Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The assumption that a change in interstitial bone thickness reflects a converse change in resorption depth was recently found to be incorrect. Accordingly, we re-examined previously published data concerning trabecular thickness and wall thickness in 15 patients with nonosteomalacic osteopenia following intestinal bypass surgery for obesity. The average number of remodeling cycles completed since the operation was calculated according to two assumptions: First, that the measured activation frequency had been present since the operation; second, that activation frequency had increased in the first two years after operation because of secondary hyperparathyroidism. In comparison with mean wall thickness in 40 normal subjects (38.6 microns), resorption depth calculated in accordance with the first assumption was significantly increased (54.1 microns; p less than 0.001), but calculated in accordance with the second assumption was unchanged (42.1 microns; NS). Reasons are given for believing that the second assumption is more likely to be correct than the first. Mean trabecular thickness and mean wall thickness were significantly correlated (r = 0.68; p less than 0.005). We conclude: 1) Mean resorption depth cannot be inferred from interstitial bone thickness, but can be calculated if the number of remodeling cycles corresponding to the observed structural changes is known. 2) Even though interstitial bone thickness is reduced, trabecular thinning following intestinal bypass surgery is mainly due to decreased wall thickness, as the result of defects in the recruitment and/or function of osteoblasts. The same probably applies to cancellous osteopenia in various other gastrointestinal and hepatobiliary disorders. 3) The study of intestinal bone disease may shed light on the pathogenesis of other, more common, forms of osteoporosis.
 ...
PMID:The ambiguity of interstitial bone thickness: a new approach to the mechanism of trabecular thinning. 206 39

The architecture of cancellous bone as well as quantity and quality is considered important in maintaining mechanical integrity. To determine whether abnormalities of architecture occur in femoral neck fracture we measured trabecular width and number in iliac crest bone biopsies of 68 women with femoral fracture and compared them with data from a postmortem series of age-matched women without known bone disease. Cortical thickness was measured in 27 of the fracture patients and 17 controls. After exclusion of ten biopsies with increased osteoid surface no significant difference was seen in mean trabecular width or number between fracture patients and subjects without fracture. Both thinning of trabeculae and loss of trabeculae contributed to low bone volume in femoral fracture patients. Direct measurements of trabecular number correlated with calculated mean trabecular plate density (P less than 0.001), and the percentage of trabeculae at any one of a range of trabecular widths in the fracture biopsies was similar to that in non-fracture subjects. No difference was seen in the architecture of cancellous bone with age, fracture trauma or between subcapital and intertrochanteric fracture in fracture subjects. Cortical thickness, however, was related to age in both fracture and control subjects (P less than 0.05). There was no difference in cortical thickness between age-matched fracture and control subjects. Patients with intertrochanteric fracture had lower cortical thickness (P less than 0.02) and were older (P less than 0.01) than patients with subcapital fracture.
 ...
PMID:The architecture of cancellous and cortical bone in femoral neck fracture. 208 84

To study the pathophysiology of bone disorder after gastrectomy, 320 patients and 40 Wistar male rats were used. Clinically, patients who had received gastrectomy 1-15 years previously, were examined for skeletal symptoms, serum biochemistry, microdensitometry of second metacarpal bone, and 20 of them were then studied in a calcium infusion test. Using microdensitometry, abnormality of bone metabolism was observed in 38% of the patients. In severe cases, a significant decrease of serum Ca. and increase of alkaline phosphatase were observed (p less than 0.05), 65% complained of joint pain. In the calcium infusion test, severe cases showed a low urinary excretion of Ca, like osteomalacia, and unlike osteoporosis. Experimentally, body weight & amount of food intake decreased and fatty diarrhea was observed in rats after total gastrectomy. Skeletal changes including thinning of the cortex, loss of medullary trabeculation & decrease of bone ash and biochemical changes such as low serum Ca. 25(OH)D3, 24, 25(OH)2D3 and high iPTH levels were observed. Also the bone formation rate was lower than control as detected by tetracycline double labelling method. As low food intake & fatty diarrhea after gastrectomy which result in Ca. & vit. D insufficiency may be the major etiology of bone disorder.
 ...
PMID:[Bone disorder after gastrectomy--clinical & experimental studies]. 226 41

