Perceived balance and self-reported falls: A retrospective cross-sectional study using the National Health and Aging Trend Study

AIMS

To examine how perceived balance problems are associated with self-reported falls in the past month after controlling for known correlates of falls among older adults.

BACKGROUND

Approximately 30% of adults age 65 and older fall each year. Most accidental falls are preventable, and older adults' engagement in fall prevention is imperative. Limited research suggest that older adults do not use the term 'fall risk' to describe their risk for falls. Instead, they commonly use the term 'balance problems'. Yet, commonly used fall risk assessment tools in both primary and acute care do not assess older adults' perceived balance.

DESIGN AND METHOD

The Health Belief Model and the concept of perceived susceptibility served as the theoretical framework. A retrospective, cross-sectional secondary analysis using data from the National Health and Aging Trends Study from year 2015 was conducted. The outcome variable was self-reported falls in the last month.

RESULTS

A subsample of independently living participants (N = 7499) was selected, and 10.3% of the sample reported a fall. Multiple logistic regression analysis revealed that the odds of reporting a fall in the past month was 3.4 times (p < .001) greater for participants who self-reported having a balance problem compared to those who did not. In contrast, fear of falling and perceived memory problems were not uniquely associated with falls. Using a mobility device, reporting pain, poor self-rated health status, depression and anxiety scores were also associated with falling.

CONCLUSION AND IMPLICATIONS

Older adults' perceived balance problem is strongly associated with their fall risk. Perceived balance may be important to discuss with older adults to increase identification of fall risk. Older adults' perceived balance should be included in nursing fall risk assessments and fall prevention interventions. A focus on balance may increase older adults' engagement in fall prevention.

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.

Perceived Balance, Balance Performance, and Falls Among Community-Dwelling Older Adults: A Retrospective, Cross-Sectional Study

Objectives: To examine the extent to which older adults' perceived balance, a balance performance test, and fear of falling (FOF) were associated with falls in the last month. Methods: The Health Belief Model served as the theoretical framework. A retrospective, cross-sectional, secondary analysis using data from the National Health and Aging Trends Study was conducted (N = 7499). Results: Multiple logistic regression analysis revealed that the odds of reporting a fall in the past month were 3.3 times (p < .001) greater for participants who self-reported having a balance problem compared to those who did not. The Short Physical Performance Battery and FOF were not uniquely associated with falls. Discussion: Our findings support limited evidence suggesting that older adults' perceived balance is a better predictor of falls than balance performance. Assessing older adults' perceived balance may be a new way to assess older adults' fall risk to prevent future falls.

FAMILY CAREGIVER SOCIAL CONNECTEDNESS: TECHNOLOGY USE ACROSS GENERATIONS DURING THE COVID-19 PANDEMIC

During the COVID–19 pandemic, maintaining connectedness was difficult for caregivers. Family caregivers represent multiple generations whose experience with and use of social technology to maintain connectedness can vary and differentially impact critical health outcomes. The aims of this study were to examine caregiver connectedness and technology preferences across three generations of caregivers who provide care to older adults with chronic illnesses. The semi-structured focus-groups/interviews conducted in August of 2020 with family caregiver participants including Millennials (n=6), Generation X (n=5), and Boomer (n=8). Two researchers analyzed the transcribed content via thematic analysis. Similarities and differences across generations were assessed via comparative analysis. The themes that emerged from the data were: (1) Millennials (a) Altered stage of life, (b) Altered connectedness, (c) Need others to understand, (d) Stay away from social network sites; (2) Generation X (a) Altered connectedness, (b) Need others to understand, (c) Burden, (d) Fear-of-failure; and (3) Baby Boomer (a) Altered connectedness, (b) Technology builds connectedness, (c) Information seeking. All generations expressed alterations in connectedness with caregiver role. Millennials and Generation X caregivers emphasized need for others to understand that caregiving altered their lives with unique responsibilities. Technology use differed across the generations, with Millennial texting for confidential communications. Millennial and Generation X caregivers do not use social media due to envy of others’ fun. Baby Boomers expressed increased connectedness with the use of Zoom. Understanding the variation in the experience of caregiver connectedness and technology use by generation may identify targets for future caregiver connectedness intervention studies.

