Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 117
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Environ Sci (China) ; 113: 219-230, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34963530

RESUMO

The discharge of slaughterhouse wastewater (SWW) is increasing and its wastewater has to be treated thoroughly to avoid the eutrophication. The hybrid zeolite-based ion-exchange and sulfur autotrophic denitrification (IX-AD) process was developed to advanced treat SWW after traditional secondary biological process. Compared with traditional sulfur oxidizing denitrification (SOD), this study found that IX-AD column showed: (1) stronger ability to resist NO3- pollution load, (2) lower SO42- productivity, and (3) higher microbial diversity and richness. Liaoning zeolites addition guaranteed not only the standard discharge of NH4+-N, but also the denitrification performance and effluent TN. Especially, when the ahead secondary biological treatment process run at the ultra-high load, NO3--N removal efficiency for IX-AD column was still ~100%, whereas only 64.2% for control SOD column. The corresponding average effluent TN concentrations for IX-AD and SOD columns were 5.89 and 65.55 mg/L, respectively. Therefore, IX-AD is a promising technology for advanced SWW treatment and should be widely researched and popularized.


Assuntos
Purificação da Água , Zeolitas , Matadouros , Processos Autotróficos , Reatores Biológicos , Desnitrificação , Nitratos , Nitrogênio , Oxirredução , Enxofre , Águas Residuárias
2.
Clin Anat ; 33(2): 275-285, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31639237

RESUMO

Controversies regarding structure and function of the pelvic floor persist because of its poor accessibility and complex anatomical architecture. Most data are based on dissection. This "surgical" approach requires profound prior knowledge, because applying the scalpel precludes a "second look." The "sectional" approach does not entail these limitations, but requires segmentation of structures and three-dimensional reconstruction. This approach has produced several "Visible Human Projects." We dealt with limited spatial resolution and difficult-to-segment structures by proceeding from clear-cut to more fuzzy boundaries and comparing segmentation between investigators. We observed that the bicipital levator ani muscle consisted of pubovisceral and puborectal portions; that the pubovisceral muscle formed, together with rectococcygeal and rectoperineal muscles, a rectal diaphragm; that the external anal sphincter consisted of its subcutaneous portion and the puborectal muscle only; that the striated urethral sphincter had three parts, of which the middle (urethral compressor) was best developed in females and the circular lower ("membranous") best in males; that the rectourethral muscle, an anterior extension of the rectal longitudinal smooth muscle, developed a fibrous node in its center (perineal body); that the perineal body was much better developed in females than males, so that the rectourethral subdivision into posterior rectoperineal and anterior deep perineal muscles was more obvious in females; that the superficial transverse perineal muscle attached to the fibrous septa of the ischioanal fat; and that the uterosacral ligaments and mesorectal fascia colocalized. To facilitate comprehension of the modified topography we provide interactive 3D-PDFs that are freely available for teaching purposes. Clin. Anat. 33:275-285, 2020. © 2019 Wiley Periodicals, Inc.


Assuntos
Anatomia/educação , Imageamento Tridimensional , Modelos Anatômicos , Diafragma da Pelve/anatomia & histologia , Feminino , Humanos , Masculino
3.
Surg Radiol Anat ; 41(10): 1193-1204, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31030233

RESUMO

BACKGROUND: Medical three-dimensional (3D) digital reconstruction and printing have become common tools in medicine, but few undergraduate medical students understand its whole process and teaching and clinical application. Therefore, we designed an elective course of 3D reconstruction and printing for students and studied its significance and practicability. METHODS: Thirty undergraduate medical students in their second-year of study volunteered to participate in the course. The course started with three lessons on the theory of 3D digital reconstruction and printing in medicine. The students were then randomly divided into ten groups. Each group randomly selected its own original data set, which could contain a series of 2D images including sectional anatomical images, histological images, CT and MRI. Amira software was used to segment the structures of interest, to 3D reconstruct them and to smooth and simplify the models. These models were 3D printed and post-processed. Finally, the 3D digital and printed models were scored, and the students produced brief reports of their work and knowledge acquisition and filled out an anonymous questionnaire about their study perceptions. RESULTS: All the students finished this course. The average score of the 30 students was 83.1 ± 2.7. This course stimulated the students' learning interest and satisfied them. It was helpful for undergraduate students to understand anatomical structures and their spatial relationship more deeply. Students understood the whole process of 3D reconstruction and printing and its teaching and clinical applications through this course. CONCLUSION: It is significant and necessary to develop this course for undergraduate medical students.


