IL-10 dampens antitumor immunity and promotes liver metastasis via PD-L1 induction

BACKGROUND & AIMS

The liver is one of the organs most commonly affected by metastasis. The presence of liver metastases has been reported to be responsible for an immunosuppressive microenvironment and diminished immunotherapy efficacy. Herein, we aimed to investigate the role of IL-10 in liver metastasis and to determine how its modulation could affect the efficacy of immunotherapy in vivo.

METHODS

To induce spontaneous or forced liver metastasis in mice, murine cancer cells (MC38) or colon tumor organoids were injected into the cecum or the spleen, respectively. Mice with complete and cell type-specific deletion of IL-10 and IL-10 receptor alpha were used to identify the source and the target of IL-10 during metastasis formation. Programmed death ligand 1 (PD-L1)-deficient mice were used to test the role of this checkpoint. Flow cytometry was applied to characterize the regulation of PD-L1 by IL-10.

RESULTS

We found that Il10-deficient mice and mice treated with IL-10 receptor alpha antibodies were protected against liver metastasis formation. Furthermore, by using IL-10 reporter mice, we demonstrated that Foxp3+ regulatory T cells (Tregs) were the major cellular source of IL-10 in liver metastatic sites. Accordingly, deletion of IL-10 in Tregs, but not in myeloid cells, led to reduced liver metastasis. Mechanistically, IL-10 acted on Tregs in an autocrine manner, thereby further amplifying IL-10 production. Furthermore, IL-10 acted on myeloid cells, i.e. monocytes, and induced the upregulation of the immune checkpoint protein PD-L1. Finally, the PD-L1/PD-1 axis attenuated CD8-dependent cytotoxicity against metastatic lesions.

CONCLUSIONS

Treg-derived IL-10 upregulates PD-L1 expression in monocytes, which in turn reduces CD8+ T-cell infiltration and related antitumor immunity in the context of colorectal cancer-derived liver metastases. These findings provide the basis for future monitoring and targeting of IL-10 in colorectal cancer-derived liver metastases.

IMPACT AND IMPLICATIONS

Liver metastasis diminishes the effectiveness of immunotherapy and increases the mortality rate in patients with colorectal cancer. We investigated the role of IL-10 in liver metastasis formation and assessed its impact on the effectiveness of immunotherapy. Our data show that IL-10 is a pro-metastatic factor involved in liver metastasis formation and that it acts as a regulator of PD-L1. This provides the basis for future monitoring and targeting of IL-10 in colorectal cancer-derived liver metastasis.

Genotyping of Helicobacter pylori CagA/CagE strains in gastric mucosa and its association with gastric illness

The aim of this work was associate the presence of the virulence factors of Helicobacter pylori, cagA/cagE, with gastric illness. We found evidence that indicate the contribution of these genotypes with the severity of gastric lesions in patients infected, principally in histological subtypes as atrophic gastritis, and metaplasia.

A novel unconventional T cell population enriched in Crohn's disease

OBJECTIVE

One of the current hypotheses to explain the proinflammatory immune response in IBD is a dysregulated T cell reaction to yet unknown intestinal antigens. As such, it may be possible to identify disease-associated T cell clonotypes by analysing the peripheral and intestinal T-cell receptor (TCR) repertoire of patients with IBD and controls.

DESIGN

We performed bulk TCR repertoire profiling of both the TCR alpha and beta chains using high-throughput sequencing in peripheral blood samples of a total of 244 patients with IBD and healthy controls as well as from matched blood and intestinal tissue of 59 patients with IBD and disease controls. We further characterised specific T cell clonotypes via single-cell RNAseq.

RESULTS

We identified a group of clonotypes, characterised by semi-invariant TCR alpha chains, to be significantly enriched in the blood of patients with Crohn's disease (CD) and particularly expanded in the CD8⁺ T cell population. Single-cell RNAseq data showed an innate-like phenotype of these cells, with a comparable gene expression to unconventional T cells such as mucosal associated invariant T and natural killer T (NKT) cells, but with distinct TCRs.

CONCLUSIONS

We identified and characterised a subpopulation of unconventional Crohn-associated invariant T (CAIT) cells. Multiple evidence suggests these cells to be part of the NKT type II population. The potential implications of this population for CD or a subset thereof remain to be elucidated, and the immunophenotype and antigen reactivity of CAIT cells need further investigations in future studies.

Microbial regulation of hexokinase 2 links mitochondrial metabolism and cell death in colitis

Hexokinases (HK) catalyze the first step of glycolysis limiting its pace. HK2 is highly expressed in gut epithelium, contributes to immune responses, and is upregulated during inflammation. We examined the microbial regulation of HK2 and its impact on inflammation using mice lacking HK2 in intestinal epithelial cells (Hk2ΔIEC). Hk2ΔIEC mice were less susceptible to acute colitis. Analyzing the epithelial transcriptome from Hk2ΔIEC mice during colitis and using HK2-deficient intestinal organoids and Caco-2 cells revealed reduced mitochondrial respiration and epithelial cell death in the absence of HK2. The microbiota strongly regulated HK2 expression and activity. The microbially derived short-chain fatty acid (SCFA) butyrate repressed HK2 expression via histone deacetylase 8 (HDAC8) and reduced mitochondrial respiration in wild-type but not in HK2-deficient Caco-2 cells. Butyrate supplementation protected wild-type but not Hk2ΔIEC mice from colitis. Our findings define a mechanism how butyrate promotes intestinal homeostasis and suggest targeted HK2-inhibition as therapeutic avenue for inflammation.

