Shared and Compartment-Specific Processes in Nucleus Pulposus and Annulus Fibrosus During Intervertebral Disc Degeneration

Elucidating how cell populations promote onset and progression of intervertebral disc degeneration (IDD) has the potential to enable more precise therapeutic targeting of cells and mechanisms. Single-cell RNA-sequencing (scRNA-seq) is performed on surgically separated annulus fibrosus (AF) (19,978; 26,983 cells) and nucleus pulposus (NP) (20,884; 24,489 cells) from healthy and diseased human intervertebral discs (IVD). In both tissue types, depletion of cell subsets involved in maintenance of healthy IVD is observed, specifically the immature cell subsets - fibroblast progenitors and stem cells - indicative of an impairment of normal tissue self-renewal. Tissue-specific changes are also identified. In NP, several fibrotic populations are increased in degenerated IVD, indicating tissue-remodeling. In degenerated AF, a novel disease-associated subset is identified, which expresses disease-promoting genes. It is associated with pathogenic biological processes and the main gene regulatory networks include thrombospondin signaling and FOXO1 transcription factor. In NP and AF cells thrombospondin protein promoted expression of genes associated with TGFβ/fibrosis signaling, angiogenesis, and nervous system development. The data reveal new insights of both shared and tissue-specific changes in specific cell populations in AF and NP during IVD degeneration. These identified mechanisms and molecules are novel and more precise targets for IDD prevention and treatment.

[Proposal for participation in intensive care and emergency medicine studies for patients unable to give informed consent (Cologne Model)]

When conducting clinical trials in intensive care and emergency medicine, physicians, ethics committees, and legal experts have differing views regarding the inclusion of patients who are incapable of giving consent. These different views on the participation of patients who are not capable of giving consent also complicate how clinical trials are prepared and conducted. Based on the results of a literature search, a consensus model (Cologne Model) was developed by physicians performing clinical research, ethics committees, and lawyers in order to provide patients, those scientifically responsible for the study, ethics committees, and probate (guardianship) judges with a maximum of patient safety and legal certainty, while simultaneously enabling scientific research.

O-184 Maternally inherited differences in mitochondrial DNA genotype between ART and spontaneously conceived individuals associate with low birthweight

Study question

Can mitochondrial DNA (mtDNA) variants explain the differences in birthweight between ART and spontaneously conceived (SC) individuals and how do they originate?

Summary answer

Children born after ART carry more frequently a different mtDNA variant composition, both maternally inherited and de novo, which are predictive of their birthweight percentile.

What is known already

Children born after ART show an increased risk of lower birthweight and of developing a mild abnormal cardio-metabolic profile later in life. Variation in the mtDNA associates with overall health in the general population, including cardio-metabolic fitness, and can result in changes in mitochondrial function. We hypothesized that mitochondrial DNA variants could explain the differences in birthweight between ART and SC individuals and that these differences may result from maternal transmission and/or from the ovarian stimulation (OS) used in ART.

Study design, size, duration

We deep-sequenced the mtDNA of 472 individuals of who 283 ART and 189 SC, 182 mother-child pairs and 113 single oocytes from both natural menstrual cycles and OS cycles. The mtDNA was compared between groups and Fisher linear discriminant analysis was used as predictive model for the birthweight percentile.

Participants/materials, setting, methods

Mitochondrial DNA was enriched by long-range PCR and subsequently sequenced on an Illumina platform. mtDNA server and MuTect were used for variant calling for variants with a load higher than 1.5%, versus the reference NC_012920.1. An orthogonally rotated factor analysis was used to reduce the dimensionality of the studied dependent variables in the complex data of the heteroplasmic variants.

Main results and the role of chance

ART individuals carried more frequently haplogroup U4 (p = 0.004) and component analysis indicated that they carry a different mtDNA heteroplasmic variant composition than SC individuals (p = 0.01), driven by non-synonymous protein-coding and rRNA-coding variants. These differences were also predictive of the risk of a lower birthweight percentile, especially for the SC children, together with the absence of haplogroup T, the presence of homoplasmic tRNA-variants, pregnancy-induced hypertension and the embryo culture medium used. The differences in heteroplasmic variation observed in the ART children resulted from both maternal transmission (p = 0.03) and de novo mutagenesis (p = 0.02). Mothers of ART children showed a similar mtDNA genotype as their children and differed in the same variant composition when compared to the mothers of SC children (p = 0.03). Furthermore, the comparison of oocytes from the same donors retrieved in natural menstrual cycles and after one OS cycle showed that OS does not increase de novo mutagenesis. Additionally, clinical parameters such as the total dosage of FSH units, the number of oocytes retrieved, and maternal age did not show any correlation with the differences observed in ART individuals.

