Evaluation of a modified paediatric early warning score for children with congenital heart disease

BACKGROUND

Paediatric early warning score systems are used for early detection of clinical deterioration of patients in paediatric wards. Several paediatric early warning scores have been developed, but most of them are not suitable for children with cyanotic CHD who are adapted to lower arterial oxygen saturation.

AIM

The present study compared the original paediatric early warning system of the Royal College of Physicians of Ireland with a modification for children with cyanotic CHD.

DESIGN

Retrospective single-centre study in a paediatric cardiology intermediate care unit at a German university hospital.

RESULTS

The distribution of recorded values showed a significant shift towards higher score values in patients with cyanotic CHD (p < 0.001) using the original score, but not with the modification. An analysis of sensitivity and specificity for the factor "requirement of action" showed an area under the receiver operating characteristic for non-cyanotic patients of 0.908 (95% CI 0.862-0.954). For patients with cyanotic CHD, using the original score, the area under the receiver operating characteristic was reduced to 0.731 (95% CI 0.637-0.824, p = 0.001) compared to 0.862 (95% CI 0.809-0.915, p = 0.207), when the modified score was used. Using the critical threshold of scores ≥ 4 in patients with cyanotic CHD, sensitivity and specificity for the modified score was higher than for the original (sensitivity 78.8 versus 72.7%, specificity 78.2 versus 58.4%).

CONCLUSION

The modified score is a uniform scoring system for identifying clinical deterioration, which can be used in children with and without cyanotic CHD.

Nalbuphine as analgesic in preschool children undergoing ophthalmic surgery and the occurrence of emergence delirium

BACKGROUND/AIMS

Perioperative pain in children is often inadequately treated, and emergence agitation is common. The purpose of this analysis was to determine whether nalbuphine is suitable for perioperative eye pain and to analyse if it influences the occurrence of emergence delirium/agitation (EDA) in children undergoing ophthalmic surgery in general anaesthesia.

METHODS

Retrospective cohort analysis of 50 children in preschool age undergoing general anaesthesia for ophthalmic surgery receiving nalbuphine as a postoperative analgesic in a German university hospital from June 2020 to February 2021.Scores and values for pain and EDA were routinely recorded after awakening and during the stay in the recovery room. Data were evaluated retrospectively from the medical records.

RESULTS

A total of 50 children (17 girls and 33 boys) underwent general anaesthesia for ophthalmic surgery. The median age of the children included was 20.5 months (range, 1-68 months), the median body weight was 12.25 kg (range, 2.9-29 kg). All patients received ibuprofen (10 mg/kg1) during induction of anaesthesia and nalbuphine (0.1 mg/kg) at the end of surgery. All patients had an Paediatric-Anaesthesia-Emergence-Delirium-I-score (PAED-ED-I Score) of less than 6 and acceptable Face-Legs-Activity-Cry-Consolability-scores (FLACC less than 3) on waking and on leaving the recovery room.

CONCLUSION

Nalbuphine shows a sufficient analgesic effect for pain therapy following ophthalmic surgery in preschool children. Nalbuphine seems to reduce the incidence of EDA in children undergoing ophthalmic surgery.

Human metapneumovirus infection in the cardiac paediatric ICU before and during COVID-19 pandemic: a retrospective cohort analysis

INTRODUCTION

This study investigates the hygiene standards in the context of the COVID-19 pandemic and their impact on the perioperative incidence of human metapneumovirus as well as the typical symptom burden of human metapneumovirus-infected children with CHDs.

MATERIALS AND METHODS

Between March 2018 and July 2021, all patients of a cardiac paediatric ICU of a German university hospital were included in this retrospective cohort analysis.

RESULTS

A total of 589 patients with CHD were included in the analysis. Three hundred and fifty-two patients (148 females and 204 males) were admitted before the introduction of social distancing and face masks between March 2018 and 15 April 2020 (cohort A). Two hundred and thirty-seven patients (118 females and 119 males) were admitted after the introduction between April 16 and July 2021 (cohort B). In cohort A, human metapneumovirus was detected in 11 out of 352 patients (3.1%) during their stay at cardiac paediatric ICU. In cohort B, one patient out of 237 (0.4%) tested positive for human metapneumovirus. Patients who tested positive for human metapneumovirus stayed in cardiac paediatric ICU for a median of 17.5 days (range, 2-45 days). Patients without a detected human metapneumovirus infection stayed in the cardiac paediatric ICU for a median of 4 days (range, 0.5-114 days). Nine out of 12 (75%) human metapneumovirus-positive patients showed atelectasis.

CONCLUSION

Perioperative human metapneumovirus infections prolong cardiac paediatric ICU stay in children with CHD. In affected patients, pulmonary impairment with typical symptoms appears. Under certain circumstances, a complication-rich perioperative infection with human metapneumovirus could be prevented in paediatric cardiac high-risk patients by prophylactic hygiene intervention.

3D-printed facet-attached optical elements for beam shaping in optical phased arrays

We demonstrate an optical phased-array equipped with a 3D-printed facet-attached element for shaping and deflection of the emitted beam. The beam shaper combines freeform refractive surfaces with total-internal-reflection mirrors and is in-situ printed to edge-emitting waveguide facets using high-resolution multi-photon lithography, thereby ensuring precise alignment with respect to on-chip waveguide structures. In a proof-of-concept experiment, we achieve a grating-lobe free steering range of ±30^∘ and a full-width-half-maximum beam divergence of approximately 2^∘. The concept opens an attractive alternative to currently used grating structures and is applicable to a wide range of integration platforms.

Dexmedetomidine as a sole sedative for procedural sedation in preterm and neonate infants: A retrospective analysis

BACKGROUND

Many different sedation concepts for magnetic resonance imaging have been described for prematurely and term-born infants, ranging from "no sedation" to general anesthesia. Dexmedetomidine is an alpha-2 receptor agonist that is frequently used to sedate older children, because the anesthesiologist can easily adjust sedation depth, the patient maintains spontaneous breathing, and awakens rapidly afterwards.

