Methyl Methacrylate Embedding Research Articles

A histochemical method for the demonstration of calcifying cartilage.

The demonstration of histochemical characteristics in calcifying cartilage is fraught with methodological difficulties including the distinction of mineralized from unmineralized cartilage and the demonstration of cell detail in relatively hard tissue. This study uses the decalcified bone matrix-induced enchondral (endochondral) ossification system to demonstrate a technique of methylmethacrylate embedding, thin sections, and a combination of histochemical stains that distinguishes mineralized from unmineralized cartilage while preserving excellent cell detail. These techniques are applicable to other areas of enchondral ossification and are exemplified by the staining of growth plates.

Microwave-aided technique to detect bromodeoxyuridine in S-phase cells using immunogold-silver staining and plastic-embedded sections

A technique is described to detect bromodeoxyuridine (BrdU) incorporated by cells in S-phase, with a monoclonal antibody, using removable plastic embedding and immunogold-silver staining (IGSS). The incubation times were reduced and the immunological reactions enhanced by microwave irradiation. The embedding in methyl methacrylate enabled us to make thinner sections and it improved the quality of the preparations. The methyl methacrylate did not hinder the reaction of BrdU with the antibody because it could be removed prior to the IGSS procedure. The IGSS procedure appeared to be very sensitive, requiring lower concentrations of the antibodies than other methods. The use of microwave irradiation shortened the time needed to stain a section from 7 to less than 4 h. Furthermore, using microwave irradiation, the concentration of the antibodies needed could be reduced even further compared with the normal IGSS procedure. In sections of the mouse testis and small intestine only nuclei of cells known to be able to proliferate appeared BrdU positive. The non-specific background staining was found to be negligible. In testes of mice that received both 3H-thymidine and BrdU more than 95% of the radioactively labelled cells also showed BrdU label and vice versa. This indicates that both methods are equally sensitive for detecting cells in S-phase.

Alkaline and acid phosphatase demonstration in human bone and cartilage: effects of fixation interval and methacrylate embedments.

Human bone and cartilage specimens were evaluated for acid and alkaline phosphatase localization following varying fixation periods for fresh or frozen tissue. Formalin fixations of up to 183 hr were followed by embedment in methyl methacrylate; frozen tissue was examined either without fixation or following fixation for up to 1 hr and subsequent glycol or methyl methacrylate embedding. The humeral epiphysis of a young patient with osteogenic sarcoma showed optimum acid and alkaline phosphatase localization following fixation for periods up to 15 hr and embedding in methyl methacrylate. Frozen costochondral junction from a newborn with osteogenesis imperfecta type II showed optimum acid and alkaline phosphatase localization following 30 min fixation in formalin and embedding in methyl methacrylate or after 5 min fixation and embedding in glycol methacrylate.

A New Methyl Methacrylate Embedding Method for Rapid Histochemical Demonstration of Phosphatases in Undecalcified Bone Tissue

A new methyl methacrylate embedding medium, Medim K-Plast, is used for histochemical demonstration of acid and alkaline phosphatase activities in undecalcified rat femurs. Fixation, dehydration, and embedding are completed within four days. The method requires no explosive initiator for polymerization, and there are no water bath temperature peaks exceeding 35°C. The method can be adapted to routine laboratory. conditions with a large number of tissue specimens. Short incubation times of 30 to 60 minutes are sufficient to demonstrate enzyme activities by simultaneous coupling azo dye methods. Enzyme activity is retained after storage of blocks for 3 months at 4°C or in sections at −20°C for 4 weeks. Alkaline phosphatase activity for investigation of bone growth is unsatisfactory because the enzyme is associated not only with osteoblasts, but with reticular cells of bony trabeculae. Demonstration of newly formed bone matrix with Solochrome cyanine R staining, therefore, is done without prior deplasticizing of the sections. (The J Histotechnol 10: 103, 1987)

A New Methyl Methacrylate Embedding Method for Rapid Histochemical Demonstration of Phosphatases in Undecalcified Bone Tissue

