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OBJECTIVES: The deprivation amplification hypothesis postulates that the socially disadvantaged are exposed to further structural deprivation by their residential environment such that social inequalities are therefore amplified. To date, no publication has investigated deprivation amplification solely using playgrounds; the present health geography study investigates this hypothesis with regard to the availability of playgrounds in a typical large German city. STUDY DESIGN: Between July 2016 and January 2017, all playgrounds in the city of Mannheim, Germany, were identified and evaluated by systematic audits. The playground attributes such as availability, accessibility, surface area, and provided amenities were operationalized using well-established, validated instruments. METHODS: Geo-information about playgrounds was digitalized in ArcGIS 10.2-10.4 and linked to socioeconomic indicators on the meso-level, that is, on the level of 44 social areas. Availability and accessibility of playgrounds were quantified by calculating kernel density and Euclidean distance, respectively. Playground surface area and equipment provided were linked to the number of children and adolescents in the particular social area. The association between availability and accessibility of playgrounds and area-level indicators were assessed using bivariate and multiple Poisson regressions on the meso-level. RESULTS: In the city of Mannheim, which covers 145 km2 and is home to 311,000 inhabitants, 271 playgrounds were identified. Bivariate and multiple analyses showed no association between availability and accessibility of playgrounds and area-level indicators. However, significant negative associations were found in the bivariate analyses between playground area and amenities provided per child and various area-level indicators, but not in multiple models. CONCLUSIONS: Children are provided with different opportunities to play and to be physically active, depending upon the population density of their social neighborhood. At least in our study area, many socially disadvantaged families are forced to move to densely populated areas for economic reasons. Against that background, the phenomenon of 'deprivation amplification' was not confirmed for availability and accessibility of playgrounds but for playground area and number of amenities provided.
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Planejamento Ambiental/estatística & dados numéricos , Exercício Físico , Parques Recreativos/estatística & dados numéricos , Características de Residência/estatística & dados numéricos , Adolescente , Criança , Cidades , Alemanha , Humanos , Fatores SocioeconômicosRESUMO
Oncology is a rapidly developing field with a growing number of publications every year. The main goal of this survey was to learn more about the information needs of oncologists and general practitioners. Data were collected using a standardised questionnaire developed in collaboration with the German Cancer Society (Deutsche Krebsgesellschaft) and the German Association of General Practitioners (Deutscher Hausärzteverband). A total of 495 questionnaires could be evaluated. Medical congresses were the preferred source of information for all participants. General practitioners preferred textbooks, while oncologists preferred journals and the Internet (all p < .001). Reasons for a lack of confidence during patient consultation were lack of time (60% of participants), lack of knowledge (61% of general practitioners and 26% of oncologists) and lack of data (>50%). Oncologists felt more confident in searching scientific databases than general practitioners did. Both groups required rapid access to transparent information. For general practitioners, reviews and comments by experts helped to put new information in the context of cancer treatment. Oncologists and general practitioners showed significantly different information needs and different ways to access specific information. In order to better integrate general practitioners while simultaneously serving the needs of oncologists, a database that is up to date, rapidly accessible and does not incur high costs would be helpful.
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Acesso à Informação , Clínicos Gerais/psicologia , Neoplasias/terapia , Oncologistas/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Alemanha , Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde/psicologia , Humanos , Serviços de Informação , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades , Satisfação Pessoal , Adulto JovemRESUMO
The rate of biosynthesis of procollagen IV, the principal collagen of basement membranes, and the concentration of specific RNAs coding for procollagen IV were measured in neonatal rat lungs. Both decreased sharply at birth and then recovered again a few days later. The supramolecular assembly of procollagen IV was followed in neonatal rat, mouse, and chick lungs, which actively elaborate endothelial and alveolar basement membranes, and in chick embryo gizzard which is rich in smooth muscle. The tetramer of four procollagen IV molecules linked covalently through their amino ends was isolated as an assembly intermediate from all these tissues. While noncovalent association of the carboxyl ends of two procollagen IV molecules occurred readily, the subsequent establishment of covalent cross-links was substantially slower in the junctional complexes of the carboxyl ends than of the amino ends. Both disulfide bonds and other, unidentified covalent links formed. The six component carboxyl peptides of a junctional complex became progressively covalently linked into two kinds of carboxyl peptide pairs. We conclude that both amino-linked tetramers and carboxyl-linked dimers of procollagen IV molecules are intermediates in the biological assembly of the collagen networks of these basement membranes.
