Single-mode master-oscillator power amplifier at 647 nm with more than 500 mW output power.

Using an AlGaInP-based truncated tapered power amplifier, it was possible to boost the output power of a 647-nm distributed Bragg reflector laser from 50 mW to more than 500 mW. The light source has the potential to replace bulky Kr ion lasers still in use at this wavelength.

Inhibition of green algae growth by corrole-based photosensitizers.

AIMS: This study was performed to examine the potential of photodynamic inactivation for growth inhibition of green algae through generation of singlet oxygen. METHODS AND RESULTS: Two cationic and two anionic corroles were investigated according to their photoinhibitive effect on two strains of green algae using visible light for photoexcitation. The development of biomass over the experimental period of 18 days was followed using absorptive properties of the algae samples. The anionic photosensitizers showed no significant phototoxicity, whereas the cationic photosensitizers caused a drastic reduction of biomass on a short time scale and also displayed long-term inhibition of algae growth. CONCLUSIONS: In general, it was proven that photodynamic inactivation of green algae is possible. Concluding from the results of this study, cationic photosensitizers are favourable for this task, while anionic photosensitizers are not suited. SIGNIFICANCE AND IMPACT OF THE STUDY: Phototrophic biofilms are an important factor in biofouling and biodeterioration of building materials, causing great damage to historic and contemporary constructions. Growth inhibition of phototrophic organisms using photodynamic inactivation could pose an alternative to the use of biocides. To this end, successful application of this approach on green algae is a vital step in the development of suitable photosensitizers.

[Detection of early neoplasia in Barrett's oesophagus: focus attention on index endoscopy in short-segment-Barrett's oesophagus with random biopsies]. / Detektion von frühen Neoplasien im Barrett-Ösophagus: Ein Plädoyer für die Wertigkeit der Indexendoskopie und 4-Quadranten-Biopsien im Short-Segment-Barrett-Ösophagus.

BACKGROUND: Detecting early neoplasias in Barrett's oesophagus (BE) is challenging. Recent publications have been focusing on improving the detection of such lesions during Barrett's surveillance. However in a recently published Danish register study calculating the risk for cancer-development in BE two-thirds of the diagnosed tumors were identified during the first examination or in the first year. This means that index endoscopy might be more effective than surveillance in detecting early neoplasia in BE. METHODS: In the period from January 2010 to April 2011, all patients who consecutively presented with a diagnosis of early neoplastic changes in BE were recorded prospectively. ANALYSIS: The analysis included data for 121 patients. In patients with short-segment BE (SSBE), neoplasia was only diagnosed in 6 % of cases in the surveillance examination, compared with 44 % of cases in long-segment BE (LSBE). The neoplastic lesion was identified visually in 43 patients (36 %) during the external EGD. Type II tumours were detected in 40 % (39/98) and were correctly assessed as neoplastic in 25 % of cases (24/98). CONCLUSIONS: 1. in patients with SSBE almost all early tumours are diagnosed by index endoscopy and not by Barrett's surveillance; 2. around 40 % of all early neoplasias are endoscopically invisible and are only diagnosed using four-quadrant biopsies; 3. the macroscopic tumour type has a substantial influence on the detection rate for neoplasia. If efforts to increase the detection rate for early neoplasia in BE are focused solely on the Barrett's surveillance method, then only a minority of patients - 20 % in the present group - will benefit from the measure. German clinical trials register, DRKS00 004 168.

Endoscopic management for patients with serrated polyposis syndrome is feasible and effective: a prospective observational study at a tertiary centre.

BACKGROUND AND STUDY AIMS: Serrated polyposis syndrome is a rare condition in which multiple serrated lesions develop all over the colon, which is thought to be associated with an increased risk for the development of cancer. The aim of this study was to investigate the feasibility of endoscopic treatment and standardised surveillance in patients with this increasingly recognised syndrome. METHODS: From September 2010 to November 2013, consecutive patients were included in a prospective study. All patients underwent chromoendoscopy at first presentation and during surveillance. Follow-up examinations were carried out at 3 month intervals until complete clearance was achieved. Afterwards, patients entered a standardised surveillance protocol with a chromoendoscopic colonoscopy annually. RESULTS: Altogether 100 colonoscopies were carried out in 28 patients, with endoscopic resection of 436 lesions. Total clearance was accomplished in 27 patients (96.0 %) after 2.5 colonoscopies (range 1 - 8). Histology revealed 359 hyperplastic polyps (82.3 %), 37 sessile serrated adenomas (8.5 %), 36 low-grade adenomas (8.3 %), and one patient with advanced colorectal cancer. Twelve patients (42.8 %) had serrated polyps > 10 mm in size. During the surveillance period, 86 additional lesions were detected and resected. The mean follow-up period was 21.5 months (range 2 - 39 months). No interval carcinoma was detected during the surveillance. CONCLUSIONS: The present study indicates that endoscopic management in patients who meet the diagnostic criteria for serrated polyposis syndrome is feasible and safe. In particular, the incidence of colorectal cancer in this cohort was lower in comparison with previous studies.