Thinning of the upper cortex of the clavicle, measured on a standard chest radiograph, may help in the diagnosis of osteoporosis. No precise level at which osteoporosis occurs can be given, but a reading of 1.5 mm. or under is indicative of osteoporosis, while a smaller incidence is associated with readings of 2 mm. and above. There is significant correlation between thinning of the clavicular cortex and other radiological indications of osteoporosis. Thinning may occasionally point to unsuspected bone disease, in osteomalacia as well as in osteoporosis. As chest radiographs are taken in a high proportion of both outpatients and inpatients, the method has a wide applicability.
 ...
PMID:Width of clavicular cortex in osteoporosis. 576 59

We report a boy with unusual facial appearance, melanotic patches ("coast-of-Maine" type), myelofibrosis, recurrent femoral fractures, and widespread fibrous dysplasia of bone. Biochemical findings included raised serum alkaline phosphatase (bone isozyme) and 1,25-(OH)2 vitamin D, and low serum phosphorus levels. Elevated urinary excretion rates of total hydroxyproline, glycylproline, and gamma-carboxyglutamic acid indicated increased turnover of bone matrix. Transiliac bone biopsy showed a dearth of marrow elements, greatly increased bone turnover, and absence of normal trabecular organization. Serial radiographs showed progressive cortical thinning and loss of bony trabeculae. Calcitonin and etidronate treatments had no lasting effect on the progressive bone disease. The term "panostotic fibrous dysplasia" is suggested for this condition.
 ...
PMID:Panostotic fibrous dysplasia: a congenital disorder of bone with unusual facial appearance, bone fragility, hyperphosphatasemia, and hypophosphatemia. 684 3

A study was carried out to analyze the pattern of the age related bone loss in the mandibular cortex and to establish normal values and the observed range of morphometric variables on microradiograms of bone sections taken from a well defined site anterior to and below the mental foramen. Specimens were obtained from 100 Danish subjects with no known systemic bone disease or severe mandibular atrophy. Microradiograms of 100-micron-thin undemineralized vertical ground cross-sections were produced. An electric point-counting system was used for the determination of 1) percentage bone mass, 2) mean cortical width (MCW), and 3) the percentage of Haversian canals with resorption surfaces. The analysis showed that cortical porosity and the percentage of Haversian canals showing resorption are unrelated to sex and increased after the age of 50. MCW and absolute bone mass (MCW x % bone mass) are greater in males than in females and show a parallel age related decrease after the age of 50. Furthermore, the age related increase in cortical thinning and porosity is dependent on the individual as well as on age. Marked individual variation confined the use of these parameters to group analysis.
 ...
PMID:Pattern of age related bone loss in mandibles. 692 61

The aims of this review on the use of skeletal surveys in the radiological assessment of renal osteodystrophy were threefold: to describe the radiological pattern of renal osteodystrophy in a local cohort of patients with chronic renal failure, to assess whether serial radiographs of the hands may effectively replace full radiological skeletal surveys in the long-term follow-up assessment of renal bone disease, and to formulate a grading system for bone resorption due to hyperparathyroidism. A radiological study of 61 patients with chronic renal failure revealed 20 (32.8%) patients with unequivocal radiological signs of renal osteodystrophy. The main abnormal radiological features observed in descending order of frequency were: osteopenia with associated cortical thinning and coarsened bone trabecular pattern (75%), subperiosteal resorption (60%), osteosclerosis (50%), extraosseous calcification (30%) and periosteal new bone formation (15%). A five-grade method of assessing the severity and extent of bone resorption was formulated. The study showed that 40% of the patients with a radiological diagnosis of renal osteodystrophy did not show changes in the hand radiographs. This finding precluded a recommendation of hand radiographs being used alone in the long-term radiological follow-up of patients with renal bone disease. An alternative was proposed and this was a limited radiological skeletal survey of three projections: radiographs of both hands, chest including the clavicles and the pelvis. This limited study would result in a cost saving of 62% as compared to a full study.
 ...
PMID:Use of skeletal surveys in the radiological assessment of renal osteodystrophy--a study in the Singapore General Hospital. 826 51

