Retromolar foramen and canal: a comprehensive review on its anatomy and clinical applications.

The retromolar foramen (RMF) and retromolar canal (RMC) are the anatomical structures of the mandible located in retromolar fossa behind the third molar tooth. This foramen and canal contain neurovascular structures which provide accessory/additional innervation to the mandibular molars and the buccal area. These neurovascular contents of the canal gain more importance in medical and dental practice, because these elements are vulnerable to damage during placement of osteointegrated implants, endodontic treatment and sagittal split osteotomy surgeries and a detailed knowledge of this anatomical variation would be vital in understanding failed inferior alveolar nerve blockage, spread of infection and also metastasis. Although few studies have been conducted in the past showing the incidence and types in different population groups, a lacunae in comprehensive review of this structure is lacking. Though this variation posed challenging situations for the practicing surgeons, it has been quite neglected and the incidence of it is not well presented in all the textbooks. Hence, we made an attempt to provide a consolidated review regarding variations and clinical applications of the RMF and RMC.

Comparison of immuno-phenotypes of stem cells from human dental pulp and periodontal ligament.

It has been established that human dental pulp and periodontal ligament contain a population of mesenchymal stem cells (MSCs). However, the phenotypic analysis in terms of putative stem cell markers expressed by these stem cell populations is incomplete. It is relevant to understand whether stem cells derived from closely related tissues are programmed differently. The aim of the present study is to analyze whether these stem cells depict distinct characteristics by gaining insight into differences in their immunophenotype. Dental pulp and periodontal ligament tissue samples were obtained from extracted impacted wisdom teeth. Cell cultures were analyzed for surface and intracellular markers by indirect immunoflourescence. Detailed immunophenotype analysis was carried out by flow cytometry using relevant markers. The present study data shows dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) expressed embryonic stem (ES) cell markers Oct-4, Nanog and mesodermal marker Vimentin by indirect immunoflourescence. PDLSCs, however, had a weak expression of Nanog. Immunophenotyping revealed strong expression of MSC markers (CD73, CD90) in DPSCs and PDLSCs. Differences were observed in expression of stemness-related markers. DPSCs displayed increased percentages of SSEA4, CD13 and CD166 and decreased CD9 expression compared to PDLSCs. Both stem cells express common MSC markers, different levels of expression suggests there might be more than one stem cell population existing within these tissues which differ in their embryonic status, and DPSCs are a more primitive stem cell population in comparison to PDLSCs.

Ovarian development in Wistar rat treated prenatally with single dose diisobutyl phthalate.

Phthalates are a class of industrial compounds with an array of toxicological properties used in day to day life. Diisobutyl phthalate on (DIBP) is used as an additive to keep the plastics soft or flexible (plasticizer) in nitrocellulose plastic, nail polish, explosives, lacquer manufacturing etc. Although DIBP exposure in humans is generally low, people in adhesive industries and pharmaceutical industries are exposed to higher levels. The aim of this study was to determine the effect of single dose of DIBP on developing ovary of Wistar rat. One hundred and eight adult pregnant Wistar rats were divided into control and experimental groups. Rats in experimental group were given DIBP on day 10, 12 and 14 of gestation at 0.375, 0.75 and 1.25 ml/kg body weight dose intraperitoneally in a single dose. Sections of ovaries collected on day 21 of gestation were stained with hematoxylin and eosin and examined and Masson's trichrome histologically. Sections belonging to the control group showed the presence of oocytes in clusters separated by thin fibrous septa. Degeneration oocytes, empty follicles surrounded by follicular cells without gonocytes in the center were observed in ovarian stroma. Blood vessels in the ovarian stroma were prominent and congested. Around a bunch of follicles total architectural disarray was observed although on special staining fibrosis was not evident. As pregnant women are constantly exposed, effect of DIBP on ovary of a developing fetus would denote the long term consequence in future generations (Fig. 5, Ref. 39).

A preliminary survey of the median artery in human cadavers of South Indian origin.

