Flt3- and Tie2-Cre tracing identifies regeneration in sepsis from multipotent progenitors but not hematopoietic stem cells

In response to infections and stress, hematopoiesis rapidly enhances blood and immune cell production. The stage within the hematopoietic hierarchy that accounts for this regeneration is unclear under natural conditions in vivo. We analyzed by differentiation tracing, using inducible Tie2- or Flt3-driven Cre recombinase, the roles of mouse hematopoietic stem cells (HSCs) and multipotent progenitors (MPPs). During polymicrobial sepsis, HSCs responded transcriptionally and increased their proliferation and cell death, yet HSC differentiation rates remained at steady-state levels. HSC differentiation was also independent from the ablation of various cellular compartments-bleeding, the antibody-mediated ablation of granulocytes or B lymphocytes, and genetic lymphocyte deficiency. By marked contrast, the fate mapping of MPPs in polymicrobial sepsis identified these cells as a major source for accelerated myeloid cell production. The regulation of blood and immune cell homeostasis by progenitors rather than stem cells may ensure a rapid response while preserving the integrity of the HSC population.

Essential phospholipids decrease apoptosis and increase membrane transport in human hepatocyte cell lines

Background

Essential phospholipids (EPL) have hepatoprotective effects across many liver diseases/conditions. The impact of EPL on hepatocyte function in vitro was investigated.

Methods

Effects of noncytotoxic concentrations of EPL (0.1 and 0.25 mg/ml), and its constituents, polyenylphosphatidylcholine (PPC) and phosphatidylinositol (PI) (both at 0.1 and 1 mg/ml), on membrane fluidity, apoptosis and extracellular transport versus controls were investigated in human hepatocyte cell lines (HepG2, HepaRG, steatotic HepaRG). 

Results

Significantly increased membrane fluidity occurred with all 3 phospholipids (PLs) in HepG2 cultures, and with PI (1 mg/ml) in steatotic HepaRG cells. Significantly decreased tamoxifen-induced apoptosis was observed in HepG2 cells with EPL, PPC and PI. Breast cancer resistance protein (BCRP) activity was significantly increased by EPL and PI in HepG2 cells. Multidrug resistance-associated protein 2 (MRP-2) activity was unaffected by any PL in HepG2 cells, and significantly increased by EPL, PI and PPC (1 mg/ml) in HepaRG cells, and by PI (1 mg/ml) in steatotic HepaRG cells. Bile salt export protein (BSEP) activity in HepG2 cells and steatotic HepaRG cells was significantly increased by EPL (0.25 mg/ml), and PPC (both concentrations), but not by PI. The PLs had no effects on HepaRG cell BSEP activity. P-glycoprotein (P-GP) activity was significantly increased by all compounds in HepG2 cells. PI (1 mg/ml) significantly increased P-GP activity in HepaRG and steatotic HepaRG cells.

Conclusions

EPL, PPC, and PI increased hepatocyte membrane fluidity, decreased apoptosis and increased hepatocellular export, all of which may improve liver function. These in-vitro investigations provide valuable insights into the mechanism of action of EPL.

The drug-induced phenotypic landscape of colorectal cancer organoids

Patient-derived organoids resemble the biology of tissues and tumors, enabling ex vivo modeling of human diseases. They have heterogeneous morphologies with unclear biological causes and relationship to treatment response. Here, we use high-throughput, image-based profiling to quantify phenotypes of over 5 million individual colorectal cancer organoids after treatment with >500 small molecules. Integration of data using multi-omics modeling identifies axes of morphological variation across organoids: Organoid size is linked to IGF1 receptor signaling, and cystic vs. solid organoid architecture is associated with LGR5 + stemness. Treatment-induced organoid morphology reflects organoid viability, drug mechanism of action, and is biologically interpretable. Inhibition of MEK leads to cystic reorganization of organoids and increases expression of LGR5, while inhibition of mTOR induces IGF1 receptor signaling. In conclusion, we identify shared axes of variation for colorectal cancer organoid morphology, their underlying biological mechanisms, and pharmacological interventions with the ability to move organoids along them.

The heterogeneity underlying cancer organoid phenotypes is not yet well understood. Here, the authors develop an imaging analysis assay for high throughput phenotypic screening of colorectal organoids that allows to define specific morphological changes that occur following different drug treatments.