Limitations, reasons for caution

This study is observational with no functional tests being performed.

Wider implications of the findings

We demonstrate an association between a lower birthweight percentile and a mtDNA variant composition which is more frequently carried by ART children. These non-disease associated mtDNA variants could cause a suboptimal mitochondrial function affecting the birthweight. Long-term health consequences of these differences remain to be further elucidated.

Trial registration number

Not applicable

POS0852 HIGH DOSE INTRAVENOUS PULSE METHOTREXATE IN REFRACTORY EOSINOPHILIC FASCIITIS: WHAT ARE THE ADVERSE EVENTS?

Background:

Eosinophilic Fasciitis (EF) is a disease of unknown origin initially characterized by limb or trunk edema, and collagenous thickening of the subcutaneous fascia in later stages. Eosinophilia in peripheral blood is commonly observed. Being a rare disease, evidence regarding treatment is mainly based on case series and anecdotal evidence. The mainstay systemic treatment is prednisone, and Methotrexate (MTX) up to doses of 25 mg/week is the leading prednisone-sparing agent. Mycophenolate can be considered in refractory cases. As an alternative we explored the use of intravenous (i.v.) pulse MTX. We already showed this to be a potentially effective and safe treatment option in a prospective single-arm study1, but more data on adverse events (AEs) are needed.

Objectives:

To present an overview of AEs of high dose i.v. pulse MTX in refractory EF.

Methods:

Adult patients with EF based on clinical appearance combined with histology and/or MRI, who were unresponsive to prednisone combined with low-dose MTX or presenting with severe disease, were selected for this retrospective cohort study. Patients received 6-9 monthly infusions of 4 mg/kg MTX followed by oral folinic acid rescue therapy, which is comparable to treatment schedules for trophoblast disease. An additional number of six pulses could be administered in case of a partial effect or flare. Safety data were monitored during each visit and classified according to the Common Terminology Criteria for Adverse Events (CTCAE) from the National Institute of Health (2009).

Results:

Twenty-seven patients (26 with EF, one with deep linear morphea) were included in this study (five males), with a mean age of 59 (sd 11.5) years, based on clinical presentation and histology and/or MRI. Previous treatment data were available for 22 patients of which 21 received oral prednisone (20-60 mg) whether or not combined with low dose MTX and/or UVA1 therapy. All patients reported ≥ 1 AEs at some stage, exactly 100 in total. ‘Gastro-intestinal disorders’ (n=36) and ‘General disorders and administration site conditions’ (n=15) were most common; especially nausea (n=6) and fatigue (n=11). One patient was hospitalized for blood transfusion. In four cases, treatment was discontinued due to AEs (acute kidney injury (AKI), depression, nausea/vomiting, and leukopenia resp.). Each reported AE appeared reversible. The patient with AKI had an MTX level in the toxic range; methotrexate-induced crystal nephropathy seemed the most likely explanation, probably due to a combination of high body weight (and thus high absolute dosage of MTX) and the concomitant use of omeprazole. Oral folinic acid rescue therapy was prolonged, together with 500 cc i.v. fluid, after which kidney function normalized.

Organ systemAEFrequencyGastro-intestinal disordersNausea, oral mucositis, diarrhea, vomiting, abdominal pain, anorexia36General disorders, administration site conditionsMalaise, fatigue15Respiratory, thoracic, mediastinal disordersCough and dyspnea10Skin and subcutaneous tissue disordersSkin hyperpigmentation, hair loss, alopecia, other9Nervous systemHeadache, nerve abducens disorder7Infections and infestinationsSkin, urinary tract, upper respiratory tract, other6Blood, lymphatic system disordersAnemia, leukopenia, pancytopenia4Psychiatric conditionsDepression3Renal, urinary disordersAcute Kidney Injury1Other systems9100

Conclusion:

AEs were common among patients receiving high dose i.v. pulse MTX, especially nausea and fatigue, but were generally mild and reversible in all cases. This is in line with studies performed with patients with trophoblast disease. One episode of reversible AKI occurred that seemed to be related to high body weight and the use of concomitant medication. The safety profile of i.v. pulse MTX thus seems auspicious, but the case of AKI illustrates that further data on safety is needed.

