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1.
It is known that exogenous 11-cis-retinol inhibits the recovery of photosensitivity of bleached rod outer segments (ROS) and 11-cis-retinol exists in the interphotorecepter matrix. We examined the conversion of 11-cis-retinol with bovine ROS. ROS was incubated with 11-cis-retinol under dim red light. Retinoids were extracted from the reaction mixture with hexane and analyzed by HPLC coupled with a fluorescence spectrophotometer. Isomerization of 11-cis-retinol to all-trans-retinol was observed in the presence of ROS. This isomerization was not suppressed by heat treatment and did not have stereospecificity. In addition, we incubated purified rhodopsin and phospholipids extracted from ROS with 11-cis-retinol. Rhodopsin was found to isomerize 11-cis-retinol to all-trans-retinol as well as ROS, but phospholipids did not. In contrast, the phospholipids inhibited the isomerization of 11-cis-retinol to all-trans-retinol by the purified rhodopsin. Commercially available phospholipids, especially phosphatidylserine, also inhibited the isomerization. Our results suggest that rhodopsin has activity for the isomerization of 11-cis-retinol to all-trans-retinol and may play an important role in the detoxification of 11-cis-retinol in the ROS.  相似文献   

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SM Browning  S Nivatvongs 《Canadian Metallurgical Quarterly》1998,186(4):441-5; discussion 445-6
BACKGROUND: Completion of the ileal pouch to anal anastomosis (IPAA) is neither always possible nor advisable based on intraoperative findings. This study was undertaken to document the incidence of and reasons for intraoperative abandonment of IPAA in a series of over 1,700 attempts. STUDY DESIGN: A retrospective review of the Mayo Clinic surgical index from January 1981 through December 1995. Patients with the preoperative diagnosis of chronic ulcerative colitis or familial adenomatous polyposis for whom IPAA was planned but not completed are the subject of this report. Comparison is made to patients with a completed IPAA from the Mayo Clinic IPAA registry. RESULTS: During a 15-year period, 1,789 IPAA attempts were made. Intraoperative abandonment occurred in 74 (4.1%). Patients in whom the operation was abandoned were older than patients in whom it was not (38 versus 33 years, p < 0.01), with age older than 40 years conferring a relative risk of 1.87 versus age younger than 40 (95% confidence interval, 1.19-2.94%). IPAA was abandoned for technical reasons in 32 (43%), intraoperative diagnosis of Crohn's disease in 27 (36%), colorectal cancer in 10 (14%), mesenteric desmoid in 3 (4%), and miscellaneous reasons in 2 (3%) patients. Fifty-one (69%) patients underwent proctocolectomy and ileostomy and 23 (31%) underwent sphincter preserving procedures. Of these, 2 underwent subsequent successful IPAA. CONCLUSIONS: Preoperative counseling for IPAA should include discussion of the risk of intraoperative abandonment (4.1%). Older patients are at increased risk. If the IPAA is abandoned for reversible reasons, preservation of the anal sphincter preserves the option of a subsequent IPAA.  相似文献   

