Post-exercise heart rate recovery and its speed are associated with resting-reactivity cardiovagal modulation in healthy women.

The present study sought to expand upon prior investigations of the relationship between post-exercise heart rate recovery (HRR) and cardiovagal resting-reactivity modulation. HRR from 1st to 5th min after maximal exercise test was correlated with a cardiovagal index of heart rate variability (SD1) at resting (supine and orthostatic positions) and its reactivity after the orthostatic stress test in 34 healthy women. Statistical analysis employed non-parametric tests with a p-value set at 5%. HRR, ∆%HRR, and coefficient of HRR (CHRR) at the 3rd and 5th min correlated with SD1 and SD1n (normalized units) in the supine position (rs = 0.36 to 0.47; p = < 0.01). From the 1st to 5th min, HRR, ∆%HRR, and CHRR correlated with SD1 and SD1n in the orthostatic position (rs = 0.29 to 0.47; p = ≤ 0.01 to 0.05), except for HRR at 5th min with SD1n (p = 0.06). Following the orthostatic stress test, HRR at 3rd and HRR, %∆HRR at 5th min correlated with ∆absSD1 (rs = 0.28 to 0.35; p = 0.02 to 0.05). All HRR measurements at 1st min correlated with ∆absSD1n (rs = 0.32 to 0.38; p = 0.01 to 0.03), and the CHRR at 1st min correlated with ∆%SD1(rs = 0.37; p = 0.01). After the sample was divided into high and low cardiovagal modulation subgroups, the subgroup with high modulation at rest (supine and orthostatic) and higher cardiovagal reactivity (reduction) showed faster HRR (p = ≤ 0.01 to 0.05; ES:0.37 to 0.50). HRR throughout the 1st to 5th min positively correlates with cardiovagal modulation in the orthostatic position, and the 3rd and 5th min positively correlate with cardiovagal modulation in both postures at rest. Faster HRR following the maximal exercise test is associated with high resting-reactivity cardiovagal modulation in healthy women.

Mitochondrial injury during normothermic regional perfusion (NRP) and hypothermic oxygenated perfusion (HOPE) in a rodent model of DCD liver transplantation.

BACKGROUND: Normothermic regional perfusion (NRP) and hypothermic-oxygenated-perfusion (HOPE), were both shown to improve outcomes after liver transplantation from donors after circulatory death (DCD). Comparative clinical and mechanistical studies are however lacking. METHODS: A rodent model of NRP and HOPE, both in the donor, was developed. Following asystolic donor warm ischemia time (DWIT), the abdominal compartment was perfused either with a donor-blood-based-perfusate at 37 °C (NRP) or with oxygenated Belzer-MPS at 10 °C (donor-HOPE) for 2 h. Livers were then procured and underwent 5 h static cold storage (CS), followed by transplantation. Un-perfused and HOPE-treated DCD-livers (after CS) and healthy livers (DBD) with direct implantation after NRP served as controls. Endpoints included the entire spectrum of ischemia-reperfusion-injury. FINDINGS: Healthy control livers (DBD) showed minimal signs of inflammation during 2 h NRP and achieved 100% posttransplant recipient survival. In contrast, DCD livers with 30 and 60 min DWIT suffered from greater mitochondrial injury and inflammation as measured by increased perfusate Lactate, FMN- and HMGB-1-levels with subsequent Toll-like-receptor activation during NRP. In contrast, donor-HOPE (instead of NRP) led to significantly less mitochondrial-complex-I-injury and inflammation. Results after donor-HOPE were comparable to ex-situ HOPE after CS. Most DCD-liver recipients survived when treated with one HOPE-technique (86%), compared to only 40% after NRP (p = 0.0053). Following a reduction of DWIT (15 min), DCD liver recipients achieved comparable survivals with NRP (80%). INTERPRETATION: High-risk DCD livers benefit more from HOPE-treatment, either immediately in the donor or after cold storage. Comparative prospective clinical studies are required to translate the results. FUNDING: Funding was provided by the Swiss National Science Foundation (grant no: 32003B-140776/1, 3200B-153012/1, 320030-189055/1, and 31IC30-166909) and supported by University Careggi (grant no 32003B-140776/1) and the OTT (grant No.: DRGT641/2019, cod.prog. 19CT03) and the Max Planck Society. Work in the A.G. laboratory was partially supported by the NIH R01NS112381 and R21NS125466 grants.