Assuntos
Anatomia/educação , Educação de Graduação em Medicina/métodos , Imageamento Tridimensional , Modelos Anatômicos , Impressão Tridimensional , Conjuntos de Dados como Assunto , Avaliação Educacional , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Software , Estudantes de Medicina , Ensino , Tomografia Computadorizada por Raios X , Adulto Jovem
4.
J Anat ; 233(4): 447-459, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30051458

RESUMO

The fibro-muscular architecture of the urogenital triangle remains contentious. Reasons are small size of the constituting structures and poor visibility with most imaging methods. We reinvestigated the area in serial sections of three males (21-38 years old) of the American and Chinese Visible Human Projects and two 26-week-old male fetuses, and compared the findings with earlier observations in females. The mass of the levator ani muscle was approximately twofold smaller and its funnel shape steeper in males than females. In the levator hiatus, a strand of the smooth longitudinal muscle layer of the rectum, the 'rectourethral (RU) muscle', extended anteriorly from the anorectal bend to the penile bulb. Fibrous tissue that formed in the inferior reach of the fetal RU muscle identified the location of the developing perineal body (PB) and divided the muscle into posterior 'rectoperineal' and anterior 'deep perineal' portions. In males, the PB remained small and bipartite, so that the RU muscle presented as an undivided midline structure. The well-developed female PB, instead, intertwined with the deep perineal muscle and both structures passed the vagina bilaterally to form the perineal membrane in the posterior portion of the urogenital triangle. The urethral rhabdosphincter extended in the anterior portion of the urogenital triangle between the penile bulb inferiorly and the bladder neck superiorly, and consisted of a well-developed circular 'membranous' portion with bilateral posteroinferior 'wings' and a thinner 'prostatic' portion on the prostate anterior side. In men, muscles occupy the urogenital triangle, but additional tightening of the locally fibrous adipose tissue by the superficial transverse perineal muscle appears necessary to generate functional support in women. An interactive 3D pdf file with these anatomical details (available online) should allow more accurate interpretation of ultrasound, computed tomography and magnetic resonance images.


Assuntos
Diafragma da Pelve/anatomia & histologia , Caracteres Sexuais , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
5.
J Anat ; 233(1): 121-134, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29663370

RESUMO

In recent years, there has been increasing demand for personalized anatomy modelling for medical and industrial applications, such as ergonomics device development, clinical radiological exposure simulation, biomechanics analysis, and 3D animation character design. In this study, we constructed deformable torso phantoms that can be deformed to match the personal anatomy of Chinese male and female adults. The phantoms were created based on a training set of 79 trunk computed tomography (CT) images (41 males and 38 females) from normal Chinese subjects. Major torso organs were segmented from the CT images, and the statistical shape model (SSM) approach was used to learn the inter-subject anatomical variations. To match the personal anatomy, the phantoms were registered to individual body surface scans or medical images using the active shape model method. The constructed SSM demonstrated anatomical variations in body height, fat quantity, respiratory status, organ geometry, male muscle size, and female breast size. The masses of the deformed phantom organs were consistent with Chinese population organ mass ranges. To validate the performance of personal anatomy modelling, the phantoms were registered to the body surface scan and CT images. The registration accuracy measured from 22 test CT images showed a median Dice coefficient over 0.85, a median volume recovery coefficient (RCvlm ) between 0.85 and 1.1, and a median averaged surface distance (ASD) < 1.5 mm. We hope these phantoms can serve as computational tools for personalized anatomy modelling for the research community.