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.

Left ventricular global longitudinal strain reduction in patients with melanoma and extra-cardiac immune-related adverse events during immune checkpoint inhibitor therapy

Background

Immune checkpoint inhibitors (ICI) have tremendously improved survival in patients with melanoma. By unbalancing the immune system, ICI also generate immune-related adverse events (IRAEs) that could affect any tissue, including the heart. Early detection of IRAEs is essential to avoid life-threatening adverse events like myocarditis and to maintain patients under this effective therapy.

Aim

To identify whether patients treated with ICI that develop extra-cardiac IRAEs additionally show a subclinical impairment of the heart function.

Methods

We have analysed the patients with melanoma without established cardiac disease evaluated in our cardio-oncology unit between July 2018 and December 2019. Data was collected at two timepoints: before initiating the ICI therapy (baseline) and one month after ICI treatment begin (follow-up). Evaluation was performed using clinical data, laboratory parameter including biomarkers, electrocardiography, comprehensive 2D, 3D, tissue Doppler, and speckle tracking echocardiography assessment, and cardiac magnetic imaging.

Results

A total of 69 patients with melanoma (59±12 years old, 63% males, 93.8% metastatic disease), without known cardiovascular disease were included. Patients were divided in two groups: patients with extra-cardiac IRAEs (Group 1, n=22) and without IRAEs (Group 2, n=46) after one month of ICI therapy. One patient was diagnosed with immune-related myocarditis at follow-up and was excluded from the analysis. Patients in Group 1 developed colitis (n=10), thyroiditis/hypophysitis (n=8), hepatitis (n=2), and pneumonitis (n=2). There were no differences in age, gender distribution, cardiovascular risk factors, or proportion of metastatic disease between the two groups. The proportion of patients treated with combination ICI therapy (nivolumab plus ipilimumab) was significantly higher in Group 1 (72% vs. 33%, p=0.04). The left ventricular systolic and diastolic function were similar at baseline and after one month of therapy between the two groups, except for the global longitudinal strain (GLS), which showed a significant reduction at follow-up for patients in Group 1 vs. Group 2 (−18.8±2.6% vs. −21±1.2%, p=0.03). The radial and circumferential strain were similar. Follow-up GLS had a good correlation with the extra-cardiac IRAEs rate (r=0.43; p=0.03). Patients with combination ICI therapy had a 5 times higher risk to develop extra-cardiac IRAEs (OR 5.33, 95% CI (1.07–26.61), p=0.04). Troponin and NT-proBNP were not significantly different at follow-up between the two groups.

Conclusion

The abnormal function of the immune system triggered by ICI therapy in patients with extra-cardiac IRAEs seems to induce a subclinical left ventricular dysfunction, signalized by a reduction of the GLS. However, the diagnosis criteria for myocarditis were fulfilled in only one patient. The mechanism of these changes should be further investigated and addressed.

Funding Acknowledgement

Type of funding source: None

[Detection of early neoplasia in Barrett's oesophagus: focus attention on index endoscopy in short-segment-Barrett's oesophagus with random biopsies]

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.

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.

Electronic health records and patient safety: co-occurrence of early EHR implementation with patient safety practices in primary care settings

BACKGROUND

The role of electronic health records (EHR) in enhancing patient safety, while substantiated in many studies, is still debated.

OBJECTIVE

This paper examines early EHR adopters in primary care to understand the extent to which EHR implementation is associated with the workflows, policies and practices that promote patient safety, as compared to practices with paper records. Early adoption is defined as those who were using EHR prior to implementation of the Meaningful Use program.

METHODS

We utilized the Physician Practice Patient Safety Assessment (PPPSA) to compare primary care practices with fully implemented EHR to those utilizing paper records. The PPPSA measures the extent of adoption of patient safety practices in the domains: medication management, handoffs and transition, personnel qualifications and competencies, practice management and culture, and patient communication.