Association of clinical factors and recent anticancer therapy with COVID-19 severity among patients with cancer: a report from the COVID-19 and Cancer Consortium

BACKGROUND

Patients with cancer may be at high risk of adverse outcomes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We analyzed a cohort of patients with cancer and coronavirus 2019 (COVID-19) reported to the COVID-19 and Cancer Consortium (CCC19) to identify prognostic clinical factors, including laboratory measurements and anticancer therapies.

PATIENTS AND METHODS

Patients with active or historical cancer and a laboratory-confirmed SARS-CoV-2 diagnosis recorded between 17 March and 18 November 2020 were included. The primary outcome was COVID-19 severity measured on an ordinal scale (uncomplicated, hospitalized, admitted to intensive care unit, mechanically ventilated, died within 30 days). Multivariable regression models included demographics, cancer status, anticancer therapy and timing, COVID-19-directed therapies, and laboratory measurements (among hospitalized patients).

RESULTS

A total of 4966 patients were included (median age 66 years, 51% female, 50% non-Hispanic white); 2872 (58%) were hospitalized and 695 (14%) died; 61% had cancer that was present, diagnosed, or treated within the year prior to COVID-19 diagnosis. Older age, male sex, obesity, cardiovascular and pulmonary comorbidities, renal disease, diabetes mellitus, non-Hispanic black race, Hispanic ethnicity, worse Eastern Cooperative Oncology Group performance status, recent cytotoxic chemotherapy, and hematologic malignancy were associated with higher COVID-19 severity. Among hospitalized patients, low or high absolute lymphocyte count; high absolute neutrophil count; low platelet count; abnormal creatinine; troponin; lactate dehydrogenase; and C-reactive protein were associated with higher COVID-19 severity. Patients diagnosed early in the COVID-19 pandemic (January-April 2020) had worse outcomes than those diagnosed later. Specific anticancer therapies (e.g. R-CHOP, platinum combined with etoposide, and DNA methyltransferase inhibitors) were associated with high 30-day all-cause mortality.

CONCLUSIONS

Clinical factors (e.g. older age, hematological malignancy, recent chemotherapy) and laboratory measurements were associated with poor outcomes among patients with cancer and COVID-19. Although further studies are needed, caution may be required in utilizing particular anticancer therapies.

CLINICAL TRIAL IDENTIFIER

NCT04354701.

64Cu production by 14 MeV neutron beam

64Cu is an emerging radionuclide of great interest in personalized nuclear medicine. It is produced by a cyclotron via the reaction 64Ni(p,n)64Cu. This production method increased during the last decades, because small biomedical cyclotrons can be easily installed close to the nuclear medicine department of a hospital. As a matter of fact, 64Ni is a very expensive target material. For this reason, an alternative 64Cu production method was investigated at ENEA by using the quasi-monochromatic 14 MeV fusion neutron beam made available at the Frascati Neutron Generator (FNG) located at the ENEA – Frascati Research Center. In particular, two nuclear reactions were studied: 65Cu(n,2n)64Cu and 64Zn(n,p)64Cu. The radiochemical analysis of the activated samples was performed at the ENEA-NMLNWM laboratory located in ENEA-Casaccia Research Center. The activity measurements were carried out at the ENEA-INMRI, located in the ENEA-Casaccia Research Center, with high metrological level conditions and by assuring their traceability to the 64Cu primary activity standard here developed and maintained. A prediction of the 64Cu production by means of the high-brilliance 14 MeV neutron source named Sorgentina is also discussed.

Language of a Long-Term Relationship: Bacterial Inositols and the Intestinal Epithelium

The exact principles guiding host-microbe homeostasis in the intestinal tract remain obscure. In a recent issue of Nature, Wu et al. (2020) describe that bacterial-derived inositols are an important principle that shapes regenerative properties of the colonic epithelium. The metabolites activate HDAC3, which represents an important part of the epigenetic machinery.

Activating Transcription Factor 6 Mediates Inflammatory Signals in Intestinal Epithelial Cells Upon Endoplasmic Reticulum Stress

BACKGROUND & AIMS

Excess and unresolved endoplasmic reticulum (ER) stress in intestinal epithelial cells (IECs) promotes intestinal inflammation. Activating transcription factor 6 (ATF6) is one of the signaling mediators of ER stress. We studied the pathways that regulate ATF6 and its role for inflammation in IECs.

METHODS

We performed an RNA interference screen, using 23,349 unique small interfering RNAs targeting 7783 genes and a luciferase reporter controlled by an ATF6-dependent ERSE (ER stress-response element) promoter, to identify proteins that activate or inhibit the ATF6 signaling pathway in HEK293 cells. To validate the screening results, intestinal epithelial cell lines (Caco-2 cells) were transfected with small interfering RNAs or with a plasmid overexpressing a constitutively active form of ATF6. Caco-2 cells with a CRISPR-mediated disruption of autophagy related 16 like 1 gene (ATG16L1) were used to study the effect of ATF6 on ER stress in autophagy-deficient cells. We also studied intestinal organoids derived from mice that overexpress constitutively active ATF6, from mice with deletion of the autophagy related 16 like 1 or X-Box binding protein 1 gene in IECs (Atg16l1^ΔIEC or Xbp1^ΔIEC, which both develop spontaneous ileitis), from patients with Crohn's disease (CD) and healthy individuals (controls). Cells and organoids were incubated with tunicamycin to induce ER stress and/or chemical inhibitors of newly identified activator proteins of ATF6 signaling, and analyzed by real-time polymerase chain reaction and immunoblots. Atg16l1^ΔIEC and control (Atg16l1^fl/fl) mice were given intraperitoneal injections of tunicamycin and were treated with chemical inhibitors of ATF6 activating proteins.

