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1.
Oral submucous fibrosis is a collagen disorder affecting the submucosal layer and often severely limiting mouth opening. Previous surgical treatments have been disappointing. This article introduces a new surgical approach: reconstructing the bilateral buccal mucosa with two small radial forearm flaps. The surgical method includes the complete surgical release of fibrotic buccal mucosa and, if necessary, a bilateral coronoidectomy and temporalis muscle myotomy. From 1997 to 1999, 15 patients with moderate-to-severe trismus received reconstructive surgery, for a total of 30 small radial forearm flaps after surgical release. The flap size was between 1.5 x 5 and 2.5 x 7 cm. All donor sites were directly closed, and all flaps survived completely, except for one with partial necrosis. Six flaps required minor revisions because of size redundancy. Two patients developed buccal cancer in the area of reconstruction. At an average of 12 months' follow-up, the inter-incisal distance averaged 33 mm, an increase of 17 mm compared with the preoperative value. The donor-site morbidity was minimal, except in one heavy smoker who developed dry gangrene of his fingertips. The use of two small free forearm flaps for buccal mucosa reconstruction allows more radical release of fibrotic tissue. Coronoidectomy and temporal muscle myotomy further contribute to the effect of trismus release. The combined effects of this approach have consistently given good results. An aggressive approach toward surgical treatment of this precancerous lesion also facilitates the detection of cancer at an early stage.  相似文献   

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A profusion of terms are currently used to describe free flap wound closure. It is important to broadly standardize nomenclature when embarking on a comparison of functional outcomes between institutions. Therefore, a series of 68 "emergency" (within 24 hours) free flaps performed by a single surgeon were reviewed with respect to a total experience of 188 free tissue transfers to formulate a consistent nomenclature applicable to free flap wound closure in general. The nomenclature presented divides free flap closure into three categories: "primary free flap closure" (12 to 24 hours), "delayed primary free flap closure" (2 to 7 days), and "secondary free flap closure" (after 7 days). This system is analogous to the standard terms "primary," "delayed primary," and "secondary wound closure." It is consistent with known biologic and microbiologic principles of wound closure in general and should provide a simple basis for classifying free flap wound closure. Illustrative examples are presented to highlight the classification scheme.  相似文献   

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Malate valves act as powerful systems for balancing the ATP/NAD(P)H ratio required in various subcellular compartments in plant cells. As components of malate valves, isoforms of malate dehydrogenases (MDHs) and dicarboxylate translocators catalyse the reversible interconversion of malate and oxaloacetate and their transport. Depending on the co‐enzyme specificity of the MDH isoforms, either NADH or NADPH can be transported indirectly. Arabidopsis thaliana possesses nine genes encoding MDH isoenzymes. Activities of NAD‐dependent MDHs have been detected in mitochondria, peroxisomes, cytosol and plastids. In addition, chloroplasts possess a NADP‐dependent MDH isoform. The NADP‐MDH as part of the ‘light malate valve’ plays an important role as a poising mechanism to adjust the ATP/NADPH ratio in the stroma. Its activity is strictly regulated by post‐translational redox‐modification mediated via the ferredoxin‐thioredoxin system and fine control via the NADP+/NADP(H) ratio, thereby maintaining redox homeostasis under changing conditions. In contrast, the plastid NAD‐MDH (‘dark malate valve’) is constitutively active and its lack leads to failure in early embryo development. While redox regulation of the main cytosolic MDH isoform has been shown, knowledge about regulation of the other two cytosolic MDHs as well as NAD‐MDH isoforms from peroxisomes and mitochondria is still lacking. Knockout mutants lacking the isoforms from chloroplasts, mitochondria and peroxisomes have been characterised, but not much is known about cytosolic NAD‐MDH isoforms and their role in planta. This review updates the current knowledge on MDH isoforms and the shuttle systems for intercompartmental dicarboxylate exchange, focusing on the various metabolic functions of these valves.  相似文献   

