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71.
Summary It is generally accepted that osteoclasts are responsible for the breakdown and removal of bone matrix constituents. However,
very little is known about the fate of osteocytes during bone resorption. In the present study we have examined sites of bone
destruction in calvaria of young rats aged 4–9 days in the hope of obtaining information on the fate of osteocytes. Decalcified
glutaraldehyde-formaldehyde-fixed specimens were prepared for ultrathin section electron microscopy. When sequentially arranged,
the images obtained suggest that osteoclasts engulf and destroy osteocytes during bone degradation. We propose that the following
sequence of events takes place when a lacuna is opened up by an osteoclast: (1) When the osteoclast comes in contact with
an osteocyte, the villi of the ruffled border become flat and broad. (2) Long osteoclastic extensions surround the osteocyte.
(3) The osteocyte is subsequently internalized with apparent degradation. 相似文献
72.
E. I. Barengolts M. Berman S. C. Kukreja T. Kouznetsova C. Lin E. V. Chomka 《Calcified tissue international》1998,62(3):209-213
Estrogen deficiency is a risk factor for osteoporosis and coronary artery disease. Osteoporosis can be evaluated by measuring
bone mineral density (BMD). Coronary atherosclerotic burden can be evaluated by measuring coronary calcium using electron
beam computed tomography (EBT) of the heart. We compared coronary calcium scores in 45 asymptomatic postmenopausal women with
normal and low BMD. BMD of the lumbar spine and proximal femur was measured by dual X-ray absorptiometry (DXA), and coronary
calcium was measured quantitatively by EBT. Women were divided into control, osteopenia, and osteoporosis groups based on
the T score of the lumbar spine. Women were similar in age, years since menopause, height, weight, and body mass index (BMI).
BMD ± SD (g/cm2) of L1–L4 was 0.96 ± 0.11, 0.83 ± 0.03, and 0.73 ± 0.05, in control, osteopenia, and osteoporosis group, respectively. The
total coronary calcium score ± SD (relative units) was 41.9 ± 83.1, 115.1 ± 181.9, and 221.7 ± 355.4 for control, osteopenia,
and osteoporosis group, respectively; the score was significantly higher in the osteoporosis than in the control group. This
study provides initial data suggesting that women with osteoporosis may have a higher risk of developing coronary atherosclerosis. 相似文献
73.
小儿先天性髋关节脱位近年来应用术式的演变及其评估 总被引:5,自引:2,他引:3
本文介绍本院近4年来小儿先天性髋脱位治疗应用术式的演变。由20多年来一直喜欢用骨盆截骨术演变为近1年来用得最多的是造盖术。近4年共手术463例,565髋。实践证明:比起骨盆截骨术,造盖术显得更简便,侵袭小,不需二次手术拔除内固定针。因在我国大龄髋脱位偏多,造盖术更适合我国国情。经过一些改进,可以克服造盖折断和吸收问题。 相似文献
74.
P. Rokkanen O. Böstman E. Hirvensalo E. A. Mäkelä E. Partio H. Pätiälä S. Vainionpää K. Vihtonen P. Törmälä 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》1992,2(2):107-110
Résumé L'utilisation de matériaux d'ostéosynthèse biodégradables a l'avantage d'éviter la réintervention pour extraire le matériel. Les biomatériaux de polymères polyglycolides ont été expérimentés sur plus de 3 600 animaux de laboratoire avant leur introduction en pratique clinique. Depuis 1984 nous les avons utilisés comme matériau d'ostéosynthèse dans près de 1 700 cas parmi lesquels 880 cas de fracture malléolaire, 226 cas d'ostéotomie en chevron pour hallux valgus, 65 cas de fracture de la tête radiale et 54 cas de fracture de l'olécrane. Parmi les 800 premiers cas traités par broches biodégradables nous avons obtenu des résultats favorables et sans incidents dans 91 pour cent des cas. Il y eut 7 cas de fixation défaillante nécessitant une réintervention. Il y a eu 7 cas d'infection superficielle et 3 cas d'infection profonde. Nous avons observé la formation d'une collection séreuse sous-cutanée sans influence sur le résultat radiologique ou clinique dans 52 cas (6,5 %). Au vue de ces résultats et compte tenu des avantages économiques et psychologiques des matériaux biodégradables (pas de réintervention), on peut penser que l'usage de biomatériaux rivalise favorablement avec l'usage de matériaux conventionnels dans certains types d'ostéosynthèse.
