Analysis of chromameter results obtained from corticosteroid-induced skin blanching. I. Manipulation of data
- Authors: Smith, Eric W , Haigh, John M , Walker, Roderick B
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6424 , http://hdl.handle.net/10962/d1006559
- Description: Purpose. One of the unresolved issues in the FDA Guidance document for topical corticosteroid bioequivalence testing is the method of manipulation suggested for the chromameter data. The purpose of this study was to manipulate the instrumental data from a typical blanching study in a number of ways to investigate the appropriateness of these procedures for comparison with the subjective visually-assessed results. Methods. The human skin blanching assay methodology routinely practiced in our laboratories was utilised and the vasoconstriction produced by two corticosteroid formulations of different potency was assessed visually and instrumentally by use of a Minolta chromameter. The instrumental data were corrected for zero-time and unmedicated site readings. In addition, Euclidean distances were calculated using all data generated by the instrument. Results. Individually the a-, b- and L-scale chromameter values are imprecise and there is negligible vasoconstriction response recorded for the moderately potent formulation. Arithmetical manipulation of the data as suggested by the FDA does not appear to improve the quality of the data in any way. Euclidean distance analysis more closely resembles the visual data and appears to have better precision. Conclusions. It is clear that mathematical correction of chromameter data is unnecessary, especially since the instrumental data are extremely imprecise. Furthermore, the assessment of each individual chromameter index does not adequately characterise the blanching response profile. It is therefore suggested that Euclidean distance may be a better measure on which to base an analysis of bioequivalence than the truncated data set methodology currently suggested by the FDA.
- Full Text: false
- Date Issued: 1998
Analysis of macrolide antibiotics
- Authors: Kanfer, Isadore , Skinner, Michael F , Walker, Roderick B
- Date: 1998
- Language: English
- Type: Article , text
- Identifier: vital:7011 , http://hdl.handle.net/10962/d1008394 , http://www.sciencedirect.com/science/article/pii/S0021967398002763
- Description: The following macrolide antibiotics have been covered in this review: erythromycin and its related substances, azithromycin, clarithromycin, dirithromycin, roxithromycin, flurithromycin, josamycin, rokitamycin, kitasamycin, mycinamycin, mirosamycin, oleandomycin, rosaramicin, spiramycin and tylosin. The application of various thin-layer chromatography, paper chromatography, gas chromatography, high-performance liquid chromatography and capillary zone electrophoresis procedures for their analysis are described. These techniques have been applied to the separation and quantitative analysis of the macrolides in fermentation media, purity assessment of raw materials, assay of pharmaceutical dosage forms and the measurement of clinically useful macrolide antibiotics in biological samples such as blood, plasma, serum, urine and tissues. Data relating to the chromatographic behaviour of some macrolide antibiotics as well as the various detection methods used, such as bioautography, UV spectrophotometry, fluorometry, electrochemical detection, chemiluminescence and mass spectrometry techniques are also included.
- Full Text:
- Date Issued: 1998
Can shed snakeskin be considered to be a model membrane for human stratum corneum?
- Authors: Haigh, John M , Beyssac, E , Aiache, J M
- Date: 1998
- Language: English
- Type: Article
- Identifier: vital:6383 , http://hdl.handle.net/10962/d1006303
- Description: Recently there has been some interest in the use of shed snake skin as a "model" membrane for in vitro diffusion studies. Many different species of snake have been utilised as well as different skin sites (dorsal and ventral). The species is usually named and sometimes the skin site is indicated butsometimes neither species nor skin site is reported. Insome countries it is particularly difficult to obtain human skin for in vitro experimentation and it is therefore important to have alternate biological or synthetic membranes which mimic human skin membranes for diffusion experiments. In South Africa. shed snake skin is easily obtainable from the many snake parks present in the country. Since snakes moult periodically, a single animal can provide repeated sheds, thus reducing interindividual variability. Skins can be obtained without injury to the animal and do not have to be subjected to chemical or heat stress prior to use. The epidermis is shed as a large intact sheet, thus a single snake skin can provide multiple samples. Shed snake skin is not a living tissue, can be stored for long periods at room temperature and is easily transported. Stored and fresh snake skins appear to show no differences in permeability. Since snake skin lacks hair follicles,the problems associated with the transfollicular route of penetration, which may be significant in mammalian skins, can be avoided.
