a shop owned by my good friend Clay Greager Every morning since my first stop there in 1996 I’ve had my coffee in a Last Flight Out mug with this poem by Elise Franzetta emblazoned upon it: Courage What are the fearsfrom which you run? What are the obstaclesto overcome? What is the pathyou’d like to take? What are the changesyou’d like to make? Where would you go? What would you do? If every windowwas open to you? 1/2 Playing it safe can be a dangerous game Do you have the couragewithout any doubt…to reach for your dreamstake your Last Flight Out? Great questions, these 2/2 RESEARCH Open Access Density of CD4(+) and CD8(+) T lymphocytes in biopsy samples can be a predictor of pathological response to chemoradiotherapy (CRT) for rectal cancer Koji Yasuda, Takako Nirei, Eiji Sunami, Hirokazu Nagawa and Joji Kitayama * Abstract Background: Although preoperative radiotherapy (RT) is widely used as the initial treatment for locally advanced rectal cancer (RC) in the neoadjuvant setting, factors determining clinical response have not been adequately defined. Radiosensitivity has recently been shown to be greatly affected by immune function of the host. Methods: In 48 cases of advanced RC, we retrospectively examined the density of tumor infiltrating CD4(+) and CD8(+) T cells using immunohistochemical staining of biopsy samples before CRT, and examined the correlation with tumor response. Results: The numbers of both CD4(+) and CD8(+) tumor-infiltrating lymphocytes (TIL) in pre-CRT biopsy samples were strongly correlated with tumor reduction ratio evaluated by barium enema. Moreover, the densities of CD4(+) and CD8(+) TIL were significantly associated with histological grade after CRT. The density of CD8(+) TIL was an independent prognostic factor for achieving complete response after CRT. Conclusions: In RC patients, T lymphocyte-mediated immune reactions play an important role in tumor response to CRT, and the quantitative measurement of TIL in biopsy samples befo re CRT can be used as a predictor of the clinical effectiveness of CRT for advanced RC. Introduction Previous studies have demon strated that preoperative radiotherapy (RT) can produce down-staging in advanced rectal cancer (RC), resulting in longer survi- val, a reduced rate of postoperative local recurrence. Recently, adding chemotherapy to RT (CRT) has achieved even more favorable results [1-3]. Thus, pre- operative RT in the neoadjuvant setting is currently recognized as the standard treatment for locally advanced RC. However, in unresponsive cases, it may have disadvantages such as delaying surgery or immune suppression. Although many clinical factors [4,5], radiologic findings [6,7] and molecular markers [7-10] have been suggested to be related to therapeu- tic response, the clinical usefulness of these markers remains controversial, and thus identifying factors predicting the efficacy of neoadjuvant CRT is essential for decision-making in the management of patients with RC. Recent studies have demonstrated that radiosensitiv- ity is greatly affected by immune function of the host [11,12]. In fact, we recently showed that the circulat- ing lymphocyte count is an important parameter determining the clinical outcome of RC patients who undergoCRT[13].Thisfactinspiredustoevaluate the relation betwe en the response and the characteris- tics of tumor-infiltrating lymphocytes (TIL) in rectal tumors. In this study, we used immunohistochemical staining and examined the distribution and cell den- sity of CD4(+) and CD8(+) TIL in biopsy samples before the start of CRT. * Correspondence: kitayama-1SU@h.u-tokyo.ac.jp Department of Surgery, Division of Surgical Oncology, University of Tokyo, Japan Yasuda et al. Radiation Oncology 2011, 6:49 http://www.ro-journal.com/content/6/1/49 © 2011 Yasuda et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Common s Attribution Lice nse ( http://c reativecommons.or g/licenses/by/2.0), which permits unrestricted use, distribution, and re production in any medium, provided the original work is properly cited. Materials and methods Patients Forty eight consecutive patients with rectal adenocarci- noma who received preoperative chemoradiotherapy (CRT) between November 2005 and August 200 9 and following surgery in Tokyo University Hospital were included in this study. All the patients received a total dose of 50.4Gy radiation and concomitant 5-Fu-based chemotherapy. Among the 48 cases, 46 underwent total mesorectal excision at 6~8 week s after the end of BioMed Central Page 1 of 3 (page number not for citation purposes) Journal of Medical Case Reports Open Access Case report Retention of foreign body in the gut can be a sign of congenital obstructive anomaly: a case report Pravas Chandra Subudhi 1 , Shivaram Prasad Singh* 2 , Chudamani Meher 3 and Omprakash Agrawal 3 Address: 1 Department of Pediatric Surgery, SCB Medical College, Cuttack 753007, Orissa, India, 2 Department of Gastroenterology, SCB Medical College, Cuttack 753007, Orissa, India and 3 Beam Diagnostics, Cuttack 753001, Orissa, India Email: Pravas Chandra Subudhi - beam.diagnostics@gmail.com; Shivaram Prasad Singh* - sudhasingh@sify.com; Chudamani Meher - beam.diagnostics@gmail.com; Omprakash Agrawal - beam.diagnostics@gmail.com * Corresponding author Abstract Introduction: Small smooth objects that enter the gut nearly always pass uneventfully through the gastrointestinal