Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Environ Monit Assess ; 193(2): 61, 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33443643

RESUMO

In view of increasing anthropogenic influences and global changes, quantification of carbon assimilation through photosynthesis has gained tremendous significance. Precise estimation of Gross Primary Productivity (GPP) is essential for several ecosystem models and is typically done using coarser scale satellite data. The mangrove ecosystem, which offers significant protection to the coastal environment, is one of the critical habitats from a global change point of view. Light use efficiency (LUE) was measured using diurnal in situ photosynthetic rate observations for 13 dominant mangrove species for 3 seasons at each of the three mangrove dominant test-sites situated along the east and west coast of India. Variations in photosynthetic rates among these species were studied for 3 seasons that indicated varying responses of mangrove ecosystem at each site. Among all species, Rhizophora mucronata and Sonneratia apetala indicated higher values at two of the test-sites. IRS Resourcesat-2 LISS-IV datasets were used for the estimation of GPP. Mean GPP for all the sites varied from 1.2 to 7.7 g C m-2 day-1 with maximum value of 14.4 g C m-2 day-1. Mean values of GPP varied across the sites, based on its maximum LUE values and available photosynthetically active radiation (PAR). The results provide GPP values at much better spatial resolution for a threatened habitat like mangroves that typically survive in a narrow habitat along the coasts.


Assuntos
Ecossistema , Áreas Alagadas , Monitoramento Ambiental , Índia , Fotossíntese , Estações do Ano
2.
Herz ; 40(3): 402-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25963172

RESUMO

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a rare cardiomyopathy associated with life-threatening arrhythmias and an increased risk of sudden cardiac death. In addition to mutations in desmosomal genes, environmental factors such as exercise and sport have been implicated in the pathogenesis of the disease. Recent studies have shown that exercise may be associated with adverse outcomes in patients with ARVD/C. On the basis of current evidence, patients with ARVD/C are recommended to limit exercise irrespective of their mutation status. Some studies have suggested the presence of an entirely acquired form of the disease caused by exercise, which has been dubbed "exercise-induced ARVD/C."


Assuntos
Displasia Arritmogênica Ventricular Direita/diagnóstico , Displasia Arritmogênica Ventricular Direita/genética , Morte Súbita Cardíaca/prevenção & controle , Desmossomos/genética , Programas de Rastreamento/métodos , Esportes , Predisposição Genética para Doença/genética , Alemanha , Humanos , Testes Obrigatórios/métodos , Mutação , Exame Físico/métodos
3.
Luminescence ; 29(6): 586-90, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24123997

RESUMO

A series of novel fluoroionophore bearing derivatives of benzo-15-crown-5 were synthesized by the amination of benzo-15-crown-5 followed by condensation with different quinones in the presence of titanium tetrachloride (TiCl4 ) and 1,4-diazabicyclo-[2.2.2]octane. The compounds were characterized by infrared, (1) H and (13) C nuclear magnetic resonance, mass spectroscopy and elemental analysis. Absorption and fluorescence spectral characteristics of these compounds were studied. It was observed that the anthraquinone derivative was acting as an Hg(2+) ion sensor.


Assuntos
Éteres de Coroa/química , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Iminas/química , Mercúrio/análise , Quinonas/química , Iminas/síntese química , Estrutura Molecular , Quinonas/síntese química
4.
Mol Biol Cell ; 34(3): br3, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36598814

RESUMO

Coordination between the microtubule and actin networks is essential for cell motility, neuronal growth cone guidance, and wound healing. Members of the CLASP (cytoplasmic linker-associated protein) family of proteins have been implicated in the cytoskeletal cross-talk between microtubules and actin networks; however, the molecular mechanisms underlying the role of CLASP in cytoskeletal coordination are unclear. Here, we investigate CLASP2α's cross-linking function with microtubules and F-actin. Our results demonstrate that CLASP2α cross-links F-actin to the microtubule lattice in vitro. We find that the cross-linking ability is retained by L-TOG2-S, a minimal construct containing the TOG2 domain and serine-arginine-rich region of CLASP2α. Furthermore, CLASP2α promotes the accumulation of multiple actin filaments along the microtubule, supporting up to 11 F-actin landing events on a single microtubule lattice region. CLASP2α also facilitates the dynamic organization of polymerizing actin filaments templated by the microtubule network, with F-actin forming bridges between individual microtubules. Finally, we find that depletion of CLASPs in vascular smooth muscle cells results in disorganized actin fibers and reduced coalignment of actin fibers with microtubules, suggesting that CLASP and microtubules contribute to higher-order actin structures. Taken together, our results indicate that CLASP2α can directly cross-link F-actin to microtubules and that this microtubule-CLASP-actin interaction may influence overall cytoskeletal organization in cells.


