Nanomedicine for acute respiratory distress syndrome: The latest application, targeting strategy, and rational design

Acute respiratory distress syndrome (ARDS) is characterized by the severe inflammation and destruction of the lung air-blood barrier, leading to irreversible and substantial respiratory function damage. Patients with coronavirus disease 2019 (COVID-19) have been encountered with a high risk of ARDS, underscoring the urgency for exploiting effective therapy. However, proper medications for ARDS are still lacking due to poor pharmacokinetics, non-specific side effects, inability to surmount pulmonary barrier, and inadequate management of heterogeneity. The increased lung permeability in the pathological environment of ARDS may contribute to nanoparticle-mediated passive targeting delivery. Nanomedicine has demonstrated unique advantages in solving the dilemma of ARDS drug therapy, which can address the shortcomings and limitations of traditional anti-inflammatory or antioxidant drug treatment. Through passive, active, or physicochemical targeting, nanocarriers can interact with lung epithelium/endothelium and inflammatory cells to reverse abnormal changes and restore homeostasis of the pulmonary environment, thereby showing good therapeutic activity and reduced toxicity. This article reviews the latest applications of nanomedicine in pre-clinical ARDS therapy, highlights the strategies for targeted treatment of lung inflammation, presents the innovative drug delivery systems, and provides inspiration for strengthening the therapeutic effect of nanomedicine-based treatment.

Blood typing in positive DEA 1 dogs: comparative analysis between immunochromatography, hemagglutination and flow cytometry / Tipificação sanguínea em cães AEC 1 positivo: análise comparativa entre a imunocromatografia, hemoaglutinação e citometria de fluxo

Blood typing techniques have been improved to ensure greater safety for transfusion procedures. Typification for the DEA 1 antigen through flow cytometry should offer more reliability to routine immunohematology in donor and recipient dogs. Currently, the DEA 1 group is starting to be an autosomal dominant allelic system with the DEA 1 negative type and its variations of positivity. The present study investigated the DEA 1 antigen using the techniques of immunochromatography, hemagglutination and flow cytometry. Among the positive animals for the DEA 1 group, typified by flow cytometry, medium intensities of fluorescence were found, which are indicative of weak, moderate and strong antigenicity. This enabled the division of the DEA 1 group into weak positive, moderate positive and strong positive. The blood typing techniques for the DEA 1 group by flow cytometry, agglutination and immunochromatography had positive (Spearman r=0.70) and statistically significant (p>0.0001) correlations.(AU)

As técnicas de tipificação sanguínea vêm sendo aperfeiçoadas para garantir maior segurança aos procedimentos transfusionais. A tipificação para o antígeno AEC 1 com o emprego da citometria de fluxo poderá oferecer mais confiabilidade à rotina da imunohematologia em cães doadores e receptores. Na atualidade, o grupo AEC 1 passou a ser denominado como um sistema alélico autossômico dominante com o tipo AEC 1 negativo e suas variações de positividade. O presente trabalho comparou os resultados de três técnicas utilizadas para a pesquisa do antígeno AEC 1: cromatografia; hemoaglutinação e citometria de fluxo. Dentro dos indivíduos positivos para o grupo AEC 1, tipificados pela citometria de fluxo, foram encontradas intensidades médias de fluorescência indicadoras de antigenicidade fraca, moderada e forte, podendo-se dividir o grupo AEC 1 em positivo fraco, positivo moderado e positivo forte. As técnicas de tipificação sanguínea para o grupo AEC 1 por cromatografia, hemoaglutinação e citometria de fluxo apresentaram correlação positiva (Spearman r=0,70) e estatisticamente significativa (p<0,0001).(AU)

Frequency of dog erythrocyte antigen 1 blood group and risk of incompatible transfusion in dogs of different breeds and mongrels from the city of Salvador - BA, Brazil / Frequência do antígeno eritrocitário canino 1 e risco de transfusão incompatível em cães de diferentes raças e mestiços da cidade de Salvador-BA, Brasil

