Dissection of QTLs conferring drought tolerance in B. carinata derived B. juncea introgression lines.

BACKGROUND: Drought is one of the important abiotic stresses that can significantly reduce crop yields. In India, about 24% of Brassica juncea (Indian mustard) cultivation is taken up under rainfed conditions, leading to low yields due to moisture deficit stress. Hence, there is an urgent need to improve the productivity of mustard under drought conditions. In the present study, a set of 87 B. carinata-derived B. juncea introgression lines (ILs) was developed with the goal of creating drought-tolerant genotypes. METHOD: The experiment followed the augmented randomized complete block design with four blocks and three checks. ILs were evaluated for seed yield and its contributing traits under both rainfed and irrigated conditions in three different environments created by manipulating locations and years. To identify novel genes and alleles imparting drought tolerance, Quantitative Trait Loci (QTL) analysis was carried out. Genotyping-by-Sequencing (GBS) approach was used to construct the linkage map. RESULTS: The linkage map consisted of 5,165 SNP markers distributed across 18 chromosomes and spanning a distance of 1,671.87 cM. On average, there was a 3.09 cM gap between adjoining markers. A total of 29 additive QTLs were identified for drought tolerance; among these, 17 (58.6% of total QTLs detected) were contributed by B. carinata (BC 4), suggesting a greater contribution of B. carinata towards improving drought tolerance in the ILs. Out of 17 QTLs, 11 (64.7%) were located on the B genome, indicating more introgression segments on the B genome of B. juncea. Eight QTL hotspots, containing two or more QTLs, governing seed yield contributing traits, water use efficiency, and drought tolerance under moisture deficit stress conditions were identified. Seventeen candidate genes related to biotic and abiotic stresses, viz., SOS2, SOS2 like, NPR1, FAE1-KCS, HOT5, DNAJA1, NIA1, BRI1, RF21, ycf2, WRKY33, PAL, SAMS2, orf147, MAPK3, WRR1 and SUS, were reported in the genomic regions of identified QTLs. CONCLUSIONS: The significance of B. carinata in improving drought tolerance and WUE by introducing genomic segments in Indian mustard is well demonstrated. The findings also provide valuable insights into the genetic basis of drought tolerance in mustard and pave the way for the development of drought-tolerant varieties.

Molecular characterization and genetic diversity analysis in Indian mustard (Brassica juncea L. Czern & Coss.) varieties using SSR markers.

In this study, we evaluated genetic diversity in a panel of 87 Indian mustard varieties using 200 genomic-SSR markers. A total of 189 SSRs resulted into positive amplification with 174 (92.06%) SSRs generating polymorphic products and 15 (7.94%) SSRs producing monomorphic amplicons. A total of 552 alleles were obtained and allele number varied from 2-6 with an average number of 3.17 alleles per SSR marker. The major allele frequency ranged from 0.29 (ENA23) to 0.92 (BrgMS841) with an average value of 0.58 per SSR locus. The polymorphic information content (PIC) value ranged from 0.10 (BrgMS841) to 0.68 (BrgMS519) with 0.39 as mean PIC value. The gene diversity per locus ranged from 0.13 (BrgMS841) to 0.72 (ENA23 & BrgMS519) with a mean value of 0.48 per SSR primer pair. Both Unweighted Neighbor Joining-based dendrogram and population structure analysis divided all the 87 varieties into two major groups/subpopulations. Analysis of molecular variance (AMOVA) inferred the presence of more genetic variation (98%) among individuals than among groups (2%). A total of 31 SSRs produced 36 unique alleles for 27 varieties which will serve as unique DNA-fingerprints for the identification and legal protection of these varieties. Further, the results obtained provided a deeper insight into the genetic structure of Indian mustard varieties in India and will assist in formulating future breeding strategies aimed at Indian mustard genetic improvement.

Should fluorodeoxyglucose positron emission tomography/computed tomography be the first-line imaging investigation for restaging the laryngeal carcinoma patients?

Posttreatment detection of residual/recurrence disease in the head and neck cancers is not an easy task. Treatment induces changes create difficulties in diagnosis on conventional imaging (computed tomography [CT], magnetic resonance imaging) as well as macroscopic inspection (direct laryngoscopy). Hence, we evaluate the diagnostic performance of contract-enhanced F-18 fluorodeoxyglucose positron emission tomography (FDG PET)/CT in restaging of laryngeal carcinoma Postchemotherapy-surgery and/or radiation therapy. We retrospectively analyzed patients of carcinoma larynx (n = 100) who has completed treatment and were referred for FDG PET/CT. Two reviewers performed image analysis to determine recurrence at primary site and/lymph nodes and distant metastases. Receiver operating characteristic (ROC) was used to determine the maximum standardized uptake value (SUVmax) cut off for disease detection. Histopathological examination and clinical or imaging follow-up were taken as gold standard for recurrence. One hundred laryngeal carcinoma patients with mean age of 57.2 years (range of 40-76) were included in the present study. Among the 100 patients, 96 were male and remaining 4 were female. The average interval between completion of treatment and FDG PET/CT scan was 8.5 months (minimum 6 months). Of the 100 patients, FDG PET/CT detected FDG avid lesions in 66 patients. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of FDG PET/CT for residual/recurrence disease detection was 90.3%, 73.7%, 84.8%, 82.3%, and 84.0%, respectively (P < 0.05). In addition, in 10 patients, metachronous primaries were detected (lung-4, thyroid-2, tongue, colon, esophagus, and lymphoma-one each). On ROC curve analysis, SUVmax >6.1 had sensitivity and specificity of 80.6% and 94.7% respectively for detection of recurrent/metastatic disease. FDG PET/CT demonstrates high diagnostic accuracy for detection of residual/recurrent disease in treated laryngeal cancer patients and our findings suggest that this imaging modality should be the first-line diagnostic investigation in this cohort of patients.

