From Johann to Maurice: Science and Expression in the Philosophical Praxis of Medicine

Phenomenology's return to lived experience and "to the things themselves" is often contrasted with the synthesized perspective of science and its "view from nowhere." The extensive use of neuropsychological case reports in Merleau-Ponty's Phenomenology of Perception, however, suggests that the relationship between phenomenology and science is more complex than a sheer opposition, and a fruitful one for the praxis of medicine. Here, I propose a new reading of how Merleau-Ponty justifies his use of Adhemar Gelb and Kurt Goldstein's reports on Johann Schneider for his phenomenology of embodied perception. I argue that for Merleau-Ponty these neuropsychological case reports represent a coherent deformation of the intercorporeally expressed existence of Schneider that through speech fall again onto the common ground of perception, thereby allowing Merleau-Ponty to understand, in the equivalent sense delivered by language, Schneider's total being and fundamental illness. I then discuss what Merleau-Ponty's method implies for a phenomenological praxis of medicine, and for the role of science in this praxis

Revitalization of Abandoned Biosand Filters

Although biosand filters (BSFs) have been implemented in over 55 countries to provide safe drinking water, the necessity of operating filters on a daily basis has raised questions about filter efficacy after a period of abandonment (e.g., due to travels away from home or school vacations when students/faculty are not present to use institutional filters every day). Presently, the safe recommendation for abandoned filters is to deconstruct and rebuild. An assessment of the effectiveness of revitalized BSFs was conducted on two full-scale concrete BSFs, two 5-gallon bucket BSFs, and two 2-gallon bucket BSFs that were abandoned for two years. The filters were revitalized by rehydration (as needed), swirl-and-dump sand cleaning, tubing disinfection, and flushing. The performance of the revitalized filters was compared to that of two newly built concrete filters by measuring influent and effluent levels of Escherichia coli, Cryptosporidium parvum oocysts, and turbidity. Influent water was collected from a local creek to provide adequate nutrients to support biolayer development and to emulate field use. The log removal of E. coli and C. parvum by each filter was calculated by testing the two subsequent effluents following each spike. In addition, turbidity of each influent and effluent was measured to determine percent reduction. Flow rates of the filters, as well as water quality measurements of influent and effluent water (i.e., conductivity, phosphates, ammonia, total nitrogen), were evaluated weekly. The data show that revitalized BSFs are comparable to newly built filters, simplifying the continued use of drinking water treatment systems in developing nations.https://preserve.lehigh.edu/undergrad-scholarship-freed-posters/1003/thumbnail.jp

Criteria for and Appropriateness of Renal Transplantation in Elderly Patients With End-Stage Renal Disease : A Literature Review and Position Statement on Behalf of the European Renal Association-European Dialysis and Transplant Association Descartes Working Group and European Renal Best Practice

During the last 20 years, waiting lists for renal transplantation (RT) have grown significantly older. However, elderly patients (ie ≥65 years of age) are still more rarely referred or accepted to waiting lists and, if enlisted, have less chances of actually receiving a kidney allograft, than younger counterparts. In this review, we looked at evidence for the benefits and risks of RT in the elderly trying to answer the following questions: Should RT be advocated for elderly patients? What should be the criteria to accept elderly patients on the waiting list for RT? What strategies might be used to increase the rate of RT in waitlisted elderly candidates? For selected elderly patients, RT was shown to be superior to dialysis in terms of patient survival. Virtually all guidelines recommend that patients should not be deemed ineligible for RT based on age alone, although a short life expectancy generally might preclude RT. Concerning the assessment of comorbidities in the elderly, special attention should be paid to cardiac evaluation and screening for malignancy. Comorbidity scores and frailty assessment scales might help the decision making on eligibility. Psychosocial issues should also be evaluated. To overcome the scarcity of organ donors, elderly RT candidates should be encouraged to consider expanded criteria donors and living donors, as alternatives to deceased standard criteria donors. It has been demonstrated that expanded criteria donor RT in patients 60 years or older is associated with higher survival rates than remaining on dialysis, whereas living donor RT is superior to all other options.Peer reviewe

Mast cells regulate CD4+ T-cell differentiation in the absence of antigen presentation

Producción CientíficaBackground: Given their unique capacity for antigen uptake, processing, and presentation, antigen-presenting cells (APCs) are critical for initiating and regulating innate and adaptive immune responses. We have previously shown the role of nicotinamide adenine dinucleotide (NAD+) in T-cell differentiation independently of the cytokine milieu, whereas the precise mechanisms remained unknown. Objective: The objective of this study is to further dissect the mechanism of actions of NAD+ and determine the effect of APCs on NAD+-mediated T-cell activation. Methods: Isolated dendritic cells and bone marrow–derived mast cells (MCs) were used to characterize the mechanisms of action of NAD+ on CD4+ T-cell fate in vitro. Furthermore, NAD+-mediated CD4+ T-cell differentiation was investigated in vivo by using wild-type C57BL/6, MC−/−, MHC class II−/−, Wiskott-Aldrich syndrome protein (WASP)−/−, 5C.C7 recombination-activating gene 2 (Rag2)−/−, and CD11b-DTR transgenic mice. Finally, we tested the physiologic effect of NAD+ on the systemic immune response in the context of Listeria monocytogenes infection. Results: Our in vivo and in vitro findings indicate that after NAD+ administration, MCs exclusively promote CD4+ T-cell differentiation, both in the absence of antigen and independently of major APCs. Moreover, we found that MCs mediated CD4+ T-cell differentiation independently of MHC II and T-cell receptor signaling machinery. More importantly, although treatment with NAD+ resulted in decreased MHC II expression on CD11c+ cells, MC-mediated CD4+ T-cell differentiation rendered mice resistant to administration of lethal doses of L monocytogenes. Conclusions: Collectively, our study unravels a novel cellular and molecular pathway that regulates innate and adaptive immunity through MCs exclusively and underscores the therapeutic potential of NAD+ in the context of primary immunodeficiencies and antimicrobial resistance.National Institutes of Health (grants R01NS073635 , R01MH110438 , R01HL096795 , U01HL126497 and R01AG039449)Instituto de Salud Carlos III (grant PI10/02 511)Fundación Ramón Areces (grant CIVP16A1843

