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1.
Endosc Int Open ; 11(10): E952-E962, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37828974

ABSTRACT

Background and study aims For non-dysplastic Barrett's Esophagus (BE) patients, guidelines recommend endoscopic surveillance every 3 to 5 years with four-quadrant random biopsies every 2 cm of BE length. Adherence to these guidelines is low in clinical practice. Pooling BE surveillance endoscopies on dedicated endoscopy lists performed by dedicated endoscopists could possibly enhance guideline adherence, detection of visible lesions, and dysplasia detection rates (DDRs). Patients and methods Data were used from the ACID-study (Netherlands Trial Registry NL8214), a prospective trial of BE surveillance in the Netherlands. BE patients with known or previously treated dysplasia were excluded. Guideline adherence, detection of visible lesions, and DDRs were compared for patients on dedicated and general endoscopy lists. Results A total of 1,244 patients were included, 318 on dedicated lists and 926 on general lists. Endoscopies on dedicated lists showed significantly higher adherence to the random biopsy protocol (85% vs. 66%, P <0.01) and recommended surveillance intervals (60% vs. 47%, P <0.01) compared to general lists. Detection of visible lesions (8.8% vs. 8.1%, P =0.79) and DDRs were not significantly different (6.9% and 6.6%, P =0.94). None (0.0%) of the patients scheduled on dedicated lists and 10 (1.1%) on general lists were diagnosed with esophageal adenocarcinoma ( P =0.07). In multivariable analysis, dedicated lists were significantly associated with biopsy protocol adherence and adherence to surveillance interval recommendations with odds ratios of 4.45 (95% confidence interval [CI] 2.07-9.57) and 1.64 (95% CI 1.03-2.61), respectively. Conclusions Dedicated endoscopy lists are associated with better adherence to the random biopsy protocol and surveillance interval recommendations.

2.
J Immunol Methods ; 507: 113307, 2022 08.
Article in English | MEDLINE | ID: mdl-35760096

ABSTRACT

Systemic chronic inflammation and immune dysfunction are recognized as drivers of the development of non-AIDS related comorbidities (NARCs) in people living with HIV (PLHIV). In order to lower the risk of NARCs, it is critical to elucidate what is the contribution of alterations in the composition and function of circulating immune cells to NARCs-related pathogenesis. Findings from previous immunophenotyping studies in PLHIV are highly heterogeneous and it is not fully understood to what extent phenotypic changes on immune cells play a role in the dysregulated inflammatory response observed. In this study, three flow cytometry panels were designed and standardized to phenotypically and functionally identify the main circulating immune cell subsets in PLHIV. To reduce variability, up to 10 markers out of the approximately 20 markers in each panel were used in a custom dry format DURA Innovations (LUCID product line). Intra-assay precision tests performed for the selected cell subsets showed that the three panels had a %CV below 18% for percent of positive cells and the MFI (mean fluorescent intensity) of lineage markers. Our reported pipeline for immunophenotypic analysis facilitated the discrimination of 1153 cell populations, providing an integrated overview of circulating innate and adaptative immune cells as well as the cells' functional status in terms of activation, exhaustion, and maturation. When combined with unsupervised computational techniques, this standardized immunophenotyping approach may support the discovery of novel phenotypes with clinical relevance in NARCs and demonstrate future utility in other immune-mediated diseases.


Subject(s)
HIV Infections , Biomarkers/analysis , Flow Cytometry/methods , HIV Infections/diagnosis , Humans , Immunophenotyping
3.
Sci Rep ; 6: 31135, 2016 08 10.
Article in English | MEDLINE | ID: mdl-27507165

ABSTRACT

Future quantum optical chips will likely be hybrid in nature and include many single-photon emitters, waveguides, filters, as well as single-photon detectors. Here, we introduce a scalable optical localization-selection-lithography procedure for wiring up a large number of single-photon emitters via polymeric photonic wire bonds in three dimensions. First, we localize and characterize nitrogen vacancies in nanodiamonds inside a solid photoresist exhibiting low background fluorescence. Next, without intermediate steps and using the same optical instrument, we perform aligned three-dimensional laser lithography. As a proof of concept, we design, fabricate, and characterize three-dimensional functional waveguide elements on an optical chip. Each element consists of one single-photon emitter centered in a crossed-arc waveguide configuration, allowing for integrated optical excitation and efficient background suppression at the same time.