References:

[1]Mertens JS et al. High-dose intravenous pulse methotrexate in patients with eosinophilic fasciitis. JAMA Dermatol 2016; 1(152):1262-5.

Disclosure of Interests:

None declared

The effect of polymorphisms in FSHR and FSHB genes on ovarian response: a prospective multicenter multinational study in Europe and Asia

STUDY QUESTION

Does the presence of single nucleotide polymorphisms (SNPs) in the FSH receptor gene (FSHR) and/or FSH beta subunit-encoding gene (FSHB) influence ovarian response in predicted normal responders treated with rFSH?

SUMMARY ANSWER

The presence of FSHR SNPs (rs6165, rs6166, rs1394205) has a statistically significant impact in ovarian response, although this effect is of minimal clinical relevance in predicted normal responders treated with a fixed dose of 150 IU rFSH.

WHAT IS KNOWN ALREADY

Ovarian reserve markers have been a breakthrough in response prediction following ovarian stimulation. However, a significant percentage of patients show a disproportionate lower ovarian response, as compared with their actual ovarian reserve. Studies on pharmacogenetics have demonstrated a relationship between FSHR or FSHB genotyping and drug response, suggesting a potential effect of individual genetic variability on ovarian stimulation. However, evidence from these studies is inconsistent, due to the inclusion of patients with variable ovarian reserve, use of different starting gonadotropin doses, and allowance for dose adjustments during treatment. This highlights the necessity of a well-controlled prospective study in a homogenous population treated with the same fixed protocol.

STUDY DESIGN, SIZE, DURATION

We conducted a multicenter multinational prospective study, including 368 patients from Vietnam, Belgium, and Spain (168 from Europe and 200 from Asia), from November 2016 until June 2019. All patients underwent ovarian stimulation followed by oocyte retrieval in an antagonist protocol with a fixed daily dose of 150 IU rFSH until triggering. Blood sampling and DNA extraction was performed prior to oocyte retrieval, followed by genotyping of four SNPs from FSHR (rs6165, rs6166, rs1394205) and FSHB (rs10835638).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Eligible were predicted normal responder women <38 years old undergoing their first or second ovarian stimulation cycle. Laboratory staff and clinicians were blinded to the clinical results and genotyping, respectively. The prevalence of hypo-responders, the number of oocytes retrieved, the follicular output rate (FORT), and the follicle to oocyte index (FOI) were compared between different FSHR and FSHB SNPs genotypes.

MAIN RESULTS AND THE ROLE OF CHANCE

The prevalence of derived allele homozygous SNPs in the FSHR was rs6166 (genotype G/G) 15.8%, rs6165 (genotype G/G) 34.8%, and rs1394205 (genotype A/A) 14.1%, with significant differences between Caucasian and Asian women (P < 0.001). FSHB variant rs10835638 (c.-211 G>T) was very rare (0.5%). Genetic model analysis revealed that the presence of the G allele in FSHR variant rs6166 resulted in less oocytes retrieved when compared to the AA genotype (13.54 ± 0.46 vs 14.81 ± 0.61, estimated mean difference (EMD) -1.47 (95% CI -2.82 to -0.11)). In FSHR variant rs1394205, a significantly lower number of oocytes was retrieved in patients with an A allele when compared to G/G (13.33 ± 0.41 vs 15.06 ± 0.68, EMD -1.69 (95% CI -3.06 to -0.31)). A significantly higher prevalence of hypo-responders was found in patients with the genotype A/G for FSHR variant rs6166 (55.9%, n = 57) when compared to A/A (28.4%, n = 29), ORadj 1.87 (95% CI 1.08-3.24). No significant differences were found regarding the FORT across the genotypes for FSHR variants rs6166, rs6165, or rs1394205. Regarding the FOI, the presence of the G allele for FSHR variant rs6166 resulted in a lower FOI when compared to the A/A genotype, EMD -13.47 (95% CI -22.69 to -4.24). Regarding FSHR variant rs6165, a lower FOI was reported for genotype A/G (79.75 ± 3.35) when compared to genotype A/A (92.08 ± 6.23), EMD -13.81 (95% CI -25.41 to -2.21).

LIMITATIONS, REASONS FOR CAUTION

The study was performed in relatively young women with normal ovarian reserve to eliminate biases related to age-related fertility decline; thus, caution is needed when extrapolating results to older populations. In addition, no analysis was performed for FSHB variant rs10835638 due to the very low prevalence of the genotype T/T (n = 2).

