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Biomedical subjects

A Rebel

Publications and source records attributed to A Rebel.

At least 19 recordsLinked to original sources
PubMed1990

Concentration of bone elements in osteoporosis.

In aging and in osteoporosis, decreased bone density is associated with decreased bone mass. However, changes in the bone mineral phase remain a matter for investigation. In particular, it is unknown whether bone mineral loss is directly related to reduction in bone mass or associated with changes in the concentration of mineral elements in mineralized bone tissue. In this study, the cortical bone concentration of elements was determined in biopsies of the ilium from 33 subjects (12 controls and 21 individuals with untreated severe osteoporosis). Calcium and phosphorus concentrations were evaluated in cortical and trabecular bone using energy-dispersive x-ray (EDX) microanalysis and inductively coupled plasma optical emission spectrometry (ICPOES). Bone concentrations of Na, K, Mg, Cu, Zn, Fe, Sr, Al, B, and Si were also determined in cortical bone using ICPOES. Additionally, the concentration of F in cortical bone was measured with a specific ion electrode and the concentration of Pb was determined by atomic absorption spectrometry. In mineralized bone tissue there was no significant age-dependent variation in the concentration of Ca, P, or other elements either in controls or in osteoporotic subjects. Moreover, the concentration of elements in bone tissue did not differ in the two groups. These results suggest that the decrease in bone density in osteoporosis is directly related to evolution of the bone mass, without detectable changes in the concentration of elements in bone.

Adult↗
PubMed1989

[Paget's bone disease. Epidemiology and etiology].

Paget's bone disease is a chronic and usually benign bone disorder mainly found in people over fifty. The condition is characterized by excessive bone remodelling related to bone cell overactivity leading to abnormal bone structure. The viral origin of the disease, first proposed on the basis of ultrastructural observations, is now supported by immunocytological and molecular hybridization studies. Genetic and environmental elements may be involved, favouring and modulating the expressivity of this slow virus infection.

Humans↗
PubMed1989

Effect of N2O on segmental left ventricular function and effective arterial elastance in pigs when added to a halothane-fentanyl-pancuronium anesthetic technique.

The interaction of various concentrations of N2O and a stable halothane-fentanyl-pancuronium anesthetic technique was examined in nine pigs. Segmental myocardial contractility was measured with the end-systolic pressure-length relationship (Ees), and the effective arterial elastance (Ea) was quantified based on the Windkessel model. The addition of 30, 50, and 70% N2O did not change myocardial contractility or the effective arterial elastance. During the 30 and 70% N2O challenge, however, arterial capacitance decreased significantly from a mean (+/- SEM) 0.86 +/- 0.15 to 0.71 +/- 0.0.11 mL/mm Hg with 30% N2O (P less than 0.05) and from 0.90 +/- 0.09 to 0.71 +/- 0.07 mL/mm Hg (P less than 0.05) with 70% N2O. A dose-response relationship for the effect on the arterial capacitance could not be demonstrated. We concluded that in the presence of halothane, fentanyl, and pancuronium, N2O does not depress the normal myocardium or change left ventricular afterload. The decrease in arterial capacitance that occurred when 30 and 70% N2O were given was not sufficient to change the effective afterload and appears to be of no importance to normal left ventricular function.

Animals↗
PubMed1989

Effect of various propofol plasma concentrations on regional myocardial contractility and left ventricular afterload.

The cardiovascular effects of propofol infusions, designed to maintain constant plasma concentrations, were examined in an open-chested pig model. Regional myocardial contractility was measured with the end-systolic pressure-length relationship (Ees) and left ventricular afterload quantified by the effective arterial elastance (Ea). The propofol plasma concentrations in this study varied between 0 and 7.73 (SEM 0.96) micrograms/mL. A significant correlation for the increasing propofol plasma concentration and a decrease in myocardial contractility (P = 0.0056) was demonstrated, and the Ea remained constant. This gave rise to a reduction in stroke volume (P = 0.002) and, combined with a decrease in the heart rate (P = 0.0001), led to a reduction in the cardiac output (P = 0.0001). When the propofol infusion was stopped, myocardial contractility did not recover in parallel with the decrease in plasma propofol concentration.

Anesthetics↗
PubMed1988

Isolation of osteoclasts from Pagetic bone tissue: morphometry and cytochemistry on isolated cells.

Giant osteoclasts and other cells were isolated from Pagetic bone tissue using 0.5 mM ethylene diamine tetraacetic acid on bone samples from 8 patients with Paget's disease. The cell suspension contained osteoclasts and osteoblasts as well as some mononuclear cells such as monocytes. The number of nuclei in isolated osteoclasts (33.85 +/- 20.92 nuclei/osteoclast) correlates fairly well (p less than 0.02) with the number of nuclei counted on histologic sections (15.88 +/- 11.80 nuclei/osteoclast) for samples from each patient. Enzyme histochemistry demonstrated acid phosphatase activity in isolated osteoclasts and in mononucleated cells, such as monocytes. Alkaline phosphatase was detected only in osteoblasts while succinate dehydrogenase was observed in osteoclasts, osteoblasts and monocytes. Esterases, such as nonspecific aliesterase and specific naphthol AS-D acetate esterase, were identified in osteoclasts and in macrophages. Inhibition of specific naphthol AS-D acetate esterase in osteoclasts by addition of sodium fluoride suggests that the enzyme could be of monocytic origin.

Esterases↗
PubMed1988

Flow cytometric DNA analysis in the diagnosis of lung tumors. A comparison with conventional methods.

The efficiency of flow cytometric (FCM) DNA analysis in the diagnosis of lung carcinoma was compared with that of conventional cytologic techniques on bronchial brushing and fine needle aspiration samples from 461 patients. The main advantage of FCM was the rapid delivery of results. Unfortunately, this was offset by a poor sensitivity in the detection of bronchial tumors. Nevertheless, DNA analysis may still prove useful in determining the prognosis and in evaluating the effects of chemotherapy on known tumor stem lines.

Biopsy, Needle↗
PubMed1987

Sarcomatous degeneration in Paget's bone disease.

The authors report 12 cases (8 men and 4 women) of sarcomatous degeneration in Paget's bone disease, with an average age of 72.3 years. Sarcomatous degeneration occurred often in polyostotic Paget's disease, and osteitis deformans was seen in 4 cases. Femur and pelvis were the most affected bones. Pain was a constant feature, whereas tumefaction and fracture were less common. Osteolytic lesions were more frequent than condensed or mixed lesions and radiological signs of malignancy were usually found. Seven cases were histologically classified as osteogenic sarcoma and 3 cases as fibrosarcoma. Electron microscopy was performed on 2 osteogenic sarcomas and in 1 case revealed microcylindrical inclusions in Pagetic osteoclasts and in multinucleated giant tumor cells, but none in mononucleated tumor cells. The average survival time for the patients in this study was only 4.5 months.

Aged↗
PubMed1987

On the trail of paramyxoviruses in Paget's disease of bone.

The ultrastructural discovery of microcylindric inclusions in the nuclei and cytoplasm of osteoclasts in tissue affected by Paget's disease of bone has created a new approach. The morphologic similarity of the inclusions to viral structures has stimulated further studies involving immunocytologic techniques and in situ hybridization. Polyclonal antibodies reveal the presence of paramyxovirus antigens and measles virus and respiratory syncytial virus in pagetic osteoclasts. Monoclonal and monospecific polyclonal antibodies demonstrate paramyxovirus antigens of measles virus, simian virus (SV5), and human parainfluenza virus (PF3). In situ hybridization carried out with a 3H-labeled DNA probe, specific for the measles nucleocapsid protein, detects measles virus nucleotide sequences in the nuclei and cytoplasm of pagetic osteoclasts, confirming ultrastructural and immunocytologic findings. Surprisingly, the tritiated probe also hybridizes with a large proportion of mononucleated cells: osteoblasts, osteocytes, fibroblasts, and lymphocytes. This suggests a very wide host cell range for measles virus genomic information which, however, would appear to undergo translation only in osteoclasts. The cause-effect relation between the viral information contained by diseased bone cells and Paget's disease of bone remains to be established.

Antibodies, Monoclonal↗
PubMed1986

Measles virus RNA detected in Paget's disease bone tissue by in situ hybridization.

Morphological and immunocytological studies have demonstrated the presence of paramyxovirus antigens in Paget's bone disease tissue and in particular antigens related to measles virus and respiratory syncytial virus. To examine the relationship between measles virus and Paget's bone disease we used in situ hybridization and a cloned measles virus DNA probe specific for the nucleocapsid protein to detect and locate measles virus RNA sequences in Paget's bone tissue. In five patients with the disease, measles virus RNA sequences were detected not only in 80 to 90% of the multinucleated osteoclasts where there is morphological and immunocytological evidence of measles virus activity but also in 30 to 40% of mononucleated bone cells, mainly osteoblasts, osteocytes, fibroblasts and lympho-monocytes. In contrast, no hybridization was observed in bone tissue from three control patients without signs of Paget's bone disease. These results indicate that the host cell range for measles virus in Paget's disease is more widespread than has been supposed. They also demonstrate the usefulness of the in situ hybridization method to detect viral genetic information in cells where viral antigenic activity is not detectable. These observations further support the hypothesis that measles virus is involved in the pathogenesis of Paget's bone disease.

Bone and Bones↗
PubMed1986

Flow DNA analysis in human lung cancer: potentiality and limitations due to sampling methods.

Flow DNA analysis was performed on samples from 71 surgically removed lung cancers and from 145 patients undergoing bronchoscopy. Abnormal DNA stem lines, characterized by their DNA index (DI), were frequently observed in operated lung carcinomas (87%). Two or three abnormal DNA stem lines were discovered simultaneously in 10% of the samples. The mean DI of all abnormal tumor stem lines was lowest for rare tumor cell types and highest for adenocarcinomas. Intermediate mean DI values were found for epidermoid and small cell carcinomas, which were among the most proliferative tumors. The high rate of false negative results suggests poor diagnostic reliability of flow DNA analysis on bronchoscopic samples. However, the method appears to provide a promising objective tool capable of evaluating tumor behavior and prognosis.

Adenocarcinoma↗
PubMed1986

[Evaluation of the use of bronchial brushings after cytocentrifugation in the diagnosis of bronchial tumors (475 fibroscopies)].

Since 1971, cytodiagnosis of lung tumors by association of the bronchial brushing and cytocentrifugation techniques has been carried out routinely at the University Hospital of Angers. Our study covers 475 cytodiagnoses of bronchial brushings. The results obtained enable an evaluation of the diagnostic efficiency of bronchial brushing in the detection of lung tumors. The technique is convenient for routine screening and in several cases contributes directly to diagnosis.

Adenocarcinoma↗
PubMed1986

[Contribution of modern research technics to the identification of a virus in Paget's disease of bone].

The morphological resemblance between osteoclast inclusions in Paget's bone disease and viral structures has encouraged new research with immunocytologic methods and In Situ hybridization. Paramyxovirus antigens of measles virus and respiratory syncitial virus were detected in pagetic osteoclasts using polyclonal antibodies. Paramyxovirus antigens of measles virus, simian virus (SV 5) and human parainfluenza virus (PF 3) were demonstrated using monoclonal and monospecific polyclonal antibodies. Measles virus nucleotide sequences were detected in pagetic osteoclasts by In Situ hybridization with a 3H labelled cDNA probe specific for measles nucleocapsid protein. However, the same probe also hybridized with several types of mononucleated cells suggesting a wide host range for measles virus genomic information. Apparently, this viral information is translated only in the osteoclasts. The link between the presence of viral information in pagetic bone tissue cells and Paget's disease itself still awaits elucidation.

Bone and Bones↗
PubMed1985

Paramyxovirus antigens in osteoclasts from Paget's bone tissue detected by monoclonal antibodies.

The fluorescent antibody technique using both monoclonal and specific polyclonal virus antibodies was applied to investigate the nature of the inclusions seen in the abnormal osteoclasts associated with Paget's bone disease. The results show that antigens of measles virus, simian virus 5 (SV5) and human parainfluenza virus type 3 (PF3) could be detected in the osteoclasts but not in control bone cells. Measles and SV5 nucleoprotein (NP) and haemagglutinin-neuraminidase (HN) antigens were apparently present in all the cases of Paget's disease examined, whereas PF3 NP and HN antigens were present only in some of the cases. These investigations suggest that paramyxoviruses may play a role in the aetiology of the bone disease.

Antibodies, Monoclonal↗
PubMed1985

[Cellular aspects of reorganization of pagetic bone tissue].

The light microscopy features of the cellular reorganisation of tone tissue in Paget's disease are well known. They result in the constitution of abnormal bone tissue. Ultrastructural studies have enabled a more detailed study of osteoblasts, osteocytes and osteoclasts. Osteoclasts are the only cells which present abnormalities. In particular, we observe intranuclear and intracytoplasmic inclusions composed of microcylinders. The morphological analysis is able to relate the presence of these formations with a viral infection of the paramyxovirus group. The results obtained by immunocytochemical techniques support this hypothesis. The osteoclast lesion could be a determining factor in the abnormal reorganization of bone tissue in Paget's disease, which may be considered to be a disease due to a slow acting virus.

Bone and Bones↗
PubMed1984

Bone tissue in Paget's disease treated by ethane-1, hydroxy-1, 1 diphosphonate (EHDP). Structure, ultrastructure, and immunocytology.

Diphosphonates have been used in the management of Paget's disease of bone because of their experimentally demonstrated antiosteoclastic activity. Light microscopic examination of bone tissue from 13 patients with Paget's bone disease who were receiving (EHDP) treatment showed considerably reduced osteoclastic resorption accompanied by gradual replacement of irregular woven bone by lamellar tissue. Electron microscopic examination confirmed that pagetoid osteoclasts are morphologically abnormal cells and degenerate after EHDP treatment. EHDP does not affect the measles nucleocapsid-like inclusions in the osteoclast nuclei. Immunocytologic analysis showed that during EHDP treatment viral antigens of the measles type persist in the cytoplasm and nuclei of osteoclasts even when these cells are greatly altered. These findings support the hypothesis of a viral etiology in Paget's disease of bone.

Aged↗
PubMed1983

[Paget's bone disease. Preliminary serological study].

A serological study has been carried out in Paget's bone disease where the etiology still remains uncertain. Previous work on patients with the disease revealed specific osteoclast inclusions that could be linked to the presence of a virus of the paramyxovirus group. Conventional methods for exploring humoral immunity reveal no great differences in the concentration of antibodies against the various viral strains tested on sera from 46 patients with Paget's bone disease and from 46 paired controls. The viral origin of Paget's bone disease is reconsidered in the light of the results obtained. The eventuality of sub-threshold viral infection and the possible action of incomplete or defective virus leading to the chronic nature of the disease are discussed.

Aged↗