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31.
Herrera EA Riquelme RA Sanhueza EM Gajardo C Parer JT Llanos AJ 《High altitude medicine & biology》2000,1(3):175-184
The fetal llama has a marked increase in the peripheral vascular resistance and no augmentation of brain blood flow during hypoxemia. In spite of the substantial plasma arginine-vasopressin (AVP) increase during hypoxemia, up to 8 times greater than in fetal sheep, there are no changes of carotid and femoral blood flows during hypoxemia with a V1 receptor blockade, as is seen in the fetal sheep. The aim of this study was to assess the role of AVP function in mediating the combined ventricular output and organ blood flow in the hypoxemic llama fetus. Six fetal llamas at 0.65 of gestation were instrumented under general anesthesia, and cardiorespiratory responses and blood flows determined under normoxemic and hypoxemic conditions. The AVP effect was determined using a V1 antagonist during normoxemic and hypoxemic conditions. Organ blood flows were measured with the radioactive microsphere technique. No significant differences in organ blood flow or in their vascular resistances were seen between the control and treated fetuses during hypoxemia. We conclude that V1 blockade did not have any important role in the cardiovascular response to acute hypoxemia in the llama fetus, in contrast with lowland fetuses. AVP may be playing a role in other regions, possibly in kidney or lung, during hypoxemia. 相似文献
32.
The recognition of human papilloma virus (HPV)-induced cervicovaginal condylomatous lesions is in a period of dynamic development. It is estimated that condylomatous involvement of the uterine cervix is epidemic and that is particularly true in the younger, more sexually active woman. While cervical condylomas are often associated with cervical dysplasia, carcinoma in situ, or even invasive carcinoma, they are sometimes misdiagnosed as these entities. Four cases of cervical condylomas are presented that were clinically suspicious for malignancy and initially interpreted as squamous carcinomas on the basis of the histopathological findings. 相似文献
33.
Beu P. Oropeza Carlos Serna III Michael E. Furth Luis H. Solis Cesar E. Gonzalez Valeria Altamirano Daisy C. Alvarado Jesus A. Castor Jesus A. Cedeno Dante Chaparro Vega Octavio Cordova Isaac G. Deaguero Erwin I. Delgado Mario F. Garcia Duarte Mirsa Gonzalez Favela Alba J. Leyva Marquez Emilio S. Loera Gisela Lopez Fernanda Lugo Tania G. Miramontes Erik Munoz Paola A. Rodriguez Leila M. Subia Arahim A. Zuniga Herrera Thomas Boland 《Materials》2022,15(13)
The rapidly growing field of tissue engineering hopes to soon address the shortage of transplantable tissues, allowing for precise control and fabrication that could be made for each specific patient. The protocols currently in place to print large-scale tissues have yet to address the main challenge of nutritional deficiencies in the central areas of the engineered tissue, causing necrosis deep within and rendering it ineffective. Bioprinted microvasculature has been proposed to encourage angiogenesis and facilitate the mobility of oxygen and nutrients throughout the engineered tissue. An implant made via an inkjet printing process containing human microvascular endothelial cells was placed in both B17-SCID and NSG-SGM3 animal models to determine the rate of angiogenesis and degree of cell survival. The implantable tissues were made using a combination of alginate and gelatin type B; all implants were printed via previously published procedures using a modified HP inkjet printer. Histopathological results show a dramatic increase in the average microvasculature formation for mice that received the printed constructs within the implant area when compared to the manual and control implants, indicating inkjet bioprinting technology can be effectively used for vascularization of engineered tissues. 相似文献
34.
Prada Diddier Baccarelli Andrea A. Terry Mary Beth Valdéz Leonora Cabrera Paula Just Allan Kloog Itai Caro Haydee García-Cuellar Claudia Sánchez-Pérez Yesennia Cruz Rodrigo Diaz-Chávez Jose Cortés Carlo Pérez Delia Meneses-García Abelardo Cantú-de-León David Herrera Luis A. Bargalló Enrique 《Breast cancer research and treatment》2021,187(2):525-533
Breast Cancer Research and Treatment - Many patients seek breast reconstruction following mastectomy. Debate exists regarding the best reconstructive option. The authors evaluate outcomes comparing... 相似文献
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37.
