Prognosis of prosthetic valve infective endocarditis due to Streptococcus spp., a retrospective multi-site study to assess the impact of antibiotic treatment duration

PURPOSE

The duration of antibiotic treatment for prosthetic valve endocarditis caused by Streptococcus spp. is largely based on clinical observations and expert opinion rather than empirical studies. Here we assess the impact of a shorter antibiotic duration.

OBJECTIVES

To assess the impact of antibiotic treatment duration for streptococcal prosthetic valve endocarditis on 12-month mortality as well as subsequent morbidity resulting in additional cardiac surgical interventions, and rates of relapse and reinfection.

METHODS

This retrospective multisite (N= 3) study examines two decades of data on patients with streptococcal prosthetic valve endocarditis receiving either 4 or 6 weeks of antibiotics. Overall mortality, relapse, and reinfection rates were also assessed for the entire available follow-up period.

RESULTS

The sample includes 121 patients (median age 72 years, IQR [53; 81]). The majority (74%, 89/121) received a ß-lactam antibiotic combined with aminoglycoside in 74% (89/121, median bi-therapy 5 days [1; 14]). Twenty-eight patients underwent surgery guided by ESC-guidelines (23%). The 12-month mortality rate was not significantly affected by antibiotic duration (4/40, 10% in the 4-week group vs 3/81, 3.7% in the 6-week group, p=0.34) or aminoglycoside usage (p=0.1). Similarly, there were no significant differences between the 2 treatment groups for secondary surgical procedures (7/40 vs 21/81, p=0.42), relapse or reinfection (1/40 vs 2/81 and 2/40 vs 5/81 respectively).

CONCLUSIONS

Our study found no increased adverse outcomes associated with a 4-week antibiotic duration compared to the recommended 6-week regimen. Further randomized trials are needed to ascertain the optimal duration of treatment for streptococcal endocarditis.

Prevalence of 2-year "No evidence of disease activity" (NEDA-3 and NEDA-4) in relapsing-remitting multiple sclerosis. A real-world study

BACKGROUND

No evidence of disease activity (NEDA) is becoming a gold standard in the evaluation of disease modifying therapies (DMT) in relapsing-remitting multiple sclerosis (RRMS). NEDA-3 status is the absence of relapses, new activity on brain MRI, and disability progression. NEDA-4 meets all NEDA-3 criteria plus lack of brain atrophy.

OBJECTIVE

Aim of this study was to investigate the prevalence of two-year NEDA-3, NEDA-4, six-month delayed NEDA-3 (6mdNEDA-3), and six-month delayed NEDA-4 (6mdNEDA-4) in a cohort of patients with RRMS. Six-month delayed measures were introduced to consider latency of action of drugs.

METHODS

Observational retrospective monocentric study. All the patients with RRMS starting DMT between 2015 and 2018, and with 2-year of follow-up, were included. Annualized brain volume loss (a-BVL) was calculated by SIENA software.

RESULTS

We included 108 patients, the majority treated with first line DMT. At 2-year follow-up, 35 % of patients were NEDA-3 (50 % 6mdNEDA-3), and 17 % NEDA-4 (28 % 6mdNEDA-4). Loss of NEDA-3 status was mainly driven by MRI activity (70 %), followed by relapses (56 %), and only minimally by disability progression (7 %).

CONCLUSION

In our cohort 2-year NEDA status, especially including lack of brain atrophy, was hard to achieve. Further studies are needed to establish the prognostic value of NEDA-3 and NEDA4 in the long-term follow-up.

Hybrid electronic-photonic sensors on a fibre tip

Most sensors rely on a change in an electrical parameter to the measurand of interest. Their direct readout via an electrical wire and an electronic circuit is, in principle, technically simple, but it is subject to electromagnetic interference, preventing its application in several industrial environments. Fibre-optic sensors can overcome these limitations because the sensing region and readout region can be spaced apart, sometimes by kilometres. However, fibre-optic sensing typically requires complex interrogation equipment due to the extremely high wavelength accuracy that is required. Here we combine the sensitivity and flexibility of electronic sensors with the advantages of optical readout, by demonstrating a hybrid electronic-photonic sensor integrated on the tip of a fibre. The sensor is based on an electro-optical nanophotonic structure that uses the strong co-localization of static and electromagnetic fields to simultaneously achieve a voltage-to-wavelength transduction and a modulation of reflectance. We demonstrate the possibility of reading the current-voltage characteristics of the electro-optic diode through the fibre and therefore its changes due to the environment. As a proof of concept, we show the application of this method to cryogenic temperature sensing. This approach allows fibre-optic sensing to take advantage of the vast toolbox of electrical sensing modalities for many different measurands.

Optimising mopane worm (Gonimbrasia belina) processing for improved nutritional and microbial quality

Mopane worms (Gonimbrasia belina) is an important source of food and contribute to the nutrition of people who consume them. However, the traditional processing methods may have detrimental effects on the nutritional value and should also guarantee microbial quality. In this study, the nutritional composition and microbial quality of mopane worms processed under different boiling time (0-20 min) and drying temperature (40-60 °C) conditions were investigated and optimised using response surface methodology. An increase in the boiling time at the lowest drying temperature resulted in an increase in protein content and reduction in coliform counts. The optimum conditions of boiling for 20 min and drying at 40 °C resulted in mopane worms with a protein content of 49.4% DW and coliform counts <1.5 log cfu/g. In addition, high concentrations of crude fibre (13.6% DW) and fat (20.2% DW), as well as Fe (19.0 mg/100 g) and Zn (17.9 mg/100 g) were also recorded. A decrease in the total bacterial count, Escherichia coli and yeasts and moulds at the boiling time ≥20 min irrespective of the drying temperature suggested that exposure to heat reduced the microbial growth and contamination. Reduction of the mopane worms' moisture content (<7%) due to drying further slowed down the rate of microbial growth. The optimal processing conditions (boiling for 20 min and drying at 40 °C) are recommended for pretreatment of mopane worms prior to further processing into various products.