Assuntos
Povo Asiático , Tamanho Corporal , Modelos Anatômicos , Imagens de Fantasmas , Tomografia Computadorizada por Raios X/métodos , Tronco/anatomia & histologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Tamanho Corporal/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Aparência Física/fisiologia , Somatotipos/fisiologia , Tronco/fisiologia
6.
Adv Exp Med Biol ; 1093: 65-71, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30306472

RESUMO

In this chapter, we present a multi-object model-based multi-atlas segmentation constrained grid cut method for automatic segmentation of lumbar vertebrae from a given lumbar spinal CT image. More specifically, our automatic lumbar vertebrae segmentation method consists of two steps: affine atlas-target registration-based label fusion and bone-sheetness assisted multi-label grid cut which has the inherent advantage of automatic separation of the five lumbar vertebrae from each other. We evaluate our method on 21 clinical lumbar spinal CT images with the associated manual segmentation and conduct a leave-one-out study. Our method achieved an average Dice coefficient of 93.9 ± 1.0% and an average symmetric surface distance of 0.41 ± 0.08 mm.


Assuntos
Processamento de Imagem Assistida por Computador , Vértebras Lombares/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Algoritmos , Humanos
7.
J Anat ; 230(5): 651-663, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28299781

RESUMO

The pelvic floor guards the passage of the pelvic organs to the exterior. The near-epidemic prevalence of incontinence in women continues to generate interest in the functional anatomy of the pelvic floor. However, due to its complex architecture and poor accessibility, the classical 'dissectional' approach has been unable to come up with a satisfactory description, so that many aspects of its anatomy continue to raise debate. For this reason, we opted for a 'sectional' approach, using the Chinese Visible Human project (four females, 21-35 years) and the Visible Human Project (USA; one female, 59 years) datasets to investigate age-related changes in the architecture of the anterior and middle compartments of the pelvic floor. The puborectal component of the levator ani muscle defined the levator hiatus boundary. The urethral sphincter complex consisted of a circular proximal portion (urethral sphincter proper), a sling that passed on the vaginal wall laterally to attach to the puborectal muscle (urethral compressor), and a circular portion that surrounded the distal urethra and vagina (urethrovaginal sphincter). The exclusive attachment of the urethral sphincter to soft tissues implies dependence on pelvic-floor integrity for optimal function. The vagina was circular at the introitus and gradually flattened between bladder and rectum. Well-developed fibrous tissue connected the inferior vaginal wall with urethra, rectum and pelvic floor. With eight-muscle insertions, the perineal body was a strong, irregular fibrous node that guarded the levator hiatus. Only loose areolar tissue comprising a remarkably well developed venous plexus connecting the middle and superior parts of the vagina with the lateral pelvic wall. The posterolateral boundary of the putative cardinal and sacrouterine ligaments coincided with the adventitia surrounding the mesorectum. The major difference between the young-adult and postmenopausal pelvic floor was the expansion of fat in between the components of the pelvic floor. We hypothesize that accumulation of pelvic fat compromises pelvic-floor cohesion, because the pre-pubertal pelvis contains very little fibrous and adipose tissue, and fat is an excellent lubricant.


Assuntos
Envelhecimento/fisiologia , Diafragma da Pelve/anatomia & histologia , Diafragma da Pelve/fisiologia , Pós-Menopausa/fisiologia , Adulto , Feminino , Humanos , Ligamentos/anatomia & histologia , Ligamentos/fisiologia , Pessoa de Meia-Idade , Uretra/anatomia & histologia , Uretra/fisiologia , Vagina/anatomia & histologia , Vagina/fisiologia , Adulto Jovem
8.
Med Sci Monit ; 23: 2436-2444, 2017 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-28530218

RESUMO

BACKGROUND The aim of this study was to use a three-dimensional (3D) visualization technology to illustrate and describe the anatomical features of the penile suspensory ligamentous system based on the Visible Human data sets and to explore the suspensory mechanism of the penis for the further improvement of the penis-lengthening surgery. MATERIAL AND METHODS Cross-sectional images retrieved from the first Chinese Visible Human (CVH-1), third Chinese Visible Human (CVH-3), and Visible Human Male (VHM) data sets were used to segment the suspensory ligamentous system and its adjacent structures. The magnetic resonance imaging (MRI) images of this system were studied and compared with those from the Visible Human data sets. The 3D models reconstructed from the Visible Human data sets were used to provide morphological features of the penile suspensory ligamentous system and its related structures. RESULTS The fundiform ligament was a superficial, loose, fibro-fatty tissue which originated from Scarpa's fascia superiorly and continued to the scrotal septum inferiorly. The suspensory ligament and arcuate pubic ligament were dense fibrous connective tissues which started from the pubic symphysis and terminated by attaching to the tunica albuginea of the corpora cavernosa. Furthermore, the arcuate pubic ligament attached to the inferior rami of the pubis laterally. CONCLUSIONS The 3D model based on Visible Human data sets can be used to clarify the anatomical features of the suspensory ligamentous system, thereby contributing to the improvement of penis-lengthening surgery.