tract. Retention of foreign objects may occur due to congenital obstructive anomaly of the gut. Case presentation: We report here a child who presented with features of small gut obstruction which were attributed to a foreign body impacted in the intestine. At surgery, an annular pancreas was detected and the foreign body was found to be lodged in the distended proximal duodenum. Conclusion: The reported case highlights the fact that an impacted radio-opaque foreign body in a child should warn the pediatrician to the possibility of an obstructive congenital anomaly. Introduction Small round or oval objects that enter the stomach nearly always pass uneventfully through the gastrointestinal tract without requiring intervention. The retention of foreign objects within the duodenum is suggestive of partial obstruction, usually of congenital origin [1-3]. We describe a child presenting with features of high intestinal obstruction where retention of such an object led to the discovery of congenital duodenal stenosis producing par- tial obstruction. Case presentation A 32-month-old boy presented with a history of intermit- tent vomiting over the previous 15 months. The vomitus was generally non-bilious but occasionally bilious. The parents also noticed intermittent distension of his abdo- men which subsided after vomiting. The symptoms seemed to commence after the child had swallowed a metallic pendant which was coin-shaped and about 12 mm in diameter; at the time of swallowing, the child was about 17 months old. He underwent repeated plain upright radiographs of the abdomen to localize the for- eign body and to determine whether it had been passed. However, these continued to detect the foreign body. The last plain radiograph (Figure 1) of his abdomen showed the foreign body to be located in the right lower quadrant and it was surmised that the intestinal obstruction was due to impaction of the foreign body in the region of the terminal ileum. The child's parents were therefore advised that their child needed to undergo surgery for relief of the obstruction. However, a review of the plain upright radio- graph of the abdomen showed the presence of a 'double Published: 9 September 2008 Journal of Medical Case Reports 2008, 2:293 doi:10.1186/1752-1947-2-293 Received: 16 December 2007 Accepted: 9 September 2008 This article is available from: http://www.jmedicalcasereports.com/content/2/1/293 © 2008 Subudhi et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0 ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Journal of Medical Case Reports 2008, 2:293 http://www.jmedicalcasereports.com/content/2/1/293 Page 2 of 3 (page number not for citation purposes) bubble sign', in addition to a few dilated loops of small bowel in the left upper quadrant. A pre-operative diagno- sis of duodenal obstruction was made with the possibility of Lu et al. Virology Journal 2010, 7:83 http://www.virologyj.com/content/7/1/83 Open Access RESEARCH BioMed Central © 2010 Lu et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attri- bution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Research Polyclonal antibody against the DPV UL46M protein can be a diagnostic candidate Liting Lu 1 , Anchun Cheng* 1,2,3 , Mingshu Wang* 1,2 , Jinfeng Jiang 1 , Dekang Zhu 1,2 , Renyong Jia 2 , Qihui Luo 2 , Fei Liu 2 , Zhengli Chen 2 , Xiaoyue Chen 1,2,3 and Jinlong Yang 2,4 Abstract Background: The duck plague virus (DPV) UL46 protein (VP11/12) is a 739-amino acid tegument protein encoded by the UL46 gene. We analyzed the amino acid sequence of UL46 using bioinformatics tools and defined the main antigenic domains to be between nucleotides 700-2,220 in the UL46 sequence. This region was designated UL46M. The DPV UL46 and UL46M genes were both expressed in Escherichia coli Rosetta (DE3) induced by isopropy1-β- D- thiogalactopyranoside (IPTG) following polymerase chain reaction (PCR) amplification and subcloning into the prokaryotic expression vector pET32a(+). The recombinant proteins were purified using a Ni-NTA spin column and used to generate the polyclonal antibody against UL46 and UL46M in New Zealand white rabbits. The titer was then tested using enzyme-linked immunosorbent assay (ELISA) and agar diffusion reaction, and the specificity was tested by western blot analysis. Subsequently, we established Dot-ELISA using the polyclonal antibody and applied it to DPV detection. Results: In our study, the DPV UL46M fusion protein, with a relative molecular mass of 79 kDa, was expressed in E. coli Rosetta (DE3). Expression of the full UL46 gene failed, which was consistent with the results from the bioinformatic analysis. The expressed product was directly purified using Ni-NTA spin column to prepare the polyclonal antibody against UL46M. The titer of the anti-UL46M antisera was over 1:819,200 as determined by ELISA and 1:8 by agar diffusion reaction. Dot-ELISA was used to detect DPV using a 1:60 dilution of anti-UL46M IgG and a 1:5,000 dilution of horseradish peroxidase (HRP)-labeled goat anti-rabbit IgG. Conclusions: The anti-UL46M polyclonal antibody reported here specifically identifies DPV, and therefore, it is a promising diagnostic tool for DPV detection in animals. UL46M and the anti-UL46M antibody can be used for further clinical examination and research of DPV. Background Duck plague virus (DPV) is a pantropic, generalized infection