Peritoneal papillary mesothelioma in situ: BAP1 mutation with indolent behavior for 15 years

Papillary mesothelioma in situ (PMIS) is a rare and enigmatic disease. Most instances manifest as lesions of the peritoneal serosa. The pathogenesis and behavior of peritoneal PMIS are still poorly understood, and separation from benign well differentiated peritoneal mesothelial tumors (WDPMT) may be challenging. We describe the 15-year long course of a PMIS in an adult male in which inactivating mutations of BAP1, encoding BRCA1 associated protein 1 (BAP1), were identified. Tumor samples were obtained on 2 occasions more than 8y apart. In both samples, the tumor cells were bland, with occasional focal infiltration into the stalks of larger papillary lesions. However, no invasion into subserosal adipose tissue was identified. In both samples the tumor cells did not express nuclear BAP1. Comprehensive genomic analysis of the initial tumor sample revealed a somatic inactivating mutation in BAP1 (predicted effect, Y223*) and a somatic variant of IRS2 (A701_V702insAA). An additional inactivating mutation in BAP1 (predicted effect, T69fs*5) was detected in the later sample. The patient did not receive any treatment and is still alive 15 years after initial presentation. Our experience supports the view that peritoneal PMIS may follow an indolent course for many years and prompts the question whether these tumors should uniformly be treated aggressively.

CHRONIC EFFECTS OF CADMIUM CHLORIDE ON RAT EMBRYOGENESIS

The purpose of this study was to analyze the effects of cadmium toxicity on rat embryogenesis when exposed to other heavy metal citrates. Despite the variety of scientific publications discussing the influence of cadmium on mammalian postnatal development, the effect of this metal on embryogenesis has not yet been sufficiently studied. In this experimental study, cadmium chloride was administered to experimental pregnant female Wistar rats at a daily dose of 1.0 mg/kg. Rats were allocated at random into groups receiving either cadmium chloride alone or additional zinc citrate, cerium citrate, or nanocomposite (based on iodine, sulfur, and selenium citrate). The control group received distilled water at an equivalent volume. In each group, operational intervention occurred at the 13th and 20th day of gestation to assess numbers of live fetuses, corpora lutea, pre-implantation losses, post-implantation losses, and total implantation losses. When cadmium chloride alone was administered, a pronounced embryotoxic effect was observed, manifested as a significant decrease in the number of live fetuses. Experimental groups which received cadmium chloride with zinc citrate, cerium citrate, or nanocomposite had an increased number of live fetuses and corpora lutea, as well as a decreased number of implantation losses, compared to the group which only received cadmium chloride. Each combination of cerium, zinc, and selenium nanocomposite citrates demonstrated a compensatory effect on all measures of embryogenesis impacted by cadmium embryotoxicity. Thus, administration of the citrates of cerium, zinc, and selenium nanocomposite reduces cadmium embryotoxicity and its accumulation in the body.

Significant liver fibrosis is a predictor of poor health-related quality of life in people living with HIV

PURPOSE

Liver-related comorbidities can impair the health-related quality of life (HRQL) in people living with human immunodeficiency virus (HIV) (PLWH). However, the role of hepatic steatosis and significant fibrosis in PLWH remains incompletely characterized. Therefore, the aim of this study was to explore the association of hepatic steatosis and significant fibrosis on the HRQL using the medical outcomes study HIV health survey (MOS-HIV) in PLWH.

METHODS

A total of 222 PLWH were included in the final analysis of this cohort study. Metabolic comorbidities, socioeconomic factors, and HIV-related parameters were assessed. Hepatic steatosis and fibrosis were measured using vibration-controlled transient elastography (VCTE). The MOS-HIV survey, containing two summary scores (physical health summary (PHS) and mental health summary (MHS)) and ten domains, was used to assess the HRQL. Clinical predictors were identified using multivariable linear regression models.