AIMS

The present study evaluates whether dexmedetomidine could safely be used as the sole sedative for prematurely and term-born infants less than 60 weeks postconceptional age undergoing diagnostic procedures.

METHODS

We performed a retrospective monocentric analysis of n = 39 prematurely and term-born infants (<60 weeks postconceptional age or a body weight <5 kg) who were sedated with dexmedetomidine for an MRI at a German university hospital from August 2016 to November 2018.

RESULTS

Successful imaging was achieved in all cases. The median initial bolus of dexmedetomidine administered over 10 min was 1.39 μg kg^-1 body weight (range 0.34-3.64 μg kg^-1 ), followed with a continuous infusion at a median rate of 1.00 μg kg^-1  h^-1 (range 0.5-3.5 μg kg^-1  h^-1 ); however, 3 patients (7%) needed some additional sedation (ketamine or propofol). All patients, including 10 infants who had previously required respiratory support, underwent the procedure without any relevant desaturation or apnea. Bradycardia was observed in up to 15 out of 39 cases (38.5%), but only four (10.3% in total and 26.7% of bradycardia) required atropine.

CONCLUSIONS

These results indicate that dexmedetomidine can be safely used for procedural sedation in the high-risk cohort of prematurely and term-born infants less than 60 weeks postconceptional age. Apnea during procedural sedation and subsequent stay in the recovery room is avoided, but bradycardia remains a relevant risk that may require treatment.

Impact of Lactate Clearance on Early Outcomes in Pediatric ECMO Patients

Background and Objectives: Pediatric extracorporeal membrane oxygenation (ECMO) support is often the ultimate therapy for neonatal and pediatric patients with congenital heart defects after cardiac surgery. The impact of lactate clearance in pediatric patients during ECMO therapy on outcomes has been analyzed. Materials andMethods: We retrospectively analyzed data from 41 pediatric vaECMO patients between January 2006 and December 2016. Blood lactate and lactate clearance have been recorded prior to ECMO implantation and 3, 6, 9 and 12 h after ECMO start. Receiver operating characteristic (ROC) analysis was used to identify cut-off levels for lactate clearance. Results: Lactate levels prior to ECMO therapy (9.8 mmol/L vs. 13.5 mmol/L; p = 0.07) and peak lactate levels during ECMO support (10.4 mmol/L vs. 14.7 mmol/L; p = 0.07) were similar between survivors and nonsurvivors. Areas under the curve (AUC) of lactate clearance at 3, 9 h and 12 h after ECMO start were significantly predictive for mortality (p = 0.017, p = 0.049 and p = 0.006, respectively). Cut-off values of lactate clearance were 3.8%, 51% and 56%. Duration of ECMO support and respiratory ventilation was significantly longer in survivors than in nonsurvivors (p = 0.01 and p < 0.001, respectively). Conclusions: Dynamic recording of lactate clearance after ECMO start is a valuable tool to assess outcomes and effectiveness of ECMO application. Poor lactate clearance during ECMO therapy in pediatric patients is a significant marker for higher mortality.

Severe Hyponatraemia Associated with the Use of Arginine-Vasopressin in Two Neonates with Complex Congenital Heart Disease

We report two cases of neonates with complex congenital heart disease and volume, catecholamine, and corticosteroid refractory shock treated with arginine-vasopressin. Arginine-vasopressin was able to reverse critical hypotension, but both patients developed severe hyponatremia, which recovered after discontinuation of arginine-vasopressin. Close control and prompt substitution of serum sodium is required in neonates with advanced heart failure on high-dose vasopressin therapy.

Evaluation of Cerebral Vasoreactivity by SPECT and Transcranial Doppler Sonography using the Acetazolamide Test

Bei 29 Patienten (3 Kontrollpersonen, 26 Patienten mit zerebrovaskulärer Erkrankung) wurde prospektiv die Hirn-SPECT mit 99mTC-HMPAO und bei 20 Patienten (3 Kontrollpersonen, 17 Patienten mit ZVK) die transkranielle Dopplersonographie (TCD) vor und nach i. v. Gabe von Azetazolamid durchgeführt. Die Sensitivität der Hirn-SPECT erhöhte sich mit Azetazolamid von 62% auf 77%. Bei Patienten mit reversiblem neurologischem Defizit wurde eine Verbesserung von 50% auf 71 %, bei Patienten mit persistierendem Defizit von 75% auf 83% beobachtet. Die Ergebnisse der Hirn-SPECT und der TCD stimmten in der Beurteilung der zerebro-vaskulären Reservekapazität in 91% der Hemisphären überein. Die Korrelation zwischen den beiden Methoden war statistisch signifikant.

HMPAO-SPECT bei Demenz vom Alzheimer-Typ und Major Depression mit mnestischen Störungen

Ziel der vorliegenden Untersuchung war es, zu prüfen, ob die HMPAO-SPECT zur Differenzierung zwischen der Demenz vom Alzheimer-Typ (DAT) und der Major Depression (MD) beitragen kann. Es wurden ECT-Befunde von 77 Patienten mit Gedächtnisstörungen beurteilt, davon hatten 48 eine DAT und 29 eine MD. Zunächst wurden die Defekte in der SPECT einer Hirn-Region zugeordnet und der Grad der Ausprägung (-1/-2/-3) bewertet. Anschließend wurden die einzelnen Befunde in eine von 7 Befundkategorien eingeordnet. In einigen dieser 7 Gruppen ergaben sich deutliche Häufungen der Fälle mit DAT bzw. MD. 35% aller DAT-Patienten wiesen bilaterale Defekte mit deutlicher (>-1) parietaler/parietotemporaler Minderperfusion auf, dagegen zeigte kein Patient mit MD dieses Muster. Unilaterale Defekte wiesen 62% der MD-, aber nur 31% der DAT-Patienten auf. Die Untersuchung zeigt, daß nur 35% der Patienten mit DAT das bislang als »pathognomonisch« bezeichnete Befundmuster aufwiesen. Dieses Perfusionsmuster kann aber - wenn es vorliegt - als sicheres Kriterium zur Abgrenzung gegen eine MD gewertet werden. Darüber hinaus lassen sich keine eindeutigen (»krankheitstypischen«) Perfusionsmuster erkennen, wenngleich unilaterale Defekte mehr auf eine MD hindeuten.

