Adaptation at the output of the chemotaxis signalling pathway

In the bacterial chemotaxis network, receptor clusters process input1–3, and flagellar motors generate output4. Receptor and motor complexes are coupled by the diffusible protein CheY-P. Receptor output (the steady-state concentration of CheY-P) varies from cell to cell5. However, the motor is ultrasensitive, with a narrow [CheY-P] operating range6. How might the match between receptor output and motor input be optimized? Here we show that the motor can shift its operating range by changing its composition. The number of FliM subunits in the C-ring increases in response to a decrement in the concentration of CheY-P, increasing motor sensitivity. This shift in sensitivity explains the slow partial adaptation observed in mutants that lack the receptor methyltransferase and methylesterase7–8 and why motors exhibit signal-dependent FliM turnover9. Adaptive remodelling is likely to be a common feature in the operation of many molecular machines.Molecular and Cellular Biolog

How Physicians Draw Satisfaction and Overcome Barriers in their Practices: “It Sustains Me”

Objective Major reorganizations of medical practice today challenge physicians’ ability to deliver compassionate care. We sought to understand how physicians who completed an intensive faculty development program in medical humanism sustain their humanistic practices. Methods Program completers from 8 U.S. medical schools wrote reflections in answer to two open-ended questions addressing their personal motivations and the barriers that impeded their humanistic practice and teaching. Reflections were qualitatively analyzed using the constant comparative method. Results Sixty-eight physicians (74% response rate) submitted reflections. Motivating factors included: 1) identification with humanistic values; 2) providing care that they or their family would want; 3) connecting to patients; 4) passing on values through role modelling; 5) being in the moment. Inhibiting factors included: 1) time, 2) stress, 3) culture, and 4) episodic burnout. Conclusions Determination to live by one’s values, embedded within a strong professional identity, allowed study participants to alleviate, but not resolve, the barriers. Collaborative action to address organizational impediments was endorsed but found to be lacking. Practice implications Fostering fully mature professional development among physicians will require new skills and opportunities that reinforce time-honored values while simultaneously partnering with others to nurture, sustain and improve patient care by addressing system issues

Views of institutional leaders on maintaining humanism in today’s practice

Objective To explore leadership perspectives on how to maintain high quality efficient care that is also person-centered and humanistic. Methods The authors interviewed and collected narrative transcripts from a convenience sample of 32 institutional healthcare leaders at seven U.S. medical schools. The institutional leaders were asked to identify factors that either promoted or inhibited humanistic practice. A subset of authors used the constant comparative method to perform qualitative analysis of the interview transcripts. They reached thematic saturation by consensus on the major themes and illustrative examples after six conference calls. Results Institutional healthcare leaders supported vision statements, policies, organized educational and faculty development programs, role modeling including their own, and recognition of informal acts of kindness to promote and maintain humanistic patient-care. These measures were described individually rather than as components of a coordinated plan. Few healthcare leaders mentioned plans for organizational or systems changes to promote humanistic clinician-patient relationships. Conclusions Institutional leaders assisted clinicians in dealing with stressful practices in beneficial ways but fell short of envisaging systems approaches that improve practice organization to encourage humanistic care

A multicenter, prospective study of a new fully covered expandable metal biliary stent for the palliative treatment of malignant bile duct obstruction

Background and Study Aims. Endoscopic placement of self-expanding metal stents (SEMSs) is indicated for palliation of inoperable malignant biliary obstruction. A fully covered biliary SEMS (WallFlex Biliary RX Boston Scientific, Natick, USA) was assessed for palliation of extrahepatic malignant biliary obstruction. Patients and Methods. 58 patients were included in this prospective, multicenter series conducted under an FDA-approved IDE. Main outcome measurements included (1) absence of stent occlusion within six months or until death, whichever occurred first and (2) technical success, need for reintervention, bilirubin levels, stent patency, time to stent occlusion, and adverse events. Results. Technical success was achieved in 98% (57/58), with demonstrated acute removability in two patients. Adequate clinical palliation until completion of followup was achievedin 98% (54/55) of evaluable patients, with 1 reintervention due to stent obstruction after 142 days. Mean total bilirubin decreased from 8.9 mg/dL to 1.2 mg/dL at 1 month. Device-related adverse events were limited and included 2 cases of cholecystitis. One stent migrated following radiation therapy. Conclusions. The WallFlex Biliary fully covered stent yielded technically successful placement with uncomplicated acute removal where required, appropriate reduction in bilirubin levels, and low rates of stent migration and occlusion. This SEMS allows successful palliation of malignant extrahepatic biliary obstruction

Intervenir sobre la cultura organizacional: ¿qué aspectos se pueden considerar?

La cultura organizacional (co) es un macroconstructo que involucra una gran variedad de componentes y funciones organizacionales (Warner, 2014). Reyes y Moros (2018) señalan que tiene su origen en el estudio realizado en Hawthorne por Elton Mayo y otros investigadores de la Escuela de las Relaciones Humanas de la Administración, en el que buscaban identificar la influencia de las condiciones físicas y ambientales en el desempeño individual. Para Reyes y Moros (2018), la co se siguió desarrollando en los años setenta con Pettigrew, para ser entendida como un sistema de significados que tanto pública como colectivamente es aceptado para operar en un tiempo y por un grupo determinado. Los autores la definen como “… un sistema de significados compartidos por los miembros de la organización, los cuales son el resultado de una construcción social constituida a través de símbolos y como tal deben ser interpretados”1a edició

A Comparison of Amphotericin B Alone and Combined with Flucytosine in the Treatment of Cryptoccal Meningitis

Abstract We compared amphotericin B therapy for cryptococcal meningitis with a newer regimen containing both amphotericin B and flucytosine. In 50 patients with 51 courses of therapy adherent to the protocol, 27 courses were with amphotericin B and 24 with the combination. Even though the combination regimen was given for only six weeks and amphotericin B for 10 weeks, the combination cured or improved more patients (16 vs. 11), produced fewer failures or relapses (three vs. 11), more rapid sterilization of the cerebrospinal fluid (P\u3c0.001) and less nephrotoxicity (P\u3c0.05) than did amphotericin B alone. The number of deaths was the same (five) with each regimen. Adverse reactions to flucytosine occurred in 11 of 34 patients but were not life threatening. We conclude that combined flucytosine-amphoericin B therapy is the regimen of choice in cryptococcal meningitis. (N Engl J Med 301:126–131, 1979

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research