RESULTS

The majority of this cohort was male, and the median age was 52 years, with a high prevalence of hepatic steatosis (n = 81, 36.5%). Significant fibrosis was present in 7.7% (n = 17). The mean PHS and MHS scores were 52.7 ± 9.5 and 51.4 ± 10.5, respectively. The lowest scores were in the general health perception (GHP) and energy/fatigue (EF) domains. A high BMI and waist circumference were associated with a poor PHS score. Lower education, unemployment, arterial hypertension, and significant fibrosis remained independent predictors of an impaired HRQL.

CONCLUSION

Metabolic comorbidities, significant fibrosis, and a lower socioeconomic status may negatively affect the HRQL in PLWH. Considering the negative impact of significant fibrosis on the outcome, counseling and preventive measures according to current guidelines are recommended in this subgroup of PLWH.

Prevalence and risk factors of nonalcoholic steatohepatitis with significant fibrosis in people with HIV

OBJECTIVE

Metabolic risk factors and nonalcoholic fatty liver disease (NAFLD) in people with HIV (PWH) have been increasing. Patients exhibiting the inflammatory subtype nonalcoholic steatohepatitis (NASH) are at increased risk of liver-related complications. Therefore, the aim was to investigate the prevalence of NASH with significant fibrosis in PWH using noninvasive tests (NITs).

DESIGN

In this prospectively enrolling cohort study, 282 PWH were explored for hepatic steatosis, fibrosis and steatohepatitis using vibration-controlled transient elastography (VCTE) and the Fibroscan-AST (FAST) score.

METHODS

On the basis of controlled attenuation parameter (CAP; dB/m) and liver stiffness measurement (LSM; kPa), patients were categorized according to the presence of steatosis (≥275 dB/m) and significant fibrosis (≥8.2 kPa). The FAST score was calculated according to established cut-offs.

RESULTS

The prevalence of hepatic steatosis in this cohort was 35.5% ( n  = 100) with 75 (75%) of these patients fulfilling the criteria of NAFLD. The prevalence of significant fibrosis (≥ F2) was 6.7% ( n  = 19). The FAST score identified a total of 32 (12.3%) patients with a cut-off greater than 0.35, of whom 28 (87.5%) PWH qualified as NASH. On multivariable analysis, waist circumference was a predictor of hepatic steatosis and type 2 diabetes was a predictor of significant fibrosis. Type 2 diabetes and ALT remained independent predictors of a FAST score greater than 0.35.

CONCLUSION

NASH with significant fibrosis is highly prevalent among PWH. The FAST score may be helpful to identify patients at risk for significant liver disease.

Effect of hepatic steatosis and associated metabolic comorbidities on health-related quality of life in people living with HIV

Hepatic steatosis (HS) related to nonalcoholic fatty liver disease (NAFLD) is increasing globally. In people living with human immunodeficiency virus (PLWH) risk factors of HS are increased. The impact of HS on outcomes and in particular health-related quality of life (HRQL) in PLWH remains unknown. The aim of this cross-sectional cohort study (FLASH, Prevalence of Advanced Fibrosis in Patients Living With HIV) was to determine the contribution of HS on HRQL in PLWH and to identify confounders on HRQL. A total of 245 PLWH were prospectively enrolled. HS was assessed using vibration-controlled transient elastography and defined as a controlled attenuation parameter (CAP) of ≥ 275 dB/m. The analysis was performed between CAP < 275 and ≥ 275 dB/m. The generic European Quality-of-Life 5-Dimension 5-Level questionnaire was used to determine differences in the HRQL. Univariable and multivariable linear regression models were applied to identify predictors with impaired HRQL in both groups. In this cohort, 65% (n = 160) presented without and 35% (n = 85) with HS, of whom most had NAFLD (n = 65, 76.5%). The HRQL (UI-value) was significantly lower in PLWH and steatosis (0.86 ± 0.18) in comparison with no steatosis (0.92 ± 0.13). Unemployment (p = 0.025) and waist circumference (p = 0.017) remained independent predictors of a poor HRQL in the steatosis subgroup. In turn, age (p = 0.045), female sex (p = 0.030), body mass index (p = 0.010), and arterial hypertension (p = 0.025) were independent predictors of a low HRQL in the subgroup without steatosis. Conclusion: HS and metabolic comorbidities negatively affect the HRQL. Addressing these factors may improve patient-reported and liver-related outcomes in PLWH.