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Pró-Colágeno/metabolismo , Fatores Etários , Animais , Animais Recém-Nascidos , Membrana Basal/metabolismo , DNA/genética , Regulação da Expressão Gênica , Moela não Aviária/metabolismo , Técnicas Imunológicas , Pulmão/metabolismo , Substâncias Macromoleculares , Fragmentos de Peptídeos/análise , Pró-Colágeno/biossíntese , Pró-Colágeno/genética , RatosRESUMO
Drosophila laminin was isolated from the medium of Drosophila Kc cell cultures. It was purified by velocity sedimentation, gel filtration, and chromatography. Drosophila laminin is a disulfide-linked molecule consisting of three chains with apparent molecular masses of 400, 215, and 185 kD. In electron micrographs, it has the cross-shaped appearance with globular domains characteristic of vertebrate laminin with closely similar dimensions. The amino acid composition and lectin-binding properties of Drosophila laminin are given. Polyclonal antibodies to Drosophila laminin were prepared and their specificity was established. In developing embryos immunofluorescence staining was detected between 6 and 8 h of development; and in sections of 8-9-h and older embryos immunostaining was seen at sites where basement membranes are present surrounding internal organs, muscles, underlying the hypodermal epithelium, and in the nervous system. Basement membrane staining was also seen in larva and adults. Cells from Drosophila embryos dissociated at the cellular blastoderm stage were grown in culture and some specific, differentiated cells synthesized laminin after several hours of culture as shown by immunofluorescence. The significance of the evolutionary conservation of the structure of this basement membrane component is discussed.
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Drosophila melanogaster/análise , Laminina/análise , Aminoácidos/análise , Animais , Complexo Antígeno-Anticorpo , Cromatografia de Afinidade , Cromatografia em Gel , Cromatografia por Troca Iônica , Imunoglobulina G , Laminina/isolamento & purificação , Microscopia Eletrônica , Peso MolecularRESUMO
To precisely ablate tumor in radiation therapy, it is important to locate the tumor position in real time during treatment. However, respiration-induced tumor motions are difficult to track. They are semi-periodic and exhibit variations in baseline, frequency and fundamental pattern (oscillatory amplitude and shape). In this study, we try to decompose the above-mentioned components from discrete observations in real time. Baseline drift, frequency (equivalently phase) variation and fundamental pattern change characterize different aspects of respiratory motion and have distinctive clinical indications. Furthermore, smoothness is a valid assumption for each one of these components in their own spaces, and facilitates effective extrapolation for the purpose of estimation and prediction. We call this process 'profiling' to reflect the integration of information extraction, decomposition, processing and recovery. The proposed method has three major ingredients: (1) real-time baseline and phase estimation based on elliptical shape tracking in augmented state space and Poincaré sectioning principle; (2) estimation of the fundamental pattern by unwarping the observation with phase estimate from the previous step; (3) filtering of individual components and assembly in the original temporal-displacement signal space. We tested the proposed method with both simulated and clinical data. For the purpose of prediction, the results are comparable to what one would expect from a human operator. The proposed approach is fully unsupervised and data driven, making it ideal for applications requiring economy, efficiency and flexibility.