Leukocyte Telomere Length Variability as a Potential Biomarker in Patients with PolyQ Diseases

SCA1, SCA2, and SCA3 are the most common forms of SCAs among the polyglutamine disorders, which include Huntington’s Disease (HD). We investigated the relationship between leukocyte telomere length (LTL) and the phenotype of SCA1, SCA2, and SCA3, comparing them with HD. The results showed that LTL was significantly reduced in SCA1 and SCA3 patients, while LTL was significantly longer in SCA2 patients. A significant negative relationship between LTL and age was observed in SCA1 but not in SCA2 subjects. LTL of SCA3 patients depend on both patient’s age and disease duration. The number of CAG repeats did not affect LTL in the three SCAs. Since LTL is considered an indirect marker of an inflammatory response and oxidative damage, our data suggest that in SCA1 inflammation is present already at an early stage of disease similar to in HD, while in SCA3 inflammation and impaired antioxidative processes are associated with disease progression. Interestingly, in SCA2, contrary to SCA1 and SCA3, the length of leukocyte telomeres does not reduce with age. We have observed that SCAs and HD show a differing behavior in LTL for each subtype, which could constitute relevant biomarkers if confirmed in larger cohorts and longitudinal studies.

An alternative, zeaxanthin epoxidase-independent abscisic acid biosynthetic pathway in plants

Abscisic acid (ABA) is an important carotenoid-derived phytohormone that plays essential roles in plant response to biotic and abiotic stresses as well as in various physiological and developmental processes. In Arabidopsis, ABA biosynthesis starts with the epoxidation of zeaxanthin by the ABA DEFICIENT 1 (ABA1) enzyme, leading to epoxycarotenoids; e.g., violaxanthin. The oxidative cleavage of 9-cis-epoxycarotenoids, a key regulatory step catalyzed by 9-CIS-EPOXYCAROTENOID DIOXYGENASE, forms xanthoxin, which is converted in further reactions mediated by ABA DEFICIENT 2 (ABA2), ABA DEFICIENT 3 (ABA3), and ABSCISIC ALDEHYDE OXIDASE 3 (AAO3) into ABA. By combining genetic and biochemical approaches, we unravel here an ABA1-independent ABA biosynthetic pathway starting upstream of zeaxanthin. We identified the carotenoid cleavage products (i.e., apocarotenoids, β-apo-11-carotenal, 9-cis-β-apo-11-carotenal, 3-OH-β-apo-11-carotenal, and 9-cis-3-OH-β-apo-11-carotenal) as intermediates of this ABA1-independent ABA biosynthetic pathway. Using labeled compounds, we showed that β-apo-11-carotenal, 9-cis-β-apo-11-carotenal, and 3-OH-β-apo-11-carotenal are successively converted into 9-cis-3-OH-β-apo-11-carotenal, xanthoxin, and finally into ABA in both Arabidopsis and rice. When applied to Arabidopsis, these β-apo-11-carotenoids exert ABA biological functions, such as maintaining seed dormancy and inducing the expression of ABA-responsive genes. Moreover, the transcriptomic analysis revealed a high overlap of differentially expressed genes regulated by β-apo-11-carotenoids and ABA, suggesting that β-apo-11-carotenoids exert ABA-independent regulatory activities. Taken together, our study identifies a biological function for the common plant metabolites, β-apo-11-carotenoids, extends our knowledge about ABA biosynthesis, and provides new insights into plant apocarotenoid metabolic networks.

Intestinal malrotation in one adult patient affected by SARS-CoV-2 infection: occlusion misdiagnosed as COVID gastroenteritis. Case report and literature review

Malrotation of the gut is a rare occurrence, commonly diagnosed during childhood, but occasionally diagnosed in adults.

In children, intestinal obstruction is the most common manifestation, whereas in adult patients, the diagnosis is more challenging since the symptoms are less specific with several episodes of abdominal pain and vomit.

In a particular epidemic period, like the one we are going through, these generic symptoms may mislead to a wrong diagnosis.

We present the case of a young man in which occlusion due to intestinal malrotation has been misinterpreted as gastroenteric symptoms of severe acute respiratory syndrome coronavirus 2 infection, and we also overview the correct Ladd’s technique, commonly performed by pediatrical surgeon, but unusual operation for adult general surgeons.

Secondary cluster headache due to a contralateral demyelinating periaqueductal gray matter lesion

OBJECTIVES/BACKGROUND

Tension-type headache and migraine without aura are the most common primary headaches occurring in people with demyelinating diseases, whereas cluster headache (CH) can be considered exceptional. The location of demyelinating lesions could be strategic in these cases, involving areas interacting with the trigeminovascular system.

METHODS AND RESULTS

We report a case of a 54-year-old woman with right-sided CH as the initial manifestation of multiple sclerosis and showing a left dorsal brainstem lesion on magnetic resonance imaging, in the region of the dorsal longitudinal fasciculus (DLF).

CONCLUSION

Our case seems to suggest a possible role of the DLF in the process that leads to CH attacks. Because neuroimaging clearly showed a lesion contralateral to CH pain, we hypothesize that some fibers from periaqueductal gray matter project to the contralateral side, besides the known ipsilateral connections.