RESULTS

We identified and validated 15 suppressors and 7 activators of the ATF6 signaling pathway; activators included the regulatory subunit of casein kinase 2 (CSNK2B) and acyl-CoA synthetase long chain family member 1 (ACSL1). Knockdown or chemical inhibition of CSNK2B and ACSL1 in Caco-2 cells reduced activity of the ATF6-dependent ERSE reporter gene, diminished transcription of the ATF6 target genes HSP90B1 and HSPA5 and reduced NF-κB reporter gene activation on tunicamycin stimulation. Atg16l1^ΔIEC and or Xbp1^ΔIEC organoids showed increased expression of ATF6 and its target genes. Inhibitors of ACSL1 or CSNK2B prevented activation of ATF6 and reduced CXCL1 and tumor necrosis factor (TNF) expression in these organoids on induction of ER stress with tunicamycin. Injection of mice with inhibitors of ACSL1 or CSNK2B significantly reduced tunicamycin-mediated intestinal inflammation and IEC death and expression of CXCL1 and TNF in Atg16l1^ΔIEC mice. Purified ileal IECs from patients with CD had higher levels of ATF6, CSNK2B, and HSPA5 messenger RNAs than controls; early-passage organoids from patients with active CD show increased levels of activated ATF6 protein, incubation of these organoids with inhibitors of ACSL1 or CSNK2B reduced transcription of ATF6 target genes, including TNF.

CONCLUSIONS

Ileal IECs from patients with CD have higher levels of activated ATF6, which is regulated by CSNK2B and HSPA5. ATF6 increases expression of TNF and other inflammatory cytokines in response to ER stress in these cells and in organoids from Atg16l1^ΔIEC and Xbp1^ΔIEC mice. Strategies to inhibit the ATF6 signaling pathway might be developed for treatment of inflammatory bowel diseases.

Prdx4 limits caspase-1 activation and restricts inflammasome-mediated signaling by extracellular vesicles

Inflammasomes are cytosolic protein complexes, which orchestrate the maturation of active IL‐1β by proteolytic cleavage via caspase‐1. Although many principles of inflammasome activation have been described, mechanisms that limit inflammasome‐dependent immune responses remain poorly defined. Here, we show that the thiol‐specific peroxidase peroxiredoxin‐4 (Prdx4) directly regulates IL‐1β generation by interfering with caspase‐1 activity. We demonstrate that caspase‐1 and Prdx4 form a redox‐sensitive regulatory complex via caspase‐1 cysteine 397 that leads to caspase‐1 sequestration and inactivation. Mice lacking Prdx4 show an increased susceptibility to LPS‐induced septic shock. This effect was phenocopied in mice carrying a conditional deletion of Prdx4 in the myeloid lineage (Prdx4‐ΔLysMCre). Strikingly, we demonstrate that Prdx4 co‐localizes with inflammasome components in extracellular vesicles (EVs) from inflammasome‐activated macrophages. Purified EVs are able to transmit a robust IL‐1β‐dependent inflammatory response in vitro and also in recipient mice in vivo. Loss of Prdx4 boosts the pro‐inflammatory potential of EVs. These findings identify Prdx4 as a critical regulator of inflammasome activity and provide new insights into remote cell‐to‐cell communication function of inflammasomes via macrophage‐derived EVs.

Exposure to the gut microbiota drives distinct methylome and transcriptome changes in intestinal epithelial cells during postnatal development

BACKGROUND

The interplay of epigenetic processes and the intestinal microbiota may play an important role in intestinal development and homeostasis. Previous studies have established that the microbiota regulates a large proportion of the intestinal epithelial transcriptome in the adult host, but microbial effects on DNA methylation and gene expression during early postnatal development are still poorly understood. Here, we sought to investigate the microbial effects on DNA methylation and the transcriptome of intestinal epithelial cells (IECs) during postnatal development.

METHODS

We collected IECs from the small intestine of each of five 1-, 4- and 12 to 16-week-old mice representing the infant, juvenile, and adult states, raised either in the presence or absence of a microbiota. The DNA methylation profile was determined using reduced representation bisulfite sequencing (RRBS) and the epithelial transcriptome by RNA sequencing using paired samples from each individual mouse to analyze the link between microbiota, gene expression, and DNA methylation.

RESULTS

We found that microbiota-dependent and -independent processes act together to shape the postnatal development of the transcriptome and DNA methylation signatures of IECs. The bacterial effect on the transcriptome increased over time, whereas most microbiota-dependent DNA methylation differences were detected already early after birth. Microbiota-responsive transcripts could be attributed to stage-specific cellular programs during postnatal development and regulated gene sets involved primarily immune pathways and metabolic processes. Integrated analysis of the methylome and transcriptome data identified 126 genomic loci at which coupled differential DNA methylation and RNA transcription were associated with the presence of intestinal microbiota. We validated a subset of differentially expressed and methylated genes in an independent mouse cohort, indicating the existence of microbiota-dependent "functional" methylation sites which may impact on long-term gene expression signatures in IECs.