4.
Digestion ; 83(1-2): 41-5, 2011.
Article in English | MEDLINE | ID: mdl-20847562

ABSTRACT

BACKGROUND: Previous reports correlated microalbuminuria with disease activity in patients with Crohn's disease (CD). The aim of the present study is to determine the value of microalbuminuria as a marker for relapses in quiescent CD. METHODS: In a 1-year prospective maintenance trial with oral budesonide in patients with CD in remission, microalbuminuria was measured at randomization, after 2, 6 and 12 months, plus at the time of a relapse. The association of microalbuminuria with the course of disease was analyzed with logistic regression analysis. Time-dependent Cox regression was undertaken to study the association between microalbuminuria and relapse. RESULTS: We included a total of 139 patients. At randomization, microalbuminuria was present in 8 patients. During a 1-year follow-up, 29 patients relapsed and in 11% (3/29), microalbuminuria was present during the relapse. We found no statistically significant association between microalbuminuria and relapse (odds ratio 0.92, 95% confidence interval (CI) 0.76-1.13). Time-dependent Cox regression analysis also revealed no statistical predictive value for microalbuminuria (hazard ratio 1.29, 95% CI 0.37-4.39, p = 0.68). CONCLUSION: Microalbuminuria was moderately prevalent in quiescent CD patients, but it could not be associated with disease characteristics or the type of medication before randomization, nor as a predictor for relapses.


Subject(s)
Albuminuria/etiology , Crohn Disease/diagnosis , Crohn Disease/urine , Adult , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/therapeutic use , Biomarkers/urine , Budesonide/administration & dosage , Budesonide/therapeutic use , Crohn Disease/drug therapy , Female , Humans , Logistic Models , Male , Middle Aged , Predictive Value of Tests , Proportional Hazards Models , Prospective Studies , Recurrence , Young Adult
5.
J Synchrotron Radiat ; 17(2): 158-65, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20157266

ABSTRACT

Humic acids (HA) have a high binding capacity towards traces of toxic metal cations, thus affecting their transport in aquatic systems. Eu(III)-HA aggregates are studied by synchrotron-based scanning transmission X-ray microscopy (STXM) at the carbon K-edge and laser scanning luminescence microscopy (LSLM) at the (5)D(0) --> (7)F(1,2) fluorescence emission lines. Both methods provide the necessary spatial resolution in the sub-micrometre range to resolve characteristic aggregate morphologies: optically dense zones embedded in a matrix of less dense material in STXM images correspond to areas with increased Eu(III) luminescence yield in the LSLM micrographs. In the C 1s-NEXAFS of metal-loaded polyacrylic acid (PAA), used as a HA model compound, a distinct complexation effect is identified. This effect is similar to trends observed in the dense fraction of HA/metal cation aggregates. The strongest complexation effect is observed for the Zr(IV)-HA/PAA system. This effect is confirmed by quantum chemical calculations performed at the ab initio level for model complexes with different metal centres and complex geometries. Without the high spatial resolution of STXM and LSLM and without the combination of molecular modelling with experimental results, the different zones indicating a ;pseudo'-phase separation into strong complexing domains and weaker complexing domains of HA would never have been identified. This type of strategy can be used to study metal interaction with other organic material.


Subject(s)
Europium/chemistry , Humic Substances/analysis , Microscopy, Confocal/methods , Cations/chemistry , Luminescence , Microscopy/methods , Quantum Theory
6.
Endoscopy ; 40(10): 799-805, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18828075

ABSTRACT

BACKGROUND AND STUDY AIMS: We have recently proposed a classification of mucosal morphology in Barrett's esophagus based on three criteria: regularity of mucosal pattern, regularity of vascular pattern, and presence of abnormal blood vessels. We aimed to evaluate the interobserver agreement with the proposed mucosal morphology classification and to assess the additional value of narrow band imaging (NBI) over high resolution white light endoscopy (HR-WLE). PATIENTS AND METHODS: Five international experts in the field of Barrett's imaging and seven community endoscopists with no expertise in this field independently evaluated magnified still images from 50 areas, obtained with HR-WLE and NBI, in Barrett's esophagus patients. Visual analogue scales (VAS) were used for scoring imaging quality. Interobserver agreement for mucosal morphology and yield for identifying early neoplasia were assessed. RESULTS: Imaging qualities of NBI were rated more highly than HR-WLE, when evaluated separately as well as in a side-by-side comparison. The interobserver agreement ranged from 0.40 to 0.56 and did not significantly differ between expert and non-expert endoscopists. The overall yield for correctly identifying images of early neoplasia was 81 % for HR-WLE, 72 % for NBI and 83 % for HR-WLE + NBI, with no significant difference between experts and non-experts. CONCLUSION: Interobserver agreement for the classification of mucosal morphology was moderate. Although NBI was rated more highly than HR-WLE for imaging quality, this did not result in improved interobserver agreement or increased yield for identifying early neoplasia in Barrett's esophagus. This applied to non-expert as well as expert endoscopists.