The dog erythrocyte antigen 1 (DEA 1) is the most immunogenic blood group in dogs, and blood transfusions may trigger some undesirable effects in veterinary patients, which are directly associated with incompatible transfusions. The present study aimed to investigate the frequency of positive DEA 1 blood group in blood donor dogs from a blood bank in Salvador, Bahia, Brazil, and also to calculate the risk of managing incompatible blood in both first and second transfusion. A number of 203 dogs of different breeds, aged between 1 and 8 years, weighing 28 kg, with no degree of kinship and of both sexes in Salvador - BA, Brazil were evaluated to investigate the blood type DEA 1 frequency, by means of chromatography and flow cytometry tests for blood typing. The risk of incompatible blood transfusion in either a first or a second transfusion was also calculated. The frequency of the DEA 1 group ranged from 0% to 100% in various breeds, but with a mean positivity of 62.07% (126/203). And the lowest risk of an DEA 1 negative animal receiving DEA 1 positive blood within the group of animals evaluated was 0.92% at a first transfusion; and the risk of the same animal receiving incompatible blood for the DEA group 1 in the second transfusion was 0.008%. The highest risk of an DEA 1 negative animal receiving DEA 1 positive blood from these animals was 69.12%; and the risk of receiving incompatible blood for DEA 1 was 47.77%. In conclusion, the frequency of the DEA 1 group varied between the studied breeds and the risk of incompatible blood transfusions varies according to donor and recipiente breeds, but this can be overridden if blood typing tests are performed along with the cross-reaction test for compatibility.

O antígeno eritrocitário canino 1 (AEC 1) é o grupo sanguíneo mais imunogênico em cães, podendo as transfusões sanguíneas desencadearem alguns efeitos indesejáveis nos pacientes veterinários. Estes estão diretamente associados à transfusões incompatíveis. O presente trabalho teve como objetivo estudar a frequência do grupo sanguíneo AEC 1 em cães doadores de sangue de um banco de sangue de Salvador-BA, Brasil, e calcular o risco de administrar sangue incompatível tanto em uma primeira quanto em uma segunda transfusão. Foram avaliados 203 cães de diversas raças, de ambos os sexos, com idade entre 1 e 8 anos, peso a partir de 28 kg, sem nenhum grau de parentesco originários de Salvador ­ BA, Brasil, para pesquisa da frequência do tipo sanguíneo AEC 1, por meio de testes de imunocromatografia e citometria de fluxo para tipagem sanguínea. E calculado o risco de transfusão sanguínea incompatível tanto em uma primeira como em uma segunda transfusão. A frequência do grupo AEC 1 variou entre as raças estudadas de 0% a 100%, porém com uma positividade média de 62,07% (126/203). O menor risco de um animal AEC 1 negativo receber sangue AEC 1 positivo, dentro do grupo dos animais avaliados foi de 0,92% em uma primeira transfusão e o risco do mesmo animal receber sangue incompatível para o gruo AEC 1 na segunda transfusão foi de 0,008%. Quanto ao maior risco de um animal AEC 1 negativo receber sangue AEC 1 positivo destes animais foi de 69,12% e o risco do mesmo receber sangue incompatível para o AEC 1 foi de 47,77%. A frequência do grupo AEC 1 variou entre as raças estudadas e o risco de transfusões incompatíveis variou de acordo com as raças doadoras e receptoras, mas esse risco pode ser anulado se sempre forem realizados os testes para tipagem sanguínea junto com a prova de reação cruzada para compatibilidade.

Detection of canine anti-DEA 1 antibodies using flow cytometry in dogs following DEA 1-positive blood transfusion / Detecção de anticorpos caninos anti-AEC 1 por citometria de fluxo em cães pós-transfundidos com sangue AEC 1 positivo