CONCLUSIONS

Our study represents the first genome-wide analysis of microbiota-mediated effects on maturation of DNA methylation signatures and the transcriptional program of IECs after birth. It indicates that the gut microbiota dynamically modulates large portions of the epithelial transcriptome during postnatal development, but targets only a subset of microbially responsive genes through their DNA methylation status.

99mTc by 99Mo produced at the ENEA-FNG facility of 14MeV neutrons

A severe supply crisis of ⁹⁹Mo, precursor of ^99mTc a diagnostic radionuclide largely used in Nuclear Medicine, occurred in 2008-2009 due to repeated shut-down of the two main (aged) fission reactors. An alternative route for producing ⁹⁹Mo by ¹⁰⁰Mo(n,2n)⁹⁹Mo reaction was investigated at ENEA. The experiment, designed according to Monte Carlo simulations performed with the Fluka code, produced ⁹⁹Mo by irradiating a natural Molybdenum powdered target with 14MeV neutrons produced at the Frascati Neutron Generator. The ⁹⁹Mo specific activity was measured at metrological level by γ-ray spectrometry.

Comparison of 131I activity measurements at the NCBJ RC POLATOM and the ENEA-INMRI linked to the BIPM SIR system

A bilateral comparison between ENEA-INMRI (Italy) and NCBJ RC POLATOM (Poland) of ¹³¹I-solution activity measurements was organized in the year 2015 and piloted by POLATOM, which provided the sources for the comparison. The ¹³¹I master solution was standardized independently at both institutes by using Liquid Scintillation Counting and ionization chamber techniques. The ¹³¹I master solution was then sent by POLATOM to the BIPM International Reference System (SIR). The comparison was registered as an EURAMET.RI(II)-K2.I-131 key comparison allowing the ENEA-INMRI result to enter in the SIR database.

Evidence against solar influence on nuclear decay constants

The hypothesis that proximity to the Sun causes variation of decay constants at permille level has been tested and disproved. Repeated activity measurements of mono-radionuclide sources were performed over periods from 200 days up to four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and are attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha, beta-minus, electron capture, and beta-plus decaying sources set an upper limit of 0.0006% to 0.008% to the amplitude of annual oscillations in the decay rate. Oscillations in phase with Earth's orbital distance to the Sun could not be observed within a 10^-6 to 10^-5 range of precision. There are also no apparent modulations over periods of weeks or months. Consequently, there is no indication of a natural impediment against sub-permille accuracy in half-life determinations, renormalisation of activity to a distant reference date, application of nuclear dating for archaeology, geo- and cosmochronology, nor in establishing the SI unit becquerel and seeking international equivalence of activity standards.

Comparison of (18)F activity measurements at the VNIIM, NPL and the ENEA-INMRI using the SIRTI of the BIPM

In 2014, the first three comparisons of activity measurements of (18)F were carried out at the VNIIM, NPL and the ENEA-INMRI using the BIPM's Transfer Instrument of the International Reference System. The transfer instrument and the NMIs primary measurement methods are briefly described. The degrees of equivalence with the key comparison reference value defined in the frame of the corresponding SIR comparison have been evaluated. World-wide consistency of activity measurements of (18)F is demonstrated.

Oxaliplatin Induced Suicidal Death of Human Erythrocytes

BACKGROUND/AIMS

The alkylating drug oxaliplatin is widely used for chemotherapy of malignancy. Oxaliplatin is effective by inducing both, necrosis and apoptosis. Similar to necrosis or apoptosis of nucleated cells, erythrocytes may enter hemolysis, which is apparent from hemoglobin release or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include oxidative stress and/or Ca2+ entry with increase of cytosolic Ca2+ activity ([Ca2+]i). The present study explored, whether and how oxaliplatin induces eryptosis.

METHODS

Phosphatidylserine exposure at the cell surface was quantified utilizing annexin-V-binding, cell volume estimated from forward scatter, hemolysis deduced from hemoglobin release, [Ca2+]i determined utilizing Fluo-3 fluorescence, and reactive oxygen species (ROS) abundance visualized using 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) dependent fluorescence.

RESULTS

A 48 hours exposure of human erythrocytes to oxaliplatin (10 µg/ml) significantly increased the percentage of annexin-V-binding cells, significantly decreased forward scatter, significantly increased Fluo-3 fluorescence, and significantly increased DCFDA fluorescence. The effect of oxaliplatin on annexin-V-binding and forward scatter was rather augmented by removal of extracellular Ca2+, but was significantly blunted in the presence of the antioxidant N-acetyl-cysteine (1 mM).

CONCLUSIONS

Oxaliplatin triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect partially dependent on ROS formation.

Triggering of Suicidal Erythrocyte Death by Zosuquidar

Background: The P-glycoprotein inhibitor zosuquidar (LY335979) is clinically used to augment the effect of cytostatic drugs on suicidal tumor cell death or apoptosis. The present study explored whether the substance is cytotoxic to erythrocytes. Upon injury, erythrocytes may undergo suicidal cell death or eryptosis, which is characterized by cell shrinkage and translocation of cell membrane phosphatidylserine to the erythrocyte surface. Signaling of eryptosis include increase of cytosolic Ca2+-activity ([Ca2+]i), oxidative stress and activation of several kinases, such as p38 kinase and protein kinase C. Methods: Phosphatidylserine abundance at the erythrocyte surface was quantified from binding of FITC-labelled annexin-V, cell volume from forward scatter, [Ca2+]i from Fluo3-fluorescence, and reactive oxygen species (ROS) from 2′,7′-dichlorodihydrofluorescein diacetate (DCFDA) fluorescence. Results: A 48 h treatment of human erythrocytes with zosuquidar significantly increased the percentage of annexin-V-binding cells (2 and 4 µg/ml), significantly decreased forward scatter (4 µg/ml), significantly increased [Ca2+]i (4 µg/ml), but did not significantly modify ROS. The up-regulation of annexin-V-binding following zosuquidar (4 µg/ml) treatment was significantly blunted by removal of extracellular Ca2+, by presence of p38 kinase inhibitor SB203580 (2 µM) and by presence of protein kinase C inhibitor calphostin (100 nM). Conclusions: Exposure of erythrocytes to zosuquidar triggers suicidal erythrocyte death with erythrocyte shrinkage and erythrocyte membrane scrambling, an effect involving Ca2+ entry and requiring activity of SB203580 and calphostin sensitive kinases.