Immune Response in Heart Transplant Patients Following COVID-19 Vaccination

Purpose

Previous studies have described poor outcomes in heart transplant patients who develop COVID-19 infection. Therefore, we sought to characterize a single center's experience with heart transplant patient outcomes during the COVID-19 pandemic and the recent role of vaccination in mitigating the risk of mortality.

Methods

From a single center, we identified all orthotopic heart transplant patients alive at the beginning of the COVID-19 pandemic in March 2020. All patients were followed from the start of the pandemic until their most recent follow up or death. Baseline comorbidities and immediate outcomes data were obtained from the Society for Thoracic Surgery (STS) Adult Cardiac Surgery Database (ACSD). Multiple logistic regression analyzed the association between vaccination status, baseline covariates, and other standard STS outcome measures. Non-parametric tests were used to compare different subgroups.

Results

We included 153 patients, of which 20.9% developed COVID-19 infection (32/153) with 40.6% (13/32) requiring hospitalization and 15.6% of those patients (5/32) dying as a direct result of COVID-19 pneumonia. Kaplan-Meier survival analysis revealed that unvaccinated patients had a significantly higher rate of all-cause mortality as compared to those patients that were fully vaccinated despite similar baseline characteristics (p < 0.001). Patients with previous COVID-19 infection in addition to vaccination had significantly higher IgG titers as compared to those only vaccinated (6568.50 AU/mL vs. 58.05 AU/mL, p = 0.002).

Conclusion

Immunization against COVID-19 is associated with a significant reduction in the mortality of heart transplant patients. IgG titers were variable among heart transplant patients who received the vaccine with the highest titers seen in those patients with a personal history of COVID-19. The implications of IgG levels are still unknown.

Validity and reliability of the Norwegian version of the eHealth Literacy Scale (eHEALS) among patients after percutaneous coronary intervention

Funding Acknowledgements

The Western Norway Health Authority.

OnBehalf

The CONCARD-PCI Investigators

Background

In recent years an internet-based technology has become an important source for providing health information to patients after an acute cardiac event. Therefore, consideration of patients’ perceived eHealth literacy skills, is crucial for improving patient-centred health information after percutaneous coronary intervention (PCI).

Purpose

The aim of this study was to translate and adapt the eHealth literacy Scale (eHEALS) to conditions in Norway, and to determine the psychometric properties of the eHEALS in self-report format administered to patients after PCI.

Methods

The original English version of the eHEALS was translated into Norwegian, following a cross-cultural adaptation process. Further, we set out to determine the reliability (internal consistency, test-retest) and construct validity (structural validity, hypotheses testing and cross-cultural validity). Internal consistency was calculated using Cronbach alpha. Intra-class correlation (ICC) was used to assess test-retest reliability. A confirmatory factor analysis (CFA) was performed for a priori hypotheses 1-, 2- and 3-factor model. Demographic information, health-related internet use, health literacy and health status were collected to correlate with eHEALS scores.

Results

For the validation, 1695 patients were included after PCI. Mean age was 66 years. Most of the patients were male (78%). Cronbach’s alpha for the eHEALS was &gt;0.999. The corresponding Cronbach’s alpha for the 2-week retest was &gt;0.937. The ICC for eHEALS was 0.605 (95% CI 0.419-0.743, P &lt; 0.001). CFA showed a modest model fit of the 1- and 2-factor model. After modifications in the 3-factor model, all the goodness-of-fit indices indicated a good fit. A weak correlation with age (r=-0.206) was found. Employed and higher educated patients scored higher on the eHEALS: There was a higher eHEALS score for the patients with higher education level compared with those with lower education level (mean difference between 2.24 (P = 0.002) and 4.61 (P &lt; 0.001)), and for the patients who were employed compared to those who were retired (mean difference 2.31, P &lt; 0.001). The eHEALS score was higher among the patients who reported to use the internet to find health information (95% CI -21.40, -17.21 (P &lt; 0.001)).  There was a moderate correlation with perceived usefulness (r = 0.587) and importance (r = 0.574) of using the internet for health information. There was a moderate correlation with the health literacy dimensions for appraisal of health information (r= 0.380) and ability to find good health information (r = 0.561). 

