RESUMEN
Improving the heat tolerance of cotton is a major concern for breeding programs. To address this need, a fast and effect way of quantifying thermotolerant phenotypes is required. Triphenyl tetrazolium chloride (TTC) based enzyme viability testing following high-temperature stress can be used as a vegetative heat tolerance phenotype. This is because when live cells encounter a TTC solution, TTC undergoes a chemical reduction producing a visible, insoluble red product called triphenyl formazan, that can be quantified spectrophotometrically. However, existing TTC based cell viability assays cannot easily be deployed at the scale required in a crop improvement program. In this study, a heat stress assay (HSA) based on the use of TTC enzyme viability testing has been refined and improved for efficiency, reliability, and ease of use through four experiments. Sampling factors that may influence assay results, such as leaf age, plant water status, and short-term cold storage, were also investigated. Experiments conducted in this study have successfully downscaled the assay and identified an optimal sampling regime, enabling measurement of large segregating populations for application in breeding programs. The improved HSA methodology is important as it is proposed that long-term improvements in cotton thermotolerance can be achieved through the concurrent selection of superior phenotypes based on the HSA and yield performance in hot environments. Additionally, a new way of interpreting both heat tolerance and heat resistance was developed, differentiating genotypes that perform well at the time of a heat stress event and those that maintain a similar performance level to a non-stressed control.
RESUMEN
BACKGROUND: The frequency with which patients in Child-Pugh B having hepatocellular carcinoma are treated following the international guidelines according to the Barcelona Clinic Liver Cancer stages is unknown. AIMS: To investigate treatment allocation for Child-Pugh B patients in different tumour stages, with particular interest in the intermediate stage. METHODS: Patients were retrospectively identified from a consecutively collected series. Treatment was carried out primarily according to the guidelines. RESULTS: Of 86 Child-Pugh B patients, 45 were Barcelona early stage, of which the Child-Pugh scores were 46.7% B7, 33.3% B8, 20.0% B9; 27 patients were intermediate stage (B7 59.3%, B8 37.0% and B9 3.7% respectively), 12 were advanced (41.7% B7, 25.0% B8 and 33.3% B9) and 2 were terminal (both B9). In the intermediate stage, transarterial chemoembolization (or ablation) was performed in 68.8% of the Child-Pugh B7 patients, 50% of the B8 patients and 0% of the B9 patients. Median survival of the intermediate patients was 8.0 months (9.0 in B7 vs. 6.0 in -B8/B9, P=0.048). Survival of the intermediate stage patients undergoing chemoembolisation was 22.0 months in Child-Pugh B7 and 6.0 in B8. CONCLUSIONS: Approximately half of the intermediate stage patients can undergo locoregional treatment with good survival when in the Child-Pugh B7. The Child-Pugh numeric score impacts survival, suggesting that this tumour stage be refined.