POS1569-PARE TESTING A NEW APPROACH TO IDENTIFY AND ASSESS PATIENT-VALUED TREATMENT GOALS IN RHEUMATOID ARTHRITIS (RA): A PATIENT-ENGAGED HEALTHCARE VALUATION STRATEGY

Background

Common approaches to valuing health technologies often fail to capture outcomes that matter to patients and families. The treatment goals of people living with rheumatoid arthritis (RA) include common trial endpoints but also include other facets of disease impact. Identifying a feasible and rigorous approach to inclusion of the patient perspective is needed as trialists increasingly seek to incorporate patient-important outcomes in trial design and as varied patient-centered value assessment frameworks emerge. No standard approach is available to systemically identify and quantify patient-important outcomes, nor to include those outcomes in deliberative decision-making. We developed the Patient-Engaged Healthcare Valuation strategy, using principles of goal attainment scaling to frame survey-based goal collection directly from adults.

Objectives

To develop and test a goal-based method for collecting RA patient input for use in clinical trials and value assessment and evaluating the feasibility of this approach in people with RA.

Methods

Patient goals and domains were identified from (1) a literature review (2010-2020) of patient outcomes, goals, and preferences in RA, and (2) discussions with patients and clinicians during two meetings with a steering committee (SC) consisting of clinicians, outcomes researchers, patients/advocates, and health economists. These goals informed the development of a draft survey. Adults with RA were recruited from online patient networks to rate goal importance and suggest additional goals. SC members reviewed the survey findings and assessed feasibility of scaling up goal collection for HTA.

Results

Of 135 articles identified, 17 were retained. An inductive and iterative approach was used to identify and thematically group the final set of 36 goals into 4 domains. The draft survey was cognitively debriefed with 4 adults with RA. The first survey was administered to 20 participants; results informed item revisions and additions for the second round of data collection (n=27).

The 47 respondents were mostly White (87%), college-educated (72%) women (93%) living with RA for an average of 15 years; 75% rated their RA as moderate to severe. Free-text goals added in round 1 include: 1) finding specialists who listen to patient input on symptoms; 2) addressing loneliness or isolation; and 3) finding support from or helping others with RA. All Symptom and Life Impact goals were rated as Important or Very Important by ≥85% of participants; endorsement for Management and Treatment goals was somewhat more variable, with ≥85% endorsing these as Somewhat to Very Important. Results suggested that domains match key goals. Steering committee ratings supported the feasibility of this method.

Conclusion

Goals relevant for RA treatment evaluation can be efficiently identified and rated for importance by patients. Patient-important goals can be incorporated into deliberative healthcare valuation using this method to permit “crowd-sourced” input from people living with RA and to capture heterogeneous patient perspectives in healthcare valuation.

Table 1.

Top Goals based on rating as “Very Important” by >70% of subjects, from set of 36. “My goals for living with RA are to…”

GoalsNot ImportantSomewhat ImportantImportantVery ImportantSymptom Managementimprove the quality of my life with RA0% (0)0% (0)23% (11)77% (36)manage my RA pain0% (0)2% (1)11% (5)87% (41)reduce how my RA pain interferes with my life0% (0)9% (4)17% (8)74% (35)Life Impactreduce the ways in which RA interferes with my life0% (0)2% (1)21% (10)77% (36)be independent in my daily functioning0% (0)4% (1)15% (4)81% (22)Managing my RAfeel like I can manage my RA0% (0)2% (1)26% (12)72% (34)Treatment Featuresunderstand my RA treatment options0% (0)4% (2)21% (10)74% (35)have the information I need to make treatment decisions0% (0)0% (0)19% (9)81% (38)know what to expect with my RA treatment0% (0)2% (1)23% (11)74% (35)find treatments that are effective0% (0)0% (0)6% (3)94% (44)

Acknowledgements

I have no acknowledgements to declare.

Disclosure of Interests

None declared

Review: Southern African medicinal plants used as blood purifiers

ETHNOPHARMALOGICAL RELEVANCE

Blood purification practices, also referred to as blood cleansing or detoxification, is an ancient concept which is widespread amongst African traditional medicine, but for which no modern scientific basis exists. There prevails considerable ambiguity in defining what a blood purifier is.

AIM OF THE STUDY

The purpose of this review is to firstly define what a blood purifier is in the context of African traditional medicine and compare to other cultural and westernized interpretations. Thereafter, this study identifies traditionally used medicinal plants used as blood purifiers in southern Africa and correlates these species to scientific studies, which may support evidence for these "blood purifying plant species".

MATERIALS AND METHODS

Ethnobotanical books and review articles were used to identify medicinal plants used for blood purification. Databases such as Scopus, ScienceDirect, PubMed and Google Scholar were used to source scientific articles. An evaluation was made to try correlate traditional use to scientific value of the plant species.

