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1.
Health Phys ; 119(2): 236-246, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32576739

RESUMO

This COMAR Technical Information Statement (TIS) addresses health and safety issues concerning exposure of the general public to radiofrequency (RF) fields from 5G wireless communications networks, the expansion of which started on a large scale in 2018 to 2019. 5G technology can transmit much greater amounts of data at much higher speeds for a vastly expanded array of applications compared with preceding 2-4G systems; this is due, in part, to using the greater bandwidth available at much higher frequencies than those used by most existing networks. Although the 5G engineering standard may be deployed for operating networks currently using frequencies extending from 100s to 1,000s of MHz, it can also operate in the 10s of GHz where the wavelengths are 10 mm or less, the so-called millimeter wave (MMW) band. Until now, such fields were found in a limited number of applications (e.g., airport scanners, automotive collision avoidance systems, perimeter surveillance radar), but the rapid expansion of 5G will produce a more ubiquitous presence of MMW in the environment. While some 5G signals will originate from small antennas placed on existing base stations, most will be deployed with some key differences relative to typical transmissions from 2-4G base stations. Because MMW do not penetrate foliage and building materials as well as signals at lower frequencies, the networks will require "densification," the installation of many lower power transmitters (often called "small cells" located mainly on buildings and utility poles) to provide for effective indoor coverage. Also, "beamforming" antennas on some 5G systems will transmit one or more signals directed to individual users as they move about, thus limiting exposures to non-users. In this paper, COMAR notes the following perspectives to address concerns expressed about possible health effects of RF field exposure from 5G technology. First, unlike lower frequency fields, MMW do not penetrate beyond the outer skin layers and thus do not expose inner tissues to MMW. Second, current research indicates that overall levels of exposure to RF are unlikely to be significantly altered by 5G, and exposure will continue to originate mostly from the "uplink" signals from one's own device (as they do now). Third, exposure levels in publicly accessible spaces will remain well below exposure limits established by international guideline and standard setting organizations, including ICNIRP and IEEE. Finally, so long as exposures remain below established guidelines, the research results to date do not support a determination that adverse health effects are associated with RF exposures, including those from 5G systems. While it is acknowledged that the scientific literature on MMW biological effect research is more limited than that for lower frequencies, we also note that it is of mixed quality and stress that future research should use appropriate precautions to enhance validity. The authorship of this paper includes a physician/biologist, epidemiologist, engineers, and physical scientists working voluntarily and collaboratively on a consensus basis.


Assuntos
Radiação Eletromagnética , Exposição Ambiental , Comunicação , Campos Eletromagnéticos , Humanos , Micro-Ondas/efeitos adversos , Saúde Pública , Exposição à Radiação , Ondas de Rádio , Pele , Sociedades Científicas , Tecnologia , Tecnologia sem Fio
2.
Aesthetic Plast Surg ; 41(4): 845-855, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28451799

RESUMO

BACKGROUND: Frontal fullness in Asians is often considered to indicate one's public popularity and leadership skills. Numerous materials and techniques have been applied clinically to recontour or volumize the frontal area, with variable results. The micro-autologous fat transplantation (MAFT) technique proposed by Lin et al. (2nd academic congress of Taiwan Cosmetic Association Taipei, Taiwan) in 2007 has demonstrated its feasibility in facial rejuvenation. In the present study, we used an innovative instrument to apply the MAFT technique to frontal augmentation with fat grafting and reported the results. METHODS: MAFT was performed on 178 patients (167 female, 11 male) during a 5-year period starting in January 2010. Fat was harvested by liposuction, processed and refined by centrifugation at 1200×g for 3 min. The purified fat was micro-transplanted for frontal contouring with the assistance of an instrument, the MAFT-GUN. The patients were followed up regularly, and photographs were taken for comparison. RESULTS: On average, the MAFT procedure took 52 min to complete. The average amount of delivered fat was 10.2 mL. The follow-up period was 34 months on average. No complications, including neurovascular injury, skin necrosis, abscess, nodulation, calcification or irregularity, were noted. A patient-rated satisfaction 5-point Likert scale demonstrated that 83.1% of all patients had favorable results (48.3% were satisfied, and 34.8% were very satisfied). CONCLUSION: The concept and technique of MAFT has changed fat grafting from an operation with unpredictable clinical results to an easy, reliable and consistent procedure. Furthermore, the use of a precisely controlled instrument enabled surgeons to perform highly accurate micro-fat grafting. In comparison with other strategies for volume restoration, the MAFT procedure demonstrated high patient satisfaction with the long-term results. Therefore, the use of MAFT as an alternative approach to forehead contouring and volumizing was addressed. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .


Assuntos
Tecido Adiposo/transplante , Rejuvenescimento , Envelhecimento da Pele/fisiologia , Cirurgia Plástica/métodos , Adulto , Idoso , Envelhecimento , Estética , Feminino , Seguimentos , Testa/cirurgia , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Ritidoplastia , Medição de Risco , Estudos de Amostragem , Taiwan , Transplante Autólogo
3.
Aliment Pharmacol Ther ; 44(5): 427-37, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27363687

RESUMO

BACKGROUND: Levofloxacin triple therapy has been used for the first-line and second-line treatment of Helicobacter pylori infection for more than 10 years. AIMS: To systematically review the efficacy of levofloxacin triple therapy in the first- and second-line treatment, and to assess the time trend and factors that might affect its efficacy. METHODS: Prospective trials reporting the efficacy of levofloxacin triple therapy in either the first-line or second-line treatment of H. pylori infection in adults were searched from the PubMed and Cochrane database from January 2000 to September 2015. Meta-analysis was performed to calculate the cumulative eradication rate and the efficacies in subgroups. RESULTS: Of the 322 articles identified, a total of 4574 patients from 41 trials, including 16 trials in the first-line treatment and 25 trials in the second-line treatment were eligible for analysis. The cumulative eradication rate was 77.3% (95% confidence intervals, CI: 74.7-79.6) and was 80.7% (95% CI 77.1-83.7) in the first-line treatment and 74.5% (95% CI: 70.9-77.8) in the second-line treatment. The efficacies of levofloxacin triple therapy before 2008, between 2009 and 2011, and after 2012 were 77.4%, 79.6% and 74.8% respectively. The eradication rate was higher when levofloxacin was given once daily (80.6%, 95% CI: 77.1-83.7) than twice daily (73.6%, 95% CI: 69.7-77.2). The efficacy was significantly higher in levofloxacin-susceptible strains than resistant strains (81.1% vs. 36.3%, risk ratio 2.18, 95% CI: 1.6-3, P < 0.001). CONCLUSION: The efficacy of levofloxacin triple therapy has been lower than 80% in many countries and it is not recommended when the levofloxacin resistance is higher than 5-10%.


Assuntos
Antibacterianos/administração & dosagem , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/efeitos dos fármacos , Levofloxacino/administração & dosagem , Adulto , Amoxicilina/administração & dosagem , Ensaios Clínicos como Assunto/métodos , Bases de Dados Factuais , Farmacorresistência Bacteriana , Quimioterapia Combinada , Helicobacter pylori/fisiologia , Humanos , Estudos Prospectivos , Resultado do Tratamento
4.
Electromagn Biol Med ; 34(3): 175-9, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26444189

