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Biomedical subjects

D J Hartmann

Publications and source records attributed to D J Hartmann.

At least 91 records · Page 5Linked to original sources
PubMed1989

Treatment of alcoholic hepatitis with colchicine. Results of a randomized double blind trial.

A randomized double-blind trial of colchicine vs placebo was conducted in 67 patients with histologically proven alcoholic hepatitis, 33 of whom had cirrhosis. Patients with hepatic encephalopathy, ascites, protracted prothrombin time, severe thrombocytopenia, hepatocellular carcinoma, evident lack of discipline or refusal to participate in the trial were not included. Thirty-three patients received colchicine (1 mg/day) and 34 received placebo for 6 months. Blood parameters including N-terminal peptide of type III procollagen were assessed in the serum, and a percutaneous liver biopsy was performed at the start of the trial and after 3 and 6 months. Alcoholic hepatitis and fibrosis scores were established for each biopsy specimen. Twenty-eight percent of patients were lost to follow-up at 3 months, and fifty-two percent at 6 months. One patient died of liver failure. Fifty-eight percent of patients were abstaining from alcohol at 3 months and fifty percent at 6 months. No significant effect of treatment was noted. Nevertheless, improvement in alcoholic hepatitis core at 3 months was more important in the colchicine group than in the placebo group. No side-effects were noted except transient diarrhea. Our results suggest that colchicine has no important effect on the course of alcoholic hepatitis. A trial including of at least 260 patients might be necessary for the observed alcoholic hepatitis score difference at 3 months, favoring colchicine, to be statistically significant.

Colchicine↗
PubMed1988

Gene expression of fibroblast matrix proteins is altered by indomethacin.

The role of indomethacin in the regulation of extracellular matrix synthesis was studied in dermal fibroblast cultures. Indomethacin (10 microM) blocked totally the prostaglandin secretion and markedly increased the synthesis of collagen. In parallel, measurement of fibronectin, type I and type III procollagen mRNA levels showed a substantial increase under the action of indomethacin. On the other hand, indomethacin did not modify the mRNA levels of dermatan sulfate proteoglycan core protein. Measurement of collagen production estimated as the amount of collagenase digestible protein and by specific radioimmunoassay indicated a good correlation with the corresponding mRNA levels. These results suggest that indomethacin can regulate the extracellular matrix deposition at a transcriptional level.

Cells, Cultured↗
PubMed1988

Antibodies to types I, II, IX, and XI collagen in the serum of patients with rheumatic diseases.

Antibodies to native types I, II, IX, and XI collagen were measured, using a 125I-solid-phase radioimmunoassay, in serum from 104 patients with rheumatic diseases (rheumatoid arthritis, osteoporosis, Paget's disease, or osteoarthritis). In all disease groups, antibodies to type II collagen occurred with greater frequency than antibodies to type I collagen (11-35% versus 5-23%). Antibodies to type XI collagen were the most frequent: They were present in approximately 50% of the patients in the rheumatoid arthritis, Paget's disease, and osteoporosis groups. Antibodies to type IX collagen were found at a high frequency in the rheumatoid arthritis group only (44%). Analysis of the clinical data suggested that the presence of antibodies to collagen was associated with disease that was less severe or of shorter duration.

Adult↗
PubMed1988

Distribution and synthesis of type I and type III collagens in developing mouse molar tooth root.

The distribution and synthesis of type I and type III collagens in the mouse molar tooth root have been investigated by correlating light and electron immunohistochemical data. Purified rabbit antibodies were raised against mouse type I and type III collagens and indirect immunoperoxidase procedures were used. In these conditions, predentin, pre-bone, and pre-acellular cementum were intensely immunostained for type I collagen. Both optic and ultrastructural data confirmed the presence of type I collagen at the epithelio-mesenchymal junction, but Hertwig's basement membranes remained unlabelled. The odontoblasts including the short polarized ones, osteoblasts, some cells of pulp mesenchyme and the perifollicular cells possessed type I collagen immunoreactivity in the rough endoplasmic reticulum (RER), Golgi complex and the secretory vesicles. Type III collagen immunoreactivity was strong in the perifollicular mesenchyme, light in the pulp mesenchyme and absent from the epithelio-mesenchymal junction, the predentin, pre-bone and pre-acellular cementum. Intracellular immunolabelling was detected at the ultrastructural level in the perifollicular cells by a faint homogeneous peroxidase deposit in the RER cisternae. Finally, these results, compared with previous biochemical and morphological data, represent the first dynamic aspect of collagens distribution and synthesis in the mouse molar root development. In terms of cell differentiation, our data also suggest that type III collagen synthesis does not occur during the odontoblast process of differentiation.

Animals↗
PubMed1988

Localization and synthesis of type III collagen and fibronectin in human reparative dentine. Immunoperoxidase and immunogold staining.

