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Hippocampal circuits are among the best described networks in the mammalian brain, particularly with regard to the alterations that arise during normal aging. Decades of research indicate multiple points of vulnerability in aging neural circuits, and it has been proposed that each of these changes make a contribution to observed age-related cognitive deficits. Another view has been relatively overlooked - namely that some of these changes arise in adaptive response to protect network function in aged animals. This possibility leads to a rather different view on the biological variation of function in the brain of older individuals. Using the hippocampus as a model neural circuit we discuss how, in normally aged animals, some age-related changes may arise through processes of neural plasticity that serve to enhance network function rather than to hinder it. Conceptually disentangling the initial age-related vulnerabilities from changes that result in adaptive response will be a major challenge for the future research on brain aging. We suggest that a reformulation of how normal aging could be understood from an adaptive perspective will lead to a deeper understanding of the secrets behind successful brain aging and our recent cultural successes in facilitating these processes., (Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.)

Objective: To investigate the probability of undergoing filtration surgery in either 1 or both eyes in patients in whom open-angle glaucoma was newly diagnosed., Methods and Design: A retrospective community-based study of 295 residents of Olmsted County, Minnesota, in whom open-angle glaucoma was newly diagnosed between January 1, 1965, and December 31, 1980, was performed. Kaplan-Meier methods were used to estimate the cumulative probability of undergoing filtration surgery during a 20-year period., Results: At 20 years of follow-up, the Kaplan-Meier cumulative probability of undergoing filtration surgery in at least 1 eye was estimated to be 23% (95% confidence interval, 16%-30%), and in both eyes the estimate was 12% (95% confidence interval, 6%-17%). Patients with optic nerve damage at the time of diagnosis were more likely to undergo surgery than patients with elevated intraocular pressure but no damage (1 eye, 39% vs 15%; both eyes, 27% vs 5%)., Conclusion: This retrospective study of a white population newly diagnosed as having and treated for open-angle glaucoma indicates that while most patients did not undergo filtration surgery in the course of glaucoma therapy, at least one third of those with glaucomatous damage at the time of diagnosis underwent filtration surgery.

Objective: To assess the outcomes of anesthesia and surgery for men and women 100 years of age and older., Design: Retrospective cohort study in the 20-year time period from 1975 to 1994, with follow-up through 1995., Setting: Mayo-affiliated hospitals and Olmsted Community Hospital, Rochester, Minnesota., Participants: All men and women 100 years of age and older who underwent surgery at a participating hospital., Measurements: Forty-eight-hour and 30-day perioperative morbidity and mortality; long-term survival., Results: Thirty-one men and women aged 100 to 107 years underwent 42 procedures. One major complication (3%) within 48 hours was observed. The 48-hour, 30-day, and 1-year mortality rates were 0%, 16.1%, and 35.5%, respectively. When compared with survival rates for age-, gender-, and calendar year of birth-matched peers from the general population, the survival rate for centenarians who underwent surgery and anesthesia was comparable to the rate expected., Conclusion: These data suggest that people 100 years of age and older who have operable diseases or injuries should not be denied surgical interventions because of perceived risks associated with their advanced age.

Background: The prognostic value of exercise thallium-201 imaging has been well established in referral patient populations at tertiary care centers, but these results may be influenced by referral bias., Methods: This study was performed to evaluate the prognostic value of thallium imaging in a community-based population of 446 residents of Olmsted County, Minn. Eleven variables were prospectively selected and tested for their associations with outcome end points., Results: Four variables (age, history of myocardial infarction, number of abnormal thallium segments on the postexercise images, and increased thallium lung uptake) contained the most independent prognostic information. For the end point overall mortality rate, the multivariate chi-square values were 17.2 (p < 0.0001) for age and 20.9 (p < 0.0001) for the number of abnormal thallium segments on the postexercise images. Five-year survival rate for patients older than the median age of 59 years with an abnormal scan was 84% versus 97% for patients < or = 59 years of age with a normal scan., Conclusion: Exercise thallium imaging was useful for prognostic purposes in this relatively low-risk community population, confirming the findings of referral population studies.

