45 research outputs found
Studies on schistosomiasis. 5. Sampling methods for estimating the numbers of cercariae in suspension with special reference to the infestation of experimental animals
Various sampling methods for Schistosoma mattheei cercariae, including sampling from different concentrations, were tested. The most satisfactory method consisted of mixing the cercarial suspension by pouring it to and fro between two cylinders and then sampling it by oral suction on a bulb pipette with a large aperture. The aliquots withdrawn were stored in bottles containing formol-saline for later microscopic examination. This method of sampling was tested extensively. The results showed that the variation between aliquots was larger than that expected for either a binomial or a Poisson distribution, indicating that the cercariae were not randomly distributed in the suspension. Moreover, significant variations occurred between the totals of series of aliquots, possibly indicating uncontrolled factors, e.g. in mixing. From these results, methods of making up doses of carcariae for infesting sheep and cattle were developed: The Sheep Method is used for doses of up to 15 000 cercariae and is therefore applicable to infestation of primates as well as sheep. Several series of aliquots are made up, some of which (one or more series per animal) are used for infesting the animals concerned (Infestation Series), while others are retained for estimating the infestation doses (Estimation and Additional Estimation Series). One Estimation and one Additional Estimation Series suffice for estimating the numbers of cercariae in up to eight Infestation Series drawn from the same cercarial suspension, which is mixed immediately before each series of aliquots is withdrawn. In the Bovine Method, which is used for doses of over 15000 cercariae, an Estimation Series and an Additional Estimation Series of aliquots are withdrawn from every dose of cercariae to be used for infesting an animal. Thus the number of cercariae is estimated separately for each animal. Formulae were compiled for these methods to determine the upper levels (with a specified probability) of the percentage errors in the estimated doses. These formulae were applied to the results and some expected percentage errors in the numbers of cercariae estimated by the two methods, calculated. A result for the probability distribution of aliquot counts under the assumption of randomness is proved for the first time.The articles have been scanned in colour with a HP Scanjet 5590;
300dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format
Evaluation of the efficacy of anthelmintics against parafilariosis in cattle
Parafilariosis was first described in South Africa in 1964, thereafter being discovered at numerous localities in the country. When it became obvious that Parafilaria bovicola, for which no treatment was known, caused considerable economic losses, trials involving a series of compounds were conducted to identify candidate remedies. This paper describes an anthelmintic test for evaluating the efficacy of compounds for registration for field use.
Recovery of Parafilaria worms is impractical for anthelmintic testing, and consequently the lesion sizes of treated and control groups of cattle are compared statistically, using appropriate statistical tests.
The seasonal incidence of mature worm infection in cattle in South Africa is such that trials should commence after June and be completed before the end of January, allowing a lapse of 70 days between treatment and slaughter for resolution of the lesions. The presently available parafilaricidal compounds while of value for treating slaughter stock, when used alone will probably not be effective for control of infection in the field.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
A technique for the recovery of nematodes from ruminants by migration from gastro-intestinal ingesta gelled in agar : large scale application
A gelled-agar technique for worm recovery was adapted to facilitate the recovery of larval and adult nematodes from the total ingesta of large numbers of sheep. The technique was also used to recover nematodes from 4 calves. In one trial involving 120 sheep, 100 % of 2 013 4th stage larvae (L4) and 92,1% of 134 205 adult Haemonchus contortus migrated from the agar preparations. Highly significantly more male than female worms failed to migrate. Using 1 x 1/10 aliquot to estimate the numbers of worms that failed to migrate from the agar, the mean error in the total worm count (worms that migrated plus those that failed to migrate) per sheep was 2,2 %; with an examination of 2 x 1/10 aliquot the error was 1, 7 %. We concluded from this that the gelled-agar method may be of value for quantitative worm recovery, for example, in anthelmintic tests. In a second trial, 98,5 % of 17 056 L4 and adult nematodes of 5 genera migrated from the ingesta of 4 calves and 96,4% of 62 597 L4 and adult nematodes of 9 species from the ingesta of 15 sheep. In general, L4 migrated slightly more efficiently than adult worms. In sheep and, to a lesser extent, in calves, Haemonchus spp. did not migrate as efficiently as the other genera such as Ostertagia, Trichostrongylus, Nematodirus, Oesophagostomum, Marshallagia and Chabertia.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format
Scalable Culturing of Primary Human Glioblastoma Tumor- Initiating Cells with a Cell-Friendly Culture System