99mTc-MAA-Anreicherung in der Leber bei cavo-portalem Shunt über eine rekanalisierte Vena umbilicalis

Bei der Lungenperfusionsszintigraphie einer Patientin mit Vena-cava-superior-Verschluß fand sich eine deutliche MAA-Anreicherung in Teilen der Leber. Als Ursache konnte ein Kollateralkreislauf über Venen der Abdominalwand und eine rekanalisierte Vena umbilicalis ermittelt werden. Unter externer Bestrahlung von Lymphomen des oberen Mediastinums kam es zu einem raschen Rückgang des cavo-portalen Shunt-Volumens.

Lymphoscintigraphy in breast cancer patients –comparison of peritumoural and intradermal injection

Aim of this study was to determine whether the sentinel lymph nodes (SLNs) can be accurately identified in breast cancer patients with intradermal injection of the radiotracer above the primary tumour in comparison to peritumoural injection. Methods: In 45 women with breast cancer we performed lymphoscintigraphy on two separate days. We injected Tc-99m nanocolloid on the first day peritumourally, and on a separate day intradermally. The results of both investigations using different injection sites were compared in order to determine the number and location of SLNs. Results: The SLN identification rate using peritumoural injection was 71% (32 of 45 patients) and 96% (43 out of 45 patients) using intradermal injection. In 62% (28 of 45 patients) the number and location of the SLNs were identical. In 97% (31 of 32 patients) in whom a SLN was detected using peritumoural injection, the same SLNs reappeared with intradermal injection. There were no false negative findings with the peritumoural administration of tracer whereas the intradermal administration approach resulted in a false negative rate of 13%. Conclusion: In women with breast cancer the reproducibility of lymphoscintigraphy using peritumoural and intradermal injection sites was 62%. The intradermal injection modality enables the detection of a SLN in patients where the peritumoural injection failed but it has the disadvantage of a higher false negative rate in comparison to the peritumoural injection technique.

Residual kidney function after donor nephrectomy

Aim: We evaluated the long-term residual renal function after donor nephrectomy using 99mTc-mercaptoacetyltriglycin (MAG3)-clearance. Donors, methods: Altogether 49 kidney donors were examined using 99mTc-MAG3-clearance after nephrectomy for donation to a relative (m:f = 11:38; age 55±27 years). The donors were examined 16±8 years postoperatively (1.5-26 years). 42 donors (86%) showed normal creatinine values, whereas the other seven (14%) exhibited slightly elevated levels. 20 donors were examined pre- and postoperatively and compared intraindividually. The kidney function was compared to the age adapted normal values of healthy persons with two kidneys (67–133% of age related mean). Results: After nephrectomy all donors showed a normal perfusion, good secretion, merely physiological intrarenal transit and a normal elimination from the kidneys. The 99mTc-MAG3-clearance was 69 ±15% of the normal mean value of healthy carriers of two kidneys regardless of the gender. 20 donors with a preoperative examination showed a significantly reduced total renal function from 84 ± 15% of the mean normal value preoperatively to 60 ± 15% postoperatively (p <0.0005). 15 donors of this group exhibited a significant functional increase of the residual kidney from 40% initially to 60% after nephrectomy (p = 0.003). No correlation was found between the initial 99mTc-MAG3-clearance measured prior to nephrectomy and the clearance levels after nephrectomy. Also, no correlation between the preoperative 99mTc- MAG3-clearance and the postoperative serum creatinine values could be observed. Altogether, 22% of the donors (11/49) developed arterial hypertension 10 ± 8 years after donation (1-23 years). This corresponds to the normal age prevalence of hypertension in the carriers of two kidneys. Three donors suffered from arterial hypertension prior to the operation. Conclusion: Kidney donors with normal or slightly elevated creatinine values postoperatively show a 99mTc- MAG3-clearance value of 69% of the mean value of healthy carriers of two kidneys. This may serve as a reference value for healthy carriers of one kidney. In our study we demonstrated a good compensation of the contralateral kidney via renal scintigraphy by means of 99mTc-MAG3-clearance.

Increased FDG bone marrow uptake after intracoronary progenitor cell therapy

Patients with coronary artery disease who undergo FDG PET for therapy monitoring after intracoronary progenitor cell infusion (PCT) show an increased bone marrow up-take in some cases. Aim of the study was to evaluate the systemic bone marrow glucose metabolism in this patient group after PCT. Patients, methods: FDG bone marrow uptake (BMU), measured as standardized uptake value (SUVmax) in the thoracic spine, was retrospectively evaluated in 23 control patients who did not receive PCT and in 75 patients who received PCT 3 ± 2.2 days before PET scanning. Five out of them were pretreated with granulocyte colony-stimulating factor (G-CSF) 5 days prior to PCT and 10 ± 1.2 days before PET scanning. In 39 patients who received only PCT without G-CSF and underwent PET therapy monitoring 4 months later, baseline and follow up bone marrow uptake were measured. Leucocytes, C-reactive protein (CRP) levels and the influence of nicotine consumption were compared with the BMU. Results: In patients (n = 70) who received PCT without G-CSF, BMU median (1.3) was slightly, but significantly higher than in the controls (1.0) (p = 0.02) regardless nicotine consumption. BMU did not change significantly 4 months later (1.2) (p = 0.41, n.s.). After G-CSF pretreatment, patients showed a significantly higher bone marrow uptake (3.7) compared to patients only treated with PCT (1.3) (p = 0.023). Leucocyte blood levels were significantly higher in patients with a BMU ≥ 2.5 compared to patients with a bone marrow SUVmax < 2.5 (p <0.001). CRP values did not correlate with the BMU (rho -0.02, p = 0.38). Conclusion: Monitoring PCT patients, a slightly increased FDG BMU may be observed which remains unchanged for several months. Unspecific bone marrow reactions after PCT may be associated with increased leucocyte blood levels and play a role in the changed systemic glucose BMU.