RESULTS

One hundred and fifty nine plant species have been documented as traditional remedies for blood purification. Most of the plant species have some pharmacological activity, however, very little link to the traditional use for blood purification. There has been some justification of the link between blood purification and the use as an antimicrobial and this has been explored in many of the plant species identified as blood purifiers. Other pharmacological studies specifically pertaining to the blood require further attention.

CONCLUSION

Irrespective of the ambiguity of interpretation, medicinal plants used to "cleanse the blood", play an important holistic role in traditional medicine and this review with recommendations for further study provides some value of exploring this theme in the future.

The health situation of children and adolescents with migration background in Germany

Introduction

Although more than one third of minors living in Germany have a migration background (MB), valid data on the health of this population are still lacking. The German Health Interview and Examination Survey for Children and Adolescents in Germany (KiGGS wave 2, 2014-2017) provides population-based data to make reliable statements on the health of adolescents with and without MB.

Methods

Survey data from KiGGS wave 2 are used to describe the general health status, mental health and the prevalence of allergic diseases in 3-to 17-year-old children and adolescents (n = 13,568). To determine overweight, body height and weight are measured (n = 3,463). In addition to MB (without/one-sided/two-sided), the socio-economic status (SES) and the length of stay of the parents in Germany are taken into account.

Results

Children and adolescents with two-sided MB show a physician-diagnosed atopic dermatitis (3.5%vs.6.9%) and attention deficit hyperactivity disorder (ADHD) (1.5%vs.5.1%) less frequently than their peers without MB, but more often a moderate or poor general health status (6.1%vs.3.9%). Adolescents with two-sided MB are also more often affected by overweight than those without MB (22.1%vs.12.2%). If only participants with MB are considered, their health situation is often associated with the SES and partly also with the length of stay of the parents.

Discussion

Health differences between children and adolescents with and without MB vary by the observed indicator. The heterogeneity of children and adolescents with MB, which can be partly determined by the SES or the length of stay of the parents, should be considered in target-group-specific interventions.

Main messages

The vast majority of children and adolescents in Germany grow up healthy and a MB is not per se associated with a poorer health status. Our results suggest that considering MB as the sole determinant of health to reflect the impact of migration on health is insufficient.

Key messages

Migration background is not per se associated with a poorer health status. Socioeconomic status and parents’ length of stay are derminants associated with poorer health outcomes among children and adolescents with migration background.

Patchy Amphiphilic Dendrimers Bind Adenovirus and Control Its Host Interactions and in Vivo Distribution

The surface of proteins is heterogeneous with sophisticated but precise hydrophobic and hydrophilic patches, which is essential for their diverse biological functions. To emulate such distinct surface patterns on macromolecules, we used rigid spherical synthetic dendrimers (polyphenylene dendrimers) to provide controlled amphiphilic surface patches with molecular precision. We identified an optimal spatial arrangement of these patches on certain dendrimers that enabled their interaction with human adenovirus 5 (Ad5). Patchy dendrimers bound to the surface of Ad5 formed a synthetic polymer corona that greatly altered various host interactions of Ad5 as well as in vivo distribution. The dendrimer corona (1) improved the ability of Ad5-derived gene transfer vectors to transduce cells deficient for the primary Ad5 cell membrane receptor and (2) modulated the binding of Ad5 to blood coagulation factor X, one of the most critical virus-host interactions in the bloodstream. It significantly enhanced the transduction efficiency of Ad5 while also protecting it from neutralization by natural antibodies and the complement system in human whole blood. Ad5 with a synthetic dendrimer corona revealed profoundly altered in vivo distribution, improved transduction of heart, and dampened vector sequestration by liver and spleen. We propose the design of bioactive polymers that bind protein surfaces solely based on their amphiphilic surface patches and protect against a naturally occurring protein corona, which is highly attractive to improve Ad5-based in vivo gene therapy applications.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Plasma chemistry before and after two consecutive days of racing in sled dogs: associations between muscle damage and electrolyte status