Valentina Hernndez Davor Ibarra Johan F. Triana Bastian Martínez-Soto Matías Faúndez Diego A. Vasco Leonardo Gordillo Felipe Herrera Claudio García-Herrera Alysia Garmulewicz 《Materials》2022,15(11)
This article focuses on agar biopolymer films that offer promise for developing biodegradable packaging, an important solution for reducing plastics pollution. At present there is a lack of data on the mechanical performance of agar biopolymer films using a simple plasticizer. This study takes a Design of Experiments approach to analyze how agar-glycerin biopolymer films perform across a range of ingredients concentrations in terms of their strength, elasticity, and ductility. Our results demonstrate that by systematically varying the quantity of agar and glycerin, tensile properties can be achieved that are comparable to agar-based materials with more complex formulations. Not only does our study significantly broaden the amount of data available on the range of mechanical performance that can be achieved with simple agar biopolymer films, but the data can also be used to guide further optimization efforts that start with a basic formulation that performs well on certain property dimensions. We also find that select formulations have similar tensile properties to thermoplastic starch (TPS), acrylonitrile butadiene styrene (ABS), and polypropylene (PP), indicating potential suitability for select packaging applications. We use our experimental dataset to train a neural network regression model that predicts the Young’s modulus, ultimate tensile strength, and elongation at break of agar biopolymer films given their composition. Our findings support the development of further data-driven design and fabrication workflows. 相似文献
38.
Acute otomastoiditis and its complications: role of CT 总被引:2,自引:0,他引:2
Acute bacterial (suppurative) otomastoiditis responds to antibiotic treatment; radiologic study is required only when there is clinical suggestion of coalescent mastoiditis, intracranial complications, or an underlying chronic disease. Computed tomography (CT) is the method of choice for evaluating otogenic intra- or extra-cranial complications. CT scans can show stages of disease progression when infection has spread by way of soft tissue, blood, and bone pathways into the dural venous sinuses, meninges, labyrinth, facial nerves, epidural and other intracranial spaces. When there is clinical suggestion of acute coalescent mastoiditis, a CT scan of the temporal bone can confirm the presence of rarefying osteitis, coalescence of the air cells, and subperiosteal abscess. 相似文献
39.
Summary
Objective. To evaluate the clinical presentation, tumour response, clinical improvement and complications in 12 children and young people
with a pilocytic astrocytoma, WHO I grade 1, who were treated with interstitial radiosurgery using Iodine-125 seed implants.
Patients and Methods. Retrospective analysis of 12 patients aged under 18 years (mean 8.4 years, ranging from 8 months to 17 years of age) with
a pilocytic astrocytoma treated between 1993 and 2006. Iodine-125 seeds were used as temporary implants with low-dose rate
(≤10 cGy/h) and a calculated reference dose of 60 and 100 Gy to the outer ring of the tumour.
Results. There was no perioperative mortality. Two patients worsened transiently, but thereafter each patient improved clinically.
Eleven out of 12 tumours shrank after the treatment. The mean volume of the tumours before implantation was 17.9 cm3. and was reduced to 60% of this volume at 6 months, to 26.5% at 12 months, to 8% at 24 months, and was less than 1% at 30–36
months One patient underwent a reimplantation to treat a recurrence 3 years after the initial treatment. Ten patients were
alive 2 years after the first intervention. In the longest surving patient, there was no evidence of progression after 13.4
years of follow up. 相似文献
40.
目的 探讨数字化导航模板辅助全膝关节置换的准确性和可行性。方法 取成年尸体下肢标本 20具,随机分为导航模板组和传统方法组,每组 10具 20个膝关节。导航模板组术前行下肢全长 CT扫描,利用逆向工程软件对 CT数据进行处理,设计与股骨远端和胫骨近端匹配的可定位截骨平面和外旋轴的导航模板,通过快速成型机制作模板实物用于尸体标本的全膝关节置换手术操作。传统方法组按常规全膝关节置换手术操作。术后通过 CT扫描比较两种方法定位的截骨准确性。结果 导航模板与股骨髁和胫骨平台贴合紧密,无明显移动。导航模板组 18个膝关节的股骨远端和胫骨近端截骨面与下肢机械轴垂直,2个膝关节内翻; 17个膝关节后髁截骨面与通髁轴完全平行,3个膝关节有成角。传统方法组 20个膝关节均出现下肢机械轴内外翻,其中 5个膝关节大于 5°; 20个膝关节均出现后髁截骨面与通髁轴成角,其中 10个膝关节大于 3°。结论 导航模板法的股骨远端、胫骨近端和股骨外旋截骨准确性均高于传统手术方法。 相似文献