Assuntos
Citoesqueleto de Actina , Actinas , Microtúbulos , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/ultraestrutura , Actinas/metabolismo , Citoesqueleto/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Microtúbulos/ultraestrutura , Ligação Proteica , Humanos
5.
J Dairy Sci ; 95(1): 196-205, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22192198

RESUMO

The focus of the current research was to develop real-time PCR assays with improved sensitivity and the capacity to simultaneously speciate the 3 most common mycoplasma mastitis agents: Mycoplasma bovis, Mycoplasma californicum, and Mycoplasma bovigenitalium. Real-time PCR was chosen because it provides rapid results. Partial 16S rRNA gene sequencing was used as the gold standard for evaluating candidate real-time PCR assays. To ascertain the real-time PCR assay specificity, reference strains of Mycoplasma species, Acholeplasma axanthum, and common gram-positive and gram-negative mastitis pathogens were tested. No cross-reactions were observed. Mycoplasma spp. isolated from bovine milk samples (n=228) and other organ sites (n=40) were tested by the real-time PCR assays and the partial 16S rRNA gene sequencing assay. Overall accuracy of this novel real-time PCR was 98.51%; 4 of 228 isolates identified as M. bovis by the partial 16S rRNA gene sequencing assay were identified as both M. bovis and M. californicum by real-time PCR. Subsequent amplicon sequencing suggested the presence of both M. bovis and M. californicum in these 4 samples. Using a cycle threshold of 37, the detection limits for real-time PCR were 10 copies of DNA template for both M. bovis and M. bovigenitalium, and 1 copy for M. californicum. This real-time PCR assay is a diagnostic technique that may be used as a screening tool or as a confirmation test for mycoplasma mastitis.


Assuntos
Mastite Bovina/microbiologia , Infecções por Mycoplasma/veterinária , Mycoplasma bovigenitalium/genética , Mycoplasma bovis/genética , Mycoplasma/genética , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Animais , Bovinos , DNA Bacteriano/genética , Feminino , Mastite Bovina/diagnóstico , Leite/microbiologia , Infecções por Mycoplasma/diagnóstico , Infecções por Mycoplasma/microbiologia , RNA Ribossômico 16S/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos
6.
Biomed Phys Eng Express ; 7(6)2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34488197

RESUMO

In previous works, we showed that incorporating individual airways as organs-at-risk (OARs) in the treatment of lung stereotactic ablative radiotherapy (SAbR) patients potentially mitigates post-SAbR radiation injury. However, the performance of common clinical dose calculation algorithms in airways has not been thoroughly studied. Airways are of particular concern because their small size and the density differences they create have the potential to hinder dose calculation accuracy. To address this gap in knowledge, here we investigate dosimetric accuracy in airways of two commonly used dose calculation algorithms, the anisotropic analytical algorithm (AAA) and Acuros-XB (AXB), recreating clinical treatment plans on a cohort of four SAbR patients. A virtual bronchoscopy software was used to delineate 856 airways on a high-resolution breath-hold CT (BHCT) image acquired for each patient. The planning target volumes (PTVs) and standard thoracic OARs were contoured on an average CT (AVG) image over the breathing cycle. Conformal and intensity-modulated radiation therapy plans were recreated on the BHCT image and on the AVG image, for a total of four plan types per patient. Dose calculations were performed using AAA and AXB, and the differences in maximum and mean dose in each structure were calculated. The median differences in maximum dose among all airways were ≤0.3Gy in magnitude for all four plan types. With airways grouped by dose-to-structure or diameter, median dose differences were still ≤0.5Gy in magnitude, with no clear dependence on airway size. These results, along with our previous airway radiosensitivity works, suggest that dose differences between AAA and AXB correspond to an airway collapse variation ≤0.7% in magnitude. This variation in airway injury risk can be considered as not clinically relevant, and the use of either AAA or AXB is therefore appropriate when including patient airways as individual OARs so as to reduce risk of radiation-induced lung toxicity.