The injury of dental pulp tissue, following caries, is accompanied by the deposit of a typical hard scar tissue known as reparative dentine which should be regarded as the mineralization of a new organic matrix. Highly purified antibodies were used in combination with immunoperoxidase or immunogold technique at the ultrastructural level to reveal the distribution and synthesis of types I and III collagen and fibronectin elaborated by typical matrix-forming cells in the new tissue. Specific immunoperoxidase labelling, on demineralized teeth, clearly demonstrated that type I collagen represents the main type of collagen (88%). It is associated with bundles of fine striated fibrils of type III collagen and in close vicinity with fibronectin and constituted, at least, the new organic matrix of reparative dentine. Immunogold staining gave precise localization mainly over Golgi apparatus for the 3 components, thus suggesting that the cells concerned should not be considered as new odontoblasts but rather as pulpal cells in the process of differentiation participating in the formation of new dentine. Moreover, these events are very similar to those observed during wound healing in other tissues.

Collagen↗
PubMed1988

Distribution and organization of the elastic system fibres in healthy human gingiva. Ultrastructural and immunohistochemical study.

The ultrastructural distribution and organization of the elastic system fibres, i.e. oxytalan, elaunin and elastic fibres, were studied by transmission electron microscopy and by an immunohistochemical method for the detection of elastin in healthy human gingiva. The morphological distribution of these fibres was characterized by the presence of oxytalan, elaunin and elastic fibres, respectively, in the upper, medium, and deep layers of gingival connective tissue. Anti-elastin antibody reacted with microfibrils and amorphous material of the elastic system fibres throughout the gingival connective tissue. These findings were interpreted as indicating that the microfibrils were associated with small amounts of elastin at their surface.

Adult↗
PubMed1988

Rabbit articular chondrocytes: an in vitro model for studying the effect of sodium aurothiopropanol sulfonate on proliferation kinetics, type II collagen phenotype and mitochondrial activity.

Despite the benefits of chrysotherapy the responsible mechanism of action of gold compounds remains unclear. At a concentration of 5 x 10(-4) M, sodium aurothiopropanol sulfonate (SAS) modified the in vitro proliferation kinetics of articular chondrocytes by reducing growth, viability and plating efficiency. Flow cytometry analysis, using propidium iodide DNA staining, revealed slight but significant cell arrest in G2+M which, in fact, represents an increase in the proportion of binucleate cells. SAS did not induce any variations in chondrocyte phenotype stability as far as the biosynthesis of type II collagen was concerned, and no appreciable changes in overall mitochondrial activity reflected by rhodamine 123 incorporation.

Animals↗
PubMed1988

[Serum laminin and portal pressure in alcoholic cirrhosis. A study of 39 patients].

A correlation between serum laminin, a glycoprotein found in basement membranes, and hepatic wedge pressure has previously been reported in a small number of patients with various liver diseases. To study this relationship in patients with alcoholic cirrhosis, we measured the wedge hepatic pressure and venous gradient, in comparison with serum concentrations of laminin and collagen metabolism products: N-terminal peptide of type III procollagen, collagen type I, and collagen type III in 39 patients. A statistically significant correlation was observed between serum laminin and wedged hepatic pressure (r = 0.529; p less than 10(-3] or hepatic venous gradient (r = 0.482; p = 0.002). By contrast, no statistically significant correlation was found between hemodynamic parameters and serum concentrations of N-terminal peptide of type III procollagen, collagen type I or collagen type III. These results suggest that, in patients with alcoholic cirrhosis, portal pressure may be estimated by serum concentration of laminin, and that perisinusoidal fibrosis, especially basement membrane thickening, may play an important role in the pathogenesis of portal hypertension in these patients.

Blood Pressure↗
PubMed1988

In vivo cell interactions with calcium phosphate bioceramics.

Biointegration, resorption process, and solubility in physiological environments of calcium phosphate materials are scarcely described by ultrastructural studies. In vivo cells interactions with calcium phosphate materials are scarcely described by ultrastructural studies. In vivo cells interactions with calcium phosphate biomaterials are mediated by different proteins from physiological fluid, and in order to observe at the ultrastructural level the cell colonization, the resorption, process and the biointegration, we used in these experiments calcium phosphate materials precoated with fibronectin or not precoated. Two kinds of well determined materials were used for this study, Beta-tricalcium phosphate (B-TCP) and hydroxyapatite (HAP). The implants were soaked in human fibronectin diluted solution and were implanted in the connective tissue of rabbit abdomen. Our results showed that the fibroblasts and macrophagous++ cells interaction with the calcium phosphate crystal (B-TCP and HAP) was more important in the experiments with a fibronectin bilayer. In the presence of fibronectin at the grains surface of the material, cystic cavities' or fibrous encapsulation was suppressed and cells with fibers were in close contact with the material. The presence of fibronectin immediately after implantation seemed to increase the adhesion and the cell colonization. Fibronectin creates an organic interface between crystals and cells, and can promote interactions from cells and biomaterials.

Abdomen↗
PubMed1987

Wound healing of human skin transplanted onto the nude mouse. II. An immunohistological and ultrastructural study of the epidermal basement membrane zone reconstruction and connective tissue reorganization.