Conclusions

The study provides additional information on the psychometric properties of the eHEALS for patients after PCI, suggesting a multidimensional construct rather than unidimensional. The high internal consistency indicated a redundancy of items. Therefore, further validation studies of the eHEALS is required.

P2714Time-dependent myocardial necrosis in patients suffering from ST-elevation myocardial infarction without angiographic collateral flow visualized by cardiac magnetic resonance imaging

Background

Acute complete occlusion of a coronary artery results in progressive ischemia, moving from the endocardium to the epicardium (“wavefront”). Dependent on time-to-reperfusion and collateral flow, myocardial infarction (MI) will manifest, with transmural MI portending poor prognosis. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging can detect MI with high diagnostic accuracy. Primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy in patients with STEMI <12 hours of symptom onset.

Purpose

We sought to visualize time-dependent necrosis in a ST-segment elevation myocardial infarction (STEMI) population by LGE-CMR.

Methods

STEMI patients with: single-vessel disease, complete occlusion with Thrombolysis in Myocardial Infarction (TIMI) score 0, absence of collateral flow (Rentrop score 0) and symptom onset <12 hours were consecutively enrolled. By LGE-CMR, area at risk (AAR) and infarct size (IS), myocardial salvage index (MSI), transmurality index, and transmurality grade (0–50%, 51–75%, 76–100%) were determined.

Results

164 patients (54±11 years, 80% male) were included. Receiver-operating-characteristic (ROC)-curve (area under the curve [AUC] = 0.81) indicating transmural necrosis revealed the best diagnostic cut-off for a symptom-to-balloon time of 121 minutes, i.e. patients with >121 minutes demonstrated increased IS, transmurality index, transmurality grade (all p-values <0.01), and decreased MSI (p<0.001) vs. patients with symptom-to-balloon times ≤121 minutes.

Conclusions

In myocardial infarction with no residual antegrade, and no collateral flow, immediate reperfusion is vital. A symptom-to-balloon time of >121 minutes causes a high grade of transmural necrosis. In the present, pure STEMI population, time to reperfusion to salvage myocardium was less than suggested by current guidelines.

A systematic review of quality of life research in medicine and health sciences

Purpose

Quality of life (QOL) is an important concept in the field of health and medicine. QOL is a complex concept that is interpreted and defined differently within and between disciplines, including the fields of health and medicine. The aims of this study were to systematically review the literature on QOL in medicine and health research and to describe the country of origin, target groups, instruments, design, and conceptual issues.

Methods

A systematic review was conducted to identify research studies on QOL and health-related quality of life (HRQOL). The databases Scopus, which includes Embase and MEDLINE, CINAHL, and PsycINFO were searched for articles published during one random week in November 2016. The ten predefined criteria of Gill and Feinstein were used to evaluate the conceptual and methodological rigor.

Results

QOL research is international and involves a variety of target groups, research designs, and QOL measures. According to the criteria of Gill and Feinstein, the results show that only 13% provided a definition of QOL, 6% distinguished QOL from HRQOL. The most frequently fulfilled criteria were: (i) stating the domains of QOL to be measured; (ii) giving a reason for choosing the instruments used; and (iii) aggregating the results from multiple items.

Conclusion

QOL is an important endpoint in medical and health research, and QOL research involves a variety of patient groups and different research designs. Based on the current evaluation of the methodological and conceptual clarity of QOL research, we conclude that the majority QOL studies in health and medicine have conceptual and methodological challenges.

Electronic supplementary material

The online version of this article (doi:10.1007/s11136-019-02214-9) contains supplementary material, which is available to authorized users.