An evidence-based framework for predicting the impact of differing autotroph-heterotroph thermal sensitivities on consumer-prey dynamics

Increased temperature accelerates vital rates, influencing microbial population and wider ecosystem dynamics, for example, the predicted increases in cyanobacterial blooms associated with global warming. However, heterotrophic and mixotrophic protists, which are dominant grazers of microalgae, may be more thermally sensitive than autotrophs, and thus prey could be suppressed as temperature rises. Theoretical and meta-analyses have begun to address this issue, but an appropriate framework linking experimental data with theory is lacking. Using ecophysiological data to develop a novel model structure, we provide the first validation of this thermal sensitivity hypothesis: increased temperature improves the consumer’s ability to control the autotrophic prey. Specifically, the model accounts for temperature effects on auto- and mixotrophs and ingestion, growth and mortality rates, using an ecologically and economically important system (cyanobacteria grazed by a mixotrophic flagellate). Once established, we show the model to be a good predictor of temperature impacts on consumer–prey dynamics by comparing simulations with microcosm observations. Then, through simulations, we indicate our conclusions remain valid, even with large changes in bottom-up factors (prey growth and carrying capacity). In conclusion, we show that rising temperature could, counterintuitively, reduce the propensity for microalgal blooms to occur and, critically, provide a novel model framework for needed, continued assessment

Body mass index and outcome in renal transplant recipients: a systematic review and meta-analysis

BACKGROUND: Whether overweight or obese end stage renal disease (ESRD) patients are suitable for renal transplantation (RT) is often debated. The objective of this review and meta-analysis was to systematically investigate the outcome of low versus high BMI recipients after RT. METHODS: Comprehensive searches were conducted in MEDLINE OvidSP, Web of Science, Google Scholar, Embase, and CENTRAL (the Cochrane Library 2014, issue 8). We reviewed four major guidelines that are available regarding (potential) RT recipients. The methodology was in accordance with the Cochrane Handbook for Systematic Reviews of Interventions and written based on the PRISMA statement. The quality assessment of studies was performed by using the GRADE tool. A meta-analysis was performed using Review Manager 5.3. Random-effects models were used. RESULTS: After identifying 5,526 studies addressing this topic, 56 studies were included. We extracted data for 37 outcome measures (including data of more than 209,000 RT recipients), of which 26 could be meta-analysed. The following outcome measures demonstrated significant differences in favour of low BMI (<30) recipients: mortality (RR = 1.52), delayed graft function (RR = 1.52), acute rejection (RR = 1.17), 1-, 2-, and 3-year graft survival (RR = 0.97, 0.95, and 0.97), 1-, 2-, and 3-year patient survival (RR = 0.99, 0.99, and 0.99), wound infection and dehiscence (RR = 3.13 and 4.85), NODAT (RR = 2.24), length of hospital stay (2.31 days), operation duration (0.77 hours), hypertension (RR = 1.35), and incisional hernia (RR = 2.72). However, patient survival expressed in hazard ratios was in significant favour of high BMI recipients. Differences in other outcome parameters were not significant. CONCLUSIONS: Several of the pooled outcome measurements show significant benefits for ‘low’ BMI (<30) recipients. Therefore, we postulate that ESRD patients with a BMI >30 preferably should lose weight prior to RT. If this cannot be achieved with common measures, in morbidly obese RT candidates, bariatric surgery could be considered. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12916-015-0340-5) contains supplementary material, which is available to authorized users

Strategies of zooplanktivory shape the dynamics and diversity of littoral plankton communities : a mesocosm approach

Planktivorous fish can exert strong top-down control on zooplankton communities. By incorporating different feeding strategies, from selective particulate feeding to cruising filter feeding, fish species target distinct prey. In this study, we investigated the effects of two species with different feeding strategies, the three-spined stickleback (Gasterosteus aculeatus (L.)) and roach (Rutilus rutilus (L.)), on a low-diversity brackish water zooplankton community using a 16-day mesocosm experiment. The experiment was conducted on a small-bodied spring zooplankton community in high-nutrient conditions, as well as a large-bodied summer community in low-nutrient conditions. Effects were highly dependent on the initial zooplankton community structure and hence seasonal variation. In a small-bodied community with high predation pressure and no dispersal or migration, the selective particulate-feeding stickleback depleted the zooplankton community and decreased its diversity more radically than the cruising filter-feeding roach. Cladocerans rather than copepods were efficiently removed by predation, and their removal caused altered patterns in rotifer abundance. In a large-bodied summer community with initial high taxonomic and functional diversity, predation pressure was lower and resource availability was high for omnivorous crustaceans preying on other zooplankton. In this community, predation maintained diversity, regardless of predator species. During both experimental periods, predation influenced the competitive relationship between the dominant calanoid copepods, and altered species composition and size structure of the zooplankton community. Changes also occurred to an extent at the level of nontarget prey, such as microzooplankton and rotifers, emphasizing the importance of subtle predation effects. We discuss our results in the context of the adaptive foraging mechanism and relate them to the natural littoral community.Peer reviewe