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21.
Qiang Tan Rudolf Steiner Simon P Hoerstrup Walter Weder 《European journal of cardio-thoracic surgery》2006,30(5):782-786
This review tries to summarize the efforts over the past 20 years to construct a tissue-engineered trachea. After illustrating the main technical bottlenecks faced nowadays, we discuss what might be the solutions to these bottlenecks. You may find out why the focus in this research field shifts dramatically from the construction of a tubular cartilage tissue to reepithelialization and revascularization of the prosthesis. In the end we propose a novel concept of 'in vivo bioreactor', defined as the design of a perfusion system inside the scaffold, and explain its potential application in the construction of a tissue-engineered trachea. 相似文献
22.
23.
Francisco J. Romero Juan Segura-Aguilar Elena Monsalve Carlos Hermenegildo Eberhard Nies Francisco J. Puertas Joaquí n Rom 《Neurotoxicology and teratology》1990,12(6):603-605
The present work tries to establish the antioxidant capacity of the peripheral nervous tissue of the rat, in terms of the enzymatic activities present in this tissue that either prevent the formation of activated species as the semiquinone radical (DT-diaphorase), protect against activated oxygen species (superoxide dismutase, glutathione peroxidase), conjugate natural toxic products or xenobiotics (glutathione S-transferases, especially the activity conjugating 4-hydroxy-nonenal), or complete the glutathione system metabolism (glutathione disulfide reductase, γ-glutamyl transpeptidase). All the activities studied are lower in this tissue than they are in liver, except for γ-glutamyl transpeptidase. The relevance of the results obtained and its possible relationship with different neuropathies is discussed. It is concluded that the peripheral nervous tissue is by far less protected than the liver against oxidative damage. 相似文献
24.
25.
Lack of islet amyloid polypeptide regulation of insulin biosynthesis or secretion in normal rat islets 总被引:4,自引:0,他引:4
We examined the effects of rat islet amyloid polypeptide (IAPP) on insulin biosynthesis and secretion by isolated rat islets of Langerhans. Culture of islets for 24 h in the presence of 10(-6) M IAPP and 5.5 mM glucose had no effect on insulin mRNA levels. Similarly, the rates of proinsulin biosynthesis were not altered in islets incubated in 10(-4)-10(-9) M IAPP and 5.5 mM glucose, nor was the rate of conversion of proinsulin to insulin changed at 10(-6) M IAPP. Addition of 10(-5) M IAPP to islets incubated in 11 mM glucose decreased the fractional insulin secretion rate; however, the secretion of newly synthesized proinsulin and insulin was not affected. These data indicate that it is unlikely that IAPP is a physiologically relevant modulator of insulin biosynthesis or secretion. 相似文献
26.
27.
Career Satisfaction and Clinician-Educators: The Rewards and Challenges of Teaching 总被引:1,自引:1,他引:0
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28.
Rachel Yehuda Ann Steiner Boaz Kahana Karen Binder-Brynes Steven M. Southwick Shelly Zemelman Earl L. Giller 《Journal of traumatic stress》1997,10(1):93-100
Alexithymia was measured in non-treatment seeking, community-dwelling Holocaust survivors using the Toronto Alexithymia Scale—Twenty Item Version (TAS-20). Scores of survivors with (n = 30) and without (n = 26) posttraumatic stress disorder (PTSD) were compared, and associations among alexithymia, severity of trauma, and severity of PTSD symptoms were determined. Survivors with PTSD had significantly higher scores on the TAS-20 compared to survivors without PTSD. TAS-20 scores were significantly associated with severity of PTSD symptoms, but not with severity of trauma. This study adds to our knowledge of the relationship between alexithymia and trauma by demonstrating that this characteristic is related to the presence of posttraumatic symptoms and not simply exposure to trauma. 相似文献
29.
30.
M. Kneissel P. Roschger W. Steiner D. Schamall G. Kalchhauser A. Boyde M. Teschler-Nicola 《Calcified tissue international》1997,61(2):95-100
There is abundant data on cancellous bone in the aging human spine, but little relating to the growing vertebral cancellous
bone in childhood and adolescence. The purpose of this study was to map vertebral cancellous bone in a growth and age series
of historic skeletal samples and to make comparisons with data published on recent material. Lumbar vertebral bodies were
collected from 65 skeletons (0–60 years) from a medieval Nubian population. Ethnohistoric information was collected to interpret
conditions that might have influenced bone structure and metabolism. The cancellous bone was studied three dimensionally,
using stereophotography and scanning electron microscopy and morphometrically by performing a semiautomatic structural analysis
on digitized backscattered electron images of polymethacrylate-embedded material. The cancellous bone structure in the children
consisted mainly of a densely packed, uniform network of small rodlike trabeculae. The greatest bone volume fraction with
small, more platelike trabeculae was observed during adolescence. In young adults, larger platelike trabeculae were present
in the central zone and smaller trabeculae in the superior and inferior zones, as described for modern skeletal material.
Structural changes associated with aging were observed much sooner than in modern man. By the estimated age of approximately
50–60 years, the predominant architectural elements were slender rarified rods in both sexes. The ethnohistorical data suggest
that this was essentially a black African population of physically active peasants, not likely to suffer Vitamin D insufficiency
or deficient calcium intake. Thus an earlier onset of the biological age changes in cancellous bone found in modern populations
was probably prevalent.
Received: 1 March 1996 / Accepted: 31 December 1996 相似文献