Towards collaborative action: A project on interprofessional stroke care in the Covid-19 pandemic

Background

Stroke is one of the leading causes of disability in adulthood. Cooperatively organised stroke care requires a high degree of interprofessional competence of junior professionals.

Objectives

The project aim was to develop interprofessional competences for stroke care, to identify gaps in care as well as approaches to innovation during the pandemic through joint research. The focus was on person-centred care, communication and collaboration, roles and responsibilities, including stroke-navigators. German Bachelor students of occupational therapy, physiotherapy and speech therapy of the 7th semester (n = 22) were accompanied online in 60 teaching units in 2020/2021. The seminars consisted of (a) theoretical introduction to interprofessional stroke care (b) case-based collaboration with problem-based learning (c) applied health services research. The evaluation was based on a central questionnaire and written reflections from all students.

Results

The following themes were identified and investigated in 5 interprofessional groups: (1) Impact of the Covid-19 pandemic on the acute care and rehabilitation of stroke patients, (2) International comparison of interprofessional stroke care based on guidelines to improve current practice, (3) Interprofessional diagnostics in stroke care, (4) Interprofessional patient-centered goal setting in outpatient stroke care, (5) Agreements of actors involved in stroke treatment to best serve the needs of the patient. The response rate to the centralised evaluation was low (14%). The project was rated good to very good in terms of planning and presentation, relevance, and interaction with students.

Conclusions

The students reported central aspects for interprofessional learning: The reflections predominantly described growth in professional competences, in skills for cooperation and problem solving, which can be transferred to professional life. The main point of criticism was the necessity of digital teaching in the pandemic.

Key messages

• Empowering interprofessional cooperation through a joint project of different Bachelor programmes helps to strengthen the students’ professional identity and shared responsibility for stroke care.

• Online teaching can be a valuable facilitator of learning, but should not completely replace face-to-face teaching for stroke care.

Forecasting brain activity based on models of spatiotemporal brain dynamics: A comparison of graph neural network architectures

Comprehending the interplay between spatial and temporal characteristics of neural dynamics can contribute to our understanding of information processing in the human brain. Graph neural networks (GNNs) provide a new possibility to interpret graph-structured signals like those observed in complex brain networks. In our study we compare different spatiotemporal GNN architectures and study their ability to model neural activity distributions obtained in functional MRI (fMRI) studies. We evaluate the performance of the GNN models on a variety of scenarios in MRI studies and also compare it to a VAR model, which is currently often used for directed functional connectivity analysis. We show that by learning localized functional interactions on the anatomical substrate, GNN-based approaches are able to robustly scale to large network studies, even when available data are scarce. By including anatomical connectivity as the physical substrate for information propagation, such GNNs also provide a multimodal perspective on directed connectivity analysis, offering a novel possibility to investigate the spatiotemporal dynamics in brain networks.

Response of diamond detectors in ultra-high dose-per-pulse electron beams for dosimetry at FLASH radiotherapy

Objective. With increasing investigation of the so-called FLASH effect, the need for accurate real time dosimetry for ultra-high dose rates is also growing. Considering the ultra-high dose-per-pulse (DPP) necessary to produce the ultra-high dose rates for investigations of the FLASH effect, real time dosimetry is a major challenge. In particular, vented ionization chambers, as used for dosimetry in conventional radiotherapy, show significant deviations from linearity with increasing DPP. This is due to recombination losses in the sensitive air volume. Solid state detectors could be an alternative. Due to their good stability of the response with regard to the accumulated dose, diamond detectors such as the microDiamond could be suitable here. The aims of this work are to investigate the response of microDiamond and adapted microDiamond prototypes in ultra-high DPP electron beams, to understand the underlying effects and to draw conclusions for further detector developments. Approach. For the study, an electron beam with a DPP up to 6.5 Gy and a pulse duration of 2.5 μs was used to fulfill the conditions under which the FLASH effect was observed. As a dose rate-independent reference, alanine dosimeters were used. Main Results. It has been shown that the commercially available microDiamond detectors have limitations in terms of linearity at ultra-high DPP. But this is not an intrinsic limitation of the detector principle. The deviations from linearity were correlated with the series resistance and the sensitivity. It could be shown that the linear range can be extended towards ultra-high DPP range by reducing the sensitivity in combination with a low series resistance of the detectors. Significance. The work shows that synthetic single crystal diamond detectors working as Schottky photodiodes are in principle suitable for FLASH-RT dosimetry at electron linear accelerators.