Several geranylgeranyl diphosphate synthase isoforms supply metabolic substrates for carotenoid biosynthesis in tomato

Geranylgeranyl diphosphate (GGPP) produced by GGPP synthase (GGPPS) serves as a precursor for many plastidial isoprenoids, including carotenoids. Phytoene synthase (PSY) converts GGPP into phytoene, the first committed intermediate of the carotenoid pathway. Here we used biochemical, molecular, and genetic tools to characterise the plastidial members of the GGPPS family in tomato (Solanum lycopersicum) and their interaction with PSY isoforms. The three tomato GGPPS isoforms found to localise in plastids (SlG1, 2 and 3) exhibit similar kinetic parameters. Gene expression analyses showed a preferential association of individual GGPPS and PSY isoforms when carotenoid biosynthesis was induced during root mycorrhization, seedling de-etiolation and fruit ripening. SlG2, but not SlG3, physically interacts with PSY proteins. By contrast, CRISPR-Cas9 mutants defective in SlG3 showed a stronger impact on carotenoid levels and derived metabolic, physiological and developmental phenotypes compared with those impaired in SlG2. Double mutants defective in both genes could not be rescued. Our work demonstrates that the bulk of GGPP production in tomato chloroplasts and chromoplasts relies on two cooperating GGPPS paralogues, unlike other plant species such as Arabidopsis thaliana, rice or pepper, which produce their essential plastidial isoprenoids using a single GGPPS isoform.

FRI0439 PET-CT IN THE ASSESSMENT OF OSTEOARTICULAR INFECTIONS ASSOCIATED WITH INFECTIVE ENDOCARDITIS

Background:

Five to eleven percent of infective endocarditis (IE) are associated with a musculoskeletal infection. Thanks to its good sensitivity, the use of PET-CT in this pathology makes it possible to confirm the diagnosis by seeking valvular hypermetabolism but also by mapping distant septic foci.

Objectives:

The main objective of our study was to assess the prevalence of osteoarticular fixation (OAF) with PET-CT, symptomatic or not, in patients with IE. The secondary objectives were to determine predictive factors for osteoarticular infections such as the type of valve damage (native or prosthetic) and germ.

Methods:

This study was carried out on the basis of a prospective cohort of patients admitted in the department of cardiology in Henri Mondor Hospital for IE suspicion between August 2015 and July 2019. Demographic, clinical, bacteriological, imaging and therapeutic data have been collected. Patients matching Duke’s modified criteria according to ESC 2015 (Duke + IE) and / or a cardiac fixation according to standard whole-body PET-CT were included in the analysis. All of the PET-CT scans were reviewed by a nuclear medicine specialist to confirm whether or not there was a heart condition and to look for septic-looking OAF.

Results:

From this cohort, we included 90 IE Duke + patients and 42 patients with cardiac PET-CT fixation (including 31 IE Duke +). In the IE Duke + group, we found OAF in 18 patients (20%), 39% of whom were asymptomatic. There were 9 spondylodiscitis (4 on the cervical level, 7 on the thoracic level, and 2 on the lumbar level), 5 glenohumeral arthritis, 2 coxofemoral arthritis, 1 sternoclavicular arthritis and 1 sacroiliac arthritis. The IE affected the aortic valve in 50% of the cases and the mitral valve in 22%. In other cases, the infection involved the internal automatic defibrillator (ICD) or the pacemaker. The valves were prosthetic in 73% of the cases. The bacterial ecology was mainly represented by Enterococcus faecalis (39%) then staphylococcus aureus (17%) against 14% and 13% respectively in the entire IE Duke + group. In the group with cardiac PET-CT fixation, OAF was found in 10 patients (40%), 70% of whom were asymptomatic. Among them, there were 5 spondylodiscitis (2 cervico- thoracic and 3 exclusively thoracic), 2 glenohumeral arthritis (20%), 2 coxofemoral arthritis and 1 sternoclavicular arthritis. The IE affected the aortic valve in 60% of the cases, mitral in 30% of the cases and it was an infection on ICD in 10% of the cases. The main germs found were Enterococcus faecalis (30% of cases) and Staphylococcus epidermidis (20% of cases).

Conclusion:

In patients with IE, PET-CT seems to be interesting in detection of osteoarticular infections, and consequently, could impact the diagnosis and the treatment modalities. In our cohort, 1 patient in 5 had an OAF and nearly 40% of them were asymptomatic. The overrepresentation of enterococcus is consistent with recent data in the literature

References:

[1]Dahl A, Iversen K, Tonder N, Hoest N, Arpi M, Dalsgaard M, et al. Prevalence of Infective Endocarditis in Enterococcus faecalis Bacteremia. J Am Coll Cardiol. 16 juill 2019;74(2):193‑201.

Disclosure of Interests:

Benjamin HUGUES: None declared, Bérivan EMSEN: None declared, Julien TERNACLE: None declared, Raphaëlle HUGUET: None declared, Antonio FIORE: None declared, Raphaëlle LEPEULE: None declared, Xavier Chevalier: None declared, Mukedaisi ABULIZI: None declared, Florent Eymard Consultant of: Regenlab

Bioinformatics Resources for Plant Abiotic Stress Responses: State of the Art and Opportunities in the Fast Evolving -Omics Era

Abiotic stresses are among the principal limiting factors for productivity in agriculture. In the current era of continuous climate changes, the understanding of the molecular aspects involved in abiotic stress response in plants is a priority. The rise of -omics approaches provides key strategies to promote effective research in the field, facilitating the investigations from reference models to an increasing number of species, tolerant and sensitive genotypes. Integrated multilevel approaches, based on molecular investigations at genomics, transcriptomics, proteomics and metabolomics levels, are now feasible, expanding the opportunities to clarify key molecular aspects involved in responses to abiotic stresses. To this aim, bioinformatics has become fundamental for data production, mining and integration, and necessary for extracting valuable information and for comparative efforts, paving the way to the modeling of the involved processes. We provide here an overview of bioinformatics resources for research on plant abiotic stresses, describing collections from -omics efforts in the field, ranging from raw data to complete databases or platforms, highlighting opportunities and still open challenges in abiotic stress research based on -omics technologies.