Assuntos
Broncoscopia , Radioterapia de Intensidade Modulada , Algoritmos , Humanos , Pulmão/diagnóstico por imagem , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada/efeitos adversos
7.
Phys Med Biol ; 66(4): 045035, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33207334

RESUMO

Many surrogate-based motion models (SMMs), proposed to guide motion management in radiotherapy, are constructed by correlating motion of an external surrogate and internal anatomy during CT-simulation. Changes in this correlation define model break down. We validate a methodology that incorporates fluoroscopic (FL) images acquired during treatment for SMM construction and update. Under a prospective IRB, 4DCT scans, VisionRT (VRT) surfaces, and orthogonal FLs were collected from five lung cancer patients. VRT surfaces and two FL time-series were acquired pre- and post-treatment. A simulated annealing optimization scheme was used to estimate optimal lung deformations by maximizing the mutual information (MI) between digitally reconstructed radiographs (DRRs) of the SMM-estimated 3D images and FLs. Our SMM used partial-least-regression and was trained using the optimal deformations and VRT surfaces from the first breathing-cycle. SMM performance was evaluated using the MI score between reference FLs and the corresponding SMM or phase-assigned 4DCT DRRs. The Hausdorff distance for contoured landmarks was used to evaluate target position estimation error. For four out of five patients, two principal components approximated lung surface deformations with submillimeter accuracy. Analysis of the MI score between more than 4000 pairs of FL and DRR demonstrated that our model led to more similarity between the FL and DRR images compared to 4DCT and DRR images from a model based on an a priori correlation model. Our SMM consistently displayed lower mean and 95th percentile Hausdorff distances. For one patient, 95th percentile Hausdorff distance was reduced by 11 mm. Patient-averaged reductions in mean and 95th percentile Hausdorff distances were 3.6 mm and 7 mm for right-lung, and 3.1 mm and 4 mm for left-lung targets. FL data were used to evaluate model performance and investigate the feasibility of model update. Despite variability in breathing, use of post-treatment FL preserved model fidelity and consistently outperformed 4DCT for position estimation.


Assuntos
Fluoroscopia , Tomografia Computadorizada Quadridimensional , Pulmão/diagnóstico por imagem , Pulmão/fisiologia , Modelos Biológicos , Movimento , Humanos , Respiração
8.
Xenobiotica ; 40(6): 400-14, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20334492

RESUMO

The metabolism and excretion of a GABA(A) partial agonist developed for the treatment of anxiety, CP-409,092; 4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxylic acid (4-methylaminomethyl-phenyl)-amide, were studied in rats following intravenous and oral administration of a single doses of [(14)C]CP-409,092. The pharmacokinetics of CP-409,092 following single intravenous and oral doses of 4 and 15 mg kg(-1), respectively, were characterized by high clearance of 169 + or - 18 ml min(-1) kg(-1), a volume of distribution of 8.99 + or - 1.46 l kg(-1), and an oral bioavailability of 2.9% + or - 3%. Following oral administration of 100 mg kg(-1) [(14)C]CP-409,092, the total recovery was 89.1% + or - 3.2% for male rats and 89.3% + or - 0.58% for female rats. Approximately 87% of the radioactivity recovered in urine and faeces were excreted in the first 48 h. A substantial portion of the radioactivity was measured in the faeces as unchanged drug, suggesting poor absorption and/or biliary excretion. There were no significant gender-related quantitative/qualitative differences in the excretion of metabolites in urine or faeces. The major metabolic pathways of CP-409,092 were hydroxylation(s) at the oxo-tetrahydro-indole moiety and oxidative deamination to form an aldehyde intermediate and subsequent oxidation to form the benzoic acid. The minor metabolic pathways included N-demethylation and subsequent N-acetylation and oxidation. The present work demonstrates that oxidative deamination at the benzylic amine of CP-409,092 and subsequent oxidation to form the acid metabolite seem to play an important role in the metabolism of the drug, and they contribute to its oral clearance and low exposure.


Assuntos
Anilidas/farmacocinética , Agonistas de Receptores de GABA-A , Indóis/farmacocinética , Administração Oral , Anilidas/administração & dosagem , Anilidas/metabolismo , Animais , Radioisótopos de Carbono/análise , Cromatografia Líquida , Avaliação Pré-Clínica de Medicamentos , Fezes/química , Feminino , Indóis/administração & dosagem , Indóis/metabolismo , Injeções Intravenosas , Masculino , Estrutura Molecular , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em Tandem
9.
PDA J Pharm Sci Technol ; 74(4): 468-494, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32467176

