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1.
Nature ; 619(7969): 317-322, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37438590

RESUMO

Plastic debris is thought to be widespread in freshwater ecosystems globally1. However, a lack of comprehensive and comparable data makes rigorous assessment of its distribution challenging2,3. Here we present a standardized cross-national survey that assesses the abundance and type of plastic debris (>250 µm) in freshwater ecosystems. We sample surface waters of 38 lakes and reservoirs, distributed across gradients of geographical position and limnological attributes, with the aim to identify factors associated with an increased observation of plastics. We find plastic debris in all studied lakes and reservoirs, suggesting that these ecosystems play a key role in the plastic-pollution cycle. Our results indicate that two types of lakes are particularly vulnerable to plastic contamination: lakes and reservoirs in densely populated and urbanized areas and large lakes and reservoirs with elevated deposition areas, long water-retention times and high levels of anthropogenic influence. Plastic concentrations vary widely among lakes; in the most polluted, concentrations reach or even exceed those reported in the subtropical oceanic gyres, marine areas collecting large amounts of debris4. Our findings highlight the importance of including lakes and reservoirs when addressing plastic pollution, in the context of pollution management and for the continued provision of lake ecosystem services.


Assuntos
Lagos , Plásticos , Poluição da Água , Abastecimento de Água , Ecossistema , Lagos/química , Plásticos/análise , Plásticos/classificação , Poluição da Água/análise , Poluição da Água/estatística & dados numéricos , Inquéritos e Questionários , Urbanização , Atividades Humanas
2.
J Sep Sci ; 44(19): 3700-3716, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34355502

RESUMO

Saliva is an attractive sampling matrix for measuring various endogenous and exogeneous substances but requires sample treatment prior to chromatographic analysis. Exploiting supercritical CO2 for both extraction and chromatography simplifies sample preparation, reduces organic solvent consumption, and minimizes exposure to potentially infectious samples, but has not yet been applied to oral fluid. Here, we demonstrate the feasibility and benefits of online supercritical fluid extraction coupled to supercritical fluid chromatography and single-quadrupole mass spectrometry for monitoring the model salivary tracer caffeine. A comparison of 13 C- and 32 S-labeled internal standards with external standard calibration confirmed the superiority of stable isotope-labeled caffeine over nonanalogous internal standards. As proof of concept, the validated method was applied to saliva from a magnetic resonance imaging study of gastric emptying. After administration of 35 mg caffeine via ice capsule, salivary levels correlated with magnetic resonance imaging data, corroborating caffeine's usefulness as tracer of gastric emptying (R2  = 0.945). In contrast to off-line methods, online quantification required only minute amounts of organic solvents and a single manual operation prior to online bioanalysis of saliva, thus demonstrating the usefulness of CO2 -based extraction and separation techniques for potentially infective biomatrices.


Assuntos
Cafeína/análise , Cromatografia com Fluido Supercrítico/métodos , Esvaziamento Gástrico/fisiologia , Espectrometria de Massas/métodos , Saliva/química , Humanos , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
4.
Diseases ; 11(3)2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37754304

RESUMO

An aneurysmal fibrous histiocytoma is a rare cutaneous soft-tissue tumour which accounts for approximately 0.06% of all dermatopathologies. Metastasis is exceedingly uncommon, to the point that there have only been eight reported cases in the scientific literature. We present the case of a 25-year-old male with a primary aneurysmal fibrous histiocytoma located in the nuchal region which exhibited rapid growth and abrupt ulceration over a short time span and showed signs of locoregional aggressive infiltration. A subsequent histopathological analysis confirmed the presence of diffuse solid and cystic pulmonary metastases. Further genetic sequencing verified LAMTOR1-PRKCD fusion. This case report seeks to review the existing literature on aneurysmal fibrous histiocytoma, discuss the challenges of differential diagnosis and propose standardised diagnostic criteria.

