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101.
Pretreatment of bone with osteoclasts affects phenotypic expression of osteoblast-like cells. 总被引:5,自引:0,他引:5
B D Boyan Z Schwartz C H Lohmann V L Sylvia D L Cochran D D Dean J E Puzas 《Journal of orthopaedic research》2003,21(4):638-647
Implant surface morphology regulates osteoblast phenotypic expression. Osteoblast sensitivity to non-biologic surfaces suggests that native bone surface features may also affect osteoblast response. To test this, MG63 osteoblast-like cells were grown for 7 days on bovine cortical bone wafers pretreated with rat bone marrow osteoclasts for 0, 10 or 20 days. Response to osteoclast-treated surfaces was compared to the response of MG63 cells to titanium surfaces with smooth and rough microtopographies. Cell number, differentiation (alkaline phosphatase activity and osteocalcin levels), and local factors (PGE(2) and TGF-beta1) were measured in confluent cultures. Compared to culture on plastic, cell number was reduced on all three types of bone wafers; this effect was dose-dependent with increasing resorption of the surface. Alkaline phosphatase specific activity was increased (P相似文献
102.
Bruce F. Waller Charles M. Orr James Van Tassel Thomas Peters Edward Fry James Hermiller Larry D. Grider 《Clinical cardiology》1997,20(1):67-74
Catheter balloon angioplasty is a well accepted form of nonsurgical treatment of acutely and chronically obstructed coronary artery vessels. It is also the centerpiece for various new intervention techniques. Their morphologic effect on the site of obstruction has been termed “remodeling.” Part V of this six-part series focuses on remodeling effects of balloon angioplasty on obstructed young (≤ 1 year) and old (> 1 year) saphenous vein bypass grafts. 相似文献
103.
J. Thiele T. K. Zirbes J. Lorenzen H. M. Kvasnicka S. Scholz A. Erdmann U. Flucke V. Diehl R. Fischer 《Annals of hematology》1997,75(1-2):33-39
In order to determine the dynamics of hematopoietic cell turnover, proliferative activity and incidence of apoptosis (programmed
cell death) were evaluated in bone marrow trephine biopsies. Selection of patients (20 in each group) included in addition
to a control group, idiopathic thrombocytopenia (ITP), reactive thrombocytosis (TH), secondary polycythemia-smokers' polyglobuly
(PG), primary (essential-hemorrhagic) thrombocythemia (PTH), polycythemia vera (PV), and finally acute myeloid leukemia (AML).
Apoptosis was demonstrated by the in situ end-labeling technique (ISEL) and proliferative activity by applying the monoclonal
antibody PC10 raised against proliferating cell nuclear antigen (PCNA). To assess dynamic features of hematopoiesis, an index
was calculated consisting of the ratio between PCNA-positive nuclei and the apoptotic cell fraction. This factor was termed
the hematopoietic turnover index (HTI). Morphometric analysis revealed that the HTI was significantly increased in AML and
PV. According to cell culture studies both disorders are characterized by either a prevalent proliferation of the myeloid
or erythroid cell mass. On the other hand, PG, PTH, and TH showed no relevant enhancement of this index in comparison to the
control specimen. In vitro experiment results are in keeping with the finding that PG and PTH are not associated with a significant
expansion of the erythroid lineage (CFU-E). Similar to ITP and TH, in PTH megakaryocyte proliferation (CFU-MEG) is the predominant
feature of cell turnover. Differences between PTH and TH are in line with the reduced in vitro formation of CFU-MEG in the
latter disorder. In conclusion, our in situ study on turnover rates of the bone marrow in various neoplastic and reactive
lesions extends previous experimental data on hematopoietic cell kinetics.
Received: 10 March 1997 / Accepted: 18 May 1997 相似文献
104.
Bone mineral density in patients with prostatic cancer treated with orchidectomy and with estrogens 总被引:7,自引:0,他引:7
Bone mineral density (BMD) and bone mineral content (BMC) were measured in the femoral neck area, trochanteric area and Wards triangle, and in the distal radius of the left forearm before and after 1 year of endocrine treatment in 27 patients with prostatic cancer. Eleven of the patients were treated with orchidectomy and 16 with combined oral and intramuscular estrogens. The patients were free from metastases during the entire observation period. In the orchidectomized patients, BMD and BMC of the distal radius decreased significantly following treatment, whereas no changes were observed in the estrogen-treated patients. These preliminary results demonstrate that estrogens may protect bone in male subjects also and may merit further investigations on larger groups of patients. 相似文献
105.
106.
Hiroshi Uno Yoshihiro Izawa Kiyoshi Sagara Tamotsu Koyama Tokutaro Makita Chia-Yuan Hsu-Chang Mitsugi Sugiyama 《Journal of bone and mineral metabolism》1990,8(1):10-16
The effect of 1α-hydroxyvitamin D3 (1α(OH)D3) on the metabolic bone disorders developed in gastrectomized rats were investigated biochemically and histomorphologically.