virus, which can induce an acute, septic, conta- gious, and lethal disease in ducks, geese, swans, and all members of the family Anatidae of the order anseri- formes. The mortality rate of infected adult ducks is up to 90%; therefore, DPV is considered one of the most severe blights in the waterfowl breeding industry worldwide [1]. The DPV genome is composed of linear, double- stranded DNA with 64.3% guanine-plus-cytosine con- tent, which is higher than any other reported avian her- pesvirus in the subfamily Alphaherpesvirinae [2]. Although DPV was previously grouped in the subfamily Alphaherpesvirinae, it was classified as an unassigned virus in the Herpesviridae family according to the Eighth International Committee of Taxonomy of Viruses [3-5]. However, the molecular characteristics of DPV remain largely unknown. Following the development of molecu- lar biology, the research has focused on the molecular biology of the etiological agent of DPV, especially its genome atlas and encoding proteins, rather than the gen- eration and distribution of the virus in its host, the con- struction and morphogenesis of DPV, and the prevention and diagnosis of DPV [6-11]. To date, studies on the genomic organization and nucleotide sequence of DPV lag behind Page 1 of 2 (page number not for citation purposes) Available online http://ccforum.com/content/12/2/125 Abstract Using recruitment manoeuvres in acute lung injury remains a controversial issue because no convincing outcome data support their general use, although many physiological studies have demonstrated beneficial effects on lung compliance, end-expiratory lung volume and gas exchange. One of the reasons why physiologically meaningful observations do not translate into clear clinical benefit could be the heterogeneity of the studied patient population. In patients with consolidated lungs and only limited potential for recruitment, manoeuvres might be harmful, whereas in patients with high potential for recruitment they might be helpful. However, when those populations are mixed any signal may be lost because of counteracting effects, depending on how the patient population was mixed. We do not currently have any simple tool that may readily be applied at the bedside to assess the recruitment potential in an individual patient, which would be a sine qua non for identifying a homogeneous population in a recruitment study. Therefore, the method presented by Jacob Koefeld-Nielsen and colleagues in the previous issue of Critical Care provides us with a simple method that could be used at the bedside to assess recruitment potential before the manoeuvre is applied. In the previous issue of Critical Care, Koefeld-Nielsen and colleagues [1] provide us with interesting experimental data regarding the question of how to predict response to a recruitment manoeuvre before applying it. They conducted an animal study (lavage-induced experimental lung injury) to test the hypothesis that parameters derived from the pressure- volume (PV) loop recorded before application of the lung recruitment manoeuvre (LRM) predict the effects of the LRM on gas exchange, respiratory system compliance (Crs) and changes in end-expiratory lung volume (EELV). The parameter derived from the PV loop was the maximal volume difference between the inspiratory and the expiratory limbs of the PV loop at a given pressure, indicating the maximal hysteresis area. This was expressed as a ratio of the total lung capacity, measured as the volume gained on the PV loop at 4 kPa airway pressure. Furthermore, they hypothesized that the volume difference between the inspiratory and expiratory limbs of the PV curve at a given pressure would correspond to the change in EELV after the LRM at the same pressure. Both hypotheses were validated in their well controlled experimental study design. Specifically, a maximal hysteresis/ total lung capacity ratio of 0.3 predicted improvement in Crs, EELV and gas exchange after the LRM. This easily applicable method provides a means to predict the potential for recruitment, which is of paramount importance to recruitment strategies in acute lung injury [2]. However, we do not have any convincing evidence that recruitment strategies improve clinical outcomes of patients with acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) [3-5], although many physiological studies could demonstrate a recruitment-induced increase in Crs, EELV and gas exchange (see [3,6]). Recruitment of lung volume is critical in ALI/ARDS, in which loss of aerated lung volume is an important pathophysiological factor that leads to intra- pulmonary shunting of blood, culminating in severe hypoxaemia [7]. Consequently, the effect of recruitment in the clinical setting is mostly assessed by determining the effect on gas exchange. However, computed tomography (CT) studies [5,8] indicate that dissociation between mechanical effects and the gas exchange effect of LRM can occur, rendering gas exchange a rather insensitive parameter with which to assess LRM. The reason for this dissociation is that gas exchange only improves when ventilation/perfusion ratios are affected concomitantly; specifically, ventilation must improve and perfusion must not diminish. However, .. .Playing it safe can be a dangerous game Do you have the couragewithout any doubt…to reach for your dreamstake your Last Flight Out? Great questions, these 2/2