Observations and findings during the development of a subnormothermic/normothermic long-term ex vivo liver perfusion machine.

BACKGROUND: Ex situliver machine perfusion at subnormothermic/normothermic temperature isincreasingly applied in the field of transplantation to store and evaluateorgans on the machine prior transplantation. Currently, various perfusionconcepts are in clinical and preclinical applications. Over the last 6 years ina multidisciplinary team, a novel blood based perfusion technology wasdeveloped to keep a liver alive and metabolically active outside of the bodyfor at least one week. METHODS: Within thismanuscript, we present and compare three scenarios (Group 1, 2 and 3) we werefacing during our research and development (R&D) process, mainly linked tothe measurement of free hemoglobin and lactate in the blood based perfusate. Apartfrom their proven value in liver viability assessment (ex situ), these twoparameters are also helpful in R&D of a long-term liver perfusion machine and moreover supportive in the biomedical engineering process. RESULTS: Group 1 ("good" liver on the perfusion machine) represents the best liver clearance capacity for lactate and free hemoglobin wehave observed. In contrast to Group 2 ("poor" liver on the perfusion machine), that has shown the worst clearance capacity for free hemoglobin. Astonishingly,also for Group 2, lactate is cleared till the first day of perfusion andafterwards, rising lactate values are detected due to the poor quality of theliver. These two perfusate parametersclearly highlight the impact of the organ quality/viability on the perfusion process. Whereas Group 3 is a perfusion utilizing a blood loop only (without a liver). CONCLUSION: Knowing the feasible ranges (upper- and lower bound) and the courseover time of free hemoglobin and lactate is helpful to evaluate the quality ofthe organ perfusion itself and the maturity of the developed perfusion device. Freehemoglobin in the perfusate is linked to the rate of hemolysis that indicates how optimizing (gentle blood handling, minimizing hemolysis) the perfusion machine actually is. Generally, a reduced lactate clearancecapacity can be an indication for technical problems linked to the blood supplyof the liver and therefore helps to monitor the perfusion experiments.Moreover, the possibility is given to compare, evaluate and optimize developed liverperfusion systems based on the given ranges for these two parameters. Otherresearch groups can compare/quantify their perfusate (blood) parameters withthe ones in this manuscript. The presented data, findings and recommendations willfinally support other researchers in developing their own perfusion machine ormodifying commercially availableperfusion devices according to their needs.

An analog to digital converter controls bistable transfer competence development of a widespread bacterial integrative and conjugative element.

Conjugative transfer of the integrative and conjugative element ICEclc in Pseudomonas requires development of a transfer competence state in stationary phase, which arises only in 3-5% of individual cells. The mechanisms controlling this bistable switch between non-active and transfer competent cells have long remained enigmatic. Using a variety of genetic tools and epistasis experiments in P. putida, we uncovered an 'upstream' cascade of three consecutive transcription factor-nodes, which controls transfer competence initiation. One of the uncovered transcription factors (named BisR) is representative for a new regulator family. Initiation activates a feedback loop, controlled by a second hitherto unrecognized heteromeric transcription factor named BisDC. Stochastic modelling and experimental data demonstrated the feedback loop to act as a scalable converter of unimodal (population-wide or 'analog') input to bistable (subpopulation-specific or 'digital') output. The feedback loop further enables prolonged production of BisDC, which ensures expression of the 'downstream' functions mediating ICE transfer competence in activated cells. Phylogenetic analyses showed that the ICEclc regulatory constellation with BisR and BisDC is widespread among Gamma- and Beta-proteobacteria, including various pathogenic strains, highlighting its evolutionary conservation and prime importance to control the behaviour of this wide family of conjugative elements.