RESULTS

Data from 209 primary care practices responding between 2006-2010 were included in the analysis: 117 practices used paper medical records and 92 used an EHR. Results showed that, within all domains, EHR settings showed significantly higher rates of having workflows, policies and practices that promote patient safety than paper record settings. While these results were expected in the area of medication management, EHR use was also associated with adoption of patient safety practices in areas in which the researchers had no a priori expectations of association.

CONCLUSIONS

Sociotechnical models of EHR use point to complex interactions between technology and other aspects of the environment related to human resources, workflow, policy, culture, among others. This study identifies that among primary care practices in the national PPPSA database, having an EHR was strongly empirically associated with the workflow, policy, communication and cultural practices recommended for safe patient care in ambulatory settings.

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.

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.

[Acute complications after endoscopic resection of duodenal adenomas]

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.

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]

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.

Effect of obesity on the acute inflammatory response in pregnant and cycling female rats

Nonpregnant female rats have a lower inflammatory response to lipopolysaccharide (LPS) than males and, at late stages of gestation, the fever response to this immunogen is almost completely suppressed. We have shown in males that obesity exacerbates sickness responses to pathogenic stimuli. In the present study, we investigated whether obesity would have a similar effect in females and reverse some of the suppressive effects of pregnancy on the innate immune response. Lean and diet-induced obese adult Wistar rats were randomly separated into either cycling or mated groups. On day 18 of pregnancy or in the metestrous/dioestrous phase in cycling rats, a single injection of LPS (100 μg/kg) was administered and rats were sacrificed 8h or 24 h later. In pregnant females, LPS induced a higher increase in body temperature in obese rats only at the 24-h time point and lower hypothalamic interleukin (IL)-1β expression and higher circulating levels of IL-1 receptor antagonist (ra) than their cycling counterparts. Conversely, there was no suppression of inflammatory signals in the white adipose tissue of pregnant rats. At 24 h post LPS, the cell surface marker CD11c and IL-6 mRNA expression were increased in white adipose tissue from obese rats regardless of reproductive state, whereas IL-1ra was highest in the LPS-treated obese pregnant group. In cycling females, LPS induced a higher fever response in obese rats accompanied by higher circulating levels of IL-6 and IL-1ra, as well as an increase in circulating leptin only in the obese cycling group. In the hypothalamus, obese rats showed significantly higher expression of nuclear factor-IL-6 in at the 8-h time point. Collectively, these results show that diet-induced obesity in females is associated with a similar pattern of response to that previously observed in males. On the other hand, obesity had limited effects in pregnant rats, with the exception of white adipose tissue.

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.

Structural and Electrical Properties of Undoped Microcrystalline Silicon Grown by 70 MHz and 13.56 MHz PECVD

Microcrystalline silicon films deposited by plasma methods have an optical absorption for photon energies above 2.0 eV lower than a-Si:H films and can be efficiently doped with boron or phosphorus. The most widely used deposition technique is the 13.56 MHz PECVD. However quite recently µc-Si:H films were grown at high deposition rates by the 70 MHz PECVD. In this work the authors report on a comparison between µc-Si:H films deposited by both 70 MHz and 13.56 MHz techniques. Particular attention has been devoted to differences and similarities between structural, compositional and electrical properties of the films deposited with the two systems.

The “Micromorph” Cell: a New Way to High-Efficiency-Low-Temperature Crystalline Silicon Thin-Film Cell Manufacturing?

In the past, microcrystalline silicon (μc-Si:H) has been successfully used as active semiconductor in entirely μc-Si:H p-i-n solar cells and a new type of tandem solar cell, called the “micromorph” cell, was introduced [1]. Micromorph cells consist of an amorphous silicon top cell and a microcrystalline bottom cell. In the paper a micromorph cell with a stable efficiency of 10.7 % (confirmed by ISE Freiburg) is reported.