RESUMO

Although there is scientific consensus that radiofrequency (RF) exposure at high intensity can cause thermal effects, including well-established adverse health effects, there is still considerable controversy on whether low-intensity RF exposure can cause biological effects, especially adverse health effects. The objective of this paper is to describe several reported "non-thermal" effects that were later shown to be due to a weak thermal effect or an experimental artifact by properly conducted and thorough follow-on scientific research. First, the multiple factors that can cause different RF energy absorption in biological tissues are reviewed and second, several examples of experimental artifacts in published papers are described to demonstrate the importance of paying attention to dosimetry and temperature control. For example, isolated nerve response studies show that when temperature of the RF-exposed tissues is controlled, effects disappeared. During RF exposure, conductive electrodes routinely used in physiological studies have been shown to cause field intensification at the tips or contacts of the electrodes with biological tissue; thus, the RF exposure at the site of measurement could be much higher than the incident field. In some in vitro studies, a lack of temperature uniformity in RF-exposed cell cultures and rate of heating explain changes originally reported to be due to low-level RF exposure. In other studies, detailed dosimetry studies have identified artifacts that explain the reasons why so-called "non-thermal" effects were mistakenly reported. Researchers should look for explanations for their own findings, and not expect others to figure out what was the reason for their observed effects.


Assuntos
Exposição à Radiação/efeitos adversos , Ondas de Rádio/efeitos adversos , Radiobiologia/métodos , Animais , Comportamento Animal/efeitos da radiação , Condutividade Elétrica , Eletrodos , Humanos , Sistema Nervoso/efeitos da radiação , Ratos , Temperatura
6.
Oncogene ; 29(41): 5619-29, 2010 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-20676141

RESUMO

Histone deacetylase inhibitors (HDACi) are potent anti-cancer agents for variety of cancer types. Suberoylanilide hydroxamic acid (SAHA) has been approved as a drug to treat cutaneous T cell lymphoma, and the combination of HDACi and other agents have been actively tested in many clinical trials. Adenovirus 5 early region 1A (E1A) has been shown to exhibit high tumor suppressor activity, and gene therapy using E1A has been tested in clinical trials. Here, we showed that proapoptotic activity of HDACi was robustly enhanced by E1A in multiple cancer cells, but not in normal cells. Moreover, we showed that combination of E1A gene therapy and SAHA showed high therapeutic efficacy with low toxicity in vivo ovarian and breast xenograft models. SAHA downregulated Bcl-XL and upregulated proapoptotic BH3-only protein Bim, whose expression was further enhanced by E1A in cancer cells. These alterations of Bcl-2 family proteins were critical for apoptosis induced by the combination in cancer cells. SAHA enhanced acetylation of histone H3 in Bim promoter region, while E1A upregulated Egr-1, which was directly involved in Bim transactivation. Together, our results provide not only a novel insight into the mechanisms underlying anti-tumor activity of E1A, but also a rationale for the combined HDACi and E1A gene therapy in future clinical trials.


Assuntos
Proteínas E1 de Adenovirus/fisiologia , Proteínas Reguladoras de Apoptose/metabolismo , Apoptose/efeitos dos fármacos , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Proteínas de Membrana/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Acetilação/efeitos dos fármacos , Proteínas E1 de Adenovirus/genética , Animais , Proteínas Reguladoras de Apoptose/genética , Proteína 11 Semelhante a Bcl-2 , Western Blotting , Linhagem Celular , Linhagem Celular Tumoral , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Imunoprecipitação da Cromatina , Proteína 1 de Resposta de Crescimento Precoce/genética , Feminino , Terapia Genética , Histonas/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Proteínas de Membrana/genética , Camundongos , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapia , Proteínas Proto-Oncogênicas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regulação para Cima/efeitos dos fármacos , Vorinostat , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Reprod Domest Anim ; 45(5): 900-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19392667

RESUMO

The aim of this study was to generate a transgenic mouse that ubiquitously expressed enhanced green fluorescent protein (EGFP) under the control of the murine phosphoglycerate kinase 1 promoter by allotransplantation of transgenic mouse ovaries. The EGFP transgenic mice expressed green fluorescence in many organs, and the fluorescence was detected as early as the embryonic stage. Ovaries from the EGFP transgenic mice were allotransplanted into recipients and these mice were mated with normal male mice. Histological sections of EGFP-allotransplanted ovaries from the recipient mice showed the well development and formation at follicles and corpora lutea. The green fluorescence was clearly detectable at the allotransplanted section of the ovaries, which had fused with the normal ovary. The average size of the first litter from these mice was 6.8 ± 1.2 pups per recipient, and 17.8% of the pups expressed EGFP. These results demonstrated that allotransplantation of transgenic ovaries can restore a normal reproductive lifespan and can be used to generate a ubiquitously expressing EGFP animal model.