Edelfosine Induced Suicidal Death of Human Erythrocytes

BACKGROUND/AIMS

The anti-inflammatory, anti-autoimmune, antiparasitic, and anti-viral ether phospholipid edelfosine (1-O-octadecyl-2-O-methylglycero-3-phosphocholine) stimulates apoptosis of tumor cells and is thus considered for the treatment of malignancy. Similar to apoptosis of nucleated cells, erythrocytes may enter eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and phospholipid scrambling of the cell membrane with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include Ca2+ entry with increase of cytosolic Ca2+ activity ([Ca2+]i) and oxidative stress. The present study explored, whether and how edelfosine induces eryptosis.

METHODS

Flow cytometry and photometry, respectively, were employed to estimate phosphatidylserine exposure at the cell surface from annexin-V-binding, cell volume from forward scatter, hemolysis from hemoglobin release, [Ca2+]i from Fluo3-fluorescence, and abundance of reactive oxygen species (ROS) from 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) fluorescence.

RESULTS

A 6 hours exposure of human erythrocytes to edelfosine (5 µM) significantly increased the percentage of annexin-V-binding cells, significantly decreased forward scatter, and significantly increased Fluo3-fluorescence, but did not significantly modify DCFDA fluorescence. The effect of edelfosine on annexin-V-binding was significantly blunted, but not abolished by removal of extracellular Ca2+.

CONCLUSIONS

Edelfosine triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect in part due to stimulation of Ca2+ entry.

Triggering of Suicidal Erythrocyte Death by Ruxolitinib

BACKGROUND/AIMS

The JAK1/JAK2 tyrosine kinase inhibitor ruxolitinib is widely used for the treatment of myeloproliferative neoplasm-associated myelofibrosis and other malignancies. Most important side effects include anemia. A common cause of anemia is accelerated suicidal death of erythrocytes or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Mechanisms contributing to the triggering of eryptosis include oxidative stress, Ca2+ entry with increase of cytosolic Ca2+ activity ([Ca2+]i), and activation of distinct kinases, such as p38 mitogen activated protein (MAP) kinase. The present study explored whether and how ruxolitinib induces eryptosis.

METHODS

Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, hemolysis from hemoglobin release, [Ca2+]i from Fluo3-fluorescence, and ROS formation from DCFDA dependent fluorescence.

RESULTS

A 48 hours exposure of human erythrocytes to ruxolitinib (25 µM) significantly increased the percentage of annexin-V-binding cells and significantly decreased forward scatter. Ruxolitinib did not significantly modify Fluo3-fluorescence and DCFDA fluorescence and the effect of ruxolitinib on annexin-V-binding was not significantly modified by removal of extracellular Ca2+. The effect of ruxolitinib on annexin-V-binding was, however, significantly blunted by the p38 MAP kinase inhibitor SB203580 and virtually abolished by the p38 MAP kinase inhibitor skepinone.

CONCLUSION

Ruxolitinib triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect in part requiring p38 MAP kinase activity.

Stimulation of Suicidal Erythrocyte Death by Garcinol

BACKGROUND/AIMS

The benzophenone garcinol from dried fruit rind of Garcinia indica counteracts malignancy, an effect at least in part due to stimulation of apoptosis. The proapototic effect of garcinol is attributed in part to inhibition of histone acetyltransferases and thus modification of gene expression. Moreover, garcinol triggers mitochondrial depolarisation. Erythrocytes lack gene expression and mitochondria but are nevertheless able to enter apoptosis-like suicidal death or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include oxidative stress, energy depletion and Ca2+ entry with increase of cytosolic Ca2+ activity ([Ca2+]i). The present study explored, whether and how garcinol induces eryptosis.

METHODS

To this end, phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, hemolysis from hemoglobin release, [Ca2+]i from Fluo3-fluorescence, ROS formation from DCFDA dependent fluorescence and cytosolic ATP levels utilizing a luciferin-luciferase-based assay.

RESULTS

A 24 hours exposure of human erythrocytes to garcinol (2.5 or 5 µM) significantly increased the percentage of annexin-V-binding cells. Garcinol decreased (at 1 µM and 2.5 µM) or increased (at 5 µM) forward scatter. Garcinol (5 µM) further increased Fluo3-fluorescence, increased DCFDA fluorescence, and decreased cytosolic ATP levels. The effect of garcinol on annexin-V-binding was significantly blunted, but not abolished by removal of extracellular Ca2+.

CONCLUSIONS

Garcinol triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect in part due to stimulation of ROS formation, energy depletion and Ca2+ entry.