Mobile DNA elements are pieces of genetic material that can jump from one bacterium to another, and even across species. They are often useful to their host, for example carrying genes that allow bacteria to resist antibiotics. One example of bacterial mobile DNA is the ICEclc element. Usually, ICEclc sits passively within the bacterium's own DNA, but in a small number of cells, it takes over, hijacking its host to multiply and to get transferred to other bacteria. Cells that can pass on the elements cannot divide, and so this ability is ultimately harmful to individual bacteria. Carrying ICEclc can therefore be positive for a bacterium but passing it on is not in the cell's best interest. On the other hand, mobile DNAs like ICEclc have evolved to be disseminated as efficiently as possible. To shed more light on this tense relationship, Carraro et al. set out to identify the molecular mechanisms ICEclc deploys to control its host. Experiments using mutant bacteria revealed that for ICEclc to successfully take over the cell, a number of proteins needed to be produced in the correct order. In particular, a protein called BisDC triggers a mechanism to make more of itself, creating a self-reinforcing 'feedback loop'. Mathematical simulations of the feedback loop showed that it could result in two potential outcomes for the cell. In most of the 'virtual cells', ICEclc ultimately remained passive; however, in a few, ICEclc managed to take over its hosts. In this case, the feedback loop ensured that there was always enough BisDC to maintain ICEclc's control over the cell. Further analyses suggested that this feedback mechanism is also common in many other mobile DNA elements, including some that help bacteria to resist drugs. These results are an important contribution to understand how mobile DNAs manipulate their bacterial host in order to propagate and disperse. In the future, this knowledge could help develop new strategies to combat the spread of antibiotic resistance.

Quantitative chemical biosensing by bacterial chemotaxis in microfluidic chips.

Whole-cell bacterial bioreporters are proposed as alternatives to chemical analysis of, for example, pollutants in environmental compartments. Commonly based on reporter gene induction, bioreporters produce a detectable signal within 30 min to a few hours after exposure to the chemical target, which is impractical for applications aiming at a fast response. In an attempt to attain faster readout but maintain flexibility of chemical targeting, we explored the concept for quantitative chemical sensing by bacterial chemotaxis. Chemotaxis was quantified from enrichment of cells across a 600 µm-wide chemical gradient stabilized by parallel flow in a microfluidic chip, further supported by transport and chemotaxis steady state and kinetic modelling. As proof-of-concept, we quantified Escherichia coli chemotaxis towards serine, aspartate and methylaspartate as a function of attractant concentration and exposure time. E. coli chemotaxis enrichment increased sharply between 0 and 10 µM serine, before saturating at 100 µM. The chemotaxis accumulation rate was maximal at 10 µM serine, leading to observable cell enrichment within 5 min. The potential application for biosensing of environmental toxicants was investigated by quantifying chemotaxis of Cupriavidus pinatubonensis JMP134 towards the herbicide 2,4-dichlorophenoxyacetate. Our results show that bacterial chemotaxis can be quantified on a scale of minutes and may be used for developing faster bioreporter assays.

Pancreatitis crónica / Chronic pancreatitis

La pancreatitis crónica es una enfermedad multifactorial.Las mutaciones en el gen de la quimotripsina C pueden favorecerel desarrollo de pancreatitis crónica. El hábito defumar es un importante factor asociado al desarrollo y evoluciónde la pancreatitis crónica. Es necesario categorizarlos signos identificados en la ecoendoscopia a la hora dediagnosticar una pancreatitis crónica, ya que no todos tienenel mismo valor diagnóstico. La pancreatitis autoinmunitariatiene manifestaciones clínicas más variadas que lasdescritas inicialmente y varían según la población estudiada.Los criterios utilizados para el diagnóstico de la pancreatitisautoinmunitaria no son del todo precisos y su tratamientopuede requerir del uso de inmunomoduladores. El tratamientocon antioxidantes tiene efectos beneficiosos a largoplazo en pacientes con pancreatitis crónica. Algunas manifestacionesclínicas en pacientes con síndrome del intestinoirritable pueden tener su origen en una insuficiencia pancreáticano identificada. Un estudio con cápsula endoscópicamuestra que la fibrosis quística presenta signos de enteropatíaen el intestino delgado(AU)

