On the ultrastructural level, anterior lens capsule allotransplants in mechanically induced corneal ulcer heal with continuously formed epithelial basement membrane and numerous hemidesmosomes. This enables significant reformation of hemidesmosomes that are identical in size to hemidesmosomes in healthy corneas and helps forming a stronger apposition for epithelial cells to underlying structures in eyes where epithelial basement membrane has been destroyed from chronic ulceration.

No abstract

We studied the effect of experimental hypodynamy on the structure of the two long bones (femur and tibiotarsus) of adult Japanese quail (Coturnix coturnix japonica) with special regard to osteoclasts. The quails were 70-day-old at the beginning of the experiment, they were euthanized after 28, 56, and 84 days of hypodynamy. Small pieces of bones were fixed, decalcified in EDTA, and routinely processed further for light and transmission electron microscopy. Structural changes in spongy bone and in the osteoclasts were found in all the experimental animals, compact bone was not affected. It seems that osteoclasts respond biphasically. First, after 28 days of hypodynamy, the number of osteoclasts diminished; they became vacuolated and had ruffled borders poor in microvilli. After 56 days of hypodynamy the osteoclasts recovered and became more numerous than in control animals; these osteoclasts possessed fully developed ruffled borders with many microvilli. After 84 days of hypodynamy the osteoclasts covered nearly the whole surface of the bone spicules and showed structural signs indicating their full activity.Japanese quail, experimental hypodynamy, osteoclasts, spongy bone, light microscopy, transmission electron microscopy

Early bovine precompacted embryos (1 to 8 blastomeres) were analysed by electron microscopy. The volume density of cellular components was determined by morphometric analysis to quantify the ultrastructure of early bovine embryos produced either in vivo or in vitro both after fertilisation by intracytoplasmic sperm injection (ICSI) or from electrically stimulated oocytes (AC/DC). In normal embryos obtained in vivo (control), most of the cellular volume was occupied by cytoplasm (82.93%). The relative volume of lipids, vacuoles, mitochondria, Golgi apparatus and inclusion bodies was minimal. In the group of embryos after parthenogenetic activation (AC/DC) a relatively high proportion of the volume was occupied by vacuoles and lipids (18.68% vs 14.33%). Early ICSI-derived embryos contained the lowest relative volume of cytoplasm (58.33%) compared with the control embryos (in vivo) and parthenogenetically AC/DC-activated embryos and a higher volume was occupied by lipids (13.25%) and vacuoles (12.92%). It is concluded that in vitro produced embryos have a significantly altered ultrastructure, indicating extensive cellular damage.

The effect of microgravity on functional development of the small intestine of Japanese quails incubated for 2-3 d and hatched on the orbital station MIR was examined. After 5 d of space flight duodenal and jejunal alkaline phosphatase (AP) activity of the experimental group was compared with the AP activity in quails of the same age hatched on the Earth (laboratory controls). Shortterm microgravity leading to decreased food intake resulted in significant increase of AP activity in both duodenal and jejunal enterocytes (P < 0.001) of the experimental quails. The results suggest that increased AP activity probably reflects the delayed functional development of the small intestine as a consequence of inapropriate food intake during non-physiological conditions of space flight. Microgravity, posthatch quail, alkaline phosphatase, food intake, fasting