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- Date Issued: 1998
Computer modelling of ore body formation by a multi-disciplinary approach : some initial results
- Authors: Rice, A
- Date: 1988
- Language: English
- Type: Article
- Identifier: vital:6741 , http://hdl.handle.net/10962/d1007557
- Description: Reports on the initial efforts of a computational programme at Rhodes University in Cape Province, South Africa to model the formation of mineral deposits in the country. Initial results pertaining to the cooling of buried bodies of molten rock; Contribution to a better margin of success for South African mineral industries.
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- Date Issued: 1988
Diet of two Antarctic dragonfish (Pisces: Bathydraconidae) from the Indian sector of the Southern Ocean
- Authors: Pakhomov, Evgeny A
- Date: 1998
- Subjects: Antarctica Bathydraconidae
- Language: English
- Type: Article
- Identifier: vital:6943 , http://hdl.handle.net/10962/d1011970 , http://dx.doi.org/10.1017/S095410209800008X
- Description: The diet of Cygnodraco mawsoni Waite 1916 and Gymnodraco acuticeps Boulenger 1902 (Pisces: Bathydraconidae) was studied in the Cooperation and Cosmonaut seas in the depth range 200–400 m during the summer 1988. Stomach content analysis showed that both species are piscivorous predators but with different feeding habits. Cygnodraco mawsoni fed mostly on young notothenioid fish, regularly complementing these with pelagic, Euphausia superba, and benthic crustaceans, such as amphipod gammarids and mysids. In contrast, G. acuticeps relied mostly on mesopelagic fish of the family Myctophidae. Although C. mawsoni and G. acuticeps occupy similar depths in the Cosmonaut Sea, different feeding habits appear to limit the probability of interspecific competition for food.
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- Date Issued: 1998
Disabling myth or writing for the world: the secondary schools language project in the Eastern Province, South Africa
- Authors: Bleach, Jean
- Date: 1998
- Language: English
- Type: Article
- Identifier: vital:7016 , http://hdl.handle.net/10962/d1007170
- Description: The majority of learners in South African schools are black, and they learn through English as a second language (L2). This contrasts with white students who learn through their first language (L1), English or Afrikaans. Most black students in South Africa are multilingual, and new developments in the curriculum promise to value this achievement. Even now, young black students display considerable competence in their written English when they use electronic links to communicate with fellow students and adults worldwide. Computers motivate students as writers and language learners. One of the many disabling myths that threatens to impede progress towards equity in educational outcomes in South Africa is the myth that teachers of writing in historically black schools will wait a very long time for the technologies of word processing and e-mail to be available to them. In the Eastern Province many schools have no telephones or electricity. The ANC Government is struggling to meet basic needs quickly and computers could then be used to promote equity among learners. In this study, students had only limited access to keyboard and e-mail facilities, yet the enthusiasm and concentration computers generated meant that they could leapfrog many hours of classroom instruction.
