Effects of MAPK and PI3K pathways on PD-L1 expression in melanoma

PURPOSE

PD-L1 is the main ligand for the immune inhibitory receptor PD-1. This ligand is frequently expressed by melanoma cells. In this study, we investigated whether PD-L1 expression is controlled by melanoma driver mutations and modified by oncogenic signaling inhibition.

EXPERIMENTAL DESIGN

Expression of PD-L1 was investigated in a panel of 51 melanoma cell lines containing different oncogenic mutations, including cell lines with innate and acquired resistance to BRAF inhibitors (BRAFi). The effects of targeted therapy drugs on expression of PD-L1 by melanoma cells were investigated.

RESULTS

No association was found between the level of PD-L1 expression and mutations in BRAF, NRAS, PTEN, or amplification of AKT. Resistance to vemurafenib due to the activation of alternative signaling pathways was accompanied with the induction of PD-L1 expression, whereas the resistance due to the reactivation of the MAPK pathway had no effect on PD-L1 expression. In melanoma cell lines, the effects of BRAF, MEK, and PI3K inhibitors on expression of PD-L1 were variable from reduction to induction, particularly in the presence of INFγ. In PD-L1-exposed lymphocytes, vemurafenib paradoxically restored activity of the MAPK pathway and increased the secretion of cytokines.

CONCLUSIONS

In melanoma cell lines, including BRAFi-resistant cells, PD-L1 expression is variably regulated by oncogenic signaling pathways. PD-L1-exposed lymphocytes decrease MAPK signaling, which is corrected by exposure to vemurafenib, providing potential benefits of combining this drug with immunotherapies.

How evidence based are recruitment strategies to randomized controlled trials in primary care? Experience from seven studies

BACKGROUND

Failure to recruit adequate numbers of participants represents a major barrier to the completion of randomized controlled trials in primary care and is associated with substantial opportunity costs. However, uncertainty exists regarding the relative effectiveness of different methods to promote recruitment.

OBJECTIVES

The purpose of this study was to estimate the proportion of strategies used to promote patient recruitment to randomized controlled trials in primary care that are evidence based.

METHODS

Investigators from seven primary care-based clinical trials of dyspepsia management aiming to recruit a total of 6070 patients participated. Following a survey of trial organization, a Delphi technique was used to reach consensus on levels of evidence on the effectiveness of interventions or organizational characteristics in influencing recruitment. The main outcome measures were the proportions of interventions or organizational characteristics for influencing patient recruitment that are based upon randomized controlled trials, on convincing non-experimental evidence or meeting neither of these criteria.

RESULTS

Out of a total of 56 interventions used across the trials, 35 (63%) were judged as evidence based. Out of a total of 29 organizational characteristics possessed by the trials, five (17%) were judged as evidence based. Across the seven dyspepsia trials, the presence of 'favourable' organizational characteristics appeared to be important contributors towards successful recruitment.

CONCLUSIONS

A wide range of interventions and organizational characteristics with the potential to promote recruitment were used or possessed by seven primary care trials. Many were not evidence based. Our experience suggests that organizational characteristics could be more influential in trial recruitment than the use of specific interventions. Given the costs of primary care-based trials, researchers need more rigorous evidence to inform recruitment strategies.

Antitumor activity of the ERK inhibitor SCH772984 [corrected] against BRAF mutant, NRAS mutant and wild-type melanoma

Background

In melanoma, dysregulation of the MAPK pathway, usually via BRAF^V600 or NRAS^Q61 somatic mutations, leads to constitutive ERK signaling. While BRAF inhibitors are initially effective for BRAF-mutant melanoma, no FDA-approved targeted therapies exist for BRAF-inhibitor-resistant BRAF^V600, NRAS mutant, or wild-type melanoma.

Methods

The 50% inhibitory concentration (IC50) of SCH772984, a novel inhibitor of ERK1/2, was determined in a panel of 50 melanoma cell lines. Effects on MAPK and AKT signaling by western blotting and cell cycle by flow cytometry were determined.

Results

Sensitivity fell into three groups: sensitive, 50% inhibitory concentration (IC₅₀) < 1 μM; intermediately sensitive, IC₅₀ 1-2 μM; and resistant, >2 μM. Fifteen of 21 (71%) BRAF mutants, including 4 with innate vemurafenib resistance, were sensitive to SCH772984. All three (100%) BRAF/NRAS double mutants, 11 of 14 (78%) NRAS mutants and 5 of 7 (71%) wild-type melanomas were sensitive. Among BRAF^V600 mutants with in vitro acquired resistance to vemurafenib, those with MAPK pathway reactivation as the mechanism of resistance were sensitive to SCH772984. SCH772984 caused G1 arrest and induced apoptosis.