4.
OBJECTIVES: The purpose of this study was to determine the safety and efficacy of rescue echocardiographically guided pericardiocentesis as a primary strategy for the management of acute cardiac perforation and tamponade complicating catheter-based procedures. BACKGROUND: In this era of interventional catheterization, acute tamponade from cardiac perforation as a complication is encountered more frequently. The safety and efficacy of echocardiographically guided pericardiocentesis in this life-threatening situation and outcomes of patients managed by this technique are unknown. METHODS: Of the 960 consecutive echocardiographically guided pericardiocenteses performed at the Mayo Clinic (1979 to 1997), 92 (9.6%) were undertaken in 88 patients with acute tamponade that developed in association with a diagnostic or interventional catheter-based procedure. Most of the patients were hemodynamically unstable at the time of pericardiocentesis, with clinically overt tamponade in 40% and frank hemodynamic collapse (systolic blood pressure <60 mm Hg) in 57%. Clinical end points of interest were the success and complication rates of rescue pericardiocentesis and patient outcomes, including the need for other interventions, clinical and echocardiographic follow-up findings and survival. RESULTS: Rescue pericardiocentesis was successful in relieving tamponade in 91 cases (99%) and was the only and definitive therapy in 82% of the cases. Major complications (3%) included pneumothorax (n=1), right ventricular laceration (n=1) and intercostal vessel injury with right ventricular laceration (n=1); all were treated successfully. Minor complications (2%) included a small pneumothorax and an instance of transient nonsustained ventricular tachycardia; all were resolved spontaneously. Further surgical intervention was performed in 16 patients (18%). No deaths resulted from the rescue pericardiocentesis procedure itself. Early death (<30 days) in this series was due to injuries from cardiac catheter-based procedures (n=3), perioperative complications (n=2) and underlying cardiac diseases (n=2). Clinical or echocardiographic follow-up for a minimum of 3 months or until death (if <3 months) for recurrent effusion or development of pericardial constriction was achieved in 87 (99%) of the patients. CONCLUSIONS: Echocardiographically guided pericardiocentesis was safe and effective for rescuing patients from tamponade and reversing hemodynamic instability complicating invasive cardiac catheter-based procedures. For most patients, this was the definitive and only therapy necessary.  相似文献   

5.
OBJECTIVES: This study sought to evaluate changes in early morbidity and mortality as well as predictors of outcome in our most recent 339 patients undergoing modified Fontan operations. BACKGROUND: The Fontan operation is the preferred definitive palliation for patients with functional single ventricles. Previously reported early mortality rates after Fontan operation have been substantial. METHODS: Records of 339 consecutive patients who had a Fontan operation at the Mayo Clinic between 1987 and 1992 (recent cohort) were reviewed. This cohort was compared with the previous 500 patients who had Fontan operations performed between 1973 and 1986 (early cohort). RESULTS: Recently, overall early mortality after Fontan has decreased significantly compared with that for the early cohort (from 16% to 9%, p = 0.002). This decline occurred despite increased anatomic complexity of patients. Short-term posthospital survival has also improved significantly in recent patients. One-year survival improved to 88% from 79%, and 5-year survival to 81% from 73% (p = 0.006). Patients with common atrioventricular valves and those who took daily preoperative diuretic medication or had either postoperative renal failure or elevated postbypass right atrial pressure were at increased risk for early mortality. Young age was not found to be a risk factor for early mortality. Early mortality for patients with heterotaxia decreased dramatically: recent 30-day mortality was 15% compared with 41% in the early heterotaxy cohort. CONCLUSIONS: Many factors may have contributed to decreased early mortality after Fontan. Improved patient selection, younger age at time of operation, refinements in surgical techniques and postoperative management may all have had important roles. Proposed technical modifications of the Fontan operation must be evaluated in light of these improved results.  相似文献   

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In neurodegenerative disorders, hyperphosphorylated tau proteins aggregate into abnormal filaments. In the present study, tau protein alterations were studied in one corticobasal degeneration and seven Pick's disease cases using specific immunological probes. The typical lesions of corticobasal degeneration and Pick's disease were revealed by immunohistochemistry, including the presence of Pick bodies and achromatic swollen neurons, neuritic alterations, and neurofibrillary tangles. Tau-immunoreactive glial tangles were also observed. By immunoblotting, the case of corticobasal degeneration was characterized by the tau profile previously reported to occur in progressive supranuclear palsy with an intense labeling of the two tau 64 and 69 bands, while tau 55 was not visualized. In Pick's disease cases with Pick bodies and neurofibrillary tangles, a tau triplet similar to that encountered in Alzheimer's disease (tau 55, 64 and 69) was detected. Furthermore, a particular tau profile was found in four Pick's disease cases showing only Pick bodies and no neurofibrillary tangles. In these cases, tau 55 and 64 were strongly immunoreactive, whereas tau 69 was almost unlabeled. These differences are likely to be related to particular pools of tau isoforms present within the degenerating neurons. Since there is a great diversity of neurodegenerative disorders with substantial clinical and neuropathological overlap, the electrophoretic profile of tau proteins could represent a useful marker for the type of neurodegeneration.  相似文献   

