Oxathiazinane derivatives display both antineoplastic and antibacterial activity: a structure activity study.

PURPOSE: The Oxathiazinane substance class is characterized by a high diversity of chemical structures yet to be fully investigated. Our research group recently proved that the 1.4.5-oxathiazine-4.4-dioxide, known as substance GP-2250, possesses antineoplastic properties as shown on pancreatic carcinoma. This current study aims to gain insights into the structure and activity relationship of a series of different Oxathiazinanes regarding their antineoplastic activity and the potential correlation with antibacterial activity. We investigated the newly synthesized Oxathiazinane derivatives: 2255, 2256, 2287, 2289, 2293 and 2296 in comparison to GP-2250. METHODS: The antineoplastic effect was evaluated in different cancer entities (breast, skin, pancreas and colon cancer cell lines) by viability, proliferation, and cell migration assays in vitro. Disc diffusion tests were performed on various bacteria strains to examine the antibacterial potential. Additionally, reactive oxygen species (ROS) assays were conducted to investigate mechanistic aspects. RESULTS: The substances GP-2250, 2293, 2289 and 2296 not only showed antineoplastic activity in four different cancer entities but also antibacterial effects, as tested on multiple bacteria strains including MRSA (Methicillin-resistant Staphylococcus aureus). Furthermore, these substances also induced high ROS levels up to 110% in the treated cancer cell lines compared to untreated control cells. These results indicate a correlation between an antineoplastic capacity and antibacterial properties of these derivatives. Both activities appear to be ROS driven. The Oxathiazinane derivatives 2255, 2256 and 2287 lacked both, antineoplastic and antibacterial activity. CONCLUSION: Thus, a comparable structure activity relationship became apparent for both the antineoplastic and antibacterial activity.

Rapid plant trait evolution can alter coastal wetland resilience to sea level rise.

Rapid evolution remains a largely unrecognized factor in models that forecast the fate of ecosystems under scenarios of global change. In this work, we quantified the roles of heritable variation in plant traits and of trait evolution in explaining variability in forecasts of the state of coastal wetland ecosystems. A common garden study of genotypes of the dominant sedge Schoenoplectus americanus, "resurrected" from time-stratified seed banks, revealed that heritable variation and evolution explained key ecosystem attributes such as the allocation and distribution of belowground biomass. Incorporating heritable trait variation and evolution into an ecosystem model altered predictions of carbon accumulation and soil surface accretion (a determinant of marsh resilience to sea level rise), demonstrating the importance of accounting for evolutionary processes when forecasting ecosystem dynamics.

Wire-frame integrity of patch-like Gore devices following atrial septal defect closure.

OBJECTIVES: To assess the structural integrity of the patch-like Gore Septal Occluder (GSO) used for device closure of secundum-type atrial septal defects (ASD II) in pediatric patients. BACKGROUND: GSO has shown to be effective and safe for ASD device closure in children and adolescents. METHODS: Single-center, retrospective mid- to long-term follow-up of all children and adolescents with a GSO in situ (≥12 months). Periprocedural data and follow-up data were evaluated, including chest X-rays to assess the GSO's wire-frame morphology. RESULTS: Ninety-one consecutive patients were enrolled with a median age and weight of 5 years (range 2-18) and 20 kg (range 11-95) at implantation. ASD anatomy included 64 single and 27 multi-fenestrated defects, with 39 patients having small retro-aortic rims (≤4 mm). Median follow-up period was 42.5 months (range 12-74). Chest X-rays were available in 80 children: in 74 of them, the GSO's visualization on X-ray enabled us to reliably assess the wire-frame structure. Wire-frame fracture (WFF) was ultimately detected in five of the 74 patients (6.8%); however, those occluders appeared stably anchored and well aligned to both sides of the septum, and no free wire fragments had escaped the GSO matrix. Thus, no further treatment was required. CONCLUSIONS: Our data confirm that the GSO is safe and effective for ASD closure. Despite its lightweight construction, the GSO seems to offer reliable mechanical durability. Wire-frame fractures occur, but the free wire-ends appear to have remained stable within the GSO matrix without any clinical sequelae so far.

Innovative substance 2250 as a highly promising anti-neoplastic agent in malignant pancreatic carcinoma - in vitro and in vivo.