FDG uptake after intraarterial chemotherapy in head and neck cancer

Aim: The intraarterial chemotherapy (i.a. CHT) using high dose cisplatin combined with systemic neutralization in patients with head and neck cancer (HNSCC) is used to reduce the tumor volume preoperatively. Aim of the study is the evaluation of the influence of i.a. CHT on the metabolism of fluor-18-deoxyglucose (FDG) in the primary and lymph nodes (LN). The value of FDG positron emission tomography (PET) preoperative and as follow-up method after i.a. CHT is examined. Patients, methods: Altogether 16 patients with HNSCC underwent two preoperative FDG PET examinations: the baseline examination one week before and the follow-up three weeks after i.a. CHT. The SUVmax values of the primary and the LN and LN metastases were evaluated and compared with each other and the histopathology. Results: The SUVmax value of the primary decreased after i.a. CHT significantly from a median (25th percentile/ 75th percentile) of 6.4 (4.1/ 7.8) to 3.6 (2.4/ 6.7) (p = 0.01). In 11 out of 16 patients cervical LN metastases were detected. The cervical LN metastases showed a decrease of the SUVmax value from 3.6 (2.3/ 4.8) in the pretreatment examination to 2.3 (1.7/ 3.6) after i.a. CHT (p = 0.008). Only in one patient with LN metastases the SUVmax of the nodes increased. The histopathologically measured size of the LN metastases ranged from 2 to 30 mm. Non malignant LN did not reveal a significant SUVmax decrease after i.a. CHT (p = 0.13). Conclusions: As expected, primaries of HNSCC showed a significant reduction of SUV after i.a. CHT. Compared to the primary the SUVmax decrease in LN metastases was less, but also significant. Since cytotoxic levels of cisplatin do not occur systemic, postinflammatory reactions of the LN or a lymphatic drainage of the chemotherapeutic drug into the LN could be an explanation. PET for staging of HNSCC must thus be performed prior to i.a. CHT.

Therapy of hepatocellular carcinoma with iodine-131-lipiodol

Aim: To evaluate the efficacy and tolerance of iodine- 131-lipiodol (131I-lipiodol) for hepatocellular carcinoma (HCC) in German long term patients and comparison with medically treated controls. Patients, Methods: 38 courses of intra-arterial 131I-lipiodol therapy with a total activity up to 6.7 GBq were performed in 18 patients with HCC (6 with portal vein thrombosis). Liver and tumour volume and lipiodol deposition were measured by computed tomography and 131I activity by scintigraphy. Therapeutic efficacy was determined by tumour volume change and matched-pairs analysis in comparison to medically (i.e. tamoxifen or medical support) treated patients. Results: Tumour volume decreased in 20/32 index nodules (63%) after the first course. Repeated therapy frequently resulted in further tumour reduction. Overall response to treatment was partial in 11 nodules, minor response in 4 nodules, and disease was stable in 12 and progressive in 5. Significant response was associated with pretherapeutic nodule volume up to 150 ml (diameter of 6.6 cm). Survival rate after 3, 6, 9, 12, 24 and 36 months was 78, 61, 50, 39, 17, and 6%. Matched-pairs analysis of survival revealed 131I-lipiodol to be superior to medical treatment. The most important side effect was a pancreatitis-like syndrome whereas overall tolerance was good. Conclusion: The long term results confirm that HCC therapy with 131I-lipiodol is effective and probably superior to medical treatment. Tumour nodules of up to 6 cm diameter are well suited for this therapy even in the presence of portal vein thrombosis.

Limitations of dual time point FDG-PET imaging in the evaluation of focal abdominal lesions

Aim: For the evaluation of the diagnostic potential of dual time point FDG positron emission tomography (PET) in patients with suspicious focal abdominal up-take, dual time point PET imaging was compared with clinical findings. Patients, methods: In a prospective study, 56 patients exhibiting a solitary suspicious, intense abdominal FDG uptake, underwent dual time point PET imaging for staging or restaging of different malignant tumors, maximal standardized uptake value (SUVmax) measurements included. The first acquisition was started 64.8 ± 19.5, the second 211.3 ± 52.5 min after FDG injection. The final diagnosis based on CT or MRT imaging and a follow-up period of 12.6 ± 2.8 months. Additionally, colonoscopy was done in 6 patients. In another 6 patients histopathology was obtained from CT guided biopsy. Results: Malignant focal abdominal lesions with a SUVmax <2.5 (n = 4) showed an uptake increase of ≥30%. In the remaining malignant cases with an uptake of ≥2.5 (n = 11), up-take increased in 64% and decreased in 36%. Malignant lesions showing FDG uptake decrease (n = 4) had an initial SUVmax value ≥2.5 and remained with a SUVmax ≥2.5 in the second imaging. In benign lesions with an initial SUVmax ≥2.5 (n = 31), the uptake increased in 17 patients (55%) and decreased in 14 patients (45%). All lesions which changed configuration (33%) were confirmed as benign (n = 5). Conclusion: Using dual time point PET abdominal lesions show a very hetergenous uptake pattern regardless of their dignity. Malignancy can only be reliably excluded in lesions which change their configuration and in lesions with an initial SUVmax value <2.5 combined with an SUV decrease in the delayed imaging. Particularly abdominal lesions which show an initial SUVmax ≥2.5 combined with a SUV increase in the delayed imaging are suspicious for malignancy and need further clarification.