[Acute complications after endoscopic resection of duodenal adenomas]. / Akutkomplikationen nach endoskopischer Resektion von Duodenaladenomen.

With the increasing technological development of endoscopy in recent years the diagnosis of and endoscopic therapy for duodenal adenomas has gained in importance. Due to its potentially malignant transformation an effective and safe therapy is necessary. The endoscopic resection has been shown to be safe and effective, even in cases of resection of large duodenal adenomas. Several studies have supported this thesis but are based on relatively small numbers of patients. In our clinic we have performed endoscopic resections of 178 duodenal adenomas over a period of 14 years, including sporadic duodenal adenomas as well as adenomas in familial polyposis syndromes. The aim of this retrospective analysis was to determine the acute complications associated with this technique. The rate of severe complications such as major bleeding or perforations was 9%. Further complications were minor bleeding (15.7%), pain needing treatment with analgesia (6.7%), fever (2.8%) and pancreatitis (0.6%). Summing up our experience with the endoscopic resection of adenomas of the small bowel we also consider the endoscopic resection of duodenal adenomas in most cases as a safe and effective alternative to surgical therapy. Because of the potential complications and their management especially in the resection of large adenomas with a size more than 2 cm, the endoscopic resection should be performed on an inpatient basis in experienced centres.

Analysis of cefaclor in novel chocolate-based camouflage capsules.

The determination of cefaclor in a new, complex chocolate matrix was performed by using a simple sample preparation (dispersion in dilute hydrochloric acid at 80 degrees C, centrifugation, washing with cyclohexane), followed by ion pair HPLC on a Kinetex pentafluorophenyl core-shell stationary phase with UV detection at 265 nm. We obtained good linearity (R2 = 0.9976) and precision (average RSD 0.86%) for the relevant concentration range. The preparations, although hand-made in this pilot phase, showed good uniformity of content. After being stored for four weeks in a refrigerator the preparation did not contain recognizable amounts of decomposition products.

Upper limb movement quality measures: comparing IMUs and optical motion capture in stroke patients performing a drinking task.

Introduction: Clinical assessment of upper limb sensorimotor function post-stroke is often constrained by low sensitivity and limited information on movement quality. To address this gap, recent studies proposed a standardized instrumented drinking task, as a representative daily activity combining different components of functional arm use. Although kinematic movement quality measures for this task are well-established, and optical motion capture (OMC) has proven effective in their measurement, its clinical application remains limited. Inertial Measurement Units (IMUs) emerge as a promising low-cost and user-friendly alternative, yet their validity and clinical relevance compared to the gold standard OMC need investigation. Method: In this study, we conducted a measurement system comparison between IMUs and OMC, analyzing 15 established movement quality measures in 15 mild and moderate stroke patients performing the drinking task, using five IMUs placed on each wrist, upper arm, and trunk. Results: Our findings revealed strong agreement between the systems, with 12 out of 15 measures demonstrating clinical applicability, evidenced by Limits of Agreement (LoA) below the Minimum Clinically Important Differences (MCID) for each measure. Discussion: These results are promising, suggesting the clinical applicability of IMUs in quantifying movement quality for mildly and moderately impaired stroke patients performing the drinking task.

Monolithic 626 nm single-mode AlGaInP DBR diode laser.

Single-mode lasers below 630 nm are still realized using complex laser systems. We present distributed Bragg reflector (DBR) ridge waveguide lasers (RWL) based on AlGaInP. When packaged into sealed TO-3 housings and cooled internally to about 0°C the DBR-RWL emit more than 50 mW at a wavelength of 626.0 nm into a nearly diffraction-limited single longitudinal mode with a spectral width below 1 MHz. These new monolithic diode lasers have the potential to drastically miniaturize existing set-ups e.g. for quantum information processing.