Manipulation of β-carotene levels in tomato fruits results in increased ABA content and extended shelf life

Tomato fruit ripening is controlled by the hormone ethylene and by a group of transcription factors, acting upstream of ethylene. During ripening, the linear carotene lycopene accumulates at the expense of cyclic carotenoids. Fruit-specific overexpression of LYCOPENE β-CYCLASE (LCYb) resulted in increased β-carotene (provitamin A) content. Unexpectedly, LCYb-overexpressing fruits also exhibited a diverse array of ripening phenotypes, including delayed softening and extended shelf life. These phenotypes were accompanied, at the biochemical level, by an increase in abscisic acid (ABA) content, decreased ethylene production, increased density of cell wall material containing linear pectins with a low degree of methylation, and a thicker cuticle with a higher content of cutin monomers and triterpenoids. The levels of several primary metabolites and phenylpropanoid compounds were also altered in the transgenic fruits, which could be attributed to delayed fruit ripening and/or to ABA. Network correlation analysis and pharmacological experiments with the ABA biosynthesis inhibitor, abamine, indicated that altered ABA levels were a direct effect of the increased β-carotene content and were in turn responsible for the extended shelf life phenotype. Thus, manipulation of β-carotene levels results in an improvement not only of the nutritional value of tomato fruits, but also of their shelf life.

UGT709G1: a novel uridine diphosphate glycosyltransferase involved in the biosynthesis of picrocrocin, the precursor of safranal in saffron (Crocus sativus)

Saffron, a spice derived from the dried red stigmas of Crocus sativus, is one of the oldest natural food additives. The flowers have long red stigmas, which store significant quantities of the glycosylated apocarotenoids crocins and picrocrocin. The apocarotenoid biosynthetic pathway in saffron starts with the oxidative cleavage of zeaxanthin, from which crocins and picrocrocin are derived. In the processed stigmas, picrocrocin is converted to safranal, giving saffron its typical aroma. By a targeted search for differentially expressed uridine diphosphate glycosyltransferases (UGTs) in Crocus transcriptomes, a novel apocarotenoid glucosyltransferase (UGT709G1) from saffron was identified. Biochemical analyses revealed that UGT709G1 showed a high catalytic efficiency toward 2,6,6-trimethyl-4-hydroxy-1-carboxaldehyde-1-cyclohexene (HTCC), making it suited for the biosynthesis of picrocrocin, the precursor of safranal. The role of UGT709G1 in picrocrocin/safranal biosynthesis was supported by the absence or presence of gene expression in a screening for HTCC and picrocrocin production in different Crocus species and by a combined transient expression assay with CsCCD2L in Nicotiana benthamiana leaves. The identification of UGT709G1 completes one of the most highly valued specialized metabolic biosynthetic pathways in plants and provides novel perspectives on the industrial production of picrocrocin to be used as a flavor additive or as a pharmacological constituent.

Multi-species transcriptome analyses for the regulation of crocins biosynthesis in Crocus

BACKGROUND

Crocins are soluble apocarotenoids that mainly accumulate in the stigma tissue of Crocus sativus and provide the characteristic red color to saffron spice, in addition to being responsible for many of the medicinal properties of saffron. Crocin biosynthesis and accumulation in saffron is developmentally controlled, and the concentration of crocins increases as the stigma develops. Until now, little has been known about the molecular mechanisms governing crocin biosynthesis and accumulation. This study aimed to identify the first set of gene regulatory processes implicated in apocarotenoid biosynthesis and accumulation.

RESULTS

A large-scale crocin-mediated RNA-seq analysis was performed on saffron and two other Crocus species at two early developmental stages coincident with the initiation of crocin biosynthesis and accumulation. Pairwise comparison of unigene abundance among the samples identified potential regulatory transcription factors (TFs) involved in crocin biosynthesis and accumulation. We found a total of 131 (up- and downregulated) TFs representing a broad range of TF families in the analyzed transcriptomes; by comparison with the transcriptomes from the same developmental stages from other Crocus species, a total of 11 TF were selected as candidate regulators controlling crocin biosynthesis and accumulation.

CONCLUSIONS

Our study generated gene expression profiles of stigmas at two key developmental stages for apocarotenoid accumulation in three different Crocus species. Differential gene expression analyses allowed the identification of transcription factors that provide evidence of environmental and developmental control of the apocarotenoid biosynthetic pathway at the molecular level.

The Specialized Roles in Carotenogenesis and Apocarotenogenesis of the Phytoene Synthase Gene Family in Saffron

Crocus sativus stigmas are the main source of crocins, which are glucosylated apocarotenoids derived from zeaxanthin cleavage that give saffron its red color. Phytoene synthase (PSY) mediates the first committed step in carotenoid biosynthesis in plants. Four PSY genes encoding functional enzymes were isolated from saffron. All the proteins were localized in plastids, but the expression patterns of each gene, CsPSY1a, CsPSY1b, CsPSY2, and CsPSY3, in different saffron tissues and during the development of the stigma showed different tissue specialization. The CsPSY2 transcript was primarily detected in the stigmas where it activates and stimulates the accumulation of crocins, while its expression was very low in other tissues. In contrast, CsPSY1a and CsPSY1b were mainly expressed in the leaves, but only CsPSY1b showed stress-light regulation. Interestingly, CsPSY1b showed differential expression of two alternative splice variants, which differ in the intron retention at their 5' UTRs, resulting in a reduction in their expression levels. In addition, the CsPSY1a and CsPSY1b transcripts, together with the CsPSY3 transcript, were induced in roots under different stress conditions. The CsPSY3 expression was high in the root tip, and its expression was associated with mycorrhizal colonization and strigolactone production. CsPSY3 formed a separate branch to the stress-specific Poaceae homologs but was closely related to the dicot PSY3 enzymes.

