Absence of neurotoxicity and hypernociception in rats administered the antiretroviral drug stavudine

Stavudine (d4T), a nucleoside reverse transcriptase inhibitor (NRTI) used to treat infection by the human immunodeficiency virus (HIV), is associated with the development of peripheral neuropathy and pain in HIV-positive patients. The mechanisms of this toxic neuropathy are poorly understood, primarily due to a lack of relevant animal models of the neuropathological process initiated by d4T. I investigated whether daily oral or subcutaneous administration of d4T produces neuropathological changes. Compared to previous descriptions of mechanical hypersensitivity induced by daily oral administration of d4T to rats at a dose of 50 mg.kg-1over a four week period, I found that this dosing regimen did not result in hyperalgesia to blunt and punctuate mechanical stimuli applied to the gastrocnemeus muscle. In agreement with the lack of hyperalgesia, oral administration of d4T at 50 mg.kg-1 over a four week period did not induce significant myelinated nerve fibre loss or morphological changes in the sciatic nerve. I then investigated whether administering 100 mg.kg-1 d4T subcutaneously, and therefore avoiding first-pass metabolism, to rats for four weeks causes hyperalgesia and neuropathological changes in nerve morphology. Daily subcutaneous injections of d4T at 100 mg.kg-1 over a four week period did not induce the development of hyperalgesia to a punctate mechanical stimulus applied to the tail or significant neuropathology. My studies demonstrate that multiple administrations of d4T at 50 mg.kg-1 orally or 100 mg.kg-1 subcutaneously over a four week period do not induce hyperalgesia or nerve fibre pathology in rats. Thus, developing a robust animal model of d4T-induced neuropathy may be challenging in the absence of HIV-infection, such that occurs in infected patients. Key words: HIV, ART, d4T, hypernociceptio

Consumers’ preference and willingness to pay for graded beef in Polokwane municipality, South Africa

Consumers around the world are progressively becoming more concerned and aware about food standards, quality and safety issues. The purpose of this study was to determine consumers’ preference regarding safe and quality beef and willingness to pay (WTP) for graded beef in Polokwane municipality, Limpopo Province, South Africa. The research surveyed 150 consumers using a structured questionnaire to collect data on consumer characteristics and responses to different bid levels for graded beef. Analytical methods were descriptive statistics, Likert scales, contingent valuation method to evaluate respondents’ mean WTP for graded beef and logit model to determine the dependence of WTP on consumers’ socioeconomic characteristics. Results showed that consumers prefer their beef tender, with less fat and bones and labelled with price, grade/class, size or quantity of the product and lastly quality inspection or certification indicator. Over half of the respondents (53%) were aware of grading or classification systems. The results further revealed that most respondents are willing to pay an increase of 16.04% over the current price for beef. This could be an opportunity for investments in beef label industry. Consumer characteristics including age, income, gender and household size significantly influenced WTP for graded beef in Polokwane Municipality. Marketing strategies considered by beef product investors should target young, female and wealthier consumers. Grading with respect to quality attributes would make beef sales at differentiated prices possible. This will eventually enhance sales volume and returns for all stakeholders along the value chain

Consumers' preference and willingness to pay for graded beef in Polokwane municipality, South Africa

Consumers around the world are progressively becoming more concerned and aware about food standards, quality and safety issues. The purpose of this study was to determine consumers� preference regarding safe and quality beef and willingness to pay (WTP) for graded beef in Polokwane municipality. The research surveyed 150 consumers using a structured questionnaire to collect data on consumer characteristics and responses to different bid levels for graded beef. Analytical methods were descriptive statistics, Likert scales, contingent valuation method to evaluate respondents� mean WTP for graded beef and logit model to determine the dependence of WTP on socioeconomic factors. Results showed that consumers prefer their beef tender, with less fat and bones and labelled with price, grade/class, size or quantity of the product and lastly quality inspection or certification indicator. Over half of the respondents (53%) were aware of grading or classification systems. The results further revealed that most respondents are willing to pay an increase of 16.04 % over the current price for beef. This could be an opportunity for investments in beef label industry. Consumer characteristics including age, income, gender and household size significantly influenced WTP for graded beef in Polokwane Municipality. Marketing strategies considered by beef product investors should target young, female and wealthier consumers. Grading with respect to quality attributes would make beef sales at differentiated prices possible. This will eventually enhance sales volume and returns for all stakeholders along the value chain. Keywords: Food safety, Graded beef, Preference, Polokwane, Quality, Willingness to pa