BACKGROUND: Former studies already revealed the anti-neoplastic properties of the anti-infective agent Taurolidine (TRD) against many tumor species in vitro and in vivo. Its anti-proliferative and cell death inducing capacity is largely due to its main derivative Taurultam (TRLT). In this study it could be demonstrated, that substance 2250 - a newly defined innovative structural analogue of TRLT - exhibits an anti-neoplastic effect on malignant pancreatic carcinoma in vitro and in vivo. METHODS: The anti-neoplastic potential of substance 2250 as well as its mode of action was demonstrated in extensive in vitro analysis, followed by successful and effective in vivo testings, using xenograft models derived from established pancreatic cancer cell lines as well as patient derived tissue. RESULTS: Our functional analysis regarding the role of oxidative stress (ROS) and caspase activated apoptosis showed, that ROS driven programmed cell death (PCD) is the major mechanisms induced by substance 2250 in pancreatic carcinoma. What is strongly relevant towards clinical practice is especially the observed inhibition of patient derived pancreatic cancer tumor growth in mice treated with this new substance in combination with its sharply higher metabolic stability. CONCLUSION: These encouraging results provide new therapeutical opportunities in pancreatic cancer treatment and build the basis for further functional analysis as well as first clinical studies for this promising agent.

Cardiac thrombus with risk of fulminant pulmonary embolism in paediatric antiphospholipid syndrome.

Antiphospholipid Syndrome (APS) describes a systemic disease caused by autoantibodies to membrane components. Involving coagulation pathways, complement factors and immune cells, it results in thrombosis in any blood vessel. Its clinical presentation varies considerably depending upon the organ affected. Paediatric data on APS remain sparse. Most case reports focus on catastrophic APS with multiple small-vessel occlusions and a life-threatening course. Here, we report on a 15-year-old patient with deep vein thrombosis and a right ventricular tumour posing the risk of a fulminant pulmonary embolism. The tumour was surgically removed. Histology revealed it to be a thrombus. The patient fully recovered and is currently treated with long term anticoagulation.

Bronchial compression following pulmonary artery stenting in single ventricle lesions: how to prevent, and how to decompress.

OBJECTIVES: To assess airway compression during pulmonary artery (PA) intervention in single ventricle (SV) palliation. BACKGROUND: SV lesions with a prominent neo-aortic root are considered a high risk for branch PA and/or bronchial stenosis. PA stenting is well established, but may result in ipsilateral bronchial compression. METHODS: Single-centre retrospective analysis of 19 palliated SV patients with branch PA stenosis and close proximity to the ipsilateral main bronchus who underwent cardiac catheterisation at a median age and weight of 8.5 years (0.5-25) and 16.5 kg (6-82) between 12/2011 and 05/2015. RESULTS: Two of the 19 patients suffered an almost-closed left-main bronchus (LMB) following PA stenting. Fortunately, LMB decompression succeeded in both those patients by re-shaping the PA stents by compressing the chest while splinting the LMB with an inflated balloon. To prevent the other 17 patients from suffering this serious complication, we adopted a thorough preparation strategy: 13 patients underwent safe simultaneous bronchoscopy and cardiac catheterisation; in the remaining 4 patients CT-angiography enabled accurate risk evaluation prior to re-catheterisation. CONCLUSIONS: In SV lesions accompanied by branch PA stenosis, thorough preparation via cross-sectional imaging is mandatory, including simultaneous bronchoscopy and cardiac catheterisation in selected cases, to rule out any airway compression before considering endovascular stent implantation. If a PA stent's compression has already caused severe bronchial obstruction, our balloon-splinted decompression technique should be considered.

Transcatheter device occlusion of the left ventricular outflow tract as treatment for severe aortic regurgitation in hypoplastic left heart syndrome.

Aortic regurgitation is a rare but dangerous condition in patients with hypoplastic left heart syndrome (HLHS). We report the case of a 2-year-old girl with HLHS with aortic/mitral stenosis (AS-MS) subtype after stage II palliation via the bilateral bidirectional Glenn (BBDG) procedure, when aortic regurgitation presented with the clinical manifestation of a paroxysmal coronary steal phenomenon provoked by exertion. Transcatheter closure of the left ventricular outflow tract (LVOT) with an Amplatzer(TM) Vascular Plug 4 minimized and finally abolished aortic reflux without compromising either coronary perfusion or atrioventricular (AV) conduction. Midterm follow-up over 3 years revealed complete disappearance of her symptoms, and follow-up catheterization displayed complete LVOT closure. This case illustrates the promising potential of modern cardiac catherization techniques in certain cases and emphasizes that precise assessment of the native aorta and coronary system is critical in HLHS patients.

Transcatheter closure of atrial septal defects in children and adolescents: single-center experience with the GORE® septal occluder.

OBJECTIVES: Device closure of atrial septal defects (ASD II) is an alternative to surgery. ASD morphology and intracardiac relationships may influence device selection. Biocompatibility, techniques for closing large or multiple defects, and the risk of erosion are main issues in children BACKGROUND: The GORE® Septal Occluder (GSO) is a non-self-centering device with a flat and conformable nitinol-frame covered with expanded polytetrafluoroethylene. We hereby evaluate our initial experience in children to demonstrate feasibility, efficacy, and safety. METHODS: Single-center retrospective intention-to-treat analysis of GSO procedures in children and adolescents with hemodynamically significant ASD. All procedures were conducted under general anesthesia, fluoroscopy and transesophageal echocardiography. All defects were sized using stop-flow-technique. GSOs of 20-30 mm disc-diameter were implanted. RESULTS: GSO implantation was attempted in 45 with technical success in 41 patients, median age 6 (range 3-17) years, bodyweight 19 (12-95) kg. Median balloon-sized diameter was 13 (8-19) mm resulting in a GSO-to-ASD-ratio of 2 (1.7-2.5). Deficient retro-aortic rims (<3 mm) were found in 12 patients, and 10 of these 12 defects could be closed. We observed no complications. Four extensive or multiple ASDs were not treated successfully with GSO. After retrieval, one was closed with a different device; three patients needed surgical therapy. The median follow-up of four (range 0.2-22) months was uneventful in all patients CONCLUSIONS: We found the GSO device closure of ASDs in children to be effective. However, our initial experience is limited to short- and mid-term-follow-up of a low number of patients.

Phase regeneration of a star-8QAM signal in a phase-sensitive amplifier with conjugated pumps.

We demonstrate numerically phase regeneration of a star-8QAM signal with two amplitude and four phase states in a phase-sensitive amplifier. In a dual-stage setup, two phase-conjugated idlers are generated in a first stage consisting of two fiber-optic parametric phase-insensitive amplifiers operated in highly nonlinear gain regime. These are used as pumps in the second, phase-sensitive amplification stage which enables efficient phase regeneration via a degenerate four-wave-mixing process. The latter can be operated in two different operation modes: without format conversion or with phase-shifted amplitude levels. In both regimes, we observe high phase-regeneration efficiency for all amplitude levels: the initial phase noise with 0.2 rad standard deviation is reduced by a factor of 5.

Electrical impedance tomography for verification of correct endotracheal tube placement in paediatric patients: a feasibility study.

BACKGROUND: Endotracheal tubes (ETTs) are frequently used in paediatric anaesthesia. Correct placement is crucial. The aim of this study was to evaluate electrical impedance tomography (EIT) for guiding and confirmation of paediatric ETT placement. In a retrospective analysis of stored EIT data, distribution of ventilation between left and right lung was used to verify correct paediatric ETT placement. METHODS: Left and right lung ventilation was studied by EIT in 18 paediatric patients (median age: 53 months) requiring anaesthesia and endotracheal intubation. EIT was recorded before induction of anaesthesia, during mask ventilation, during ETT placement (including deliberate mainstem intubation), and after ETT repositioning according to the formula: ETT intubation depth (cm) = 3× ETT internal diameter (mm) or the mainstem intubation method (withdrawing the ETT 2 cm). Final ETT position was confirmed by fluoroscopy. RESULTS: Following deliberate mainstem intubation, distribution of ventilation to the right lung was unequivocally demonstrated by EIT. Homogeneous distribution of ventilation between left and right lung monitored with EIT correlated in each patient with correct endotracheal ETT placement. The distribution of left and right lung ventilation differed significantly (P < 0.05) between the initial two-lung ventilation and subsequent right one-lung ventilation, and between right one-lung and subsequent two-lung ventilation according to auscultation and the final ETT position, respectively. In one patient, ETT was misplaced within the oesophagus which was also obvious from the EIT record. CONCLUSION: This study demonstrates that EIT enables non-invasive recognition of correct ETT placement. Homogeneous right-left-lung ventilation is an indicator for correct ETT placement.

The development and validation of a health-related quality of life questionnaire for pre-school children with a chronic heart disease.

PURPOSE: Heart diseases are often associated with residual injuries, persisting functional restrictions, and long-term sequelae for psychosocial development. Currently, there are no disease-specific instruments to assess the health-related quality of life (HrQoL) of pre-school children. The aims of this study were to develop a parent proxy instrument to measure the HrQoL of children aged 3-7 years with a heart disease and to confirm its validity and reliability. METHODS: Items from the Preschool Pediatric Cardiac Quality of Life Inventory (P-PCQLI) were generated through focus groups of caregivers. In a pilot study, comprehensibility and feasibility were tested. Five subdimensions were defined theoretically. Psychometric properties were analysed within a multicentre study with 167 parental caregivers. RESULTS: The final 52-item instrument contains a total score covering five moderately inter-correlated dimensions. The total score of the questionnaire showed a very high internal consistency (Cronbachs' α = 0.95). Test-retest correlation was at r tt = 0.96. External validity was indicated by higher correlations (r = 0.24-0.68) with a generic paediatric quality of life questionnaire (KINDL) compared to the Strengths and Difficulties Questionnaire (r = 0.17 to 0.59). Low P-PCQLI total scores were significantly associated with inpatient as opposed to outpatient treatment (t = 6.04, p < .001), with at least moderate disease severity ((t = 5.05, p < .001) NYHA classification) and with poorer prognosis (t = 5.53, p < .001) as estimated by the physician. CONCLUSIONS: The P-PCQLI is reliable and valid for pre-school children with a heart disease. It could be used as a screening instrument in routine care, and for evaluation of HrQoL outcomes in clinical trials and intervention research.

Demonstration of polarization pulling using a fiber-optic parametric amplifier.

We report the observation of all-optical polarization pulling of an initially polarization-scrambled signal using parametric amplification in a highly nonlinear optical fiber. Broadband polarization pulling has been achieved both for the signal and idler waves with up to 25 dB gain using the strong polarization sensitivity of parametric amplifiers. We further derive the probability distribution function for the final polarization state, assuming a randomly polarized initial state, and we show that it agrees well with the experiments.

Black-light continuum generation in a silica-core photonic crystal fiber.

We report the observation of a broadband continuum spanning from 350 to 470 nm in the black-light region of the electromagnetic spectrum as a result of picosecond pumping a solid-core silica photonic crystal fiber at 355 nm. This was achieved despite strong absorption and a large normal dispersion of silica glass in the UV. Further investigations reveal that the continuum generation results from the interplay of intermodally phase-matched four-wave mixing and cascaded Raman scattering. We also discuss the main limitations in terms of bandwidth and power due to temporal walk-off, fiber absorption, and the photo darkening effect, and we suggest simple solutions.

Prophylactic use of clopidogrel in paediatric cardiac patients.

Thromboembolic complications in infants with congenital heart defects are common despite inhibition of platelet function with acetylsalicylic acid (ASS). Yet there is still insufficient pharmacologic data on the use of clopidogrel in infants. The adult dose of 75 mg/d is significantly higher than the dose lately recommended in infants (0.2 mg/kg/d). Moreover, we know of nonresponders to both acetylsalicylic acid and clopidogrel. Normal coagulation tests fail to identify those patients.Prospective monocentric study on 14 children (median age 5, range 0.7-84 months, 9 male, 5 female). Shunt thrombosis had occurred in 4 infants on ASS therapy. Seven days after starting clopidogrel (0.2 mg/kg/d), platelet function was tested by stimulation with ADP (4 and 10 µmol/l). We considered the range for the clopidogrel effect to be optimal if the maximum aggregation on ADP 4 µmol/l was between 30-50%.Clopidogrel 0.18-0.24 mg/kg/d in addition to ASS 2-4 mg/kg/d resulted in effective inhibition of platelet function in 93% (ADP 4 µmol/l: median 38%, range 30-63). All patients were responders. We observed neither any thromboembolic events nor severe bleeding episodes during the median 11-month follow-up period (range 1-30 mo).Testing platelet function makes clopidogrel dosing safer, and simplifies therapy adjustments in long-term treatment. A clopidogrel dose of 0.2 mg/kg/d was safe and effective in combination with ASS in this small patient cohort.

4D-MR flow analysis in patients after repair for tetralogy of Fallot.