Assuntos
Proteínas de Fluorescência Verde/metabolismo , Ovário/metabolismo , Fosfoglicerato Quinase/metabolismo , Regiões Promotoras Genéticas/genética , Animais , Feminino , Regulação da Expressão Gênica/fisiologia , Proteínas de Fluorescência Verde/genética , Masculino , Camundongos , Camundongos Transgênicos , Ovário/transplante , Fosfoglicerato Quinase/genética , Gravidez
8.
Nanotechnology ; 19(44): 445714, 2008 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-19081800

RESUMO

In this study, we fabricated electrospun silica nanofiber membranes and investigated their use in biomolecular sensing. The diameter, porosity and surface-to-volume ratio of nanofiber membranes were investigated under different fabrication conditions. Using this type of nanofiber membrane, enzyme-linked immunosorbent assay (ELISA) was performed, and the results were compared with those obtained with conventional ELISA using polystyrene well plates. The minimum detectable concentration was determined as 0.19 ng ml(-1) (1.6 pM), which is 32 times lower than that of conventional ELISA. In addition, the detection time for all processes for the nanofiber membrane was reduced to 1 h, compared with 1 day for conventional ELISA. The increased sensitivity, faster reaction time, and affordability of the nanofiber membrane make it well suited for bio-chip use.

9.
Eur J Ophthalmol ; 18(1): 66-70, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18203087

RESUMO

PURPOSE: To investigate the rate of bleb-related endophthalmitis over 5 years in a Chinese population. METHODS.:Retrospective chart review. RESULTS: Of 988 trabeculectomies performed over 5 years, one case (0.1%) developed early endophthalmitis caused by Morganella morganii, which was rarely reported in the literature. Six cases (0.6%) developed late-onset endophthalmitis. Mitomycin C significantly increased the risk of late-onset endophthalmitis (p=0.0002). CONCLUSIONS: Physicians should weigh the benefits against the risks of mitomycin C application in performing trabeculectomies.


Assuntos
Endoftalmite/microbiologia , Infecções Oculares Bacterianas/microbiologia , Complicações Pós-Operatórias , Trabeculectomia , Adulto , Idoso , Alquilantes/administração & dosagem , Antibacterianos/uso terapêutico , Povo Asiático/etnologia , China/epidemiologia , Quimioterapia Combinada , Endoftalmite/tratamento farmacológico , Endoftalmite/etnologia , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Enterobacteriaceae/etnologia , Infecções por Enterobacteriaceae/microbiologia , Infecções Oculares Bacterianas/tratamento farmacológico , Infecções Oculares Bacterianas/etnologia , Feminino , Glaucoma/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Mitomicina/administração & dosagem , Morganella morganii/isolamento & purificação , Estudos Retrospectivos , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/etnologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Infecções Estreptocócicas/tratamento farmacológico , Infecções Estreptocócicas/etnologia , Infecções Estreptocócicas/microbiologia , Estreptococos Viridans/isolamento & purificação , Corpo Vítreo/microbiologia
11.
Oncogene ; 26(29): 4272-83, 2007 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-17237822