Estimation of sex from the hyoid body in skeletal individuals from archeological sites

Recent forensic studies have shown that the hyoid bone is a sexually dimorphic element of the human skeleton. Given the advanced techniques of collecting human remains in archeological and forensic contexts, the recovery of hyoid bones is now more frequent in skeletal samples. For that reason the authors propose a new method for estimating sex based on hyoid bodies from archeological sites. The study has been conducted on well-preserved hyoids of skeletal remains of 64 adult individuals (44 males and 20 females) dated from the pre-Roman to the medieval periods. The authors considered 10 linear measurements of the hyoid body. The most significant measurements showing sexual dimorphism are the body height, body length, and the maximum and minimum diameter of the articular facet for the greater horn. Discriminant function analysis achieved the allocation accuracy between 75.0% and 88.0%, depending on the measurement collected. This method represents a new, useful and easy way for increasing biological information when assessing the sex of adult human remains from an archeological sample.

Cardiac diastolic evaluation in pregnant women with abnormal glucose tolerance: an opportunity to detect the early and subclinical alterations and prevent cardiovascular diseases

of this study were to assess diastolic function in pregnant women with abnormal glucose tolerance (AGT), compared with normal glucose tolerance (NGT) women, and to evaluate the insulin resistance status and its association with Doppler-echocardiographic indexes. Echocardiograms of 108 consecutive Caucasian women with singleton pregnancies were performed. Insulin resistance status was estimated by the homeostasis model assessment of insulin resistance (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI). All the studied women showed normal diastolic patterns. Patients with AGT (50.9%), as compared with NGT women, had higher HOMA-IR (1.70 ± 1.30 versus 1.01 ± 0.81, P = 0.003), lower QUICKI (0.36 ± 0.005 versus 0.40 ± 0.06, P = 0.004), higher lateral mitral annulus late diastolic velocity (13.6 ± 4.9 versus 11.9 ± 4.9, P = 0.03), and higher A-wave velocity, the wave responsible for the active atrial contraction component (75.2 ± 14.2 versus 67.7 ± 16.2, P = 0.01). At multivariate regression analysis HOMA-IR was the only parameter associated with A-wave velocity. In conclusion, women with AGT had an increased subclinical diastolic active participation, which is associated with higher levels of insulin resistance. For the increased risk of deterioration of cardiac diastolic function, earlier and more seriously than normal pregnancy, AGT women may have a careful followup to detect the early signs of cardiac alteration and to prevent cardiovascular diseases.

Comparison between two absolute methods used for 177Lu activity measurements and its standardization

A (177)Lu primary standard was developed at the ENEA-INMRI in the frame of an international comparison organized by BIPM and piloted by NIST (USA). The CIEMAT/NIST method with (3)H standard source as tracer was used for standardizing a solution of (177)Lu. The activity value was compared also with the measurements of the same mother solution carried out by the 4πγ integral counting method. Particular efforts were made to identify and quantify the long-lived (177m)Lu impurity in the mother solution. The results obtained by the two methods are in good agreement within their standard uncertainties. The arithmetic mean of the two values is in good agreement with the Comparison Reference Value (CRV). By the new primary standard two well-type ionization chambers (ICs), one fixed and the other one portable, were calibrated with an uncertainty lower than 2%. These ICs are used for routinely applications in the activity measurements of short-lived radionuclides particularly useful for medical applications.

Intercomparison of methods for coincidence summing corrections in gamma-ray spectrometry--part II (volume sources)

The second part of an intercomparison of the coincidence summing correction methods is presented. This exercise concerned three volume sources, filled with liquid radioactive solution. The same experimental spectra, decay scheme and photon emission intensities were used by all the participants. The results were expressed as coincidence summing corrective factors for several energies of (152)Eu and (134)Cs, and different source-to-detector distances. They are presented and discussed.

GENDER, SEXUALITY, AND ETHNICITY AS FACTORS OF CLUB DRUG USE AMONG ASIAN AMERICANS

This article examines the relationship between substance use and gender, sexuality, ethnicity, and nativity among 250 Asian American youths involved in the dance club/rave scene. We find distinct patterns of drug use differing by country of origin and ethnicity. However, contrary to some literature we do not find significant differences corresponding to immigration status, or number of years in the U.S. The most significant differences between subgroups are related to gender and sexuality: male respondents consume more drugs, more frequently than female respondents, and non-heterosexual respondents consume more than heterosexual respondents, with differing patterns for men's and women's sexual subgroups. There were also significant gender and sexuality differences with respect to the contexts in which respondents consume drugs, with the most significant differences being between heterosexual and non-heterosexual men. As we discuss, these findings illustrate the need for further investigation of drug use patterns of gender and sexuality within Asian American communities.

Development of simulated air filters for gamma-ray spectrometry proficiency testing

A set of 60 spiked simulated air filter sources was developed for the 2004-2005 proficiency test of the Italian radioactivity surveillance network. Each simulated filter source was prepared by reproducible volumetric dispensing of 19 drops of a mixed radioactive solution containing Co-57, Cs-134, Cs-137, Co-60 and Eu-152. The spiking pattern was investigated and optimized by numerical simulations. The filter sources were checked by double counting on HPGe and NaI(Tl) detectors. The standard deviation (SD) of activity values was 1.5%.