Among sofar existing crystalline silicon-based solar cell manufacturing techniques, the application of microcrystalline silicon is a new promising way towards implementing thin-film silicon solar cells with a low temperature deposition. Microcrystalline silicon can, indeed, be deposited at temperatures as low as 220°C; hence, the way is here open to use cheap substrates as, e.g. plastic or glass. In the present paper, the development of single and tandem cells containing microcrystalline silicon is reviewed. As stated in previous publications, microcrystalline silicon technique has at present a severe drawback that has yet to be overcome: Its deposition rate for solar-grade material is about 2Å/s; in a more recent case 4.3 Å/s [2] could be obtained. In the present paper, using suitable mixtures of silane, hydrogen and argon, deposition rates of 9.4 Å/s are presented. Thereby the dominating plasma mechanism and the basic properties of resulting layers are described in detail. A first entirely microcrystalline cell deposited at 8.7 Å/s has an efficiency of 3.15%.

[Secondary aorto-enteral fistula as a cause of acute recurrent gastrointestinal bleeding, 20 years after living kidney donation]

Aorto-enteral fistulas (AEF) are a rare but life-threatening cause of acute gastrointestinal bleeding. Clinically, they can appear through massive haematochezia and haematemesis or as intermittent occult intestinal bleeding. The diagnostic procedure using endoscopy is often difficult but can contribute to making the correct diagnosis. We report on a patient who developed a secondary aorto-enteral fistula twenty years after a living kidney donation. The vascular surgery in combination with a chronic inflammatory reaction had resulted in the formation of a fistula between the renal artery stump and the duodenum. The inflammatory response was maintained by continuous treatment with methotrexate because of rheumatoid arthritis. Despite several total enteroscopies and diagnostic laparotomies, the fistula was seen on several occasions but was overlooked and misinterpreted in the absence of bleeding at first. The suspected fistula was finally marked with two endoclips and confirmed subsequently by radiological imaging by means of an abdominal CT scan.

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.

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.

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.

[Neuroendocrine tumors of the small bowels are on the rise: early tumors and their management]

Neuroendocrine tumors (NETs) of the small bowels are on the rise: in the US they have increased by 300-500% in the last 35 years. At the same time their prognosis has been much improved. Most NETs of the duodenum are nowadays detected "incidentally" and therefore recognized at an early stage. Duodenal NETs that are well differentiated, not larger than 10 mm in greatest dimension and limited to the mucosa/submucosa can be endoscopically resected. In NETs with a size between 10 mm and 20 mm the therapeutic strategy has to be individually discussed. Endoscopic ultrasound is the method of choice to determine tumor size and depth of infiltration. Surgery is indicated for well differentiated duodenal NETs greater than 20 mm, for localized sporadic gastrinomas and for localized poorly differentiated NE cancers. Surgery is also indicated for localized/regional ileal NETs. Advanced ileal NETs with a carcinoid syndrome are treated with stable somatostatin analogs. This treatment also significantly improves the (progression-free) survival in patients with metastatic NETs of the ileum. For optimal NET management tumor biology, type, localization and stage of the neoplasm as well as the individual situation of the patient have to be taken into account.

Double-balloon endoscopy for retrograde cholangiography in patients with choledochojejunostomy and Roux-en-Y reconstruction

BACKGROUND

Choledochojejunal anastomoses with Roux-en-Y reconstruction excludes the biliary tract from conventional endoscopic retrograde cholangiography (ERC) with standard endoscopes due to the length of the interposed small bowel segment. Double-balloon enteroscopy (DBE) facilitates deep insertion into the small bowel and may be used to perform ERC in these patients. In the present case series we report our experience with diagnostic and therapeutic double-balloon ERC in patients with choledochojejunostomy to a long Roux-en-Y loop previously unavailable for standard length endoscopes.

PATIENTS AND METHODS

Between December 2004 and May 2008 15 patients (mean age: 60.2 years) with choledochojejunal anastomosis underwent a total of 25 DBE-ERC procedures.