OBJECTIVES: Comprehensive analysis of haemodynamics by 3D flow visualisation and retrospective flow quantification in patients after repair of tetralogy of Fallot (TOF). METHODS: Time-resolved flow-sensitive 4D MRI (spatial resolution ~ 2.5 mm, temporal resolution = 38.4 ms) was acquired in ten patients after repair of TOF and in four healthy controls. Data analysis included the evaluation of haemodynamics in the aorta, the pulmonary trunk (TP) and left (lPA) and right (rPA) pulmonary arteries by 3D blood flow visualisation using particle traces, and quantitative measurements of flow velocity. RESULTS: 3D visualisation of whole heart haemodynamics provided a comprehensive overview on flow pattern changes in TOF patients, mainly alterations in flow velocity, retrograde flow and pathological vortices. There was consistently higher blood flow in the rPA of the patients (rPA/lPA flow ratio: 2.6 ± 2.5 vs. 1.1 ± 0.1 in controls). Systolic peak velocity in the TP was higher in patients (1.9 m/s ± 0.7 m/s) than controls (0.9 m/s ± 0.1 m/s). CONCLUSIONS: 4D flow-sensitive MRI permits the comprehensive evaluation of blood flow characteristics in patients after repair of TOF. Altered flow patterns for different surgical techniques in the small patient cohort may indicate its value for patient monitoring and potentially identifying optimal surgical strategies.

Iatrogenic neonatal type B aortic dissection: comprehensive MRI-based diagnosis and follow-up.

Neonatal aortic dissection is rare and most frequently iatrogenic. Decision making and appropriate imaging are highly challenging for pediatric cardiologists and radiologists. We present MRI and echocardiographic findings in the follow-up at 6 months of age of a boy with a conservatively treated iatrogenic neonatal aortic dissection (type B). To evaluate the morphology of the aortic arch and descending aorta, we carried out multidirectional time-resolved three-dimensional flow-analysis and contrast-enhanced MR angiography (CE-MRA). The MRI and Doppler echocardiographic results were closely comparable. Three-dimensional visualization helped assess details of blood flow acceleration and alteration caused by the dissection, and played a key role in our deciding not to treat surgically.

Frequency-selective excitation of guided acoustic modes in a photonic crystal fiber.

We present experimental and numerical results demonstrating the simultaneous frequency-selective excitation of several guided acoustic Brillouin modes in a photonic crystal fiber with a multi-scale structure design. These guided acoustic modes are identified by using a full vector finite-element model to result from elastic radial vibrations confined by the wavelength-scale air-silica microstructure. We further show the strong impact of structural irregularities of the fiber on the frequency and modal shape of these acoustic resonances.

Photonic crystal fiber mapping using Brillouin echoes distributed sensing.

In this paper we investigate the effect of microstructure irregularities and applied strain on backward Brillouin scattering by comparing two photonic crystal fibers drawn with different parameters in order to minimize diameter and microstructure fluctuations. We fully characterize their Brillouin properties including the gain spectrum and the critical power. Using Brillouin echoes distributed sensing with a high spatial resolution of 30 cm we are able to map the Brillouin frequency shift along the fiber and get an accurate estimation of the microstructure longitudinal fluctuations. Our results reveal a clear-cut difference of longitudinal homogeneity between the two fibers.

Lepirudin treatment in a boy with suspected HIT II after surgery because of tetralogy of Fallot.

UNLABELLED: Heparin-induced thrombocytopenia (HIT II) in childhood is rare. Suspected HIT II requires immediate diagnostic and therapeutic measures in order to avoid potentially life threatening complications. Heparin must be stopped immediately. We report on a 6-year old boy who required cardiac surgery due to tetralogy of Fallot. To our knowledge he had been exposed to heparin for the first time during cardiac catheterization on the day before surgery. Preoperatively, platelet count was normal. Postoperatively (3 days after heparin exposure), he developed pulmonary and renal failure and required inotropic cardiac support and dialysis. He also developed progressive (severe) thrombocytopenia under heparin therapy on day 2-3 postoperatively. The dialysis filter required daily exchanges due to clotting despite increasing heparin doses. The first ELISA for HIT on postop day 4 was negative. 3 days later a repeated test was positive. Von Willebrand factor antigen and D-dimers were markedly increased. The patient was immediately switched to lepirudin and subsequently stabilized slowly. No major systemic thrombosis occurred. After lepirudin treatment for 6 weeks the patient was fully recovered and HIT II-testing was negative again. CONCLUSION: In children with progressive thrombocytopenia in the setting of heparin exposure and signs of major or micro thrombosis HIT II must be ruled out. Even if a first early test turns out negative repeated testing should be performed. Lepirudin anticoagulation is effective and should be monitored correctly. Platelet transfusion should be avoided in HITII.