Exercising long distance endurance sled dogs display plasma biochemistry changes characterised by elevations in creatine kinase (CK) and aspartate aminotransferase (AST), hypoproteinemia, hypoglobulinemia and decreases in sodium and potassium. The aim of this study was to compare resting to day 2 racing plasma biochemistry and associations between electrolytes and markers of muscle damage in well-conditioned sled dogs during a stage-stop race. Blood samples were obtained from 23 dogs prior to the start and on day 2, immediately after racing. Results showed significant decreases in potassium (day 0 – 4.7±0.3 and day 2 – 4.2±0.3 mEq/l), total protein (day 0 – 6.0±0.3 and day 2 – 5.5±0.4 g/dl) and albumin concentrations (day 0 – 3.9±0.2 and day 2 – 3.6±0.3 g/dl). Increases in AST (day 0 – 24±7 and day 2 – 137±97 U/l) and CK activities (day 0 – 129±39 and day 2 – 2,047±2,021 U/l) were also observed. Plasma sodium concentrations were not significantly different after day 2 of racing (day 0 – 153±5.2 and day 2 – 151±4.1). Alterations in plasma electrolytes, and increases in AST, CK, alanine aminotransferase and urea nitrogen were similar to those observed in long distance endurance sled dogs. A strong negative association was observed between plasma potassium and increases in plasma CK activity on day 2 (R2=0.69). The maintenance of sodium concentrations with a concurrent potassium decline, suggests sodium conservation via the renin-angiotensin-aldosterone pathway as previously shown in endurance sled dogs. The negative correlation between muscle damage and plasma potassium warrants further investigation regarding its relationship to rhabdomyolysis.

Imaging of tissue sections with very slow electrons

The examination of thin sections of tissues with electron microscopes is an indispensable tool. Being composed of light elements, samples of living matter illuminated with electrons at the usual high energies of tens or even hundreds of kiloelectronvolts provide very low image contrasts in transmission or scanning transmission electron microscopes. Therefore, heavy metal salts are added to the specimen during preparation procedures (post-fixation with osmium tetroxide or staining). However, these procedures can modify or obscure the ultrastructural details of cells. Here we show that the energy of electrons used for the scanned transmission imaging of tissue sections can be reduced to mere hundreds or even tens of electronvolts and can produce extremely high contrast even for samples free of any metal salts. We found that when biasing a sufficiently thin tissue section sample to a high negative potential in a scanning transmission electron microscope, thereby reducing the energy of the electrons landing on the sample, and collecting the transmitted electrons with a grounded detector, we obtain a high contrast revealing structure details not enhanced by heavy atoms. Moreover, bombardment with slow electrons sensitively depolymerises the resin in which the tissue is embedded, thereby enhancing the transmitted signal with no observable loss of structure details. The use of low-energy electrons requires ultrathin sections of a thickness of less than 10nm, but their preparation is now possible. Ultralow energy STEM provides a tool enabling the observation of very thin biological samples without any staining. This method should also be advantageous for examination of 2D crystals, thin films of polymers, polymer blends, etc.

How does non-nutritive sucking support infant feeding?

Fifty nine premature infants participated in a randomized controlled study to determine the effectiveness of non-nutritive sucking (NNS). It was predicted that NNS would not accelerate the development of full oral feeding or early language skills as sometimes perceived in practice. However, it was predicted that using NNS as a strategy to support parents to identify and respond to early communication and oral readiness signs would increase confidence in infant management and enable quicker discharge home. Infants were aged 26-35 weeks gestation. Infants with no significant difficulties were randomly assigned to one of three groups; Group 1, NNS pre-tube feeding (n=19); Group 2, NNS on onset of tube feeding (n=20) and Group 3, Control (n=20). Follow-up occurred at 6 months. There were no significant differences with number of days to full oral feeding between the groups receiving NNS and the Control group, χ2(2, n=59)=4.33, p=.115. A significant difference in number of days in hospital between the Control group and the other two groups was found χ2 (2, n=59)=7.678, p=.022. Significant changes were noted with the development of more normal sucking patterns in Groups 1-3. At 6 months there were no significant differences in receptive or expressive language skills between all groups. NNS had no significant impact on the transition to full oral feeding or later language development. There was a significant difference in the number of days in hospital between the Control group and the other two groups which involved parents in identification of early communication signs. Possible reasons for this change and future directions are discussed.

Very low energy electron microscopy of graphene flakes

Commercially available graphene samples are examined by Raman spectroscopy and very low energy scanning transmission electron microscopy. Limited lateral resolution of Raman spectroscopy may produce a Raman spectrum corresponding to a single graphene layer even for flakes that can be identified by very low energy electron microscopy as an aggregate of smaller flakes of various thicknesses. In addition to diagnostics of graphene samples at larger dimensions, their electron transmittance can also be measured at very low energies.