Anti-stiction coating for mechanically tunable photonic crystal devices

A method to avoid the stiction failure in nano-electro-opto-mechanical systems has been demonstrated by coating the system with an anti-stiction layer of Al₂O₃ grown by atomic layer deposition techniques. The device based on a double-membrane photonic crystal cavity can be reversibly operated from the pull-in back to its release status. This enables to electrically switch the wavelength of a mode over ~50 nm with a potential modulation frequency above 2 MHz. These results pave the way to reliable nano-mechanical sensors and optical switches.

Baropodometry on patients after total knee arthroplasty

PURPOSE

It is well known that total knee replacement surgery decreases pain and improves function, but the effect on postural assessment needs to be studied better with the use of new technological devices. Total knee arthroplasty (TKA) improves motor coordination and stability of the knee. On the other hand, changing joint functionality can modify the balance. The aim of this trial is to record and analyze the static and dynamic baropodometric data of patients in the first few months following joint replacement. For the physiatrist, this tool can be useful to check if the rehabilitation treatment protocols and times are correct.

METHODS

We designed a prospective observation longitudinal study to assess postural stability following TKA. Between December 2014 and May 2015, sixty consecutive patients were recruited through local orthopedic physician offices and hospitals. The patients scheduled to undergo TKA were recruited and were monitored before surgery (T0) and at 1 (T1), 3 (T2) and 6 months (T3) after knee surgery. The correction of varus/valgus deviation at X-ray and the Knee Society Score were performed to verify the functional recovery. We used static and dynamic baropodometric analysis to evaluate postural assessment.

RESULTS

After surgery, there was a significant improvement in physiological alignment of knee axes (p < 0.0001) and of Knee and Function Scores (excellent, mean values 80.5 and 80.7, respectively, p < 0.0001). The static analysis showed that the center of gravity and the pressure on the foot of the operated limb were corrected toward the physiological center (p < 0.0001) and the body weight displaced to the forefeet and to the hindfeet reduced bilaterally (p < 0.0001). The type of footprint did not change. The dynamic analysis confirmed the significant normalization of the pressure on the foot of the operated limb at all follow-ups (p < 0.0001). The percentage of load was reduced on the operated limb (p = 0.0096) and speed of step, cadence and semi-step length increased (p < 0.0001).

CONCLUSION

These data show the progressive recovery of stability after TKA from the immediate postoperative to the subsequent months. The clinical and functional improvement correlated with a load redistribution between the two limbs. The baropodometry could be an excellent noninvasive method for monitoring effects of rehabilitation treatment.

Ultralow Surface Recombination Velocity in Passivated InGaAs/InP Nanopillars

The III-V semiconductor InGaAs is a key material for photonics because it provides optical emission and absorption in the 1.55 μm telecommunication wavelength window. However, InGaAs suffers from pronounced nonradiative effects associated with its surface states, which affect the performance of nanophotonic devices for optical interconnects, namely nanolasers and nanodetectors. This work reports the strong suppression of surface recombination of undoped InGaAs/InP nanostructured semiconductor pillars using a combination of ammonium sulfide, (NH₄)₂S, chemical treatment and silicon oxide, SiO_x, coating. An 80-fold enhancement in the photoluminescence (PL) intensity of submicrometer pillars at a wavelength of 1550 nm is observed as compared with the unpassivated nanopillars. The PL decay time of ∼0.3 μm wide square nanopillars is dramatically increased from ∼100 ps to ∼25 ns after sulfur treatment and SiO_x coating. The extremely long lifetimes reported here, to our knowledge the highest reported to date for undoped InGaAs nanostructures, are associated with a record-low surface recombination velocity of ∼260 cm/s. We also conclusively show that the SiO_x capping layer plays an active role in the passivation. These results are crucial for the future development of high-performance nanoscale optoelectronic devices for applications in energy-efficient data optical links, single-photon sensing, and photovoltaics.

Waveguide-coupled nanopillar metal-cavity light-emitting diodes on silicon

Nanoscale light sources using metal cavities have been proposed to enable high integration density, efficient operation at low energy per bit and ultra-fast modulation, which would make them attractive for future low-power optical interconnects. For this application, such devices are required to be efficient, waveguide-coupled and integrated on a silicon substrate. We demonstrate a metal-cavity light-emitting diode coupled to a waveguide on silicon. The cavity consists of a metal-coated III–V semiconductor nanopillar which funnels a large fraction of spontaneous emission into the fundamental mode of an InP waveguide bonded to a silicon wafer showing full compatibility with membrane-on-Si photonic integration platforms. The device was characterized through a grating coupler and shows on-chip external quantum efficiency in the 10⁻⁴–10⁻² range at tens of microamp current injection levels, which greatly exceeds the performance of any waveguide-coupled nanoscale light source integrated on silicon in this current range. Furthermore, direct modulation experiments reveal sub-nanosecond electro-optical response with the potential for multi gigabit per second modulation speeds.

Despite much progress, nanoscale light sources suitable for photonic integration are lacking. Here, the authors present a metal-cavity nanopillar LED on a silicon substrate working at telecommunications wavelengths, which demonstrates compatibility with membrane-on-Si photonic integration platforms.

Effects of the self-myocardial retroperfusion with aortic-coronary sinus shunt on cardiac output and ischemic events in high-risk patients undergoing OPCAB surgery

AIM

Despite controversies, off-pump coronary artery bypass (OPCAB) surgery has become a routine procedure. Obvious advantages have been demonstrated in high-risk patients. However, OPCAB surgery has limitations in specific high-risk situations with hazards of operative deleterious events. We describe an innovative procedure of self-myocardial retroperfusion (SMR) with an aortic-coronary sinus shunt (ACSS). We prospectively evaluated the protective effects and benefits of SMR in high-risk coronary patients with impaired LVEF.

