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The present study aimed to evaluate the morphological, cytogenetic and biochemical changes in wheat seedlings as affected by seed exposure to a proton beam at the Bragg peak. The average energy of the proton beam was of 171 MeV at the entrance into the irradiator room while at the point of sample irradiation the beam energy was of 150 MeV, with the average value of the Linear Energy Transfer of 0.539 keV/µm and the dose rate of 0.55 Gy/min, the radiation doses being of the order of tens of Gy. Cytogenetic investigation has revealed the remarkable diminution of the mitotic index as linear dose-response curve as well as the spectacular linear increase of the aberration index. Analyzing some biometric parameters, it was found that neither dry matter nor water content of wheat seedlings was influenced by proton beam exposure. Studying the biochemical parameters related to the antioxidant defense system, we found that the irradiation caused the slight increasing tendency of peroxidase activity as well as the decreasing trend in the activity of superoxidedismutase in the seedlings grown from the irradiated seeds. The level of malonedialdehyde (MDA) and total polyphenols showed an increasing tendency in all seedling variants corresponding to irradiated seeds, compared to the control. We conclude that the irradiation clearly induced dose-response curves at the level of cytogenetic parameters together with relatively slight variation tendency of some biochemical parameters related to the antioxidant defense system while imperceptible changes could be noticed in the biometric parameters.
RESUMO
BACKGROUND AND AIMS: Bowel ultrasound (BU) is a non-invasive, inexpensive, widely available tool, valuable for inflammatory bowel disease (IBD) assessment. The aim of the present study was to investigate the clinical utility of BU to predict the need to intensify therapy in IBD patients. METHODS: One hundred seventeen IBD patients (89 Crohn's disease, and 28 ulcerative colitis) diagnosis established at least 6 months before enrolment, undergoing maintenance therapy were prospectively included in the study. Bowel ultrasound investigated the following parameters: the bowel wall thickness (BWT), loss of wall stratification, the presence of the bowel wall Doppler signal, the visible lymph nodes, the mucosal hyperechoic spots, and the irregular external bowel wall. The patients were followed-up for 6 months, registering the need to escalate the treatment regimen. Subgroup analyses were conducted for patients requiring immediate treatment intensification (37 subjects), due to active disease at baseline and patients with subsequent treatment intensification, in the 6 months follow-up period (21 cases) in comparison to patients that required no therapeutic optimization (59). RESULTS: During the follow-up, 49.6% of patients needed treatment escalation. All the investigated BU variables were significantly associated with the main outcome. In the multivariate analysis, the mean BWT (p<0.0001), and the presence of the bowel wall Doppler signal (p=0.007) were independent predictors of the main outcome. For the subgroup analyses: mean BWT (p=0.0001) and the presence of the bowel wall Doppler signal (p=0.01) were independent predictors for immediate treatment intensification (active disease at baseline) and mean BWT (p=0.0003) and the lack of bowel wall stratification (p=0.05) were independent predictors for the need of subsequent therapeutic optimization. Logistic regression prediction models and prediction scores (BU score) had the best AUROC values (>0.91) when compared to traditional biomarkers of active inflammation, such as C reactive protein or fecal calprotectin. CONCLUSION: Bowel ultrasound could be used as a non-invasive, easy to use diagnostic tool to predict the need to intensify therapy in patients with IBD.