RESUMO

This article reviews currently available scientific literature related to the epidemiology, infectivity, survival, and susceptibility to disinfectants of Coronaviruses, in the context of the controls established to meet good manufacturing practice (GMP) regulations and guidance, and the public health guidance issued specifically to combat the COVID-19 pandemic. The possible impact of the COVID-19 pandemic on the pharmaceutical supply chain is assessed and recommendations are listed for risk mitigation steps to minimize supply disruption to pharmaceutical drug products. Areas addressed include a brief history of the COVID-19 viral pandemic, a description of the virus, the regulatory response to the pandemic, the screening of employees, the persistence of the virus on inanimate surfaces, cleaning and disinfection of manufacturing facilities, the use of GMP-mandated personal protective equipment to counter the spread of the disease, the role of air changes in viral clearance, and approaches to risk assessment and mitigation. Biological medicinal products have a great record of safety, yet the cell cultures used for production can be susceptible to viruses, and contamination events have occurred. Studies on SARS-CoV-2 for it ability to replicate in various mammalian cell lines used for biopharmaceutical manufacturing suggests that the virus poses a low risk and any contamination would be detected by currently used adventitious virus testing. The consequences of the potential virus exposure of manufacturing processes as well as the effectiveness of mitigation efforts are discussed. The pharmaceutical supply chain is complex, traversing many geographies and companies that range from large multinationals to mid- and small-size operations. This paper recommends practices that can be adopted by all companies, irrespective of their size, geographic location, or position in the supply chain.


Assuntos
Infecções por Coronavirus/prevenção & controle , Desinfecção/métodos , Pandemias/prevenção & controle , Preparações Farmacêuticas/provisão & distribuição , Pneumonia Viral/prevenção & controle , Animais , Betacoronavirus/isolamento & purificação , COVID-19 , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Desinfetantes/química , Contaminação de Medicamentos/prevenção & controle , Indústria Farmacêutica/normas , Contaminação de Equipamentos/prevenção & controle , Humanos , Preparações Farmacêuticas/normas , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Gestão de Riscos/métodos , SARS-CoV-2 , Replicação Viral
10.
Phys Med Biol ; 65(16): 165010, 2020 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-32575096

RESUMO

Recent changes to the guidelines for screening and early diagnosis of lung cancer have increased the interest in preserving post-radiotherapy lung function. Current investigational approaches are based on spatially mapping functional regions and generating regional avoidance plans that preferentially spare highly ventilated/perfused lung. A potentially critical, yet overlooked, aspect of functional avoidance is radiation injury to peripheral airways, which serve as gas conduits to and from functional lung regions. Dose redistribution based solely on regional function may cause irreparable damage to the 'supply chain'. To address this deficiency, we propose the functionally weighted airway sparing (FWAS) method. FWAS (i) maps the bronchial pathways to each functional sub-lobar lung volume; (ii) assigns a weighting factor to each airway based on the relative contribution of the sub-volume to overall lung function; and (iii) creates a treatment plan that aims to preserve these functional pathways. To evaluate it, we used four cases from a retrospective cohort of SAbR patients treated for lung cancer. Each patient's airways were auto-segmented from a diagnostic-quality breath-hold CT using a research virtual bronchoscopy software. A ventilation map was generated from the planning 4DCT to map regional lung function. For each terminal airway, as resolved by the segmentation software, the total ventilation within the sub-lobar volume supported by that airway was estimated and used as a function-based weighting factor. Upstream airways were weighted based on the cumulative volumetric ventilation supported by corresponding downstream airways. Using a previously developed model for airway radiosensitivity, dose constraints were determined for each airway corresponding to a <5% probability of airway collapse. Airway dose constraints, ventilation scores, and clinical dose constraints were input to a swarm optimization-based inverse planning engine to create a 3D conformal SAbR plan (CRT). The FWAS plans were compared to the patients' prescribed CRT clinical plans and the inverse-optimized clinical plans. Depending on the size and location of the tumour, the FWAS plan showed superior preservation of ventilation due to airflow preservation through open pathways (i.e. cumulative ventilation score from the sub-lobar volumes of open pathways). Improvements ranged between 3% and 23%, when comparing to the prescribed clinical plans, and between 3% and 35%, when comparing to the inverse-optimized clinical plans. The three plans satisfied clinical requirements for PTV coverage and OAR dose constraints. These initial results suggest that by sparing pathways to high-functioning lung subregions it is possible to reduce post-SAbR loss of respiratory function.