- Full Text:
- Date Issued: 1998
Eva's men : gender and power in the establishment of the Cape of Good Hope, 1652–74
- Authors: Wells, Julia C
- Date: 1998
- Language: English
- Type: Article
- Identifier: vital:6148 , http://hdl.handle.net/10962/d1006811 , http://dx.doi.org/10.1017/S0021853798007300
- Description: This article offers a fresh interpretation of the life of Krotoa/Eva, the famous Khoena interpreter of Jan Van Riebeeck, whose gender gave her a unique position in relation to both Dutch and Khoena society. It appears that her own people sent her to work for the Dutch as a young girl, both to serve as a token of goodwill, to gain prestige as the protegee of the household of a powerful leader and to become familiar with Dutch ways. The Dutch received her comfortably as a servant, child minder and companion for Van Riebeeck's young nieces. When Eva learned Dutch expertly, she quickly became their most trusted interpreter. The evidence also hints at an especially close and sensitive, possibly sexual, relationship between her and Van Riebeeck. When military conflicts left Eva identified as a Dutch collaborator, she contacted her sister's husband, chief Oedasoa. Her direct mediation enabled the Dutch to open up a profitable new trading enterprise with Oedasoa, who in turn used Eva as his personal agent within the Dutch community. Her unique position attracted the attention of a bright young employee of the Company, Pieter Van Meerhoff, who became her lover soon after his arrival at the Cape in 1659. Pieter became actively involved in northern expeditions of exploration and prided himself on his sensitivity and capacity to get on well with various Khoena chiefs. Eva continued as an interpreter, intermediary with Oedasoa and the couple had two children together. Eva and Pieter married only after Van Riebeeck left the Cape. Their decision to conform to the norms of Dutch society disappointed Oedasoa who had offered them enough livestock to establish an independent lifestyle but brought both much higher levels of respect from the Dutch, including significant promotions for Pieter. When Pieter was killed in 1666, heading up a trading mission to Mauritius, Eva's life sharply deteriorated. She died in 1674, accused of having become a drunken pest and prostitute. Eva's story exemplifies how an African woman in an early colonial encounter could manipulate a variety of gender roles. Seen as a safe intermediary by both Africans and Europeans, she built herself a unique career and formed a durable liaison with a spirited young man. However, as the nature of contact between the races deteriorated, her role as intermediary diminished in importance. Ultimately, without Pieter, she could not sustain her pivotal place in Dutch society, dying a miserable death. Her life reflects the rapidly changing nature of early colonial contacts.
- Full Text:
- Date Issued: 1998
Evaluation of the proposed FDA pilot-dose response methodology for topical corticosteroid bioeqivalence testing [authors' reply in Letters to the Editor]
- Authors: Smith, Eric W , Walker, Roderick B , Haigh, John M , Kanfer, Isadore
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6423 , http://hdl.handle.net/10962/d1006558
- Description: Reply to: Letter to the Editor by Singh GJ; Fleischer N; Lesko L; Williams R - relating to original article in Pharmaceutical Research (USA), Mar 1997, vol. 14, pp. 303-308.
- Full Text: false
- Date Issued: 1998
Finding the optimum: fluoridation of potable water in South Africa
- Authors: Muller, Wilhelmine J , Heath, R G M , Villet, Martin H
- Date: 1998
- Subjects: Water SA
- Language: English
- Type: Article
- Identifier: vital:6921 , http://hdl.handle.net/10962/d1011904
- Description: Since the South African Department of Health has tabled legislation to make fluoridation of public water supplies mandatory, the issue of whether fluoride is beneficial or harmful has, once again, become controversial in South Africa. We reviewed the literature, the experiences of fluoridation in overseas countries and the latest WHO recommendations, and have found that fluoride is desirable at certain levels, and undesirable above these. The following recommendations are made for optimum fluoride levels in South Africa's potable water: The decision to fluoridate a public water supply must be a community decision taken after public consultation. However, it can only be reached when the public is properly informed about the issue. Optimum levels of fluoride for human health range from 0.4 to 0.7 mg F/l, depending on the maximum mean annual temperature. The maximum level of 0.7 mg F/l should not be exceeded. Accordingly, it is recommended that in areas where natural fluoride concentrations in the drinking water exceed 0.7 mg F/l steps be taken to defluoridate the water. As an interim measure, a scale of temperature-adjusted optimum fluoride levels should be adopted in South Africa, rather than a single level covering the wide-ranging ambient temperatures (and corresponding consumption rates of drinking water) in the country. A sliding scale would mean that the community within a water supply region can determine its own fluoride consumption within the optimum range. Fluoridation should be considered only a short-term measure, until economic conditions are such that all South Africans have access to proper dental health care. The duration of fluoridation of a community water supply, and the level of fluoridation (within the optimum range of fluoride levels) should both be considered community decision. However, defluoridation should be a permanent necessity in those areas where the drinking water exceeds levels of 0.7 mg F/l.
