cytological techniques

Primordial germ cells develop into oocytes and sperm cells. These cells are useful resources in reproductive biology and regenerative medicine. The mesenchymal stem cells (MSCs) have been examined for in vitro production of primordial germ cell-like cells. This study aimed to summarize the existing protocols for MSCs differentiation into primordial germ cell-like cells (PGLCs). In the limited identified studies, various models of mesenchymal stem cells, including those derived from adipose tissue, bone marrow, and Wharton's jelly, have been successfully differentiated into primordial germ cell-like cells. Although the protocols of specification induction are basically very similar, they have been adjusted to the mesenchymal cell type and the species of origin. The availability of MSCs has made it possible to customize conditions for their differentiation into primordial germ cell-like cells in several models, including humans. Refining germ cell-related signaling pathways during induced differentiation of MSCs will help define extension to the protocols for primordial germ cell-like cells production.

Following loss of teeth, atrophy of alveolar ridge of the jaws is a substantial problem and unintended outcome that compels clinicians to perform bone reconstruction ahead of implant placement. Although autogenous bone is recommended as the gold standard in bone reconstruction, aninvasive second surgery harvestinga limited volume of bone (from intraoral source) has led a significant approachingthe use of synthetic bone substitute materials. The aim of this study was to evaluate the histologic and histomorphometric properties of porous titanium granules (Natix®) used in horizontal reconstruction of alveolar ridge before implant placement.
In the present quasi-experimental clinical trial, four patients (three females and one male) needed horizontal bone augmentation on ten areas of edentulous mandibular ridge before implant treatment. During surgery, the buccal aspect of edentulous ridge was augmented by NatixÒ, covered by resorbable membrane (CytoplastÒ). After 8 months, 10 core biopsies were obtained.
In histological study, no foreign body reaction at the site of the newly formed bone or around the biomaterial residue was observed. Newly formed bone was fully vital with large lacunae containing osteocytes. In 60% of cases, connective tissue was observed at the biomaterial – new bone interface. In histomorphometric study, mean percentage of bone formation was 40.56% ± 19.83% and mean bone trabecular thickness was 39.98 ± 17.54 µ.
Despite acceptable histological and histomorphometric bone formation findings, in clinical terms, no increase was created in the horizontal dimension. Thus, it seems that application of this biomaterial in horizontal reconstruction of alveolar ridges with noncontained defects is inappropriate.