Assuntos
Neoplasias Pulmonares/radioterapia , Pulmão/fisiopatologia , Tratamentos com Preservação do Órgão/métodos , Órgãos em Risco/efeitos da radiação , Ventilação Pulmonar/fisiologia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Idoso , Algoritmos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Respiração , Estudos Retrospectivos
11.
Vet Microbiol ; 134(1-2): 73-81, 2009 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-18950969

RESUMO

Coagulase-negative Staphylococcus (CNS) isolates (n=168) obtained from milk from heifers and dairy cows were screened for minimum inhibitory concentration (MIC) to antimicrobials used commonly for mastitis therapy. Of the 10 CNS species included in the study, the predominant species were Staphylococcus chromogenes (n=61), Staphylococcus epidermidis (n=37), Staphylococcus hyicus (n=37), and Staphylococcus simulans (n=16). The majority of CNS was susceptible to ampicillin, oxacillin, cephalothin, and ceftiofur. Erythromycin and pirlimycin were also very effective in vitro inhibitors of CNS. The only exception was observed with S. epidermidis. Of 37 S. epidermidis evaluated, 13 (35%) exhibited efflux-based resistance to erythromycin (> or =16 microg/ml) encoded by msrA and one isolate carried ermC encoding ribosomal methylase-based resistance to both erythromycin (> or =64 microg/ml) and pirlimycin (> or =64 microg/ml). A total of 17 S. epidermidis, 11 S. chromogenes, and one S. hyicus exhibited phenotypic resistance to ampicillin (> or =0.5 microg/ml). Constitutive beta-lactamase production was observed in all ampicillin resistant isolates except 4 S. epidermidis that exhibited inducible beta-lactamase production. Induced beta-lactamase production was also observed in 13 S. epidermidis that were phenotypically susceptible to the entire MIC panel. All isolates that produced beta-lactamase either constitutively or by induction carried blaZ. S. epidermidis (n=12, 32%) that were resistant to methicillin (oxacillin > or =0.5 microg/ml) carried low affinity penicillin-binding protein encoded by mecA. Most multi-drug resistant (MDR) S. epidermidis (> or =2 resistance genes) were resistant to ampicillin, erythromycin and methicillin. All except one MDR S. epidermidis had icaAB, which encodes for polysaccharide intercellular adhesion. Based on pulsed field gel electrophoresis, MDR S. epidermidis were closely related genotypically, and were isolated from different cows on the same farm suggesting clonal dissemination. Bovine S. epidermidis share antimicrobial resistance patterns and virulence determinants of strains observed in human infections. Studying CNS at the species level can provide valuable information about species-specific differences that can be vital data for effective mastitis therapy and management.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Mastite Bovina/microbiologia , Leite/microbiologia , Staphylococcus/efeitos dos fármacos , Staphylococcus/enzimologia , Animais , Bovinos , Variação Genética , Genótipo , Testes de Sensibilidade Microbiana , Filogenia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/classificação , Staphylococcus/isolamento & purificação
12.
Med Phys ; 46(12): 5407-5420, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31518437

RESUMO

PURPOSE: We develop and validate a motion model that uses real-time surface photogrammetry acquired concurrently with four-dimensional computed tomography (4DCT) to estimate respiration-induced changes within the entire irradiated volume, over arbitrarily many respiratory cycles. METHODS: A research, couch-mounted, VisionRT (VRT) system was used to acquire optical surface data (15 Hz, ROI = 15 × 20 cm2 ) from the thoraco-abdominal surface of a consented lung SBRT patient, concurrently with their standard-of-care 4DCT. The end-exhalation phase from the 4DCT was regarded as reference and for each remaining phase, deformation vector fields (DVFs) with respect to the reference phase were computed. To reduce dimensionality, the first two principal components (PCs) of the matrix of nine DVFs were calculated. In parallel, ten phase-averaged VRT surfaces were created. Surface DVFs and corresponding PCs were computed. A principal least squares regression was used to relate the PCs of surface DVF to those of volume DVFs, establishing a relationship between time-varying surface and the underlying time-varying volume. Proof-of-concept validation was performed during each treatment fraction by concurrently acquiring 30 s time series of real-time surface data and "ground truth" kV fluoroscopic data (FL). A ray-tracing algorithm was used to create a digitally reconstructed fluorograph (DRF), and motion trajectories of high-contrast, soft-tissue, anatomical features in the DRF were compared with those from kV FL. RESULTS: For five of the six fluoroscopic acquisition sessions, the model out-performed 4DCT in predicting contour Dice coefficient with respect to fluoroscopy-derived contours. Similarly, the model exhibited a marked improvement over 4DCT for patch positions on the diaphragm. Model patch position errors varied from 5 to -15 mm while 4DCT errors ranged between 5 and -22.4 mm. For one fluoroscopic acquisition, a marked change in the a priori internal-external correlation resulted in model errors comparable to those of 4DCT. CONCLUSIONS: We described the development and a proof-of-concept validation for a volumetric motion model that uses surface photogrammetry to correlate the time-varying thoraco-abdominal surface to the time-varying internal thoraco-abdominal volume. These early results indicate that the proposed approach can result in a marked improvement over 4DCT. While limited by the duration of the fluoroscopic acquisitions as well as the resolution of the acquired images, the DRF-based proof-of-concept technique developed here is model-agnostic, and therefore, has the potential to be used as an in-patient validation tool for other volumetric motion models.


