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Biomedical subjects

C A Baud

Publications and source records attributed to C A Baud.

At least 37 records · Page 2Linked to original sources
PubMed1986

Ammonium urate urinary stones.

Until the last century, ammonium urate stones were quite common in preindustrial Europe. In contemporary practice these stones are found in developing countries, and are associated with uric acid and ammonium-enriched urine. Such conditions may occur with urealytic infection, resulting in mixed ammonium urate/magnesium ammonium phosphate precipitates and urinary phosphate deficiency of alimentary origin, resulting in precipitates free of magnesium ammonium phosphate, in sterile urine. The latter situation is closely related to a diet poor in phosphate and to a low fluid intake common in endemic lithiasis areas. Ammonium urate and uric acid have different solubility patterns dependent on pH, and consequently treatment will be different in each case.

Adult↗
PubMed1986

[Histomorphometric profile of bone fluorosis induced by prolonged ingestion of Vichy Saint-Yorre water. Comparison with bone fluorine levels].

Nine transiliac bone biopsies from 7 patients with skeletal fluorosis due to prolonged ingestion of often high quantities of Vichy Saint-Yorre water were analyzed. Four of these patients also suffered from a chronic renal failure. A histomorphometric study was possible in 8 out of the 9 biopsies. The measurement of bone fluoride content, and a microradiographic examination, were performed on all bone samples. The radiologically evident osteosclerosis observed in each patient was confirmed by the significant increase of trabecular bone volume. Furthermore, the osteoid surfaces were very extended but the thickness of osteoid seams was normal in 6 out of 8 cases. Two biopsies demonstrated a morphological evidence of osteomalacia with abnormally thick osteoid seams. Calcification rate, measured in one of these 2 cases after tetracycline double labeling, was extremely low (less than 0.20 micron/d). The bone fluoride content was significantly high in each specimen (greater than 0.40 bone ash%) and correlated with relative osteoid volume (r' = 0.91) and thickness index of osteoid seams (r' = 0.83). Histologically, bone tissue showed modifications classically reported in the various types of skeletal fluorosis (formation defects, mottled bone with mottled periosteocytic lacunae). In conclusion, the prolonged administration of Vichy Saint-Yorre water containing 8.5 mg of fluoride ion per liter, provokes a skeletal fluorosis. This intoxication appeared very quickly if the patient suffered from an even mild renal failure. Once again, it is shown that a disturbed renal function predisposes to an excessive retention of fluoride.

Adult↗
PubMed1985

[Multidisciplinary study of the prolonged treatment of involution osteoporosis using sodium fluoride with calcium, phosphate and vitamin D].

A multidisciplinary study on the prolonged treatment of involution osteoporosis with fluoride was performed on a homogeneous population of 31 women aged 51 to 75 years (mean 64 years). The selection criteria were the following: significant backache, vertebral compression fractures on X-rays, bone biopsy evidence of osteoporosis, and absence of other risk factors after a complete workup. The patients were treated for a period of 3 to 6 years (mean 4 years) with daily doses of 30 mg (10 mg 3 times) fluorides ion associated during the last 3 years with 500 mg calcium twice daily, 750 mg phosphate and 1000 units vitamin D daily. The study demonstrated a favourable effect of the treatment on the backache and that it was well tolerated in the majority of cases, the side effects being intermittent osteo-articular pains of the lower extremities due to the fluoride in 9 patients, and gastric intolerance to the phosphate in 7. X-ray follow-up showed slowing of the vertebral compressions after the first year of treatment, but no effect on fractures of the extremities. There was no evidence of alterations in parameters of mineral and bone metabolism, and in endocrine, hepatic, renal or hematological assays. Histomorphometric and biophysical examination of biopsies indicated that, although there was no significant increase in the quantity of mineralized bone under the treatment, there was a very significant improvement in the crystallinity of the mineral substance, thus enhancing the quality of the bone tissue and its resistance to pressure. This study is the first in which a catamnesis of the patients was undertaken, 28 of them having received a clinical and radiological examination 2 years after the end of therapy: a favourable evolution was observed in most of the cases, both in those patients treated for a period of 3 years and in those whose treatment had lasted for a longer period.

