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PubMedDate not supplied

Plastination of whole brain specimen and brain slices.

BACKGROUND: The human dead body specimens are plastinated for teaching purposes in medical institutions, using silicone. The silicone impregnated whole brain specimens and brain slices do not give satisfactory results. METHODS: In the present study the brain specimens were plastinated with another polymer known as Polyester-Copolymer. The brain specimens were first preserved and then fixed with 5% formalin. The specimens were then dehydrated and degreased in a volatile solvent acetone. The specimens were placed in Polyester-Copolymer solution which penetrated the brain tissue both intracellulary and intercelluraly. The specimens were then cured by gas method. RESULTS: The whole brain specimens and brain slices plastinated with Polyester-Copolymer were dry, odorless, handy and durable. It also gives a clear visual contrast between grey and white matter in brain slices whereas the brain specimens plastinated with silicone are flexible and sticky. There was no color contrast between grey and white matter. CONCLUSION: The polyester impregnated brain specimens and slices are non-toxic and ideal for teaching purposes and examinations. They require minimal aftercare. The whole organ serial sections of plastinated brain specimens will help 3-dimensional study of the normal brain and will improve the assessment of brain pathology.

Brain↗
PubMed2002

A new technique for hard tissues.

Fossil tissues generally require specialized processing. Most thin sectioning techniques yield unstained sections or require unwieldy methods to produce stained sections. I outline here two simple techniques for producing stained, ground, thin sections using readily available Romanowsky-type cytology stains and a urine sediment stain. Results are comparable to hematoxylin and eosin stained specimens.

Animals↗
PubMed2002

Histologic and radiographic assessment of caries-like lesions localized at the crown margin.

STATEMENT OF PROBLEMS: Little is known about the impact of crown margins on the demineralization and remineralization process or on the interpretation of radiographs for the detection of early secondary caries. PURPOSE: The aim of this study was to correlate the findings from 2 different radiographic techniques with the results of a histologic assessment of carieslike lesions at the crown margin. MATERIAL AND METHODS: Ten fully impacted third molars were extracted and restored with complete metal crowns with chamfer preparations. For each tooth, the prepared margin ended in enamel on one side and extended into cementum/dentin on the other. After being thoroughly cleaned, the teeth were covered with wax except for a 2- x 3-mm window at the crown margin in each of 2 test areas localized at the interproximal enamel and cementum/dentin junction. During demineralization with 6% hydroxyethyl cellulose gel at pH 4.9, direct digital radiographs or conventional radiographs were made at baseline and after 7, 14, 21, and 28 days. Each radiograph was blinded and examined for the presence/absence of lesions by 3 calibrated observers who used predetermined criteria required for receiver operating characteristic (ROC) analysis. After 28 days, the teeth were imbibed with methyl methacrylate and serially ground sectioned for assessment of the lesions in polarized light. Morphometric analysis of lesion extension included the calculation of mean values and standard deviations. Kappa and ROC analysis were applied to assess radiographs made at different demineralization time periods, localization of the crown margins in enamel or cementum/dentin, and direct digital and conventional radiographs. Data were tested for normal distribution (QQ plot), and statistical differences were calculated with Tukey's honestly significant difference post hoc test. RESULTS: Radiographic evaluation revealed only slight interexaminer agreement (Kappa) for enamel lesions (direct digital 0.19, conventional radiographs 0.2) and a fair interexaminer agreement for cementum/dentin lesions (direct digital 0.35, conventional radiographs 0.33). ROC analysis revealed no differences between the radiographic techniques. Lesions localized in cementum/dentin (direct digital 0.86 +/- 0.14, conventional radiographs 0.86 +/- 0.09) were diagnosed more reliably than those in enamel (direct digital 0.79 +/- 0.05, conventional radiographs 0.72 +/- 0.10). As microscopically assessed, the depth of lesions in enamel was less than that of lesions in cementum/dentin (49.3 +/- 7.3 microm vs 89.5 +/- 13.2 microm). Erosions were found in cementum/dentin (depth 25.2 +/- 5.3 microm). CONCLUSION: Within the limitations of this study, small artificial lesions were detected equally well by conventional and direct digital radiography. However, because of low interexaminer agreement, the radiographic assessment did not reproduce true histopathologic lesion characteristics documented by morphometry of serial ground sections.

Adolescent↗
PubMedDate not supplied

[Skin layer thickness at the ear of the domesticated pig , with special reference to the use of the ear integument for human dermatological research].

Based on a shrinkage-free methodical approach (special plastic resin embedding, frozen section technique) and histological routine staining, the thickness of the different skin layers was measured from 15 regions of the outer and the inner side of the porcine auricle. Mean thickness values were for the str. corneum: 19 microns outside/20 microns inside, vital epidermis without ridges: 52 microns outside/56 microns inside, dermis: 1175 microns outside/1112 microns inside, hypodermis: 1024 microns outside/741 microns inside, perichondrium: 295 microns outside/220 microns inside. When both sides of the auricle were compared, it became obvious that the outer side generally had a thicker dermis (1140-1290 microns) and hypodermis (780-1150 microns), whereas the inner side had a thicker vital epidermis (50-60 microns) and deeper epidermal ridges (145-165 microns). The results are discussed with regard to corresponding findings from the human skin, and one region of the outer side of the porcine auricle is recommended as suitable for human dermatological research.