Subject(s)
Barrett Esophagus/pathology , Carcinoma/pathology , Endoscopy , Esophageal Neoplasms/pathology , Mucous Membrane/pathology , Precancerous Conditions/pathology , Barrett Esophagus/classification , Clinical Competence , Humans , Image Enhancement , Light , Microscopy , Mucous Membrane/blood supply , Observer Variation , Reproducibility of Results , Retrospective Studies
7.
Ned Tijdschr Geneeskd ; 152(31): 1737-42, 2008 Aug 02.
Article in Dutch | MEDLINE | ID: mdl-18727606

ABSTRACT

A 79-year-old woman presented with complaints of upper abdominal pain, nausea and vomiting since a few days. Laboratory tests showed no abnormalities except for some indications of an inflammation. Based on the medical history, physical examination and findings from radiological examination, initially the diagnosis was 'chronic pancreatitis with formation ofa pseudocyst caused by alcohol abuse'. After one week the patient developed cholestatic liver function disorders with elevated serum pancreatic enzymes. A CT scan of the abdomen showed a dilated gallbladder and progression of the cystic lesion in the pancreatic head with compression of the distal common bile duct. An endoscopic retrograde cholangiopancreatography was performed and the findings fitted a diagnosis of an intraductal papillary mucinous neoplasm. Differentiation between an inflammatory or neoplastic origin of cystic lesions in the pancreas can be difficult. There is a risk ofmisdiagnosing a cystic neoplasm for a pseudocyst. This may lead to delays in making the correct diagnosis.


Subject(s)
Cholangiopancreatography, Endoscopic Retrograde/methods , Cystadenoma, Mucinous/diagnosis , Pancreatic Neoplasms/diagnosis , Pancreatic Pseudocyst/diagnosis , Acute Disease , Aged , Cystadenoma, Mucinous/surgery , Diagnosis, Differential , Female , Humans , Pancreatic Neoplasms/surgery , Pancreatic Pseudocyst/surgery , Time Factors , Treatment Outcome
8.
J Microsc ; 229(Pt 2): 223-7, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18304076

ABSTRACT

A triangular nanoaperture in an aluminium film was used previously as a probe in a scanning near-field optical microscope to image single fluorescent molecules with an optical resolution down to 30 nm. The high-resolution capability of the triangular aperture probe is because of a highly confined spot of the electric near field which emerges at an edge of the aperture, when the incident light is polarized perpendicular to this edge. Previous numerical calculations of the near-field distribution of a triangular aperture in a planar metal film using the field susceptibility technique yielded a nearly quantitative agreement with the experimental results. Using the same numerical technique we now explored the possibility for a further confinement of the electric near field and an increase in its intensity by modifications of the form of a triangular aperture. By introducing a kink on an edge pointing into the aperture, an arrow-shaped aperture is formed with one convex and three concave metal corners. It turns out that this form leads to a substantial further confinement of the near-field intensity at the convex corner. By extending the wings of this arrow-shaped aperture a further 5-fold increase of the intensity can be obtained without a deterioration of the confined spot.

9.
Clin Nutr ; 25(5): 765-72, 2006 Oct.
Article in English | MEDLINE | ID: mdl-16698130

ABSTRACT

BACKGROUND & AIMS: Patients with head and neck carcinomas often loose a significant percentage of weight, which correlates with the complication rate. Only limited information is available on the moment and extent of weight loss and energy intake in time and the relation with type of treatment. The aim of this study was to describe the moment and extent of weight loss and nutritional energy intake in patients with tumors in oral cavity, oropharynx and hypopharynx during diagnosis, treatment and revalidation. METHODS: An observational, prospective study on weight changes and nutritional intake in these patients was carried out during diagnosis, treatment and revalidation in relation to the type of treatment. RESULTS: Forty-seven patients successfully completed the study. A significant difference in mean bodyweight was found for patients treated by radiotherapy during treatment (-3.3 kg, P=0.01) and the early revalidation period (-3.4 kg, P=0.01) and for patients treated with surgery during diagnoses (-1.5 kg, P=0.001) and early revalidation period (1.6 kg, P=0.02). Overall patients lowered their energy intake by 122 kcal/day followed by a significant increase in energy intake during revalidation 326 kcal/day (P=0.04). CONCLUSIONS: The radiotherapy and the concomitant radio-chemotherapy group lost most body weight during treatment and early revalidation. All treatment groups experienced a decrease in energy intake during treatment followed by a significant increase during revalidation.


Subject(s)
Cachexia/etiology , Carcinoma/metabolism , Combined Modality Therapy/adverse effects , Energy Intake , Head and Neck Neoplasms/metabolism , Weight Loss , Antineoplastic Agents/adverse effects , Antineoplastic Agents/therapeutic use , Carcinoma/complications , Carcinoma/diagnosis , Carcinoma/therapy , Female , Head and Neck Neoplasms/complications , Head and Neck Neoplasms/diagnosis , Head and Neck Neoplasms/therapy , Humans , Male , Middle Aged , Nutrition Assessment , Prospective Studies , Radiotherapy/adverse effects , Risk Factors , Surveys and Questionnaires , Treatment Outcome
10.
Inflamm Bowel Dis ; 11(11): 972-6, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16239842

ABSTRACT

BACKGROUND: Case reports concerning irreversible renal failure caused by 5-aminosalicylates (5-ASA) have been published. The aim of this study was to investigate the effect of long-term use of 5-ASA on renal function in patients with Crohn's disease (CD). METHODS: This was a retrospective survey in 200 consecutive outpatients with CD. Endogenous creatinine clearance (ECC) was estimated from serum creatinine with the Cockroft and Gault formula. The first ECC was chosen close to the start of 5-ASA and the second was the most recent ECC available. RESULTS: In 153 patients (59 men and 94 women), sufficient data were available for analysis. The interval between ECCs was 11 years, with a mean exposure to 5-ASA of 8.6 years. The cumulative dose of 5-ASA amounted to 9 kg. The ECC declined 0.3 +/- 5 mL/min/yr (from 100 +/- 25 to 92 +/- 28 mL/min; P < 0.01). In a multiple linear regression model, duration of the interval was a significant predictor for change in ECC (P < 0.0001), but cumulative dose of 5-ASA was not predictive (P = 0.30). No interstitial nephritis was reported, and in the 8 patients with the largest decline in ECC, comorbidity causing renal function impairment was present. CONCLUSIONS: The mean decline in ECC of 0.3 mL/min/yr in patients with CD does not exceed the decline expected from physiologic aging. Furthermore, the cumulative dose of 5-ASA was not a predictor for change in renal function. However, as interstitial nephritis caused by 5-ASA may rarely occur, we still advocate measurements of serum creatinine before and during treatment.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Crohn Disease/drug therapy , Mesalamine/adverse effects , Mesalamine/therapeutic use , Renal Insufficiency/chemically induced , Adult , Aging , Creatinine/metabolism , Female , Health Surveys , Humans , Male , Middle Aged , Nephritis, Interstitial/chemically induced , Retrospective Studies
11.
Support Care Cancer ; 13(10): 790-6, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16186995

ABSTRACT

We conducted a prospective, randomised, double-blinded, placebo-controlled pilot study of parenteral nutrition (PN) supplemented with 0.57 g/kg glutamine-dipeptide in a homogeneous group of 32 allogeneic stem cell transplant (SCT) recipients to determine its effect on mucosal barrier injury (MBI). All patients had been prepared with idarubicin, cyclophosphamide and total body irradiation. PN (by continuous infusion) started on SCT day -6 for a median of 19 days. MBI measured by sugar permeability tests, daily mucositis score, daily gut score, and citrulline concentrations was not reduced by glutamine-dipeptide. However, the daily gut score was significantly lower for the glutamine group on SCT +7 (p = 0.001) whilst citrulline was lower (p = 0.03) for the placebo group on SCT day +21. Albumin was significantly lower in the placebo group on SCT day +21 (32+/-4 versus 37+/-3, p = 0.001) whilst CRP was higher (74+/-48 versus 34+/-38, p = 0.003). Other transplant-related complications (infections, acute graft-versus-host disease) were less common although this did not reach statistical significance nor translate into a reduced length of hospital stay or lower mortality. These results indicate that it would be worthwhile conducting a larger trial to see whether or not giving glutamine-dipeptide reduces the 100-day allogeneic transplant-related complications.


