Toward solid-state Limetal-air batteries; an SOFC perspective of solid 3D architectures, heterogeneous interfaces, and oxygen exchange kinetics

The full electrification of transportation will require batteries with both 3-5× higher energy densities and a lower cost than what is available in the market today. Energy densities of >1000 W h kg-1 will enable electrification of air transport and are among the very few technologies capable of achieving this energy density. Limetal-O2 or Limetal-air are theoretically able to achieve this energy density and are also capable of reducing the cost of batteries by replacing expensive supply chain constrained cathode materials with "free" air. However, the utilization of liquid electrolytes in the Limetal-O2/Limetal-air battery has presented many obstacles to the optimum performance of this battery including oxidation of the liquid electrolyte and the Limetal anode. In this paper a path towards the development of a Limetal-air battery using a cubic garnet Li7La3Zr2O12 (LLZ) solid-state ceramic electrolyte in a 3D architecture is described including initial cycling results of a Limetal-O2 battery using a recently developed mixed ionic and electronic (MIEC) LLZ in that 3D architecture. This 3D architecture with porous MIEC structures for the O2/air cathode is essentially the same as a solid oxide fuel cell (SOFC) indicating the importance of leveraging SOFC technology in the development of solid-state Limetal-O2/air batteries.

Bothersome Hot Flashes Following Neoadjuvant Androgen Deprivation Therapy and Stereotactic Body Radiotherapy for Localized Prostate Cancer

PURPOSE/OBJECTIVE(S)

Androgen deprivation therapy (ADT) may improve cancer control in unfavorable localized prostate cancer treated with stereotactic body radiotherapy (SBRT). ADT is known to cause hormonally related symptoms that resolve with testosterone recovery. Hot flashes are particularly burdensome. This study sought to evaluate the timeline of hot flashes following short-course ADT and SBRT as well as its relationship with testosterone recovery.

MATERIALS/METHODS

Institutional IRB approval was obtained for this retrospective review of prospectively collected data (IRB#: 2009-510). ADT was initiated three months prior to the start of SBRT. Hot flashes were self-reported via question 13a a healthcare software prior to ADT initiation, the first day of robotic SBRT, and at each follow-up (1, 3, 6, 9, 12, 18, 24 and 36 months). The responses were grouped into three relevant categories (no problem, very small-small problem and moderate-big problem). Scores were transformed to a 0-100 scale with higher scores reflecting less bother. Testosterone levels were measured at each follow-up.

RESULTS

From 2007 to 2010, 122 localized prostate cancer patients (9 low-, 64 intermediate-, and 49 high-risk according to the D'Amico classification) at a median age of 72 years (range 54.5-88.3) were treated with short course ADT (3-6 months) and SBRT (35-36.25 Gy) at Georgetown University Hospital. Thirty-two percent were black and 27% were obese. 77% of patient received three months of ADT. At baseline, 2% of men experienced hot flashes that were a "moderate to big problem" and that proportion peaked at the start of SBRT (45%) before returning to baseline 9 months post-SBRT with a cumulative incidence of 52.4%. The median baseline healthcare software hot flash score of 94 declined to 50 at the start of SBRT but this returned to baseline by six months post SBRT. These changes were both statistically and clinically significant (MID = 9.5083). Testosterone recovery (> 230 ng/dL) occurred in approximately 70% of patients by 12 months post SBRT. Resolution of hot flashes correlated with testosterone recovery.

CONCLUSION

Bothersome hot flashes occur in greater than 50% of men treated with neoadjuvant ADT. Resolution of hot flashes occurs in the majority of patients within one year after treatment. Reassurance of the temporary nature of hot flashes may assist in reducing patient anxiety. Measuring testosterone levels at follow-up visits may allow for anticipatory counseling that may limit the associated bother.

Bothersome Gynecomastia Following Neoadjuvant GnRH Agonists and Stereotactic Body Radiotherapy for Localized Prostate Cancer

PURPOSE/OBJECTIVE(S)

Androgen deprivation therapy (ADT) is increasingly utilized in combination with stereotactic body radiotherapy (SBRT) for unfavorable prostate cancer. ADT such as gonadotropin releasing hormone (GnRH) agonists are known to cause hormonal-related side effects such as gynecomastia. The incidence of bothersome breast tenderness and/or enlargement following short course GnRH agonists and SBRT is unknown. This study sought to evaluate the timeline of gynecomastia as well as its relationship with testosterone recovery.