RESUMO

A significant challenge in the post-genomic era is how to prioritize differentially expressed and uncharacterized novel genes found in hepatocellular carcinoma (HCC) microarray profiling. One such category is cell cycle regulated genes that have only evolved in higher organisms but not in lower eukaryotic cells. Characterization of these genes may reveal some novel human cancer-specific abnormalities. A novel transcript, FLJ10540 was identified. FLJ10540 is overexpressed in HCC as examined by quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. The patients with higher FLJ10540 expression had a poor survival than those with lower FLJ10540 expression. Functional characterization indicates that FLJ10540 displays a number of characteristics associated with an oncogene, including anchorage-independent growth, enhanced cell growth at low serum levels and induction of tumorigenesis in nude mice. FLJ10540-elicited cell transformation is mediated by activation of the phosphatidylinositol 3'-kinase (PI3K)/AKT pathway. Moreover, FLJ10540 forms a complex with PI3K and can activate PI3K activity, which provides a mechanistic basis for FLJ10540-mediated oncogenesis. Together, using a combination of bioinformatics searches and empirical data, we have identified a novel oncogene, FLJ10540, which is conserved only in higher organisms. The finding raises the possibility that FLJ10540 is a potential new therapeutic target for HCC treatment. These findings may contribute to the development of new therapeutic strategies that are able to block the PI3K/AKT pathway in cancer cells.


Assuntos
Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/patologia , Proteínas de Ciclo Celular/fisiologia , Transformação Celular Neoplásica/patologia , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/patologia , Proteínas Nucleares/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Carcinoma Hepatocelular/genética , Proteínas de Ciclo Celular/biossíntese , Proteínas de Ciclo Celular/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Humanos , Neoplasias Hepáticas/genética , Proteínas Nucleares/biossíntese , Proteínas Nucleares/genética , Fosfatidilinositol 3-Quinases/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Células Tumorais Cultivadas
12.
Bioelectromagnetics ; 28(1): 3-15, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17016850

RESUMO

For 35 years, I have been involved in various bioelectromagnetics research projects including acute and long-term radiofrequency (RF) bioeffects studies, dosimetry, exposure systems, MRI safety, cancer studies involving hyperthermia and electrochemical treatment, development of RF exposure and measurement standards, and product compliance. My first study demonstrated that effects on isolated nerve and muscle preparations were due to thermal effects of RF exposure. The recording of cochlear microphonics in animals shows the mechanical nature of the microwave auditory effect. In 1992, we published the results of a large-scale lifetime study in which 100 rats were sham-exposed and 100 rats were exposed for 21 h/day for 25 months to a pulsed RF signal. In dosimetry studies, human models were employed as well as many animal species including mice, rats, rabbits, monkeys, and birds of many sizes. Cancer hyperthermia studies demonstrated that knowledge of temperature distribution was crucial for successful treatment. Research on electrochemical treatment of tumors with direct current involved cellular, animal, and clinical studies. Over the past few decades, there has been rather extensive investigation of the public health impact of RF exposure. In my opinion, future research in bioelectromagnetics should place greater emphasis on medical applications.


Assuntos
Pesquisa Biomédica/história , Magnetismo/história , Proteção Radiológica/história , Radiobiologia/história , História do Século XX , História do Século XXI , Estados Unidos
13.
Acta Radiol ; 47(7): 752-4, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16950717

RESUMO

Clinically symptomatic renal capsular leiomyomas are rare. Previous research has shown that these tumors are usually well-defined cystic lesions, solid lesions, or a mixture of the two. We report an unusual case of renal capsular leiomyoma which was well defined by ultrasonography, but lacked a well-defined edge in CT. The reason for the absence of a well-defined tumor edge is probably due to degeneration in certain parts of the tumor resulting in a different degree of enhancement. Thus, the possibility of renal capsular leiomyoma should be included in the differential diagnosis whenever a renal mass is found, especially when either CT or ultrasonography shows that the tumor has a smooth, well-defined contour.