Subject(s)
Glutamine/administration & dosage , Stem Cell Transplantation , Transplantation, Homologous , Adolescent , Adult , Double-Blind Method , Female , Glutamine/therapeutic use , Humans , Infusions, Parenteral , Male , Middle Aged , Netherlands , Pilot Projects , Placebos
12.
Neth J Med ; 63(7): 275-7, 2005.
Article in English | MEDLINE | ID: mdl-16093580

ABSTRACT

We report a female patient who repeatedly developed pancreatitis after trimethoprim-sulfamethoxazole (TMP/SMX) use. During childhood she had undergone an ureterosigmoidostomy after which she had been on TMP/SMX 480 mg daily as prophylaxis for pyelonephritis for many years. The patient presented with abdominal pain caused by acute pancreatitis. No other cause, except for TMP/SMX use, could be identified. A causal relationship was confirmed by relapse of the pancreatitis after rechallenge. Our case is unique in demonstrating that acute pancreatitis related to the use of TMP/SMX may occur even after long-term treatment. We advise that the medication is discontinued immediately if a causal relationship with pancreatitis is suspected.


Subject(s)
Anti-Infective Agents, Urinary/adverse effects , Pancreatitis, Acute Necrotizing/chemically induced , Trimethoprim, Sulfamethoxazole Drug Combination/adverse effects , Anti-Infective Agents, Urinary/therapeutic use , Endoscopy, Gastrointestinal , Female , Follow-Up Studies , Humans , Middle Aged , Pancreatitis, Acute Necrotizing/diagnosis , Pyelonephritis/prevention & control , Recurrence , Time Factors , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use
13.
Ned Tijdschr Geneeskd ; 149(8): 385-90, 2005 Feb 19.
Article in Dutch | MEDLINE | ID: mdl-15751316

ABSTRACT

Intestinal failure is characterised by inability of the intestine to absorb sufficient nutrients to maintain the integrity and function of the body. This can be caused by malabsorption due to too short an intestine or an abnormality of the mucosa, or by a severe motility disorder. In addition to dietary measures, the prescription of total parental nutrition (TPN) at home is sometimes necessary. This treatment is a burden on the patient and the risk of complications must be reduced to a minimum. The risks of long-term parenteral nutrition can be limited and the quality of the provision of services can be increased if the co-ordination is in the hands of a centre for home parenteral nutrition. In the Netherlands there are two centres for home-TPN: the St Radboud University Medical Centre in Nijmegen and the University Medical Centre (AMC) in Amsterdam. In both children and adults, the most common indications are the short bowel syndrome and motility disorders. However, the syndromes that cause this are clearly different in the different age groups. Parenteral nutrition can be given for long periods of time. A large variety of complications can occur, related especially to the equipment or the nutrients. When the nutrition is given via a central venous catheter, then sepsis is a serious and possibly life-threatening complication. In case of administration via an arteriovenous shunt, thrombosis of the shunt is the most frequent problem. If the treatment by means of home-TPN fails, then transplantation of the small intestine should be considered.


Subject(s)
Intestinal Diseases/therapy , Parenteral Nutrition, Home Total/methods , Adult , Child , Esophageal Motility Disorders/therapy , Humans , Intestinal Diseases/physiopathology , Intestines/physiopathology , Intestines/transplantation , Parenteral Nutrition, Home Total/adverse effects , Short Bowel Syndrome/therapy , Treatment Outcome
14.
Ned Tijdschr Geneeskd ; 149(8): 391-8, 2005 Feb 19.
Article in Dutch | MEDLINE | ID: mdl-15751317

ABSTRACT

Small bowel transplantation for intestinal failure is no longer an experimental procedure, but an accepted treatment for patients where total parenteral nutrition (TPN) therapy for intestinal failure is unsuccessful. Early referral for screening for small bowel transplantation should be considered in patients with permanent intestinal failure who have occlusion of more than 2 major veins, frequent line-related septic episodes, impairment of liver function or an unacceptable quality of life. With the increased experience in post-transplant patient care and newer forms of induction (thymoglobulin, IL-2 receptor antagonists) and maintenance (tacrolimus) therapies, the 1-year graft survival has increased to 65% for isolated and to 59% for liver/small bowel transplantation and is further improving. Rejection, bacterial, fungal and viral (Cytomegalovirus, Epstein-Barr-virus) infections, post-transplant lymphoproliferative disease and graft versus host disease are the most common complications after intestinal transplantation. Although most of the long-term survivors are TPN-independent and have a good quality of life, the risk of the procedure and long-term adverse effects ofimmunosuppressive medication limits small bowel, or liver/small bowel transplantation only to patients with severe complications of TPN therapy.