Decision and cost-utility analyses considered the tradeoffs of treating patent ductus arteriosus (PDA) using conventional surgery versus transcatheter implantation of the Rashkind occluder. Physicians and informed lay parents assigned utility scores to procedure success/complications combinations seen in prognostically similar pediatric patients with isolated PDA treated from 1982 to 1987. Utility scores multiplied by outcome frequencies from a comparative study generated expected utility values for the two approaches. Cost-utility analyses combined these results with simulated provider cost estimates from 1989. On a 0-100 scale (worst to best observed outcome), the median expected utility for surgery was 99.96, versus 98.88 for the occluder. Results of most sensitivity analyses also slightly favored surgery. Expected utility differences based on 1987 data were minimal. With a mean overall simulated cost of $8,838 vs $12,466 for the occluder, surgery was favored in most cost-utility analyses. Use of the inherently less invasive but less successful, more risky, and more costly occluder approach conferred no apparent net advantage in this study. Analyses of comparable current data would be informative.

Objective: To analyze population-based trends in cataract extraction., Design: Rochester Epidemiology Project databases; which capture virtually all health care services provided to residents of Olmsted County, Minnesota, were used to perform retrospective cohort analyses of rates of primary cataract extractions performed between 1980 and 1994., Participants: The population of Olmsted County, Minnesota., Main Outcome Measures: Incidence rates adjusted to the age and sex distribution of the 1990 US white population were analyzed using Poisson regression., Results: The 4257 procedures performed on 3176 patients of all ages represented overall annual age-adjusted rates of 404 procedures per 100,000 females and 320 per 100,000 males. Annual age- and sex-adjusted rates for both sexes combined rose from 133 procedures per 100,000 in 1980 to a peak of 507 per 100,000 in 1992. The rates fell to 470 per 100,000 in 1994. Manual review of a random sample of records estimated case overascertainment at 0.9%., Conclusions: With the exception of 1988 and 1989, rates of cataract surgery in this geographically circumscribed population increased every year between 1980 and 1992. Data from 1993-1994 indicate that rates may have plateaued and possibly declined slightly. If sustained, these patterns could have major implications for future utilization of ophthalmologic resources.

Purpose: Graft-related complications must be factored into the long-term morbidity and mortality rates of abdominal aortic aneurysm (AAA) repair. However, the true incidence may be underestimated because some patients do not return to the original surgical center when a problem arises., Methods: To minimize referral bias and loss to follow-up, we studied all patients who underwent AAA repair between 1957 and 1990 in a geographically defined community where all AAA operations were performed and followed by a single surgical practice. All patients who remained alive were asked to have their aortic grafts imaged., Results: Among 307 patients who underwent AAA repair, 29 patients (9.4%) had a graft-related complication. At a mean follow-up of 5.8 years (range, < 30 days to 36 years), the most common complication was anastomotic pseudoaneurysm (3.0%), followed by graft thrombosis (2.0%), graft-enteric erosion/fistula (1.6%), graft infection (1.3%), anastomotic hemorrhage (1.3%), colon ischemia (0.7%), and atheroembolism (0.3%). Complications were recognized within 30 days after surgery in eight patients (2.6%) and at late follow-up in 21 patients (6.8%). These complications were observed at a median follow-up of 6.1 years for anastomotic pseudoaneurysm, 4.3 years for graft-enteric erosion, and 0.15 years for graft infection. Kaplan-Meier 5- and 10-year survival free estimates were 98% and 96% for anastomotic pseudoaneurysm, 98% and 95% for combined graft-enteric erosion/infection, and 98% and 97% for graft thrombosis., Conclusions: This 36-year population-based study confirms that the vast majority of patients who undergo standard surgical repair of an abdominal aortic aneurysm remain free of any significant graft-related complication during their remaining lifetime.

Objectives: To determine the incidence of primary angle-closure glaucoma (PACG) and to assess the visual outcomes of patients treated for PACG., Design: Population-based retrospective incidence study., Setting and Patients: Residents of Olmsted County, Minnesota, aged 40 years and older and diagnosed with PACG in the 13-year period between January 1, 1980, and December 31, 1992., Main Outcome Measure: Incident cases of PACG identified through the Medical Diagnostic Index of Mayo Clinic, Rochester, Minn, and the Rochester Epidemiology Project., Results: Thirty-six incident cases were identified. The mean annual age-and sex-adjusted incidence per 100000 people aged 40 years and older was 8.3 (95% confidence interval, 5.6-11.0). The probability of monocular blindness associated with PACG at the time of diagnosis was 14%. Among patients not monocularly blind at diagnosis, the 5-year probability of developing monocular blindness associated with PACG was 4%., Conclusions: Primary angle-closure glaucoma is an uncommon disease in our community. Most of the patients blinded by PACG were blind at the time the condition was diagnosed.