RESULTS

Cannulation of the bile ducts was achieved in 22 / 25 procedures (84 %). Twenty-one therapeutic interventions, including stone removal, biliary duct dilation, stent placement and removal of previously placed stents were performed during 16 procedures in 8 patients. The mean total duration time of the procedures was 74.6 +/- 25.0 minutes. Postinterventional self-limiting fever occurred after 4 procedures in 3 patients with cholangitis. After therapeutic interventions all patients had a significant drop of bilirubin levels and all except one patient were free of complaints (follow-up 10.4 +/- 8.6 months).

CONCLUSIONS

The DBE system permits diagnostic and therapeutic ERC in surgically modified anatomy, previously unavailable for endoluminal access. In our experience this procedure is safe and has a high success rate with a favourable patient outcome.

Computed virtual chromoendoscopy versus standard colonoscopy with targeted indigocarmine chromoscopy: a randomised multicentre trial

OBJECTIVE

Colonoscopy is the accepted gold standard for screening of neoplastic colorectal lesions, but the substantial miss rate remains a challenge. Computed virtual chromoendoscopy with the Fujinon intelligent colour enhancement (FICE) system is a new dyeless imaging technique that might allow higher rates of adenoma detection.

METHODS

This is a prospective randomised five tertiary care centre trial of colonoscopy in the FICE mode versus standard colonoscopy with targeted indigocarmine chromoscopy (control group) in consecutive patients attending for routine colonoscopy. Histopathology of detected lesions was confirmed by evaluation of endoscopic resection or biopsy specimens.

RESULTS

871 patients were enrolled, and 764 patients (344 female, mean age 64 years) were subjected to final analysis (368 in the FICE group, 396 in the control group). In total, 236 adenomas (mean of 0.64 per case) were detected in the FICE group and 271 adenomas (mean of 0.68 per case) in the control group (p = 0.92). There was no statistically significant difference in the percentage of patients with >or=1 adenoma between the control group (35.4%) and the FICE group (35.6%) (p = 1.0). For the differential diagnosis of adenomas and non-neoplastic polyps, the sensitivity of FICE (92.7%) was comparable with that of indigocarmine (90.4%) (p = 0.44).

CONCLUSIONS

At colonoscopy, adenoma detection rates are not improved by virtual chromoendoscopy with the FICE system compared with white light endoscopy with targeted indigocarmine spraying. However, FICE can effectively substitute for chromoscopy concerning the differentiation of neoplastic and non-neoplastic lesions.

"Dry biopsies" with spraying of dilute epinephrine optimize biopsy mapping of long segment Barrett's esophagus

BACKGROUND AND STUDY AIMS

For surveillance of Barrett's esophagus random stepwise four-quadrant biopsy (4QB) is recommended for detecting macroscopically occult neoplasias. Thorough performance of the systematic protocol is commonly hampered by poor visibility due to oozing from biopsy sites. Topical application of dilute epinephrine may prevent bleeding by vasoconstriction of superficial microvessels and might therefore enable "dry biopsy" sampling. The aim of this study was to examine the safety and efficacy of spraying dilute epinephrine for optimal 4QB mapping of Barrett's esophagus.

PATIENTS AND METHODS

In this prospective, double-blind trial 40 patients with known long segment Barrett's esophagus were randomly allocated to undergo spraying with either dilute epinephrine (1 : 20 000) (epinephrine group; n = 20) or saline (control group; n = 20) before 4QB sampling. During endoscopies patients received continuous monitoring of vital parameters. Endoscopists blinded to randomization assessed visibility scores during biopsy sampling. Additionally, electronically stored images of the Barrett's esophagus segment after 4QB sampling were evaluated by blinded assessors.

RESULTS

The mean length of Barrett's segments was 5.5 +/- 1.8 cm and the mean number of 4QBs was 12.5 +/- 3.6 with no statistically significant differences between control and epinephrine groups. Epinephrine spraying did not affect patients' vital parameters. Visualization ratings by endoscopists on site and by the assessors of the stored images were significantly better in the epinephrine compared with the control group (P < 0.05). Moreover, epinephrine spraying reduced the time for 4QB sampling (P = 0.015) and the mean number of saline flushes needed to maintain visibility (P = 0.0003).