Subject(s)
Intestine, Small/transplantation , Short Bowel Syndrome/surgery , Adult , Child , Graft Rejection , Graft Survival , Humans , Liver/physiology , Parenteral Nutrition, Home Total , Postoperative Complications , Quality of Life , Short Bowel Syndrome/therapy , Treatment Outcome
15.
Biophys J ; 88(5): 3681-8, 2005 May.
Article in English | MEDLINE | ID: mdl-15695631

ABSTRACT

Scanning near-field optical microscopy (SNOM) circumvents the diffraction limit of conventional light microscopy and is able to achieve optical resolutions substantially below 100 nm. However, in the field of cell biology SNOM has been rarely applied, probably because previous techniques for sample-distance control are less sensitive in liquid than in air. Recently we developed a distance control based on a tuning fork in tapping mode, which is also well-suited for imaging in solution. Here we show that this approach can be used to visualize single membrane protein complexes kept in physiological media throughout. Nuclear envelopes were isolated from Xenopus laevis oocytes at conditions shown recently to conserve the transport functions of the nuclear pore complex (NPC). Isolated nuclear envelopes were fluorescently labeled by antibodies against specific proteins of the NPC (NUP153 and p62) and imaged at a resolution of approximately 60 nm. The lateral distribution of epitopes within the supramolecular NPC could be inferred from an analysis of the intensity distribution of the fluorescence spots. The different number densities of p62- and NUP153-labeled NPCs are determined and discussed. Thus we show that SNOM opens up new possibilities for directly visualizing the transport of single particles through single NPCs and other transporters.


Subject(s)
Biophysics/methods , Microscopy, Fluorescence/methods , Nuclear Envelope/ultrastructure , Oocytes/metabolism , Xenopus laevis/metabolism , Animals , Binding Sites , Biological Transport , Biophysics/instrumentation , Cell Nucleus/metabolism , Cytoplasm/metabolism , Epitopes/chemistry , Green Fluorescent Proteins/metabolism , Membrane Glycoproteins/biosynthesis , Normal Distribution , Nuclear Pore/metabolism , Nuclear Pore Complex Proteins/biosynthesis , Nuclear Pore Complex Proteins/chemistry
16.
Opt Express ; 13(26): 10688-96, 2005 Dec 26.
Article in English | MEDLINE | ID: mdl-19503284

ABSTRACT

A triangular nano-aperture in an aluminum film was used as a probe in a scanning near-field optical microscope (SNOM) to image single fluorescent molecules with an optical resolution down to 30 nm. The differently oriented molecules were employed as point detectors to map the vectorial components of the electric field distribution at the illuminated triangular aperture. The good agreement of the experimental results with numerical simulations enabled us to determine both the field map at a triangular aperture and the exact orientations of the probing molecules.

17.
Dig Dis Sci ; 48(7): 1355-9, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12870795

ABSTRACT

Osteoporosis is frequent in Crohn's disease. The aim of the study was to assess the rate of bone loss over time retrospectively and the influence of disease-related factors on bone loss. Twenty-nine patients (8 male), admitted for repeated bone mineral density assessments (BMD) were enrolled. BMD measured by dual energy x-ray absoptiometry was expressed in grams per square centimeter, and as sex- and age-matched Z score. The mean interval between BMD assessments was 41 months, during which period 27 patients used corticosteroids (mean dose 8.6 g) and 21 patients some form of bone protective medication. Initial Z scores at a mean age of 41 years were significantly below zero (spine -1.6 +/- 1.4; femur -1.4 +/- 1.4). Over time, no change in absolute BMD was observed accompanied by an improvement in Z scores. At the same time, an increase in body weight and a decrease in erythrocyte sedimentation rate (ESR) was observed. Multilinear regression analysis demonstrated change in ESR as independent predictor for change in femoral Z score. In conclusion, low BMD is frequent in Crohn's disease, but decline of BMD over time was not found, despite ongoing use of corticosteroids.


