Simultaneous detection and evaluation of Prevotella intermedia, Prevotella nigrescens, Prevotella loescheii, and Prevotella melaninogenica in subgingival plaque samples of chronic periodontitis and healthy individuals through multiplex polymerase chain reaction.

Background: Prevotella is a Gram-negative anaerobic bacilli. The phenotypic characteristics of the various species of Prevotella are similar, which often makes it difficult in routine differentiation and identification of all the species. Aim: The purpose of the study was to detect and compare presence of Prevotella intermedia, Prevotella nigrescens, Prevotella melaninogenica, and Prevotella loescheii in subgingival plaque samples of chronic periodontitis and healthy individuals. Materials and Methods: Two hundred and thirty-six subjects were considered consisting of chronic periodontitis (128) and healthy (108) individuals. Subgingival plaque sample was collected in reduced transport fluid and analyzed. DNA extraction and polymerase chain reaction (PCR) were performed for genus Prevotella followed by positive samples were considered for the detection of selected species through multiplex PCR using specific primers. Results: Out of 236 samples, 94.1% were positive for genus Prevotella. Out of 222 cases P. nigrescens showed the highest number of cases positive (59.5%) followed by P. melaninogenica (57.2%), P. intermedia (55.4%), and P. loescheii (40.1%). Species were analyzed individually between chronic periodontitis and healthy, P. intermedia, P. nigrescens, and P. loescheii showed greater positivity in healthy compared to chronic periodontitis. Positivity for P. melaninogenica was high in chronic periodontitis compared to healthy. Conclusion: The number of positive cases for species, when correlated with clinical parameters showed an increase in mean score for all clinical parameters assessed, suggesting the presence of variation in the prevalence of Prevotella species and geographic variation do exist in oral microflora. Findings suggest that they can be normal commensals and opportunistic.

Regeneration of periodontal ligament fibers around mini dental implants and their attachment to the bone in an animal model: A radiographic and histological study.

Background: Tissue-engineered periodontal ligament (PDL) around a dental implant by using PDL stem cells (PDLSCs) may be useful in periodontal regeneration and can reduce or eliminate certain shortcomings of dental implants. Materials and Methods: PDLSCs were isolated from extracted human PDL cells and cultured in a bioreactor. They were identified using markers CD45, CD73, CD90, CD105, and CD146. After the formation of multiple cellular layers, they were then attached on titanium mini dental implants and placed in rabbit tibia. The rabbits were sacrificed after 9 months, and the implants were analyzed histologically and radiographically by Cone beam computed tomography (CBCT). Results: Isolated PDLSCs obtained from human premolars showed a colony-forming ability on the 7th day and 14th day. Immunocytochemistry revealed that cells had taken up the adequate positive stains for primary antibodies CD73, CD90, CD105, and CD146 and negative staining for CD45. The histological sections obtained from sacrificed rabbits, when viewed under the light microscope, clearly showed the presence of PDL around dental implants. CBCT examination showed that the implant was well within the bone and did not migrate. The site appeared to be normal without any lytic changes in the bone. Conclusion: It can safely be postulated from the present study that tissue engineering of PDL can be achieved around dental implants using PDLSCs. Important inter-tissue interactions like the formation of a functional PDL around the implantation site, and induction of bone formation in the vicinity of the implants may be possible. Future research in humans is required for further research.

Characterization of protease from Alcaligens faecalis and its antibacterial activity on fish pathogens.

Alcaligens faecalis AU01 isolated from seafood industry effluent produced an alkaline protease. The optimum culture conditions for growth as well as enzyme production were 37 degrees C and pH 8. The partially purified protease had specific activity of 9.66 with 17.77% recovery with the molecular weight of 33 kDa and it was active between 30-70 degrees C and optimum being at 55 degrees C and pH 9. The enzyme retains more than 85% activity at 70 degrees C and 78% even at pH 10. The enzyme inhibited the growth of fish pathogens such as Flavobacterium sp., Pseudomonas fluorescens, Vibrio harveyi, Proteus sp. and Vibrio parahaemolyticus. From the present study it can be concluded that Alcaligens faecalis AU01 has the potential for aquaculture as probiotic agent and other several applications.

In vitro anti-tumour studies on Cnicus wallichi DC.

Cnicus wallichi DC belonging to the family Asteraceae (Compositae) commonly known as Indian thistle and cirsium wallichi. It is an important medicinal plant indigenous to Nilgiris, Tamilnadu, South India. Since the related species Cnicus benedictus was reported for its anti cancer activities, In vitro screening studies for antitumour activities were carried out for different extracts of Cnicus wallichi DC. Seven different extracts were obtained from the aerial parts of the whole plant by successive solvent extraction and maceration process and subjected for In vitro screening studies. Antitumour study was carried out by short term toxicity studies using Dalton's Lymphoma Ascites (DLA) cells. The ethyl acetate extract of Cnicus wallichi DC showed significant antioxidant activity in all the methods.

In vitro antioxidant activities of Asteraceae Plants.

Anaphalis neelgerriana DC and Cnicus wallichi DC belonging to the family Asteraceae (Compositae) are important medicinal plants indigenous to Nilgiris. Since the related species Anaphalis morrisonicola and Cnicus benedictus were reported for its anti cancer activities, the above mentioned plants were screened for Invitro antioxidant activity. In vitro antioxidant studies were carried out by DPPH, Nitric oxide and Hydrogen peroxide methods for the aerial part extracts of the plants. Different extracts were obtained from the aerial parts of the whole plant by successive solvent extraction and cold maceration process and subjected for Invitro antioxidant activity studies. Among the extracts tested, the ethyl acetate extract of Anaphalis neelgerriana DC and Cnicus wallchi DC showed significant anti oxidant activity in all the above methods. The potent ethyl acetate extract should be tested for anti oxidant activity in animal models.

NUVIEW: software for display and interactive manipulation of nucleic acid models.

The NUVIEW software package allows skeletal models of any double helical nucleic acid molecule to be displayed on a graphics monitor and to apply various rotations, translations and scaling transformations interactively, through the keyboard. The skeletal model is generated by connecting any pair of representative points, one from each of the bases in the basepair. In addition to the above mentioned manipulations, the base residues can be identified by using a locator and the distance between any pair of residues can be obtained. A sequence based color coded display allows easy identification of sequence repeats, such as runs of Adenines. The real time interactive manipulation of such skeletal models for large DNA/RNA double helices, can be used to trace the path of the nucleic acid chain in three dimensions and hence get a better idea of its topology, location of linear or curved regions, distances between far off regions in the sequence etc. A physical picture of these features will assist in understanding the relationship between base sequence, structure and biological function in nucleic acids.