Assuntos
Bases de Dados como Assunto , Ligamentos/anatomia & histologia , Pênis/anatomia & histologia , Adulto , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino , Osso Púbico/anatomia & histologia , Adulto Jovem
9.
Psychiatry Clin Neurosci ; 71(4): 247-253, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27873466

RESUMO

AIM: Structural and functional magnetic resonance imaging (MRI) studies have revealed evidence of brain abnormalities in post-traumatic stress disorder (PTSD) patients. Cortical complexity and local gyrification index (lGI) reflect potential biological processes associated with normal or abnormal cognitive functioning. In the current study, lGI was used to explore cortical folding in PTSD patients involved in motor vehicle accidents (MVA). METHODS: MRI brain scans were acquired from 18 PTSD patients who had suffered MVA at least 6 months previously and 18 healthy control subjects. All MRI images were obtained on a 3-T Siemens MRI machine and the cortical folding was analyzed using the workflow provided by software FreeSurfer. A general FreeSurfer's general linear model was used in the group analysis. In addition, correlation analysis was performed between the average of lGI extracted from the significantly different areas and the data for the clinical scale. RESULTS: The PTSD patients had significantly greater Clinician-Administered PTSD Scale scores than the control group. The patients showed significantly reduced lGI in the left lateral orbitofrontal cortex, consistent with findings of previous volumetric studies on PTSD. But there were no significant correlations in the left lateral orbitofrontal cortex between Clinician-Administered PTSD Scale scores and lGI. CONCLUSION: We suggest that abnormal gyrification in PTSD patients can be an important indicator of neurodevelopment deficits and may indeed be a biological marker for PTSD.


Assuntos
Acidentes de Trânsito , Córtex Cerebral/patologia , Transtornos de Estresse Pós-Traumáticos/patologia , Adolescente , Adulto , Mapeamento Encefálico , Estudos de Casos e Controles , Endofenótipos , Feminino , Humanos , Masculino , Estatística como Assunto , Adulto Jovem
10.
Surg Radiol Anat ; 39(4): 441-449, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27663868

RESUMO

PURPOSE: Human anatomy learning confronts many difficulties, including the lack of anatomical specimens and limitations in anatomical dissection techniques that can destroy and change the shape and position of anatomic structures. A Virtual Anatomy System can help to overcome these difficulties. METHODS: Based on the high-resolution thin-sectional anatomical images of the Chinese Visible Human data set, we created a Virtual Anatomical System, including nearly all male and female anatomical structures. RESULTS: With this system, medical students can freely observe the detailed anatomical information of the coronal, sagittal, and transverse sections through a 3D-reconstructed realistic model on a personal computer in the local network. CONCLUSIONS: This Virtual Anatomy System is an easy and direct way for students to learn and understand the shape and the relationship of anatomic structures, which can also make the anatomy learning more interesting. Furthermore, it can help students synthetically master the anatomical knowledge.


Assuntos
Anatomia/educação , Educação Médica/métodos , Aprendizagem , Interface Usuário-Computador , Projetos Ser Humano Visível , China , Dissecação , Feminino , Humanos , Imageamento Tridimensional , Masculino , Modelos Anatômicos
11.
Biometals ; 27(6): 1217-30, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25106461