MATERIALS/METHODS

Gynecomastia was self-reported via question 13b of a healthcare software prior to ADT initiation, the first day of robotic SBRT, and at each follow-up (1, 3, 6, 9, 12, 18, 24 and 36 months). The responses were grouped into three relevant categories (no problem, very small-small problem, and moderate-big problem). Scores were transformed to a 0-100 scale with higher scores reflecting less bother. Testosterone levels were measured at each follow-up.

RESULTS

From 2007 to 2010, 122 localized prostate cancer patients (9 low-, 64 intermediate-, and 49 high-risk according to the D'Amico classification) at a median age of 72 years (range 54.5-88.3) were treated with short course ADT (3-6 months) and SBRT (35-36.25 Gy) at Georgetown University Hospital. Of the participants, 48% percent were non-white and 48% were overweight. 77% of patients received three months of ADT. At baseline, 2% of men experienced gynecomastia that was a "moderate to big problem" and that proportion peaked at 3 and 12 months post-SBRT (7%) before returning to less than baseline (0%) 24 months post-SBRT with a cumulative incidence of 14.75%. The median baseline healthcare software hot flash score of 98 declined to 90 at 3 months post-SBRT but this returned to baseline by 24 months post SBRT. These changes were both statistically and clinically significant (MID = 6.5). Testosterone recovery (> 230 ng/dL) occurred in approximately 70% of patients by 12 months post SBRT. The development and resolution of gynecomastia fluctuated at various timepoints and did not directly correlate with testosterone recovery.

CONCLUSION

Bothersome gynecomastia occurs in less than 15% of men treated with neoadjuvant ADT. Resolution of gynecomastia occurs in most patients within two years after treatment. Reassurance of the temporary nature of gynecomastia may assist in reducing patient anxiety. Institutional IRB (IRB#: 2009-510) approval was obtained for retrospective review of prospectively collected data.

Low Incidence of Late Lymphopenia Following Stereotactic Body Radiotherapy for Localized Prostate Cancer

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) is increasing in use for the treatment of localized prostate cancer. The utilization of highly conformal photon therapy such as SBRT may increase the whole-body integral dose. Lymphocytes are very radiation sensitive. This dose increase could lead to unintended consequences such as lymphopenia. Prior studies have shown that lymphopenia following radiation therapy may negatively impact long-term outcomes. This study sought to evaluate the incidence and timeline of chronic lymphopenia following prostate SBRT.

MATERIALS/METHODS

Institutional IRB (IRB#: 2012-1175) approval was obtained. The absolute lymphocyte count was measured 1-2 hours prior to robotic SBRT (35-36.25 Gy in 5 fractions) and at each follow-up (3, 6, 12, 18 and 24 months). Lymphopenia was graded using the CTCAEv.4: Grade 1 (1.0-0.8 k/μl), Grade 2 (0.8-0.5 k/μl), Grade 3 (0.5-0.2 k/μl) and Grade 4 (<0.2 k/μl). Late lymphopenia was defined as lymphopenia occurring 3 or more months post-SBRT.

RESULTS

From 2019 to 2022, 198 localized prostate cancer patients (23 low-, 148 intermediate-, and 27 high-risk according to the D'Amico classification) at a median age of 73.5 years were treated with SBRT (35-36.25 Gy) at Georgetown University Hospital on a prospective clinical trial. Baseline lymphopenia was uncommon: Grade 1 (3.5%), Grade 2 (1.5%) and Grade 3 (0%). The baseline ALC of 1.9 k/μl decreased to 1.5 k/μl at 3 months post-SBRT and then remained stable for the remainder of the two-year follow-up. Overall, 14.6% of men experienced lymphopenia in the two years following SBRT: Grade 1 (7.6%), Grade 2 (6.6%) and Grade 3 (0.5%). No patient experienced Grade 4 lymphopenia.

CONCLUSION

Prostate SBRT leads to a low rate of late lymphopenia with the vast majority of toxicities being low grade. The peak incidence occurred at 3 months post-SBRT. Resolution of lymphopenia occurs in most patients within two years after SBRT. Future studies should explore the possible impact on quality of life and cancer control outcomes.