WIDER IMPLICATIONS OF THE FINDINGS

Based on our results, genotyping FSHR SNPs rs6165, rs6166, rs1394205, and FSHB SNP rs10835638 prior to initiating an ovarian stimulation with rFSH in predicted normal responders should not be recommended, taking into account the minimal clinical impact of such information in this population. Future research may focus on other populations and other genes related to folliculogenesis or steroidogenesis.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by an unrestricted grant by Merck Sharp & Dohme (MSD). N.P.P. reports grants and/or personal fees from MSD, Merck Serono, Roche Diagnostics, Ferring International, Besins Healthcare, Gedeon Richter, Theramex, and Institut Biochimique SA (IBSA). N.L.V. and M.T.H. report consultancy and conference fees from Merck, Ferring, and MSD, outside the submitted work. P.D. has received honoraria for lecturing and/or research grants from MSD, Ferring International, and Merck. D.S. reports grants and/or personal fees from MSD, Ferring International, Merck Serono, Cook, and Gedeon Richter. A.R.N., B.A.M., C.S., J.M., L.H.L., P.Q.M.M., H.T., and S.G. report no conflict of interests.

TRIAL REGISTRATION NUMBER

NCT03007043.

Facetime vs. Screentime: Gaze Patterns to Live and Video Social Stimuli in Adolescents with ASD

Atypical eye gaze to social stimuli is one of the most frequently reported and studied social behaviors affected by autism spectrum disorder (ASD). The vast majority of this literature is based on analyses of gaze patterns as participants view social information, such as talking faces, on a computer screen. However, recent results suggest that generalizing gaze behaviors from computer screens to live interactions may not be valid. This study examines between- and within-group differences in gaze behaviors of children with ASD and their neurotypical (NT) peers during a screen-based and a live-interaction task. Results show between-group differences in gaze only for the screen-based, but not the live-interaction task. We also find that gaze behavior of NT children during the screen-based task significantly correlates with their gaze behavior during the live interaction; individuals who direct a higher percentage of gaze to the face in one task also did so in the other task. However, there is no significant relationship between the gaze patterns of children with ASD for those two tasks. These results strongly caution against using gaze of individuals with ASD recorded during screen-based tasks as a proxy for understanding their gaze behavior during live social interactions.

How Anxious Do You Think I Am? Relationship Between State and Trait Anxiety in Children With and Without ASD During Social Tasks

Individuals with autism spectrum disorder (ASD) often exhibit increased anxiety, even in non-stressful situations. We investigate general anxiousness (anxiety trait) and responses to stressful situations (anxiety state) in 22 adolescents with ASD and 32 typically developing controls. We measured trait anxiety with standardized self- and parent-reported questionnaires. We used a Biopac system to capture state anxiety via skin conductance responses, mean heart rate and heart rate variability during high- and low-anxiety tasks. Results reveal higher trait anxiety in adolescents with ASD (p < 0.05) and no group difference in state anxiety. Increased parent-reported trait anxiety may predict decreased state anxiety during high-stress conditions. Together, these findings suggest that higher trait anxiety may result in dampened physical responses to stress.

Safe and successful resection of difficult GI lesions using a novel single-step full-thickness resection device (FTRD®)

BACKGROUND AND STUDY AIMS

Classic endoscopic resection techniques (EMR and ESD) are limited to mucosal lesions. In the case of deeper growth into the gut wall and anatomic sites prone to perforation, the novel full-thickness resection device (FTRD^®) opens a new dimension of possibilities for endoscopic resection.

PATIENTS AND METHODS

Sixty patients underwent endoscopic full-thickness resection (eFTR) at our institution. Safety, learning curve, R0 resection rate, and clinical outcome were studied.

RESULTS

In 97% (58/60) of the interventions, the FTRD^®-mounted endoscope reached the previously marked lesion and eFTR was performed (technical success). Full-thickness resection was achieved in 88% of the cases, with an R0 resection on histological examination in 79%. The clinical success rate based on follow-up histology was even higher (88%). Adverse events occurred in 7%. Appendicitis of the residual cecal appendix after eFTR of an adenoma arising in the appendix led to the only post-eFTR surgery (1/58, 2%). Minor bleeding at the eFTR site (2/58, 3%) and an eFTR performed accidently without proper prior deployment of the OTSC^® (1/58, 2%) were successfully treated endoscopically. There was no secondary perforation or eFTR-associated mortality.

