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Background: Plastination is a new method of preserving tissue samples for a long time. This study aimed to compare the new plastination technique with the conventional preservative method in glycerin for fetus skeleton tissues and young rats dyed by Alizarin red- Alcian blue double staining. Materials and Methods: In this study, 4 groups of 1-day, 3-day, 12-day and mature rats were selected and, after being anesthetized and slaughtered, their skin was completely removed. In Alizarin red- Alcian blue double staining method, first the samples were fixed in 95% ethanol and then their cartilages were dyed by 0.225% Alcian blue solution; after that, they were cleared in 1% KOH. Then, the bones were dyed in 0.003% Alizarin red solution and finally the tissue was decolorized in 95% ethanol. In each group, half of the samples were preserved by the conventional method in a glycerin container and the other half were plastinated. Results: In the present study, the samples preserved by plastination technique were dry, odorless, indecomposable and tangible. Quality of coloring had an inverse relationship with rats′ age. Transparency of the plastinated samples had also an inverse relationship with rats′ age. Therefore, skeletal tissue of younger rats had higher quality and transparency in both preservation methods (glycerin and plastination). Conclusion: This study showed that plastination technique was an appropriate method in comparison with glycerin preservation, which conserved skeletal tissue of fetus and young rats colored by Alizarin red- Alcian blue double staining. And the final result was that plastination technique can generate dry, odorless, indecomposable and tangible samples.

Introduction: Plastination is a technique of long-term preservation of the natural tissues without the typical problems related to wet specimens. Plastinated specimens are durable, dry, and flexible. In this process, the water and fat in biological tissues are substituted by a curable polymeric resin, i.e., subsequently cured. In this study, a new unsaturated polyester resin (P96) was synthesized and formulated to improve plastination techniques. These approaches were applied in the plastination laboratory at Isfahan Medical School based on our previous synthesized resin (P87) and the commercial resin (P35). Methods: P96 was formulated using different polyols, saturated, and unsaturated poly-acids, as the ploy esterification monomers. Then, the resulted pre-polymer was cured by the reaction of a vinyl monomer (hardening agent) in the presence of a radical initiator (hardening promoter) to form a tough durable film. The components of the resin were finely tuned to achieve the desired properties for organ plastination. Then, forced impregnation in a vacuum chamber was performed in the presence of P96 at 25oC following the conventional protocol, fixation, slicing (if necessary), dehydration, and defatting (if necessary). Finally, the curing (hardening) of P96 specimens was achieved by UVA-light irradiation. Results: According to the mechanical test results, P96 presented higher tensile strain and flexibility than P35 and P87. P87 had higher bending capability, compared to P35 and P96. P96 specimens were lighter, compared to P35 and P87 specimens. P96 specimens were more odorless than P87 specimens. In the naked survey of specimens, P96 specimens presented a better appearance concerning natural color and texture for plastinated specimens as well as the resin uniformity, consistency, and transparency of cadaveric tissues. Conclusion: The current study introduced a novel plastination method using a new formulated resin, P96. This technique is a quick and less expensive method for producing sheet as well as bulk plastinated specimens of different organs, i.e., appropriate in teaching anatomical sciences. P96 can be considered an upgraded resin, i.e., transparent and flexible with an easy and controllable hardening process. It has resolved the deficiencies of previous polyester resins.

Background: Hepatitis B is one of the major causes of mortality among viral diseases. To reduce morbidity rate and increase knowledge of people about potential risk factors, the aim of this study was to determine the prevalence of hepatitis B among the general population and the risk factors associated with hepatitis B virus (HBV) infection in Isfahan, Iran. Materials and Methods: In a case–control study, 314 HBV-infected patients and 557 healthy participants were recruited. Data on demographics, immunization history, medical history, family medical history, life history, therapeutic factors, and behavioral risk factors were collected through a standard checklist. Chi-square and logistic regression were used for univariate and multivariable analyses. Results: Our results showed that among sociodemographic variables, higher age, being male, lower economic status, and lower educational attainments increased the risk of affecting by HBV (odds ratio [OR] >1, P < 0.001); furthermore, Iranian and no immigrant people showed higher significant risk of being affected by HBV. Multivariable logistic regression showed among medical, blood, and behavioral risk factors, family history of hepatitis (OR: 10.56; 95% confidence interval [CI]: 4.56–24.86), dental treatment history (OR: 4.30; 95% CI: 1.41–13.10), and hospitalization (OR: 2.94; 95% CI: 1.72–5.00). Conclusion: Our results demonstrated that there are still several risk factors for hepatitis B surface antigen infection among the Iranian adult population. Immunization programs should continue and focus on high-risk adults, and interventions should be directed toward to reduce risk factors associated with hepatitis B.