[Esophageal precancerous lesions: early diagnosis, treatment, and preservation of quality of life]. / Präkanzerosen im Ösophagus: Früherkennung, sichere Behandlung und Erhalt der Lebensqualität.

Modern high-resolution video endoscopes allow detailed examination of the esophageal mucosa and diagnosis of early neoplastic changes in the gastrointestinal tract. Whereas Barrett's esophagus is a precancerous condition that can develop into adenocarcinoma, there is no defined precancerous lesion for squamous cell carcinoma. Various diseases are associated with the development of esophageal squamous cell carcinoma. Chromoendoscopy has become an established method in the diagnostic work-up for better visualization of early neoplasia. If Barrett's esophagus is present, acetic acid spraying or virtual chromoendoscopy can be used to accentuate the display of superficial gyriform structures in the mucosa. The gold standard for detecting squamous cell carcinoma is still the use of Lugol solution. When early neoplasia is suspected, diagnostic endoscopic resection should be performed. This allows precise histological assessment of the tumor. Early diagnosis of neoplastic changes in the esophagus provides patients not only with the option of curative therapy but also with a good quality of life through preservation of the esophagus.

[Massive pancarditis-autopsy report]. / Massive Pankarditis ­ ein Autopsiebericht.

We report on a 69-year-old man suffering from chronic progressive oligoarthritis (localized in metacarpal and knee joints), which clinically was interpreted as steroid-sensitive seronegative chronic arthritis. The patient died from sudden death at the emergency department after a 4-week history of increasing cough and dyspnea (meanwhile obtaining negative testing results for SARS-CoV-2). During the autopsy, we found massive pancarditis affecting all cardiac compartments, in particular exhibiting constrictive pericarditis, myocarditis, and multivalvular endocarditis. Microscopically, interstitial myocarditis could be observed. Performing extensive molecular analyses, we detected Tropheryma whipplei in the tissue specimens of the heart, but not in various duodenal tissue probes or in the synovial membrane. Taken together, in the present case the cause of death was acute cardiac failure due to multivalvular pancarditis due to T. whipplei. Besides from classical symptoms and morphological signs, Whipple's disease may present with various features. Regarding the differential diagnosis of a chronic multisystem disorder with aspects of hitherto unknown arthralgia, Whipple's disease should be considered.

Transnasal endoscopy for direct visual control of esophageal stent placement without fluoroscopy.

Placement of self-expanding metal stents (SEMSs) is a well-established treatment for esophageal stenosis and postoperative anastomotic leaks. Conventional endoscopic procedures for SEMS placement require fluoroscopic guidance, but transnasal endoscopy (TNE) with ultraslim endoscopes may allow precise stent release under direct visual control without the need for fluoroscopy. This prospectively collected data investigated the feasibility and safety of TNE-guided SEMS placement without fluoroscopy. Between March 2009 and February 2011, 20 consecutive patients underwent TNE-guided SEMS placement without fluoroscopy. The technical success rate was 100 % and no fluoroscopy was required during the procedures. Five patients underwent SEMS placement as a bedside procedure in the intensive care unit. The mean intervention time was 13.4 minutes (range 6 - 26) and there were no early complications. In summary, TNE-guided SEMS placement allows precise stent placement without fluoroscopic control and can therefore be performed as a simple bedside procedure.

Long-term outcome after argon plasma coagulation of small-bowel lesions using double-balloon enteroscopy in patients with mid-gastrointestinal bleeding.

BACKGROUND AND STUDY AIMS: Vascular malformations are the most common sources of bleeding in the small bowel. They can be treated with argon plasma coagulation (APC) during double-balloon enteroscopy (DBE). This study aimed to evaluate the long-term follow-up of the effectiveness of APC for small-bowel bleeding by means of a single-center retrospective study. PATIENTS AND METHODS: Between June 2003 and December 2005, APC treatment for small-bowel lesions was carried out during DBE in 63 patients with known or suspected mid-gastrointestinal bleeding. Fifty patients were included in the analysis. Main outcome measurements were comparison of hemoglobin values and blood transfusion requirements before and after APC, and rebleeding rates. RESULTS: Twenty-nine patients (58%) had only oral DBE, whereas 21 patients (42%) underwent combined oral and anal approaches. The most frequent bleeding sources treated with APC were angiodysplasias in 44 patients (88%). Hemoglobin levels increased distinctly and stabilized after APC during a mean long-term follow-up of 55 ± 7 months, with mean levels of 7.6 g/dL before APC and 11.0 g/dL afterwards. Blood transfusion requirements substantially declined, from 30 patients (60%) before APC to 8 (16%) afterwards. However, small-bowel bleeding recurred in 21 patients (42%), particularly in patients with Osler disease (6 of 8 patients, 75%). CONCLUSIONS: Bleeding sources in the small bowel can be effectively treated with APC using DBE, and long-term follow-up data show a clear increase in hemoglobin levels and reduced blood transfusion requirements after APC. Further efforts are needed to reduce the rebleeding rate, possibly through more intensive initial treatment.

