We have investigated the diversity of serine esterases in pollen and stigma tissues of Brassica napus and the role of these enzymes in pollen germination and pollen tube penetration of the stigma. The serine esterase-specific inhibitor diisopropyl fluorophosphate was used as a probe in a tritiated form, [ 3 H]-DIPF, to determine the number and diversity of serine esterases in crude protein extracts from pollen and stigma. Seven serine esterases were identified in pollen and at least seven serine esterases were identified in stigma. The most abundant enzymes had molecular weights of 30-50 kDa. In the pollen extract a serine esterase was detected with the same molecular weight, 22 kDa, as an esterase previously shown to be a cutinase. Only one serine esterase (40 kDa) appeared to be shared between pollen and stigma extracts. Butyrate esterase activity in pollen and stigma extracts was assayed using p-nitrophenyl butyrate (PNB), an ester substrate frequently used in 'cutinase' assays. Total PNBase activity in pollen and stigma extracts was shown to be significantly reduced by the serine esterase inhibitors DIPF and ebelactone B. When DIPF and ebelactone B were applied to stigmas prior to pollination, pollen germination was not significantly affected but, at the highest inhibitor concentrations, up to 70% of germinating pollen tubes failed to penetrate the stigma surface. These data demonstrate that serine esterases, most probably cutinase(s), are required for pollen tube penetration of the dry cuticularised Brassica stigma.

IntroductionAssault is the third most common cause of traumatic brain injury (TBI), after falls and road traffic collisions. TBI can lead to multiple long-term physical, cognitive and emotional sequelae, including post-traumatic stress disorder (PTSD). Intentional violence may further compound the psychological trauma of the event, in a way that conventional outcome measures, like the Glasgow Outcome Scale (GOS), fail to capture. This study aims to examine the influence of assault on self-reported outcomes, including quality of life and symptoms of PTSD.MethodsQuestionnaire were completed by 256 patients attending a TBI clinic, including Quality of Life after Brain Injury (QOLIBRI) and PTSD checklist (PCL-C). Medical records provided demographics, clinical data and aetiology of injury. Subjective outcomes were compared between assault and other causes.ResultsOf 202 patients analysed, 21% sustained TBI from assault. There was no difference in severity of injuries between assault and non-assault groups. No relationship was found between self-reported outcomes and TBI severity or GOS. The assault group scored worse in all self-reported questionnaires, with statistically significant differences for measures of PTSD and post-concussion symptoms. However, using threshold scores, the prevalence of PTSD in assaulted patients was not higher than non-assault. After adjusting for age, ethnicity and the presence of extra-cranial trauma, assault did not have a significant effect on questionnaire scores. Exploratory analysis showed that assault and road traffic accidents were associated with significantly worse outcomes compared to falls.ConclusionQuality of life is significantly related to functional and psychological outcomes after TBI. Assaulted patients suffer from worse self-reported outcomes than other patients, but these differences were insignificant when adjusted for demographic factors. Intentionality behind the traumatic event is likely more important than cause alone. Differences in quality of life and other self-reported outcomes are not reflected by the Glasgow Outcome Scale. This information is useful in arranging earlier and targeted review and support.

No abstract