CONCLUSIONS

After specific training, eFTR is a feasible, safe, and promising all-in-one endoscopic resection technique. Our data show that eFTR allows complete resection of lesions affecting layers of the gut wall beneath the mucosa with a low risk of adverse events. However, our preliminary results need to be confirmed in larger, controlled studies.

Transplantationsmedizin in der Intensivmedizin

Die Betreuung von Patienten vor und nach einer Organtransplantation gehört zum Gebiet der „speziellen Intensivmedizin“ des jeweiligen Fachbereichs. Die transplantationsspezifische Intensivmedizin setzt daher ein interdisziplinäres Management voraus. Neben der Organprotektion bzw. dem Monitoring von speziellen transplantationsrelevanten Problemen steht die Immunsuppression. Auf das Management mit Immunsuppressiva und von transplantationsassoziierten, intensivmedizinisch relevanten Problemen wird in diesem Kapitel eingegangen. Speziell werden Herz-, Lungen-, Leber-, Nieren- und Stammzelltransplantationen dargestellt.

Spondias tuberosa Arruda (Anacardiaceae), a threatened tree of the Brazilian Caatinga?

Abstract Spondias tuberosa Arr., a fructiferous tree endemic to the northeast Brazilian tropical dry forest called Caatinga, accounts for numerous benefits for its ecosystem as well as for the dwellers of the Caatinga. The tree serves as feed for pollinators and dispersers as well as fodder for domestic ruminants, and is a source of additional income for local smallholders and their families. Despite its vantages, it is facing several man-made and natural threats, and it is suspected that S. tuberosa could become extinct. Literature review suggests that S. tuberosa suffers a reduced regeneration leading to population decrease. At this juncture S. tuberosa cannot be considered threatened according to the International Union for Conservation of Nature Red List Categories and Criteria, as it has not yet been assessed and hampered generative regeneration is not considered in the IUCN assessment. The combination of threats, however, may have already caused an extinction debt for S. tuberosa. Due to the observed decline in tree density, a thorough assessment of the S. tuberosa population is recommended, as well as a threat assessment throughout the entire Caatinga.

Tracking Optical Welding through Groove Modes in Plasmonic Nanocavities

We report the light-induced formation of conductive links across nanometer-wide insulating gaps. These are realized by incorporating spacers of molecules or 2D monolayers inside a gold plasmonic nanoparticle-on-mirror (NPoM) geometry. Laser irradiation of individual NPoMs controllably reshapes and tunes the plasmonic system, in some cases forming conductive bridges between particle and substrate, which shorts the nanometer-wide plasmonic gaps geometrically and electronically. Dark-field spectroscopy monitors the bridge formation in situ, revealing strong plasmonic mode mixing dominated by clear anticrossings. Finite difference time domain simulations confirm this spectral evolution, which gives insights into the metal filament formation. A simple analytic cavity model describes the observed plasmonic mode hybridization between tightly confined plasmonic cavity modes and a radiative antenna mode sustained in the NPoM. Our results show how optics can reveal the properties of electrical transport across well-defined metallic nanogaps to study and develop technologies such as resistive memory devices (memristors).

Arsenate uptake by Al nanoclusters and other Al-based sorbents during water treatment

In many parts of the world, arsenic from geogenic and anthropogenic sources deteriorates the quality of drinking water resources. Effective methods of arsenic removal include adsorption and coagulation with iron- and aluminum-based materials, of which polyaluminum chloride is widely employed as coagulant in water treatment due to its low cost and high efficiency. We compared the arsenic uptake capacity and the arsenic bonding sites of different Al-based sorbents, including Al nanoclusters, polyaluminum chloride, polyaluminum granulate, and gibbsite. Extended X-ray absorption fine structure (EXAFS) spectroscopy revealed that As(V) forms bidentate-binuclear complexes in interaction with all Al-based removal agents. The octahedral configuration of nanoclusters and the distribution of sorption sites remain the same in all types of removal agents consisting of nano-scale Al oxyhydroxide particles. The obtained distances for As(V)-O and As(V)-Al agreed with previously published data and were found to be 1.69 ± 0.02 Å and 3.17-3.21 Å, respectively. Our study suggests that As(V) binds to Al nanoclusters as strongly as to Al oxide surfaces. The As sorption capacity of Al nanoclusters was found to be very similar to that of Al clusters in a polyaluminum chloride. The most efficient Al-based sorbents for arsenic removal were Al nanoclusters, followed by polyaluminum granulate.

[Stress fracture or osteochondral lesion of the navicular bone?]