5.
Eur J Pharm Biopharm ; 184: 150-158, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36736963

RESUMO

Gastrointestinal fluid volumes are a crucial parameter for dissolution and absorption of orally taken medications. Most often 240 mL are used in clinical standard setups. Nonetheless, surveys in patient populations revealed dramatically lower volumes for intake of oral medications in real life and even in some clinical studies reduced fluid volumes are common. These reductions might have serious impact on pharmacokinetics. Thus, it was the aim of this study to compare the gastric emptying of 240 mL and 20 mL of water in 8 healthy volunteers. For investigation of gastric fluid volumes Magnetic Resonance Imaging with strongly T2 weighted sequences was used. Gastric emptying was additionally quantified via caffeine pharmacokinetics measured in saliva. The absolute gastric volumes after intake of 240 mL or 20 mL obviously differed by factor 10 but relative gastric emptying expressed as fraction per time was nearly comparable. Only slighter slower emptying after intake of 20 mL was observed. Salivary caffeine pharmacokinetics representing mass transfer from stomach to small intestine after intake of different volumes did not differ. The absorbed caffeine fraction and emptied gastric volume fraction correlated well after intake of 240 mL, but not after intake of 20 mL, indicating a higher influence of secretion on gastric volume measurements after intake of smaller volumes. Relative gastric emptying as measured with MRI and salivary caffeine method was only slightly delayed, thus transfer of orally administered drug fraction could be comparable even with lower fluid intake as can be seen by comparable caffeine pharmacokinetics. Nonetheless, the considerably reduced volumes might interfere with dissolution and absorption.


Assuntos
Cafeína , Esvaziamento Gástrico , Humanos , Água , Estômago , Imageamento por Ressonância Magnética/métodos
6.
Pharmaceutics ; 15(2)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36839650

RESUMO

Gastric water emptying as a critical parameter for oral drug absorption can be investigated by several imaging techniques or by the interpretation of pharmacokinetics of appropriate substances. Recently introduced salivary caffeine kinetics is a valuable tool, but the required caffeine abstinence limits its applicability. To avoid the caffeine abstinence, stable isotope-labeled caffeine might be used, but the representability and transferability of kinetics for evaluation of gastric emptying must be demonstrated. Thus, salivary caffeine pharmacokinetics were compared for naturally occurring 12C-caffeine and 13C3-caffeine after the administration of water under fasting conditions in six healthy young subjects. For this purpose, an ice capsule containing the two caffeine species was administered with 50 mL tap water. Gastric water emptying was simultaneously quantified using magnetic resonance imaging (MRI). Gastric emptying of 50 mL of water could be successfully evaluated. The salivary caffeine kinetics of 13C3- and 12C-caffeine were nearly congruent and showed good linear correlations in all subjects, with a mean correlation coefficient of 0.96 in pooled data. Thus, the substitution of natural 12C caffeine with stable isotope-labeled 13C3-caffeine offers the opportunity for broader application of the salivary caffeine gastric emptying technique and increases the robustness of the method against environmental contamination with caffeine.

7.
Obes Facts ; 15(5): 703-710, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35973414

RESUMO

INTRODUCTION: Adiposity and excessive weight are on the rise in western industrialized countries. In cases where conservative measures fail and surgical interventions are not (yet) desired, gastric balloon therapy has proven to be a safe and reversible endoscopic method. METHODS: Aside from weight progression under gastric balloon therapy and by using MRI, our research paper describes the behavior of different abdominal body fat compartments at the beginning and at the end of the gastric balloon therapy. Additionally, the volume of the left liver lobe as well as the fill volume and performance of the gastric balloon were analyzed over the duration of treatment. For assessing potential impacts of weight reduction on the muscle mass, we determined the area of the m. psoas on a comparable cross-sectional area at the beginning and at the end of the therapy. RESULTS: We were able to verify a significant reduction of the layer of subcutaneous fat, adipose capsule of the kidney, and intra-abdominal fatty tissue during the therapy. The volume of the left liver lobe was shrinking in addition to a muscle loss during the balloon therapy. The volume of the gastric balloon remained stable (not hyperinflation). There were variable gas bubbles in the gastric balloon. CONCLUSION: The gastric balloon is a temporary and successful option for weight reduction by reducing body fat, liver volume, but also muscle mass.