Isolated Malignant Portal Vein Thrombus in Colon Carcinoma: A Rare Finding on 18F-FDG PET/CECT.

In the absence of hepatic metastasis in abdominal cancers, an isolated malignant portal vein thrombus is very rare. The presence of a malignant thrombus has clinical significance for determining the stage, treatment, and prognosis. 18F-FDG PET/CECT is a noninvasive modality for discriminating between malignant and benign thrombi. We present a case of primary sigmoid colon carcinoma for which 18F-FDG PET/CT showed, in addition to the 18F-FDG-avid primary lesion, an 18F-FDG-avid filling defect in the portal vein, likely malignant thrombus.

Is F-18 FDG PET/computed tomography a useful tool to restage the patients with tongue carcinoma?

OBJECTIVE: The aim of this study was to evaluate the diagnostic performance of contrast-enhanced F-18 fluoro-2-deoxyglucose (F-18 FDG) PET/computed tomography (CT) in restaging of tongue carcinoma. MATERIAL AND METHODS: Retrospectively analysis of carcinoma tongue patients (n = 110) who were treated and referred for FDG PET/CT. Histopathological examination and clinical or imaging follow-up were taken as gold standard. RESULTS: Of 110 patients, FDG PET/CT detected FDG avid lesions in 69 (62.7%) patients. Sensitivity, specificity and diagnostic accuracy of FDG PET/CT were 92.9%, 90.0% and 91.8%, respectively, for residual/recurrence disease detection (P < 0.05). Additionally, in six patients, metachronous primaries were also detected [lung (4), esophagus and lymphoma (1) each]. The mean maximum standardized uptake value (SUVmax) with 95% confidence interval for primary site recurrence, regional lymph nodes and metastatic lesions was 11.51 (9.53-13.48), 69 (62.7%) (7.88-11.48) and 8.94 (3.11-14.76), respectively. CONCLUSION: FDG PET/CT demonstrates high diagnostic accuracy for detection of residual/recurrent disease in treated tongue cancer patients and PET/CT should be considered as first-line diagnostic investigation in these patients.

Double primary malignancies: a clinical & pathological analysis report from a regional cancer institute in India.

BACKGROUND: Patients which have diagnosed with a cancer, have a life time risk for developing another de novo malignancy depending on various inherited, environmental and iatrogenic risk factors. Cancer victims could survive longer due to settling treatment modalities, and then would likely develop a new metachronous malignancy.This article aims to report our observed trend of increasing, in prevalence of both synchronous and metachronous second primary malignancy, among the cancer victims, and to review the relevant literature. METHODS: A hospital based retrospective gathering of prospective data, among the patients that have diagnosed with second de novo malignancy.The study has conducted over a 4 years period from 2009 to 2012. All patients that have diagnosed with a histologically proven second malignancy as per Warren and Gates criteria have included. Various details which have regarded site, age at presentation, sex, synchronous or metachronous, treatment have recorded. RESULTS: Among 41 cases of multiple primary malignancies that have observed, 8 were synchronous (19.51%) and 33 were metachronous (80.49%). Out of 41 patients, 25 (60.98%) were females and 16 (39.02%) were males. The most common sites of primary tumor were head and neck cancers that have followed by gynecological cancers, breast cancer, lung cancer, esophageal cancer, and then the others. Among the second malignancy, the most common site was breast and gastrointestinal tract that have followed by lung and gynecological cancers. Out of the total number of cases with double location, 14 tumors (34.15%) have belonged to the breast, out of which 5 (12.20%) have represented first locations and 7 (17.07%) have been second locations. Both locations have belonged to the breast in 2 patients (4.9%). In 5 cases (12.20%), there were associations of breast-cervix and in 6 cases (14.63%), there were association of lung-head & neck cancers. CONCLUSION: The incidence of multiple primary malignancies has not been rare at all. Screening procedures have especially been useful for the early detection of associated tumors, whereas careful monitoring of patients has treated for primary cancer, and then a good communication between patients and medical care team would certify not only an early detection for secondary tumors, but only finally & subsequently, an appropriate management.