Ultrastructural alterations in caudate nucleus in aged cats

These studies provide information on the changes in the ultrastructure in the caudate nucleus of aged cats. The major findings was that there was a decrease in the density of synapses in caudate neuropil. This decrease occurred in animals after 3 years of age and remained relatively constant in older animals. In conjunction with this change a population of unusually long synapses also occurred. These larger synaptic appositions were associated with enlarged spine heads. The caudate also showed a number of qualitative ultrastructural alterations. Many neurons contained accumulations of lipofuscin or lipopigment granules in aged animals. These inclusions occurred in both soma and dendrites of neurons and all types of glial cells. A unique configuration of collapsed agranular cisterns also was observed in aged animals. The present results indicate that decreases in synaptic density may by one morphological event underlying functional alterations observed in caudate neurons in aged cats.     

Decreased Bone Mass and Strength in Ovariectomized Cynomolgus Monkeys (Macaca fascicularis)

Agents for prevention or treatment of osteoporosis must now be tested in a large animal species that exhibits bone remodeling. Ovariectomized, nonhuman primates provide one such model, and they consistently develop osteopenia accompanied by high bone turnover rates. The goal of this study was to further characterize this model, and particularly to determine the effect of ovariectomy on bone strength in vertebrae and femoral necks. Longitudinal evaluations of spinal bone mass and serum markers of bone turnover were performed in 19 sham-ovariectomized (SHAM) and 18 ovariectomized (OVX), domestically reared cynomolgus monkeys, aged >9 years. OVX monkeys lost bone relative to both baseline values and SHAM controls. Serum markers of bone turnover were increased by OVX. After 72 weeks, both vertebral bone compressive strength and femoral neck breaking strength were significantly decreased in OVX animals compared with SHAM. Ovariectomized cynomolgus monkeys, like postmenopausal women, develop accelerated bone loss, increased bone turnover, and reduced bone strength, and provide a suitable large animal model for efficacy studies with agents for prevention or treatment of osteoporosis. Received: 24 June 1996 / Accepted: 3 September 1996     

0～16岁城乡儿童骨骼矿物质含量及影响因素的研究

使用单光子骨矿物测定仪，自１９９４年初到１９９５年底，分别在河南省扶沟县和新乡市测定了３３２名健康的０～１６岁城乡儿童右前臂１／３处桡骨和尺骨的骨矿物质含量（ＢＭＣ），采用逐步多元回归分析了多个独立变量对桡骨ＢＭＣ和测量部位骨宽度的影响。结果显示：桡骨和尺骨的ＢＭＣ、骨宽度（ＢＷ）、ＢＭＣ／ＢＷ和前臂长度均随年龄而增加，０～６岁城市儿童的ＢＭＣ高于农村儿童；桡骨ＢＭＣ与所测量部位的ＢＷ呈正相关，年龄、体重和身高对桡骨ＢＭＣ都显示出显著和独立的正影响；儿童的桡骨ＢＭＣ与年龄呈显著正相关；而桡骨ＢＭＣ与体重的比值与年龄呈显著负相关；测定部位桡骨ＢＷ和前臂长度随年龄的增加呈曲线增加。在以身高和体重调整后，性别、年龄和体重对桡骨ＢＷ的影响变得不显著，只有身高的影响显著。本研究证明儿童在０～１６岁范围，身高（而不是肥胖）是骨骼ＢＭＣ的主要决定因素。在比较儿童骨密度结果时，要参考多个变量，如ＢＭＣ、骨密度，ＢＭＣ／体重、ＢＭＣ／年龄等综合评价指标更有说明力。     

Modern day film-screen combinations do not obey conventional exposure rules

Purpose: Following the widespread adoption of energy-dependent rare earth intensifying screens this study investigates the relevance of two conventions (the 10 kVp and kVp-to-the-4th-power rules) commonly used to calculate the kVp/mAs relationship.Methods: A stepwedge was exposed at standard kVp and mAs setting. The kVp was then increased in increments of 5 kVp, and appropriate mAs values were determined using a densitometer. These values were then compared with approximations from the rules previously mentioned.Results: Wide discrepancies are reported between appropriate and approximated values with the latter overestimating exposure by a factor of two.Discussion: Traditional theorems used to estimate the kVp/mAs relationship should no longer be used in modern imaging departments. Each film screen combination should be evaluated individually to ensure appropriate exposure settings.     

