首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The surgical management of tetralogy of Fallot has undergone important changes in recent years. Earlier repair of tetralogy of Fallot is now favored by many institutions. At Stanford University Medical Center, we have performed definitive repair of tetralogy of Fallot at the time of presentation, regardless of the child's age, with few exceptions. In this report, we describe our results with early repair, and we believe these support the contention that infants who undergo early repair (< 1 year of age) have postoperative results similar to those of children who undergo repair at an older age. Complications related to shunts are prevented by the infant repairs, and, in the future, reduced ventricular ectopy may be demonstrated to be a benefit of such repairs.  相似文献   

2.
To analyze genomic changes resulting from double-strand break (DSB) repair, transgenic tobacco plants were obtained that carried in their genome a restriction site of the rare cutting endonuclease I-SceI within a negative selectable marker gene. After induction of DSB repair via Agrobacterium-mediated transient expression of I-SceI, plant cells were selected that carried a loss-of-function phenotype of the marker. Surprisingly, in addition to deletions, in a number of cases repair was associated with the insertion of unique and repetitive genomic sequences into the break. Thus, DSB repair offers a mechanism for spreading different kinds of sequences into new chromosomal positions. This may have evolutionary consequences particularly for plants, as genomic alterations occurring in meristem cells can be transferred to the next generation. Moreover, transfer DNA (T-DNA), carrying the open reading frame of I-SceI, was found in several cases to be integrated into the transgenic I-SceI site. This indicates that DSB repair also represents a pathway for the integration of T-DNA into the plant genome.  相似文献   

3.
4.
Bone repair by regeneration as we know it continues to undergo changes, with advances approaching that may change our treatment of patients with craniofacial deformities and skeletal defects. Perhaps by the turn of the century, patients born with asymmetric deformities due to lack of growth will be treated early in life by skeletal stretching, and then later in life by skeletal distraction that is followed by use of accelerating factors to assist the healing processes. All of these available modalities are part of the regeneration of new bone formation. The future of such changes is very interesting, and our ability to help our patients will be maximized. We may even look back 25 years from now at bone grafting and find it to be obsolete and crude. It is hoped that with the new modalities being developed, we will not deviate from the use of a bone grafting procedure, which is the workhorse of the craniofacial surgeon. Bone grafting is used by all surgeons working on the craniofacial skeleton despite the problems of unpredictability of healing and an inability to calculate what percentage of the original graft will survive. The transplantation issue will be solved. The problems with donor site morbidity will continue. The use of inorganic bone substitutes will continue to have its limitation, particularly in type II wounds, which we as plastic surgeons see in the craniofacial region. As we redefine our approach to skeletal repair, we may look back and find solutions to some of the major problems we have had. The rapid stretch of soft tissue after facial advancement or structural alteration that is accompanied by a relapse due to the elastic recoil of the soft tissue could be eliminated by gradual distraction. The bone will undergo better functional adaptation when it has a gradual change in structure based on adjustment and molding in a gradual fashion. The problem of donor site morbidity and a prediction formula for bone could be resolved with new bone formation in situ by mineralization of the area under repair. Bone healing enhancers are here to stay and their clinical application will produce a far-reaching better final outcome (Fig. 11).  相似文献   

5.
Meiotic recombination in yeast is associated with heteroduplex formation. Heteroduplexes formed between nonidentical DNA strands contain DNA mismatches, and most DNA mismatches in wild-type strains are efficiently corrected. Although some patterns of mismatch correction result in non-Mendelian segregation of the heterozygous marker (gene conversion), one predicted pattern of correction (restoration-type repair) results in normal Mendelian segregation. Using a yeast strain in which a marker leading to a well-repaired mismatch is flanked by markers that lead to poorly repaired mismatches, we present direct evidence for restoration-type repair in yeast. In addition, we find that the frequency of tetrads with conversion-type repair is higher for a marker at the 5' end of the HIS4 gene than for a marker in the middle of the gene. These results suggest that the ratio of conversion-type to restoration-type repair may be important in generating gradients of gene conversion (polarity gradients).  相似文献   

6.
Evaluations of 67 adults with 90 complete digital nerve injuries were made more than 1 year after surgery. Moving and static two-point discrimination was determined on both lateral aspects of the injured and contralateral uninjured digits. Digits with primary repairs in mild crush or saw injuries had significantly worse two-point discrimination compared with digits that had a primary repair of a simple laceration. Furthermore, in mild crush injuries, digits with primary grafting had significantly better results than those with primary repair. Patients under 40 years of age had better two-point discrimination than those over 40. Some overlap innervation from the uninjured side was noted in two of eight digits tested, since sensation of the injured side was completely lost when the uninjured nerve of that digit was anesthetized. These results support the hypothesis that better recovery is obtained if tension is avoided at the nerve repair site in mild crush or saw injuries.  相似文献   

