Experiences of Multidisciplinary Working: Perspectives from the Wessex Ghana Stroke Partnership.

INTRODUCTION: Substantial gaps remain in our understanding of stroke in Africa as well as in stroke care, practice and policy on the continent. The effective organization of preventative, therapeutic and rehabilitative stroke services continue to be challenging in many African countries. METHODOLOGY: In this article we define the nature, function and benefits of effective multidisciplinary team (MDT) working. The experiences and perspectives of members of the MDT were collated by focus group discussions as well as individual and country specific contributions. RESULTS: The experiences and perspectives of multidisciplinary team members from the United Kingdom and Ghana implementing these practices at the first stroke unit in Korle Bu Teaching Hospital, Accra, with a transparent discussion of successes and challenges faced throughout development of the service, is presented. MDT working has improved outcomes for patients and families who use the services, including encouraging better shared treatment planning and compliance. More stroke rehabilitation services are provided than previously, including greater self-management education and better secondary prevention care. CONCLUSION: It is hoped that this article will provide an inspirational model for others working to provide stroke care in low-resource settings in Africa and worldwide.

INTRODUCTION: Des lacunes substantielles subsistent dans notre compréhension de l'accident vasculaire cérébral en Afrique ainsi que dans les pratiques et politiques sur le continent. L'organisation efficace des services de prévention, de traitement et de réadaptation des AVC reste un défi dans de nombreux pays africains. MÉTHODOLOGIE: Dans cet article, nous définissons la nature, la fonction et les avantages d'une équipe multidisciplinaire efficace (PCT).Les expériences et les points de vue des membres de la PCT ont été recueillis par des discussions de groupes de réflexion ainsi que contributions individuelles et spécifiques à chaque pays. RÉSULTATS: Les expériences et les perspectives des membres d'équipes multidisciplinaires du Royaume-Uni et du Ghana, qui ont mis en œuvre ces pratiques dans la première unité d'AVC du de l'hôpital universitaire Korle Bu, à Accra, avec une discussion transparente des succès et des défis rencontrés tout au long du développement du service, sont présentées. Le travail de la PCT a amélioré les résultats pour les patients et les familles qui utilisent les services, notamment en encourageant un meilleur partage du traitement, l'organisation et la complaisance. Davantage de services de réadaptation après un AVC sont fournis plus qu'auparavant, y compris une meilleure éducation à l'autogestion et de meilleurs soins de prévention secondaire. CONCLUSION: Nous espérons que cet article constituera un modèle inspirant pour d'autres personnes travaillant à la prise en charge d'AVC dans des contextes à faibles ressources en Afrique et dans le monde. Mots clés: Unité de expériences, multidisciplinaire, Ghana, partenariat.

Physicochemical, Microstructural, and Rheological Characterization of Tigernut (Cyperus esculentus) Starch.

The aim of this study was to characterize the physicochemical properties of starch isolated from two varieties of tigernuts. The results showed wide variations between the two types of tigernuts. Mean granule sizes were 11.1 and 6.1 µm, respectively, for starch from the yellow and black while amylose content ranged from 19 to 21%. Starch gels from the yellow variety were more stable to freeze-thaw and recorded 37.1% syneresis, compared to 56.5% after the first storage cycle. Pasting properties were significantly different (p < 0.05) among starch from the two tigernut varieties, with black recording higher peak viscosity, lower breakdown, and higher setback viscosity. Gels made from the yellow variety were clearer, softer, more adhesive, and more cohesive. Both gels showed a pseudoplastic flow behavior without thixotropy.

Renal status of children with sickle cell disease in Accra, Ghana.

INTRODUCTION: In West Africa, the prevalence of sickle cell disease (SCD) is 2%. The disease adversely affects growth, development and organ function including the kidneys. There is however a dearth of information about the renal status of SCD children in Ghana. OBJECTIVES: To assess the renal status of children with SCD in steady state. DESIGN: A cross-sectional case-control study. SETTING: Paediatric Sickle Cell Clinic, Korle Bu Teaching Hospital, Accra. PARTICIPANTS: Cases-357 SCD cases and 70 of their HbAA siblings as controls. METHODS: Documentation of their socio-demographic data, clinical data and dipstick urinalysis findings, and renal ultrasonography on selected participants. RESULTS: The mean [SD] age was 7.18 [3.15]yrs for cases and 5.16[3.28]yrs for controls. The genotypes were Hb SS (76.7%), Hb SC (21.8 %), and Hb Sßthal (1.4%). Urinalysis showed leucocyturia in 12.6% versus 5.7% (χ2=62.5 and the p=0.000)), isolated proteinuria in 2.8% versus 1.43% (χ2=10.01 and p=0.001) haematuria in 2.6% versus 0% (χ2=9.233, p=0.002) and nitrites in 2.2% versus 1.4% (χ2=16.3,p=0.02) of cases and controls respectively. The youngest SCD case with proteinuria was 2 yrs. old. Proteinuria prevalence increased with age, , occurring in 5.7% of cases aged 9-11yrs. and 20.6% of cases aged 12 yrs. Two-thirds of the proteinuria cases were aged 9-12 yrs., of whom 50% were aged 12 yrs. Renal ultrasound findings were normal in all those examined. CONCLUSION: Urinary abnormalities suggesting nephropathy occur early in SCD patients in Ghana. Routine dipstick screening at clinic visits countrywide would help early detection and prompt intervention to limit renal impairment.

Nutritional status of children with sickle cell disease at Korle Bu Teaching Hospital, Accra, Ghana.

BACKGROUND: Sickle cell disease (SCD) with its attendant increased energy requirements has an adverse effect on growth. Good nutrition is essential for normal childhood growth and development. Differences in growth between children living within the same SEC's are likely to be due to the effects of the sickle cell disease. OBJECTIVE: To determine the relationship between SCD and nutritional status in children. METHODS: This cross-sectional study, conducted at the Paediatric Sickle Cell Clinic of the Korle Bu Teaching Hospital, recruited 427 children aged 1-12 years: 357 SCD patients (cases) and 70 of their siblings with Hb AA (controls), over a four-month period. Their socio-demographic data, weight and height/length were documented, and the weight-for-age (WAZ) and height/length-for-age (HAZ), weight-for-height/length (WHZ) scores calculated as indices of nutritional status. RESULTS: The mean (SD) age of SCD participants was 7.18 (3.15) years and of controls was 5.13 (3.28) years, (p=0.8). The prevalence of malnutrition was 61.3% among SCD subjects and 28.6% among controls, (p<0.001). The WAZ (underweight) and HAZ (stunting) scores were significantly more common among SCD children than controls, but the difference in the rates of wasting (WHZ) was not significant (p=0.3). CONCLUSION: Ghanaian SCD children are more underweight and stunted than their Hb AA counterparts living under similar socio-economic conditions. Better education of families about the nutritional needs of SCD children in our community is needed.

Optimized treatment planning for prostate cancer comparing IMPT, VHEET and 15 MV IMXT.

The merits of intensity-modulated very-high energy electron therapy (VHEET) and intensity-modulated proton therapy (IMPT) in relation to intensity-modulated x-ray therapy (IMXT) with respect to the treatment of the prostate have been quantified. Optimized dose distributions were designed for 5-11 beams of 250 MeV VHEET and 15 MV IMXT as well as 1-9 beam ports of IMPT. In the case of the comparison between 250 MeV VHEET and 15 MV IMXT, it was found that the quality of target coverage achievable with VHEET was comparable to or sometimes better than that provided by IMXT. However, VHEET provided an improvement over IMXT in the dose sparing of the sensitive structures and normal tissues. Compared to IMXT, VHEET decreased the mean rectal dose and bladder dose by up to 10% of the prescribed target dose, while reducing by up to 12% of the prescribed target dose the integral dose to normal tissues. In quantifying the merits of IMPT relative to IMXT, it was found that using intensity-modulated proton beams for inverse planning instead of intensity-modulated photon beams improved target dose homogeneity by up to 1.3% of the prescribed target dose, while reducing the mean rectal dose, bladder dose, and normal tissue integral dose by up to 27%, 30% and 28% of the prescribed target dose respectively. The comparison of optimized planning for IMPT and VHEET showed that the quality of target coverage achievable with IMPT is comparable to or better (by up to 1.3% of the prescribed target dose) than that provided by VHEET. Compared to VHEET, IMPT delivered a mean rectal dose and a bladder dose that was lower by up to 17% and 23% of prescribed target dose respectively, and also reduced the integral dose to normal tissues by up to 17% of the prescribed target dose. These results indicate that of the three modalities the greatest dose escalation will be possible with IMPT, then VHEET, and then IMXT. It follows that IMPT will result in the highest probability of complication-free tumour control, while IMXT will provide the lowest probability.

Optimization of intensity-modulated very high energy (50-250 MeV) electron therapy.

This work evaluates the potential of very high energy (50-250 MeV) electron beams for dose conformation and identifies those variables that influence optimized dose distributions for this modality. Intensity-modulated plans for a prostate cancer model were optimized as a function of the importance factors, beam energy and number of energy bins, number of beams, and the beam orientations. A trial-and-error-derived constellation of importance factors for target and sensitive structures to achieve good conformal dose distributions was 500, 50, 10 and I for the target, rectum, bladder and normal tissues respectively. Electron energies greater than 100 MeV were found to be desirable for intensity-modulated very high energy electron therapy (VHEET) of prostate cancer. Plans generated for lower energy beams had relatively poor conformal dose distributions about the target region and delivered high doses to sensitive structures. Fixed angle beam treatments utilizing a large number of fields in the range 9-21 provided acceptable plans. Using more than 21 beams at fixed gantry angles had an insignificant effect on target coverage, but resulted in an increased dose to sensitive structures and an increased normal tissue integral dose. Minor improvements in VHEET plans utilizing a 'small' number (< or =9) of beams may be achieved if, in addition to intensity modulation, energy modulation is implemented using a small number (< or =3) of beam energies separated by 50 to 100 MeV. Rotation therapy provided better target dose homogeneity but unfortunately resulted in increased rectal dose, bladder dose and normal tissue integral dose relative to the 21-field fixed angle treatment plan. Modulation of the beam energy for rotation therapy had no beneficial consequences on the optimized dose distributions. Lastly, selection of beam orientations influenced the optimized treatment plan even when a large number of beams (approximately 15) were employed.

The energy-dependent electron loss model for pencil beam dose kernels.

The 'monoenergetic' electron loss model was derived in a previous work to account for pathlength straggling in the Fermi-Eyges pencil beam problem. In this paper, we extend this model to account for energy-loss straggling and secondary knock-on electron transport in order to adequately predict a depth dose curve. To model energy-loss straggling, we use a weighted superposition of a discrete number of monoenergetic pencil beams with different initial energies where electrons travel along the depth-energy characteristics in the continuous slowing down approximation (CSDA). The energy straggling spectrum at depth determines the weighting assigned to each monoenergetic pencil beam. Supplemented by a simple transport model for the secondary knock-on electrons, the 'energy-dependent' electron loss model predicts both lateral and depth dose distributions from the electron pencil beams in good agreement with Monte Carlo calculations and measurements. The calculation of dose distribution from a pencil beam takes 0.2 s on a Pentium III 500 MHz computer. Being computationally fast, the 'energy-dependent' electron loss model can be used for the calculation of 3D energy deposition kernels in dose optimization schemes without using precalculated or measured data.

Monte Carlo studies of the exit photon spectra and dose to a metal/phosphor portal imaging screen.

The energy spectra and the dose to a Cu plate/Gd2O2S phosphor portal imaging detector were investigated for monoenergetic incident beams of photons (1.25, 2, and 5 MeV). The Monte Carlo method was used to characterize the influence of the patient/detector geometry, detector material and design, and incident beam energy on the spectral distribution and the dose, at the imaging detector plane, of a photon beam scattered from a water phantom. The results show that radiation equilibrium is lost in the air gap and that, for the geometries studied, this effect led to a reduction in the exit dose of up to 40%. The finding that the effects of the air gap and field size are roughly complementary has led to the hypothesis that an equivalent field size concept may be used to account for intensity and spectral changes arising from air gap variations. The copper plate preferentially attenuates the low-energy scattered photons incident on it, while producing additional annihilation, bremsstrahlung, and scattered photons. As a result, the scatter spectra at the copper surface entrance of the detector differs significantly from that at the Cu/phosphor interface. In addition, the mean scattered photon energy at the interface was observed to be roughly 0.4 MeV higher than the corresponding effective energy for 2 MeV incident beams. A comparison of the dose to various detector materials showed that exit dosimetry errors of up to 24% will occur if it is assumed that the Cu plate/Gd2O2S phosphor detector is water equivalent.