长跑运动对老年人尺桡骨密度影响的观察

本文对63名老年长跑运动员及非运动老年人的尺桡骨骨密度进行了测定。结果表明,男性运动组尺、桡骨骨密度及风桡骨骨密度均值比非运动组显著升高,男性运动年限>10年组桡骨骨密度、尺桡骨骨密度均值明显高于运动年限≤10年组,而女性运动组尺桡骨骨密度及尺桡骨骨密度均值与非运动组相比无明显差异。提示,坚持长跑锻炼在预防老年性骨质疏松症中,对男性作用明显,而对女性作用不显著。     

Intermittent etidronate partially prevents bone loss in hirsute hyperandrogenic women treated with GnRH agonist

Treatment with gonadotropin-releasing hormone (GnRH) agonist leads to enhanced bone turnover and accelerated bone loss in premenopausal women with endometriosis, uterine leiomyomatomas and hirsutism. Sodium etidronate is a powerful inhibitor of bone resorption which has been proven efficacious in the prevention and treatment of postmenopausal osteoporosis. The objective of this study was to evaluate the skeletal effects of 6 months of therapy with the depot preparation of the GnRH agonist triptorelin (decapeptil 3.75 mg intramuscularly every 4 weeks) in 24 hirsute patients, aged 24–33 years, with hyperandrogenic chronic anovulation. Ten patients also received cyclical etidronate in an oral dose of 400 mg/day for 2 weeks, followed by an 11-week period of 500 mg/day elemental oral calcium (one cycle). The remaining 14 patients received 500 mg/day of elemental calcium continuously. After 6 months all treatments were discontinued for at least a further 6 months. Bone mineral density (BMD) at lumbar spine and hip (dual-energy X-ray absorptiometry, Sophos LXRA, France) and biochemical markers (serum alkaline phosphatase, osteocalcin, urinary N-telopeptide and hydroxyproline/creatinine ratio) were evaluated at baseline, 6 months and 12 months. In the group given GnRH agonist alone BMD fell significantly at all measured skeletal sites during the first 6 months. In the patients treated with etidronate a significant decrease in BMD was observed at lumbar spine but not in the femoral neck and trochanter, and the changes at lumbar spine and trochanter were significantly smaller than those in the control group. At 6 months bone turnover was also increased in patients treated with GnRH and calcium. Cyclical etidronate prevented the increase in biochemical markers of bone formation and resorption, with the exception of calcium/creatinine excretion, which was significantly increased in both groups. Six months after treatment withdrawal BMD did not recover in either group. Biochemical markers (N-telopeptide, serum alkaline phosphatase) remained increased in those patients previously treated with calcium alone while they remained close to baseline values in the patients treated with cyclical etidronate.Our study indicates that: (1) GnRH agonist therapy causes remarkable bone loss in young individuals with androgen excess who are expected to have increased bone mass; (2) this bone loss can be partially prevented by intermittent cyclical etidronate therapy.     

Improved anchorage in osteoporotic vertebrae with new implant designs.

The goal of our study was to evaluate two newly developed implant designs and their behavior in terms of subsidence in lumbar vertebral bodies under cyclic loading. The new implants were evaluated in two different configurations (two small prototypes vs. one large prototype with similar load-bearing area) in comparison to a conventional screw-based implant (MACS TL). A pool of 13 spines with a total of 65 vertebrae was used to establish five testing groups of similar bone mineral density (BMD) distribution with eight lumbar vertebrae each. In additional to BMD assessment via dual-energy X-ray absorptiometry, cancellous BMD and structural parameters were determined using a new generation in vivo 3D-pQCT. The specimens were loaded sinusoidally in force control at 1 Hz for 1000 cycles at three load levels (100, 200, and 400 N). A survival analysis using the number of cycles until failure (Cox regression with covariates) was applied to reveal differences between implant groups. All new prototype configurations except the large cylinder survived significantly longer than the control group. The number of cycles until failure was significantly correlated with the structural parameter Tb.Sp. and similarly with the cancellous BMD for three of five implants. In both large prototypes the cycle number until failure significantly correlated with the preoperative distance to the upper endplates. Although the direct relationship between bone structure or density and mechanical breakage behavior cannot be conclusively proven, all the prototypes adapted for poor bone structure performed better than the comparable conventional implant.     