RESUMO

Biodegradable magnesium alloy implants have attracted much attention because of their excellent biocompatibility and good mechanical properties. However, effects of Mg alloy on cell apoptosis remain unclear. The aim of this study was to investigate the effects of the Mg-6Zn alloy on the apoptosis and necrosis of common bile duct (CBD) epithelial cells. In the in vitro experiments, primary mouse extrahepatic bile epithelial cells (MEBECs) were exposed to Mg-6Zn alloy extracts with different concentrations (0, 40, 80, and 100 %). Flow cytometry analysis indicated that low concentration Mg-6Zn extract can induce apoptosis of MEBECs, and high concentration Mg-6Zn extracts may relate to necrosis and/or 'apoptotic necrosis'. Real-time PCR results showed that when MEBECs were treated with 40 % extracts for 3 days, the relative apoptotic genes including Bax, Bax/Bcl-2 ratio, NF-κB and caspase-3 were higher than those in the control group. In the in vivo experiments, Mg-6Zn alloy stents were implanted into rabbits' CBD for 1, 2, 3 weeks, respectively. Based on the hematoxylin and eosin (H&E) staining of peri-implant CBD tissue, no apoptotic bodies and necrotic cells were observed. Results of immunohistochemical staining also showed Mg-6Zn stents did not increase expression levels of apoptosis related gene such as Bax, Bcl-2, Bax/Bcl-2 ratio, TNF-α, NF-κB and caspase-3 in CBD, which indicating Mg-6Zn did not induce significant apoptosis in the in vivo experiments. The different results of in vitro and in vivo experiment may result from the low corrosion rate of Mg-6Zn alloy stents in vivo and local Mg(2+) ion concentration in CBD.


Assuntos
Materiais Biocompatíveis/farmacologia , Ducto Colédoco/citologia , Células Epiteliais/efeitos dos fármacos , Stents , Implantes Absorvíveis , Ligas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Proteínas Reguladoras de Apoptose/biossíntese , Proteínas Reguladoras de Apoptose/genética , Ducto Colédoco/cirurgia , Citometria de Fluxo , Teste de Materiais , Camundongos , Camundongos Endogâmicos BALB C , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Coelhos , Reação em Cadeia da Polimerase em Tempo Real
12.
J Mater Sci Mater Med ; 25(2): 471-80, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24243223

RESUMO

There is a great clinical need for biodegradable bile duct stents. Biodegradable stents made of an Mg-6Zn alloy were investigated in both vivo animal experiment and in vitro cell experiments. During the in vivo experiments, blood biochemical tests were performed to determine serum magnesium, serum creatinine (CREA), blood urea nitro-gen (BUN), serum lipase (LPS), total bilirubin (TB) and glutamic-pyruvic transaminase (GPT) levels. Moreover, tissue samples of common bile duct (CBD), liver and kidney were taken for histological evaluation. In the in vitro experiments, primary mouse extrahepatic bile duct epithelial cells (MEBDECs) were isolated and cultured. Cytotoxicity testing was carried out using the MTT method. Flow cytometry analyses with propidium iodide staining were performed to evaluate the effect of Mg-6Zn alloy extracts on cell cycle. The in vivo experiments revealed no significant differences (P > 0.05) in serum magnesium, CREA, BUN, LPS, TB or GPT before and after the operation. Based on the HE results, hepatocytes, bile duct epithelial cells, renal glomerulus and renal tubule tissues did not present significant necrosis. In the in vitro experiments, the cell relative growth rate curve did not change significantly from 20 to 40 % extracts. In vitro experiments showed that 20-40 % Mg-6Zn extracts are bio-safe for MEBDECs. In vivo experiments showed that Mg-6Zn stents did not affect several important bio-chemical parameters or, harm the function or morphology of the CBD, kidney, pancreas and liver. Our data suggested that this Mg-6Zn alloy is a safe biocompatible material for CBD.


Assuntos
Ligas , Bile/química , Materiais Biocompatíveis , Magnésio/química , Zinco/química , Alanina Transaminase/sangue , Animais , Nitrogênio da Ureia Sanguínea , Células Cultivadas , Creatinina/sangue , Citometria de Fluxo , Técnicas In Vitro , Magnésio/sangue , Coelhos , Stents
13.
J Craniofac Surg ; 25(1): 303-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24336036

RESUMO

As we know, the human brain is one of the most complicated organs in the human body, which is the key and difficult point in neuroanatomy and sectional anatomy teaching. With the rapid development and extensive application of imaging technology in clinical diagnosis, doctors are facing higher and higher requirement on their anatomy knowledge. Thus, to cultivate medical students to meet the needs of medical development today and to improve their ability to read and understand radiographic images have become urgent challenges for the medical teachers. In this context, we developed a digital interactive human brain atlas based on the Chinese visible human datasets for anatomy teaching (available for free download from http://www.chinesevisiblehuman.com/down/DHBA.rar). The atlas simultaneously provides views in all 3 primary planes of section. The main structures of the human brain have been anatomically labeled in all 3 views. It is potentially useful for anatomy browsing, user self-testing, and automatic student assessment. In a word, it is interactive, 3D, user friendly, and free of charge, which can provide a new, intuitive means for anatomy teaching.


