312 research outputs found

    The outcome at 12 months of very-Iow-birth-weight infants ventilated at Tygerberg Hospital

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    Objective. To determine the outcome at 1 year of age of a group of very-Iow-birth-weight (VLBW) infants, from urban and rural communities, ventilated at Tygerberg Hospital, W. Cape. Study design. Prospective descriptive study in which the prevalence of bronchopulmonary dysplasia (BPD), sensorineural deafness, intraventricular haemorrhage (IVH), retinopathy of prematurity (ROP) and abnormal motor developmental outcomes were determined in 153 ventilated VLBW infants from rural and urban areas. Of these, 69% were from lower socio-economic backgrounds. Main outcome measures. Attrition rates for rural and urban babies, BPD, ROP, IVH and abnormal motor development. Study population and setting. All ventilated VLBW infants discharged from the neonatal intensive care unit at Tygerberg Hospital over a 1-year period were followed up at 3-monthly intervals for 12 months. Results. BPD was diagnosed in 19% of the babies, with significantly more babies with birth weights under 1 000 g and gestational ages under 28 weeks having BPD. Of the babies with BPD, 25% had abnormal motor development at 1 year of age. Seven per cent of the babies had grade 3 or 4 ROP and 2,6% had sensorineural hearing loss. One hundred and seventeen (79%) of the infants attended the follow-up clinic until 12 months of age (corrected for prematurity). There were no significant differences in the number of babies followed up from rural or urban areas. Fourteen (11,9%) of the babies had abnormal motor development. A disturbing finding was that so many babies had spastic qiJadriplegia (8; 57%) versus diplegia (6; 43%).S Afr Med J 1995; 8

    Current approaches to management of bone sarcoma in adolescent and young adult patients

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    Bone tumors are a group of histologically diverse diseases that occur across all ages. Two of the commonest, osteosarcoma (OS) and Ewing sarcoma (ES), are regarded as characteristic adolescent and young adult (AYA) cancers with an incidence peak in AYAs. They are curable for some but associated with unacceptably high rates of treatment failure and morbidity. The introduction of effective new therapeutics for bone sarcomas is slow, and to date, complex biology has been insufficiently characterized to allow more rapid therapeutic exploitation. This review focuses on current standards of care, recent advances that have or may soon change that standard of care and challenges to the expert clinical research community that we suggest must be met

    Selective tuning of high-Q silicon photonic crystal nanocavities via laser-assisted local oxidation

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    We examine the cavity resonance tuning of high-Q silicon photonic crystal heterostructures by localized laser-assisted thermal oxidation using a 532 nm continuous wave laser focused to a 2.5 mm radius spot-size. The total shift is consistent with the parabolic rate law. A tuning range of up to 8.7 nm is achieved with ~ 30 mW laser powers. Over this tuning range, the cavity Q decreases from 3.2\times10^5 to 1.2\times10^5. Numerical simulations model the temperature distributions in the silicon photonic crystal membrane and the cavity resonance shift from oxidation.Comment: 12 pages, 7 figure

    Respiratory-gated (4D) contrast-enhanced FDG PET-CT for radiotherapy planning of lower oesophageal carcinoma: Feasibility and impact on planning target volume

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    Background: To assess the feasibility and potential impact on target delineation of respiratory-gated (4D) contrast-enhanced 18 Fluorine fluorodeoxyglucose (FDG) positron emission tomography - computed tomography (PET-CT), in the treatment planning position, for a prospective cohort of patients with lower third oesophageal cancer. Methods: Fifteen patients were recruited into the study. Imaging included 4D PET-CT, 3D PET-CT, endoscopic ultrasound and planning 4D CT. Target volume delineation was performed on 4D CT, 4D CT with co-registered 3D PET and 4D PET-CT. Planning target volumes (PTV) generated with 4D CT (PTV 4DCT), 4D CT co-registered with 3D PET-CT (PTV 3DPET4DCT) and 4D PET-CT (PTV 4DPETCT ) were compared with multiple positional metrics. Results: Mean PTV 4DCT , PTV 3DPET4DCT and PTV 4DPETCT were 582.4 ± 275.1 cm 3 , 472.5 ± 193.1 cm 3 and 480.6 ± 236.9 cm 3 respectively (no significant difference). Median DICE similarity coefficients comparing PTV 4DCT with PTV 3DPET4DCT, PTV 4DCT with PTV 4DPETCT and PTV 3DPET4DCT with PTV 4DPETCT were 0.85 (range 0.65-0.9), 0.85 (range 0.69-0.9) and 0.88 (range 0.79-0.9) respectively. The median sensitivity index for overlap comparing PTV 4DCT with PTV 3DPET4DCT, PTV 4DCT with PTV 4DPETCT and PTV 3DPET4DCT with PTV 4DPETCT were 0.78 (range 0.65-0.9), 0.79 (range 0.65-0.9) and 0.89 (range 0.68-0.94) respectively. Conclusions: Planning 4D PET-CT is feasible with careful patient selection. PTV generated using 4D CT, 3D PET-CT and 4D PET-CT were of similar volume, however, overlap analysis demonstrated that approximately 20% of PTV 3DPETCT and PTV 4DPETCT are not included in PTV 4DCT , leading to under-coverage of target volume and a potential geometric miss. Additionally, differences between PTV 3DPET4DCT and PTV 4DPETCT suggest a potential benefit for 4D PET-CT. Trial registration: ClinicalTrials.gov Identifier - NCT02285660(Registered 21/10/2014)
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