Effect of the method of agitation on the accumulation of protective antigen in cultures of Bacillus anthracis.
Accumulation of protective antigen was essentially independent of culture volume, provided the organisms were kept in suspension by stirring. Agitation by orbited shaking was unsatisfactory.
DNA Fingerprinting of Parent Stocks and the Progenies Produced Under Different Salinity Acclimation of Chlorella sp.
Chlorella sp. is a unicellular green alga which belongs to the division of Chlorophyta. It is one of the oldest living organisms on earth and can be found in freshwater and seawater. This alga is very important for aquaculture industry and medicinal properties in human serum and food as well. In this research Chlorella were grown in two different cultured conditions (aeration and agitation) under different salinities (0, 10, 20, and 30 ppt) of artificial salt water as the cultured media. For culturing purposes, it is important to know the level of genetic biodiversity among the culturing populations as well as the level of heterozygosity of each progeny. The level of genetic diversity of this species is required for purposes of management, quality control, conservation, and mass alga production. Four RAPD primers (OPA-02, OPA-03, OPA-04, and OPA-13) were employed using the RAPD technique to determine the species genetic divergence level and to analyze the degree of polymorphism in Chlorella. The RAPD analysis shows that the genetic distance among culture population in different salinities was 19–81 %, while that of parent and progenies produced was 73 and 62 %, respectively, for aeration and agitation. This shows that the genetic distance between parent and progeny by agitation was closer compared to the genetic distance between parent and progeny cultured by aeration method and indicates that agitation is more pure than aeration. As a conclusion, the genetic diversity of the Chlorella culture found in different subcultures changes over time because of the adaptation or response of unicellular microalgae to different culture conditions and contamination with other microalgae.
Endodontic regeneration: hard shell, soft core
A loss of organs or the destruction of tissue leaves wounds to which organisms and living things react differently. Their response depends on the extent of damage, the functional impairment and the biological potential of the organism. Some can completely regenerate lost body parts or tissues, whereas others react by forming scars in the sense of a tissue repair. Overall, the regenerative capacities of the human body are limited and only a few tissues are fully restored when injured. Dental tissues may suffer severe damage due to various influences such as caries or trauma; however, dental care aims at preserving unharmed structures and, thus, the functionality of the teeth. The dentin–pulp complex, a vital compound tissue that is enclosed by enamel, holds many important functions and is particularly worth protecting. It reacts physiologically to deleterious impacts with an interplay of regenerative and reparative processes to ensure its functionality and facilitate healing. While there were initially no biological treatment options available for the irreversible destruction of dentin or pulp, many promising approaches for endodontic regeneration based on the principles of tissue engineering have been developed in recent years. This review describes the regenerative and reparative processes of the dentin–pulp complex as well as the morphological criteria of possible healing results. Furthermore, it summarizes the current knowledge on tissue engineering of dentin and pulp, and potential future developments in this thriving field.