Assuntos
Balão Gástrico , Humanos , Redução de Peso , Obesidade/terapia , Gordura Abdominal , Imageamento por Ressonância Magnética , Gordura Intra-Abdominal
8.
Pharmaceutics ; 13(6)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199636

RESUMO

There are no methods for specific local application of active substances to the mucosa of the esophagus to treat eosinophilic esophagitis or other esophageal diseases. This publication describes the principal in vivo functionality and acceptance of a novel modular drug delivery concept, called EsoCap system, by 12 healthy volunteers. For the first time, the EsoCap system enables targeted placement on the esophageal mucosa of a mucoadhesive polymer film. Acceptance was determined by means of a standardized questionnaire after administration and functionality of the device by MRI scans. Two different setups of the EsoCap system were tested: one setup with a density of 0.4 g/cm3 and one with a density of 1.0 g/cm3. Acceptability of the dosage form was also confirmed in addition to functionality, by measuring the applied film length. It was found that acceptance of the variant with the higher density was significantly better. This novel drug delivery technology could enable a targeted, local and long-lasting therapy of the esophagus for the first time, depending on the polymer film used.

9.
Visc Med ; 37(5): 418-425, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34722725

RESUMO

PURPOSE: The implantation of a gastric balloon (also known as intragastric balloon) is an established and reversible endoscopic procedure for adiposity therapy. Structural changes of the stomach wall are expected to occur with gastric balloon implantation; however, until now these changes have rarely been investigated. METHODS: We compared the histological structure of the stomach wall after gastric-sleeve resection in a group of patients following gastric balloon implantation and a group without previous gastric balloon implantation. RESULTS: Following gastric balloon implantation, the tunica muscularis was found to be significantly thicker than without gastric balloon implantation. The enlarging of the tunica muscularis is not caused by hyperplasia of the leiomyocytes, but by hypertrophy of the leiomyocytes and an increase in collagen fibers (fibrosis). CONCLUSION: A longer-lasting hypertrophy of the tunica muscularis, particularly in the corpus, should be taken into account when surgical treatment follows gastric balloon implantation. The staple suture height should be adjusted to the altered tissue composition since reduced tissue elasticity must be expected due to fibrosis.

10.
J Control Release ; 327: 1-7, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-32781172

RESUMO

For the therapy of esophageal diseases such as eosinophilic esophagitis, there are no possibilities of local targeted therapy. This publication describes a novel, innovative drug delivery concept, that enables a targeted, long-lasting administration of drug substances to the esophageal mucosa. In addition to a comprehensive in-vitro characterization of the dosage form, this work includes a proof-of-concept study with healthy volunteers, which shows the functionality and acceptance of this novel drug delivery concept. This novel drug delivery technology enables for the first time a targeted, local and long-lasting therapy of the esophagus.


Assuntos
Esofagite Eosinofílica , Sistemas de Liberação de Medicamentos , Mucosa Esofágica , Humanos
13.
Spine (Phila Pa 1976) ; 42(4): 224-231, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-28207657

RESUMO

STUDY DESIGN: We prospectively evaluated adjacent disc levels after anterior cervical discectomy and arthroplasty (ACDA) using kinematic magnetic resonance imaging (MRI) and plain functional radiographs. OBJECTIVE: ACDA is an established treatment for degenerative cervical disc disease. The objective of this study was to evaluate the use of kinematic MRI for assessing the range of motion (ROM) before and after ACDA compared with plain functional radiographs and to evaluate adjacent degenerative disc disease (aDDD) at mid-term follow-up. SUMMARY OF BACKGROUND DATA: Twenty patients (12 females, 8 males; median age 45.6 ±â€Š6.9 yrs) treated by ACDA (BryanDisc; Medtronic, MN) underwent plain functional radiography and kinematic MRI of the cervical spine at 3 T before and 6 and 24 months after surgery. METHODS: A sagittal T2-weighted (T2w) 2D turbo spin echo (TSE) sequence and a 3D T2w dataset with secondary axial reconstruction were acquired. Signal intensity of all nonoperated discs was measured in regions of interest (ROI). Disc heights adjacent to the operated segment were measured. ROM was evaluated and compared with plain functional radiographs. Clinical outcome was evaluated using the visual analog scale (VAS) for head, neck and radicular pain, and the neck disability index (NDI). RESULTS: Mean ROM of the cervical spine on functional plain radiographs was 21.25 ±â€Š8.19°, 22.29 ±â€Š4.82°, and 26.0 ±â€Š6.9° preoperatively and at 6-month and 24-month follow-up, respectively. Mean ROM at MRI was 27.1 ±â€Š6.78°, 29.45 ±â€Š9.51°, and 31.95 ±â€Š9.58°, respectively. There was a good correlation between both techniques. Follow-up examinations demonstrated no signs of progressive degenerative disc disease of adjacent levels. All patients had clinical improvement up to 24 months after surgery. CONCLUSION: After ACDA, kinematic MRI allows evaluation of the ROM with excellent correlation to plain functional radiographs. Mid-term follow-up after ACDA is without evidence of progressive DDD of adjacent segments. LEVEL OF EVIDENCE: 3.