Glioblastoma is the most aggressive and deadly brain cancer. There is growing interest to develop drugs that specifically target to glioblastoma tumor-initiating cells (TICs). However, the cost-effective production of large numbers of high quality glioblastoma TICs for drug discovery with current cell culturing technologies remains very challenging. Here, we report a new method that cultures glioblastoma TICs in microscale alginate hydrogel tubes (or AlgTubes). The AlgTubes allowed long-term culturing (~50 days, 10 passages) of glioblastoma TICs with high growth rate (~700-fold expansion/14 days), high cell viability and high volumetric yield (~3.0 Ă— 108 cells/mL) without losing the stem cell properties, all offered large advancements over current culturing methods. This method can be applied for the scalable production of glioblastoma TICs at affordable cost for drug discovery
Scalable Culturing of Primary Human Glioblastoma Tumor- Initiating Cells with a Cell-Friendly Culture System
Glioblastoma is the most aggressive and deadly brain cancer. There is growing interest to develop drugs that specifically target to glioblastoma tumor-initiating cells (TICs). However, the cost-effective production of large numbers of high quality glioblastoma TICs for drug discovery with current cell culturing technologies remains very challenging. Here, we report a new method that cultures glioblastoma TICs in microscale alginate hydrogel tubes (or AlgTubes). The AlgTubes allowed long-term culturing (~50 days, 10 passages) of glioblastoma TICs with high growth rate (~700-fold expansion/14 days), high cell viability and high volumetric yield (~3.0 Ă— 108 cells/mL) without losing the stem cell properties, all offered large advancements over current culturing methods. This method can be applied for the scalable production of glioblastoma TICs at affordable cost for drug discovery
Scalable Culturing of Primary Human Glioblastoma Tumor- Initiating Cells with a Cell-Friendly Culture System
Glioblastoma is the most aggressive and deadly brain cancer. There is growing interest to develop drugs that specifically target to glioblastoma tumor-initiating cells (TICs). However, the cost-effective production of large numbers of high quality glioblastoma TICs for drug discovery with current cell culturing technologies remains very challenging. Here, we report a new method that cultures glioblastoma TICs in microscale alginate hydrogel tubes (or AlgTubes). The AlgTubes allowed long-term culturing (~50 days, 10 passages) of glioblastoma TICs with high growth rate (~700-fold expansion/14 days), high cell viability and high volumetric yield (~3.0 Ă— 108 cells/mL) without losing the stem cell properties, all offered large advancements over current culturing methods. This method can be applied for the scalable production of glioblastoma TICs at affordable cost for drug discovery
Scalable Culturing of Primary Human Glioblastoma Tumor- Initiating Cells with a Cell-Friendly Culture System
Glioblastoma is the most aggressive and deadly brain cancer. There is growing interest to develop drugs that specifically target to glioblastoma tumor-initiating cells (TICs). However, the cost-effective production of large numbers of high quality glioblastoma TICs for drug discovery with current cell culturing technologies remains very challenging. Here, we report a new method that cultures glioblastoma TICs in microscale alginate hydrogel tubes (or AlgTubes). The AlgTubes allowed long-term culturing (~50 days, 10 passages) of glioblastoma TICs with high growth rate (~700-fold expansion/14 days), high cell viability and high volumetric yield (~3.0 Ă— 108 cells/mL) without losing the stem cell properties, all offered large advancements over current culturing methods. This method can be applied for the scalable production of glioblastoma TICs at affordable cost for drug discovery
Anti-Diarrheal Mechanism of the Traditional Remedy Uzara via Reduction of Active Chloride Secretion
BACKGROUND AND PURPOSE: The root extract of the African Uzara plant is used in traditional medicine as anti-diarrheal drug. It is known to act via inhibition of intestinal motility, but malabsorptive or antisecretory mechanisms are unknown yet. EXPERIMENTAL APPROACH: HT-29/B6 cells and human colonic biopsies were studied in Ussing experiments in vitro. Uzara was tested on basal as well as on forskolin- or cholera toxin-induced Cl(-) secretion by measuring short-circuit current (I(SC)) and tracer fluxes of (22)Na(+) and (36)Cl(-). Para- and transcellular resistances were determined by two-path impedance spectroscopy. Enzymatic activity of the Na(+)/K(+)-ATPase and intracellular cAMP levels (ELISA) were measured. KEY RESULTS: In HT-29/B6 cells, Uzara inhibited forskolin- as well as cholera toxin-induced I(SC) within 60 minutes indicating reduced active chloride secretion. Similar results were obtained in human colonic biopsies pre-stimulated with forskolin. In HT-29/B6, the effect of Uzara on the forskolin-induced I(SC) was time- and dose-dependent. Analyses of the cellular mechanisms of this Uzara effect revealed inhibition of the Na(+)/K(+)-ATPase, a decrease in forskolin-induced cAMP production and a decrease in paracellular resistance. Tracer flux experiments indicate that the dominant effect is the inhibition of the Na(+)/K(+)-ATPase. CONCLUSION AND IMPLICATIONS: Uzara exerts anti-diarrheal effects via inhibition of active chloride secretion. This inhibition is mainly due to an inhibition of the Na(+)/K(+)-ATPase and to a lesser extent to a decrease in intracellular cAMP responses and paracellular resistance. The results imply that Uzara is suitable for treating acute secretory diarrhea
Die separatisme en religieuse bewegings onder die Sotho van die RSA
Afrikaans: Die menigvuldige religieuse groeperinge onder die Sotho beskou hulself
as soveel onafhanklike kerke. Alhoewel die separatisme vanuit die
Volkekunde as voorbeeld van akkulturasie bestudeer is, is aandag gegee
aan die verhouding kerk en sekte asook die aanleiding tot skisma en
heresie. Die aantal bewegings sowel as die getal aanhoriges het oar
die afgelope eeu aansienlik gegroei. Volgens die beste gegewens was
daar 4 000 bewegings in 1980 terwyl die RSA-sensus (1980) die aanhoriges
op 29,3% van die totale swart bevolking bereken het.
Tydens ondersoek is opnames in sowel die platteland as stedelike gebiede
gemaak en TI aansienlike reeks leierspersone uit separatistebewegings
ondervra. Ter illustrasie is ses bewegings verder uitvoerig beskrywe.
Daar is bevind dat die wese van die separatisme as 'n afwyking oor TI
hele spektrum van links na regs aangedui kan word. Die meer ortodokse
bewegings word op TI ~r-regse posisie gekry. Hulle is oor die algemeen
behoudend ten opsigte van die kerke waaruit hulle ontstaan het en TI
verlengstuk in leer en liturgie van hierdie kerke. Ver-links plaas ons
dan daardie bewegings wat in 'n hoe mate afwyk van die kerke waaruit
hulle ontstaan het en oak so akkommoderend teenoor die tradisionele
Afrika-religie staan dat manisme en selfs magiese praktyke in die ·1eer=
stellige en liturgiese kenmerke onderskei kon word.
As belangrikste enkele oorsaak vir die ontstaan van nuwe separatiste groepe moet die herhalende stryd om oppergesag tussen bestaande en
jonger leiersfigure aangedui word. Verdere besondere kenmerke wat aangedui kon word, is die besondere rol van die vrou as leiersfiguur en volgeling; die besondere waarde wat aan helingsrites met "geseende
water" geheg word; asook die wyse waarop die leiersfiguur by baie
bewegings die ou funksies van stamhoof en kragdokter so in horn
verenig dat religieuse bewegings soms soos stameenhede inn nuwe
gedaante vertoon.
Die separatisme moet as paging tot aanpassing inn akkulturasie-opset
gesien word. Aan die linkerkant van die spektrum word die christelike
en tradisionele religie tot TI dubbeldorige vennootskap verbind wat
volgelinge TI sosiale geborgenheid bied.English: The manifold religious movements among the Sotho see themselves as so many independent churches. Though separatism was studied from an anthropological point of view as an example of acculturation, the relationship
between church and sect and motivation towards schism and heresy could
not be ignored. The number of movements and their adherents have greatly
increased during the last century. According to the best information
there were at least 4 000 of these movements in the RSA in 1980.
According to the 1980-census the adherents comprised 29,3% of the total
black population.
During the research surveys were conducted in rural as well as urban
areas in both of which intensive interviewing was conducted with leaders
of separatist movements. Six of these movements were studied in depth.
The nature of separatism could be indicated on a broad spectrum lying
from left to right. On the far right one found the more orthodox
movements which retained many qualities of their churches of origin
in faith and liturgical order. On the far left had to be placed those
movements differing profoundly from their churches of origin and which
showed such extensive accommodation of the traditional religion of
Africa, that manistic and magical elements could readily be indicated
in their faith and liturgical order.
The most important reason for the origination of new separatist groups
was the recurrent contest for autonomous power between existing and
younger leaders. Further characteristics were the particular role of
women both as officiants and followers; the excessive value attached
to healing rituals conducted with "blessed water" , as well as the
way in which the leaders of these movements combined the old roles
of tribal chief and power doctor in their persons giving their
movements a similar configuration as the tribal entities of old.
Separatism was basically evaluated as being examples of adaptation
in acculturative context. On the left side of the spectrum the
Christian faith and traditional religion were often combined into
a dual partnership giving its adherents a special feeling of
social security.Thesis (DPhil (Anthropology))--University of Pretoria, 1986.Anthropology and ArchaeologyDPhil (Anthropology)Unrestricte
Die sillabus vir godsdiensonderrig en Bybelkunde aan Transvaalse onderwysersopleidingsinrigtings
Thesis (MEd)--PU vir CHOMaster