CONCLUSIONS

The novel "dry biopsy" technique with spraying of dilute epinephrine is safe, and facilitates thorough performance of systematic 4QB mapping of Barrett's esophagus by improvement of visibility.

Severe paraneoplastic gastroparesis associated with anti-Hu antibodies preceding the manifestation of small-cell lung cancer

Gastroparesis is a common but challenging disorder which can be idiopathic or induced by a variety of underlying diseases, most frequently by diabetes, or post-surgical conditions of the upper abdomen. Clinicians must also consider rare causes of gastric motor dysfunction, such as collagen vascular disorders and paraneoplastic syndromes. Here we present the case of a patient with severe gastroparesis, who was admitted to our hospital for vomiting and weight loss of 25 kg within four months. Endoscopy showed a dilated fluid-filled stomach without peristalsis but no obstruction. High titres of anti-Hu antibodies were detected in patient's serum, supporting the diagnosis of severe paraneoplastic gastroparesis with chronic intestinal pseudo-obstruction. Fine-needle aspiration of suspicious mediastinal lymph nodes guided by endoscopic ultrasound revealed lymphatic metastases of a small-cell lung carcinoma. Jejunal tube feeding and chemotherapy with carboplatin and etoposide were initiated. Paraneoplastic gastrointestinal dysmotility is rare, however, clinicians should consider this differential diagnosis in otherwise unexplained gastrointestinal motor dysfunction. The pathophysiology of paraneoplastic gastroparesis, the diagnostic relevance of anti-Hu antibodies as well as therapeutic options are discussed.

ABRF ESRG 2006 study: Edman sequencing as a method for polypeptide quantitation

The Edman Sequencing Research Group (ESRG) designs studies on the use of Edman degradation for protein and peptide analysis. These studies provide a means for participating laboratories to compare their analyses against a benchmark of those from other laboratories that provide this valuable service. The main purpose of the 2006 study was to determine how accurate Edman sequencing is for quantitative analysis of polypeptides. Secondarily, participants were asked to identify a modified amino acid residue, N-epsilon-acetyl lysine [Lys(Ac)], present within one of the peptides. The ESRG 2006 peptide mixture consisted of three synthetic peptides. The Peptide Standards Research Group (PSRG) provided two peptides, with the following sequences: KAQYARSVLLEKDAEPDILELATGYR (peptide B), and RQAKVLLYSGR (peptide C). The third peptide, peptide C*, synthesized and characterized by ESRG, was identical to peptide C but with acetyl lysine in position 4. The mixture consisted of 20% peptide B and 40% each of peptide C and its acetylated form, peptide C*. Participating laboratories were provided with two tubes, each containing 100 picomoles of the peptide mixture (as determined by quantitative amino acid analysis) and were asked to provide amino acid assignments, peak areas, retention times at each cycle, as well as initial and repetitive yield estimates for each peptide in the mixture. Details about instruments and parameters used in the analysis were also collected. Participants in the study with access to a mass spectrometer (MALDI-TOF or ESI) were asked to provide information about the relative peak areas of the peptides in the mixture as a comparison with the peptide quantitation results from Edman sequencing. Positive amino acid assignments were 88% correct for peptide C and 93% correct for peptide B. The absolute initial sequencing yields were an average of 67% for peptide (C+C*) and 65.6 % for peptide B. The relative molar ratios determined by Edman sequencing were an average of 4.27 (expected ratio of 4) for peptides (C+C*)/B, and 1.49 for peptide C*/C (expected ratio of 1); the seemingly high 49% error in quantification of Lys(Ac) in peptide C* can be attributed to commercial unavailability of its PTH standard. These values compare very favorably with the values obtained by mass spectrometry.

Comparison of computed virtual chromoendoscopy and conventional chromoendoscopy with acetic acid for detection of neoplasia in Barrett's esophagus

BACKGROUND AND STUDY AIMS

Computed virtual chromoendoscopy (CVC) is a new imaging technique that enhances mucosal surface contrast and highlights the vascular pattern without the need for dye-spraying as in conventional chromoendoscopy. The aim of this prospective randomized pilot study with a crossover design was to compare CVC with conventional chromoendoscopy with acetic acid (CAA) for the detection of high grade intraepithelial neoplasia (HGIN) or early cancer in patients with Barrett's esophagus.