Assuntos
Encéfalo/anatomia & histologia , Neuroanatomia/educação , Materiais de Ensino , Interface Usuário-Computador , Projetos Ser Humano Visível , Anatomia Transversal/educação , Atlas como Assunto , China , Compreensão , Educação Médica , Avaliação Educacional , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Software , Estudantes de Medicina , Adulto Jovem
14.
Int J Mol Sci ; 15(2): 2959-70, 2014 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-24566138

RESUMO

A type of specially designed pin model of Mg-Zn alloy was implanted into the full thickness of lesions of New Zealand rabbits' femoral condyles. The recovery progress, outer surface healing and in vivo degradation were characterized by various methods including radiographs, Micro-CT scan with surface rendering, SEM (scanning electron microscope) with EDX (Energy Dispersive X-ray analysis) and so on. The in vivo results suggested that a few but not sufficient bridges for holding force were formed between the bone and the implant if there was a preexisting gap between them. The rapid degradation of the implantation in the condyle would result in the appearance of cavities. Morphological evaluation of the specially designed pins indicated that the cusp was the most vulnerable part during degradation. Furthermore, different implantation sites with distinct components and biological functions can lead to different degradation rates of Mg-Zn alloy. The rate of Mg-Zn alloy decreases in the following order: implantation into soft tissue, less trabecular bone, more trabecular bone, and cortical bone. Because of the complexities of in vivo degradation, it is necessary for the design of biomedical Mg-Zn devices to take into consideration the implantation sites used in clinics.


Assuntos
Ligas/metabolismo , Pinos Ortopédicos , Fêmur/diagnóstico por imagem , Ligas/química , Animais , Fêmur/patologia , Magnésio/química , Teste de Materiais , Coelhos , Fatores de Tempo , Tomografia Computadorizada por Raios X , Zinco/química
15.
Plant Cell ; 22(7): 2402-16, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20605854

RESUMO

The mechanisms that regulate mitochondrial inheritance are not yet clear, even though it is 100 years since the first description of non-Mendelian genetics. Here, we quantified the copy numbers of mitochondrial DNA (mtDNA) in the gametic cells of angiosperm species. We demonstrate that each egg cell from Arabidopsis thaliana, Antirrhinum majus, and Nicotiana tabacum possesses 59.0, 42.7, and 73.0 copies of mtDNA on average, respectively. These values are equivalent to those in Arabidopsis mesophyll cells, at 61.7 copies per cell. On the other hand, sperm or generative cells from Arabidopsis, A. majus, and N. tabacum possess minor amounts of mtDNA, at 0.083, 0.47, and 1 copy on average, respectively. We further reveal a 50-fold degradation of mtDNA during pollen development in A. majus. In contrast, markedly high levels of mtDNA are found in the male gametic cells of Cucumis melo and Pelargonium zonale (1296.3 and 256.7 copies, respectively). Our results provide direct evidence for mitochondrial genomic insufficiency in the eggs and somatic cells and indicate that a male gamete of an angiosperm may possess mtDNA at concentrations as high as 21-fold (C. melo) or as low as 0.1% (Arabidopsis) of the levels in somatic cells. These observations reveal the existence of a strong regulatory system for the male gametic mtDNA levels in angiosperms with regard to mitochondrial inheritance.


Assuntos
DNA Mitocondrial/genética , Magnoliopsida/genética , Pólen , Dados de Sequência Molecular
16.
J Mater Sci Mater Med ; 24(6): 1515-25, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23512150