Conclusions

Combining vemurafenib and SCH722984 in BRAF mutant melanoma was synergistic in a majority of cell lines and significantly delayed the onset of acquired resistance in long term in vitro assays. Therefore, SCH772984 may be clinically applicable as a treatment for non-BRAF mutant melanoma or in BRAF-mutant melanoma with innate or acquired resistance, alone or in combination with BRAF inhibitors.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-4598-13-194) contains supplementary material, which is available to authorized users.

Processing of Toxoplasma ROP1 protein in nascent rhoptries

Secretion in the obligate intracellular parasite, Toxoplasma gondii, occurs through a number of regulated compartments. Among these are the apical organelles known as rhoptries which release their contents as part of the invasion process. We are interested in the processing, targeting and ultimate function of rhoptry proteins (and have focused our analyses on rhoptry protein 1 (ROP1). In this paper, we address the issue of processing: using a number of engineered forms of the ROP1 gene (introduced into a ROP1- background), we show that ROP1 is synthesized as a pre-pro-protein that is subject to proteolytic cleavages to remove the pre-sequence and the 'pro' region, at the N-terminus. Using brefeldin A (BFA) and reduced temperature we show that this processing occurs late in the secretory pathway of the parasite. Immunolocalization studies with epitope-tagged constructs indicate that processing is apparently occurring in the nascent rhoptries of dividing parasites. The results are discussed in the context of the targeting and possible function of the ROP1 protein.

Hepatitis C in dialysis patients: relationship to blood transfusions, dialysis and liver disease

Antibodies to hepatitis C virus (anti-HCV) were determined in an unselected group of 340 patients with chronic renal failure treated with maintenance dialysis. A second generation hepatitis C virus (HCV) enzyme-linked immunosorbent assay (ELISA) was used and confirmation made by a second generation recombinant immunoblot assay (RIBA). Sixteen patients (4.7%) were anti-HCV positive and 8 (2.4%) were anti-HCV indeterminate. All anti-HCV positive and anti-HCV indeterminate patients had received blood transfusions. No statistically significant differences were found between anti-HCV positive and indeterminate patients considering blood transfusions, dialysis and liver disease. The combined group of anti-HCV positive and indeterminate patients had had more blood transfusions (P < 0.005) and had been on dialysis for a longer period (P < 0.01) compared with anti-HCV negative patients. Further, significant correlation with elevation of transaminases and anti-HCV was observed (P < 0.001). Thirty patients (8.8%) had elevated transaminase levels and 13 (43%) of these were anti-HCV positive or indeterminate. In conclusion, HCV infection accounts for a substantial proportion of liver disease in dialysis patients, probably most often transmitted by blood transfusions but other routes of transmission could not be excluded.

Biomarkers of habitual fish intake in adipose tissue

The association between habitual fish and marine n-3 polyunsaturated fatty acid (PUFA) intake, and the fatty acid composition of subcutaneous fat was studied in 24 healthy young volunteers. Habitual dietary intakes were estimated from three 7-d weighted food records made at months 0, 5, and 8 of the 8-mo study period. The adipose tissue fatty acid composition of each individual was determined by gas chromatography as the mean of two gluteal biopsies, obtained in the first and the last month of the study. The daily consumption of fish and of marine n-3 PUFAs in absolute terms (g/d) was significantly associated with adipose tissue docosahexaenoic acid content (DHA; r = 0.55 and 0.58, respectively, P < 0.001), but not with eicosapentaenoic and docosapentaenoic acid contents. Our study indicates that the adipose tissue DHA content is the biomarker of choice for the assessment of long-term habitual dietary intakes of fish and marine n-3 PUFAs.

Daily monitoring of viral load measured as SARS-CoV-2 antigen and RNA in blood, IL-6, CRP and complement C3d predicts outcome in patients hospitalized with COVID-19

OBJECTIVES

We hypothesized that the amount of antigen produced in the body during a COVID-19 infection might differ between patients, and that maximum concentrations would predict the degree of both inflammation and outcome for patients.

METHODS

Eighty-four hospitalized and SARS-CoV-2 PCR swab-positive patients, were followed with blood sampling every day until discharge or death. A total of 444 serial EDTA plasma samples were analyzed for a range of biomarkers: SARS-CoV-2 nuclear antigen and RNA concentration, complement activation as well as several inflammatory markers, and KL-6 as a lung marker. The patients were divided into outcome groups depending on need of respiratory support and death/survival.

