Fungal-Bacterial Combinations in Plant Health under Stress: Physiological and Biochemical Characteristics of the Filamentous Fungus Serendipita indica and the Actinobacterium Zhihengliuella sp. ISTPL4 under In Vitro Arsenic Stress

Fungal-bacterial combinations have a significant role in increasing and improving plant health under various stress conditions. Metabolites secreted by fungi and bacteria play an important role in this process. Our study emphasizes the significance of secondary metabolites secreted by the fungus Serendipita indica alone and by an actinobacterium Zhihengliuella sp. ISTPL4 under normal growth conditions and arsenic (As) stress condition. Here, we evaluated the arsenic tolerance ability of S. indica alone and in combination with Z. sp. ISTPL4 under in vitro conditions. The growth of S. indica and Z. sp. ISTPL4 was measured in varying concentrations of arsenic and the effect of arsenic on spore size and morphology of S. indica was determined using confocal microscopy and scanning electron microscopy. The metabolomics study indicated that S. indica alone in normal growth conditions and under As stress released pentadecanoic acid, glycerol tricaprylate, L-proline and cyclo(L-prolyl-L-valine). Similarly, d-Ribose, 2-deoxy-bis(thioheptyl)-dithioacetal were secreted by a combination of S. indica and Z. sp. ISTPL4. Confocal studies revealed that spore size of S. indica decreased by 18% at 1.9 mM and by 15% when in combination with Z. sp. ISTPL4 at a 2.4 mM concentration of As. Arsenic above this concentration resulted in spore degeneration and hyphae fragmentation. Scanning electron microscopy (SEM) results indicated an increased spore size of S. indica in the presence of Z. sp. ISTPL4 (18 ± 0.75 µm) compared to S. indica alone (14 ± 0.24 µm) under normal growth conditions. Our study concluded that the suggested combination of microbial consortium can be used to increase sustainable agriculture by combating biotic as well as abiotic stress. This is because the metabolites released by the microbial combination display antifungal and antibacterial properties. The metabolites, besides evading stress, also confer other survival strategies. Therefore, the choice of consortia and combination partners is important and can help in developing strategies for coping with As stress.

Understanding megasporogenesis through model plants: contemporary evidence and future insights

The megasporangium serves as a model system for understanding the concept of individual cell identity, and cell-to-cell communication in angiosperms. As development of the ovule progresses, three distinct layers, the epidermal (L1), the subepidermal or the hypodermal (L2) and the innermost layers (L3) are formed along the MMC (megaspore mother cell). The MMC, which is the primary female germline cell, is initiated as a single subepidermal cell amongst several somatic cells. MMC development is governed by various regulatory pathways involving intercellular signaling, small RNAs and DNA methylation. The programming and reprograming of a single nucellar cell to enter meiosis is governed by 'permissive' interacting processes and factors. Concomitantly, several nucellar sister cells are prevented from germline fate also by a set of 'repressive' factors. However, in certain angiosperms, anomalies in development of the female gametophyte have been observed. The sporophytic tissue surrounding the female gametophyte affects the gametophyte in multiple ways. The role of genes and transcription factors in the development of the MMC and in the regulation of various processes studied in selected model plants such as Arabidopsis is explained in detail in this paper. However, as angiosperms display enormous diversity, it is important to investigate early stages of megasporogenesis in other plant systems as well. Such studies provide valuable insights in understanding the regulation of megasporogenesis and the evolution of the female gametophyte from gymnosperms to flowering plants.

A Comparative Evaluation of Pain Experience and Time of Onset of 2% Lignocaine and 4% Articaine in Inferior Alveolar Nerve Block among Pediatric Population: A Clinical Study

Aim

The objective of this research was to conduct a comparison and evaluate the pain perception and time of onset of 2% lignocaine 1:80,000 epinephrine with 4% articaine 1:100,000 epinephrine in the pediatric population.

Materials and methods

A split-mouth randomized control trial was conducted on 50 children aged 9-14 years who required inferior alveolar nerve block (IANB) anesthesia for bilateral dental treatment in the mandibular arch. The time of onset was recorded when no sensation was reported even when maximum electrical stimulus was applied in an electric pulp testing (EPT). The pain perception was assessed using a visual analog scale (VAS) rated by the patient for subjective symptoms and face, legs, activity, cry, and consolability (FLACC) scale for objective pain rated by the operator.