RESUMO

To evaluate the ability of Mg-6Zn to replace titanium nails in the reconstruction of the intestinal tract in general surgery, we compared the Mg-6Zn and titanium implants with respect to their effects on rat's intestinal tract by biochemical, radiological, pathological and immunohistochemical methods. The results indicated that Mg-6Zn implants started to degrade at the third week and disintegrate at the fourth week. No bubbles appeared, which may be associated with intestinal absorption of the Mg-6Zn implants. Pathological analyses (containing liver, kidney and cecum tissues) and biochemical measurements, including serum magnesium, creatinine, blood urea nitrogen, glutamic-pyruvic-transaminase and glutamic-oxaloacetic-transaminase proved that degradation of Mg-6Zn did not harm the important organs, which is an improvement over titanium implants. Immunohistochemical results showed that Mg-6Zn could enhance the expression of transforming growth factor-ß1. Mg-6Zn reduced the expression of tumor necrosis factor at different stages. In general, our study demonstrates that the Mg-6Zn alloy had good biocompatibility in vivo and performed better than titanium at promoting healing and reducing inflammation. It may be a promising candidate for stapler pins in intestinal reconstruction.


Assuntos
Ceco/cirurgia , Magnésio/efeitos adversos , Suturas/efeitos adversos , Titânio/efeitos adversos , Tiflite/etiologia , Tiflite/prevenção & controle , Zinco/efeitos adversos , Ligas/efeitos adversos , Ligas/química , Animais , Materiais Biocompatíveis/efeitos adversos , Materiais Biocompatíveis/química , Magnésio/química , Masculino , Teste de Materiais , Ratos , Ratos Sprague-Dawley , Tiflite/patologia , Zinco/química
17.
J Shoulder Elbow Surg ; 21(9): 1207-12, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22047784

RESUMO

BACKGROUND: Although the incidence of osteoarticular tuberculosis is increasing, glenohumeral joint tuberculosis is rare and often misdiagnosed in its early stages. Our objective was to study the incidence of the initial misdiagnosis as frozen shoulder and the duration of the prediagnostic period among patients with glenohumeral joint tuberculosis. METHODS: The clinical records of 21 patients with tuberculosis of the shoulder joint were retrospectively analyzed. RESULTS: Among the 16 patients with glenohumeral joint tuberculosis, 14 (87.5%) were initially diagnosed as having frozen shoulder instead of glenohumeral joint tuberculosis at their primary care clinics. Two patients actually showed both shoulder pain and limited range of motion, although they did not have a record of initial diagnosis with frozen shoulder. Consequently, 14 (87.5%) of the patients in our study with glenohumeral joint tuberculosis were likely misdiagnosed as having frozen shoulder. On the other hand, this group accounted for 3.6% (n = 16) of 450 patients who, during the same period, had been initially diagnosed with frozen shoulder at our institution. The mean prediagnostic period to attain the final, correct diagnosis of glenohumeral joint tuberculosis for this group was 14.5 months. CONCLUSION: It appears that misdiagnosis is common and early diagnosis of tubercular infection in the glenohumeral joint has become increasingly difficult. Glenohumeral joint tuberculosis should be suspected in cases of longstanding pain in the shoulder. It is necessary to re-examine these frozen shoulder patients with repeated plain radiographs followed by further imaging studies, especially magnetic resonance imaging, if conservative therapy fails.


Assuntos
Bursite/diagnóstico , Articulação do Ombro , Tuberculose Osteoarticular/diagnóstico , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
18.
Clin Anat ; 25(8): 1051-61, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22334507

RESUMO

The structures of superior mediastinum and their spatial relationships are complex and difficult to master. This study aimed to compare visualization of the superior mediastinum based on computed tomography (CT) images and on the thin sections of the Chinese visible human (CVH) data set to provide a sectional anatomical basis for diagnostic imaging of superior mediastinal pathology. CVH sections of the mediastinum of a 35-year old male were compared with plain and enhanced CT images of a 45-year old male without apparent abnormalities in the upper chest. In addition, a three-dimensional model based on the CVH sections was compared with a model based on CT images. Although CT imaging is noninvasive and can be carried out in many individuals, its weakness is clearly the visualization of small soft tissue structures. In this respect, the sectional anatomical approach of the CVH images is complementary, as it visualizes these small soft tissue structures due to the higher resolution in the plain of sectioning and the color of the different structures in the section. Three-dimensional surface and volume rendering of reconstructions of the CVH data set can help medical students and less experienced thoracic surgeons to familiarize themselves with the topographic anatomy of the superior mediastinal structures and their spatial relationships, and thus with interpreting CT images of patients.