Functional expression of a heterologous nickel-dependent, ATP-independent urease in Saccharomyces cerevisiae

In microbial processes for production of proteins, biomass and nitrogen-containing commodity chemicals, ATP requirements for nitrogen assimilation affect product yields on the energy producing substrate. In Saccharomyces cerevisiae, a current host for heterologous protein production and potential platform for production of nitrogen-containing chemicals, uptake and assimilation of ammonium requires 1 ATP per incorporated NH3. Urea assimilation by this yeast is more energy efficient but still requires 0.5 ATP per NH3 produced. To decrease ATP costs for nitrogen assimilation, the S. cerevisiae gene encoding ATP-dependent urease (DUR1,2) was replaced by a Schizosaccharomyces pombe gene encoding ATP-independent urease (ure2), along with its accessory genes ureD, ureF and ureG. Since S. pombe ure2 is a Ni(2+)-dependent enzyme and Saccharomyces cerevisiae does not express native Ni(2+)-dependent enzymes, the S. pombe high-affinity nickel-transporter gene (nic1) was also expressed. Expression of the S. pombe genes into dur1,2Δ S. cerevisiae yielded an in vitro ATP-independent urease activity of 0.44±0.01 µmol min(-1) mg protein(-1) and restored growth on urea as sole nitrogen source. Functional expression of the Nic1 transporter was essential for growth on urea at low Ni(2+) concentrations. The maximum specific growth rates of the engineered strain on urea and ammonium were lower than those of a DUR1,2 reference strain. In glucose-limited chemostat cultures with urea as nitrogen source, the engineered strain exhibited an increased release of ammonia and reduced nitrogen content of the biomass. Our results indicate a new strategy for improving yeast-based production of nitrogen-containing chemicals and demonstrate that Ni(2+)-dependent enzymes can be functionally expressed in S. cerevisiae.

A new variable for SRS plan quality evaluation based on normal tissue sparing: the effect of prescription isodose levels

OBJECTIVE

A new dosimetric variable, dose-dropping speed (DDS), was proposed and used to evaluate normal tissue sparing among stereotactic radiosurgery (SRS) plans with different prescription isodose lines.

METHODS

40 plans were generated for 8 intracranial SRS cases, prescribing to isodose levels (IDLs) ranging from 50% to 90% in 10% increments. Whilst maintaining similar coverage and conformity, plans at different IDLs were evaluated in terms of normal tissue sparing using the proposed DDS. The DDS was defined as the greater decay coefficient in a double exponential decay fit of the dose drop-off outside the planning target volume (PTV), which models the steep portion of the drop-off. Provided that the prescription dose covers the whole PTV, a greater DDS indicates better normal tissue sparing.

RESULTS

Among all plans, the DDS was found to be the lowest for the prescription at 90% IDL and the highest for the prescription at 60% or 70%. The beam profile slope change in the penumbra and its field size dependence were explored and given as the physical basis of the findings.

CONCLUSION

A variable was proposed for SRS plan quality evaluation. Using this measure, prescriptions at 60% and 70% IDLs were found to provide best normal tissue sparing.

ADVANCES IN KNOWLEDGE

A new variable was proposed based on which normal tissue sparing was quantitatively evaluated, comparing different prescription IDLs in SRS.

Multi-centre calibration of an adaptive thresholding method for PET-based delineation of tumour volumes in radiotherapy planning of lung cancer

PURPOSE

To evaluate the calibration of an adaptive thresholding algorithm (contrast-oriented algorithm) for FDG PET-based delineation of tumour volumes in eleven centres with respect to scanner types and image data processing by phantom measurements.

METHODS

A cylindrical phantom with spheres of different diameters was filled with FDG realizing different signal-to-background ratios and scanned using 5 Siemens Biograph PET/CT scanners, 5 Philips Gemini PET/CT scanners, and one Siemens ECAT-ART PET scanner. All scans were analysed by the contrast-oriented algorithm implemented in two different software packages. For each site, the threshold SUVs of all spheres best matching the known sphere volumes were determined. Calibration parameters a and b were calculated for each combination of scanner and image-analysis software package. In addition, "scanner-type-specific" calibration curves were determined from all values obtained for each combination of scanner type and software package. Both kinds of calibration curves were used for volume delineation of the spheres.

