Neural distinctiveness and reinstatement of hippocampal representations support unitization for associations.

The medial temporal lobe (MTL) is critical to associative memory success, yet not all types of associations may be processed in a similar manner within MTL subregions. In particular, previous work suggests intra- and inter-item associations not only exhibit differences in overall rates of recollection, but also recruit different MTL subregions. Whereas intra-item associations, akin to unitization, take advantage of associations between within-item features, inter-item associations form links across discrete items. The current work examines the neural differences between these two types of associations using fMRI and multivoxel analyses. Specifically, the current study examines differences across face-occupation as a function of whether the pairing was viewed as a person performing the given job (intra-item binding) or a person saying they knew someone who had a particular job (inter-item binding). The results show that at encoding, successfully recollected neural patterns related to intra- and inter-item associations are distinct from one another in the hippocampus, parahippocampal and perirhinal cortex. Additionally, the two trial types are reinstated distinctly such that inter-item trials have higher neural reinstatement from encoding to retrieval compared to intra-item trials in the hippocampus. We conclude that intra- and inter- associative pairs may utilize similar neural regions that represent patterns of activation differentially at encoding. However, to reinstate information to the same degree (i.e., subsequently successfully recollected) inter-item associations, that are all encoded in the same manner, may be reinstated more similarly compared to intra-item associations that are encoded by imagining pairs differently and occupation specific. This may indicate that intra-item associations promote more efficient reinstatement.

All-cause and cause-specific mortality following non-traumatic spinal cord injury: evidence from a population-based cohort study in Switzerland.

STUDY DESIGN: Observational cohort study. OBJECTIVE: To benchmark all-cause and cause-specific mortality following NTSCI to the general population (GP). SETTING: Specialized rehabilitation centers in Switzerland. METHODS: Longitudinal data from the Swiss Spinal Cord Injury (SwiSCI) Medical Record study were probabilistically linked with cause of death (CoD) information from the Swiss National Cohort. Standardized mortality ratios (SMRs) were estimated for all-cause and cause-specific mortality. Competing risk frameworks were used to estimate the probability of death due to specific CoD. RESULTS: One thousand five hundred and one individuals were admitted for first rehabilitation with NTSCI between 1990-2011; CoD information was available for 454 individuals of the 525 individuals that died. Overall, the mortality rate for persons with NTSCI was 1.6 times greater than that of the GP. Deaths due to cardiovascular disease (39.8%), neoplasms (22%), and infection (9.9%) were most often reported. Individuals with an SCI due to a vascular etiology indicated the greatest burden of mortality from infection compared with the GP (SMR 5.4; 95% CI, 3.1 to 9.2). CONCLUSIONS: Cause-specific SMRs varied according to etiology. This supports the need for targeted clinical care and follow-up. Cardiovascular disease, neoplasms, and infection, emerged as main causes of death following NTSCI and should thus be targets for future research and differential clinical management approaches.

Survival after non-traumatic spinal cord injury: evidence from a population-based rehabilitation cohort in Switzerland.

STUDY DESIGN: Observational cohort study. OBJECTIVE: To investigate survival and life expectancy after NTSCI in Switzerland according to etiology. SETTING: Specialized rehabilitation centers in Switzerland. METHODS: Longitudinal data from the Swiss Spinal Cord Injury (SwiSCI) medical records study were used. Adjusted hazard ratios (HRs) and life expectancies were estimated using flexible parametric survival modeling. RESULTS: One thousand four hundred and fifty individuals were admitted to first rehabilitation for NTSCI between 1990 and 2011, contributing 6137 cumulative person-years at risk and 528 deaths. With reference to persons with a degenerative disc disorder, the HR for mortality in individuals with NTSCIs from infections was 1.42 (95% CI 0.99-2.04), while risk in those with NTSCIs from vascular disorders was 1.28 (95% CI 0.97-1.68). Mortality risk was most pronounced in individuals with NTSCIs from malignant neoplasms (HR 6.32, 95% CI 4.79-8.34). Exemplified for males with an attained age of 60 years, a malignant etiology was associated with 1.7 life years remaining (LYR), as compared to 10.1 LYR for non-malignant etiologies. Males with an attained age of 60 years and a degenerative disc etiology were estimated to have 12.9 LYR. CONCLUSIONS: This study contributes an evidence base for risk factors of mortality after NTSCI, reducing a considerable knowledge gap in survival after NTSCI. Survival and life expectancy estimates were highly differential between etiological groups, indicating a need for a heterogeneous clinical approach and dynamic health-care provisions for this growing population.