Assuntos
Neoplasias Renais/diagnóstico por imagem , Leiomioma/diagnóstico por imagem , Adulto , Meios de Contraste , Diagnóstico Diferencial , Feminino , Humanos , Neoplasias Renais/cirurgia , Leiomioma/cirurgia , Nefrectomia , Tomografia Computadorizada por Raios X , Ultrassonografia
14.
Cancer Gene Ther ; 13(8): 746-52, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16410824

RESUMO

Antitumor vaccination therapies using attenuated Salmonella typhimurium carrying plasmid DNA encoding tumor-associated antigens are currently under preclinical development. In the present study, we first established a useful method to facilitate in vivo monitoring of attenuated S. typhimurium uptake using a bioluminescent lux gene operon plasmid. Following transformation with the lux gene operon construct, mice were fed with various amounts of attenuated S. typhimurium-lux to monitor in vivo clearance over a period of 24 h. We found that the ingested attenuated S. typhimurium-lux cells were almost cleared out 9 h postfeeding, as judged by a significant decrease in bioluminescence. We further examined the therapeutic efficacy of vaccination using attenuated S. typhimurium carrying the mouse alpha-fetoprotein (AFP) gene against a cancer line CT26-murine alpha-feto protein (mAFP) that stably expresses AFP and mouse hepatocellular carcinoma (HCC) Hepa1-6. Attenuated S. typhimurium oral DNA vaccine was found to promote protective immunity against both CT26-mAFP and Hepa1-6 tumor cells growth. The oral DNA vaccine significantly increased the life span of tumor-challenged mice in both tumor models. Together, these results suggest that vaccination with the attenuated S. typhimurium oral DNA vaccine that carries the AFP gene could be a promising strategy to prevent HCC development.


Assuntos
Carcinoma Hepatocelular/prevenção & controle , Neoplasias Hepáticas/prevenção & controle , Salmonella typhimurium/imunologia , Vacinas de DNA/imunologia , alfa-Fetoproteínas/genética , Administração Oral , Animais , Antígenos de Neoplasias/imunologia , Carcinoma Hepatocelular/imunologia , Linhagem Celular , Linhagem Celular Tumoral , Neoplasias do Colo/imunologia , Neoplasias do Colo/prevenção & controle , Citotoxicidade Imunológica , Genes Bacterianos , Humanos , Tolerância Imunológica , Neoplasias Hepáticas/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Óperon , Plasmídeos , Salmonella typhimurium/genética , Linfócitos T/imunologia , Vacinas Atenuadas , Vacinas de DNA/administração & dosagem , Ensaios Antitumorais Modelo de Xenoenxerto , alfa-Fetoproteínas/imunologia
15.
Radiat Res ; 163(5): 580-90, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15850420

RESUMO

The level and distribution of radiofrequency energy absorbed in a child's head during the use of a mobile phone compared to those in an adult head has been a controversial issue in recent years. It has been suggested that existing methods that are used to determine specific absorption rate (SAR) and assess compliance with exposure standards using an adult head model may not adequately account for potentially higher levels of exposure in children due to their smaller head size. The present study incorporates FDTD computations of locally averaged SAR in two different anatomically correct adult and child head models using the IEEE standard (Std. C95.3-2002) SAR averaging algorithm. The child head models were obtained by linear scaling of the adult head model to replicate the conditions of previous studies reported in the literature and also by transforming the different adult head models based on data on the external shapes of children's heads. The tissue properties of the adult and corresponding child head models were kept the same. In addition, modeling and experimental measurements were made using three spheres filled with a tissue-equivalent mixture to approximate heads of increasing size. Results show that the peak local average SAR over 1 g and 10 g of tissue and the electromagnetic energy penetration depths are about the same in all of the head models under the same exposure conditions. When making interlaboratory comparisons, the model and the SAR averaging algorithm used must be standardized to minimize controversy.