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Processamento de Imagem Assistida por Computador/métodos , Modelos Biológicos , Movimento , Respiração , Humanos , Neoplasias/fisiopatologia , Neoplasias/radioterapia , Fatores de TempoRESUMO
Part C of the guideline is preceded by Part B General Pharmacology IJCPT. 2008; 46: 600 - 617. Included in Part C are practical guidelines for improving the therapy of some age-specific diseases and problems commonly encountered in general practice. The article in this issue is dedicated to the therapy of Dementia and M. Parkinson. Further guidelines for the other age specific diseases and problems named above will be published in the following issues of IJCPT. An important feature of these guidelines are the inclusion of Levels of Evidence and of the Strength of Recommendations for the therapy which are shown when reliable studies are available. (For both see levels of evidence at the end of this article.).
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Demência/tratamento farmacológico , Medicina de Família e Comunidade , Transtornos Parkinsonianos/tratamento farmacológico , Idoso , Terapia Cognitivo-Comportamental , Demência/diagnóstico , Demência/fisiopatologia , Medicina Baseada em Evidências , Humanos , Transtornos Parkinsonianos/diagnóstico , Transtornos Parkinsonianos/fisiopatologia , Padrões de Prática MédicaRESUMO
The part "Special pharmacology of the aged" of this guideline contains recommendations for typical conditions in the family doctors practice: in the January issue 2009 dementia and Morbus Parkinson, in this issue osteoporosis and urinary incontinence and in the next issue rectal incontinence and obstipation. This issue of the IJCPT contains the third part of the Pharmacotherapy guidelines for the aged by family doctors for family doctors. Part 3: Osteoporosis and urinary incontinence. Osteoporosis is a systematic disease characterized by low bone mass and declining bone structure. Exercise, adequate diet, nicotine abstinence as well as reduction of alcohol consumption may counteract the progression of the disease. Osteoporosis manifests in bone fractures with minimal trauma. Attention must be given to the risk of falling, e.g., by avoiding drugs that increase the risk of falling: e.g., psychotropic agents, analgesic drugs and antiarrhythmic agents. Specific osteoporosis medication e.g. calcium, vitamin D, biphosphonates and SERM (selective estrogen receptor modulators) is evaluated by family doctors according to indication, dosage, contraindications, long-term therapy and nature of any fracture. Duration of therapy is at least 3 - max. 5 years followed by reassessment of indication. There are 3 types of urine incontinence (urge-, stress-, and overflow-incontinence). Another standardization of urinary incontinence follows dysfunctions of the pelvic floor: detrusor muscle-dependent, due to sphincter spasm, prostate gland dependent. Urge incontinence with a dysfunction of the detrusor muscle is the most common type. Mixed types are frequent. Non-drug measures (e.g. pelvic muscle training, bladder training, toilet training are first choice treatments. Drug therapy (estrogen, imipramine) are without proven effect.
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Medicina de Família e Comunidade , Osteoporose/tratamento farmacológico , Incontinência Urinária/reabilitação , Idoso , Cálcio/uso terapêutico , Difosfonatos/uso terapêutico , Terapia de Reposição de Estrogênios , Medicina Baseada em Evidências , Feminino , Humanos , Masculino , Osteoporose/diagnóstico , Osteoporose/fisiopatologia , Modalidades de Fisioterapia , Padrões de Prática Médica , Moduladores Seletivos de Receptor Estrogênico/uso terapêutico , Incontinência Urinária/fisiopatologia , Incontinência Urinária/terapia , Vitamina D/uso terapêuticoRESUMO
Physiological changes in old age: loss of muscle mass; reduction in bone mass; percentage of fat increased; lower amount of body water; lack of thirst; diminishing kidney function (caution: sufficient intake of fluids: 1.5-2 l and moderate intake of protein 8 g/kg body weight); reduced secretion of digestive enzymes, delayed emptying of stomach (which means premature feeling of repletion). Lack of fluids and nutrition is therefore likely. Daily intake of 1,500 kcal and 1.5-2 l fluids is necessary. An indicator for malnutrition is low body weight (defined for persons older than 65 years of age as BMI < 20) and a protein serum concentration < 35 g/l. Malnutrition carries an increased risk of infections, falling and fractures, bed sores, anemia, decompensation of chronic diseases. 10-20% of subjects over 80 years of age show signs of malnutrition, 40-60% of subjects in care institutions or hospitals. There are regressive changes in the locomotor and the nervous system of the elderly which have an effect on physical fitness. These changes reduce strength, endurance, proprioceptive capacity (e.g. coordination, balance) and mobility. Exercise in the old and very old should increase skeletal muscle strength in particular and improve coordination and balance. Regular physical exercise and moderate training has a positive effect on mobility and thereby improves independence and reduces falls. Moreover, it has a positive effect on cardiac output, maximum heart rate, stroke volume and the risk of a cardiovascular event and mortality can be reduced. Moreover, moderate physical exercise is often more effective in treating chronic disease than drug therapy e.g. heart failure, coronary heart disease, asthma/COPD, stroke, diabetes mellitus Type 2, degenerative diseases of the joints, depression and others. Examine cardiovascular risks in persons over the age of 50 before beginning physical exercise. Avoid maximum stress levels.
