A UV-C LED-based unit for continuous decontamination of the sheath fluid in a flow-cytometric cell sorter.

Aseptic cell sorting is challenging, especially when a flow-cytometric cell sorter is not operated in a sterile environment. The sheath fluid system of a cell sorter may be contaminated with germs such as bacteria, yeasts, viruses, or fungi. Thus, a regular chemical cleaning procedure is required to prepare a sorter for aseptic cell sorting by flushing the fluidic system. However, this procedure is time consuming, and most importantly, the researcher can never be sure that the cleaning process was successful. Here we present a method in which the sheath fluid of a cell sorter was decontaminated by irradiation with UV-C light using a flow-through principle. Using this principle, we were able to achieve a 5 log reduction of bacteria in the sheath fluid.

COVID-19 Vaccines and the Virtues.

From a moral point of view, what arguments are there for and against seeking COVID-19 vaccination? Can it be morally permissible to require (parts of) a population to receive a vaccine? The present paper adopts a perspective of virtue ethics and argues both that it is morally right for an individual virtuous moral agent to seek COVID-19 vaccination and for a virtuous ruler to impose mandatory vaccinations on her population. We begin by first presenting virtue ethics and the current vaccine controversy. Second, we examine whether a virtuous individual should get vaccinated. Third, we consider whether, from a moral point of view, it is right for a ruler to impose mandatory vaccinations on her citizens. Fourth, we answer some objections to our argument. Finally, we conclude that virtue ethical considerations warrant both the individual choice of getting vaccinated and mandatory vaccinations against COVID-19.

Multi-angle pulse shape detection of scattered light in flow cytometry for label-free cell cycle classification.

Flow cytometers are robust and ubiquitous tools of biomedical research, as they enable high-throughput fluorescence-based multi-parametric analysis and sorting of single cells. However, analysis is often constrained by the availability of detection reagents or functional changes of cells caused by fluorescent staining. Here, we introduce MAPS-FC (multi-angle pulse shape flow cytometry), an approach that measures angle- and time-resolved scattered light for high-throughput cell characterization to circumvent the constraints of conventional flow cytometry. In order to derive cell-specific properties from the acquired pulse shapes, we developed a data analysis procedure based on wavelet transform and k-means clustering. We analyzed cell cycle stages of Jurkat and HEK293 cells by MAPS-FC and were able to assign cells to the G1, S, and G2/M phases without the need for fluorescent labeling. The results were validated by DNA staining and by sorting and re-analysis of isolated G1, S, and G2/M populations. Our results demonstrate that MAPS-FC can be used to determine cell properties that are otherwise only accessible by invasive labeling. This approach is technically compatible with conventional flow cytometers and paves the way for label-free cell sorting.

COVID-19 calls for virtue ethics.

The global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or coronavirus disease 19 (COVID-19) has led to the imposition of severely restrictive measures by governments in the Western hemisphere. We feel a contrast between these measures and our freedom. This contrast, we argue, is a false perception. It only appears to us because we look at the issue through our contemporary moral philosophy of utilitarianism and an understanding of freedom as absence of constraints. Both these views can be substituted with more sophisticated alternatives, namely an ethics of virtue and a notion of freedom of the will. These offer a fuller picture of morality and enable us to cooperate with the current restrictions by consciously choosing to adhere to them instead of perceiving them as draconian and immoral. We ask whether we should collaborate with the restrictions and argue that considerations of virtue will lead to an affirmative answer. More broadly, virtue ethics permits to deal with the practical concerns about how an individual should behave during this pandemic, given the current lockdown measures or lack thereof. In section 1, we present how utilitarianism and a notion of freedom as negative liberty support the opposition to restrictive measures. In section 2, we outline an alternative based on an ethics of virtue and a more elaborated notion of free will. In the concluding section 3, we argue that considerations of virtue should guide the individual and public response to the emergency.

The Effects of Temperature and Ethanol on Proanthocyanidin Adsorption to Grape Cell Wall Material in the Presence of Anthocyanins.

The quantitative and qualitative impacts of anthocyanins on proanthocyanidin adsorption to grape-derived cell wall material were investigated in fifteen unique systems of varying temperatures, ethanol concentrations, and proanthocyanidin concentrations. Proanthocyanidin solutions were exposed to cell wall material and monitored for changes in concentration over 24 h. Increases in both temperature and ethanol resulted in a larger retention of proanthocyanidins in solution and typically faster adsorption kinetics. Analysis of the solution after exposure to cell wall revealed a significant reduction in the molecular weight of proanthocyanidins present in solution, suggesting that anthocyanins do not alter a previously described mechanism of preferentially binding large molecular weight molecules. Additionally, a reduction in polymeric pigment abundance was noted in most conditions, suggesting rapid formation of polymeric pigment in the model solution and preferential adsorption of the polymeric pigment to cell wall material. Compared to a previous study of proanthocyanidin adsorption in the absence of anthocyanins, a significantly larger percentage of proanthocyanidin material was lost via adsorption-up to 70% of available material. In a winemaking context, this may suggest a preferential loss of polymeric pigment via adsorption to cap cell wall material compared to non-pigmented proanthocyanidins and free anthocyanins.