BACKGROUND: The median artery is a transitory vessel that represents the arterial axis of the forearm during early embryonic life. It normally regresses in the second embryonic month. Its persistence in the human adult has been recorded in 2 different patterns: as a large, long vessel (palmar type) which reaches the hand; or as a small and short vessel (antebrachial type) which ends before reaching the wrist joint. The palmar type is of major clinical significance. OBJECTIVE: This study was undertaken to investigate the incidence and course of the palmar type of the median artery in South Indian cadavers. MATERIAL AND METHODS: 25 upper limbs of South Indian cadavers were taken to study the median artery. RESULTS: The occurrence of median artery was 8%; of which 4% was on the right side and the other 4% was on the left side. On both sides, the artery originated from the ulnar artery. On the right side, the artery was involved in the formation of superficial palmar arch, whereas the artery on the left side did not join the arch; it terminated as 1st and 2nd common palmar digital arteries. CONCLUSION: Persistent median artery is closely related to the anterior interosseous nerve, it is possible that the artery may compress the anterior interosseous nerve and cause the anterior interosseous nerve syndrome (Fig. 2, Ref. 17).

Chondrohumeralis and axillary arch of Langer: a rare combination of variant muscles with unique insertion.

During routine dissection, we found a rare case of an aberrant muscular slip originating from the pectoralis major called as the "chondroepitrochlearis / thoracoepicondylaris / costohumeralis" and an anomalous slip from the latissimus dorsi called as "axillary arch of Langer / musculus dorsoepitrochlearis" in the same axilla. Interestingly, these two slips found to have a common insertion after arching superficial to the axillary neurovascular bundle, into the fascia covering the biceps brachi and to the lateral lip of the intertubercular sulcus of the humerus. Presence of combination of these two rare variant muscles and their unique insertion pattern has not been reported earlier. The knowledge of these muscle variations is important for the clinicians and physiotherapist for better diagnosis and treatment. Here in this report, in addition to the case presentation, we also discuss their clinical significance and the review of literature in detail.

Mechanisms Underlying Graft Union Formation and Rootstock Scion Interaction in Horticultural Plants.

Grafting is a common practice for vegetative propagation and trait improvement in horticultural plants. A general prerequisite for successful grafting and long term survival of grafted plants is taxonomic proximity between the root stock and scion. For the success of a grafting operation, rootstock and scion should essentially be closely related. Interaction between the rootstock and scion involves complex physiological-biochemical and molecular mechanisms. Successful graft union formation involves a series of steps viz., lining up of vascular cambium, generation of a wound healing response, callus bridge formation, followed by vascular cambium formation and subsequent formation of the secondary xylem and phloem. For grafted trees compatibility between the rootstock/scion is the most essential factor for their better performance and longevity. Graft incompatibility occurs on account of a number of factors including of unfavorable physiological responses across the graft union, transmission of virus or phytoplasma and anatomical deformities of vascular tissue at the graft junction. In order to avoid the incompatibility problems, it is important to predict the same at an early stage. Phytohormones, especially auxins regulate key events in graft union formation between the rootstock and scion, while others function to facilitate the signaling pathways. Transport of macro as well as micro molecules across long distances results in phenotypic variation shown by grafted plants, therefore grafting can be used to determine the pattern and rate of recurrence of this transport. A better understanding of rootstock scion interactions, endogenous growth substances, soil or climatic factors needs to be studied, which would facilitate efficient selection and use of rootstocks in the future. Protein, hormones, mRNA and small RNA transport across the junction is currently emerging as an important mechanism which controls the stock/scion communication and simultaneously may play a crucial role in understanding the physiology of grafting more precisely. This review provides an understanding of the physiological, biochemical and molecular basis underlying grafting with special reference to horticultural plants.

Unusual communication between the lingual nerve and mylohyoid nerves in a South Indian male cadaver: its clinical significance.

It is well known that variations in the branching pattern of the mandibular nerve frequently account for the failure to obtain adequate local anesthesia in routine oral and dental procedures, and also for the unexpected injury to branches of the nerves during surgery. During our routine dissection, we found the presence of a communicating branch between the mylohyoid and lingual nerves in a middle aged male cadaver. We also discussed its clinical and surgical implications in this report.