BACKGROUND

An osteochondral lesion of the navicular bone in the foot is rare. Differentiation from a stress fracture is difficult, since both lesions usually present as vague pain in the midfoot in active young adults. However, the typical location differs. SPECT-CT allows an etiological diagnosis to be made. As management differs for the two lesions, a correct diagnosis is important.

CASE DESCRIPTION

A 19-year-old male athlete had pain in the dorsal right midfoot on weight-bearing. A diagnosis of 'stress fracture of the navicular bone' was made on the basis of SPECT-CT. Since conservative therapy did not help, and because the location was atypical for a stress fracture, the diagnosis was revised to 'osteochondral lesion'.

CONCLUSION

The key to the diagnosis of osteochondral lesion is its location in the central proximal third of the navicular bone. Patients with this type of lesion often undergo surgical treatment, whereas conservative therapy is sufficient in case of a stress fracture.

Nonlinear superchiral meta-surfaces: tuning chirality and disentangling non-reciprocity at the nanoscale

Circularly polarized light is incident on a nanostructured chiral meta-surface. In the nanostructured unit cells whose chirality matches that of light, superchiral light is forming and strong optical second harmonic generation can be observed.

Propofol sedation for colonoscopy with a new ultrathin or a standard endoscope: a prospective randomized controlled study

BACKGROUND AND STUDY AIMS

The majority of colonoscopies in Germany are performed under conscious sedation. Previous studies reported that pediatric colonoscopes reduce the demand for sedative drugs and may improve cecal intubation. The aim of this study was to compare a new ultrathin and a standard colonoscope in terms of propofol demand during colonoscopy.

PATIENTS AND METHODS

A total of 203 patients were prospectively randomized to undergo colonoscopy with either a 9.5-mm ultrathin (UTC) colonoscope or a standard colonoscope of variable stiffness. Initially, 40 or 60 mg of propofol were administered according to body weight, followed by bolus injections of 20 mg as deemed necessary. Propofol was administered by a separate physician who was blinded to the endoscope used. Sedation levels were defined according to guidelines; pain and complaints were recorded on a numeric rating scale.

RESULTS

Significantly less propofol was required to reach the cecum with the UTC (adjusted mean 94.9 mg [95 % confidence interval (CI) 85.7 - 105.0] vs. 115.3 mg [95 %CI 105.8 - 124.7]; P = 0.003). The level of sedation and pain score were lower with the UTC (sedation level 1 76 % vs. 61 %; P = 0.003; pain score adjusted mean 2.0 [95 %CI 1.7 - 2.4] vs. 2.8 [95 %CI 2.5 - 3.1]; P = 0.001). The rate of ileal and cecal intubation, time to reach the cecum, number of external compressions, withdrawal time, polyp and adenoma detection rate, and patient satisfaction were not different between the two colonoscopes. The time to intubate the ileum was longer with the UTC (1.73 minutes [95 %CI 1.42 - 2.04] vs. 1.22 minutes [95 %CI 0.91 - 1.52]; P = 0.020).

CONCLUSIONS

Use of a new ultrathin colonoscope was associated with reduced propofol consumption, lower patient sedation levels, and less pain than the standard colonoscope, but ileal intubation time was longer.

Adsorption of arsenic on polyaluminum granulate

The kinetics and efficiencies of arsenite and arsenate removal from water were evaluated using polyaluminum granulates (PAG) with high content of aluminum nanoclusters. PAG was characterized to be meso- and macroporous, with a specific surface area of 35 ± 1 m(2) g(-1). Adsorption experiments were conducted at pH 7.5 in deionized water and synthetic water with composition of As-contaminated groundwater in the Pannonian Basin. As(III) and As(V) sorption was best described by the Freundlich and Langmuir isotherm, respectively, with a maximum As(V) uptake capacity of ~200 μmol g(-1) in synthetic water. While As(III) removal reached equilibrium within 40 h, As(V) was removed almost entirely within 20 h. Micro X-ray fluorescence and electron microscopy revealed that As(III) was distributed uniformly within the grain, whereas As(V) diffused up to 81 μm into PAG. The results imply that As(V) is adsorbed 3 times faster while being transported 10(5) times slower than As(III) in Al hydroxide materials.