Purpose: Nonarteritic anterior ischemic optic neuropathy is the most common acute optic nerve disease of adults over age 50 years. This study determined the incidence of acute nonarteritic anterior ischemic optic neuropathy in the circumscribed population of Olmsted County, Minnesota., Methods: This was a retrospective study of the incidence of acute nonarteritic anterior ischemic optic neuropathy between 1981 and 1990. The Rochester Epidemiology Project medical records linkage system facilitates identification of the medical records of virtually all Olmsted County residents with a given diagnosis. All cases of acute nonarteritic anterior ischemic optic neuropathy that fulfilled certain inclusion and exclusion criteria were identified., Results: Twenty-two cases in 21 patients (11 men and 10 women) were recorded. The crude annual incidence rate was 10.3 per 100,000 individuals (95% confidence interval [CI] = 5.1 to 18.4). When adjusted to the age and sex distribution of the 1990 United States white population, the incidence rate was 10.2 per 100,000 (95% CI = 6.5 to 15.6). At diagnosis, the median age was 72 years, mean visual acuity was 20/200 in the affected eye, and the most common visual field defect was an altitudinal deficit (10 cases)., Conclusions: Although results of this small study should be interpreted cautiously, extrapolation of our findings to the United States white population indicates that nearly 5,700 new cases of acute nonarteritic anterior ischemic optic neuropathy may be expected to occur each year in this group.

Background: Limited population-based data are available on trends in the incidence of arterial surgery, balloon angioplasty, and amputation for arterial occlusive disease of the legs over the past two decades., Methods: We identified all elective and emergency arterial operations, balloon angioplasty procedures, and amputations performed for all residents of a defined community, Olmsted County, Minn., between 1973 and 1992. We focused on gender mix, type of procedure, and secular trends in utilization., Results: A total of 1155 procedures were performed, including 733 arterial surgical procedures, 59 balloon angioplasty procedures, and 363 amputations (288 major and 75 minor). Emergency procedures were performed in 12%. Suprainguinal inflow procedures were the most common arterial reconstruction (60%) compared with infrainguinal procedures (40%). The incidence of all revascularization procedures increased in the first decade but reached a plateau after 1985. Utilization rates of revascularization procedures from 1988 to 1992 were higher for men (141.9/100,000 person-years [p-yr]) than women (57.4/100,000 p-yr.). Angioplasty (17.0/100,000 p-yr) rates lagged behind surgery until 1985, but tripled in the past 10 years and have not yet reached a plateau. Although minor amputation rates remain unchanged in 20 years, major amputation rates have been reduced by 50% from 36.7/100,000 p-yr between 1973 and 1977 to 19.0/100,000 p-yr from 1988 to 1992., Conclusions: From this long-term population-based analysis (1973 to 1992), we conclude that increased vascular surgery and balloon angioplasty rates have coincided with a significant reduction in major amputation rates in the past 10 years.

Background: Patients with asthma are thought to be at high risk for pulmonary complications to develop during the perioperative period, and these complications may lead to serious morbidity. Existing medical records were reviewed to determine the frequency of and risk factors for perioperative pulmonary complications in a cohort of residents of Rochester, Minnesota, who had asthma and who underwent anesthesia and surgery at the Mayo Clinic in Rochester., Methods: Medical records were reviewed for all residents of Rochester, Minnesota, who were initially diagnosed as having definite asthma according to strict criteria from 1 January 1964 through 31 December 1983 who subsequently had at least one surgical procedure involving a general anesthetic or central neuroaxis block at the Mayo Clinic (n = 706)., Results: Bronchospasm was documented in the perioperative records of 12 patients (1.7% [exact 95% confidence interval, 0.9 to 3%]). Postoperative respiratory failure developed in one of these patients. Laryngospasm developed in two additional patients during operation. All episodes of bronchospasm and laryngospasm in the immediate perioperative period were treated successfully. No episodes of pneumothorax, pneumonia, or death in the hospital were noted. For univariate analysis, characteristics associated with complications included the recent use of antiasthmatic drugs, recent asthma symptoms, and recent therapy in a medical facility for asthma. Patients in whom complications developed were significantly older at diagnosis and at surgery., Conclusions: The frequency of perioperative bronchospasm and laryngospasm was surprisingly low in this cohort of persons with asthma. These complications did not lead to severe respiratory outcomes in most patients. The frequency of complications was increased in older patients and in those with active asthma.