[Extensive squamous papillomatosis of the oesophagus with malignant transformation of squamous epithelium]. / Extensive Papillomatose des Ösophagus mit maligner Transformation des Plattenepithels.

While small solitary oesophageal papillomas are uncommon findings that are occasionally identified on routine upper endoscopies, extensive oesophageal papillomatosis is an extremely rare condition with only 9 cases reported in the English literature. We report the case of a 72-year-old woman who was referred for progressive dysphagia for solid food and clinical signs for a reflux disease. Upper endoscopy demonstrated bizarre villous alterations of the mucosa covering the oesophagus subtotally and a suspicious area within these alterations. Histological work-up of the biopsy samples revealed marked papillary hypertrophy and a squamous epithelial carcinoma in situ corresponding to the suspicious lesion. The patient underwent oesophagectomy with cervical gastroesophageal anastomosis and proximal remnants of papillomatous mucosa above the anastomosis were destroyed with endoscopic argon plasma coagulation. In the 2-year follow-up the patient showed limited recurrence of the papillomatosis in the remaining proximal oesophagus containing a circumscript carcinoma that was successfully treated by local endoscopic mucosectomy. Our case strongly underscores the risk of malignant transformation in large areas of papillomatous mucosa and shows that systematic surveillance is essential.

Development of a new peptide-bead coupling method for an all peptide-based Luminex multiplexing assay for detection of Plasmodium falciparum antibody responses.

Using a recombinant protein antigen for antibody testing shows a sum of antibody responses to multiple different immune epitopes existing in the protein antigen. In contrast, the antibody testing to an immunogenic peptide epitope reflects a singular antibody response to the individual peptide epitope. Therefore, using a panel of peptide epitopes provides an advantage for profiling multiple singular antibody responses with potential to estimate recent malaria exposure in human infections. However, transitioning from malaria immune epitope peptide-based ELISA to an all peptide bead-based multiplex Luminex assay presents some challenges including variation in the ability of different peptides to bind beads. The aim of this study was to develop a peptide coupling method while demonstrating the utility of these peptide epitopes from multiple stage antigens of Plasmodium falciparum for measuring antibodies. Successful coupling of peptide epitopes to beads followed three steps: 1) development of a peptide tag appended to the C-terminus of each peptide epitope consisting of beta-alanine-lysine (x 4)--cysteine, 2) bead modification with a high concentration of adipic acid dihydrazide, and 3) use of the peptide epitope as a blocker in place of the traditional choice, bovine serum albumin (BSA). This new method was used to couple 12 peptide epitopes from multiple stage specific antigens of P. falciparum, 1 Anopheles mosquito salivary gland peptide, and 1 Epstein-Barr virus peptide as an assay control. The new method was applied to testing of IgG in pooled samples from 30 individuals with previously repeated malaria exposure in western Kenya and IgM and IgG in samples from 37 U.S. travelers with recent exposure to malaria. The new peptide-bead coupling method and subsequent multiplex Luminex assay showed reliable detection of IgG to all 14 peptides in Kenyan samples. Among 37 samples from U.S. travelers recently diagnosed with malaria, IgM and IgG to the peptide epitopes were detected with high sensitivity and variation. Overall, the U.S. travelers had a much lower positivity rates of IgM than IgG to different peptide epitopes, ranging from a high of 62.2% positive for one epitope to a low of only 5.4% positive for another epitope. In contrast, the travelers had IgG positive rates from 97.3% to 91.9% to various peptide epitopes. Based on the different distribution in IgM and IgG positivity to overall number of peptide epitopes and to the number of pre-erythrocytic, erythrocytic, gametocytic, and salivary stage epitopes at the individual level, four distinct patterns of IgM and IgG responses among the 37 samples from US travelers were observed. Independent peptide-bead coupling and antibody level readout between two different instruments also showed comparable results. Overall, this new coupling method resolves the peptide-bead coupling challenge, is reproducible, and can be applied to any other immunogenic peptide epitopes. The resulting all peptide bead-based multiplex Luminex assay can be expanded to include other peptide epitopes of P. falciparum, different malaria species, or other diseases for surveillance, either in US travelers or endemic areas.