The shortage of dog blood donors in veterinary emergencies can lead to blood transfusions between animals whose blood type has not been identified. The antibody profile serves as a warning sign for animals that require a second blood transfusion, which is only advisable from compatible donor dogs. This article focuses on determination of anti-DEA 1 antibodies using the flow cytometry technique in dogs that have undergone a transfusion using DEA 1-positive blood, compared to results obtained from crossmatching. Blood from 18 DEA 1-positive donors ranked according to the chromatographic technique was used to transfuse thirty-three animals with unknown blood types and which demonstrated negative crossmatching to donors. On post-transfusion days 7, 14, 21 and 28, 45% and 27% of the animals tested positive for the anti-DEA 1 antibody, through crossmatching and flow cytometry, respectively. Detecting antibodies using the flow cytometric technique has high specificity and sensitivity, while crossmatching methods are highly sensitive but manifest low specificity. Following blood transfusion, animals that did not present as positive through crossmatching or flow cytometry were considered different from all other DEA 1-positive blood groups.(AU)

A escassez de cães doadores de sangue em situações de emergência na Medicina Veterinária pode levar a realização de transfusões de sangue entre animais que não tiveram seu tipo sanguíneo previamente determinado. O padrão de anticorpos serve como um sinal de alerta para animais que serão submetidos a uma segunda transfusão sanguínea, sendo essa somente recomendável a partir de cães doadores compatíveis. Este artigo aborda a pesquisa de anticorpos anti-AEC 1 pela técnica de citometria de fluxo em cães que receberam uma transfusão utilizando sangue do grupo AEC 1 positivo, comparando os resultados com aqueles obtidos a partir de reação cruzada. Foi utilizado sangue de 18 animais doadores do tipo AEC 1 positivo classificados por técnica cromatográfica para transfundir trinta e três animais com tipos sanguíneos desconhecidos, os quais mostraram reação cruzada negativa aos doadores. Nos dias 7, 14, 21 e 28 pós-transfusão, 45% e 27% dos animais mostraram-se positivos para os anticorpos anti-AEC 1, respectivamente, pela reação cruzada e através de citometria de fluxo. A pesquisa de anticorpos com o emprego da técnica de citometria de fluxo tem alta especificidade e sensibilidade, enquanto a reação cruzada, altamente sensível, tem baixa especificidade. Animais que não apresentaram positividade após a transfusão de sangue na reação cruzada e na citometria de fluxo concomitantemente foram considerados de qualquer outro grupo sanguíneo diferente do grupo sanguíneo AEC 1 positivo.(AU)

Effect of co-culture with amniotic epithelial cells on biological characteristics of amniotic mesenchymal stem cells / 中国肿瘤生物治疗杂志

@# Objective: The aim of this study was to investigate the effect of co-culture with AEC (amniotic epithelial cell) on the biological characteristics of AMSC (amniotic mesenchymal stem cell), and to investigate the roles of SDF-1/CXCR4 axis in the homing and migration of AMSC. Methods: AMSC andAEC were isolated from human amnion, and then cultured, amplified and identified, respectively. TheAMSC were divided into three groups:AEC co-cultured group, serum-free cultured group and serum cultured group.After culture for 24 h, 48 h, and 72 h, the proliferation viability ofAMSC was measured by CCK-8 assay and trypan blue staining; the expression of CXCR4 mRNAwas analyzed by flow cytometry and Real-time RT-PCR, and the migration ability ofAMSC in vitro was observed by migration assay. Results: Cell viability (48 h and 72 h) and survival rate in the co-culture and serum groups were higher than those in the serum-free group (all P<0.05). The mRNA and protein expressions of CXCR4 in AMSC of the co-culture and serum-free groups were significantly higher than those of the serum group (P<0.05). The migration ability of AMSC in the co-culture and serumfree groups, which increase with the SDF-1 (stromal cell derived factor-1) concentration gradient, were higher than that in the serum group (P<0.05). Conclusion: AMSC co-cultured with AEC still have the basic biological characteristics of MSC, and showed good growth activity. Co-culture withAEC can up-regulate CXCR4 onAMSC surfaces and enhance the migration ability ofAMSC in vitro.