Antimicrobial effects of mustard oil-containing plants against oral pathogens: an in vitro study

Background

The present study examines the antimicrobial activity of nasturtium herb (Tropaeoli maji herba) and horseradish root (Armoraciae rusticanae radix) against clinically important oral bacterial pathogens involved in periodontitis, gingivitis, pulpitis, implantitis and other infectious diseases.

Methods

A total of 15 oral pathogens, including members of the genera Campylobacter, Fusobacterium, Prevotella, Parvimonas, Porphyromonas, Tanerella, Veillonella, and HACEK organisms, were exposed to [1] a combination of herbal nasturtium and horseradish using a standardized gas test and [2] a mixture of synthetic Isothiocyantes (ITCs) using an agardilution test. Headspace gas chromatography mass spectrometry was employed to quantify the amount of allyl-, benzyl-, and 2- phenyl- ethyl-ITC.

Results

With exception of Veillonella parvula, all tested species were highly susceptible to herbal nasturtium and horseradish in the gas test with minimal inhibitory concentrations (MICs) between 50/20 mg and 200/80 mg and to synthetic ITCs in the agardilution with MICs between 0.0025 and 0.08 mg ITC/mL, respectively. Minimal bactericidal concentrations extended from 0.005 mg ITC/mL to 0.34 mg ITC/mL.

Conclusions

ITCs may be considered an interesting alternative to antibiotics for prevention and treatment of oropharyngeal infections, periodontitis and related diseases. Furthermore, the suitability of ITCs for endocarditis prophylaxis in dental procedures might be worth further investigation.

[Educational and Professional Qualifications of Adults With Myotonic Dystrophies - A Misleading Perception by the Myopathic Face?]

BACKGROUND

Myotonic dystrophies types 1 and 2 (DM1 / DM2) are the most frequent inherited progressive, segmental progeroid, multisystemic neuromuscular diseases in adulthood. The executive impairment is one of the key disease features. The myopathic face triggers the general perception of DM1 patients being associated with a low educational level.

METHODS

We used a standardized questionnaire to evaluate educational levels in adults with genetically confirmed DM1 and DM2 in comparison to data of the general population. Investigated topics included the level of education, e. g. the highest university degree aquired.

RESULTS

Out of a total cohort of 546 DM patients, 125 DM1 and 156 DM2 patients (51 %) participated in this study. There was no statistically significant difference between the two collectives as far as high school levels are concerned. 50.4 % of DM1 and 48.3 % of DM2 patients obtained the higher education entrance qualification compared to 29.6 % of the normal German population. However, there were significant differences between the two collectives in "spelling problems" (DM1 cohort: p = 0.039), "difficulty in mental arithmetic" (p = 0.043), and classification of patients "with learning difficulties" (p = 0.012).

DISCUSSION

Misled by a myopathic face, many physicians associate myotonic dystrophy with cognitive deficiency. Based on our study, the minimal deviation between DM1 and DM2 and the normal German population indicates that the multisystemic disease does not significantly influence the maximum attainable level of education in adults with DM1.

CONCLUSION

In summary, physicians should be aware that the general educational levels are rather normal in patients with myotonic dystrophy type 1 and rethink their perception of DM1 patients.