Results

The mean onset of time, pain-VAS, and FLACC score decreased by 1.31, 12.07, and 18.39%, respectively in 4% articaine as compared to 2% lignocaine but the difference did not reach statistical significance (p > 0.05), that is, found to be statistically the same.In conclusion, it can be inferred that the utilization of 4% articaine is as potent as 2% lignocaine solution but showed slightly better onset of anesthesia and pain experience among the children although the findings were not statistically significant.

Clinical significance

Local anesthesia (LA) is one of the main methods of pain management in pediatric practice which makes it essential to choose an LA agent with a shorter time of onset and less pain on administration.

How to cite this article

Singh SS, Koul M. A Comparative Evaluation of Pain Experience and Time of Onset of 2% Lignocaine and 4% Articaine in Inferior Alveolar Nerve Block among Pediatric Population: A Clinical Study. Int J Clin Pediatr Dent 2024;17(1):67-71.

Powder plasma spheroidization treatment and the characterization of microstructure and mechanical properties of SS 316L powder and L-PBF builds

A plasma spheroidization treatment was applied to stock stainless steel 316L powder for additive manufacturing. The normal and treated powders were compared both in the powder state as well as in the resulting laser powder bed fusion (L-PBF) builds. The plasma spheroidization process slightly increased treated powder aspect ratio and sphericity and shifted the size distribution to larger diameters relative to the normal powder. The normal powder was austenitic in nature whereas the plasma spheroidization process introduced a small fraction (∼3.5 vol %) of ferrite in the treated powder. Ferrite in the powder was not retained in the printed samples and was not shown to negatively affect the build quality. Porosity areal fraction was generally smaller in the treated powder builds. The normal powder builds had a 6% higher yield strength than treated, however the scatter was significantly larger in the 45° and horizontal orientations compared to the treated powder builds.

Interaction studies of Serendipita indica and Zhihengliuella sp. ISTPL4 and their synergistic role in growth promotion in rice

Rapid urbanization and globalization demand increasing agricultural productivity. Soil nutrient supply capacity is continuously decreasing due to soil erosion, degradation, salt deposition, undesired element, metal deposition, water scarcity, and an uneven nutrient delivery system. Rice cultivation requires a large amount of water which is becoming detrimental due to these activities. There is a need to increase its productivity. Microbial inoculants are becoming increasingly important in achieving sustainable agricultural production systems. The current study was conducted to investigate the interaction between the root endophytic fungus Serendipita indica (S. indica) and the actinobacterium Zhihengliuella sp. ISTPL4 (Z. sp. ISTPL4) and their synergistic effects on the growth of rice (Oryza sativa L). Both S. indica and Z. sp. ISTPL4 showed positive interactions. Growth of S. indica was observed at different days after Z. sp. ISTPL4 inoculation, and stimulated growth of S. indica was observed when Z. sp. ISTPL4 was inoculated at 5 dafi (days after fungal inoculation). Z. sp. ISTPL4 promoted the growth of S. indica as it increased spore germination. Furthermore, confocal and scanning electron microscopy (SEM) analyses showed a 27% increase in the spore size of S. indica in the presence of Z. sp. ISTPL4. In a liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis increased production of alanine and glutamic acid was observed in their sequential co-culture as compared with individual cultures. Sequential inoculation of S. indica and Z. sp. ISTPL4 significantly increased the biochemical and physical characteristics of rice as compared with their individual inoculum. Biochemical parameters such as chlorophyll content, total soluble sugar, and flavonoid content in the rice increased by up to 57%, 47%, and 39%, respectively, in the presence of the combined inoculum of S. indica and Z. sp. ISTPL4. This will be the first study, to the best of our knowledge, which shows the fungus and actinobacterium interaction and their synergistic roles in the growth promotion of rice. Furthermore, this novel combination can also be used to boost the growth of other crops to increase the agricultural yield.

Comparative Evaluation of Antimicrobial Efficacy of Diode Laser (Continuous Mode), Diode Laser (Pulse Mode), and 5.25% of Sodium Hypochlorite in Disinfection of Root Canal: A Short Study

Introduction

The success of endodontic treatment is achieved by the complete elimination of pulpal infection and protection from future invasion of microorganisms. Due to the complex structure of the root canal, complete eradication of microorganisms is not possible and is a major challenge for successful endodontic treatment. Therefore, microbiological studies are needed to explore the effect of various disinfection methods.

Aim and objective

The aim of this study is to compare the effectiveness of root canal disinfection by using a diode laser (in pulse and continuous modes) and sodium hypochlorite by microbiological assessment.

Materials and methods

Forty-five patients were selected and randomly divided into three groups. After gaining patency to the root canal the first sample from the root canal was taken using a sterile absorbent paper point and transferred to a sterile tube containing a normal saline medium. Biomechanical preparation was performed with Dentsply Protaper hand files of each corresponding group and was disinfected with group I (diode light amplification by stimulated emission of radiation (LASER) 980 nm with 3 W in continuous mode for 20 seconds), group II (diode LASER 980 nm with 3 W in pulse mode for 20 seconds), group III (irrigated with 5.25% of sodium hypochlorite for 5 minutes). Pre- and post-samples of each group were inoculated on sheep blood agar and examined for any bacterial growth. After the microbial evaluation of the total microbial count of pre- and post-samples, the data obtained were tabulated and statistically analyzed.

Results

The data were evaluated and analyzed using analysis of variance (ANOVA) on Statistical Package for the Social Sciences (SPSS) software. Groups I, II, and III all three groups showed significant differences (p < 0.01) and an overall reduction in the microbial count at postbiomechanical preparation (BMP) as compared to pre-BMP with the highest being in laser in continuous mode (group I) (91.9%), followed by 5.25% sodium hypochlorite (group III) (86.5%) and LASER in pulse mode (group II) (72.0%) the least.

Conclusion

The study concluded that the diode laser in continuous mode is more efficacious than the diode laser in pulse mode and 5.2% sodium hypochlorite, respectively.

How to cite this article

Mishra A, Koul M, Abdullah A, et al. Comparative Evaluation of Antimicrobial Efficacy of Diode Laser (Continuous Mode), Diode Laser (Pulse Mode), and 5.25% of Sodium Hypochlorite in Disinfection of Root Canal: A Short Study. Int J Clin Pediatr Dent 2022;15(5):579-583.

Leaf Functional Traits of Invasive Grasses Conferring High-Cadmium Adaptation Over Natives

Heavy metal (HM) contamination resulting from industrialization and urbanization during the Anthropocene along with plant invasion can severely threaten the growth and adaptation of local flora. Invasive alien plant species generally exhibit a growth pattern consistent with their functional traits in non-contaminated environments in the introduced range. However, it remains unclear whether invasive alien plants have an advantage over native plants in contaminated environments and whether this growth pattern is dependent on the adaptation of their leaf functional traits. Here, we selected two congeneric pairs of invasive alien and native grasses that naturally co-exist in China and are commonly found growing in contaminated soil. To evaluate the effect of cadmium (Cd) on the structural and physiological leaf traits, we grew all four species in soil contaminated without or with 80 mg/kg Cd. Invasive plants contained significantly higher concentrations of Cd in all three organs (leaf, stem, and root). They displayed a higher transfer factor and bioconcentration factor (BCF) of shoot and root than natives, indicating that invasive species are potential Cd hyperaccumulators. Invasive plants accumulated polyphenol oxidase (PPO) to higher levels than natives and showed similar patterns of leaf structural and physiological traits in response to changes in Cd bioconcentration. The quantifiable leaf structural traits of invasive plants were significantly greater (except for stomatal density and number of dead leaves) than native plants. Leaf physiological traits, chlorophyll content, and flavonoid content were also significantly higher in invasive plants than in natives under Cd stress conditions after 4 weeks, although nitrogen balance index (NBI) showed no significant difference between the two species. Chlorophyll fluorescence parameters decreased, except for the quantum yield of photosystem II (ΦPSII) and the proportion of open photosystem II (qP), which increased under Cd stress conditions in both species. However, invasive plants exhibited higher fluorescence parameters than natives under Cd stress, and the decrement observed in invasive plants under Cd stress was greater than that in natives. High Cd adaptation of invasive grasses over natives suggests that invasive plants possess optimal leaf structural and physiological traits, which enable them to adapt to stressful conditions and capture resources more quickly than natives. This study further emphasizes the potential invasion of alien plants in contaminated soil environments within the introduced range. To a certain extent, some non-invasive alien plants might adapt to metalliferous environments and serve as hyperaccumulator candidates in phytoremediation projects in contaminated environments.

Heat Stress-Mediated Constraints in Maize (Zea mays) Production: Challenges and Solutions

An increase in temperature and extreme heat stress is responsible for the global reduction in maize yield. Heat stress affects the integrity of the plasma membrane functioning of mitochondria and chloroplast, which further results in the over-accumulation of reactive oxygen species. The activation of a signal cascade subsequently induces the transcription of heat shock proteins. The denaturation and accumulation of misfolded or unfolded proteins generate cell toxicity, leading to death. Therefore, developing maize cultivars with significant heat tolerance is urgently required. Despite the explored molecular mechanism underlying heat stress response in some plant species, the precise genetic engineering of maize is required to develop high heat-tolerant varieties. Several agronomic management practices, such as soil and nutrient management, plantation rate, timing, crop rotation, and irrigation, are beneficial along with the advanced molecular strategies to counter the elevated heat stress experienced by maize. This review summarizes heat stress sensing, induction of signaling cascade, symptoms, heat stress-related genes, the molecular feature of maize response, and approaches used in developing heat-tolerant maize varieties.

Interaction between Cymbidium aloifolium and Apis cerana: Incidence of an outlier in modular pollination network of oil flowers

So far, oil‐rewarding flowers are known to be pollinated only by oil‐collecting bees, which gather and use lipids for larval feed and nest building. As honeybees do not have oil‐collecting appendages on their legs, they have not been associated with pollination of such flowers. In a predominantly Apis pollinated and food deceptive clade of wild Cymbidiums, we investigated the reproductive strategy of Cymbidium aloifolium, hitherto unknown for its floral oil reward. Our study demonstrates the requisites for establishment of mutualistic interaction between the oil flower and Apis cerana indica, a corbiculate bee. Success in pollination requires learning by honeybees to access the food reward, thereby displaying cognitive ability of the pollinator to access the customized reward. Morphometric matching between orchid flowers and the pollinator, and that between pollinia and stigmatic cavity also appear to be essential in the pollination success. Absence of pollinator competition and prolonged flower‐handling time are suggested to promote floral constancy. The present study highlights the need to explore the spectrum of pollination rewards pursued by honeybees, which may include unconventional composition of floral resources.

Breeding System and Response of the Pollinator to Floral Larceny and Florivory Define the Reproductive Success in Aerides odorata

Consumption of pollination reward by felonious means in a plant species can influence the foraging behavior of its pollinator and eventually the reproductive success. So far, studies on this aspect are largely confined to interaction involving plant-pollinators and nectar robbers or thieves. However, a foraging guild in such interactions may also include floral herbivores or florivores. There is a paucity of information on the extent to which nectar larcenists may influence the foraging behavior of the pollinator and reproductive fitness of plants in the presence of a florivore. We investigated various forms of larceny in the natural populations of Aerides odorata, a pollinator-dependent and nectar-rewarding orchid. These populations differed in types of foraging guild, the extent of larceny (thieving/robbing), which can occur with or without florivory, and natural fruit-set pattern. The nectariferous spur of the flower serves as an organ of interest among the foraging insects. While florivory marked by excision of nectary dissuades the pollinator, nectar thieving and robbing significantly enhance visits of the pollinator and fruit-set. Experimental pollinations showed that the species is a preferential outbreeder and experiences inbreeding depression from selfing. Reproductive fitness of the orchid species varies significantly with the extent of floral larceny. Although nectar thieving or robbing is beneficial in this self-compatible species, the negative effects of florivory were stronger. Our findings suggest that net reproductive fitness in the affected plant species is determined by the overarching effect of its breeding system on the overall interacting framework of the foraging guild.

Exploring the sister cells of embryo sac: developmental and functional attributes

Synergids are metabolically dynamic cells of the egg apparatus and represent an important component of the female gametophyte. Besides directing the growth of the pollen tube towards the micropylar end of the embryo sac, these ephemeral structures make room for the pollen tube cytoplasm. The nature of chemotrophic substances that direct the growth of the pollen tube, the mechanism of degeneration of one of the synergids before fertilization and the molecular aspects of synergid morphogenesis have been studied in detail. Research carried out on model systems such as Arabidopsis, Brassica, Capsella, Triticum and Torenia has expanded our understanding of the molecular regulation of the pollen tube journey, its guidance and navigation in the pistil. Recently, the critical role of the central cell in fertilization and prevention of polytubey has also been thoroughly investigated. Interesting aspects that lead to degeneration of synergids, and the factors governing degeneration, including molecular aspects, have produced a paradigm shift in the understanding of these intriguing units. Sophisticated confocal microscopy, live cell imaging, and molecular tools have helped in furthering our knowledge of the functioning of synergids. Recent research using high throughput techniques has deciphered the role of various genes that regulate and govern the release of chemotropic substances, cell-to-cell interaction and synergid cell degeneration. Moreover, with the diversity displayed in form and function of organs in the angiosperms, and the switching of roles of the cells of egg apparatus, new insights have been provided into the involvement of synergids both pre- and post-fertilization. The present review provides a comprehensive account of synergids, their role in fertilization and the post fertilization events that have emerged using interdisciplinary approaches in recent years. We also discuss the variations observed in degeneration of synergids and the mechanisms that have been unraveled recently. Study of the dynamism exhibited by synergids reveals newer roles of these in fertilization. How synergids in angiosperm taxa where genetic transformation/alteration is carried out will respond to pollen stimuli is still unknown. Since environmental factors such as light and temperature have a significant impact on synergids and fertilization, it would be rewarding to study the role of chemo-attractants and other factors in elucidating the functional roles of synergids. Further research into developing adequate protocols for manipulating synergid functions is certainly required. This research has enormous potential in the advancement of basic science and has potential applications in agriculture, horticulture, and bioprospecting.

To Evaluate and Compare the Clinical and Radiographic Outcomes of Formocresol, Mineral Trioxide Aggregate, Electrocautery, and Bioactive Glass when used for Pulpotomy in Human Primary Teeth

AIMS

The aim of the present study is to evaluate and compare the clinical and radiographic outcomes of formocresol (FC), mineral trioxide aggregate (MTA), electrocautery, and bioactive glass (BAG) when used for pulpotomy in human primary teeth.

SETTINGS AND DESIGN

The present study comprised of total four Groups A, B, C, and D; the selected children for the procedure were randomly divided into four groups according to the type of agent used as Group A, Group B, Group C, and Group D, respectively, having 20 teeth.

METHODOLOGY

In this study, pulpotomies were performed on the respective teeth. The teeth were treated using either FC, MTA, electrocautery, and BAG. Following the pulpotomy procedure, the teeth were evaluated for the clinical and radiographic success for 3, 6, and 12 months. The teeth were evaluated for the presence of pain, swelling, internal and external resorption, and radiolucency.

STATISTICAL ANALYSIS USED

Fisher's exact test and Yates corrected Chi-square test is used.

RESULTS

After 12 months of follow-up, the clinical and radiographic success rates were high. Comparing the frequency (%) of overall clinical success rate of four groups at 12 months, the Chi-square test revealed significantly different and higher overall clinical success rate in MTA as compared to other groups, especially FC and EC at 12 months. Comparing the frequency (%) of overall radiographic success rate of four groups at 12 months, the Chi-square test revealed significantly different and higher overall radiographic success rate in MTA as compared to other groups, especially FC and EC at 12 months.

CONCLUSIONS

In this study, the success rates of MTA, BAG, and FC are matching their physical and chemical properties which have been detailed and explained earlier.

Infectious laryngotracheitis: Etiology, epidemiology, pathobiology, and advances in diagnosis and control - a comprehensive review

Infectious laryngotracheitis (ILT) is a highly contagious upper respiratory tract disease of chicken caused by a Gallid herpesvirus 1 (GaHV-1) belonging to the genus Iltovirus, and subfamily Alphaherpesvirinae within Herpesviridae family. The disease is characterized by conjunctivitis, sinusitis, oculo-nasal discharge, respiratory distress, bloody mucus, swollen orbital sinuses, high morbidity, considerable mortality and decreased egg production. It is well established in highly dense poultry producing areas of the world due to characteristic latency and carrier status of the virus. Co-infections with other respiratory pathogens and environmental factors adversely affect the respiratory system and prolong the course of the disease. Latently infected chickens are the primary source of ILT virus (ILTV) outbreaks irrespective of vaccination. Apart from conventional diagnostic methods including isolation and identification of ILTV, serological detection, advanced biotechnological tools such as PCR, quantitative real-time PCR, next generation sequencing, and others are being used in accurate diagnosis and epidemiological studies of ILTV. Vaccination is followed with the use of conventional vaccines including modified live attenuated ILTV vaccines, and advanced recombinant vector vaccines expressing different ILTV glycoproteins, but still these candidates frequently fail to reduce challenge virus shedding. Some herbal components have proved to be beneficial in reducing the severity of the clinical disease. The present review discusses ILT with respect to its current status, virus characteristics, epidemiology, transmission, pathobiology, and advances in diagnosis, vaccination and control strategies to counter this important disease of poultry.

Pathodynamics of Circulating Strains of Duck Enteritis Virus: A Step Forward to Understand Its Pathogenesis

Duck enteritis virus (DEV) causes an acute and contagious infection in duck. The present study was carried out to evaluate the pathogenicity and pathodynamics of DEV isolates from different natural outbreaks in the Assam Province of India. A total of six wild-type isolates of DEV were revived in ducklings to determine its biologic characterization. Postmortem examination of infected ducklings revealed DEV-specific gross lesions in different organs. The presence of DEV was confirmed by its genome amplification and the presence of viral antigens from collected tissue samples by indirect fluorescent antibody test. All the isolates revived in ducklings were further propagated in duck embryo fibroblast cells. Highly virulent and low virulent isolates of DEV were selected for further study based on median duck infectivity dose (DID₅₀) and median tissue culture infectivity dose (TCID₅₀). The highly virulent isolate of DEV had values of 10² DID₅₀/ml and 10^6.33 TCID₅₀/ml, whereas the low virulent strain had titers of 10 DID₅₀/ml and 10^4.83 TCID₅₀/ml in the cell culture. Our results showed replication of DEV in ducks with the highest and lowest viral titers in the thymus and bursa of Fabricius, respectively. In addition, microscopic analysis revealed necrosis and degeneration of submucosal esophageal glands and glandular epithelium. The study will be useful to understand the organ tropism and pathologic alteration among the virulent DEV isolates.

Twelve new additions in the orchid flora of Tripura, north-east India

Despite the discovery of several new plant species from India every year, there is dearth of information on species of orchid, especially from the North Eastern Region . As a detailed survey seemed necessary for reliable documentation, we looked into the diversity of orchids in Tripura state. We document the first records from the state for 12 species of orchids, including two genera (Crepidium Tausch and Dendrolirium Blume). Geographical distributions along with detailed descriptions and photographs of the species are provided.

New distribution records in the orchid flora of Tripura, India

Ten species of orchids belonging to eight genera are recorded for the first time from Tripura State of India.  The taxa include Bulbophyllum affine Wall. ex Lindl., Bulbophyllum lobbii Lindl., Coelogyne suaveolens (Lindl.) Hook.f., Dendrobium tortile Lindl., Micropera pallida Lindl., Mycaranthes floribunda (D.Don) S.C.Chen & J.J.Wood, Pinalia acervata (Lindl.) Kuntze, Pinalia globulifera (Seidenf.) A.N.Rao, Thelasis khasiana Hook.f. and Trichoglottis ramosa (Lindl.) Senghas.  Geographical distribution along with detailed descriptions and photographs of the recorded species are provided.

Incidence of elephant endotheliotropic herpesvirus in Asian elephants in India

Elephant endotheliotropic herpesviruses (EEHVs) are the cause of acute hemorrhagic disease in endangered Asian and African elephants. In the present study, we report the incidence of EEHV infection and associated mortality in the captive elephant of Assam, India. Our result showed the gross morphology and histopathological changes of EEHV infection in the elephant. Moreover, the phylogenetic analysis of the polymerase, helicase, and GPCR genes from the infected tissue samples suggested the presence of EEHV1A virus.

A rare case of three single rooted permanent second molars: A diagnosis with cone beam computed tomography (CBCT)

The aim of this article is to present a case with an unusual morphology of maxillary second molars on both sides and a mandibular second molar on right side in the same patient which was observed during routine endodontic procedure. Three second permanent molars had single root, single canal and an accurate assessment of this unusual morphology was made with the help of radiographs and cone beam computed tomography (CBCT). This report extends the range of known possible anatomical variations to include teeth with lesser number of roots and canals.

Comparative evaluation of antimicrobial substantivity of different concentrations of chlorhexidine as a root canal irrigant: An in vitro study

INTRODUCTION

The aim of this in vitro study was to evaluate and compare the antimicrobial substantivity of different concentrations of chlorohexidine as root canal irrigant by microbiological assay using mitis salivarius bacitracin streptomycin, MSBS agar plate.

METHODS

Extracted single rooted permanent human teeth were selected as samples and randomly divided into four groups (three experimental, one control). The samples of the three experimental groups used different concentration of chlorhexidine, CHX (0.1%, 1% and 2%), deionized water used as an irrigant served as control. In each group the apices of teeth were sealed with composite and mounted on plaster blocks. Root canals were prepared using step back technique and enlarged upto no 80. With each change in the file size the corresponding irrigant was used and final irrigation was done with deionized water. Samples were taken with paper points at 12 h, 1 day, 2 days and 3 days respectively and stored in sterile phials which were then arranged on MSBS agar plates for microbiological assay.

RESULTS AND CONCLUSION

Results were analysed by ANOVA and Tukey's HSD test showed that antibacterial substantivity of 2% CHX was best followed by 1% CHX and 0.1% CHX in decreasing order respectively.

Clinical evaluation of 3 Mix and Other Mix in non-instrumental endodontic treatment of necrosed primary teeth

PROBLEM CONSIDERED

The objective was to evaluate and compare the clinical and radiographic efficacy of two different combinations of antibacterial drugs when used in non-instrumental endodontic treatment of necrosed primary teeth.

MATERIALS AND METHOD

Forty teeth were randomly divided into two groups, viz. groups A and B having 20 teeth each. In Group A, 3 Mix (ciprofloxacin, metronidazole, and minocycline) and in Group B, Other Mix (ciprofloxacin, ornidazole, and minocycline) mixed with propylene glycol were used. Medication cavities of Group-A and B were filled with 3 Mix and Other Mix respectively followed by restoration of teeth. Clinical evaluation was done at 3 months whereas, clinical and radiographic evaluation was done at 6 and 12 months, respectively.

RESULTS

Both the groups showed 100% clinical success whereas, radiographic success rate was 81% with 3 Mix and 92% with Other Mix but, was not statistically significant.

CONCLUSIONS

Both the antibacterial pastes can be used effectively in non instrumental endodontic treatment of necrosed primary teeth and require more clinical trials to prove its efficacy.

Comparison of mechanical and chemomechanical methods of caries removal in deciduous and permanent teeth: a SEM study

BACKGROUND

Mechanical method of caries removal is associated with the removal of sound tooth structure, production of pain, heat, annoying sounds, and vibrations. Chemomechanical caries removal method is based on removal of only carious dentin leaving sound dentin intact.

AIM

The aim of this study was to compare the efficacy of mechanical and chemomechanical methods of caries removal in deciduous and permanent teeth.

STUDY DESIGN

A total of 30 carious teeth including 15 deciduous and 15 permanent teeth having dentinal caries selected randomly and cut into two halves through center of the lesion, were subjected to caries removal by mechanical (Group A), and chemomechanical methods (Group B). Time taken for removal of caries was noted with stopwatch. Samples were prepared and seen under the scanning electron microscope for the presence of bacterial colonies. Data were analyzed using statistical package for social sciences (SPSS) Software.

RESULTS

No significant difference was found for the presence of bacterial colonies in both groups of deciduous and permanent teeth; however, time taken for caries removal by the chemomechanical method was twice than the mechanical method.

CONCLUSION

despite the insignificant presence of bacterial colonies and twice time taken as compared to mechanical method, chemomechanical method was easy to introduce, was painless, did not form smear layer and conserved the sound tooth structure.

Effect of salt, drought and metal stress on essential oil yield and quality in plants

Essential oil extracted from plants is of high commercial value in medicine, cosmetics and perfumery. Enhancing yield and maintaining the quality of oil is of significant commercial importance. Production of oil in plants is dependent on various biotic and abiotic factors to which the plants are subjected during their growth. Plants are exposed to various degrees of stress on account of natural and human-induced factors. Salinization, drought and presence of heavy metals in the substratum cause substantial effect on the yield and quality of bioactive constituents in the oil. In many plants, the level and kind of stress have detrimental effects on the growth and development. This review provides an account of the studies on some common abiotic stresses to which essential oil plants are exposed during their growth period and their influence on quality and quantity of oil. The yield and quality vary in different plants and so is the response. Enhancing essential oil productivity is an important challenge, and understanding the role played by stress may offer significant advantages to the essential oil farmers and processing industry. Scientific evaluation of the data on many important but unexplored essential oil plants will also help in mitigating, ameliorating and minimizing the harmful effects caused by stress.

Effect of Salt, Drought and Metal Stress on Essential Oil Yield and Quality in Plants

Essential oil extracted from plants is of high commercial value in medicine, cosmetics and perfumery. Enhancing yield and maintaining the quality of oil is of significant commercial importance. Production of oil in plants is dependent on various biotic and abiotic factors to which the plants are subjected during their growth. Plants are exposed to various degrees of stress on account of natural and human-induced factors. Salinization, drought and presence of heavy metals in the substratum cause substantial effect on the yield and quality of bioactive constituents in the oil. In many plants, the level and kind of stress have detrimental effects on the growth and development. This review provides an account of the studies on some common abiotic stresses to which essential oil plants are exposed during their growth period and their influence on quality and quantity of oil. The yield and quality vary in different plants and so is the response. Enhancing essential oil productivity is an important challenge, and understanding the role played by stress may offer significant advantages to the essential oil farmers and processing industry. Scientific evaluation of the data on many important but unexplored essential oil plants will also help in mitigating, ameliorating and minimizing the harmful effects caused by stress.

Role of immunostimulatory molecules in poultry vaccines

Immunization by vaccination is the most suitable and safest method for preventing infectious diseases in the poultry worldwide. Vaccines alone cannot effectively protect birds from variety of pathogens under field conditions. The combined use of potent immunostimulants in vaccines is an alternative to increase the efficacy of vaccines that can be achieved by the development of better adjuvant. One such adjuvant is cytokine; cytokines have been used extensively as adjuvant in vaccines and are responsible for the type and extent of an immune response following vaccination. Although the innate immune system in birds is not fully characterized but their immune system is very much similar to that of mammals, and moreover with the recent discovery of a number of avian cytokine genes it is now possible to study their effectiveness in enhancing the immune response during vaccination. This review focuses on the recent studies and developments involving the role of immunomodulating agents especially cytokines of avian origin in poultry vaccines.

Role of Immunostimulatory Molecules in Poultry Vaccines

Immunization by vaccination is the most suitable and safest method for preventing infectious diseases in the poultry worldwide. Vaccines alone cannot effectively protect birds from variety of pathogens under field conditions. The combined use of potent immunostimulants in vaccines is an alternative to increase the efficacy of vaccines that can be achieved by the development of better adjuvant. One such adjuvant is cytokine; cytokines have been used extensively as adjuvant in vaccines and are responsible for the type and extent of an immune response following vaccination. Although the innate immune system in birds is not fully characterized but their immune system is very much similar to that of mammals, and moreover with the recent discovery of a number of avian cytokine genes it is now possible to study their effectiveness in enhancing the immune response during vaccination. This review focuses on the recent studies and developments involving the role of immunomodulating agents especially cytokines of avian origin in poultry vaccines.

High-sensitivity KRAS mutation detection in colorectal and lung cancer using SURVEYOR Nuclease scanning

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Background: Mutations of the KRAS gene in colorectal and lung cancers have been associated with lack of response to epidermal growth factor receptor (EGFR) inhibitor therapies. Here we describe a highly sensitive assay that identifies mutations by scanning the entire coding region of KRAS exons 2 and 3 using SURVEYOR Nuclease, an endonuclease that cleaves double-stranded heteroduplex DNA at base pair mismatch sites. Methods: DNA was extracted from formalin-fixed paraffin- embedded tissue sections from a set of 30 colorectal and lung cancer samples. Two amplicons covering the coding and splice junction regions of the KRAS gene exons 2 and 3 were PCR-amplified, hybridized to allow heteroduplex formation, incubated with SURVEYOR Nuclease and analyzed on the WAVE-HS DHPLC system. The sensitivity of SURVEYOR Nuclease mutation detection was assessed by creating serial dilutions of 50:50 mixtures of original PCR products from mutant samples with wild type amplicons from control DNA. Results: 6 samples were identified as KRAS mutant by WAVE-HS profiles containing two fragment peaks in addition to the full length amplicon peak, indicating SURVEYOR Nuclease cleavage at a mismatch site. Mutations were found in both exon 2 (codons 12, 13) and exon 3 (codon 59). Sequencing confirmed the KRAS mutations in these samples. Levels of mutant DNA as low as 2% (1 ng/ul) were identified by this method, consistent with other SURVEYOR-based assays. Conclusions: SURVEYOR Nuclease technology is a sensitive and comprehensive method for detecting mutation in KRAS.

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An impacted supplemental premolar in the mandible

Supernumerary teeth are rare anomalies of the maxillofacial complex that are more common in the maxilla than in the mandible. This article reports a case of an impacted supplemental type of supernumerary tooth in the mandibular arch, in the left premolar region. The etiology, types and treatment alternatives are discussed.

Influence of lead in soil on mycorrhizal development and plant growth of Cyamopsis tetragonoloba (Linn.) Taub

Growth of C. tetragonoloba suffered with increase in concentration of Pb in soil. Plant biomass declined significantly at concentrations above 60 ppm of Pb. Roots showed more pronounced impact as compared to shoots. At highest applied concentration of lead (100 ppm), fresh weight of fruits decreased by 33% and dry weight by 52% as compared to control. No significant impact was noticed on the development of mycorrhiza at lower concentrations (15-45 ppm) of lead contamination. At higher concentrations of Pb (60 and 75 ppm), there was a decrease in VAM colonization. VAM hyphae had irregular size and terminated abruptly in outer cortex of root. Number of VAM fungal spores in rhizosphere also decreased with increase in the edaphic Pb concentration.