Aged↗
PubMed1985

Distribution of fluoride in calcified cartilage of a fluoride-treated osteoporotic patient.

Subchondral bone and calcified cartilage from a femoral head of a 74-year-old osteoporotic woman treated for 30 months with sodium fluoride were analyzed. The fluoride content of the calcified tissues was determined by a specific ion electrode, and the topographic distribution pattern of fluoride was determined with an electron microprobe. The fluoride content in calcified cartilage (0.39% of ash) was higher than in neighboring subchondral bone (0.28% of ash). Line scan and X-ray images indicated a high concentration of fluoride in the outer layer of calcified cartilage lining the uncalcified cartilage, as well as in the inner layer of the subcortical endosteal bone. This study shows that calcified cartilage is an important site of fluoride deposition, and suggests that the accumulation of fluoride is related to the calcification process.

Aged↗
PubMed1983

Bilateral fractures of femoral neck in patients with moderate renal failure receiving fluoride for spinal osteoporosis.

Two patients with moderate renal failure sustained spontaneous bilateral hip fractures during treatment with fluoride, calcium, and vitamin D for osteoporosis. They had been taking sodium fluoride (40-60 mg/day) for 11 and 21 months, respectively. Histological examination of a specimen of the bone showed severe fluorosis in the first case, and quantitative analysis of bone showed osteomalacia and skeletal fluorosis in the other case. These abnormalities were considered to be the consequence of excessive retention of fluoride due to renal insufficiency. As bilateral femoral neck fractures are very rare these data suggest a causal link between fractures and fluoride in patients with renal failure. Thus fluoride should be given at a lower dosage, if at all, to patients with even mild renal failure.

Aged↗
PubMed1983

Brodie's abscess in a tibia dating from the Neolithic period.

Radiological and macroscopic characteristics typical of Brodie's abscess were observed in inferior metaphysis of a tibia estimated to be 5,000 years old. The use of rigorous anatomico-radiological criteria in studies of bone paleopathology can provide the doctor with accurate data regarding diseases of the past in bone specimens rarely at their disposal. This approach is also necessary to obtain valid data for paleontologists, prehistorians and archeologists.

Abscess↗
PubMed1983

IR absorption spectrophotometric analysis of the complex formed by tetracycline and synthetic hydroxyapatite.

The infrared (IR) spectra of KBr pellet preparations of tetracycline (TC) complexes with hydroxyapatite (HA) indicated that the binding of the antibiotic to bone mineral can occur independently at each of two ligands. The shifts in the IR spectrum occur for the keto-enol ligand of rings B and C and for the tricarbonylmethane grouping of ring A. Analogs that lack one or the other of these groups are able to form complexes with HA in which the common portion resembles that of the parent molecule.

Chemical Phenomena↗
PubMed1983

Presumed calcified leiomyoma of the uterus. Morphologic and chemical studies of a calcified mass dating from the Neolithic period.

An isolated, calcified mass was found among human skeletal remains that were approximately 5,000 years old. A systematic study was undertaken that included histologic examination (stained sections, polarized light microscopy, microradiographs, and electron microscopy), x-ray diffraction, and concentrations of hydroxyproline and fluorine. The results allowed us to eliminate the diagnoses of bone tissue and intracavitary deposits such as bezoar and calculi. The mass consisted of calcified tissue, with a collagenous organic matrix and deposits of apatite, and it most probably was a calcified uterine leiomyoma.

Decalcification Technique↗
PubMed1980

Ultrastructural and cytochemical aspects of the initial phases of an experimental cutaneous calcinosis (calcergy) in the rat.

In rats a subcutaneous injection of KMnO4 leads to the calcification of the connective tissue. During mineral deposition, both intra- and extracellular changes are observed in the connective tissue. The intracellular phase is characterized by the formation of intramitochondrial granules and cytoplasmic vesicles, both in fibroblastic and extrinsic cells. In the extracellular phase, numerous heterogeneous matrix vesicles appear in the extracellular matrix. At the same time, globular particles which are resistant to microincineration, are observed between the collagen fibrils. The mineralization of the extracellular matrix takes place in two stages. The first stage comprises the appearance of needle-like structures and round aggregates. The needle-like structures are observed occasionally in the matrix vesicles and often in the extracellular matrix where they appear isolated or diverging from a central point. The round aggregates, composed of dense particles, are seen in the ground substance between the collagen fibrils. The second stage is characterized by a progressive mineralization of the collagen fibrils and the elastic fibers, without formation of extended calcified plaques.

Animals↗
PubMed1979

The mineralization processes in teleost fish scales.

In Teleost fish scales, growth and mineralization are continuous. Different mineralization processes can be distinguished. The external layer of the scale is the first to be mineralized and may be classified as the initial calcifying structure of the scale. The initial calcification loci are matrix vesicles of cellular origin always observed during the formation of this layer. This mineralization process takes place progressively, closely following the elaboration of the organic matrix in the scale periphery. The outer limiting and internal layers of the scale are developed after the external layer has been formed. A mineral substance is deposited without the mediation of matrix vesicles, but in contact with the previously mineralized external layer. This type of mineralization is called subsequential. However, the mineralization of the outer limiting layer closely follows the secretion of a collagen-free organic matrix and is thus different from the mineralization of the internal layer in which the calcification front remains remote from the collagen matrix surface and corresponds to a delayed mineralization process. The isolated calcifications (Mandl's corpuscles) which develop in the unmineralized laminae of the internal layer are mineralized in the absence of matrix vesicles and without making contact with a pre-existing calcified tissue, probably by a heterogeneous nucleation of the collagen fibrils.

Animals↗
PubMed1978

Mineral substance of bone tissue and of experimental cutaneous calcinosis in rats: chemical analysis and ESR study.

The evolution of the mineral constituents of subcutaneous calcinosis induced in rats by topical calciphylaxis was studied by the method of quantitative chemical analysis, and after treatment with excited gases by electron spin resonance (ESR) analysis. Chemical data show that the genesis of the subcutaneous calcinosis does not significantly alter the concentration of Ca, P, F, CO3, Mg, and Fe in the mineral phase of the femoral bone of calciphylactic rats. In the calcinosis an important increase of the fluoride concentration is noticed in function of the time after challenging. There is also a high concentration of Mg2+ ions in the early stages of the experimental calcification. Iron injected for the challenging is continuously present in the calciphylactic tissue after this treatment. This suggests that subcutaneous calcinosis might be a means of fixing certain heavy metal ions. After treatment with excited gases, the proportions of the trapped CO33- and O3- radicals are of the same order of magnitude in calciphylactic tissue after 12 days and observations in bone mineral. These suggest that after 12 days the mineral of the calciphylactic tissue has a crystalline state close to that of bone.

Animals↗
PubMed1978

Paramagnetic and crystallographic effects of low temperature ashing on human bone and tooth enamel.

Low temperature ashing by excited gas (LTA) causes crystallographic and paramagnetic alterations of the human bone and tooth enamel mineral. On the one hand, LTA induces variations of the alpha lattice parameter. These variations depend upon the nature of the gas used, but are little affected by its degree of excitation. Trapping of gas molecules in the crystal structure is demonstrated. On the other hand, LTA produces two preponderant paramagnetic centers in bone and enamel samples at 20 degrees C. Their inorganic origin clearly indicated. One of the two radicals has been identified as O3- (g1 = 2.002, g2 = 2.010, g3 = 2.016) and the other as (CO3-3 (parallel = 1.996, g = perpendicular 2.003). Variations of the alpha lattice parameter and trapping of paramagnetic gas species do not seem to be directly related.

Apatites↗