RESULTS

Only minor differences in calibration parameters were observed for scanners of the same type (Δa ≤4%, Δb ≤14%) provided that identical imaging protocols were used whereas significant differences were found comparing calibration parameters of the ART scanner with those of scanners of different type (Δa ≤60%, Δb ≤54%). After calibration, for all scanners investigated the calculated SUV thresholds for auto-contouring did not differ significantly (all p>0.58). The resulting sphere volumes deviated by less than -7% to +8% from the true values.

CONCLUSION

After multi-centre calibration the use of the contrast-oriented algorithm for FDG PET-based delineation of tumour volumes in the different centres using different scanner types and specific imaging protocols is feasible.

Metabolic adaptation of MDCK cells to different growth conditions: effects on catalytic activities of central metabolic enzymes

Lactate and ammonia are the most important waste products of central carbon metabolism in mammalian cell cultures. In particular during batch and fed-batch cultivations these toxic by-products are excreted into the medium in large amounts, and not only affect cell viability and productivity but often also prevent growth to high cell densities. The most promising approach to overcome such a metabolic imbalance is the replacement of one or several components in the culture medium. It has been previously shown that pyruvate can be substituted for glutamine in cultures of adherent Madin-Darby canine kidney (MDCK) cells. As a consequence, the cells not only released no ammonia but glucose consumption and lactate production were also reduced significantly. In this work, the impact of media changes on glucose and glutamine metabolism was further elucidated by using a high-throughput platform for enzyme activity measurements of mammalian cells. Adherent MDCK cells were grown to stationary and exponential phase in six-well plates in serum-containing GMEM supplemented with glutamine or pyruvate. A total number of 28 key metabolic enzyme activities of cell extracts were analyzed. The overall activity of the pentose phosphate pathway was up-regulated during exponential cell growth in pyruvate-containing medium suggesting that more glucose-6-phosphate was channeled into the oxidative branch. Furthermore, the anaplerotic enzymes pyruvate carboxylase and pyruvate dehydrogenase showed higher cell specific activities with pyruvate. An increase in cell specific activity was also found for NAD(+)-dependent isocitrate dehydrogenase, glutamate dehydrogenase, and glutamine synthetase in MDCK cells grown with pyruvate. It can be assumed that the increase in enzyme activities was required to compensate for the energy demand and to replenish the glutamine pool. On the other hand, the activities of glutaminolytic enzymes (e.g., alanine and aspartate transaminase) were decreased in cells grown with pyruvate, which seems to be related to a decreased glutamine metabolism.

Magnetocaloric effect and improved relative cooling power in (La(0.7)Sr(0.3)MnO(3)/SrRuO(3)) superlattices

Magnetic properties of a series of (La(0.7)Sr(0.3)MnO(3)/SrRuO(3)) superlattices, where the SrRuO(3) layer thickness is varying, are examined. A room-temperature magnetocaloric effect is obtained owing to the finite size effect which reduces the T(C) of La(0.7)Sr(0.3)MnO(3) layers. While the working temperature ranges are enlarged, - ΔS(M)(max) values remain similar to the values in polycrystalline La(0.7)Sr(0.3)MnO(3). Consequently, the relative cooling powers are significantly improved, the microscopic mechanism of which is related to the effect of the interfaces at La(0.7)Sr(0.3)MnO(3)/SrRuO(3) and higher nanostructural disorder. This study indicates that artificial oxide superlattices/multilayers might provide an alternative pathway in searching for efficient room-temperature magnetic refrigerator for (nano) micro-scale systems.