Animals↗
PubMed2002

[Study about proliferation and apoptosis of megakaryocytes in patients with myelodysplastic syndromes].

In order to observe the proliferative and apoptotic situation of megakaryocytes in patients with myelodysplastic syndromes (MDS). CD41 immunoenzyme labeling (alkaline phosphatase anti-alkaline phosphatase APAAP)/DNA in situ end labelling (ISEL) double stained techniques was used onto plastic cold embedded bone marrow sections in 29 MDS patients to analyse the proliferative and apoptostic characterization of megakaryocytic line with 14 cases of iron deficient diseases (IDA) as control. The results showed that the mean CD41 positive cell number in MDS group was (26.23 +/- 8.18) /mm(2) with a count of (15.64 +/- 7.11) /mm(2) in control group (p < 0.05). The small-micro megakaryocytes in MDS is much higher than that in IDA group (P<0.01). There was a positive co-relation between total megakaryocytes and small-micro megakaryocytes count in MDS (r = 0.702, p<0.01). Some megakaryocytes distributed abnormally around trabecula and formed small or large clusters. Apoptotic megakaryocytes in MDS occupied 4.40% and 9.32% of all CD14 positive cells and all apoptotic cells respectively (p > 0.5 comparing with control). Apoptosis in megakargocytic line occurred only in small-micro megakaryocytes and showed positive co-relation to the number of micro-megakaryocytes. Some apoptotic cell with morphologic characters of megakaryocytes expressed no CD41. It is concluded that overproliferation of megakaryocytes exists in MDS. Apoptosis occurring in micro-megakaryocytes may be a kind of physiological response to abnormal megakaryopoicsis in MDS. No obvious increased apoptosis of megakaryocytes in MDS was found perhaps due to lack of surface antigens CD41 in some later stages of apoptotic cell.

Adolescent↗
PubMed2003

Method for immediate measurement of in vitro bond strength of bonded direct esthetic restorations.

There are many different ways to measure the bond strength of direct esthetic restorations to various dental substrates. Unfortunately, most methods cannot measure bond strengths immediately after a restoration has been placed. This lack of clinically-relevant information seriously affects the clinician's ability to select and use various bonding agents and procedures. The aim of this article is to provide a very detailed method for immediate measurement of in vitro bond strengths of direct bonded esthetic restorations. It focuses on the steps that should be taken to select and prepare various tooth substrates for bond strength testing, the steps to "restore" various tooth substrates, and to measure the immediate in vitro bond strength. A fundamental understanding of a standardized testing protocol should provide clinicians with a clearer appreciation of bond strengths associated with various bonding procedures.

Dental Bonding↗
PubMed1992

The arterial pattern and fractal dimension of the dog kidney.

A method has been developed by which it is possible to measure the fractal dimension of the arterial tree of the kidney. The objective of this work is to determine a method which permits us to discriminate between the architectures of specific organs by reference to a unique number, namely the fractal dimension of the arterial tree of that organ. This method opens the possibility of a new taxonomy for normal organs and for the pathological injiries related to the vascular morphology of those organs. The method that we have devised uses as its input the volume which is taken up by the arterial tree of the kidney. In order to calculate this volume we first obtained a plastic cast (the arteries were filled with Araldite CY233 plastic resin after which the organic tissues were corroded); thereafter we constructed a theoretical arterial tree having the same volume as the renal one. From this simplified tree, we were able to calculate its fractal dimension. The complete process of constructing the theoretical arterial tree and the subsequent calculation of its fractal dimension was carried out automatically by way of a computer programme to which we have given the name fractal program.

Abdomen↗
PubMed2005

Undecalcified bone samples: a description of the technique and its utility based on the literature.

The evaluation of bone regeneration and peri-implantary bone apposition requires laboratory techniques that allow the evaluation of hard tissues without needing to decalcify them. In this study, we describe the cutting-grinding procedure (EXAKT system) for obtaining samples of undecalcified bone and aim to establish the procedures for their histological and histomorphometric evaluation. A review is made of the literature on histological and histomorphometric evaluation using undecalcified samples in surgical and oral implantology procedures in which bone regeneration or bone apposition is produced on the dental implants. The technique is a lengthy process, and is principally indicated in the investigation of bone biology. The use of undecalcified samples allows the differentiation of immature from mature bone, and the quantification of variables such as the bone-implant interface, the density of the bone area and the speed of bone apposition.

Animals↗
PubMed2005

[Juguler vein gunshot injury from blank cartridges].

