The implementation of graphene-based aerogel in the field of supercapacitor.

Graphene and graphene-based hybrid materials have emerged as an outstanding supercapacitor electrode material primarily because of their excellent surface area, high electrical conductivity, and improved thermal, mechanical, electrochemical cycling stabilities. Graphene alone exhibits electric double layer capacitance (EDLC) with low energy density and high power density. The use of aerogels in a supercapacitor is a pragmatic approach due to its extraordinary properties like ultra-lightweight, high porosity and specific surface area. The aerogels encompass a high volume of pores which leads to easy soak by the electrolyte and fast charge-discharge process. Graphene aerogels assembled into three-dimensional (3D) architecture prevent there stacking of graphene sheets and maintain the high surface area and hence excellent cycling stability and rate capacitance. However, the energy density of graphene aerogels is limited due to EDLC type of charge storage mechanism. Consequently, 3D graphene aerogel coupled with pseudocapacitive materials such as transition metal oxides, metal hydroxides, conducting polymers, nitrides, chalcogenides show an efficient energy density and power density performance due to the presence of both types of charge storage mechanisms. This laconic review focuses on the design and development of graphene-based aerogel in the field of the supercapacitor. This review is an erudite article about methods, technology and electrochemical properties of graphene aerogel.

Linkage disequilibrium mapping for grain Fe and Zn enhancing QTLs useful for nutrient dense rice breeding.

BACKGROUND: High yielding rice varieties are usually low in grain iron (Fe) and zinc (Zn) content. These two micronutrients are involved in many enzymatic activities, lack of which cause many disorders in human body. Bio-fortification is a cheaper and easier way to improve the content of these nutrients in rice grain. RESULTS: A population panel was prepared representing all the phenotypic classes for grain Fe-Zn content from 485 germplasm lines. The panel was studied for genetic diversity, population structure and association mapping of grain Fe-Zn content in the milled rice. The population showed linkage disequilibrium showing deviation of Hardy-Weinberg's expectation for Fe-Zn content in rice. Population structure at K = 3 categorized the panel population into distinct sub-populations corroborating with their grain Fe-Zn content. STRUCTURE analysis revealed a common primary ancestor for each sub-population. Novel quantitative trait loci (QTLs) namely qFe3.3 and qFe7.3 for grain Fe and qZn2.2, qZn8.3 and qZn12.3 for Zn content were detected using association mapping. Four QTLs, namely qFe3.3, qFe7.3, qFe8.1 and qFe12.2 for grain Fe content were detected to be co-localized with qZn3.1, qZn7, qZn8.3 and qZn12.3 QTLs controlling grain Zn content, respectively. Additionally, some Fe-Zn controlling QTLs were co-localized with the yield component QTLs, qTBGW, OsSPL14 and qPN. The QTLs qFe1.1, qFe3.1, qFe5.1, qFe7.1, qFe8.1, qZn6, qZn7 and gRMm9-1 for grain Fe-Zn content reported in earlier studies were validated in this study. CONCLUSION: Novel QTLs, qFe3.3 and qFe7.3 for grain Fe and qZn2.2, qZn8.3 and qZn12.3 for Zn content were detected for these two traits. Four Fe-Zn controlling QTLs and few yield component QTLs were detected to be co-localized. The QTLs, qFe1.1, qFe3.1, qFe5.1, qFe7.1, qFe8.1, qFe3.3, qFe7.3, qZn6, qZn7, qZn2.2, qZn8.3 and qZn12.3 will be useful for biofortification of the micronutrients. Simultaneous enhancement of Fe-Zn content may be possible with yield component traits in rice.

Association mapping reveals multiple QTLs for grain protein content in rice useful for biofortification.

Rice is the staple food for majority of the global population. But, rice grain has low protein content (PC). Mapping of QTLs controlling grain PC is essential for enhancement of the trait through breeding programs. A shortlisted panel population for grain protein content was studied for genetic diversity, population structure and association mapping for grain PC. Phenotyping results showed a wide variation for grain PC. The panel population showed a moderate level of genetic diversity estimated through 98 molecular markers. AMOVA and structure analysis indicated linkage disequilibrium for grain PC and deviation of Hardy-Weinberg's expectation. The analysis showed 15% of the variation among populations and 73% among individuals in the panel population. STRUCTURE analysis categorized the panel population into three subpopulations. The analysis also revealed a common primary ancestor for each subpopulation with few admix individuals. Marker-trait association using 98 molecular markers detected 7 strongly associated QTLs for grain PC by both MLM and GLM analysis. Three novel QTLs qPC3.1, qPC5.1 and qPC9.1 were detected for controlling the grain PC. Four reported QTLs viz., qPC3, QPC8, qPC6.1 and qPC12.1 were validated for use in breeding programs. Reported QTLs, qPC6, qPC6.1 and qPC6.2 may be same QTL controlling PC in rice. A very close marker RM407 near to protein controlling QTL, qProt8 and qPC8, was detected. The study provided clue for simultaneous improvement of PC with high grain yield in rice. The strongly associated markers with grain PC, namely qPC3, qPC3.1, qPC5.1, qPC6.1, qPC8, qPC9.1 and qPC12.1, will be useful for their pyramiding for developing protein rich high yielding rice.

Role of lactoferrin and lactoferrin-derived peptides in oral and maxillofacial diseases.

The oral cavity harbors different taxonomic groups, the evolutionary coexistence of which develops the oral ecosystem. These resident microorganisms can alter the balance between the physiologic and pathologic conditions that affect the host, both locally and systemically. This highly sophisticated nature of the oral cavity poses a significant therapeutic challenge. Numerous human and animal studies have been conducted to potentiate the efficacy and competence of current treatments of pathologic conditions as well as to develop novel therapeutic modalities. One of these studies is the use of the potent antimicrobial agent lactoferrin (LF), which was originally derived from the host immune system. LF is an 80-kDa glycoprotein that has a free iron sequestration mechanism with evident antimicrobial, anti-tumor, and immunomodulatory properties. A wide range of active peptides have been isolated from the N-terminal region of LF, which possess antimicrobial activities. In this review, we discuss the role of LF and LF-derived peptides under a heterogeneous group of oral and maxillofacial conditions, including bacterial, fungal, viral infections; head and neck cancers; xerostomia; and implantology-bone-related manifestations.

Ureterocolic fistula diagnosed on the basis of diuretic renogram and direct radionuclide cystography.

Ureterocolic fistulae are a rare phenomenon and are most commonly seen secondary to obstructive ureteric calculi. These are usually diagnosed on barium enema or intravenous urography. Most of the times, more than one investigation is needed to confirm the findings. We present a case of iatrogenically-induced ureterocolic fistula, diagnosed on renogram and direct radionuclide cystography. This case showcases the possibility of using a renogram study as a diagnostic tool for a suspected ureterocolic fistula. A renogram study also enables to asess the renal function, which is essential in deciding the management.

Influenza A(H1N1)pdm09 outbreak detected in inter-seasonal months during the surveillance of influenza-like illness in Pune, India, 2012-2015.

An outbreak of influenza A(H1N1)pdm09 was detected during the ongoing community-based surveillance of influenza-like illness (ILI). Among reported 119 influenza A(H1N1)pdm09 cases (59 cases in the year 2012 and 60 cases in 2015) in summer months, common clinical features were fever (100%), cough (90·7%), sore throat (85·7%), nasal discharge (48·7%), headache (55·5%), fatigue (18·5%), breathlessness (3·4%), and ear discharge (1·7%). Rise in ILI cases were negatively correlated with the seasonal factors such as relative humidity (Karl Pearson's correlation coefficient, i.e. r = -0·71 in the year 2012 and r = -0·44 in the year 2015), while rise in ILI cases were positively correlated with the temperature difference (r = 0·44 in the year 2012 and r = 0·77 in the year 2015). The effective reproduction number R, was estimated to be 1·30 in 2012 and 1·64 in 2015. The study highlights the rise in unusual influenza activity in summer month with high attack rate of ILI among children aged ⩽9 years. Children in this age group may need special attention for influenza vaccination. Influenza A(H1N1)pdm09 outbreak was confirmed in inter-seasonal months during the surveillance of ILI in Pune, India, 2012-2015.

Synchronous behaviour of two interacting oscillatory systems undergoing quasiperiodic route to chaos.

Thermoacoustic instability, caused by a positive feedback between the unsteady heat release and the acoustic field in a combustor, is a major challenge faced in most practical combustors such as those used in rockets and gas turbines. We employ the synchronization theory for understanding the coupling between the unsteady heat release and the acoustic field of a thermoacoustic system. Interactions between coupled subsystems exhibiting different collective dynamics such as periodic, quasiperiodic, and chaotic oscillations are addressed. Even though synchronization studies have focused on different dynamical states separately, synchronous behaviour of two coupled systems exhibiting a quasiperiodic route to chaos has not been studied. In this study, we report the first experimental observation of different synchronous behaviours between two subsystems of a thermoacoustic system exhibiting such a transition as reported in Kabiraj et al. [Chaos 22, 023129 (2012)]. A rich variety of synchronous behaviours such as phase locking, intermittent phase locking, and phase drifting are observed as the dynamics of such subsystem change. The observed synchronization behaviour is further characterized using phase locking value, correlation coefficient, and relative mean frequency. These measures clearly reveal the boundaries between different states of synchronization.

Preventing damage to miniature-loudspeaker by means of dynamic detection of excessive diaphragm displacement.

The rapid development of consumer electronics and the extensive use of mobile devices require the ample use of miniature-loudspeakers for audio applications. The demand for better sound pushes manufacturers to design digital signal processing (DSP) chips (smart amplifiers), which in turn could cause unpleasant sound due to distortion and parameter nonlinearity or transducer damage caused by large diaphragm excursion or voice-coil (VC) burn. This article presents a methodology for nonlinear parameter estimation using an inverse method and displacement limiter for large VC displacement-dependent transducer damage prevention. A set of transduction equations is employed to inversely determine parameters using a polynomial expression. The appropriate selection of an objective function incorporating the unknown vector of nonlinear parameters leads to the adjoint problem that requires a gradient solution. A numerical solver is provided to obtain the VC displacement, current, and derivatives using a robust hybrid spline differential method. The dynamic limiter is proposed to control the peak values of the VC velocity so as to limit an excessive displacement which prevents impulsive damage to the receiver and further application of the DSP board. Numerical and experimental results indicate that the proposed method has high efficiency and can be widely used in transducer applications.

Novel genetic tools to tackle c-di-GMP-dependent signalling in Pseudomonas aeruginosa.

AIMS: To develop new genetic tools for studying 3',5'-cyclic diguanylic acid (c-di-GMP) signalling in Pseudomonas aeruginosa. METHODS AND RESULTS: Plasmid pPcdrA::lux, carrying a transcriptional fusion between the c-di-GMP responsive promoter PcdrA and the luxCDABE reporter genes, has been generated and validated in purpose-built P. aeruginosa strains in which c-di-GMP levels can be increased or reduced upon arabinose-dependent induction of c-di-GMP synthetizing or degrading enzymes. CONCLUSIONS: The reporter systems described so far were able to detect a decrease in the c-di-GMP levels only in engineered strains overproducing c-di-GMP. Conversely, pPcdrA::lux could be used for studying any process or chemical compound expected to cause both an increase or a decrease with respect to the c-di-GMP levels produced by wild type P. aeruginosa. Another relevant aspect of this study has been the development of novel and improved genetic devices for the fine arabinose-dependent control of c-di-GMP levels in P. aeruginosa. SIGNIFICANCE AND IMPACT OF THE STUDY: The genetic tools developed and validated in this study could facilitate investigations tackling the c-di-GMP signalling process on different fields, from cellular physiology to drug-discovery research.

Push-out bond strength of root fillings made with C-Point and BC sealer versus gutta-percha and AH Plus after the instrumentation of oval canals with the Self-Adjusting File versus WaveOne.

AIM: To compare the push-out bond strength exhibited by root fillings performed with either C-Point and Endosequence® BC sealer™ (BC Sealer) or gutta-percha and AH Plus® after the instrumentation of oval canals with either the Self-Adjusting File (SAF) System or WaveOne (WO) reciprocating file. METHODOLOGY: Eighty extracted premolars were selected and divided randomly into the following four groups (n = 20): group 1, SAF instrumentation and filling using gutta-percha and AH Plus sealer; group 2, SAF instrumentation and C-Point and BC sealer filling; group 3, WO instrumentation and filling using gutta-percha and AH Plus sealer; and group 4, WO instrumentation and filling with C-Point and BC sealer. Sodium hypochlorite (5.25%) and EDTA (17%) were used as irrigants for all groups. After the sealer was set completely, the teeth were prepared for micro push-out assessment using 1.0-mm-thick root slices. Loading was performed with a universal testing machine at a speed of 0.5 mm min(-1) . Two-way anova and Student's t-test for pairwise comparisons were used to compare groups. RESULTS: All specimens filled with C-Point and BC sealer were associated with significantly higher push-out bond strength compared with gutta-percha and AH Plus sealer (P < 0.001). The bond strength was higher for the coronal and apical samples of the C-Point/BC sealer/SAF group (6.6 ± 0.3 and 3.2 ± 0.3 MPa) versus those of the gutta-percha/AH Plus/WO group (4.8 ± 0.3 and 1.8 ± 0.3 MPa), by 38% and by 80% in the coronal and apical parts, respectively (P < 0.001, P < 0.0001). Adhesive bond failure was more common in the WaveOne-instrumented group in general and in the buccal and lingual recesses in this group in particular. CONCLUSIONS: In oval canals, the instrument used and the root filling material significantly affected the push-out values of root fillings. The highest value was recorded in oval root canals instrumented with the SAF System and filled with C-Point and BC sealer, whereas the lowest strength was noted in oval canals instrumented with WaveOne and filled with gutta-percha and AH Plus sealer.

Fn14 receptor promotes invasive potential and metastatic capacity of non-small lung adenocarcinoma cells through the up-regulation of integrin α6.

UNLABELLED: Lung cancer is one of the leading cause of cancer-related death around the world with the majority of diagnoses being non-small cell lung cancer (NSCLC). Given the poor survival rate and efficacy of current therapy for NSCLC, there is a need to identify and develop new therapeutic targets for treatment. We have observed significantly up-regulated levels of Fn14 in clinical samples of lung cancer relative to normal adjacent tissue. However, the functional role of Fn14 in these tumors is not understood yet. We used RT-PCR to establish the Fn14 expression profile in various NSCLC cell lines. Using isogenic variants of H460 NSCLC cell line with low, intermediate and high Fn14 expression as a cellular model, we determined that increased levels of integrin α6 in cells over-expressing Fn14 is suggestive of an important role of α6ß1-fn14 interactions in motility of lung carcinoma and formation of metastases. Enhanced levels of Fn14 correlated with higher tumor cell migration and invasion in an MMP-1 dependent manner. Cells over-expressing Fn14 showed increased in vivo tumor formation with metastatic capacity to lymph nodes, lungs and liver. Thus, this research may be a step toward developing improved treatment strategies for NSCLC by improved detection and inhibition of metastases. KEYWORDS: Fn14, TNFRSF12A, non-small cell lung cancer, H460 cells, motility, tumor formation and metastasis, integrin α6.

Stability Analysis and Identification of Superior Hybrids in Pearl Millet [Pennisetum glaucum (L.) R. Br.] Using the Multi Trait Stability Index.

Pearl millet stands as an important staple food and feed for arid and semi-arid regions of India and South Africa. It is also a quick supplier of important micronutrients like Fe and Zn via grain to combat micronutrient deficiencies among people in developing countries. India has notably spearheaded advancements in pearl millet production and productivity through the All India Coordinated Pearl Millet Improvement Project. There were 21 hybrids evaluated over arid and semi-arid ecologies of the western and southern regions of India. AMMI and GGE biplot models were adopted to recommend a specific hybrid for the particular locality. A joint analysis of variation indicated a significant genotype-environment interaction for most of the agronomical and grain micronutrient parameters. Pearson's correlation values dissected the significant and positive correlation among agronomic traits and the negative correlation with grain micronutrient traits. GGE biplot analysis recommended the SHT 106 as a dual-purpose hybrid and SHT 115 as a biofortified hybrid for the grain's Fe and Zn content. SHT 110 and SHT 108 were selected as stable and high grain yield-producing hybrids across all environments and specifically for E1, E2, and E4 as per the Which-Won-Where and What biplot. SHT 109 and SHT 103 hybrids were stable and high dry fodder yield-producing hybrids across all environments. In this study, the Multi-Trait Stability Index (MTSI) was employed to select the most stable and high-performing hybrids for all traits. It selected SHT 120, SHT 106, and SHT 104 for stability and great performance across all environments. These findings underscored the significance of tailored hybrid recommendations and the potential of pearl millet in addressing both food security and malnutrition challenges in various agro-ecological regions.

Genome sequence of Janibacter hoylei MTCC8307, isolated from the stratospheric air.

Janibacter hoylei MTCC8307 was isolated from stratospheric air at an altitude of 41.4 km over Hyderabad, India. Here, we present the draft genome of Janibacter hoylei MTCC8307, which contains 3,139,099 bp with a G+C content of 72.8 mol%, 2,972 protein-coding genes, and 57 structural RNAs.

Investigations on silver/polyaniline electrodes for electrochemical supercapacitors.

Polyaniline (PANI) and silver doped polyaniline (Ag/PANI) thin films were deposited on stainless steel substrates by a dip coating technique. To study the effect of doping concentration of Ag on the specific capacitance of PANI the concentration of Ag was varied from 0.3 to 1.2 weight percent. Fourier transform-infrared and Fourier transform-Raman spectroscopy, and energy dispersion X-ray techniques were used for the phase identification and determination of the doping content in the PANI films, respectively. The surface morphology of the films was examined by Field Emission Scanning Electron Microscopy, which revealed a nanofiber like structure for PANI and nanofibers with bright spots of Ag particles for the Ag/PANI films. There was decrease in the room temperature electrical resistivity of the Ag/PANI films of the order of 10(2) with increasing Ag concentration. The supercapacitive behavior of the electrodes was tested in a three electrode system using 1.0 M H(2)SO(4) electrolyte. The specific capacitance increased from 285 F g(-1) (for PANI) to 512 F g(-1) for Ag/PANI at 0.9 weight percent doping of Ag, owing to the synergic effect of PANI and silver nanoparticles. This work demonstrates a simple strategy of improving the specific capacitance of polymer electrodes and may also be easily adopted for other dopants.

Deviated nasal septum hinders intranasal sprays: a computer simulation study.

BACKGROUND: This study investigates how deviated nasal septum affects the quantity and distribution of spray particles, and examines the effects of inspiratory airflow and head position on particle transport. METHODS: Deposition of spray particles was analysed using a three-dimensional computational fluid dynamics model created from a computed tomography scan of a human nose with leftward septal deviation and a right inferior turbinate hypertrophy. Five simulations were conducted using FluentTM software, with particle sizes ranging from 20-110 μm, a spray speed of 3 m/s, plume angle of 68(deg), and with steady state inspiratory airflow either present (15.7 L/min) or absent at varying head positions. RESULTS: With inspiratory airflow present, posterior deposition on the obstructed side was approximately four times less than the contralateral side, regardless of head position, and was statistically significant. When airflow was absent, predicted deposition beyond the nasal valve on the left and right sides were between 16% and 69% lower and positively influenced by a dependent head position. CONCLUSION: Simulations predicted that septal deviation significantly diminished drug delivery on the obstructed side. Furthermore, increased particle penetration was associated with presence of nasal airflow. Head position is an important factor in particle deposition patterns when inspiratory airflow is absent.

Genetic characterization of vaccine and field strains of serotype A foot-and-mouth disease virus from India.

Extreme antigenic and genetic heterogeneity of serotype A foot-and-mouth disease virus (FMDV) population has resulted in change of vaccine strains in India twice in the last decade. In such a situation, complete characterization of the vaccine strains is imperative. With regard to the frequent outbreaks of this disease, FMDV field strains are also of interest. Therefore three vaccine strains and two field strains of type A FMDV from India were completely sequenced and the obtained sequences were subjected to sequence and phylogenetic analyses. Based on the complete coding region, all the Indian strains clustered in the Asia topotype and exhibited a more than 11% nt divergence from the other Asian strains. The 5'-UTR of some Indian strains revealed block deletions of 43 and 86 nt corresponding to the pseudoknot region. Amino acids S44 in VP2 and F164 in VP1 were found to be the exclusive signatures for the Asia topotype. The vaccine strains differed at 65 aa positions in the capsid region, 13 of them antigenically critical. Variability at such positions is likely to affect the antigenic profile of these strains. Complete genome sequences of the vaccine strains presented here could serve as the reference for any comparative genomics in future.

Assessment of quality of life of the patients with diabetic retinopathy using National Eye Institute Visual Functioning Questionnaire (VFQ-25).

BACKGROUND: Diabetes affects most of the organs causing macrovascular and microvascular complications. Diabetic retinopathy (DR) results from the prolonged uncontrolled hyperglycemia which causes impairment of vision. Quality of life (QoL) of patients with DR is affected due to vision loss. National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25) is the questionnaire used to study the effect of DR on QoL. OBJECTIVES: To assess the QoL of the patients with DR. MATERIALS AND METHODS: The study enrolled 149 (male-104 and female 45) patients with DR. The previous translated and validated version of NEI-VFQ-25 questionnaire was used in the study. RESULTS: Cronbach alpha for internal consistency was between 0.6 and 0.8. The male patient showed significantly higher (p<0.05) QoL scores (60.73±1.63) as compared to the female patients (53.15±2.84). Hypertensive patients showed poor QoL as compared to non-hypertensive patients. The patients with a history of diabetes for 16-30 yrs. showed better QoL as compared to other patients. CONCLUSION: DR affects the QoL of life of patients. Routine assessment of QoL using NEI-VFQ-25 questionnaire would be useful for physicians and health care team.

Population genetic structure and association mapping for iron toxicity tolerance in rice.

Iron (Fe) toxicity is a major abiotic stress which severely reduces rice yield in many countries of the world. Genetic variation for this stress tolerance exists in rice germplasms. Mapping of gene(s)/QTL controlling the stress tolerance and transfer of the traits into high yielding rice varieties are essential for improvement against the stress. A panel population of 119 genotypes from 352 germplasm lines was constituted for detecting the candidate gene(s)/QTL through association mapping. STRUCTURE, GenAlEx and Darwin softwares were used to classify the population. The marker-trait association was detected by considering both the Generalized Linear Model (GLM) and Mixed Linear Model (MLM) analyses. Wide genetic variation was observed among the genotypes present in the panel population for the stress tolerance. Linkage disequilibrium was detected in the population for iron toxicity tolerance. The population was categorized into three genetic structure groups. Marker-trait association study considering both the Generalized Linear Model (GLM) and Mixed Linear Model (MLM) showed significant association of leaf browning index (LBI) with markers RM471, RM3, RM590 and RM243. Three novel QTL controlling Fe-toxicity tolerance were detected and designated as qFeTox4.3, qFeTox6.1 and qFeTox10.1. A QTL reported earlier in the marker interval of C955-C885 on chromosome 1 is validated using this panel population. The present study showed that QTL controlling Fe-toxicity tolerance to be co-localized with the QTL for Fe-biofortification of rice grain indicating involvement of common pathway for Fe toxicity tolerance and Fe content in rice grain. Fe-toxicity tolerance QTL qFeTox6.1 was co-localized with grain Fe-biofortification QTLs qFe6.1 and qFe6.2 on chromosome 6, whereas qFeTox10.1 was co-localized with qFe10.1 on chromosome 10. The Fe-toxicity tolerance QTL detected from this mapping study will be useful in marker-assisted breeding programs.

Developmental regulation of lck gene expression in T lymphocytes.

In the mouse and human, mRNA transcripts encoding the lymphocyte-specific protein tyrosine kinase p56lck are derived from two separate promoters resulting in heterogeneity in the 5' untranslated region sequence. The proximal promoter lies just 5' to the coding region for the gene and is active only in thymocytes. In contrast, the distal promoter lies 34 kilobases (kb) 5' in the human, and is active both in thymocytes and mature peripheral T cells. As previously reported, transgenic mice bearing functional proximal promoter sequence juxtaposed with the SV40 large T antigen gene invariably develop lymphoid tumors confined to the thymus. In the current work, transgenic mice bearing a 2.6-kb fragment of the human distal promoter fused to the SV40 large T antigen gene express large T antigen in thymocytes and in peripheral lymphoid cells, and develop tumors of both the thymus and the peripheral lymphoid organs. The ability of the human distal promoter to function appropriately in transgenic mice is consistent with the strong similarity observed between the mouse and human distal promoter sequences. With the exception of a single short interval that serves as a target for binding of nuclear factors, significant sequence similarity is not seen when the distal and proximal promoter sequences are compared. Hence, developmentally regulated, lineage-specific transcription of the lck gene is mediated by distinct promoter sequences that appear to be capable of functioning independently.

Human oral cancers have altered expression of Bcl-2 family members and increased expression of the anti-apoptotic splice variant of Mcl-1.

Expression of Bcl-2 family proteins in tumours can modulate apoptosis, influencing tumour behaviour and treatment. To investigate their role in oral tumourigenesis, nine Bcl-2 family transcripts were examined in three oral cell lines and 25 oral tumours, using ribonuclease protection assay. Since Mcl-1 mRNA was elevated in these samples, Mcl-1 splice variants were assessed by RT-PCR and Mcl-1 protein was studied in normal, premalignant and malignant oral tissues and cell lines, by immunohistochemistry and/or immunoblotting. The cell lines exhibited significantly higher levels of 7/9 Bcl-2 family transcripts as compared to those in normal tongue, and significantly higher (p=0.030, p=0.004) anti-apoptotic versus pro-apoptotic transcripts. Elevated Mcl-1 mRNA was observed in 11/25 (44%) tumours as compared to normal tissues with a five- to ten-fold higher expression of full-length anti-apoptotic Mcl-1 transcript versus the pro-apoptotic short isoform. Strong cytoplasmic Mcl-1 immunoreactivity was detected predominantly in differentiated epithelia in 27/33 (82%) oral tumours, 18/20 (90%) leukoplakia, 25/30 (83%) submucous fibrosis and 3/3 oral cell lines, with weak staining in 8/15 (53%) normal mucosa samples. Mcl-1 positivity in malignant and premalignant tissues was comparable but significantly higher (p<0.01) than that in normal mucosa. The expression of bcl-2 family genes, including Mcl-1 in tumours, did not correlate significantly with clinicopathological parameters. This is the first report delineating the in vivo expression patterns of Mcl-1 protein and Mcl-1 transcripts in oral cancers and premalignant lesions. The observed imbalance between expression of anti-apoptotic and pro-apoptotic Bcl-2 family genes may promote survival in the oral cell lines. Since the majority of oral tumours associated with tobacco-chewing evolve from premalignant lesions, the sustained expression of full-length anti-apoptotic Mcl-1 protein in these tissues suggests an important role for Mcl-1, early in oral cancer pathogenesis in protecting cells from apoptosis via neutralization of pro-apoptotic members and could be a potential therapeutic target for oral cancers.