Value of DCE-MRI and FDG-PET/CT in the prediction of response to preoperative chemotherapy with bevacizumab for colorectal liver metastases

Background:

The purpose of this study was to assess the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and ¹⁸F-fluorodeoxyglucose positron emission tomography computed tomography (FDG-PET/CT) for evaluation of response to chemotherapy and bevacizumab and for prediction of progression-free survival (PFS) in patients with metastatic colorectal cancer (mCRC) with potentially resectable liver lesions.

Methods:

A total of 19 mCRC patients were treated with FOLFOX/FOLFIRI and bevacizumab followed by surgery. Dynamic contrast-enhanced magnetic resonance imaging and FDG-PET/CT were performed before treatment and after cycle 5. PET results were quantified by calculating maximum standardised uptake value (SUV_max) whereas area under the enhancement curve (AUC), initial AUC (iAUC) and the endothelial transfer constant (K^trans) were used to quantify DCE-MRI. Pathological analysis of the resection specimen was performed, including measurement of microvessel density (MVD) and proliferation index.

Results:

Both AUC and iAUC were significantly decreased following bevacizumab therapy (median change of 22% (P=0.002) and 40% (P=0.001) for AUC and iAUC, respectively). Progression-free survival benefit was shown for patients with >40% reduction in K^trans (P=0.019). In the group of radiological responders, the median baseline SUV_max was 3.77 (IQR: 2.88–5.60) compared with 7.20 (IQR: 4.67–8.73) in nonresponders (P=0.021). A higher follow-up SUV_max was correlated with worse PFS (P=0.012). Median MVD was 10.9. Progression-free survival was significantly shorter in patients with an MVD greater than 10, compared with patients with lower MVD (10 months compared with 16 months, P=0.016).

Conclusion:

High relative decrease in K^trans, low follow-up SUV_max and low MVD are favourable prognostic factors for mCRC patients treated with bevacizumab before surgery.

Polyaluminum chloride with high Al30 content as removal agent for arsenic-contaminated well water

Polyaluminum chloride (PACl) is a well-established coagulant in water treatment with high removal efficiency for arsenic. A high content of Al(30) nanoclusters in PACl improves the removal efficiency over broader dosage and pH range. In this study we tested PACl with 75% Al(30) nanoclusters (PACl(Al30)) for the treatment of arsenic-contaminated well water by laboratory batch experiments and field application in the geothermal area of Chalkidiki, Greece, and in the Pannonian Basin, Romania. The treatment efficiency was studied as a function of dosage and the nanoclusters' protonation degree. Acid-base titration revealed increasing deprotonation of PACl(Al30) from pH 4.7 to the point of zero charge at pH 6.7. The most efficient removal of As(III) and As(V) coincided with optimal aggregation of the Al nanoclusters at pH 7-8, a common pH range for groundwater. The application of PACl(Al30) with an Al(tot) concentration of 1-5mM in laboratory batch experiments successfully lowered dissolved As(V) concentrations from 20 to 230 μg/L to less than 5 μg/L. Field tests confirmed laboratory results, and showed that the WHO threshold value of 10 μg/L was only slightly exceeded (10.8 μg/L) at initial concentrations as high as 2300 μg/L As(V). However, As(III) removal was less efficient (<40%), therefore oxidation will be crucial before coagulation with PACl(Al30). The presence of silica in the well water improved As(III) removal by typically 10%. This study revealed that the Al(30) nanoclusters are most efficient for the removal of As(V) from water resources at near-neutral pH.

Copper toxicity to bioluminescent Nitrosomonas europaea in soil is explained by the free metal ion activity in pore water

The terrestrial biotic ligand model (BLM) for metal toxicity in soil postulates that metal toxicity depends on the free metal ion activity in solution and on ions competing for metal sorption to the biotic ligand. Unequivocal evidence for the BLM assumptions is most difficult to obtain for native soil microorganisms because the abiotic and biotic compartments cannot be experimentally separated. Here, we report copper (Cu) toxicity to a bioluminescent Nitrosomonas europaea reporter strain that was used in a solid phase-contact assay and in corresponding soil extracts and artificial soil solutions. The Cu(2+) ion activities that halve bioluminescence (EC50) in artificial solutions ranged 10(-5) to 10(-7) M and increased with increasing activities of H(+), Ca(2+) and Mg(2+) according to the BLM concept. The solution based Cu(2+) EC50 values of N. europaea in six contaminated soils ranged 2 × 10(-6) to 2 × 10(-9) M and these thresholds for both solid phase or soil extract based assays were well predicted by the ion competition model fitted to artificial solution data. In addition, solution based Cu(2+) EC50 of the solid phase-contact assay were never smaller than corresponding values in soil extracts suggesting no additional solid phase toxic route. By restricting the analysis to the same added species, we show that the Cu(2+) in solution represents the toxic species to this bacterium.