Utilization of biodegradable implants in the surgical treatment of fractures and osteotomies
Summary The utilization of biodegradable implants instead of metals in orthopaedic surgery abolishes the need to remove the fixation material. For this study biodegradable rods and screws of self-reinforced polyglycolide, polylactide and lactide-glycolide copolymer were developed and manufactured. The clinical introduction of these implants was preceded by thorough experimental studies with 3 600 animals. From November 1984 the developed biodegradable method of osteofixation was used in 1 700 operations. These included 880 displaced malleolar fractures, 226 chevron-osteotomy for hallux valgus, 65 displaced fracture of the radial head, 54 displaced frature of the olecranon and other fresh fractures or orthopaedic operations. In the first 800 cases operated on using self-reinforced polyglycolide rods the postoperative course was uneventful (91%). Because of failure in the fixation reoperation was needed in 7 cases. A superficial wound infection was observed in 7 cases, deep infection in 3 and transient fluid accumulation in 52 cases (6,5%). Fluid accumulation did not influence the radiological or clinical end-result. The advantages of biodegradable fixation are many-sided. There is a costbenefit and clinical capacity is free for other use, and psychological advantages must be emphasised because removal of implants is not needed. The over all results of this study were considered favourable.相似文献
75.
Clanton C. Shipp Paul S. Berger Manya S. Deehr Bess Dawson-Hughes M.D. 《Calcified tissue international》1988,42(5):287-292
Summary Precision of dual-photon absorptiometry (DPA) measurements was determined in a lumbar spine phantom and in humans. Approximately
half of the measurements were made before and half after a153gadolinium source change. The phantom was measured with different amounts of acrylic, which simulates human soft tissue, in
order to evaluate the influence of body thickness on bone mineral density (BMD). Results of scans analyzed with two software
versions from Lunar Radiation Corp., the widely used 08B and a prototype 08C, are compared. DPA with a cold source significantly
overestimated BMD in the phantom in the presence of large amounts (more than 25 cm) of soft tissue equivalent with version
08B but not with the newer version 08C. Similiarly, in nine subjects, there was a significant decrease in spine BMD after
a source change when scans were analyzed with version 08B (mean difference 0.026 g/cm2,P=0.002) but not with 08C (0.01 g/cm2,P=0.234). No systematic effect of source change on femoral BMD measurements was observed. The SD of the mean difference of
two measurements of the nine subjects was 0.019 g/cm2 (1.6% of the mean value) for the spine with software version 08B and 0.024 g/cm2 (2.0%) with version 08C, 0.03 g/cm2 (3.3%) for the femur neck, 0.03 g/cm2 (4.0%) for the greater trochanter, and 0.04 g/cm2 (4.9%) for Ward's triangle region of the proximal femur. The spine phanton was scanned on two other commercial bone densitometers
in order to assess inter-instrument variation. Phantom measurements of L2-4 BMD made on two Lunar Radiation Corp model DP3
scanners which differed by 2% were 10 and 12% higher than those with a Norland Corp. model 2600 scanner. 相似文献
76.
N. Glajchen S. Thomas P. Jowell S. Epstein M.D. F. Ismail M. Fallon 《Calcified tissue international》1990,46(1):28-32
Summary The paucity of information on the effect of long-term high-dose salmon calcitonin administration on normal bone mineral metabolism
and histology prompted an investigation of the influence of high-dose synthetic calcitonin in the rat. Serum ionized calcium,
osteocalcin or BGP (bone gla protein), and immunoreactive PTH were measured serially during calcitonin administration and
bone histomorphometry analyzed at 6 weeks (after sacrifice). Daily injections of salmon calcitonin, 0.4 IU/100 g (group B)
and 2 IU/100 g (group C), resulted in significant hypocalcemia at 4 hours for both experimental groups (P<0.004). Serium iPTH was significantly higher over the study period for both groups administered calcitonin. Serum BGP levels
were significantly lower than controls during the study in group C (P<0.002) and to a lesser extent in group B (P<0.05). In group C, bone histomorphometry revealed increased resorption (onteoclast count), decreased trabecular bone volume,
and decreased double-labeled tetracycline surface (bone formation). In group B an increase in osteoclast count but no alteration
in bone formation was observed. To assess the role of PTH in the above findings, high-dose calcitonin was administered to
parathyroidectomized rats. All of the above changes in bone histomorphometry were not observed in this group of animals. In
conclusion, high doses of calcitonin promote hypocalcemia, secondary hyperparathyroidism, and osteoclastosis in the normal
rat in a dose-dependent manner with very high-dose calcitonin impairing bone formation. 相似文献
77.