Assuntos
Telefone Celular , Cabeça/anatomia & histologia , Cabeça/efeitos da radiação , Doses de Radiação , Ondas de Rádio , Adulto , Criança , Pré-Escolar , Humanos
16.
Eye (Lond) ; 19(7): 784-7, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15359238

RESUMO

PURPOSE: The purpose of the present study was to investigate the incidence and severity of iridial pigmentation under latanoprost topical use on brown eyes in Taiwan. METHODS: Retrospective review study was conducted from April 1999 to October 2001 in the Department of Ophthalmology, Taipei Veterans General Hospital, Taiwan, for glaucoma clinic monthly follow-up patients; 140 open-angle glaucoma patients on 0.005% latanoprost were enrolled. Analyses of iridial pigmentation incidence, grading, patient age distribution, side effect, and time course were performed. Boys-Smith pigment gradation lens was used as standard for semiquantitative iris pigmentation grading. RESULT: Before 0.005% latanoprost use, 90% of the patients enrolled were noted with iridial pigmentation grade I, and 10% were with grade I-II, but not reaching grade II scale standard. A total of 60 patients on 0.005% latanoprost developed increased pigmentation of the iris during the follow-up period. An increase of iris pigmentation was noted after an average of 7.27 months use of latanoprost (range 1-19 months, SD 2.65 months). For iridial pigmentation grading, 57.1, 30.7, 10.0, and 2.1% of our patients were noted to have grade I, II, III, and IV respectively. Most patients with latanoprost-induced iris hyperpigmentation were with grade II iridial pigmentation. There were 15 patients (10.7%) (10 female and five male) with hypertrichosis in the study group who were not compatible with the iridial pigmentation status. Among these patients, female patients had higher incidence of hypertrichosis than males, but this did not bother them. Only four patients (2.8%) were with conjunctiva chemosis and three patients (2.1%) with lid margin hyperpigmentation. CONCLUSION: Contrary to the belief that latanoprost rarely caused iris hyperpigmentation in yellow-brown eyes, our study showed that 42.8% iris hyperpigmentation did occur, especially after continual use for around 7 months. Higher hyperpigmentation incidence were noted in male than in female patients. This might be due to stronger adrenergic incidence in male than in female patients. Although hypertrichosis and increasing eyelid pigmentation together with iridial pigmentation represented a potentially permanent cosmetic side effect, they are very rare and occurred in no more than 3% in our patients. It is a good way to take Boys-Smith pigment gradation lens for iridial pigmentation grading and for long-term continual evaluation. The doctors should exert great care in differentiating drug-induced iris pigmentation and iris nevi from early stage uveal melanoma.


Assuntos
Anti-Hipertensivos/efeitos adversos , Hiperpigmentação/induzido quimicamente , Doenças da Íris/induzido quimicamente , Prostaglandinas F Sintéticas/efeitos adversos , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Glaucoma de Ângulo Aberto/tratamento farmacológico , Humanos , Hipertricose/induzido quimicamente , Latanoprosta , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Índice de Gravidade de Doença
17.
Eye (Lond) ; 19(5): 540-5, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15319791

RESUMO

PURPOSE: To investigate the impact of stereopsis on vision-related quality of life and general health status of the elderly. METHODS: A quota of 200 subjects aged 65 years or older and had their households registered in Guando district was recruited for a general physical examination including ophthalmic evaluation. A structured questionnaire consisting of seven vision-specific items as well as 36-item short-form survey of the Medical Outcomes Study (SF-36) was administered. Stereoscopic level was divided into three groups: no stereopsis, gross stereopsis, and fine stereopsis. Fisher's exact test was used to detect any difference in subjective visual functioning and Mann-Whitney U test was used for analyses of SF-36 scores. RESULTS: A total of 187 volunteers were recruited and 150 were analysed for stereoscopic levels. There was no significant difference in vision-specific difficulty among the three stereoscopic groups. For SF-36, having no stereopsis scored significantly less than having gross (P=0.005) and fine (P<0.0001) stereopsis in the vitality/energy dimension. General health perception dimension fared significantly lower in the group with no stereopsis compared to the fine stereoscopic group (P=0.01). In multivariate analysis, having fine stereopsis scored significantly higher in the energy/vitality dimension than having no stereopsis (P=0.02). On the other hand, visual impairment imposed significant adverse effect on five vision-specific items and had no significant relationship with the eight dimensions of SF-36. CONCLUSIONS: Defective stereopsis in the elderly imposes no significant adverse effect on vision-related quality of life. However, subjects may feel more exhausted in accomplishing their usual tasks.