急性肺水肿是输液相关性死亡的主要原因

目的探讨输液相关性死亡的病理学特点及死亡原因.方法对1990年～2001年间医疗纠纷尸检档案中28例输液相关性死亡的资料进行分析.结果输液过程中死亡以中老年男性为主,输液相关死亡多发生在基层医疗单位内科性质科室.死亡多发生在输液4 h内,绝大多数患者在临死前有呼吸困难的表现.尸检发现死者大体呈溺死肺样改变,重量增加1～2倍.结论输液引起死亡的原因以急性肺水肿为主,其次为输液过多致动脉瘤破裂.     

Spinal Trabecular Bone Loss and Fracture in American and Japanese Women

This study examined trabecular bone mineral density (BMD) in Japanese women with and without spinal fracture, and compared the results to American women with and without fracture. The quantitative computed tomography (QCT) systems used at the University of California, San Francisco (UCSF) and at Nagasaki University were cross-calibrated. Normative BMD was assessed with the K₂HPO₄ liquid phantom in 538 Americans aged 20–85 years, and with the B-MAS200 phantom in 577 Japanese aged 20–83 years. These BMD were adjusted for use with the Image Analysis solid phantom using the result of cross-calibration. The trabecular BMD in 111 postmenopausal American women (55 with fracture), and in 185 postmenopausal Japanese women (67 with fracture) were compared for investigation of the difference in BMD values relative to fracture status. The absolute BMD values in Japanese were lower than those in Americans, and the differences were greater with advancing age. The magnitude of the BMD difference was 8.6, 20.5, 38.1 mg/cm³ in women aged 20–24 years, 40–44 years, 60–64 years, respectively. In premenopausal women, BMD began to decrease at the age of 20 in Japanese, whereas the peak bone mass was maintained until the age of 35 in the American women. In immediate postmenopausal women, BMD significantly decreased in both populations. In later postmenopausal women, BMD significantly decreased with age in the Japanese women but decreased less rapidly in the American women. The aging decrease of BMD was 1.4% and 2.2% per year in the later postmenopausal American and Japanese women, respectively. The fracture threshold is considered to be lower in Japanese women. However, the BMD difference between American and Japanese women with fracture was similar to that without fracture. The Z-scores of fracture subjects versus controls were 2.9 in American and 1.8 in Japanese women. In conclusion, Japanese women were found to have a lower BMD and lower fracture threshold than American women. The significant decrease of spinal trabecular BMD in late postmenopause is potentially responsible for the higher prevalence of spinal fracture in Japanese women. Received: 18 December 1995 / Accepted: 23 September 1996     

Discrimination of spinal fracture with various bone mineral measurements

For several different bone mineral measurements and various skeletal sites, we compared capability to discriminate between women in various age decades with and without spinal fracture, and attempted to identify the most effective cutoff level in discrimination of spinal fracture. The subjects were 88 women aged 50–59 years (including 32 with fracture), 95 women aged 60–69 years (including 54 with fracture), and 34 women aged 70–79 years (including 18 with fracture). Spinal trabecular and cortical bone mineral density (BMD) were measured using quantitative computed tomography (CT), and spinal, radial (ultra-distal, 10% distal and 33% distal), and calcaneal BMD were measured by dual X-ray absorptiometry. These BMD values were obtained in each subject on the same day. Three statistical techniques—Student's t-test, the logistic regression analysis, and the receiver operating characteristics (ROC) analysis— were applied and accuracy was calculated using the various cutoff values. The capability to discriminate between women with and those without fracture using these BMD values was different among the three age groups. In women aged 50–59 and 60–69 years, all measurements showed good capabilities for discriminating women with fracture. In women aged 70–79 years, these measurements showed lower capability than in those aged 50–59 and 60–69 years, but among them, the calcaneal and ultradistal radial BMD showed relatively good capability. The 10% and 33% distal radial BMD values were not useful in the detection of the high risk women with fracture. The cutoff BMD values for discrimination of women with fracture varied according to the sites and methods of measurement. For each specific age group, the most suitable measurement methods and the appropriate skeletal sites should be considered, and the effective cutoff values to discriminate those with fracture may differ according to the measurement methods, the skeletal sites examined, and age. Received: 5 February 1996 / Accepted: 18 June 1996