- Full Text:
- Date Issued: 1998
Fluvial conditions during the Holocene as evidenced by alluvial sediments from above Howison's Poort, near Grahamstown, South Africa
- Authors: Lewis, Colin A , Illgner, Peter M
- Date: 1998
- Language: English
- Type: Article
- Identifier: vital:6697 , http://hdl.handle.net/10962/d1006733
- Description: Mapping and analyses of alluvial sediments in the Berg River valley, near Grahamstown, has resulted in the identification of over 5 000 years of environmental stability in the early Holocene, in which flood plain sediments accumulated. Subsequent to 4390±90 BP environmental instability, probably due to climatic fluctuations, resulted in the formation of river terraces. Further research is needed to establish the area! limits of this sequence of Holocene climatic and environmental events.
- Full Text: false
- Date Issued: 1998
In vitro permeation of progesterone from a gel through the shed skin of three different snake species
- Authors: Haigh, John M , Beyssac, E , Chanet, L , Aiache, J M
- Date: 1998
- Language: English
- Type: Article
- Identifier: vital:6366 , http://hdl.handle.net/10962/d1006066
- Description: The in vitro diffusion of progesterone from a gel formulation using the European Pharmacopoeia method for transdermal dosage forms is described. The membranes used were the dorsal and ventral portions of the shed skin of three different species of snake. Considerable differences are apparent between the dorsal and ventral sites and between the different species of snake. The dorsal area shows better permeability for progesterone and the permeability order for the different species is python>cobra>viper. These differences may be due to the thickness of the skin and the hinge:scale ratio. The results indicate that shed snake skin is not a model membrane for human skin.
- Full Text:
- Date Issued: 1998
Morphological and genetic differentiation of Patella granularis (Gastropoda: Patellidae): recognition of two sibling species along the coast of southern Africa
- Authors: Ridgway, Tyronne M , Stewart, Barbara A , Branch, George M , Hodgson, Alan N
- Date: 1998
- Subjects: Patellidae
- Language: English
- Type: Article
- Identifier: vital:6944 , http://hdl.handle.net/10962/d1011971
- Description: Morphological and isozyme variations between 13 populations of the species hitherto named Patella granularis were investigated to see whether differences in shell structure between the west coast versus the south and east coasts of southern Africa are supported by other morphological features or by genetic differences. The shells showed a definite decrease in size from west to east, but this is correlated with productivity and is of no diagnostic use in distinguishing between populations. Discriminant functions analysis based on shell morphometrics failed to separate populations from the three coastal regions. Shells from the northern east coast do, however, have shell nodules with a dark pigmentation, distinctly separating them from those further south and west. No differences in radular or soft part morphology were detected between the populations, but the four northernmost populations on the east coast have a significantly shorter Z looping of the gut than the other populations along the coast. Significant microstructural differences in the sperm were also detected between these two groups of populations. Electrophoretic analysis of 16 enzyme loci failed to detect any significant differences between the west and south coast populations, but revealed a genetic identity (Nei) of 0.528 as well as four diagnostic alleles between the four northernmost populations from the east coast compared with those to the south and west. The two genetically distinct forms occurred sympatrically at one of the study sites on the east coast (Coffee Bay). It was concluded the two groupings were sufficiently different to warrant the recognition of a separate species, which is centred in KwaZulu-Natal on the east coast and extends south to Coffee Bay, from where it is replaced by P. granularis. There is, however, no evidence at all that the west coast populations are in any way separable from the remaining populations of P. granularis on the south coast.