Coherence during scattering of fast H atoms from a LiF(001) surface

The coherence for diffraction effects during grazing scattering of fast hydrogen and helium atoms from a LiF(001) surface with energies up to some keV is investigated via the coincident detection of two-dimensional angular distributions for scattered projectiles with their energy loss. For keV H atoms, we identify electronic excitations of the target surface as the dominant mechanism for decoherence, whereas for He atoms this contribution is small. The suppression of electronic excitations owing to the band gap of insulators plays an essential role for preserving quantum coherence and thus for the application of fast atom diffraction as a surface analytical tool.

Fast atom diffraction from superstructures on a Fe110 surface

Fast atoms with energies from 500 eV up to several keV are grazingly scattered from a Fe(110) surface covered with defined superstructures of sulfur or oxygen atoms. For scattering along low index azimuthal directions, we observe defined diffraction patterns in the angular distributions for scattered projectiles. From the analysis of those patterns, we derive the widths of low indexed axial channels and the corrugation of the interaction potential across these channels. This allows us to estimate the positions of adsorbed atoms on the Fe(110) surface. By demonstration, for adsorbate induced superstructures on a metal surface, we show that fast atom diffraction, first observed for insulators, can be applied to studies on surface structures for a wide range of materials.

Supernumerary rainbows in the angular distribution of scattered projectiles for grazing collisions of fast atoms with a LiF(001) surface

Fast atoms with keV energies are scattered under a grazing angle of incidence from a clean and flat LiF(001) surface. For scattering along low index azimuthal directions within the surface plane ("axial surface channeling") we observe pronounced peak structures in the angular distributions for scattered projectiles that are attributed to "supernumerary rainbows." This phenomenon can be understood in the framework of quantum scattering only and is observed here up to projectile energies of 20 keV. We demonstrate that the interaction potential and, in particular, its corrugation for fast atomic projectiles at surfaces can be derived with a high accuracy.

Diffraction of fast atomic projectiles during grazing scattering from a LiF(001) surface

Light atoms and molecules with energies from 300 eV to 25 keV are scattered under a grazing angle of incidence from a LiF(001) surface. For impact of neutral projectiles along low index directions for strings of atoms in the surface plane we observe a defined pattern of intensity spots in the angular distribution of reflected particles which is consistently described using concepts of diffraction theory and specific features of grazing scattering of atoms from insulator surfaces. Experimental results for scattering of H, D, 3He, and 4He atoms as well as H2 and D2 molecules can be unequivocally referred to atom diffraction with de Broglie wavelengths as low as about 0.001 Angstroms.

Regulation of glucose tolerance in patients after liver transplantation: impact of cyclosporin versus tacrolimus therapy

BACKGROUND

We investigated the factors regulating glucose homeostasis in 10 healthy (control) subjects, as well as in stable, long-term, liver-grafted patients receiving monotherapy in the form of either cyclosporin A (n=10) or tacrolimus (n=10).

METHODS

We measured insulin sensitivity, first- and second-phase insulin secretion, with a minimal modeling technique based on the analysis of glucose, insulin, and C-peptide profiles during frequently sampled intravenous glucose tolerance tests (FSIGTT). Proinsulin levels, as a marker of beta-cell dysfunction, were measured in the fasting state and during FSIGTT.

RESULTS

Glucose and insulin concentrations before and after glucose loading did not differ in liver transplant patients and in control subjects. Fasting C-peptide levels in both liver-grafted groups were higher than in healthy subjects and remained elevated during FSIGTT (P<0.05). Intravenous glucose tolerance [(K(G)), i.e. the slope of the regression of logarithm of the blood glucose concentrations vs. time], insulin sensitivity, and first-phase insulin secretion did not differ in liver-grafted groups and healthy subjects. Second-phase insulin secretion was about 56% higher in liver-grafted patients than in controls (P<0.05). Body mass index was the overall determinant of insulin sensitivity in all groups.