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The purpose of this study was to evaluate the vascular anatomy of the paraspinous muscles and review their clinical use as bipedicled flaps in spinal wound closure. Anatomically, through cadaver dissections, lead oxide injections, and radiographic imaging, the blood supply to the paraspinous muscles was determined. Clinically, 29 consecutive patients treated with spinal wounds and exposed bone or hardware were reviewed retrospectively. Of these patients, 19 underwent closure in delayed primary fashion, whereas 10 were referred to plastic surgery for reconstruction because of the complex nature of their wounds. The cadaver study demonstrated the paraspinous muscles to possess a segmental arterial supply through medial and lateral perforators. Division of the medial perforators allowed for medial advancement of the muscles. Lead oxide injection of the lateral perforators demonstrated adequate medial muscle perfusion with ligation of the medial perforators. Ten of the 29 patients (six women, four men, 32 to 62 years of age) were reconstructed with paraspinous (eight), latissimus (one), and trapezius (one) muscle flaps. A higher complication rate was found in wounds closed in delayed primary fashion (13 of 19 patients, 68 percent) than those reconstructed with muscle flaps (2 of 10 patients, 20 percent) (p = 0.021). Follow-up of the muscle flap reconstructed patients averaged 12 months (range, 3 to 27 months). Cadaver muscle injections predicted and clinical cases confirmed that the paraspinous muscles can be raised on lateral perforators and advanced medially to close lumbar spine wounds reliably with fewer complications.  相似文献   

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Agroecosystems consist on complex trophic relationships among host plants, herbivores and their natural enemies. This article reviews the research of plant volatiles in Brazil, in order to determine multiple resistance mechanisms of economically important crops and to contribute to the understanding of insect-plant interactions. Most pest management programs, including chemical and biological control, do not consider the impact of these chemicals on herbivores and their natural enemies. Alternative control methods are being developed in order to improve our understanding on the endogenous mechanisms of plant induced defenses against phytophagous arthropods. The use of plant volatiles technology as an additional tool in integrated pest management programs would offer a new and environmentally sound approach to crop protection. This technique involves the development of baits that attract beneficial organisms and the manipulation of biochemical processes that induce and regulate plant defenses, key factors in the improvement of control programs against economically important pests. The elucidation of the mechanisms involved in the indirect defenses of plants will result in useful tools for biological control of crop pests.  相似文献   

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Reactive oxygen species (ROS)-induced damage on host cells and molecules has been considered the most likely proximal mechanism responsible for the age-related decline in organismal performance. Organisms have two possible ways to reduce the negative effect of ROS: disposing of effective antioxidant defenses and minimizing ROS production. The unbalance between the amount of ROS produced and the availability of antioxidant defenses determines the intensity of so-called oxidative stress. Interestingly, most studies that deal with the effect of oxidative stress on organismal performance have focused on the antioxidant defense compartment and, surprisingly, have neglected the mechanisms that control ROS production within mitochondria. Uncoupling proteins (UCPs), mitochondrial transporters of the inner membrane, are involved in the control of redox state of cells and in the production of mitochondrial ROS. Given their function, UCPs might therefore represent a major mechanistic link between metabolic activity and fitness. We suggest that by exploring the role of expression and function of UCPs both in experimental as well as in comparative studies, evolutionary biologists may gain better insight into this link.  相似文献   

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Recent experiments in vivo and in vitro have advanced our understanding of the sites and mechanisms involved in mammalian respiratory rhythm generation. Here we evaluate and interpret the new evidence for two separate brainstem respiratory oscillators and for the essential role of emergent network properties in rhythm generation. Lesion studies suggest that respiratory cell death might explain morbidity and mortality associated with neurodegenerative disorders and ageing.  相似文献   

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Ascidians are marine protochordates at the evolutionary boundary between invertebrates and vertebrates. Ascidian larvae provide a simple system for unraveling gene regulation networks underlying the formation of the basic chordate body plan. After being used for over a century as a model for embryological studies, ascidians have become, in the past decade, an increasingly popular organism for studying gene regulation. Part of the renewed appeal of this system is the use of electroporation to introduce transgenic DNAs into developing embryos. This method is considerably more efficient than conventional microinjection assays and permits the simultaneous transformation of hundreds of embryos. Electroporation has allowed the identification and characterization of cis-regulatory DNAs that mediate gene expression in a variety of tissues, including the notochord, tail muscles, CNS, and endoderm. Electroporation has also provided a simple method for misexpressing patterning genes and producing dominant mutant phenotypes. Recent studies have used electroporation to create "knock-out" phenotypes by overexpressing dominant negative forms of particular proteins. Here we review the past and present uses of electroporation in ascidian development, and speculate on potential future uses.  相似文献   