METHODS

Eighteen consecutive high-risk (ES>10) coronary patients (mean age: 65.94 years; range: 34-85; mean ES: 26.97%) with LVEF≤35% who were not eligible for IABP were assigned for OPCAB surgery. Following sternotomy, the cardiac indexes (CI) were measured before, during SMR and after completion of coronary artery bypasses. Operative events with and without SMR were accurately collected, and postoperative cardiac Troponin T release was measured.

RESULTS

OPCAB procedures were performed in all patients. Intraoperative use of SMR significantly increased CI (P=3.1041810.10-8) and reversed deleterious operative events (ECG changes/low cardiac output). Hospital mortality was 0%. Incidence of transient atrial fibrillation was 33.33%. Neither stroke nor renal insufficiency was observed. The mean graft number/patient was 2.05. Mean postoperative cardiac Troponin T value was 0.79 μg/L. Beating heart preservation optimized by SMR contributed to reduce ischemia-reperfusion injury, as validated by an immediate increase of CI after completion of coronary bypasses (P=3.35009.10-9).

CONCLUSION

The concept of SMR with an ACSS during OPCAB procedures definitely improved CI and reversed ischemic features in high-risk patients and should be considered as an operative temporary myocardial assistance.

Position-Dependent Local Detection Efficiency in a Nanowire Superconducting Single-Photon Detector

We probe the local detection efficiency in a nanowire superconducting single-photon detector along the cross-section of the wire with a far subwavelength resolution. We experimentally find a strong variation in the local detection efficiency of the device. We demonstrate that this effect explains previously observed variations in NbN detector efficiency as a function of device geometry.

Bacterial metabarcoding by 16S rRNA gene ion torrent amplicon sequencing

Ion Torrent is a next generation sequencing technology based on the detection of hydrogen ions produced during DNA chain elongation; this technology allows analyzing and characterizing genomes, genes, and species. Here, we describe an Ion Torrent procedure applied to the metagenomic analysis of 16S rRNA gene amplicons to study the bacterial diversity in food and environmental samples.

Role of TachoSil® in distal pancreatectomy: a single center experience

AIM

Distal pancreatectomies (DP) are associated with high risk of postoperative complications, and in many series higher morbidity rate than duodenopancreatectomies has been reported. To evaluate the role of a collagen sponge with human fibrinogen and thrombin film (TachoSil®) in limiting the incidence of complications after DP.

METHODS

From 1996 to 2013, 221 patients have been submitted to distal pancreatectomy (± splenectomy) in our Division. A retrospective analysis has been conducted in a group of 36 consecutive and prospectively collected DP treated with intraoperative placement of TachoSil® on pancreatic stump from 2010 to 2013 (group 1). A control series of 36 consecutive patients (group 2) was matched 1:1 from hystorical database. The variables considered in the analysis were: age, gender, ASA score, pancreatic texture (hard vs. soft), histology, operative time, postoperative mortality, morbility (postoperative pancreatic fistula - POPF, postoperative hemorrage - PPH, delayed gastric emptying - DGE) and hospital stay. Differences between POPF, PPH, DGE and hospital stays between grops were investigated with χ² and t-Student test. Univariate analysis was conducted to determine factors related to POPF development. Statistical analysis was performed using freeware Microsoft Excel based program.

RESULTS

Post operative mortality was 0% in both groups. POPF were registered in 36.1% (13/36) and 41.6 % (15/36) in groups 1 and 2, respectively (P=n.s.); in group 1 we didn't observe grade C POPF, while 4 patients in control group developed grade C POPF (P<0,05). No differences were found between two groups in terms of incidence of PPH and DGE. The median duration of postoperative hospital stay in group 1 was 21.8 (7-189) days compared with 31.13 (9-249) days in group 2 (P<0.001).

CONCLUSION

The use of TachoSil® seems to be associated with lower incidence of grade C POPF but larger controlled trials are needed to surely assess the usefulness of TachoSil® in pancreatic surgery in order to reduce pancreatic specific complications and their severity.

Prognostic factors of extracorporeal shock wave therapy for tendinopathies

INTRODUCTION

Extracorporeal shock wave therapy is very widely used for the management of tendinopathies and plantar fasciitis.

AIM

The aim of the study is to determine whether there are prognostic factors that may influence the outcome of extracorporeal shock wave therapy for these diseases.

METHODS

Three hundred fifty-five patients were analyzed 2 months after shock wave treatment for rotator cuff tendinitis, epicondylitis, Achilles tendinopathy, trocanteritis, jumper's knee or plantar fasciitis. We recorded the epidemiological, clinical and treatment protocol, and these data were correlated with treatment outcome.

RESULTS

Clinical improvement was achieved in 45.9 % of these patients. We discovered that laterality different to the dominant limb (p < 0.0001) and repeated shock wave treatments (p = 0.004) are prognostic factors in an unsuccessful therapy, while being male (p = 0.015) and a high body mass index (p = 0.004) are factors for success. We found no differences in relation to age, diet, blood type, work or sport activity, presence of co-morbidities, drugs, type of tendinopathy, density of energy delivered and other physiotherapy treatment. Knowledge of these prognostic factors may lead to improved insight for physicians and physiotherapists to predict the extent of the recovery and adjust rehabilitation and patient expectations accordingly.

hERG1 channels drive tumour malignancy and may serve as prognostic factor in pancreatic ductal adenocarcinoma

Background:

hERG1 channels are aberrantly expressed in human cancers. The expression, functional role and clinical significance of hERG1 channels in pancreatic ductal adenocarcinoma (PDAC) is lacking.