CONCLUSIONS

Long-term monotherapy with cyclosporin A or tacrolimus has no deleterious effects on insulin sensitivity, first-phase insulin secretion, and insulin synthesis in liver transplant patients. Normal insulin sensitivity (posthepatic insulin effect) and enhanced second-phase insulin secretion (prehepatic insulin) point to an accelerated hepatic insulin clearance rate in liver transplant patients. Increased hepatic insulin clearance is compensated by enhanced insulin secretion, indicating that insulin clearance is the major determinant of pancreatic function in liver-grafted patients.

Evidence for impaired glucose effectiveness in cirrhotic patients after liver transplantation

To evaluate the impact of acute and chronic liver disease and single immunosuppression (cyclosporine A [CSA] or FK506) on insulin sensitivity and glucose effectiveness in liver-grafted patients, we performed a frequently sampled intravenous glucose tolerance test (FSIGTT) in nondiabetic patients after orthotopic liver transplantation (OLT) with acute liver failure ([ALF] group, n = 9, with CSA therapy), in patients after OLT with chronic liver disease (CSA group, n = 8; FK506 group, n = 8), and in 9 healthy control subjects. Insulin sensitivity and glucose effectiveness were determined by analyzing glucose and insulin data from the FSIGTT with Bergman's minimal model technique for glucose. The intravenous glucose tolerance index ([KG] ie, the slope of the regression of the logarithm of blood glucose concentration) was not different between the ALF group (2.17 +/- 0.16 min(-1)) and controls (2.29 +/- 0.13 min(-1)), but was lower (P < .05) in both groups with chronic liver disease (CSA group, 1.46 +/- 0.1; FK506 group, 1.61 +/- 0.11 min(-1)) compared with the ALF group (P < .05). A positive relation for the KG and glucose effectiveness was found in all liver-grafted patients and controls. Insulin sensitivity was not different between all liver-grafted patients and controls. The body mass index (BMI) was the overall determinant of insulin sensitivity in all groups. Single immunosuppressive therapy does not impair insulin sensitivity in liver-grafted patients. The lower glucose effectiveness in liver-grafted patients with chronic liver disease but not in patients after ALF points to a defect in the regulation of glucose-mediated glucose uptake in peripheral tissue.

Cloning and DNA sequence analysis of pepQ, a prolidase gene from Lactobacillus delbrueckii subsp. lactis DSM7290 and partial characterization of its product

From a genomic library of Lactobacillus delbrueckii subsp. lactis (DSM7290) DNA, in the low-copy-number vector pLG339, a recombinant clone was selected, which complemented a mutation in the prolidase gene (pepQ) of Escherichia coli UK173. Nucleotide sequence analysis revealed an open reading frame of 1104 nucleotides corresponding to a protein of 368 amino acids with a calculated pI of 4.64 and a molecular mass of 41,087 Da. The start site of pepQ transcription was determined by primer extension analysis with mRNA prepared from L. delbrueckii. Based on homology of the gene product to various peptidases and on the substrate specificity determined, the peptidase was designated PepQ. The influence of various protease inhibitors and cations on peptidase activity indicated that PepQ is a metalloprotease. The absence of a membrane-spanning domain and a signal peptide sequence argues for a cytoplasmic localization of the enzyme.

Effect of ethanol on arachidonic acid metabolism in macrophages

The authors report preliminary data on the production of arachidonic acid metabolites by ethanol stimulated macrophages. They focus on the substantial implications for understanding the pathobiology of alcoholism.

Acetylated low-density lipoproteins promote the release and metabolism of arachidonic acid by murine macrophages

We studied the effect of acetyl-LDL on the synthesis of eicosanoids by primary cultures of mouse-resident peritoneal macrophages. A dosis of 150 micrograms of acetyl-LDL proteins promotes a maximal release of arachidonic acid metabolites into extracellular medium. This process is very rapid and reaches the maximal value about ten minutes after stimulation. The pattern of arachidonic acid metabolites released is different from that obtained when the cells are stimulated with a phagocytosable particle like zymosan or calcium ionophore A23187. The data show that the metabolism of arachidonic acid by cycloxigenase is diminished. In an unusual way the amounts of prostaglandin PGE2, 6-keto-prostaglandin PGF1 alpha and thromboxane TXB2 synthesized are similar.