Analysis of Qa-1(b) peptide binding specificity and the capacity of CD94/NKG2A to discriminate between Qa-1-peptide complexes.

The major histocompatibility complex class Ib protein, Qa-1(b), serves as a ligand for murine CD94/NKG2A natural killer (NK) cell inhibitory receptors. The Qa-1(b) peptide-binding site is predominantly occupied by a single nonameric peptide, Qa-1 determinant modifier (Qdm), derived from the leader sequence of H-2D and L molecules. Five anchor residues were identified in this study by measuring the peptide-binding affinities of substituted Qdm peptides in experiments with purified recombinant Qa-1(b). A candidate peptide-binding motif was determined by sequence analysis of peptides eluted from Qa-1 that had been folded in the presence of random peptide libraries or pools of Qdm derivatives randomized at specific anchor positions. The results indicate that Qa-1(b) can bind a diverse repertoire of peptides but that Qdm has an optimal primary structure for binding Qa-1(b). Flow cytometry experiments with Qa-1(b) tetramers and NK target cell lysis assays demonstrated that CD94/NKG2A discriminates between Qa-1(b) complexes containing peptides with substitutions at nonanchor positions P4, P5, or P8. Our findings suggest that it may be difficult for viruses to generate decoy peptides that mimic Qdm and raise the possibility that competitive replacement of Qdm with other peptides may provide a novel mechanism for activation of NK cells.

Endoscopic closure of postoperative esophageal leaks with a novel over-the-scope clip system.

Management of esophageal anastomotic leaks is associated with high morbidity and mortality and remains an interdisciplinary challenge. We describe the first two cases of endoscopic closure of postoperative leaks following gastrectomy and primary repair after spontaneous acute esophageal perforation, using the over-the-scope clip (OTSC) system (Ovesco Endoscopy GmbH, Tübingen, Germany). Both leaks were successfully sealed with one clip. While one patient recovered without reintervention, in the other patient the postoperative leak reappeared following clip displacement 13 days later.

Computed image modification for enhancement of small-bowel surface structures at video capsule endoscopy.

Computed virtual chromoendoscopy with the Fujinon intelligent color-enhancement (FICE) system was reported to improve visualization of neoplastic and non-neoplastic lesions at gastroscopy and colonoscopy. The technique is based on narrowing the bandwidth of the conventional endoscopic image arithmetically by a spectral estimation technology. Implementation of the FICE software in the video capsule workstation might also allow for contrast-enhanced assessment of nature and extent of small-bowel mucosal lesions. Here we propose this novel technique and report on 10 consecutive patients who underwent small-bowel video capsule endoscopy that was evaluated with FICE-enhanced imaging.

Impact of fluoroscopy on oral double-balloon enteroscopy: results of a randomized trial in 156 patients.

BACKGROUND AND STUDY AIMS: The routine utility of fluoroscopy during double-balloon enteroscopy (DBE) via the oral route has been not prospectively evaluated. Up to now, there have been no prospective randomized trials to assess whether fluoroscopy improves outcomes. The aim of this study was to assess the value of fluoroscopy during oral DBE. PATIENTS AND METHODS: A total of 156 patients (88 men, 56.4 %) of mean (standard deviation [SD]) age 56 (19) years were randomly assigned to undergo oral DBE either with or without fluoroscopy. The majority of the patients had obscure gastrointestinal bleeding (n = 96, 62 %). The primary target criteria for the study were postpyloric insertion depth and time required to reach the deepest insertion point. A secondary target criterion was the diagnostic yield achieved. RESULTS: The results in the fluoroscopy and nonfluoroscopy groups did not differ significantly with respect to the mean (SD) insertion depth (fluoroscopy, 284 [89] cm, range 70 - 470 cm; nonfluoroscopy, 256 [86] cm, 40 - 430 cm), the mean time required to reach the deepest point of insertion, or the diagnostic yield achieved. In patients with previous abdominal surgery and during difficult procedures, the mean insertion depth was significantly lower. CONCLUSIONS: Fluoroscopy during DBE via the oral route does not provide a significant gain in insertion depth, advancement time, or diagnostic yield in comparison with nonfluoroscopically guided procedures. In experienced hands, fluoroscopy does not have to be used routinely during oral DBE.