Repair effect of Qinbai Qingfei concentrated pellets to AEC-Ⅱ of rats infected by Mycoplasmal pneumonia / 中国中药杂志

To discuss the repair mechanism of Qinbai Qingfei concentrated pellets to AEC-Ⅱ of rats infected by mycoplasma through the observation of the changes and distribution of TGF-β and SP-A in lungs, totally 60 Wistar rats that weighing 80-100 g were collected, with male and female in half. The rats were divided into six groups randomly, with 10 rats each group, namely blank group, model group, positive group and Qinbai Qingfei concentrated pellets high, middle and low dose groups. Rats were infected through nasal intubation drip of MP. After 10 days of administration, serum and bronchoalveolar lavage fluid (BALF) were collected to detect the concentration of surface activity related protein A (SP-A) by ELISA, left pulmonary tissues of rats were collected to observe the expression and distribution of transforming growth factor-beta (TGF-β) and SP-A by immunohistochemistry, and right pulmonary tissues were taken to detect TGF-β and SP-A mRNA expression level by real-time quantitative PCR (RT-PCR). Qinbai Qingfei concentrated pellets can reduce the expression of TGF-β and increase the expression of SP-A in the lung tissues of rats infected by mycoplasma. Specifically, TGF-β was mainly distributed among the lung interstitium, while SPAs were mainly distributed in AEC-II and parts of alveolar macrophage. The level of SP-A was reduced in serum and increased in BALF in rats in Qinbai Qingfei concentrated pellets groups. It was proved that Qinbai Qingfei concentrated pellets can restore the normal morphology and function of the lung by reducing the content of TGF-β to inhibit epithelial-mesenchymal transition (EMT) of alveolar type II epithelial cells and increasing the expression of SP-A. Qinbai Qingfei concentrated pellets have the repairing ability to capillary vessel damage caused by MP in lung tissues of rats.

Spinocerebellar ataxia type 10 in the South of Brazil: the Amerindian-Belgian connection / Ataxia espinocerebelar tipo 10 no sul do Brasil: a conexão Ameríndia-Belga

Spinocerebellar ataxia type 10 (SCA10) is a rare form of autosomal dominant ataxia found predominantly in patients from Latin America with Amerindian ancestry. The authors report the history of SCA10 families from the south of Brazil (the states of Paraná and Santa Catarina), emphasizing the Belgian-Amerindian connection.

A ataxia espinocerebellar tipo 10 (AEC10) é uma forma rara de ataxia cerebelar autossômica dominante, encontrada predominantemente em pacientes da América Latina, de origem Ameríndia. Os autores relatam a história de famílias com AEC10 do sul do Brasil (estados do Paraná e Santa Catarina), enfatizando a conexão Ameríndia-Belga.

Indonesia health care system and Asean economic community.

ASEAN Economic Community (AEC) is a trend issue among ten member countries, including Indonesia. AEC is expected to bring ten member countries close together. To the success of AEC, Indonesia has a role in promoting trade areas and service across boundaries. However, the profile of the countries is needed in order to learn, work, and collaborate among member countries. Therefore, this paper aims to describe Indonesian country, its health system, the production and distribution of health professionals, and some concerns related to AEC. Indonesia, with its population of over 250 million, has health problems and challenges related to health care system. Nowadays, Indonesia is in the process of effective decentralization and in the effort of achieving Universal Health Coverage. Indonesia has made some progress in increasing the life expectancy, and the maternal and infant mortality rate is dropped compared to previous years. In improving healthcare service, Indonesia has been increased the number of health professionals to meet the growth demand. However, the gap of number of physician and nurses still exist. Unequal distribution and shortage of physician and nurses are the major concerns, including the surplus of nurses. Indonesian government proposes the program of worker contract scheme or Pegawai Tidak Tetap (PTT) to solve unequal distribution of health professionals, and provide the program for nurse mobility to migrate to other countries such as Japan, United Emirate Arab (UEA), Kuwait, the Netherlands, Great Britain, Brunei, and other Middle East countries to decrease the number of surplus. However, AEC, by looking at this challenges, is expected to improve health care system and service in Indonesia, and close the gap by collaborating among ten ASEAN member countries through 4 modes of AEC consisting of cross border supply, consumption abroad, commercial presence, and movement of natural persons.