Assuntos
Artroplastia , Fenômenos Biomecânicos/fisiologia , Vértebras Cervicais/cirurgia , Discotomia , Degeneração do Disco Intervertebral/diagnóstico por imagem , Disco Intervertebral/cirurgia , Adulto , Artroplastia/métodos , Discotomia/métodos , Feminino , Seguimentos , Humanos , Degeneração do Disco Intervertebral/cirurgia , Masculino , Pessoa de Meia-Idade , Radiografia/métodos , Amplitude de Movimento Articular/fisiologia , Fusão Vertebral/métodos , Substituição Total de Disco/métodos , Resultado do Tratamento
15.
PLoS One ; 11(4): e0153595, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27110719

RESUMO

OBJECTIVES: To investigate changes in the fat content of abdominal compartments and muscle area during weight loss using confounder-adjusted chemical-shift-encoded magnetic resonance imaging (MRI) in overweight diabetics. METHODS: Twenty-nine obese diabetics (10/19 men/women, median age: 59.0 years, median body mass index (BMI): 34.0 kg/m2) prospectively joined a standardized 15-week weight-loss program (six weeks of formula diet exclusively, followed by reintroduction of regular food with gradually increasing energy content over nine weeks) over 15 weeks. All subjects underwent a standardized MRI protocol including a confounder-adjusted chemical-shift-encoded MR sequence with water/fat separation before the program as well at the end of the six weeks of formula diet and at the end of the program at 15 weeks. Fat fractions of abdominal organs and vertebral bone marrow as well as volumes of visceral and subcutaneous fat were determined. Furthermore, muscle area was evaluated using the L4/L5 method. Data were compared using the Wilcoxon signed-rank test for paired samples. RESULTS: Median BMI decreased significantly from 34.0 kg/m2 to 29.9 kg/m2 (p < 0.001) at 15 weeks. Liver fat content was normalized (14.2% to 4.1%, p < 0.001) and vertebral bone marrow fat (57.5% to 53.6%, p = 0.018) decreased significantly throughout the program, while fat content of pancreas (9.0%), spleen (0.0%), and psoas muscle (0.0%) did not (p > 0.15). Visceral fat volume (3.2 L to 1.6 L, p < 0.001) and subcutaneous fat diameter (3.0 cm to 2.2 cm, p < 0.001) also decreased significantly. Muscle area declined by 6.8% from 243.9 cm2 to 226.8 cm2. CONCLUSION: MRI allows noninvasive monitoring of changes in abdominal compartments during weight loss. In overweight diabetics, weight loss leads to fat reduction in abdominal compartments, such as visceral fat, as well as liver fat and vertebral bone marrow fat while pancreas fat remains unchanged.


Assuntos
Complicações do Diabetes/diagnóstico por imagem , Ingestão de Energia , Obesidade/diagnóstico por imagem , Programas de Redução de Peso , Humanos , Imageamento por Ressonância Magnética , Obesidade/complicações , Obesidade/dietoterapia , Estudos Prospectivos
16.
PLoS One ; 9(2): e88867, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24558438