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Exercício Físico , Necessidades Nutricionais , Padrões de Prática Médica , Idoso , Medicina de Família e Comunidade , Humanos , Avaliação Nutricional , Distúrbios Nutricionais/fisiopatologia , Distúrbios Nutricionais/terapia , Estado Nutricional , Resistência Física , Treinamento ResistidoRESUMO
This article contains the 4th part of the Pharmacotherapy Guidelines for the Aged by Family Doctors for Family Doctors. Part 4 is dedicated to fecal incontinence and chronic constipation. The diagnostic categories are divided according to severity and dysfuntion of bowel and pelvic floor, sphincter and neural control. Therapy is also outlined. Importance is given to patient history, in particular the use and abuse of drugs that stimulate peristalsis and promote constipation. Therapy in the elderly is guided by the maxim: use the most conservative therapy possible, where stool training has considerable importance. Drug therapy based on symptoms can only be recommended when non-drug measures continue to fail. In patients with fecal incontinence: 1) opiates (which reduce colonic motility), 2) loperamide (which has the capacity to dilate the rectum) and 3) anion exchangers which have the capacity to prevent cholonic diarrhea. In patients with chronic obstipation: 1) trial: stool-forming laxatives (ensure intake of sufficient amount of fluids) 2) trial: laxatives with an osmotic effect and 3) trial: stimulating laxatives (beware abuse, do not use in cases of acute abdomen).
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Constipação Intestinal/tratamento farmacológico , Incontinência Fecal/tratamento farmacológico , Padrões de Prática Médica , Idoso , Doença Crônica , Constipação Intestinal/etiologia , Constipação Intestinal/terapia , Medicina de Família e Comunidade , Incontinência Fecal/etiologia , Incontinência Fecal/terapia , Humanos , Laxantes/uso terapêuticoRESUMO
It is important to monitor tumor movement during radiotherapy. Respiration-induced motion affects tumors in the thorax and abdomen (in particular, those located in the lung region). For image-guided radiotherapy (IGRT) systems, it is desirable to minimize imaging dose, so external surrogates are used to infer the internal tumor motion between image acquisitions. This process relies on consistent correspondence between the external surrogate signal and the internal tumor motion. Respiratory hysteresis complicates the external/internal correspondence because two distinct tumor positions during different breathing phases can yield the same external observation. Previous attempts to resolve this ambiguity often subdivided the data into inhale/exhale stages and restricted the estimation to only one of these directions. In this study, we propose a new approach to infer the internal tumor motion from external surrogate signal using state augmentation. This method resolves the hysteresis ambiguity by incorporating higher-order system dynamics. It circumvents the segmentation of the internal/external trajectory into different phases, and estimates the inference map based on all the available external/internal correspondence pairs. Optimization of the state augmentation is investigated. This method generalizes naturally to adaptive on-line algorithms.