目的探讨前列腺素E1(PGE1)应用于尸体肾移植术后肾功能延迟恢复(DGF)患者对移植肾功能恢复的影响.方法回顾性分析因急性排斥(AR)和急性肾小管坏死(ANT)导致DGF的127例临床资料,其中应用PGE1治疗56例(PGE1组),未用PGE1者71例(对照组).比较两组在出现DGF后的透析治疗时间、肾功能恢复情况、彩超的移植肾血流阻力指数(RI)及6个月内AR发生率.结果与对照组比较,PGE1组透析治疗时间明显缩短(P<0.05),移植肾的血肌酐下降速度快(P<0.05),RI及6个月内AR发生率低(P<0.05).结论PGE1有利于尸体肾移植术后DGF患者移植肾功能的早期恢复,并能降低AR的发生率. 相似文献
78.
目的:运用药物经济学的方法对在我院应用的6种中药注射液进行成本-效果分析。方法:271例急性脑梗死患者依据药物治疗方案不同分为6组,即血塞通组、舒血宁组、苦碟子组、疏血通组、川芎嗪组、丹红组,分别观察疗效,并运用药物经济学的方法进行成本-效果分析。结果:疏血通组的成本为3 419.90元,总有效率最高(91.84%),6组间增量成本-效果最低。因此疏血通组是较为合理、经济的方案。 相似文献
79.
关于中医证候研究的几点想法 总被引:21,自引:5,他引:16
中医证候学研究是目前中医药研究工作的前沿领域.近年来,虽从不同的角度取得了一些进展,但就本质而言,依旧没有明显的突破.虽然证候的传统定义是基本清楚的,但证候的宏观(定性)标准不十分规范,证候宏观(定性)标准量化研究方法有待统一.这在很大程度上阻碍了整个中医药现代化的进程,因此,证候的现代研究思路值得进一步探讨.在证候研究过程中,建议:(1)以现代疾病为切入点,从基本证候(单证)着手,逐步向复证研究过渡;(2)以人为研究对象,取得相当成果后再进行动物实验才有意义;(3)不仅要与生命科学接轨,更要与整个的自然科学接轨. 相似文献
80.
中西医结合要为妇女生殖健康创新页 总被引:7,自引:1,他引:6
45年来,复旦大学妇产科医院在中西医结合临床及科研方面取得了可喜的成就.针刺促排卵的研究,通过观察血雌激素和中枢β-内啡肽(β-EP)的关系,提出了针刺通过耗竭中枢β-EP而促排卵的新认识,认为针刺促排卵的主要适应症是青春期月经失调,并将针刺成功地应用于治疗神经性厌食;补肾化痰的俞氏温补方治疗多囊卵巢综合征(polycystic ovary syndrome, PCOS)被证实是通过提高血促卵泡激素(follicle stimulating hormone, FSH)并诱发排卵而起作用;益肾化瘀的天癸方是通过降低患者及动物模型的雄激素和胰岛素,引起以中枢阿片促黑激素皮质素原、神经肽Y和瘦素受体为主的神经-内分泌-代谢网络调节而发挥促排卵和减肥作用,对高胰岛素型PCOS有良效,并在研究中提出了对PCOS分类的新设想;益肾清火的更年春通过提高中枢与周围组织的雌激素受体及其mRNA表达来调节围绝经期妇女的神经-内分泌-免疫-代谢网络而获优越疗效.这些研究表明,疾病是外环境影响下患者生命网络的某些主脉失调所致,而且亚健康状态的妇女具有初步网络失控的现象,中西医结合将为女性生殖医学研究找到捷径,调控生命网络是防病治病的主要思路. 相似文献