Background: Results of transcatheter implantation of the Rashkind double umbrella occluder for treatment of patent ductus arteriosus (PDA) have improved over time. We evaluated factors associated with changes in outcomes seen in the early clinical experience with this device., Methods and Results: We reviewed records of otherwise healthy pediatric patients undergoing occluder implantation for isolated PDA between 1982 and 1987 at six major US and Canadian referral centers. Logistic regression was used to assess the impact of ductal size, patient age and weight, calendar time, prior intrainstitutional occluder experience, and residual center effects on closure rates. There were no study deaths. Of 180 occluder placement attempts, 76.7% (95% confidence limits = 70.5%, 83.0%) produced PDA closure by auscultation at 14-month cardiology follow-up or its equivalent. Success probabilities increased in a linear fashion as ductus size decreased, ranging from 41.7% for large (4.1 to 9.0-mm) ducts to 89.4% for small (1.5 to 2.5-mm) lesions. PDA occluder closure rates also improved over time, increasing from 47.4% in 1982-1983 to 84.6% in 1986 and 83.1% in 1987. Multivariate logistic regression indicated that improved outcomes were mainly attributable to decrease in the size of treated ducts over time. Independent of this patient selection, improvements in outcome were less strongly associated with cumulative intracenter experience, calendar time, and age., Conclusions: Increasing closure rates seen over time primarily reflected more judicious selection of patients as experience accumulated. However, other factors also contributed to the observed trends. An analysis of current treatment results would be of considerable interest.

Background: Transcatheter implantation of the Rashkind PDA occluder is an alternative to conventional surgical closure of isolated patent ductus arteriosus. Neither the clinical outcomes nor the costs of these procedures have been formally compared., Methods: We performed a retrospective cohort study to evaluate the clinical outcomes within a seven-month period for comparable patients with patent ductus arteriosus who underwent either placement of an occluder or surgical closure. The patients were treated between 1982 and 1987 at 14 major North American centers where patent ductus arteriosus was closed predominantly by a surgical procedure or by the occluder technique. To estimate inpatient and follow-up costs, we multiplied the observed use of resources by 1989 unit costs based on hospital-accounting and physician-reimbursement data., Results: On the basis of cardiac auscultation at follow-up, the initial procedure resulted in closure of the ductus arteriosus in 77.3 percent of 185 patients in whom the occluder was implanted (95 percent confidence interval, 70.6 to 83.1 percent) and 99.8 percent of 446 surgical patients (95 percent confidence interval, 98.8 to 100.0 percent). Second procedures increased the percentage of successful closures to 87.6 percent (95 percent confidence interval, 81.9 to 92.0 percent) and 100.0 percent (95 percent confidence interval, 99.3 to 100.0 percent) for patients in the occluder and surgical groups, respectively. There were no deaths. Major complications occurred in 2.7 percent of the patients in whom the occluder was implanted (95 percent confidence interval, 0.9 to 6.2 percent) and 0.2 percent of the patients who underwent surgery (95 percent confidence interval, 0.0 to 1.2 percent); moderate complications in 16.8 percent (95 percent confidence interval, 11.7 to 22.9 percent) and 15.0 percent (95 percent confidence interval, 11.8 to 18.7 percent), respectively; and minor complications in 11.4 percent (95 percent confidence interval, 7.2 to 16.8 percent) and 24.9 percent (95 percent confidence interval, 20.9 to 29.2 percent). Including the cost of follow-up care, the mean estimated cost per case treated surgically was $8,838 (in 1989 U.S. dollars), as compared with $11,466 per case treated with the occluder technique. Sensitivity analyses based on our data identified no plausible situations in which the costs of surgery and of implantation of the occluder would be equal., Conclusions: The more effective and less costly surgical procedure was superior to transcatheter placement of the occluder for closure of isolated patent ductus arteriosus. Consequently, our results do not support the wide-spread dissemination of the occluder procedure for the management of this common congenital lesion.

Using the records of 72 patients treated at the University of Washington Burn Center, this study compared the results of early surgical excision (by 14 days postburn) and autografting to those of autografting after spontaneous separation and bedside debridement of burn eschar. Excised patients had shorter hospitalizations and lower rates of burn wound sepsis and serious burn wound contamination, and less use of potentially toxic antibiotics (p less than 0.05) than did the prognostically equivalent group treated before the introduction of early excision. Excised patients required more blood transfusions (p less than 0.05), but did not differ significantly from controls in rates of mortality or other inpatient complications, in the number of operations performed, or in the adjusted hospital costs. Evaluation of patients treated over the entire study period for more shallow burns indicated no concurrent change in other aspects of burn care which might account for the observed results. We conclude that early excision and grafting in young, otherwise healthy patients with 20 to 40 percent total body surface area burns that are likely to heal within 3 weeks is more effective than the more traditional management of slow wound separation and debridement.