Assuntos
Adenocarcinoma/radioterapia , Carcinoma de Células Pequenas/radioterapia , Carcinoma de Células Escamosas/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Movimento/fisiologia , RespiraçãoRESUMO
Recent developments in modulation techniques enable conformal delivery of radiation doses to small, localized target volumes. One of the challenges in using these techniques is real-time tracking and predicting target motion, which is necessary to accommodate system latencies. For image-guided-radiotherapy systems, it is also desirable to minimize sampling rates to reduce imaging dose. This study focuses on predicting respiratory motion, which can significantly affect lung tumours. Predicting respiratory motion in real-time is challenging, due to the complexity of breathing patterns and the many sources of variability. We propose a prediction method based on local regression. There are three major ingredients of this approach: (1) forming an augmented state space to capture system dynamics, (2) local regression in the augmented space to train the predictor from previous observation data using semi-periodicity of respiratory motion, (3) local weighting adjustment to incorporate fading temporal correlations. To evaluate prediction accuracy, we computed the root mean square error between predicted tumor motion and its observed location for ten patients. For comparison, we also investigated commonly used predictive methods, namely linear prediction, neural networks and Kalman filtering to the same data. The proposed method reduced the prediction error for all imaging rates and latency lengths, particularly for long prediction lengths.
Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/radioterapia , Modelos Biológicos , Movimento , Radioterapia Conformacional/métodos , Mecânica Respiratória , Simulação por Computador , Humanos , Análise de RegressãoRESUMO
PURPOSE: Modern cancer care is provided in highly specialized structures as certificated centres and comprehensive cancer center, as well as specialized practices. In contrast, the position of the general practitioner (GP) is less well characterised and there is a lack of information about his importance in the care for cancer patients. The aim of our survey was to assess the role of GPs in German cancer care from patients' perspective. METHODS: In several steps we developed a standardized anonymous questionnaire in cooperation with the German Association of General Practitioners and the Federal Association of German Self-Help Groups. This questionnaire was used in a print and an online version and distributed by the self-help organizations to their members. RESULTS: Seven hundred and forty participants took part in the survey, 66.5% women and 30.1% men. 71% had visited the GP during cancer therapy and 34.5% discussed decisions concerning diagnostics and therapy with him. The most relevant reasons to visit the GP during cancer therapy were to get a blood test (63.3%), comorbidities (42.7%) and complaints and side effects (38.3%). For the latter, most often a detailed discussion ensued (57%), fooled by a prescription (37.7%). In 63.4% the GP offered support when patients had some questions or worries concerning their cancer. Yet, 17% of the patients reported that the GP did not try to help. 85.5% of the participants thought that it is important that their GP is informed about the therapy on a regular basis. For 77.0%, a simultaneous care provided by the GP is important or very important. CONCLUSION: Our survey points to the importance of the GP during cancer therapy from the patient's point of view. Patients want their GP to take an active part in the cancer therapy. Furthermore, early integration of the GP may also enhance early integration of palliative care and also help family members and caregivers. A strategy to integrate GPs is the establishment of shared care models, in which GPs are supported by specialists and get additional training in cancer care.
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Clínicos Gerais , Neoplasias/terapia , Satisfação do Paciente , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/psicologia , Atenção Primária à Saúde/métodos , Inquéritos e Questionários , Adulto JovemRESUMO
UNLABELLED: This study compares the ability of 241Am and 99mTc to estimate 201Tl attenuation maps while minimizing the loss in the precision of the emission data. METHODS: A triple-head SPECT system with either an 241Am or 99mTc line source opposite a fan-beam collimator was used to estimate attenuation maps of the thorax of an anthropomorphic phantom. Linear attenuation values at 75 keV for 201Tl were obtained by linear extrapolation of the measured values from 241Am and 99mTc. RESULTS: Lung and soft-tissue estimates from both isotopes showed excellent agreement to within 3% of the measured values for 201Tl. Linear extrapolation did not yield satisfactory estimates for bone from either 241Am (+11.7%) or 99mTc (-15.3%). Patient data were used to estimate the dependence of crosstalk on patient size. Contamination from 201Tl in the transmission window was 5-6 times greater for 241Am compared to 99mTc, while the contamination in the 201Tl data in the transmission-emission detector head (head 1) was 4-5 times greater for 99mTc compared to 241Am. No contamination was detected in the 201Tl emission data of heads 2 and 3 from 241Am, whereas the 99mTc produced a small crosstalk component giving a signal-to-crosstalk ratio near 20:1. Measurements with a fillable chest phantom estimated the mean error introduced into the data from the removal of the crosstalk. CONCLUSION: Based on the measured data, 241Am is a suitable transmission source for simultaneous transmission-emission tomography for 201Tl cardiac studies.
