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61.
Femoral neck (FN) bone mineral density (BMD) is the most commonly used skeletal site to estimate fracture risk. The role of lumbar spine (LS) BMD in fracture risk prediction is less clear due to osteophytes that spuriously increase LS BMD, particularly at lower levels. The aim of this study was to compare fracture predictive ability of upper L1–L2 BMD with standard L2–L4 BMD and assess whether the addition of either LS site could improve fracture prediction over FN BMD. This study comprised a prospective cohort of 3016 women and men over 60?yr from the Dubbo Osteoporosis Epidemiology Study followed up for occurrence of minimal trauma fractures from 1989 to 2014. Dual-energy X-ray absorptiometry was used to measure BMD at L1–L2, L2–L4, and FN at baseline. Fracture risks were estimated using Cox proportional hazards models separately for each site. Predictive performances were compared using receiver operating characteristic curve analyses. There were 565 women and 179 men with a minimal trauma fracture during a mean of 11?±?7?yr. L1–L2 BMD T-score was significantly lower than L2–L4 T-score in both genders (p?<?0.0001). L1–L2 and L2–L4 BMD models had a similar fracture predictive ability. LS BMD was better than FN BMD in predicting vertebral fracture risk in women [area under the curve 0.73 (95% confidence interval, 0.68–0.79) vs 0.68 (95% confidence interval, 0.62–0.74), but FN was superior for hip fractures prediction in both women and men. The addition of L1–L2 or L2–L4 to FN BMD in women increased overall and vertebral predictive power compared with FN BMD alone by 1% and 4%, respectively (p?<?0.05). In an elderly population, L1–L2 is as good as but not better than L2–L4 site in predicting fracture risk. The addition of LS BMD to FN BMD provided a modest additional benefit in overall fracture risk. Further studies in individuals with spinal degenerative disease are needed.  相似文献   
62.
The functional characteristics of the ascending limb of Henle's loop were examined during hypotonic saline infusion by measuring solutefree water clearance (C(H2O)) at varying rates of solute delivery. The influence of expansion of extracellular volume was studied by comparing C(H2O) during hypotonic saline diuresis in normal dogs with dogs whose extracellular volume had been expanded acutely by saline infusions or chronically by the administration of deoxycorticosterone acetate and salt.In normal animals hypotonic saline infusions greatly increased urine flow (V) and C(H2O) without appreciably augmenting osmolar clearance (C(osm)). C(H2O) was, therefore, analyzed as a function of V, rather than C(osm), since V was the best estimate of delivery of filtrate to the diluting segment. C(H2O) increased as a linear function of V without any evidence of saturation.The validity of interpreting increases in C(H2O) and V as indications of increased sodium reabsorption and delivery was reinforced by tissue studies that disclosed a rise in papillary osmolality with rising urine flows. The observed increase in C(H2O) and V could not, therefore, be due to a decrease in back diffusion of solute-free water as a result of a diminished osmotic driving force, but probably represented increased formation consequent to augmented delivery as a result of decreased fractional reabsorption in the proximal tubule.In animals whose extracellular volume was acutely or chronically overexpanded before the infusion of hypotonic saline, sodium excretion was greater, and C(H2O) less, at any given V. Although the curve relating C(H2O) to V was flatter than in the control group, no tubular maximum was observed. The diminished C(H2O) in this group was interpreted to mean that massive expansion of extracellular volume inhibits sodium reabsorption in the ascending limb of Henle's loop.  相似文献   
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The effect of habitual cocoa consumption on arterial stiffness and wave reflection indexes, as well as on peripheral and central blood pressure, was assessed in 198 healthy subjects. In conclusion, higher cocoa intake was an independent determinant of low arterial stiffness and wave reflection indexes and was also independently associated with significantly lower central (aortic) pulse pressure.  相似文献   
65.