7.
KC Simmons  R Mayo 《Canadian Metallurgical Quarterly》1997,30(2):117-31; quiz 131-2
The purpose of this study was to determine clinicians' attitudes toward the Darley, Aronson, and Brown (1969a, 1969b; 1975a) method of classification for differential diagnostic of dysarthria. A national telephone survey was conducted of 100 speech-language pathologists involved in the assessment and treatment of patients with dysarthria. Clinicians were questioned about their use of differential diagnosis as part of their service delivery to persons with dysarthria. Questions also focused on clinicians' perceptions of the helpfulness and difficulties of differential diagnosis. Results indicated that most clinicians use the Darley et al. (1969a, 1969b; 1975a) classification system for the differential diagnosis of dysarthria, stating that it is helpful in the design of a treatment protocol. A trend toward decreased perceived difficulty of differential diagnosis with increased years of work experience was observed. The clinical and academic training implications of these findings are discussed.  相似文献   

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An endocrine testing center (ETC) is a universal requirement for the practice of endocrinology. Modifications of the Mayo Clinic model for an ETC should be applicable to most endocrine practices. Key components of an ETC include a centralized testing area, registered nurse-physician team, detailed testing protocols, and patient education programs.  相似文献   

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An international meeting, 'Investment Strategies for Healthy Urban Communities', in Baltimore in September 1997 called on the the business community, city authorities and the health professions to reduce poverty and its adverse health consequences, especially in urban areas, in both the industrialized and developing world. In addition to issuing the Baltimore Charter on partnership for a healthy urban future, the meeting had two main outcomes: the innovative concept of Business for Health, championed by progressive business leaders from Australia, Europe and the United States, to promote business principles to reduce poverty, create enterprises and improve people's health, especially in developing countries; and the establishment by health professionals of an information network between cities and countries on poverty and ill-health. Two follow-up meetings in London in December 1997 resulted in an action plan to create networks of health professional groups and representatives of the business community.  相似文献   

10.
Postradiation sarcoma of bone is an uncommon but serious sequela of radiation therapy. Seventy-eight Mayo Clinic patients have been treated for sarcomas arising in irradiated bones. They received their initial radiotherapy for a wide variety of nonneoplastic and neoplastic conditions, both benign and malignant. Thirty-five sarcomas arose in bone that was normal at the time of radiotherapy, and 43 arose in irradiated preexisting osseous lesions. The latent period between radiotherapy and diagnosis of sarcoma averaged 14.3 years. Ninety percent of the postradiation sarcomas were either osteosarcomas or fibrosarcomas; chondrosarcoma, malignant (fibrous) histiocytoma, malignant lymphoma, Ewing's tumor, and metastasizing chondroblastoma also occurred. Prompt radical surgery, when feasible, is usually the treatment of choice for the sarcoma. About 30% of patients with sarcomas of the extremities or craniofacial bones survived 5 years without recurrence; there were no disease-free survivors among patients with tumors of the vertebral column, pelvis, or shoulder girdle. The low risk of sarcoma following radiotherapy for the treatment of cancer should not be a contraindication to its use in these patients; however, radiation therapy for benign bone tumors should be reserved for lesions that are not amenable to surgical treatment. An unusual case is also reported herein in which a fibrosarcoma was discovered in the humerus of a patient who had received radiotherapy 55 years previously for a verified osteosarcoma in the same site.  相似文献   