A combined phenolic extraction and fermentation reactor engineering model for multiphase red wine fermentation.

Red wine production begins with a simultaneous fermentation and solid-phase extraction process. Red wine color and mouthfeel is the result of the extraction of phenolics from grape skins and seeds during fermentation, where extraction is a strong function of temperature and ethanol concentration. During fermentation, grape solids form a porous "cap" at the top of the fermentor, resulting in a heterogeneous fermentation system with significant temperature and concentration gradients. In this work, we present a spatial, time-variant reactor engineering model for phenolic extraction during red wine fermentation, incorporating fermentation kinetics, mass transfer, heat transfer, compressible fluid flow, and phenolic extraction kinetics. The temperature and ethanol concentration profiles predicted by this model allow for the calculation of phenolic extraction rates over the course of fermentation. Phenolic extraction predictions were validated against prior experimental data to good agreement and compared to a well-mixed model's predictions to show the utility of a spatial model over well-mixed models.

Heat-Dependent Desorption of Proanthocyanidins from Grape-Derived Cell Wall Material under Variable Ethanol Concentrations in Model Wine Systems.

Desorption of proanthocyanidins (PA) from grape cell wall material (CWM) was investigated in solutions of varying ethanol concentrations and increasing temperature. The results reveal the reversibility of PA-CWM interactions and the role that temperature and ethanol concentration play in the extent of PA desorption. Sequentially raising temperature from 15 to 35 °C resulted in desorption of up to 48% of the initial adsorbed PA. A comparison to a phenolic extraction model showed significant differences between the predicted and actual amount of PA that desorbed from the CWM. This suggests that the initial conditions of temperature and ethanol concentration must be considered when estimating PA extraction in red wine production. Under typical winemaking conditions, a significant amount of PA may be irreversibly adsorbed if exposed to CWM at low temperature (i.e., cold soak). A compositional analysis suggests the selective desorption of large molecular weight PA from CWM under all experimental conditions. Additionally, a preferential desorption of skin-derived PA over seed-derived PA was noted in the absence of ethanol.

A Mechanistic Model for the Extraction of Phenolics from Grapes During Red Wine Fermentation.

Phenolic extraction is a critical part of red wine making. Though empirical models of phenolic extraction kinetics exist, the current level of mechanistic understanding does not allow for accurate predictions. In this work, we propose a mechanistic model for the extraction of phenolics from grape skins and seeds as a function of temperature and ethanol. This model examines the release of phenolics, the adsorption of phenolics onto grape material, and the disappearance of anthocyanins from solution. Additionally, we performed epifluorescence microscopy to explore our finding that seed tannins' release rate appears independent of concentration, and found that the grape seed appears to ablate over fermentation. We also determined the activation energy of anthocyanin disappearance, in good agreement with similar systems. The proposed model results in an excellent fit, and increases the understanding of phenolic extraction and the ability to predict and optimize product outcome in red wine making.

Treatment of severe traumatic brain injury in German pediatric intensive care units-a survey of current practice.

PURPOSE: German pediatric guidelines for severe traumatic brain injury (TBI) management expired in 2011. Thus, divergent evidence-based institutional protocols are predominantly being followed. We performed a survey of current Pediatric Intensive Care Unit (PICU) management of isolated severe TBI in Germany to reveal potential varying practices. METHODS: Seventy German PICUs were invited to join an anonymous online survey from February to May 2017. Twenty-nine participants (41.4%) successfully completed the survey (17 university hospitals and 12 district hospitals). The majority of items were polar (yes/no) or scaled (e.g., never - always). Main topics were imaging, neurosurgery, neuromonitoring, adjuvant therapy, and medication. Severity of TBI was defined via Glasgow Coma Scale. RESULTS: The majority of respondents (93.1%) had internal TBI standards, and patients were mainly administered to interdisciplinary trauma units. The use of advanced neuromonitoring techniques, intracranial hypertension management, and drug treatment differed between PICUs. Routine administration of hypertonic saline in TBI-associated cerebral edema was performed by 3.4%, while it was never an option for 31.0% of the participants. Prophylactic anticonvulsive therapy was restrictively performed. If indicated, the main anticonvulsive drugs used were phenobarbital and levetiracetam. Neuroendocrine follow-up was recommended/performed by 58.6% of the PICUs. CONCLUSIONS: This survey provides an overview of the current PICU practices of isolated severe TBI management in Germany and demonstrates a wide instrumental and therapeutical range, revealing an unmet need for the revised national guideline and further (international) clinical trials for the treatment of severe TBI in pediatrics.