Assuntos
Povo Asiático , Mediastino/anatomia & histologia , Mediastino/diagnóstico por imagem , Tomografia Computadorizada Espiral , Projetos Ser Humano Visível , Adulto , Cadáver , China , Diagnóstico por Imagem/métodos , Humanos , Masculino , Doenças do Mediastino/diagnóstico , Neoplasias do Mediastino/diagnóstico , Pessoa de Meia-Idade
19.
J Biomater Appl ; 36(9): 1540-1549, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35114835

RESUMO

There is a great clinical need for biodegradable materials. This study aimed to investigate the effects of Mg-6Zn and titanium alloy stapler nails on intestinal anastomosis healing mediated via the TGF-ß/Smad signaling pathway, as reflected in collagen metabolism in rabbits. Side-to-side ileo-ileostomy was performed with linear stapler loaded with the two nails. The results showed that no obvious postoperative complications such as abdominal infection and anastomotic leakage were observed. General observation and scanning electron microscope showed that Mg-6Zn alloy nails remained intact in the first week, degraded significantly in the second week, and were little left in the third week, while the titanium alloy nails showed intact substrate throughout the experimental period. Immunohistochemical analysis showed that the expression of TGF-ß1 in Mg-6Zn alloy group was higher than that in titanium alloy group after 1 week, but it increased slowly, arrived at a lower level in the third week. Collagen I showed an increased expression in Mg-6Zn alloy group, but decreased with time in titanium alloy group. An enhanced expression of collagen III in Mg-6Zn alloy group in the first week but much lower in the third week as compared to the titanium alloy group. The expression of smad2 in Mg-6Zn alloy group maintained a steady level, while in titanium alloy group it showed a general upward trend. The expression of smad3 in both groups held steady after 2 weeks, then in the third week, it showed a strong uptrend in Mg-6Zn alloy group, while decreased immediately in titanium alloy group. Our findings suggest that Mg-6Zn alloy nails degraded significantly within 3 weeks and could provide stability of intestinal anastomosis in the reconstruction of intestinal tract. TGF-ß/Smad signaling pathway may play a role in regulation of baseline collagen synthesis throughout the process.


Assuntos
Ligas , Titânio , Anastomose Cirúrgica , Animais , Colágeno , Coelhos , Transdução de Sinais , Fator de Crescimento Transformador beta1
20.
J Neurooncol ; 105(1): 67-75, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21523487

RESUMO

Accumulating evidence suggests that endothelial progenitor cells (EPCs) play a key role in the development and infiltration of gliomas. Thus, it has been considered that EPCs may be good vehicles for delivering anti-angiogenesis genes for tumor therapy. However, limited means of tracking these cells in vivo has restricted the effective evaluation of the curative effects of genetically modified EPCs in gliomas at different stages. The aim of this study was to develop a non-invasive method to monitor the migration of EPCs to gliomas using 1.5-T MR scanning. We successfully labeled EPCs isolated from cord blood with Resovist-PLL without any influence on the biological properties of these cells. After intravenous administration into glioma-bearing nude mice, the labeled EPCs specifically homed to gliomas and could be reliably tracked by 1.5-T MR as early as 1 day after transplantation, causing a signal loss on T2-weighted images. The dark area was detected throughout the entire tumor zone on day 5, and did not develop a ring as previously described. Histological analysis showed the labeled cells were mainly located at the periphery of the tumor where abundant neo-vessels were identified using CD34 staining; this finding indicates that the transplanted cells may be able to differentiate into ECs and become incorporated into glioma neovasculature. These results suggested that Resovist labeling of EPCs is feasible, efficient and safe for MRI tracking, and 1.5-T MR could be a powerful method for in vivo monitoring of EPCs as an anti-angiogenic drug therapy vector targets against glioma.


Assuntos
Dextranos , Endotélio Vascular/citologia , Glioma/irrigação sanguínea , Glioma/patologia , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita , Neovascularização Patológica/patologia , Células-Tronco/citologia , Animais , Antígenos CD34/metabolismo , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Diferenciação Celular , Movimento Celular , Proliferação de Células , Células Cultivadas , Meios de Contraste , Endotélio Vascular/transplante , Feminino , Sangue Fetal/citologia , Glioma/metabolismo , Humanos , Camundongos , Camundongos Nus , Transplante Heterólogo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA