2,214 research outputs found

    The diagnosis and medical management of tuberculous meningitis in adults

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    Tuberculous meningitis (TBM) is a medical emergency for which tuberculosis (TB) treatment should be initiated as soon as possible after diagnosis. Owing to the low diagnostic yields of confirmatory tests, TBM is often diagnosed based on suggestive clinical and cerebrospinal fluid findings, evidence for TB outside the central nervous system (CNS), typical brain imaging features and exclusion of other causes of meningitis. TB drug regimens used in TBM may be suboptimal as they are informed by studies of TB outside the CNS, rather than being based on randomised controlled trials in TBM. TBM has a high mortality and the management of HIV-co-infected patients is further complicated by neurological TB-immune reconstitution inflammatory syndrome (IRIS), which frequently occurs after starting antiretroviral therapy (ART) during TBM treatment and contributes to the poor outcome in HIV-associated TBM. HIV-infected TBM patients due to start ART should be counselled about the risk of developing neurological TB-IRIS, typical symptoms that could be expected and need to return to hospital should any of these develop. Currently, the only evidence-based treatment for TB-IRIS is with corticosteroids, which should be considered in all cases of neurological TB-IRIS

    A new model for the simplification of particle counting data

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    This paper proposes a three-parameter mathematical model to describe the particle size distribution in a water sample. The proposed model offers some conceptual advantages over two other models reported on previously, and also provides a better fit to the particle counting data obtained from 321 water samples taken over three years at a large South African drinking water supplier. Using the data from raw water samples taken from a moderately turbid, large surface impoundment, as well as samples from the same water after treatment, typical ranges of the model parameters are presented for both raw and treated water. Once calibrated, the model allows the calculation and comparison of total particle number and volumes over any randomly selected size interval of interest

    In Search of an Alternative to Fire for Manipulating Bush Encroachment in the Arid Karoo Region of South Africa

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    Burning of natural rangeland in order to rejuvenate and increase palatability of grazing is a common practice in parts of South Africa. Concern about the long-term effects on biodiversity and the depletion of much-needed soil car-bon led to this investigation

    Effect of Juice Turbidity and Yeast Lees Content on Brandy Base Wine and Unmatured Pot-still Brandy Quality

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    The aims of this project were to identify a suitable grape juice clarification technique for the attainment of the optimal brandy base wine turbidity, to determine the importance of chemical components (volatile components and long-chain fatty acids) in brandy base wine and unmatured pot-still brandy quality, and to study the effect of yeast lees content on quality. Although common industry practice is to use the grape cultivars Colombar(d) and Chenin blanc for the production of brandy base wine, the optimal conditions for Chenin blanc have been defined in this study. The juice clarification treatments applied included no settling, cold settling, whisk, large- and small-scale centrifugation and bentonite. Yeast strain 228 was compared with VIN13, large-scale (L) distillation was compared with small-scale (s) distillation, and the use of no enzyme was compared with the use of pectolytic enzyme. The data for four vintages were compiled and evaluated. Settling with or without pectolytic enzyme, bentonite, small-scale centrifugation and whisk treatments gave clearer Chenin blanc juice, higher concentrations of certain volatile components and long-chain fatty acids, and higher quality brandy base wine and unmatured pot-still brandy. No settling and large-scale centrifugation yielded the most turbid and lowest quality products. There is a definite relationship between treatments, turbidity, concentrations of esters, higher alcohols and acids, and overall brandy base wine and unmatured pot-still brandy quality. The use of yeast strain VIN13 (as opposed to strain 228), in conjunction with an increased yeast lees content of 1.5x that is normally found in brandy base wine, yielded the best quality unmatured pot-still brandy. Based on the results of this study, it is possible to recommend the best juice clarification method(s) for optimal turbidity as well as optimal levels of yeast lees addition, and to identify chemical compounds that positively relate to quality

    Factors affecting the reproducibility of fermentation of grape juice and of the aroma composition of wines 1. Grape maturity, sugar, inoculum concentration, aeration, juice turbidity and ergosterol

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    Gas chromatographic analysis was used for the investigation of some factors which determine the production of volatile wine components during fermentation. Especially the effect of "heterogenous" juice factors such as turbidity and air content were investigated in respect of fermentation rate and the production of fatty acids, fusel alcohols and esters. lt was shown that the fermentation lag of clear filtered and de-aerated grape juices could be prevented by small ergosterol additions before inoculation. A marked similarity was observed in the chromatograms of wines from fermentations of clear juices which were stimulated either by air or by ergosterol. Grape maturity proved to be a major factor affecting the production of volatile acids, alcohols and esters during fermentation. Fermentations of de-aerated and clear filtered juice with an addition of 0.5 g bentonite/l yielded wines with the best scores an sensory evaluation.Maßgebliche Faktoren fĂŒr die Reproduzierbarkeit der VergĂ€rung von Traubenmostund die Aromazusammensetzung von WeinI. Traubenreife, Zucker, Konzentration des lnokulums, Luft, Klarheit des Mostesund ErgosterinEinige Faktoren, welche die Bildung flĂŒchtiger Weininhaltsstoffe bei der GĂ€rung beeinflussen, wurden gaschromatographisch untersucht. Besonders die Wirkung „heterogener" Faktoren im Traubenmost, wie zum Beispiel TrĂŒbung und Luftgehalt, auf die GĂ€rungsgeschwindigkeit und die Bildung von FettsĂ€uren, Fuselalkoholen und Estern wurde untersucht. Es wurde gezeigt, daß die GĂ€rungsverzögerung bei klarfiltrierten und entlĂŒfteten TraubensĂ€ften durch die ZufĂŒgung kleiner Mengen von Ergosterin vor der Inokulation verhindert werden kann. Wurde die GĂ€rung von geklĂ€rtem Most durch Luft oder durch Ergosterin angeregt, so zeigten die Chromatogramme der Weine eine starke Ähnlichkeit. Die Traubenreife erwies sich als der wichtigste Faktor, der die Bildung von flĂŒchtigen SĂ€uren, Alkoholen und Estern bei der GĂ€rung beeinflußt. Die VergĂ€rung von entlĂŒftetem und klarfiltriertem Most mit Zusatz von 0,5 g Bentonit/l ergab Weine, die bei der Weinprobe die höchsten Punktezahlen erhielten

    Dysbetalipoproteinaemia-clinical and pathophysiological features

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    Objectives. Dysbetalipoproteinaemia (type III hyperlipidaemia, broad-beta disease) is a highly atherogenic genetic disorder of lipoprotein metabolism. It presents with a severe mixed hyperlipidaemia in which the ratio of total cholesterol to triglycerides is typically 2:1. There is a high incidence of atherosclerotic complications and severe hypertriglyceridaemia may cause pancreatitis. Highly effective therapy is available and affected families also benefit from genetic counselling.We present a review of our experience with dysbetalipoproteinaemia at the lipid clinic of Groote Schuur Hospital to enhance awareness of this serious condition, for which the index of suspicion should be raised.Design. Retrospective review of case records, 1969- 2001.Setting. Lipid clinic of Groote Schuur Hospital, Cape Town.Subjects. Patients with dysbetalipoproteinaemia diagnosed by the presence of cholesterol-enriched very-low-density lipoproteins (VLDL) and/or dyslipidaemia associated with homozygosity for apolipoprotein E2 or carriers of the apoE2 (Arg 145 →Cys) mutation.Results. One hundred and five patients were identified, 55 of whom were male and 50 female. The age at presentation was 48.8 ± 11.1 years (mean, standard deviation). Total cholesterol was 12.0 ± 5.5 mmol/l and plasma triglycerides 8.3 ± 9.8 mmol/1. The ratio (by mass) of cholesterol to triglycerides within VLDL was 0.52 ± 0.17, while VLDL cholesterol to plasma triglycerides was 0.33 ± 0.09. Fifty patients were E2 homozygotes while 22 carried the apoE2(Arg→ 145 Cys) mutation. Palmar crease xanthomas occurred in 20% of patients, cutaneous xanthomas in 18%, and tendon xanthomas in 13%. Coronary artery disease was found in 47% of patients and peripheral vascular disease in 20%. Fibrates were the most commonly used hypolipidaemic agents (48%), while 31% of patients received combination therapy with a fibrate and statin. Statin monotherapy was used in 11% of patients and a few patients were treated with niacin or required no drug therapy. The treated cholesterol was 5.7 ± 2.4 mmol/1, with plasma triglycerides of 2.7 ± 1.9 mmol/1. Conclusions. Dysbetalipoproteinaemia is a highly atherogenic disorder and is extremely responsive to therapy. A significant proportion of dysbetalipoproteinaemia locally is caused by the apoE2(Arg→ 145 Cys) mutation and is therefore dominantly inherited. This mutation is particularly prevalent in the black community where dysbetalipoproteinaemia may be undiagnosed in many patients. Patients with severe mixed hyperlipidaemia or clinical stigmata of dyslipidaemia should be assessed at a lipid clinic for a specific diagnosis and initiation of therapy.

    Classification of White Cultivar Wines by Origin using Volatile Aroma Components

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    Stepwise discriminant analysis was applied to gas chromatographic data of some volatile compounds obtmiieabjiTreonextracliOii"of dry white table wines. By means of this statistical method, successful classifications according to origin of Colombar wines from two regions, and Chenin blanc wines from three regions, were obtained. The components with the highest discriminatory value were i-amyl acetate, hexyl acetate and i-butanol, in the case of the Colombar wines and hexanol and 2-phenyl ethanol in the case of the Chenin blanc wines

    Objective quality rating of Pinotage wine

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    Relationships between wine composition and three quality parameters were investigated employing a linear multiple regression statistical model. For this purpose a least squares curve fitting computer programme was applied to analyses of 17 Pinotage wines for 6 fatty add esters. Overall quality, taste and aroma ratings were determined by a taste panel and utilized as dependent variables. lt was found that 2 esters viz. n-hexylacetate and ethyl-n-octanoate allowed excellent prediction equations to be set up for the quality ratings when incorporated into multiple regression equations.Objektive Beurteilung der WeinqualitĂ€t bei der Sorte PinotageDie Beziehungen zwischen der Weinzusammensetzung und drei Parametern der WeinqualitĂ€t wurden untersucht, wobei das statistische Modell einer mehrfachen linearen Regression verwendet wurde. Zu diesem Zweck wurden die bei 17 Weinen der Sorte Pinotage gewonnenen Analysenergebnisse ĂŒber 6 FettsĂ€ureester in ein Computerprogramm zur optimalen Kurvenanpassung eingegeben. Durch ein Gutachtergremium wurden die Gesamt-WeinqualitĂ€t, der Geschmack und der Geruch bewertet; die Daten dieser QualitĂ€tsbeurteilung wurden als abhĂ€ngige VerĂ€nderliche benĂŒtzt. Es wurde festgestellt, daß 2 Ester, nĂ€mlich n-Hexylacetat und Äthyl-n-octanoat eine ausgezeichnete Vorhersage der WeinqualitĂ€t ermöglichten, wenn ihre Werte in Mehrfachregressions-Gleichungen eingesetzt wurden
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