11.
In patients who have advanced soft tissue sarcoma that is no longer localized, systemic chemotherapy is the most reasonable option for treatment. The decision to treat or to use experimental or conventional agents should be based on the clinical assessment of anticipated net benefit in quality of life as well as the remote possibility of complete remission or even cure. Asymptomatic elderly patients with relatively stable disease might best be treated with watchful waiting; whereas younger excellent-performance-status patients should be offered the opportunity of participating in phase II or phase I studies of newer drugs and intensification regimens. Of the currently available single agents, only doxorubicin (or epirubicin) and ifosfamide show response rates greater than 20%; both show a definite dose-response relationship. Dacarbazine shows particular activity in uterine leiomyosarcomas. Combination chemotherapy regimens such as doxorubicin-ifosfamide show a higher response rate, but may be more toxic. New agents are needed. The current progress in our understanding of the molecular biology of sarcomas, and our expanded comprehension of the mechanism of action of cytotoxic drugs and the biology of drug resistance is cause for optimism.  相似文献   

12.
A study was carried out to determine the prevalence of cervical intra-epithelial neoplasia (CIN) among women referred to Harare Hospital Colposcopy Clinic with a history of an abnormal smear. During the period, 132 patients were seen and 79 (60 pc) had colposcopic findings suggestive of CIN and 17 (13 pc) had inflammatory changes and 36 (27 pc) had normal findings. Electrocautery was used to treat low grade CIN lesions, cone biopsy was performed for higher grades of CIN and a selected group underwent hysterectomy.  相似文献   

13.
OBJECTIVE: Multidisciplinary management of esthesioneuroblastoma has effected markedly increased survival during the past 20 years. The potential for radical craniofacial surgery for complete en bloc resection, the availability of advanced neuroimaging modalities, and the incorporation of neoadjuvant therapy into treatment strategies for tumor remission have all contributed to this accomplishment. However, a standard protocol for the management of these lesions has not been accepted; preoperative radiation and chemotherapy have been advocated, but neither radiographic nor clinical response has been quantified. METHODS: Thirty-four consecutive patients with biopsy-proven esthesioneuroblastoma treated at one institution from 1976 to 1994 were reviewed to determine the effects of preoperative radiation therapy, with or without chemotherapy, on tumor size and long-term survival. RESULTS: In a multivariate regression analysis, advanced age was predictive of decreased disease-free survival (P=0.008), whereas advanced Kadish stage was associated with a borderline higher rate of disease-related mortality (P=0.056). Two-thirds of the patients showed a significant reduction in tumor burden with adjuvant therapy. Patients with response to neoadjuvant therapy demonstrated a significantly lower rate of disease-related mortality (P=0.050). In this series, the overall 5- and 10-year survival rates were 81.0 and 54.5%, respectively. CONCLUSION: Preoperative neoadjuvant therapy provides a valuable complement to radical craniofacial resection, leading to reduction in tumor burden. Patients experiencing reduction in tumor volume by neoadjuvant therapy demonstrate an improved prognosis.  相似文献   

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PURPOSE: We determine the long-term durability of the AMS 800* artificial urinary sphincter in the correction of severe urinary incontinence, and evaluate mechanical versus nonmechanical failure and reoperation rates before (1983 to 1987) and after (1988 to present) the introduction of the narrow backing occlusive cuff design. MATERIALS AND METHODS: From January 1983 to October 1994 more than 400 patients received an AMS 800 artificial urinary sphincter placed by 1 surgeon and 323, mean age 60.4 years, met study requirements for review. Mean followup was 68.8 months (range 18 to 153). Only patients with a minimum of 18 months of followup were included in the study. Of the 313 men and 10 women in the study group sphincters were placed at the urethra in 272 and at the bladder neck in 51. All patients were followed from surgery to the date of sphincter failure. Etiology of the failures was recorded and divided into mechanical versus nonmechanical sphincters placed before and after the introduction of the narrow backing cuff. RESULTS: Overall, 58 of the 139 patients (42%) in the pre-narrow backing cuff group versus 31 of the 184 (17%) in the narrow backing cuff group required a first reoperation. Mechanical failure occurred in 29 cases (21%) with the pre-narrow backing and 14 (7.6%) with the narrow backing cuff. Nonmechanical failure developed in 24 cases (17%) with the pre-narrow backing and 17 (9%) with the narrow backing cuff. Ultimately 437 operations were required in the 323 patients, of whom 234 (72%) required no further surgical intervention at a mean followup of 68.8 months. CONCLUSIONS: Technological advances in the design and construction of the AMS 800 have dramatically decreased the reoperation and failure rates. These advances and improved surgical techniques provide an excellent long-term solution and increased continence in correctly selected patients with urinary incontinence.  相似文献   