Expression, purification, and characterization of a His6-tagged glycerokinase from Pichia farinosa for enzymatic cycling assays in mammalian cells

The GUT1 gene of the halotolerant yeast Pichia farinosa, encoding glycerokinase (EC 2.7.1.30), was expressed in Pichia pastoris. A purification factor of approximately 61-fold was achieved by a combination of nickel affinity and anion exchange chromatography. The specific activity of the final preparation was 201.6 units per mg protein with a yield of about 21%. A nearly homogeneous enzyme preparation was confirmed by SDS-polyacrylamide gels and mass spectrometry analysis. Glycerol stabilized the purified enzyme for long-term storage at -80°C. The pH and temperature optima were in the range of 6.5-7.0 and 45-50°C, respectively. ATP was the most effective phosphoryl group donor tested. Additionally, the enzyme phosphorylated glycerol also with ITP, UTP, GTP and CTP. The K(m) values of the enzyme for ATP and ITP were 0.428 and 0.845 mM, respectively. The kinetic properties of the enzyme with respect to UTP, GTP, and CTP suggested that glycerokinase exhibited negative cooperativity as double reciprocal plots showed a biphasic response to increasing nucleoside triphosphate concentrations. The application as a coupling enzyme in the determination of pyruvate kinase activity in cell extracts of Madin-Darby canine kidney cells showed good reproducibility when compared with a commercially available preparation of bacterial glycerokinase.

Evaluation of the effect of TRU-016, an anti-CD37 directed SMIP in combination with other therapeutic drugs in models of non-Hodgkin's lymphoma

8571

Background: TRU-016, a single chain anti-CD37 Fc fusion molecule has been shown to display pro-apoptotic and Fc-dependent cellular cytotoxicity activities against primary CLL cells and NHL cell lines. The pro-apoptotic signal generated by TRU-016 binding to CD37 on CLL cells has been shown to be caspase-independent and distinct from the signal generated by many other therapeutics including rituximab. We have tested drug combinations using the mantle cell lymphoma line Rec-1 and diffuse large B-cell lymphoma line SU-DHL-6 in vitro and extended these results to in vivo settings using the follicular lymphoma cell line DOHH2 treated with the combination of TRU-016 and bendamustine. Methods: To determine TRU-016 interactions with the established therapeutics rituximab, doxorubicin, rapamycin, and bendamustine, drugs were tested alone or in combination with TRU-016 and the anti-proliferative effects on cell lines measured after 96 hours. Combination index analysis was performed for drug combinations over the 20–90% effect levels using the Calcusyn software package. To determine if in vitro synergy could be recapitulated in vivo, SCID mice were implanted with DOHH2 cells and therapeutic treatment was initiated when tumor volumes reached 200 mm3. Treatments consisted of TRU-016, bendamustine, or the combination of TRU-016 and bendamustine. Results: Combination index analyses determined that TRU-016 is synergistic with rituximab, bendamustine, or rapamycin and additive with doxorubicin in NHL models. In vivo results show that treatment with the combination of TRU-016 and bendamustine resulted in increased efficacy compared to the efficacy attained with the individual drugs. This demonstrates that the in vitro synergy results were extendable to a more complex in vivo disease model. Conclusions: TRU-016 in combination with rituximab, rapamycin, or bendamustine increases cell killing of NHL cells. Furthermore, the combination of TRU-016 and bendamustine displayed greater in vivo anti-tumor activity than either agent alone against a follicular lymphoma tumor model.

[Table: see text]

Long-term results after fluoroscopy-guided closure of patent foramen ovale for secondary prevention of paradoxical embolism

OBJECTIVES

To carry out long-term follow-up after percutaneous closure of patent foramen ovale (PFO) in patients with cryptogenic stroke.

DESIGN

Prospective cohort study.

SETTING

Single tertiary care centre.

PARTICIPANTS

525 consecutive patients (mean (SD) age 51 (12) years; 56% male).

INTERVENTIONS

Percutaneous PFO closure without intraprocedural echocardiography.

MAIN OUTCOME MEASURES

Freedom from recurrent embolic events.