Assuntos
Amerício , Coração/diagnóstico por imagem , Tecnécio , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Constituição Corporal , Feminino , Humanos , Masculino , Modelos Estruturais , Tomografia Computadorizada de Emissão de Fóton Único/métodosRESUMO
UNLABELLED: This study evaluates the effect of attenuation correction on regional myocardial tracer distributions defined by 201TI cardiac perfusion SPECT images obtained from healthy volunteers and patients with coronary heart disease. METHODS: A three-detector SPECT system equipped with an 241Am line source and a fanbeam collimator was used for simultaneous transmission/emission (201TI) tomography on 40 patients and 10 normal volunteers. Uncorrected emission images were reconstructed using filtered backprojection (FBP), whereas the attenuation corrected images were iteratively reconstructed with a regularized, least-squares algorithm utilizing the attenuation map computed from the transmission data. Both sets of images were reoriented into short-axis and vertical long-axis slices. Circumferential profile analysis was applied to both datasets of short-axis slices. RESULTS: The normal volunteers demonstrated improved homogeneity in tracer distribution. For a basal short-axis slice, the lateral-to-posterior activity ratio improved from 1.17 +/- 0.12 for FBP to 1.01 +/- 0.07. Basal attenuation appeared properly compensated as the peak basal-to-apical slice activity gradient along the posterior-inferior wall changed from 1.15 +/- 0.12 for FBP to 1.01 +/- 0.09. The apex of the attenuation corrected images showed a significant decrease in activity relative to the base which appeared consistent with anatomic wall thinning. For the inferior and basal septal regions, the defect severity was slightly less in the attenuation corrected images, but the defects were more sharply defined compared to the FBP image defects. CONCLUSION: These results indicate that attenuation correction is clinically feasible and accurately corrects for photon attenuation. Clinical validation, however, is necessary to define the diagnostic benefits.
Assuntos
Coração/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Doença das Coronárias/diagnóstico por imagem , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Modelos Estruturais , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada por Raios X/instrumentação , Tomografia Computadorizada por Raios X/métodosRESUMO
UNLABELLED: In the search for an in vivo marker of cholinergic neuronal integrity, we extended to human use the tracer (-)-5-[123I]iodobenzovesamicol (IBVM). METHODS: IBVM, an analog of vesamicol that binds to the acetylcholine transporter on presynaptic vesicles, was prepared with specific activity greater than 1.11 x 10(9) MBq mmole-1. After intravenous injection of [123I]IBVM, body distribution studies (n = 5) and brain SPECT studies (n = 5) were performed on normal human subjects (n = 10). SPECT images of the brain were collected sequentially over the first 4.5 hr following injection, and again 18 hr later. Data were realigned and transformed to stereotaxic coordinates, and localized activities were extracted for tracer kinetic analysis. The cerebral tracer input function was determined from metabolite-corrected radial arterial blood samples. The best data fit was obtained using a three-compartment model, including terms reflecting cerebral blood volume, exchange of free tracer between plasma and brain and specific binding. RESULTS: Dissociation of bound tracer was negligible for up to 4 hr. For the fitted parameters reflecting transport (K1) and binding site density index (k3), coefficients of variation were approximately 8% in cortical regions of interest. Relative distributions corresponded well with postmortem immunohistochemical values reported for the acetylcholine-synthesizing enzyme choline acetyltransferase, k3 (IBVM binding site density index), and tracer activity distribution at 22 hr, but not at 4 hr after injection. CONCLUSION: SPECT imaging of [123I]IBVM succeeds as an in vivo measure of cholinergic neuronal integrity and should be useful for the study of cerebral degenerative processes such as Alzheimer's disease.