16.
PURPOSE: Cushing's syndrome due to adrenal adenoma or adrenocortical carcinoma is rare. To understand better the clinical and biochemical presentation of this disorder, as well as therapy efficacy and patient survival, we conducted a retrospective review. MATERIALS AND METHODS: Between August 1971 and April 1994, 40 patients presented to our institution with adrenal Cushing's syndrome (27 adenomas and 13 carcinomas). These groups were analyzed with respect to clinical signs and symptoms preoperatively and postoperatively, biochemical analysis, length of postoperative steroid replacement therapy, disease recurrence and patient survival. Followup was obtained by chart review and telephone interviews and averaged 59.6 +/- 66.4 and 47.6 +/- 56.2 months for adenoma and carcinoma patients, respectively. RESULTS: Women predominated in both groups (26 of 27 adenomas, 11 of 13 carcinomas), and tumors affected the left adrenal gland more frequently (19 of 27 adenomas, 9 of 13 carcinomas). Adenoma patients were younger than carcinoma patients (39.6 +/- 14.4 versus 51.5 +/- 16.6 years, p = 0.026) and presented with smaller tumors (3.3 +/- 1.0 versus 8.6 +/- 4.5 cm., p = 0.001). There was a trend toward increased incidence of glucose intolerance among carcinoma patients but no significant differences in clinical signs or symptoms between adenoma and carcinoma patients could be made. Similarly, while there was no significant difference in biochemical evaluation of adenoma versus carcinoma patients, 24-hour urinary free cortisol and serum lactate dehydrogenase levels tended to be higher among carcinoma patients. In addition 17-ketosteroid and dehydroepiandrosterone sulfate levels were more elevated in carcinoma than in adenoma patients, and several adenoma patients actually had subnormal levels. Among adenoma patients mean length of steroid replacement therapy was 16.8 +/- 9.1 months. However, 7 adenoma patients (25.9%) required greater than 24 months of exogenous steroids, and only 1 of these patients was subsequently weaned off steroid replacement. There were no recurrences among adenoma patients, although there was 1 perioperative death due to hypoglycemia. Ten (76.9%) carcinoma patients had recurrences at a mean followup of 33 months. The 3 and 5-year survival rates were 41.5 and 31.2%, respectively. CONCLUSIONS: While presenting signs and symptoms and hormonal analysis may suggest benign or malignant disease, only tumor size and patient age are reliable preoperative indicators of adrenal adenoma versus adrenocortical carcinoma among patients with adrenal Cushing's syndrome. Surgery is curative for adenoma patients, but lifelong steroid replacement may be required. Survival remains poor among carcinoma patients.  相似文献   

