Biomedical subjects

M Thiechart

Publications and source records attributed to M Thiechart.

7 recordsLinked to original sources

PubMed2001

Increased vascularization in myeloma.

Several studies have shown that the number of intratumoral vessels can predict the aggressiveness of a solid cancer, development of metastases and patient survival. Does angiogenesis play an important role in myeloma? The aim of our study was to quantify bone marrow vascularity in various stages of proliferative plasma cell disorders (monoclonal gammopathies of undetermined significance (MGUS), stage I multiple myeloma (MM), stage III MM and Waldenström's macroglobulinemia (WM)) and to compare it with that of patients with osteoporosis. The study included 15 MGUS patients, 15 patients with stage I MM, 15 patients with symptomatic stage III MM, 7 patients with WM, 10 patients with osteoporosis, and 10 patients with reactive bone marrow (RBM), matched for sex and age. After iliac crest biopsy, the various vessels (arterioles, capillaries and sinusoids) were labeled with monoclonal antibodies CD34 and counted, and a histomorphometric study was done. The number of arterioles and arterial capillaries was significantly increased in MGUS and myeloma compared with osteoporosis. The number of arterioles and arterial capillaries increased moderately according to the stage of gravity of myeloma. The number of arterioles is negatively correlated with the trabecular bone volume and positively correlated with the eroded surfaces.

Adult↗

PubMed1997

Histological appearance of the intra-osseous vessels of the femoral head in aseptic osteonecrosis of the hip, with or without antiphospholipid antibodies.

UNLABELLED: It has been suggested that in some patients non-traumatic aseptic osteonecrosis of the hip (AOH) could be the result of the intra-osseous thrombosis. Antiphospholipid antibodies (APL) have been associated with venous and arterial occlusive events and the association between AOH and APL syndrome has been reported. OBJECTIVES: To compare bone vessels of the femoral head in patients operated on for AOH with or without APL. PATIENTS: Twenty patients (mean age 47 yrs) with AOH were included: in eight patients APL (IgG-ELISA) were negative (< 8 GPL units), in nine patients APL were doubtful (8-15 GPL units), and in three patients APL were positive (> 15 GPL units). METHODS: Bone vessels were examined: arteriosclerotic lesions, i.e. fibrosis or thickening of the media and rupture of the internal elastic lamina, thrombosis or vasculitis were sought in the femoral heads after total hip replacement or core decompression. RESULTS: Bone vessel lesions were the same in the three groups.

Adult↗

PubMed1996

Effect of ovariectomy on intraosseous vascularization and bone remodelling in rats: action of tiludronate.

In order to study the action of tiludronate on the changes in intraosseous vascularization induced by ovariectomy, and to link these effects to those observed in bone remodelling, 30 female Sprague-Dawley rats (age 40 weeks) were studied. Ten rats were shamoperated and treated by vehicle, 10 rats were ovariectomized and treated by vehicle, and 10 rats were ovariectomized and treated orally with tiludronate, 0.16 mmol/kg/per day, 3 days a week for 16 weeks, from the day following ovariectomy. The rats were killed after 4 months, and a histomorphometric study and quantification of intraosseous vessels carried out on the sixth lumbar vertebra. The area of the intraosseous sinusoidal capillaries increased after ovariectomy, which also induced a moderate increase in resorption surfaces and osteoid surfaces leading to a decrease of 40% in the trabecular bone volume at the lumbar spine level. This bone mineral loss was completely prevented by tiludronate, which normalized the bone turnover. However, tiludronate was without any effect on intraosseous vascularization. These results indicate that the surface area of the intraosseous sinusoidal capillaries was correlated positively with resorption surfaces and negatively with trabecular bone volume and the number of bone trabeculae. In these experimental conditions, an inhibitor of bone resorption can exert its positive effect on bone mass without normalization of vascularization.

Animals↗

PubMed1995

Study of the intraosseous vessels of the femoral head in patients with fractures of the femoral neck or osteoarthritis of the hip.

Bearing in mind earlier studies which established a link between arteriosclerosis and mineral loss, or fragility of the bones, and also our recent study showing that patients with arterial disorders of the lower limbs also suffered from osteoporosis, we carried out a histological study of the number and appearance of the intraosseous vessels and trabecular bone volume in the femoral heads of patients undergoing surgery for either fracture of the femoral neck or osteoarthritis of the hip. The number of thick-walled vessels, arterioles or arterial capillaries was significantly diminished in the femoral heads of patients with fractures of the femoral neck (p = 0.007). In addition, in the latter patients, arteriosclerotic vascular lesions (rupture of the internal elastic lamina, medial thickening and fibrosis) were more frequent than in patients with osteoarthritis of hip. The possibility that, through chronic ischemia, arteriosclerosis may lead to disturbance of bone remodelling and loss of the mechanical properties of bone has not been contradicted by these findings.

Aged↗

PubMed1993

Histopathology of the vessels of the femoral heads in specimens of osteonecrosis, osteoarthritis and algodystrophy.

The authors studied by light microscopy the vessels of the femoral head and neck in 38 well preserved specimens from core biopsy. There were 17 cases of osteonecrosis (ON), 11 cases of osteoarthrosis (OA) and 10 cases of reflex sympathetic dystrophy, so called algodystrophy (AD). Mean age of the patients was respectively 44, 45 and 42 years. The sex ratio, M/F, was respectively 12/5, 6/5 and 9/1. Types of staining used were hematoxylin-eosin, Masson Trichrome, P.A.S. and Verhoeff. In counting, thick-walled and thin-walled vessels were distinguished. There was a significant reduction in the number of the thick- and thin-walled vessels, in the ON group, by comparison with the OA and AD groups. An increased number of thin-walled vessels in the AD group were also observed. Morphological study showed an abnormal frequency of fibrosis of the media in the arteries of the ON group, i.e. arteriosclerosis. These data were compared with the few other histopathological studies previously published. The authors recommend further studies in order to precise their frequency and their significance.

Adult↗

PubMed1987

Experimental post-contusive osteoarthritis of the knee: quantitative microscopic study of the patella and the femoral condyles.

A contusive procedure has been developed for the induction of a predictable and reproducible degenerative joint disease in knees of rabbits. Significant degeneration was observed in patella, condyles, and trochlea. These lesions included fibrillation, ulceration and erosion, clones of chondrocytes, and osteophyte formation. The incidence and distribution of lesions with time following contusion were also investigated. Lesions were observed as early as 1 day post-contusion and increased in number and severity. A global scoring system has been devised to permit comparisons of lesion incidence and severity, specially to test drug efficacy in this model of osteoarthritis.

Animals↗

PubMed1982

[Acute experimental bone marrow necrosis in the rabbit induced by aortic ligation. Ultrastructural and biochemical study].

The authors study the effects of ligation of the infra-renal aorta on the bone marrow in the femoral shafts in ten rabbits, from a histopathological and biochemical standpoint. Histology revealed marrow necrosis in nine cases out of ten. They describe the appearances of this necrosis by light and electron microscopy. In five cases it was focal and partial and in four cases total. It sometimes involved only the haematopoietic tissue, leaving fatty tissue unaffected. The latter would thus seem to be more resistant to ischaemia. Study of lipids showed a decrease in polyunsaturated fatty acids, a decrease which was more marked in the ischaemic femurs than in the humerus of the same rabbits.

Adipose Tissue↗