Background: Plastination is an excellent technique which helps preserve biological specimens in a dry, odorless, and state. In this technique, water and fat are extracted from tissues and are replaced with curable polyester. Previously prepared plastinated sheets of human brain were fragile and heavy (standard method). The aim of this study was to prepare flexible and light plastinated sheets of human brains. Methods: Two intact human brains were prepared and fixed in 10% formalin for 3 months. After. They were sliced into 3 mm thickness sheets and were dehydrated by acetone in -250C for 4 weeks. Then, the slices were impregnated by P88 flexible polyester in the vacuum chamber. Finally, each slice was cast in an individual flat chamber consisting of 2 standard glass plates by P87 flexible polyester. The transparency, weight, flexibility, bubbling and Gross fragility of the prepared sheets were compared with those of the standard method. The transparency was measured by photometer machine. Their weight was assessed by digital scale; Gross fragility and bubbling were assessed by direct observation. Flexibility of samples was investigated by the degree of bending zero to 45, 45 to 90, 90 to 135 and 135 to 180 degrees of bending were scaled 1, 2, 3 and 4, respectively. Finding: Average light passing, flexible sheets was 85%, while in standard method was 90%. The weights of flexible sheets were 200-400 gr, and in standard method were 600-800 gr. Bubbling and gross fragility were observed in standard method, while no bubbling and gross fragility were observed in flexible sheets. The average flexibility of flexible sheets was, while in standard method was 1. Conclusion: P87 polyester seems to provide lighter and more flexible brain sheets compared with the standard method.

Background: Anatomists had been searching to find methods for preserving soft human tissues and produce natural samples with durable, dry, odorless, and portable in briefcase properties. Plastination is a modern method for preparing such tissue samples. In plastination, water and fat are extracted from tissues and replaced with a dissolver fluid, which in its turn is replaced with a special kind of polyester. Usually, the organs like hearts, lungs, kidneys, striated muscles, vessels, nerves, connective tissue, etc, which are treated with formalin, loss their beautiful color and take a dull appearance after fixation. Tissue staining with natural dyes is one method for somehow preserving tissue natural color and increasing its appearance activity to prepare better samples in terms of appearance and suitable clearance of different parts (valves, muscles, trabeculae…). Also, we have to prepare non fragile samples. Methods: At first, some visceral organs (sheep hearts) were prepared and fixed by formalin 5% for 4 to 10 days. Then they were dissected for anatomic details and were put in a chemical dye called eosin and natural dye called ronnas. After dehydration by acetone in -25 °C and defeating with acetone in +30 °C, samples were put in the vacuum chamber to replace acetone instead of polymer under the vacuum pressure; finally the samples were cured with the ultra violate wave. Findings: We found that after fixation and before plastination staining of organs with eosin and ronnas resulted in beautiful appearance of tissues. Conclusion: Staining of organs resulted in beautiful appearance of tissues which are effective in increasing the attractively of teaching and learning anatomy. Also, it has affection in the raising appearance quality and has positive impression in the quality of education. Keywords: Plastination, Natural dye, Industrial dye, Polyester.

Introduction: Plastination is a unique technique for preservation of biological specimens used for teaching purposes. The protocol of flexible sheet plastination includes fixation, slicing, dehydration, force impregnation, casting, and curing (Hajian, Rabiei, Fatollahpour & Esfandiary, 2008). The procedure is done by using P87 flexible unsaturated polyester resin and provides heavy, gross, fragile, and bubbling plastinated sheets. In this study, synthetic resin (P89) in the plastination laboratory at Isfahan Medical School is utilized with a new method for plastination of 3-mm human’s brain slices without casting stage. Also, common plastination method with the use of P87 flexible resin was used and the products were evaluated and compared in the laboratory with new method products. This method is also compared with specimens made by P35 resin sandwich method. Methods: This study was carried out on 3 human brains. Initially, according to the conventional methods, the brains were fixed in 10% formaldehyde, cut sagitally, coronally, and horizontally into 3-mm thickness slices by meat slicer, and then dehydrated in cold acetone (-25°C) and immersed in P89 unsaturated polyester resin at 25°C. Finally, the specimens were taken out from vacuum chamber and exposed to room temperature. When both surfaces of specimens became dry, they were taken to P89 polyester resin pail again. We repeated this stage 10 times. Results: P35 specimens had high tensile strength compared to P89 specimens. Also P89 specimens had high bending capability compared to P35 specimens made by sandwich method. Likewise, P89 specimens were lighter compared to P35 specimens. In the naked survey of specimens, P35 specimens with white spot in the tissue indicate discoloration for plastination of brain specimens without casting stage. Conclusion: Our study showed that P89 technique is a cheap, quick, and less expensive method for producing sheet plastinated specimens which are suitable in teaching neuroanatomy.

Background: The scope of this study was to preserve whole detailed structure of dissected and decalcified bones, taken from used cadavers, by a new plastination technique. Materials and Methods: Specimens we used in this study were sheep femurs and human bones including pelvis, femur, tibia, and fibula. Bones, at first, fixed with 5% formalin and were decalcified with 5% nitric acid, and then were fixed again and washed under the tap water. The resulted flexible bones were dehydrated in -25΀C acetone and degreased them in +25΀C acetone. Then, the experimental and control specimen were placed in the vacuum chamber for forced impregnation with our new flexible unsaturated polyester resin (UP 89 method) and silicon resin (S 10 method), respectively. Finally, the strength and flexibility of plastinated decalcified specimens were investigated by tensometer, and the weight diversity was measured by digital balance. Results: Plastinated bones prepared by this technique were found to be dried, non-fragile, durable, odorless, non-greasy, and demonstrating all detailed structures of the bones. Tensile and weight tests results indicated that plastinated decalcified femurs have owned higher flexibility and strength but lesser weight than plastinated undecalcified femurs. The characteristics of both experimental and control groups of plastinated decalcified specimens were found to have no significant difference. Conclusions: Our synthesized resin found to be much more economical than conventional plastination method. In more details, properties of these new products were the same as, S 10 method, from points of strength, flexibility and weight, but, since the money cost for producing them was about one fifth that of S 10 method.