The interaction of ethanol and exogenous arachidonic acid in the generation of extracellular messengers by mouse peritoneal macrophages

It is increasingly recognized that macrophages play a crucial role in the development of chronic inflammatory states such as alcoholic liver disease. These cells can metabolize free arachidonic acid in the absence of a discernible trigger. The present study was undertaken to examine the short-term effects of ethanol on the generation of these exogenous arachidonate-derived extracellular mediators. Ethanol caused a dose-dependent decrease in the production of both cyclooxygenase and lipoxygenase metabolites. Similar effects were observed on the esterification of exogenous arachidonate into cellular lipids. To characterize further the effects of ethanol on exogenous arachidonic acid metabolism, we studied the short-term responses displayed by macrophages challenged with another soluble stimulus; the tumor-promoting agent phorbol myristate acetate. We observed an inhibition by ethanol of the superoxide anion response triggered by phorbol myristate acetate similar to that observed for exogenous arachidonate oxygenation. Our results show that ethanol can inhibit these soluble stimuli-elicited responses, possibly through its disorganizing effect on plasma membrane.

Phospholipase A2 activity in resting and activated human neutrophils. Substrate specificity, pH dependence, and subcellular localization

We have studied the phospholipase A2 activity in fractionated human neutrophils, employing labeled phosphatidylinositol, phosphatidylcholine, and phosphatidylethanolamine as exogenous substrates. We used these phospholipid substrates labeled in the sn-1 position and measured the resulting labeled lysophospholipid forms in order to ascertain the phospholipase A2 specificity. In postnuclear supernatants from resting and A23187-activated cells, the phospholipase A2 activity showed a similar pH dependence curve with two pH optima at 5.5 and 7.5. Extracts from activated cells showed a 3-6-fold increase in enzyme activity. The subcellular distribution of phospholipase A2 activity in resting and A23187-treated human neutrophils was investigated by fractionation of postnuclear supernatants on continuous sucrose gradients. The neutral phospholipase A2 behaved as a membrane-bound enzyme and was mainly localized in the plasma membrane, the azurophilic granule, and in an ill-defined region of the gradient between the specific granules and mitochondria. The phospholipase A2 located in this undefined region showed a higher degree of activation than that located in other subcellular particulates in A23187-treated cells. This specific activation of an intracellular phospholipase A2 activity during cell stimulation indicates that cell compartmentalization may play a role in the formation of cell-activating and/or signal-transducing agents through the generation of arachidonate metabolites. Phosphatidylinositol was a better substrate for the plasma membrane enzyme, whereas phosphatidylcholine and phosphatidylethanolamine behaved as better substrates for intracellular organelle phospholipase A2 activities. The phospholipase A2 with maximal activity at pH 5.5 behaved as a soluble enzyme, and was almost completely localized in the azurophilic granules. Upon cell activation this acid enzyme activity was released in a similar way to beta-glucuronidase, a marker of azurophilic granules. These results demonstrate the different molecular properties of the phospholipase A2 activity, on the basis of its cellular location.

Ethanol induces release of arachidonic acid but not synthesis of eicosanoids in mouse peritoneal macrophages

Exposure of mouse peritoneal macrophages to ethanol induces a rapid release of arachidonic acid to the extracellular medium. All major classes of phospholipids, phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol contribute to this release. Ethanol-induced mobilization of arachidonic acid occurs by deacylation, but it is not accompanied by eicosanoid synthesis. These data suggest that at least two signals are necessary for the release and metabolism of arachidonic acid. Ethanol also activates a phospholipase C which hydrolyzes only phosphatidylinositol, and not its phosphorylated derivatives.

Urinary excretion of enzymes in cirrhotics with renal failure

We studied the significance of urinary enzyme measurements in diagnosing proximal tubular damage in cirrhosis of the liver. Urinary excretion (u-enzyme) and fractional urinary excretion (FEenzyme) of gamma-glutamyltranspeptidase (GGT), leucine aminopeptidase (LAP), alkaline phosphatase (AP) and beta-glucuronidase (B-GLU) were quantified in 14 control subjects (group I), 12 cirrhotics with functional renal failure (group II), 13 cirrhotics with renal tubular damage (group III) and 7 non-liver patients with renal tubular damage (group IV). Urinary enzyme excretion and fractional enzyme excretion were significantly higher in the cirrhotics of group III than in the controls or group II. In group III, these tests usually reached values within the range of group IV. The sensitivity of urinary enzyme excretion was 0.92 and specificity ranged from 0.75 (u-LAP) to 1 (u-GGT; u-B-GLU). The sensitivity of fractional enzyme excretion was between 0.61 (FEB-GLU) and 0.84 (FEGGT; FELAP), while specificity was from 0.91 (FELAP; FEAP) to 1 (FEGGT; FEB-GLU). The results indicate that measurement of urinary enzymes may be very useful in diagnosing renal tubular damage in cirrhotic patients with impaired renal function.

Functional properties of isolated hepatocytes from ethanol-treated rat liver

Gluconeogenesis and palmitate incorporation into triacylglycerols and phosphatidylcholine were measured in isolated hepatocytes from control and ethanol-treated rats. Basal gluconeogenesis and its hormonal response decreased in hepatocytes from ethanol-treated animals; palmitate incorporation into triacylglycerols increased. In ethanol-treated rat liver, 45Ca2+ uptake and methylating capacity were reduced, and the hormonal response exhibited differences in binding parameters of insulin.

Deletion of C-terminal amino acid codons of PhiX174 gene E: effect on its lysis inducing properties

The lysis gene E of bacteriophage PhiX174 has been subjected to deletion and fusion analysis. Deletions of 11 to 90% of gene E specific nucleotides coding for to C-terminal region of the gene product were cloned under transcriptional control of lambda pL. For this purpose plasmid pSU1 was constructed which carries an extended polylinker region downstream of pL. Depending on the number of nucleotides after the last gene E specific codon, various C-terminal segments of protein E were replaced by 4, 5, 53 or 314 unrelated amino acids. Functional analysis for lysis inducing properties of the various gene E mutants revealed that the final 9 codons of the gene could be deleted without loss of function. However, replacements of 19 or more C-terminal codons eliminated gene E activity. Although the functional site of the gene E product is located within the N-terminal half of the polypeptide, the C-terminal part of the protein appears to exhibit severe influence on conformation and/or regulation of the functional site.

The fluidity of plasma membranes from ethanol-treated rat liver

Male Wistar rats were maintained for 35-40 days on a liquid diet containing 36% of calories as ethanol. Ethanol was replaced by carbohydrates in the isocaloric diet fed to control animals. The effect of ethanol consumption has been studied on the fluorescence polarization of rat liver plasma membranes and artificial lipid vesicles and on the lipid composition of the membranes. Fluorescence polarization in both membranes and vesicles was determined using DPH and TMA-DPH as fluorescence markers; from these data, the polarization term (ro/r-l)-1 and flow activation energy (delta E) were calculated. The ethanol consumption induces a more fluid environment within the membrane core of liver plasma membranes; the ethanol-fed rat membranes are more resistant to the in vitro effect of ethanol disordering the membrane structure. Vesicles obtained with lipids from either control membranes or ethanol-fed rat membranes were treated with ethanol and the changes in polarization paralleled to those exhibited by the membranes. The absence of phase transitions and of delta E changes was also shown in temperature-dependence studies. The lower cholesterol content found in ethanol-fed rat plasma membranes might be responsible for observed variations in the microviscosity.