Finite element derived femoral strength is a better predictor of hip fracture risk than aBMD in the AGES Reykjavik study cohort

Hip fractures associated with a high economic burden, loss of independence, and a high rate of post-fracture mortality, are a major health concern for modern societies. Areal bone mineral density is the current clinical metric of choice when assessing an individual's future risk of fracture. However, this metric has been shown to lack sensitivity and specificity in the targeted selection of individuals for preventive interventions. Although femoral strength derived from computed tomography based finite element models has been proposed as an alternative based on its superior femoral strength prediction ex vivo, such predictions have only shown marginal or no improvement for assessing hip fracture risk. This study compares finite element derived femoral strength to aBMD as a metric for hip fracture risk assessment in subjects (N = 601) from the AGES Reykjavik Study cohort and analyses the dependence of femoral strength predictions and classification accuracy on the material model and femoral loading alignment. We found hip fracture classification based on finite element derived femoral strength to be significantly improved compared to aBMD. Finite element models with non-linear material models performed better at classifying hip fractures compared to finite element models with linear material models and loading alignments with low internal rotation and adduction, which do not correspond to weak femur alignments, were found to be most suitable for hip fracture classification.

Patient delay and benefit of timely reperfusion in ST-segment elevation myocardial infarction

Background

In patients with ST-segment elevation myocardial infarction (STEMI), it is unknown how patient delay modulates the beneficial effects of timely reperfusion.

Aims

To assess the prognostic significance of a contact-to-balloon time of less than 90 min on in-hospital mortality in different categories of symptom-onset-to-first-medical-contact (S2C) times.

Methods

A total of 20 005 consecutive patients from the Feedback Intervention and Treatment Times in ST-segment Elevation Myocardial Infarction (FITT-STEMI) programme treated with primary percutaneous coronary intervention (PCI) were included.

Results

There were 1554 deaths (7.8%) with a J-shaped relationship between mortality and S2C time. Mortality was 10.0% in patients presenting within 1 hour, and 4.9%, 6.0% and 7.3% in patient groups with longer S2C intervals of 1–2 hours, 2–6 hours and 6–24 hours, respectively. Patients with a short S2C interval of less than 1 hour (S2C<60 min) had the highest survival benefit from timely reperfusion with PCI within 90 min (OR 0.27, 95% CI 0.23 to 0.31, p<0.0001) as compared with the three groups with longer S2C intervals of 1 hour<S2C≤2 hours (OR 0.44, 95% CI 0.33 to 0.59, p<0.0001), 2 hours<S2C≤6 hours (OR 0.49, 95% CI 0.38 to 0.64, p<0.0001) and 6 hours<S2C≤24 hours (OR 0.42, 95% CI 0.30 to 0.58, p<0.0001).

Conclusions

Timely reperfusion with a contact-to-balloon time of less than 90 min is most effective in patients presenting with short S2C intervals of less than 1 hour, but has also beneficial effects in patients with S2C intervals of up to 24 hours.

Trial registration number

NCT00794001.

Novel porous scaffolds of pH responsive chitosan/carrageenan-based polyelectrolyte complexes for tissue engineering

Polyelectrolyte complexes (PECs) represent promising materials for drug delivery and tissue engineering applications. These substances are obtained in aqueous medium without the need for crosslinking agents. PECs can be produced through the combination of oppositely charged medical grade polymers, which include the stimuli responsive ones. In this work, three-dimensional porous scaffolds were produced through the lyophilization of pH sensitive PECs made of chitosan (CS) and carrageenan (CRG). CS:CRG molar ratios of 1:1 (CSCRG1), 2:1 (CSCRG2), and 3:1 (CSCRG3) were used. The chemical compositions of the PECs, as well as their influence in the final structure of the scaffolds were meticulously studied. In addition, the pH responsiveness of the PECs in a range including the physiological pH values of 7.4 (simulating normal physiological conditions) and 4.5 (simulating inflammatory response) was assessed. Results showed that the PECs produced were stable at pH values of 7.4 and under but dissolved as the pH increased to nonphysiological values of 9 and 11. However, after dissolution, the PEC could be reprecipitated by decreasing the pH to values close to 4.5. The scaffolds obtained presented large and interconnected pores, being equally sensitive to changes in the pH. CSCRG1 scaffolds appeared to have higher hydrophilicity and therefore higher water absorption capacity. The increase in the CS:CRG molar ratios improved the scaffold mechanical properties, with CSCRG3 presenting the higher compressive modulus under wet conditions. Overall, the PEC scaffolds appear promising for tissue engineering related applications that require the use of pH responsive materials stable at physiological conditions.