7.
Most of the attempts and efforts in cleft lip repair have been directed toward the skin incision. The importance of the orbicularis oris muscle repair has been emphasized in recent years. The well-designed skin incision with simple repair of the orbicularis oris muscle has produced a considerable improvement in the appearance of the upper lip; however, the repaired upper lip seems to change its shape abnormally in motion and has a tendency to be distorted with age if the orbicularis oris muscle is not repaired precisely and accurately. Following the dissection of the normal upper lip and unilateral cleft lip in cadavers, we could find two different components in the orbicularis oris muscle, a superficial and a deep component. One is a retractor and the other is a constrictor of the lip. They have antagonistic actions to each other during lip movement. We also can identify these two different components of the muscle in the cleft lip patient during operation. We thought inaccurate and mixed connection between these two different functional components could make the repaired lip distorted and unbalanced, which would get worse during growth. By identification and separate repair of the two different muscular components of the orbicularis oris muscle (i.e., repair of the superficial and deep components on the lateral side with the corresponding components on the medial side), better results in the dynamic and three-dimensional configuration of the upper lip can be achieved, and unfavorable distortion can be avoided as the patients grow.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

8.
A randomized controlled trial in women with neuropathic faecal incontinence compared total pelvic floor repair (n = 12) with anterior levatorplasty and sphincter plication alone (n = 12) and postanal repair alone (n = 12). Review at 6 and 24 months indicated that results were significantly better for total pelvic floor repair than either of the other procedures. Complete continence was achieved in eight of the 12 patients 2 years after total pelvic floor repair. Only total repair significantly elongated the anal canal. Both total pelvic floor repair and anterior levatorplasty improved sensation in the upper anal canal.  相似文献   

9.
Achilles tendon suture combined with a triceps surae tendon tip-over graft was performed in 314 patients with acute rupture of the Achilles tendon between 1980 and 1991. Analysis of these cases showed a low tissue complication rate compared with that reported in the literature. An average of 8.1 years after repair, 223 patients were examined using Holz's scale of clinical assessment after Achilles tendon repair. The results were 'good' in 87.4%, 'fair' in 11.2% and 'poor' in 1.4%. The re-rupture rate was very low (0.4%). These results are better than the re-rupture rate after surgical repair with solely end-to-end suture or after conservative immobilizing or conservative functional treatment. In conclusion, these data show that the fascial reinforcement is a valuable complement to the tendon suture.  相似文献   

10.
Because our training models in Clinical Psychology have not kept pace with the rapid changes in the health care marketplace, we may be in danger of preparing psychologists for markets that no longer exist. The next generations of psychologists will require the skills of the entrepreneur and the leader in addition to a range of core clinical skills. At the same time, our profession's historic commitment to science as the best epistemic game in town may founder if we fail to pay better attention to knowledge translation (i.e., how to move scientific findings expeditiously from the laboratory into practice). (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

11.
Recent research suggests that marital quality predicts the survival of patients with heart failure (HF), and it is hypothesized that a communal orientation to coping marked by first-person plural pronoun use (we talk) may be a factor in this. During a home interview, 57 HF patients (46 men and 16 women) and their spouses discussed how they coped with the patients' health problems. Analysis of pronoun counts from both partners revealed that we talk by the spouse, but not the patient, independently predicted positive change in the patient's HF symptoms and general health over the next 6 months and did so better than direct self-report measures of marital quality and the communal coping construct. We talk by the patient and spouse did not correlate, however, and gender had no apparent moderating effects on how pronoun use predicted health change. The results highlight the utility of automatic text analysis in couple-interaction research and provide further evidence that looking beyond the patient can improve prediction of health outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

12.
We demonstrated recently that dominant negative mutants of rat DNA polymerase beta (Pol beta) interfere with repair of alkylation damage in Saccharomyces cerevisiae. To identify the alkylation repair pathway that is disrupted by the Pol beta dominant negative mutants, we studied the epistatic relationship of the dominant negative Pol beta mutants to genes known to be involved in repair of DNA alkylation damage in S. cerevisiae. We demonstrate that the rat Pol beta mutants interfere with the base excision repair pathway in S. cerevisiae. In addition, expression of one of the Pol beta dominant negative mutants, Pol beta-14, increases the spontaneous mutation rate of S. cerevisiae whereas expression of another Pol beta dominant negative mutant, Pol beta-TR, does not. Expression of the Pol beta-14 mutant in cells lacking APN1 activity does not result in an increase in the spontaneous mutation rate. These results suggest that gaps are required for mutagenesis to occur in the presence of Pol beta-14 but that it is not merely the presence of a gap that results in mutagenesis. Our results suggest that mutagenesis can occur during the gap-filling step of base excision repair in vivo.  相似文献   