Assuntos
Encéfalo/diagnóstico por imagem , Radioisótopos do Iodo , Neurônios/diagnóstico por imagem , Fenciclidina/análogos & derivados , Piperidinas , Terminações Pré-Sinápticas/diagnóstico por imagem , Tetra-Hidronaftalenos , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Doença de Alzheimer/diagnóstico por imagem , Animais , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Neurônios/química , Terminações Pré-Sinápticas/química , Ratos , Ratos Sprague-Dawley , Distribuição TecidualRESUMO
This paper analyzes the tradeo between spatial resolution and noise for simple pinhole imaging systems with photon-counting detectors. We consider image recovery algorithms based on density estimation methods using kernels that are based on apodized inverse filters. This approach allows a continuous-object, continuous-data treatment of the problem. The analysis shows that the pinhole size that minimizes the estimate variance for a specied reconstructed spatial resolution is directly proportional to that spatial resolution. For a Gaussian pinhole, the variance-minimizing full-width half maximum (FWHM) of the pinhole equals the desired object spatial resolution divided by p2. Simulation results confirm this conclusion empirically. The general approach is a potentially useful addition to the collection of tools available for imaging system design.
RESUMO
Human papillomavirus (HPV) is associated with human neoplasms of squamous epithelium. Squamous papillomas and verrucous carcinomas are two types of squamous neoplasms of the larynx that present difficult problems in differential diagnosis. Using in situ hybridization with biotinylated DNA probes, we examined benign squamous papillomas and verrucous squamous carcinomas of the larynx for the presence of HPV. Forty-two biopsy specimens from 18 patients with laryngeal papillomas and 11 biopsy specimens from seven patients with verrucous carcinomas were obtained from the files of Pennsylvania Hospital, Philadelphia, PA. Tissue sections were hybridized with an HPV DNA cocktail. The HPV-positive cases then were subtyped further with DNA probes specific for HPV subtypes 6/11, 16/18, and 31/33/35. All benign squamous papillomas (42 of 42) were positive for HPV subtype 6/11. None of the verrucous carcinomas contained demonstrable HPV (none of 11). Some of the squamous papillomas were recurrences, which shows the persistence of the virus. These results indicate that laryngeal papillomas may be related to HPV, but verrucous carcinomas are not.
Assuntos
Carcinoma de Células Escamosas/ultraestrutura , Carcinoma de Células Escamosas/virologia , Hibridização In Situ , Neoplasias Laríngeas/ultraestrutura , Neoplasias Laríngeas/virologia , Papillomaviridae/isolamento & purificação , Carcinoma Verrucoso/ultraestrutura , Carcinoma Verrucoso/virologia , Humanos , Papiloma/ultraestrutura , Papiloma/virologiaRESUMO
Continuous veno-venous hemofiltration (CVVH) has been reported to provide beneficial effects during endotoxic shock. This experiment was designed to determine if selective removal of plasma mediators occurs during CVVH and if plasma concentrations of these mediators are reduced. A swine endotoxic-shock model with three groups was used (lipopolysaccharide (LPS) only (n = 6); LPS followed by CVVH (n = 6); and LPS followed by sham CVVH (n = 4). Plasma and filtrate samples were collected at frequent intervals for 5 h. Lactic acid (LA), eicosanoids [prostacyclin (6-keto PGF1 alpha), thromboxane (TxB2), and prostaglandin E2 (PGE2)] and tumor necrosis factor (TNF) were measured in plasma and filtrate. Plasma concentrations of 6-keto PGF1 alpha, TxB2, TNF, and LA were not significantly different in any group. LA, PGE2, 6-keto PGF1 alpha, and TXB2 concentrations were similar in filtrate and plasma. TNF did not move across the membrane into the filtrate, CVVH, as used in this experiment, did not significantly reduce plasma concentrations of any of these mediators.