17.
Until recently, chemotherapeutic intervention in advanced and metastatic non-small cell lung cancer (NSCLC) has been viewed with a certain degree of nihilism. Although meta-analysis of randomized clinical studies from the 1970s and 1980s comparing cisplatin-based chemotherapy to best supportive care in metastatic NSCLC showed improvement in survival, it was modest at best. A number of novel agents have been developed with significant activity against NSCLC in the past 5 to 6 years and are being incorporated into the therapy of this disease. These agents include paclitaxel, docetaxel, vinorelbine, gemcitabine, and irinotecan. Clearly there has been improvement in response rates, and in some cases the responses have been durable with an increase in the number of 1- and 2-year survivors. The next generation of studies has evaluated combinations of these novel agents with either cisplatin or carboplatin for patients with NSCLC and the results have been provocative, with 1-year survival rates as high as 54%. A randomized phase III study of the Eastern Cooperative Oncology Group has shown the superiority of paclitaxel-cisplatin regimens over etoposide-cisplatin for patients with advanced and metastatic NSCLC. The vinorelbine-cisplatin regimen has also proven to have significant, albeit modest benefit in survival when compared with cisplatin alone. These combination regimens have now become the reference regimens in ongoing randomized studies. There is continued interest in developing new agents, or selective approaches that effect novel targets with the hope of showing improved therapeutic activity. Some of these approaches include gene therapy, monoclonal antibodies, and introduction of antisense oligodeoxynucleotides. With better understanding of the molecular and cellular biology of lung cancer, the hope for the future is to combine the mechanistic approaches with new drug development to define an effective, optimal, and definitive regimen for NSCLC.  相似文献   

18.
PURPOSE: To determine the ophthalmic manifestations of vertebral artery dissections. METHODS: Fifty-one separate episodes of vertebral artery dissections evaluated at the Mayo Clinic from 1976 through 1992 were studied. In all cases, the diagnosis had been documented with angiography. RESULTS: There were 28 men and 19 women (mean and median age, 39 and 40 years, respectively; range, 8-61 years). There were ophthalmic findings in 86% of the episodes. Visual symptoms, in decreasing order of frequency, were diplopia (45% of the episodes), blurred vision (14%), transient visual dimming (8%), oscillopsia (4%), photophobia (4%), upside-down vision (2%), positional transient visual obscuration (2%), and unilateral dry eye (2%). Ophthalmic signs in decreasing order of frequency were nystagmus (37% of the episodes), ocular misalignment (cranial nerve palsy or skew) (33%), Horner syndrome (27%), decreased corneal sensation (22%), ptosis (16%), visual field defect (10%), abnormal pursuits and saccades (6%), ocular bobbing (4%), internuclear ophthalmoplegia (4%), anisocoria (4%), and pinpoint pupils (2%). CONCLUSION: Vertebral artery dissections occur in a relatively young population. Most of the patients in our study had ophthalmic manifestations at the time of diagnosis. Heightened awareness of this entity should enable the consulting ophthalmologist to have a role in the diagnosis and treatment of vertebral artery dissection.  相似文献   

19.
OBJECTIVE: To determine the change in accidental needlestick rates in the Phlebotomy Service at Mayo Clinic Rochester and to identify safety practices implemented from 1983 through 1996. MATERIAL AND METHODS: We retrospectively reviewed yearly Phlebotomy Service accidental needlestick rates from 1983 through 1996. Interviews were conducted with representatives of the Infection Control Committee and the management team for the Phlebotomy Service, and minutes of meetings of these two groups were reviewed to identify implemented safety improvements that may have had an effect on accidental needlestick exposures. RESULTS: Accidental needlestick exposures in the Phlebotomy Service declined from a high of 1.5/10,000 venipunctures to 0.2/10,000 venipunctures. Several safety improvements were made during that time, including the implementation of a one-handed recapping block, change to single-use evacuated tube holders, increased number and improved locations of disposal containers for needles, implementation of resheathing needles and retractable capillary puncture devices, discontinuation of the practice of changing needles before inoculation of blood culture bottles, increased emphasis on safety for new and experienced phlebotomists, and improved exposure reporting tools. CONCLUSION: We believe that the decrease in our accidental needlestick exposure rate is correlated with the changes in education, practices, and products that we have implemented.  相似文献   

20.
Between 1945 and 1970, 101 children (86 girls and 15 boys) with systemic lupus erythematosus were evaluated at the Mayo Clinic. Only 9 children were less than 9 years old at the time of diagnosis. The most frequent presenting complaint was arthralgia; fever, fatigue, and a "butterfly" malar rash also were common. Renal involvement, found in more than 76 per cent of patients, was a prognostically poor sign. The overall survival of children with renal involvement is improved by the use of adequate steroid therapy.  相似文献   

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