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D J Hauben  O Shulman  Y Levi  J Sulkes  A Amir  R Silfen 《Plastic and reconstructive surgery》2001,108(6):1582-8; discussion 1589-90
Sternal wound infection is surgically treated by debridement of the infected sternum and closure of the defect with a muscular flap. These operations tend to be long, stressful, and time-consuming and to involve heavy blood loss. To facilitate wound closure, the SpaceMaker balloon was applied intraoperatively to expand the pectoralis major muscles and enable tensionless closure with musculocutaneous flaps. The aim of the present study was to compare the effectiveness and feasibility of this technique with a variety of others described in the literature. The study population consisted of 40 consecutive patients with sternal wound infection following median sternotomy who were treated with the advancement flap, turnover flap, transposition flap, or SpaceMaker balloon-assisted advancement flap technique (n = 10 each). The balloon-assisted technique was associated with a shorter length of operation and fewer blood transfusions than the other methods. Furthermore, there was no need for reoperation and there were no cases of skin necrosis. In conclusion, closure with the SpaceMaker balloon-assisted bilateral pectoralis major musculocutaneous flap may serve as an adjunctive measure in the treatment of sternal wound infection. This technique seems to have advantages over simple pectoralis major musculocutaneous advancement, particularly for midsternal wounds.  相似文献   

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Brent B 《Plastic and reconstructive surgery》1999,104(2):319-34; discussion 335-8
Through the author's experience with 1200 cases during a 25-year period, this article presents technical improvements in ear reconstruction and proposes and discusses possible directions for further technical advancement. This article presents the rationale for the author's current methods of managing total ear repair. Throughout the article, the author stresses and demonstrates cartilage-sparing techniques that are designed to minimize the amount of cartilage used in a repair to preserve maximum chest wall integrity. This article also presents the latest method of framework fabrication, showing differences in construction between younger and older patients; a new method that constructs a tragus as an integral part of the framework; a method that maintains ear projection with a scalp-banked cartilage wedge; and a method that solves the always frustrating low hairline by presurgical laser treatment. In addition, the concept of creating autogenous frameworks by tissue engineering is pursued and discussed in practical clinical terms. A survey of 1000 microtia patients indicates that surgically constructed ears remain durable, withstand trauma well, and provide consistent emotional relief and psychological benefits through the repair.  相似文献   

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Human papillomaviruses (HPVs) have been recognized as the main etiologic agent of cervical cancer and other anogenital neoplasms, and a leading cause of death from cancer worldwide. In the last twenty years, extensive research has contributed to document the molecular mechanisms of virus persistence and malignant transformation, confirming a direct role of viral proteins in these processes. A clear understanding of the molecular epidemiology of HPVs and the availability of powerful molecular diagnostic techniques have provided the background for prevention strategies of HPV-related carcinomas. Since these viruses are highly prevalent in the general population, strict screening programs are still necessary. Recently, major breakthroughs have emerged from immunological studies. Indeed, these studies have paved the way for medical treatment of HPV infections and provided the first highly effective preventive vaccines. For these principal reasons, the time has come for a great effort towards the eradication of these important human pathogens. The present review summarizes the main aspects of the virology, molecular epidemiology and molecular biology of HPV infection and highlights the recent perspectives of prevention and treatment of the HPV-related disease.  相似文献   

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Surgical outcomes and patient satisfaction with composite resection and primary closure for the management of upper-lip defects following Mohs' surgery were evaluated. Twenty-seven patients underwent upper-lip reconstruction following Mohs' surgery from 1993 to 1997. Twelve of these patients were selected for this report based on adequate follow-up examinations and photographs. There were nine women and three men with a mean age of 46 years (range, 33 to 70 years). Eleven patients underwent Mohs' surgery for basal cell carcinoma and one patient for squamous cell carcinoma of the upper lip. The defects varied in size and location, often extending beyond a single aesthetic subunit. The reconstruction was performed an average of 7 days after Mohs' surgery (range, 1 to 23 days). In 50 percent of the cases, a full-thickness excision was performed, which included orbicularis oris and inner-lip mucosa. The functional results were graded as near normal to normal in all cases. There were no observed changes in oral continence, eating or speech. Two patients experienced numbness medial to the operative site, but this had no adverse affect on lip function. The aesthetic results were graded as very good to excellent in all cases. Eleven of the 12 patients were satisfied with their lip appearance and function. Conventional wisdom dictates that during reconstruction of upper-lip defects, one should attempt to maintain a majority of the uninvolved tissue for the best result. Although these techniques result in wound closure, they fail to consider lip aesthetics. By using a vertically oriented composite resection of the tipper lip with the additional resection of uninvolved tissue, normal lip architecture is maintained. In our experience, this results in a superior aesthetic and functional result.  相似文献   

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