A novel antioxidant 3-O-Caffeoyl-1-methylquinic acid enhances ultraviolet A-mediated apoptosis in immortalized HaCaT keratinocytes via Sp1-dependent transcriptional activation of p21(WAF1/Cip1).

It has become clear that ultraviolet A (UVA) radiation from the solar spectrum is a major environmental challenge to the skin. This necessitates developing novel mechanism-based agents capable of ameliorating UVA-induced effects in the skin. We recently described a novel antioxidant, 3-O-Caffeoyl-1-methylquinic acid (MCGA3) from leaves of bamboo. Here, we investigated the photochemopreventive effects of MCGA3 against UVA-mediated apoptosis in immortalized HaCaT keratinocytes. Pretreatment of MCGA3 rendered cells more sensitive to subsequent UVA irradiation-induced apoptosis as well as completely reversed UVA-induced sustained phosphorylation of extracellular signal-regulated kinase 1/2 and protein kinase Calpha, downregulation of p21, and reactive oxygen species generation. Interestingly, MCGA3 itself effectively induced p21 protein and mRNA levels. Silencing of p21 by RNA interference revealed a pivotal role of p21 in generating G(1)-S arrest and in enhancing UVA-mediated apoptosis. Transcriptional activation of p21 by MCGA3 was mediated through the proximal region of multiple Sp1 sites regardless of p53-binding site in p21 promoter, and this effect was augmented by desferroioxamine, an iron chelating agent. Additional studies suggested that iron chelation-driven hypoxia by MCGA3 may function in activation of p21. MCGA3 could be a useful agent to prevent photocarcinogenesis via apoptotic elimination of p53 mutant and DNA-repair defective cells caused by UVA radiation.

High origin of ulnar artery in South Indian male cadaver: a case report.

Superficial ulnar artery, a rare variation may arise from axillary or brachial artery. Here we report a case of high origin of superficial ulnar artery from the axillary artery. Superficial ulnar artery, after running under the bicipital aponeurosis in the cubital fossa, it terminated as superficial palmar arch in the hand. We also discuss its clinical and embryological relevance.

The miti-mere and pdm1 genes collaborate during specification of the RP2/sib lineage in Drosophila neurogenesis.

We have investigated (i) the role of pdm1, a Drosophila POU gene, during the elaboration of the GMC-1-->RP2/sib lineage and (ii) the functional relationship between pdm1 and the closely linked second POU gene, miti-mere, in this lineage. We show that deletion of pdm1 causes a partially penetrant GMC-1 defect, while deletion of both miti and pdm1 results in a fully penetrant defect. This GMC-1 defect in miti- and pdm1- embryos can be rescued by the pdm1 or miti transgene. Rescue is observed only when these genes are expressed at the time of GMC-1 formation. Overexpression of pdm1 or miti well after GMC-1 is formed results in the duplication of RP2 and/or sib cells. Our results indicate that both genes are required for the normal development of this lineage and that the two collaborate during the specification of GMC-1 identity.

Isolated gingival overgrowths: A review of case series.

Clinicians are often intrigued by the varied manifestations of the gingival tissue. Gingival overgrowth is a common clinical finding and most of them represent a reactive hyperplasia as a direct result of plaque-related inflammatory gingival disease. These types of growth generally respond to good plaque control, removal of the causative irritants, and conservative tissue management. This case series highlights three different cases of localized gingival overgrowth and its management with emphasis on the importance of patient awareness and motivation.

The activity of porcine pancreatic phospholipase A2 in 20% alcohol/aqueous solvent, by experiment and electrostatics calculations.