RESULTS

Circulating SARS-CoV-2 nuclear antigen levels were above the detection limit in blood in 65 out of 84 COVID-19 PCR swab-positive patients on day one of hospitalization, as was viral RNA in plasma in 30 out of 84. In all patients, complete antigen clearance was observed within 24 days. There were definite statistically significant differences between the groups depending on their biomarkers, showing that the concentrations of virus RNA and antigen were correlated to the inflammatory biomarker levels, respiratory treatment and death.

CONCLUSIONS

Viral antigen is cleared in parallel with the virus RNA levels. The levels of antigens and SARS-CoV-2 RNA in the blood correlates with the level of IL-6, inflammation, respiratory failure and death. We propose that the antigens levels together with RNA in blood can be used to predict the severity of disease, outcome, and the clearance of the virus from the body.

Patterns of anaphylaxis after diagnostic workup: A follow-up study of 226 patients with suspected anaphylaxis

BACKGROUND

Most published studies on anaphylaxis are retrospective or register based. Data on subsequent diagnostic workup are sparse. We aimed to characterize patients seen with suspected anaphylaxis at the emergency care setting (ECS), after subsequent diagnostic workup at our Allergy Center (AC).

METHODS

Prospective study including patients from the ECS, Odense University Hospital, during May 2013-April 2014. Possible anaphylaxis cases were daily identified based on a broad search profile including history and symptoms in patient records, diagnostic codes and pharmacological treatments. At the AC, all patients were evaluated according to international guidelines.

RESULTS

Among 226 patients with suspected anaphylaxis, the diagnosis was confirmed in 124 (54.9%) after diagnostic workup; 118 of the 124 fulfilled WAO/EAACI criteria of anaphylaxis at the ECS, while six were found among 46 patients with clinical suspicion but not fulfilling the WAO/EAACI criteria at the ECS. The estimated incidence rate of anaphylaxis was 26 cases per 100 000 person-years and the one-year period prevalence was 0.04%. The most common elicitor was drugs (41.1%) followed by venom (27.4%) and food (20.6%). In 13 patients (10.5%), no elicitor could be identified. Mastocytosis was diagnosed in 7.7% of adult patients and was significantly associated with severe anaphylaxis. Atopic diseases were significantly associated only with food-induced anaphylaxis. Cofactors were present in 58.1% and were significantly associated with severe anaphylaxis.

CONCLUSION

A broad search profile in the ECS and subsequent diagnostic workup is important for identification and classification of patients with anaphylaxis. Evaluation of comorbidities and cofactors is important.

Comparison of buffet and à la carte serving at worksite canteens on nutrient intake and fruit and vegetable consumption

OBJECTIVE

To evaluate the nutritional composition of worksite canteen lunches and to examine the impact of two meal serving systems on employee intake, i.e. buffet style with a fixed price for a varied number of dishes and à la carte style with a separate price for each item on the menu.

DESIGN

Laboratory technicians observed employees' food selection and collected identical dishes. Food items were weighed separately to calculate the content of fruit and vegetables. The content of protein, fat and ash of each dish was chemically analysed and the carbohydrate and energy content calculated.

SETTING

Fifteen randomly chosen worksite canteens in Denmark: eight canteens serving buffet style and seven canteens with an à la carte line.

SUBJECTS

one hundred and eighty randomly chosen employees having lunch at the worksite canteens.

RESULTS

The average percentage energy from fat was 37 +/- 12 among men and 33 +/- 12 among women. No association was found between the meal serving system and energy intake or macronutrient composition. Eating at canteens serving buffet style, on the other hand, was associated with an increased intake of fruit and vegetables, on average 76 g, and a lower energy density of the food for both genders.

CONCLUSION

The results highlight the possibilities of promoting healthy food choices in the catering sector and the need to identify models of healthy catering practice. Serving buffet style appears to be a promising strategy in order to increase fruit and vegetable consumption in food served away from home.

Use of anti-secretory medication: a population-based cohort study

BACKGROUND

Total use of anti-secretory medication (H2 blockers and proton pump inhibitors) is increasing rapidly, but knowledge of factors related to the increasing use is sparse.

AIM

To describe development in the use of anti-secretory medication between 1993 and 2002 at a population level.

METHODS

We extracted data on use of anti-secretory medication (H2-blockers and proton pump inhibitors) and ulcerogenic drugs, demographic data, and data on gastroscopy and endoscopically verified oesophagitis and peptic ulcer diagnoses, from three large population-based databases covering the County of Funen, Denmark 1990-2002 (population 470,000).