Estudo da frequência dos antígenos eritrocitários caninos 1, 1.1 e 7 e risco de transfusão incompatível em cães de diferentes raças e mestiços da região metropolitana da cidade de São Paulo-SP, Brasil / Study of the frequency on the dog erythrocyte antigen 1, 1.1 and 7 and incompatible transfusion risk in different dog breeds and mongrel dogs of the metropolitan region of São Paulo-SP, Brazil

O presente trabalho estudou a frequência dos grupos sanguíneos identificados como antígenos eritrocitários caninos (AEC) 1, 1.1 e 7 em cães da região metropolitana da cidade de São Paulo-SP, Brasil, e calculou o risco de administração de sangue incompatível tanto em uma primeira quanto em uma segunda transfusão. Para tanto, 300 cães não aparentados foram divididos igualmente em seis grupos de acordo com as raças: Pastor Alemão (PA); Rottweiler (R); Poodle (P); Cocker Spaniel Inglês (CS); raças definidas diversas (RDD) e mestiços (M). Foi avaliada a relação entre a frequência dos AEC e os grupos raciais. A frequência geral de AEC 1 na população foi de 71 por cento (AEC 1.1 – 53,35 por cento) e houve variações de acordo com as raças: PA- 32 por cento (AEC 1.1 – 20 por cento), R- 98 por cento (1.1 – 80 por cento), P- 76 por cento (1.1 – 54 por cento), CS- 84 por cento (1.1 – 50 por cento), RDD- 62 por cento (1.1 – 56 por cento) e M- 74 por cento (1.1 – 60 por cento). A frequência geral de AEC 7 foi de 39,33 por centoe não houve diferenças significativas entre as raças. O risco de um cão negativo para o AEC 1 receber sangue positivo foi de 0,6 a 66,6 por cento em uma primeira transfusão e de 0,21 a 65,3 por cento do mesmo cão receber sangue incompatível em uma segunda transfusão. O risco quanto ao AEC 7 foi de 23,86 por cento na primeira transfusão e 9,4 por cento numa segunda transfusão. Este trabalho concluiu que houve variação na frequência de AEC1 e AEC 1.1, mas não quanto ao AEC 7 entre raças. Esta variação na porcentagem de animais positivos quanto ao AEC 1 se refletiu na grande variação no risco de uso de sangue incompatível. Portanto, conhecer a frequência dos AEC na população tem impacto direto no manejo entre cães doadores e receptores, mas a utilização conjunta de teste de tipagem sanguínea e reação cruzada reduz a possibilidade de transfusão de sangue incompatível.

It was investigated the frequency of blood groups identified as Dog Erythrocyte Antigens (DEA) 1, 1.1 and 7 dogs in the metropolitan region of São Paulo-SP, Brazil, and calculated the risk of administering incompatible blood in both first and second transfusion. For both, 300 unrelated dogs were equally divided into six groups according to the breeds: German Shepherd (GS), Rottweiler (R) Poodle (P), Cocker Spaniel (CS); defined several races (DSR), mongrel dogs (M). It was evaluated the relationship between the frequency of AEC and racial groups. The overall frequency of DEA 1 in population was 71 percent (DEA 1.1 – 53.35 percent) and there were variations according to the breeds: GS- 32 percent (DEA 1.1 – 20 percent), R –98 percent (1.1 – 80 percent) P – 76 percent (1.1 – 54 percent), CS-84 percent (1.1 – 50 percent), DSR- 62 percent (1.1 – 56 percent) and M – 74 percent(1.1 – 60 percent). The overall frequency of BCE 7 was 39.33 percent, and there were no significant differences between the breeds. The risk of a dog negative DEA receiving 1 positive blood was 0.6 to 66.6 percent in the first transfusion and 0.21 to 65.3 percent from the same animal dog receiving incompatible blood transfusion in a second. The risk of the DEA 7 was 23.86 percent in the first transfusion and 9.4 percent in a second transfusion. This study concluded that there was variation in the frequency of DEA 1 and 1.1, but not on the DEA 7 between races. This variation in the percentage of positive animals to DEA 1 was reflected in the large variation in the risk of use of incompatible blood. Therefore, knowing the frequency of the DEA in the population has a direct impact on handling dogs between donors and recipients, but the joint use of testing blood typing and cross-reactivity reduces the possibility of incompatible blood transfusion.