RESULTS

A mean (SD) of 1.7 (1.0) clinically apparent embolic events occurred for each patient, and 186 patients (35%) had >1 event. An atrial septal aneurysm was associated with the PFO in 161 patients (31%). All patients were followed up prospectively for up to 11 years. The implantation procedure failed in two patients (0.4%). There were 13 procedural complications (2.5%) without any long-term sequelae. Contrast transoesophageal echocardiography at 6 months showed complete closure in 86% of patients, and a minimal, moderate or large residual shunt in 9%, 3% and 2%, respectively. Patients with small occluders (<30 mm; n = 429) had fewer residual shunts (small 11% vs large 27%; p<0.001). During a mean (SD) follow-up of 2.9 (2.2) years (median 2.3 years; total 1534 patient-years), six ischaemic strokes, nine transient ischaemic attacks (TIAs) and two peripheral emboli occurred. Freedom from recurrent stroke, TIA, or peripheral embolism was 98% at 1 year, 97% at 2 years and 96% at 5 and 10 years, respectively. A residual shunt (hazard ratio = 3.4; 95% CI 1.3 to 9.2) was a risk factor for recurrence.

CONCLUSIONS

This study attests to the long-term safety and efficacy of percutaneous PFO closure guided by fluoroscopy only for secondary prevention of paradoxical embolism in a large cohort of consecutive patients.

Depletion of Normal and Malignant B cells with a CD37-specific SMIP molecule

3063

Background: CD37 is a member of the tetraspanin family expressed at high levels by normal mature B cells and by most B cell malignancies. Previously, an antibody to CD37 has been labeled with 131I and tested in clinical trials for therapy of NHL. Treatment with 131I-MB-1, resulted in durable tumor remissions in patients lasting from 4 to 11 months (Press OW, Eary JF, Badger CC, et al. Treatment of refractory non-Hodgkin’s lymphoma with radiolabeled MB-1 (anti-CD37) antibody. J Clin Oncol. 1989;7:1027–1038). Here we assess the functional properties and therapeutic potential of a small modular immunopharmaceutical (SMIP) targeting CD37. Methods: Growth arrest and apoptosis of B lymphoma cell lines was assessed. ADCC activity was evaluated using BJAB targets and human peripheral blood mononuclear cells (PBMC) effectors. Drug-drug interactions were assessed by the Combination Index method. In vivo studies were performed utilizing established human B cell tumor xenografts in nude mice. Results: A CD37-directed SMIP drug candidate mediated growth arrest, apoptosis and ADCC, but not CDC, towards B lymphoma cell lines. The protein showed significant anti-tumor activity in a mouse xenograft model, and selectively depleted normal human B cells in short term cultures of PBMC. When combined with rituximab, the molecule increased apoptosis, C1q binding, and C’ dependent target cell death in vitro, and increased anti-tumor activity in vivo in a xenograft model. Conclusions: In vitro and in vivo characterization of the CD37-targeted SMIP drug suggest a potent capacity to eliminate target cells through combined effects of direct target cell signaling and effector cell recruitment. CD37-mediated growth was synergistic with standard chemotherapies in vitro and showed additive in vivo activity with CD20-targeted therapy. On the basis of these data CD37-directed SMIP therapy is being developed for clinical evaluation against B cell malignancies.

No significant financial relationships to disclose.

Fluorescence quencher improves scansystemtm for rapid bacterial detection

BACKGROUND AND OBJECTIVES

The optimized scansystem could detect contaminated platelet products within 24 h. However, the system's sensitivity was reduced by a high fluorescence background even in sterile samples, which led to the necessity of a well-trained staff for confirmation of microscope results.

MATERIALS AND METHODS

A new protocol of the optimized scansystem with the addition of a fluorescence quencher was evaluated. Pool platelet concentrates contaminated with five transfusion-relevant bacterial strains were tested in a blind study.

RESULTS

In conjunction with new analysis software, the new quenching dye was able to reduce significantly unspecific background fluorescence. Sensitivity was best for Bacillus cereus and Escherichia coli (3 CFU/ml).

DISCUSSION

The application of a fluorescence quencher enables automated discrimination of positive and negative test results in 60% of all analysed samples.