Methods:

hERG1 expression was tested in PDAC primary samples assembled as tissue microarray by immunohistochemistry using an anti-hERG1 monoclonal antibody (α-hERG1-MoAb). The functional role of hERG1 was studied in PDAC cell lines and primary cultures. ERG1 expression during PDAC progression was studied in Pdx-1-Cre,LSL-Kras^G12D/+,LSL-Trp53^R175H/+ transgenic (KPC) mice. ERG1 expression in vivo was determined by optical imaging using Alexa-680-labelled α-hERG1-MoAb.

Results:

(i) hERG1 was expressed at high levels in 59% of primary PDAC; (ii) hERG1 blockade decreased PDAC cell growth and migration; (iii) hERG1 was physically and functionally linked to the Epidermal Growth Factor-Receptor pathway; (iv) in transgenic mice, ERG1 was expressed in PanIN lesions, reaching high expression levels in PDAC; (v) PDAC patients whose primary tumour showed high hERG1 expression had a worse prognosis; (vi) the α-hERG1-MoAb could detect PDAC in vivo.

Conclusions:

hERG1 regulates PDAC malignancy and its expression, once validated in a larger cohort also comprising of late-stage, non-surgically resected cases, may be exploited for diagnostic and prognostic purposes in PDAC either ex vivo or in vivo.

A decade with nucleic acid-based microbiological methods in safety control of foods

In the last decade, nucleic acid-based methods gradually started to replace or complement the culture-based methods and immunochemical assays in routine laboratories involved in food control. In particular, real-time polymerase chain reaction (PCR) was technically developed to the stage of good speed, sensitivity and reproducibility, at minimized risk of carry-over contamination. Basic advantages provided by nucleic acid-based methods are higher speed and added information, such as subspecies identification, information on the presence of genes important for virulence or antibiotic resistance. Nucleic acid-based methods are attractive also to detect important foodborne pathogens for which no classical counterparts are available, namely foodborne pathogenic viruses. This review briefly summarizes currently available or developing molecular technologies that may be candidates for involvement in microbiological molecular methods in the next decade. Potential of nonamplification as well as amplification methods is discussed, including fluorescent in situ hybridization, alternative PCR chemistries, alternative amplification technologies, digital PCR and nanotechnologies.

Efficacy of TachoSil® as a sutureless hemostatic patch to repair a perforation of the interventricular groove during endocardial radiofrequency ablation

Catheter ablation is a well-established therapeutic option for management of recurrent ventricular tachycardia in patients with ischemic/non-ischemic heart disease and procedural complications include a mortality rate of up to 3% and a risk of major complications up to 10%. Cardiac perforation following a catheter ablation is rare but serious complication and occurs in 1% of ventricular ablation procedures. The appropriate surgical repair may be challenging and need cardiopulmonary bypass support according to the location of the lesion and the hemodynamic status of the patient. We report the case of a free wall right ventricular perforation of the interventricular groove with cardiac tamponade following catheter ablation for recurrent ventricular tachycardia. Due to the proximity of the left anterior descending artery and the extreme fragility of tissues, the patient was treated successfully by a sutureless patch technique using a fibrin tissue-adhesive collagen fleece (TachoSil®). This technique is a safe and effective surgical option to repair a ventricular perforation especially when the ventricular tissues are fragile. It is simple and enable to realize surgical repair also if the localization of tear is difficult to access and without the need for cardiopulmonary bypass support if hemodynamic conditions are stable.

Experimental test of theories of the detection mechanism in a nanowire superconducting single photon detector

We report an experimental test of the photodetection mechanism in a nanowire superconducting single photon detector. Detector tomography allows us to explore the 0.8-8 eV energy range via multiphoton excitations. High accuracy results enable a detailed comparison of the experimental data with theories for the mechanism of photon detection. We show that the temperature dependence of the efficiency of the superconducting single photon detector is determined not by the critical current but by the current associated with vortex unbinding. We find that both quasiparticle diffusion and vortices play a role in the detection event.

Bioprospecting at former mining sites across Europe: microbial and functional diversity in soils

The planetary importance of microbial function requires urgently that our knowledge and our exploitation ability is extended, therefore every occasion of bioprospecting is welcome. In this work, bioprospecting is presented from the perspective of the UMBRELLA project, whose main goal was to develop an integral approach for remediation of soil influenced by mining activity, by using microorganisms in association with plants. Accordingly, this work relies on the cultivable fraction of microbial biodiversity, native to six mining sites across Europe, different for geographical, climatic and geochemical characteristics but similar for suffering from chronic stress. The comparative analysis of the soil functional diversity, resulting from the metabolic profiling at community level (BIOLOG ECOPlates) and confirmed by the multivariate analysis, separates the six soils in two clusters, identifying soils characterised by low functional diversity and low metabolic activity. The microbial biodiversity falls into four major bacterial phyla: Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes, including a total of 47 genera and 99 species. In each soil, despite harsh conditions, metabolic capacity of nitrogen fixation and plant growth promotion were quite widespread, and most of the strains showed multiple resistances to heavy metals. At species-level, Shannon's index (alpha diversity) and Sørensen's Similarity (beta diversity) indicates the sites are indeed diverse. Multivariate analysis of soil chemical factors and biodiversity identifies for each soil well-discriminating chemical factors and species, supporting the assumption that cultured biodiversity from the six mining sites presents, at phylum level, a convergence correlated to soil factors rather than to geographical factors while, at species level, reflects a remarkable local characterisation.