Experimental determination of calibration settings of a commercially available radionuclide calibrator for various clinical measurement geometries and radionuclides

Following the approach of the National Primary Laboratory of the UK (NPL) for the calibration of radionuclide calibrators, but using a commercially available instrument with no data available in the literature, the radionuclide calibrator response was investigated as a function of different measurement geometries at the "Regina Elena" National Cancer Institute (IRE) in Rome. Working with Italian National Metrology Institute for ionising radiation quantities (ENEA-INMRI), specific calibration factors with traceability to national primary standards were determined for different types of glass vials, solid capsules and plastic syringes, investigating three radionuclides with different energy spectra (Tc-99m, In-111, I-131). For each kind of syringe, calibration correction factors for different filling volumes were calculated. For Tc-99m and I-131 the difference between measured and true activity was in the range 2-7%, depending on measurement geometry. For In-111 a large percentage deviation from the true activity value was found in each geometry considered, reaching 35%. The magnitude of this difference is particularly dependent on the energies of the emitted photons.

Random-summing correction and pile-up rejection in the sum-peak method

The sum-peak counting method was applied for 125I absolute activity measurement. Count rate-dependent corrections for random summing and dead time effects were experimentally determined at different count rates and in several experimental conditions. Two NaI(Tl) crystals of different volumes were used. They were connected to pulse recording systems with different characteristics, with or without pile-up rejection live-time corrector circuits (PUR/LTC). A theoretical model was proposed to explain the different behaviours found experimentally. It is shown that count rate-dependent effects are drastically reduced by the use of PUR/LTC.

Close-geometry efficiency calibration of p-type HPGe detectors with a Cs-134 point source

When close-geometry detector calibration is required in gamma-ray spectrometry, single-line emitters are usually used in order to avoid true coincidence summing effects. We managed to overcome this limitation by developing a method for the determination of the efficiency of p-type HPGe detectors in close-geometry with a calibrated Cs-134 point source. No separate determination of coincidence summing correction factors is required and a single measurement furnishes the full-energy-peak efficiencies in the 475-1365 keV energy range.

A preliminary intercomparison of gamma-ray spectrometry on building materials

A preliminary intercomparison on gamma-ray spectrometry determination of natural radionuclides in building materials was carried out in 1999-2002. Samples measured were fly ash, sand and tuff. Laboratories used different experimental equipment and procedures. Corrections for blank, spectral interference, self-absorption and coincidence summing effects were applied in most cases. The agreement between results was within 15-20%, most often within the reported uncertainties. Several general conclusions can be drawn regarding procedures correctness, uncertainty budget, secular equilibrium condition, and radionuclide representativeness in each natural series. Further studies are needed to draw more specific conclusions.

Standardization of 65Zn by 4πPC-γ coincidence counting method with efficiency extrapolation

A 65Zn solution was standardized by the 4piPC-gamma efficiency-extrapolation coincidence counting method. Theoretical aspects of coincidence equations, efficiency equations and linearity conditions are reviewed. Experimental measurements were performed for two low level discrimination thresholds for the PC channel (counting K+L or K X-rays or Auger electrons from EC decay) and for three different settings of the gamma window. Requirements on gamma channel set-up for linear extrapolation were established by using a Pb absorber or by proper gamma window setting. The measured activity values were discussed and found in good agreement with those obtained with a calibrated ionization chamber.

Non-steady-state modelling of faecal coliform removal in deep tertiary lagoons

In Noirmoutier, a French island off the Atlantic coast, secondary effluents flow into a series of four lagoons, 1.4-2.8 m deep, and are reused for agricultural irrigation. The excess water is disposed of to the sea. The aim of this study was to provide a model capable of predicting the microbiological quality of the water pumped for irrigation or discharged to the sea. Meteorological variables, flow rates, physical-chemical characteristics and faecal coliform (FC) contents were monitored for a year and a half. The hydraulic pattern of each lagoon was assumed to be that of completely mixed reactor because of the calculated dispersion numbers and the wind mixing effect. Coliform decay was assumed to follow first order kinetics in each lagoon. Die-off coefficients were calculated in each lagoon using a non-steady-state model. The main bacterial removal mechanism was shown to be solar irradiation. Empirical equations were established to calculate die-off coefficients as a function of received solar energy and temperature. FC die-off rates were higher in the first lagoon and then decreased successively in those following. FC numbers in the different lagoons were predicted with reasonable accuracy in spite of high variation in inlet water quality. The model will facilitate the prediction of water quality under various climatic conditions and different water reuse scenarios and will help to optimise reclamation and storage facilities.

Technical-economic modelling of integrated water management: wastewater reuse in a French island

An integrated technical-economic model is used to address water management issues in the French island of Noirmoutier. The model simulates potable water production and supply, potable and non potable water demand and consumption, wastewater collection, treatment and disposal, water storage, transportation and reuse. A variety of water management scenarios is assessed through technical, economic and environmental evaluation. The scenarios include wastewater reclamation and reuse for agricultural and landscape irrigation as well as domestic non potable application, desalination of seawater and brackish groundwater for potable water supply. The study shows that, in Noirmoutier, wastewater reclamation and reuse for crop irrigation is the most cost-effective solution to the lack of water resources and the protection of sensitive environment. Some water management projects which are regarded as having less economic benefit in the short-term may become competitive in the future, as a result of tightened environmental policy, changed public attitudes and advanced water treatment technologies. The model provides an appropriate tool for water resources planning and management.

Laboratory application of NaI(Tl) gamma-ray spectrometry to studies of natural radioactivity in geophysics

We implemented a laboratory apparatus based on a NaI(TI) gamma-ray spectrometer for the assessment of naturally occurring radioactive materials. This apparatus is devoted to the quantitative determination of U, Th and K in rock and soil samples. We analysed the calibration procedures with particular emphasis to factors which affect accuracy and detection limits. A first series of measurements were compared to those obtained by means of high energy gamma-ray spectrometry. A discussion was made on factors restricting the approach based on scintillation spectrometry, such as secular equilibrium and radon encapsulation.

