DNA double-strand breaks cooperate with loss of Ink4 and Arf tumor suppressors to generate glioblastomas with frequent Met amplification

Glioblastomas (GBM) are highly radioresistant and lethal brain tumors. Ionizing radiation (IR)- induced DNA double-strand breaks (DSBs) are a risk factor for the development of GBM. In this study, we systematically examined the contribution of IR-induced DSBs to GBM development using transgenic mouse models harboring brain-targeted deletions of key tumor suppressors frequently lost in GBM, namely Ink4a, Ink4b, Arf, and/or PTEN. Using low linear energy transfer (LET) X-rays to generate simple breaks or high LET Fe ions to generate complex breaks, we found that DSBs induce high-grade gliomas in these mice which, otherwise, do not develop gliomas spontaneously. Loss of Ink4a and Arf was sufficient to trigger IR-induced glioma development but additional loss of Ink4b significantly increased tumor incidence. We analyzed IR-induced tumors for copy number alterations (CNAs) to identify oncogenic changes that were generated and selected for as a consequence of stochastic DSB events. We found Met amplification to be the most significant oncogenic event in these radiation-induced gliomas. Importantly, Met activation resulted in expression of Sox2, a GBM cancer stem cell (CSC) marker, and was obligatory for tumor formation. In sum, these results indicate that radiation-induced DSBs cooperate with loss of Ink4 and Arf tumor suppressors to generate high-grade gliomas that are commonly driven by Met amplification and activation

MRV BRAIN NORMALANATOMICAL VARIANTS IN INDIA POPULATION

Introduction Knowledge of variations in the cerebral dural venous sinus anatomy seen on magnetic resonance (MR) venography is essential to avoid over-diagnosis of cerebral venous sinus thrombosis (CVST). Very limited data is available on gender difference of the cerebral dural venous sinus anatomy variations Materials and Methods A retrospective study was conducted in NRI medical college in the Department of Radiodiagnosis for a duration of 3 years to study the normal anatomy of the intracranial venous system and its normal variation, as depicted by 3D MR venography, in normal adults and any gender-related differences. Results A total of (46 men, 54 women, age range 12 to 81 years), were included in the study. Most common indication for MR venography was headache (80%). Hypoplastic left transverse sinus was the most common anatomical variation in (25%) patients. Left transverse sinus was hypoplastic in more commonly in male in comparison to females (13 versus 12). Most common variation of superior sagittal sinus (SSS) was hypoplastic anterior one third SSS ,. Conclusion Hypoplastic left transverse sinus is the most common anatomical variation and more common in male compared to female in the present study. Other anatomical variations of dural venous sinuses are not significantly differ among both genders.</jats:p

​Studies on Heterotic Trends in Blackgram [Vigna mungo (L.) Hepper] for Yield and Earliness

Background: As blackgram cultivation is majorly spread in rain fed areas, breeding short duration and high yielding blackgram varieties is of profound importance to tackle terminal moisture stress and reap impressive yields by breaking the yield plateau. Hence, the present study was aimed to identify highly heterotic cross combinations for yield and earliness. Methods: Six parents along with 15 F1s were evaluated (rabi, 2019) for seed yield and its component traits along with earliness to estimate the magnitude of heterosis. Result: The cross LBG-752 × TBG-104 exhibited heterosis estimates in desirable direction for yield and earliness. The next best crosses were LBG-752 × PU-31, TU-40 × TBG-104, LBG-752 × TU-40 and IPU-2-43 × TBG-104. Because of its autogamous genetic architecture and biological constraints in large scale economic hybrid seed production, heterosis could be exploited only by isolating the early maturing and high yielding segregants followed by bi-parental or recurrent selection in early segregating generations and single plant selection in subsequent generations that would result in short duration and high yielding blackgram variety that fits well into different ecological niches. </jats:p

Improving the energy performances of the refrigeration systems with subcooling using the eco-friendly refrigerant R600A: Initial experimental results

In this paper the attention is focused on introducing the initial experimental results of a comparative experimental investigation on the energy performances of R600a tested as drop-in of R134a in a test-bench refrigeration system developed at the School of Mechanical Engineering of VIT University located in Vellore (India). Moreover, a comparison of the energy performances was pursued also with the system working with and without sub-cooling. The initial experimental investigation is performed respecting the requirement that the two fluids occupy the same volume. The initial energy performances are carried out in terms of evaporator temperature, coefficient of performance and refrigeration effect. The effect of drop-in with R600 a system previously working with R134a, carries an enhancement of the energy performances in terms of COP and refrigeration effect. Moreover, subcooling carries to an additional benefit on the refrigeration effect. The introduced initial experimental results constitute just the first step of a bigger investigation to be conducted in India, focused on analyzing the impact of the drop-in of HFC with new eco-friendly refrigerants

Quantitative Trait Loci (QTL) Detection and Validation of Linked Markers Associated with Yellow Mosaic Virus Resistance in Urdbean [Vigna mungo (L.) Hepper] in Andhra Pradesh

Background: The YMD is one of the serious viral diseases in blackgram and is being transmitted by whitefly (Bemisia tabaci). The development of YMV resistant blackgram varieties is one of the important aspects for sustainable blackgram production. Marker assisted selection and genetic transformation could be utilized in developing YMV resistant blackgram genotypes. Methods: We attempted to map the QTLs governing YMV resistance in blackgram employing parents i.e., PBG32 (susceptible) and PU31 (resistant). Parental polymorphic studies were conducted using 147 SSR markers and genotyping and phenotyping data were used for QTL mapping. The markers, CEDG097 and CEDG172 that flanked to qYMV1 QTL were validated in 25 blackgram genotypes. Result: SSR markers showed 16% polymorphism between the parents. By using F2 genotypic data, genetic linkage map was constructed and total genetic map length observed was 335.47 cm. Single QTL (qYMV1) for YMV tolerance was detected and located between markers CEDG097 and CEDG172 with LOD score value of 2.76. The PVE by qYMV1 is 13.10% and the QTL is tightly linked (0 cM) to the left flanking marker CEDG97, which denotes a major QTL. Genotyping of the 25 known blackgram genotypes employing CEDG097 and CEDG172 markers, CEDG097 showed 91% linkage in known resistant and susceptible varieties to the YMV disease reaction and CEDG172 exhibited 74% linkage in known varieties to the YMV disease reaction. The resistance alleles (PU31 allele) of both markers i.e. CEDG097 and CEDG172 were recorded in VBN7, LBG922, LBG933 and TBG130-1 hence, these genotypes can be considered as potent YMV resistant varieties and also can be used as donor parents in resistance breeding programmes. </jats:p