The reconstruction of human epidermis during healing of human skin wounded after grafting onto the nude mouse was described in a previous paper (M. Démarchez, P. Sengel, and M. Pruniéras, 1986, Dev. Biol. 113, 90-96). The regeneration of the epidermal basement membrane zone (BMZ) and the reorganization of the connective tissue are the subjects of the present study. They were investigated by two complementary methods: electron microscopy to analyze the BMZ reorganization, and indirect immunofluorescence with species-specific and cross-reacting antibodies directed against laminin, bullous pemphigoid antigen, mouse or human collagens of types I or IV, human elastic fibers, fibronectin, fibrin, actin, and human vimentin, to examine the species origin and distribution of BMZ and connective tissue components during the regeneration process. It is reported that grafted human skin preserves its own immunological markers not only in the epidermis but also in the BMZ and dermis as well, and that, after injury, its regeneration proceeds according to the following sequence of overlapping events: production of a mouse granulation tissue; reepidermization by human cells; reconstruction of a BMZ with human characteristics; formation of a human neodermis. It is concluded that human skin grafted onto the nude mouse is able to regenerate its three structural compartments, namely, the epidermis, BMZ, and dermis. Interestingly, it appeared, also, that the connective tissue regeneration would be a two-step mechanism including the sequential formation of two tissues of distinct sources, namely, a granulation tissue and a neodermis.

Animals↗
PubMed1987

Supernatant from an activated human CD4+ T-cell clone modulates the proliferation and collagen synthesis of human dental pulp fibroblasts.

Several studies indicate a relationship between immunocompetent cells and fibroblast functions such as proliferation and collagen synthesis, which may be of importance in understanding the process of fibrosis. We demonstrate here the activity of supernatant from an activated human CD4+ proliferative T-cell clone (2F1) in stimulating the proliferation of human dental pulp fibroblasts, while inhibiting their soluble type I collagen secretion in either growing or confluent cultures. Taken together, our results indicate that T-cell derived lymphokines may be of importance in regulating normal dental pulp fibroblast functions.

Cell Division↗
PubMed1987

In vitro morphogenesis of chick embryo hypertrophic cartilage.

Dedifferentiated chick embryo chondrocytes (Castagnola, P., G. Moro, F. Descalzi-Cancedda, and R. Cancedda, 1986, J. Cell Biol., 102:2310-2317), when transferred to suspension culture on agarose-coated dishes in the presence of ascorbic acid, aggregate and remain clustered. With time in culture, clusters grow in size and adhere to each other, forming structures that may be several millimeters in dimension. These structures after 7 d of culture have the histologic appearance of mature hypertrophic cartilage partially surrounded by a layer of elongated cells resembling the perichondrium. Cells inside the aggregates have ultrastructural features of stage I (proliferating) or stage II (hypertrophic) chondrocytes depending on their location. Occurrence and distribution of type I, II, and X collagens in the in vitro-formed cartilage at different times of culture, show a temporal and spatial distribution of these antigens reminiscent of the maturation events occurring in the cartilage in vivo. A comparable histologic appearance is shown also by cell aggregates obtained starting with a population of cells derived from a single, cloned, dedifferentiated chondrocyte.

Animals↗
PubMed1987

Ultrastructural immunolocalization of elastic fibers in rat blood vessels using the protein A-gold technique.

Identification of elastic fibers at the ultrastructural level is accomplished by a post-embedding immunohistochemical technique using the protein A-colloidal gold method. Antisera against elastins from human dermis and rat aorta have been characterized by radioimmunoassay and then applied to thin sections of rat blood vessels. Two fixative solutions and two embedding media have been tested. Both antibodies bind to elastic fibers of normal arteries and veins, indicating crossreactions among organs and species. The high sensitivity of this method is demonstrated by its application to the detection of neo-elastogenesis in the intimal thickening of aortic grafts.

Animals↗
PubMed1987

An immunohistological study of the revascularization process in human skin transplanted onto the nude mouse.

The revascularization of human skin transplanted onto the nude mouse was studied by performing double-labeling immunofluorescence microscopy on human skin before transplantation and at different stages, ranging from one week to six months after grafting. With a crossreacting anti-factor-VIII antigen antibody used to identify the endothelial cells, and with human-specific monoclonal antibodies directed against vimentin or HLA-DR antigen, it appeared that the original human endothelial cells of transplanted skin progressively disappear, while murine endothelial cells invade the graft. Moreover, in double-labeling experiments with a crossreacting anti-factor-VIII antibody and a human-specific anti-type-IV-collagen antibody, anastomosis between host and graft vessels and a constant codistribution of graft endothelial cells with human type IV collagen were observed. Finally, double staining with species-specific antibodies directed against murine or human type IV collagen showed that mouse type IV collagen appeared progressively in the graft and was constantly colocalized with human type IV collagen. From these observations, it was concluded that revascularization of human skin transplanted onto the nude mouse proceeds as follows: inoculation; disappearance of human endothelial cells and migration of mouse endothelial cells into the graft over the basement membrane of preexisting human vessels; and production of a new vascular basement membrane by mouse endothelial cells on the original basement membrane of human graft vessels.

Animals↗