Assuntos
Tomografia Computadorizada Quadridimensional , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/radioterapia , Modelos Biológicos , Movimento , Fotogrametria , Idoso , Fracionamento da Dose de Radiação , Humanos , Neoplasias Pulmonares/fisiopatologia , Masculino , Respiração , Fatores de Tempo
13.
J Assoc Physicians India ; 56: 99-102, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18472509

RESUMO

BACKGROUND: Cardiovascular diseases (CVD) are the major cause of morbidity and mortality in our society with dyslipidemia contributing significantly to atherosclerosis. Thus measurement of plasma lipids would help in identifying people at risk for CVD. The goal of this study was to ascertain the prevalence of Dyslipidemia among young adult population in urban India. MATERIAL AND METHODS: The study was conducted for a period of one year--from 1st January 2006 to 31st December 2006. Around 1805 subjects with > or =40 age group were selected from a population of approximately 9000 urban dwellers who had attended annual general health check ups in P. D. Hinduja National Hospital and Medical research Center. Health status was evaluated by physical check ups, complete fasting lipid profiles and blood glucose levels. Dyslipidemia risk and impaired blood sugar levels were determined as per National Cholesterol Education Program (NCEP) - Adult Treatment Panel (ATP) III guidelines and American Diabetes Association (ADA) respectively. RESULTS: The prevalence of dyslipidemia was observed to be higher in males then in females. Among participants who had a total Cholesterol (TC) concentration > or = 200 mg/dl, 38.7% were males and 23.3% were females. High density lipoprotein cholesterol (HDL-C) was abnormally low in 64.2% males and 33.8% in females. The increase of prevalence of hypercholesterolemia and hypertriglyceridemia was more prominent in 31-40 age group than in < or =30 age group. CONCLUSION: The low percentage of adults with controlled lipid concentrations suggests that there is a need for awareness programs for the prevention and control of Dyslipidemia and impaired blood sugar levels.


Assuntos
Dislipidemias/epidemiologia , Adulto , Feminino , Humanos , Índia/epidemiologia , Masculino , Prevalência , Estudos Retrospectivos , Distribuição por Sexo
14.
Sens Actuators A Phys ; 140(2): 185-193, 2007 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-18159218

RESUMO

Megavoltage x-ray imaging performed during radiotherapy is the method of choice for geometric verification of patient localization and dose delivery. Presently, such imaging is increasingly performed using electronic portal imaging devices (EPIDs) based on indirect detection active matrix flat panel imagers (AMFPIs). These devices use a scintillating phosphor screen in order to convert incident x-rays into optical photons, which are then detected by the underlying active matrix photodiode array. The use of a continuous phosphor introduces a trade-off between x-ray quantum efficiency and spatial resolution, which limits current devices to use only ∼2% of the incident x-rays. This trade-off can be circumvented by "segmented phosphor screens", comprising a two-dimensional matrix of optically-isolated cell structures filled with scintillating phosphor. In this work we describe the fabrication of millimeter-thick segmented phosphor screens using the MEMS (micro-electro-mechanical-system) polymer SU-8. This method is capable of being extended to large-area substrates.

15.
Phys Med Biol ; 62(5): 1791-1809, 2017 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-28075331

RESUMO

Baseline shifts in respiratory patterns can result in significant spatiotemporal changes in patient anatomy (compared to that captured during simulation), in turn, causing geometric and dosimetric errors in the administration of thoracic and abdominal radiotherapy. We propose predictive modeling of the tumor motion trajectories for predicting a baseline shift ahead of its occurrence. The key idea is to use the features of the tumor motion trajectory over a 1 min window, and predict the occurrence of a baseline shift in the 5 s that immediately follow (lookahead window). In this study, we explored a preliminary trend-based analysis with multi-class annotations as well as a more focused binary classification analysis. In both analyses, a number of different inter-fraction and intra-fraction training strategies were studied, both offline as well as online, along with data sufficiency and skew compensation for class imbalances. The performance of different training strategies were compared across multiple machine learning classification algorithms, including nearest neighbor, Naïve Bayes, linear discriminant and ensemble Adaboost. The prediction performance is evaluated using metrics such as accuracy, precision, recall and the area under the curve (AUC) for repeater operating characteristics curve. The key results of the trend-based analysis indicate that (i) intra-fraction training strategies achieve highest prediction accuracies (90.5-91.4%); (ii) the predictive modeling yields lowest accuracies (50-60%) when the training data does not include any information from the test patient; (iii) the prediction latencies are as low as a few hundred milliseconds, and thus conducive for real-time prediction. The binary classification performance is promising, indicated by high AUCs (0.96-0.98). It also confirms the utility of prior data from previous patients, and also the necessity of training the classifier on some initial data from the new patient for reasonable prediction performance. The ability to predict a baseline shift with a sufficient look-ahead window will enable clinical systems or even human users to hold the treatment beam in such situations, thereby reducing the probability of serious geometric and dosimetric errors.


