Significant Difference In Numerical Density Research Articles

Presence of calcium in the vessel walls after end-to-end arterial anastomoses with polydioxanone and polypropylene sutures in growing dogs

The presence of calcium in the vessel walls after end-to-end arterial anastomoses performed with polydioxanone and polypropylene interrupted sutures was studied in 140 anastomoses in 35 10-week-old German shepherd dogs. Histologic examination with hematoxylin and eosin, van Gieson, and von Kossa staining techniques was performed after the animals were killed 6 months after the operation. Ketamine hydrochloride was used as an anesthetic agent. At the start of the investigation the dogs weighed 14.5 +/- 2.6 kg (mean +/- standard deviation, n = 35), and after 6 months they weighed 45.3 +/- 3.1 kg (mean +/- standard deviation, n = 35). The diameter of the sutured arteries in the first operation was 2.6 +/- 0.5 mm (mean +/- standard deviation, n = 140). With each dog, both brachial and both femoral arteries were used--one artery for each different type of suture. In different dogs, different arteries were used for the same type of suture. The prevalence of calcifications after 6 months was determined from the numeric density of calcifications with standard stereologic techniques. The sutured and sutureless parts taken from longitudinal sections from each artery were studied, and t test values were calculated as follows: In paired samples, statistically significant differences in numerical density of calcifications were seen between sutured and sutureless arterial parts for both materials (sutureless part versus part with polydioxanone sutures, p < 0.001, n = 70; sutureless part versus part sutured with polypropylene sutures, p < 0.01, n = 70); however, in independent samples no statistically significant differences in numerical density of calcifications were seen between the polydioxanone and polypropylene groups for sutured (p > 0.05, n = 70) and sutureless parts (p > 0.05, n = 70).

Staining of Merkel cells of pig snout epidermis using the uranaffin reaction: Morphometric analysis of neuroendocrine granules

The uranaffin reaction (UR) specifically stains neurosecretory (NS) granules of the neuroendocrine system when performed at pH 3.9 and at a 4% concentration of uranyl acetate. Merkel-cell NS granules stained using the UR were found to have a different appearance than granules observed after routine processing. We therefore compared the average values obtained with both methods, examining the maximum diameter, area, form factor, and numerical density of such NS granules. The maximum diameter and area of NS granules were significantly greater ( P < 0.001) in samples stained using a conventional technique (CT) (93.30 nm, 6,411 nm 2) that in those stained with the UR (63.95 nm, 2,148 nm 2). The form factor of conventionally stained NS granules (0.9) was significantly greater ( P< 0.001) than that of granules stained with the UR (0.7). No significant difference in numerical density was found for the two techniques (CT: 8.11 ± 2.51; UR: 6.14 ± 2.38). It was found that the UR is a useful cytochemical marker for NS granules of Merkel cells, and that the ultrastructural morphology and intracellular arrangement of NS granules stained with the UR are different from those revealed using CT.