Oily start towards a medical biotechnology institute.

It is all about bringing scientific discovery in the medical biotechnology field to the bedside of patients who need it, for which an institute is required to transfer the technology from the academic environment into products for the market place to serve the community. The oil refers to a first (early) example of a product from our laboratories for such a purpose. It is a medical device for the fast diagnosis of tuberculosis, which uses the oily substance surrounding the mycobacterial pathogen as indicator of disease. Biotechnology relates to the environment wherein the Department of Biochemistry engages with other departments and networks to create products for the modern market. Medical describes the research focus of the Biochemistry Department and includes veterinary applications. And start alludes to the history of the department since 1956 to explain its current research focus.PDFkm201

Preparation and properties of a crude extract toxic to guinea-pigs from Pachystigma pygmaeum, a plant causing heart failure in ruminants

Pachystigma pygmaeum is a rubiaceous plant which causes heart failure after ingestion by ruminants. Isolation or characterization of a toxic entity has hitherto been unsuccessful. Extraction of the plant material with water or organic solvents gave poor yields of toxicity in guinea-pigs because of some unusual properties of the toxic entity. We present a method whereby liberation of a toxic entity from the plant material was achieved by fermentation with baker's yeast to give a crude extract with sufficient yield of toxicity for use in further isolation work.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.Department of Agriculture.am201

Enrichment of a fraction toxic to guinea-pigs from Pachystigma pygmaeum (Schltr.) Robyns

Pachystigma pygmaeum is one of several species of rubiaceous plants which cause delayed heart failure among ruminants after their ingestion at relatively high doses. Using guinea-pigs for toxicity determinations, we were able to separate and enrich a toxic fraction from a fermentation extract of the plant material by countercurrent distribution. It contained virtually no potassium salts, passed through a 500 dalton selective membrane, exhibited lability under acid conditions and was toxic at 1 g/kg per os, with a delayed response of 3-4 days.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.Department of Agriculture

The development of an ELISA-assay for semi-quantitative detection of dihydrogriesenin, a sesquiterpene lactone from Geigeria

Certain species of Geigeria contain sesquiterpene lactones which cause vomiting disease in sheep. Dihydrogriesenin (DHG), a sesquiterpene lactone from G. aspera, contains an α-methylene function which can spontaneously react with thiol groups on proteins to form a covalent adduct. A specific antiserum against a DHG-protein adduct can be used to determine the fate of DHG in poisoned animals. The preparation of such an antiserum is reported in this paper. DHG was reacted with cysteine and subsequently coupled to serum albumin using the carbodiimide reaction. When rabbits were immunized with one such conjugate (DHG-bovine serum albumin), it was found that the carrier determinants were immunodominant. A DHG-specific anti-serum of sufficient (ELISA) titre could, however, be obtained by alternating serum albumin carriers for DHG in booster immunizations. The ELISA antigen-antibody reaction could be inhibited by prior reaction of the antisera with cysteinyl-DHG in solution.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.lmchunu2014mn201

Monoclonal antibody characterization of South African field isolates of Haemophilus paragallinarum

A total of 27 different isolates of Haemophilus paragallinarum were made from chickens between June 1991 and December 1992. All of these isolates were examined by ELISA, by means of a locally produced panel of three monoclonal antibodies (denoted F1 , V1 and VF3). The isolates were all of the F1 antigenic type. Three of them showed a weak reaction with the F1 monoclonal antibody, while three other isolates reacted strongly with the F1 as well as with the VF3 Mab. A selection of stored Haemophilus isolates, dating from 1984 to 1985, were also examined with the Mabs and found to be of the F1 antigenic type. Fifteen isolates were collected before 1974, i.e. before the use of Haemophilus vaccines in this country. The majority of them were of the F1 antigenic grouping. Some showed a weak reaction with the F1 Mab; others showed a strong reaction with both the F1 and VF3 Mabs; and a few showed no significant reaction with any of the Mabs used. Strains used for the production of infectious coryza vaccine were also examined with the Mabs. Strain 0083 showed a stronger reaction with the V1 Mab than with the F1 Mab, whereas strain 0222 showed no reaction with any of the Mabs. None of the SA field isolates collected since the use of vaccines exhibits the V1 antigenicity, which is the prevalent antigen of strain 0083. Most (80%) of the SA field isolates showed a stronger reaction with the F1 Mab than did strain 0083. Antigenically silent isolates similar to 0222 (Page's serotype B) were isolated before the use of vaccines, but not since.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.South African Cancer Association. Egg Board.mn201

Plasmid-encoded NAD independence in some South African isolates of Haemophilus paragallinarum

Atypical Haemophilus paragallinarum have been isolated from both laying hens and broilers suffering from typical symptoms of infectious coryza in South Africa. Re-inoculation of these bacteria into SPF chickens resulted in similar pathology. The bacteria could be successfully re-isolated from the experimentally infected chickens. Four of the isolates from layers and 3 of those from broilers were found to be closely related to H. paragallinarum serotype A (0083 strain) when tested by the use of a panel of locally developed monoclonal antibodies in the enzyme linked immunosorbent assay (ELISA) . A total of 15 isolates from layers and 19 from broilers were found to be more typical of previously collected South African field isolates of H. paragallinarum. A 3rd group, consisting of 5 isolates from layers and 15 from broilers, showed no reaction with the panel of monoclonal antibodies. All the isolates were regarded as atypical because they no longer required V factor (NAD) for growth, whereas strain 0083 and previously collected field isolates M 85 and SB 86 did require it.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.South African Egg Board. National Cancer Association.mn201

Effects of growth conditions and incubation times on the expression of antigens of Haemophilus paragallinarum which are detected by monoclonal antibodies