1α(OH)D3 was suspended in 0.2 % Triton-X-100 aqueous solution after dissolving in a very small amount of ethanol, was given orally
to the rats for 10 weeks. The sham operated animals and the gastrectomy control animals received the vehicle alone. Gastrectomy
was followed by the development of the metabolic bone disorders after 10 weeks of observation. This was characterized by reduction
in ash content of the femur and histologically by a disappearance of the trabecular bone in tibial metaphysis. Decrease Ca
absorption from the intestines was demonstrated by a radiotracer technique. Biochemical studies showed significant decreases
in serum 25(OH)D concentration in gastrectomized rats. These findings suggest that gastrectomy partially impairs intestinal
absorption of calcium and results in a negative calcium balance, which may contribute to the development of bone metabolic
disorders in rats. The administration of 1α(OH)D3 increased dose-dependently serum calcium and Ca absorption from the intestine and prevented the development of bone metabolic
disorders histomorphologically. 相似文献
107.
C. Schwartz A. Raye R. Petit 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》1997,7(2):115-118
Summary 51 cases of repeat hip replacement have been reviewed, using allografts for acetabular bone loss, stages 2 and 3 (27 lyophilised and 24 deep-frozen). Mean follow-up was 4 years. Loosening was the reason for intervention; 14% of cases were septic. Massive grafts were used in 75% of cases and smaller grafts in 25% of cases. In addition a reinforcement ring was necessary in 75% of cases. Merle d'Aubigné's rating scale was used to assess results. The radiologic assessment score was that of Gross and De Lee.There was no difference between lyophilised and deep-frozen grafts. Clinical scores found 55% of excellent results; 11% were poor, the rest were good or fair. Stability was more troublesome than pain. Radiologic screening showed union between graft and host in 53% of cases but in 41% there was incomplete fusion. In the non-weight-bearing area bone lysis appeared in 14 cases out of 20. Five cases were complete failures; four of these were infected and were reoperated, the bone-graft acting as a foreign body.To date, we have no better bone replacement material than allografts. Fixation of the graft must be secure. An infected hip is not a good indication for this type of operation. Clinical results are satisfactory in more than 80% of cases, although 40% of grafts seem to be incompletely integrated. 相似文献
108.
Mentosternal contractures still represent a surgical challenge due to their prominent position. They require early operative treatment for both function and aesthetic reasons. Careful clinical examination of scar position and traction forces, both at rest and when functioning, in addition to proper evaluation of the surrounding soft tissue are mandatory for precise preoperative planning of the required reconstruction. In general, the technically most feasible operation is favored if the functional and aesthetic results are good and postoperative risk for recurrence is low. Between 1987 and 1994, 21 patients with cervical, mentosternal, and mentothoracic contractures were operated upon. Eight patients were reconstructed with local flaps and 13 with microvascular free flaps. 相似文献
109.
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 相似文献
110.
I. Gorai Y. Taguchi O. Chaki M. Nakayama H. Minaguchi 《Calcified tissue international》1997,60(4):317-322
Urinary excretion of cross-linked N-telopeptide of type I collagen (NTx) has been reported to be a specific marker of bone
resorption [18]. We assessed a new immunoassay for NTx as an indicator of changes in bone resorption caused by spontaneous
menopause and compared cross-sectionally the levels of urinary NTx, hydroxylysylpyridinoline (HP), lysylpyridinoline (LP),
hydroxyproline (OH-Pr), other serum biochemical indices, and lumbar spine and proximal femur bone mineral density (BMD). Eighty-one
Japanese women aged 22–77 participated in this study; 36 were premenopausal and 45 were postmenopausal. Urinary HP, LP, and
NTx stayed at low levels in the premenopausal period and rose 21%, 30%, and 67% in the postmenopausal period, respectively.
The rise in LP and NTx was statistically significant (P < 0.01), suggesting that NTx is mostly released from bone matrix when bone resorption is accelerated. When premenopausal
women were divided into two age groups and postmenopausal women were divided into two groups according to years since menopause
(YSM) there were significant differences in LP and NTx between women <4 YSM and women aged <40 and those women aged 41+ (P < 0.01 and P < 0.05, respectively). A significant 110% increase in urinary NTx and a 48% increase in urinary LP were observed in postmenopausal
women compared with age-matched premenopausal women aged 45–55. All biochemical markers other than serum PTH correlated significantly
with each other (r = 0.243–0.858, P < 0.05–0.0001). Urinary NTx inversely correlated with lumbar spine BMD. When postmenopausal women were divided into three
groups, the correlation between bone resorption and formation markers in women 0-1 YSM was greater than in women 2–10 YSM
and in women 11 + YSM, indicating that resorption and formation are coupled at the early postmenopausal period. We conclude
that urinary NTx is responsive to changes in bone metabolism caused by estrogen deficiency and may be a more sensitive and
specific marker than HP, LP, or OH-Pr in the early postmenopausal years.
Received: 15 February 1995 / Accepted: 18 October 1996 相似文献