Evaluation of dry eye syndrom in C57BL/6.NOD-Aec1Aec2 mice / 中华实验眼科杂志

Background C57BL/6.NOD-Aec1Aec2 mouse is considered to be an idea model for the study of the pathogenesis of Sj(o)gren syndrome,but the cause of dry eye in these mice is unclear.Objective This study was to investigate the histopathological change of the ocular surfaces of C57BL/6.NOD-Aec1Aec2 mice,and to determine whether dry eye is developed spontaneously in these mice.Methods Forty-five clean C57BL/6.NOD-Aec1 Aec2 mice were used as the experiment group and forty-five C57BL/6J mice(both male and female)were used as the control group in this study.Detection of fasting blood-glucose,Schirmer' s test Ⅰ (S Ⅰ t),lissamine green staining and scoring of the corneal and conjunctival epithelium in the mice were performed at the age of 4,8,12,16 and 20weeks.Five mice from each group were sacrificed and their corneas were obtained to measure the central corneal epithelium thickness and to count the number of conjunctival goblet cells.In addition,lymphocyte infiltration in the lacrimal gland of the mice was examined with hematoxylin-eosin staining.The uhrastructure of the corneal epithelial cells and microvilli were assessed by scanning electron microscopy.The use and care of the mice were approved by the Experimental Animal Care Committee of the Third Military Medical University.Results No sign of dry eye was seen in both the 4-week-old C57BL/6.NOD-Aec1Aec2 mice and 4-week-old C57BL/6J mice.The S Ⅰ t values in 8-week-old,12-week-old,16-week-old and 20 week-old mice from the experiment group were (2.7 ±0.9) mm,(2.5 ±0.8) mm,(1.8±0.6) mm and (1.9± 0.1) mm,respectively,showing a significant reduction in comparison with those of the control mice of the same age(all P＜0.01).The amount of lissamine green staining in the C57BL/6.NOD-Aec1Aec2 mice gradually increased with age,showing elevated scores in 12-week-old,16-week-old and 20-week-old mice in the experiment group(all P＜0.01).The central corneal epithelium thicknesses were(20.18±3.75)μm,(17.01 ±5.25) μm,(14.19±5.72) μm and(12.00±3.25) μm in the 8-week-old,12-week-old,16-week-old and 20-week-old C57BL/6.NOD-Aec1Aec2 mice,respectively,which were significantly lower than those of the C57BL/6Jmice of the same age (all P＜0.01).The numbers of conjunctival goblet cells were (8.2±2.4),(6.2±2.1),(6.1 ±2.2) and (4.1 ± 2.0) in the 8-week-old,12-week-old,16-week-old and 20-week-old C57 BL/6.NOD-Aec 1Aec2 mice,respectively,showing a gradual decrease with age and a significant decline in comparison with those of the C57BL/6Jmice of the same age(all P＜0.01).Lymphocyte infiltration in the lacrimal gland and destruction of gland ducts were seen by hematoxylin-eosin staining,and acinar abnormality aggravated with aging.Reduction of corneal epithelial cells and the number of microvilli were distinguished with aging under the scanning electron microscope.The fasting bloodglucose levels of the two groups were both less than 6.0 mmol/L,and no significant difference was found between them at any age(P=0.637,0.610,0.163,0.086,0.938).Conclusions C57BL/6.NOD-Aec1Aec2 mice develop dry eye spontaneously with aging.The course of disease and characteristics of dry eye in C57BL/6.NOD-Aec1Aec2mice is similar to human dry eye.The C57BL/6NOD-Aec1 Aec2 mouse is the perfect model to study the pathogenesis of dry eye.

Ankyloblepharon, Ectodermal Defects, and Cleft Lip and Palate Syndrome Associated with TP63 Gene Mutation / 대한피부과학회지

Ankyloblepharon, Ectodermal defects, and Cleft lip and palate (AEC) syndrome, also known as Hay-Wells syndrome, is a rare form of ectodermal dysplasia initially described by Hay and Wells in 1976. It is an autosomal dominant disorder caused by mutations in the gene encoding the TP63 transcription factor, specifically in the Sterile Alpha Motif (SAM) domain. It is characterized by congenital ectodermal dysplasia, including alopecia, scalp infections, dystrophic nails, hypodontia, ankyloblepharon and cleft lip and/or cleft palate. To our knowledge, no case of AEC syndrome associated with a TP63 gene mutation has ever been published in Korea. Herein, we present a Korean female infant with AEC syndrome due to a novel TP63 gene mutation.