RESUMO

OBJECTIVES: To evaluate body weight-tailored contrast medium (CM) administration for computed tomography angiography (CTA) of the craniocervical vessels. METHODS: Institutional review board approval was obtained, and all patients gave written informed consent. Sixty patients were consecutively assigned to one of three dose groups (20 patients per group) with CM doses of Visipaque 270® (iodixanol 270 mg/ml) tailored to body weight at doses of 1.5, 1.0, or 0.5 ml/kg. Region-of-interest (ROI) analysis of maximum enhancement (ME) was conducted, and signal-to-noise-ratios (SNR) and contrast-to-noise-ratios (CNR) were calculated. Retrospective comparison was performed with three matched control groups examined with a standard CM dose (80 ml of Visipaque 270®). Image quality was rated by two neuroradiologists blinded to the CM dose used. Interrater reliability was calculated using kappa statistics. RESULTS: Body weight/BMI and ME were inversely correlated in the three control groups receiving the standard dose (r = -0.544/-0.597/-0.542/r = -0.358/r = -0.424/r = -0.280). Compared to standard dose, 1.5 ml/kg produced higher ME, SNR, and CNR in the anterior circulation (p≤0.038), 1.0 ml/kg had higher ME in cervical and medium-sized cerebral arteries (p≤0.034), and 0.5 ml/kg had lower ME, SNR and CNR for medium-sized cerebral arteries (p≤0.049). ME, SNR, and CNR were the same for 1.5 ml/kg and 1.0 ml/kg (p≥0.24), and both had higher values compared to 0.5 ml/kg (p≤0.043/p≤0.028). In patients with BMI>25, 1.5 ml/kg and 1.0 ml/kg produced higher ME than standard dose (p<0.001/p = 0.008), but ME in patients with BMI>25 did not differ between group 1 and group 2 (p = 0.673). In patients with BMI≤25, 1.5 ml/kg and 1.0 ml/kg produced ME comparable to standard dose (p = 0.132/p = 0.403). Regardless of patient weight, 0.5 ml/kg yielded lower ME than standard dose (p = 0.019/0.002). CONCLUSIONS: Craniocervical CTA with a body weight-tailored CM dose of 1.0 ml/kg (270 mg iodine/ml) reduces iodine load in patients weighing <80 kg while producing ME similar to standard dose and improves ME in patients with BMI>25.


Assuntos
Angiografia/métodos , Peso Corporal , Meios de Contraste/administração & dosagem , Sistema Nervoso/irrigação sanguínea , Medicina de Precisão/métodos , Tomografia Computadorizada por Raios X/métodos , Idoso , Índice de Massa Corporal , Feminino , Humanos , Injeções , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Estudos Prospectivos , Doses de Radiação , Razão Sinal-Ruído , Ácidos Tri-Iodobenzoicos/administração & dosagem
20.
Vet Clin Pathol ; 39(3): 306-16, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20727123

RESUMO

BACKGROUND: Testing for canine blood types other than dog erythrocyte antigen 1.1 (DEA 1.1) is controversial and complicated by reagent availability and methodology. OBJECTIVES: The objectives of this study were to use available gel column technology to develop an extended blood-typing method using polyclonal reagents for DEA 1.1, 1.2, 3, 4, 7, and Dal and to assess the use of gel columns for cross-matching. METHODS: Dogs (43-75) were typed for DEA 1.1, 1.2, 3, 4, 7, and Dal. METHODS included tube agglutination (Tube) using polyclonal reagents, a commercially available DEA 1.1 gel column test kit (Standard-Gel) using monoclonal reagent, and multiple gel columns (Extended-Gel) using polyclonal reagents. Blood from 10 recipient and 15 donor dogs was typed as described above and cross-matched using the gel column technique. RESULTS: Of 43 dogs typed for DEA 1.1, 23, 25, and 20 dogs were positive using Standard-Gel, Extended-Gel, and Tube, respectively. Typing for DEA 1.2 was not achievable with Extended-Gel. For 75 dogs typed for DEA 3, 4, and 7, concordance of Extended-Gel with Tube was 94.7%, 100%, and 84%, respectively. Dal, determined only by Extended-Gel, was positive for all dogs. Post-transfusion major cross-matches were incompatible in 10 of 14 pairings, but none were associated with demonstrable blood type incompatibilities. CONCLUSIONS: Gel column methodology can be adapted for use with polyclonal reagents for detecting DEA 1.1, 3, 4, 7, and Dal. Agglutination reactions are similar between Extended-Gel and Tube, but are more easily interpreted with Extended-Gel. When using gel columns for cross-matching, incompatible blood cross-matches can be detected following sensitization by transfusion, although in this study incompatibilities associated with any tested DEA or Dal antigens were not found.


Assuntos
Antígenos de Grupos Sanguíneos/imunologia , Tipagem e Reações Cruzadas Sanguíneas/veterinária , Cães/sangue , Eritrócitos/imunologia , Testes de Hemaglutinação/veterinária , Animais , Cães/imunologia , Testes de Hemaglutinação/métodos , Imunodifusão/métodos , Imunodifusão/veterinária , Sensibilidade e Especificidade
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