The validity and reliability of iridology in the diagnosis of previous acute appendicitis as evi-denced by appendectomy

Iridology is defined as a photographic science that identifies pathological and functional changes within organs via biomicroscopic iris assessment for aberrant lines, spots, and discolourations. According to iridology, the iris does not reflect changes  during  anaesthesia,  due  to  the  drugs inhibitory  effects  on  nerves  impulses,  and  in cases of organ removal, it reflects the pre-surgical condition.The profession of Homoeopathy is frequently associated with iridology and in a recent survey (2009)  investigating  the  perceptions  of  Masters of  Technology  graduates  in  Homoeopathy  of University of Johannesburg, iridology was highly regarded as a potential additional skill requirement for assessing the health status of the patient.This  study  investigated  the  reliability  of iridology  in  the  diagnosis  of  previous  acute appendicitis, as evidenced by appendectomy. A total of 60 participants took part in the study. Thirty of the 60 participants had an appendectomy due to acute appendicitis, and 30 had had no prior history  of  appendicitis.  Each  participant’s  right iris  was  documented  by  photography  with  the use  of  a  non-mydriatic  retinal  camera  that  was reset for photographing the iris. The photographs were then randomized by an external person and no identifying data made available to the three raters.  The  raters  included  the  researcher,  who had little experience in iridology and two highly experienced  practising  iridologists.  Data  was obtained  from  the  analyses  of  the  photographs wherein  the  presence  or  absence  of  lesions (implying acute appendicitis) was indicated by the raters. None of the three raters was able to show a significant  success  rate  in  identifying  correctly the  people  with  a  previous  history  of  acute appendicitis and resultant appendectomies from those  who  had  no  previous  history  of  acute appendicitis.  Therefore the outcome of this study indicated an outcome that was subject to chance.The  null  hypothesis  that  states  that appendectomy due to acute appendicitis does not manifest in corresponding lesions in the iris, is supported. It is in the opinion of the researchers that the  association  of  iridology  with  homoeopathic practice may harm the credibility of the profession and that further research on iridology is needed to disprove this conviction. (S Afr Optom 2013 72(3) 127-132)

A topological paradigm for hippocampal spatial map formation using persistent homology

An animal's ability to navigate through space rests on its ability to create a mental map of its environment. The hippocampus is the brain region centrally responsible for such maps, and it has been assumed to encode geometric information (distances, angles). Given, however, that hippocampal output consists of patterns of spiking across many neurons, and downstream regions must be able to translate those patterns into accurate information about an animal's spatial environment, we hypothesized that 1) the temporal pattern of neuronal firing, particularly co-firing, is key to decoding spatial information, and 2) since co-firing implies spatial overlap of place fields, a map encoded by co-firing will be based on connectivity and adjacency, i.e., it will be a topological map. Here we test this topological hypothesis with a simple model of hippocampal activity, varying three parameters (firing rate, place field size, and number of neurons) in computer simulations of rat trajectories in three topologically and geometrically distinct test environments. Using a computational algorithm based on recently developed tools from Persistent Homology theory in the field of algebraic topology, we find that the patterns of neuronal co-firing can, in fact, convey topological information about the environment in a biologically realistic length of time. Furthermore, our simulations reveal a "learning region" that highlights the interplay between the parameters in combining to produce hippocampal states that are more or less adept at map formation. For example, within the learning region a lower number of neurons firing can be compensated by adjustments in firing rate or place field size, but beyond a certain point map formation begins to fail. We propose that this learning region provides a coherent theoretical lens through which to view conditions that impair spatial learning by altering place cell firing rates or spatial specificity.

Bioluminescent signal system: bioluminescence immunoassay of pathogenic organisms

The Ca(2+)-regulated photoprotein obelin has been examined as a label for bioluminescence immunoassay of infective agents. The hepatitis B virus (HbsAg) and the bacteria Escherichia coli and Shigella sonnei lipopolysaccharide (LPS) were chosen as model antigens. Chemically synthesized obelin-corresponding antibody conjugates were used in a solid-phase microplate immunoassay. The sensitivities achieved by the assay were 0.25 ng/mL for S. sonnei LPS and 0.375 ng/mL for HbsAg. A novel, filter-based immunoassay to determine bacterial admixtures in the environment was proposed. The NanoCeram filters were effectively applied to 'trap' and pre-concentrate pathogens from samples under study for the purposes of further detection and measurement of the absorbed material by bioluminescence immunoassay.

Corrections of magnification and focusing in a cathode lens-equipped scanning electron microscope

One of the well-proven and efficient methods of obtaining a very low-energy impact of primary electrons in the scanning electron microscope is to introduce a retarding field element below the pole piece of the objective lens (OL). It is advantageous to use the specimen alone as the negatively biased electrode (i.e., cathode of the cathode lens). The optical power of the cathode lens modifies some of the standard parameters of the image formation such as relation of working distance to OL excitation or magnification to the scanning coils current, the impact angle of primary electrons, and so forth. In computer-controlled electron microscopes these parameters, particularly with regard to focusing and magnification, can be corrected automatically. Derivation of algorithms for such corrections and their experimental verifications are presented in this paper. Furthermore, a more accurate analytical expression for the focal length of an aperture lens is derived.