Consumers' preference and willingness to pay for graded beef in Polokwane municipality, South Africa

Consumers around the world are progressively becoming more concerned and aware about food standards, quality and safety issues. The purpose of this study was to determine consumers� preference regarding safe and quality beef and willingness to pay (WTP) for graded beef in Polokwane municipality. The research surveyed 150 consumers using a structured questionnaire to collect data on consumer characteristics and responses to different bid levels for graded beef. Analytical methods were descriptive statistics, Likert scales, contingent valuation method to evaluate respondents� mean WTP for graded beef and logit model to determine the dependence of WTP on socioeconomic factors. Results showed that consumers prefer their beef tender, with less fat and bones and labelled with price, grade/class, size or quantity of the product and lastly quality inspection or certification indicator. Over half of the respondents (53%) were aware of grading or classification systems. The results further revealed that most respondents are willing to pay an increase of 16.04 % over the current price for beef. This could be an opportunity for investments in beef label industry. Consumer characteristics including age, income, gender and household size significantly influenced WTP for graded beef in Polokwane Municipality. Marketing strategies considered by beef product investors should target young, female and wealthier consumers. Grading with respect to quality attributes would make beef sales at differentiated prices possible. This will eventually enhance sales volume and returns for all stakeholders along the value chain. Keywords: Food safety, Graded beef, Preference, Polokwane, Quality, Willingness to pa

Pathogenic variability of the fungus Colletotrichum lindemuthianum on dry bean in South Africa

Dry bean (Phaseolus vulgaris L) anthracnose is an economically important seed-borne fungal disease caused by the fungus Colletotrichum lindemuthianum. The pathogenic variability of C. lindemuthianum was evaluated in a glasshouse study. A total of 32 isolates were collected in three provinces, namely KwaZulu-Natal, Mpumalanga and North-West. The isolates were collected from different fields of dry bean at research stations and also from small-scale farmers’ fields. Inoculum developed from the different isolates was sprayed onto 12 CIAT differential dry bean cultivars that were used to identify pathogen races. The inoculation was carried out during the trifoliate developmental stage of the dry bean seedlings raised in pots 14 days post-sowing. Using the CIAT binomial system, eight pathogenic races of C. lindemuthianum were identified, namely, 3, 6, 7, 81, 83, 89, 263 and 323 out of the 32 isolates evaluated. Only pathogenic races 7, 81, 83 and 89 were found in the more humid locations of the province of KwaZulu-Natal. Races 7, 81 and 89 are internationally recognized and show characteristics reported of races in Brazil. Race 6 was identified in Mpumalanga and North west provinces and this was important as it has been reported in other Southern African countries. The races populations were distinct between locations as they infected both the Andean and the Meso-American bean landraces. The most important dry bean landraces were AB 136, G 2333, Kaboon, TU and PI 207262 as they showed complete resistance from the isolates. The study findings suggests that these six landraces can be successfully used to improve anthracnose resistance, especially G 2333 because of its horizontal resistance that can be used to improve the current cultivars used for the control of anthracnose in South Africa. Additionally, Cornell 49242 was one of the landraces of importance, as it showed glimpses of anthracnose that faded overtime under controlled suitable environmental conditions. Use of these landraces will ensure stability in the long-term control of dry bean anthracnose since the pathogen C. lindemuthianum is highly variable and widely distributed in South Africa