Development and characterisation of a head calibration phantom for in vivo measurements of actinides

The investigation of actinides' internal contamination in human body makes use of a variety of techniques. In large scale screening the technique of "in vivo" evaluation of bone 241Am burden via the determination of the nuclide activity in the skull is often used. For this purpose, adequate calibration procedures and standard phantoms are needed. The present paper summarises the studies and technical procedures followed for the development of a calibration phantom based on a commercial Alderson angiographic head in which a set of 24 241Am point sources were embedded. A theoretical study was first carried out, at the ENEA Institute for Radiation Protection, using the MCNP4-B Monte Carlo code to determine the point source distribution that closely approximates a homogeneous bone contamination. The numerical models were also used to evaluate the resulting degree of approximation. The point sources were prepared at the ENEA National Metrology Institute for ionising radiation quantities and were traceable to the Italian national standard of radionuclide activity. The sources were prepared by quantitatively dispensing a liquid solution onto a plastic disc. The activity of each source was checked by gamma-ray spectrometry and the reproducibility of the activity values was determined. Each source was then placed in the optimum position in the skull, given by the Monte Carlo modelling, by a precision mechanical device. The phantom was finally used to calibrate a whole body counter operating at the ENEA Institute for Radiation Protection. The paper reports the main theoretical and experimental aspects of this work, and also discusses the results of the first calibrations.

Fast procedures for coincidence-summing correction in gamma-ray spectrometry

Simplified and fast procedures for coincidence-summing correction in gamma-ray spectrometry were investigated. These procedures are based on the usual theoretical expressions of the correction factors, but differ in the determination of the total efficiency curve based on the following approximations: (a) replacement, below the knee efficiency value, of the total efficiency by the full-energy peak efficiency; and (b) use of linear interpolations (in log-log plot) between only two experimental points above the knee efficiency value; or (c) assumption of a peak-to-total efficiency ratio independent on the counting geometry; or (d) assumption of a constant relation between the peak-to-total efficiency ratios and the photoelectric-to-total cross section ratios. The above approximations were separately assumed for determination of the coincidence-summing correction factors for nuclides with complex decay scheme (133Ba, 134Cs, 152Eu) and for 60Co and 88Y measured on a 15% relative efficiency p-type coaxial HPGe detector, for three source-detector geometries: point source placed on top of and at 10 cm from the detector window, and 1 l Marinelli beaker filled with aqueous solution. The results were compared with those based on more accurate experimental determinations of the total efficiency curve from measurements of standard sources of eight different single-gamma-ray emitters. The usefulness of each simplified procedure is evaluated with respect to its accuracy and to the reduction of the number of standard sources and measurement time.

Determination of clozapine, desmethylclozapine and clozapine N-oxide in human plasma by reversed-phase high-performance liquid chromatography with ultraviolet detection

An isocratic high-performance liquid chromatography (HPLC) method with ultraviolet detection for the simultaneous determination of clozapine and its two major metabolites in human plasma is described. Analytes are concentrated from alkaline plasma by liquid-liquid extraction with n-hexane-isoamyl alcohol (75:25, v/v). The organic phase is back-extracted with 150 microl of 0.1 M dibasic phosphate (pH 2.2 with 25% H3PO4). Triprolidine is used as internal standard. For the chromatographic separation the mobile phase consisted of acetonitrile-0.06 M phosphate buffer, pH 2.7 with 25% phosphoric acid (48:52, v/v). Analytes are eluted at a flow-rate of 1.0 ml/min, separated on a 250 x 4.60 mm I.D. analytical column packed with 5 microm C6 silica particles, and measured by UV absorbance detection at 254 nm. The separation requires 7 min. Calibration curves for the three analytes are linear within the clinical concentration range. Mean recoveries were 92.7% for clozapine, 82.0% for desmethylclozapine and 70.4% for clozapine N-oxide. C.V. values for intra- and inter-day variabilities were < or = 13.8% at concentrations between 50 and 1000 ng/ml. Accuracy, expressed as percentage error, ranged from -19.8 to 2.8%. The method was specific and sensitive with quantitation limits of 2 ng/ml for both clozapine and desmethylclozapine and 5 ng/ml for clozapine N-oxide. Among various psychotropic drugs and their metabolites, only 2-hydroxydesipramine caused significant interference. The method is applicable to pharmacokinetic studies and therapeutic drug monitoring.

Retention of patients with a diagnosis of diabetes in selected managed care plans

This study was designed to determine the extent of retention of patients in staff-model HMOs. Study groups with Type II diabetes were compared with a control group without diabetes. Each study group (three groups of approximately 400 patients, drawn from three MCOs) was enrolled in a staff-model HMO in 1990. Patients were then followed for five consecutive years through 1995. The age- and gender-matched control groups (approximately 400 patients randomly selected from each of the three MCOs) were identified from managed care plan enrollees without a diagnosis of diabetes. It was found that the retention rates of patients with diabetes are higher than those without diabetes in two plans. For the third plan, the retention rates among patients with diabetes were the same as the control group's. The first year of enrollment was found to be the most important predictor of patient retention. The findings of this study strongly suggest plans seek methods to optimize treatments and delay the natural history, morbidity, and exacerbations associated with diabetes, since there is a higher probability that these patients will be members in the future.