High throughput optical readout of dense arrays of nanomechanical systems for sensing applications

We present an instrument based on the scanning of a laser beam and the measurement of the reflected beam deflection that enables the readout of arrays of nanomechanical systems without limitation in the geometry of the sample, with high sensitivity and a spatial resolution of few micrometers. The measurement of nanoscale deformations on surfaces of cm(2) is performed automatically, with minimal need of user intervention for optical alignment. To exploit the capability of the instrument for high throughput biological and chemical sensing, we have designed and fabricated a two-dimensional array of 128 cantilevers. As a proof of concept, we measure the nanometer-scale bending of the 128 cantilevers, previously coated with a thin gold layer, induced by the adsorption and self-assembly on the gold surface of several self-assembled monolayers. The instrument is able to provide the static and dynamic responses of cantilevers with subnanometer resolution and at a rate of up to ten cantilevers per second. The instrumentation and the fabricated chip enable applications for the analysis of complex biological systems and for artificial olfaction.

Functional relevance of the IRF-1 promoter polymorphism rs2549009 on transcriptional activity in a native genomic environment

Interferon regulatory factor-1 (IRF-1), a transcription regulator involved both in inducing and in mediating the effects of interferon, is encoded by a highly polymorphic gene in different ethnic populations. Some of these genetic variations have been described to be associated to disease traits in hepatitis C virus and in human immunodeficiency virus infection, including one single-nucleotide polymorphism rs2549009 within the promoter region. This study aimed at investigating the functional relevance of rs2549009 on IRF-1 transcriptional activity in peripheral blood mononuclear cells in its natural genomic environment. Haplotype-specific chromatin immunoprecipitation using antibodies directed against both the transcriptionally inactive and active RNA polymerase II (RNAPII) and allele-specific transcript quantification techniques were applied to ex vivo-derived samples from healthy heterozygous donors. Inactive serine 5 phosphorylated RNAPII was found to be preferentially bound to the rs2549009 A allele in all donors investigated. Active serine 2 phosphorylated (ser2-P) RNAPII, in contrast, was found to be precipitable, depending on the donor, preferentially either with the A or the G promoter variants or without any preference. The ratio of rs2549009 A/G promoter variants engaged by ser2-P RNAPII was closely related to the relative frequency of the respective IRF-1 transcripts, and relative allelic expression was found to be associated to total IRF-1 gene expression. These results provide evidence for a bidirectional IRF-1 gene expression imbalance that appears not to be solely controlled by rs2549009 in cis and may rely on a yet unidentified variant or haplotype or on environmental control in trans.

Monod kinetics rather than a first-order degradation model explains atrazine fate in soil mini-columns: implications for pesticide fate modelling

Pesticide transport models commonly assume first-order pesticide degradation kinetics for describing reactive transport in soil. This assumption was assessed in mini-column studies with associated batch degradation tests. Soil mini-columns were irrigated with atrazine in two intermittent steps of about 30 days separated by 161 days application of artificial rain water. Atrazine concentration in the effluent peaked to that of the influent concentration after initial break-through but sharply decreased while influx was sustained, suggesting a degradation lag phase. The same pattern was displayed in the second step but peak height and percentage of atrazine recovered in the effluent were lower. A Monod model with biomass decay was successfully calibrated to this data. The model was successfully evaluated against batch degradation data and mini-column experiments at lower flow rate. The study suggested that first-order degradation models may underestimate risk of pesticide leaching if the pesticide degradation potential needs amplification during degradation.

The Cu(+)-assisted radioiodination Kit: Mechanistic study of unexplored parameters concerning the acidity and redox properties of the reaction medium

Nucleophilic Cu(+)-assisted radioiodination can be optimally performed at pH approximately 2.3 by using conventional reducing agents such as gentisic acid and SnSO(4), mixed or separately. A mechanistic overview of the Cu(+)-radioiodination method is presented in the extended pH-range of 1-4.4. At lower pH, these usual reducing agents show a distinct behaviour. Oxidizing acids (HSO(4)(-), H(3)PO(4)) must be avoided, where as redox neutral acids (trifluoroacetic acid or methanesulfonic acid) or reducing acids (H(2)SO(3), H(3)PO(2)) are well tolerated. The presence of reducing acids makes the use of the usual reducing agents redundant.