PATIENTS AND METHODS

57 patients with Barrett's esophagus (mean length 3.8 cm) and a history of HGIN/early cancer or suspected HGIN/early cancer were randomly allocated to undergo either CAA or CVC. All patients were re-examined with the alternative procedure at 4 - 6 weeks after the initial endoscopy. The two procedures were performed by five endoscopists, who were blinded to the findings of the other examination. At each examination, targeted biopsies were taken from all detected lesions, followed by random four-quadrant biopsies.

RESULTS

In 24/57 patients, 30 lesions with HGIN/early cancer were detected. The sensitivity of targeted biopsies for HGIN/early cancer on a 'per lesion' basis was 87 % (26/30) for both CAA and CVC. The positive predictive value was 39 % (26/66) for CAA and 37 % (26/70) for CVC. In the 'per patient' analysis, sensitivity was 83 % (20/24) and 92 % (22/24) for CAA and CVC, respectively ( P = 0.617). Stepwise random four-quadrant biopsies identified only one patient with HGIN/early cancer that was missed by both, CAA and CVC.

CONCLUSIONS

Computed virtual chromoendoscopy is a helpful adjunct for surveillance of Barrett's esophagus and appears to be as accurate as conventional chromoendoscopy in the detection of HGIN/early cancer.

Comparison of computed virtual chromoendoscopy and conventional chromoendoscopy with acetic acid for detection of neoplasia in Barrett's esophagus

BACKGROUND AND STUDY AIMS

Computed virtual chromoendoscopy (CVC) is a new imaging technique that enhances mucosal surface contrast and highlights the vascular pattern without the need for dye-spraying as in conventional chromoendoscopy. The aim of this prospective randomized pilot study with a crossover design was to compare CVC with conventional chromoendoscopy with acetic acid (CAA) for the detection of high grade intraepithelial neoplasia (HGIN) or early cancer in patients with Barrett's esophagus.

PATIENTS AND METHODS

57 patients with Barrett's esophagus (mean length 3.8 cm) and a history of HGIN/early cancer or suspected HGIN/early cancer were randomly allocated to undergo either CAA or CVC. All patients were re-examined with the alternative procedure at 4 - 6 weeks after the initial endoscopy. The two procedures were performed by five endoscopists, who were blinded to the findings of the other examination. At each examination, targeted biopsies were taken from all detected lesions, followed by random four-quadrant biopsies.

RESULTS

In 24/57 patients, 30 lesions with HGIN/early cancer were detected. The sensitivity of targeted biopsies for HGIN/early cancer on a 'per lesion' basis was 87 % (26/30) for both CAA and CVC. The positive predictive value was 39 % (26/66) for CAA and 37 % (26/70) for CVC. In the 'per patient' analysis, sensitivity was 83 % (20/24) and 92 % (22/24) for CAA and CVC, respectively ( P = 0.617). Stepwise random four-quadrant biopsies identified only one patient with HGIN/early cancer that was missed by both, CAA and CVC.

CONCLUSIONS

Computed virtual chromoendoscopy is a helpful adjunct for surveillance of Barrett's esophagus and appears to be as accurate as conventional chromoendoscopy in the detection of HGIN/early cancer.

Computed virtual chromoendoscopy: a new tool for enhancing tissue surface structures

We conducted a study of a newly developed "computed virtual chromoendoscopy" (CVC) system that enhances the contrast of the mucosal surface without the use of dyes. The CVC imaging technique is based on narrowing the bandwidth of the conventional endoscopic image arithmetically, using spectral estimation technology. Preliminary clinical tests comparing CVC-enhanced visualization of neoplastic and non-neoplastic lesions with images obtained by conventional endoscopy show that CVC enhances the vascular network as well as the pit pattern. CVC might therefore complement high-resolution endoscopy by facilitating the assessment of the nature and extent of gastrointestinal mucosal lesions.