مجله دانشکده پزشکی اصفهان
پیاپی 124 (هفته چهارم اسفند1389)

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.

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.

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.

P87 polyester seems to provide lighter and more flexible brain sheets compared with the standard method.

Various studies have shown that the risk of apolipoprotein-A (apo-A), B (apo-B), and trans fatty acids may be different for cardiovascular disease (CVD) events in different populations. This study aimed to estimate the relative risk of apo-A, apo-B, and trans fatty acids for the occurrence of cardiovascular disease events in a cohort study.

A cohort study was performed on 5375 subjects aged ≥ 35 years old participating in the Isfahan Healthy Heart Program (IHHP) that had been recruited with multistage cluster random sampling method. Apo-A and apo-B were measured in all subjects while trans fatty acids were measured on a random sample of 238 subjects. The relative risk of these factors for CVD events was defined in a 6-year period. T-test was used to compare means. Logistic regression and Cox regression were used to calculate Hazard ratio of cardiovascular disease events.

After adjustment for age and sex, the relative risk for cardiovascular disease events was 2.393 (95%CI 1.155-4.961) for apo-B/A, 1.007 (95%CI 1.004-1.009) for total cholesterol, 1.002 (95%CI 1.001-1.003) for triglycerides, and 1.008 (95%CI 1.005-1.010) for LDL-cholesterol. After adjustment for smoking, diabetes, hypertension, and obesity, the relative risk for total cholesterol (1.006, 95%CI 1.003-1.008) and LDL-cholesterol 1.007, 95%CI 1.004-1.010) was significant while insignificant for trans fatty acids.

This study showed that relative risk of apo-B/A for cardiovascular disease events is similar to total cholesterol and LDL-cholesterol. However, after adjustment for other risk factors, the association remained significant only for total cholesterol and LDL-cholesterol. Trans fatty acids did not show significant risk for cardiovascular disease event.