Reducing of Craniofacial Radiation Dose Using Automatic Exposure Control Technique in the 64 Multi-Detector Computed Tomography / 의학물리

The purpose of this study was to evaluate the usefulness of reducing of craniofacial radiation dose using automatic exposure control (AEC) technique in the 64 multi-detector computed tomography (MDCT). We used SOMATOM Definition 64 multi-detector CT, and head of whole body phantom (KUPBU-50, Kyoto Kagaku CO. Ltd). The protocol were helical scan method with 120 kVp, 1 sec of rotation time, 5 mm of slice thickness and increment, 250 mm of FOV, 512x512 of matrix size, 64x0.625 mm of collimation, and 1 of pitch. The evaluation of dose reducing effect was compared the fixed tube current of 350 with AEC technique. The image quality was measured the noise using standard deviation of CT number. The range of craniofacial bone was to mentum end from calvaria apex, which devided three regions: calvaria~superciliary ridge (1 segment), superciliary ridge~acanthion (2 segment), and acanthion~mentum (3 segment). In the fixed tube current technique, CTDIvol was 57.7 mGy, DLP was 640.2 mGy.cm in the all regions. The AEC technique was showed that 1 segment were 30.7 mGy of CTDIvol, 340.7 mGy.cm of DLP, 2 segment were 46.5 mGy of CTDIvol, 515.0 mGy.cm of DLP, and 3 segment were 30.3 mGy of CTDIvol, 337.0 mGy.cm of DLP. The standard deviation of CT number was 2.622 with the fixed tube current technique and 3.023 with the AEC technique in the 1 segment, was 3.118 with the fixed tube current technique and 3.379 with the AEC technique in the 2 segment, was 2.670 with the fixed tube current technique and 3.186 with the AEC technique in the 3 segment. The craniofacial radiation dose using AEC Technique in the 64 MDCT was evaluated the usefulness of reducing for the eye, the parotid and thyroid with high radiation sensitivity particularly.

Is Weight-Based Adjustment of Automatic Exposure Control Necessary for the Reduction of Chest CT Radiation Dose?

OBJECTIVE: To assess the effects of radiation dose reduction in the chest CT using a weight-based adjustment of the automatic exposure control (AEC) technique. MATERIALS AND METHODS: With Institutional Review Board Approval, 60 patients (mean age, 59.1 years; M:F = 35:25) and 57 weight-matched patients (mean age, 52.3 years, M:F = 25:32) were scanned using a weight-adjusted AEC and non-weight-adjusted AEC, respectively on a 64-slice multidetector CT with a 0.984:1 pitch, 0.5 second rotation time, 40 mm table feed/rotation, and 2.5 mm section thickness. Patients were categorized into 3 weight categories; 90 kg (n = 48). Patient weights, scanning parameters, CT dose index volumes (CTDIvol) and dose length product (DLP) were recorded, while effective dose (ED) was estimated. Image noise was measured in the descending thoracic aorta. Data were analyzed using a standard statistical package (SAS/STAT) (Version 9.1, SAS institute Inc, Cary, NC). RESULTS: Compared to the non-weight-adjusted AEC, the weight-adjusted AEC technique resulted in an average decrease of 29% in CTDIvol and a 27% effective dose reduction (p 91 kg weight groups, respectively, compared to 20.3, 27.9 and 32.8 mGy, with non-weight-adjusted AEC. No significant difference was observed for objective image noise between the chest CT acquired with the non-weight-adjusted (15.0 +/- 3.1) and weight-adjusted (16.1 +/- 5.6) AEC techniques (p > 0.05). CONCLUSION: The results of this study suggest that AEC should be tailored according to patient weight. Without weight-based adjustment of AEC, patients are exposed to a 17 - 43% higher radiation-dose from a chest CT.