Mapping the 3D distribution of CdSe nanocrystals in highly oriented and nanostructured hybrid P3HT-CdSe films grown by directional epitaxial crystallization

Highly oriented and nanostructured hybrid thin films made of regioregular poly(3-hexylthiophene) and colloidal CdSe nanocrystals are prepared by a zone melting method using epitaxial growth on 1,3,5-trichlorobenzene oriented crystals. The structure of the films has been analyzed by X-ray diffraction using synchrotron radiation, electron diffraction and 3D electron tomography to afford a multi-scale structural and morphological description of the highly structured hybrid films. A quantitative analysis of the reconstructed volumes based on electron tomography is used to establish a 3D map of the distribution of the CdSe nanocrystals in the bulk of the films. In particular, the influence of the P3HT-CdSe ratio on the 3D structure of the hybrid layers has been analyzed. In all cases, a bi-layer structure was observed. It is made of a first layer of pure oriented semi-crystalline P3HT grown epitaxially on the TCB substrate and a second P3HT layer containing CdSe nanocrystals uniformly distributed in the amorphous interlamellar zones of the polymer. The thickness of the P3HT layer containing CdSe nanoparticles increases gradually with increasing content of NCs in the films. A growth model is proposed to explain this original transversal organization of CdSe NCs in the oriented matrix of P3HT.

Electromechanical tuning of vertically-coupled photonic crystal nanobeams

We present the design, the fabrication and the characterization of a tunable one-dimensional (1D) photonic crystal cavity (PCC) etched on two vertically-coupled GaAs nanobeams. A novel fabrication method which prevents their adhesion under capillary forces is introduced. We discuss a design to increase the flexibility of the structure and we demonstrate a large reversible and controllable electromechanical wavelength tuning (> 15 nm) of the cavity modes.

A quadruple mutant of Arabidopsis reveals a β-carotene hydroxylation activity for LUT1/CYP97C1 and a regulatory role of xanthophylls on determination of the PSI/PSII ratio

BACKGROUND

Xanthophylls are oxygenated carotenoids playing an essential role as structural components of the photosynthetic apparatus. Xanthophylls contribute to the assembly and stability of light-harvesting complex, to light absorbance and to photoprotection. The first step in xanthophyll biosynthesis from α- and β-carotene is the hydroxylation of ε- and β-rings, performed by both non-heme iron oxygenases (CHY1, CHY2) and P450 cytochromes (LUT1/CYP97C1, LUT5/CYP97A3). The Arabidopsis triple chy1chy2lut5 mutant is almost completely depleted in β-xanthophylls.

RESULTS

Here we report on the quadruple chy1chy2lut2lut5 mutant, additionally carrying the lut2 mutation (affecting lycopene ε-cyclase). This genotype lacks lutein and yet it shows a compensatory increase in β-xanthophylls with respect to chy1chy2lut5 mutant. Mutant plants show an even stronger photosensitivity than chy1chy2lut5, a complete lack of qE, the rapidly reversible component of non-photochemical quenching, and a peculiar organization of the pigment binding complexes into thylakoids. Biochemical analysis reveals that the chy1chy2lut2lut5 mutant is depleted in Lhcb subunits and is specifically affected in Photosystem I function, showing a deficiency in PSI-LHCI supercomplexes. Moreover, by analyzing a series of single, double, triple and quadruple Arabidopsis mutants in xanthophyll biosynthesis, we show a hitherto undescribed correlation between xanthophyll levels and the PSI-PSII ratio. The decrease in the xanthophyll/carotenoid ratio causes a proportional decrease in the LHCII and PSI core levels with respect to PSII.

CONCLUSIONS

The physiological and biochemical phenotype of the chy1chy2lut2lut5 mutant shows that (i) LUT1/CYP97C1 protein reveals a major β-carotene hydroxylase activity in vivo when depleted in its preferred substrate α-carotene; (ii) xanthophylls are needed for normal level of Photosystem I and LHCII accumulation.

Usefulness of ultrasounds in the management of breast phyllodes tumors

INTRODUCTION

Breast phyllodes tumors (PT) are uncommon fibroepithelial lesions having potential malignant features. These tumors have characteristic features, like pleomorphism, mitoses and overgrowth of the stroma with possible infiltrative margins. The clinical behaviour could be unpredictable, since the relatively high recurrence rate despite correct surgical strategy. Conventional diagnostic examinations show high sensitivity and specificity, but cannot demonstrate the differences between benign and malignant PT. MRI is not more effective.

PATIENTS AND METHODS

Sixteen patients affected by PT have been surgically treated at our Institution. All patients received mammography and ultrasonography (US) as preoperative diagnostic work-up.

RESULTS

in 13 patients, US was effective in preoperative diagnosis of PT. Mammography was uneffective in detecting breast lesions in 5 cases, while in 11 cases mammographic findings presented benign features, with a round opacity with moderate tissue density and well-defined wall.

CONCLUSION

US remains the most useful diagnostic test in detecting PT. However, there is no test effective in identifying malignat PT. In case of suspicion, fine needle biopsy should be performed.

Modified detector tomography technique applied to a superconducting multiphoton nanodetector

We present an experimental method to characterize multi-photon detectors with a small overall detection efficiency. We do this by separating the nonlinear action of the multiphoton detection event from linear losses in the detector. Such a characterization is a necessary step for quantum information protocols with single and multiphoton detectors and can provide quantitative information to understand the underlying physics of a given detector. This characterization is applied to a superconducting multiphoton nanodetector, consisting of an NbN nanowire with a bowtie-shaped subwavelength constriction. Depending on the bias current, this detector has regimes with single and multiphoton sensitivity. We present the first full experimental characterization of such a detector.

A time bomb in the thorax: the giant ascending aortic aneurysm: case report

We report the case of a 82-year-old woman, asymptomatic, subject to chest computed tomography for trauma. Then the patient underwent surgery. Before sternotomy, femoro-femoral bypass was starter in order to decompress the aneurysm; using deep hypothermia and circulatory arrest, ascending aorta and hemiarch replacement were performed with a Dacron graft. Post-operative course was uneventful.