Assuntos
Movimento (Física) , Neoplasias/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Respiração , Algoritmos , Humanos
16.
J Dairy Sci ; 89(7): 2451-8, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16772561

RESUMO

A 2-part study was conducted to determine the risk of exposure to human pathogens from raw milk. The first part of the study focused on determining raw milk consumption habits of dairy producers. A total of 248 dairy producers from 16 counties in Pennsylvania were surveyed. Overall, 105 (42.3%) of the 248 dairy producers consumed raw milk and 170 (68.5%) of the 248 dairy producers were aware of foodborne pathogens in raw milk. Dairy producers who were not aware of foodborne pathogens in raw milk were 2-fold more likely to consume raw milk compared with dairy producers who were aware of foodborne pathogens. The majority of dairy producers who consumed raw milk indicated that taste (72%) and convenience (60%) were the primary factors for consuming raw milk. Dairy producers who resided on the dairy farm were nearly 3-fold more likely to consume raw milk compared with those who lived elsewhere. In the second part of the study, bulk tank milk from the 248 participating dairy herds was examined for foodborne pathogens. Campylobacter jejuni (2%), Shiga toxin-producing Escherichia coli (2.4%), Listeria monocytogenes (2.8%), Salmonella (6%), and Yersinia enterocolitica (1.2%) were detected in the milk samples. Salmonella isolates were identified as S. enterica serotype Typhimurium (n = 10) and S. enterica serotype Newport (n = 5). Of the 248 bulk tank milk samples, 32 (13%) contained > or = 1 species of bacterial pathogens. The findings of the study could assist in developing farm community-based educational programs on the risks of consuming raw milk.


Assuntos
Bactérias/isolamento & purificação , Leite/microbiologia , Animais , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/transmissão , Campylobacter jejuni/isolamento & purificação , Indústria de Laticínios/instrumentação , Escherichia coli/isolamento & purificação , Manipulação de Alimentos/legislação & jurisprudência , Manipulação de Alimentos/métodos , Humanos , Listeria monocytogenes/isolamento & purificação , Pennsylvania , Salmonella/isolamento & purificação , Salmonella enterica/classificação , Salmonella enterica/isolamento & purificação , Sorotipagem , Yersinia enterocolitica/isolamento & purificação
17.
Phys Med Biol ; 61(16): 6181-202, 2016 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-27476472

RESUMO

A critical aspect of highly potent regimens such as lung stereotactic body radiation therapy (SBRT) is to avoid collateral toxicity while achieving planning target volume (PTV) coverage. In this work, we describe four dimensional conformal radiotherapy using a highly parallelizable swarm intelligence-based stochastic optimization technique. Conventional lung CRT-SBRT uses a 4DCT to create an internal target volume and then, using forward-planning, generates a 3D conformal plan. In contrast, we investigate an inverse-planning strategy that uses 4DCT data to create a 4D conformal plan, which is optimized across the three spatial dimensions (3D) as well as time, as represented by the respiratory phase. The key idea is to use respiratory motion as an additional degree of freedom. We iteratively adjust fluence weights for all beam apertures across all respiratory phases considering OAR sparing, PTV coverage and delivery efficiency. To demonstrate proof-of-concept, five non-small-cell lung cancer SBRT patients were retrospectively studied. The 4D optimized plans achieved PTV coverage comparable to the corresponding clinically delivered plans while showing significantly superior OAR sparing ranging from 26% to 83% for D max heart, 10%-41% for D max esophagus, 31%-68% for D max spinal cord and 7%-32% for V 13 lung.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Tomografia Computadorizada Quadridimensional/métodos , Neoplasias Pulmonares/diagnóstico por imagem , Modelos Teóricos , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Humanos , Neoplasias Pulmonares/cirurgia , Dosagem Radioterapêutica , Estudos Retrospectivos
18.
J Dairy Sci ; 88(8): 2991-9, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16027213