Chronic pancreatitis is a multifactorial disease. Mutations inthe chymotrypsin C gene may encourage the development ofchronic pancreatitis. Smoking is an important factor in thedevelopment and progression of chronic pancreatitis. Thesigns identified in endoscopic ultrasound should be categorizedwhen diagnosing chronic pancreatitis, since not all havethe same diagnostic value. The clinical manifestations of autoimmunepancreatitis are more varied than initially describedand depend on the population studied. The criteria usedfor the diagnosis of autoimmune pancreatitis have not beenwell defined and treatment may require the use of immunomodulators.Antioxidant therapy has beneficial effects in thelong term in patients with chronic pancreatitis. Some clinicalmanifestations found in patients with irritable bowelsyndrome may be caused by unidentified pancreatic insufficiency.Capsule endoscopy shows that cystic fibrosis presentssigns of small bowel enteropathy(AU)

[Chronic pancreatitis]. / Pancreatitis crónica.

Chronic pancreatitis is a multifactorial disease. Mutations in the chymotrypsin C gene may encourage the development of chronic pancreatitis. Smoking is an important factor in the development and progression of chronic pancreatitis. The signs identified in endoscopic ultrasound should be categorized when diagnosing chronic pancreatitis, since not all have the same diagnostic value. The clinical manifestations of autoimmune pancreatitis are more varied than initially described and depend on the population studied. The criteria used for the diagnosis of autoimmune pancreatitis have not been well defined and treatment may require the use of immunomodulators. Antioxidant therapy has beneficial effects in the long term in patients with chronic pancreatitis. Some clinical manifestations found in patients with irritable bowel syndrome may be caused by unidentified pancreatic insufficiency. Capsule endoscopy shows that cystic fibrosis presents signs of small bowel enteropathy.

Pancreatitis crónica / Chronic pancreatitis

La etiopatogenia de la pancreatitis crónica no se conoce en profundidad. El hábito de fumar, la autoinmunidad y la presencia de mutaciones en genes específicos se han consolidado como factores etiológicos asociados importantes. La ecoendoscopia, con o sin aspiración-biopsia pancreática, se ha afianzado como una herramienta diagnóstica sensible y específica. En pacientes con pancreatitis crónica, el dolor abdominal puede ser un síntoma invalidante. La radioterapia antiinflamatoria puede mitigar los síntomas y evitar la aplicación de cirugía mutilante. En caso de insuficiencia pancreática, es importante optimizar de forma individual el tratamiento sustitutivo con enzimas pancreáticas. Las pancreatitis autoinmunes están infradiagnosticadas en Europa. El tratamiento con corticoides es muy efectivo, pero su interrupción conduce a recidivas frecuentes. En este contexto, el tratamiento de mantenimiento con azatioprina puede ser de utilidad (AU)

The etiopathogenesis of chronic pancreatitis is not well characterized. Smoking, autoimmunity, and the presence of mutations in specific genes have been demonstrated to be important associated etiological factors. Endoscopic ultrasonography, with or without pancreatic aspiration-biopsy, has good sensitivity and specificity. In patients with chronic pancreatitis, abdominal pain may be a crippling symptom. Antiinflammatory radiotherapy may mitigate the symptoms and avoid the use of mutilating surgery. In pancreatic failure, pancreatic enzyme replacement therapy should be optimized by individualizing the dose. Autoimmune forms of pancreatitis are under-diagnosed in Europe. Corticosteroid therapy is highly effective but its interruption leads to frequent recurrences; in this context maintenance therapy with azathioprine may be useful (AU)