RESULTS

Between 1993 and 2002 incidence of first time users was stable at 16.7/1000 persons/year. Total amount of consumed anti-secretory medication increased from 10.5 DDD/1000 persons/day to 25.2 DDD/1000 persons/day. Ninety per cent of the increase was related to long-term use of anti-secretory medication (> or = 180 DDD/patient/year). In 1993 21% of the anti-secretory medication was used by patients with oesophagitis, this increased to 28% in 2002. The proportion of medication used by peptic ulcer patients decreased from 29% in 1993 to 19% in 2002.

CONCLUSIONS

Total use of anti-secretory medication increased as a result of more extensive long-term use, and most of the medication was used by patients without diagnosed peptic ulcer or oesophagitis.

Cardiovascular responses to brief static contractions in man with topical nervous blockade

1. We tested the hypothesis that afferent nerves from working muscles are important in determining the heart rate and blood pressure responses to brief maximal static exercise. 2. In twenty human subjects, the heart rate and arterial blood pressure responses to a brief maximal voluntary handgrip were studied before and after axillary nerve anaesthesia or to maximal one-leg knee extension before and after epidural anaesthesia at L3-L4. Maximal knee extension could not be accomplished without performing a 'Valsalva-like' manoeuvre, but during handgrip it was possible to avoid the use of muscles other than those directly involved in the contraction. Heart rate and blood pressure were also monitored during a Valsalva manoeuvre of similar duration to the maximal voluntary contractions (4 s). 3. During handgrip with normal breathing, axillary nerve anaesthesia reduced the heart rate response but had no effect on the blood pressure response. 4. During a Valsalva manoeuvre, blood pressure increased but heart rate remained stable as long as expiratory pressure was maintained. During one-leg knee extension, epidural anaesthesia reduced the blood pressure response; however, the reduction in blood pressure was probably due to a reduction in the simultaneously performed 'Valsalva-like' manoeuvre. 5. The results of this study suggest that afferent input from the working muscles is of importance for the heart rate responses to brief static muscle contractions. That such influence may be important for the blood pressure response remains unproven.

Do recommendations for institutional food service result in better food service? A study of compliance in Danish hospitals and nursing homes from 1995 to 2002-2003

BACKGROUND

Since 1995, significant efforts by authorities and researchers have been directed towards addressing the nutritional problems in Danish hospitals and nursing homes.

AIM

The purpose of this study was to investigate whether the increased focus on nutritional problems in patients and nursing home residents has resulted in measurable progress.

DESIGN

A questionnaire-based study was carried out among foodservice managers in Danish hospitals (n=96) and nursing homes (n=898) in 1995 and 2002/3 (n=90) and (n=682), respectively. The study used compliance with selected issues in the official Danish recommendations for institutional food service as an indicator for progress. The issues included: using nutrient calculated recipes/menus, offering menu choice options, using feedback routines on acceptability of menus, maintaining nutritional steering committees, employing food and nutrition contact persons, employing official recommendations and offering choice between three different menu energy levels.

RESULTS

Hospitals had a higher compliance compared to nursing homes. In 1995, this was the case for all questions asked and differences were statistically significant. Also in 2002/3, hospitals had a higher compliance, except in the case of established feedback routines. Differences were statistically significant. The results indicate that nutritional care is higher on the agenda in hospital, than in nursing homes. However, very little progress can be seen in compliance when results are analysed over the 8-year period. The only progress for nursing homes was that more homes had implemented feedback routines on acceptability of food service in 2002/3 than in 1995. The difference was statistically significant. For hospitals, however, no progress was found between 1995 and 2002/3.

CONCLUSION

The attempts to improve the nutritional status of hospital patients and nursing home residents seem to have failed. Still, the initiatives taken to improve the situation seem relevant. Especially the nursing homes might benefit from advantage of these experiences.

Bacteremia with Streptococcus pneumoniae: sepsis and other risk factors for 30-day mortality--a hospital-based cohort study

We conducted a hospital-based cohort study among adult patients with first-time Streptococcus pneumoniae bacteremia (SPB) from 2000 through 2008. Patients were identified in a population-based bacteremia database and followed up for mortality through the Danish Civil Registration System (CRS). The aim of the study was to determine the focal diagnosis of SPB, the severity of sepsis at presentation, demographics and comorbidity characteristics of the patients, and to determine the 30-day mortality rate and factors related to mortality. We identified 481 patients, of which 238 were males. The mean age of the patients was 65 years. The focal diagnosis of the SPB was pneumonia in 381 (79 %) patients, followed in frequency by meningitis in 33 (7 %) patients. Of the 481 patients, 390 (81 %) had community-acquired SPB. Of these, 23 (6 %) did not have sepsis, 132 (34 %) had sepsis, 224 (57 %) had severe sepsis, and 11 (3 %) were in septic shock. Overall, the 30-day mortality was 16 %. Mortality increased with the severity of sepsis. There was no association between the focal diagnosis of SPB or the number of diagnoses and mortality. Nosocomial infection, male sex, increasing age, and increasing comorbidity were all associated with an increased 30-day mortality rate.