The activity of porcine pancreatic phospholipase A2 (pla2), measured at pH 8, is reduced when methanol or ethanol is added to the aqueous solution. Finite difference electrostatics calculations were used to study the effect of modelling mixed solvents on the pKas of histidine 48 and the amino-terminal group, both of which influence the pH-dependence of catalysis. Calculations and experiment indicate that these pKa values cannot account for the activity reduction. Charge separation in the transition state is destabilized in 20% alcohol solvent relative to 100% aqueous solvent. The calculated values, which are combinations of stabilizing and destabilizing contributions, are in qualitative agreement with experiment. Saturating dielectric theory is used to model solvent water ordering in a high electric field, and water dielectric structure is assumed to dominate at the 20% alcohol level. The observed agreement demonstrates the utility of transition state stabilization theory and continuum solvent modelling. It is further suggested that electrostatic effects on kcat contribute to the pH-dependence of activity around pH 7, and to previously reported activity changes for charge mutants.

The posterior determinant gene nanos is required for the maintenance of the adult germline stem cells during Drosophila oogenesis.

In a variety of tissues in eukaryotes, multipotential stem cells are responsible for maintaining a germinal population and generating a differentiated progeny. The Drosophila germline is one such tissue where a continuous supply of eggs or sperm relies on the normal functioning of stem cells. Recent studies have implicated a possible role for the posterior determinant gene nanos (nos) in stem cells. Here, I report that nanos is required in the Drosophila female germline as well as in the male germline. In the female, nos is required for the functioning of stem cells. In nos mutants, while the stem cells are specified, these cells divide only a few times at the most and then degenerate. The loss of germline stem cells in nos mutant mothers appears to be due to a progressive degeneration of the plasma membrane. Furthermore, following germ cell loss, the germaria in the nos mutant mothers appear to carry on massive mitochondrial biogenesis activity. Thus, the syncytia of such germaria are filled with mitochondria. In the male germline, the male fertility assay indicates that nos appears to be also required for the maintenance of stem cells. In these mutant males, spermatogenesis is progressively affected and these males eventually become sterile. These results indicate novel requirements for nos in the Drosophila germline.

Cell-cell signaling during neurogenesis: some answers and many questions.

Development of a multicellular organism requires that cells communicate with each other in order to regulate their growth, organize into tissues and coordinate their function. This cell-cell communication is mediated by signals cells receive (or send) between each other and from the environment. The signaling can be a short range remote signaling (through secreted signaling molecules), contact signaling (via plasma membrane bound molecules, gap junctions) or a long range signaling (through hormones). In this article, I have reviewed the recent advances on the role of cell-cell signaling in the development of the embryonic nervous system of the fruitfly Drosophila melanogaster and discussed some of the open questions raised by these studies. It discusses the contributions of the neurogenic genes Notch and Delta and the signaling pathways controlled by wingless, patched and hedgehog in neuroblast formation, neuroblast identity specification and neuroblast lineage elaboration.

Efficacy of Human Chorion Membrane Allograft for Recession Coverage: A Case Series.

BACKGROUND: Membranes of human placentas have been used in the field of medicine for skin grafts, treatment of burns, and ulcerated skin conditions with great success. The use of placenta allografts in dentistry is a more recent development, with the first commercial product being made available in 2008. The unique inherent biologic properties in placenta allografts enhance wound healing and may propagate regeneration. METHODS: Ten healthy adult patients presenting with 21 Miller Class I gingival recession (GR) defects (isolated or adjacent multiple) were surgically treated with a modified coronally advanced flap and chorion membrane for root coverage. Clinical parameters measured at baseline, 3 months, and 6 months were probing depth, clinical attachment level, GR height, width of keratinized gingiva, and assessment of gingival biotype. Statistical analysis was performed to compare the treatment outcomes at the follow-up intervals. RESULTS: The results showed statistically significant (P <0.001) improvements in all clinical parameters at the 3- and 6-month follow-ups. The mean percentage of root coverage at the end of 6 months was 89.92% ± 15.59%, and 14 of 21 treated GR defects showed 100% root coverage. The gingival biotype also showed a thick biotype in nine sites that had an initial thin biotype. CONCLUSIONS: Fetal membranes possess distinctive properties that can be harnessed to promote periodontal healing. The chorion membrane covered by a modified coronally advanced flap is a new approach that has shown promising results in terms of root coverage, increased width of keratinized tissue, and thickness of the gingival biotype.