13.
GPRVS is a properitoneal hernioplasty with a prosthesis composed of the polyester Dacron. The repair is anatomic, sutureless, tension-free, and the absolute weapon to eliminate all types of groin hernias. No other technique produces better results for the repair of recurrent and re-recurrent groin hernias. It also is a joy to perform.  相似文献   

14.
Vacuum bagging and pressure bagging are established techniques used by the composites industry for fabricating components. This paper describes a study that explored the adaptation of these techniques for improving the FRP-concrete bond in the repair of partially submerged piles. Prototype vacuum bagging and pressure bagging systems were developed and bond improvement assessed from results of pullout tests on full size piles repaired under simulated tide in the laboratory. Pressure bagging gave better bond and was found to be simpler because it did not require an airtight seal. A field demonstration project was conducted in which pressure bagging was used in combination with two different GFRP systems to repair two corroding piles supporting the Friendship Trails Bridge across Tampa Bay. Inspection of the postcured wrap showed no evidence of air voids. The study demonstrates that techniques developed by the composites industry may be readily adapted to provide effective and inexpensive means for improving FRP-concrete bond.  相似文献   

15.
An alternative approach for correction of supracardiac (type I) total anomalous pulmonary venous return is described. A median sternotomy is used. The posterior wall of the left atrium and the common pulmonary venous trunk are exposed through the transverse sinus. A direct anastomosis between these structures, ligation of the systemic-venous connection (vertical vein), and closure of the interatrial septal defect results in a one-stage repair. In our experience with the supracardiac anomaly in 20 patients, we have found that this approach consistently affords better exposure than other techniques currently in use for surgical correction of this anomaly.  相似文献   

16.
Photochemical thrombotic ischemia model was used to study the possible roles of excision repair cross-complementing group 6 (ERCC6), a DNA repair gene, in the neuroprotection of dextromethorphan (DM), a NMDA antagonist, in ischemic brain injury. The results showed that no obvious ERCC6 mRNA expression was found in the perifocal area of irradiated cerebral cortex before 24 h postischemia. Then, the number of ERCC6 mRNA positive cells gradually enhanced, and attained a peak value at 72 h after light irradiation, which followed a declined tendency at 7-day postlesion. These results suggest that DNA repair gene ERCC6 mRNA expression in the perifocal area may be involved in the pathophysiological processes following the photochemical thrombotic cerebral ischemia. By the administration of DM, we observed that it can significantly upregulate the expression of ERCC6 mRNA in the perifocal area at 48 h after ischemic event. The neuroprotective mechanisms of DM may be related to the upregulation of DNA repair gene ERCC6 mRNA.  相似文献   

17.
Many steel bridges built prior to 1960 have bridge deck connections that are subject to high cycle fatigue. These connections may be nearing their fatigue limit and will require increased inspection and repair over the next 10–20 years. The Winchester Bridge on Interstate 5 in Roseburg, Ore., required the extensive replacement of connection details because of fatigue crack growth. This report describes the results of a study to assess the loading conditions for the connection details on the Winchester Bridge. Finite-element modeling methods were used to characterize the structure, on both a global and local level. The global model provided the boundary conditions for the local model of the connection details. The local model included the effects of rivet preload and friction. Finite-element analysis results were validated by hand calculation. The analysis showed significant variation in connection detail stress range, depending on the detail’s longitudinal and lateral location.  相似文献   

18.
This research examined the hypothesis that people with low self-esteem (LSE) are less motivated than people with high self-esteem (HSE) to repair their negative moods. In Study 1, participants completed diaries in response to either a success or a failure in their everyday lives. Participants described what they intended to do next and the reasons behind those plans. After failure, fewer LSE than HSE participants expressed a goal to improve their mood. A follow-up investigation (Study 2) suggested that this difference was not due to a self-esteem difference in knowledge of mood repair strategies. In Study 3, after undergoing a negative mood induction, fewer LSE than HSE participants chose to watch a comedy video, even though both groups believed the comedy video would make them happy. Studies 4 and 5 explored possible reasons why LSE people are less motivated than HSE people to repair their negative moods. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

19.
Professionals in the construction industry must be able to accurately forecast costs. Doing so not only helps assure reasonable profits for companies, but it can also help ensure that projects are delivered within budget for clients. Forecasting of equipment repair costs is one element of the larger problem of predicting overall costs. The cumulative cost model can provide construction engineers with a valuable tool for better understanding the nature of repair costs as they relate to production fleets. Data that are being collected (or that could be collected) can assist in the determination of the rate of accumulation of repair costs for a machine for a given period of use or the estimation of fleet repair budgets for a job or period. There are two different methodologies for constructing the repair cost portion of the cumulative cost model: life-to-date (LTD) repair costs and the period-cost-based (PCB) model. This paper will provide the steps and background for each of these two methodologies and compare them using a practical example.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号