Validity of cardiac implantable electronic devices in assessing daily physical activity

BACKGROUND

Data on physical activity assessed by cardiac implantable electronic devices (ICD/CRT) have been used for prognostic implications in heart failure patients, but no study has ever compared these data to validated external accelerometers.

METHODS

73 ICD/CRT recipients (age 60 ± 20 years, 21% female) received a validated external accelerometer over a period of 7 days. Thereafter, data on physical activity of both ICD/CRT and external accelerometers were retrieved and compared using Spearman's rank correlation coefficient and Bland Altman plots.

RESULTS

Mean total daily activity was 276 ± 85 min (range 72-462) as assessed by the external accelerometers and 237 ± 105 min (28-575) as assessed by the ICD/CRT activity sensors (p<0.001). A strong, significant intra-individual correlation (r>0.7) between the two measurements was observed in a majority (70%) of patients (p<0.05 each). However, a Bland Altman plot revealed a broad variation of total daily activity between both methods (95% limits of agreement -225 to 147 min), resulting in differences in the duration of daily activity up to several hours. In multivariate regression analysis, no influence of age, NYHA functional class, left ventricular ejection fraction, underlying disease or type of device on these differences was observed.

CONCLUSIONS

As compared to a validated external accelerometer, daily physical activity assessed by ICD/CRT devices shows strong intra-individual correlations, but differs substantially regarding the absolute amount of daily activity. Thus, using ICD/CRT activity data for more precise clinical or prognostic information without prior validation is of limited value.

[IQWiG's methods for the cost-benefit assessment : Comparison with an international reference scenario]

Standardization of international health economic guidelines has been repeatedly requested. In this context, an international reference case was proposed, which constitutes an agreed approach for the key elements of health economic evaluation including study perspective, comparators, source of effectiveness data, role of modeling, main (economic) outcome, source of utilities, characterizing uncertainty. It is, however, questionable whether such a reference scenario can reasonably be applied across all health care systems. Our analysis pursues the question to which degree the Institute for Quality and Efficiency in Health Care's (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen, IQWiG) "General methods for evaluating the relation between cost and benefit" comply with the key elements of the reference case. In case of divergences, they will be described and discussed in light of the German social legislation and in consideration of current scientific evidence. In conclusion, the analysis revealed that IQWiG complied with the reference case in almost all aspects. Differences were found only with respect to the choice of main (economic) outcome and the source of utilities. These differences seem justified and well explained in the context of the German social legislation as well as in view of the weaknesses of the quality-adjusted life year (QALY) concept.

[Epigastric pain and abnormal ECG]

We report on a 50-year old man who presented with upper abdominal pain and new T-wave inversions in the anterior leads of the electrocardiogramm. Since the patient additionally had cardiovascular risk factors (positive family history, smoking, hypercholesterinemia and hypertension) he was initially thought to have an acute coronary syndrome. Moreover, he had elevated serum levels of amylase and lipase, and together with typical findings of abdominal ultrasound he was diagnosed with acute pancreatitis responsible for the patient's pain. The ECG changes persisted during the hospital stay, but had fully normalised three weeks later. Further cardiologic evaluation yielded normal results. Thus, the ECG-abnormalities could be attributed to the acute pancreatitis, which can cause ECG-pathologies mimicking an acute coronary syndrome in up to 30%. Knowledge of there findings is important in order to prevent wrong therapeutic decisions.

Cost-effectiveness of primary and secondary prevention in cardiovascular diseases

INTRODUCTION, AIMS, AND METHODS: Industrial countries' societies are challenged to counter the increasing costs of health care. The preponderance of cardiovascular diseases in middle-aged people demands new strategies to reduce the extremely high rates of early deaths and increased morbidity and thus to avert considerable costs. Prevention programmes are appropriate means to combine therapeutic needs with health economic goals. A review of techniques of economic evaluation is given, from which a critical appraisal of cost-effectiveness analyses in primary and secondary prevention with HMG-CoA reductase inhibitors in coronary heart disease follows. Our own analysis of cost-effectiveness of primary prevention based on the clinical results of the WOSCOP study is also presented.

RESULTS AND CONCLUSIONS

Long-term treatment with HMG-CoA reductase inhibitors is effective (30% mortality reduction), safe and tolerable. With a cost-effectiveness ratio of DM15,000-25,000/life-year saved ($9000-15,000) it can be recommended for secondary prevention. The application of statins in primary prevention has also proved to be clinically effective. But with a cost-effectiveness ratio of DM330,000/life-year saved ($195,000) they cannot be generally advocated in patients with hypercholesterolaemia. However, the treatment has to be considered for high risk patients. Aspirin prevention seems to be an alternative in patients without additional risk factors.

Mechanism of phage P22 tailspike protein folding mutations

Temperature-sensitive folding (tsf) and global-tsf-suppressor (su) point mutations affect the folding yields of the trimeric, thermostable phage P22 tailspike endorhamnosidase at elevated temperature, both in vivo and in vitro, but they have little effect on function and stability of the native folded protein. To delineate the mechanism by which these mutations modify the partitioning between productive folding and off-pathway aggregation, the kinetics of refolding after dilution from acid-urea solutions and the thermal stability of folding intermediates were analyzed. The study included five tsf mutations of varying severity, the two known su mutations, and four tsf/su double mutants. At low temperature (10 degrees C), subunit-folding rates, measured as an increase in fluorescence, were similar for wild-type and mutants. At 25 degrees C, however, tsf mutations reduced the rate of subunit folding. The su mutations increased this rate, when present in the tsf-mutant background, but had no effect in the wild-type background. Conversely, tsf mutations accelerated, and su mutations retarded the irreversible off-pathway reaction, as revealed by temperature down-shifts after varied times during refolding at high temperature (40 degrees C). The kinetic results are consistent with tsf mutations destabilizing and su mutations stabilizing an essential subunit folding intermediate. In accordance with this interpretation, tsf mutations decreased, and su mutations increased the temperature resistance of folding intermediates, as disclosed by temperature up-shifts during refolding at 25 degrees C. The stabilizing and destabilizing effects were most pronounced early during refolding. However, they were not limited to subunit-folding intermediates and were also observable during thermal unfolding of the native protein.

Temperature-sensitive mutations and second-site suppressor substitutions affect folding of the P22 tailspike protein in vitro

One of the central problems in protein folding is how amino acid sequences within polypeptide chains direct polypeptide chain folding and avoid off-pathway aggregation both in intracellular environments and in the test tube. The tailspike protein of phage P22 is a model system for which genetic analysis has permitted mutational dissection of the role of amino acid positions in the polypeptide chain in directing its in vivo folding. Two classes of mutations that affect intracellular folding and aggregation have been characterized; temperature-sensitive folding (tsf) mutants and second-site suppressors of tsf mutants. Here we report the effects of these mutations on the in vitro refolding and aggregation pathway of the purified proteins. The tsf mutations reduced refolding yields at high temperature and increased aggregation, while second-site suppressors enhanced refolding and inhibited aggregation in the test tube. For both types of mutations, the strength of the effects observed in vitro correlated with their in vivo phenotypes. The results confirm that the mutations act intrinsically on the folding pathway of the tailspike polypeptide and not through accessory proteins.

Folding and assembly of phage P22 tailspike endorhamnosidase lacking the N-terminal, head-binding domain

Tryptic digestion of a thermal unfolding intermediate of the phage P22 tailspike endorhamnosidase produces an N-terminally shortened protein fragment comprising amino-acid residues 108-666 [Chen, B.-L. & King, J. (1991) Biochemistry 30, 6260-6269]. In the present work, the 60-kDa C-terminal fragment was purified to homogeneity from the tryptic digest by gel-fitration chromatography. As in the case for the whole tailspike protein (72 kDa), the purified fragment was found to remain stably folded as a highly soluble, SDS-resistant, enzymatically active trimer. However, its unfolding in the presence of guanidinium chloride was accelerated at least 10-fold compared to the complete, native tailspike protein. Shortened tailspike trimers reconstituted spontaneously and with high yield after diluting a solution containing acid-urea-unfolded fragment polypeptides with neutral buffer. Upon recombinant expression of the 60-kDa polypeptide in Escherichia coli, it also assembled efficiently and formed SDS-resistant trimers. The refolding and assembly pathway of the N-terminally shortened tailspike paralleled that of the complete protein with slightly, but significantly, accelerated folding reactions, at both the subunit and the trimer levels. As found for the complete tailspike protein, yields of refolding and assembly of the 60-kDa fragments into SDS-resistant trimers decreased with increasing temperature. The refolding yield of fragments derived from a temperature-sensitive mutant (Gly244-->Arg) tailspike protein was affected in similar fashion as shown for the whole protein. We conclude that the N-terminal domain (residues 1-107) is dispensable for folding and assembly of the P22 tailspike endorhamnosidase both in vitro and in vivo.

Interactions of phage P22 tailspike protein with GroE molecular chaperones during refolding in vitro

Because efficient folding in vivo and reconstitution in vitro of phage P22 tailspike protein is temperature-sensitive, and because a chaperone function of the GroE proteins for tailspike folding in vivo has been suggested by genetic observations, the interactions of purified Escherichia coli GroE proteins with phage P22 tailspikes during refolding in vitro were investigated. At elevated temperature (> 30 degrees C), in the absence of ATP, GroEL effectively trapped refolding tailspike protein and prevented reconstitution. Tailspike protein was released from GroEL by addition of ATP around 35 degrees C or without added ATP upon cooling to 25 degrees C, and native tailspike trimers were formed. In accordance with the cold release, tailspike reconstitution at < or = 25 degrees C was unaffected by GroE. No formation of native tailspike trimers was observed, when refolding was initiated at 42 degrees C in the presence of the GroE proteins and ATP or when tailspike protein was dissociated from a preformed complex with the chaperone by addition of ATP at 42 degrees C. In contrast to other GroE ligands, the tailspike polypeptide was bound by and released from GroE in similar states of folding, and the presence of GroES in addition to GroEL had no effect on reconstitution yields at any temperature. Thus, the GroE proteins may exhibit widely differing interactions even with proteins showing similarly temperature-sensitive yields of folding.

Human granulocyte-macrophage colony stimulating factor: an effective direct activator of human polymorphonuclear neutrophilic granulocytes

Granulocyte-macrophage colony-stimulating factor (GM-CSF) was shown to modulate different granulocyte functions. In the present study we investigated the effect of purified and recombinant human GM-CSF, particularly on the oxidative metabolism of isolated human granulocytes. In addition, ultrastructural changes upon stimulation were evaluated. For detection of granulocyte activation the following assay systems were used: 1) lucigenin-dependent chemiluminescence (CL), 2) superoxide-dismutase (SOD) inhibitable cytochrome C-reduction (superoxide), 3) horseradish peroxidase-mediated oxidation of phenol red (hydrogen peroxide), 4) release of myeloperoxidase, 5) ultrastructural detection of hydrogen peroxide-production, and 6) scanning and transmission electron microscopy (SEM and TEM, respectively). A significant CL response was seen upon stimulation with recombinant human GM-CSF at concentrations ranging from 1 to 10(3) U/ml. The CL response started within 5-10 min with a maximum at 60-90 min and lasted more than 3 h. Thereafter granulocytes were completely deactivated to restimulation with the same mediator and with Tumor Necrosis Factor, but responded to other triggers of the oxidative burst, whereas the response to f-met-leu-phe was significantly increased. The CL signal was completely blocked by an antiserum to GM-CSF. Moreover, the response was significantly inhibited by SOD and D-Mannitol, suggesting the involvement of distinct reactive oxygen species (ROS) in generating the CL response. Significant amounts of superoxide were detected within 180 min after stimulation with GM-CSF, whereas release of hydrogen peroxide and peroxidase were only minimal as shown by functional and ultrastructural assays. Activation of granulocytes could be visualized by SEM and TEM. GM-CSF stimulated cells showed an increased adherence to the substratum developing polarized filopodia and an increased number of intracellular vesicles within 30 min after addition of the stimulus. The results clearly demonstrate that GM-CSF directly stimulates granulocytes and, particularly, their oxidative metabolism. Therefore, GM-CSF which is probably released by epidermal cells appears to be a candidate for neutrophil activation in the skin, and thereby may play a crucial role in inflammatory skin diseases.

Granulocyte-activating mediators (GRAM). II. Generation by human epidermal cells--relation to GM-CSF

In the present study we investigated the capability of human epidermal cells to generate granulocyte-activating mediators (GRAM). It could be shown that human epidermal cells as well as an epidermoid carcinoma cell line (A431) produce an epidermal cell-derived granulocyte-activating mediator (EC-GRAM) which stimulates human granulocytes to release significant levels of toxic oxygen radicals as measured by a lucigenin-dependent chemiluminescence (CL). For further characterization of EC-GRAM the A431 cell line was used. Supernatants of A431 cells usually contained maximal EC-GRAM levels within 24 h of incubation. Factor production was enhanced by bacterial lipopolysaccharide (LPS), but not by silica particles and PHA. Moreover, freeze-thaw lysates of A431 cells and extracts of heat-separated human epidermis contained significant levels of EC-GRAM. Preincubation of granulocytes with EC-GRAM resulted in an enhanced response to subsequent stimulation with the chemotactic peptide f-met-phe. In contrast EC-GRAM did not affect the response to PMA or zymosan particles. However, EC-GRAM treated granulocytes were unresponsive to restimulation with EC-GRAM. Upon high performance liquid chromatography (HPLC) gel filtration EC-GRAM eluted within two major peaks exhibiting a molecular weight of 17 kD and 44 kD.(ABSTRACT TRUNCATED AT 250 WORDS)

Human keratinocytes and epidermoid carcinoma cell lines produce a cytokine with interleukin 3-like activity

Keratinocytes are capable of releasing distinct immunomodulating cytokines such as epidermal cell-derived thymocyte activating factor (ETAF) and an epidermal cell-derived natural killer cell augmenting factor (ENKAF). The present study was performed to determine whether human keratinocytes also may secrete an interleukin 3 (IL-3)-like mediator and thereby participate in the regulation of mast cell activity in the skin. Supernatants of freshly isolated human epidermal cells (EC) and malignant keratinocyte cell lines (A 431, SCC) were tested for their capacity to induce the proliferation of IL-3-dependent cell lines 32 DCL and FDCP. Human epidermal cell interleukin 3 (EC IL-3) is spontaneously released by freshly isolated EC, A 431, and squamous cell carcinoma (SCC) cells. However, both normal EC and A 431 cells produced increased levels of EC IL-3 activity when cultured in the presence of different stimulants, such as phorbol myristate acetate and lipopolysaccharide. The EC IL-3 activity was not inhibited when treated with a monoclonal anti-IL-1 or anti-IL-2-antibody. Biochemical characterization showed that human EC IL-3 has a molecular weight of 17K, elutes of DEAE-ion exchange high-performance liquid chromatography (HPLC) as one major peak at 0.36 M NaCl, and upon HPLC-chromatofocusing exhibits 3 isoelectric points of 7.8, 7.5, and 5.6. Upon reversed-phase HPLC, EC IL-3 activity eluted at about 100% acetonitrile. When highly purified EC IL-3 was labeled with 125I and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, a single homogeneous band exhibiting a molecular weight of 17K was seen, which correlated with the IL-3 activity and was free of ETAF/IL-1, IL-2, and interferon activity. These data indicate that human EC synthesize an IL-3-like cytokine which is distinct from ETAF/IL-1, IL-2, and interferon and thereby may participate in the regulation of mast cell activity during inflammatory and fibrotic, as well as hypersensitivity reactions.

Monoclonal anti-IL 1 is directed against a common site of human IL 1 alpha and IL 1 beta

Cytokines exhibiting interleukin 1 (IL 1) activity are known as important mediators of immunity and inflammation. Therefore, the ability of a monoclonal anti-IL 1 antibody to neutralize and bind IL 1 was investigated. Anti-IL 1 IgG blocked the IL 1-mediated thymocyte and fibroblast proliferation and also inhibited the biological activity of epidermal cell-derived thymocyte activating factor (ETAF), but did not affect interleukin 2 (IL 2) and interleukin 3 (IL 3) activity. Monoclonal anti-IL 1 blocked the activity and bound to both human IL 1 alpha and IL 1 beta. Additionally using anti-IL 1, it was possible to immunoprecipitate 31 kD, 17 kD and 4 kD biosynthetically radiolabeled biologically active species of IL 1. These data indicate that IL 1 alpha and IL 1 beta share a common site which is responsible for the biological activity. Moreover, this part of the IL 1 molecule also appears to be located within the low mw 4 kD break-down product. Since anti-IL 1 also was capable to detect surface bound IL 1 on LPS-stimulated mononuclear adherent cells, the antibody may help to elucidate the role of surface IL 1 during an immune response. In addition, anti-IL 1 IgG may be very helpful to investigate the in vivo role of IL 1 during the pathogenesis of inflammatory diseases.

Characterization of a monoclonal antibody directed against the biologically active site of human interleukin 1

Human IL-1 was successfully used to produce an anti-IL-1 mAb. Anti-IL-1 (IgG2a) blocked IL-1-mediated thymocyte and fibroblast proliferation, but did not interfere with the biological effects of other lymphokines, such as IL-2 or IL-3. The antibody immunoprecipitated biosynthetically radiolabeled 33, 17, and 4 kD IL-1. An immunoadsorbent column yielded 20% of initial activity, and upon HPLC size-exclusion chromatography, affinity-purified IL-1 had a molecular mass of approximately 4 kD. These results provide first evidence of a monoclonal anti-IL-1 that reacts with different species of IL-1 and apparently binds to an epitope close to the active site of IL-1. Thus, anti-IL-1 IgG may be very helpful for further investigations of the molecular as well as biological characteristics of IL-1 and related mediators.

Characterization of immunoregulatory cytokines produced by epidermal cells

The epidermis has been identified as an important site for the initiation of immunological events. In addition to the macrophage-like Langerhans cells, keratinocytes within the epidermal cells have been shown to act as immunoregulatory cells through the secretion of cytokines such as epidermal cell-derived thymocyte-activating factor (ETAF) and interleukin 3. Epidermal cell-derived interleukin 3 (EC IL-3), like lymphocyte-derived IL-3, induced the proliferation of IL-3-dependent mast cell-like cell lines. Biochemically, EC IL-3 was a heat-stable protein with a molecular weight of approximately 30 kD. Upon chromatofocusing, EC IL-3 exhibited three isoelectric points, at pI 7.8, 7.4, and 7.1. Furthermore, an antiserum against IL-3 neutralized EC IL-3 activity, suggesting that the molecules are closely related and share similar epitopes. ETAF-like macrophage-derived interleukin 1 (IL-1) is a low molecular weight protein with a multiplicity of amplifying effects on immunological and inflammatory reactions. Thus BALB/c mice were immunized with partially purified IL-1, and immune spleen cells were hybridized with plasmocytoma cells. Supernatants of the hybridoma cultures were screened for their capacity to inhibit IL-1-induced thymocyte proliferation. After expansion and cloning, one clone was selected for ascitic antibody production. The monoclonal anti-IL-1 antibody inhibited both the IL-1-dependent thymocyte and the fibroblast proliferation. Furthermore, the antibody blocked murine and human ETAF activity, suggesting that ETAF and IL-1 share antigenically similar domains. Moreover, by using the monoclonal antibody bound to Staphylococcus aureus cells, it was possible to immunoprecipitate IL-1. In contrast, anti-IL-1 antibody did not inhibit IL-2 or IL-3 activity. These findings demonstrate that the production of immunoregulatory cytokines is not confined to cells of the immune system and that keratinocytes through the production of ETAF and EC IL-3 may mediate inflammatory and hypersensitivity reactions. Furthermore, the monoclonal anti-IL-1 antibody may provide a useful tool for the development of new immunoassays to detect IL-1/ETAF and thereby facilitate the investigation of the role of these cytokines during the pathogenesis of inflammatory diseases.

[Effect of air-electric fields on driving and reaction patterns. Test subjects in the car driving simulator (author's transl)]

In the relevant frequency range of about 10 Hertz cars can be considered very largely as Faraday cages and consequently as screens against air-electric fields. This may have a negative influence on driving and reaction patterns as a result. In an extensive investigation 48 subjects in a driving simulator were exposed to definite artificially produced air-electric fields. The self-rating of the performance and concentration of the subjects, reaction times and driving errors were determined. While the reaction times remained practically constant, the driving behavior of the subjects improved.