CRAF R391W is a melanoma driver oncogene

Approximately 75% of melanomas have known driver oncogenic mutations in BRAF, NRAS, GNA11 or GNAQ, while the mutations providing constitutive oncogenic signaling in the remaining melanomas are not known. We established a melanoma cell line from a tumor with none of the common driver mutations. This cell line demonstrated a signaling profile similar to BRAF-mutants, but lacked sensitivity to the BRAF inhibitor vemurafenib. RNA-seq mutation data implicated CRAF R391W as the alternative driver mutation of this melanoma. CRAF R391W was homozygous and over expressed. These melanoma cells were highly sensitive to CRAF, but not BRAF knockdown. In reconstitution experiments, CRAF R391W, but not CRAF WT, transformed NIH3T3 cells in soft-agar colony formation assays, increased kinase activity in vitro, induced MAP kinase signaling and conferred vemurafenib resistance. MAP kinase inducing activity was dependent on CRAF dimerization. Thus, CRAF is a bona fide alternative oncogene for BRAF/NRAS/GNAQ/GNA11 wild type melanomas.

Are green caterers more likely to serve healthy meals than non-green caterers? Results from a quantitative study in Danish worksite catering

Objective

The present study aimed to investigate whether organic conversion in catering has positive effects on the nutritional quality of menus offered.

Design

The methodology was based on a self-administered questionnaire. The self-declared priority given to the use of organic foods was measured as the basis for assigning catering managers to one of two groups: ‘green’ or ‘non-green’ caterers. These groups were then compared with regard to the relative nutritional quality of the menu options offered to customers.

Setting

The study was carried out among randomly selected Danish worksite catering outlets.

Subjects

The subjects participating in the study comprised 526 Danish worksite catering managers.

Results

The results showed a strong correlation between caterers' ‘green-ness’ and the nutritional quality of the menu options offered. Green caters had more healthy options in their menus than non-green caters, which is likely to result in improved nutritional quality of the diets of end consumers. The reason for this may partly be the increased service training efforts that green caterers practise in order to be able to implement organic foods successfully. It may also be associated with the fact that the price premiums and availability of the organic products forces caterers to serve menus with higher amounts of root and non-green leafy vegetables, pulses and seasonal vegetables.

Conclusion

The present findings suggest that organic conversion of public canteens may be a good opportunity to promote healthier eating in public catering.

Ultrasound examination in jaundiced patients. Is computer-assisted preclassification helpful?

In this study we attempted to determine the diagnostic accuracy and reproducibility of ultrasonography (US) for jaundice and to see how US can best be combined with preliminary clinical-biochemical diagnoses to plan the invasive work-up. US proved reproducible in two diagnostic departments (127 agreements in 135 cases). But, since obstruction was underdiagnosed (15 double-false negatives), the predictive value of a negative result was only 0.83. By adding a term which represents the US conclusion, obstruction or not, to the Copenhagen pocket diagnostic chart score (based on the logistic model) we found that an obstructive conclusion increases the odds of obstruction by a factor of 25, and a non-obstructive conclusion decreases the odds by a factor of only 1.9. We conclude that the preliminary diagnosis is frequently sufficiently certain to be unalterable by US. This leaves only 40% of the jaundice cases in which US is necessary to plan invasive work-up. The US workload can even, it appears, be reduced to about 22% without appreciable penalty in terms of unrewarding invasive procedures. Using these strict indications, four US examinations seem to suffice to avoid one such error. Relying on either US or clinical-biochemical data alone is inferior to the combined strategy.

[What do people talk about in Danish hospital elevators?]

Hospital elevators make up a part of the public space of hospitals which is used by both employees, patients, and patients' relatives. We performed an observational study to ascertain the frequency of ethically problematic conversations between employees in the elevators of three Danish hospitals. We defined a conversation as problematic if it breached confidentiality or if it could raise doubts about the professional or ethical standard of the hospital or its employees. Based on this definition we found that problematic conversations occurred in 18 out of 201 elevator-trips where more than one member of the hospital staff was present in the elevator (9%, 95% confidence limits 5-14%). The most common types of problems were breaches of confidentiality (6 cases), complaints about stressful work (4 cases), and complaints about the organisation (3 cases).