- Full Text:
- Date Issued: 1998
New developments in the methodology available for the assessment of topical corticosteroid-induced skin blanching
- Authors: Haigh, John M , Smith, Eric W , Maibach, Howard I
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6384 , http://hdl.handle.net/10962/d1006305
- Description: Since the publication of the previous edition of this book there have been considerable developments and controversy in the field of topical corticosteroid bioequivalence assessment. There has been considerable discussion in the literature concerning the use of the Minolta chromameter for the measurement of corticosteroid-induced skin blanching, as it is believed this instrument would produce more objective results than the visual grading procedure. These efforts culminated in the release of a guidance document from the Food and Drug Administration (FDA) detailing the procedures to be followed for the determination of topical corticosteroid bioequivalence using the chromameter. Since the promulgation of this document there have been challenges on the validity and scientific merit of the documented procedures, and recently the FDA itself conceded that it may be necessary to redefine some of the protocol evaluations. This chapter attempts to redefine the current standing of the two methods of response assessment.
- Full Text:
- Date Issued: 1998
Pension payouts, periodic marketing and the continuance of urban dependence in rural South Africa
- Authors: Fox, Roddy C , Nel, Etienne L
- Date: 1998
- Language: English
- Type: Article
- Identifier: vital:6681 , http://hdl.handle.net/10962/d1006675
- Description: The former homeland areas of South Africa are characterised by extreme poverty, high levels of urban dependence, a reliance on pensions and low levels of agricultural production. This paper is based on a case-study of the Eastern Cape province and details rural realities, the importance of pensions and the constraints which face current plans to develop and expand the periodic marketing network.
- Full Text: false
- Date Issued: 1998
Regionalism in marine biology: the convergence of ecology, economics and politics in South Africa
- Authors: McQuaid, Christopher D , Payne, A I L
- Date: 1998
- Language: English
- Type: Article
- Identifier: vital:6938 , http://hdl.handle.net/10962/d1011960
- Description: The South African coast includes biogeographic provinces which are quite distinct in their abilities to sustain exploitation and in the types of exploitation they experience. As a result, no single region can act as a model for the management of living resources around the entire coast. Instead, appropriate management must rest on regionally based research. Past research in marine biology focused on the west coast with much less attention being given to the east and south coasts, where non-commercial, subsistence-level fisheries predominate. A partial decentralisation of research focus is essential. This requires commitment from national-level research bodies and some certainty about at least medium-term funding. This paper addresses the convergence of ecology, economics and politics in South Africa and illustrates the direct relevance that fundamental or basic research can have to socioeconomic problems. Recruitment of the resource; Geographical variation in biological processes; State of research policy; Promise of regulations.
- Full Text: false
- Date Issued: 1998
Research cruise of the Scandinavian/South African Antarctic expedition, December 1997 to February 1998
- Authors: Froneman, P William , Pakhomov, E A , Turner, D , Abrahamson, K , Karlsson, B , Godhe, A , Bertilsson, S , Graneli, W , Carlsson, P , Wangberg, S , Wulff, A , Croot, P , Andersson, K , Balarin, Marianne G , Wedborg, M , Persson, T , Rasmus, K , Ozturk, M , David, R
- Date: 1998
- Language: English
- Type: Article
- Identifier: vital:6934 , http://hdl.handle.net/10962/d1011955
- Description: Focuses on the Scandinavian/South African Antarctic expedition conducted between December 4, 1997 to February 6, 1998 which determined the role of Southern Ocean in the global carbon cycle in physical and biological oceanographic studies. Aims of the expedition; Underway sampling conducted; Biological results of the expedition; Conclusions.