Blank cartridge guns, which are produced for self-defence needs and considered harmless, can be easily purchased by adults due to lack of legal regulations. We present this case because injuries caused by gunshot from blank cartridges may be fatal and are rarely encountered in emergency departments. A 3-year-old boy was brought to the emergency department since he had a wound on his neck caused accidentally by gunshot from blank cartridges. He had a moderate general condition and pale appearance. There was an irregular-edged, defective wound 2 cm above the sternal notch in midline localization with a dimension of 3 x 4 cm. Computed tomography of the thorax revealed contusion in the apex of the left lung. A 2-mm plastic piece embedded in the left internal jugular vein was removed during the operation. A mass education on danger and harm of these guns as well as legal regulations for restricted use seem to be necessary. Also, physicians should keep in mind that blank cartridge guns can cause fatal injuries.

Child, Preschool↗
PubMed1992

[The temporal bone].

Imaging of the temporal bone by high resolution CT scan has become more and more accurate in recent years. Coronal slices are particularly important. We present the anatomy of four temporal bones embedded in plastic material. Coronal sections with a thickness of 2 mm were taken, radiographed and their density measured. Particular interest was given to the three-dimensional relations as well as to the density of bone of important morphological structures such as the labyrinth, middle ear, facial canal, sigmoid sinus, carotid canal and the mastoid. A low density of bone corresponds to the colour blue, a high density to black. Because of the high resolution of the method it was possible to image small and fine structures such as the auditory ossicles, and the perilymphatic and endolymphatic ducts. A three-dimensional reconstruction may well be possible in the future, and the possibilities of this method are discussed.

Carotid Artery, Internal↗
PubMed2006

Histopathologic evaluation of aneurysms treated with Guglielmi detachable coils or matrix detachable microcoils.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the degree of organization and fibrocellular tissue development in aneurysms treated with bare platinum or biologically active microcoils. METHODS: Twelve aneurysms were removed at autopsy between 1-18 days and another 2 between 2-3 months posttreatment. Four aneurysms were surgically removed between 6 months and 3 years following treatment. One aneurysm removed at 8 days and another at 6 months were treated with bioactive (Matrix) coils; the other 16 with bare platinum (Guglielmi detachable coils; GDCs). All specimens were embedded in plastic, stained with hematoxilin-eosin and elastin and examined by light microscopy. RESULTS: All specimens removed within 3 weeks demonstrated intra-aneurysmal thrombus, without signs of organization or fibrotic tissue formation over the neck regardless of the type of coils used. In the GDC-treated aneurysms, evidence of early thrombus organization was observed within 2-3 months, and completed yet imperfect fibrocellular reaction together with residual thrombus at 2-3 years. In the Matrix-treated specimens, the aneurysm cavity was completely filled with granulation tissue corresponding to still ongoing fibrocellular reaction at 6 months, including newly formed blood vessels, smooth muscle cells, and collagen deposition without signs of residual thrombus. CONCLUSIONS: Our results indicate that in aneurysms treated with bare platinum coils thrombus organization does not occur until late after treatment and may remain imperfect for years. In one aneurysm studied 8 days following treatment with Matrix coils, no difference was noted compared to aneurysms treated with bare platinum coils. In another aneurysm examined 6 months following packing with Matrix coils, the histologic changes support the hypothesis that the biologically active polymer may accelerate aneurysm healing.

Adolescent↗
PubMed2006

[Hepatosplenic gammadelta T cell lymphoma and its relationship with Epstein-Barr virus infection].

To explore the clinical and pathological characteristics of hepatosplenic gammadelta T-cell lymphoma and its relationship with Epstein-Barr virus infection, the clinical features of a 9-year-old girl with hepatosplenic gammadelta T-cell lymphoma were investigated, the smears of bone marrow was stained with Wright' s stain, biopsies of bone marrow and liver specimen were embedded in plastic and sliced about 4 microm in thickness and routinely stained with HE staining, the immunohistochemical staining was used to mark the tumor cells, and EBER probes were used to detect Epstein-Barr virus RNA. The results showed that the girl presented with prolonged fever, anemia, thrombocytopenia, hepatosplenomegaly, chronic active Epstein-Barr virus infection, and elevated levels of serum ferritin and lactate dehydrogenase. Bone marrow aspirate revealed the infiltration of atypical lymphocytes in the bone marrow stroma. The liver biopsy specimen revealed the infiltration of lymphocytes in the sinusoids, which was positive for the T-cell associated marker CD3 and activated cytotoxicity-associated marker granzyme B. In-situ hybridization analysis with EBER probes revealed that the above-mentioned characteristics were negative in neoplastic cells. It is concluded that hepatosplenic gammadelta T-cell lymphoma is a disease with distinctive clinical, histopathologic, and phenotypic characteristics. Hepatic and/or splenic and/or bone marrow biopsy with combined phenotype is beneficial to diagnosis. Epstein-Barr virus infection is late event involving an already transformed gammadelta T-cell clone.

Child↗