Dynamics of reepithelialisation and penetration rate of a bee propolis formulation during cutaneous wounds healing.

The aim of this work is to investigate the dynamics of reepithelialisation and the penetration rate of a propolis ointment formulation during cutaneous wounds healing. The experiments were performed as a function of the treatment time in a well controlled group of rats. We observed that the propolis ointment influenced the healing process stimulating keratinocytes cell proliferation as compared to the control group. It was shown that the propagation of the bee propolis was dependent on the wound healing stages. In addition, the photoacoustic spectroscopy showed that the applied substances reached the deep wound region, highlighting once again the particular characteristic of this technique to evaluate the penetration rate of substances through the skin.

Testis differentiation in the glowworm, Lampyris noctiluca, with special reference to the apical tissue.

The gonads of Lampyris noctiluca are sexually undifferentiated during the first larval instars. They consist of many gonadal follicles that include the germ stem cells enclosed by the somatic cells of the follicle wall. Follicle wall cells are more numerous at the follicle apices than at the distal parts, but different cell types cannot be distinguished. In male larvae, the appearance of apical follicle tissue, derived from follicle wall cells, marks the onset of testis differentiation. When maximally expressed, the apical tissue occupies about the upper half of the testis follicles and can be observed in larvae of the fifth and sixth instar. The apical tissue is characterized by its "light" appearance (due to poor stainability) caused by the small number cellular organelles, especially a paucity of free ribosomes. Maximal expression of the apical tissue must be very brief, since in most examined fifth and sixth instar larvae the apical tissue is partly or mostly translocated into the center of the upper half of the follicles and spermatogonia then occupy the apical follicle tips. During and after translocation apical cells form projections that grow around clusters of spermatogonia (spermatocysts). Thus, the apical cells transform into spermatocyst envelope cells. They retain their "light" appearance but undergo dramatic subcellular differentiation: smooth ER becomes extremely prominent, forming stacks and whorls of parallel cisternae. Golgi complexes are also conspicuous. The cellular organization suggests secretory activity. The possibility of ecdysteroid production and its function is discussed. The spermatocyst envelope cells persist into the pupal stage. When spermiohistogenesis takes place in cysts, cyst envelope cells show signs of regression. At all stages of testis development apical cells and their derivatives, the spermatocyst envelope cells, phagocytize degenerating spermatogonia. Although this is an important task of these cells, the impressive formation of sER in the cyst envelope cells is indicative of an additional, as yet unknown, function.

Ergastoplasmic paracrystalline inclusion bodies in the adipose gonadal envelope and fat body of the glow worm, Lampyris noctiluca (Insecta, Coleoptera).

The gonads of glow worm larvae are enveloped by adipose tissue which represents a specialized fat body. The adipose gonadal envelope, and also to a lesser extent the fat body cells, contain tubular paracrystalline inclusion bodies (PIBs). Cells of other tissues are devoid of such inclusions. The PIBs form in the cisternae of rough ER. In young larvae PIB formation is sparse, but at advanced larval stages PIBs often occur as bundles in stacks of ergastoplasm. Typically, a PIB within a cisterna consists of four to seven parallel tubules. The outer diameter of a tubule is ca 28.8 nm and the width of the tubule lumen ca 12.2 nm. The "wall" of a tubule contains globular protein subunits of ca 8.3 nm diameter; the subunits are arranged helically. Since the adipose gonadal envelope progresses through a cytological differentiation process during differentiation and maturation of the gonads, the increased number of PIBs may indicate enhanced metabolic activity of the tissue related to nutrition of the growing gonads.