Creation and validation of a reactor engineering model for multiphase red wine fermentations.

Red wine fermentations are performed in the presence of grape skins and seeds to ensure the extraction of color and other phenolics. The presence of these solids results in two distinct phases in the fermentor, as the solids float to the top to form a "cap." Modeling of red wine fermentation is, therefore, complex and must consider spatial heterogeneity to predict fermentation kinetics. We have developed a reactor-engineering model for red wine fermentations that includes the fundamentals of fermentation kinetics, heat transfer, diffusion, and compressible fluid flow. To develop the heat transfer component of the model, the heat transfer properties of grapes were experimentally determined as a function of fermentation progression. COMSOL was used to solve all components of the model simultaneously utilizing a finite element analysis approach. Predictions from this model were validated using prior experimental work. Model prediction and experimental data showed excellent agreement. The model was then used to predict spatial profiles of active yeast cell concentration and ethanol productivity, as well as liquid velocity profiles. Finally, the model was used to predict how these gradients would change with differences in initial bioavailable nitrogen concentration, a key parameter in predicting fermentation outcome in nitrogen-limited wine fermentations.

[Unusual cortical compromise in a case of Wernicke's encephalopathy]. / Afectación cortical inusual en un caso de encefalopatía de Wernicke.

INTRODUCTION: Wernicke's encephalopathy (WE) is a metabolic disease due to thiamine deficiency; only 10% of cases are diagnosed pre-mortem. Symptoms of WE include ophthalmoplegia, nistagmus, ataxia and mental confusion; post-mortem examination shows characteristic symmetrical lesions in the mamillary bodies (MB), hypothalamus, thalamus, brain stem and cerebellum with spongiosis, demyelination, vascular proliferation and relative preservation of neurons. CASE REPORT: 50 years-old male with alcoholic hepatopathy and orthotopic hepatic transplant who suffered a second surgical intervention 10 days after due to problems in the biliar anastomosis. After this second surgery he showed an altered mental status, with fluctuating global confusion, disorientation and agitation. He died 52 days after the hepatic transplantation. Autopsy study showed bilateral broncopneumonia, brown discoloration of the MB and bilateral linear lesions in the cortex of both motor gyri, which histologically showed identical to the MB lesions with demyelination, capillary and glial proliferation and preservation of neurons. Alzheimer type II astrocytes were also found in basal nuclei and cortex. CONCLUSIONS: Typical WE lesions affect MB, hypothalamus, thalamus, brain stem and cerebellum; cortical lesions, when found, are due to hepatocerebral degeneration with Alzheimer type II astrocytes or to the citopathic effects of ethanol. In our case, cortical lesions were identical to the lesions found in MB, an extraordinary finding which we have not found reported in the literature.

Hidden peanut allergens detected in various foods: findings and legal measures.

BACKGROUND: Undeclared allergens in foodstuffs represent a major health problem for sensitized persons. Until recently, most food control authorities were not in the position to monitor hidden allergens and to take legal measures against their presence in foodstuffs. METHODS: In this study, we employed human sera-based immunoassay techniques, enabling semiquantitative detection and identification of peanut allergens in a variety of foodstuffs. RESULTS: This study showed the presence of undeclared allergens in products belonging to various food categories, such as cereals, cookies, cakes, and snacks. The detection limit for peanut contamination was in most instances less than 50 mg peanut material per kg, i.e., less than about 5 mg peanut allergens per kg. We legally objected to products with more than one part per thousand or 1000 mg/kg of peanut contamination. CONCLUSIONS: In most cases, food producers, confronted with our results, were able to detect and eliminate the sources of the contamination. They implemented measures to prevent the presence of hidden peanut allergens in their products, increasing food safety for sensitized persons and overall food quality.

[The effect of supermethrin, an insecticide, on health status indicators in sheep during subchronic poisoning]. / Vplyv insekticídu supermetrín na niektoré ukazovatele zdravotného stavu oviec v podmienkach subchronickej intoxikácie.