Pituitary tumor apoplexy: a review   总被引:1,自引:0,他引:1  
Pituitary tumor apoplexy is an uncommon syndrome resulting often spontaneously from hemorrhage or infarction of a pre-existing pituitary adenoma. As the primary event involves the adenoma, the syndrome should be referred to as pituitary tumor apoplexy and not as pituitary apoplexy. The sudden increase in sellar contents compresses surrounding structures and portal vessels, resulting in sudden, severe headache, visual disturbances, and impairment in pituitary function. Initial management of patients with pituitary tumor apoplexy includes supportive therapy (intravenous fluids and corticosteroids), following which many patients exhibit clinical improvement. Because those patients can be effectively managed with supportive measures, many who remain clinically and neurologically unstable might benefit from urgent surgical decompression by an experienced neurosurgeon. All patients presenting with this syndrome require long-term follow-up to treat any residual tumor and/or pituitary dysfunction. Close interaction between members of the management team is necessary for optimal patients' outcome.  相似文献   
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A total of 1712 men aged 40 to 59 years in two rural cohorts of northern and central Italy have been followed up for 25 years after an entry examination in 1960. Forty one individual characteristics have been considered as possible predictors of death in the next 25 years. After exclusion of 55 men with life threatening diseases (cardiovascular and cancer) and of 161 men because of missing measurements, 1495 men have been analysed for relation between entry factors and subsequent death (n = 670). Twelve factors eventually emerged as powerful predictors of future death: in hierarchical order, age, blood pressure, forced expiratory volume, cigarette smoking, xanthelasma, mother life-status, arm circumference, father life-status, shoulder-pelvis ratio, vital capacity, arcus senilis, and serum cholesterol. Discrimination as provided by logistic modelling placed 19.6% of all cases in the upper decile of the estimated risk, 36.8% in the upper quintile, 2.5% in the lowest decile, and 7.1% in the lowest quintile. Out of those located in the lowest decile of risk, 11.4% died within 25 years while the corresponding percentage in the upper decile was 87.3%. Use of the Cox model yielded slightly better coefficients than logistic function.  相似文献   
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69.
OBJECTIVE: To determine the disease sensitivity and specificity of testing for autoantibodies against 2 of the 3 main human centromere antigenic components, CENP-A and CENP-B (recombinant, expressed in baculovirus). METHODS: ELISA with CENP-A and CENP-B antigens were used to test 45 sera showing a centromere pattern by immunofluorescence (IFA) and sera from 96 patients with systemic sclerosis (SSc), subdivided into diffuse (dSSc) and limited (lSSc) forms. For controls, the same tests were performed on sera from 100 patients with rheumatoid arthritis (RA), 100 with systemic lupus erythematosus (SLE), and 50 random blood donors. Sera from all the patients with SSc were also tested for the presence of anti-Scl70 antibody by ELISA (bovine antigen), and for pattern and titer by IFA (HEp-2 cells). RESULTS: Of the 45 IFA positive sera, 93% were positive for anti-CENP-A and 91% for anti-CENP-B. There was a very good quantitative correlation between the antibody levels against these 2 centromere components (r = 0.597; p<0.001). Anti-CENP-A and B were found in 48% of patients with lSSc, and in 11% and 9%, respectively, of those with dSSc. The difference in the frequency of anti-CENP-A between the 2 patient groups was significant (chi-squared, p<0.001). Similar levels of anticentromere staining pattern by IFA were observed for these 2 groups. Anti-Scl70 was elevated in 8% of lSSc and 25% of dSSc patients; this difference was also significant (chi-squared, p = 0.02). Neither CENP-A nor CENP-B reacted with IgG from SSc patients containing anti-Scl70. The frequency of abnormal levels in patients with SLE and RA was, respectively, 11% and 3% for anti-CENP-A and 4% and 3% for anti-CENP-B. The reaction of IgG from SLE and RA patients with CENP-A was not inhibited by histone H3, i.e., it was not due to recognition of the histone-like domain in CENP-A. Thus, when 96 SSc patients were compared to 200 patients with RA and SLE, the disease specificity of anti-CENP-A and B was 93% and 96.5%, respectively. CONCLUSION: In addition to IFA, ELISA tests for CENP-A and CENP-B yield results with similar sensitivity and specificity for the diagnosis of SSc. CENP-A and CENP-B are primarily associated with lSSc. In SSc the autoantibody response is directed simultaneously and with similar amplitude against these 2 components of the centromere structure, whereas in other autoimmune diseases the response is directed mainly against one of the 2 components.  相似文献   
70.
Abstract:   The expanding role of the anesthesiologist as a "perioperative physician" places ever-increasing demands upon his or her clinical skills and knowledge. One area of growing concern for the anesthesiologist involves the perioperative assessment and management of the opioid-tolerant chronic pain patient. Opioids occupy a position of unsurpassed clinical utility for the treatment of many types of painful conditions. Coupled with noticeable shifts in physician attitudes that have occurred in recent years regarding the use of opioids for the treatment of benign and malignancy-related pain, many more patients are presenting for surgical procedures who are opioid tolerant. It is important therefore that the practicing anesthesiologist become familiar with the currently available opioid formulations, including drug interactions and side effects, in order to better plan the patient's perioperative anesthetic needs and management. Unfortunately, there is a lack of scientifically rigorous studies in this important area, and most of the information must be derived from anecdotal reports and personal experience of anesthesiologists working in this field. In this review, we shall discuss some aspects of current chronic pain management, the newer forms of opioid administration which may be unfamiliar to the anesthesiologist, as well as clinical aspects of opioid use and tolerance including the impact it may have on perioperative anesthetic management.  相似文献   
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