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 The aliquots withdrawn were stored in bottles containing formol-saline for later microscopic examination.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Series drawn from the same cercarial suspension, which is mixed immediately before each series of aliquots is withdrawn.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is used for doses of over 15000 cercariae, an Estimation Series and an Additional Estimation Series of aliquots are withdrawn from every dose of cercariae to be used for infesting an animal.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 × 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 × 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 × 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 × 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

Eksistensieteologie en godsdiensonderrig

Proefskrif--PU vir CHO1. The problem: In order to be able to confront the modern child with a meaningful and intelligible interpretation of Holy Scripture, the teacher in religious education munt have a sound knowledge of contemporary issues regarding Biblical interpretation, as well as of the situation of the modern child. Uncertainty prevails in theology and radicalism and nee-positivism have led some theologians to announce the death of God. Characteristics of the milieu of the modern child are absurdity, chaos, secularism and horizontalism, loneliness, materialism and industrialism tend to depersonalize modern man. Relativism leads to a hyperdynamic and pluriform culture. Prevailing philosophies (existentialism and neo-positivism on one hand and nee-empiricism and nee-realism on the other) determine and dominate contemporary thought. This is the background against which children have to receive religious education nowadays. Contemporary tendencies confront teacher, parent and catechist with problems which demand an answer. 2. The origin of modern existentialist theology: Modern existentialist theology has its origin in the old Gnostics and the "Aufklarung", especially the positivism of Lessing and the anti-metaphysical conclusions of Kant. The search for a concept of reality developed into phenomenology, nee-positivism, neo-realism and secularism. Hegelian dialectics and existentialism with their anti-metaphysical tendencies and anthropocentrism were the cradle of the "new" theology. Contributory factors are the emerging natural and technical sciences, historical criticism, Barthianism, Bible criticism, pietism, nineteenth century modernism, contemporary problems of Biblical interpretation for modern man and the relative neglect by the church of "secular" matters. 3. The nature of ecistentialist theology: The Bible is regarded as mythological writing that needs to be interpreted existentially in order to be comprehensible to modern man. Jesus is conceived of as a human model and not as Saviour. Radicalists plead for the abandonment of religion by the church. For them the church is an altruistic institution for the advancement of human happiness and welfare in this world. Love for one's fellowman is considered to be the sole standard of morality. 4. The implications of existentialist theology for religious education: Recent years have seen the publication of some text-books and educational articles on religious education, which reveal undeniable features of existentialist theology. In Chapter 4 of this thesis a few of these books and articles are discussed as examples of the influence on religious education of the "new" theology. 5. Critical evaluation of existentialist tendencies: in theology and religious education. Modern theology has many valuable contributions to make to religious education, summoning us to responsicle faith in God, demanding a greater interest in man and his world, giving Christ a central position in religion, opening up new perspectives of the human element in Holy Scripture and disclosing the dangers of a purely conventional religious attitude. On the other hand, modern theology contains many negative and dangerous elements. It is humanistic, dualistic and superficial. Atheism is a direct result of the abandonment of religion. Religion disappears in love of one's fellow man and for Christology and Pneumatology the "new" theologians substitute anthropology. The authority of the Bible is denied while the concrete is absolutized and; idolized. If the church agreed to become merely a welfare organisation, it would lose the true message of the Gospel. 6. The correct understanding and interpretation of Holy Scripture: Modern theology compels the teacher to ascertain what the writers of the Bible were saying to the people of their own day. Modern theology also requires the teacher to declare the eternal truths contained in Holy Scripture and to expound its character as the Word of the living God for the present time. To aid the teacher in interpreting the Bible intelligibly to modern children, Chapter 6 of this thesis presents some hermeneutic principles which take into account the socio-historical background as well as the purpose and real meaning of the respective pericopes. 7. Other methodological and didactic guidelines for an intelligible religious education for the present time: Chapter 7 of this thesis presents methodological and didactic guidelines for the teacher in religious education, such as will help him to avoid the adverse and will enable him to utilise the beneficial elements in the new theological tendencies. The author pleads for real Christian emphasis in the teaching of all school subjects, for purposeful religious education, for actuality and existential experience of the Biblical subject matter for education towards responsibility for stimulation of independent thinking, for implementation of meaningful exercises, for accentuation of perceptivity rather than objective knowledge and memory, for involvement of the scholar in the truths he is learning, for development of a proper conception of the unity of Scripture, for understanding of the child in his situation, for cogent proclamation of the risen Christ (also to be seen in the lives of his modern disciples) and for education in compassion for one's suffering fellow man.Doctora