RESUMO

A survey was conducted (July 2001 to June 2002) on antibiotic usage of 113 dairy herds from 13 counties in Pennsylvania. Fifty percent of dairy farms surveyed maintained antibiotic treatment records. Only 21% of dairy producers had written plans for treating sick animals. Thirty-two percent of dairy producers sought veterinarian advice before administering antibiotics and on most farms (93%), antibiotics were administered by the owner/manager or designated herdsman. Twenty-four percent of the dairy producers said they always completed the course of antibiotic treatment. Any extra-label use of antibiotics was administered only on the guidelines of a veterinarian on majority of the farms. Comprehensive records from 33 dairy farms indicated that antibiotic usage was largest for calves with enteritis (36%) followed by pneumonia in calves (25%) and foot rot in cattle (16%). Twenty-four antibiotics including beta-lactams, spectinomycin, florfenicol, and tetracyclines were used on these farms. Beta-lactam antibiotics were used mostly for dry cow therapy, clinical mastitis, and on some farms for pneumonia and metritis. On 18% of the dairy herds surveyed, ceftiofur was used in an extra-label manner to treat mastitis in lactating cattle. On 70% of farms, calves were fed medicated milk replacers containing oxytetracycline and neomycin. The results of this study suggest that antibiotics are used extensively on dairy herds for both therapeutic and prophylactic purposes. Beta-lactams and tetracyclines were the most widely used antibiotics. There is considerable variation in the management practices associated with antibiotic use on dairy farms. It is anticipated that the findings of this survey will permit developing new strategies for prudent use of antibiotics on dairy herds.


Assuntos
Antibacterianos/administração & dosagem , Doenças dos Bovinos/tratamento farmacológico , Indústria de Laticínios/métodos , Animais , Antibacterianos/análise , Antibacterianos/uso terapêutico , Bovinos , Doenças dos Bovinos/prevenção & controle , Cefalosporinas/administração & dosagem , Cefalosporinas/uso terapêutico , Resíduos de Drogas/análise , Farmacorresistência Bacteriana , Endometrite/tratamento farmacológico , Enterite/tratamento farmacológico , Enterite/veterinária , Feminino , Doenças do Pé/tratamento farmacológico , Doenças do Pé/veterinária , Mastite Bovina/tratamento farmacológico , Leite/química , Pennsylvania , Pneumonia/tratamento farmacológico , Pneumonia/veterinária , Inquéritos e Questionários , Tetraciclinas/administração & dosagem , Tetraciclinas/uso terapêutico , beta-Lactamas/administração & dosagem , beta-Lactamas/uso terapêutico
19.
Invest Ophthalmol Vis Sci ; 31(11): 2342-4, 1990 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2122963

RESUMO

The authors investigated the ability of vitreous harvested from eyes previously infected with Staphylococcus epidermidis or inflamed with heat-killed cells of the same organism to support subsequent in vitro bacterial growth. Growth of S. epidermidis and S. aureus was not supported by previously inflamed or previously infected vitreous, but Pseudomonas aerugnosa grew in all samples. These findings suggest induction of an antistaphylococcal substance by infection or inflammation of rabbit vitreous by S. epidermidis.


Assuntos
Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus epidermidis/crescimento & desenvolvimento , Corpo Vítreo/microbiologia , Animais , Afacia/microbiologia , Contagem de Colônia Microbiana , Oftalmopatias/microbiologia , Técnicas In Vitro , Inflamação/microbiologia , Pseudomonas aeruginosa/isolamento & purificação , Coelhos , Staphylococcus aureus/isolamento & purificação , Staphylococcus epidermidis/isolamento & purificação
20.
Arch Ophthalmol ; 109(8): 1155-7, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1867561

RESUMO

Biofilms of Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus epidermidis, Streptococcus pyogenes, and Candida albicans, established in the wells of a polyethylene contact lens case, retained viability to certain soft contact lens disinfectant solutions after exposure for the manufacturer's minimum recommended disinfection times. The relative order of resistance of bacterial biofilms was as follows: S marcescens was greater than P aeruginosa, which was greater than S epidermidis, which was greater than S pyogenes. Air drying of biofilms for 10 hours increased the efficacy of the disinfectant solutions, but drying was not enough to decrease the incidence of recovery to 0% for all solutions. Hydrogen peroxide was more effective against biofilms than disinfectant solutions formulated with chlorhexidine gluconate or polyquaternium-1 or polyaminopropyl biguanide. We recommend that determination of efficacy of contact lens disinfectant solutions should include challenges against biofilms.


Assuntos
Lentes de Contato Hidrofílicas , Desinfetantes/normas , Contaminação de Equipamentos , Bactérias/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Desinfetantes/farmacologia , Resistência Microbiana a Medicamentos , Humanos , Peróxido de Hidrogênio/farmacologia , Soluções
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA