Expression of snowdrop lectin (GNA) in transgenic rice plants confers resistance to rice brown planthopper

Snowdrop lectin (Galanthus nivalis agglutinin; GNA) has been shown previously to be toxic towards rice brown planthopper (Nilaparvata lugens; BPH) when administered in artificial diet. BPH feeds by phloem abstraction, and causes 'hopper burn', as well as being an important virus vector. To evaluate the potential of the gna gene to confer resistance towards BPH, transgenic rice (Oryza sativa L.) plants were produced, containing the gna gene in constructs where its expression was driven by a phloem-specific promoter (from the rice sucrose synthase RSs1 gene) and by a constitutive promoter (from the maize ubiquitin ubi1 gene). PCR and Southern analyses on DNA from these plants confirmed their transgenic status, and that the transgenes were transmitted to progeny after self-fertilization. Western blot analyses revealed expression of GNA at levels of up to 2.0% of total protein in some of the transgenic plants. GNA expression driven by the RSs1 promoter was tissue-specific, as shown by immunohistochemical localization of the protein in the non-lignified vascular tissue of transgenic plants. Insect bioassays and feeding studies showed that GNA expressed in the transgenic rice plants decreased survival and overall fecundity (production of offspring) of the insects, retarded insect development, and had a deterrent effect on BPH feeding. gna is the first transgene to exhibit insecticidal activity towards sap-sucking insects in an important cereal crop plant.

Immunohistochemical and developmental studies to elucidate the mechanism of action of the snowdrop lectin on the rice brown planthopper, Nilaparvata lugens (Stal)

Rice brown planthoppers (Nilaparvata lugens) were fed on artificial diet containing snowdrop lectin (Galanthus nivalis agglutinin; GNA), which has been shown to be toxic towards this insect pest. In addition to decreasing survival, the lectin affected development, reducing the growth rate of nymphs by approximately 50% when present at a concentration of 5.3&mgr;M. Immunolocalisation studies showed that lectin binding was concentrated on the luminal surface of the midgut epithelial cells within the planthopper, suggesting that GNA binds to cell surface carbohydrate moieties in the gut. Immunolabelling at a lower level was also observed in the fat bodies, the ovarioles, and throughout the haemolymph. These observations suggest that GNA is able to cross the midgut epithelial barrier, and pass into the insect's circulatory system, resulting in a systemic toxic effect. Electron microscope studies showed morphological changes in the midgut region of planthoppers fed on a toxic dose of GNA, with disruption of the microvilli brush border region. No significant proteolytic degradation of GNA was observed either in the gut or honeydew of planthoppers fed on lectin-containing diet. The presence of glycoproteins which bind GNA in the gut of the brown planthopper was confirmed using digoxigen-labeled lectins to probe blots of extracted gut polypeptides.

Expression and immunolocalisation of the snowdrop lectin, GNA in transgenic rice plants

Transgenic rice (Oryza sativa L.) plants generated through particle bombardment expressed high levels of an insecticidal protein (the snowdrop lectin, GNA) directed against sap-sucking insects. Engineered plants expressed GNA either constitutively or in a tissue specific manner, depending on the nature of the promoter used to drive expression of the gene. We used specific antibodies raised against GNA to localize its expression in phloem tissue in plants engineered with the rice sucrose synthase promoter driving GNA expression. We report here molecular, biochemical and immunological analyses for fifteen independently-derived transformants out of more than 200 plants we generated.

Methanobacterium formicicum as a target rumen methanogen for the development of new methane mitigation interventions: A review

Methanobacterium formicicum (Methanobacteriaceae family) is an endosymbiotic methanogenic Archaean found in the digestive tracts of ruminants and elsewhere. It has been significantly implicated in global CH₄ emission during enteric fermentation processes. In this review, we discuss current genomic and metabolic aspects of this microorganism for the purpose of the discovery of novel veterinary therapeutics. This microorganism encompasses a typical H₂ scavenging system, which facilitates a metabolic symbiosis across the H₂ producing cellulolytic bacteria and fumarate reducing bacteria. To date, five genome-scale metabolic models (iAF692, iMG746, iMB745, iVS941 and iMM518) have been developed. These metabolic reconstructions revealed the cellular and metabolic behaviors of methanogenic archaea. The characteristics of its symbiotic behavior and metabolic crosstalk with competitive rumen anaerobes support understanding of the physiological function and metabolic fate of shared metabolites in the rumen ecosystem. Thus, systems biological characterization of this microorganism may provide a new insight to realize its metabolic significance for the development of a healthy microbiota in ruminants. An in-depth knowledge of this microorganism may allow us to ensure a long term sustainability of ruminant-based agriculture.

Intergenomic evolution and metabolic cross-talk between rumen and thermophilic autotrophic methanogenic archaea

Methanobrevibacter ruminantium M1 (MRU) is a rumen methanogenic archaean that can be able to utilize formate and CO₂/H₂ as growth substrates. Extensive analysis on the evolutionary genomic contexts considered herein to unravel its intergenomic relationship and metabolic adjustment acquired from the genomic content of Methanothermobacter thermautotrophicus ΔH. We demonstrated its intergenomic distance, genome function, synteny homologs and gene families, origin of replication, and methanogenesis to reveal the evolutionary relationships between Methanobrevibacter and Methanothermobacter. Comparison of the phylogenetic and metabolic markers was suggested for its archaeal metabolic core lineage that might have evolved from Methanothermobacter. Orthologous genes involved in its hydrogenotrophic methanogenesis might be acquired from intergenomic ancestry of Methanothermobacter via Methanobacterium formicicum. Formate dehydrogenase (fdhAB) coding gene cluster and carbon monoxide dehydrogenase (cooF) coding gene might have evolved from duplication events within Methanobrevibacter-Methanothermobacter lineage, and fdhCD gene cluster acquired from bacterial origins. Genome-wide metabolic survey found the existence of four novel pathways viz. l-tyrosine catabolism, mevalonate pathway II, acyl-carrier protein metabolism II and glutathione redox reactions II in MRU. Finding of these pathways suggested that MRU has shown a metabolic potential to tolerate molecular oxygen, antimicrobial metabolite biosynthesis and atypical lipid composition in cell wall, which was acquainted by metabolic cross-talk with mammalian bacterial origins. We conclude that coevolution of genomic contents between Methanobrevibacter and Methanothermobacter provides a clue to understand the metabolic adaptation of MRU in the rumen at different environmental niches.

Functional Prediction and Assignment of Methanobrevibacter ruminantium M1 Operome Using a Combined Bioinformatics Approach

Methanobrevibacter ruminantium M1 (MRU) is a rod-shaped rumen methanogen with the ability to use H₂ and CO₂, and formate as substrates for methane formation in the ruminants. Enteric methane emitted from this organism can also be influential to the loss of dietary energy in ruminants and humans. To date, there is no successful technology to reduce methane due to a lack of knowledge on its molecular machinery and 73% conserved hypothetical proteins (HPs; operome) whose functions are still not ascertained perceptively. To address this issue, we have predicted and assigned a precise function to HPs and categorize them as metabolic enzymes, binding proteins, and transport proteins using a combined bioinformatics approach. The results of our study show that 257 (34%) HPs have well-defined functions and contributed essential roles in its growth physiology and host adaptation. The genome-neighborhood analysis identified 6 operon-like clusters such as hsp, TRAM, dsr, cbs and cas, which are responsible for protein folding, sudden heat-shock, host defense, and protection against the toxicities in the rumen. The functions predicted from MRU operome comprised of 96 metabolic enzymes with 17 metabolic subsystems, 31 transcriptional regulators, 23 transport, and 11 binding proteins. Functional annotation of its operome is thus more imperative to unravel the molecular and cellular machinery at the systems-level. The functional assignment of its operome would advance strategies to develop new anti-methanogenic targets to mitigate methane production. Hence, our approach provides new insight into the understanding of its growth physiology and lifestyle in the ruminants and also to reduce anthropogenic greenhouse gas emissions worldwide.

Partial Edentulism based on Kennedy's classifcation: an epidemiological study

BACKGROUND

The aim of this study was to determine the incidence of different Kennedy's classes of partial edentulism during 18 months period.

MATERIALS AND METHODS

Patients were clinically examined for various Kennedy's classes of partial edentulism in the outpatient department (OPD), prosthodontics, GPRDCH, Kurnool (Andhra Pradesh).

RESULTS

Of the total 1,420 OPD patients, Kennedy's class III was the most frequent classification encountered (62%) and followed by Kennedy's class I (18%), class II (11%), and class IV (9%) in decreasing order.

CONCLUSION

The patients with various Kennedy's classes of partial edentulism can be offered various treatment modalities like removable cast partial dentures, fixed partial dentures, over dentures and implant supported dentures. This study can be crucial for screening the population for incidence of tooth loss as a factor of gender and age. Clinical significance: Tooth loss appears to have an important role in the loss of esthetics and mastication. Study of incidence of various classes of partial edentulism provides clinically useful information for dental training and continuing education.

Kinetic modeling of Stickland reactions-coupled methanogenesis for a methanogenic culture

Studying amino acid catabolism-coupled methanogenesis is the important standpoints to decipher the metabolic behavior of a methanogenic culture. l-Glycine and l-alanine are acted as sole carbon and nitrogen sources for acidogenic bacteria. One amino acid is oxidized and another one is reduced for acetate production via pyruvate by oxidative deamination process in the Stickland reactions. Herein, we have developed a kinetic model for the Stickland reactions-coupled methanogenesis (SRCM) and simulated objectively to maximize the rate of methane production. We collected the metabolic information from enzyme kinetic parameters for amino acid catabolism of Clostridium acetobutylicum ATCC 824 and methanogenesis of Methanosarcina acetivorans C2A. The SRCM model of this study consisted of 18 reactions and 61 metabolites with enzyme kinetic parameters derived experimental data. The internal or external metabolic flux rate of this system found to control the acidogenesis and methanogenesis in a methanogenic culture. Using the SRCM model, flux distributions were calculated for each reaction and metabolite in order to maximize the methane production rate from the glycine–alanine pair. Results of this study, we demonstrated the metabolic behavior, metabolite pairing while mutually interact, and advantages of syntrophic metabolism of amino acid-directed methane production in a methanogenic starter culture.

New Visionary in Upper Airway Surgeries-THRIVE, a Tubeless Ventilation

THRIVE stands for Transnasal Humidified Rapid Insufflation Ventilatory Exchange. Usage of THRIVE technique is common in emergency settings and of late its usage in upper airway surgeries is gaining popularity. (1) To determine the operative time, total anaesthesia time, safety and efficacy of THRIVE in patients undergoing upper airway surgeries for varied pathologies. (2) To assess the surgeon's satisfaction and patients post-operative comfort. An observational study was from May 2019 to Oct 2020. Study was conducted through a detailed proforma which consists of patient demographic details, physical status, co-morbidities and various domains to assess the safety and efficacy of THRIVE. A total of 32 patients were divided into four groups depending on the type of surgery. We had 18 patients in microlaryngeal excision, six in direct laryngoscopy and biopsy, four in tracheostomy and four in balloon dilatation for subglottic stenosis groups. The mean operation time was 16 ± 2 min in the first three groups and 29 ± 0.8 in the fourth group. All the patients underwent successful surgeries without any episodes of desaturation, without complications and with good surgical satisfaction. THRIVE with appropriate safety precautions can be tried in patients undergoing various upper airway surgeries of short duration. All the patients in our study maintained stable vital parameters throughout the surgery. Initial results with the use of THRIVE as per our study and other studies are definitely encouraging to use THRIVE in upper airway surgeries with varied pathologies.

A case of invasive papillary breast carcinoma: Fierce façade with favorable prognosis

Invasive papillary carcinoma of the breast is a rare, distinct variant comprising approximately less than 1-2% of all newly diagnosed cases of breast carcinoma and is usually found in postmenopausal women with a more favorable prognosis. We report an unusual case in a 45-year-old perimenopausal female who came with a complaint of lump in right breast for duration of 1 year. A simple mastectomy was undertaken for histopathological study and immunohistochemistry (IHC) which showed characteristic features of an invasive papillary breast carcinoma. We present this case in view of its rarity and to highlight this clinicopathological subtype for its good prognosis and to avoid overtreatment.

Physical Properties of Heat Cure Denture Base Resin after Incorporation of Methacrylic Acid

Introduction

Heat cure acrylic resins are the most commonly used denture base materials. The important limitation is they may act as reservoir of microorganisms. The adherence of microorganisms can be reduced by chemical modification of the surface charge of denture base resin. Incorporation of methacrylic acid (MA) in the denture base resin gives a negative surface charge. A denture base having a negative surface charge may hinder the initial adhesion of microorganisms through repulsive electrostatic forces.

Aims and Objectives

The present in vitro study was performed to determine the effect of addition of antimicrobial agent MA on the flexural strength and surface roughness of heat cure denture base resin.

Materials and Methods

A total of 90 heat cure acrylic specimens were prepared. Of 90 specimens, 30 were prepared as Group I control group without addition of MA. Groups II and III specimens were prepared by adding 10% and 20% MA, respectively. Using universal testing machine and surface roughness tester, flexural strength and surface roughness of specimens measured.

Results

In the present study, decrease in the flexural strength was observed when the concentration of the MA increased in the denture base resin. A slight increase in the surface roughness was observed as the concentration of MA increased.

Hearing Loss-a Camouflaged Manifestation of COVID 19 Infection

The symptomatology of novel Severe Acute Respiratory Syndrome Corona virus type 2 infection runs the entire gamut of mild to moderate and serious illness among the affected individuals. As listed in recent literature, respiratory, cardiovascular, gastrointestinal, olfactory and gustatory systems are commonly involved. With the growing knowledge about the disease, varied manifestations have been identified and lately, otorhinolaryngology dysfunctions in COVID 19 have been described. Hearing loss in COVID era is one of the emerging areas of concern and calls for further research in the field for the better understanding and treatment of this entity. This study was designed to assess the audiological profile among 100 mild to moderately affected COVID-19 individuals, so as to make a contribution to the emerging literature on otologic manifestations in COVID 19. In our case series, high frequency hearing loss and referred OAE was noted among significant number of COVID 19 positive patients. This was even observed in patients without any otologic symptoms. Hence, early identification and intervention if required helps to give a better quality of life to the patient.

Drug-Induced Sleep Endoscopy as a Selection Tool for Surgical Management of Obstructive Sleep Apnoea Syndrome: Our Personal Experience

The role of Drug-induced sleep endoscopy as a selection tool for surgical management of obstructive sleep apnoea syndrome.

SOURCE OF DATA

Polysomnography proved OSA patients, who are planned for surgery in dept. of ENT AND HEAD& NECK, JSS Hospital, Mysore.

STUDY DESIGN

A prospective clinical study.

METHOD

30 Polysomnography proved OSA patients, age between 20 and 60 years have been selected for Drug Induced Sleep Endoscopy (DISE) after taking informed consent for proposed surgery. Inj propofol infusion given throughout the DISE procedure and upper airway nasal endoscopy performed for assessment of site of collapse (Retropalatal, Retrolingual, Hypopharyngral), type of collapse (circumferential, lateral) and severity of obstruction, Lowest SpO₂, apnoeic episodes and DISE findings were recorded. Out of these thirty patients 90% were male and 10% were female, observed that 66.7% of males and 40.7% of females belonged to 31-40 age group, and BMI of 63.3% of patient population were overweight, 20% were obese and 5% were normal. Mean fall in SpO₂ was 90.20 ± 2.77 in normal subjects, 83.05 ± 5.14 in overweight subjects and 68.83 ± 9.11 in obese subjects. Normal subjects had 0.4 ± 0.9 apnoeic episodes, overweight subjects had 0.9 ± 1.6 episodes and obese subjects had 4.0 ± 2 apnoeic episodes. We observed that 40% had retropalatal airway collapse, 23.3% had airway obstruction at the base of the tongue, 20% had airway obstruction with floppy epiglottis, 12% multiple level collapse, 6.7% of patient population had grade 4 enlarged tonsils, 3.3% had lateral pharyngeal wall collapse, and 0% hypopharyngeal collapse. Out of 30, 29 Patients underwent surgery (Expansion sphincter pharyngo plasty-14, Hyoid advancement-4, Uuvulopalatoplasty-10, Epiglottic surgery-6, Zeta pharyngoplasty-2, midline glossectomy-3, Endoscopic septoplasty-5, Inferio turbinoplasty-2, LASSER Assisted lingual tonsillectomy-1), All these 29 patient were followed for 3 months, at the end of 3rd month again Each subject was evaluated with a baseline Epworth Sleepiness Scale and LEVEL-3 PSG, the results were impressive with statistically significant. DISE is a dynamic, safe, and easy-to-perform technique that visualizes, the anatomical sites of snoring or apneas for assessment site of collapse (Retropalatal, Retrolingual, Hypopharyngral), type of collapse (Circumferential, Lateral) and severity of obstruction and guides the design of a tailor-made treatment plan for a OSA SURGEON in individual cases, which will improves perioperative outcome.

Hybrid Particle Swarm and Ranked Firefly Metaheuristic Optimization-Based Software Test Case Minimization

Software testing is a valuable and time-consuming activity that aims to improve the software quality. Due to its significance, combinatorial testing focuses on fault identification by the interaction of small amount of input factors. But, deep testing is not sufficient due to time or resources availability. To select the optimal test cases with least computation time, Hybrid Multi Criteria Particle Swarm and Ranked Firefly Metaheuristic Optimization(HMCPW-RFMO) technique are introduced. Initially, the population of the test cases is randomly initialized. Then the fitness is calculated by the pairwise coverage, execution cost, fault detection capability and average execution frequency. RFM approach starts with ‘n’ fireflies. The light intensity of each firefly gets initialized.If the light intensity of one firefly is minor than the other one, it moves near the brighter one. Next, the rank is given to the firefly based on their light intensity. Lastly, the high ranked firefly is chosen as a global best solution.The result reveals that HMCPW-RFMO technique improves the software quality.

Chromosome pairing in F1 hybrid Arachis hypogaea L. X A. monticola Krap. et Rig

Chromosome pairing at pachytene in the F1 hybrid Arachis hypogaea X A. monticola was studied. Pairing was remarkably regular and segment by segment except for some minor differences. Chromosomes were identified individually at pachytene. The idiograms of A. hypogaea and A. monticola were identical. Meiosis was regular and fertility was high in the hybrid indicating that the taxa concerned were very closely related.