Modification of the stability of phospholipase A2 by charge engineering.

Electrostatic interactions play an important role in stabilizing the folded conformation of globular proteins. Here we predict the change in stability of charge engineered mutants, construct these mutants and compare the predicted change in stability with that observed. The change in stability was correctly predicted for two of the three mutants and the factors responsible for the discrepancy between observation and prediction for the third mutant are discussed.

Clinical significance of furcation anatomy of the maxillary first premolar: a biometric study on extracted teeth.

Multirooted teeth in which chronic periodontitis has progressed to involve the furcation present special problems in treatment. The apical placement of furcation, narrow furcation entrance, concavities on the root surface, and the undesirable root configuration make instrumentation and plaque control difficult. Furcation involvement, when present in maxillary first premolars in particular, presents a poor prognosis as the furcation opens mesiodistally. This study on 100 extracted maxillary first premolars is an attempt to determine the frequency of bifurcation, the proximity of bifurcation to cemento-enamel junction, the depth of concavities on the root trunk and the furcal aspect of root, the diameter of furcation entrance, and the extent of root divergence.

LC determination and pharmacokinetics of meloxicam.

A simple and rapid HPLC assay method for the estimation of meloxicam in plasma was developed. The method totally eliminated the solvent extraction procedure. The plasma proteins were precipitated using perchloric acid (70%) and acetonitrile mixture (1:1 v/v) and the supernatant was directly injected to the HPLC system. The separation was achieved on a Lichrospher C18 5 micron (125x4.0 mm) analytical column with a mobile phase of sodium acetate buffer (pH 3.3, 170 mmol):acetonitrile (62:38 v/v) mixture. Detection was by UV detector at 355 nm. The retention time observed for meloxicam and piroxicam (internal standard) were at 6.0 and 4.0 min, respectively. The response was linear over a range of 50-1500 ng x ml(-1) in human plasma. The method was simple, specific, precise and accurate. The method was also used for the bioequivalence study of meloxicam formulation in healthy, human, Indian, male volunteers.

Local antimicrobial delivery in periodontal therapy.

Treatment strategies towards periodontal diseases have evolved to eliminate specific pathogens or suppress destructive host response. The inherent activity of the antibiotic against the target microorganism and various Pharmacokinetic parameters such as potency, permeability, intrinsic efficacy, and substantivity of the drug dictate the success of the therapeutic outcome. However selection of an appropriate delivery system is an important factor. Rapid advances in molecular biology have helped to overcome the disadvantages of systemic and topical applications, by direct placement of antimicrobial agent (s) into subgingival sites, thus minimizing antimicrobial impact on non-oral body sites. As periodontitis is a 'localized' disease condition it is amenable to localized drug treatments. By means of controlled local delivery from within the periodontal pocket, a single administration of a few milligram of an antibacterial agent can maintain therapeutic concentrations within the crevicular fluid for a longer period of time than any other mode of delivery. This paper shall review the different local delivery systems along with the commonly employed drugs through these delivery systems.

Evaluation of efficacy of Sofscale. A clinical and SEM study.

Efficacy of Sofscale in the case of removal of calculus from the root surface as claimed by manufacturers was evaluated in the present study. 32 patients suffering from chronic periodontitis, having calculus deposits in the lower incisors were selected for the study. A double blind study was conducted to evaluate the ease with which calculus could be removed. In the second part of study, a SEM study of the root surface subjected to root planing alone and root planing after application of Sofscale was done to see whether any remnants of calculus was left behind. In the double blind study conducted on 32 patients, it was found in 21 patients, calculus could be removed with greater ease and less time in experimental area compared to the control. 17 patients were able to correctly identify the product side as easier to Sofscale. Patients did not complain of increased sensitivity of teeth or discomfort following application of Sofscale. Under SEM the root surface after root planing showed the presence of smear layer whereas after Sofscale application root surface appeared devoid of smear layer. No other significant difference were noticed between the root surfaces.