- Full Text: false
- Date Issued: 1998
Surface distribution of microphytoplankton of the south-west Indian Ocean along a repeat transect between Cape Town and the Prince Edward Islands
- Authors: Froneman, P William , Pakhomov, Evgeny A , Meaton, V
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6933 , http://hdl.handle.net/10962/d1011953
- Description: Surface chlorophyll-a (chl-a) concentrations, microphytoplankton (>20 μm) species composition and distribution along a repeat transect between Cape Town and the Prince Edward Islands were investigated in early austral autumn (April/May) 1996. Samples were collected at approximately 30 nautical mile intervals for the analysis of size-fractionated chl-a and the identification and enumeration of microphytoplankton species. Peaks in total chl-a (>1 μg 1 [superscript -1]) were recorded at the Subtropical Convergence (STC), at the Sub-Antarctic Front (SAF) and in the waters surrounding the Prince Edward Islands. In addition, a minor peak in chl-a concentration was recorded in the continental shelf waters. At stations where elevated chl-a concentrations were recorded, microphytoplankton generally formed a substantial contribution (-10%) to total chlorophyll. Outside these regions, total chlorophyll concentrations were lower (<0.9 μg 1 [superscript -1]) and almost entirely dominated by nano- and picophytoplankton, which contributed >95% of the total. Microphytoplankton species composition along both transects were dominated by chain-forming species of the genera Chaetoceros (mainly C. neglectum, C. peruvianus and C. constrictus), Nitzschia spp. and Pseudoeunotia doliolus. Cluster and ordination analysis based on species composition identified five distinct microphytoplankton assemblages, which were closely associated with the different water masses in the region between Cape Town and the Prince Edward Islands. The microphytoplankton species composition and biogeographic zones identified during this investigation are in general agreement with similar studies conducted in the south-west Indian Ocean during the austral summer, which suggests that there are little seasonal trends in both the microphytoplankton species composition and biogeographic zonation.
- Full Text:
- Date Issued: 1998
Symplastic solute transport and avocado fruit development : a decline in cytokinin/ABA ratio is related to appearance of the Hass small fruit variant
- Authors: Moore-Gordon, Clive S , Cowan, Keith A , Bertling, Isa , Botha, Christiaan E J , Cross, Robin H M
- Date: 1998
- Language: English
- Type: Article
- Identifier: vital:6525 , http://hdl.handle.net/10962/d1005959
- Description: Studies on the effect of fruit size on endogenous ABA and isopentenyladenine (iP) in developing avocado (Persea americana Mill. cv. Hass) fruit revealed that ABA content was negatively correlated with fruit size whilst the iP/ABA ratio showed a linear relationship with increasing size of fruit harvested 226 d after full bloom. The effect of this change in hormone balance on the relationship between symplastic solute transport and appearance of the small fruit variant was examined following manipulation of the endogenous cytokinin (CK)/ABA ratio. Application of ABA caused seed coat senescence and retarded fruit growth but these effects were absent in fruit treated with equal amounts of ABA plus iP. Thus, the underlying physiological mechanisms associated with ABA-induced retardation of Hass avocado fruit growth appeared to be inextricably linked to a decline in CK content and included: diminution of mesocarp and seed coat plasmodesmatal branching, gating of mesocarp and seed coat plasmodesmata by deposition of electron dense material in the neck region, abolishment of the electrochemical gradient between mesocarp and seed coat parenchyma, and arrest of cell-to-cell chemical communication.
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- Date Issued: 1998
The end of apartheid and the organisation of work in manufacturing plants in South Africa's Eastern Cape Province
- Authors: Smith, M R , Wood, G T
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6319 , http://hdl.handle.net/10962/d1011313
- Description: The election of 1994 radically changed the environment within which management chose its labour control policies. Prior to the change of government in 1994 plant practices were shaped by the fact of substantial protection against foreign competition, widespread illiteracy, and a set of laws and policies that offered few protections for individual workers or organised labour. Since the change in government the political and legal environment has substantially changed. In this paper we report on management practices before and after the political changes in South Africa in a set of plants in a part of the country where many of the current difficulties of the South African economy exist in a fairly extreme form.
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- Date Issued: 1998
The requirements for accurate analysis of pharmaceutical research at South African Universities
- Authors: Haigh, John M , Smith, Eric W
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6367 , http://hdl.handle.net/10962/d1006067
- Description: International Pharmaceutical Abstracts is a valuable database for pharmaceutical research, although the multisiciplinary nature of this field implies that the database should only be the starting point of a search. This database is totally inappropriate for comparing outputs of individual pharmacy teaching institutions.
- Full Text:
- Date Issued: 1998