The effect of supermethrin on the overall health with respect to weight gains, diet intake, triad values (body temperature, pulse rate and breathing rate) and potential intoxication signs was investigated in sheep of the Slovak Mertino breed (age of 8 months, males and females) during 6-week feeding of the insecticide supermethrin (Research Institute of Chemical Technology, Bratislava). This insecticide supermethrin contains a cyanide group in its molecule and can be included in the group of type II pyrethroids. It is an analog of cypermethrin and it has a different proportion of cis- and trans-isomers. Supermethrin mixed with molasses feed M was administered daily at a dose of 50 mg/kg (about 1/70 of LD50) to five sheep of experimental group I, at a dose of 200 mg/kg (about 1/15 of LD50) to five sheep of experimental group II, and the dose increased from 200 mg to 300 mg/kg l.w. (about 1/20 of LD50) since the fourth week of trial. The main signs of its toxic action involved depressive effects on weight gains (Fig. 4) Over the whole period of trial, the live weight rose by 5.44 +/- 1.94 kg in control group, by 2.66 +/- 1.48 kg in experimental group I, which equates a significant decrease by 51.10% and only 0.34 +/- 0.95 kg in experimental group II, which equates a decrease in weight gains by up to 93.75% against the control. We do not believe that the growth depression can be related to diet intake. There were no larger differences in feed intake between the experimental groups and the control. The growth depression was caused by incessant diarrhea. The patho-morphological examination did not reveal hyperemia and/or intestinal inflammation, the histological examination did not show any lesions of epithelium in the intestinal mucosa. An increase in supermethrin dose from 200 to 300 mg/kg l.w. resulted in signs coming from the CNS. Hypersensibility manifested by moderate unrest, head and neck shaking after auditory, and especially after touch stimuli was observed. This tremor was increasing to became spontaneous 3-4 days before trial termination. The above findings clearly suggest that supermethrin administration at lower doses has harmful effects primarily on the digestive tract, but at higher doses these effects are more intensive accompanied by the effects on the CNS. No negative effects on pulse rate (Fig. 1), breathing rate (Fig. 2) and internal body temperature (Fig. 3) were recorded.

Eosinophils in lymph nodes of cows infected by bovine leukaemia virus.

Prescapular lymph nodes from 109 animals positive to bovine leukaemia virus (BLV) were evaluated in this study. Lymph nodes of 81 animals (74.3%) showed an increased number of eosinophils (Eo) in a variety of pathological reactions. Eo counts in T-zonal hyperplasia (47 cases, 43.1%) and mixed hyperplasia (13 cases, 11.9%) were significantly higher (P < 0.05 and P < 0.01, respectively) than in the control group. Similarly, a significantly increased number of blood eosinophils (BEo) was observed in cows with diffuse infiltration by Eo in the lymph nodes as compared to the number of BEo in cows serologically positive to BLV but without morphological changes in the lymph nodes and in cows which were serologically negative (P < 0.05 and P < 0.01, respectively). The possible role of eosinophilic granulocytes in the regulation of immune response to enzootic bovine leukaemia (EBL) is discussed.

Monoclonal cytoplasmic immunoglobulin and pathomorphological reactions in lymph nodes in spontaneous bovine leukemia virus infection.

Prescapular lymph nodes from 109 cows seropositive to bovine leukemia virus (BLV) were examined for the presence of light chains of bovine immunoglobulin (Ig) kappa or lambda. A variety of reactions were present in prescapular lymph nodes, including B-zonal hyperplasia (23 cases, 21.1%), T-zonal hyperplasia (52 cases, 47.7%), mixed hyperplasia (18 cases, 16.5%), pulp proliferation (six cases, 5.5%), and atrophy (ten cases, 9.2%). In the case of pulp proliferation the immunohistological examination identified only Ig of a single light chain type lambda. The possible relationship of a monoclonal expression of Ig and development of tumorous proliferation is discussed in the study.

Pathomorphological and immunohistological changes in lymph nodes of cows spontaneously infected by bovine leukaemia virus.

Prescapular lymph nodes from 109 cows seropositive to bovine leukaemia virus (BLV) were subjected to histologic, cytochemical and in dubious cases also to immunohistologic examination for the presence of light chains of bovine immunoglobulin (Ig) kappa or lambda. By their morphological features, the histologically detected changes were divided into B-zonal hyperplasia (23 cases, 21.1%), T-zonal hyperplasia (52 cases, 47.7%), pulp proliferation (6 cases, 5.5%), hyperplasia of mixed type (18 cases, 16.5%), and atrophy (10 cases, 9.2%). Some changes resembled those reported in infections with human or feline immunodeficiency virus. Eosinophilic infiltration was a frequent feature. Immunohistochemical examination revealed only a lambda Ig chain in the cytoplasm of plasma cells or plasmacytoid cells and immunoblasts in pulp proliferation. Cytochemical examination showed a considerable number of cells with a diffuse positive reaction to acid phosphatase (AP).

[Pathologico-morphologic picture of subchronic trimorfamide poisoning in dogs]. / Patologicko-morfologický obraz subchronickej intoxikácie psov trimorfamidom.

Animals in groups of six dogs and six bitches were given daily in their food, individually, for a period of six months, the fungicide trimorphamide, at dosages of 0, 300 and 500 mg.kg-1 of their weight. After they had been killed, a significant reduction in their weight was observed along with hemosiderosis of the liver, kidneys and spleen of all the experimental animals. No other important structural changes were found by dissection and pathologico-histological examinations of almost all organs and tissues.