To characterize the magnitude and location of mineralized bone loss, 40 patients (20 men, 20 women, 29 white, 11 black) with clinically significant renal osteodystrophy who could be unambiguously classified based on histologic criteria as having osteitis fibrosa (OF; 20 cases) or osteomalacia (OM; 20 cases) were studied; they had been on maintenance hemodialysis for 4.6 +/- 3.0 yr. One hundred forty-two healthy women of similar age and ethnic composition served as control subjects. In all subjects, the proportions of mineralized bone, osteoid, and porosity (nonbone soft tissue) were measured separately in cortical and cancellous bone tissue, from intact full-thickness biopsies of the ilium, representative of the axial skeleton. The results were related to the volumes of cortical and cancellous bone tissue separately and to the volume of the entire biopsy core. Approximately three-quarters of the patients had measurements in the appendicular skeleton by single photon absorptiometry of the radius and morphometry of the metacarpal. Disease effects did not differ significantly between ethnic groups. Mineralized cortical bone volume (per unit of core volume) was reduced by approximately 45% in both patient groups. Mineralized cancellous bone volume was significantly increased by 36% in the patients with OF and nonsignificantly reduced by 9% in the patients with OM; however, the reduction in the latter patients was significant in relation to tissue volume. The combined total deficit for both types of iliac bone was approximately 20% in the patients with OF and approximately 40% in the patients with OM. Significant reductions in appendicular cortical bone were demonstrated in both patient groups at both measurement sites. Regardless of the current histologic classification, the major structural abnormality in the skeleton is generalized thinning of cortical bone due to increased net endocortical resorption, the most characteristic effect on bone of hyperparathyroidism. Protection of the skeleton from the adverse consequences of renal failure will require therapeutic intervention in patients with no symptoms of either renal or bone disease.
 ...
PMID:Mineralized bone loss at different sites in dialysis patients: implications for prevention. 964 32

The pattern of bone fractures secondary to nutritional bone disease in 38 dogs was analysed using a radiographic survey. The majority of fractures were either caused by a fall (28.95%) or showed no history of direct trauma (31.58%). Mongrels were more commonly affected by pathological fractures, followed by Dobermanns and German Shepherds. Significantly more (P < 0.05) fractures were found in dogs aged less than 6 months (64.71%). The incidence of such fractures was significantly higher in males than in females (M:F = 2.70:1.00). General radiological signs included a generalized decrease in cortical density, thinning of cortices and widening of metaphyses/epiphyses in most of the animals. Fractures were found significantly more frequently (P < 0.01) in the femur (81.58%) than in any other bone. Of the different types of fracture, complete oblique and incomplete fractures were most common.
 ...
PMID:Fractures secondary to nutritional bone disease in dogs: a review of 38 cases. 1059 87

Bone is one of the most common sites of breast cancer metastasis. Metastases are often associated with bone destruction and are a major cause of morbidity. We examined structural bone changes induced by metastatic tumor in bone biopsies from 33 patients with metastatic breast carcinoma (20 from patients with pathological femoral fracture and 13 with no fracture) and 20 normal controls. In all metastatic biopsies bone remodeling was shown to be tumor volume-dependent. Bone resorption and bone formation were biphasic with both increasing at earlier stages of metastatic bone disease and decreasing later on. A comparison of patients with fracture and no fracture did not reveal statistically significant differences in the extent of bone destruction or trabecular thinning. Bone histomorphometry showed limited ability to explain the higher bone volume loss in fracture patients (decreases of 42% and 25%, respectively, in fracture and nonfracture patients compared with controls). However, changes in bone quality, including increased disconnectivity and decreased connectivity, as evaluated by node-strut analysis, suggested that there were more structural changes in the fracture compared with the nonfracture group. The nonfracture group included six patients with no radiological evidence of bone metastasis (occult metastasis). They showed a higher tumor volume and a twofold lower eroded surface compared with the rest of the group. The decrease in bone volume (14% lower than controls) was below the limit of X-ray detection. Because we observed no increase in osteoclast-related parameters and no correlation between osteoclast surface and eroded surface, we believe that, in occult metastasis, osteoclastic bone resorption is not an important factor in overall bone resorption. Quantitatively, the eroded surface in direct contact with tumor cells was threefold higher than the osteoclast surface in occult metastasis, whereas the rest of the metastatic group (27 of 33) showed predominantly osteoclast-mediated eroded surface. Node-strut analysis on occult metastasis revealed a significant increase in disconnectivity without a concomitant significant decrease in bone volume and trabecular thinning. We conclude that, in occult metastasis, bone resorption may be more osteoclast-independent and other mechanisms involving the tumor cells may be more prevalent.
 ...
PMID:Morphological, histomorphometric, and microstructural alterations in human bone metastasis from breast carcinoma. 1239 51


1 2 3 Next >>