A new methyl methacrylate embedding medium, Medim K-Plast, is used for histochemical demonstration of acid and alkaline phosphatase activities in undecalcified rat femurs. Fixation, dehydration, and embedding are completed within four days. The method requires no explosive initiator for polymerization, and there are no water bath temperature peaks exceeding 35°C. The method can be adapted to routine laboratory. conditions with a large number of tissue specimens. Short incubation times of 30 to 60 minutes are sufficient to demonstrate enzyme activities by simultaneous coupling azo dye methods. Enzyme activity is retained after storage of blocks for 3 months at 4°C or in sections at −20°C for 4 weeks. Alkaline phosphatase activity for investigation of bone growth is unsatisfactory because the enzyme is associated not only with osteoblasts, but with reticular cells of bony trabeculae. Demonstration of newly formed bone matrix with Solochrome cyanine R staining, therefore, is done without prior deplasticizing of the sections. (The J Histotechnol 10: 103, 1987)

Simultaneous demonstration of bone alkaline and acid phosphatase activities in plastic-embedded sections and differential inhibition of the activities.

Bone alkaline (AlP) and acid phosphatase (AcP) activities were simultaneously demonstrated in tissue sections obtained from mice, rats, and humans. The method involved tissue fixation in ethanol, embedding in glycol methacrylate (GMA), and demonstration of AlP and AcP activities employing a simultaneous coupling azo dye technique using substituted naphthol phosphate as a substrate. AlP activity was demonstrated first followed by AcP activity. Both enzyme activities were demonstrated in tissue sections from bones fixed and/or stored in acetone or 70% ethanol for up to 14 days or stored in GMA for 2 months. AlP activity in tissue sections from bones fixed in 10% formalin, 2% glutaraldehyde, or formal-calcium, however, was markedly inhibited after 3-7 days and was no longer detectable after 14 days of fixation. Moreover, AlP activity was diminished in tissue sections from bones fixed in 70% ethanol or 10% formalin and subsequently demineralized in 10% EDTA (pH 7) for 2 days, and the activity was completely abolished in tissue sections from bones subsequently demineralized in 5% formic acid: 20% sodium citrate (1:1, pH 4.2) for 2 days. Methyl methacrylate (MMA) embedding at concentrations above 66% completely inhibited AlP activity. AcP activity, however, was only partially inhibited by formalin, glutaraldehyde, or formal-calcium after 7 or 14 days of fixation or by MMA embedding and was unaffected by the demineralizing agent formic acid-citrate for 2 days. While AcP activity was preserved in bones fixed in formalin and subsequently demineralized in EDTA, the activity was completely abolished when EDTA demineralization was carried out on bones previously fixed in 70% ethanol.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone embedding in pure methyl methacrylate at low temperature preserves enzyme activities

Pure Methyl Methacrylate (MMA), a widely used embedding medium for undecalcified bone studies, was polymerized at low temperature (4 degrees C). MMA was prepared by a new purification procedure yielding a absolutely anhydrous and catalysed resin. The redox system benzoyle peroxide/NN-Dimethylanilin was used as the catalyzer-initiator system providing free radicals for the MMA chemical polymerization. Since the reaction is inhibited at -20 degrees C, complete infiltration of blocks is achieved within 3 d. Polymerization took place at +4 degrees C. The method provides undecalcified bone sections suitable for histomorphometric analysis of osteoid tissue, tetracycline bone labeling and Tartrate Resistant Acid Phosphatase. Enzyme histochemistry was shown to be possible in pure MMA embedded bones, when this low temperature embedding was used.

Sclerotic bone metastasis: radiologic-pathologic correlation.

Radiographic appearances were correlated with histologic findings in sclerotic bone metastases. For this purpose, undecalcified ground sections were made from lumbar vertebrae obtained at 12 autopsies. The primary tumor sites were the prostate gland in five cases, the breast in three, the lung in two, the stomach in one, and the urinary bladder in one. After Villanueva bone staining and methyl methacrylate embedding, 1-mm-thick ground sections were made for low-kilovoltage contact radiography. In sclerotic bone metastases, new bone is deposited on preexisting trabeculae and in the intertrabecular spaces, forming lacy networks. The radiographic indications of these histologic changes are trabecular thickening, marginal obscurity (the "silhouette" sign), and homogeneous dense sclerotic change. The silhouette sign in bone is a new concept, one that is helpful when the changes in density are not reliable.