Prospective audit of treatment of paediatric febrile neutropenia in Australasia.

OBJECTIVES: Febrile neutropenia post-chemotherapy continues to impose a burden of morbidity and mortality on patients and families affected by childhood cancer, whereas these unplanned hospital admissions increase the financial cost of treating paediatric malignancies. There are currently no published national guidelines. This study comprises the first audit of current therapeutic practice in Australasia. METHODS: Information was sought prospectively from the 12 paediatric oncology tertiary referral centres in Australia and New Zealand regarding treatment of febrile neutropenia episodes commencing between 11 March and 10 May 2002. RESULTS: Data were returned on 127 episodes by nine centres. The median length of stay was 6 days and 18 different antibiotic regimens were implemented as first-line therapy. The median neutrophil count at the beginning and end of the febrile neutropenic episode was 0.0 x 10(9)/L (range 0.0 to 2.3 x 10(9)/L) and 0.7 x 10(9)/L (range 0.0 to 25.4 x 10(9)/L), respectively. Thirty per cent of episodes had positive blood cultures. Of these, 81% occurred in patients with tunnelled central venous catheters. The initial antimicrobial combination was changed in 61% of episodes. Outpatient antibiotics were used in 21% episodes after initial intravenous antimicrobial therapy. CONCLUSIONS: The current practice in Australasia is consistent with international guidelines, although changes are made more frequently to first-line therapy than in previous published studies. The central venous catheters are associated with a much higher risk of bacteraemia and consideration should be given to increased use of implanted port systems.

A 17-year epidemiological study on changes in lung function in toluene diisocyanate foam workers.

OBJECTIVE: To determine whether longitudinal declines in ventilatory capacity and the occurrence of respiratory symptoms in workers manufacturing polyurethane foam were related to toluene diisocyanate (TDI) exposure. METHODS: A population of workers from 12 UK factories was studied between 1981 and 1986 [8]. A survivor cohort of 251, of whom 217 were in the 1981-1986 study, was examined again in 1997-1998. Modified British Medical Research Council respiratory questionnaires and lung function measurements were completed for each of the 251 subjects at the beginning and end of the 17-year study period. Mean TDI exposures for all jobs in which subjects were employed were assessed and related to their occupational histories. RESULTS: The annual declines in 1-second forced expiratory volume (FEV(1)) and forced vital capacity (FVC) were not related to TDI exposure, and were typical of those measured in other populations not exposed to TDI. Over the study period the cold-foam handling group ( n=26) showed an increase in breathlessness and a significant excess decline in FVC; the exposed group ( n=175) showed an increase in wheezing (mainly smokers), whilst the low-exposure group ( n=50) showed a decrease in chest illness. Smoking and an increase in body weight both caused excess declines in FEV(1). CONCLUSIONS: This study does not provide evidence that there was any TDI-related decline in FEV(1) or in FVC over a 17-year period in workers exposed to TDI at the levels prevailing in the UK factories that manufactured flexible polyurethane foam.

An epidemiology study of lung function changes of toluene diisocyanate foam workers in the United Kingdom.

OBJECTIVE: To determine whether longitudinal declines in ventilatory capacity and the occurrence of respiratory symptoms in workers manufacturing polyurethane foam were related to toluene diisocyanate (TDI) exposure. METHODS: A population of 780 workers in 12 United Kingdom factories was followed for 5 years. Modified United Kingdom Medical Research Council (MRC) respiratory questionnaires and three or more lung function measurements were completed for each subject. Mean TDI exposures for all jobs in which subjects were employed were assessed by personal monitoring (2294 measurements) and related to their occupational histories. RESULTS: The United Kingdom 8-h and 15-min maximum exposure limits for TDI were exceeded in 4.7% and 19.0% of the samples taken, respectively. There was some increase in reported respiratory symptoms amongst exposed workers, but the annual declines of 1-s forced expiratory volume (FEV1) and forced vital capacity (FVC) were not related to TDI exposure and were typical of those observed in other longitudinal populations. FEV1 declines were smoking-related. Evidence was found suggesting that a small excess decline in FEV1 and FVC occurred in the first few years of employment for workers not previously exposed to TDI. CONCLUSION: This study does not provide evidence that there is a TDI-related decline in FEV1 and FVC in workers exposed to less than the United Kingdom 8-h occupational exposure limit of 5.8 ppb.