Assuntos
Percepção de Profundidade , Qualidade de Vida , Pessoas com Deficiência Visual/reabilitação , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Feminino , Avaliação Geriátrica/métodos , Nível de Saúde , Indicadores Básicos de Saúde , Humanos , Masculino , Estatísticas não Paramétricas , Inquéritos e Questionários , Acuidade Visual
18.
Br J Radiol ; 77(921): 780-1, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15447967

RESUMO

Malignant mesothelioma of the tunica vaginalis is rare, and is usually not diagnosed until surgery is undertaken. Reports on the ultrasound features of this tumour are limited. We present an unusual case with ultrasound features mimicking an adenomatoid tumour.


Assuntos
Tumor Adenomatoide/diagnóstico por imagem , Mesotelioma/diagnóstico por imagem , Neoplasias Testiculares/diagnóstico por imagem , Adulto , Diagnóstico Diferencial , Humanos , Masculino , Ultrassonografia Doppler em Cores
19.
Abdom Imaging ; 29(1): 18-22, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15160748

RESUMO

We evaluated the computed tomographic (CT) features of small bowel (SB) ischemia and necrosis and correlated the findings with clinical outcome or patient prognosis. Sixty-eight surgically or angiographically proved cases of SB ischemia were retrospectively reviewed. The CT features of intestinal ischemia were divided into three groups: (A) thinned bowel wall with poor enhancement, intramural gas, or portal venous gas; (B) thickened SB wall without superior mesenteric vein thrombosis; and (C) thickened SB wall with superior mesenteric vein thrombosis or intussusception. The evaluated factors included bowel wall or mucosal enhancement pattern, SB dilatation, mesenteric edema, and CT evidence of narrowing or occlusion of the superior mesenteric artery or vein. The bowel necrosis rates and mortalities were compared with chi-square test. Oral contrast material was not administered. Intramural gas and SB dilatation were associated with a higher bowel necrosis rate (eight of eight, 100%, and 17 of 21, 81%, respectively) in group A. Poor mucosal enhancement of the thickened bowel wall indicated a higher bowel necrosis rate in groups B (six of seven, 86%) and C (12 of 12, 100%) than did normal mucosal enhancement. Only intramural gas was accompanied with a higher mortality (six of eight, 75%). Intramural gas of a thinned bowel wall and poor mucosal enhancement of a thickened small bowel wall are useful signs of bowel necrosis. Intramural gas would indicate poor patient prognosis.


Assuntos
Intestino Delgado/irrigação sanguínea , Isquemia/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Feminino , Gases , Humanos , Intestino Delgado/diagnóstico por imagem , Intestino Delgado/fisiologia , Masculino , Prognóstico , Estudos Retrospectivos
20.
Br J Radiol ; 77(915): 250-2, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15020370

RESUMO

Rhabdomyosarcoma is the most common tumour of the lower genitourinary tract in children in the first two decades. Paratesticular rhabdomyosarcoma is associated with a significantly better outcome than lesions elsewhere in the genitourinary tract. Although ultrasound is considered the imaging modality of choice for evaluating intrascrotal pathology, the ultrasound appearance of paratesticular rhabdomyosarcoma has rarely been reported and may be confused with other disease entities such as epididymitis, adenomatoid tumour and leiomyoma. We present the ultrasound features of a paratesticular rhabdomyosarcoma, discussing the clinical features and differential diagnosis.


Assuntos
Neoplasias dos Genitais Masculinos/diagnóstico por imagem , Rabdomiossarcoma/diagnóstico por imagem , Escroto/diagnóstico por imagem , Adolescente , Diagnóstico Diferencial , Humanos , Masculino , Ultrassonografia Doppler em Cores
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