Endoscopic ultrasound-guided tissue sampling of small subepithelial tumors of the upper gastrointestinal tract with a 22-gauge core biopsy needle

Background and study aims The optimal approach to small subepithelial tumors (SETs) of the upper gastrointestinal tract remains inconclusive. The aim of this study was to evaluate endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for less invasive tissue sampling of small SETs of the upper gastrointestinal tract. Patients and methods In this prospective observational study patients with small ( ≤ 3 cm) SETs of the upper gastrointestinal tract were eligible and underwent EUS-FNB with a 22-gauge core biopsy needle. The main outcome measure was the diagnostic yield. The number of obtained core biopsies was also assessed. Results Twenty patients were included. The mean SET size was 16 mm (range 10 - 27 mm). EUS-FNB was technically feasible in all cases and no complications were observed. The diagnostic yield was 75 %. Core biopsy specimens were obtained in only 25 % of cases. Conclusion EUS-FNB with a 22-gauge core biopsy needle of small SETs can achieve a definite diagnosis in the majority of cases. However, because core samples cannot regularly be obtained, EUS-FNB seems not to be convincingly superior to standard EUS-FNA in this setting.

Bottom-Up Fabrication of Hybrid Plasmonic Sensors: Gold-Capped Hydrogel Microspheres Embedded in Periodic Metal Hole Arrays

The high potential of bottom-up fabrication strategies for realizing sophisticated optical sensors combining the high sensitivity of a surface plasmon resonance with the exceptional properties of stimuli-responsive hydrogel is demonstrated. The sensor is composed of a periodic hole array in a gold film whose holes are filled with gold-capped poly(N-isoproyl-acrylamide) (polyNIPAM) microspheres. The production of this sensor relies on a pure chemical approach enabling simple, time-efficient, and cost-efficient preparation of sensor platforms covering areas of cm². The transmission spectrum of this plasmonic sensor shows a strong interaction between propagating surface plasmon polaritons at the metal film surface and localized surface plasmon resonance of the gold cap on top of the polyNIPAM microspheres. Computer simulations support this experimental observation. These interactions lead to distinct changes in the transmission spectrum, which allow for the simultaneous, sensitive optical detection of refractive index changes in the surrounding medium and the swelling state of the embedded polyNIPAM microsphere under the gold cap. The volume of the polyNIPAM microsphere located underneath the gold cap can be changed by certain stimuli such as temperature, pH, ionic strength, and distinct molecules bound to the hydrogel matrix facilitating the detection of analytes which do not change the refractive index of the surrounding medium significantly.

Emergency video capsule endoscopy in patients with acute severe GI bleeding and negative upper endoscopy results

BACKGROUND

In mid-GI bleeding, video capsule endoscopy (VCE) shows the best diagnostic yield for ongoing overt bleeding. To date, the utility of VCE in acute severe GI bleeding has been analyzed rarely.

OBJECTIVE

To evaluate the impact of VCE when performed on patients with acute severe GI bleeding immediately after an initial negative upper endoscopy result.

DESIGN

Prospective study.

SETTING

Tertiary-care center.

PATIENTS

Patients with melena, dark-red or maroon stool, hemodynamic instability, drop of hemoglobin level ≥2 g/dL/day, and/or need of transfusion ≥2 units of packed red blood cells per day were included.

INTERVENTIONS

After a negative upper endoscopy result, emergency VCE was performed by immediate endoscopic placement of the video capsule into the duodenum.

MAIN OUTCOME MEASUREMENTS

Rate of patients in whom emergency VCE correctly guided further diagnostic and therapeutic procedures.

RESULTS

Upper endoscopy showed the source of bleeding in 68 of 88 patients (77%). In the remaining 20 patients (23%), emergency VCE was performed, which was feasible in 19 of 20 patients (95%; 95% confidence interval [CI], 75%-99%). Emergency VCE correctly guided further diagnostic and therapeutic procedures in 17 of 20 patients (85%; 95% CI, 62%-97%) and showed a diagnostic yield of 75% (95% CI, 51%-91%).

LIMITATIONS

Single-center study, small sample size.

CONCLUSION

In patients with acute severe GI bleeding and negative upper endoscopy results, emergency VCE can be useful for the immediate detection of the bleeding site and is able to guide further therapy. (Clinical trial registration number: NCT01584869.)

Enhancing second harmonic generation in gold nanoring resonators filled with lithium niobate

Plasmonic nanorings provide the unique advantage of a pronounced plasmonic field enhancement inside their core. If filled with a polarizable medium, it may significantly enhance its optical effects. Here, we demonstrate this proposition by filling gold nanorings with lithium niobate. The generated second harmonic signal is compared to the signal originating from an unpatterned lithium niobate surface. Measurements and simulation confirm an enhancement of about 20. Applications requiring nanoscopic localized light sources like fluorescence spectroscopy or quantum communication will benefit from our findings.

The spectral shift between near- and far-field resonances of optical nano-antennas

Within the past several years a tremendous progress regarding optical nano-antennas could be witnessed. It is one purpose of optical nano-antennas to resonantly enhance light-matter interactions at the nanoscale, e.g. the interaction of an external illumination with molecules. In this specific, but in almost all schemes that take advantage of resonantly enhanced electromagnetic fields in the vicinity of nano-antennas, the precise knowledge of the spectral position of resonances is of paramount importance to fully exploit their beneficial effects. Thus far, however, many nano-antennas were only optimized with respect to their far-field characteristics, i.e. in terms of their scattering or extinction cross sections. Although being an emerging feature in many numerical simulations, it was only recently fully appreciated that there exists a subtle but very important difference in the spectral position of resonances in the near-and the far-field. With the purpose to quantify this shift, Zuloaga et al. suggested a Lorentzian model to estimate the resonance shift. Here, we devise on fully analytical grounds a strategy to predict the resonance in the near-field directly from that in the far-field and disclose that the issue is involved and multifaceted, in general. We outline the limitations of our theory if more sophisticated optical nano-antennas are considered where higher order multipolar contributions and higher order antenna resonances become increasingly important. Both aspects are highlighted by numerically studying relevant nano-antennas.

Resonant metasurfaces at oblique incidence: interplay of order and disorder

Understanding the impact of order and disorder is of fundamental importance to perceive and to appreciate the functionality of modern photonic metasurfaces. Metasurfaces with disordered and amorphous inner arrangements promise to mitigate problems that arise for their counterparts with strictly periodic lattices of elementary unit cells such as, e.g., spatial dispersion, and allows the use of fabrication techniques that are suitable for large scale and cheap fabrication of metasurfaces. In this study, we analytically, numerically and experimentally investigate metasurfaces with different lattice arrangements and uncover the influence of lattice disorder on their electromagnetic properties. The considered metasurfaces are composed of metal-dielectric-metal elements that sustain both electric and magnetic resonances. Emphasis is placed on understanding the effect of the transition of the lattice symmetry from a periodic to an amorphous state and on studying oblique illumination. For this scenario, we develop a powerful analytical model that yields, for the first time, an adequate description of the scattering properties of amorphous metasurfaces, paving the way for their integration into future applications.

Plasmonic heating with near infrared resonance nanodot arrays for multiplexing optofluidic applications

In this work, we show local laser-induced heating in fluids with gold nanodot arrays prepared by electron-beam lithography that cover resonances in the near infrared spectral range from 750 nm to 880 nm.

BLADE sequences in sagittal T2-weighted MR imaging of the cervical spine and spinal cord--lesion detection and clinical value

PURPOSE

Using the BLADE (PROPELLER) technique for T2-weighted MR imaging of the cervical spine has proven to be a reliable tool for reducing artifacts typically for this region. The aim of this study was to evaluate whether the application of BLADE sequences has an impact on the detection of small or low contrast spinal cord and epidural lesions.

MATERIALS AND METHODS

A standard TSE and a BLADE sequence were compared in 33 patients with 46 spinal cord and epidural lesions for T2-weighted sagittal imaging of the cervical spine. Image sharpness, visualization of the dura, reliability of spinal cord depiction as well as lesion contrast were evaluated by two independent readers. Additionally two experienced neuroradiologists selected in consensus the sequence they would prefer for diagnostic purposes. Statistical evaluations were performed using the sign and the χ2 test.

RESULTS

BLADE was significantly superior to TSE regarding image sharpness, visualization of the dura and reliability of spinal cord depiction. Regarding lesion contrast there was a positive trend towards the BLADE sequence. In 17 of 46 lesions, BLADE was judged superior to TSE, while TSE was favored in 10 lesions. In consensus reading both neuroradiologists preferred BLADE for overall image quality in 27 of 33 patients and for lesion contrast in 10 and TSE in 14 of the 33 patients, but 3 TSE sequences were rated as non-diagnostic regarding this criterion.

CONCLUSION

For the detection of even small and low-contrast spinal cord lesions, BLADE is at least equivalent to TSE, yielding better overall image quality and fewer non-diagnostic images.

Deep-subwavelength plasmonic nanoresonators exploiting extreme coupling

A metal-insulator-metal (MIM) waveguide is a canonical structure used in many functional plasmonic devices. Recently, research on nanoresonantors made from finite, that is, truncated, MIM waveguides attracted a considerable deal of interest motivated by the promise for many applications. However, most suggested nanoresonators do not reach a deep-subwavelength domain. With ordinary fabrication techniques the dielectric spacers usually remain fairly thick, that is, in the order of tens of nanometers. This prevents the wavevector of the guided surface plasmon polariton to strongly deviate from the light line. Here, we will show that the exploitation of an extreme coupling regime, which appears for only a few nanometers thick dielectric spacer, can lift this limitation. By taking advantage of atomic layer deposition we fabricated and characterized exemplarily deep-subwavelength perfect absorbers. Our results are fully supported by numerical simulations and analytical considerations. Our work provides impetus on many fields of nanoscience and will foster various applications in high-impact areas such as metamaterials, light harvesting, and sensing or the fabrication of quantum-plasmonic devices.

What limits tool use in nonhuman primates? Insights from tufted capuchin monkeys (Sapajus spp.) and chimpanzees (Pan troglodytes) aligning three-dimensional objects to a surface

Perceptuomotor functions that support using hand tools can be examined in other manipulation tasks, such as alignment of objects to surfaces. We examined tufted capuchin monkeys' and chimpanzees' performance at aligning objects to surfaces while managing one or two spatial relations to do so. We presented six subjects of each species with a single stick to place into a groove, two sticks of equal length to place into two grooves, or two sticks joined as a T to place into a T-shaped groove. Tufted capuchins and chimpanzees performed equivalently on these tasks, aligning the straight stick to within 22.5° of parallel to the groove in approximately half of their attempts to place it, and taking more attempts to place the T stick than two straight sticks. The findings provide strong evidence that tufted capuchins and chimpanzees do not reliably align even one prominent axial feature of an object to a surface, and that managing two concurrent allocentric spatial relations in an alignment problem is significantly more challenging to them than managing two sequential relations. In contrast, humans from 2 years of age display very different perceptuomotor abilities in a similar task: they align sticks to a groove reliably on each attempt, and they readily manage two allocentric spatial relations concurrently. Limitations in aligning objects and in managing two or more relations at a time significantly constrain how nonhuman primates can use hand tools.

Observations on the effects of inhaled isoflurane in long-term sedation of critically Ill children using a modified AnaConDa©-system

Long-term intravenous sedation may present problems due to dependence and side effects. Medical records of children who were administered isoflurane were reviewed. 15 patients (9 boys, 6 girls) with a mean age of 11.8 month (+2.4) were analysed.Analgesia and sedation was given in mean 9.7+1.1 days before commencing inhalation using a modified application device (AnaConDa©). Administration was given over a period of 7.2+1.4 days. Depth of sedation was monitored by using Comfort- and Hartwig-scores. Observations included continuous monitoring of heart-rate, pulse oxymetry, blood pressure and cerebral tissue oxygenation.Within 4 h post administration of isoflurane a satisfactory increase in the depth of sedation was seen and kept till extubation. 6/15 patients received tracheostomies during the observation period. None of the patients observed suffered life-critical events of the modified application of isoflurane proceeded without complications. Ketamine and clonidine infusion rates were significantly reduced (p<0.005) as well as the use and overall infusion rate of midazolam, γ-hydroxy butyrate, fentanyl and morphine (p<0.05).Isoflurane inhalation may provide an additional option for long-term sedation in a specific group of critically ill infants but neurodegenerative toxic effects will have to be taken into account when using volatile anesthetics at any time during infancy.

Phase anomalies in Talbot light carpets of self-images

An interesting feature of light fields is a phase anomaly, which occurs on the optical axis when light is converging as in a focal spot. Since in Talbot images the light is periodically confined in both transverse and axial directions, it remains an open question whether at all and to which extent the phase in the Talbot images sustains an analogous phase anomaly. Here, we investigate experimentally and theoretically the anomalous phase behavior of Talbot images that emerge from a 1D amplitude grating with a period only slightly larger than the illumination wavelength. Talbot light carpets are observed close to the grating. We concisely show that the phase in each of the Talbot images possesses an anomalous axial shift. We show that this phase shift is analogous to a Gouy phase of a converging wave and occurs due to the periodic light confinement caused by the interference of various diffraction orders. Longitudinal-differential interferometry is used to directly demonstrate the axial phase shifts by comparing Talbot images phase maps to a plane wave. Supporting simulations based on rigorous diffraction theory are used to explore the effect numerically. Numerical and experimental results are in excellent agreement. We discover that the phase anomaly, i.e., the difference of the phase of the field behind the grating to the phase of a referential plane wave, is an increasing function with respect to the propagation distance. We also observe within one Talbot length an irregular wavefront spacing that causes a deviation from the linear slope of the phase anomaly. We complement our work by providing an analytical model that explains these features of the axial phase shift.

[Perfusion brain imaging with SPECT-technique. German Guideline S1]

This paper describes the guideline for perfusion brain imaging with SPECT-technique published by the Association of the Scientific Medical Societies in Germany (AWMF).The purpose of this guideline is to provide practical assistance for indication, examination procedures, findings and their interpretation also reflecting the present state of the art. Information and instruction are given regarding indication, preparation of the patients and examination procedures of brain perfusion SPECT, including preparation and quality control of the tracer as well as the radiation dosimetry, technical performance of image acquisition with the gamma-camera and image processing. Also advices for interpretation of findings are given. In addition, possible pitfalls are described.

Hirnperfusions-SPECT mit 99mTc-Radiopharmaka

This paper describes the guideline for perfusion brain imaging with SPECT-technique published by the Association of the Scientific Medical Societies in Germany (AWMF). The purpose of this guideline is to provide practical assistance for indication, examination procedures, findings and their interpretation also reflecting the present state of the art. Information and instruction are given regarding indication, preparation of the patients and examination procedures of brain perfusion SPECT, including preparation and quality control of the tracer as well as the radiation dosimetry, technical performance of image acquisition with the gamma-camera and image processing. Also advices for interpretation of findings are given. In addition, possible pitfalls are described.

Perfect absorbers on curved surfaces and their potential applications

Recently perfect metamaterial absorbers triggered some fascination since they permit the observation of an extreme interaction of light with a nanostructured thin film. For the first time we evaluate here the functionality of such perfect absorbers if they are applied on curved surfaces. We probe their optical response and discuss potential novel applications. Examples are the complete suppression of back-scattered light from the covered objects, rendering it cloaked in reflection, and their action as optical black holes.

Talbot images of wavelength-scale amplitude gratings

By means of experiment and simulation, we achieve unprecedented insights into the formation of Talbot images to be observed in transmission for light diffracted at wavelength-scale amplitude gratings. Emphasis is put on disclosing the impact and the interplay of various diffraction orders to the formation of Talbot images. They can be manipulated by selective filtering in the Fourier plane. Experiments are performed with a high-resolution interference microscope that measures the amplitude and phase of fields in real-space. Simulations have been performed using rigorous diffraction theory. Specific phase features, such as singularities found in the Talbot images, are discussed. This detailed analysis helps to understand the response of fine gratings. It provides moreover new insights into the fundamental properties of gratings that often find use in applications such as, e.g., lithography, sensing, and imaging.

Genuine effectively biaxial left-handed metamaterials due to extreme coupling

Most left-handed metamaterials cannot be described by local effective permittivity or permeability tensors in the visible or near-infrared due to the mesoscopic size of the respective unit cells and the related strong spatial dispersion. We lift this problem and propose a metamaterial exhibiting artificial magnetism that does not suffer from this restriction. The artificial magnetism arises from the extreme coupling between both metallic films forming the unit cell. We show that its electromagnetic response can be properly described by biaxial local constitutive relations. A genuine biaxial left-handed fishnet metamaterial is suggested, which can be realized by atomic layer deposition to fabricate the nanoscaled spacing layers required for extreme coupling.

Chiral metamaterial composed of three-dimensional plasmonic nanostructures

We introduce a top-down fabricated metamaterial composed of three-dimensional, chiral, plasmonic nanostructures for visible and near-infrared wavelengths. Based on a combined spectroscopic and interferometric characterization, the entire complex transmission response in terms of a Jones matrix is disclosed. Particularly, the polarization output state of light after propagation through the nanostructures can be decoded from the measurements for any excitation configuration. We experimentally found a rotation of the polarization azimuth of linearly polarized light exceeding 50° at wavelengths around 1.08 μm. This corresponds to a specific rotation which is significantly larger than that of any linear, passive, and reciprocal medium reported to date.

Characterization of microvascularization of liver tumor lesions with high resolution linear ultrasound and contrast enhanced ultrasound (CEUS) during surgery: First results

AIM

Evaluation of high resolution linear ultrasound and intra-operative linear contrast enhanced ultrasound (CEUS) and its benefit for the detection and characterization of tumor lesions.