Haemophilus paragallinarum causes infectious coryza in poultry, and a panel of monoclonal antibodies (Mabs) were established, which detect surface antigens of this bacterium. It was postulated that these Mabs could be used to detect antigenic differences between strains of H. paragallinarum used in infectious coryza (IC) vaccines, and isolates made from the field , from poultry vaccinated against IC. It has previously been reported that in South Africa there are three different Mab patterns that have been common to H. paragallinarum isolates for the past three decades. The effects of different growth conditions such as duration of incubation, inoculum size, levels of NAD or NaCI in the medium, and the pH of the medium on these Mab patterns were investigated. It was found that many different factors appear to influence the expression of the antigens detected by the panel of Mabs. It was found that at different stages during the growth cycles, the isolates could be classified into different Mab groups. It was also found that alteration of the inoculum size resulted in Mab-pattern switches. Addition of extra NaCI to the medium, in order to slow the growth rate, was found to result in Mab-pattern switches. pH was found to have signifcant effects on the levels of expression of the antigens detected by the Mabs, although these changes did not result in Mab-pattern switches. The effects of pH were also found to be highly strain dependent. The use of NAD, rather than sterile chicken serum, in the medium did not significantly alter the levels of expression of these antigens. Alterations of the growth conditions greatly affected the levels of expression of the antigens detected by the Mabs, and were highly strain dependent. It was not possible to predict the effects of a particular growth condition on a particular strain or isolate of H. paragallinarum.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Changes in the incidences of the different serovars of Haemophilus paragallinarum in South Africa: a possible explanation for vaccination failures

Infectious coryza remains an important disease in the poultry industry despite the long-term and widespread use of vaccines against its causative agent, Haemophilus paragallinarum, in South Africa. In order to detect antigenic changes between populations of H. paragallinarum isolated before the use of vaccines against infectious coryza in this country, and field isolates obtained after the introduction of infectious coryza vaccines, 106 different NAD-dependent isolates (of which 93 were identified as H. paragallinarum) from 63 different farms, and dating from 1972 to March 1995, were identified by means of rabbit antisera against serogroups A, B and C. Serogroup C isolates show weaker cross-protection, requiring the further subdivision of this serogroup into its four different serovars. The percentages of the different serovars obtained in the 1970s, confirmed previously published data on South African isolates. A tendency towards a decrease in the number of serogroup A and serovar C-2 isolates, and an increase in the percentage of serovar C-3 isolates, was noted among isolates of the 1980s. These changes were markedly enhanced in the isolates obtained from 1990 to March 1995. The percentage of serogroup A isolates decreased significantly from 34% in the 1970s to only 5% in the 1990s, and that of serovar C-2 isolates, from 31-18%, while the abundance of serovar C-3 isolates increased significantly from 31% in the 1970s to 73% in the 1990s. Serogroup B remained more or less constant and never reached more than 10% of the population. These results indicate the need for the incorporation of serovar C-3 in a vaccine for use in South Africa, particularly in those areas of the country from which isolates were collected during this study. Some of the NAD-dependent isolates obtained from poultry in South Africa between 1970 and 1995, were biochemically identified as Pasteurella avium and P. volantium. As H. avium has been subdivided and reclassified into the genus Pasteurella, this represents the first report of the identification of P. avium and P. volantium in South Africa.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

Spectrophotometric activity microassay for pure and recombinant cytochrome P450-type nitric oxide reductase

Nitric oxide reductase (NOR) of the P450 oxidoreductase family accepts electrons directly from its cofactor, NADH, to reduce two nitric oxide (NO) molecules to one nitrous oxide molecule and water. The enzyme plays a key role in the removal of radical NO produced during respiratory metabolism, and applications in bioremediation and biocatalysis have been identified. However, a rapid, accurate, and sensitive enzyme assay has not yet been developed for this enzyme family. In this study, we optimized reaction conditions for the development of a spectrophotometric NOR activity microassay using NOC-5 for the provision of NO in solution. We also demonstrate that the assay is suitable for the quantification and characterization of P450-type NOR. The Km and kcat kinetic constants obtained by this assay were comparable to the values determined by gas chromatography, but with improved convenience and cost efficiency, effectively by miniaturization. To our knowledge, this is the first study to present the quantification of NOR activity in a kinetic microassay format.A CSIR parliamentary grant (Pretoria, South Africa)http://www.elsevier.com/locate/yabiohb201

Effects of transformation on the hemagglutinins of Haemophilus paragallinarum

Strain 0083 and two field isolates of H. paragallinarum were previously converted into NAD-independent organisms by the use of crude DNA extractions from naturally occurring NAD-independent H. paragallinarumisolates. Two of these transformed isolates [0083(T) and A745(T)] were used as DNA donors in another transformation experiment in which another field isolate (M85) was used as the DNA recipient. Transformation was confirmed by lack of NAD requirement for growth, by carbohydrate fermentation patterns and by a comparison of the monoclonal antibody patterns of the isolates before and after transformation. Previously, antigenic differences were observed when DNA from an NAD-independent isolate was introduced into strain 0083. Antigenic differences were also seen in the transformed M85 organisms prepared in this work, and these differences were dependent on the antigenic patterns of the DNA donors. It was established by haemagglutination (HA) and haemagglutination inhibition (HI) that the hemagglutinins of 0083, A745/92 and M85 were not affected by transformation. The use of strains transformed to NAD independence for vaccine production appears to be a valid approach, as the transformation appears not to affect the hemagglutinins of the transformed organisms. The major advantage would be the alleviation of the requirement for chicken serum or NAD in the bacterial growth medium used for infectious-coryza-vaccine production.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