Friable rock embedding in methyl methacrylate for thin‐sectioning in geological preparations

SUMMARYIn most cases, technical problems prevent the production of good geological thin‐slabs from friable rocks such as muds, sands or decomposed granites. Usual impregnation methods using Araldite or epoxies lead to incompletely impregnated blocks. Furthermore the excessive heat occurring during polymerization alters the micromorphology of heat sensitive minerals. Methyl methacrylate (MMA) is a widely used plastic for bone embedding. We have developed a new procedure using vacuum infiltration with MMA in a cold environment. Wafers from friable rocks are easily obtained and can be processed in the same way as those of firm and coherent rocks, without grain loss nor mineral heat alterations.

A Rapid Method For Methyl Methacrylate Embedding of Mineralized Bone Specimens

Abstract A method for methyl methacrylate embedding of mineralized bone specimens is described which takes only one week to complete. The resulting tissue block is easy to section and the four micron thick sections can be deplasticized and stained with routine or special stains.

A Rapid Method For Methyl Methacrylate Embedding of Mineralized Bone Specimens

A method for methyl methacrylate embedding of mineralized bone specimens is described which takes only one week to complete. The resulting tissue block is easy to section and the four micron thick sections can be deplasticized and stained with routine or special stains.

The amount of white pulp in the spleen; a morphometrical study done in methacrylate-embedded splenectomy specimens

This report deals with a morphometrical study on 92 surgically removed human spleens, to investigate the composition of spleens which are considered to be normal, i.e. spleens which had ruptured in traffic accidents or which had been incidentally removed during abdominal operations. A comparison was made with 16 spleens with hypersequestration of platelets and to 11 with hyper-sequestration of erythrocytes. Methyl-methacrylate embedding was used because of the superiority of this technique over conventional paraffin embedding. Significant differences were found between both 'normal' groups as to the absolute and relative amount of white pulp as well as the perifollicular red pulp zone. Based also on the few morphometrical reported studies in the literature, spleens removed during abdominal surgery form the best control group. Traumatic rupture of the spleen in traffic accidents might specifically occur in spleens which already contained a stimulated lymphatic compartment. A probably non-specific increase of white pulp was found in splenomegaly of varied aetiology. An expected influence of age on weight and composition of the spleen was not found in our study. The spleen changes in weight and composition only up to 5 years of age. Significant involution at older age was not found in ours nor in other reported larger series.

Histologische untersuchungen über umbauvorgänge an der zement-knochengrenze bei endoprothesen nach 3-bis 10-jähriger implantation