MATERIAL AND METHODS

Twenty patients were investigated preoperatively regarding tumor detection using CT (n = 8) or MRI (n = 12) and image fusion (VNav) (n = 3). All patients had surgery for their hepatic tumor (hepatocellular carcinoma (HCC), cholangiocellular carcinoma (CCC), metastasis, and adenoma). Ultrasound was performed intra-operatively first with B-scan using a convex probe. Than multifrequency linear transmitters (6-9 MHz, 6-15 MHz, LOGIQ E9, GE) were applied for B-scan, coulor coded Doppler sonography (CCDS) and Power Doppler followed by dynamic CEUS with Contrast Harmonic Imaging (CHI) after bolus injection of a maximum of 15 mL SonoVue®.

RESULTS

In 9 cases with the use of intra-operative CEUS additional tumor lesions (diameter 4-15 mm) could be detected and were histologically confirmed after surgical resection (7 cases) or intra-operative biopsy (2 cases). Using intraoperative CEUS 64 tumor lesions could be detected compared to 51 tumor lesions detected by preoperative CT or MRI (p < 0.05). Using the 6-15 MHz multifrequency linear transducer with CHI, arterial perfusion of adenomas, neuroendocrine metastases and HCC lesions was detectable. In 3 cases a resection was not achievable. Two of these cases were treated with radio frequency ablation (RFA). The other case had no curable option due to multifocal tumor manifestation.

CONCLUSION

The intra-operative use of high-resolution linear transducer techniques with CEUS offers new diagnostic perspectives for an effective liver surgery.

Abstract P4-10-06: 10-Years Results of Intraoperative Electron Radiotherapy (IOERT) in Boost Modality in Breast Cancer Patients Treated with Breast Conserving Surgery

Introduction:

The aim of this nonrandomized study was to compare the ipsilateral breast tumor recurrence rates in patients with invasive breast cancer, who had been treated with breast conserving surgery and whole breast irradiation and conventional boost or intraoperative electron radiotherapy boost (IOERT).

Patients and Methods:

378 patients were included in the study, 188 patients in group 1 (conventional boost) and 190 patients in group 2 (IOERT boost). Patients were comparable with regard to age, menopausal status, tumor size, histological type, grading and axillary lymph node status. Included were patients with invasive breast cancer pT1 and pT2, N0, N1, N2, M0, and breast conserving surgery with clear margins &gt;3mm. Excluded were patients with DCIS only, patients with invasive breast cancers larger than pT2, patients after primary systemic therapy and patients with multicentric disease. All patients (group 1 and group 2) received postoperative whole breast irradiation of 51-56.1 Gy. Group 1 received postoperative electron boost irradiation of 12 Gy after whole breast irradiation and group 2 received one intraoperative electron boost of 9 Gy in a single fraction during surgery before whole breast irradiation. Results:

The 10-years actuarial rates of ipsilateral breast tumor recurrence (IBTR), true local recurrence (TLR), distant recurrence (DR) and disease free survival (DFS) were 7.1% (95%CI, 3.2-11.0%), 4.8% (95%CI, 1.5-8.0%), 14,2% (95%CI, 9.1-19.4%) and 82.4% respectively in group1 and 2.7% (95%CI, 0.0-5.9%, P=0.062), 0.7% (95%CI, 0.0-2.0%, P=0.016), 13.6% (95%CI, 5.0-22.2%, P=0.90) and 84.0% (P= 0.76) respectively in group 2.

Conclusion:

Patients treated with IOERT boost and whole breast irradiation achieve excellent local control rates at 10 years and exhibit statistically significant decreased true local recurrence rates compared to patients treated with whole breast irradiation and conventional electron boost.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-10-06.

Understanding the electric and magnetic response of isolated metaatoms by means of a multipolar field decomposition

We introduce a technique to decompose the scattered near field of two-dimensional arbitrary metaatoms into its multipole contributions. To this end we expand the scattered field upon plane wave illumination into cylindrical harmonics as known from Mie's theory. By relating these cylindrical harmonics to the field radiated by Cartesian multipoles, the contribution of the lowest order electric and magnetic multipoles can be identified. Revealing these multipoles is essential for the design of metamaterials because they largely determine the character of light propagation. In particular, having this information at hand it is straightforward to distinguish between effects that result either from the arrangement of the metaatoms or from their particular design.

Asymmetric transmission of linearly polarized light at optical metamaterials

We experimentally demonstrate a three-dimensional chiral optical metamaterial that exhibits an asymmetric transmission for forwardly and backwardly propagating linearly polarized light. The observation of this novel effect requires a metamaterial composed of three-dimensional chiral meta-atoms without any rotational symmetry. Our analysis is supported by a systematic investigation of the transmission matrices for arbitrarily complex, generally lossy media that allows deriving a simple criterion for asymmetric transmission in an arbitrary polarization base. Contrary to physical intuition, in general the polarization eigenstates in such three-dimensional and low-symmetry metamaterials do not obey fixed relations and the associated transmission matrices cannot be symmetrized.

High-throughput matrix-assisted laser desorption ionization-time-of-flight mass spectrometry method for quantification of hepcidin in human urine

Levels of the peptide hormone hepcidin negatively correlate with systemic iron status and are increased in disorders in which iron metabolism is secondarily disregulated, such as the anemia of chronic disease. Consequently, the ability to measure hepcidin in the clinical setting may have diagnostic value for a broad range of indications. We describe a novel quantitative matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry assay for hepcidin in human urine which involves (i) direct enrichment from minute volumes (5 microL) of minimally treated urine on the surface of a functionalized chip, (ii) quantification by the use of a stable isotope labeled internal standard, and (iii) analysis by MALDI-TOF. Performance features include a wide linear range (1-1000 nM; LOQ 2.5 nM), high accuracy (90-110% recovery) and precision (intraday CV 12.11%; interday CV 13.21%), and a strong correlation upon interlaboratory cross validation with an existing immunoassay. The assay is simple, accurate, and efficient, and the high-throughput performance features of the assay make large-scale clinical research studies feasible.