Subject(s)
Bone Density/physiology , Crohn Disease/physiopathology , Osteoporosis/metabolism , Adult , Anti-Inflammatory Agents/pharmacology , Body Weight/physiology , Bone Density/drug effects , Crohn Disease/complications , Crohn Disease/metabolism , Female , Follow-Up Studies , Humans , Longitudinal Studies , Male , Middle Aged , Osteoporosis/complications , Osteoporosis/drug therapy , Retrospective Studies , Steroids , Time Factors
18.
Neth J Med ; 61(4): 105-10, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12852718

ABSTRACT

In patients with inflammatory bowel disease, assessment of disease activity is important in order to monitor and adjust therapy. In individual patients, disease evaluation is largely based on subjective symptoms. However, for disease evaluation in clinical trials, an objective and reproducible disease activity index is needed. At present, a number of activity indices are available for Crohn's disease and for ulcerative colitis. These indices may be distinguished in more subjective clinical indices, more objective endoscopic and histological indices, and in indices with combinations of both subjective and objective parameters. In the design of a new clinical trial, an appropriate disease activity index should be selected which is based on the patient selection criteria and the aims of the study.


Subject(s)
Colitis, Ulcerative/diagnosis , Crohn Disease/diagnosis , Severity of Illness Index , Clinical Trials as Topic , Humans , Patient Selection
19.
Scand J Gastroenterol ; 38(5): 522-5, 2003 May.
Article in English | MEDLINE | ID: mdl-12795463

ABSTRACT

BACKGROUND: Gastrin plays an important role in the regulation of gastric acid secretion in humans. Tumour necrosis factor alpha (TNF-alpha) stimulates gastrin release from antral G cells in vitro. The aim was to determine whether gastrin release decreases in patients with Crohn disease treated with monoclonal antibody to TNF-alpha. METHODS: Twenty-five consecutive patients with Crohn disease (10 M, 15 F; 18 with fistulas) were treated with a single intravenous infusion of the monoclonal antibody to TNF-alpha, infliximab, at a dose of 5 mg/kg. Basal and bombesin stimulated gastrin was measured after an overnight fast immediately before and 2 weeks after infliximab. Helicobacter pylori status was determined by serology. RESULTS: Twenty-two patients were H. pylori-negative. Basal plasma gastrin was 21 (16-26) pmol/L before and 19 (15-25) pmol/L after infliximab (NS). Bombesin stimulated gastrin decreased from 49 (40-62) pmol/L before to 36 (33-59) pmol/L (P < 0.005) 2 weeks after infliximab. CONCLUSION: Gastrin release in response to bombesin decreases in patients with Crohn disease treated with infliximab.


Subject(s)
Antibodies, Monoclonal/pharmacology , Crohn Disease/drug therapy , Crohn Disease/metabolism , Gastrin-Secreting Cells/drug effects , Gastrins/biosynthesis , Gastrointestinal Agents/pharmacology , Adult , Aged , Antibodies, Monoclonal/therapeutic use , Bombesin/metabolism , Female , Gastrin-Secreting Cells/metabolism , Gastrointestinal Agents/therapeutic use , Humans , Infliximab , Male , Middle Aged , Tumor Necrosis Factor-alpha/immunology
20.
J Microsc ; 210(Pt 3): 288-93, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12787101

ABSTRACT

The applications of scanning near-field optical microscopy to biological specimens under physiological conditions have so far been very rare since common techniques for a probe-sample distance control are not as well suited for operation in liquid as under ambient conditions. We have shown previously that our own approach for a distance control, based on a short aperture fibre probe and a tuning fork as force sensor in a tapping mode, works well even on soft material in water. By means of an electronic self-excitation circuit, which compensates for changes of the resonance frequency due to evaporation of liquid, the stability of the force feedback has now been further improved. We present further evidence for the excellent suitability of the tapping-mode-like distance control to an operation in liquid, for example, by force-imaging of double-stranded DNA. Moreover, we demonstrate that a nuclear envelope in liquid can be imaged with a high optical resolution of approximately 70 nm without affecting its structural integrity. Thereby, single nuclear pores in the nuclear envelope with a nearest neighbour distance of approximately 120 nm have been optically resolved for the first time.


Subject(s)
Nuclear Envelope/ultrastructure , Oocytes/ultrastructure , Xenopus laevis/growth & development , Animals , Female , Fiber Optic Technology , Microscopy, Scanning Probe/instrumentation , Microscopy, Scanning Probe/methods , Water
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