The prosthesis loosening represents the main complication of an endoprosthesis. When using bone cement for an anchorage, the most important factors of loosening are the impairment of tissue during toxical and thermic influence, foreign body reaction on the abraded material of the prosthesis, the resorption effect through foreign body giant cells as well as the parallel effect of monomer impoverishment and the dissapearance of polymerization matrix material. Histological examinations of the reparation proceedings of not loosened cement-bone surfaces at total endoprostheses are rarely found in literature, and the extent of a long term effect of the cement on the bone layer has not been sufficiently ascertained. To obtain an insight into the reaction of the bone tissue to the bone cement, the bone-cement surface was examined histologically after 3—10 years TEP-implanation. Material and Methods. Eleven specimens of roentgenology and macroscopic fixed bone cement-bone connexion of non-infected TEP were being studied. The interval between surgery and reoperation ranged from 3, 3,3, 3,5, 4, 4,7, 5, 5,4, 5,5, 7,11, 9, years to 10 years. Seven of the patients were females, four were males. The average age at the time of implantation was 69,4 years. Eight implantations corresponded to Miiller-Charnley hip TEP, three were "Kniehalbschlittenprothesen". The primary operation was made because of severe cox- or gonarthrose. For anchoraged of the protheses usual polymethylmethacrylate (PMMA) cement was used. The histological treatment based on the embedding in methylmethacrylate, undecalcefying sectioning and staintechnic specified by Burkhardt 1966 and Delling 1972 and 1980. Results. All specimens showed a strong increase of inactive osteoid on the bone-cement surface bordering. Additionally the appearance of a so called "Faserosteoid" and of none typical ossifying proceedings can be observed. These changes appeared most distinctly after 9 and 10 years of the prostheses implantation. One the strenght of the two studied specimen after 9 and 10 years implantation, we can not make a definite statement about a possible increase and deterioration. Discussion. According to Willert and Puls 1972 tissue reactions are terminating during the implantation which take place in three stages: First the implantation stage, secondly the regeneration stage and thirdly the stabilisation stage. According to their findings the stabilisation stage is reached at the latest after two years by the reparation proceedings of the bone bed. Morphometric tests on the skeletons of healthy people show a retarded secundary mineralisation in the sens of the "Altersmineralisationsstörung" with increasing tendency in the age group of 50-60 year-olds (Merz and Schenk 1970, Delling 1975). This already represents a bad start for bone reparation proceedings on older people. In our material there is morphologically a strong increase of inactive osteoid with isturbance of the regular mineralisation and the appearance of a so called "Faserosteoid". These changes might be attributed to local toxical influences caused by the cement or components of the cement like the aniline-blending Paratoluidine which could have an effect on the osteoblasts as well as on the proceedings of the mineralisation. Similiar increases of the osteoid are superficially mentioned by Willert and Puls 1972, 1974 A + B and Schuppler and Remagen 1976 and are believed to be a slow down of mineralisation. The formation of "Faserosteoid" as well as the appearance of atypical mineralisation proceedings have not yet been described as far as we know. These disturbances of mineralisation represent a loss of stabilisation of the bone-cement anchorage. At the punctiform overloading, lesions arise in this area, producing the growth of granulation-tissue which demolish the adiacent bone and result in the loosening of the prosthesis. The genuine aetiology of this disturbancy of mineralisation and a possible treatment or prophylaxy are object of additional investigation at the present time.

Limitation of temperature rise during embedding in methyl methacrylate by using a water cooled mould.

Limitation of temperature rise during embedding in methyl methacrylate by using a water cooled mould.

Vollautomatische Herstellung von Knochenschliffen bei exakter Dickeneinstellung

A new grinding machine for preparing thin undecalcified bone sections after methylmethacrylate embedding is described. About 20 rather small bone sections can be ground at the same time; bigger specimens, up to 8 cm of length, are allowed. Bone sections are mounted on a cylindrical specimen holder by an adhesive film. Then the final thickness of the sections is exactly adjusted by screwing three rubies out of the holder's bottom. Now the prepared holder is set in a guide ring on a turntable carrying a rough ended glass plate. The desired thickness of the sections is reached as soon as the three rubies touch the glass surface. The variation in the thickness of the sections is less than +/- 3 micron. The machine is simply constructed, easily to handle and rapidly to clean.

Methyl‐methacrylate as an embedding medium in histopathology

Methyl-methacrylate embedding makes it possible to obtain semi-thin sections rich in detail and without tissue shrinkage. The procedure requires considerable time and labour, and great care must be taken to prevent heat damage to the tissue during the exothermic polymerization process. The original method given by Burkhardt (1966) and later modifications are described and discussed, with special attention to the practical problems encountered and their solutions.

Fusion of particulate structure in polyvinyl chloride during powder extrusion

AbstractIt has been recognized recently that suspension polyvinyl chloride granules consist of particles ca 1μ in diam which are linked together to form a three‐dimensional, sponge‐like lattice. This paper deals with the fusion process of this particulate structure of PVC resin during powder extrusion. Extrudates prepared under various extrusion conditions are investigated through the electron microscope using a methyl methacrylate (MMA) embedding method followed by ultrathin sectioning. The MMA embedding method has been proven to be an effective means of revealing the detailed structure of molded PVC. Results showed that the 1μ‐particles were subjected to breakdown due to heat and shear into fibrils 100‐300 Å in thickness, which were the final structure attainable by extrusion. Discussion was focused on the fibrillar structure especially in relation to the elasticity in plasticized PVC.

A quick method for the preparation of teeth and bone as museum specimens by embedding in methyl methacrylate

A quick method for the preparation of teeth and bone as museum specimens by embedding in methyl methacrylate